CA2264875A1 - Compositions comprising a substantially random interpolymer of at least one alpha-olefin and at least one vinylidene aromatic monomer or hindered aliphatic vinylidene monomer - Google Patents

Abstract

Disclosed are compositions comprising at least one substantially random interpolymer of ethylene and a vinylidene aromatic monomer or a hindered aliphatic vinylidene monomer and optionally at least one C3-C20 .alpha.-olefin monomer, and at least one tackifier. The claimed compositions are useful in adhesives, such as are employed in various applications, such as in packaging and carton sealing, bookbinding, masking tape, clear office tape, labels, decals, bandages, decorative and protective sheets (such as shelf and drawer liners), floor tiles, sanitary napkin/incontinence device placement strips, sun control films, and the joining of gaskets to automobile windows. The claimed compositions further find use in a variety of applications, such as sealants, coatings, molded articles, and multilayered structures.

Description

CA 02264875 1999-02-23W0 98/10017 PCT/US97/15534Compositions Comprising a Substantially Random Interpolymer of at LeastOne Alpha-Olefin and at Least One Vinvlidene Aromatic Monomer orHindered Aliphatic Vinylidene MonomerThe subject invention pertains to olefin-based compositions. Inparticular, the subject invention pertains to compositions comprising at leastone substantially random interpolymer of at least one oz-olefin and a vinylidenearomatic monomer or a hindered aliphatic vinylidene monomer, preferably atleast one substantially random interpolymer of ethylene, optionally at least oneon-olefin and a vinylidene aromatic monomer, in conjunction with at least onetackifier, and optionally at least one extending or modifying composition orprocessing aid.Substantially random interpolymers of at least one ot-olefin and avinylidene aromatic monomer or a hindered aliphatic vinylidene monomer,including materials such as ot-olefin/vinyl aromatic monomer interpolymers,are known in the art and offer a range of material structures and propertieswhich makes them useful for varied applications, such as compatibilizers forblends of polyethylene and polystyrene as described in US 5,460,818.One particular aspect described by D’Anniello et al. (Journal of AppliedPolymer Science, Volume 58, pages 1701-1706 [l995]) is that suchinterpolymers can show good elastic properties and energy dissipationcharacteristics. In another aspect, selected interpolymers can find utility inadhesive systems, as illustrated in United States patent number 5,244,996,issued to Mitsui Petrochemical Industries Ltd.Although of utility in their own right, the industry seeks to improve theapplicability of these substantially random interpolymers. For example, it maybe desirable in certain instances to manipulate the glass transition temperatureof the substantially random interpolymer, and thus allow materials based onsubstantially random interpolymers to find application, for example, in moldedarticles and as sealants and adhesives.The glass transition temperature of a polymer is one of the majorphysical parameters that determines its mechanical properties. Below the glasstransition temperature, polymers are commonly stiff load bearing rigid plastics.Above the glass transition temperature, materials exhibit more rubbery-1-CA 02264875 1999-02-23W0 98l100l7 PCT/US97/15534behavior. When the glass transition temperature is in the range of roomtemperature, the properties observed for the polymer may change depending onthe ambient conditions. It is therefore advantageous to be able to control theglass transition temperature of a polymer to achieve the desired propertyprofile.For instance, in the case of substantially random interpolymers whichhave a glass transition temperature of about -25 to about 25°C, it would bedesirable in certain instances to raise the glass transition temperature. Forinstance, substantially random interpolymers having a glass transitiontemperature at about ambient temperature are susceptible to detrimentalblocking. Further, when the glass transition temperature is about ambienttemperature, the product properties will vary, depending on the actualtemperature, which leads to an undesired product variance. Further, when theglass transition temperature is at ambient temperature, optimized utility incertain applications, such as in pressure sensitive adhesives, is desired.One way to control the glass transition temperature of a copolymer is tochange the type of comonomer and the amount of it present in the copolymer.For instance, this approach is employed for controlling the glass transitiontemperature of acrylic copolymers.An alternative to varying comonomer content is to add to a basematerial another material having a different glass transition temperature.However, it is known that the addition of a low molecular weight brittle diluent,while it may increase the glass transition temperature, will typically lead to adegradation in mechanical properties, such as tensile strength. It was expectedthat the addition of the class of materials commonly decribed as tackifiers tosubstantially random interpolymers, particularly those interpolymers which areelastomeric, would dilute the polymer network and lead to tensile properties,that is, tensile strength at break and elongation at break, which are less than thesubstantially random interpolymer alone.There is a need to provide compositions comprising substantially randominterpolymers of at least one on-olefin and at least one vinylidene aromatic or hinderedaliphatic monomer which have an increased glass transition temperature overunmodified substantially random interpolymers, particularly which have a glasstransition temperature greater than room temperature. There is a need for such acomposition which is attained without a corresponding loss in tensile properties.There is a need to provide improved hot melt adhesive formulations comprising-2-CA 02264875 1999-02-23WO 98110017 PCTIUS97/ 15534substantially random interpolymers of at least one oL—olefin and at least one vinylidenearomatic or hindered aliphatic monomer which accords superior performancecharacteristics to the unmodified polymers, which will further expand the utility ofthis interesting class of materials.Hot melt adhesives generally comprise three components: a polymer, atackifier, and agvax. Each component may comprise a blend of two or morecomponents, that is, the polymer component may comprise a blend of twodifferent polymers. The polymer provides cohesive strength to the adhesivebond. The tackifier provides tack to the adhesive which serves to secure theitems to be bonded while the adhesive sets, and reduces the viscosity of thesystem making the adhesive easier to apply to the substrate. The tackifier maybe further used to control the glass transition temperature of the formulation.The wax shortens the open/close times and reduces the viscosity of the system.Hot melt adhesives may further typically comprise oil as a filler and/or toreduce the viscosity of the system.Hot melt adhesives based on previously used polymers include ethylenevinyl acetate copolymers (EVA), atactic polypropylene (APP), amorphouspolyolefins, low density polyethylene (LDPE), and homogeneous linearethylene/or-olefin copolymers. Prior art hot melt adhesives typically employedlarge levels of tackifier to reduce the viscosity of the system to levels whichenabled its facile application to the substrate, for instance, to viscosities lessthan about 5000 centipoise.Pressure sensitive adhesives are materials which are aggressively andpermanently tacky at room temperature at the time of application, and whichfirmly adhere to a variety of dissimilar surfaces with the application of lightpressure, such as pressing with a finger. Despite their aggressive tackiness,pressure sensitive adhesives may be removed from smooth surfaces withoutleaving significant residue. Pressure sensitive adhesives are widely used ineveryday applications, such as masking tape, clear office tape, labels, decals,bandages, decorative and protective sheets (such as shelf and drawer liners),floor tiles, sanitary napkin/incontinence device placement strips, sun controlfilms, and the joining of gaskets to automobile windows.Historically, pressure sensitive adhesives were based on natural rubberand wood rosins, which were carried by a solvent. Articles bearing suchadhesives were manufactured by applying a solution of the adhesive on asuitable backing, and removing the solvent by a devolatilizing process.-3-CA 02264875 1999-02-23W0 98/10017 PCT/US97/15534However, in response to cost increases in solvents and regulatory restrictionsregarding emissions, water-based adhesives and solid—form hot melt adhesives(HMA’s) have been developed.Historically, adhesives have been based on one of four types ofpolymers: elastomers (such as natural rubber, styrene-isoprene-styrene blockcopolymers, styrene-butadiene-styrene block copolymers, and styrene-butadiene random copolymers); acrylics (such as interpolymers of butylacrylate, 2-ethyl hexyl acrylate, and methyl methacrylate); hydrocarbons (suchas atactic polypropylene, amorphous polypropylene, poly-1-butene, and lowdensity polyethylene); and ethylene vinyl acetate. More recently, hot meltadhesives based on homogeneous linear and substantially linear ethylenepolymers have been disclosed and claimed.Diene-based elastomers may be utilized in solvent-based, water-bom,and hot melt adhesives. However, adhesive systems based on such elastomersare disadvantageous in that the sites of unsaturation in the block copolymerbackbone make the hot melt adhesive susceptible to degradation by the actionof oxygen and ultraviolet light.Acrylic systems, while stable to oxygen and ultraviolet light, are- inferior to diene-based elastomer systems in terms of the balance of tack, peeland creep resistance which is preferred for pressure sensitive adhesiveapplications. Further, such systems are typically available only in the solvent-based and water-bome systems, making them further disadvantageous for thereasons set forth above.Hydrocarbon-based systems were developed at least in part to provideimproved stability to oxygen and ultraviolet light, as compared to diene-basedelastomer systems, as well as the ability to be utilized in hot melt adhesivesystems. Hydrocarbon-based systems which comprise, atactic polypropylene,interpolymers of propylene with higher order oi-olefins, or poly-on-olefins, suchsystems exhibit a poor balance of properties. In particular, poly-1-butene has atendency to slowly crystallize after application to the substrate, leading to aprofound loss of tack. When oil is added to increase tack, the oil tends tomigrate out of the adhesive into the backing layer or the substrate. Atacticpolypropylene and poly-on-olefms suffer from low tensile strength, which leadsto low cohesive strength on peel and to the leaving of a residue on the substratesurface after peeling. Hydrocarbon-based systems are typically not preferreddue to the limited ability of low density polyethylene to accept the formulation-4-CA 02264875 1999-02-23W0 98/10017 PCT/US97/15534ingredients required to produce a hot melt adhesive with suitable mechanicalproperties.Ethylene vinyl acetate based systems are limited in that as higher vinylacetate levels are selected, elastic performance increases, but compatibility withformulation ingredients decreases.Hot melt adhesives based on homogeneous linear ethylene/on-olefincopolymers are disclosed in U.S. 5,530,054.The subject invention pertains to a composition comprising at least onesubstantially random interpolymer of ethylene and a vinylidene aromaticcomonomer or a hindered aliphatic vinylidene comonomer and optionally atleast one third comonomer selected from the group consisting of C3-C20 OL-olefins, and at least one tackifier. The subject invention further pertains to acomposition comprising at least one substantially random interpolymer ofethylene and a vinylidene aromatic comonomer or a hindered aliphaticvinylidene comonomer and optionally at least one third comonomer selectedfrom the group consisting of C3—C20 on-olefins, and at least one tackifier, and atleast one extending or modifying composition or processing aid. The subjectinvention further pertains to such a composition, wherein the extending ormodifying composition is selected from the group consisting of the following:paraffinic waxes, crystalline polyethylene waxes, styrene block copolymers,ethylene vinyl acetate, polymers or interpolymers of styrene and/or alkyl~substituted styrene, such as on-methyl styrene, and homogeneous linear orsubstantially linear interpolymers of ethylene and one or more C3-C20 (X-olefins. The subject invention further pertains to such a composition in theform of an adhesive, a layer of a multilayer food packaging structure, a coating,a sealant, a molded article, or a sound attenuating device.Unless indicated otherwise, the following testing procedures are to beemployed:Density is measured in accordance with ASTM D—792. The samples areannealed at ambient conditions for 24 hours before the measurement is taken.Melt index (12), is measured in accordance with ASTM D—l23 8,condition 190°C/2.16 kg (formally known as "Condition (E)").Molecular weight is determined using gel permeation chromatography(GPC) on a Waters 150°C high temperature chromatographic unit equipped-5-CA 02264875 1999-02-23wo 98/10017 9 PCT/US97/15534with three mixed porosity columns (Polymer Laboratories 103, 104, 105, and106), operating at a system temperature of 140°C. The solvent is 1,2,4-trichlorobenzene, from which 0.3 percent by weight solutions of the samplesare prepared for injection. The flow rate is 1.0 mL/min. and the injection size is100 microliters.The mo\lecular weight determination is deduced by using narrowmolecular weight distribution polystyrene standards (from PolymerLaboratories) in conjunction with their elution volumes. The equivalentpolyethylene molecular weights are determined by using appropriate Mark-Houwink coefficients for polyethylene and polystyrene (as described byWilliams and Word in Journal of Polymer Science, Polymer Letters, Vol. 6,(621) 1968, incorporated herein by reference) to derive the following equation:Mpolyethylene 7‘ 3 * (Mpolystyrene)b-In this equation, a = 0.4316 and b = 1Ø Weight average molecular weight,MW, is calculated in the usual manner according to the following formula: MW= 2 wi* Mi, where wi and Mi are the weight fraction and molecular weight,respectively, of the ith fraction eluting from the GPC column.Melt viscosity is determined in accordance with the following procedureusing a Brookfield Laboratories DVII+ Viscometer in disposable aluminumsample chambers. The spindle used is a SC-31 hot-melt spindle, suitable formeasuring viscosities in the range of from 10 to 100,000 centipoise. A cuttingblade is employed to cut samples into pieces small enough to fit into the 1 inchwide, 5 inches long sample chamber. The sample is placed in the chamber,which is in tum inserted into a Brookfield Thermosel and locked into placewith bent needle-nose pliers. The sample chamber has a notch on the bottomthat fits the bottom of the Brookfield Thermosel to ensure that the chamber isnot allowed to turn when the spindle is inserted and spinning. The sample isheated to 350°F, with additional sample being added until the melted sample isabout 1 inch (2.54 cm) below the top of the sample chamber. The viscometerapparatus is lowered and the spindle submerged into the sample chamber.Lowering is continued until brackets on the viscometer align on the Thermosel.The viscometer is turned on, and set to a shear rate which leads to a torquereading in the range of 30 to 60 percent. Readings are taken every minute forabout 15 minutes, or until the values stabilize, which final reading is recorded.CA 02264875 1999-02-23WO 98/10017 PCT/US97l 15534G’, G”, and peak tan delta are determined as follows. The samples areexamined using melt rheology techniques on a Rheometrics RDA-II DynamicAnalyzer. The Temperature-Step mode is used utilizing the 7.9 mm diameterparallel plates geometry. The sweep is run from approximately -70°C to 250°Cat 5°C per step with 30 seconds equilibration delay at each step. Theoscillatory frequency is l radian/second with an autostrain function of 0.1percent strain initially, increasing in positive 100 percent adjustments wheneverthe torque decreased to 10 grarn-centimeters. The plates are used with an initialgap of 1.5 mm at 160°C. The samples are maintained in a nitrogenenvironment throughout the analyses to minimize oxidative degradation. Aplot of G’ (the dynamic storage modulus of the sample), G” (the dynamic lossmodulus of the sample), tan delta (G’/G”), and peak tan delta (a representationof the glass transition temperature, are plotted.Glass transition temperature (DSC) is determined using differentialscanning calorimetry, with a scan rate of 10°C/minute from -75 to 150°C.Probe tack is determined using a Digital Polyken Probe Tack TesterTMI 80-02-01 (available from Testing Machines, Inc., (New York)), inaccordance with ASTM-D2979-71.The term "interpolymer" is used herein to indicate a copolymer, or aterpolymer, or the like. That is, at least one other comonomer is polymerized withethylene to make the interpolymer.The term "hydrocarbyl" means any aliphatic, cycloaliphatic, aromatic, arylsubstituted aliphatic, aryl substituted cycloaliphatic, aliphatic substituted aromatic, orcycloaliphatic substituted aromatic groups. The aliphatic or cycloaliphatic groups arepreferably saturated. Likewise, the term "hydrocarbyloxy" means a hydrocarbylgroup having an oxygen linkage between it and the carbon atom to which it isattached.The term ”substantially random” in the substantially random interpolymercomprising an on-olefin and a vinylidene aromatic monomer or hindered aliphaticvinylidene monomer as used herein means that the distribution of the monomers of saidinterpolymer can be described by the Bernoulli statistical model or by a first or secondorder Markovian statistical model, as described by J. C. Randall in Polymer SeguenceDetermination. Carbon-13 NMR Method, Academic Press New York, 1977, pp. 71-78.Preferably, the substantially random interpolymer comprising an on-olefin and avinylidene aromatic monomer does not contain more than 15 percent of the total amount-7-CA 02264875 1999-02-23W0 98/ 10017 PCT/U S97/ 15534of vinylidene aromatic monomer in blocks of vinylidene aromatic monomer of morethan 3 units. More preferably, the interpolymer is not characterized by a high degree ofeither isotacticity or syndiotacticity. This means that in the 13C-NMR spectrum of thesubstantially random interpolymer the peak areas corresponding to the main chainmethylene and methine carbons representing either meso diad sequences or racemicdiad sequences should not exceed 75 percent of the total peak area of the main chainmethylene and methine carbons.Any numerical values recited herein include all values from the lower value tothe upper value in increments of one unit provided that there is a separation of at least2 units between any lower value and any higher value. As an example, if it is statedthat the amount of a component or a value of a process variable such as, for example,temperature, pressure and time is, for example, from 1 to 90, preferably from 20 to 80,more preferably from 30 to 70', it is intended that values such as 15 to 85, 22 to 68, 43to 51, 30 to 32 etc. are expressly enumerated in this specification. For values whichare less than one, one unit is considered to be 0.0001, 0.001, 0.01 or 0.1 asappropriate. These are only examples of what is specifically intended and all possiblecombinations of numerical values between the lowest value and the highest valueenumerated are to be considered to be expressly stated in this application in a similarmanner.The interpolymers suitable for use as, or as components in, the compositionsof the invention, include, but are not limited to, interpolymers prepared bypolymerizing one or more on-olefins with one or more vinylidene aromatic monomersand/or one or more hindered aliphatic vinylidene monomers, with interpolymers ofethylene, one or more vinylidene aromatic monomers, and optionally one or more Ot-olefins, being preferred.Suitable oc—o1efins include for example, those containing from 2 to about 20,preferably from 2 to about 12, more preferably from 2 to about 8 carbon atoms.Particularly suitable are ethylene, propylene, butene—l, 4-methyl-1-pentene, hexene-1and octene-1. Other suitable on-olefin monomers include norbornenes.Suitable vinylidene aromatic monomers include, for example, those representedby the following formula:ArI((l3H2)nR1 —- C = C(R2),-3-CA 02264875 1999-02-23W0 98/10017 PCT /US97/15534wherein R’ is selected from the group of radicals consisting of hydrogen and alkylradicals containing from 1 to about 4 carbon atoms, preferably hydrogen or methyl;each R2 is independently selected from the group of radicals consisting of hydrogenand alkyl radicals containing from 1 to about 4 carbon atoms, preferably hydrogen ormethyl; Ar is a phenyl group or a phenyl group substituted with from 1 to 5substituents selected from the group consisting of halo, C ,_,,-alkyl, and CM-haloalkyl;and n has a value from zero to about 6, preferably from zero to about 2, morepreferably zero. Exemplary monovinylidene aromatic monomers include styrene,vinyl toluene, ot-methylstyrene, t-butyl styrene, chlorostyrene, including all isomers ofthese compounds. Particularly suitable such monomers include styrene and loweralkyl- or halogen-substituted derivatives thereof. Preferred monomers includestyrene, ot-methyl styrene, the lower alkyl- or phenyl-ring substituted derivatives ofstyrene, such as ortho-, meta-, and para-methylstyrene, the ring halogenated styrenes,para-vinyl toluene or mixtures thereof. A more preferred monovinylidene aromaticmonomer is styrene.The term "hindered aliphatic or cycloaliphatic vinylidene monomers" meansaddition polymerizable vinylidene monomers corresponding to the following formula:Al1R1 — C = C(R2)2wherein and A’ is a sterically bulky, aliphatic substituent of up to 20 carbons, R‘ isselected from the group of radicals consisting of hydrogen and alkyl radicalscontaining from 1 to about 4 carbon atoms, preferably hydrogen or methyl; each R2 isindependently selected from the group of radicals consisting of hydrogen and alkylradicals containing from 1 to about 4 carbon atoms, preferably hydrogen or methyl; oralternatively R‘ and Altogether form a ring system. By the term “sterically bulky” ismeant that the monomer bearing this substituent is normally incapable of additionpolymerization by standard Ziegler-Natta polymerization catalysts at a ratecomparable with ethylene polymerizations. Preferred hindered aliphatic orcycloaliphatic vinylidene monomers are those in which one of the carbon atomsbearing ethylenic unsaturation is tertiary or quaternary substituted. Examples of suchsubstituents include cyclic aliphatic groups such as cyclohexyl, cyclohexenyl,cyclooctenyl, or ring alkyl or aryl substituted derivatives thereof, tert-butyl, andnorbomyl. Most preferred hindered aliphatic vinylidene compounds are the variousisomeric vinyl- ring substituted derivatives of cyclohexene and substitutedcyclohexenes, and 5—ethylidene-2-norbomene. Especially suitable are 1-, 3-, and 4-vinylcyclohexene.-9-CA 02264875 1999-02-23W0 98ll0017 K PCT/US97/ 15534The interpolymers of one or more oc-olefins and one or more monovinylidenearomatic monomers and/or one or more hindered aliphatic or cycloaliphaticvinylidene monomers employed in the present invention are substantially randompolymers. These interpolymers usually contain from about 1 to about 65 mole percentof at least one vinylidene aromatic monomer and/or hindered aliphatic orcycloaliphatic vinylidene monomer and from about 35 to about 99 mole percent of atleast one aliphaticxot-olefin having from 2 to about 20 carbon atoms. When thesubstantially random interpolymer has from 1 to less than 5 mole percent of the atleast one vinylidene aromatic monomer and/or hindered aliphatic or cycloaliphaticvinylidene monomer, the substantially random interpolymer will impart a crystallinecharacter to the adhesive system. When the substantially random interpolymer hasfrom 5 to less than 25 mole percent of the at least one vinylidene aromatic monomerand/or hindered aliphatic or cycloaliphatic vinylidene monomer, the substantiallyrandom interpolymer will impart an elastomeric character to the adhesive system.When the substantially random interpolymer has from 25 to 50 mole percent of the atleast one vinylidene aromatic monomer and/or hindered aliphatic or cycloaliphaticvinylidene monomer, the substantially random interpolymer will impart an amorphouscharacter to the adhesive system.When the substantially random interpolymer is used as the strength impartingcomponent of an adhesive, the number average molecular weight (Mn) of theseinterpolymers is usually greater than about 1,000, preferably from about 5,000 toabout 1,000,000, more preferably from about 10,000 to about 500,000, and mostpreferably from about 50,000 to about 300,000. As described below, ultra-lowmolecular weight ethylene polymers, one class of which includes ultra-low molecularweight interpolymers of ethylene and at least one vinylidene aromatic monomerand/or hindered aliphatic or cycloaliphatic vinylidene monomer, may suitably beemployed in the practice of this invention, if not as the strength-imparting componentof the formulation, then as tackifiers or modifiers.While preparing the substantially random interpolymers, as will be describedhereinafter, an amount of atactic vinylidene aromatic homopolymer may be formed due Ito homopolymerization of the vinylidene aromatic monomer at elevated temperatures.In general, the higher the polymerization temperature was, the higher is the amount ofhomopolymer formed. The presence of vinylidene aromatic homopolymer is in generalnot detrimental for the purposes of the present invention and may be tolerated. Thevinylidene aromatic homopolymer may be separated from the interpolymer, if desired,by extraction techniques such as selective precipitation from solution with a non solventfor either the interpolymer or the vinylidene aromatic homopolymer. For the purpose of-10-CA 02264875 1999-02-23W0 98/10017 PCT/US97/ 15534the present invention it is preferred that no more than 20 weight percent, preferably lessthan 15 weight percent, more preferably less than 10 weight percent, based on the totalweight of the interpolymers of vinylidene aromatic homopolymer is present.The substantially random interpolymers may be modified by typical grafting,hydrogenation, functionalizing, or other reactions well known to those skilled in the art.The polymers may be readily sulfonated or chlorinated to provide functionalizedderivatives according to established techniques.The substantially random interpolymers are prepared by polymerizing a mixtureof polymerizable monomers in the presence of metallocene or constrained geometrycatalysts.The substantially random interpolymers can be prepared as described in USApplication Serial Number 545,403 filed July 3, 1990 (corresponding to EP-A-0,416,815) by James C. Stevens et al.. Preferred operating conditions for suchpolymerization reactions are pressures from atmospheric up to 3000 atmospheres (300MPa) and temperatures from -3 0°C to 200°C.Examples of suitable catalysts and methods for preparing the substantiallyrandom interpolymers are disclosed in EP-A-416,815; EP-A-514,828; EP-A-520,732;,U.S. Application Serial No. 241,523, filed May 12, 1994; as well as U.S. Patents:5,055,438; 5,057,475; 5,096,867; 5,064,802; 5,132,380; 5,189,192; 5,321,106;5,347,024; 5,350,723; 5,374,696; and 5,399,635.The substantially random or-olefin/vinylidene aromatic interpolymers can alsobe prepared by the methods described by John G. Bradfute et al. (W. R. Grace & Co.)in WO 95/32095; by R. B. Pannell (Exxon Chemical Patents, Inc.) in WO 94/00500;and in Plastics Technology, p. 25 (September 1992).The substantially random on-olefin/vinylidene aromatic interpolymers can alsobe prepared by the methods described in JP 07/278230 employing compounds shownby the general formula1Cp R1/R3 \ M/\\Cp,/ R,where (Cpl and Cpz are cyclopentadienyl groups, indenyl groups, fluorenyl groups, orsubstituents of these, independently of each other; R‘ and R2 are hydrogen atoms,-11-CA 02264875 1999-02-23W0 98/ 10017 A PCT/US97/ 15534halogen atoms, hydrocarbon groups with carbon numbers of 1-12, alkoxyl groups, oraryloxyl groups, independently of each other; M is a group IV metal, preferably Zr orHf, most preferably Zr; and R3 is an alkylene group or silanediyl group used to cross-link Cpl and Cpz).Also suitable are the substantially random interpolymers which possess at leastone on-olefin/vinyl aromatic/vinyl aromatic/on-olefin tetrad. These interpolymerscontain additional signals with intensities greater than three times the peak to peaknoise. These signals appear in the chemical shift range 43.75-44.25 ppm and 38.0-38.5 ppm. Specifically, major peaks are observed at 44.1, 43.9 and 38.2 ppm. Aproton test NMR experiment indicates that the signals in the chemical shift region43.75-44.25 ppm are methine carbons and the signals in the region 38.0-38.5 ppm aremethylene carbons.In order to determine the carbon-13 NMR chemical shifts of theseinterpolymers, the following procedures and conditions are employed. A five to tenweight percent polymer solution is prepared in a mixture consisting of 50 volumepercent l,1,2,2-tetrachloroethane-dz and 50 volume percent 0.10 molar chromiumtris(acetylacetonate) in 1,2,4-trichlorobenzene. NMR spectra are acquired at 130°Cusing an inverse gated decoupling sequence, a 90° pulse width and a pulse delay offive seconds or more. The spectra are referenced to the isolated methylene signal ofthe polymer assigned at 30.000 ppm.It is believed that these new signals are due to sequences involving two head- ’to-tail vinyl aromatic monomer preceded and followed by at least one OL-olefininsertion, for example an ethy1ene/styrene/styrene/ethylene tetradwherein thestyrene monomer insertions of said tetrads occur exclusively in a 1,2 (head to tail)manner. It is understood by one skilled in the art that for such tetrads involving avinyl aromatic monomer other than styrene and an on-olefin other than ethylene thatthe ethylene/vinyl aromatic monomer/vinyl aromatic monomer/ethylene tetrad willgive rise to similar carbon-13 NMR peaks but with slightly different chemical shifts.These interpolymers are prepared by conducting the polymerization attemperatures of from about -3 0°C to about 250°C in the presence of such catalysts asthose represented by the formulaCp/ \(ER2)m MR'2\Cp/-12-CA 02264875 1999-02-23W0 98/ 10017 PCT/US97/15534wherein: each Cp is independently, each occurrence, a substituted cyclopentadienylgroup it-bound to M; E is C or Si; M is a group IV metal, preferably Zr or Hf, mostpreferably Zr; each R is independently, each occurrence, H, hydrocarbyl,silahydrocarbyl, or hydrocarbylsilyl, containing up to about 30 preferably from 1 toabout 20 more preferably from 1 to about 10 carbon or silicon atoms; each R‘ isindependently, each occurrence, H, halo, hydrocarbyl, hyrocarbyloxy,silahydrocarbylyhydrocarbylsilyl containing up to about 30 preferably from 1 to about20 more preferably from 1 to about 10 carbon or silicon atoms or two R’ groupstogether can be a CH0 hydrocarbyl substituted 1,3-butadiene; m is l or 2; andoptionally, but preferably in the presence of an activating cocatalyst. Particularly,suitable substituted cyclopentadienyl groups include those illustrated by the formula:(R)4C7wherein each R is independently, each occurrence, H, hydrocarbyl, silahydrocarbyl, orhydrocarbylsilyl, containing up to about 30 preferably from 1 to about 20 morepreferably from 1 to about 10 carbon or silicon atoms or two R groups together form adivalent derivative of such group. Preferably, R independently each occurrence is(including where appropriate all isomers) hydrogen, methyl, ethyl, propyl, butyl,pentyl, hexyl, benzyl, phenyl or silyl or (where appropriate) two such R groups arelinked together forming a fused ring system such as indenyl, fluorenyl,tetrahydroindenyl, tetrahydrofluorenyl, or octahydrofluorenyl.Particularly preferred catalysts include, for example, racemic-(dimethylsilanediyl(2-methyl-4-phenylindenyl))zirconium dichloride, racemic-(dimethylsilanediyl(2-methyl-4-phenyl—indenyl))zirconium 1,4-diphenyl-1 ,3-butadiene, racemic-(dimethylsilanediyl(2—methyl-4-phenylindenyl))zirconium di-C 1 -4alkyl, racemic-(dimethylsilanediy1(2—methy1-4-phenylindenyl))zirconium di-C 1 -4alkoxide, or any combination thereof. 8Further preparative methods for the substantially random interpolymer havebeen described in the literature. Longo and Grassi (Makromol. Chem., Volume 191,pages 2387 to 2396 [l990]) and D’Anniello et al. (Journal of Applied PolymerScience, Volume 58, pages 1701-1706 [l995]) reported the use of a catalytic systembased on methylalumoxane (MAO) and cyclopentadienyltitanium trichloride(CpTiC13) to prepare an ethylene-styrene copolymer. Xu and Lin (Polymer Preprints,Am.Chem.Soc.,Div. Polym. Chem.) Volume 35, pages 686,687 [l994]) have reported-13-CA 02264875 1999-02-23W0 98/10017 PCT/US97/15534copolymerization using a TiCl4/NdC13/Al(iBu)3 catalyst to give random copolymers ofstyrene and propylene. Lu et al (Journal of Applied Polymer Science, Volume 53,pages 1453 to 1460 [l994]) have described the copolymerization of ethylene andstyrene using a TiCl,,/NdCl3/ MgCl2 /Al(Et)3 catalyst. The manufacture of (X-olefin/vinyl aromatic monomer interpolymers such as propylene/styrene andbutene/styrene are described in United States patent number 5,244,996, issued toMitsui Petrochemical Industries Ltd.The polymerization may be carried out in solution, slurry, or gas phasepolymerization reactions. Further, the polymerization may be carried out as abatchwise or a continuous polymerization process. In a continuous process, ethylene,vinylidene aromatic monomer or hindered aliphatic vinylidene monomer, and solventand the optional propylene or alternate third monomer are continuously supplied tothe reaction zone and polymer product continuously removed therefrom.In general, the substantially random interpolymer may be polymerized atconditions for Ziegler-Natta or Kaminsky-Sinn type polymerization reactions, that is,reactor pressures ranging from atmospheric to 3500 atmospheres (350 MPa). Thereactor temperature will typically be from -30°C - 200°C. Preferably, the reactortemperature will be greater than 80°C, typically from 100°C to 200°C, and preferablyfrom 100°C to 150°C, with temperatures at the higher end of the range, that is,.temperatures greater than 100°C favoring the formation of lower molecular weightpolymers. Polymerizations at temperatures above the autopolymerization temperatureof the respective monomers may result in the formation of some amounts ofhomopolymer polymerization products resulting from free radical polymerization.In the case of a slurry polymerization process, the substantially randominterpolymer may use the catalysts as described above as supported in an inertsupport, such as silica. As a practical limitation, slurry polymerizations take place inliquid diluents in which the polymer product is substantially insoluble. Preferably, thediluent for slurry polymerization is one or more hydrocarbons with less than 5 carbonatoms. If desired, saturated hydrocarbons such as ethane, propane or butane may beused in whole or part as the diluent. Likewise the a-olefin monomer or a mixture ofdifferent a-Olefin monomers may be used in whole or in part as the diluent. Mostpreferably the diluent comprises in at least major part the monomer or monomers tobe polymerized.The glass transition temperature of substantially random interpolymersincreases as the mole percent of the vinylidene aromatic comonomer or hinderedaliphatic vinylidene comonomer increases. This suggests that by controlling thecontent of the vinylidene aromatic comonomer or hindered aliphatic vinylidene-14-CA 02264875 1999-02-23WO 98/10017 PCT/US97/15534comonomer, one can control "the tack of the adhesive system. In particular,substantially random ethylene/styrene interpolymers, comprising from 1 to less than 5mole percent styrene will have a Tg of from approximately -15 to -20°C;substantially random ethylene/styrene interpolymers comprising from 5 to less than25 mole percent styrene will have a Tg of from approximately -15 to 0°C; andsubstantially random ethylene/styrene interpolymers at least 25 mole percent styrenewill have a Tg of approximately 0 to 30°C, with Tg being determined by differentialscanning calorimetry. Accordingly, ultra-low molecular weight interpolymers ofethylene and at least one vinylidene aromatic comonomer or hindered aliphaticvinylidene comonomer, may be used as an optional tackifier component of theadhesive system. Those skilled in the art will recognize that the incorporation ofterrnonomers, such as other on-olefins, will give rise to different glass transitiontemperatures than those set forth above.In addition or as an alternative to adjusting the styrene content of thesubstantially random interpolymer, when a composition having a glass transitiontemperature of at least -10°C is desired, particularly when it is desired that thecomposition maintain elastomeric properties, it will be preferred that suchcomposition comprise at least one substantially random interpolymer and at least onetackifier.As used herein, the term "tackifier" means any of several hydrocarbon‘based compositions useful to raise the glass transition temperature of thesubstantially random polymer by at least 5°C and/or to impart tack to a hot meltadhesive which comprises the substantially random interpolymer. ASTM D-1878-6lT defines tack as "the property of a material which enables it to form abond of measurable strength immediately on contact with another surface."Tackifying resins are obtained by the polymerization of petroleum andterpene feedstreams and from the derivatization of wood, gum, and tall oilrosin. Several classes of tackifiers include wood rosin, tall oil and tall oilderivatives, cyclopentadiene derivatives, such as are described in UnitedKingdom patent application GB 2,032,439A. Other classes of tackifiersinclude aliphatic C5 resins, polyterpene resins, hydrogenated resins, mixedaliphatic-aromatic resins, rosin esters, natural and synthetic terpenes, terpene-phenolics, and hydrogenated rosin esters.Rosin is a sold material that occurs naturally in the oleo rosin of pinetrees and typically is derived from the oleo resinous exudate of the living tree,from aged stumps and from tall oil produced as a by-product of kraft paper-15-CA 02264875 1999-02-23W0 98/10017 PCT/US97l15534manufacture. After it is obtained rosin can be treated by hydrogenation,dehydrogenation, polymerization, esterification, and other post treatmentprocesses. Rosin is typically classed as a gum rosin, a wood rosin, or as a talloil rosin which indicate its source. The materials can be used unmodified, inthe form of esters of polyhydric alcohols, and can be polymerized through theinherent unsaturation of the molecules. These materials are commerciallyavailable and can be blended into the adhesive compositions using standardblending techniques. Representative examples of such rosin derivatives includepentaerythritol esters of tall oil, gum rosin, wood rosin, or mixtures thereof.Exemplary aliphatic resins include those available under the tradedesignations Escorezm, Piccotacm, Mercuresm, Wingtackm, Hi-Rezm,Quintonem, Tackirolm, etc. Exemplary polyterpene resins include thoseavailable under the trade designations Nirezm, Piccolytem, Wingtackm,Zonarezm, etc. Exemplary hydrogenated resins include those available underthe trade designations Escorezm, Arkonm, Clearonm, etc. Exemplary mixedaliphatic-aromatic resins include those available under the trade designationsEscorezm, Regalitem, Hercuresm, ART“, Imprezm, Norsolenem M,Marukarezm, Arkonm M, Quintonem, Wingtackm, etc. One particularlypreferred class of tackifiers includes the styrene/or-methylene stryene tackifiersavailable from Hercules. Other tackifiers may be employed, provided they arecompatible with the homogeneous linear or substantially linear ethylene/oholefin interpolymer and the optional plasticizer.A suitable tackifier may be selected on the basis of the criteria outlinedby Hercules in J. Simons, Adhesives Age, “The HMDA Concept: A NewMethod for Selection of Resins”, November 1996. This reference discusses theimportance of the polarity and molecular weight of the resin in determiningcompatibility with the polymer. For the substantially random interpolymersuseful in the practice of the claimed invention, low molecular weight polarresins are indicated to be preferred.The tackifier(s) will typically be present in the composition of theinvention inuan amount of at least 10, typically at least 20 weight percent. Thetackifier(s) will be present in an amount of no more than 90, preferably no morethan 75, and most preferably no more than 70 weight percent.In the case of substantially random interpolymers of at least one OL-olefin and a monovinylidene aromatic monomer, preferred tackifiers will havesome degree of aromatic character to promote compatibility, particularly in the-16-CA 02264875 1999-02-23W0 98/10017 PCTIUS97/15534case of substantially random interpolymers having a high content of themonovinylidene aromatic monomer. As an initial indicator, compatibletackifiers are those which are also known to be compatible with ethylene/vinylacetate having 28 weight percent vinyl acetate. Particularly suitable classes oftackifiers include Wingtackm 86 and Hercotacm 1149 Eastman H—130, andstyrene/on-methyl styrene tackifiers. Another preferred tackifier is Piccotex 75,a pure monomer hydrocarbon resin having a glass transition temperature of33°C, available from Hercules.It is noted that there is an unexpected benefit associated with raising theglass transition temperature of a substantially random interpolymer by additionof a compatible tackifier, in that when a compatible tackifier is utilized, notonly does the glass transition temperature increase, but the tensile strengthincreases without a corresponding decrease in elongation at break, relative tothe unmodified substantially random interpolymer. Although this effect holdstrue for substantially random interpolymers having both a higher and lowercomonomer content, the effect is most pronounced for substantially randominterpolymers having from 45 - 65 weight percent of the monovinylidenearomatic or hindered aliphatic comonomer, which are the most elastomeric ofthe substantially random interpolymers. This is contrary to what is expected,for typically, when a low molecular weight brittle solid is added to anelastomeric solid, the low molecular weight material dilutes the polymernetwork which leads to tensile strength and elongation at break which are lessthan those of the polymer alone.Improved tensile strength has value in a number of applications, such asadhesives, elastomeric film applications, automotive parts, wire and cablejacketing, durable goods (such as appliances), gaskets, and shoe soles.For instance, in the case of adhesive formulations, it has been found thatwhen the glass transition temperature of the substantially random interpolymeris less than -20°C, the composition exhibits poor peel strength and tack.However, by raising the glass transition temperature to 0°C by addition of atackifier increases the peel strength of the formulation.In the case of improved resistance to blocking, it is desirable to avoidbonding together or blocking of polymer pellets during transportation andstorage. Thus, utilizing the compositions of the invention which comprise asubstantially random interpolymer and a tackifier, such that the glass transitiontemperature is above the temperature during transportation and storage, will-17-CA 02264875 1999-02-23WO 98/10017 PCT/US97/15534increase the stiffiiess of the polymer pellets, and will lead to a resistance todeformation during transportation and storage. In another embodiment, pelletsof a substantially random interpolymer may be coated with a tackifier to createa surface composition which comprises the substantially random interpolymerand tackifier which minimizes blocking.The compositions of the invention which comprise a tackifier will findfurther utility in sound attenuation applications. For instance, to attenuatesound, a material must be able to dissipate high levels of energy over the broadfrequency range of normal sound under ambient conditions. This occurs whenthe glass transition temperature is from about -20 to about 10°C. Compositionsof the invention which exhibit a glass transition temperature in this range, willattenuate sound in a variety of structures, such as automobiles.Processing aids, which are also referred to herein as plasticizers, areoptionally provided to reduce the viscosity of a composition, such as anadhesive, and include the phthalates, such as dioctyl phthalate and diisobutylphthalate, natural oils such as lanolin, and paraffin, naphthenic and aromaticoils obtained from petroleum refining, and liquid resins from rosin or petroleumfeedstocks.Exemplary classes of oils useful as processing aids include whitemineral oil (such as Kaydolm oil (available from Witco), and Shellflexm 371naphthenic oil (available from Shell Oil Company). Another suitable oil isTuflom oil (available from Lyondell).When a processing aid is employed, it will be present in thecomposition of the invention in an amount of at least 5 percent. The processingaid will typically be present in an amount of no more than 60, preferably nomore than 30, and most preferably no more than 20 weight percent.The composition comprising the substantially random interpolymer ofethylene and at least one vinylidene aromatic monomer or hindered aliphaticvinylidene monomer, and optional C3-C20 or-olefin, may be optionallymodified by the inclusion of an extending or modifying composition.Exemplary extending or modifying compositions include paraffinic wax,crystalline polyethylene wax, and/or a homogeneous linear or substantiallylinear ethylene/ot—o1efin interpolymer.-13-CA 02264875 1999-02-23W0 98/ 10017 PCT/US97ll5534Likewise, the composition of the invention may fiirther comprise ahomogeneous linear or substantially linear ethylene/oc-olefin interpolymer as anextending or modifying composition. Modification of the composition with ahomogeneous linear or substantially linear ethylene/on-olefin interpolymer,particularly when such interpolymer is an elastomer, will tend to extend thecomposition when the composition comprises a substantially randominterpolymer which has a high styrene content, and to improve the tack andmodulus of the adhesive when the adhesive comprises a substantially randominterpolymer which has a low styrene content.The homogeneous linear or substantially linear ethylene/on-olefininterpolymer is an ethylene polymer prepared using a single site, single sitemetallocene, or single site constrained geometry catalyst. By the termhomogenous, it is meant that any comonomer is randomly distributed within agiven interpolymer molecule and substantially all of the interpolymermolecules have the same ethylene/comonomer ratio within that interpolymer.The DSC melting peak of homogeneous linear and substantially linear ethylenepolymers will broaden as the density decreases and/or as the number averagemolecular weight decreases. However, unlike heterogeneous polymers, when ahomogeneous polymer has a melting peak greater than 115°C (such as is thecase of polymers having a density greater than 0.940 g/cm3), such polymerstypically do not additionally have a distinct lower temperature melting peak.Homogeneous linear and substantially linear interpolymers useful inthe invention further differ from low density polyethylene prepared in a highpressure process. In one regard, whereas low density polyethylene is anethylene homopolymer having a density of from 0.900 to 0.935 g/cm3, thehomogeneous linear and substantially linear interpolymers usefiil in theinvention require the presence of a comonomer to reduce the density to therange of from 0.900 to 0.935 g/cm3.The homogeneous linear and substantially linear interpolymers usefulin the invention are typically characterized as having a narrow molecularweight distribution (MW/Mn). For the linear and substantially linearinterpolymers, the MW/Mn is typically from 1.5 to 2.5, preferably from 1.8 to2.2.In addition or in the alternative, the homogeneity of the polymer maybe described by the SCBDI (Short Chain Branching Distribution Index) orCDBI (Composition Distribution Breadth Index), which are defined as the-19-CA 02264875 1999-02-23W0 98/10017 C PCT/US97/15534weight percent of the polymer molecules having a conomomer content within50 percent of the median total molar comonomer content. The SCBDI of apolymer is readily calculated from data obtained from techniques known in theart, such as, for example, temperature rising elution fractionation (abbreviatedherein as "TREF"), which is described, for example, in Wild et al., Journal ofPolymer Science, Poly. Phys. Ed., Vol. 20, p. 441 (1982), in U.S. Patent4,798,081 (Hazlitt et al.), or in U.S. Patent 5,089,321 (Chum et al.). TheSCBDI or CDBI for the homogeneous linear and substantially linearinterpolymers useful in the invention is preferably greater than 50 percent, morepreferably greater than 70 percent, with SCBDI's and CDBI of greater than 90percent being easily attained.Substantially linear ethylene interpolymers are homogeneousinterpolymers having long chain branching. Due to the presence of such longchain branching, substantially linear ethylene interpolymers are furthercharacterized as having a melt flow ratio (I10/I2) which may be variedindependently of the polydispersity index, also referred to as the molecularweight distribution MW/Mn. This feature accords substantially linear ethylenepolymers with a high degree of processability despite a narrow molecularweight distribution. When a substantially linear ethylene interpolymer isemployed in the practice of the invention, such interpolymer will becharacterized as having an interpolymer backbone substituted with from 0.1 to3 long chain branches per 1000 carbons.Methods for determining the amount of long chain branching present,both qualitatively and quantitatively, are known in the art. For qualitativemethods for determining the presence of long chain branching, see, forexample, U.S. Patent Nos. 5,272,236 and 5,278,272. As set forth therein, a gasextrusion rheometer (GER) may be used to determine the rheologicalprocessing index (PI), the critical shear rate at the onset of surface melt fracture,and the critical shear stress at the onset of gross melt fracture, which in tumindicate the presence or absence of long chain branching as set forth below.For quantitative methods for determining the presence of long chainbranching, see, for example, U.S. Patent Nos. 5,272,236 and 5,278,272;Randall (Rev. Macromol. Chem. Phys., C29 (2&3), p. 285-297), whichdiscusses the measurement of long chain branching using 13C nuclear magneticresonance spectroscopy, Zimm, G.H. and Stockmayer, W.H., J. Chem. Phys.,17, 1301 (1949); and Rudin, A., Modern Methods of Polymer Characterization,-20-CA 02264875 1999-02-23W0 98/10017 PCT/US97l15534John Wiley & Sons, New York (1991) pp. 103-112, which discuss the use ofgel permeation chromatography coupled with a low angle laser light scatteringdetector (GPC—LALLS) and gel permeation chromatography coupled with adifferential viscometer detector (GPC-DV). Further, A. Willem deGroot and P.Steve Chum, both of The Dow Chemical Company, at the October 4, 1994conference of the Federation of Analytical Chemistry and Sepctroscopy Society(FACSS) in St»..Louis, Missouri, presented data demonstrating that GPC-DV isa useful technique for quantifying the presence of long chain branches insubstantially linear ethylene polymers. In particular, deGroot and Chum foundthat the presence of long chain branches in substantially linear ethylenepolymers correlated well with the level of long chain branches measured usingBCNMKThe homogeneous linear or substantially linear extending polmer will be aninterpolymer of ethylene with at least one C3-C20 on-olefin. Exemplary C3-C20 oc-olefins include propylene, isobutylene, 1-butene, 1-hexene, 4-methyl-l-pentene, l-heptene, and l-octene. Preferred C3-C20 on-olefins include 1-butene, l—hexene, 4-methyl-l—pentene, l-heptene, and 1-octene, more preferably l—hexene and l-octene.The homogeneous linear or substantially linear extending polymer may furtherbe an interpolymer of ethylene, the at least one C3-C20 oL—olef1n, and a non-conjugateddiene having from 6 to 15 carbon atoms. Representative examples of suitable non-conjugated dienes include:(a) Straight chain acyclic dienes such as 1,4-hexadiene; 1,5-heptadiene; and 1,6-octadiene;(b) Branched chain acyclic dienes such as 5-methyl-1,4-hexadiene; 3,7-dimethyl-1,6-octadiene; and 3,7-dimethyl-1,7-octadiene;(c) Single ring alicyclic dienes such as 4-vinylcyclohexene; l-allyl-4-isopropylidene cyclohexane; 3-allylcyclopentene; 4—allylcyclohexene; and l-isopropenyl-4-butenylcyclohexene;(d) Multi-ring alicyclic fused and bridged ring dienes such as dicyclopentadiene;alkenyl, alkylidene, cycloalkenyl, and cycloalkylidene norbornenes, such as 5-methylene-2—norbomene; 5-methylene-6-methyl-2-norborncne; 5-methylene-6,6-dimethyl—2-norbomene; 5-propenyl—2-norbomene; 5-(3-cyc1opentenyl)-2-norbornene; 5-ethylidene—2-norbornene; 5—cyclohexylidene-2-norbomene; etc.The preferred non-conjugated dienes are selected from the group consisting of1,4-hexadiene; dicyclopentadiene; 5—ethylidene-2-norbomene; 5-methylene-2--21-CA 02264875 1999-02-23W0 98/10017 PCT/US97/15534norbomene; 7-methyl-1,6 octadiene; piperylene; and 4-vinylcyclohexene. Onesuitable conjugated diene is piperylene.The ethylene/oi-olefin interpolymer will have a density of from 0.850 to0.965 g/cm3, preferably from 0.850 to 0.900 g/cm3, and most preferably from0.870 to 0.890 g/cm3.The ethylene/0L-olefin interpolymer may be of high or low molecularweight. Suitable number average molecular weights range from 3,000 to over100,000, preferably from 3,000 to 60,000. In certain applications, the use ofethylene/on-olefin interpolymers having a number average molecular weightless than 20,000, preferably less than 12,000, will be preferred.Homogeneously branched linear ethylene/on-olefin interpolymers maybe prepared using polymerization processes (such, as described by Elston inUSP 3,645,992) which provide a homogeneous short chain branchingdistribution. In his polymerization process, Elston uses soluble vanadiumcatalyst systems to make such polymers. However, others such as MitsuiPetrochemical Company and Exxon Chemical Company have used so-calledsingle site catalyst systems to make polymers having a homogeneous linearstructure. Homogeneous linear ethylene/or-olefin interpolymers are currently_ available from Mitsui Petrochemical Company under the tradename "Tafmer"and from Exxon Chemical Company under the tradename "Exact".Substantially linear ethylene/on-olefin interpolymers are available from TheDow Chemical Company as Affinitym polyolefin plastomers.In another embodiment, ultra-low molecular weight ethylene polymersmay be employed as an extending or modifying composition. Ultra-lowmolecular weight ethylene polymers are disclosed and claimed in PCTApplication WO 97/26287.Ultra-low molecular weight polymers employed will be either ethylenehomopolymers or interpolymers of ethylene and a comonomer selected fromthe group consisting of C3—C20 on-olefins, styrene, alkyl-substituted styrene,tetrafluoroethylene, vinylbenzocyclobutane, non-conjugated dienes, andcycloalkenes.The ultra-low molecular weight polymer will have a number averagemolecular weight less than 8200, preferably less than 6000, and morepreferably less than 5000. Such ultra-low molecular weight polymer will-22-CA 02264875 1999-02-23W0 98/10017 PCT /US97/15534typically have a number average molecular weight of at least 800, preferably atleast 1300.Ultra-low molecular weight polymers, in contrast to paraffinic waxesand crystalline ethylene homopolymer or interpolymer waxes, will have aM“/Mn of from 1.5 to 2.5, preferably from 1.8 to 2.2.Ultra-low molecular weight ethylene polymers lead to a low polymerand formulation viscosity, but are characterized by peak crystallizationtemperatures which are greater than the peak crystallization temperatures ofcorresponding higher molecular weight materials of the same density. Inadhesive applications, the increase in peak crystallization temperature translatesto an increased heat resistance, for instance, an improved creep resistance inpressure sensitive adhesives, and improved shear adhesion failure temperature(SAFT) in hot melt adhesives.When the ultra-low molecular weight ethylene polymer is aninterpolymer of ethylene and at least one vinylidene aromatic comonomer orhindered aliphatic vinylidene comonomer, it may be employed as a tackifier (asdescribed above). Further, as the mole percent of ethylene increases, thecrystallinity of the interpolymer will likewise increase. Accordingly, ultra-low-molecular weight interpolymers of ethylene and less than 10 mole percent ofthe least one vinylidene aromatic comonomer or hindered aliphatic vinylidenecomonomer, which interpolymers, such interpolymers may be useful as waxesto control the open and close time of the adhesive system.In another embodiment, a traditional wax may be used as an extendingor modifying composition. Modification of the adhesive with a paraffinic waxor a crystalline polyethylene wax, will tend to improve the high temperatureperformance, such as creep resistance and SAFT, and reduce the open and closetimes of adhesives comprising substantially random interpolymers which havea high styrene content.Exemplary traditional waxes include ethylene homopolymers availablefrom Petrolite, lnc. (Tulsa, OK) as Polywaxm 500, Polywaxm 1500,Polywaxm 1000, and Polywaxm 2000; and paraffinic waxes available from CPHall under the product designations 1230, 1236, 1240, 1245, 1246, 1255, 1260,and 1262.-23-CA 02264875 1999-02-23W0 98/10017 _ PCT/US97/15534Polywaxm 2000 has a molecular weight of approximately 2000, anMW/Mn of approximately 1.0, a density at 16°C of about 0.97 g/cm3, and amelting point of approximately 126°C.CP Hall 1246 paraffinic wax is available from CP Hall (Stow, OH). CPHall 1246 paraffinic wax has a melting point of 143 °F (62°C), a viscosity at210°F (99°C) of 4.2 centipoise, and a specific gravity at 73°F (23 °C) of 0.915.Traditional waxes useful in the adhesives of the invention will typicallyhave a density of at least 0.910 g/cm3. Such waxes will have a density of nomore than 0.970 g/cm3, preferably no more than 0.965 g/cm3.Additives such as antioxidants (such as hindered phenols, for example,Irganox ® 1010, Irganox ® B900, and Irganox ® 1076), phosphites (such asIrgafos ® 168)), ultraviolet stabilizers, cling additives (such aspolyisobutylene), antiblock additives, colorants, pigments, and fillers can alsobe included in the compositions of the present invention, to the extent that theydo not interfere with the enhanced properties discovered by Applicants.The additives are employed in functionally equivalent amounts known to thoseskilled in the art. For example, the amount of antioxidant employed is that amountwhich prevents the polymer or composition from undergoing oxidation at thetemperatures and environment employed during manufacture, storage and ultimate useof the polymers. Such amounts of antioxidants is usually in the range of from 0.05 to ,10, preferably from 0.1 to 5, more preferably from 0.1 to 2 percent by weight basedupon the weight of the composition. When employed, the antioxidant is most typicallypresent in an amount less than 0.5 weight percent, based on the total weight of thecomposition.Similarly, the amounts of any of the other enumerated additives are thefunctionally equivalent amounts such as the amount to render the polymer or polymerblend antiblocking, to produce the desired amount of filler loading to produce thedesired result, to provide the desired color from the colorant or pigment. Suchadditives can typically be employed in the range of from about 0.05 to about 50,preferably from about 0.1 to about 35, more preferably from about 0.2 to about 20percent by weight based upon the weight of the substantially random interpolymer,although filler may be employed in amount up to 90 weight percent, based on theweight of the substantially random interpolymer.-24-CA 02264875 1999-02-23W0 98/ 10017 PCT/US97Il5534The compositions of the invention may be prepared by standard meltblending procedures. In particular, the substantially random interpolymer(s),tackifier(s), and optional processing aid(s) may be melt blended at atemperature suitable to achieve the formation of a homogeneous melt blend,typically at temperatures of from 100 - 200°C, and under an inert gas blanketuntil a homogeneous mix is obtained. Any mixing method producing ahomogeneouseblend without degrading the hot melt components is satisfactory,such as through the use of a heated vessel equipped with a stirrer.Further, the substantially random interpolymer(s), tackif1er(s) andoptional extending or modifying composition(s) may be provided to anextrusion coater for application to the substrate. The compositions may furtherbe prepared in a multi-reactor process, for example producing the substantiallyrandom interpolymer in one reactor and further polymer component (such as anultra-low molecular weight polymer or wax) in a second reactor, with othercomponents optionally being introduced into the second reactor or at a pointdownstream of the second reactor, such as via a sidearm extruder.In one preferred embodiment, the composition of the invention will beprovided in the form of an adhesive which comprises at least one substantiallyrandom interpolymer. Typically, the adhesive will comprise from 5 to 75weight percent of at least one tackifier, more preferably from 10 to 70 weightpercent of at least one tackifier. As set forth above, the tackifier will preferablyhave an aromatic character. In some instances, the tackifier will be an ultra-lowmolecular weight interpolymer of ethylene and at least one vinylidene aromaticcomonomer or hindered aliphatic vinylidene comonomer, which interpolymercomprises at least 25 mole percent of the at least one vinylidene aromaticcomonomer or hindered aliphatic vinylidene comonomer.The adhesive of the invention may further comprise at least onemodifying composition, as described above. When such a modifyingcomposition is employed, it will typically be present in the adhesive system inan amount of from 5 to 75 weight percent. One such modifying composition isa traditional wax or an ultra-low molecular weight ethylene polymer. In someinstances, the ultra-low molecular weight ethylene polymer will be aninterpolymer of ethylene and at least one vinylidene aromatic comonomer orhindered aliphatic vinylidene comonomer, which interpolymer comprises lessthan 10 mole percent of the at least one vinylidene aromatic comonomer orhindered aliphatic vinylidene comonomer.-25-CA 02264875 1999-02-23WO 98/10017 PCT/US97ll5534Moreover, the adhesive of the invention may comprise a plurality ofsubstantially random interpolymer components which differ in the amount ofvinylidene aromatic monomer or hindered aliphatic vinylidene monomer content,which difler in molecular weight, or which differ in both the amount of vinylidenearomatic monomer or hindered aliphatic vinylidene monomer content and inmolecular weight.It will be clear that an adhesive containing a very high content of thesubstantially random interpolymer may be designed. For instance, one suchadhesive may comprise as the strength imparting component of the adhesive,from 5 to 75 weight percent of a substantially random interpolymer of ethyleneand at least one vinylidene aromatic comonomer or hindered aliphaticvinylidene comonomer, which interpolymer has an Mn of greater than about10,000 and comprises from 10 to less than 25 mole percent of the at least onevinylidene aromatic comonomer or hindered aliphatic vinylidene comonomer;as a wax, from 5 to 75 weight percent of a substantially random interpolymer ofethylene and at least one vinylidene aromatic comonomer or hindered aliphaticvinylidene comonomer, which interpolymer has an Mn of less than about 8,200and comprises from 1 to less than 10 mole percent of the at least onevinylidene aromatic comonomer or hindered aliphatic vinylidene comonomer;_and as a tackifier, from 5 to 75 weight percent of a substantially randominterpolymer of ethylene and at least one vinylidene aromatic comonomer orhindered aliphatic vinylidene comonomer, which interpolymer has an Mn ofless than about 8,200 and comprises at least 25 mole percent of the at least onevinylidene aromatic comonomer or hindered aliphatic vinylidene comonomer.As set forth in J. Class and S. Chu, Handbook of Pressure SensitiveAdhesive Technology, Second Edition, D. Satas, e., 1989, pp 158-204, therequirements for pressure sensitive adhesive behavior may be defined bytemperature and rate dependent viscoelastic properties of the materials andformulations.Broadly speaking, to be a suitable pressure sensitive, the formulationsmust have a glass transition temperature of from -20 to 25°C, preferably from-10 to 10°C, as reflected by the tan 8 peak temperature at l radian per second,as determined by dynamic mechanical spectroscopy. Broad glass transitionpeaks are favored, in that when the peak is broad, the adhesive will performover a wider temperature range, thereby increasing its utility. Further,-25-CA 02264875 1999-02-23wo 98/10017 A PCT/US97I15534adhesives having a broad glass transition peak typically be characterized ashaving increased tack and peel strength.According to what has come to be known as the Dahlquist criteria,broadly speaking, to be a suitable pressure sensitive, the formulation must havea plateau shear modulus at 25°C at 1 radian per second which is between1 x 105 and 6 x 106 dynes/cm?-, preferably from 1 X 105 and 3 x 105dynes/cm2, as determined by dynamic mechanical spectroscopy. A materialstiffer than this, that is, a material which has a plateau shear modulus at 25°C of1 x 107 dynes/cm-2, will not exhibit surface tack at room temperature. Amaterial less stiff than this, that is, a material which has a plateau shearmodulus at 25°C of 1 x 104 dynes/cmz, will lack sufficient cohesive strength tobe useful.In particular, preferred pressure sensitive adhesives for use in low peellabels will have a G’ of from 3 x 105 to l x 106 dynes/cm2 (0.3 to 1 MPa) and aglass transition temperature of from -50 to -30°C. Preferred pressure sensitiveadhesives for use in freezer labels will have a G’ of from 8 x 104 to 2 x 105dynes/cm2 (0.08 to 0.2 MPa) and a glass transition temperature of from -45 to -30°C. Preferred pressure sensitive adhesives for use in cold temperature labelswill have a G’ of from 2 x 105 to 1 x 106 dynes/cm-2 (0.2 to 1 MPa) and a glasstransition temperature of from -25 to -10°C. Preferred pressure sensitiveadhesives for use in pressure sensitive adhesive tapes will have a G‘ of from 7 x105 to 5 x 106 dynes/cmz (0.7 to 5 MPa) and a glass transition temperature offrom -10 to 10°C. Preferred pressure sensitive adhesives for use in high peellabels will have a G’ of from 2 x 105 to 6 x 105 dynes/cmz (0.2 to 0.6 MPa)and a glass transition temperature of from 0 to 10°C. Preferred pressuresensitive adhesives for use in disposables will have a G’ of from 4 x 105 to 2 x106 dynes/cm2 (0.4 to 2 MPa) and a glass transition temperature of from 10 to30°C.Glass transition temperature is a function of tackifier content, thepresence and amount of processing aid, and the styrene content and molecularweight of the substantially random interpolymer. Accordingly, to raise the glasstransition temperature of the composition of the invention, one may increasethe amount of or glass transition temperature of the tackifier, decrease theamount of processing aid, or increase the amount of vinylidene aromaticmonomer or hindered aliphatic vinylidene monomer in the substantially randominterpolymer. The plateau shear modulus is a function of the presence and-27-CA 02264875 1999-02-23WO 98/10017 PCT/US97I15534amount of processing aid and the styrene content and molecular weight of thesubstantially random interpolymer. To decrease the G’, one may increase theamount of processing aid in the composition or increase the amount ofvinylidene aromatic monomer or hindered aliphatic vinylidene monomer in thesubstantially random interpolymer.The compositions of the invention will have utility in applications inwhich adhesives, particularly hot melt adhesives are typically employed. Somerepresentative examples include packaging, box and carton sealing,bookbinding, lamination of veneers to a substrate, tapes, and labels. Thecompositions may further be utilized in multilayer food packaging structureswherein at least one layer of the structure is aluminum. The compositions maybe readily extruded onto a variety of substrates, including but not limited tocarpet backing, flooring tiles and sheets, and woven and nonwoven fabric. Thecompositions may similarly be molded into a variety of shapes, including butnot limited to shoe soles, seals, toys, durable goods, wire and cable, andgaskets.The following Examples are provided to illustrate particularembodiments of the claimed invention, rather than to limit the scope of theinvention thereto ._Example One: Preparation of Adhesives Based on Substantially RandomInterpolymers of Ethylene and a Monovinylidene Aromatic ComonomerPolymerization of Substantially Random Interpolymers of Ethylene and aMonovinylidene Aromatic ComonomerPolymer A was prepared in a one gallon (3.8 L) agitated semi-continuousbatch reactor. The reaction mixture consisted of approximately 1100 gramscyclohexane and 818 grams styrene. Prior to addition to the reactor, solvent, styreneand ethylene were purified to remove water and oxygen. The inhibitor in the styrenewas also removed. Temperature in the vessel was controlled to a set-point of 60°C byvarying the coolant flow in the cooling coils of the reactor. The vessel was thenpressure controlled to a set point of 100 psig (4.8 kPa) with ethylene. Hydrogen wasadded in a controlled fashion to control molecular weight. The catalyst components,which comprise a monocyclopentadienyl titanium-containing catalyst, such astitanium: (N-1,1-dimethylethyl)dimethyl(l-(1,2,3,4,5-eta)—2,3,4,5-tetramethyl— 2,4-cyclopentadien-1-yl)si1anaminato))(2-)N)—dimethyl, CAS# 135072-62-7,Tris(pentafluorophenyl)boron, CAS# 001109-15-5, modified methylaluminoxane-23-CA 02264875 1999-02-23W0 98/10017 PCT/US97ll5534Type 3A, CAS# 146905-79-5, were flow controlled, on a mole ratio basis of 1/ 1.5/20respectively , and were combined and added to the vessel. After starting, thepolymerization was allowed to proceed with ethylene supplied to the reactor asrequired to maintain vessel pressure. In this case, approximately 50 grams of ethylenewere loaded in the reactor, ethylene flowed into the reactor at a maximum rate of 5.6grams/minute, and the total amount of ethylene added was 87 grams. The 11111continued for 30 minutes. At the end of the run, the catalyst flow was stopped,ethylene was removed from the reactor, about 1000 ppm of Irganoxm 1010antioxidant on a polymer basis was then added to the solution and the polymer wasisolated from the solution. The resulting polymers may be isolated from solution byeither stripping by use of a devolatilizing extruder.Preparation of Adhesive FormulationsThe indicated substantially random interpolymer, tackifier, plasticizer,styrene block copolymer, and antioxidant were simultaneously added in theindicated amounts to a Haake Rheocord 40 mixer using a 200 gram mixingbowl maintained at about 130°C at 95 revolutions per minute. The ingredientswere mixed for about 5 minutes, until they became molten.Escorezm 5300 petroleum hydrocarbon resin is a tackifier availablefrom Exxon Chemical Company (Houston, TX).Irganoxm B900 hindered phenolic antioxidant is available from Ciba-Geigy.Primoil 355 is a mineral oil.Example lwas tested for initial viscosity and viscosity after three days,using a Brookfield viscometer at 350°F (177°C), probe tack, modulus (G'), andpeak tan delta. The formulations and the measured properties are set forth inTable One. Note that in the case of modulus and peak tan delta, the reportedvalues were extracted from a computer-generated plot of the results.-29-CA 02264875 1999-02-23wo 98/10017 A PCTIUS97/15534TABLE ONEExample 1Polymer A 100/45.2Escorezm 5300 Tackifier 100/45.2Primoil 355 20/9.0Irganoxm B900 Antioxidant 1/0.5Probe tack 94G‘ at 0°C (dynes/cmz (MPa)) 1.58 x 108 (158)G‘ at 25°C (dynes/cmz (MPa)) 7.94 x 105 (0.794)G' at 50°C (dynes/cm?‘ (MPa)) 1.58 x 105 (0.158)G’ at 75°C (dynes/cmz (MPa)) 2.51 x 104 (0.025l)Temp. at which G‘ = 104 dynes/cmz (10 kPa) (°C) 89Temp. at which G‘ = 105 dynes/cmz (100 kPa)(°C) 57Peak tan delta (°C) 4As illustrated in Table One, the adhesive of Example 1 meets theDahlquist criteria, indicating its suitability as a traditional pressure sensitiveadhesive. The adhesive of Example 1 is further preferred in that it has a glasstransition temperature in the range of -45 to 30°C. The data regarding Example1, taken in conjunction with the Dahlquist criteria, suggest that the adhesive ofExample 1 may be suitably employed as a high peel label and/or as a pressuresensitive adhesive tape.Examples 2-8 and Comparative Examples A and B: Hot Melt Adhesives forBonding Aluminum ‘Preparation of Ethylene Styrene Integpolymers B and CPolymer is prepared in a 400 gallon (1500 L) agitated semi-continuous batchreactor, utilizing the process conditions set forth in the following Table Two. Thereaction mixture consisted of approximately 250 gallons (950 L) of a solventcomprising a mixture of cyclohexane (85 weight percent) and isopentane (15 weightpercent), and styrene. Prior to addition, solvent, styrene and ethylene are purified toremove water and oxygen. The inhibitor in the styrene is also removed. Inerts areremoved by purging the vessel with ethylene. The vessel is then pressure controlledto a set point with ethylene. Hydrogen is added to control molecular weight.Temperature in the vessel is controlled to set-point by varying the jacket watertemperature on the vessel. Prior to polymerization, the vessel is heated to the desired-30-CA 02264875 1999-02-23W0 98ll0017 PCT/US97/ 15534run temperature and the catalyst components : Titanium: (N-1,1-dimethylethyl)dimethyl(1-(1 ,2,3,4,5-eta)-2,3,4,5-tetramethyl- 2,4-cyc1opentadien—1 -yl)silana.minato))(2-)N)-dimethyl, CAS# 135072-62-7, Tris(pentafluorophenyl)boron,CAS# 001109-15-5, Modified methylaluminoxane Type 3A, CAS# 146905-79-5, areflow controlled, on a mole ratio basis of 1/3/5 respectively , combined and added tothe vessel. After starting, the polymerization is allowed to proceed with ethylenesupplied to the reactor as required to maintain vessel pressure. In some cases,hydrogen is added to the headspace of the reactor to maintain a mole ratio with respectto the ethylene concentration. At the end of the run, the catalyst flow is stopped,ethylene is removed from the reactor, about 1000 ppm of Irganox* 1010 antioxidant isthen added to the solution and the polymer is isolated from the solution. Theresulting polymers are isolated from solution by either stripping by use of adevolatilizing extruder.Table TwoSample Solvent Styrene Pressure Temp Total Run PolymerNumber loaded loaded . H2 Time inAdded Solutionlbs kg lbs kg Psig kP °C Grams Hrs. Weighta Percent(B) 839 381 661 300 105 72 60 53.1 4.8 11.64(C) 1196 542 225 102 70 48 60 7.5 6.1 7.23Sample Melt Index Total Weight Talc Level IsolationNumber (12 at 190°C) PercentStyrene (Weight Methodin Polymer* Percent)(B) 2.6 45.5 0 Extruder(C) 0.03 29.8 0 Extruder*Tota1 weight percent styrene measured via Fourier Transform Infrared (FTIR)techniqueThe interpolymer and vinyl aromatic polymer characteristics are given inTable Three. The unblended polymers provide the comparative examples of thisinvention.Test parts and characterization data for the interpolymers were generatedaccording to the following procedures:-31-CA 02264875 1999-02-23W0 98/10017 PCT/US97/15534Plaques are compression molded as follows. Samples are melted at 190°C for3 minutes and compression molded at 190°C under 20,000 lb of pressure for another 2minutes. Subsequently, the molten materials are quenched in a press equilibrated atroom temperature.Differential scanning calorimetry (DSC) determinations are made as follows.A DuPont DSC—2920 is used to measure the thermal transition temperatures and heatof transition for the interpolymers. In order to eliminate previous thermal history,samples are first heated to 200°C. Heating and cooling curves are recorded at10°C/min. Melting (from second heat) and crystallization temperatures are recordedfrom the peak temperatures of the endotherm and exotherm, respectively.Melt shear rheology determinations are made as follows. Oscillatory shearrheology measurements are performed with a Rheometrics RMS-800 rheometerRheological properties are monitored at an isothermal set temperature of 190°C in afrequency sweep mode. In tabulated data, 11 is the viscosity and 'r|(l00/0.1) is theviscosity ratio of values recorded at 100/0.1 rad/sec frequencies.Shore A hardness is measured at 23°C following ASTM-D240.F lexural modulus is evaluated according to ASTM-D790.Tensile properties of the compression molded samples are measured using anInstron 1145 tensile machine equipped with an extensiometer. ASTM-D638 samplesare tested at a strain rate of 5 min". The average of four tensile measurements is given.The yield stress and yield strain are recorded at the inflection point in the stress/straincurve. The Energy at break is the area under the stress/strain curve.Tensile stress relaxation is determined as follows. Uniaxial tensile stressrelaxation is evaluated using an Instron 1145 tensile machine. Compression moldedfilm (approximately 20 mil, 0.0508 cm., thick) with a 1" (2.54 cm) gauge length isdeformed to a strain level of 50 percent at a strain rate of 20 min". The force requiredto maintain 50 percent elongation is monitored for 10 minutes. The magnitude of thestress relaxation is defined as (fi-ff/fi) where fi is the initial force and ff is the finalforce.Therrnomechanical analysis (TMA) data are generated using a Perkin ElmerTMA 7 series instrument. Probe penetration to 1 mm is measured on 2 mm thickcompression molded parts using a heating rate of 5°C/min and a load of 1 Newton.-32-CA 02264875 1999-02-23W0 98/10017Table ThreePCT/U S97/ 15534Interpolymer and vinylidene aromatic polymer blend components(C) (D)Compositionweight percent atactic 10.3 1Polystyrene in Interpolymer‘weight percent Styrene‘ 43 .4 29.3weight percent Ethylene 56.6 70.7mole percent Styrene 17 .1 10mole percent Ethylene 82.9 90Molecular WeightMelt flow rate, I, (g/10 min) 2.62 0.03M,,x10" 66.8 118.1MVJMH 1.89 2.04Physical PropertiesDensity. g/cc 0.9626 - 0.943Tm, °C 49.6 71.3Percent Crystallinity 4.8 14.7Tc, °C 22.1 58.1Tg(DSC) approximately -12 -17.2Mechanical PropertiesShore A 75 88Tensile Modulus, MPa 6.5 20Flexural Modulus, MPa 68.8 62.1Yield Stress, MPa 1.3 2.4Percent Strain at Break 475.3 377.5Stress at Break, MPa 22.6 34.3Energy at Break, N°m 102.2 145.5Percent Stress Relaxation (50 38 30.2percent/10min)Melt Rheologyr1x10'5(0.1 rad/sec), Poise 1.05 16.6'q(100/0.1) 0.15 0.16‘Tan 5 (0.1 rad/sec) 4.2 2.371 Measured by NMR technique.2 Ratio ofn(l.6)/ n(0.1).-33-CA 02264875 1999-02-23W0 98/ 10017 V PCTIUS97/15534The formulations described in Table Four were prepared in a 60 mLBrabender mixer using roller blades. The bowl was heated to 130°C prior topolymer introduction. The blade speed was 30 revolutions/minute. After thepolymer was fused (approximately 5 minutes) the other ingredients were addedin small portions over a period of 10 to 30 minutes. The rate of additiondepended on the rate at which the mixing incorporated the material into themixture. Where there was a large mismatch in the melt viscosity of thematerials being mixed, higher temperatures and longer mixing times were used.After the addition was complete, mixing was continued for 10 minutes or untilthe sample was visually homogeneous.Adhesion samples were prepared from 3.17 x 15 cm strips of aluminumfoil 0.002 cm thick. The surface was wiped with methyl ethyl ketone prior tobonding to remove any surface contamination. Samples were prepared in atetrahedron press with the platens set at 177°C. The samples were compressionmolded between layers of silicone release paper using the following cycle: (1)equilibrate 30 seconds at 177°C under contact pressure, (2) ramp ram pressureto 11.2 kg/cmz, (3) maintain pressure for 2 minutes and release. The pressurecorresponds to approximately 1.4 kg/cm’ on the samples.Samples were tested in the T-peel geometry (ASTM-1876) using anInstron tensile tester. Crosshead speed was 2.5 cm/min. Sample compositionand performance are set forth in Table Four.-34-CA 02264875 1999-02-23Wingtack is a trademark of Goodyear. Hercotac is a trademark ofHercules. Eastotac is a trademark of Eastman Chemical. Polywax is atrademark of Petrolite.W0 98/10017 PCT/US97/15534Table FourPolymer type and Tackifier Wax (weight Peel strengthamount (weight percent) (weight percent) percent) (g/cm)Example 2 Polymer B--100 98Example 3 Polymer B- 50 Wingtack TM 153286 -- 50Example 4 Polymer B- 50 Hercotacm 6721149 -- 50Example 5 Polymer B-- 50 Eastotac TM 870H130 —- 50Example 6 Polymer C-- 50 Wingtack TM 118086 —— 50Example 7 Polymer C-- 50 Wingtack 7“ 12795 -- 50Example 8 Polymer B-- 40 Wingtack TM Polywax” 32986 —- 40 1000 -— 20Comparative Polymer D-- 33 Wingtack TM Polywax” 77Example A 95 -- 33 1000 -- 33Comparative Polymer E-— 50 Wingtack TM Polywax“ 257EX3mP1° B 95 -- 50 1000 -- 33A comparison of Examples 3 to 6 of Table Four illustrates the fact thatformulations including an appropriate tackifier exhibit peel strengths which areimproved over that of the uncompounded ethylene/ styrene interpolymer.Formulation 7 illustrates the negative effect of an incompatible or only partiallycompatible tackifier. As illustrated by Example 8, the addition of wax to thehigh peel strength adhesive of Example 3 decreases the peel strength ascompared to that of the adhesive of Example 3, but results in a peel strengthwhich is superior to that of the comparative ethylene/octene interpolymer basedformulations of Comparative Examples A and B.-35-CA 02264875 1999-02-23W0 98/ 10017 PCT/US97/15534Examples 9 - 21 and Comparative Examples C, D, and E:The formulations utilized in the following examples were prepared inthe manner set forth above. In the case of Examples 9 - 12, the polymerutilized was Polymer D, a substantially random ethylene/styrene interpolymerhaving 42 weight percent styrene and a melt index (12) of 1 g/10 min. In thecase of Examples 13 - 16, the polymer utilized was Polymer E, a substantiallyrandom ethylene/styrene interpolymer having 57 weight percent styrene. In thecase of Examples 17 - 21, the polymer utilized was Polymer F, a substantiallyrandom ethylene/styrene interpolymer having 65 weight percent styrene. Thetackifier utilized was Piccotex 75, which is a pure monomer resin having aglass transition temperature, as determined by DSC, of 3 1°C, and which isavailable from Hercules. The extending or modifying composition utilized wasTuflo 6056, which is a mineral oil available from Lyondell Petrochemical.The resultant formulations were evaluated for glass transitiontemperature, tensile at break, elongation at break, bond strength, G’, 100percent modulus, 200 percent modulus, and toughness.In the case of tensile determinations, samples were molded at 115°C for 5minutes at 10 tons ram pressure. Samples which were 1 inch (2.54 cm) by 0.125inches (0.318 cm) are utilized. The Instron tensiometer was set at a crosshead speedof 50 cm/min. Modulus was taken as the slope of the stress—strain curve at 100 and200 percent extension (as measured by crosshead displacement). Toughness was thearea under the stress—strain curve.In the case of G’ determinations, a Rheometrics RDSII Solids Analyzer wasused with 8 mm diameter parallel plates, operated in the shear mode. The test ratewas 1 radian/second. The temperature was stepped from 5 to 10°C, and wasallowed to equilibrate for 2 minutes before data collection.The formulations and the resultant properties are set forth in thefollowing Table Five.-36-CA 02264875 1999-02-23PCT/US97/ 15534W0 98/10017 ߢovv A¢mQov Aeomv ANQQV flaav Ao~_V Amc_zcmsv3.: 2:3 8% as w? Sm SE of x om.» 3 c 8 S m 3:30 55.8 3%: 2:3 33.8 so: Au: X as:3 2:3 33 on 3. an: E 2: x SN N2. 02 92 E. m 2Rafi mod 3.: 5.0 62 x _N. : 9.8.3 o .5Q2 92 $2 an Gm om: 9% >2 x _m._ S- o o 9: 50 m 9:83.3; 88.8 3.5 2.9 cm: 3.3 E: x fitN3 mmmod $2; 3 we $2 $2 $1 is :2. o cm 2. Q 285 28.8 6.5 $0.: ca: 3% E: x 8.83: «mod 5:: am 8; 32 $3 9: x moo NE- o 3 mm Q I58 38.8 Sat 39: find sad 62 x 8.:3.x 28¢ 28. 2% mm; 02. owmm K: x 3; 3- o 8 S. Q 23.3 95.8 :23 :08 $9 23.3 $2 2 8.3m? 85... 28 VS. 33 So. 93 mo. x Nod EN. 3. 02. S. Q o3.5 ad as 8.3 62 x 3.. : :._8:._ o EQ2 Q2 82. Gm mom om. as: no. x of mm- o o 2: N3 2 .950Acca«.32. 85 Séé 63.53: mafia: $&EZm& €56 53 2:853 E3 Gab Eafiuaeuh 0:023 ccuoba c=8na£m=2.m mmu5_u_£ Rwmvé E3 m2=uoE m=_=coE x35 8 £9.05 A~Eo\mo:.mE :oEm:a:. .3 Eu 3; .3 oaemm uicazmuwEo>< mczaou mmucnwsob .523. oom 28.3 2: :o:mw:o_m u=m:u._. ,0 330 mcfimouoi .ucEu...._. .u:_>._o._ SE30;< 2;» 033-37- CA 02264875 1999-02-23PCT/U S97/ 15534WO 9811001785: £33 2&3 $93 38.8 Quad #2 x :3:.m 28¢ 33 man oi Nam 83 9: x _G 3 c om S u 8Q. 3 9.8.8 3.3 God 8.3 $2 x $9Rd 23. at am 5.: 3... So 83 2: x one N2 o 2 2 U. 2Soc 698 3.5 as 88 5 3 E: x 3:£6 28¢ 22. 2.: ma mom RS oi x 3.. 3: o S S m M:Avvmv A~mo¢v Avwuv Amnov Avwdv Anowv Amo_xoo;vCk 38.0 «QM W2. «.3 E2 M2? co. 2 8.. _.o we 0? 8 u E9.5 3.3 :6 5.: 62 x 3.: c=8§_ m E92 92 $3 MS. Sm :3 >5. mm: x of am. o o 2: we ,._ .aEoUAwemv Awmodv Aeovv A»m;v Avgv Aa.m_V Amo_x mewvas no.9 38 com :N 2.2 min me x 3m No- c cm 2 m E6.3 38.3 cod 9.: 3.3 we x ooé8.2 ES :38 38 :.~ SN to 88 E: x 8;. on o 3 2 m 2EQE 8.3 8&3: 6;E\m£V mucous 23:5 V3 Q.=>s 63 E82 V :3 Ann: P_ESoQEu:_. C523 3588 3:85;fiwcubm mmo5_o_£ 25$: 63 m=_=noE 3:608 V285 E fiwcubm A~Eo\8:>3 co:_m:EH 25 Ba .3 :3 oacam oazaxmomSo>< muzaou §_=_w=£ Eoeum can Enema 2: :o:mm=o_m o=m:u._. ,0 $20 wimmouoi §.:V_um.~ Efihom SE33m u>E 29¢...-33-CA 02264875 1999-02-23W0 98l100l7 PCT /US97ll5534Table Five shows that the addition of tackifier to a substantially randomethylene/styrene interpolymer increases the tensile toughness of the interpolymer.This increase in toughness (the result of the increased strain-hardening of theformulation) contributes to an increase in the peel strength of a bonded aluminumspecimen. The aluminum-aluminum bonds are made at 177°C for 120 secondsunder 8 pounds/square inch (0.055 Mpa) pressure. As illustrated by Table Six, theaddition of tackifier to a substantially random ethylene/styrene interpolymer has theability to increase the toughness of a substantially random ethylene/styreneinterpolymer which has less than 5 percent crystallinity by DSC, that is, which ispredominantly amorphous in character.Examples 2] - 23 and Comparative Examples F and G: PSA TapesSamples of pressure sensitive adhesive tapes were prepared by coatingfrom the melt onto a 0.051 mm thick polyester backing, and were covered withsilicone release paper for storage and transportation. The coater was acommercial unit available from Chemsultants International. The adhesivelayers were in the range of 0.09 to 0.115 mm thick. Tests were performed inaccordance with the Pressure Sensitive Tape Council (PSTC) standards. A 180°peel test on stainless steel was done at 30 cm/min, at both 5 minute and 24 hourdwell times. Shear tests (Holding Power) were performed at room temperaturewith a 1000 gram load and an overlay of 12.7 x 25.4 mm on mirror polishedstainless steel.In the case of Comparative Example F, the polymer was Vector 4113styrene/isoprene/styrene block copolymer, available from Dexco Company. Inthe case of Comparative Example G, the polymer was Vector 4114styrene/isoprene/styrene block copolymer, available from Dexco Company. Inthe case of Examples 21 — 23, the polymer was the substantially randominterpolymer of Polymer E.The formulations employed and the resultant adhesive properties are setforth in the following Tables Six and Seven:-39-CA02264875 1999-02-23W0 98/10017 PCT/US97/15534Table SixComp. Ex. F Comp. Ex. G 21 22 23Vector 4113 41.7 0 0 0 0Vector 4114 O 35.7 0 O 0Polymer E 0 0 48.75 57.6 42.5Wingtack 95 52.1 50.0 0 0 0Piccotex 75 0 0 38.75 30.0 32.5Tuflo 6056 6.3 14.3 12.5 12.5 25.0Table SevenComp. Comp. 21 22 23Thickness 4.65 4.25 4.7 4.2 3.7(mils (cm)) (0.12) (0.11) (0.12) (0.11) (0.09)Peel (lbs/in 12.69 5.97 1.85 0.48 0.17(N/25.4 mm)) (56.4) (26.6) (8.22) (2.13) (0.76)24 hour peel N/D N/D 3.29 1.53 0.817(lbs/in (14.6) (6.81) (3.63)(N/25.4 mm))Shear (min) 259 22 1242 1796 40Tg (°C) N/D -19.8 -15.7 -16.5 -20G’ 6.13 x105 1.71 x 105 1.92 X106 3.96 x10“ 9.32 x 105(dynes/cmz (6.13 X104) (1.71x104) (1.92 x105) (3.96 X105) (9.32 x 104)(Pa))Tensile (psi N/D N/D 192 79 24(MPa) (1.32) (0.54) (0.17)-40-CA 02264875 1999-02-23W0 98/10017 PCT/US97/15534Tables Six and Seven show that substantially random ethylene/styreneinterpolymers having from 39 to 65, preferably from 45 to 55 weight percentstyrene can be formulated to give low tack pressure sensitive adhesive formulationswith improved creep resistance when compared to styrene block copolymerformulations.Tackifier Screening StudyThe tackifiers evaluated in the study, as well as properties obtained fromtrade literature, are set forth in the following Table Eight:Table EightTackifier Manufacturer Feedstock Mn Tg DACP MMAPCloud CloudECR 165 Exxon Aromaticlcycloaliphatic 59Escorez 5380 Exxon Cycloaliphatic 160 35ECR 149B Exxon Hydrogenated C5-C6 48ECR 179 Exxon Hydrogenated 57CycloaliphaticWingtack 86 Goodyear Aromatic Modified C5 37Wingtack 95 Goodyear C5 Hydrocarbon 59Hercotac 1 149 Hercules AliphaticlAromatic (C5-C9) 850 45 24 68Piccotex 75 Hercules Copolymer Modified Styrene 680 29 <-50 1Piccotex 100 Hercules Copolymer Modified Styrene 1200 42 -50 6Regalrez 3102 Hercules Hydrogenated Styrenic 875 51 -30 24Kristalex 3070 Hercules Copolymer of pure 580 27 <-50 0.4monomerPiccolastic A5 Hercules Styrenic Monomers 360 -28 <-50 -4Piccolastic A75 Hercules Styrenic Monomers 670 28 <-50 6Regalite R101 Hercules Hydrogenated Hydrocarbon 44Foral 85 Hercules Rosin Ester 35Staybelite Ester Hercules Hydrogenated Wood Rosin 2910Eastotac H100E Eastman Modified C5 49Piccotac 95 Hercules C5 Hydrocarbon 800 43 49 95* DACP Cloud point reflects polarity of the resin, with lower valuesindicating a higher degree of polarity. MMAP cloud point is a value whichreflects resin aromatic compatibility, with lower values indicating a greaterdegree of aromaticity.Formulations were prepared and evaluated, with the formulationsemployed and the resultant properties being set forth in the following TableNine.-41-CA 02264875 1999-02-23PCT/US97/15534W0 98/100173.:: 3333 3.: 3:3 3.3. 33:. 333 3.3:. 333: 3.:. 2: m2:.._ os83_...m3.:: 3333 3.:. 33: 33.3. 3:: 333 3.3. 833 3.:. 2: 3: .233. 2.35.533.3: 3333 3.3. 333 3.3. .33.. 333 3...: 3333 :3 2: 2: Eon.3.33. 3333 3.:. 333 3.: 33: 2.3 3.3:. 33:3 3.: 2: 3333 33.335.3:3. 333:. 3.:. 2: 33.3. 33: 33.3 3.3: 333: 3.3 2: 33 3.83.3: 3333 3.3. 32. 3.: 3.33 333 3.3:. 3333 :3 2.: 33:3 33.33333.3: 33.33 3.: 333 3.3. 333 $3 3...: :::3 3.: 2.: :23. 2.333.3.33. 33:3 3.3. 333 3.3. 333 333 3.33. 3333 33+m3:.3 3.:: 3:3 333. u_.33_o8E33.3. :.: :: 33.3. 3.33 33.. 3.33 2.33 3...... 3.33 23333.3 3.33. 3:3 3... o_.3m_o8_n_3.3: 3.33 3.:. 333 3.:. 33: :33 3.3:. 3.333 3.: 2: 3333 33.335.3.3: 3333 3.3. 333 3.: 3:3 333 3.3:. 33:3 3.3- 2: 33:3 32.33333.33. 33:: 3.3:. 333: 3. 2:: 333 3.33. 3333 :3 2.: 2: §o8E3.33. 3333 3.3. :33 3.: 333 333 3.:3. 3333 3.3 2: 33 323853.3: 3333 3.3. 333 3.: :8 333 3.3: 3333 3o+m3...3 33.3 2: 3:.:: osouax39333.3 33.3 2: 33 ._8.3=_>>3.3: 3:33 3.: 38 3.3. 333 333 3.3:. 333: 3o+m33.3 33.3 2: 33 ._u3.3:__>>3.3: 3333 3.:. 33: 3.3. 3:: 333: 3.::. 33: 21333.3 2..:: 2: 3333 328333.33. 2:3 3.:. 333 3.: :3: 3:3: 3:3. 3333 23333.3 33.3 2: 33: mom3.3: 3333 3.3. 333 3.: 333 3.3 3.3:. 3333 2.+m33.3 33.3 2.: 33: mom3.33. 3333 3.3. 333 3.3. 33:. 333 3.:: 3.33: 3o+m3.3.3 3:3 2: m3:.: mom3.33. 3333 3.:. :33 3.:. 33: 83: 3.3: 3:3: 33+m33.: 33.3 2: 33.33 32833.3.33. 3333 3.3. ::3 3.: 333 333 3.3:. 3:33 3o+m33.3 3:3 2: 33: mom3.33. :32 3.3. 3.33 3.:. :33 38: 3.3.3. 333 33+m:3.: 8.3:.2.33:2. 3:329... .~Eo.mo:>_u.2332. .33. .333... 33. m:_%os_ .33. 3=__6o_2 .. xmem :3 .332. 33. 2.3 .3 Ø.. E3mmmE.m:o._. 3:39.33. com .cmu._wa oo_. co_.3m:o_m X22 m__m:o.p .0 920 m._. Own. .m_._v_um.r D. ..oE..om._.352 3.3.33-42-W0 98/10017CA 02264875 1999-02-23PCT/US97/15534Table Nine shows that a wide variety of tackifier structures can improve thetensile properties of substantially random interpolymers. Tackifiers from the rosinester, wood rosin, pure monomer, C5-C9, aromatic modified C5, partially hydrogenatedC5-C9, and cycloaliphatic families have been shown to be effective. Of particular andunexpected note in Table Nine is that the combination of, for instance, 100 parts oftackifier with 100 parts of the substantially random interpolymer components resultsin materials having much higher tensile strengths than the substantially randominterpolymer alone, preferably a maximum tensile strength of at least twice, morepreferably at least three times as great as that of the substantially random interpolymeralone.Glass Transition Temperature Adjustment for High Styrene Content PolymersA substantially random interpolymer of ethylene and styrene having from 73.7to 74.9 weight percent styrene and a melt index (I2) of 1 g/10 minutes, is melt blendedwith the indicated amount of Endexm pure monomer resin, available from Hercules.The formulations tested, and the glass transition temperature of the resultantformulations, are set forth in the following Table Ten.Table TenSample No. Weight percent Substantially Weight percent Glass TransitionRandom Interpolymer Tackifier Temperature (°C)Comparative 100 0 22.]Ex. DEx. 24 90 10 23.6Ex. 25 80 20 25.6Ex. 26 70 30 27.7The data set forth in Table Ten illustrates the use of a tackifier to raise theglass transition temperature of a high styrene containing interpolymer to levels aboveambient temperature.-43-CA 02264875 1999-02-23W0 98/10017 PCT/US97/15534These and other embodiments will be readily ascertained by one skilledin the art. Accordingly, the subject invention is to be limited only by thefollowing Claims.

Claims (18)

1. A composition comprising from 5 to 95 weight percent of at least one substantially random interpolymer of ethylene and a vinylidene aromatic monomer or a hindered aliphatic vinylidene monomer and optionally at least one C3-C20 .alpha.-olefin monomer, wherein the substantially random interpolymer comprises from 1-65 mole percent of the vinylidene aromatic monomer or hindered aliphatic vinylidene monomer, and from 5 to 95 weight percent of at least one tackifier.

2. The composition of Claim 1, wherein the at least one substantially random interpolymer is an interpolymer of ethylene and a vinylidene aromatic monomer represented by the following formula:

wherein R1 is selected from the group of radicals consisting of hydrogen and alkyl radicals containing three carbons or less, and Ar is a phenyl group or a phenyl group substituted with from 1 to 5 substituents selected from the group consisting of halo, C1-4 alkyl, and C1-4 haloalkyl.

3. The composition of Claim 1, wherein the substantially random interpolymer is an interpolymer of ethylene, a vinylidene aromatic monomer or a hindered aliphatic vinylidene monomer, and at least one third monomer selected from the group consisting of C3-C20 .alpha.-olefins and norbornene.

4. The compositions of Claim 1, wherein the substantially random interpolymer is an interpolymer of ethylene, a vinylidene aromatic monomer, and optionally at least one third monomer selected from the group consisting of C3-C20 a-olefins and norbornene.

5. The composition of Claim 1, wherein the composition comprises from 25 to 95 weight percent of the substantially random interpolymer and from 5 to 75 weight percent of at least one tackifier.

6. The composition of any of the preceding claims, wherein the at least one tackifier is selected from the group consisting of wood rosin, tall oil derivatives, cyclopentadiene derivatives, natural and synthetic terpenes, terpene-phenolics, styrenela-methyl styrene resins, and mixed aliphatic-aromatic tackifying resins.

7. The composition of Claim 1, wherein the composition further comprises from 5 to 75 weight percent of at least one modifying or extending composition selected from the group consisting of paraffinic waxes, crystalline polyethylene waxes, ultralow molecular weight ethylene polymers, homogeneous linear or substantially linear ethylene/.alpha.-olefin interpolymers, polystyrene, styrene block copolymers, ethylene vinyl acetate, and amorphous polyolefins.

8. The composition of Claim 1, wherein the composition comprises from 1 to 60 weight percent of one or more processing aids selected from the group consisting of phthalate esters, natural oils, paraffinic oils, naphthenic oils, and aromatic oils.

9. The composition of any of the preceding claims, in the form of an adhesive, layer of a multilayer food packaging structure, coating, sealant or molded article, calendared article, or extruded article.

10. An adhesive which comprises from 5 to 95 weight percent of at least one substantially random interpolymer of ethylene and a vinylidene aromatic monomer or a hindered aliphatic vinylidene monomer and optionally at least one C3-C20 .alpha.-olefin monomer, wherein the substantially random interpolymer comprises from 1-65 mole percent of the vinylidene aromatic monomer or hindered aliphatic vinylidene monomer, and wherein the adhesive further comprises from 95 to 5 weight percent of at least one second component selected from the group consisting of tackifiers, waxes, homogeneous linear or substantially linear ethylene/.alpha.-olefin interpolymers, ultra-low molecular weight ethylene polymers, processing aids, and mixtures thereof.

11. The adhesive of Claim 10, wherein the substantially random interpolymer comprises from 25 to 65 weight percent of the vinylidene aromatic monomer or hindered aliphatic vinylidene monomer.

12. The adhesive of Claim 10 or 11, wherein the adhesive comprises a plurality of substantially random interpolymer components which differ in the amount of vinylidene aromatic monomer or hindered aliphatic vinylidene monomer content, which differ in molecular weight, or which differ in both the amount of vinylidene aromatic monomer or hindered aliphatic vinylidene monomer content and in molecular weight.

13. The adhesive of Claim 12, which comprises:
(a) 5 to 75 weight percent of a substantially random interpolymer of ethylene and at least one vinylidene aromatic comonomer or hindered aliphatic vinylidene comonomer, which interpolymer has an Mn of greater than about 10,000 and comprises from 5 to less than 25 mole percent of the at least one vinylidene aromatic comonomer or hindered aliphatic vinylidene comonomer;
(b) from 5 to 75 weight percent of a substantially random interpolymer of ethylene and at least one vinylidene aromatic comonomer or hindered aliphatic vinylidene comonomer, which interpolymer has an Mn of less than about 8,200 and comprises from 1 to less than 5 mole percent of the at least one vinylidene aromatic comonomer or hindered aliphatic vinylidene comonomer; and (c) from 5 to 75 weight percent of a substantially random interpolymer of ethylene and at least one vinylidene aromatic comonomer or hindered aliphatic vinylidene comonomer, which interpolymer has an Mn of less than about 8,200 and comprises at least 25 mole percent of the at least one vinylidene aromatic comonomer or hindered aliphatic vinylidene comonomer.

14. The adhesive of any of Claims 10 - 13, wherein the substantially random interpolymer is an interpolymer of ethylene, at least one vinylidene aromatic monomer, and optionally at least one .alpha.-olefin monomer.

15. The adhesive of any of Claims 10 - 14, as applied to a substrate selected from the group consisting of a package, carton, bookbinding, tape, label, decal, bandage, decorative sheet, protective sheet, ceramic tile, vinyl tile, vinyl flooring, carpet backing, nonwoven fabric, woven fabric, personal hygiene device placement strip, sun control film, gasket, caulk, wood, or veneer.

16. A coextruded or laminated multilayer film, in which at least one layer comprises an adhesive comprising at least one substantially random interpolymer of ethylene and a vinylidene aromatic monomer or a hindered aliphatic vinylidene monomer and optionally at least one C3-C20 .alpha.-olefin monomer.

17. The coextruded or laminated multilayer film of Claim 16 in which the adhesive is adhered to a metal foil.

18. A tape comprising a substrate to which has been applied an adhesive comprising:
a. from 40 to 60 weight percent of a substantially random interpolymer of ethylene and a vinylidene aromatic monomer or a hindered vinylidene aromatic monomer and optionally at least one C3-C20 .alpha.-olefin monomer, said substantially random interpolymer comprising from 25 to 65 weight percent of the vinylidene aromatic monomer or hindered aliphatic vinylidene monomer, b. from 40 to 60 weight percent of a tackifier, and c. from 0 to 10 weight percent of a processing aid, wherein the adhesive is characterized as having a storage modulus (G1) at 25°C of from 2 x 10 5 to 5 x 10 6 dynes/cm2 (0.2 to 5 MPa).