CA2232066A1 - Silicone rubber compositions incorporating silicon-treated carbon blacks - Google Patents
Silicone rubber compositions incorporating silicon-treated carbon blacks Download PDFInfo
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K3/00—Use of inorganic substances as compounding ingredients
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K9/00—Use of pretreated ingredients
- C08K9/04—Ingredients treated with organic substances
- C08K9/06—Ingredients treated with organic substances with silicon-containing compounds
Abstract
Silicone rubber compositions are disclosed including a silicone polymer and a silicon-treated carbon black. The silicon-treated carbon blacks include a silicon-containing compound that is distributed through at least a portion of the carbon black aggegrate. The silicon-treated carbon black is incorporated within a silicone rubber composition as an alternative reinforcing and extending filler, imparting higher hardness to elastomers formed from the composition, when compared to silicone rubber compositions incorporating an untreated carbon black.
Description
PCT~US96/14583 W O 97/lO~91 - 1 -SILICON~ RUBBER COMPOSITIONS INCORPORATI~G
SILICON-TREATED CARBON BLACK~;
BACKGRO~ND OF THE INVENTION
Field of the Invention:
The present invention is directed to silicone rubber compositions and. more particularly, to silicone rubber compositions incorporating silicon-treated carbon blacks and processes for making the same '~ Description of the Related Art:
Silicone rubber compositions are used in a wide varietv of applications due to their superior and unique properties relative to other organic elastomers over a wide temperature range For example. silicone rubber compositions provide superior heat resistance compared to other elastomers Moreover. silicone rubbers have low electrical conductivity and. therefore. excellent incnl~lting properties. particularly under ~vet conditions In addition, silicone rubbers have good chemical. fuel. and oil rf si~t~nce and are weatherable and resistant to ozone attack It is believed that these properties of silicone rubber compositions are due to the unusual molecular structure of tlle polymer.
which typically consists of dimethyl siloxane units A typical silicone rubber composition contains a silicone polvmer rein~orcing and e~ten~linl~ fillers. processing aids or softeners to plasticize and retard crepe hardening, ~0 additives. colorants. and one or more curing agents The silicone rubber composition may be compounded by methods known to those skilled in the art ntili7int conventional process eyuipment. such as extruders. Dough mixers. Banbury mixers and two-roll mills Not~,virhct~nfling the above-noted properties pure silicone rubber poiymers. or polydimethyl siloxanes (also called ''~urns '), are weak elastomers As a result although '5 silicone polymers may be used alone. rubber fabricators ol'ten compound silicone rubber elastomers from silicone gums or bases that contain reinforcing and/or e~cten~ling fillers.
In addition. these fillers are added to silicone rubber to increase their hardness and reduce their sti~kin~c~
W O 97/10291 PCTnJS96/14583 Various fine particle silicas are commonly used as rheology control agents to provide easy application and retention of an extruded shape during curing. Fumed silica also is the rnost commonly used reinforcing filler, providing superior reinforcement~ and increased hardness. tensile. and elongation in silicone rubber elastomers. Typically, the reinforcing silica is incorporated into the silicone polymer prior to vulcanization. The high purity of fumed silica provides the silicone rubber composition with excellent physical and insulating properties Depending on the desired properties and the end use application. between about 5.0 and about 40 0 percent. by weight. fumed silica is typically used in silicone rubber compositions.
In addition to fumed silica, precipitated silicas mav be used as reinforcing fillers to provide silicone rubber compositions with moderately high reinforcement and improved physical properties such as tensile strength and elongation. In addition to fumed and precipitated silicas other materials are used as semi-reinforcing or extending fillers. as well as processing aids. additives. and colorants. to obtain an optimum balance of physical properties. costs~ and processability For example, zinc oxide is used as a colorant and as a plasticizer, imparting heat conductivity, tack and adhesive properties to a rubber composition. Similarly, red iron oxide can be used as colorant and as a stabilizer against heat aging. Carbon black provides silicone rubber compositions with electrical conductivity, and is an additive and colorant that is known to provide moderate reinforcement Processing aids are often add to highly reinforcing silica fillers to provide a softening or plasticizing effect. In addition. the shelf life of the compounded rubber is increased by slowing the crepe-hardening effect in the silicone rubber that occurs as a result of bonding of the polymer and the reinforcing filler.
')5 Finally, typical silicone rubber compositions include one or more curing agents including peroxides. Among the variety of peroxide curing agents. not one can be used for all types of silicone polymers. For example, aroyl peroxides may be considered general-purpose curing agents in that they will cure both non-vinyl and vinyl-cont~ininp silicone polymers However, these agents are not suitable in all fabrication procedures. In addition. vinyl-specific peroxides such as dicumyl peroxide, and others. may also be used to vulcanize silicone rubber W O 97/10291 PCTnJS96/14583 As noted above~ in addition to being used as an additive and coloranL carbon black may also be used to provide moderate reinforcement in silicone rubber compositions.
However~ carbon black is known to inhibit cure with non-vinyl and vinyl-cont~ining silicone polymers in addition to reducing the thermal stability of silicone rubber compositions. These disadvantages tend to limit the use of carbon black to applications requiring electrically conductive or semi-conductive rubbers and/or as a colorant.
In applications where the high to moderately-high reinforcement provided by fumed and precipitated silicas is not required in silicone rubber applications. a need remains for alternative fillers and additives tllat provide the desired level of reinforcement and physical properties. such as hardness. tensile strength and elongation. In addition. alternative fillers and additives are desired to reduce compounding costs and enhance processability of silicone rubber compositions.
SUMMARY OF THE TNVENTI()N
Accordingly, the present invention is directed to silicone rubber compositions ;ncluding a silicone polymer and a silicon-treated carbon blacl;. The silicon-treated carbon blacks include a silicon-cont~ining region that is either primarily distributed through at least a portion of the carbon black aggregate. or at the surface of the carbon black aggregate. The silicon-treated carbon blac~; contains between about ().1 and about 25.0 percent silicon. by weight.
~0 In a silicone rubber composition~ including a silicone polymer and a silicon-treated carbon black. the silicon-treated carbon black that is used as an alternative reinforcing filler, or as an additive~ imparts higher hardness to silicone elastomers formed from the composition~ when compared to silicone rubber compositions cont~ining an untreated carbon black.
~5 Other objects and features of the present invention will become apparent from the following detailed description.
W O 97/10291 PC~US96/14583 DET~TT Fl ) DFSCRIPTIC)N OF THE INVENTION
The present invention is directed to silicone rubber compositions. including a silicone polymer and a silicon-treated carbon black. which result in silicone elastomers having desirable physical properties. The silicon-treated carbon blacks include a silicon-containing species. including but not limited to. oxides and carbides of silicon. that is distributed tllrough at least a portion of the carbon black aggregate as an intrinsic part of the carbon black The silicon-treated carbon black may be incorporated within a silicone rubber composition as an alternative reinforcing and extending filler or as an additive.
In a silicone rubber composition, including a silicone polymer and a silicon-treated carbon black. the silicon-treated carbon black imparts higher hardness (Shore A) to silicone elastomers forrned from the composition, when compared to silicone rubber compositions contz-ining an untreated carbon black.
As is generally known to those skilled in the art. carbon blacks are produced in a furnace-type reactor by pyrolyzing a hydrocarbon feedstock with hot combustion gases.
The carbon black produced exists in the forrn of aggregates of carbon black particles.
Similarly, silica exists in the form of aggregates, which are formed of silica particles that do not generally exist independently of the silica aggregate The silicon-treated carbon black aggregates do not represent a mixture or blend of discrete carbon black and silica aggregates. Rather. the silicon-treated carbon blacks include at least one silicon-cont~ining region. either at the surface or within the carbon black aggregate The silicon-treated carbon blacks may be produced by m~nllf:~turing the carbon blacl; in the presence of silicon-cont~ining compounds Typically. carbon blacks are produced in a staged furnace reactor. including a combustion zone. a converging diameter zone, a restricted diameter feedstock injection zone. and a reaction zone. Hot combustion gases are generated in the combustion zone by contacting a liquid or gaseous fuel with a suitable oxidant stream, such as air, oxygen, or mixtures thereof The oxidant stream may be preheated to facilitate the generation of hot combustion gases. ~ny readily combustible gas, vapor or liquid stream, including natural gas, hydrogen, methane. acetylene. alcohols, or kerosene rnay be used to contact the oxidant in the combustion zone to generate hot combustion gases. Preferably, fuels having high carbon content, such as hydrocarbons, petroleum refinery oils from catalytic cracking operations. as well as coking and olefin manufacturing operation by-products are burned in the combustion zone. The ratio of oxidant to fuel varies with the type of fuel utilized - For example when natural gas is used the ratio may vary between about 10:1 to about 1000:1 Once generated the hot combustion gas stream is directed into the reaction zone.The carbon black feedstock stream is introduced into the reactor in the injection zone.
Typically, the feedstock is injected into the hot combustion gas stream through nozles designed for optimum distribution of the fuel A single- or bi-fluid nozzle may be used to atomize the fuel. The carbon black is then produced by pyrolysis. or partial combustion.
in the reaction zone as the feedstock and the hot combustion gases are mixed. A cooling fluid. such as water. is then sprayed into the gas stream. containing the formed carbon black particles~ in a quench zone that is positioned downstream of the reaction zone. The quench is used to decrease the reaction rate and cool the carbon black particles. The quench stream is positioned a predetermined distance from the reaction zone; alternatively~
a plurality of quench streams may be positioned throughout the reactor After the carbon black is sufficiently cooled the product is separated and recovered by conventional methods.
The silicon-treated carbon blacks are produced bv introducin~ a vo!~tili7~hle silicon-conn~ining compound into the carbon black reactor at a point upstream of the quench zone Prei'erably, the silicon-cont~ining compound is volatilizable at carbon black reactor temperatures. Such compounds include. for ex:~mple. alkoxy silicates. including tetraethoxy orthosilicate (TEOS) and tetramethoxy orthosilicate. silanes. including tetrachloro silane and trichloro methylsilane. and mixtures thereof. and volatile silicone polymers. including octamethyl-cyclotetrasiloxane (OMTS) It has been found that the ~5 silicon concentration on the carbon black is determined by the flow rate of the silicon-cont~ining compound into the reactor The silicon concentration on the carbon black may be as high as commercially feasible to obtain a reinforcing filler that optimizes physical properties. cost. and processability of a silicone rubber composition Typically. there is between about 0.1 and about ~5.0 percent silicon. by weight. on the carbon black;
preferably, about 0.5 and about ~5 0 percent silicon. bv weight: and most preferably. there is between about 6.0 and about ~5 0 percent silicon. by weight. on the carbon black.
The silicon-contzlinin?~ compound may be thoroughly premixed with the carbon black feedstock and introduced into the reactor through the feedstock injection zone.
Alternatively, the silicon-cont~ining compound may be introduced into the reactor separately, either upstrearn or downstream from the feedstock injection zone. The silicon-contz~ining compound however~ must be introduced upstream from the quench zone.
Upon vol~tili~tion~ and exposure to the high reactor temperatures. the silicon-cont:linin~
compound decomposes within the reaction zone and forms the silicon-treated carbon black. such that silica (or other silicon-cont~ining species) becomes an inherent part of the carbon black.
It has been found that introducing the silicon-cont~ining compound substantiallysimultaneously with the carbon black feedstock results in silicon-treated regions distributed throughout at least a portion of the carbon black aggregate. Alternatively.
introducing the silicon-containing compound into the reaction zone after the formation of the carbon blacl;. and prior to the quench~ results in silicon-treated regions at or near the surface of the carbon black aggregate. The production of~silicon-treated carbon blacks is also disclosed in co-pending U.S. patent application Serial No. 08/446.1~1 entitled ELASTOMERIC COMPOUNDS INCORPORATING SILICON-TREATED CARBON
E~LACKS filed on May '- ~ 1995, which is incorporated herein by reference.
The silicon-treated carbon blacks may be utilized to reinforce any silicone rubber ~0 polymer. As is known to those sl~illed in the art~ depending on the desired properties and end use application~ a variety of silicone polymers can be produced. and certain chemical and physical properties can be enhanced~ by replacing a portion of the methyl-contz~ining groups in the polydimethyl siloxane chain with phenyl-cont~ining groups~ vinyl-cont~ining groups, fluorine-cont~ining groups, phenvl- and vinyl-cont~ining groups~ and '~S mixtures thereof. For example~ dimethyl silicone rubber tends to become stif~below -60~F. It has been found that the low temperature flexibility may be improved by substitution of only five percent of the methyl groups with phenyl groups in the polymer chain. This substitution lowers the crystallization temperature, allowing use of the silicone rubber to temperatures below -130~F. It has also been found that less than 0.5 percent of a vinyl-cont~ining group~ such as methylvinyldichloro silane~ results in a low compression set silicone polymer that requires less peroxide curing agent to cure. Finally.
it has been found that the replacement of one methyl group on each silicon atom in the CA 02232066 l998-03-l3 W O97/10291 PCTrUS96/14583 polymer chain with a polar group~ such as trifluoropropyk reduces swelling in aliphatic and aromatic hydrocarbons.
As noted silicone rubber compositions typicallv include reinforcing and/or extending fillers processing aids or softeners to plasticize and retard crepe hardening, additives~ colorants and one or more peroxide curing ~gents in addition to the silicone polymer. As noted above~ although fumed silica is the preferred reinforcing filler used in silicone rubber compositions~ the silicon-treated carbon black of the present invention may be used as an alternative reinforcing filler and/or additive to obtain an optimum balance of physical properties~ costs. and processability.
In addition to the reinforcing fillers and additives a variety of curing agents can be used in silicone rubber compositions. C~enerally~ silicone rubber compositions are heat-cured in the presence of an organic peroxide~ such as bis(2~4-dichlorobenzoyl) peroxide~
di-benzoyl peroxide~ tertiary butyl perbenzoate. dicumyl peroxide~ 2~5-dimethyl-2.5-bis(t-butyl peroxy)hexane~ and di-tertiary butyl peroxide. As known to those skilled in the art.
none of the peroxides is a universal curing agent. The aroyl peroxides may be considered general-purpose curing agents in that they will cure non-vinyl and vinyl-cont~ining polymers~ but no one of them can be used in all fabrication procedures. These general purpose peroxide curing agents are used at cure temperatures of between about 220~F
(about 105 ~C) to about 310 ~F (about 155 ~C) in a variety of fabrication procedures. The dialkyl peroxides are considered vinyl-specific peroxide curing agents because they provide good curing onlv with vinyl-containin~r silicone polymers. These curing agents are used to cure silicone rubbers at temperatures between about 300~F (about 150~C) and about 360~F (about 185~C)~ and are generally used in thick-section molding. low compression set compositions. and they may be emploved to vulcanize compositionscont~inin~ carbon black.
The surface of the silicon-treated carbon blacks may be further treated with a silicone fluid and/or a silane prior to incorporation into a silicone rubber composition to reduce any filler-filler association. and/or any filler-polymer bonding, within the silicone compositions. Therefore~ at a given filler loading leveh the silicone rubber elastomer reinforced with a treated silica~ and/or a treated silicon-treated carbon black~ will have lower hardness and modulus. Such treating agents include~ for example, polydimethyl CA 02232066 l99X-03-13 siloxane oils of various molecular weights. dimethyldichloro silane. and ~lisil~7~nes such as hexamethyl ~ ne (HMDZ), and mixtures thereof. which are known treating agentsfor fumed silica. Typically, the surface treatment of the reinforcing filler makes them hydrophobic. and reduces the crepe-hardening effect within the silicone rubber S composition. Any such surface treating agent may be compounded with a silica or the silicon-treated carbon black by methods known to those skilled in the art. Silicone rubber compositions incorporating surface treated fumed silica and/or silicon-treated carbon black have been found to be more extrudable than compositions incorporating untreated fillers.
In addition, the surface treated fillers provide silicone rubber compositions with a shelf-stable base, as well as permittin~ a much higher filler loading level. thereby providing improved reinforcement to the silicone rubber composition.
The silicon-treated carbon blacks mav be used in the four major product categories of silicone rubber compositions: one- and two-component room temperature vulc~ni~tt-s (RTV-I, and RTV-2). heat cured rubber (HCR), and liquid solution rubber (LSR).
Generally, product compositions in each category comprise a silicone polymer~ a reinforcing filler, and a curing (cross-linking) agent. RTV s are used as a wide variety of products including, for example. adhesives. sealants an~ potting compounds. gaskets, encapulants ç~lllking, and molds. The RTV-I products are one-component systems, including a silicone polymer. a filler. an initiator. and an oxime catalyst. which can cure at room temperature and humidity. The RTV-2 products are two-component systems.
including a high viscosity silicone polymer. a low viscosity silicone oil. and a filler~ which can be cured at room temperature and humidity over a predetermined period of time.
HCR s exhibit consistent physical properties over a broad temperature range of about -80~C to about 250~C, including good dielectric properties and physiological inertness. HCR's are used as a wide variety of products including, for example, tubing and hoses. belting, wire-cable insulation. surgical aids and medical implants. fuel-resistant rubber parts, penetration seals, rollers, electrically conducting rubber. fabric coating, and foams. HCR's typically contain about 100 parts of a silicone copolymer. about 40 parts per hundred (phr) of fumed silica, about 2 phr of a peroxide curing agent. and other additives. The silicone composition is then processed bv. for example, compression or transfer molding. extrusion. calendering, and the like. to form a silicone rubber product.
The HCR products are typically cured by crosslinking at temperatures of up to about 1 70~C, and by postcuring at temperatures up to about 250~C.
LSR's are two-part, pumpable fluids that can be processed using low pressure automatic injection molding equipment. These materials cure upon mixing and he~ting and provide silicone rubber products that release easily from molds~ and require little or no post-curing. These products have been found to be resistant to non-polar solvents.
Typically. LSR's are based on pumpable polydimethylsiloxane comprising a small percentage of vinyl groups to enhance curing.
The present invention ~vill be further illustrated by the following examples. which are intended to be illustrative in nature and are not to be considered as limiting the scope of the invention.
~XAMPLE I
Silicon-treated carbon blacks. incorporated into silicone rubber compositions of the present invention~ were prepared using a carbon black furnace reactor. The reactor included an XB-15 burner havin~ a 2 inch transition and a single 0.030 inch oil tip. The reaction zone was 60 inches in length and had an ID of 6 inches. The reactor included injection ports positioned at 9 inches 30 inches and 45 inches al'ter the reactor s transition portion. The water-cooled quench zone included a single port having a #~ nozzle positioned 30 inches from the feedstock injection. The quench temperature was 1150~F.
A summary of the production conditions are set forth in Table I below.
The production conditions were altered by adding a volatilizable silicon-cont~ining compound into the reactor to obtain a silicon-treated carbon black. The flow rate of the vol:~tili7~1e compound was adjusted to alter the weight percent of the silicon on the carbon black. The weight percent of silicon on the treated carbon black was determined by an ashing test~ conducted according to ASTM procedure D-1506. Two samples of J25 silicon-treated carbon black were prepared by introducing a silicon-cont:~ining vol~tili7~ble compound. tetraethoxy silane (TEOS)~ available from Huls America.
Piscataway, New Jersey~ into the hydrocarbon feedstock. For Samples 1 and ~. the TEOS
was added through ( I ) the carbon black feedstock (FS) injection. and (2) the port positioned 9 inches after the transition into the reactor. Samples 3-5 of a silicon-treated W O 97/10291 PCT~US96/14583 carbon black were then prepared by injecting an organo-silicon compound, octamethyl-cyclotetrasiloxane (OMTS). available as "D-4" from Dow Corning Corporation~ Midland, Michigan, into the hydrocarbon feedstock. The D-4 was added (1) with the carbon black feedstocl~ (FS) injections at two feed rates (resulting in 8% and 12% silicon on the carbon black), and (2) through the port positioned 9 inches after the transition into the reactor. A
sixth. Baseline. sample included only carbon black made directly from feedstocl;. and resulted in a carbon black identified by the ASTM designation N~34 (commerciallyavailable as Vulcan~) 7H carbon black. available from Cabot Corporation. Boston.
~i.c~,ichllcetts) .
TABT ,E I
SAMPLE Feedstock' Si Additive AirRate- Nominal Gas Rate Rate Rate (lbs./hr.) (lbs./hr ) (kscfh) (kscfh) 1. g% TEOS~FS 97.4 21.6 13.8Z 1.5 '~. 8% TEOS~9" 116.3 34.9 13.82 1.5 3. 8% D~(~FS 107.9 8.43 13.82 1.5 4. 1''% D-4(~FS 106.1 14 42 13.82 1.5 5. 8%D-4~9" 107.9 8.42 13.82 1 5 6. Baseline 116.3 0 13.82 1.5 ' The feedstock used in all Samples is methylnaphthalene. fed at about 50~F.
Air was preheated to about 800~F
The resulting silicon-treated carbon blacks were analyzed for silicon content. surface area and silicon conversion efficiency In addition. the pH and hydroxyl content were evaluated. These values were then compared to those of Cab-O-Sil~) M-7D and MS-75D
untreated furned silicas (Cabot Corporation) In addition. the BET surface areas and the loss on drying (LOD), were measured for each sample The BET surface area is measured by the adsorption of nitrogen For the fumed silica. Carman surface areas ~CSA) were measured. The CSA is an indirect method to measure structure~ and is cleterlriine~ by air flow at very low pressures over a silica plug. The external surface area (t-Area) was measured for silicon-treated carbon blacks. following the sample preparation andmeasurement procedure described in ASTM D3037 - Method ~ for Nitrogen surface area.
CA 02232066 l998-03-l3 The analytical results for pelleted samples dried in an electric oven are presented in Table II.
TABLF II
SAMPLE wt% Silicon t-Area N,- Si Conv.
in Carbon Area Efficiency Black (m'/g) (%) ( m'/g) l. 8% TEOS~FS 15.9 248.1 434.5 88.7 2. 8% TEOS(~?9 ' 17.6 193.7 276.7 91.0 3. 8% D-4(i~FS 18.9 259.1 496.9 107.8 4. 12% D-4~FS 23.3 260.0 514.5 87.4 ~. 8% D-4(~9 13.4 2~1.0 347.2 87.3 6. Baseline 0.18 246.3 400.5 0.00 SAMPLE pH BET SA C SA LOD OH
(m'/g) (m'/g) 1. 8% TEOS(~FS 6.58 408 0.34 1.39 . 8% TEOS(~9" 6.81 265 0.30 1.84 3. 8% D-4(~.FS 6.76 459 0.26 1.13 4. l2% D-4(~.FS 7.06 486 ().37 1.81 5. 8% D-4~)9' 7.41 327 0.27 1.00 6. Baseline 7.65 380 0.''7 0.68 7. M-7D 4.12 194 109 0.75 2.95 8. MS-75D 4.04 252 132 1.90 3.44 As noted. the pH of each of the silicon-treated carbon blacks is higher than that of - the fumed silicas. The hydroxyl content of the reinforcing filler is an important value in determining the interaction of each with silicone polvmers. The isolated hydroxyl groups on the surface of the fi11er bond with the poiymers. The surface area values are indicative of the degree of branching and symmetry of the aggregate.
CA 02232066 l99X-03-13 F~MPTF II
The silicon-treated carbon blacks prepared in EXAMPLE I were incorporated into HCR silicone rubber compositions utili7ing silicone polymers having (I) no vinyl-cont~ining groups, (II) high vinyl, and (III) low vinyl. Compositions were prepared and evaluated for Shore A hardness. tensile skength (psi), and elongation (%) The evaluated silicone rubber compositions were prepared using a polydimethylvinyl siloxane polymer. The no-vinyl cont~ining polymer used was DowCorning Q4-2735 (ASTM cle~ n~tion VMQ), the low-vinyl contz~ining polymer used was Dow Corning Q4-2901, and the high-vinyl cont~ining silicone polymer used was DowCorning DC410. all available from Dow Corning Corporation, Midland. Michigan. A
processing aid. a hydroxyl-termin~te~l low molecular weight polydimethyl siloxane fluid was incorporated into the evaluated silicone rubber compositions. The processing aid used was Dow Corning, Q4-2737 (ASTM cle~ign~tion MQ). The peroxide catalyst used in the no-vinyl polymer composition was a 50% dispersion of bis(2,4-dichlorobenzoyl) peroxide in silicone fluid, available as Cadox~ TS-S0 organic peroxide, available from Akzo Chemical. Chicago, Illinois. The peroxide catalyst used for the vinyl cont~ining silicone polymer compositions was a 50% dispersion of dicumyl peroxide in silicone fluid.available as DICUP~D R organic peroxide. and DICUP~ 40C organic peroxide. available from Hercules. Inc. Wilmington. Delaware The standard formulation for each groupincluded 100 parts of the silicone polymer. 2 parts peroxide paste. and a variable amount of the processing aid (depending upon the surface area of the silica and its loading level).
The compounding of the silicone rubber compositions was performed in a E laake E~heomix~ 410 mixer. The polymer gum was added to the mixer, and mixed at about 50 rpm for about 10 minlltt-~. When used, the silica reinforcing filler was added with the processing aid. The composition was allowed to mix for about one hour E~eating was then applied for approximately one hour at about 110~C. The peroxide catalyst was then added on a two-roll mill prior to curing the samples. The physical properties of the cured rubber were measured using standard ASTM test procedures. The tensile slabs were cured for five minutes at about 116~C and an additional four hour oven post cure at about 200~C.
The results are reported below in Table III.
W O 97/10291 PCT~US96/14583 The silicone rubber composition l~tili7ing the Dow Corning Q4-2735 silicone polymer was first cured by itself. A second sample was then cured lltili7in~ 40 phr of Cab-O-Sil(~) M-7D untreated fumed silica, which is typical of silica reinforcing agents used by silicone rubber compounders. available from Cabot Corporation. Cab-O-SilDivision, Tuscola~ Illinois. Three other samples were then cured lltili7ing mixtures of the M-7D fumed silica and CanC~rb(~) MT-N990 carbon black available from Witco Corporation~ Houston~ Texas. These mixtures included 35/5 phr. 30/10 phr~ and 25/15 phr silica/carbon black. respectively.
A second group of silicone rubber compositions. including the Dow Corning DC410 high vinyl silicone polymer. ~ere cured using 40 phr of the baseline carbon blacl~
(produced in Example I). 40 phr M-7D untreated f'umed silica. and 40 phr of the silicon-treated carbon black (Sample 4. E~ample 1). Lastly. silicone rubber compositions.
including Dow Corning Q4-2901 low vinyl silicone polymer. were evaluated. These polymers were reinforced utilizing 30 phr of the silicon-treated carbon blacks. and the baseline carbon black. (produced in E~ample 1). as well as with 30 phr M-7D fumed silica.
TABLE III
No vinyl gum: Hardness Tensile Elongation (Shore A) (psi) Cured by itself 16 28 52 40 phr, M-7D 57 1162 253 35/Sphr. M-7D. CanCarb 42 1200 453 30/lOphr, M-7D. CanCarb 20 887 837 25/lSphr, M-7D. CanCarb Did not cure - II. High vinyl gum:
40phr, Baseline 41 522 435 40phr. M-7D Cured but too brittle 40phr. 12%D4@FS Did not cure III. Low vinyl gum:
30 phr~ 8%~EOS(~9" 47 141 145 30 phr. 8%D4(~FS 35 104 513 30 phr.8%D4~9" 35 212 460 30 phr, 8%TEOS(~FS 43 67 45 30 phr,12%D4(~FS 34 54 70 30 phr, Baseline 19 394 88~
30 phr~ M-7D 46 927 379 The results indicate that the silicone polymer having no vinyl groups had the lowest hardness value when cured by itself~ while the highest hardness value resulted when 40 phr of a fumed silica was added.
In the no-vinyl silicone polymer compositions the hardness deteriorated as the level of silica decreased At silica levels of 25 phr the composition did not cure. The high vinyl silicone polymer compositions cured using 40 phr of the Baseline carbon blacl;. The high vinyl system also cured using 40 phr of the M-70 fumed silica but was too brittle~ while the composition using 40 phr of the silicon-treated carbon blacl; (Example I~ Sample 4) did not cure.
The silicon-treated carbon blacks~ added at 30 phr. provided the low-vinyl silicone polymer compositions with higher hardness~ compared to the Baseline untreated carbon black. The 30 phr~ 8% TEOS~9" sample performed similarly to the 30 phr M-7D fumed silica with respect to the hardness property.
It is believed that the silicon-contz~inin~ species in the silicon-treated carbon blacks consists essentially of silica. It is this form of silicon-conf~inin~ species that the interaction with the siloxane groups of the silicone polymer exists~ thereby providing a unique reinforcement in silicone rubber systems.
CA 02232066 l998-03-l3 W O 97/10291 PCTrUS96/14583 EXAMPT,F, III
The silicon-treated carbon blacks prepared in EXAMPLE I were incorporated into silicone rubber compositions in addition to fumed silica reinforcing fillers. Cab-O-Sil M-7D untreated furned silica (Cabot Corporation) was used as the reinforcing filler in equal amounts with each of the silicon-treated carbon blacks prepared in EXAMPLE I, as well as the baseline carbon black. In addition. the effectiveness of the mixed silicon-treated carbon black/fumed silica filler was compared to systems incorporating 40 phr M-7D fumed silica reinforcing filler. Silicone rubber compositions. l-tili7ing the low vinyl polymer composition of Example II were compounded using each of the fillers. Theresulting products were cured and evaluated for Shore A hardness~ tensile strength (psi).
and elongation (%). The results are reported below in Table IV.
TABLE IV
SAMPLE ~ Hardness Tensile Elongation (Shore A) (psi) ( %) 20/20phr M-7D Baseline 36 837 471 20/20phrM-7D. 12%D4@FS 54 297 229 20/20phr M-7D~ 8%TEOS~,9'' 57 443 221 20/70phr M-7D. 8%D4~9~' 56 829 314 20/20phr M-7D~ 8%TEOS@,FS 54 325 236 20/20phr M-7D. 8%D4~FS 46 365 261 40phr HMDZ trt~ 8%TEOS@,9" 47 207 329 40phr M-7D 55 1288 522 30phr M-7D 46 927 379 As expected~ the composition with 40 phr fumed silica had the best overall combination of physical properties~ including hardness~ tensile strength, and elongation.
The composition using a mixture of the baseline carbon black and fumed silica had the lowest hardness values. The silica-doped carbon black cont~ining systems perforrned well with respect to the hardness. Of these~ the samples ~ltili7ing TEOS gave higher hardness values than those using the D-4 material.
FXAMpT.F. IV
A silicon-treated carbon black (8%TEOS~9"), prepared in EXAMPLE I (Sample 2). was treated with hexamethyl ~li.cil~7~ne (HMDZ) prior to being incorporated into a silicone rubber composition. The HMDZ treated silicon-treated carbon black was produced by mixing 200 grams of the silicon-treated carbon black with 8 grams deionized water in a three liter plastic bag. The mixture was allowed to stand overnight. About 40 grams of HMDZ was then added to the mixture, which was allowed to stand overnight.
The treated material was placed in a vented oven, at a temperature of about 125 ~C for approximately 16 hours. The treated product produced was hydrophobic. About 40 phr of l 0 the HMDZ treated silicon-treated carbon black~ and 40 phr M-7D untreated fumed silica.
were incorporated into the low-vinyl silicone polymer of EXAMPLE II. The resultant compositions were evaluated for Shore A hardness. ~ensile strength. and elongation. The results are reported below in Table V.
TABLE V
SAMPLE Hardness Tensile Elongation (Shore A) (psi) 40phr HMDZ trt 8%TEOS~9~' 47 207 329 40phr M-7D 55 1288 522 The HMDZ treated silicon-treated carbon black perforrned well with respect to hardness in the low-vinyl silicone polymer system. As expected, the composition with the fumed silica had the highest hardness. tensile strength and elongation.
Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications mav be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.
What is claimed is:
SILICON-TREATED CARBON BLACK~;
BACKGRO~ND OF THE INVENTION
Field of the Invention:
The present invention is directed to silicone rubber compositions and. more particularly, to silicone rubber compositions incorporating silicon-treated carbon blacks and processes for making the same '~ Description of the Related Art:
Silicone rubber compositions are used in a wide varietv of applications due to their superior and unique properties relative to other organic elastomers over a wide temperature range For example. silicone rubber compositions provide superior heat resistance compared to other elastomers Moreover. silicone rubbers have low electrical conductivity and. therefore. excellent incnl~lting properties. particularly under ~vet conditions In addition, silicone rubbers have good chemical. fuel. and oil rf si~t~nce and are weatherable and resistant to ozone attack It is believed that these properties of silicone rubber compositions are due to the unusual molecular structure of tlle polymer.
which typically consists of dimethyl siloxane units A typical silicone rubber composition contains a silicone polvmer rein~orcing and e~ten~linl~ fillers. processing aids or softeners to plasticize and retard crepe hardening, ~0 additives. colorants. and one or more curing agents The silicone rubber composition may be compounded by methods known to those skilled in the art ntili7int conventional process eyuipment. such as extruders. Dough mixers. Banbury mixers and two-roll mills Not~,virhct~nfling the above-noted properties pure silicone rubber poiymers. or polydimethyl siloxanes (also called ''~urns '), are weak elastomers As a result although '5 silicone polymers may be used alone. rubber fabricators ol'ten compound silicone rubber elastomers from silicone gums or bases that contain reinforcing and/or e~cten~ling fillers.
In addition. these fillers are added to silicone rubber to increase their hardness and reduce their sti~kin~c~
W O 97/10291 PCTnJS96/14583 Various fine particle silicas are commonly used as rheology control agents to provide easy application and retention of an extruded shape during curing. Fumed silica also is the rnost commonly used reinforcing filler, providing superior reinforcement~ and increased hardness. tensile. and elongation in silicone rubber elastomers. Typically, the reinforcing silica is incorporated into the silicone polymer prior to vulcanization. The high purity of fumed silica provides the silicone rubber composition with excellent physical and insulating properties Depending on the desired properties and the end use application. between about 5.0 and about 40 0 percent. by weight. fumed silica is typically used in silicone rubber compositions.
In addition to fumed silica, precipitated silicas mav be used as reinforcing fillers to provide silicone rubber compositions with moderately high reinforcement and improved physical properties such as tensile strength and elongation. In addition to fumed and precipitated silicas other materials are used as semi-reinforcing or extending fillers. as well as processing aids. additives. and colorants. to obtain an optimum balance of physical properties. costs~ and processability For example, zinc oxide is used as a colorant and as a plasticizer, imparting heat conductivity, tack and adhesive properties to a rubber composition. Similarly, red iron oxide can be used as colorant and as a stabilizer against heat aging. Carbon black provides silicone rubber compositions with electrical conductivity, and is an additive and colorant that is known to provide moderate reinforcement Processing aids are often add to highly reinforcing silica fillers to provide a softening or plasticizing effect. In addition. the shelf life of the compounded rubber is increased by slowing the crepe-hardening effect in the silicone rubber that occurs as a result of bonding of the polymer and the reinforcing filler.
')5 Finally, typical silicone rubber compositions include one or more curing agents including peroxides. Among the variety of peroxide curing agents. not one can be used for all types of silicone polymers. For example, aroyl peroxides may be considered general-purpose curing agents in that they will cure both non-vinyl and vinyl-cont~ininp silicone polymers However, these agents are not suitable in all fabrication procedures. In addition. vinyl-specific peroxides such as dicumyl peroxide, and others. may also be used to vulcanize silicone rubber W O 97/10291 PCTnJS96/14583 As noted above~ in addition to being used as an additive and coloranL carbon black may also be used to provide moderate reinforcement in silicone rubber compositions.
However~ carbon black is known to inhibit cure with non-vinyl and vinyl-cont~ining silicone polymers in addition to reducing the thermal stability of silicone rubber compositions. These disadvantages tend to limit the use of carbon black to applications requiring electrically conductive or semi-conductive rubbers and/or as a colorant.
In applications where the high to moderately-high reinforcement provided by fumed and precipitated silicas is not required in silicone rubber applications. a need remains for alternative fillers and additives tllat provide the desired level of reinforcement and physical properties. such as hardness. tensile strength and elongation. In addition. alternative fillers and additives are desired to reduce compounding costs and enhance processability of silicone rubber compositions.
SUMMARY OF THE TNVENTI()N
Accordingly, the present invention is directed to silicone rubber compositions ;ncluding a silicone polymer and a silicon-treated carbon blacl;. The silicon-treated carbon blacks include a silicon-cont~ining region that is either primarily distributed through at least a portion of the carbon black aggregate. or at the surface of the carbon black aggregate. The silicon-treated carbon blac~; contains between about ().1 and about 25.0 percent silicon. by weight.
~0 In a silicone rubber composition~ including a silicone polymer and a silicon-treated carbon black. the silicon-treated carbon black that is used as an alternative reinforcing filler, or as an additive~ imparts higher hardness to silicone elastomers formed from the composition~ when compared to silicone rubber compositions cont~ining an untreated carbon black.
~5 Other objects and features of the present invention will become apparent from the following detailed description.
W O 97/10291 PC~US96/14583 DET~TT Fl ) DFSCRIPTIC)N OF THE INVENTION
The present invention is directed to silicone rubber compositions. including a silicone polymer and a silicon-treated carbon black. which result in silicone elastomers having desirable physical properties. The silicon-treated carbon blacks include a silicon-containing species. including but not limited to. oxides and carbides of silicon. that is distributed tllrough at least a portion of the carbon black aggregate as an intrinsic part of the carbon black The silicon-treated carbon black may be incorporated within a silicone rubber composition as an alternative reinforcing and extending filler or as an additive.
In a silicone rubber composition, including a silicone polymer and a silicon-treated carbon black. the silicon-treated carbon black imparts higher hardness (Shore A) to silicone elastomers forrned from the composition, when compared to silicone rubber compositions contz-ining an untreated carbon black.
As is generally known to those skilled in the art. carbon blacks are produced in a furnace-type reactor by pyrolyzing a hydrocarbon feedstock with hot combustion gases.
The carbon black produced exists in the forrn of aggregates of carbon black particles.
Similarly, silica exists in the form of aggregates, which are formed of silica particles that do not generally exist independently of the silica aggregate The silicon-treated carbon black aggregates do not represent a mixture or blend of discrete carbon black and silica aggregates. Rather. the silicon-treated carbon blacks include at least one silicon-cont~ining region. either at the surface or within the carbon black aggregate The silicon-treated carbon blacks may be produced by m~nllf:~turing the carbon blacl; in the presence of silicon-cont~ining compounds Typically. carbon blacks are produced in a staged furnace reactor. including a combustion zone. a converging diameter zone, a restricted diameter feedstock injection zone. and a reaction zone. Hot combustion gases are generated in the combustion zone by contacting a liquid or gaseous fuel with a suitable oxidant stream, such as air, oxygen, or mixtures thereof The oxidant stream may be preheated to facilitate the generation of hot combustion gases. ~ny readily combustible gas, vapor or liquid stream, including natural gas, hydrogen, methane. acetylene. alcohols, or kerosene rnay be used to contact the oxidant in the combustion zone to generate hot combustion gases. Preferably, fuels having high carbon content, such as hydrocarbons, petroleum refinery oils from catalytic cracking operations. as well as coking and olefin manufacturing operation by-products are burned in the combustion zone. The ratio of oxidant to fuel varies with the type of fuel utilized - For example when natural gas is used the ratio may vary between about 10:1 to about 1000:1 Once generated the hot combustion gas stream is directed into the reaction zone.The carbon black feedstock stream is introduced into the reactor in the injection zone.
Typically, the feedstock is injected into the hot combustion gas stream through nozles designed for optimum distribution of the fuel A single- or bi-fluid nozzle may be used to atomize the fuel. The carbon black is then produced by pyrolysis. or partial combustion.
in the reaction zone as the feedstock and the hot combustion gases are mixed. A cooling fluid. such as water. is then sprayed into the gas stream. containing the formed carbon black particles~ in a quench zone that is positioned downstream of the reaction zone. The quench is used to decrease the reaction rate and cool the carbon black particles. The quench stream is positioned a predetermined distance from the reaction zone; alternatively~
a plurality of quench streams may be positioned throughout the reactor After the carbon black is sufficiently cooled the product is separated and recovered by conventional methods.
The silicon-treated carbon blacks are produced bv introducin~ a vo!~tili7~hle silicon-conn~ining compound into the carbon black reactor at a point upstream of the quench zone Prei'erably, the silicon-cont~ining compound is volatilizable at carbon black reactor temperatures. Such compounds include. for ex:~mple. alkoxy silicates. including tetraethoxy orthosilicate (TEOS) and tetramethoxy orthosilicate. silanes. including tetrachloro silane and trichloro methylsilane. and mixtures thereof. and volatile silicone polymers. including octamethyl-cyclotetrasiloxane (OMTS) It has been found that the ~5 silicon concentration on the carbon black is determined by the flow rate of the silicon-cont~ining compound into the reactor The silicon concentration on the carbon black may be as high as commercially feasible to obtain a reinforcing filler that optimizes physical properties. cost. and processability of a silicone rubber composition Typically. there is between about 0.1 and about ~5.0 percent silicon. by weight. on the carbon black;
preferably, about 0.5 and about ~5 0 percent silicon. bv weight: and most preferably. there is between about 6.0 and about ~5 0 percent silicon. by weight. on the carbon black.
The silicon-contzlinin?~ compound may be thoroughly premixed with the carbon black feedstock and introduced into the reactor through the feedstock injection zone.
Alternatively, the silicon-cont~ining compound may be introduced into the reactor separately, either upstrearn or downstream from the feedstock injection zone. The silicon-contz~ining compound however~ must be introduced upstream from the quench zone.
Upon vol~tili~tion~ and exposure to the high reactor temperatures. the silicon-cont:linin~
compound decomposes within the reaction zone and forms the silicon-treated carbon black. such that silica (or other silicon-cont~ining species) becomes an inherent part of the carbon black.
It has been found that introducing the silicon-cont~ining compound substantiallysimultaneously with the carbon black feedstock results in silicon-treated regions distributed throughout at least a portion of the carbon black aggregate. Alternatively.
introducing the silicon-containing compound into the reaction zone after the formation of the carbon blacl;. and prior to the quench~ results in silicon-treated regions at or near the surface of the carbon black aggregate. The production of~silicon-treated carbon blacks is also disclosed in co-pending U.S. patent application Serial No. 08/446.1~1 entitled ELASTOMERIC COMPOUNDS INCORPORATING SILICON-TREATED CARBON
E~LACKS filed on May '- ~ 1995, which is incorporated herein by reference.
The silicon-treated carbon blacks may be utilized to reinforce any silicone rubber ~0 polymer. As is known to those sl~illed in the art~ depending on the desired properties and end use application~ a variety of silicone polymers can be produced. and certain chemical and physical properties can be enhanced~ by replacing a portion of the methyl-contz~ining groups in the polydimethyl siloxane chain with phenyl-cont~ining groups~ vinyl-cont~ining groups, fluorine-cont~ining groups, phenvl- and vinyl-cont~ining groups~ and '~S mixtures thereof. For example~ dimethyl silicone rubber tends to become stif~below -60~F. It has been found that the low temperature flexibility may be improved by substitution of only five percent of the methyl groups with phenyl groups in the polymer chain. This substitution lowers the crystallization temperature, allowing use of the silicone rubber to temperatures below -130~F. It has also been found that less than 0.5 percent of a vinyl-cont~ining group~ such as methylvinyldichloro silane~ results in a low compression set silicone polymer that requires less peroxide curing agent to cure. Finally.
it has been found that the replacement of one methyl group on each silicon atom in the CA 02232066 l998-03-l3 W O97/10291 PCTrUS96/14583 polymer chain with a polar group~ such as trifluoropropyk reduces swelling in aliphatic and aromatic hydrocarbons.
As noted silicone rubber compositions typicallv include reinforcing and/or extending fillers processing aids or softeners to plasticize and retard crepe hardening, additives~ colorants and one or more peroxide curing ~gents in addition to the silicone polymer. As noted above~ although fumed silica is the preferred reinforcing filler used in silicone rubber compositions~ the silicon-treated carbon black of the present invention may be used as an alternative reinforcing filler and/or additive to obtain an optimum balance of physical properties~ costs. and processability.
In addition to the reinforcing fillers and additives a variety of curing agents can be used in silicone rubber compositions. C~enerally~ silicone rubber compositions are heat-cured in the presence of an organic peroxide~ such as bis(2~4-dichlorobenzoyl) peroxide~
di-benzoyl peroxide~ tertiary butyl perbenzoate. dicumyl peroxide~ 2~5-dimethyl-2.5-bis(t-butyl peroxy)hexane~ and di-tertiary butyl peroxide. As known to those skilled in the art.
none of the peroxides is a universal curing agent. The aroyl peroxides may be considered general-purpose curing agents in that they will cure non-vinyl and vinyl-cont~ining polymers~ but no one of them can be used in all fabrication procedures. These general purpose peroxide curing agents are used at cure temperatures of between about 220~F
(about 105 ~C) to about 310 ~F (about 155 ~C) in a variety of fabrication procedures. The dialkyl peroxides are considered vinyl-specific peroxide curing agents because they provide good curing onlv with vinyl-containin~r silicone polymers. These curing agents are used to cure silicone rubbers at temperatures between about 300~F (about 150~C) and about 360~F (about 185~C)~ and are generally used in thick-section molding. low compression set compositions. and they may be emploved to vulcanize compositionscont~inin~ carbon black.
The surface of the silicon-treated carbon blacks may be further treated with a silicone fluid and/or a silane prior to incorporation into a silicone rubber composition to reduce any filler-filler association. and/or any filler-polymer bonding, within the silicone compositions. Therefore~ at a given filler loading leveh the silicone rubber elastomer reinforced with a treated silica~ and/or a treated silicon-treated carbon black~ will have lower hardness and modulus. Such treating agents include~ for example, polydimethyl CA 02232066 l99X-03-13 siloxane oils of various molecular weights. dimethyldichloro silane. and ~lisil~7~nes such as hexamethyl ~ ne (HMDZ), and mixtures thereof. which are known treating agentsfor fumed silica. Typically, the surface treatment of the reinforcing filler makes them hydrophobic. and reduces the crepe-hardening effect within the silicone rubber S composition. Any such surface treating agent may be compounded with a silica or the silicon-treated carbon black by methods known to those skilled in the art. Silicone rubber compositions incorporating surface treated fumed silica and/or silicon-treated carbon black have been found to be more extrudable than compositions incorporating untreated fillers.
In addition, the surface treated fillers provide silicone rubber compositions with a shelf-stable base, as well as permittin~ a much higher filler loading level. thereby providing improved reinforcement to the silicone rubber composition.
The silicon-treated carbon blacks mav be used in the four major product categories of silicone rubber compositions: one- and two-component room temperature vulc~ni~tt-s (RTV-I, and RTV-2). heat cured rubber (HCR), and liquid solution rubber (LSR).
Generally, product compositions in each category comprise a silicone polymer~ a reinforcing filler, and a curing (cross-linking) agent. RTV s are used as a wide variety of products including, for example. adhesives. sealants an~ potting compounds. gaskets, encapulants ç~lllking, and molds. The RTV-I products are one-component systems, including a silicone polymer. a filler. an initiator. and an oxime catalyst. which can cure at room temperature and humidity. The RTV-2 products are two-component systems.
including a high viscosity silicone polymer. a low viscosity silicone oil. and a filler~ which can be cured at room temperature and humidity over a predetermined period of time.
HCR s exhibit consistent physical properties over a broad temperature range of about -80~C to about 250~C, including good dielectric properties and physiological inertness. HCR's are used as a wide variety of products including, for example, tubing and hoses. belting, wire-cable insulation. surgical aids and medical implants. fuel-resistant rubber parts, penetration seals, rollers, electrically conducting rubber. fabric coating, and foams. HCR's typically contain about 100 parts of a silicone copolymer. about 40 parts per hundred (phr) of fumed silica, about 2 phr of a peroxide curing agent. and other additives. The silicone composition is then processed bv. for example, compression or transfer molding. extrusion. calendering, and the like. to form a silicone rubber product.
The HCR products are typically cured by crosslinking at temperatures of up to about 1 70~C, and by postcuring at temperatures up to about 250~C.
LSR's are two-part, pumpable fluids that can be processed using low pressure automatic injection molding equipment. These materials cure upon mixing and he~ting and provide silicone rubber products that release easily from molds~ and require little or no post-curing. These products have been found to be resistant to non-polar solvents.
Typically. LSR's are based on pumpable polydimethylsiloxane comprising a small percentage of vinyl groups to enhance curing.
The present invention ~vill be further illustrated by the following examples. which are intended to be illustrative in nature and are not to be considered as limiting the scope of the invention.
~XAMPLE I
Silicon-treated carbon blacks. incorporated into silicone rubber compositions of the present invention~ were prepared using a carbon black furnace reactor. The reactor included an XB-15 burner havin~ a 2 inch transition and a single 0.030 inch oil tip. The reaction zone was 60 inches in length and had an ID of 6 inches. The reactor included injection ports positioned at 9 inches 30 inches and 45 inches al'ter the reactor s transition portion. The water-cooled quench zone included a single port having a #~ nozzle positioned 30 inches from the feedstock injection. The quench temperature was 1150~F.
A summary of the production conditions are set forth in Table I below.
The production conditions were altered by adding a volatilizable silicon-cont~ining compound into the reactor to obtain a silicon-treated carbon black. The flow rate of the vol:~tili7~1e compound was adjusted to alter the weight percent of the silicon on the carbon black. The weight percent of silicon on the treated carbon black was determined by an ashing test~ conducted according to ASTM procedure D-1506. Two samples of J25 silicon-treated carbon black were prepared by introducing a silicon-cont:~ining vol~tili7~ble compound. tetraethoxy silane (TEOS)~ available from Huls America.
Piscataway, New Jersey~ into the hydrocarbon feedstock. For Samples 1 and ~. the TEOS
was added through ( I ) the carbon black feedstock (FS) injection. and (2) the port positioned 9 inches after the transition into the reactor. Samples 3-5 of a silicon-treated W O 97/10291 PCT~US96/14583 carbon black were then prepared by injecting an organo-silicon compound, octamethyl-cyclotetrasiloxane (OMTS). available as "D-4" from Dow Corning Corporation~ Midland, Michigan, into the hydrocarbon feedstock. The D-4 was added (1) with the carbon black feedstocl~ (FS) injections at two feed rates (resulting in 8% and 12% silicon on the carbon black), and (2) through the port positioned 9 inches after the transition into the reactor. A
sixth. Baseline. sample included only carbon black made directly from feedstocl;. and resulted in a carbon black identified by the ASTM designation N~34 (commerciallyavailable as Vulcan~) 7H carbon black. available from Cabot Corporation. Boston.
~i.c~,ichllcetts) .
TABT ,E I
SAMPLE Feedstock' Si Additive AirRate- Nominal Gas Rate Rate Rate (lbs./hr.) (lbs./hr ) (kscfh) (kscfh) 1. g% TEOS~FS 97.4 21.6 13.8Z 1.5 '~. 8% TEOS~9" 116.3 34.9 13.82 1.5 3. 8% D~(~FS 107.9 8.43 13.82 1.5 4. 1''% D-4(~FS 106.1 14 42 13.82 1.5 5. 8%D-4~9" 107.9 8.42 13.82 1 5 6. Baseline 116.3 0 13.82 1.5 ' The feedstock used in all Samples is methylnaphthalene. fed at about 50~F.
Air was preheated to about 800~F
The resulting silicon-treated carbon blacks were analyzed for silicon content. surface area and silicon conversion efficiency In addition. the pH and hydroxyl content were evaluated. These values were then compared to those of Cab-O-Sil~) M-7D and MS-75D
untreated furned silicas (Cabot Corporation) In addition. the BET surface areas and the loss on drying (LOD), were measured for each sample The BET surface area is measured by the adsorption of nitrogen For the fumed silica. Carman surface areas ~CSA) were measured. The CSA is an indirect method to measure structure~ and is cleterlriine~ by air flow at very low pressures over a silica plug. The external surface area (t-Area) was measured for silicon-treated carbon blacks. following the sample preparation andmeasurement procedure described in ASTM D3037 - Method ~ for Nitrogen surface area.
CA 02232066 l998-03-l3 The analytical results for pelleted samples dried in an electric oven are presented in Table II.
TABLF II
SAMPLE wt% Silicon t-Area N,- Si Conv.
in Carbon Area Efficiency Black (m'/g) (%) ( m'/g) l. 8% TEOS~FS 15.9 248.1 434.5 88.7 2. 8% TEOS(~?9 ' 17.6 193.7 276.7 91.0 3. 8% D-4(i~FS 18.9 259.1 496.9 107.8 4. 12% D-4~FS 23.3 260.0 514.5 87.4 ~. 8% D-4(~9 13.4 2~1.0 347.2 87.3 6. Baseline 0.18 246.3 400.5 0.00 SAMPLE pH BET SA C SA LOD OH
(m'/g) (m'/g) 1. 8% TEOS(~FS 6.58 408 0.34 1.39 . 8% TEOS(~9" 6.81 265 0.30 1.84 3. 8% D-4(~.FS 6.76 459 0.26 1.13 4. l2% D-4(~.FS 7.06 486 ().37 1.81 5. 8% D-4~)9' 7.41 327 0.27 1.00 6. Baseline 7.65 380 0.''7 0.68 7. M-7D 4.12 194 109 0.75 2.95 8. MS-75D 4.04 252 132 1.90 3.44 As noted. the pH of each of the silicon-treated carbon blacks is higher than that of - the fumed silicas. The hydroxyl content of the reinforcing filler is an important value in determining the interaction of each with silicone polvmers. The isolated hydroxyl groups on the surface of the fi11er bond with the poiymers. The surface area values are indicative of the degree of branching and symmetry of the aggregate.
CA 02232066 l99X-03-13 F~MPTF II
The silicon-treated carbon blacks prepared in EXAMPLE I were incorporated into HCR silicone rubber compositions utili7ing silicone polymers having (I) no vinyl-cont~ining groups, (II) high vinyl, and (III) low vinyl. Compositions were prepared and evaluated for Shore A hardness. tensile skength (psi), and elongation (%) The evaluated silicone rubber compositions were prepared using a polydimethylvinyl siloxane polymer. The no-vinyl cont~ining polymer used was DowCorning Q4-2735 (ASTM cle~ n~tion VMQ), the low-vinyl contz~ining polymer used was Dow Corning Q4-2901, and the high-vinyl cont~ining silicone polymer used was DowCorning DC410. all available from Dow Corning Corporation, Midland. Michigan. A
processing aid. a hydroxyl-termin~te~l low molecular weight polydimethyl siloxane fluid was incorporated into the evaluated silicone rubber compositions. The processing aid used was Dow Corning, Q4-2737 (ASTM cle~ign~tion MQ). The peroxide catalyst used in the no-vinyl polymer composition was a 50% dispersion of bis(2,4-dichlorobenzoyl) peroxide in silicone fluid, available as Cadox~ TS-S0 organic peroxide, available from Akzo Chemical. Chicago, Illinois. The peroxide catalyst used for the vinyl cont~ining silicone polymer compositions was a 50% dispersion of dicumyl peroxide in silicone fluid.available as DICUP~D R organic peroxide. and DICUP~ 40C organic peroxide. available from Hercules. Inc. Wilmington. Delaware The standard formulation for each groupincluded 100 parts of the silicone polymer. 2 parts peroxide paste. and a variable amount of the processing aid (depending upon the surface area of the silica and its loading level).
The compounding of the silicone rubber compositions was performed in a E laake E~heomix~ 410 mixer. The polymer gum was added to the mixer, and mixed at about 50 rpm for about 10 minlltt-~. When used, the silica reinforcing filler was added with the processing aid. The composition was allowed to mix for about one hour E~eating was then applied for approximately one hour at about 110~C. The peroxide catalyst was then added on a two-roll mill prior to curing the samples. The physical properties of the cured rubber were measured using standard ASTM test procedures. The tensile slabs were cured for five minutes at about 116~C and an additional four hour oven post cure at about 200~C.
The results are reported below in Table III.
W O 97/10291 PCT~US96/14583 The silicone rubber composition l~tili7ing the Dow Corning Q4-2735 silicone polymer was first cured by itself. A second sample was then cured lltili7in~ 40 phr of Cab-O-Sil(~) M-7D untreated fumed silica, which is typical of silica reinforcing agents used by silicone rubber compounders. available from Cabot Corporation. Cab-O-SilDivision, Tuscola~ Illinois. Three other samples were then cured lltili7ing mixtures of the M-7D fumed silica and CanC~rb(~) MT-N990 carbon black available from Witco Corporation~ Houston~ Texas. These mixtures included 35/5 phr. 30/10 phr~ and 25/15 phr silica/carbon black. respectively.
A second group of silicone rubber compositions. including the Dow Corning DC410 high vinyl silicone polymer. ~ere cured using 40 phr of the baseline carbon blacl~
(produced in Example I). 40 phr M-7D untreated f'umed silica. and 40 phr of the silicon-treated carbon black (Sample 4. E~ample 1). Lastly. silicone rubber compositions.
including Dow Corning Q4-2901 low vinyl silicone polymer. were evaluated. These polymers were reinforced utilizing 30 phr of the silicon-treated carbon blacks. and the baseline carbon black. (produced in E~ample 1). as well as with 30 phr M-7D fumed silica.
TABLE III
No vinyl gum: Hardness Tensile Elongation (Shore A) (psi) Cured by itself 16 28 52 40 phr, M-7D 57 1162 253 35/Sphr. M-7D. CanCarb 42 1200 453 30/lOphr, M-7D. CanCarb 20 887 837 25/lSphr, M-7D. CanCarb Did not cure - II. High vinyl gum:
40phr, Baseline 41 522 435 40phr. M-7D Cured but too brittle 40phr. 12%D4@FS Did not cure III. Low vinyl gum:
30 phr~ 8%~EOS(~9" 47 141 145 30 phr. 8%D4(~FS 35 104 513 30 phr.8%D4~9" 35 212 460 30 phr, 8%TEOS(~FS 43 67 45 30 phr,12%D4(~FS 34 54 70 30 phr, Baseline 19 394 88~
30 phr~ M-7D 46 927 379 The results indicate that the silicone polymer having no vinyl groups had the lowest hardness value when cured by itself~ while the highest hardness value resulted when 40 phr of a fumed silica was added.
In the no-vinyl silicone polymer compositions the hardness deteriorated as the level of silica decreased At silica levels of 25 phr the composition did not cure. The high vinyl silicone polymer compositions cured using 40 phr of the Baseline carbon blacl;. The high vinyl system also cured using 40 phr of the M-70 fumed silica but was too brittle~ while the composition using 40 phr of the silicon-treated carbon blacl; (Example I~ Sample 4) did not cure.
The silicon-treated carbon blacks~ added at 30 phr. provided the low-vinyl silicone polymer compositions with higher hardness~ compared to the Baseline untreated carbon black. The 30 phr~ 8% TEOS~9" sample performed similarly to the 30 phr M-7D fumed silica with respect to the hardness property.
It is believed that the silicon-contz~inin~ species in the silicon-treated carbon blacks consists essentially of silica. It is this form of silicon-conf~inin~ species that the interaction with the siloxane groups of the silicone polymer exists~ thereby providing a unique reinforcement in silicone rubber systems.
CA 02232066 l998-03-l3 W O 97/10291 PCTrUS96/14583 EXAMPT,F, III
The silicon-treated carbon blacks prepared in EXAMPLE I were incorporated into silicone rubber compositions in addition to fumed silica reinforcing fillers. Cab-O-Sil M-7D untreated furned silica (Cabot Corporation) was used as the reinforcing filler in equal amounts with each of the silicon-treated carbon blacks prepared in EXAMPLE I, as well as the baseline carbon black. In addition. the effectiveness of the mixed silicon-treated carbon black/fumed silica filler was compared to systems incorporating 40 phr M-7D fumed silica reinforcing filler. Silicone rubber compositions. l-tili7ing the low vinyl polymer composition of Example II were compounded using each of the fillers. Theresulting products were cured and evaluated for Shore A hardness~ tensile strength (psi).
and elongation (%). The results are reported below in Table IV.
TABLE IV
SAMPLE ~ Hardness Tensile Elongation (Shore A) (psi) ( %) 20/20phr M-7D Baseline 36 837 471 20/20phrM-7D. 12%D4@FS 54 297 229 20/20phr M-7D~ 8%TEOS~,9'' 57 443 221 20/70phr M-7D. 8%D4~9~' 56 829 314 20/20phr M-7D~ 8%TEOS@,FS 54 325 236 20/20phr M-7D. 8%D4~FS 46 365 261 40phr HMDZ trt~ 8%TEOS@,9" 47 207 329 40phr M-7D 55 1288 522 30phr M-7D 46 927 379 As expected~ the composition with 40 phr fumed silica had the best overall combination of physical properties~ including hardness~ tensile strength, and elongation.
The composition using a mixture of the baseline carbon black and fumed silica had the lowest hardness values. The silica-doped carbon black cont~ining systems perforrned well with respect to the hardness. Of these~ the samples ~ltili7ing TEOS gave higher hardness values than those using the D-4 material.
FXAMpT.F. IV
A silicon-treated carbon black (8%TEOS~9"), prepared in EXAMPLE I (Sample 2). was treated with hexamethyl ~li.cil~7~ne (HMDZ) prior to being incorporated into a silicone rubber composition. The HMDZ treated silicon-treated carbon black was produced by mixing 200 grams of the silicon-treated carbon black with 8 grams deionized water in a three liter plastic bag. The mixture was allowed to stand overnight. About 40 grams of HMDZ was then added to the mixture, which was allowed to stand overnight.
The treated material was placed in a vented oven, at a temperature of about 125 ~C for approximately 16 hours. The treated product produced was hydrophobic. About 40 phr of l 0 the HMDZ treated silicon-treated carbon black~ and 40 phr M-7D untreated fumed silica.
were incorporated into the low-vinyl silicone polymer of EXAMPLE II. The resultant compositions were evaluated for Shore A hardness. ~ensile strength. and elongation. The results are reported below in Table V.
TABLE V
SAMPLE Hardness Tensile Elongation (Shore A) (psi) 40phr HMDZ trt 8%TEOS~9~' 47 207 329 40phr M-7D 55 1288 522 The HMDZ treated silicon-treated carbon black perforrned well with respect to hardness in the low-vinyl silicone polymer system. As expected, the composition with the fumed silica had the highest hardness. tensile strength and elongation.
Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications mav be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.
What is claimed is:
Claims (21)
1. A silicone rubber composition comprising a silicone polymer and a silicon-treated carbon black.
2. The composition of claim 1, further comprising a fumed silica.
3. The composition of claim 1, further comprising a processing aid.
4. The composition of claim 2, further comprising a curing agent.
5. The composition of claim 3, further comprising a curing agent.
6. The composition of claim 5, wherein the curing agent is an organic peroxide.
7. The composition of claim 6, wherein said peroxide is selected from the group consisting of bis(2,4-dichlorobenzoyl) peroxide, di-benzoyl peroxide, tertiary butyl perbenzoate, dicumyl peroxide, 2,5-dimethyl-2,5-bis(t-butyl peroxy)hexane, di-tertiary butyl peroxide, and mixtures thereof.
8. The composition of claim 1, wherein said silicone polymer is a polydimethyl siloxane.
9. The composition of claim 8, wherein said polydimethyl siloxane contains groups selected from the group consisting of phenyl-, vinyl-, fluorine- and mixtures thereof.
10. The composition of claim 1, wherein said silicon-treated carbon black contains between about 0.1 and about 25.0 percent silicon, by weight.
11. The composition of claim 10, wherein said silicon-treated carbon black contains between about 0.5 and about 25.0 percent silicon, by weight.
12. The composition of claim 11, wherein said silicon-treated carbon black contains between about 6.0 and about 25.0 percent silicon, by weight.
13. The composition of claim 1, wherein said silicon-treated carbon black includes silicon-containing regions primarily at the surface of the carbon black aggregate.
14. The composition of claim 1, wherein said silicon-treated carbon black includes silicon-containing regions distributed throughout the carbon black aggregate.
15. The composition of claim 1, wherein said silicon-treated carbon black is further treated with a silicone fluid.
16. The composition of claim 1, wherein said silicon-treated carbon black is further treated with a silane.
17. The composition of claim 16. wherein said silane is selected from the group consisting of polydimethyl siloxane oil, dimethyldichloro silane, disilazanes, and mixtures thereof.
18. The composition of claim 17. wherein said silane is hexamethyl disilazane.
19. The composition of claim 1, wherein said composition is a HCR.
20. The composition of claim 1, wherein said composition is a LSR.
21. The composition of claim 1, wherein said composition is a RTV.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US08/529,234 US6020402A (en) | 1995-09-15 | 1995-09-15 | Silicone rubber compositions incorporating silicon-treated carbon blacks |
| US08/529,234 | 1995-09-15 | ||
| PCT/US1996/014583 WO1997010291A1 (en) | 1995-09-15 | 1996-09-12 | Silicone rubber compositions incorporating silicon-treated carbon blacks |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2232066A1 true CA2232066A1 (en) | 1997-03-20 |
Family
ID=24109071
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002232066A Abandoned CA2232066A1 (en) | 1995-09-15 | 1996-09-12 | Silicone rubber compositions incorporating silicon-treated carbon blacks |
Country Status (8)
| Country | Link |
|---|---|
| US (2) | US6020402A (en) |
| EP (2) | EP1152028B1 (en) |
| AT (2) | ATE213753T1 (en) |
| AU (1) | AU7157596A (en) |
| CA (1) | CA2232066A1 (en) |
| DE (2) | DE69619536T2 (en) |
| ES (1) | ES2252116T3 (en) |
| WO (1) | WO1997010291A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112480719A (en) * | 2020-11-17 | 2021-03-12 | 唐山黑猫炭黑有限责任公司 | Nano carbon black with metallic luster and preparation method thereof |
Families Citing this family (26)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5869550A (en) * | 1995-05-22 | 1999-02-09 | Cabot Corporation | Method to improve traction using silicon-treated carbon blacks |
| US6020402A (en) * | 1995-09-15 | 2000-02-01 | Cabot Corporation | Silicone rubber compositions incorporating silicon-treated carbon blacks |
| US5747562A (en) * | 1996-06-14 | 1998-05-05 | Cabot Corporation | Ink and coating compositions containing silicon-treated carbon black |
| US6017980A (en) * | 1997-03-27 | 2000-01-25 | Cabot Corporation | Elastomeric compounds incorporating metal-treated carbon blacks |
| US5904762A (en) | 1997-04-18 | 1999-05-18 | Cabot Corporation | Method of making a multi-phase aggregate using a multi-stage process |
| DE19727526A1 (en) * | 1997-06-30 | 1999-01-07 | Bayer Ag | Crosslinkable liquid silicone rubber mixtures, a process for their production, a process for the production of electrically conductive contact points and their use |
| US6614039B2 (en) | 1999-06-23 | 2003-09-02 | Brad C. Hollander | Hermetically sealed ultraviolet light source |
| US7081225B1 (en) | 1999-07-20 | 2006-07-25 | Hollander Brad C | Methods and apparatus for disinfecting and sterilizing fluid using ultraviolet radiation |
| US6469089B2 (en) * | 1999-10-08 | 2002-10-22 | Cabot Corporation | Elastomeric compounds with improved wet skid resistance and methods to improve wet skid resistance |
| US20030160399A1 (en) * | 2001-06-05 | 2003-08-28 | Jerold P. Lyons. | Method and apparatus for providing a modular shielded enclosure |
| JP2010529502A (en) * | 2007-06-08 | 2010-08-26 | キャボット コーポレイション | Carbon black, toner, composite material, and production method thereof |
| DE102007044302A1 (en) * | 2007-09-17 | 2009-03-19 | Bühler PARTEC GmbH | Process for dispersing finely divided inorganic powders in liquid media using reactive siloxanes |
| EP2231758A1 (en) * | 2007-12-21 | 2010-09-29 | Cabot Corporation | Filler system including densed fumed metal oxide |
| US8263524B1 (en) * | 2009-05-11 | 2012-09-11 | Nei, Corp. | Environmentally benign sorbents for removing mercury from flue gas |
| US8263525B1 (en) * | 2009-05-27 | 2012-09-11 | Nei Corporation | Nanoparticle sorbent for efficient mercury remediation from contaminated water |
| JP5756604B2 (en) | 2009-07-21 | 2015-07-29 | リー ヘイル ダニー | Compositions for removable gel applications for nails and methods for their use |
| US8263677B2 (en) * | 2009-09-08 | 2012-09-11 | Creative Nail Design, Inc. | Removable color gel basecoat for artificial nail coatings and methods therefore |
| US8492454B2 (en) | 2009-10-05 | 2013-07-23 | Creative Nail Design, Inc. | Removable color layer for artificial nail coatings and methods therefore |
| US8541482B2 (en) * | 2009-10-05 | 2013-09-24 | Creative Nail Design, Inc. | Removable multilayer nail coating system and methods therefore |
| GB2474474A (en) * | 2009-10-14 | 2011-04-20 | Dow Corning | Silicone rubber compositions |
| CN103501755A (en) | 2011-03-07 | 2014-01-08 | 创意指甲设计公司 | Compositions and methods for UV-curable cosmetic nail coatings |
| US8435707B2 (en) | 2011-06-16 | 2013-05-07 | Cabot Corporation | Toner additive comprising carbon-silica dual phase particles |
| WO2013152133A1 (en) * | 2012-04-03 | 2013-10-10 | Sennits, Llc | Dual comb hair accessory having planar stretch elements with embedded decorative designs |
| US20150116444A1 (en) * | 2013-10-31 | 2015-04-30 | Palo Alto Research Center Incorporated | Imaging Blanket with Dispersed Carbon and Micro-Texture Surface |
| EP3218068B1 (en) * | 2014-11-10 | 2019-05-01 | The Procter and Gamble Company | Personal care compositions and hangers |
| EP4067306A1 (en) | 2021-03-26 | 2022-10-05 | Apollo Tyres Ltd. | Method for preparing a silica embedded carbon black composite aggregate and composite aggregate prepared thereby |
Family Cites Families (70)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1999573A (en) | 1930-08-29 | 1935-04-30 | William W Odell | Special carbon black |
| US2375795A (en) | 1941-12-22 | 1945-05-15 | Phillips Petroleum Co | Carbon black process |
| US2564700A (en) | 1947-04-25 | 1951-08-21 | Phillips Petroleum Co | Production of carbon black |
| US2632713A (en) | 1948-10-29 | 1953-03-24 | Phillips Petroleum Co | Carbon black process |
| US3094428A (en) | 1957-06-07 | 1963-06-18 | Monsanto Chemicals | Composition of metal oxides and carbon black |
| GB910309A (en) | 1958-07-22 | 1962-11-14 | Dunlop Rubber Co | Rubber compositions |
| US3188225A (en) | 1961-02-22 | 1965-06-08 | Commw Scient Ind Res Org | Method of producing carbon-silicate complexes |
| BE626217A (en) | 1961-12-18 | 1900-01-01 | ||
| US3290165A (en) | 1963-04-01 | 1966-12-06 | Huber Corp J M | Surface modified pigments |
| FR1459019A (en) | 1965-08-09 | 1966-04-29 | Fr Des Silicates Speciaux Sifr | Surface modified pigments |
| US3390006A (en) | 1965-08-30 | 1968-06-25 | Huber Corp J M | Method of making carbon black/silica pigment |
| DE1952094U (en) | 1966-05-21 | 1966-12-22 | Heinrich Kissling Fabrik Fuer | SWITCH ARM OR ACTUATOR LEVER WITH ATTACHED LABELS. |
| CH487232A (en) | 1966-06-24 | 1970-03-15 | Degussa | Process for the production of a gray pigment |
| FR1499348A (en) | 1966-09-12 | 1967-10-27 | Huber Corp J M | Superficially modified pigment and its preparation process |
| GB1213186A (en) * | 1968-04-08 | 1970-11-18 | Huber Corp J M | Method of making carbon black/silica pigment |
| DE1792148A1 (en) | 1968-07-27 | 1971-10-21 | Degussa | Improved pre-wetted pigment preparations |
| US3622650A (en) | 1969-02-04 | 1971-11-23 | Cabot Corp | Rubber reinforcing compositions |
| DE1948443C3 (en) * | 1969-09-25 | 1981-02-19 | Degussa Ag, 6000 Frankfurt | Process for the production of highly dispersed, homogeneous mixtures consisting of or containing silicon dioxide and carbon black |
| US3716513A (en) | 1970-07-16 | 1973-02-13 | O Burke | Silica pigments and elastomer-silica pigment masterbatches and production processes relating thereto |
| US3689452A (en) | 1970-07-16 | 1972-09-05 | Burke Oliver W Jun | Elastomer-silica pigment masterbatches and production processes relating thereto |
| GB1363428A (en) | 1970-11-12 | 1974-08-14 | Electricity Council | Concrete |
| US3997356A (en) | 1971-08-17 | 1976-12-14 | Deutsche Gold- Und Silber-Scheideanstalt Vormals Roessler | Reinforcing additive |
| GB1363429A (en) | 1972-02-11 | 1974-08-14 | Electricity Council | Concrete |
| US4108679A (en) | 1976-11-22 | 1978-08-22 | Ebonex Corporation | Pigment composition containing elemental carbon and process of making the same |
| US4221693A (en) | 1979-03-02 | 1980-09-09 | Getson John C | Composition free of surface cure inhibition and method for preparing the same |
| DE2910991C3 (en) | 1979-03-21 | 1982-01-21 | Degussa Ag, 6000 Frankfurt | Process for the production of mixed granules from carbon black, water and light filler and its use |
| US4211578A (en) | 1979-06-08 | 1980-07-08 | J. M. Huber Corporation | Method of producing a carbon black silica pigment |
| DE2933346C2 (en) | 1979-08-17 | 1982-07-01 | Degussa Ag, 6000 Frankfurt | Silane / filler preparations, processes for their production and application of the same |
| DE3502494A1 (en) | 1984-01-27 | 1985-08-08 | Toyoda Gosei Co., Ltd., Haruhi, Aichi | Modified carbon black |
| FR2562534B1 (en) | 1984-04-06 | 1986-06-27 | Rhone Poulenc Chim Base | NOVEL PRECIPITATED SILICA WITH IMPROVED MORPHOLOGICAL CHARACTERS, PROCESS FOR OBTAINING THE SAME AND APPLICATION THEREOF, IN PARTICULAR AS FILLER |
| JPS61101470A (en) | 1984-10-22 | 1986-05-20 | 品川白煉瓦株式会社 | Two-component refractory composition for spray construction |
| US4670059A (en) | 1986-02-11 | 1987-06-02 | Hewlett Packard Company | Increased solubility of carbon black |
| JPH068366B2 (en) | 1987-04-23 | 1994-02-02 | 株式会社ブリヂストン | Rubber composition for tires |
| US4785047A (en) * | 1987-07-30 | 1988-11-15 | Dow Corning Corporation | Method for preparing clear polyorganosiloxane elastomers |
| US4929391A (en) * | 1988-07-20 | 1990-05-29 | Dow Corning Corporation | Electrically conductive silicon compositions |
| KR0157322B1 (en) | 1989-03-07 | 1998-12-01 | 모토야마 가즈오 | Method of hose-metal fitting attachment |
| DE4023537A1 (en) * | 1990-07-25 | 1992-01-30 | Degussa | CHEMICALLY MODIFIED ROUGS WITH ORGANOSILICIUM COMPOUNDS, METHOD FOR THE PRODUCTION THEREOF AND THEIR USE |
| FR2673187B1 (en) | 1991-02-25 | 1994-07-01 | Michelin & Cie | RUBBER COMPOSITION AND TIRE COVERS BASED ON SAID COMPOSITION. |
| DE4119959A1 (en) | 1991-06-18 | 1992-12-24 | Degussa | METHOD FOR PRODUCING VULCANIZABLE, RUSSELED PLASTIC AND RUBBER MIXTURES |
| JP3254708B2 (en) | 1991-12-27 | 2002-02-12 | 三菱化学株式会社 | Magnetic recording media |
| DE4222372A1 (en) | 1992-07-08 | 1994-01-13 | Merck Patent Gmbh | Carbon black pigments |
| US5294253A (en) | 1992-11-06 | 1994-03-15 | Hydril Company | Carbon black system and improved rubber stock |
| US5430087A (en) | 1993-09-02 | 1995-07-04 | Hydril Company | Carbon black pair with different particle size and improved rubber stock |
| CA2104529A1 (en) | 1993-06-18 | 1994-12-19 | Paul Harry Sandstrom | Tire with silica reinforced tread |
| CA2104537A1 (en) | 1993-06-18 | 1994-12-19 | Paul Harry Sandstrom | Silica reinforced rubber composition |
| JP2854787B2 (en) * | 1993-08-31 | 1999-02-03 | 信越化学工業株式会社 | Method for producing silicone rubber composition |
| JP3384861B2 (en) * | 1994-03-08 | 2003-03-10 | ジーイー東芝シリコーン株式会社 | Conductive silicone rubber composition and method for producing the same |
| DE19503906A1 (en) | 1994-03-30 | 1995-10-05 | Merck Patent Gmbh | Carbonaceous pigments |
| JP2999128B2 (en) | 1994-09-02 | 2000-01-17 | 横浜ゴム株式会社 | Pneumatic tire |
| US5597950A (en) | 1994-11-03 | 1997-01-28 | The Regents Of The University Of California Office Of Technology Transfer | Surfactant monitoring by foam generation |
| JP2788212B2 (en) | 1994-11-11 | 1998-08-20 | 横浜ゴム株式会社 | Surface-treated carbon black and rubber composition using the same |
| IL116379A (en) | 1994-12-15 | 2003-12-10 | Cabot Corp | Aqueous inks and coatings containing modified carbon products |
| IL116377A (en) | 1994-12-15 | 2003-05-29 | Cabot Corp | Reaction of carbon black with diazonium salts, resultant carbon black products and their uses |
| DE19500674A1 (en) | 1995-01-12 | 1996-07-18 | Degussa | Surface modified pyrogenic mixed oxides, process for their production and use |
| US5580919A (en) | 1995-03-14 | 1996-12-03 | The Goodyear Tire & Rubber Company | Silica reinforced rubber composition and use in tires |
| US5869550A (en) | 1995-05-22 | 1999-02-09 | Cabot Corporation | Method to improve traction using silicon-treated carbon blacks |
| ZA964060B (en) * | 1995-05-22 | 1996-08-27 | Cabot Corp | Elastomeric compounds incorporating silicon-treated carbon blacks |
| BR9609105A (en) * | 1995-05-22 | 1999-02-02 | Cabor Corp | Elastomeric compounds incorporating silicon-treated carbon blacks |
| HUP9802554A3 (en) | 1995-05-22 | 1999-04-28 | Cabot Corp | Elastomeric compounds incorporating partially coated carbon blacks |
| US5830930A (en) | 1995-05-22 | 1998-11-03 | Cabot Corporation | Elastomeric compounds incorporating silicon-treated carbon blacks |
| US5877238A (en) | 1995-05-22 | 1999-03-02 | Cabot Corporation | Elastomeric compounds incorporating silicon-treated carbon blacks and coupling agents |
| US5622557A (en) | 1995-05-22 | 1997-04-22 | Cabot Corporation | Mineral binders colored with silicon-containing carbon black |
| US6108364A (en) | 1995-08-31 | 2000-08-22 | Qualcomm Incorporated | Time division duplex repeater for use in a CDMA system |
| US5948835A (en) | 1995-09-15 | 1999-09-07 | Cabot Corporation | Silicon-treated carbon black/elastomer formulations and applications |
| US6020402A (en) | 1995-09-15 | 2000-02-01 | Cabot Corporation | Silicone rubber compositions incorporating silicon-treated carbon blacks |
| US5883179A (en) | 1995-10-25 | 1999-03-16 | The Yokohama Rubber Co., Ltd. | Rubber composition comprising carbon black surface treated with silica |
| JP3526676B2 (en) | 1995-10-25 | 2004-05-17 | 横浜ゴム株式会社 | Manufacturing method of surface-treated carbon black for rubber reinforcement |
| FR2740708B1 (en) | 1995-11-08 | 1997-12-26 | Rhone Poulenc Chimie | PROCESS FOR THE PREPARATION OF A RUTHENIUM / TIN BI-METAL CATALYST AND ITS USE IN A PROCESS FOR THE PREPARATION OF ALDEHYDES AND THEIR DERIVATIVES |
| CA2266887A1 (en) | 1996-09-25 | 1998-04-02 | Cabot Corporation | Pre-coupled silicon-treated carbon blacks |
| US5904762A (en) | 1997-04-18 | 1999-05-18 | Cabot Corporation | Method of making a multi-phase aggregate using a multi-stage process |
-
1995
- 1995-09-15 US US08/529,234 patent/US6020402A/en not_active Expired - Fee Related
-
1996
- 1996-09-12 DE DE69619536T patent/DE69619536T2/en not_active Expired - Fee Related
- 1996-09-12 EP EP01116078A patent/EP1152028B1/en not_active Expired - Lifetime
- 1996-09-12 EP EP96932995A patent/EP0850268B1/en not_active Expired - Lifetime
- 1996-09-12 WO PCT/US1996/014583 patent/WO1997010291A1/en active IP Right Grant
- 1996-09-12 ES ES01116078T patent/ES2252116T3/en not_active Expired - Lifetime
- 1996-09-12 AU AU71575/96A patent/AU7157596A/en not_active Abandoned
- 1996-09-12 DE DE69635464T patent/DE69635464T2/en not_active Expired - Fee Related
- 1996-09-12 CA CA002232066A patent/CA2232066A1/en not_active Abandoned
- 1996-09-12 AT AT96932995T patent/ATE213753T1/en not_active IP Right Cessation
- 1996-09-12 AT AT01116078T patent/ATE310047T1/en not_active IP Right Cessation
-
1999
- 1999-11-12 US US09/438,897 patent/US6191194B1/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112480719A (en) * | 2020-11-17 | 2021-03-12 | 唐山黑猫炭黑有限责任公司 | Nano carbon black with metallic luster and preparation method thereof |
| CN112480719B (en) * | 2020-11-17 | 2021-12-28 | 唐山黑猫炭黑有限责任公司 | Nano carbon black with metallic luster and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| ATE213753T1 (en) | 2002-03-15 |
| ATE310047T1 (en) | 2005-12-15 |
| EP0850268A1 (en) | 1998-07-01 |
| AU7157596A (en) | 1997-04-01 |
| ES2252116T3 (en) | 2006-05-16 |
| DE69619536D1 (en) | 2002-04-04 |
| EP1152028A3 (en) | 2001-11-21 |
| EP0850268B1 (en) | 2002-02-27 |
| DE69635464T2 (en) | 2006-08-03 |
| EP1152028A2 (en) | 2001-11-07 |
| US6020402A (en) | 2000-02-01 |
| DE69635464D1 (en) | 2005-12-22 |
| DE69619536T2 (en) | 2002-10-17 |
| WO1997010291A1 (en) | 1997-03-20 |
| US6191194B1 (en) | 2001-02-20 |
| EP1152028B1 (en) | 2005-11-16 |
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