CA1091842A - Unsaturated polyester molding compositions - Google Patents
Unsaturated polyester molding compositionsInfo
- Publication number
- CA1091842A CA1091842A CA306,571A CA306571A CA1091842A CA 1091842 A CA1091842 A CA 1091842A CA 306571 A CA306571 A CA 306571A CA 1091842 A CA1091842 A CA 1091842A
- Authority
- CA
- Canada
- Prior art keywords
- weight
- composition
- epihalohydrin
- monomer
- polymer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
- C08G63/02—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds
- C08G63/12—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds derived from polycarboxylic acids and polyhydroxy compounds
- C08G63/52—Polycarboxylic acids or polyhydroxy compounds in which at least one of the two components contains aliphatic unsaturation
- C08G63/54—Polycarboxylic acids or polyhydroxy compounds in which at least one of the two components contains aliphatic unsaturation the acids or hydroxy compounds containing carbocyclic rings
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F299/00—Macromolecular compounds obtained by interreacting polymers involving only carbon-to-carbon unsaturated bond reactions, in the absence of non-macromolecular monomers
- C08F299/02—Macromolecular compounds obtained by interreacting polymers involving only carbon-to-carbon unsaturated bond reactions, in the absence of non-macromolecular monomers from unsaturated polycondensates
- C08F299/04—Macromolecular compounds obtained by interreacting polymers involving only carbon-to-carbon unsaturated bond reactions, in the absence of non-macromolecular monomers from unsaturated polycondensates from polyesters
-
- 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
- C08K7/00—Use of ingredients characterised by shape
- C08K7/16—Solid spheres
- C08K7/18—Solid spheres inorganic
- C08K7/20—Glass
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L63/00—Compositions of epoxy resins; Compositions of derivatives of epoxy resins
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L67/00—Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Compositions of derivatives of such polymers
- C08L67/06—Unsaturated polyesters
Abstract
Abstract of the Disclosure Unsaturated molding compositions containing an unsaturated polyester resin, a polymerizable monomer, an epihalohydrin polymer, and optionally, reinforcing fibers, catalyst, thermoplastic polymers, thickening agent and fillers.
The epihalohydrin polymer improves the toughness of the mold-ing composition.
The epihalohydrin polymer improves the toughness of the mold-ing composition.
Description
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" -- 1 UNSATURATED POLYESTER
MOLDING COMPOSIT~ONS
BACKGROUND OF THE INt~rI~N
Thermosetting unsaturated polyester resin based moldiny compounds are well known and consist of an unsaturated polyester resin, an ethylenically unsaturated copolymerizable monomer, inert mineral fillers, fibrous reinforcing fillers and a catalyst which initiates the cross~linking reaction 10 between the copolymerizable monomer and the unsaturated ; polyester resin at a chosen molding temperature. They are commonly used in many physical forms two of which are bulk molding co~x~nds (BMC~ and sheet molding co~x~nds (SMC). In bulk molding oo~x~nds, the fibrous reinforcing filler which is normally about 15 0.25 inch in length, is mechanically mixed with the unsatura-ted resin. In sheet molding compounds, the fibrous reinforc-ing filler which is normally about 0.5 to 2 inches in length, is present as chopped fibers deposited on a supporting carrier which are impregnated with the unsaturated resin system, 20 giving rise to sheets of molding compound in which the fibers have not been subjected to the degrading action of conventional molding compound mixers.
The use of unsaturated polyester resins in the mold-y ing of glass fiber reinforced or other fiber reinforced ;~i, 25 products enjoys broad application in the manufacture of auto--~ motive, industrial and home products.
Polyester molding compounds are described in U.S.
Patents 3,940,350, 3,974,124, 3,227,665, 3,701,748, and - 3,948,716.
Unfortunately, polyester resins are inherently ~ brittle and whenever unsaturated polyester resins are used as a matrix, then the toughening of the matrix is important.
~, Normal industry practice is to add a flexibilizer to the resin composition which often results in a significant reduction in ~, 35 the mechanical properties. This reduction in mechanical properties is unacceptable for many product applications. It is desirable to toughen unsaturated polyester resin composi-tions without significant adverse effects on other important ,r properties such as cure rate, maturation and strength.
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To an unsaturated polyester molding compositiOn containing unsaturated polyester resin(s~ and polymerizable monomer(s) is added from about 1 to about 30 parts by weight of an epihalohydrin polymer per 100 parts by ~eight of the 5 combined weight of the polyester resin and the polymerizable monomer. The composition containing the epihalohydrin polymer is greatly improved for toughness without significant adverse effects on strength and processing characteristics such as cure rate and maturation. The invention also includes 10 the molded composition in cured form, and shaped articles.
Polyesters useful in this invention are well known in the art and include those derived by condensation of unsat-urated dibasic acids or anhydrides containing 4 to 9 carbon atoms with polyols including dihydroxy and trihydroxy com-15 pounds containing 2 to 12 carbon atoms. The polyester may include the polymeric chain varying proportions of other saturated or aromatic dibasic acids and anhydrides which are not subject to cross-linking. The particular noncrosslinking moieties and their proportions will depend upon the desired 20 properties of the final product. Maleic, chloromaleic and fumaric acid may be mentioned as exemplary of noncross-linking moieties within the copolymer include: phthalic anhydride, endomethylene-tetrahydrophthalic acid, tetra-chlorophthalic acid, hexachloroendomethylenetetrahydrophthalic
" -- 1 UNSATURATED POLYESTER
MOLDING COMPOSIT~ONS
BACKGROUND OF THE INt~rI~N
Thermosetting unsaturated polyester resin based moldiny compounds are well known and consist of an unsaturated polyester resin, an ethylenically unsaturated copolymerizable monomer, inert mineral fillers, fibrous reinforcing fillers and a catalyst which initiates the cross~linking reaction 10 between the copolymerizable monomer and the unsaturated ; polyester resin at a chosen molding temperature. They are commonly used in many physical forms two of which are bulk molding co~x~nds (BMC~ and sheet molding co~x~nds (SMC). In bulk molding oo~x~nds, the fibrous reinforcing filler which is normally about 15 0.25 inch in length, is mechanically mixed with the unsatura-ted resin. In sheet molding compounds, the fibrous reinforc-ing filler which is normally about 0.5 to 2 inches in length, is present as chopped fibers deposited on a supporting carrier which are impregnated with the unsaturated resin system, 20 giving rise to sheets of molding compound in which the fibers have not been subjected to the degrading action of conventional molding compound mixers.
The use of unsaturated polyester resins in the mold-y ing of glass fiber reinforced or other fiber reinforced ;~i, 25 products enjoys broad application in the manufacture of auto--~ motive, industrial and home products.
Polyester molding compounds are described in U.S.
Patents 3,940,350, 3,974,124, 3,227,665, 3,701,748, and - 3,948,716.
Unfortunately, polyester resins are inherently ~ brittle and whenever unsaturated polyester resins are used as a matrix, then the toughening of the matrix is important.
~, Normal industry practice is to add a flexibilizer to the resin composition which often results in a significant reduction in ~, 35 the mechanical properties. This reduction in mechanical properties is unacceptable for many product applications. It is desirable to toughen unsaturated polyester resin composi-tions without significant adverse effects on other important ,r properties such as cure rate, maturation and strength.
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- - 2 1031~4~
To an unsaturated polyester molding compositiOn containing unsaturated polyester resin(s~ and polymerizable monomer(s) is added from about 1 to about 30 parts by weight of an epihalohydrin polymer per 100 parts by ~eight of the 5 combined weight of the polyester resin and the polymerizable monomer. The composition containing the epihalohydrin polymer is greatly improved for toughness without significant adverse effects on strength and processing characteristics such as cure rate and maturation. The invention also includes 10 the molded composition in cured form, and shaped articles.
Polyesters useful in this invention are well known in the art and include those derived by condensation of unsat-urated dibasic acids or anhydrides containing 4 to 9 carbon atoms with polyols including dihydroxy and trihydroxy com-15 pounds containing 2 to 12 carbon atoms. The polyester may include the polymeric chain varying proportions of other saturated or aromatic dibasic acids and anhydrides which are not subject to cross-linking. The particular noncrosslinking moieties and their proportions will depend upon the desired 20 properties of the final product. Maleic, chloromaleic and fumaric acid may be mentioned as exemplary of noncross-linking moieties within the copolymer include: phthalic anhydride, endomethylene-tetrahydrophthalic acid, tetra-chlorophthalic acid, hexachloroendomethylenetetrahydrophthalic
2~ acid, adipic acid, sebacic acid, succinic acid, and the like.
Any of a variety of well known polyols including di- and tri- hydroxy compounds containing 4 to 9 carbon atoms, preferably 4 to 6 carbon atoms can be used for condensation with the diacids to produce polyesters suitable for use in r 30 this invention. Preferred compounds, which are mentioned by way of example, of the large number of applicable compounds ` include: ethylene glycol, diethylene glycol, propylene glycol, polypropylene glycol, glycerol, 1,2-, 1,3-, and 1,4-butadienols, trimethylol propane, and the like. The method 35 by which the unsaturated polyester resins are made is not critical to this invention.
The polyester resin is dissolved in a solvent com-prising at least one polymerizable monomer which is copoly-., , ~
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merizable with the dissolved polyester~ The polymerizable monomer not only acts as a solvent but al50 copol~merizes with the unsaturated groups along the polyester chain.
Polymerizable monomers w~ich can be used in this invention 5 include polymerizable vinylidene compounds having at least one terminal CH2 ~group and containing 2 to 12 carbon atoms, preferably 3 to 10 carbon atoms. A wide variety of these compounds are known including both aliphatic and aromatic unsaturated hydrocarbons and hydrocarbon derivatives, such 10 as esters, acids and nitriles. Examples of suitable poly-merizable monomers are styrene, methyl styrene~ acrylonitrile, methyl acrylate, methyl methacrylate, vinyl acetate, allyl esters of phthalic, adipic, maleic, malonic, andcyanuric acids. Styrene and methyl styrene are particularly useful 15 polymerizable monomers. Commercial unsaturated polyester resins are normally sold as a li~uid solution with the un-~ saturated polyester resin dissolved in the polymerizable ; monomer.
Epihalohydrin polymers used as touyhners in this 20 invention can be an epihalohydrin homopolymer, a copolymer of two or m~re epihalohydrin monomers, or a copolymer of an epi-¦ halohydrin monomer(s) with an oxide monomer(s~.
The epihalohydrin monomers have the formula CH - CH - CH - X
\0/
where X is Cl, Br, I, or F. More preferredly, X is selected from Cl and Br. From a cost and availability standpoint, the preferred monomer is epichlorohydrin. Other halogen-bearing ~ 30 epoxide monomers can be used in partial replacement of the i epihalohydrin monomer(s). Examples of these monomers are 4-chloro-1,2-epoxy butane; 4-bromo-1, 2-epoxy butane; 1-¦ (1,3-dichloroisopropoxy)-2,3,-epoxypropane; 4,4,4-trichloro~l, 1 2-epoxy butane; l-bromoethyl glycidyl ether; l,l,l-trichloro-¦ 35 ethyl glycidyl ether; l,l,l-trifluoroethyl glycidyl ether;
1,2-epoxy-2-methyl-4,6,6,6-tetrachlorohexane; 1,2-epoxy-4-oxo-8,8,8-trichlorooctane; and the like ... ...
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The oxide monomers contain a c~clic oxy ( O ~
/ ~ .
ring therein. Examples of these monomers are alk~lene oxides such as ethylene oxide, propylene oxide, but~lene oxide, iso~
5 butylene oxide, octylene oxide, and the like~ cycloaliphatic oxides such as cyclohexene oxide, vinyl cyclohexene oxide, and . the like; glycidyl ethers such as meth~l glycidyl ether~ ethyl glycidyl ether, isopropyl glycidyl ether, n-hexyl glyci.dyl ether, phenyl glycidyl ether and the like; glycidyl acrylate 10 and glycidyl methacrylate; allyl glycidyl ether; styrene oxide;
:~ and 4- and 5- membered oxy ring compounds such as Puran and methyl substituted ~uran, and the like. Of the oxide monomers, the alkylene oxides containing two to about ei.ght carbon atoms are preferred.
Examples of more preferred epihalohydrin polymers are polyepichlorohydrin, polyepibromoh.ydrin, epi.chlorohydrin~
epibromohydrin copolymer, epichlorohydrin-ethylene oxide copolymer, epibromohydrinethylene ox~de copolymer, epichloro-hydrin-propylene oxide copolymer, and epi.chlorohydrin-ethylene : 20 oxidepropylene oxide terpolymer. Excellent results have been obtained with a homopolymer of epichlorohydrin~
Copolymers of epihalohydrin monomers and oxide monomers comprise at least 50% to 100~ by weîgh* (i.e., homo-.polymers) of polymerized units of epihalohydrin monomer(s), 25 and up to 50~ by weight of polymerized units of an oxide ,~ monomer(s). Preferably, the polymers contain from about 65 to 100% by weight of polymerized epihalohydrin monomer(s).
Epihalohydrin polymers suitable for use as toughen-ers for unsaturated polyester resins are of low molecular : 30 weight and will vary in form from fluid liquids to thick semisolids. The number average molecular weight ~Mn) of such polymers normally will vary from about 800 to about 50,000, preferably from about 2000 to about 15,000. The molecular weight is normally specified in terms of "Reduced Solution 35 Viscosity" or "RSV" which is a point value viscosity deter-mined as the viscosity at 25C of a solution of 0.4 gram of - --polymer dissolved in lO0 ml. of climethyl formamide containing .
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Any of a variety of well known polyols including di- and tri- hydroxy compounds containing 4 to 9 carbon atoms, preferably 4 to 6 carbon atoms can be used for condensation with the diacids to produce polyesters suitable for use in r 30 this invention. Preferred compounds, which are mentioned by way of example, of the large number of applicable compounds ` include: ethylene glycol, diethylene glycol, propylene glycol, polypropylene glycol, glycerol, 1,2-, 1,3-, and 1,4-butadienols, trimethylol propane, and the like. The method 35 by which the unsaturated polyester resins are made is not critical to this invention.
The polyester resin is dissolved in a solvent com-prising at least one polymerizable monomer which is copoly-., , ~
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merizable with the dissolved polyester~ The polymerizable monomer not only acts as a solvent but al50 copol~merizes with the unsaturated groups along the polyester chain.
Polymerizable monomers w~ich can be used in this invention 5 include polymerizable vinylidene compounds having at least one terminal CH2 ~group and containing 2 to 12 carbon atoms, preferably 3 to 10 carbon atoms. A wide variety of these compounds are known including both aliphatic and aromatic unsaturated hydrocarbons and hydrocarbon derivatives, such 10 as esters, acids and nitriles. Examples of suitable poly-merizable monomers are styrene, methyl styrene~ acrylonitrile, methyl acrylate, methyl methacrylate, vinyl acetate, allyl esters of phthalic, adipic, maleic, malonic, andcyanuric acids. Styrene and methyl styrene are particularly useful 15 polymerizable monomers. Commercial unsaturated polyester resins are normally sold as a li~uid solution with the un-~ saturated polyester resin dissolved in the polymerizable ; monomer.
Epihalohydrin polymers used as touyhners in this 20 invention can be an epihalohydrin homopolymer, a copolymer of two or m~re epihalohydrin monomers, or a copolymer of an epi-¦ halohydrin monomer(s) with an oxide monomer(s~.
The epihalohydrin monomers have the formula CH - CH - CH - X
\0/
where X is Cl, Br, I, or F. More preferredly, X is selected from Cl and Br. From a cost and availability standpoint, the preferred monomer is epichlorohydrin. Other halogen-bearing ~ 30 epoxide monomers can be used in partial replacement of the i epihalohydrin monomer(s). Examples of these monomers are 4-chloro-1,2-epoxy butane; 4-bromo-1, 2-epoxy butane; 1-¦ (1,3-dichloroisopropoxy)-2,3,-epoxypropane; 4,4,4-trichloro~l, 1 2-epoxy butane; l-bromoethyl glycidyl ether; l,l,l-trichloro-¦ 35 ethyl glycidyl ether; l,l,l-trifluoroethyl glycidyl ether;
1,2-epoxy-2-methyl-4,6,6,6-tetrachlorohexane; 1,2-epoxy-4-oxo-8,8,8-trichlorooctane; and the like ... ...
'~. .
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109184~
The oxide monomers contain a c~clic oxy ( O ~
/ ~ .
ring therein. Examples of these monomers are alk~lene oxides such as ethylene oxide, propylene oxide, but~lene oxide, iso~
5 butylene oxide, octylene oxide, and the like~ cycloaliphatic oxides such as cyclohexene oxide, vinyl cyclohexene oxide, and . the like; glycidyl ethers such as meth~l glycidyl ether~ ethyl glycidyl ether, isopropyl glycidyl ether, n-hexyl glyci.dyl ether, phenyl glycidyl ether and the like; glycidyl acrylate 10 and glycidyl methacrylate; allyl glycidyl ether; styrene oxide;
:~ and 4- and 5- membered oxy ring compounds such as Puran and methyl substituted ~uran, and the like. Of the oxide monomers, the alkylene oxides containing two to about ei.ght carbon atoms are preferred.
Examples of more preferred epihalohydrin polymers are polyepichlorohydrin, polyepibromoh.ydrin, epi.chlorohydrin~
epibromohydrin copolymer, epichlorohydrin-ethylene oxide copolymer, epibromohydrinethylene ox~de copolymer, epichloro-hydrin-propylene oxide copolymer, and epi.chlorohydrin-ethylene : 20 oxidepropylene oxide terpolymer. Excellent results have been obtained with a homopolymer of epichlorohydrin~
Copolymers of epihalohydrin monomers and oxide monomers comprise at least 50% to 100~ by weîgh* (i.e., homo-.polymers) of polymerized units of epihalohydrin monomer(s), 25 and up to 50~ by weight of polymerized units of an oxide ,~ monomer(s). Preferably, the polymers contain from about 65 to 100% by weight of polymerized epihalohydrin monomer(s).
Epihalohydrin polymers suitable for use as toughen-ers for unsaturated polyester resins are of low molecular : 30 weight and will vary in form from fluid liquids to thick semisolids. The number average molecular weight ~Mn) of such polymers normally will vary from about 800 to about 50,000, preferably from about 2000 to about 15,000. The molecular weight is normally specified in terms of "Reduced Solution 35 Viscosity" or "RSV" which is a point value viscosity deter-mined as the viscosity at 25C of a solution of 0.4 gram of - --polymer dissolved in lO0 ml. of climethyl formamide containing .
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3~ by volume of acetylacetone ~expressed as deciliter per gram or dl /g.l. The range of RSV corresponding to the number avexage molecular weight range given above will be from about 0.025 to about 0.5, preferably from about 0 075 5 to about 0.3. The epihalohydrin polymers have a bulk vis-cosity of from about 500 cps. to about 50,000,000 cps (measured at 27C using a Brookfield Viscometer~. To facili-tate handling the bulk viscosity of the epihalohydrin polymer can be reduced by blending the polymer with the dîssolving lQ polymerizable monomer. This may be desirable for high vis-cosity polymers. Li~uid epichlorohydrin polymers were found to be excellent tougheners for unsaturated polyester resins.
Epihalohydrin polymers suitable for use in this invention can be prepared according to U.S. Patent 3,850,856 15 and U.S. Patent 3,850,857.
The level of epihalohydrin polymer~s~ used is from about 1 to about 30 parts by weight, preferably from about 1 to about 15 parts ~y weight, said weight parts being based on 20 100 parts by weight of the polyester resin and the polymeriz-able monomer.
In addition to the polyester resin, the polymeriz-able monomer and the epihalohydrin polymer, the molding com-positions of this invention may include other ingredients 25 such as fillers, mold lubricants, catalysts, thickening agents, low profile additives, reinforcing fibers, flame and smoke retardants, and coloring agents.
As regards the filler materials suitable for use in the compositions of this invention, these may include con-30 ventional inorganic fillers such as carbonates, sulfates,phosphates, silica, silicate, micromica, carborundum, asbes-tos, glass, sandstone, graphite and the like reduced to a fine powder, as well as organic materials such as polyolefins, ` polyvinyl chloride, carbon black and acetylene black, poly-35 acrylate, polymethacrylates, solid polyesters, phenol-formal-dehyde resins, urea-formaldehyde resins, polyformol resins, polyamid resins, used in powder of appropriate granulometric compositon ranging from very fine powder to granular size.
The particles may sometimes fuse during the final cross-lO!~i~4Z
linking process.
Organic or inorganic bubbles may be used as fillersto reduce the weight of the unsaturated polyester compositions.
Hollow glass bubbles are particularly desirable as a weight 5 reducing filler. The glass bubbles have a nominal density less than 0.7 and preferably less than 0.5 gram per cubic centimeters. They are of small particle size of from about 1 to about 500 microns and preferably less than 150 microns.
-~ As reinforcing fibers, there may be used inorganic 10 fibers such as glass fibers, asbestos fibers; vegetable fibers such as flax, hemp, cotton, and the like; and organic fibers such as nylon, polyester, aromatic polyamide and the like. The reinforcing fibers may be present as chopped fibers having lengths of from about 0.1 to about 3 inches or 15 as woven mats, non-woven mats and the like. Sheet molding compounds will normally have chopped fibers of from about 0.5 to about 2 inches. The quantity of reinforcing fibers used will normally be from about 5 to 70 percent, preferably from 15 to 50 percent of fibers of the total weight of the 20 composition.
Mold lubricants which may be employed in the prep-. .
aration of the compositions of this invention include moldlubricants well known in the art and the choice is not critical. There may be mentioned, by way of example, zinc 25 stearate, calcium or magnesium stearate or oleate and zinc oleate. In some instances, the mold lubricant may be omitted as where organic fillers having the property of being self-lubricating, such as polyolefins, polyvinylchloride and the like are employed.
3Q Known chemical thickeners are the oxides and hyd-roxides of the metals of main group 2 of the periodic system, preferably the oxides and hydroxides of magnesium and cal-cium, to which small amounts of water are added optionally.
Magnesium oxide was found to be an especially desirable 35 thickener. The thickeners are normally used at levels of from about 1 to about 3 parts by weight per 100 parts of the combined weight of polyester resin and polymerizable monomer.
Examples of suitable catalysts are benzoyl peroxide, ~ tertiary butyl peroxide, cyclohexanone peroxide, tertiary ,., ., :: . . . . :
., , . ~ .
::
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butyl peroctoate, tertiary butyl perbenzoate, azo~obut~ro~
dinitrile, cumene hydroperoxide and the like The catalysts are normally used at levels of from about 0.5 to about 3 parts by weight per 100 parts of the combined weight of 5 polyester resin and polymerizable monomer.
Many applications for which unsaturated polyester compositions are used are not critical with respect to surface smoothness, but in certain uses such as automobile surface parts, for example, the characteristic rough surface 10 is objectionable. Often it is desirable to paint moldings used in automotive applications, for example, to achieve a smooth, metal-like, high-gloss appearance. To achieve a smooth surface, it is customary to use a low shrink additive, which is commonly referred to as a low-profile additive.
15 Low-profile additives are widely used in sheet molding compounds.
Low-profile additives which may be used in the unsaturated polyester resin compositions of this invention are well known in the art. The~ include thermoplastic homo~
20 polymers of vinylidene monomers containing 2 to 12 carbon atoms. Examples are homopolymers of alkyl acrylates and methacrylates such as methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate and the like; vinyl esters such as vinyl acetate and the like;
25 vinyl halides such as vinyl chloride and the like; vinyl aromatics such as styrene and the like. Thermoplastic co-polymers are also suitable for use as a low-profile additive such as copolymers of methyl methacrylate and lower alkyl ; esters of acrylic and methacrylic acids, and copolymers of 30 methyl methacrylate with minor amounts of one or more of the following: lauroyl methacrylate, isobornyl methacrylate, acrylamide, hydroxyethyl methacrylate, styrene, 2-ethylhexyl - acrylate, acrylonitrile, methacrylic acid, methacrylamide, methylol acrylamide and cetyl stearyl methacrylate. Copoly-35 mers of vinyl halides and vinyl esters are also useful as low-profile additives such as vinyl chloride/vinyl acetate copolymers and the like. Other useful examples of low-profile additive~ are styrene/acrylonitrile copolymers, - cellulose acetate butyrate, and cellulose acetate propionate.
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Excellent results were obtained using polyvinyl acetate.
Low-profile additives are normally supplied in a solution with a polymerizable monomer such as styrene.
After cure, the low-profile additive exists as fine particles 5 dispersed in the polyester matrix. Low-profile additives may be used at a level of from about 5 to about 40 parts by weight based on 100 parts by weight of the combined weight of the unsaturated polyester resin and the polymerizable monomer.
To prepare the novel molding compositions of this invention, normal procedures for preparing unsaturated poly-ester molding compositions are used except that the epihalo-hydrin liquid polymer is mixed with the polyester resin and polymerizable monomer. The remainder of the preparation 15 procedure will vary somewhat depending on the type of molding composition desired, such as sheet molding, bulk molding, ?
hand lay-up, spray-up, vacuum bag molding, injection molding, casting and the like.
For sheet molding compounds a typical preparation -20 procedure is to first mix the liquid ingredients together, that is the unsaturated polyester resin, polymerizable monomer, low-profile additive and the epihalohydrin polymer~
The epihalohydrin polymer may be added as is or mixed with the polymerizable monomer to reduce its viscosity and facili-25 tate handling. The liquid ingredients are then mixed with the fillers and mold release agents for about 15 to 20 minutes in a mixer such as a Cowles mixer. The catalyst is then added to the mix and mixed for about 2 to 5 minutes. The thickening agent is then added and mixed for about 1 to 3 30 minutes. The resin composition is then spread onto non-adhering sheets such as polyethylene. Chopped glass fibers ` are then sprayed onto the sheets of resin compound and the sheets brought together to form a composite. The composite is passed through compression rollers to effect impregnation - 35 of the glass by the resin mix. The sheets of the composite are then allowed to thicken with time (maturation) for about ,1 to 3 days at about 32C. For sheet molding applications, the resin composition should thicken to a viscosity of from about 30 x 106 cps. to about 100 x 106 cps. Preferably from ;l ., , ' ' - . . , , , c ~ -..... ~ . . - , , .
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about 50 x 10 cps. to about 7Q x 10 Cp5~ ~efore molding under heat and pressure. The thickened sheets are then cut into the desired size and molded and cured at an elevated temperature.
Initial compatibility of the polymer with the pGlyester resin and polymerizable monomer is important to produce the desired morphology. Quite unexpectedly, it was found that when the epihalohydrin polymer is mixed with the polyester resin and the polymerizable monomer, the polymer 10 appears to dissolve and becomes compatible with the mix.
This phenomenon is unusual since other liquid polymers such as liquid acrylonitrile/butadiene polymer would not readily dissolve in the resin mix. When the rubber polymer is incom-patible with the resin mix, there can be no control of rubber 15 particle size beyond mixing conditions and speed of process~
ing. Therefore, the rubber domains are large (,greater than 10 microns). When the compatible epihalohydrin polymer is used as a toughener ~or polyester resins, the rubber domains , are very small (from submicron to 10 microns in æize~ which , 20 is desirable for toughness improvement. The unexpectedly small particles of epihalohydrin polymer in the polyester is believed to result from its compatibility and subsequent precipitation at the onset of resin gelation.
' Since the epihalohydrin is compatible with the 25 unsaturated polyester resin mix, the compositions of this , invention have excellent storage properties. When an incom-,~ patible polymer i5 used in the mix and the mix is not used within a short time after mixing, the polymer has a tendency ~' to separate from the mix. The epihalohydrin, polyester resin 30 and polymerizable monomer of this invention can be premi~ed '~ and stored for long periods of time before the cataly~t and :.;
,- thickening agent are added to the mix. This is a Yery desir~
~i able feature for unsaturated pol~ester molding compositions, ; In order to evaluate the compositions of this ,~ 35 invention for toughness and other properties, standard , industry tests may be used. ~STM tests can be used for ", conventional mechanical properties such as D~790 for flexure ~,i and D-638 for tension, both with nominal 6.35 mm thick samples.
;, Izod testing was aone on samples that were unnotched and . .~ .!
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impacted normal to the molding surface. Other tests were used to measure shrinkage in the mold and Barcol hardness.
Fracture toughness was evaluated by the Gardner dart impact test and by an acoustic emission test designed to measure 5 crack dev~lopment during bending. The Gardner impact and acoustic emission tests warrant more detailed description.
For the Gardner impact test, an instrument is used which comprises a base plate, a round-nosed steel rod impact weight, a slotted tube having inch-pound graduations 10 in which the rod is lifted and dropped, and a bracket to hold the tube in a vertical position. Impact resistance is determined by sujecting either side of a sample panel to an impact of up to 320 inch-pounds, depending upon the weight dropped. The sample panel is placed over a 12.7 mm hole in 15 the base plate; the steel rod weight is raised by lifting an attached pin until the pin coincides with the desired inch- -pounds graduation mark on the slotted tube, and then dropped.
The sample panel is examined for cracking or ailure after each impact. The test used a 1.59 mm radius dart on a 6.35 20 mm sample panel. A two-pound weight was dropped from various heights onto the rinq suPported sample. The resultant damage was determined b~ detecting cracking on the reverse side of the sample. The detection was made relatively easy by inking the reverse side and then wiping it clean~ the ink 25 clearly identified the local cracking from the impact. The dart weight multiplied by the drop height at the onset of ; detectable cracking determined the reported Gardner impact value in inch-pounds.
The acoustic emission test was devised to measure 30 cracking during a simple cantilever bending load. In it, a 3.18 mm thick sample, 38 mm wide and 127 mm long is mounted in a Tinius Olsen Stiffness Tester and bent by applying a weight of 22.7 kg. The sample bent until 70~ of the weight was applied to it. The load caused the sample to bend 35 through 6 - 7 of measured arc. A dynamic microphone was mounted in contact with the specimen at the point of maximum arc. A tape recorder was used to record the noise of crack development during the bending sequence. This record can be r played back for an audible comparison of different samples.
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At the same time, the tape output can be fed into an oscillo-scope for a visible record of the cracking noise. The oscilloscope trace can be photographed to record the test.
A numerical value for the acoustic emission test is deter-5 mined by counting the number of peaks from the oscilloscopetrace.
The novel compositions of this invention containing epihalohydrin may be used in any of the many unsaturated polyester molding applications, but for illustrative purposes, 10 the examples are directed to unsaturated polyester sheet molding.
The following examples illustrate the present invention more fully.
EXAMPLE I
15 This example is presented to show the improvement in toughness imparted to an unsaturated polyester sheet molding compound by the use of a liquid polyepichlorohydrin polymer. A compound containing no liquid rubber ~control) and a compound containing a liquid acrylonitrile/butadiene rubber 20 ~sample 2) are compared with the compound containing liquid polyepichlorohydrin (sample 1).
TABLE I
Sample Ingredient (Parts_b~y Weight) Control 1 2 Unsaturated Polyester Resinl 65 65 65 Low-profile additive 35 35 35 Calcium Carbonate3 126 126 126 Zinc Stearate 3.9 3.9 3.9 t-butyl Perbenzoate 1.18 1.18 1.18 MgG 0.9 0.8 0.8 Liquid Polyepichloro-hydrin4 - 4,0 Liquid Acrylonitrile/
butadiene 5 - - 4.0 ,. . . : : .
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An isophthalic unsaturated polyester resin in a 40% styrene solution supplied by PPG under the trade name of Selection 50271 2A low profile additive suppiied by Union Carbide consisting of 40~ polyvinylacetate in a 6Q%
styrene solution 3Mean particle size of 2.5 microns 4A polyepichlorohydrin prepared according to U.S. Patent 3,850,856 and ha~ing a number average molecular weight of about 6,000 5A liquid polymer containing 33~ acrylonitrile .
The compositions were prepared by mixing the poly-ester resin, low-profile additive (both of which were dissolved in a polymerizable monomer), calcium carbonate, 15 zinc stearate and liquid polymer (in samples 1 and 2 only).
The liquid ingredients ~polyester resin, low-profile additive and rubber) were first mixed together. The liquid ingredients were then mixed with the calcium carbonate and zinc stearate - in a Cowles mixer for 15 minutes and then the t-butyl perbenz-2a oate catalyst was added to the mix and mixing continued for three minutes. The MgO was then added and mixing continued for two minutes. The compositions were then spread onto sheets of polyethylene and chopped glass fibers (1-1/4 inch long) was sprayed onto the compositions. The sheets were 25 brought together to form a composite. The composite was - passed through compression rollers to effect impregnation of the glass fibers by the resin mix. The quantity of chopped glass fibers used was such that the final sheet molding - compositions were 21% glass. The compositions were then 30rolled up in the polyethylene and allowed to thicken for about 48 hours at 32C. The sheets were then cut into sample size and cured for three minutes at 150C. in a 50 ton press.
` Testing results are shown in Table II.
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~- -- Sample TEST , Control 1 2 % Shrink 0 0 0 Barcol Hardness 48 38 29 Gardner Impact (in.-lb) 6 10 6 Unnotched Izod (ft.- 4.997.43 5.91 lb/in.) Tensile Stres~ (psi) 8930 10470 ~095 Tensile Elongation % - 1.27 1.41 1.47 Tensile Mo~ulus (ps~ x 106) 1.72 1.34 1.45 Flexure Stress (psi) 15865 21300 20400 Flexure Strain ~in./in.) 0.016 0.022 0.018 Flexure Modulus (psi x 106) 1.62 1.49 1.73 Acoustlc Emls~ion (cracks) 29 4 19 The above test results show that the toughness is greatly improved in the composition containing epichloro-20 hydrin (sample 1) as is shown by the acoustic emission cracks, Gardner impact, and Izod impact test results. Other import-ant properties such as tensile stress and flexure stress are fA not adversely effected. Processing characteristics such as shrink, cure rate and maturation are not significantly 25 effected by the use of epichlorohydrin as a toughener. The significant improvements in ~ardner impact and acoustic emissions were not present in the sample containing the other liquid polymer (sample 2).
- EXAMPLE III
30 This example is presented to show the improvement in toughness imparted to a reduced weight unsaturated poly-ester sheet molding compound by the use of a liquid poly-epichlorohydrin polymer. The reduced weight compounds I contain hollow glass bubbles. The other ingredients used 35such as the polyester resin, low-profile additive, fillers and epichlorohydrin were the same as those used in Example I.
The compositions evaluated are shown in Table III.
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TABLE III
Sample ~ngredient 3 (Control) (Part by Weight) Un3~turated Polyester 65 65 Low-Pro~ile Additive 35 35 Calcium Carbonate 126 126 Zinc Stearate 4 4 Glas~ Bubbles6 7-5 7-5 t-butyl Perbenzoate 1.12 1.12 M~;O 1 . O 1 . O
Liquid Polyepichlorohydrin - 4 6Nominal density = 0.37, particlo ~ize = 9~ by vol. between 20 and 130 microns . .
The comp~iti~ns were prepared as in Example I
except that the glass bubbles were added as a filler along , with the calcium carbonate. Testing results are shown in . 20 T~ble IV.
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Sample TEST 3 (Control) 4 % Shrink 0 0 Barcol Hardn'ess 50 45 Gardner Impact (in.-lb) 8 12 ~nnotched Izod (ft-lb/in.) 8.21 8.22 Tensile Stress (psi) 10790 10250 Tensile Elongation % 1.57 1.45 i 30 Tensile Modulus (psi x 106) 1.55 1.43 ~ Flexure Stress (psi) 20100 20190 ,, Flexure Strain (in./in.) 0.021 0.023 Flexure Modulus (psi x 10~) 1.74 1.46 Acoustic Eml~ion (cracks) 40 '1 . .
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As in Example I, the liquid polyepichlorohydrin increased the toughness of the unsaturated polyester sheet molding compound without adversely effecting the other prop-erties. By using polyepichloro~ydrin, the acoustic emissions 5 was dramatically reduced (from 40 to 1) which is indicative of the high toughness imparted to sample 4 by the polyepichloro-: hydrin.
The unsaturated polyester molding compositions ofthis invention have many uses including automotive parts, 10 chairs, trays, and the like.
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Epihalohydrin polymers suitable for use in this invention can be prepared according to U.S. Patent 3,850,856 15 and U.S. Patent 3,850,857.
The level of epihalohydrin polymer~s~ used is from about 1 to about 30 parts by weight, preferably from about 1 to about 15 parts ~y weight, said weight parts being based on 20 100 parts by weight of the polyester resin and the polymeriz-able monomer.
In addition to the polyester resin, the polymeriz-able monomer and the epihalohydrin polymer, the molding com-positions of this invention may include other ingredients 25 such as fillers, mold lubricants, catalysts, thickening agents, low profile additives, reinforcing fibers, flame and smoke retardants, and coloring agents.
As regards the filler materials suitable for use in the compositions of this invention, these may include con-30 ventional inorganic fillers such as carbonates, sulfates,phosphates, silica, silicate, micromica, carborundum, asbes-tos, glass, sandstone, graphite and the like reduced to a fine powder, as well as organic materials such as polyolefins, ` polyvinyl chloride, carbon black and acetylene black, poly-35 acrylate, polymethacrylates, solid polyesters, phenol-formal-dehyde resins, urea-formaldehyde resins, polyformol resins, polyamid resins, used in powder of appropriate granulometric compositon ranging from very fine powder to granular size.
The particles may sometimes fuse during the final cross-lO!~i~4Z
linking process.
Organic or inorganic bubbles may be used as fillersto reduce the weight of the unsaturated polyester compositions.
Hollow glass bubbles are particularly desirable as a weight 5 reducing filler. The glass bubbles have a nominal density less than 0.7 and preferably less than 0.5 gram per cubic centimeters. They are of small particle size of from about 1 to about 500 microns and preferably less than 150 microns.
-~ As reinforcing fibers, there may be used inorganic 10 fibers such as glass fibers, asbestos fibers; vegetable fibers such as flax, hemp, cotton, and the like; and organic fibers such as nylon, polyester, aromatic polyamide and the like. The reinforcing fibers may be present as chopped fibers having lengths of from about 0.1 to about 3 inches or 15 as woven mats, non-woven mats and the like. Sheet molding compounds will normally have chopped fibers of from about 0.5 to about 2 inches. The quantity of reinforcing fibers used will normally be from about 5 to 70 percent, preferably from 15 to 50 percent of fibers of the total weight of the 20 composition.
Mold lubricants which may be employed in the prep-. .
aration of the compositions of this invention include moldlubricants well known in the art and the choice is not critical. There may be mentioned, by way of example, zinc 25 stearate, calcium or magnesium stearate or oleate and zinc oleate. In some instances, the mold lubricant may be omitted as where organic fillers having the property of being self-lubricating, such as polyolefins, polyvinylchloride and the like are employed.
3Q Known chemical thickeners are the oxides and hyd-roxides of the metals of main group 2 of the periodic system, preferably the oxides and hydroxides of magnesium and cal-cium, to which small amounts of water are added optionally.
Magnesium oxide was found to be an especially desirable 35 thickener. The thickeners are normally used at levels of from about 1 to about 3 parts by weight per 100 parts of the combined weight of polyester resin and polymerizable monomer.
Examples of suitable catalysts are benzoyl peroxide, ~ tertiary butyl peroxide, cyclohexanone peroxide, tertiary ,., ., :: . . . . :
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butyl peroctoate, tertiary butyl perbenzoate, azo~obut~ro~
dinitrile, cumene hydroperoxide and the like The catalysts are normally used at levels of from about 0.5 to about 3 parts by weight per 100 parts of the combined weight of 5 polyester resin and polymerizable monomer.
Many applications for which unsaturated polyester compositions are used are not critical with respect to surface smoothness, but in certain uses such as automobile surface parts, for example, the characteristic rough surface 10 is objectionable. Often it is desirable to paint moldings used in automotive applications, for example, to achieve a smooth, metal-like, high-gloss appearance. To achieve a smooth surface, it is customary to use a low shrink additive, which is commonly referred to as a low-profile additive.
15 Low-profile additives are widely used in sheet molding compounds.
Low-profile additives which may be used in the unsaturated polyester resin compositions of this invention are well known in the art. The~ include thermoplastic homo~
20 polymers of vinylidene monomers containing 2 to 12 carbon atoms. Examples are homopolymers of alkyl acrylates and methacrylates such as methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate and the like; vinyl esters such as vinyl acetate and the like;
25 vinyl halides such as vinyl chloride and the like; vinyl aromatics such as styrene and the like. Thermoplastic co-polymers are also suitable for use as a low-profile additive such as copolymers of methyl methacrylate and lower alkyl ; esters of acrylic and methacrylic acids, and copolymers of 30 methyl methacrylate with minor amounts of one or more of the following: lauroyl methacrylate, isobornyl methacrylate, acrylamide, hydroxyethyl methacrylate, styrene, 2-ethylhexyl - acrylate, acrylonitrile, methacrylic acid, methacrylamide, methylol acrylamide and cetyl stearyl methacrylate. Copoly-35 mers of vinyl halides and vinyl esters are also useful as low-profile additives such as vinyl chloride/vinyl acetate copolymers and the like. Other useful examples of low-profile additive~ are styrene/acrylonitrile copolymers, - cellulose acetate butyrate, and cellulose acetate propionate.
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Excellent results were obtained using polyvinyl acetate.
Low-profile additives are normally supplied in a solution with a polymerizable monomer such as styrene.
After cure, the low-profile additive exists as fine particles 5 dispersed in the polyester matrix. Low-profile additives may be used at a level of from about 5 to about 40 parts by weight based on 100 parts by weight of the combined weight of the unsaturated polyester resin and the polymerizable monomer.
To prepare the novel molding compositions of this invention, normal procedures for preparing unsaturated poly-ester molding compositions are used except that the epihalo-hydrin liquid polymer is mixed with the polyester resin and polymerizable monomer. The remainder of the preparation 15 procedure will vary somewhat depending on the type of molding composition desired, such as sheet molding, bulk molding, ?
hand lay-up, spray-up, vacuum bag molding, injection molding, casting and the like.
For sheet molding compounds a typical preparation -20 procedure is to first mix the liquid ingredients together, that is the unsaturated polyester resin, polymerizable monomer, low-profile additive and the epihalohydrin polymer~
The epihalohydrin polymer may be added as is or mixed with the polymerizable monomer to reduce its viscosity and facili-25 tate handling. The liquid ingredients are then mixed with the fillers and mold release agents for about 15 to 20 minutes in a mixer such as a Cowles mixer. The catalyst is then added to the mix and mixed for about 2 to 5 minutes. The thickening agent is then added and mixed for about 1 to 3 30 minutes. The resin composition is then spread onto non-adhering sheets such as polyethylene. Chopped glass fibers ` are then sprayed onto the sheets of resin compound and the sheets brought together to form a composite. The composite is passed through compression rollers to effect impregnation - 35 of the glass by the resin mix. The sheets of the composite are then allowed to thicken with time (maturation) for about ,1 to 3 days at about 32C. For sheet molding applications, the resin composition should thicken to a viscosity of from about 30 x 106 cps. to about 100 x 106 cps. Preferably from ;l ., , ' ' - . . , , , c ~ -..... ~ . . - , , .
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about 50 x 10 cps. to about 7Q x 10 Cp5~ ~efore molding under heat and pressure. The thickened sheets are then cut into the desired size and molded and cured at an elevated temperature.
Initial compatibility of the polymer with the pGlyester resin and polymerizable monomer is important to produce the desired morphology. Quite unexpectedly, it was found that when the epihalohydrin polymer is mixed with the polyester resin and the polymerizable monomer, the polymer 10 appears to dissolve and becomes compatible with the mix.
This phenomenon is unusual since other liquid polymers such as liquid acrylonitrile/butadiene polymer would not readily dissolve in the resin mix. When the rubber polymer is incom-patible with the resin mix, there can be no control of rubber 15 particle size beyond mixing conditions and speed of process~
ing. Therefore, the rubber domains are large (,greater than 10 microns). When the compatible epihalohydrin polymer is used as a toughener ~or polyester resins, the rubber domains , are very small (from submicron to 10 microns in æize~ which , 20 is desirable for toughness improvement. The unexpectedly small particles of epihalohydrin polymer in the polyester is believed to result from its compatibility and subsequent precipitation at the onset of resin gelation.
' Since the epihalohydrin is compatible with the 25 unsaturated polyester resin mix, the compositions of this , invention have excellent storage properties. When an incom-,~ patible polymer i5 used in the mix and the mix is not used within a short time after mixing, the polymer has a tendency ~' to separate from the mix. The epihalohydrin, polyester resin 30 and polymerizable monomer of this invention can be premi~ed '~ and stored for long periods of time before the cataly~t and :.;
,- thickening agent are added to the mix. This is a Yery desir~
~i able feature for unsaturated pol~ester molding compositions, ; In order to evaluate the compositions of this ,~ 35 invention for toughness and other properties, standard , industry tests may be used. ~STM tests can be used for ", conventional mechanical properties such as D~790 for flexure ~,i and D-638 for tension, both with nominal 6.35 mm thick samples.
;, Izod testing was aone on samples that were unnotched and . .~ .!
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impacted normal to the molding surface. Other tests were used to measure shrinkage in the mold and Barcol hardness.
Fracture toughness was evaluated by the Gardner dart impact test and by an acoustic emission test designed to measure 5 crack dev~lopment during bending. The Gardner impact and acoustic emission tests warrant more detailed description.
For the Gardner impact test, an instrument is used which comprises a base plate, a round-nosed steel rod impact weight, a slotted tube having inch-pound graduations 10 in which the rod is lifted and dropped, and a bracket to hold the tube in a vertical position. Impact resistance is determined by sujecting either side of a sample panel to an impact of up to 320 inch-pounds, depending upon the weight dropped. The sample panel is placed over a 12.7 mm hole in 15 the base plate; the steel rod weight is raised by lifting an attached pin until the pin coincides with the desired inch- -pounds graduation mark on the slotted tube, and then dropped.
The sample panel is examined for cracking or ailure after each impact. The test used a 1.59 mm radius dart on a 6.35 20 mm sample panel. A two-pound weight was dropped from various heights onto the rinq suPported sample. The resultant damage was determined b~ detecting cracking on the reverse side of the sample. The detection was made relatively easy by inking the reverse side and then wiping it clean~ the ink 25 clearly identified the local cracking from the impact. The dart weight multiplied by the drop height at the onset of ; detectable cracking determined the reported Gardner impact value in inch-pounds.
The acoustic emission test was devised to measure 30 cracking during a simple cantilever bending load. In it, a 3.18 mm thick sample, 38 mm wide and 127 mm long is mounted in a Tinius Olsen Stiffness Tester and bent by applying a weight of 22.7 kg. The sample bent until 70~ of the weight was applied to it. The load caused the sample to bend 35 through 6 - 7 of measured arc. A dynamic microphone was mounted in contact with the specimen at the point of maximum arc. A tape recorder was used to record the noise of crack development during the bending sequence. This record can be r played back for an audible comparison of different samples.
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At the same time, the tape output can be fed into an oscillo-scope for a visible record of the cracking noise. The oscilloscope trace can be photographed to record the test.
A numerical value for the acoustic emission test is deter-5 mined by counting the number of peaks from the oscilloscopetrace.
The novel compositions of this invention containing epihalohydrin may be used in any of the many unsaturated polyester molding applications, but for illustrative purposes, 10 the examples are directed to unsaturated polyester sheet molding.
The following examples illustrate the present invention more fully.
EXAMPLE I
15 This example is presented to show the improvement in toughness imparted to an unsaturated polyester sheet molding compound by the use of a liquid polyepichlorohydrin polymer. A compound containing no liquid rubber ~control) and a compound containing a liquid acrylonitrile/butadiene rubber 20 ~sample 2) are compared with the compound containing liquid polyepichlorohydrin (sample 1).
TABLE I
Sample Ingredient (Parts_b~y Weight) Control 1 2 Unsaturated Polyester Resinl 65 65 65 Low-profile additive 35 35 35 Calcium Carbonate3 126 126 126 Zinc Stearate 3.9 3.9 3.9 t-butyl Perbenzoate 1.18 1.18 1.18 MgG 0.9 0.8 0.8 Liquid Polyepichloro-hydrin4 - 4,0 Liquid Acrylonitrile/
butadiene 5 - - 4.0 ,. . . : : .
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~ 184Z
An isophthalic unsaturated polyester resin in a 40% styrene solution supplied by PPG under the trade name of Selection 50271 2A low profile additive suppiied by Union Carbide consisting of 40~ polyvinylacetate in a 6Q%
styrene solution 3Mean particle size of 2.5 microns 4A polyepichlorohydrin prepared according to U.S. Patent 3,850,856 and ha~ing a number average molecular weight of about 6,000 5A liquid polymer containing 33~ acrylonitrile .
The compositions were prepared by mixing the poly-ester resin, low-profile additive (both of which were dissolved in a polymerizable monomer), calcium carbonate, 15 zinc stearate and liquid polymer (in samples 1 and 2 only).
The liquid ingredients ~polyester resin, low-profile additive and rubber) were first mixed together. The liquid ingredients were then mixed with the calcium carbonate and zinc stearate - in a Cowles mixer for 15 minutes and then the t-butyl perbenz-2a oate catalyst was added to the mix and mixing continued for three minutes. The MgO was then added and mixing continued for two minutes. The compositions were then spread onto sheets of polyethylene and chopped glass fibers (1-1/4 inch long) was sprayed onto the compositions. The sheets were 25 brought together to form a composite. The composite was - passed through compression rollers to effect impregnation of the glass fibers by the resin mix. The quantity of chopped glass fibers used was such that the final sheet molding - compositions were 21% glass. The compositions were then 30rolled up in the polyethylene and allowed to thicken for about 48 hours at 32C. The sheets were then cut into sample size and cured for three minutes at 150C. in a 50 ton press.
` Testing results are shown in Table II.
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~- -- Sample TEST , Control 1 2 % Shrink 0 0 0 Barcol Hardness 48 38 29 Gardner Impact (in.-lb) 6 10 6 Unnotched Izod (ft.- 4.997.43 5.91 lb/in.) Tensile Stres~ (psi) 8930 10470 ~095 Tensile Elongation % - 1.27 1.41 1.47 Tensile Mo~ulus (ps~ x 106) 1.72 1.34 1.45 Flexure Stress (psi) 15865 21300 20400 Flexure Strain ~in./in.) 0.016 0.022 0.018 Flexure Modulus (psi x 106) 1.62 1.49 1.73 Acoustlc Emls~ion (cracks) 29 4 19 The above test results show that the toughness is greatly improved in the composition containing epichloro-20 hydrin (sample 1) as is shown by the acoustic emission cracks, Gardner impact, and Izod impact test results. Other import-ant properties such as tensile stress and flexure stress are fA not adversely effected. Processing characteristics such as shrink, cure rate and maturation are not significantly 25 effected by the use of epichlorohydrin as a toughener. The significant improvements in ~ardner impact and acoustic emissions were not present in the sample containing the other liquid polymer (sample 2).
- EXAMPLE III
30 This example is presented to show the improvement in toughness imparted to a reduced weight unsaturated poly-ester sheet molding compound by the use of a liquid poly-epichlorohydrin polymer. The reduced weight compounds I contain hollow glass bubbles. The other ingredients used 35such as the polyester resin, low-profile additive, fillers and epichlorohydrin were the same as those used in Example I.
The compositions evaluated are shown in Table III.
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TABLE III
Sample ~ngredient 3 (Control) (Part by Weight) Un3~turated Polyester 65 65 Low-Pro~ile Additive 35 35 Calcium Carbonate 126 126 Zinc Stearate 4 4 Glas~ Bubbles6 7-5 7-5 t-butyl Perbenzoate 1.12 1.12 M~;O 1 . O 1 . O
Liquid Polyepichlorohydrin - 4 6Nominal density = 0.37, particlo ~ize = 9~ by vol. between 20 and 130 microns . .
The comp~iti~ns were prepared as in Example I
except that the glass bubbles were added as a filler along , with the calcium carbonate. Testing results are shown in . 20 T~ble IV.
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Sample TEST 3 (Control) 4 % Shrink 0 0 Barcol Hardn'ess 50 45 Gardner Impact (in.-lb) 8 12 ~nnotched Izod (ft-lb/in.) 8.21 8.22 Tensile Stress (psi) 10790 10250 Tensile Elongation % 1.57 1.45 i 30 Tensile Modulus (psi x 106) 1.55 1.43 ~ Flexure Stress (psi) 20100 20190 ,, Flexure Strain (in./in.) 0.021 0.023 Flexure Modulus (psi x 10~) 1.74 1.46 Acoustic Eml~ion (cracks) 40 '1 . .
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As in Example I, the liquid polyepichlorohydrin increased the toughness of the unsaturated polyester sheet molding compound without adversely effecting the other prop-erties. By using polyepichloro~ydrin, the acoustic emissions 5 was dramatically reduced (from 40 to 1) which is indicative of the high toughness imparted to sample 4 by the polyepichloro-: hydrin.
The unsaturated polyester molding compositions ofthis invention have many uses including automotive parts, 10 chairs, trays, and the like.
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Claims (33)
1. An unsaturated polyester molding composition comprising:
(a) an unsaturated polyester resin, (b) a polymerizable monomer, (c) from about 1 to about 30 parts by weight of an epihalohydrin polymer per 100 parts by weight of the combined weight of said unsaturated polyester resin and polymerizable monomer.
(a) an unsaturated polyester resin, (b) a polymerizable monomer, (c) from about 1 to about 30 parts by weight of an epihalohydrin polymer per 100 parts by weight of the combined weight of said unsaturated polyester resin and polymerizable monomer.
2. A composition of Claim 1 wherein the epihalo-hydrin polymer has a number average molecular weight of from about 800 to about 50,000.
3. A composition of Claim 2 containing a catalytic amount of a catalyst selected from the group consisting of benzoyl peroxide, tertiary butyl perbenzoate, cyclohexanone peroxide, tertiary butyl peroxide, tertiary butyl peroctoate, azoisobutyrodinitrile, and cumene hydroperoxide.
4, A composition of Claim 3 containing fiber re-inforcement wherein said fibers are selected from the group consisting of glass, nylon, polyester, and aromatic polyamide.
5. A composition of Claim 4 wherein the level of said fibers is from about 5 percent to about 70 percent by weight of the total composition weight.
6. A composition of Claim 4 containing a thermo-plastic low-profile additive.
7. A composition of Claim 6 containing as a thick-ening agent an oxide or hydroxide of magnesium or calcium.
8. A composition of Claim 7 wherein the low-profile additive is a thermoplastic homopolymer of a vinylidene monomer containing from 2 to 12 carbon atoms.
9. A composition of Claim 7 wherein said composi-tion has a viscosity of from about 30,000,000 to about 100,000,000 cps.
10. A composition of Claim 8 wherein the level of epihalohydrin polymer is from about 1 to about 15 parts by weight per 100 parts by weight of the combined weight of said unsaturated polyester resin and polymerizable monomer.
11. A composition of claim 10 containing glass bubbles wherein said glass bubbles have a density of less than about 0.7 gram per cubic centimeter and a particle size less than about 500 microns.
12. A composition of Claim 11 wherein the epihalo-hydrin polymer is selected from the group consisting of a homopolymer of an epihalohydrin monomer and a copolymer of an epihalohydrin monomer and an oxide monomer containing a cyclic oxy ring.
13. A composition of Claim 12 wherein the epihalo-hydrin polymer is a homopolymer of epichlorohydrin.
14. A composition of Claim 13 wherein the fiber reinforcement is chopped glass fiber having a length of from about 0.1 to about 3 inches.
15. A composition of Claim 3 wherein the epihalo-hydrin polymer is selected from the group consisting of a homopolymer of an epihalohydrin monomer and an oxide monomer containing a cyclic oxy ring.
16. A composition of Claim 15 wherein the level of epihalohydrin polymer is from about 1 to about 15 parts by weight per 100 parts by weight of the combined weight of said unsaturated polyester resin and polymerizable monomer.
17. A composition of Claim 16 wherein the epihalo-hydrin polymer is a homopolymer of epichlorohydrin.
18. A molded cured composition of Claim 1.
19. A process for producing a moldable unsaturated polyester composition which comprises mixing at least one unsaturated polyester resin with at least one polymerizable monomer and from about 1 to about 30 parts by weight of epihalohydrin polymer per 100 parts by weight of the combined weight of said unsaturated polyester resin and said polymeri-zable monomer.
20, A process of Claim 19 wherein the epihalohydrin polymer has a number average molecular weight of from about 800 to about 50,000.
21. A process of Claim 20 with the added steps of (a) mixing a catalytic amount of a catalyst with the composition, (b) mixing reinforcing fibers with the composi-tion, and (c) mixing a thermoplastic low-profile additive with the composition.
22. A process of Claim 21 with the added step of mixing a thickening agent with the composition wherein said thickening agent is an oxide or hydroxide of magnesium or calcium.
23. A process of Claim 22 wherein the epihalohydrin polymer is selected from the group consisting of a homopoly-mer of an epihalohydrin monomer and a copolymer of an epihalo-hydrin monomer and an oxide monomer containing a cyclic oxy ring, and wherein the level of said epihalohydrin polymer is from about 1 to about 15 parts by weight per 100 parts by weight of the combined weight of said unsaturated polyester resin and polymerizable monomer.
24. A process of Claim 23 wherein the epihalohydrin polymer is a homopolymer of epichlorohydrin.
25. A shaped article comprising:
(a) an unsaturated polyester resin, (b) a polymerizable monomer, and (c) from about 1 to about 30 parts by weight of an epihalohydrin polymer per 100 parts by weight of the combined weight of said unsaturated polyester resin and polymeriz-able monomer.
(a) an unsaturated polyester resin, (b) a polymerizable monomer, and (c) from about 1 to about 30 parts by weight of an epihalohydrin polymer per 100 parts by weight of the combined weight of said unsaturated polyester resin and polymeriz-able monomer.
26. An article of Claim 25 wherein the epihalohydrin polymer has a number average molecular weight of from about 800 to about 50,000.
27. An article of Claim 26 containing fiber rein-forcement wherein said fibers are selected from the group consisting of glass, nylon, polyester and aromatic polyaminde.
28. An article of Claim 27 wherein the level of epihalohydrin polymer is from about 1 to about 15 parts by weight per 100 parts by weight of the combined weight of said unsaturated polyester resin and polymerizable monomer.
29. An article of Claim 28 containing a thermo-plastic low-profile additive.
30. An article of Claim 29 wherein the epihalohydrin polymer is selected from the group consisting of a homopolymer of an epihalohydrin monomer and a copolymer of an epihalohydrin monomer and an oxide monomer containing a cyclic oxy ring.
31. An article of Claim 30 wherein the epihalo-hydrin polymer is a homopolymer of epichlorohydrin.
32. An article of Claim 31 wherein the fiber rein-forcement is chopped glass fiber having a length of from about 0.1 to about 3 inches.
33. An article of Claim 32 containing glass bubbles wherein said glass bubbles have a density of less than about 0.7 gram per cubic centimeter and a particle size less than about 500 microns.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/816,230 US4101604A (en) | 1977-07-18 | 1977-07-18 | Unsaturated polyester molding compositions |
| US816,230 | 1977-07-18 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1091842A true CA1091842A (en) | 1980-12-16 |
Family
ID=25220025
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA306,571A Expired CA1091842A (en) | 1977-07-18 | 1978-06-29 | Unsaturated polyester molding compositions |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US4101604A (en) |
| EP (1) | EP0000527A1 (en) |
| JP (1) | JPS5421492A (en) |
| CA (1) | CA1091842A (en) |
| IT (1) | IT1097818B (en) |
Families Citing this family (27)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4221889A (en) * | 1979-06-04 | 1980-09-09 | The B. F. Goodrich Company | Divinyl polyester molding compositions |
| US4274994A (en) * | 1979-09-06 | 1981-06-23 | The B. F. Goodrich Company | Reactive terminally unsaturated liquid polymers in unsaturated polyesters |
| USRE31577E (en) * | 1979-09-06 | 1984-05-01 | The B. F. Goodrich Company | Reactive terminally unsaturated liquid polymers in unsaturated polyesters |
| US4529757A (en) * | 1980-05-16 | 1985-07-16 | The Budd Company | Thermosetting resin patching compound |
| US4525498A (en) * | 1980-10-16 | 1985-06-25 | Union Carbide Corporation | Polyester fiber reinforced molding compounds |
| US4370428A (en) * | 1980-10-17 | 1983-01-25 | Danville Carlos R | Pigmented peroxide and polyester compositions |
| CA1175593A (en) * | 1981-02-24 | 1984-10-02 | Union Carbide Corporation | Low profile surface polyester moldings |
| US4584330A (en) * | 1984-02-03 | 1986-04-22 | J. M. Huber Corporation | Synthetic alkali metal aluminum silicates as pigment/colorant extenders and property enhancers in plastics |
| US4622354A (en) * | 1985-10-22 | 1986-11-11 | The Budd Company | Phase stabilized polyester molding material |
| FR2589473B1 (en) * | 1985-10-30 | 1988-09-16 | Saint Gobain Vetrotex | POLYMERIZABLE RESIN COMPOSITION REINFORCED BY CUT WIRES |
| US4755557A (en) * | 1986-06-19 | 1988-07-05 | Union Carbide Corporation | Fiber reinforced molding compositions providing improved surface characteristics |
| US4822439A (en) * | 1987-08-24 | 1989-04-18 | Owens-Corning Fiberglas Corporation | Process for forming thick ballistic resistant materials |
| US4929651A (en) * | 1987-08-24 | 1990-05-29 | Owens-Corning Fiberglas Corporation | Process for forming thick ballistic resistant materials |
| WO1989003407A1 (en) * | 1987-10-16 | 1989-04-20 | The Swan Corporation | Composition of matter for wear surfaces and method for producing same |
| US5202366A (en) * | 1988-07-20 | 1993-04-13 | Union Carbide Chemicals & Plastics Technology Corporation | Crosslinkable polyester compositions with improved properties |
| US5006293A (en) * | 1989-02-02 | 1991-04-09 | Owens-Corning Fiberglas Corporation | Process for forming flat plate ballistic resistant materials |
| ATE120771T1 (en) * | 1989-03-31 | 1995-04-15 | Union Carbide Chem Plastic | POLYVINYL ETHER AS A SHRINKAGE CONTROL AGENT. |
| DE4112668A1 (en) * | 1991-04-18 | 1992-10-22 | Huels Chemische Werke Ag | THERMOPLASTIC MULTILAYER COMPOSITION |
| US5256709A (en) * | 1991-07-22 | 1993-10-26 | Owens-Corning Fiberglas Technology, Inc. | Unsaturated polyester resin compositions containing compatible compounds having aromatic substituents |
| US5256708A (en) * | 1991-07-22 | 1993-10-26 | Owens-Corning Fiberglas Technology, Inc. | Unsaturated polyester resin compositions containing compatible compounds having sulfur-containing substituents |
| EP0552789B1 (en) * | 1992-01-24 | 1996-05-08 | Takeda Chemical Industries, Ltd. | Unsaturated polyester resin compositions, molding materials, and molded products |
| AU1519099A (en) * | 1997-11-04 | 1999-05-24 | Composite Technology Group, Llc | Nonstyrenated polyester and vinylester resins |
| KR100439809B1 (en) * | 2001-05-23 | 2004-07-12 | 현대자동차주식회사 | Methods for preparing low specific gravity thermosetting composite |
| US10000670B2 (en) | 2012-07-30 | 2018-06-19 | Henkel IP & Holding GmbH | Silver sintering compositions with fluxing or reducing agents for metal adhesion |
| TWI651387B (en) | 2013-09-30 | 2019-02-21 | 漢高智慧財產控股公司 | Conductive die attach film for large die semiconductor packages and compositions useful for the preparation thereof |
| CN107709418B (en) | 2015-05-08 | 2021-04-27 | 汉高知识产权控股有限责任公司 | Sinterable films and pastes and methods of use thereof |
| KR20200139293A (en) * | 2019-06-03 | 2020-12-14 | 현대자동차주식회사 | A thermosetting composite resin composition excellent in surface smoothness and mechanical properties, and a method for manufacturing an automobile shell plate using the same |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3327019A (en) * | 1960-11-24 | 1967-06-20 | Bayer Ag | Diethers and copolymerizates therefrom |
| US3225115A (en) * | 1960-12-28 | 1965-12-21 | Union Carbide Corp | Curable compositions containing epoxy alcohol, unsaturated polycarboxylic acid and unsaturated monomer |
| US3445544A (en) * | 1966-12-20 | 1969-05-20 | American Cyanamid Co | Rubber-reinforced acrylate resin containing polymeric epichlorohydrin |
| US3644568A (en) * | 1968-10-31 | 1972-02-22 | Anchor Chemical Co Ltd The | Polyester compositions |
| US3725461A (en) * | 1970-04-13 | 1973-04-03 | Celanese Corp | Terephthalic based unsaturated polyesters |
| US3740372A (en) * | 1970-04-15 | 1973-06-19 | Koppers Co Inc | Chemically thickened polyester resin |
| GB1387583A (en) | 1971-05-21 | 1975-03-19 | Dunlop Ltd | Composite structures |
| US3814718A (en) * | 1971-11-18 | 1974-06-04 | Albert Ag Chem Werke | Thermosetting moulding compositions |
| US3926902A (en) * | 1971-12-09 | 1975-12-16 | Dart Ind Inc | Crosslinkable thermoplastic compositions and processes therefor |
| JPS5430412B2 (en) * | 1974-03-19 | 1979-10-01 |
-
1977
- 1977-07-18 US US05/816,230 patent/US4101604A/en not_active Expired - Lifetime
-
1978
- 1978-06-29 CA CA306,571A patent/CA1091842A/en not_active Expired
- 1978-07-14 IT IT25707/78A patent/IT1097818B/en active
- 1978-07-17 EP EP78100411A patent/EP0000527A1/en not_active Withdrawn
- 1978-07-18 JP JP8685978A patent/JPS5421492A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6245247B2 (en) | 1987-09-25 |
| IT1097818B (en) | 1985-08-31 |
| JPS5421492A (en) | 1979-02-17 |
| IT7825707A0 (en) | 1978-07-14 |
| EP0000527A1 (en) | 1979-02-07 |
| US4101604A (en) | 1978-07-18 |
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