EP0559888A1 - Compositions en plastique polyester thermodurcissables contenant un polyisocyanate bloque et une substance reactive a l'isocyanate - Google Patents

Compositions en plastique polyester thermodurcissables contenant un polyisocyanate bloque et une substance reactive a l'isocyanate

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Publication number
EP0559888A1
EP0559888A1 EP19920923160 EP92923160A EP0559888A1 EP 0559888 A1 EP0559888 A1 EP 0559888A1 EP 19920923160 EP19920923160 EP 19920923160 EP 92923160 A EP92923160 A EP 92923160A EP 0559888 A1 EP0559888 A1 EP 0559888A1
Authority
EP
European Patent Office
Prior art keywords
diisocyanate
isocyanate
polyester resin
unsaturated polyester
blocked
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.)
Withdrawn
Application number
EP19920923160
Other languages
German (de)
English (en)
Inventor
Kenneth Earl Atkins
Gary C. Rex
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Union Carbide Chemicals and Plastics Technology LLC
Original Assignee
Union Carbide Chemicals and Plastics Technology LLC
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Union Carbide Chemicals and Plastics Technology LLC filed Critical Union Carbide Chemicals and Plastics Technology LLC
Publication of EP0559888A1 publication Critical patent/EP0559888A1/fr
Withdrawn legal-status Critical Current

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Classifications

    • 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
    • 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
    • C08G18/00—Polymeric products of isocyanates or isothiocyanates
    • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
    • C08G18/08—Processes
    • C08G18/10—Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step
    • 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
    • C08G18/00—Polymeric products of isocyanates or isothiocyanates
    • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
    • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
    • C08G18/67—Unsaturated compounds having active hydrogen
    • C08G18/68—Unsaturated polyesters
    • 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
    • C08G18/00—Polymeric products of isocyanates or isothiocyanates
    • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
    • C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
    • C08G18/72—Polyisocyanates or polyisothiocyanates
    • C08G18/80—Masked polyisocyanates
    • C08G18/8061—Masked polyisocyanates masked with compounds having only one group containing active hydrogen
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L31/00—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an acyloxy radical of a saturated carboxylic acid, of carbonic acid or of a haloformic acid; Compositions of derivatives of such polymers
    • C08L31/02—Homopolymers or copolymers of esters of monocarboxylic acids
    • C08L31/04—Homopolymers or copolymers of vinyl acetate
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L75/00—Compositions of polyureas or polyurethanes; Compositions of derivatives of such polymers
    • C08L75/04—Polyurethanes

Definitions

  • This application relates to reinforced thermosetting polyester compositions, and more particularly, to such compositions containing blocked polyisocyanates plus isocyanate-reactive material.
  • thermosetting polyester-based molding compositions in the form of sheet molding compound (SMC) and bulk molding compound (BMC) have been known for many years. These materials are based on unsaturated polyester resins produced from a reaction between a polyol having at least 2 hydroxyl groups, and a mixture of saturated and unsaturated dicarboxylic acids (or their
  • the initially formed unsaturated polyester resin is blended with one or more monomers capable of crosslinking with the unsaturated in the polyester, a peroxide catalyst, and a reinforcing material such as fiberglass, then heated to
  • earth-containing thickener such as magnesium oxide is added to the composition before crosslinking is initiated. This is thought to complex with residual carboxyl groups of the polyester molecules, thereby increasing the viscosity of the mixture and aiding achievement of uniform distribution of reinforcing filler as the mixture is caused to flow into its final shape during processing.
  • the molding is thought to complex with residual carboxyl groups of the polyester molecules, thereby increasing the viscosity of the mixture and aiding achievement of uniform distribution of reinforcing filler as the mixture is caused to flow into its final shape during processing.
  • compositions also frequently contain various other fillers, mold release agent, and other additives to be discussed below.
  • thermosetting polyester resins suffered from the difficulties that 1) the surfaces of molded parts were poor, and included fiber patterns which required costly sanding operations for painted applications and precluded use of such materials in high appearance internally pigmented applications; 2) parts could not be molded to close tolerances because of warpage; 3) molded parts contained
  • thermoplastic materials to the molding composite.
  • the presence of these thermoplastics in the molding composite The presence of these thermoplastics in the molding composite.
  • composition reduces shrinkage of the part during cure, or in some cases causes a small amount of expansion, thereby providing molded parts which more accurately reflect the molds in which they were made, and which have relatively smooth surfaces.
  • the surface smoothness of a molded part is gauged by measuring its surface profile by means of a suitable surface analyzer. A rough surface exhibits a high surface profile, while a smooth surface exhibits a low surface profile.
  • thermoplastics smoother surfaces in the molded part, relative to the case without such thermoplastic materials present, these thermoplastics are called "low profile additives".
  • thermoplastics have been found to give varying levels of shrinkage control.
  • thermoplastic low profile additive are selected on the basis of simple trials.
  • polyester resins those based on the condensation of 1.0 mole of maleic anhydride with a slight excess of propylene glycol, and similar resins in which up to 0.35 moles of the maleic anhydride is replaced with orthophthalic anhydride or isophthalic acid.
  • the comonomer is almost always styrene.
  • the first generation of low profile additives were materials such as polystyrene and polyethylene. Molded parts incorporating such additives were found to exhibit shrinkage of about 2 mils per inch (0.2%), in contrast to shrinkages of 4 to 5 mils per inch (0.4-0.5%) found for composites lacking these additives. The resulting composites were found to accept internal pigments well, but the surface quality of the parts was poor and the degree of shrinkage, although improved relative to that of composites containing no low profile additive, was still objectionably high for many applications.
  • the second generation of low profile additives were acrylic-based polymers such as polymethylmethacrylate, which when employed with specific unsaturated polyester resins prepared by condensation of maleic anhydride with propylene glycol, gave composite materials which exhibited shrinkage of about 0.5 mils per inch (0.05%). These materials were found to have poor pigmentability and poor surface smoothness by current standards.
  • the third generation of low profile additives were the poly(vinyl acetate) polymers.
  • Such additives can be used in a wide range of
  • compositions containing poly(vinyl acetate) low profile additives have poor pigmentability, but the molded parts have very good dimensional stability and surface smoothness. As a result, these
  • the fourth generation of low profile additives are materials which cause unsaturated polyester resin composite materials containing them to tend to expand slightly during cure, thereby reproducing the surface of the mold with great accuracy.
  • products made with these additives generally are 0.3 to 0.4 mils per inch larger than the room temperature dimensions of the mold.
  • the surface smoothness of parts made with these low profile additives equals or exceeds the smoothness of automotive grade steel.
  • shrinkage control synergists are a) epoxide-containing materials such as epoxidized octyl tallate, b) secondary monomers such as vinyl acetate monomer, which are more reactive with themselves than with styrene, c) mixtures of such epoxides and secondary monomers, d) lactones such as caprolactone, e) siloxane-alkylene oxide polymers, and f) fatty acid esters.
  • a standard low profile additive such as poly(vinyl acetate), preferably acid-containing, plus an isocyanate prepolymer resulting from
  • thermosetting polyester-based molding composition containing a low profile additive results in final molded parts having significantly enhanced strength, particularly flex strength, as well as well as excellent shrinkage control and superior surface smoothness, relative to parts made from such polyester-based molding compositions not containing these additives.
  • thermosetting molding composition of the invention comprises an unsaturated polyester, an olefinically unsaturated monomer, a thermoplastic low profile additive, a reinforcing filler, and further includes a blocked polyisocyanate, and an isocyanate-reactive material which is different from the unsaturated polyester employed in the
  • composition An example is a material which
  • a process for preparing a reinforced thermoset molded composite includes the steps of preparing the thermosetting molding composition of the invention, forming this composition into a desired shape, and heating the shaped composition to cure it.
  • Molded articles made using the composition and process of the invention are also aspects of the invention.
  • the unsaturated polyesters which are employed in the invention are materials which are well known to the art. Each is the reaction product of a polyol and at least one olefinically
  • unsaturated dicarboxylic acid or anhydride may also include residues of saturated and/or aromatic dicarboxylic acids or anhydrides.
  • the olefinic unsaturation is preferably in the ⁇ position
  • the unsaturated polyester typically has a molecular weight in the range of 1,000 to 2,000, and contains residual carboxyl and hydroxyl groups as well as olefinic unsaturation.
  • dicarboxcyclic acids and anhydrides useful in preparation of the polyesters are materials such as maleic acid or anhydride, fumaric acid,
  • chlorendic anhydride hexachloroendomethylene tetrahydrophthalic anhydride
  • itaconic acid citraconic acid
  • mesaconic acid mesaconic acid
  • Diels Alder adducts of maleic acid or anhydride with compounds having conjugated olefinic unsaturation such adducts being exemplified by bicyclo[2.2.1]hept-5-en3-2,3- dicarboxylic anhydride, methyl maleic acid, and itaconic acid.
  • Maleic acid or anhydride and fumaric acid are the most widely used commercially.
  • saturated or aromatic dicarboxycyclic acids or anhydrides which may be used in the preparation of the polyesters are materials such as phthalic acid or anhydride, terephthalic acid, tetrahydrophthalic anhydride, hexahydrophthalic acid or anhydride, adipic acid, isophthalic acid, sebacic acid, succinic acid, and dimerized fatty acids.
  • Polyols useful in the preparation of the polyesters are materials such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, butylene glycols, neopentyl glycol, 1,3- and
  • 1,4-butane diols 1,5-pentane diol, 1,6-hexanediol, glycerol, 1,1,1-trimethylolpropane, bisphenol A, and hydrogenated bisphenol A. It is also possible to employ the corresponding oxides, such as ethylene oxide and propylene oxide, etc. Generally no more than about 20% of the polyols employed in the
  • triols preparation of a polyester are triols.
  • polyester-based molding compositions Another type of unsaturated polyester useful for preparation of polyester-based molding compositions is the group of materials known as vinyl esters. These are reaction products of saturated polyesters possessing secondary hydroxyl functionalities with vinyl group-containing acids or anhydrides such as acrylic acid or methacrylic acid. An example is the reaction product of an epoxy resin based on bis-phenol A with an
  • unsaturated carboxylic acid such as methacrylic acid.
  • Vinyl esters and their preparation are disclosed in US Patent 3,887,515.
  • the unsaturated polyester is generally employed in the composition at a level of between 20 and 50%, preferably 36% to 45%, by weight based on the weight of polyester, monomer, and low profile additive employed. In practice, it is usually employed as a 60-65% by weight solution in the olefinically-unsaturated monomer used for
  • the olefinically unsaturated monomer employed in the molding composition of the invention is a material which is copolymerizable with the unsaturated ester to cause crosslinking which effects the curing of the polyester.
  • the monomer also serves the function of dissolving the
  • polyester thereby facilitating its interaction with the other components of the composition.
  • Sufficient monomer is employed to provide convenient
  • the monomer is generally employed in the composition at a level of between 30 and 70%, preferably 40 to 55%, by weight based on the weight of polyester, monomer, and any low profile additive employed.
  • olefinically unsaturated monomer is styrene, although other monomers such as vinyl toluene isomers, methyl methacrylate, acrylonitrile, and substituted styrenes like chlorostyrene and
  • alpha-methyl styrene may also be employed.
  • thermoplastic low profile additive preferably a ⁇ oly(vinyl acetate).
  • Suitable vinyl acetate polymer low profile additives are poly(vinyl acetate) homopolymers and
  • thermoplastic copolymers containing at least 50% by weight of vinyl acetate include, for example, carboxylated vinyl acetate polymers which are copolymers of vinyl acetate and
  • ethyle ⁇ ically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid and the like or anhydrides such as maleic anhydride; vinyl acetate/vinyl chloride/ maleic acid terpolymer, and the like; etc.
  • the useful vinyl acetate polymer low profile additives ordinarily have molecular weights within the range from 10,000 to 250,000, preferably from 25,000 to 175,000. They are usually employed in the composition at a level of 5 to 25 percent by weight, preferably 10 to 20 percent by weight, based on the total weight of polyester resin, low profile additive, and monomer.
  • thermoplastic low profile additives besides poly(vinyl acetate)s should also serve in the compositions of the invention.
  • examples of such materials are: poly(methyl methacrylate),
  • polystyrene polyurethanes
  • saturated polyesters saturated polyesters
  • ground polyethylene powder ground polyethylene powder
  • compositions of the invention is a reinforcing filler such as glass fibers or fabrics, carbon fibers and fabrics, asbestos fibers or fabrics, various organic fibers and fabrics such as those made of polypropylene, acrylonitrile/vinyl chloride copolymer, and others known to the art.
  • a reinforcing filler such as glass fibers or fabrics, carbon fibers and fabrics, asbestos fibers or fabrics, various organic fibers and fabrics such as those made of polypropylene, acrylonitrile/vinyl chloride copolymer, and others known to the art.
  • Such materials are generally employed at a level between 5 and 75 % by weight of the total composition, preferably 15 to 50 % by weight.
  • compositions of the invention are also included in the compositions of the invention.
  • a blocked polyisocyanate which is generally employed at a level of 1-20 parts per hundred, and preferably 1-10 parts per hundred, based on the total weight of the resin, the monomer, and the low profile additive.
  • a blocked isocyanate is an adduct of an isocyanate and an isocyanate-reactive material, this adduct being stable at room temperature where processing takes place, but dissociating to regenerate the isocyanate functionality at some temperature above room temperature, usually between 120°C and 250°C.
  • the regenerated isocyanate is then free to react with compounds containing active hydrogen to form more thermally stable units such as urethane
  • isocyanates which are useful in the compositions of the invention are materials such as tetramethylene diisocyanate, hexamethylene diisocyanate (HMDI), 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, isophorone diisocyanate (IPDI), xylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, and straight or branched urethane polymers
  • prepolymers prepared by reaction of a toluene diisocyanate (TDI), or a methylenediphenylene diisocyanate (MDI) or polymeric form thereof
  • TDI toluene diisocyanate
  • MDI methylenediphenylene diisocyanate
  • polymeric MDI polymeric MDI
  • a polyalkylene oxide diol such as polypropylene oxide diol.
  • Materials having three isocyanate groups may also be employed.
  • blocking groups are compounds having a single active hydrogen atom.
  • blocking agents for isocyanates are:
  • phenols for example, nonyl phenol, resorcinol, cresols, and bisphenol A.
  • imidazoles for example, imidazole, 1- or 2- methylimidazole, 4-phenylimidazole, 2,4,5-triphenylimidazole, 2,2'-bis(4,5-dimethylimidazole, and 4 , 5-diphenylimidazole.
  • pyrazoles for example, pyrazole, 3-methylpyrazole, 3,5-dimethylpyrazole, and
  • oximes for example, 2-butanone oxime, dimethyl glyoxime, cyclohexanone oxime,
  • materials having acidic hydrogen attached to carbon such as acid esters, diketones, and beta-dicarbonyl compounds generally; for example, dialkyl malonates, 2,4-pentanedione, and ethyl acetoacetate.
  • hydroxamic esters for example, benzyl methacrylohydroxamate (BMH), and acetohydroxamic acid.
  • triazoles for example, benzotriazole, methylbenzotriazole, and 1,2,4-triazole.
  • alcohols for example, benzyl alcohol, ethanol, and butanol.
  • carbodiimides for example, carbodiimide reacts with isocyanate to form uretonimine.
  • furazon N-oxides which react by opening the heterocyclic ring to form isocyanates.
  • the dissociation temperature of a blocked isocyanate is generally a function of the structure of the blocking group, with alcohols > lactams > phenols > oximes > active methylene compounds.
  • Aromatic blocked isocyanates usually dissociate at lower temperatures than their aliphatic counterparts. Blocked isocyanate compounds have been used in the coatings and related industries for many years. However, most blocked isocyanates have been marketed with solvents present. These solvent- containing materials are not suitable for use in the molding process for fiber reinforced plastic since this process cannot tolerate the presence of
  • composition comprising a blend of a thermoplastic polyester and a prepolymer derived from reaction of an organic polyisocyanate with an organic compound containing at least two isocyanate-reactive groups, this prepolymer containing blocked isocyanate groups.
  • This molding composition is not based on an unsaturated polyester resin, does not employ an olefinically unsaturated monomer or a low profile additive, and does not contain an isocyanate-reactive material as used in the present invention. Products produced using this molding composition are stated to have improved impact performance.
  • Japanese Kokai Patent No. 57-3819 discloses a thermosetting polyester resin molding composition comprising an unsaturated polyester resin and blocked isocyanate. This molding composition does not include an isocyanate-reactive material
  • compositions comprising an unsaturated polyester and a low molecular weight olefinically unsaturated blocked isocyanate crosslinker. Molded products made from the composition are stated to have
  • the isocyanate-reactive materials which are useful in the thermosetting molding composition of the invention are materials which contain active hydrogen atoms, such as polyether polyols, polyester polyols different from the unsaturated polyester resin (including those derived from polylactones), hydroxyl group-containing vinyl polymers,
  • isocyanate-reactive materials are employed at levels between 1 and 20 parts per hundred, preferably 1 to 10 pph, based on the total weight of the resin, the monomer, and the low profile additive.
  • Polyols are the preferred isocyanate-reactive materials.
  • suitable polyols are: hydroxyl-containing vinyl based polymers such as copolymers of vinyl acetate or other vinyl esters with hydroxyl containing unsaturated monomers, terpolymers of vinyl chloride and vinyl acetate (or other vinyl esters) with hydroxyl containing
  • polyester polyols, diols, and triols such as DEG/adipate, ethylene-butylene/adipate, condensation products of diols with dicarboxylic acids having more than 6 carbon atoms, and lactone polyols such as
  • polycaprolactones polyether polyols, diols, and triols, such as polypropylene oxide and ethylene oxide capped PPO (which yields primary hydroxyls); and amine-terminated polyols such as amino
  • the molding compositions of the invention may also contain one or more conventional additives, which are employed for their known purposes in the usual amounts.
  • additives which are employed for their known purposes in the usual amounts.
  • the following are illustrative of such additives:
  • polymerization initiator is employed in a
  • catalytically effective amount such as from about 0.3 to about 2 to 3 weight percent, based on the total weight of the polyester, monomer, and low profile additive;
  • Fillers such as clay, alumina trihydrate, silica, calcium carbonate, and others known to the art; 3. Mold release agents or lubricants, such as zinc stearate, calcium stearate, and others known to the art; and
  • Rubbers or elastomers such as: a) homopolymers or copolymers of conjugated dienes containing from 4 to 12 carbon atoms per molecule (such as 1,3-butadiene, isoprene, and the like), the polymers having a weight average molecular weight of 30,000 to 400,000 or higher, as described in US Patent 4,020,036; b) epihalohydrin homopolymers, copolymers of two or more epihalohydrin monomers, or a copolymer of an epihalohydrin monomer(s) with an oxide monomer(s) having a number average molecular weight (M n ) which varies from 800 to 50,000 as described in US Patent 4,101,604; c) chloroprene polymers including homopolymers of chloroprene and copolymers of chloroprene with sulfur and/or with at least one copolymerizable organic monomer wherein chloroprene constitutes at least 50 weight percent of the organic monomer
  • elastomers such as copolymers consisting of from 85 to 99.5 percent by weight of a C 4 -C 7 olefin combined with 15 to 0.5 percent by weight of a conjugated multi-olefin having 4 to 14 carbon atoms, and
  • copolymers of isobutylene and isoprene where a major portion of the isoprene units combined therein have conjugated diene unsaturation, as described in US Patent 4,160,759.
  • Thickening agents are also frequently employed in the compositions of the invention.
  • thickening agents include magnesium oxide, calcium oxide, zinc oxide, barium oxide, calcium hydroxide, magnesium hydroxide, and mixtures thereof.
  • Thickening agents are normally employed in proportions of from about 0.1 to about 6 percent by weight, based on the total weight of the polyester resin, monomer, and low profile additive.
  • Alumina Trihydrate a commercially-available
  • Desmocap 11a a branched aromatic urethane polymer with ether groups, containing 2.4% blocked NCO content. This is a solid material available from Mobay Corporation.
  • Desmocap 12a a linear aromatic urethane polymer with ether groups, containing 1.7% blocked NCO content. This is a solid material available from
  • MR-13017 Isophthalic acid modified polyester resin available from Aristech Chemical, containing about 35 weight percent styrene.
  • MR-13031 Orthophthalic acid modified polyester resin available from Aristech Chemical, containing about 35 weight percent styrene.
  • Trigonox 29B75 a peroxy ketal available
  • UCAR ® VYES-4 a terpolymer that contains approximately 29% primary hydroxyls, available from
  • Nonyl phenol (I) was obtained as a 99% mixture of monoalkyl phenols.
  • the MDI terminated polyoxyalkylene glycol (II) was obtained as a 75% solution in styrene.
  • the isocyanate content of (II) was determined by the method given by Siggia in
  • polyoxypropylene glycol was calculated as shown below.
  • g(I) g(II) ⁇ g isocyanate ⁇ 1 g ⁇ mole ⁇ 220 g ⁇ g -1 ⁇ mol -1
  • Blocked isocyanates synthesized in this work are discussed below. Each was composed of MDI, nonyl phenol (as the blocker), and varied by the molecular weight of propylene glycol polyol. No free
  • isocyanate was present due to blocking with nonyl phenol.
  • a blocked isocyanate was prepared from a 75% solution in styrene of an isocyanate prepolymer based on MDI and a 2000 molecular weight polypropylene oxide diol.
  • the free NCO content of this prepolymer solution was 2.4 % before blocking.
  • a blocked isocyanate was prepared from a 50% solution in styrene of an isocyanate prepolymer based on MDI and a 2000 molecular weight polypropylene oxide diol.
  • the free NCO content of this prepolymer solution was 0.5% before blocking.
  • compositions of the invention are prepared by mixing the components in a suitable apparatus such as a Hobart mixer, at temperatures on the order of about 20°C to about 50°C.
  • thermosetting resin and the low profile additive are added in liquid form by preparing a solution of these
  • compositions can be molded into thermoset articles of desired shape, particularly thermoset articles such as automobile body parts.
  • the actual molding cycle will depend upon the particular composition being molded as well as upon the nature of the cured product desired. Suitable molding cycles are conducted on the order of about 100°C to about 182°C for periods of time ranging from about 0.5 minutes to about 5 minutes. This depends on the particular peroxide catalyst employed.
  • Fiberglass (as a percentage
  • the mixer was again stopped, a weighed amount of thickening agent was added, and then this was mixed into the paste using a slow to medium speed over a period of 2-3 minutes.
  • the mixer was stopped again and about 175 grams of the paste were removed from the pan using a large spatula, and transferred to a wide-mouth 4 oz bottle.
  • the bottle was capped, and the paste sample was stored in the capped bottle at room temperature and viscosity was measured periodically using a model HBT 5X Brookfield Synchro-Lectric Viscometer on a Helipath.
  • the composition was reweighed and styrene loss was made up, and chopped glass fibers were added slowly to the pan with the mixer running on slow speed. The mixer was then run for about 30 seconds after all the glass was in the paste. This short mixing time gave glass wet-out without degradation of the glass. The pan was then removed from the mixer and separate portions of the BMC mix of about 1200 grams each were removed using a spatula and were
  • the weight of the BMC added to the foil varies with the molding application.
  • the thickener if used, was next mixed into the paste over a period of 2-3 minutes, the mixer was stopped and about 175 grams of paste were removed from the container and transferred to a wide mouth 4 oz bottle. This paste sample was stored in the capped bottle at room temperature and its viscosity was measured
  • Synchro-Letric Viscometer on a Helopath Stand The remainder of the paste was next added to the doctor boxes on the SMC machine where it was further combined with fiber glass (about 1 inch fibers).
  • the sheet molding compound (SMC) was then allowed to mature to molding viscosity and was then molded into the desired articles.
  • the top and bottom temperatures were 295-305 °F, 1200g samples of molding compound were employed, and the molded part thickness was 0.120".
  • the molding pressure which can be varied from 0 to 1000 psi, was run at maximum pressure.
  • the panels were laid on a flat surface, weighted to keep them flat, and allowed to cool overnight.
  • the molded panels were measured with a micro caliper from corner to corner in all four directions to determine shrinkage, which is an average of the four readings. These panels were used for surface smoothness determinations.
  • (a-b)/a inch/inch shrinkage
  • a the sum of the lengths of the four sides of the mold
  • b the sum of the lengths of the four sides of the molded panels.
  • the shrink control test compares the perimeter of a cold panel to the perimeter of the cold mold. A positive number indicates an expansion and vice-versa for a negative number as compared to the cold mold.
  • the units mil/inch indicate the amount of expansion (+) or contraction (-) in mils per inch of laminate (or panel perimeter).
  • the highest number denotes the best panel; the lowest number, the worst panel.
  • Example #3 gives a laminate about 20% lower in flex strength and about 40% lower in break energy than the material containing blocked isocyanate, Example #4.
  • the greater increase in break versus flex strength reveals that Example #4 not only achieves higher loads but also a greater amount of deflection before failure. Furthermore this improvement was obtained at the relatively low level of 1 phr of additive.
  • Table II also includes an evaluation of the surface properties, surface smoothness, and shrink control of the test composites. The blocked
  • polyisocyanate provided a minor but positive
  • Example #8 substantially improves the surface quality of the composite.
  • test compositions based on a ZMC formulation were prepared, each containing one of two blocked polyisocyanates, and three containing an additional reactive polyol. The styrene level was also varied. These compositions and amounts of ingredients are listed in Table III below. TABLE III
  • Desmocap 11A 2.35 x 2.35 2.35 x
  • Desmocap 11A was also compounded with polyisocyanate reactive polyols such as UCAR ® VYES-4 and TONE 0301.
  • the control formulation contained LP-40A.
  • control laminate #14 containing only LP-40A, attained slightly higher than typical BMC flex strength of approximately 11,000 psi and an energy to break of about 3.4 in-lb.
  • Composition #12
  • Desmocap 11A namely, 17,150 psi and 6.5 in-lb, respectively.
  • Desmocap 11A alone failed to confirm previous results of a significant increase in flex properties, showing a flex strength of 10,850 psi and an energy at break of 2.9 in-lb. It appears that to obtain a consistent increase in flex performance from a blocked
  • polyisocyanate the addition of a reactive polyol such as the UCAR ® VYES-4 is required.
  • a sheet molding formulation was made up with and without the blocked polyisocyanate Desmocap 12A and polyol UCAR ® VYES-4 in the manner described above, to test the effects of these additives in sheet molding compositions.
  • the ingredients and amounts are given in Table V below.
  • Desmocap 12A 1. 8 x
  • Table V shows the increase in physical properties in sheet molding compound as a result of adding a blocked polyisocyanate and additional polyol to the formulation. Increases of approximately 55% and 75% are seen in flex strength and break energy, respectively, over the LP-40A control. Izod impact results, though not as dramatic, are also higher than the control.

Abstract

Composition de moulage thermodurcissable permettant d'obtenir des produits moulés présentant une plus grande résistance et une surface plus lisse, procédé de production de cette composition et produits réalisés à l'aide de cette dernière. La composition comprend a) une résine polyester insaturée; un monomère à insaturation oléfinique; un additif à faible profil thermoplastique; une charge de renforcement; éventuellement, également un polyisocyanate bloqué et une substance réactive à l'isocyanate différente de la résine polyester insaturée.
EP19920923160 1991-09-30 1992-09-30 Compositions en plastique polyester thermodurcissables contenant un polyisocyanate bloque et une substance reactive a l'isocyanate Withdrawn EP0559888A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US76749891A 1991-09-30 1991-09-30
US767498 1991-09-30
US94831292A 1992-09-25 1992-09-25
US948312 1992-09-25

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EP0559888A1 true EP0559888A1 (fr) 1993-09-15

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EP (1) EP0559888A1 (fr)
JP (1) JPH06504087A (fr)
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WO (1) WO1993007216A1 (fr)

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FR2756833B1 (fr) * 1996-12-06 1999-02-26 Cray Valley Sa Composition thixotrope et son procede de fabrication
US6092343A (en) * 1998-07-16 2000-07-25 Therma-Tru Corporation Compression molded door assembly
US20010031830A1 (en) * 1999-04-26 2001-10-18 Probir K. Guha Composite molding compound additive
WO2007134988A1 (fr) * 2006-05-24 2007-11-29 Wacker Polymer Systems Gmbh & Co. Kg Utilisation de polyvinylesters à fonction silane en tant qu'additif de profil bas
JP5165293B2 (ja) * 2007-07-05 2013-03-21 本田技研工業株式会社 炭素繊維強化シート状成形材料及びその製造方法
JP5165292B2 (ja) * 2007-07-05 2013-03-21 本田技研工業株式会社 炭素繊維強化シート状成形材料及びその製造方法
CN103965604B (zh) 2013-01-29 2018-02-16 康廷南拓结构塑料有限公司 热固性多元醇组合物及其使用方法
CN108587127A (zh) * 2018-05-14 2018-09-28 安徽大学 一种无卤阻燃型高韧性团状模塑料及其制备方法
JP7182422B2 (ja) * 2018-10-12 2022-12-02 大塚化学株式会社 光反射体材料、光反射体の製造方法、光反射体及び照明器具

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US4421894A (en) * 1979-03-02 1983-12-20 Olin Corporation Polyurethane oligomer impact and shrinkage modifiers for thermoset polyesters
US4542177A (en) * 1984-06-29 1985-09-17 Mobay Chemical Corporation Thermoplastic polyester molding composition having an improved impact performance
ATE120771T1 (de) * 1989-03-31 1995-04-15 Union Carbide Chem Plastic Polyvinylether als schrumpfungskontrollmittel.

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CA2097330A1 (fr) 1993-03-31
JPH06504087A (ja) 1994-05-12

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