GB2108987A

GB2108987A - In-mold coating composition and method of in-mold coating

Info

Publication number: GB2108987A
Application number: GB08222414A
Authority: GB
Inventors: David S Cobbledick; Donald F Reichenbach; Henry Shanoski
Original assignee: General Tire and Rubber Co
Current assignee: Aerojet Rocketdyne Holdings Inc
Priority date: 1981-11-02
Filing date: 1982-08-03
Publication date: 1983-05-25
Also published as: BR8205098A; ES515071A0; ZA825562B; JPS58125762A; AU8670982A; GB2108987B; SE8204737D0; SE8204737L; FR2515666B1; DE3229292C2; ES8308344A1; DE3229292A1; JPS6019941B2; IT1195951B; FR2515666A1; MX173523B; SE455947B; AU533510B2; CA1186429A; IT8223105A0

Abstract

An FRP molding can be in-mold coated using a one-component free radical peroxide initiated composition of (a) a polymerizable oligomer selected from the group consisting of (1) a polyurethane based oligomer having at least two acrylate groups, (2) an epoxy based oligomer having at least two acrylate groups and (3) a polyester based oligomer having a plurality of internal ethylenically unsaturated groups and mixtures of the same, (b) a copolymerizable ethylenically unsaturated monomer, (c) a zinc salt of a fatty acid having at least 10 carbon atoms, (d) an accelerator for the peroxide initiator and (e) polyvinyl acetate. Optionally and desirably the composition additionally contains (f) a mono- unsaturated compound having a -CO- group and a -NH2, -NH- and/or -OH group, (g) a liquid copolymerizable compound having from 2-4 vinyl groups, being free of urethane, cycloaliphatic and aromatic groups and having a molecular weight of up to about 1500, (h) a calcium salt of a fatty acid having at least 10 carbon atoms and (i) a filler.

Description

SPECIFICATION In-mold coating composition and method of in-mold coating This invention relates to a thermosetting in-mold coating composition useful for in-mold coating a molded fiberglass reinforced thermoset plastic such as a polyester resin or a vinyl ester resin (FRP) molding or part that does not require the combining of two or more components immediately prior to use.

A major deficiency of compression molded thermoset glass fiber reinforced polyester (FRP) moldings is surface imperfections such as pits, pores, surface cracks, waviness and sink marks. The inmold coating process of U.S. Patent 4,081,578 generally overcomes these imperfections by molding a low viscosity thermoset on top of the FRP in a second molding operation. The composition described in U.S. Patent 4,081,578 contains free hydroxyl as well as isocyanate groups that co-react at room temperature, resulting in a limited (about one-half hour) pot life. In practice, the reactive ingredients are kept apart, and combined only immediately prior to application. This necessitates dual pumping equipment and an accurate metering device, which increase the cost and complexity of the system. A single component coating would thus offer a significant advantage.

Therefore, it is an object of this invention to avoid the difficulties alluded to and to provide a process for in-mold coating an FRP molding with a one-component coating composition.

Another object of this invention is to provide a one component composition suitable for in-mold coating an FRP molding.

A further object of this invention is to provide a cured molded FRP molding or part with an adherent coating in-mold coated with a one component in-mold coating composition.

An FRP molding can be in-mold coated using a one-component free radical peroxide initiatable composition of (a) a polymerizable oligomer selected from the group consisting of (1) a polyurethane based oligomer having at least two acrylate groups, (2) an epoxy based oligomer having at least two acrylate groups and (3) a polyester based oligomer having a plurality of internal ethylenically unsaturated groups, and mixtures of the same, (b) a copolymerizable ethylenically unsaturated monomer, (c) a zinc salt of a fatty acid having at least 10 carbon atoms, (d) an accelerator for the peroxide initiator and (e) polyvinyl acetate.Optionally and desirably the composition additionally contains (f) a mono-unsaturated compound having a -CO- group and a -NH2, -NH- and/or -OH group, (g) a liquid copolymerizable compound having from 2-4 vinyl groups, being free of urethane, cycloaliphatic and aromatic groups and having a molecular weight of up to about 1500, (h) a calcium salt of a fatty acid having at least 10 carbon atoms and (i) a filler.

Compositions within the invention can flow well and be stable for about a week even when containing the peroxide. It can be molded in a short period of time. The resulting thermoset coating exhibits good adhesion to different FRP substrates and will accept many paint finishes obviating the need for a primer.

The polymerizable or crosslinkable diacrylate terminated polyurethane oligomer may be a polyesterurethane diacrylate, a polyetherurethane diacrylate or a polyesteretherurethane diacrylate or other polyurethane oligomer having more than two acrylate groups. These materials may be made by reacting a polyetherdiol (e.g., a polypropylene ether diol), polyesterdiol (e.g., a polyethylene adipate diol) and/or a polyetherester diol (e.g., a polypropylene ether adipate diol), or triol etc., and so forth with a diisocyanate like tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate and the like in an amount sufficient to form an isocyanate terminated polyurethane prepolymer which is then reacted with hydroxy propyl acrylate, hydroxy ethyl acrylate, hydroxy ethyl methacrylate and so forth to form the diacrylate terminated polyurethane oligomer or polymer.

Mixtures of these acrylate terminated polyurethane oligomers may be used. The term "acrylate" as used here is intended to cover methacrylate and ethacrylates as well as acrylates. Of these materials it is preferred to use a diacrylate polyesterurethane oligomer. Acrylate terminated polyurethane oligomers, e.g., curable by light, ultraviolet, electric beam and/or infrared and so forth, are well known, and sometimes are referred to as irradiation or radiation curable materials.

The epoxy based oligomer having at least two acrylate (or methacrylate or ethacrylate) groups is prepared by reacting acrylic acid, methacrylic acid or ethacrylic acid and so forth with an epoxy based oligomer or resin such as a Bisphenol A epoxy, a tetrabromo Bisphenol A epoxy, phenolic novolak epoxy, tetraphenylolethane epoxy, dicycloaliphatic epoxy and so forth. Mixtures of these epoxy based oligomers may be used. Of these materials it is preferred to use a diacrylate terminated Bisphenol A epoxy oligomer. These materials are well known. For more information on these materials see "Heat Resistant Vinyl Ester Resin," M. B. Launikitis, Technical Bulletin, SC:1 16-76, Shell Chemical Company, June, 1976 and Shell Chemical Company Technical Bulletins SC: 1 6-76 and SC: 60-78.

The polyester based oligomer having a plurality of internal ethyienically unsaturated groups used may be made by copolymerizing maleic anhydride and an alkylene oxide of 2 to 4 carbon atoms such as propylene oxide, ethylene oxide, butylene oxide, isobutylene oxide and so forth and mixture thereof.

Propylene oxide and mixtures of propylene oxide and ethylene oxide are preferred. The alkylene oxide may be used in a molar ratio greater than the maleic anhydride to provide a polyester which is essentially or all OH terminated, e.g., a polyester diol. Up to about 50 mol % of the maleic anhydride may be replaced with a saturated an hydride such as phthalic anhydride or other an hydride and mixture thereof. A telogen like fumaric acid also may be used. It is preferred to use maleic anhydride. These unsaturated polyesters may be made in benzene, styrene or other solvent using a double metal cyanide catalyst as shown in U.S. Patent No. 3,538,043. As shown in said patent an isomerization catalyst such as piperidine is used to isomerize the maleate double bonds of the polyester to fumarate double bonds.Morpholine, also, may be used as an isomerization catalyst as shown by U.S. Patent No.

3,576,909. These polyesters may have molecular weights of from about 800 to 2500, preferably from about 1000 to 1 500. Polyesters made by reacting maleic anhydride or maleic acid, fumaric acid, itaconic acid, or citraconic acid with a glycol like propylene glycol, dipropylene glycol, 1 ,4-butane diol, bisphenol A and so forth including minor amounts of phthalic acid or phthalic anhydride and other diols and dicarboxylic acids may be used. The substantially aliphatic polyesters like the fumarate polyesters made using the double metal cyanide catalysts as described above are preferable to use.For more information on making unsaturated polyesters see "Encyclopedia of Polymer Science and Technology", Interscience Publishers, a division of John Wiley 8 Sons, Inc., New York, Vol. 11, 1 969, pages 129 to 168.

An organic free-radical or free radical generating initiator (catalyst) such as a peroxide is used to catalyze the copolymerization or crosslinking of the ethylenically unsaturated oligomer and the other ethylenically unsaturated materials. Examples of free-radical initiators include tertiary butyl perbenzoate, tertiary butyl peroctoate in diallyl phthalate, diacetyl peroxide in dimethyl phthalate, dibenzoyl peroxide, di(p-chlorobenzoyl) peroxide in dibutyl phthalate, di(2,4-dichlorobenzoyl) peroxide with dibutyl phthalate, dilauroyl peroxide, methyl ethyl ketone peroxide, cyclohexanone peroxide in dibutyl phthalate, 3,5-dihydroxy-3,4-dimethyl-l 1,2-dioxacyclopentane, t-butylperoxy(2-ethyl hexanoate), caprylyl peroxide, 2,5-dimethyl-2,5-di(benzoyl peroxy) hexane, 1 -hydroxy cyclohexyl hydroperoxide-1, t-butyl peroxy (2-ethyl butyrate), 2,5-dimethyl-2,5-bis(t-butyl peroxy) hexane, cumyl hydroperoxide, diacetyl peroxide, t-butyl hydroperoxide, ditertiary butyl peroxide, 3,5-dihydroxy-3,5- dimethyl-1 ,2-oxacyclopentane, and 1 ,1-bis(t-butyl peroxy)-3,3,5-trimethyl cyclohexane and the like and mixtures thereof. It is desirable sometimes to use mixtures of initiators to take advantage of their different decomposition rates and times at different temperatures and so forth. A preferred initiator to use is tertiary butyl perbenzoate. The peroxide initiator should be used in an amount sufficient to overcome the effect of the inhibitor present or to be added and to cause crosslinking or curing of the ethylenically unsaturated materials.In general the peroxide initiator may be used in an amount of up to about 5%, preferably up to about 2%, by weight based on the weight of the ethylenically unsaturated materials employed in the in-mold coating composition.

An accelerator is used for the peroxide initiator and is material such as a drier, e.g., cobalt octoate. Other materials which may be used are zinc naphthenate, lead naphthenate, cobalt naphthenate and manganese naphthenate. Soluble Co, Mn and Pb salts of linoleic acid, also, may be used. Only small amounts by weight of the accelerator need be used. In general the accelerator is used in an amount of from about 0.05 to 2 parts by weight per 100 parts by weight of the polymerizable oligomer.

A minor amount by weight of a zinc salt of a fatty acid having at least 10 carbon atoms, also, is employed in the in-mold coating composition and appears to function as a mold release agent and as a secondary accelerator for the cure. Fatty acids are well known. See "Organic Chemistry", Fieser and Fieser, D. C. Heath and Company, Boston, 1944, pages 88,381-390, 398 and 401 and "Hackh's Chemical Dictionary", Gran, McGraw Hill Book Company, New York, 1969, page 261. Mixtures of zinc salts of the fatty acids can be used. Examples of some zinc salts are zinc palmitate, zinc stearate, zinc ricinoleate and the like. It is preferred to use the zinc salt of a saturated fatty acid such as zinc stearate.

See, also, "Whittington's Dictionary of Plastics", Whittington, Technomic Publishing Co., Inc., Stamford, Conn., 1968, pages 35, 102 and 261. The zinc salt generally is used in an amount such as from about 0.2 to 5 parts by weight per 100 parts by weight of the polymerizable oligomer.

Optionally and desirably small amounts by weight of a calcium salt of a fatty acid having at least 10 carbon atoms, e.g., from about 0.2 to 5 parts by weight of calcium salt per 100 parts by weight of the polymerizable oligomer, are used in the in-mold coating composition as a mold release agent and to control the rate of the cure. Fatty acids are well known, see above. Mixtures of calcium salts of the fatty acids can be used. Examples of some calcium salts are calcium stearate, calcium palmitate, calcium oleate and the like. It is preferred to use the calcium salt of a saturated fatty acid like calcium stearate.

Polyvinyl acetate is employed as a low-shrink or low profile additive in the in-mold composition.

It, also, improves paint adhesion to the in-mold coating. The polyvinyl acetate is employed in a minor amount by weight as compared to the total weight of the ethylenically unsaturated materials in the inmold coating composition and sufficient for paint adhesion. In general the polyvinyl acetate is employed in an amount of from about 40 to 80 parts by weight per 100 parts by weight of the polymerizable oligomer.

A copolymerizable ethylenically unsaturated monomer is used in an amount at least sufficient to copolymerize with and to crosslink the polymerizable oligomer and includes styrene (preferred), alpha methyl styrene, vinyl toluene, t-butyl styrene, chlorostyrene, methyl methacrylate, diallyl phthalate (with styrene or methyl methacrylate and the like), triallyl cyanurate, triallyl isocyanurate, divinyl benzene, methyl acrylate and so forth and mixtures thereof. The unsaturated monomer is used generally in an amount of from about 80 to 1 50 parts by weight per 100 parts by weight of the polymerizable oligomer.

Optionally and desirably there may be used in the coating composition for further copolymerization and crosslinking and to improve hardness of the resulting coating a mono ethylenically unsaturated compound having a -C 0-- group and having a -N H2, -NH- and/or -OH group. Examples of such monomeric compounds are hydroxyl propyl methacrylate (preferred), hydroxyethyl methacrylate, hydroxy ethyl acrylate hydroxy ethyl crotonate, hydroxypropyl acrylate, hydroxy polyoxypropylene acrylate, hydroxy polyoxypropylene methacrylate, hydroxy polyoxyethylene methacrylate, acrylamide, methacrylamide, N-hydroxymethyl acrylamide, N-hydroxymethyl methacrylamide and so forth and mixtures of the same.These compounds generally may be used in an amount of from about 0 to 120 parts by weight per 100 parts by weight of the polymerizable oligomer.

Also, optionally and preferably, there may be used in partial replacement of the polymerizable oligomer a liquid copolymerizable or crosslinkable acrylate compound having from 2 to 4 vinyl groups, being free of urethane, cycloaliphatic and aromatic groups and having an average molecular weight of up to about 1 500. Examples of such compounds include trimethylol propane trimethacrylate, trimethylol propane triacrylate, pentaerythritol tetracrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, tetraethylene glycol dimethacrylate, 1,3-butylene glycol diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, polyethylene glycol dimethacrylate or polyoxyethylene glycol dimethacrylate (preferred), pentaerythritol triacrylate, 1 ,6-hexanediol diacrylate, polypropylene glycol dimethacrylate, polyethylene propylene glycol diacrylate, and so forth and mixtures thereof. Since some of these reactive polyfunctional monomers may be made by reacting unsaturated acids and alcohols, they may contain some OH and/or COOH groups. The reactive polyfunctional monomers may be used generally in an amount of from about 0 to 120 parts by weight per 100 parts by weight of the polymerizable oligomer.

The unsaturated materials mentioned above, thus, are used in an amount sufficient to provide on cure (e.g., polymerization, copolymerization and/or crosslinking) a thermoset composition.

The monoethylenically unsaturated compound having a -C 0-- group and having a -NH2, -NH- and/or -OH group (like hydroxy propyl methacrylate) or the liquid copolymerizable acrylate compound having from 2 to 4 vinyl groups and being free of urethane, cycloaliphatic and aromatic groups (like polyethylene glycol dimethacrylate), or both of these compounds, should be used in the inmold coating composition where after curing it is to be painted with a water based system.

To prevent premature gelation of the ethylenically unsaturated materials and to provide for improved shelf-life or storageability inhibitors are added in the desired amount to the composition or are provided in the raw materials before use. Examples of inhibitors are hydroquinone, benzoquinone, p-t-butyl catechol and the like and mixture thereof.

The in-mold composition additionally optionally can be filled or compounded to give the desired viscosity and flow to the composition for molding and to afford the desired physical properties to the resulting thermoset coating. Fillers, also, may improve adhesion. Examples of such fillers or compounding ingredients are fillers like clay, talc, MgO, Mg(OH)2, CaCO3 and silica, other mold release agents, red iron oxide, TiO2, carbon black including conductive carbon black, color pigments, antidegradants, U-V absorbers, calcium silicate, paraffin wax, hollow glass or resin micro-spheres, thickening agents, other low shrink additives and the like. One preferred filler is talc which may be used in an amount of from about 50 to 1 50 parts by weight per 100 parts by weight of the polymerizable oligomer.The use of an electroconductive filler like conductive carbon black enables the coating to be painted by standard electrostatic painting techniques. Such conductive carbon black may be used in an amount of from about 5 to 1 5 parts by weight per 100 parts by weight of the polymerizable oligomer.

These fillers and compounding ingredients should be used in amounts sufficient to provide satisfactory results. However, care should be exercised in the use of high filler contents as this may give high viscosities and result in flow and handling difficulties. It is not desirable to use in the in-mold composition of this invention materials like carboxylated butadiene-styrene block copolymers or fatty alcohol phosphates.

For ease in handling, materials like polyvinylacetate may be dissolved in a reactive monomer like styrene. The viscosity of the oligomers may be reduced by dilution with styrene and the like. The ingredients of the in-mold composition should be readily mixed and handled at ambient or room temperature or temperatures below the polymerization temperature so that they may be readily pumped to the mold and injected into the same. The ingredients may be warmed or heated before or during mixing and mixed in steps to facilitate thorough mixing, dispersion and solution of the same.

With the peroxide initiator or catalyst the in-mold composition exhibits a shelf-like at room temperature (about 250C) of about a week, and without the initiator it exhibits a shelf life of several months at room temperature. The initiator is preferably added to the composition and thoroughly mixed therewith just before molding.

All of the ingredients of the in-mold coating composition should be kept dry or have a minimal amount of moisture or the water content should be controlled to obtain reproducible results and to prevent pore formation.

Mixing of the ingredients of the in-mold composition should be thorough. Injection or compression, transfer molding, or other molding apparatus or machines can be used for the in-mold coating. Molding apparatus and methods may be found in U.S. Patents Nos. 4,076,780; 4,076,788; 4,081,578; 4,082,486, 4,189,517; 4,222,929; 4,245,006, 4,239,796 and 4,239,808.Please see, also, "Proceedings of the Thirty-second Annual Conference Reinforced Plastics/Composites Institute", SPI, Washington, February, 1977, Griffith et al, Section 2-C, pages 1-3 and "33rd Annual Technical Conference, 1978 Reinforced Plastics/Composites Institute the Society of the Plastics Industry, Inc.," SPI, Ongena, Section 14-B, pages 1-7. The in-mold coating composition can be applied to the substrate and cured at a temperature of from about 290 to 31 O0F and at a pressure of about 1000 p.s.i. for from about 0.5 to 3 minutes.

The processes and products of the present invention can be used in the manufacture of automobile parts such as grille and headlamp assemblies, deck hoods, fenders, door panels and roofs as well as in the manufacture of food trays, appliance and electrical components, furniture, machine covers and guards, bathroom components, structural panels and so forth. The glass fiber reinforced thermoset plastic (FRP) such as the polyester resin or vinyl ester resin and glass fiber composition substrate to which the in-mold composition is applied can be a sheet molding compound (SMC) or a bulk molding compound (BMC) or other thermosetting FRP material as well as a high strength molding compound (HMC) or a thick molding compound. The FRP substrate can have from about 10 to 75% by weight of glass fibers.The SMC compound usually contains from about 25 to 30% by weight of glass fibers while the HMC compound may contain from about 55 to 60% by weight of glass fibers. The glass fiber reinforced thermoset plastic (FRP) substrate can be rigid or semirigid (may contain a flexibilizing moiety such as an adipate group in the polyester). The substrate, also, may contain other flexibilizing polymers, the elastomers and plastomers, such as the styrene-butadiene block copolymers.

Unsaturated polyester glass fiber thermosets are known as shown by "Modern Plastics Encyclopedia", 1975-1976,October, 1975, Vol.52, No. 10A, McGraw-Hill, Inc., New York, pages 61, 62 and 105 to 107; "Modern Plastics Encyclopedia", 1 979-1 980, October, 1979, Volume 56, Number 1 or, pages 55, 56, 58, 147 and 148 and "Modern Plastics Encyclopedia", 1980-81, October, 1980, Volume 57, Number 1 OA, pages 59, 60, and 1 51 to 1 53, McGraw-Hill, Inc., New York, N.Y. For information on vinyl ester resins see the Shell Chemical Company Technical Bulletins mentioned above.

The compositions of the present invention can exhibit good pumpability and flow in the mold.

They can give rapid cures as low as 75 to 90 seconds at 3000F. They, also, show good adhesion to paints and can be used not only as an in-mold coating to cover blemishes but as a good conductive coating for electrostatic painting and as a primer for most paint finish systems such as soluble acrylic lacquers, acrylic dispersion lacquers, water borne acrylic enamels, high solids solution acrylic enamels, acrylic non-aqueous dispersion and urethanes.

The following examples will serve to illustrate the present invention with more particularity to those skilled in the art. In these examples, the parts are parts by weight unless otherwise indicated.

Example 1 The following ingredients were mixed together: Parts by weight Ingredient A B C D E LP 90 150 150 150 150 225 UVITHANE 783 150 180 180 225 150 CHEMLINK 600 180 90 - - 90 Hydroxypropyl methacrylate - 90 - 90 180 Styrene 90 135 51 90 45 2% benzoquinone in styrene 13.5 1 5 9 12 1 5 Then the following ingredients were mixed in: Zine stearate 1.62 1.8 1.08 1.53 1.89 Cobalt octoate .54 .6 .36 .51 .63 (12% as Co in mineral oil) The following ingredients were then mixed in:: VULCAN carbon black 27 30 18 25.5 31.5 Tale (630) 159 180 108 156 192 To each composition 1 part by weight of the initiator TBPB was added per 100 parts by weight of the total in-mold composition.

The in-mold composition exhibited the following properties: Gel time at 2300F 7.3/330 9.1/336 4.5/316 7.7/318 14.4/320 minutes/peak temp. OF Brookfield viscosity 8800 6200 16000 8400 7600 at 860 F, &num;7 spindle at 100 rpm The above composition were then in-mold coated onto substrates of molded thermoset conventional polyesterstyrene-glass fibers compositions (about 25% glass fibers) containing in some instances additionally a carboxylated butadiene-styrene block copolymer at 1,000 psi and 3000F for about 2 minutes.The overall results obtained for the cured in-mold coating compositions are shown below: Hot strength Marginal Marginal Marginal Marginal Marginal (Delamination on opening mold) Adhesion to substrate Pass Pass Marginal Marginal Pass at best to pass Phase separation Yes Yes Yes None Yes (Surface continuity (minor) (minor7) or appearance of coating) Conductivity 160-165 165+ 150-160 155 165+ (Ransberg meter reading) Hardnes, pencil Fails Pass Pass Pass Pass ASTM D3363-74 B HB 2H 2H HB Finish properties Good Good Poor* Good Good (Paint acceptability) * To water based acrylics. Good for acrylic lacquers.

Example 2 The method of this example was similar to that of Example 1, above, except for the noted changes. The results obtained on in-mold coating were satisfactory.

The following ingredients were mixed together: Parts by weight Ingredient F G LP 90 75 100 UVITHANE783 100 75 CHEMLINK 600 - 25 Hydroxypropyl methacrylate 30 20 Styrene 30 10 2% benzoquinone in styrene 5 5 Then the following ingredients were mixed in: Zinc stearate .675 .675 Cobalt octoate .225 .225 (12% as Co in mineral oil) Calcium stearate .675 .675 The following ingredients were then mixed in: VULCAN carbon black 11 11 Talc 70 70 To each composition 1 part by weight of the initiator TBPB was added per 100 parts by weight of the total in-mold composition.

The resulting in-mold compositions, F and G, passed all of the tests shown for Runs A to E of Example 1, above.

Example 3 This example illustrates a preferred method for preparation of the in-mold coating composition prior to in-mold coating and curing. The ingredients were mixed in the order as shown below: LP 90 100.0 pbw CHEMLINK 600 25.0 pbw Hydroxypropyl methacrylate 20.0 pbw 2% benzoquinone in styrene 5.0 pbw 1. Charge these materials to the reactor and blend.

Styrene 5.0 pbw Zinc stearate 0.675 pbw 6.55 pbw Calcium stearate 0.675 pbw Cobalt octoate 0.200 pbw (12% as Co in mineral oil) 2. Pre-blend the above materials and charge to the reactor. After adding the above charge, heat to 44"0 (1 10"F) while mixing.

UVITHANE 783 (Preheated to 490C) 75.0 pbw 3. Add the UVITHANE 783 to the reactor and mix until the material is uniform. Cool to 380C (1000F).

VULCAN carbon black 11.0 pbw 4. Add the carbon black to the reactor and mix for 30 minutes. Hold the temperature at 380C (1O00F).

Talc (BEAVER WHITE 200) 70.0 pbw 5. Add the talc to the reactor and mix for 1 hour while holding the temperature at 380C (1 000F).

Remove Sample.

6. Check the gel time. If below 8 minutes, add 1 pbw of 2% benzoquinone in styrene and mix for 30 minutes. Recheck the gel time. Repeat the above procedure until the gel time is between 8 to 10 minutes.

7. Subtract the total number of the pbw of 2% benzoquinone in styrene additions made from the number 5 and add the difference as styrene. Mix for 30 minutes, degas for 1 5 minutes and filter through a 60 mesh screen. Store at 450F.

Brookfield viscosity 860 F, &num;7 Spindie &commat; 100 rpm, 13,000-15,000.

Gel time,* 2300 F. 8-10 minutes * 1.0 pbw of TBPB/100 pbw total composition. When making up material for checking the gel time, weigh out 100.0 gms total composition and add 1.00 gm of TBPB and mix thoroughiy before running gel test. pbw-parts by weight.

Example 4 The method of this example was similar to the preceding examples: Ingredient H I J K LP-90 100 100 100 100 EPOCRYL 370 75 CHEMPOL 4825 75 UVIMER 580 75 ALTAC 382 E 75 CHEMLINK 600 25 25 25 25 Hydroxypropyl methacrylate 20 20 20 20 Styrene 10 10 10 10 2% benzoquinone in styrene 5 5 5 5 Zine stearate 0.675 0.675 0.675 0.675 Calcium stearate 0.675 0.675 0.675 0.675 Cobalt octoate 0.225 0.225 0.225 0.225 (12% as Co in mineral oil) VULCAN 11 11 11 11 carbon black BEAVER WHITE 70 70 70 70 200, Talc To each composition 1 part by weight of the initiator TBPB was added per 100 parts by weight of the total in-mold coating composition.

Gel time at 230 F 5.75/314 8.3/324 15.9/322 8.7/323 Brookfield viscosity 12,800 10,200 at 860 F, &num;7 spindle at 100 rpm In-mold coating properties on molded thermoset glass fiberpolyestef styrene substrates: Hot strength Good Marginal Good Adhesion (scapel, a severe Pass Pass Fail test) to substrate Release from mold Good Good Good Did not mold well-poor flow along with poor release Phase separation None None None Conductivity 165 160-165 165 (Ransberg meter reading) Example 5 The method of this example was similar to the preceding examples:: Parts by weight Ingredient L M N O LP-90 100 100 100 100 UVITHANE 893 75 Polyester 75 UVIMER 530 75 NUPOL46-8012 75 CHEMLINK 600 25 25 25 25 Hydroxypropyl methacrylate 20 20 20 20 Styrene 10 - 10 2% benzoquinone in styrene 5 5 5 5 Zine stearate 0.675 0.675 0.675 0.675 Calcium stearate 0.675 0.675 0.675 0.675 Cobalt octoate 0.225 0.225 0.225 0.225 (12% as Co in mineral oil) VULCAN carbon black 11 11 11 11 BEAVER WHITE 70 70 70 70 200, Talc To each composition 1 part by weight of the initiator TBPB was added per 1 00 parts by weight of the total in-mold coating composition.

Gel time at 2300F 14.9/308 6.1/322 7.5/334 25.3/248 Brookfield viscosity 17,600' 14,400 - at 860 F, &num;7 spindle at 100 rpm In-mold coating properties on molded thermoset glass fiber-polyester-styrene substrates: Hot strength Good Marginal Good Poor Adhesion (scapel, a Pass Pass Fail severe test) to substrate Release from mold Good Good Good Did not mold well-poor cure caused sticking and poor release Phase separation None Yes Excessive Conductivity 1 65 1 65 (Ransberg meter reading) Of Examples 4 and 5 Runs H, I and L were the best.

Notes for Examples: LP-90--BAKELITE LP-90-40% by weight of polyvinyl acetate in styrene, viscosity of 1,800 centipoises at 250C. (Model LVT Brookfield viscometer &num;4 spindle at 60 rpm), specific gravity 20/200 C. (H20=1) of 1.008 and solidification temperature of 50C. Union Carbide Corp.

UVITHANE 783, a polymerizable urethane based material or oligomer, a diacrylate terminated polyesteurethane prepolymer. A viscous liquid (kg/l 1.3 at 250C) having a viscosity at 490C of 6002000 poise and at 820C of 50-110 poise, having an unsaturation (equiv./1 00 grams) of 0.17- 0.205 and having an isocyanate content (%) of .3 max. Thiokol/Chemical Division, Thiokol Corporation.

CHEMLINK 600 or CL 600-Polyoxyethylene glycol 600 dimethacrylate. Molecular weight of about 770. C36H660,7. The Ware Chemical Corp.

VULCAN-XC-72b. N472. Conductive furnace carbon black. Cabot Corp.

Talc-hydrous magnesium silicate.

TBPB-tertiary butyl perbenzoate.

EPOCRYL 370-Non-volatile diacrylate ester of a liquid Bisphenol A epoxy resin having a viscosity, poise, 250C (100% resin) of 9,000; an acidity eq./1 0O G of 0.007; an epoxide eq./1 0O G of 0.02; a Gardner color of 4; a weight/volume, Ib/U.S. gal, of 9.99; a flash point, OC > 204 and a viscosity, Gardner, 250C (80% w resin in xylene) of V-Y. Shell Chemical Co.

CHEMPOL 4825-( 19-4825) Solvent free epoxy acrylate resin which contains active acrylic unsaturation on the polymer molecule. It has an acid number of 3-10; a color of 1-4; a viscosity, centipoise, of 4000-6000 at 1400 F and 1400-1800 at 1 600 F and a weight per gallon of 9.8 10.0 Ibs. It may contain up to 2% by weight of free acrylic acid. Freeman Chemical Corp.

UMIVER 580-A polyethylenically unsaturated liquid oligomer having a high reactivity in free radical polymerization. An amber colored liquid at room temperature having a mild characteristic odor.

It has a viscosity (Gardner-Holdt) Z6-Z7 (200-500 poises), a color (Gardner-Holdt) of 3 max., a weight of 9.6+0.1 Ibs/U.S. gallon and a flash point (closed cup) of 2100F(approx). Polychrome Corporation.

ATLAC 382 E-lt is a Bisphenol A-polyester resin. ICI Americas Inc.

UVITHANE 893-A polymerizable urethane oligomer, a viscous liquid. It has a color, APHA, of 110 max.; a mild odor; a weight of 10 Ibs/gal at 770F; viscosity poises of 900-2200 at 1200 F, 80- 180 at 1 600F and 30-80 at 1 8O0F; an unsaturation equi./100 g. ofO.1 50-0.175 and an isocyanate content of 0.2% max. Thiokol Corporation.

Polyester-A polyester made by the copolymerization of propylene oxide, ethylene oxide, maleic anhydride, fumaric acid and phthalic anhydride using a double metal cyanide catalyst. It has been isomerized, and is OH terminated and has a molecular weight of about 1200.

UVIMER 530-A polyethylenically unsaturated liquid oligomer with extremely high reactivity in free radical polymerization. It has a viscosity (Gardner-Holdt) Z7Z8 (375-600 poises); a color (Gardner-Holdt) of 5 max.; a weight of 9.8+0.05 Ibs. per U.S. gallon and a flash point (closed cup) of 2100 F (approx.). Polychrome Corporation.

NUPOL 46-8012-A mixture of 70% acrylate terminated polymer, 28% styrene and 2% hydroxyethyl methacrylate.

Claims

Claims 1. A composition useful as a thermosetting molding composition comprising (a) a polymerizable oligomer selected from the group consisting of (1) a polyurethane based oligomer having at least two acrylate groups, (2) an epoxy based oligomer having at least two acrylate groups and (3) a polyester based oligomer having a plurality of internal ethylenically unsaturated groups, and mixtures of the same, (b) a copolymerizable ethylenically unsaturated monomer, (c) a zinc salt of a fatty acid having at least 10 carbon atoms, (d) an accelerator for a peroxide initiator and (e) polyvinyl acetate in a minor amount by weight as compared to the polymerizable materials and sufficient for paint adhesion, (f) optionally additionally containing a copolymerizable monoethylenically unsaturated compound having a -C 0- group and a -N H2, -NH- and/or -OH group, (g) optionally additionally containing for partial replacement of (a) a copolymerizable liquid compound having from 2 to 4 vinyl groups, being free of urethane, cycloaliphatic and aromatic groups and having a molecular weight of up to about 1500, (h) optionally additionally containing a calcium salt of a fatty acid having at least 10 carbon atoms and (i) optionally additionally containing a filler, said ethylenically unsaturated materials being' present in an amount sufficient on curing to provide a thermoset composition. 2. A composition useful as a thermosetting molding composition comprising (a) 100 parts by weight of a polymerizable oligomer selected from the group consisting of (1) a polyurethane based oligomer having at least two acrylate groups, (2) an epoxy based oligomer having at least two acrylate groups and (3) a polyester based oligomer having a plurality of internal ethylenically unsaturated groups, and mixtures of the same, (b) from about 80 to 1 50 parts by weight of a copolymerizable ethylenically unsaturated monomer, (c) from about 0.2 to 5 parts by weight of a zinc salt of a fatty acid having at least 10 carbon atoms, (d) from about 0.05 to 2 parts by weight of an accelerator for a peroxide initiator and (e) from about 40 to 80 parts by weight of polyvinyl acetate, (f) optionally additionally containing from about 0 to 120 parts by weight of a copolymerizable monoethylenically unsaturated compound having a -C 0-- group and a -NH2, -NH- and/or -OH group, (g) optionally additionally containing for partial replacement of (a) from about 0 to 1 20 parts by weight of a copolymerizable liquid compound having from 2 to 4 vinyl groups, being free of urethane, cycloaliphatic and aromatic groups and having a molecular weight of up to about 1 500, (h) optionally additionally containing from about 0.2 to 5 parts by weight of a calcium salt of a fatty acid having at least 10 carbon atoms and (i) optionally additionally containing a filler. 3. A composition according to claim 1 or claim 2 where said composition contains additionally an organic free radical peroxide initiator in an amount of up to about 5% by weight based on the weight of said ethylenically unsaturated materials. 4. A composition according to claim 1, claim 2 or claim 3 where (a) is a liquid diacrylate terminated polyesterurethane or a diacrylate ester of a liquid Bisphenol A epoxy resin, (b) is styrene, (c) is zinc stearate, (d) is cobalt octoate, (f) is hydroxy propyl methacrylate, (g) is polyoxyethylene glycol dimethacrylate having a molecular weight of about 770, (h) is calcium stearate and (i) comprises talc in an amount of from about 50 to 150 parts by weight and conductive carbon black in an amount of from about 5 to 15 parts by weight. 5. A composition according to claim 4 containing additionally up to about 2% by weight of tertiary butyl perbenzoate based on the weight of said ethylenically unsaturated materials. 6. The method which comprises in-moid coating a molded thermoset polyester resin or thermoset vinyl ester resin glass fiber composition containing from about 10 to 75% by weight of glass fibers with a thermosetting in-mold coating composition under pressure, at a temperature and for a period of time sufficient to cure said in-mold coating composition to form an adherent thermoset coating on said molded thermoset resin glass fiber composition, said in-mold coating composition comprising (a) a polymerizable oligomer selected from the group consisting of (1) a polyurethane based oligomer having at least two acrylate groups, (2) an epoxy based oligomer having at least two acrylate groups and (3) a polyester based oligomer having a plurality of internal ethylenically unsaturated groups and mixtures of the same, (b) a copolymerizable ethylenically unsaturated monomer, (c) a zinc salt of a fatty acid having at least 10 carbon atoms, (d) an accelerator for a peroxide initiator and (e) polyvinylacetate in a minor amount by weight as compared to the polymerizable materials and sufficient for paint adhesion, (f) optionally additionally containing a copolymerizable monoethylenically unsaturated compound having a -C 0-- group and a -NH2, -N H- and/or -OH group, (g) optionally additionally containing for partial replacement of (a) a copolymerizable liquid compound having from 2 to 4 vinyl groups, being free of urethane, cycloaliphatic and aromatic groups and having a molecular weight of up to about 1 500, (h) optionally additionally containing a calcium salt of a fatty acid having at least 10 carbon atoms, (i) optionally additionally containing a filler, said ethylenically unsaturated materials being present in an amount sufficient on curing to provide a thermoset composition, and (j) containing an organic free radical peroxide initiator in an amount of up to about 5% by weight based on the weight of said ethylenically unsaturated materials. 7. The method which comprises in-mold coating a molded thermoset polyester resin or thermoset vinyl ester resin glass fiber composition containing from about 10 to 75% by weight of glass fibers with a thermosetting in-mold coating composition under pressure, at a temperature and for a period of time sufficient to cure said in-mold coating composition to form an adherent thermoset coating on said molded thermoset resin glass fiber composition, said in-mold coating composition comprising (a) 100 parts by weight of a polymerizable oligomer selected from the group consisting of (1) a polyurethane based oligomer having at least two acrylate groups, (2) an epoxy based oligomer having at least two acrylate groups, and (3) a polyester based oligomer having a plurality of internal ethylenically unsaturated groups and mixtures of the same, (b) from about 80 to 1 50 parts by weight of a copolymerizable ethylenically unsaturated monomer, (c) from about 0.2 to 5 parts by weight of a zinc salt of a fatty acid having at least 10 carbon atoms, (d) from about 0.05 to 2 parts by weight of an accelerator for a peroxide initiator and (e) from about 40 to 80 parts by weight of polyvinyl acetate, (f) optionally additionally containing from about 0 to 1 20 parts by weight of a copolymerizable monoethylenically unsaturated compound having a ---6 0-- group and a -NH 2-NH- and/or -OH group, (g) optionally additionally containing for partial replacement of (a) from about 0 to 120 parts by weight of a copolymerizable liquid compound having from 2 to 4 vinyl groups, being free of urethane, cycloaliphatic and aromatic groups and having a molecular weight of up to about 1 500, (h) optionally additionally containing from about 0.2 to 5 parts by weight of a calcium salt of a fatty acid having at least 10 carbon atoms, (i) optionally additionally containing a filler and (j) an organic free radical peroxide initiator in an amount of up to about 5% by weight based on the weight of said ethylenically unsaturated materials. 8. The method according to claim 6 or claim 7 where (a) is a liquid diacrylate terminated polyesteurethane or a diacrylate ester of a liquid Bisphenol A epoxy resin, (b) is styrene, (c) is zinc stearate, (d) is cobalt octoate, (f) is hydroxy propyl methacrylate, (g) is polyoxyethylene glycol dimethacrylate having a molecular weight of about 770, (h) is calcium stearate and (i) comprises talc in an amount of from about 50 to 150 parts by weight and conductive carbon black in an amount of from about 5 to 1 5 parts by weight. 9. The method according to claim 8 in which said initiator is tertiary butyl perbenzoate and is used in an amount of up to about 2% by weight. 10. A composition according to any one of claims 1 to 5 substantially as any such composition herein described and exemplified. 11. A method according to any one of claims 6 to 9 substantially as any such composition herein described and exemplified. 12. A moulded thermosetting resin article whenever in-mold coated with a composition according to any one of claims 1 to 5 and 10. 13. A product produced by a method according to any one of claims 6 to 9 and 11. New claims or amendments to claims filed on 28 January 1 983. Superseded claims 1-9. New or amended claims:

1. A composition useful as a thermosetting molding composition comprising (a) a polymerizable oligomer selected from the group consisting of (1) a polyurethane based oligomer having at least two acrylate groups, (2) an epoxy based oligomer having at least two acrylate groups and (3) a polyester based oligomer having a plurality of internal ethylenically unsaturated groups, and mixtures of the same, (b) a copolymbrizable ethylenically unsaturated monomer, (c) a zinc salt of a fatty acid having at least 10 carbon atoms, (d) an accelerator for a peroxide initiator, (e) polyvinyl acetate in a minor amount by weight as compared to the polymerizable materials and sufficient for paint adhesion, (f) a copolymerizable monoethylenically unsaturated compound having a -C 0-- group and a -NH2, --NHH- andlor QH group, (g) optionally for partial replacement of (a) a copolymerizable liquid acrylate compound having from 2 to 4 vinyl groups, being free of urethane, cycloaliphatic and aromatic groups and having a molecular weight of up to about 1500, (h) optionally additionally containing a calcium salt of a fatty acid having at least 10 carbon atoms and (i) a filler, said ethylenically unsaturated materials being present in an amount sufficient on curing to provide a thermoset composition.

2. A composition according to claim 1 where (a) comprises an epoxy based oligomer having at least two acrylate groups.

3. A composition useful as a thermosetting molding composition comprising (a) 100 parts by weight of a polymerizable oligomer selected from the group consisting of (1) a polyurethane based oligomer having at least two acrylate groups, (2) an epoxy based oligomer having at least two acrylate groups and (3) a polyester based oligomer having a plurality of internal ethylenically unsaturated groups, and mixtures of the same, (b) from about 80 to 1 50 parts by weight of a copolymerizable ethylenically unsaturated monomer, (c) from about 0.2 to 5 parts by weight of a zinc salt of a fatty acid having at least 10 carbon atoms, (d) from about 0.05 to 2 parts by weight of an accelerator for a peroxide initiator, (e) from about 40 to 80 parts by weight of polyvinyl acetate, (f) up to about 120 parts by weight of a copolymerizable monoethylenically unsaturated compound having a -C O- group and a -NH2, -NH- and/or -OH group, (g) optionally additionally containing for partial replacement of (a) from about 0 to 120 parts by weight of a copolymerizable liquid acrylate compound having from 2 to 4 vinyl groups, being free of urethane, cycloaliphatic and aromatic groups and having a molecular weight of up to about 1500, (h) optionally additionally containing from about 0.2 to 5 parts by weight of a calcium salt of a fatty acid having at least 10 carbon atoms and (i) a filler comprising talc in an amount of from about 50 to 1 50 parts by weight and conductive carbon black in an amount of from about 5 to 15 parts by weight.

4. A composition according to claim 3 where (a) comprises an epoxy-based oligomer having at least two acrylate groups.

5. A composition according to any one of the preceding claims where said composition contains additionally an organic free radical peroxide initiator in an amount of up to about 5% by weight based on the weight of said ethylenically unsaturated materials.

6. A composition according to any one of the preceding claims where (a) is a liquid diacrylate terminated polyesterurethane or a diacrylate ester of a liquid Bisphenol A epoxy resin, (b) is styrene, (c) is zinc stearate, (d) is cobalt octoate, (f) is hydroxy propyl methacrylate, (g) is polyoxyethylene glycol dimethacrylate having a molecular weight of about 770, (h) is calcium stearate and (i) comprises talc in an amount of from about 50 to 1 50 parts by weight and conductive carbon black in an amount of from about 5 to 1 5 parts by weight.

7. A composition according to claim 6 where (a) is a diacrylate ester of a liquid Bisphenol A epoxy resin.

8. A composition according to claim 6 or claim 7 containing additionally up to about 2% by weight of tertiary butyl perbenzoate based on the weight of said ethylenically unsaturated materials.

9. A composition according to claim 1, where: (a) is either (i) a mixture of said epoxy based oligomer (2) and a said polyurethane based oligomer (1), optionally partially replaced by a said copolymerizable liquid (g) or (II) a said epoxy based oligomer (2) partially replaced by a said copolymerizable liquid (g), the said copolymerizable liquid (g) being, in either alternative (I) or (II), at least one polyoxyalkylene glycol based oligomer having two acrylate groups and having a molecular weight of up to 1500.

10. A composition according to claim 1 or claim 9, where: (a) is 100 parts by weight of a polymerizable epoxy based oligomer having at least two acrylate groups, (b) is from about 80 to 1 50 parts by weight of at least one said copolymerizable ethylenically unsaturated monomer, (c) is from about 0.2 to 5 parts by weight of at least one said zinc salt of a fatty acid having at least 10 carbon atoms, (d) is from about 0.05 to 2.0 parts by weight of at least one said accelerator for a peroxide initiator, (e) is from about 40 to 80 parts by weight of the polyvinyl acetate, (f) is from up to about 1 20 parts by weight of at least one copolymerizable monoethylenically unsaturated compound having a -CO- group and a -NH2, -NH- and/or -OH group, (g) is from up to about 120 parts by weight of a copolymerizable or cocurable diacrylate compound having an average molecular weight of up to about 1 500 and being at least one polyoxyalkylene glycol based oligomer having two acrylate groups, and (i) is a mixture of from about 5 to 1 5 parts by weight of conductive carbon black and from about 50 to 150 parts by weight of another filler.

11. The method which comprises in-mold coating a molded thermoset polyester resin or thermoset vinyl ester resin glass fiber composition containing from about 10 to 75% by weight of glass fibers with a thermosetting in-mold coating composition under pressure, at a temperature and for a period of time sufficient to cure said in-mold coating composition to form an adherent thermoset coating on said molded thermoset resin glass fiber composition, said in-mold coating composition comprising (a) a polymerizable oligomer selected from the group consisting of (1) a polyurethane based oligomer having at least two acrylate groups, (2) an epoxy based oligomer having at least two acrylate groups and (3) a polyester based oligomer having a plurality of internal ethylenically unsaturated groups and mixtures of the same, (b) a copolymerizable ethylenically unsaturated monomer, (c) a zinc salt of a fatty acid having at least 10 carbon atoms, (d) an accelerator for a peroxide initiator and (e) polyvinylacetate in a minor amount by weight as compared to the polymerizable materials and sufficient for paint adhesion, (f) a copolymerizable monoethylenically unsaturated compound having a -CO- group and a -NH2, -NH- and/or-OH group, (g) optionally additionally containing for partial replacement of (a) a copolymerizable liquid acrylate compound having from 2 to 4 vinyl groups, being free of urethane, cycloaliphatic and aromatic groups and having a molecular weight of up to about 1500, (h) optionally additionally containing a calcium salt of a fatty acid having at least 10 carbon atoms, (i) a filler, said ethylenically unsaturated materials being present in an amount sufficient on curing to provide a thermoset composition, and (j) containing an organic free radical peroxide initiator in an amount of up to about 5% by weight based on the weight of said ethylenically unsaturated materials.

12. The method according to claim 11 where (a) comprises an epoxy based oligomer having at least two acrylate groups.

13. The method which comprises in-mold coating a molded thermoset polyester resin or thermoset vinyl ester resin glass fiber composition containing from about 10 to 75% by weight of glass fibers with a thermosetting in-mold coating composition under pressure, at a temperature and for a period of time sufficient to cure said in-mold coating composition to form an adherent thermoset coating on said molded thermoset resin glass fiber composition, said in-mold coating composition comprising (a) 100 parts by weight of a polymerizable oligomer selected from the group consisting of (1) a polyurethane based oligomer having at least two acrylate groups, (2) an epoxy based oligomer having at least two acrylate groups and (3) a polyester based oligomer having a plurality of internal ethylenically unsaturated groups, and mixtures of the same, (b) from about 80 to 150 parts by weight of a copolymerizable ethylenicaliy unsaturated monomer, (c) from about 0.2 to 5 parts by weight of a zinc salt of a fatty acid having at least 10 carbon atoms, (d) from about 0.05 to 2 parts by weight of an accelerator for a peroxide initiator and (e) from about 40 to 80 parts by weight of polyvinylacetate, (f) up to about 1 20 parts by weight of a copolymerizable monoethylenically unsaturated compound having a -C 0-- group and a -NH2, -NH- and/or -OH group, (g) optionally additionally containing for partial replacement of (a) from about 0 to 120 parts by weight of a copolymerizable liquid acrylate compound having from 2 to 4 vinyl groups, being free of urethane, cycloaliphatic and aromatic groups and having a molecular weight of up to about 1500, (h) optionally additionally containing from about 0.2 to 5 parts by weight of a calcium salt of a fatty acid having at least 10 carbon atoms, (i) a filler comprising talc in an amount of from about 50 to 150 parts by weight and conductive carbon black in an amount of from about 5 to 1 5 parts by weight and (j) an organic free radical peroxide initiator in an amount of up to about 5% by weight based on the weight of said ethylenically unsaturated materials.

14. The method according to claim 1 3 where (a) comprises an epoxy based oligomer having at least two acrylate groups.

15. The method according to any one of claims 11 to 14 where (a) is a liquid diacrylate terminated polyesterurethane or a diacrylate ester of a liquid Bisphenol A epoxy resin, (b) is styrene, (c) is zinc stearate, (d) is cobalt octoate, (f) is hydroxy propyl methacrylate, (g) is polyoxyethylene glycol dimethacrylate having a molecular weight of about 770, (h) is calcium stearate and (i) comprises talc in an amount of from about 50 to 150 parts by weight and conductive carbon black in an amount of from about 5 to 1 5 parts by weight.

1 6. The method according to claim 1 5 where (a) is a diacrylate ester of a liquid Bisphenol A epoxy resin.

17. The method according to claim 1 5 or claim 1 6 in which said initiator is tertiary butyl perbenzoate and is used in an amount of up to about 2% by weight.

1 8. The method according to claim 11 where (a) is either (I) a mixture of said epoxy based oligomer (2) and a said polyurethane based oligomer (1), optionally partially replaced by a said copolymerizable liquid (g) or (II) a said epoxy based oligomer (2) partially replaced by a said copolymerizable liquid (g), the said copolymerizable liquid (g) being, in either alternative (I) or (II), at least one polyoxyalkylene glycol based oligomer having two acrylate groups and having a molecular weight of up to 1 500.

19. The method according to claim 11 or claim 18 where: (a) is 100 parts by weight of a polymerizable epoxy based oligomer having at least two acrylate groups, (b) is from about 80 to 1 50 parts by weight of at least one said copolymerizable ethyienically unsaturated monomer, (c) is from about 0.2 to 5 parts by weight of at least one said zinc salt of a fatty acid having at least 10 carbon atoms, (d) is from about 0.05 to 2.0 parts by weight of at least one said accelerator for a peroxide initiator, (e) is from about 40 to 80 parts by weight of the polyvinyl acetate, (f) is from up to about 120 parts by weight of at least one copolymerizable monoethylenically unsaturated compound having a -CO- group and a -NH2, -NH- and/or -OH group, (g) is from up to about 120 parts by weight of a copolymerizable or cocurable diacrylate compound having an average molecular weight of up to about 1 500 and being at least one polyoxyalkylene glycol based oligomer having two acrylate groups, and (i) is a mixture of from about 5 to 1 5 parts by weight of conductive carbon black and from about 50 to 1 50 parts by weight of another filler.

20. A composition according to any one of claims 1 to 10 substantially as any such composition herein described and exemplified.

21. A method according to any one of claims 11 to 19 substantially as any such composition herein described and exemplified.

22. A molded thermosetting resin article whenever in-mold coated with a composition according to any one of claims 1 to 10 and 20.

23. A product produced by a method according to any one of claims 11 to 19 and 21.