JPH0710942A - Thermosetting resin composition for in-mold coating - Google Patents

Abstract

PURPOSE:To obtain a resin composition which produces a coating layer excellent in appearance such as gloss, quality and adhesion to molding materials in in- mold coating by incorporating respectively specific thermostting resin and finely divided powder of the cured product. CONSTITUTION:This resin composition comprises one or more thermosetting resins selected from unsaturated polyester resins, urethane acrylate resins and epoxy acrylate resins (e.g. an unsaturated polyester resin prepared from maleic anhydride, isophthalic acid and propylene glycol) and a finely divided powder of the cured product of one or more of the thermosetting resins.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a coating material in a so-called in-mold coating molding method in which a thermosetting coating material is coated and cured on a thermosetting molding material in a molding die to form a coating layer. The present invention relates to a thermosetting resin composition for in-mold coating molding used as.

[0002]

2. Description of the Related Art Recently, molded articles made of thermosetting material have
It is very widely used in industrial parts as a substitute for metal parts. Above all, a sheet molding compound (hereinafter abbreviated as SMC) or a bulk molding compound (hereinafter abbreviated as BMC) is generally used. However, in a molded product obtained by molding SMC or BMC by heating and pressing in a molding die, surface defects such as pores, microcracks, sink marks or undulations tend to occur on the surface. When such surface defects are present, it is difficult to form a sufficient coating film even if the molded product is coated by a usual method.

Therefore, a so-called in-mold coating molding method has been proposed as a method for concealing the above-mentioned surface defects. For example, Japanese Examined Patent Publication No. 4-33252 discloses a method of forming a coating layer on a molding material by injecting the coating material at an injection pressure higher than the molding pressure and curing it during compression molding. Further, as the thermosetting resin composition for in-mold coating molding used in these molding methods, for example, in JP-A-1-126316, a mold containing urethane acrylate and epoxy acrylate as main components and an inorganic filler is used. Inner coating compositions are disclosed.

[0004]

However, the coating film coated by such in-mold coating composition using such a usual in-mold coating composition has a drawback that it has no gloss and is inferior in appearance quality. The present inventors have found that the reason why the appearance quality of such a coating is inferior is due to the contained inorganic filler. When an in-mold coating composition that does not use an inorganic filler is prepared and in-mold coating molding is performed, the adhesion between the coating film and the molding material deteriorates because the shrinkage rate of the thermosetting resin composition is large. It has drawbacks. The present invention is to improve the above-mentioned drawbacks, and in an in-mold coating molding method, an in-mold method for producing a coated article having gloss and excellent appearance quality and good adhesion with a molding material is also provided. An object is to provide a thermosetting resin composition for coating molding.

[0005]

The thermosetting resin composition for in-mold coating molding of the present invention comprises at least one thermosetting resin selected from unsaturated polyester resin, urethane acrylate resin and epoxy acrylate resin, and At least one kind of pulverized powder of a cured product of the thermosetting resin is contained, whereby the above object is achieved. Hereinafter, the present invention will be described in detail.

As the resin used as the thermosetting resin in the thermosetting resin composition for in-mold coating of the present invention, at least one kind of unsaturated polyester resin, epoxy acrylate resin and urethane acrylate resin is used. . These resins may be used alone or as a mixture of plural kinds.

The hardened product pulverized powder of the thermosetting resin used in the present invention means a thermosetting resin composed of at least one of unsaturated polyester resin, epoxy acrylate resin and urethane acrylate resin, It is pulverized into a fine powder.

As a method for curing the thermosetting resin,
Any conventionally known method is used. For example, a method of allowing a catalyst such as an organic peroxide to be poured into a mold and heating and curing, a method of containing a photoinitiator and causing a curing reaction by ultraviolet rays or the like in a mold and a container, There is a method of causing a curing reaction with an electron beam.

Examples of the organic peroxide include methyl ethyl ketone peroxide, tertiary butyl peroxobenzoate, tertiary butyl peroxoisopropyl carbonate, benzoyl peroxide,
There are dicumyl peroxide, tertiary butyl peroxy-2-ethylhexanoate, and the like, and examples of the photoinitiator include 1-phenyl-2-hydroxy-2-
Examples include methylpropan-1-one, hydroxy-cyclohexyloxy-phenylketone, dimethylbenzyl ketal, acylophosphine oxide and the like.

The hardened product thus obtained is finely crushed (for example, the roughly crushed hardened product is placed in a mortar-like container and finely crushed by rotating a rotary blade while cooling with liquid nitrogen or the like). The fine powder thus obtained is blended, and its size is preferably about 1 to 100 microns in average particle size, and more preferably 5 to 60 microns. If the size of the cured product is too large, the resulting molded article tends to have a reduced gloss, and if it is too small, the crushing cost is high.

The content of the cured product used in the thermosetting resin composition for in-mold coating molding of the present invention is 100 parts by weight of the resin component (total amount of thermosetting resin, thermoplastic resin and copolymerizable monomer). The amount is preferably 3 to 150 parts by weight, and more preferably 10 to 100 parts by weight. If the amount of the cured product used is too small, it is difficult to obtain sufficient adhesion between the coating and the molding material, and if it is too large, the viscosity becomes too high and the fluidity in the mold decreases. However, it has a drawback that it is difficult to spread the molding material over the entire surface.

Here, as the urethane acrylate resin, a conventionally known and conventional one is used. For example, it is produced by reacting an organic polyol such as an alkylene diol, an alkylene diol ester, an alkylene diol ether, a polyether polyol or a polyester polyol with an organic polyisocyanate, and further reacting with a hydroxyalkyl (meth) acrylate.

The above-mentioned unsaturated polyester resin is usually produced by a known and commonly used method, usually an organic polyol, an aliphatic unsaturated polycarboxylic acid, and if necessary, an aliphatic saturated polycarboxylic acid and / or an aromatic polycarboxylic acid. Manufactured from.

On the other hand, the above-mentioned epoxy acrylate resin is usually a reaction product of an epoxy resin and a monocarboxylic acid having a reactive double bond such as (meth) acrylic acid, and a polymerizable unsaturated monomer such as styrene or diallyl phthalate. The one dissolved in the polymer is used.

Here, examples of the above-mentioned organic polyol include diols, triols, tetraols and mixtures thereof, and they are mainly divided into aliphatic polyols and aromatic polyols, of which typical ones are aliphatic polyols. Includes ethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, triethylene glycol, neopentyl glycol, dibromoneopentyl glycol, hexamethylene glycol, trimethylene glycol, trimethylolpropane, glycerin, pentaerythritol diallyl ether, Hydrogenated bisphenol A and the like, and typical aromatic polyols are bisphenol A or bisphenol S or these bisphenol A or Ethylene oxide scan phenol S, an aliphatic oxirane compounds such as propylene oxide or butylene oxide, the average in one molecule 1-2
There are polyoxyalkylene bisphenol A, polyoxyalkylene bisphenol S, etc. obtained by adding in the range of 0.

Further, as the above-mentioned aliphatic unsaturated carboxylic acid, (anhydrous) maleic acid, fumaric acid, (anhydrous) itaconic acid, etc. are used, and as the above-mentioned aliphatic saturated carboxylic acid, sebacic acid, adipic acid, (anhydrous) Examples of the aromatic carboxylic acid such as succinic acid include (anhydrous) phthalic acid, isophthalic acid, terephthalic acid, methyltetrahydrophthalic anhydride,
Endomethylene tetrahydrophthalic anhydride or the like is used.

As the epoxy resin used for the above epoxy acrylate resin, epichlorohydrin and bisphenol A can also be prepared by known methods.
From bisphenol A type epoxy resin, epichlorohydrin and brominated bisphenol A, brominated bisphenol A type epoxy resin, novolak type epoxy resin produced by glycidyl etherification of phenol novolac or orthocresol novolak, and various amines Tetraglycidyl metaxylenediamine, tetraglycidyl 1.3-bisaminomethylcyclohexane, tetraglycidyl diaminodiphenylmethane, triglycidyl-p-aminophenol, triglycidyl-obtained by reacting epichlorohydrin
Glycidyl amine compounds such as m-aminophenol, diglycidyl aniline and diglycidyl orthotoluidine are used.

As the polyol used for the urethane acrylate resin, alkylene diols such as ethylene glycol, propylene glycol,
Diethylene glycol, diisopropylene glycol,
Polyethylene glycol, polypropylene glycol,
Polyoxymethylene, polyethylene oxide, polypropylene oxide, etc. as polyether polyols such as hydroxyalkyl ethers of butanediol, polyesters having hydroxyl groups at both ends manufactured by the above-mentioned organic polyols and polycarboxylic acids as polyester polyols. A polyol or the like is used.

As the polyisocyanate used for the urethane acrylate resin, tolylene diisocyanate, isophorone diisocyanate, polymethylene polyphenyl diisocyanate and the like are used.

The hydroxyalkyl (meth) acrylate used in the urethane acrylate resin is usually hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate or the like, and the hydroxyl group is usually It is bonded to the beta carbon of the alkyl group.
Alkyl groups can usually contain up to 8 carbon atoms.

Further, the thermosetting resin composition of the present invention, and
The thermosetting resin composition, which is a raw material for obtaining a cured product, includes, as a low-shrinking agent, polyvinyl acetate, polymethyl (meth) acrylate, polyethylene, ethylene vinyl acetate copolymer, vinyl acetate-styrene copolymer, polybutadiene,
Thermoplastic resins such as saturated polyesters and saturated polyethers can be used in an appropriate amount as needed.

Further, the thermosetting resin composition of the present invention, and
An appropriate amount of inorganic filler can be added to the thermosetting resin composition, which is a raw material for obtaining a cured product, depending on the purpose and application. Examples of usable inorganic fillers are as follows. That is, elemental minerals such as graphite and diamond, halogenated minerals such as rock salt and potassium rock salt,
Carbonate minerals such as calcium carbonate, phosphate minerals such as cyanite, vanadate minerals such as carnotite, barite (barium sulfate), sulfate minerals such as gypsum (calcium sulfate), and boric acid such as borax. Salt minerals, titanate minerals such as perovskite, mica, talc, pyrophyllite, kaolin, quartz, silicate minerals such as feldspar, titanium oxide,
Natural or artificial minerals centering on steel balls (aluminum oxide), metal (hydr) oxides such as aluminum hydroxide, glass products such as (hollow) glass spheres, or processed, purified or processed minerals, and A mixture of them is used.

If desired, a suitable amount of a color pigment may be used in the thermosetting resin composition of the present invention or the thermosetting resin composition as a raw material for obtaining a cured product. A conventionally known pigment is used as the color pigment. For example,
Titanium oxide, benzine yellow, anthraquinone yellow, titanium yellow, Hansa yellow, molybdate orange, yellow lead, disazo yellow, benzine orange,
Quinacridone red, quinacridone magenta, naphthol violet, chrome green, phthalocyanine green, alkali blue, cobalt blue, phthalocyanine blue, iron oxide (red iron oxide), copper azo brown, aniline black, carbon black, iron black, etc. Used.

The addition amount of the above-mentioned inorganic filler and color pigment used in the thermosetting resin composition of the present invention is 100 (resin component (total amount of thermosetting resin, thermoplastic resin, copolymerizable monomer)). It is preferable to add 0 to 30 parts by weight as a total amount of the color pigment and the inorganic filler with respect to parts by weight. If the amount of addition exceeds 30 parts, there is a drawback that the appearance such as gloss of the coating is deteriorated due to the effect that the inorganic filler is cued to the surface of the obtained coating.

Further, the addition amount of the above-mentioned inorganic filler and coloring pigment used in the thermosetting resin composition which is a raw material for obtaining a cured product is the resin component (thermosetting resin, thermoplastic resin, copolymerizable monomer). (Total amount) 100 parts by weight of color pigment,
It is preferable to add 0 to 50 parts by weight as a total amount of the inorganic filler. When the addition amount exceeds 50 parts, the resulting cured product has a drawback that the dispersibility in a thermosetting resin is lowered and the appearance such as gloss of the coating is lowered.

Further, in the thermosetting resin composition of the present invention and the thermosetting resin composition as a raw material for obtaining a cured product, various reinforcing fibers, that is, glass fiber, carbon fiber, etc. are used as a reinforcing agent as required. An appropriate amount can be added.

Further, in the thermosetting resin composition of the present invention and the thermosetting resin composition as a raw material for obtaining a cured product, styrene, alphamethylstyrene, divinylbenzene, vinyltoluene, diallylphthalate may be added, if necessary. ,
Copolymerizable monomers such as various acrylate monomers and various methacrylate monomers can be added in appropriate amounts as necessary.

Further, in the thermosetting resin composition of the present invention and the thermosetting resin composition as a raw material for obtaining a cured product, ketone peroxides, diacyl peroxides, hydroperoxides, Known initiators such as dialkyl peroxides, alkyl peresters, percarbonates, peroxyketals, known curing accelerators such as dimethylaniline and cobalt naphthenate, polymerization inhibitors such as parabenzoquinone, carbon black and Titanium oxide, iron oxide, cyanine pigments, aluminum flakes, nickel powder, gold powder, silver powder and other pigments, azo dyes and anthraquinone dyes, indigoid dyes, stilbene dyes, etc., conductivity enhancers,
An appropriate amount of an emulsifier, a metal soap such as zinc stearate, a release agent such as an aliphatic phosphate, and lecithin can be added depending on the use and purpose.

The in-mold coating composition of the present invention can be obtained by using various compounding materials as described above. Specifically, for example, a styrene solution of epoxy acrylate resin, unsaturated polyester resin, urethane acrylate resin (same as A resin is often used, but a mixture of different types of resins may be used. Styrene concentration of 40 to 70%) 60 to 100 parts of a styrene solution of a thermoplastic resin such as polymethylmethacrylate, polystyrene, or polyvinyl acetate ( Styrene concentration 30 to 80%) Add 0 to 30 parts to make 100 parts, finely pulverized powder of epoxy acrylate resin, unsaturated polyester resin, urethane acrylate resin 10-100
Parts, color pigments such as titanium oxide, iron oxide, carbon black and titanium yellow 0 to 5 parts, filler powders such as calcium carbonate and aluminum hydroxide 0 to 20 parts, organic peroxides as an initiator 0.1 to What added 5 parts is used suitably.

The thermosetting resin composition used as the thermosetting molding material in the present invention includes unsaturated polyester resin, epoxy acrylate (vinyl ester) resin, urethane acrylate resin, etc. Various fillers, reinforcing agents, additives and the like can be added according to the
It can be used as a thermosetting resin composition having a form such as C or BMC.

More specifically, for example, 0 to 30 parts of a styrene solution (styrene concentration of about 30 to 60%) is added to 70 to 100 parts by weight of an unsaturated polyester resin liquid (styrene concentration of 30 to 60%). 100 parts by weight, 100 to 300 parts of filler such as calcium carbonate, aluminum hydroxide and glass powder, 0.5 to 3 parts of organic peroxide such as tert-butyl peroxobenzoate, thickener such as magnesium oxide. 0.5 to 3 parts, and 0.5 to 5 parts of a release agent such as zinc stearate are kneaded and impregnated with 10 to 100 parts of a reinforcing agent such as glass fiber to obtain SMC or B.
Those in the form of MC are preferably used.

The in-mold coating composition and molding material thus obtained can be used for conventionally known in-mold coating molding. For example, SMC is put in a molding die heated to 130 to 160 ° C. and pressure-molded at a pressure of 40 to 120 kg / cm ² for 30 seconds to 5 minutes, and then the mold is slightly opened to form an in-mold coating composition. Injection, then 5-120 kg / c
m ^2, by applying reheating recompression 30 seconds to 5 minutes at 130 to 160 ° C., was spread a mold coating composition to the entire surface of the molded SMC, there is a method to form a film by curing .

It is also disclosed in Japanese Patent Publication No. 4-33252.
So that SMC at 130-160 ° C, 40-120k
g / cm²After pressure molding for several tens of seconds to several minutes, the pressure is adjusted to 10
~ 30 kg / cm²Use a high-pressure injection machine with the pressure reduced to
100-300 kg / cm ²High pressure of coating material in the mold
And inject again into 30 to 100 kg / cm²Increase the pressure to within the mold
There is also a method of spreading-curing the coating composition.
The thermosetting resin composition of the present invention is used for the in-mold coating method of
Can easily form a coating with good appearance quality and good adhesion.
You can

[0034]

In the conventional in-mold coating composition, an inorganic filler has been added in order to secure the adhesion of the coating film. In this case, the refractive index of the inorganic filler and the thermosetting resin is increased. However, there is a drawback that the appearance such as gloss is deteriorated by adding the inorganic filler due to the difference in the composition or the poor dispersibility.

However, since the hardened product pulverized powder of the thermosetting resin composition contained in the thermosetting resin composition of the present invention has a composition very similar to that of the thermosetting resin, the thermosetting resin The physical properties such as the refractive index are very close to those of the resin, and the dispersibility is also very good. As a result, the appearance of the resulting coating is not deteriorated by the addition of the cured product, and the appearance such as gloss is good. Will be things. Moreover, since the cured product does not cause curing shrinkage when the thermosetting resin composition undergoes a curing reaction, the shrinkage rate of the thermosetting resin composition is low due to the addition of the finely divided powder of the cured product. , Which prevents the generation of shrinkage stress at the interface between the coating and the molding material,
The adhesion of the coating becomes good.

[0036]

EXAMPLES Examples of the present invention will be described below. [Production of in-mold coating composition] The following materials were used as compounding materials. 1) Unsaturated Polyester Resin Liquid Isophthalic acid (manufactured by Wako Pure Chemical Industries, Ltd.), maleic anhydride (manufactured by Wako Pure Chemical Industries, Ltd.), and propylene glycol (manufactured by Wako Pure Chemical Industries, Ltd.) are known and commonly used methods. Was reacted to synthesize an unsaturated polyester resin and dissolved in styrene. (Hereinafter, abbreviated as UP. Molar ratio of isophthalic acid / maleic anhydride / propylene glycol = 6:
4:10, average molecular weight about 2000, styrene concentration in resin liquid about 40% by weight)

2) Epoxy acrylate resin liquid A bisphenol A type epoxy resin was converted into a methacrylic acid ester by a known and conventional method to obtain an epoxy acrylate resin, which was dissolved in styrene (hereinafter referred to as EAc, average molecular weight of about 600, resin). Styrene concentration in the liquid is about 4
0% by weight).

3) Urethane acrylate resin liquid polypropylene glycol (manufactured by Wako Pure Chemical Industries, Ltd.,
Using an average molecular weight of about 1000), tolylene diisocyanate (manufactured by Wako Pure Chemical Industries, Ltd.) and 2-hydroxyethyl methacrylate (manufactured by Wako Pure Chemical Industries, Ltd.), a urethane acrylate resin was synthesized by a known and conventional method to give styrene. Dissolved (hereinafter, abbreviated as UAc, average molecular weight about 1600, styrene concentration in resin solution about 40% by weight)

4) Cured Product 1 100 parts by weight of the above unsaturated polyester resin liquid was mixed with organic peroxide (bis (4-tert-butylcyclohexyl) peroxodicarbonate, Perkadox 16,
1 part of Kayaku Akzo Co., Ltd.) was added, and the mixture was allowed to stand in a thermostatic chamber at 60 ° C. for 2 hours for curing, and then pulverized to give a powder having an average particle size of about 50 μm. (Hereinafter, it is abbreviated as the cured product 1.). 5) Cured product 2 100 parts by weight of the above epoxy acrylate resin liquid was mixed with an organic peroxide (bis (4-tert-butylcyclohexyl) peroxodicarbonate, Perkadox 16,
1 part of Kayaku Akzo Co., Ltd.) was added, and the mixture was allowed to stand in a thermostatic chamber at 60 ° C. for 2 hours for curing, and then pulverized to give a powder having an average particle size of about 50 μm. (Hereinafter, it is abbreviated as the cured product 2.).

6) Cured product 3 100 parts by weight of the urethane acrylate resin liquid was added to an organic peroxide (bis (4-tert-butylcyclohexyl) peroxodicarbonate, Perkadox 16,
1 part of Kayaku Akzo Co., Ltd.) was added, and the mixture was allowed to stand in a thermostatic chamber at 60 ° C. for 2 hours for curing, and then pulverized to give a powder having an average particle size of about 50 μm. (Hereinafter, it is abbreviated as the cured product 3.). 7) Cured product 4 50 parts by weight of the epoxy acrylate resin liquid and 50 parts by weight of the urethane acrylate resin liquid are mixed with organic peroxide (bis (4-tert-butylcyclohexyl) peroxodicarbonate, Perkadox 16, Kayaku Akzo). 1 part), calcium carbonate (NS-100, Nitto Koka Co., Ltd.) 10 parts, and yellow pigment (yellow 9121, Dainichiseika Co., Ltd.) 2 parts were added, and the mixture was allowed to stand in a thermostatic chamber at 60 ° C. for 2 hours. After curing, it was pulverized into a powder having an average particle size of about 50 microns. (Hereinafter, it is abbreviated as the cured product 4.).

8) Titanium yellow (yellow 9121,
Dainichiseika Co., Ltd., yellow pigment) 9) Calcium carbonate (NS-100, Nitto Powder Co., Ltd.) 10) Curing agent (Kayabutyl B, Kayaku Akzo Co., Ltd.)

These were mixed and sufficiently stirred according to the following formulation table to uniformly disperse the pigment, and then allowed to stand at room temperature for 1 day to obtain an in-mold coating composition.

[Preparation of molding material] As the compounding material, the following materials were used. 1. 70 parts of unsaturated polyester resin liquid (hydrogenated bisphenol-based unsaturated polyester resin dissolved in about 40% by weight of styrene monomer) Polystyrene low-shrinking agent resin (about 30% by weight of polystyrene resin dissolved in about 70% by weight of styrene monomer) 30 parts 3. 120 parts of calcium carbonate powder (NS-100: manufactured by Nitto Koka Co., Ltd.) 4. Hardener (Kayabutyl B: Kayaku Akzo Co., tertiary butyl peroxobenzoate content 98 wt%) 1
Part 5. Thickener (magnesium oxide powder, Kyowamag 15)
0: manufactured by Kyowa Chemical Industry Co., Ltd.) 1. 6. Internal release agent (zinc stearate: manufactured by Sakai Chemical Industry Co., Ltd.) 3 parts The above materials are mixed and sufficiently stirred, and then by an SMC impregnating device. 60 parts of glass fiber (Roving made by Asahi Fiber Glass Co., Ltd .: ER4630LBD166W cut into a length of 25 mm) was impregnated with 60 parts to obtain SMC.

[Molding method] The SM thus obtained
C and the in-mold coating composition were molded as follows. Thirty
A mold for forming a square flat plate molded product of cm × 30 cm was prepared. After heating the upper mold to 150 ° C. and the lower mold to 150 ° C., charging about 700 g of the SMC, and press-molding at a pressure of 100 kg / cm ² (corresponding to a thickness of about 4 mm) for 100 seconds. , Open the mold slightly, inject 10 ml of the above-mentioned in-mold coating composition, further tighten the mold, and
The in-mold coating composition was spread on the surface of the molded SMC by reheating and repressurizing at a pressure of 00 kg / cm ² for 120 seconds, and was cured to form a film. After that, the mold was opened and the mold was removed to obtain a coated molded product.

[Evaluation Method] Using the cutter knife, a straight line reaching 11 substrates at 2 mm intervals was drawn on the surface of the thus obtained molded product, and further 11 straight lines were drawn. Adhesive tape (Cellotape, manufactured by Sekisui Chemical Co., Ltd.) was attached to the grid-shaped portion and then peeled off, and the number of remaining grids of the grid was examined (grid adhesion test). Further, the gloss of the surface of the coating film of the molded product was measured by a gloss meter (Gloss Checker IG300, manufactured by Horiba Ltd.).

(Examples 1 to 6) According to Table 1, the coating material was produced by the above-mentioned method, and the results of molding and evaluation are shown in Table 1. It was possible to obtain a coating having good color appearance and adhesion. (Comparative Examples 1 and 2) In accordance with Table 2, the coating material was manufactured by the above-mentioned method, and the results of molding and evaluation are shown in Table 2. The appearance was good, but the adhesion was poor. (Comparative Examples 3 to 4) In accordance with Table 2, the coating material was manufactured by the above-mentioned method, and the molding and evaluation results were shown in Table 2. The adhesion was good, but the appearance was poor.

[0047]

[Table 1]

[0048]

[Table 2]

[0049]

EFFECTS OF THE INVENTION The hardened material pulverized powder of the thermosetting resin composition contained in the thermosetting resin composition of the present invention has a composition very similar to that of the thermosetting resin. The dispersibility in the thermosetting resin composition is better than that of the system in which the inorganic filler is added, and the physical properties such as the refractive index are similar.
As a result, in the obtained coating, the appearance deterioration such as when the inorganic filler is added does not occur, and the appearance such as gloss becomes very good. And, since the cured product does not cause curing shrinkage when the thermosetting resin composition undergoes a curing reaction,
By adding the finely pulverized product of the cured product, the shrinkage rate of the thermosetting resin composition becomes low, which prevents the generation of shrinkage stress at the interface between the coating and the molding material, and improves the adhesion of the coating. It will be good.

Claims (1)

[Claims] 1. A thermosetting resin composition used as a coating material in in-mold coating molding, wherein a thermosetting coating material is coated and cured on a thermosetting molding material in a molding die to form a coating layer. And containing at least one thermosetting resin of an unsaturated polyester resin, a urethane acrylate resin, and an epoxy acrylate resin, and at least one kind of hardened material pulverized powder of the thermosetting resin. A thermosetting resin composition for in-mold coating molding, which is characterized.