JPS63137933A - Coating composition and molded resin article having excellent surface characteristics and produced by coating said composition - Google Patents

Abstract

PURPOSE:To provide a coating composition composed of a monomer component containing polyvalent (meth)acrylate, etc., an organic solvent and a photo-polymerization initiator, easily curable in air when applied to a molded resin article and giving a coating film having remarkably excellent abrasion resistance and high heat resistance, solvent resistance, etc. CONSTITUTION:The objective composition is produced by compounding (A) 100pts.wt. of a monomer component composed of (i) 69.8-95wt% polyvalent (meth)acrylate having >=3 (meth)acryloyl groups, (ii) 4.8-30wt% maleimide compound of formula I (R1 is univalent alicyclic hydrocarbon group) or a cycloalkyl (meth)acrylate monomer of formula II (R2 is H or methyl; R3 is same as R1), (iii) 0.2-10wt% phosphoric acid group-containing (meth)acrylate monomer of formula III (R4 is H or methyl; R5 is H, etc.; n is 1-6) and (iv) 0-25wt% other nonvolatile polymerizable monomer (the sum of i-iv is 100wt%) with (B) 10-900pts.wt. of an organic solvent capable of dissolving the component A and (C) 0-10pts.wt. of a photo-polymerization initiator.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is easily cured even in an air atmosphere by irradiation with active energy rays, has extremely excellent scratch resistance, and has excellent heat resistance, solvent resistance, and antistatic properties. The present invention relates to a coating composition capable of forming a crosslinked film with excellent properties such as hardness, weather resistance, and adhesion to various substrates, and a resin molded article coated with the same that has excellent surface properties.

(Prior art) Resin molded products are generally used in a wide range of fields because they have various advantages such as being lightweight, having excellent impact resistance, being inexpensive, and being easy to mold. Since the surface hardness is relatively low, the surface is easily scratched by contact with other items during storage, transportation, and use. In particular, for products that require transparency and good appearance, scratches on the surface of resin molded products can significantly reduce their value and even make them unusable, so there is a strong demand for improving the scratch resistance of the surface. There is. In order to improve these drawbacks, various studies have been carried out in the past.

For example, there are methods of applying organic coating materials such as melamine resin or inorganic coating materials such as organopolysiloxane resin and curing them with heat, but both methods have problems with workability, and organic coating materials Scratch resistance was insufficient, and inorganic coating materials had drawbacks such as poor adhesion and the need for primer treatment. On the other hand, the method of applying a polyfunctional (meth)acrylate monomer to the surface of a resin molded product and irradiating it with active energy rays to form a cured film has excellent productivity and is also scratch resistant. Due to its excellent adhesiveness and adhesion, much research has been conducted on it, and some of it has even been put into practical use. The polyfunctional (meth)acrylate monomer used to form a cured film by irradiation with active energy rays should be trifunctional or higher (meth)acrylate monomer in terms of curability and scratch resistance of the resulting film. ) It is preferable to use acrylate monomers, but cured films obtained from trifunctional or higher functional (meth)acrylate monomers generally have low flexibility and poor adhesion to various substrates, so they do not last long. When used for a long period of time, the coating may crack or peel off from the base material.

Moreover, since it is inferior in heat resistance, there is a problem that the durability is further reduced especially when used at high temperatures.

Therefore, conventional coating compositions unavoidably contain monofunctional and/or difunctional (meth)acrylate monomers.
Because it is used in combination with (meth)acrylate monomers that are more functional, the balance with durability is only achieved at the expense of curing and scratch resistance, and even higher performance coatings are achieved. There is a strong desire to develop a composition for

(Problems to be Solved by the Invention) As a result of extensive research, the present inventors have found that a coating composition containing specific components in a specific ratio can be easily cured by active energy rays even in an air atmosphere. It has excellent scratch resistance, as well as heat resistance, solvent resistance, antistatic properties, weather resistance,
By forming a film with excellent adhesion to various substrates and by coating the coating assembly on a resin molded product, it is possible to create a resin molded product that can maintain excellent surface properties for a long period of time. The inventors have discovered what can be obtained and have completed the present invention.

(Means and effects for solving the problem) That is, the present invention provides polyvalent (meth)acrylate (a) having three or more (meth)acryloyloxy groups in the molecule (hereinafter, polyvalent (meth)acrylate It is called (a).>69.8~9
5% by weight, a maleimide compound (b) represented by the following general formula (I> (in the formula, R1 represents a monovalent alicyclic hydrocarbon group which may have a substituent))
and/or the following general formula (II) C1-12=C-C-0
-R3(II) (wherein, R2 is hydrogen or a methyl group, R3
represents a monovalent alicyclic hydrocarbon group which may have a substituent. ) 4.8 to 30% by weight of the cycloalkyl (meth)acrylate monomer (iii) represented by the following general formula (II
I) Phosphoric acid group-containing (meth)acrylate represented by R4R50 (wherein R4 represents hydrogen or a methyl group, R5 represents hydrogen, a methyl group, or a halogenated methyl group, and n represents an integer of 1 to 6) 0.2 to 10% by weight of the monomer (d), the polyvalent (meth)acrylate (a), the maleimide compound (b),
The cycloalkyl (meth)acrylate monomer (c)
and a substantially non-volatile polymerizable monomer (e) (g) excluding the phosphoric acid group-containing (meth)acrylate monomer (d).

Below, it is called a polymerizable monomer (e). ) 0 to 25% by weight (however, (a) + (b) + (c) + (d) + (e) is 100%
Weight%. 100 parts by weight of a monomer component (A) consisting of ) and an organic solvent (B) that can dissolve the monomer component (A).
10 to 900 parts by weight and photopolymerization initiator (C) 0 to 10
Parts by weight of a coating composition that can be cured by active energy rays to form a coating with excellent scratch resistance and durability, and a resin molded article coated with the coating composition that has excellent surface properties. This relates to resin molded products.

Polyvalent (meth)acrylate used in the present invention (
A) has good curability with active energy rays, and its cured film has excellent scratch resistance. Examples of polyvalent (meth)acrylates (a) that can be used include trimethylolethane tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, tris 2-(meth)acryloyloxyethyl isocyanurate, and glycerin tri(meth)acrylate. ) acrylate, polyol poly(meth)acrylates such as pentaerythritol tri(meth)acrylate, bemetaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate; α, ω Polyester poly(meth)acrylates such as -di(meth)acrylate-(bistrimethylolpropane)-tetrahydrophthalate, α,ω-di(meth)acrylate-(bistrimethylolpropane)-adipate; pentaerythritol tri(meth)acrylate Polyols such as poly(
Examples include reaction products of meth)acrylate and diisocyanate compounds, but pentaerythritol tetra(meth)acrylate and dipentaerythritol penta(meth)acrylate provide excellent curability and high scratch resistance. It is preferable to use a (meth)acrylate monomer having four or more functionalities, such as acrylate, dipentaerythritol hexa(meth)acrylate, and a reaction product of polyol poly(meth)acrylate and a diisocyanate compound. Pentaerythritol tri(
Most preferably, a 20-80% by weight mixture of the reaction product of a meth)acrylate and a diisocyanate compound and dipentaerythritol hexa(meth)acrylate is used: 80-20% by weight. Polyvalent (meth)acrylate (
b) is 69.8 to 9 in 100% by weight of monomer component (A)
It is used in a range of 5% by weight. Usage amount is 69.8% by weight
When not swirled, sufficient scratch resistance cannot be obtained. Also, 95
If it exceeds % by weight, the durability will be insufficient.

The maleimide compound (b) represented by the general formula (I) used in the present invention and/or the cycloalkyl (meth)acrylate monomer represented by the general formula (II) (
C) improves flexibility and heat resistance without impairing curability or scratch resistance when used in combination with the polyvalent (meth)acrylate (A).

Examples of maleimide compounds (b) that can be used include cyclopentylmaleimide, cyclohexylmaleimide,
Examples include methylene-di-4,1-SchifO hexanediyl bismaleimide.

In addition, cycloalkyl (meth)acrylate monomers (c) that can be used include cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, 1-methylcyclohexyl (meth)acrylate, and 4-t-butylcyclohexyl (meth)acrylate. , 3.3.5
-trimethylcyclohexyl (meth)acrylate, isobornyl (meth)acrylate, and the like.

These maleimide compounds (b) and cycloalkyl (meth)acrylate monomers (c) may be used alone or in combination of two or more. General formula (
The maleimide compound (b) represented by I) and/or the cycloalkyl (meth)acrylate monomer (c) represented by the general formula (I[) are the monomer components (A>100% by weight), 4. It is used in a range of 8 to 30% by weight.If this amount is less than 4.8% by weight, the flexibility and heat resistance of the coating composition will decrease, and if it exceeds 30% by weight, the scratch resistance will deteriorate. It becomes insufficient.

The phosphoric acid group-containing (meth)acrylate monomer (d) represented by the general formula (I[[) used in the present invention significantly improves the scratch resistance of the cured film and also exhibits antistatic properties. It is something. Specific examples of the phosphoric acid group-containing (meth)acrylate monomer (d) include acid phosphoxyethyl (meth)acrylate, acid phosphoxypropyl (meth)acrylate, acid phosphoxybutyl (meth)acrylate, 3 -Chloro-2
-Acid phosphoxypropyl (meth)acrylate, etc., and one or a mixture of two or more of these can be used. The amount of the phosphoric acid group-containing (meth)acrylate monomer (d) used is in the range of 0.2 to 10% by weight, preferably 1 to 5% by weight based on 100% by weight of the monomer component (A). be. If the amount used is less than 0.2% by weight, sufficient scratch resistance and antistatic properties cannot be obtained, and if it exceeds 10% by weight, an improvement in scratch resistance commensurate with the amount used cannot be expected.
On the contrary, the curing properties in an air atmosphere become insufficient.

The monomer component (A) in the present invention is a specific polyvalent (meth)
Acrylate (a), maleimide compound (b) and/or cyclohexyl (meth)acrylate monomer (c)
and phosphate group-containing (meth)acrylate monomers (
d) in the above-mentioned amounts, and each of these components is inseparable from each other and can be cured even in an air atmosphere, and is used for coatings that provide a cured film with extremely excellent scratch resistance and durability. A composition is obtained.

In the present invention, the monomer component (A) may be used in combination with a substantially non-volatile polymerizable monomer (E), if necessary, without departing from the purpose of the present invention. The term "substantially non-volatile" as used herein means that the coating composition does not volatilize during the process of coating and drying, but remains in the film as a film-forming component.

Usable polymerizable monomers (e) include, for example, vinyl compounds such as N-vinylpyrrolidone, vinylpyridine, and divinylbenzene; allyl compounds such as diallylphthalene and trimethylolpropane diallyl ether; n-butylmaleimide; , stearylmaleimide, N-7 enylmaleimide and other maleimide compounds;
Methoxyethyl (meth)acrylate, ■Toxydiethylene glycol (meth)acrylate, phenoxyethyl (meth)acrylate, and droxyethyl (meth)acrylate, 1.4-butanediol di(meth)acrylate, diethylene glycol di(meth)acrylate,
Examples include (meth)acrylates such as tripropylene glycol di(meth)acrylate, and one type or a mixture of two or more of these can be used. The amount of polymerizable monomer (E) used is 0 in 100% by weight of monomer component (A).
The range is from 0 to 25% by weight, preferably from 0 to 20% by weight. If the amount used exceeds 25% by weight, a coating composition with excellent scratch resistance and durability cannot be obtained.

Examples of the organic solvent (B) that can dissolve the monomer component (A) used in the present invention (hereinafter referred to as organic solvent (B)) include alcohols such as ethanol, isoprobanol, normal butanol, and isobutanol. Aromatic hydrocarbons such as benzene, toluene, and xylene:
Esters such as ethyl acetate, butyl acetate, amyl acetate, and ethyl lactate; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and diacetone alcohol; ethers such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve; One or a mixture of two or more of these can be used. Also,
Polymerizable monomers such as methyl acrylate, butyl acrylate, methyl methacrylate, styrene, and vinyl acetate can also be used as organic solvents (B) if they have the same effects as these organic solvents (B). You may do so. The organic solvent (B) is used to further improve the coating workability of the coating composition and the adhesion of the cured film to the substrate, and is used in an amount of 10 parts by weight per 100 parts by weight of the monomer component (A). It is used in a range of 900 parts by weight, preferably 40 to 300 parts by weight. If the amount of organic solvent (B) used is 10 parts by weight without swirling, it will be difficult to adjust the coating composition to the optimum viscosity in terms of coating workability, and conversely, if the amount of organic solvent (B) used is 10 parts by weight or less, it will be difficult to adjust the coating composition to the optimum viscosity. In this case, the control of the coating thickness becomes rotational, and the smoothness of the resulting coating decreases, which is not preferable. In addition, when using the organic solvent (B), the type and base should be selected appropriately depending on the application method, etc. However, devitrification and cracks may occur depending on the type of resin used as the base material. Therefore, you need to be careful in your selection.

In the present invention, in order to apply the coating composition to the surface of a resin molded article and form a cured film, it is necessary to irradiate the surface with active energy rays such as ultraviolet rays, electron beams, and radiation. Among these, the method of irradiating with ultraviolet rays is the most practical method because the equipment is simple and other reasons.

In order to cure by irradiating ultraviolet rays, it is necessary to add a photopolymerization initiator (C) that can initiate a polymerization reaction by irradiating ultraviolet rays. Examples of the photopolymerization initiator (C) used in the present invention include benzoin ethers such as benzoin ethyl ether and benzoin isobutyl ether; benzyl ketals such as dimethoxyphenylacetophenone and hydroxycyclohexylphenyl ketone; acetophenones such as jetoxyacetophenone; Kind:
Examples include ketones such as benzophenone, benzyl, and 2-chlorothioxanthone, and one type or a mixture of two or more of these can be used. The amount of these photopolymerization initiators (C) used is 100% of the monomer component (A).
O to 10 polymerized parts based on weight parts, preferably 0.1 to 6
Parts by weight. If the amount of the photopolymerization initiator (C) used exceeds 10 parts by weight, it is not preferable because the scratch resistance and weather resistance of the coating will decrease.

The coating composition of the present invention includes a monomer component (A), an organic solvent (
B) and a photopolymerization initiator (C) in the above-mentioned amounts, and if necessary, a known ultraviolet absorber, antioxidant, plasticizer, leveling agent, antifoaming agent, Additives such as organic or inorganic fillers and colorants can be added.

21- The resin molded article of the present invention with excellent surface properties is obtained by applying the coating composition to the surface of various resin moldings and curing it with active energy rays.

Applicable resin moldings include moldings of various resins, regardless of whether they are thermoplastic resins or thermosetting resins, such as polymethyl methacrylate resin, polystyrene resin, acrylonitrile-styrene resin, ABS resin, polycarbonate resin, and polyallyl diglycol carbonate. Resin, hard vinyl chloride resin, cellulose acetate resin, cellulose acetate butyrate resin, nylon resin, polyacetal resin, polyester resin, etc. Sheet-like molded products, film-like molded products, rond-like molded products, and the above resins and organic or inorganic Examples include composite molded products with materials such as Among these molded products, resin molded products such as polymethyl methacrylate resin and polycarbonate resin have optical properties,
It is particularly preferred because there is a strong demand for a substitute for applications in which glass has traditionally been used, taking advantage of its properties such as impact resistance, heat resistance, and weather resistance, and there is also a strong demand for improved scratch resistance. These various resin moldings may be coated with the coating composition as they are, but if necessary, pretreatment such as corona discharge, glow discharge, ozone oxidation, hydrolysis, coating with an adhesive layer, printing, etc. Resin moldings treated with can also be used.

Further, as a method for applying the coating composition to the resin molded article, commonly used methods such as brush coating, dip coating, roll coating, spray coating, flow coating, etc. can be suitably employed.

The coating amount needs to be adjusted so that the thickness of the cured coating film is in the range of 0.5 to 15 microns, preferably 1 to 10 microns. 0.
If it is thinner than 5μ, the scratch resistance will be poor, and if it exceeds 15μ, the internal strain will become large, resulting in a hardened film with poor flexibility, resulting in a decrease in the durability of the resin molded product. Undesirable.

(Effects of the Invention) The coating composition of the present invention can be easily cured even in an air atmosphere by irradiation with active energy rays, and has excellent properties such as scratch resistance, heat resistance, solvent resistance, antistatic property, weather resistance, and various substrates. Forms a crosslinked film with excellent adhesion. Therefore, the resin molded products of the present invention obtained by coating various resin molded products with the coating composition have excellent surface properties such as scratch resistance, and can maintain these surface properties for a long period of time. Glazing (windows) in the medical and electronics fields
It can be suitably used for applications such as wall materials, floor materials, cases, equipment for clean rooms, precision equipment covers, lighting covers, nameplates, transparent plates for displays, dryers, carry boxes, etc.

(Examples) Hereinafter, embodiments of the present invention will be described in detail with reference to Examples, but the present invention is not limited to the following Examples. In addition, evaluation in Examples was performed by the following method.

(1) Curing property: Under air atmosphere, high pressure mercury lamp (Iwasaki Electric ■
The curing time was measured when UV rays of UV rays of HO3-L31), manufactured by Co., Ltd., were irradiated from a distance of 10 cm.

0 Cured in less than 2 seconds × Cured in 2 seconds or more (2) Scratch resistance: Abrasion resistance tester (Shikushi Seiki Seisakusho Co., Ltd.)
#000 steel wool was made to reciprocate 100 times under a load of 500 g using a haze meter (NPH-1001DP, manufactured by Nihon Heavy Industries Co., Ltd.).

Diffuse light transmittance Haze value (%) 0 Total light transmittance X100◎ Haze value 0.
Less than 4 0 0.5 or more and less than 2 Δ 2 or more and less than 20 × 20 or more (3) Adhesion: Cut 10 x 10 squares at intervals of one shoe on the surface of the test piece with a cutter knife, and press polyester adhesive tape. After that, it was peeled off and the residual rate of the cured film was observed.

△ 51/100 to 99/100 X O/100 to 50/100 (4) Heat resistance = Appearance, scratch resistance,
Comprehensive evaluation was made in terms of flexibility and adhesion.

O There was almost no change from the film before heat treatment × There was a significant change compared to the film before heat treatment (5) Cigarette ash adhesion test ○ After rubbing the surface of the cured film 20 times with a cotton cloth, a new cigarette There is no ash attached at all even when you get it close to about 1 cm from the ash.

8) A slight amount of adhesion occurs due to the same operation as above.

× It adheres significantly during the same operation as above.

(6) Surface resistivity The surface resistivity of a 40×40 mm test piece was measured using a surface resistance measuring device (manufactured by Toa Denpa Kogyo Co., Ltd., 5lvl-10E). (Temperature 20'C Humidity 60%) Reference Example 1 Pentaerythritol 500
g, acrylic acid 875y1p-toluenesulfonic acid 7o
g, hydroquinone 0.175 g and n-hexane 5
30 g was added, and the mixture was heated and stirred while blowing 1.5 fJ/hr of air into the reaction mixture, and the water produced by the reaction was taken out of the reaction system.

After 6 hours of reaction, the reaction mixture was cooled to room temperature and separated into two layers, the n-hexane layer was removed, and the ester layer was diluted with trichlorethylene to a concentration of about 50%. Next, it was neutralized with a 5% aqueous sodium hydroxide solution containing 10% sodium chloride, and further washed successively with 600 d of a 0.5% aqueous sodium hydroxide solution containing 10% sodium chloride and 600 d of a 5% aqueous sodium chloride solution. The ester solution containing the solvent was prepared under reduced pressure (ultimate vacuum level 5 rrm).
Hg), and the solvent was distilled off at 50°C. Ester yield is 9
The composition (according to gas chromatography) was 54% pentaerythritol triacrylate, and the viscosity (B-type viscometer) was 70C1)S/25°C.

Reference Example 2 314 g of pentaerythritol triacrylate obtained in Reference Example 1 (Of-1 base weight 1, 0 mo
1), 0.42 g of dibdeltin dilaurate was added, and the mixture was stirred while blowing dry air from the fresh mother. Next, 42 g of hexamethylene diisocyanate (NGO group weight 0.5
0 mole) was added from the dropping funnel over 1 hour. After addition, the temperature was raised to 80°C for 2 hours at 40-50°C and reacted for 7 hours, after which it was taken out and was transparent with a viscosity of 4850.
C1) S/25°C liquid product (1) was obtained.

Examples 1 to 6 and Comparative Examples 1 to 5 A coating composition was prepared using the reaction product (1) obtained in Reference Example 2 according to the formulation shown in Table 1, and a polycarbonate molded plate with a thickness of 3 mm was prepared. (Nippon Shokubai Kagaku Kogyo Co., Ltd., Evocarbo) was coated uniformly using a bar coater. After leaving the solvent in a hot air dryer at 60°C for 3 minutes to volatilize the solvent, the ultraviolet rays from a high-pressure mercury lamp (manufactured by Iwasaki Electric, L-103-131) were irradiated for 6 seconds from a distance of 1 cm to form a layer with a thickness of 3 cm. A resin molded article with a cured film of ~4 μm size formed on the surface was obtained. The performance of these resin molded products was as shown in Table 3.

Examples 7 to 9 and Comparative Example 6 Using the reaction product (1) obtained in Reference Example 2, a coating composition was prepared according to the formulation shown in Table 1, and a 3# thick methacrylic resin plate (Mitsubishi Rayon Co., Ltd., Acrylite) was coated uniformly using a bar coater. After leaving the solvent in a hot air dryer at 60°C for 3 minutes to evaporate the solvent, apply ultraviolet rays from a high-pressure mercury lamp (manufactured by Iwasaki Electric Co., Ltd., HO2-131) to 10 cm.
A resin molded article was obtained by irradiating the resin for 6 seconds from a distance of 3 to 4 μm thick on the surface of the cured film. The performance of these resin molded products was as shown in Table 3.

Table ■ As is clear from Table ■ and Table ■, only when the composition satisfies the conditions of the coating composition of the present invention, the coating composition has excellent curability and good scratch resistance and durability. A resin molded article was obtained, which had overlapping layers.

(*1) DP) IA Dipentaerythri 1-
monolhexaacrylate (*2) TMPTA t-limethylolpropane triacrylate (*3) CHMI cyclohexylmaleimide (*4) T-BuCHA t-butylcyclohexyl acrylate (*5) 1.4-BODA 1.4 -Butanediol diacrylate (*6) AREA Acid phosphoxyethyl acrylate (*7) Organic solvent Ethyl cellosolve: Isopropyl acrylate 100:30 mixture (*8) Photopolymerization initiator Irgacure #651 (CI
(*9) Leveling agent FC-430 (manufactured by Sumitomo 3M Co., Ltd.)

Claims (1)

[Claims] 1. Polyvalent (meth)acrylate (a) having 3 or more (meth)acryloyloxy groups in the molecule 69.8-95
Weight%, the following general formula (I) ▲Mathematical formulas, chemical formulas, tables, etc. are available▼(I) (In the formula, R_1 represents a monovalent alicyclic hydrocarbon group that may have a substituent.) Maleimide compound represented by (b) and/or the following general formula (II) ▲ Numerical formula, chemical formula, table, etc. ▼ (II) (In the formula, R_2 is hydrogen or a methyl group, and R_3 may have a substituent. A cycloalkyl (meth)acrylate monomer (indicates a monovalent alicyclic hydrocarbon group)
C) 4.8 to 30% by weight, General formula (III) below ▲ Numerical formulas, chemical formulas, tables, etc. are available ▼ (III) (In the formula, R_4 is hydrogen or a methyl group, R_5 is hydrogen, a methyl group, or a methyl halide 0.2 to 10% by weight of the phosphoric acid group-containing (meth)acrylate monomer (d), and n is an integer of 1 to 6; ), substantially non-volatile polymerization excluding the maleimide compound (b), the cycloalkyl (meth)acrylate monomer (c), and the phosphoric acid group-containing (meth)acrylate monomer (d) Polymer monomer (e) 0 to 25% by weight (however, (a) + (b) + (
c) + (d) + (e) is 100% by weight. ), 100 parts by weight of a monomer component (A), and 10 to 10 parts of an organic solvent (B) that can dissolve the monomer component (A).
A coating composition comprising 900 parts by weight and 0 to 10 parts by weight of a photopolymerization initiator (C), which can be cured by active energy ray irradiation to form a coating with excellent scratch resistance and durability. 2. Polyvalent (meth)acrylate (a) having three or more (meth)acryloyloxy groups in the molecule is a reaction product of pentaerythritol tri(meth)acrylate and a diisocyanate compound, 20 to 80% by weight, and dipentaerythritol. The coating composition according to claim 1, which is a mixture with 80 to 20% by weight of hexa(meth)acrylate. 3. The amount of photopolymerization initiator (C) used is 1 of the monomer component (A)
The coating composition 4 according to claim 1 or 2, wherein the active energy ray is ultraviolet rays, and the (meth)acryloyloxy group in the molecule is 0.01 to 10 parts by weight per 00 parts by weight. 69.8 to 95% by weight of polyvalent (meth)acrylate (a) having 3 or more of Maleimide compounds (b) represented by the following formula (II) ▲ Numerical formulas, chemical formulas, tables, etc. ▼ (II) In the formula, R_2 is hydrogen or a methyl group, and R_3 is a monovalent alicyclic hydrocarbon group which may have a substituent.) A cycloalkyl (meth)acrylate monomer (
C) 4.8 to 30% by weight, General formula (III) below ▲ Numerical formulas, chemical formulas, tables, etc. are available ▼ (III) (In the formula, R_4 is hydrogen or a methyl group, R_5 is hydrogen, a methyl group, or a methyl halide 0.2 to 10% by weight of the phosphoric acid group-containing (meth)acrylate monomer (d), and n is an integer of 1 to 6; ), substantially non-volatile polymerization excluding the maleimide compound (b), the cycloalkyl (meth)acrylate monomer (c), and the phosphoric acid group-containing (meth)acrylate monomer (d) Polymer monomer (e) 0 to 25% by weight (however, (a) + (b) + (
c) + (d) + (e) is 100% by weight. ), 100 parts by weight of a monomer component (A), and 10 to 10 parts of an organic solvent (B) that can dissolve the monomer component (A).
A resin molded article with excellent surface properties, obtained by applying a coating composition consisting of 900 parts by weight and 0 to 10 parts by weight of a photopolymerization initiator (C) to a resin molded article and curing it with active energy rays. 5. Polyvalent (meth)acrylate (a) having three or more (meth)acryloyloxy groups in the molecule is a reaction product of pentaerythritol tri(meth)acrylate and a diisocyanate compound, 20 to 80% by weight, and dipentaerythritol. The resin molded article according to claim 4, which is a mixture with 80 to 20% by weight of hexa(meth)acrylate. 6. The amount of photopolymerization initiator (C) used is 1 of the monomer component (A)
The resin molded article according to claim 4 or 5, wherein the active energy ray is ultraviolet rays. 7. The resin molded article according to claim 4, 5 or 6, wherein the resin molded article is a molded article of polymethyl methacrylate resin or polycarbonate resin.