JPS63168419A - Coating composition and synthetic resin molding coated therewith - Google Patents

Abstract

PURPOSE:To obtain the title composition which, when applied to the surface of a resin and irradiated with an radiation, can give thereto a high-hardness film excellent in adhesion and flexibility, by adding a light stabilizer having a cyclic hindered amine structure and an antioxidant to a specified acrylate mixture. CONSTITUTION:The title composition prepared by adding 0.01-5pts.wt. at least one light stabilizer having a cyclic hindered amine structure and 0.01-5pts. wt. at least one antioxidant to 100pts.wt. acrylate mixture comprising 20-75pts. wt. polyfunctional monomer derived by substituting acryloyloxy groups for at least three OH groups of a polyalcohol having at least four OH groups in the molecule, 10-60pts.wt. polyfunctional polyester acrylate obtained by coesterifying dipentaerythritol or the like with a dicarboxylic acid and acrylic acid and 3-40pts.wt. diacrylate of the formula (wherein X is phenylene or cyclohexylene, R is H or CH3 and n is 1-5).

Description

Detailed Description of the Invention <Industrial Application Field> The present invention provides a coating composition for surface curing of synthetic resin molded articles, sheets and films, and a coating composition for curing the surface of synthetic resin molded articles, sheets and films, and a coating composition for improving weather resistance and abrasion resistance by irradiating the composition with ultraviolet rays. , relates to a synthetic resin molded product having a coating formed thereon with excellent hardness, adhesion, and flexibility.

<Prior art> Synthetic resin molded products are used in a wide range of fields because they not only have superior properties such as light weight and toughness compared to glass products, but also have the advantage of being inexpensive and easy to mold. ing. These synthetic resin molded products lack abrasion resistance on the surface, so the surface is easily damaged by contact, impact, scratching, etc. To improve this, cross-linking is applied to the surface of the molded product. Various methods of forming a cured film have been studied in the past. For example, a method has been proposed in which a polymerizable monomer is applied onto the surface of a synthetic resin molded article, and then ultraviolet rays are irradiated to form a crosslinked cured coating on the surface to obtain a coating with excellent wear resistance. (Japanese Patent Publication No. 48-42211, Japanese Patent Publication No. 49-22951, Japanese Patent Publication No. 58-1
(No. 02986, Japanese Unexamined Patent Publication No. 58-104688)
However, although these methods improve the abrasion resistance, which is a drawback of synthetic resin molded products, photodeterioration caused by sunlight, artificial light, etc. remains a practical problem, and there is a strong demand for improvement in weather resistance.

As a method to improve these defects, a coating composition containing various light stabilizers is applied and irradiated with ultraviolet rays to form a cross-linked cured film on the surface to obtain a film with excellent weather resistance. etc. have been proposed. (Unexamined Japanese Patent Publication No. 56-1
41809) Also, as a conventionally known technique, to improve weather resistance, a light stabilizer and an antioxidant are combined, or two types of light stabilizers, such as an ultraviolet absorber and a hindered amine light stabilizer, are combined. (Chemical Industry 5.72 <Problems to be Solved by the Invention>) However, when additives such as light stabilizers and antioxidants are used, Even if a synthetic resin molded product is coated with a coating composition using a coating composition, it does not necessarily provide sufficient weather resistance, and the adhesion to the base material is also insufficient. However, there are disadvantages such as poor flexibility and generation of cracks in heat cycle tests.The latter is a practical method to improve hardness and abrasion resistance while also achieving flexibility and heat cycle resistance. From an important point of view, there was a strong desire to improve weather resistance and adhesion as well as improvements.Also, in terms of the manufacturing process, it is necessary to have excellent curing properties when exposed to ultraviolet rays in the air, and the above-mentioned quality issues It is necessary to satisfy the following problems.The present inventors have arrived at the present invention as a result of intensive studies to improve these points.

In other words, when the coating composition of the present invention is applied to a synthetic resin molded article and irradiated with ultraviolet rays in the air, it has very good curability and exhibits excellent hardness, abrasion resistance, flexibility, and heat cycle test results. It has been found that a film is formed that exhibits well-balanced properties in preventing the formation of cracks, and has excellent weather resistance (no change in wear resistance over time and no crack formation) and adhesion.

Means for Solving Problems> The present invention provides a) polyfunctional monomers 20 to 20 in which a) 8 or more hydroxyl groups in a polyhydric alcohol having 4 or more hydroxyl groups in one molecule are substituted with acryloyloxy groups. 75 parts by weight and b), a polyfunctional polyester acrylate obtained by coesterifying dipentaerythritol, tripentaerythritol, ditrimethylolpropane or ditrimethylolethane with dicarboxylic acid and acrylic acid, pentaerythritol with tricarboxylic acid and acrylic acid. 10 to 60 parts by weight in total of any one or two or more of polyester acrylate obtained by coesterification with C) or polyfunctional urethane acrylate obtained by reaction of a polyisocyanate compound and a hydroxyl group-containing polymerizable acrylic monomer; and C) 0-order general formula (where x represents a phenylene group or cyclohexylene group, R represents a hydrogen atom or a methyl group, n is 1 to 5
is an integer. ) Difunctional acrylates 8 to 4 represented by
0 parts by weight, 0.01 to 5 parts by weight of at least one kind of light stabilizer having a cyclic hindered amine structure, and further 0.01 to 5 parts by weight of at least one kind of antioxidant, per 100 parts by weight of an acrylate mixture consisting of After adding parts by weight of a coating composition and a photosensitizer to the coating composition and applying it to a synthetic resin molded article, sheet, film, etc., it is irradiated with ultraviolet rays to form a surface hardening film. This is a synthetic resin molded product characterized by the following:

Examples of the polyhydric alcohol in a) above include pentaerythritol, diglyserin, ditrimethylolethane, ditrimethylolpropane, dipenta 11J thritol, and tripentaerythritol. Therefore 1
Polyfunctional monomers having eight or more acryloyloxy groups in the molecule include polyacrylates of triacrylates or higher of these polyhydric alcohols. These may be used in combination of one or more types, or may be used as a mixture of two or more types within the composition range.

Specific examples of dicarboxylic acids in b) above include aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, and terephthalic acid; alicyclic dicarboxylic acids such as hexahydrophthalic acid and methylhexahydrophthalic acid; succinic acid; Saturated and unsaturated aliphatic dicarboxylic acids such as malonic acid, adipic acid, sepathic acid, maleic acid and the like may be mentioned. Furthermore, anhydrides of the above dicarboxylic acids can also be used.

Among these dicarboxylic acids, hexahydrophthalic acid,
Tetrahydrophthalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, and cepatic acid can be suitably used.

Examples of tricarboxylic acids include citric acid, tricarballylic acid, 1,8.5-pentanetricarboxylic acid, aconitic acid, trimellitic acid, trimesic acid, and hemimellitic acid. Furthermore, anhydrides of the above tricarboxylic acids can also be used.

Among these tricarboxylic acids, citric acid is preferably used.

Polyester acrylate produced by the coesterification reaction of these dicarboxylic acids and acrylic acids with ditrimethylolethane, ditrimethylolpropane, dipentaerythritol or tripentaerythritol, or polyester produced by the coesterification reaction of tricarboxylic acid, acrylic acid and pentaerythritol. It is possible to impart flexibility to the acrylic material and improve its adhesion to the base material without reducing its properties. Furthermore, it is possible to suppress the generation of cracks in weather resistance tests and increase the crosslinking density, and as a result, the hardness and wear resistance can be improved.

The molar ratio of dicarboxylic acid, acrylic acid, and ditrimethylolethane or ditrimethylolpropane used when synthesizing polyester acrylate is 0.4 to 0.8:1.
1.8-2.0:1 is preferred. In the case of dipentaerythritol, the ratio is preferably 0.4 to 0.8:5.5 to 8:1, and in the case of tripentaerythritol, the ratio is preferably 0.4 to 0.8:5.5 to 8:1.
~0.8m8~4:l is preferred.

The molar ratio of tricarboxylic acid, acrylic acid and pentaerythritol used is 0.1 to 0.5:2 to 4:1, preferably 0.2 to 0.4:2.2 to a, a:i. . The esterification reaction at this time is not particularly limited and can be carried out by a conventional method. One type of these polyester acrylates can be used, or two or more types may be mixed within the composition range. Polyester acrylates derived from alicyclic dicarboxylic acids, such as hexahydrophthalic anhydride, tetrahydrophthalic anhydride, etc., and aliphatic dicarboxylic acids, such as succinic acid, malonic acid, adipic acid, cepatic acid, etc. In comparison, it is particularly preferred because it has excellent crack resistance after a weather resistance test.

Examples of polyisocyanate compounds include tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, or those obtained by hydrogenating aromatic isocyanates among these diisocyanate compounds. Diisocyanate compounds (for example, diisocyanate compounds such as hydrogenated xylylene diisocyanate and hydrogenated diphenylmethane diisocyanate), divalent or octavalent polyisocyanate compounds such as triphenylmethane triisocyanate, dimethylene triphenyl triisocyanate, and diisocyanates. A polyisocyanate compound obtained by multiplying the compound is used.

Hydroxyl group-containing polymerizable acrylic monomers include β-hydroxyethyl acrylate, β-hydroxypropyl acrylate, 1,6-hexanediol diacrylate obtained by partial esterification reaction of polyhydric alcohol and acrylic acid, and glycerin diacrylate. Examples include acrylate, trinotylolpropane diacrylate, ditrimethylolpropane triacrylate, and dipentaerythritol tetraacrylate.

Specific examples of the difunctional acrylate in component C) include ethoxylate, propoxylate, bisphenol A diacrylate, and difunctional acrylates having hydrogenated aromatic rings (for example, hydrogenated ethoxylate or propoxylate). bisphenol A diacrylate).

Among these, ethoxylate bisphenol A diacrylate and ethoxylate hydrogenated bisphenol A diacrylate are preferably used.

The above-mentioned bifunctional acrylate can further improve the adhesion to the substrate, and can also provide a smooth surface and flexibility to the crosslinkable cured coating formed on the synthetic resin molded product. One or more dishes may be used in combination within the composition range.

As a light stabilizer added to the acrylate mixture, 4-
Benzoyloxy-2,2,6,6-titramethylpiperidine, Sepatic acid-bis(2,2,6,6-tetramethyl-4-piperidyl), Sepatic acid-bis(N-methyl-2°2.6 .6-tetramethyl-4-piperidyl)
, and other oligomer type and polymer type light stabilizers having a cyclic hindered amine structure are used.

As antioxidants, 2,6-di-t-butyl-4-methylphenol, tetrakis-[methylene-8-(8',
5'-di-t-butyl-4'-hydroxyphenyl)
[Propionate] Hindered phenol derivatives such as methane, and phosphite derivatives such as trinonylphenyl phosphite and triphenyl phosphite are used.

To explain in detail the composition of the coating composition of the present invention comprising the above-mentioned components a), b), and C), a light stabilizer, and an antioxidant, the content of the polyfunctional monomer of component a) is 20%.
-75 parts by weight, preferably 30-65 parts by weight. If the proportion of the polyfunctional monomer is less than 20 parts by weight, a cured film with sufficient abrasion resistance cannot be obtained, and if it exceeds 75 parts by weight, the abrasion resistance is good, but flexibility and compatibility with the synthetic resin molded product are not obtained. The film will have poor adhesion, and its heat cycle resistance and weather resistance will also deteriorate.

The content of component b), polyester acrylate or polyfunctional urethane acrylate, is 10 to 60 parts by weight, preferably 15 to 50 parts by weight.

If the amount of polyester acrylate or polyfunctional urethane acrylate exceeds 60 parts by weight, the abrasion resistance of the cured film will decrease, and if it is less than 10 parts by weight, the flexibility, adhesion to synthetic resin molded products, and heat resistance of the cured film will decrease. This is not preferable because it reduces cycleability and weather resistance.

The content of difunctional acrylate in component C) is 3 to 40 parts by weight, preferably 5 to 20 parts by weight. If the proportion of this bifunctional acrylate exceeds 40 parts by weight, a cured film with sufficient wear resistance cannot be obtained, and if it is less than 8 parts by weight, flexibility and adhesion to synthetic resin molded products are poor. This is not preferable because it forms a film.

The amount of light stabilizer used is 100% of the acrylate mixture of the present invention.
0.01 to 5 parts by weight, preferably 0.1 to 5 parts by weight
The amount of antioxidant used is 0.01 to 5 parts by weight, preferably 0.05 to 1 part by weight, per 100 parts by weight of the acrylate mixture of the present invention. However, if the amount of the light stabilizer used is too small, the effect of reducing deterioration will be diminished, and if it is too large, whitening or poor adhesion may result, which is not preferable. The same applies to the amount of antioxidant used. Furthermore, one kind or two or more kinds of light stabilizers and antioxidants may be used.

Here, when only a light stabilizer is added, the deterioration reducing effect is weaker than when an antioxidant is used in combination, and although there is a slight improvement in weather resistance, it cannot be said to be sufficient. Furthermore, when only an antioxidant is added, there is no deterioration reducing effect at all compared to when a light stabilizer is added, and no improvement in weather resistance is observed.

In addition, the coating composition of the present invention has a boiling point of 150°C or higher (normal pressure) and a viscosity of 10 centipoise U or lower (25'C).
), one or more mono- and diacrylic esters, one or more ultraviolet absorbers, etc. can be appropriately blended. Such esters are preferred because they provide a smooth surface to the crosslinkable cured coating formed on the synthetic resin molded article, as well as flexibility and adhesion. Specific examples include tetrahydrofurfuryl alcohol, 2-hydroxyethyl acrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, and the like.

Additionally, among these, those with hydroxyl groups, cyclic ether bonds, and ester bonds have excellent polymerizability in air, so
Particularly preferred. However, as for the physical properties of mono- and di-acrylic acid esters, when the boiling point is 150°C or lower (normal pressure), when they are blended into the coating composition of the present invention and applied to the surface of a synthetic resin molded product and cured, they tend to volatize easily. So I don't like it. In addition, the viscosity is 10 centipoise or more (25℃
), the viscosity of the coating composition increases, which is unfavorable for work.

Moreover, ultraviolet absorbers, which are additives other than light stabilizers and antioxidants, are preferable in order to maintain the appearance of the synthetic resin molded product. Specific examples include hydroxybenzoate derivatives such as 2°4-di-t-butylphenyl-8',5'-di-t-butyl-4'-hydroxybenzoate, phenyl f IJ sylate, 4-t-butyl Salicylic acid ester derivatives such as phenyl salicylate, benzophenone derivatives such as 2゜4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, cyanoacrylate derivatives such as ethyl-2-cyano-3゜8-diphenylacrylate, 2- (2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(
Examples include benzotriazole derivatives such as 2'-hydroxy-3'-t-butyl-5'-methylphenyl)-5-chlorobenzotriazole.

Next, the method of using the coating composition of the present invention will be described in detail. The coating composition of the present invention is mixed with a suitable solvent and a photosensitizer, applied to a synthetic resin molded article, and then cured by irradiation with ultraviolet rays. In addition, α rays, β rays, γ rays
It can also be cured by irradiation with active energy rays such as rays and electron beams. As a photosensitizer, benzoin, benzoin ethyl ether, 2-hydroxy-2-methyl-1
-phenylpropan-1-one, 1-hydroxycyclo! Hexyl phenyl ketone, azobisisobutyronitrile, benzoyl peroxide and other commonly known photosensitizers are used. The amount of these photosensitizers used is 1 to 1 per 100 parts by weight of the coating composition of the present invention.
0 parts by weight, preferably 2 to 5 parts by weight. If the amount of photosensitizer used is too large, the cured film may become colored or
If it is too small, curing tends to be insufficient.

Examples of solvents include alcohols such as ethanol, propatool, isopropanol, and butanol; aromatic hydrocarbons such as benzene and toluene; acetate esters such as ethyl acetate and butyl acetate; ketones such as acetone and methyl ethyl ketone; Ethers such as -(2-ethoxyethoxy)ethanol, glycol monomethyl ether, glycol monoethyl ether, and dioxane are used. The amount of solvent used is 100% of the coating composition of the present invention.
It can be used appropriately in the range of 0 to 250 parts by weight.

The synthetic resin molded article whose surface is coated with the coating composition of the present invention may be either a thermoplastic resin molded article or a thermosetting resin molded article, such as polymethyl methacrylate, polycarbonate, polyallyl diglycol carbonate resin, ABS, etc. Molded products of resin, polystyrene, PVC, polyester resin, acetate resin, etc. are used. In particular, in the case of PC (polycarbonate), it can be seen that by using the coating composition of the present invention, the abrasion resistance and adhesion after weathering tests are particularly excellent compared to the conventional technology.

As a coating method, any known method such as brush coating, spray coating, roll coating, or dipping may be used as appropriate. In short,
Any method may be used as long as it provides the desired uniform thickness and smooth surface, and it is preferable to select an appropriate method depending on the shape of the object to be coated. The thickness of the coating is 1 to 80μ, preferably 2.5 to 80μ.
The hardness is in the range of 20μ, and if it is less than 1μ, sufficient hardness cannot be obtained, and if it exceeds 30μ, cracks etc. are likely to occur.

<Effects of the Invention> When using the polyester acrylate synthesized using dipentaerythritol, tripentaerythritol, ditrimethylolpropane or ditrimethylolethane and dicarboxylic acid of the present invention (Examples 1 to 4), pentaerythritol and tricarboxylic acid were used. When polyester acrylates synthesized using acids (e.g. citric acid) are used (Example 5.6) or polyfunctional urethane acrylates (Example 8.9) and other polyhydric alcohols or other Comparing cases where polyester acrylate made of carboxylic acid is used (Comparative Examples 11 to 13), the abrasion resistance of the initial physical properties and the abrasion resistance after 1000 hours of weather resistance test are both A, while the latter is A. are B and D.

Also, the light stabilizer or antioxidant was removed from the composition of the present invention (Example 1) and the composition of the present invention. Furthermore, when comparing the composition of the present invention (Example 1) and the composition of the present invention in which ethoxylate bisphenol A diacrylate of component C) was removed (Comparative Example 1), the adhesion after 500 hours of weather resistance test was found. is 0/100 to 100/100.

From these facts, the composition using the polyester acrylate of the present invention has particularly excellent hardness at the initial stage and after the weather resistance test, and is also excellent in adhesion, flexibility, and heat cycle resistance test.

<Examples> The present invention will be specifically explained below using examples, but the present invention is not limited to these examples.

Production Example a of Coating Composition Components Polyfunctional Monomer Synthesis Example I Synthesis of Dipentaerythritol-rhexaacrylate Dipentaerythritol 127f, Acrylic acid 259y, mixed solvent (benzene: cyclohexane = 2:
1) 127y1 sulfuric acid 6.85f1 copper sulfate 0.51f, hydroquinone monomethyl ether o, o a y were charged.

The reaction was carried out under reflux while stirring and blowing air, and the distilled organic solvent/water azeotrope mixture was separated from water after cooling, and the organic solvent was returned to the reaction system for reaction, and 52 CC of water was distilled out. . Then, the reaction solution was cooled and a mixed solvent (benzene:
Add cyclohexane = 2:1) 254y, concentration 10%
After neutralizing with an aqueous solution of caustic soda, the oil layer was separated into 1
Washed with 0% saline.

After drying the oil over anhydrous magnesium sulfate, the oil was dried with a mixed solvent (benzene: cyclohexane = 2
:1) was removed to obtain dipentahexaacrylate 271y as a residue. The viscosity of this product is 9410 cps/2
The 5°C1 ster value was 552 (theoretical value 582.5).

Synthesis Example 2 Synthesis of ditrimethylolpropane tetraacrylate Dipentaeryth')h-ru 127f in Synthesis Example 1 was replaced with ditrimethylolpropane 125y, and acrylic acid 2
The reaction was carried out in the same manner as in Synthesis Example 1 except that 59y was replaced with 173y to obtain ditrimethylolpropane tetraacrylate 223y as a residue.

The viscosity of this product was 568 Cps/25°c1 and the ester value was 470 (theoretical value 482).

b Polyester acrylate synthesis example 1 Dipentaerythritol 127yco (5 mol),
Adipic acid 88y (0.26 mol), acrylic acid 187y
y (2.6 mol), benzene 127f, sulfuric acid 6.8f,
Copper sulfate 0.5j, hydroquinone monomethyl ether o
, I prepared oay.

The reaction was carried out under reflux with stirring and air blowing, and the benzene and water azeotrope mixture distilled out was separated from the water after cooling, and the benzene was returned to the reaction system for reaction, and 52 cc of water was distilled out. Then, the reaction solution was cooled, a mixed solvent of benzene:cyclohexane (5:1) was added, and after neutralization with a 10% aqueous solution of caustic soda, the mixture was separated and the oil layer was washed with a 10% brine. After drying the oil over anhydrous magnesium sulfate, the benzene-cyclohexane mixed solvent was removed under reduced pressure at 50 to 60°C to obtain pale yellow polyester acrylate 3091 as a residue. The viscosity of this product is 80 at 50°C.
20 cps, and the ester value was 519.

Synthesis Example 2 Pentaerythritol 186y (1 mol), citric acid 70fC0.88 mol), acrylic acid 216f (3 mol), toluene 500g, and sulfuric acid were placed in 11 glass reactors equipped with a stirrer, thermometer, and water separator. e, 8y, copper sulfate o, 5
y1 0.111 of hydroquinone monomethyl ether was charged.

The reaction was carried out under reflux while stirring and blowing air, and the distilled toluene/water azeotrope was separated from water after cooling, and the toluene was returned to the reaction system for reaction, and 72 cc of water was distilled out. After cooling the reaction solution, the ester layer was separated and dissolved in chloroform. After neutralizing it with a 10% aqueous solution of caustic soda, the oil layer was separated and washed with a 10% saline solution. After drying the oil with anhydrous magnesium sulfate,
The chloroform solvent was removed under reduced pressure at ~60°C to obtain pale yellow polyester acrylate 325y as a residue.

The viscosity of this product was 5867 cps at 50°C, and the ester value was 796.

Synthesis Examples 3 to 18 Polyhydric alcohol, carboxylic acid and acrylic acid were used. The results are shown in Table-1.

C polyfunctional urethane acrylate synthesis example 19 Trimethylolpropane diacrylate 2429 was placed in 11 glass reactors equipped with a stirrer, a thermometer, and a dropping funnel.
．． 0.251 of hydroquinone monomethyl ether was added, and 85 f of 2.4-) lylene diisocyanate was added dropwise over 1 hour while the temperature was maintained at 60°C. Stir for 1 hour at the same temperature, dibutyltin diacetate 0.051
was added, and the reaction was continued for another 2 hours to complete the reaction, to obtain 325 polyfunctional urethane acrylates. The isocyanate content of this was 0.08%.

Synthesis Examples 20 to 83 Polyfunctional urethane acrylates were synthesized by carrying out the reaction in the same manner as in Synthesis Example 17, except that the types and amounts of the hydroxyl group-containing polymerizable monomer and polyisocyanate were changed. The results are shown in Table-2.

Synthesis Example 1 for Comparative Example (Synthesis 1 of Comparative Polyester Acrylate) Pentaerythritol 136f (1 mol) and hexahydrophthalic anhydride 72f (0,5 mol, IL'), acrylic acid 216F (8 mol), toluene 500, sulfuric acid 6.89. Copper sulfate o, 4y1 hydroquinone monomethyl ether 0.119 was charged.

The reaction was carried out under reflux while stirring and blowing air, and the distilled toluene/water azeotrope was separated from water after cooling, and the toluene was returned to the reaction system for reaction, and 53 cc of water was distilled out. Cool the reaction solution and add toluene solvent to a concentration of 10.
After neutralizing with aqueous sodium hydroxide solution, the oil layer was separated into 10%
% saline solution. After drying the oil over anhydrous magnesium sulfate, the toluene solvent was removed under reduced pressure at 50 to 60°C to obtain a pale yellow polyester acrylate 398y as a residue.

The viscosity of this product was 4803 cps at 50°C, and the ester value was 482.

Comparative Example Synthesis Example 2 In a 21 glass flask equipped with a stirrer, a thermometer, and a water separator, 120.2 F (1 mol) of trimethylolethane was added.
Succinic acid 65.0f (0.55 mol), acrylic acid 15
8.6y (2.20 mol), toluene 1000 f%C
uC/, 8 f, p-torxence #phonic acid 18.
I prepared 5F.

The reaction was carried out under reflux with stirring and air blowing, and the distilled toluene/water azeotrope was separated from water after cooling, and the toluene was returned to the reaction system for reaction, and 52 cc of water was distilled out. After cooling the reaction solution, the oil layer was separated, and the oil layer was washed twice with a 0.5% sulfuric acid aqueous solution and then three times with pure water. After washing, the oil was dried over anhydrous magnesium sulfate, and toluene was removed under reduced pressure at 50 to 60°C to obtain a pale yellow polyester acrylate as a residue. The viscosity of this compound was 8300 cps at 20''C.

Comparative Synthesis Examples 3 to 6 Polyester acrylates were synthesized by performing an esterification reaction in the same manner as in Comparative Synthesis Example 1, except that the amounts of polyhydric alcohol, carboxylic acid, and acrylic acid were changed. The results are shown in Table-8.

Examples (1 to 9) and Comparative Examples (1 to 13) The coating method for synthetic resin plates, the test method, and the characteristics of the cured film are shown below.

As shown in Table 3, a solvent and a photosensitizer were added to the coating composition of the present invention, and a transparent polycarbonate resin plate (manufactured by Takiron Co., Ltd.) with a thickness of 20 mm was immersed in the coating composition to form a film for 20 minutes. After leaving the resin plate in the air, a metal halide lamp (UEO15 manufactured by I-Graphics) was used.
1-802C, M015-L31) and was irradiated with ultraviolet rays at 120 W for 5 to 10 seconds from a distance of 100 silk.

The abrasion resistance, hardness, appearance, and adhesion of the polycarbonate resin plate on which the thus obtained cured film was formed are shown in Table 3 and Tables 4 and 5.

The composition and evaluation method in the table are explained below.

Note-1) Polyalkoxylate bisphenol A diacrylate ethoxylate bisphenol A diacrylate 2) Solvent isopropanol: toluene = 50:508) Photosensitizer 1-hydroxycyclohexylphenyl ketone 4) Abrasion resistance: $0000 Scratch test with steel A: No scratches even when rubbed hard B: Slight scratches when rubbed hard C: Slight scratches when rubbed lightly D: Significant scratches even when rubbed lightly 5) Hardness: JIS Pencil hardness according to K5651-1966 6) Adhesion: Cross-cut cellophane tape peeling test
....Draw 11 film cutting lines vertically and horizontally that reach the base material on the film at In intervals to make 100 pieces of 1 piece and 2 pieces, stick cellophane tape on it and peel it off rapidly.

After repeating this cellophane tape operation three times at the same location, the number of tapes that did not peel off is shown in Table 7) Il [Fr Note:
Naun Seri lacquer promotion unwipe discipline shibori straight support, six middle Atlas nibukon (
(Newly manufactured by Toyo Seiki) was used. The conditions were repeated exposure to ultraviolet light at 60°C for 4 hours, followed by 4 hours of wet exposure at 40°C. After 500 hours under these cycle conditions, 100
Appearance after 0 hours, steel wool test, and adhesion were examined.

8) Heat cycle test 2 The molded product with a hardened film formed on its surface is immersed in warm water at 65°C for 1 hour, then immediately immersed in ice water for 10 minutes, and then dried at 80″C for 1 hour, which is repeated 5 times. .

After the heat cycle test, the appearance, abrasion resistance, and adhesion are tested.

9) Light stabilizer: sebacic acid-bis(2,2,6,6-tetramethyl-4-piperidyl) 10) Light stabilizer: sebacic acid-bis(N-methyl-2,
2,6,6-tetramethyl-4-piperidyl) 11) Light stabilizer; 4-benzoyloxy-2,2,6°6-titramethylpiperidine 12) Light stabilizer: 4-octanoyl-2,2,6 ,6-
Titramethylpiperidine 1B) Antioxidant: Tetrakis-[methylene-3=(8
',5'-di-t-butyl-4'-hydroxyphenyl)propionate] 14) Antioxidant: n-octadecyl-8-(1').

5/-di-t-butyl-4'-hydroxyphenyl)propionate 15) Antioxidant nitrinonylphenyl phosphite 16) Antioxidant nitriphenyl phosphite 17)
UV absorber 2-hydroxy-4-methoxybenzophenone 18) UV absorber 2-(2'-hydroxy-5'-methylphenyl)benzotriazole 19) UV absorber 2.4-di-t-butylphenyl-3' , 5'-G t
-Butyl-4'-hydroxybenzoate 20) Ultraviolet absorber ethyl-2-cyano-3,3-diphenylacrylate

Claims (1)

[Scope of Claims] 1. a) 20 to 75 parts by weight of a polyfunctional monomer in which a polyhydric alcohol having 4 or more hydroxyl groups in one molecule is substituted with 3 or more acryloyloxy groups, and b) , polyfunctional polyester acrylate obtained by coesterifying dipentaerythritol, tripentaerythritol, ditrimethylolpropane or ditrimethylolethane with dicarboxylic acid and acrylic acid, and polyfunctional polyester acrylate obtained by coesterifying pentaerythritol with tricarboxylic acid and acrylic acid. c), a total of 10 to 60 parts by weight of one or more of the polyester acrylate obtained by the reaction of a polyisocyanate compound and a hydroxyl group-containing polymerizable acrylic monomer, and c), the following general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, X represents a phenylene group or cyclohexylene group, R represents a hydrogen atom or a methyl group.
is an integer. ) Bifunctional acrylates 3 to 4 represented by
0.01 to 5 parts by weight of at least one kind of light stabilizer having a cyclic hindered amine structure, and further 0.01 to 5 parts by weight of at least one kind of antioxidant per 100 parts by weight of the acrylate mixture consisting of 0 parts by weight. A coating composition comprising the addition of 50%. 2. The coating composition according to claim 1, wherein the polyhydric alcohol is dipentaerythritol, tripentaerythritol, ditrimethylolpropane or ditrimethylolethane. 3. Coating composition according to claim 1, wherein the tricarboxylic acid is citric acid. 4. Mono- and diacrylic acid esters having a boiling point of 150° C. or higher (normal pressure) and a viscosity of 10 centipoise or lower (25° C.). The coating composition 5 according to claim 1 containing one or more types of ultraviolet absorbers, the coating composition 6 according to claim 1 containing one or more types of ultraviolet absorbers, a), one molecule 20 to 75 parts by weight of a polyfunctional monomer in which a polyhydric alcohol having 4 or more hydroxyl groups is substituted with 3 or more acryloyloxy groups; and b) dipentaerythritol, tripentaerythritol, ditrimethylolpropane. Or polyfunctional polyester acrylate obtained by coesterifying ditrimethylolethane with dicarboxylic acid and acrylic acid, polyester acrylate obtained by coesterifying pentaerythritol with tricarboxylic acid and acrylic acid, or polymerization with a polyisocyanate compound containing a hydroxyl group. 10 to 60 parts by weight of any one or two or more polyfunctional urethane acrylates obtained by reaction with a polyfunctional urethane acrylate monomer, and c) the following general formula ▲ Numerical formula, chemical formula, table, etc. ▼ (in the formula , X represents a phenylene group or a cyclohexylene group, R represents a hydrogen atom or a methyl group, n is 1 to 5
is an integer. ) Bifunctional acrylates 3 to 4 represented by
0.01 to 5 parts by weight of at least one kind of light stabilizer having a cyclic hindered amine structure, and further 0.01 to 5 parts by weight of at least one kind of antioxidant per 100 parts by weight of the acrylate mixture consisting of 0 parts by weight. A photosensitizer is added to a coating composition, which is applied to a synthetic resin molded article, sheet or film, and then irradiated with ultraviolet rays to form a surface-cured coating. Synthetic resin molded product. 7. The synthetic resin molded article according to claim 4, wherein the polyhydric alcohol is dipentaerythritol, tripentaerythritol, ditrimethylolpropane or ditrimethylolethane. 8. The synthetic resin molded article according to claim 4, wherein the tricarboxylic acid is citric acid. 9. The synthetic resin molded article according to claim 6, which contains one or more mono- and diacrylic acid esters having a boiling point of 150° C. or higher (normal pressure) and a viscosity of 10 centipoise or lower (25° C.). 10. Synthetic resin molded product according to claim 6 containing one or more types of ultraviolet absorbers