JPS6129386B2 - - Google Patents

Description

[Detailed description of the invention]

This invention relates to (a) urethanized epoxy acrylate (or methacrylate) obtained by adding acrylic acid (or methacrylic acid) to the epoxy group of urethanized epoxy resin, (b) ketone obtained by condensing a ketone compound and an aldehyde. resin, and (c)
Contains a polymerizable crosslinking agent or polymerizable oligomer having two or more ethylenically unsaturated groups derived from acrylic acid (or methacrylic acid) as an essential component, and the ratio of the essential component is (a) 2 to 55%. ,(b)5～
40%, and (c) for coating compositions curable by electromagnetic waves or particle beams in the range of 5 to 93%, paper;
The purpose of the present invention is to provide a coating composition that has excellent adhesion to various substrate surfaces such as wood, plywood, plastics, glass, and metal. First, the essential components (a) to (c) of the curable coating composition of the present invention will be described. (a) Urethane epoxy acrylate (or methacrylate) is made by reacting acrylic acid (or methacrylic acid) with a urethane epoxy resin that has an epoxy group and a urethane bond, and adding acrylic acid (or methacrylic acid) to the epoxy group. If it is a compound and the model (scheme) is shown: In the above formula, 〓〓〓 indicates the residue of the polymer,
R represents hydrogen or a methyl group. The urethanized epoxy resin used as a starting material is a polyadduct obtained by reacting an epoxy resin with a hydroxyl group with an isocyanate compound to form a urethane bond between the hydroxyl group and the isocyanate group, and retains the reactive epoxy group. It is a resin. This type of urethanized epoxy resin is used as a flexible epoxy resin in the art as a room-temperature or thermosetting resin by mixing it with an epoxy curing agent, and many varieties are available as commercial products. In the reaction between the urethanized epoxy resin and acrylic acid (or methacrylic acid), it is preferable to use an equivalent amount of unsaturated acid with respect to the epoxy group content of the resin. In this addition reaction, catalysts include tertiary amines such as triethylamine, tri-n-butylamine, dimethylbenzylamine, and triethanolamine, ammonium salts such as triethylbenzylammonium chloride and methyltrinitylammonium iodide, and bases such as quinoline and isoquinoline. It is advantageous to add a heterocyclic compound, a metal soap such as tin octylate, and a strong organic acid such as p-toluenesulfonic acid. Furthermore, a non-functional organic solvent may be used as a reaction diluent, but it is preferable to use (iii) a low viscosity compound having an ethylenic functional group as the diluent, which is one of the essential compositions of this invention. is reasonable. Examples of unsaturated acid addition reactions to urethanized epoxy resins include: Reference example 1 Urethane epoxy resin (Asahi Denka EPU-10) 68 parts by weight Acrylic acid 14.4 parts by weight Triethylbenzylammonium chloride
0.5 parts by weight Trimethylolpropane triacrylate (functional diluent) 55 parts by weight Hydroquinone monomethyl ether (thermal polymerization inhibitor) 0.14 parts by weight The above mixture was heated to 100°C while blowing dry air.
A trimethylolpropane triacrylate solution of urethanized epoxy acrylate was produced. Reference example 2 Urethane epoxy resin (EPU-6)
94 parts by weight Acrylic acid 28.8 parts by weight Trimethylolpropane triacrylate
61.4 parts by weight Tin octylate (tin content 28%) 1.2 parts by weight Benzyldimethylamine 0.5 parts by weight Hydroquinone monomethyl ether 0.2 parts by weight The above mixture was heated to 100°C while blowing dry air.
A trimethylolpropane triacrylate solution of urethanized epoxy acrylate was produced. (b) Ketone resin is a resin obtained by condensing ketones with a relatively simple structure such as acetone, methyl ethyl ketone, cyclohexane, and acetophenone with a lower aliphatic aldehyde such as formaldehyde, and is commercially available in various properties. It is available as . This ketone resin is used as an additive component in lacquers, vinyl paints, printing inks, etc. for the purpose of improving weather resistance, adhesion, etc. Ketone resin is produced by adding an excess amount of aldehyde to ketone in the presence of an alkali catalyst, and when heated, dehydration condensation easily occurs through the step of forming a methylol derivative to give a resin. Depending on the type of ketone, a resin with a complex structure can be produced, but taking the case of cyclohexanone and formaldehyde, which are estimated to have a relatively simple structure, as an example: The above formula

[Formula] represents cyclohexanone. (c) Compounds having two or more ethylenically unsaturated groups are classified into two types: (i) polymerizable crosslinking agents and (ii) polymerizable oligomers, and either one of these or a mixture of both can be used. It is added as an essential component to the curable coating composition. (i) Polymerizable crosslinking agent Examples of polymerizable crosslinking agents include acrylate (or methacrylate), which is obtained by esterifying a compound with about 2 to 6 hydroxyl groups with acrylic acid (or methacrylic acid) and introducing an unsaturated group. It will be done. Specific examples include ethylene glycol diacrylate, diethylene glycol diacrylate, 1,4-butanediol diacrylate, bentaerythritol tetraacrylate, dipentaerythritol polyacrylate (with 6 or less acrylate groups), polyethylene glycol diacrylate , 2,2'-bis(4-acryloxydiethoxyphenyl)propane, and methacrylate isoforms corresponding to each of the above compounds. (ii) Polymerizable oligomers Polymerizable oligomers include (a) polyester acrylate (or polyester methacrylate) which is liquid at room temperature and is obtained by reacting a low molecular weight polyester having free carboxyl groups with hydroxyalkyl acrylate (or hydroxyalkyl methacrylate); Alternatively, polyester acrylate (or polyester methacrylate) obtained by reacting a low molecular weight polyester with free hydroxyl groups with acrylic acid (or methacrylic acid) can be used. Furthermore, (b) epoxy acrylate (or epoxy methacrylate) obtained by polyadding acrylic acid (or methacrylic acid) to an unmodified epoxy resin, or (c) hydroxyalkyl acrylate (or hydroxyalkyl methacrylate) to a prepolymer having an isocyanate group. Each of the urethane acrylates (or urethane methacrylates) obtained by reacting them has suitability as a polymerizable oligomer. If the above schemes (i) to (iii) are shown: In the above scheme, A represents an alkylene group, R represents a hydrogen atom or a methyl group, and the symbol 〓
represent (i) a polyester residue, (ii) an unmodified epoxy resin residue, and (iii) a urethane resin residue, respectively. Specifically, the raw materials for the polymerizable oligomer are as follows: Low molecular weight polyester (polyester prepolymer) is an aliphatic unsaturated dibasic acid such as maleic anhydride, fumaric acid, itaconic acid, phthalic anhydride, isophthalic acid, etc. Acid components such as aromatic dibasic acids or their anhydrides, aliphatic saturated dibasic acids or their anhydrides such as succinic anhydride, adipic acid, glutaric acid, endo-methylenetetrahydrophthalic anhydride, and ethylene glycol. , diethylene glycol, propylene glycol, hydrogenated bisphenol A, neopentyl glycol, or alcohol components such as diols and polyols such as glycerin without a catalyst or in the presence of a strong acid catalyst,
It is a prepolymer that usually has about 300 to 3000 free carboxyl groups or free hydroxyl groups, which are obtained by dehydration condensation with an excess of either the acid component or the alcohol component. When reacted with a polyester prepolymer having free carboxyl groups, hydroxyalkyl acrylates (or hydroxyalkyl methacrylates), such as 2-hydroxyethyl acrylate (or 2-hydroxyethyl methacrylate), 2-hydroxypropyl acrylate (or 2-hydroxypropyl methacrylate). Furthermore, polyester prepolymers having free hydroxyl groups can be reacted with, for example, acrylic acid (or methacrylic acid) to obtain polyester acrylates (or methacrylates), respectively. Next, unmodified epoxy resin means an epoxy resin that is not subjected to urethane modification or other treatment,
Bisphenol A [2,2-bis(4-hydroxyphenyl)propane], bisphenol B
[2,2-bis(p-hydroxyphenyl)butane], halogenated bisphenol A [e.g. 2,
2-bis(3,5-dichloro-4-hydroxyphenyl)propane], 2,2-(2,4-dihydroxyphenyl-4-hydroxyphenyl)propane, 4,4'-dihydroxydiphenylsulfone, Alternatively, it is a resin having a terminal epoxy group produced by reacting epichlorohydrin or β-methylepichlorohydrin with a phenolic compound such as resorcinol, saligenin, phloroglucinol, hydroxybenzoic acid, or novolak resin or cresol resin. Prepolymers having isocyanate groups include phenylene diisocyanate, tolylene diisocyanate, hexamethylene diisocyanate, hydrogenated tolylene diisocyanate, diphenylmethane diisocyanate, etc., and ethylene glycol, diethylene glycol, and triethylene glycol. Alternatively, it is a polymer that is liquid at room temperature and is obtained by synthesizing glycerin or the like with a reaction composition lacking in hydroxyl groups so that the product retains unreacted isocyanate. Known methods can be used to produce the raw materials for the polymerizable oligomers described above, and the method of introducing ethylenically unsaturated groups into the raw material prepolymers is also well known in the technical field. Reference example 3 (i) Polyester acrylate) Isophthalic acid 83 parts by weight Diethylene glycol 106 parts by weight Adipic acid 146 parts by weight p-Toluenesulfonic acid (catalyst) 2.5 parts by weight Reaction of the above at 120°C When the acid value reached 150, 116 parts by weight of 2-hydroxyethyl acrylate and 0.45 parts by weight of hydroquinone monomethyl ether (thermal polymerization inhibitor) were added and reacted while blowing air to synthesize polyester acrylate. Reference example 4 ((ii) Epoxy acrylate) Epoxy resin (Ciel Chemical Epicote 828)
94.5 parts by weight Acrylic acid 36 parts by weight N,N-dimethylaniline (catalyst) 1.3 parts by weight Air was blown into the above mixture at 100° C. to cause a reaction to obtain epoxy acrylate. Reference example 5 ((iii) urethane acrylate) Tolylene diisocyanate (2.4-substituted product/2.6-disubstituted product = 80/20)
174 parts by weight Triethylene glycol 75 parts by weight 1.6-hexanediol diacrylate (polymerizable crosslinking agent is added as a reaction diluent)
200 parts by weight Hydroquinone monomethyl ether 0.57 parts by weight The above mixture was reacted at 60°C for 4 hours while blowing air to create a prepolymer with isocyanate groups at both ends of the resulting polymer, and 116 parts by weight of 2-hydroxyethyl acrylate was added. ,
The reaction was carried out at 60°C for 6 hours to obtain urethane acrylate. It should be noted that the compounds and manufacturing methods cited in the explanations of and are described for the purpose of illustration, and are not intended to limit the content of the present invention. The above-mentioned (a), (b) and (c) are essential components of the curable coating composition, (a) 2 to 55%, (b) 5 to 40% and
(c) may be contained in the range of 5 to 93%, but for normal use (a) 5 to 40%, (b) 15 to 30% and (c) 30 to 80%.
% ranges are very advantageously used. As described later in the examples, (a), (b) and
Even if any one of the components (c) is missing, the adhesion and other properties of the curable coating composition will suffer, and compositions containing (a), (b) and (c) will have problems. Even though
It has been found that the performance of the cured film is poor when it is outside the range limited above. Next, when preparing the curable coating composition, if a lower viscosity is required, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-ethylhexyl acrylate, benzyl acrylate, tetrahydrofurfuryl acrylate (or 2-hydroxypropyl acrylate, Ethyl methacrylate, 2-hydroxypropyl methacrylate,
2-ethylhexyl methacrylate, benzyl methacrylate, tetrahydrofurfuryl methacrylate), styrene, p-acetylstyrene, N
- 1 ethylenically unsaturated bond such as vinylpyrrolidone
Individual monofunctional monomers can be incorporated. Furthermore, in order to suppress dark reactions during storage of the curable coating composition and improve storage stability, hydroquinone, hydroquinone monomethyl ether, 2,6-
It is desirable to add a thermal polymerization inhibitor such as di-tert-butyl-p-cresol in an amount of about 10 to 1000 ppm. Depending on the application, a thixotropic agent such as fine powder-free silica, a fluorine-containing surfactant such as potassium verfluorocaprate may be added as a leveling agent, or hexabromobenzene, chlorinated polyethylene, etc. may be added to the curable coating composition. It is also possible to make the cured film flame retardant by adding halogenated hydrocarbons, phosphate esters such as tris(monochloropropyl) phosphate and tricresyl phosphate, antimony compounds such as antimony trioxide, and other flame retardants. be. A colored cured film can be created by adding a coloring agent to the curable coating composition. Some examples of dyes and pigments used as colorants for this purpose are CI Pigment Yellow 7, CI Pigment Red 53, CI Pigment Red 57, CI
Pigment Blue 15, Carbon Black, Titanium White, etc. For the purpose of curing the coating composition by irradiating it with ultraviolet/near ultraviolet electromagnetic waves, it is usually desirable to add a photosensitizer. Photosensitizers include benzophenone, Mitsuhler's ketone, acenaphthoquinone,
Known compounds such as 2-methylanthraquinone, phenanthrenequinone, benzoin methyl ether, benzoin isopropyl ether, 5-nitroacenaphthene, and azobisisobutyronitrile can be used. The curable coating composition comprising the above-described essential ingredients and various additives is applied to the substrate surface under yellow safety lights by coating methods well known in the art. Specific examples of substrates include natural wood, particle board, hardboard, printed board,
Alternatively, there are printed materials on iron plates, tin plates, paper, plastics, or metals, organic and inorganic woven fabrics, non-woven fabrics, laminates in the electronics industry, and flexible substrates. The cured film on these substrates is
It is provided for purposes such as surface decoration, surface protection, gloss imparting, resin impregnation, resist film, and marking ink. When the coating composition or impregnating liquid, which is liquid at room temperature and applied to or impregnated onto a substrate, is irradiated with electromagnetic waves or particle beams, it hardens on the substrate. Alternatively, an electron beam generated from a high-pressure cathode gun is practically advantageous. 240 ~ as a light source for ultraviolet/near ultraviolet curing
Chemical lamps with high luminous efficiency in the 480 nm wavelength range, high-pressure mercury lamps, metal halide lamps, xenon lamps, etc. are used. For the electron beam irradiation, a commercially available electron beam coating curing device equipped with an electron beam generator for curing the coating film is used. This invention will be described in detail with reference to Examples below. Example 1 Urethane epoxy acrylate solution of Reference Example 1 60 parts by weight Hiraku 111 (ketone resin manufactured by Hitachi Chemical)
20 parts by weight, 10 parts by weight of trimethylolpropane acrylate, 10 parts by weight of 2-hydroxypropyl acrylate, and 2 parts by weight of benzoin ethyl ether were uniformly mixed to obtain a 30 poise (25°C) resin composition. The above composition and the compositions of Comparative Examples 1 and 2 below were each irradiated with light and cured, and the test results shown in Table 1 were obtained for the cured films. Comparative Example 1 A composition obtained by removing only the urethanized epoxy acrylate from the composition of Example 1. Ketone resin (Hiraku 111) 20 parts by weight Trimethylolpropane triacrylate
34 parts by weight 2-hydroxypropyl acrylate 10 parts by weight Benzoin ethyl ether 2 parts by weight Comparative Example 2 A composition obtained by removing only the ketone resin from the composition of Example 1. Urethane epoxy acrylate solution of reference row 1 60 parts by weight Trimethylolpropane triacrylate
10 parts by weight 2-hydroxypropyl acrylate 10 parts by weight Benzoin ethyl ether 2 parts by weight Iwasaki Electric's high-pressure mercury lamp was used for light irradiation for curing.
Using HO-2L21 (80 W/cm), the coated film was passed through a substrate on a steel wire mesh belt kept at a distance of 14 cm, and cured. For the adhesion test in the table, a film with a thickness of 30 to 40 μm was applied onto the substrate, photocured, and 100 1 mm squares (10×
10), attached cellophane tape to the cured film, and immediately peeled it off to display the number of squares remaining. In the following examples, photocuring and adhesion tests were conducted using the same method.

[Table] Example 2 Urethane epoxy acrylate solution of Reference Example 2 45 parts by weight Ketone resin (Hiraku 111) 30 parts by weight Trimethylolpropane triacrylate
15 parts by weight, 10 parts by weight of tetrahydrofurfuryl acrylate, 0.5 parts by weight of benzoin ethyl ether, and 1.7 parts by weight of benzyl were mixed to obtain a resin composition of 35 poise (25° C.). Comparative Example 3 A composition in which only the urethanized epoxy acrylate of Example 2 was removed. Ketone resin 30 parts by weight Trimethylolpropane triacrylate
30 parts by weight Tetrahydrofurfuryl acrylate 10 parts by weight Benzoin ethyl ether 0.5 parts by weight Benzyl 1.7 parts by weight Comparative Example 4 Composition of Example 2 except for the ketone resin. Urethane epoxy acrylate solution of Reference Example 2 45 parts by weight Trimethylolpropane triacrylate
15 parts by weight Tetrahydrofurfuryl acrylate 10 parts by weight Benzoin ethyl ether 0.5 parts by weight Benzyl 1.7 parts by weight The compositions of Example 2, Comparative Example 3, and Comparative Example 4 were applied to a copper plate, a glass plate, and an aluminum plate, respectively.
It was cured by light irradiation, and the test results shown in Table 2 were obtained for the cured film.

[Table] Example 3 Urethane epoxy acrylate solution of Reference Example 2 30 parts by weight Ketone resin (Hiraku 110) 25 parts by weight Epoxy acrylate of Reference Example 4 20 parts by weight Diethylene glycol diacrylate 25 parts by weight Benzophenone: Michler's ketone = 8: 1
2.5 parts by weight were mixed to obtain a resin composition of 35 poise (25°C). Comparative Example 5 A composition in which only the urethanized epoxy acrylate of Example 3 was removed. Ketone resin (Hiraku 110) 25 parts by weight Epoxy acrylate of Reference Example 4 20 parts by weight Trimethylolpropane triacrylate
10 parts by weight Diethylene glycol diacrylate 25 parts by weight Benzophenone: Michler's ketone = 8:1
2.5 parts by weight Comparative Example 6 A composition in which only the ketone resin of Example 3 was removed. Urethane epoxy acrylate solution of Reference Example 2 30 parts by weight Epoxy acrylate of Reference Example 4 20 parts by weight Diethylene glycol diacrylate 25 parts by weight Benzophenone: Michler's ketone = 8:1
2.5 parts by weight Example 3, Comparative Example 5, and Comparative Example 6 were applied to a stainless steel plate, a copper plate, and a glass plate, and photocured to obtain the test results shown in Table 3 for the cured films.

[Table] Next, a wiring pattern with a minimum line width of 250 μm was screen printed on a glass fiber reinforced epoxy copper laminate (manufactured by Sumitomo Electric Industries, Ltd.) using the composition of Example 3, and the plating resistance was examined. That is, the composition pattern on the screen-printed copper laminate was photocured, and the liquid temperature was 55°C.
Copper pyrophosphate plating was performed at a pH of 8.7 and a cathode current density of 4 A/dm ² , and the changes in the cured film after plating and changes in the pattern due to penetration of the plating solution were inspected, but no abnormalities were observed and the plating resistance was sufficient. I found out that there is a sex. In addition, the composition of Example 3 was applied to a copper foil-polyimide resin laminate flexible board (1 oz.
It was coated on a 35μ thick polyimide manufactured by DuPont (USA) and laminated with an adhesive layer of approximately 30μ (a product made by Rexham, USA), photocured, and immersed in a solder bath kept at 260℃ for 1 minute, but no abnormality was observed in the cured film. It had sufficient heat resistance. At the same time, the cured film on the copper foil-polyimide resin laminate flexible substrate was immersed in trichlene for 1 hour, and no abnormalities such as swelling or peeling were observed, and it had sufficient solvent resistance. Example 4 33 parts by weight of the urethanized epoxy acrylate solution of Reference Example 1, 27 parts by weight of the ketone resin (Hiraku 111), 22 parts by weight of the polyester acrylate of Reference Example 3, and 18 parts by weight of 2-hydroxypropyl acrylate were thoroughly mixed to give a solution of 67 poise (25 ℃) was obtained. When the above composition was applied to a thickness of 100 μm on a hardboard and irradiated with an electron beam at an accelerating voltage of 400 KV and a current density of 20 mA, the coating film was cured with a radiation absorption amount of 1.5 Mrad.

Claims (1)

[Claims] 1. (a) urethanized epoxy acrylate (or methacrylate) obtained by adding acrylic acid (or methacrylic acid) to the epoxy group of a urethanized epoxy resin, (b) a ketone compound and an aldehyde. Electromagnetic waves or particles containing as essential components a ketone resin obtained by condensation and (c) a polymerizable crosslinking agent or polymerizable oligomer having two or more ethylenically unsaturated groups derived from acrylic acid (or methacrylic acid) A coating composition that is curable by radiation. 2 (a) Acrylic acid (or methacrylic acid) is added to a urethanized epoxy resin obtained by reacting a urethane prepolymer containing unreacted isocyanate groups with an epoxy compound having hydroxyl groups. 2. The curable coating composition according to claim 1, which is a resin to which is added the following: 3 (b) Claim 1, wherein the ketone resin is a dehydration condensate of any one of dialkyl ketones, cycloalkylene ketones, alkylaryl ketones, or diaryl ketones and lower alkyl aldehydes such as formaldehyde and acetaldehyde. Curable coating composition as described in Section 1. 4 (c) A polymerizable crosslinking agent having two or more ethylenically unsaturated groups esterifies a compound having two to six hydroxyl groups with acrylic acid (or methacrylic acid), The curable coating composition according to claim 1, which is a compound having an unsaturated group derived from acrylic acid (or methacrylic acid). 5 (c) Polyester acrylate (or polyester methacrylate) obtained by reacting a polymerizable oligomer having two or more ethylenically unsaturated groups with a polyester prepolymer having free carboxyl groups and hydroxyalkyl acrylate (or hydroxyalkyl methacrylate)
Alternatively, the curable coating composition according to claim 1, which is a polyester acrylate (or polyester methacrylate) obtained by reacting a polyester prepolymer having free hydroxyl groups with acrylic acid (or methacrylic acid). 6 (c) A polymerizable oligomer having two or more ethylenically unsaturated groups is a urethane acrylate (or 2. A curable coating composition according to claim 1, wherein the curable coating composition is a urethane methacrylate. 7. The curable coating composition according to claim 1, wherein the proportions of the essential components are (a) 2-55%, (b) 5-40% and (c) 5-93%.