JPH0363568B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to an ultraviolet curable resin composition that can be used as a surface coating agent, a sealant, and other applications for electrical, electronic parts, and other materials. [Description of Prior Art and its Problems] In recent years, demands for resource saving, energy saving, low pollution, etc. have been increasing, and in response to these demands, ultraviolet curable resin compositions have been viewed as promising. Examples of UV-curable resin compositions include those using acrylic or unsaturated polyester resins and benzoin alkyl ether as a photopolymerization initiator, as well as Lewis acid diazonium salts, Lewis acid iodonium salts, Lewis acid sulfonium salts, A method is also known in which an epoxy resin is cured by using a Lewis salt such as a Lewis acid phosphonium salt and using the Lewis salt, which is decomposed and produced by irradiation with ultraviolet rays, as a catalyst. However, UV-curable resin compositions are used, for example, as coating agents and other sealants to prevent electronic components from losing their performance due to external influences, and in these applications, adhesiveness is important. Although this is often required, the conventional ultraviolet curable resin compositions described above have insufficient adhesion to metals, ceramics, glass, etc. For example, even if the surface of ceramic is coated, it is easily peeled off. However, there was a problem in that it was not possible to exhibit sufficient performance depending on the intended use. [Technical means for solving the problem] The inventors solved the above problems and improved the original properties of the ultraviolet curable resin composition, that is, the strength, hardness, elongation, and other various properties depending on the application. As a result of intensive research in order to obtain an ultraviolet curable resin composition that has good adhesion to metals, ceramics, glass, etc. without impairing its curing properties, etc., the following invention was completed. That is, the present invention is an ultraviolet curable resin composition comprising the following components (A), (B), and (C), and is characterized in that it adheres closely to metal, ceramic, or glass. (A) 100 parts by weight of an epoxy resin containing 95 to 50% by weight of an alicyclic epoxy resin having at least one alicyclic ring, and (B) 5 to 95 parts by weight of (i) glycidyl methacrylate. % of styrene or acrylic ester or methyl methacrylate, or a mixture thereof.
10 to 40 parts by weight of any one of the copolymers blended and polymerized in a proportion of 95 to 5% by weight, and (C) a group a or group a element that releases a Lewis acid when exposed to ultraviolet light. Onium salts, 0.01-20 parts by weight. The epoxy resin (A), which is the main component of the composition of the present invention, is a conventionally known epoxy resin composition that is polymerized or crosslinked to form a coating film by irradiation with energy rays in the presence of a photopolymerization initiator. Epoxy resins used in such epoxy resin compositions include conventionally known aromatic epoxy resins, alicyclic epoxy resins, and aliphatic epoxy resins. Here, preferred aromatic epoxy resins are polyglycidyl ethers of polyhydric phenols or their alkylene oxide adducts having at least one aromatic nucleus, such as bisphenol A or its alkylene oxide adducts and epichlorohydrin. Examples include glycidyl ether and epoxy novolac resin produced by the reaction of In addition, as a preferable alicyclic epoxy resin, a polyglycidyl ether of a polyhydric alcohol having at least one alicyclic ring, or a compound containing a cyclohexene or cyclopentene ring is epoxidized with an appropriate oxidizing agent such as hydrogen peroxide. Examples thereof include cyclohexene oxide or cyclopentene oxide-containing compounds. Typical examples of polyglycidyl ethers of polyhydric alcohols having at least one alicyclic ring include glycidyl ethers produced by reacting hydrogenated bisphenol A or its alkylene oxide adduct with epichlorohydrin. Further, representative examples of cyclohexene oxide or cyclopentene oxide-containing compounds include those represented by the following formula. Preferred aliphatic epoxy resins include polyglycidyl ethers of aliphatic polyhydric alcohols or their alkylene oxide adducts, polyglycidyl esters of aliphatic long-chain polybasic acids, and homopolymers and copolymers of glycidyl acrylate and glycidyl methacrylate. Examples include diglycidyl ether of 1,4-butanediol, diglycidyl ether of 1,6-hexanediol, triglycidyl ether of glycerin, triglycidyl ether of trimethylolpropane, diglycidyl ether of polyethylene glycol, and diglycidyl ether of polypropylene glycol. Diglycidyl ether, ethylene glycol, propylene glycol, aliphatic polyhydric alcohol such as glycerin, and one or more alkylene oxides (ethylene oxide, propylene oxide)
Examples include polyglycidyl ethers of polyether polyols obtained by adding , and diglycidyl esters of aliphatic long-chain dibasic acids. Furthermore, monoglycidyl ethers of aliphatic higher alcohols, phenol, cresol, butylphenol, monoglycidyl ethers of polyether alcohols obtained by adding alkylene oidides to these, glycidyl esters of higher fatty acids, etc. may be blended as diluents. I can do it. The epoxy resin composition used in the present invention can contain these aromatic epoxy resins, alicyclic epoxy resins, or aliphatic epoxy resins alone or in a wide variety of combinations depending on the desired performance. A particularly preferable epoxy resin composition from the viewpoint of adhesion to the base material, etc. is one mainly composed of an alicyclic epoxy resin. Alicyclic epoxy resins having an epoxy group in the molecule (e.g., 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, bis(3,4-epoxycyclohexylmethyl)adipate) are preferably 95 to 50 The content is within the range of 90 to 60% by weight, more preferably 90 to 60% by weight. In addition to the above-mentioned epoxy resins, cationic polymerizable compounds such as cyclic ethers, vinyl ethers, lactones, and vinyl compounds can also be used as constituent parts of the epoxy resin composition used in the present invention. Component (B) that can be used in the present invention is a homopolymer of glycidyl methacrylate, or styrene, acrylic acid ester, methyl methacrylate, or a mixture thereof based on 5 to 95% by weight of glycidyl methacrylate.
A copolymer blended and polymerized in a proportion of ~5% by weight, or a mixture of the above-mentioned homopolymer and this copolymer can be used. A specific example of the above copolymer is Copolymer GX- from NOF Corporation.
50, #-50, #-30, #15, GS-50, etc. Component (B) is preferably 5 parts by weight per 100 parts by weight of component (A).
The amount is preferably 10 to 40 parts by weight, preferably 10 to 40 parts by weight. If it is less than 5 parts by weight, the adhesion will be poor;
If it exceeds 50 parts by weight, it is unfavorable in terms of viscosity. On the other hand, the onium salt (C) of a group a or group a element that releases a Lewis acid when exposed to ultraviolet light used in the present invention basically has the general formula [R ¹ aR ² bR ³ cR ⁴ dZ] ⁺ It is expressed as ^m [MXn+m] ^-m . In the formula, the cation is onium and Z is N≡
N, S, Se, Te, P, As, Sb, Bi, O, halogen (e.g. I, Br, Cl), R ¹ , R ² , R ³ ,
R ⁴ is an organic group which may be the same or different. a, b, c, and d are each integers of 0 to 3, and a+b+c+d is equal to the valence of Z. M is a metal or metalloid that is the central atom of the halide complex, and B, P, As, Sb,
Fe, Sn, Bi, Al, Ca, In, Ti, Zn, Sc, V,
Cr, Mn, Co, etc. X is halogen, m
is the net charge of the halide complex ion,
n is the number of halogen atoms in the halide complex ion. Component (C) is preferably 0.01 to 20% of component (A).
The amount is preferably in the range of 1 to 5 parts by weight. If it is less than 0.01 part by weight, the ultraviolet curability will be poor, and if it exceeds 20 parts by weight, it is unfavorable in terms of general properties. In addition, if necessary, the energy beam curable resin composition of the present invention may contain additives as long as they do not impair the effects of the present invention.
Olefin resins, acrylic resins, petroleum resins, alkyd resins, polyether compounds, polyether polyol compounds, vinyl acetate resins other than the cationic polymerizable substances mentioned above to improve the properties of paints or coatings. , vinyl chloride resins, butyral resins, rubber resins, vinyl alcohol resins, acid anhydride epoxy resin curing agents, pigments, dyes, and various paint additives can be used in combination. Furthermore, the resin composition according to the present invention has a US Patent No.
As proposed in No. 4156035, it is also possible to improve coating film performance and curability by blending an acrylate or methacrylate compound with a carbonyl photosensitizer or the like. [Examples] As shown in Table 1, two Examples and two corresponding Comparative Examples were formulated, and an adhesion test was conducted as shown in Table 2. In both Examples and Comparative Examples, the compound was applied to a test piece with a thickness of 40 μm.
It was applied to a test piece to a thickness of , and cured by irradiating it for 30 seconds at a irradiation distance of 15 cm using a 4 kW high-pressure mercury lamp. In the JISK5400 perforation test, 11 vertical and horizontal lines are made using a cutter knife on the coating film formed on the surface of the test piece to create 100 perforations, and tape is applied to the surface of these 100 perforations. When this tape is peeled off, it is possible to know how many squares remain.

【table】

【table】

[Table] As is clear from the results in Table 2, it can be seen that the adhesion of the Examples of the present invention is significantly improved compared to the Comparative Examples. The same applies to those using a copolymer of glycidyl methacrylate and acrylic ester as component (B). Note that there were no particular differences in other physical properties such as strength, elongation, and hardness between the Examples and Comparative Examples, so descriptions thereof will be omitted. As is clear from the description of the examples above, the ultraviolet curable resin composition according to the present invention has extremely good adhesion. [Effects of the Invention] The ultraviolet curable resin composition of the present invention can be applied to metals, ceramics, glass, etc. without impairing its original properties, i.e., strength, hardness, elongation, and other properties appropriate for the intended use. Extremely good adhesion, electrical,
It can be used as a surface coating for electronic parts and other materials, as a sealant, and for other purposes.

Claims (1)

[Scope of Claims] 1 (A) 100 parts by weight of an epoxy resin containing an alicyclic epoxy resin having at least one alicyclic ring in a range of 95 to 50% by weight; (B) (i) Styrene or acrylic acid ester or methyl methacrylate or a mixture thereof for 5 to 95% by weight of glycidyl methacrylate.
10 to 40 parts by weight of any one of the copolymers blended and polymerized in a proportion of 95 to 5% by weight, and (C) a group a or group a element that releases a Lewis acid when exposed to ultraviolet light. 0.01 to 20 parts by weight of an onium salt, and is characterized in that it adheres closely to metal, ceramic or glass.