JPS63221114A - Photocurable resin composition - Google Patents

Abstract

PURPOSE:To obtain a photocurable resin composition excellent in adhesion to glass, plastic, metal, etc., comprising a benzyloxymethylacrylamide of a specified formula and a photopolymerization initiator. CONSTITUTION:A photocurable resin composition comprising a benzyloxyme thylacrylamide compound of the formula (wherein R1 is H or CH3) and a photo polymerization initiator (e.g., 1-hydroxycyclohexyl phenyl ketone). This resin composition can cure by irradiation with an actinic radiation such as ultraviolet rays or electron beams and is useful as a coating agent for surface modification or an adhesive, or for inks for printed wiring boards, etc.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a photocurable resin composition that is cured by irradiation with active energy rays such as ultraviolet rays and electron beams. glass, plastic,
It is used as a surface-modifying coating agent or adhesive for metals, etc., or as an ink for printed wiring boards.

[Conventional technology]

In general, photocurable resin compositions include acrylic, unsaturated polyester, and polyester acrylic! Ize 1
1 〒 -；-1! Nof h II 11th work
It consists of a prepolymer such as a urethane/III type or urethane acrylic type, an acrylic reactive diluent, and a photopolymerization initiator. Among these, JP-A-57-12
Publication No. 4730 describes a water-soluble photocurable resin composition containing an ether-type clamp of polyvinyl alcohol, N-methylol acrylamide or N-methylol methacrylamide, and a polyhydric alcohol, and a photopolymerization initiator. has been done. Furthermore, JP-A-61-151213 describes a photocuring resin composition containing an ester of acrylic acid and an aromatic alcohol, a polymer containing isobutyl methacrylate, and a photopolymerization initiator. .

[Problem that the invention seeks to solve]

Conventional photocurable resin compositions generally have poor adhesion to surfaces such as glass, plastic, and metal. In particular, when trying to obtain a hard coating film by applying an ultraviolet curable resin composition to a polyester film, the purpose is almost impossible to achieve because of poor adhesion. Regarding the use of photocurable resin compositions in solder resist inks for printed wiring boards that require hardness, heat resistance, solvent resistance, and chemical resistance, conventional photocurable resin compositions are Since it has poor adhesion compared to thermosetting epoxy resin compositions, it can hardly be used in industrial solder resist inks, and as expected from the lack of adhesion, Conventional photocurable resin compositions are not necessarily sufficiently suited as adhesives for bonding substrates such as glass, plastic, and metal.

The present invention provides a new photocurable resin composition that does not have the above problems pointed out in conventional photocurable resin compositions.

[Means for solving problems]

The photocurable resin composition according to the present invention is composed of a monomer represented by the following CI3 formula and a photopolymerization initiator.

(In the formula, R1 is a hydrogen atom or a methyl group.) The monomer (1) used in the present invention is an N-methylolated product of acrylamide or methacrylamide (hereinafter abbreviated as (meth)acrylamide). and benzyl alcohol through ether type condensation.

For example, an N-methylolated product of (meth)acrylamide and benzyl alcohol are combined in the presence of an acid catalyst with benzene,
The reaction is carried out in an azeotropic solvent such as toluene at a temperature of 80 to 120°C to perform dehydration and etherification. After neutralizing the reaction product, the catalyst is removed by washing with water, etc., and then the solvent is removed by means such as vacuum distillation or azeotropic distillation. By performing this, the desired monomer (Il) can be obtained.

Monomer (1) produced by dehydration etherification as described above is a colorless, odorless, low viscosity, low volatility liquid, with a specific gravity of 1.10 or more and a refractive index of 1.52 or more, The light curing speed is fast and the shrinkage rate is low during curing, so the synergistic effect with the cohesive force of acid amide bonds makes it suitable for glass, metal,
It is believed that it exhibits excellent adhesion to non-absorbent surfaces such as polyester films.

By the way, dialkylacrylamide such as dimethylacrylamide, or N-methylolacrylamide such as N-methoxymethylacrylamide, N-ethoxymethylacrylamide, N-butoxymethylacrylamide, N-isobutoxymethylacrylamide,
A resin composition whose main component is an etherified product of 1 to C1 monohydric alcohol has a cured film that lacks adhesion to the above-mentioned substrate, exhibits tackiness, and has a low refractive index. Furthermore, resin compositions whose main components are etherified products of N-methylol acrylamide and polyhydric alcohols such as ethylene glycol, propylene glycol trimethylol propane, and pentaerythritol often have high viscosity or lack compatibility. Also, the adhesion is not sufficient.

On the other hand, the monomer [I] of the present invention is not simply an etherified product as described above, but has both an acid amide bond and an aromatic nucleus, so the glass transition temperature of the polymerized and cured polymer is high. Therefore, the cured film does not exhibit tackiness and has a high refractive index.

In addition, monomer [I] can be styrene, methyl methacrylate,
Butyl methacrylate, butyl acrylate, acrylic acid-
It is blended with 2-ethylhexyl, acrylic acid, methacrylic acid, etc. as a crosslinking monomer, and further mixed with a solvent such as toluene, xylene, butanol, and an initiator such as benzoyl peroxide, azobisisobutyronitrile, etc., and then heated. It is also possible to polymerize and make a thermosetting resin composition, but in this case, benzyl alcohol is desorbed from heating at 100°C or higher, and the characteristics of monomer (1) are impaired, resulting in poor adhesion, hardness, etc. In this respect, the same effect as the present invention cannot be achieved.

The photocurable resin composition of the present invention contains a photopolymerization initiator in addition to the above-mentioned monomer [I]. Examples of the photopolymerization initiator include benzoin, benzoin isobutyl ether,
Benzyl, benzophenone, benzyl dimethyl ketal, hydroxycyclohexylphenyl ketone, jetoxyacetophenone, 2-hydroxy-2-methylpropiophenone, Michler's ketone, chlorothioxanthone can be used. These photopolymerization initiators can be dibutylamine, triethylamine, or
In combination with a sensitizer such as diethylaminoethyl methacrylate, it is blended into the composition in a range of 0.01 to 10% by weight.

The photocurable resin composition of the present invention is basically composed of the above-mentioned monomer (1) and a photopolymerization initiator. It is possible to add other types of monomers as third components.

In this case, the monomers include hydroxyethyl acrylate, 2-ethylhexyl acrylate, phenoxyethyl acrylate, triloxyethyl acrylate, phenoxypolyethylene glycol acrylate, nonylphenol ethylene oxide adduct acrylate, benzyl acrylate, cyclohexyl acrylate, dicyclopentenyl In addition to acrylic esters and/or methacrylic esters such as acrylate, 2-hydroxy-3-phenoxypropyl acrylate, dibrom-t-butylphenyl acrylate, tetrahydrofurfuryl acrylate, and acryloyloxyethyl phosphate, styrene, vinyltoluene, and vinyl acetate. etc. are included.

In addition, if it is desired to further improve the hardness, heat resistance or chemical resistance of the cured film obtained from the composition of the present invention, N
- Ether-type condensates of methylol (meth)acrylamide and polyhydric alcohols can be mixed. The polyhydric alcohol components of the ether type condensate include ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, butanediol, hexanediol, cyclohexanediol, bisphenol A ethylene oxide adduct, bisphenol F ethylene oxide adduct, and glycerin. , glycerin alkylene oxide adduct, trimethylolpropane and its alkylene oxide adduct, pentaerythritol, dipentaerythritol, pentose, hexose, and the like. In addition, esters of these polyhydric alcohol components and acrylic acid, such as ethylene glycol diacrylate, polyethylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, tris (acryloyloxyethyl) isocyanurate You may mix polyfunctional acrylic esters such as.

To adjust the viscosity, curability, flexibility of the cured film, etc. of the photocurable resin composition of the present invention, dialkylacrylamide, N-methoxymethylacrylamide, N-ethoxymethylacrylamide, N-isobutoxymethylacrylamide, N-butoxymethylacrylamide etc.
It is effective to mix a small amount into the resin composition of the present invention.

Furthermore, in order to impart even higher heat resistance, solvent resistance, and mechanical strength to the cured film obtained from the resin composition of the present invention, various acrylic prepolymers with high molecular weights can be blended. Examples of such acrylic prepolymers include so-called epoxy acrylic prepolymers obtained by esterifying bisphenol type, Talesol novolak type, glycidylamine type, and alicyclic type epoxy resins with acrylic acid; polyether polyols, polyester polyols; A polyurethane acrylic prepolymer obtained by reacting a diisocyanate with an acrylic acid ester having a hydroxyl group such as hydroxyethyl acrylate: A dibasic acid such as adipic acid or phthalic anhydride with an equivalent molar amount of ethylene glycol, trichloride, etc. Polyester polyol obtained by reacting polyhydric alcohol such as methylolpropane,
An example is a polyester acrylic prepolymer obtained by reacting acrylic acid.

In addition to the monomers and prepolymers listed above, epoxy resins, ketone resins, phenolic resins,
Various synthetic resins such as silicone resins can be mixed, and like ordinary photocuring resin compositions, the resin composition of the present invention does not require pigments, stabilizers, antioxidants, surfactants, etc. Can be mixed accordingly.

Coating methods such as roll coater 1 brush coating and screen printing can be employed for the photocurable resin composition of the present invention, and spray coating can be employed if diluted with a solvent such as toluene or ethyl acetate. You can also do it. Furthermore, since the resin composition of the present invention has excellent adhesion to glass, plastics, metals, etc., it can naturally be used as a photocurable adhesive, and if its high refractive index feature is utilized,
It can also be applied to applications related to optical lenses. Other fields include ink, paper printing, resist ink for printed circuit boards, semiconductor encapsulants, surface modification coating agents for plastics, films, woodworking, metals, etc., and insulating varnishes.

The photocurable resin composition of the present invention can be used.

〔Example〕

Next, the resin composition of the present invention will be explained in more detail with reference to Examples, but first, a synthesis example of the monomer (I) used in the present invention will be shown.

Synthesis Example 1 Acrylamide 426g, paraformaldehyde 190
Disperse g in 860 g of benzyl alcohol, add a small amount of caustic soda to make p) 19.5, and disperse 0.1 g of cuperone.
was added, and the mixture was reacted for 1.5 hours at 50 to 55°C while sucking air. Next, cyanic acid was added to this to lower the pH to 4, and 0.2 g of hydroquinone and 465 g of toluene were added to perform dehydration and etherification at 100 to 105°C.

After that, it was neutralized at 60°C using a caustic soda aqueous solution,
After that, the water was washed twice with sodium sulfate solution, 0.2 g of hydroquinone monomethyl ether was added, water was added under reduced pressure while blowing a small amount of air, and toluene and unreacted benzyl alcohol were distilled off. By filtering and separating, 1090 g of liquid benzyloxymethyl acrylamide with a hue of APHA30 was obtained. The viscosity of this product is 55
cps (25℃), specific gravity a? 1.1022, and the refractive index n%' was 1.5409. For reference, triloxyethyl acrylate, which is an acrylic ester of triloxyethanol, has a viscosity of 17 cps (25°C) and a specific gravity of a
? 1.086, and the refractive index n%' is 1.5141.

Synthesis Example 2 124 g of benzyl alcohol, 75 g of toluene, 0.1 g of hydroquinone monomethyl ether, 5 g of L-oxalic acid
101 g of N-methylolacrylamide was added little by little while blowing air into the solution, and the reaction was carried out while azeotropically dehydrating the solution.

After the addition was completed, the mixture was heated under reflux for 2 hours, and then neutralized at 60°C by adding an aqueous solution of caustic soda.

Thereafter, the mixture is washed twice with sodium sulfate solution, and toluene and unreacted benzyl alcohol are azeotropically distilled off while blowing air and heated sewage water is added dropwise.Finally, after dehydration under reduced pressure, the remaining oil is filtered. 1 g and 3 g of colorless liquid benzyloxymethylacrylamide was obtained.

Example 1 1-hydroxycyclohexyl phenyl ketone was added to benzyloxymethyl acrylamide as a photopolymerization initiator.
% melted material was applied to a glass plate, tinplate plate, and polyester film at a thickness of 30μ, and 80w/
When these were placed on a belt conveyor running at a speed of 4 m/min at a distance of 15 cm below the cm U lamp and exposed once, the coated surface immediately lost its fluidity and tackiness, and a total of 4 exposures were carried out. A coating film having a pencil hardness of H was obtained. The coating film thus obtained showed such adhesion that it did not peel off even when subjected to a cross-cut adhesive tape peeling test, the coating film on the tin plate did not peel off even when bent, and the coating film on the polyester film did not peel off even when rubbed. It won't peel off.

Example 2 90 parts of benzyloxymethylacrylamide.

A photocurable resin composition consisting of 10 parts of N-butoxymethylacrylamide and 2 parts of 1-hydroxycyclohexylphenyl ketone had a hue of APHA30. Viscosity 50cps/2
At 5°C, there was almost no odor and the refractive index n%' was 1.5322. This resin composition was applied to a glass plate to a thickness of 30 μm, placed on the same belt conveyor as in Example 1, and exposed five times to obtain a coating film with a pencil hardness of B. This coating film does not peel off even when subjected to a cross-cut adhesive tape peeling test.

Example 3 A photocuring resin composition consisting of 50 parts of benzyl oxydimethyl acrylamide, 50 parts of glycerol tripropoxy triacrylate, and 2 parts of benzyl dimethyl ketal was
Painted on a steel plate with a thickness of 30μ.

By exposing this 5 times in the same manner as in Example 2,
A coating film with a pencil hardness of 3H was obtained. This coating film does not peel off even when subjected to a cross-cut adhesive tape peeling test.

Example 4 Consisting of 40 parts of diacrylic ester of Epikote 828 (an epoxy resin manufactured by Shell Chemical Co., Ltd.), 30 parts of glycerol tripropoxy triacrylate, 30 parts of benzyloxymethylacrylamide, and 2 parts of 2-hydroxy-2-methylpropiophenone. The photocurable resin composition was applied to a glass plate to a thickness of 30 μm, and exposed to light five times in the same manner as in Example 2. The coating film thus obtained does not peel off even when subjected to a cross-cut adhesive tape peeling test.

Claims (1)

[Claims] 1. A monomer represented by the following formula [I]▲There are mathematical formulas, chemical formulas, tables, etc.▼[I] (in the formula, R^1 is a hydrogen atom or a methyl group) and light A photocuring resin composition containing a polymerization initiator.