JP2962805B2 - Curable resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION << Industrial application field >> The present invention relates to a resin composition characterized by being cured by irradiation with radiation to provide a cured film having excellent flexibility.

<< Conventional Technology >> Ultraviolet rays, radiation-curable resin compositions that are cured by irradiation with electron beam radiation have been developed and used in various applications such as printing, paint, and electrical insulation. I have.

 Its advantages are solventless and low pollution type.

The curing speed is extremely fast and the product productivity is high.

Since it cures as 100% solids, the volume change before and after curing is extremely small.

There is heat loss due to the material or no thermal effect on the material, and various paints and adhesives for plastics, paper, wood, inorganic materials, etc. have been developed.

And so on.

Radiation-curable paints, inks,
Adhesives and the like exhibit excellent properties such as adhesion, water resistance, and heat resistance.

Epoxy (meth) acrylate resins in which acrylic acid or methacrylic acid is subjected to a ring-opening reaction with an epoxy group of the epoxy resin are widely used.

<< Problems to be solved by the invention >> However, this epoxy (meta) used for general purposes
Acrylate resins have the disadvantage of being hard and brittle.

For example, when used as ink for printing on paper, a crack occurs in the ink portion when the paper after printing is bent.

Further, in the case of using as a coating material on a metal such as iron or aluminum, if a metal plate coated with the coating material is bent, the coating film is broken and cannot be processed.

<< Means for Solving the Problems >> Therefore, the present inventors have proposed such an epoxy (meth)
As a result of diligent studies to improve the disadvantages of acrylate resins and to further expand the possibilities of epoxy (meth) acrylate resins, the aliphatic cyclic epoxy resins represented by the general formula (I) have an unsaturated acid or unsaturated acid anhydride. By using a polymerizable vinyl compound having an aliphatic cyclic epoxy group obtained by reacting with, a suitable degree of flexibility is imparted and the viscosity is greatly reduced, and further, the adhesiveness, water resistance, and heat resistance are excellent. ,
In addition, a radiation-curable resin composition having extremely good flexibility has been obtained.

The present invention has been made in view of the above circumstances, and is obtained by reacting all or part of the epoxy groups of an aliphatic cyclic epoxy resin having excellent flexibility with an unsaturated acid or unsaturated acid anhydride. An object is to provide a curable resin composition containing a polymerizable vinyl compound.

<< Constitution of the Invention >> That is, the present invention provides: (a) the following general formula (I) [However, in the formula (I), X represents the following structure Y ¹ has the following structure Y ² has the following structure Y ³ has the following structure Represents

R is an aliphatic having 1 to 30 carbon atoms, alicyclic (including those having an epoxy group in the alicyclic structure moiety), or a residue obtained by removing a carboxyl group from an aromatic carboxylic acid, R ^a and R ^b and R ^{11 to} R ^m9 are a hydrogen atom or an alkyl group containing 1 to 9 carbon atoms, and can be mutually replaced with each other. c is an integer of 4 to 8, n1, n2, n3 ... nm are each 0
N1 + n2 + n3 + ..... + nm is an integer of 1 or more,
m represents an integer of 1 or more.] A polymerizable vinyl compound obtained by reacting an unsaturated acid or an unsaturated anhydride with all or a part of the epoxy groups in the aliphatic cyclic epoxy resin represented by Part (b) a vinyl compound having an ethylenically unsaturated bond 95 to
5 parts by weight (c) 0 to 10 parts by weight of a photosensitizer.

The polymerizable vinyl compound of the present invention can freely change the flexibility imparting property of the aliphatic cyclic epoxy resin represented by the general formula (I) by the amount of (a), and can obtain the polymerizable vinyl compound. Compounds can be provided with varying degrees of flexibility.

In this respect, unlike the external plasticizing method in which a plasticizer is added, there is no blade phenomenon of the plasticizer, and little deterioration in physical properties is observed.

In addition, since epoxy acrylate resins generally have high viscosity, it is necessary to use a large amount of a low-boiling acrylate ester or the like having strong skin irritation as a diluent, but the polymerizable vinyl compound of the present invention has a low viscosity. It is possible to reduce the amount of a diluent such as a low-boiling acrylic acid ester having strong skin irritation, thereby improving workability.

 Hereinafter, the present invention will be described in detail.

In the general formula (I), R is a residue obtained by removing a carboxyl group from an aliphatic, alicyclic (including those having an epoxy group) having 1 to 30 carbon atoms and having an m value or more, or an aromatic carboxylic acid.

Ra and Rb are a hydrogen atom or an alkyl group generally containing 1 to 9 carbon atoms, and this depends on the starting lactone.

For example, when ε-caprolactone is used as a raw material, RaRb
Are all hydrogen atoms.

When β-methyl-δ valerolactone is used, R
a and Rb are a methyl group and a hydrogen atom, and Ra and Rb are an ethyl group and a hydrogen atom when 3 ethyl-caprolactone is used.

 Also, c is determined by the raw material lactone.

For example, c = 5 for ε-caprolactone, c = 4 for valerolactone, and c = 7 for cyclooctanone lactone.

 nm is the number of moles of the added lactone.

For example, when no lactone is added, nm =
When adding 0 and 5 moles, n ₁ + n ₂ +... + Nm = 5.

m is the number of polyfunctional alicyclic esters and corresponds to the number of functional groups of the starting carboxylic acid and acid anhydride used. Examples of the aliphatic cyclic epoxy resin represented by the general formula (I) include, when m is 1, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate-modified caprolactone (III) and 3 Modified trimethylcaprolactone of 1,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (I
V), (VI) 'and valerolactone-modified 3,4-epoxy-6-methylcyclohexylmethyl-3,4-epoxy-6-methylcyclohexanecarboxylate (V);
(V) 'and the like.

Further, in the formula (I), when m is 2, the following formula [Where X ¹ is the following structure —O— (CH ₂ ) ₅ —CO— R ¹ is the following structure And n ₁ and n ₂ represent integers in which n ₁ + n ₂ is 1 or more.
・ (VI) [Where X ¹ is the following structure: —O— (CH ₂ ) ₅ —CO—; R ² is the following structure: n ₁ and n ₂ represent integers in which n ₁ + n ₂ is 1 or more]
· (VII) In the formula (I), when m is 4, the following formula [However, in the formula (VIII), X ¹ is the following structure n1, n2, n3, and n4 are each an integer of 0 or more, and n1 + n2 + n3 + n
4 represents an integer of 1 or more.] In the formula (I), when m is 6, the following formula [However, in the formula (IX), X ¹ has the following structure: —O— (CH ₂ ) ₅ —CO—; R ² has the following structure: [Where, in the formulas (III) to (IX), Y ^e is And MY ^e is , N1, n2, n3 ... n6 are each an integer of 0 or more, and n1 + n2
+ N3 + ... + n6 represents an integer of 1 or more].

Further, a method for synthesizing the aliphatic cyclic epoxy resin of the general formula (I) will be described below.

 First, it is produced by the following series of reactions.

[However, in the formula [B], X represents the following structure Y ¹ has the following structure Y ² has the following structure Y ³ has the following structure Represents) or <Reaction-5> An aliphatic cyclic epoxy resin represented by the formula (I), which is a main substance in the curable resin composition of the present invention, is produced by the following oxidation reaction.

In the dehydration esterification reactions of <Reaction-2> and <Reaction-3>, a carboxylic acid and an alcohol can be collectively charged and reacted.

The reaction can be carried out at a temperature of 150-250 ° C. At the beginning of the temperature rise, a large amount of water is distilled off, and the temperature does not rise more than a predetermined value even if heating is performed more than necessary.

The reaction proceeds, and as the amount of dehydrated water increases, the temperature of the reaction system also increases.

Since the acid value in the system decreases as the reaction proceeds, this can be used as a standard.

The molar ratio of carboxylic acid and alcohol to be charged is 1.0 mol or more of alcohol to 1 mol of carboxylic acid. This is because the excess of alcohol causes the acid value in the system to decrease more rapidly.

However, if the amount is more than the required amount, it takes much time for removal after the reaction is completed, which is not desirable.

Alternatively, when an acid anhydride is used in <Reaction-2> and <Reaction-3>, these reactions are an addition reaction of an acid anhydride and an alcohol and a dehydration esterification reaction of a carboxylic acid and an alcohol.

 The reaction proceeds even at relatively low temperatures.

However, for industrial reaction, the temperature is 100-250 ° C.
The reaction between the acid anhydride and the alcohol proceeds at a relatively low temperature.

However, in the reaction between carboxylic acid and alcohol, it is advantageous to continuously remove water from the reaction system by a dehydration reaction. Therefore, the temperature is preferably 100 ° C. or lower under normal pressure. Above 250 ° C., decomposition of the lactone oligomers and coloring of the product are extremely undesirable.

Next, <Reaction-1> and <Reaction-4> are lactone modification reactions.

In these reactions, a predetermined lactone is added to an ester or alcohol, and a titanium catalyst or a tin catalyst is added in an amount of 0.1 to 10,000 ppm.
It can be added and reacted at 150-250 ° C.

If the amount of the catalyst is less than 0.1 ppm, the reaction is slow, and even if it is added at 10,000 ppm or more, a large effect does not appear.

When the temperature is lower than 150 ° C., the speed is low.

Furthermore, when the compound of the general formula [B] thus obtained is epoxidized, an aliphatic cyclic epoxy resin of the general formula (I) is obtained <Reaction-5>.

This epoxidation is performed using a peracid or hydroperoxide.

As the epoxidizing agent for epoxidation, a peracid or various hydroperoxides can be used.

For example, the peracids include formic acid, peracid, perpropionic acid, perbenzoic acid, trifluoroperacetic acid and the like.

Hydroperoxides include hydrogen peroxide, tertiary butyl hydroperoxide, cumene peroxide, metachloroperbenzoic acid and the like. At the time of epoxidation, a catalyst can be used if necessary.

For example, in the case of peracid, an alkali such as sodium carbonate or an acid such as sulfuric acid can be used as a catalyst.

In the case of hydroperoxides, a catalyst effect is obtained by using a mixture of tungstic acid and caustic soda with hydrogen peroxide, an organic acid with hydrogen peroxide, or molybdenum hexacarbonyl with tertiary butyl hydroperoxide. Can be.

[Reaction Conditions] The epoxidation reaction is performed by adjusting the presence or absence of a solvent and the reaction temperature according to the apparatus and the physical properties of the raw materials.

The reaction temperature range that can be used is determined by the reactivity of the epoxidizing agent used.

Regarding peracetic acid, which is a preferred epoxidizing agent, 0
A range of -70 ° C is preferred.

If the temperature is lower than 0 ° C., the reaction is slow, and if the temperature is higher than 70 ° C., decomposition of peracetic acid occurs.

In the case of tertiary butyl hydroperoxide / molybdenum dioxide diacetylacetonate, which is an example of hydroperoxide, the temperature is 20 ° C. to 150 ° C. for the same reason.
Is preferred.

The solvent can be used for the purpose of lowering the viscosity of the raw material, stabilizing the epoxidizing agent by dilution, and the like.

In the case of peracetic acid, an aromatic compound, an ether compound, an ester compound or the like can be used.

In particular, ethyl acetate or xylene is a preferred solvent.

For example, in the case of a peracid, an alkali such as sodium carbonate or an acid such as sulfuric acid may be used as a catalyst.

The charged molar ratio of the epoxidizing agent to the unsaturated bond can be changed depending on the purpose such as how much the unsaturated bond is desired to remain.

When a compound having a large number of epoxy groups is intended, the epoxidizing agent is preferably added in an equimolar amount or more based on the unsaturated group.

However, due to economics and the side reactions described below,
It is usually disadvantageous to exceed 10 moles, and in the case of peracetic acid, 1 to 5 moles is preferable.

Depending on the conditions of the epoxidation reaction, the substituent in the raw material undergoes a side reaction with the epoxidizing agent at the same time as the epoxidation of the double bond, resulting in a modified substituent, which is contained in the target compound.

However, a small amount of by-products may be mixed in the obtained product, which may adversely affect the hue or the acid value. In order to prevent this, at least one of the following additives can be added.

Phosphoric acid, phosphoric acid-potassium, phosphoric acid-sodium, ammonium hydrogen phosphate, pyrophosphoric acid, potassium pyrophosphate, sodium pyrophosphate, sodium 2-ethylhexyl pyrophosphate, potassium 2-ethylhexyl pyrophosphate, sodium 2-ethylhexyl tripolyphosphate , Potassium 2-ethylhexyl tripolyphosphate, 2-
Sodium ethylhexyl tetrapolyphosphate and potassium 2-ethylhexyl tetrapolyphosphate.

The addition amount is 10 ppm to 10,000 ppm in the reaction crude liquid, preferably 50 p.
pm to 1000 ppm.

The effect of these additions is generally considered to be the action of chelating and inactivating metals mixed in from the reactor or raw materials.

[Purification] The product can be separated by various methods.

The crude reaction solution obtained can be directly used as a product by distilling off the solvent and the like.

The conditions for removing low boiling point are 50 to 200 ° C, preferably 80 to 160 ° C.

Further, the reaction can be performed by adjusting the degree of reduced pressure according to the boiling point of each solvent.

Also in this reaction, trace impurities are generated, and it is preferable to wash with water to remove these.

In washing with water, an aromatic compound such as benzene, toluene, or xylene, a hydrocarbon such as hexane, heptane, or octane, or an ester such as ethyl acetate or butyl acetate can be used in the reaction crude liquid.

The washing amount is 0.1 to 10 times, preferably 1 to 5 times the reaction crude liquid vol.
It is twice.

It is also an effective method to remove a trace amount of acid by washing with an aqueous alkali solution and further with water. Examples of the alkaline aqueous solution to be used include NaOH, KOH, K ₂ CO ₃ , Na ₂ C
Aqueous solutions of alkaline substances such as O ₃ , NaHCO ₃ , KHCO ₃ , NH ₃ and the like can be used.

The concentration at the time of use can be freely selected within a wide range.

Alkaline water washing and water washing are 10 to 90 ° C, preferably 10 to 90 ° C.
It is better to carry out in the temperature range of 50 ° C.

After separating the washed liquid into two layers, the organic acid is taken out,
The product can be taken out by low boiling.

The low boiling point removal is 50 to 200 ° C, preferably 80 to 160 ° C, and can be performed by adjusting the degree of reduced pressure according to the boiling point of each solvent.

The reaction can be carried out in any manner, continuous or batch.

In the case of a batch system, a method in which raw materials and additives are charged into a reactor and then an epoxidizing agent is added dropwise is preferable.

When this is washed with water, it is separated into two layers after washing with water, and the organic layer is evaporated with an evaporator to produce a product.

In the case of continuous operation, the raw material, the epoxidizing agent and the additive can be continuously charged into the reactor and continuously extracted. The reactor may be of any type, such as a complete mixing tank or a piston flow type.

The proportion of the aliphatic cyclic epoxy resin represented by the general formula (I) in the polymerizable vinyl compound (a) used in the present invention is 97 to 5 parts by weight, preferably 97 to 30 parts by weight in total 100 parts by weight.
Parts by weight.

The reason is that if the amount is too large, the intended flexibility cannot be obtained, and if the amount is too small, the resin becomes too soft.

The polymerizable vinyl compound (a), which is one of the components in the curable resin composition of the present invention, is obtained by the above-mentioned epoxy resin and unsaturated acid or unsaturated acid anhydride in the presence or absence of a ring-opening catalyst for an epoxy group. It is obtained by a heating reaction in the presence of a polymerization inhibitor, a solvent or a reactive diluent, if necessary, and a hydroxyl group formed by ring opening of an epoxy group always exists.

In the curable resin composition of the present invention, the polymerizable vinyl compound thus obtained is 5 to 95 parts by weight, preferably 20 to 80 parts by weight, and the vinyl compound having an ethylenically unsaturated bond 95 to 95 parts by weight. 5 parts by weight, preferably 80 to 20 parts by weight, are added. When the amount of the lactone-modified epoxy (meth) acrylate resin is small, adhesion, heat resistance, and flexibility cannot be sufficiently imparted to the cured coating film. When the amount is too large, handling is difficult due to high viscosity and curing speed. May be slow.

The vinyl compound having an ethylenically unsaturated bond used in the present invention refers to an acrylate or methacrylate compound represented by the following general formula (X), styrene, N-vinylpyrrolidone, or the like. It is a low-viscosity liquid compound having a double bond.

A typical acrylic or methacrylic acid ester is as follows.

Monofunctional (meth) such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, acrylic acid ester of tetrahydrofurfuryl alcohol, and phenoxyethyl acrylate
Acrylic acid ester, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate,
Bifunctional (meth) acrylates such as propylene glycol diacrylate, propylene glycol dimethacrylate, and neopentyl glycol diacrylate;
Trifunctional (meth) acrylates such as trimethylolpropane triacrylate and pentaerythritol triacrylate are used.

These vinyl compounds having an ethylenically unsaturated bond are used alone or in combination of two or more.

The term "radiation" in the present invention refers to all radiation sources that generate free radicals and induce addition polymerization of vinyl bonds.

The actinic radiation preferably has a wavelength of 200 to 7500 A, and preferably has a wavelength of 2000 to 4000 A.

 A useful type of actinic radiation here is ultraviolet light.

Other forms of actinic radiation include those coming from sunlight, artificial light sources, carbon arc lamps, mercury vapor lamps, and the like.

A preferred electron beam system is one in which an electron curtain is emitted directly from a linear cathode.

The radiation curable resin composition of the present invention may contain an effective amount of a photosensitizer when photocuring the composition. Usually this amount is about 0.01 to 10% by weight of the resin composition, preferably about 0.1%.
~ 5% by weight.

These photosensitizers and their curing process are well known in the art.

 One example is as follows.

For example, benzophenone, acetophenone benzyl,
Benzyl dimethyl ketone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether,
Dimethoxyacetophenone, diethoxyacetophenone, dimethoxyphenylacetophenone, diphenyldisulfide, α-alkylbenzoin and the like.

These photosensitizers can also contain a synergist, for example, a tertiary amine, to enhance the conversion of the light absorption energy into a polymerization initiation free radical.

When the curable composition is cured by irradiation with an electron beam, it is not always necessary to add a sensitizer.

The resin composition of the present invention may contain various additives such as a thermal polymerization inhibitor, a surfactant, an ultraviolet absorber, a matting agent, a thixotropic agent, a dye and a pigment, as desired.

Furthermore, various thermoplastic resins, thermosetting resins, and the like can be blended.

The composition of the present invention can be cured by being applied as a thin film on a substrate.

As a method of forming a thin film, spraying, brushing, dipping, roll coating and the like are used.

The curing is preferably performed in an inert gas (for example, nitrogen gas) atmosphere, but the curing can also be performed in an air atmosphere.

The cured composition according to the present invention can be used in various coating fields such as ink, plastic paint, paper printing, film coating, metal coating, furniture coating, ERP, lining, and also in insulating varnish, insulating sheet, laminated board, printed circuit board in electronics field. , Resist ink, semiconductor encapsulant, and many other industrial fields.

[Examples] Hereinafter, the present invention will be described in more detail with reference to Examples. In the examples, parts represent parts by weight.

Synthesis Example 1 Araldite 6071 which is a bisphenol A type epoxy resin (trade name of epoxy resin manufactured by Ciba, epoxy equivalent 450- 930 parts of 500) and 0.54 part of hydroquinone monomethyl ether as a polymerization inhibitor were added, the reaction temperature was maintained at 85 ± 85 ° C. while flowing air, and 144 parts of acrylic acid and 1.07 part of triethylamine as a catalyst were added dropwise in about 2 hours.

After the completion of the dropping, the mixture is allowed to react at about 90 ° C. for about 24 hours to obtain an acid value of 3.38 mgKOH / g, oxirane oxygen 0.09%, and a viscosity of about 2,000,000 cp.
/ 25 ° C resin was obtained.

Synthesis Example 2 In the same apparatus as in Synthesis Example 1, 730 parts of an epoxy resin represented by the general formula (I) obtained by modifying 504 parts of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate with 228 parts of caprolactone, Hydroquinone monomethyl ether (0.44 part) was charged, the reaction temperature was maintained at 85 ± 5 ° C. while flowing air, and 144 parts of acrylic acid and 0.96 part of triethylamine were added dropwise in about 2 hours.

After the completion of the dropping, the mixture is reacted at about 90 ° C. for about 24 hours to obtain an acid value of 4.20 mgKOH / g, oxirane oxygen of 0.09%, and a viscosity of about 50,000 cp / g.
A resin at 25 ° C. was obtained.

Synthesis Example 3 Using the same apparatus as Synthesis Example 1 [Where X ¹ is the following structure: —O— (CH ₂ ) ₅ —CO—; R ² is the following structure: Y ^e has the following structure Using the same reaction as above, acid value 1.20 mg KO
A resin having H / g, oxirane oxygen of 2.18%, and a viscosity of about 300,000 cp / 25 ° C. was obtained.

Synthesis Example 4 Using the same apparatus as Synthesis Example 1 [However, in the above formula, X ¹ represents the following structure —O— (CH ₂ ) ₅ —CO—, and n 1, n 2, n 3 and n 4 represent n 1 + n 2 + n 3
+ N4 = 3 Y ^e has the following structure Using the same reaction as above, the acid value was 4.35 mg KO.
A resin having an H / g of 0.12% of oxirane oxygen and a viscosity of about 2 million cp / 25 ° C. was obtained.

Examples 1 and 2 50 parts of each of the polymerizable vinyl compounds synthesized in Synthesis Examples 2 and 3, 30 parts of trimethylolpropane triacrylate (hereinafter abbreviated as TMPTA), 10 parts of pentaerythritol triacrylate, and N-vinylpyrrolidone (hereinafter referred to as N-vinylpyrrolidone) 10 parts of NVP) and 2 parts of benzyl dimethyl ketal (Irgacure 651 manufactured by Ciba) as a photoinitiator were mixed and applied on an iron substrate to a thickness of 15 μm, and a high-pressure mercury lamp (output: 80 w / c)
m) The lower 10cm is cured at a belt speed of 2m / min.
The physical properties of the coating film were evaluated.

Examples 3 and 4 20 parts of TMPTA, 20 parts of 1,6-hexanediol diacrylate (hereinafter abbreviated as HDDA), 20 parts of NVP, 10 parts of NVP, and 2 parts of benzoin isobutyl ether based on 50 parts of the polymerizable vinyl compound synthesized in Synthesis Examples 2 and 3. Were mixed, and the same evaluation as in Examples 1 and 2 was performed.

 Table 2 shows the results.

Examples 5, 6, 7 Based on 50 parts of the polymerizable vinyl compound synthesized in Synthesis Examples 2, 3, and 4, 20 parts of HDDA, 20 parts of dipentaerythritol hexaacrylate, 10 parts of NVP, and benzyl dimethyl ketal 2
And the same evaluation as in Examples 1 and 4 was performed.

 Table 3 shows the results.

Comparative Examples 1 to 3 Instead of the polymerizable vinyl compound synthesized in Synthesis Examples 2 and 3, the epoxy acrylate resin synthesized in Synthesis Example 1 was used, and otherwise the same blending conditions and curing conditions as in Examples 1, 3, and 5 were used. Was evaluated for physical properties. Table 4 shows the results.

As shown above, when the polymerizable vinyl compound of the present invention was used, the flexibility was clearly improved.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ identification code FI C09D 163/10 C09D 163/10 (58) Fields investigated (Int. Cl. ⁶ , DB name) C08F 290/00-290/14 C08F 299/00-299/08 C08G 59/00-59/72 C09D 1/00-201/10

Claims (1)

(57) [Claims] (1) The following general formula (I) [However, in the formula (I), X represents the following structure Y ¹ has the following structure Y ² has the following structure Y ³ has the following structure Represents R is an aliphatic having from 1 to 30 carbon atoms, (including the alicyclic structure moiety having an epoxy group) alicyclic, or residue obtained by removing a carboxyl group from an aromatic carboxylic acid, R ^a and R ^b and
R ^{11 to} R ^m9 are a hydrogen atom or an alkyl group containing 1 to 9 carbon atoms, and can be mutually replaced with each other. c is an integer of 4 to 8, n1, n2, n3 ... nm are each 0
N1 + n2 + n3 + ..... + nm is an integer of 1 or more,
m represents an integer of 1 or more.] A polymerizable vinyl compound obtained by reacting an unsaturated acid or unsaturated acid anhydride with all or a part of the epoxy groups in the aliphatic cyclic epoxy resin represented by Part (b) a vinyl compound having an ethylenically unsaturated bond 95 to
5 parts by weight (c) 0 to 10 parts by weight of a photosensitizer.