JPH05230158A - Photo-setting resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition, containing a specific photopolymerizable resin prepared from a novolak type epoxy resin and capable of providing a cured product having excellent surface hardness and heat resistance and moderate flexibility even' if the amount of a photopolymerization initiator is small or the light irradiation time is short. CONSTITUTION:The objective composition is obtained by initially reacting a novolak type epoxy resin of the formula [(n)>=2; R<1> is H or CH3; R<2> is H, CH3 or halogen] with an unsaturated monobasic acid [preferably (meth)acrylic acid] and a polybasic acid (preferably a >=8C dibasic acid such as 1,18- octadecanedicarboxylic acid), then converting the resultant reactional product through an ester bond into a polymer, further reacting the obtained reactional product with a polyfunctional (meth)acrylate having NCO group and >=2 photopolymerizable double bonds together, providing a photopolymerizable resin and blending the photopolymerizable resin with a photopolymerization initiator. The polyfunctional (meth)acrylate is obtained by reacting, e.g. isophorone diisocyanate with pentaerythritol triacrylate.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention is capable of forming a cured film having excellent surface hardness, heat resistance, and appropriate flexibility, and is highly water-soluble and capable of being photopolymerized. The present invention relates to a resin composition.

[0002]

BACKGROUND OF THE INVENTION Photosensitive polymers were initially used as resists for etching, photosensitive materials for printing plate making, etc., but in recent years, they have been used in the fields of fine processing of wiring boards and paints, inks and adhesives. It started to come. A resin composition that is cured by ultraviolet rays (hereinafter simply referred to as "light") has many advantages such as energy saving by shortening heating or drying time and pollution-free by reducing the amount of organic solvent used. The research and development corresponding to the use of is actively carried out.

The most strongly required performance of the photopolymerizable resin is an increase in the surface hardness and photosensitivity of the cured product. The photopolymerization initiator, which is indispensable for the photopolymerization reaction, is toxic, causes yellowing of the resin, deteriorates storage stability, and is expensive. It is very important in the photopolymerizable resin to increase the photosensitivity so as to reduce the amount of light.

As a means for increasing the photosensitivity of epoxy acrylates, urethane acrylates, polyester acrylates, etc., which have been conventionally used as photopolymerizable resins, a low molecular weight polyfunctional (meth) acrylate is blended with the resin or the resin is used. There is a method of increasing the number of photopolymerizable double bonds (vinyl group etc.) in the resin composition by reacting with polyfunctional (meth) acrylate. However, simply increasing the number of photopolymerizable double bonds results in unbalanced properties such that the physical properties after photocuring are solid but weak. For this reason, it is necessary to first increase the molecular weight of the photocurable resin and then to introduce as many photopolymerizable double bonds as possible according to the molecular weight.

When the above-mentioned molecular design is actually carried out, it is relatively easy to increase the molecular weight of polyester acrylate or urethane acrylate, but the amount of photopolymerizable double bond that can be introduced into one molecule is small, and the epoxy resin is not In the case of acrylate, the photopolymerizable double bond can be introduced by utilizing the reaction of the epoxy group, but the photopolymerizable double bond can be introduced in one molecule even with the most polyfunctional novolac type epoxy resin. The number of bonds was about 10, and it was difficult to design a molecule so that a high-performance cured product could be obtained in a short irradiation time.

[0006]

In consideration of the above circumstances, the present inventors use a novolac type epoxy resin as a starting material to produce a photopolymerizable resin having a sufficient molecular weight and a photopolymerizable double bond. As a result, a study on a photo-curable resin composition with high photosensitivity that can obtain a cured product having excellent surface hardness, heat resistance and appropriate flexibility even with a short irradiation time has already been disclosed (pending application). .. The present invention has two objectives of improving the performance of the photocurable resin composition and making the photopolymerizable resin water-soluble as an added value.

[0007]

The present invention provides a photocurable resin composition of the formula

[0008]

[Chemical 2]

(However, n ≧ 2, R ¹ = H or C
H ₃ , R ² = H, CH ₃ , or halogen), a novolak type epoxy resin is reacted with an unsaturated monobasic acid and a polybasic acid, and the reaction product (I) is polymerized through an ester bond. In addition, the gist is to contain a photopolymerizable resin and a photopolymerization initiator obtained by reacting a polyfunctional (meth) acrylate having an isocyanate group and two or more photopolymerizable double bonds in one molecule. ..

[0010]

The outline of the present invention is as follows. First, a novolac type epoxy resin (a), an unsaturated monobasic acid (b) and a polybasic acid (c).
By the reaction with, a reaction product (I) having a photopolymerizability with an increased molecular weight is produced. Polyfunctional (meth) having an isocyanate group and two or more photopolymerizable double bonds in one molecule in the hydroxyl group present in this reaction product (I)
The acrylate (d) is reacted to obtain a reaction product (II) in which a large number of photopolymerizable double bonds are introduced.
Furthermore, in order to make this reaction product (II) water-soluble,
The acid anhydride (e) is reacted with the hydroxyl group in the reaction product (II) to introduce a carboxyl group. This reaction product is referred to as a reaction product (III).

Here, the order of the photopolymerizable double bond introduction reaction by the polyfunctional (meth) acrylate (d) and the carboxyl group introduction reaction by the acid anhydride (e) is that these reactions are all for hydroxyl groups. Therefore, the order does not necessarily have to be the above. The present invention will be described in detail below.

The novolac type epoxy resin (a) used in the present invention includes phenol novolac type epoxy resin, cresol novolac type epoxy resin, and the like.
These are obtained by reacting each novolak resin with epichlorohydrin by a conventional method. Generally, the following structural formula can be shown.

[0013]

[Chemical 3]

(However, n ≧ 2, R ¹ = H or C
H ₃ , R ² = H, CH ₃ , or halogen) n at this time
Is 2 or more, and more preferably 2 ≦ n <10.
In the novolac type epoxy resin (a), which is the raw material of the reaction product (I), it is difficult to obtain a value of n of 10 or more for manufacturing reasons, and thus n <10. When n is less than 2, unreacted substances are likely to remain when polymerized by the reaction with the polybasic acid (c), and the effect of increasing the molecular weight is not recognized. When it is done, the curability and the physical properties become poor.

The unsaturated monobasic acid (b) reacted with the novolac type epoxy resin (a) is a compound having a photopolymerizable unsaturated bond and a carboxyl group in the molecule,
Examples thereof include (meth) acrylic acid, crotonic acid, cinnamic acid, and the like, and (meth) acrylic acid is particularly preferably used.

The polybasic acid (c) has two or more carboxyl groups in one molecule, and among them, a dibasic acid that hardly causes gelation during multimerization can be preferably used. Examples include succinic acid, adipic acid, sebacic acid, azelaic acid, fumaric acid, isophthalic acid, and terephthalic acid, but from the viewpoint of imparting a better balance of hardness and toughness to the photocured product, a polybasic acid ( c),
It is particularly preferable to use a long-chain dibasic acid having a total of 18 or more carbon atoms other than those contained in the acid group.

As a concrete example of this long-chain dibasic acid, 1,
Dimer acid obtained from 18-octadecane dicarboxylic acid, 1,16- (6-ethylhexadecane) -dicarboxylic acid, 1,18- (7,12-octadecadiene) -dicarboxylic acid, linoleic acid, hydrogenated dimer acid Further, liquid polybutadiene containing carboxyl groups at both ends, liquid butadiene-acrylonitrile copolymer containing carboxyl groups at both ends, liquid polybutyl acrylate containing carboxyl groups at both ends, and the like can be mentioned.

The reaction of the novolac type epoxy resin (a) with the unsaturated monobasic acid (b) and the polybasic acid (c) is carried out by the reaction of the unsaturated monobasic acid (a) with one equivalent of the epoxy group in the novolac type epoxy resin (a). The sum of the carboxy groups in the basic acid (b) and the polybasic acid (c) is 0.9 to 1.1 chemical equivalents, and the amount of the polybasic acid (c) used is the novolac type epoxy resin (a) 1 The reaction is carried out at a ratio of 0.2 to 0.8 mol, more preferably 0.3 to 0.7 mol, based on mol.

In the ring-opening reaction and the multimerization reaction of the epoxy group with the unsaturated monobasic acid and polybasic acid, these are mixed in the above-mentioned ratios, and in the presence or absence of a solvent or a diluting monomer described below, It is carried out at 80 to 130 ° C in the coexistence of a polymerization inhibitor such as hydroquinone or oxygen and an esterification catalyst such as a tertiary amine or a chromium compound, and photopolymerization by a hydroxyl group due to ring opening of an epoxy group and an unsaturated monobasic acid. A reactive product (I) having a polymerizable double bond and having a high molecular weight by an ester bond via a polybasic acid is produced.

Reactant (I) has sufficient molecular weight and a double bond introduced by an unsaturated monobasic acid,
In order to further increase the photosensitivity, a polyfunctional (meth) acrylate (d) is used to introduce a photopolymerizable double bond. The polyfunctional (meth) acrylate (d) having an isocyanate group and a photopolymerizable double bond in one molecule used herein has, for example, two isocyanate groups having different reactivity in one molecule. It can be obtained by reacting diisocyanate (f) with a polyfunctional (meth) acrylate (g) having one hydroxyl group and two or more photopolymerizable double bonds in one molecule.

As diisocyanate (f), 2,4
-Toluene diisocyanate, isophorone diisocyanate, hydrogenated 2,4-toluene diisocyanate and the like can be mentioned. Examples of the polyfunctional (meth) acrylate (g) include glycerin di (meth) acrylate, tris (hydroxyethyl) isocyanurate di (meth) acrylate, trimethylpropane di (meth) acrylate,
Examples thereof include pentaerythritol tri (meth) acrylate and dipentaerythritol penta (meth) acrylate.

The reaction ratio of the two is such that the diisocyanate (f)
Polyfunctional (meth) acrylate (g) 0.
9 to 1.2 mol is suitable, both in the presence or absence of a solvent or a diluting monomer, in the coexistence of a polymerization inhibitor such as hydroquinone or oxygen and a urethanization catalyst such as a tertiary amine or a tin compound. A polyfunctional (meth) acrylate (d) having one isocyanate group and two or more photopolymerizable double bonds in one molecule can be obtained by reacting in a temperature range of room temperature to 130 ° C. ..

The reaction between the polyfunctional (meth) acrylate (d) and the reaction product (I) is carried out by reacting the isocyanate group in the polyfunctional (meth) acrylate (d) with the hydroxyl group present in the reaction product (I). By utilizing the urethane bond formed between the and, more photopolymerizable double bonds are introduced. The reaction ratio of the both is such that the polyfunctional (meth) acrylate (d) is 0.1 to 10.
0 mol is suitable, and the diisocyanate (f) can be reacted under the same conditions as the reaction of the polyfunctional (meth) acrylate (g), and by this reaction, the reaction product (II)
Is generated.

The reaction product (II) has a photopolymerizable double bond and a sufficient molecular weight to give a photocured product having appropriate flexibility. In order to impart water solubility as an added value, the acid anhydride (e) is reacted to produce a reaction product (III) having a carboxyl group introduced into the molecule.

As the acid anhydride (e), phthalic anhydride,
Dibasic acid anhydrides such as succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, 3,6-endomethylene-tetrahydrophthalic anhydride, tetrabromophthalic anhydride, trimellitic anhydride, etc. Tribasic acid anhydride, or biphenyl tetracarboxylic dianhydride, naphthalene tetracarboxylic dianhydride, diphenyl ether tetracarboxylic dianhydride, butane tetracarboxylic dianhydride, pyromellitic dianhydride,
Examples thereof include tetrabasic acid dianhydrides such as aliphatic or aromatic tetracarboxylic acid dianhydrides such as benzophenone tetracarboxylic acid dianhydride, and one or more of these can be used.

The amount of the acid anhydride (e) used is the amount of the reaction product (II)
0.1 to 0.9 per 1 chemical equivalent of hydroxyl group in
The chemical equivalent is suitable, and the reaction condition is 80 to 80% in the presence or absence of a solvent or a diluting monomer, in the presence of a polymerization inhibitor such as hydroquinone and oxygen, and optionally a ring-opening reaction catalyst such as a tertiary amine. The reaction can be performed under the condition of 130 ° C.

Since the acid anhydride (e) causes a ring-opening reaction by reacting with a hydroxyl group, one of the hydroxyl group existing in the reactant (II) and the ring-opening group of the acid anhydride is present. An ester bond is formed during the reaction, and at the same time, a reaction product (III) in which a carboxyl group is introduced into the molecule is produced. The carboxyl group-introducing reaction with the acid anhydride may be performed before introducing the photopolymerizable double bond with the polyfunctional (meth) acrylate.

The photopolymerizable resin thus obtained is
Since it has a carboxyl group, water solubility can be imparted by neutralizing part or all of the carboxyl group with an alkali and using it as a salt.

Examples of the alkali that can be used here include sodium carbonate, potassium carbonate, sodium hydroxide,
Alkali metal compounds such as potassium hydroxide; Alkaline earth metal compounds such as calcium hydroxide and calcium carbonate; Ammonia; Monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monopropylamine, dimethylpropylamine, monoethanol Amine, diethanolamine,
Examples include water-soluble organic amines such as triethanolamine, ethylenediamine, diethylenetriamine, dimethylaminoethyl methacrylate, and polyethyleneimine.
These 1 type (s) or 2 or more types can be used.

The amount of these alkalis used is preferably 0.2 to 1.1 chemical equivalents to 1 chemical equivalent of the carboxyl group in the photopolymerizable resin. Further, when it is used as a pattern or an image forming material, it becomes possible to easily dissolve and remove the photocurable resin composition in the unexposed portion with an aqueous solution of these alkalis.

The photopolymerizable resin according to the present invention has a molecular weight significantly larger than that of a conventional photopolymerizable resin having a novolak skeleton and a double bond capable of photopolymerization in one molecule. Since the amount is remarkably increased, it is possible to provide a photocurable resin composition having a high photosensitivity such that the resin is easily cured by a slight photopolymerization reaction. Further, since the probability of the three-dimensional reaction becomes higher, the heat resistance is excellent, and since the molecular weight is increased, the brittleness of the cured product is eliminated and the resin has appropriate flexibility.

The photocurable resin composition of the present invention can be obtained by adding a photopolymerization initiator to the above photopolymerizable resin.

Known photopolymerization initiators can be used, and specifically, benzoin, benzoin methyl ether, benzoin ethyl ether and other benzoins and their alkyl ethers; acetophenone, 2,2-dimethoxy-2-phenyl. Acetophenones such as acetophenone and 1,1-dichloroacetophenone; anthraquinones such as 2-methylanthraquinone, 2-amylanthraquinone, 2-t-butylanthraquinone and 1-chloroanthraquinone; 2,4-dimethylthioxanthone, 2,4
-Thioxanthones such as diisopropylthioxanthone and 2-chlorothioxanthone; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal;
Benzophenones such as benzophenone; 2-methyl-1
-[4- (methylthio) phenyl] -2-morpholinopropan-1-one or 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1;
Examples thereof include acylphosphine oxides and xanthones.

These photopolymerization initiators are used as one kind or as a mixture of two or more kinds, and are preferably contained in the photocurable resin composition in an amount of 0.5 to 15% by weight. When the amount of the photopolymerization initiator is less than 0.5% by weight, it is necessary to increase the light irradiation time or it is difficult to cause the polymerization even if the light irradiation is performed, so that an appropriate surface hardness can be obtained. Disappear. Further, the amount of the photopolymerization initiator is 15
When it exceeds the weight%, not only is there no merit,
It is not preferable because it is against the reduction of the amount of the initiator which is the object of the present invention.

In the photocurable resin composition according to the present invention, a diluting monomer or solvent may be added, if necessary, in addition to the above-mentioned photopolymerizable resin and photopolymerization initiator.

The diluting monomer or solvent is 5 to 60.
Addition of about wt% is preferable. Examples of the diluting monomer include diethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, β-hydroxyethyl (meth) acrylate, and (2-oxo-).
1,3-dioxolan-4-yl) -methyl (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane di (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate Acrylate etc. are mentioned.

As the solvent, hydrocarbons such as toluene and xylene; cellosolves such as cellosolve and butyl cellosolve; carbitols such as carbitol and butyl carbitol; esters such as cellosolve acetate and carbitol acetate; ketones such as methyl ethyl ketone. Kinds; ethers such as diethylene glycol dimethyl ether and the like,
These diluting monomers or solvents can be added alone or as a mixture.

In the photocurable resin composition according to the present invention,
Further, if necessary, a filler such as talc or clay, a coloring pigment, a defoaming agent, a coupling agent, a leveling agent, etc., an epoxy resin, an epoxy curing agent, etc. can be added.

The photocurable resin composition according to the present invention comprises an ink, a paint, a varnish, an adhesive, various resists, a printing plate,
It can be used as an image forming material.

[0040]

EXAMPLES The present invention will be specifically described below with reference to examples. Parts and% in the examples are based on weight.

Synthesis Example 1 To 444 parts of isophorone diisocyanate was added a reaction temperature of 5
While maintaining at 0 ° C., a mixture of 1192 parts of a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (1: 1 by weight ratio), 6.5 parts of dibutyltin dilaurate and 0.4 parts of benzoquinone was added dropwise over 1 hour. , Then at 50 ° C for 3 hours, then 100
After reacting for 2 hours at ℃, 2
A mixture (d-1) with pentaerythritol tetraacrylate containing 64% of polyfunctional (meth) acrylate having one or more photopolymerizable double bonds was obtained.

Example 1 Phenolic novolac type epoxy resin EPPN-201
(Nippon Kayaku, epoxy equivalent 187, n = 5) 340 parts, acrylic acid 109 parts, adipic acid 22 parts, toluene 80 parts, ethyl carbitol acetate 120 parts, triethylamine 1.7 parts and hydroquinone 0.3 parts. Was added, the mixture was reacted at 110 ° C. for 12 hours, and after confirming that the acid value was 3.4, the mixture was cooled to 50 ° C., and 298 parts of (d-1) obtained in Synthesis Example 1 was taken at 50 ° C. for 1 hour. Then, the mixture was reacted at 50 ° C. for 2 hours and further at 100 ° C. for 2 hours, and it was confirmed by infrared absorption spectrum that the isocyanate group had completely disappeared. Toluene and ethyl containing 68% of the reaction product (II) were used. Mixture with carbitol acetate and pentaerythritol tetraacrylate (II-1)
Got

Example 2 Phenolic novolac type epoxy resin EPPN-201
(Nippon Kayaku, epoxy equivalent 187, n = 5) 340 parts, acrylic acid 104 parts, 1,18-octadecanedicarboxylic acid SL-20 (Okamura Oil, acid value 332) 63
Parts, 217 parts butyl cellosolve acetate, 1.8 parts triethylamine and 0.3 parts hydroquinone,
After confirming that the acid value was 2.8 by reacting at 110 ° C. for 12 hours, it was cooled to 50 ° C. and obtained in Synthesis Example 1 (d−
1) 298 parts was added dropwise at 50 ° C. over 1 hour, and then 5
After reacting at 0 ° C. for 2 hours and further at 100 ° C. for 2 hours, it was confirmed by infrared absorption spectrum that the isocyanate group had completely disappeared, and butyl cellosolve acetate containing 68% of the reaction product (II) and pentaerythritol tetraacrylate were added. To obtain a mixture (II-2).

Example 3 To 400 parts of the mixture (II-2) obtained in Example 2, 63 parts of phthalic anhydride and 30 parts of butyl cellosolve acetate were added and reacted at 100 ° C. for 5 hours to give a reaction product having an acid value of 71. A mixture of butyl cellosolve acetate containing 68% (III) and pentaerythritol tetraacrylate (II
I-1) was obtained.

Example 4 Cresol novolac type epoxy resin EOCN-104
S (Nippon Kayaku, epoxy equivalent 220, n = 7 to 8) 3
In 22 parts, 94 parts of acrylic acid, 58 parts of dimer acid Versatime 228 (made by Henkel Hakusui, acid value 194), 104 parts of ethyl carbitol acetate, 104 parts of toluene,
Triphenylphosphine (2 parts) and methylhydroquinone (0.2 parts) were added, and the mixture was reacted at 110 ° C. for 14 hours. After confirming that the acid value of the reaction product reached 3.7, the mixture was cooled to 50 ° C. 186 parts of the obtained (d-1) was added at 50 ° C.
The mixture was added dropwise over 1 hour at 50 ° C. for 2 hours and then at 100 ° C. for 2 hours, and it was confirmed by infrared absorption spectrum that the isocyanate group had completely disappeared, and 68% of the reaction product (II) was contained. Ethyl carbitol acetate,
A mixture (II-3) with toluene and pentaerythritol tetraacrylate was obtained.

Example 5 To 400 parts of the mixture (II-3) obtained in Example 4, tetrahydrophthalic anhydride (78 parts) and ethylcarbitol acetate (37 parts) were added, and the mixture was reacted at 100 ° C. for 6 hours to give an acid value of 82. A mixture (III-2) containing ethyl carbitol acetate containing 68% of the reaction product (III), toluene, and pentaerythritol tetraacrylate was obtained.

Example 6 Cresol novolac type epoxy resin ECN1280
(Ciba Geigy, epoxy equivalent 227, n = 4.1)
Acrylic acid 75 parts to 319 parts, hydrogenated dimer acid Versadim 52 (manufactured by Hakusui Henkel, acid value 195) 104 parts, toluene 107 parts, ethyl carbitol acetate 107
Part, dimethylbenzylamine (1.8 parts) and hydroquinone (0.4 parts) were added, and the mixture was reacted at 110 ° C. for 12 hours. After confirming that the acid value of the reaction product reached 4.0, the mixture was cooled to 50 ° C. and synthesized. 50 parts of 230 parts of (d-1) obtained in Example 1
The mixture was added dropwise at 1 ° C over 1 hour, then reacted at 50 ° C for 2 hours and further at 100 ° C for 2 hours, and it was confirmed by infrared absorption spectrum that the isocyanate group had completely disappeared, and the reaction product (II) was 69%. A mixture (II-4) of toluene, ethyl carbitol and pentaerythritol tetraacrylate was obtained.

Example 7 To 400 parts of the mixture (II-4) obtained in Example 6, 41 parts of maleic anhydride and 19 parts of ethyl carbitol acetate were added and reacted at 100 ° C. for 5 hours to give a reaction product having an acid value of 75. A mixture (III-3) of toluene, ethylcarbitol acetate and pentaerythritol tetraacrylate containing 68% of (III) was obtained.

Comparative Example 1 72 parts of acrylic acid, 86 parts of toluene, 1.1 parts of dimethylbenzylamine and 0.2 parts of methylhydroquinone were added to 227 parts of the cresol novolac type epoxy resin used in Example 6 and the mixture was heated at 110 ° C. for 12 hours. Reacted for hours. The acid value was 3.5. 42 parts of pentaerythritol tetraacrylate was further added to the reaction product to prepare a comparative reaction product (I).
To obtain a mixture (E-1) containing 70% of toluene and pentaerythritol tetraacrylate.

Comparative Example 2 To 454 parts of the cresol novolac type epoxy resin used in Example 6, 144 parts of acrylic acid, 128 parts of ethyl carbitol acetate, 128 parts of toluene, 2.0 parts of dimethylbenzylamine and 0.4 part of hydroquinone were added. In addition, the reaction was carried out at 110 ° C. for 12 hours, and the acid value of the reaction product was 3.
After confirming that it was 8, the mixture was cooled to 50 ° C., 164 parts of (d-1) obtained in the synthesis example was added dropwise at 50 ° C. over 1 hour, then 50 ° C. for 2 hours, and further 100 ° C. for 2 hours. After reacting for a period of time, it was confirmed by infrared absorption spectrum that the isocyanate group had completely disappeared.
% Of toluene, ethyl carbitol acetate and pentaerythritol tetraacrylate (E
-2) was obtained.

Comparative Example 3 To 400 parts of the mixture (E-2) obtained in Comparative Example 2 was added 72 parts of tetrahydrophthalic anhydride and 31 parts of ethylcarbitol acetate, and the mixture was reacted at 100 ° C. for 6 hours to give an acid value of 77. Toluene containing 68% of the comparative reactant (III),
A comparative mixture (E-3) with ethyl carbitol acetate and pentaerythritol tetraacrylate was obtained.

Comparative Example 4 454 parts of the cresol novolac type epoxy resin used in Example 6 was added with 113 parts of acrylic acid, 31 parts of adipic acid, 85 parts of toluene, 85 parts of ethyl carbitol acetate,
Dimethylbenzylamine 2 parts and hydroquinone 0.
After adding 4 parts and reacting at 110 ° C. for 12 hours to confirm that the acid value was 3.7, 85 parts of pentaerythritol tetraacrylate was added and toluene and ethylcarbitol containing 70% of the comparative reaction product (IV). A comparative mixture (E-4) of acetate and pentaerythritol tetraacrylate was obtained.

Comparative Example 5 To 400 parts of the comparative mixture (E-4) obtained in Comparative Example 4, 85 parts of tetrahydrophthalic anhydride and 36 parts of ethyl carbitol acetate were added, and the mixture was reacted at 100 ° C. for 6 hours,
A comparative mixture (E-5) of toluene, ethyl carbitol acetate, and pentaerythritol tetraacrylate containing 70% of the comparative reaction product (V) having an acid value of 86 was obtained. Table 1 collectively shows the blending ratio of each mixture.

[0054]

[Table 1]

Evaluation Method To 100 parts of each photopolymerizable resin obtained in Examples 1 to 7 and Comparative Examples 1 to 5, 3 parts of 2,2-dimethoxy-2-phenylacetophenone was added as a photopolymerization initiator, Coating on a glass plate to a thickness of 50 μm (approx. 50 mm x 50 mm)
Then, preliminary drying was performed at 80 ° C. for 30 minutes in a circulating air oven. After cooling to room temperature, UV irradiation was performed for a predetermined period of time with an irradiation distance of 300 mm using a metal halide lamp MO3-L21 (lamp output 80 w / cm) manufactured by Eye Graphics Co., Ltd. The state and the glass transition point were examined.

Curing degree: According to a pencil hardness meter. (JISK5
According to 400. ) State of crack: Visual observation Glass transition point: The cured film was peeled from the glass plate, and measurement was performed using a viscoelasticity analyzer RSAII manufactured by Rheometrics Co., Ltd. in a compression mode at a frequency of 1 Hz. The results are summarized in Table 2.

[0057]

[Table 2]

[0058]

EFFECTS OF THE INVENTION The photocurable resin composition according to the present invention has a slight photopolymerization reaction due to the polymer molecular design of increasing the molecular weight and the amount of double bonds, as compared with the conventional photopolymerizing resin having a novolak skeleton. Since the resin can be easily cured with 3D and the probability of three-dimensionalization becomes higher, it has excellent surface hardness and heat resistance even with a small amount of photoinitiator or a small amount of light irradiation or irradiation time. Further, it is possible to provide a photo-cured product having appropriate flexibility. In addition, since the carboxyl group is introduced into the resin, water solubility can be imparted, and a wide range of applications can be developed.

Continuation of front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location G03F 7/038 503

Claims (3)

[Claims] 1. The formula: (However, n ≧ 2, R ¹ = H or CH ₃ , R ² = H,
CH ₃ or a halogen) novolac type epoxy resin is reacted with unsaturated monobasic acid and polybasic acid,
A photopolymerizable resin obtained by reacting a reaction product polymerized through an ester bond with a polyfunctional (meth) acrylate having an isocyanate group and two or more photopolymerizable double bonds in one molecule, and A photocurable resin composition comprising a photopolymerization initiator. 2. A polyfunctional (meth) acrylate having an isocyanate group and two or more photopolymerizable double bonds in one molecule is reacted with the polymerized reaction product according to claim 1 and an acid anhydride. A photocurable resin composition containing a photopolymerizable resin and a photopolymerization initiator obtained by the above. 3. The photocurable resin according to claim 1, wherein the polybasic acid according to claim 1 is a long-chain dibasic acid having a total of 18 or more carbon atoms other than those contained in the acid group. Composition.