JPH07261387A - Photosensitive resin composition - Google Patents

Abstract

PURPOSE:To obtain a photosensitive resin compsn. capable of dilution with water and capable of forming a cured coating film excellent in hardness, chemical and water resistances. CONSTITUTION:This photosensitive resin compsn. contains a photopolymn. initiator and a reactional product obtd. by allowing epoxy resin having two or more epoxy groups and one or more hydroxyl groups in one molecule to react with 0.1-0.9mol dibasic acid anhydride to 1mol of the epoxy resin and 0.5-1.0mol acrylic acid and/or methacrylic acid to 1mol epoxy group in the epoxy resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-dilutable photosensitive resin composition, which is a coating of paper, glass, metal, etc., which has excellent curability, adhesion, chemical resistance, hardness and the like. The present invention relates to a photosensitive resin composition suitable for agents and the like.

[0002]

2. Description of the Related Art In recent years, an ultraviolet curing method has been extensively studied and put into practical use as a resin curing method. The main component of the UV curable resin is a reactive oligomer (prepolymer), which generally has a high viscosity and requires some diluent for handling. As such a diluent, various photosensitive monomers corresponding to the required physical properties are used, but if the monomer is used excessively to obtain an appropriate viscosity, the excellent physical properties peculiar to the oligomer are lost. I will end up. Therefore, some organic solvents may be used together. However, the use of such organic solvents improves the working environment, avoids the risk of fire,
It is not preferable from the viewpoint of environmental protection and effective use of resources. In particular, legal regulations are being tightened on the use of organic solvents due to environmental pollution, effects on the human body, etc., and there is a worldwide trend toward solvent-free paints and the like. Under such circumstances, it is strongly desired to use water as a diluent for the UV curable resin.

When water is used as a diluent, it is necessary to impart hydrophilicity or water solubility to the reactive oligomer or monomer, and such studies have been made. For example, in JP-A-3-170932, a polyether bond, in JP-A-2-298501, an amide bond, and in JP-A-4-211413 and JP-A-5-14.
In 0251, a carboxylate is disclosed in JP-A-5-114.
In Japanese Patent Laid-Open No. 42-21141, a sulfonate is disclosed.
In Japanese Patent Laid-Open No. 3, an onium salt is added to a photosensitive resin as a group that imparts hydrophilicity or water solubility, respectively. In addition, a carboxyl group, a sulfonic acid group, an amino group, an amine salt and the like have been investigated as a chemical structure for imparting hydrophilicity or water solubility to a reactive oligomer or monomer.

[0004]

However, in order to impart water dilutability by means of a polyether bond, a polyether bond having a considerably long chain length is required, and the crosslink density is lowered to impair film strength and water resistance. The problem arises that Further, an amino group or an amide group causes a problem that acid resistance decreases, and a carboxyl group or a sulfonic acid group causes a problem that alkali resistance decreases. Further, salts such as amine salts, onium salts, carboxylates, and sulfonates are ionic, and thus cause a problem that water resistance is lowered. Therefore, none of the conventional photosensitive resin compositions can be diluted with water and are satisfactory in curability, adhesion, chemical resistance, water resistance, hardness and the like.

The object of the present invention is to solve the above-mentioned conventional problems, to contain no or a small amount of an organic solvent, to dilute with water, and to have curability, adhesion,
It is intended to provide a photosensitive resin composition having excellent chemical resistance, water resistance, hardness and the like.

[0006]

The photosensitive resin composition of the present invention comprises a dibasic acid based on 1 mol of an epoxy resin (a) having two or more epoxy groups and one or more hydroxyl groups in the molecule. 0.1 to 0.9 mol of the anhydride (b) and 0.5 to 1.0 mol of acrylic acid and / or methacrylic acid (c) corresponding to 1 mol of the epoxy group in the epoxy resin. It is characterized by containing a reaction product (A) obtained by reacting with and a photopolymerization initiator (B).

Epoxy resin (a) used in the present invention
Is not particularly limited as long as it has two or more epoxy groups and one or more hydroxyl groups in the molecule, but the reaction product (A When carrying out the reaction (1), it is preferably a liquid at room temperature or a solid with a low melting point. As such, for example, glycerin diglycidyl ether, trimethylolpropane diglycidyl ether, pentaerythritol di or triglycidyl ether,
Examples thereof include sorbitol tri- or tetra- or pentaglycidyl ether, polyglycerin polyglycidyl ether, sorbitan polyglycidyl ether and glycidyl ester type epoxy resins thereof.

Dibasic acid anhydride (b) used in the present invention
In order to smoothly carry out the above reaction without using an organic solvent or with a very small amount of solvent, it is preferably a liquid at room temperature or a solid having a relatively low melting point. As such, for example, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, methylbutenyltetrahydrophthalic anhydride, succinic anhydride, dodecenyl. Examples thereof include succinic anhydride, maleic anhydride, and itaconic anhydride.

The ratio of the epoxy resin (a) and the dibasic acid anhydride (b) in the production of the reaction product (A) is such that the dibasic acid anhydride (b) is mixed with 1 mol of the epoxy resin (a). ) 0.
1 to 0.9 mol, preferably 0.30 to 0.86
It is a mole. If the proportion of the dibasic acid anhydride (b) is too low, the physical properties expected in the present invention will not be obtained, and if the proportion of the dibasic acid anhydride (b) is too high, the polymer will be polymerized during the reaction and will be handled later. Will be difficult.

In the present invention, the proportion of acrylic acid and / or methacrylic acid (c) (hereinafter referred to as "(meth) acrylic acid (c)") is equivalent to 1 mol of the epoxy group in the epoxy resin (a). With respect to 0.5 to 1.0 mol. The approximate optimum blending amount of (meth) acrylic acid (c) can be calculated by the following formula.

[Mole number of (meth) acrylic acid (c)] =
[Mole number of epoxy resin (a) x epoxy resin (a) 1
Number of epoxy groups in molecule]-[Number of moles of dibasic acid anhydride (b)]

Therefore, it is expressed as follows for 1 mol of the epoxy resin (a). [Mole number of (meth) acrylic acid (c)] = [Number of epoxy groups in one molecule of epoxy resin (a)]-[Mole number of dibasic acid anhydride (b)]

The reaction for obtaining the reaction product (A) is preferably carried out by adding a reaction catalyst and a polymerization inhibitor at 60 to
It is carried out under the condition of 120 ° C. If the reaction temperature is too high, gelation may occur during the reaction, and if the reaction temperature is too low, the reaction takes a long time, which is not realistic.

Examples of the reaction catalyst include triethylamine, tributylamine, 4-dimethylaminopyridine, dimethylaniline, benzyldimethylamine, triphenylstibine, triethylbenzylammonium chloride, tetramethylammonium chloride, tetrabutylammonium bromide and 2-ethyl. -4-Methylimidazole, 1-benzyl-2-methylimidazole, dimethylamine hydrochloride, triethylamine hydrochloride and the like can be mentioned. The amount of the catalyst added is preferably within the range of 0.1 to 10% by weight based on the total amount charged.

Examples of the polymerization inhibitor include hydroquinone, methoxyhydroquinone, phenothiazine and t-.
Butylcatechol, di-t-butyl-p-cresol,
Examples thereof include p-benzoquinone and naphthoquinone. The amount of the polymerization inhibitor added is 0.01 with respect to the total amount charged.
It is preferably within the range of 1% by weight.

Photopolymerization initiator (B) used in the present invention
Are not particularly limited, but include, for example, benzyl dimethyl ketal, benzoin isopropyl ether, 2,4-dimethylthioxanthone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl- [4-
(Methylthio) phenyl] -2-morpholino-1-propanone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzophenone, 4,4′-bisdimethylaminobenzophenone and the like can be mentioned.

The photosensitive resin composition of the present invention may contain a diluent. As such a diluent,
A water-soluble or water-dilutable solvent or water can be used. Here, "water-soluble" means the property of being dissolved in water at an arbitrary ratio, and "water-dilutable" is soluble in water within a certain range, but becomes insoluble and separates out of the range, or is not dissolved. Means the property of being uniformly dispersed in a state of being emulsified or close thereto by adding water.

Such a diluent may be added before or during the reaction for producing the reaction composition (A) or after the reaction. As the diluent to be added before or during the reaction, those having no hydroxyl group are preferable, and examples thereof include ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, tetrahydrofuran, dioxane, acetonitrile, dimethylformamide, ethylene glycol monomethyl ether acetate, morpholine and the like.

When diluted after the reaction, it may contain a hydroxyl group. For example, methanol, ethanol, isopropanol, t-butanol, ethylene glycol monomethyl ether, ethylene glycol may be used in addition to the diluent used before or during the reaction. Monoethyl ether,
Alcohols such as propylene glycol monomethyl ether and ethyl lactate can also be used.

The photosensitive resin composition of the present invention may contain a water-soluble or water-dilutable photopolymerizable monomer as the reactive diluent. Such a photopolymerizable monomer may be added before or during the reaction or after the reaction.

Examples of the photopolymerizable monomer to be added before or during the reaction include methoxydi- or tri- or tetraethylene glycol acrylate or methacrylates thereof, methoxypolyethylene glycol acrylate or methacrylate, ethoxydiethylene glycol acrylate or methacrylate, 2- Ethoxyethyl acrylate or methacrylate, polyethylene glycol # 200 or # 400 or # 60
0 diacrylate or dimethacrylate thereof, polyethoxytrimethylolpropane triacrylate or trimethacrylate, polyethoxypentaerythritol tetraacrylate or tetramethacrylate, polyethoxylated bisphenol A diacrylate or dimethacrylate, morpholine acrylate or methacrylate, N-vinylpyrrolidone, Examples thereof include acrylamide, methacrylamide, dimethylacrylamide, dimethylmethacrylamide, dimethylaminoethyl acrylate or methacrylate, diethylaminoethyl acrylate or methacrylate.

As the photopolymerizable monomer added after the reaction, in addition to the above-mentioned monomers, 2-hydroxyethyl acrylate or methacrylate, 2-hydroxypropyl acrylate or methacrylate, polyethylene glycol diglycidyl ether diacrylate or diester. Methacrylate, tripropylene glycol diglycidyl ether diacrylate or dimethacrylate, glycerin diglycidyl ether diacrylate or dimethacrylate, etc. can also be used.

Since the physical properties of the cured film may be deteriorated if a large amount of these photopolymerizable monomers is used, it is preferably 50% by weight or less in the composition.

[0024]

Action and effect of the invention An example of the reaction for producing the reaction product (A) in the photosensitive resin composition of the present invention is shown schematically below.

[0025]

[Chemical 1]

As shown in the above reaction formula, the acid anhydride ring of the dibasic acid anhydride (b) is opened by reacting the hydroxyl group in the epoxy resin (a) with the dibasic acid anhydride (b). The acid generated by ring-opening and ring-opening reacts with the epoxy group of the epoxy resin (a). Further, (meth) acrylic acid (c) reacts with the epoxy resin (a), and a polymerizable double bond is introduced. When the epoxy resin (a) and the (meth) acrylic acid (c) are reacted without using the dibasic acid anhydride (b), the molecular weight of the reaction product is about several hundreds. In the present invention, by using the dibasic acid anhydride (b), the molecular weight of the reaction product is increased to several thousand to 10,000 or more, and therefore sufficient adhesion to the substrate can be obtained. Although the viscosity increases due to the increase in the molecular weight, the reaction product (A) in the present invention has a sufficiently large amount of hydroxyl groups, and therefore can be diluted with water and does not hinder the coating operation and the like.

Further, the reaction product (A) in the present invention
Has a sufficiently high (meth) acryloyl group concentration, so that the curability is good and the crosslink density is high. Therefore, it is possible to obtain a tough cured film having a high hardness and excellent chemical resistance and water resistance.

By using the epoxy resin (a) that is liquid or has a low melting point at room temperature, the reaction product (A) is synthesized without using an organic solvent or with a small amount. be able to. Further, since the reaction product (A) has a high molecular weight due to the addition of the dibasic acid anhydride (b) as described above, the reaction amount can be adjusted by adjusting the addition amount of the dibasic acid anhydride (b). The molecular weight of the product (A) can be adjusted. Therefore, the quality design of the photosensitive resin composition of the present invention can be widened.

[0029]

The present invention will be described in detail below with reference to specific examples, but the present invention is not limited to these examples.

Synthesis Example 1 Polyglycerin polyglycidyl ether (manufactured by Nagase Kasei Co., Ltd., trade name “Denacol EX-512”, epoxy equivalent 169, viscosity 1500 mPa · s / 25 ° C.) 676 g
(1 mol), 80 g (0.8 mol) of succinic anhydride, 9.8 g of triethylamine, and 0.5 g of hydroquinone were charged into a 1-liter four-necked flask equipped with a stirrer, a thermometer, and a cooling tube, and the temperature was 70 to 75 ° C. After reacting for 2 hours at
230 g of acrylic acid (3.2 mol, 0.8 mol with respect to 1 mol of epoxy groups in the epoxy resin) was added, and the mixture was further reacted at 90 to 100 ° C. for 12 hours to give a viscosity of 1
600,000 mPa · s / 25 ° C, acid value 1.8 mgKOH /
g, weight average molecular weight (GPC measurement) 7660 was obtained.

Synthesis Example 2 Sorbitan polyglycidyl ether (manufactured by Nagase Kasei Co.,
Product name "Denacol EX-651A", epoxy equivalent 1
75, viscosity 1400 mPa · s / 25 ° C.) 525 g (1
Mol), methylhexahydrophthalic anhydride (manufactured by Shin-Nippon Rika Co., Ltd., trade name "Rikacid MH-700") 101 g
(0.6 mol), 173 g of acrylic acid (2.4 mol, 0.8 mol based on 1 mol of the epoxy group in the epoxy resin), 8 g of triethylamine, 0.4 g of hydroquinone.
Was reacted in the same manner as in Synthesis Example 1 described above to give a viscosity of 530,000 m.
A product having a Pa · s / 25 ° C., an acid value of 1.9 mgKOH / g and a weight average molecular weight (GPC measurement) of 3150 was obtained.

Comparative Synthetic Example 1 The same epoxy resin as in Synthetic Example 1 676 g (1 mol), acrylic acid 288 g (4 mol, 1 mol per 1 mol of epoxy group in the epoxy resin), triethylamine 9.6 g, Hydroquinone 0.49 g was reacted in the same manner as in Synthesis Example 1 above, and the viscosity was 100,000 mPa · s / 25.
℃, acid value 1.5mgKOH / g, weight average molecular weight (GP
C measurement) 1230 product was obtained.

Comparative Synthesis Example 2 Tetraethylene glycol diglycidyl ether (manufactured by Nagase Kasei Co., Ltd., trade name “Denacol EX-821”, epoxy equivalent 195, viscosity 66 mPa · s / 25 ° C.) 682
g (1.75 mol), 252 g of acrylic acid (3.5 mol, 1 per 1 mol of epoxy group in the epoxy resin)
Mol), 9.3 g of triethylamine and 0.47 g of hydroquinone were reacted in the same manner as in Synthesis Example 1 above, and the viscosity was 5400 mPa · s / 25 ° C. and the acid value was 1.3 mgKOH /
g, weight average molecular weight (GPC measurement) 680 product was obtained.

[0034] For product 100g was obtained in Example 1 Synthesis Example 1, a photopolymerization initiator (Ciba-Geigy Japan Ltd., trade name "Irgacure 5
00 ") and 4 g of water and 30 g of water are mixed together. Film thickness of about 10μm, about 10μm, about 6μm on glass plate, electrogalvanized steel plate and kraft paper with 10 bar coater
And dried at 70 ° C. for 10 minutes,
It was irradiated with ultraviolet rays and cured. The water dilutability (dilution viscosity value) of the resin composition, the ultraviolet curability of the coating film of the photosensitive resin composition, the adhesion of the cured film, the water resistance, the alkali resistance and the acid resistance were evaluated as follows. In addition, except for the adhesiveness, all the materials cured on a glass plate were evaluated.

Water Dilutability and Diluted Viscosity Value Water was gradually added to 100 g of the reaction product, and the amount of water when it became cloudy was divided by 100 and evaluated. Further, the viscosity when diluted with water was measured.

UV curable UV irradiator (manufactured by USHIO INC., Trade name "UVC-50"
34 type)) was used to irradiate a light amount of 10 mJ / cm ² · 1 pass, the degree of curing was examined by touching with a finger, and the total amount of light when completely cured was evaluated. Moreover, the pencil hardness of the cured film was measured based on JIS-K5400-6.14.

Adhesion A cross cut of 2 mm × 2 mm was performed, and a peeling test was performed using cellophane tape. The criteria for judgment were as follows. ◎… No peeling at all ○… Peeling off only a part △… Peeling off most ×… Peeling off the entire surface

Water resistance After immersing the sample in ion-exchanged water at 20 to 25 ° C. for 6 hours, it was evaluated according to the following criteria. ◎… No change ○… Partial whitening △… Full whitening ×… Swelling

Alkali resistance and acid resistance A sample is a 5% caustic soda aqueous solution (alkali resistance) or 5
% Hydrochloric acid (acid resistant) at 20-25 ° C for 6 hours,
The same criteria as in the above water resistance test were evaluated.

Example 2 30 g of polyethylene glycol # 600 diacrylate, 4 g of a photopolymerization initiator (Irgacure 500), and 20 g of water were added to 70 g of the product of Synthesis Example 1 and mixed, and the same as in Example 1. Then, the resin composition and the cured film were evaluated.

Example 3 4 g of a photopolymerization initiator (Irgacure 500) and 25 g of water were added to 100 g of the product of Synthesis Example 2 and mixed, and a resin composition and a cured film were prepared in the same manner as in Example 1. Was evaluated.

Comparative Example 1 4 g of a photopolymerization initiator (Irgacure 500) and 15 g of water were added to 100 g of the product of Comparative Synthesis Example 1 and mixed, and a resin composition and curing were carried out in the same manner as in Example 1 above. The film was evaluated.

Comparative Example 2 4 g of a photopolymerization initiator (Irgacure 500) and 10 g of water were added to and mixed with 100 g of the product of Comparative Synthesis Example 2 described above, and a resin composition and curing were carried out in the same manner as in Example 1 above. The film was evaluated.

The evaluation results of Examples 1 to 3 and Comparative Examples 1 and 2 are shown below.

[0045]

[Table 1]

As is clear from Table 1, the molecular weights of the reaction products (A) in Examples 1 to 3 according to the present invention are higher than those in Comparative Examples 1 and 2, and the adhesion to kraft paper, glass plate and steel plate is high. Excellent in hardness and high film hardness. Further, Examples 1 to 3 have sufficient ultraviolet curability as compared with Comparative Examples 1 and 2. Furthermore, also in water resistance, alkali resistance and acid resistance, Comparative Examples 1 and 2
It turns out that it is superior to.

As is clear from Table 1, Example 1
The photosensitive resin compositions of to 3 have sufficient water dilutability, and water can be used as a diluent.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical display location G03F 7/031 7/038 (72) Inventor Minoru Kasaki 687 Arimoto, Wakayama, Wakayama Shin Nakamura Gaku Kogyo Co., Ltd.

Claims (4)

[Claims] 1. A) (b) dibasic acid anhydride 0.1 to 0..0 per mole of an epoxy resin having (A) (a) two or more epoxy groups and one or more hydroxyl groups in the molecule. 9 moles,
(C) a reaction product obtained by reacting an amount of acrylic acid and / or methacrylic acid corresponding to 0.5 to 1.0 mol with respect to 1 mol of epoxy groups in the epoxy resin; ) A photosensitive resin composition comprising a photopolymerization initiator. 2. The photosensitive resin composition according to claim 1, which contains a water-soluble or water-dilutable solvent and / or water as a diluent. 3. The photosensitive resin composition according to claim 1, which contains one or more water-soluble or water-dilutable photopolymerizable monomers as the reactive diluent. 4. The blending amount of the acrylic acid and / or methacrylic acid is [the number of moles of acrylic acid and / or methacrylic acid] =
The photosensitive resin composition according to claim 1, which has a compounding amount represented by [the number of epoxy groups in one molecule of epoxy resin]-[the number of moles of dibasic acid anhydride].