JP3293905B2 - Radiation-curable resin composition and cured product thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a radiation-curable resin composition. More specifically, the present invention relates to a radiation-curable resin composition containing a specific urethane (meth) acrylate having a carboxyl group in a molecule as a component.

[0002]

2. Description of the Related Art Radiation-curable resin compositions which can be cured by ultraviolet rays or electron beams have been widely used in inks, paints, adhesives, and other applications from pollution-free and energy-saving purposes. Organic solvents are used to clean printers and coating machines after use of these inks and paints, but with the recent rise in environmental issues, the demand for changing the cleaning solution to aqueous solvents has increased. ing. Nevertheless, in reality, satisfactory water-soluble, radiation-curable resin compositions have not yet been obtained.

[0003]

SUMMARY OF THE INVENTION Development with a resin composition which solves the problems in the prior art as described above, that is, a dilute aqueous alkali solution (for example, an aqueous solution of caustic soda, potassium hydroxide, sodium carbonate, ammonia, amines, etc.) can be carried out. It is possible to provide a radiation-curable resin composition in which the uncured portion is easily dissolved in water and easily removed, and the cured portion is excellent in water resistance, solvent resistance, chemical resistance and the like.

[0004]

The inventor of the present invention has conducted intensive studies on the problems to be solved by the invention as described above, and as a result, has found that a specific compound having a carboxyl group and a (meth) acryloyl group in the molecule is used. As a result, the present invention finds a resin composition which is compatible, has excellent storage stability, can be dissolved and removed with a dilute alkaline aqueous solution, and has a cured product excellent in water resistance, solvent resistance, chemical resistance, etc. Was completed. That is, the present invention relates to a compound (a) represented by the formula (1):

[0005]

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(Where a and b are each a number from 0 to 10,
The average value of a + b is 0.5 to 20. ), An organic polyisocyanate (b) and a hydroxyl group-containing (meth) acrylate (c), a urethane (meth) acrylate (A), a reactive diluent (B), and a photopolymerization initiator (C) as an optional component. The present invention relates to a radiation-curable resin composition characterized by containing:

In the present invention, urethane (meth) acrylate (A) which is a reaction product of compound (a) represented by formula (1), organic polyisocyanate (b) and hydroxyl group-containing (meth) acrylate (c) is used. I do. The compound (a) in which the urethane (meth) acrylate (A) is represented by the formula (1) can be obtained by reacting dimethylolpropionic acid with ε-caprolactone. The reaction is carried out at ε per equivalent of hydroxyl group of dimethylolpropionic acid.
Reacting 0.25 to 10 moles of caprolactone.
In order to accelerate the reaction, it is preferable to use stannous chloride, tetrapropyl titanate or the like as a catalyst. The amount of the catalyst used is 50 to 5000 based on the reaction mixture.
ppm is preferred. The reaction temperature is preferably from 70 to 200 ° C, particularly preferably from 80 to 150 ° C. Reaction time is 1
-20 hours are preferred.

Specific examples of the organic polyisocyanate (b) include, for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylylene diisocyanate, diphenylmethane-4,4'-diisocyanate, dicyclohexylmethane-isocyanate. Examples thereof include diisocyanate, isophorone diinsocyanate, and hexamethylene diisocyanate. Further, specific examples of the hydroxyl group-containing (meth) acrylate (c) include, for example, 2-hydroxyethyl (meth) acrylate, 2
-Hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, pentaerythritol tri (meth) acrylate, glycerin di (meth) acrylate, tris (2-hydroxyethyl) isocyanurate- Examples thereof include di (meth) acrylate and N-methylol (meth) acrylamide.

The reaction between the compound (a) represented by the formula (1) and the organic polyisocyanate (b) is carried out with respect to one equivalent of the hydroxyl group of the compound (a) represented by the formula (1). It is preferable to use 1.1 to 2.0 equivalents of the isocyanate group of the organic polyisocyanate (b). The reaction temperature is preferably from 60 to 100 ° C, particularly preferably 75 to 100 ° C.
８５85 ° C. The reaction time is preferably 5 to 20 hours.
Subsequently, the hydroxyl group of the hydroxyl group-containing (meth) acrylate (c) is preferably based on 1 equivalent of the isocyanate group of the reaction product of the compound (a) represented by the formula (1) and the organic polyisocyanate (b), preferably Can react with 0.95 to 1.2 equivalents to obtain urethane (meth) acrylate (A). In order to prevent this polymerization, it is preferable to use a polymerization inhibitor, for example, methylhydroquinone, p-methoxyphenol, hydroquinone, or the like. The amount of the polymerization inhibitor to be used is 0.1 to the reaction mixture.
It is preferably from 0.01 to 0.5% by weight. Reaction temperature is 60-10
0 ° C is preferable, and particularly preferably 75 to 85 ° C.
The reaction time is preferably 5 to 20 hours.

Next, the reactive diluent (B) used in the present invention.
Specific examples of the compound are widely used from monofunctional ones to polyfunctional ones. Among them, particularly preferred ones are 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate ,
N-vinylpyrrolidone, acryloyl morpholine, carbitol (meth) acrylate, polyethylene glycol di (meth) acrylate, glycerin di (meth) acrylate, glycerin mono (meth) acrylate, pentaerythritol tri (meth) acrylate, tris (2-hydroxy Ethyl) isocyanurate di (meth)
Water-soluble substances such as acrylates can be used.

Specific examples of the photopolymerization initiator (C) that can be used as an optional component include 1-hydroxycyclohexylphenyl ketone, benzophenone, 2-methyl-
1 [4- (methylthio) phenyl] -2-morpholino-
Propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -1-butanone,
2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, acetophenone dimethyl ketal, 4,4'-bisdiethylaminobenzophenone,
-(2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl ketone) and the like.
These can be used alone or in combination of two or more. Such a photopolymerization initiator may be used alone or in combination of known photopolymerization accelerators such as ethyl N, N-dimethylaminobenzoate, isoamyl N, N-dimethylaminobenzoate, triethanolamine and triethylamine. Can be used in combination.

The radiation-curable resin composition of the present invention can be obtained by preparing components (A) to (C) by mixing, dissolving, dispersing, kneading and the like.

The proportion of each component used in the present invention is preferably 29 to 95% by weight, more preferably 39 to 95% by weight for the component (A).
The content of the component (B) is preferably from 5 to 70% by weight, particularly preferably from 20 to 60% by weight.
The components are preferably 0 to 15% by weight, particularly preferably 0 to 15% by weight.
10% by weight.

The radiation-curable resin composition of the present invention may further contain, if necessary, a range which does not deviate from the object of the present invention, in particular, the solubility of a dilute alkali aqueous solution, storage stability, and water resistance and solvent resistance of the cured product. Known and common organic solvents, inorganic fillers, additives, and the like can be added as long as chemical resistance and the like can be maintained.

The radiation referred to in the present invention is an electron beam, α ray,
It is a general term for ionizing radiation, light and the like, such as β-rays, γ-rays, X-rays, neutron rays or ultraviolet rays. The radiation-curable resin composition of the present invention can be usually cured by radiating the above-mentioned radiation as it is. The resin composition of the present invention can be used, for example, for paints, adhesives, printing inks, printing materials, coatings, photoresists, and the like.

[0016]

Next, the present invention will be further described with reference to examples. In the following, all parts are by weight unless otherwise specified. Synthesis example of urethane (meth) acrylate Synthesis example 1 110 parts of dimethylolpropionic acid, 366 parts of ε-caprolactone, and 0.15 part of stannous chloride were charged.
C. and reacted for about 10 hours. Since unreacted .epsilon.-caprolactone became 1% by weight or less, the mixture was cooled to 60.degree. C., and 333.4 parts of isophorone diisocyanate and polyethylene glycol diacrylate (a diluent) were used. KAYARAD PEG400 manufactured by Nippon Kayaku Co., Ltd.
DA) 409.4 parts and react at 80 ° C. for about 10 hours.
8 parts and 0.6 part of p-methoxyphenol were charged, and
C. for about 15 hours, and urethane acrylate containing 30% by weight of polyethylene glycol diacrylate (A-
1) was obtained.

Synthesis Example 2 134 parts of dimethylolpropionic acid, 666 parts of ε-caprolactone and 0.24 part of stannous chloride were charged, and
℃, react for about 10 hours, cool down to 60 ℃,
Then, 261 parts of tolylene diisocyanate were charged, and 8
The mixture was reacted at 0 ° C. for about 10 hours, and then 121.8 parts of 2-hydroxyethyl acrylate and 0.6 part of p-methoxyphenol were charged and reacted at 80 ° C. for about 15 hours to obtain a urethane acrylate (A-2).

Examples 1 to 4 The components were dissolved and mixed in accordance with the composition shown in Table 1 (the numerical values indicate parts by weight) to obtain the radiation-curable resin composition of the present invention.
Using a radiation bar this radiation-curable resin composition,
Each was applied to tin-free steel so as to have a thickness of 20 μm, and was irradiated with ultraviolet rays from a high-pressure mercury lamp and cured to obtain a test piece. Using this test piece, as described below, water resistance, solvent resistance, alkali resistance and dilute alkali of the composition,
A solubility test in an aqueous solution was performed.

[0019]

Table 1 Example 1 * 6 1 2 3 4 Urethane acrylate (A-1) obtained in Synthesis Example 1 70 30 Urethane acrylate (A-2) obtained in Synthesis Example 2 40 60 30 2-hydroxyethyl acrylate 20 10 10 Acryloylmorpholine 30 30 30 Polyethylene glycol diacrylate 10 30 Irgacure 184 * 1 55-5 Solubility in dilute alkaline aqueous solution * 2 ○ ○ ○ ○ Cured coating water resistance * 3 ◎ ◎ ◎ ◎ Solvent resistance * 4 ◎ ◎ ◎ ◎ Alkali resistance * 5 ◎ ◎ ○ ○

Note * 1 Irgacure 184: Ciba
Geigy photopolymerization initiator, 1-hydroxy-cyclohexyl-phenyl ketone * 2 Solubility in dilute alkaline aqueous solution: applied to tin-free steel using a wire bar to a thickness of 20 μm each, and then 1.5% carbonic acid 10 in soda solution
Then, the test piece was taken out and the coated surface was observed. ○ ・ ・ ・ ・ Complete dissolution △ ・ ・ ・ ・ ・ ・ Undissolved part remains × ・ ・ ・ ・ ・ ・ Not dissolved * 3, 4, 5 Water resistance, solvent resistance, alkali resistance: Water, acetone, 1 % Sodium hydroxide aqueous solution, and the cured coating film was rubbed 20 times and evaluated according to the degree of decrease in film thickness. ◎ ・ ・ ・ ・ ・ ・ No change ○ ・ ・ ・ ・ ・ ・ 1-5μm △ ・ ・ ・ ・ ・ ・ 5-10μm × ・ ・ ・ ・ ・ ・ 10μm or more * 6 The coating of Example 3 was irradiated with an electron beam of 5 megarats and cured. A membrane was obtained.

As is evident from Table 1, the resin composition of the present invention can be dissolved in a dilute aqueous alkali solution, and therefore has no effect on the environment or working steps. Excellent in properties and alkali resistance.

[0022]

The radiation-curable resin composition of the present invention can be dissolved in a dilute aqueous alkali solution, and the cured coating film has excellent water resistance, solvent resistance, chemical resistance, etc., and can be used as a coating agent, a photoresist, It is extremely useful in a wide range of applications such as printing inks and plate-making materials.

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁷ identification code FI C09D 175/16 C09D 175/16 (58) Field surveyed (Int.Cl. ⁷ , DB name) C08F 290/00-290/14 C08F 299/00-299/08 C08G 18/66-18/67 C09D 1/00-210/10

Claims (1)

(57) [Claims] (1) A compound (a) represented by the formula (1): (In the formula, a and b are each a number of 0 to 10, and the average value of a + b is 0.5 to 20.) A reaction product of the organic polyisocyanate (b) and the hydroxyl group-containing (meth) acrylate (c) A radiation curable resin composition comprising a certain urethane (meth) acrylate (A), a reactive diluent (B), and a photopolymerization initiator (C) as an optional component.