JPH05155952A - Resin composition for printing ink and its cured product thereof - Google Patents

Abstract

PURPOSE:To obtain the subject composition which is soluble in water, can be washed with water and can give a cured product excellent in adhesion, hardness, gloss and water resistance by mixing a specified epoxy (meth)acrylate with a diluent and a photopolymerization initiator as an optional component. CONSTITUTION:The objective composition is obtained by mixing an epoxy (meth)acrylate which is a reactional product of an epoxy resin of the formula (wherein R1 and R2 are each H or 1-4 C alkyl; (n) is 0 or an integer of 1 or greater; M is H or glycidyl; and when (n) is 2 or greater, then at least one of Ms is glycidyl) with (meth)acrylic acid with a diluent (e.g. glycerol triglycidyl ether acrylate) and a photopolymerization initiator (e.g. benzophenone) as an optional component. This composition is soluble in water, can be washed with water, has good curability and can give a cured product excellent in adhesion, hardness, gloss, water resistance, etc.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a specific epoxy (meth).
The present invention relates to a resin composition for printing ink containing an acrylate and a cured product thereof.

[0002]

2. Description of the Related Art In recent years, ultraviolet curable printing inks have been actively developed for the purpose of preventing pollution by making solvent-free printing inks, improving productivity by rapid curing, or improving physical properties of cured films. Various types of UV-curable printing inks have been proposed so far.

[0003]

Many of the conventional inks are satisfactory in terms of UV curing speed, but an organic solvent is used for washing the ink adhered to the rolls of a printing machine or the screen of a screen printing machine. Must be used, and there are problems of toxicity to human body and environmental pollution.

[0004]

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a radiation-curable resin composition for printing ink which can be washed with water and has excellent curability. The present invention has been completed and the present invention has been completed. That is,
The present invention has the formula (1)

[0005]

[Chemical 2]

(Wherein R ₁ and R ₂ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, n is an integer of 1 or more, and M is a hydrogen atom or a glycidyl group. However, when n is 1, M is always a glycidyl group, and when n is 2 or more, at least one M is a glycidyl group.) A reaction product of an epoxy resin and (meth) acrylic acid. The present invention relates to a resin composition for printing ink, which contains an epoxy (meth) acrylate (A), a diluent (B) and a photopolymerization initiator (C) as an optional component, and a cured product thereof.

Each constituent component of the resin composition for printing ink of the present invention will be described below. The epoxy (meth) acrylate (A) used in the present invention can be obtained by reacting the epoxy resin represented by the formula (1) with (meth) acrylic acid. The epoxy resin represented by the formula (1) is a compound represented by the formula (2)

[0008]

[Chemical 3]

It can be obtained by reacting the alcoholic hydroxyl group of the formula (wherein R ₁ , R ₂ and n have the same meanings as in formula (1)) with epichlorohydrin. The compound represented by the formula (2) is a hydantoin compound represented by the formula (3).

[0010]

[Chemical 4]

(In the formula, R ₁ and R ₂ have the same meanings as in formula (1).) For example, hydantoin, 5,5-dimethylhydantoin, 5,5-diethylhydantoin, 5
-Ethyl-5-methylhydantoin, 5,5-dipropylhydantoin, etc. and a compound represented by the formula (4)

[0012]

[Chemical 5]

(Wherein R ₁ and R ₂ have the same meanings as those in formula (1)), and 1 mol of the hydantoin compound represented by formula (3) is represented by formula (4). Compound 1.
It can be obtained by reacting at a ratio of 2 to 2 mol, preferably at 130 to 160 ° C. for usually 5 to 10 hours.

The amount of epichlorohydrin used in obtaining the epoxy resin of the formula (1) is preferably 1 equivalent or more per 1 equivalent of the alcoholic hydroxyl group in the formula (2). However, it is 15 for 1 equivalent of hydroxyl group.
If the amount is more than the double equivalent, the effect of increasing the amount is almost lost, and the volume efficiency is deteriorated, which is not preferable. It is preferable to use a quaternary ammonium salt such as tetramethylammonium chloride or benzyltrimethylammonium chloride as a catalyst when the compound represented by the formula (2) is reacted with epichlorohydrin. The amount used is 0. 1 with respect to 1 equivalent of the alcoholic hydroxyl group in the formula (2).
It is preferably used in the range of 3 to 50 g.

During the reaction, alkali metal hydroxide (eg,
It is preferable to use caustic soda, caustic potash, lithium hydroxide, calcium hydroxide, etc.). The amount of the alkali metal hydroxide used is preferably approximately equivalent to 1 equivalent of the epoxidized alcoholic hydroxyl group of the compound represented by the formula (2). The alkali metal hydroxide may be solid or aqueous solution. When using an aqueous solution, during the reaction,
The water in the reaction system can be reacted under atmospheric pressure or reduced pressure while being distilled out of the reaction system.

The reaction temperature is preferably 30 to 100 ° C. When the reaction temperature is lower than 30 ° C., the reaction becomes slow and a long-term reaction is required. When the reaction temperature exceeds 100 ° C., many side reactions occur, which is not preferable. After completion of the reaction, excess epichlorohydrin can be distilled off under reduced pressure, and then the resin can be dissolved in an organic solvent to carry out a dehydrohalogenation reaction with an alkali metal hydroxide. As the organic solvent, methyl isobutyl ketone, toluene, xylene and the like can be used, but methyl isobutyl ketone is preferably used.

The epoxy (meth) acrylate (A) used in the present invention is about 0.3 to (meth) acrylic acid based on 1 equivalent of the epoxy group of the epoxy resin represented by the formula (1).
The reaction is carried out in a ratio of 1.5 equivalents, particularly preferably about 0.5 to 1.0 equivalents, and a catalyst (for example, triethylamine, benzyldimethylamine, methyltriethylammonium chloride, triphenylstibine, triphenylstibine, triethylamine, triphenylstibine, triphenylstibine, triphenylstibine Phenylphosphine, etc.) is preferably used, and the amount of the nuclear catalyst used is preferably in the range of 0.1 to 10% by weight based on the reaction raw material mixture. In order to prevent the polymerization during the reaction, it is preferable to use a polymerization inhibitor (for example, metoquinone, hydroquinone, phenothiazine, etc.), and the amount thereof is 0.01 to 1% by weight based on the reaction raw material mixture. Preferably. The reaction temperature is usually 80 to 150 ° C. The reaction time is usually 5 to 60 hours.

The diluent (B) used in the present invention is
For example, 2-hydroxyethyl (meth) acrylate, 2
-Hydroxypropyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, N-methoxymethyl (meth) acrylic amide, isopropyl (meth) acrylamide, N-vinyl oxazolidone, N-ethoxymethyl (meth) acrylic amide, polyethylene glycol Diglycidyl ether di (meth) acrylate,
Tetraethylene glycol diglycidyl ether di (meth) acrylate, glycerin mono (meth) acrylate, glycerin triglycidyl ether tri (meth) acrylate, glycerin di (meth) acrylate, tris (2-hydroxyethyl) isocyanurate di (meth) acrylate Unsaturated-group-containing single monomers such as diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta and hexa (meth) acrylate. Examples thereof include a monomer and water. Preferred diluents include water-soluble unsaturated group-containing monomers such as polyethylene glycol diglycidyl ether diacrylate, glycerin triglycidyl ether acrylate, and tris (2-
Examples thereof include hydroxyethyl) isocyanurate di (meth) acrylate, pentaerythritol triacrylate, and water.

As the photopolymerization initiator (C) used as an optional component in the present invention, 4- (2-hydroxyethoxy) phenyl-2- (hydroxy-2-propyl) ketone, 2
-Methyl-1- [4- (methylthio) phenyl] -2-
Morpholino-propan-1-one 2,4-diethylthioxanthone, benzophenone, isopropylthioxanthone, 2-hydroxy-2-methylpropiophenone,
Benzyl dimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, 0-benzoylbenzoic acid methyl ester, P-dimethylaminobenzoic acid isoamyl ester, P-dimethylaminobenzoic acid ethyl ester, P-
Examples thereof include dimethylaminoacetophenone and P-dimethylaminobenzaldehyde. These photopolymerization initiators can be used alone or in combination of two or more. Examples of preferable photopolymerization initiator (C) include 4-
(2-Hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 2,4-diethylthioxanthone, isopropylthioxanthone, 2-hydroxy-2-methylpropiophenone, benzyldimethylketal, 1-hydroxycyclohexylphenylketone. ,
Examples thereof include benzophenone and P-dimethylaminobenzoic acid ethyl ester.

The resin composition for a printing ink of the present invention contains 100 parts of epoxy (meth) acrylate (A),
The amount of the diluent (B) used is preferably 5 to 1000 parts, and particularly preferably 10 to 500 parts. The amount of the photopolymerization initiator (C) used as an optional component is when the total amount of the components (A) + (B) is 100 parts (however, (B)
Total amount excluding the amount of water in the components) preferably 0 to 25
Parts, particularly preferably 2 to 15 parts are preferably mixed and formed.

The composition of the present invention can be obtained by mixing, dissolving and dispersing each component at room temperature to 80 ° C. If necessary, a solid water-soluble non-reactive resin such as polyvinylpyrrolidone, polyvinylpyridine, or polyvinyl alcohol may be added to the composition of the present invention to improve the performance of the cured film. Furthermore, amino resins such as melamine, polymerization inhibitors, fillers (eg, talc, calcium carbonate, silicon oxide, barium sulfate, etc.) antioxidants, ultraviolet absorbers, coloring agents such as pigments and dyes, and other auxiliaries. Organic solvents can be used together.

The printing ink composition of the present invention is printed on paper, plastic, metal, wood, etc. by means of planographic printing (offset printing), letterpress printing, screen printing, sheet-fed printing, etc., and then electron beam is applied by a conventional method. Alternatively, a cured product of the resin composition for printing ink can be obtained by curing by irradiating with ultraviolet rays. If it is electron beam irradiation, a polymerization initiator is not necessary.

[0023]

EXAMPLES The present invention will be described in more detail below with reference to examples. The parts in the synthesis examples and examples are parts by weight. Synthesis example of epoxy resin represented by formula (1)

Synthesis Example 1 548 parts of 2,4-diglycidyl-5,5-dimethylhydantoin (epoxy equivalent 137), 128 parts of 5,5-dimethylhydantoin and 2 parts of triethanolamine were mixed and stirred at 140 ° C. for 5 hours. The reaction product 67 obtained by
6 parts (epoxy equivalent: 360, softening point: 76 ° C., average value of n in formula (2): 2.1) was taken as epichlorohydrin 200
After dissolving in 0 part, 13 parts of tetramethylammonium chloride was added, and 98.5% NaO was added at 70 ° C. with stirring.
104 parts of H were added over 100 minutes. 7 more after addition
The reaction was carried out at 0 ° C for 3 hours. Then, most of the excess unreacted epichlorohydrin was distilled off under reduced pressure, the reaction product containing the by-product salt was dissolved in 1500 parts of methyl isobutyl ketone, the by-product salt was filtered and removed, and then methyl isobutyl ketone was distilled. Then, 722 parts of an epoxy resin (a) having an epoxy equivalent of 216 and a softening point of 65 ° C. was obtained. When the obtained epoxy resin (a) is calculated from the epoxy equivalent, about 1.8 of 2.1 alcoholic hydroxyl groups in the formula (2) are epoxidized.

Synthesis Example 2 822 parts of 2,4-diglycidyl-5,5-dimethylhydantoin (epoxy equivalent 137), 256 parts of 5,5-dimethylhydantoin and 3.5 parts of triethanolamine were mixed, and the mixture was mixed at 140 ° C. for 7 days. 1078 parts of a reaction product obtained by stirring for an hour (epoxy equivalent 577, softening point 90 ° C., average value of n in formula (2) is 4.3) was dissolved in 4070 parts of epichlorohydrin, and then tetramethylammonium chloride 26 Parts were added and 98.5 at 70 ° C. with stirring.
211 parts of% NaOH was added over 100 minutes. After the addition, the reaction was further performed at 70 ° C. for 3 hours. Then, most of the excess unreacted epichlorohydrin is distilled off under reduced pressure, the reaction product containing the by-product salt is dissolved in 2500 parts of methyl isobutyl ketone, the by-product salt is filtered off, and then methyl isobutyl ketone is distilled. Epoxy equivalent 239, softening point 8
1221 parts of 1 degreeC epoxy resin (b) was obtained. The epoxy resin (b) thus obtained was calculated from the epoxy equivalents to give about 3.1 of the 4.1 alcoholic hydroxyl groups in the formula (2).
Seven are epoxidized.

Synthetic Example 3 2,4-diglycidyl-5,5-diethylhydantoin (epoxy equivalent 153), 612 parts, 5,5-diethylhydantoin 156 parts, and 2.5 parts triethanolamine were mixed and mixed at 140 ° C. 768 parts of a reaction product obtained by stirring for 5 hours (epoxy equivalent 410, softening point 73 ° C., average value of n in formula (2) is 2.1) was dissolved in 2000 parts of epichlorohydrin, and then tetramethyl Add 14 parts ammonium chloride and stir at 70 ° C. for 9
104 parts 8.5% NaOH were added over 100 minutes.
After the addition, the reaction was further performed at 70 ° C. for 3 hours. Then, most of the excess unreacted epichlorohydrin was distilled off under reduced pressure,
The reaction product containing by-product salt was treated with methyl isobutyl ketone 16
It was dissolved in 00 parts and filtered to remove the by-product salt, and then methyl isobutyl ketone was distilled to obtain 833 parts of an epoxy resin (c) having an epoxy equivalent of 238 and a softening point of 64 ° C. In the obtained epoxy resin (c), about 1.9 of 2.1 alcoholic hydroxyl groups in the general formula (2) are epoxidized when calculated from the epoxy equivalent.

Synthetic Example of Epoxy (meth) acrylate Synthetic Example 4 216 parts of the epoxy resin (a) obtained in Synthetic Example 1, 68.5 parts of acrylic acid, 0.5 part of methoquinone, and 2.0 parts of triphenylphosphine were added. Charge, raise to 110 ℃, 110
The reaction was carried out at 0 ° C., and the reaction was carried out for about 20 hours until the acid value (mgKOH / g) after the reaction became 1.0 or less. The obtained product was a pale yellow solid.

Synthesis Example 5 239 parts of the epoxy resin (b) obtained in Synthesis Example 2, 68.5 parts of acrylic acid, 0.5 part of methoquinone and 2.0 parts of triphenylphosphine were charged and the reaction was carried out at 110 ° C. The reaction was carried out for about 20 hours until the acid value (mgKOH / g) after the reaction became 1.0 or less. The obtained product was a pale yellow solid.

Synthesis Example 6 238 parts of the epoxy resin (c) obtained in Synthesis Example 3, 68.5 parts of acrylic acid, 0.5 part of methoquinone and 2.0 parts of triphenylphosphine were charged and the reaction was carried out at 110 ° C. The reaction was carried out for about 20 hours until the acid value (mgKOH / g) of the reaction solution became 1.0 or less. The obtained product was pale yellow and solid.

Examples 1 to 4, Comparative Examples 1 and 2, compounded according to the compounding composition ratio (numerical values indicate parts by weight) shown in Table 1, kneaded with a three roll mill, and the resin composition for printing ink of the present invention and A comparative product was obtained. This is used to print on paper using a screen printer so that the film thickness is 20 μm, and remains on the screen. The water-based (cleanability) of the resin composition for printing ink was evaluated. 2 on paper
UV (metal halide lamp, 80W / cm ² , 1
Lamp) and cured to evaluate the adhesion, hardness and surface gloss of the cured film for water resistance.

(Evaluation) (Washability): The washability of the resin composition for printing ink remaining on the screen of the screen printing machine with water was evaluated. ○ ・ ・ ・ ・ Can be cleanly washed with water × ・ ・ ・ ・ Cannot be cleanly washed with water (Adhesiveness): Cellotape peeling test was performed. ○ ・ ・ ・ ・ No peeled part at all △ ・ ・ ・ ・ Partly peeled part was seen × ・ ・ ・ ・ Peeled completely (hardness): The surface of the cured film was nailed Rubbing and scratches were tested. ○ ・ ・ ・ ・ No scratches △ ・ ・ ・ ・ Slightly scratches × ・ ・ ・ ・ Easy to scratch

(Gloss on the surface): Gloss on the surface of the cured film ○ ・ ・ ・ ・ Good △ ・ ・ ・ ・ Slightly cloudy × ・ ・ ・ ・ ・ ・ Cloudy on the entire surface (Water resistance): Wipe the gauze with water Evaluation was made according to the degree of decrease in film thickness after rubbing 20 times. ◎ ・ ・ ・ No change ○ ・ ・ ・ ・ 1-5μm △ ・ ・ ・ ・ 5-10μm × ・ ・ ・ ・ 10μm or more

Table 1 (1) Actual Example 1 2 3 4 Epoxy acrylate obtained in Synthesis Example 4 (A) 70 35 〃 5 〃 (A) 65 〃 6 〃 (A) 70 35 KAYARAD R-114 * 1 Water (B) 30 5 30 Glycerin triglycidyl ether 30 Goal triacrylate (B) Tetraethylene glycol group Diglycidyl ether diacrylate (B) 30 Irgacure 165 (C) * 2 5 5 4- (2-hydroxyethoxy) Phenyl 77- (2-hydroxy-2-propyl) ketone Others Brightlet (pigment) * 3 5 5 5 5 Talc 25 25 25 25 Detergency ○ ○ ○ ○ Evaluation Adhesion ○ ○ ○ ○ Hardness ○ ○ ○ ○ Value Surface gloss ○ ○ ○ ○ Water resistance ◎ ◎ ◎ ◎ ◎

Table 1 (2) Comparative Example 1 2 * 4 Epoxy acrylate obtained in Synthesis Example 4 (A) 〃 5 〃 (A) 〃 6 〃 (A) KAYARAD R-114 * 1 70 70 Water distribution (B) 30 Glycerin triglycidyl ether 30 compound triacrylate (B) tetraethylene glycol group diglycidyl ether diacrylate (B) Irgacure 165 (C) * 2 5 4- (2-hydroxyethoxy) phenyl 7- (2-hydroxy- 2-Propyl) Ketone Others Brightlet (pigment) * 3 5 5 Talc 25 25 Detergency × − Evaluation Adhesion ○ − Hardness ○ − Value Surface gloss ○ − Water resistance ◎ −

Note * 1 KAYARAD R-114:
Nippon Kayaku Co., Ltd., Epicoat 828 (Okaka Shell Epoxy Co., Ltd., bisphenol A type epoxy resin) reacted with acrylic acid. * 2 Irgacure 165: Ciba Geigy, photopolymerization initiator * 3 Brightlet: Toyo Ink Co., Ltd., red pigment * 4 In the composition of Comparative Example 2, KAYARAD R-
Since 114 and water are incompatible with each other, they cannot be made into ink and cannot be evaluated.

As is clear from the evaluation results in Table 1, the resin composition for printing ink of the present invention can be washed with water, and the cured product has excellent adhesion, hardness, gloss, water resistance and the like.

[0037]

The printing ink resin composition of the present invention is soluble in water and washable with water, has good curability, and has excellent adhesion, hardness, gloss, water resistance and the like of the cured product. There is.

Claims (2)

[Claims] 1. A formula (1): (In the formula, R ₁ and R ₂ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and n is 0 or 1
It is the above integer, and M is a hydrogen atom or a glycidyl group. However, when n is 1, M is always a glycidyl group,
When n is 2 or more, at least one M is a glycidyl group. ) Epoxy (meth) acrylate (A), which is a reaction product of an epoxy resin represented by (4) and (meth) acrylic acid,
A resin composition for printing ink, comprising a diluent (B) and a photopolymerization initiator (C) as an optional component. 2. A cured product of the resin composition for printing ink according to claim 1.