JPH06184269A - Optically curable resin composition having excellent adhesivity - Google Patents

Abstract

PURPOSE:To obtain the subject composition useful as a coating compound, etc., having excellent safety free from environmental pollution, comprising an aqueous polyurethane (meth)acrylate prepared by reacting a specific polyhydroxy compound, etc., to give a polyurethane (meth)acrylate, neutralizing the polyurethane (meth)acrylate and dispersing into water. CONSTITUTION:This resin composition comprises an aqueous polyurethane (meth)acrylate prepared by reacting (A) a mixture of (i) a polyhydroxy compound such as chlorinated polyhydroxy compound and (ii) a carboxyl group- containing polyhydroxy compound in an equivalent ratio of the polyhydroxy compounds of 2/8 to 8/2 with (B) a polyisocyanate compound such as 1,4- tetramethylene diisocyanate and (C) an unsaturated monohydroxy compound containing one hydroxyl group and one or more (meth)acryloyl groups in the molecule to give a polyurethane (meth)acrylate containing carboxyl group and (meth)acryloyl group, neutralizing the polyurethane (meth)acrylate, and dispersing the polymer into water.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention has excellent adhesiveness,
The present invention relates to a photocurable water-based resin composition suitable for applications such as adhesives and ink binders, and relates to a water-based resin that is pollution-free and excellent in safety.

[0002]

2. Description of the Related Art Photocurable resins are widely used for applications such as paints, adhesives and ink binders. In general, these are often used in combination with organic solvents from the viewpoint of workability, and there are problems such as the deterioration of the work environment due to organic solvents and the risk of fire due to air pollution and ignition. .

[0003]

SUMMARY OF THE INVENTION In order to solve this problem, for example, JP-A-4-211413 and JP-A-4-4113 are used.
Many photocurable aqueous resins such as No. 227623 have been proposed, but these aqueous resins do not always have sufficient adhesion to plastics. In particular, polyolefins typified by polyethylene and polypropylene and polyethylene terephthalate are difficult to adhere to, and there is a strong demand for an aqueous resin that adheres to all plastics. In view of the above-mentioned drawbacks of the conventional technique, the present inventor provides a photocurable aqueous resin composition having excellent adhesion to all plastics in order to meet strong demands of the industry.

[0004]

Means for Solving the Problems The present inventors have completed the present invention as a result of intensive studies for solving the above problems. That is, the present invention provides a mixture (A) in which the ratio of the polyhydroxy compound (a-1) and the carboxyl group-containing polyhydroxy compound is an equivalent ratio of 2: 8 to 8: 2.
A carboxyl group and (meth) acryloyl obtained by reacting a polyisocyanate compound (B) and an unsaturated monohydroxy compound (C) having one hydroxy group and one or more (meth) acryloyl group in the molecule. In an aqueous polyurethane (meth) acrylate obtained by neutralizing a polyurethane (meth) acrylate having a group with a basic compound and dispersing it in water, the polyhydroxy compound is a chlorinated polyhydroxy compound. The present invention relates to a photocurable aqueous resin composition having excellent adhesion.

The expression (meth) acrylate used in the present invention means both acrylate and methacrylate. The same applies to other expressions such as (meth) acryloyl and (meth) acrylic acid. The chlorinated polyhydroxy compound used in the present invention is obtained by a dehydration condensation reaction between a chlorinated dicarboxylic acid or acid anhydride and a diol. As the chlorinated dicarboxylic acid or acid anhydride, any one having at least one chlorine in the molecule can be used. For example, chlorendic acid (1,4,5,6,7,7-Hexachloro-endo- 5-norbornene-2,3-dic
arboxylic acid), chlorendic anhydride, tetrachlorophthalic acid, tetrachlorophthalic anhydride, tetrachlorosuccinic acid, dichlorofumaric acid, dichloroitaconic acid, octachloroadipic acid, dichloromaleic acid and the like.
These may be used alone or in combination of two or more. Examples of the diol include butanediol, hexanediol, ethylene glycol, neopentyl glycol, bisphenol A, cyclohexanedimethanol, trimethylolpropane, glycerin, pentaerythritol, and furandimethanol. These may be used alone or in combination of two or more. Further, in the dehydration condensation reaction of the chlorinated dicarboxylic acid or acid anhydride and the diol, it is possible to use a dicarboxylic acid or acid anhydride containing no chlorine in the molecule together. It is also possible to use these chlorinated polyhydroxy compounds in combination with known polyhydroxy compounds which are usually used in urethanization reaction. These chlorinated dicarboxylic acids, acid anhydrides and diols can be appropriately selected according to the purpose and application, and the required physical properties such as hardness and softness can be easily designed.

Examples of the polyisocyanate compound used in the present invention include 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, and 2,8-diisocyanate methylcapsule. aliphatic diisocyanates such as Puroeto, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, dicyclohexylmethane-4,4 ^'- diisocyanate, alicyclic diisocyanates such as methylcyclohexyl-2,4-diisocyanate, Tolylene diisocyanate, diphenylmethane diisocyanate, 1,
Aromatic diisocyanates such as 5-naphthylene diisocyanate, diphenylmethylmethane diisocyanate, and tetraalkyldiphenylmethane diisocyanate, etc. may be mentioned. These may be used alone or in combination of two or more. As the carboxyl-containing polyhydroxy compound used in the present invention, any of those capable of imparting a branched carboxyl group to the resulting polyurethane (meth) acrylate molecule can be used, but the carboxyl group content in the polyurethane (meth) acrylate In order to control, a low molecular weight one having at least one carboxyl group and having 3 to 10 carbon atoms is suitable,
For example, dimethylol butyric acid, dimethylol valeric acid, dioxymaleic acid, 2,6-dioxybenzoic acid, 2,2-
Examples thereof include dimethylolpropionic acid. Of these, 2,2-dimethylolpropionic acid is particularly preferable. The mixing ratio of the polyhydroxy compound and the carboxyl group-containing polyhydroxy compound is 2: 8 to 8: 2 in an equivalent ratio.
Is suitable, and is preferably 4: 6 to 6: 4. If the mixing ratio of the polyhydroxy compound is outside the above range of less than 2, the resin acid value becomes large and the water resistance becomes poor. On the other hand, outside the above range of more than 8, it is difficult to obtain a stable aqueous resin and the storage stability is poor.

As the basic compound used in the present invention for reacting with a carboxyl group to impart hydrophilicity, any of known compounds can be used, for example, dimethylethanolamine, diethylethanolamine,
Examples thereof include basic organic compounds such as triethylamine ammonia (water), diethanolamine and triethanolamine, and basic inorganic compounds such as caustic soda and caustic soda. Examples of the unsaturated monohydroxy compound having one hydroxy group and one or more (meth) acryloyl group in the molecule used in the present invention include 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth ) Hydroxyalkyl (meth) acrylates such as acrylate, N-hydroxymethyl (meth)
Examples thereof include N-hydroxyalkyl (meth) acrylamides such as acrylamide, polyalkylene glycol mono (meth) acrylates such as ethylene glycol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate and polypropylene glycol mono (meth) acrylate. These may be used alone or in combination of two or more.

The method for producing the aqueous polyurethane (meth) acrylate obtained by the present invention comprises reacting a mixture (A) of a polyhydroxy compound and a carboxyl group-containing polyhydroxy compound with a polyisocyanate compound (B) to prepare a prepolymer having a terminal NCO group. After obtaining the polymer, the unsaturated monohydroxy compound (C) having one hydroxy group and one or more (meth) acryloyl group in the molecule is further reacted to obtain a carboxyl group-containing polyurethane (meth) acrylate. After that, it is neutralized with a basic compound and dispersed in water to obtain an aqueous polyurethane (meth) acrylate. There is also a method of separately reacting (A), (B) and (C) at the same time, or reacting (B) and (C) and then reacting with (A). The aqueous polyurethane (meth) acrylate obtained by the present invention can use an organic solvent as needed. As these solvents, methyl ethyl ketone, methyl isobutyl ketone, acetone, ethyl acetate, butyl acetate, toluene, xylene, N-methyl-2-pyrrolidone, diethylene glycol dimethyl ether and the like are suitable. These organic solvents can be removed from the resin system by removing the solvent after making them aqueous.

In the aqueous polyurethane (meth) acrylate obtained by the present invention, various monofunctional unsaturated compounds or polyfunctional unsaturated compounds can be used as required. Examples of the monofunctional unsaturated compound include 2-ethylhexyl (meth) acrylate, dodecyl (meth) acrylate, phenoxyethyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentenyl (meth) acrylate. , Dicyclopentenyloxyethyl (meth) acrylate, acryloylmorpholine, N-vinyl-2-
Examples thereof include pyrrolidone. Examples of polyfunctional unsaturated compounds include ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate,
Neopentyl glycol di (meth) acrylate, 1,
4-butanediol di (meth) acrylate, bisphenol A. Examples thereof include ethylene oxide adduct di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trisacryloyloxyethyl isocyanurate, and dipentaerythritol hexa (meth) acrylate. These monofunctional unsaturated compounds and polyfunctional unsaturated compounds may be used alone or in combination of two or more kinds.

The photocurable aqueous resin composition of the present invention contains various additives such as a photopolymerization initiator, a sensitization aid, a surfactant, a defoaming agent, an acid value inhibitor, and a thickener, if necessary. Is compounded.
As the photopolymerization initiator, for example, Darocur 2959
A water-soluble one such as (Ciba Geigy) is preferable, but a liquid such as Darocur 1173 (Ciba Geigy) may be used. These may be used alone or in combination of two or more. The proportion of these photopolymerization initiators used is usually
1% by weight or more of the resin solid content of the resin composition of the present invention, 10
It is less than wt%, preferably 2 wt% to 6 wt% is suitable. The photocurable water-based resin composition of the present invention is used for applications such as water-based paints, water-based printing inks, water-based hard coating agents, water-based overprint varnishes, etc., by taking advantage of its excellent adhesiveness.

[0011]

EXAMPLES In order to more specifically describe the present invention, examples and comparative examples will be described below, but the present invention is not limited to these examples. Synthesis Example 1 (Synthesis of chlorinated polyol) 2000 m equipped with thermometer, stirrer, packed tower, cooling pipe, nitrogen (air) inlet pipe
In a 4-necked 4-liter flask, add 6 parts of tetrachlorophthalic anhydride.
82.6 g and 360.3 g of 1,6 hexanediol were charged, the temperature was raised to 190 ° C. while introducing nitrogen, and the esterification reaction was carried out for 10 hours. The dehydration amount was 43.5 g and the acid value was 0.4. The molecular weight of the chlorinated polyol thus obtained was 1485 (calculated from OH number). Synthesis Example 2 (Synthesis of non-chlorinated polyol) Thermometer, stirrer,
2000 equipped with a packed tower, cooling pipe, and nitrogen (air) inlet pipe
Add tetraphthalic anhydride to 54 ml four-necked flask.
9.8 g and 517.0 g of 1,6 hexanediol were charged, the temperature was raised to 190 ° C. while introducing nitrogen, and the esterification reaction was carried out for 10 hours. The dehydration amount was 67.2 g and the acid value was 0.4. The molecular weight of the polyol thus obtained was 1488 (calculated from the OH number).

Synthesis Example 3 371.3 g of the chlorinated polyol obtained in Synthesis Example 1,
Charge 2,3-dimethylolpropionic acid 33.5 g, N-methyl-2-pyrrolidone 50.3 g into a 2000 ml four-necked flask equipped with a thermometer, a stirrer, and a cooling tube.
The temperature was raised to 70 ° C. under a nitrogen stream to dissolve 2,2-dimethylolpropionic acid. Next, 166.5 g of isophorone diisocyanate was added and reacted at 70 ° C., and when the NCO group became 1/3 of the initial amount, 58.0 g of 2-hydroxyethyl acrylate and 0.1 g of hydroquinone were added to this reaction solution, While bubbling air into the reaction solution, the reaction was further performed at 70 ° C. for 6 hours to obtain a polyurethane acrylate having a carboxyl group and an acryloyl group. To the obtained polyurethane acrylate, 22.7 g of triethylamine was added, and when the inside of the system became uniform, 718.8 g of deionized water was added to make it water-based, and a nonvolatile content of 45.
A photocurable aqueous resin (A-1) having 0%, an acid value of 10 / varnish and a pH of 7.3 was obtained. Synthesis Example 4 185.7 g of the chlorinated polyol obtained in Synthesis Example 1 and 125.0 g of polyoxytetramethylene glycol having a molecular weight of 1000 (Hodogaya Chemical Co., Ltd .: PTG1000),
Charge 2,3-dimethylolpropionic acid 33.5 g, N-methyl-2-pyrrolidone 50.3 g into a 2000 ml four-necked flask equipped with a stirrer, a thermometer, and a cooling tube.
The temperature was raised to 70 ° C. under a nitrogen stream to dissolve 2,2-dimethylolpropionic acid. Next, 166.5 g of isophorone diisocyanate was added, and when the reaction was carried out at 70 ° C. and the NCO group became 1/3 of the initial amount, 58.0 g of 2-hydroxyethyl acrylate and 0.1 g of hydroquinone were added to this reaction solution, and air was added. While bubbling into the reaction solution, the mixture was reacted at 70 ° C. for 6 hours to obtain a polyurethane acrylate having a carboxyl group and an acryloyl group. 22.7 g of triethylamine was added to the obtained polyurethane acrylate, and when the inside of the system became uniform, 644.8 g of deionized water was added to make it water-soluble, and the nonvolatile content was 45.1.
%, Acid value 11.0 (varnish), PH 7.0 photo-curable aqueous resin (A-2) was obtained.

Synthesis Example 5 Chlorinated polyol 148.5 obtained in Synthesis Example 1
g, 2,2-dimethylolpropionic acid 53.6 g, N
-Methyl-2-pyrrolidone (80.5 g) was charged into a 2000 ml four-necked flask equipped with a stirrer, a thermometer, and a cooling tube, and the temperature was raised to 70 ° C under a nitrogen stream to dissolve 2,2-dimethylolpropionic acid. . Next, add 166.5 g of isophorone diisocyanate and react at 70 ° C to NC
When the O group became 1/3 of the initial amount, 2-
Hydroxyethyl acrylate (58.0 g) and hydroquinone (0.1 g) were added, and the mixture was further reacted at 70 ° C. for 6 hours while bubbling air into the reaction solution to obtain a polyurethane acrylate having a carboxy group and an acryloyl group. To the obtained polyurethane acrylate, 36.3 g of triethylamine was added, and when the inside of the system became uniform, 441 g of deionized water was added to make it water-soluble, and the nonvolatile content was 45.0.
A photocurable water-based resin (A- with an acid value of 23.5 and a pH of 7.7).
3) was obtained. Synthesis Example 6 594 g of chlorinated polyol obtained in Synthesis Example 1,
Charge 13.4 g of 2,2-dimethylolpropionic acid and 20.1 g of N-methyl-2-pyrrolidone into a 2000 ml four-necked flask equipped with a stirrer, a thermometer, and a cooling tube.
The temperature was raised to 70 ° C. under a nitrogen stream to dissolve 2.2-dimethylolpropionic acid. Next, add 166.5 parts by weight of isophorone diisocyanate and react at 70 ° C to obtain NC.
When the O group became 1/3 of the initial amount, 2-
Hydroxyethyl acrylate (58.0 parts by weight) and hydroquinone (0.1 g) were added, and the mixture was further reacted at 70 ° C. for 6 hours while bubbling air into the reaction solution to obtain a polyurethane acrylate having a carboxyl group and an acryloyl group. To the polyurethane acrylate, 9.1 g of triethylamine was added, and when the inside of the system became uniform, 996.7 g of deionized water was added to make the solution water-soluble, and a nonvolatile content of 45.
A photocurable aqueous resin (A-6) having a pH of 7.0 and a pH of 7.0 (1%) was obtained.

Synthesis Example 7 Non-chlorinated polyol 37 obtained in Synthesis Example 2
2 g, 2,2-dimethylolpropionic acid 33.5 g,
50.2 g of N-methyl-2-pyrrolidone was charged into a 2000 ml flask equipped with a stirrer, a thermometer and a condenser,
The temperature was raised to 70 ° C. under a nitrogen stream to dissolve 2,2-dimethylolpropionic acid. Next, 166.5 g of isophorone diisocyanate was added and reacted at 70 ° C., and when the NCO group became 1/3 of the initial amount, 58.0 g of 2-hydroxyacrylate and 0.1 of hydroquinone were added to this reaction solution.
g, and while bubbling air into the reaction solution at 70 ° C
Then, the reaction was carried out for 6 hours to obtain a polyurethane acrylate having a carboxyl group and an acryloyl group.
22.7 g of triethylamine was added to the obtained polyurethane acrylate, and when the inside of the system became uniform, 718.8 g of deionized water was added to make the solution water-soluble, and the nonvolatile content was 45.0%.
A photocurable aqueous resin (A-5) having an acid value of 10.0 (varnish) and a pH of 7.2 was obtained. Synthesis Example 8 141 g of the chlorinated polyol obtained in Synthesis Example 1,
52.3 g of 2,2-dimethylolpropionic acid and 81.4 g of N-methyl-2-pyrrolidone were placed in a 2000 ml four-necked flask equipped with a stirrer, a thermometer, and a cooling tube.
The temperature was raised to 70 ° C. under a nitrogen stream to dissolve 2,2-dimethylolpropionic acid. Next, 166.5 g of isophorone diisocyanate was added and reacted at 70 ° C. to obtain NCO.
At the time when the group became 1/3 of the initial amount, 58.0 g of 2-hydroxyethyl acrylate and 0.1 g of hydroquinone were added to this reaction solution, and the mixture was further reacted at 70 ° C. for 6 hours while bubbling air into the reaction solution. Then, a polyurethane acrylate having a carboxyl group and an acryloyl group was obtained. To the obtained polyurethane acrylate, 36.8 g of triethylamine was added, and when the inside of the system became uniform, 431.7 g of deionized water was added to make it water-based, and a nonvolatile content of 45.
A photocurable aqueous resin (A-6) having 0%, an acid value of 24.3 (varnish) and a pH of 7.7 was obtained.

Synthesis Example 9 Chlorinated polyol 601.9 obtained in Synthesis Example 1
g, 2,2 dimethylolpropionic acid 12.7 g, N-
Stirrer, thermometer, 19.1 g of methyl-2-pyrrolidone,
A 2000 ml four-necked flask equipped with a cooling tube was charged and heated to 70 ° C. under a nitrogen stream to dissolve 2,2-dimethylolpropionic acid. Next, 166.5 g of isophorone diisocyanate was added and reacted at 70 ° C. to obtain NCO.
At the time when the group became 1/3 of the initial amount, 58.0 g of 2-hydroxyethyl acrylate and 0.1 g of hydroquinone were added to this reaction solution, and the mixture was further reacted at 70 ° C. for 6 hours while bubbling air into the reaction solution. Then, a polyurethane acrylate having a carboxyl group and an acryloyl group was obtained. Triethylamine (8.6 g) was added to the obtained polyurethane acrylate, and when the inside of the system became uniform, deionized water (431.7 g) was added to make it water-soluble, and a nonvolatile content of 45.
A photocurable aqueous resin (A-7) having 0%, an acid value of 3.0 (varnish) and a PH of 7.1 was obtained.

Examples 1 to 7 and Comparative Examples 1 to 5 Based on the compounding contents (parts by weight) shown in Table 1, the predetermined photocurable aqueous resin obtained in the synthesis example and the predetermined monofunctional unsaturated compound or Then, the polyfunctional unsaturated compound and a predetermined photopolymerization initiator were added, and they were sufficiently mixed and stirred to obtain respective photocurable aqueous resin compositions. The following evaluations were performed on the photocurable aqueous resin compositions obtained in Examples and Comparative Examples, and the results are shown in Table-2.

[0017]

[Table 1]

[0018]

[Table 2]

The evaluation was carried out by the following method. 1) Adhesiveness Each plastic test piece is coated with a bar coater so that the coating film thickness after curing is 5 to 6 μm,
After volatilizing water in the coating film at 60 ° C / 5 minutes, a high pressure mercury lamp 80
Curing was performed at a conveyor speed of 8 m / min at a position 15 cm below the light source using an irradiation device in which w / cm was set perpendicularly to the sample passage direction. After the cellophane tape was attached to the test piece, it was peeled off at once and the peeled state of the coating film at that time was displayed.

[0020]

The photocurable water-based resin composition of the present invention has excellent adhesiveness to plastics in general.
It is clear from 2.

Claims (1)

[Claims] 1. A mixture (A) and a polyisocyanate compound (B) having an equivalent ratio of the polyhydroxy compound (a-1) to the carboxyl group-containing polyhydroxy compound (b-1) of 2: 8 to 8: 2. ), And a polyurethane having a carboxyl group and a (meth) acryloyl group obtained by reacting three members of an unsaturated monohydroxy compound (C) having one hydroxy group and one or more (meth) acryloyl group in the molecule. In an aqueous polyurethane (meth) acrylate obtained by neutralizing (meth) acrylate with a basic compound and dispersing in water, the polyhydroxy compound is a chlorinated polyhydroxy compound. Excellent photocurable water-based resin composition.