JP2000044861A - Binder for ink or coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a strong binder used for inks or coatings having good pigment dispersibility and compatibility, scarcely generating insoluble aggregates when coated, and environmentally sound by adding as a main component an acrylic copolymer prepared by copolymerizing a specific monomer mixture. SOLUTION: This binder for inks or coatings contains as a main component an acrylic copolymer obtained by copolymerizing a monomer mixture comprising (A) 40-98 wt.% of an alkyl (meth)acrylate, (B) 1-30 wt.% of a nitrogen-containing monomer having a radically polymerizable group, such as N-vinyl-2-pyrrolidone, and (C) 1-30 wt.% of a radically polymerizable monomer not containing a nitrogen atom having a hydrophilic polar group, such as hydroxyethyl (meth)acrylate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an ink for a plastic film or a binder for a paint which has good pigment dispersibility, is tough, and has excellent adhesion to a plastic film. As a binder for ink or paint suitable as

[0002]

2. Description of the Related Art
As a binder for inks and paints to be printed or applied on polyester or polyolefin films,
Vinyl chloride resins and urethane resins have been used.

A binder containing a vinyl chloride resin as a main component forms a tough coating film having good pigment dispersibility and little generation of insoluble aggregates (scrap). However, in addition to the problem of poor adhesion to plastic films,
Since toxic gas such as hydrogen chloride is generated during combustion, it is not preferable from the viewpoint of the global environment.

A binder containing a urethane resin as a main component forms a tough coating film and has good adhesion to a plastic film. However, there was a disadvantage that the pigment dispersibility was poor and insoluble aggregates were generated during coating.

[0005] In recent years, attempts have been made to solve the problems of each of the resins by using a vinyl chloride resin and a urethane resin in combination. From the viewpoint of protection, use of a vinyl chloride resin is not preferred. Therefore, it is desired to develop a binder which does not have the above-mentioned disadvantages and does not contain a vinyl chloride resin.

The present invention has been made in order to meet the above-mentioned demands, has good pigment dispersibility, has good compatibility with urethane resins, and has little occurrence of insoluble aggregates at the time of coating.
An object of the present invention is to provide a binder for an ink or a paint which is tough and has excellent adhesion to a plastic film and has environmental protection suitability.

[0007]

Means for Solving the Problems and Embodiments of the Invention The present inventors have made intensive studies to achieve the above object, and as a result, have found that alkyl (meth) acrylates (alkyl (meth)
Acrylate is a general term for alkyl acrylate and alkyl methacrylate. The same applies hereinafter), acrylic obtained by copolymerizing a monomer mixture containing a specific amount of a nitrogen-containing monomer having radical polymerizability and a radical-polymerizable monomer containing no nitrogen having a hydrophilic polar group. -Based copolymer can improve the above problem as a binder,
It has good pigment dispersibility and good compatibility with urethane resin, can be compatible with a wide range of ratios, and generates few insoluble aggregates at the time of coating, it is tough and adheres to plastic films. The present invention has been found to provide a coating film having excellent properties and also to have environmental protection suitability, and to be suitable as a binder for inks or coatings for various plastic films.

Accordingly, the present invention provides: (1) 40 to 98% by weight of an alkyl (meth) acrylate; (2) 1 to 30% by weight of a radical-polymerizable nitrogen-containing monomer; and (3) a hydrophilic polar group. An ink or paint binder characterized by comprising an acrylic copolymer obtained by copolymerizing a monomer mixture containing 1 to 30% by weight of a radical polymerizable monomer containing no nitrogen as a main component. provide.

Hereinafter, the present invention will be described in more detail. The acrylic copolymer which is the main component of the ink or paint binder of the present invention comprises a monomer mixture of the above-mentioned components (1) to (3) as a main raw material. Use as

Here, as the alkyl (meth) acrylate of the component (1), an alkyl (meth) acrylate having an alkyl group having 1 to 18 carbon atoms is preferable, and specifically, methyl (meth) acrylate, ethyl ( (Meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth)
Acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth)
Acrylate and stearyl (meth) acrylate are exemplified, and one of these can be used alone or in combination of two or more.

The amount of the alkyl (meth) acrylate is from 40 to 98% by weight of the total monomers, preferably from 55 to 90% by weight. When the amount is less than 40% by weight, the coating film becomes soft and the adhesion to the plastic film is reduced. When the amount is more than 98% by weight, the coating film becomes brittle.

The nitrogen-containing monomer having radical polymerizability as the component (2) is, for example, a compound having a vinylic double bond copolymerizable with the alkyl (meth) acrylate and containing a nitrogen atom. It is sufficient, specifically, N-
Vinyl-2-pyrrolidone, N-vinylcarbazole, 2
-Vinyl-4,6-diamino-5-triazine, 2-vinylpyridine, 4-vinylpyridine, (meth) acrylamide, N-butoxymethyl (meth) acrylamide,
Diacetone (meth) acrylamide, N-methylol (meth) acrylamide, N-isopropyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, dimethyl (meth) acrylamide, dimethylaminoethyl (meth) acrylate, vinyl Examples thereof include formamide, acryloylmorpholine, maleimide, and N-phenylmaleimide. Of these, only one type can be used alone, or two or more types can be used in combination.

The compounding amount of the nitrogen-containing monomer having radical polymerizability is 1 to 30% by weight, preferably 3 to 20% by weight of the total monomers. If the amount is less than 1% by weight, the compatibility with the urethane resin or the like decreases, and if it exceeds 30% by weight, the viscosity of the coating material increases.

The nitrogen-free radical polymerizable monomer having a hydrophilic polar group as the component (3) has a hydrophilic polar group such as a hydroxyl group, a carboxyl group, a sulfonic acid group and a phosphoric acid group. However, those having a vinylic double bond copolymerizable with the above alkyl (meth) acrylate are preferred.

The hydroxyl group-containing monomers include hydroxyalkyl (meth) acrylates such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, and 3-chloro-2-hydroxypropyl (meth) acrylate; Polyalkylene glycol mono (meth) acrylates such as glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, polyethylene glycol polypropylene glycol mono (meth) acrylate, hydroxyalkyl vinyl ethers such as hydroxyethyl vinyl ether and hydroxypropyl vinyl ether, and hydroxyethyl Mono (meth) allyl ether, hydroxypropyl (mono) allyl ether, hydroxybutyl mono (meth) allyl Hydroxyalkyl (meth) allyl ethers such as ether, 3-chloro-2-hydroxypropyl (meth) allyl ether, dialkylene glycol mono (meta) such as diethylene glycol mono (meth) allyl ether and dipropylene glycol mono (meth) allyl ether A) allyl ether, glycerin mono (meth) allyl ether, vinyl alcohol, (meth) allyl alcohol and the like. The alkyl group and the alkylene group in the hydroxyl group-containing monomer have 1 to 1 carbon atoms.
It is preferably a lower alkyl group or an alkylene group of No. 5. Further, vinyl alcohol can be produced by copolymerizing vinyl acetate and performing a saponification reaction with a caustic alkali in a solvent.

Examples of the carboxyl group-containing monomer include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid and itaconic acid, unsaturated carboxylic anhydrides such as maleic anhydride and itaconic anhydride, and dibasic acids thereof. And the like.

Examples of the sulfonic acid group-containing monomer include the following.

[0018]

Embedded image (Where M is a hydrogen atom or an alkali metal such as sodium or potassium, R is an alkyl group, preferably 1 to 5 carbon atoms)
Represents an alkyl group. )

Examples of the phosphate group-containing monomer include mono [(meth) acryloyloxyethyl] acid phosphate and mono [(meth) acryloyloxypropyl]
Acid phosphate, mono [(meth) acryloyloxybutyl] acid phosphate, mono [(meth) acryloyloxyethoxyethyl] acid phosphate, mono [(meth) acryloyloxypolyoxyethylene glycol] acid phosphate, (meth) acryloyloxyethylmethyl Acid phosphate,
(Meth) acryloyloxyethyl butyl acid phosphate, (meth) acryloyloxypropyl ethyl acid phosphate, (meth) acryloyloxyethoxyethyl methyl acid phosphate, (meth) acryloyloxy polyoxyethylene glycol butyl acid phosphate, vinyl acid phosphate, and the like Alkali metal salts and the like.

It is preferable to use a carboxyl group-containing monomer among these hydrophilic groups.

The radical polymerizable monomer having no hydrophilic polar group and containing no nitrogen may be used alone or in combination of two or more. It is 1 to 30% by weight, preferably 3 to 25% by weight in the monomer. If the blending amount is less than 1% by weight, the dispersibility decreases,
If it is more than 30% by weight, the viscosity of the coating composition will be high.

In the present invention, other radical polymerizable monomers other than those described above can be copolymerized with the above monomers, if necessary. Examples of such other radically polymerizable monomers include vinyl acetate, vinyl propionate, styrene, α-methylstyrene, acrylonitrile, ethylene, propylene, butylene, isobutylene, butadiene, glycidyl (meth) acrylate, and glycidyl allyl. Ether, cyclohexyl (meth) acrylate, alkoxyalkyl (meth) acrylate such as methoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, acetoacetoxyethyl (meth) acrylate, acetoacetoxypropyl (meth) acrylate, acetoacetoxybutyl Acetoacetoxyalkyl (meth) acrylates such as (meth) acrylate, acetoacetoxyisobutylene (meth) acrylate, methyl vinyl ether, and ethyl vinyl Ether, isobutyl vinyl ether, n- butyl vinyl ether,
Examples thereof include alkyl vinyl ethers such as 2-ethylhexyl vinyl ether, n-octyl vinyl ether, lauryl vinyl ether, cetyl vinyl ether, and stearyl vinyl ether. It is desirable that the compounding amount of these other monomers be in a range that does not impair the effects of the present invention, and it is preferable to use the other monomers in a range of 15% by weight or less of the total amount of the monomers.

In the present invention, the acrylic copolymer composed of a combination of the above units has a number average molecular weight of 5,000 to 100,000, particularly 10,000 to 100,000.
It is preferably in the range of 60,000, and it is preferable to use each monomer in combination within this range. If the number average molecular weight is lower than 5,000, the coating film may become brittle and physical properties may be degraded.
If it exceeds 000, the viscosity of the paint at a predetermined concentration becomes high, the workability becomes poor, and the handling may become difficult. For adjusting the molecular weight, a molecular weight modifier such as n-dodecyl mercaptan, thioglycol, trichloroethylene, sodium 2-chloroethanesulfonate, sodium p-chlorobenzenesulfonate, etc. can be used as necessary.

The acrylic copolymer according to the present invention can be produced by a general solution polymerization method, precipitation polymerization method, suspension polymerization method, emulsion polymerization method or the like.

In this case, the polymerization initiator used in the production of the copolymer includes persulfates such as ammonium persulfate, potassium persulfate and sodium persulfate and hydrogen peroxide; diisopropyl peroxydicarbonate, t-butyl Organic peroxide-based polymerization initiators such as hydroperoxide, benzoyl peroxide, cumene hydroperoxide and dibutyl peroxide; nitrogen-containing polymerization initiators such as azobisisobutyronitrile and azobisisovaleronitrile are exemplified. . The amount of the polymerization initiator used can be a usual amount.

These polymerization initiators may be used alone, but they may be used together with sodium acid sulfite, Rongalit, L-
A reducing agent such as ascorbic acid, saccharide or amine may be used in combination, and in any case, the polymerization can be carried out by a conventional method.

Further, in the case of solution polymerization, examples of the solvent include ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; and esters such as methyl acetate, ethyl acetate and butyl acetate.

Examples of the solvent for the precipitation polymerization include alcohols such as methanol, ethanol and isopropanol; and hydrocarbons such as hexane and pentane.

Examples of the suspension stabilizer in the case of suspension polymerization include polyvinyl alcohol-based polymers such as polyvinyl alcohol and partially saponified polyvinyl acetate; cellulose derivatives such as methyl cellulose, hydroxypropyl cellulose and carboxymethyl cellulose; polyvinyl pyrrolidone; Examples include synthetic polymers such as acrylamide, maleic acid-styrene copolymer, and maleic acid-methyl vinyl ether copolymer; and natural polymers such as starch and gelatin.

Further, as an emulsifier in the case of emulsion polymerization,
Anionic emulsifier such as alkyl or alkyl allyl sulfate, alkyl or alkyl allyl sulfonate, alkyl allyl sulfosuccinate; nonionic emulsifier such as polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl ether, polyoxyethylene carboxylate And the like.

In producing the acrylic copolymer according to the present invention, the above-mentioned monomer, polymerization initiator, suspension stabilizer,
An emulsifier or the like may be added to the polymerization system at the start of the polymerization and then polymerized, or these raw materials may be divided and added during the polymerization for polymerization. In this case, the polymerization conditions can be appropriately adjusted, but it is desirable to carry out the polymerization at 40 to 80 ° C.

After completion of the polymerization, the solution can be filtered, washed with water and dried in a usual manner. In the case of emulsion polymerization, an inorganic material such as sodium chloride, calcium chloride and sodium sulfate can be used according to a known salting-out method after polymerization. The particles may be aggregated by adding an aqueous solution of a salt or a water-soluble organic solvent or the like, followed by filtration, washing with water, and drying.

The binder of the present invention contains the above-mentioned acrylic copolymer as a main component. If necessary, a urethane resin may be used in combination with this acrylic copolymer. In this case, the acrylic copolymer has excellent compatibility with the urethane-based resin, and can be used in a wide range of ratios. Specifically, the urethane-based resin is used with respect to 100 parts by weight of the acrylic copolymer. 20 to 70 parts by weight, especially 3
0-60 parts by weight are preferred.

When an ink or paint is produced by using the binder containing the acrylic copolymer of the present invention as a main component, the amount of the acrylic copolymer is 1 to 20% by weight based on the ink or paint. It is preferable to use it within the range. As the pigment, an inorganic pigment, phthalocyanine, an organic material such as an azo type or the like can be used for carbon black, titanium white, red iron, etc., and preferably 0 to 30% by weight (0% by weight in the case of transparent) based on the coating material, It is more preferable to use 1 to 25% by weight. In this case, the acrylic copolymer is preferably dissolved in various solvents such as methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, and toluene to be used as a solution.If necessary, a plasticizer, wax, Dispersing agent, wetting agent, thickener, gelling agent, thixotropic agent, disperse or dissolve the defoaming agent,
It can be manufactured by a conventionally known manufacturing machine. When a copolymer is prepared by an emulsion polymerization method, a pigment, a water-solubilizing agent, a dispersing aid, and an elimination agent are added to the emulsion dispersion after polymerization without employing a known salting-out method after polymerization as described above. Add foaming agent, etc.
It is also possible to prepare inks or paints.

[0035]

The binder for inks or coatings of the present invention has good pigment dispersibility and good compatibility with urethane resins, and the resulting coating film is tough and adheres to plastic films. Since it has excellent properties and also has environmental protection suitability, it is practically extremely effective as an ink for various plastic films and a binder for paints.

[0036]

EXAMPLES The present invention will be described below in detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. Parts and% in each example indicate parts by weight and% by weight, respectively. Examples 1 to 9 and Comparative Examples 1 and 2
Were measured as follows. a. A 20% solution of the dried copolymer was prepared using a mixed solvent of methyl ethyl ketone / toluene = 1/1 (part), and a polyurethane resin (CA-133, trade name of Toyo Morton Co., Ltd.) was prepared.
Was mixed with a 20% solution of 1: 1 (weight), stirred for 1 hour with a stirrer, applied and dried on a glass plate, and the compatibility was visually evaluated in four steps based on the presence or absence of a hump and the degree of cloudiness. ：: excellent, ○: good, Δ: acceptable, ×: not acceptable b. Pigment dispersibility (paint) Using a mixed solvent of methyl ethyl ketone / toluene = 1/1 (part), add Deg to 100 parts of a 20% solution of the dried copolymer.
4 parts of carbon black # 100 manufactured by ussa and 80 parts of glass beads were added, and a sand mill (manufactured by Igarashi Kikai) was added.
After kneading for 3 hours at room temperature, the resulting paint was allowed to stand at room temperature for 3 days, and the separated state of the pigment was visually observed.

[Example 1] After nitrogen replacement in a polymerization vessel equipped with a stirrer, a condenser, a thermometer and a nitrogen gas inlet,
1,500 parts of deionized water, 0.35 sodium lauryl sulfate
Parts, dodecyl mercaptan 8 parts, potassium persulfate 10
And 3 parts of sodium carbonate, and heated to 70 ° C. while stirring under a nitrogen gas atmosphere. Next, a mixed solution of 880 parts of methyl methacrylate, 80 parts of N-vinyl-2-pyrrolidone, and 40 parts of hydroxypropyl acrylate was uniformly added to the polymerization vessel over 4 hours.
The reaction was carried out for an hour and cooled to room temperature to terminate the polymerization.
Then, 1,000 parts of methanol, 20% sodium sulfate 5
The copolymer was precipitated by adding 00 parts. After filtering the precipitated copolymer, it was washed twice with 1,000 parts / time of methanol and then four times with 1,000 parts / time of deionized water,
After filtration and drying, 883 parts of a copolymer (polymer 1) was obtained.

Example 2 After nitrogen replacement in a polymerization vessel equipped with a stirrer, condenser, thermometer and nitrogen gas inlet,
1,500 parts of deionized water, 0.35 sodium lauryl sulfate
Parts, dodecyl mercaptan 8 parts, potassium persulfate 10
And 3 parts of sodium carbonate, and heated to 70 ° C. while stirring under a nitrogen gas atmosphere. Next, 370 parts of methyl methacrylate, 220 parts of butyl methacrylate, 190 parts of 2-vinylpyridine, 60 parts of hydroxypropyl acrylate, and allyl-2-hydroxyethyl ether 10
A mixed solution of 0 parts and 240 parts of 25% sodium vinyl sulfonate was uniformly added to the above-mentioned polymerization vessel over 4 hours, and further reacted at 70 ° C. for 1 hour, and cooled to room temperature to complete the polymerization. Was. Then, 1,000 parts of methanol, 20%
500 parts of sodium sulfate was added to precipitate a copolymer.
After filtering the precipitated copolymer, 1,000 parts of methanol /
2 times and then 4 times with 1,000 parts / time of deionized water, filtered and dried to obtain the copolymer (Polymer 2) 7
70 parts were obtained.

[Example 3] After nitrogen replacement in a polymerization vessel equipped with a stirrer, condenser, thermometer and nitrogen gas inlet,
1,500 parts of deionized water, 1 part of partially saponified polyvinyl alcohol, and 5 parts of benzoyl peroxide were charged, and the temperature was raised to 65 ° C. while stirring under a nitrogen gas atmosphere. Next, 730 parts of methyl methacrylate, 180 parts of butyl acrylate, 40 parts of N-methylolacrylamide, 40 parts of hydroxypropyl acrylate, and 10 parts of acrylic acid
And a mixed solution of 5 parts of dodecyl mercaptan was uniformly added to the above-mentioned polymerization vessel over 5 hours, and further reacted at 65 ° C. for 1 hour, and cooled to room temperature to terminate the polymerization. After filtering the copolymer, it was washed four times with 1,000 parts / time of deionized water, filtered and dried to obtain 945 parts of a copolymer (polymer 3).

Example 4 After nitrogen substitution in a polymerization vessel equipped with a stirrer, condenser, thermometer and nitrogen gas inlet,
1,500 parts of deionized water, 1 part of partially saponified polyvinyl alcohol, and 5 parts of benzoyl peroxide were charged and heated to 70 ° C. while stirring under a nitrogen gas atmosphere. Next, 190 parts of methyl methacrylate, 520 parts of butyl methacrylate, 80 parts of N-vinyl-2-pyrrolidone,
-A mixture of 50 parts of vinylpyridine, 130 parts of hydroxypropyl acrylate, 30 parts of acrylic acid, and 5 parts of dodecyl mercaptan was uniformly added to the polymerization vessel in 5 hours, and the reaction was further performed at 70 ° C for 1 hour. After cooling to room temperature, the polymerization was terminated. After filtering the copolymer, it was washed four times with 1,000 parts / time of deionized water, filtered and dried to obtain 888 parts of a copolymer (Polymer 4).

Example 5 After nitrogen replacement in a polymerization vessel equipped with a stirrer, condenser, thermometer and nitrogen gas inlet,
1,500 parts of deionized water, 0.35 sodium lauryl sulfate
Parts, dodecyl mercaptan 1 part, potassium persulfate 10
And 3 parts of sodium carbonate, and the mixture was heated to 80 ° C. while stirring under a nitrogen gas atmosphere. Next, 390 parts of methyl methacrylate, 390 parts of butyl methacrylate, 60 parts of 2-vinylpyridine, 60 parts of hydroxypropyl acrylate, and 100 parts of allyl-2-hydroxyethyl ether
A part of the mixed solution was uniformly added to the above-mentioned polymerization vessel over 4 hours, and further reacted at 80 ° C. for 1 hour, and cooled to room temperature to complete the polymerization. Then, 1,000 parts of methanol,
500 parts of 20% sodium sulfate was added to precipitate a copolymer. After filtering the precipitated copolymer, methanol
It was washed twice with 0 parts / time and then 4 times with 1,000 parts / time of deionized water, filtered and dried to obtain 870 parts of a copolymer (Polymer 5).

Example 6 After replacing the nitrogen in a polymerization vessel equipped with a stirrer, condenser, thermometer and nitrogen gas inlet,
1,500 parts of deionized water, 1 part of partially saponified polyvinyl alcohol, and 5 parts of benzoyl peroxide were charged, and the temperature was raised to 65 ° C. while stirring under a nitrogen gas atmosphere. Next, 780 parts of methyl methacrylate, N-vinyl-2-
A mixed solution of 80 parts of pyrrolidone and 140 parts of allyl-2-hydroxyethyl ether was uniformly added to the above-mentioned polymerization vessel over 5 hours, and the reaction was further carried out at 65 ° C. for 1 hour. Finished. After filtration, the copolymer was washed four times with 1,000 parts / time of deionized water, filtered, and dried to obtain 845 parts of a copolymer (polymer 6).

Example 7 After nitrogen substitution in a polymerization vessel equipped with a stirrer, condenser, thermometer and nitrogen gas inlet,
1,500 parts of deionized water, 0.35 sodium lauryl sulfate
Parts, 0.8 parts of dodecyl mercaptan, potassium persulfate 1
0 parts and 3 parts of sodium carbonate were charged and heated to 70 ° C. while stirring under a nitrogen gas atmosphere. Next, 370 parts of methyl methacrylate, 350 parts of butyl methacrylate,
60 parts of vinylpyridine, 60 parts of hydroxypropyl acrylate, allyl-2-hydroxyethyl ether 10
A mixed solution of 0 parts and 240 parts of 25% sodium vinyl sulfonate was uniformly added to the above-mentioned polymerization vessel over 4 hours, and further reacted at 70 ° C. for 1 hour, and cooled to room temperature to complete the polymerization. Was. Then, 1,000 parts of methanol, 20%
500 parts of sodium sulfate was added to precipitate a copolymer.
After filtering the precipitated copolymer, 1,000 parts of methanol /
2 times, then 4 times with 1,000 parts of deionized water / time, filtered and dried to obtain a copolymer (polymer 7) 8
30 parts were obtained.

Example 8 After nitrogen replacement in a polymerization vessel equipped with a stirrer, condenser, thermometer and nitrogen gas inlet,
1,500 parts of deionized water, 0.35 sodium lauryl sulfate
Part, dodecyl mercaptan 0.5 part, potassium persulfate 1
0 parts and 3 parts of sodium carbonate were charged and heated to 70 ° C. while stirring under a nitrogen gas atmosphere. Next, 740 parts of methyl methacrylate, 80 parts of N-vinyl-2-pyrrolidone,
140 parts of allyl-2-hydroxyethyl ether, 25
A mixture of 160 parts of sodium vinyl sulfonate (160 parts) was uniformly added to the above-mentioned polymerization vessel over 4 hours, and the mixture was further reacted at 70 ° C. for 1 hour, and cooled to room temperature to terminate the polymerization. Thereafter, 1,000 parts of methanol and 500 parts of 20% sodium sulfate were added to precipitate a copolymer. The precipitated copolymer was filtered, washed twice with 1,000 parts / time of methanol, then four times with 1,000 parts / time of deionized water, filtered and dried to obtain the copolymer (polymer 8). 800 parts were obtained.

Example 9 After nitrogen replacement in a polymerization vessel equipped with a stirrer, condenser, thermometer and nitrogen gas inlet,
1,500 parts of deionized water, 1 part of partially saponified polyvinyl alcohol, and 5 parts of benzoyl peroxide were charged, and the temperature was raised to 65 ° C. while stirring under a nitrogen gas atmosphere. Next, a mixed solution of 500 parts of methyl methacrylate, 150 parts of butyl methacrylate, 110 parts of butyl acrylate, 150 parts of 2-vinylpyridine, 80 parts of hydroxypropyl acrylate, 10 parts of acrylic acid, and 2 parts of dodecyl mercaptan was charged into the polymerization vessel. The reaction was added uniformly over time, and the reaction was further performed at 65 ° C. for 1 hour, and cooled to room temperature to terminate the polymerization. After filtering the copolymer, deionized water 1,
It was washed four times at 000 parts / time, filtered and dried to obtain 870 parts of a copolymer (polymer 9).

[Comparative Example 1] After nitrogen replacement in a polymerization vessel equipped with a stirrer, a condenser, a thermometer and a nitrogen gas inlet,
1,500 parts of deionized water, 0.35 sodium lauryl sulfate
Parts, 0.8 parts of dodecyl mercaptan, potassium persulfate 1
0 parts and 3 parts of sodium carbonate were charged and heated to 70 ° C. while stirring under a nitrogen gas atmosphere. Next, a mixed solution of 610 parts of methyl methacrylate, 210 parts of butyl methacrylate, 140 parts of allyl-2-hydroxyethyl ether and 160 parts of 25% sodium vinyl sulfonate was uniformly added to the above-mentioned polymerization vessel over 4 hours. The reaction was further carried out at 70 ° C. for 1 hour, and cooled to room temperature to terminate the polymerization. Then, 1,000 parts of methanol, 50% sodium sulfate 50%
The copolymer was precipitated by adding 0 parts. After filtering the precipitated copolymer, it was washed twice with 1,000 parts / time of methanol and then four times with 1,000 parts / time of deionized water,
After filtration and drying, 855 parts of a copolymer (polymer 10) was obtained.

[Comparative Example 2] After nitrogen replacement in a polymerization vessel equipped with a stirrer, a condenser, a thermometer and a nitrogen gas inlet,
1,500 parts of deionized water, 1 part of partially saponified polyvinyl alcohol, and 5 parts of benzoyl peroxide were charged, and the temperature was raised to 65 ° C. while stirring under a nitrogen gas atmosphere. Next, a mixed solution of 760 parts of methyl methacrylate, 140 parts of butyl acrylate, 100 parts of N-vinyl-2-pyrrolidone, and 5 parts of dodecylmercaptan was uniformly added to the polymerization vessel in 5 hours, and further added at 65 ° C. For 1 hour and cooled to room temperature to terminate the polymerization. After filtering the copolymer, it was washed four times with 1,000 parts / time of deionized water, filtered and dried to obtain 902 parts of a copolymer (polymer 11).

The copolymers obtained in the above Examples and Comparative Examples were measured for compatibility, pigment dispersibility, and number average molecular weight. The results were as shown in Table 1.

From the results shown in Table 1, it was found that the acrylic copolymer (Example) according to the present invention was excellent in compatibility with the urethane resin and also excellent in pigment dispersibility.
Further, the obtained coating film had high strength and excellent adhesion to a plastic film.

[0050]

[Table 1]

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J038 CG141 CH031 CH041 CJ131 CJ141 CJ151 CJ161 FA012 FA062 FA112 FA121 FA152 GA03 GA06 GA13 GA14 KA08 LA01 NA11 NA12 NA27 PB11 PC08 4J039 AD06 AD08 AD10 AD12 AD22 EA44 EA48 FA02 GA34

Claims (1)

[Claims] (1) Alkyl (meth) acrylate: 40 to 98% by weight (2) Nitrogen-containing monomer having radical polymerizability: 1 to 30% by weight (3) Does not contain nitrogen having a hydrophilic polar group A binder for an ink or paint, comprising as a main component an acrylic copolymer obtained by copolymerizing a monomer mixture containing 1 to 30% by weight of a radical polymerizable monomer.