JPH11246800A - Modifier for water-based coating agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a modifier which, when added to a water-based coating agent, can give a coating composition having high water retentivity, high thickenability and high thixotropy by copolymerizing a monomer mixture mainly consisting of methacrylic acid and a (meth)acrylic acid monomer. SOLUTION: This modifier comprises a copolymer comprising, based on 100 pts.wt. total monomer, 25-90 pts.wt. methacrylic acid, 1-60 pts.wt. monomer A of formula I (wherein R1 is H or CH3 ; R2 and R3 are each H, or 1 or 2C alkyl; R4 is an 8-20C alkylphenyl, a phenylalkylphenyl, or an alkyl; and n is 3-50), 1-30 pts.wt. monomer B of formula II (wherein R5 is H or CH3 ; R5 and R7 are each the same as R2 ; R8 is a 1-4C alkyl; and m is 3-100), 1-60 pts.wt. monomer C of formula III (wherein R9 is H or CH3 ; and R10 is a 1 or 2C alkyl), and 0-30 pts.wt. other ethylenically unsaturated monomers copolymerizable therewith. Here, the copolymer has a weight ratio of monomer D to monomer C of below 0.5 and has a viscosity of 50-10,000 mPa s as measured in a 2 wt.% aqueous solution of the polymer fully neutralized with NaOH at 25 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a modifier for an aqueous coating agent mainly comprising a pigment, a filler and / or a binder. More specifically, if it is used in the production of coated paper, it can be used for water-retaining agents for paper coating agents, water-based emulsions and water-based emulsion paints that can impart high operability and high coated paper properties and printability. For example, the present invention relates to a water-based emulsion and a modifier for a water-based coating agent such as a thickener for a water-based emulsion paint capable of imparting high viscosity, thixotropy and high film properties.

[0002]

2. Description of the Related Art Among water-based coating agent modifiers, sodium alginate, carboxymethylcellulose, methylcellulose, ethylcellulose, polyvinyl alcohol and the like are known as water retention agents and thickeners. In recent years, acrylic and urethane-based synthetic products have been known.

[0003]

However, with these conventional additives, productivity improvement, quality improvement, cost reduction,
It was not satisfactory for energy saving and other improvements. In the production of coated paper, in order to impart the required water retention to the paper coating paint, it is necessary to add a large amount of additives because the effect of imparting water retention is poor. There were drawbacks that adversely affected coating operability, coated paper properties, and printability, such as increasing the viscosity of the coating material and decreasing the concentration of the paper coating coating. That is, the conventional additives cannot stably operate and improve the quality in high-speed coating, which is an obstacle to high-speed coating. Also, when used for aqueous emulsions and aqueous emulsion paints, in order to impart the required high viscosity, thixotropy and water retention, it is necessary to add a large amount of additives because these effects are poor. In this case, the aqueous emulsion and the aqueous emulsion paint had the disadvantages of lowering the concentration, lowering the water resistance, and adversely affecting the physical properties of the coating film.

[0004]

Means for Solving the Problems The inventors of the present invention overcame the above-mentioned drawbacks and, as a result of intensive studies on techniques for imparting high water retention, high viscosity, and thixotropy, came to the present invention. The present inventors show that, when applied to paper coating paints, they exhibit high water retention, and significantly increase the viscosity of paper coating paints at low shear rates, suppress the viscosity at high shear rates low, and When applied to emulsions and water-based emulsion paints, the viscosity at a low shear rate is significantly increased, and it is found that limited specific compounds are effective for imparting high thixotropy and water retention to the present invention. It has been reached.

That is, the present invention relates to (1) 25 to 90 parts by weight of methacrylic acid (salt) based on 100 parts by weight of a total of monomers;
(2) The following general formula (I) Wherein R ₁ is H or CH ₃ , R ₂ and R ₃
Is H or an alkyl group having 1 to 2 carbon atoms, R ₄ is an alkylphenyl group, a phenylalkylphenyl group or an alkyl group having 8 to 20 carbon atoms, and n is 3 to 50. )
And 1 to 60 parts by weight of a monomer A represented by the following general formula (J): (Wherein R ₅ is H or CH ₃ , R ₆ and R ₇ are H or one or more selected from the group consisting of alkyl groups having 1 to 2 carbon atoms, and R ₈ is 1 or more carbon atoms.) And B is an alkyl group, and m is 3 to 100.)
1 to 30 parts by weight, and (4) the following general formula (K) (Wherein R ₉ is H or CH ₃ , and R ₁₀ is an alkyl group having 1 to 2 carbon atoms)
A copolymer of 60 parts by weight and 0 to 30 parts by weight of another ethylenically unsaturated monomer D copolymerizable therewith,
The weight ratio of monomer D / monomer C is less than 0.5, and the viscosity at 25 ° C. of a 2% by weight aqueous solution of a polymer completely neutralized with sodium hydroxide is 50 to 10,000 mPa · s. A modifier for a water-based coating agent comprising a polymer, wherein the modifier is added to a paper coating composition containing a pigment and a binder as a main component in an amount of 0.001 to 10 parts by weight based on 100 parts by weight of the pigment. A paper coating composition characterized in that the modifier is added to an aqueous emulsion paint containing a filler and a binder as a main component in an amount of from 0.001 to 1 based on 100 parts by weight of the filler.
A water-based emulsion coating composition characterized by being blended with 0 parts by weight, wherein the modifier is blended with 0.05 to 20 parts by weight with respect to 100 parts by weight of the water-based emulsion. is there.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific examples of the monomer A used in the present invention include an alkoxypolyoxyalkylene glycol represented by the following formula (I) (the alkylene oxide addition mole number is 3 to 5).
0) (Meth) acrylic acid ester, alkylphenoxypolyoxyalkylene glycol (alkylene oxide added mole number 3 to 50) (meth) acrylic acid ester and phenylalkylphenoxypolyoxyalkylene glycol (alkylene oxide added mole number 3 to 50)
(Meth) acrylic acid esters and the like. More specifically, in the formula (I), R ₄ has an alkylphenyl group, a phenylalkylphenyl group or an alkyl group having 8 to 20 carbon atoms, and (I) In the formula, (meth) acrylic acid esters of alkylene glycol in which n is 3 to 50, and these can be used alone or in combination of two or more. In the formula (I), R ₄ represents an alkylphenyl group, a phenylalkylphenyl group or an alkyl group having 8 to 20 carbon atoms, such as an ethylphenyl group, a propylphenyl group,
Butylphenyl group, pentylphenyl group, hexylphenyl group, heptylphenyl group, 2-ethylhexylphenyl group, octylphenyl group, nonylphenyl group, decylphenyl group, dodecylphenyl group, tetradecylphenyl group, cetylphenyl group, octadecyl Phenyl group,
Phenylmethylphenyl, phenylethylphenyl, phenylpropylphenyl, phenylbutylphenyl, phenylpentylphenyl, phenylhexylphenyl, phenylheptylphenyl, phenyloctylphenyl, octyl, nonyl, decyl, lauryl Group, tetradecyl group, cetyl group, stearyl group and the like. Among these, octylphenyl, nonylphenyl, dodecylphenyl, phenylethylphenyl, octyl,
Having a nonyl group, a decyl group, a stearyl group, and the like, and
In the formula (I), n is 3 to 50, and the relationship between the number of moles of ethylene glycol added n1 and the number of moles of propylene glycol added n2 is n1 <n2, where n1 is 0 or an integer of 1 or more (meta). Acrylic ester.

Specific examples of the monomer B used in the present invention include an alkoxypolyoxyalkylene glycol represented by (J) (alkylene oxide addition mole number m = 3 to 10).
0) a (meth) acrylic acid ester, more specifically, in the formula (J), R ₈ has an alkyl group having 1 to 4 carbon atoms, and in the formula (J), m is 3 to 100. (Meth) acrylate of alkylene glycol. These can be used alone or in combination of two or more. In the formula (J), R ₈ includes a methyl group, an ethyl group, a propyl group and a butyl group. Among them, preferred are those having a methyl group, an ethyl group, a propyl group and a butyl group, and in the formula (J), m is 3 to 1
And the relationship between the number of moles of ethylene glycol added m1 and the number of moles of propylene glycol added m2 is m1> m
2, m2 is a (meth) acrylate ester which is 0 or a positive number of 1 or more.

As specific examples of the monomer C used in the present invention, methyl (meth) acrylate and ethyl (meth) acrylate wherein R ₁₀ is an alkyl group having 1 to 2 carbon atoms in the formula (K) These can be used alone or in combination of two or more.

Specific examples of other copolymerizable ethylenically unsaturated monomers D include butyl (meth) acrylate,
Pentyl (meth) acrylate and hexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, decyl (meth) acrylate, (meth) ) Lauryl acrylate, tridecyl (meth) acrylate, (meth)
Alkyl (meth) acrylate having an alkyl group having 4 to 22 carbon atoms, such as tetradecyl acrylate, hexadecyl (meth) acrylate, stearyl (meth) acrylate and behenyl (meth) acrylate, acrylonitrile, styrene, and acrylic acid (Salts), unsaturated monocarboxylic acids (salts) such as crotonic acid (salt), and unsaturated dicarboxylic acids (salts) such as maleic acid (salt) and fumaric acid (salt). One or two or more of them can be used. Of these, preferred are hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, (meth) Tridecyl acrylate, stearyl (meth) acrylate and acrylonitrile are more preferred, and 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, decyl (meth) acrylate and lauryl (meth) acrylate are more preferred. Which is an alkyl (meth) acrylate having an alkyl group having 8 to 12 carbon atoms.

In the modifier for a water-based coating agent of the present invention, the ratio of methacrylic acid (salt), monomer A, monomer B, monomer C and monomer D is 100 25 to 90 parts by weight of methacrylic acid (salt) and monomer A
1 to 60 parts by weight, monomer B1 to 30 parts by weight, monomer C1
To 60 parts by weight, and the other ethylenically unsaturated monomer D copolymerizable therewith is 0 to 30 parts by weight. The weight ratio of monomer D / monomer C is less than 0.5. Preferably, methacrylic acid (salt) is 27 to 85 parts by weight, monomer A is 3 to 55 parts by weight, monomer B is 3 to 25 parts by weight, monomer C is 3 to 55 parts by weight, and monomer D is / Weight ratio of monomer C is less than 0.4, more preferably 30 to 80 parts by weight of methacrylic acid (salt), 5 to 50 parts by weight of monomer A, and 5 to 20 parts by weight of monomer B. Parts by weight and monomer C5-50
The weight and the weight ratio of monomer D / monomer C is less than 0.3. When the amount of methacrylic acid (salt) is less than 25 parts by weight, the water retention obtained is reduced, and when it exceeds 90 parts by weight, the thixotropy is reduced. In particular, the viscosity under high shear at a shear rate of 10 ⁶ / sec or more is reduced. It is undesirably high. When the amount of the monomer A is less than 1 part by weight, the viscosity increase becomes poor, and when it exceeds 60 parts by weight, the viscosity particularly under high shearing at a shear rate of 10 ⁶ / sec or more becomes too high, which is not preferable. When the amount of the monomer B is less than 1 part by weight, the effect of imparting water retention, thickening and thixotropy is poor.
0 ⁶ / high viscosity becomes too unfavorable seconds or more under high shear. When the amount of the monomer C is less than 1 part by weight, emulsion polymerization is difficult, an agglomerate is generated during the polymerization, and mechanical stability of the obtained emulsion is not preferable. If the amount exceeds 60 parts by weight, water retention, viscosity increase, and thixotropic properties decrease. When the amount of the monomer D exceeds 30 parts by weight, water retention, viscosity increase, and thixotropy decrease. If the weight ratio of monomer D / monomer C is more than 0.5, the viscosity and thixotropy decrease, especially at a low shear rate, and the thixotropy also decreases.

The base forming the salt of the modifier for an aqueous coating agent includes alkali metal salts (such as sodium, potassium and lithium salts), alkaline earth metals (such as magnesium and calcium salts), ammonium salts and amine salts ( Monoethanolamine, diethanolamine, triethanolamine, and alkyl (C1-C4) amine salts). One or two or more selected from these groups may be used. Particularly, sodium salts and potassium salts are preferred.

The modifier for an aqueous coating agent of the present invention comprises:
It is a copolymer, which may be used alone or as a mixture.

In synthesizing the modifier for water-based coating agent of the present invention, it is possible to use ordinary methods such as solution polymerization, emulsion polymerization, suspension polymerization and bulk polymerization. Preferably, a solution polymerization method and an emulsion polymerization method are used, and more preferably, an emulsion polymerization method is used.

For example, in the solution polymerization, methacrylic acid (salt), monomer A, monomer B, monomer C and / or monomer D are added to a conventional polymerization initiator in the presence of water or / and / or In an alcoholic solvent (such as methanol, ethanol and isopropyl alcohol) at 40 to 130 ° C.,
After polymerization for 1 to 15 hours, it can be easily obtained by neutralizing with a base, if necessary. As for the acidic groups such as methacrylic acid and the unsaturated monocarboxylic acid and unsaturated dicarboxylic acid of the monomer D, a method of neutralizing with a base before, during and after the polymerization, if necessary, is also possible. As a method of polymerization, the total amount of monomers such as methacrylic acid (salt), monomer A, monomer B, monomer C and / or monomer D is charged into a polymerization tank and polymerized. Alternatively, the polymerization may be carried out while being added dropwise.
Further, a part of the monomers may be charged into the polymerization tank and the polymerization may be performed while dropping some of the monomers. The polymerization initiator may be charged in its entirety in a polymerization tank for polymerization, or may be charged dropwise and polymerized. The solvent may be a combination of water and an alcohol, or may be used in combination at any ratio. Particularly preferred is a system in which the weight ratio of water to the total amount of the solvent is higher than that of alcohol. Further, the entire amount of the solvent may be charged into the polymerization tank for polymerization, or may be charged while dropping or polymerization may be performed. On the other hand, the polymerization may be performed while charging the entire amount of the solvent into the polymerization tank and removing the solvent during the polymerization.

As the polymerization initiator, 2,2'-azobisisobutyronitrile, 4,4'-azobis-4-cyanovaleric acid, 2,2'-azobis (4-methoxy-2,
4-dimethylvaleronitrile, 2,2′-azobis (2
-Methylbutyronitrile), 1,1'-azobis (cyclohexane-1-alkonitrile), 2,2'-azobis (2,4,4-trimethylpentane), dimethyl 2,
2′-azobis (2-methylpropionate), 2,
2′-azobis [2- (hydroxymethyl) propionitrile] and 1,1′-azobis (1-acetoxy-
Azo catalysts such as 1-phenylethane), persulfates such as ammonium persulfate, potassium persulfate and sodium persulfate; inorganic peroxides such as perborate and hydrogen peroxide; and ascorbic acid-hydrogen peroxide. Examples include redox catalysts and organic peroxides such as benzoyl peroxide. One or two or more selected from these groups may be used.

For example, in the emulsion polymerization, methacrylic acid (salt), monomer A, monomer B, monomer C, and / or monomer D are converted into an anionic surfactant, a nonionic surfactant, A known chain transfer agent for controlling the degree of polymerization, acetaldehyde, isopropyl alcohol, an additive such as dodecyl mercaptan or hexadecyl mercaptan is added to water, dispersed and emulsified, and a normal polymerization initiator is present at 40 to 130 ° C. After polymerizing for 1 to 15 hours,
If necessary, it can be easily obtained by neutralization with a base. As for the acidic groups such as methacrylic acid and the unsaturated monocarboxylic acid and unsaturated dicarboxylic acid of the monomer D, a method of neutralizing with a base before, during and after the polymerization, if necessary, is also possible. As a polymerization method, the entire amount of methacrylic acid (salt), monomer A, monomer B, monomer C, and / or monomer D may be charged into a polymerization tank and polymerized. It may be charged and polymerized. Further, a part of the monomers may be charged into the polymerization tank and the polymerization may be performed while dropping some of the monomers. The polymerization initiator may be charged in its entirety in a polymerization tank for polymerization, or may be charged dropwise and polymerized.

As the polymerization initiator, 2,2'-azobisisobutyronitrile, 4,4'-azobis-4-cyanovaleric acid, 2,2'-azobis (4-methoxy-2,
4-dimethylvaleronitrile, 2,2′-azobis (2
-Methylbutyronitrile), 1,1'-azobis (cyclohexane-1-alkonitrile), 2,2'-azobis (2,4,4-trimethylpentane), dimethyl 2,
2′-azobis (2-methylpropionate), 2,
2′-azobis [2- (hydroxymethyl) propionitrile] and 1,1′-azobis (1-acetoxy-
Azo catalysts such as 1-phenylethane), persulfates such as ammonium persulfate, potassium persulfate and sodium persulfate; inorganic peroxides such as perborate and hydrogen peroxide; and ascorbic acid-hydrogen peroxide. Examples include redox catalysts and organic peroxides such as benzoyl peroxide. One or two or more selected from these groups may be used.

The anionic surfactant used in synthesizing the modifier for an aqueous coating agent of the present invention includes polyoxyethylene alkyl phenyl ether sulfate, polyoxyethylene alkyl ether sulfate, α-olefin sulfate, higher alcohol sulfate, and the like. Alkali metal salts, ammonium salts or amine salts of sulfates such as fatty acid sulfates, fatty acid ester sulfates, polyoxyethylene alkylpropenyl phenyl ether sulfate and fats and oils sulfates, mono-, di-, tripolyoxyethylene alkyl phenyl ether phosphates, mono- ,
Alkali metal salts, ammonium salts or amine salts of phosphate esters such as di, tripolyoxyethylene alkyl ether phosphate esters and higher alcohol phosphate esters, paraffin sulfonates, α-olefin sulfonates, α-sulfonated fatty acids and α-sulfones And anionic surfactants represented by alkali metal salts, ammonium salts or amine salts of sulfonates such as hydrogenated fatty acid esters, and alkali metal salts of higher fatty acids. Of these, preferred are polyoxyethylene (ethylene oxide addition mole number 2 to 10).
0) Octyl phenyl ether sulfate, polyoxyethylene (2 to 100 moles of ethylene oxide added)
Nonyl phenyl ether sulfate, polyoxyethylene (ethylene oxide added mole number 2 to 100) alkyl (C6 to C22) ether sulfate, polyoxyethylene (ethylene oxide added mole number 2 to 100)
Alkali (C6-22) propenyl phenyl ether sulfate alkali metal salt, ammonium salt or amine salt, mono, di, tripolyoxyethylene (ethylene oxide addition mole number 2 to 100) octyl phenyl ether phosphate, mono, di, Tripolyoxyethylene (ethylene oxide added mole number 2 to 100) nonyl phenyl ether phosphate and mono, di, tripolyoxyethylene (ethylene oxide added mole number 2)
Alkali metal, ammonium or amine salts of alkyl (C.sub.6 to C.sub.22) ether phosphates, more preferably polyoxyethylene (ethylene oxide addition mole number: 2 to 50) octyl phenyl ether sulfate, polyoxyethylene ( Ethylene oxide addition mole number 2 to 50) nonylphenyl ether sulfate, polyoxyethylene (ethylene oxide addition mole number 2 to 50) alkyl (C6 to C18) ether sulfate, polyoxyethylene (ethylene oxide addition mole number 2 to 50) alkyl ( C6-C18 propenyl phenyl ether sulfate, mono-, di-, tripolyoxyethylene (ethylene oxide added mole number 2-5
0) octyl phenyl ether phosphate, mono,
Di, tripolyoxyethylene (ethylene oxide addition mole number 2-50) nonylphenyl ether phosphate and mono, di, tripolyoxyethylene (ethylene oxide addition mole number 2-50) alkyl (carbon number 8-1)
8) Alkali metal, ammonium and amine salts of ether phosphates.

Nonionic surfactants used in synthesizing the modifier for aqueous coating agent of the present invention include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl propenyl phenyl ether, and fatty acid polyethylene glycol. Esters, polyoxyethylene-type nonionic surfactants such as ethylene oxide adducts of partial fatty acid esters of polyhydric alcohols, fatty acid amide ethylene oxide adducts and ethylene oxide / propylene oxide copolymers, and fatty acid esters of glycerin;
Polyhydric alcohol type nonionic surfactants such as fatty acid esters of sorbitol, fatty acid esters of sorbitan, alkyl ethers of polyhydric alcohols and fatty acid amides of alkanolamines are exemplified. Among these, preferred are polyoxyethylene (2 to 100 ethylene oxide addition moles) octyl phenyl ether,
Polyoxyethylene (2 to 2 moles of ethylene oxide added)
100) Nonyl phenyl ether and polyoxyethylene (ethylene oxide addition mole number 2 to 100) alkyl (C6 to C22) ether, polyoxyethylene (ethylene oxide addition mole number 2 to 100) alkyl (C6 to C22) propenyl phenyl Ether and ethylene oxide (ethylene oxide addition mole number 2-1)
And polyoxyethylene type nonionic surfactant such as propylene oxide (propylene oxide added mole number 2 to 100) copolymer, and more preferably polyoxyethylene (ethylene oxide added mole number 2 to 5).
0) octyl phenyl ether, polyoxyethylene (2 to 50 ethylene oxide addition moles) nonyl phenyl ether, polyoxyethylene (2 to 50 ethylene oxide addition moles) alkyl (6 to 18 carbon atoms) ether, polyoxyethylene (ethylene oxide addition Examples thereof include an alkyl (2 to 50) alkyl (6 to 18 carbon atoms) propenyl phenyl ether and an ethylene oxide (ethylene oxide added 2 to 50) / propylene oxide (propylene oxide added 2 to 50) copolymer. One type and / or a mixture of two or more types selected from the group consisting of these anionic surfactants and nonionic surfactants may be used.

The total amount of the anionic surfactant and nonionic surfactant used is 1 to 25 parts by weight, preferably 3 to 25 parts by weight, based on 100 parts by weight of the total monomers of the modifier for an aqueous coating agent of the present invention. ~ 20 parts by weight, more preferably 5
１５15 parts by weight. If the amount of the anionic surfactant is less than 1 part by weight, aggregates are generated in the emulsion polymerization,
Further, the stability of the obtained aqueous dispersion of the emulsion polymer decreases. If the amount exceeds 25 parts by weight, the water resistance of the emulsion polymer is lowered and bubbles of the water-based coating agent are undesirably generated.

The viscosity at 25 ° C. of a 2% aqueous solution obtained by neutralizing the water-based coating agent modifier of the present invention with sodium hydroxide is 50 to 10,000 mPa · s. It is 50 to 5,000 mPa · s, preferably 60 to 4,500, and more preferably 70 to 4,000 mPa · s. When used in an aqueous emulsion or an aqueous emulsion paint, 2,000
〜１０10,000 mPa · s, preferably 2,500〜
9,500 mPa · s, more preferably 3,000 to 9,
000 mPa · s. In any case, if the viscosity is less than 50 mPa · s, water retention, thickening, and thixotropy are reduced, and
If it exceeds 00 mPa · s, the viscosity becomes extremely high, water retention,
It is not preferable because the thickening and thixotropic properties cannot be balanced.

The water-based coating agent modifier of the present invention comprises:
In the case of a water-soluble modifier, it can be added to the water-based coating agent as it is under stirring, and in the case of a water-insoluble modifier such as an alkali-sensitive emulsion, the pH is usually adjusted to pH 6 to 13 with an arbitrary base. It can be added to a water-based coating agent in a state of being made water-soluble. Bases include alkali metal salts (eg, sodium, potassium, lithium salts), alkaline earth metal salts (eg, magnesium, calcium salts), ammonium salts and amine salts (eg, monoethanolamine,
Diethanolamine, triethanolamine, and alkyl (C1-C4) amine salts). Using one or two or more selected from these groups, usually at pH
Adjust to 6-13 and use. The method of pH adjustment may be such that the aqueous coating agent modifier of the present invention is adjusted to the desired pH with a base in advance and added to the aqueous coating agent, or the aqueous coating agent is adjusted to the desired pH in advance. A necessary amount of a base may be added, and the modifier for an aqueous coating agent of the present invention may be added thereto with stirring.

The water-based coating agent modifier of the present invention comprises:
Effective for imparting water retention, thickening, and thixotropy of water-based coating agents mainly containing pigments or fillers and / or binders, and water-holding agents for water-based paper coating paints, water-based emulsions and water-based emulsion paints, thickeners and thixotropes It is particularly effective as an agent. Specifically, it is optimal for high-speed coating of water-based paper coating paints, which is a technical trend in the papermaking industry. It is ideal for high-speed coating of water-based emulsions and high-speed paint coating with implants such as ceramic siding boards, which is a technical trend in the water-based emulsion paint industry.

Examples of pigments in these aqueous coating agents include inorganic pigments such as clay, calcium carbonate, titanium oxide, satin white, barium sulfate, talc, zinc oxide, gypsum, silica, ferrite, and organic pigments such as polystyrene plastic pigment. Pigments may be used alone or in combination.

The binder in these aqueous coating agents includes natural binders such as starch, modified starch, casein, modified soy protein, styrene butadiene latex, carboxyl modified styrene butadiene latex, acrylic resin emulsion, vinyl acetate resin emulsion, and vinyl chloride. Resin emulsion, acrylic styrene resin emulsion, silicone resin emulsion, urethane resin emulsion, epoxy resin emulsion, fluororesin emulsion, ABS latex,
Synthetic binders such as NBR latex and CR latex are exemplified.

The amount (in terms of solid content) of the water-based coating agent modifier of the present invention is usually from 0.001 to 1 per 100 parts by weight of the pigment or filler in the water-based coating agent.
0 parts by weight, preferably 0.01 to 5 parts by weight, more preferably 0.05 to 3 parts by weight. The amount is usually 0.001 to 10 parts by weight, preferably 0.01 to 8 parts by weight, more preferably 0.05 to 6 parts by weight, based on 100 parts by weight of the binder. If the amount is less than 0.001 part by weight, the effect of imparting water retention, thickening and thixotropic properties is poor, and
If it exceeds 0 parts by weight, the viscosity under a high shear rate becomes too high, which is not preferable.

The modifier for an aqueous coating agent of the present invention comprises:
An antioxidant, an ultraviolet absorber, a water-proofing agent, an antiseptic / antifungal agent, a defoamer, a dispersant, a deodorant, a fragrance, a dye, a pigment, and the like may be contained or used in combination.

When the modifier for an aqueous coating composition of the present invention is used as a modifier for an aqueous paper coating composition containing a pigment and a binder as a main component, the amount used (in terms of solid content) is determined in the aqueous paper coating composition. Is usually 0.00
It is 1 to 10 parts by weight, preferably 0.01 to 5 parts by weight, more preferably 0.05 to 3 parts by weight. 0.0
If the amount is less than 01 parts by weight, the effect of imparting water retention and the effect of increasing the viscosity are poor, and if it exceeds 10 parts by weight, the viscosity under a high shear rate is undesirably too high. The paper coating composition using the water-based coating agent modifier of the present invention is usually used in the form of an aqueous dispersion, and if necessary, other additives, for example, a dispersant such as sodium polyacrylate, a fatty acid ester. Antifoaming agents such as, lubricating agents such as calcium stearate,
Water-proofing agents such as glyoxal, urea resin or polyamide polyamine resin, wetting agents, preservatives and fluorescent dyes are added. Water retention agents and thickeners other than the water-based coating agent modifier of the present invention, for example, sodium alginate, carboxymethylcellulose, hydroxyethylcellulose, methylcellulose, ethylcellulose, polyvinyl alcohol and the like can be used in combination, but the amount of these used Preferably, it is used in less than 50% by weight, more preferably 10% by weight or less, of the modifier for water-based coating agent of the present invention. When the content is 50% by weight or more, the characteristics of the modifier for a water-based coating agent of the present invention are not utilized, and the effect of imparting water retention and increasing viscosity is significantly reduced.

The paper coating composition can be coated on the paper by a known method, for example, with an air knife coater, curtain flow coater, blade coater, roll coater, rod coater or the like. After coating, it is dried and finished with a calender ring or super calender ring as required. The coating temperature is usually 10-60 ° C,
The drying temperature is usually 90 to 150 ° C, and the temperature of the calender ring, super calender ring or soft nip calender ring is usually 30 to 200 ° C.

When the modifier for an aqueous coating agent of the present invention is used as a modifier for an aqueous emulsion paint mainly comprising a filler and a binder, or when it is used as a modifier for an aqueous emulsion mainly comprising a binder, The amount (in terms of solid content) of the modifier for an aqueous coating agent of the present invention is usually 0.0 with respect to 100 parts by weight of a binder in an aqueous emulsion paint and an aqueous emulsion.
The amount is from 0.01 to 10 parts by weight, preferably from 0.01 to 8 parts by weight, more preferably from 0.05 to 6 parts by weight. 0.0
If it is less than 01 parts by weight, the effect of imparting viscosity, thixotropy and water retention is poor, and if it exceeds 10 parts by weight, the viscosity under a high shear rate becomes too high and the water resistance is undesirably reduced. Aqueous emulsion paint and aqueous emulsion using the aqueous coating agent modifier of the present invention,
Usually used in the form of an aqueous dispersion, if necessary, other solvents, antifreezing agents, dispersants, defoamers, wetting agents, film-forming aids, lubricants, thickeners, water-proofing agents, preservatives And a fluorescent dye. Thickeners other than the aqueous coating agent modifier of the present invention, for example, hydroxyethyl cellulose, carboxymethyl cellulose, methyl cellulose,
Ethyl cellulose, sodium alginate, polyvinyl alcohol, and the like can be used in combination, but the amount of these used is preferably less than 50% by weight, more preferably 10% by weight of the aqueous coating agent modifier of the present invention. It is used below. When the content is 50% by weight or more, the characteristics of the modifier for a water-based coating agent of the present invention are not utilized, and the effects of increasing viscosity, thixotropy and water retention are remarkably reduced.

The water-based emulsion paint can be coated on the substrate by a known method, for example, by brush coating, spray coating, roll coating, curtain flow coater coating, airless coating, or electrostatic coating.

[0032]

EXAMPLES The present invention will be further described with reference to the following examples, but the present invention is not limited to these examples. In the following examples, "part" means "part by weight" and "%" means "% by weight".

Example 1 In a glass reaction vessel equipped with a dropping funnel, a reflux condenser, a stirrer, and a thermometer, 600 parts of water, methacrylic acid 164.
7 parts, laurylphenoxypolypropylene glycol (propylene oxide added mole number 10) methacrylic acid ester 43.2 parts, ethoxy polyoxyethylene propylene glycol (ethylene oxide added mole number 30.
Propylene oxide added mole number 10) 43.2 parts of methacrylic acid ester, methyl methacrylate 18.9 parts, polyoxyethylene (ethylene oxide added mole number 20) nonylpropenyl phenyl ether sulfate sodium salt 2.0 parts and polyoxyethylene (ethylene oxide) 25 mol adduct) 28.0 parts of octyl ether sulfate sodium salt were charged, and 100 parts of a 0.2% aqueous solution of ammonium persulfate was added dropwise from a dropping funnel at a constant rate over 3 hours with stirring to cause a reaction. Reaction temperature is 80
１００100 ° C. was maintained. After the dropping was completed, the temperature was kept at the same temperature for 3 hours (referred to as aging), cooled to 30 ° C, and taken out.
% As a white emulsion having a viscosity of 10 mPa · S.

Example 2 In the same manner as in Example 1, water 6 was added to a glass reaction vessel.
00 parts, methacrylic acid 142.8 parts, nonylphenoxypolyethylene propylene glycol (ethylene oxide addition mole number 5, propylene oxide addition mole number 15)
27.5 parts of methacrylic acid ester, methoxypolyoxyethylene glycol (ethylene oxide addition mole number 2
5) 22.0 parts of methacrylic acid ester, 38.5 parts of ethyl acrylate, 38.5 parts of methyl methacrylate, 5.5 parts of 2-ethylhexyl acrylate, polyoxyethylene (25 mol adduct of ethylene oxide) octyl phenyl ether phosphorus 10.0 parts of disodium salt of acid monoester and 15.0 parts of polyoxyethylene (ethylene oxide 25 mol adduct) lauryl ether are added, and 100 parts of a 0.2% aqueous solution of ammonium persulfate is added dropwise with stirring, followed by reaction, aging and cooling. Thus, a water-based coating agent modifier as a white emulsion having a concentration of 30% and a viscosity of 9 mPa · S was obtained.

Example 3 In the same manner as in Example 1, water 6 was added to a glass reaction vessel.
00 parts, methacrylic acid 109.1 parts, phenylpropylphenoxy polypropylene glycol (propylene oxide addition mole number 15) acrylic acid ester 14.0 parts,
Butoxypolyoxyethylene / propylene glycol (ethylene oxide 30 mol adduct / propylene oxide 20 mol adduct) methacrylate 25.2
Parts, methyl acrylate 47.6 parts, ethyl acrylate 5
6.0 parts, lauryl acrylate 28.0 parts, polyoxyethylene (ethylene oxide 25 mol adduct) stearyl ether sulfate sodium salt 10.0 parts and polyoxyethylene (ethylene oxide 25 mol adduct) lauryl ether 10.0 parts 100 parts of a 0.2% aqueous solution of ammonium persulfate was added dropwise with stirring, and the reaction,
After aging and cooling, a water-based coating agent modifier as a white emulsion having a concentration of 30% and a viscosity of 9 mPa · S was obtained.

Example 4 In the same manner as in Example 1, water 6 was added to a glass reaction vessel.
00 parts, 76.1 parts of methacrylic acid, 28.6 parts of methacrylic acid ester, 28.2 parts of methacrylic acid ester, and methoxypolyoxyethylene glycol (90 moles of ethylene oxide) 14.1 parts of acrylic ester, 67.6 of ethyl acrylate
Parts, 67.6 parts of ethyl methacrylate, 28.2 parts of 2-ethylhexyl acrylate, 28.2 parts of 2-ethylhexyl methacrylate, 9.7 parts of polyoxyethylene (20 moles of ethylene oxide added) nonylpropenyl phenyl ether and poly 8.3 parts of sodium oxyethylene (22 mol adduct of ethylene oxide) lauryl ether sulfate sodium salt were added, and 100 parts of a 0.2% aqueous solution of ammonium persulfate was added dropwise with stirring, followed by reaction, aging, and cooling to a concentration of 30% and a viscosity of 10 mPa · A water-based coating agent modifier as a white emulsion of S was obtained.

Example 5 In the same manner as in Example 1, water 6 was added to a glass reaction vessel.
00 parts, methacrylic acid 220.8 parts, lauroxypolyoxypropylene glycol (propylene oxide 10 mol adduct) methacrylic acid ester 15.6 parts, ethoxypolyoxyethylene glycol (ethylene oxide 25
15.6 parts of methacrylic acid ester, 7.8 parts of ethyl acrylate, 20.5 parts of sodium salt of polyoxyethylene (ethylene oxide 15 mol adduct) nonylphenyl ether phosphoric acid diester and 18 mol of polyoxyethylene (ethylene oxide 18 mol) Addition product) 19.5 parts of nonylphenyl ether phosphoric acid diester potassium salt were added, and a 0.2% aqueous solution of ammonium persulfate was added with stirring.
0 parts were dropped, reacted, aged and cooled to a concentration of 30% and a viscosity of 3
An aqueous coating agent modifier as a white emulsion of 5 mPa · S was obtained.

Comparative Example 1 In the same manner as in Example 1, water 6 was added to a glass reaction vessel.
00 parts, methacrylic acid 55.6 parts, nonylphenoxypolyoxyethylene propylene glycol (ethylene oxide 5 mol adduct propylene oxide 15 mol adduct) methacrylic acid ester 55.6 parts, ethoxy polyoxyethylene glycol (ethylene oxide 25 mol adduct 6.) 55.6 parts of methacrylate, 27.8 parts of ethyl acrylate, 27.8 parts of methyl methacrylate, 55.6 parts of lauryl methacrylate, polyoxyethylene (ethylene oxide 25 mol adduct) stearyl ether sulfate sodium salt 0 parts and 15.0 parts of polyoxyethylene (48 moles of ethylene oxide adduct) octyl ether were added, and 0.2% of potassium persulfate was stirred.
100 parts of the aqueous solution was dropped, reacted, aged and cooled to a concentration of 30.
%, A water-based coating agent modifier as a white emulsion having a viscosity of 9 mPa · S.

Comparative Example 2 In the same manner as in Example 1, water 6
00 parts, methacrylic acid 251.6 parts, methoxy polyoxyethylene glycol (ethylene oxide 25 mol adduct) methacrylic acid ester 5.2 parts, 2-ethylhexyl acrylate 7.8 parts, polyoxyethylene (ethylene oxide 25 mol adduct) 20.0 parts of stearyl ether sulfate sodium salt and 20.0 parts of polyoxyethylene (ethylene oxide addition mole number: 10) nonylpropenyl phenyl ether sulfate sodium salt were added, and a 0.2% aqueous solution of potassium persulfate in 100 parts was stirred.
The reaction was stopped due to the formation of aggregates during the polymerization. Next, solution polymerization was attempted. 700 parts of water and 20 parts of isopropyl alcohol were placed in a glass reaction vessel equipped with a dropping funnel, a reflux condenser, a distillation apparatus, a stirrer, and a thermometer.
0 parts were added, and 47.5 parts of methacrylic acid and methoxypolyoxyethylene glycol (ethylene oxide 2
(5 mol adduct) A mixture of 1.0 part of methacrylic acid ester and 1.5 parts of 2-ethylhexyl acrylate and 15 parts of a 0.2% aqueous solution of potassium persulfate were dropped at a constant rate over 5 hours to react. . The reaction temperature was maintained at 85 to 100 ° C. After maintaining the same temperature for 3 hours after the completion of dropping (ripening), isopropyl alcohol was removed while adding water,
Upon cooling to 30 ° C., a transparent liquid aqueous coating agent modifier having a concentration of 2% and a viscosity of 5500 mPa · S was obtained.

Comparative Example 3 In the same manner as in Example 1, water 6 was added to a glass reaction vessel.
00 parts, 85.2 parts of methacrylic acid, 2.7 parts of acrylate of nonylphenoxypolyoxyethylene glycol (addition of 20 moles of ethylene oxide), 2.7 parts of butoxypolyoxyethylene / propylene glycol (addition of 30 moles of ethylene oxide and 20 moles of propylene oxide) Product) 96.2 parts of methacrylate, 33.0 parts of ethyl methacrylate, 5.5 of 2-ethylhexyl acrylate
Part, stearyl acrylate 22.0 parts, polyoxyethylene (ethylene oxide 15 mol adduct) nonylphenyl ether phosphate monoester disodium salt 17.5 parts
And 7.5 parts of polyoxyethylene (25 mol adduct of ethylene oxide) lauryl phenyl ether, 100 parts of a 0.2% aqueous solution of ammonium persulfate was added dropwise with stirring, reacted, aged and cooled to a concentration of 30% and a viscosity of 22 mP.
An aqueous coating agent modifier as an a · S white emulsion was obtained.

Comparative Example 4 In the same manner as in Example 1, water 6
00 parts, methacrylic acid 141.7 parts, octylphenoxypolyoxyethylene / propylene glycol (ethylene oxide 50 mol adduct / propylene oxide 10 mol adduct) methacrylic acid ester 27.8 parts, methoxy polyoxypropylene glycol (propylene oxide 10 mol) Adduct) 27.8 parts of acrylic ester, 27.8 parts of methyl acrylate, 52.8 parts of ethyl methacrylate
10.3 parts of polyoxyethylene (ethylene oxide 15 mol adduct) nonylphenyl ether phosphoric acid monoester disodium salt 10.3 parts and polyoxyethylene (ethylene oxide 25 mol adduct) lauryl ether
9 parts were added, and 100 parts of a 0.2% aqueous solution of ammonium persulfate was added dropwise with stirring, followed by reaction, aging, and cooling to a concentration of 30%.
An aqueous coating agent modifier as a white emulsion having a viscosity of 10 mPa · S was obtained.

Comparative Example 5 In the same manner as in Example 1, water 6 was added to a glass reaction vessel.
00 parts, methacrylic acid 82.5 parts, dodecoxypolyoxyethylene propylene glycol (ethylene oxide 2
5 mol adduct / propylene oxide 5 mol adduct) 96.3 parts of acrylate, 41.3 decyl acrylate
9. parts, hexyl methacrylate 55.0 parts, polyoxyethylene (ethylene oxide 41 mol adduct) octyl phenyl ether phosphoric acid monoester disodium salt
0 parts and polyoxyethylene (ethylene oxide 61
Addition of 14.8 parts of stearyl ether sulfate sodium salt, 100 parts of a 0.2% aqueous solution of ammonium persulfate was added dropwise with stirring, reaction, aging, and cooling to give a white emulsion having a concentration of 30% and a viscosity of 10 mPa · S. A certain water-based coating agent modifier was obtained.

Comparative Example 6 Sodium alginate (Kimitsu Algin L manufactured by Kimitsu Kasei Co., Ltd.)
A 5% aqueous solution of -2) was prepared to obtain a water-based coating agent modifier.

Comparative Example 7 A 5% aqueous solution of carboxymethylcellulose (Cerogen PR manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was prepared to obtain a water-based coating agent modifier.

Comparative Example 8 Hydroxyethyl cellulose (manufactured by Daicel Chemical Industries, Ltd.
P-800) was obtained to obtain a water-based coating agent modifier.

The relative viscosities of the 2% aqueous solutions of Examples 1 to 5 and Comparative Examples 1 to 5 adjusted to pH 9 with sodium hydroxide at 25 ° C. using an Ubbelohde viscometer are shown in Table 1.

[0047]

[Table 1]

The performance of Examples 1 to 5 and Comparative Examples 1 to 8 was evaluated by the following methods. The results are shown in Tables 2, 3 and 4.

Evaluation Example 1 (1) Formulation of Paper Coating Paint (Parts: In terms of solid content, meaning parts by weight) 1 Pre-dispersed clay [ENGELHARD MINERA
70 parts of L & CHEMICALS, UW-90], heavy calcium carbonate [FMT-90], manufactured by FIMATECH, Inc. 15
Parts, light calcium carbonate (manufactured by Okutama Industry Co., Ltd., Tamapearl TP-222-HS) 15 parts, dispersant (manufactured by San Nopco, SN dispersant 5040) 0.2 part,
0.1 to 0.3 parts of sodium hydroxide, 3 parts of phosphoric acid-modified starch (manufactured by Japan Food Processing Co., Ltd., MS-4600), 3 parts of SBR latex (manufactured by Nippon Synthetic Rubber Co., Ltd., JSR0696) 1
2 parts, lubricant [Nopcoat C-1 manufactured by San Nopco Co., Ltd.]
04-HS] and 0.2 parts of a modifier for water-based coating agents at a pH of 9.0 and paint concentrations of 63 and 65.
% Paper coatings were made.

(2) Physical properties of paper coating paint Low shear viscosity: BM type viscometer, 60 rp, manufactured by Tokyo Keiki Co., Ltd.
m, measured at 25 ° C. The higher the viscosity, the better. High shear viscosity: Hercules viscometer manufactured by Kumagai Riki, 880
Measured at 0 rpm and 25 ° C. The lower the viscosity, the better. Water retention: Caltech Scientific Co., Ltd.
, A gravimetric water retention meter, a pressure of 0.5 kg / m ² , and a dehydration amount for a pressurization time of 30 seconds. The smaller the numerical value, the better. Coating aptitude: Coating concentration a63% and b65 at a coating speed of 1,500 m / min using CLC-6000 manufactured by Waferuser.
% Paper coating paint and dried. It is preferable that the coating amount does not increase as much as possible even when the paper coating concentration increases. That is, the smaller the coating amount ratio of b / a, the better. in this case,
Since coating can be performed without increasing the blade pressure, there is no occurrence of paper breakage, and a bulky coating layer is obtained,
Improves white paper gloss, smoothness, print gloss, and water-absorbing ink adhesion after super calendering. Coating unevenness: The coating unevenness of paper coated with a coating concentration b of 65% was visually determined. ：: no coating unevenness, △: slight coating unevenness, ×: many coating unevenness White paper gloss: coated paper having a coating amount of 10 gr / m ² at 60 ° C. and a linear pressure of 80 kg / cm using a super calender. After passing twice,
It was conditioned and measured. Print gloss, dry pick, wet pick, water-absorbing ink depositability: Printed with Mei Seisakusho's RI-1 type printability tester. The dry pick, the wet pick, and the ink-adhesiveness of the ink were evaluated by a five-point method. The higher the value, the better. Smoothness: Measured by Oken type smoothness tester. The larger the value, the higher the smoothness and the better.

[0051]

[Table 2]

Evaluation Example 2 (1) Formulation of aqueous emulsion (part: solid content, meaning parts by weight) Acrylic emulsion [commercial product: concentration 48%] 100
Part, defoamer [Dehydran 1 manufactured by Henkel KGaA Co., Ltd.]
620] A water-based emulsion having a solid content of 43% was prepared by mixing 0.1 part and a water-based coating agent modifier 0.5 part. With the above composition, 30 with a tabletop homogenizer
After stirring at 00 rpm for 5 minutes, the mixture was allowed to stand for 12 hours.

(2) Physical properties of aqueous emulsion Low shear viscosity: BM type viscometer, 60 rp, manufactured by Tokyo Keiki Co., Ltd.
m, measured at 25 ° C. The higher the viscosity, the better. High shear viscosity: Hercules viscometer manufactured by Kumagai Riki 440
Measured at 0 rpm and 25 ° C. The lower the viscosity, the better. Water retention: Caltech Scientific Co., Ltd.
, A gravimetric water retention meter, a pressure of 0.5 kg / m ² , and a dehydration amount for a pressurization time of 30 seconds. The smaller the numerical value, the better.

[0054]

[Table 3]

Evaluation Example 3 (1) Blending of water-based emulsion paint (part: means blending ratio) Titanium dioxide [manufactured by Teica Co., Ltd., JR-600A] 35
0 parts, calcium carbonate [Escalon, manufactured by Sankyo Flour Milling Co., Ltd.
# 2000] 100 parts, dispersant [manufactured by San Nopco Co., Ltd.
Nopco Spars 44-C] 4 parts, antifoaming agent [Henkel K
3 parts of Dehydran 1620 manufactured by GaAs Co., Ltd., preservative [Nopcoside SN-215 manufactured by San Nopco Co., Ltd.]
2.4 parts, water 100 parts, emulsion [Mitsubishi Chemical BAS
F. Co., Ltd., Acronal 295DN] 605 parts, propylene glycol 30 parts, film-forming aid (Texanol, Eastman Chemical Company, 15 parts) and water-based coating agent modifier 12 parts for line coating of building materials Aqueous emulsion paint was prepared.

(2) Physical properties of aqueous emulsion paint Low shear viscosity: BM type viscometer, 60 rp, manufactured by Tokyo Keiki Co., Ltd.
m, measured at 25 ° C. The higher the viscosity, the better. Water retention: Caltech Scientific Co., Ltd.
, A gravimetric water retention meter, a pressure of 0.5 kg / m ² , and a dehydration amount for a pressurization time of 30 seconds. The smaller the numerical value, the better. Coating aptitude: Adjusted to a coating specific gravity of 1.2 at a coating speed of 40 m / sec by curtain flow coater coating, and a viscosity of about 1
After applying the water-based emulsion paint adjusted to 0 mPa · s, 8
Force dry at 0 ° C. for 10 minutes. At this time, it is preferable that there is no curtain break, foam, uneven coating, uneven color, and the like, and that the coating film after forced drying has no mud cracks (cracks). Uneven coating: The uneven coating of the object to be coated was visually determined. ：: no coating unevenness, Δ: slight coating unevenness, ×: many coating unevenness Mad crack: Mud crack (crack) of the coating film of the object was visually judged. ○: No mud cracks, △: Slight mud cracks generated, ×: Many mud cracks

[0057]

[Table 4]

[0058]

When the modifier for an aqueous coating composition of the present invention is used as a modifier for an aqueous paper coating composition mainly composed of a pigment and a binder, the viscosity of the aqueous paper coating composition under low shear can be reduced. Viscosity can be increased, and the viscosity of the water-based paper coating composition can be suppressed to a low level under high shear at a shear rate of 10 ⁶ / sec or more. In addition, it has an effect that has not been known so far, that it has excellent high water retention. By these functions, the modifier for water-based coating agent of the present invention can easily apply to the base paper at the time of applying the water-based paper coating paint, can make the profile uniform, and can easily adjust the coating amount. At the time of scraping, it has an effect of being able to adjust a water-based paper coating material having excellent coating suitability such as reduction of streak, bleeding and blade abrasion and having physical properties suitable for high-speed coating. Further, the water-based coating agent modifier of the present invention suppresses migration of a binder or the like based on the function of imparting water retention, reduces the blade pressure based on the function of reducing viscosity under high shear, or coats after application and scraping. It has the effect of accelerating the immobilization of paint, and can form a uniform and bulky coating layer without coating unevenness, and is excellent in smoothness, glossiness of white paper, print gloss, and adhesion of water-absorbing ink. A coated paper can be obtained. Due to the above effects, the water-based coating agent modifier of the present invention is used in the coating technology trend of the paper manufacturing industry from the viewpoint of improving productivity in production of coated paper, improving quality, reducing costs, saving energy, and the like. It realizes high-speed coating of a certain water-based paper coating paint and can impart good coating paint physical properties, high operability, high coated paper physical properties, and printability, and is suitable for the production of coated paper.

When the modifier for an aqueous coating agent of the present invention is used as a modifier for an aqueous emulsion containing a binder as a main component, the aqueous emulsion is thickened so that the viscosity of the aqueous emulsion under low shear can be easily adjusted. Under high shear at a shear rate of 10 ⁴ / sec or more, the aqueous emulsion has a thixotropic property so that the viscosity of the emulsion can be reduced, and has an effect that has not been known in the art, such as high water retention. I have. ADVANTAGE OF THE INVENTION The modifier for aqueous coating agents of the present invention can easily adjust the viscosity of an aqueous emulsion, is excellent in coating suitability, and has the effect of adjusting an aqueous emulsion having physical properties suitable for high-speed coating. Furthermore, the modifier for an aqueous coating agent of the present invention has an effect of facilitating viscosity adjustment, relaxation of shear between emulsion particles based on the function of imparting thixotropic properties and water retention, and easy adjustment of viscosity. Can form a uniform coating layer without coating unevenness even with a base material that easily penetrates water. Due to the above effects, the water-based coating agent modifier of the present invention has an effect of adjusting a water-based emulsion having physical properties suitable for high-speed coating in a line coating of a water-based emulsion, thereby improving productivity. High-speed line coating with implants, which is a technical trend in the adhesive industry from the viewpoints of quality improvement, cost reduction, energy saving, etc., realizes good emulsion physical properties, high operability and high coated physical properties It is suitable for coating water-based emulsions.

On the other hand, when the modifier for an aqueous coating agent of the present invention is used as a modifier for an aqueous emulsion paint mainly composed of a filler and a binder, the viscosity of the aqueous emulsion paint under low shear can be easily adjusted. The aqueous emulsion paint has a thixotropic property so that the viscosity of the aqueous emulsion paint can be reduced under a high shearing rate of 10 ⁴ / sec or more, and has a high water retention property, which has not been known in this field. It has the effect. ADVANTAGE OF THE INVENTION The modifier for water-based coating agents of the present invention can easily adjust the viscosity of a water-based emulsion paint, is excellent in coating suitability, and exerts an effect on the physical properties of a material to be coated. In addition, it has the effect of promoting the immobilization of coated paints, such as slow release of solvent based on water retention function, suppression of migration of binders, etc., and easy viscosity adjustment based on thickening function. In addition, it is possible to obtain an excellent object to be coated, which is uniform, free of bubbles, uneven coating, uneven color, and has no mud cracks (cracks) in the coating film. Due to the above effects, the water-based coating agent modifier of the present invention has the effect of adjusting the water-based emulsion paint having physical properties suitable for high-speed coating in line-coating of the water-based emulsion paint, and has an effect of improving productivity. Improvement,
Realize high-speed line coating with implants, which is a coating technology trend in the paint industry, from the viewpoints of quality improvement, cost reduction, energy saving, etc., and impart good emulsion paint physical properties, high operability and high coated physical properties. It is suitable for application of a water-based emulsion paint.

────────────────────────────────────────────────── ─── Continued on front page (51) Int.Cl. ⁶ Identification code FI C09K 3/00 103 C09K 3/00 103N D21H 19/44 D21H 1/28 Z

Claims (8)

[Claims] 1. A total of 100 parts by weight of a monomer, (1) 25 to 90 parts by weight of methacrylic acid (salt), and (2) the following general formula:
(I) Wherein R ₁ is H or CH ₃ , R ₂ and R ₃
Is H or an alkyl group having 1 to 2 carbon atoms, R ₄ is an alkylphenyl group, a phenylalkylphenyl group or an alkyl group having 8 to 20 carbon atoms, and n is 3 to 50. )
And 1 to 60 parts by weight of a monomer A represented by the following general formula (J): (Wherein R ₅ is H or CH ₃ , R ₆ and R ₇ are H or one or more selected from the group consisting of alkyl groups having 1 to 2 carbon atoms, and R ₈ is 1 or more carbon atoms.) And B is an alkyl group, and m is 3 to 100.)
1 to 30 parts by weight, and (4) the following general formula (K) (Wherein R ₉ is H or CH ₃ , and R ₁₀ is an alkyl group having 1 to 2 carbon atoms)
A copolymer of 60 parts by weight and other ethylenically unsaturated monomers D0 to 30 parts by weight copolymerizable therewith,
The weight ratio of monomer D / monomer C is less than 0.5, and the viscosity at 25 ° C. of a 2% by weight aqueous solution of a polymer completely neutralized with sodium hydroxide is 50 to 10,000 mPa · s. A modifier for a water-based coating agent, comprising a polymer. 2. The modifier for an aqueous coating agent according to claim 1, wherein the polymer is in the form of an emulsion. 3. The emulsion according to claim 1, wherein said emulsion is an anionic emulsifier such as polyoxyethylene alkyl phenyl ether sulfate, polyoxyethylene alkyl ether sulfate, mono, di, tripolyoxyethylene alkyl phenyl ether phosphate, mono, di, tripolyoxyethylene. One or more selected from the group consisting of an alkyl ether phosphate ester salt and a polyoxyethylene alkylpropenyl phenyl ether sulfate salt and / or as a nonionic emulsifier polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ether and One or more selected from the group consisting of polyoxyethylene alkylpropenyl phenyl ethers is used in an amount of 1 to 25 parts by weight based on 100 parts by weight of the total monomers. The modifier for an aqueous coating agent according to claim 1 or 2, which is subjected to emulsion polymerization. 4. A 2% by weight aqueous solution of a polymer completely neutralized with sodium hydroxide has a viscosity at 25.degree.
A modifier for a paper coating agent comprising the modifier according to any one of claims 1 to 3, which is 00 mPa · s. 5. A paper coating composition containing the modifier according to claim 4 as a main component comprising a pigment and a binder.
A paper coating composition comprising 0.001 to 10 parts by weight per 0 parts by weight. 6. A 2% by weight aqueous solution of a polymer completely neutralized with sodium hydroxide having a viscosity at 25 ° C. of 2,000 to
A modifier for an aqueous emulsion paint and a modifier for an aqueous emulsion, comprising the modifier according to any one of claims 1 to 3 at 10,000 mPa · s. 7. An aqueous emulsion paint containing the modifier according to claim 6 mainly containing a filler and a binder, in an amount of from 0.001 to 1 based on 100 parts by weight of the filler.
A water-based emulsion coating composition, which is added in an amount of 0 parts by weight. 8. An aqueous emulsion composition comprising the modifier according to claim 6 in an amount of 0.05 to 20 parts by weight based on 100 parts by weight of the aqueous emulsion.