JP2022132128A - Water-dispersed resin composition - Google Patents

Abstract

To provide a water-dispersed resin composition having freeze-thaw stability and antifouling property.SOLUTION: A water-dispersed resin composition is provided which is comprised of polymer particles and solvent, and has the following (I) to (II) features. (I) The polymer particles contains more than 20 mass% of a structural unit (X) derived from a fluorine-containing (meth)acrylate monomer (A) in 100 mass% of a monomer, 0.1 mass% or more and 10 mass% or less of a structural unit (Y) derived from a reactive emulsifier (B) in 100 mass% of the monomer, and more than 2 mass% and 30 mass% or less of a structural unit (Z) derived from a (meth)acrylate monomer (C) having a hydroxyl group in 100 mass% of the monomer. (II) Concentration of polymer particles in the water-dispersed resin composition is 2 mass% or more and 50 mass% or less.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a water-dispersible resin composition having high storage stability.

Water-dispersible resin compositions are used in various applications such as cosmetics, detergents, and coating materials. Among them, a water-dispersible resin composition having fluorine-containing polymer particles is used in the chemical industry, etc., because it can form a coating film having excellent antifouling properties and chemical resistance when used as a coating agent, for example. It is used (for example, see Patent Documents 1 and 2). On the other hand, known methods for obtaining a water-dispersible resin composition with high dispersion stability include a method of adding a stability improver and an emulsion polymerization method using an emulsifier that can be copolymerized with a monomer component. (See Patent Document 3, for example).

Japanese Patent No. 6773922 Japanese Patent No. 5569518 JP-A-1-119335

A water-dispersible resin composition is expected to be used in various situations such as high temperature and sub-zero temperature, so high stability is required. However, conventional water-dispersible resin compositions containing fluorine-containing polymer particles cannot be used because, for example, when they are returned to room temperature after being frozen or stored at a high temperature, they continue to solidify, increase in viscosity, and form aggregates. The problem is getting rid of it. Accordingly, the present invention provides a water-dispersed resin composition having storage stability and antifouling properties.

The present invention is a water-dispersed resin composition comprising polymer particles and a solvent, and is a water-dispersed resin composition having characteristics (I) to (II) below.
(I) The structural unit (X) derived from the fluorine-containing (meth)acrylic acid ester monomer (A) in the polymer particles exceeds 20% by mass in 100% by mass of the monomer, and is derived from the reactive emulsifier (B) The structural unit of 0.1 to 10% by mass in 100% by mass of the monomer, and the structural unit (Z) derived from the (meth)acrylic acid ester monomer (C) having a hydroxyl group, 100% by mass of the monomer %, more than 2% by mass and 30% by mass or less.
(II) The concentration of the polymer particles in the water-dispersed resin composition is 2% by mass or more and 50% by mass or less.

Since the water-dispersible resin composition of the present invention does not change in properties after freezing and thawing or after high-temperature storage, it can be transported and stored even in low-temperature or high-temperature environments compared to conventional water-dispersible resin compositions. .

Preferred embodiments of the present invention will be described in detail below. It should be understood that the present invention is not limited only to the embodiments described below, but includes various modifications implemented within the scope of the present invention. The term "-(meth)acrylate" used herein is a concept encompassing both "-acrylate" and "-methacrylate". In addition, "-" in this specification means "above, below".

<Characteristics of water-dispersible resin composition>
The water-dispersible resin composition of the present invention comprises polymer particles and a solvent, and is a dispersion in which the polymer particles are dispersed in the solvent.

The solvent of the water-dispersible resin composition of the present invention may be water, or a mixed solvent comprising water and a solvent other than water. The content of water in the mixed solvent is preferably 50% by mass or more with respect to 100% by mass of the mixed solvent. The content of solvents other than water is preferably 30% by mass or less, more preferably 10% by mass or less, and particularly preferably 5% by mass or less. When the content of the solvent other than water is within the above range, the harmfulness of the water-dispersible resin composition to the human body can be reduced. Solvents other than water include alcohols, ketones, alkanes, and aromatic compounds.

The lower limit of the concentration of the polymer particles in the water-dispersed resin composition is 2% by mass or more, preferably 5% by mass or more, more preferably 10% by mass or more, and particularly preferably 20% by mass or more. When the concentration of the polymer particles is equal to or higher than the lower limit, the drying time can be shortened when the water-dispersed resin composition is applied. The upper limit of the polymer particle concentration is 50% by mass or less, preferably 45% by mass or less, and more preferably 40% by mass or less. When the concentration of the polymer particles is equal to or less than the above upper limit, the fusion of the polymer particles of the water-dispersible resin composition can be suppressed, and the particles are stably dispersed even after freezing and thawing or after high-temperature storage.

When the water-dispersed resin composition of the present invention is frozen in an environment of 0° C. or lower and then returned to room temperature, the solvent melts and returns to a liquid state. The rate of change in particle size of the polymer particles in the water-dispersible resin composition before and after freezing and thawing is 0.8 or more and 1.2 or less. By setting the rate of change in the volume average particle size of the polymer particles after freezing and thawing within the above range, the viscosity does not change before and after freezing and thawing, and the polymer can be used stably even in cold regions.

The freezing method used herein is to put 1 to 100 g of the water-dispersed resin composition in a container and leave it in an environment of 0° C. or lower. The freezing temperature varies depending on the composition of the water-dispersion resin composition, but it may be below the melting point of the water-dispersion resin composition. The time required for freezing also varies depending on the composition, but it may be one hour or more after the solvent of the water-dispersed resin composition has solidified.

The method of melting in this specification is to allow the water-dispersible resin composition frozen by the above method to stand in an environment of 22° C. in a container. The time required for melting varies depending on the composition of the aqueous dispersion resin composition, but may be one hour or more after the solvent of the aqueous dispersion resin composition is liquefied. In addition, when the polymer particles are fused, a film may be formed on the surface of the liquid, or a precipitate may be formed near the bottom.

In addition, the rate of change in the particle size of the polymer particles in the water-dispersed resin composition of the present invention before and after storage in an environment of 80° C. is 0.8 or more and 1.2 or less. is. By setting the rate of change in the volume average particle size of the polymer particles after high-temperature storage within the above range, the viscosity does not change before and after high-temperature storage, and the viscosity is at least 7 even in tropical regions or high-temperature locations exposed to direct sunlight. It can be stably stored and used for days.

The method of storing at 80° C. in this specification is to place 1 to 100 g of the water-dispersed resin composition in a sealed pressure vessel and leave it in a room maintained at 80° C. or in a constant temperature bath.

The volume-average particle diameter of polymer particles is measured using a particle size distribution analyzer based on the principle of dynamic light scattering. Examples of such a particle size distribution analyzer include HORIBA LB-550, SZ-100 series (manufactured by HORIBA, Ltd.), ELS-Z, FPAR-1000 (manufactured by Otsuka Electronics Co., Ltd.) and the like. A small amount of the water-dispersible resin composition is sampled, diluted with water if necessary, placed in a particle size distribution analyzer, allowed to stand still for 5 minutes, and then measured.

The change rate of the volume average particle diameter of the polymer particles before and after freezing and thawing is calculated by (volume average particle diameter after freezing and thawing/volume average particle diameter before freezing and thawing).

Similarly, the change rate of the volume average particle size of polymer particles before and after high temperature storage is calculated by (volume average particle size after high temperature storage/volume average particle size before high temperature storage).

The volume average particle diameter of the polymer particles before freezing and thawing or high-temperature storage is preferably 100 nm or more, more preferably 120 nm or more, and even more preferably 150 nm or more. The volume average particle diameter of the polymer particles is preferably less than 500 nm, more preferably 450 nm or less, and even more preferably 400 nm or less. When the volume average particle size is within the above range, it is easy to obtain a highly concentrated water-dispersed resin composition, and the dispersion stability of the polymer particles is improved, so that the freeze-thaw stability of the water-dispersed resin composition is improved. and high temperature stability are improved. The volume average particle size of the polymer particles can be adjusted by changing the type and composition ratio of the emulsifier.

The particle size distribution (volume average particle size/number average particle size) of the polymer particles is preferably 1.5 or less, more preferably 1.4 or less, still more preferably 1.3 or less, still more preferably 1.2 or less, In addition, it is preferable that it is 1.1 or less. When the particle size distribution is within the above range, for example, when a coating film is formed using the water-dispersible resin composition, a highly uniform coating film can be obtained. The particle size distribution of polymer particles can be adjusted by changing the types of monomers, emulsifiers, composition ratios and polymerization conditions.

The water-dispersed resin composition of the present invention is frozen after freezing at 0 ° C. or lower and then melted and left to stand for 2 hours or more, or the water-dispersed resin composition of the present invention is heated to 80 ° C. The solid content concentration of the dispersion sampled from the upper 30% by mass portion and the lower 30% by mass portion of the water-dispersed resin composition stored under the environment and left to stand for 2 hours or more. The difference is preferably 2% by mass or less. By setting the difference in solid content concentration within the above range, the water-dispersible resin composition can be in a uniform state without stirring, leading to shortening of the process for use.
The solid content concentration of the water-dispersed resin composition can be obtained by measuring the weight of the residue when heated at 140 ° C., for example, a heat drying moisture meter (MS-70, MX-50, manufactured by A & D ) can be calculated from the moisture content obtained using

The dispersion liquid collected from the upper layer 30% by mass portion and the dispersion liquid collected from the lower layer 30% by mass portion are collected after freezing and thawing the water-dispersed resin composition, or after standing at room temperature for 2 hours after storage at high temperature. The former can be obtained by sampling a part of the liquid up to 30% by mass from the liquid surface with a dropper or the like. In the latter, after removing the liquid up to 70% by mass from the liquid surface to the bottom of the water-dispersed resin composition with a dropper or the like, a part of the liquid remaining in the container is collected with a dropper or the like while stirring. can be obtained by

The pH of the water-dispersible resin composition is preferably 5 to 10, more preferably 6 to 9.5. Safety can be improved by setting the pH of the dispersion liquid within such a range.

<Composition of polymer particles>
The polymer particles contained in the water-dispersible resin composition of the present invention are formed of a copolymer consisting of structural units (X), (Y) and (Z). The structural unit (X) is a structural unit derived from the fluorine-containing (meth)acrylic acid ester monomer (A) and represented by the following general formula (1).

(In formula (1), R1 is hydrogen or a methyl group, R2 is a fluorine-containing hydrocarbon group having 1 to 10 carbon atoms, and a represents the degree of polymerization.)
In formula (1), R1 is independently hydrogen or a methyl group. A monomer in which R1 is hydrogen represents an acrylate, and a monomer in which R1 represents a methyl group represents a methacrylate.
R2 is a fluorine-containing hydrocarbon group having 1 to 10 carbon atoms, preferably a fluorine-containing hydrocarbon group having 2 to 10 carbon atoms. The hydrocarbon group may have an unsaturated bond, and may be either a linear hydrocarbon group or a branched hydrocarbon group. At least part of the hydrogen in the hydrocarbon group of R2 is substituted with fluorine. All hydrogen atoms in the hydrocarbon group of R2 may be substituted with fluorine.

R2 is, for example, -CH ₂ CF ₃ , -CH ₂ CF ₂ CF ₂ H, -CH ₂ CF ₂ CF ₃ , -CH ₂ CF ₂ CFHCF ₃ , -CH ₂ (CF ₂ ) ₃ CF2H, -CH ₂ CH _{2 ( CF2} ) _{3CF3 , -CH2 ( CF2} ) _{5CF2H , -CH2CH2 ( CF2} ) _5CF3 , _-CH2CH2 ( _CF2 ) _{7CF3 ,} -CH( CF ₃ ) ₂ , —CH ₂ CCH ₃ (CF ₃ ) ₂ and the like.

The fluorine-containing (meth)acrylic acid ester monomer (A) is a hydrocarbon group (R2) having 1 to 10 carbon atoms and containing fluorine in its ester portion. _CH2 = _CHCOOCH2CF3 (3FA), _{CH2 = CHCOOCH2CF2CF2H ( 4FA} ), _{CH2 = CHCOOCH2CF2CF3} as the fluorine _- containing (meth)acrylate monomer (A) (5FA), _{CH2 = CHCOOCH2CF2CFHCF3} ( _6FA ), _{CH2 = CHCOOCH2} (CF2) _{3CF2H ( 8FA} ) _{, CH2 = CHCOOCH2CH2} (CF2) _3CF3 (9FA) ), _CH2 = _CHCOOCH2 (CF2) _5CF2H (12FA), _{CH2 = CHCOOCH2CH2 (} CF2) _{5CF3 ( 13FA} ), _{CH2 = CHCOOCH2CH2 ( CF2} ) _{7CF 3} (17FA), _CH2 =CHCOOCH( _CF3 ) ₂ (HFIP-A), _CH2 =CHCOOCH2CCH3( _CF3 ) ₂ ( _{6FNP -} A), _{CH2 =} C( _CH3 ) _COOCH2CF3 (3FMA), _CH2 =C( _CH3 )COOCH2CF2CF2H(4FMA), _{CH2 =} C( _CH3 ) _{COOCH2CF2CF3 ( 5FMA} ), _{CH2 =} C( _CH3 ) _COOCH2CF 2CFHCF3(6FMA), _CH2 =C( _CH3 ) _COOCH2 (CF2) _3CF2H ( _8FMA ) _{, CH2 =} C _{( CH3} ) _{COOCH2CH2 (} CF2) _{3CF3 ( 9FMA} ), _CH2 =C( _CH3 )COOCH2(CF2) _5CF2H (12FMA), _{CH2 =} C( _CH3 ) _{COOCH2CH2 (} CF2) _{5CF3 ( 13FMA} ) _{, CH2 =} C( _CH3 ) _{COOCH2CH2(CF2)7CF3(17FMA), CH2=C(CH3)COOCH(CF3)2 ( HFIP - MA ) , CH2 = C} ( _CH3 ) _COOCH2 Compounds such as CCH ₃ (CF ₃ ) ₂ (6FNP-MA) are exemplified.

The lower limit of the structural unit (X) derived from the fluorine-containing (meth)acrylic acid ester monomer (A) is more than 20% by mass, more preferably 22% by mass or more, more preferably 100% by mass of the monomer units. It is 25% by mass or more. The upper limit of the structural unit (X) derived from the fluorine-containing (meth)acrylic acid ester monomer (A) is preferably 60% by mass or less, more preferably 50% by mass or less, in 100% by mass of polymer particle units, It is more preferably 40% by mass or less, still more preferably 35% by mass or less. By setting the structural unit (X) derived from the fluorine-containing (meth)acrylate monomer (A) within the above range, polymer particles having excellent liquid repellency can be obtained.

The structural unit (Y) is a repeating unit derived from the reactive emulsifier (B). The reactive emulsifier (B) is an emulsifier that can chemically bond with the polymer particles. Examples thereof include emulsifiers having functional groups capable of chemically bonding with the side chains of the monomer components. Among them, a compound having a carbon-carbon double bond at its terminal as represented by the following general formula (2) is preferable because of its high reactivity with the monomer component.

(In the formula (2), R1 is hydrogen or a methyl group, R3 is a hydrocarbon group having 1 to 4 carbon atoms and is linear or branched, and R4 is a A hydrocarbon group which may have a linear, branched or cyclic structure, Z is H, _{SO3M (} M is NH4, Na, K) or P=O(OH) _n (n is 1 to 3).)
Examples of reactive emulsifiers include styrenesulfonic acid sodium salts, allylalkylsulfonic acid sodium salts, polyoxyalkylene alkenyl ether sulfate ammonium salts, polyoxyethylene alkylallyl phenyl ether sulfate ammonium salts, polyoxyethylene alkyl allyl phenyl ethers, and the like. . By using a reactive emulsifier, the emulsifier does not separate from the polymer particles even after freezing and thawing the water-dispersed resin composition or after high-temperature storage. fusion can be suppressed.

The lower limit of the structural unit (Y) derived from the reactive emulsifier (B) is 0.1% by mass or more, preferably 1% by mass or more, more preferably 2% by mass or more, particularly preferably 100% by mass of the monomer units. is 2.5% by mass or more. The upper limit of the structural unit (Y) derived from the reactive emulsifier (B) is 10% by mass or less, more preferably 8% by mass or less, still more preferably 5% by mass or less, and still more preferably 100% by mass of the monomer units. It is 3% by mass or less. By containing the structural unit (Y) within the above range, a water-dispersible resin composition having excellent freeze-thaw stability or high-temperature stability can be obtained.

The structural unit (Z) is a structural unit derived from the (meth)acrylic acid ester monomer (C) having a hydroxyl group, and is represented by the following general formula (3).

(In formula (3), R1 is hydrogen or a methyl group, R5 is a hydrocarbon group having 1 to 10 carbon atoms containing a hydroxyl group, and b represents the degree of polymerization.)
In formula (3), R1 is independently hydrogen or a methyl group. A monomer in which R1 is hydrogen represents an acrylate, and a monomer in which R1 represents a methyl group represents a methacrylate.
R5 is a hydrocarbon group of 1 to 10 carbon atoms containing a hydroxyl group, preferably a hydrocarbon group of 2 to 6 carbon atoms containing a hydroxyl group. The hydrocarbon group may have an unsaturated bond. Further, it may be either a linear hydrocarbon group or a branched hydrocarbon group. At least one hydrogen in the hydrocarbon group of R5 is substituted with a hydroxyl group. Examples of R5 include hydroxymethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl, hydroxypentyl, hydroxyhexyl, hydroxyheptyl, hydroxyoctyl, and the like.
Examples of the (meth)acrylic acid ester monomer (C) having a hydroxyl group include hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, ) acrylate, 4-hydroxybutyl (meth)acrylate, 5-hydroxypentyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 7-hydroxyheptyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, etc. can be mentioned. 2-Hydroxyethyl acrylate, 4-hydroxybutyl acrylate and 2-hydroxypropyl acrylate are particularly preferred.
The structural unit (Z) derived from the (meth)acrylic acid ester monomer (C) having a hydroxyl group is more than 2% by mass and not more than 30% in 100% by mass of the monomer units. The lower limit of the structural unit (Z) derived from the (meth)acrylic acid ester monomer (C) having a hydroxyl group is preferably 2.5% by mass or more, more preferably 3% by mass in 100% by mass of the monomer units. More preferably, it is 5% by mass or more, and more preferably 10% by mass or more. The upper limit of the structural unit (Z) derived from the (meth)acrylic acid ester monomer (C) having a hydroxyl group is preferably 20% by mass or less, more preferably 15% by mass or less in 100% by mass of the monomer units. be. By containing the structural unit (Z) derived from the (meth)acrylic acid ester monomer (C) having a hydroxyl group in the above range, the dispersion stability is improved, so that the freezing stability or high temperature stability is excellent. A water-dispersible resin composition can be obtained.

Further, the polymer particles in the water-dispersible resin composition of the present invention further contain more than 2% by mass and 10% by mass or less of structural units derived from the monomer (D) having two or more reactive groups per molecule. It is preferable to contain. As the monomer (D) having two or more reactive groups per molecule, a monomer capable of forming a crosslinked structure when polymerized can be used. Examples of the monomer (D) having two or more reactive groups per molecule include polyalkylene glycol dimethacrylate and urethane acrylate. By containing the monomer (D) having two or more reactive groups per molecule within the above range, polymer particles having excellent flexibility can be obtained.

The copolymer forming the polymer particles can contain a repeating unit derived from the radically polymerizable compound as a structural unit other than the structural unit (X) and the structural unit (Y). Examples of radically polymerizable compounds that can be other structural units include (meth)acrylic acid esters and vinyl compounds other than the (meth)acrylic acid ester monomers (A) to (B) described above. Examples of radical polymerizable compounds include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, ( Sec-butyl meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, neopentyl (meth)acrylate, isoamyl (meth)acrylate, hexyl (meth)acrylate, (meth)acrylate 2-ethylhexyl acrylate, lauryl (meth)acrylate, dodecyl (meth)acrylate, 2-dimethylaminoethyl (meth)acrylate, 2-diethylaminoethyl (meth)acrylate, 2-(meth)acrylate -dipropylaminoethyl, 2-diphenylaminoethyl (meth)acrylate, 3-(N,N-dimethylamino)propyl (meth)acrylate, benzyl (meth)acrylate, cyclohexyl (meth)acrylate, t-butyl Cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, isobornyl (meth)acrylate, N-(meth)acryloylphthalimide, styrene, vinyl chloride, vinylidene chloride, vinyl fluoride, fluorine vinylidene chloride, N-vinylpyrrolidone, vinylpyridine, vinyl acetate and the like. Among them, methyl (meth)acrylate and styrene are preferred.

The polymer particles contained in the water-dispersible resin composition of the present invention are preferably copolymers, preferably amorphous polymers having a glass transition temperature. Since the polymer particles are amorphous polymers, for example, when the water-dispersible resin composition is used as a paint, the adhesion to the substrate is improved.

<Method for producing water-dispersible resin composition>
The water-dispersible resin composition of the present invention can be obtained by copolymerizing a monomer mixture in an aqueous medium. A preferable example of the method for polymerizing the monomer components in an aqueous medium is emulsion polymerization.

Conditions for emulsion polymerization of the monomer mixture are not particularly limited. The reaction may be carried out for about 30 hours. In addition, a chain transfer agent, a chelating agent, a pH adjuster, a solvent, etc. may be added as necessary.

As the emulsifier used in the emulsion polymerization, the above-mentioned reactive emulsifier is used, but it can also be used in combination with a non-reactive emulsifier. Examples of non-reactive emulsifiers include anionic surfactants, cationic surfactants, and nonionic surfactants, excluding the reactive emulsifiers described above. Examples of anionic surfactants include sodium alkyl sulfate, sodium alkylbenzene sulfonate, sodium dialkyl succinate sulfonate, sodium alkyldiphenyl ether disulfonate, sodium polyoxyethylene alkyl ether sulfate, and polyoxyethylene. Alkylphenyl ether sulfate sodium salt and the like can be mentioned. Among these, sodium lauryl sulfate, sodium dodecylbenzenesulfonate, sodium polyoxyethylene alkyl ether sulfate, sodium lauryl sulfate and the like can be mentioned. Examples of nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkylaryl ethers, polyoxyethylene fatty acid esters, polyoxyethylene sorbitan fatty acid esters, and the like. Polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether and the like are generally used.

As the polymerization initiator, use a water-soluble polymerization initiator such as sodium persulfate, potassium persulfate, ammonium persulfate, hydrogen peroxide, or a redox polymerization initiator that combines these water-soluble polymerization initiators with a reducing agent. can do. Among these, potassium persulfate and ammonium persulfate are preferred. Examples of reducing agents include sodium pyrobisulfite, sodium hydrogensulfite, sodium sulfite, sodium thiosulfate, L-ascorbic acid or salts thereof, sodium formaldehyde sulfoxylate, ferrous sulfate, glucose and the like. Among these, L-ascorbic acid or salts thereof are preferred.

An oil-soluble polymerization initiator can also be used by dissolving it in a monomer or solvent. Examples of the oil-soluble polymerization initiator include 2,2'-azobisisobutyronitrile, 2,2'-azobis-(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis -2,4-dimethylvaleronitrile, 1,1'-azobiscyclohexane-1-carbonitrile, 2,2'-azobisisovaleronitrile, 2,2'-azobisisocapronitrile, 2,2' -azobis(phenylisobutyronitrile), benzoyl peroxide, di-t-butyl peroxide, dilauroyl peroxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, paramenthane hydroperoxide, t-butyl hydroperoxide , 3,5,5-trimethylhexanol peroxide, t-butylperoxy (2-ethylhexanoate) and the like. Among these, 2,2′-azobisisobutyronitrile, benzoyl peroxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, paramenthane hydroperoxide, t-butyl hydroperoxide, 3,5,5- Trimethylhexanol peroxide, t-butylperoxy (2-ethylhexanoate) are preferred.

The amount of the polymerization initiator used is preferably about 0.1 to 3 parts by mass per 100 parts by mass of the monomer mixture.

Examples of chain transfer agents include halogenated hydrocarbons (eg, carbon tetrachloride, chloroform, bromoform, etc.), mercaptans (eg, n-dodecylmercaptan, t-dodecylmercaptan, n-octylmercaptan, n-hexadecylmercaptan, etc.), xanthogen. (e.g., dimethylxanthogen disulfide, diethylxanthogen disulfide, diisopropylxanthogen disulfide, etc.), terpenes (e.g., dipentene, terpinolene, etc.), thiuram sulfides (e.g., tetramethylthiuram monosulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, dipentamethyl thiuram disulfide, etc.).

The amount of the chain transfer agent used is preferably about 0 to 10 parts by weight per 100 parts by weight of the monomer mixture.

Examples of pH adjusters include sodium carbonate, potassium carbonate, sodium hydrogen carbonate, and ammonia. Further, the amount of the pH adjuster used is preferably about 0 to 3 parts by mass per 100 parts by mass of the monomer mixture.

When emulsion-polymerizing the monomer mixture in an aqueous medium, the monomer mixture can be added by various methods. As the method of addition, a method of adding the entire amount of the monomer mixture at once, a method of charging a part of the monomer mixture and reacting it, and then charging the remaining monomer mixture continuously or dividedly, a method of reacting After charging a part of the obtained particles, the remaining monomer mixture is continuously or dividedly charged, and the total amount of the monomer mixture is continuously or sequentially divided and charged. A method of charging a part of the reacted particles and then charging the remaining monomer mixture continuously or dividedly, or charging a part of the reacted particles and then charging the remaining monomer mixture continuously or dividedly It is preferable to use the

<Application of water-dispersible resin composition>
The water-dispersible resin composition of the present invention can be applied to materials such as wood, metals, ceramics, carbon materials, glass and plastics to form a coating film, thereby modifying surface properties.

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited by these examples. In the following description, "%" and "parts" represent "% by mass" and "parts by mass." The measurement methods used in this example are shown below.

(1) Volume Average Particle Size and Particle Size Distribution The volume average particle size of polymer particles was measured using a particle size distribution analyzer (ELS-Z, manufactured by Otsuka Electronics Co., Ltd.). A particle size distribution was obtained from the obtained values.

(2) Concentration of Polymer Particles According to JIS K5601-1-2:2008, 1.0 g of the water-dispersible resin composition was heated at 140° C., the residue was measured, and the concentration of the polymer particles was calculated.

(3) pH
The pH of the water-dispersible resin composition was measured.

(4) Gel fraction Assuming that the gel fraction (=crosslinked particles) was solid-liquid separated with a filter before analyzing the polymer particles by gel permeation chromatography (GPC, manufactured by Waters), from the area intensity measured by GPC , the gel fraction was calculated from the following formula.
Gel fraction = (XY)/X
X: areal strength of polymer particles not containing a monomer (D) having two or more reactive groups per molecule (≒total amount)
Y: Area intensity of GPC of filtrate of polymer particles containing monomer (D) having two or more reactive groups per molecule (≈ dissolved content)
XY: Area intensity corresponding to filtration residue containing monomer (D) having two or more reactive groups per molecule ≈ (insoluble matter, gel content)
In the examples, the monomer (D) having two or more reactive groups per molecule was polyalkylene glycol dimethacrylate (Blemmer (registered trademark) PDE-600 (manufactured by NOF Corporation). .

(5) Liquid Repellency A dispersion liquid was prepared by diluting the water-dispersed resin composition of the present invention with water so that the solid content concentration was 10% by mass. This dispersion was applied onto a PET substrate with a bar coater (#3) and dried at 60° C. for 10 minutes to form a coating film layer (particle film composed of polymer particles). Conduct contact angle measurement using water as a solvent, "excellent" if the contact angle is 90 ° or more, "good" if the contact angle is 70 ° or more and less than 90 °, and the contact angle is 50 ° or more and less than 70 ° If the contact angle is less than 50°, it is evaluated as “slightly inferior”, and if the contact angle is greater than 70°, it is determined that the liquid repellency is good. The "liquid repellency" described in Table 2 is the value of the contact angle.

(6) Change rate of volume average particle size of water-dispersed resin composition before and after freezing and thawing 10 g of the water-dispersed resin composition was placed in a glass bottle and left to stand for 24 hours in an environment of -13 ° C. to freeze. . After that, it was melted by standing in an environment of 22° C. for 2 hours. After the melted water-dispersible resin composition was shaken by hand, a small amount was immediately sampled with a dropper to measure the volume average particle size and particle size distribution. "Good" if the volume average particle size change rate is 0.8 or more and 1.2 or less, "Slightly inferior" if 0.5 or more and less than 0.8, or more than 1.2 and 1.5 or less If it is less than 0.5 or more than 1.5, it is evaluated as "poor", and if the change rate of the volume average particle size is 0.8 or more and 1.2 or less, it is judged that the freeze-thaw stability is good.

(7) Rate of Change in Volume Average Particle Size of Water-Dispersed Resin Composition After High-Temperature Storage 10 g of the water-dispersed resin composition was placed in a glass bottle and allowed to stand in an environment of 80° C. for 7 days. After that, it was allowed to stand in an environment of 22° C. for 2 hours. After the melted water-dispersible resin composition was shaken by hand, a small amount was immediately sampled with a dropper to measure the volume average particle size and particle size distribution. "Good" if the volume average particle size change rate is 0.8 or more and 1.2 or less, "Slightly inferior" if 0.5 or more and less than 0.8, or more than 1.2 and 1.5 or less If it is less than 0.5 or more than 1.5, it is evaluated as "poor", and if the change rate of the volume average particle size is 0.8 or more and 1.2 or less, it is judged that the high temperature stability is good.

(8) The difference in solid content concentration between the upper 30% by mass and the lower 30% by mass before and after freezing and thawing of the water-dispersed resin composition. Put 10 g of the water-dispersed resin composition in a glass bottle and place it in an environment of -13 ° C. for 24 hours. It was frozen by standing still. After that, it was melted by standing at 22° C. for 2 hours. Then, the mixture was shaken by hand and allowed to stand at 22° C. for 2 hours. Then, 1.0 g of the dispersion liquid was sampled from the upper portion of 30% by weight, and the concentration of polymer particles was measured. Thereafter, 6.0 g of the dispersion liquid was removed from the liquid surface with a dropper, and the remaining 3.0 g of the dispersion liquid was shaken by hand, and 1.0 g was immediately sampled to measure the concentration of the polymer particles. If the difference in solid content concentration is 2% by mass or less, it is evaluated as "good", if it is more than 2% by mass and 4% by mass or less, it is evaluated as "slightly inferior". If the difference is 2% by mass or less, the freeze-thaw stability is determined to be good.

(9) The difference in solid content concentration between 30% by mass and the lower 30% by mass after high-temperature storage of the water-dispersed resin composition Put 10 g of the water-dispersed resin composition in a glass bottle and leave it for 7 days in an environment of 80 ° C. did. After that, it was allowed to stand in an environment of 22° C. for 2 hours. Then, the mixture was shaken by hand and allowed to stand at 22° C. for 2 hours. Then, 1.0 g of the dispersion liquid was sampled from the upper portion of 30% by weight, and the concentration of polymer particles was measured. Thereafter, 6.0 g of the dispersion liquid was removed from the liquid surface with a dropper, and the remaining 3.0 g of the dispersion liquid was shaken by hand, and 1.0 g was immediately sampled to measure the concentration of the polymer particles. If the difference in solid content concentration is 2% by mass or less, it is evaluated as "good", if it is more than 2% by mass and 4% by mass or less, it is evaluated as "slightly inferior". is 2% by mass or less, it is determined that the high-temperature stability is good.

Example 1
90 parts by mass of ion-exchanged water and 0.8 parts by mass of ADEKA LISORB SR-1025 (25% aqueous solution of ether sulfate type anionic surfactant, manufactured by ADEKA CORPORATION) as a reactive emulsifier having a terminal double bond in the molecule are added to a reactor. and started stirring. To this, 0.4 parts by mass of 2,2′-azobis(2-(2-imidazolin-2-yl)propane) (manufactured by Wako Pure Chemical Industries, Ltd.) was added under a nitrogen atmosphere, and 2,2,2 - 29 parts by weight of trifluoroethyl methacrylate (3FMA), 59 parts by weight of cyclohexyl acrylate (CHA), 3 parts by weight of 4-hydroxybutyl acrylate (4HBA), polyalkylene glycol dimethacrylate (Blemmer (registered trademark) PDE-600 (NOF) A monomer mixture consisting of 6.6 parts by mass of Adeka Resorb SR-1025 (manufactured by ADEKA CORPORATION) and 49 parts by mass of ion-exchanged water was continuously stirred at 60° C. for 2 hours. After completion of the dropping, the polymerization treatment was carried out for 3 hours. The water-dispersible resin composition obtained by filtering through a nylon mesh (77 μm opening) was as shown in Table 1. The composition ratio of the monomers shown in Table 1 is the ratio of each component to the total amount of the monomer components.

In addition, the abbreviation of each component in Table 1 has the following meaning, respectively.
3FMA: 2,2,2-trifluoroethyl methacrylate (in formula (1) above, R ¹ : —CH ₃ , R ² : —CH ₂ CF ₃ );
4HBA: 4-hydroxybutyl acrylate CHA: cyclohexyl acrylate MMA: methyl (meth)acrylate BA: n-butyl (meth)acrylate CHMA: cyclohexyl methacrylate IBOMA: isobornyl methacrylate.

Example 2
A water-dispersed resin composition was obtained in the same manner as in Example 1, except that the composition ratio of the monomer mixture was changed to the composition shown in Table 1. The resulting water-dispersible resin composition was as shown in Table 2.

Example 3
The amount of ion-exchanged water was changed to 230 parts, and other radically polymerizable compounds were replaced with methyl (meth)acrylate (MMA) (Wako Pure Chemical Industries, Ltd.) and n-butyl (meth)acrylate (BA ) (Wako Pure Chemical Industries, Ltd.), and the composition ratio of the monomer mixture was changed to the composition shown in Table 1, in the same manner as in Example 1 to obtain a water-dispersed resin composition. rice field. The resulting water-dispersible resin composition was as shown in Table 2.

Example 4
A water-dispersed resin composition was obtained in the same manner as in Example 1, except that the composition ratio of the monomer mixture was changed to the composition shown in Table 1. The resulting water-dispersible resin composition was as shown in Table 2.

Example 5
A water-dispersible resin composition obtained in the same manner as in Example 1 was diluted 10-fold with deionized water. The resulting water-dispersible resin composition was as shown in Table 2.

Comparative example 1
300 parts of ion-exchanged water and 0.2 parts of sodium lauryl sulfate were charged into a reactor, and stirring was started. To this was added 0.5 parts of ammonium persulfate at 80° C. under a nitrogen atmosphere, followed by 50 parts of 2,2,2-trifluoroethyl methacrylate (3FMA), 24 parts of cyclohexyl methacrylate (CHMA), and 24 parts of cyclohexyl acrylate (CHA). , 2 parts of 4-hydroxybutyl acrylate (4HBA), 2 parts of sodium lauryl sulfate, and 50 parts of ion-exchanged water were continuously added dropwise over 4 hours, and polymerization was performed for 3 hours after completion of the dropwise addition. rice field. The pH was adjusted to about 8 with aqueous ammonia. The polymer particles obtained by filtration through a nylon mesh (77 μm mesh size) were as shown in Table 2.

Comparative example 2
A water-dispersed resin composition was obtained in the same manner as in Comparative Example 1, except that the composition ratio of the monomer mixture was changed to the composition shown in Table 1. The resulting water-dispersible resin composition was as shown in Table 2.

Since the water-dispersible resin composition of the present invention is excellent in freeze-thaw stability and high-temperature stability, it can be transported and stored even in high-temperature or low-temperature environments. In addition, when the water-dispersible resin composition of the present invention is used as a coating material, a coating film having excellent antifouling properties can be obtained, so it can be used as a coating agent for building materials, clothing, structural materials, electronic parts, and the like. I can expect it.

Claims (5)

A water-dispersible resin composition comprising polymer particles and a solvent, and characterized by (I) to (II) below.
(I) The structural unit (X) derived from the fluorine-containing (meth)acrylic acid ester monomer (A) in the polymer particles exceeds 20% by mass in 100% by mass of the monomer, and is derived from the reactive emulsifier (B) The structural unit (Y) of 0.1% by mass or more and 10% by mass or less in 100% by mass of the monomer, and the structural unit (Z) derived from the (meth) acrylic ester monomer (C) having a hydroxyl group, It contains more than 2% by mass and 30% by mass or less in 100% by mass of the monomer.
(II) The concentration of the polymer particles in the water-dispersible resin composition is 2% by mass or more and 50% by mass or less. 2. The water-dispersible resin composition according to claim 1, wherein the reactive emulsifier (B) has a terminal double bond in its molecule. 3. The water-dispersible resin composition according to claim 1, wherein the polymer particles further contain a structural unit derived from a monomer (D) having two or more reactive groups per molecule. It is a water-dispersed resin composition comprising polymer particles and a solvent, and when the polymer particles are frozen at 0 ° C. or lower and then melted, and / or when the polymer particles are allowed to stand at 80 ° C. for 7 days. A water-dispersed resin composition having a volume average particle diameter change rate of 0.8 or more and 1.2 or less. 30% by mass of the upper layer of the water-dispersed resin composition when the water-dispersed resin composition having a polymer particle concentration of 2% by mass or more and 50% by mass or less is frozen at 0 ° C. or less and then melted. 5. The water-dispersible resin composition according to claim 4, wherein the difference between the solid content concentration of and the solid content concentration of the lower layer 30 mass % portion is 2 mass % or less.