JP2006249183A - Aqueous resin dispersion - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aqueous resin dispersion which forms a coated film excellent in weather resistance and blocking resistance. <P>SOLUTION: The aqueous resin dispersion is obtained by polymerizing not less than two kinds of monomers having different glass transition temperatures (Tg). The aqueous resin dispersion comprises a high Tg component with a glass transition temperature (Tg) of &ge;50&deg;C, and a low Tg component with a glass transition temperature (Tg) of &le;40&deg;C. The overall glass transition temperature of the aqueous resin dispersion is &ge;40&deg;C. <P>COPYRIGHT: (C)2006,JPO&amp;NCIPI

Description

  The present invention relates to an aqueous resin dispersion used for paints and coatings having excellent weather resistance and blocking resistance. Here, blocking refers to various coated objects such as metals, wood, paper, plastics, inorganic building materials, etc., which are coated with water-based resin dispersions, and the coatings adhere to each other. Means the phenomenon.

  In recent years, water-based paints are increasingly used from the viewpoint of environmental problems, and water-based resin dispersions are widely used for paints and coating applications. However, since the film formation (film formation) of the aqueous resin dispersion is performed by fusing polymer particles, those having a high glass transition temperature (Tg) of the resin are formed using a large amount of a film forming aid. There must be. Then, when the coating film is insufficiently dried, there is a problem that the blocking resistance is deteriorated due to the influence of the remaining film forming aid. In addition, although the resin having a low glass transition temperature (Tg) of the aqueous resin dispersion can be formed at around room temperature, the formed coating film remains sticky after drying and has poor blocking resistance. There is a problem. If the blocking resistance is poor, the coating will be damaged or the substrate will be destroyed, and the purpose of the coating (substrate), which is the original purpose of coating, will not be achieved. Aqueous resin dispersions used for coating and the like require blocking resistance. Accordingly, various studies have been conducted on aqueous resin dispersions having a high Tg and a low film-forming temperature (MFT) that requires a small amount of film-forming aid. As these techniques, the aqueous resin dispersion exhibits the above-mentioned features by using a monomer that becomes a high Tg resin component in the core part of the aqueous resin dispersion and a monomer that becomes a low Tg resin component in the shell part. The body is disclosed in Patent Document 1 and Patent Document 2. However, in Patent Document 1, since the high Tg resin component is as small as 10 to 35% by mass, a certain blocking resistance can be obtained, but there is a problem that the blocking resistance is insufficient under severe conditions. Moreover, in patent document 2, there existed a problem in a weather resistance, and also blocking resistance was also inadequate under severe conditions.

JP 2003-226793 A JP 2001-181557 A

  This invention is providing the aqueous resin dispersion which can form the coating film excellent in the weather resistance and blocking resistance.

As a result of intensive studies to solve the above problems, the present inventors have completed the present invention.
That is, the first of the present invention is an aqueous resin dispersion polymerized using two or more kinds of polymerizable monomers having different glass transition temperatures (Tg), and the aqueous resin dispersion has a glass transition temperature ( Tg) is composed of a high Tg resin component having a temperature of 50 ° C. or more and a low Tg resin component having a glass transition temperature (Tg) of 40 ° C. or less, and the glass transition temperature (Tg) of the entire aqueous resin dispersion is 40 ° C. or more. This is an aqueous resin dispersion characterized by the above.
According to a second aspect of the invention, the mass ratio of the high Tg resin component and the low Tg resin component is high Tg resin component / low Tg resin component (mass ratio) = 35/65 to 70/30. 1. The aqueous resin dispersion according to 1.

The third aspect of the invention is that the alkoxysilane group-containing polymerizable monomer (A), the cycloalkyl group-containing polymerizable monomer (B), and the carboxyl group-containing polymerizable monomer are added to the high Tg resin component of the aqueous resin dispersion. The aqueous resin dispersion according to the first or second aspect of the invention, comprising (C).
According to a fourth aspect of the invention, the amount of the cycloalkyl group-containing polymerizable monomer (B) of the high Tg resin component is 10 to 80% by mass of the total monomer of the high Tg resin component. It is the aqueous resin dispersion in any one of 1-3.
The fifth aspect of the invention includes a carboxyl group-containing polymerizable monomer in the high Tg resin component and the low Tg resin component of the aqueous resin dispersion, and the carboxyl group-containing polymerizable monomer / low Tg resin component of the high Tg resin component. The carboxyl group-containing polymerizable monomer (mass ratio) = 10/90 to 70/30. The aqueous resin dispersion according to any one of the first to fourth aspects of the invention.

A sixth aspect of the invention is any one of the first to fifth aspects of the invention, wherein the high Tg resin component and / or the low Tg resin component of the aqueous resin dispersion contains a hydroxyl group-containing polymerizable monomer (D). The aqueous resin dispersion described.
A seventh aspect of the invention is the aqueous resin dispersion according to any one of the first to sixth aspects of the invention, which also contains a Si-containing compound (E) represented by the following formula (1).
_{^{(R 1) n -Si- (R}} 2) 4-n (1)
(In the formula, n is an integer of 0 to 3, and R ¹ is hydrogen, an aliphatic hydrocarbon group having ^{1 to} 16 carbon atoms, an aryl group having 5 to 10 carbon atoms, a cycloalkyl group having 5 to 6 carbon atoms, vinyl. group, also alkyl acrylate group having 1 to 10 carbon atoms or .n number of R ¹ selected from methacrylic acid alkyl group having 1 to 10 carbon atoms, are the same and good .R ² be different carbon atoms (It is selected from 1 to 8 alkoxy groups, acetoxy groups, and hydroxyl groups. 4-n R ² groups may be the same or different.)

An eighth aspect of the invention is characterized in that the high Tg resin component has a structure composed of a central portion (core) of the aqueous resin dispersion particles, and the low Tg resin component comprises an outer portion (shell) of the aqueous resin dispersion particles. It is the aqueous resin dispersion in any one of 1-7.
A ninth aspect of the invention is the aqueous resin dispersion according to any one of the first to eighth aspects of the invention, which is obtained by emulsion polymerization in two or more steps.
A tenth aspect of the invention is the aqueous resin dispersion according to any one of the first to ninth aspects, wherein the pH during the emulsion polymerization is 4 or less.
An eleventh aspect of the invention is a paint comprising the aqueous resin dispersion according to any one of the first to tenth aspects of the invention, wherein the coating film is excellent in blocking resistance.

  If the aqueous resin dispersion of this invention is used, the coating film which is excellent in a weather resistance and blocking resistance can be formed.

Hereinafter, the present invention will be described in detail.
Aqueous resin dispersion The aqueous resin dispersion in the present invention is an aqueous resin dispersion formed by integrating a plurality of polymerizable monomer components having different glass transition temperatures (Tg) in the course of polymerization, and has a high Tg. The Tg of the resin component (hereinafter sometimes simply referred to as “high Tg component”) is 50 ° C. or higher, the Tg of the low Tg resin component (hereinafter also simply referred to as “low Tg component”) is 40 ° C. or lower, and the total resin Tg is An acrylic polymer composed of 40 ° C. or higher. In particular, the high Tg component is in the core part and the low Tg component is in the shell part due to blocking resistance and film formability. Preferably there is. In the present invention, the Tg (K: absolute temperature) of the aqueous resin dispersion is calculated using the following FOX equation.
1 / Tg = W ₁ / Tg ₁ + W ₂ / Tg ₂ +... + W _i / Tg _i +... W _n / Tg _n [The FOX formula constitutes a polymer composed of n types of monomers. The glass transition temperature of the homopolymer of each monomer is Tg _i (K), the mass fraction of each monomer is W _i, and (W ₁ + W ₂ + ... + W _i + ... + W _n = 1) ]

Furthermore, in the present invention, it is important that the ratio between the high Tg component and the low Tg component is high Tg component / low Tg component (mass ratio) = 35/65 to 70/30. Preferably, high Tg component / low Tg component (mass ratio) = 40/60 to 60/40. When the ratio of the high Tg component is less than the above ratio, the blocking resistance is deteriorated. On the other hand, if the ratio of the high Tg component is larger than the above range, the MFT increases and the frost damage resistance (where frost damage is a phenomenon that causes deterioration such as surface deterioration, strength reduction, cracking, etc. due to the action of freezing or freezing and thawing). Will be damaged.
SPM (scanning probe microscope) can be used as a method for confirming that the high Tg component is in the core portion and the low Tg component is in the shell portion.

Alkoxysilane group-containing polymerizable monomer (A)
Examples of the alkoxysilane group-containing polymerizable monomer (A) used in the present invention include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, vinylmethyldimethoxysilane, γ-methacryloxypropyl. Trimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-acryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ -Methacryloxypropylmethyldiethoxysilane or the like, and one or more selected from these groups are used. Particularly preferred are γ-methacryloxypropyltrimethoxysilane and γ-methacryloxypropyltriethoxysilane. Furthermore, it is important that the amount of the alkoxysilane group-containing polymerizable monomer (A) of the high Tg resin component is 0.1 to 30% by mass in the total monomers of the high Tg resin component. In particular, 0.4 to 20% by mass is preferable from the viewpoints of polymerization stability and blocking resistance.

Cycloalkyl group-containing polymerizable monomer (B)
Examples of the cycloalkyl group-containing polymerizable monomer (B) used in the present invention include cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, tertiary butylcyclohexyl (meth) acrylate, and the like. 1 or 2 or more selected from is used. Particularly preferred is cyclohexyl (meth) acrylate. Furthermore, it is important that the amount of the cycloalkyl group-containing polymerizable monomer (B) of the high Tg resin component is 10 to 80% by mass in the total monomers of the high Tg resin component. 20-80 mass% is especially preferable from the viewpoint of polymerization stability and weather resistance.

Carboxyl group-containing polymerizable monomer (C)
Examples of the carboxyl group-containing polymerizable monomer (C) used in the present invention include acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, maleic anhydride and the like. Or two or more are used. Acrylic acid and methacrylic acid are particularly preferred. Further, in terms of polymerization stability, the high Tg component and the low Tg component contain a carboxyl group-containing polymerizable monomer, and the ratio of the high Tg component and the low Tg component is high Tg component / low Tg component (mass ratio) = 10 / 90- It is important that it is 70/30.

Hydroxyl-containing polymerizable monomer (D)
Examples of the hydroxyl group-containing polymerizable monomer (D) used in the present invention include 2-hydroxyethyl (meth) acrylate, 4-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, caprolactone-modified (meta ) Acrylate, polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, etc., and one or more selected from these groups are used. Particularly preferred is 2-hydroxyethyl (meth) acrylate. Since the color developability is improved by using one or more of these, it is preferably used according to the purpose of the paint.
Si-containing compound (E)

The Si-containing compound (E) used in the present invention is represented by the following formula (1).
_{^{(R 1) n -Si- (R}} 2) 4-n (1)
(In the formula, n is an integer of 0 to 3, R ¹ is hydrogen, an aliphatic hydrocarbon group having ^{1 to} 16 carbon atoms, an aryl group having 5 to 10 carbon atoms, a cycloalkyl group having 5 to 6 carbon atoms, vinyl. One or more groups selected from a group, an alkyl acrylate group having 1 to 10 carbon atoms, or an alkyl methacrylate group having 1 to 10 carbon atoms, and n R ¹ groups may be the same or different. R ² is one or more groups selected from an alkoxy group having 1 to 8 carbon atoms, an acetoxy group, and a hydroxyl group, and 4-n R ² may be the same or different.
The Si-containing compound (E) preferably contains at least one of silane (I) in which n = 0 in formula (1) and / or silane (II) in which n = 1, and has good water In order to obtain the polymerization stability of the dispersion, n = 1 silane (II) is more preferable.

R ² of silane (I) is preferably independently a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a methoxyethoxy group or a hydroxyl group. Preferable specific examples of silane (I) include tetramethoxysilane and tetraethoxysilane.
R ¹ of silane (II) is preferably a methyl group or a phenyl group, and R ² is independently preferably a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a methoxyethoxy group or a hydroxyl group. Preferable specific examples of silane (II) include methyltrimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, phenyltriethoxysilane, isobutyltrimethoxysilane and the like.

Further, when flexibility is required, the Si-containing compound (E) is at least one selected from the group consisting of cyclic silane and silane (III) obtained by setting n = 2 in the formula (1). It is preferable to use it. This is because, by using at least one selected from the group consisting of silane (II), cyclic silane and silane (III), the crosslinking density of the silicone polymer formed by the Si-containing compound (E) is reduced, This is because the structure of the coalescence can be prevented from becoming complicated, and thereby, flexibility can be imparted to the coating film provided from the aqueous resin dispersion, particularly when used in combination with silane (II). preferable.
Specific examples of the cyclic silane include octamethylcyclotetrasiloxane, octaphenylcyclosiloxane, hexamethylcyclotrisiloxane, decamethylcyclopentasiloxane, and the like.

Specific examples of silane (III) include dimethyldimethoxysilane, diphenyldimethoxysilane, dimethyldiethoxysilane, diphenyldiethoxysilane, and methylphenylsilane.
Furthermore, the Si-containing compound (E) includes at least one selected from the group consisting of a linear siloxane having a hydrolyzable group, an alkoxysilane oligomer, and silane (IV) obtained by setting n = 3 in the formula (1). May be included.
Specific examples of silane (IV) include triphenylethoxysilane and trimethylmethoxysilane.

（式中、Ｒ¹ は水素、炭素数１〜１６の脂肪族炭化水素基、炭素数５〜１０のアリール基、炭素数５〜６のシクロアルキル基、炭素数１〜１０のアクリル酸アルキル基又は炭素数１〜１０のメタクリル酸アルキル基から選ばれ、各Ｒ² はそれぞれ、独立して炭素数１〜８のアルコキシ基、アセトキシ基、水酸基、エポキシ基、アルキレンオキサイド基又はポリアルキレンオキサイド基から選ばれ、ｍは１〜９９９の正の整数を表す。） Examples of the linear siloxane having a hydrolyzable group include compounds represented by the following general formulas (1), (2), and (3).

Wherein R ¹ is hydrogen, an aliphatic hydrocarbon group having ^{1 to} 16 carbon atoms, an aryl group having 5 to 10 carbon atoms, a cycloalkyl group having 5 to 6 carbon atoms, and an alkyl acrylate group having 1 to 10 carbon atoms. Or an alkyl group having 1 to 10 carbon atoms, and each R ² is independently selected from an alkoxy group having 1 to 8 carbon atoms, an acetoxy group, a hydroxyl group, an epoxy group, an alkylene oxide group, or a polyalkylene oxide group. And m represents a positive integer of 1 to 999.)

In silane (III) or silane (IV), R ¹ is particularly preferably a methyl group or a phenyl group, and R ² is particularly preferably a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a methoxyethoxy group or a hydroxyl group.
The Si-containing compound (E) is added to at least one selected from the group consisting of silane (II) and cyclic silane, silane (III), linear siloxane, alkoxysilane oligomer, silane (IV), and chlorosilane such as methyl It may include chlorosilane, methyldichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, diphenylchlorosilane.

With the Si-containing compound (E) used in the present invention, the gloss retention in a long-term exposure of the coating film obtained from the aqueous resin dispersion of the present invention can be improved. The presence of the above-mentioned silane condensate can be known by ²⁹ SiNMR ( ²⁹ Si nuclear magnetic resonance spectrum) or ¹ HNMR (proton nuclear magnetic resonance spectrum). For example, a condensate of silane (II) can be identified by ²⁹ Si NMR chemical shift showing a peak at −40 to −80 PPM.

The polymerizable monomer other than (A) to (E) used in the present invention is not particularly limited. For example, (meth) acrylic acid ester, styrene, vinyl toluene and other aromatic monomers, vinyl acetate, There are vinyl esters such as vinyl propionate and vinyl persuccinate, vinyl cyanides such as (meth) acrylonitrile, vinyl halides such as vinyl chloride and vinylidene chloride, butadiene, and various functional monomers such as (Meth) acrylamide, diacetone acrylamide, vinyl pyrrolidone, glycidyl (meth) acrylate, N-methylol acrylamide, N-butoxymethyl acrylamide, divinylbenzene, methyl vinyl ketone and the like.

  Specific examples of (meth) acrylic acid esters include (meth) acrylic acid alkyl esters having 1 to 18 carbon atoms in the alkyl moiety, and (poly) oxyethylene mono (meth) having 1 to 100 ethylene oxide groups. Acrylate, (poly) oxypropylene mono (meth) acrylate, (meth) acrylic acid hydroxyalkyl ester having 1 to 18 carbon atoms in the alkyl portion, and (poly) oxyethylene di (1) having 1 to 100 ethylene oxide groups And (meth) acrylate. Specific examples of the (meth) acrylic acid alkyl ester include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, and (meth) acrylic acid t-. Examples include butyl, 2-ethylhexyl (meth) acrylate, and dodecyl (meth) acrylate.

  As a method for producing the aqueous resin dispersion of the present invention, an ordinary multistage emulsion polymerization method can be employed. As a typical example, an unsaturated monomer is usually emulsion-polymerized in water at a temperature of 60 to 90 ° C. in the presence of an emulsifier and a polymerization initiator in water in a state where the pH is 4 or less. Is a method in which is repeated a plurality of times. The emulsifier is not particularly limited, and for example, an anionic emulsifier, a nonionic emulsifier, a cationic emulsifier, an amphoteric emulsifier, a polymer emulsifier, and the like can be used. For example, fatty acid salts such as sodium lauryl sulfate, higher alcohol sulfate esters, alkylbenzene sulfonates such as sodium dodecylbenzenesulfonate, polyoxyethylene alkyl ether sulfates, polyoxyethylene polycyclic phenyl ether sulfates, polyoxynonyls Anionic surface activity such as so-called reactive emulsifier having phenyl ether sulfonate, polyoxyethylene-polyoxypropylene glycol ether sulfate, sulfonic acid group or sulfate ester group and polymerizable unsaturated double bond in the molecule Agent: Polyoxyethylene alkyl ether, polyoxyethylene nonylphenyl ether, sorbitan fatty acid ester, polyoxyethylene fatty acid ester, polyoxyethylene-polyoxypropylene block copolymer Or a nonionic surfactant such as a reactive nonionic surfactant having a skeleton and a polymerizable unsaturated double bond in the molecule; a cationic surfactant such as an alkylamine salt or a quaternary ammonium salt ; (Modified) polyvinyl alcohol and the like.

  Although the usage-amount of the said emulsifier is not specifically limited, For example, Preferably it is 1.0-5.0 mass% with respect to the total usage-amount of all the polymerizable monomer components. When the amount of the emulsifier used is increased, the polymerization stability is improved, and when it is decreased, the water resistance can be improved. Moreover, in order to make a high Tg component into a core and a low Tg component into a shell, the amount of emulsifier used in each stage is increased in the amount used in the stage that produces the high Tg component than the amount used in the stage that produces the low Tg component. It is preferable.

  The polymerization method for emulsion polymerization of the aqueous resin dispersion of the present invention is a monomer batch charging method in which monomers are charged in a batch, a monomer dropping method in which monomers are continuously dropped, or a single amount. Examples include a pre-emulsion method in which a body, water and an emulsifier are mixed and emulsified in advance, and these are added dropwise, or a combination of these. At this time, the method of using the polymerization initiator is not particularly limited. In addition, the Si-containing compound (E) can be used by simultaneously performing a condensation reaction of hydrolyzable silane and radical polymerization of an unsaturated monomer and / or preceded by a condensation reaction of hydrolyzable silane. An emulsion polymerization method for proceeding radical polymerization of a monomer or a method for proceeding condensation reaction of hydrolyzable silane after proceeding radical polymerization of an unsaturated monomer is used.

The polymerization initiator used for emulsion polymerization of the aqueous resin dispersion of the present invention is a generally used radical initiator. Radical polymerization initiators generate radicals by heat or reducing substances to cause addition polymerization of polymerizable monomers, and include water-soluble or oil-soluble persulfates, peroxides, and azobis compounds. . Specifically, potassium persulfate, sodium persulfate, ammonium persulfate, hydrogen peroxide, t-butyl hydroperoxide, t-butyl peroxybenzoate, 2,2-azobisisobutyronitrile, 2,2-azobis ( 2-diaminopropane) hydrochloride, 2,2-azobis (2,4-dimethylvaleronitrile), and the like, preferably water-soluble. When acceleration of the polymerization rate or a low temperature reaction is desired, a reducing agent such as sodium bisulfite, ferrous chloride, ascorbic acid, formaldehyde sulfooxylate salt or the like can be used in combination with the radical polymerization initiator.
A molecular weight modifier can be used in the emulsion polymerization as required. Specific examples include dodecyl mercaptan and butyl mercaptan. The method of use is not particularly limited, but it is preferably used in the shell part, and the amount is preferably 2% or less of the total monomer amount.

In order to maintain long-term dispersion stability of the emulsion, the aqueous resin dispersion of the present invention is a basic substance such as basic organic compounds such as amines such as ammonia and dimethylaminoethanol, sodium hydroxide, potassium hydroxide. It is preferable to adjust the pH within a range of 5 to 10 using a basic inorganic compound such as an alkali metal salt.
In addition, in the aqueous resin dispersion of the present invention, components usually added and blended in water-based paints, such as thickeners, film forming aids, plasticizers, antifreezing agents, antifoaming agents, dyes, preservatives, ultraviolet rays An absorber, a light stabilizer, etc. can be arbitrarily mix | blended.

Specific examples of thickeners include polyvinyl alcohol (including partially saponified polyvinyl acetate), polymer dispersion stabilizers such as methylcellulose, hydroxyethylcellulose, and polyvinylpyrrolidone, and other polyether-based and polycarboxylic acid-based thickeners. Etc.
Specific examples of film forming aids include diethylene glycol monobutyl ether, ethylene glycol monobutyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, ethylene glycol mono 2-ethylhexyl ether, 2,2,4-trimethyl-1,3-butanediol iso Examples include butyrate, diisopropyl glutarate, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, tripropylene glycol n-butyl ether, dipropylene glycol methyl ether, and tripropylene glycol methyl ether. These film-forming aids can be arbitrarily blended alone or in combination.
Specific examples of the plasticizer include dibutyl phthalate and dioctyl phthalate.
Specific examples of the antifreezing agent include propylene glycol and ethylene glycol.

  There are benzophenone series, benzotriazole series, and triazine series as ultraviolet absorbers. Specific examples of benzophenone ultraviolet absorbers include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4- Methoxybenzophenone-5-sulfonic acid, 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-n-dodecyloxybenzophenone, 2-hydroxy-4-benzyloxybenzophenone, bis (5-benzoyl-4- Hydroxy-2-methoxyphenyl) methane, 2,2′-dihydroxy-4-methoxybenzophenone, 2,2′-dihydroxy-4,4′dimethoxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, 4 -Dodecyloxy- - hydroxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxy benzophenone, and the like 2-hydroxy-4-stearyloxy benzophenone.

Specific examples of radically polymerizable benzophenone-based UV absorbers include 2-hydroxy-
4-acryloxybenzophenone, 2-hydroxy-4-methacryloxybenzophenone, 2-hydroxy-5-acryloxybenzophenone, 2-hydroxy-5-methacryloxybenzophenone, 2-hydroxy-4- (acryloxy-ethoxy) benzophenone, 2 -Hydroxy-4- (methacryloxy-ethoxy) benzophenone, 2-hydroxy-4- (methacryloxy-diethoxy) benzophenone, 2-hydroxy-4- (acryloxy-triethoxy) benzophenone and the like.

  Specific examples of the benzotriazole ultraviolet absorber include 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-5′-tert-butylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) benzotriazole, 2- (2-hydroxy-5-tert-octylphenyl) benzotriazole, 2- (2-hydroxy-3,5- Di-tert-octylphenyl) benzotriazole, 2- [2′-hydroxy-3 ′, 5′-bis (α, α′-dimethylbenzyl) phenyl] benzotriazole), methyl-3- [3-tert-butyl -5- (2H-benzotriazol-2-yl) -4-hydroxyphenyl] propionate and polyethylene Condensate with glycol (molecular weight 300) (product name: TINUVIN 1130, manufactured by Ciba-Geigy Corporation), isooctyl-3- [3- (2H-benzotriazol-2-yl) -5-tert-butyl-4-hydroxy Phenyl] propionate (manufactured by Ciba Geigy Japan, product name: TINUVIN 384), 2- (3-dodecyl-5-methyl-2-hydroxyphenyl) benzotriazole (manufactured by Ciba Geigy Japan, product name: TINUVIN 571), 2 -(2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-amylphenyl) benzotriazole , 2- (2′-Hydroxy-4′-octoxyphenyl) benzotria 2- [2′-hydroxy-3 ′-(3 ″, 4 ″, 5 ″, 6 ″ -tetrahydrophthalimidomethyl) -5′-methylphenyl] benzotriazole, 2,2-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol], 2- (2H-benzotriazol-2-yl) -4,6-bis (1-methyl-1-phenylethyl) phenol (manufactured by Nippon Ciba-Geigy Co., Ltd., product name: TINUVIN900).

Specifically, as a radical polymerizable benzotriazole-based ultraviolet absorber, 2- (2′-hydroxy-5′-methacryloxyethylphenyl) -2H-benzotriazole (manufactured by Otsuka Chemical Co., Ltd., product name: RUVA-) 93), 2- (2′-hydroxy-5′-methacryloxyethyl-3-tert-butylphenyl) -2H-benzotriazole, 2- (2′-hydroxy-5′-methacrylyloxypropyl-3-tert) -Butylphenyl) -5-chloro-2H-benzotriazole, 3-methacryloyl-2-hydroxypropyl-3- [3 '-(2 "-benzotriazolyl) -4-hydroxy-5-tert-butyl] Phenyl propionate (manufactured by Nippon Ciba-Geigy Co., Ltd., product name: CGL-104).
Specific examples of triazine-based ultraviolet absorbers include TINUVIN400 (product name, manufactured by Ciba Geigy Japan).

As the light stabilizer, hindered amine light stabilizers are preferable, among them, those having low basicity are more preferable, and those having a base constant (pKb) of 8 or more are particularly preferable. Specifically, bis (2,2,6,6-tetramethyl-4-piperidyl) succinate, bis (2,2,6,6-tetramethylpiperidyl) sebacate, bis (1,2,2,6, 6-pentamethyl-4-piperidyl) 2- (3,5-di-tert-butyl-4-hydroxybenzyl) -2-butylmalonate, 1- [2- [3- (3,5-di-tert- Butyl-4-hydroxyphenyl) propynyloxy] ethyl] -4- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propynyloxy] -2,2,6,6-tetramethylpiperidine, A mixture of bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and methyl-1,2,2,6,6-pentamethyl-4-piperidyl-sebacate (Nippon Ciba Geigy ( ), Product name: TINUVIN292), bis (1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate, TINUVIN123 (product name, manufactured by Nihon Ciba-Geigy Corporation), and the like.

  Specific examples of the radical polymerizable hindered amine light stabilizer include 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate, 1,2,2,6,6-pentamethyl-4-piperidyl acrylate, 2, 2,6,6-tetramethyl-4-piperidyl methacrylate, 2,2,6,6-tetramethyl-4-piperidyl acrylate, 1,2,2,6,6-pentamethyl-4-iminopiperidyl methacrylate, 2, 2,6,6, -tetramethyl-4-iminopiperidyl methacrylate, 4-cyano-2,2,6,6-tetramethyl-4-piperidyl methacrylate, 4-cyano-1,2,2,6,6- Examples include pentamethyl-4-piperidyl methacrylate.

In the present invention, the ultraviolet absorber and / or light stabilizer is introduced into the aqueous resin dispersion by being present during emulsion polymerization for producing the aqueous resin dispersion, and the ultraviolet absorber and / or light stabilizer is formed into a film. A method of introducing by mixing with an auxiliary agent and adding to an aqueous resin dispersion, an ultraviolet absorber and / or a light stabilizer are mixed with a film forming auxiliary agent, emulsified by adding a surfactant and water, The method of introduce | transducing by adding to an aqueous resin dispersion is mentioned. In addition, when an ultraviolet absorber and a light stabilizer are used in combination, it exhibits excellent durability due to a synergistic effect.
The aqueous resin dispersion of the present invention preferably has an average particle size of the dispersoid of 30 to 500 nm. The mass ratio of the dispersoid (solid content) in the obtained emulsion to the aqueous medium as the dispersion medium is 70/30 or less, preferably 30/70 or more and 65/35 or less.

  The water-based resin dispersion of the present invention is useful as a coating material, a ground treatment material or finishing material for building materials, a paper processing agent, or a finishing material for woven fabrics and nonwoven fabrics, and specifically as a finishing material for coating materials and building materials. Paints or building finishing materials for various bases, such as concrete, cement mortar, slate board, calcite board, gypsum board, extruded board, inorganic building materials such as expandable concrete, building materials based on woven or non-woven fabrics, and metal building materials Main materials and top coats for multilayer finish coating materials, thin finish coating materials, thick finish coating materials, stone-like finish materials, synthetic paint emulsion paints such as gloss paint, metal paints, wood paints, tiles It is useful as a coating material.

  The present invention will be described in detail with reference to examples and comparative examples, but the present invention is not limited to these examples. In addition, the part and% in an Example and a comparative example represent a mass part and the mass%, respectively. Moreover, about the physical-property test of the obtained aqueous resin dispersion, the coating material was adjusted with the compounding composition shown below using this aqueous resin dispersion, and the test was implemented according to the test method shown below.

<Coating composition>
-Preparation of pigment dispersion Dispersant: Pig. Disperser MD20
(Product name, manufactured by BASF Japan Ltd.) 5.35 parts Ammonia water 0.50 parts Propylene glycol 23.50 parts Water 147.50 parts Taipei CR-97 (trade name, manufactured by Ishihara Sangyo Co., Ltd.) 333.50 Part Antifoam: BYK-028
(Trade name, manufactured by Big Chemie Japan Co., Ltd.) 2.85 parts The above-mentioned composition was dispersed for 20 minutes in a tabletop sand mill to obtain a pigment dispersion.
・ Production of enamel paint Each aqueous resin dispersion (solid content conversion) 500.00 parts Film-forming aid (the following amounts are for weather resistance evaluation)
50 parts of ethylene glycol monobutyl ether and 50 parts of water
100.00 parts CS-12 (product name, manufactured by Chisso Corporation) 50.00 parts The above pigment dispersion 513.20 parts Thickener: Adecanol UH-438 (Asahi Denka Kogyo Co., Ltd.)
10% aqueous solution

<Test method>
-Evaluation of polymerization stability The aqueous resin dispersion obtained after the emulsion polymerization was filtered through a 100-mesh filter cloth, and the residue mass was divided by the mass of the aqueous resin dispersion to obtain the residue rate.
(Judgment criteria) ○: Residue rate is less than 100 ppm
Δ: Residue rate is 100 ppm or more
X: Generation of a large amount of aggregates and measurement of particle diameter The average particle diameter of the obtained aqueous resin dispersion was measured with a Microtrac particle size distribution meter manufactured by Leeds & Northrup.
・ Measurement of solid content ratio of aqueous resin dispersion Weigh accurately about 1 g of aqueous resin dispersion in an aluminum pan of which mass is known in advance and dry it at 105 ° C. for 3 hours with a constant temperature dryer. The sample is allowed to cool for 30 minutes in a desiccator and then weighed accurately. The solid content was obtained by dividing the mass after drying of the substance by the mass before drying.

・ Minimum deposition temperature (MFT)
The object was coated on an aluminum plate placed on a thermal gradient tester with a 0.1 mm applicator and dried, and the highest temperature at which cracks occurred in the coating film was defined as the lowest film formation temperature (MFT). . -Weather resistance The above-mentioned enamel coating composition was applied to a wire coater No. 50 was applied to an alumite sulfate plate and dried at 50 ° C. for 1 week. Subsequently, an exposure test (rain cycle; 18 minutes / 2 hours, black panel temperature 60 to 66 ° C.) was performed using a sunshine type weatherometer (Suga Test Instruments Co., Ltd., WEL-SUN-DC). Changes in appearance after 2000 hours of exposure were observed. Judgment criteria are as follows.
A: No change.
○;
Δ: Shiny and partially cracked.
X: Cracks are seen on the entire surface with glossiness.

-Blocking resistance The above-mentioned enamel coating composition was adjusted with a film forming aid (ethylene glycol monobutyl ether and CS-12) added so as to have an MFT of 10 ° C. After forced drying for 5 minutes, move quickly into a dryer at 50 ° C., leave it for 1 minute, place gauze on the coating surface, place a weight on it, and apply a load of 1.0 kg / cm ² for 10 minutes It was. And after cooling to normal temperature, gauze was peeled off slowly, the state of the coating film was observed visually, and it evaluated according to the following reference | standard.
A: There is almost no trace of gauze.
○: Some traces of gauze are seen.
Δ: Reticulated traces.
X: It is difficult to peel off the gauze.

[Example 1]
In a reaction vessel equipped with a stirrer, reflux condenser, dropping tank and thermometer, 578.5 parts of water, anionic reactive surfactant (Product name: Aqualon KH-10, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 1 5 parts after adding 15 parts of 2% aqueous solution of ammonium persulfate after adding 6 parts and raising the temperature in the reaction vessel to 80 ° C., 146 parts of methyl methacrylate, 250 parts of cyclohexyl methacrylate, 4 parts of methacrylic acid 4 Parts, γ-methacryloxypropyltrimethoxysilane (SZ6030, manufactured by Toray Dow Corning Co., Ltd.), anionic reactive surfactant (product name: Aqualon KH-10, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 41.52 parts of 25% solution, 20 parts of 20% aqueous solution of nonionic surfactant (product name: Emulgen 120, manufactured by Kao Corporation), 2% aqueous solution of ammonium persulfate 20 parts, to flow over a period of 90 minutes from the dropping tank emulsified mixture comprising water 170.27 parts. During the inflow, the temperature of the reaction vessel is maintained at 80 ° C. After the inflow is completed, the temperature of the reaction vessel is raised to 80 ° C. and maintained for 30 minutes.

Next, 332 parts of methyl methacrylate, 242 parts of n-butyl acrylate, 16 parts of methacrylic acid, 10 parts of 2-hydroxyethyl methacrylate, 6 parts of dodecyl mercaptan (DDM), 14.4 parts of a 25% solution of KH10, An emulsified mixture consisting of 30 parts of a 2% aqueous solution of ammonium persulfate and 299.39 parts of water is allowed to flow in over 105 minutes. During the inflow, the temperature of the reaction vessel is maintained at 80 ° C. After the inflow is completed, 67 parts of water is added and the temperature of the reaction vessel is raised to 80 ° C. and maintained for 90 minutes.
Then, it cools to room temperature. The pH after cooling was 2.6. Further, the pH was adjusted to 8.5 using a 25% aqueous ammonia solution, followed by filtration through a 100 mesh wire net. The dry mass of the filtered agglomerates was a slight 30 ppm with respect to the total monomers. The obtained aqueous resin dispersion had a solid content of 45.5% and a particle size of 115 nm.

[Example 2]
An aqueous resin dispersion was obtained in the same manner as in Example 1 except that the type and amount of the polymerizable monomer used in the first stage and the second stage were changed as shown in Table 1. In addition, the quantity of each polymerizable monomer was shown by the ratio with respect to 100 mass parts of polymerizable monomer component total amounts used at both stages.

[Example 3]
In a reaction vessel equipped with a stirrer, reflux condenser, dropping tank and thermometer, 578.5 parts of water, anionic reactive surfactant (Product name: Aqualon KH-10, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 1 5 parts after adding 15 parts of a 2% aqueous solution of ammonium persulfate and adding 245 parts of methyl methacrylate, 250 parts of cyclohexyl methacrylate, 5 parts of methacrylic acid. Parts, γ-methacryloxypropyltrimethoxysilane (SZ6030, manufactured by Toray Dow Corning Co., Ltd.), anionic reactive surfactant (product name: Aqualon KH-10, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 48 parts of 25% solution, 20 parts of 20% aqueous solution of nonionic surfactant (product name: Emulgen 120, manufactured by Kao Corporation), 2% aqueous solution of ammonium persulfate 25 , To flow over 105 minutes from the dropping tank emulsified mixture comprising water 212.89 parts. During the inflow, the temperature of the reaction vessel is maintained at 80 ° C. After the inflow is completed, the temperature of the reaction vessel is raised to 80 ° C. and maintained for 30 minutes.

Next, 273 parts of methyl methacrylate, 202 parts of n-butyl acrylate, 15 parts of methacrylic acid, 10 parts of 2-hydroxyethyl methacrylate, 5 parts of dodecyl mercaptan, 12 parts of a 25% solution of KH10, 2% of ammonium persulfate An emulsified mixed solution consisting of 25 parts of an aqueous solution and 256.09 parts of water is allowed to flow in over 90 minutes. During the inflow, the temperature of the reaction vessel is maintained at 80 ° C. After the inflow is completed, 67 parts of water is added and the temperature of the reaction vessel is raised to 80 ° C. and maintained for 90 minutes.
Then, it cools to room temperature. The pH after cooling was 2.6. Further, a 25% aqueous ammonia solution was added to adjust the pH to 8.5, followed by filtration through a 100 mesh wire net. The dry mass of the filtered agglomerates was a slight 30 ppm with respect to the total monomers. The obtained aqueous resin dispersion had a solid content of 45.5% and a particle size of 115 nm.

[Example 4]
An aqueous resin dispersion was obtained in the same manner as in Example 4 except that the type and amount of the polymerizable monomer used in the first stage and the second stage were changed as shown in Table 1. In addition, the quantity of each polymerizable monomer was shown by the ratio with respect to 100 mass parts of polymerizable monomer component total amounts used at both stages.

[Example 5]
In a reaction vessel equipped with a stirrer, reflux condenser, dropping tank and thermometer, 578.5 parts of water, anionic reactive surfactant (Product name: Aqualon KH-10, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 1 5 parts after adding 6 parts and raising the temperature in the reaction vessel to 80 ° C. and adding 15 parts of a 2% aqueous solution of ammonium persulfate, 289 parts of methyl methacrylate, 200 parts of cyclohexyl methacrylate, 2 parts of methacrylic acid 2 -6 parts hydroxyethyl, 5 parts methacrylic acid, 30 parts γ-methacryloxypropyltrimethoxysilane (SZ6030, manufactured by Toray Dow Corning Co., Ltd.), anionic reactive surfactant (product name: Aqualon KH-10, No. 1) 48 parts of a 25% solution of Ichi Kogyo Seiyaku Co., Ltd. and 20 parts of a 20% aqueous solution of a nonionic surfactant (product name: Emulgen 120, manufactured by Kao Corporation) 2% aqueous solution of 25 parts of ammonium persulfate, the emulsion mixture to flow over a period of 105 minutes from the dropping tank of water 212.89 parts. During the inflow, the temperature of the reaction vessel is maintained at 80 ° C. After the inflow is completed, the temperature of the reaction vessel is raised to 80 ° C. and maintained for 30 minutes.

Next, 196 parts of methyl methacrylate, 50 parts of cyclohexyl methacrylate, 217 parts of n-butyl acrylate, 20 parts of 2-hydroxyethyl methacrylate, 10 parts of methacrylic acid, 5 parts of acrylic acid, 2 parts of acrylamide, 25% of KH10 An emulsion mixture consisting of 12 parts of a solution, 25 parts of a 2% aqueous solution of ammonium persulfate, and 251.09 parts of water is allowed to flow in over 90 minutes. During the inflow, the temperature of the reaction vessel is maintained at 80 ° C. After the inflow is completed, 67 parts of water is added and the temperature of the reaction vessel is raised to 80 ° C. and maintained for 90 minutes.
Then, it cools to room temperature. The pH after cooling was 2.6. Further, the pH was adjusted to 8.5 using a 25% aqueous ammonia solution, followed by filtration through a 100 mesh wire net. The dry mass of the filtered agglomerates was a slight 30 ppm with respect to the total monomers. The obtained aqueous resin dispersion had a solid content of 45.5% and a particle size of 115 nm.

[Example 6]
An aqueous resin dispersion was obtained in the same manner as in Example 5, except that the type and amount of the polymerizable monomer used in the first stage and the second stage were changed as shown in Table 1. In addition, the quantity of each polymerizable monomer was shown by the ratio with respect to 100 mass parts of polymerizable monomer component total amounts used at both stages.

[Example 7]
In a reaction vessel equipped with a stirrer, reflux condenser, dropping tank and thermometer, 578.5 parts of water, anionic reactive surfactant (Product name: Aqualon KH-10, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 1 5 parts after adding 6 parts and raising the temperature in the reaction vessel to 80 ° C. and adding 15 parts of a 2% aqueous solution of ammonium persulfate, 289 parts of methyl methacrylate, 200 parts of cyclohexyl methacrylate, 2 parts of methacrylic acid 2 -6 parts of hydroxyethyl, 5 parts of methacrylic acid, 40 parts of a 30% solution of an anionic surfactant (NEWCOL-707SF, Nippon Emulsifier), nonionic surfactant (product name: Emulgen 120, manufactured by Kao Corporation) An emulsion mixture consisting of 20 parts of 20% aqueous solution, 25 parts of 2% aqueous solution of ammonium persulfate and 240.89 parts of water is allowed to flow in from the dropping tank over 105 minutes. In addition, from 5 minutes after the start of dripping, 30 parts of γ-methacryloxypropyltrimethoxysilane (SZ6030, manufactured by Toray Dow Corning Co., Ltd.), dimethyldimethoxysilane (AY43-004, Toray Dow Corning Co., Ltd.) A mixed solution of 32 parts of methyltrimethoxysilane (SZ6070, manufactured by Toray Dow Corning Co., Ltd.) is dropped from another dropping tank over 90 minutes. During the inflow, the temperature of the reaction vessel is maintained at 80 ° C. After the inflow of the emulsified mixture is completed, the temperature of the reaction vessel is raised to 80 ° C. and maintained for 30 minutes.

Next, 196 parts of methyl methacrylate, 50 parts of cyclohexyl methacrylate, 217 parts of n-butyl acrylate, 20 parts of 2-hydroxyethyl methacrylate, 10 parts of methacrylic acid, 5 parts of acrylic acid, 2 parts of acrylamide, NEWCOL-707SF An emulsion mixture consisting of 10 parts of a 30% solution, 25 parts of a 2% aqueous solution of ammonium persulfate, and 253.09 parts of water is allowed to flow in over 90 minutes. During the inflow, the temperature of the reaction vessel is maintained at 80 ° C. After the inflow is completed, 67 parts of water is added and the temperature of the reaction vessel is raised to 80 ° C. and maintained for 90 minutes.
Then, it cools to room temperature. The pH after cooling was 2.6. Further, the pH was adjusted to 8.5 using a 25% aqueous ammonia solution, followed by filtration through a 100 mesh wire net. The dry mass of the filtered agglomerates was a slight 30 ppm with respect to the total monomers. The obtained aqueous resin dispersion had a solid content of 45.5% and a particle size of 115 nm.

[Example 8]
In a reaction vessel equipped with a stirrer, reflux condenser, dropping tank and thermometer, 578.5 parts of water, anionic reactive surfactant (Product name: Aqualon KH-10, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 1 5 parts after adding 15 parts of a 2% aqueous solution of ammonium persulfate and adding 239 parts of methyl methacrylate, 250 parts of cyclohexyl methacrylate, methacrylic acid 2 -6 parts hydroxyethyl, 5 parts methacrylic acid, 5 parts UV absorber (TINUVIN400, manufactured by Ciba Geigy Japan), 5 parts light stabilizer (TINUVIN123, manufactured by Ciba Geigy Japan), anionic surfactant 40 parts of a 30% solution of (NEWCOL-707SF, Japanese emulsifier), nonionic surfactant (product name: Emulgen 120, manufactured by Kao Corporation) 20% aqueous solution 20 parts of a 2% aqueous solution of 25 parts of ammonium persulfate, to flow over 105 minutes from the dropping tank emulsified mixture comprising water 252.89 parts. In addition, from 5 minutes after the start of dripping, 30 parts of γ-methacryloxypropyltrimethoxysilane (SZ6030, manufactured by Toray Dow Corning Co., Ltd.), dimethyldimethoxysilane (AY43-004, Toray Dow Corning Co., Ltd.) A mixed solution of 32 parts of methyltrimethoxysilane (SZ6070, manufactured by Toray Dow Corning Co., Ltd.) is dropped from another dropping tank over 90 minutes. During the inflow, the temperature of the reaction vessel is maintained at 80 ° C. After the inflow of the emulsified mixture is completed, the temperature of the reaction vessel is raised to 80 ° C. and maintained for 30 minutes.

Next, 111 parts of methyl methacrylate, 150 parts of cyclohexyl methacrylate, 202 parts of n-butyl acrylate, 20 parts of 2-hydroxyethyl methacrylate, 10 parts of methacrylic acid, 5 parts of acrylic acid, 2 parts of acrylamide, NEWCOL-707SF An emulsion mixture consisting of 10 parts of a 30% solution, 25 parts of a 2% aqueous solution of ammonium persulfate, and 253.09 parts of water is allowed to flow in over 90 minutes. During the inflow, the temperature of the reaction vessel is maintained at 80 ° C. After the inflow is completed, 67 parts of water is added and the temperature of the reaction vessel is raised to 80 ° C. and maintained for 90 minutes.
Then, it cools to room temperature. The pH after cooling was 2.6. Further, the pH was adjusted to 8.5 using a 25% aqueous ammonia solution, followed by filtration through a 100 mesh wire net. The dry mass of the filtered agglomerates was a slight 30 ppm with respect to the total monomers. The obtained aqueous resin dispersion had a solid content of 45.5% and a particle size of 115 nm.

[Comparative Example 1]
An aqueous resin dispersion was obtained in the same manner as in Example 1 except that the type and amount of the polymerizable monomer used in the first stage and the second stage were changed as shown in Table 1. However, since the polymerization stability was considerably poor and a large amount of aggregates were generated, no other evaluation was performed. In addition, the quantity of each polymerizable monomer was shown by the ratio with respect to 100 mass parts of polymerizable monomer component total amounts used at both stages.

[Comparative Example 2]
In a reaction vessel equipped with a stirrer, reflux condenser, dropping tank and thermometer, 578.5 parts of water, anionic reactive surfactant (Product name: Aqualon KH-10, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 1 5 parts after adding 15 parts of a 2% aqueous solution of ammonium persulfate and adding 246 parts of methyl methacrylate, 100 parts of cyclohexyl methacrylate, acrylic acid n -41.52 parts of a 25% solution of 50 parts of butyl, 4 parts of methacrylic acid, an anionic reactive surfactant (product name: Aqualon KH-10, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), nonionic surfactant (Product name: Emulgen 120, manufactured by Kao Corporation) 20% aqueous solution 20 parts, ammonium persulfate 2% aqueous solution 20 parts, water 150.27 parts emulsified mixture over 90 minutes from dropping tank It is allowed to flow. During the inflow, the temperature of the reaction vessel is maintained at 80 ° C. After the inflow is completed, the temperature of the reaction vessel is raised to 80 ° C. and maintained for 30 minutes.

Next, 342 parts of methyl methacrylate, 242 parts of n-butyl acrylate, 16 parts of methacrylic acid, 6 parts of dodecyl mercaptan, 14.4 parts of a 25% solution of KH10, 30 parts of a 2% aqueous solution of ammonium persulfate, water 301 An emulsion mixture consisting of 79 parts is allowed to flow in over 105 minutes. During the inflow, the temperature of the reaction vessel is maintained at 80 ° C. After the inflow is completed, 64.6 parts of water are added, and the temperature of the reaction vessel is kept at 80 ° C. for 90 minutes.
Then, it cools to room temperature. The pH after cooling was 2.6. Further, a 25% aqueous ammonia solution was added to adjust the pH to 8.5, followed by filtration through a 100 mesh wire net. The dry mass of the filtered agglomerates was a slight 30 ppm with respect to the total monomers. The obtained aqueous resin dispersion had a solid content of 45.7% and a particle size of 115 nm.

[Comparative Example 3]
In a reaction vessel equipped with a stirrer, reflux condenser, dropping tank and thermometer, 578.5 parts of water, anionic reactive surfactant (Product name: Aqualon KH-10, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 1 5 parts after adding 6 parts and raising the temperature in the reaction vessel to 80 ° C. and adding 15 parts of a 2% aqueous solution of ammonium persulfate, 250 parts of methyl methacrylate, 250 parts of cyclohexyl methacrylate, γ-methacrylic acid. 30 parts of loxypropyltrimethoxysilane (SZ6030, manufactured by Toray Dow Corning Co., Ltd.), 40 parts of 30% solution of anionic surfactant (NEWCOL-707SF, Nippon Emulsifier), nonionic surfactant (product name: Emulgen) 120, manufactured by Kao Corporation), 20 parts of 20% aqueous solution, 25 parts of 2% aqueous solution of ammonium persulfate, and 220.89 parts of water. To flow over 105 minutes from the dropping funnel. During the inflow, the temperature of the reaction vessel is maintained at 80 ° C. After the inflow is completed, the temperature of the reaction vessel is raised to 80 ° C. and maintained for 30 minutes.

Next, 273 parts of methyl methacrylate, 202 parts of n-butyl acrylate, 15 parts of methacrylic acid, 10 parts of 2-hydroxyethyl methacrylate, 5 parts of dodecyl mercaptan, 10 parts of a 30% solution of NEWCOL-707SF, ammonium persulfate An emulsified mixed solution consisting of 25 parts of a 2% aqueous solution and 258.09 parts of water is allowed to flow in over 90 minutes. During the inflow, the temperature of the reaction vessel is maintained at 80 ° C. After the inflow is completed, 67 parts of water is added and the temperature of the reaction vessel is raised to 80 ° C. and maintained for 90 minutes.
Then, it cools to room temperature. The pH after cooling was 2.6. Further, a 25% aqueous ammonia solution was added to adjust the pH to 8.5, followed by filtration through a 100 mesh wire net. Since the polymerization stability was poor and a large amount of aggregate was generated, no other evaluation was performed.

[Comparative Example 4]
In a reaction vessel equipped with a stirrer, reflux condenser, dropping tank and thermometer, 578.5 parts of water, anionic reactive surfactant (Product name: Aqualon KH-10, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 1
. 6 parts was added and the temperature in the reaction vessel was raised to 80 ° C., and 5 minutes after adding 15 parts of a 2% aqueous solution of ammonium persulfate, 46 parts of methyl methacrylate, 230 parts of cyclohexyl methacrylate, n-acrylic acid n- 20 parts of butyl, 4 parts of methacrylic acid, 10 parts of γ-methacryloxypropyltrimethoxysilane (SZ6030, manufactured by Toray Dow Corning Co., Ltd.), 30 of an anionic surfactant (NEWCOL-707SF, manufactured by Nippon Emulsifier Co., Ltd.) 33.3 parts of a 20% solution, 20 parts of a 20% aqueous solution of a nonionic surfactant (product name: Emulgen 120, manufactured by Kao Corporation), 20 parts of a 2% aqueous solution of ammonium persulfate, and 77.19 parts of water. The emulsified mixed solution is allowed to flow from the dropping tank over 75 minutes. During the inflow, the temperature of the reaction vessel is maintained at 80 ° C. After the inflow is completed, the temperature of the reaction vessel is raised to 80 ° C. and maintained for 30 minutes.

Next, 392 parts of methyl methacrylate, 292 parts of n-butyl acrylate, 16 parts of methacrylic acid, 6 parts of dodecyl mercaptan, 12 parts of a 30% solution of NEWCOL-707SF, 30 parts of a 2% aqueous solution of ammonium persulfate, water 401 An emulsion mixture of 79 parts is allowed to flow in over 120 minutes. During the inflow, the temperature of the reaction vessel is maintained at 80 ° C. After the inflow is completed, 67 parts of water is added and the temperature of the reaction vessel is raised to 80 ° C. and maintained for 90 minutes.
Then, it cools to room temperature. The pH after cooling was 2.6. Further, a 25% aqueous ammonia solution was added to adjust the pH to 8.5, followed by filtration through a 100 mesh wire net. The dry mass of the filtered aggregate was as little as 50 ppm with respect to the total monomer. The obtained aqueous resin dispersion had a solid content of 45.4% and a particle size of 120 nm.

The measurement results of the above tests of the above examples and comparative examples are shown in Table 1 below.
In addition, the mass part of each component of the 1st and 2nd step | paragraph in Table 1 is described by 0.1 time, and abbreviations are as follows. In addition, the Tg value of each homopolymer used for calculating the glass transition temperature (Tg / ° C.) of the polymerizable monomer according to the Fox formula is shown in parentheses.
MMA: Methyl methacrylate (105)
BA: n-butyl acrylate (-45)
BMA: n-butyl methacrylate (22)
2EHA: 2-ethylhexyl acrylate (-55)
CHMA: cyclohexyl methacrylate (83)
2HEMA: 2-hydroxyethyl methacrylate (55)
AA: Acrylic acid (87)
MAA: Methacrylic acid (144)
AAm: Acrylamide (153)
Em120: Emulgen 120
APS: ammonium persulfate DDM: dodecyl mercaptan

The aqueous resin dispersion of the present invention is suitable for paint and coating applications.

Claims (11)

  An aqueous resin dispersion polymerized using two or more kinds of polymerizable monomers having different glass transition temperatures (Tg), and the aqueous resin dispersion has a high Tg with a glass transition temperature (Tg) of 50 ° C. or higher. An aqueous resin dispersion comprising a resin component and a low Tg resin component having a glass transition temperature (Tg) of 40 ° C. or lower, and the glass transition temperature (Tg) of the entire aqueous resin dispersion being 40 ° C. or higher. .   2. The aqueous resin dispersion according to claim 1, wherein the mass ratio of the high Tg resin component and the low Tg resin component is high Tg resin component / low Tg resin component (mass ratio) = 35/65 to 70/30. .   The high Tg resin component of the aqueous resin dispersion contains an alkoxysilane group-containing polymerizable monomer (A), a cycloalkyl group-containing polymerizable monomer (B), and a carboxyl group-containing polymerizable monomer (C). The aqueous resin dispersion according to claim 1 or 2.   The amount of the cycloalkyl group-containing polymerizable monomer (B) of the high Tg resin component is 10 to 80% by mass of the total monomer of the high Tg resin component. The aqueous resin dispersion described in 1.   The high Tg resin component and the low Tg resin component of the aqueous resin dispersion contain a carboxyl group-containing polymerizable monomer, and the carboxyl group-containing polymerizable monomer of the high Tg resin component / carboxyl group-containing polymerization of the low Tg resin component. The aqueous resin dispersion according to any one of claims 1 to 4, wherein the functional monomer (mass ratio) is 10/90 to 70/30.   The aqueous resin dispersion according to any one of claims 1 to 5, wherein the high Tg resin component and / or the low Tg resin component of the aqueous resin dispersion contains a hydroxyl group-containing polymerizable monomer (D). . The aqueous resin dispersion according to any one of claims 1 to 6, further comprising a Si-containing compound (E) represented by the following formula (1).
_{^{(R 1) n -Si- (R}} 2) 4-n (1)
(In the formula, n is an integer of 0 to 3, and R ¹ is hydrogen, an aliphatic hydrocarbon group having ^{1 to} 16 carbon atoms, an aryl group having 5 to 10 carbon atoms, a cycloalkyl group having 5 to 6 carbon atoms, vinyl. One or more groups selected from a group, an alkyl acrylate group having 1 to 10 carbon atoms, or an alkyl methacrylate group having 1 to 10 carbon atoms, and n R ^{1 s} may be the same or different. R ² is one or more groups selected from an alkoxy group having 1 to 8 carbon atoms, an acetoxy group, and a hydroxyl group, and 4-n R ² may be the same or different.   8. The structure according to any one of claims 1 to 7, wherein the high Tg resin component has a structure comprising a central portion (core) of the aqueous resin dispersion particles, and the low Tg resin component comprises an outer portion (shell) of the aqueous resin dispersion particles. An aqueous resin dispersion according to any one of the above.   The aqueous resin dispersion according to any one of claims 1 to 8, which is obtained by emulsion polymerization in two or more steps.   The aqueous resin dispersion according to any one of claims 1 to 9, wherein the aqueous resin dispersion is produced at a pH of 4 or less during emulsion polymerization.   A paint comprising the aqueous resin dispersion according to claim 1, wherein the coating film is excellent in blocking resistance.