JPS63132976A - Resin composition for aqueous coating - Google Patents

Abstract

PURPOSE:To provide the titled composition of outstanding whiteness, capable of reducing the amount of titanium dioxide to be incorporated, comprising an aqueous binder and a specific non-film-forming polymer emulsion. CONSTITUTION:The objective composition comprising (A) 100pts.wt. on a solid basis of an aqueous binder, (B) 0.1-9,900pts.wt. of a non-film-forming polymer emulsion prepared by emulsion polymerization, in the presence of (i) 0.1-30pts. wt. of a product made by emulsion polymerization between a) 5-70wt% of an alpha,beta-ethylenic unsaturated carboxylic acid, b), 5-95wt% of a (meth)acrylic 1-8C alkyl ester, and c) 0-50wt% of an aromatic vinyl compound, of (ii) 70-99.9pts.wt. of a mixture consisting of d) 2-9wt% of an alpha,beta-ethylenic unsaturated carboxylic acid, e) 50-98wt% of an aromatic vinyl compound, and f) 0-48wt% of another copolymerizable monomer and furthermore, if needed, (C) pigments.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to a new and useful resin composition for water-based paints, which provides excellent whiteness when formed into a film with a suitable binder, and The binder refers to a resin composition for an aqueous paint containing substantially insoluble, non-film-forming polymer particles.

[Prior art and its problems] Conventionally, the above-mentioned resin composition for water-based paints uses monovinylidene aromatic particles as non-film-forming polymer fine particles, as disclosed in Japanese Patent Publication No. 46-6524. class a
Those using emulsion particles with a particle diameter of 0.3 to 0.8 μm obtained by emulsion polymerization of owt% or more and up to 20wt% of other monomers, and those using JP-A-2006-120002, which the present inventors previously applied for a patent for. Disclosed in Publication No. 61-62510,
In the presence of an emulsion obtained by emulsion polymerization of a polymerizable vinyl monomer and, if necessary, a polyfunctional crosslinkable matrix, a monomer mixture having a solubility parameter difference of 0.1 or more from the above polymer is prepared. A method using emulsion particles having small pores inside obtained by emulsion polymerization is known.

A problem with such prior art resins for water-based paints is that the whiteness of the non-film-forming resin emulsions is not satisfactory. For example, Tokuko Sho 46-6524
JP-A-61-625 than that obtained according to the publication No.
Although the non-film-forming polymer fine particles obtained according to Publication No. 10 have superior whiteness, the current situation is that this whiteness has not been utilized to replace titanium oxide, which is a conventional white pigment. .

[Means for Solving the Problems] In view of the above points, the present inventors have developed a resin for water-based paints containing fine particles having a whiteness superior to that of non-film-forming polymer fine particles obtained by conventional techniques. As a result of intensive studies to obtain a composition, it was found that a water-based paint composition containing the fine particles obtained by the following specific composition as an essential component has satisfactory performance, and the present invention was completed.

That is, the present invention comprises: (1) [1] 1 part by weight of an aqueous binder (based on solid content); and [2] (A) 5 to 70 wt% of α,β-ethylenically inert saturated carboxylic acid. 5 to 95 wt% of (meth)acrylic acid alkyl ester having an alkyl group, 0 to sowt% of an aromatic vinyl compound, and 0 to sowt% of other monomers that can be copolymerized with the above components (ratios are based on the total number of components (A)) ) was subjected to emulsion polymerization, and the above (A) component 0.
In the presence of 1 to 30 parts by weight, (B) 2 to 9 wt of α, β, β-ethylene saturated carboxylic acid
%, 50 to 98 wt% of an aromatic vinyl compound, and 0 to 48 wt% of a monomer copolymerizable with these (ratios are based on the total number of components (B)). Non-film-forming polymer emulsion obtained by
The present invention provides a resin composition for an aqueous paint, characterized in that it contains: 0 parts by weight (based on solid content);

First of all, the water-based binder that constitutes the present invention can be used without any particular problem as long as it is a binder for general water-based paint compositions such as lysine, flat, cloth, elastic, and metal paint compositions. Specific examples include vinyl resin emulsions, vinyl water-soluble resins, and vinyl resin aqueous dispersions. Such resins may be those obtained from vinyl monomers as described below according to known and commonly used manufacturing methods. Particular limitations include that the glass transition HI of the above resins is 60°C.
The following, and the solid content concentration is 20 to 60 wt.
% is preferred.

Next, the non-film-forming resin emulsion (2) will be explained.

Specific examples of α, β, β-ethylene saturated carboxylic acids used to produce component (A) include (meth)acrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, or citraconic acid anhydride. Carboxyl group-containing monomers or dicarboxylic acids such as unsaturated group-containing hydroxyalkyl ester monocarboxylic acids such as adducts of acid anhydride group-containing hanging bodies such as maleic acid and itaconic anhydride with glycol; maleic anhydride, anhydride Examples include unsaturated monomers containing polyhydric carboxylic acid anhydride groups such as itaconic acid, and these monomers can be used alone or as a mixture of two or more. The amount used is 5 based on the total number of ingredients (A).
~yowt%.

Next, the (meth)acrylic acid alkyl ester having a C1-8 linear, branched or cyclic furkyl group constituting component (A) is, for example, methyl (meth)acrylate,
Examples include ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and cyclohexyl (meth)acrylate, and these can be used alone or in combination of two or more. The amount used is (A
) ranges from 5 to 95 wt% based on the total amount of components.

Examples of the aromatic vinyl compound include styrene or derivatives thereof such as styrene, α-methylstyrene, p-tert-butyl-styrene, and p-methylstyrene, which may be used alone or in combination of two or more thereof. The amount used is 0 to 50 wt% based on the total amount of (^) components.

Other examples of monomers that can be copolymerized with these monomers include the following, which can also be used alone or in combination. The range that can be introduced into component (A) is 0 to 50 wt%.

First, examples of hydroxyl group-containing monomers include 2- and droxyethyl (meth)acrylate, 2-hydroxypropyl (
meth)acrylate, 3-hydroxypropyl(meth)
Acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4
-Hydroxyalkyl esters of (meth)acrylic acid such as hydroxybutyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, polyethylene glycol mono(meth)acrylate; polyesters such as maleic acid and fumaric acid; unsaturated group-containing polyhydroxyalkyl esters such as dihydroxyalkyl esters of monovalent carboxylic acids; hydroxyalkyl vinyl ethers such as hydroxyethyl vinyl ether;

Other (substituted) aromatic nucleus-containing (meth)acrylic acid esters such as benzyl (meth)acrylate; diesters of unsaturated dicarboxylic acids and monohydric alcohols such as maleic acid, fumaric acid, and itaconic acid; vinyl acetate, benzoic acid Vinyl, "Beoba" (vinyl ester manufactured by Shell)
Vinyl esters such as [Viscoat 8F, 8F
M, 3F, 3FMJ (fluorine-containing (meth)acrylic monomer manufactured by Osaka Organic Chemical ■), °perfluorocyclohexyl (meth)acrylate, diperfluorocyclohexyl fumarate, or N-1-propyl perfluorooctane Sulfonamide ethyl (meth)acrylate (bar) Fluoroalkyl group-containing vinyl esters: vinyl chloride, vinylidene chloride, vinylidene fluoride, vinyl fluoride, olefins such as chlorotrifluoroethylene, ethylene, propylene; ) Carboxylic acid amide group-containing monomers such as acrylamide, N,N-dimethyl (meth)acrylamide, N-alkoxymethylated (meth)acrylamide, diacetone acrylamide, N-methylol (meth)acrylamide, etc.; p- Styrene sulfonamide, N-methyl-p-
Monomers containing sulfonic acid amide groups, such as styrenesulfonamide, N,N-dimethyl-p-styrenesulfonamide, etc.; N,N-dialkylaminoalkyl (such as N,N-dimethylaminoethyl (meth)acrylate); meth)acrylates or polyvalent carboxylic acid anhydride group-containing monomers such as maleic anhydride and active hydrogen groups and tertiary amino acids that can react with polyvalent carboxylic acid anhydride groups such as N,N-dimethylaminopropylamine. Tertiary amino group-containing monomers such as adducts with compounds having both groups: cyano group-containing monomers such as (meth)acrylonitrile; α, β- such as (meth)acrylic acid hydroxyalkyl esters; Mono-ω-isomers having a phosphoric acid ester group obtained by the condensation reaction of saturated carboxylic acid droxyalkyl esters for ethylenically inert compounds and phosphoric acid esters: sulfonic acids such as 2-acrylamido-2-methylpropanesulfonic acid These include monomers having groups or their organic amine salts.

In addition, in order to improve the durability and solvent resistance of the final non-film-forming polymer particles, the following crosslinkable monomers may be added to the total amount of component (A) as necessary. 0～
It is preferable to contain 30 wt%.

Specific examples of crosslinkable monomers include ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, and trimethylolpropane tri(meth)acrylate.
Monomers having two or more polymerizable unsaturated groups in the molecule, such as acrylate, divinylbenzene, trivinylbenzene, diallyl phthalate, etc.: vinyltriethoxysilane, γ-(meth)acryloyloxypropyltriethoxysilane, γ There are hydrolyzable silyl group-containing bases such as -(meth)acryloyloxypropylmethyldimethoxysilane, γ-(meth)acryloyloxypropyltriethoxysilane, and γ-(meth)acryloyloxypropylmethyljethoxysilane.

In order to produce the component (^), the required amount of each of the above monomer groups may be synthesized by a known and commonly used emulsion polymerization method in the presence of an emulsifier, a polymerization initiator, and water. Examples of emulsifiers used in this case include anionic emulsifiers, nonionic emulsifiers, cationic emulsifiers, other reactive emulsifiers, and substances with surfactant properties such as acrylic oligomers. Also, anionic emulsifiers are preferable because they produce less aggregates during polymerization and provide stable emulsions. Typical nonionic emulsifiers include polyoxyethylene alkylphenol ether, polyoxyethylene alkyl ether, polyoxyethylene higher fatty acid ester, and ethylene oxide-propylene oxide block copolymer, while anionic emulsifiers include alkylbenzene sulfone. Acid alkali gold salt, alkyl sulfate alkali metal salt,
Examples include polyoxyethylene alkylphenol sulfate alkali metal salts. Furthermore, instead of the above-mentioned anionic emulsifier, or in combination with it, a water-soluble oligomer made of polycarboxylic acid or sulfonate can be used. Water-soluble polymeric substances such as polyvinyl alcohol and hydroxyethyl cellulose, which are sometimes used in emulsion polymerization, can be used as protective colloids. When these materials are used (9), the particle size of the emulsion becomes larger and the whiteness becomes better, but on the other hand, the water resistance and weather resistance of the coating film formed with the binder decreases, so The amount used should be 5 wt% or less, preferably 2 wt% or less based on the amount.The amount of the emulsifiers etc. used is 0.1 to 10 w based on the total monomer amount.
It is about t%.

Next, the polymerization initiator is not particularly limited as long as it is commonly used in emulsion polymerization, but specific examples include water-soluble inorganic peroxides such as hydrogen peroxide, ammonium persulfate, potassium persulfate, etc. persulfates such as; organic peroxides such as cumene hydroperoxide and benzoyl peroxide; azobisisobutyronitrile,
There are azo initiators such as azobis(Schiff)valeric acid, and these may be used alone or in combination. The amount used is preferably 0.1 to 2 wt% based on the total monomer mass. It goes without saying that a method known as a so-called redox polymerization method in which these polymerization initiators are used in combination with a metal ion and a reducing agent may also be used.

(^) In the presence of water, preferably ion-exchanged water and an emulsifier, the monomer mixture constituting component (A) is added as is or in an emulsified state to a reaction vessel, all at once, in portions, or continuously. in the presence of the polymerization initiator at a temperature of 0 to 100°C, preferably 30 to 90°C. The ratio of the total monomer content to water is such that the final solid content is 10 to 60 wt%, preferably 15 to 55 wt%.
It should be set within the range of %. Also, (A)
When adjusting the components, emulsion particles are pre-existing in the aqueous phase in order to grow or control the particle size of the resulting component (A). A so-called seed polymerization method may also be used.

In this way, the vinyl copolymer emulsion constituting component (A) can be prepared, and then in the presence of 0.1 to 30 parts by weight based on the solid content of the emulsion, 70 to 70 parts of the monomer mixture constituting component (B) can be prepared. By additionally polymerizing 99.9 parts by weight, (B) was added to the surface of the emulsion particles of component (A).
A non-film-forming polymer fine particle emulsion, which is an essential component of the present invention, can be produced by depositing and polymerizing the components.

Monomers to be used in component (B) of the present invention include α,
β-ethylenically unsaturated carboxylic acid 2 to 98 wt%, aromatic vinyl compound 50 to 98 wt%, and other monomers that can be copolymerized with these 0 to 48 wt% (the above ratios are based on the total amount of component (B)), and these may be appropriately selected from those detailed in the section of component (A).

More preferably, in order to improve the durability and solvent resistance of the target product, a monomer having two or more polymerizable unsaturated bonds as described in the section of component (A) and/or hydration is preferably used in the above-mentioned components. It is preferable to introduce a crosslinkable monobase such as a degradable silyl group-containing monobase, and the amount used is within the range of 0 to 30w1%.

In the polymerization of component (B), the production of a large amount of particles of component (B) alone on a weight basis is contrary to the spirit of the present invention, so the additional use of emulsifiers should be avoided as much as possible.
If necessary, the amount used of component (B) should be 5 wt% or less, preferably 2 wt% or less. Usage amount is 5wt
%, a large amount of emulsion particles consisting solely of component (B) will be generated, and for example, when measuring the particle distribution, an emulsion with two peaks will be produced.

The polymerization initiator and the like are the same as described in the section of component (A).

The final solids concentration should be in the range of 20 to 55 wt%, preferably 30 to 55 wt%;
The particle diameter of the emulsion particles obtained is 0.3 to
The range is 1.5 μm. In addition, non-film-forming polymer particles are generally used by mixing them with the aqueous emulsion, water-soluble resin, or aqueous dispersion as the binder described above. Those that are difficult to solubilize or swell with basic substances such as morpholine and triethylamine are preferable, and more preferably, after contacting the fine particles with the basic substance, the volume of the fine particles changes by at most twice the volume of the fine particles before contact. Should. A substance that causes a volume change of more than twice as much will have a significant lack of stability in applications where it coexists with basic substances for a long period of time.
It cannot withstand use. The non-film-forming polymer emulsion, which is an essential component of the present invention, has a volume change of 2 after contact with a basic substance.
The stability against such basic substances can only be achieved within the range described in the claims of the present invention.

Further, the non-film-forming polymer fine particle emulsion obtained according to the present invention can be powdered by a known and commonly used drying method. For example, spray drying at a temperature of 100-250 °C,
Tray drying or fluidized bed drying can be performed at a temperature of 50 to 70°C.

The particle size of the obtained non-film-forming resin powder is generally an aggregate (secondary particle) of primary particles (fine particles having the same particle size as in emulsion), but if necessary, a dispersant such as an emulsifier,
Can be redispersed in water by adding protective colloids.

The ratio of component (1) to component (2) can be used in the range of 0.1 to 9,900 parts by weight of (1) to 100 parts by weight of (2) on a solid content basis.

Next, specific examples of the pigments of the component (■) include heavy calcium carbonate, light calcium carbonate, magnesium carbonate, precipitated barium ramen acid, mica, and titanium oxide.
Inorganic pigments or fillers such as Kansui powder, powder, kaolin, clay, calcined clay, talc, silica sand, silica lime, ultrafine silica, white carbon, asbestos, pulp powder, dolomite powder, zinc white, carbon black, etc. : Phthalocyanine type, azo type, quinacridone type etc.
11WA pigment or its dispersed pigment. The amount of these pigments used is usually 0 per 1001ff1 part of the component.
~300 heavy lifting parts.

The composition of the present invention can be obtained using these three components, but various additives as shown in the table below can also be blended.

Chisso Cizer C3-12 (Chisso ■ product), butyl carpitol acetate, butyl cellosolve, carpitol, hexylene glycol, cellosolve, dibutyl glycol phthalate, dibutyl phthalate, benzyl alcohol, diisopropyl succinate, Pyca1
94(＾tras chemtcatIndustri
es), Dalyad A (Dow Chemical
Film-forming aids such as al Co, ); and phthalate esters such as dioctyl phthalate, aliphatic dibasic acid esters such as isodecyl succinate and dioctyl adipate, and phosphoric acid esters such as tricresyl phosphate. , glycol esters such as diethylene glycol benzoate, epoxy plasticizers such as epoxidized soybean oil, and various plasticizers such as chlorinated paraffin;
Various anionic and nonionic surfactants: Dispersants such as salts of phosphoric acid derivatives such as pyrophosphoric acid, tripolyphosphoric acid, and hexametaphosphoric acid, salts of polycarboxylic acids, and salts of naphthalenesulfonic acid; mineral spirits, turpentine Drying regulators such as oil: ethylene glycol,
Freezing or thawing stabilizing agents such as propylene glycol, glycerin, and methanol; antifoaming agents such as silicone-based or acrylic oligomers; and other preservatives, but the amount of these added is determined depending on the usage conditions and purpose. be done.

[Effects of the Invention] The resin composition for water-based paints of the present invention has excellent whiteness due to the effect of the non-film-forming polymer particles, so it reduces the amount of pigments used in the past, especially titanium oxide. be able to. The composition of the present invention can be used as general or industrial water-based paints for thin, flat, cloth, elastic, metal, etc., but is not particularly limited thereto.

[Example] Next, the present invention! This will be specifically explained in the Preparation Examples, Examples, and Comparative Examples, but hereinafter all parts and percentages are based on weight unless otherwise specified.

Production Example 1 50 parts of ion-exchanged water and 3.5 parts of emulsifier (2 parts of Emulgen 920 manufactured by Kao Corporation and Emal 1.5 parts of 10) was added and stirred well. Next, heat the reaction vessel, keep the internal temperature at 80°C, and add acrylonitrile (8N>3 parts, n-butyl acrylate (BA)).
6 parts and ethylene glycol dimethacrylate (ED
) l^) 1 part mixture and ammonium persulfate 0,2
A mixture of 5 parts of ion-exchanged water and 5 parts of ion-exchanged water was added dropwise over 1 hour to react, and the mixture was maintained at the same temperature for about 1 hour. Then, while maintaining the internal temperature at 80°C, a mixture of 10 parts of styrene (ST), 13 parts of methyl tatacrylate, 5 parts of methacrylic acid (HAA), 1 part of divinylbenzene (DVB) and A mixture of 0.25 parts of ammonium sulfate and 5 parts of ion-exchanged water was added dropwise over 1 hour to react, and the mixture was maintained at roughly the same temperature for 45 minutes. Thereafter, it was cooled to obtain an intermediate emulsion (A-1). The obtained emulsion had a solid content concentration of 40.1%, a pH of 2.5, and an average particle size of 0.
．． 25 μm (Coulter Counter
(measured value at N-4).

Production Example 2 In a reaction vessel equipped with a stirrer, a reflux condenser, a dropping funnel, a nitrogen introduction tube, and a thermometer, 50 parts of ion-exchanged water and 3.5 parts of an emulsifier (2 parts of Emulgen 920 manufactured by Kao Corporation and Emal 1.5 parts of 10) was added and stirred well. Next, heat the reaction vessel, keep the internal temperature at 80°C, add 5 parts of A, t-
A mixture of 4.5 parts of butyl methacrylate, 0.5 parts of γ-methacryloyloxypropyltrimethoxysilane, and a mixture of 0.25 parts of ammonium persulfate and 5 parts of ion-exchanged water were added dropwise over 1 hour to react. The temperature was maintained at the same temperature. Thereafter, while maintaining the internal temperature at 80°C, 3 parts of ST, 20 parts of HMA, 5 parts of HMA, DVB
A mixture of 2 parts and 0.2 ammonium persulfate
A mixture of 5 parts of ion-exchanged water and 5 parts of ion-exchanged water was added dropwise over 1 hour to cause a reaction, and the mixture was further maintained at the same temperature for 1 hour. Thereafter, it was cooled to obtain an intermediate emulsion (A-2).

The resulting emulsion had a solid content of 40. O%, pH2
, 4, the average particle diameter was 0.27 μm.

Production Example 3 60 parts of ion-exchanged water was charged into a reaction vessel equipped with a stirrer, a reflux condenser, a dropping funnel, a nitrogen introduction tube, and a thermometer.
The temperature was raised to 5°C. Next, 0.5 part of sodium dodecylbenzenesulfonate was dissolved in 10 parts of ion-exchanged water, and HM
A mixture consisting of 17.9 parts of A, 2 parts of MAA, and 11 parts of fAO (ED) is added and emulsified. A mixture of the emulsion, 0.2 parts of ammonium persulfate, and 10 parts of ion-exchanged water was dropped into the reaction vessel for 2 hours to effect polymerization. The reaction was further maintained at the same temperature for 1 hour to complete the reaction.

Thereafter, it is cooled to give 1 q of intermediate emulsion (A-3).
Ta. The obtained emulsion had a solid content concentration of 20.0%, p
H2,1, and the average particle diameter was 0.24 μm.

Production Example 4 60 parts of ion-exchanged water was charged into a reaction vessel equipped with a stirrer, a reflux condenser, a dropping funnel, a nitrogen introduction tube, and a thermometer.
The temperature was raised to 5°C. Next, 0.5 part of sodium dodecylbenzenesulfonate was dissolved in 10 parts of ion-exchanged water, and M)
A mixture consisting of 16.9 parts of IA, 3 parts of HAA, and 1 part of EDHAO is added and emulsified. A mixture of the emulsion, 062 parts of ammonium persulfate, and 10 parts of ion-exchanged water was dropped into the reaction vessel for 2 hours to effect polymerization. The reaction was further maintained at the same temperature for 1 hour to complete the reaction.

Thereafter, the intermediate emulsion (A-4) was cooled to (q
Ta. 1q emulsion has a solid content concentration of 20.2%,
The pH was 2.2, and the average particle size was 0.22 μm.

Production Example 5 (Production of non-film-forming polymer emulsion) In a reaction vessel equipped with a stirrer, reflux condenser, dropping funnel, nitrogen inlet tube and thermometer, 370 parts of ion-exchanged water and intermediate emulsion (^- 1) Pour 100 parts and raise the temperature to 85°C. Next, 7 parts of sodium dodecylbenzenesulfonate was dissolved in 90 parts of ion-exchanged water, and ST 338.0
A mixture consisting of 4 parts, 18.36 parts of HAA, and 83.6 parts of 0V is added and emulsified. A mixture of the emulsion, 3.6 parts of ammonium persulfate, and 80 parts of ion-exchanged water was dropped into the reaction vessel over 2 hours to carry out a reaction. After roughly maintaining the same temperature for 1 hour, it was cooled to obtain the desired emulsion (A-5). (A-5) has a solid content concentration of 40.1%, a pH of 2.7, and an average particle diameter of 0.51 μm.
Met.

Production Example 6 (same as above) 370 parts of ion-exchanged water and 100 parts of intermediate emulsion (A-2) were charged into a reaction vessel equipped with a stirrer, a reflux condenser, a dropping funnel, a nitrogen introduction tube, and a thermometer. Raise the temperature to ℃. Next, 5 parts of sodium dodecylbenzenesulfonate was dissolved in 90 parts of ion-exchanged water, and ST 33
A mixture consisting of 4.8 parts of HAA, 18 parts of HAA, and 7.2 parts of T-methacryloyloxypropyltrimethoxysilane was added and emulsified. The emulsion and ammonium persulfate 3
．． A mixture of 6 parts of ion-exchanged water and 80 parts of ion-exchanged water was dropped into the reaction vessel over 2 hours to carry out the reaction. After roughly maintaining the same temperature for 1 hour, it was cooled to obtain the desired emulsion (A-6). (A-6) has a solid content concentration of 40
．． 0%, I) H2,6, and the average particle size was 0.56 μm.

Production Example 7 (same as above) 190 parts of ion-exchanged water and 300 parts of intermediate emulsion (A-3) were charged into a reaction vessel equipped with a stirrer, a reflux condenser, a dropping funnel, a nitrogen introduction tube, and a thermometer. Raise the temperature to ℃. Next, 5 parts of sodium dodecylbenzenesulfonate was dissolved in 90 parts of ion-exchanged water.ST 32
A mixture consisting of 1.3 parts of HAA, 11.9 parts of HAA, and 86.8 parts of DV is added and emulsified. A mixture of the emulsion, 3.4 parts of ammonium persulfate, and 80 parts of ion-exchanged water was added to the
The mixture is dropped into the reaction vessel over a period of time to allow the reaction to occur. After roughly maintaining the same temperature for 1 hour, it was cooled to obtain the desired emulsion (A-7). (A-7) Solid content Li degree 40.1%, PTT 2.6, average particle size 0.4
It was 9 μm.

Production Example 8 (same as above) 270 parts of ion-exchanged water and 200 parts of intermediate emulsion (^-4) were charged into a reaction vessel equipped with a stirrer, a reflux condenser, a dropping funnel, a nitrogen introduction tube, and a thermometer. Raise the temperature to ℃. Next, 6 parts of sodium dodecylbenzenesulfonate was dissolved in 90 parts of ion-exchanged water, and ST 32
A mixture consisting of 2.2 parts of HAA, 19.8 parts of HAA, and 818 parts of DV was added and emulsified. A mixture of the emulsion, 3.6 parts of ammonium persulfate, and 80 parts of ion-exchanged water was dropped into the reaction vessel over 2 hours to carry out a reaction. After keeping the mixture at roughly the same temperature for 1 hour, it was cooled to obtain the desired emulsion (8-8). (^-8) has a solid content of 40.0%, pH 2.6, and an average particle size of 0.51 μm.
Met.

Comparative Production Example 1 190 parts of ion-exchanged water and 300 parts of intermediate emulsion (A-3) were charged into a reaction vessel equipped with a stirrer, a reflux condenser, a dropping funnel, a nitrogen introduction tube, and a thermometer, and the temperature was raised to 85°C. Increase temperature. Next, 5 parts of sodium dodecylbenzenesulfonate was dissolved in 90 parts of ion-exchanged water, and ST 29
A mixture consisting of 9.2 parts, 34 parts of tAA, and 86.8 parts of DV is added and emulsified. A mixture of the emulsion, 3 to 4 parts of ammonium persulfate, and 80 parts of ion-exchanged water is dropped into the reaction vessel over 2 hours to carry out a reaction. After roughly maintaining the same temperature for 1 hour, it was cooled to obtain a comparative emulsion (B-1). (B-1) has a solid content concentration of 40.1%, a pH of 262, and an average particle diameter of 0.51 μm.
Met.

Comparative Production Example 2 In a reaction vessel equipped with a stirrer, a reflux condenser, a dropping funnel, a nitrogen inlet tube, and a thermometer, 100 parts of ion-exchanged water and 3.5 parts of an emulsifier (2 parts of Emulgen 920 manufactured by Naedosha) were added. and 1.5 parts of Emal 10) and stirred well. Next, heat the reaction vessel and keep the internal temperature at 80°C.
A mixture of 10 parts of BA, 10 parts of EDMA, and 5 parts of EDMA, and a mixture of 0.25 parts of ammonium persulfate and 5 parts of ion-exchanged water were added dropwise over 1 hour to react, and the mixture was maintained at the same temperature for about 1 hour. Then, while maintaining the internal temperature at 80℃,
A mixture of 52 parts of 5T, 10 parts of α-methylstyrene, 2 parts of HAA, and 1 part of DVB, and a mixture of 0.25 parts of ammonium persulfate and 5 parts of ion-exchanged water were added dropwise over 1 hour to react, and the mixture was heated to roughly the same temperature. Hold for 45 minutes.

Thereafter, the mixture was cooled, and 3 parts of 25% aqueous ammonia was added to adjust the pH to 8.6.

The obtained emulsion had a solid content concentration of 48.0% and a viscosity of 15 CPS (B-type rotational viscometer, rotor Nα1,
Rotation speed 6 Orpm, value at 4 degrees 25 degrees C), ptf B
. 6. The average particle diameter was 0.4 μm. Hereinafter, this emulsion will be referred to as (T2).

Examples 1 to 5 and Comparative Examples 1 to 3 Each emulsion (A
-5) ~ (A-8) and (B-1) ~ (B-2) as a binder emulsion VONCOA Ding EC-88
0 (Dainippon Ink Chemical Industry ■ product) and hydroxyethyl cellulose as a thickener, Example 5, Comparative Example 3
The titanium oxide pastes listed in Table 1 were blended as shown in Table 1 and stirred until the viscosity became uniform to form a paint. It was then applied onto a glass plate using a 6 mil applicator, dried for one day at room temperature, and the light transmittance was measured. The results are shown in Table-1. In addition, in order to evaluate storage stability in the presence of basic substances, 14% ammonia water was added to Table 1.
After adding the amount shown in , the particle diameter was measured at 50° C. for 1 month.

The results are also shown in the same table.

(Left below) *1) 70wt% aqueous dispersion of rutile titanium oxide 2)
Pigment volume concentration (v01%) when the solid content of VONCOAT EC-880 and non-film-forming polymer fine particles is 1, and the specific gravity of titanium oxide is 4.2 Book 3) Murakami glossy needle 90'10 Measured value at ° *4) Apply the prepared paint using a 6 mil applicator using a hiding rate test paper (
(manufactured by Nippon Test Panel Industry Co., Ltd.) and heated at 23°C for 1
The diffuse reflectance at 45° 10° was measured for the black background part and the white background part after being left for a day, and calculated using the following formula: Hiding rate = (diffuse reflectance at 45° 10° of the paint film on the black background) / (white 45°10” diffuse reflectance of ground coating>
(JIS-ni-5400) E5) (^-5) ~ (^-8
) and 14% for each 100 copies of (G1) to (G2)
A predetermined amount of ammonia water was added, stirred well, sealed tightly, and left in a constant temperature and humidity chamber at 50°C for 1 month.46) Change in particle size after leaving at 50°C for 1 month ◎: Change in particle size shows a change in volume that is less than twice the initial particle size.

X: Indicates a change in particle size exceeding twice the initial particle size in terms of volume or aggregation.

As shown in Table 1, the composition of the present invention has excellent whiteness, and even when mixed with titanium oxide, the composition does not lose its whiteness as shown in Example 5 and Comparative Example 3. The amount of titanium oxide used can be reduced.

Claims (1)

[Claims] (1) [1] 100 parts by weight of an aqueous binder (based on solid content), [2] (A) 5 to 5 α,β-ethylenically unsaturated carboxylic acids
70 wt%, (meth)acrylic acid alkyl ester having a C_1_-_8 alkyl group 5 to 95 wt%, aromatic vinyl compound 0 to 50 wt%, and other monomers that can be copolymerized with the above components 0 to 50 wt% (ratio (based on the total amount of component (A)) is subjected to emulsion polymerization, and 0.
In the presence of 1 to 30 parts by weight, (B) 2 to 9 wt of α,β-ethylenically unsaturated carboxylic acid
%, 50 to 98 wt% of an aromatic vinyl compound, and 0 to 48 wt% of a monomer that can be copolymerized with these (ratios are based on the total amount of component (B)). Non-film-forming polymer emulsion obtained by
0 parts by weight (based on solid content); [3] A resin composition for an aqueous paint, comprising: [3] pigments if necessary.