JPH07331117A - Aqueous resin composition for coating material - Google Patents

Abstract

PURPOSE:To prepare an aq. resin compsn., for a coating material, which has good storage soln. stability and can impart whether, heat and water resistances, and adhesion by dispersion-polymerizing a vinyl monomer using a polymerization initiator in water or water and a water-soluble org. solvent in the presence of a polyethylene oxide resin as a polymerization dispersion stabilizer. CONSTITUTION:An aq. resin compsn. for a coating material, comprising: (A) 1 to 15 pts.wt. water-soluble, high-mol.wt. compd.; (B) 100 pts.wt. polymer prepd. by dispersion-polymerizing at least one vinyl monomer in water or water and a water-soluble org. solvent in the presence of the component (A) as a dispersion stabilizer; and (C) water or water and a water-soluble org. solvent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to metal, plastic,
It can be used as a coating agent for wood, etc., particularly preferably for cans, aluminum sashes, metal coatings such as pre-coated metal, etc. From the viewpoint of low pollution, resource saving and safety and health, heat resistance, weather resistance, water resistance, etc. The present invention relates to a water-based resin composition for coatings having excellent coating film characteristics.

[0002]

Conventionally, solvent-based or organic solvent-containing water-based coating agents have been used as metal coating agents for cans, aluminum sashes, pre-coated metals, etc. From a perspective,
It is desired to shift to an aqueous system which does not contain a solvent or uses a solvent as little as possible, and various methods have been proposed. For example, (a) a latex type low-solvent coating paint in which a water-soluble resin is combined with a vinyl monomer polymer obtained by emulsion polymerization is disclosed in JP-A-62-12736.
No. 3, and is obtained by polymerizing a monomer containing an alkyl (meth) acrylate as an essential component in the presence of (b) an aqueous dispersion of an ethylenically unsaturated carboxylic acid polymer (a). A water-based coating composition obtained by blending an acrylic copolymer latex, (C) an aqueous dispersion composition comprising a water-soluble acrylic resin, and (D) a thermosetting resin in a hydrophobic dispersion composition is disclosed in Japanese Patent Application Laid-Open No. HEI-5-53242. No. 2,630,34. (B) An aqueous coating composition comprising, as an ionic type, a vinyl monomer polymer obtained by emulsion polymerization and an organic solvent content of 10% by weight is disclosed in JP-A-4-37267.
It is disclosed in Japanese Patent No. α, β-monoethylenically unsaturated carboxylic acid, hydroxyalkyl ester of α, β-ethylenically unsaturated carboxylic acid having a hydroxyl group, N-alkoxymethyl (meth) acrylamide having an alkyl group having 4 or less carbon atoms, and others JP-A-5-279621 discloses a resin composition for an aqueous coating obtained by polymerizing a monomer consisting of the above monomer and then neutralizing it with a base.

[0003]

However, the coating composition of (a) has a problem of compatibility between the acrylic resin latex and the water-soluble resin, and the fluidity of the coating composition is significantly changed with the passage of time. Problem occurs. Further, since it is an aqueous dispersion composition comprising a water-soluble acrylic resin added to the latex of an ethylenically unsaturated carboxylic acid-based polymer or an acrylic-based copolymer, the coating composition may change with time from the viewpoint of compatibility. The problem of viscosity stability of the paint that the fluidity changes remarkably, and the uniformity and durability of the coating film are insufficient. For the coating of (b), the obtained acrylic resin or acrylic styrene resin is neutralized with triethyleneamine or ammonia to adjust the latex, but since the coating is ionic, it is easily soluble in water or water. The durability of the coating film is insufficient because the components that are easily soluble in are dispersed. There is a demand for solving such problems.

[0004]

Therefore, as a result of intensive investigations by the present inventors, an aqueous resin composition for coating obtained by dispersion polymerization using a water-soluble high molecular weight compound as a dispersion stabilizer for polymerization Firstly, the viscosity stability of the paint is excellent, secondly the content of water-soluble organic solvent is low, and the gloss of the coating film is excellent, and thirdly, the durability (water resistance, weather resistance, etc.) of the coating film is excellent. An extremely useful aqueous resin composition for paints is provided.

That is, (A) water-soluble high molecular weight compounds 1 to 1
5 parts by weight, (B) using (A) as a dispersion stabilizer,
In the presence of the resin, 100 parts by weight of a polymer of at least one or more vinyl-based monomers dispersed and polymerized in water or water and a water-soluble organic solvent, and (C) water or water and a water-soluble organic solvent are blended. The above-mentioned object is achieved as a water-based resin composition for coatings, which is characterized by the following.

Furthermore, in the presence of (A) a water-soluble high molecular weight compound, (B) at least one kind of vinyl-based monomer is dispersed in water or water and a water-soluble organic solvent to obtain a water-based resin composition. Since a part of the vinyl-based monomer is graft-polymerized with the water-soluble high molecular weight compound, the coating film has excellent durability and becomes an aqueous resin composition. In particular, a polyethylene oxad-based water-soluble high-molecular weight compound is preferable as a paint because it is excellent as a dispersion stabilizer for the dispersion polymerization of the above vinyl-based monomer and the coating film tends not to absorb moisture.

The present invention will be described in detail below.

The water-soluble high molecular weight compound used in the present invention is one that is soluble in water. More specifically, one condition under which a water-soluble high molecular weight compound is soluble in water as a solvent is that the solute and the solvent have polarities close to each other, that is, the solubility parameter (SP) must be close. SP of water
Since the value is very high as 23.4, its SP value must also be high in order for the polymer to be water-soluble. However, if the SPs are all near, it is not always the case. A close SP value is a necessary condition, not a sufficient condition. In order to be a water-soluble high molecular weight compound, it is important that the crystallinity is weak, that is, the bond between the polymers is weak, in addition to having high SP like water.

Specifically, the water-soluble high molecular weight compound has two modes of being dissolved in water. The first method is neutral like starch, but melts due to weak crystallinity. Methylcellulose, ethylcellulose, hydroxyethylcellulose, ethylcellulose, which is a semi-synthetic product with weakened crystallinity, and synthetic polyvinyl alcohol, polyethylene oxide, polyvinylpyrrolidone,
Polyvinylpyrrolidone copolymer, poly (2-oxazoline) and the like belong to this group. The second mode is a polyelectrolyte such as carboxymethyl cellulose, sodium alginate and sodium acrylate, which is dissolved by the force of sodium ion counterion.

Examples of the water-soluble high molecular weight compound which is the component (A) used in the present invention include polyethylene oxide, polyethylene oxide copolymer system, polyvinylpyrrolidone, polyvinylpyrrolidone copolymer, poly (2).
-Oxazoline) type and the like are used. Preferably 1)
Polyethylene oxide, ethylene oxide content 7
Water-soluble high molecular weight compound having an average molecular weight of 30,000 or more obtained by addition polymerization of alkylene oxide having an amount of 0 to 99.9% by weight, 2) an organic compound having two active hydrogen groups, and an ethylene oxide content rate 70% by weight
Water-soluble high molecular weight compound having an average molecular weight of 30,000 or more obtained by addition polymerization of the above alkylene oxide, 3) alkylene oxide having an ethylene oxide content of 70% by weight or more in an organic compound having two active hydrogen groups Is a reaction product of a polyhydroxyl compound having an average molecular weight of 1,000 or more obtained by addition polymerization with a polycarboxylic acid or a lower alkyl ester thereof, having an ethylene oxide content of 68% by weight or more,
Water-soluble high molecular weight compounds having a degree of polymerization of 4.5 to 21 and an average molecular weight of 30,000 or more can be mentioned.

The alkylene oxide used as a component of the water-soluble high molecular weight compound is, for example, ethylene oxide, propylene oxide, butylene oxide,
Styrene oxide and the like are used, and the amount thereof is 0.05 to 20 with respect to 100 parts by weight of alkylene oxide.
The range of parts by weight is preferable, and the amount of the caustic catalyst such as sodium hydroxide and potassium hydroxide used in the addition polymerization reaction is 0.01 to 100 parts by weight based on 100 parts by weight of the starting material and the alkylene oxide. A range of 1 part by weight is preferred. As a conventional method for synthesizing a polyalkylene oxide-based polymer having an average molecular weight of 20,000 or more, for example, polyethylene oxide is polymerized with ethylene oxide by a special catalyst such as diethylzinc, strontium carbonate, triethylaluminum, etc. Under polymerization conditions, for example, n-hexane, 1,4-dioxane and n-heptane are used as a solvent.

The organic compounds having two active hydrocarbon groups include ethylene glycol, dieethylene glycol, propylene glycol, dipropylene glycol,
1.4-butanediol, 1,6-hexanediol,
Examples include neopentyl glycol, bisphenol A, polyethylene glycol, polypropylene glycol, polytetraethylene glycol and the like. Further, polyvalent carboxylic acids or lower alkyl esters thereof include malonic acid, succinic acid, maleic acid, fumaric acid, adipic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, itaconic acid, or dimer acid, and their monoesters. ester,
Examples thereof include dialkyl esters and carboxylic acid anhydrides.

The amount of the water-soluble high molecular weight compound added is preferably as small as possible in order to prevent deterioration of the durability of the coating film, especially the water resistance. Further, in the aqueous resin composition for paints obtained by dispersion polymerization, from the viewpoint of coatability, it is desirable that the average particle diameter of the fine particles of the polymer of at least one kind of vinyl monomer is 5 μm or less, It is more preferably 2 microns or less, and particularly preferably 1.5 microns or less. If it exceeds 5 microns, the gloss is inferior, which is not preferable. In order to control the average particle size of the fine particles of the vinyl monomer polymer, stirring conditions, the amount of water-soluble solvent added, the amount of oxygen, the average molecular weight of the water-soluble high-molecular weight compound and its solution viscosity, etc. You can choose. The amount of the water-soluble high molecular weight compound added is 1 to 15 parts by weight (the above vinyl-based monomer 1
100 parts by weight), preferably 3 to 9 parts by weight.

The component (B) is the main component of the water-based resin composition for paints, and for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl. (Meth) acrylate, isobutyl (meth) acrylate, n-amyl (meth) acrylate, isoamyl (meth) acrylate, n-hexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, decyl (meth) ) Acrylate, dodecyl (meth) acrylate, lauryl (meth)
Acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, alkyl-substituted phenoxyethyl (meth) acrylate, phenoxydiethyl Ethylene glycol (meth) acrylate, alkylphenol ethylene oxide (meth) acrylate, alkylphenol propylene oxide (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, ethylene glycol (meth) acrylate monophthalate, ethylene glycol (meth) Acrylate Monophthalate Polyester (meth) acrylate such as hydroxyethyl phthalate , Allyl glycidyl ether,
Epoxy compounds such as glycidyl (meth) acrylate and methylglycidyl (meth) acrylate, acid amide compounds such as (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide and maleic acid amide, vinyl chloride , Vinylidene chloride, vinyl acetate, vinyl compounds such as fatty acid vinyl esters, fluorine-containing vinyl monomers such as trifluoro (meth) acrylate, pentadecafluorooctyl (meth) acrylate, γ-methacryloylalkyltrialkoxysilane, γ- Methacryloylalkyldialkoxyalkylsilane, γ-methacryloylalkylalkoxydialkylsilane, trialkoxyvinylsilane, dialkoxyalkylvinylsilane, alkoxydialkylvinylsila Silicon-based vinyl monomer and the like. Aminoalkyl esters of ethylenically unsaturated carboxylic acids such as dialkylaminoalkyl (meth) acrylates, aminoalkylamides of ethylenically unsaturated carboxylic acids such as dialkylaminoalkyl (meth) acrylamides, 2-hiddleoxyethyl (meth) acrylate, 2- Hydroxyl (meth) acrylate such as hydroxypropyl (meth) acrylate, ethylene-based monomers such as ethylene, isobutylene and methacrylonitrile,
Unsaturated diesters such as styrene, α-methylstyrene, alkyl-substituted styrene, alkoxy-substituted styrene, halogen-substituted styrene styrene monomers, 1-vinylnaphthalene, maleic acid diester, fumaric acid diester, itaconic acid diester, citraconic acid diester, etc. Type monomers, 2,3-carbonate propyl (meth) acrylate, 3,4-carbonate butyl (meth) acrylate
G., 4,5-carbone-topentyl (meth) acrylate, 6,7-carbonate hexyl (meth) acrylate, 2,3-carbonate propyl vinyl ether or methyl-2,3-carbonate propyl crotonate. 2-oxo-1,3-dioxolan-4-yl group-containing ethylenically unsaturated monomer, polyolefin-based oligomer, siloxane polysiloxane or the like having a methacryloyl group or an ethylenically unsaturated double bond at the terminal or side chain. Anything is fine.

The plasticizer used in the aqueous resin composition used in the present invention is basically a plasticizer which is difficult to azeotrope with water or an aqueous solvent, is hard to volatilize, and is a polymer obtained from a vinyl monomer. Good compatibility. For example, dibutyl phthalate (abbreviated as DBP), di-2-ethylhexyl phthalate (DOP), diisononyl phthalate (DINP), diisodecyl phthalate (DIDP), diheptyl phthalate (DHP), di-n-octyl phthalate (ND)
OP) butyl benzyl phthalate (BBP), ethyl phthalyl ester such as ethyl phthalyl ethyl glycolate, di-2-ethylhexyl adipate (DOA), aliphatic ester such as dibutyl diglycol adipate (BXA), tripropylene glycol methyl Ether (TP
M), propylene glycol ethers such as dipropylene glycol-n-butyl ether (DPnB), tripropylene glycol-n-butyl ether (TPnB) and propylene glycol phenyl ether (PPh). Preferably, DOP, DINP, DI
DP, DHP and N-DOP are good. The plasticizer may be added according to each form and is not particularly limited. That is, the addition amount of the plasticizer may be selected depending on the coating property, smoothness, flexibility, mechanical properties and the like of the aqueous resin composition for coating. The plasticizer may be added during the dispersion (suspension) polymerization of the vinyl monomer or after the polymerization.
It is preferably added at the time of polymerization in order to prevent adhesion between polymer particles.

The function of the dispersant for polymerization used in the present invention is to allow the fine particles of the polymer obtained from the vinyl monomer of the component (B) to be stably present by dispersion polymerization.

Examples of the solvent used in the present invention include water, alcohols such as methanol, ethanol, propanol and isopropanol (IPA), ethylene such as ethylene glycol methyl ether, ethylene glycol ethyl ether and ethylene glycol butyl ether (EM). Glycol derivative, diethylene glycol methyl ether, diethylene glycol ethyl ether,
Diethylene glycol derivatives such as diethylene glycol butyl ether, propylene glycol methyl ether (PM), propylene glycol ethyl ether, propylene glycol derivatives such as propylene glycol butyl ether, acetic acid ester derivatives such as methyl acetate, ethyl acetate, methyl lactate, ethyl lactate (EL), etc. A water-soluble solvent such as a lactate derivative may be used. It is selected from at least one or more kinds of water or water and a water-soluble solvent. Further, a part of an alcoholic solvent which is hardly soluble in water may be added. When water and a water-soluble solvent are used, the mixing ratio is 100 to 50% by weight of water, 0 to 50% by weight of water-soluble solvent, preferably 95 to 70% by weight of water, 5 to 30% by weight of water-soluble solvent.
Is.

The function of the water-soluble solvent is that, when the water-soluble solvent is present during dispersion polymerization, the particles of the polymer produced are likely to become fine particles, and the dispersion polymerization is likely to proceed smoothly.
Also, there is little adhesion of polymer to the polymerization kettle.

Examples of the polymerization initiator include 2,2'-
Azobis (isobutyronitrile) [AIBN], 2,
2'-azobis (2,4-dimethylvaleronitrile),
Azo compounds such as 2,2′-azobis (isobutylvaleronitrile), peroxides such as tert-butyl hydroperoxide (t-BHPO), benzoyl peroxide, t-butyl peroxide, ammonium persulfate (APS), and peroxides. Water-soluble polymerization initiators such as persulfates such as potassium sulfate (KPS) can be used without particular limitation.
The amount used is 0.0 with respect to 100 parts by weight of the total amount of the monomers.
It is desirable to use 5 to 5 parts by weight. If necessary, the molecular weight of the binder can be controlled by using a chain transfer agent such as tasharidodecyl mercaptan, thioglycolic acid, and α-methylstyrene oligomer.

This reaction depends on the type of polymerization catalyst,
Usually, it can be performed at 40 to 90 ° C. Lower temperatures give higher molecular weight products and higher temperatures give lower molecular weight polymers.

The average weight molecular weight of the vinyl monomer polymer used as the component (B) in the present invention is 10,000 to 100.
10,000, preferably 200,000 to 500,000. If it is less than 10,000, the mechanical strength of the coating film is weak and the durability is insufficient.
If it exceeds 10,000, the leveling property (a phenomenon in which a film is formed at the same time as natural drying) is deteriorated. The glass transition temperature of the polymer as the component (B) is preferably 0 to 200 ° C, more preferably 20 to 170 ° C. If it is less than 0 ° C, the durability is poor, and if it exceeds 200 ° C, the film-forming property is poor. The final polymerization conversion rate of the polymer is 90 to 100 in view of workability, environmental safety, disaster prevention safety and manufacturing safety, particularly from the viewpoint of workability, environmental safety and disaster prevention safety. It is desirable that the content is wt%, particularly 95 to 100 wt%, and more preferably 99 wt% or more. The particle size of the polymer obtained by the present invention can be measured by an electron microscope, a microtrack method, or the like.

As the chain transfer agent, for example, tetrasalt carbon,
Halogen-based hydrocarbons such as chloroform, mercaptans such as n-dodecyl mercaptan, t-dodecyl mercaptan and n-octyl mercaptan, xanthogens such as dimethylxanthogen disulfide, diisopropylpropylxanthogen disulfide, dipentene, tapinoline. And other terpenes, α-methylstyrene dimer
[2,4-diphenyl-4-methyl-1-pentene (a
₁ ), 2,4-diphenyl-4-methyl-pentene (a ₂ ) and at least one of 1,1,3-trimethyl-3-phenylindane (a ₃ ), preferably (a ₁ ) / ( a ₂ ) and / or (a ₃ ) (weight ratio) = 40
~ 100 / 0-60], 9,10-dihydroanthracene, 1,4-dihydronaphthalene, indene, 1,4-
Examples thereof include unsaturated cyclic hydrocarbon compounds such as cyclohexadiene, and unsaturated heterocyclic hydrocarbon compounds such as xanthene and 2,5-dihydrofuran. The amount of chain transfer agent used is 0.005 to 100 parts by weight of vinyl monomer.
It is about 5 parts by weight.

Further, as the pigment used in the present invention, red lead,
Chromate metal salts such as zinc chromate, barium chromate and strontium chromate, zinc phosphate, calcium phosphate, aluminum phosphate, titanium phosphate, silicon phosphate, or phosphorus such as ortho or condensed phosphate of these metals. Rust prevention of acid metal salts, metal salts of zinc molybdate, potassium potassium molybdate, calcium potassium molybdate, etc., metal borate salts of calcium borate, zinc borate, barium borate, barium metaborate, calcium metaborate, etc. Pigment, titanium dioxide,
Known pigments such as inorganic pigments such as carbon black, red iron oxide, precipitated barium sulfate, and organic pigments such as phthalocyanine, benzidine, quinacridone, and azo are used. Further, if necessary, an inorganic filler such as calcium carbonate, silica, alumina, kaolin, clay, diatomaceous earth, mica, aluminum hydroxide, glass powder, magnesium carbonate, talc, etc. The average particle diameter is within the range of, and more preferably 1 to 30 microns. UV absorber, dispersant,
Antifoaming agent, leveling agent, curing agent, cissing inhibitor, anti-skinning agent, antistatic agent, antioxidant, flame retardant, wetting agent such as surfactant, polyamide resin type, organic bentonite type, oxidation Addition of an anti-sagging agent such as polyethylene type can be used. Examples of the curing agent include blocked isocyanates such as hexamethylene isocyanate trimer or emulsion dispersions thereof, known urea resins such as methylated melamine, methylolated melamine, butyrolated melamine, methylurea and butylated urea.

Solvent-based paints of amino resins such as melamine-based resins and guanamine-based resins are usually used by dissolving them in an organic solvent together with alkyd resins, acrylic resins, epoxy resins and the like. It is also possible to use as a water-based resin coating composition by dispersing and polymerizing the vinyl monomer as the component (B) in the presence of a resin, a guanamine-based resin or other amino resin powder. Many water-based resins such as polyester resins, acrylic resins, and epoxy resins are used as water paint resins, but their water resistance is not good.

The aqueous resin composition for paints of the present invention can be applied to metals, plastics, wood, building materials, electrical products, floors of automobiles, vehicles, gasoline tanks, etc. by known means such as roll coating and spraying. . For spray painting, use a Ford Cup # 4 (25 ° C) 12-2
It is preferable that the viscosity is adjusted to 5 seconds.

[0026]

EXAMPLES The present invention will be described more specifically below with reference to examples and comparative examples. In each example, parts and% are by weight in principle.

The resulting aqueous resin composition for paint was applied to a steel sheet using a bar coater so that the dry coating film thickness was 10 to 20 μm, and heat-treated at 120 to 150 ° C. for 30 minutes. With respect to the physical properties of the test piece thus obtained, water resistance, coating property, and storage stability of the water-based resin composition for coating were evaluated. For the water resistance test, immerse in boiling water for 30 minutes and perform a scotch tape peeling test to obtain 1 x 1 m
Among 100 squares of m, the number of squares remaining without peeling is displayed.

(Example 1) 189 g of ion-exchanged water was charged into a 2 l flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a gas introduction tube under a nitrogen gas stream.
While stirring, 21 g of polyethylene oxide resin (average molecular weight: about 200,000 to 300,000) was added thereto to obtain 10% by weight.
An aqueous solution of polyethylene oxide resin was obtained. Next, while adding 498.3 g of ion-exchanged water and replacing the polymerization system with a nitrogen gas flow rate of 1.01 l / min until the initiation of polymerization, 150 g of n-butyl methacrylate, 45 g of methyl methacrylate, and 1,4-butane were added next. Diol monoacrylate 6
0 g, γ-methacryloxypropyltriethoxysilane 45 g, t-dodecyl mercaptan 15 g, isopropyl alcohol 225.8 g, diisononyl phthalate 1
After charging 5 g and 30 g of a 5% aqueous solution in which 1.5 g of ammonium persulfate was dissolved, nitrogen gas was kept flowing for about 1 hour.
The solution in the flask was heated to 60 ° C., and dispersion polymerization was continued for 5 hours. Polymerization temperature 70, 75, 80 ° C to complete the polymerization
Then, the temperature was raised stepwise and the polymerization was continued for 2 hours. The polymerization solution was cooled to room temperature to obtain an aqueous resin composition. The various characteristics are shown in Tables 1 and 2.

[0029]

[Table 1]

[0030]

[Table 2]

(Example 2) A 2 l flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a gas introduction tube was charged with 189 g of ion-exchanged water under a nitrogen gas stream.
While stirring there, polyethylene oxide-based resin (Daiichi Kogyo Seiyaku Co., Paogen PP-15, average molecular weight: about 1
21 g of 0 to 140,000) was added to obtain a 10% by weight aqueous solution of polyethylene oxide resin. Ion-exchanged water (309.3 g) was added to this solution, and nitrogen gas 1.
While replacing the polymerization system at a flow rate of 0 l / min,
8.4 g, stearyl methacrylate 20.7 g, methyl methacrylate 150.3 g, γ-methacryloxypropyltriethoxysilane 90.6 g, t-dodecyl mercaptan 0.5 g, isopropyl alcohol 225.8.
g, 15 g of dibutyl phthalate, and 30 g of a 5% aqueous solution in which 1.5 g of ammonium persulfate was dissolved, and then about 1
The nitrogen gas flow was continued for an hour. The temperature of the solution in the flask is 60 ° C.
The dispersion polymerization was continued for 5 hours. To complete the polymerization,
The polymerization temperature was gradually raised to 70, 75 and 80 ° C. and the polymerization was continued for 2 hours. Cooling the polymerization solution to room temperature,
An aqueous resin composition having a solid content concentration of 30% was obtained. The various characteristics are shown in Tables 1 and 2.

(Examples 3 to 5) The types and amounts of water-soluble high molecular weight compounds, the compounding ratio of vinyl monomers, the types and amounts of polymerization initiators, and the types and amounts of dispersion media are shown in Table 1. Experiments were conducted in the same manner as in Example 1, and various characteristics thereof are shown in Tables 1 and 2.

(Comparative Example 1) Acrylic resin emulsion John Cryl 538 (solid content: 45, particle size: 0.1 micron or less)
%), Water-soluble acrylic resin (solid content 50%, methacrylic acid / methyl acrylate / ethyl methacrylate (15/45/40 copolymer neutralized with dimethylethanolamine) 60 parts, hexyl cellosolve 7 Department,
1 part of butyl cellosolve, 67 parts of ion-exchanged water, and an aqueous varnish in which the above components are well mixed with each other are coated on a steel plate with a roll coater to a film thickness of about 10 microns, and dried to form a coating film. The obtained varnish was about to agglomerate, its viscosity changed with time, and was worse than the solvent-based coating film.

[0034]

According to the resin composition of the present invention, weather resistance,
A coating film having heat resistance, water resistance, good storage solution stability, and excellent mechanical properties such as low-temperature curability, coating state, impact resistance, and bending resistance can be formed. In addition, it has been achieved by the present invention that it has been difficult for water-based resin compositions to combine the above-mentioned various properties.
Further, various additives, for example, color pigments can be easily dispersed, and various properties required for use can be freely modified by mixing various additives and performing dispersion polymerization.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Norikazu Sekida 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Ltd.

Claims (5)

[Claims] (1) 1 to 15 parts by weight of a water-soluble high molecular weight compound (A), (B) using the component (A) as a dispersion stabilizer, dispersed in water or water and a water-soluble organic solvent in the presence of the resin. Polymerized polymer of at least one vinyl monomer 100
A water-based resin composition for paints, characterized in that, by weight, (C) water or water and a water-soluble organic solvent are blended. 2. The water-soluble high molecular weight compound according to claim 1,
A water-based resin composition for coating material, which is at least one of polyethylene oxide and polyvinylpyrrolidone. 3. The water-soluble high molecular weight compound according to claim 1,
The average molecular weight obtained by addition-polymerizing an alkylene oxide having an ethylene oxide content of 70% by weight or more is 3
A water-based resin composition for coatings, which is a water-soluble high-molecular-weight compound of 10,000 or more. 4. The water-soluble high molecular weight compound according to claim 1,
A water-soluble high molecular weight compound having an average molecular weight of 30,000 or more obtained by addition-polymerizing an alkylene oxide having an ethylene oxide content of 70% by weight or more to an organic compound having two active hydrogen groups. Water-based resin composition. 5. The water-soluble high molecular weight compound according to claim 1,
A polyhydroxyl compound having an average molecular weight of 1,000 or more obtained by addition-polymerizing an alkylene oxide having an ethylene oxide content of 70% by weight or more to an organic compound having two active hydrogen groups, and a polyvalent carboxylic acid or a lower alkyl ester thereof. Which is a water-soluble high molecular weight compound having a content of ethylene oxide of 68% by weight or more, a polymerization degree of 4.5 to 21, and an average molecular weight of 30,000 or more. A water-based resin composition for paints.