JPH10316890A - Water-based coating composition and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition excellent in hot water resistance, contamination resistance, elasticity, blocking resistance, weatherability and adherability, and useful for coating cement roofing tiles, etc., by including an aqueous resin emulsion, a specific acetylene-based compound, and an organisilicon compound. SOLUTION: This coating composition is obtained by incorporating (A) 100 pts.wt. of an aqueous resin emulsion such as of vinyl acetate base (the glass transition temperature of the resin being pref. 20-70 deg.C) with (B) pref. 0.1-20 pts.wt. of an acetylene-based compound of the formula [R<1> and R<2> are each H or an alkyl; R<3> is H or a (hydroxyl-substituted) alkyl] such as 3-methyl-1- pentyn-3-ol, and (C) pref. 0.1-20 pts.wt. of an organosilicon compound such as an organopolysiloxane, and furthermore, pref. (D) 0.1-20 pts.wt. of a wax component. This coating composition is pref. applied to the surface of an porous inorganic base material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention is excellent in hot water resistance, stain resistance, elasticity, blocking resistance, weather resistance and adhesion.
The present invention relates to an aqueous coating composition useful for coating cement tiles and the like, a method for producing the same, and a coating method.

[0002]

2. Description of the Related Art In recent years, prefabricated houses have become widespread, and there is a demand for high quality and low cost building materials. In particular, the use of cement tiles has become widespread in place of Japanese tiles and western tiles because of the advantages of workability and manufacturing cost as tiles. Various types of cement tiles, including tiles, are on the market. Cement roof tiles are usually manufactured by mixing cement, hard aggregate, fibrous reinforcing material, water, etc., and then forming and press-molding, then curing and hardening the cement. Such a cement roof tile can be used as it is, but in order to improve the appearance and prevent weathering of the cement,
It is often used by coloring its surface.

Japanese Unexamined Patent Publication (Kokai) No. 62-27387 discloses a coating for slate, which is a styrene-acrylic resin emulsion containing n-butyl methacrylate, as a cement topcoat, using an aqueous resin having a glass transition temperature of 70 ° C. or higher as a binder. A resin composition is disclosed, which imparts coating elasticity to a paint by including n-butyl methacrylate. This top coating has excellent blocking resistance because the glass transition temperature of the resin is as high as 70 ° C. or higher. However, the elasticity of the coating film is low, and it is difficult to follow minute cracks generated in the cement base material. Further, when the glass transition temperature of the top coating material is set to less than 70 ° C. or a plasticizer or the like is included to improve the crack followability, blocking resistance is reduced, and contaminants adhere to the surface by natural exposure and are easily stained.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an aqueous coating composition having excellent blocking resistance and stain resistance even when the resin constituting the aqueous resin emulsion has a low glass transition temperature, and a method for producing the same. Is to provide. Another object of the present invention is to provide a water-based coating composition having improved properties of the coating film as well as the above-mentioned properties, and having a high followability to cracks formed on a substrate, and a method for producing the same. Still another object of the present invention is to provide high weather resistance,
An object of the present invention is to provide an aqueous coating composition useful for forming a coating film having hot water resistance and adhesion, and a method for producing the same. Another object of the present invention is to provide a coating method useful for forming a coating film having the above-mentioned properties.

[0005]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, have found that an aqueous resin emulsion contains an acetylene compound and a silicone compound having a hydroxyl group and, if necessary, a wax. It has been found that the addition of the components enables the formation of a coating film having a high ability to follow cracks formed on the substrate and having significantly improved blocking resistance and stain resistance, thereby completing the present invention. That is, the aqueous coating composition of the present invention (that is, a resin composition for an aqueous coating) comprises (A) an aqueous resin emulsion, (B) an acetylene-based compound represented by the following formula (1) or a derivative thereof (hereinafter, simply referred to as Acetylene compounds) and (C) organosilicon compounds.

[0006]

Embedded image (Wherein, R ¹ and R ² are the same or different and each represent a hydrogen atom, a linear or branched alkyl group, and R ³ represents a hydrogen atom, an alkyl group which may have a hydroxyl group. The glass transition temperature of the resin of the aqueous resin emulsion (A) is, for example, about 20 to 70 ° C., and the acetylene-based compound or its derivative (B) includes a compound having a 1,4-butynediol skeleton or The alkylene oxide adduct and the like are included. The organosilicon compound (C) may be an organopolysiloxane which may be modified, a hydrolytic condensable silane compound, or the like. The aqueous coating composition may further include a wax component (D). The method of the present invention includes a method of producing an aqueous coating composition by mixing an aqueous resin emulsion (A), the acetylene compound (B) and the organosilicon compound (C), A method of coating with a coating composition is also included.

[0007] In the present specification, "paint composition"
The term is used synonymously with not only paints but also coating agents that widely cover base materials. "Crack followability" means the degree of cracks formed in a coating film when a crack occurs in the base material and distortion occurs, and is one index of the followability to the distortion caused by crack generation and the elasticity of the coating film. Used as The glass transition temperature is determined by the following formula (i):
olsky). 1 / Tg = (Wa / Tga) + (Wb / Tgb) +... (I) (where Tg is the glass transition temperature (K) of the copolymer, Tg
a is the glass transition temperature (K) of the homopolymer of monomer a,
Tgb is the glass transition temperature (K) of the homopolymer of monomer b, Wa is the weight fraction of monomer a, and Wb is the weight fraction of monomer b.)

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION

[Aqueous resin emulsion (A)] The aqueous resin emulsion (A) is not particularly limited, and a conventional aqueous resin emulsion can be used. For example, (A1) vinyl acetate emulsion, (A2) (meth) acrylic emulsion ,
Examples thereof include (A3) a styrene-based emulsion, (A4) a halogen-containing resin emulsion, (A5) an emulsion containing a thermosetting resin or a silicon resin, and (A6) a complex emulsion obtained by complexing a plurality of resin components. The aqueous resin emulsion (A) can be used alone or in combination of two or more.

(A1) A vinyl acetate emulsion is a vinyl acetate resin such as polyvinyl acetate, a copolymer of vinyl acetate and a copolymerizable monomer [for example, ethylene-vinyl acetate copolymer, ethylene- Vinyl acetate-vinyl chloride copolymer, vinyl acetate- (meth) acrylate copolymer, vinyl acetate and vinyl ester (for example, Veova such as vinyl propionate, vinyl caprylate, vinyl versatate, etc.) And vinyl acetate-maleic acid ester copolymers). These vinyl acetate emulsions can be used alone or in combination of two or more.

Preferred vinyl acetate emulsions include ethylene-vinyl acetate copolymer, vinyl acetate- (meth) acrylate copolymer, vinyl acetate-veova (vinyl versatate, etc.) copolymer and the like. Emulsions.

(A2) (meth) acrylic emulsion
Is a (meth) acrylic resin, for example, (meth) acrylic
Homoester or copolymer of poly (meth) acrylate
Luic acid C _1-10Alkyl ester, (meth) acrylic acid C
_1-10Alkyl ester- (meth) acrylic acid copolymer,
Methyl methacrylate-acrylic acid C_1-10Alkyl esthetic
Copolymer, methyl methacrylate-acrylic acid C_1-10A
Alkyl ester- (meth) acrylic acid copolymer],
Copolymerization of (meth) acrylate and copolymerizable monomer
Coalesce [for example, (meth) acrylate-styrene
Copolymer etc.]. Preferred (meth) a
Krill emulsions contain (meth) acrylate ester
(Meth) acrylic acid ester
Emulsions containing styrene copolymers etc. are included.
The polymers of these emulsions include (meth) acrylic acid
Carboxyl group or its salt is introduced by copolymerization with
You may.

(A3) A styrene-based emulsion is, for example, a copolymer of an aromatic vinyl compound and a copolymerizable monomer [for example, styrene- (meth) acrylate copolymer, styrene- (meth) acrylic Acid ester- (meth) acrylic acid copolymer, styrene-butadiene copolymer, styrene-acrylonitrile copolymer, styrene-
Butadiene-acrylonitrile copolymer). Preferred styrene-based emulsions include styrene- (meth) acrylate copolymers, styrene-acrylonitrile copolymers, and the like. These polymers have a carboxyl group or a methacrylate by copolymerization with (meth) acrylic acid or the like. The salt may be introduced.

(A4) The halogen-containing resin emulsion is
For example, homo- or copolymers of halogen-containing vinyl compounds (polychloroprene, polyvinyl chloride, polyvinylidene chloride, vinyl chloride-vinylidene chloride copolymer, etc.), copolymers of halogen-containing vinyl compounds and copolymerizable monomers Copolymers (for example, vinyl chloride-vinyl acetate copolymer, vinylidene chloride-vinyl acetate copolymer, vinylidene chloride- (meth) acrylic acid copolymer, vinylidene chloride- (meth) acrylate copolymer, vinylidene chloride- Acrylonitrile copolymer, etc.], and halogen-containing resins such as polychloroprene, chlorinated polyolefins (eg, chlorinated polyethylene, chlorinated polypropylene), and fluororesins. Emulsions include, for example, vinyl chloride- Meth) vinyl chloride resins such as acrylic acid ester copolymer, vinylidene chloride - (meth)
Emulsions containing vinylidene chloride resins such as acrylate copolymers, chlorinated polyolefins such as chlorinated polyethylene and chlorinated polypropylene, and fluororesins are included.

(A5) Examples of the emulsion containing a thermosetting resin or a silicon resin include an emulsion containing a thermosetting resin such as an epoxy resin and a urethane resin, and a silicone resin emulsion.

(A6) The complexed emulsion includes, for example, a mixture of the aqueous resin emulsions of the above (A1) to (A5), a crosslinking agent (for example, an amino resin such as a urea resin, a melamine resin or a benzoguanamine resin, a polyisocyanate compound). , Epoxy compounds, polyethyleneimine, etc.)
And a resin emulsion having a reactive functional group (eg, a hydroxyl group, a carboxyl group, an amino group, a glycidyl group, a methylol group, an alkoxymethyl group, etc.), and a plurality of resin polymers are blocked or grafted. Examples thereof include a polymerized resin emulsion. In the complex emulsion (A6), α, β-ethylenically unsaturated groups (for example, vinyl group, isopropenyl group, allyl group, (meth)
An aqueous resin emulsion having a core / shell structure obtained by polymerizing a monomer having a polymerizable unsaturated group such as an acryloyl group) and an aqueous resin emulsion having a microdomain structure are also included. In addition, complex emulsion (A6)
A slash “/” is added between the components that constitute to indicate the type of composite emulsion.

Preferred complexed emulsions (A6) include:
For example, (meth) acrylic resin / epoxy resin emulsion, (meth) acrylic resin / urethane resin emulsion, (meth) acrylic resin / silicone resin emulsion, (meth) acrylic resin / fluororesin emulsion, (Meth) acrylic resin / melamine resin emulsion, (meth) acrylic silicone resin emulsion and the like are included.

Particularly preferred aqueous resin emulsion (A)
The (meth) acrylic emulsion (A2) [for example, a homo- or copolymer of (meth) acrylic acid ester,
(Meth) acrylic acid ester- (meth) acrylic acid copolymer, (meth) acrylic acid ester-styrene copolymer, (meth) acrylic acid ester-styrene- (meth)
Acrylic acid copolymer etc.], complex emulsion (A6)
[For example, (meth) acrylic resin / urethane resin emulsion, (meth) acrylic resin / silicone resin emulsion, (meth) acrylic resin / melamine resin emulsion, (meth) acrylic silicone resin emulsion, etc.] included.

Among the aqueous resin emulsions (A), an aqueous resin emulsion excellent in water resistance, alkali resistance, freeze-thaw adhesion, weather resistance and the like is preferably used. From the viewpoints of adhesion and economy, preferred aqueous resin emulsions (A) include poly (meth) acrylates,
(Meth) acrylic ester-styrene copolymer, (meth) acrylic resin / silicone resin emulsion.

The aqueous resin emulsions (A1) to (A4)
Is a conventional method, for example, an ethylenically unsaturated compound,
It can be prepared by a method of emulsion polymerization in the presence or absence of an emulsifier such as a surfactant. Examples of the ethylenically unsaturated compound include, for example, vinyl esters (for example, vinyl acetate, vinyl propionate, vinyl caprylate, vinyl versatate, etc.) and (meth) acrylate according to the type of the resin constituting the emulsion. [For example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) ) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, C _1-18 alkyl (meth) acrylate and dodecyl (meth) acrylate, stearyl (meth) acrylate, consequent Cycloalkyl (meth) acrylates such as hexyl (meth) acrylate, aryl (meth) acrylates such as phenyl (meth) acrylate, aralkyl (meth) acrylates such as benzyl (meth) acrylate, etc.), and aromatic vinyl compounds (eg, styrene , Α
-Methylstyrene, vinyltoluene, etc.), ethylenically unsaturated compounds having a hydroxyl group [for example, hydroxy C _2-6 such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate)
Alkyl (meth) acrylates, etc.], ethylenically unsaturated compounds having a glycidyl group [eg, glycidyl (meth) acrylates, etc.], halogen-containing vinyl compounds (eg, vinyl chloride, vinylidene chloride, etc.), acidic monomers [eg, Ethylenically unsaturated aliphatic monocarboxylic acids such as (meth) acrylic acid and crotonic acid; and ethylenically unsaturated aliphatic dicarboxylic acids such as itaconic acid, maleic acid and fumaric acid or derivatives thereof (for example, itaconic acid monoester, maleic acid) Ethylenically unsaturated carboxylic acids such as unsaturated dicarboxylic acid monoesters such as acid monoesters and acid anhydrides; ethylenically unsaturated monosulfonic acids such as vinyl sulfonic acid and styrene sulfonic acid; and derivatives thereof (for example, vinyl sulfone). Acid sodium salt, styrenesulfonic acid sodium salt Unsalted sulfonic acid or a salt thereof), etc.], olefinic monomers (e.g., ethylene,
Propylene, etc.).

If necessary, the ethylenically unsaturated compound may be replaced with another monomer such as an unsaturated dicarboxylic acid diester (eg, diethyl fumarate, dibutyl fumarate, dioctyl fumarate, di (2-ethylhexyl)).
Fumaric acid diesters such as fumarate, and corresponding maleic acid diesters), (meth) acrylamide, hydroxyalkyl (meth) acrylamide [eg, N-methylol (meth) acrylamide and the like],
Alkoxymethyl (meth) acrylamide [for example, N
-Methoxymethyl (meth) acrylamide, N-ethoxymethyl (meth) acrylamide, etc.], mono- or dialkylamino-alkyl (meth) acrylate [eg, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, etc.], diacetone You may use together with (meth) acrylamide etc.

(Meth) acrylic polymer emulsion,
(Meth) acrylate-styrene copolymer emulsion
John, a preferred set of ethylenically unsaturated compounds
As the combination, for example, the glass transition temperature of the homopolymer
50 ° C or more (for example, 50 to 130 ° C, preferably 7 ° C).
0-130 ° C.) hard monomer and homopolymer
Transition temperature of 20 ° C or less (for example, -100 to 20 ° C,
(Preferably around -100 to 0 ° C.)
Can be exemplified. The hard monomer includes, for example, meta
Methacrylates such as methyl acrylate and t-butyl methacrylate
Crylic acid C_1-4Contains alkyl esters, styrene, etc.
Soft monomers include, for example, ethyl acrylate,
Such as butyl acrylate and 2-ethylhexyl acrylate;
Crylic acid C _2-10Alkyl esters and the like.

The ratio of the hard monomer to the soft monomer can be in a wide range, for example, the former / latter = 10/90 to 90/10
(Weight ratio), preferably in the range of about 25/75 to 75/25 (weight ratio).

In order to improve the adhesion, water resistance and flexibility of the coating film, an ethylenically unsaturated compound having a crosslinkable functional group such as a glycidyl group or an N-methylol group may be used.

In the emulsion polymerization, for example, a surfactant such as an anionic surfactant or a nonionic surfactant, or an emulsifier such as a protective colloid such as polyvinyl alcohol or a water-soluble polymer may be used. The polymerization can be carried out using a water-soluble polymerization initiator (for example, a persulfate such as potassium persulfate or ammonium persulfate, hydrogen peroxide, or the like). Further, the aqueous resin emulsion (A) may be a soap-free emulsion containing no surfactant. The soap-free emulsion is, for example, a method of solution-polymerizing a polymerizable monomer containing an acidic monomer [(meth) acrylic acid or the like] and emulsion-polymerizing the resulting hydrophilic oligomer or polymer as a seed in an aqueous system.
It can be obtained by, for example, a method of emulsion polymerization of an acidic monomer together with another polymerizable monomer.

The pH of the aqueous resin emulsion (A) can be selected from a range that does not impair the stability of the coating, for example, a range of about 5 to 10, and is usually about 7 to about 10 to about neutral to alkaline. .

The glass transition temperature and the molecular weight of the resin constituting the aqueous resin emulsion (A) can be appropriately selected according to the properties of the substrate and the like and the coating conditions within a range that does not impair the performance of the coating film. The glass transition temperature of the resin is about 20 to 70 ° C. (for example, 20 to 69 ° C.) in order to enhance the stain resistance.
In particular, in order to enhance the blocking resistance, 30 to 70 ° C.
(For example, 30 to 69 ° C.), particularly about 40 to 70 ° C. (for example, 50 to 70 ° C.).

The molecular weight (weight average molecular weight) of the resin constituting the aqueous resin emulsion (A) is, for example, 1 × 10 ⁴
５０50 × 10 ⁴ , preferably 2 × 10 ⁴ -30 × 10 ⁴
(4 × 10 ⁴ to 30 × 10 ⁴ ), more preferably 5 ×
It can be selected from a range of about 10 ^{4 to} 20 × 10 ⁴ .

The average particle size of the polymer particles of the aqueous resin emulsion (A) is within a range that does not impair the dispersion stability, stain resistance, adhesion, etc., for example, 0.01 to 5 μm, preferably 0.01 to 2 μm. More preferably, 0.01 to 1
It can be selected from about μm.

The coating resin composition of the present invention composed of such an aqueous resin emulsion (A) contains both components of an acetylene compound (B) and an organosilicon compound (C).

[Acetylene Compound (B)] As the acetylene compound (B), the compound represented by the above formula (1) can be used. In the formula (1), examples of the alkyl group include straight-chain or branched-chain C such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s-butyl, t-butyl, pentyl, neopentyl, and hexyl. Includes _1-10 alkyl groups. Usually R ¹
Is, for example, a hydrogen atom or a C _1-2 alkyl group (especially a methyl group), and R ² is, for example, a linear or branched C
_1-10 alkyl group (preferably C _1-6 alkyl group, especially C
_1-4 alkyl group).

R ³ is a hydrogen atom, a linear or branched C 3
_It may be a linear or branched C _1-10 alkyl group having a _1-10 alkyl group or a hydroxyl group. In the alkyl group having a hydroxyl group, the substitution position of the hydroxyl group is not particularly limited, but is usually substituted at the 1-position of the alkyl group and has an acetylene glycol unit (that is, a 1,4-butynediol skeleton). have). Examples of the alkyl group having a hydroxyl group include, for example, hydroxymethyl, 1-hydroxyethyl,
Hydroxypropyl, 1-hydroxy-1-methylpropyl, 1-hydroxy-n-butyl, 1-hydroxy-
1-hydroxy-C _1-10 alkyl groups (preferably 1-hydroxy-C _2-6 alkyl groups) such as 1-methyl-n-butyl and 1-hydroxy-1,3-dimethyl-n-butyl groups. Can be illustrated.

Specific examples of the acetylenic compound (B) include, for example, 3-methyl-1-pentyn-3-ol,
3,5-dimethyl-1-hexyn-3-ol, 3,6
-Dimethyl-4-octyne-3,6-diol, 2,
4,7,9-tetramethyl-5-decyne-4,7-diol and the like can be exemplified. The acetylene compound (B) also includes a derivative thereof (especially an acetylene compound having an oxyalkylene unit in which a C _2-4 alkylene oxide is added to a hydroxyl group of the acetylene compound (B)). Preferred alkylene oxides include ethylene oxide and / or propylene oxide, especially at least ethylene oxide. Specific examples of the derivative include, for example, 3-methyl-1-pentyne-3
-(Mono or polyoxyethylene) ether units, 3,
5-dimethyl-1-hexyne-3- (mono or polyoxyethylene) ether unit, 3,6-dimethyl-4-octyne-3,6-di (mono or polyoxyethylene) ether unit, 2,4,7 , 9-tetramethyl-5-decyne-4,7-di (mono- or polyoxyethylene) ether-containing monool or diol. The average total added mole number of the alkylene oxide can be selected, for example, from a range of about 1 to 100, preferably about 1 to 50, and more preferably about 1 to 30 (particularly about 2 to 20).

Preferred examples of the acetylenic compound (B) include, for example, compounds represented by the following formula (1a).

[0034]

Embedded image (Wherein, R ^3a and R ^3b are the same or different and each represent a hydrogen atom, a linear or branched alkyl group, and R ^4a and R ^4b are the same or different and are a C _2-4 alkylene group. Wherein n and m are each independently an integer of 0 or greater than 1. R ¹ and R ² are the same as defined above.) The alkyl groups of R ^3a and R ^3b include the same as defined above for R ¹ and R ² . Includes alkyl groups. As the C _2-4 alkylene group,
For example, it contains ethylene, propylene, butylene, etc., and is preferably an ethylene group. The coefficients m and n corresponding to the number of moles of the alkylene oxide added are, for example, m + n = 0 to 100 (for example, 2 to 100), preferably 0 to 50 (for example, 2 to 50), and more preferably 0 to 30 ( For example, it can be selected from a range of about 2 to 30), and usually m + n = about 2 to 20.

The amount of the acetylene compound (B) used is, for example, 100% of the resin solid content of the aqueous resin emulsion (A).
0.1 to 20 parts by weight, preferably 0.5 part by weight
It is about 10 to 10 parts by weight, more preferably about 0.5 to 7 parts by weight (for example, 1 to 5 parts by weight). The acetylene-based compound (B) can improve properties such as coating film elasticity (crack following property), weather resistance and hot water resistance even in a small amount.

[Organosilicon compound (C)] The organosilicon compound (C) includes organopolysiloxanes (silicone compounds) which may be modified, and hydrolytic condensable silane compounds. The organosilicon compound (C) can be used alone or in combination of two or more.

The silicone compound is usually represented by the following formula (2)

[0038]

Embedded image Wherein R ^5a , R ^5b and R ^6a are the same or different,
An alkyl group (a C _1-4 alkyl group such as a methyl group or an ethyl group), an aryl group (such as a phenyl group), an aralkyl group (such as a benzyl group), and R ^6b represents an alkylene group, an oxy C _2-4 alkylene group or And a polyoxy C _2-4 alkylene group. Z represents a hydroxyl group, an epoxy group, an amino group, or a carboxyl group. Z may be different depending on y. x is an integer of 1 or more; y is 0 or an integer of 1 or more], for example, an organopolysiloxane, a polyether-modified organopolysiloxane, an epoxy-modified organopolysiloxane, an amino-modified organopolysiloxane. Examples include polysiloxane, alcohol-modified organopolysiloxane, carboxyl-modified organopolysiloxane, and other modified organopolysiloxanes.

In the compound represented by the formula (2),
Desirable R ^5a , R ^5b and R ^6a are a methyl group, a phenyl group and a benzyl group (particularly a methyl group). The alkylene group represented by R ^6b includes a C _1-6 alkylene group (such as an ethylene group), an oxy C _2-4 alkylene group (such as an oxyethylene group) or a polyoxy C _2-4 alkylene group (such as a polyoxyethylene group). Is included. The addition mole number of C _2-4 alkylene oxide (especially ethylene oxide) corresponding to the oxyalkylene unit is, for example, about 1 to 100 (preferably 1 to 50, more preferably 2 to 30).

Examples of the organopolysiloxanes (silicone compounds) include dimethylpolysiloxane, diphenylpolysiloxane, methylphenylpolysiloxane, methylbenzylpolysiloxane, polyether-modified silicone (such as polyether-modified dimethylpolysiloxane),
Epoxy-modified silicone (such as epoxy-modified dimethylpolysiloxane), amino-modified silicone (such as amino-modified dimethylpolysiloxane), hydroxyl-modified silicone (such as hydroxyl-modified dimethylpolysiloxane), carboxyl-modified silicone (such as carboxyl-modified dimethylpolysiloxane), and fluorine-modified Silicone (fluorine-modified dimethylpolysiloxane, etc.), alkyl aralkyl polyether-modified silicone (alkyl aralkyl polyether-modified dimethylpolysiloxane, etc.), epoxy polyether-modified silicone (epoxy polyether-modified dimethylpolysiloxane, etc.)
And the like.

The hydrolysis-condensable silane compound includes an alkoxy group-containing silane compound and a halogen-containing silane compound. Examples of the hydrolyzable alkoxy group-containing silane compound include compounds having a vinyl group such as vinyltrimethoxysilane, vinyltriethoxysilane, and vinyltris (2-methoxyethoxy) silane; compounds having an aryl group such as phenyltrimethoxysilane A compound having an alkyl group such as methyltrimethoxysilane and ethyltriethoxysilane; having a (meth) acryloyl group such as 2- (meth) acryloyloxyethyltrimethoxysilane and 3- (meth) acryloyloxypropyltrimethoxysilane Compound; 2-
Compounds having an epoxy group such as (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2-glycidyloxyethyltrimethoxysilane, 3-glycidyloxypropyltrimethoxysilane; 2-aminoethyltrimethoxysilane, 2-aminoethyl Triethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3- [N- (2-aminoethyl) amino] propyltrimethoxysilane,
Compounds having an amino group such as-[N- (2-aminoethyl) amino] propylmethyldimethoxysilane, 3- (N-phenylamino) propyltrimethoxysilane;
Silane compounds having a mercapto group such as 2-mercaptoethyltrimethoxysilane and 3-mercaptopropyltriethoxysilane; and compounds having a halogen atom such as 2-chloroethyltrimethoxysilane and 3-chloropropyltrimethoxysilane. . The hydrolyzable halogen-containing silane compound includes a compound corresponding to the alkoxy group-containing silane compound (for example, vinyltrichlorosilane).

The amount of the organosilicon compound (C) used is, for example, 0.1 to 20 parts by weight, preferably 0.5 to 20 parts by weight, per 100 parts by weight of the resin solid content of the aqueous resin emulsion (A).
It can be selected from a range of about 15 parts by weight, more preferably about 0.5 to 10 parts by weight, and usually about 0.5 to 12 parts by weight. Even in a small amount, the organosilicon compound (C) can improve properties such as blocking resistance, stain resistance (water repellency), and adhesion (tape releasability) of the coating film.

[Wax (D)] The coating resin composition of the present invention may contain a wax component in order to improve the blocking resistance, scratch resistance, stain resistance and water repellency of the coating film. The type of the wax component (D) is not particularly limited. For example, mineral oil-based wax (paraffin wax,
Natural wax such as microcrystalline wax, montan wax, etc., vegetable wax (carnauba wax, candelilla wax, etc.), synthetic wax (ethylene low polymer synthetic wax, polyethylene wax, polyethylene-paraffin wax, etc.), fat and oil synthetic wax And the like. The wax (C) can be used alone or in combination of two or more.

The amount of the wax (D) used is 0.1 to 100 parts by weight of the resin solid content of the aqueous resin emulsion (A).
1 to 20 parts by weight, preferably 0.5 to 15 parts by weight, more preferably 1 to 10 parts by weight (for example, 1 to 7 parts by weight)
You can choose from a range of degrees. The melting point of the wax (D) is, for example, 30 ° C. or more (for example, 30 to 150 ° C.).
° C), preferably 50 ° C or higher (for example, 50 to 120 ° C).
° C).

[Other Additives] If necessary, the resin composition for a coating material of the present invention may be, for example, a coloring pigment (for example, an organic pigment or an inorganic pigment), an extender pigment (for example, talc,
Clay, calcium carbonate, etc.), gloss modifiers (eg,
Silica fine powder), pigment dispersant (eg, polycarboxylate), wetting agent (eg, nonionic surfactant), neutralizer, thickener, preservative, defoamer, ultraviolet stabilizer, UV absorbers, antioxidants, organic solvents (e.g., alcohols such as ethanol and isopropanol, cellosolves, carbitols, aliphatic, alicyclic or aromatic hydrocarbons, esters such as ethyl acetate, acetone,
Additives such as ketones such as methyl ethyl ketone, ethers, etc.), plasticizers, antifreezing agents (eg, ethylene glycol, propylene glycol, polyethylene glycol, etc.) may be contained.

The resin composition for a coating material of the present invention can be prepared by a conventional method, for example, the above-mentioned aqueous resin emulsion (A), acetylene compound (B), organosilicon compound (C) and, if necessary, wax ( And D).

The resin composition for water-based paint of the present invention is useful as a coating agent for coating various substrates (eg, wood, paper, metal, plastic, ceramics, etc.). In particular, since it has excellent crack followability and blocking resistance, it is useful for coating a porous substrate (in particular, an inorganic substrate in which a defect such as a crack is likely to be formed). As the porous substrate, for example, wood,
In addition to organic base materials such as paper and felt, examples thereof include cement products (cement tile, cement block, slate, etc.), sintered products (brick, brick block, unglazed product, etc.), and gypsum products (gypsum board, etc.). Preferred substrates include cement products such as cement roof tiles.

The amount of coating with the resin composition for water-based paints can be appropriately selected according to the type of the base material.
μm, preferably in the range of about 5 to 50 μm. Various methods such as a conventional method, dipping, roller coating, and spray coating can be employed for coating.

[0049]

According to the present invention, even if the glass transition temperature of the resin constituting the aqueous resin emulsion is low, blocking resistance and stain resistance can be greatly improved. Further, the coating film elasticity of the water-based coating composition can be improved, and the crack followability can be improved. Further, a coating film having high weather resistance, hot water resistance and adhesion can be formed.

[0050]

EXAMPLES The present invention will be described below in more detail with reference to Examples, but the present invention is not limited to these Examples. Example 1 In a glass flask equipped with a stirrer and a condenser,
300 parts by weight of distilled water and 5 parts by weight of sodium lauryl sulfate were added and stirred to dissolve sodium lauryl sulfate, and then the temperature was raised to 80 ° C. Thereafter, 1 part by weight of sodium persulfate was added, and a mixed solution of 240 parts by weight of methyl methacrylate, 60 parts by weight of butyl acrylate, and 3 parts by weight of acrylic acid was added dropwise over 3 hours, polymerized, and cooled. The emulsion of the polymer was adjusted to 30 ° C., and 3 parts by weight of 25% by weight aqueous ammonia was added thereto to obtain an acrylic resin emulsion having a solid content of 50% by weight (hereinafter referred to as “emulsion (A)”). . This emulsion (A)
Glass transition temperature 60 ° C (calculated value), average particle size 0.12
μm, and the weight average molecular weight was 9 × 10 ⁴ . 2 parts per 100 parts by weight of the acrylic resin emulsion solids
4 parts by weight of a 50% by weight solution of 4,7,9-tetramethyl-5-decyne-4,7-diol (hereinafter, referred to as an acetylene-based compound) in ethylene glycol (solids weight of acetylene-based compound: 2 parts by weight) Dimethylpolysiloxane (viscosity: 350 centipoise; hereinafter, referred to as a silicone compound) emulsified with a nonionic surfactant in an amount of 5 parts by weight based on the solid content of the silicone compound, 5 parts by weight of iron oxide-based red pigment, silicone-based An aqueous coating composition was prepared by mixing 0.1 parts by weight of an antifoaming agent, 3 parts by weight of butyl cellosolve, 0.2 parts by weight of a hydroxyethylcellulose-based thickener, and 0.1 parts by weight of a preservative.

Examples 2 to 6, Comparative Examples 1 and 2 An aqueous coating composition was prepared in the same manner as in Example 1 except that the compositions shown in Table 1 were used.

The aqueous coating compositions obtained in the above Examples and Comparative Examples were spray-coated on a cement molding plate (flat slate) heated to 50 ° C. in advance so as to have a dry thickness of 40 μm. When the following properties, blocking resistance, stain resistance, weather resistance, hot water resistance, and adhesion were examined by performing the following tests, the results shown in Table 1 were obtained.

(1) Crack Following Property The coated plate is heated to 120 ° C., sprayed with water at an elevated temperature, cooled to room temperature, and further frozen for 1 hour in a -20 ° C. thermostat. After repeating this 200 times, the presence or absence of fine cracks generated on the surface of the coating film is observed with a 25-times magnifying glass. The evaluation criteria are as follows.

◎: Fine cracks are not generated. 微細: Fine cracks are slightly generated. ：: Fine cracks are slightly generated. X: Fine cracks are frequently generated. (2) Blocking Resistance The cloth is heated while the coated plate is heated to 40 ° C. 2 kg / cm
After pressing for ² days, the pressure is released, and the cloth is peeled off and evaluated. The evaluation criteria are as follows.

：: no resistance ：: slight resistance 少 し: slight resistance ×: significant resistance (3) Stain resistance 1% by weight of aqueous black ink and 5% by weight of calcium carbonate
1 ml of a mixed aqueous dispersion containing the above was dropped on the surface of the coated plate, left for 1 hour, wiped off with a dry filter paper, and the contamination of the coating film surface was evaluated according to the following criteria.

：: No contamination ○: Slight contamination △: Slight contamination ×: Remarkable contamination (4) Weather resistance Using an accelerated weather resistance tester (Metal Weather, manufactured by Daipla Wintes Co., Ltd.) 500 hours (equivalent to 5000 hours of irradiation with a sunshine weather meter), and evaluated according to the following criteria.

◎: No discoloration and gloss finish ○: Very slight discoloration and gloss finish △: Slight discoloration and gloss finish ×: Remarkable discoloration and gloss finish (5) Hot water resistance After immersion in hot water of 1 ° C. for 1 hour, the presence or absence of blisters and the whitening and discoloration state are evaluated. The evaluation criteria are as follows.

◎: No blister and whitening discoloration ○: No blister, but slight whitening and discoloration Δ: Some blisters and slight whitening and discoloration ×: Blister and whitening and discoloration are remarkable (6) Adhesiveness Suddenly peel off the cloth adhesive tape attached to the membrane,
The peeling area of the coating film is evaluated based on the following criteria.

◎: No peeling ：: Peeling area is less than 5% Δ: Peeling area is 5 to 10% ×: Peeling area is 20% or more

[0060]

[Table 1] As is clear from Table 1, the coating composition of the present invention is excellent in crack followability, blocking resistance, stain resistance, weather resistance, hot water resistance, and adhesion.

Claims (10)

[Claims] 1. An aqueous resin emulsion (A) having the following formula (1): (Wherein, R ¹ and R ² are the same or different and each represent a hydrogen atom, a linear or branched alkyl group, and R ³ represents a hydrogen atom, an alkyl group which may have a hydroxyl group. (B) an acetylenic compound represented by () and (C)
An aqueous coating composition comprising an organosilicon compound. 2. The aqueous coating composition according to claim 1, wherein the resin of the aqueous resin emulsion (A) has a glass transition temperature of 20 to 70 ° C. 3. An acetylene compound (B) represented by the following formula (1)
The aqueous coating composition according to claim 1, which is represented by a). Embedded image (Wherein, R ^3a and R ^3b are the same or different and each represent a hydrogen atom, a linear or branched alkyl group, and R ^4a and R ^4b are the same or different and are a C _2-4 alkylene group. Wherein n and m are independently 0 or an integer of 1 or more. R ¹ and R ² are the same as described above. 4. The aqueous coating composition according to claim 1, wherein the organosilicon compound (C) is an optionally modified organopolysiloxane or a hydrolytic condensable silane compound. 5. The organosilicon compound (C) is selected from an organopolysiloxane, a polyether-modified organopolysiloxane, an epoxy-modified organopolysiloxane, an amino-modified organopolysiloxane, an alcohol-modified organopolysiloxane, and a carboxyl-modified organopolysiloxane. The aqueous coating composition according to claim 1, which is at least one kind. 6. An acetylenic compound (B) in an amount of 100 parts by weight of resin solid content of the aqueous resin emulsion (A).
1 to 20 parts by weight, organosilicon compound (C) 0.1 to 20
The aqueous coating composition according to claim 1, comprising parts by weight. 7. The aqueous coating composition according to claim 1, further comprising a wax component (D). 8. The aqueous coating composition according to claim 7, which comprises 0.1 to 20 parts by weight of the wax component (C) based on 100 parts by weight of the aqueous resin emulsion (A). 9. An aqueous resin emulsion (A), according to claim 1.
The method for producing the aqueous coating composition according to claim 1, wherein the acetylene-based compound (B) and the organosilicon compound (C) are mixed. 10. A method for coating the surface of a porous inorganic substrate with the coating composition according to claim 1.