JPH0616712A - Aqueous dispersible type composition and its production - Google Patents

Abstract

PURPOSE:To obtain a composition, having stabilized silyl group and capable of stably performing dispersion polymerization and providing weather-resistant films excellent in preservation stability by carrying out the synthesis of a silyl group-containing water-soluble resin in the presence of a hydrolyzable ester and/or an alcohol. CONSTITUTION:An acrylic copolymer containing silyl group expressed by the formula [R<1> is 1-10C alkyl, aryl or aralkyl; X is halogen, hydroxy, alkoxy, acyloxy, aminooxy, phenoxy, thioalkoxy or amino; (a) is 0-2] is subjected to the dispersion polymerization in an aqueous solution of a water-soluble resin having the silyl group expressed by the formula. In the process, the polymerization is carried out in the presence of a hydrolyzable ester and/or an alcohol. An orthoacetic acid ester or a hydrolyzable silicon compound is used as the hydrolyzable ester. Methanol is used as the alcohol.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an aqueous dispersion type composition having good coating performance in various coatings such as interior and exterior constructions, automobiles, home appliances, plastics, etc., particularly in applications where weather resistance and durability are required. And a manufacturing method thereof.

[0002]

2. Description of the Related Art In recent years, in the field of paints and adhesives, from the viewpoint of pollution control and resource saving, there has been a shift from the use of organic solvents to water-soluble or water-dispersible resins. Being tried. However, the conventional aqueous dispersion type resin is produced by an emulsion polymerization method using an ionic or nonionic surfactant, and as a result, the coating film formed by the influence of the surfactant used for the polymerization. However, due to the difference in film forming mechanism, the gloss of the coating film was inferior to that of the solvent type.

Various attempts have been proposed to improve this drawback. One of them is to use a water-soluble polymer compound such as a maleinized polybutadiene, a maleinized alkyd resin or a water-soluble acrylic resin as a dispersion stabilizer. And a functional group capable of reacting with a silyl group in an aqueous solution of a water-soluble synthetic resin having a hydrolyzable silyl group in order to improve the water resistance and weather resistance. A method for producing an emulsion polymer, characterized by emulsion-polymerizing a comonomer containing a vinyl monomer having
No. 01) is proposed. However, since the hydrolyzable silyl group is unstable, it easily gels during the synthesis or storage of the emulsion polymer, and it has a drawback that it cannot be stably produced.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to solve the above problems, and as a result, the general formula (I)
By synthesizing the water-soluble resin (A) having a silyl group represented by, in the presence of the hydrolyzable ester (C) and / or alcohol (D), the silyl group in (A) is stabilized, The present inventors have found that the dispersion polymerization of (B) in the aqueous solution of A) can be carried out stably, and that the storage stability of the emulsion has no problem.

That is, the present invention has the general formula (I):

[0006]

[Chemical 3]

(In the formula, R ¹ is a monovalent hydrocarbon group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group and an aralkyl group, X is a halogen atom, a hydroxy group, an alkoxy group, an acyloxy group and an aminoxy group. Group, phenoxy group,
In a water-soluble solution of a water-soluble resin (A) having a silyl group represented by a monovalent group selected from a thioalkoxy group and an amino group, a is 0, 1 or 2, In dispersion-polymerizing the represented silyl group-containing acrylic copolymer (B), the water-soluble resin (A) is polymerized in the presence of a hydrolyzable ester (C) and / or alcohol (D). The obtained aqueous dispersion-type composition and a method for producing the same.

[0008]

EXAMPLES The water-soluble resin (A) having a silyl group used in the present invention is a vinyl monomer (a-
1), a vinyl monomer (a-2) having a water-soluble group or a group capable of forming a water-soluble group, and another vinyl monomer (a-3) copolymerizable with these monomers It can be obtained by copolymerizing in the presence of a decomposable ester (C) and / or alcohol (D) and, if necessary, making it water-soluble.

[Vinyl monomer having a silyl group (a-
1)] The vinyl monomer (a-1) having a silyl group used for the synthesis of the water-soluble resin (A) having a silyl group is represented by a polymerizable double bond and a general formula (I) in one molecule. There is no particular limitation as long as it is a compound containing a group, for example, CH ₂ ═CHS
i (OCH ₃ ) ₃ , CH ₂ ═CHSiCH ₃ (OC
_{H 3) 2, CH 2 =} CHCOO (CH 2) 3 Si (OC
_{H 3) 3, CH 2 =} C (CH 3) COO (CH 2) 3 S
_{i (OCH 3) 3, CH} 2 = C (CH 3) COO (CH
₂ ) ₃ Si (CH ₃ ) (OCH ₃ ) ₂ , CH ₂ = CHC
OO (CH ₂ ) ₃ Si (CH ₃ ) (OCH ₃ ) ₂ , CH
_{2 = CHSi (CH 3) Cl} 2, CH 2 = CHSiCl
₃ , CH ₂ = CHCOO (CH ₂ ) ₃ SiCl ₃ , CH
_{2 = CHCOO (CH 2) 3} Si (CH 3) Cl 2, C
_{H 2 = C (CH 3)} COO (CH 2) 3 SiCl 3, C
_{H 2 = C (CH 3)} COO (CH 2) 3 Si (CH 3)
_{Cl 2, CH 2 = CHSi (} OC 2 H 5) 3, CH 2 =
_{CHSi (CH 3) (OC 2} H 5) 2, CH 2 = CHS
_{i (OC 3 H 7) 3} , CH 2 = CHSi (OC 4 H 9)
₃ , CH ₂ = CHSi (OC ₆ H ₁₃ ) ₃ , CH ₂ = CHSi (O
_{C 8 H 17) 3, CH} 2 = CHSi (O-isoC
_{3 H 7) 3, CH 2} = CHSi (O-isoC 4 H 9)
₃ , CH ₂ = CHCOO (CH ₂ ) ₃ Si (OC
₂ H ₅ ) ₃ , CH ₂ = C (CH ₃ ) COO (CH ₂ ) _{3
Si (OC 2 H 5) 3} , CH 2 = CHCOO (CH 2)
_{3 Si (CH 3) (OC} 2 H 5) 2, CH 2 = C (CH
_{3) COO (CH 2) 3} Si (CH 3) (OC 2 H 5)
₂ , CH ₂ = CHCOO (CH ₂ ) ₃ Si (OC
_{6 H 13) 3, CH 2} = C (CH 3) COO (CH 2) 3
Si (OC ₆ H ₁₃ ) ₃ ,

[0010]

[Chemical 4]

And the like. The vinyl monomer (a-1) having a silyl group may be used alone or in combination of two or more thereof. 1 out of 100 parts by weight of the vinyl monomer mixture (parts by weight, hereinafter the same).
If it is less than 1 part, which is preferably 2 to 20 parts, the water resistance and weather resistance will be poor, and if it exceeds 50 parts, the stability of the emulsion will be deteriorated.

[Vinyl monomer having a water-soluble group or a group capable of forming a water-soluble group (a-2)] A vinyl monomer having a water-soluble group used in the present invention or a group capable of forming a water-soluble group As the body (a-2), (meth) acrylic acid,
Acids having a polymerizable double bond such as itaconic acid, crotonic acid, maleic acid, fumaric acid, styrene sulfonic acid, vinyl sulfonic acid; or salts thereof (alkali metal salts, ammonium salts, amine salts, etc.); maleic anhydride Acid anhydrides such as acids or half esters of them with linear or branched alcohols having 1 to 20 carbon atoms; dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, diethylaminoethyl (meth)
(Meth) acrylate having an amino group such as acrylate; (meth) acrylamide, α-ethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N, N-dimethylacrylamide, N-methylacrylamide, acryloylmorpholine or them Hydrochloric acid, acetate, etc.

The monomer (a-2) is copolymerized in an acid form,
Then, a method of forming a salt by neutralization is preferable from the viewpoint of stabilizing the alkoxysilyl group.

The (a-2) may be used alone or in combination of two or more, and is used in an amount of 0 to 30 parts, preferably 0.1 to 20 parts, based on 100 parts of the monomer mixture. If it exceeds 30 parts, the stability of the emulsion tends to decrease.

[Other copolymerizable vinyl monomer (a-
3)] As other copolymerizable vinyl-based monomer (a-3), for example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate,
Derivatives of (meth) acrylic acid such as 2-ethylhexyl (meth) acrylate, stearyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, lauryl (meth) acrylate, glycidyl (meth) acrylate; 2-trifluoroethyl (meth) acrylate, 2,2,3
3,3-pentafluoropropyl (meth) acrylate, perfluorocyclohexyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl methacrylate, β- (perfluorooctyl) ethyl (meth)
Fluorine-containing vinyl monomer such as acrylate; 1- (3-
(Meth) acryloxypropyl) -1,1,3,3,3
-Pentamethyldisiloxane, 3- (meth) acryloxypropyltris (trimethylsiloxy) silane, AK
-5 (siloxane macromer manufactured by Toagosei Kagaku Kogyo Co., Ltd.) and other siloxane-containing vinyl monomers; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxyethyl vinyl ether, N- Methylol (meth) acrylamide, trade name Aronix 5700 (hydroxyl group-containing monomer) manufactured by Toagosei Kagaku Kogyo Co., Ltd., 4-hydroxystyrene, HE-10, HE-20, HP-10 manufactured by Nippon Shokubai Kagaku Kogyo Co., Ltd. And HP-20 (both are acrylic acid ester oligomers having a hydroxyl group at the end), Bremmer P manufactured by NOF CORPORATION
P series (polypropylene glycol methacrylate), Blemmer PE series (polyethylene glycol monomethacrylate), Blemmer PEP series (polyethylene glycol polypropylene glycol methacrylate), Blemmer AP-400 (polypropylene glycol monoacrylate), Blemmer AE-35
0 (polyethylene glycol monoacrylate), Blemmer NKH-5050 (polypropylene glycol polytrimethylene monoacrylate) and Blemmer GLM
(Glycerol monomethacrylate), Placcel FA-1, FA-4, FM- manufactured by Daicel Chemical Industries, Ltd.
1, hydroxyl-containing vinyl compounds such as FM-4 and ε-
Hydroxyl group-containing vinyl monomers such as ε-caprolactone-modified hydroxyalkyl vinyl-based monomers obtained by reaction with caprolactone; AS-6 and AN- which are macromonomers (reactive polymers) of Toa Gosei Chemical Industry Co., Ltd.
6, AA-6, B-6; Aromatic hydrocarbon vinyl compounds such as styrene, α-methylstyrene, chlorostyrene and vinyltoluene; Vinyl acetate and allyl compounds such as vinyl acetate, vinyl propionate and diallyl phthalate; Other vinyl compounds such as methyl vinyl ether, cyclohexyl vinyl ether, vinyl chloride, vinylidene chloride, chloroprene, propylene, butadiene, isoprene, fluoroolefin maleimide, N-vinyl imidazole and the like can be mentioned.

Copolymerization of a fluorine-containing vinyl monomer and a siloxane-containing vinyl monomer improves the water repellent property,
The durability is improved. Hydroxyl group-containing vinyl monomer, or
When a hydrophilic monomer such as polypropylene glycol methacrylate or polyethylene glycol monomethacrylate is copolymerized, the stability of the silyl group-containing water-soluble resin (A) is increased, and water-soluble groups such as acrylic acid and dimethylaminoethyl (meth) acrylate are added. Alternatively, the amount of the vinyl monomer (a-2) having a group capable of forming a water-soluble group can be reduced.

[Hydrolysable ester (C)] Examples of the hydrolyzable ester (C) include an orthocarboxylic acid ester and / or a hydrolyzable silicon compound and / or a partial hydrolysis product thereof. These hydrolyzable esters (C) decompose water in the system by being present during the synthesis of the water-soluble resin (A) and stabilize the silyl group represented by the general formula (I) contained in (A). .

Specific examples of the orthocarboxylic acid ester include methyl orthoformate, ethyl orthoformate, propyl orthoformate, methyl orthoacetate, ethyl orthoacetate, propyl orthoacetate, methyl orthopropionate, ethyl orthopropionate, orthopropionate. Examples thereof include propyl, methyl orthobutyrate, ethyl orthobutyrate, propyl orthobutyrate and the like.

As the hydrolyzable silicon compound, methyl silicate, ethyl silicate, tetraacetoxysilane, methyltrimethoxysilane,

[0020]

[Chemical 5]

Examples include ethyl silicate 40 and HAS-1 of Colcoat Co., Ltd., and products obtained by partially hydrolyzing these hydrolyzable silicon compounds with water. Of these, methyl orthoacetate is preferable from the viewpoint of dehydration effect and economy.

The hydrolyzable ester (C) is used in an amount of 1 part or more, preferably 2 parts or more, based on 100 parts of the silyl group-containing water-soluble resin or monomer mixture. If it is less than 1 part, the dehydration effect is not sufficient. Hydrolyzable ester (C) is (A)
It may be added at the initial stage of component polymerization, or may be continuously added by mixing with the monomer mixture. It may also be used as a polymerization solvent.

[Alcohol (D)] Alcohol (D)
Stabilizes the silyl group through an equilibrium reaction. Specific examples of the alcohol include methanol, ethanol, n-propanol, iso-propanol, n-butanol,
Alcohols having 1 to 4 carbon atoms such as iso-butanol are preferable, and methanol is particularly preferable.

The alcohol (D) is used in an amount of 1 part or more, preferably 2 parts or more, based on 100 parts of the silyl group-containing water-soluble resin or monomer mixture. If it is less than 1 part, the stabilizing effect is insufficient. The alcohol (D) may be added at the initial stage of polymerization of the component (A), or may be continuously added by mixing with the monomer mixture. It may also be used as a polymerization solvent.

The silyl group-containing water-soluble resin (A) is polymerized by
It is possible to carry out any of the commonly used polymerization methods, such as emulsion polymerization method, suspension polymerization method, solution polymerization method, etc., but the solution polymerization method is preferably used because of the ease of operation. .

In carrying out the solution polymerization, the solvent to be used is not particularly limited as long as it can dissolve the copolymerization reaction product, but the polymer is dissolved in an aqueous medium and used as a dispersion stabilizer for the polymerization. At this time, it is preferable to use a water-soluble organic solvent because the operation is easier if the solvent does not have to be recovered. Alternatively, the solvent may be recovered, and the isolated copolymer may be used as a dispersion stabilizer for polymerization.

As the solvent to be used, an alcohol solvent having a linear and / or branched chain having 1 to 10 carbon atoms, HO
(Poly) ethylene glycol monoalkyl ether represented by — (CH ₂ CH ₂ —O) _m —R ² (R ² is a linear and / or branched alkyl group having 1 to 10 carbon atoms,
m is an integer of 1 to 5), R ² CO—O— (CH ₂ CH ₂ —
O) _m- R ^{2 represented} by (poly) ethylene glycol ether ester (R ² is an alkyl group having a linear and / or branched chain having 1 to 10 carbon atoms, and alkyl groups at both ends may be the same or different. M may be an integer of 1 to 5),
_{HO- (CH 2 CH 2 CH 2} -O) m -R 2 represented by (poly) propylene glycol monoalkyl ether (R ² is an alkyl group having straight chain and (or) branched having 1 to 10 carbon atoms, m Is an integer of 1 to 5), R ² CO-O-
_{(CH 2 CH 2 CH 2 -O} ) represented by _m -R ² (poly) propylene glycol ether ester (R ² is an alkyl group of the alkyl. Both ends with linear and (or) branched having 1 to 10 carbon atoms May be the same or different, and m may be an integer of 1 to 5). In particular,
For example, alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, hexyl alcohol and octyl alcohol; cellosolve, ethyl cellosolve, butyl cellosolve, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol. Monoethyl ether, propylene glycol monobutyl ether,
Ethers such as propylene glycol monoisobutyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monobutyl ether, dipropylene glycol isobutyl ether, tripropylene glycol monoethyl ether, tripropylene glycol monobutyl ether, tripropylene glycol isobutyl ether; butyl cellosolve acetate , Diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, dipropylene glycol monoethyl ether acetate, dipropylene glycol monobutyl ether acetate, tripropylene glycol monoethyl ether acetate, tripropylene glycol monobutyl ether acetate, tripropyi Ether esters such as glycol monoisobutyl ether acetate.

The polymerization initiator is not particularly limited as long as it is a commonly used initiator, and redox type initiators, azo type initiators and peroxides may be used. Among these initiators, azo-based initiators are preferable, and specific examples include:
For example, azo-based nitriles such as azobisisobutyronitrile, azobisdimethylvaleronitrile, azobiscyclohexanecarbonitrile, azobismethylbutyronitrile, azobisdimethylmethoxyvaleronitrile; V-5
Azoamidines such as 0, VA041, VA-044, VA-061 (all manufactured by Wako Pure Chemical Industries, Ltd.); VA-080, VA-
Azoamidines such as 086, VA-088 (all manufactured by Wako Pure Chemical Industries, Ltd.); VA-080, VA-086, VA-088
(Above, Wako Pure Chemical Industries, Ltd.) and other azoamides; azodi-
Azoalkyls such as tert-octane and azodi-tert-butane; cyanopropylazoformamide, azobiscyanovaleroleic acid, dimethylazobismethylpropionate, azobishydroxymethylpropionitrile and the like. Further, if necessary, n-dodecyl mercaptan, t-dodecyl mercaptan, n-butyl mercaptan, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ
-Mercaptopropylmethyldimethoxysilane, (CH
_{3 O) 3 Si-S-} S-Si- (OCH 3) 3, (CH
_{3 O) 3 Si- (CH 2} ) 3 -S-S- (CH 2) 3 -
_{Si- (OCH 3) 3, (} CH 3 O) 3 Si-S 8 -S
The molecular weight may be adjusted by using a chain transfer agent such as i (OCH ₃ ) ₃ .

Regarding the polymerization conditions, it is desirable to carry out the polymerization at a polymerization temperature of usually 40 to 170 ° C., preferably 50 to 150 ° C. for 3 to 24 hours, preferably 4 to 20 hours.

[Solubilization of silyl group-containing water-soluble resin (A)] When the aqueous dispersion polymerization is carried out using the silyl group-containing water-soluble resin (A) thus obtained, the polymer is first added to an aqueous medium. It is necessary to dissolve in. The aqueous medium here means water or water in which a water-soluble organic solvent is dissolved. When the vinyl monomer having a group capable of forming a water-soluble group has a carboxyl group, for example, caustic soda, causticari, ammonia, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, monomethanol can be made water-soluble. This can be achieved by neutralizing with amine, dimethanolamine, trimethanolamine, monoethanolamine, diethanolamine, triethanolamine, dimethylethanolamine, diethylethanolamine and the like.

When it has a basic group, it is quaternized with an acidic compound such as hydrochloric acid or acetic acid. From the viewpoints of polymerization rate, polymerization stability, and stability of hydrolyzable silyl functional groups, neutralization is preferably adjusted to pH 5 to pH 10, more preferably pH 6 to pH 7, by neutralization.

Further, upon water-solubilization, the copolymer may be mixed with an aqueous medium while being dissolved in a water-soluble organic solvent, or the polymer may be recovered by a method such as distillation or reprecipitation and then the aqueous medium. You can add it to.

[Acrylic Copolymer Containing Silyl Group (B)
Polymerization] The water-soluble resin (A) thus obtained is used as a dispersion stabilizer to carry out a polymerization reaction in an aqueous medium to obtain the desired aqueous dispersion-type composition (B).

As for the polymerization operation, a usual emulsion polymerization polymerization operation can be employed.

Acrylic copolymer containing silyl group (B)
The group represented by the general formula (I) can be introduced by copolymerizing the vinyl monomer (a-1) having a silyl group with another vinyl-based monomer. Can be used as they are, and may be used alone or in combination of two or more. The vinyl monomer having a silyl group is 1 to 50 parts, preferably 2 to 20 parts per 100 parts of the vinyl monomer mixture. If it is less than 1 part, the water resistance and weather resistance are inferior, and if it exceeds 50 parts, the emulsion stability decreases.

Other vinyl monomers copolymerizable with the vinyl monomer having a silyl group are not particularly limited, and specific examples thereof include the water-soluble monomers listed as the component of the silyl group-containing water-soluble resin (A). A vinyl monomer (a-2) having a group or a group capable of forming a water-soluble group and another copolymerizable vinyl monomer (a-3) can be used.

In addition to this, a monomer having two or more polymerizable unsaturated bonds such as polyethylene glycol dimethacrylate, ethylene glycol diacrylate, triallyl cyanurate, etc. is also used, and the resulting polymer is crosslinked. It is also possible to have

These monomers can be appropriately selected from one kind or two or more kinds according to the quality of the final product.
However, at least one of (a-1), (a-2) and (a-3) needs to be an acrylic monomer, and the acrylic monomer is used in 100 parts of the vinyl monomer mixture. Includes more than 50 copies.

The amount of the water-soluble resin used as the dispersion stabilizer is 1/20 to 1 in weight ratio with respect to the total amount of monomers to be polymerized.
The ratio is /0.3, preferably 1/10 to 1/1.

Water is usually used as the aqueous medium in which the dispersion stabilizer is dissolved. However, when the dispersant resin is used in a state of being dissolved in an organic solvent, as a result, an amount of organic solvent corresponding to the amount of the dispersant resin is used. Will be included in the system. In addition to the above, it is also possible to add a water-soluble organic solvent in an amount of ½ or less with respect to water for the purpose of increasing the solubility of the dispersant resin.

As the polymerization initiator, any of water-soluble or oil-soluble peroxides, azo type initiators, Redox initiators and the like which are usually used in radical polymerization can be used.
Water-soluble initiators are preferably used. Specific examples of the water-soluble initiator include, for example, sodium persulfate, potassium persulfate, ammonium persulfate, hydrogen peroxide, and ter.
t-butyl peroxide, cumene hydroperoxide,
Examples thereof include peroxides such as azodiisobutyric acid diamide, persulfates, and azo compounds, and redox initiators activated by a water-soluble reducing agent in an aqueous phase.

The amount of such an initiator used is 0.01 to 10 parts by weight, preferably 0.05 to 5 parts by weight, based on the weight of the monomer.

The ionic property usually used for emulsion polymerization,
Although it is possible to use a nonionic surfactant together, it is preferable to use only a small amount from the viewpoint of water resistance and weather resistance. Specific examples of the ionic and nonionic surfactants include, for example, potassium n-dodecylsulfonate, sodium isooctylbenzenesulfonate,
Examples thereof include sodium laurate and polyethylene glycol nonyl phenyl ether.

The polymerization can be carried out at a polymerization temperature of 30 to 90 ° C, preferably 40 to 80 ° C.

By the polymerization reaction, the monomers are copolymerized to form a silyl group-containing acrylic copolymer, but a part of the monomers may be graft-polymerized to the water-soluble resin (A) as a side reaction. It does not matter if there is.

According to the method of the present invention, the solid content concentration in the aqueous dispersion type composition is in the range of 20 to 70% by weight.

If the solid content concentration exceeds 70% by weight, the viscosity of the system remarkably rises, so that it is difficult to remove the heat generated by the polymerization reaction, and it takes a long time to take it out from the polymerization machine. Occurs. Further, when the solid content concentration is less than 20% by weight, no problem occurs in terms of polymerization operation, but the amount of resin produced by one polymerization operation is small, which is extremely disadvantageous from the economical point of view. Also, due to application requirements, the film thickness of the coating film becomes thin when the concentration is less than 20% by weight. It causes performance deterioration and is disadvantageous in terms of coating workability.

The thus obtained aqueous dispersion type composition is composed of ultrafine particles having a particle diameter of 0.02 to 0.1 micron, and as a result, has an excellent film forming ability.

A solvent may be added for the purpose of assisting the film formation of the aqueous dispersion type composition.
The amount of such a solvent added is 0.1 to 15 parts by weight, preferably 0.5 to 10 parts by weight, based on the aqueous dispersion type resin composition. Specific examples of such a solvent include, for example, cellosolve, ethyl cellosolve, butyl cellosolve, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, propylene glycol monoisobutyl ether, dipropylene glycol monoethyl ether. Ethers such as ether, dipropylene glycol monobutyl ether, dipropylene glycol isobutyl ether, tripropylene glycol monoethyl ether, tripropylene glycol monobutyl ether, tripropylene glycol isobutyl ether; butyl cellosolve acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobub Ether acetate, dipropylene glycol monoethyl ether acetate,
Examples thereof include ether esters such as dipropylene glycol monobutyl ether acetate, tripropylene glycol monoethyl ether acetate, tripropylene glycol monobutyl ether acetate, and tripropylene glycol monoisobutyl ether acetate.

These solvents may be added during the polymerization of the aqueous dispersion type resin, immediately after the completion of the polymerization, or after cooling.

The curable composition for water-dispersed coatings thus obtained may not use a curing catalyst, but a catalyst may be used in order to promote the curability and bring out the required physical properties. it can. Specific examples of such a curing catalyst include, for example, dibutyltin dilaurate, dibutyltin dimaleate, dioctyltin dilaurate, dioctyltin dimaleate, organotin compounds such as tin octylate; phosphoric acid, monomethyl phosphate, monoethyl phosphate, monobutyl. Phosphoric acid or phosphates such as phosphate, monooctyl phosphate, monodecyl phosphate, dimethyl phosphate, diethyl phosphate, dibutyl phosphate, dioctyl phosphate, didecyl phosphate; propylene oxide, butylene oxide, cyclohexene oxide, glycidyl methacrylate, glycidol, acrylic Glycidyl ether,
γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, (3,4-epoxycyclohexyl) ethyltrimethoxysilane, Yuka Shell Epoxy Co., Ltd. Addition products of epoxy compounds such as Cardura (E), Epikote 828, Epikote 1001 and the like and phosphoric acid and / or acidic monophosphate ester;
Organic titanate compounds; Organoaluminum compounds; Organozirconium compounds; Maleic acid, adipic acid, azelaic acid, sebacic acid, itaconic acid, citric acid, succinic acid, trimellitic acid, pyromellitic acid, their acid anhydrides, paratoluene sulfone Acidic compounds such as acids; amines such as hexylamine, di-2-ethylhexylamine, N, N-dimethyldodecylamine, dodecylamine;
Mixtures or reaction products of these amines and acidic phosphoric acid esters; alkaline compounds such as sodium hydroxide, potassium hydroxide and the like.

Among these curing catalysts, organotin compounds,
A mixture or reaction product of an acidic phosphoric acid ester and an amine,
Saturated or unsaturated polycarboxylic acid or its anhydride,
A reactive silicon compound, an organic titanate compound, an organic aluminum compound or a mixture thereof is preferable because of its high activity. More preferably, it is an organic tin compound, an acidic phosphoric acid ester, or a mixture or reaction product of an acidic phosphoric acid ester and an amine.

Such curing catalysts may be used alone or in combination of two or more kinds. The amount of the curing catalyst used is not particularly limited, but is usually 0.01 to 20 parts by weight, more preferably 0.1 to 100 parts by weight of the solid content of the aqueous dispersion type composition.
Use ~ 10 parts by weight. If the amount used exceeds 20 parts by weight, the appearance of the coating film tends to deteriorate.

In the obtained aqueous dispersion type composition, if necessary, a pigment (white pigment carbon such as titanium dioxide, calcium carbonate, barium carbonate, kaolin, colored pigment such as red iron oxide, cyanine blue), a plasticizer, It is also possible to mix and use additives used as usual coating compositions such as a solvent, a dispersant, a thickener, a defoaming agent, an antiseptic and an ultraviolet absorber.

It is also possible to blend with a commercially available water-based paint, and examples thereof include thermosetting acrylic paints such as acrylic paints and acrylic melamine paints, alkyd paints and epoxy paints. It is possible to improve weather resistance, acid resistance and solvent resistance.

It is also possible to add a melamine resin or an isocyanate compound as a cross-linking agent to obtain a fast curing property.

Next, the composition of the present invention will be described based on Examples.

Production Examples 1 to 8 (Polymerization of Water-Soluble Resin (A)) Isopropyl alcohol 60 was placed in a reaction vessel equipped with a stirrer, a thermometer, a reflux cooling tube, a nitrogen gas introducing tube and a dropping funnel.
After charging the part and raising the temperature to 75 ° C while introducing nitrogen gas,
The mixture having the composition shown in Table 1 was added dropwise at a constant speed by a dropping funnel over 5 hours. After the completion of dropping the mixture, the mixture was reacted at 75 ° C. for 2 hours, and then (A-1) to (A-6) were cooled after adding 8.5 parts of ammonia, and (A-7) and (A-8) were cooled. After adding 2 parts of glacial acetic acid, the mixture was cooled to obtain a water-soluble resin having a number average molecular weight of 5,500. Further, isopropyl alcohol was added to the resin solution so that the solid content concentration became 60%.

[0059]

[Table 1]

Examples 1 to 6 and Comparative Examples 1 and 2 (Polymerization of Aqueous Dispersion Resin) 93 parts of deionized water was placed in a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen gas inlet tube and a dropping funnel. Preparation,
1 part of ascorbic acid and 0.1 part of ferrous sulfate were added, and (the resin solutions (A-1) to (A obtained in Production Examples 1 to 8)
After adding 18.5 parts of -8) and thoroughly stirring to dissolve it,
After the temperature was raised to 70 ° C. while introducing nitrogen gas, a mixture having the following composition was added dropwise at a constant rate over 5 hours using a dropping funnel.

Styrene 20 parts Butyl acrylate 20 parts Methyl methacrylate 55 parts γ-methacryloxypropyltrimethoxysilane 5 parts Cumene hydroperoxide 1 part Polymerization results and deionized water was added to the obtained aqueous dispersion to obtain a solid content. Table 2 shows the results of a storage stability test conducted by adjusting the concentration to 50%.

[0062]

[Table 2]

[0063]

EFFECT OF THE INVENTION When dispersion-polymerizing a silyl group-containing acrylic copolymer in an aqueous solution of a silyl group-containing water-soluble resin, the water-soluble resin is synthesized in the presence of a hydrolyzable ester and / or alcohol. By doing so, dispersion polymerization can be stably carried out, and the storage stability of the product is good.

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Claims (6)

[Claims] 1. A compound represented by the general formula (I): (In the formula, R ¹ is a monovalent hydrocarbon group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group and an aralkyl group;
Is a monovalent group selected from a halogen atom, a hydroxy group, an alkoxy group, an acyloxy group, an aminoxy group, a phenoxy group, a thioalkoxy group and an amino group, and a is a silyl group represented by 0). When the silyl group-containing acrylic copolymer (B) represented by the general formula (I) is dispersion-polymerized in an aqueous solution of the water-soluble resin (A), the polymerization of the water-soluble resin (A) is hydrolyzed. Dispersion-type composition obtained in the presence of a soluble ester (C) and / or an alcohol (D). 2. The aqueous dispersion type composition according to claim 1, wherein the hydrolyzable ester (C) is an orthocarboxylic acid ester, and / or a hydrolyzable silicon compound and / or a partial hydrolysis product thereof. . 3. The composition according to claim 1, wherein the alcohol (D) is methanol. 4. The aqueous dispersion type composition according to claim 2, wherein the orthocarboxylic acid ester is an orthoacetic acid ester or an orthoformate ester. 5. The aqueous dispersion-type composition according to claim 1, wherein the water-soluble resin (A) having a carboxyl group neutralized with ammonia or an organic amine compound is used. 6. A compound represented by the general formula (I): (In the formula, R ¹ is a monovalent hydrocarbon group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group and an aralkyl group;
Is a monovalent group selected from a halogen atom, a hydroxy group, an alkoxy group, an acyloxy group, an aminoxy group, a phenoxy group, a thioalkoxy group and an amino group, and a is a silyl group represented by 0). When the silyl group-containing acrylic copolymer (B) represented by the general formula (I) is dispersion-polymerized in an aqueous solution of the water-soluble resin (A) that it has, to produce the aqueous dispersion-type composition according to claim 1. In addition, the water-soluble resin (A) is polymerized in the presence of a hydrolyzable ester (C) and / or an alcohol (D) to produce an aqueous dispersion-type composition. Law.