JP6925150B2 - Resin emulsion - Google Patents

Description

The present invention relates to resin emulsions. More specifically, the present invention is referred to as, for example, a top coat applied to the surface of ceramic building materials, automobiles, buildings, civil engineering structures, etc., particularly the exterior of buildings, ceramic building materials, etc. The present invention relates to a topcoat paint, a resin emulsion that can be suitably used for the topcoat paint, and a method for producing the same.

A water-based paint that has good storage stability and can form a coating film with low gloss and excellent water repellency, water resistance, weather resistance, gloss retention and stain resistance even when a small amount of silicone resin aqueous dispersion is used. As the composition, a (meth) acrylic polymer emulsion (A) obtained by polymerizing a (meth) acrylic monomer containing 2 to 15% by mass of a hydroxyl group-containing polymerizable monomer, a silicone resin aqueous dispersion. (B) and a high HLB surfactant (C) having an HLB of 16 to 20 are contained, and the high HLB surfactant (C) is 0 with respect to 100 parts by mass of the (meth) acrylic polymer emulsion (A). A water-based coating composition containing 2 to 2 parts by mass has been proposed (see, for example, claim 1 of Patent Document 1).

A triazine-based ultraviolet absorber is used in the water-based coating composition for the purpose of improving weather resistance (see paragraph [0054] of Patent Document 1). However, since the triazine-based ultraviolet absorber is inferior in durability in the resin emulsion, the coating film formed by using the resin emulsion is not only inferior in the appearance retention of ultraviolet rays but also inferior in the ultraviolet transmission resistance. (See Comparative Example 1 herein).

Japanese Unexamined Patent Publication No. 2011-213941

The present invention has been made in view of the above-mentioned prior art, and is a resin emulsion containing a triazine-based ultraviolet absorber, which forms a coating film having excellent ultraviolet transmissivity and ultraviolet appearance retention. An object of the present invention is to provide a method for producing the same and a topcoat coating material containing the resin emulsion.

The present invention
(1) A resin emulsion containing a triazine-based ultraviolet absorber, characterized in that a polymerizable hindered amine-based photostable monomer is used as a monomer component used as a resin raw material of the resin emulsion. Resin emulsion,
(2) The resin emulsion according to (1) above, wherein the resin emulsion is a resin emulsion containing emulsion particles containing a triazine-based ultraviolet absorber.
(3) A topcoat coating material containing the resin emulsion according to (1) or (2) above.
(4) A method for producing a resin emulsion containing a triazine-based ultraviolet absorber, in which a polymerizable hindered amine is used as the monomer component when a monomer component is polymerized in the presence of the triazine-based ultraviolet absorber. A method for producing a resin emulsion, which comprises using a monomer component containing a system photostable monomer, and (5) the above (4), wherein the monomer component contains a triazine-based ultraviolet absorber. The present invention relates to the method for producing a resin emulsion.

According to the present invention, a resin emulsion containing a triazine-based ultraviolet absorber, which comprises a resin emulsion that forms a coating film having excellent ultraviolet transmission resistance and ultraviolet appearance retention, a method for producing the same, and the resin emulsion. Topcoat paint is provided.

As described above, the resin emulsion of the present invention contains a triazine-based ultraviolet absorber, and a polymerizable hindered amine-based photostable monomer is used as a monomer component used as a resin raw material of the resin emulsion. It is characterized by that.

The resin emulsion of the present invention contains a triazine-based ultraviolet absorber, but since a polymerizable hindered amine-based photostable monomer is used as a monomer component used as a resin raw material for the resin emulsion, it is ultraviolet-resistant. Form a coating film with excellent transparency and UV appearance retention.

In the present invention, among various UV absorbers, a triazine-based UV absorber is used in the resin emulsion, and the monomer component used as the resin raw material of the resin emulsion has polymerizable hindered amine-based photostability. A major feature is that monomers are used. As described above, in the present invention, the triazine-based ultraviolet absorber is used in the resin emulsion, and the polymerizable hindered amine-based photostable monomer is used as the monomer component, and the resin emulsion of the present invention is used. In combination with these configurations, not only is it excellent in ultraviolet transmission resistance, but also an exceptionally excellent effect that cannot be expected from the prior art of forming a coating film having excellent ultraviolet appearance retention is exhibited. NS.

The resin emulsion of the present invention is, for example, a method of polymerizing a monomer component in the presence of a triazine-based ultraviolet absorber, an emulsion polymerization of the monomer component, and a mixture of the obtained resin emulsion and a triazine-based ultraviolet absorber. It can be obtained by the method of Among these methods, in the presence of a triazine-based UV absorber, from the viewpoint of forming a coating film having excellent UV transmission resistance and UV appearance retention, water resistance, repeated freeze-thaw stability, and transparency. A method of polymerizing the monomer component is preferable.

Examples of the method of polymerizing the monomer component in the presence of the triazine-based ultraviolet absorber include a method of polymerizing the monomer component containing the triazine-based ultraviolet absorber and an aqueous medium containing the triazine-based ultraviolet absorber. Examples thereof include a method of emulsion-polymerizing a monomer component in the presence of the present invention, but the present invention is not limited to such an example. Among these methods, a single amount containing a triazine-based ultraviolet absorber from the viewpoint of forming a coating film having excellent ultraviolet transmission resistance and ultraviolet appearance retention, water resistance, repeated freeze-thaw stability, and transparency. A method of polymerizing body components is preferable.

Below, as a method of polymerizing a monomer component in the presence of a triazine-based ultraviolet absorber, when a monomer component is polymerized in the presence of a triazine-based ultraviolet absorber, a polymerizable hindered amine-based monomer component is used. A method for preparing a resin emulsion by using a monomer component containing a photostable monomer will be described.

Examples of the triazine-based ultraviolet absorber include 2- [4-[(2-hydroxy-3-dodecyloxypropyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl)-. 1,3,5-triazine, 2- [4-[(2-hydroxy-3-tridecyloxypropyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1 , 3,5-Triazine, 2- [4-[(2-Hydroxy-3- (2'-ethyl) hexyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2,4-bis (2-hydroxy-4-butyloxyphenyl) -6- (2,4-bis-butyloxyphenyl) -1,3,5-triazine, hydroxyphenyl Triazine, 2- (2-hydroxy-4- [1-octyloxycarbonylethoxy] phenyl) -4,6-bis (4-phenylphenyl) -1,3,5-triazine, 2,4,6-tris ( Examples thereof include hydroxyphenyltriazine-based ultraviolet absorbers such as 2-hydroxy-4-hexyloxy-3-methylphenyl) -1,3,5-triazine, but the present invention is not limited to these examples. No. These triazine-based ultraviolet absorbers may be used alone or in combination of two or more. Among these triazine-based UV absorbers, 2- [4-] from the viewpoint of forming a coating film having excellent UV transmissivity and UV appearance retention, water resistance, repeated freeze-thaw stability, and transparency. [(2-Hydroxy-3-dodecyloxypropyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- [4-[( 2-Hydroxy-3-tridecyloxypropyl) Oxy] -2-Hydroxyphenyl] -4,6-Bis (2,4-dimethylphenyl) -1,3,5-Triazine and other hydroxyphenyltriazine-based UV absorbers Is preferable.

Triazine-based UV absorbers are readily available commercially. As an example, for example, manufactured by BASF Japan Co., Ltd., trade name: TINUVIN (registered trademark, the same applies hereinafter) 400 [2- [4-[(2-hydroxy-3-dodecyloxypropyl) oxy] -2-hydroxy Phenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine and 2- [4-[(2-hydroxy-3-tridecyloxypropyl) oxy] -2-hydroxyphenyl ] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine], TINUVIN405 [2- [4-[(2-hydroxy-3- (2'-ethyl) hexyl) ) Oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine], TINUVIN460 [2,4-bis (2-hydroxy-4-butyloxyphenyl) ) -6- (2,4-bis-butyloxyphenyl) -1,3,5-triazine], TINUVIN477 [hydroxyphenyltriazine], TINUVIN479 [2- (2-hydroxy-4- [1-octyloxycarbonylethoxy] ] Phenyl) -4,6-bis (4-phenylphenyl) -1,3,5-triazine], manufactured by ADEKA Co., Ltd., trade name: Adecaster (registered trademark) F70 [2,4,6-tris (2) -Hydroxy-4-hexyloxy-3-methylphenyl) -1,3,5-triazine] and other hydroxyphenyltriazine-based ultraviolet absorbers can be mentioned, but the present invention is not limited to these examples. No. These triazine-based ultraviolet absorbers may be used alone or in combination of two or more.

The amount of the triazine-based ultraviolet absorber per 100 parts by mass of the monomer component used as the resin raw material of the resin emulsion of the present invention is preferable from the viewpoint of forming a coating film having excellent ultraviolet transmission resistance and ultraviolet appearance retention. Is 0.1 part by mass or more, more preferably 0.2 part by mass or more, further preferably 0.3 part by mass or more, still more preferably 0.5 part by mass or more, and has water resistance, freeze-thaw repeat stability and From the viewpoint of forming a coating film having excellent transparency, it is preferably 5 parts by mass or less, more preferably 4.5 parts by mass or less, still more preferably 4 parts by mass or less, and even more preferably 3.5 parts by mass or less. ..

Examples of the polymerizable hindered amine-based photostable monomer include 4- (meth) acryloyloxy-2,2,6,6-tetramethylpiperidine and 4- (meth) acryloylamino-2,2,6,6. -Tetramethylpiperidin, 4- (meth) acryloyloxy-1,2,2,6,6-pentamethylpiperidine, 4- (meth) acryloyl-1-methoxy-2,2,6,6-tetramethylpiperidine, 4-Cyano-4- (meth) acryloyloxy-2,2,6,6-tetramethylpiperidine, 1- (meth) acryloyl-4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine , 4-Crotonoylamino-2,2,6,6-tetramethylpiperidine, 4- (meth) acryloylamino-1,2,2,6,6-pentamethylpiperidin, 4-cyano-4- (meth) Acryloylamino-2,2,6,6-tetramethylpiperidine, 4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, 1- (meth) acryloyl-4-cyano-4- (meth) acryloyl Examples thereof include amino-2,2,6,6-tetramethylpiperidine, 1-crotonoyl-4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, but the present invention is limited to such examples. It is not something that is done. These polymerizable hindered amine-based photostable monomers may be used alone or in combination of two or more. Among these polymerizable hindered amine-based photostable monomers, from the viewpoint of forming a coating film having excellent ultraviolet transmission resistance and ultraviolet appearance retention, water resistance, repeated freeze-thaw stability, and transparency, 4- (Meta) acryloyloxy-2,2,6,6-tetramethylpiperidine and 4- (meth) acryloyloxy-1,2,2,6,6-pentamethylpiperidine are preferred, 4-methacryloyloxy-2. , 2,6,6-tetramethylpiperidine and 4-methacryloyloxy-1,2,2,6,6-pentamethylpiperidine are more preferred.

In the present specification, "(meth) acryloyl" means "acryloyl" or "methacrylic acid", "(meth) acrylate" means "acrylate" or "methacrylate", and "(meth) acrylic" means "acrylic". Or "methacrylic".

The content of the polymerizable hindered amine-based photostable monomer in the monomer component is preferably 0.1% by mass or more, from the viewpoint of forming a coating film having excellent ultraviolet transmission resistance and ultraviolet appearance retention. It is preferably 0.3% by mass or more, more preferably 0.5% by mass or more, and preferably 25% by mass or less, more preferably 25% by mass or less, from the viewpoint of forming a coating film having excellent water resistance and freeze-thaw repeat stability. It is 20% by mass or less, more preferably 15% by mass or less.

As the monomer component, a monomer other than the polymerizable hindered amine-based photostable monomer (hereinafter, simply referred to as “other monomer”) can be used.

Examples of other monomers include alkyl (meth) acrylates, cycloalkyl (meth) acrylates having a cycloalkyl group having 3 to 12 carbon atoms, hydroxyl group-containing (meth) acrylates, silane group-containing monomers, and aromatics. System-based monomer, carboxyl group-containing monomer, nitrogen atom-containing monomer, oxo group-containing monomer, fluorine atom-containing monomer, epoxy group-containing monomer, ultraviolet-absorbing monomer, polymerizable hindered amine Examples thereof include photostable monomers other than system-based photostable monomers, but the present invention is not limited to these examples. These other monomers may be used alone or in combination of two or more. Among these other monomers, alkyl (meth) acrylates are excellent in ultraviolet transmittance and ultraviolet appearance retention, and from the viewpoint of forming a coating film having excellent water resistance, freeze-thaw repeated stability and transparency. , Cycloalkyl (meth) acrylate having a cycloalkyl group having 3 to 12 carbon atoms, hydroxyl group-containing (meth) acrylate, silane group-containing monomer and aromatic monomer are preferable, and alkyl (meth) acrylate and carbon number of carbon atoms are preferable. Cycloalkyl (meth) acrylates having 3 to 12 cycloalkyl groups, hydroxyl group-containing (meth) acrylates and silane group-containing monomers are more preferable, and alkyl (meth) acrylates have cycloalkyl groups having 3 to 12 carbon atoms. Cycloalkyl (meth) acrylates and hydroxyl group-containing (meth) acrylates are more preferred.

Examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, and sec-butyl (meth). Alkyl (meth) acrylates having 1 to 18 carbon atoms in alkyl groups such as acrylates, 2-ethylhexyl (meth) acrylates, n-octyl (meth) acrylates, tridecyl (meth) acrylates, and n-lauryl (meth) acrylates. However, the present invention is not limited to such an example. These alkyl (meth) acrylates may be used alone or in combination of two or more. Among these alkyl (meth) acrylates, the number of carbon atoms of the alkyl group is excellent from the viewpoint of forming a coating film having excellent ultraviolet transmittance and ultraviolet appearance retention, water resistance, repeated freeze-thaw stability and transparency. Alkyl (meth) acrylates having a value of 1 to 8 are preferable, and methyl (meth) acrylate, n-butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate are more preferable.

The content of the alkyl (meth) acrylate in the monomer component is preferably 10% by mass or more, more preferably 20% by mass, from the viewpoint of forming a coating film having excellent water resistance, freeze-thaw repeated stability and transparency. The above is more preferably 30% by mass or more, and is preferably 85% by mass from the viewpoint of forming a coating film having excellent UV transmittance and UV appearance retention, water resistance, repeated freeze-thaw stability, and transparency. % Or less, more preferably 80% by mass or less, still more preferably 75% by mass or less.

Examples of the cycloalkyl (meth) acrylate having a cycloalkyl group having 3 to 12 carbon atoms include cyclopropyl (meth) acrylate, cyclobutyl (meth) acrylate, cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, and isobornyl (meth). ) Acrylate and the like, but the present invention is not limited to such examples. These cycloalkyl (meth) acrylates having a cycloalkyl group having 3 to 12 carbon atoms may be used alone or in combination of two or more. Among these cycloalkyl (meth) acrylates having a cycloalkyl group having 3 to 12 carbon atoms, a coating having excellent ultraviolet transmission resistance and ultraviolet appearance retention, water resistance, repeated freeze-thaw stability, and transparency. From the viewpoint of forming a film, a cycloalkyl (meth) acrylate having a cycloalkyl group having 3 to 10 carbon atoms is preferable, a cycloalkyl (meth) acrylate having a cycloalkyl group having 4 to 8 carbon atoms is more preferable, and cyclohexyl (meth) acrylate is more preferable. Meta) acrylate is more preferred.

The content of cycloalkyl (meth) acrylate having a cycloalkyl group having 3 to 12 carbon atoms in the monomer component is excellent in UV transmission resistance and UV appearance retention, water resistance, freeze-thaw repeated stability and transparency. From the viewpoint of forming an excellent coating film, the coating is 0% by mass or more, preferably 10% by mass or more, more preferably 15% by mass or more, still more preferably 20% by mass or more, and has excellent freeze-thaw repeated stability. From the viewpoint of forming a film, it is preferably 80% by mass or less, more preferably 70% by mass or less, and further preferably 60% by mass or less.

Examples of the hydroxyl group-containing (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 4-hydroxy. Examples thereof include hydroxyl group-containing (meth) acrylates having 1 to 18 carbon atoms in ester groups such as butyl (meth) acrylate and glycerin mono (meth) acrylate, but the present invention is not limited to these examples. .. These hydroxyl group-containing (meth) acrylates may be used alone or in combination of two or more. Among these hydroxyl group-containing (meth) acrylates, 2-hydroxyethyl is excellent in ultraviolet transmission resistance and ultraviolet appearance retention, and from the viewpoint of forming a coating film excellent in water resistance, freeze-thaw repeated stability and transparency. (Meta) acrylate and glycerin mono (meth) acrylate are preferable, and 2-hydroxyethyl methacrylate is more preferable.

The content of the hydroxyl group-containing (meth) acrylate in the monomer component is excellent in ultraviolet transmission resistance and ultraviolet appearance retention, and from the viewpoint of forming a coating film having excellent water resistance, freeze-thaw repeated stability and transparency. It is 0% by mass or more, preferably 0.1% by mass or more, more preferably 0.3% by mass or more, still more preferably 0.5% by mass or more, and has excellent ultraviolet transmission resistance and ultraviolet appearance retention, and water resistance. From the viewpoint of forming a coating film excellent in freeze-thaw repeated stability and transparency, it is preferably 10% by mass or less, more preferably 5% by mass or less, and further preferably 3% by mass or less.

Examples of the silane group-containing monomer include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri (methoxyethoxy) silane, γ- (meth) acryloyloxypropyltrimethoxysilane, 2-styrylethyltrimethoxysilane, and vinyltri. Examples thereof include chlorosilane, γ- (meth) acryloyloxypropylhydroxysilane, and γ- (meth) acryloyloxypropylmethylhydroxysilane, but the present invention is not limited to these examples. These silane group-containing monomers may be used alone or in combination of two or more. Among these silane group-containing monomers, γ- (meth) is excellent from the viewpoint of forming a coating film having excellent ultraviolet transmission resistance and ultraviolet appearance retention, water resistance, repeated freeze-thaw stability, and transparency. ) Acryloyloxypropyltrimethoxysilane is preferable, and γ-methacryloyloxypropyltrimethoxysilane is more preferable.

The content of the silane group-containing monomer in the monomer component is excellent in ultraviolet transmission resistance and ultraviolet appearance retention, and from the viewpoint of forming a coating film having excellent water resistance, freeze-thaw repeated stability and transparency. It is 0% by mass or more, preferably 0.5% by mass or more, more preferably 1% by mass or more, still more preferably 1.5% by mass or more, and has excellent ultraviolet transmission resistance and ultraviolet appearance retention, water resistance, and freezing. From the viewpoint of forming a coating film having excellent melting stability and transparency, it is preferably 5% by mass or less, more preferably 4% by mass or less, and further preferably 3% by mass or less.

Examples of the aromatic monomer include styrene, α-methylstyrene, p-methylstyrene, tert-methylstyrene, chlorostyrene, aralkyl (meth) acrylate, vinyltoluene and the like. It is not limited to illustrations only. Examples of the aralkyl (meth) acrylate include benzyl (meth) acrylate, phenylethyl (meth) acrylate, methylbenzyl (meth) acrylate, and naphthylmethyl (meth) acrylate, which have an aralkyl group having 7 to 18 carbon atoms. Examples thereof include (meth) acrylate, but the present invention is not limited to such examples. These aromatic monomers may be used alone or in combination of two or more.

Examples of the carboxyl group-containing monomer include carboxyl group-containing aliphatic monomers such as (meth) acrylic acid, maleic acid, fumaric acid, crotonic acid, itaconic acid, and maleic anhydride. The invention is not limited to such embodiments. These carboxyl group-containing monomers may be used alone or in combination of two or more.

Examples of the nitrogen atom-containing monomer include (meth) acrylamide, diacetone (meth) acrylamide, N-monomethyl (meth) acrylamide, N-monoethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, and N. -N-propyl (meth) acrylamide, N-isopropyl (meth) acrylamide, methylenebis (meth) acrylamide, N-methylol (meth) acrylamide, N-butoxymethyl (meth) acrylamide, dimethylaminoethyl (meth) acrylamide, N, (Meta) acrylamide compounds such as N-dimethylaminopropyl (meth) acrylamide and diacetone (meth) acrylamide, nitrogen atom-containing (meth) acrylate compounds such as dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylate, N- Examples thereof include vinylpyrrolidone and (meth) acrylamide, but the present invention is not limited to such examples. These nitrogen atom-containing monomers may be used alone or in combination of two or more.

Examples of the oxo group-containing monomer include (di) ethylene glycol (methoxy) (meth) such as ethylene glycol (meth) acrylate, ethylene glycol methoxy (meth) acrylate, diethylene glycol (meth) acrylate, and diethylene glycol methoxy (meth) acrylate. ) Acrylate and the like, but the present invention is not limited to such examples. These oxo group-containing monomers may be used alone or in combination of two or more.

Examples of the fluorine atom-containing monomer include a fluorine atom-containing alkyl having 2 to 6 carbon atoms in an ester group such as trifluoroethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, and octafluoropentyl (meth) acrylate. Examples thereof include (meth) acrylate, but the present invention is not limited to such examples. These fluorine atom-containing monomers may be used alone or in combination of two or more.

Examples of the epoxy group-containing monomer include epoxy group-containing (meth) acrylates such as glycidyl (meth) acrylate, but the present invention is not limited to these examples. These epoxy group-containing monomers may be used alone or in combination of two or more.

Examples of the ultraviolet-absorbing monomer include benzotriazole-based ultraviolet-absorbing monomers and benzophenone-based ultraviolet-absorbing monomers, but the present invention is not limited to these examples. These ultraviolet-absorbing monomers may be used alone or in combination of two or more.

Examples of the benzotriazole-based ultraviolet absorbing monomer include 2- [2'-hydroxy-5'-(meth) acryloyloxymethylphenyl] -2H-benzotriazole and 2- [2'-hydroxy-5'-. (Meta) acryloyloxyethylphenyl] -2H-benzotriazole, 2- [2'-hydroxy-5'-(meth) acryloyloxymethylphenyl] -5-tert-butyl-2H-benzotriazole, 2- [2' -Hydroxy-5'-(meth) acryloylaminomethyl-5'-tert-octylphenyl] -2H-benzotriazole, 2- [2'-hydroxy-5'-(meth) acryloyloxypropylphenyl] -2H-benzo Triazole, 2- [2'-hydroxy-5'-(meth) acryloyloxyhexylphenyl] -2H-benzotriazole, 2- [2'-hydroxy-3'-tert-butyl-5'-(meth) acryloyloxy Ethylphenyl] -2H-benzotriazole, 2- [2'-hydroxy-3'-tert-butyl-5'-(meth) acryloyloxyethylphenyl] -5-chloro-2H-benzotriazole, 2- [2' -Hydroxy-5'-tert-butyl-3'-(meth) acryloyloxyethylphenyl] -2H-benzotriazole, 2- [2'-hydroxy-5'-(meth) acryloyloxyethylphenyl] -5-chloro -2H-benzotriazole, 2- [2'-hydroxy-5'-(meth) acryloyloxyethylphenyl] -5-cyano-2H-benzotriazole, 2- [2'-hydroxy-5'-(meth) acryloyl Oxyethylphenyl] -5-tert-butyl-2H-benzotriazole, 2- [2'-hydroxy-5'-(β- (meth) acryloyloxyethoxy) -3'-tert-butylphenyl] -4-tert -Butyl-2H-benzotriazole and the like can be mentioned, but the present invention is not limited to such examples. These benzotriazole-based ultraviolet absorbing monomers may be used alone or in combination of two or more.

Examples of the benzophenone-based ultraviolet absorbing monomer include 2-hydroxy-4- (meth) acryloyloxybenzophenone, 2-hydroxy-4- [2-hydroxy-3- (meth) acryloyloxy] propoxybenzophenone, 2-. Hydroxy-4- [2- (meth) acryloyloxy] ethoxybenzophenone, 2-hydroxy-4- [3- (meth) acryloyloxy-2-hydroxypropoxy] benzophenone, 2-hydroxy-3-tert-butyl-4- [2- (Meta) acryloyloxy] butoxybenzophenone and the like can be mentioned, but the present invention is not limited to these examples. These benzophenone-based ultraviolet absorbing monomers may be used alone or in combination of two or more.

Examples of the photostable monomer other than the polymerizable hindered amine-based photostable monomer include bisdecanoate (2,2,6,6-tetramethyl-1- (octyloxy) -4-piperidinyl). Reaction product of ester, 1,1-dimethylethyl hydroperoxide and octane, bis (1,2,2,6,6-pentamethyl-4-piperidyl) [[3,5-bis (1,1-dimethylethyl) ) -4-Hydroxyphenyl] methyl] butyl malonate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and methyl 1,2,2,6,6-pentamethyl-4-piperidyl seva Examples thereof include a mixture with Kate, but the present invention is not limited to such examples. The photostable monomers other than these polymerizable hindered amine-based photostable monomers may be used alone or in combination of two or more.

The content of other monomers in the monomer component is preferable from the viewpoint of forming a coating film having excellent ultraviolet transmittance and ultraviolet appearance retention, water resistance, repeated freeze-thaw stability, and transparency. Is 75% by mass or more, more preferably 80% by mass or more, still more preferably 85% by mass or more, and is excellent in UV transmission resistance and UV appearance retention, water resistance, freeze-thaw repeated stability and transparency. From the viewpoint of forming a coating film, it is preferably 99.9% by mass or less, more preferably 99.7% by mass or less, and further preferably 99.5% by mass or less.

As a method of emulsion polymerization of the monomer component, for example, an emulsifier is dissolved in an aqueous medium containing water and a water-soluble organic solvent such as a lower alcohol such as methanol and a medium such as water, and a single amount is obtained under heating and stirring. Examples thereof include a method of dropping a body component and a polymerization initiator, a method of dropping a monomer component pre-emulsified with an emulsifier and water onto water or an aqueous medium, and the like. It is not limited. The amount of the medium may be appropriately set in consideration of the non-volatile content contained in the obtained resin emulsion.

Examples of the emulsifier include anionic emulsifiers, nonionic emulsifiers, cationic emulsifiers, amphoteric emulsifiers, and polymer emulsifiers, and these emulsifiers may be used alone or in combination of two or more.

Examples of the anionic emulsifier include alkyl sulphate salts such as ammonium dodecyl sulphate and sodium dodecyl sulphate; alkyl sulfonate salts such as ammonium dodecyl sulphonate and sodium dodecyl sulphonate; alkylaryl sulphonate salts such as ammonium dodecylbenzene sulphonate and sodium dodecyl naphthalene sulphonate; Examples thereof include polyoxyethylene alkyl sulfate salts; polyoxyethylene alkyl aryl sulfate salts; dialkyl sulfosuccinates; aryl sulfonic acid-formalin condensates; and fatty acid salts such as ammonium laurylate and sodium stearylate. It is not limited to just an example.

Examples of the nonionic emulsifier include polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether, condensate of polyethylene glycol and polypropylene glycol, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, fatty acid monoglyceride, ethylene oxide and aliphatic. Examples thereof include a condensate with an amine, but the present invention is not limited to such examples.

Examples of the cationic emulsifier include alkylammonium salts such as dodecylammonium chloride, but the present invention is not limited to these examples.

Examples of the amphoteric emulsifier include betaine ester type emulsifiers, but the present invention is not limited to these examples.

Examples of the polymer emulsifier include poly (meth) acrylates such as sodium polyacrylate; polyvinyl alcohol; polyvinylpyrrolidone; and polyhydroxyalkyl (meth) acrylates such as polyhydroxyethyl acrylate; Examples thereof include polymers containing one or more types of monomers as copolymerization components, but the present invention is not limited to these examples.

Further, as the emulsifier, an emulsifier having a polymerizable group, that is, a so-called emulsifier, is obtained from the viewpoint of forming a coating film having excellent ultraviolet transmission resistance and ultraviolet appearance retention, water resistance, repeated freeze-thaw stability and transparency. A reactive emulsifier is preferable, and a non-nonylphenyl type emulsifier is preferable from the viewpoint of environmental protection.

Examples of the reactive emulsifier include propenyl-alkylsulfosuccinate salt, (meth) acrylate polyoxyethylene sulfonate salt, and polyoxyethylene alkylpropenylphenyl ether ammonium sulfate [for example, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10, Aqualon BC-10, etc.], Alkoxymethylalkyloxypolyoxyethylene sulfonate salt [for example, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon KH-10, etc.], Allyloxymethylnonylphenoxy Ethylhydroxypolyoxyethylene sulfonate salt [for example, manufactured by ADEKA Co., Ltd., trade name: Adecaria Soap SE-10, etc.], allyloxymethylalkoxyethyl hydroxypolyoxyethylene sulfate ester salt [for example, manufactured by ADEKA Co., Ltd., Product name: Adecaria soap SR-10, SR-30, etc.], Bis (polyoxyethylene polycyclic phenyl ether) methacrylated sulfonate salt [For example, manufactured by Nippon Emulsifier Co., Ltd., product name: Antox MS-60, etc.] , Allyloxymethylalkoxyethyl hydroxypolyoxyethylene [for example, manufactured by ADEKA Co., Ltd., trade name: Adecaria Soap ER-20, etc.], polyoxyethylene alkylpropenylphenyl ether [for example, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Product name: Aqualon RN-20, etc.], Allyloxymethylnonylphenoxyethyl hydroxypolyoxyethylene [For example, manufactured by ADEKA Co., Ltd., Product name: Adecaria Soap NE-10, etc.] It is not limited to such an example. Each of these reactive emulsifiers may be used alone or in combination of two or more.

The amount of the emulsifier per 100 parts by mass of the monomer component is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, still more preferably 2 parts by mass or more, from the viewpoint of improving the polymerization stability. From the viewpoint of forming a coating film having excellent UV transmission resistance and UV appearance retention, water resistance, freeze-thaw repeated stability and transparency, it is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and further. It is preferably 5 parts by mass or less.

When polymerizing the monomer component, a polymerization initiator can be used. Examples of the polymerization initiator include azobisisobutyronitrile, 2,2-azobis (2-methylbutyronitrile), 2,2-azobis (2,4-dimethylvaleronitrile), and 2,2-azobis (2,2-azobis). 2-Diaminopropane) Hydrochloride, azo compounds such as 4,4-azobis (4-cyanovaleric acid), 2,2-azobis (2-methylpropionamidine); persulfates such as potassium persulfate and ammonium persulfate; Examples thereof include peroxides such as hydrogen peroxide, benzoyl peroxide, parachlorobenzoyl peroxide, lauroyl peroxide, and ammonium peroxide, but the present invention is not limited to these examples. These polymerization initiators may be used alone or in combination of two or more.

The amount of the polymerization initiator per 100 parts by mass of the monomer component is preferably 0.01 part by mass or more, more preferably 0, from the viewpoint of increasing the polymerization rate and reducing the residual amount of the unreacted monomer component. From the viewpoint of forming a coating film having .03 parts by mass or more, excellent in ultraviolet transmission resistance and ultraviolet appearance retention, water resistance, repeated freeze-thaw stability, and transparency, it is preferably 5 parts by mass or less. It is preferably 3 parts by mass or less.

The method of adding the polymerization initiator is not particularly limited. Examples of the addition method include batch preparation, split preparation, continuous dropping and the like. Further, from the viewpoint of accelerating the end time of the polymerization reaction, a part of the polymerization initiator may be added into the flask before or after the completion of adding the monomer component into the reaction system.

In order to promote the decomposition of the polymerization initiator, for example, a reducing agent such as sodium bisulfite and a decomposition agent of the polymerization initiator such as a transition metal salt such as ferrous sulfate are added in an appropriate amount into the reaction system. May be good.

Further, if necessary, an appropriate amount of a chain transfer agent such as a compound having a thiol group such as tert-dodecyl mercaptan, a pH buffer, or a chelating agent may be added to the reaction system. good. The amount of the additive varies depending on the type and cannot be unconditionally determined, but is usually preferably 0.01 to 5 parts by mass, more preferably 0.1 to 3 parts per 100 parts by mass of the monomer component. It is a mass part.

The atmosphere when the monomer component is emulsion-polymerized is not particularly limited, but is preferably an inert gas such as nitrogen gas from the viewpoint of increasing the efficiency of the polymerization initiator.

The polymerization temperature at the time of emulsion polymerization of the monomer component is not particularly limited, but is usually preferably 50 to 100 ° C, more preferably 60 to 95 ° C. The polymerization temperature may be constant or may be changed during the polymerization reaction.

The polymerization time for emulsion polymerization of the monomer component is not particularly limited and may be appropriately set according to the progress of the polymerization reaction, but is usually about 2 to 9 hours.

By emulsion polymerization of the monomer component (hereinafter referred to as "the monomer component") as described above, a resin emulsion containing emulsion particles can be obtained.

The polymer constituting the emulsion particles may have a crosslinked structure. The weight average molecular weight of the polymer is preferably 100,000 or more, more preferably 100,000 or more, from the viewpoint of forming a coating film having excellent ultraviolet transparency and ultraviolet appearance retention, water resistance, repeated freeze-thaw stability, and transparency. Is 300,000 or more, more preferably 550,000 or more, and particularly preferably 600,000 or more. The upper limit of the weight average molecular weight of the polymer is not particularly limited because it is difficult to measure the weight average molecular weight when it has a crosslinked structure, but when it does not have a crosslinked structure, the film-forming property is improved. From the viewpoint, it is preferably 5 million or less.

In the present specification, the weight average molecular weight of the polymer is gel permeation chromatography [manufactured by Toso Co., Ltd., product number: HLC-8120GPC, column: TSKgel G-5000HXL and TSKgel GMHXL-L are used in series. ] Means the weight average molecular weight (in terms of polystyrene) measured using.

The emulsion particles contained in the resin emulsion of the present invention may have a single-layer resin layer prepared by one-stage emulsion polymerization, or may have a plurality of resin layers prepared by multi-stage emulsion polymerization. May be. Among these emulsion particles, having a plurality of resin layers is excellent in ultraviolet transmission resistance and ultraviolet appearance retention, and from the viewpoint of forming a coating film excellent in water resistance, freeze-thaw repeated stability and transparency. preferable. When the emulsion particles have a plurality of resin layers, the boundary between the resin layers does not necessarily have to be clear, and the adjacent resin layers may be mixed with each other.

The number of resin layers constituting the emulsion particles is preferably 1 to 5 from the viewpoint of forming a coating film having excellent ultraviolet transparency and ultraviolet appearance retention, water resistance, repeated freeze-thaw stability, and transparency. Layers, more preferably 1-3 layers, even more preferably 2 and 3 layers.

Further, among the emulsion particles having a plurality of resin layers, the emulsion is excellent in ultraviolet transmission resistance and ultraviolet appearance retention, and from the viewpoint of forming a coating film excellent in water resistance, freeze-thaw repeated stability and transparency. Of the resin layers constituting the particles, emulsion particles having the resin layer having the highest glass transition temperature in the inner layer rather than the outermost layer are preferable.

Emulsion particles having a single resin layer can be prepared by emulsion polymerization of the monomer component. Further, the emulsion particles having a plurality of resin layers can be prepared by multi-stage emulsion polymerization of the monomer component under the same polymerization method and polymerization conditions as in the case of emulsion polymerization of the monomer component.

When the emulsion particles have a plurality of resin layers, the monomer component forming each layer has excellent ultraviolet transmission resistance and ultraviolet appearance retention, and a coating film having excellent water resistance, freeze-thaw repeated stability and transparency. From the viewpoint of formation, it is preferable to contain each of the triazine-based ultraviolet absorbers.

The emulsion particle having two resin layers, an inner layer and an outer layer, emulsion-polymerizes the monomer component forming the inner layer and emulsion-polymerizes the monomer component forming the outer layer in the presence of the obtained emulsion particles. Can be prepared by In this case, the monomer component forms an inner layer and an outer layer from the viewpoint of forming a coating film having excellent ultraviolet transmission resistance and ultraviolet appearance retention, water resistance, repeated freeze-thaw stability and transparency. It is preferably used as a monomer component. The mass ratio of the resin layer that constitutes the inner layer to the resin layer that constitutes the outer layer (the resin layer that constitutes the inner layer / the resin layer that constitutes the outer layer) is UV-transmissive and retains the appearance of UV rays. From the viewpoint of forming a coating film having excellent properties, water resistance, repeated freeze-thaw stability, and transparency, it is preferably 10/90 or more, more preferably 20/80 or more, and further preferably 30/70 or more. From the viewpoint of improving film forming property, adhesion and blocking resistance, it is preferably 80/20 or less, more preferably 70/30 or less.

The emulsion particle having three resin layers of an inner layer, an intermediate layer and an outer layer is a monomer component that forms an intermediate layer in the presence of the obtained emulsion particles by emulsion polymerization of the monomer component forming the inner layer. Can be prepared by emulsion polymerization of the above, and emulsion polymerization of the monomer component forming the outer layer in the presence of the obtained emulsion particles. In this case, the monomer component is excellent in ultraviolet transmission resistance and ultraviolet appearance retention, and from the viewpoint of forming a coating film excellent in water resistance, freeze-thaw repeat stability and transparency, the inner layer, the intermediate layer and the outer layer are formed. It is preferable that it is used as a monomer component that forms. Further, from the viewpoint of forming a coating film having excellent ultraviolet transparency and ultraviolet appearance retention, water resistance, repeated freeze-thaw stability and transparency, the content of the resin layer constituting the inner layer is 10 to 10. It is preferably 40% by mass, the content of the resin layer constituting the intermediate layer is 20 to 60% by mass, and the content of the resin layer constituting the outer layer is 20 to 60% by mass.

In the emulsion particles having a single resin layer, the glass transition temperature of the resin layer is excellent in ultraviolet transmission resistance and ultraviolet appearance retention, and forms a coating film excellent in water resistance, freeze-thaw repeated stability and transparency. From the viewpoint of

From the viewpoint of forming a coating film having two resin layers, an inner layer and an outer layer, which are excellent in ultraviolet transmission resistance and ultraviolet appearance retention, water resistance, repeated freeze-thaw stability, and transparency, from the viewpoint of forming a coating film. The glass transition temperature of the resin layer constituting the inner layer is preferably -20 to 150 ° C., more preferably -10 to 110 ° C., and the glass transition temperature of the resin layer constituting the outer layer is preferably − It is 50 to 70 ° C, more preferably -40 to 60 ° C.

In emulsion particles having three resin layers, an inner layer, an intermediate layer, and an outer layer, a coating film having excellent ultraviolet transmission resistance and ultraviolet appearance retention, water resistance, repeated freeze-thaw stability, and transparency is formed. From the viewpoint, the glass transition temperature of the resin layer constituting the inner layer is preferably 50 to 150 ° C., more preferably 80 to 110 ° C., and the glass transition temperature of the resin layer constituting the intermediate layer is preferable. Is −50 to 0 ° C., more preferably −30 to −10 ° C., and the glass transition temperature of the resin layer constituting the outer layer is preferably 0 to 50 ° C., more preferably 10 to 40 ° C.

Further, the glass transition temperature of the entire emulsion particle having a plurality of resin layers is excellent in ultraviolet transmission resistance and ultraviolet appearance retention, and from the viewpoint of forming a coating film excellent in water resistance, freeze-thaw repeated stability and transparency. It is preferably −10 ° C. or higher, more preferably −5 ° C. or higher, further preferably 0 ° C. or higher, preferably 50 ° C. or lower, more preferably 45 ° C. or lower, still more preferably 40 ° C. or lower.

The glass transition temperature of the resin layer constituting the emulsion particles can be easily adjusted by adjusting the type and amount of the monomer used as the monomer component.

In the present specification, the glass transition temperature of the resin layer constituting the emulsion particles is the glass transition temperature of the monomer homopolymer used for the monomer component constituting the resin layer. formula:
1 / Tg = Σ (Wm / Tgm) / 100
[In the formula, Wm indicates the content (% by mass) of the monomer m in the monomer component constituting the polymer, and Tgm indicates the glass transition temperature (absolute temperature: K) of the homopolymer of the monomer m. ]
It means the temperature obtained based on the Fox formula represented by.

In the present specification, the glass transition temperature of the resin layer constituting the emulsion particles means the glass transition temperature obtained based on the Fox formula unless otherwise specified. The glass transition temperature of the entire resin layer constituting the emulsion particles having a plurality of resin layers is the monomer used for all the monomer components constituting all the resin layers used in the multi-stage emulsion polymerization. The glass transition temperature of the homopolymer is used to mean the glass transition temperature obtained based on the Fox equation. For monomers such as special monomers and polyfunctional monomers whose glass transition temperature is unknown, the total amount of the monomers whose glass transition temperature is unknown in the monomer component is the mass fraction. When it is 10% by mass or less, the glass transition temperature can be obtained by using only the monomer whose glass transition temperature is known. When the total amount of monomers whose glass transition temperature is unknown in the monomer component exceeds 10% by mass in terms of mass, the glass transition temperature of the polymer is determined by differential scanning calorimetry (DSC) or differential calorimetry. Obtained by (DTA), thermomechanical analysis (TMA), etc.

The glass transition temperature of the resin layer can be easily adjusted by adjusting the composition of the monomer component. The composition of the monomer component used as a raw material of the resin layer constituting the emulsion particles can be determined in consideration of the glass transition temperature of the resin layer constituting the emulsion particles.

The glass transition temperature of the polymer is, for example, 105 ° C for the methyl methacrylate homopolymer, 100 ° C for the styrene homopolymer, 83 ° C for the cyclohexyl methacrylate homopolymer, and -70 for the 2-ethylhexyl acrylate homopolymer. ° C., -56 ° C for the homopolymer of n-butyl acrylate, 20 ° C for the homopolymer of n-butyl methacrylate, 55 ° C for the homopolymer of 2-hydroxyethyl methacrylate, 95 ° C for the homopolymer of acrylic acid, 130 ° C for homopolymer of methacrylic acid, 130 ° C for homopolymer of 4-methacryloyloxy-1,2,2,6,6-pentamethylpiperidin, 70 for homopolymer of γ-methacryloyloxypropyltrimethoxysilane ℃.

When the emulsion particles are composed of a plurality of resin layers, the solubility parameter of the resin layer constituting the outer layer (hereinafter, also referred to as SP value) is higher than the SP value of the resin layer constituting the inner layer. A high value is preferable from the viewpoint of improving the flexibility and film-forming property of the coating film. Further, the difference (absolute value) between the SP value of the resin layer constituting the inner layer and the SP value of the resin layer constituting the outer layer may be large from the viewpoint of forming a layer-separated structure in the emulsion particles. preferable.

The SP value is a value defined by the regular solution theory introduced by Hildebrand, and is also a measure of the solubility of a two-component solution. In general, substances having similar SP values tend to be easily mixed with each other. Therefore, the SP value is also a guide for determining the ease of mixing the solute and the solvent.

The average particle size of the emulsion particles is preferably 30 nm or more, more preferably 50 nm or more from the viewpoint of improving the mechanical stability of the emulsion particles themselves, and is excellent in ultraviolet transmission resistance and ultraviolet appearance retention, and water resistance. From the viewpoint of forming a coating film excellent in freeze-thaw repeated stability and transparency, it is preferably 300 nm or less, more preferably 200 nm or less.

In the present specification, the average particle size of the emulsion particles is measured using a particle size distribution measuring device [Particle Sizing Systems, trade name: NICOMP Model 380] by a dynamic light scattering method. It means the volume average particle size obtained.

The resin emulsion of the present invention includes, for example,
(1) A resin emulsion obtained by emulsion polymerization of a monomer component containing a triazine-based ultraviolet absorber and containing emulsion particles containing a triazine-based ultraviolet absorber.
(2) Examples thereof include a resin emulsion containing emulsion particles obtained by emulsion polymerization of the monomer component and a resin emulsion obtained by mixing a triazine-based ultraviolet absorber. It is not limited to illustrations only. Among these resin emulsions, a resin emulsion containing emulsion particles containing a triazine-based ultraviolet absorber is preferable from the viewpoint of forming a coating film having excellent ultraviolet transmission resistance and ultraviolet appearance retention.

The total content of the non-volatile components of the emulsion particles and the triazine-based ultraviolet absorber in the resin emulsion of the present invention is preferably 30% by mass or more, more preferably 40% by mass or more, and is easy to handle, from the viewpoint of improving productivity. From the viewpoint of improving the above, it is preferably 70% by mass or less, more preferably 60% by mass or less.

The total content of the non-volatile content in the resin emulsion was determined by weighing 1 g of the resin emulsion, drying it in a hot air dryer at a temperature of 110 ° C. for 1 hour, and using the obtained residue as the non-volatile content.
[Total content of non-volatile components in resin emulsion (mass%)]
= ([Mass of residue] ÷ [Resin emulsion 1 g]) × 100
Means the value obtained based on.

Further, the minimum film-forming temperature of the resin emulsion of the present invention is preferably from the viewpoint of forming a coating film having excellent ultraviolet transmission resistance and ultraviolet appearance retention, water resistance, repeated freeze-thaw stability and transparency. It is 100 ° C. or lower, more preferably 70 ° C. or lower. The minimum film-forming temperature of the resin emulsion can be adjusted, for example, by adjusting the glass transition temperature of the entire emulsion particles or the glass transition temperature of the outermost resin layer.

In the present specification, the minimum film forming temperature of the resin emulsion is such that the resin emulsion is coated on a glass plate placed on a thermal gradient tester with an applicator so as to have a thickness of 0.2 mm, and cracks are generated. It means the temperature when it occurs.

If necessary, the resin emulsion of the present invention obtained as described above may contain, for example, a cross-linking agent. Examples of the cross-linking agent include a melamine-based cross-linking agent, an oxazoline-based cross-linking agent, an acrylamide-based cross-linking agent, a polyamide-based cross-linking agent, an epoxy-based cross-linking agent, an isocyanate-based cross-linking agent, an aziridine-based cross-linking agent, a titanate-based cross-linking agent, and a urea-based cross-linking agent. Agents, alkylalcoholic urea-based cross-linking agents, hydrazine compounds, carbodiimide compounds, zirconium compounds, zinc compounds, titanium compounds, aluminum compounds and other polyvalent metal compounds can be mentioned, but the present invention is limited to these examples only. It's not a thing. These cross-linking agents may be used alone or in combination of two or more. The amount of the cross-linking agent is preferably set as appropriate according to the type of the cross-linking agent and the like. Among the cross-linking agents, oxazoline-based cross-linking agents and hydrazine-based cross-linking agents are selected from the viewpoint of forming a coating film having excellent UV transmission resistance and UV appearance retention, water resistance, repeated freeze-thaw stability and transparency. preferable.

Examples of the oxazoline-based cross-linking agent include 2,2'-bis (2-oxazoline), 1,2-bis (2-oxazoline-2-yl) ethane, and 1,4-bis (2-oxazoline-2-yl). ) Butane, 1,8-bis (2-oxazoline-2-yl) butane, 1,4-bis (2-oxazoline-2-yl) cyclohexane, 1,2-bis (2-oxazoline-2-yl) benzene , 1,3-Bis (2-oxazoline-2-yl) benzene, 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2 -Isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline and the like can be mentioned, but the present invention is limited to such examples. It's not a thing. These oxazoline-based cross-linking agents may be used alone or in combination of two or more. The oxazoline-based cross-linking agent can be easily obtained commercially. For example, Nippon Shokubai Co., Ltd., trade names: Epocross WS-500, Epocross WS-700, Epocross K-2010, Epocross K- 2020, Epocross K-2030 and the like can be mentioned, but the present invention is not limited to such examples.

Examples of the hydrazine-based cross-linking agent include adipic acid dihydrazide and a polymer having a dihydrazide group, but the present invention is not limited to these examples. Each of these compounds may be used alone, or two or more kinds may be used in combination.

The resin emulsion of the present invention forms a coating film having excellent ultraviolet transmission resistance and ultraviolet appearance retention, water resistance, repeated freeze-thaw stability, and transparency. Therefore, for example, building exteriors and ceramic building materials. It can be suitably used for a topcoat paint called a top coat to be applied to the surface of the above.

The topcoat coating material of the present invention contains the resin emulsion of the present invention. The total content of the emulsion particles and the non-volatile content of the triazine-based UV absorber in the solid content of the topcoat coating material of the present invention is excellent in UV transmission resistance and UV appearance retention, water resistance, freeze-thaw repeated stability and transparency. From the viewpoint of forming a coating film having excellent properties, it is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, and the upper limit value is 100% by mass.

The topcoat coating material of the present invention may contain only the resin emulsion of the present invention, and may contain, for example, pigments, additives and the like, if necessary.

Examples of the pigment include organic pigments and inorganic pigments, and these pigments may be used alone or in combination of two or more.

Examples of organic pigments include azo pigments, azomethine pigments, methine pigments, anthraquinone pigments, phthalocyanine pigments, perinone pigments, perylene pigments, diketopyrrolopyrrole pigments, thioindigo pigments, iminoisoindrin pigments, iminoisoindolinone pigments, and quinacridone red. Quinacridone pigments such as quinacridone violet, flavantron pigments, indantron pigments, anthrapyrimidine pigments, carbazole pigments, monoallylide yellow, theallyride yellow, benzoimidazolone yellow, trill orange, naphthol orange, quinophthalone pigments, etc. However, the present invention is not limited to such an example. These organic pigments may be used alone or in combination of two or more.

Examples of inorganic pigments include titanium dioxide, red iron oxide, black iron oxide, iron oxide, chromium oxide green, carbon black, ferrous ferrocyanide (Prussian blue), ultramarine, lead chromate, and mica. Examples thereof include flat pigments such as (mica), clay, aluminum powder, talc, and aluminum silicate, and extender pigments such as calcium carbonate, magnesium hydroxide, aluminum hydroxide, barium sulfate, and magnesium carbonate. Is not limited to such examples. These inorganic pigments may be used alone or in combination of two or more.

The solid content of the pigment in the topcoat coating material of the present invention is 0% by mass or more, but is preferably 3% by mass from the viewpoint of increasing the coating film hardness and improving the design or hiding property of the formed coating film. As described above, it is more preferably 5% by mass or more, and from the viewpoint of improving the film-forming property, it is preferably 50% by mass or less, more preferably 40% by mass or less.

The solid content of the pigment in the top coat of the present invention is based on the formula:
[Solid content of pigment in topcoat paint (mass%)]
= [(Pigment solid content) / (Resin emulsion solid content + Pigment solid content)] × 100
Means the value obtained based on.

Additives include, for example, aggregates, leveling agents, antioxidants, polymerization inhibitors, fillers, coupling agents, rust inhibitors, antibacterial agents, metal deactivators, wetting agents, defoaming agents, surfactants. Agents, reinforcing agents, plasticizers, lubricants, antifogging agents, anticorrosive agents, pigment dispersants, flow conditioners, peroxide decomposing agents, mold decolorizing agents, fluorescent whitening agents, organic flame retardants, inorganic flame retardants Agents, anti-dripping agents, melt flow modifiers, anti-static agents, algae-proofing agents, anti-mold agents, flame retardants, slip agents, metal chelating agents, anti-blocking agents, heat-resistant stabilizers, processing stabilizers, dispersants, Examples thereof include thickeners, rheology control agents, foaming agents, antiaging agents, preservatives, antistatic agents, silane coupling agents, antioxidants, etc., but the present invention is not limited to these examples. .. These additives may be used alone or in combination of two or more.

Since the amount of the additive varies depending on the type of the additive and cannot be unconditionally determined, it is preferable to appropriately determine the amount according to the type of the additive.

The content of the total non-volatile content in the topcoat coating material of the present invention varies depending on the use of the topcoat coating material of the present invention and therefore cannot be unconditionally determined, but is usually preferably 10 to 70% by mass.

The topcoat coating material of the present invention can be easily prepared, for example, by mixing the resin emulsion of the present invention, and if necessary, pigments, additives, water and the like.

Since the topcoat coating material of the present invention obtained as described above contains the resin emulsion of the present invention, it is excellent in UV transmission resistance and UV appearance retention, water resistance, freeze-thaw repeated stability and transparency. Since it forms a coating film, it can be suitably used for surface finishing of a base material made of a material such as metal, glass, porcelain, concrete, siding board, or resin. Therefore, the topcoat paint of the present invention can be suitably used as a topcoat paint called a top coat, which is applied to the surface of a building exterior, a ceramic building material, or the like.

Examples of ceramic building materials include roof tiles and outer wall materials. Ceramic building materials are made by adding an inorganic filler, fibrous material, etc. to a hydraulic adhesive that is a raw material for an inorganic cured product, molding the obtained mixture, curing the obtained molded product, and curing it. can get. Examples of the inorganic building material constituting the exterior of the building include flexible board, calcium silicate board, gypsum slag perlite board, wood piece cement board, precast concrete board, ALC board, gypsum board and the like.

The surface of such a building material is usually coated with a topcoat paint in order to impart a desired design. The topcoat paint of the present invention can be suitably used for this topcoat paint.

The top coat coating material of the present invention may be applied by itself in one layer, or may be applied by applying two or more layers in layers. When coating by overcoating two or more layers, only a part of the layers may be formed by the topcoat paint of the present invention, or all the layers may be formed by the topcoat paint of the present invention. The recoating is performed, for example, by applying a coating material for the first layer (for example, an undercoat layer) to an object to be coated, which has been subjected to a primer treatment or a sealer treatment, and drying the material, and then for the second layer (for example, a topcoat layer). Examples thereof include a method of overcoating and drying the paint, but the present invention is not limited to such a method. Examples of the method for applying the top coat of the present invention include a coating method using a brush, a bar coater, an applicator, an air spray, an airless spray, a roll coater, a flow coater, etc. It is not limited to.

The coating film formed by using the top coat coating material of the present invention may be dried at room temperature, for example, or may be dried by heating.

Further, the thickness of the coating film formed by using the topcoat coating material of the present invention after drying is excellent in ultraviolet transmission resistance and ultraviolet appearance retention, and excellent in water resistance, freeze-thaw repeated stability and transparency. From the viewpoint of forming a film, it is usually preferably about 1 to 100 μm.

The amount of the topcoat paint applied to the base material varies depending on the type of the base material, etc., so it cannot be unconditionally determined. From the viewpoint of forming a coating film having excellent transparency, the non-volatile content is usually preferably about ^{10 to 200 g / m 2.}

Next, the present invention will be described in more detail based on Examples, but the present invention is not limited to such Examples. In the following, unless otherwise specified, "part" means "part by mass".

Example 1
716 parts of deionized water was placed in a flask equipped with a dropping funnel, a stirrer, a nitrogen gas introduction tube, a thermometer and a reflux condenser. 417 parts of deionized water, 120 parts of 25% aqueous solution of emulsifier [manufactured by ADEKA Co., Ltd., trade name: Adecaria Sorb SR-10], 290 parts of methyl methacrylate, 250 parts of cyclohexyl methacrylate, 2-ethylhexyl as monomer components in the dropping funnel. 200 parts of acrylate, 200 parts of n-butyl acrylate, 20 parts of hydroxyethyl methacrylate and 30 parts of 4-methacryloyloxy-1,2,2,6,6-pentamethylpiperidin, and triazine-based per 100 parts of the monomer component. A pre-emulsion for dropping containing 10 parts of a triazine-based ultraviolet absorber [manufactured by BASF Japan Co., Ltd., trade name: TINUVIN400] so that the amount of the ultraviolet absorber is 1 part was prepared, and a monomer component thereof was prepared. Add 154 parts, which is 10% of the total amount of the triazine-based ultraviolet absorber, into the flask, raise the temperature to 80 ° C while gently blowing nitrogen gas, add 10 parts of a 5% ammonium persulfate aqueous solution, and start polymerization. bottom. Then, the rest of the pre-emulsion for dropping and 30 parts of a 5% ammonium persulfate aqueous solution were uniformly dropped into the flask over 240 minutes.

After completion of the dropping, the contents of the flask were maintained at 80 ° C. for 60 minutes, the pH was adjusted to 8 by adding 25% aqueous ammonia, and the polymerization was completed. The obtained reaction solution was cooled to room temperature and then filtered through a wire mesh of 300 mesh (JIS mesh, the same applies hereinafter) to prepare a resin emulsion. Table 1 shows the compositions of the monomer component and the triazine-based ultraviolet absorber used as the resin raw material of the obtained resin emulsion.

Example 2
716 parts of deionized water was placed in a flask equipped with a dropping funnel, a stirrer, a nitrogen gas introduction tube, a thermometer and a reflux condenser. 209 parts of deionized water, 60 parts of 25% aqueous solution of emulsifier [manufactured by ADEKA Co., Ltd., trade name: Adecaria Soap SR-10], 307.5 parts of methyl methacrylate as a monomer component, 125 parts of cyclohexyl methacrylate in a full funnel. 40 parts of 2-ethylhexyl acrylate, 10 parts of hydroxyethyl methacrylate and 15 parts of 4-methacryloyloxy-1,2,2,6,6-pentamethylpiperidin, and absorption of triazine-based ultraviolet rays per 100 parts of all monomer components. A preemulsion for first-stage dropping was prepared containing 2.5 parts of a triazine-based ultraviolet absorber [manufactured by BASF Japan Co., Ltd., trade name: TINUVIN400] so that the amount of the agent was 0.5 parts. 77 parts, which is 10% of the total amount of the monomer component and the triazine-based ultraviolet absorber, is added into the flask, the temperature is raised to 80 ° C. while gently blowing nitrogen gas, and 10 parts of a 5% ammonium persulfate aqueous solution is added. Then, polymerization was started. Then, the rest of the pre-emulsion for dropping and 15 parts of a 5% ammonium persulfate aqueous solution were uniformly dropped into the flask over 120 minutes.

After completion of the dropping, the contents of the flask were maintained at 80 ° C. for 60 minutes, followed by 209 parts of deionized water, 60 parts of a 25% aqueous solution of an emulsifier [manufactured by ADEKA Co., Ltd., trade name: Adecaria Sorb SR-10], simple. 125 parts of cyclohexyl methacrylate, 147.5 parts of 2-ethylhexyl acrylate, 200 parts of n-butyl acrylate, 10 parts of hydroxyethyl methacrylate and 4-methacryloyloxy-1,2,2,6,6-pentamethylpiperidin 15 as body components. 2.5 parts of triazine-based ultraviolet absorber [manufactured by BASF Japan Co., Ltd., trade name: TINUVIN400] so that the amount of triazine-based ultraviolet absorber is 0.5 parts per 100 parts of all monomer components. The pre-emulsion for dropping in the second stage and 15 parts of a 5% aqueous ammonium persulfate solution containing the above were uniformly dropped into the flask over 120 minutes.

After completion of the dropping, the contents of the flask were maintained at 80 ° C. for 60 minutes, the pH was adjusted to 8 by adding 25% aqueous ammonia, and the polymerization was completed. The obtained reaction solution was cooled to room temperature and then filtered through a 300 mesh wire mesh to prepare a resin emulsion. Table 1 shows the compositions of the monomer component and the ultraviolet absorber used as the resin raw material of the obtained resin emulsion.

Examples 3-5
A resin emulsion was prepared in the same manner as in Example 2 except that the monomer component and the triazine-based ultraviolet absorber were changed as shown in Table 1. Table 1 shows the compositions of the monomer component and the triazine-based ultraviolet absorber used as the resin raw material of the obtained resin emulsion.

Example 6
716 parts of deionized water was placed in a flask equipped with a dropping funnel, a stirrer, a nitrogen gas introduction tube, a thermometer and a reflux condenser. 139 parts of deionized water, 40 parts of 25% aqueous solution of emulsifier [manufactured by ADEKA Co., Ltd., trade name: Adecaria Soap SR-10], 185 parts of methyl methacrylate, 125 parts of cyclohexyl methacrylate as monomer components, 10 parts of hydroxyethyl methacrylate and 10 parts of 4-methacryloyloxy-1,2,2,6,6-pentamethylpiperidin, and 3.1 parts of triazine-based ultraviolet absorber per 100 parts of all monomer components. A pre-emulsion for first-stage dropping containing 10 parts of a triazine-based ultraviolet absorber [manufactured by BASF Japan Co., Ltd., trade name: TINUVIN400] was prepared so as to be a monomer component and a triazine-based ultraviolet absorber. 51 parts, which is 10% of the total amount of the above, was added into the flask, the temperature was raised to 80 ° C. while gently blowing nitrogen gas, and 10 parts of a 5% aqueous ammonium persulfate solution was added to initiate polymerization. Then, the rest of the pre-emulsion for dropping and 10 parts of a 5% ammonium persulfate aqueous solution were uniformly dropped into the flask over 90 minutes.

After completion of the dropping, the contents of the flask were maintained at 80 ° C. for 60 minutes, followed by 139 parts of deionized water and 40 parts of a 25% aqueous solution of an emulsifier [manufactured by ADEKA Corporation, trade name: ADEKA CORPORATION SR-10]. , 125 parts of cyclohexyl methacrylate, 175 parts of 2-ethylhexyl acrylate, 10 parts of 4-methacryloyloxy-1,2,2,6,6-pentamethylpiperidin and 10 parts of γ-methacryloyloxypropyltrimethoxysilane as monomer components. And 10 parts of the triazine-based ultraviolet absorber [manufactured by BASF Japan Co., Ltd., trade name: TINUVIN400] was contained so that the amount of the triazine-based ultraviolet absorber per 100 parts of all the monomer components was 3.1 parts. The pre-emulsion for dropping in the second stage and 10 parts of a 5% aqueous ammonium persulfate solution were uniformly dropped into the flask over 90 minutes.

After completion of the dropping, the contents of the flask were maintained at 80 ° C. for 60 minutes, followed by 139 parts of deionized water and 40 parts of a 25% aqueous solution of an emulsifier [manufactured by ADEKA Corporation, trade name: ADEKA CORPORATION SR-10]. , 125 parts of cyclohexyl methacrylate, 140 parts of n-butyl methacrylate, 35 parts of 2-ethylhexyl acrylate, 10 parts of 4-methacryloyloxy-1,2,2,6,6-pentamethylpiperidin and γ-methacryloyloxy as monomer components. Triazine-based UV absorber [manufactured by BASF Japan Co., Ltd., trade name: TINUVIN400] so that the amount of triazine-based UV absorber per 10 parts of propyltrimethoxysilane and 100 parts of all monomer components is 3.1 parts. ] 10 parts of the pre-emulsion for second-stage dropping and 10 parts of the 5% aqueous ammonium persulfate solution containing 10 parts were uniformly dropped into the flask over 90 minutes.

After completion of the dropping, the contents of the flask were maintained at 80 ° C. for 60 minutes, the pH was adjusted to 8 by adding 25% aqueous ammonia, and the polymerization was completed. The obtained reaction solution was cooled to room temperature and then filtered through a 300 mesh wire mesh to prepare a resin emulsion. Table 1 shows the compositions of the monomer component and the triazine-based ultraviolet absorber used as the resin raw material of the obtained resin emulsion.

Comparative Examples 1 to 4
A resin emulsion was prepared in the same manner as in Example 1 except that the monomer component and the ultraviolet absorber were changed as shown in Table 2. Table 2 shows the compositions of the monomer component and the ultraviolet absorber used as the resin raw material of the obtained resin emulsion.

The abbreviations shown in Tables 1 and 2 mean the following.
MMA: Methyl Methacrylate St: Styrene CHMA: Cyclohexyl Methacrylate 2 EHA: 2-Ethylhexyl Acrylate BA: n-Butyl Acrylate BMA: n-Butyl Methacrylate HEMA: 2-Hydroxyethyl Methacrylate Polymerizable HALS: 4-Methylloyloxy-1,2,2 , 6,6-Pentamethylpiperidin Non-polymerizable HALS: Bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and methyl 1,2,2,6,6-pentamethyl-4-piperidylseva Mixture with Kate [BASF Japan Co., Ltd., trade name: TINUVIN292]
TMSMA: γ-methacryloyloxypropyltrimethoxysilane TIN400: Triazine-based UV absorber [manufactured by BASF Japan Ltd., trade name: TINUVIN400]
TIN1130: Benzotriazole-based UV absorber [manufactured by BASF Japan Ltd., trade name: TINUVIN1130]

In addition, the terms described in Tables 1 and 2 below mean the following.
[Number of layers]
Number of resin layers constituting the emulsion particles contained in the resin emulsion [Amount of polymerizable HALS]
Content of polymerizable HALS in all monomer components (% by mass)
[Amount of triazine-based UV absorber]
Amount of triazine-based UV absorber per 100 parts of all monomer components (parts)
[Non-volatile content]
Non-volatile content (mass%) in resin emulsion
[Tg of layer 1]
Glass transition temperature (° C) of the resin layer 1 constituting the emulsion particles
[Tg of layer 2]
Glass transition temperature (° C) of the resin layer 2 constituting the emulsion particles
[Tg of layer 3]
Glass transition temperature (° C) of the resin layer 3 constituting the emulsion particles
[Total Tg]
Glass transition temperature (° C) of the emulsion particles themselves

In Table 1, it is shown that the layers 1 to 3 were polymerized in that order to form a layer. In the monomer component in Table 1, "-" means that the layer is not formed.

Experimental Examples Next, in 100 parts of the resin emulsion obtained in each Example or Comparative Example, 20 parts of water, 5 parts of butyl cellosolve [manufactured by Kyowa Hakko Bio Co., Ltd.] as a film forming aid, and 2,2,4- A mixed solution was obtained by adding 5 parts of trimethyl-1,3-pentanediol monoisobutyrate [manufactured by Chisso Co., Ltd., product number: CS-12]. The obtained mixed solution is added into a flask, ^{stirred with a homodisper at a rotation speed of 1500 min -1 for} 30 minutes, and measured at 25 ° C. using a Claves unit viscometer (manufactured by Brookfield, product number: KU-1). A thickener [manufactured by Nippon Catalyst Co., Ltd., trade name: Acryset WR-503A] was added into the flask so that the viscosity at the time of the reaction was 65 KU, and an antifoaming agent [manufactured by Sannopco Co., Ltd., trade name: SN Deformer 777] 0.3 part was added into the flask, and the mixture was stirred in that state for 30 minutes to prepare a sample for evaluation.

Using the evaluation paint obtained above, the physical characteristics of the resin emulsion, such as water resistance, ultraviolet transmission resistance, ultraviolet appearance retention, freeze-thaw repeated stability and transparency, were examined based on the following methods. The results are shown in Table 3.

(1) Water resistance The evaluation sample obtained above was made into a glass plate [manufactured by Nippon Test Panel Co., Ltd., length: 70 mm, width: 150 mm, thickness: 2 mm], and the thickness of the coating film after drying was 50 μm. It was applied with an applicator so as to be, and dried at a temperature of 80 ° C. for 2 hours.

Next, the 60 ° mirror surface gloss (hereinafter referred to as the gloss before immersion in warm water) on the surface coated with the evaluation sample was measured with a gloss meter [Nippon Denshoku Kogyo Co., Ltd., product number: VG2000], and further 50 ° C. After immersing it in warm water for one day, it is taken out of the water, and the gloss of the painted surface of the glass plate (hereinafter referred to as gloss after immersion in warm water) is measured with the gloss meter.
Formula: [Gloss retention rate (%)] = [[Gloss after immersion in warm water] ÷ [Gloss before immersion in warm water]] × 100
The water resistance was evaluated based on the following evaluation criteria.

〔Evaluation criteria〕
⊚: Gloss retention rate is 90% or more ○: Gloss retention rate is 75% or more and less than 90% Δ: Gloss retention rate is 60% or more and less than 75% ×: Gloss retention rate is less than 60%

(2) Air UV-resistant slate plate [manufactured by Nippon Test Panel Co., Ltd., length: 70 mm, width: 150 mm, thickness: 6 mm] with a sealer [manufactured by SK Kaken Co., Ltd., product name: EX sealer] A coating film was formed by uniformly applying a coating amount of 150 g / m ^{2 by} spraying and drying in the air at 23 ° C. for 1 week.

The following colored paint is applied onto the coating film formed above with an applicator so that the thickness of the coating film after drying is 100 μm, dried in the air at 23 ° C. for 1 week, and then further said. On the coating film formed on the surface of the slate plate, the evaluation sample obtained above was applied with an applicator so that the thickness of the coating film after drying was 20 μm, and in the air at 23 ° C. 1 A test plate was obtained by drying for a week.

[Colored paint]
Acrylic resin emulsion [manufactured by Nippon Catalyst Co., Ltd., trade name: Acryset EMN-210E], 10 parts of water, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate as a film-forming aid [Manufactured by Chisso Co., Ltd., product number: CS-12] Add 10 parts, ^{stir with a homodisper at a rotation speed of 1500 min -1 for} 30 minutes, and 30 parts of the white paste and antifoaming agent described below [Sannopco Co., Ltd. ), Product name: SN Deformer 777] 0.5 parts is added so that the viscosity when measured at 25 ° C. using a Claves unit viscosity meter (manufactured by Brookfield, product number: KU-1) becomes 70 KU. A thickener [ADEKA Co., Ltd., trade name: Adecanol UH-420] was added to the paste, followed by an aqueous color paste [SK Kaken Co., Ltd., trade name: SK aqueous color (mixed color of red rust, oak and blue). )] 5 parts were added, and the mixture was stirred in that state for 30 minutes to prepare a colored paint.

[White paste]
210 parts of deionized water, dispersant [manufactured by Kao Corporation, trade name: Demor EP] 60 parts, dispersant [manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: Discoat N-14] 50 parts, wetting agent [Made by Kao Corporation, trade name: Emargen LS-106] 10 parts, propylene glycol 60 parts, titanium oxide [Made by Ishihara Sangyo Co., Ltd., product number: CR-95] 1000 parts and glass beads (diameter: 1 mm) 200 A white paste was prepared by dispersing the parts with a homodisper ^{at a rotation speed of 3000 min -1 for 60 minutes.}

The side surface and the back surface of the test plate obtained above are sealed with aluminum tape, and the color difference (L ₀ , a ₀ , b ₀ ) of the coating film surface of the test plate is measured by a color difference meter [Nippon Denshoku Kogyo Co., Ltd., Product name: Spectral color difference meter SE-2000]. Next, after performing an ultraviolet irradiation test for 800 hours under the following ultraviolet irradiation test conditions, the color difference (L ₁ , a ₁ , b ₁ ) of the coating film surface of the test plate was measured, and the color tone change (ΔE) before and after the test was measured. ), Formula:
ΔE = [(L ₁ −L ₀ ) ² + (a ₁ −a ₀ ) ² + (b ₁ −b ₀ ) ² ] ^1/2
The UV resistance was evaluated based on the following evaluation criteria.

[Ultraviolet irradiation test conditions]
・ Testing machine: Metal weather meter [manufactured by Daipla Wintes Co., Ltd., product number: KU-R5 type]
-Irradiation: Irradiation for 4 hours in an atmosphere with a temperature of 65 ° C and a relative humidity of 50% (irradiation intensity: 65 mW / cm ² )
・ Wetness: Wet for 4 hours in an atmosphere with a temperature of 65 ° C and a relative humidity of 98% ・ Water shower: Shower for 30 seconds before and after wetting

〔Evaluation criteria〕
⊚: ΔE is less than 1 ○: ΔE is 1 or more and less than 3 Δ: ΔE is 3 or more and less than 5 ×: ΔE is 5 or more

(3) Ultraviolet appearance retention property The side surface and the back surface of the test plate obtained above are sealed with aluminum tape, and the 60 ° mirror surface gloss (hereinafter referred to as the gloss before the irradiation test) of the coating surface of the test plate is measured by a glossimeter. It was measured by [manufactured by Nippon Denshoku Kogyo Co., Ltd., product number: VG2000]. Next, after performing an ultraviolet irradiation test for 1000 hours under the same conditions as the ultraviolet irradiation test conditions, the 60 ° mirror surface gloss (hereinafter referred to as gloss after the irradiation test) of the coating surface of the test plate is measured with the gloss meter. Measure and measure the change in gloss (appearance maintenance rate%) before and after the test, using the formula:
[Appearance maintenance rate (%)] = [[Gloss after irradiation test] ÷ [Gloss before irradiation test]] × 100
The UV appearance retention was evaluated based on the following evaluation criteria.

〔Evaluation criteria〕
⊚: Appearance maintenance rate is 90% or more ○: Appearance maintenance rate is 75% or more and less than 90% Δ: Appearance maintenance rate is 60% or more and less than 75% ×: Appearance maintenance rate is less than 60%

(4) Repeated freeze-thaw stability After sealing the side surface of the test plate obtained above with a silicone-based bath bond [manufactured by Konishi Co., Ltd.], cool it to -20 ° C in the air using a freeze-thaw tester. After freezing for 2 hours, the operation of immersing in water at 20 ° C. for 1 hour is defined as one cycle, and every 100 cycles, a loupe with a magnification of 30 times is used to observe the state of cracks on the coating surface of the test plate. However, the above operation was performed for 300 cycles, and the freeze-thaw repeated stability was evaluated based on the following evaluation criteria.

〔Evaluation criteria〕
⊚: No problem in 300 cycles ○: No problem in 200 cycles, crack occurs in 300 cycles Δ: No problem in 100 cycles, crack occurs in 200 cycles ×: Crack occurs in 100 cycles

(5) Transparency In accordance with JIS K7105, the difference in transparency (haze) between the polyester film and the coating film is measured using a turbidity meter [manufactured by Nippon Denshoku Kogyo Co., Ltd., product number: NDH300A], and the coating film is coated. The transparency of the film was evaluated based on the following evaluation criteria.

〔Evaluation criteria〕
⊚: Haze difference is less than 0.5% 〇: Haze difference is 0.5% or more and less than 1% Δ: Haze difference is 1% or more and less than 2% ×: Haze difference is 2% or more

(6) Comprehensive evaluation Next, in each physical property, the overall score (maximum score: 100 points) is given with 20 points for ◎, 15 points for 〇, 10 points for △, and 0 points for ×. The results were tabulated and the results are shown in the comprehensive evaluation column of Table 3. If there is even one x in the evaluation, it is rejected.

From the results shown in Table 3, it can be seen that the resin emulsions obtained in each of the examples form a coating film having excellent ultraviolet transmission resistance and ultraviolet appearance retention. Further, it can be seen that the resin emulsions obtained in each of the examples form a coating film excellent in water resistance, freeze-thaw repeated stability and transparency. Therefore, all of the resin emulsions obtained in each example can form a coating film having comprehensively excellent UV transparency, UV appearance retention, water resistance, freeze-thaw repeated stability and transparency. Recognize.

The resin emulsion of the present invention can be suitably used for surface finishing of a base material made of a material such as metal, glass, porcelain, concrete, siding board, or resin. Therefore, the resin emulsion of the present invention is referred to as, for example, a top coat applied to the surface of ceramic building materials, automobiles, buildings, civil engineering structures, etc., especially the exterior of buildings, ceramic building materials, etc. It can be suitably used for the topcoat paint.

Claims (5)

A resin emulsion containing emulsion particles containing a triazine-based ultraviolet absorber, which is polymerizable with a monomer component used as a raw material for a resin layer constituting the emulsion particles contained in the resin emulsion. A cycloalkyl (meth) acrylate having a weight and a cycloalkyl group having 3 to 12 carbon atoms is used , and a triazine-based ultraviolet absorber is contained in the monomer component, and per 100 parts by mass of the monomer component. The amount of the triazine-based ultraviolet absorber is 0.1 to 5 parts by mass, and the triazine-based ultraviolet absorber is 2- [4-[(2-hydroxy-3-dodecyloxypropyl) oxy] -2-hydroxy. Phenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- [4-[(2-hydroxy-3-tridecyloxypropyl) oxy] -2-hydroxyphenyl ] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- [4-[(2-hydroxy-3- (2'-ethyl) hexyl) oxy] -2- Hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2,4-bis (2-hydroxy-4-butyloxyphenyl) -6- (2,4-) Bis-butyloxyphenyl) -1,3,5-triazine, hydroxyphenyltriazine, 2- (2-hydroxy-4- [1-octyloxycarbonylethoxy] phenyl) -4,6-bis (4-phenylphenyl) At least one selected from the group consisting of -1,3,5-triazine and 2,4,6-tris (2-hydroxy-4-hexyloxy-3-methylphenyl) -1,3,5-triazine. resin emulsion according to claim der Rukoto triazine-based UV absorber. Resin emulsion according to claim 1, wherein the content ratio of the cycloalkyl (meth) acrylate is 10 to 80 wt% having a cycloalkyl group having 3 to 12 carbon atoms in the previous SL monomer component. Top coat, characterized by containing a resin emulsion according to請Motomeko 1 or 2. A method for producing a resin emulsion containing a triazine-based ultraviolet absorber, which is a polymerizable hindered amine-based photostable as the monomer component when a monomer component is polymerized in the presence of the triazine-based ultraviolet absorber. A monomer component containing a sex monomer and a cycloalkyl (meth) acrylate having a cycloalkyl group having 3 to 12 carbon atoms is used , and 2- [4-[(2-hydroxy-3) is used as the monomer component. -Dodecyloxypropyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- [4-[(2-hydroxy-3-tri) Decyloxypropyl) Oxy] -2-Hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- [4-[(2-Hydroxy-3- (2) '-Ethyl) hexyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2,4-bis (2-hydroxy-4-butyl) Oxyphenyl) -6- (2,4-bis-butyloxyphenyl) -1,3,5-triazine, hydroxyphenyltriazine, 2- (2-hydroxy-4- [1-octyloxycarbonylethoxy] phenyl)- 4,6-bis (4-phenylphenyl) -1,3,5-triazine and 2,4,6-tris (2-hydroxy-4-hexyloxy-3-methylphenyl) -1,3,5-triazine selected from the group consisting of a is at least one triazine-based UV absorber, it adjusts the amount of the monomer component per 100 parts by weight of the triazine-based UV absorber 0.1 to 5 parts by weight A method for producing a resin emulsion . Method for producing a resin emulsion according to claim 4 before Symbol content cycloalkyl (meth) acrylate having a cycloalkyl group having 3 to 12 carbon atoms in the monomer component is 10 to 80 mass%.