JP2009235139A - Alkali-proof binder resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a binder resin composition very excellent in water resistance, alkali resistance and chemical resistance and also having good storage stability. <P>SOLUTION: The alkali-proof binder resin composition includes a crosslinked emulsion obtained by emulsion-polymerizing a monomer including 0.1-5 wt.% of at least one monomer selected from epoxy group-containing ethylenically unsaturated monomers, alkoxysilyl group-containing ethylenically unsaturated monomers and N-methylol group-containing ethylenically unsaturated monomers, and 0.2-5 wt.% of at least one monomer selected from carboxyl group-containing ethylenically unsaturated monomers and t-butyl group-containing ethylenically unsaturated monomers in 100 wt.% of an ethylenically unsaturated monomer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an alkali-resistant binder resin composition, and more particularly to an alkali-resistant binder resin composition excellent in chemical resistance, water resistance, and alkali resistance of a coating film obtained.

  Conventionally, the binder resin composition has been used in various fields, and the application range thereof has been steadily expanding, and accordingly, the required performance for the binder resin composition is becoming increasingly sophisticated. In recent years, there has been a binder resin composition that is excellent in performance balance such as adhesion, chemical resistance, moisture resistance, weather resistance, (warm) water resistance, alkali resistance, and contamination recovery, and can form a coating film with high hardness. It has been demanded. As a binder resin composition that satisfies some of these requirements, a composition comprising a partial condensate of organosilane, a colloidal silica dispersion and a silicone-modified acrylic resin (Patent Document 1), or a condensate of organosilane, zirconium A composition comprising a chelate compound of alkoxide and a hydrolyzable silyl group-containing vinyl resin (Patent Document 2) has been proposed. However, these binder resin compositions are all solvent-based, and from the viewpoint of low pollution, resource saving, safety and hygiene in recent years, there is a strong demand for solvent removal, and they are shifting to water systems.

  However, the water-based binder resin composition has a problem that water resistance, alkali resistance, chemical resistance and the like are inferior to those of the solvent type among various physical properties. Under such circumstances, development of a reactive resin emulsion has been intensively studied as one that can be expected to improve performance such as water resistance, alkali resistance, and chemical resistance, and one of them is a resin emulsion having a hydrolyzable silyl group. Has been proposed. For example, Patent Document 3 discloses a reactive resin emulsion containing a vinyl polymer having a hydrolyzable silyl group and an amineimide group, and Patent Document 4 discloses a vinyl polymer having an alkoxysilyl group. An aqueous coating composition comprising a combined aqueous dispersion and a tin compound aqueous dispersion is disclosed.

However, these hydrolyzable silyl group-containing resin emulsions are inferior in storage stability, and particularly when this emulsion is stored for a long period of time, it becomes gelled or the performance of the coating film obtained from the emulsion after long-term storage is Unlike a coating film obtained from an emulsion immediately after production, there is a drawback that stable quality cannot be ensured, and there is a problem in practicality. Or, even when the storage stability is relatively good, it is not satisfactory in terms of the performance balance that combines adhesion, chemical resistance, moisture resistance, weather resistance, (warm) water resistance, contamination recovery, etc. there were.
JP-A-60-135465 JP-A 64-1769 Japanese Patent Laid-Open No. 7-26035 Japanese Patent Laid-Open No. 7-91510

  The present invention has been made against the background of the above-mentioned problems of the prior art, and an object thereof is to provide a binder resin composition that is extremely excellent in water resistance, alkali resistance, chemical resistance, and also has good storage stability. And

  The first invention of the present invention is an epoxy group-containing ethylenically unsaturated monomer, an alkoxysilyl group-containing ethylenically unsaturated monomer, and an N-methylol group in 100% by weight of the ethylenically unsaturated monomer. 0.1 to 5% by weight of at least one monomer selected from containing ethylenically unsaturated monomers, carboxyl group containing ethylenically unsaturated monomers, and tertiary butyl group containing ethylenically unsaturated monomers The present invention relates to an alkali-resistant binder resin composition comprising a crosslinked emulsion obtained by emulsion polymerization of a monomer containing at least one monomer selected from 0.2 to 5% by weight.

  Further, the second invention relates to at least one unit selected from a carboxyl group-containing unsaturated monomer and a tertiary butyl group-containing ethylenically unsaturated monomer in 100% by weight of the ethylenically unsaturated monomer. An alkali-resistant binder comprising: a cross-linked emulsion obtained by emulsion polymerization of a monomer containing 0.5 to 10% by weight of a monomer; and a compound having at least two functional groups capable of reacting with a carboxyl group. The present invention relates to a resin composition.

  A third invention relates to a crosslinked emulsion obtained by emulsion polymerization of a monomer containing 0.5 to 10% by weight of a carbonyl group-containing unsaturated monomer in 100% by weight of an ethylenically unsaturated monomer. And an alkali-resistant binder resin composition comprising a compound having at least two functional groups capable of reacting with a carbonyl group.

  The fourth invention further includes at least one monomer selected from styrene, 2-ethylhexyl acrylate, and cyclohexyl methacrylate in the ethylenically unsaturated monomer. The present invention relates to an alkali-resistant binder resin composition of any invention.

  According to the present invention, it was possible to provide a binder resin composition having extremely excellent water resistance, alkali resistance, chemical resistance, and excellent storage stability.

  The alkali-resistant binder resin composition of the present invention includes a cross-linked emulsion obtained by emulsion polymerization of a monomer containing an ethylenically unsaturated monomer having a specific functional group. When the cross-linked emulsion has a cross-linked structure with a specific functional group, a binder resin composition excellent in resistance to high concentrations of alkali, water resistance, adhesion to a substrate, and flexibility can be obtained. The cross-linked structure of the cross-linked emulsion in the present invention may be cross-linking inside the particles or cross-linking by particles, and may be cross-linked by adding a cross-linking agent separately.

  First, the case where the cross-linked structure of the cross-linked emulsion is cross-linking inside the particles will be described. In this case, the crosslinked emulsion used for the alkali-resistant binder resin composition of the present invention is composed of 100% by weight of ethylenically unsaturated monomer, epoxy group-containing ethylenically unsaturated monomer, alkoxysilyl group-containing ethylenic monomer. 0.1 to 5% by weight of at least one monomer selected from an unsaturated monomer and an N-methylol group-containing ethylenically unsaturated monomer, a carboxyl group-containing ethylenically unsaturated monomer, and tarsha It can be obtained by emulsion polymerization of an ethylenically unsaturated monomer containing 0.2 to 5% by weight of at least one monomer selected from a butyl group-containing ethylenically unsaturated monomer.

  0.1 weight of at least one monomer selected from an epoxy group-containing ethylenically unsaturated monomer, an alkoxysilyl group-containing ethylenically unsaturated monomer, and an N-methylol group-containing ethylenically unsaturated monomer If it is less than%, the emulsion will not be sufficiently crosslinked, resulting in poor resistance to high concentrations of alkali and water resistance. On the other hand, if it exceeds 5% by weight, there will be a problem in the polymerization stability at the time of emulsion polymerization, or even if it can be polymerized, there will be a problem in the storage stability.

  Further, when at least one monomer selected from a carboxyl group-containing ethylenically unsaturated monomer and a tertiary butyl group-containing ethylenically unsaturated monomer is less than 0.2% by weight, a high concentration of alkali The resistance to water and water resistance deteriorate, and the stability of the emulsion also deteriorates. On the other hand, if it exceeds 5% by weight, the hydrophilicity after drying becomes too strong, and the resistance to high concentrations of alkali and the water resistance deteriorate.

  The epoxy group in the epoxy group-containing ethylenically unsaturated monomer can react with the carboxyl group in the carboxyl group-containing ethylenically unsaturated monomer during polymerization and drying to introduce a crosslinked structure into the emulsion particles. At this time, the tertiary butyl group in the tertiary butyl group-containing ethylenically unsaturated monomer also forms a tertiary butyl alcohol and a carboxyl group when heat above a certain temperature is applied. Can react with. Examples of the epoxy group-containing ethylenically unsaturated monomer include glycidyl (meth) acrylate and 3,4-epoxycyclohexyl (meth) acrylate.

  The alkoxysilyl groups in the alkoxysilyl group-containing ethylenically unsaturated monomer can react with each other mainly during polymerization to introduce a crosslinked structure into the emulsion particles. Examples of the alkoxysilyl group-containing ethylenically unsaturated monomer include γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-methacryloxypropyltributoxysilane, and γ-methacryloxypropylmethyldimethoxy. Silane, γ-methacryloxypropylmethyldiethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-acryloxypropyltriethoxysilane, γ-acryloxypropylmethyldimethoxysilane, γ-methacryloxymethyltrimethoxysilane, γ- Examples include acryloxymethyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltributoxysilane, and vinylmethyldimethoxysilane.

  The N-methylol groups in the N-methylol group-containing ethylenically unsaturated monomer can react with each other mainly during polymerization to introduce a crosslinked structure into the marble particles. Examples of the N-methylol group-containing ethylenically unsaturated monomer include N-methylol acrylamide and N-methylol methacrylamide.

  Examples of the carboxyl group-containing ethylenically unsaturated monomer include maleic acid, fumaric acid, itaconic acid, citraconic acid, or alkyl or alkenyl monoesters thereof, phthalic acid β- (meth) acryloxyethyl monoester, isophthalic acid Acid β- (meth) acryloxyethyl monoester, terephthalic acid β- (meth) acryloxyethyl monoester, succinic acid β- (meth) acryloxyethyl monoester, acrylic acid, methacrylic acid, crotonic acid, cinnamic acid Etc. Moreover, tertiary butyl (meth) acrylate etc. are mentioned as a tertiary butyl group containing ethylenically unsaturated monomer.

  Next, a case where the cross-linked structure of the cross-linked emulsion is cross-linking between particles will be described. In this case, the crosslinked emulsion used in the alkali-resistant binder resin composition of the present invention is composed of 100% by weight of the ethylenically unsaturated monomer, the carboxyl group-containing unsaturated monomer, and the tertiary butyl group-containing ethylenic monomer. It can be obtained by emulsion polymerization of an ethylenically unsaturated monomer containing 0.5 to 10% by weight of at least one monomer selected from unsaturated monomers. Further, in this case, a compound having at least two functional groups capable of reacting with a carboxyl group is added to the obtained emulsion as a crosslinking agent, and a crosslinked structure can be introduced when dried using as a binder.

  When at least one monomer selected from a carboxyl group-containing ethylenically unsaturated monomer and a tertiary butyl group-containing ethylenically unsaturated monomer is less than 0.5% by weight, crosslinking of the emulsion is sufficient. As a result, resistance to a high concentration of alkali and water resistance deteriorate, and the stability of the emulsion also deteriorates. On the other hand, if it exceeds 10% by weight, the hydrophilicity after drying becomes too strong, the resistance to high concentrations of alkali and the water resistance are deteriorated, and the stability after the addition of the crosslinking agent is deteriorated. Examples of the carboxyl group-containing ethylenically unsaturated monomer and the tertiary butyl group-containing ethylenically unsaturated monomer include the same monomers as described above.

  Examples of the compound having at least two functional groups capable of reacting with a carboxyl group used as a crosslinking agent include polyfunctional epoxy compounds, polyfunctional amine compounds, polyfunctional aziridine compounds, polyfunctional carbodiimide compounds, polyfunctional oxazoline compounds, and Examples include metal chelate compounds.

  Examples of the polyfunctional epoxy compound include bisphenol A-epichlorohydrin type epoxy resin, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6-hexanediol. Diglycidyl ether, trimethylolpropane triglycidyl ether, diglycidyl aniline, N, N, N ′, N′-tetraglycidyl-m-xylylenediamine, 1,3-bis (N, N′-diglycidylaminomethyl) And cyclohexane.

  Examples of the polyfunctional aziridine compound include N, N′-diphenylmethane-4,4′-bis (1-aziridinecarboxite), N, N′-toluene-2,4-bis (1-aziridinecarboxite), Bisisophthaloyl-1- (2-methylaziridine), tri-1-aziridinylphosphine oxide, N, N′-hexamethylene-1,6-bis (1-aziridinecarboxite), trimethylolpropane-tri -Β-aziridinylpropionate, tetramethylolmethane-tri-β-aziridinylpropionate, tris-2,4,6- (1-aziridinyl) -1,3,5-triazine, trimethylolpropane Tris [3- (1-aziridinyl) propionate], trimethylolpropane tris [3- (1-aziridinyl) buty Rate], trimethylolpropane tris [3- (1- (2-methyl) aziridinyl) propionate], trimethylolpropane tris [3- (1-aziridinyl) -2-methylpropionate], 2,2′-bis Hydroxymethylbutanol tris [3- (1-aziridinyl) propionate], pentaerythritol tetra [3- (1-aziridinyl) propionate], diphenylmethane-4,4-bis-N, N′-ethyleneurea, 1,6-hexa And methylenebis-N, N′-ethyleneurea, 2,4,6- (triethyleneimino) -Syn-triazine, bis [1- (2-ethyl) aziridinyl] benzene-1,3-carboxylic acid amide, and the like. It is done.

  As the polyfunctional carbodiimide compound, for example, a compound having two or more carbodiimide groups (—N═C═N—) in the molecule is preferably used, and a known polycarbodiimide can be used.

  Moreover, as a polyfunctional carbodiimide compound, the high molecular weight polycarbodiimide produced | generated by carrying out the decarboxylation condensation reaction of diisocyanate in presence of a carbodiimidization catalyst can also be used. Examples of such compounds include those obtained by subjecting the following diisocyanates to a decarboxylation condensation reaction.

  As the diisocyanate, 4,4′-diphenylmethane diisocyanate, 3,3′-dimethoxy-4,4′-diphenylmethane diisocyanate, 3,3′-dimethyl-4,4′-diphenylmethane diisocyanate, 4,4′-diphenyl ether diisocyanate, 3,3′-dimethyl-4,4′-diphenyl ether diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1-methoxyphenyl-2,4-diisocyanate, isophorone diisocyanate, 4,4′- One of dicyclohexylmethane diisocyanate, tetramethylxylylene diisocyanate, or a mixture thereof can be used.

  As the carbodiimidization catalyst, 1-phenyl-2-phospholene-1-oxide, 3-methyl-2-phospholene-1-oxide, 1-ethyl-3-methyl-2-phospholene-1-oxide, 1-ethyl- Phosphorene oxides such as 2-phospholene-1-oxide or their 3-phospholene isomers can be used.

  Examples of such polyfunctional carbodiimide compounds include the Carbodilite series manufactured by Nisshinbo Industries, Ltd. Among these, Carbodilite V-01, 03, 05, 07, and 09 are preferable because of excellent compatibility with organic solvents.

  As the polyfunctional oxazoline compound, a compound having two or more oxazoline groups in the molecule is preferably used. Specifically, 2′-methylenebis (2-oxazoline), 2,2′-ethylenebis (2-oxazoline) is used. 2,2′-ethylenebis (4-methyl-2-oxazoline), 2,2′-propylenebis (2-oxazoline), 2,2′-tetramethylenebis (2-oxazoline), 2,2′- Hexamethylene bis (2-oxazoline), 2,2′-octamethylene bis (2-oxazoline), 2,2′-p-phenylene bis (2-oxazoline), 2,2′-p-phenylene bis (4 4'-dimethyl-2-oxazoline), 2,2'-p-phenylenebis (4-methyl-2-oxazoline), 2,2'-p-phenylenebis (4-phenyl) Lu-2-oxazoline), 2,2'-m-phenylenebis (2-oxazoline), 2,2'-m-phenylenebis (4-methyl-2-oxazoline), 2,2'-m-phenylenebis (4,4′-dimethyl-2-oxazoline), 2,2′-m-phenylenebis (4-phenylenebis-2-oxazoline), 2,2′-o-phenylenebis (2-oxazoline), 2, 2'-o-phenylenebis (4-methyl-2-oxazoline), 2,2'-bis (2-oxazoline), 2,2'-bis (4-methyl-2-oxazoline), 2,2'- Bis (4-ethyl-2-oxazoline), 2,2′-bis (4-phenyl-2-oxazoline) and the like can be mentioned. Alternatively, vinyl monomers such as 2-isopropenyl-2-oxazoline and 2-isopropenyl-4,4-dimethyl-2-oxazoline and other monomers that can be copolymerized with these vinyl monomers. It may be a copolymer with a monomer.

  Examples of the metal chelate compound include compounds in which a polyvalent metal such as aluminum, iron, copper, zinc, tin, titanium, titanium, nickel, antimony, magnesium, vanadium, chromium, and zirconium is coordinated to acetylacetone or ethyl acetoacetate. Can be mentioned.

  These compounds are preferably added in an amount of 0.1 to 10 parts by weight, more preferably 1 to 5 parts by weight, based on 100 parts by weight of the solid content of the crosslinked emulsion.

  Furthermore, in the present invention, the cross-linked emulsion used in the alkali-resistant binder resin composition is a single emulsion containing 0.5 to 10% by weight of carbonyl group-containing unsaturated monomer in 100% by weight of ethylenically unsaturated monomer. The polymer can be obtained by emulsion polymerization. Furthermore, also in this case, a compound having at least two functional groups capable of reacting with a carbonyl group is added as a crosslinking agent to the obtained emulsion, and a crosslinked structure is introduced when dried using as a binder.

  When the carbonyl group-containing ethylenically unsaturated monomer is less than 0.5% by weight, the emulsion is not sufficiently crosslinked, resulting in poor resistance to high concentrations of alkali and water resistance. On the other hand, if it exceeds 10% by weight, the stability after the addition of the crosslinking agent is deteriorated. Examples of the carbonyl group-containing ethylenically unsaturated monomer include diacetone acrylamide, diacetone methacrylamide, acrolein, N-vinylformamide, vinyl methyl ketone, vinyl ethyl ketone, acetoacetoxyethyl acrylate, acetoacetoxypropyl acrylate, and acetoacetate. Examples include acetoxybutyl acrylate, acetoacetoxyethyl methacrylate, acetoacetoxypropyl methacrylate, and acetoacetoxybutyl methacrylate.

  Examples of the compound having at least two functional groups capable of reacting with a carbonyl group used as a crosslinking agent include hydrazine derivatives having at least two hydrazide groups in one molecule, such as oxalic acid dihydrazide, malonic acid dihydrazide, and succinic acid. In addition to aliphatic dihydrazides such as acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, and sebacic acid dihydrazide, carbonic polyhydrazide, aliphatic, alicyclic, aromatic bissemicarbazide, aromatic dicarboxylic acid dihydrazide, polyhydrazide of polyacrylic acid And dihydrazides of unsaturated dicarboxylic acids such as dihydrazides of aromatic hydrocarbons, hydrazine-pyridine derivatives and maleic acid dihydrazides. These compounds are preferably added in an amount of 0.1 to 10 parts by weight, more preferably 1 to 5 parts by weight, based on 100 parts by weight of the solid content of the emulsion.

Examples of the monomer other than the ethylenically unsaturated monomer that can be used when polymerizing the crosslinked emulsion of the present invention include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) ) Acrylate, n-butyl (meth) acrylate, pentyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, heptyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (Meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate Alkyl (meth) acrylates such as rate, octadecyl (meth) acrylate, nonadecyl (meth) acrylate, icosyl (meth) acrylate, henecosyl (meth) acrylate, docosyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate ;
2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, glycerol mono (meth) acrylate, 4-hydroxyvinylbenzene, 1-ethynyl-1-cyclohexanol, allyl Hydroxyl-containing ethylenically unsaturated compounds such as alcohol;
Diethylamino group-containing ethylenically unsaturated compounds such as dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, methylethylaminoethyl (meth) acrylate, dimethylaminostyrene, diethylaminostyrene;
(Meth) acrylamide, N-methoxymethyl- (meth) acrylamide, N-ethoxymethyl- (meth) acrylamide, N-propoxymethyl- (meth) acrylamide, N-butoxymethyl- (meth) acrylamide, N-pentoxymethyl -(Meth) acrylamide, N, N-di (methylol) acrylamide, N-methylol-N-methoxymethyl (meth) acrylamide, N, N-di (methoxymethyl) acrylamide, N-ethoxymethyl-N-methoxymethylmeta Acrylamide, N, N-di (ethoxymethyl) acrylamide, N-ethoxymethyl-N-propoxymethyl methacrylamide, N, N-di (propoxymethyl) acrylamide, N-butoxymethyl-N- (propoxymethyl) methacrylamide, N, -Di (butoxymethyl) acrylamide, N-butoxymethyl-N- (methoxymethyl) methacrylamide, N, N-di (pentoxymethyl) acrylamide, N-methoxymethyl-N- (pentoxymethyl) methacrylamide, etc. A substituted or unsubstituted amide group-containing ethylenically unsaturated compound;
Perfluoromethylmethyl (meth) acrylate, perfluoroethylmethyl (meth) acrylate, 2-perfluorobutylethyl (meth) acrylate, 2-perfluorohexylethyl (meth) acrylate, 2-perfluorooctylethyl (meth) acrylate , 2-perfluoroisononylethyl (meth) acrylate, 2-perfluorononylethyl (meth) acrylate, 2-perfluorodecylethyl (meth) acrylate, perfluoropropylpropyl (meth) acrylate, perfluorooctylpropyl (meta ) Perfluoroalkyl having a C 1-20 perfluoroalkyl group such as acrylate, perfluorooctyl amyl (meth) acrylate, perfluorooctyl undecyl (meth) acrylate, etc. (Meth) acrylate;
Perfluoroalkyl group-containing ethylenically unsaturated compounds such as perfluoroalkylalkylenes such as perfluorobutylethylene, perfluorohexylethylene, perfluorooctylethylene, perfluorodecylethylene;
Polyethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, ethoxypolyethylene glycol (meth) acrylate, propoxypolyethylene glycol (meth) acrylate, n-butoxypolyethylene glycol (meth) acrylate, n-pentoxypolyethylene glycol (meth) Acrylate, phenoxypolyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, methoxypolypropylene glycol (meth) acrylate, ethoxypolypropylene glycol (meth) acrylate, propoxypolypropylene glycol (meth) acrylate, n-butoxypolypropylene glycol (meth) acrylate N-Pentoxypolypropylene Recall (meth) acrylate, phenoxypolypropylene glycol (meth) acrylate, polytetramethylene glycol (meth) acrylate, methoxypolytetramethylene glycol (meth) acrylate, phenoxytetraethylene glycol (meth) acrylate, hexaethylene glycol (meth) acrylate, Ethylenically unsaturated compounds having a polyether chain such as methoxyhexaethylene glycol (meth) acrylate;
Ethylenically unsaturated compounds having a polyester chain such as lactone-modified (meth) acrylate;
(Meth) acrylic acid dimethylaminoethyl methyl chloride salt, trimethyl-3- (1- (meth) acrylamide-1,1-dimethylpropyl) ammonium chloride, trimethyl-3- (1- (meth) acrylamidopropyl) ammonium chloride, And quaternary ammonium base-containing ethylenically unsaturated compounds such as trimethyl-3- (1- (meth) acrylamide-1,1-dimethylethyl) ammonium chloride;
Fatty acid vinyl compounds such as vinyl acetate, vinyl butyrate, vinyl propionate, vinyl hexanoate, vinyl caprylate, vinyl laurate, vinyl palmitate, vinyl stearate;
Vinyl ether compounds such as butyl vinyl ether and ethyl vinyl ether;
Α-olefin compounds such as 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene;
Allyl compounds such as allyl acetate, allylbenzene, allyl cyanide;
Vinyl compounds such as vinyl cyanide, vinylcyclohexane, vinylmethylketone, styrene, α-methylstyrene, 2-methylstyrene, chlorostyrene;
Examples include ethynyl compounds such as acetylene, ethynylbenzene, and ethynyltoluene.

  Among these monomers, it is possible to use at least one monomer selected from styrene, 2-ethylhexyl acrylate, and cyclohexyl methacrylate, resistance to high concentrations of alkali and water resistance, adhesion to a substrate, and flexibility. It is preferable because of its excellent properties. When using styrene, it is preferable that the usage-amount is 5 to 60 weight% in 100 weight% of ethylenically unsaturated monomers. Moreover, when using 2-ethylhexyl acrylate, it is preferable that the usage-amount is 20 to 60 weight% in 100 weight% of ethylenically unsaturated monomers. Moreover, when using cyclohexyl methacrylate, it is preferable that the usage-amount is 5 to 50 weight% in 100 weight% of ethylenically unsaturated monomers.

  The crosslinked emulsion of the present invention is synthesized by a conventionally known emulsion polymerization method.

  As the emulsifier used in the emulsion polymerization in the present invention, a conventionally known one such as a reactive emulsifier having an ethylenically unsaturated group and / or a non-reactive emulsifier having no ethylenically unsaturated group is arbitrarily used. can do.

  Reactive emulsifiers having an ethylenically unsaturated group can be further roughly classified into anionic and nonionic nonionic ones. In particular, when an anionic reactive emulsifier or a nonionic reactive emulsifier having an ethylenically unsaturated group is used, the dispersion particle diameter of the copolymer becomes fine and the particle size distribution becomes narrow, so that alkali resistance and water resistance are improved. This is preferable because it can be performed. This anionic reactive emulsifier or nonionic reactive emulsifier having an ethylenically unsaturated group may be used singly or in combination.

Specific examples of the anionic reactive emulsifier having an ethylenically unsaturated group are illustrated below, but the emulsifiers that can be used in the present invention are not limited to those described below. Examples of the emulsifier include alkyl ethers (commercially available products include, for example, Aqualon KH-05, KH-10, KH-20, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Adeka Soap SR-10N, SR-20N manufactured by ADEKA Corporation. Latemuru PD-104 manufactured by Kao Corporation);
Sulfosuccinic acid ester-based (for example, Latmul S-120, S-120A, S-180P, S-180A, Sanyo Chemical Co., Ltd., Elemiol JS-2, etc., manufactured by Kao Corporation);
Alkyl phenyl ether type or alkyl phenyl ester type (commercially available products include, for example, Aqualon H-2855A, H-3855B, H-3855C, H-3856, HS-05, HS-10, HS, manufactured by Daiichi Kogyo Seiyaku Co., Ltd. -20, HS-30, ADEKA Corporation ADEKA rear soap SDX-222, SDX-223, SDX-232, SDX-233, SDX-259, SE-10N, SE-20N, SE-, etc.);
(Meth) acrylate sulfate ester (commercially available products such as Antox MS-60, MS-2N, Sanyo Kasei Kogyo Co., Ltd. Elminol RS-30 manufactured by Nippon Emulsifier Co., Ltd.);
Examples of the phosphoric acid ester (commercially available products include H-3330PL manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Adeka Soap PP-70 manufactured by ADEKA Co., Ltd.) and the like.

Nonionic reactive emulsifiers that can be used in the present invention include, for example, alkyl ether-based (commercially available products such as Adeka Soap ER-10, ER-20, ER-30, ER-40, manufactured by ADEKA Corporation, Latemu PD-420, PD-430, PD-450, etc. manufactured by Kao Corporation);
Alkyl phenyl ether type or alkyl phenyl ester type (commercially available products include, for example, Aqualon RN-10, RN-20, RN-30, RN-50, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., ADEKA rear soap NE- manufactured by ADEKA Co., Ltd. 10, NE-20, NE-30, NE-40, etc.);
(Meth) acrylate sulfate-based (as commercial products, for example, RMA-564, RMA-568, RMA-1114, etc. manufactured by Nippon Emulsifier Co., Ltd.) can be mentioned.

  In obtaining the cross-linked emulsion of the present invention by emulsion polymerization, a non-reactive emulsifier having no ethylenically unsaturated group can be used in combination with the above-described reactive emulsifier having an ethylenically unsaturated group, if necessary. Non-reactive emulsifiers can be broadly classified into non-reactive anionic emulsifiers and non-reactive nonionic emulsifiers.

Examples of non-reactive nonionic emulsifiers include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether and polyoxyethylene stearyl ether;
Polyoxyethylene alkylphenyl ethers such as polyoxyethylene octylphenyl ether and polyoxyethylene nonylphenyl ether;
Sorbitan higher fatty acid esters such as sorbitan monolaurate, sorbitan monostearate, sorbitan trioleate;
Polyoxyethylene sorbitan higher fatty acid esters such as polyoxyethylene sorbitan monolaurate;
Polyoxyethylene higher fatty acid esters such as polyoxyethylene monolaurate and polyoxyethylene monostearate;
Glycerin higher fatty acid esters such as oleic acid monoglyceride and stearic acid monoglyceride;
Examples thereof include polyoxyethylene / polyoxypropylene / block copolymer and polyoxyethylene distyrenated phenyl ether.

Examples of non-reactive anionic emulsifiers include higher fatty acid salts such as sodium oleate;
Alkylaryl sulfonates such as sodium dodecylbenzenesulfonate;
Alkyl sulfate salts such as sodium lauryl sulfate;
Polyoxyethylene alkyl ether sulfate ester salts such as sodium polyoxyethylene lauryl ether sulfate;
Polyoxyethylene alkylaryl ether sulfate salts such as sodium polyoxyethylene nonylphenyl ether sulfate;
Alkyl sulfosuccinic acid ester salts such as sodium monooctyl sulfosuccinate, sodium dioctyl sulfosuccinate, sodium polyoxyethylene lauryl sulfosuccinate and derivatives thereof;
Examples thereof include polyoxyethylene distyrenated phenyl ether sulfate salts.

  The usage-amount of the emulsifier used in this invention is not necessarily limited, According to the physical property calculated | required when a crosslinked emulsion is finally used as an alkali-resistant binder resin composition, it can select suitably. For example, the amount of the emulsifier is usually preferably 0.1 to 30 parts by weight, more preferably 0.3 to 20 parts by weight, based on 100 parts by weight of the total of ethylenically unsaturated monomers. More preferably, it is in the range of 5 to 10 parts by weight.

In the emulsion polymerization of the crosslinked emulsion of the present invention, a water-soluble protective colloid can be used in combination. Examples of the water-soluble protective colloid include polyvinyl alcohols such as partially saponified polyvinyl alcohol, fully saponified polyvinyl alcohol, and modified polyvinyl alcohol;
Cellulose derivatives such as hydroxyethylcellulose, hydroxypropylcellulose, carboxymethylcellulose salts;
Natural polysaccharides such as guar gum; and the like, and these can be used singly or in combination. The amount of the water-soluble protective colloid used is 0.1 to 5 parts by weight, more preferably 0.5 to 2 parts by weight, based on 100 parts by weight of the total amount of ethylenically unsaturated monomers.

  Examples of the aqueous medium used in the emulsion polymerization of the cross-linked emulsion of the present invention include water, and a hydrophilic organic solvent can be used as long as the object of the present invention is not impaired.

  The polymerization initiator used for obtaining the crosslinked emulsion of the present invention is not particularly limited as long as it has the ability to initiate radical polymerization, and a known oil-soluble polymerization initiator or water-soluble polymerization initiator is used. be able to. The oil-soluble polymerization initiator is not particularly limited, and examples thereof include benzoyl peroxide, tert-butyl peroxybenzoate, tert-butyl hydroperoxide, tert-butyl peroxy (2-ethylhexanoate), and tert-butyl peroxide. Organic peroxides such as oxy-3,5,5-trimethylhexanoate, di-tert-butyl peroxide, 2,2′-azobisisobutyronitrile, 2,2′-azobis-2,4- Examples thereof include azobis compounds such as dimethylvaleronitrile, 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 1,1′-azobiscyclohexane-1-carbonitrile and the like. These can be used alone or in combination of two or more. These polymerization initiators are preferably used in an amount of 0.1 to 10.0 parts by weight with respect to 100 parts by weight of the ethylenically unsaturated monomer.

  In the present invention, it is preferable to use a water-soluble polymerization initiator. For example, ammonium persulfate, potassium persulfate, hydrogen peroxide, 2,2′-azobis (2-methylpropionamidine) dihydrochloride and the like are conventionally known. A thing can be used conveniently. Moreover, when performing emulsion polymerization, a reducing agent can be used together with a polymerization initiator if desired. Thereby, it becomes easy to accelerate the emulsion polymerization rate or to perform the emulsion polymerization at a low temperature. Examples of such a reducing agent include reducing organic compounds such as metal salts such as ascorbic acid, ersorbic acid, tartaric acid, citric acid, glucose, formaldehyde sulfoxylate, sodium thiosulfate, sodium sulfite, sodium bisulfite, Examples include reducing inorganic compounds such as sodium bisulfite, ferrous chloride, Rongalite, thiourea dioxide, and the like. These reducing agents are preferably used in an amount of 0.05 to 5.0 parts by weight with respect to 100 parts by weight of the total ethylenically unsaturated monomer. In addition, it can superpose | polymerize by a photochemical reaction, radiation irradiation, etc. irrespective of an above described polymerization initiator. The polymerization temperature is not less than the polymerization start temperature of each polymerization initiator. For example, in the case of a peroxide-based polymerization initiator, it may be usually about 70 ° C. The polymerization time is not particularly limited, but is usually 2 to 24 hours.

  Further, if necessary, sodium acetate, sodium citrate, sodium bicarbonate, etc. as a buffering agent, and octyl mercaptan, 2-ethylhexyl thioglycolate, stearyl mercaptan, lauryl mercaptan, t-dodecyl mercaptan as chain transfer agents A suitable amount of mercaptans such as can be used.

When a monomer having an acidic functional group such as a carboxyl group-containing ethylenically unsaturated monomer is used for the polymerization of the cross-linked emulsion, it can be neutralized with a basic compound before or after the polymerization. When neutralizing, ammonia or alkylamines such as trimethylamine, triethylamine, butylamine;
Alcohol amines such as 2-dimethylaminoethanol, diethanolamine, triethanolamine, aminomethylpropanol;
It can be neutralized with a base such as morpholine. However, it is a highly volatile base that has a high effect on drying properties, and preferred bases are aminomethylpropanol and ammonia.

  The glass transition temperature (hereinafter also referred to as Tg) of the resin of the cross-linked emulsion is preferably −5 to 70 ° C., more preferably 10 ° C. to 50 ° C. When Tg is less than −5 ° C., tackiness tends to occur in the coating film, and resistance to high concentrations of alkali and water resistance often deteriorate. On the other hand, when Tg exceeds 70 ° C., the flexibility of the coating film becomes poor and the moldability of the coating film may be inferior. The glass transition temperature is a value obtained using a DSC (differential scanning calorimeter).

  In the present invention, the particle structure of the cross-linked emulsion may be a multilayer structure, so-called core-shell particles. For example, it is possible to localize a resin obtained by mainly polymerizing a monomer having a functional group in the core part or the shell part, or to provide a difference in Tg or composition between the core and the shell, thereby providing curability and drying properties. The film forming property can be improved.

  The average particle size of the dispersed particles of the crosslinked emulsion is preferably 10 to 500 nm, more preferably 30 to 200 nm, from the viewpoint of emulsion stability. Further, when a large amount of coarse particles exceeding 1 μm are contained, the stability of the emulsion is impaired, so that the coarse particles exceeding 1 μm are preferably at most 5% by weight. In addition, the average particle diameter in the present invention represents a volume average particle diameter and can be measured by a dynamic light scattering method.

  The crosslinking type emulsion of the present invention may contain a film forming aid, an antifoaming agent, a leveling agent, a preservative, a pH adjusting agent, a viscosity adjusting agent, and the like as required.

  The film-forming aid is responsible for the temporary plasticization function that helps the formation of the coating film and evaporates relatively quickly after the coating film is formed, thereby improving the strength of the coating film. Is preferably an organic solvent having a temperature of 110 to 200 ° C. Specifically, propylene glycol monobutyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol monobutyl ether, diethylene glycol diethyl ether, dipropylene glycol monopropyl ether, carbitol, butyl carbitol, dibutyl carbitol, benzyl alcohol, etc. Is mentioned. Among these, ethylene glycol monobutyl ether and propylene glycol monobutyl ether are particularly preferable because they have a high film forming auxiliary effect in a small amount. These film forming aids are preferably contained in an amount of 1 to 30 parts by weight based on 100 parts by weight of the solid content of the cross-linked emulsion.

  The viscosity modifier may be used in an amount of 1 to 100 parts by weight with respect to 100 parts by weight of the crosslinked emulsion. Examples of the viscosity modifier include carboxymethylcellulose, methylcellulose, hydroxymethylcellulose, ethylcellulose, polyvinyl alcohol, polyacrylic acid (and its salt), oxidized starch, phosphorylated starch, and casein.

  The alkali-resistant binder resin composition of the present invention is a surface coating of an alkaline substrate such as a ceramic building material such as concrete, mortar, slate board, ALC board (lightweight cellular concrete panel), siding board, etc. used in buildings and structures. Can be used for water-based architectural paints, metal surface treatment agents, capacitors, alkaline battery separators, electrode binders, solar cells, and the like.

  The present invention will be described more specifically with reference to the following examples. However, the following examples do not limit the scope of rights of the present invention. In the examples, “part” represents “part by weight” and “%” represents “% by weight”.

Example 1
A reaction vessel equipped with a stirrer, a thermometer, a dropping funnel and a reflux condenser was charged with 40 parts of ion-exchanged water and 0.2 part of Adeka Soap SR-10 (manufactured by ADEKA) as a surfactant. 10 parts of styrene, 60 parts of 2-ethylhexyl acrylate, 10 parts of methyl methacrylate, 10 parts of cyclohexyl methacrylate, 5 parts of acrylic acid, 1 part of acrylamide, 4 parts of glycidyl methacrylate, 53 parts of ion-exchanged water, and ADEKA rear soap SR- 1% of a pre-emulsion in which 1.8 parts of 10 (manufactured by ADEKA Co., Ltd.) was mixed in advance was further added. After raising the internal temperature to 70 ° C. and sufficiently substituting with nitrogen, 10% of 10 parts of a 5% aqueous solution of potassium persulfate was added to initiate polymerization. After maintaining the reaction system at 70 ° C. for 5 minutes, the remaining pre-emulsion and the remaining 5% aqueous solution of potassium persulfate were added dropwise over 3 hours while maintaining the internal temperature at 70 ° C., and stirring was further continued for 2 hours. . After confirming that the conversion rate exceeded 98% by solid content measurement, the temperature was cooled to 30 ° C. 25% aqueous ammonia was added to adjust the pH to 8.5, and the solid content was adjusted to 48% with ion-exchanged water to obtain a crosslinked emulsion. In addition, solid content was calculated | required by 150 degreeC 20 minute baking residue.
[Examples 2 to 4 and Comparative Examples 1 to 2]
The composition shown in Table 1 was synthesized in the same manner as in Example 1 to obtain the crosslinked emulsions of Examples 2 to 4 and the non-crosslinked emulsions of Comparative Examples 1 and 2.

[Examples 5 to 7]
In the composition shown in Table 1, after ethylenically unsaturated monomers were polymerized by the same method as in Example 1 to synthesize an emulsion, the crosslinking agent shown in Table 1 was added and Examples 5-7 were used. A crosslinked emulsion was obtained. In addition, 10% of the surfactant to be used was charged into a reaction vessel, and the remaining 90% was used for preparation of a pre-emulsion.

Carbodilite V-02; Carbodiimide curing agent (Nisshinbo Co., Ltd., NCN equivalent 600)
ADEKA rear soap SR-10; alkyl ether anionic surfactant (manufactured by ADEKA Corporation)
ADEKA rear soap ER-20; alkyl ether nonionic surfactant (manufactured by ADEKA Corporation)

[Creation of coating film]
2 parts by weight of ethylene glycol monobutyl ether was added to 100 parts by weight of the solid content in the obtained emulsion, and an appropriate amount of ion-exchanged water was added so that the solid content was 40% to obtain a binder resin composition. . The obtained resin composition was applied to a glass substrate and dried at 80 ° C. for 10 minutes to obtain a transparent coating film. About the binder resin composition obtained by the Example and the comparative example, the coating film was created by said method, and water resistance, alkali resistance, and the storage stability of the emulsion were evaluated.

(water resistant)
The produced coating film was immersed in ion-exchanged water at 40 ° C. for 12 hours, and judged by the weight change rate of the coating film before and after immersion. The evaluation criteria are shown below. The evaluation results are shown in Table 2.
○: “Weight change less than 5%”
○: “Weight change 5% or more and less than 10%”
Δ ×: “Weight change 10% or more and less than 20%”
×: “Weight change 20% or more”

(Alkali resistance)
The prepared coating film was immersed in a 6N aqueous potassium hydroxide solution at 40 ° C. for 12 hours, and judged by the weight change rate of the coating film before and after immersion. The evaluation criteria are shown below. The evaluation results are shown in Table 2.
○: “Weight change less than 5%”
○: “Weight change 5% or more and less than 10%”
Δ ×: “Weight change 10% or more and less than 20%”
×: “Weight change 20% or more”

(Storage stability evaluation)
The binder resin compositions obtained in Examples 1 to 7 and Comparative Examples 1 and 2 were stored at 40 ° C. for 1 week, and evaluated by the rate of change in viscosity before and after storage. If the viscosity change rate after storage for 1 week is within ± 10% with reference to the viscosity before storage, it was rated as ○, and if it was ± 10% or more, it was marked as ×. The evaluation results are shown in Table 2.

  As shown in Table 2, the binder resin compositions using the crosslinkable emulsions of Examples 1 to 7 are balanced in water resistance, resistance to high-concentration alkali, and storage stability. On the other hand, some binder resin compositions using the non-crosslinkable emulsions of Comparative Examples 1 and 2 have good emulsion stability, but both have poor water resistance and resistance to high concentrations of alkali.

Claims (4)

  From 100% by weight of ethylenically unsaturated monomer, from epoxy group-containing ethylenically unsaturated monomer, alkoxysilyl group-containing ethylenically unsaturated monomer, and N-methylol group-containing ethylenically unsaturated monomer At least one monomer selected from 0.1 to 5% by weight, and at least one monomer selected from a carboxyl group-containing ethylenically unsaturated monomer and a tertiary butyl group-containing ethylenically unsaturated monomer An alkali-resistant binder resin composition comprising a crosslinked emulsion obtained by emulsion polymerization of a monomer containing 0.2 to 5% by weight.   0.5 to 10 weight percent of at least one monomer selected from a carboxyl group-containing unsaturated monomer and a tertiary butyl group-containing ethylenically unsaturated monomer in 100 weight percent of ethylenically unsaturated monomer An alkali-resistant binder resin composition comprising a cross-linked emulsion obtained by emulsion polymerization of a monomer containing 1% and a compound having at least two functional groups capable of reacting with a carboxyl group.   A crosslinked emulsion obtained by emulsion polymerization of a monomer containing 0.5 to 10% by weight of a carbonyl group-containing unsaturated monomer in 100% by weight of an ethylenically unsaturated monomer, and a functional group capable of reacting with the carbonyl group An alkali-resistant binder resin composition comprising a compound having at least two groups.   The alkali-resistant binder according to any one of claims 1 to 3, further comprising at least one monomer selected from styrene, 2-ethylhexyl acrylate, and cyclohexyl methacrylate in the ethylenically unsaturated monomer. Resin composition.