JP2005220241A - Aqueous curable composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aqueous curable composition which excels in the external appearance of the obtained coating film such as smoothness, brilliancy, and transparency, the physical strength such as hardness, impact resistance, flex resistance, and scratch resistance, excels in the chemical properties such as solvent resistance and acid rain resistance, the weatherability and the like, is easy to manufacture, and can be suitably used as a water dispersion slurry coating material or an aqeuous coating material. <P>SOLUTION: The aqueous curable composition comprises a water soluble and/or water dispersible polymer (a) having an average of two or more epoxy groups in the molecule, (b) a curable agent (b), an organic solvent (c), and water (d), and the curing agent (c) comprises an aliphatic tricarboxylic acid. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a curable composition comprising at least an epoxy group-containing polymer, a water-soluble aliphatic tricarboxylic acid, an organic solvent, and water. More specifically, it comprises a water-soluble and / or water-dispersible polymer having an average of two or more epoxy groups in the molecule, a water-soluble aliphatic tricarboxylic acid, an organic solvent, and water that can be suitably used for water-based paints. The present invention relates to a curable composition, particularly to a curable composition used for an aqueous clear topcoat paint for automobiles.

Conventionally, curable compositions comprising an epoxy group-containing compound and a carboxyl group-containing compound have been used for various coatings. There are various combinations of these. For example, in the case of powder paints and water-dispersed slurry paints, glycidyl group-containing acrylics are used because they have excellent appearance, weather resistance, stain resistance, etc. A combination of resin and dibasic acid is preferred.
The powder coating is usually produced by melting and kneading a resin, a curing agent, an additive, and the like at a temperature not higher than the melting point of the curing agent and then pulverizing. Powder paints and water-dispersed slurry paints in which powders are dispersed in water together with dispersants, etc. contain little organic solvent, and are thus increasingly expected as environmentally friendly paints. Already used in building materials, automotive parts, water supplies, steel furniture, etc., it is also beginning to be used in some top coats of automobiles.

However, powder coatings require replacement of the coating equipment when replaced with solvent-based coatings, and there are many problems to be solved, such as dust and bump problems in the recycling of coatings. On the other hand, in the water-dispersed slurry paint described in Patent Document 1, although the solvent-based paint coating equipment can be diverted, the powder paint produced by melt-kneading and pulverizing is further dispersed in water together with a dispersant, etc. The coating film obtained was long and was not satisfactory in appearance such as smoothness, sharpness and transparency. In addition, the water-dispersed slurry paint described in Patent Document 2 is manufactured by emulsifying and dispersing a melt-kneaded melt in an aqueous medium, cooling and filtering, and the process can be shortened. It was not satisfactory.
JP-T-2001-517722 Special table 2003-522824 gazette

  The present invention uses a small amount of organic solvent in the paint, and the physical properties such as the appearance, hardness, impact resistance, flex resistance, scratch resistance, etc. of the resulting coating film are smooth, sharp, transparent, etc. To provide a water-based curable composition that is excellent in chemical properties such as strength, solvent resistance, acid rain resistance, and weather resistance, is easy to manufacture, and can be suitably used as a water-dispersed slurry paint or water-based paint. Objective.

As a result of intensive studies to solve the above problems, the present inventors have found that a water-soluble and / or water-dispersible polymer having an average of two or more epoxy groups in the molecule, a water-soluble aliphatic tricarboxylic acid In addition, the present inventors have found that a combination of specific organic solvents can meet the purpose and completed the present invention based on this finding.
That is, the first of the present invention is a water-soluble and / or water-dispersible polymer (a) having an average of two or more epoxy groups in the molecule, a curing agent (b), an organic solvent (c) and water ( An aqueous curable composition comprising at least d), wherein the curing agent (b) contains an aliphatic tricarboxylic acid.
The second aspect of the present invention is that the mass of the organic solvent (c) is 0.1 to 40 parts by mass when the sum of the mass of the polymer (a) and the curing agent (b) is 100 parts by mass. This is the first water-based curable composition of the present invention.
A third aspect of the present invention is characterized in that the curing agent (b) is composed of 0.1 to 100% by mass of the aliphatic tricarboxylic acid represented by the following formula (1) and 0 to 99.9% by mass of the other curing agent. The water-based curable composition according to the first or second aspect of the present invention.

[Wherein p, r, and s are integers of 0 to 8, q is an integer of 1 to 9, and 1 ≦ p + q + r + s ≦ 9 and {r <s or (r = s and p ≦ q)}]

A fourth aspect of the present invention is the third aqueous curable composition according to the present invention, wherein p + q + r + s = 3 in the above formula (1).
A fifth aspect of the present invention is the aqueous curable composition according to the third or fourth aspect of the present invention, wherein p = 1, q = 2, and r = s = 0.
According to a sixth aspect of the present invention, the organic solvent (c) comprises one or more selected from compounds having at least one ketone group, hydroxyl group, ether group or ester group, and the proportion of the compound in the organic solvent Is an aqueous curable composition according to any one of the first to fifth aspects of the present invention.
A seventh aspect of the present invention is the water-based curable composition according to any one of the first to sixth aspects of the present invention, wherein the organic solvent (c) contains propylene glycol monomethyl ether.

An eighth aspect of the present invention is the aqueous curable composition according to any one of the first to seventh aspects of the present invention, wherein the polymer (a) is an epoxy group-containing acrylic resin polymer.
A ninth aspect of the present invention is an aqueous paint for automobiles comprising the aqueous hardener composition according to any one of the first to eighth aspects of the present invention.
According to a tenth aspect of the present invention, there is provided an aqueous paint for clear topcoat comprising the aqueous curing agent composition according to any one of the first to eighth aspects of the present invention.
An eleventh aspect of the present invention is a coating film formed from the water-based paint according to the ninth or tenth aspect of the present invention.

  The curable composition of the present invention has an appearance such as smoothness, sharpness and transparency of the resulting coating film, physical strength such as hardness, impact resistance, flex resistance, and scratch resistance, solvent resistance, It is excellent in chemical properties such as acid rain resistance, weather resistance, etc., is easy to produce, and can be suitably used as a water-dispersed slurry paint or water-based paint.

The present invention is described in detail below.
The curable composition of the present invention comprises a water-soluble and / or water-dispersible polymer (a) having an average of two or more epoxy groups in the molecule, a water-soluble aliphatic tricarboxylic acid, an organic solvent (c) and water. Consists of.
First, the polymer (a) used in the present invention will be described.
The polymer (a) used in the present invention is a water-soluble polymer having a terminal, side chain or branched chain having an epoxy group such as a glycidyl group, a water-dispersible polymer, a water-soluble polymer and a water-dispersible polymer. Including a mixture with a polymer, directly produced by polymerizing a polymerizable monomer in an aqueous medium, and / or a powder resin dissolved in an aqueous medium composed of a mixture of water, alcohol, etc. and / or Commonly used ones such as those emulsified and dispersed can be mentioned.

  These polymers include, for example, a polymer having a polyester skeleton, a polymer having a polyamide skeleton, a poly (meth) acrylate, a polyvinyl acetate, a vinyl acetate-acrylic, a vinyl acetate-mixed trialkyl vinyl acetate, Ethylene vinyl acetate, silicone, polybutadiene, styrene butadiene, NBR, polyvinyl chloride, chlorinated polypropylene, polyethylene, polystyrene, vinylidene chloride, polystyrene- (meth) acrylate, styrene-anhydrous malee Examples include polymers such as acid-based polymers, including silicone-modified acrylic, fluorine-acrylic, acrylic silicon-based, epoxy-acrylic modified polymers, crosslinkable resins, core / shell type resins, etc. One or more of these can be used. Among them, epoxy group-containing acrylic resins such as poly (meth) acrylate, vinyl acetate-acrylic, polystyrene- (meth) acrylate, silicone-modified acrylic, fluorine-acrylic, acrylic silicon, epoxy-acrylic, etc. A coalescence can be used conveniently. (Meth) acrylate expressed in the present invention means acrylate or methacrylate.

  The epoxy group referred to in the present invention is a bonding group having an epoxy structure (a three-membered ring structure composed of carbon-oxygen-carbon), and the carbon-carbon part may be a part of a linear or branched hydrocarbon structure. It may be a part of a hydrocarbon structure in which a cyclic structure such as a 5-membered ring or a 6-membered ring is formed. In addition, halogens such as fluorine, chlorine and bromine, and functional groups such as hydroxyl groups and nitrile groups may be bonded to these hydrocarbon structures. Furthermore, an alkyl group such as a methyl group, a halogen, or the like may be bonded to the carbon atom forming the epoxy structure. Examples of these epoxy groups include glycidyl groups and bonding groups represented by the following formula (2). In particular, a glycidyl group is desirable because it is industrially produced from allyl alcohol and epichlorohydrin and is easily available.

(In the formula, R ¹ and R ² represent a hydrocarbon group having 1 to 12 carbon atoms, and m represents an integer of 0 to 3).
The polymer (a) is a polymer of one or more polymerizable monomers having an epoxy group, or one or more polymerizable monomers having an epoxy group and a polymerizable monomer having no epoxy group. The above copolymer. As the polymerizable monomer having an epoxy group, for example, a compound having a glycidyl group or a methylglycidyl group represented by the following formula (3) can be particularly preferably used.

  Examples of the polymerizable monomer having an epoxy group include glycidyl (meth) acrylate, β-methylglycidyl (meth) acrylate, 2,3-epoxycyclohexyl (meth) acrylate, and 3,4-epoxycyclohexyl (meth). Examples thereof include (meth) acrylic acid esters such as acrylate, glycidyl ether and methyl glycidyl ether of allyl alcohol, N-glycidyl acrylic acid amide, and vinyl sulfonic acid glycidyl. One or more of these monomers can be used. Among them, glycidyl methacrylate is easily available industrially, and a glycidyl group-containing (meth) acrylic resin, which is a copolymer using the glycidyl methacrylate, is excellent in durability such as weather resistance and abrasion resistance of the obtained cured product. The curable composition of the present invention is particularly preferable when used for coatings.

The polymerizable monomer having an epoxy group is preferably used in the range of 5 to 70% by mass of the total polymerizable monomer.
Examples of the polymerizable monomer having no epoxy group that can be copolymerized with the above polymerizable monomer having an epoxy group include (meth) acrylic acid esters, (meth) acrylamide monomers, and vinyl cyanides. Can be mentioned. Examples of (meth) acrylic acid esters include (meth) acrylic acid alkyl esters having 1 to 18 carbon atoms in the alkyl group, (meth) acrylic acid hydroxyalkyl esters having 1 to 18 carbon atoms in the hydroxyalkyl group, and ethylene. (Poly) oxyethylene (meth) acrylate having 1 to 100 oxide groups, (poly) oxypropylene (meth) acrylate having 1 to 100 propylene oxide groups, and 1 to 100 ethylene oxide groups (Poly) oxyethylene di (meth) acrylate and the like. Specific examples of the (meth) acrylic acid alkyl ester include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, and n- (meth) acrylate. Butyl, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, ( Octyl (meth) acrylate, 2-ethyloctyl (meth) acrylate, benzyl (meth) acrylate, dodecyl (meth) acrylate, phenyl (meth) acrylate, stearyl (meth) acrylate, isobornyl (meth) acrylate Etc.

Specific examples of (meth) acrylic acid hydroxyalkyl esters include (meth)
Examples include 2-hydroxyethyl acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxycyclohexyl (meth) acrylate, and hydroxydodecyl (meth) acrylate.
Specific examples of (poly) oxyethylene (meth) acrylate include ethylene glycol (meth) acrylate, ethylene glycol methoxy (meth) acrylate, diethylene glycol (meth) acrylate, diethylene glycol methoxy (meth) acrylate, (meth) Examples include tetraethylene glycol acrylate and tetraethylene glycol methoxy (meth) acrylate. Specific examples of (poly) oxypropylene (meth) acrylate include propylene glycol (meth) acrylate, propylene glycol methoxy (meth) acrylate, dipropylene glycol (meth) acrylate, dipropylene glycol methoxy (meth) acrylate , (Meth) acrylic acid tetrapropylene glycol, methoxy (meth) acrylic acid tetrapropylene glycol, and the like.

Specific examples of (poly) oxyethylene di (meth) acrylate include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetra (di (meth) acrylate) Examples include ethylene glycol.
Examples of (meth) acrylamide monomers include (meth) acrylamide,
N-methylol (meth) acrylamide, N-butoxymethyl (meth) acrylamide, and the like, and examples of vinyl cyanides include (meth) acrylonitrile.

Moreover, you may use an ethylenically unsaturated carboxylic acid monomer as a polymerizable monomer which does not have an epoxy group. Examples thereof include acrylic acid, methacrylic acid, itaconic acid, fumaric acid, maleic acid, maleic anhydride, and itaconic acid, fumaric acid, maleic acid half esters.
Further, an ethylenically unsaturated monomer having a cationic group may be used. Examples thereof include dimethylaminoethyl (meth) acrylate and salts thereof, diethylaminoethyl (meth) acrylate and salts thereof, dimethylaminopropyl (meth) acrylate and salts thereof, dimethylaminomethyl (meth) acrylamide and salts thereof, Dimethylaminoethyl (meth) acrylamide and its salt, dimethylaminopropyl (meth) acrylamide and its salt, vinylpyridine, halide of dimethylaminomethyl (meth) acrylamide epichlorohydrin adduct, dimethylaminopropyl (meth) acrylamide epichlorohydrin adduct Halides and their alkyl sulfonates, halides of dimethylaminomethyl epichlorohydrin adduct (meth) acrylate, dimethylaminopropyl epichloro (meth) acrylate Halides and alkyl sulfonic acid salts of hydrin adducts.

  Specific examples of polymerizable monomers having no epoxy group other than those described above include, for example, olefins such as ethylene, propylene and isobutylene, dienes such as butadiene, haloolefins such as vinyl chloride and vinylidene chloride, vinyl acetate, Carboxylic acid vinyl esters such as vinyl propionate, vinyl n-butyrate, vinyl benzoate, vinyl pt-butyl benzoate, vinyl pivalate, vinyl 2-ethylhexanoate, mixed trialkyl vinyl acetate, vinyl laurate, Carboxylic acid isopropenyl esters such as isopropenyl acetate and isopropenyl propionate, vinyl ethers such as ethyl vinyl ether, isobutyl vinyl ether and cyclohexyl vinyl ether, aromatic vinyl compounds such as styrene, α-methyl styrene and vinyl toluene, fumar Esters such as acid dialkyl esters and itaconic acid dialkyl esters, allyl esters such as allyl acetate and allyl benzoate, allyl ethers such as allyl ethyl ether and allyl phenyl ether, and γ- (meth) acryloxypropyltrimethoxysilane , Vinylmethyldiethoxysilane, vinylmethyldimethoxysilane, vinyldimethylethoxysilane, vinyldimethylmethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 4- (meth) acryloyloxy-2,2,6,6-tetramethyl Piperidine, 4- (meth) acryloyloxy-1,2,2,6,6-pentamethylpiperidine, perfluoromethyl (meth) acrylate, perfluoropropyl (meth) acrylate, perfluoropropylmethyl (Meth) acrylate, vinylpyrrolidone, trimethylolpropane tri (meth) acrylate, allyl (meth) acrylate, acid phosphooxyethyl methacrylate, 3-chloro-2-acid phosphooxypropyl methacrylate, methylpropanesulfonic acid acrylamide, divinyl Examples thereof include benzene, vinyl oxazoline, lauryl vinyl ether, halogen-containing vinyl monomers, silicon-containing vinyl monomers, isocyanate group-containing vinyl monomers, and polyester resins having a copolymerizable unsaturated bond. One or more of these monomers can be used.

  In the present invention, a copolymer based on methyl methacrylate and glycidyl methacrylate, a copolymer based on methyl methacrylate, glycidyl methacrylate, and styrene, and further, methyl methacrylate and glycidyl methacrylate. , A glycidyl group-containing acrylic resin polymer such as a copolymer mainly composed of butyl (meth) acrylate and styrene, has excellent durability such as weather resistance and abrasion resistance, and is particularly suitable for the paint field. It can be particularly preferably used in the field.

  In the production of the curable composition of the present invention, when the polymer (a) is produced directly by polymerizing a polymerizable monomer in an aqueous medium, it is usually a polymerizable monomer having an epoxy group, an epoxy group. It can be obtained by suspension polymerization, microsuspension polymerization, emulsion polymerization, microemulsion polymerization, miniemulsion polymerization, or the like using a polymerizable monomer having no water, a water-soluble initiator and / or an oil-soluble initiator. At this time, a water-soluble reducing agent and / or an oil-soluble reducing agent may be used. In order to increase the reaction rate, it is preferable to pre-emulsify the monomer mixture into an aqueous medium in the presence of an emulsifier with an emulsifier such as a homogenizer in the polymerization.

  Moreover, it can superpose | polymerize by the same composition from beginning to end, it is also possible to superpose | polymerize by changing a composition continuously, and it is also possible to superpose | polymerize by dividing | segmenting into several steps with a different composition. When the polymer (a) is directly produced by polymerizing a polymerizable monomer in an aqueous medium and the polymer (a) is a mixture of a water-soluble polymer and a water-dispersible polymer, the A water-soluble polymer and a water-dispersible polymer polymerized in the same manner may be mixed, or the water-dispersible polymer may be polymerized in the same reactor following the polymerization of the water-soluble polymer. Following the polymerization of the water-soluble polymer, the water-soluble polymer may be polymerized in the same reactor.

When the polymer (a) is directly produced by polymerizing a polymerizable monomer in an aqueous medium, the polymer (a) may be any of anionic, cationic, nonionic, and amphoteric. However, cationicity is preferable.
When the polymer (a) is cationic, the above-mentioned ethylenically unsaturated monomer having a cationic group is mixed into the monomer mixture used for polymerization. The ethylenically unsaturated monomer having a cationic group is preferably used in an amount of 0.5% by mass to 30% by mass in the monomer mixture from the viewpoint of stability of the obtained polymer (a) in water. More preferably, the monomer mixture is used in an amount of 1% by mass to 20% by mass. When the content is 1% by mass or more, the permeability of the curable composition to the base substrate is further improved.

When the polymer (a) is directly produced by polymerizing a polymerizable monomer in an aqueous medium, the number average molecular weight of the polymer (a) is preferably from 1,000 to 1,000,000, and the viscosity and mechanical properties of the resulting film. From this point of view, it is more preferably 1000 to 500,000, and particularly preferably 2000 to 500,000.
When the polymer (a) is directly produced by polymerizing a polymerizable monomer in an aqueous medium, the epoxy equivalent of the polymer (a) is preferably in the range of 200 to 3,000 g / equivalent, 200 to The range of 2,000 g / equivalent is more preferable, and the range of 250 to 1,000 g / equivalent is particularly preferable. When the epoxy equivalent is larger than 200 g / equivalent, the finished appearance of the coating film is excellent, and when it is smaller than 3,000 g / equivalent, the coating film performance is excellent.

  Furthermore, when the polymer (a) is directly produced by polymerizing a polymerizable monomer in an aqueous medium, the Tg (glass transition temperature) of the polymer (a) is preferably 30 to 100 ° C. 40-90 degreeC is still more preferable, and 40-80 degreeC is especially preferable. When the glass transition temperature is 30 ° C. or higher, it becomes easy to handle the polymer, and when the glass transition temperature is lower than 100 ° C., the melt flowability of the polymer is excellent, and the finished appearance of the coating film is preferable.

  When the polymer (a) is produced directly by polymerizing a polymerizable monomer in an aqueous medium, water-soluble initiators used in the present invention include water-soluble persulfates, peroxides, and azobis compounds. Etc. can be used. Examples include potassium persulfate, sodium persulfate, ammonium persulfate, hydrogen peroxide, cumene hydroperoxide, t-butylperoxymaleic acid, 2,2′-azobis (2-amidinopropane) dihydrochloride, 2,2 '-Azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride, 2 , 2′-azobis {2-methyl-N- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] propionamide}, 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) ) Propionamide], 2,2′-azobis (2-methylpropionamide) dihydrate, and the like. The usage-amount is 0.1-10 mass parts normally with respect to 100 mass parts of total amounts of a monomer.

  When the polymer (a) is directly produced by polymerizing a polymerizable monomer in an aqueous medium, the oil-soluble initiator used in the present invention is radically decomposed by heat or a reducing substance as a radical polymerization catalyst. To cause addition polymerization of ethylenically unsaturated monomers, specifically 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis (2-methylbutyronitrile) ), 2,2′-azobisisobutyronitrile, 2,2-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2 , 2′-azobis [2- (2-imidazolin-2-yl) propane], 2,2′-azobis (2,4,4-trimethylpentane), 2-cyano-2-propyrazoformamide, di Such as til 2,2′-azobis (2-methylpropionate), 2,2′-azobis (2-hydroxymethylpropionitrile), 1,1′-azobis (1-acetoxy-1-phenylethane), etc. Examples thereof include azo initiators and peroxide initiators such as t-butyl hydroperoxide and cumene hydroperoxide. More preferably, methyl ethyl ketone peroxide, cyclohexanone peroxide, 3,5,5-trimethylcyclohexanone peroxide, methylcyclohexanone peroxide, acetylacetone peroxide, methyl acetoacetate peroxide, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, n-butyl 4,4-bis (t-butylperoxy) valerate, 2,2-bis (t-butyl) Peroxy) butane, 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis (t-butyl) Peroxy) cyclododecane, diisopropyl Pyrbenzene hydroperoxide, p-menthane hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, t-hexyl hydroperoxide, diisopropylbenzene bishydroperoxide, di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, α, α′-bis (t-butylperoxyisopropyl) benzene, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane, 2, 5-dimethyl-2,5-di (t-butylperoxy) hexyne-3, isobutyl peroxide, laurolyl peroxide, 3,5,5-trimethylhexanoyl peroxide, succinic acid peroxide, benzoyl peroxide, 2,4-dichlorobenzo Luperoxide, octanoyl peroxide, stearoyl peroxide, n-toluoyl peroxide, diisopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di-2-ethoxy Ethyl peroxydicarbonate, di-3-methoxybutyl peroxydicarbonate, di (3-methyl-3-methoxybutyl) peroxydicarbonate, bis (4-t-butylcyclohexyl) peroxydicarbonate, (a, a-bisneodecanoylperoxy) diisopropylbenzene, cumylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, t-hexylperoxyneodecanoate, t- Butyl -Oxyneodecanoate, t-hexylperoxypivalate, t-butylperoxypivalate, 2,5-dimethyl-2,5-bis (2-ethylhexanoylperoxy) hexane, 1,1,3 , 3-tetramethylbutylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate 1,1,3,3-tetramethylbutylperoxyisopropyl monocarbonate, t-butylperoxylaurate, t-butylperoxy-3,5,5-trimethylhexanoate, t-hexylperoxyisopropylmono Carbonate, t-butylperoxyisopropyl carbonate, 2,5-dimethyl-2,5-bi Peroxide initiators such as bis (benzoylperoxy) hexane, t-butylperoxyacetate, t-hexylperoxybenzoate, t-butylperoxybenzoate, and bis (t-butylperoxy) isophthalate are preferred. Moreover, these 2 types or more can also be used in combination. The usage-amount is 0-10 mass parts normally with respect to 100 mass parts of total amounts of a monomer.

  When the polymer (a) is directly produced by polymerizing a polymerizable monomer in an aqueous medium, the water-soluble reducing agent used in the present invention includes iron (II), chromium ion, sulfite, hyposulfite. Examples thereof include salts, hydroxylamine, hydrazine, sodium formaldehyde sulfoxylate and the like. Moreover, these 2 types or more can also be used in combination. The usage-amount is 0-10 mass parts normally with respect to 100 mass parts of total amounts of a monomer.

When the polymer (a) is directly produced by polymerizing a polymerizable monomer in an aqueous medium, the oil-soluble reducing agent used in the present invention includes n-butanethiol, n-pentanethiol, n-hexane. Thiol, n-heptanethiol, n-octanethiol, 2-ethylhexanethiol, n-nonanethiol, n-decanethiol, n-undecanthiol, n-dodecanethiol, t-dodecanethiol, benzenethiol, α-toluene Thiols such as thiol are preferred, and in addition, oil-soluble compounds containing groups such as —SO ₂ H, —NHNH ₂ , —COCH (OH) — can be exemplified. Moreover, these 2 types or more can also be used in combination. The usage-amount is 0-10 mass parts normally with respect to 100 mass parts of total amounts of a monomer.

  When the polymer (a) is produced directly by polymerizing a polymerizable monomer in an aqueous medium, suspension polymerization, microsuspension polymerization, emulsion polymerization, microemulsion polymerization of the polymer (a) of the present invention or In miniemulsion polymerization, it is preferable to use an emulsifier for polymerization. When the polymer (a) is anionic, an anionic surfactant and / or a nonionic surfactant is used. When the polymer (a) is cationic, a cationic surfactant and A nonionic surfactant is used.

  Examples of the anionic surfactant include fatty acid soaps, aliphatic or aromatic alkyl sulfonates, alkyl sulfosuccinates, polyoxyethylene alkyl sulfates, polyoxyethylene alkyl aryl sulfates, higher alcohol sulfates, phosphorus Examples include acid ester salts. In addition, for example, Sanyo Chemical Co., Ltd., Eleminol JS-2, JS-5 (trademark), Kao Co., Ltd. Latemulu S-120, S-180A, S-180 (trademark), Daiichi Kogyo Seiyaku Co., Ltd. Aqualon HS-10 (trademark) manufactured by Asahi Denka Kogyo Co., Ltd., Adekaria Soap SE-1025N (trademark), salt of methacrylic acid sulfoalkyl ester, salt of p-styrene sulfonic acid, manufactured by Asahi Denka Kogyo Co., Ltd. Reactive emulsifiers such as ammonium salts, sodium salts, and potassium salts having a phosphate ester group such as rear soap SDX-730, SDX-731, and SDX-334 (trade name) can also be used.

Examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether, polyoxyethylene sorbitan fatty acid ester, oxyethylene oxypropylene block copolymer, and diethanolamine derivative.
Examples of the cationic surfactant include laurylamine hydrochloride, alkylbenzyldimethylammonium chloride, lauryltrimethylammonium chloride, alkylammonium hydroxide, polyoxyethylene alkylamine and the like. Examples of the nonionic surfactant include polyoxyethylene alkyl aryl ether, polyoxyethylene sorbitan fatty acid ester, oxyethylene oxypropylene block copolymer, and the like.

  It is preferable that the usage-amount of these surfactant is 0.05-20 mass% with respect to solid content of a polymer (a). Among the above surfactants, it is preferable to use a reactive emulsifier. In this case, the amount used thereof is the polymer (a) from the viewpoint of emulsifying power and the strength of the coating film obtained from the polymer (a). 0.5-5 mass% of solid content of is preferable, and 1-3 mass% is still more preferable.

  In the production of the curable composition of the present invention, when the polymer (a) is produced by dissolving and / or emulsifying and dispersing a powder resin or the like in an aqueous medium, any method may be used for producing the resin. Polymerization is performed by appropriately using a polymerizable monomer having an epoxy group, a polymerizable monomer having no epoxy group, an initiator, a reducing agent, and the like. Any of radical polymerization, anionic polymerization, cationic polymerization and the like may be used, but radical polymerization is preferable, and it can be obtained by bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization or the like. At this time, the aforementioned water-soluble initiator and / or oil-soluble initiator, water-soluble reducing agent and / or oil-soluble reducing agent may be used. In the case of producing by suspension polymerization or emulsion polymerization, the monomer mixture is pre-emulsified in an aqueous medium in the presence of an emulsifier with an emulsifier such as a homogenizer in order to increase the reaction rate. It is preferable.

  When a polymer (a) is produced by dissolving and / or emulsifying and dispersing a powder resin or the like in an aqueous medium, the molecular weight of the polymer (a) of the present invention is 1,000 to 50,000 in terms of styrene-equivalent number average molecular weight. 1,000 to 10,000 are more preferable, and 1,500 to 8,000 are particularly preferable. The number average molecular weight is preferably 1,000 or more, and the coating film properties such as the acid resistance and solvent resistance of the coating film are excellent, and the crushed polymer is less likely to be fused, so that it is easy to handle. Further, the number average molecular weight is 50,000 or less, and the finished appearance such as smoothness of the coating film is excellent and preferable.

  Further, when the polymer (a) is produced by dissolving and / or emulsifying and dispersing a powder resin or the like in an aqueous medium, the epoxy equivalent of the polymer (a) is preferably in the range of 200 to 5,000 g / equivalent, 200 A range of ˜1,500 g / equivalent is more preferred, and a range of 250 to 1,000 g / equivalent is particularly preferred. When the epoxy equivalent is larger than 200 g / equivalent, the ratio of glycidyl acrylate in the epoxy group-containing polymer does not become too high, and the coating film has flexibility, so that it has excellent adhesion to deformation of the coated plate. When the epoxy equivalent does not exceed 5,000 g / equivalent, the coating performance such as adhesion is excellent and preferable.

  Moreover, when manufacturing a polymer (a) by melt | dissolving and / or emulsifying dispersion | distribution of powder resin etc. in an aqueous medium, the range of 10-200 g / 10min of the melt index of the said polymer (a) is preferable, and 15- 15 The range of 150 g / 10 min is more preferable, and the range of 20 to 100 g / 10 min is particularly preferable. When the melt index is larger than 10 g / 10 minutes, the finished appearance such as the smoothness of the coating film is excellent and preferable. When the melt index does not exceed 200 g / 10 min, the coating film has excellent physical properties such as acid resistance and solvent resistance.

  As the polymer (a) used in the present invention, an epoxy compound other than those described above is represented by the above formula (2), for example, a compound having the above epoxy group via an ether bond, and having an epoxy group via an ester bond. Examples thereof include polymers derived from compounds, compounds in which the epoxy group derived from amines or isocyanuric acid is directly bonded to a nitrogen atom, alicyclic epoxy group-containing compounds, glycidylate group-containing compounds, and the like.

  The glycidyl group is an epoxy compound having an ether bond, for example, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, butanediol diglycidyl ether, pentanediol diglycidyl ether, neopentyl glycol diglycidyl ether, hexanediol. Diglycidyl ether, cyclopentanediol diglycidyl ether, cyclohexanediol diglycidyl ether, cyclohexanedimethanol diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, diethylene glycol diglycidyl ether, trimethylolpropane triglycidyl Ether, pentaerythritol triglycidyl ether, hydride From diglycidyl ether derived from quinone, diglycidyl ether derived from resorcinol, diglycidyl ether derived from catechol, diglycidyl ether derived from bisphenol A, diglycidyl ether derived from bisphenol F, bisphenol AD Diglycidyl ether derived, diglycidyl ether derived from bisphenol S, diglycidyl ether derived from 4,4′-dihydroxybiphenyl, derived from 3,3 ′, 5,5′-tetramethyldihydroxybiphenyl Diglycidyl ether, glycidyl ether compound derived from phenol novolac resin, glycidyl compound derived from cresol novolac resin, and halides and oligomers thereof It is below. Among these, diglycidyl ether derived from bisphenol A is generally “bisphenol A type epoxy resin”, which is liquid or solid depending on the molecular weight, and is easily available as the most widely used compound. And can be suitably used as the curable composition component of the present invention.

  The compounds having a glycidyl group via an ester bond include diglycidyl phthalate, diglycidyl maleate, diglycidyl terephthalate, diglycidyl isophthalate, diglycidyl naphthalene dicarboxylate, diglycidyl biphenyl dicarboxylate, diglycidyl succinate, diglycidyl fumarate, glutar Diglycidyl acid, diglycidyl adipate, diglycidyl suberate, diglycidyl sebacate, diglycidyl decanedicarboxylate, diglycidyl cyclohexanedicarboxylate, triglycidyl trimellitic acid, glycidyl esters derived from dimer acid, and halides and oligomers thereof It is done.

  In addition, as a compound in which a glycidyl group is bonded to a nitrogen atom, triglycidyl isocyanurate, tetraglycidyldiaminodiphenylmethane, triglycidylaminophenol, diglycidylaniline, diglycidyltoluidine, tetraglycidylmetaxylenediamine, tetraglycidylhexamethylenediamine, tetraglycidyl Examples thereof include bisaminomethylcyclohexane, glycidyl compounds derived from hydantoin compounds, and halides and oligomers thereof.

  Examples of the alicyclic epoxy compound include bis (3,4-epoxycyclohexyl) adipate, bis (3,4-epoxycyclohexyl) terephthalate, 3,4-epoxycyclohexyl-3,4-epoxycyclohexanecarboxylate, 4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, bis (3,4-epoxycyclohexylmethyl) oxalate, bis (3,4-epoxy-6-methylcyclohexyl) adipate, bis (3,4-epoxycyclohexyl) Methyl) pimelate, vinylcyclohexene dioxide, and the like.

  The polymer derived from the epoxy group-containing compound has an epoxy group such as a glycidyl group at the terminal, side chain, or branched chain, and the number average molecular weight in terms of styrene is preferably 1,000 to 50,000. 1,000 to 10,000 are more preferable, and 1,500 to 8,000 are particularly preferable. When the number average molecular weight is 1,000 or more, the ratio of epoxy groups in the coating is not too high, and the storage stability of the coating is excellent. When the number average molecular weight does not exceed 50,000, the finished appearance such as smoothness of the coating film is excellent and preferable.

  The epoxy equivalent of the polymer (a) is preferably in the range of 200 to 5,000 g / equivalent, more preferably in the range of 200 to 1,500 g / equivalent, and particularly preferably in the range of 250 to 1,000 g / equivalent. When the epoxy equivalent is larger than 200 g / equivalent, the ratio of glycidyl acrylate in the epoxy group-containing polymer is not too high, and the coating film has flexibility, so that it has excellent adhesion to deformation of the coated plate. Moreover, when the epoxy equivalent does not exceed 5,000 g / equivalent, the coating film performance such as adhesion is excellent.

  The water-soluble and / or water-dispersible polymer of the present invention can be obtained by solubilizing at least a part of the polymer by adding an alkali if it is anionic or by adding an acid if it is cationic. it can. Examples of the alkali used for such solubilization treatment include sodium hydroxide, potassium hydroxide, sodium hydrogen carbonate, organic amines, ammonia and the like, particularly from the viewpoint of improving the water resistance of the coating film after drying. Monoethanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, diethanolamine, Nn-butyldiethanolamine, triisopropanolamine, and morpholines such as morpholine and 4-morpholinoethanol are preferred. Among these, ammonia is preferable as the volatile alkali component. Examples of the acid include hydrochloric acid, sulfuric acid, nitric acid, methanesulfonic acid, p-toluenesulfonic acid, acetic acid, lactic acid, and hydroxyacetic acid. The alkali or acid may be added before, during or after the polymerization.

The polymer (a) used in the present invention may be modified with an acidic phosphate ester or the like, or its hydroxyl group may be modified with a diisocyanate compound or the like.
The polymer (a) of the present invention may be used alone or in combination of two or more, depending on various uses and desired physical properties.

  The curing agent (b) of the present invention means a compound that can react with an epoxy group to form a crosslinked structure. The curing agent used in the present invention is an aliphatic tricarboxylic acid and means a compound in which three carboxyl groups are bonded to a linear or branched hydrocarbon. As a straight chain, 1,2,3-propanetricarboxylic acid, 1,2,3-butanetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,3-pentanetricarboxylic acid, 1,2 , 4-Pentanetricarboxylic acid, 1,2,5-pentanetricarboxylic acid, 1,3,4-pentanetricarboxylic acid, 1,3,5-pentanetricarboxylic acid, 2,3,4-pentanetricarboxylic acid, 1,2 , 5-hexanetricarboxylic acid, 1,1,6-hexanetricarboxylic acid, 1,3,5-hexanetricarboxylic acid, 1,2,6-hexanetricarboxylic acid, 1,3,3-hexanetricarboxylic acid, 1,2 , 4-hexanetricarboxylic acid, 2,4,4-hexanetricarboxylic acid, 1,4,5-hexanetricarboxylic acid, 1,3,4-hexanetricarboxylic acid, 1 3,6-hexanetricarboxylic acid, 2,3,5-hexanetricarboxylic acid, 1,4,8-octanetricarboxylic acid, 1,5,10-nonanetricarboxylic acid, 1,6,12-dodecanetricarboxylic acid, 1, 7,13-tridecanetricarboxylic acid and the like are branched, such as 2-carboxymethyl-1,3-propanedicarboxylic acid, 3-carboxymethyl-1,5-pentanedicarboxylic acid, 3-carboxyethyl-1 , 5-pentanedicarboxylic acid, 3-carboxyethyl-1,6-hexanedicarboxylic acid and the like. Among these, an aliphatic tricarboxylic acid represented by the following formula (1) is preferable.

[Wherein p, r, and s are integers of 0 to 8, q is an integer of 1 to 9, and 1 ≦ p + q + r + s ≦ 9 and {r <s or (r = s and p ≦ q)}]
Examples of the water-soluble aliphatic tricarboxylic acid represented by the above formula (1) include 1, 2, 4
-Butanetricarboxylic acid, 1,2,4-pentanetricarboxylic acid, 1,2,5-
Pentanetricarboxylic acid, 1,3,4-pentanetricarboxylic acid, 1,3,5-
Pentanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3,5-
Hexanetricarboxylic acid, 1,2,6-hexanetricarboxylic acid, 1,2,4-
Hexanetricarboxylic acid, 1,4,5-hexanetricarboxylic acid, 1,3,4-
Hexanetricarboxylic acid, 1,3,6-hexanetricarboxylic acid, 2,3,5-
Hexanetricarboxylic acid, 1,4,8-octanetricarboxylic acid, 1,5,10
-Nonanetricarboxylic acid, 1,6,12-dodecanetricarboxylic acid, etc. are mentioned. Among them, 1,2,5-, 1,3,5-, 1,2,6-, 1,2,4-, 1
, 4,5-, 1,3,4-, and 1,3,6-hexanetricarboxylic acid are preferred because of their high thermal stability. In particular, 1,3,6-hexanetricarboxylic acid is about 110 ° C.
In addition to being excellent in physical properties such as having a melting point of, and excellent in curing properties, it is most preferable in view of being easily industrially available as described below.

In the present invention, the above aliphatic tricarboxylic acid may be used alone or in combination of two or more.
There is no restriction | limiting in particular in the manufacturing method of the aliphatic tricarboxylic acid used in this invention. 1,3,6-hexanetricarboxylic acid can be obtained by, for example, trinitrating acrylonitrile, which is produced on a large scale industrially, or trinitrile compounds obtained when producing adiponitrile by electrolytic dimerization of acrylonitrile. It can be easily obtained by hydrolysis using an alkali such as acid or caustic soda.
In the present invention, a curing agent other than aliphatic tricarboxylic acid, for example, a curing agent for a general epoxy resin capable of forming a crosslinked structure by reacting with a carboxyl group-containing compound, an acid anhydride, or an epoxy group other than these. One or more of these may be used in combination with an aliphatic tricarboxylic acid depending on various applications.

The carboxyl group-containing compound that can be used as a curing agent other than the aliphatic tricarboxylic acid is a compound having two or more carboxyl groups in the molecule, and it cannot be generally stated depending on the proportion of the curing agent used. Any aliphatic, aromatic, or alicyclic polyvalent carboxylic acid can be preferably used as long as it has solubility in water.
Examples of the aliphatic polyvalent carboxylic acid include glutaric acid, adipic acid, suberic acid, sebacic acid, azelaic acid, decanedicarboxylic acid, hexadecanedicarboxylic acid, eicosanedicarboxylic acid and tetraeicosanedicarboxylic acid, acrylic acid and methacrylic acid as components. Copolymer, polyester, polyamide and the like.

Examples of the aromatic polyvalent carboxylic acid include isophthalic acid, phthalic acid, trimellitic acid, 1,3,5-benzenetricarboxylic acid and the like. Furthermore, examples of the alicyclic polyvalent carboxylic acid include hexahydrophthalic acid, tetrahydrophthalic acid, 1,4-cyclohexanedicarboxylic acid, 1,2,3,4-cyclobutanetetracarboxylic acid, and the like.
Examples of the acid anhydride include anhydrides of the above-mentioned aliphatic, aromatic, and alicyclic polycarboxylic acids, and anhydrides of these polyvalent carboxylic acids and monovalent carboxylic acids.

  Furthermore, examples of a general epoxy resin curing agent that can react with an epoxy group to form a crosslinked structure include dicyandiamides, dihydrazides, imidazoles, and polyhydrates. Further, triazines such as tris (alkoxycarbonylamino) triazine, polycarboxylic acids including organosilyl groups, acrylic resins having two or more carboxyl groups in the molecule, or resins such as polyester resins are also other than aliphatic tricarboxylic acids. It can be used as a curing agent.

The content of the aliphatic tricarboxylic acid in the total amount of the curing agent used in the present invention is 0.1 to 100% by mass. Preferably, it is 1-100 mass%, Most preferably, it is 10-100 mass%, Most preferably, it is 50-100 mass%. When the content of the aliphatic tricarboxylic acid is 0.1% by mass or more, a sufficient curing rate can be obtained, and the resulting cured product is preferable because of excellent mechanical properties.
In the water-based curable composition of the present invention, the aliphatic tricarboxylic acid to be used depends on when used in combination with other curing agents, but usually the aliphatic tricarboxylic acid relative to the epoxy group of the polymer having an epoxy group. Can be used in an amount of 0.01 to 5 equivalents. In particular, 0.1 to 3.0 equivalents are preferable, and 0.3 to 2 equivalents are preferable in order to obtain a cured product having significantly improved aliphatic tricarboxylic acid curability and improved crosslink density and excellent mechanical properties. 0.0 equivalent is more preferable, and 0.5 to 1.5 equivalent is particularly preferable.

  In general, a curable composition composed of an epoxy compound and a carboxyl group-containing compound is used with an equivalent ratio of carboxyl group to the epoxy group or a composition ratio in the vicinity thereof, and the equivalent ratio deviates significantly from 1. In some cases, the gel fraction of the cured product tends to decrease. In the case of the water-based curable composition of the present invention, even when the equivalence ratio deviates greatly from 1, a sufficient gel fraction is exhibited by short-time curing.

  In the present invention, when the polymer (a) has a hydroxyl group and / or a carboxyl group, an auxiliary cross-linking agent or a modifier having at least one functional group capable of reacting with the hydroxyl group or the carboxyl group is added. Can do. These include blocked isocyanates, alkylated melamine formaldehyde resins, alkylated glycoluril resins, hydantoin epoxides, triglycidyl isocyanurates, aliphatic glycidyl ethers, aliphatic glycidyl esters, cyclic aliphatic epoxides, hydrogenated bisphenol A and epichloro. Epoxy resins derived from hydrin, oxazolines, 2-4 functional β-hydroxyalkylamides and the like are included.

  In addition, the water-based curable composition of the present invention includes a compound having one epoxy group in the molecule, an acrylic resin having one carboxyl group and / or one or more hydroxyl groups, a polyester resin, or other heavy compounds. Compounds such as coalescence can also be added.

The organic solvent (c) of the present invention will be described.
The organic solvent (c) used in the aqueous curable composition of the present invention means an organic solvent that can dissolve both the polymer (a) and the curing agent (b). The organic solvent (c) used in the present invention comprises at least one selected from compounds having at least one ketone group, hydroxyl group, ether group, and ester group in the same molecule and / or one or more of the same and / or different groups. The proportion of the compound in the organic solvent is 0.1 to 100% by mass.

Specific examples of the compound having a ketone group include acetone, methyl acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone, methyl isobutyl ketone, methyl-n-amyl ketone, diethyl ketone, diisobutyl ketone, and acetone oil. Acetonyl acetone, diacetone alcohol, mesityl oxide, phorone, isophorone, acetophenone, and the like. Acetone, methyl acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone, methyl isobutyl ketone, diethyl ketone, diacetone alcohol, mesityl oxide, and acetonyl acetone are preferred. Examples of the compound having a ketone group include linear, branched, cyclic, aliphatic, aromatic, saturated and unsaturated structures.
Among the compounds having a ketone group, the solubility of the curing agent (b) decreases as the number of carbon atoms increases. Preferably, the carbon number is 8 or less, more preferably 7 or less, and particularly preferably 6 or less. It is a compound having a ketone group.

  Specific examples of the compound having a hydroxyl group include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, n-amyl alcohol, isoamino alcohol, tert-butyl alcohol, and 2-methyl-1-butanol. Secondary amyl alcohol, 3-pentanol, n-hexanol, methyl amyl alcohol, 2-ethylbutanol, n-heptanol, 2-heptanol, 3-heptanol, 2-octanol, 2-ethylhexanol, 3, 5, 5 -Trimethylhexanol, nonanol, n-decanol, undecanol, n-dodecanol, trimethylnonyl alcohol, tetradecanol, cyclohexanol, 2-methylcyclohexanol, furfuryl alcohol, tetrahydrofur Lil alcohol, alpha-terpineol, benzyl alcohol, monoacetin, diacetin, triacetin, fusel oils, and the like can be suitably used.

Examples of the compound having a hydroxyl group include those having a linear, branched, cyclic, aliphatic, aromatic, saturated or unsaturated structure.
Among the compounds having a hydroxyl group, the solubility of the curing agent (b) decreases as the number of carbon atoms increases. Preferably, the carbon number is 8 or less, more preferably 7 or less, and particularly preferably 6 or less. It is a compound having a hydroxyl group.

  Furthermore, polyhydric alcohols and derivatives thereof can also be preferably used. Specifically, ethylene glycol, methyl cellosolve, methyl cellosolve acetate, ethyl cellosolve, diethyl cellosolve, cellosolve acetate, ethylene glycol isopropyl ether, butyl cellosolve, dibutyl cellosolve, butyl cellosolve acetate, ethylene glycol isoamyl ether, hexyl cellosolve, methoxymethoxyethanol, ethylene Glyco-r monoacetate, ethylene glycol diacetate, formic acid monoglycol, digisan glycol, diethylene glycol, methyl carbitol, ethyl carbitol, carbitol acetate, diethylene glycol methyl ether, diethyl carbitol, diethylene glycol acetate, triethylene glycol monomethyl ether, propylene G Coal, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, 1-butoxy ethipropanol, propylene glycol monoacetate, propylene glycol formate diester, propylene glycol acetate diester, 1-methoxy-2-propanol acetate, 1- Ethoxy-2-propanol acetate, propylene glycol-n-propyl ether, propylene glycol isopropyl ether, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, trimethylene glycol, butanediol, hexylene glycol, octylene Glycol, glyceryl monoacetate, etc. It is. These polyhydric alcohols and polyhydric alcohol derivatives are derived from polyhydric alcohols in addition to those having two or more hydroxyl groups in the same molecule, and have the same molecule as the hydroxyl group, ether group and ester group. Those having one or two or more at the same time are also included.

  The polyhydric alcohol and derivatives thereof are preferably those having a small ratio of carbon number to the total of each group. That is, it is 5 / group or less, more preferably 4 / group or less, and particularly preferably 3 / group or less. When the number of carbon atoms exceeds 5 with respect to the group, the solubility of the curing agent (b) is lowered, and the curing agent is precipitated during storage of the paint, which is not preferable.

Specific examples of the compound having an ether group include ethyl ether, isopropyl ether, n-butyl ether, hexyl ether, 1,2-propylene oxide, dioxolane, tetrahydrofuran, 4-methyldioxolane, 1,4-dioxane, dimethyldioxane. , Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol diethyl ether, ethylene glycol monobutyl ether, ethylene glycol mono-n-hexyl ether, ethylene glycol monophenyl ether, ethylene glycol mono-2-ethylbutyl ether, ethylene glycol dibutyl ether , Diethylene glycol monomethyl ether, diethylene glycol diethyl ether, diethylene glycol Monobutyl ether, diethylene glycol dibutyl ether, diethylene glycol mono -n- hexyl ether, ethoxy triglycol, monopropylene glycol methyl ether, dipropylene glycol methyl ether, tripropylene glycol methyl ether, terpene ether, or the like can be suitably used.
The compound having an ether group is preferably a compound having a small ratio of carbon number to the total of the ether group and other groups. That is, it is 5 / group or less, more preferably 4 / group or less, and particularly preferably 3 / group or less. When the number of carbon atoms does not exceed 5 with respect to the group, the solubility of the curing agent (b) is improved, and the storage stability of the paint is preferably increased.

  Next, specific examples of the compound having an ester group include methyl formate, ethyl formate, propyl formate, butyl formate, isoamyl formate, glycol formate, methyl acetate, ethyl acetate, acetic acid-n-butyl, isobutyl acetate, acetic acid. -N-amyl, isoamyl acetate, 3-methoxybutyl acetate, methyl amyl acetate, 2-ethyl amyl acetate, 2-ethyl hexyl acetate, benzyl acetate, cyclohexyl acetate, methyl cyclohexyl acetate, methyl acetoacetate, ethyl acetoacetate, ethylene glycol monomethyl ether Ethylene glycol monoethyl ether, methyl propionate, ethyl propionate, butyl propionate, isoamyl propionate, methyl lactate, ethyl lactate, butyl lactate, and the like. More preferably, it is an ester compound, which is a compound having at least one ether group and hydroxyl group in the same molecule.

The boiling point of the organic solvent (c) is preferably in the range of 20 to 250 ° C., more preferably in the range of 25 to 200 ° C. in any compound having the ketone group, hydroxyl group, ether group or ester group. Especially preferably, it is 30-180 degreeC. When the boiling point of these organic solvents is 20 ° C. or higher, the paint is not dried too quickly and the finish of the coating film surface is good. In addition, when the boiling point does not exceed 250 ° C., the drying temperature of the coating film does not become too high, and discoloration of the coating film and poor drying hardly occur during baking.
In the organic solvent (c), the solubility of the curing agent (b) is preferably 10% by mass or more, and more preferably 20% by mass or more. When the solubility of the curing agent (b) in these organic solvents is 10% by mass or more, it is preferable that the curing agent (b) hardly precipitates during drying and the finish of the coating film surface is good.

As the organic solvent (c) in the present invention, propylene glycol monomethyl ether can be used particularly preferably from the above two points.
The organic solvent (c) of this invention may be used independently, and 2 or more types may be mixed and used for it. Furthermore, the total content of the compounds having a ketone group, a hydroxyl group, an ether group, and an ester group in the organic solvent used in the present invention is preferably in the range of 0.1 to 100% by mass. More preferably, it is 1-100 mass%, Most preferably, it is the range of 5-100 mass%. When the content is 0.1% by mass or more, the solubility of the polymer (a) and the curing agent (b) is sufficient, and a uniform coating is obtained, which is preferable.

  The organic solvent (c) of the present invention can be used in combination with one or more other organic solvents as long as the effects of the present invention are not hindered. For example, amides N, N′-dimethylformamide, formamide, acetamide, etc., hydrocarbons toluene, xylene, ethylbenzene, cyclohexane, n-hexane, etc., halogenated hydrocarbons methylene chloride, ethyl chloride, Examples include isopropyl chloride, chlorobenzene, dichlorobenzene and the like. These organic solvents are not limited to those listed above. The above amides, hydrocarbons, and halogenated hydrocarbons are added to adjust the drying property of the paint, and to adjust or improve the viscosity, fluidity, handling property, paintability, etc. of the paint. Can be added in the range of 0 to 70% by mass of the total content of the organic solvent. When it does not exceed 70% by mass in the organic solvent, the solubility of the curing agent (b) becomes good, a uniform paint is obtained, and the storage stability of the paint is ensured, which is preferable.

  The mass of the organic solvent (c) of the present invention is preferably in the range of 0.1 to 40 parts by mass when the sum of the masses of the polymer (a) and the curing agent (b) is 100 parts by mass. More preferably, it is the range of 0.5-30 mass parts, Most preferably, it is the range of 1-20 mass parts. When the organic solvent (c) in the paint is 0.1 parts by mass or more, the solubility of the polymer (a) and the curing agent (b) is improved, and the paint is not uneven when dried. An excellent coating film is obtained. Moreover, when the organic solvent (c) does not exceed 40 parts by mass, it is preferable because the drying process does not require high temperature and / or long time and the amount of organic solvent released into the atmosphere can be suppressed.

  The mass of the water (d) of the present invention is adjusted so as to be larger than the mass of the organic solvent (c) and the solid content concentration of the aqueous curable composition of the present invention is 10 to 70% by mass. Is preferred. More preferably, the solid content concentration is adjusted to 15 to 60% by mass, and particularly preferably the solid content concentration is adjusted to 20 to 55% by mass.

  Furthermore, the water-based curable composition of the present invention includes additives that are usually blended in paints and the like according to various uses, for example, reactive diluents, antioxidants, dispersants, dispersion aids, curing accelerators (curing Catalysts), fillers, reinforcing agents, pigments, mold release agents, flow control agents, plasticizers, UV absorbers and other agents that can prevent coating deterioration due to UV rays, water resistance agents, etc. should be added as necessary. Can do. In particular, water-based paints for automobiles and / or water-based paints for clear topcoats produced by blending various additives with the water-based curable composition of the present invention can be suitably used for such applications.

  The reactive diluent used in the present invention can be blended within a range not impeding the effects of the present invention for the purpose of adjusting the solid content concentration, adjusting the viscosity of the coating material, controlling the crosslinkability, and the like. Specific examples of reactive diluents include butyl glycidyl ether, allyl glycidyl ether, 2-ethylhexyl glycidyl ether, styrene oxide, phenyl glycidyl ether, cresyl glycidyl ether, p-sec-butylphenyl glycidyl ether, glycidyl methacrylate, tertiary Carboxylic acid glycidyl ester etc. are mentioned, It can use suitably.

  The antioxidant used in the present invention has a function of suppressing yellowing of the coating film by heat when the coating film is baked and cured after the aqueous curable composition of the present invention is applied to the object. It is what you have. Examples of the antioxidant (heat stabilizer) include hindered phenols, phosphoruss, lactones, vitamin Es, and sulfurs. Specific examples include Irganox 1010, Irganox 1222, Irganox 259, Irganox 565, Irganox 1520L, Irganox PS800FL, Irgafos P-EPQ, Irgafos 38 (all available from Ciba Specialty Chemicals). .

  As for the addition rate of antioxidant, 10 mass ppm-10 mass% are preferable with respect to an aqueous curable composition. More preferably, it is 100 mass ppm-8 mass%, Most preferably, it is 1000 mass ppm-5 mass%. When the addition ratio is 10 mass ppm or more, a sufficient antioxidant effect is obtained, and the coating film is preferably not yellowed during baking and curing. When the addition rate does not exceed 10% by mass, the coating film is hardly colored due to the coloring of the antioxidant itself, and the physical properties of the coating film are deteriorated due to the addition rate of the antioxidant being too high. Hateful.

  Dispersing agents include polycarboxylic acid alkali metal salts, amine salts and ammonium salts, polyvinyl alcohol, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, polyoxyethylene alcohol ether, polyoxyethylene. Examples include sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, sorbitan fatty acid ester, glycerin sorbitan fatty acid ester, alkali metal salt of alkyl sulfonic acid, sodium pyrophosphate, sodium hexametaphosphate, and the like. It is blended by mass%.

Examples of the curing accelerator include imidazoles such as 2-ethyl-4-methylimidazole, 2-methylimidazole, and 1-benzyl-2-methylimidazole, dimethylcyclohexylamine, benzyldimethylamine, and tris (diaminomethyl) phenol. Tertiary amines, diazabicycloalkenes such as 1,8-diazabicyclo [5.4.0] undecene-7 and their salts, zinc octylate, alkyl titanate compounds, tin octylate, monoalkyltinic acid, etc. Tin compounds, organometallic compounds such as aluminum acetylacetone complex, organophosphorus compounds such as triphenylphosphine and triphenyl phosphite, boron trifluoride, boron trifluoride diethyl ether complex, boron trifluoride piperidine complex, tri Phenylborate Boron-based compounds of the above, metal halides such as zinc chloride and stannic chloride, quaternary ammonium compounds, alkali metal alcoholates such as sodium alcoholate of 2,4-dihydroxy-3-hydroxymethylpentane, anacardic acid and Examples thereof include phenols such as salts, cardol, cardanol, phenol, nonylphenol and cresol, blocked strong acid catalysts, and the like.

Examples of fillers and reinforcing agents include coal tar, bitumen, woven fabric, glass fiber, asbestos fiber, boron fiber, carbon fiber, aramid fiber, mineral silicate, mica, quartz powder, aluminum hydroxide, bentonite, kaolin, and silicate aerogel. And metal powders such as aluminum powder and iron powder.
As pigments, azo pigments, copper phthalocyanine pigments, basic dyeing lakes,
Acid dyed lake, mordant dye pigment, construction dye pigment, quinacridone pigment,
Dioxazine pigments, carbon black, chromate, ferrocyanide, titanium oxide, mica powder, pearlite, selenium sulfide compounds, silicates, carbonates such as calcium carbonate, phosphates, metal powders, color pigments, sulfuric acid Examples of extender pigments include barium, barium carbonate, gypsum, alumina white, clay, silica, talc, calcium silicate, and magnesium carbonate. Silica may be added as a gloss modifier for the coating film.

Examples of the mold release agent and flow regulator include silicone, aerosil, colloidal hydrous aluminum silicate, wax, paraffin emulsion, stearates such as calcium stearate, calcium carbonate, talc and the like.
Further, as plasticizers, pine oil, low-viscosity liquid polymer, rubbery material, tar, polysulfide, urethane prepolymer, polyol, diethyl phthalate, dibutyl phthalate, epichlorohydrin polymer, dioctyl phthalate, dioctyl adipate, tricresyl phosphate Etc.

Examples of ultraviolet absorbers include benzotriazole-based, triazine-based, benzophenone-based, benzoate-based, and hindered amine-based light stabilizers such as Tinuvin (commercially available from Tinuvin, Ciba Specialty Chemicals). Examples include Tinuvin 144, Tinuvin 234, Tinuvin 900, Tinuvin P, Tinuvin 329, Tinuvin 1577, Tinuvin 120 (all available from Ciba Specialty Chemicals).
Examples of water-proofing agents include formalin, hexamine, melamine resin, urea resin, glyoxal and the like.

  Furthermore, dryers such as cobalt naphthenate, anti-skinning agents such as methoxyphenol and cyclohexane oxime, thickeners such as highly polymerized linseed oil, organic bentonite, silica, side effects such as benzoin, Modaflow (manufactured by Monsanto) ), Regiflow (Resiflow, manufactured by Worlee), Achronal (Acronal, manufactured by BASF), etc., flame retardants such as antimony trioxide, bromine compounds, aluminum hydroxide, dyes, waxes, antioxidants (anti-antioxidants) Oxidizing agent), light stabilizer, radical scavenger, heat stabilizer, polyglycol, fatty acid ester, phosphate ester, defoaming agent such as silicone oil, degassing agent (degassing agent), acrylic oligomer, funnel oil, Leveling agents such as dicyandiamide and urea, flow agents, colorants, dioxide Tan, viscosity modifier, pH adjuster, preservative, emulsifier, surfactant, wetting agent, film-forming aid, rust inhibitor, surface modifier, matting agent, biocide, biocide, disinfectant, flow Spreading aids, neutralizing agents, amines, water retention agents, auxiliaries, epoxy resins, bismuth compounds, fine powdered silica, baked gypsum, imidazoline compounds, crosslinked resin fine particles, polyester resin powder coatings, thermal latent cationic polymerization An initiator, a hydrotalcite compound, and other various additives can be added. One or more of these additives can be arbitrarily applied in an application amount within a range that does not impair the effects of the present invention. Moreover, there is no restriction | limiting in particular in the method of mix | blending these additives, A conventional compounding method is applicable.

  When the aqueous curable composition of the present invention is produced by pulverizing the resin, any pulverization method may be used, such as a roller mill, a three-roll mill, a super mill, a spike mill, a mighty mill, a sand mill, a hammer mill, a ball mill, etc. A dry or wet pulverizer can be used. Moreover, the method of granulating from the solution or dispersion liquid of a polymer (a) can also be used. The particles obtained by these methods may be further compressed, pulverized, agglomerated and granulated, or brought into contact with a hot air stream to make the particles spherical or classified. These operations may be arbitrarily combined or repeated. The water-soluble aliphatic tricarboxylic acid may be dissolved in an aqueous medium from the beginning, or may be added after the polymer (a). When added later, it is preferably added after dissolving in an aqueous medium. Other additives such as a curing agent and a dispersant, an aqueous medium for adjusting the concentration, and the like may be appropriately added in the course of manufacturing the coating material.

When the water-based curable composition of the present invention is applied as a paint, commonly used coating methods such as roll coating, curtain flow coating, spray coating, electrostatic coating, etc. are used, and are not particularly limited. .
When the water-based curable composition of the present invention is used as a paint, it can be cured with energy such as heat, ultraviolet rays, and electron beams. For example, when cured by heating, a curing reaction is usually performed in the range of 150 to 250 ° C. However, a coating film having good physical properties can be obtained within a practical curing time range even in a recently desired low temperature curing temperature range of 150 ° C. or less. Although the curing time depends on the composition, it is usually in the range of 20 minutes to 200 hours, but can be carried out in 20 minutes or less.
The thickness of the coating film obtained by using the aqueous curable composition of the present invention as a paint is usually in the range of 1 to 1000 μm, preferably in the range of 1 to 500 μm, more preferably in the range of 1 to 200 μm.

The water-based curable composition of the present invention can be used for casting molding agents, semiconductor encapsulants, insulating paints, electrical insulating materials such as laminates, composite matrix resins, adhesives, sealing agents, coating agents, paints, etc. Although it can be suitably used, it can be particularly preferably used as a water-based paint.
The coating film obtained from the aqueous curable composition of the present invention has an appearance such as smoothness, sharpness, transparency, physical strength such as hardness, impact resistance, flex resistance, scratch resistance, and solvent resistance. It has excellent chemical properties such as acidity, acid rain resistance, and weather resistance, and can be suitably applied as a protective material for metals, concrete drive, wood, plastic materials, and the like. Therefore, the water-based paint containing the water-based curable composition of the present invention is suitably used for home appliances, electrical equipment, automobile parts, automobile outer panels, ships, steel furniture, water supply materials, cans, roads, construction and civil engineering materials, etc. In particular, it can be suitably used as a water-based paint for automobiles. In particular, as a clear paint containing no pigment component, for example, it can be preferably used in water-based paints for clear top coats such as vending machines, road materials, aluminum wheels, automobile parts, and automobile outer panels.

For example, a so-called two-coat, one-bake automotive topcoat that coats a base coating on a baseplate or a baseplate with an undercoat and an intermediate coat, and then applies a clear paint before curing, and simultaneously cures the base paint and the clear paint. Can be used for clear paint.
The first base paint is applied to the base plate or undercoat and intermediate coat, and then cured, and then the second base paint is applied, and then the clear paint is applied before the second base paint and the second base paint and clear paint are applied. Can also be used for the clear coating of the so-called 3-coat 2-bake automobile top coat, which simultaneously cures.
The first base paint is applied on the base plate or the base plate with the undercoat and the intermediate coat, the second base paint is applied before the curing, the clear paint is applied before the curing, the first base paint, The two-base paint and the clear paint can be used for the clear coating of the so-called three-coat one-bake automobile top coat that simultaneously cures the clear paint.

Apply the intermediate paint on the undercoated plate, apply the base paint before curing, then apply the clear paint before curing, and cure the intermediate paint, base paint, and clear paint simultaneously. It can also be used for the so-called 3-coat 1-bake clear paint for automotive intermediate coating and top coating.
An automotive topcoat that is cured by applying an overcoat clear paint on a baseplate, intermediate coat, and topcoat (base and clear) coated plate, or on a baseplate and clear coat (base and clear) coated plate. Can also be used for overcoat clear paint.

Hereinafter, the present invention will be described with reference to examples and comparative examples.
The measuring methods of various physical properties used in Examples and Comparative Examples are as follows.
[1] Measurement of particle size:
An ultrafine particle size analyzer (UPA) was used.
Model: Nikkiso Co., Ltd. Microtrac UPA MODEL; 9230

[2] Number average molecular weight:
It calculated | required from the polystyrene standard calibration curve using the gel permeation chromatography. As the measurement sample, each sample (dried product) was dissolved in tetrahydrofuran to a concentration of about 0.1% by mass.
(Used equipment)
-GPC device: HLC-8120GPC manufactured by Tosoh Corporation
-Column: TSKgel GMH _HR- N manufactured by Tosoh Corporation
Shodex GPC KF-801 Showa Denko K.K.
TSKgel G-1000H _XL x 2 manufactured by Tosoh Corporation
Placed in series-Column temperature: 40 ° C
・ Developing solution: Tetrahydrofuran ・ Developing solution flow rate: 1.0 ml / min

[3] Epoxy equivalent A 0.1 ml-1.0 g sample (dried product) was precisely weighed into a 100 ml Erlenmeyer flask, and a stir bar was added.
Subsequently, about 50 ml of n-propyl alcohol, about 4 ml of benzyl alcohol, and about 3 ml of 0.04% bromothymol blue indicator were added, and a reflux condenser was attached, and the mixture was refluxed with stirring on a stirrer equipped with a hot plate. Further, under reflux, 3.0 g of potassium iodide was dissolved in 10 ml of water and added (blue color). The solution was titrated with 1N or 0.2N hydrochloric acid under reflux, and when the yellow color was maintained for 30 seconds, the epoxy equivalent was determined by the following formula.
Epoxy equivalent (g / eq) = sample mass (g) × 1000 / (normality of hydrochloric acid
(N) x titer (ml))

[4] Melt index (MI)
Measurement was performed according to JIS K7210 using a melt indexer (C-5059D-1 type, manufactured by Toyo Seiki Co., Ltd.). After raising the temperature to 125 ° C, insert an orifice with an inner diameter of 2.095 ± 0.005 mm, add 5 g of the dried sample, insert a plunger, attach a stopper to the outlet of the orifice, and apply a load of 225 g for 5 minutes. Retained. After 5 minutes, a load of 1935 g was applied (total load 2160 g), and the time t (second) when the plunger moved 2.5 cm was measured with a timer. The resin that flowed out was collected, the mass W (g) was measured, and the melt index (g / 10 min) was determined by the following formula.
MI (g / 10 min) = W (g) × 600 (seconds) / t (seconds)

[5] Glass transition temperature (Tg)
It calculated | required from the differential heat curve obtained by DSC (differential scanning calorimetry). DSC measurement is performed by using a sample (dried material) of about 5.0 mg, holding it at −10 ° C. for 1 minute in a nitrogen atmosphere, and then increasing the temperature to 130 ° C. at a temperature increase rate of 10 ° C./min. did.
Device: Differential Scanning
Calorimeter DSC7
(Manufactured by PERKIN-ELMER)

[6] Solid content A non-volatile content (mass%) at 105 ° C. for 3 hours was measured.
[7] Gel fraction The baked coating film was subjected to a Soxhlet extraction tester using acetone as a solvent for 8 hours, and the mass fraction of the insoluble portion was defined as the gel fraction (%).
[8] Smoothness and gloss of the coating film The surface of the coating film was evaluated with the naked eye.
[9] Vividness The surface of the coating film was evaluated with the naked eye.
[10] Transparency A paint was applied to a glass plate, and the transparency was evaluated with the naked eye. Good ones were marked with a circle, and poor ones with a x.

[11] Specular Gloss The specular reflectance (%) of 60 to 60 degrees was measured using a gloss meter GM-268 (manufactured by Minolta Co., Ltd.).
[12] Erichsen value After placing the coated plate in a constant temperature and humidity chamber (20 ° C, 75% RH) for 1 hour, attach the coating film to the Eriksen tester with the coating surface facing outward, and attach a punch with a radius of curvature of about 10 mm. Extrude at a specified distance from the back surface of the test plate at a speed of about 0.1 mm per second so that the speed is as uniform as possible. Whether or not the protruding portion of the coating film had cracks or peelings was examined with the naked eye immediately after extrusion, and expressed as the maximum number of mm when there was no abnormality in the coating film.
[13] Pencil hardness It was performed in accordance with the pencil scratch value tester method of JISK5400.
[14] Impact resistance The maximum dropping distance (cm) that does not cause cracking or peeling on the coated surface was shown by a DuPont impact tester (stroke center 1/2 inch, load 500 g).

[15] Flexibility Measured according to JIS 5400 (curvature radius 5 mm). No abnormality was indicated by ○, and occurrence of cracking was indicated by ×.
[16] Solvent resistance The coated surface was rubbed 50 times back and forth with a cotton swab soaked with xylol, and the coated surface state was evaluated with the naked eye.
[17] Water resistance The test pieces were immersed in water for 18 hours and then taken out, and visually observed to evaluate the presence or absence of abnormalities such as wrinkles, blisters, cracks, and peeling. No abnormality was indicated by ○, slight abnormality was indicated by Δ, and abnormality was indicated by ×.

[18] Acid resistance 0.4 ml of 40% by mass sulfuric acid was dropped on the test coating plate, heated for 15 minutes on a hot plate heated to 85 ° C., washed with water, the coated surface was observed, and evaluated according to the following criteria. .
A: There is no change by visual observation.
○: A slight difference is observed between the dripping portion and the non-dropping portion, but there is no etching.
(Triangle | delta): A slight level | step difference is recognized by the boundary of a dripping part and a non-dropping part.
X: The thing by which clear etching is recognized by visual observation.
[19] Salt water resistance The test piece was immersed in a 3 w / v% sodium chloride aqueous solution for 96 hours, then taken out, washed with water, and after 2 hours, the presence or absence of abnormalities such as swelling, rust, cracking, and peeling was evaluated by visual observation. No abnormality was indicated by ○, slight abnormality was indicated by Δ, and abnormality was indicated by ×.

[20] Weather resistance Using a Weather-O-meter ci35 (manufactured by ATLAS ELECTRIC DEVICE Co.), xenon arc irradiation was performed for 250 hours under a black panel of 63 ° C., 60 W / m ² and rain conditions. The 60 ° gloss (gloss) on the surface of the cured body before and after irradiation was measured to determine the gloss retention (percentage after irradiation and before irradiation).
[21] Adhesiveness The adhesion state of the coating film was visually observed by a cross-cut tape method according to JIS standard K5400. Actually, 100 squares having a size of about 1 mm and 1 mm were produced with a cutter knife, and “number of squares not peeled off with tape / 100 squares” was evaluated.

[22] Scratch resistance The state of the coated surface of the coated plate after observing the car with the test coated plate affixed to the roof five times with a car wash was observed. The car wash machine used was “PO20FWRC” manufactured by Yasui Industry. The evaluation criteria are as follows.
A: Scratches are hardly found by visual observation.
○: Scratches are found slightly, but the degree is light.
Δ: Scratches are noticeable by visual observation.
X: Scratch is clearly noticeable by visual observation.

[Color base paint B]
A white organic solvent-type paint containing a hydroxyl group-containing polyester resin, a melamine resin, a titanium white pigment and aluminum flakes. A toluene / xylene / methanol / ethyl acetate mixed solvent having a boiling point of 80 to 100 ° C. was used as the organic solvent. Munsell color chart N value of the coating film 8.0, solid content 35% by mass, viscosity 12 seconds / Ford cup # 4/20 ° C.

[Pearl base paint C]
A light-interfering organic solvent-type paint containing a hydroxyl group-containing polyester resin, a melamine resin, and titanium oxide-coated mica flakes. A toluene / xylene / methanol / ethyl acetate mixed solvent having a boiling point of 80 to 110 ° C. was used as the organic solvent. Solid content 35% by weight, viscosity 12 seconds / Ford Cup # 4/20 ° C.

[Epoxy group-containing acrylic resin polymer]
[Example 1]
A mixture of a monomer and a polymerization initiator consisting of 224 parts by weight of methyl methacrylate, 152 parts by weight of n-butyl acrylate, 474 parts by weight of glycidyl methacrylate, 150 parts by weight of styrene, and 100 parts by weight of azobisisobutyronitrile. The solution was dropped into 1000 parts by mass of toluene at 110 ° C. over about 30 minutes, and polymerized for 5 hours from the end of the dropping while maintaining the internal temperature at 110 ° C. The resulting solution was depressurized to remove the solvent to obtain a glycidyl group-containing methacrylic resin A having a number average molecular weight of 1,250, an epoxy equivalent of 300 g / equivalent, MI of 85 g / 10 minutes, and Tg of 43 ° C.

[Example 2]
Polymerization was carried out in the same manner as in Example 1 using 184 parts by mass of methyl methacrylate, 300 parts by mass of n-butyl methacrylate, 285 parts by mass of glycidyl methacrylate, 231 parts by mass of styrene, and 68 parts by mass of azobisisobutyronitrile. A glycidyl group-containing methacrylic resin B having a number average molecular weight of 4,800, an epoxy equivalent of 500 g / equivalent, an MI of 65 g / 10 minutes, and a Tg of 56 ° C. was obtained.

Example 3
Polymerization was conducted in the same manner as in Example 1 using 347 parts by mass of methyl methacrylate, 270 parts by mass of n-butyl methacrylate, 203 parts by mass of glycidyl methacrylate, 180 parts by mass of styrene, and 18 parts by mass of azobisisobutyronitrile. A glycidyl group-containing methacrylic resin C having a number average molecular weight of 11,000, an epoxy equivalent of 700 g / equivalent, an MI of 28 g / 10 minutes, and a Tg of 63 ° C. was obtained.

Example 4
In a reaction vessel equipped with a stirrer, a reflux condenser, a dropping tank and a thermometer, 600 parts by mass of water, 3 parts by mass of Emulgen 120 (non-ionic surfactant manufactured by Kao Corporation), 0.3 parts by mass of ammonium persulfate The mixture was charged, heated to 80 ° C., and purged with nitrogen. To this reaction vessel, 200 parts by mass of styrene, 345 parts by mass of methyl methacrylate, 218 parts by mass of butyl acrylate, 37 parts by mass of 2-hydroxyethyl acrylate, 200 parts by mass of glycidyl methacrylate, 585 parts by mass of water, and 32 parts by mass of Emulgen 120 Parts, Perex OT-P (Kao Co., Ltd. anionic surfactant) 6 parts by mass, Emar NC (Kao Co., Ltd. anionic surfactant) 1 part by mass, ammonium persulfate 3 parts by mass, sodium bicarbonate 1 The mixture consisting of parts by mass was emulsified and stirred at 6000 rotations of the homogenizer, and this emulsified mixture was allowed to flow from the dropping tank into the reaction vessel over 3 hours while maintaining 80 ° C. After the inflow was completed and stirring was continued at 80 ° C. for 2 hours, the mixture was cooled to room temperature to obtain a water-dispersible polymer D. The solid content was 46.9%, the particle size was 0.12 μm, the number average molecular weight was 400,000, and the epoxy equivalent was 770 g / eq.

Example 5
Polymerization was carried out in the same manner as in Example 4 except that 30 parts by mass of n-dodecyl mercaptan was added to the emulsified mixture to obtain a water-dispersible polymer E. The solid content was 47.5%, the particle size was 0.13 μm, the number average molecular weight was 6100, and the epoxy equivalent was 790 g / eq.

Example 6
In a reaction vessel equipped with a stirrer, a reflux condenser, a dropping tank and a thermometer, 460 parts by mass of water, 4 parts by mass of Emulgen 950 (nonionic surfactant manufactured by Kao Corporation), 0.5 parts by mass of ammonium persulfate The mixture was charged, heated to 80 ° C., and purged with nitrogen. To this reaction vessel, 100 parts by weight of styrene, 260 parts by weight of methyl methacrylate, 75 parts by weight of 2-ethylhexyl acrylate, 14 parts by weight of 2-hydroxyethyl methacrylate, 730 parts by weight of water, 13 parts by weight of Emulgen 950, 13 parts by weight of Plex OT- A mixture consisting of 7 parts by mass of P, 2.4 parts by mass of ammonium persulfate, and 0.7 parts by mass of sodium hydrogen carbonate was emulsified and stirred at 6000 rotations of the homogenizer, and this emulsion mixture was kept in the reaction vessel at 80 ° C. from the dropping tank. It was allowed to flow for 5 hours. Subsequently, 5 parts by weight of styrene, 70 parts by weight of methyl methacrylate, 2 parts by weight of 2-ethylhexyl acrylate, 7 parts by weight of 2-hydroxyethyl methacrylate, 28 parts by weight of glycidyl methacrylate, 185 parts by weight of water, EMAMINE DT-210 (Nippon Yushi Co., Ltd. polyoxyethylene beef tallow alkylpropylamine) A mixture of 45 parts by mass of a 30% aqueous solution was emulsified and stirred at 6000 rotations of a homogenizer, and this emulsified mixture was kept in a reaction vessel at 80 ° C. for 30 minutes. After stirring for 1 hour, the mixture was cooled to room temperature to obtain a water-dispersible polymer F. The solid content was 30.0%, the particle system was 0.10 μm, the number average molecular weight was 350,000, and the epoxy equivalent was 2900 g / eq.

[Production of water-dispersed slurry paint]
[Examples 7 to 9]
In 400 parts by mass of water, 0.6 part by mass of an antifoaming agent (Troquid D777 manufactured by Troy Chemical Co., Ltd.), 0.6 parts by mass of a dispersion aid (Orotan 731K manufactured by Rohm and Haas), a wetting agent (Air Products 0.06 parts by mass of Sulfinol TMN6) manufactured by And Chemicals and 16.5 parts by mass of a thickener (RM8 manufactured by Rohm and Haas) were dispersed. Next, the glycidyl group-containing methacrylic resins of Examples 1 to 3 were pulverized with a Henschel mixer and then a pulverizer, passed through a 100 μm sieve, propylene glycol monomethyl ether and 1,3,6-hexanetricarboxylic acid. A small amount was added in the amount indicated in the above, and each was mixed with stirring. Subsequently, again, 0.6 parts by mass of antifoaming agent (Troquid D777 manufactured by Troy Chemical Co., Ltd.), 0.6 parts by mass of dispersion aid (Orotan 731K manufactured by Rohm and Haas Co., Ltd.), wetting agent (Air Products and Chemicals) 0.06 part by mass of Sulfinol TMN6) manufactured by the company and 16.5 parts by mass of a thickener (RM8 manufactured by Rohm and Haas) were mixed and dispersed. Subsequently, the same amount of the same powder resin, propylene glycol monomethyl ether and 1,3,6-hexanetricarboxylic acid were added in small portions and mixed with stirring. This was ground in a sand mill for 3.5 hours, filtered through a 50 μm filter, and 0.05 parts by weight of a leveling agent (Bic 345 manufactured by Big Chemie) was added.
The SPCC steel plate and glass plate (for transparency evaluation only) were electrostatically coated to a thickness of about 40 μm and baked at 120 ° C. or 140 ° C. for 20 minutes. The evaluation results of the coating film are shown in Table 1.

[Production of water-based paint]
[Examples 10 to 12]
To the 1000 parts by mass of the water-dispersible resins D to F of Examples 4 to 6, propylene glycol monomethyl ether, butyl cellosolve and 1,3,6-hexanetricarboxylic acid were added little by little with stirring.
The SPCC steel plate and glass plate (for transparency evaluation only) were electrostatically coated to a thickness of about 40 μm and baked at 120 ° C. or 140 ° C. for 20 minutes. The evaluation results of the coating film are shown in Table 1.

[Comparative Example 1]
16.8 parts by mass of glycidyl group-containing methacrylic resin B of Example 2, 312 parts by mass of dodecanedioic acid, 60 parts by mass of epoxy resin (AER-6071 manufactured by Asahi Kasei), 10 parts by mass of benzoin, 10 parts by mass of a leveling agent (Nicalite XK-81) After mixing with a Henschel mixer, it was melt-kneaded with a twin screw extruder set at 90 ° C., stretched with a roll, and cooled. 2 parts by mass of silica powder was added and pulverized with a Henschel mixer and then with a pulverizer to obtain a powder coating material through a 100 μm sieve.

In 400 parts by mass of water, 0.6 part by mass of an antifoaming agent (Troquid D777 manufactured by Troy Chemical Co., Ltd.), 0.6 parts by mass of a dispersion aid (Orotan 731K manufactured by Rohm and Haas), a wetting agent (Air Products 0.06 parts by mass of Sulfinol TMN6) manufactured by And Chemicals and 16.5 parts by mass of a thickener (RM8 manufactured by Rohm and Haas) were dispersed. Next, 94 parts by mass of the powder coating material was mixed with stirring. Subsequently, again, 0.6 parts by mass of antifoaming agent (Troquid D777 manufactured by Troy Chemical Co., Ltd.), 0.6 parts by mass of dispersion aid (Orotan 731K manufactured by Rohm and Haas Co., Ltd.), wetting agent (Air Products and Chemicals) 0.06 part by mass of Sulfinol TMN6) manufactured by the company and 16.5 parts by mass of a thickener (RM8 manufactured by Rohm and Haas) were mixed and dispersed. Subsequently, 94 parts by mass of the same powder coating material was stirred and mixed little by little. This was ground in a sand mill for 3.5 hours, filtered through a 50 μm filter, and 0.05 parts by weight of a leveling agent (Bic 345 manufactured by Big Chemie) was added.
The SPCC steel plate and glass plate (for transparency evaluation only) were electrostatically coated to a thickness of about 40 μm and baked at 120 ° C. or 140 ° C. for 20 minutes. The evaluation results of the coating film are shown in Table 1.

[Comparative Example 2]
44 parts by mass of 1,3,6-hexanetricarboxylic acid was added little by little to 1000 parts by mass of the water-dispersible resin D of Example 4.
The SPCC steel plate and glass plate (for transparency evaluation only) were electrostatically coated to a thickness of about 40 μm and baked at 120 ° C. or 140 ° C. for 20 minutes. The evaluation results of the coating film are shown in Table 1.

[Comparative Example 3]
To 1000 parts by mass of the water-dispersible resin D of Example 4, 240 parts by mass of propylene glycol monomethyl ether and 44 parts by mass of 1,3,6-hexanetricarboxylic acid were added little by little.
The SPCC steel plate and glass plate (for transparency evaluation only) were electrostatically coated to a thickness of about 40 μm and baked at 120 ° C. or 140 ° C. for 20 minutes. The evaluation results of the coating film are shown in Table 1.

[Create multilayer coating]
Example 13
An aqueous base paint (Superlac M260 Silver, manufactured by Nippon Paint Co., Ltd.) was applied onto the substrate with the undercoat and intermediate coat by air spray so that the dry film thickness was 20 μm. After a setting time of 3 minutes, the water-dispersed slurry paint (S1) of Example 7 was applied by electrostatic bell coating to a dry film thickness of 40 μm. The obtained substrate was put into a hot air drying oven and baked at 120 ° C. or 140 ° C. for 20 minutes to obtain a multilayer coating film. The evaluation results of the multilayer coating film are shown in Table 2.

Example 14
The color base paint B was applied on the substrate with the undercoat and intermediate coat by electrostatic coating so that the dry film thickness was 20 μm, and baked in a hot air drying oven set at 160 ° C. for 20 minutes. Next, the pearl base coating material C was coated thereon so as to have a dry film thickness of 20 μm by electrostatic coating. After a setting time of 3 minutes, the water-dispersed slurry paint (S2) of Example 8 was applied by electrostatic bell coating to a dry film thickness of 40 μm. The obtained substrate was put into a hot air drying oven and baked at 120 ° C. or 140 ° C. for 20 minutes to obtain a multilayer coating film. The evaluation results of the multilayer coating film are shown in Table 2.

Example 15
The color base paint B was applied by electrostatic coating so that the dry film thickness was 20 μm on the substrate with the undercoat and the intermediate coat. The pearl base coating material C was applied thereon with a setting time of 3 minutes so that the dry film thickness was 20 μm by electrostatic coating. After a setting time of 3 minutes, the water-dispersed slurry paint (S3) of Example 9 was applied by electrostatic bell coating so as to have a dry film thickness of 40 μm. The obtained substrate was put into a hot air drying oven and baked at 120 ° C. or 140 ° C. for 20 minutes to obtain a multilayer coating film. The evaluation results of the multilayer coating film are shown in Table 2.

Example 16
On the substrate on which the primer is applied, powder slurry intermediate coating (PS100 primer manufactured by Kansai Paint Co., Ltd.) is applied by electrostatic bell coating to a dry film thickness of 45 μm, and blow-off for 5 minutes with hot air at 60 ° C. Carried out. Next, an aqueous base paint (WT-500 Silver Metallic manufactured by Kansai Paint Co., Ltd.) was applied thereon so as to have a dry film thickness of 15 μm, and blow-off was performed with warm air at 80 ° C. for 3 minutes. Further thereon, the water-dispersed slurry paint (S2) of Example 8 was applied by electrostatic bell coating to a dry film thickness of 40 μm. The obtained substrate was first treated in a hot air drying oven set at 90 ° C. for 10 minutes, and then baked at 120 ° C. or 140 ° C. for 20 minutes to obtain a multilayer coating film. The evaluation results of the multilayer coating film are shown in Table 2.

Example 17
In Example 13, a multilayer coating film was obtained using the water-based paint (E1) of Example 10 instead of the water-dispersed slurry paint (S1). The evaluation results of the multilayer coating film are shown in Table 2.

Example 18
In Example 14, a multilayer coating film was obtained using the water-based paint (E2) of Example 11 instead of the water-dispersed slurry paint (S2). The evaluation results of the multilayer coating film are shown in Table 2.

Example 19
A multilayer coating film was obtained using the water-based paint (E3) of Example 12 instead of the water-dispersed slurry paint (S3) in Example 15. The evaluation results of the multilayer coating film are shown in Table 2.

Example 20
In Example 16, a multilayer coating film was obtained using the water-based paint (E2) of Example 14 instead of the water-dispersed slurry paint (S2). The evaluation results of the multilayer coating film are shown in Table 2.

[Comparative Example 4]
In Example 13, a multilayer coating film was obtained using the water-dispersed slurry paint (S4) of Comparative Example 1 instead of the water-dispersed slurry paint (S1). Table 3 shows the evaluation results of the multilayer coating film.

[Comparative Example 5]
In Example 14, a multilayer coating film was obtained using the water-based paint (E4) of Comparative Example 2 instead of the water-dispersed slurry paint (S2). Table 3 shows the evaluation results of the multilayer coating film.

[Comparative Example 6]
A multilayer coating film was obtained using the water-based paint (E5) of Comparative Example 3 instead of the water-dispersed slurry paint (S3) in Example 15. Table 3 shows the evaluation results of the multilayer coating film.

[Comparative Example 7]
In Example 16, a multilayer coating film was obtained using the water-based paint (E4) of Comparative Example 2 instead of the water-dispersed slurry paint (S2). Table 3 shows the evaluation results of the multilayer coating film.

  The present invention relates to a curable composition comprising at least an epoxy group-containing polymer, a water-soluble aliphatic tricarboxylic acid, an organic solvent, and water, and can be suitably used for water-based paints. Particularly, it is suitable for a curable composition used for an aqueous clear topcoat paint for automobiles.

Claims (11)

  It comprises at least a water-soluble and / or water-dispersible polymer (a) having two or more epoxy groups in the molecule, a curing agent (b), an organic solvent (c) and water (d), and a curing agent ( An aqueous curable composition characterized in that b) contains an aliphatic tricarboxylic acid.   The mass of the organic solvent (c) is 0.1 to 40 parts by mass when the sum of the mass of the polymer (a) and the curing agent (b) is 100 parts by mass. An aqueous curable composition. The curing agent (b) comprises 0.1 to 100% by mass of an aliphatic tricarboxylic acid represented by the following formula (1) and 0 to 99.9% by mass of another curing agent. The water-based curable composition as described in 2.

[Wherein p, r, and s are integers of 0 to 8, q is an integer of 1 to 9, and 1 ≦ p + q + r + s ≦ 9 and {r <s or (r = s and p ≦ q)}]   4. The water-based curable composition according to claim 3, wherein p + q + r + s = 3 in the above formula (1).   The aqueous curable composition according to claim 3 or 4, wherein p = 1, q = 2, and r = s = 0.   The organic solvent (c) is one or more selected from compounds having at least one ketone group, hydroxyl group, ether group, or ester group, and the proportion of the compound in the organic solvent is 0.1 to 100 mass. %. The aqueous curable composition according to claim 1, wherein the aqueous curable composition is%.   The water-based curable composition according to any one of claims 1 to 6, wherein the organic solvent (c) contains propylene glycol monomethyl ether.   The water-based curable composition according to any one of claims 1 to 7, wherein the polymer (a) is an epoxy group-containing acrylic resin polymer.   An aqueous paint for automobiles comprising the aqueous curing agent composition according to claim 1.   A water-based paint for clear topcoat, comprising the water-based curing agent composition according to any one of claims 1 to 8.   The coating film formed with the water-system coating material of Claim 9 or 10.