JP4886391B2 - Unsaturated bond-containing aqueous resin, curable aqueous resin composition, and aqueous coating composition - Google Patents

Description

  TECHNICAL FIELD The present invention relates to an unsaturated bond-containing aqueous resin useful as a curing agent and a film-forming aid, a curable aqueous resin composition containing the same, and an aqueous coating composition.

  In recent years, in the field of paints, attempts have been made to make it water-based in order to cope with environmental problems and to improve the working environment. In general, water-based paints are inadequate compared to solvent-based paints in terms of finish and film performance. Especially in the case of water-based paints that are dried at normal temperature or forcedly dried, the leveling properties of the paint film surface in the drying stage In addition, since the crosslinking reaction in the coating film is insufficient as compared with the case of the thermosetting type, it is difficult to bring the finish properties and physical properties of the coating film close to those of the solvent-based paint.

  Meanwhile, in the market, a one-pack type paint is desired from the viewpoint of versatility, and it is desired to develop a one-pack type water-based paint that has good finish and coating performance even under normal temperature drying or forced drying conditions.

  As an aqueous one-component paint that can be cured under normal temperature drying conditions, a paint containing an oxidation-curable resin is known.

  For example, Patent Document 1 discloses at least one selected from the group consisting of a dry oil fatty acid and / or a semidry oil fatty acid, an epoxy group-containing polymerizable unsaturated monomer, a sulfonic acid group, a sulfonate group, a phosphate group, and a phosphate group. A water-based resin composition characterized in that it is a fatty acid-modified acrylic resin having a polymerizable unsaturated monomer having a seed acid group as a copolymerization component, and the resin is finely dispersed in an aqueous medium. Yes.

  Patent Document 2 discloses an emulsion obtained by finely dispersing a monomer mixture containing a fatty acid-modified polymerizable unsaturated monomer and another polymerizable unsaturated monomer in an aqueous medium so that the average particle size is 500 nm or less. An aqueous coating composition containing an aqueous resin dispersion having an average particle diameter of 500 nm or less is described.

  According to the water-based coating compositions described in Patent Documents 1 and 2, a cured coating film can be formed that oxidizes and cures even at room temperature, and has a water resistance and a feeling of meatiness, and is familiar to metal surfaces. However, since the film is formed by fusion of resin particles, the film forming property is insufficient, and accordingly, the performance such as water resistance may not be sufficient.

  By the way, as a curing agent capable of low-temperature curability, Patent Document 3 describes a three-chain hydrophilic carbodiimide compound and an aqueous coating composition comprising the same. According to such a water-based paint composition, it can be cured at a relatively low temperature such as for automobile repair, and can form a coating film having excellent physical properties such as water resistance. If so, it may not be enough.

JP 2004-292895 A WO2004 / 073327 JP 2003-306476 A

  An object of the present invention is to provide an unsaturated bond-containing aqueous resin suitable for forming a coating film having excellent film forming properties and curability even under the above-mentioned conditions of room temperature drying and excellent in various physical properties such as water resistance. It is in providing the curable aqueous resin composition containing and the aqueous coating composition containing the curable aqueous resin composition.

As a result of intensive investigations on the above-mentioned problems, the present inventors have used carboxylic acid having an unsaturated bond, which is a dry oil fatty acid, a carbodiimide compound having an isocyanate group, and a polyalkylene glycol as raw materials, and an unsaturated having a carbodiimide group. The present inventors have found that the bond-containing aqueous resin has an effect of improving the film forming property and curability, and reached the present invention. That is, the present invention
1.
An unsaturated bond-containing aqueous resin having a carbodiimide group, starting from a carboxylic acid (a) having an unsaturated bond, which is a drying oil fatty acid, a carbodiimide compound (b) having an isocyanate group, and a polyalkylene glycol compound (c) , In addition, the aqueous binder resin is an aqueous monomer mixture containing an unsaturated fatty acid-modified polymerizable unsaturated monomer obtained by reacting an unsaturated fatty acid that is a drying oil fatty acid with an epoxy group-containing polymerizable unsaturated monomer. An aqueous coating composition containing an acrylic resin aqueous dispersion having a carboxyl group, which is obtained by finely dispersing an average particle size in a medium to be 500 nm or less and polymerizing the resulting monomer emulsion;
2.
A step of reacting an unsaturated bond-containing aqueous resin having a carbodiimide group with a carbodiimide compound (b) having an isocyanate group and a polyalkylene glycol compound (c), the reaction product obtained in the above step and a dry oil fatty acid. 2. The aqueous coating composition according to 1, which is produced by a step of reacting a carboxylic acid (a) having an unsaturated bond,
3.
A coating method for coating the surface to be coated with the aqueous coating composition according to item 1 or 2;
About.

(In the above formula, R ¹ , R ² , R ³ , R ⁴ , and R ⁵ may be the same or different and are a hydrogen atom or an organic group having 1 to 10 carbon atoms.)
4). Reacting the carbodiimide compound (b) having an isocyanate group with the polyalkylene glycol compound (c);
A method for producing an unsaturated bond-containing aqueous resin, comprising a step of reacting the reaction product obtained in the step with a carboxylic acid (a) having an unsaturated bond,
5. A curable aqueous resin composition comprising the resin according to any one of items 1 to 3,
6). The curable aqueous resin composition according to 5, further comprising an aqueous binder resin,
7). The curable aqueous resin composition according to 6, wherein the aqueous binder resin comprises an acrylic resin aqueous dispersion and / or a urethane resin aqueous dispersion,
8). Item 8. The curable aqueous resin composition according to Item 6 or 7, wherein the aqueous binder resin is derived from an unsaturated fatty acid.
9. An aqueous coating composition comprising the curable aqueous resin composition according to any one of items 5 to 8,
10. A coating method for applying the water-based coating composition according to 9 on a surface to be coated,
About.

  The unsaturated bond-containing aqueous resin of the present invention can be used as a curing agent or a film-forming aid, and the curable composition containing this has good film-forming properties even under conditions of room temperature drying. Thus, it is possible to form a coating film having excellent coating properties such as curability and water resistance. In addition, the unsaturated bond-containing aqueous resin can be dissolved or stably dispersed in water, so that the storage stability is good, and the compatibility with other aqueous resins is also excellent.

  The unsaturated bond-containing aqueous resin of the present invention is a resin made from a carboxylic acid (a) having an unsaturated bond, a carbodiimide compound (b) having an isocyanate group, and a polyalkylene glycol compound (c) as raw materials. Hereinafter, each component constituting the resin of the present invention will be described.

Carboxylic acid having an unsaturated bond (a)
In the present invention, as the carboxylic acid (a) having an unsaturated bond, a conventionally known compound can be used without particular limitation as long as it is a compound having one or more unsaturated bonds and one or more carboxylic acids in the molecule. An oxidatively curable compound is desirable. Specific examples of such carboxylic acid (a) include unsaturated fatty acids.

  Examples of unsaturated fatty acids include dry oil fatty acids, semi-dry oil fatty acids and the like. Specific examples of the dry fatty acids include fish oil fatty acids, dehydrated castor oil fatty acids, safflower oil fatty acids, linseed oil fatty acids, Soybean oil fatty acid, sesame oil fatty acid, poppy oil fatty acid, eno oil fatty acid, hemp seed oil fatty acid, grape kernel oil fatty acid, corn oil fatty acid, tall oil fatty acid, sunflower oil fatty acid, cotton seed oil fatty acid, walnut oil fatty acid, rubber seed oil fatty acid, hydienoic acid A fatty acid etc. are mentioned, These can be used individually or in combination of 2 or more types.

  Moreover, as said carboxylic acid (a), the carboxylic acid represented by a following formula may be sufficient.

(In the above formula, R ¹ , R ² , R ³ , R ⁴ , and R ⁵ may be the same or different and are a hydrogen atom or an organic group having 1 to 10 carbon atoms).

  Specific examples of the above formula include sorbic acid, 2,4-pentadienoic acid, trienic acid, 6-phenyl-2,4,6-heptatrienoic acid, retinoic acid (vitamin A), 5phenyl-2,4-pentadienoic acid And muconic acid, hexaene dicarboxylic acid and the like.

  According to the carboxylic acid according to the above formula, it has a constitutional unit called a conjugated double bond conjugated with the carbonyl moiety of the carboxyl group, so it is considered to have properties that combine (meth) acrylate and unsaturated fatty acid-like properties, The storage stability of the unsaturated group-containing aqueous resin of the present invention produced using this material as a raw material and the curability of the coating film formed using the resin can be made compatible.

Carbodiimide compound having an isocyanate group (b)
In the present invention, the carbodiimide compound (b) having an isocyanate group is not reacted with the carboxyl group of the carboxylic acid and the carbodiimide bond without causing the unsaturated bond-containing aqueous resin of the present invention to express a hydrophilic group such as a hydroxyl group. It is used to introduce a saturated bond into a molecular side chain, and is a compound that can be obtained by a condensation reaction of a diisocyanate compound.

  Moreover, the bond obtained by the carboxylic acid and carbodiimide bond also has an effect of improving adhesion without impairing the water resistance of the coating film formed by the curable aqueous resin composition of the present invention.

  When obtaining the carbodiimide compound (b) which has an isocyanate group by the condensation reaction of a diisocyanate compound, it does not specifically limit as a diisocyanate compound to be used, For example, 1, 5- naphthylene diisocyanate, 4, 4- diphenylmethane diisocyanate, 4, 4 -Diphenyldimethylmethane diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate Mixtures with isocyanates, aromatic diisocyanates such as tetramethylxylylene diisocyanate; aliphatic diisocyanates such as hexamethylene diisocyanate; cyclohexane-1,4-diisocyanate Over DOO, xylylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4-diisocyanate, can be mentioned alicyclic diisocyanates, and mixtures thereof such as methylcyclohexane diisocyanate.

  The condensation reaction can be performed using a carbodiimidization catalyst. The carbodiimidization catalyst is not particularly limited, and examples thereof include 1-phenyl-2-phospholene-1-oxide, 3-methyl-2-phospholene-1-oxide, 1-ethyl-2-phospholene-1-oxide, 3 Examples include -methyl-1-phenyl-2-phospholene-1-oxide, and phospholene oxides such as these 3-phospholene isomers.

  In the present invention, as the component (b), commercially available products such as “Carbodilite V-01” and “Carbodilite V-05” (trade name, Nisshinbo Co., Ltd.) can be used.

Polyalkylene glycol compound (c)
The polyalkylene glycol compound (c) is used to make the unsaturated bond-containing aqueous resin of the present invention soluble or dispersible in water, and is a compound having a polyalkylene unit and a hydroxyl group in the molecule. Thus, for example, a compound represented by the following formula can be used.
R ⁶ O— (R ⁷ O) _n —H
(Wherein R ⁶ is a hydrogen atom, an alkyl group or an aryl group, R ⁷ is an alkylene group having 2 to 4 carbon atoms, and n is 2 to 60).

  Specific examples of such compounds include polyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol; alkoxy polyalkylenes such as methoxypolyethylene glycol, ethoxypolyethylene glycol, ethoxypolypropylene glycol, and ethoxypolybutylene glycol. Examples of glycols include polyoxyalkylene alkyl phenyl ethers such as polyoxyethylene nonyl phenyl ether and polyoxyethylene octyl phenyl ether. Particularly, when alkoxy polyalkylene glycol is used, synthesis is easy and suitable.

The reaction of the components (a), (b) and (c) can be carried out all at once or sequentially. In this case, the proportion of use of (a), (b) and (c) is, for example, ( the hydroxyl group in (c) is in the range of 0.5 to 1.5 moles, in particular 0.8 to 1.2 moles per mole of isocyanate groups in b),
It is suitable that the carboxyl group in (a) is in the range of 0.1 to 1.5 mol, particularly 0.2 to 1.2 mol, relative to 1 mol of the carbodiimide group in (b). ing.

The unsaturated bond-containing aqueous resin of the present invention is a step of reacting a carbodiimide compound (b) having an isocyanate group with a polyalkylene glycol compound (c) from the viewpoint of production stability,
Reacting the reaction product obtained in the step with a carboxylic acid (a) having an unsaturated bond,
It is desirable to be manufactured by.

  In the step of reacting the carbodiimide compound (b) having an isocyanate group and the polyalkylene glycol compound (c), the reaction is usually carried out at a temperature of 40 to 180 ° C, preferably 60 to 130 ° C.

  In order to promote this reaction, amine catalysts such as triethylamine, N-ethylmorpholine, and triethylenediamine used in ordinary urethanization reactions and tin catalysts such as dibutyltin dilaurate and dioctyltin dilaurate are used as necessary. It may be used.

  In the step of reacting the reaction product obtained in the above step with the unsaturated carboxylic acid (a), the reaction is usually performed at a temperature of 60 to 120 ° C, preferably 70 to 100 ° C.

  The unsaturated bond-containing aqueous resin of the present invention can be dissolved or dispersed in water by a conventional method after being diluted with a hydrophilic organic solvent as necessary.

  Specific examples of the hydrophilic organic solvent used for such purposes include alcohol organic solvents such as methanol, ethanol, isopropanol, n-butanol and isobutanol; ether organic solvents such as dioxane and tetrahydrofuran; ethylene glycol monomethyl Ethylene glycol ether organic solvents such as ether, ethylene glycol monoethyl ether, ethylene glycol mono n-propyl ether, ethylene glycol monoisopropyl ether, ethylene glycol mono n-butyl ether, ethylene glycol monoisobutyl ether, ethylene glycol mono tert-butyl ether; Diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono n-propyl ether Diethylene glycol ether-based organic solvents such as diethylene glycol monoisopropyl ether, diethylene glycol mono n-butyl ether, diethylene glycol monoisobutyl ether, diethylene glycol mono tert-butyl ether; propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono n-propyl ether, Propylene glycol ether organic solvents such as propylene glycol monoisopropyl ether; Dipropylene glycol ether organics such as dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono n-propyl ether, dipropylene glycol monoisopropyl ether Melting ; Ethyl acetate, butyl acetate, isobutyl acetate, 3-ester organic solvents such as methoxybutyl acetate and the like, which can be used either alone or in combination of two or more.

  Since the unsaturated bond-containing aqueous resin of the present invention can be dissolved or dispersed in water, it can be applied to aqueous curable compositions in the fields of paints, inks, adhesives and the like.

  In the present specification, the water-soluble product in a state dissolved in water is a case where the average particle size of the water-soluble product is 10 nm or less, and the water dispersion in a state dispersed in water is an aqueous dispersion. The average particle diameter is greater than 10 nm.

  In the present specification, the average particle size is measured by diluting the sample with deionized water with “SALD-3100” (trade name, manufactured by Shimadzu Corporation, laser diffraction particle size distribution analyzer) to 20 ° C. This is the value when

Curable aqueous resin composition The curable aqueous resin composition of the present invention can include an aqueous binder resin in addition to the unsaturated bond-containing aqueous resin. As such an aqueous binder resin, an aqueous resin that can be dissolved or dispersed in water can be used, and the type of the resin is not particularly limited. Specific examples include acrylic resins, polyolefin resins, silicon resins, polyurethane resins, epoxy resins, phenol resins, polyester resins, alkyd resins, polycarbonate resins, and the like. Can be used alone or in combination of two or more. These resins may be modified like, for example, urethane-modified acrylic resins, or may be graft-polymerized.

  In the curable aqueous resin composition of the present invention, the proportion of the unsaturated group-containing aqueous resin and the aqueous binder resin used is 1 to 40 unsaturated group-containing aqueous resins per 100 parts by mass of the aqueous binder resin solid content. When it is contained in a proportion of 5 parts by mass, preferably 5 to 30 parts by mass, it is desirable from the viewpoints of storage stability of the curable aqueous resin composition, film-forming property of the formed coating film, and water resistance.

  The aqueous binder resin may be a resin having an anionic group, for example, a carboxyl group as a hydrophilic group from the viewpoint of solubility or dispersibility in water. In this case, the resin is neutralized. Examples of the neutralizing agent that can be used at that time include amines such as methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, dimethylaminoethanol, 2-methyl-2-amino-1-propanol, and the like. And ammonia and the like can be exemplified, and these can be used alone or in combination of two or more.

  When the aqueous binder resin has a carboxyl group in the molecule, it can act as a hydrophilic group for water during storage, and can impart water dispersibility or water solubility to the aqueous binder resin. When a carbodiimide group remains in the unsaturated bond-containing aqueous resin at the time of film formation, it can act as a cross-linking functional group, which can contribute to improvement of coating properties such as water resistance.

  Further, if the aqueous binder resin is derived from an unsaturated fatty acid, the compatibility with the unsaturated bond-containing aqueous resin of the present invention is improved, and the curability and film-forming property are remarkably improved and formed. It becomes possible to give an oxidative curability and a feeling of flesh to the coated film.

  The aqueous binder resin preferably contains an acrylic resin aqueous dispersion and / or a urethane resin aqueous dispersion as a part of its components from the viewpoint of the weather resistance of the formed coating film.

  Examples of the acrylic resin aqueous dispersion include those obtained by dispersing a copolymer of a polymerizable unsaturated monomer in water. Examples of the polymerizable unsaturated monomer include methyl (meth) acrylate and ethyl (meth). Acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl ( Linear or branched alkyl (meth) acrylates such as meth) acrylate; alicyclic alkyl (meth) acrylates such as cyclohexyl (meth) acrylate and isobornyl (meth) acrylate; aralkyl (meth) acrylates such as benzyl (meth) acrylate G; alkoxyalkyl (meth) acrylate such as 2-methoxyethyl (meth) acrylate and 2-ethoxyethyl (meth) acrylate; perfluoroalkyl (meth) acrylate; N such as N, N-diethylaminoethyl (meth) acrylate , N-dialkylaminoalkyl (meth) acrylate; (meth) acrylamide; (meth) acrylonitrile; vinyl ester compounds such as vinyl acetate and vinyl propionate; vinyl aromatic compounds such as styrene and α-methylstyrene; allyl (meth) Acrylate, ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, trimethylol group Lopantri (meth) acrylate, 1,4-butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tetra (Meth) acrylate, glycerol di (meth) acrylate, 1,1,1-trishydroxymethylethane di (meth) acrylate, 1,1,1-trishydroxymethylethanetri (meth) acrylate, 1,1,1- A polyvinyl compound having at least two polymerizable unsaturated groups in one molecule, such as trishydroxymethylpropane tri (meth) acrylate, triallyl isocyanurate, diallyl terephthalate, divinylbenzene; Rate, hydroxyalkyl (meth) acrylates such as 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate and hydroxybutyl (meth) acrylate, allyl alcohol, and ε- of the above hydroxyalkyl (meth) acrylate Denatured caprolactone, hydroxyl group-containing polymerizable unsaturated monomer such as polyoxyethylene chain-containing (meth) acrylate having a hydroxyl group at the molecular end; carboxyl group such as (meth) acrylic acid, maleic acid, crotonic acid, β-carboxyethyl acrylate, etc. Containing polymerizable unsaturated monomer: (meth) acrolein, formylstyrene, vinyl alkyl ketone having 4 to 7 carbon atoms (for example, vinyl methyl ketone, vinyl ethyl ketone, vinyl butyl ketone, etc.), acetoacetoxyethyl (meta Carbonyl group-containing polymerizable unsaturated monomers such as acrylate, acetoacetoxyallyl ester, diacetone (meth) acrylamide; glycidyl (meth) acrylate, β-methylglycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate , 3,4-epoxycyclohexylethyl (meth) acrylate, 3,4-epoxycyclohexylpropyl (meth) acrylate, epoxy group-containing polymerizable unsaturated monomers such as allyl glycidyl ether; isocyanate ethyl (meth) acrylate, m-iso Isocyanate group-containing polymerizable unsaturated monomers such as propenyl-α, α-dimethylbenzyl isocyanate; vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloyloxypropylate An alkoxysilyl group-containing polymerizable unsaturated monomer such as limethoxysilane, γ-methacryloyloxypropyltriethoxysilane; an epoxy group-containing polymerizable unsaturated monomer or a reaction product of a hydroxyl group-containing polymerizable unsaturated monomer and an unsaturated fatty acid; Examples thereof include oxidatively curable group-containing polymerizable unsaturated monomers such as dicyclopentenyloxyethyl (meth) acrylate, dicyclopentenyloxypropyl (meth) acrylate, dicyclopentenyl (meth) acrylate, and the like. Two or more types can be used in combination.

  The method for polymerizing the monomer is not particularly limited. For example, according to a general emulsion polymerization method, an acrylic resin aqueous dispersion can be easily produced by (co) polymerizing the monomer in the presence of an emulsifier. can do.

  As the emulsifier used in the production of the acrylic resin, known emulsifiers can be used. Examples of applicable emulsifiers include anionic emulsifiers, nonionic emulsifiers and amphoteric emulsifiers. Can do.

  Examples of the anionic emulsifier include diammonium dodecyl diphenyl ether disulfonate, sodium dodecyl diphenyl ether disulfonate, calcium dodecyl diphenyl ether disulfonate, alkyl diphenyl ether disulfonate such as sodium alkyl diphenyl ether disulfonate; sodium dodecyl benzene sulfonate, dodecyl benzene sulfonic acid Alkyl benzene sulfonates such as ammonium; alkyl sulfates such as sodium lauryl sulfate and ammonium lauryl sulfate; aliphatic carboxylates such as fatty acid sodium and potassium oleate; sulfate salts containing polyoxyalkylene units (for example, polyoxyethylene alkyl) Sodium ether sulfate, polyoxyethylene alkyl ether sulfate Polyoxyethylene alkyl ether sulfates such as ammonium; polyoxyethylene alkylphenyl ether sulfate sodium, polyoxyethylene alkylphenyl ether sulfates such as ammonium polyoxyethylene alkylphenyl ether sulfate; polyoxyethylene polycyclic sodium phenyl ether sulfate; Polyoxyethylene polycyclic phenyl ether sulfates such as polyoxyethylene polycyclic phenyl ether ammonium sulfate); Naphthalene sulfonic acid formalin condensate such as sodium naphthalene sulfonic acid formalin condensate salt; Sodium dialkyl sulfosuccinate, monoalkyl succinate Alkyl succinate sulfonates such as disodium sulfonate, and the like. It may be used in combination of two or more.

  Examples of nonionic emulsifiers include polyoxyalkylene unit-containing ether compounds (for example, polyoxyalkylene alkyl ether compounds such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene tridecyl ether, polyoxyethylene oleyl ether). Polyoxyalkylene alkyl phenyl ether compounds such as polyoxyethylene octyl phenyl ether and polyoxyethylene nonyl phenyl ether; polyoxyalkylene polycyclic phenyl ether compounds such as polyoxyethylene polycyclic phenyl ether); polyoxyethylene monolaurate Polyoxyalkylene alkyl ester compounds such as polyoxyethylene monostearate and polyoxyethylene monooleate; Polyoxyalkylene alkylamine compounds such as reoxyethylene alkylamine; sorbitan compounds such as sorbitan monolaurate, sorbitan monostearate, sorbitan trioleate, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monooleate, etc. These can be used alone or in combination of two or more.

  Examples of amphoteric emulsifiers include dimethylalkyl betaines, dimethylalkyl lauryl betaines, and alkyl glycines.

  As the emulsifier, a reactive emulsifier containing both a polymerizable unsaturated group and an anionic group or nonionic group in the molecule can also be used.

  The usage-amount of the said emulsifier is 0.5-6 mass% normally on the basis of the total mass of a polymerizable unsaturated monomer, Preferably it can exist in the range of 1-4 mass%.

  In the present invention, when the acrylic resin aqueous dispersion is derived from an unsaturated fatty acid, the method for introducing the unsaturated fatty acid into the acrylic resin aqueous dispersion is not particularly limited, but the production stability, Since it is possible to reduce the amount of organic solvent in the composition finally obtained, unsaturated fatty acid-modified polymerizable unsaturated monomer obtained by reacting unsaturated fatty acid and epoxy group-containing polymerizable unsaturated monomer And other monomeric unsaturated monomer-containing monomer mixtures having an average particle diameter of 500 nm or less in an aqueous medium, an average particle diameter of 500 nm or less in an aqueous medium, preferably 80 to 400 nm, more preferably 100 to 300 nm. It is desirable that the dispersion be obtained by a method obtained by finely dispersing to a degree and polymerizing the resulting monomer emulsion. .

  In the present specification, examples of the aqueous medium include water or a water-organic solvent mixed solution obtained by dissolving water or an organic solvent such as a hydrophilic organic solvent.

  The fine dispersion of the mixture in an aqueous medium can be usually performed using a disperser having a high energy shearing ability. Examples of the disperser that can be used in this case include a high-pressure emulsifier, an ultrasonic emulsifier, a high-pressure colloid mill, and a high-pressure homogenizer. These dispersers can usually be operated under a high pressure of about 10 to 1000 MPa, preferably about 50 to 300 MPa. In addition, the monomer mixture may be pre-emulsified with a disper or the like in advance before being dispersed by the machine. Polymerization of the resulting emulsion is carried out by, for example, charging the entire amount of the finely dispersed emulsion into a reactor equipped with a stirrer, adding a polymerization initiator, and heating with stirring according to the miniemulsion polymerization method. Can do.

  Moreover, the said curable aqueous resin composition can contain a urethane resin water dispersion as a binder component from points, such as the toughness of a formed coating film. As the urethane resin aqueous dispersion, conventionally known ones can be used without limitation, and examples thereof include an urethane resin aqueous dispersion derived from a urethane prepolymer obtained by reacting a polyisocyanate, a polyol and a carboxyl group-containing diol. it can.

  Examples of polyisocyanates include aliphatic diisocyanate compounds such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, dimer acid diisocyanate, and lysine diisocyanate; burette-type adducts and isocyanurate ring adducts of these diisocyanate compounds; isophorone diisocyanate, 4,4 '-Methylenebis (cyclohexyl isocyanate), methylcyclohexane-2,4- (or-2,6-) diisocyanate, 1,3- (or 1,4-) di (isocyanatomethyl) cyclohexane, 1,4-cyclohexane diisocyanate Alicyclic diisocyanate compounds such as 1,3-cyclopentane diisocyanate and 1,2-cyclohexane diisocyanate; Turret type adduct, isocyanurate ring adduct; xylylene diisocyanate, metaxylylene diisocyanate, tetramethyl xylylene diisocyanate, tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, 1,4-naphthalene diisocyanate 4,4'-toluidine diisocyanate, 4,4'-diphenyl ether isocyanate, (m- or p-) phenylene diisocyanate, 4,4'-biphenylene diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, Aromatic diisocyanate compounds such as bis (4-isocyanatophenyl) sulfone and isopropylidenebis (4-phenylisocyanate); these diisocyanates Biuret-type adducts of isotonic compounds, isocyanurate ring adducts; triphenylmethane-4,4 ′, 4 ″ -triisocyanate, 1,3,5-triisocyanatobenzene, 2,4,6-tri Polyisocyanate compounds having three or more isocyanate groups in one molecule such as isocyanatotoluene and 4,4'-dimethyldiphenylmethane-2,2 ', 5,5'-tetraisocyanate; burettes of these polyisocyanate compounds Type adducts, isocyanurate cycloadducts; ethylene glycol, propylene glycol, 1,4-butylene glycol, dimethylolpropionic acid, polyalkylene glycol, trimethylolpropane, hexanetriol and other isocyanate groups in excess of hydroxyl groups At a ratio of polyiso Urethane adduct obtained by reacting a Aneto compound; these urethane adducts of views - let type adducts can include an isocyanurate ring adducts.

  Examples of the polyol include those having a weight average molecular weight in the range of 200 to 10,000, such as polyethylene glycol, polypropylene glycol, polyethylene-propylene (block or random) glycol, polytetramethylene ether glycol, polyhexamethylene ether glycol, poly Polyether polyols such as octamethylene ether glycol; dicarboxylic acids (adipic acid, succinic acid, sebacic acid, glutaric acid, maleic acid, fumaric acid, phthalic acid, etc.) and glycols (ethylene glycol, propylene glycol, 1,4-butanediol) , 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, bishydroxymethylcyclohexane, etc.) For example, polyester polyols such as polyethylene adipate, polybutylene adipate, polyhexamethylene adipate, polyneopentyl adipate, poly-3-methylpentyl adipate, polyethylene / butylene adipate, polyneopentyl / hexyl adipate; polycaprolactone polyol, poly-3- Methyl valerolactone polyol; polycarbonate polyol; ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,4-butanediol, tetramethylene glycol, hexamethylene glycol, decamethylene glycol, octanediol, tricyclodecandi Such as methylol, hydrogenated bisphenol A, cyclohexanedimethanol, 1,6 hexanediol, etc. Molecular weight glycols; and the like, may be used alone or in combination.

  Moreover, when the urethane resin aqueous dispersion is derived from an unsaturated fatty acid, the urethane resin aqueous dispersion can be produced by including a fatty acid ester as a part of the component of the polyol.

  The fatty acid ester used for such a purpose contains two or more hydroxyl groups in one molecule and usually has a structural unit derived from a fatty acid via an ester bond, and has a low molecular weight to a high molecular weight. There are no particular limitations on the material, and it can be appropriately selected according to the use of the aqueous resin dispersion obtained by the method of the present invention.

  As such fatty acid ester, glycerol mono fatty acid ester can be used first. Examples of the glycerin monofatty acid ester include glycerin monolaurate, glycerin monooleate, and glycerin monostearate, and further esterification reaction between glycerin and a fatty acid having 10 or more carbon atoms, and transesterification reaction between fats and oils and glycerin. And the like obtained by the above. Moreover, the reaction product of a glycidol and a fatty acid may be sufficient.

  Examples of the carboxyl group-containing diol include dimethylolacetic acid, dimethylolpropionic acid, and dimethylolbutyric acid.

  The urethane prepolymer can be neutralized with a neutralizing agent. The neutralizing agent is not particularly limited, and examples thereof include ammonia, ethylamine, diethylamine, triethylamine, propylamine, dipropylamine, monoethanolamine, diethanolamine, butylamine, ethylenediamine, methylethanolamine, dimethylethanolamine, dimethylpropanolamine and the like. These amine compounds are mentioned.

  Moreover, the urethane prepolymer may be chain-extended as necessary.

  The chain extender used in the chain extension reaction is a compound having at least two active hydrogen groups, such as 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentane, diol, and ethylene. Alcohols such as glycol, neopentyl glycol, trimethylolpropane, glycerin, cyclohexanedimethanol; polyamines such as ethylenediamine, propylenediamine, xylylenediamine, triethylamine, diethylenetriamine, dipropylenetriamine, triethylenetetramine, monoethanolamine, hydroxyethyl Alkanolamines such as aminopropylamine, diethanolamine and N-methylethanolamine; hydrazine compounds such as hydrazine and hydrazine hydrate; water and the like can be used.

  Moreover, the said curable aqueous resin composition can also contain a metal dryer as a catalyst for promoting oxidation hardening. Examples of such metal dryers include salts of at least one metal selected from the group consisting of aluminum, calcium, cerium, cobalt, iron, lithium, magnesium, manganese, zinc, and zirconium with an acid. Examples include capric acid, caprylic acid, isodecanoic acid, linolenic acid, naphthenic acid, neodecanoic acid, octenoic acid, oleic acid, palmitic acid, resin acid, ricinoleic acid, soybean oil fatty acid, stearic acid, tall oil fatty acid, etc. It is done.

  As a compounding quantity of the said metal dryer, it is in the range of 0.001-10 mass%, especially 0.02-5 mass% on the basis of the sum total of the resin solid content contained in curable aqueous resin composition. It is desirable.

Aqueous coating composition The aqueous coating composition of the present invention comprises the curable aqueous resin composition described above.

  When the curable aqueous resin composition is applied to an aqueous coating composition, it can be applied to either a clear coating or an enamel coating.

  When applied as an enamel paint, conventionally known color pigments, glitter pigments, extender pigments, rust preventive pigments, and the like can be blended as the pigment component.

  In the above aqueous coating composition, in addition to the above components, pigment dispersant, surfactant, surface conditioner, plasticizer, anti-settling agent, antistatic agent, antibacterial agent, fragrance, ultraviolet absorber, ultraviolet stabilizer, curing Catalysts, dispersants, antifoaming agents, thickeners, film-forming aids, antiseptics, antifungal agents, antifreezing agents, pH adjusters, flash last deterrents, aldehyde scavengers, lamellar viscosity minerals, powders or fine particles Additives such as activated carbon and photocatalytic titanium oxide can be appropriately selected and combined.

  The present invention is a coating method for coating the above-mentioned aqueous coating composition on a surface to be coated.

  Examples of coated surfaces include, for example, metal surfaces such as iron and aluminum; organic material surfaces such as plastics; concrete surfaces, mortar surfaces, slate plates, PC plates, ALC plates, cemented calcium silicate plates, wood, stones, and other inorganic substrates. Material surface; Acrylic resin-based, acrylic urethane resin-based, polyurethane resin-based, fluororesin-based, silicon acrylic resin-based, vinyl acetate resin-based, epoxy resin-based coating surface provided on these substrates it can.

  The aqueous coating composition can be applied using a known device such as an air spray, an airless spray, a roller, a ricin gun, a universal gun, a brush, or electrostatic coating. Moreover, as a drying method, any of heat drying, forced drying, and normal temperature drying may be sufficient.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to only these examples. In the following examples, “part” and “%” mean “part by mass” and “% by mass”, respectively.

Production Example 1 of Unsaturated Group-Containing Resin Water Dispersion
To a four-necked flask equipped with a stirrer, a condenser tube and a nitrogen inlet tube, 1024.4 parts of polycarbodiimide “Carbodilite V-05” (Note 1) and one-end methoxy-modified polyethylene glycol “Uniox M-400” (Note) 2) was charged and reacted at 80 ° C. for 3 hours until the isocyanate group substantially disappeared. Thereafter, 980 parts of linseed oil fatty acid was added and further reacted at 80 ° C. for 4 hours, and then 701 parts of propylene glycol monomethyl ether was added and stirred until uniform. To this, 3505 parts of deionized water was added over 1 hour to obtain a translucent unsaturated group-containing resin water dispersion (A-1) having a solid content of 40.3%. The theoretical carbodiimide equivalent of the unsaturated group-containing resin in the unsaturated group-containing resin aqueous dispersion (A-1) is 7010.
(Note 1) “Carbodilite V-05”: trade name, manufactured by Nisshinbo Co., Ltd., isocyanate-terminated polycarbodiimide, isocyanate amount 8.2%, carbodiimide equivalent 262,
(Note 2) “Uniox M-400”: trade name, manufactured by NOF Corporation, one-end methoxy-modified polyethylene glycol, molecular weight 400.

Example 2
A four-necked flask equipped with a stirrer, a condenser tube, and a nitrogen inlet tube was charged with 1024.4 parts of polycarbodiimide “Carbodilite V-05” (Note 1) and one-end methoxy-modified polyethylene glycol “Uniox M400” (Note 2). 800 parts were charged and reacted at 80 ° C. for 3 hours until the isocyanate group substantially disappeared. Thereafter, 392 parts of sorbic acid was added and further reacted at 80 ° C. for 4 hours, then diluted with 554 parts of propylene glycol monomethyl ether and stirred until uniform. To this, 2770 parts of deionized water was added over 1 hour to obtain a translucent unsaturated group-containing resin water dispersion (A-2) having a solid content of 40.2%. The theoretical carbodiimide equivalent of the unsaturated group-containing resin in the unsaturated group-containing resin aqueous dispersion (A-2) is 5540.

Example 3
A four-necked flask equipped with a stirrer, a condenser tube, and a nitrogen introduction tube was charged with 1024.4 parts of polycarbodiimide “Carbodilite V-05” (Note 1), and one-end methoxy-modified polyethylene glycol “Uniox M-400” (Note 2). ) Was allowed to react at 80 ° C. for 3 hours until the isocyanate group substantially disappeared. Then, after adding 336 parts of sorbic acid and making it react at 80 degreeC for 4 hours, it diluted with 554 parts of propylene glycol monomethyl ether, and stirred until it became uniform. To this, 2770 parts of deionized water was added over 1 hour to obtain a translucent unsaturated group-containing resin water dispersion (A-3) having a solid content of 40.3%. The theoretical carbodiimide equivalent of the unsaturated group-containing resin in the unsaturated group-containing resin aqueous dispersion (A-3) is 2400.

Example 4
A four-necked flask equipped with a stirrer, a condenser tube, and a nitrogen inlet tube was charged with 1024.4 parts of polycarbodiimide “Carbodilite V-05” (Note 1), uni-terminal methoxy-modified polyethylene glycol “Uniox M-550” (Note 3) 1100 parts) and reacted at 90 ° C. for 3 hours until the isocyanate group substantially disappeared. Then, after adding 490 parts of linseed oil fatty acid and further reacting at 80 ° C. for 4 hours, 3194 parts of deionized water was added, and a translucent unsaturated group-containing resin water dispersion (A-4) having a solid content of 45% was added. Got. The theoretical carbodiimide equivalent of the unsaturated group-containing resin in the unsaturated group-containing resin aqueous dispersion (A-4) is 1210.
(Note 3) “Uniox M-550”: trade name, manufactured by NOF Corporation, one-end methoxy-modified polyethylene glycol, molecular weight 550.

Comparative Example 1 for Production of Resin Water Dispersion Without Unsaturated Group
A four-necked flask equipped with a stirrer, a condenser tube, and a nitrogen introduction tube was charged with 1024.4 parts of polycarbodiimide “Carbodilite V-05” (Note 1), and one-end methoxy-modified polyethylene glycol “Uniox M-400” (Note 2). ) 800 parts were charged and reacted at 80 ° C. for 3 hours until the isocyanate group disappeared. Thereafter, the mixture was diluted with 540 parts of propylene glycol monomethyl ether and stirred until uniform. To this, 2196.6 parts of deionized water was added over 1 hour to obtain a translucent resin water dispersion (A-5) having a solid content of 40.0%. The theoretical carbodiimide equivalent of the resin in the resin aqueous dispersion (A-5) is 466.

Production of unsaturated fatty acid-modified acrylic resin aqueous dispersion Production Example 1
The following components are put into a glass beaker and stirred at 2000 rpm for 15 minutes with a disper to produce a pre-emulsified liquid. Then, the pre-emulsified liquid is subjected to high-pressure treatment at 100 MPa in a high-pressure emulsifier that applies high-pressure energy to collide the fluids. As a result, a monomer emulsion having an average particle diameter of 190 nm was obtained.
Monomer emulsion composition Fatty acid-modified monomer (Note 4) 30 parts n-butyl methacrylate 25 parts i-butyl methacrylate 27 parts 2-ethylhexyl methacrylate 17 parts methacrylic acid 1 part "Newcol 707SF" (Note 5) 10 parts deionized 85 parts of water The monomer emulsion was then transferred to a flask and diluted with deionized water to a solid content of 45%. Thereafter, the temperature is raised to 85 ° C., an aqueous initiator solution in which 2 parts of “VA-086” (Note 6) is dissolved in 10 parts of deionized water is added to the flask, and the reaction is continued for 3 hours while maintaining the temperature. -086 "(Note 6) An aqueous initiator solution in which 0.5 part was dissolved in 10 parts deionized water was added to the flask, reacted for 1 hour while maintaining the temperature, cooled to 40 ° C, and dimethylamino The pH was adjusted to 8.0 with ethanol to obtain an acrylic resin dispersion (B-1) having a solid content of 40% and an average particle size of 185 nm.
(Note 4) Fatty acid-modified monomer: Reaction obtained by charging 280 parts of safflower oil fatty acid and 142 parts of glycidyl methacrylate in a four-necked flask equipped with a stirrer, a cooling tube and a nitrogen introduction tube, and reacting at 140 ° C. for 5 hours. Product,
(Note 5) “Newcol 707SF”: trade name, manufactured by Nippon Emulsifier Co., Ltd., an anionic emulsifier having a polyoxyethylene chain, 30% active ingredient,
(Note 6) “VA-086”: trade name, 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) -propionamide] manufactured by Wako Pure Chemical Industries, Ltd.

Production and Production Example 2 of Acrylic Resin Water Dispersion Unmodified with Unsaturated Fatty Acid
28.5 parts of deionized water and 0.1 part of “Newcol 707SF” were added to a 4-liter flask having a volume of 2 liters, and maintained at 85 ° C. after nitrogen substitution. To this, 3% of a pre-emulsion obtained by emulsifying the following composition and 25% of 10.5 parts of an initiator aqueous solution prepared by dissolving 0.5 part of ammonium persulfate in 10 parts of deionized water, 20 minutes after the addition, the remaining pre-emulsion and the remaining aqueous ammonium persulfate solution were added dropwise over 4 hours. After completion of dropping, this was further maintained at 85 ° C. for 2 hours, and then cooled to 40-60 ° C. Next, the pH was adjusted to 7 with aqueous ammonia to obtain an acrylic resin dispersion (B-2) having a solid content of 55% and an average particle size of 180 nm.
Pre-emulsion composition Deionized water 36.8 parts Styrene 15 parts Methyl methacrylate 40 parts n-Butyl acrylate 25 parts 2-Ethylhexyl acrylate 2 parts Hydroxyethyl acrylate 2 parts Methacrylic acid 3 parts "Newcol 707SF" 6.6 parts.

Production of unsaturated fatty acid-modified urethane resin aqueous dispersion Production Example 3
In a four-necked flask equipped with a stirrer, a condenser tube and a nitrogen inlet tube, “Emulsy MU” (Note 7) 354 parts, “Placcel 205” (Note 8) 550 parts, isophorone diisocyanate 892 parts, N-methylpyrrolidone 481.5 Parts were prepared and reacted at 80 ° C. for 4 hours to obtain a urethane prepolymer. After cooling to 50 ° C. or lower, 802.5 parts of N-methylpyrrolidone was added and stirred until uniform, and then 80.8 parts of triethylamine was added for neutralization. Subsequently, 1790 parts of deionized water was added over 0.5 hours to obtain an aqueous dispersion of a prepolymer. To this aqueous dispersion, 601.1 parts of a 10% ethylenediamine aqueous solution was added over 0.5 hours, and the chain extension reaction of the prepolymer was aged at 50 ° C. for 2 hours to obtain an average particle size of 91 nm and a non-volatile content of 35.1%. An unsaturated fatty acid-modified urethane resin aqueous dispersion (B-3) was obtained.
(Note 7) “Emulsy MU” manufactured by Riken Vitamin Co., Ltd., distilled mono fatty acid glyceride (glycerin mono fatty acid ester content 93% or more, iodine value 108-120),
(Note 8) “Placcel 205”: trade name, manufactured by Daicel Chemical Industries, polycaprolactone diol.

Examples 5-11 and Comparative Examples 2-3
An aqueous resin composition was obtained according to the composition shown in Table 1 below. Each aqueous resin composition was subjected to the following test and evaluated. The results are shown in Table 1.

(Note 9) “DICnate 1000W”: manufactured by Dainippon Ink Co., Ltd., trade name, metal dryer, Co content 3.6%,
(Note 10) “Texanol”: manufactured by Eastman Chemical Co., trade name, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, film-forming aid,
(* 1) Curability Each sample sample was coated on a polypropylene plate with an applicator so as to have a dry film thickness of 40 μm, cured at 25 ° C. for 10 days to create a film, cut into a size of 4 × 4 cm, A test piece was obtained. The obtained test piece was immersed in acetone at room temperature for 24 hours. The solvent extraction residue was calculated from the coating film mass before and after extraction as follows.
Solvent extraction residue (%) = (Mass of membrane after extraction / Mass of membrane before extraction) × 100 (%)
(* 2) Compatibility Each sample sample was coated on a glass plate with an applicator so as to have a dry film thickness of 40 μm, cured at 25 ° C. for 10 days, and visually evaluated as a test plate according to the following evaluation criteria.
○: Transparent, Δ: Blueing, ×: Translucent.
(* 3) Water resistance Each sample sample was coated on a tin plate with an applicator so that the dry film thickness was 40 μm, and was cured at 25 ° C. for 10 days to form a test plate. The degree of whitening was visually evaluated.
◯: No change, Δ: Slightly whitened, X: Whitened significantly.
(* 4) Storage property The paint state after each sample sample was stored at 40 ° C for 1 month was evaluated.
○: No change, Δ: Slightly thickened, ×: Agglomeration, bumpy.

Claims (3)

An unsaturated bond-containing aqueous resin having a carbodiimide group, starting from a carboxylic acid (a) having an unsaturated bond, which is a drying oil fatty acid, a carbodiimide compound (b) having an isocyanate group, and a polyalkylene glycol compound (c) , In addition, the aqueous binder resin is an aqueous monomer mixture containing an unsaturated fatty acid-modified polymerizable unsaturated monomer obtained by reacting an unsaturated fatty acid that is a drying oil fatty acid with an epoxy group-containing polymerizable unsaturated monomer. An aqueous coating composition containing an acrylic resin aqueous dispersion having a carboxyl group, which is obtained by finely dispersing in a medium such that the average particle size is 500 nm or less and polymerizing the resulting monomer emulsion. A step of reacting an unsaturated bond-containing aqueous resin having a carbodiimide group with a carbodiimide compound (b) having an isocyanate group and a polyalkylene glycol compound (c), the reaction product obtained in the above step and a dry oil fatty acid. The aqueous coating composition according to claim 1, wherein the aqueous coating composition is produced by reacting a carboxylic acid (a) having a certain unsaturated bond . A coating method for coating the surface to be coated with the aqueous coating composition according to claim 1 or 2.