JP2005343966A - Manufacturing method of aqueous resin dispersion - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for stably manufacturing an aqueous resin dispersion which comprises a fatty acid component and exhibits a good film-forming property and good water resistance. <P>SOLUTION: The manufacturing method of the aqueous resin dispersion comprises finely dispersing a monomer mixture (I) comprising a fatty acid-modified polymerizable unsaturated monomer (A) and other polymerizable unsaturated monomers (B) copolymerizable with the monomer (A) in an aqueous medium so that the average particle size is at most 500 nm, polymerizing the resultant emulsion to give a dispersion, adding to the thus-obtained dispersion a monomer component (II) comprising a polymerizable unsaturated monomer (C), and further proceeding polymerization. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention includes a method for producing an aqueous resin dispersion that is substantially free of volatile organic compounds and that forms a film having excellent film-forming properties at low temperatures, weather resistance, corrosion resistance, and the like, and the aqueous resin dispersion. And an aqueous coating composition comprising the aqueous resin composition.

  In recent years, in the fields of paints, inks, adhesives, etc., from the viewpoint of resource saving, environmental hygiene, non-pollution, non-hazardous materials, etc., conversion from organic solvent type compositions to aqueous type compositions has been promoted. . For example, examples of the vehicle used in the aqueous coating composition include resins such as alkyd resins, acrylic resins, polyester resins, polyurethane resins, and epoxy resins. In these resins for water-based paint compositions, the alkyd resin can introduce an oxidatively curable group into the resin skeleton by using an unsaturated fatty acid as a raw material. As a result, the water-based paint composition using the alkyd resin Can be cured at room temperature, and because of its oiliness, it can be expected to have anti-corrosion properties when applied to a metal surface. On the other hand, its soft property delays drying of the coating film, and is generally weather resistant. Reduce sex. On the other hand, the acrylic resin is inferior in anticorrosion property although it is excellent in quick drying property and weather resistance. As an aqueous resin material having the characteristics of these two types of resins, a graft resin in which an alkyd resin and an acrylic resin are bonded by a chemical reaction has been developed and many have been proposed.

  For example, Patent Documents 1, 2, and 3 disclose that a fatty acid-modified monomer obtained by reacting an unsaturated fatty acid having a non-conjugated double bond with a glycidyl ester of an α, β-ethylenically unsaturated acid and α, β -An unsaturated monomer such as an ethylenically unsaturated carboxylic acid is copolymerized in an organic solvent, and the carboxyl group in the resulting resin is neutralized with a basic substance and then diluted with water to obtain a water-soluble product of resin or water A method for producing a dispersion is disclosed. However, the hydrophilic resin produced by this method requires solution of the produced polymer in an organic solvent in order to go through solution polymerization, and it is generally difficult to increase the molecular weight. In order to make a polymer water-soluble or water-dispersed, a large amount of a monomer or emulsifier having a hydrophilic group such as a carboxyl group or a hydroxyl group must be used, and as a result, a polymer is formed. There is a problem that the coating film has insufficient water resistance.

  Patent Document 4 discloses a fatty acid obtained by reaction of a dry oil fatty acid or semi-dry oil fatty acid with an α, β-ethylenically unsaturated acid glycidyl ester in the presence of a surfactant and / or a polymer protective colloid. It has been disclosed that an oxidation polymerization type aqueous emulsion is produced by emulsion polymerization of a radically polymerizable monomer mixture containing a modified monomer.

  By the way, the formation mechanism of the emulsion polymer is such that the monomer diffuses in the water from the large monomer droplets in the aqueous phase, and the polymerization proceeds in the micelles made by the surfactant so that the polymer particles (polymerized small particles) It consists of creating. In this case, the monomer used for the polymerization must be supplied by diffusing water from the monomer droplets to the polymer particles under the conditions for polymerization.

  In general, there is a large particle size difference between monomer droplets and polymer particles growing from micelles. This means that there is a large difference between the total surface area of the monomer droplets and the total surface area of the polymer particles, so that the initiator radical and the monomer diffusing in water penetrate the larger surface area, that is, the polymer particles, The polymerization then proceeds. In the emulsion polymerization method, polymer particles grow while the particle diameter gradually increases.

  In the case of emulsion polymerization of a radically polymerizable monomer mixture containing the above fatty acid-modified monomer, the fatty acid-modified monomer having extremely poor solubility in water is left in the monomer droplets in the polymerization stage, and polymerization proceeds in the monomer droplets. Polymer particles containing a large amount of fatty acid-modified monomer units are formed, while monomers other than the fatty acid-modified monomer diffuse in water from the monomer droplets into the micelles, where the polymer contains many monomer units other than the fatty acid-modified monomer units. Since the particles are generated, there is a high possibility that the nonuniform distribution of the hydrophilic polymer particles and the hydrophobic polymer particles is extremely generated in the polymer particles in the finally obtained emulsion. Therefore, in the coating film formed from such an oxidation polymerization type aqueous emulsion, the hydrophobic polymer particles become nuclei and cause repelling, or the surface floats and remains sticky on the surface. Therefore, there is a problem that a transparent film cannot be formed and the finished appearance of the coating film is remarkably deteriorated.

As a measure for overcoming the above problems, Patent Document 5 proposes an aqueous copolymer containing a copolymer that is a polymerization product of a vinyl monomer and a hydrophobic ester or a partial ester, and a method for producing the same. . Patent Document 5 proposes to add a hydrophobic ester from a dry oil acid and a polyol to the monomer droplets in order to suppress the formation of second generation particles other than the monomer droplets during the polymerization. The water-based copolymer described in Patent Document 5 does not contain a volatile coalescing aid and forms a transparent film. However, particularly in the initial stage after application, the drying property is slow, and in practice, the film remains sticky. In addition, there are drawbacks such as insufficient weather resistance and water resistance of the formed coating film.
JP 50-126723 A JP-A-56-5863 JP-A-60-212469 JP 59-8773 A JP 2000-319525 A

  The main object of the present invention is to provide a method for stably producing an aqueous resin dispersion containing a fatty acid component having good film-forming properties and water resistance.

  As a result of intensive studies to achieve the above object, the present inventors finely dispersed a monomer mixture containing a fatty acid-modified polymerizable unsaturated monomer in an aqueous medium so as to have a specific average particle size, By adding a monomer mixture containing a polymerizable unsaturated monomer to the dispersion obtained by polymerizing the resulting emulsion, the polymerization stability and storage stability are both good and water resistance. The inventors have found that an aqueous resin composition that forms a coating film excellent in film-forming properties can be obtained, and have completed the present invention.

  Thus, the present invention provides a monomer mixture (I) comprising a fatty acid-modified polymerizable unsaturated monomer (A) and another polymerizable unsaturated monomer (B) copolymerizable with the monomer (A) in an aqueous medium. A monomer component (II) containing a polymerizable unsaturated monomer (C) is added to a dispersion obtained by finely dispersing an average particle size of 500 nm or less and polymerizing the resulting emulsion. Furthermore, the present invention provides a method for producing an aqueous resin dispersion characterized by polymerizing.

  The present invention also provides an aqueous resin composition comprising the above aqueous resin dispersion.

  The present invention further provides an aqueous coating composition comprising the above-mentioned aqueous resin composition.

  According to the method of the present invention, an aqueous resin dispersion containing a fatty acid-modified monomer unit can be stably produced without using a large amount of an organic solvent or a large amount of an auxiliary surfactant. Further, the aqueous resin composition and the aqueous coating composition containing the aqueous resin dispersion are excellent in storage stability and are one-pack type, and can be easily formed at room temperature without using a large amount of a film-forming auxiliary. And can be cured.

  Hereinafter, the present invention will be described in more detail.

  The method of the present invention comprises, in an aqueous medium, a monomer mixture (I) comprising a fatty acid-modified polymerizable unsaturated monomer (A) and another polymerizable unsaturated monomer (B) copolymerizable with the monomer (A). A monomer component (II) containing a polymerizable unsaturated monomer (C) is added to a dispersion obtained by finely dispersing the polymer so that the average particle diameter is 500 nm or less and polymerizing the resulting monomer emulsion. And is further polymerized.

  In the method of the present invention, when the average particle size of the monomer mixture (I) particles in the emulsion exceeds 500 nm, sedimentation during storage of the monomer emulsion and the hydrophilic-hydrophobic composition distribution of the resulting aqueous resin dispersion particles This is not preferable because the non-uniformity of the film becomes extreme and may cause the cloudiness of a coating film formed by using it.

  In this specification, “average particle size” is obtained by diluting a sample with deionized water, and using “SALD-3100” (trade name, manufactured by Shimadzu Corporation, laser diffraction particle size distribution analyzer) at room temperature ( The average particle size is measured within 24 hours after the production of the finely divided monomer emulsion or aqueous resin dispersion.

  Moreover, as an aqueous medium used at the time of superposition | polymerization, the water-organic solvent mixed solution etc. which mix water and organic solvents, such as a water-soluble organic solvent, can be mentioned to this.

Fatty acid-modified polymerizable unsaturated monomer (A)
The fatty acid-modified polymerizable unsaturated monomer (A) used in the method of the present invention facilitates atomization at the time of emulsification of the monomer mixture, and stabilizes the monomer emulsion after atomization in the polymerization stage. In order to suppress diffusion of the polymerizable unsaturated monomer (B) into the aqueous medium, and to give a feeling of meat to the finish of the coating film formed using the aqueous resin dispersion particles produced, In addition, it is used for introducing an oxidative curable group into the aqueous resin dispersion particles, and includes a polymerizable unsaturated monomer having a polymerizable unsaturated group at the end of a hydrocarbon chain derived from a fatty acid. Here, examples of the polymerizable unsaturated group include a vinyl group and a (meth) acryloyl group, and a (meth) acryloyl group is particularly preferable.

  Examples of the fatty acid-modified polymerizable unsaturated monomer (A) include those obtained by reacting a fatty acid (a1) with an epoxy group-containing polymerizable unsaturated monomer (a2) or a hydroxyl group-containing polymerizable unsaturated monomer (a3). Can be mentioned.

  Examples of the fatty acid (a1) include those having a structure in which a carboxyl group is bonded to the end of a hydrocarbon chain, and examples thereof include a dry oil fatty acid, a semi-dry oil fatty acid, and a non-dry oil fatty acid. Dry oil fatty acids and semi-dry oil fatty acids cannot be strictly distinguished, but usually dry oil fatty acids are unsaturated fatty acids that are iodinated 130 or more, and semi-dry oil fatty acids are 100 or more and less than 130 iodinated. Of unsaturated fatty acids. On the other hand, non-drying oil fatty acids are usually fatty acids having an iodine value of less than 100.

  Examples of the dry oil fatty acid and the semidry oil fatty acid include fish oil fatty acid, dehydrated castor oil fatty acid, safflower oil fatty acid, linseed oil fatty acid, soybean oil fatty acid, sesame oil fatty acid, poppy oil fatty acid, eno oil fatty acid, hemp oil fatty acid, grape Nuclear oil fatty acid, corn oil fatty acid, tall oil fatty acid, sunflower oil fatty acid, cottonseed oil fatty acid, walnut oil fatty acid, rubber seed oil fatty acid, hydienoic acid fatty acid and the like can be mentioned. , Hydrogenated coconut oil fatty acid, palm oil fatty acid and the like. These can be used alone or in combination of two or more. Furthermore, these fatty acids can be used in combination with caproic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid and the like.

  The epoxy group-containing polymerizable unsaturated monomer (a2) that can be reacted with the fatty acid (a1) in order to produce the fatty acid-modified polymerizable unsaturated monomer (A) includes one epoxy group and one epoxy group in one molecule. The compound which has the following polymerizable unsaturated group is included, for example, glycidyl (meth) acrylate, (beta) -methylglycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, 3,4- Examples thereof include epoxycyclohexylethyl (meth) acrylate, 3,4-epoxycyclohexylpropyl (meth) acrylate, and allyl glycidyl ether. These can be used alone or in combination of two or more.

  The fatty acid (a1) and the epoxy group-containing polymerizable unsaturated monomer (a2) have an equivalent ratio of a carboxyl group in the fatty acid (a1) and an epoxy group in the epoxy group-containing monomer (a2) of 0.75: 1 to 1. The reaction can be carried out in such a ratio that it is in the range of 1.25: 1, preferably 0.8: 1 to 1.2: 1.

  The reaction between the fatty acid (a1) and the epoxy group-containing polymerizable unsaturated monomer (a2) is usually carried out in the presence of a polymerization inhibitor without causing a problem such as gelation in the fatty acid component. The reaction can be carried out under conditions that allow the group and the epoxy group in the epoxy group-containing polymerizable unsaturated monomer to react smoothly, and is usually heated at a temperature of about 100 to about 180 ° C. for about 0.5 to about 10 hours. Is suitable.

  In this reaction, an esterification reaction catalyst such as a tertiary amine such as N, N-dimethylaminoethanol, a quaternary ammonium salt such as tetraethylammonium bromide or tetrabutylammonium bromide can be used. An inert organic solvent may be used.

  Examples of the polymerization inhibitor include hydroxy compounds such as hydroquinone, hydroquinone monomethyl ether, pyrocatechol and p-tert-butylcatechol; nitrobenzene, nitrobenzoic acid, o-, m- or p-dinitrobenzene, 2,4- Nitro compounds such as dinitrotoluene, 2,4-dinitrophenol, trinitrobenzene, and picric acid; quinone compounds such as p-benzoquinone, dichlorobenzoquinone, chloranil, anthraquinone, and phenanthroquinone; nitrosobenzene, nitroso-β-naphthol, and the like Examples thereof include radical polymerization inhibitors known per se such as nitroso compounds, and these can be used alone or in combination of two or more.

The fatty acid-modified polymerizable monomer (A) can also be obtained by esterifying the fatty acid (a1) with a hydroxyl group-containing polymerizable unsaturated monomer (a3). Examples of the hydroxyl group-containing polymerizable unsaturated monomer (a3) include a compound having one hydroxyl group and one polymerizable unsaturated group in one molecule. Specifically, for example, 2-hydroxyethyl (meta ) acrylate - DOO, 2-hydroxypropyl (meth) acrylate - DOO, 3-hydroxypropyl (meth) acrylate, _C 2 -C ₈ hydroxyalkyl (meth) acrylate (meth) acrylic acid such as hydroxybutyl (meth) acrylate , Allyl alcohol, (meth) acrylate having a hydroxyl group such as a modified ε-caprolactone of the above C ₂ -C ₈ hydroxyalkyl (meth) acrylate; (meth) acrylate having a polyoxyethylene chain having a hydroxyl group at the molecular end, etc. These can be used alone or in combination of two or more. It is possible.

  The fatty acid (a1) and the hydroxyl group-containing polymerizable unsaturated monomer (a3) usually have an equivalent ratio of 0.4: 1 to the carboxyl group in the fatty acid (a1) to the hydroxyl group in the hydroxyl group-containing monomer (a3). The reaction can be carried out in such a ratio that it is in the range of 1.25: 1, preferably 0.5: 1 to 1.2: 1.

  The reaction between the fatty acid (a1) and the hydroxyl group-containing polymerizable unsaturated monomer (a3) is usually carried out in the fatty acid (a1) component in the presence of a polymerization inhibitor without causing a reaction problem such as gelation. In the presence of an esterification catalyst, usually at a temperature of about 100 to about 180 ° C. It is suitable to heat for about 0.5 to about 10 hours. Examples of the esterification catalyst include sulfuric acid, aluminum sulfate, potassium hydrogen sulfate, alkyl-substituted benzene, hydrochloric acid, methyl sulfate, phosphoric acid, and the like. These catalysts usually contain the fatty acid (a1) to be reacted and a hydroxyl group. It can be used in the range of about 0.001 to about 2.0% by weight, based on the total amount of polymerizable unsaturated monomer (a3). Furthermore, an organic solvent inert to the reaction can also be used.

  Examples of the polymerization inhibitor include hydroxy compounds such as hydroquinone, hydroquinone monomethyl ether, pyrocatechol and p-tert-butylcatechol; nitrobenzene, nitrobenzoic acid, o-, m- or p-dinitrobenzene, 2,4- Nitro compounds such as dinitrotoluene, 2,4-dinitrophenol, trinitrobenzene, and picric acid; quinone compounds such as p-benzoquinone, dichlorobenzoquinone, chloranil, anthraquinone, and phenanthroquinone; nitrosobenzene, nitroso-β-naphthol, and the like Examples thereof include radical polymerization inhibitors known per se such as nitroso compounds, and these can be used alone or in combination of two or more.

Other polymerizable unsaturated monomer (B)
The other polymerizable unsaturated monomer (B) used in the method of the present invention is a polymerizable unsaturated monomer copolymerizable with the fatty acid-modified polymerizable unsaturated monomer (A), and has at least one in the molecule. Preferably, compounds containing only one polymerizable unsaturated group such as vinyl group, (meth) acryloyl group and the like are included.

Specific examples of such other polymerizable unsaturated monomer (B) include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, n -Butyl (meth) acrylate, i-butyl (meth) acrylate, tert-butyl (meth) acrylate, n-hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate , Tridecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) Ak An alkyl or cycloalkyl (meth) acrylate such as a rate, cyclododecyl (meth) acrylate; a polymerizable unsaturated compound having an isobornyl group such as isobornyl (meth) acrylate; an adamantyl group such as adamantyl (meth) acrylate; Polymerizable unsaturated compounds having: vinyl aromatic compounds such as styrene, α-methylstyrene, vinyltoluene; vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, γ- (meth) acryloyloxypropyl Polymerizable unsaturated compounds having alkoxysilyl groups such as trimethoxysilane and γ- (meth) acryloyloxypropyltriethoxysilane; silicon oligomers such as polydimethylsiloxane macromonomer; perfluorobuty Perfluoroalkyl (meth) acrylates such as ruethyl (meth) acrylate and perfluorooctylethyl (meth) acrylate; polymerizable unsaturated compounds having a fluorinated alkyl group such as fluoroolefin; and photopolymerizable functional groups such as maleimide groups Polymeric unsaturated compounds having: vinyl compounds such as N-vinylpyrrolidone, ethylene, butadiene, chloroprene, vinyl propionate and vinyl acetate; carboxyl groups such as (meth) acrylic acid, maleic acid, crotonic acid and β-carboxyethyl acrylate (Meth) acrylonitrile, (meth) acrylamide, dimethylaminopropyl (meth) acrylamide, dimethylaminoethyl (meth) acrylate, adducts of glycidyl (meth) acrylate and amines, etc. Nitrogen polymerizable unsaturated compounds; (meth) acryl such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, etc. (Meth) acrylates having hydroxyl groups such as C ₂ -C ₈ hydroxyalkyl (meth) acrylates of acids, allyl alcohols, and ε-caprolactone modified products of the above C ₂ -C ₈ hydroxyalkyl (meth) acrylates; A polymerizable unsaturated compound having a hydroxyl group such as (meth) acrylate having a polyoxyethylene chain, a (meth) acrylate having a polyoxyethylene chain having a molecular terminal alkoxy group; 2-acrylamido-2-methylpropanesulfone Acid, allyl sulfonic acid, styrene Polymerizable unsaturated compounds having a sulfonic acid group such as sodium sulfonic acid sodium salt, sulfoethyl methacrylate and its sodium salt and ammonium salt; 2-hydroxy-4- (3-methacryloyloxy-2-hydroxypropoxy) benzophenone, 2-hydroxy -4- (3-acryloyloxy-2-hydroxypropoxy) benzophenone, 2,2'-dihydroxy-4- (3-methacryloyloxy-2-hydroxypropoxy) benzophenone, 2,2'-dihydroxy-4- (3- Addition reaction product of hydroxybenzophenones such as (acryloyloxy-2-hydroxypropoxy) benzophenone and glycidyl (meth) acrylate, or 2- (2′-hydroxy-5′-methacryloyloxyethylphenyl) -2H-benzene Polymerizable unsaturated compounds having ultraviolet-absorbing functional groups such as zotriazole; 4- (meth) acryloyloxy-1,2,2,6,6-pentamethylpiperidine, 4- (meth) acryloyloxy-2,2 , 6,6-tetramethylpiperidine, 4-cyano-4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 1- (meth) acryloyl-4- (meth) acryloylamino-2, 2,6,6-tetramethylpiperidine, 1- (meth) acryloyl-4-cyano-4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 4-crotonoyloxy-2,2 , 6,6-tetramethylpiperidine, 4-crotonoylamino-2,2,6,6-tetramethylpiperidine, 1-crotonoyl-4-crotono UV-stable polymerizable unsaturated compounds such as ruoxy-2,2,6,6-tetramethylpiperidine; acrolein, diacetone acrylamide, diacetone methacrylamide, acetoacetoxyethyl methacrylate, formylstyrol, 4-7 carbon atoms Polymerizable unsaturated compounds having a carbonyl group such as vinyl alkyl ketones having a carboxylic acid (for example, vinyl methyl ketone, vinyl ethyl ketone, vinyl butyl ketone); 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, trimethylolpropane tri (meth) acrylate, 1,4-butanediol ( (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-trishydroxymethylethanedi (meth) acrylate, 1,1,1-trishydroxymethylethanetri (meth) acrylate 1,1,1-trishydroxymethylpropane tri (meth) acrylate, triallyl isocyanurate, diallyl terephthalate, divinylbenzene, etc., at least two polymerizable unsaturated groups in one molecule May be used alone or in accordance with the performance desired for the resulting aqueous resin dispersion. Combinations of two or more can be used.

  The use ratio of the monomer (A) and the monomer (B) is not particularly limited, and can be appropriately selected according to the performance and application desired for the target aqueous resin dispersion. , Based on the total amount of monomer (A) and monomer (B), monomer (A) is in the range of 5-50 wt%, preferably 10-45 wt%, more preferably 15-40 wt%, and The monomer (B) can be in the range of 50 to 95% by weight, preferably 55 to 90% by weight, more preferably 60 to 85% by weight. When the proportion of the monomer (A) used is less than 5% by weight, the oxidative curing of the coating formed using the resulting aqueous resin dispersion does not proceed sufficiently, and the feeling of fleshiness of the coating may be impaired. On the other hand, if it exceeds 50% by weight, the cured film formed using the resulting aqueous resin dispersion may become brittle and the weather resistance may be insufficient.

  In the method of the present invention, the other polymerizable unsaturated monomer (B) and the polymerizable unsaturated monomer (C) are the other polymerizable unsaturated monomer (B) from the viewpoint of the film forming property of the aqueous resin dispersion. The (co) polymer has a theoretical glass transition temperature (Tg1) in the range of −30 ° C. to 30 ° C., preferably −20 ° C. to 20 ° C., and (co) heavy composed of the polymerizable unsaturated monomer (C). The theoretical glass transition temperature (Tg2) of the coalescence is 20 to 100 ° C, preferably 30 to 80 ° C, and the difference between Tg1 and Tg2 is 0 to 120 ° C, preferably 30 to 100 ° C. It is desirable to select such that

  In the present invention, the glass transition temperature (absolute temperature) is a value calculated by the following formula.

1 / Tg = W ₁ / T ₁ + W ₂ / T ₂ +... W _n / T <sub>n

Wherein, W 1, W 2 ... W</sub> n is the weight percent of each monomer [= (amount / total weight of the monomers in each monomer) × _{100], T 1, T 2 ... T} n ho of each monomer
It is the glass transition temperature (absolute temperature) of the mopolymer. Each monomer
The glass transition temperature of the homopolymer of Polymer Hand Book (Second
Edition, J. Brandrup / EHImmergut))
The glass transition temperature of a monomer not listed is
The polymer is synthesized with a weight average molecular weight of about 50,000,
The value when the lath transition temperature is measured by differential scanning thermal analysis is used.

  In the present invention, the other polymerizable unsaturated monomer (B) is an acid group-containing polymerizable unsaturated monomer (b1) based on the total weight of the monomer (A) and the monomer (B). It is desirable to comprise within a range of ˜5% by weight, preferably 0.5% by weight or more and less than 3% by weight.

  Examples of the acid group-containing polymerizable unsaturated monomer (b1) include polymerizable unsaturated monomers having a carboxyl group such as (meth) acrylic acid, maleic acid, crotonic acid, and β-carboxyethyl acrylate; 2-acrylamide-2 -Methylpropane sulfonic acid, allyl sulfonic acid, sodium styrene sulfonate, sulfoethyl methacrylate and polymerizable unsaturated compounds having a sulfonic acid group such as a sodium salt or an ammonium salt thereof may be mentioned. Acid and crotonic acid are preferred.

  By using the acid group-containing polymerizable unsaturated monomer (b1) as at least a part of the other polymerizable unsaturated monomer (B), the stability and mechanical stability of the resulting aqueous resin dispersion particles in an aqueous medium In addition, when the aqueous resin composition containing the same is applied to an enamel paint, the toning property of the paint can be improved.

  In addition, the other polymerizable unsaturated monomer (B) contains, as at least a part thereof, a polymerizable unsaturated monomer containing a linear, branched or cyclic, saturated or unsaturated hydrocarbon group having 4 or more carbon atoms. It is desirable that the monomer (b2) is contained in the range of 30 to 90% by weight, preferably 35 to 85% by weight, based on the total weight of the monomer (A) and the monomer (B).

  Examples of the polymerizable unsaturated monomer (b2) containing a hydrocarbon group having 4 or more carbon atoms include n-butyl (meth) acrylate, i-butyl (meth) acrylate, tert-butyl (meth) acrylate, n -Hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, tridecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, "isostearyl acrylate" Alkyl or cycloalkyl such as (produced by Osaka Organic Chemical Co., Ltd.), cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, cyclododecyl (meth) acrylate, etc. (Meta) acryle G; Polymerizable unsaturated compounds having an isobornyl group such as isobornyl (meth) acrylate; Polymerizable unsaturated compounds having an adamantyl group such as adamantyl (meth) acrylate; Vinyl aromatics such as styrene, α-methylstyrene and vinyltoluene A compound etc. can be mentioned. By using the polymerizable unsaturated monomer (b2) having a hydrocarbon group having 4 or more carbon atoms, the water resistance of the coating film formed from the obtained aqueous resin dispersion particles can be improved.

  In addition, the other polymerizable unsaturated monomer (B) includes, as at least a part thereof, a polymerizable unsaturated monomer (b3) containing a linear or branched hydrocarbon group having 6 or more carbon atoms. It is desirable to comprise within a range of 1 to 30% by weight, preferably 5 to 20% by weight, based on the total weight of (A) and monomer (B).

  Examples of the polymerizable unsaturated monomer (b3) containing a linear or branched hydrocarbon group having 6 or more carbon atoms include n-hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl ( And (meth) acrylate, nonyl (meth) acrylate, tridecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, “isostearyl acrylate” (manufactured by Osaka Organic Chemical Co., Ltd.), etc. It can be used alone or in combination of two or more.

  By using the polymerizable unsaturated monomer (b3) containing a linear or branched hydrocarbon group having 6 or more carbon atoms as at least a part of the other polymerizable unsaturated monomer (B), A coating film that can maintain the polymerization stability of the monomer emulsion after atomizing the other polymerizable unsaturated monomer (B) together with the fatty acid-modified polymerizable unsaturated monomer (A) and has excellent water resistance. A water-based resin dispersion that forms can be produced.

  The other polymerizable unsaturated monomer (B) preferably contains the cycloalkyl group-containing polymerizable unsaturated monomer (b4) as at least a part from the viewpoint of the weather resistance of the formed coating film. As the cycloalkyl group-containing polymerizable unsaturated monomer (b4), a compound having one cycloalkyl group having 6 or more carbon atoms and one polymerizable unsaturated bond in one molecule is suitable. Examples thereof include cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, cyclododecyl (meth) acrylate, and the like. These can be used in combination. The polymerizable unsaturated monomer (b4) is 1 to 70% by weight, preferably 10 to 60% by weight, more preferably 25 to 45% by weight, based on the total weight of the monomer (A) and the monomer (B). It is desirable to comprise within the range.

  The other polymerizable unsaturated monomer (B) preferably contains the aromatic vinyl monomer (b5) as at least a part thereof. Examples of the aromatic vinyl monomer (b5) include vinyl aromatic compounds such as styrene, α-methylstyrene, and vinyl toluene, and these can be used alone or in combination of two or more. By using such an aromatic vinyl monomer, the copolymerization properties of all the monomers can be improved, and the physical properties of the formed coating film such as water resistance can be improved.

  The aromatic vinyl monomer (b5) is generally 1 to 50% by weight, preferably 5 to 45% by weight, more preferably 12 to 35% by weight, based on the total weight of the monomer (A) and the monomer (B). It is preferable to use within the range of%.

  Further, the other polymerizable unsaturated monomer (B) is a hydroxyl group-containing (meth) acrylate (in order to ensure the stability of the atomized monomer emulsion in the polymerization stage or the aqueous resin dispersion particles in the storage stage. b6) may also be included. Examples of the hydroxyl group-containing (meth) acrylate (b6) include those exemplified above, and the use ratio thereof is generally 1 to 50% by weight based on the total amount of the monomer (A) and the monomer (B). , Preferably 1 to 30% by weight, more preferably 1 to 10% by weight.

  In the present invention, the monomer mixture (I) contains the fatty acid-modified polymerizable unsaturated monomer (A) and other polymerizable unsaturated monomer (B) copolymerizable with the monomer (A) as essential components. However, the monomer mixture (I) can further contain a compound (D) which does not substantially contain a polymerizable unsaturated group.

  By using the monomer mixture (I) that contains the compound (D) that does not substantially contain a polymerizable unsaturated group, aqueous resin dispersion particles that encapsulate the compound can be produced. .

  Examples of the compound (D) substantially free of a polymerizable unsaturated group include paint additives such as UV absorbers, UV stabilizers and metal dryers; acrylic resins, polyester resins, polyurethane resins, alkyd resins, poly Resins such as organosiloxanes; Colorants such as pigments and dyes, curing agents such as isocyanate compounds, blocked isocyanate compounds, and melamine resins can be mentioned, and these can be used alone or in combination and used in combination of two or more. can do.

  Examples of the ultraviolet absorber include salicylic acid derivatives such as phenyl salicylate, p-octylphenyl salicylate, 4-t-butylphenyl salicylate; 2,4-dihydroxybenzophenone, 2-hydroxy-4- Methoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone trihydrate, 2,2 ' -Dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-octadecyloxybenzophenone, sodium 2,2'-dihydroxy-4,4'-dimethoxy-5-sulfo Benzophenone, 2,2 ', 4,4'- Tetrahydroxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 5-chloro-2-hydroxybenzophenone, resorcinol monobenzoate, 2,4-dibenzoyl resorcinol, 4,6-dibenzoyl resorcinol, Benzophenone compounds such as hydroxydodecylbenzophenone and 2,2'-dihydroxy-4 (3-methacryloxy-2-hydroxypropoxy) benzophenone; benzotriazo such as 2- (2'-hydroxy-5'-methylphenyl) benzotriazole Examples thereof include acrylic compounds, other compounds such as oxalic anilide and cyanoacrylate, and acrylic copolymers having the above-described ultraviolet absorbing monomer as a copolymerization component.

  Examples of the ultraviolet stabilizer include 2- (3-t-butyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-t-butyl-2-hydroxyphenyl). ) -5-chlorobenzotriazole, poly [{6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} {(2,2,6, 6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}], dimethyl succinate 1- (2-hydroxyethyl) -4-hydroxy -2,2,6,6-tetramethylpiperidine polycondensate, 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate, bis- (2,2 ', 6,6'-Tetrame (Lu-4-piperidinyl) sebate, 4-benzoyloxy-2,2 ', 6,6'-tetramethylpiperidine, acrylic copolymers having the above-described UV-stable monomer as a copolymerization component, and the like. .

  The metal dryer includes, for example, a salt of at least one metal selected from the group consisting of aluminum, calcium, cerium, cobalt, iron, lithium, magnesium, manganese, zinc, and zirconium, and an acid. As, for example, 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. Can be mentioned.

  When the monomer mixture (I) is finely dispersed in an aqueous medium, an emulsifier may be used in combination as necessary. As the emulsifier, an anionic emulsifier and a nonionic emulsifier are suitable. Examples of the anionic emulsifier include sodium salts and ammonium salts such as alkylsulfonic acid, alkylbenzenesulfonic acid, and alkylphosphoric acid. Nonionic emulsifiers include, for example, polyoxyethylene oleyl ether, polyoxyethylene stearyl ether, polyoxyethylene lauryl ether, polyoxyethylene tridecyl ether, polyoxyethylene phenyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene octyl Phenyl ether, polyoxyethylene monolaurate, polyoxyethylene monostearate, polyoxyethylene monooleate, sorbitan monolaurate, sorbitan monos Areto, sorbitan monostearate, sorbitan trioleate, polyoxyethylene sorbitan monolaurate, and the like.

  Also, a polyoxyalkylene group-containing anionic emulsifier having an anionic group and a polyoxyalkylene group such as a polyoxyethylene group or a polyoxypropylene group in one molecule, or the anionic group and polymerizable unsaturated in one molecule Reactive anionic emulsifiers having groups may be used.

  The emulsifier can be used in the range of 0.1 to 15% by weight, preferably 0.5 to 12% by weight, based on the total amount of all monomers used.

  The monomer mixture (I) may contain a chain transfer agent for the purpose of adjusting the molecular weight of the obtained aqueous resin dispersion. Examples of the chain transfer agent include compounds having a mercapto group. Specifically, for example, lauryl mercaptan, t-dodecyl mercaptan, octyl mercaptan, 2-ethylhexyl thioglycolate, 2-methyl-5-tert- Examples thereof include butylthiophenol, mercaptoethanol, thioglycerol, mercaptoacetic acid (thioglycolic acid), mercaptopropionate, and n-octyl-3-mercaptopropionate.

  Furthermore, in the monomer mixture (I), an organic solvent such as a long-chain saturated hydrocarbon solvent such as hexadecane or a long-chain alcohol solvent such as hexadecanol may be blended as necessary.

  According to the present invention, the monomer mixture (I) described above can be finely dispersed in an aqueous medium to form a monomer emulsion.

  The concentration of the monomer mixture (I) in the aqueous medium is generally 10 to 70 from the viewpoint of atomization suitability of the monomer emulsion to be formed, stability in the polymerization stage, practicality when applied to an aqueous paint, and the like. It is suitable within the range of wt%, preferably 20-60 wt%.

  The fine dispersion of the monomer mixture (I) in the aqueous medium can be usually performed using a disperser having 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.

  The average particle diameter of the dispersed particles in the monomer emulsion obtained by finely dispersing the monomer mixture (I) in the aqueous medium by the above method is 500 nm or less from the viewpoint of the transparency of the formed coating film, water resistance, and the like. The range of 80 to 400 nm is preferable, and the range of 100 to 300 nm is more preferable.

  For polymerization of the monomer emulsion thus obtained, for example, in accordance with the mini-emulsion polymerization method, the monomer emulsion after fine dispersion is charged in a reactor equipped with a stirrer, and a polymerization initiator is added and heated while stirring. Can be done.

  The polymerization initiator may be either oil-soluble or water-soluble, and examples of the oil-soluble polymerization initiator include benzoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide. Organic peroxides such as oxides; azo compounds such as azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile), and the like, and examples of water-soluble initiators include cumene hydroperoxide. , Organic peroxides such as tert-butyl peroxide, tert-butyl peroxylaurate, tert-butyl peroxyisopropyl carbonate, tert-butyl peroxyacetate, diisopropylbenzene hydroperoxide; azobis (2-methylpropiononitrile) Azobis (2-methylbutyronitrile), 4,4′-azobis (4-cyanobutanoic acid), dimethylazobis (2-methylpropionate), azobis [2-methyl-N- (2-hydroxyethyl)- Azo compounds such as propionamide] and azobis {2-methyl-N- [2- (1-hydroxybutyl)]-propionamide}; and persulfates such as potassium persulfate, ammonium persulfate, and sodium persulfate. . These can be used alone or in combination of two or more. Further, if necessary, a reducing agent such as sugar, sodium formaldehyde sulfoxylate, or iron complex may be used in combination with the polymerization initiator to form a redox polymerization system.

  In general, the amount of the polymerization initiator used is preferably in the range of 0.1 to 5% by weight, particularly 0.2 to 3% by weight, based on the total weight of the monomer (A) and the monomer (B). The method for adding the polymerization initiator is not particularly limited, and can be appropriately selected according to the type and amount thereof. For example, it may be previously contained in the monomer mixture (I) or the aqueous medium, or may be added all at once during the polymerization, or may be dropped.

  According to the method described above, it is possible to obtain a resin dispersion having an average particle diameter of 500 nm or less, particularly preferably in the range of 100 to 300 nm.

The method of the present invention is characterized in that a monomer component (II) containing a polymerizable unsaturated monomer (C) is added to the resin dispersion obtained as described above for further polymerization.

  As the polymerizable unsaturated monomer (C), the same or different one from the polymerizable unsaturated monomer (B) described above in the description of the polymerizable unsaturated monomer (B) is appropriately selected. Can be used.

  In addition, the polymerizable unsaturated monomer (C) is obtained by converting the acid group-containing polymerizable unsaturated monomer (c1) to the polymerizable unsaturated monomer from the viewpoints of storage stability of the aqueous resin dispersion and water resistance of the formed coating film. It is desirable that it is contained within the range of 0.5 to 50% by weight, preferably 1 to 30% by weight with respect to the total weight of (C).

  Examples of the acid group-containing polymerizable unsaturated monomer (c1) include compounds having a carboxyl group such as (meth) acrylic acid, maleic acid, crotonic acid, and β-carboxyethyl acrylate; 2-acrylamido-2-methylpropanesulfone Examples thereof include polymerizable unsaturated compounds having a sulfonic acid group such as acid, allyl sulfonic acid, sodium styrene sulfonate, sulfoethyl methacrylate, and sodium and ammonium salts thereof.

  Moreover, it is desirable that the other polymerizable unsaturated monomer (C) comprises a cycloalkyl group-containing polymerizable unsaturated monomer (c2) as at least a part from the viewpoint of the weather resistance of the formed coating film. As the cycloalkyl group-containing polymerizable unsaturated monomer (c2), a compound having one cycloalkyl group having 6 or more carbon atoms in one molecule and one polymerizable unsaturated bond is preferable. Examples thereof include cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, cyclododecyl (meth) acrylate, and the like. It can be used in combination of more than one species. Such a polymerizable unsaturated monomer (c2) can be generally used in the range of 1 to 70% by weight, preferably 10 to 70% by weight, based on the total weight of the monomer (C).

  The polymerizable unsaturated monomer (C) preferably contains the carbonyl group-containing polymerizable unsaturated monomer (c3) as at least a part thereof.

  The carbonyl group-containing polymerizable unsaturated monomer (c3) includes a compound having one carbonyl group and one polymerizable unsaturated bond in one molecule, and specifically includes, for example, acrolein, diacetone acrylamide. , Diacetone methacrylamide, acetoacetoxyethyl methacrylate, formylstyrol, vinyl alkyl ketones having 4 to 7 carbon atoms (for example, vinyl methyl ketone, vinyl ethyl ketone, vinyl butyl ketone) and the like. Or in combination of two or more. Of these, diacetone (meth) acrylamide is particularly preferred.

  As at least a part of the other polymerizable unsaturated monomer (C), the one containing the carbonyl group-containing polymerizable unsaturated monomer (c3) is used, and the hydrazine derivative described later is added to the obtained aqueous resin dispersion. As a result, in addition to oxidative curing by the fatty acid (a1) component, auxiliary crosslinking between a carbonyl group-derived carbonyl group and a hydrazine derivative can be promoted, and the drying property of the coating film can be further improved. In addition, it is possible to prepare a coating composition that forms a coating film having excellent physical properties such as weather resistance and water resistance.

  The carbonyl group-containing polymerizable unsaturated monomer (c3) is generally used in an amount of 0.5 to 20% by weight, preferably 5 to 18% by weight, based on the weight of the monomer (C). ing.

  In the case where the polymerizable unsaturated monomer (C) comprises the carbonyl group-containing polymerizable unsaturated monomer (c3), the type of the fatty acid (a1) is not particularly limited, and the semi-drying oil fatty acid and / or Or it can also consist of non-drying oil fatty acids. Semi-drying oil fatty acids and / or non-drying oil fatty acids are generally fatty acids with low oxidative curability, and those exemplified above can be used.

  The monomer component (II) can appropriately contain components such as a polymerization initiator, a chain transfer agent, a reducing agent, and an emulsifier as listed above, if necessary.

  In the method of the present invention, the monomer component (II) can be dropped as it is, but it is desirable to disperse the monomer component (II) in an aqueous medium and drop it as a monomer emulsion obtained. In this case, the average particle size of the monomer emulsion is not particularly limited.

  Examples of the polymerization method of the monomer component (II) include a method in which the monomer component (II) which may be emulsified is added to the resin dispersion in a lump or dropwise and heated to an appropriate temperature while stirring. Can be mentioned.

  The aqueous resin dispersion obtained as described above has, as a core, a copolymer (I) containing a fatty acid-modified polymerizable unsaturated monomer (A) and another polymerizable unsaturated monomer (B) as a copolymerization component, Moreover, it can have a core-shell type multilayer structure in which the (co) polymer (II) having the polymerizable unsaturated monomer (C) as a (co) polymerization component is used as a shell.

  In the present invention, the ratio of the copolymer (I) to the (co) polymer (II) is determined from the viewpoint of the initial drying property and film-forming property of the formed coating film. ) It is generally desirable that the solid weight ratio of the polymer (II) is in the range of 10/90 to 90/10, particularly 20/80 to 80/20.

  The aqueous resin dispersion obtained as described above can generally have an average particle diameter in the range of 100 to 1000 nm, particularly 110 to 500 nm.

  In the present invention, in order to improve the mechanical stability of the particles of the resulting aqueous resin dispersion, when the aqueous resin dispersion has an acidic group, it is desirable to neutralize it with a neutralizing agent. . The neutralizing agent is not particularly limited as long as it can neutralize acidic groups. For example, sodium hydroxide, potassium hydroxide, trimethylamine, dimethylaminoethanol, 2-methyl-2-amino-1 -Propanol, triethylamine, aqueous ammonia and the like can be mentioned, and these neutralizing agents are desirably used in such an amount that the pH of the aqueous resin dispersion after neutralization is about 6.5 to 9.0.

Aqueous Resin Composition The aqueous resin composition provided by the present invention comprises an aqueous resin dispersion obtained as described above.

  The aqueous resin composition may further comprise a hydrazine derivative. Specific examples of the hydrazine derivative include saturated dicarboxylic acid dihydrazides having 2 to 18 carbon atoms such as oxalic acid dihydrazide, malonic acid dihydrazide, glutaric acid dihydrazide, succinic acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, and the like. Monoolefinic unsaturated dicarboxylic acid dihydrazides such as maleic acid dihydrazide, fumaric acid dihydrazide, itaconic acid dihydrazide; phthalic acid dihydrazide, terephthalic acid dihydrazide or isophthalic acid dihydrazide; pyromellitic acid dihydrazide, trihydrazide or tetrahydrazide; nitrilotrihydride Citric acid trihydrazide, 1,2,4-benzenetrihydrazide, ethylenediaminetetraacetic acid tetrahydrazide, 1,4,5,8-naphtho Tetrahydrazide; polyhydrazide obtained by reacting a low polymer having a carboxylic acid lower alkyl ester group with hydrazine or hydrazine hydrate (hydrazine hydride); hydrazide group-containing compound such as carbonic dihydrazide; bissemicarbazide; hexamethylene diisocyanate And polyfunctional semicarbazide obtained by excessively reacting N, N-substituted hydrazine such as N, N-dimethylhydrazine or the above-mentioned hydrazide with a diisocyanate such as polyisocyanate or isophorone diisocyanate or a polyisocyanate compound derived therefrom. Diisocyanate group in the reaction product of the active hydrogen compound containing a hydrophilic group such as polyether and polyol or polyethylene glycol monoalkyl ether. Aqueous polyfunctional semicarbazide obtained by excessively reacting the hydrazide; compounds having a semicarbazide group, such as a mixture of polyfunctional semicarbazide and aqueous polyfunctional semicarbazide; compound having a hydrazone group, such as bis-acetyl-di hydrazone and the like.

  By including the hydrazine derivative as described above in the aqueous resin composition, the coating film formed therefrom adsorbs harmful substances in the air, such as formaldehyde, and is useful for removing these harmful substances. When the aqueous resin dispersion has a carbonyl group, it can act as a crosslinking agent for auxiliary crosslinking.

  The amount of the hydrazine derivative is generally 0.01 to 10% by weight, particularly preferably 0.1 to 8% by weight, based on the resin solid content of the aqueous resin dispersion.

  The aqueous resin composition includes a wetting agent, an antifoaming agent, a plasticizer, a film-forming aid, an organic solvent, a thickener, an antiseptic, an antifungal agent, a pH adjuster, a curing catalyst, a surface as necessary. Additives for paints such as regulators, metal driers, UV absorbers, UV stabilizers; curing agents such as water-dispersible isocyanate compounds and water-soluble melamines can also be included.

  Thus, the water-based resin composition is used for coatings such as for building, automobile outer panels, automobile parts, coating materials such as printing inks, additives for coatings, bonding agents for nonwovens, adhesives, fillers, It can be used for various applications such as molding materials and resists.

Aqueous paint composition The present invention also provides an aqueous paint composition comprising the above-mentioned aqueous resin composition.

  The aqueous coating composition can be used as a clear coating or as an enamel coating.

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

  For example, in the case of an aqueous coating composition containing titanium white, in order to maintain the flesh-feel of the formed coating film and give a glossy finished appearance, the titanium white is generally 5 to 25%, preferably 7 to 22%. It is desirable to contain by volume pigment concentration (PVC) within the range of%. The titanium white is preferably a rutile type from the viewpoint of weather resistance. Here, the “pigment volume concentration” is a volume ratio of the pigment content in the total solid content of the total resin content and the total pigment content in the paint. In this specification, the specific gravity of the pigment which is the basis for calculating the volume of the pigment is according to “Paint Raw Material Handbook 6th Edition” (Japan Paint Manufacturers Association), and the specific gravity of the resin solids is Approximate to 1.

  In addition to the above components, the water-based paint composition is a water-soluble or emulsion-type acrylic resin, alkyd resin, silicone resin, fluororesin, epoxy resin, urethane resin, polyester resin and other modifying resins, pigment dispersant, From surfactants, dispersants, antifoaming agents, thickeners, film-forming aids, preservatives, fungicides, antifreeze agents, pH adjusters, nitrites, phytates, tannates, and polyamine compounds Low contamination such as at least one basic compound selected from the group consisting of flashlast deterrents, aldehyde scavengers, layered viscosity minerals, powdered or particulate activated carbon, photocatalytic acid value titanium, polyalkylene glycol modified alkyl silicate Additives such as oxidants; hardeners such as water-dispersible isocyanate compounds and water-soluble melamine resins, each alone or in combination of two or more It can be contained together look.

  The water-based paint composition can be applied to a new base material surface or an old coating surface, and the base material is not particularly limited. For example, concrete, mortar, slate plate, PC plate, ALC Inorganic base materials such as plates, cement calcium silicate plates, concrete blocks, wood, stones, etc .; organic base materials such as plastics; metals such as iron and aluminum, etc. Examples of the coating film include an acrylic resin system, an acrylic urethane resin system, a polyurethane resin system, a fluororesin system, a silicon acrylic resin system, a vinyl acetate resin system, an epoxy resin system, and an alkyd resin. An aqueous or solvent-type undercoat material may be applied to these coated surfaces. If necessary, after applying the undercoat material, the aqueous coating composition can be applied as a topcoat material. Further, after applying the aqueous coating composition of the present invention as an undercoat, it is also possible to apply a known aqueous overcoat.

  The aqueous coating composition of the present invention can be applied by a method such as air spray coating, airless spray coating, electrostatic coating, brush coating, roller coating, lysing gun, universal gun, etc., and as a drying method, Any of heat drying, forced drying, and room temperature drying may be used. In this specification, the drying condition of less than 40 ° C. is normal temperature drying, the drying condition of 40 ° C. or more and less than 80 ° C. is forced drying, and the drying condition of 80 ° C. or more is heat drying.

The coating amount of the aqueous coating composition of the present invention can be set in the range of 50 to 300 g / m ² , for example.

  Hereinafter, the present invention will be described more specifically with reference to examples. “Part” and “%” are “part by weight” and “% by weight”, respectively.

Production of fatty acid-modified polymerizable unsaturated monomer Production Example 1
The following components were put into a reaction vessel and reacted at a reaction temperature of 140 ° C. with stirring to obtain a fatty acid-modified polymerizable unsaturated monomer (X). The reaction between epoxy groups and carboxyl groups was quantified by measuring the amount of residual carboxyl groups. It took about 5 hours to complete the reaction.
Linseed oil fatty acid 280 parts Glycidyl methacrylate 142 parts.

Production of aqueous resin dispersion 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 preliminary emulsion, and then this preliminary emulsion is subjected to high pressure treatment at 100 MPa in a high pressure emulsifier that collides fluids by applying high pressure energy. As a result, a core monomer emulsion having an average particle size of 175 nm was obtained.

Monomer emulsion composition for core Fatty acid-modified polymerizable monomer (X) 25 parts Styrene 10 parts Methyl methacrylate 10 parts n-butyl acrylate 10 parts 2-ethylhexyl acrylate 13 parts Hydroxyethyl acrylate 1 part Acrylic acid 1 part "Newcol 707SF" (Note 1) ) 7 parts Deionized water 70 parts (Note 1) “Newcol 707SF”: trade name, manufactured by Nippon Emulsifier Co., Ltd., ammonium polyoxyethylene alkylbenzenesulfonate, active ingredient 30%.

  Next, the monomer emulsion is transferred to a flask, then heated to 85 ° C., and an initiator aqueous solution in which 1.0 part of ammonium persulfate is dissolved in 15 parts of deionized water is added to the flask, and the temperature is maintained for 2 hours. The mixture was stirred to obtain a resin dispersion having an average particle size of 165 nm.

  Next, the following components were put into another glass beaker and stirred with a disper at 2000 rpm for 15 minutes to produce a shell monomer emulsion having an average particle size of about 8 μm. Then, the temperature was maintained in the resin dispersion for 1 hour. Then, after aging for 1 hour, the solution was cooled to 40 ° C., adjusted to pH 8.0 with dimethylaminoethanol, and an aqueous resin dispersion (A-1) having a solid content concentration of 48% and an average particle size of 165 nm was obtained. Obtained.

Monomer emulsion composition for shell Styrene 6 parts Methyl methacrylate 15 parts n-Butyl acrylate 5 parts Hydroxyethyl methacrylate 2 parts Methacrylic acid 2 parts “Newcol 707SF” (Note 1) 3 parts Deionized water 14 parts.

Examples 2-8 and Comparative Examples 1-2
In Example 1, the aqueous resin dispersions (A-2) to (A) were prepared in the same manner as in Example 1 except that the blending composition and the average particle size of the core monomer emulsion were as shown in Table 1 below. -10) was obtained.

Production Example 2
The following components were sequentially charged into a pigment paste production container, and stirred with a disper until uniform for 30 minutes to obtain a pigment paste having the following composition.

Pigment paste composition Fresh water 20 parts Ethylene glycol 1 part "Sulaoff 72N" (Note 2) 0.4 part "Nopcosanto K" (Note 3) 1 part "Adecanol UH-438" (Note 4) 0.4 part "JR- "600A" (Note 5) 50 parts "SN Deformer 380" (Note 6) 0.4 part (Note 2) "Sura-off 72N": Brand name, Takeda Pharmaceutical, preservative (Note 3) "Nopcosanto K": Product Name, manufactured by San Nopco, pigment dispersant (Note 4) “Adecanol UH-438”: trade name, manufactured by Adeka, thickener (Note 5) “JR-600A”: trade name, manufactured by Teika, titanium white, Specific gravity 4.1
(Note 6) “SN deformer 380”: trade name, manufactured by San Nopco, defoamer.

Production of water-based coating composition Examples 9-16 and Comparative Examples 3-4
Aqueous resin dispersions (A-1) to (A-10) and the components listed in Table 2 below were sequentially mixed with the pigment paste obtained above to obtain each aqueous coating composition. Subsequently, each water-based coating composition was evaluated according to the following criteria. The results are shown in Table 2.

(Note 7) “DICnate 1000W”: trade name, manufactured by Dainippon Ink, metal dryer, Co content 3.6%
(Note 8) “TEXANOL”: trade name, manufactured by Eastman Chemical Co., Ltd., film-forming aid.

Evaluation Test (* 1) Surface Appearance: Each aqueous coating composition was coated on a glass plate using a 6 mil doctor blade and dried under conditions of an air temperature of 20 ° C. and a relative humidity of 60% to obtain each test coating plate. . One day later, the appearance of the coating film was visually evaluated for the feeling of meat stickiness.
○: The feeling of holding is particularly excellent.
Δ: A feeling of flesh is recognized,
X: A feeling of flesh is poor.
(* 2) Tack feeling: The test coated plate obtained in the same manner as in the above (* 1) was touched with a finger to evaluate the tack feeling.
○: No tack,
Δ: Some tack remains,
X: Tack remains considerably.
(* 3) Gloss: The 60-degree gloss of the test coated plate obtained in the same manner as (* 1) above was measured. The higher the value, the better.
(* 4) Water resistance: A steel plate (150 × 70 × 0.8 mm) specified in JIS K 5410 is degreased with xylene, and each aqueous coating composition is diluted with water to about 70 KU, and then brushed. The coating weight was 150 g / m 2 and dried for 1 week under conditions of an air temperature of 20 ° C. and a relative humidity of 60% to obtain each test coated plate. Each test coated plate was subjected to a water resistance test (96-hour immersion) according to JISK 5400 8.19. Each coated surface after the test was evaluated according to the following criteria.
○: No problem,
Δ: Swells slightly,
X: Swells considerably.

Claims (15)

  A monomer mixture (I) containing a fatty acid-modified polymerizable unsaturated monomer (A) and another polymerizable unsaturated monomer (B) copolymerizable with the monomer (A) in an aqueous medium has an average particle size of 500 nm or less The monomer component (II) containing the polymerizable unsaturated monomer (C) is added to the dispersion obtained by finely dispersing the resulting emulsion and polymerizing the resulting emulsion, and further polymerized. A method for producing an aqueous resin dispersion.   The fatty acid-modified polymerizable unsaturated monomer (A) is a reaction product of a fatty acid (a1) and an epoxy group-containing polymerizable unsaturated monomer (a2) or a hydroxyl group-containing polymerizable unsaturated monomer (a3). The method described.   Other polymerizable unsaturated monomer (B) and polymerizable unsaturated monomer (C) are in the range where the theoretical glass transition temperature (Tg1) of the (co) polymer comprising monomer (B) is within a range of -30 ° C to 30 ° C. The theoretical glass transition temperature (Tg2) of the (co) polymer comprising the monomer (C) is in the range of 20 ° C to 100 ° C, and the difference between Tg1 and Tg2 is in the range of 0 to 120 ° C. The method according to claim 1 or 2, wherein the method is selected as follows.   The polymerizable unsaturated monomer (B) is a polymerizable unsaturated monomer containing a linear, branched or cyclic, saturated or unsaturated hydrocarbon group having 4 or more carbon atoms, the monomer (A) and the monomer ( The method according to any one of claims 1 to 3, comprising 30 to 90% by weight based on the total weight of B).   The method according to any one of claims 1 to 4, wherein the polymerizable unsaturated monomer (B) comprises a polymerizable unsaturated monomer containing a cycloalkyl group.   The polymerizable unsaturated monomer (B) contains 1 to 50% by weight of the hydroxyl group-containing polymerizable unsaturated monomer based on the total weight of the monomer (A) and the monomer (B). 2. The method according to item 1.   The polymerizable unsaturated monomer (C) contains an acid group-containing polymerizable unsaturated monomer in a range of 0.5 to 50% by weight based on the total weight of the polymerizable unsaturated monomer (C). The method according to any one of 1 to 6.   The method according to any one of claims 1 to 7, wherein the polymerizable unsaturated monomer (C) comprises a cycloalkyl group-containing polymerizable unsaturated monomer.   The method according to any one of claims 1 to 8, wherein the polymerizable unsaturated monomer (C) comprises a carbonyl group-containing polymerizable unsaturated monomer.   The aqueous resin dispersion comprises a copolymer (I) core comprising a fatty acid-modified polymerizable unsaturated monomer (A) and another polymerizable unsaturated monomer (B) as a copolymerization component, and a polymerizable unsaturated monomer (C ) Is a core / shell type multilayer structure having a (co) polymer (II) shell as a constituent component, and the copolymer (I) / (co) polymer (II) The method according to any one of claims 1 to 9, wherein the solid content weight ratio is in the range of 10/90 to 90/10.   The aqueous resin dispersion manufactured by the method of any one of Claims 1-10.   An aqueous resin composition comprising the aqueous resin dispersion according to claim 11.   An aqueous coating composition comprising the aqueous resin composition according to claim 12.   A method of forming a coating film, comprising applying the aqueous coating composition according to claim 13 to a surface to be coated. A coated article formed by the method of claim 14.