JP2007308587A - Resin composition for matte coating and matte coating - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a resin composition for a matte water-based coating having excellent storage stability, water resistance and weather resistance of coating film and a coating using the same. <P>SOLUTION: The resin composition for a matte coating comprises a urethane resin water dispersion A having an average particle diameter of 1.5-4.0μm and a urethane resin water dispersion B having an average particle diameter of 0.01-1.0μm. The coating uses the resin composition. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a resin composition for a matte water-based paint excellent in storage stability and a matte paint using the same.

  Conventionally, the surface of an object to be coated has been painted with a paint for the purpose of improving aesthetics and protecting it. Examples of objects to be coated include daily products such as electrical products, office automation equipment, furniture, furniture, and toys, industrial products such as machinery and equipment, ships, vehicles, buildings, structures, plants, tanks, bridges, signs, etc. Is mentioned. In all these applications, matte paints are often used when it is necessary to create a calm textured appearance with reduced gloss (gloss). For example, in the field of architecture and civil engineering, a design coating film such as a natural stone-like coating material or a multicolored paint is often applied to the wall surface of a building or structure. Also, in a vehicle interior, it is common to apply a transparent matte paint with reduced gloss. In addition, in recent years, conversion from solvent-based paints to water-based paints is being promoted in accordance with environmental regulations. Accordingly, water-based ones are increasingly required for the transparent matte paint.

  A water-based transparent matte coating is generally obtained by blending a matting agent such as silica, calcium carbonate, or polymer fine particles with an aqueous resin or the like. However, simply adding a matting agent to a water-based resin, etc. may cause poor storage stability, such as separation and thickening during storage, and when such matte paint is applied. , Gloss unevenness occurs in the formed coating film, and an excellent matting effect may not be exhibited. In addition, other desirable requirements for water-based matte paints are that a high matte effect can be obtained, that there is no gloss due to friction, etc., that weather resistance and water resistance are excellent, and that the coating film is smooth. Etc. can be mentioned.

  In order to satisfy the above requirements, in Patent Document 1, glossiness is adjusted by using polyolefin wax particles having an average particle diameter of 0.1 to 100 μm instead of the matting agent, and weather resistance and water resistance are also improved. Provides paint. Further, in Patent Document 2, a matting effect is expressed without using a matting agent by controlling the solubility parameter of each polymer obtained by synthesizing resin compositions for paints having different compositions in two stages. ing. In Patent Document 3, a coating composition having a matting property is obtained by using two types of silicone particles having different particle diameters as a matting agent.

  However, the matte paint of Patent Document 1 has good weather resistance and water resistance, but has poor compatibility with the acrylic resin emulsion, which is a resin component, and thus has difficulty in storage stability such as causing separation over time. is there. That is, this matting paint has the same drawbacks as when an inorganic matting agent is used. Moreover, when the particle diameter of the polyolefin wax is large, the coating film has a rough surface, and there are drawbacks such as peeling off due to friction and partial gloss.

  Further, in the matte paint of Patent Document 2, since the resin component itself exhibits a matte effect, the storage stability is good, but there is a disadvantage that the composition of the resin component is limited and expensive. There is a problem in that it is economically disadvantageous because of using an alkoxysilane or the like.

Furthermore, in the matte paint of Patent Document 3, by using silicone particles having different particle diameters, a matte effect is exhibited with a relatively small amount of blending, and since it has a silicone structure, it has good friction resistance. However, there is a problem in compatibility with the resin component, and there is a problem that the resin that can be used is limited. Moreover, when the resin composition for coating materials with bad compatibility is used, there exists a problem of causing a thickening, isolation | separation, etc.
JP 2002-309152 A JP 2000-336316 A Japanese Patent Laid-Open No. 2002-80797

  The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is to provide a matte water-borne paint resin composition having excellent storage stability and a paint using the same. It is to be.

  The resin composition for matte paint of the present invention comprises a polyurethane water dispersion A having an average particle size of 1.5 to 4.0 μm and a polyurethane water dispersion B having an average particle size of 0.01 to 1.0 μm. It is characterized by containing.

  Thereby, the polyurethane water dispersion A having a large average particle diameter and the polyurethane water dispersion B having a small average particle diameter are uniformly dispersed, the unevenness of the coating film surface becomes clear, and a high matting effect is obtained. .

  In the above, it is preferable that the solid content ratio of the polyurethane water dispersion A and the polyurethane water dispersion B is 80/20 to 20/80 by weight.

  Here, the polyurethane water dispersion A and the polyurethane water dispersion B are preferably prepared using at least one polyol selected from polyester polyols, polycarbonate polyols and polyether polyols.

  The matte paint of the present invention is characterized by using the above resin composition for matte paint.

  By using polyurethane water dispersions having different average particle sizes, the coating resin composition itself exhibits a matte effect. This eliminates the need for organic or inorganic matting agents that have been blended in matte paints so far, or requires only a very small amount, and provides a matte paint with good storage stability. In addition, the coating film obtained by using a paint blended with this has a thin coating film roughness and no or a very small amount of the particulate compound. Therefore, the matting agent peels off due to friction, resulting in gloss. The problem that it does not arise does not arise, and the effect that it is excellent in the persistence of the matting effect will be exhibited. Moreover, when there is no particulate compound or it is a very small amount, the adhesiveness of a coating film improves and the water resistance and weather resistance of a coating film improve. Furthermore, by changing the composition of the polyurethane water dispersion and the structure of the polyurethane, a wide range of response from a flexible coating film to a hard coating film can be realized.

  In the matte paint resin composition of the present invention, the urethane resin water dispersion A having an average particle diameter of 1.5 to 4.0 μm and the urethane resin water dispersion B having an average particle diameter of 0.01 to 1.0 μm. And are used. These polyurethane water dispersions in the present invention are self-emulsifying polyurethane water dispersions in which a polyurethane having a water-soluble functional group in the molecule is dispersed in water, or a forced mechanical shear force in combination with a surfactant. It is an emulsified polyurethane water dispersion emulsified.

  The polyurethane water dispersion having each average particle diameter of the present invention can be prepared by the following compounds.

  First, polyester polyols, polyether polyols, polycarbonate polyols, polyolefin polyols, and combinations thereof can be used as the polyol constituting the polyurethane.

  Examples of the polyester polyol include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, 3- Low molecular polyols such as methylpentanediol, hexamethylene glycol, 1,8-octanediol, 2-methyl-1,3-propanediol, bisphenol A, hydrogenated bisphenol A, trimethylolpropane, cyclohexanedimethanol, and succinic acid , Polycarboxylic acids such as glutaric acid, adipic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, tetrahydrofuran acid, endomethine tetrahydrofuran acid, hexahydrophthalic acid Mention may be made of the condensates.

  Examples of polyether polyols include various polyether polyols such as polyethylene glycol, polypropylene glycol, polyethylene polytetramethylene glycol, polypropylene polytetramethylene glycol, and polytetramethylene glycol. Of these, polytetramethylene glycol is preferably used when flexibility is required.

  Examples of the polycarbonate polyol include compounds obtained by reacting a carbonic acid derivative such as diphenyl carbonate, dimethyl carbonate, and phosgene with a diol. Suitable examples of diols that can be used include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol. , 3-methylpentanediol, hexamethylene glycol, 1,8-octanediol, 2-methyl-1,3-propanediol, bisphenol A, hydrogenated bisphenol A, trimethylolpropane, cyclohexanedimethanol, Of these, polycarbonate polyols using 1,6-hexanediol, 1,5-pentanediol, and 2-methyl-1,5-pentanediol, either singly or in combination, are preferred from the viewpoint of weather resistance.

  Examples of the organic polyisocyanate constituting the polyurethane include aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic polyisocyanates, and araliphatic polyisocyanates.

  Aliphatic polyisocyanates include tetramethylene diisocyanate, dodecamethylene diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2-methylpentane-1 , 5-diisocyanate, 3-methylpentane-1,5-diisocyanate and the like.

  Examples of the alicyclic polyisocyanate include isophorone diisocyanate, hydrogenated xylylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, 1,4-cyclohexane diisocyanate, methylcyclohexylene diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, and the like. Can be mentioned.

  Aromatic polyisocyanates include tolylene diisocyanate, 2,2′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate (MDI), 4,4′-dibenzyl diisocyanate, 1,5 -A naphthylene diisocyanate, a xylylene diisocyanate, a 1, 3- phenylene diisocyanate, a 1, 4- phenylene diisocyanate etc. can be mentioned.

  Examples of the araliphatic polyisocyanate include dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, α, α, α, α-tetramethylxylylene diisocyanate, and the like.

  Moreover, modified bodies, such as a dimer and a trimer of these organic polyisocyanates, and a buret-ized isocyanate, can also be mentioned. In addition, these organic polyisocyanate can also be used individually or in combination of 2 or more types.

  As the organic polyisocyanate, aliphatic and alicyclic polyisocyanates are preferably used from the viewpoint of weather resistance. Specifically, hexamethylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, isophorone diisocyanate, 1,3 -Bis (isocyanatemethyl) cyclohexane is preferably used, and among them, hexamethylene diisocyanate, which is an aliphatic isocyanate, isophorone diisocyanate, which is an alicyclic isocyanate, and 4,4'-dicyclohexylmethane diisocyanate, provide high weather resistance. It is preferable in that it is.

  Examples of the water-soluble functional group compound introduced to disperse polyurethane in water include (di) alkanol carboxylic acid or sulfonic acid tertiary amine or alkali metal neutralized product, (methoxy) polyethylene oxide, (di) alkanol Examples include neutralized organic and inorganic acids of amines, and quaternary ammonium salts obtained by reacting these with alkyl halides or dialkyl sulfuric acid. Of these, (di) neutralized products of alkanol carboxylic acids or sulfonic acids with tertiary amines or alkali metals, (di) neutralized products of alkanolamines with organic and inorganic acids, and these are reacted with alkyl halides or dialkyl sulfuric acid. Quaternary ammonium salts are preferred from the viewpoint of water resistance.

  The following can be illustrated as a compound which can introduce | transduce these water-soluble functional groups. First, as anion type, carboxylic acid compounds such as dimethylolpropionic acid, dimethylolbutanoic acid, lactic acid and glycine, sulfonic acid compounds such as polyester diol composed of taurine, sulfoisophthalic acid and diol, triethylamine, NaOH, dimethylaminoethanol And salts obtained by neutralization with tertiary alkanolamines such as

  Among these, a preferable combination is a combination of alkanolamine or alkali metal and carboxylic acid having low volatility from the viewpoint of odor, and a combination of dimethylolpropionic acid and dimethylaminoethanol or NaOH is more preferable. Further, a combination of taurine and NaOH, a polyester diol containing sodium sulfoisophthalate, and the like are also preferable.

  In addition, as cation types, salts obtained by neutralizing alkanolamines such as dimethylaminoethanol and methyldiethanolamine with organic carboxylic acids such as formic acid and acetic acid, inorganic acids such as hydrochloric acid and sulfuric acid, and halogenations such as methyl chloride and methyl bromide Quaternized with dialkyl sulfuric acid such as alkyl and dimethyl sulfuric acid. Of these, a combination of methyldiethanolamine and an organic carboxylic acid and a combination of methyldiethanolamine and dimethylsulfuric acid are preferred because they are easy to produce industrially.

  In preparing the polyurethane water dispersion in the present invention, a low molecular weight single chain polyol such as ethylene glycol or 1,4-butanediol is introduced in order to localize the urethane bond in the molecule, or a branched structure is introduced. For this purpose, it is also possible to use a single-chain polyol such as trimethylolpropane or glycerin. The use of a single-chain polyol is preferable from the viewpoint of improving the water resistance of the polyurethane water dispersion because it is possible to localize urethane bonds and introduce a branched structure.

  In preparing the polyurethane water dispersion in the present invention, a chain extender may be added to increase the molecular weight. As chain extenders, diamines such as ethylenediamine, trimethylenediamine, piperazine, and isophoronediamine, and polyamines such as diethylenetriamine, dipropylenetriamine, and triethylenetetramine may be used to introduce an internal crosslinking structure. By extending the chain in this way, it becomes possible to improve water resistance and weather resistance.

  Examples of the surfactant that can be used to disperse polyurethane in water in the present invention include polyoxyethylene alkylphenol ether, polyoxyethylene lauryl ether, polyoxyethylene styrenated phenyl ether, polyoxyethylene sorbitol tetraoleate and the like. Nonionic surfactants, fatty acid salts such as sodium oleate, alkyl sulfate esters, alkylbenzene sulfonates, alkyl sulfosuccinates, naphthalene sulfonates, alkane sulfonate sodium salts, alkyl diphenyl ether sulfonate sodium salts, etc. Anionic surfactants such as surfactants, polyoxyethylene alkylphenyl sulfates, polyoxyethylene alkyl sulfates and the like are listed, and nonionic surfactants are preferred. It is use.

  The addition amount of the surfactant is preferably an addition amount within a range that does not adversely affect the adhesion and water resistance of the finally obtained polyurethane resin to each base material, with respect to 100 parts by weight of the solid content of the polyurethane resin. It is used in the range of 15 parts by weight, preferably 10 parts by weight or less.

  The molecular weight of the polyurethane in the polyurethane water dispersion of the present invention is preferably as large as possible, and theoretically is infinite. In addition, a solvent-insoluble one by introducing a branched structure or an internal cross-linked structure is preferable because it provides a resin composition for paints excellent in weather resistance and water resistance.

  The polyurethane water dispersion A contained in the coating resin composition of the present invention has an average particle size of 1.5 to 4.0 μm. This average particle diameter can be achieved, for example, by setting the acid value of the polyurethane water dispersion A to 0 to 10 mg KOH / g and neutralizing the acid value and using a forced emulsification type polyurethane water dispersion in combination with a surfactant. it can. If the particle size is less than 1.5 μm, the matte effect is not exhibited, and if it exceeds 4.0 μm, the stability of the aqueous dispersion tends to deteriorate. A more preferable particle diameter of the polyurethane water dispersion A is 1.8 to 3.5 μm.

  The polyurethane water dispersion B contained in the coating resin composition of the present invention has an average particle size of 0.01 to 1.0 μm. This average particle diameter can be achieved, for example, by setting the acid value of the polyurethane water dispersion B to 5 to 25 mg KOH / g and neutralizing it with a self-emulsifying polyurethane water dispersion. When the particle diameter is less than 0.01 μm, the water resistance is deteriorated. A preferred particle size of the polyurethane water dispersion B is 0.02 to 0.1 μm.

  In addition, the average particle diameter in this specification means the 50% cumulative average value measured using Microtrac UPA (Nikkiso).

  In the present invention, the ratio of the polyurethane water dispersion A and the polyurethane water dispersion B is preferably in the range of 80:20 to 20:80, and more preferably in the range of 70:30 to 30:70. . Outside this range, the matting effect tends to decrease.

  Although the manufacturing method of the polyurethane water dispersion A and the polyurethane water dispersion B of this invention is not specifically limited, Generally, it can manufacture as follows. Existence of a solvent comprising a polyol component composed of a polyol, a single-chain polyol and a water-soluble functional group compound, and a polyisocyanate in an equivalent ratio of an isocyanate group of the polyisocyanate to a hydroxyl group of the polyol component of 1: 0.85 to 1.1. A urethane prepolymer is synthesized by reacting under or in an organic solvent having no active hydrogen, and then dispersed and emulsified in water by neutralizing water-soluble functional groups. Thereafter, chain-extended amine (equivalent ratio of isocyanate group to chain-extended amine 1: 0.5 to 0.9) is added, and a urea bond is generated by reaction with the isocyanate group in the emulsion micelle. Further, a urea bond may be generated by reaction with water without adding a chain extending amine. This increases the crosslink density in the emulsified micelles, resulting in a three-dimensional crosslinked structure. Thus, by setting it as a three-dimensional crosslinked structure, it becomes the resin composition for coating materials which can obtain the coating film which has the outstanding water resistance and a weather resistance. Then, the polyurethane water dispersion can be obtained by removing the solvent used as needed.

  In the present invention, the polyurethane water dispersion A and the polyurethane water dispersion B are preferably blended by mixing those synthesized and emulsified in separate reactors.

  Additives and compounding agents may be added to the matte paint resin composition of the present invention in order to impart other functions. For example, defoaming agent (foam erasing), silica, talc, clay, polyolefin wax, cross-linked unsaturated polyester, etc. are used as organic / inorganic matting agents within the range that does not deteriorate the storage stability of paint and the roughness of coating film. It can be added to give a further matting effect. Moreover, although it may be unpreferable, you may add high boiling point water-soluble solvents, such as NMP (N-methylpyrrolidone), for example as a film-forming aid. Further, an acrylic emulsion may be added for improving workability and economy as long as it is compatible with the resin composition for coatings of the present invention. If an acrylic emulsion having poor compatibility is added, the storage stability deteriorates, which is not preferable. In addition, a colorant, a thickener and the like may be added as necessary.

  Further, the resin composition for matte paint of the present invention can be blended with an inorganic pigment and / or an organic pigment to obtain an enamel paint. Examples of inorganic pigments include titanium white and carbon black, and examples of organic pigments include phthalocyanine blue and azo organic pigments. If necessary, extender pigments such as calcium carbonate and barium sulfate can be added. Moreover, it is good also as a clear paint, without adding these pigments. As a method for preparing the enamel paint, known means such as a roll, a sand mill, and a disperser can be used.

  The coating material of the present invention can be used for coating various substrates such as wood, metal, slate, roof tile, and the surface of articles according to a normal coating method. The coating can be performed, for example, by application using an air spray device, an airless spray device, an electrostatic coating machine, a roll coating machine, a brush, or by immersion.

  The present invention will be described in detail below based on examples, but the present invention is not limited to these examples.

  With the formulation shown in Table 1, polyurethane water dispersions of each synthesis example and each comparative synthesis example were prepared by the following procedure. The average particle diameter of each dispersion was measured, and the results are also shown in Table 1.

(Synthesis example 1 ... polyurethane water dispersion B)
In a four-necked flask equipped with a stirrer, a reflux condenser, a thermometer, and a nitrogen blowing tube, 78.47 parts by weight of PolyTHF2000 (manufactured by BASF, Mw = 2,000), 7.82 parts by weight of trimethylolpropane, , 24.7 parts by weight of dimethylolpropionic acid, 184.66 parts by weight of isophorone diisocyanate, and 800 parts by weight of methyl ethyl ketone were added and reacted at 75 ° C. for 4 hours. The content of free isocyanate groups with respect to the nonvolatile content was 1.2. A methyl ethyl ketone solution of urethane prepolymer in weight% was obtained. The solution was cooled to 40 ° C., and 50 parts by weight of the nonionic active agent Neugen EA-157 (Daiichi Kogyo Seiyaku Co., Ltd.) and 10 wt. Of Tinuvin 900 (Ciba Specialty Chemicals Co., Ltd.) were added to this solution. The solution was dissolved in 200 parts by weight of methyl ethyl ketone, neutralized by adding 16.64 parts by weight of dimethylethanolamine, and then emulsified and dispersed using a homogenizer while gradually adding 2700 parts by weight of water. Thereafter, 6.87 parts by weight of diethylenetriamine was dissolved in 100 g of water and added, followed by stirring for 1 hour. This was decompressed and the solvent was removed at 50 ° C. to obtain a polyurethane water dispersion 1 having a nonvolatile content of about 30% by weight and an average particle size of 0.1 μm.

(Synthesis example 2 ... polyurethane water dispersion B)
A four-necked flask equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen blowing tube was charged with 757.49 parts by weight of Nipponran 4073 (manufactured by Nippon Polyurethane Industry Co., Ltd., Mw = 2,000) and 7.57 trimethylolpropane. Parts by weight, 24.24 parts by weight of dimethylolpropionic acid, 210.70 parts by weight of dicyclohexylmethane diisocyanate, and 800 parts by weight of methyl ethyl ketone are allowed to react at 75 ° C. for 4 hours. A methyl ethyl ketone solution of urethane prepolymer having a ratio of 1.2% by weight was obtained. This solution is cooled to 40 ° C., and 100 parts by weight of the nonionic active agent Neugen EA-157 (Daiichi Kogyo Seiyaku Co., Ltd.) and 10 weight of Tinuvin 900 (Ciba Specialty Chemicals Co., Ltd.) are added to this solution. And dissolved in 200 parts by weight of methyl ethyl ketone, neutralized by adding 16.11 parts by weight of dimethylethanolamine, and then emulsified and dispersed using a homogenizer while gradually adding 2700 parts by weight of water. Thereafter, 6.87 parts by weight of diethylenetriamine was dissolved in 100 g of water and added, and stirred for 1 hour. This was decompressed and the solvent was removed at 50 ° C. to obtain a polyurethane water dispersion 2 having a nonvolatile content of about 30% by weight and an average particle size of 0.01 μm.

(Synthesis example 3 ... polyurethane water dispersion B)
In a four-necked flask equipped with a stirrer, reflux condenser, thermometer and nitrogen blowing tube, UHCARB-200 (manufactured by Ube Industries, Ltd., Mw = 2,000) 819.16 parts by weight, trimethylolpropane 8.19 parts by weight, 26.21 parts by weight of dimethylolpropionic acid, 146.44 parts by weight of hexamethylene diisocyanate, and 800 parts by weight of methyl ethyl ketone were added and reacted at 75 ° C. for 4 hours. A methyl ethyl ketone solution of a urethane prepolymer having a group content of 1.2% by weight was obtained. This solution is cooled to 40 ° C., and 10 parts by weight of the nonionic active agent Neugen EA-157100 parts by weight (Daiichi Kogyo Seiyaku Co., Ltd.) and Tinuvin 900 (by Chivas Specialty Chemicals Co., Ltd.) are added to the solution. Was dissolved in 200 parts by weight of methyl ethyl ketone, neutralized by adding 16.11 parts by weight of triethylamine, and then emulsified and dispersed using a homogenizer while gradually adding 2700 parts by weight of water. Thereafter, 6.01 parts by weight of ethylenediamine was dissolved in 100 g of water and added, and stirred for 1 hour. The pressure was reduced and the solvent was removed at 50 ° C. to obtain a polyurethane water dispersion 3 having a nonvolatile content of about 30% by weight and an average particle size of 0.01 μm.

(Synthesis example 4 ... polyurethane water dispersion A)
In a four-necked flask equipped with a stirrer, a reflux condenser, a thermometer, and a nitrogen blowing tube, 752.07 parts by weight of PolyTHF2000 (manufactured by BASF, Mw = 2,000), 12.79 parts by weight of trimethylolpropane, Then, 235.15 parts by weight of isophorone diisocyanate and 800 parts by weight of methyl ethyl ketone were added and reacted at 75 ° C. for 4 hours to obtain a methyl ethyl ketone solution of a urethane prepolymer having a free isocyanate group content of 1.2% by weight based on the nonvolatile content. Obtained. The solution was cooled to 40 ° C., and 100 parts by weight of the nonionic active agent Neugen EA-157 (Daiichi Kogyo Seiyaku Co., Ltd.) and 10 wt. Of Tinuvin 622LD (Ciba Specialty Chemicals Co., Ltd.) were added to the solution. And dissolved in 200 parts by weight of methyl ethyl ketone, and emulsified and dispersed using a homogenizer while gradually adding 2700 parts by weight of water, followed by stirring for 1 hour. The pressure was reduced and the solvent was removed at 50 ° C. to obtain a polyurethane water dispersion 4 having a nonvolatile content of about 30% by weight and an average particle size of 3.1 μm.

(Synthesis example 5 ... polyurethane water dispersion A)
In a four-necked flask equipped with a stirrer, a reflux condenser, a thermometer, and a nitrogen blowing tube, Niprolan 4073 (manufactured by Nippon Polyurethane Industry Co., Ltd., Mw = 2,000) 752.07 parts by weight and trimethylolpropane 12.79 Parts by weight, 235.15 parts by weight of isophorone diisocyanate, and 800 parts by weight of methyl ethyl ketone, reacted at 75 ° C. for 4 hours, and a urethane prepolymer having a free isocyanate group content of 1.2% by weight based on the nonvolatile content. A methyl ethyl ketone solution was obtained. The solution was cooled to 40 ° C., and 100 parts by weight of the nonionic active agent Neugen EA-157 (Daiichi Kogyo Seiyaku Co., Ltd.) and 10 wt. Of Tinuvin 622LD (Ciba Specialty Chemicals Co., Ltd.) were added to the solution. And dissolved in 200 parts by weight of methyl ethyl ketone, and emulsified and dispersed using a homogenizer while gradually adding 2700 parts by weight of water, followed by stirring for 1 hour. The pressure was reduced, and the solvent was removed at 50 ° C. to obtain a polyurethane water dispersion 5 having a nonvolatile content of about 30% by weight and an average particle size of 2.2 μm.

(Synthesis example 6 ... polyurethane water dispersion A)
In a four-necked flask equipped with a stirrer, a reflux condenser, a thermometer, and a nitrogen blowing tube, UHCARB-200 (manufactured by Ube Industries, Ltd., Mw = 2,000) 721.73 parts by weight, and trimethylolpropane 12.27 parts by weight, 266.0 parts by weight of dicyclohexylmethane diisocyanate, and 800 parts by weight of methyl ethyl ketone are added and reacted at 75 ° C. for 4 hours. The content of free isocyanate groups with respect to the nonvolatile content is 1.2% by weight. A methyl ethyl ketone solution of urethane prepolymer was obtained. This solution is cooled to 40 ° C., and 100 parts by weight of the nonionic active agent Neugen EA-157 (Daiichi Kogyo Seiyaku Co., Ltd.) and 10 weight of Tinuvin 900 (Ciba Specialty Chemicals Co., Ltd.) are added to this solution. And dissolved in 200 parts by weight of methyl ethyl ketone, and emulsified and dispersed using a homogenizer while gradually adding 2700 parts by weight of water, followed by stirring for 1 hour. The pressure was reduced, and the solvent was removed at 50 ° C. to obtain a polyurethane water dispersion 6 having a nonvolatile content of about 30% by weight and an average particle size of 2.5 μm.

(Comparative synthesis example)
In a four-necked flask equipped with a stirrer, a reflux condenser, a thermometer, and a nitrogen blowing tube, 752.07 parts by weight of PolyTHF2000 (manufactured by BASF, Mw = 2,000), 12.79 parts by weight of trimethylolpropane, Then, 235.15 parts by weight of isophorone diisocyanate and 800 parts by weight of methyl ethyl ketone were added and reacted at 75 ° C. for 4 hours to obtain a methyl ethyl ketone solution of a urethane prepolymer having a free isocyanate group content of 1.2% by weight based on the nonvolatile content. Obtained. The solution was cooled to 40 ° C., and 20 parts by weight of the nonionic active agent Neugen EA-157 (Daiichi Kogyo Seiyaku Co., Ltd.) and 10 wt. Of Tinuvin 622LD (Ciba Specialty Chemicals Co., Ltd.) were added to the solution. And dissolved in 200 parts by weight of methyl ethyl ketone, and emulsified and dispersed using a homogenizer while gradually adding 2700 parts by weight of water, followed by stirring for 1 hour. The pressure was reduced, and the solvent was removed at 50 ° C. to obtain a polyurethane water dispersion 7 having a nonvolatile content of about 30% by weight and an average particle size of 5.1 μm.

(Evaluation of coating film performance)
As shown in Table 2, the polyurethane water dispersion of each synthesis example obtained above and silica and water as necessary are blended to prepare matte paints of each example. ° Gloss and paint appearance were examined. The results are shown in Table 2. Similarly, the polyurethane water dispersions of each of the synthesis examples and comparative synthesis examples obtained above and silica and water as necessary are prepared to prepare matte paints of each comparative example, and their storage stability, The 60 ° gloss and paint appearance were also examined. The results are shown in Table 3.

(Evaluation method of coating film performance)
Evaluation of the coating film performance was performed as follows.

<Storage stability of paint>
The paint was placed in a constant temperature room at 20 ° C. and allowed to stand for 2 weeks, and then the redispersibility of the paint was evaluated. The evaluation method and evaluation criteria are as follows.

  100 g of the paint was collected in a 100 mL screw bottle and stored in an atmosphere at 20 ° C. for 2 weeks. Next, the dispersion state of the paint when the bottle was turned upside down and shaken lightly was evaluated.

○: No precipitate is generated, or precipitate is easily redispersed. △: Most of the precipitate is redispersed, but is partially solidified at the bottom and not redispersed. ×: The precipitate is solidified and redispersed. Not what.

<Gross evaluation>
The paint was applied to a concealment ratio measuring paper (manufactured by Dazai Equipment Co., Ltd.) using a bar coater so that the dry film thickness was 5 μm, and the glossiness after drying at 80 ° C. for 1 minute was evaluated. Specifically, 60 ° gloss was measured using a gloss meter (TC-108DPA, manufactured by Tokyo Denshoku Co., Ltd.). The coating appearance was visually evaluated.

<Paint appearance>
About the coating film after the said gloss evaluation, the coating external appearance was evaluated visually.

○: No coating unevenness Δ: Part of granular material is present, and coating unevenness is present ×: Many granular materials are present, and the appearance of coating is poor.

(Evaluation results of coating film performance)
As is apparent from Tables 2 and 3, the matte paint of each example was satisfactory in terms of storage stability, 60 ° gloss and paint appearance. On the other hand, the matte paint of each comparative example was inferior in terms of storage stability, 60 ° gloss and paint appearance, and was insufficient in performance.

The matting paint composition and paint of the present invention are excellent in storage stability, and are particularly suitable as interior and exterior paints for buildings and paints for plastics.

Claims (4)

  Matte paint comprising polyurethane water dispersion A having an average particle diameter of 1.5 to 4.0 μm and polyurethane water dispersion B having an average particle diameter of 0.01 to 1.0 μm Resin composition.   2. The resin composition for matte paint according to claim 1, wherein a solid content ratio of the polyurethane water dispersion A and the polyurethane water dispersion B is 80/20 to 20/80.   2. The polyurethane water dispersion A and the polyurethane water dispersion B are prepared using at least one polyol selected from polyester polyols, polycarbonate polyols and polyether polyols. Or the resin composition for mat | matte coating materials of 2. A matte paint using the resin composition for a matte paint according to any one of claims 1 to 3.