JP2013001890A - Aqueous dispersion of composite resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an aqueous dispersion of a composite resin which when used as artificial leather, exhibits sufficient strength and flexibility and is excellent in hydrolysis resistance.SOLUTION: At least two raw material emulsions having compositions different from each other prepared by preliminarily dispersing one or a plurality of (meth)acrylic monomers are sequentially or continuously added into a reaction vessel in the presence of an aqueous medium, and after the end of addition of one raw material emulsion, the next raw material emulsion is added to obtain a dispersion (A). This dispersion (A) is mixed with a dispersion (B) comppsed of an aqueous dispersion of a (meth)acrylic resin in a predetermined ratio.

Description

  The present invention relates to a composite resin aqueous dispersion comprising a urethane resin and a (meth) acrylic composite resin, a coating resin dispersion using the composite resin aqueous dispersion, a laminate, and a laminate for artificial leather.

  Urethane resin is a resin used in various fields. In the production of this urethane resin, a large amount of an organic solvent is often used, which may cause a problem in the working environment and the like, and the usefulness of the self-dispersing aqueous polyurethane resin has attracted attention. For such self-dispersing water-based polyurethane resins, in recent years, in order to compensate for the disadvantages of weather resistance and solvent resistance, while taking advantage of the inherent adhesion to the base material, wear resistance, cold resistance, etc. Functionalization is performed by combining with resin.

  Urethane resin is a resin formed by polycondensation of diol and polyisocyanate, and has different properties from (meth) acrylic polymer. By combining both, the advantages of both resins can be obtained. It can be used. In order to obtain a composite resin of a (meth) acrylic polymer and a urethane resin, a method in which both are simply mixed (so-called polymer blend) is known.

  In addition, an acrylic monomer is added to the urethane resin aqueous dispersion charged in the reaction vessel and seed polymerization is performed to obtain an emulsion of the urethane-acrylic polymer in-particle mixture. A composite emulsion of a urethane resin and an acrylic resin obtained by adding a system monomer and polymerizing the mixture in the particles as a seed is known (Patent Document 1, Claim 1, [0007]).

  In this method, a urethane resin is used as a seed, an acrylic monomer is added, and a composite resin is manufactured by a batch polymerization method in which the acrylic monomer is polymerized at once. In order to obtain it, there arises a problem that the polymerization stability at the time of producing the composite resin cannot be secured unless it is divided into several times.

  Furthermore, a composite resin composed of an acrylic polymer constituting the core and a urethane polymer constituting the shell is known (Patent Document 2). The composite resin can be produced by adding an acrylic monomer to the emulsion of the urethane polymer charged in the reaction vessel for emulsion polymerization, in the presence of the acrylic polymer charged in the reaction vessel. In addition, a urethane prepolymer having a radical polymerizable group, a method of polymerizing a urethane polymer dissolved in a urethane monomer, and the like are described.

JP 2005-120304 A JP-A-9-111132

  By the way, urethane resin is difficult to achieve both durability and hydrolysis resistance and flexibility, and from the problem of cost, it improves the disadvantages of these urethane resins in artificial leather and reduces costs. Therefore, it has been studied to reduce the amount used. As this method, for example, a method of blending other resin such as acrylic resin can be mentioned.

  However, when a film is made by simply blending a urethane resin and an acrylic resin, both resins form a film separately, and the weather resistance, practical strength and flexibility as artificial leather, and hydrolysis resistance Tend to be insufficient.

  On the other hand, it is conceivable to use an emulsion obtained by the methods described in Patent Documents 1 and 2. However, in this case, the problem is slightly improved as compared with the case of simple blending, but it is not sufficient.

  Therefore, the present invention has an object to obtain an aqueous urethane- (meth) acrylic composite resin dispersion having sufficient strength and flexibility and excellent hydrolysis resistance when used as artificial leather. To do.

This invention has at least two types of aqueous dispersions of the following (A) dispersion and (B) dispersion, and the weight ratio (in terms of solid content) is (A) / (B) = 94. By setting the ratio to / 6 to 4/96, the above-mentioned problem was solved.
(A) Dispersion: A raw material emulsion in which one or more (meth) acrylic monomers are dispersed in advance is added sequentially or continuously into a reaction vessel in the presence of an aqueous medium, An aqueous dispersion obtained by emulsion polymerization of the one or more (meth) acrylic monomers in the presence of a urethane resin,
As the raw material emulsion, at least two kinds of raw material emulsions having different compositions are used, and after the addition of one raw material emulsion, the addition of the next raw material emulsion is started, and the raw material emulsion Of these, an aqueous urethane- (meth) acrylic resin dispersion containing a urethane resin as a raw material emulsion to be initially added to the reaction vessel.
(B) Dispersion liquid: (meth) obtained by polymerizing the (meth) acrylic monomer constituting (A) above with the same or different kind of (meth) acrylic monomer in an aqueous medium Acrylic resin aqueous dispersion.

  According to the present invention, a urethane- (meth) acrylic resin aqueous dispersion ((A) dispersion) and a (meth) acrylic resin aqueous dispersion obtained by sequentially adding a plurality of raw material emulsions. Since a composite resin aqueous dispersion in which a liquid ((B) dispersion) is mixed at a predetermined ratio is used, this composite has sufficient strength and flexibility when used as artificial leather and has excellent hydrolysis resistance. A resin can be obtained.

Example of chart of relationship between peel length and peel strength obtained in peel strength measurement

The present invention will be described in detail below.
The aqueous composite resin dispersion according to the present invention includes a predetermined urethane- (meth) acrylic resin aqueous dispersion (hereinafter referred to as “(A) dispersion”) and a predetermined (meth) acrylic resin aqueous dispersion. It is an aqueous dispersion having at least a liquid (hereinafter referred to as “(B) dispersion”) and mixed at a predetermined ratio. In the present invention, “(meth) acryl” means “acryl or methacryl”.

[Urethane- (meth) acrylic resin aqueous dispersion ((A) dispersion)]
In the above (A) dispersion, a raw material emulsion in which one or more (meth) acrylic monomers are dispersed in advance is added sequentially or continuously into a reaction vessel in the presence of an aqueous medium. Thus, it is an aqueous dispersion obtained by emulsion polymerization of the one or more (meth) acrylic monomers in the presence of a urethane resin.

The (meth) acrylic monomer is a monomer having a (meth) acrylic group. Among these, as a monomer used as a main component, it is preferable to use a monofunctional monomer having a general-purpose (meth) acryl group.
The main component means that the amount used exceeds 50% of the total monomer amount, or the amount used is the largest among three or more types of monomers.

  Examples of (meth) acrylic acid alkyl esters among the above (meth) acrylic monomers include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and (meth) acrylic acid. Isopropyl, butyl (meth) acrylate, isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, s-pentyl (meth) acrylate, 1-ethylpropyl (meth) acrylate, 2-methylbutyl (meth) acrylate, isopentyl (meth) acrylate, t-pentyl (meth) acrylate, 3-methylbutyl (meth) acrylate, neopentyl (meth) acrylate , Hexyl (meth) acrylate, 2-methylpentyl (meth) acrylate, 4- (meth) acrylic acid 4- Tylpentyl, 2-ethylbutyl (meth) acrylate, cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, heptyl (meth) acrylate, 2-heptyl (meth) acrylate, 3-heptyl (meth) acrylate, Octyl (meth) acrylate, 2-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, (3,3,5-acrylic acid) Trimethylhexyl, decyl (meth) acrylate, undecyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, eicosyl (meth) acrylate, (meth) acrylic acid Docosyl, (meth) acrylic acid tetracosyl, (meth) acrylic acid Chill cyclohexyl, isobornyl (meth) acrylate, (meth) norbornyl acrylate, benzyl (meth) acrylate, and (meth) phenethyl acrylate. Among these, (meth) acrylic acid alkyl esters having 1 to 24 carbon atoms in the alkyl group, particularly (meth) acrylic acid alkyl esters having 1 to 8 carbon atoms in the alkyl group are preferable.

  Examples of the (meth) acrylic monomer having a hydrophilic group (hydroxyl group, carboxyl group, ether group, etc.) preferably used in combination for stabilizing the polymerization include the following monomers. Can do. Examples of the monomer having a carboxyl group include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, and 2-acryloyloxypropionic acid.

  Moreover, as a monomer which has a hydroxyl group, hydroxylethyl (meth) acrylate, 2-hydroxyisopropyl (meth) acrylate, hydroxybutyl (meth) acrylate, ethylene glycol mono (meth) acrylate, glycerin mono (meth) acrylate, polyethylene Examples thereof include hydroxyl group-containing (meth) acrylic monomers such as glycol mono (meth) acrylate and polypropylene glycol mono (meth) acrylate.

  Furthermore, examples of the ether group-containing monomer include glycerin monoallyl ether, trimethylolpropane monoallyl ether, and allyl alcohol.

  The content of the hydrophilic group-containing monomer is preferably 0.5 parts by weight or more and preferably 1 part by weight or more when the total amount of monomers contained in the monomer mixture is 100 parts by weight. When the amount is less than 0.5 part by weight, the stability of emulsion polymerization tends not to be sufficiently improved. On the other hand, the upper limit of the content is preferably 20 parts by weight, and preferably 15 parts by weight. If the amount is more than 20 parts by weight, gelation tends to occur during polymerization, and polymerization may be difficult.

  Only one type of these components may be used, or a plurality of types may be mixed and used.

  Moreover, in addition to the (meth) acrylic monomer, the raw material emulsion containing the (meth) acrylic monomer may contain another monomer having a polymerizable double bond. . Examples of such other monomers include ester group-containing vinyl monomers, styrene derivatives, and vinyl ether monomers.

  Specific examples of the ester group-containing vinyl monomer include (meth) acrylic acid lower alkyl esters having 1 to 8 carbon atoms, vinyl acetate, diethyl maleate, dibutyl maleate, vinyl (meth) acrylate, and the like. And a hydrophobic vinyl monomer, a fluoroalkyl ester of (meth) acrylic acid, an unsaturated group-containing macromonomer such as a radically polymerizable unsaturated group-containing silicon macromonomer, and the like.

The (meth) acrylic monomer is preferably selected so that the glass transition temperature (Tg _A ) of the polymer obtained from the (meth) acrylic monomer to be used is -80 ° C. or higher. It is more preferable to select the temperature to be −65 ° C. or higher. When the (meth) acrylic monomer composition is lower than −80 ° C., the resulting film may exhibit tackiness and may cause a problem that the texture is impaired. On the other hand, the upper limit of the glass transition temperature (Tg _A ) is preferably 110 ° C., more preferably 80 ° C. When the temperature exceeds 110 ° C., the minimum film-forming temperature increases, and even when the composite resin obtained in the present invention is used, a uniform film may not be formed.

  Examples of the styrene derivative include styrene, α-methylstyrene, p-methylstyrene, vinyltoluene and the like. Furthermore, specific examples of the vinyl ether monomer include vinyl methyl ether and vinyl cyclohexyl ether.

  Furthermore, in order to improve the strength of the film formed from the resulting composite resin aqueous dispersion, the above (meth) acrylic monomer mixture includes the above-mentioned one or more types of (meth) acrylic monomers. In addition to the monomer, a polymerizable monomer having at least one carbonyl group based on a keto group or an aldehyde group in the molecule may be added. The composite resin thus obtained can be cross-linked with a polyhydric hydrazide compound, which is effective for improving the strength of the film.

  Examples of the polymerizable monomer having at least one carbonyl group based on the keto group or aldehyde group in the molecule include acrolein, diacetone acrylamide, formyl styrene, vinyl methyl ketone, vinyl ethyl ketone, vinyl isobutyl ketone, diacetone (meta ) Or one or more selected from acetylacetone (meth) acrylate.

  As a content ratio of the polymerizable monomer having at least one carbonyl group based on the keto group or aldehyde group in the molecule, 100 parts by weight of all monomers contained in the (meth) acrylic monomer When used, 0.1 part by weight or more is good, and 0.3 part by weight or more is preferable. If the amount is less than 0.1 part by weight, the effect of addition may not be sufficiently obtained. On the other hand, the upper limit of the amount used is preferably 30 parts by weight, and preferably 20 parts by weight. When the amount is more than 30 parts by weight, the reaction system may become unstable and polymerization may be inhibited.

  The urethane resin is a polymer obtained by reacting a diol component and a polyvalent isocyanate compound, and has an average particle size and molecular weight that can be mixed with the (meth) acrylic monomer, and is water dispersible. Are preferred. As such a urethane resin, a commercially available urethane aqueous emulsion may be used as it is. Specifically, manufactured by DIC Corporation: Hydran HW-301, HW-310, HW-311, HW-312B, HW-333, HW-340, HW-350, HW-375, HW-920, HW- 930, HW-940, HW-950, HW-970, AP-10, AP-20, ECOS3000, manufactured by Sanyo Chemical Industries, Ltd .: Uprene UXA-3005, Chemitylene GA-500, manufactured by Daiichi Kogyo Seiyaku Co., Ltd. : Superflex 110, Superflex 150, Superflex 260S, Superflex 210, Superflex 410, Superflex 420, Superflex 500M, Made by Adeka: Adekabon titer UHX-210, Adekabon titer UHX-280, Sumika Bayer Urethane Co., Ltd .: Dispaco Le U53, disper call U54, disper call U56, disper call U42, implantation Neil DLU, a commercially available product may be used, such as implantation Neil DLS.

  The diol component refers to an organic compound having two hydroxyl groups in one molecule. Specific examples thereof include ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4- Butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, trimethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, Relatively low molecular weight diols such as tripropylene glycol, hexanediol, cyclohexanedimethanol, or at least one of these diols and adipic acid, sebacic acid, itaconic acid, maleic anhydride, terephthalic acid, isophthalic acid Polyester diols obtained by polycondensation with at least one of the above dicarboxylic acids, polyethylene glycol, polypropylene glycol, polycaprolactone diol, polytetramethylene ether diol, polyether diols such as polycarbonate diol, others, polybutadiene diol, hydrogenated Examples thereof include polybutadiene diol and polyacrylate diol.

  The said polyvalent isocyanate compound means the organic compound which has at least 2 isocyanate group in 1 molecule, and polyhydric isocyanate compounds, such as aliphatic, alicyclic, and aromatic, can be used. Specific examples of such polyvalent isocyanate compounds include dicyclohexylmethane diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, 1,3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, 2,4-tolylene diene. Examples include isocyanate, 2,6-tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, 2,2′-diphenylmethane diisocyanate, and the like. Of these, aliphatic or cycloaliphatic isocyanates are preferred in that they have less yellowing.

  The urethane production reaction for producing the urethane resin can be performed in the absence of a solvent, but in order to perform the reaction uniformly, ethers such as dioxane, ketones such as acetone and methyl ethyl ketone, dimethylformamide, dimethylacetamide, N -Amides such as methyl-2-pyrrolidone and other organic solvents which are inert to isocyanate groups and have a high affinity for water may be used.

  In addition, the (meth) acrylic monomer and other monomers that are not reactive with an isocyanate group, that is, do not contain an active hydrogen group may be present during the production of the urethane resin. In this case, the reaction system can be diluted with the (meth) acrylic monomer and other monomers to carry out the reaction uniformly. This urethane generation reaction may be performed at about 50 to 100 ° C. for about 0.5 to 20 hours.

  The ratio of the diol component and the polyvalent isocyanate compound used in the urethane-forming reaction is not particularly limited, but the equivalent ratio is preferably diol component: polyvalent isocyanate compound = 1: 1.1 to 2, 1: 1.2-1.9 is preferable.

  If the ratio of the polyvalent isocyanate compound is higher than the above range, the reaction between the isocyanate remaining in the water dispersion and water may cause a problem that carbon dioxide gas is remarkably generated, and foaming and aggregation occur. is there. On the other hand, if the amount is less than the above range, the urethane prepolymer to be produced becomes highly viscous and may be gelled, which may cause a problem in work.

  As a catalyst used for manufacture of the urethane resin, a catalyst generally used for a urethanization reaction can be used. Specific examples include organic metal compounds such as dibutyltin dilaurate and dioctyltin dilaurate, organic amines such as triethylenediamine and triethylamine, and salts thereof.

  The urethane resin has a weight average molecular weight of preferably 500 or more, and preferably 1000 or more. If the weight average molecular weight is less than 500, the cohesive strength of the film produced using the resulting composite resin is lowered, and it may be difficult to obtain desired physical properties (elongation, etc.). On the other hand, the weight average molecular weight is preferably 500,000 or less, and preferably 100,000 or less. If it exceeds 500,000, the viscosity of the seed itself increases, and gelation may occur, or a stable (meth) acrylic monomer mixture may not be obtained.

  When the urethane resin is dispersed in an aqueous medium described later to form a urethane resin emulsion, the (meth) acrylic monomer mixture obtained by mixing the (meth) acrylic monomer is obtained. An aqueous dispersion can be obtained. This aqueous dispersion can be directly supplied to the emulsion polymerization reaction of the (meth) acrylic monomer, and the reaction system at the time of emulsion polymerization can be further stabilized, and the resulting urethane- (meth) acrylic system The dispersion system of the composite resin emulsion can be stabilized. In this case, it is possible to suppress the formation of aggregates that are likely to occur during emulsion polymerization.

  When the urethane resin emulsion is produced, it is preferable to introduce a carboxyl group into the urethane resin because it can be emulsified as a self-dispersing resin. Further, if necessary, it is preferable to use an emulsifier because the emulsion can be further stabilized.

  The emulsifier is usually used in an amount of 0.05 to 10% by weight, preferably 0.1 to 5% by weight, based on the total amount of the diol component and the polyvalent isocyanate compound. As this emulsifier, an anionic, cationic or nonionic surfactant can be used. And these emulsifiers can select and use 1 type (s) or 2 or more types.

  Specific examples of the anionic surfactant include potassium oleate, sodium laurate, sodium dodecylbenzenesulfonate, sodium alkanesulfonate, sodium alkylnaphthalenesulfonate, sodium dialkylsulfosuccinate, sodium polyoxyethylene alkyl ether sulfate. , Non-reactive surfactants such as sodium polyoxyethylene alkyl allyl ether sulfate, polyoxyethylene alkyl phosphate ester, polyoxyethylene alkyl allyl phosphate ester, and alkyl allyl sulfosuccinate (for example, Sanyo Kasei Co., Ltd .: Eleminol ( Registered trademark) JS-2, for example, manufactured by Kao Corporation: latemuru (registered trademark) S-180A, S-180, etc.), polyoxyethylene alkylpropenyl phenyl -Sulfuric acid ester ammonium salt (for example, manufactured by Daiichi Kogyo Seiyaku Co., Ltd .: Aqualon (registered trademark) HS-10, HS-5, BC-10, BC-5 etc.), α-sulfo-ω- (1 -(Nonylphenoxy) methyl-2- (2-propenyloxy) ethoxy) -poly (oxy-1,2-ethanediyl) ammonium salt (for example, Adeka Soap (registered trademark) SE-10 manufactured by Asahi Denka Kogyo Co., Ltd.) , SE-1025A and the like), polyoxyethylene-1- (allyloxymethyl) alkyl ether sulfate ammonium salt (for example, manufactured by Daiichi Kogyo Seiyaku Co., Ltd .: Aqualon (registered trademark) KH-10 and the like). ), Α-sulfo-ω- (1- (alkoxy) methyl-2- (2-propenyloxy) ethoxy) -poly (oxy-1,2-ethanedi) Yl) ammonium salt (for example, manufactured by Asahi Denka Kogyo Co., Ltd .: Adecalia Soap (registered trademark) SR-10, SR-1025, etc.), polyoxyalkylene alkenyl ether sulfate ammonium salt (for example, manufactured by Kao Corporation: Latemu) (Registered trademark) PD-104 and the like) and the like.

  Specific examples of the cationic surfactant include non-reactive surfactants such as stearylamine hydrochloride, lauryltrimethylammonium chloride, and trimethyloctadecylammonium chloride.

  Specific examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene oxypropyl block polymer, polyethylene glycol fatty acid ester, polyoxyethylene sorbitan fatty acid ester and the like. Surfactant, α-hydro-ω- (1-alkoxymethyl-2- (2-propenyloxy) ethoxy) -poly (oxy-1,2-ethanediyl)) (Asahi Denka Kogyo Co., Ltd .: Adeka Rea soap ER-10, ER-20, ER-30, ER-40), polyoxyethylene alkylpropenyl phenyl ether (Daiichi Kogyo Seiyaku Co., Ltd .: Aqualon RN-20, RN-30, RN-50), polyoxy Alkylalkenyl ether (manufactured by Kao Corporation: Latemul P Reactive surfactants such as D-420, PD-430, and PD-450).

  Furthermore, as the above-mentioned emulsifier, an amphoteric surfactant can be used as the amphoteric component in addition to those described above.

  Specific examples of the amphoteric surfactant include lauryl betaine, lauryl dimethylaminoacetic acid betaine, stearyl dimethylaminoacetic acid betaine, lauryl dimethylamine oxide, 2-lauryl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine. , 2-stearyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, lauric acid amidopropyl betaine, stearic acid amidopropyl betaine, coconut amidopropyl betaine, lauryl hydroxysulfobetaine, stearyl hydroxysulfobetaine, etc. Surfactants.

  The average particle size of the aqueous dispersion in the urethane resin emulsion is preferably 30 nm or more, and more preferably 50 nm or more. If it is less than 30 nm, the viscosity of the aqueous dispersion increases, and the fluidity may decrease. On the other hand, the thickness is preferably 1500 nm or less, and more preferably 1000 nm or less. When it exceeds 1500 nm, the average particle diameter of the resulting urethane- (meth) acrylic composite resin increases, and there is a risk of separation / sedimentation during storage. Examples of the urethane resin emulsion that satisfies such conditions include the above-described commercially available water-dispersible urethane resins.

  As the aqueous medium, water or a mixed solution of water and an organic solvent compatible with water such as methanol or ethanol can be used. Among these, it is preferable to use water from an environmental aspect.

  The solid content of the urethane resin emulsion is preferably 10% by weight or more, and preferably 25% by weight or more. If it is less than 10% by weight, the concentration of the dispersion with the (meth) acrylic monomer will be low, and the concentration of the resulting composite resin dispersion will be low. A lot of energy is required, and workability may be deteriorated. On the other hand, the upper limit is preferably 70% by weight, and preferably 60% by weight. When the amount is more than 70% by weight, the viscosity of the dispersion increases, and the workability tends to deteriorate.

  When the urethane resin is produced in an organic solvent environment, it is desirable that the organic solvent be removed by phase inversion from the organic solvent to prevent subsequent emulsion polymerization from being inhibited.

Next, (A) emulsion polymerization which is a polymerization reaction of the dispersion will be described.
As described above, the dispersion (A) is one or more of the above-described one or more in the presence of the urethane resin by sequentially or continuously adding the raw emulsion in the reaction vessel in the presence of the aqueous medium. It can be obtained by emulsion polymerization of a seed (meth) acrylic monomer.

  The raw material emulsion is an emulsion of a (meth) acrylic monomer obtained by emulsifying and dispersing the above-described one or more (meth) acrylic monomers in an aqueous medium. The raw material emulsion first added to the reactor contains a urethane resin. By using this raw material dispersion as an emulsion, it becomes easier to disperse the (meth) acrylic monomer in the aqueous medium in the emulsion polymerization reaction described later, and the dispersion can be stabilized. And the production | generation of the aggregate which tends to arise at the time of emulsion polymerization can be suppressed by stability of a dispersion system.

  In the case of the above dispersion, it is preferable to use an emulsifier in order to improve dispersibility. As this emulsifier, the same emulsifier as the above-mentioned emulsifier can be used.

  Moreover, 0.05 weight% or more is preferable with respect to the said (meth) acrylic-type monomer, and, as for content of this emulsifier, 0.1 weight% or more is preferable. If it is less than 0.05% by weight, emulsification and dispersion are not sufficiently performed, and the possibility that the reaction after addition becomes unstable becomes high. On the other hand, the upper limit is preferably 10% by weight, and more preferably 5% by weight. If it exceeds 10% by weight, the emulsifier may tend to deteriorate the water resistance and water absorption of the resulting film.

  As the raw material emulsion added to the reaction vessel, at least two kinds of raw material emulsions having different compositions are used. Then, it is preferable to add the next raw material emulsion after the addition of one raw material emulsion, that is, after the addition of one raw material emulsion is completed, the addition of the next raw material emulsion is started. Thus, when the coating film and foam obtained by using the resulting urethane- (meth) acrylic composite resin aqueous dispersion are used for artificial leather by sequentially adding a plurality of raw material emulsions Good flexibility, wear resistance, hydrolysis resistance and the like can be obtained.

  Moreover, the said urethane resin is contained at least in the raw material emulsion liquid initially added in the said reaction container among the said raw material emulsion liquid. In order to obtain a more uniform urethane- (meth) acrylic composite resin dispersion, it is also a preferred embodiment that the composition ratio is adjusted and the urethane resin is contained in another raw material emulsion.

  When the (meth) acrylic monomer is added during the urethane formation reaction of the urethane resin, the (meth) acrylic monomer used when the raw material emulsion containing the urethane resin is produced. The amount used may be obtained by subtracting the amount of the (meth) acrylic monomer used during the urethane formation reaction.

  The ratio of the total solid content of the urethane resin and the (meth) acrylic monomer in the total raw material emulsion to the total amount of the total raw material emulsion is preferably 30% by weight or more, and 40% by weight or more. Is preferable. If it is less than 30% by weight, the solid content concentration of the resulting composite resin will be low, and when forming a film, a lot of energy and time for drying will be required, which may cause operational problems. On the other hand, the upper limit is preferably 80% by weight, and preferably 70% by weight. If it exceeds 80% by weight, the viscosity of the above-mentioned mixed liquid or dispersion becomes high, and the fluidity may be lowered.

  The above raw material emulsion is sequentially added to the reaction vessel in the presence of an aqueous medium under the above-described conditions to carry out emulsion polymerization. As this aqueous medium, the same ones as described above can be used.

  It is preferable to add an emulsifier in the aqueous medium in advance, because the emulsion polymerization reaction system can be stabilized. As the emulsifier used here, the same ones as described above can be used.

  The amount of the emulsifier contained in the aqueous medium in the reaction vessel is preferably 0.05% by weight and more preferably 0.1% by weight or more based on the (meth) acrylic monomer. . If it is less than 0.05% by weight, there is a high possibility that dispersion in the reaction system will not be sufficient and the reaction system will become unstable. On the other hand, it is preferable in it being 10 weight% or less with respect to the said (meth) acrylic-type monomer, and it is more preferable in it being 5 weight% or less. If it exceeds 10% by weight, the water resistance and water absorption of the resulting film may be deteriorated by the emulsifier.

  In the emulsion polymerization, the radical polymerization initiator may be added to the aqueous medium in advance, or the radical polymerization initiator may be added dropwise in accordance with the dropping of the raw material emulsion. Also good.

  As the radical polymerization initiator, a conventional radical polymerization initiator may be used. For example, azo initiators such as azobisisobutyronitrile, azobis-2,4-dimethylvaleronitrile, azobiscyanovaleric acid, and persulfuric acid. Persulfate initiators such as sodium, potassium persulfate, ammonium persulfate, t-butyl hydroperoxide, dilauroyl peroxide, t-butylperoxy-2-ethylhexanoate, t-butylperoxypivalate, etc. An organic peroxide-based initiator can be used. A redox polymerization initiator in which an organic peroxide initiator or persulfate initiator is combined with a reducing agent such as ascorbic acid, Rongalite or metal sulfite is also preferably used. The amount of the radical polymerization initiator used is about 0.01 to 5% by weight, preferably 0.05 to 2% by weight based on the total amount of the (meth) acrylic monomer and the other monomers. It may be about%.

  The polymerization temperature of the emulsion polymerization is preferably 10 to 90 ° C, more preferably 30 to 70 ° C. This polymerization is usually almost completed by maintaining the temperature at about 40 to 90 ° C. for about 30 minutes to 3 hours after the end of heat generation. Thereby, an aqueous emulsion of urethane- (meth) acrylic composite resin is obtained.

  By the way, in the case of using a polymerizable monomer having at least one carbonyl group based on the keto group or aldehyde group in the molecule, a compound having a plurality of hydrazide groups at the terminal after emulsion polymerization (the following formula (1), , Sometimes referred to as “polyhydric hydrazide compound”), is preferable in that self-crosslinking property is exhibited. If it does in this way, the crosslinked structure will be formed at the time of film formation, and the improvement of the intensity of the film generated from the urethane- (meth) acrylic composite resin obtained can be aimed at. Moreover, the dispersion liquid of the urethane- (meth) acrylic composite resin containing the polyhydric hydrazide compound can be stably stored for a long period of time while having a self-crosslinking property.

  In the above formula (1), R represents a direct bond, a divalent hydrocarbon group having 1 to 8 carbon atoms (for example, an alkylene group, an alkenylene group, etc.), or a group represented by the following formula (2). Show.

  Examples of the compound having a plurality of hydrazide groups at the terminal (polyhydric hydrazide compound) include hydrazine derivatives having two (or more) hydrazide groups in the molecule. Specifically, dicarboxylic acid dihydrazides such as oxalic acid dihydrazide, malonic acid dihydrazide, adipic acid dihydrazide, succinic acid dihydrazide, sebacic acid dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, itaconic acid dihydrazide, 1,3-bis (hydrazino And carboethyl) -5-isopropylhydantoin. These may be used alone or in combination of two or more. Among these, adipic acid dihydrazide and 1,3-bis (hydrazide carboethyl) -5-isopropylhydantoin are preferable from the viewpoint of good solubility in water, and adipic acid dihydrazide is more preferable.

  The use amount of such a polyhydric hydrazide compound is preferably 0.1 times equivalent or more with respect to the use amount of the polymerizable monomer having at least one carbonyl group based on the keto group or aldehyde group in the molecule. , 0.3 times equivalent or more is more preferable. If the amount is less than 0.1 times equivalent, crosslinking may be insufficient and the desired effect may not be sufficiently obtained. On the other hand, the upper limit of the amount used is preferably 1.5 times equivalent, more preferably 1.2 times equivalent. When the amount is more than 1.5 times equivalent, the polyhydric hydrazide compound remaining unreacted may cause coating film defects (such as blisters and blisters).

  The addition time of the polyhydric hydrazide compound is not particularly limited as long as it is after the completion of the emulsion polymerization.For example, after the emulsion polymerization is completed and the unreacted monomer is removed, during or before and after the transfer of the dispersion, Alternatively, it may be added at the time of before or after the addition of various auxiliary agents such as an antioxidant, a filler, and a stabilizer.

  In particular, taking into account the convenience of use while taking advantage of the storage stability that is a feature of the present invention, it is often added after removal of unreacted monomers, during transfer of the produced dispersion, or before and after. From the viewpoint of uniform dispersion / dissolution of the monovalent hydrazide compound and formation of a uniform crosslinked structure during film formation.

  In the obtained dispersion (A), the weight ratio of the urethane resin component and the acrylic resin component is preferably 5/95 or more and preferably 10/90 or more in the urethane resin component / acrylic resin component. If it is less than 5/95, there may be a problem that the effect of the urethane resin component cannot be obtained. On the other hand, the upper limit of the weight ratio is preferably 85/15, and preferably 80/20. If it is larger than 85/15, there may be a problem that the durability of the film made from the obtained dispersion liquid is lowered.

[(Meth) acrylic resin aqueous dispersion ((B) dispersion)]
The (B) dispersion is a (meth) acrylic resin aqueous dispersion obtained by polymerizing a (meth) acrylic monomer in an aqueous medium. This (meth) acrylic monomer may be the same monomer as the (meth) acrylic monomer constituting the dispersion (A) described above, or a different type of monomer. Also good. Examples of the (meth) acrylic monomer include the same (meth) acrylic monomers as described above.

  As a method of polymerizing the (meth) acrylic monomer in an aqueous medium, an emulsion polymerization method used for producing the above-mentioned (A) dispersion can be employed. In this case, no urethane resin is present during emulsion polymerization. As the aqueous medium, the same aqueous medium as described above can be used.

[(A) Dispersion and (B) Dispersion]
The weight ratio (in terms of solid content) of the above (A) dispersion and (B) dispersion is (A) / (B), preferably 94/6 or less, and preferably 90/10 or less. If it is larger than 94/6, there may be a problem that the effect based on the B component cannot be obtained. On the other hand, the lower limit of the weight ratio is preferably 4/96, and preferably 10/90. If the ratio is smaller than 4/96, there may be a problem that the effect of the component A cannot be obtained (specifically, compatibility between flexibility and stickiness prevention, etc.).

From the glass transition temperature Tg _A of the polymer obtained from the (meth) acrylic monomer composition constituting the (A) dispersion, and from the (meth) acrylic monomer composition constituting the (B) dispersion. The composite glass transition temperature (Tg _total ) obtained by adding the glass transition temperature Tg _B of the obtained polymer according to the following formula <1> is preferably −15 ° C. or higher, and preferably −10 ° C. or higher. When it is lower than −15 ° C., surface tack is developed, and the strength of the film may be lowered. On the other hand, the upper limit of the composite glass transition temperature (Tg _total ) is preferably 25 ° C., and preferably 20 ° C. When it is higher than 25 ° C., there is a case where the problem of poor flexibility is caused.

1 / Tg _total = W _A / Tg _A + W _B / Tg _B <1>
In the formula <1>, W _A is, (A) dispersion and (B) to the total (meth) acrylic monomer constituting the dispersion, (A) dispersion of (meth) acrylic monomer indicates mer content, W _B is, (a) dispersion and (B) for the dispersion constitutes the entire (meth) acrylic monomer, (B) (meth) acrylic monomer in the dispersion The body content ratio is shown.

Tg _A and Tg _B can be obtained by measuring a polymer obtained from a predetermined (meth) acrylic monomer composition as described above, but other than that, it can be calculated using the FOX equation. You can also. That is, Tg _A or Tg _B may be calculated by the following formula <2> or formula <3>.
1 / Tg _A = W _A1 / Tg _A1 +... + W _An / Tg _An <2>
1 / Tg _B = W _B1 / Tg _B1 +... + W _Bn / Tg _Bm <3>
In the formulas <2> and <3>, Tg _A1 ,..., Tg _An are glass transition temperatures when (A) each (meth) acrylic monomer constituting the dispersion forms a homopolymer. Tg _B1 ,..., Tg _Bm indicate the glass transition temperature when each (meth) acrylic monomer constituting the dispersion (B) forms a homopolymer. Further, W _A1 ,..., W _An indicate the content ratio of each (meth) acrylic monomer constituting the (A) dispersion, and W _B1 ,..., W _Bm constitute (B) the dispersion. shows the proportion of each (meth) acrylic monomer which _is a _{W A1 + ... + W an =} 1, W B1 + ... + W Bm = 1. N represents the number of types of each (meth) acrylic monomer constituting the dispersion (A), and may be 1 or plural. Further, m represents the number of each (meth) acrylic monomer constituting the (B) dispersion, and may be 1 or plural.

[Composite resin aqueous dispersion]
The average particle size of the composite resin in the aqueous composite resin dispersion according to the present invention is preferably 30 nm or more, and preferably 50 nm or more. If it is smaller than 30 nm, the emulsion has a high viscosity and the workability tends to deteriorate. On the other hand, the upper limit of the average particle diameter is preferably 1500 nm (1.5 μm), preferably 1000 nm. When it is larger than 1500 nm, the stability of the resulting composite resin aqueous dispersion may be lowered, or the resin may be precipitated and separated.

  The film formed from the aqueous composite resin dispersion according to the present invention has sufficient mechanical properties such as strength and elongation, and is excellent in water resistance and water absorption.

  In particular, as described above, when a polymerizable monomer having at least one carbonyl group based on a keto group or an aldehyde group is copolymerized and used in combination with a polyhydric hydrazide compound, the formation of a crosslinked structure It is preferable because the strength of the film can be improved.

  The maximum elongation measured according to JIS-K-7161-7162 of the film formed from the composite resin aqueous dispersion according to the present invention can be 200% or more, and preferably 900% or more. If it is less than 200%, flexibility may be insufficient. On the other hand, the upper limit of the elongation is preferably 3000% and preferably 2500%. If it is greater than 3000%, the elasticity is low and the followability when applied to a woven fabric or the like tends to deteriorate.

  The breaking strength measured according to JIS-K-7161-7162 of the film formed from the aqueous composite resin dispersion according to the present invention is preferably 2 MPa or more, and preferably 5 MPa or more. When it is less than 2 MPa, the film strength is insufficient and the practicality is inferior.

  The water absorption rate of the film formed from the composite resin aqueous dispersion according to the present invention can be 30% or less, preferably 20% or less. If it exceeds 30%, the water resistance of the film may be insufficient.

[Usage]
The aqueous resin dispersion containing the composite resin aqueous dispersion according to the present invention can be used as a coating resin dispersion for coating. By coating this coating layer on the base material layer, a laminate in which the coating layer is formed on the surface of the base material layer can be obtained.

An example of such a laminate is artificial leather. The artificial leather is usually a laminate in which a resin layer is formed by applying or laminating a resin to a base material layer such as a woven fabric or a non-woven fabric. At this time, the coating liquid containing resin may permeate into the base material layer to form a three-layer structure of the base material layer, a composite layer in which the base material layer is impregnated with resin, and a resin layer. The coating liquid containing the resin may be a melt of the resin itself or a blend (liquid) containing the resin as a main constituent. At this time, the resin layer and / or the composite layer may form a foam layer having a foam structure.
In addition, the resin layer has a surface treatment such as embossing on the outer surface, or a surface layer such as an embossed coating layer, hard coat layer, or antifouling layer is laminated on the resin layer. It doesn't matter.

  Examples of the base material layer include a woven fabric, a nonwoven fabric, and a nonwoven fabric on which a woven fabric is placed. Examples of fibers constituting the nonwoven fabric and woven fabric include melt-spinnable polyamides such as 6-nylon and 66-nylon, polyethylene terephthalate, polybutylene terephthalate, and cationic dyeable modified polyethylene terephthalate. Examples thereof include synthetic fibers such as polyesters, acrylic fibers, polyolefin fibers, and polyvinyl alcohol fibers, semi-synthetic fibers such as cellulose fibers, and regenerated fibers.

  The resin impregnated in the base material layer is a general urethane resin, acrylic resin, silicon resin, or composite according to the present invention in consideration of strength, durability, and flexibility when artificial leather is used. Arbitrary resin can be used from the composite resin contained in resin aqueous dispersion, or these mixtures. When the composite resin contained in the aqueous composite resin dispersion according to the present invention is used as the impregnation resin, it is preferable because an artificial leather excellent in wear resistance, cold resistance and durability can be obtained.

  Even if the foamed layer is applied to the base material by mechanically foaming the resin dispersion in advance by stirring or the like, a chemical foaming agent such as sodium hydrogen carbonate or azodicarbonamide is added to the resin dispersion. After applying to the substrate, it may be formed by heating and foaming.

  As the foam layer, a coating layer coated with the coating resin dispersion can be used. When this is used, a good laminate excellent in tactile sensation such as elasticity can be obtained.

  The artificial leather comprising the fibrous base material laminate is first impregnated with the resin in the base material layer, then coated with the coating resin dispersion on the surface, and subjected to foam molding, Then, if necessary, by subjecting the obtained foamed layer directly to the surface treatment, or by laminating the surface layer (skin layer) that has been surface-treated, or by performing the surface treatment after the lamination of the skin layer, A fibrous base material laminate having a surface-treated skin layer can be produced, and this can also be used as artificial leather.

  As described above, the aqueous composite resin dispersion according to the present invention mixes the dispersion (A) and the dispersion (B) at a predetermined ratio, so that the strength such as maximum elongation and peel strength is improved, and surface tack is improved. Less durability and good durability can be obtained.

  Hereinafter, the present invention will be described more specifically using examples. In addition, this invention is not limited to a following example, unless the summary is exceeded.

First, the evaluation method and the raw materials used will be described.
[Measurement of glass transition temperature (Tg)]
The constituent weight fraction of each constituent monomer (polymerizable monomer) a, b,... In the vinyl copolymer is Wa, Wb,..., And the homopolymer glass of each constituent unit a, b,. When the transition temperatures were Tga, Tgb,..., The Tg value of the vinyl polymer as a copolymer was determined by the following formula of FOX.
1 / Tg = Wa / Tga + Wb / Tgb +

[Average particle size measurement]
The aqueous urethane- (meth) acrylic composite resin dispersion is diluted 10,000 times with ion-exchanged water filtered through a filter (manufactured by Advantech: DISMIC-25cs). It was filled in a measurement cell, and the average particle size was measured by a dynamic light scattering method (Otsuka Electronics Co., Ltd .: ELS-8000 used).
Note that the average particle size of the urethane aqueous dispersion was also measured in the same manner.

[Create specimen]
Various water-dispersible resins were collected so as to have a solid content of 100 parts by weight, and a coating solution prepared by the following composition was applied to the polyester felt of the fibrous layer to a thickness of 1 mm, and a 140 ° C. hot air drier. The coating film was dried to prepare a test piece for evaluation as artificial leather.

[Coating fluid]
Each of the following raw materials was well stirred and mixed with a disper, and a thickener was added to increase the viscosity of the blend so as to be 13,000 to 20,000 mPa · s. Then, it was mechanically foamed by a hand mixer, and the mixture density adjusted to 0.72 to 0.75 g / ml was used as a coating solution.
-Copolymer (solid content) ... 100 parts by weight-Antiblocking agent ... 0.73 parts by weight-Coagulant ... 0.94 parts by weight-Foaming agent ... 4.1 parts by weight-Foam stabilizer ... 5.0 parts by weight Parts / pigment: 7.5 parts by weight / curing agent: 3.0 parts by weight

[Peel strength]
The test piece produced above was cut into a width of 2.5 cm, a cyanoacrylate adhesive was applied to the foamed layer surface, pressure-bonded to an acrylic plate, and dried at room temperature for 24 hours to obtain a peel strength test piece.
This peel strength test piece was subjected to a 180 ° peel test at a crosshead speed of 100 mm / min in a measurement atmosphere of 23 ° C. and 50% RH using an Autocom C-type universal machine (manufactured by KEYS Corporation). It was. When the peel strength is measured, since the foam is peeled, the measured value of the strength fluctuates slightly, and for example, a chart of the relationship between the peel length and the peel strength per 1 cm width as shown in FIG. 1 is obtained. . The lowest measured value on this chart was taken as “minimum intensity”, the highest measured value was taken as “maximum intensity”, and the average value was taken as “average intensity”.

[Flexibility]
After bending the test piece produced above, the bent state of the bent part when returned naturally was evaluated by visual observation.
○… Returns to the state before bending, and no traces of bending are seen in the bent portion. ×… Does not return to the state before bending, or a crease or crack occurs in the bent portion.

[Surface tackiness]
The surface of the prepared test piece was checked for the presence or absence of tack by finger touch, and judged by the following evaluation.
○… No tack △… Slightly tack ×… Tack

[Abrasion resistance]
Using the Gakushin type tester (manufactured by Daiei Kagaku Co., Ltd.) for the foamed layer surface of the above-prepared test piece, CC-280 water-resistant abrasive paper (manufactured by Riken Corundum Co., Ltd.) as the friction element, load 1 kg, number of times 5000 The test was carried out at a time.
○… No change △… Slight change in wear ×… The foam layer is scraped

[Hydrolysis resistance]
The prepared test piece was treated in an atmosphere of 80 ° C. and 90% RH for 300 hours, and then the state of the surface layer was visually observed before and after the treatment to confirm the state change.
○… No change ×… Change

[Texture]
In view of flexibility, surface tack, repulsion at the time of bending, and the like, evaluation was performed according to the following criteria by finger touch.
○: Good △: Somewhat good ×: Bad

<Raw materials>
[Urethane resin]
-Sanyo Kasei Co., Ltd. product: Chemitylene GA-500 ... average particle diameter 850 nm, solid content 50.0 weight%, a polyether type non-yellowing type, and is hereafter called "GA-500".
-Made by ADEKA Co., Ltd .: Bon titer HUX-280 ... Average particle diameter 285 nm, solid content 60.0 wt%, hereinafter referred to as "HUX-280".
-Daiichi Kogyo Seiyaku Co., Ltd. product: Superflex-410 ... average particle diameter 200nm, solid content 41.0weight%, a polycarbonate type non-yellowing type, and it calls "SF-410" hereafter.

[(Meth) acrylic monomer]
・ Methyl methacrylate: manufactured by Mitsubishi Rayon Co., Ltd., hereinafter abbreviated as “MMA”.
Acrylonitrile: manufactured by Dianitricks Co., Ltd., hereinafter abbreviated as “AN”.
-Ethyl acrylate: manufactured by Mitsubishi Chemical Corporation, hereinafter abbreviated as “EA”.
・ Butyl acrylate: manufactured by Mitsubishi Chemical Corporation, hereinafter abbreviated as “BA”.
Methacrylic acid: Mitsubishi Rayon Co., Ltd., hereinafter abbreviated as “MAA”.
Itaconic acid: manufactured by Iwata Chemical Industry Co., Ltd., hereinafter abbreviated as “IA”.

[Polymerizable monomer having at least one carbonyl group based on keto group or aldehyde group in the molecule]
N- (1,1-dimethyl-3-oxobutyl) acrylamide: Nippon Kasei Co., Ltd .: diacetone acrylamide, hereinafter abbreviated as “DAAm”.

[Multivalent hydrazide compound]
Adipic acid dihydrazide: manufactured by Otsuka Chemical Co., Ltd .: hereinafter abbreviated as “ADH”.
[Radical polymerization initiator]
Potassium persulfate: manufactured by ADEKA Corporation, hereinafter abbreviated as “KPS”.
・ Anhydrous sodium bisulfite… (Yes) Togawa Chemical Industry, hereinafter abbreviated as “SBS”.

[emulsifier]
Emulgen 1135S-70: manufactured by Kao Corporation, hereinafter abbreviated as “E1135S-70”.
[Anti-blocking agent]
・ Dimethyl silicone oil: manufactured by MOMENTIVE: TSF451-100
[Coagulant]
Polyether-modified silicone oil: manufactured by MOMENTIVE: TPA4380

[Foaming agent]
・ Sulfosuccinic acid N-alkyl monoamido disodium ... Kao Corporation: Perex TA
[Foam stabilizer]
-Ammonium stearate aqueous dispersion: Sannobuco Co., Ltd .: DC-100A

[Pigment]
60% titanium oxide dispersion: Chuo Rika Kogyo Co., Ltd .: T-60
[Curing agent]
Fatty acid polyglycidyl ether: Chuo Rika Kogyo Co., Ltd .: Rikabond EX-8
[Thickener]
・ Alkali thickening acrylic copolymer: manufactured by Chuo Rika Kogyo Co., Ltd .: Rikabond FK-600S
[Fibrous layer]
・ Polyester felt: Made by Daiso Corporation: Polyester felt

[(A) Production of dispersion]
Add and mix the type and amount of (meth) acrylic monomers listed in Table 1 to the types and amounts of urethane resins listed in Table 1 below, then the first stage resin mixture and the second stage The resin mixture was adjusted. Next, as an emulsifier, 3 parts by weight of E1135S-70 is added to the first stage and 2 parts by weight to the second stage, and ion-exchanged water is added so that the solid content of the whole liquid becomes 60% by weight. The first-stage raw material emulsion and the second-stage raw material emulsion were obtained.
Further, water is added to a reaction vessel having a volume of 2 liters having a stirring blade so that the solid content of the emulsion after emulsion polymerization is 47% by weight, and then the stirring blade of this reaction vessel is rotated at 60 rpm and stirred. The temperature was raised to 60 ° C.
First, the first stage raw material emulsion was continuously dropped over 3 hours. Subsequently, after completion of the dropping of the first stage raw material emulsion, the second stage raw material emulsion was dropped over 1 hour and a half, and then the temperature was maintained for 2 hours to complete the polymerization. . Thereafter, 1.08 parts by weight of ADH (25.7% by weight based on DAAm) was added and mixed as a polyhydric hydrazide compound.
Said various measurement was performed about the obtained urethane- (meth) acrylic-type composite resin aqueous dispersion. The results are shown in Table 1.

[(B) Dispersion]
-Rikabond FK-474 ... manufactured by Chuo Rika Kogyo Co., Ltd., (meth) acrylic emulsion, Tg: -26 ° C, solid content: 55.0%, hereinafter referred to as "FK-474".
-Rikabond FK-455 ... manufactured by Chuo Rika Kogyo Co., Ltd., (meth) acrylic emulsion, Tg: -36 ° C, solid content: 45.0%, hereinafter referred to as "FK-455".
-Rikabond ES-90: manufactured by Chuo Rika Kogyo Co., Ltd., (meth) acrylic emulsion, Tg: 92 ° C., solid content 51.0%, hereinafter referred to as “ES-90”.
-Rikabond CS-10 ... manufactured by Chuo Rika Kogyo Co., Ltd., (meth) acrylic emulsion, Tg: -63 ° C, solid content: 60.0%, hereinafter referred to as "CS-10".

(Examples 1-11, Comparative Examples 1-2)
A composite resin aqueous dispersion was prepared by mixing (A) dispersion and (B) dispersion of the type described in Table 2 or 3 below at a weight ratio (solid content) described in Table 2 or 3.
Using the resulting composite resin aqueous dispersion, a predetermined amount of the above compounding agent was added to prepare an artificial leather coating solution. The coating solution was subjected to the various measurements and evaluations described above. The results are shown in Table 2 or 3.

Claims (6)

It has at least two types of aqueous dispersions of the following (A) dispersion and (B) dispersion, and the weight ratio (in terms of solid content) is (A) / (B) = 94/6 to 4 / 96 composite resin aqueous dispersion.
(A) Dispersion: A raw material emulsion in which one or more (meth) acrylic monomers are dispersed in advance is added sequentially or continuously into a reaction vessel in the presence of an aqueous medium, An aqueous dispersion obtained by emulsion polymerization of the one or more (meth) acrylic monomers in the presence of a urethane resin,
As the raw material emulsion, at least two kinds of raw material emulsions having different compositions are used, and after the addition of one raw material emulsion, the addition of the next raw material emulsion is started, and the raw material emulsion Of these, an aqueous urethane- (meth) acrylic resin dispersion containing a urethane resin as a raw material emulsion to be initially added to the reaction vessel.
(B) Dispersion liquid: (meth) obtained by polymerizing the (meth) acrylic monomer constituting (A) above with the same or different kind of (meth) acrylic monomer in an aqueous medium Acrylic resin aqueous dispersion.   2. The composite resin aqueous solution according to claim 1, wherein the weight ratio of the urethane resin component and the acrylic resin component in the dispersion (A) is urethane resin component / acrylic resin component = 5/95 to 85/15. Dispersion. From the glass transition temperature Tg _A of the polymer obtained from the (meth) acrylic monomer composition constituting the (A) dispersion, and from the (meth) acrylic monomer composition constituting the (B) dispersion. The composite resin according to claim 1 or 2, wherein a composite glass transition temperature (Tg _total ) obtained by adding together the glass transition temperature Tg _B of the obtained polymer according to the following formula <1> is -15 ° C or higher and 25 ° C or lower. Aqueous dispersion.
1 / Tg _total = W _A / Tg _A + W _B / Tg _B <1>
(In the formula <1>, W _A is, (A) dispersion and (B) to the total (meth) acrylic monomer constituting the dispersion, (A) (meth) acrylic dispersion shows the monomer content, W _B is, (a) dispersion and (B) to the total (meth) acrylic monomer constituting the dispersion, (B) dispersion liquid of (meth) acrylic monomer Indicates the content ratio of the monomer.   A coating resin dispersion comprising the aqueous composite resin dispersion according to any one of claims 1 to 3.   A laminate comprising a coating layer formed from the coating resin dispersion according to claim 4 and a base material layer.   A skin layer is formed on the surface of the laminate according to claim 5, and the coating layer is disposed between the skin layer and the base material layer, and the coating layer is for artificial leather constituting a foam layer. Laminated body.

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