JP2013001891A - Foamable resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an aqueous dispersion liquid of a urethane-(meth)acrylate composite resin, which liquid can allow artificial leather obtained therefrom to have satisfactory strength and bending properties and excellent hydrolyzing resistance.SOLUTION: The urethane-(meth)acrylate composite resin is obtained by adding at least two emulsified liquids, which are raw materials, in each of which one or a plurality of (meth)acrylate monomers are dispersed beforehand and which have the compositions different from each other, to a reaction vessel successively or continuously in the presence of an aqueous medium in such a manner that one emulsified liquid is added first and the other emulsified liquid is added thereafter. A foamable resin composition is obtained by incorporating a foaming agent and a foam stabilizer in the urethane-(meth)acrylate composite resin.

Description

  The present invention relates to a foamable resin composition containing a composite resin composed of a urethane resin and a (meth) acrylic composite resin.

  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]).

  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 used for artificial leather, but urethane resin is difficult to achieve both durability and hydrolysis resistance and flexibility, and due to cost problems, these urethane resins are used in artificial leather. It has been studied to improve the drawbacks and 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.

  Accordingly, the present invention provides an urethane- (meth) acrylic composite resin aqueous dispersion having sufficient strength and flexibility and excellent hydrolysis resistance when used as an artificial leather, and further the resin. It aims at obtaining the composition for artificial leather which can fully exhibit the effect of.

The present invention relates to a foaming agent of 0.05 to 7 parts by weight and a foam stabilizer per 100 parts by weight of a urethane- (meth) acrylic composite resin obtained from the following urethane- (meth) acrylic composite resin aqueous dispersion. By using a foamable resin composition containing 0.5 to 6 parts by weight, the above problem has been solved.
-Urethane- (meth) acrylic composite resin aqueous dispersion:
In the presence of a urethane resin, 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 one or more kinds of (meth) acrylic monomers, wherein the emulsion polymerization is at least two types having different compositions as the raw material emulsion. After the addition of one raw material emulsion is completed using the raw material emulsion, the addition of the next raw material emulsion is started, and among the raw material emulsions, the raw material emulsion first added to the reaction vessel As an aqueous dispersion of urethane- (meth) acrylic composite resin obtained by using a resin containing a urethane resin.

  According to this invention, since a specific urethane- (meth) acrylic composite resin, foaming agent, and foam stabilizer are used, when used as an artificial leather, it has sufficient strength and flexibility and is resistant to hydrolysis. A composite resin having excellent properties 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 foamable resin composition according to the present invention contains a foaming agent and a foam stabilizer in a urethane- (meth) acrylic composite resin obtained from a predetermined urethane- (meth) acrylic composite resin aqueous dispersion. It is a resin composition. In the present invention, “(meth) acryl” means “acryl or methacryl”.

[Urethane- (meth) acrylic composite resin aqueous dispersion]
The above urethane- (meth) acrylic composite resin aqueous dispersion is prepared by sequentially mixing a raw material emulsion in which one or more (meth) acrylic monomers are dispersed in advance into a reaction vessel in the presence of an aqueous medium. It is an aqueous dispersion obtained by emulsion polymerization of the one or more (meth) acrylic monomers in the presence of a urethane resin by adding them continuously or continuously.

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 420, Superflex 500M, Made by Adeka: Adekabon titer UHX-210, Adekabon titer UHX-280, Sumika Bayer Urethane Co., Ltd. Manufactured by: DISPARALL U53, DISPARALL 54, disparity 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 carboxyl group-containing diols such as polybutadiene diol, polyacrylate diol, dimethylolpropionic acid, and dimethylolbutanoic acid.

  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, emulsion polymerization, which is a polymerization reaction for obtaining an aqueous urethane- (meth) acrylic composite resin dispersion, will be described.
As described above, the urethane- (meth) acrylic composite resin aqueous dispersion is added 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. Thus, it can be obtained by emulsion polymerization of the one or more (meth) acrylic monomers.

  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. In this way, a film having both flexibility and toughness when the obtained urethane- (meth) acrylic composite resin aqueous dispersion is used for artificial leather by sequentially adding a plurality of raw material emulsions. Can be formed.

In the case where the plurality of raw material emulsions are sequentially added, the glass transition temperature (Tg _A1 ) of the polymer obtained from the (meth) acrylic monomer composition in one raw material emulsion, and the following The glass transition temperature (Tg _A2 ) of the polymer obtained from the (meth) acrylic monomer composition in the raw emulsion is preferably a temperature at which Tg _A2 is higher than Tg _A1 , and the difference (Tg _A2 − Tg _A1 ) is preferably 10 ° C. or higher, and more preferably 30 ° C. or higher. When the temperature is lower than 10 ° C., the effect obtained by dividing and adding to a plurality of raw material emulsions may not be sufficiently obtained. On the other hand, the upper limit of the difference is preferably 150 ° C, more preferably 100 ° C. When the temperature is higher than 150 ° C., the resulting film becomes hard, and there is a tendency for flexibility to be insufficient for artificial leather.

  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 urethane- (meth) acrylic composite resin, 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.

  The obtained urethane- (meth) acrylic composite resin preferably has a functional group capable of reacting with a curing agent described later. Examples of such a functional group include a carboxyl group,.

  As described above, the carboxyl group of the urethane- (meth) acrylic composite resin is a (meth) acrylic single monomer having a carboxyl group in the side chain used as a monomer constituting the (meth) acrylic composite resin. It is derived from a diol having a carboxyl group used as a diol constituting a body or a urethane resin.

[Homopolymer of (meth) acrylic monomer]
If necessary, the urethane- (meth) acrylic composite resin aqueous dispersion may contain a homopolymer of a (meth) acrylic monomer. Examples of the (meth) acrylic monomer include the same (meth) acrylic monomers as described above.

  The (meth) acrylic monomer homopolymer is obtained by polymerizing one kind of (meth) acrylic monomer in an aqueous medium. As this polymerization method, an emulsion polymerization method used for producing the above-mentioned dispersion (A) can be employed. As this aqueous medium, the same aqueous medium as described above can be used.

  The mixing ratio (weight ratio) of the urethane- (meth) acrylic composite resin and the (meth) acrylic monomer homopolymer is urethane- (meth) acrylic composite resin / (meth) acrylic single The monomer homopolymer is 94/6 or less, preferably 90/10 or less. If it is larger than 94/6, there may be a problem that the effect based on the (meth) acrylic monomer homopolymer cannot be obtained. On the other hand, the lower limit of the mixing ratio is preferably 4/96, and more preferably 5/95. If the ratio is smaller than 4/96, there may be a problem that effects such as compatibility of flexibility and prevention of stickiness cannot be obtained based on the urethane- (meth) acrylic composite resin.

  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.

[Foaming resin composition]
The foamable resin composition according to the present invention includes, as described above, a urethane- (meth) acrylic composite resin obtained from the urethane- (meth) acrylic composite resin aqueous dispersion, and (meth) acrylic as necessary. It is a resin composition containing a foaming agent and a foam stabilizer in a mixed resin obtained by mixing a homopolymer of a system monomer.

  The foaming agent is an agent for causing the resin composition to foam, and the foam stabilizer is an agent for retaining the generated bubbles.

  Examples of the foaming agent include an anionic surfactant and the like, a chemical foaming agent such as sodium hydrogen carbonate and azodicarbonamide, and the like which are mechanically foamed by stirring and the like. Examples of the anionic surfactants include sulfates such as alkyl sulfates, polyoxyethylene alkyl ether sulfates, polyoxyalkylene alkenyl ether sulfates, sulfonates such as alkylbenzene sulfonates, potassium oleates, and the like. Fatty acid alkali metal salts such as soap, castor oil potassium soap, sodium stearate soap, polyoxyethylene alkyl ether potassium phosphate, alkenyl succinate dipotassium, high molecular surfactants such as special polycarboxylic acid type polymeric surfactants, etc. Can be given.

  Examples of the foam stabilizer include higher fatty acid alkali metal salts.

  The content of the foaming agent is required to be 0.05 parts by weight or more and preferably 0.06 parts by weight or more per 100 parts by weight of the urethane- (meth) acrylic composite resin. When the amount is less than 0.05 parts by weight, the foaming effect cannot be obtained sufficiently. On the other hand, the upper limit of the content is 7 parts by weight, preferably 6.5 parts by weight. When it is more than 7 parts by weight, the water resistance becomes insufficient.

  The content of the foam stabilizer should be 0.5 parts by weight or more per 100 parts by weight of the urethane- (meth) acrylic composite resin, and preferably 0.6 parts by weight or more. When the amount is less than 0.5 part by weight, the effect is not sufficiently obtained, and cell roughness of the foam occurs. On the other hand, the upper limit of the content is 6 parts by weight, preferably 6.5 parts by weight. When the amount is more than 6 parts by weight, the strength when formed into a film is lowered.

  The foamable resin composition according to the present invention may further contain a curing agent. By adding this hardening | curing agent, resin which comprises a foamable resin composition can be bridge | crosslinked, and intensity | strength can be improved more.

  As this hardening | curing agent, the agent which has 2 or more of functional groups which can react with the functional group in the said urethane- (meth) acrylic-type composite resin in 1 molecule is used. When the functional group in the urethane- (meth) acrylic composite resin is a carboxyl group, specific examples of the curing agent used include an epoxy compound and an oxazoline compound.

  The amount of the curing agent used is preferably 1 part by weight or more and preferably 2 parts by weight or more with respect to 100 parts by weight of the urethane- (meth) acrylic composite resin. If the amount is less than 1 part by weight, the effect may not be sufficiently obtained. On the other hand, the upper limit of the content is preferably 10 parts by weight, and preferably 4 parts by weight. If it is more than 10 parts by weight, the uncured curing agent may remain and cause coating film defects.

  The viscosity of the foamable resin composition according to the present invention is preferably 5,000 mPa · s or more and 6000 mPa · s or more under the conditions measured at 12 rpm using a B-type viscometer (# 4 rotor) at 25 ° C. preferable. When it is less than 5,000 mPa · s, the permeability to the base fabric is increased, the uniformity of the foamed layer may be insufficient, or the texture of the film may be deteriorated. On the other hand, the upper limit of the viscosity is preferably 50,000 mPa · s, and preferably 45,000 mPa · s. When it is larger than 50,000 mPa · s, workability tends to deteriorate.

  By the way, the viscosity of the foamable resin composition according to the present invention may be higher or lower than the intended purpose. In this case, a viscosity modifier may be added to the foamable resin composition to adjust the viscosity. However, the viscosity after adding the viscosity modifier preferably satisfies the above viscosity range under the above conditions.

  The film formed from the foamable resin composition 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 foamable resin composition 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 foamable resin composition 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 foamable resin composition 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 foamable resin composition according to the present invention can be laminated on a base material layer to obtain a laminate in which a foam layer is formed on the surface of the base material layer.

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 spinning such as 6-nylon, 6,6-nylon and other melt-spinnable polyamides, polyethylene terephthalate, polybutylene terephthalate, and cation 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.

  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.

  Since the composite resin aqueous dispersion according to the present invention uses a urethane- (meth) acrylic composite resin obtained from the urethane- (meth) acrylic composite resin aqueous dispersion as described above, the maximum elongation, peel strength, etc. Strength can be improved, surface tack is small, and durability can be improved.

  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 resin is set to Wa, Wb,..., And the glass transition temperature of the homopolymer of each constituent unit a, b,. When Tga, Tgb, and so on, 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.

[viscosity]
About 400 g of foamable resin composition before foaming is put into a 500 ml polyethylene bottle, covered, and left in a thermostatic bath at 25 ° C. for 3 hours. When the temperature reaches 25 ° C., a B-type viscometer Viscosity was measured with (TOKI SANGYO Co., TV-10M type, # 4 rotor, 12 rpm).

[specific gravity]
It measured according to the description of JIS K 5600-2-4.

[Create specimen]
Each foamable resin composition that was foamed was collected to a solid content of 100 parts by weight, and a coating solution prepared with the following composition was applied to the polyester felt of the fibrous layer to a thickness of 1 mm, The coating film was dried with a drier 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]
TSF451-100 ... dimethylsilicone oil (manufactured by MOMENTIVE: TSF451-100)
[Coagulant]
-TPA4380: Polyether-modified silicone oil (manufactured by MOMENTIVE: TPA4380)

[Foaming agent]
・ Perex TA: N-alkylmonoamide disodium sulfosuccinate (manufactured by Kao Corporation: Perex TA)
・ Emar 2FG: Sodium lauryl sulfate (manufactured by Kao Corporation: Emar 2FG)
・ Emar D3D: Sodium polyoxyethylene alkyl ether sulfate (manufactured by Kao Corporation: Emar D3D)
FR-14: Potassium soap oleate (manufactured by Kao Corporation: FR-14)
FR-25 ... castor oil potash soap (manufactured by Kao Corporation: FR-25)

[Foam stabilizer]
DC-100A: ammonium stearate aqueous dispersion (manufactured by San Nopco Co., Ltd .: DC-100A)

[Pigment]
T-60 ... 60% titanium oxide dispersion (Chuo Rika Kogyo Co., Ltd .: T-60)
[Water-soluble resin]
10% RS-2117: 10% aqueous solution of a highly crystalline polyvinyl alcohol polymer (manufactured by Kuraray Co., Ltd .: EXEVAL RS-2117) [curing agent]
-EX-8 ... fatty acid polyglycidyl ether (Chuo Rika Kogyo Co., Ltd .: Rikabond EX-8)
・ Zinc oxide: Zinc oxide (Kishida Chemical Co., Ltd .: zinc oxide)
Baycoat 20: ammonium zirconium carbonate (Nippon Light Metal Co., Ltd .: Baycoat 20)
・ 2030E: Oxazoline group-containing polymer (manufactured by Nippon Shokubai Co., Ltd .: Epocross K-2030E)
BA-11B: aliphatic polyisocyanate (Chuo Rika Kogyo Co., Ltd .: Rikabond BA-11B)
[Thickener]
-FK-600S ... alkali thickening acrylic copolymer (Chuo Rika Kogyo Co., Ltd .: Rikabond FK-600S)
UH-752: Polyether polyol urethane polymer (manufactured by ADEKA: Adecanol UH-752)
[Base material layer]
・ Polyester felt: Made by Daiso Corporation: Polyester felt

[Production of aqueous dispersion of urethane- (meth) acrylic composite resin]
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.

[(Meth) acrylic acid monomer homopolymer]
・ Rikabond FK-474 ... made 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: -4.4 ° 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)

(Examples 1-29, Comparative Examples 1-3)
Each component described in Tables 2 to 6 below was mixed in the amounts described to obtain a foamable resin composition. Next, it was mechanically foamed with a hand mixer, and various measurements and evaluations were performed using this. The results are shown in Tables 2-6.

Claims (9)

Foaming agent 0.05 to 7 parts by weight and foam stabilizer 0.5 to 100 parts by weight of urethane- (meth) acrylic composite resin obtained from the following urethane- (meth) acrylic composite resin aqueous dispersion A foamable resin composition comprising 6 parts by weight.
-Urethane- (meth) acrylic composite resin aqueous dispersion:
In the presence of a urethane resin, 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 one or more (meth) acrylic monomers,
The emulsion polymerization is
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 composite resin dispersion obtained by using a material containing a urethane resin as the raw material emulsion to be initially added to the reaction vessel.   Furthermore, it contains a homopolymer of a (meth) acrylic monomer, and the weight ratio of the urethane- (meth) acrylic composite resin to the (meth) acrylic monomer homopolymer is urethane- The foamable resin composition according to claim 1, which is a (meth) acrylic composite resin / (meth) acrylic monomer homopolymer and is 94/6 to 4/96.   Furthermore, a curing agent having two or more functional groups capable of reacting with the functional group in the urethane- (meth) acrylic composite resin in one molecule is added to 100 parts by weight of the urethane- (meth) acrylic composite resin. The foamable resin composition according to claim 1 or 2, which contains 1 to 10 parts by weight.   The foamable resin composition according to claim 3, wherein the functional group in the urethane- (meth) acrylic composite resin is a carboxyl group.   The foamable resin composition according to claim 3 or 4, wherein the curing agent is an epoxy compound and / or an oxazoline compound.   The foaming property according to any one of claims 1 to 5, wherein a viscosity measured at 12 rpm using a B-type viscometer (# 4 rotor) at 5,000C is 5,000 mPa · s to 50,000 mPa · s. Resin composition.   The foamable resin composition according to claim 6, further comprising a viscosity modifier, wherein the viscosity is adjusted to 5,000 mPa · s to 50,000 mPa · s by the viscosity modifier.   It is a laminated body which has a foaming layer and a base material layer, This foaming layer is a laminated body formed from the foamable resin composition of any one of Claims 1 thru | or 7.   An artificial leather comprising the laminate according to claim 8.

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