JP2009013334A - Resin aqueous dispersion and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin aqueous dispersion including a thermoplastic elastomer conventionally not provided as a stable aqueous dispersion. <P>SOLUTION: This resin aqueous dispersion includes (A) a polyolefin resin including an unsaturated carboxylic acid component by 1.5-10 mass%, and (B) the thermoplastic elastomer having the content of the unsaturated carboxylic acid component by less than 1.5 mass%. In the resin aqueous dispersion, the content of a nonvolatile hydrophilizing assistant is set to 0.1 mass part or less to the total quantity of 100 mass part of (A) and (B). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an aqueous resin dispersion containing a polyolefin resin and a thermoplastic elastomer, and a method for producing them.

  Olefin-based thermoplastic elastomers (hereinafter TPO) are excellent in moldability, cold resistance, electrical insulation and mechanical properties, are relatively inexpensive, and have countermeasures for environmental issues. It is being used in the field of goods. However, TPO base materials are inferior in adhesion to the same base materials or different types of base materials such as metals, and their use has been restricted, which has prevented their spread.

  As an adhesive suitable for a TPO substrate, Patent Document 1 proposes the use of an adhesive mainly composed of a thermoplastic elastomer. However, this adhesive uses a thermoplastic elastomer or the like dissolved in a solvent such as toluene, and has a large problem with respect to the environment and the work environment.

  In recent years, the use of water-based adhesives (aqueous dispersions) with little environmental impact has been promoted against such solvent-based adhesives, and aqueous dispersions of thermoplastic elastomers are also disclosed in Patent Documents 2 to 4, etc. Many are known. However, it is essential to add a non-volatile aqueous additive such as a surfactant during production, which greatly affects the performance of the aqueous dispersion and causes deterioration of water resistance and adhesion to TPO substrates. As a result, there is still room for improvement.

  On the other hand, Patent Document 5 discloses a method in which a low acid value polyolefin resin is aqueous-dispersed without adding a non-volatile aqueous additive. However, even when an aqueous resin dispersion obtained by this method is used, there is still room for improvement in the adhesion performance to the TPO substrate.

JP-A-6-106682 Japanese Patent Publication No.55-8020 JP 2005-2448035 A JP 2006-206777 A JP 2003-119328 A

  The present invention intends to provide an aqueous resin dispersion exhibiting good adhesion to a TPO base material for the above problems.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the content of the unsaturated carboxylic acid component is 1.5 to 10% by mass and the unsaturated carboxylic acid component is 1. An aqueous resin dispersion containing less than 5% by mass of a thermoplastic elastomer (B) and having a reduced content of the nonvolatile aqueous auxiliary agent has been found, and the present invention has been achieved.

That is, the gist of the present invention is as follows.
(1) A polyolefin resin (A) containing an unsaturated carboxylic acid component in an amount of 1.5 to 10% by mass and a thermoplastic elastomer (B) having an unsaturated carboxylic acid component content of less than 1.5% by mass. An aqueous resin dispersion, wherein the content of the nonvolatile aqueous auxiliary agent is 0.1 parts by mass or less with respect to 100 parts by mass of the total amount of (A) and (B). body.
(2) The mass ratio (A) / (B) between the polyolefin resin (A) and the thermoplastic elastomer (B) is 99.5 / 0.5 to 50/50, Resin aqueous dispersion.
(3) The aqueous resin dispersion according to (1) or (2), wherein the thermoplastic elastomer (B) is a styrene-based thermoplastic elastomer or an olefin-based thermoplastic elastomer.
(4) A polyolefin resin (A) containing 1.5 to 10% by mass of an unsaturated carboxylic acid component and a thermoplastic elastomer (B) having an unsaturated carboxylic acid component content of less than 1.5% by mass are kneaded. Any one of (1) to (3), comprising a step (I) for obtaining a mixed resin (C) and an aqueous dispersion step (II) for dispersing the mixed resin (C) in an aqueous medium A method for producing the aqueous resin dispersion according to 1.
(5) The method for producing an aqueous resin dispersion according to (4), wherein the kneading method in step (I) is melt kneading.

  The aqueous resin dispersion of the present invention is excellent in wettability, adhesion and adhesiveness when coated on a TPO substrate. Furthermore, according to the production method of the present invention, a thermoplastic elastomer-containing aqueous dispersion, which has been conventionally obtained only by adding a non-volatile water-immobilizing aid, can be obtained without adding a non-volatile water-making aid. However, it can be easily obtained.

  Hereinafter, the present invention will be described in detail.

  The polyolefin resin (A) used in the present invention is a resin mainly composed of an olefin having 2 to 6 carbon atoms such as ethylene, propylene, isobutylene, 1-butene, 1-pentene and 1-hexene, and these monomers Two or more of these may be used. Among these, olefins having 2 to 4 carbon atoms such as ethylene, propylene, isobutylene and 1-butene are more preferable, and ethylene and propylene are particularly preferable.

  The polyolefin resin (A) contains an unsaturated carboxylic acid component in an amount of 1.5 to 10% by mass, preferably 1.5 to 8% by mass, more preferably 2 to 7% by mass. If the unsaturated carboxylic acid component is less than 1.5% by weight, aqueous dispersion is difficult, and if it exceeds 10% by weight, aqueous dispersion becomes easier, but the polarity of the coating film obtained from the aqueous dispersion is high. Therefore, the adhesion to a substrate with low polarity tends to be lowered.

  The unsaturated carboxylic acid component is a compound having at least one carboxyl group or acid anhydride group in the molecule, that is, in the monomer component, and specifically includes acrylic acid, methacrylic acid, maleic acid, maleic anhydride. In addition to itaconic acid, itaconic anhydride, fumaric acid, crotonic acid, and the like, unsaturated dicarboxylic acid half esters, half amides and the like can be mentioned. Of these, acrylic acid, methacrylic acid, maleic acid, and maleic anhydride are preferable, and acrylic acid and maleic anhydride are particularly preferable. Moreover, the unsaturated carboxylic acid component should just be copolymerized in polyolefin resin, The form is not limited, For example, random copolymerization, block copolymerization, graft copolymerization etc. are mentioned.

  In the polyolefin resin (A), monomers other than the olefin component and the unsaturated carboxylic acid component may be copolymerized. Examples of such monomers include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, and lauryl (meth) acrylate. Vinyl ethers such as (meth) acrylic acid esters, methyl vinyl ether and ethyl vinyl ether; vinyl esters such as vinyl acetate and vinyl propionate; dienes; (meth) acrylonitrile; vinyl halides; vinylidene halides; Carbon; sulfur dioxide. ("(Meth) acrylic acid ~" means "acrylic acid ~ or methacrylic acid ~".)

  Specific examples of the polyolefin resin (A) include ethylene-acrylic acid ester-maleic anhydride copolymer, ethylene-propylene-maleic anhydride copolymer, ethylene-butene-maleic anhydride copolymer, propylene-butene- Maleic anhydride copolymer, ethylene-propylene-butene-maleic anhydride copolymer, ethylene-propylene-acrylic ester-maleic anhydride copolymer, ethylene-butene-acrylic ester-maleic anhydride copolymer, Examples include propylene-butene-acrylic acid ester-maleic anhydride copolymer, ethylene-propylene-butene-acrylic acid ester-maleic anhydride copolymer, and the like.

  The polyolefin resin (A) preferably has a melt flow rate of 0.01 to 500 g / 10 min at 190 ° C. and a load of 2160 g, which is a measure of molecular weight, more preferably 0.1 to 400 g / 10 min, and 1 to 300 g. / 10 minutes is more preferable, and 5 to 200 g / 10 minutes is particularly preferable. When the melt flow rate of the polyolefin resin (A) is less than 0.01 g / 10 min, it may be difficult to make the resin water-based or heat sealability may be deteriorated. On the other hand, when the melt flow rate of the polyolefin resin (A) exceeds 500 g / 10 minutes, the resulting coating film tends to be hard and brittle, and the heat sealability tends to be lowered.

  Examples of the thermoplastic elastomer (B) used in the present invention include styrene thermoplastic elastomer, olefin thermoplastic elastomer, ester thermoplastic elastomer, diene thermoplastic elastomer, vinyl chloride thermoplastic elastomer, chlorinated ethylene. Based thermoplastic elastomer, urethane based thermoplastic elastomer, polyamide based thermoplastic elastomer, and the like. These thermoplastic elastomers may be used individually by 1 type, and may be used in combination of 2 or more type. Of these, styrene-based thermoplastic elastomers or olefin-based thermoplastic elastomers are preferable from the viewpoint of adhesion performance to the TPO substrate.

  The styrenic thermoplastic elastomer used in the present invention includes an aromatic vinyl polymer block (hard segment) mainly composed of an aromatic vinyl compound and a conjugated diene polymer block mainly composed of a conjugated diene compound (soft segment). And a random copolymer of an aromatic vinyl compound and a conjugated diene compound are preferable.

  Examples of the aromatic vinyl compound include styrene; α-alkyl-substituted styrene such as α-methylstyrene, α-ethylstyrene, α-methyl-p-methylstyrene; o-methylstyrene, m-methylstyrene, p- Nuclear alkyl-substituted styrenes such as methylstyrene, 2,4-dimethylstyrene, ethylstyrene, 2,4,6-trimethylstyrene, ot-butylstyrene, pt-butylstyrene, p-cyclohexylstyrene; o-chloro Nuclear halogenated styrene such as styrene, m-chlorostyrene, p-chlorostyrene, p-bromostyrene, 2-methyl-4-chlorostyrene; vinylnaphthalene derivatives such as 1-vinylnaphthalene; indene derivatives; divinylbenzene and the like It is done. Among these, styrene, α-methylstyrene and p-methylstyrene are preferable, and styrene is particularly preferable. These aromatic vinyl compounds may be used individually by 1 type, and may be used in combination of 2 or more type.

  Examples of the conjugated diene compound include butadiene, isoprene, piperylene, methylpentadiene, phenylbutadiene, 3,4-dimethyl-1,3-hexadiene, 4,5-diethyl-1,3-octadiene, and the like. Among these, butadiene and / or isoprene are preferable. These conjugated diene compounds may be used alone or in combination of two or more.

  Styrenic thermoplastic elastomers are styrene-butadiene block copolymers and their hydrogenated products, styrene-butadiene random copolymers and their hydrogenated products, styrene-isoprene block copolymers and their hydrogenated products, styrene-isoprene random products. A copolymer and a hydrogenated product thereof, specifically, a styrene-butadiene-styrene block copolymer (SBS), a styrene-isoprene-styrene block copolymer (SIS), a styrene-isobutylene-styrene block copolymer. Polymer (SIBS), Styrene-ethylene / butylene-styrene block copolymer (SEBS), Styrene-ethylene / butylene-olefin crystal block copolymer (SEBC), Styrene-ethylene / propylene-styrene block copolymer (S PS), hydrogenated styrene-butadiene random copolymer (HSBR), crystalline polyethylene obtained by hydrogenation of block copolymer of polybutadiene and butadiene-styrene random copolymer, and ethylene / butylene-styrene random A block copolymer with a copolymer, a diblock copolymer of crystalline polyethylene and polystyrene, and the like obtained by hydrogenating a block copolymer of polybutadiene or an ethylene-butadiene random copolymer and polystyrene are listed. It is done. The content of the styrene block in these styrenic elastomers is preferably 5 to 60% by mass, more preferably 10 to 50% by mass, and particularly preferably 15 to 40% by mass.

  The melt flow rate (230 ° C., 2.16 kg) of the styrenic thermoplastic elastomer as described above is preferably 0.1 to 200 g / 10 minutes, and more preferably 0.5 to 100 g / 10 minutes. If it is less than 0.1 g / 10 minutes, the compatibility tends to deteriorate when it is melt-kneaded with polyolefin, and if it exceeds 200 g / 10 minutes, the adhesiveness in the case of an aqueous dispersion tends to decrease.

  Examples of the styrenic thermoplastic elastomer include “Dynalon, TR, SIS” of JSR Corporation, “Clayton D, Kraton G, Clayton FG” of Clayton Polymer Japan Co., Ltd., Asahi Kasei Corporation. “Tuftex, Tufplen, Asaprene”, “Elastomer AR” from Aronkasei Co., Ltd., “Thermo Run” from Mitsubishi Chemical Corporation, “Septon” from Kuraray Co., Ltd., etc. are commercially available.

  The olefinic thermoplastic elastomer used in the present invention includes (1) a crystalline polyolefin and an amorphous olefinic copolymer rubber or a mixture of rubber components, and (2) a crystalline polyolefin block (A) and an amorphous. Block copolymer having at least one rubber block (B) in the molecule, (3) Atactic polypropylene as a soft segment added to isotactic polypropylene as a hard segment, (4) ethylene / Propylene / butene copolymer, (5) Monoethylene such as polyethylene / polypropylene as a hard segment, ethylene / propylene non-conjugated diene terpolymer rubber with a soft segment partially cross-linked to a crystalline material such as polymethylpentene Olefin copolymer rubber, (6) Hardset Olefin-based copolymer (crystalline) as a mentament and uncrosslinked monoolefin copolymer rubber as a soft segment while being subjected to shear stress while heating, or (7) peroxide decomposition / Olefin copolymer rubber, which is a peroxide-crosslinked monoolefin polymer, using isotactic polypropylene, propylene / ethylene copolymer, or propylene / butene-1 copolymer as a hard segment. Or a soft segment made of ethylene / propylene / non-conjugated diene terpolymer rubber or the like. Among them, preferred are (1) crystalline polyolefin and amorphous olefin copolymer rubber or a mixture of rubber components, and (2) crystalline polyolefin block (A) and amorphous rubber block ( A block copolymer having at least one B) in each molecule.

  The crystalline polyolefin in the above (1) is an α-olefin homopolymer such as ethylene, propylene, butene-1, hexene-1, 4-methyl-pentene-1, and at least one of ethylene and propylene or another α-olefin. And non-elastomeric copolymers, homopolymers, or a mixture of a homopolymer and a copolymer. Examples of the olefin copolymer rubber include ethylene / propylene copolymer rubber (EPM), ethylene / 1-butene copolymer rubber (EPM), ethylene / propylene / butene copolymer rubber, ethylene / hexene copolymer, ethylene / heptene. Copolymers, ethylene / octene copolymers, ethylene / 4-methylpentene-1 copolymers, and non-conjugated dienes such as aliphatic dienes such as butene-1,1,4-hexadiene, 5-ethylidene norbornene, 5 -Elastic bodies of copolymers mainly composed of olefins such as ethylene / propylene / non-conjugated diene copolymer rubber (EPDM) using methylnorbornene, 5-vinylnorbornene, dicyclopentadiene, dicyclooctadiene, etc. And those that are fully or partially crosslinked are preferred. As the cross-linking agent, an organic peroxide, a phenol vulcanizing agent, or the like is used.

  These olefin copolymer rubbers may be random copolymers, block copolymers, graft copolymers, or alternating copolymers, and the production method and shape thereof are not particularly limited. Moreover, these olefin copolymer rubbers may be used alone or in combination of two or more.

  In addition to the olefin copolymer rubber, other rubber components include diene rubbers such as styrene-butadiene rubber (SBR), nitrile rubber (NBR), natural rubber (NR), butyl rubber (IIR), SEBS, and the like. Polyisobutylene can be used. These rubber components may be used individually by 1 type, and may be used in combination of 2 or more type.

Wherein (2) has, as its _{structure, (A-B) n 1} , (A-B) n 2 -A, (B-A) n 3 -B (n 1, n 2, n 3 is 1 or more An integer) or a structure in which these are bound by a coupling agent. Among these, a triblock copolymer or a copolymer having a larger number of blocks is preferable.

  Examples of such a copolymer include a copolymer composed of a block A ′ mainly composed of a conjugated diene compound and a block A ′ mainly composed of a conjugated diene compound and having a portion capable of becoming a crystalline polyolefin by a crosslinking treatment. is there. Furthermore, there is a block copolymer in which a part of the block A ′ is replaced with a block C made of a polymer of a vinyl aromatic compound.

  Examples of the conjugated diene compound include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, and 2-methyl-1,3-pentadiene.

  The polymer block B ′ mainly composed of a conjugated diene compound is a block that can become an amorphous polyolefin rubbery polymer block after hydrogenation. For example, if the vinyl bond of polybutadiene (content of 1,2- and 3,4-bonds) is about 25 to 85%, a structure similar to that of a rubber-like ethylene-butene copolymer block is obtained by hydrogenation. The resulting amorphous block.

  The block A ′ having a portion that can become a crystalline polyolefin is, for example, made into an ethylene polymer by hydrogenation if the vinyl bond of polybutadiene (content of 1,2- and 3,4-bonds) is about 25% or less. It becomes a crystalline block showing a similar structure.

  Examples of the block copolymer of the present invention include a block copolymer in which the block A ′ and the block B ′ are represented by A′-B′-A ′.

  Examples of such a block copolymer include a block copolymer of an olefin block that forms a highly crystalline polymer such as polypropylene serving as a hard portion and a monomer copolymer block that exhibits amorphous properties as a soft portion. Specifically, an olefin crystal block polymer such as olefin crystal-ethylene / butylene copolymer-olefin crystal (CEBC), ethylene-ethylene / butylene-ethylene block copolymer, propylene-polyethylene oxide-propylene block copolymer. Examples thereof include a polymer and a propylene-olefin (amorphous) -propylene block copolymer. These may be used individually by 1 type, and may mix and use 2 or more types.

  The melt flow rate (230 ° C., 2.16 kg) of the olefinic thermoplastic elastomer as described above is preferably 0.1 to 200 g / 10 minutes, and more preferably 0.5 to 100 g / 10 minutes. If it is less than 0.1 g / 10 minutes, the compatibility tends to deteriorate when it is melt-kneaded with polyolefin, and if it exceeds 200 g / 10 minutes, the adhesiveness in the case of an aqueous dispersion tends to decrease.

  Examples of the olefinic thermoplastic elastomer include “Milastomer” manufactured by Mitsui Chemicals, Inc., “Thermorun” manufactured by Mitsubishi Chemical, “Sumitomo TPE” manufactured by Sumitomo Chemical, and AES Japan. “Santplane” manufactured by JSR Corporation, “Dynalon” manufactured by JSR Corporation, etc. are commercially available.

  The thermoplastic elastomer (B) used in the present invention is improved in compatibility with the polyolefin resin (A), or when it is obtained as a resin aqueous dispersion, in order to improve adhesion and adhesion to the substrate. Further, a functional group may be partly provided. Examples of the functional group include a carboxyl group, an acid anhydride group, a hydroxyl group, an epoxy group, a halogen atom, an amino group, an isocyanate group, a sulfonyl group, and a sulfonate group. A known method can be used as the modification method.

  The content of the functional group is preferably 10% by mass or less. However, when an unsaturated carboxylic acid component is added, the content must be less than 1.5% by mass. When the content of the unsaturated carboxylic acid component is 1.5% by mass or more, the obtained resin aqueous dispersion tends to aggregate and storage stability tends to be lowered.

  Next, the process (I) for kneading the polyolefin resin (A) and the thermoplastic elastomer (B) to obtain the mixed resin (C) will be described.

  The “kneading” as used in the present invention is not particularly limited as long as the two types of resins (A) and (B) are mixed well, and are dissolved and mixed in an organic solvent in which both resins can be dissolved. Alternatively, they may be mixed by melt kneading. In the former mixing method, a relatively large amount of organic solvent is required, and there are problems such as cost, natural environment, workplace environment, regulations by the Fire Service Act, etc., and the latter melt kneading method which is industrially simple is preferable. .

  In the case of obtaining a mixed resin by dissolving in an organic solvent, two or more kinds of organic solvents may be mixed or heated and stirred in order to enhance the solubility. After dissolution, all or a predetermined amount of the organic solvent is removed from the mixed resin (C) by heating, reduced pressure, or the like, and an aqueous dispersion is obtained according to the aqueous dispersion step (II) described later.

  When melt-kneading, a general extruder can be used, and it is preferable to use a twin-screw extruder for improving the kneading state. The polyolefin resin (A) and the thermoplastic elastomer (B) may be supplied to the extruder by dry blending the two resins in advance from one popper, or each hopper is charged with the respective resin under the popper. It may be used while quantifying with a screw or the like. The melt kneading temperature is preferably equal to or higher than the higher melting point of the polyolefin resin (A) or the thermoplastic elastomer (B). Moreover, it is preferable that an upper limit is 350 degrees C or less, and it is more preferable that it is 300 degrees C or less. When the kneading temperature is lower than the melting point of at least one of the resins, the effect of melt kneading may be reduced. When the temperature exceeds 350 ° C., the resin is oxidized or thermally decomposed, and the physical properties are likely to be lowered.

  When kneading, depending on the purpose, crosslinking agent, compatibilizer, pigment, heat stabilizer, antioxidant, weathering agent, flame retardant, plasticizer, lubricant, mold release agent, antistatic agent, filler, etc. May be added.

  The mass ratio (A) / (B) of the polyolefin resin (A) and the thermoplastic elastomer (B) is preferably in the range of 99.5 / 0.5 to 50/50, and the aqueous dispersion yield is increased. Therefore, the range of 99.5 / 0.5 to 60/40 is more preferable, and the range of 99/1 to 70/30 is more preferable. When the content of the thermoplastic elastomer (B) is less than 0.5% by mass, the effect of improving the adhesion to the olefinic thermoplastic elastomer base material is hardly exhibited, and when it exceeds 50% by mass, the aqueous dispersion It becomes difficult to make it, and the aqueous dispersion yield decreases. The aqueous dispersion yield is preferably at least 30% or more from the viewpoint of evaluating and utilizing the aqueous dispersion.

  Next, the aqueous dispersion step (II) will be described.

  The mixed resin (C) obtained as described above can be dispersed, that is, dispersed in an aqueous medium without adding a non-volatile aqueous additive. In the present invention, the detailed principle that the mixed resin (C) containing the thermoplastic elastomer can be dispersed in water without adding the non-volatile water-immobilizing aid is unknown, but the mixed resin (C) A fine sea-island structure in which a polyolefin resin (A) that can be dispersed in water without adding a non-volatile water-based auxiliary agent is a sea layer, and a thermoplastic elastomer (B) that is difficult to be dispersed in water is an island layer. Therefore, at the time of aqueous dispersion, the polyolefin resin (A) in the sea layer is first dispersed, whereby the thermoplastic elastomer (B) that was subsequently present as an island layer is released from the mixed resin. Thus, it is assumed that an aqueous dispersion of the mixed resin (C) is obtained as a result.

  In the aqueous dispersion step (II) of the present invention, it is not necessary to add non-volatile aqueous auxiliary agents such as emulsifiers, protective colloids and high acid value waxes. In the present invention, the amount of the non-volatile water-immobilizing auxiliary agent is a cause of deteriorating the performance such as water resistance and adhesion performance of the obtained aqueous resin dispersion when the non-volatile aqueous auxiliary agent is added. It is preferable to set it as 0.1 mass part or less with respect to 100 mass parts of total amounts of resin (A) and (B). “Aqueous aid” refers to a drug or compound added for the purpose of promoting aqueousization or stabilizing the aqueous resin dispersion in the production of an aqueous resin dispersion. It means that it does not have a boiling point at pressure, or has a high boiling point (for example, 300 ° C. or higher) at normal pressure.

  Examples of the non-volatile auxiliary agent used in the present invention include an emulsifier, a compound having a protective colloid effect, a high acid value wax, a high acid value acid-modified compound, and a water-soluble polymer.

  Examples of the emulsifier include a cationic emulsifier, an anionic emulsifier, a nonionic emulsifier, and an amphoteric emulsifier. In addition to those generally used for emulsion polymerization, surfactants are also included. For example, anionic emulsifiers include higher alcohol sulfates, higher alkyl sulfonates, higher carboxylates, alkyl benzene sulfonates, polyoxyethylene alkyl sulfate salts, polyoxyethylene alkyl phenyl ether sulfate salts, vinyl sulfosuccinates. Nonionic emulsifiers include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyethylene glycol fatty acid ester, ethylene oxide propylene oxide block copolymer, polyoxyethylene fatty acid amide, ethylene oxide-propylene oxide. Compounds having a polyoxyethylene structure such as copolymers and sorbitan derivatives such as polyoxyethylene sorbitan fatty acid esters And examples of the amphoteric emulsifiers, lauryl betaine, lauryl dimethyl amine oxide, and the like. Compounds having protective colloid action, modified waxes, acid-modified compounds with high acid value, water-soluble polymers include polyvinyl alcohol, carboxyl group-modified polyvinyl alcohol, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, modified starch, polyvinylpyrrolidone Polyacrylic acid and salts thereof, carboxyl group-containing polyethylene wax, carboxyl group-containing polypropylene wax, carboxyl group-containing polyethylene-propylene wax and the like, and acid-modified polyolefin waxes having a number average molecular weight of usually 5000 or less and salts thereof, acrylic acid- Maleic anhydride copolymer and salts thereof, styrene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid copolymer, isobutylene-maleic anhydride male A carboxyl group-containing polymer having an unsaturated carboxylic acid content of 15% by mass or more such as an acid alternating copolymer, a (meth) acrylic acid- (meth) acrylic ester copolymer, and a polyitaconic acid and a salt thereof; Examples thereof include water-soluble acrylic copolymers having amino groups, gelatin, gum arabic, and casein, which are generally used as fine particle dispersion stabilizers.

  As the aqueous dispersion method of the present invention, a method of heating and stirring the mixed resin (C) at a temperature of 80 to 250 ° C. with a basic compound, a water-soluble organic solvent and water is preferable. In addition, an aqueous medium consists of water and a water-soluble organic solvent, and this is also included when a basic compound is water-soluble.

  A basic compound neutralizes the carboxyl group in mixed resin (C), and produces | generates a carboxyl anion. Aggregation between the fine particles is prevented by the electric repulsion between the anions, and stability is imparted to the aqueous resin dispersion. As the basic compound, ammonia or an organic amine compound that volatilizes at the time of forming the coating film is preferable from the viewpoint of water resistance of the coating film, and an organic amine compound having a boiling point of 30 to 250 ° C, more preferably 50 to 200 ° C is particularly preferable. When the boiling point is less than 30 ° C., the rate of volatilization when the resin described later becomes aqueous may increase, and the aqueous formation may not proceed completely. When the boiling point exceeds 250 ° C., it becomes difficult to disperse the organic amine compound from the resin coating film by drying, and the water resistance of the coating film may deteriorate.

  Specific examples of the organic amine compound include triethylamine, N, N-dimethylethanolamine, aminoethanolamine, N-methyl-N, N-diethanolamine, isopropylamine, iminobispropylamine, ethylamine, diethylamine, and 3-ethoxypropylamine. , 3-diethylaminopropylamine, sec-butylamine, propylamine, methylaminopropylamine, 3-methoxypropylamine, monoethanolamine, morpholine, N-methylmorpholine, N-ethylmorpholine and the like. The addition amount of the basic compound is preferably 0.5 to 3.0 times equivalent, more preferably 0.8 to 2.5 times equivalent to the carboxyl group in the polyolefin resin, and 1.01 to 2. A 0-fold equivalent is particularly preferred. If it is less than 0.5 times equivalent, the addition effect of a basic compound is not recognized, and if it exceeds 3.0 times equivalent, the drying time at the time of coating film formation may become long or the resin aqueous dispersion may be colored.

  The water-soluble organic solvent promotes aqueous dispersion of the mixed resin (C) and reduces the dispersed particle size. As the water-soluble organic solvent, those having a solubility in water at 20 ° C. of 10 g / L or more are preferably used, and more preferably 50 g / L or more. The amount of the water-soluble organic solvent to be used is preferably 40% by mass or less, more preferably 1 to 40% by mass, further preferably 2 to 35% by mass, and more preferably 3 to 30% of the total solvent contained in the aqueous resin dispersion. Mass% is particularly preferred. When the amount of the organic solvent exceeds 40% by mass, the viscosity of the obtained aqueous dispersion may become too high, or the stability of the aqueous resin dispersion may be lowered depending on the organic solvent used. The amount of the organic solvent in all the solvents can be appropriately reduced by a stripping operation.

  Specific examples of the water-soluble organic solvent used in the present invention include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec. -Alcohols such as amyl alcohol, tert-amyl alcohol, 1-ethyl-1-propanol, 2-methyl-1-butanol, n-hexanol, cyclohexanol, methyl ethyl ketone, methyl isobutyl ketone, ethyl butyl ketone, cyclohexanone, isophorone, etc. Ketones, ethers such as tetrahydrofuran and dioxane, ethyl acetate, acetic acid-n-propyl, isopropyl acetate, acetic acid-n-butyl, isobutyl acetate, acetic acid-sec-butyl, acetic acid-3 Esters such as methoxybutyl, methyl propionate, ethyl propionate, diethyl carbonate, dimethyl carbonate, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol ethyl ether Glycols such as acetate, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol ethyl ether acetate, propylene glycol, propylene glycol monomethyl ether, propylene glycol monobutyl ether, propylene glycol methyl ether acetate Examples of the conductor include 3-methoxy-3-methylbutanol, 3-methoxybutanol, acetonitrile, dimethylformamide, dimethylacetamide, diacetone alcohol, and ethyl acetoacetate. Among them, those having a boiling point of 30 to 250 ° C. are preferable. 50 to 200 ° C. is particularly preferable. These organic solvents may be used in combination of two or more. When the boiling point of the organic solvent is less than 30 ° C., the rate of volatilization when the resin is emulsified increases, and the efficiency of aqueous dispersion may not be sufficiently increased. An organic solvent having a boiling point exceeding 250 ° C. is difficult to be scattered from the resin coating film by drying, and the water resistance of the coating film may be deteriorated.

  Among the above organic solvents, ethanol, n-propanol, isopropanol, n-butanol, methyl ethyl ketone are highly effective in promoting aqueous dispersion of the mixed resin (C) and are easy to remove the organic solvent from the aqueous medium. , Cyclohexanone, tetrahydrofuran, dioxane, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, and ethylene glycol monobutyl ether are preferable, and ethanol, n-propanol, and isopropanol are particularly preferable from the viewpoint of low-temperature drying property.

  The shape of the mixed resin (C) used in the aqueous dispersion step (II) in the present invention is not particularly limited, but from the viewpoint of increasing the aqueousization rate, it is a granular or powdery form having a particle diameter of 1 cm or less, preferably 0.8 cm or less. It is preferable to use those.

  The addition amount of the mixed resin (C) is preferably 1 to 60% by mass, more preferably 3 to 55% by mass, and further more preferably 5 to 50% by mass with respect to 100% by mass of the total of the aqueous medium and the mixed resin (C). Preferably, 5-45 mass% is especially preferable. When the addition amount is less than 1% by mass, the resin content of the resulting aqueous resin dispersion is too low to exhibit the performance of the coating film, and when it exceeds 60% by mass, aqueous dispersion tends to be difficult. is there.

  The container for aqueous dispersion is not particularly limited, and a known solid / liquid stirring device, emulsifier, autoclave, or the like can be used. It is preferable if pressurization of 0.1 MPa or more is possible. The stirring method and the rotational speed of stirring in the present invention are not particularly limited. Sufficient aqueous formation is achieved even with low-speed stirring that allows the resin to be in a floating state in an aqueous medium, and high-speed stirring (for example, 1000 rpm or more) is not essential, and an aqueous resin dispersion can be produced with a simple apparatus.

  The temperature when the aqueous dispersion of the mixed resin (C) is preferably 80 to 250 ° C. More preferably, it is 90-200 degreeC, More preferably, it is 100-190 degreeC. When the temperature in the tank is less than 80 ° C., aqueous dispersion of the polyolefin resin may be insufficient. When the temperature in a tank exceeds 250 degreeC, there exists a possibility that the molecular weight of polyolefin resin may fall.

  By using the method of the present invention, the mixed resin (C) can be finely and stably dispersed in an aqueous medium, and the number average particle diameter (hereinafter, mn) of the resin can be 3 μm or less. mn is preferably 1 μm or less, more preferably 0.5 μm or less, and still more preferably 0.3 μm or less from the viewpoint of storage stability and low-temperature film-forming properties. Further, the volume average particle diameter (hereinafter, mv) can be 3 μm or less, preferably 1 μm or less, and more preferably 0.5 μm or less.

  The aqueous resin dispersion thus obtained may be appropriately distilled off the aqueous medium or diluted with water and / or an organic solvent so as to obtain a desired viscosity and resin content. The resin content in the aqueous resin dispersion can be appropriately selected depending on the film forming conditions, the desired thickness and performance of the resin coating film, and is not particularly limited, but keeps the viscosity of the coating composition moderately, and 1-60 mass% is preferable with respect to 100 mass% of resin aqueous dispersion at the point which expresses favorable film formation ability, 3-55 mass% is more preferable, 5-50 mass% is further more preferable, 5-45 Mass% is particularly preferred.

  In the aqueous resin dispersion of the present invention, in order to further improve various coating film performances such as adhesion and solvent resistance, a total amount of the resins (A) and (B) in the aqueous resin dispersion is 100 masses. % To 0.01 to 50% by mass, preferably 0.1 to 40% by mass. As the crosslinking agent, a crosslinking agent having self-crosslinking property, a compound having a plurality of functional groups that react with a carboxyl group or a hydroxyl group in the molecule, a metal complex having a polyvalent coordination site, and the like can be used. Preferred are isocyanate compounds, melamine compounds, urea compounds, epoxy compounds, carbodiimide compounds, oxazoline group-containing compounds, zirconium salt compounds, phenol resins, silane coupling agents, and the like. Moreover, you may use combining these crosslinking agents.

  In the aqueous resin dispersion of the present invention, various agents such as leveling agents, antifoaming agents, anti-waxing agents, pigment dispersants, UV absorbers, pigments such as titanium oxide, zinc white, carbon black, etc. A dye may be added.

    The aqueous resin dispersion of the present invention is excellent in adhesiveness to various substrates such as a TPO substrate, a thermoplastic resin film substrate, a metal substrate, a glass substrate, paper, and synthetic paper.

  Examples of thermoplastic resin films include polyamide resins such as nylon 6, nylon 66, nylon 46, polyethylene terephthalate, polyethylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polybutylene terephthalate, polybutylene naphthalate, polylactic acid, etc. A film made of a polyester resin, a polyolefin resin such as polypropylene or polyethylene, a polyimide resin, a polyarylate resin, or a mixture thereof, or a laminate of these films. The thermoplastic resin film may be an unstretched film or a stretched film, and the production method is not limited. Although the thickness of a thermoplastic resin film is not specifically limited, Usually, what is necessary is just 1-500 micrometers. Especially, the resin aqueous dispersion of this invention is excellent in the adhesiveness to the thermoplastic resin film which consists of a polyester resin or polyolefin resin.

  The aqueous resin dispersion of the present invention can be applied by a known coating method. As a coating method, various substrate surfaces can be formed by known film forming methods such as gravure roll coating, reverse roll coating, wire bar coating, lip coating, air knife coating, curtain flow coating, spray coating, dip coating, brush coating, etc. It is possible to form a uniform resin coating in close contact with the surface of various substrates by coating it uniformly and setting it at around room temperature as necessary, followed by heat treatment for drying or drying and baking. it can. As a heating device at this time, a normal hot air circulation type oven, an infrared heater, or the like may be used.

  In addition, the thickness of the resin coating film formed using the aqueous resin dispersion of the present invention is appropriately selected depending on the application, but is preferably 0.01 to 30 μm, preferably 0.02 to 10 μm. More preferably, 0.03 to 9 μm is more preferable, and 0.05 to 8 μm is particularly preferable. When the thickness of the resin coating film is less than 0.01 μm, the heat sealability deteriorates. In addition, since the resin aqueous dispersion of this invention expresses various outstanding performances including heat-sealability at a thickness of several μm or less, there is no need to apply more than 10 μm unless there is a special reason. In order to adjust the thickness of the resin coating film, an apparatus used for coating and its use conditions are appropriately selected, or an aqueous resin dispersion having an appropriate concentration is used.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. Various characteristics were measured or evaluated by the following methods.

1. Resin characteristics (1) Resin composition
^It calculated | required from < ¹ > H-NMR analysis (The product made by Varian, 300MHz). The polyolefin resin was measured at 120 ° C. using orthodichlorobenzene (d ₄ ) as a solvent.
(2) Melt flow rate of polyolefin resin It measured by the method of JIS6730 description (190 degreeC, 2160g load).

2. Characteristics of Aqueous Resin Dispersion (1) Aqueous Dispersion Yield The aqueous resin dispersion after the aqueous dispersion was subjected to pressure filtration with a 600 mesh stainless steel filter (plain weave, wire diameter 35 μm, filtration area 133 cm ² ). After 2 MPa (G)), the resin remaining on the filter was dried by vacuum drying at 80 ° C. for 1 hour, the resin weight was measured, and the yield was calculated from the charged resin weight. When the entire amount could not be filtered at one time, the filter was replaced. In that case, the total residual resin amount was evaluated.
(2) Solid content concentration of aqueous resin dispersion A suitable amount of the aqueous resin dispersion after 600 mesh filtration was weighed and heated at 150 ° C. until the mass of the residue (solid content) reached a constant weight. Asked.
(3) Average particle diameter of resin aqueous dispersion Number average particle of resin aqueous dispersion after 600 mesh filtration using Nikkiso Co., Ltd., Microtrac particle size distribution analyzer UPA150 (MODEL No. 9340, dynamic light scattering method) The diameter and the weight average particle diameter were determined. Here, the refractive index of the resin used for calculating the particle diameter was set to 1.50.
(4) Storage Stability 30 g of the aqueous resin dispersion after 600 mesh filtration was placed in a transparent glass container (internal volume 50 ml) and allowed to stand at room temperature for 2 days, and visually evaluated for aggregates.
◯: No aggregation at all Δ: Fine aggregates are slightly confirmed, but no separation of solid and liquid is observed ×: Aggregation is confirmed and separation of solid and liquid is observed

3. Characteristics of Coating Film In the following evaluation, as a base material, a TPO (Mitsui Chemicals Co., Ltd .: Miralastomer 6030N) molded into a sheet shape (thickness 1 mm) with a T die (hereinafter referred to as a TPO sheet) was used. As the aqueous dispersion, one that was allowed to stand at room temperature for 2 days after filtration through 600 mesh was used.
(1) Wettability The aqueous resin dispersion was applied to a TPO sheet using a Meyer bar so that the film thickness after drying was 1 μm, and then dried at 90 ° C. for 2 minutes. The degree of wetting of the coating layer of the obtained laminated sheet was visually evaluated according to the following criteria.
○: No repelling ×: Repelling was confirmed (Repelling can be confirmed in about 5% or more of the coat area)
(2) Adhesion (tape peeling test)
The dried laminated sheet obtained above was allowed to stand at room temperature for 1 day and then evaluated. A cellophane tape (TF-12 manufactured by Nichiban Co., Ltd.) was attached to the adhesive surface, and the degree of peeling when the tape was peeled at once was visually evaluated according to the following criteria.
○: No peeling at all Δ: Partial peeling off ×: Most peeling off (3) TPO / TPO adhesiveness Using a Mayer bar so that the film thickness after drying the aqueous resin dispersion on the TPO sheet is 2 μm After coating, the laminate sheet was obtained by drying at 90 ° C. for 2 minutes. The coated surfaces of the obtained laminated sheets were bonded together and pressed at 100 ° C. with a heat press (sealing pressure 0.2 MPa / cm ² for 10 seconds). This sample was cut out at a width of 15 mm, and one day later, the peel strength of the film was measured at a tensile speed of 200 mm / min and a tensile angle of 90 degrees using a tensile tester (Intesco Precision Universal Material Tester Model 2020 manufactured by Intesco Corporation). The measurement was performed at n = 5, and the measured value was the average value.
(4) An aqueous resin dispersion was coated with a Meyer bar on a TPO / stainless steel (hereinafter referred to as SUS) adhesive SUS plate (thickness 1.5 mm) so that the thickness of the coating layer after drying would be 10 μm, and 90 ° C. For 5 minutes. The SUS plate was heated at 200 ° C. for 3 minutes, and a TPO sheet softened at 160 ° C. for 1.5 minutes on the coating surface was laminated through the coating film, Pressed under conditions. After leaving at room temperature for 1 day, the TPO sheet was cut out to a width of 5 mm, and using a tensile tester (precision universal material testing machine 2020 manufactured by Intesco) at 25 ° C., a pulling speed of 50 mm / min, and a pulling angle of 180 degrees. The peel strength of the coating film was measured. The measurement was performed at n = 5, and the measured value was the average value.

  As the polyolefin resin (A), Bondine HX8290 (manufactured by Arkema Inc., hereinafter referred to as HX8290), which is a commercially available product, was used. The properties of the polyolefin resin (A) are summarized in Table 1.

As the thermoplastic elastomer (B), the following commercially available products were used.
SEBS (styrene-ethylene / butylene-styrene block copolymer: Dynalon 8600P manufactured by JSR, styrene content 15% by mass), SBS (styrene-butadiene-styrene block copolymer: Clayton DKX415 manufactured by Kraton Polymer Japan Co., Ltd., containing styrene 35% by mass), SIS (styrene-isoprene-styrene block copolymer: Kraton D1124 manufactured by Kraton Polymer Japan, styrene content 30% by mass), SEBC (styrene-ethylene / butylene-ethylene crystal block copolymer: JSR) Dynalon 4600P, styrene content 20% by mass), HSBR (hydrogenated styrene-butadiene random copolymer: Dynalon 1320P, styrene content 10% by mass), f-SEBC ( Functional group imparting type of tylene-ethylene / butylene-ethylene crystal block copolymer: Dynalon 4630P manufactured by JSR, styrene content 5% by mass, M-SEBS1 (maleic acid of styrene-ethylene / butylene-styrene block copolymer) Grant type: Clayton FG1924X manufactured by Kraton Polymer Japan, styrene content 13% by mass, maleic acid content 1.0% by mass), CEBC (ethylene crystal-ethylene / butylene-ethylene crystal copolymer: Dynalon 6100P manufactured by JSR) , TPO (Milastomer 6030N, manufactured by Mitsui Chemicals), M-SEBS2 (maleic acid imparting type of styrene-ethylene / butylene-styrene block copolymer: Kraton FG1901X manufactured by Kraton Polymer Japan, styrene content 30% by mass, Maleic acid content of 1.9 wt%)

[Example 1]
A polyolefin resin “HX8290” and a thermoplastic elastomer “SEBS” are dry blended at a mass ratio of “HX8290” / “SEBS” = 99/1, and this is mixed with a twin-screw kneader (Ikegai PCM-30 The mixture was melt kneaded with a screw rotation of 180 rpm and a discharge rate of 100 g / min, and pelletized with a cutter to obtain a mixed resin.

  Then, using a stirrer equipped with a 1 L glass container that can be sealed with a heater, 125.0 g of melt-kneaded mixed resin, 100.0 g of 2-propanol, 4.6 g of triethylamine and 270.4 g of distillation When water was charged into a glass container and stirred at a rotation speed of 400 rpm, no resin granular precipitates were observed at the bottom of the container, confirming that it was in a floating state. Therefore, while maintaining this state, the heater was turned on, the system temperature was set to 120 ° C., and the mixture was further stirred for 60 minutes. Thereafter, the mixture was cooled to about 40 ° C. while stirring at an air cooling speed of 400 rpm, and then filtered through a 600 mesh stainless steel filter to obtain an aqueous resin dispersion. Various properties of the aqueous resin dispersion are shown in Table 2.

[Examples 2 to 14]
As shown in Table 2, a resin aqueous dispersion was obtained by performing the same operation as in Example 1 except that the type and mixing ratio of the thermoplastic elastomer were changed. Various properties of the aqueous resin dispersion are shown in Table 2.

[Comparative Example 1]
Using the polyolefin resin “HX8290” alone, the same aqueous dispersion operation as in Example 1 was performed to obtain an aqueous resin dispersion. Various characteristics of the aqueous resin dispersion are shown in Table 3.

[Comparative Examples 2 to 10]
The thermoplastic elastomer not melt kneaded shown in Table 3 was subjected to the same aqueous dispersion operation as in Example 1. However, almost no aqueous resin dispersion was obtained, and all the resin remained on the filter.

[Comparative Example 11]
30 g of thermoplastic elastomer “SBS” and 170 g of toluene were charged into a separable flask having an internal volume of 500 ml and dissolved at room temperature with stirring. A solution obtained by dissolving 2.0 g of quaternary dodecylethyldimethylammonium sulfate ethyl ester in 100 g of water was added to the obtained toluene solution, and this was added to a homomixer (“TK Homomixer M type” manufactured by Tokushu Kika Kogyo Co., Ltd.). )) For 3 minutes with stirring to obtain an emulsion. The rotation speed and temperature during stirring and mixing were set to 12,000 rpm and 30 ° C., respectively. The obtained emulsion was heated to 40 to 70 ° C. under reduced pressure of 50 to 500 torr to distill off toluene. Distillation was further advanced, and the pressure was released when the total amount of distillate reached about 190 g, and water was added to adjust the solid content concentration of the aqueous resin dispersion to 25%. Then, it filtered with the 600 mesh stainless steel filter, and obtained resin aqueous dispersion. Various characteristics of the aqueous resin dispersion are shown in Table 3.

[Comparative Example 12]
The aqueous resin dispersion of “HX8290” obtained in Comparative Example 1 and the aqueous resin dispersion of “SBS” obtained in Comparative Example 11 were such that “HX8290” / “SBS” = 70/30 in the resin component. Were mixed and stirred to obtain an aqueous resin dispersion. Various characteristics of the aqueous resin dispersion are shown in Table 3.

[Comparative Example 13]
As shown in Table 3, a resin aqueous dispersion was obtained by performing the same operation as in Example 3 except that “M-SEBS2” having a maleic acid content of 1.9% by mass was used as the thermoplastic elastomer. . Various characteristics of the aqueous resin dispersion are shown in Table 3.

  From the results of Examples 1 to 6, even a thermoplastic elastomer (Comparative Example 2) that could not be dispersed in water without a non-volatile aqueous dispersion aid conventionally is mixed with a polyolefin resin to be aqueous. Dispersion was possible. In particular, when the mixing ratio in the resin was 30% by mass or less, the aqueous dispersion yield was 100%. Moreover, even if the kind of thermoplastic elastomer changed from the result of Examples 7-14, aqueous dispersion was possible similarly.

  From the comparison between Comparative Example 1 and Examples 1 to 14, the aqueous dispersion obtained in Examples was better than the aqueous resin dispersion obtained in Comparative Example 1 in terms of wettability, adhesion and adhesion to the TPO sheet. The performance was excellent. This is considered that the performance was improved by containing a thermoplastic elastomer having a high affinity for the TPO base material in the aqueous resin dispersion.

  From the result of the comparative example 11, even if it was the aqueous dispersion of the thermoplastic elastomer single-piece | unit, performances, such as adhesiveness with respect to a TPO sheet, adhesiveness, were inferior by the influence containing the non-volatile aqueous | water-based auxiliary agent.

  Comparative Example 12 was an aqueous resin dispersion having the same type and mixing ratio of polyolefin and thermoplastic elastomer as Example 7, but the effect of Comparative Example 11 used for preparation containing a non-volatile aqueous additive. Therefore, the performance such as adhesion and adhesion to the TPO sheet was inferior.

From the result of Comparative Example 13, when a thermoplastic elastomer having a high content of unsaturated carboxylic acid component was used, the resulting aqueous resin dispersion was agglomerated and the storage stability was poor. In Example 12, although some agglomerates were observed in the storage stability test, it was not a problem at all in use.

Claims (5)

Aqueous resin dispersion containing a polyolefin resin (A) containing 1.5 to 10% by mass of an unsaturated carboxylic acid component and a thermoplastic elastomer (B) having an unsaturated carboxylic acid component content of less than 1.5% by mass An aqueous resin dispersion, wherein the content of the non-volatile aqueous additive is 0.1 parts by mass or less with respect to 100 parts by mass of the total amount of (A) and (B). The aqueous resin dispersion according to claim 1, wherein the mass ratio (A) / (B) of the polyolefin resin (A) to the thermoplastic elastomer (B) is 99.5 / 0.5 to 50/50. body. The aqueous resin dispersion according to claim 1 or 2, wherein the thermoplastic elastomer (B) is a styrene-based thermoplastic elastomer or an olefin-based thermoplastic elastomer. A mixed resin obtained by kneading a polyolefin resin (A) containing 1.5 to 10% by mass of an unsaturated carboxylic acid component and a thermoplastic elastomer (B) having an unsaturated carboxylic acid component content of less than 1.5% by mass. The resin aqueous solution according to any one of claims 1 to 3, comprising a step (I) for obtaining (C) and an aqueous dispersion step (II) for dispersing the mixed resin (C) in an aqueous medium. A method for producing a dispersion. The method for producing an aqueous resin dispersion according to claim 4, wherein the kneading method in the step (I) is melt kneading.