JP2021147553A - Copolymer latex, aqueous adhesive composition, and laminate - Google Patents

Abstract

To provide a copolymer latex which has little variation in the amount of application, has excellent adhesive strength at the initial stage of lamination and after curing and is excellent in preventing slippage immediately after lamination to a base material while having storage stability when used for an aqueous adhesive.SOLUTION: There is provided a copolymer latex containing a copolymer containing (a) 10.0 mass% or more and 60.0 mass% or less of a conjugated diene monomer unit, (b) 0.5 mass% or more and 15.0 mass% or less of an ethylenically unsaturated carboxylic acid monomer unit and (c) 25.0 mass% or more and 89.5 mass% or less of other monomer units copolymerizable with the conjugated diene monomer unit and/or the ethylenically unsaturated carboxylic acid monomer unit (provided that the total of (a), (b) and (c) is 100 mass%), wherein the copolymer latex has a solid content of 53.0 mass% or more and 60.0 mass% or less and the copolymer latex has a viscosity of 300 mPa s or more and 10000 mPa s or less.SELECTED DRAWING: None

Description

The present invention relates to copolymer latex, aqueous adhesive compositions, and laminates.

Solvent-type adhesives containing a large amount of solvent are used in a wide range of fields because of their good adhesiveness, high drying speed, ease of work, and the like. However, many of the solvents contained in these adhesives are toxic and have a risk of polluting the environment. Therefore, the development of solvent-free water-based adhesives is underway.

Among them, adhesives that replace solvent-based chloroprene adhesives are being actively studied. The solvent-based chloroprene adhesive has features such as good initial adhesiveness after drying and laminating, strong adhesive strength after curing, and good heat-resistant creep property. As an aqueous system of the solvent-based chloroprene adhesive, for example, emulsification of chloroprene rubber is being studied.
For example, Patent Document 1 proposes to obtain an emulsion by a method of emulsion polymerization of chloroprene and an ethylenically unsaturated carboxylic acid using a vinyl alcohol-based copolymer as a dispersant. Patent Document 2 proposes an adhesive composition using a synthetic rubber-based latex having a pressure-sensitive gelling property. Patent Document 3 proposes an adhesive composition using a styrene-butadiene latex having an acrylic component. Patent Document 4 proposes a copolymer latex having excellent initial adhesive strength and an adhesive composition thereof.

Japanese Unexamined Patent Publication No. 2004-346183 JP-A-2009-235234 Japanese Unexamined Patent Publication No. 2010-185033 JP-A-2018-28048

The adhesive compositions of Patent Documents 1 to 4 contain a predetermined copolymer latex, but from the viewpoint of realizing an aqueous adhesive that achieves both initial and post-curing adhesive strength and prevention of displacement immediately after bonding. , I'm still not fully satisfied.

In addition, the water-based adhesive is also required to have functionality such as storage stability and suppression of variation in the coating amount.

INDUSTRIAL APPLICABILITY When used as an aqueous adhesive, the present invention has little variation in the coating amount while having storage stability, is excellent in adhesive strength at the initial stage of bonding and after curing, and prevents displacement immediately after bonding to a substrate. An object of the present invention is to provide an excellent copolymer latex.

As a result of diligent research to solve the above problems, the present inventors have contained a copolymer containing a conjugated diene-based monomer and an ethylenically unsaturated carboxylic acid monomer in a predetermined ratio, and have a predetermined solid content. When used in an aqueous adhesive containing the copolymer latex, the copolymer latex having a viscosity and a viscosity has storage stability, but there is little variation in the coating amount, and the adhesive strength at the initial stage of bonding and after curing is improved. We have found that it is excellent and is excellent in preventing displacement immediately after bonding to a base material, and has completed the present invention.
That is, the present invention is as follows.

[1]
(A) Conjugated diene monomer unit 10.0% by mass or more and 60.0% by mass or less,
(B) Ethylene unsaturated carboxylic acid monomer unit 0.5% by mass or more and 15.0% by mass or less, and
(C) 25.0% by mass or more and 89.5% by mass or less of other monomer units copolymerizable with the conjugated diene-based monomer and / or the ethylene-based carboxylic acid monomer (however, (a)). , (B), and (c) are 100% by mass), which is a copolymer latex containing a copolymer.
The solid content of the copolymer latex is 53.0% by mass or more and 60.0% by mass or less.
The viscosity of the copolymer latex is 300 mPa · s or more and 10000 mPa · s or less.
Copolymer latex.
[2]
The pH of the copolymer latex is 5.0 or more and 9.0 or less.
The copolymer latex according to [1] [3]
The time required for the adhesive strength of 0.06 N / mm ² to appear at room temperature is 10 seconds or more and 60 seconds or less.
The copolymer latex according to [1] or [2].
[4]
The gel fraction is 40% by mass or more and 95% by mass or less.
The copolymer latex according to any one of [1] to [3].
[5]
An aqueous adhesive composition containing the copolymer latex according to any one of [1] to [4].
[6]
A laminate produced by using the aqueous adhesive composition according to [5].

According to the present invention, when used as an aqueous adhesive, it has storage stability, little variation in the coating amount, excellent adhesive strength at the initial stage of bonding and after curing, and deviation immediately after bonding to a substrate. It is possible to provide a copolymer latex having excellent prevention.

Hereinafter, embodiments for carrying out the present invention (hereinafter, referred to as “the present embodiment”) will be described in detail. The present invention is not limited to the following embodiments, and can be variously modified and implemented within the scope of the gist thereof.

Hereinafter, in the present specification, the content of the monomer unit constituting the copolymer latex of the present embodiment and the amount of the raw material (monomer) charged as the polymerization component of the copolymer latex of the present embodiment. Alternatively, unless otherwise specified, the addition amount is expressed in parts by mass with respect to the total amount of the monomer units (100 parts by mass) and the total amount of the monomers (100 parts by mass), respectively.
Further, in the present specification, the term "monomer" is used in the sense of including all of the monomers constituting the copolymer latex of the present embodiment.
Further, in the present specification, the notation "(meth) acrylate" is used in the sense of including both methacrylate and acrylate.

[Copolymer latex]
The copolymer latex of the present embodiment has (a) a conjugated diene-based monomer unit of 10.0% by mass or more and 60.0% by mass or less, and (b) an ethylene-based unsaturated carboxylic acid monomer unit of 0.5% by mass. % Or more and 15.0% by mass or less, and (c) 25.0% by mass or more and 89.5% by mass of other monomer units copolymerizable with the conjugated diene-based monomer and / or the ethylene-based carboxylic acid monomer. Contains a copolymer containing less than or equal to%. The copolymer in the present embodiment includes (a) conjugated diene-based monomer unit, (b) ethylene-based unsaturated carboxylic acid monomer unit, (c) conjugated diene-based monomer and / or ethylene-based. It can also be said that it is composed of other monomer units copolymerizable with the carboxylic acid monomer. Further, the copolymer in the present embodiment is (a) a conjugated diene-based monomer unit, (b) an ethylene-based unsaturated carboxylic acid monomer unit, (c) a conjugated diene-based monomer and / or an ethylene-based unit. It preferably consists of other monomeric units copolymerizable with the carboxylic acid monomer.
Here, it is copolymerized with (a) a conjugated diene-based monomer unit, (b) an ethylene-based unsaturated carboxylic acid monomer unit, (c) a conjugated diene-based monomer and / or an ethylene-based carboxylic acid monomer. The total of other possible monomeric units is 100% by weight.
The solid content of the polymer latex of the present embodiment is 53.0% by mass or more and 60.0% by mass or less.
The viscosity of the polymer latex of the present embodiment is 300 mPa · s or more and 10,000 mPa · s or less.

The copolymer latex of the present embodiment has storage stability, little variation in the coating amount, excellent adhesive strength at the initial stage of bonding and after curing, and excellent prevention of displacement immediately after bonding to a substrate.

<(A) Conjugated diene monomer unit>
By containing (a) a conjugated diene-based monomer unit (hereinafter, also referred to as a component (a)), the copolymer in the present embodiment can impart adhesiveness to the copolymer latex.

Examples of the conjugated diene-based monomer include 1,3-butadiene, isoprene, 2-chloro-1,3-butadiene and the like. These can be used alone or in combination of two or more.

In the present embodiment, the proportion of the (a) conjugated diene-based monomer unit in the copolymer is 10.0% by mass or more and 60.0% by mass or less. (A) The lower limit of the proportion of the conjugated diene-based monomer unit in the copolymer is preferably 13.0% by mass or more, more preferably 15.0% by mass or more. (A) The upper limit of the proportion of the conjugated diene-based monomer unit in the copolymer is preferably 57.0% by mass or less, more preferably 55.0% by mass or less.

(A) By setting the content of the conjugated diene-based monomer unit in the range of 10.0% by mass or more and 60.0% by mass or less, appropriate flexibility is imparted to the copolymer latex, and after curing. Adhesive strength can be improved.

<(B) Ethylene unsaturated carboxylic acid monomer unit>
The copolymer in the present embodiment can impart aqueous dispersion stability to the copolymer latex by containing (b) an ethylene-based unsaturated carboxylic acid monomer unit.

Examples of the ethylene-based unsaturated carboxylic acid monomer include monobasic ethylene-based unsaturated carboxylic acid monomers such as acrylic acid, methacrylic acid, and octenoic acid; and dibasic such as itaconic acid, maleic acid, and fumaric acid. Ethylene-based unsaturated carboxylic acid monomer; and the like. These can be used alone or in combination of two or more.

Here, monobasic is an acid having a structure capable of releasing one proton in water. Dibasic is an acid having a structure capable of releasing two protons in water. That is, the monobasic ethylene-based unsaturated carboxylic acid monomer has one carboxyl group, and the dibasic ethylene-based unsaturated carboxylic acid monomer has two carboxyl groups. It is an ethylene-based unsaturated carboxylic acid monomer having one.

In the present embodiment, the proportion of the ethylene-based unsaturated carboxylic acid monomer unit in the copolymer is 0.5% by mass or more and 15.0% by mass or less. (B) The lower limit of the proportion of the ethylene-based unsaturated carboxylic acid monomer unit in the copolymer is preferably 1.0% by mass or more, more preferably 1.5% by mass or more. (B) The upper limit of the proportion of the ethylene-based unsaturated carboxylic acid monomer unit in the copolymer is preferably 13.0% by mass or less, and more preferably 10.0% by mass.

(B) Dispersion stability (storage stability) of the copolymer latex by setting the content of the ethylene-based unsaturated carboxylic acid monomer unit in the range of 0.5% by mass or more and 15.0% by mass or less. It is possible to maintain good mechanical stability and initial adhesive strength of the aqueous adhesive composition using the copolymer latex. For example, (b) when the content of the ethylene-based unsaturated carboxylic acid monomer unit is less than 0.5% by mass, the storage stability is lowered and precipitation or aggregation occurs.

Further, in the present embodiment, from the viewpoint of improving the balance between storage stability, mechanical stability and initial adhesive strength, (b) the ethylene-based unsaturated carboxylic acid monomer unit is dibasic. It is preferable to contain more monobasic substances.
Specifically, (b) the monobasic ethylene-based unsaturated carboxylic acid monomer unit as the ethylene-based unsaturated carboxylic acid monomer unit is preferably 0.5% by mass or more and 15% by mass or less. It is more preferably 1.0% by mass or more and 13.0% by mass or less, and further preferably 1.5% by mass or more and 10.0% by mass or less.
(B) As the ethylene-based unsaturated carboxylic acid monomer unit, the dibasic ethylene-based unsaturated carboxylic acid monomer unit is preferably 0% by mass or more and 1.0% by mass or less, preferably 0.03% by mass. It is more preferably 0.8% by mass or less, and more preferably 0.05% by mass or more and 0.7% by mass or less.
Here, the total of the monobasic ethylene-based unsaturated carboxylic acid monomer unit and the dibasic ethylene-based unsaturated carboxylic acid monomer unit is 100 in total of (a), (b), and (c). It is 0.5% by mass or more and 15% by mass or less with respect to mass%.
Since the numerical ranges of the monobasic ethylene-based unsaturated carboxylic acid monomer unit and the dibasic ethylene-based unsaturated carboxylic acid monomer unit are as described above, the storage stability tends to be excellent.

<(C) A conjugated diene-based monomer and / or another monomer unit copolymerizable with an ethylene-based carboxylic acid monomer>
In the present embodiment, (c) the conjugated diene-based monomer and / or the other monomer copolymerizable with the ethylene-based carboxylic acid monomer is the conjugated diene-based monomer and / or the ethylene-based carboxylic acid monomer. There is no limitation as long as it can be copolymerized with the monomer. By appropriately selecting the types of the other monomers, various properties can be imparted to the copolymer latex.

(C) Other monomers include, for example, a monomer having a hydroxyalkyl group, a vinyl cyanide-based monomer, an aromatic vinyl-based monomer, a (meth) acrylic acid alkyl ester-based monomer, and the like. Can be mentioned. One of these can be used alone, and two or more of them can be used in combination.

In the present embodiment, the proportion of (c) other monomer units in the copolymer is 25.0% by mass or more and 89.5% by mass or less.

Examples of the monomer having a hydroxyalkyl group include ethylenically unsaturated carboxylic acid hydroxyalkyl ester-based monomers, allyl alcohol, and N-methylolacrylamide. These may be used individually by 1 type, and may be used in combination of 2 or more type.

Specific examples of the ethylenically unsaturated carboxylic acid hydroxyalkyl ester-based monomer include 2-hydroxyethyl (meth) acrylate and 2-hydroxybutyl (meth) acrylate.

Examples of the vinyl cyanide-based monomer include acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, and the like. These may be used individually by 1 type, and may be used in combination of 2 or more type.

Examples of the aromatic vinyl-based monomer include styrene, α-methylstyrene, vinyltoluene, p-methylstyrene and the like. These may be used individually by 1 type, and may be used in combination of 2 or more type.

Examples of the (meth) acrylic acid alkyl ester-based monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and (meth) acrylic acid. Examples thereof include 2-ethylhexyl, cyclohexyl (meth) acrylate, and dodecyl (meth) acrylate. These may be used individually by 1 type, and may be used in combination of 2 or more type.

Further, as the other monomer (c), various ones other than those described above can be used. Examples of such monomers include aminoalkyl esters such as aminoethyl acrylate, dimethylaminoethyl acrylate, and diethylaminoethyl acrylate; pyridines such as 2-vinylpyridine and 4-vinylpyridine; and glycidyl acrylate. , Glycidyl esters such as glycidyl methacrylate; amides such as acrylamide, methacrylic amide, N-methylol acrylamide, N-methyl acrylamide, N-methyl methacrylic amide, glycidyl methacrylic amide, N, N-butoxymethyl acrylamide; vinyl acetate and the like. Carboxylic acid vinyl esters; vinyl halides such as vinyl chloride; divinylbenzene, (poly) ethylene glycol di (meth) acrylate, hexanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, Polyfunctional vinyl-based monomers such as allyl (meth) acrylate; and the like. These may be used individually by 1 type, and may be used in combination of 2 or more type.

The (c) other monomer in the copolymer latex of the present embodiment preferably contains an aromatic vinyl-based monomer. The aromatic vinyl-based monomer is preferably contained in the largest amount among the other monomers, and is preferably contained in a total of 100% by mass of the component (a), the component (b), and the component (c). It is 26% by mass or more and 89% by mass or less, and more preferably 28% by mass or more and 80% by mass or less. When the amount of the aromatic vinyl-based monomer is in the above range, the adhesive strength after curing tends to be excellent.

In the copolymer latex of the present embodiment, the copolymer containing the component (a), the component (b), and the component (c) is dispersed in an aqueous solvent. The solid content of the copolymer latex of the present embodiment is 53.0% by mass or more and 60.0% by mass or less. By setting the upper limit of the solid content concentration of the copolymer latex to 60.0% by mass, the initial adhesive strength can be increased. By setting the lower limit of the solid content concentration of the copolymer latex to 53.0% by mass, the variation in the coating amount can be suppressed.
From the viewpoint of further increasing the initial adhesive strength and further suppressing the variation in the coating amount, the solid content of the copolymer latex is preferably 53.5% by mass or more and 59.5% by mass or less, more preferably 54.0% by mass. % Or more and 59.0% by mass or less.
For the solid content of the copolymer latex, for example, the water content can be adjusted in the polymerization reaction during the production of the copolymer latex, the water content can be added to the copolymer latex after the polymerization reaction, or the water content can be reduced by an evaporator or the like. It can be controlled by such as.
The solid content of the copolymer latex can be measured by the method described in Examples.

The viscosity of the copolymer latex of the present embodiment is 300 mPa · s or more and 10,000 mPa · s or less. By setting the lower limit of the viscosity of the copolymer latex to 300 mPa · s, it is possible to suppress the deviation immediately after bonding. By setting the upper limit of the viscosity of the copolymer latex to 10000 mPa · s, it is possible to suppress the variation in the coating amount.
From the viewpoint of further suppressing the deviation immediately after bonding and the variation in the coating amount, the viscosity of the copolymer latex is preferably 350 mPa · s or more and 9000 mPa · s or less, and more preferably 400 mPa · s or more and 8000 mPa · s or less.
The viscosity of the copolymer latex can be controlled, for example, by the blending amount and type of the component (c) constituting the copolymer, the pH and solid content of the copolymer latex, the particle size of the copolymer, and the like. .. Among these, the viscosity can be easily adjusted by controlling the particle size of the polymer, and the viscosity can be controlled to increase as the particle size decreases.
The solid content of the copolymer latex can be measured by the method described in Examples.

The pH of the copolymer latex of the present embodiment is preferably 5.0 or more and 9.0 or less, more preferably 5.5 or more and 8.8 or less, and further preferably 6.0 or more and 8.5 or less. Is. By setting the lower limit of pH to 5.5 or more, the storage stability and mechanical stability of the copolymer latex tend to be further improved. By setting the lower limit of pH to 8.8 or less, the initial adhesive strength tends to be increased.
The pH of the copolymer latex of the present embodiment can be controlled by adding a pH adjuster into the system during and / or after the polymerization reaction in the production of the copolymer latex.
The pH of the copolymer latex can be measured by the method described in Examples.

The time required for the copolymer latex in the present embodiment ^{to develop an adhesive strength of 0.6 N / mm 2 at} room temperature is preferably 10 seconds or more and 60 seconds or less, preferably 10 seconds or more and 55 seconds or less. More preferably, it is more preferably 10 seconds or more and 50 seconds or less. When the above time is 10 seconds or more, the workability of re-tensioning after laminating the base materials tends to be excellent. When the above time is 60 seconds or less, it is possible to suppress the work time for preventing the base materials from peeling off after the base materials are bonded, and there is a tendency that the work efficiency at the time of on-site work can be improved.
The time required for the adhesive strength of 0.6 N / mm ² to appear at room temperature is controlled, for example, by the amount and type of the component (c) constituting the copolymer, the pH and solid content of the copolymer latex, and the like. be able to.
The time required for the adhesive strength of 0.6 N / mm ² to develop at room temperature can be measured by the method described in Examples.

In the present embodiment, the gel fraction (ratio of toluene insoluble matter in the dried product obtained by drying the copolymer latex) is preferably 40% by mass or more and 95% by mass or less, and more preferably 45% by mass or more and 93% by mass. Hereinafter, it is more preferably 50% by mass or more and 90% by mass or less. By setting the gel fraction to 40% by mass or more, the cohesive force of the polymer tends to be improved and the adhesive strength after curing tends to be improved. By setting the gel fraction to 95% by mass or less, the initial adhesive strength tends to be improved.
The gel fraction can be controlled by a known method, but can be adjusted, for example, by the amount of the chain transfer agent used when synthesizing the copolymer.
The gel fraction can be measured by the method described in Examples.

In the present embodiment, the number average particle size of the copolymer particles contained in the copolymer latex is not particularly limited, but is preferably 50 nm or more and 500 nm or less, more preferably 80 nm or more and 450 nm or less, and further preferably. It is 100 nm or more and 400 nm or less.
The number average particle size can be adjusted, for example, by adjusting the amount of the emulsifier used in the production by emulsion polymerization or by using a known seed polymerization method.
The number average particle size can be measured by the method described in Examples.

[Manufacturing method of copolymer latex]
The copolymer latex of the present embodiment is obtained by a known emulsion polymerization method.

The method of emulsion polymerization is not particularly limited, and is basically a conventionally known method, based on a chain transfer agent, a surfactant, a radical polymerization initiator, and other additive components used as necessary in an aqueous medium. In the dispersion system as a constituent component, the monomer may be polymerized to synthesize copolymer particles, and an aqueous dispersion thereof, that is, latex may be produced.

At the time of polymerization, a method of making the monomer composition uniform in the entire polymerization process, a method of giving a morphological change in the morphological composition of the latex particles produced by changing the monomer composition sequentially or continuously in the polymerization process, etc., as desired. Various methods are available.

As the seed polymerization method, a method such as an internal seed method in which the copolymer latex is polymerized in the same reaction system after the seed is prepared, an external seed method using a separately prepared seed, or the like can be appropriately selected and used.

The method for producing the copolymer latex of the present embodiment is not particularly limited, and for example, a method of polymerizing with a radical initiator in the presence of an emulsifier in an aqueous medium can be adopted.

Here, examples of the emulsifier used include non-reactive emulsifiers such as conventionally known anionic emulsifiers, cationic emulsifiers, amphoteric emulsifiers, and nonionic emulsifiers; A so-called reactive emulsifier in which an ethylenic double bond is introduced into the product can be used.

Examples of the non-reactive anionic emulsifier include non-reactive alkyl sulfate ester, polyoxyethylene alkyl ether sulfate ester salt, alkylbenzene sulfonate, alkylnaphthalene sulfonate, alkylsulfosuccinate, and alkyldiphenyl ether disulfonate. , Naphthalene sulfonate formalin condensate, polyoxyethylene polycyclic phenyl ether sulfate ester salt, polyoxyethylene distyrene phenyl ether sulfate ester salt, fatty acid salt, alkyl phosphate, polyoxyethylene alkyl phenyl ether sulfate ester salt, etc. Can be mentioned.

Examples of the non-reactive cationic emulsifier include alkylammonium salts such as dodecylammonium chloride and quaternary ammonium salts.

Examples of the non-reactive amphoteric emulsifier include betaines such as lauryl betaine and stearyl betaine, and amino acid types such as lauryl-β-alanine, stearyl-β-alanine and lauryl di (aminoethyl) glycine.

Examples of the non-reactive nonionic emulsifier include non-reactive polyoxyethylene alkyl ether, polyoxyalkylene alkyl ether, polyoxyethylene polycyclic phenyl ether, polyoxyethylene distyrene phenyl ether, sorbitan fatty acid ester, and poly. Examples thereof include oxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, glycerin fatty acid ester, polyoxyethylene fatty acid ester, polyoxyethylene alkylamine, alkyl alkanolamide, and polyoxyethylene alkyl phenyl ether.

Examples of the reactive emulsifier include an anionic reactive emulsifier.
The anionic reactive emulsifier is, for example, an ethylenically unsaturated monomer having a sulfonic acid group, a sulfonate group or a sulfate ester group and a salt thereof, and is a sulfonic acid group or an ammonium salt or an alkali metal salt thereof. A compound having a group (ammonium sulfonate group or alkali metal sulfonate group) is preferable.
Specific examples of the anionic reactive emulsifier include alkylallyl sulfosuccinates (for example, Sanyo Kasei Co., Ltd. Eleminor ™ JS-2, JS-5; Kao Co., Ltd. Latemul ™ S-120. , S-180A, S-180; etc.), Polyoxyethylene alkylpropenylphenyl ether sulfate ester salt (for example, Aqualon ™ HS-10, HS-1025 manufactured by Daiichi Kogyo Seiyaku Co., Ltd., etc.) ), Α- [1-[(allyloxy) methyl] -2- (nonylphenoxy) ethyl] -ω-polyoxyethylene sulfate ester salt (for example, Adecaria Soap ™ SE-1025N manufactured by Asahi Denka Kogyo Co., Ltd.) Etc.), ammonium = α-sulfonato-ω-1- (allyloxymethyl) alkyloxypolyoxyethylene (for example, Aqualon KH-10 manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), etc., styrene sulfonic acid Examples include salt.

Examples of the reactive emulsifier include nonionic reactive emulsifiers.
Examples of the nonionic reactive emulsifier include α- [1-[(allyloxy) methyl] -2- (nonylphenoxy) ethyl] -ω-hydroxypolyoxyethylene (for example, Adecaria Soap NE manufactured by Asahi Denka Kogyo Co., Ltd.). -20, NE-30, NE-40, etc.), Polyoxyethylene alkyl propenylphenyl ether (for example, Aqualon RN-10, RN-20, RN-30, RN-50, etc. manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) ) Etc. can be mentioned.

The amount of the emulsifier used is preferably 0.1 parts by mass or more and 5.0 parts by mass or less, and more preferably 0.1 parts by mass or more and 4.5 parts by mass with respect to 100 parts by mass of the total monomer mixture. Hereinafter, it is more preferably 0.1 parts by mass or more and 4.0 parts by mass or less. As the emulsifier, one selected from the non-reactive emulsifier and the reactive emulsifier can be used alone or in combination of two or more.

The radical initiator is one that radically decomposes in the presence of heat or a reducing agent to initiate addition polymerization of the monomer, and either an inorganic initiator or an organic initiator can be used. .. Examples of preferred initiators include, for example, peroxodisulfuric acid salts, peroxides, azobis compounds and the like.

Specific examples of the initiator include potassium peroxodisulfate, sodium peroxodisulfate, ammonium peroxodisulfate, hydrogen peroxide, t-butylhydroperoxide, benzoyl peroxide, 2,2-azobisbutyronitrile, and cumenehydro. Peroxide and the like can be mentioned. These can be used alone or in combination of two or more.

Further, a so-called redox polymerization method in which a reducing agent such as acidic sodium bisulfite, ascorbic acid or a salt thereof, erythorbic acid or a salt thereof, or longalit is used in combination with the above-mentioned polymerization initiator can also be used.

Examples of the chain transfer agent used in the production of the copolymer latex of the present embodiment include α-methylstyrene dimer, which is one of the disulfides of nuclear-substituted α-methylstyrene; n-butyl mercaptan, t-butyl mercaptan, and the like. Mercaptans such as t-dodecyl mercaptan, n-octyl mercaptan, n-lauryl mercaptan; disulfides such as tetramethylthiuradium disulfide and tetraethylthiuradium disulfide; 2-ethylhexylthioglycolate; and the like. These can be used alone or in combination of two or more. Among these, mercaptans can be preferably used.

The polymerization temperature in the production of the copolymer latex of the present embodiment is, for example, 40 ° C. or higher and 100 ° C. or lower. Here, from the viewpoint of production efficiency and quality such as shock absorption of the obtained copolymer latex, the polymerization temperature in the period from the start of polymerization to the end of addition of the monomer mixture is preferably 45 ° C. or higher and 95 ° C. or higher. ° C or lower, more preferably 55 ° C or higher and 90 ° C or lower.

It is also possible to adopt a method of raising the polymerization temperature (so-called cooking step) in order to raise the polymerization conversion of each monomer after the addition of the whole monomer mixture to the polymerization system is completed. The polymerization temperature in such a step is usually 80 ° C. or higher and 100 ° C. or lower.

The polymerization solid content concentration in the production of the copolymer latex of the present embodiment is usually 30.0% by mass or more and 60.0% by mass or less, preferably 40, from the viewpoint of production efficiency and particle size control during emulsion polymerization. It is 0.0% by mass or more and 60.0% by mass or less. Here, the polymerized solid content concentration is the solid content concentration when the polymerization is completed, and refers to the ratio of the solid content mass obtained by drying to the original copolymer latex (including water) mass. When the polymerized solid content concentration is low, the solid content concentration of the copolymer latex may be increased through a concentration step in the production of the copolymerized latex.

In the production of the copolymer latex of the present embodiment, the pH may be adjusted after the polymerization reaction. In the present embodiment, a known pH adjuster can be used to adjust the pH of the copolymer latex. Preferred examples of the pH adjuster include amines such as sodium hydroxide, potassium hydroxide, ammonium hydroxide, sodium hydrogen carbonate, disodium hydrogen phosphate, monoethanolamine and triethanolamine.

In the present embodiment, the type of the aqueous solvent of the copolymer latex is not limited, and any water-based solvent may be used, and water and various aqueous solutions may be used depending on the intended use.

Here, various additives may be added to the copolymer latex of the present embodiment as necessary, or other latex may be mixed and used as long as the effect is not impaired. For example, a dispersant, an antifoaming agent, an antiaging agent, a water resistant agent, a bactericidal agent, a thickener, a water retaining agent, a printability agent, a lubricant, a cross-linking agent and the like can be added. Further, an alkali-sensitive latex, an organic pigment, a urethane resin latex, an acrylic resin latex, an aqueous chloroprene latex, a vinyl acetate latex and the like can be mixed and used.

[Aqueous adhesive composition]
The copolymer latex of the present embodiment can be used as it is as an aqueous adhesive composition. Further, other (co) polymer latex, for example, diene-based copolymer latex, alkali-sensitive latex, organic pigment, urethane resin latex, acrylic resin-based latex, aqueous chloroprene latex, etc., as long as the effects of the present invention are not impaired. It is also possible to mix and use vinyl acetate latex and the like. Therefore, one of the present embodiments is an aqueous adhesive composition containing the copolymer latex of the present embodiment. Further, in the aqueous adhesive composition of the present embodiment, various additives such as a dispersant, a defoaming agent, an antiaging agent, a water resistant agent, a bactericidal agent, and an increase are required as long as the effect is not impaired. Adhesives, water retention agents, printability agents, lubricants, cross-linking agents and the like can be added.

[Laminate]
The aqueous adhesive composition of the present embodiment is applied to a base material and used to bond the base materials to each other to obtain a laminate. Therefore, one of the present embodiments is a laminate produced by using the aqueous adhesive composition of the present embodiment. The base material is not particularly limited, but can be used for wood, paper, gypsum board, foamed plastic, plastic, metal, ceramic material, glass and the like. Further, it is preferable that one of the base materials is a base material such as wood or paper that absorbs water.

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples as long as the gist of the present invention is not exceeded. The evaluation of each physical property was carried out by the following method.

(1) Gel fraction (toluene insoluble content)
The copolymer latex obtained from Examples and Comparative Examples was dried at 130 ° C. for 30 minutes to obtain a latex film. About 0.5 g of this latex film was precisely weighed. This was mixed with 30 ml of toluene, shaken for 3 hours, filtered through a metal net having a mesh size of 32 μm, and the residue was dried at 130 ° C. for 1 hour and the dry mass was weighed. The ratio of the dry mass of the residue to the mass of the original latex film was defined as the gel fraction (mass%).
Gel fraction (mass%) = (dry mass of residue / mass of latex film) x 100

(2) Number Average Particle Diameter of Copolymer Particles The number average particle diameter of the copolymer particles in the copolymer latex was determined by a particle measuring device (MICROTRACTMUPA150, manufactured by LEED & NORTHRUN) by a light scattering method.

(3) pH of copolymer latex
The value at 25 ° C. was measured using a glass electrode (manufactured by DKK-TOA CORPORATION).

(4) Solid Content of Copolymer Latex 1.0 g of the copolymer latex (sample) obtained from Examples and Comparative Examples was placed in a pre-weighed aluminum dish and heated at 130 ° C. for 1 hour. The mass of the sample before and after heating was measured, and the solid content (mass%) was calculated from the difference.

(5) Viscosity of Copolymer Latex The viscosity at 25 ± 1 ° C. and 60 rpm was measured using a B-type viscometer (manufactured by Toki Sangyo Co., Ltd.).

(6) Mechanical Stability Water was added to the copolymer latex obtained from Examples and Comparative Examples so that the solid content was 30% by mass. 150 g of the copolymer latex having a solid content of 30% by mass was tested for 15 minutes under a load of 30 kg using a marron type mechanical stability tester. The mixture was filtered through a metal net having a mesh size of 32 μm, the agglomerates were dried at 130 ° C. for 1 hour, and the dry mass was weighed. The ratio of the dry mass of the residue to the mass of the copolymer latex excluding water was defined as the agglutination rate (%). The smaller the agglutination rate, the higher the mechanical stability. Mechanical stability was determined according to the following criteria.
Agglutination rate (%) = (dry mass of agglomerates / mass of copolymer latex excluding water) x 100
〇: The agglutination rate was 0.5% or less.
Δ: The agglutination rate was more than 0.5% and less than 2.0%.
X: The agglutination rate was 2.0% or more.

(7) Initial Adhesive Strength A particle board (thickness 12 mm, area 150 mm × 33 mm) was ^{coated with the copolymer latex of Examples and Comparative Examples at a rate of 160 g / m 2,} and after 60 seconds, a medium density fiberboard (MDF) was applied. (Thickness 12 mm, area 150 mm × 50 mm) were bonded together.
The two bonded sheets were ^{pressed at 4 kgf / cm 2} for 15 seconds and then released, and after 60 seconds, the split tensile strength at a tensile speed of 10 mm / min was measured at 23 ° C.

(8) Development time of initial adhesive strength Lauan plywood (thickness 12 mm, area 150 mm × 33 mm) was ^{coated with the copolymer latex of Examples and Comparative Examples at a rate of 160 g / m 2,} and Lauan plywood was immediately attached by hand. I matched it.
Each test piece was allowed to stand after being bonded, and then the split tensile strength was measured at a tensile speed of 10 mm / min and a split tensile strength at 23 ° C. The time when the test intensity became 0.6 N / mm ² or more from the start of standing was measured.

(9) Adhesive strength after curing Lauan plywood (thickness 21 mm, area 30 mm × 30 mm) is ^{coated with the copolymer latex of Examples and Comparative Examples at a rate of 160 g / m 2,} and 60 seconds later, the same Lauan plywood (thickness). 21 mm, area 50 mm × 50 mm) were bonded together.
The two bonded sheets were pressed at 13.3 kgf / cm ² for 15 seconds, released, and cured at 23 ° C. for 3 days. After curing, the plane tensile strength was measured at a tensile speed of 2 mm / min at 23 ° C.

^{(10) Prevention of misalignment immediately after bonding 230 g / m 2 of the} copolymer latex of Examples and Comparative Examples was applied to Lauan plywood (thickness 21 mm, area 50 mm × 50 mm), and gypsum board was immediately bonded by hand. At 23 ° C., the width of the deviation of the Lauan plywood when the gypsum board was erected at 90 degrees after 20 seconds was measured.
◯: The width of the deviation was 1 mm or less.
Δ: The width of the deviation was more than 1 mm and less than 5 mm.
X: The width of the deviation was 5 mm or more.

(11) Variation in coating amount Lauan plywood (thickness 6 mm, area 150 mm × 33 mm) was coated with the ^{copolymer latex of Examples and Comparative Examples at a rate of 160 g / m 2.} Similarly, the copolymer latexs of Examples and Comparative Examples were applied to 30 Lauan plywood sheets so as to have a concentration of 160 g / m ^2. The amount of the copolymer latex applied to the 30 sheets was calculated, and the variation of the test pieces of each of the 30 sheets was confirmed. The variation referred to here means a difference from the coating amount of 160 g / m ^2.
〇: The variation in the coating amount in 30 test pieces was less than ^{30 g / m 2.}
Δ: The variation in the coating amount in the 30 test pieces was 30 g / m ² or more and less than 50 g / m ^2.
X: The variation in the coating amount in the 30 test pieces was 50 g / m ² or more.

(12) Workability The copolymer latex of Examples and Comparative Examples was applied to Lauan plywood (thickness 21 mm, area 50 mm × 50 mm) at a rate of 230 g / m ^2, and gypsum board was immediately attached. At 23 ° C., it was determined whether the adhesive position could be reattached within 5 seconds.
〇: It was possible to re-paste.
Δ: It was difficult to re-paste.

(13) Storage stability The copolymer latex was allowed to stand at room temperature (25 ° C.) for 30 days, and the presence or absence of water separation, sedimentation, aggregation, etc. was visually evaluated and determined as follows.
◯: There was no water separation, sedimentation, or aggregation.
Δ: Slight separation, sedimentation or aggregation was observed.
X: Water separation, sedimentation or aggregation was observed.

(Example 1)
A pressure reactor for mass production equipped with a stirrer, a hot water jacket for adjusting the internal temperature, and a quantitative addition facility for various raw materials was sufficiently replaced with nitrogen, and 63.5 parts by mass of ion-exchanged water and dodecyl were used as raw materials in the initial stage of polymerization. 0.15 parts by mass of sodium benzenesulfonate and 7.1 parts by mass of a polystyrene-based copolymer seed latex (solid content 35% by mass) having an average particle diameter of 40 nm were collectively charged and sufficiently stirred at 75 ° C.
Next, a mixture of the monomer unit and the chain transfer agent shown in Table 1 (hereinafter, abbreviated as “monomer or the like mixture”) was continuously added to the pressure resistant reactor over 5 hours. On the other hand, 5 minutes after the start of addition of the mixture such as monomer, 11.0 parts by mass of ion-exchanged water, 1.0 part by mass of sodium hydroxide, Aqualon HS-1025 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., solid content 25) The addition of an aqueous mixture consisting of 0.8 parts by mass (% by mass) and 0.15 parts by mass of sodium hydroxide was started, and the polymerization reaction was started. This aqueous mixture was added continuously over 6 hours. After the addition of the mixture such as the monomer is completed, the temperature inside the pressure-resistant container is raised to 95 ° C., and after the addition of the aqueous mixture is completed, the polymerization reaction is continued at 95 ° C. for about 1 hour to increase the polymerization conversion rate and polymerize. Was finished. Sodium hydroxide was added to the produced copolymer latex to raise the pH, and unreacted monomers were removed by a steam stripping method.
Next, sodium hydroxide and ion-exchanged water were added to adjust the pH and solid content as shown in Table 1, and then the mixture was filtered through a 200-mesh wire mesh to obtain a copolymer latex A1. Table 1 shows the evaluation results of each physical property of the copolymer latex A1.

(Example 2)
Except that the composition of the mixture such as monomers was changed as shown in Table 1 and the seed latex (solid content 35% by mass) of the polystyrene-based copolymer having an average particle diameter of 40 nm was changed to 2.3 parts by mass. The copolymer latex A2 was produced in the same manner as in Example 1. Table 1 shows the evaluation results of each physical property of the copolymer latex A2.

(Example 3)
A pressure reactor for mass production equipped with a stirrer, a hot water jacket for adjusting the internal temperature, and a quantitative addition facility for various raw materials was sufficiently replaced with nitrogen, and 63.5 parts by mass of ion-exchanged water and dodecyl were used as raw materials in the initial stage of polymerization. 0.15 parts by mass of sodium benzenesulfonate, 0.5 parts by mass of itaconic acid, and 5.9 parts by mass of seed latex (solid content 35% by mass) of a polystyrene-based polymer having an average particle diameter of 40 nm were collectively charged and 75 parts by mass. The mixture was sufficiently stirred at ° C.
Next, a mixture of the monomer units shown in Table 1 other than itaconic acid and the chain transfer agent (hereinafter abbreviated as “mixture such as monomer”) was continuously added to the pressure resistant reactor over 5 hours. bottom. On the other hand, 5 minutes after the start of addition of the mixture such as monomer, 11.0 parts by mass of ion-exchanged water, 1.0 part by mass of sodium hydroxide, Aqualon HS-1025 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., solid content 25) The addition of an aqueous mixture consisting of 0.8 parts by mass (% by mass) and 0.15 parts by mass of sodium hydroxide was started, and the polymerization reaction was started. This aqueous mixture was added continuously over 6 hours. After the addition of the mixture such as the monomer is completed, the temperature inside the pressure-resistant container is raised to 95 ° C., and after the addition of the aqueous mixture is completed, the polymerization reaction is continued at 95 ° C. for about 1 hour to increase the polymerization conversion rate and polymerize. Was finished. Sodium hydroxide was added to the produced copolymer latex to raise the pH, and unreacted monomers were removed by a steam stripping method.
Next, sodium hydroxide and ion-exchanged water were added to adjust the pH and solid content as shown in Table 1, and then the mixture was filtered through a 200-mesh wire mesh to obtain a copolymer latex A3. Table 1 shows the evaluation results of each physical property of the copolymer latex A3.

(Example 4)
Except that the composition of the mixture such as monomers was changed as shown in Table 1 and the seed latex (solid content 35% by mass) of the polystyrene-based copolymer having an average particle diameter of 40 nm was changed to 4.9 parts by mass. The copolymer latex A4 was produced in the same manner as in Example 3. Table 1 shows the evaluation results of each physical property of the copolymer latex A4.

(Example 5)
Copolymer latex A5 was produced in the same manner as in Example 3 except that the composition of the mixture such as monomers was changed as shown in Table 1. Table 1 shows the evaluation results of each physical property of the copolymer latex A5.

(Example 6)
Except that the composition of the mixture such as monomers was changed as shown in Table 1 and the seed latex (solid content 35% by mass) of the polystyrene-based copolymer having an average particle diameter of 40 nm was changed to 4.0 parts by mass. The copolymer latex A6 was produced in the same manner as in Example 3. Table 1 shows the evaluation results of each physical property of the copolymer latex A6.

(Example 7)
Except that the composition of the mixture such as monomers was changed as shown in Table 1 and the seed latex (solid content 35% by mass) of the polystyrene-based copolymer having an average particle diameter of 40 nm was changed to 4.9 parts by mass. The copolymer latex A7 was produced in the same manner as in Example 1. Table 1 shows the evaluation results of each physical property of the copolymer latex A7.

(Example 8)
Except that the composition of the mixture such as monomers was changed as shown in Table 1 and the seed latex (solid content 35% by mass) of the polystyrene-based copolymer having an average particle diameter of 40 nm was changed to 2.4 parts by mass. The copolymer latex A8 was produced in the same manner as in Example 3. Table 1 shows the evaluation results of each physical property of the copolymer latex A8.

(Example 9)
Copolymer latex A9 was produced in the same manner as in Example 3 except that the composition of the mixture such as monomers was changed as shown in Table 1. Table 1 shows the evaluation results of each physical property of the copolymer latex A9.

(Example 10)
Except that the composition of the mixture such as monomers was changed as shown in Table 1 and the seed latex (solid content 35% by mass) of the polystyrene-based copolymer having an average particle diameter of 40 nm was changed to 4.9 parts by mass. The copolymer latex A10 was produced in the same manner as in Example 1. Table 1 shows the evaluation results of each physical property of the copolymer latex A10.

(Example 11)
Copolymer latex A11 was produced in the same manner as in Example 3 except that the composition of the mixture such as monomers was changed as shown in Table 1. Table 1 shows the evaluation results of each physical property of the copolymer latex A11.

(Example 12)
Except that the composition of the mixture such as monomers was changed as shown in Table 1 and the seed latex (solid content 35% by mass) of the polystyrene-based copolymer having an average particle diameter of 40 nm was changed to 4.0 parts by mass. The copolymer latex A12 was produced in the same manner as in Example 1. Table 1 shows the evaluation results of each physical property of the copolymer latex A12.

(Example 13)
A pressure reactor for mass production equipped with a stirrer, a hot water jacket for adjusting the internal temperature, and a quantitative addition facility for various raw materials was sufficiently replaced with nitrogen, and 90.0 parts by mass of ion-exchanged water and dodecyl were used as raw materials in the initial stage of polymerization. 0.15 parts by mass of sodium benzenesulfonate, 0.5 parts by mass of itaconic acid, and 11.7 parts by mass of seed latex (solid content 35% by mass) of a polystyrene-based polymer having an average particle diameter of 40 nm were collectively charged and 75 parts by mass. The mixture was sufficiently stirred at ° C.
Next, a mixture of the monomer unit and the chain transfer agent shown in Table 1 (hereinafter, abbreviated as “monomer or the like mixture”) was continuously added to the pressure resistant reactor over 5 hours. On the other hand, 5 minutes after the start of addition of the mixture such as monomer, 11.0 parts by mass of ion-exchanged water, 1.0 part by mass of sodium hydroxide, Aqualon HS-1025 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., solid content 25) The addition of an aqueous mixture consisting of 0.8 parts by mass (% by mass) and 0.15 parts by mass of sodium hydroxide was started, and the polymerization reaction was started. This aqueous mixture was added continuously over 6 hours. After the addition of the mixture such as the monomer is completed, the temperature inside the pressure-resistant container is raised to 95 ° C., and after the addition of the aqueous mixture is completed, the polymerization reaction is continued at 95 ° C. for about 1 hour to increase the polymerization conversion rate and polymerize. Was finished. Sodium hydroxide was added to the produced copolymer latex to raise the pH, and unreacted monomers were removed by a steam stripping method. The copolymer latex from which the unreacted monomers had been removed was evaporated with water using an evaporator to increase the solid content to 56.0% by mass. Next, sodium hydroxide and ion-exchanged water were added to adjust the pH and solid content as shown in Table 1, and then the mixture was filtered through a 200-mesh wire mesh to obtain a copolymer latex A13. Table 1 shows the evaluation results of each physical property of the copolymer latex A13.

(Comparative Example 1)
Except that the composition of the mixture such as monomers was changed as shown in Table 1 and the seed latex (solid content 35% by mass) of the polystyrene-based copolymer having an average particle diameter of 40 nm was changed to 5.9 parts by mass. The copolymer latex B1 was produced in the same manner as in Example 1. Table 1 shows the evaluation results of each physical property of the copolymer latex B1.

(Comparative Example 2)
Except that the composition of the mixture such as monomers was changed as shown in Table 1 and the seed latex (solid content 35% by mass) of the polystyrene-based copolymer having an average particle diameter of 40 nm was changed to 7.2 parts by mass. The copolymer latex B2 was produced in the same manner as in Example 3. Table 1 shows the evaluation results of each physical property of the copolymer latex B2.

(Comparative Example 3)
Except that the composition of the mixture such as monomers was changed as shown in Table 1 and the seed latex (solid content 35% by mass) of the polystyrene-based copolymer having an average particle diameter of 40 nm was changed to 1.3 parts by mass. The copolymer latex B3 was produced in the same manner as in Example 1. Table 1 shows the evaluation results of each physical property of the copolymer latex B3.

(Comparative Example 4)
Except that the composition of the mixture such as monomers was changed as shown in Table 1 and the seed latex (solid content 35% by mass) of the polystyrene-based copolymer having an average particle diameter of 40 nm was changed to 0.7 parts by mass. The copolymer latex B4 was produced in the same manner as in Example 3. Table 1 shows the evaluation results of each physical property of the copolymer latex B4.

(Comparative Example 5)
Copolymer latex B5 was produced in the same manner as in Example 3 except that the composition of the mixture such as monomers was changed as shown in Table 1. Table 1 shows the evaluation results of each physical property of the copolymer latex B5.

(Comparative Example 6)
Except that the composition of the mixture such as monomers was changed as shown in Table 1 and the seed latex (solid content 35% by mass) of the polystyrene-based copolymer having an average particle diameter of 40 nm was changed to 0.7 parts by mass. The copolymer latex B6 was produced in the same manner as in Example 3. Table 1 shows the evaluation results of each physical property of the copolymer latex B6.

(Comparative Example 7)
Except that the composition of the mixture such as monomers was changed as shown in Table 1 and the seed latex (solid content 35% by mass) of the polystyrene-based copolymer having an average particle diameter of 40 nm was changed to 5.3 parts by mass. The copolymer latex B7 was produced in the same manner as in Example 3. Table 1 shows the evaluation results of each physical property of the copolymer latex B7.

(Comparative Example 8)
Except that the composition of the mixture such as monomers was changed as shown in Table 1 and the seed latex (solid content 10% by mass) of the polystyrene-based copolymer having an average particle diameter of 20 nm was changed to 3.3 parts by mass. The copolymer latex B8 was produced in the same manner as in Example 3. Table 1 shows the evaluation results of each physical property of the copolymer latex B8.

The copolymer latex of the present invention can be used in various applications in which the copolymer latex has been conventionally used, and can be particularly preferably used as an aqueous adhesive. In addition, the copolymer latex of the present invention is also excellent in adhesive strength (initial and after curing), and therefore, in addition, a carpet backing agent, a binder for coated paper, a binder for a battery, a binder for a negative electrode material of a lithium ion battery, various types. It can also be used for paints, various coating agents, and the like.
The copolymer latex of the present invention is also used in industrial fields such as building materials for houses and woodwork furniture, in fields such as building interiors and bathrooms used at construction sites, and solvent-based adhesives widely used in general households. It can also be suitably used in the field of application of the agent.
Since the copolymer latex of the present invention does not contain harmful organic solvents, it does not pollute the environment or harm health, does not pose a risk of fire, etc., has little variation in the coating amount, and has initial adhesiveness after bonding. It is particularly suitable for use as an aqueous adhesive having excellent prevention of slippage immediately after bonding the base materials, excellent adhesive strength after curing, and further excellent storage stability.

Claims (6)

(A) Conjugated diene monomer unit 10.0% by mass or more and 60.0% by mass or less,
(B) Ethylene unsaturated carboxylic acid monomer unit 0.5% by mass or more and 15.0% by mass or less, and
(C) 25.0% by mass or more and 89.5% by mass or less of other monomer units copolymerizable with the conjugated diene-based monomer and / or the ethylene-based carboxylic acid monomer (however, (a)). , (B), and (c) are 100% by mass), which is a copolymer latex containing a copolymer.
The solid content of the copolymer latex is 53.0% by mass or more and 60.0% by mass or less.
The viscosity of the copolymer latex is 300 mPa · s or more and 10000 mPa · s or less.
Copolymer latex. The pH of the copolymer latex is 5.0 or more and 9.0 or less.
The copolymer latex according to claim 1. The time required for the adhesive strength of 0.06 N / mm ² to appear at room temperature is 10 seconds or more and 60 seconds or less.
The copolymer latex according to claim 1 or 2. The gel fraction is 40% by mass or more and 95% by mass or less.
The copolymer latex according to any one of claims 1 to 3. An aqueous adhesive composition comprising the copolymer latex according to any one of claims 1 to 4. A laminate produced by using the aqueous adhesive composition according to claim 5.