JP2022147759A - Diene-based block copolymer, diene-based block copolymer latex, diene-based copolymer latex composition, and molded body - Google Patents

Abstract

To provide: a diene-based block copolymer, a diene-based block copolymer latex, and a diene-based block copolymer latex composition, which can provide a dip-molded film having excellent flexibility, tensile characteristics, and thermal aging resistance even when amounts of use of a vulcanizer and a vulcanization accelerator are reduced or when these are not used; and a molded body having excellent flexibility, tensile characteristics, and thermal aging resistance even when amounts of use of a vulcanizer and a vulcanization accelerator are reduced or when these are not used.SOLUTION: The present invention provides a diene-based block copolymer comprising a polymer block (A) and a diene-based polymer block (B). The diene-based block copolymer contains, when the diene-based block copolymer is set to 100 mass%, 5-30 mass% of the polymer block (A) and 70-95 mass% of the diene-based polymer block (B). The polymer block (A) contains a monomer unit derived from a monomer which, when homopolymerized, can provide a polymer with a glass transition temperature of 80°C or higher. The diene-based block copolymer has tensile strength at break of 14 MPa or more when a film, obtained by dip-molding a diene-based block copolymer latex comprising the diene-based block copolymer, is subjected to a measurement according to JIS K 6251 after heat-treating the film at 130°C for 30 minutes.SELECTED DRAWING: None

Description

The present invention relates to a diene block copolymer, a diene block copolymer latex, a diene block copolymer latex composition, and a molded article.

Natural rubber (NR) gloves, isoprene rubber (IR) gloves, (CR) gloves and the like are widely used as surgical gloves. NR gloves and IR gloves have a low modulus and excellent texture, but NR gloves have type I allergies due to latex proteins, and IR gloves have vulcanization accelerators such as di-tolylguanidine (DOTG). IV-type allergy due to cancer has become a problem, and an allergy-free alternative material is desired. CR gloves do not contain latex protein or DOTG, but due to the effects of zinc dibutyldithiocarbamate (ZDBC) and other vulcanization accelerators that do not react during vulcanization, the modulus increases after product storage and the texture deteriorates. The challenge is to do so.
In addition, in order to obtain the desired mechanical strength, the diene rubber composition contains vulcanizing agents such as sulfur, zinc oxide, and magnesium oxide, and thiuram, dithiocarbamate, thiourea, guanidine, and xanthate. The use of a vulcanization accelerator such as a thiazole system or a thiazole system was essential. Since the vulcanization accelerator is a causative agent of type IV allergy that causes skin diseases such as dermatitis, reduction or non-use of vulcanization accelerators is an important theme. In addition, eliminating the use of vulcanization accelerators not only reduces allergies but also reduces costs, so there is a demand for a rubber composition that exhibits sufficient mechanical strength without using vulcanization accelerators. there is

As a technique related to a latex containing a diene block copolymer, Patent Document 1 discloses an invention relating to an aqueous dispersion containing a block copolymer containing a polymer block composed of a monovinylidene aromatic monomer and a conjugated diene. ing. Further, Patent Document 2 discloses that at least one monovinylarene monomer, an organic monoalkali metal initiator, and at least one conjugated diene monomer are continuously brought into contact under polymerization conditions, followed by a polyfunctional coupling agent. A process for making block copolymers is disclosed which consists of combining to form block copolymers.

JP-A-2003-192869 JP-A-9-169825

As described above, it is possible to obtain a molded article that is allergy-free and has a low modulus and a high tensile strength, even if the amount of vulcanizing agent and vulcanization accelerator used is reduced or not used. Latexes containing conventional diene block copolymers can be used to produce molded articles with low modulus and high tensile strength without the use of vulcanizing agents or vulcanization accelerators. I didn't.

Therefore, according to the present invention, even if the amount of vulcanizing agent or vulcanization accelerator used is reduced or not used, an immersion-molded coating excellent in flexibility, tensile properties, and heat aging resistance can be obtained. Diene-based block copolymer, diene-based block copolymer latex, diene-based block copolymer latex composition, and even if the amount of vulcanizing agent or vulcanization accelerator used is reduced or not used An object of the present invention is to provide a molded article having excellent flexibility, tensile properties, and heat aging resistance.

According to the present invention, a diene-based block copolymer comprising a polymer block (A) and a diene-based polymer block (B), wherein the diene-based block copolymer is the diene-based block copolymer When 100% by mass, the polymer block (A) contains 5 to 30% by mass, the diene polymer block (B) is contained in 70 to 95% by mass, and the polymer block (A) is homopolymerized In some cases, the diene block copolymer contains a monomer unit derived from a monomer from which a polymer having a glass transition temperature of 80 ° C. or higher is obtained, and the diene block copolymer is a diene block copolymer containing the diene block copolymer. Provided is a diene block copolymer having a tensile strength at break of 14 MPa or more measured according to JIS K 6251 after heat-treating a film obtained by dip-molding a coalesced latex at 130° C. for 30 minutes. .

As a result of intensive studies, the present inventor found that in a diene-based block copolymer containing a polymer block (A) and a diene-based polymer block (B), the type of the polymer block (A) and the polymer block A film obtained by dip-molding a diene-based block copolymer latex containing a diene-based block copolymer in a defined blending amount of (A) and a polymer block (B). By adjusting the strength so that it is above a certain level, it is difficult to use conventional diene block copolymers, even if the amount of vulcanizing agents and vulcanization accelerators used is reduced, or these are used. The present inventors have found that a diene-based block copolymer capable of obtaining a dip-molded film having excellent flexibility, tensile properties, and heat aging resistance can be obtained even without the presence of a phenolic solvent, thereby completing the present invention.

Preferably, the polymer block (A) is a diene-based polymer containing at least one monomer unit selected from the group consisting of aromatic vinyl monomer units, methyl methacrylate monomer units, and acrylonitrile monomer units. It is a block copolymer.
Preferably, it is the diene block copolymer described above, wherein the polymer block (A) has a number average molecular weight of 10,000 or more.
Preferably, the polymer block (B) is the above-described diene-based block copolymer having diene-based monomer units and polyfunctional monomer units.
Preferably, the diene-based polymer block (B) contains 0.05 to 10% by mass of the polyfunctional monomer unit when the diene-based polymer block (B) is 100% by mass. It is a diene-based block copolymer described.
Preferably, the polyfunctional monomer is the above-described diene-based block copolymer containing the monomer represented by the chemical formula (1) and the aromatic polyene monomer.

（化学式（１）中、Ｒ_１及びＲ_２はそれぞれ独立して水素、塩素、置換もしくは無置換のアルキル基、置換もしくは無置換のアルケニル基、置換もしくは無置換のアリール基、メルカプト基又は置換もしくは無置換のヘテロシクリル基を表す。Ｗ_１は飽和もしくは不飽和炭化水素基、又は飽和もしくは不飽和環状炭化水素基、又はヘテロ原子を含む飽和もしくは不飽和炭化水素基、環状炭化水素基のいずれかを表す。Ｚ_１は酸素、硫黄もしくは－ＮＲ_０－で表される構造を表す。Ｒ_０は水素、塩素、置換もしくは無置換のアルキル基、アルケニル基、アリール基、メルカプト基、ヘテロシクリル基のいずれかを表す。）

(In chemical formula (1), R ₁ and R ₂ are each independently hydrogen, chlorine, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, a mercapto group, or a substituted or represents an unsubstituted heterocyclyl group, W ₁ is either a saturated or unsaturated hydrocarbon group, a saturated or unsaturated cyclic hydrocarbon group, a saturated or unsaturated hydrocarbon group containing a hetero atom, or a cyclic hydrocarbon group; Z ₁ represents a structure represented by oxygen, sulfur or —NR ₀ —, where R ₀ is hydrogen, chlorine, a substituted or unsubstituted alkyl group, alkenyl group, aryl group, mercapto group or heterocyclyl group; represents.)

According to another aspect of the present invention, there is provided a diene block copolymer latex containing the diene block copolymer described above.
Preferably, the diene-based block copolymer latex is the diene-based block copolymer latex containing 20 to 100% by mass of a toluene-insoluble matter with respect to 100% by mass of the diene-based block copolymer latex. be.
Preferably, the diene block copolymer latex described above has an average particle size of 300 nm or less as measured by a dynamic light scattering method.
Preferably, the diene block copolymer latex described above is used for dip-molded products.

According to another aspect of the present invention, there is provided a diene-based block copolymer latex composition containing the diene-based block copolymer latex described above.
Preferably, in the diene block copolymer latex composition described above, the vulcanizing agent and The diene block copolymer latex composition has a total vulcanization accelerator content of 5% by mass or less.
According to another aspect of the present invention, there is provided a molded article containing the diene block copolymer latex composition described above.

Hereinafter, the present invention will be described in detail by exemplifying embodiments of the present invention. The present invention is not limited in any way by these descriptions. Various features of embodiments of the invention described below can be combined with each other. In addition, the invention is established independently for each characteristic item. In the present specification and claims, the description "A to B" means A or more and B or less.

1. Diene-Based Block Copolymer The diene-based block copolymer according to the present invention comprises a polymer block (A) derived from a monomer that gives a polymer having a glass transition temperature of 80° C. or higher when homopolymerized, and a diene-based monomer. It is a block copolymer containing a diene-based polymer block (B) containing a monomer. The diene-based block copolymer includes those having a structure in which block copolymers are chemically bonded to each other.

1.1 Polymer block (A)
The polymer block (A) is a polymer block derived from a monomer that gives a polymer having a glass transition temperature of 80° C. or higher upon homopolymerization. By using such a monomer, the tensile strength at break of the obtained diene block copolymer is improved. It is preferable to use a monomer that gives a polymer having a glass transition temperature of 85° C. or higher. From the viewpoint of moldability, it is preferable that the monomer gives a polymer having a glass transition temperature of 150° C. or lower, and particularly preferably a monomer that gives a polymer having a glass transition temperature of 120° C. or lower. The glass transition temperature is, for example, 80, 85, 90, 95, 100, 105, 110, 120, 130, 140, 150 ° C., even if it is within the range between any two of the numerical values illustrated here good. In this specification, the glass transition temperature is an extrapolated glass transition end temperature (Teg) measured according to JIS K7121. When the polymer block (A) is a polymer block obtained by polymerizing the monomer (A), the monomer (A) homopolymerizes the monomer A and has a number average molecular weight of 10,000. When a homopolymer (A) of ∼30000 is used, the homopolymer (A) is preferably a monomer having the above glass transition temperature.

The monomer units constituting the polymer block (A) include aromatic vinyl monomer units, methyl methacrylate monomer units, and acrylonitrile monomer units. A unit derived from an aromatic vinyl monomer is preferably used, and a styrene unit is preferably used. The polymer block (A) is a polymer block obtained by copolymerization of these monomers, or a polymer block composed of monomer units copolymerizable with these monomers, as long as the object of the present invention is not impaired. It may be a coalescing block.

The number average molecular weight of the polymer block (A) is preferably 10,000 or more from the viewpoint of tensile properties and moldability of the resulting diene block copolymer. The number average molecular weight of the polymer block (A) can be, for example, 10,000, 15,000, 20,000, 25,000, 30,000, and may be within a range between any two of the numerical values exemplified here. Moreover, the molecular weight distribution of the polymer block (A) is preferably 2.0 or less from the viewpoint of moldability. The molecular weight distribution of the polymer block (A) is, for example, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1 .9, 2.0, and may be in the range between any two of the numbers exemplified herein.
In this specification, the number average molecular weight and the weight average molecular weight are polystyrene equivalent values measured by gel permeation chromatography (GPC) under the measurement conditions described below.
Device name: HLC-8320 (manufactured by Tosoh Corporation)
Column: 3 TSKgel GMHHR-H in series Temperature: 40°C
Detection: Differential refractive index Solvent: Tetrahydrofuran Calibration curve: Prepared using standard polystyrene (PS).

1.2 Diene polymer block (B)
The diene-based polymer block (B) contains diene-based monomer units and is mainly composed of diene-based monomers. The diene polymer block (B) may contain polyfunctional monomer units. Further, the diene-based polymer block (B) is derived from a diene-based monomer unit, a polyfunctional monomer unit, and a monomer copolymerizable therewith, as long as the object of the present invention is not impaired. It may be a polymer block containing a unit to do. The diene-based polymer block (B) preferably contains 90% by mass or more of structural units derived from the diene-based monomer based on 100% by mass of the diene-based polymer block (B).

The content of each structural unit in the diene-based polymer block (B) is not particularly limited, but preferably 90 to 99.95% by mass of diene-based monomer units and 0 of polyfunctional monomer units. 0.05 to 10% by mass. The content of the polyfunctional monomer unit in the diene polymer block (B) is, for example, 0.05, 0.50, 1.00, 2.00, 3.00, 4.00, 5. 00, 6.00, 7.00, 8.00, 9.00, 10.00% by mass, and may be within a range between any two of the numerical values exemplified here.

1.2.1 Diene Monomers Examples of diene monomers according to one embodiment of the present invention include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1, Conjugated diene monomers having 4 to 6 carbon atoms such as 3-pentadiene and chloroprene can be mentioned. The diene-based polymer block (B) according to one embodiment of the present invention has a chloroprene monomer unit content of 50% by mass or less with respect to 100% by mass of the diene-based polymer block (B). can be 30% by mass or less, and can be 10% by mass or less. Moreover, the diene-based polymer block (B) according to one embodiment of the present invention may not contain chloroprene. By keeping the content of the chloroprene monomer units below a certain level, it is possible to suppress the generation of hydrogen chloride under conditions of 100°C or higher and the generation of hydrogen chloride and dioxins during incineration/combustion. . Further, the diene-based monomer according to one embodiment of the present invention is more preferably 1,3-butadiene or isoprene, and particularly preferably 1,3-butadiene. By including butadiene, the specific gravity of the polymer can be adjusted to be higher. From another point of view, butadiene, which is a liquefied gas, is less likely to leave unpolymerized monomers than chloroprene, which is a liquid.

1.2.2 Polyfunctional Monomer The polyfunctional monomer is used to improve the tensile properties and heat aging resistance of the resulting dip-molded coating. A polyfunctional monomer is a compound having two or more radically polymerizable groups in its molecule. From the viewpoints of the flexibility, tensile strength at break, and formability of the obtained dip-molded coating, the monomer represented by the chemical formula (1) and the aromatic polyene monomer are preferably used. Monomers represented by Chemical Formula (1) include 1.9-nonanediol dimethacrylate, 1.9-nonanediol diacrylate, neopentyl glycol dimethacrylate, neopentyl glycol diacrylate, and 1.6-hexanediol. Dimethacrylate, 1,6-hexanediol diacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, polyethylene glycol dimethacrylate and polyethylene glycol diacrylate are particularly preferably used. The aromatic polyene monomer is an aromatic polyene having a carbon number of 10 or more and 30 or less and having a plurality of double bonds (vinyl groups) and one or more aromatic groups, such as o-divinyl Benzene, p-divinylbenzene, m-divinylbenzene, 1,4-divinylnaphthalene, 3,4-divinylnaphthalene, 2,6-divinylnaphthalene, 1,2-divinyl-3,4-dimethylbenzene, 1,3- units derived from aromatic polyene monomers such as divinyl-4,5,8-tributylnaphthalene, preferably one or two of orthodivinylbenzene units, paradivinylbenzene units and metadivinylbenzene units; A mixture of the above is preferably used.

（化学式（１）中、Ｒ_１及びＲ_２はそれぞれ独立して水素、塩素、置換もしくは無置換のアルキル基、置換もしくは無置換のアルケニル基、置換もしくは無置換のアリール基、メルカプト基又は置換もしくは無置換のヘテロシクリル基を表す。Ｗ_１は飽和もしくは不飽和炭化水素基、又は飽和もしくは不飽和環状炭化水素基、又はヘテロ原子を含む飽和もしくは不飽和炭化水素基、環状炭化水素基のいずれかを表す。Ｚ_１は酸素、硫黄もしくは－ＮＲ_０－で表される構造を表す。Ｒ_０は水素、塩素、置換もしくは無置換のアルキル基、アルケニル基、アリール基、メルカプト基、ヘテロシクリル基のいずれかを表す。）

(In chemical formula (1), R ₁ and R ₂ are each independently hydrogen, chlorine, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, a mercapto group, or a substituted or represents an unsubstituted heterocyclyl group, W ₁ is either a saturated or unsaturated hydrocarbon group, a saturated or unsaturated cyclic hydrocarbon group, a saturated or unsaturated hydrocarbon group containing a hetero atom, or a cyclic hydrocarbon group; Z ₁ represents a structure represented by oxygen, sulfur or —NR ₀ —, where R ₀ is hydrogen, chlorine, a substituted or unsubstituted alkyl group, alkenyl group, aryl group, mercapto group or heterocyclyl group; represents.)

1.3 Content of each structural unit in the diene block copolymer ) is 70 to 95% by mass, preferably 5 to 15% by mass for the polymer block (A) and 85 to 95% by mass for the diene polymer block (B). When the polymer block (A) is 5% by mass or more, the obtained diene block copolymer has improved tensile strength at break. When the polymer block (A) is 30% by mass or less, the resulting diene-based block copolymer has improved flexibility. Polymer block (A) is preferably 15% by mass or less. When the diene polymer block (B) is 70% by mass or more, the obtained diene block copolymer has improved flexibility. The diene polymer block (B) is preferably 85% by mass or more. When the diene-based polymer block (B) is 95% by mass or less, the resulting diene-based block copolymer has improved tensile strength at break. When the diene-based block copolymer is 100% by mass, the content of the polymer block (A) contained in the diene-based block copolymer is, for example, 5, 10, 15, 20, 25, or 30% by mass. Yes, and may be in a range between any two of the values exemplified here.
The diene-based block copolymer according to one embodiment of the present invention may contain a polymer block other than the polymer block (A) and the polymer block (B) as long as the object of the present invention is not impaired. However, when the diene block copolymer is 100% by mass, the total content of the polymer block (A) and the polymer block (B) is preferably 80% by mass or more, and is 90% by mass or more. is more preferable.
The diene-based block copolymer according to one embodiment of the present invention may consist of polymer block (A) and polymer block (B), and should not contain other polymer blocks. can also The diene-based block copolymer can also be a polymer block (A)-polymer block (B) diblock copolymer consisting of a polymer block (A) and a polymer block (B).

1.4 Molecular weight of diene-based block copolymer The weight-average molecular weight of the diene-based block copolymer is not particularly limited, but from the viewpoint of moldability, it is preferably 50,000 to 600,000, particularly preferably 10 to 100,000. 500,000.

1.5 Method for Producing Diene-Based Block Copolymer A method for producing a diene-based block copolymer according to the present invention will be described. The polymerization method is not particularly limited, and can be produced by known methods such as solution polymerization, emulsion polymerization, and bulk polymerization, but emulsion polymerization is suitable for obtaining the desired diene block copolymer.

The polymerization method is not particularly limited as long as the desired diene-based block copolymer can be obtained. After the polymerization step 1 for synthesizing the polymer block (A), the polymerization step 2 for synthesizing the diene-based polymer block (B) is performed. It is possible to manufacture by a manufacturing method through a two-stage polymerization process consisting of.

(Polymerization step 1)
Polymerization step 1 will be specifically described. In the polymerization step 1, monomers constituting the polymer block (A) are subjected to living radical emulsion polymerization to synthesize the polymer block (A). The polymer block (A) obtained here preferably has the glass transition temperature described above. The emulsifier used in emulsion polymerization is not particularly limited, but anionic or nonionic emulsifiers are preferred from the viewpoint of emulsion stability. In particular, it is preferable to use an alkali metal rosin acid salt because the resulting diene-based block copolymer can be given appropriate strength to prevent excessive shrinkage and breakage. The concentration of the emulsifier is preferably 5 to 50% by mass with respect to 100% by mass of the monomers constituting the polymer block (A) from the viewpoint of efficient polymerization reaction. As the radical polymerization initiator, known radical polymerization initiators can be used, such as potassium persulfate, benzoyl peroxide, hydrogen peroxide, and azo compounds. The amount of pure water to be added is preferably 100 to 300% by mass with respect to 100% by mass of the monomers constituting the polymer block (A). When the amount of pure water added is 300% by mass or less, the toluene-insoluble content of the obtained diene block copolymer falls within the above-described specific numerical range, and the tensile strength at break is likely to be improved. The polymerization temperature may be appropriately determined according to the type of monomer, but is preferably 10 to 100°C, particularly preferably 20 to 80°C.

(Polymerization step 2)
In the polymerization step 2, the latex containing the polymer block (A) obtained by the living radical emulsion polymerization in the polymerization step 1 is added with pure water, an emulsifier, and a diene-based monomer, and if necessary, a polyfunctional A latex containing the target diene block copolymer can be obtained by adding a monomer and performing emulsion polymerization. The diene-based monomer may be added all at once or in portions. The polymerization temperature in the polymerization step 2 is preferably 10 to 50° C. from the viewpoint of ease of polymerization control. The polymerization reaction is terminated by adding a polymerization terminator. Examples of the polymerization terminator include thiodiphenylamine, 4-tert-butylcatechol, 2,2'-methylenebis-4-methyl-6-tert-butylphenol and the like. Unreacted monomers after completion of the emulsion polymerization can be removed by a conventional method such as distillation under reduced pressure.

The latex containing the diene block copolymer obtained in the polymerization step 2 may be added with a freeze stabilizer, an emulsion stabilizer, a viscosity modifier, an anti-aging agent, a preservative, etc. after polymerization within a range that does not impair the purpose of the present invention. can be optionally added.

(Recovery process)
The method for recovering the diene-based block copolymer from the latex containing the diene-based block copolymer is not particularly limited, and known methods include a method of recovering by immersion in a coagulating liquid, a method of precipitating with a poor solvent such as methanol, and the like. method can be used.

The diene-based block copolymer preferably has a functional group having a structure represented by the following chemical formula (2) or chemical formula (3).

（化学式（２）中、Ｒ_３は水素、塩素、置換もしくは無置換のアルキル基、アルケニル基、アリール基、メルカプト基、ヘテロシクリル基のいずれかを表す。）

(In chemical formula ( ₂ ), R3 represents any one of hydrogen, chlorine, substituted or unsubstituted alkyl group, alkenyl group, aryl group, mercapto group and heterocyclyl group.)

The terminal structure represented by the above chemical formula (2) or chemical formula (3) is introduced into the block copolymer by performing emulsion polymerization in the presence of a known RAFT agent. The compound leading to the structure represented by the above chemical formula (2) is not particularly limited, and general compounds can be used, such as dithiocarbamates and dithioesters. Specifically, benzyl 1-pyrrole carbodithioate (common name: benzyl 1-pyrrole dithiocarbamate), benzylphenyl carbodithioate, 1-benzyl-N,N dimethyl-4-aminodithiobenzoate, 1-benzyl-4- Methoxydithiobenzoate, 1-phenylethylimidazole carbodithioate (common name: 1-phenylethylimidazole dithiocarbamate), benzyl-1-(2-pyrrolidinone) carbodithioate) (common name: benzyl-1-(2-pyrrolidinone) ) dithiocarbamate), benzyl phthalimidyl carbodithioate, (common name: benzyl phthalimidyl dithiocarbamate), 2-cyanoprop-2-yl-1-pyrrole carbodithioate, (common name: 2-cyanoprop-2- yl-1-pyrroledithiocarbamate), 2-cyanobut-2-yl-1-pyrrolecarbodithioate, (common name: 2-cyanobut-2-yl-1-pyrroledithiocarbamate), benzyl-1-imidazolecarbodithio ate, (common name benzyl-1-imidazole dithiocarbamate), 2-cyanoprop-2-yl-N,N-dimethyldithiocarbamate, benzyl-N,N-diethyldithiocarbamate, cyanomethyl-1-(2-pyrrolidone)dithio Carbamate, 2-(ethoxycarbonylbenzyl)prop-2-yl-N,N-diethyldithiocarbamate, 1-phenylethyldithiobenzoate, 2-phenylprop-2-yldithiobenzoate, 1-acetate-1-yl-ethyl dithiobenzoate, 1-(4-methoxyphenyl)ethyldithiobenzoate, benzyldithioacetate, ethoxycarbonylmethyldithioacetate, 2-(ethoxycarbonyl)prop-2-yldithiobenzoate, 2-cyanoprop-2-yldithiobenzoate, tert-butyl dithiobenzoate, 2,4,4-trimethylpent-2-yl dithiobenzoate, 2-(4-chlorophenyl)-prop-2-yl dithiobenzoate, 3-vinylbenzyl dithiobenzoate, 4-vinylbenzyl dithiobenzoate , benzyldiethoxyphosphinyldithioformate, tert-butyl trithioperbenzoate, 2-phenylprop-2-yl-4-chlorodithiobenzoate, naphthalene-1-carboxylic acid-1-methyl-1-phenyl-ethyl ester , 4-cyano-4-methyl-4-thiobenzylsulfanylbutyrate, dibenzyltetrathioterephthalate, carboxymethyldithiobenzoate, poly(ethylene oxide) with dithiobenzoate end groups, 4-cyano-4-methyl-4- Poly(ethylene oxide) with thiobenzylsulfanylbutyric acid end groups, 2-[(2-phenylethanethiol)sulfanyl]propanoic acid, 2-[(2-phenylethanethiol)sulfanyl]succinic acid, 3,5- dimethyl-1H-pyrazole-1-carbodithioate potassium, cyanomethyl-3,5-dimethyl-1H-pyrazole-1-carbodithioate, cyanomethylmethyl-(phenyl)dithiocarbamate, benzyl-4-chlorodithiobenzoate, phenyl methyl-4-chlorodithiobenzoate, 4-nitrobenzyl-4-chlorodithiobenzoate, phenylprop-2-yl-4-chlorodithiobenzoate, 1-cyano-1-methylethyl-4-chlorodithiobenzoate, 3-chloro -2-butenyl-4-chlorodithiobenzoate, 2-chloro-2-butenyldithiobenzoate, benzyldithioacetate, 3-chloro-2-butenyl-1H-pyrrole-1-dithiocarboxylic acid, 2-cyanobutane-2- yl 4-chloro-3,5-dimethyl-1H-pyrazole-1-carbodithioate, cyanomethylmethyl(phenyl)carbamodithioate. Among these, benzyl 1-pyrrole carbodithioate and benzylphenyl carbodithioate are particularly preferably used.

The compound leading to the structure represented by the above chemical formula (3) is not particularly limited, and general compounds can be used, for example, 2-cyano-2-propyldodecyltrithiocarbonate, dibenzyl Trithiocarbonate, butylbenzyltrithiocarbonate, 2-[[(butylthio)thioxomethyl]thio]propionic acid, 2-[[(dodecylthio)thioxomethyl]thio]propionic acid, 2-[[(butylthio)thioxomethyl]thio ] succinic acid, 2-[[(dodecylthio)thioxomethyl]thio]succinic acid, 2-[[(dodecylthio)thioxomethyl]thio]-2-methylpropionic acid, 2,2′-[carbonothioyl bis(thio)] Bis[2-methylpropionic acid], 2-amino-1-methyl-2-oxoethylbutyltrithiocarbonate, benzyl 2-[(2-hydroxyethyl)amino]-1-methyl-2-oxoethyltrithio Carbonate, trithiocarbonate such as 3-[[[(tert-butyl)thio]thioxomethyl]thio]propionic acid, cyanomethyldodecyltrithiocarbonate, diethylaminobenzyltrithiocarbonate, dibutylaminobenzyltrithiocarbonate types are mentioned. Among these, dibenzyltrithiocarbonate and butylbenzyltrithiocarbonate are particularly preferably used.

The diene-based copolymer according to one embodiment of the present invention has at least It is preferable to have any one structure.

2. Diene-Based Block Copolymer Latex The diene-based block copolymer latex according to one embodiment of the present invention contains the diene-based block copolymer described above. The diene-based block copolymer latex according to one embodiment of the present invention is preferably for dip molding. The latex according to one embodiment of the present invention can be immersed in a coagulation liquid and molded to obtain an immersion-molded body. The dip-molded article can be suitably used for gloves, balloons, catheters, boots, and the like.

The latex of the present embodiment can be produced by using the liquid at the end of the polymerization synthesized by the emulsion polymerization described in the production method of the diene block copolymer as a latex, or by using the recovered diene block copolymer as an emulsifier. However, the method of using the liquid synthesized by emulsion polymerization at the end of polymerization as it is as latex is preferable because latex can be obtained easily. is.

2.1 Toluene-insoluble content of diene-based block copolymer latex The diene-based block copolymer latex according to one embodiment of the present invention has a toluene-insoluble content with respect to 100% by mass of the diene-based block copolymer latex. It preferably contains 20 to 100% by mass, more preferably 70 to 100% by mass. It is considered that when the toluene-insoluble content is at least the above lower limit, the structure in which the block copolymers are chemically bonded to each other is included, thereby improving the tensile strength at break. The toluene insoluble content can be, for example, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100% by mass, where It may be in a range between any two of the numerical values given. In the present specification, the toluene-insoluble matter refers to the weight obtained by dissolving a freeze-dried latex containing a diene-based block copolymer in toluene, separating the gel content using a 200-mesh wire mesh after centrifugation, and drying it. is measured and obtained from the following formula.
(mass of solid obtained by separating and drying gel content)/(mass of solid obtained by freeze-drying latex containing diene-based block copolymer) x 100
The toluene-insoluble matter controls the type and amount of the raw material compounded during the polymerization of the diene block copolymer and the polymerization conditions, and controls the type and amount of the polymer block, for example, the type and amount of the polyfunctional monomer unit. , and can be adjusted by controlling the type, amount, and structure of the functional group derived from the RAFT agent or the like.

2.2 Average particle size of diene block copolymer latex The average particle size of the diene block copolymer latex measured by the dynamic light scattering method is 300 nm or less from the viewpoint of the mechanical stability of the latex. It is preferably 250 nm or less, and even more preferably 200 nm or less. The lower limit can be, for example, 100 nm or more. The average particle size is, for example, 100, 120, 140, 150, 160, 170, 180, 190, 200, 220, 240, 260, 280, 300 nm, and ranges between any two of the numerical values exemplified here may be within
In this specification, the average particle size is an average particle size measured by a dynamic light scattering method and calculated by a photon correlation method. The average particle size can be adjusted by controlling the type and amount of the diene-based block copolymer latex compounded and the production conditions. For example, it can be adjusted by the stirring conditions during emulsion polymerization.

2.3 Mechanical stability of diene-based block copolymer latex It is more preferably 1% by mass or less, and even more preferably 1% by mass or less. The mechanical stability of the diene block copolymer latex can be evaluated by the measuring method described in Examples. The mechanical stability can be adjusted by controlling the type and amount of the diene block copolymer latex compounded and the production conditions. For example, the average particle size of the diene block copolymer latex is controlled. can be adjusted by

2.4 Tensile properties of diene-based block copolymer latex The diene-based block copolymer of the present embodiment contains a diene-based block copolymer. The molded coating has a tensile strength at break of 14 MPa or more measured according to JIS K 6251 after heat treatment at 130 ° C. for 30 minutes, and an unvulcanized immersion molded coating containing no vulcanizing agent or vulcanization accelerator. can give The unvulcanized dip-molded coating is flexible and exhibits sufficient mechanical strength without containing a vulcanizing agent or a vulcanization accelerator. The tensile strength at break is more preferably 15 MPa or more, even more preferably 16 MPa or more, even more preferably 17 MPa or more, and particularly preferably 20 MPa or more. Although the upper limit is not particularly limited, it is, for example, 30 MPa or less. The tensile strength at break can be, for example, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 MPa, where It may be in a range between any two of the numerical values given.

The diene-based block copolymer according to one embodiment of the present invention is a dip-molded film obtained by dip-molding a diene-based block copolymer latex containing a diene-based block copolymer at 30° C. for 30 minutes. After the heat treatment, the tensile strength at break measured in accordance with JIS K 6251 after a heat aging test at 100 ° C. for 22 hours is preferably 14 MPa or more, and preferably 15 MPa or more. is more preferably 16 MPa or more, even more preferably 17 MPa or more, and particularly preferably 20 MPa or more. Although the upper limit is not particularly limited, it is, for example, 30 MPa or less.

Further, the diene block copolymer of the present embodiment is prepared by heat-treating a dip-molded film obtained by dip-molding a diene block copolymer latex containing a diene block copolymer at 130° C. for 30 minutes. The elongation at break measured later according to JIS K 6251 is preferably 900% or more, more preferably 905% or more, and even more preferably 910% or more. Although the upper limit is not particularly limited, it is, for example, 1300% or less.

The diene-based block copolymer according to one embodiment of the present invention is a dip-molded film obtained by dip-molding a diene-based block copolymer latex containing a diene-based block copolymer at 30° C. for 30 minutes. After the heat treatment, the elongation at break measured in accordance with JIS K 6251 after a heat aging test at 100° C. for 22 hours is preferably 900% or more, preferably 905% or more. More preferably, it is even more preferably 910% or more. Although the upper limit is not particularly limited, it is, for example, 1300% or less.

The diene-based block copolymer of the present embodiment is obtained by dip-molding a diene-based block copolymer latex containing a diene-based block copolymer, followed by heat treatment at 130°C for 30 minutes. The 500% elongation modulus measured according to K6251 is preferably 3.0 MPa or less, more preferably 2.9 MPa or less, and even more preferably 2.8 MPa or less. Although the lower limit is not particularly limited, it is, for example, 1.0 MPa or more.

The diene-based block copolymer according to one embodiment of the present invention is a dip-molded film obtained by dip-molding a diene-based block copolymer latex containing a diene-based block copolymer at 30° C. for 30 minutes. After the heat treatment, furthermore, after performing a heat aging test under the conditions of 100 ° C. for 22 hours, the modulus at 500% elongation measured in accordance with JIS K 6251 is preferably 3.0 MPa or less, and 2.9 MPa. It is more preferably 2.8 MPa or less, and even more preferably 2.8 MPa or less. Although the lower limit is not particularly limited, it is, for example, 1.0 MPa or more.
The dip-molded coating can be obtained by the method described in the Examples, and the dip-molded coating can be formed without using a vulcanizing agent and a vulcanization accelerator.

In order to adjust the tensile strength at break, elongation at break, and modulus at 500% elongation of the dip-molded coating obtained by dip-molding a diene-based block copolymer latex containing a diene-based block copolymer, the diene By adjusting the content of the polyfunctional monomer unit contained in the polymer block (B) or the content of the diene polymer block (B) in the diene block copolymer, the diene polymer block (B) Adjusting the toluene-insoluble content by changing the polymerization temperature and polymerization rate during polymerization, and adjusting the type and amount of functional groups introduced by polymerization in the presence of the RAFT agent described later. do it.

The dip-molded coating obtained from the diene-based block copolymer latex of the present embodiment may contain a vulcanizing agent or a vulcanization accelerator. When the dip-molded coating contains a vulcanizing agent and a vulcanization accelerator, the total content thereof should be 5% by mass or less with respect to 100% by mass of the diene-based block copolymer latex contained in the dip-molded coating. It is more preferably 1% by mass or less, more preferably 0.1% by mass. However, the unvulcanized dip-molded film has sufficient mechanical strength even without containing a vulcanizing agent and a vulcanization accelerator. Those containing no vulcanization accelerator are preferred.

3. Diene-Based Block Copolymer Latex Composition A diene-based block copolymer latex composition according to one embodiment of the present invention includes a diene-based block copolymer latex containing the above-described diene-based block copolymer.

3.2 Components Contained in Diene Block Copolymer Latex Composition The diene block copolymer latex composition according to the present embodiment contains a diene block copolymer. Raw materials other than the diene-based block copolymer are not particularly limited, and can be appropriately selected according to the purpose and application. Raw materials that can be contained in latex compositions and rubber compositions containing diene block copolymers include, for example, vulcanizing agents, vulcanization accelerators, fillers or reinforcing agents, plasticizers, processing aids and lubricants, aging Examples include inhibitors and silane coupling agents.

The latex composition of this embodiment may contain a vulcanizing agent or vulcanization accelerator. When the latex composition according to one embodiment of the present invention contains a vulcanizing agent and/or a vulcanization accelerator, the total content of the vulcanizing agent and the vulcanization accelerator is With respect to the diene block copolymer latex contained in the diene block copolymer latex composition, it can be 5% by mass or less, more preferably 1% by mass or less, and 0.1% by mass. is more preferable. However, the latex composition containing the diene block copolymer of the present embodiment develops sufficient mechanical strength without vulcanization. Therefore, from the viewpoint of allergenicity reduction and cost reduction, it is preferable to use one that does not contain a vulcanizing agent or a vulcanization accelerator.

As anti-aging agents to improve heat resistance, a primary anti-aging agent that captures radicals and prevents autoxidation, and a secondary anti-aging agent that detoxifies hydroperoxide, which are used in ordinary rubber applications, are added. can do. These antioxidants can be added in a proportion of 0.1 parts by mass or more and 10 parts by mass or less, preferably 2 parts by mass or more and 5 parts by mass or less, with respect to 100 parts by mass of the latex component in the latex composition. is in the range of These antioxidants can be used alone or in combination of two or more. Examples of primary anti-aging agents include phenol-based anti-aging agents, amine-based anti-aging agents, acrylate-based anti-aging agents, imidazole-based anti-aging agents, metal carbamates, and waxes. Moreover, as a secondary anti-aging agent, a phosphorus-based anti-aging agent, a sulfur-based anti-aging agent, an imidazole-based anti-aging agent, etc. can be mentioned. Non-limiting examples of antioxidants include N-phenyl-1-naphthylamine, alkylated diphenylamine, octylated diphenylamine, 4,4′-bis(α,α-dimethylbenzyl)diphenylamine, p-(p -toluenesulfonylamido)diphenylamine, N,N'-di-2-naphthyl-p-phenylenediamine, N,N'-diphenyl-p-phenylenediamine, N-phenyl-N'-isopropyl-p-phenylenediamine, N -phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine, N-phenyl-N'-(3-methacryloyloxy-2-hydroxypropyl)-p-phenylenediamine, 1,1,3- Tris-(2-methyl-4-hydroxy-5-t-butylphenyl)butane, 4,4′-butylidenebis-(3-methyl-6-t-butylphenol), 2,2-thiobis(4-methyl-6 -t-butylphenol), 7-octadecyl-3-(4′-hydroxy-3′,5′-di-t-butylphenyl)propionate, tetrakis-[methylene-3-(3′,5′-di-t -butyl-4′-hydroxyphenyl)propionate]methane, pentaerythritol-tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], triethylene glycol-bis[3-(3- t-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,4- Bis(n-octylthio)-6-(4-hydroxy-3,5-di-t-butylanilino)-1,3,5-triazine, tris-(3,5-di-t-butyl-4-hydroxybenzyl )-isocyanurate, 2,2-thio-diethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], N,N'-hexamethylenebis(3,5-di- t-butyl-4-hydroxy)-hydrocinnamide, 2,4-bis[(octylthio)methyl]-o-cresol, 3,5-di-t-butyl-4-hydroxybenzyl-phosphonate-diethyl ester, tetrakis [methylene (3,5-di-t-butyl-4-hydroxyhydrocinnamate)]methane, octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate Ter and 3,9-bis[2-{3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy}-1,1-dimethylethyl]-2,4,8,10-tetra oxaspiro[5.5]undecane, tris(nonylphenyl)phosphite, tris(mixed mono- and di-nonylphenyl)phosphite, diphenyl mono(2-ethylhexyl)phosphite, diphenyl monotridecyl phosphite, Diphenyl isodecyl phosphite, diphenyl isooctyl phosphite, diphenyl nonylphenyl phosphite, triphenyl phosphite, tris(tridecyl) phosphite, triisodecyl phosphite, tris(2-ethylhexyl) phosphite, tris (2,4-di-t-butylphenyl)phosphite, tetraphenyldipropylene glycol diphosphite, tetraphenyltetra(tridecyl)pentaerythritol tetraphosphite, 1,1,3-tris(2-methyl-4) -di-tridecylphosphite-5-t-butylphenyl)butane, 4,4'-butylidenebis-(3-methyl-6-t-butyl-di-tridecylphosphite), 2,2'-ethylidenebis (4,6-di-t-butylphenol)fluorophosphite, 4,4'-isopropylidene-diphenolalkyl (C12-C15) phosphite, cyclic neopentanetetraylbis(2,4-di-t-butyl phenylphosphite), cyclic neopentanetetraylbis(2,6-di-t-butyl-4-phenylphosphite), cyclic neopentanetetraylbis(nonylphenylphosphite), bis(nonylphenyl)pentaerythritol di phosphite, dibutyl hydrogen phosphite, distearyl pentaerythritol diphosphite and hydrogenated bisphenol A pentaerythritol phosphite polymer, 2-mercaptobenzimidazole, butylated reaction product of p-cresol and dicyclopentadiene, etc. .

The latex composition can be produced according to conventional methods using known machines and devices.

4. Molded Article The molded article according to one embodiment of the present invention contains the above diene block copolymer latex composition, and is preferably made of the above diene block copolymer latex composition.
Components that may be included in the molded article according to one embodiment of the present invention are as described above for the diene-based block copolymer latex composition. Further, the properties that the molded article according to one embodiment of the present invention may have are as described above in the tensile properties of the diene-based block copolymer latex.

EXAMPLES The present invention will be described below with reference to examples and comparative examples, but these are merely illustrative and do not limit the scope of the present invention.

(Example 1)
(Polymerization Step 1) Synthesis of Polymer Block (A-1) Polymerization was carried out using an autoclave with a capacity of 10 L and equipped with a stirrer and a jacket for heating and cooling. 4666 g of pure water, 224 g of disproportionated potassium rosinate (manufactured by Harima Kasei Co., Ltd.), 36.4 g of potassium hydroxide, sodium salt of β-naphthalenesulfonic acid formalin condensate (manufactured by Kao Corporation, trade name: Demoll N) 18.7 g , 350 g of a styrene monomer and 6.07 g of butylbenzyl trithiocarbonate were charged, the internal temperature was raised to 80° C., and the mixture was stirred at 200 rpm under a nitrogen stream. 3.82 g of 2,2′-azobis[2-(2-imidazolin-2-yl)propane]dihydrogen chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name: VA-044) was added as a polymerization initiator. Polymerization started. 20 ml of the obtained latex was sampled for physical property measurement, and the remaining latex was used in polymerization step 2.

The sampled latex was mixed with a large amount of methanol to precipitate a resin component, filtered and dried to obtain a sample of polymer block (A-1). From the obtained sample, the number average molecular weight, molecular weight distribution and glass transition temperature of the polymer block (A) were determined by analysis. The analysis results are shown in Table 1. Methods for measuring "number average molecular weight", "molecular weight distribution" and "glass transition temperature" will be described later.

(Polymerization step 2) Synthesis of diene-based polymer block (B-1) After the polymerization step 1, when the internal temperature was lowered to 45°C, the nitrogen stream was stopped, and nitrogen was used to reduce the internal pressure of the reaction vessel to 0.5°C. The pressure was increased to 6 MPaG. Polymerization was carried out by slowly adding 4480 g of butadiene monomer and 91.4 g of 1,9-nonanediol dimethacrylate over 2 hours. When the polymerization rate of the butadiene monomer reaches 80%, the polymerization is stopped by adding a 10% by weight aqueous solution of N,N-diethylhydroxylamine as a polymerization terminator, and the unreacted butadiene monomer is removed by distillation under reduced pressure. removed the body. For physical property measurement, 20 ml of the obtained latex was sampled, and the remaining latex was used to prepare a film for evaluation.

A portion of the sampled latex was used to measure the average particle size of the latex and the mechanical stability of the latex. The analysis results are shown in Table 1. In addition, the measuring method will be described later. The sampled latex was mixed with a large amount of methanol to precipitate a resin component, filtered and dried to obtain a diene block copolymer sample. The content (% by mass) of the polymer block (A-1) of the butadiene-based block copolymer and the diene-based polymer block (B-1) was determined from the resulting sample by analysis. The analysis results are shown in Table 1. In addition, the measuring method will be described later. Also, the toluene-insoluble matter was obtained from the sampled latex. The analysis results are shown in Table 1. The measuring method will be described later.

(Example 2)
(Polymerization Step 1) Synthesis of Polymer Block (A-2) Polymerization was carried out using an autoclave with a capacity of 10 L, equipped with a stirrer and a jacket for heating and cooling. 3333 g of pure water, 160 g of disproportionated potassium rosinate (manufactured by Harima Kasei Co., Ltd.), 26.0 g of potassium hydroxide, sodium salt of β-naphthalenesulfonic acid formalin condensate (manufactured by Kao Corporation, trade name: Demoll N) 13.3 g , 250 g of a styrene monomer, and 4.33 g of butylbenzyl trithiocarbonate were charged, the internal temperature was raised to 80° C., and the mixture was stirred at 200 rpm under a nitrogen stream. As a polymerization initiator, 2.73 g of 2,2'-azobis[2-(2-imidazolin-2-yl)propane]dihydrogen chloride (trade name: VA-044, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added to polymerize. started. 20 ml of the obtained latex was sampled for physical property measurement, and the remaining latex was used in polymerization step 2. The number average molecular weight, molecular weight distribution, and glass transition temperature of the polymer block (A-2) were determined by analysis in the same manner as in Example 1. Table 1 shows the analysis results.

(Polymerization step 2) Synthesis of diene-based polymer block (B-2) After the polymerization step 1, when the internal temperature was lowered to 45°C, the nitrogen stream was stopped, and nitrogen was used to reduce the internal pressure of the reaction vessel to 0.5°C. The pressure was increased to 6 MPaG. Polymerization was carried out by slowly adding 5584 g of butadiene monomer and 114.0 g of 1.9-nonanediol dimethacrylate over 2 hours. When the polymerization rate of the butadiene monomer reaches 80%, the polymerization is stopped by adding a 10% by weight aqueous solution of N,N-diethylhydroxylamine as a polymerization terminator, and the unreacted butadiene monomer is removed by distillation under reduced pressure. removed the body. For physical property measurement, 20 ml of the obtained latex was sampled, and the remaining latex was used to prepare a film for evaluation. The average particle size of the latex, the mechanical stability of the latex, and the content (% by mass) of the polymer block (A-2) of the diene-based block copolymer and the diene-based polymer block (B-2) were measured in Example 1. It was obtained by the same analysis as Also, the toluene-insoluble matter was determined from the sampled latex. Table 1 shows the analysis results.

(Example 3)
(Polymerization Step 1) Synthesis of Polymer Block (A-3) Polymerization was carried out using an autoclave with a capacity of 10 L, equipped with a stirrer and a jacket for heating and cooling. 5733 g of pure water, 275 g of disproportionated potassium rosinate (manufactured by Harima Kasei Co., Ltd.), 44.7 g of potassium hydroxide, sodium salt of β-naphthalenesulfonic acid formalin condensate (manufactured by Kao Corporation, trade name: Demoll N) 22.9 g , 430 g of a styrene monomer and 7.45 g of butylbenzyl trithiocarbonate were charged, the internal temperature was raised to 80° C., and the mixture was stirred at 200 rpm under a nitrogen stream. 4.69 g of 2,2′-azobis[2-(2-imidazolin-2-yl)propane]dihydrogen chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name: VA-044) is added as a polymerization initiator to polymerize. started. 20 ml of the obtained latex was sampled for physical property measurement, and the remaining latex was used in polymerization step 2. The number average molecular weight, molecular weight distribution, and glass transition temperature of the polymer block (A-3) were determined by analysis in the same manner as in Example 1. Table 1 shows the analysis results.

(Polymerization step 2) Synthesis of butadiene-based polymer block (B-3) After the polymerization step 1, when the internal temperature decreased to 45°C, the nitrogen flow was stopped, and nitrogen was used to reduce the internal pressure of the reaction vessel to 0.5°C. The pressure was raised to 6 MPaG. 3094 g of butadiene monomer and 63.1 g of 1,9-nonanediol dimethacrylate were slowly added over 2 hours to carry out polymerization. When the polymerization rate of the butadiene monomer reaches 80%, the polymerization is stopped by adding a 10% by weight aqueous solution of N,N-diethylhydroxylamine as a polymerization terminator, and the unreacted butadiene monomer is removed by distillation under reduced pressure. removed the body. For physical property measurement, 20 ml of the obtained latex was sampled, and the remaining latex was used to prepare a film for evaluation. The average particle size of the latex, the mechanical stability of the latex, and the content (% by mass) of the polymer block (A-3) of the diene-based block copolymer and the diene-based polymer block (B-3) were measured in Example 1. It was obtained by the same analysis as Also, the toluene-insoluble matter was determined from the sampled latex. Table 1 shows the analysis results.

(Example 4)
(Polymerization Step 1) Synthesis of Polymer Block (A-4) Polymerization was carried out using an autoclave with a capacity of 10 L, equipped with a stirrer and a jacket for heating and cooling. 4666 g of pure water, 224 g of disproportionated potassium rosinate (manufactured by Harima Kasei Co., Ltd.), 36.4 g of potassium hydroxide, sodium salt of β-naphthalenesulfonic acid formalin condensate (manufactured by Kao Corporation, trade name: Demoll N) 18.7 g , 350 g of a styrene monomer and 6.07 g of butylbenzyl trithiocarbonate were charged, the internal temperature was raised to 80° C., and the mixture was stirred at 200 rpm under a nitrogen stream. 3.82 g of 2,2′-azobis[2-(2-imidazolin-2-yl)propane]dihydrogen chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name: VA-044) is added as a polymerization initiator to polymerize. started. 20 ml of the obtained latex was sampled for physical property measurement, and the remaining latex was used in polymerization step 2. The number average molecular weight, molecular weight distribution and glass transition temperature of the polymer block (A-4) were determined by analysis in the same manner as in Example 1. Table 1 shows the analysis results.

(Polymerization step 2) Synthesis of butadiene-based polymer block (B-4) After the polymerization step 1, when the internal temperature was lowered to 45°C, the nitrogen stream was stopped, and nitrogen was used to reduce the internal pressure of the reactor to 0.5°C. The pressure was increased to 6 MPaG. Polymerization was carried out by slowly adding 4480 g of butadiene monomer and 91.4 g of 1.9-nonanediol diacrylate over 2 hours. When the polymerization rate of the butadiene monomer reaches 80%, the polymerization is stopped by adding a 10% by weight aqueous solution of N,N-diethylhydroxylamine as a polymerization terminator, and the unreacted butadiene monomer is removed by distillation under reduced pressure. removed the body. For physical property measurement, 20 ml of the obtained latex was sampled, and the remaining latex was used to prepare a film for evaluation. The average particle size of the latex, the mechanical stability of the latex, and the content (% by mass) of the polymer block (A-4) of the diene-based block copolymer and the diene-based polymer block (B-4) were measured in Example 1. It was obtained by the same analysis as Also, the toluene-insoluble matter was obtained from the sampled latex. Table 1 shows the analysis results.

(Example 5)
(Polymerization Step 1) Synthesis of Polymer Block (A-5) Polymerization was carried out using an autoclave with a capacity of 10 L, equipped with a stirrer and a jacket for heating and cooling. 4666 g of pure water, 224 g of disproportionated potassium rosinate (manufactured by Harima Kasei Co., Ltd.), 36.4 g of potassium hydroxide, sodium salt of β-naphthalenesulfonic acid formalin condensate (manufactured by Kao Corporation, trade name: Demoll N) 18.7 g , 350 g of a styrene monomer and 6.07 g of butylbenzyl trithiocarbonate were charged, the internal temperature was raised to 80° C., and the mixture was stirred at 200 rpm under a nitrogen stream. 3.82 g of 2,2′-azobis[2-(2-imidazolin-2-yl)propane]dihydrogen chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name: VA-044) is added as a polymerization initiator to polymerize. started. 20 ml of the obtained latex was sampled for physical property measurement, and the remaining latex was used in polymerization step 2. The number average molecular weight, molecular weight distribution, and glass transition temperature of the polymer block (A-5) were determined by analysis in the same manner as in Example 1. The analysis results are shown in Table 1.

(Polymerization step 2) Synthesis of butadiene-based polymer block (B-5) After the polymerization step 1, when the internal temperature was lowered to 45°C, the nitrogen stream was stopped, and nitrogen was used to reduce the internal pressure of the reactor to 0.5°C. The pressure was raised to 6 MPaG. 4480 g of butadiene monomer and 91.4 g of Light Ester EG (manufactured by Kyoeisha Chemical Co., Ltd.), which is ethylene glycol diacrylate, were slowly added over 2 hours to carry out polymerization. When the polymerization rate of the butadiene monomer reaches 80%, the polymerization is stopped by adding a 10% by weight aqueous solution of N,N-diethylhydroxylamine as a polymerization terminator, and the unreacted butadiene monomer is removed by distillation under reduced pressure. removed the body. For physical property measurement, 20 ml of the obtained latex was sampled, and the remaining latex was used to prepare a film for evaluation. The average particle size of the latex, the mechanical stability of the latex, and the content (% by mass) of the polymer block (A-5) of the diene-based block copolymer and the diene-based polymer block (B-5) were measured in Example 1. It was obtained by the same analysis as Also, the toluene-insoluble matter was obtained from the sampled latex. The analysis results are shown in Table 1.

(Example 6)
(Polymerization Step 1) Synthesis of Polymer Block (A-6) Polymerization was carried out using an autoclave with a capacity of 10 L, equipped with a stirrer and a jacket for heating and cooling. 4666 g of pure water, 224 g of disproportionated potassium rosinate (manufactured by Harima Kasei Co., Ltd.), 36.4 g of potassium hydroxide, sodium salt of β-naphthalenesulfonic acid formalin condensate (manufactured by Kao Corporation, trade name: Demoll N) 18.7 g , 350 g of a styrene monomer and 6.07 g of butylbenzyl trithiocarbonate were charged, the internal temperature was raised to 80° C., and the mixture was stirred at 200 rpm under a nitrogen stream. 3.82 g of 2,2′-azobis[2-(2-imidazolin-2-yl)propane]dihydrogen chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name: VA-044) is added as a polymerization initiator to polymerize. started. 20 ml of the obtained latex was sampled for physical property measurement, and the remaining latex was used in polymerization step 2. The number average molecular weight, molecular weight distribution and glass transition temperature of the polymer block (A-6) were determined by analysis in the same manner as in Example 1. The analysis results are shown in Table 1.

(Polymerization step 2) Synthesis of butadiene-based polymer block (B-6) After the polymerization step 1, when the internal temperature was lowered to 45°C, the nitrogen gas flow was stopped, and nitrogen was used to reduce the internal pressure of the reactor to 0.5°C. The pressure was raised to 6 MPaG. Polymerization was carried out by slowly adding 4480 g of butadiene monomer and 93.3 g of divinylbenzene over 2 hours. When the polymerization rate of the butadiene monomer reaches 80%, the polymerization is stopped by adding a 10% by weight aqueous solution of N,N-diethylhydroxylamine as a polymerization terminator, and the unreacted butadiene monomer is removed by distillation under reduced pressure. removed the body. For physical property measurement, 20 ml of the obtained latex was sampled, and the remaining latex was used to prepare a film for evaluation. The average particle size of the latex, the mechanical stability of the latex, and the content (% by mass) of the polymer block (A-6) of the diene block copolymer and the diene polymer block (B-6) were measured in Example 1. It was obtained by the same analysis as Also, the toluene-insoluble matter was obtained from the sampled latex. The analysis results are shown in Table 1.

(Example 7)
(Polymerization Step 1) Synthesis of Polymer Block (A-7) Polymerization was carried out using an autoclave with a capacity of 10 L, equipped with a stirrer and a jacket for heating and cooling. 5450 g of pure water, 262 g of disproportionated potassium rosinate (manufactured by Harima Kasei Co., Ltd.), 42.5 g of potassium hydroxide, sodium salt of β-naphthalenesulfonic acid formalin condensate (manufactured by Kao Corporation, trade name: Demoll N) 21.8 g , 2500 g of a styrene monomer and 43.3 g of butylbenzyltrithiocarbonate were charged, the internal temperature was raised to 80° C., and the mixture was stirred at 200 rpm under a nitrogen stream. As a polymerization initiator, 27.3 g of 2,2'-azobis[2-(2-imidazolin-2-yl)propane]dihydrogen chloride (trade name: VA-044, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added to polymerize. started. 20 ml of the obtained latex was sampled for physical property measurement, and the remaining latex was used in polymerization step 2. The number average molecular weight, molecular weight distribution, and glass transition temperature of the polymer block (A-7) were determined by analysis in the same manner as in Example 1. The analysis results are shown in Table 1.

(Polymerization step 2) Synthesis of butadiene-based polymer block (B-7) Polymerization was carried out using an autoclave with a capacity of 10 L and equipped with a stirrer and a jacket for heating and cooling. 2732 g of pure water, 131 g of disproportionated potassium rosinate (manufactured by Harima Kasei Co., Ltd.), 21.3 g of potassium hydroxide, sodium salt of β-naphthalenesulfonic acid formalin condensate (manufactured by Kao Corporation, trade name: Demoll N) 10.9 g 783 g of the latex containing the polymer block (A-7) prepared in the polymerization step 1 was charged, the internal temperature was raised to 45° C., the internal pressure of the reactor was increased to 0.6 MPaG using nitrogen, and the mixture was stirred at 200 rpm. After that, 3000 g of butadiene monomer was slowly added over 2 hours to carry out polymerization. When the polymerization rate of the butadiene monomer reaches 80%, the polymerization is stopped by adding a 10% by weight aqueous solution of N,N-diethylhydroxylamine as a polymerization terminator, and the unreacted butadiene monomer is removed by distillation under reduced pressure. removed the body. For physical property measurement, 20 ml of the obtained latex was sampled, and the remaining latex was used to prepare a film for evaluation. The average particle size of the latex, the mechanical stability of the latex, and the content (% by mass) of the polymer block (A-7) of the diene-based block copolymer and the diene-based polymer block (B-7) were measured in Example 1. It was obtained by the same analysis as The analysis results are shown in Table 1. Also, the toluene-insoluble matter was obtained from the sampled latex. The analysis results are shown in Table 1.

(Example 8)
(Polymerization Step 1) Synthesis of Polymer Block (A-8) Polymerization was carried out using an autoclave with a capacity of 10 L, equipped with a stirrer and a jacket for heating and cooling. 4666 g of pure water, 224 g of disproportionated potassium rosinate (manufactured by Harima Kasei Co., Ltd.), 36.4 g of potassium hydroxide, sodium salt of β-naphthalenesulfonic acid formalin condensate (manufactured by Kao Corporation, trade name: Demoll N) 18.7 g , 350 g of a styrene monomer and 6.07 g of butylbenzyl trithiocarbonate were charged, the internal temperature was raised to 80° C., and the mixture was stirred at 200 rpm under a nitrogen stream. 3.82 g of 2,2′-azobis[2-(2-imidazolin-2-yl)propane]dihydrogen chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name: VA-044) is added as a polymerization initiator to polymerize. started. 20 ml of the obtained latex was sampled for physical property measurement, and the remaining latex was used in polymerization step 2. The number average molecular weight, molecular weight distribution, and glass transition temperature of the polymer block (A-8) were determined by analysis in the same manner as in Example 1. Table 1 shows the analysis results.

(Polymerization step 2) Synthesis of butadiene-based polymer block (B-8) After the polymerization step 1, when the internal temperature decreased to 45°C, the nitrogen flow was stopped, and nitrogen was used to reduce the internal pressure of the reactor to 0.6 MPaG. was boosted to 4480 g of butadiene monomer and 91.4 g of triallyl isocyanurate were slowly added over 2 hours to carry out polymerization. When the polymerization rate of the butadiene monomer reaches 80%, the polymerization is stopped by adding a 10% by weight aqueous solution of N,N-diethylhydroxylamine as a polymerization terminator, and the unreacted butadiene monomer is removed by distillation under reduced pressure. removed the body. For physical property measurement, 20 ml of the obtained latex was sampled, and the remaining latex was used to prepare a film for evaluation. The average particle size of the latex, the mechanical stability of the latex, and the content (% by mass) of the polymer block (A-8) of the diene-based block copolymer and the diene-based polymer block (B-8) were measured in Example 1. It was obtained by the same analysis as Also, the toluene-insoluble matter was determined from the sampled latex. Table 1 shows the analysis results.

(Example 9)
(Polymerization Step 1) Synthesis of Polymer Block (A-9) Polymerization was carried out using an autoclave with a capacity of 10 L, equipped with a stirrer and a jacket for heating and cooling. 4666 g of pure water, 224 g of disproportionated potassium rosinate (manufactured by Harima Kasei Co., Ltd.), 36.4 g of potassium hydroxide, sodium salt of β-naphthalenesulfonic acid formalin condensate (manufactured by Kao Corporation, trade name: Demoll N) 18.7 g , 350 g of a styrene monomer and 6.07 g of butylbenzyl trithiocarbonate were charged, the internal temperature was raised to 80° C., and the mixture was stirred at 200 rpm under a nitrogen stream. 3.82 g of 2,2′-azobis[2-(2-imidazolin-2-yl)propane]dihydrogen chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name: VA-044) is added as a polymerization initiator to polymerize. started. 20 ml of the obtained latex was sampled for physical property measurement, and the remaining latex was used in polymerization step 2. The number average molecular weight, molecular weight distribution and glass transition temperature of the polymer block (A-9) were determined by analysis in the same manner as in Example 1. Table 1 shows the analysis results.

(Polymerization step 2) Synthesis of butadiene-based polymer block (B-9) After the polymerization step 1, when the internal temperature has decreased to 45°C, the nitrogen flow is stopped, and nitrogen is used to reduce the internal pressure of the reaction vessel to 0.6 MPaG. was boosted to 4480 g of butadiene monomer and 91.4 g of neopentylglycol hydroxypivalate acrylic acid adduct (manufactured by Kyoeisha Chemical Co., Ltd.) were slowly added over 2 hours to carry out polymerization. When the polymerization rate of the butadiene monomer reaches 80%, the polymerization is stopped by adding a 10% by weight aqueous solution of N,N-diethylhydroxylamine as a polymerization terminator, and the unreacted butadiene monomer is removed by distillation under reduced pressure. removed the body. For physical property measurement, 20 ml of the obtained latex was sampled, and the remaining latex was used to prepare a film for evaluation. The average particle size of the latex, the mechanical stability of the latex, and the content (% by mass) of the polymer block (A-9) of the diene-based block copolymer and the diene-based polymer block (B-9) were measured in Example 1. It was obtained by the same analysis as Also, the toluene-insoluble matter was determined from the sampled latex. Table 1 shows the analysis results.

(Example 10)
(Polymerization Step 1) Synthesis of Polymer Block (A-10) Polymerization was carried out using an autoclave with a capacity of 10 L, equipped with a stirrer and a jacket for heating and cooling. 4666 g of pure water, 224 g of disproportionated potassium rosinate (manufactured by Harima Kasei Co., Ltd.), 36.4 g of potassium hydroxide, sodium salt of β-naphthalenesulfonic acid formalin condensate (manufactured by Kao Corporation, trade name: Demoll N) 18.7 g , 350 g of a styrene monomer and 6.07 g of butylbenzyl trithiocarbonate were charged, the internal temperature was raised to 80° C., and the mixture was stirred at 200 rpm under a nitrogen stream. 3.82 g of 2,2′-azobis[2-(2-imidazolin-2-yl)propane]dihydrogen chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name: VA-044) is added as a polymerization initiator to polymerize. started. 20 ml of the obtained latex was sampled for physical property measurement, and the remaining latex was used in polymerization step 2. The number average molecular weight, molecular weight distribution, and glass transition temperature of the polymer block (A-10) were determined by analysis in the same manner as in Example 1. Table 1 shows the analysis results.

(Polymerization step 2) Synthesis of butadiene-based polymer block (B-10) After the polymerization step 1, the nitrogen flow was stopped when the internal temperature dropped to 45°C, and nitrogen was used to reduce the internal pressure of the reactor to 0.6 MPaG. was boosted to 4480 g of butadiene monomer and 91.4 g of trimethylolpropane triacrylate (manufactured by Kyoeisha Chemical Co., Ltd.) were slowly added over 2 hours to carry out polymerization. When the polymerization rate of the butadiene monomer reaches 80%, the polymerization is stopped by adding a 10% by weight aqueous solution of N,N-diethylhydroxylamine as a polymerization terminator, and the unreacted butadiene monomer is removed by distillation under reduced pressure. removed the body. For physical property measurement, 20 ml of the obtained latex was sampled, and the remaining latex was used to prepare a film for evaluation. The average particle size of the latex, the mechanical stability of the latex, and the content (% by mass) of the polymer block (A-10) of the diene block copolymer and the diene polymer block (B-10) were measured in Example 1. It was obtained by the same analysis as Table 1 shows the analysis results.

(Example 11)
(Polymerization Step 1) Synthesis of Polymer Block (A-11) Polymerization was carried out using an autoclave with a capacity of 10 L, equipped with a stirrer and a jacket for heating and cooling. 6667 g of pure water, 320 g of disproportionated potassium rosinate (manufactured by Harima Kasei Co., Ltd.), 52.0 g of potassium hydroxide, sodium salt of β-naphthalenesulfonic acid formalin condensate (manufactured by Kao Corporation, trade name: Demoll N) 26.7 g , 500 g of a styrene monomer, and 6.50 g of butylbenzyl trithiocarbonate were charged, the internal temperature was raised to 80° C., and the mixture was stirred at 200 rpm under a nitrogen stream. 4.09 g of 2,2′-azobis[2-(2-imidazolin-2-yl)propane]dihydrogen chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name: VA-044) is added as a polymerization initiator to polymerize. started. 20 ml of the obtained latex was sampled for physical property measurement, and the remaining latex was used in polymerization step 2. The number average molecular weight, molecular weight distribution, and glass transition temperature of the polymer block (A-11) were determined by analysis in the same manner as in Example 1. Table 1 shows the analysis results.

(Polymerization step 2) Synthesis of butadiene-based polymer block (B-11) After the polymerization step 1, the nitrogen flow was stopped when the internal temperature dropped to 45°C, and nitrogen was used to reduce the internal pressure of the reactor to 0.6 MPaG. was boosted to 1607 g of butadiene monomer and 32.8 g of 1.9-nonanediol dimethacrylate were slowly added over 2 hours to effect polymerization. When the polymerization rate of the butadiene monomer reaches 80%, the polymerization is stopped by adding a 10% by weight aqueous solution of N,N-diethylhydroxylamine as a polymerization terminator, and the unreacted butadiene monomer is removed by distillation under reduced pressure. removed the body. For physical property measurement, 20 ml of the obtained latex was sampled, and the remaining latex was used to prepare a film for evaluation. The average particle size of the latex, the mechanical stability of the latex, and the content (% by mass) of the diene-based block copolymer polymer block (A-11) and the butadiene-based polymer block (B-11) were measured in Example 1. It was obtained by the same analysis as Also, the toluene-insoluble matter was determined from the sampled latex. Table 1 shows the analysis results.

(Example 12)
(Polymerization Step 1) Synthesis of Polymer Block (A-12) Polymerization was carried out using an autoclave with a capacity of 10 L, equipped with a stirrer and a jacket for heating and cooling. 5450 g of pure water, 262 g of disproportionated potassium rosinate (manufactured by Harima Kasei Co., Ltd.), 42.5 g of potassium hydroxide, sodium salt of β-naphthalenesulfonic acid formalin condensate (manufactured by Kao Corporation, trade name: Demoll N) 21.8 g , 2500 g of a styrene monomer and 32.5 g of butylbenzyl trithiocarbonate were charged, the internal temperature was raised to 80° C., and the mixture was stirred at 200 rpm under a nitrogen stream. 20.5 g of 2,2′-azobis[2-(2-imidazolin-2-yl)propane]dihydrogen chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name: VA-044) is added as a polymerization initiator to polymerize. started. 20 ml of the obtained latex was sampled for physical property measurement, and the remaining latex was used in polymerization step 2. The number average molecular weight, molecular weight distribution and glass transition temperature of the polymer block (A-12) were determined by analysis in the same manner as in Example 1. The analysis results are shown in Table 1.

(Polymerization step 2) Synthesis of butadiene-based polymer block (B-12) Polymerization was carried out using an autoclave with a capacity of 10 L and equipped with a stirrer and a jacket for heating and cooling. 1188 g of pure water, 57 g of disproportionated potassium rosinate (manufactured by Harima Kasei Co., Ltd.), 9.3 g of potassium hydroxide, sodium salt of β-naphthalenesulfonic acid formalin condensate (manufactured by Kao Corporation, trade name: Demol N) 4.8 g 3147 g of the latex containing the polymer block (A-12) prepared in the polymerization step 1 was charged, the internal temperature was raised to 45° C., the internal pressure of the reactor was increased to 0.6 MPaG using nitrogen, and the mixture was stirred at 200 rpm. After that, 3000 g of butadiene monomer was slowly added over 2 hours to carry out polymerization. When the polymerization rate of the butadiene monomer reaches 80%, the polymerization is stopped by adding a 10% by weight aqueous solution of N,N-diethylhydroxylamine as a polymerization terminator, and the unreacted butadiene monomer is removed by distillation under reduced pressure. removed the body. For physical property measurement, 20 ml of the obtained latex was sampled, and the remaining latex was used to prepare a film for evaluation. The average particle size of the latex, the mechanical stability of the latex, and the content (% by mass) of the diene-based block copolymer polymer block (A-12) and the butadiene-based polymer block (B-12) were measured in Example 1. It was obtained by the same analysis as The analysis results are shown in Table 1. Also, the toluene-insoluble matter was obtained from the sampled latex. The analysis results are shown in Table 1.

(Example 13)
(Polymerization Step 1) Synthesis of Polymer Block (A-13) Polymerization was carried out using an autoclave with a capacity of 10 L and equipped with a stirrer and a jacket for heating and cooling. 4666 g of pure water, 224 g of disproportionated potassium rosinate (manufactured by Harima Kasei Co., Ltd.), 36.4 g of potassium hydroxide, sodium salt of β-naphthalenesulfonic acid formalin condensate (manufactured by Kao Corporation, trade name: Demoll N) 18.7 g , 350 g of methyl methacrylate monomer, and 4.14 g of butyl-2-cyanoisopropyltrithiocarbonate were charged, the internal temperature was raised to 80° C., and the mixture was stirred at 200 rpm under a nitrogen stream. 2.87 g of 2,2′-azobis[2-(2-imidazolin-2-yl)propane]dihydrogen chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name: VA-044) is added as a polymerization initiator to polymerize. started. 20 ml of the obtained latex was sampled for physical property measurement, and the remaining latex was used in polymerization step 2. The number average molecular weight, molecular weight distribution, and glass transition temperature of the polymer block (A-13) were determined by analysis in the same manner as in Example 1. The analysis results are shown in Table 1.

(Polymerization step 2) Synthesis of butadiene-based polymer block (B-13) After the polymerization step 1, when the internal temperature has decreased to 45°C, the nitrogen flow is stopped, and nitrogen is used to reduce the internal pressure of the reaction vessel to 0.6 MPaG. was boosted to Polymerization was carried out by slowly adding 4424 g of butadiene monomer and 90.3 g of 1,9-nonanediol dimethacrylate over 2 hours. When the polymerization rate of the butadiene monomer reaches 80%, the polymerization is stopped by adding a 10% by weight aqueous solution of N,N-diethylhydroxylamine as a polymerization terminator, and the unreacted butadiene monomer is removed by distillation under reduced pressure. removed the body. For physical property measurement, 20 ml of the obtained latex was sampled, and the remaining latex was used to prepare a film for evaluation. The average particle size of the latex, the mechanical stability of the latex, and the content (% by mass) of the diene-based block copolymer polymer block (A-13) and the butadiene-based polymer block (B-13) were measured in Example 1. It was obtained by the same analysis as Also, the toluene-insoluble matter was obtained from the sampled latex. The analysis results are shown in Table 1.

(Comparative example 1)
(Polymerization Step 1) Synthesis of Polymer Block (A-14) Polymerization was carried out using an autoclave with a capacity of 10 L and equipped with a stirrer and a jacket for heating and cooling. 3067 g of pure water, 147 g of disproportionated potassium rosinate (manufactured by Harima Kasei Co., Ltd.), 23.9 g of potassium hydroxide, sodium salt of β-naphthalenesulfonic acid formalin condensate (manufactured by Kao Corporation, trade name: Demoll N) 12.3 g , 230 g of a styrene monomer and 3.99 g of butylbenzyl trithiocarbonate were charged, the internal temperature was raised to 80° C., and the mixture was stirred at 200 rpm under a nitrogen stream. 2.51 g of 2,2′-azobis[2-(2-imidazolin-2-yl)propane]dihydrogen chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name: VA-044) is added as a polymerization initiator to polymerize. started. 20 ml of the obtained latex was sampled for physical property measurement, and the remaining latex was used in polymerization step 2. The number average molecular weight, molecular weight distribution and glass transition temperature of the polymer block (A-14) were determined by analysis in the same manner as in Example 1. Table 1 shows the analysis results.

(Polymerization step 2) Synthesis of butadiene-based polymer block (B-14) After the polymerization step 1, the nitrogen flow was stopped when the internal temperature dropped to 45°C, and nitrogen was used to reduce the internal pressure of the reactor to 0.6 MPaG. was boosted to Polymerization was carried out by slowly adding 7278 g of butadiene monomer and 148.5 g of 1,9-nonanediol dimethacrylate over 2 hours. When the polymerization rate of the butadiene monomer reaches 80%, the polymerization is stopped by adding a 10% by weight aqueous solution of N,N-diethylhydroxylamine as a polymerization terminator, and the unreacted butadiene monomer is removed by distillation under reduced pressure. removed the body. For physical property measurement, 20 ml of the obtained latex was sampled, and the remaining latex was used to prepare a film for evaluation. The average particle size of the latex, the mechanical stability of the latex, and the content (% by mass) of the diene-based block copolymer polymer block (A-14) and the butadiene-based polymer block (B-14) were measured in Example 1. It was obtained by the same analysis as Also, the toluene-insoluble matter was obtained from the sampled latex. The analysis results are shown in Table 1.

(Comparative example 2)
(Polymerization Step 1) Synthesis of Polymer Block (A-15) Polymerization was carried out using an autoclave with a capacity of 10 L, equipped with a stirrer and a jacket for heating and cooling. 6667 g of pure water, 320 g of disproportionated potassium rosinate (manufactured by Harima Kasei Co., Ltd.), 52.0 g of potassium hydroxide, sodium salt of β-naphthalenesulfonic acid formalin condensate (manufactured by Kao Corporation, trade name: Demoll N) 26.7 g , 500 g of a styrene monomer and 4.27 g of butylbenzyl trithiocarbonate were charged, the internal temperature was raised to 80° C., and the mixture was stirred at 200 rpm under a nitrogen stream. 2.69 g of 2,2′-azobis[2-(2-imidazolin-2-yl)propane]dihydrogen chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name: VA-044) is added as a polymerization initiator to polymerize. started. 20 ml of the obtained latex was sampled for physical property measurement, and the remaining latex was used in polymerization step 2. The number average molecular weight, molecular weight distribution, and glass transition temperature of the polymer block (A-15) were determined by analysis in the same manner as in Example 1. Table 1 shows the analysis results.

(Polymerization step 2) Synthesis of butadiene-based polymer block (B-15) After the polymerization step 1, the nitrogen flow was stopped when the internal temperature dropped to 45°C, and nitrogen was used to reduce the internal pressure of the reactor to 0.6 MPaG. was boosted to 1607 g of butadiene monomer and 32.8 g of 1.9-nonanediol dimethacrylate were slowly added over 2 hours to effect polymerization. When the polymerization rate of the butadiene monomer reaches 80%, the polymerization is stopped by adding a 10% by weight aqueous solution of N,N-diethylhydroxylamine as a polymerization terminator, and the unreacted butadiene monomer is removed by distillation under reduced pressure. removed the body. For physical property measurement, 20 ml of the obtained latex was sampled, and the remaining latex was used to prepare a film for evaluation. The average particle size of the latex, the mechanical stability of the latex, and the content (% by mass) of the diene-based block copolymer polymer block (A-15) and the butadiene-based polymer block (B-15) were measured in Example 1. It was obtained by the same analysis as Also, the toluene-insoluble matter was obtained from the sampled latex. The analysis results are shown in Table 1.

(Comparative Example 3)
Synthesis of Copolymer Containing Only Butadiene-based Polymer Block (B-16) Polymerization was carried out using an autoclave with a capacity of 10 L, equipped with a stirrer and a jacket for heating and cooling. 3600 g of pure water, 175 g of disproportionated potassium rosinate (manufactured by Harima Kasei Co., Ltd.), 28.4 g of potassium hydroxide, sodium salt of β-naphthalenesulfonic acid formalin condensate (manufactured by Kao Corporation, trade name: Demoll N) 16.0 g , 4000 g of butadiene monomer, 81.6 g of 1.9-nonanediol dimethacrylate, and 4.72 g of butylbenzyltrithiocarbonate were charged, the internal temperature was raised to 45° C., and the internal pressure of the reactor was adjusted to 0.6 MPaG using nitrogen. Stir at 200 rpm under increased pressure. As a polymerization initiator, 2.96 g of 2,2'-azobis[2-(2-imidazolin-2-yl)propane]dihydrogen chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name: VA-044) was added to polymerize. started. When the polymerization rate of the butadiene monomer reaches 80%, the polymerization is stopped by adding a 10% by weight aqueous solution of N,N-diethylhydroxylamine as a polymerization terminator, and the unreacted butadiene monomer is removed by distillation under reduced pressure. removed the body. For physical property measurement, 20 ml of the obtained latex was sampled, and the remaining latex was used to prepare a film for evaluation. The average particle size of the latex and the mechanical stability of the latex were determined by analysis in the same manner as in Example 1. Also, the toluene-insoluble matter was determined from the sampled latex. Table 1 shows the analysis results.

(Comparative Example 4)
(Polymerization Step 1) Synthesis of Polymer Block (A-17) Polymerization was carried out using an autoclave with a capacity of 10 L, equipped with a stirrer and a jacket for heating and cooling. 4616 g of pure water, 206 g of disproportionated potassium rosinate (manufactured by Harima Kasei Co., Ltd.), 2.3 g of potassium hydroxide, sodium salt of β-naphthalenesulfonic acid formalin condensate (manufactured by Kao Corporation, trade name: Demoll N) 46.2 g , 462 g of a styrene monomer and 9.2 g of butylbenzyl trithiocarbonate were charged, the internal temperature was raised to 80° C., and the mixture was stirred at 200 rpm under a nitrogen stream. 6.0 g of 2,2′-azobis[2-(2-imidazolin-2-yl)propane]dihydrogen chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name: VA-044) is added as a polymerization initiator to polymerize. started. 20 ml of the obtained latex was sampled for physical property measurement, and the remaining latex was used in polymerization step 2. The number average molecular weight, molecular weight distribution, and glass transition temperature of the polymer block (A-16) were determined by analysis in the same manner as in Example 1. The analysis results are shown in Table 1.

(Polymerization step 2) Synthesis of butadiene-based polymer block (B-17) After the polymerization step 1, the nitrogen flow was stopped when the internal temperature dropped to 45°C, and nitrogen was used to reduce the internal pressure of the reactor to 0.6 MPaG. was boosted to Polymerization was carried out by slowly adding 4154 g of butadiene monomer over 2 hours. When the polymerization rate of the butadiene monomer reaches 80%, the polymerization is stopped by adding a 10% by weight aqueous solution of N,N-diethylhydroxylamine as a polymerization terminator, and the unreacted butadiene monomer is removed by distillation under reduced pressure. removed the body. For physical property measurement, 20 ml of the obtained latex was sampled, and the remaining latex was used to prepare a film for evaluation. The average particle size of the latex, the mechanical stability of the latex, and the content (% by mass) of the polymer block (A-17) of the diene block copolymer and the butadiene polymer block (B-17) were measured in Example 1. It was obtained by the same analysis as The analysis results are shown in Table 1. Also, the toluene-insoluble matter was determined from the sampled latex. The analysis results are shown in Table 1.

(Comparative Example 5)
(Polymerization Step 1) Synthesis of Polymer Block (A-18) Polymerization was carried out using an autoclave with a capacity of 10 L, equipped with a stirrer and a jacket for heating and cooling. 4616 g of pure water, 206 g of disproportionated potassium rosinate (manufactured by Harima Kasei Co., Ltd.), 2.3 g of potassium hydroxide, sodium salt of β-naphthalenesulfonic acid formalin condensate (manufactured by Kao Corporation, trade name: Demoll N) 46.2 g , 692 g of a styrene monomer and 9.2 g of butylbenzyl trithiocarbonate were charged, the internal temperature was raised to 80° C., and the mixture was stirred at 200 rpm under a nitrogen stream. 6.0 g of 2,2′-azobis[2-(2-imidazolin-2-yl)propane]dihydrogen chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name: VA-044) is added as a polymerization initiator to polymerize. started. 20 ml of the obtained latex was sampled for physical property measurement, and the remaining latex was used in polymerization step 2. The number average molecular weight, molecular weight distribution and glass transition temperature of the polymer block (A-18) were determined by analysis in the same manner as in Example 1. The analysis results are shown in Table 1.

(Polymerization step 2) Synthesis of butadiene-based polymer block (B-18) After the polymerization step 1, the nitrogen flow was stopped when the internal temperature dropped to 45°C, and the internal pressure of the reactor was reduced to 0.6 MPaG using nitrogen. was boosted to Polymerization was carried out by slowly adding 3924 g of butadiene monomer over 2 hours. When the polymerization rate of the butadiene monomer reaches 80%, the polymerization is stopped by adding a 10% by weight aqueous solution of N,N-diethylhydroxylamine as a polymerization terminator, and the unreacted butadiene monomer is removed by distillation under reduced pressure. removed the body. For physical property measurement, 20 ml of the obtained latex was sampled, and the remaining latex was used to prepare a film for evaluation. The average particle size of the latex, the mechanical stability of the latex, and the content (% by mass) of the diene-based block copolymer polymer block (A-18) and the butadiene-based polymer block (B-18) were measured in Example 1. It was obtained by the same analysis as Table 1 shows the analysis results. Also, the toluene-insoluble matter was obtained from the sampled latex. Table 1 shows the analysis results.

(Comparative Example 6)
Synthesis of triblock copolymer (synthesis of first block)
Polymerization was carried out using an autoclave with a capacity of 10 L, a stirrer and a jacket for heating and cooling. 4613 g of pure water, 204.4 g of disproportionated potassium rosinate (manufactured by Harima Kasei Co., Ltd.), 2.3 g of potassium hydroxide, sodium salt of β-naphthalenesulfonic acid formalin condensate (manufactured by Kao Corporation, trade name: Demoll N) 46 1 g of styrene monomer, 230 g of styrene monomer, and 9.2 g of benzyl 1-pyrrolecarbodithioate were added, the internal temperature was raised to 80° C., and the mixture was stirred at 200 rpm under a nitrogen stream. 6.0 g of 2,2′-azobis[2-(2-imidazolin-2-yl)propane]dihydrogen chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name: VA-044) is added as a polymerization initiator to polymerize. started. 20 ml of the obtained latex was sampled for physical property measurement, and the remaining latex was used in the next polymerization step. The number average molecular weight, molecular weight distribution, and glass transition temperature of the first block were obtained by analysis in the same manner as in Example 1. The analysis results are shown in Table 2.
(Synthesis of second block)
After the synthesis of the first block, when the internal temperature dropped to 45° C., the nitrogen gas flow was stopped and nitrogen was used to increase the internal pressure of the reactor to 0.6 MPaG. Polymerization was carried out by adding 4424 g of butadiene monomer. When the polymerization rate of the butadiene monomer reaches 80%, the polymerization is stopped by adding a 10% by weight aqueous solution of N,N-diethylhydroxylamine as a polymerization terminator, and the unreacted butadiene monomer is removed by distillation under reduced pressure. removed the body. The resulting latex was used in the next polymerization step.
(Synthesis of the third block)
After synthesis of the second block, the internal temperature was raised to 80° C., 230 g of styrene monomer was charged, and 2,2′-azobis[2-(2-imidazolin-2-yl)propane] was used as a polymerization initiator. Polymerization was initiated by adding 6.0 g of hydrogen dichloride (trade name: VA-044, manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.). After the polymerization, the mixture was cooled to 25°C to terminate the polymerization. For physical property measurement, 20 ml of the obtained latex was sampled, and the remaining latex was used to prepare a film for evaluation. The average particle size of the latex, the mechanical stability of the latex, the content (% by mass) of the styrene block that is the first block and the third block of the synthesized triblock copolymer, and the butadiene block that is the second block, toluene The insoluble matter was determined by analysis in the same manner as in Example 1. The analysis results are shown in Table 2.

(Comparative Example 7)
Preparation of mixture of homopolymer of polymer block (A) and homopolymer of butadiene-based polymer block (B) (synthesis of homopolymer of polymer block (A))
Polymerization was carried out using an autoclave with a capacity of 10 L, a stirrer and a jacket for heating and cooling. 4666 g of pure water, 224 g of disproportionated potassium rosinate (manufactured by Harima Kasei Co., Ltd.), 36.4 g of potassium hydroxide, sodium salt of β-naphthalenesulfonic acid formalin condensate (manufactured by Kao Corporation, trade name: Demoll N) 18.7 g , 350 g of a styrene monomer and 6.07 g of butylbenzyl trithiocarbonate were charged, the internal temperature was raised to 80° C., and the mixture was stirred at 200 rpm under a nitrogen stream. 3.82 g of 2,2′-azobis[2-(2-imidazolin-2-yl)propane]dihydrogen chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name: VA-044) was added as a polymerization initiator. Polymerization started. When the polymerization rate of the styrene monomer reached 95%, the polymerization was stopped by adding a 10% by weight aqueous solution of N,N-diethylhydroxylamine as a polymerization terminator. 20 ml of the obtained latex was sampled for physical property measurement. The number average molecular weight, molecular weight distribution, and glass transition temperature of the homopolymer of polymer block (A) were determined by analysis in the same manner as in Example 1. The analysis results are shown in Table 3.

(Synthesis of homopolymer of butadiene-based polymer block (B))
Polymerization was carried out using an autoclave with a capacity of 10 L, a stirrer and a jacket for heating and cooling. 3960 g of pure water, 193 g of disproportionated potassium rosinate (manufactured by Harima Kasei Co., Ltd.), 31.2 g of potassium hydroxide, sodium salt of β-naphthalenesulfonic acid formalin condensate (manufactured by Kao Corporation, trade name: Demoll N) 17.6 g , 4400 g of butadiene monomer, 89.8 g of 1.9-nonanediol dimethacrylate, and 5.19 g of butylbenzyltrithiocarbonate were charged, the internal temperature was raised to 45° C., and the internal pressure of the reaction vessel was adjusted to 0.6 MPaG using nitrogen. Stir at 200 rpm under increased pressure. 3.26 g of 2,2′-azobis[2-(2-imidazolin-2-yl)propane]dihydrogen chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name: VA-044) is added as a polymerization initiator to polymerize. started. When the polymerization rate of the butadiene monomer reaches 80%, the polymerization is stopped by adding a 10% by weight aqueous solution of N,N-diethylhydroxylamine as a polymerization terminator, and the unreacted butadiene monomer is removed by distillation under reduced pressure. removed the body.

(Mixing of homopolymer latex of polymer block (A) and homopolymer latex of butadiene-based polymer block (B))
4000 g of the resulting homopolymer latex of the polymer block (A) and 4000 g of the latex of the homopolymer of the butadiene polymer block (B) were charged into an autoclave having a capacity of 10 L and equipped with a stirrer and a heating/cooling jacket. °C and stirred at 200 rpm. For physical property measurement, 20 ml of the obtained latex was sampled, and the remaining latex was used to prepare a film for evaluation. The average particle size of the latex, the mechanical stability of the latex, and the content (% by mass) of the homopolymer of the polymer block (A) and the homopolymer of the butadiene-based polymer block (B) in the polymer obtained by mixing ), and the toluene-insoluble matter was determined by analysis in the same manner as in Example 1. The analysis results are shown in Table 3.

(Comparative Example 8)
Synthesis of Diene Block Copolymer Latex by Forced Emulsification (Polymerization Step 1) Synthesis of Polymer Block (A-19) Polymerization was carried out using an autoclave with a capacity of 10 L and equipped with a stirrer and a heating and cooling jacket. 4616 g of tetrahydrofuran, 87.5 g of styrene monomer and 1.5 g of benzylbutyltrithiocarbonate were charged, the internal temperature was raised to 80° C., and the mixture was stirred at 200 rpm under a nitrogen stream. Polymerization was initiated by adding 0.49 g of azobisisobutyronitrile (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd., trade name: AIBN) as a polymerization initiator. 20 ml of the resulting solution was sampled for physical property measurement, and the remaining latex was used in the next polymerization step. The number average molecular weight, molecular weight distribution, and glass transition temperature of the polymer block (A-19) were determined by analysis in the same manner as in Example 1. The analysis results are shown in Table 4.

(Polymerization step 2) Synthesis of butadiene-based polymer block (B-19) After the polymerization step 1, when the internal temperature decreased to 45°C, the nitrogen flow was stopped, and nitrogen was used to reduce the internal pressure of the reactor to 0.6 MPaG. was boosted to 1120 g of butadiene monomer and 22.8 g of 1.9-nonanediol dimethacrylate were slowly added over 2 hours to effect polymerization. When the polymerization rate of the butadiene monomer reaches 80%, the polymerization is stopped by adding a 10% by mass tetrahydrofuran solution of phenothiazine as a polymerization terminator, and the unreacted butadiene monomer and tetrahydrofuran are removed by distillation under reduced pressure. A sample of the diene block copolymer was obtained.

(Forced Emulsification Step) Forced Emulsification of Diene Block Copolymer 350 g of the diene block copolymer obtained in the polymerization step 2 was dissolved in 4200 g of benzene. For the resulting solution, 4725 g of pure water, 70 g of disproportionated potassium rosinate (manufactured by Harima Kasei Co., Ltd.), 0.78 g of potassium hydroxide, sodium salt of β-naphthalenesulfonic acid formalin condensate (manufactured by Kao Corporation, trade name) : Demoll N) 1.4 g was added and emulsified forcibly using a homogenizer. Benzene and water were removed by distillation under reduced pressure so that the resulting latex had a solid concentration of 50%, thereby obtaining a diene block copolymer latex. For physical property measurement, 20 ml of the obtained latex was sampled, and the remaining latex was used to prepare a film for evaluation. Average particle size of latex, mechanical stability of latex, content (% by mass) of polymer block (A-19) of diene block copolymer and butadiene polymer block (B-19), toluene insoluble matter was determined by analysis in the same manner as in Example 1. The analysis results are shown in Table 4.

(Comparative Example 9)
Synthesis of triblock copolymer latex by forced emulsification (synthesis of first block)
Polymerization was carried out using an autoclave with a capacity of 10 L, a stirrer and a jacket for heating and cooling. 4616 g of tetrahydrofuran, 70 g of styrene monomer and 2.8 g of benzyl 1-pyrrole carbodithioate were charged, the internal temperature was raised to 80° C., and the mixture was stirred at 200 rpm under a nitrogen stream. Polymerization was initiated by adding 0.93 g of azobisisobutyronitrile (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd., trade name: AIBN) as a polymerization initiator. 20 ml of the resulting solution was sampled for physical property measurement, and the remaining latex was used in the next polymerization step. The number average molecular weight, molecular weight distribution, and glass transition temperature of the first block were obtained by analysis in the same manner as in Example 1. The analysis results are shown in Table 5.
(Synthesis of second block)
After the polymerization step 1, when the internal temperature was lowered to 45°C, the nitrogen flow was stopped, and the internal pressure of the reactor was increased to 0.6 MPaG using nitrogen. Polymerization was carried out by adding 1346 g of butadiene monomer. When the polymerization rate of the butadiene monomer reached 80%, the polymerization was stopped by adding a 10 mass % tetrahydrofuran solution of phenothiazine as a polymerization terminator.
(Synthesis of the third block)
After synthesis of the second block, the internal temperature was raised to 80°C, 70 g of styrene monomer was charged, and azobisisobutyronitrile (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name: AIBN) was used as a polymerization initiator. Polymerization was initiated by adding 0.93 g. After polymerization, unreacted butadiene monomer and tetrahydrofuran were removed by distillation under reduced pressure to obtain a triblock copolymer.
(Forced Emulsification Step) Forced Emulsification of Triblock Copolymer 350 g of the triblock copolymer obtained in the synthesis of the third block was dissolved in 4200 g of benzene. For the resulting solution, 4725 g of pure water, 70 g of disproportionated potassium rosinate (manufactured by Harima Kasei Co., Ltd.), 0.78 g of potassium hydroxide, sodium salt of β-naphthalenesulfonic acid formalin condensate (manufactured by Kao Corporation, trade name) : Demoll N) 1.4 g was added and emulsified forcibly using a homogenizer. Benzene and water were removed by distillation under reduced pressure so that the resulting latex had a solid concentration of 50%, thereby obtaining a diene block copolymer latex. For physical property measurement, 20 ml of the obtained latex was sampled, and the remaining latex was used to prepare a film for evaluation. The average particle size of the latex, the mechanical stability of the latex, the content (% by mass) of the styrene block that is the first block and the third block of the synthesized triblock copolymer, and the butadiene block that is the second block, toluene The insoluble matter was determined by analysis in the same manner as in Example 1. The analysis results are shown in Table 5.

[analysis]
(Measurement of number average molecular weight and molecular weight distribution of polymer block (A))
The number average molecular weight and molecular weight distribution are polystyrene-equivalent values measured by gel permeation chromatography (GPC) under the measurement conditions described below.
Device name: HLC-8320 (manufactured by Tosoh Corporation)
Column: 3 TSKgel GMHHR-H in series Temperature: 40°C
Detection: Differential refractive index Solvent: Tetrahydrofuran Calibration curve: Prepared using standard polystyrene (PS).

(Glass transition temperature of polymer block (A))
The glass transition temperature was measured according to JIS K 7121 using a differential scanning calorimeter by the following method.
Apparatus name: DSC1 (manufactured by Mettler Toledo)
Procedure: Under a nitrogen stream of 50 ml/min, heat up to 120°C at a temperature increase rate of 10°C/min, keep at 120°C for 10 minutes, cool to -60°C, and heat at a temperature increase rate of 10°C/min. From the DSC curve obtained by heating up to 120 ° C at , a straight line extending the pace line on the high temperature side to the low temperature side and a tangent line drawn at a point that maximizes the gradient on the high temperature side of the peak The temperature at the intersection point was taken as the glass transition temperature.

(Measurement of content of polymer block (A) and butadiene polymer block (B) of diene block copolymer)
Using pyrolysis gas chromatogram and 1H-NMR, it was measured by the following method.
Pyrolysis gas chromatogram Apparatus name: HP5890-II
Column: DB-5 0.25 mmφ×30 m (thickness 1.0 μm)
Column temperature: 50°C (5 min) → 10°C/min → 150°C → 25°C/min → 300°C
Inlet temperature: 250°C
Detector temperature: 280°C
Detector: FID
1H-NMR Device name: JNM-ECX-400 (manufactured by JEOL Ltd.)
Procedure: A diene-based block copolymer consisting of a polymer block (A) and a butadiene-based polymer block (B) containing no polyfunctional monomer units is measured by a pyrolysis gas chromatogram, and the polymer block (A) The area ratio of the peak derived from the butadiene-based polymer block (B) and the peak derived from the butadiene-based polymer block (B), and the polymer block (A) and the butadiene-based polymer block in the diene-based block copolymer obtained by measuring 1H-NMR A calibration curve was created from the content of (B). A sample of the diene-based block copolymer precipitated by mixing the sampled latex with methanol was measured with a pyrolysis gas chromatogram to determine the difference between the peak derived from the polymer block (A) and the peak derived from the butadiene-based polymer block (B). From the area ratio, the content of the polymer block (A) and the butadiene polymer block (B) in the diene block copolymer was determined using the calibration curve prepared above.

[Measurement of Toluene Insoluble Content]
1 g of the solid content obtained by freeze-drying the latex obtained in the polymerization step 2 was cut into 2 mm squares, placed in a conical beaker and dissolved in toluene for 16 hours. Thereafter, centrifugation was performed, and the gel content was separated using a 200-mesh wire mesh, and the dried mass was measured to calculate the toluene insoluble content from the following formula.
(mass of solid obtained by separating and drying gel content)/(mass of solid obtained by freeze-drying latex containing diene-based block copolymer) x 100

(Measurement of average particle size of latex)
Using a sample obtained by dissolving 0.1 g of the sampled latex in 50 g of pure water, measurement was performed by the dynamic light scattering method using ELSZ-2 manufactured by Otsuka Electronics Co., Ltd., and the average particle size of the latex was calculated by the photon correlation method.

(Measurement of mechanical stability of latex)
The mechanical stability of the latex was measured according to JIS K 6392 using a Maron mechanical stability tester by the following method.
Procedure: After filtering the sampled latex through wire mesh to remove impurities, the filtered latex was adjusted to 20°C and 50 g was weighed into a test container. The test container was mounted on the tester, and the measurement was performed for 10 minutes with a load of 10 kg. After the measurement, the sample in the test container was dried in advance at 125°C for 1 hour and filtered through an 80-mesh wire mesh that had been allowed to cool in a desiccator. It was allowed to cool inside, and the 80-mesh wire mesh and precipitate were weighed. Also, the total solid content (unit: %) of the sampled latex was determined according to JIS K 6387. Next, the coagulation rate (unit: % by mass) of the latex was obtained using the following formula.
[(mass of 80 mesh wire mesh after drying and precipitate (unit: g)) - (mass of 80 mesh wire mesh (unit: g))] / [50 x ((total solid content of latex (unit: mass%) )/100)]×100
The coagulation rate of the latex obtained was taken as the mechanical stability of the latex. As for the mechanical stability of the latex, a level of 1% by mass or less was considered acceptable.

[Preparation of sample for tensile test]
(Preparation of latex containing diene block copolymer)
A butylated reaction product of p-cresol and dicyclopentadiene (trade name: Nocrack PBK", manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.) 2 parts by mass, sodium lauryl sulfate (trade name "Emar 10", manufactured by Kao Corporation) 0.3 parts by mass, and water are added to make the solid content concentration of the formulation It was prepared so as to be 30% by mass, and was mixed at 20° C. for 16 hours using a ceramic ball mill.
(Production of film)
A pottery cylinder having an outer diameter of 50 mm was immersed in a coagulating liquid containing 62 parts by mass of water, 35 parts by mass of potassium nitrate tetrahydrate, and 3 parts by mass of calcium carbonate for 1 second and taken out. After drying for 4 minutes, it was soaked in the latex prepared above for 2 minutes. After that, the film was washed with running water at 45° C. for 1 minute and heated at 130° C. for 30 minutes to remove moisture, thereby producing a film (140×150 mm, thickness: 0.2 mm) for tensile test.

[Evaluation of tensile properties]
After heat-treating the produced film at 130° C. for 30 minutes, the modulus at 500% elongation, tensile strength at break, breaking strength and elongation at break were measured according to JIS K 6251. A modulus at 500% elongation of 3.0 MPa or less, a tensile strength at break of 14 MPa or more, and an elongation at break of 900% or more were regarded as acceptable levels.

[Evaluation of heat aging characteristics]
The produced film was subjected to a heat aging test at 100 ° C. for 22 hours in a forced circulation heat aging tester, and then measured according to JIS K 6251 for modulus at 500% elongation, tensile strength at break and elongation at break. was measured. A modulus at 500% elongation of 3.0 MPa or less, a tensile strength at break of 14 MPa or more, and an elongation at break of 900% or more were considered acceptable.

Claims (13)

A diene-based block copolymer comprising a polymer block (A) and a diene-based polymer block (B),
When the diene block copolymer is 100% by mass,
Containing 5 to 30% by mass of the polymer block (A),
containing 70 to 95% by mass of the diene polymer block (B),
The polymer block (A) contains a monomer unit derived from a monomer that gives a polymer having a glass transition temperature of 80° C. or higher when homopolymerized,
The diene-based block copolymer is obtained by dip-molding a diene-based block copolymer latex containing the diene-based block copolymer, and heat-treating the coating at 130°C for 30 minutes. A diene block copolymer having a measured tensile strength at break of 14 MPa or more. The polymer block (A) is a diene-based block copolymer containing at least one monomer unit selected from the group consisting of aromatic vinyl monomer units, methyl methacrylate monomer units, and acrylonitrile monomer units. Combined. 3. The diene block copolymer according to claim 1, wherein the polymer block (A) has a number average molecular weight of 10,000 or more. The diene-based block copolymer according to any one of claims 1 to 3, wherein the polymer block (B) has a diene-based monomer unit and a polyfunctional monomer unit. 5. The method according to claim 4, wherein the diene-based polymer block (B) contains 0.05 to 10% by mass of the polyfunctional monomer unit when the diene-based polymer block (B) is 100% by mass. The diene-based block copolymer described. The diene-based block copolymer according to claim 4 or 5, wherein the polyfunctional monomer comprises a monomer represented by Chemical Formula (1) or an aromatic polyene monomer.

(In chemical formula (1), R ₁ and R ₂ are each independently hydrogen, chlorine, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, a mercapto group, or a substituted or represents an unsubstituted heterocyclyl group, W ₁ is either a saturated or unsaturated hydrocarbon group, a saturated or unsaturated cyclic hydrocarbon group, a saturated or unsaturated hydrocarbon group containing a hetero atom, or a cyclic hydrocarbon group; Z ₁ represents a structure represented by oxygen, sulfur or —NR ₀ —, where R ₀ is hydrogen, chlorine, a substituted or unsubstituted alkyl group, alkenyl group, aryl group, mercapto group or heterocyclyl group; represents.) A diene-based block copolymer latex comprising the diene-based block copolymer according to any one of claims 1 to 6. 8. The diene block copolymer latex according to claim 7, wherein the diene block copolymer latex contains 20 to 100% by mass of a toluene-insoluble matter with respect to 100% by mass of the diene block copolymer latex. 9. The diene block copolymer latex according to claim 7, wherein the diene block copolymer latex has an average particle size of 300 nm or less as measured by a dynamic light scattering method. The diene-based block copolymer latex according to any one of claims 7 to 9, which is for a dip-molded article. A diene block copolymer latex composition comprising the diene block copolymer latex according to any one of claims 7 to 10. 12. The diene block copolymer latex composition according to claim 11, wherein when the diene block copolymer latex contained in the diene block copolymer latex composition is 100% by mass, a vulcanizing agent and A diene block copolymer latex composition in which the total content of vulcanization accelerators is 5% by mass or less. A molded article comprising the diene block copolymer latex composition according to claim 11 or 12.