Abstract: A method for producing a polymer latex, including an emulsification step of emulsifying a polymer solution obtained by dissolution of synthetic polyisoprene and/or a styrene-isoprene-styrene block copolymer having a molecular weight distribution of 1.0 to 2.6 in an organic solvent, in water in the presence of a surfactant, to thereby obtain an emulsified liquid, wherein as the synthetic polyisoprene and/or styrene-isoprene-styrene block copolymer, used are/is synthetic polyisoprene and/or a styrene-isoprene-styrene block copolymer which, when dissolved in an organic solvent to thereby be formed into a polymer solution having a viscosity at a temperature of 60° C. of 20,000 cps, have/has a solid content concentration in the range of 10 to 60% by weight.

Abstract: A latex of an acid-modified conjugated diene polymer including the acid-modified conjugated diene polymer obtained by modifying a conjugated diene polymer with an acid group-containing compound, in which a content of a structural unit derived from the acid group-containing compound is 0.2 to 0.7 parts by weight with respect to 100 parts by weight of the acid-modified conjugated diene polymer; a content of a water-soluble polymer in the latex is 2 parts by weight or less with respect to 100 parts by weight of the acid-modified conjugated diene polymer; when a solids content of the latex is adjusted to 60 wt %, a viscosity at 25° C. is 800 mPa·s or less; and when the solids content of the latex is adjusted to 50 wt %, the viscosity at 25° C. is 300 mPa·s or less.

Abstract: A method for producing a polymer latex includes: a preparation step of reducing the weight average molecular weight of a conjugated diene polymer (A) by 20 to 70 mass %, thereby obtaining an organic solvent solution containing a conjugated diene polymer (B) having a weight average molecular weight lower than that of the conjugated diene polymer (A); and an emulsification step of emulsifying the organic solvent solution in water in the presence of a surfactant, thereby obtaining a polymer latex.

Abstract: A latex of a synthetic rubber, wherein the content rate of a particle having a particle size of 5 ?m or more in a particle size distribution of a synthetic rubber particle included in the latex, as determined on a number basis, is less than 3,000 ppm by weight. A latex of a synthetic rubber is excellent in mechanical stability and can provide a film molded article such as a dip molded article excellent in tensile strength and elongation.

Abstract: A polymer latex, including a polymerization step of polymerizing a monomer in organic solvent to thereby obtain polymer solution of synthetic polyisoprene and/or styrene-isoprene-styrene block copolymer, antioxidant addition step of adding antioxidant to the polymer solution of synthetic polyisoprene and/or styrene-isoprene-styrene block copolymer at proportion of 0.01-1.00 parts by weight per 100 parts by weight of the synthetic polyisoprene and/or styrene-isoprene-styrene block copolymer, and emulsification step of emulsifying the polymer solution which the antioxidant is added, in water in the presence of a surfactant, to thereby obtain polymer latex, wherein the emulsification performs in the emulsification step so the ratio D75/D25 of the volume particle size D75 at a cumulative frequency of 75% to the volume particle size D25 at a cumulative frequency of 25% of a particle of the synthetic polyisoprene and/or styrene-isoprene-styrene block copolymer included in the polymer latex is 1.90 or more and 2.

Abstract: A latex composition containing a carboxy-modified polymer latex, a xanthogen compound, and a typical metal compound in a form other than an oxide. This latex composition has excellent stability, can avoid delayed (Type IV) allergic reactions in addition to immediate (Type I) allergic reactions, and can provide a molded film, such as a dip-molded product, having excellent tear strength and tensile strength. Also a molded film and a substrate with an adhesive layer which are obtained using the latex composition.

Abstract: A synthetic polyisoprene latex containing synthetic polyisoprene, wherein the synthetic polyisoprene constituting the synthetic polyisoprene latex includes a low-molecular weight synthetic isoprene chain having a molecular weight of less than 1,000,000 at a content rate of 10 to 70% by weight and a high-molecular weight synthetic isoprene chain having a molecular weight of 1,000,000 or more at a content rate of 30 to 90% by weight. Also, a method for producing the synthetic polyisoprene latex, wherein the synthetic polyisoprene containing the low-molecular weight synthetic isoprene chain and the high-molecular weight synthetic isoprene chain is obtained by polymerizing a monomer containing isoprene in an organic solvent by use of an organic alkali metal catalyst.

Abstract: A method for producing a synthetic polyisoprene latex, including a step of mixing a latex of synthetic polyisoprene (A) synthesized by use of a Ziegler type catalyst and a latex of synthetic polyisoprene (B) synthesized by use of an organic alkali metal catalyst at a weight ratio of “synthetic polyisoprene (A): synthetic polyisoprene (B)=10:90 to 90:10”. In the method, preferably, the weight average molecular weight of the synthetic polyisoprene (A) is 100,000 to 3,000,000 and the weight average molecular weight of the synthetic polyisoprene (B) is 1,000,000 to 5,000,000.

Abstract: A latex composition contains a carboxy-modified conjugated diene polymer latex, a xanthogen compound, and a metal oxide.

Abstract: A method for producing a polymer latex, includes a step of emulsifying a polymer solution of a synthetic polyisoprene and/or a styrene-isoprene-styrene block copolymer, in water in the presence of a rosin and/or a rosin metal salt, thereby obtaining an emulsified liquid, wherein the rosin and/or the rosin metal salt to be used have/has a total content rate of abietic acid, neoabietic acid and palustric acid, and salts thereof, of 5% by weight or less.

Abstract: A method for producing a synthetic rubber, the method including: an emulsification step of continuously feeding a solution or a dispersion of a synthetic rubber obtained by dissolving or dispersing the synthetic rubber in an organic solvent and an aqueous solution of an emulsifier to a mixer and mixing to continuously obtain an emulsion; a first removal step of removing the organic solvent from the emulsion continuously obtained in the emulsification step in a container while the emulsion is continuously transferred to the container regulated to a pressure condition of 700 to 760 mmHg; and a second removal step of removing the organic solvent from the emulsion that has undergone the first removal step under a pressure of less than 700 mmHg.

Abstract: A latex composition containing a conjugated diene polymer latex and a medium-chain fatty acid glyceride, wherein a content proportion of the medium-chain fatty acid glyceride is 1 to 40 parts by weight with respect to 100 parts by weight of the conjugated diene polymer. In the present invention, a medium-chain fatty acid forming the medium-chain fatty acid glyceride is preferably a fatty acid having 6 to 18 carbon atoms. In the present invention, the medium-chain fatty acid glyceride is preferably a medium-chain fatty acid triglyceride. The latex composition preferably further contains a crosslinking agent.

Abstract: A method for producing a polymer latex, including an emulsification step of mixing a polymer solution obtained by dissolution of synthetic polyisoprene and/or a styrene-isoprene-styrene block copolymer in an organic solvent, with an aqueous solution including 0.1 to 30 parts by weight of a rosinate based on 100 parts by weight in total of the synthetic polyisoprene and the styrene-isoprene-styrene block copolymer, and emulsifying the resultant in water to thereby obtain an emulsified liquid, a solvent removal step of removing the organic solvent in the emulsified liquid, and a concentration step of concentrating the emulsified liquid from which the organic solvent is removed, and also adjusting the content rate of the rosinate in the emulsified liquid after concentration, in the range of 0.1 to 3 parts by weight based on 100 parts by weight in total of the synthetic polyisoprene and the styrene-isoprene-styrene block copolymer in the emulsified liquid.

Abstract: A latex of a synthetic rubber, wherein the content rate of a particle having a particle size of 5 ?m or more in a particle size distribution of a synthetic rubber particle included in the latex, as determined on a number basis, is less than 3,000 ppm by weight. A latex of a synthetic rubber is excellent in mechanical stability and can provide a film molded article such as a dip molded article excellent in tensile strength and elongation.

Abstract: A method for producing a polymer latex, includes: a stirring step of adding water to a polymer solution obtained by dissolution of a synthetic rubber in an organic solvent, to allow water to be stirred in the polymer solution, thereby providing a water-stirred polymer solution (A); an aqueous phase removal step of removing an aqueous phase from the water-stirred polymer solution (A), thereby providing an aqueous phase-removed polymer solution (B); an emulsification step of mixing the aqueous phase-removed polymer solution (B) with an aqueous solution including a surfactant, for emulsification in water, thereby obtaining an emulsified liquid (C); a solvent removal step of removing an organic solvent in the emulsified liquid (C); and a concentration step of concentrating the emulsified liquid from which the organic solvent is removed (D).

Abstract: A polymer latex, including a polymerization step of polymerizing a monomer in organic solvent to thereby obtain polymer solution of synthetic polyisoprene and/or styrene-isoprene-styrene block copolymer, antioxidant addition step of adding antioxidant to the polymer solution of synthetic polyisoprene and/or styrene-isoprene-styrene block copolymer at proportion of 0.01-1.00 parts by weight per 100 parts by weight of the synthetic polyisoprene and/or styrene-isoprene-styrene block copolymer, and emulsification step of emulsifying the polymer solution which the antioxidant is added, in water in the presence of a surfactant, to thereby obtain polymer latex, wherein the emulsification performs in the emulsification step so the ratio D75/D25 of the volume particle size D75 at a cumulative frequency of 75% to the volume particle size D25 at a cumulative frequency of 25% of a particle of the synthetic polyisoprene and/or styrene-isoprene-styrene block copolymer included in the polymer latex is 1.90 or more and 2.

Abstract: A method for producing a polymer latex, including an emulsification step of emulsifying a polymer solution obtained by dissolution of synthetic polyisoprene and/or a styrene-isoprene-styrene block copolymer having a molecular weight distribution of 1.0 to 2.6 in an organic solvent, in water in the presence of a surfactant, to thereby obtain an emulsified liquid, wherein as the synthetic polyisoprene and/or styrene-isoprene-styrene block copolymer, used are/is synthetic polyisoprene and/or a styrene-isoprene-styrene block copolymer which, when dissolved in an organic solvent to thereby be formed into a polymer solution having a viscosity at a temperature of 60° C. of 20,000 cps, have/has a solid content concentration in the range of 10 to 60% by weight.

Abstract: A latex composition is formed by adding an aqueous solution of an aluminum compound to a latex of a carboxyl group-containing synthetic polyisoprene and/or a carboxyl group-containing styrene-isoprene-styrene block copolymer. In the latex composition, the aqueous solution of an aluminum compound preferably has a pH of 5 to 13. In the latex composition, the aqueous solution of an aluminum compound is preferably an aqueous solution of a metal salt of aluminate.

Abstract: An object of the invention is to provide a laminate which is good in adhesiveness between a substrate and a thin film laminated thereon by a dry film-forming method such as a chemical vapor growth method or a vacuum evaporation method even if the substrate is a polymer substrate made of a nonpolar polymer; and a process for producing the same. In order to attain the above-mentioned object, the invention provides a laminate comprising a polymer substrate, a primer layer comprising a cyclized rubber which is a conjugated diene polymer cyclized product or a derivative thereof, the layer being formed on the surface of the polymer substrate, and a thin film laminated on the surface of the primer layer by a dry film-forming method; and a process for producing the same.

Abstract: A polymerizable composition suitable as an electric material and the like used in an electric circuit board, which comprises a norbornene monomer, a metathesis polymerization catalyst, and a chain transfer agent composed of a compound represented by formula (A): CH2?CH—Y—OCO—CR1?CH2 wherein Y represents a divalent hydrocarbon group having 3 to 20 carbon atoms, and R1 represents a hydrogen atom or a methyl group. By further comprising a crosslinking agent in the polymerizable composition, obtaining a crosslinkable resin by carrying out bulk polymerization, and crosslinking the crosslinkable resin to obtain a molded article and a crosslinked resin composite having excellent characteristics such as electric insulation, adhesion, mechanical strength, heat resistance, dielectric properties and the like.