Abstract: A (meth)acrylate-based block copolymer including a polymer block and a (meth)acrylate-based polymer block, wherein: the (meth)acrylate-based block copolymer contains 5 to 30% by mass of the polymeric block and 70 to 95% by mass of the (meth)acrylate-based polymer block with respect to 100% by mass of the (meth)acrylate-based block copolymer; the polymer block has a monomer unit derived from a monomer; when the monomer is polymerized alone, a polymer with a glass transition temperature of 80° C. or higher can be obtained; and a tensile strength at break measured in accordance with JIS K 6251 of a film obtained by immersion-molding a (meth)acrylate-based block copolymer latex containing the (meth)acrylate-based block copolymer and heat-treating at 130° C. for 30 minutes is 14 MPa or more.

Abstract: A method for producing a chloroprene polymer composition containing a chloroprene polymer, the method including: a polymerization step of polymerizing a monomer containing chloroprene at a polymerization rate of 20% or more to obtain a polymer composition containing a chloroprene polymer; and a mixing step of mixing the polymer composition with a rosin containing at least one conjugate resin acid component selected from the group consisting of abietic acid, neoabietic acid, palustric acid, levopimaric acid, and salts thereof, in which a mixed amount of the rosin in the mixing step is more than 0 parts by mass and 23 parts by mass or less with respect to 100 parts by mass of solid content of the polymer composition.

Abstract: A rubber material containing a sulfur-modified chloroprene polymer, in which a content X (% by mass) of sulfur constituting the sulfur-modified chloroprene polymer and a total amount Y (% by mass) of a conjugate resin acid and a salt of a conjugate resin acid, on the basis of a total amount of the rubber material, satisfy Expression (A) below, and the total amount Y is 1.00% by mass or more. 13.90X?5.

Abstract: A chloroprene-based block copolymer, a latex, a latex composition, and a rubber composition that can produce a product with excellent tensile properties and flexibility without the use of a vulcanizing agent or a vulcanizing accelerator having a chloroprene-based block copolymer, contains 5 to 30% by mass of a polymer block (A) and 70 to 95% by mass of a chloroprene-based polymer block (B), wherein the polymer block (A) is derived from a monomer, when the monomer is polymerized alone, a polymer with a glass transition temperature of 80° C. or higher can be obtained and the chloroprene-based polymer block (B) includes a chloroprene monomer unit and a polyfunctional monomer unit.

Abstract: A chloroprene-based block copolymer, a latex, a latex composition, and a rubber composition that can produce a product with excellent flexibility and tensile properties without the use of a vulcanizing agent or a vulcanizing accelerator. A chloroprene-based block copolymer, includes 5 to 30% by mass of a polymer block (A) and 70 to 95% by mass of a chloroprene-based polymer block (B), wherein: the polymer block (A) is derived from a monomer; when the monomer is polymerized alone, a polymer with a glass transition temperature of 80° C. or higher can be obtained; the chloroprene-based polymer block (B) includes a chloroprene monomer; and the chloroprene-based block copolymer has a toluene insoluble content of 20 to 100% by mass with respect to 100% by mass of the chloroprene-based block copolymer.

Abstract: A chloroprene-based block copolymer latex, including a chloroprene-based block copolymer, wherein: the chloroprene-based block copolymer contains 5 to 30% by mass of a polymer block (A) and 70 to 95% by mass of a chloroprene-based polymer block (B); the polymer block (A) is derived from a monomer; when the monomer is polymerized alone, a polymer with a glass transition temperature of 80° C. or higher can be obtained; the chloroprene-based polymer block (B) includes a chloroprene monomer unit; and when the chloroprene-based block copolymer latex is molded by immersion molding to obtain a film and then the film is heat-treated at 130° C. for 30 minutes, a tensile strength at break measured in accordance with JIS K6251 of the film is 17 MPa or more is provided.

Abstract: An immersion-molded body, wherein: the immersion-molded body is obtained using a latex; the latex comprises a chloroprene-based block copolymer; the chloroprene-based block copolymer contains 5 to 30% by mass of a polymer block (A) and 70 to 95% by mass of a chloroprene-based polymer block (B); the polymer block (A) is derived from a monomer; when the monomer is polymerized alone, a polymer with a glass transition temperature of 80° C. or higher can be obtained; the chloroprene-based polymer block (B) includes a chloroprene monomer unit; and when the immersion-molded body is heat-treated at 130° C. for 30 minutes, a tensile strength at break of the heat-treated immersion-molded body measured in accordance with JIS K6251 is 17 MPa or more.

Abstract: [Problem] To provide a cross-polymer having excellent softness, tensile properties, transparency and anti-blocking properties, and a medical single-layer tube using the same. [Solution] A cross-copolymer containing, by 75-95 mass %, main chains comprising aromatic vinyl/olefin-based copolymers comprising 8.99-15.99 mol % of aromatic vinyl monomer units, 84-91 mol % of olefin monomer units and 0.01-0.5 mol % of aromatic polyene monomer units; and by 5-25 mass %, cross-chains comprising polymers comprising aromatic vinyl monomer units; wherein, based on differential scanning calorimetry (DSC) in which the cross-copolymer is cooled to ?50° C. in a 30 mL/min nitrogen flow, then heated to 180° C. at a temperature increase rate of 10° C./min, re-cooled to ?50° C., and heated to 180° C. at a temperature increase rate of 10° C./min, the cross-copolymer has a top temperature of melting peak of 60-80° C., and a heat of fusion of 45-75 J/g, as calculated from the area of the DSC curve between ?20° C. and 130° C.

Abstract: [Problem] To provide a thermoplastic elastomer resin composition that excels in tensile breaking strength, softness, oil resistance and scratch resistance, and that has good heat fusion ability with respect to polyolefin resins. [Solution] A thermoplastic elastomer resin composition consisting of: 15 to 89 mass % of a cross-copolymer having a polymer consisting of aromatic vinyl monomer units as a cross-chain structure on an aromatic vinyl-olefin-aromatic polyene copolymer main chain consisting of 9.99 to 29.99 mol % of aromatic vinyl monomer units, 70 to 90 mol % of olefin monomer units and 0.01 to 0.5 mol % of aromatic polyene monomer units; 1 to 55 mass % of a hydrogenated block copolymer; and 10 to 60 mass % of a polypropylene resin.