To provide a statistical copolymer containing a chloroprene monomer unit and an unsaturated nitrile monomer unit which has a satisfactory oil resistance. A method for producing a statistical copolymer containing a chloroprene monomer unit and an unsaturated nitrile monomer unit includes a step for conducting continuous addition or 10 cycles or more of intermittent portionwise addition of the chloroprene monomer after initiation of a polymerization reaction is provided. A rubber composition using a statistical copolymer according to the invention or a vulcanized molded article containing the rubber composition is excellent in terms of oil resistance, mechanical strength, compression set at a low temperature and flex fatigue resistance.

To provide a statistical copolymer containing a chloroprene monomer unit and an unsaturated nitrile monomer unit which has a satisfactory oil resistance. A method for producing a statistical copolymer containing a chloroprene monomer unit and an unsaturated nitrile monomer unit includes a step for conducting continuous addition or 10 cycles or more of intermittent portionwise addition of the chloroprene monomer after initiation of a polymerization reaction is provided. A rubber composition using a statistical copolymer according to the invention or a vulcanized molded article containing the rubber composition is excellent in terms of oil resistance, mechanical strength, compression set at a low temperature and flex fatigue resistance.

Disclosed are a polymer having a narrow molecular weight distribution prepared by living radical and a polymer manufacturing method comprising a step of performing living radical polymerization using 0.005 to 0.5 parts by mass of an oxygen radical scavenger per 100 parts by mass of a radical polymerizable monomer.

Disclosed are a polymer having a narrow molecular weight distribution prepared by living radical and a polymer manufacturing method comprising a step of performing living radical polymerization using 0.005 to 0.5 parts by mass of an oxygen radical scavenger per 100 parts by mass of a radical polymerizable monomer.

A chloroprene rubber composition comprising 0.8 to 4 parts by weight of 2,4,6-trimercapto-s-triazine and 0.5 to 4.5 parts by weight of tetrabenzylthiuram disulfide based on 100 parts by weight of chloroprene rubber. The chloroprene rubber composition maintains processability (scorch time) and productivity (crosslinking rate) equivalent to those of conventionally used crosslinking systems, without using substances subject to environmental regulations in crosslinking systems, and at the same time, improves physical properties, such as strength, elongation, and compression set characteristics.

A chloroprene rubber composition comprising 0.8 to 4 parts by weight of 2,4,6-trimercapto-s-triazine and 0.5 to 4.5 parts by weight of tetrabenzylthiuram disulfide based on 100 parts by weight of chloroprene rubber. The chloroprene rubber composition maintains processability (scorch time) and productivity (crosslinking rate) equivalent to those of conventionally used crosslinking systems, without using substances subject to environmental regulations in crosslinking systems, and at the same time, improves physical properties, such as strength, elongation, and compression set characteristics.

The present invention relates to a method for producing a chloroprene polymer latex, comprising: adding (B) a sodium. salt of a naphthalene sulfonate formaldehyde condensate and. (C) sodium dodecylbenzenesulfonate to a monomer solution that contains (A-1) 2-chloro-1,3-butadiene (chloroprene) or a monomer solution that contains (A-1) 2-chloro-1,3-butadiene (chloroprene) and (A-2-1) 2,3-dichloro-1,3-butadiene, and performing polymerization. Consequently, the present invention enables the production of a chloroprene polymer latex which is suppressed in aggregates that are generated during the production of a chloroprene polymer latex having a high solid content.

The present invention relates to a method for producing a chloroprene polymer latex, comprising: adding (B) a sodium. salt of a naphthalene sulfonate formaldehyde condensate and. (C) sodium dodecylbenzenesulfonate to a monomer solution that contains (A-1) 2-chloro-1,3-butadiene (chloroprene) or a monomer solution that contains (A-1) 2-chloro-1,3-butadiene (chloroprene) and (A-2-1) 2,3-dichloro-1,3-butadiene, and performing polymerization. Consequently, the present invention enables the production of a chloroprene polymer latex which is suppressed in aggregates that are generated during the production of a chloroprene polymer latex having a high solid content.

The present invention provides methods for surface-modifying a rubber vulcanizate or a thermoplastic elastomer, which can cost-effectively provide a variety of functions, such as sliding properties, according to the application. The present invention relates to a method for surface-modifying a rubber vulcanizate or a thermoplastic elastomer as a target for modification, the method including: step 1 of forming polymerization initiation points on a surface of the modification target; and step 2 of radically polymerizing a non-functional monomer, starting from the polymerization initiation points, to grow non-functional polymer chains, and then radically polymerizing a fluoropolyether segment-containing functional monomer to grow functional polymer chains.

The present invention provides methods for surface-modifying a rubber vulcanizate or a thermoplastic elastomer, which can cost-effectively provide a variety of functions, such as sliding properties, according to the application. The present invention relates to a method for surface-modifying a rubber vulcanizate or a thermoplastic elastomer as a target for modification, the method including: step 1 of forming polymerization initiation points on a surface of the modification target; and step 2 of radically polymerizing a non-functional monomer, starting from the polymerization initiation points, to grow non-functional polymer chains, and then radically polymerizing a fluoropolyether segment-containing functional monomer to grow functional polymer chains.