Denka Company Limited

Hidehito Otsuka

Kenji Mochizuki

Masao Onozuka

Kiyoshi Sunada

Toru Shiraiwa

A chloroprene copolymer latex containing a chloroprene copolymer having a structural unit derived from chloroprene and a structural unit derived from 2,3-dichloro-1,3-butadiene, in which a toluene insoluble content in the chloroprene copolymer is 50 to 95% by mass, and a modulus at 500% elongation of a film, which is obtained on a base material by dipping the base material in the chloroprene copolymer latex and then performing vulcanization at 100° C. for 30 minutes, according to JIS K 6251 is 4.0 MPa or less.

Chloroprene copolymer latex, method for producing same, vulcanized product, dip molded article and method for producing same

An object of the present invention is to provide a polychloroprene latex with improved rubber coagulability that gives a film superior in strength by dip molding, a polychloroprene latex composition, and a molded article. The polychloroprene latex is prepared by polymerization of 2-chloro-1,3-butadiene alone or by polymerization of raw monomers at least containing 2 -chloro-1,3-butadiene and 2,3-dichloro 1,3-butadiene and has a precipitation rate of 5 to 40%, as calculated according to Equation (I). In Equation (I), A is the mass (g) of the dry product, which is obtained by adding 50 ml of saturated aqueous solution of calcium hydroxide at 23&#xb0; C. to 50 g of a latex having a solid matter concentration adjusted to 45 to 65 mass % at a liquid temperature of 23&#xb0; C. over 2 minutes, filtering and collecting the generated precipitate with a 80 -mesh wire mesh, and drying the precipitate at 110&#xb0; C. for 3 hours; B is the mass of the latex before the dropwise addition (50 g); and C is the solid matter concentration (mass %) of the latex before the dropwise addition. 

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Itoigawa, Japan

Hidehito Otsuka