Bridgestone Tire Company Limited

Yoshihiko Fujii

Shiro Anzai

Yoji Watabe

Junji Furukawa

Yutaka Iseda

Fumio Odaka

Scrap vulcanized rubber is reclaimed by mixing with a reclaiming agent selected from (a) 1,8-diazabicyclo-[5,4,0]-undecene-7, (DBU) (b) phenol salts of DBU, (c) carboxylic acid salts of DBU, (d) thiuramsulfide compounds, (e) aromatic disulfides, and (f) benzene sulfinic acid compounds or benzene sulfonyl hydrazides, provided that (e) aromatic disulfides are not used alone. Aliphatic or alicyclic amines may be used together with a compound selected from compounds (a)-(f) to enhance the reclaiming effect.

Process for reclaiming scrap vulcanized rubber

A polyurethane composition is produced by mixing (a) 100 parts by weight of prepolymer having terminal isocyanate groups and having a number average molecular weight in the range of from 800 to 20,000, (b) 5 - 30 parts by weight of a radical polymerizable vinyl compound, and (c) 0.05 - 1.0 part by weight of a radical initiator, adding (d) a curative selected from the group consisting of polyamine and polyol, and curing the resulting mixture by heating at 70 - 140.degree. C, the equivalent ratio of the active hydrogen of (d) to the isocyanate groups of (a) being in the range of from 0.8 to 1.2.

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Higashimurayama, Japan

Yoshihiko Fujii