C.i. Kasei Company, Limited

Kuraray Isoprene Chemical Co. Ltd.

Toshihiro Kimura

Hiroshi Harima

Yoshihiro Yoshioka

Kazuhiro Takasaki

The invention provides a novel watertight rubbery sealing material of which the water-swellability is markedly insusceptible to the adverse influence of compression of the material in a dry condition. The watertight sealing material is a shaped and vulcanized body of a water-swellable rubber composition comprising, in a limited proportion, (a) a chloroprene rubber, (b) a highly water-absorptive resin such as a crosslinked polyacrlylic acid in the form of a sodium salt, (c) a rubbery polymer unvulcanizable with a metal oxide-based vulcanizing agent and (d) a metal oxide-based vulcanizing agent which is preferably a combination of magnesium oxide and zinc oxide.

Compression-resistant water-swellable rubber composition and watertight

The invention provides a novel water-swellable caulking material which is a composite body of stratified structure composed of at least one rubbery layer swellable in water comprising highly water absorbing resin dispersed in the matrix of a rubber and at least one rubbery layer not swellable in water integrally bonded together, which latter serves to resist the expansion of the former layer when swollen in water in the directions other than the direction perpendicular to the plane of the layers. The inventive caulking material can exhibit unexpectedly excellent water sealing effect with easiness in handling in addition to the rapidity in water absorption by virtue of the structure thereof preventing the expansion of the material in the directions of length and width without decreasing the expansion in the direction of thickness.

Growing community of inventors

Ageo, Japan

Toshihiro Kimura