C.i. Kasei Company, Limited

Kuraray Isoprene Chemical Co. Ltd.

Kazuhiro Takasaki

Hiroshi Shinjo

Hiroshi Harima

Michiyoshi Terauchi

Yoshihiro Yoshioka

Toshihiro Kimura

Takahide Kameda

A joint sealing member such as may be used in civil engineering works for providing a watertight seal between joint members is disclosed. In one embodiment, the sealing member takes the form of a band-like member constituted by a central portion made of a water expansible material which expands upon absorbing water and lateral nonexpansible portions made of a rubber which does not change in volume when in contact with water. The thickness of the central portion is greater than that of the lateral portions. In another embodiment, the joint member takes the form of a belt-like base plate made of a water expansible material having one or more longitudinally extending rib-like ridge portions formed on one side thereof.

Joint sealing member

A seal, constituted by a water-expansible portion and a water-unexpansible portion, prevents water from leaking in a construction joint. The expansible portion surrounds the unexpansible portion everywhere except on a side of the unexpansible portion which is adhered to one of two mutually facing surfaces of the construction joint. The unexpansible portion is sized, relative to the overall size of the seal, particularly in the width dimension, so that it adheres with sufficient strength to one of the mutually facing surfaces of the construction joint so as not to become pulled off in use. An effective seal thus is maintained even in a swollen state.

Appliance for preventing water from leaking through joint

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.

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Warabi, Japan

Kazuhiro Takasaki