SELF-HEALING BENTONITE SHEET MATERIAL COMPOSITE ARTICLE

SELF-HEALING BENTONITE SHEET MATERIAL COMPOSITE ARTICLE The present invention relates to a layered water sealing article of manufacture including a layer of a flexible sheet material adhered to a layer of a composition comprising a non-hydrated water-swellable clay intimately contacted with a polypropene, polybutene, or mixtures thereof particularly useful as a water barrier. The water swellable clay composition can be adhered to the flexible sheet material in any manner, such as by extruding the composition in sheet form onto a layer of sheet material. The clay composition layer is sufficiently tacky to adhere to the sheet material on one major surface, and is sufficiently tacky for adherence to a wall or conduit, floor or roof on an exposed major surface in areas of potential water flow to prevent the seepage of water through the bentonite clay composition layer. In one embodiment, the clay composition layer includes a polypropene and/or a polybutene and an elastomer, such as butyl rubber, having sufficient resilience to stretch or expand with the expanding water-swellable clay composition upon hydration and to aid in maintaining the structural integrity and cohesiveness of the clay composition. In another embodiment, the clay composition layer comprises a water-swellable clay, an elastomer, and any plasticizer compatible with the elastomer.