Waterproofing Membrane

Abstract

Disclosed is a waterproofing membrane that comprises a carrier sheet, a pressure sensitive adhesive layer on one surface of the carrier sheet, and a protective coating layer on the adhesive layer. The protective coating layer comprises polyvinyl acetate (PVAc). The protective coating layer protects the membrane against weather exposure, tolerates foot traffic and strongly adheres to concrete cast against it.

1 . A waterproofing membrane in the form of a sheet-like laminate comprising a carrier sheet, a pressure sensitive adhesive layer on one surface of the carrier sheet, and a protective coating layer on the adhesive layer, wherein the protective coating layer comprises polyvinyl acetate homopolymer. 
     
     
         2 . The waterproofing membrane of  claim 1  wherein the protective coating layer comprises, by weight of the protective coating layer (exclusive of any optional filler or pigment), at least 40% polyvinyl acetate homopolymer, more preferably at least 50% polyvinyl acetate homopolymer, or most preferably at least 60% polyvinyl acetate homopolymer. 
     
     
         3 . The waterproofing membrane of  claim 1  or  2  wherein the protective coating layer includes a softening material for the polyvinyl acetate homopolymer. 
     
     
         4 . The waterproofing membrane of  claim 3  wherein the softening material comprises a plasticizer for polyvinyl acetate homopolymer. 
     
     
         5 . The waterproofing membrane of  claim 3  wherein the softening material comprises a flexible polymer that is miscible or compatible with polyvinyl acetate homopolymer. 
     
     
         6 . The waterproofing membrane of  claim 5  wherein the flexible polymer comprises a polymer or copolymer selected from the group consisting of chlorinated paraffins, polymethylacrylate, polyethylacrylate, copolymers of methyl acrylate and acrylic acid, copolymers of ethyl acrylate and acrylic acid, copolymers of butyl acrylate and acrylic acid, copolymers of vinyl acetate with ethylene, copolymers of vinyl acetate and acrylic esters including methyl acrylate, ethyl acrylate, butyl acrylate, and ethyl-hexyl acrylate, copolymers of vinyl acetate and vinyl versatate, and copolymers of vinyl acetate and vinyl laurate. 
     
     
         7 . The waterproofing membrane of  claim 1  additionally including a coating or dusting of finely divided inorganic particulate material on the exposed surface of the protective coating layer. 
     
     
         8 . The waterproofing membrane of  claim 1  wherein the carrier sheet comprises a film comprising polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-olefin copolymer, ethylene-vinyl acetate copolymer, polyvinyl acetate, polyethyl acrylate, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene terephthalate, polyvinyl chloride, polyamide and combinations thereof, or a woven or non-woven fabric comprising polyethylene, polypropylene, polyolefin, polyethylene terephthalate, glass, or polyamide. 
     
     
         9 . The waterproofing membrane of  claim 1  wherein the adhesive layer comprises a synthetic pressure sensitive adhesive or a rubber modified bitumen pressure sensitive adhesive. 
     
     
         10 . The waterproofing membrane of  claim 1  wherein the adhesive layer comprises a synthetic pressure sensitive adhesive comprising a butyl rubber based adhesive, a polyisobutylene based adhesive, a butyl based adhesive, an acrylic based adhesive, a vinyl ether based adhesive, a styrene-isoprene-styrene (SIS) based adhesive, a styrene-ethylene-butylene-styrene (SEBS) based adhesive, a styrene-butadiene-styrene (SBS) based adhesive, a styrene-butadiene rubber (SBR) based adhesive, or a combination of two or more of these materials. 
     
     
         11 . The waterproofing membrane according to  claim 1  additionally comprising a removable release sheet on the protective coating layer. 
     
     
         12 . A method of waterproofing a concrete structure comprising applying a waterproofing membrane in accordance with any preceding claim to a building substrate or concrete form with the protective coating layer of said membrane facing the area into which the concrete will be cast, and casting concrete such that it contacts the protective coating layer of the membrane.