Waterproof membrane

Abstract

The invention relates to a waterproof membrane for building applications comprising at least one support carrier and at least one layer of a cross-linked coating composition comprising at least one polyurethane. The invention also relates to a waterproof membrane comprising at least one support carrier and at least one layer of a cross-linked coating composition comprising at least one polyurethane, an optional pre-coating layer to facilitate the manufacturing process, and to join the support carrier with the cross-linked coating composition in the most optimal and durable manner to achieve good surface appearance and chemical bonding between reinforcing carrier and crosslinked polyurethane coating. The waterproof membrane can be prepared and installed with lower cost in comparison to current flat roof waterproofing systems based on liquid two-component polyurethane systems.

1 . A waterproof membrane comprising:
 A. at least one support carrier, and   B. at least one topcoat layer of a two component polyurethane coating composition comprising:
 a) at least one material having hydroxyl groups, and 
 b) at least one polyisocyanate cross-linking agent with free isocyanate groups. 
   
     
     
         2 . The waterproof membrane of  claim 1 , wherein the at least one support carrier is a nonwoven or woven fabric. 
     
     
         3 . The waterproof membrane of  claim 1 , wherein the at least one support carrier is made of polyethylene, polypropylene, polyester or polyamide polymers or combinations or mixed polymers thereof. 
     
     
         4 . The waterproof membrane of  claim 1 , wherein the at least one support carrier is made of mineral woven or nonwoven fabric. 
     
     
         5 . The waterproof membrane of  claim 1 , wherein the support carrier is coated with a pre-coating which provides adhesion between said support carrier and the topcoat layer. 
     
     
         6 . The waterproof membrane of  claim 5 , wherein the topcoat composition further comprises a catalyst for the curing reaction between the hydroxyl groups of component a) and the isocyanate groups of component b). 
     
     
         7 . A waterproof system for building applications comprising the waterproof membrane of  claim 1 . 
     
     
         8 . The waterproof system of  claim 7  comprising in addition at least one of the following layers: a primer layer, a layer of an adhesive, an elastomeric membrane different from the waterproof membrane and a top finish layer. 
     
     
         9 . The waterproof system of  claim 8 , wherein the primer layer is a primer layer based on two-component polyurethane and wherein the adhesive is a liquid polyurethane adhesive.