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.

What is claimed is: 
     
         1 . A cross-linked waterproof membrane comprising:
 a support carrier comprising a spunbond polypropylene nonwoven fabric having a first surface and a second surface,
 said spunbond polypropylene nonwoven fabric having a cured precoat therein,
 wherein the cured precoat fills spaces between fibers in the first surface of the spunbond polypropylene nonwoven fabric without forming a film on the spunbond polypropylene nonwoven fabric, thereby forming a support carrier first surface, and 
 
   a topcoat layer bonded to said support carrier first surface, the topcoat layer comprising cross-linked polyurethane.   
     
     
         2 . The cross-linked waterproof membrane of  claim 1 , wherein the topcoat layer has a thickness of 0.4 to 1.9 mm. 
     
     
         3 . The cross-linked waterproof membrane of  claim 1 , wherein the precoat comprises a polyurethane. 
     
     
         4 . The cross-linked waterproof membrane of  claim 3 , wherein the precoat comprises a mixture of a polyurethane and a polypropylene. 
     
     
         5 . A waterproof multilayer system for roofing, comprising in order from a roof:
 a) roofing primer;   b) adhesive layer;   c) the cross-linked waterproof membrane of  claim 1 ,
 wherein said cross-linked waterproof membrane has a topcoat surface and a support carrier second surface that is the second surface of the spunbond polypropylene nonwoven fabric, 
 the support carrier second surface of the cross-linked waterproof membrane adhered to the roofing primer by the adhesive layer; and 
   d) top finish layer comprising cured polyurethane on the topcoat surface of the cross-linked waterproof membrane.