Verfahren zur Herstellung von mit Polyurethan beschichteten Substraten und solche Substrate.

摘要

Substrates having successive layers of a cellular polyurethane and a non-cellular polyurethane are prepared using certain siloxane-polyether block copolymers in the non-cellular polyurethane formulation. Said block copolymers contain 10 to 30 weight percent dialkylsiloxane units, 30 to 70 weight percent oxyethylene units and, optionally, up to 55 weight percent other oxyalkylene units. The use of the block copolymer reduces or eliminates the formation of a bubble line at the interface of the polyurethane layers, thereby improving physical and cosmetic properties of the carpet.