POLYURETHANE FOAMS SUITABLE FOR HIGH FREQUENCY WELDING AND PROCESS FOR PRODUCING THE SAME

摘要

This invention relates to polyurethane foams capable of being welded by high frequency welding and a process for producing the same, characterized by the addition of certain ammonium salts of acids containing phosphorus to the starting components for the polyurethane foam in order that the polyurethane starting materials and the polyurethanes contain from 0.1 to 10%, by weight, of ammonium salts of phosphorus-containing acids. Phosphorus-containing ammonium salts which are available in the liquid form and completely soluble in polyols are particularly suitable with salts of phosphoric acid mono- and dibutyl esters, dialkyl phosphinic acids, alkyl phosphonic acids and alkyl phosphonic acid monomethyl esters being preferred. The addition of these acids significantly increases the dielectric loss factor of thermoplastic polyurethane foams and, therefore, also considerably increases their capacity for being welded by high frequency welding.