method for preparation of samenpersbaar, veelcellig afdichtingsmateriaal with delayed recovery of shape shifting, and it produced, formed afdichtingsmateriaal.

摘要

A moulding, particularly for sealing purposes comprises an at least partly open-cell elastic non-rigid polyurethane foam plastic, impregnated with a mixture of either polyvinyl acetate and a plasticizer therefor or of a copolymer of vinyl acetate and a di-(C1- 5 alkyl)ester of maleic acid and optionally a plasticizer for this copolymer. The polymer or copolymer and plasticizer may be applied to the foam in the form of an aqueous dispersion or emulsion or in a solution in an organic solvent. The impregnant may also contain mono-ammonium phosphate and/or dicyano-diamine and/or pentaerythritol to improve the non-inflammability of the foam, a high M.W. chloroparaffin of high chlorine content to prevent migration of the plasticizer and a lithium compound to make the mechanical properties of the resultant foam more independent of temperature. Preferred plasticizers are trichloroethyl phosphate, dibutyl phthalate and di(b -methoxyethyl)phthalate. A high M.W. wax may be added to the solution of impregnating agent. The impregnated foam plastic preferably contains 70 to 200% by weight of the impregnating agent.