PLASTICIZER-CONTAINING FILMS OF PARTIALLY ACETALIZED POLYVINYL ALCOHOLS

摘要

The present invention is concerned with a composite safety glass product which comprises a sheet of a transparent silicate glass adhesively bonded to a sheet of material comprising a transparent silicate glass or a transparent synthetic resin, said sheets being bonded by a film of a partially butyralized polyvinyl alcohol resin having a hydroxyl group content of 5 to 30% by weight, calculated as polyvinyl alcohol, and containing as plasticizer a mixture of 99% to 1% of an ester of an organic cyclic acid whose alkyl part has more than 6 C-atom and/or a conventional butyral plasticizer for said resins; and 1% to 99% of an ester of an oxygen acid of phosphorous whose alkyl part has more than 6 C-atom; said plasticizer mixture being present in the film in an amount of 20 to 85% by weight, relative to the total weight of the film.