FLEXIBLE THERMOPLASTIC COMPOSITIONS

摘要

1372185 Laminates COAL INDUSTRY (PATENTS) Ltd 8 Sept 1971 [11 Sept 1970 4 June 1971] 43589/70 and 19032/71 Heading B5N [Also in Division C3] A flexible roofing sheet to be bonded with bitumen comprises a thermoplastic polymer, preferably PVC, in an amount of at least 20% by wt. of the composition, a migratory plasticizer, in an amount of 5-15%, provided that the ratio of polymer to plasticizer is less than 4 : 1 and the amount of plasticizer is lower than that which will cause injurious degradation of bitumen used to bond the sheet to a substrate. Preferably a rubber is also present, particularly nitrile rubber, in an amount of 3-40%. Other ingredients may be coal tar pitch, non- migratory plasticizers, fibrous and particulate fillers and stabilizers, lubricants and antioxidants. The bitumen adhesive may be blown and oxidized. Reference has been directed by the Comptroller to Specification 1,296,377.