公开(公告)号：US3321435A

公开(公告)日：1967-05-23

申请号：US35011763

申请日：1963-03-09

Applicant: BAYER AG

Inventor： GERHARD FRITZ ,  LUDWIG BOTTENBRUCH ,  HERMANN SCHNELL ,  WERNER GOLLER

IPC: C08K3/00 ,  C08K3/32 ,  C08K3/38 ,  C08K5/55

CPC classification number: C08K3/38 ,  C08K3/014 ,  C08K3/32 ,  C08K5/55 ,  C08L69/00

Abstract: Polycarbonates containing small quantities of moisture are stabilized against degradation whilst molten by adding to the polycarbonates, before melting, from 0.001 to 2% of an inorganic acid of pentavalent phosphorus or an anhydride, ester or partial ester thereof, an inorganic acid of boron or an anhydride, ester or partial ester thereof, or boron phosphate. The stabilizers may be added to a solution obtained by reacting a dihydroxy compound with phosgene or a bis-chlorocarbonate, or to the product obtained by transesterification of a dihydroxy compound with a carbonate ester. They may be added dissolved in an organic solvent or as a concentratde solution in a polycarbonate. Examples describe the stabilization of the polycarbonate of bisphenol A.