FLAME-RETARDANT CLEAR POLYESTER FILM AND ITS PRODUCTION METHOD

摘要

PROBLEM TO BE SOLVED: To prepare a flame-retardant clear polyester film which has a thickness of 5-300μm, is excellent in optical and mechanical properties and in stretchability, is low in cost, and does not become brittle even at high temperatures. SOLUTION: This polyester film contains at least one flame retardant which is soluble in a polyester. The flame retardant is directly compounded by using a masterbatch in the film production step. The masterbatch is supplied under agitation under a reduced pressure while the temperature is being raised slowly.