Biaxially stretched polyester film containing carbon black as black pigment and process for its production

摘要

Black, two-layered biaxially stretched polyester film comprises: less than 1-2.42 wt.% carbon black, where the polyester film has a thickness of 10-50 mm, a transparency of less than 8% in which none of the layers contain more than 10 wt.% carbon black; and at least one outer layer which contains less than 0.5 wt.% carbon black. The outer layer has a gloss of at least 70 at 60[deg] , and thickness of at least 0.4-7 mm, and benzo(a)pyrene content of less than 5 ppb. The carbon black used has a total content of polycyclic aromatic hydrocarbons of less than 0.5 ppm. Black, two-layered biaxially stretched polyester film comprises: less than 1-2.42 wt.% carbon black, where the polyester film has a thickness of 10-50 mm, a transparency of less than 8% in which none of the layers contain more than 10 wt.% carbon black; and at least one outer layer which contains less than 0.5 wt.% carbon black. The outer layer has a gloss of at least 70 at 60[deg] , and thickness of at least 0.4-7 mm, and benzo(a)pyrene content of less than 5 ppb. The carbon black used has a total content of polycyclic aromatic hydrocarbons of less than 0.5 ppm and has a Brunauer, Emmett and Teller (BET) surface area of more than 40-less than 500 m 2>/g and of an oil-adsorption number of more than 40- less than 200 (measured with dibutyl phthalate (ml/100 g)).