BIAXIALLY ORIENTED POLYESTER FILM

摘要

PURPOSE:To obtain a biaxially oriented film which is smooth and highly excellent in abrasion resistance and slidability by adding an aggregated aluminum oxide having a specified primary particle diameter and a specified secondary particle diameter to a biaxially oriented polyester film. CONSTITUTION:A biaxially oriented polyester film containing 0.01-2wt.% aggregated aluminum oxide having a primary particle diameter of 0.1mum or below and a secondary particle diameter of 0.1-3mum. Desirably, the film wherein the aggregated aluminum oxide comprises at least 80wt.% aggregated aluminum oxide having a gamma-crystal structure. More desirably, the film wherein the aggregated aluminum oxide is treated with 0.1-5wt.%, based on the aggregated aluminum oxide, compound of the formula and/or copolymer thereof and/or their mixture. In the formula, X is H or 1-3C alkyl; Y is a carboxylic acid and/or its salt or ester; and n is selected so that the mol.wt. may fall in the range of 2000-100000.