POLYESTER FILM FOR COATING METAL SHEET, ITS MANUFACTURING METHOD AND METHOD FOR MANUFACTURING POLYESTER FILM-COATED METAL SHEET

摘要

PROBLEM TO BE SOLVED: To provide a polyester film which shows outstanding plate working properties (e.g. drawing/squeezing process) and best suitability for a metal can subjected to hot water sterilization, a method for manufacturing the same and a method for manufacturing a polyester film-coated metal sheet, with regard to the polyester film for coating the metal sheet, in the polyester film for coating a metal sheet, its manufacturing method and the method for manufacturing the polyester film-coated metal sheet. SOLUTION: The polyester film for coating the metal sheet is obtained by consolidating a molten resin film of polyester formed of a polyester composed mainly of an ethylene terephthalate and a polyester composed mainly of a butylene terephthalate in the mixing ratio of 60:40 to 30:70 wt% using a cooling roll with a surface roughness (Ra) of not less than 0.2 to less than 4.0μm and then stretching the consolidated resin film at least monoaxially in a longitudinal direction. In addition, the polyester film is characterized in that the surface roughness (Ra) is not more than 0.1μm. COPYRIGHT: (C)2004,JPO&NCIPI