POLYESTER BASED FILM FOR MAGNETIC RECORDING MEDIUM

摘要

PURPOSE:To obtain the title film having excellent smoothness, adhesive property and blocking resistance by applying a specific sulfonic acid metal salt-containing polyester to the surface of a substrate film consisting of a polyester-based resin. CONSTITUTION:The objective film obtained by applying a sulfonic acid metal salt-containing polyester having a sulfonic acid metal salt such as 5-sodium sulfoisophthalate in one molecule, being a water-dispersible and water-insoluble sulfonic acid metal salt-containing polyester (preferably having 0.5-10mol% copolymer amount basal on total carboxylic acid) and having <=10 coarse projection number based on 100cm<2> area when formed into a film to at least one side of a substrate film consisting of a polyester-based resin such as polyethylene terephthalate.