BIAXIALLY ORIENTED COPOLYESTER FILM FOR MAGNETIC RECORDING DISKS AND MAGNETIC RECORDING DISKS MADE THEREFROM.

摘要

Disclosed herein is a biaxially oriented PENBB film for magnetic recording disks having low water absorption, low shrinkage and high modulus. The film typically is 60-100 microns thick. One surface of the film preferably is very smooth. PENBB as mentioned herein is a copolyester containing units of formula (I).