Bi-axially oriented film of specific thickness with improved mechanical hardening and shrinkage properties

摘要

A biaxially oriented film of thickness = 10 mu and having a specific mechanical hardening coefficient. Biaxially oriented film of thickness = 10 mu , has a mechanical hardening coefficient (MV): where MV ( deg C.mm2.N-1) = (S200TD(T2%-100)(S200MD-3.35) x 1000)/(ETD-3000) = ?- 2-50; S200TD = widthwise shrinkage after 15 min.(%); S200MD = lengthwise shrinkage after 15 min.(%); T2% = temperature ( deg C) at which a constant tension of 5 N/mm2 and 2% is achieved; ETD = E-modulus in cross-section (N/mm2) An independent claim is also included for production of the film by stretching sequentially in the length and width directions, then thermofixing, whereby the relaxation speed is = 20% and the maximum temperature - 210 deg C.