Masking films containing light shielding peelable layer utilizing nitrile resins

摘要

A masking film comprises a light-shielding peelable layer which is provided on a transparent support and comprises a polymer binder comprising a vinyl chloride resin, a rubberlike resin and a thermoplastic resin having OH groups and being compatible with the rubberlike resin and the vinyl chloride resin, wherein the polymer binder comprises a mixed nitrile rubber of a nitrile rubber having an acrylonitrile content of about 33% by weight and a Mooney viscosity of about 50 to 90 and another nitrile rubber either having an acrylonitrile content of about 28 to 32% by weight and a Mooney viscosity of about 35 to 70 or having an acrylonitrile content of about 33% by weight and a Mooney viscosity of about 35 to 50. The masking film simultaneously exhibits appropriate flexibility, good pick-up property, peelability and anti-blocking property of the light-shielding peelable layer and is stable against degradation of these properties with time.