Polarizing film, optical film laminate including polarizing film, and method for manufacturing the same

摘要

[Objects] To provide a polarizing film, and an optically film laminate including the polarizing film. [Means for accomplishing the Objects] An optical film laminate comprising:
a substrate comprising a crystallizable ester type thermoplastic resin in the form of a continuous web; and
a polarizing film comprising a polyvinyl alcohol type resin layer formed on the substrate, said polarizing film including a dichroic material impregnated therein in a molecularly oriented state,
wherein the polarizing film is formed by providing a laminate comprising the polyvinyl alcohol type resin layer formed on a substrate comprising a crystallizable ester type thermoplastic resin in an amorphous state and subjecting the laminate to a 2-stage stretching process comprising a preliminary in-air stretching and an in-boric-acid-solution stretching under a temperature maintaining the amorphous state of the substrate, such that the polyvinyl alcohol type resin layer is stretched to a thickness of 10µm or less, the polarizing film having optical properties which satisfy conditions represented by the formulae:
P > -(10 0.929T-42.4 - 1) × 100 (where T<42.3); and
P‰¥99.9 (where T‰¥42.3)
where: T represents a single layer transmittance and P a polarization rate, is disclosed.