| 摘要 |
PURPOSE: A manufacturing method of a polyvinyl alcohol-based polymer film is provided to provide an isotropic film which has a minimized phase difference in plane and in a thickness direction in a polyvinyl alcohol-based polymer film. CONSTITUTION: A polyvinyl alcohol-based polymer film comprises a phase difference reducer represented by chemical formula 1. In chemical formula 1, R1 is hydrogen or a C12-18 alkyl; each of R2-R4 is independently a C1-3 alkyl. A manufacturing method of the polyvinyl alcohol-based polymer film comprises a step of extruding raw material solution which consists of polyvinyl alcohol with a saponification degree of 99 mol% or more and a polymerization degree of 1,700 or more, a phase difference reducer, a plasticizer, a separator, and a solvent, through an extruder; supplying the extruded material onto a casting drum; and drying the extrude. |
