METHOD FOR MANUFACTURING RETARDATION PLATE

摘要

PROBLEM TO BE SOLVED: To provide a retardation plate capable of enhancing flexibility of a bonding angle when a circular polarizing lens for right and left eye 3D passive glasses is formed by laminating a polarizing plate and a retardation plate and applied to polarizing glasses extremely excellent in visibility when a 3D video is observed.SOLUTION: The method for manufacturing a retardation plate consisting of a biaxially oriented vinyl alcohol based film includes heat-treating the biaxially oriented vinyl alcohol based film in at least two stages. The heating temperature of the first stage is 130-180°C, and the heating temperature of the second stage is 160-210°C. The heating temperature of the second stage is higher by 5°C or more than the heating temperature of the first stage.