PRODUCTION OF POLYSULFONE PHASE DIFFERENCE FILM

摘要

PROBLEM TO BE SOLVED: To provide a process for producing a polysulfone phase difference film which has the excellent uniformity of a thickness and optical characteristic and is suitable for applications, such as liquid crystal display elements. SOLUTION: Methylene chloride is used as an essential component of an org. solvent and anisole of 1 to 5 wt.% in terms of solid content is added thereto in the process for producing the phase difference film which is stretched after the solvent content in the raw film formed by a casting method using an org. solvent soln. of a polysulfone polymer is regulated to 1 to 5 wt.% in terms of solid content.