MANUFACTURING METHOD FOR OPTICAL FILM

• Main Authors: JIYUNI YASUTO, OKADA YASUMASA
• Format: Patent
• Language: English
• Published: 10.06.2004
• Edition: 7
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULARARTICLES; PERFORMING OPERATIONS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

PROBLEM TO BE SOLVED: To provide a manufacturing method for an optical film of which the residual phase difference brought about by an extrusion method and the flare are small. SOLUTION: The optical film is manufactured by a method wherein a thermoplastic resin film melted and extruded like a sheet is brought into close contact with and cooled by a metallic cooling roll having a glass transition temperature of +20 to -50°C, while an electric charge is given only to the vicinity of the end part of the film at a point where the film comes into contact with the roll, so as to conduct edge pinning, and the film is pulled upward almost vertically to be peeled from the cooling roll, by a rubber roll provided above the cooling roll and having the rotational torque controlled. The tension of this optical film is 98 N or below per 1 m width thereof and the temperature thereof just before the contact with the rubber roll is a room temperature to the room temperature + 50°C. The wrap angle of the thermoplastic resin film to the rubber roll is made 90-240 degrees. COPYRIGHT: (C)2004,JPO