PRODUCTION OF PHASE DIFFERENCE PLATE

摘要

PROBLEM TO BE SOLVED: To equalize the phase difference of a phase difference plate produced by an extrusion deposition method. SOLUTION: A film which is formed by kneading a thermoplastic resin and a volatile plasticizer and is discharged from a die is heated by a far IR heater 1 until the film comes into contact with a metallic roll 3 so as to attain the (b. p. -50) deg.C to b. p. of the plasticizer and is heated by a hot air blow-off device 2 up to the point where the peelability of the film does not degrade after the contact with the metallic roll 3. The film is then nip-cooled with the metallic roll 3 from the end point of the heating to the peeling point of the film and is subjected to longitudinal uniaxial stretching by a roll stretching machine 5.