Title:
PRODUCTION METHOD OF OPTICAL FILM
Document Type and Number:
Japanese Patent JP2014223758
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To improve irregular film thickness in a process of forming a film by flow-casting a dope onto a belt between two drums, by suppressing vibration of the belt near a rear wall of a pressure reduction chamber even when film forming speed is increased, so as to suppress irregular intensity of an entrained wind and to suppress vibration of a flow-cast ribbon by the entrained wind.SOLUTION: A dope is cast from a flow-cast die 3 onto a belt 6 between two drums 5, 7. A pressure reduction chamber 4 is disposed on an upstream side along the moving direction of the belt 6 with respect to the flow-cast die 3 so as to give a 0.3 to 3 mm gap between the belt 6 and the chamber; and at least one support roll 11 is disposed to support the belt 6 from an inner circumference surface side. When a direction from the center position of a rear wall 4a of the pressure reduction chamber 4 toward the downstream side is defined as a positive direction while a direction toward the upstream side is defined as a negative direction, the first support roll 11a is positioned in such a manner that the center of the contact range between the support roll and the belt 6 along the moving direction of the belt 6 is present in a range from +100 mm to -300 mm with reference to the center position of the rear wall 4a.
Inventors:
FURUYAMA TOMOMASA
Application Number:
JP2013104339A
Publication Date:
December 04, 2014
Filing Date:
May 16, 2013
Export Citation:
Assignee:
KONICA MINOLTA INC
International Classes:
B29C41/34; B29C41/28; G02B5/30
Attorney, Agent or Firm:
Shizuo Sano
Atsushi Inoue
Yasushi Inoue
Atsushi Inoue
Yasushi Inoue