Title:
POLYIMIDE FILM AND PROCESS FOR PRODUCING THE SAME
Document Type and Number:
WIPO Patent Application WO/2004/063252
Kind Code:
A1
Abstract:
A polyimide film having biaxial optical anisotropy and excellent durability. A solution of a polyimide having a degree of imidization of 98 to 100% is applied to a plastic substrate and dried to form a polyimide film. The polyimide film is stretched together with the plastic substrate so that the film comes to satisfy the relationship nx>ny>nz (wherein nx and ny are the refractive indexes respectively in the direction in which the refractive index is highest in the plane and in the in-plane direction perpendicular to that direction; and nz is the refractive index in the thickness direction). The polyimide preferably is a fluorinated polyimide because it is excellent in light transmittance and solubility. It preferably has a weight-average molecular weight of 50,000 to 180,000. The solvent in the polyimide solution preferably has a solubility parameter of 17 to 22 as measured under the conditions of atmospheric pressure, i.e., 1 atm, and an ambient temperature of 25°C.
Inventors:
Sakamoto, Michie c/o NITTO DENKO CORPORATION (1-2 Shimohozumi 1-chom, Ibaraki-shi Osaka, 567-8680, JP)
Nishikouji, Yuuichi c/o NITTO DENKO CORPORATION (1-2 Shimohozumi 1-chom, Ibaraki-shi Osaka, 567-8680, JP)
Murakami, Nao c/o NITTO DENKO CORPORATION (1-2 Shimohozumi 1-chom, Ibaraki-shi Osaka, 567-8680, JP)
Hayashi, Masaki c/o NITTO DENKO CORPORATION (1-2 Shimohozumi 1-chom, Ibaraki-shi Osaka, 567-8680, JP)
Nishikouji, Yuuichi c/o NITTO DENKO CORPORATION (1-2 Shimohozumi 1-chom, Ibaraki-shi Osaka, 567-8680, JP)
Murakami, Nao c/o NITTO DENKO CORPORATION (1-2 Shimohozumi 1-chom, Ibaraki-shi Osaka, 567-8680, JP)
Hayashi, Masaki c/o NITTO DENKO CORPORATION (1-2 Shimohozumi 1-chom, Ibaraki-shi Osaka, 567-8680, JP)
Application Number:
PCT/JP2003/016643
Publication Date:
July 29, 2004
Filing Date:
December 24, 2003
Export Citation:
Assignee:
NITTO DENKO CORPORATION (1-2 Shimohozumi 1-chome, Ibaraki-shi, Osaka, 567-8680, JP)
Sakamoto, Michie c/o NITTO DENKO CORPORATION (1-2 Shimohozumi 1-chom, Ibaraki-shi Osaka, 567-8680, JP)
Nishikouji, Yuuichi c/o NITTO DENKO CORPORATION (1-2 Shimohozumi 1-chom, Ibaraki-shi Osaka, 567-8680, JP)
Murakami, Nao c/o NITTO DENKO CORPORATION (1-2 Shimohozumi 1-chom, Ibaraki-shi Osaka, 567-8680, JP)
Hayashi, Masaki c/o NITTO DENKO CORPORATION (1-2 Shimohozumi 1-chom, Ibaraki-shi Osaka, 567-8680, JP)
Sakamoto, Michie c/o NITTO DENKO CORPORATION (1-2 Shimohozumi 1-chom, Ibaraki-shi Osaka, 567-8680, JP)
Nishikouji, Yuuichi c/o NITTO DENKO CORPORATION (1-2 Shimohozumi 1-chom, Ibaraki-shi Osaka, 567-8680, JP)
Murakami, Nao c/o NITTO DENKO CORPORATION (1-2 Shimohozumi 1-chom, Ibaraki-shi Osaka, 567-8680, JP)
Hayashi, Masaki c/o NITTO DENKO CORPORATION (1-2 Shimohozumi 1-chom, Ibaraki-shi Osaka, 567-8680, JP)
International Classes:
B29C41/28; B29C55/04; C08J7/04; G02F1/13363; (IPC1-7): C08J5/18; B29C41/12; B32B27/34; C08G73/10; G02B5/30; G02F1/1335
Attorney, Agent or Firm:
IKEUCHI SATO & PARTNER PATENT ATTORNEYS (26th Floor, OAP TOWER 8-30, Tenmabashi 1-chome, Kita-k, Osaka-shi Osaka, 530-6026, JP)