Title:
【発明の名称】平滑の押出プレーンシートまたはフイルムを製造する方法および装置、この種の押出品および光学的記憶体を製造する方法
Document Type and Number:
Japanese Patent JP2951042
Kind Code:
B2
Abstract:
Extruded solid plates or sheets, if appropriate also of a thickness less than 1 mm, of a thermoplastic material having a glass transition temperature above 50 DEG C, which upon orientation produces optical birefringence, such as polycarbonate, can be manufactured with a path difference of the optical birefringence not exceeding 50 nm (single pass), low surface roughness and low thickness variation by extrusion of the plastic material in the thermoplastic state from a slot die to form a flat web and glazing of the surfaces of the web if, during or after the glazing of both surfaces, the one surface of the web is cooled below the glass transition temperature whereas the other surface and the predominant part of the interior of the web remain in the thermoplastic state, and the web is cooled below the glass transition temperature under conditions in which the deforming forces acting on the surfaces of the strand are minimised.
Inventors:
KAARU FUNKU
HAINTSU GUROOSU
HAINTSU GUROOSU
Application Number:
JP13605391A
Publication Date:
September 20, 1999
Filing Date:
June 07, 1991
Export Citation:
Assignee:
REEMU GMBH
International Classes:
B29C48/07; B29C48/90; B29C59/00; B29C59/04; B29D7/01; B29D11/00; B29C48/08; B29K69/00; B29L7/00; (IPC1-7): B29C47/88; B29C47/90
Domestic Patent References:
| JP3114723A | ||||
| JP4232016A | ||||
| JP6364718A |
Other References:
【文献】英国特許出願公開2051663(GB,A)
Attorney, Agent or Firm:
Toshio Yano (2 outside)