The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 11, 1994
Filed:
Apr. 27, 1993
Applicant:
Inventors:
Kazuyuki Yamasaki, Tokyo, JP;
Takehiko Kitamura, Chiba, JP;
Assignees:
Mitsui Petrochemical Industries, Ltd., Tokyo, JP;
Sumitomo Heavy Industries, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B29C / ;
U.S. Cl.
CPC ...
264-11 ; 26432816 ;
Abstract
A process for the preparation of substrate for optical disk characterized in that pellets of 4-methyl-1-pentene polymer or copolymer having a melt flow rate (MFR), as measured according to ASTM D1238 under a load of 5 kg and at a temperature of 260.degree. C., of 240-1200 g/10 min, and a melting point as measured by means of DSC of 234.degree.-240.degree. C., are injection molded into the substrate under the conditions where a temperature of at least part of a cylinder is 320.degree.-370.degree. C. and a mold temperature is not more than 55.degree. C.