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:
Jan. 31, 1989
Filed:
Jan. 20, 1988
Applicant:
Inventors:
Kazuyoshi Shigematsu, Sodegaura, JP;
Shigenori Shirouzu, Sodegaura, JP;
Assignee:
Idemitsu Kosan Co., Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C08G / ;
U.S. Cl.
CPC ...
528219 ; 528397 ;
Abstract
Polyformal resins having a repeating unit represented by the general formula: ##STR1## wherein the symbols are as defined in the appended claims and an intrinsic viscosity at 20.degree. C. as a methylene chloride solution of at least 0.2 dl/g, and a process for efficiently producing the polyformal resins. The present polyformal resins are excellent in heat resistance and optical properties, and thus are useful as materials for production of optical instruments, for example.