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:
Apr. 19, 1994
Filed:
Feb. 25, 1993
Katsuji Shibata, Shimotsuma, JP;
Kazuhito Kobayashi, Yuki, JP;
Nozomu Takano, Shimodate, JP;
Masami Arai, Shimodate, JP;
Ikuo Hoshi, Shimodate, JP;
Hitachi Chemical Co., Ltd., Tokyo, JP;
Abstract
An epoxy resin film which is so strong as to have a tensile strength of not less than 10 MPa and an elongation of not less than 5% is formed by using a substantially linear high molecular weight epoxy resin which is synthesized by polymerizing a difunctional epoxy resin having two epoxy groups per molecule and a dihydric phenol in an aprotic polar solvent, in the presence of a solvent, at a reaction temperature ranging from 80.degree. to 130.degree. C., the difunctional epoxy resin and the dihydric phenol being used in quantities which provide a ratio of phenolic hydroxyl groups to epoxy groups of from 1:0.9 to 1:1.1 and a proportion of the total of them of at most 50% by weight based on the total of them and the aprotic polar solvent.