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.

Date of Patent:
Dec. 20, 1983

Filed:

Sep. 20, 1982
Applicant:
Inventor:

Chung J Lee, Sheboygan, WI (US);

Assignee:

Plastics Engineering Company, Sheboygan, WI (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C08G / ;
U.S. Cl.
CPC ...
528 56 ; 528 52 ; 528 53 ; 528 54 ; 528 55 ; 528 73 ; 528 84 ;
Abstract

The process described herein comprises the preparation of polyimides by the reaction of aromatic dianhydrides and aromatic diisocyanates in the presence of a metal acetylacetonate, such as Al, Co, Fe, Ni, Zr, etc. By using appropriate proportions, the polyimides may be end-capped with either anhydride or isocyanate groups. The use of the acetylacetonate permits the use of lower temperatures for imide ring closure thereby avoiding undesirable coreaction between anhydride groups and certain solvents. 'Polyimide dianhydride' is an anhydride-terminated polyimide; and 'polyimide diisocyanate' is an isocyanate-terminated polyimide as represented by the respective formulas: ##STR1## wherein Ar', Ar and n are as defined hereinafter. By this process, the polyimide dianhydride product has an anhydride activity of at least 0.17 as defined herein regardless of the type of solvent used.


Find Patent Forward Citations

Lee, Chung. (1983). Process for preparing polyimides end-capped with anhydride or isocyanate (U.S. Patent No. 4421905). U.S. Patent and Trademark Office. https://idiyas.com/patent/badge/4421905

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