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:
Dec. 22, 1981
Filed:
Dec. 01, 1980
Applicant:
Inventors:
Assignee:
Mitsui Toatsu Chemicals, Incorporated, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
2604 / ; 560 25 ;
Abstract
A process for preparing polymethylene polyphenyl polyisocyanates, in which N-phenyl carbamic acid esters are subjected to a condensation reaction with formaldehyde, and the reaction product containing polymethylene polyphenyl polycarbamic acid esters and unreacted N-phenyl carbamic acid esters is thermally decomposed to obtain polymethylene polyphenyl polyisocyanates.