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. 13, 1987
Filed:
Sep. 08, 1986
Applicant:
Inventors:
Takao Ikariya, Tokyo, JP;
Masanori Itagaki, Yokohama, JP;
Masatsugu Mizuguchi, Kawasaki, JP;
Itaru Sakai, Yokohama, JP;
Osamu Tajima, Kamakura, JP;
Assignee:
Nippon Kokan Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C / ; C07C / ;
U.S. Cl.
CPC ...
560025 ;
Abstract
According to a method of manufacturing a diphenylmethane dicarbamic acid ester by reacting an N-phenyl carbamic acid diester with a methylating agent in an aqueous acid solution, the aqueous acid solution is an aqueous inorganic acid solution, and the concentration of the N-phenyl carbamic acid ester in the aqueous acid solution is not more than the solubility thereof at the reaction temperature.