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:
Jun. 28, 1983
Filed:
Oct. 19, 1981
James A Manner, Akron, OH (US);
PPG Industries, Inc., Pittsburgh, PA (US);
Abstract
Aromatic esters of carbamic acid derivatives, e.g., p-chlorophenyl-N-methyl carbamate, are prepared by reaction of the corresponding aromatic alcohol, e.g., p-chlorophenol, and monoisocyanate, e.g., methyl isocyanate, in the presence of a catalytic amount of a combination of a 4-aminopyridine catalyst, e.g., 4-dimethylaminopyridine, and pyridine or methyl substituted pyridines. The product is substantially pure, having less than 0.80 weight percent allophanate ester by-product, e.g., p-chlorophenyl-N,N'-dimethyl allophanate, and less than 0.50 weight percent unreacted aromatic alcohol, e.g., p-chlorophenol. The reaction is readily controlled and characterized by the substantial absence of reflux. The product can be retained in the liquid state at reaction temperature for extended periods of time without significantly increasing the level of allophanate ester by-product.