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:
Jan. 06, 1981
Filed:
Aug. 31, 1979
Walter R Demler, Hamburg, NY (US);
Krishen L Nagpal, Williamsville, NY (US);
Richard M Dollard, W. Seneca, NY (US);
Eugene Odin, Williamsville, NY (US);
Donald T Donahue, Kenmore, NY (US);
Buffalo Color Corporation, West Paterson, NJ (US);
Abstract
A process for the preparation of 4,4' dihydroxydiphenyl by acidifying an alkali metal salt of 4,4' dihydroxydiphenyl. The alkali metal salt of 4,4' dihydroxydiphenyl is prepared by fusion of an alkali metal hydroxide with alkali metal diphenyl 4,4' disulfonic acid. Because the reaction may be carried out in granular form, or in a reaction which is made highly fluid by using potassium hydroxide with potassium diphenyl 4,4' disulfonic acid, or by reacting the alkali metal 4,4' disulfonic acid in increments with the hydroxide, low molar ratios of hydroxide to alkali metal diphenyl 4'4, disulfonic acid may be used. When potassium diphenyl 4,4' disulfonic acid is used in accordance with the invention, it is prepared by reacting 4,4' diphenyl disulfonic acid with an inorganic neutral potassium salt.