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:
Sep. 12, 2000
Filed:
Jan. 30, 1998
Honshu Chemical Industry Co., Ltd., Tokyo, JP;
Abstract
A batch or continuous process produces highly pure 3,3',5,5'-tetra-t-butylbiphenol suitable as a starting material for the synthesis of 4,4'-biphenol. The process for producing 3,3',5,5'-tetra-t-butylbiphenol comprises conducting an oxidation coupling of purified 2,6-di-t-butylphenol(i) or crude 2,6-di-t-butylbiphenol(ii), said crude 2,6-di-t-butylphenol being obtained by reacting isobutylene with phenol in the presence of an aluminum catalyst, and removing the aluminum catalyst. The 2,6-di-t-butylphenol is oxidatively coupled in an alkali metal catalyst mixture comprising (1) an alkali metal catalyst and alkylphenols, or (2) alkali metal catalyst, alkylphenols and phenol to produce 3,3',5,5'-tetra-t-butylbiphenol. The oxidative coupling is conducted together with 10-30% by weight of phenol and/or t-butylphenol per 100% by weight of 2,6-di-t-butylphenol in the presence of an alkali metal catalyst.