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. 02, 1990
Filed:
Sep. 21, 1988
Michio Tanaka, Iwakuni, JP;
Yoshito Kurano, Iwakuni, JP;
Katsuo Taniguchi, Iwakuni, JP;
Masayasu Ishibashi, Kuga, JP;
Mitsui Petrochemical Industries, Ltd., Tokyo, JP;
Abstract
A process is disclosed which is capable of producing p,p'-biphenol of high purity by the dealkylation reaction of 3,3',5,5'-tetra-t-butyl-4,4'-dihydroxybiphenyl and which yet allows isobutene to be recovered in high yield. The process performs the dealkylation reaction of 3,3',5,5'-tetra-t-butyl-4,4'-dihydroxybiphenyl in the presence of an acid catalyst using as a solvent a saturated hydrocarbon having a boiling point of 190.degree. C. or above, an alicyclic hydrocarbon having a boiling point of 190.degree. C. or above, a hydrocarbon with an iodine value of no more than 1, sulfolane, or a mixture of these solvents. Also disclosed is a process for producing p,p'-biphenol from a mixture of 2,6-di-t-butyl-phenol and 3,3',5,5'-tetra-t-butyl-4,4'-diphenoquinone or from a mixture of 2,6-di-t-butylphenol, 3,3',5,5'-tetra-t-butyl-4,4'-diphenoquinone and 3,3',5,5'-tetra-t-butyl-4,4'-dihydroxybiphenyl. In this process, the synthesis of 3,3',5,5'-tetra-t-butyl-4,4'-dihydroxybiphenyl by the redox reaction between 2,6-di-t-butylphenol and 3,3',5,5'-tetra-t-butyl-4,4'-diphenoquinone and the production of p,p'-biphenol by the dealkylation reaction of 3,3',5,5'-tetra-t-butyl-4,4'-dihydroxybiphenyl are performed at one stage in the presence of both an acid catalyst and a solvent at a temperature of 120.degree.-280.degree. C.