Patent number: 4891453
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.
Type:
Grant
Filed:
September 21, 1988
Date of Patent:
January 2, 1990
Assignee:
Mitsui Petrochemical Industries, Ltd.
Inventors:
Michio Tanaka, Yoshito Kurano, Katsuo Taniguchi, Masayasu Ishibashi