Method for separation and recovering hydroquinone
US4049723A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 17, 1975 |
| Grant date | Sep 20, 1977 |
| Priority date | — |
| Expiry date | Sep 17, 1995 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C37/74
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A method for separating and recovering hydroquinone which comprises distilling a by-product-containing acid-cleavage product, which is obtained by acid-cleavage of an oxidation product of para-diisopropyl benzene in a solvent, in the presence of an aromatic hydrocarbon, thereby removing low-boiling fractions including the solvent, bringing the resulting hydroquinone-containing distillation bottoms into contact with water, and crystallizing and separating hydroquinone; characterized in that A. the distilling off of the low-boiling fractions is effected without the addition of water and in the absence of an azeotropic amount of water and also in the presence of an aromatic hydrocarbon containing 9 to 10 carbon atoms, and B. the contacting of the distillation bottoms with water is effected under conditions which do not induce crystallization of hydroquinone in the distillation bottoms.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.