Process for recovering 2,2-bis(4-hydroxyphenyl)propane from an adduct of 2,2-bis(4-hydroxyphenyl)propane and phenol
US4212997A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 27, 1978 |
| Grant date | Jul 15, 1980 |
| Priority date | — |
| Expiry date | Jun 27, 1998 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C37/685
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The compound 2,2-bis(4-hydroxyphenyl)propane is recovered in the form of rhombic crystals from an essentially non-crystalline mixture comprising 2,2-bis(4-hydroxyphenyl)propane, organic by-products of the condensation reaction of phenol and acetone, and phenol by lowering the temperature of the mixture from an elevated state to a temperature which is low enough to cause the separation of the phenol and 2,2-bis(4-hydroxyphenyl)propane in equimolar proportions as a crystalline adduct, recovering the adduct, forming a mixture of the adduct and water at an elevated temperature sufficient to completely melt the adduct, and thereafter lowering the temperature of the mixture of water and melted adduct to cause the separation of the 2,2-bis(4-hydroxyphenyl)propane in the form of rhombic crystals substantially free of the phenol. The crystals are easily handled and recovered by means such as filtration or centrifugation, and they can be formed into high quality polycarbonate molding resins.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.