US4156098A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of bisphenol-A
Assignee: General Electric Co
•
Filing: 1978-05-30
•
Granted: 1979-05-22
•
Expires: 1998-05-30
Abstract
Abstract Impure bisphenol-A can be purified by treatment of a phenol adduct of the latter with methylene chloride and then recovering the purified bisphenol-A.
Inventors
- 👤 Ming K. Li
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:06
CPC Classifications
C; C07; C07C; C07C37/00; C07C37/68; C07C37/86
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
84 words
The method of recovering 2,2-bis(4-hydroxyphenyl) propane in a purified state from a mixture of the latter and impurities derived from the acid catalyzed condensation of phenol and acetone, which comprises (1) combining an adduct of phenol and the above-identified impure dihydroxy-diphenyl propane with methylene chloride to effect intimate admixture of the adduct and the methylene chloride, (2) allowing the dihydroxy-diphenyl propane to precipitate from the methylene chloride component, and (3) separating the precipitated dihydroxy-diphenyl propane in the form of a highly purified crystalline product.
Claim 2
Independent Claim
84 words
The method of recovering 2,2-bis(4-hydroxyphenyl) propane in a purified state from a mixture of the latter and impurities derived from the acid catalyzed condensation of phenol and acetone, which comprises (1) combining an adduct of phenol and the above-identified impure dihydroxy-diphenyl propane with methylene chloride to effect intimate admixture of the adduct and the methylene chloride, (2) allowing the dihydroxy-diphenyl propane to precipitate from the methylene chloride component, and (3) separating the precipitated dihydroxy-diphenyl propane in the form of a highly purified crystalline product.
Claim 3
Dependent Claim
27 words
The process as in claim 1 wherein the admixture of the adduct and the methylene chloride is carried out with stirring at a temperature below 60° C.
Claim 4
Dependent Claim
43 words
The process as in claim 1 wherein the mother liquor obtained as a result of removing the precipitated dihydroxy-diphenyl propane is further treated with methylene chloride and the mixture subjected to reduced temperatures to effect precipitation of additional amounts of the dihydroxy-diphenyl propane.
Claim 5
Dependent Claim
22 words
The process as in claim 1 wherein the precipitated dihydroxy-diphenyl propane is washed with methylene chloride to provide still higher purity product.
Claim 6
Dependent Claim
29 words
The process as in claim 1 wherein the filtration step required to obtain the precipitated dihydroxy-diphenyl propane is carried out at a temperature of from 30° to 40° C.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-05-21 | 1982-11-20 | 1983-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-05-21 | 1986-11-20 | 1987-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-05-21 | 1990-11-20 | 1991-05-22 | $7700.00 | Window Closed / Lapsed |