US4408087A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of bisphenol-A
Assignee: General Electric Co
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Filing: 1979-10-29
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Granted: 1983-10-04
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Expires: 1999-10-29
Abstract
Abstract Pure bisphenol-A can be obtained by treating the adduct of the latter and phenol with water in two stages.
Inventors
- 👤 Ming K. Li
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:49
CPC Classifications
C; C07; C07C; C07C37/00; C07C37/68; C07C37/70; C07C37/72; C07C37/685
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
159 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 condensation of phenol and acetone which comprises: (1) combining a mixture of (a) an adduct of phenol and said 2,2-bis(4-hydroxyphenyl)propane and (b) impurities associated with (a), with from 1 to 4 parts, by weight, water per weight part of adduct, (2) heating the mixture of the adduct and water at a temperature from 85° to 110° C., to break said adduct and form a two-phase liquid aqueous-organic system, (3) separating the organic phase containing said 2,2-bis(4-hydroxyphenyl)propane from the aqueous phase formed in (2) while the two phases are at an elevated temperature, (4) adding the organic phase an amount of water less than that used in step (1), wherein the water and organic phase mixture is at a temperature of at least 85° C., and (5) cooling the mixture to precipitate said 2,2-bis(4-hydroxyphenyl)propane in a highly purified state.
Claim 2
Independent Claim
159 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 condensation of phenol and acetone which comprises: (1) combining a mixture of (a) an adduct of phenol and said 2,2-bis(4-hydroxyphenyl)propane and (b) impurities associated with (a), with from 1 to 4 parts, by weight, water per weight part of adduct, (2) heating the mixture of the adduct and water at a temperature from 85° to 110° C., to break said adduct and form a two-phase liquid aqueous-organic system, (3) separating the organic phase containing said 2,2-bis(4-hydroxyphenyl)propane from the aqueous phase formed in (2) while the two phases are at an elevated temperature, (4) adding the organic phase an amount of water less than that used in step (1), wherein the water and organic phase mixture is at a temperature of at least 85° C., and (5) cooling the mixture to precipitate said 2,2-bis(4-hydroxyphenyl)propane in a highly purified state.
Claim 3
Dependent Claim
15 words
The method as in claim 1 wherein the precipitated 2,2-bis(4-hydroxyphenyl)propane is treated with methylene chloride.
Claim 4
Dependent Claim
25 words
The method as in claim 1 wherein the water used in step (4) is equal, by weight, to 0.5 to 2 parts per part 2,2-bis(4-hydroxyphenyl)propane.
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) | 1986-10-03 | 1987-04-04 | 1987-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-03 | 1991-04-04 | 1991-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-03 | 1995-04-04 | 1995-10-04 | $7700.00 | Window Closed / Lapsed |