US4529823A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of bisphenol-A
Assignee: General Electric Co
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Filing: 1984-04-02
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Granted: 1985-07-16
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Expires: 2004-04-02
Abstract
Abstract This invention is directed to a method of purifying crude bisphenol-A by crystallization with agitation in phenolic water having less than 30 weight percent phenol. The crystals obtained have a morphology similar to that of aqueous crystallized bisphenol-A with a significantly higher degree of purity than crystals obtained from an aqueous crystallization. The use of an organic solvent, foreign to the bisphenol-A synthesis reaction, for either washing or crystallization can be avoided and only small quantities of phenol and water are required when providing pure bisphenol-A for polycarbonate synthesis by this process.
Inventors
- 👤 Ashok K. Mendiratta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:08
CPC Classifications
C; C07; C07C; C07C37/00; C07C37/68; C07C37/70; C07C37/84
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
101 words
A method of purifying crude bisphenol-A comprising (a) forming an admixture of crude bisphenol-A and phenolic water having less than 3 parts by weight phenolic water per part of crude bisphenol-A, said phenolic water having about 5-30 weight percent phenol, said admixture having a temperature sufficiently high to melt said crude bisphenol-A; (b) cooling said admixture to a temperature sufficiently low to crystallize bisphenol-A; (c) separating the bisphenol-A crystals and phenolic water; (d) contacting said bisphenol-A crystals with a washing solvent comprised of members selected from the group consisting of water, phenol and mixtures thereof; and (e) recovering said bisphenol-A crystals.
Claim 2
Independent Claim
101 words
A method of purifying crude bisphenol-A comprising (a) forming an admixture of crude bisphenol-A and phenolic water having less than 3 parts by weight phenolic water per part of crude bisphenol-A, said phenolic water having about 5-30 weight percent phenol, said admixture having a temperature sufficiently high to melt said crude bisphenol-A; (b) cooling said admixture to a temperature sufficiently low to crystallize bisphenol-A; (c) separating the bisphenol-A crystals and phenolic water; (d) contacting said bisphenol-A crystals with a washing solvent comprised of members selected from the group consisting of water, phenol and mixtures thereof; and (e) recovering said bisphenol-A crystals.
Claim 3
Dependent Claim
32 words
A method as in claim 1 wherein the washing solvent is an aqueous solution and less than 3 parts by weight of said aqueous solution per part of bisphenol-A crystals are utilized.
Claim 4
Dependent Claim
29 words
A method as in claim 1 wherein about 0.5 to 1.5 parts by weight of phenolic water per part of crude bisphenol-A are utilized to crystallize said crude bisphenol-A.
Claim 5
Dependent Claim
18 words
A method as in claim 1 wherein said phenolic water contains about 10 to 15 weight percent phenol.
Claim 6
Dependent Claim
34 words
A method as in claim 1 wherein said bisphenol-A crystals are contacted with a washing solvent comprised of about 0.5 to 1.5 parts by weight of an aqueous solution per part of bisphenol-A crystals.
Claim 7
Dependent Claim
18 words
A method as in claim 1 wherein said aqueous solution contains about 0 to 20 weight percent phenol.
Claim 8
Dependent Claim
18 words
A method as in claim 6 wherein said aqueous solution contains about 10 to 15 weight percent phenol.
Claim 9
Dependent Claim
23 words
A method as in claim 5 wherein said bisphenol-A crystals are contacted with an aqueous washing solvent containing about 10 weight percent phenol.
Claim 10
Dependent Claim
14 words
A method as in claim 1 wherein said crude bisphenol-A is crude 2,2-bis(4-hydroxy phenyl)propane.
Claim 11
Dependent Claim
29 words
A method as in claim 7 wherein the bisphenol-A crystals of step c are contacted with about 0 to 1 part by weight water per part of bisphenol-A crystals.
Claim 12
Independent Claim
97 words
A method of purifying bisphenol-A comprising (a) forming an admixture of crude 2,2 bis(4-hydroxy phenyl)propane with about 1 part by weight phenolic water having about 10 weight percent phenol, said admixture having a temperature sufficiently high to melt said crude 2,2bis(4-hydroxy phenyl)propane; (b) cooling said admixture to a temperature sufficiently low to crystallize 2,2 bis(4-hydroxy phenyl)propane; (c) separating the 2,2 bis(4-hydroxy phenyl)propane crystals and phenolic water; (d) contacting said 2,2 bis(4-hydroxy phenyl)propane crystals with about 1 part by weight of an aqueous washing solvent having about 10 weight percent phenol; and (e) recovering said 2,2 bis(4-hydroxy phenyl)propane.
Claim 13
Independent Claim
97 words
A method of purifying bisphenol-A comprising (a) forming an admixture of crude 2,2 bis(4-hydroxy phenyl)propane with about 1 part by weight phenolic water having about 10 weight percent phenol, said admixture having a temperature sufficiently high to melt said crude 2,2bis(4-hydroxy phenyl)propane; (b) cooling said admixture to a temperature sufficiently low to crystallize 2,2 bis(4-hydroxy phenyl)propane; (c) separating the 2,2 bis(4-hydroxy phenyl)propane crystals and phenolic water; (d) contacting said 2,2 bis(4-hydroxy phenyl)propane crystals with about 1 part by weight of an aqueous washing solvent having about 10 weight percent phenol; and (e) recovering said 2,2 bis(4-hydroxy phenyl)propane.
Claim 14
Dependent Claim
37 words
A method as in claim 11 comprising the addition step of contacting the 2,2 bis(4-hydroxy phenyl)propane crystals of step c with about 0 to 1 part by weight water per part of said 2,2 bis(4-hydroxy phenyl)propane crystals.
References Cited (Backward Citations)
US2791616A
Cited
US3192270A
Cited
US3326986A
Cited
FR1528935A
Cited
DE2548470A1
Cited
US4209646A
Cited
US4192955A
Cited
WO1980000150A1
Cited
JPS57159733A
Cited
US4467119A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-07-15 | 1989-01-14 | 1989-07-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-07-15 | 1993-01-14 | 1993-07-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-07-15 | 1997-01-14 | 1997-07-16 | $7700.00 | Window Closed / Lapsed |