Patent US4113974A successfully refreshed from Google Patents.
US4113974A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for purifying impure diphenols
Assignee: General Electric Co
•
Filing: 1976-12-30
•
Granted: 1978-09-12
•
Expires: 1996-12-30
Abstract
Abstract A process for improving the quality of diphenols by recrystallization from aqueous solvent systems.
Inventors
- 👤 Victor Mark
- 👤 Charles Vernon Hedges
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 01:22
CPC Classifications
C; C07; C07C; C07C37/00; C07C37/68; C07C37/70; C07C37/84
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
66 words
A process for purifying impure p,p' -diphenols which comprises dispersing the impure diphenol in water, heating the resulting slurry, adding a water soluble polar, aprotic co-solvent until the dissolution or near dissolution of the diphenol slurry results at or near the boiling point of water or the solvent system, cooling the solution to achieve the separation of the purified diphenol and recovering the purified p,p' -diphenol.
Claim 2
Dependent Claim
66 words
A process for purifying impure p,p' -diphenols which comprises dispersing the impure diphenol in water, heating the resulting slurry, adding a water soluble polar, aprotic co-solvent until the dissolution or near dissolution of the diphenol slurry results at or near the boiling point of water or the solvent system, cooling the solution to achieve the separation of the purified diphenol and recovering the purified p,p' -diphenol.
Claim 3
Dependent Claim
26 words
A process according to claim 1 wherein the polar, aprotic co-solvent is selected from the group consisting of amides, sulfoxides, sulfones, phosphoramides, sulfamides, nitriles and ethers.
Claim 4
Dependent Claim
21 words
A process according to claim 2 wherein the co-solvent is selected from the group consisting of dimethylformamide, dimethylsulfoxide, N-methylpyrrolidene and acetonitrile.
Claim 5
Dependent Claim
12 words
A process according to claim 1 wherein the impure diphenol is 2,2'-bis(4-hydroxyphenyl)propane.
Claim 6
Dependent Claim
26 words
A process according to claim 1 wherein the dissolution or near dissolution of the diphenol slurry results at about 90° to 100° C at atmospheric pressure.
Claim 7
Dependent Claim
22 words
A process according to claim 1 wherein the dissolution or near dissolution of the diphenol slurry is carried out at super-amtospheric pressure.
Claim 8
Dependent Claim
58 words
A process for purifying impure p,p' -diphenols which comprises dispersing the impure diphenol in a mixture of water and a water soluble polar, aprotic co-solvent or mixtures of co-solvents, heating the resultant slurry until the dissolution or near dissolution is achieved, cooling the solution to achieve the separation of the purified diphenol and recovering the purified p,p' -diphenol.
Claim 9
Dependent Claim
58 words
A process for purifying impure p,p' -diphenols which comprises dispersing the impure diphenol in a mixture of water and a water soluble polar, aprotic co-solvent or mixtures of co-solvents, heating the resultant slurry until the dissolution or near dissolution is achieved, cooling the solution to achieve the separation of the purified diphenol and recovering the purified p,p' -diphenol.
Claim 10
Dependent Claim
26 words
A process according to claim 7 wherein the polar, aprotic co-solvent is selected from the group consisting of amides, sulfoxides, sulfones, phosphoramides, sulfamides, nitriles and ethers.
Claim 11
Dependent Claim
21 words
A process according to claim 8 wherein the co-solvent is selected from the group consisting of dimethylformamide, dimethylsulfoxide, N-methylpyrrolidene and acetonitrile.
Claim 12
Dependent Claim
13 words
A process according to claim 7 wherein the impure diphenol is crude 2,2'-bis(4-hydroxyphenyl)propane.
Claim 13
Dependent Claim
26 words
A process according to claim 7 wherein the dissolution or near dissolution of the diphenol slurry results at about 90° to 100° C at atmospheric pressure.
Claim 14
Dependent Claim
22 words
A process according to claim 7 wherein the dissolution or near dissolution of the diphenol slurry is carried out at super-atmospheric pressure.
References Cited (Backward Citations)
US2959622A
Cited
US2829175A
Cited
US2845464A
Cited
US3073868A
Cited
US3535389A
Cited
US3207795A
Cited
US3290391A
Cited
US3326986A
Cited
US3932535A
Cited
US3673262A
Cited
US3919330A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-09-11 | 1982-03-13 | 1982-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-09-11 | 1986-03-13 | 1986-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-09-11 | 1990-03-13 | 1990-09-12 | $7700.00 | Window Closed / Lapsed |