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US4058663A
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Stabilization with alkali metal compound material of certain thermally unstable DMT
Assignee: CAPE INDUSTRIES A JOINT VENTURE CONSISTING OF NCT Corp AND AMERICAN PETROFINA Inc
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Filing: 1976-03-02
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Granted: 1977-11-15
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Expires: 1996-03-02
Abstract
Abstract Disclosed is the stabilization of thermally unstable, fresh dimethyl terephthalate of at least 99.8 weight % purity, free of alkali metal compound material, and produced by the cooxidation-esterification process. Stabilization is effected by incorporating therein a stabilizing quantity of alkali metal compound material having no significant concentration of either phosphonic acid moiety or phosphite moiety.
Inventors
- 👤 Donald Kirkbright Black
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:53
CPC Classifications
C; C07; C07C; C07C67/00; C07C67/48; C07C67/62
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
53 words
A thermally stable composition consisting essentially of (1) thermally unstable fresh dimethyl terephthalate of extremely high purity, free of alkali metal compound material, having no significant concentration of either phosphonic acid moiety or phosphite moity, and produced by the cooxidationesterification process, and (2) dispersed therein at a stabilizing concentration, alkali metal monomethyl terehthalate.
Claim 2
Dependent Claim
53 words
A thermally stable composition consisting essentially of (1) thermally unstable fresh dimethyl terephthalate of extremely high purity, free of alkali metal compound material, having no significant concentration of either phosphonic acid moiety or phosphite moity, and produced by the cooxidationesterification process, and (2) dispersed therein at a stabilizing concentration, alkali metal monomethyl terehthalate.
Claim 3
Dependent Claim
39 words
A thermally stable composition according to claim 1 in which the concentration of said alkali metal monomethyl terephthalate is in the range from about 0.5 to about 500 parts by weight per million parts by weight of said DMT.
Claim 4
Dependent Claim
31 words
A thermally stable composition according to claim 2 in which the concentration of said alkali metal monomethyl terephthalate is 1-20 parts by weight per million parts by weight of said DMT.
Claim 5
Dependent Claim
19 words
A thermally stable composition according to claim 3 in which said alkali metal monomethyl terephthalate is potassium monomethyl terephthalate.
Claim 6
Dependent Claim
52 words
A process for stabilizing thermally unstable fresh dimethyl terephthalate of extremely high purity, free of alkali metal compound material, having no significant concentration of either phosphonic acid moiety or phosphite moiety, and produced by the cooxidation-esterification process, which comprises incorporating into said dimethyl terephthalate a stabilizing quantity of alkali metal monomethyl terephthalate.
Claim 7
Dependent Claim
52 words
A process for stabilizing thermally unstable fresh dimethyl terephthalate of extremely high purity, free of alkali metal compound material, having no significant concentration of either phosphonic acid moiety or phosphite moiety, and produced by the cooxidation-esterification process, which comprises incorporating into said dimethyl terephthalate a stabilizing quantity of alkali metal monomethyl terephthalate.
Claim 8
Dependent Claim
27 words
A process according to claim 5 in which said quantity is about 0.5 to about 500 parts by weight per million parts by weight of said DMT.
Claim 9
Dependent Claim
29 words
A process according to claim 6 in which the quantity of said alkali metal monomethyl terephthalate is 1-20 parts by weight per million parts by weight of said DMT.
Claim 10
Dependent Claim
17 words
A process according to claim 7 in which said alkali metal monomethyl terephthalate is potassium monomethyl terephthalate.
References Cited (Backward Citations)
US3461153A
Cited
US3642871A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-11-14 | 1981-05-16 | 1981-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-11-14 | 1985-05-16 | 1985-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-11-14 | 1989-05-16 | 1989-11-15 | $7700.00 | Window Closed / Lapsed |