US3878244A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of terephthalic acid dichloride
Assignee: Akzo NV
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Filing: 1973-09-27
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Granted: 1975-04-15
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Expires: 1993-09-27
Abstract
Abstract Process for preparing terephthalic acid dichloride in high yields by chlorination of a mixture of polyethylene terephthalate and terephthalic acid at elevated temperatures and preferably at elevated pressures in the presence of an inert organic solvent, especially chlorinated hydrocarbons and acid chlorides.
Inventors
- 👤 Hans Zengel
- 👤 Dieter Frank
- 👤 Manfred Bergfeld
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:36
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/58; C07C51/60
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
82 words
A PROCESS FOR THE PRODUCTION OF TEREPHTHALIC ACID DICHLORIDE WHICH COMPRISES REACTING A MIXTURE OF POLYETHYLENE TEREPHTHALATE AND TEREPHTHALIC ACID WITH CHLORINE GAS AT A TEMPERATURE OF ABOUT 150*C. TO 350*C., SAID MIXTURE CONTAINING ABOUT 0.1 MOL UP TO ABOUT ONE MOL OF TEREPHTHALIC ACID PER MOL OF THE RECURRING ETHYLENE-TEREPHTHALOYL UNIT OF THE POLYETHLENE TEREPHTHALATE AND THE MOLAR RATIO OF SAID CHLORINE TO THE SUM OF SAID TERRPHTHALATE ACID AND SAID ETHYLENE-TEREPHTHALOYL UNITS BEING IN THE RANGE OF 3:1 TO 10:1.
Claim 2
Dependent Claim
82 words
A PROCESS FOR THE PRODUCTION OF TEREPHTHALIC ACID DICHLORIDE WHICH COMPRISES REACTING A MIXTURE OF POLYETHYLENE TEREPHTHALATE AND TEREPHTHALIC ACID WITH CHLORINE GAS AT A TEMPERATURE OF ABOUT 150*C. TO 350*C., SAID MIXTURE CONTAINING ABOUT 0.1 MOL UP TO ABOUT ONE MOL OF TEREPHTHALIC ACID PER MOL OF THE RECURRING ETHYLENE-TEREPHTHALOYL UNIT OF THE POLYETHLENE TEREPHTHALATE AND THE MOLAR RATIO OF SAID CHLORINE TO THE SUM OF SAID TERRPHTHALATE ACID AND SAID ETHYLENE-TEREPHTHALOYL UNITS BEING IN THE RANGE OF 3:1 TO 10:1.
Claim 3
Dependent Claim
21 words
A process as claimed in claim 1 wherein said reaction is carried out in the presence of an inert organic solvent.
Claim 4
Dependent Claim
29 words
A process as claimed in claim 2 wherein said inert organic solvent is at least one substance selected from the class consisting of chlorinated hydrocarbons and carboxylic acid chlorides.
Claim 5
Dependent Claim
30 words
A process as claimed in claim 2 wherein said inert organic solvent is selected from the class consisting of carbon tetrachloride, tetrachloroethylene, chlorobenzene, o-dichlorobenzene, terephthalic acid dichloride and mixtures thereof.
Claim 6
Dependent Claim
24 words
A process as claimed in claim 1 wherein said reaction is carried out at an elevated pressure of up to about 120 atmospheres gauge.
Claim 7
Dependent Claim
31 words
A process as claimed in claim 1 wherein said reaction is carried out at a temperature of about 180*C. to 250*C. and a gauge pressure of about 30 to 80 atmospheres.
Claim 8
Dependent Claim
21 words
A process as claimed in claim 6 wherein said reaction is carried out in the presence of an inert organic solvent.
Claim 9
Dependent Claim
29 words
A process as claimed in claim 7 wherein said inert organic solvent is at least one substance selected from the class consisting of chlorinated hydrocarbons and carboxylic acid chlorides.
Claim 10
Dependent Claim
30 words
A process as claimed in claim 7 wherein said inert organic solvent is selected from the class consisting of carbon tetrachloride, tetrachloroethylene, chlorobenzene, o-dichlorobenzene, terephthalic acid dichloride and mixtures thereof.
Claim 11
Dependent Claim
43 words
A process as claimed in claim 1 wherein said reaction is carried out at said temperature and at an elevated pressure for a period of time sufficient to obtain at least a 90 percent molar conversion of said mixture into terephthalic acid dichloride.
Claim 12
Dependent Claim
23 words
A process as claimed in claim 1 wherein the molar ratio of terephthalic acid to the recurring ethylene-terephthaloyl unit is 0.5:1 to 1:1.
References Cited (Backward Citations)
NL7116151A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-14 | 1978-10-14 | 1979-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-14 | 1982-10-14 | 1983-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-14 | 1986-10-14 | 1987-04-15 | $7700.00 | Window Closed / Lapsed |