Patent US4237261A successfully refreshed from Google Patents.
US4237261A
Expired / Lapsed
US
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Process for continuously producing polyester and spun fiber
Assignee: Nippon Ester Co Ltd
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Filing: 1979-09-17
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Granted: 1980-12-02
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Expires: 1999-09-17
Abstract
Abstract In a process for continuously producing polyester which comprises continuously polymerizing bis-β-hydroxyethyl terephthalate and/or a lower polymer thereof using a plurality of vacuum polymerization reactors equipped with a stirrer disposed in series, the improvement which comprises automatically and continuously measuring stirring power or stirring axis reaction force of at least the final polymerization reactor among the polymerization reactors from which a polymer having a limiting viscosity (η) of 0.25 or more is removed, and controlling the vacuum in the polymerization reactors based on changes in the stirring power or reaction force so that the stirring power or reaction force is kept at a prescribed level, by which the degree of polymerization of the polymer removed from the polymerization reactors is controlled. A process for producing a polyester spun fiber is also disclosed.
Inventors
- 👤 Hideo Kawamura
- 👤 Ichiro Fukami
- 👤 Shuhei Wada
- 👤 Fusayuki Yoshikawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:35
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/78
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
120 words
In a continuous process for producing polyester which comprises continuously polymerizing bis-β-hydroxyethyl terephthalate and/or a lower polymer thereof using a plurality of vacuum polymerization reactors equipped with a stirrer and disposed in series, the improvement which comprises automatically and continuously measuring the stirring power or stirring axis reaction force of at least the final polymerization reactor from which a polymer having a limiting viscosity (η) of 0.25 or more is removed, and controlling the vacuum in the polymerization reactors according to changes in the stirring power or reaction force so that the stirring power or reaction force value is kept at a prescribed level, by which the degree of polymerization of the polymer removed from the polymerization reactors is controlled.
Claim 2
Dependent Claim
120 words
In a continuous process for producing polyester which comprises continuously polymerizing bis-β-hydroxyethyl terephthalate and/or a lower polymer thereof using a plurality of vacuum polymerization reactors equipped with a stirrer and disposed in series, the improvement which comprises automatically and continuously measuring the stirring power or stirring axis reaction force of at least the final polymerization reactor from which a polymer having a limiting viscosity (η) of 0.25 or more is removed, and controlling the vacuum in the polymerization reactors according to changes in the stirring power or reaction force so that the stirring power or reaction force value is kept at a prescribed level, by which the degree of polymerization of the polymer removed from the polymerization reactors is controlled.
Claim 3
Dependent Claim
23 words
The process of claim 1, wherein the stirring power or stirring axis reaction force of the last reactor in the series is measured.
Claim 4
Dependent Claim
35 words
The process of claim 1, wherein the stirring power or stirring axis reaction force of each of the reactors from which a polymer having a limiting viscosity of 0.25 or more is removed, is measured.
Claim 5
Dependent Claim
14 words
The process of claim 1, wherein said vacuum control is accomplished by cascade control.
Claim 6
Dependent Claim
14 words
The process of claim 1, wherein said vacuum control is accomplished by PID control.
Claim 7
Dependent Claim
131 words
In a process for producing a spun fiber from polyethylene terephthalate polymer which comprises continuously polymerizing bis-β-hydroxyethyl terephthalate and/or a lower polymer thereof using a plurality of vacuum polymerization reactors equipped with a stirrer and disposed in series, and spinning the continuously produced polymer, the improvement which comprises automatically and continuously measuring the stirring power or stirring axis reaction force of at least the final polymerization reactor from which a polymer having a limiting viscosity (η) of 0.25 or more is removed, and controlling the vacuum in the polymerization reactors according to changes in the stirring power or reaction force so that the stirring power or reaction force value is kept at a prescribed level, by which the degree of polymerization of the polymer removed from the polymerization reactor is controlled.
Claim 8
Dependent Claim
131 words
In a process for producing a spun fiber from polyethylene terephthalate polymer which comprises continuously polymerizing bis-β-hydroxyethyl terephthalate and/or a lower polymer thereof using a plurality of vacuum polymerization reactors equipped with a stirrer and disposed in series, and spinning the continuously produced polymer, the improvement which comprises automatically and continuously measuring the stirring power or stirring axis reaction force of at least the final polymerization reactor from which a polymer having a limiting viscosity (η) of 0.25 or more is removed, and controlling the vacuum in the polymerization reactors according to changes in the stirring power or reaction force so that the stirring power or reaction force value is kept at a prescribed level, by which the degree of polymerization of the polymer removed from the polymerization reactor is controlled.
Claim 9
Dependent Claim
28 words
The process for producing a spun fiber of claim 6, wherein the stirring power or stirring axis reaction force of the last reactor in the series is measured.
Claim 10
Dependent Claim
40 words
The process for producing a spun fiber of claim 6, wherein the stirring power or stirring axis reaction force of each of the reactors from which a polymer having a limiting viscosity of 0.25 or more is removed, is measured.
Claim 11
Dependent Claim
14 words
The process of claim 6, wherein said vacuum control is accomplished by cascade control.
Claim 12
Dependent Claim
14 words
The process of claim 6, wherein said vacuum control is accomplished by PID control.
Claim 13
Dependent Claim
38 words
The process of claims 1 or 6, wherein three polymerization reactors are used under the following conditions: ______________________________________
first reactor second reactor
third reactor
______________________________________
270-280° C.
270-285° C.
270-285° C.
15-30 Torr 3-6 Torr 0.5-3.0 Torr.
______________________________________
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) | 1983-12-02 | 1984-06-02 | 1984-12-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-02 | 1988-06-02 | 1988-12-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-02 | 1992-06-02 | 1992-12-02 | $7700.00 | Window Closed / Lapsed |