US4501713A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stabilizing melt crystallization temperature in arylene sulfide polymer heat treatment
Assignee: Phillips Petroleum Co
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Filing: 1983-06-15
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Granted: 1985-02-26
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Expires: 2003-06-15
Abstract
Abstract A method for stabilizing the Tmc of PPS subjected to heat treatment in a temperature range between 240° C. and 320° C., particularly during the heating process of an extrusion operation, by increasing the tmperature of the polymer through the 240° C.-320° C. range at a rate of at least 20° C. per minute or by subsequently raising the temperature of the polymer to at least 350° C. for a time sufficient to stabilize the Tmc of the polymer.
Inventors
- 👤 Roy F. Wright
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:03
CPC Classifications
C; C08; C08G; C08G75/00; C08G75/02; C08G75/0204; C08G75/0277; Y; Y10; Y10S; Y10S264/00; Y10S264/65
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
54 words
A method for stabilizing the Tmc of PPS subjected to heat treatment in a range up to about 320° C., said method comprising heating said PPS at a rate of temperature increase in a range of at least 20° C. per minute in the range of temperature of between 240° C. and 320° C.
Claim 2
Independent Claim
54 words
A method for stabilizing the Tmc of PPS subjected to heat treatment in a range up to about 320° C., said method comprising heating said PPS at a rate of temperature increase in a range of at least 20° C. per minute in the range of temperature of between 240° C. and 320° C.
Claim 3
Independent Claim
44 words
A method for stabilizing Tmc in PPS subjected to heat treatment in a range up to about 320° C., said method comprising maintaining the temperature of said PPS at a temperature above at least 350° C. for a time sufficient to stabilize the Tmc.
Claim 4
Independent Claim
44 words
A method for stabilizing Tmc in PPS subjected to heat treatment in a range up to about 320° C., said method comprising maintaining the temperature of said PPS at a temperature above at least 350° C. for a time sufficient to stabilize the Tmc.
Claim 5
Dependent Claim
26 words
A method of claim 2 wherein said time of maintaining temperature above 350° C. is in a range of about 0.1 minutes to about 20 minutes.
Claim 6
Independent Claim
57 words
A method for alleviating an increase of Tmc caused by heating PPS at a rate of temperature increase of less than about 20° C. per minute in the temperature range between 240° C. and 320° C. said method comprising maintaining the temperature of said polymer above about 350° C. for a time sufficient to stabilize the Tmc.
Claim 7
Independent Claim
57 words
A method for alleviating an increase of Tmc caused by heating PPS at a rate of temperature increase of less than about 20° C. per minute in the temperature range between 240° C. and 320° C. said method comprising maintaining the temperature of said polymer above about 350° C. for a time sufficient to stabilize the Tmc.
Claim 8
Dependent Claim
26 words
A method of claim 4 wherein said time of maintaining temperature above 350° C. is in a range of about 0.1 minutes to about 20 minutes.
Claim 9
Dependent Claim
66 words
In the extrusion of PPS at a temperature in a range of about 300° C. to about 360° C. a method for stabilizing the melt crystallization temperature of polymer exiting the extruder comprising maintaining the temperature of at least the inlet zone of said extruder at a temperature within a range sufficiently elevated to stabilize the Tmc of said PPS by the method of claim 1.
Claim 10
Dependent Claim
35 words
A method of claim 6 wherein said PPS is preheated in a preheating zone to a temperature in the range of about 220° C. to about 260° C. prior to entry into said inlet zone.
Claim 11
Dependent Claim
50 words
In the extrusion of PPS at a temperature in a range of about 300° C. to about 360° C. a method for stabilizing the melt crystallization temperature of polymer exiting the extruder comprising maintaining the temperature of at least one zone of said extruder by the method of claim 2.
Claim 12
Dependent Claim
26 words
A method of claim 8 wherein said time of maintaining temperature above 350° C. is in a range of about 0.1 minutes to about 20 minutes.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-02-26 | 1988-08-27 | 1989-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-26 | 1992-08-27 | 1993-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-26 | 1996-08-27 | 1997-02-26 | $7700.00 | Window Closed / Lapsed |