US5069848A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Extrusion process of polyimide and polyimide pellet used for the process
Assignee: Mitsui Chemicals Inc
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Filing: 1990-03-26
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Granted: 1991-12-03
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Expires: 2010-03-26
Abstract
Abstract Polyimide which is obtained by polymerization and consists essentially of recurring structural units of the formula (I): <IMAGE> (I) <IMAGE> wherein X is a single bond or a hexafluoroisopropylidene group, is processed to a form of pellet, followed by heat-treating to obtain crystallinity of 5% or more, and fed to an extruder to obtain articles.
Inventors
- 👤 Masumi Saruwatari
- 👤 Syoichi Tsuji
- 👤 Yasuhiro Fujii
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:54
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/022; C; C08; C08J; C08J3/00; C08J3/12; B29B; B29B9/00; B29B9/02; B29B9/06; B29B9/10; B29B9/12; B29C48/03; B29C48/04; B29C48/05; B29C48/06; B29C48/07; B29C48/08; B29C48/09; B29C48/10; B29C48/25; B29C48/78; B29C48/793; B29C48/80; B29C48/83; B29C48/832; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1067; C08G73/1071; B29K; B29K2079/00; C08J2379/00; C08J2379/04; C08J2379/08
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
61 words
A process for extruding polyimide comprising the steps of pelletizing a polyimide consisting essentially of recurring structural units represented by the formula (I) ##STR6## wherein X is a single bond or a hexafluoroisopropylidene group, conducting heat-treatment of the resulting pellets to obtain a crystalline polyimide having a crystallinity of 5% or more and feeding the crystalline polyimide pellets to an extruder.
Claim 2
Dependent Claim
61 words
A process for extruding polyimide comprising the steps of pelletizing a polyimide consisting essentially of recurring structural units represented by the formula (I) ##STR6## wherein X is a single bond or a hexafluoroisopropylidene group, conducting heat-treatment of the resulting pellets to obtain a crystalline polyimide having a crystallinity of 5% or more and feeding the crystalline polyimide pellets to an extruder.
Claim 3
Dependent Claim
19 words
The process of claim 1 wherein the heat-treatment is conducted at a temperature of from 250° to 370° C.
Claim 4
Dependent Claim
13 words
The process of claim 1 wherein the crystallinity is from 5 to 50%.
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) | 1994-12-02 | 1995-06-03 | 1995-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-02 | 1999-06-03 | 1999-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-02 | 2003-06-03 | 2003-12-03 | $7700.00 | Window Closed / Lapsed |