US4624888A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Acetylene (ethynyl) terminated polyimide siloxane and process for preparation thereof
Assignee: National Aeronautics and Space Administration
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Filing: 1985-09-30
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Granted: 1986-11-25
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Expires: 2005-09-30
Abstract
Abstract Siloxane-containing addition polyimides having improved physical property characteristics of flexibility, drape, tack and toughness and the process for preparing and utilizing same are disclosed.
Inventors
- 👤 Terry L. St. Clair
- 👤 Shubha Maudgal
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 07:03
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1057; C08G73/106; C08J; C08J5/00; C08J5/24; C08J5/241; C08J5/243; C08J2379/00; C08J2379/04; C08J2379/08; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31652; Y10T428/31663; Y10T442/00; Y10T442/20; Y10T442/2369; Y10T442/30; Y10T442/3146
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
113 words
A composition of matter consisting of a blend containing (a) 90-10% of an acetylene terminated oligomer having the formula: ##STR3## and (b) 10-90% of the oligomer produced by: combining an aminiophenylacetylene and an aromatic dianhydride in molar ratio quantities selected from the molar ratio group consisting of 1:1, 2:3, and 1:2 molar ratios in a solvent; permitting the combined solution to react for approximately one hour; adding a quantity of a diaminosiloxane to the reacted solution equal to a 0.5, 2, and 1.5 multiple of the respective molar ratio quantity selected for the aminophenylacetylene and aromatic dianhydride; and permitting the resulting solution to react for approximately one and one-half hours at room temperature.
Claim 2
Dependent Claim
113 words
A composition of matter consisting of a blend containing (a) 90-10% of an acetylene terminated oligomer having the formula: ##STR3## and (b) 10-90% of the oligomer produced by: combining an aminiophenylacetylene and an aromatic dianhydride in molar ratio quantities selected from the molar ratio group consisting of 1:1, 2:3, and 1:2 molar ratios in a solvent; permitting the combined solution to react for approximately one hour; adding a quantity of a diaminosiloxane to the reacted solution equal to a 0.5, 2, and 1.5 multiple of the respective molar ratio quantity selected for the aminophenylacetylene and aromatic dianhydride; and permitting the resulting solution to react for approximately one and one-half hours at room temperature.
Claim 3
Dependent Claim
34 words
The composition of claim 1, wherein the aromatic dianhydride is selected from the group consisting of: (a) benzophenone tetracarboxylic dianhydride; (b) pyromellitic dianhydride; (c) oxydiphthalic anhydride; (d) 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride; and (e) 4,4'-bis(3,4-dicarboxyphenoxy)diphenyl sulfide dianhydride.
Claim 4
Dependent Claim
59 words
A prepreg prepared by applying the oligomer blend of claim 1 onto a graphite cloth, air drying the coated graphite cloth for approximately one-half hour at approximately 100° C., and imidizing for approximately one hour at approximately 130° C. to yield a prepreg having improved physical properties of drape, tack, and adaptability for cutting and forming into shaped layers.
Claim 5
Dependent Claim
71 words
A shaped composite article prepared by cutting the prepreg of claim 3 into a plurality of segments having the desired shape and size, stacking the cut segments into a multiplied preform, heating the preform to approximately 200° C. and maintaining this temperature while applying to the preform a pressure of approximately 1000 psi for approximately one hour, and maintaining this pressure while permitting the resulting laminate to cool to room temperature.
Claim 6
Dependent Claim
44 words
The shaped composite article of claim 4, wherein the preform is heated to approximately 200° C. at a rate of 5° C. per minute so that a smooth transition of the imidized polymer is effected through the liquid state into a final crosslinked system.
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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) | 1989-11-24 | 1990-05-26 | 1990-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-11-24 | 1994-05-26 | 1994-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-11-24 | 1998-05-26 | 1998-11-25 | $7700.00 | Window Closed / Lapsed |