US4145522A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyimide from amino substituted 4-t-butylphthalic anhydride
Assignee: BP Corp North America Inc
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Filing: 1977-09-08
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Granted: 1979-03-20
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Expires: 1997-09-08
Abstract
Abstract Novel amino-substituted derivatives of 4-t-butylphthalic anhydride are used as monomers to produce novel polyimides with improved solubility characteristics. Increased solubility in organic solvents permits these polyimides to be used in coating applications where structurally similar polyimides could not otherwise be used.
Inventors
- 👤 Robert G. Keske
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:47
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1067
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
32 words
A thermally stable solid polyimide containing at least 1 percent of a structural unit of the formula ##STR6## wherein the dangling cross valence extending from the benzene moiety represents the t-butyl substituent.
Claim 2
Dependent Claim
32 words
A thermally stable solid polyimide containing at least 1 percent of a structural unit of the formula ##STR6## wherein the dangling cross valence extending from the benzene moiety represents the t-butyl substituent.
Claim 3
Dependent Claim
16 words
The thermally stable polyimide of claim 1 consisting essentially of repeating units of the formula ##STR7##
Claim 4
Dependent Claim
80 words
The thermally stable polyimide of claim 1 consisting essentially of first and second recurring structural units, said first unit having the following formula wherein the dangling cross valence extending from the benzene moiety represents the t-butyl substituent ##STR8## and said second unit having the following formula ##STR9## wherein said first recurring structural unit are present in amounts from 1 to 99 weight percent and said second recurring structural units are correspondingly present in amounts from 99 to 1 weight percent.
References Cited (Backward Citations)
US3450678A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-03-19 | 1982-09-18 | 1983-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-03-19 | 1986-09-18 | 1987-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-03-19 | 1990-09-18 | 1991-03-20 | $7700.00 | Window Closed / Lapsed |