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US4045408A
Expired / Lapsed
US
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Fluoro-anhydride curing agents and precursors thereof for fluorinated epoxy resins
Assignee: United States Department of the Navy
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Filing: 1976-03-19
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Granted: 1977-08-30
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Expires: 1996-03-19
Abstract
Abstract Fluoro-anhydride curing agents for fluorinated epoxy resins, especially for highly fluorinated epoxy resins selected from the class consisting of hydroxyperfluoroalkyl phthalic anhydride, hydroxyperfluoroalkyl pyromellitic dianhydride, and mixtures thereof; a fluoro-anhydride curing agent for fluorinated epoxy resins that is the toluene-soluble mixture prepared by heating a hydroxyperfluoroalkyl benzenepentacarboxylic acid at about 240° C; precursors for all of the curing agents; and the epoxy resins prepared therefrom.
Inventors
- 👤 James R. Griffith
- 👤 Jacques G. O'Rear
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 08:02
CPC Classifications
C; C08; C08G; C08G59/00; C08G59/18; C08G59/40; C08G59/42; C08G59/4223; C08G59/20; C08G59/22; C08G59/30
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
28 words
A precursor of a curing agent for fluorinated epoxy resins selected from the class consisting of hydroxyperfluoroalkyl phthalic acid, hydroxyperfluoroalkyl pyromellitic acid, hydroxyperfluoroalkyl benzenepentacarboxylic acid, and mixtures thereof.
Claim 2
Dependent Claim
28 words
A precursor of a curing agent for fluorinated epoxy resins selected from the class consisting of hydroxyperfluoroalkyl phthalic acid, hydroxyperfluoroalkyl pyromellitic acid, hydroxyperfluoroalkyl benzenepentacarboxylic acid, and mixtures thereof.
Claim 3
Dependent Claim
31 words
The precursor of claim 1 wherein said hydroxyperfluoroalkyl phthalic acid is 4-(2-hydrohexafluoro-2-propyl) phthalic acid said hydroxyperfluoroalkyl pyromellitic acid is 2-hydroxyhexa-fluoro-2-propyl pyromellitic acid, and said hydroxyperfluoroalkyl benzene-pentacarboxylic acid is 2-hydroxyhexafluoro-2-propyl benzene-pentacarboxylic acid.
Claim 4
Dependent Claim
22 words
A curing agent for fluorinated epoxy resins selected from the class consisting of hydroxyperfluoroalkyl phthalic anhydride, hydroxyperfluoroalkyl pyromellitic dianhydride and mixtures thereof.
Claim 5
Dependent Claim
22 words
A curing agent for fluorinated epoxy resins selected from the class consisting of hydroxyperfluoroalkyl phthalic anhydride, hydroxyperfluoroalkyl pyromellitic dianhydride and mixtures thereof.
Claim 6
Dependent Claim
24 words
The curing agent of claim 3 wherein said hydroxyperfluoroalkyl phthalic anhydride is 4-(2-hydroxyhexafluoro-2-propyl) phthalic anhydride and said hydroxyperfluoroalkyl pyromellitic dianhydride is 2-hydroxyhexafluoro-2-propyl pyromellitic dianhydride.
Claim 7
Dependent Claim
31 words
A curing agent for fluorinated epoxy resins which is the toluene soluble portion of the product prepared by heating a hydroxyperfluoroalkyl benzenepentacarboxylic acid at a temperature from 235° to 250° C.
Claim 8
Dependent Claim
31 words
A curing agent for fluorinated epoxy resins which is the toluene soluble portion of the product prepared by heating a hydroxyperfluoroalkyl benzenepentacarboxylic acid at a temperature from 235° to 250° C.
Claim 9
Dependent Claim
26 words
The curing agent of claim 5 wherein said hydroxyperfluoroalkyl benzene pentacarboxylic acid is 2-hydroxyhexafluoro-2-propyl benzene-pentacarboxylic acid and said reaction temperature is from 240° to 245° C.
Claim 10
Dependent Claim
15 words
The resinous copolymer of a fluorinated epoxy resin and a curing agent of claim 3.
Claim 11
Dependent Claim
15 words
The copolymer of claim 7 wherein the fluorinated epoxy resin is a fluorinated diglycidyl ether.
Claim 12
Dependent Claim
15 words
The resinous copolymer of a fluorinated epoxy resin and a curing agent of claim 5.
Claim 13
Dependent Claim
15 words
The copolymer of claim 9 wherein the fluorinated epoxy resin is a fluorinated diglycidyl ether.
References Cited (Backward Citations)
US3281426A
Cited
US3899517A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-08-29 | 1981-02-28 | 1981-08-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-29 | 1985-02-28 | 1985-08-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-29 | 1989-02-28 | 1989-08-30 | $7700.00 | Window Closed / Lapsed |