Patent US4391965A successfully refreshed from Google Patents.
US4391965A
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US
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Curing agents
Assignee: HERMANN WIEDERHOLD A CORP OF GERMANY GmbH
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Filing: 1981-10-26
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Granted: 1983-07-05
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Expires: 2001-10-26
Abstract
Abstract A modified polycarboxylic acid polyanhydride curing agent suitable for curing epoxy resins which is prepared by reacting a polycarboxylic acid anhydride with a monohydroxy compound ROH; and coating compositions, comprising the modified curing agent and a solution of an epoxy resin to be cured, which have improved storage stability.
Inventors
- 👤 Hans R. Falkenburg
- 👤 Siegfried Krause
- 👤 Robert C. McGuiness
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 12:51
CPC Classifications
C; C09; C09D; C09D163/00; C08; C08G; C08G59/00; C08G59/18; C08G59/40; C08G59/42; C08G59/4223; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31511; Y10T428/31529
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
47 words
A coating composition which comprises in admixture (a) a curing agent which is the reaction product of a polycarboxylic acid polyanhydride with a monohydroxy compound ROH, wherein R is alkyl, substituted alkyl, or aralkyl and (b) a solution of an epoxy resin which is to be cured.
Claim 2
Dependent Claim
47 words
A coating composition which comprises in admixture (a) a curing agent which is the reaction product of a polycarboxylic acid polyanhydride with a monohydroxy compound ROH, wherein R is alkyl, substituted alkyl, or aralkyl and (b) a solution of an epoxy resin which is to be cured.
Claim 3
Dependent Claim
45 words
A coating composition according to claim 1 wherein the acid polyanhydride curing agent is heated with the monohydroxy compound ROH to a temperature greater than 60° C. for such a period of time that at least 50% of the anhydride groups are reacted with ROH.
Claim 4
Dependent Claim
15 words
A coating composition according to claim 1 wherein the temperature is greater than 100° C.
Claim 5
Dependent Claim
20 words
A curing agent according to claim 1 wherein at least 75% of the anhydride groups have been reacted with ROH.
Claim 6
Dependent Claim
23 words
A coating composition according to claim 1 wherein ROH is selected from the group an alkanol, an ether alkanol and a hydroxy ester.
Claim 7
Dependent Claim
20 words
A coating composition according to claim 1 wherein the polyanhydride is an adduct of trimellitic anhydride and a polyhydric alcohol.
Claim 8
Dependent Claim
19 words
A coating composition according to claim 6 wherein the polyanhydride is an adduct of trimellitic anhydride and ethylene glycol.
Claim 9
Dependent Claim
25 words
A coating composition according to claim 1 wherein there is also present a solvent selected from the group ester solvents, ketone solvents and aromatic solvents.
Claim 10
Dependent Claim
26 words
A cured coating on a substrate which is prepared by applying to a substrate a coating composition according to claim 1 and thereafter heating the substrate.
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) | 1986-07-04 | 1987-01-03 | 1987-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-07-04 | 1991-01-03 | 1991-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-07-04 | 1995-01-03 | 1995-07-05 | $7700.00 | Window Closed / Lapsed |