Patent US4448847A successfully refreshed from Google Patents.
US4448847A
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Process for improving steel-epoxy adhesion
Assignee: Shell USA Inc
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Filing: 1982-05-28
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Granted: 1984-05-15
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Expires: 2002-05-28
Abstract
Abstract The present invention is directed to a method for improving the adhesion of epoxy resins to steel substrates which comprises first removing the oxide surface layer, preferably by chemical means, and then pretreating the substrate with a solution of at least one coupling agent selected from the group consisting of β-diketones and mercaptoesters. The invention also provides a method for improving the adhesion of epoxy resins to steel substrates by pretreating with citric acid or a salt thereof.
Inventors
- 👤 James P. Bell
- 👤 Anthony J. De Nicola, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:41
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/12; C08J2363/00; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31511; Y10T428/31529; Y10T428/31678
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
116 words
A method for improving the adhesion of epoxy resins to steel substrates which comprises (1) chemically removing the oxide layer from said substrate and (2) pretreating said cleaned substrate with a solution of at least one coupling agent selected from the group consisting of β-diketones of the general formula ##STR8## wherein R is H or an alkyl radical, Y and Y' are each (symetrical or assymetrical) aliphatic, cycloaliphatic or aromatic radicals, A is O, S, N, or CH 2 , X and X' are each an aromatic OH, carboxyl, glycidyl, glycidyl ether, glycidyl ester or --CH 2 OH group and a mercaptoester of the general formula: ##STR9## wherein X and X' are each H or ##STR10##
Claim 2
Independent Claim
116 words
A method for improving the adhesion of epoxy resins to steel substrates which comprises (1) chemically removing the oxide layer from said substrate and (2) pretreating said cleaned substrate with a solution of at least one coupling agent selected from the group consisting of β-diketones of the general formula ##STR8## wherein R is H or an alkyl radical, Y and Y' are each (symetrical or assymetrical) aliphatic, cycloaliphatic or aromatic radicals, A is O, S, N, or CH 2 , X and X' are each an aromatic OH, carboxyl, glycidyl, glycidyl ether, glycidyl ester or --CH 2 OH group and a mercaptoester of the general formula: ##STR9## wherein X and X' are each H or ##STR10##
Claim 3
Dependent Claim
24 words
The method of claim 1 wherein the β-diketone has the general formula: ##STR11## wherein (1) R=R'=H; or (2) R=H, and R' is --OH, ##STR12##
Claim 4
Dependent Claim
10 words
The method of claim 2 wherein the β-diketone is 1-(o-hydroxyphenyl)-3-phenyl-1,3-propanedione.
Claim 5
Dependent Claim
10 words
The method of claim 2 wherein the β-diketone is 1,3-diphenyl-1,3-propanedione.
Claim 6
Dependent Claim
11 words
The method of claim 1 wherein the mercaptoester is pentaaerythritol tetrathioglycolate.
Claim 7
Dependent Claim
11 words
The method of claim 1 wherein the mercaptoester is pentaaerythritol tetra-3-mercaptopropionate.
Claim 8
Dependent Claim
11 words
The method of claim 1 wherein the mercaptoester is 1,2,6-hexanetriol tetra-4-mercaptobutyrate.
Claim 9
Dependent Claim
11 words
The method of claim 1 wherein the mercaptoester is 1,2,6-hexane trithioglycolate.
Claim 10
Dependent Claim
18 words
The method of claim 1 wherein the coupling agent is employed in a 0.001 to 0.1 molar solution.
Claim 11
Dependent Claim
34 words
The method of claim 9 wherein the steel substrate is immersed in the coupling agent solution at from about 15° C. to about 100° C. for from about 10 seconds to about 10 hours.
Claim 12
Dependent Claim
23 words
The method of claim 1 wherein the oxide layer is removed by pretreatment with a solution of citric acid or a salt thereof.
Claim 13
Dependent Claim
11 words
The method of claim 11 wherein the solution is ammonium citrate.
Claim 14
Dependent Claim
18 words
The method of claim 11 wherein the solution has a pH of from about 5.5 to about 9.5.
Claim 15
Dependent Claim
19 words
The method of claim 11 wherein the solution is utilized at a temperature between about 50° and 70° C.
Claim 16
Dependent Claim
31 words
An article of construction comprising at least one steel substrate and an adhesive layer comprising a cured epoxy resin composition, said steel substrate being pretreated by the method of claim 1.
Claim 17
Dependent Claim
15 words
The article of claim 15 wherein the epoxy resin is a glycidyl polyether of 2,2-bis(4-hydroxyphenyl)propane.
Claim 18
Dependent Claim
14 words
The article of claim 15 wherein the epoxy curing agent is an amino-containing compound.
Claim 19
Dependent Claim
11 words
The article of claim 17 wherein the amino-containing compound is methylenedianiline.
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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) | 1987-05-15 | 1987-11-14 | 1988-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-15 | 1991-11-14 | 1992-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-15 | 1995-11-14 | 1996-05-15 | $7700.00 | Window Closed / Lapsed |