US4039353A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Post-treatment of conversion-coated metal surfaces
Assignee: Henkel Corp
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Filing: 1975-11-13
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Granted: 1977-08-02
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Expires: 1995-11-13
Abstract
Abstract Disclosed is a process for the post-treatment of conversion-coated metal surfaces. The aqueous treating solution contains a melamine-formaldehyde resin and preferably contains a vegetable tannin and is free of chromium. Treatment with the melamine-formaldehyde resin-containing solution provides improved corrosion-resistance over that obtained with a water rinse and treatment with the melamine-formaldehyde resin and vegetable tannin combination solution gives corrosion results as measured by salt spray resistance comparable to those obtained with the use of the commercial dilute chromium-containing rinse.
Inventors
- 👤 Leonard Kulick
- 👤 John K. Howell, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 11:23
CPC Classifications
C; C23; C23C; C23C22/00; C23C22/82; C23C22/83
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
57 words
In a method of post-treating a phosphate or chromate conversion coated metal surface without the use of chromium chemicals, the improvement comprising contacting said surface with an aqueous solution comprising at least 0.01 g/l of a melamine-formaldehyde resin and at least 0.01 g/l of a vegetable tannin wherein the weight ratio of resin:tannin is at least 1:1.
Claim 2
Dependent Claim
57 words
In a method of post-treating a phosphate or chromate conversion coated metal surface without the use of chromium chemicals, the improvement comprising contacting said surface with an aqueous solution comprising at least 0.01 g/l of a melamine-formaldehyde resin and at least 0.01 g/l of a vegetable tannin wherein the weight ratio of resin:tannin is at least 1:1.
Claim 3
Dependent Claim
16 words
The method of claim 1 wherein said resin concentration is not in excess of 100 g/l.
Claim 4
Dependent Claim
15 words
The method of claim 2 wherein the resin concentration is from 0.25 to 25 g/l.
Claim 5
Dependent Claim
17 words
The method of claim 1 wherein the pH of said solution is not in excess of 10.
Claim 6
Dependent Claim
15 words
The method of claim 1 wherein the post-treated surface is dried at an elevated temperature.
Claim 7
Dependent Claim
12 words
The method of claim 1 wherein the vegetable tannin is an extract.
Claim 8
Dependent Claim
28 words
The method of claim 1 wherein the melamine-formaldehyde resin is selected from the group consisting of the methylolated melamines and the C 1 -C 4 alkyl derivatives thereof.
Claim 9
Dependent Claim
42 words
An aqueous concentrate composition useful for the post-treatment of a phosphate or chromate conversion coated metal surface comprising 1- 80 wt. % melamine-formaldehyde and 1- 40 wt. % of a vegetable tannin wherein the weight ratio of resin:tannin is at least 1:1.
Claim 10
Dependent Claim
42 words
An aqueous concentrate composition useful for the post-treatment of a phosphate or chromate conversion coated metal surface comprising 1- 80 wt. % melamine-formaldehyde and 1- 40 wt. % of a vegetable tannin wherein the weight ratio of resin:tannin is at least 1:1.
Claim 11
Dependent Claim
12 words
The concentrate of claim 8 wherein the vegetable tannin is an extract.
Claim 12
Dependent Claim
28 words
The concentrate of claim 8 wherein the melamine-formaldehyde resin is selected from the group consisting of the methylolated melamines and the C 1 -C 4 alkyl derivatives thereof.
Claim 13
Dependent Claim
13 words
The concentrate of claim 8 wherein said ratio is at least about 3.5:1.
Claim 14
Dependent Claim
13 words
The concentrate of claim 11 wherein said ratio is at least about 7.5:1.
Claim 15
Dependent Claim
25 words
The concentrate of claim 12 wherein the tannin is selected from the group of tannin extracts consisting of tannic acid, chestnut, quebracho, wattle and cutch.
Claim 16
Dependent Claim
42 words
An aqueous solution suitable for post-treating a phosphate or chromate conversion coated metal surface comprising at least 0.01 g/l of a melamine-formaldehyde resin and at least 0.01 g/l of a vegetable tannin wherein the weight ratio of resin:tannin is at least 1:1.
Claim 17
Dependent Claim
42 words
An aqueous solution suitable for post-treating a phosphate or chromate conversion coated metal surface comprising at least 0.01 g/l of a melamine-formaldehyde resin and at least 0.01 g/l of a vegetable tannin wherein the weight ratio of resin:tannin is at least 1:1.
Claim 18
Dependent Claim
13 words
The solution of claim 14 wherein said ratio is at least about 3.5:1.
Claim 19
Dependent Claim
13 words
The solution of claim 15 wherein said ratio is at least about 7.5:1.
Claim 20
Dependent Claim
14 words
The solution of claim 14 having a pH value not in excess of 10.
Claim 21
Dependent Claim
25 words
The solution of claim 14 wherein the tannin is selected from the group of tannin extracts consisting of tannic acid, chestnut, guebracho, wattle and cutch.
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) | 1980-08-01 | 1981-01-31 | 1981-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-01 | 1985-01-31 | 1985-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-01 | 1989-01-31 | 1989-08-02 | $7700.00 | Window Closed / Lapsed |