US3876435A
Expired / Lapsed
US
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Chromate conversion coating solutions having chloride, sulfate, and nitrate anions
Assignee: Henkel Corp
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Filing: 1973-10-01
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Granted: 1975-04-08
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Expires: 1993-10-01
Abstract
Abstract A coating solution and method for producing a chromate conversion coating on aluminum surfaces wherein soft or deionized water is employed as the diluent, the coating solution comprised of soft or deionized water, hexavalent chromium, fluoride, and an anion or anions selected from the group consisting of nitrate, chloride, and sulfate. The presence of the anions therein improves the characteristics of the corrosion resistant coating formed on aluminum surfaces, to which can be applied an organic finish such as a paint, lacquer, enamel or the like.
Inventors
- 👤 David Y Dollman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:06
CPC Classifications
C; C23; C23C; C23C22/00; C23C22/05; C23C22/06; C23C22/34; C23C22/37
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
183 words
IN THE METHOD OF APPLYING A CHROMATE CONVERSION COATING TO AN ALUMINUM SURFACE WHEREIN THE SURFACE IS CONTACTED WITH AN AQUEOUS COATING SOLUTION COMPRISING HEXAVALENT CHROMIUM AND FLUORIDE; THE IMPROVEMENT COMPRISING WHEN SOFT OR DEIONIZED WATER IS PRESENT IN THE SOLUTION, ONE OR MORE ANIONS SELECTED FROM THE GROUP CONSISTING OF NITRATE, CHLORIDE AND SULFATE IS INCORPORATED IN THE SOLUTION WHEREIN WHEN NITRATE IS PRESENT IN THE SOLUTION IT IS PRESENT IN THE AMOUNT OF FROM ABOUT 0.1 GRAMS/LITER TO ABOUT 3.0 GRAMS/LITER AND; WHEN IS PRESENT IN THE SOLUTION, IT IS PRESENT IN THE AMOUNT OF FROM ABOUT 0.005 GRAMS/LITER TO ABOUT 0.2 GRAMS/LITER AND; WHEN SULFATE IS PRESENT IN THE SOLUTION, IT IS PRESENT IN THE AMOUNT OF FROM ABOUT 0.005 TO 0.2 GRAMS/LITER AND; WHEREIN WHEN CHLORIDE AND SULFATE ARE PRESENT IN THE COATING SOLUTION, THEY ARE PRESENT IN AN AGGREGATE CONCENTRATION OF FROM ABOUT 0.01 GRAMS/LITER TO ABOUT 0.2 GRAMS/LITER; AND WHEREIN WHEN NITRATE, CHLORIDE AND SULFATE ARE PRESENT IN THE COATING SOLUTION, THEY ARE PRESENT IN A AGGREGATE CONCENTRATION OF FROM ABOUT 0.12 GRAMS/LITER TO ABOUT 3.2 GRAMS/LITER.
Claim 2
Dependent Claim
183 words
IN THE METHOD OF APPLYING A CHROMATE CONVERSION COATING TO AN ALUMINUM SURFACE WHEREIN THE SURFACE IS CONTACTED WITH AN AQUEOUS COATING SOLUTION COMPRISING HEXAVALENT CHROMIUM AND FLUORIDE; THE IMPROVEMENT COMPRISING WHEN SOFT OR DEIONIZED WATER IS PRESENT IN THE SOLUTION, ONE OR MORE ANIONS SELECTED FROM THE GROUP CONSISTING OF NITRATE, CHLORIDE AND SULFATE IS INCORPORATED IN THE SOLUTION WHEREIN WHEN NITRATE IS PRESENT IN THE SOLUTION IT IS PRESENT IN THE AMOUNT OF FROM ABOUT 0.1 GRAMS/LITER TO ABOUT 3.0 GRAMS/LITER AND; WHEN IS PRESENT IN THE SOLUTION, IT IS PRESENT IN THE AMOUNT OF FROM ABOUT 0.005 GRAMS/LITER TO ABOUT 0.2 GRAMS/LITER AND; WHEN SULFATE IS PRESENT IN THE SOLUTION, IT IS PRESENT IN THE AMOUNT OF FROM ABOUT 0.005 TO 0.2 GRAMS/LITER AND; WHEREIN WHEN CHLORIDE AND SULFATE ARE PRESENT IN THE COATING SOLUTION, THEY ARE PRESENT IN AN AGGREGATE CONCENTRATION OF FROM ABOUT 0.01 GRAMS/LITER TO ABOUT 0.2 GRAMS/LITER; AND WHEREIN WHEN NITRATE, CHLORIDE AND SULFATE ARE PRESENT IN THE COATING SOLUTION, THEY ARE PRESENT IN A AGGREGATE CONCENTRATION OF FROM ABOUT 0.12 GRAMS/LITER TO ABOUT 3.2 GRAMS/LITER.
Claim 3
Dependent Claim
19 words
A method according to claim 1 wherein the source of said anions is a water soluble acid or salt.
Claim 4
Dependent Claim
14 words
A method according to claim 1 wherein ferricyanide is present in said coating solution.
Claim 5
Dependent Claim
152 words
An aqueous coating solution comprising hexavalent chromium, fluoride, soft or deionized water, and one or more anions selected from the group consisting of nitrate, chloride and sulfate; wherein when nitrate is present in the solution it is present in the amount of from about 0.01 grams/liter to about 3.0 grams/liter; when chloride is present in the solution, it is present in the amount of from about 0.005 grams/liter to about 0.2 grams/liter and; when sulfate is present in the solution it is present in the amount of from about 0.005 grams/liter to about 0.2 grams/liter and; wherein when chloride and sulfate are present in the coating solution, they are present in an aggregate concentration of from about 0.01 grams/liter to about 0.02 grams/liter; and wherein when nitrate, chloride and sulfate are present in the coating solution, they are present in an aggregate concentration of from about 0.12 grams/liter to about 3.2 grams/liter.
Claim 6
Dependent Claim
152 words
An aqueous coating solution comprising hexavalent chromium, fluoride, soft or deionized water, and one or more anions selected from the group consisting of nitrate, chloride and sulfate; wherein when nitrate is present in the solution it is present in the amount of from about 0.01 grams/liter to about 3.0 grams/liter; when chloride is present in the solution, it is present in the amount of from about 0.005 grams/liter to about 0.2 grams/liter and; when sulfate is present in the solution it is present in the amount of from about 0.005 grams/liter to about 0.2 grams/liter and; wherein when chloride and sulfate are present in the coating solution, they are present in an aggregate concentration of from about 0.01 grams/liter to about 0.02 grams/liter; and wherein when nitrate, chloride and sulfate are present in the coating solution, they are present in an aggregate concentration of from about 0.12 grams/liter to about 3.2 grams/liter.
Claim 7
Dependent Claim
153 words
An aqueous coating solution comprising hexavalent chromium, fluoride, ferricyanide, soft or deionized water, and one or more anions selected from the group consisting of nitrate, chloride, and sulfate; wherein when nitrate is present in the solution it is present in the amount of from about 0.1 grams/liter to about 3.0 grams/liter; when chloride is present in the solution, it is present in the amount of from about 0.005 grams/liter to about 0.2 grams/liter and; when sulfate is present in the solution, it is present in the amount of from about 0.005 grams/liter to about 0.2 grams/liter; and wherein when chloride and sulfate are present in the coating solution, they are present in an aggregate concentration of from about 0.01 grams/liter to about 0.2 grams/liter; and wherein when nitrate, chloride, and sulfate are present in the coating solution, they are present in an aggregate concentration of from about 0.12 grams/liter to about 3.2 grams/liter.
Claim 8
Dependent Claim
153 words
An aqueous coating solution comprising hexavalent chromium, fluoride, ferricyanide, soft or deionized water, and one or more anions selected from the group consisting of nitrate, chloride, and sulfate; wherein when nitrate is present in the solution it is present in the amount of from about 0.1 grams/liter to about 3.0 grams/liter; when chloride is present in the solution, it is present in the amount of from about 0.005 grams/liter to about 0.2 grams/liter and; when sulfate is present in the solution, it is present in the amount of from about 0.005 grams/liter to about 0.2 grams/liter; and wherein when chloride and sulfate are present in the coating solution, they are present in an aggregate concentration of from about 0.01 grams/liter to about 0.2 grams/liter; and wherein when nitrate, chloride, and sulfate are present in the coating solution, they are present in an aggregate concentration of from about 0.12 grams/liter to about 3.2 grams/liter.
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) | 1978-04-07 | 1978-10-07 | 1979-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-07 | 1982-10-07 | 1983-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-07 | 1986-10-07 | 1987-04-08 | $7700.00 | Window Closed / Lapsed |