US4277292A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ternary corrosion resistant coatings
Assignee: Coral Chemical Co
•
Filing: 1980-03-26
•
Granted: 1981-07-07
•
Expires: 2000-03-26
Abstract
Abstract A highly acidic aqueous conversion coating for aluminum which is corrosion resistant, provides excellent adhesion with overlaying coatings and does not blacken when the coating substrate is immersed in boiling water. The coating composition is a ternary variety which contains zirconium, fluoride, and tannin. The pH of the coating bath is uniquely more acidic than conventional baths which operate at a pH of 3 and above, and is between 2.3 and 2.95.
Inventors
- 👤 George L. Tupper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:08
CPC Classifications
C; C23; C23C; C23C22/00; C23C22/05; C23C22/06; C23C22/34
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
80 words
An acidic aqueous coating solution for forming a corrosion resistant coating on aluminum consisting essentially of a ternary composition of zirconium, a soluble vegetable tannin, and a fluoride, wherein the concentration of the zirconium ion is 0.014 to 0.096 grams/liter, the vegetable tannin concentration is 0.060 to 0.024 grams/liter, and the fluoride concentration is 0.020 to 0.140 grams/liter, and excluding phosphate ion and a source of hydrogen ion to adjust the pH of the coating solution between 2.3 and 2.95.
Claim 2
Dependent Claim
80 words
An acidic aqueous coating solution for forming a corrosion resistant coating on aluminum consisting essentially of a ternary composition of zirconium, a soluble vegetable tannin, and a fluoride, wherein the concentration of the zirconium ion is 0.014 to 0.096 grams/liter, the vegetable tannin concentration is 0.060 to 0.024 grams/liter, and the fluoride concentration is 0.020 to 0.140 grams/liter, and excluding phosphate ion and a source of hydrogen ion to adjust the pH of the coating solution between 2.3 and 2.95.
Claim 3
Dependent Claim
15 words
A coating composition of claim 1 wherein the source of hydrogen ion is nitric acid.
Claim 4
Dependent Claim
26 words
A coating composition of claim 1 wherein the source of hydrogen ion is selected from the group consisting of nitric acid, acetic acid, and sulfuric acid.
Claim 5
Dependent Claim
68 words
An acidic aqueous coating solution for forming a corrosion resistant coating on aluminum consisting essentially of an composition of zirconium, a soluble vegetable tannin, a fluoride and nitric acid wherein the concentration of the zirconium ion is 0.014 to 0.096 grams/liter, the vegetable tannin concentration is 0.060 to 0.240 grams/liter, nitric is present in an amount to adjust the pH of the coating solution between 2.3 and 2.95.
Claim 6
Dependent Claim
68 words
An acidic aqueous coating solution for forming a corrosion resistant coating on aluminum consisting essentially of an composition of zirconium, a soluble vegetable tannin, a fluoride and nitric acid wherein the concentration of the zirconium ion is 0.014 to 0.096 grams/liter, the vegetable tannin concentration is 0.060 to 0.240 grams/liter, nitric is present in an amount to adjust the pH of the coating solution between 2.3 and 2.95.
Claim 7
Dependent Claim
62 words
A method of coating an aluminum substrate with a corrosion resistant coating comprising the steps of: I. preparing a clean, washed and rinsed aluminum surface; II. contacting the aluminum surface for about 30 seconds with a coating solution of claim 1; III. reacting said solution with the aluminum surface to produce an aluminum surface which is corrosion resistant and provides improved adhesion.
Claim 8
Dependent Claim
12 words
A method of claim 5, wherein the coating solution contains nitric acid.
Claim 9
Dependent Claim
42 words
A highly acidic aqueous coating solution having a pH between 2.3 and 2.95 and consisting essentially of 30-45 ppm zirconium ions, 75-125 ppm vegetable tannin, and 30-70 ppm fluoride, and excluding phosphate ion, suitable for forming a corrosion resistant coating on aluminum.
Claim 10
Dependent Claim
42 words
A highly acidic aqueous coating solution having a pH between 2.3 and 2.95 and consisting essentially of 30-45 ppm zirconium ions, 75-125 ppm vegetable tannin, and 30-70 ppm fluoride, and excluding phosphate ion, suitable for forming a corrosion resistant coating on aluminum.
Claim 11
Dependent Claim
11 words
A coating solution according to claim 7, which includes nitric acid.
Claim 12
Dependent Claim
17 words
A coating solution of claim 8, wherein nitrate ion is present in the amount of 200-1000 ppm.
Claim 13
Dependent Claim
33 words
A coating composition of claim 7, wherein the source of zirconium is selected from the group consisting of ammonium zirconyl carbonate, zirconium orthosulfate, zirconium oxynitrate, zirconium hydroxide, zirconium fluoride, and ammonium zirconyl fluoride.
Claim 14
Dependent Claim
15 words
A coating solution of claim 7, wherein the source of zirconium is ammonium zirconyl carbonate.
Claim 15
Independent Claim
85 words
A method for coating an aluminum substrate comprising the steps of: I. preparing a clean, washed and rinsed aluminum surface; II. contacting the aluminum surface for about 30 seconds with an acidic solution consisting essentially of 30-45 ppm zirconium ions, 75-125 ppm vegetable tannin, and 30-70 ppm fluoride ions, and excluding phosphate ion, said solution being maintained at a pH between 2.3 and 2.95; III. reacting said solution with the aluminum surface to produce an aluminum surface which is corrosion resistant and provides improved adhesion.
Claim 16
Independent Claim
85 words
A method for coating an aluminum substrate comprising the steps of: I. preparing a clean, washed and rinsed aluminum surface; II. contacting the aluminum surface for about 30 seconds with an acidic solution consisting essentially of 30-45 ppm zirconium ions, 75-125 ppm vegetable tannin, and 30-70 ppm fluoride ions, and excluding phosphate ion, said solution being maintained at a pH between 2.3 and 2.95; III. reacting said solution with the aluminum surface to produce an aluminum surface which is corrosion resistant and provides improved adhesion.
Claim 17
Dependent Claim
11 words
A method of claim 12, wherein said solution contains nitric acid.
Claim 18
Dependent Claim
17 words
A method of claim 13, wherein the nitrate ion is present in the range of 200-1000 ppm.
Claim 19
Dependent Claim
16 words
A method of claim 12, wherein the temperature of the coating solution is about 110°-130° F.
Claim 20
Dependent Claim
16 words
A method of claim 12, wherein the aluminum substrate is contacted with the solution by immersion.
Claim 21
Independent Claim
127 words
A method for coating aluminum can stock comprising the steps of: I. preparing a clean, washed and rinsed aluminum can; II. contacting the surface of the can for about 30 seconds at a temperature between 100° and 130° F. with an acidic solution of a ternary composition consisting essentially of zirconium ions, fluoride ions, and soluble vegetable tannin, and excluding phosphate ion, said solution being maintained at a pH between 2.3 and 2.95 and wherein the concentration of zirconium is between 0.014 and 0.096 grams/liter, the fluoride concentration is between 0.020 and 0.140 grams/liter, and the tannin concentration is between 0.060 and 0.240 grams/liter; III. reacting said solution with the can surface to produce a coating on the can which is corrosion resistant and provides improved adhesion.
Claim 22
Independent Claim
127 words
A method for coating aluminum can stock comprising the steps of: I. preparing a clean, washed and rinsed aluminum can; II. contacting the surface of the can for about 30 seconds at a temperature between 100° and 130° F. with an acidic solution of a ternary composition consisting essentially of zirconium ions, fluoride ions, and soluble vegetable tannin, and excluding phosphate ion, said solution being maintained at a pH between 2.3 and 2.95 and wherein the concentration of zirconium is between 0.014 and 0.096 grams/liter, the fluoride concentration is between 0.020 and 0.140 grams/liter, and the tannin concentration is between 0.060 and 0.240 grams/liter; III. reacting said solution with the can surface to produce a coating on the can which is corrosion resistant and provides improved adhesion.
Claim 23
Dependent Claim
13 words
A method of claim 17, including an additional step of pasteurizing the can.
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) | 1984-07-06 | 1985-01-05 | 1985-07-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-07-06 | 1989-01-05 | 1989-07-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-07-06 | 1993-01-05 | 1993-07-07 | $7700.00 | Window Closed / Lapsed |