US4595424A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of forming phosphate coating on zinc
Assignee: Henkel Corp
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Filing: 1985-08-26
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Granted: 1986-06-17
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Expires: 2005-08-26
Abstract
Abstract Disclosed is an improved method for coating a zinc surface comprising treating said surface with an aqueous, acidic solution containing: (a) about 0.5 to about 4 percent phosphate ion; (b) an ion selected from the group consisting of zinc ions, manganese ions, and mixtures thereof, said ions being present at a level sufficient to form dihydrogen phosphate with substantially all of said phosphate ions; and (c) about 0.01 to about 1 percent complex fluoride ions; wherein the weight:weight ratio of complex fluoride ions:chloride ions in said solution is at a value of about 8:1 or greater. It is preferred that the ratio complex of fluoride ion to chloride ion (F - :Cl - ) in said solution to be maintained at a value of greater than about 8:1, preferably greater than about 10:1, and more preferably greater than about 14:1. The select weight:weight complex fluoride:chloride ratio substantially eliminates the abnormal crystal growth frequently found in treated surfaces while at the same time reduces the need for excess fluoride.
Inventors
- 👤 Kenneth J. Hacias
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 01:37
CPC Classifications
C; C23; C23C; C23C22/00; C23C22/05; C23C22/06; C23C22/34; C23C22/36; C23C22/362
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
101 words
An improved method for coating a zinc surface comprising treating said surface with an aqueous, acidic solution containing: (a) about 0.5 to about 4 percent phosphate ion; (b) an ion selected from the group consisting of zinc ions, manganese ions, and mixtures thereof, said ions being present at a level sufficient to form dihydrogen phosphate with substantially all of said phosphate ions; and (c) about 0.01 to about 1 percent complex fluoride ions; and (d) measuring the chloride ion concentration and maintaining the weight:weight ratio of complex fluoride ions:chloride ions in said solution at a value of about 8:1 or greater.
Claim 2
Dependent Claim
101 words
An improved method for coating a zinc surface comprising treating said surface with an aqueous, acidic solution containing: (a) about 0.5 to about 4 percent phosphate ion; (b) an ion selected from the group consisting of zinc ions, manganese ions, and mixtures thereof, said ions being present at a level sufficient to form dihydrogen phosphate with substantially all of said phosphate ions; and (c) about 0.01 to about 1 percent complex fluoride ions; and (d) measuring the chloride ion concentration and maintaining the weight:weight ratio of complex fluoride ions:chloride ions in said solution at a value of about 8:1 or greater.
Claim 3
Dependent Claim
19 words
A method according to claim 1, wherein said solution additionally contains about 0.025 to about 2 percent nitrate ion.
Claim 4
Dependent Claim
33 words
A method according to claim 1 wherein said solution additionally contains about 0.01 to about 1 percent of an ion selected from the group consisting of cobalt ions, nickel ions, and mixtures thereof.
Claim 5
Dependent Claim
19 words
A method according to claim 1, wherein the ratio is maintained at a value of about 10:1 or greater.
Claim 6
Dependent Claim
19 words
A method according to claim 4 wherein the ratio is maintained at a value of about 14:1 or greater.
Claim 7
Dependent Claim
22 words
A method according to claim 1 wherein the phosphate ion is present at a level of about 0.5 to about 2.5 percent.
Claim 8
Dependent Claim
22 words
A method according to claim 4 wherein the phosphate ion is present at a level of about 0.5 to about 2.0 percent.
Claim 9
Dependent Claim
22 words
A method according to claim 2 wherein the nitrate ion is present at a level of about 0.05 to about 1 percent.
Claim 10
Dependent Claim
21 words
A method according to claim 1 wherein the chloride ion is present at a level of less than about 0.0050 percent.
Claim 11
Dependent Claim
21 words
A method according to claim 9 wherein the chloride ion is present at a level of less than about 0.0020 percent.
Claim 12
Independent Claim
131 words
A method for coating a zinc surface comprising treating said surface with an aqueous acidic solution containing: (a) about 0.5 to about 4 percent phosphate ion; (b) about 0.025 to about 2 percent nitrate ion; (c) an ion selected from the group consisting of zinc ions, manganese ions, and mixtures thereof, said ions being present at a level sufficient to form dihydrogen phosphate with substantially all of said phosphate ions; and (d) about 0.01 to about 1 percent of an ion selected from the group consisting of cobalt ions, nickel ions, and mixtures thereof; wherein said solution contains less than about 0.0050 percent chloride ion; and (e) measuring the chloride ion concentration and maintaining the ratio of fluoride ions:chloride ions in said solution at a value of about 8:1 or greater.
Claim 13
Independent Claim
131 words
A method for coating a zinc surface comprising treating said surface with an aqueous acidic solution containing: (a) about 0.5 to about 4 percent phosphate ion; (b) about 0.025 to about 2 percent nitrate ion; (c) an ion selected from the group consisting of zinc ions, manganese ions, and mixtures thereof, said ions being present at a level sufficient to form dihydrogen phosphate with substantially all of said phosphate ions; and (d) about 0.01 to about 1 percent of an ion selected from the group consisting of cobalt ions, nickel ions, and mixtures thereof; wherein said solution contains less than about 0.0050 percent chloride ion; and (e) measuring the chloride ion concentration and maintaining the ratio of fluoride ions:chloride ions in said solution at a value of about 8:1 or greater.
Claim 14
Dependent Claim
19 words
A method according to claim 11 wherein the ratio is maintained at a value of about 10:1 or greater.
Claim 15
Dependent Claim
19 words
A method according to claim 12 wherein the ratio is maintained at a value of about 14:1 or greater.
Claim 16
Dependent Claim
22 words
A method according to claim 11 wherein the phosphate ion is present at a level of about 0.5 to about 2.5 percent.
Claim 17
Dependent Claim
16 words
A method according to claim 1 wherein all pre-treatment steps are substantially free of chloride ions.
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| 3.5 Years (Year 4) | 1989-06-16 | 1989-12-16 | 1990-06-17 | $2000.00 | Window Closed / Lapsed |
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