US4637838A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for phosphating metals
Assignee: GEA Group AG
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Filing: 1985-03-05
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Granted: 1987-01-20
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Expires: 2005-03-05
Abstract
Abstract The quality of coatings in a low zinc phosphating process is improved by including an activator of formate, nitrilotriacetate, trichloroacetate or ethylenediamenetetraacetate to produce more uniform coatings particularly desirable in advance of electrocoating.
Inventors
- 👤 Werner Rausch
- 👤 Gerhard Mueller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 05:31
CPC Classifications
C; C23; C23C; C23C22/00; C23C22/05; C23C22/06; C23C22/07; C23C22/23; C23C22/08; C23C22/12; C23C22/17; C23C22/34; C23C22/36; C23C22/362
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
108 words
A process for phosphating metals, in particular steel and galvanized steel, by a spray method using an aqueous acidic phosphating solution containing an accelerator, zinc, wherein the metal surface is brought into contact with a phosphating solution which contains 0.2 to 0.5 g/l of Zn ++ 8 to 20 g/l of P 2 O 5 at least one accelerator selected from the group consisting of: 0.5 to 0.2 g/l of NO 2 and 0.1 to 1 g/l of nitrobenzenesulfonate and at least one activator from the group consisting formate, nitrilotriacetate, trichloroacetate and ethylenediaminetetraacetate whereby a uniform coating in the range of 0.8 to 2.5 g/m 2 is obtained.
Claim 2
Dependent Claim
108 words
A process for phosphating metals, in particular steel and galvanized steel, by a spray method using an aqueous acidic phosphating solution containing an accelerator, zinc, wherein the metal surface is brought into contact with a phosphating solution which contains 0.2 to 0.5 g/l of Zn ++ 8 to 20 g/l of P 2 O 5 at least one accelerator selected from the group consisting of: 0.5 to 0.2 g/l of NO 2 and 0.1 to 1 g/l of nitrobenzenesulfonate and at least one activator from the group consisting formate, nitrilotriacetate, trichloroacetate and ethylenediaminetetraacetate whereby a uniform coating in the range of 0.8 to 2.5 g/m 2 is obtained.
Claim 3
Dependent Claim
38 words
The process of claim 1, wherein the metal surface is brought into contact with a phosphating solution which contains at least one further additive from the group consisting of fluoride, hexafluorosilicate, tetrafluoroborate, glycolate, citrate, tartrate and condensed phosphate.
Claim 4
Dependent Claim
53 words
The process of claim 1, wherein the metal surface is brought into contact with a phosphating solution wherein the at least one activator is present in an amount of 5 to 15 g/l for formate 0.3 to 3 g/l for nitrilotriacetate 2 to 15 g/l for trichloroacetate 0.1 to 3 g/l for ethylenediaminetetraacetate.
Claim 5
Dependent Claim
60 words
The process of claim 2 containing at least one additive selected from the group consisting of: 0.5 to 3 g/l for fluoride 1 to 5 g/l for hexafluorosilicate 3 to 10 g/l for tetrafluoroborate 0.3 to 5 g/l for glycolate 0.01 to 0.5 g/l for citrate 0.03 to 0.8 g/l for tartrate and 0.03 to 0.3 g/l for condensed phosphate.
Claim 6
Dependent Claim
14 words
The process of claim 1 wherein the phosphated surface is subsequently subjected to electrocoating.
Claim 7
Dependent Claim
18 words
The process of claim 1 wherein the phosphated solution additionally contains up to 1 g/l of nickel ion.
References Cited (Backward Citations)
US2743204A
Cited
SU800240A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-01-19 | 1990-07-21 | 1991-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-01-19 | 1994-07-21 | 1995-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-01-19 | 1998-07-21 | 1999-01-20 | $7700.00 | Window Closed / Lapsed |