Patent US4400289A successfully refreshed from Google Patents.
US4400289A
Expired / Lapsed
US
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Composition and process for pickling and removing rust from metal
Assignee: GEA Group AG
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Filing: 1982-02-05
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Granted: 1983-08-23
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Expires: 2002-02-05
Abstract
Abstract A pickling and rust-removing paste composition suitable for cleaning metal surfaces, including surfaces of steel and aluminum. The composition contains fluoride ions and a mixture of calcium compounds and tervalent iron and/or aluminum compounds and has an acidity corresponding to at least 10% by weight of free acid, calculated at 100% HF. The composition also most preferably contains at least one anion selected from nitrate, sulfate, phosphate and chloride and has an acidity corresponding to from about 15 to 30% by weight of free acid, calculated as 100% HF. The composition is applied to that portion of the metal surface, such as steel or aluminum, to be treated and is retained in contact with the surface for a period of time sufficient to effect the desired pickling and/or removal of rust on the surface.
Inventors
- 👤 Joachim Geldner
- 👤 Josef Rones
- 👤 Horst Danzel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:56
CPC Classifications
C; C23; C23G; C23G1/00; C23G1/02; C23G1/025
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
44 words
A pickling and rust removing composition for cleaning metal surfaces which comprises fluoride ions, a mixture of calcium compounds and tervalent iron and/or aluminum compounds and which has an acidity corresponding to at least 10% by weight of free acid, calculated as 100% HF.
Claim 2
Dependent Claim
44 words
A pickling and rust removing composition for cleaning metal surfaces which comprises fluoride ions, a mixture of calcium compounds and tervalent iron and/or aluminum compounds and which has an acidity corresponding to at least 10% by weight of free acid, calculated as 100% HF.
Claim 3
Dependent Claim
58 words
The composition as claimed in claim 1 in which the fluoride ions are present in an amount of at least about 5% by weight of the composition and the mixture of calcium compounds and tervalent iron and/or aluminum compounds is present in an amount from about 1 to 10% by weight of the composition, calculated as the cation.
Claim 4
Dependent Claim
46 words
The composition as claimed in claim 2 wherein the fluoride ions are present in an amount of from about 10 to 15% by weight of the composition and the mixture is present in an amount of from about 1 to 7% by weight of the composition.
Claim 5
Dependent Claim
28 words
The composition as claimed in claim 2 wherein the mole ratio of calcium to tervalent iron and/or aluminum in the composition is from about 3:1 to about 1:3.
Claim 6
Dependent Claim
21 words
The composition as claimed in claim 4 wherein the mole ratio of calcium to tervalent iron and/or aluminum is about 1:1.
Claim 7
Dependent Claim
22 words
The composition as claimed in claim 1 wherein there is present at least one anion selected from nitrate, sulfate, phosphate and chloride.
Claim 8
Dependent Claim
33 words
The composition as claimed in claim 6 wherein the mole ratio of fluoride ions to the total nitrate, sulfate, phosphate and chloride ions is within the range from about 3:1 to about 1:6.
Claim 9
Dependent Claim
31 words
The composition as claimed in claim 7 wherein the mole ratio of fluoride ions to the total of nitrate, sulfate, phosphate and chloride ions is from about 1:1 to about 1:4.
Claim 10
Dependent Claim
27 words
The composition as claimed in claim 6 wherein the acidity corresponds to from about 15 to about 30% by weight of free acid, calculated as 100% HF.
Claim 11
Dependent Claim
59 words
A process for pickling and/or cleaning metal surfaces which comprises applying to that portion of the surface that is to be cleaned a composition as claimed in claim 1, 2, 3, 4, 5, 6, 7, 8, or 9 and retaining the composition in contact with the metal surface for a period of time sufficient to effect the desired cleaning.
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) | 1986-08-22 | 1987-02-21 | 1987-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-22 | 1991-02-21 | 1991-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-22 | 1995-02-21 | 1995-08-23 | $7700.00 | Window Closed / Lapsed |