US4057440A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Scale reducer for zinc phosphating solutions
Assignee: Arkema Inc
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Filing: 1976-01-29
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Granted: 1977-11-08
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Expires: 1996-01-29
Abstract
Abstract The hard rock-like scale formed on zinc phosphating equipment is rendered soft and dispersible by adding a scale-reducing amount of dialkyl triamine pentakis methylene phosphonic acid or its alkaline salt in the zinc phosphating solution.
Inventors
- 👤 Thomas Clifford Atkiss
- 👤 William Elgin Keen, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 03:58
CPC Classifications
C; C23; C23C; C23C22/00; C23C22/05; C23C22/06; C23C22/07; C23C22/08; C23C22/12
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
63 words
In the process of phosphating iron, steel, galvanized steel and aluminum with an aqueous acidic zinc phosphating solution the improvement comprising adding a scale-reducing amount of dialkyl triamine pentakis methylene phosphonic acid or its alkaline salt in which the alkyl group ranges from C 2 to C 8 carbons and the salt is selected from the group consisting of sodium, potassium and ammonium.
Claim 2
Dependent Claim
63 words
In the process of phosphating iron, steel, galvanized steel and aluminum with an aqueous acidic zinc phosphating solution the improvement comprising adding a scale-reducing amount of dialkyl triamine pentakis methylene phosphonic acid or its alkaline salt in which the alkyl group ranges from C 2 to C 8 carbons and the salt is selected from the group consisting of sodium, potassium and ammonium.
Claim 3
Dependent Claim
27 words
The process of claim 1 in which the scale-reducing additive is present in the phosphating solution at a concentration of at least about 0.05 grams per liter.
Claim 4
Dependent Claim
67 words
In an aqueous acidic concentrate of zinc and phosphate ions for dilution with water to prepare a zinc phosphating solution the improvement comprising the addition of a scale-reducing amount of dialkyl triamine pentakis methylene phosphonic acid or its alkaline salt in which the alkyl group ranges from C 2 to C 8 carbons and the salt is selected from the group consisting of sodium, potassium and ammonium.
Claim 5
Dependent Claim
67 words
In an aqueous acidic concentrate of zinc and phosphate ions for dilution with water to prepare a zinc phosphating solution the improvement comprising the addition of a scale-reducing amount of dialkyl triamine pentakis methylene phosphonic acid or its alkaline salt in which the alkyl group ranges from C 2 to C 8 carbons and the salt is selected from the group consisting of sodium, potassium and ammonium.
Claim 6
Dependent Claim
25 words
The aqueous acidic concentrate of claim 3 in which the scale-reducer additive is present at a concentration of at least about 0.7 grams per liter.
References Cited (Backward Citations)
US3336221A
Cited
US3459600A
Cited
US3816517A
Cited
US3738937A
Cited
US3778377A
Cited
US4000012A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-11-07 | 1981-05-09 | 1981-11-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-11-07 | 1985-05-09 | 1985-11-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-11-07 | 1989-05-09 | 1989-11-08 | $7700.00 | Window Closed / Lapsed |