Patent US2837449A successfully refreshed from Google Patents.
US2837449A
Expired / Lapsed
US
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Composition of matter for and process of producing phosphate layers on iron surfaces
Assignee: Henkel AG and Co KGaA
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Filing: 1953-08-11
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Granted: 1958-06-03
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Expires: 1973-08-11
Abstract
No abstract record available.
Inventors
- 👤 Blaser Bruno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:23
CPC Classifications
C; C23; C23C; C23C22/00; C23C22/05; C23C22/06; C23C22/07; C23C22/08
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
60 words
IN A PROCESS OF PRODUCING PHOSPHATE LAYERS ON IRON SURFACES, THE STEP COMPRISING IMMERSING IRON ARTICLES IN AN AQUEOUS PHOSPHATIZING SOLUTION CONSISTING ESSENTIALLY OF THE ADDITION PRODUCT OF PHOSPHORIC ACID AND AN AMIDE OF A LOW MOLECULAR CARBOXYLIC ACID CONTAINING FROM 1 TO 3 CARBON ATOMS TO CAUSE FORMATION OF A PHOSPHATE LAYER ON THE SURFACE OF SAID IRON ARTICLE.
Claim 2
Dependent Claim
60 words
IN A PROCESS OF PRODUCING PHOSPHATE LAYERS ON IRON SURFACES, THE STEP COMPRISING IMMERSING IRON ARTICLES IN AN AQUEOUS PHOSPHATIZING SOLUTION CONSISTING ESSENTIALLY OF THE ADDITION PRODUCT OF PHOSPHORIC ACID AND AN AMIDE OF A LOW MOLECULAR CARBOXYLIC ACID CONTAINING FROM 1 TO 3 CARBON ATOMS TO CAUSE FORMATION OF A PHOSPHATE LAYER ON THE SURFACE OF SAID IRON ARTICLE.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-06-02 | 1961-12-02 | 1962-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-06-02 | 1965-12-02 | 1966-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-06-02 | 1969-12-02 | 1970-06-03 | $7700.00 | Window Closed / Lapsed |