Patent US2863793A successfully refreshed from Google Patents.
US2863793A
Expired / Lapsed
US
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Method of maintaining the efficiency of phosphate coating baths used at room temperature
Assignee: Montedison SpA
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Filing: 1956-04-17
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Granted: 1958-12-09
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Expires: 1976-04-17
Abstract
No abstract record available.
Inventors
- 👤 Cerma Paolo De
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 02:01
CPC Classifications
C; C23; C23C; C23C22/00; C23C22/05; C23C22/06; C23C22/07; C23C22/08; C23C22/12; C23C22/13
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
149 words
THE METHOD OF MAINTAINING THE EFFICIENCY OF PHOSPHATE COATING BATHS USED TO COAT A METALLIC SURFACE IN THE COLD, COMPRISING PREPARING, AS COATING BATH, AN AQUEOUS SOLUTION OF ZINC PHOSPHATE AND AT LEAST ONE NITRATE SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL NITRATES AND ZINC NITRATE, AND DURING THE METAL COATING PROCESS MAINTAINING IN SAID COATING BATH A P235/NO3 RATIO RANGING FROM ABOUT 1:2.5 TO ABOUT 1:1 BY REPLENISHING THE COATING BATH DEPLETED IN THE COATING OPERATIONS WITH A FEED LIQUOR COMPRISING AN AQUEOUS SOLUTION OF ZINC PHOSPHATE, AT LEAST ONE NITRATE SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL NITRATES AND ZINC NITRATE THE P2O5/NO3 RATIO OF THE FEED LIQUOR BEING WITHIN A RANGE FROM ABOUT 1:1 TO ABOUT 1:0.5, AND ALSO ADDING SODIUM NITRITE AS OXIDIZING AGENT IN AN AMOUNT NOT MORE THAN ABOUT ONE TENTH OF THE WEIGHT OF NO3 CONTAINED IN THE FEED LIQUOR.
Claim 2
Independent Claim
149 words
THE METHOD OF MAINTAINING THE EFFICIENCY OF PHOSPHATE COATING BATHS USED TO COAT A METALLIC SURFACE IN THE COLD, COMPRISING PREPARING, AS COATING BATH, AN AQUEOUS SOLUTION OF ZINC PHOSPHATE AND AT LEAST ONE NITRATE SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL NITRATES AND ZINC NITRATE, AND DURING THE METAL COATING PROCESS MAINTAINING IN SAID COATING BATH A P235/NO3 RATIO RANGING FROM ABOUT 1:2.5 TO ABOUT 1:1 BY REPLENISHING THE COATING BATH DEPLETED IN THE COATING OPERATIONS WITH A FEED LIQUOR COMPRISING AN AQUEOUS SOLUTION OF ZINC PHOSPHATE, AT LEAST ONE NITRATE SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL NITRATES AND ZINC NITRATE THE P2O5/NO3 RATIO OF THE FEED LIQUOR BEING WITHIN A RANGE FROM ABOUT 1:1 TO ABOUT 1:0.5, AND ALSO ADDING SODIUM NITRITE AS OXIDIZING AGENT IN AN AMOUNT NOT MORE THAN ABOUT ONE TENTH OF THE WEIGHT OF NO3 CONTAINED IN THE FEED LIQUOR.
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) | 1961-12-08 | 1962-06-09 | 1962-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-12-08 | 1966-06-09 | 1966-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-12-08 | 1970-06-09 | 1970-12-09 | $7700.00 | Window Closed / Lapsed |