US3447973A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Protective treatment for magnesium
Assignee: Dow Chemical Co
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Filing: 1966-08-17
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Granted: 1969-06-03
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Expires: 1986-08-17
Abstract
No abstract record available.
Inventors
- 👤 Herbert K De Long
- 👤 Donald E Ritzema
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 05:11
CPC Classifications
C; C23; C23C; C23C22/00; C23C22/73; C23C22/74
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
146 words
A PROCESS FOR PROVIDING A PROTECTIVE SURFACE COATING ON MAGNESIUM WHICH COMPRISES: (A) CONTACTING A MARGNESIUM ARTICLE AT A TEMPERATURE OF FROM ABOUT 70*F. TO ABOUT 220*F. FOR A PERIOD OF FROM ABOUT 1 TO ABOUT 60 MINUTES WITH AN AQUEOUS ALKALINE SOLUTION CONTAINING PHOSPHATE AND CHROMATE ION SOURCE MATERIALS, SAID SOLUTION COMPRISING AN ALKALI METAL CAUSTIC, EXPRESSED AS NAOH, OF FROM ABOUT 5 TO ABOUT 300 GRAMS/LITER, ALKALI METAL PHOSPHATE, EXPRESSED AS TRISODIUM PHOSPAHTE DECHYDRATE, FROM ABOUT 1 TO ABOUT 60 GRAMS/LITER, AND AQUEOUS SOLUBLE CHROMATE ION SOURCE MATERIAL, EXPRESSED AS SODIUM CHROMATE TETRAHYDRATE, FROM ABOUT 1 TO ABOUT 50 GRAMS/LITER, (B) SEPARATING THE SO-TREATED ARTICLE FROM CONTACT WITH SAID SOLUTION, AND (C) HEATING THE SO-TREATED ARTICLE AT A TEMPERATURE OF FROM ABOUT 300 TO ABOUT 800*F. FOR A PERIOD OF FROM ABOUT 2 MINUTES TO ABOUT 8 HOURS OR MORE IN AN OXIDIZING ATMOSPHERE.
Claim 2
Dependent Claim
146 words
A PROCESS FOR PROVIDING A PROTECTIVE SURFACE COATING ON MAGNESIUM WHICH COMPRISES: (A) CONTACTING A MARGNESIUM ARTICLE AT A TEMPERATURE OF FROM ABOUT 70*F. TO ABOUT 220*F. FOR A PERIOD OF FROM ABOUT 1 TO ABOUT 60 MINUTES WITH AN AQUEOUS ALKALINE SOLUTION CONTAINING PHOSPHATE AND CHROMATE ION SOURCE MATERIALS, SAID SOLUTION COMPRISING AN ALKALI METAL CAUSTIC, EXPRESSED AS NAOH, OF FROM ABOUT 5 TO ABOUT 300 GRAMS/LITER, ALKALI METAL PHOSPHATE, EXPRESSED AS TRISODIUM PHOSPAHTE DECHYDRATE, FROM ABOUT 1 TO ABOUT 60 GRAMS/LITER, AND AQUEOUS SOLUBLE CHROMATE ION SOURCE MATERIAL, EXPRESSED AS SODIUM CHROMATE TETRAHYDRATE, FROM ABOUT 1 TO ABOUT 50 GRAMS/LITER, (B) SEPARATING THE SO-TREATED ARTICLE FROM CONTACT WITH SAID SOLUTION, AND (C) HEATING THE SO-TREATED ARTICLE AT A TEMPERATURE OF FROM ABOUT 300 TO ABOUT 800*F. FOR A PERIOD OF FROM ABOUT 2 MINUTES TO ABOUT 8 HOURS OR MORE IN AN OXIDIZING ATMOSPHERE.
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) | 1972-06-02 | 1972-12-02 | 1973-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-06-02 | 1976-12-02 | 1977-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-06-02 | 1980-12-02 | 1981-06-03 | $7700.00 | Window Closed / Lapsed |