US4183758A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Zinc chromium chromate pigment
Assignee: Individual
•
Filing: 1978-03-06
•
Granted: 1980-01-15
•
Expires: 1998-03-06
Abstract
Abstract Zinc oxide is interacted with an aqueous solution containing a chromium chromate complex obtained through partial reduction of an aqueous solution of chromic acid with an organic reducing agent. The resulting product is dried and the residual solid ground to suitable size for use as a pigment.
Inventors
- 👤 Louis Schiffman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 21:24
CPC Classifications
C; C09; C09D; C09D5/00; C09D5/08; C09D5/082; C09D5/084; C01; C01G; C01G37/00; C09C; C09C1/00; C09C1/04; C09C1/08; C01P; C01P2004/00; C01P2004/80
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
41 words
A zinc chromium chromate corrosion inhibiting pigment wherein the mol ratio of zinc oxide to total chromium oxides is about in the range of 5:1 to 1:3 and 5 to 70% of the total chromium content is present in trivalent state.
Claim 2
Dependent Claim
41 words
A zinc chromium chromate corrosion inhibiting pigment wherein the mol ratio of zinc oxide to total chromium oxides is about in the range of 5:1 to 1:3 and 5 to 70% of the total chromium content is present in trivalent state.
Claim 3
Dependent Claim
26 words
A zinc chromium chromate corrosion inhibiting pigment as defined in claim 1 wherein the mol ratio of zinc oxide to total chromium oxides is about 1:1.
Claim 4
Dependent Claim
25 words
A zinc chromium chromate corrosion inhibiting pigment as defined in claim 2 wherein 25 to 65% of the total chromium is present in trivalent state.
Claim 5
Dependent Claim
24 words
A zinc chromium chromate corrosion inhibiting pigment as defined in claim 2 wherein approximately 42% of the total chromium is present in trivalent state.
Claim 6
Dependent Claim
25 words
A zinc chromium chromate corrosion inhibiting pigment as defined in claim 1 wherein 25 to 65% of the total chromium is present in trivalent state.
Claim 7
Independent Claim
47 words
The method of preparing a corrosion-inhibiting pigment powder comprising a complex of zinc and chromium chromate which method comprises interacting zinc oxide with a preformed complex of trivalent and hexavalent chromium, in aqueous solution, drying the obtained reaction product and thereafter grinding the same to a powder.
Claim 8
Independent Claim
47 words
The method of preparing a corrosion-inhibiting pigment powder comprising a complex of zinc and chromium chromate which method comprises interacting zinc oxide with a preformed complex of trivalent and hexavalent chromium, in aqueous solution, drying the obtained reaction product and thereafter grinding the same to a powder.
Claim 9
Dependent Claim
39 words
The method as defined in claim 6 wherein said chromium chromate complex solution is one obtained by partially reducing chromium trioxide in aqueous solution with a water soluble oxidizable organic compound having an active hydroxyl, aldehyde or carboxyl group.
Claim 10
Dependent Claim
13 words
The method as defined in claim 7 wherein said organic compound is formaldehyde.
Claim 11
Dependent Claim
13 words
The method as defined in claim 7 wherein said organic compound is methanol.
Claim 12
Dependent Claim
13 words
The method as defined in claim 7 wherein said organic compound is furfural.
References Cited (Backward Citations)
US2387528A
Cited
US3477881A
Cited
US3501352A
Cited
US3472681A
Cited
US3879523A
Cited
US3909313A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-01-14 | 1983-07-16 | 1984-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-01-14 | 1987-07-16 | 1988-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-01-14 | 1991-07-16 | 1992-01-15 | $7700.00 | Window Closed / Lapsed |