US3655418A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of pigments
Assignee: United Kingdom Atomic Energy Authority
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Filing: 1969-08-14
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Granted: 1972-04-11
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Expires: 1989-08-14
Abstract
Abstract A route for the production of a black pigment comprises making an aqueous solution of iron and manganese salts and reacting it with a base in the presence of a protective colloid to produce a granular precipitate. The colloid is preferably in the base but it may also be in the salt solution.
Inventors
- 👤 Clarence James Hardy
- 👤 Edward Sydney Lane
- 👤 Mervyn John Hannam
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:35
CPC Classifications
C; C09; C09C; C09C1/00; C09C1/22; C09C1/24; C01; C01P; C01P2002/00; C01P2002/50; C01P2002/52
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
25 words
The process of claim 1, wherein said aqueous salt solution is formed by dissolving manganese dioxide in dilute sulphuric acid and adding a ferric salt.
Claim 2
Dependent Claim
16 words
The process of claim 1, wherein the protective colloid is present in the aqueous base solution.
Claim 3
Dependent Claim
29 words
The process of claim 1, wherein the protective colloid is selected from the group of water-soluble organic compounds consisting of polyhydroxy compounds, polycarboxylic compounds, polycarbonamide compounds and polyamine compounds.
Claim 4
Dependent Claim
30 words
A process according to claim 4, wherein the colloid is selected from the group consisting of dextran, water-soluble cellulose derivatives, polyvinyl alcohol water-soluble starch derivatives, water-soluble methacrylate polymers, and gelatin.
Claim 5
Dependent Claim
17 words
The process of claim 1, wherein the precipitate is leached to reduce the proportion of unwanted ions.
Claim 6
Dependent Claim
16 words
The process of claim 1, wherein the precipitate is dried at a temperature below 100* C.
Claim 7
Dependent Claim
21 words
The process of claim 1, wherein the precipitate contains nitrate ions and is denitrated at a temperature of about 500* C.
Claim 8
Dependent Claim
15 words
The process of claim 1, wherein the precipitate is calcined in air at 750*-850* C.
Claim 9
Dependent Claim
21 words
The process of claim 1, wherein the ratio of iron to manganese is in the range 3:1 to 12:1 by weight.
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) | 1975-04-11 | 1975-10-11 | 1976-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-11 | 1979-10-11 | 1980-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-11 | 1983-10-11 | 1984-04-11 | $7700.00 | Window Closed / Lapsed |