US5154769A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for production of black manganese/iron oxide pigment
Assignee: Lanxess Deutschland GmbH
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Filing: 1991-01-22
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Granted: 1992-10-13
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Expires: 2011-01-22
Abstract
Abstract A black manganese/iron oxide pigment having a spinel structure and having the composition Mn x Fe 3-x O 4 wherein x has a value from 0.1 to 0.9, is prepared by the steps: a) oxidizing iron(II) salts or mixtures of iron(II) salts and manganese(II) salts, in solution or after reaction with alkaline precipitants, with manganese dioxide or other compounds containing manganese in high valency, b) additionally oxidizing the salts of (a) to establish an Fe(III) content therein with another oxidizing agent, and c) filtering, washing, drying and grinding the pigment; and the pigment is useful for pigmenting building materials to a black color.
Inventors
- 👤 Peter Kuske
- 👤 Gunter Buxbaum
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 07:32
CPC Classifications
C; C09; C09C; C09C1/00; C09C1/22; C01; C01G; C01G49/00; C04; C04B; C04B14/00; C04B14/02; C04B14/30; C01P; C01P2002/00; C01P2002/30; C01P2002/32; C04B2103/00; C04B2103/54
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
123 words
A process for the production of a black manganese/iron oxide pigment having a spinel structure, having the composition Mn x Fe 3-x O 4 wherein x has a value from 0.1 to 0.9, having pigment particle diameters of 0.1 to 1 μm and having specific surface area of 3 to 15 m 2 /g and consisting essentially of mixed crystals of spinel structure which comprises: a) oxidizing iron(II) salts or mixtures of iron(II) salts and manganese (II) salts, in solution or after reaction with alkaline precipitants, with manganese dioxide or other compounds containing manganese in high valency, b) additionally oxidizing the salts of (a) to establish an fe(III) content therein with another oxidizing agent, and c) filtering, washing, drying and grinding the pigment.
Claim 2
Dependent Claim
123 words
A process for the production of a black manganese/iron oxide pigment having a spinel structure, having the composition Mn x Fe 3-x O 4 wherein x has a value from 0.1 to 0.9, having pigment particle diameters of 0.1 to 1 μm and having specific surface area of 3 to 15 m 2 /g and consisting essentially of mixed crystals of spinel structure which comprises: a) oxidizing iron(II) salts or mixtures of iron(II) salts and manganese (II) salts, in solution or after reaction with alkaline precipitants, with manganese dioxide or other compounds containing manganese in high valency, b) additionally oxidizing the salts of (a) to establish an fe(III) content therein with another oxidizing agent, and c) filtering, washing, drying and grinding the pigment.
Claim 3
Dependent Claim
17 words
A process as claimed in claim 1 wherein the oxidizing agent in step b) is oxygen-containing gas.
Claim 4
Dependent Claim
23 words
A process as claimed in claim 1 wherein the oxidation is carried out at temperatures between room temperature and the solution boiling point.
Claim 5
Dependent Claim
20 words
A process as claimed in claim 3 wherein the oxidation temperature is from 80° C. to the solution boiling temperature.
Claim 6
Dependent Claim
14 words
A process as claimed in claim 1 wherein manganese dioxide is the oxidizing agent.
Claim 7
Dependent Claim
34 words
A process as claimed in claim 1 wherein the oxidizing agent is less reactive oxides of manganese with valency from 3 to 7 used for the production of black pigments with a bluish tinge.
Claim 8
Dependent Claim
39 words
A process as claimed in claim 1 wherein the oxidizing agent is manganese dioxide ore or waste manganese dioxides from chemical processes and the iron(II) salts are iron salts from the production of TiO 2 or from pickling plants.
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) | 1995-10-13 | 1996-04-13 | 1996-10-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-10-13 | 2000-04-13 | 2000-10-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-10-13 | 2004-04-13 | 2004-10-13 | $7700.00 | Window Closed / Lapsed |