US4867795A
Expired / Lapsed
US
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Plateletlike pigments based on iron oxide
Assignee: BASF SE
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Filing: 1988-03-08
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Granted: 1989-09-19
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Expires: 2008-03-08
Abstract
Abstract Plateletlike pigments based on iron oxide and having a spinel structure of the composition: MnuAlvFe[3-(u+v)]-zO4-z, where u is from 0.01-0.09, v is from 0-0.3 and z is from 0-1. The pigments can be used for producing decorative coatings, in particular in paints, plastics, prints and cosmetics, for producing electromagnetic screens, as substrates for coatings and as pigments having magnetic properties.
Inventors
- 👤 Werner Ostertag
- 👤 Norbert Mronga
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 05:50
CPC Classifications
C; C09; C09C; C09C1/00; C09C1/40; C01; C01G; C01G49/00; C01G49/0018; C01G49/0072; C01G49/009; C09C1/0015; C09C1/0018; C09C1/22; C09C1/24; C09C1/245; C09D; C09D5/00; C09D5/36; G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/706; G11B5/70626; G11B5/70642; G11B5/70678; C01P; C01P2002/00; C01P2002/30; C01P2002/32; C01P2004/00; C01P2004/20; C01P2004/54; C01P2004/60; C01P2004/61; C01P2006/00; C01P2006/12; C01P2006/42; C01P2006/60; C01P2006/62; C01P2006/65; C01P2006/66
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
33 words
A plateletlike pigment based on iron oxide and having a spinel structure of the composition: Mn.sub.u Al.sub.v Fe.sub.[3-(u+v)]-z O.sub.4-z, where u is from 0.01-0.09, v is from 0-0.3 and z is from 0-1.
Claim 2
Dependent Claim
33 words
A plateletlike pigment based on iron oxide and having a spinel structure of the composition: Mn.sub.u Al.sub.v Fe.sub.[3-(u+v)]-z O.sub.4-z, where u is from 0.01-0.09, v is from 0-0.3 and z is from 0-1.
Claim 3
Dependent Claim
57 words
A plateletlike two-phase pigment, wherein the surfaces have a spinel structure of the composition: Mn.sub.u Al.sub.v Fe.sub.[3-(u+v)]-z O.sub.4-z where u is from 0.01-0.09, v is from 0-0.3 and z is from 0-1, and the core has a structure of hematite of the composition Mn.sub.x Al.sub.y Fe.sub.2-(x+y) O.sub.3 where x is from 0.01-0.06 and y is from 0-0.2.
Claim 4
Dependent Claim
57 words
A plateletlike two-phase pigment, wherein the surfaces have a spinel structure of the composition: Mn.sub.u Al.sub.v Fe.sub.[3-(u+v)]-z O.sub.4-z where u is from 0.01-0.09, v is from 0-0.3 and z is from 0-1, and the core has a structure of hematite of the composition Mn.sub.x Al.sub.y Fe.sub.2-(x+y) O.sub.3 where x is from 0.01-0.06 and y is from 0-0.2.
Claim 5
Dependent Claim
58 words
A process for producing a pigment as claimed in claim 1, which comprises treating a plateletlike starting pigment having a hematite structure of the composition Mn x Al y Fe 2- (x+y) O 3 , where x is 0.01-0.06 and y is 0-0.2, at elevated temperatures with a reducing gas until the starting pigment has been fully reduced.
Claim 6
Dependent Claim
25 words
A process as claimed in claim 3, wherein the reducing gas used is selected from the group consisting of hydrogen, ammonium, carbon monoxide and methane.
Claim 7
Dependent Claim
14 words
A process as claimed in claim 3, wherein the reducing gas contains water vapor.
Claim 8
Dependent Claim
26 words
A process as claimed in claim 5, wherein the reducing gas contains water vapor in an amount corresponding to saturation at from 20° to 85° C.
Claim 9
Dependent Claim
23 words
A process as claimed in claim 3, wherein the treatment with the reducing gas is carried out at from 200° to 1,200° C.
Claim 10
Dependent Claim
33 words
A process as claimed in claim 3, wherein after the reduction the product having a spinel structure of the composition Mn u Al v Fe.sub.(3-[u+v]) O 4 is oxidized with an oxygen-containing gas.
Claim 11
Dependent Claim
17 words
A process as claimed in claim 8, wherein the oxygen-containing gas contains <20% by volume of oxygen.
Claim 12
Dependent Claim
20 words
A process as claimed in claim 8 or 9, wherein the oxidation is carried at from 150° to 400° C.
Claim 13
Dependent Claim
61 words
A process for producing a pigment as claimed in claim 2, which comprises treating a plateletlike starting pigment having a hematite structure of the composition Mn x Al y Fe 2- (x+y) O 3 , where x is 0.01-0.06 and y is 0-0.2, at elevated temperatures with a reducing gas and discontinuing the treatment before the pigment has been fully reduced.
Claim 14
Dependent Claim
25 words
A process as claimed in claim 11, wherein the reducing gas used is selected from the group consisting of hydrogen, ammonia, carbon monoxide and methane.
Claim 15
Dependent Claim
14 words
A process as claimed in claim 11, wherein the reducing gas contains water vapor.
Claim 16
Dependent Claim
26 words
A process as claimed in claim 13, wherein the reducing gas contains water vapor in an amount corresponding to saturation at from 20° to 85° C.
Claim 17
Dependent Claim
23 words
A process as claimed in claim 11, wherein the treatment with the reducing gas is carried out at from 200° to 1,200° C.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-09-18 | 1993-03-20 | 1993-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-18 | 1997-03-20 | 1997-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-18 | 2001-03-20 | 2001-09-19 | $7700.00 | Window Closed / Lapsed |