US5525249A
Expired / Lapsed
US
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Magnetorheological fluids and methods of making thereof
Assignee: QED Technologies International LLC
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Filing: 1995-06-07
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Granted: 1996-06-11
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Expires: 2015-06-07
Abstract
Abstract A magnetorheological fluid composition comprising magnetosolid particles, magnetosoft particles, a stabilizer, and a carrying fluid comprising an aromatic alcohol, a vinyl ester, and an organic solvent or diluent carrier such as kerosene, in proportions sufficient to provide substantially no agglomeration or sedimentation of magnetic particles over temperatures of from about -50° to 120° C. The composition can be made by preparing a carrying fluid comprising a vinyl ester, an aromatic alcohol and kerosene; preparing a first carrying fluid composition comprising magnetosoft particles, a stabilizer and a first sample of the carrying fluid; preparing a second carrying fluid composition comprising magnetosolid particles and a second sample of the carrying fluid; and admixing the first carrying fluid composition and the second carrying fluid composition.
Inventors
- 👤 Viliyam Kordonsky
- 👤 Sveltana Demchuk
- 👤 Igor Prokhorov
- 👤 Zinovii Shulman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 09:58
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/44; H01F1/447; H01F1/442; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/12; Y10T428/12465; Y10T428/29; Y10T428/2982; Y10T428/2991
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
83 words
A magnetorheological fluid composition comprising: first particles comprising magnetosolid particles having their own magnetic moment comprising oxidized magnetite or chromium dioxide; second particles comprising magnetosoft particles being relatively larger in size than said magnetosolid particles and having adsorbed on their surface said magnetosolid particles; a stabilizer; and a carrying fluid comprising an aromatic alcohol, a vinyl ether, and an organic solvent, in proportions sufficient to provide substantially no agglomeration or sedimentation of magnetic particles over temperatures of from about -50° to 120° C.
Claim 2
Dependent Claim
83 words
A magnetorheological fluid composition comprising: first particles comprising magnetosolid particles having their own magnetic moment comprising oxidized magnetite or chromium dioxide; second particles comprising magnetosoft particles being relatively larger in size than said magnetosolid particles and having adsorbed on their surface said magnetosolid particles; a stabilizer; and a carrying fluid comprising an aromatic alcohol, a vinyl ether, and an organic solvent, in proportions sufficient to provide substantially no agglomeration or sedimentation of magnetic particles over temperatures of from about -50° to 120° C.
Claim 3
Dependent Claim
10 words
A composition according to claim 1 further comprising oleic acid.
Claim 4
Dependent Claim
20 words
A composition according to claim 1 wherein the magnetosolid particles are from about 0.1 to about 1.0 μm in diameter.
Claim 5
Dependent Claim
15 words
A composition according to claim 3 wherein the magnetosoft particles are made from carbonyl iron.
Claim 6
Dependent Claim
21 words
A composition according to claim 4 wherein the carbonyl iron particles are from about 1 to about 10 μm in diameter.
Claim 7
Dependent Claim
22 words
A composition according to claim 1 wherein the magnetosolid particles are needle-like and are adsorbed onto the surface of the magnetosoft particles.
Claim 8
Dependent Claim
24 words
A composition according to claim 1 wherein the aromatic alcohol is α-naphthol, the vinyl ether is polyvinyl-n-butyl ether and the organic solvent is kerosene.
Claim 9
Dependent Claim
12 words
A composition according to claim 1 wherein the stabilizer is silicon dioxide.
Claim 10
Dependent Claim
92 words
A magnetorheological fluid composition comprising: (a) 20 to 70 parts of magnetosoft carbonyl iron particles; (b) 0.5 to 20 parts of magnetosolid particles having their own magnetic moment selected from the group consisting of oxidized magnetite and chromium dioxide, the magnetosolid particles being adsorbed on the surface of the magnetosoft particles; (c) 4 to 9 parts of a silicon dioxide stabilizer; and (d) 25 to 55 parts of a carrying fluid comprising 5 to 10 weight percent polyvinyl-n-butyl ether, 0.01 to 1.0 weight percent α-naphthol and 90 to 95 weight percent kerosene.
Claim 11
Dependent Claim
92 words
A magnetorheological fluid composition comprising: (a) 20 to 70 parts of magnetosoft carbonyl iron particles; (b) 0.5 to 20 parts of magnetosolid particles having their own magnetic moment selected from the group consisting of oxidized magnetite and chromium dioxide, the magnetosolid particles being adsorbed on the surface of the magnetosoft particles; (c) 4 to 9 parts of a silicon dioxide stabilizer; and (d) 25 to 55 parts of a carrying fluid comprising 5 to 10 weight percent polyvinyl-n-butyl ether, 0.01 to 1.0 weight percent α-naphthol and 90 to 95 weight percent kerosene.
Claim 12
Independent Claim
89 words
A method of making a stable magnetorheological fluid composition comprising: (a) preparing a carrying fluid comprising a vinyl ether, an aromatic alcohol and an organic solvent; (b) preparing a first carrying fluid composition comprising magnetosoft particles, a stabilizer and a first sample of the carrying fluid; (c) preparing a second carrying fluid composition comprising magnetosolid particles having their own magnetic moment comprising oxidized magnetite or chromium dioxide and a second sample of the carrying fluid; and (d) admixing the first carrying fluid composition and the second carrying fluid composition.
Claim 13
Independent Claim
89 words
A method of making a stable magnetorheological fluid composition comprising: (a) preparing a carrying fluid comprising a vinyl ether, an aromatic alcohol and an organic solvent; (b) preparing a first carrying fluid composition comprising magnetosoft particles, a stabilizer and a first sample of the carrying fluid; (c) preparing a second carrying fluid composition comprising magnetosolid particles having their own magnetic moment comprising oxidized magnetite or chromium dioxide and a second sample of the carrying fluid; and (d) admixing the first carrying fluid composition and the second carrying fluid composition.
Claim 14
Dependent Claim
16 words
A method according to claim 10 wherein the second carrying fluid composition further comprises oleic acid.
Claim 15
Dependent Claim
19 words
A method according to claim 10 wherein the magnetosoft particles comprise carbonyl iron and the stabilizer is silicon dioxide.
Claim 16
Dependent Claim
12 words
A method according to claim 10 wherein the organic solvent is kerosene.
Claim 17
Dependent Claim
42 words
A ferromagnetic particle system suitable for use in a rheologic fluid comprising a first, magnetosoft particle comprising a carbonyl iron whose surface has adsorbed thereon second, relatively smaller needle-like magnetosolid particles having their own magnetic moment comprising oxidized magnetite or chromium dioxide.
Claim 18
Dependent Claim
42 words
A ferromagnetic particle system suitable for use in a rheologic fluid comprising a first, magnetosoft particle comprising a carbonyl iron whose surface has adsorbed thereon second, relatively smaller needle-like magnetosolid particles having their own magnetic moment comprising oxidized magnetite or chromium dioxide.
Claim 19
Dependent Claim
70 words
A magnetorheological fluid composition comprising: first particles comprising chromium dioxide magnetosolid particles having their own magnetic moment and being adsorbed on the surface of second particles comprising relatively larger magnetosoft particles; a stabilizer; and a carrying fluid comprising an aromatic alcohol, a vinyl ether, and an organic solvent, in proportions sufficient to provide substantially no agglomeration or sedimentation of magnetic particles over temperatures of from about -50° to 120° C.
Claim 20
Dependent Claim
70 words
A magnetorheological fluid composition comprising: first particles comprising chromium dioxide magnetosolid particles having their own magnetic moment and being adsorbed on the surface of second particles comprising relatively larger magnetosoft particles; a stabilizer; and a carrying fluid comprising an aromatic alcohol, a vinyl ether, and an organic solvent, in proportions sufficient to provide substantially no agglomeration or sedimentation of magnetic particles over temperatures of from about -50° to 120° C.
Claim 21
Dependent Claim
83 words
A magnetorheological fluid composition comprising: (a) 20 to 70 parts of magnetosoft carbonyl iron particles; (b) 0.5 to 20 parts of chromium dioxide magnetosolid particles having their own magnetic moment, the magnetosolid particles being adsorbed on the surface of the magnetosoft particles; (c) 4 to 9 parts of a silicon dioxide stabilizer; and (d) 25 to 55 parts of a carrying fluid comprising 5 to 10 weight percent polyvinyl-n-butyl ether, 0.01 to 1.0 weight percent α-naphthol and 90 to 95 weight percent kerosene.
Claim 22
Dependent Claim
83 words
A magnetorheological fluid composition comprising: (a) 20 to 70 parts of magnetosoft carbonyl iron particles; (b) 0.5 to 20 parts of chromium dioxide magnetosolid particles having their own magnetic moment, the magnetosolid particles being adsorbed on the surface of the magnetosoft particles; (c) 4 to 9 parts of a silicon dioxide stabilizer; and (d) 25 to 55 parts of a carrying fluid comprising 5 to 10 weight percent polyvinyl-n-butyl ether, 0.01 to 1.0 weight percent α-naphthol and 90 to 95 weight percent kerosene.
Claim 23
Independent Claim
85 words
A method of making a stable magnetorheological fluid composition comprising: (a) preparing a carrying fluid comprising a vinyl ether, an aromatic alcohol and an organic solvent; (b) preparing a first carrying fluid composition comprising magnetosoft particles, a stabilizer and a first sample of the carrying fluid; (c) preparing a second carrying fluid composition comprising chromium dioxide magnetosolid particles having their own magnetic moment and a second sample of the carrying fluid; and (d) admixing the first carrying fluid composition and the second carrying fluid composition.
Claim 24
Independent Claim
85 words
A method of making a stable magnetorheological fluid composition comprising: (a) preparing a carrying fluid comprising a vinyl ether, an aromatic alcohol and an organic solvent; (b) preparing a first carrying fluid composition comprising magnetosoft particles, a stabilizer and a first sample of the carrying fluid; (c) preparing a second carrying fluid composition comprising chromium dioxide magnetosolid particles having their own magnetic moment and a second sample of the carrying fluid; and (d) admixing the first carrying fluid composition and the second carrying fluid composition.
Claim 25
Dependent Claim
36 words
A ferromagnetic particle system suitable for use in a rheologic fluid comprising a magnetosoft particle comprising a carbonyl iron whose surface has adsorbed thereon relatively smaller needle-like chromium dioxide magnetosolid particles having their own magnetic moment.
Claim 26
Dependent Claim
36 words
A ferromagnetic particle system suitable for use in a rheologic fluid comprising a magnetosoft particle comprising a carbonyl iron whose surface has adsorbed thereon relatively smaller needle-like chromium dioxide magnetosolid particles having their own magnetic moment.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1999-06-11 | 1999-12-11 | 2000-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-06-11 | 2003-12-11 | 2004-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-06-11 | 2007-12-11 | 2008-06-11 | $7700.00 | Window Closed / Lapsed |