US5322756A
Expired / Lapsed
US
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Magnetic fluids and method of preparation
Assignee: Xerox Corp
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Filing: 1992-07-09
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Granted: 1994-06-21
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Expires: 2012-07-09
Abstract
Abstract The invention provides low optical density magnetic fluid which is a stable dispersion of fine magnetic particles. The invention further provides a method of forming the stable dispersion which includes providing an ion exchange resin, loading the ion exchange resin with an ion capable of forming a magnetic phase, treating the loaded resin to form magnetic particles and micronizing the resin and magnetic particles in a fluid to form an aqueous stable colloid.
Inventors
- 👤 Ronald F. Ziolo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:42
CPC Classifications
B; B82; B82Y; B82Y25/00; G; G03; G03G; G03G9/00; G03G9/08; G03G9/083; G03G9/0831; G03G9/0833; G03G9/0837; G03G9/087; G03G9/08784; G03G9/08791; G03G9/12; G03G9/13; H; H01; H01F; H01F1/00; H01F1/0036; H01F1/0045; H01F1/0063; H01F1/44; H01F41/00; H01F41/14; H01F41/16; F; F16; F16C; F16C2206/00; F16C2206/02; F16C2206/04; F16C2240/00; F16C2240/40; F16C2240/60; F16C2240/64; Y; Y10; Y10S; Y10S430/00; Y10S430/001; Y10S430/104
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
58 words
A method of forming a magnetic fluid consisting essentially of providing an ion exchange resin; loading said resin with an ion capable of forming a magnetic phase; treating the resin to cause in-situ formation of magnetic particles; and fluidizing said ion exchange resin and magnetic particles in an aqueous medium to form a stable colloid of magnetic particles.
Claim 2
Independent Claim
58 words
A method of forming a magnetic fluid consisting essentially of providing an ion exchange resin; loading said resin with an ion capable of forming a magnetic phase; treating the resin to cause in-situ formation of magnetic particles; and fluidizing said ion exchange resin and magnetic particles in an aqueous medium to form a stable colloid of magnetic particles.
Claim 3
Dependent Claim
19 words
The method according to claim 1, wherein said ion exchange resin and magnetic particles are micronized by ball milling.
Claim 4
Dependent Claim
25 words
The method according to claim 1, wherein said ion exchange resin and magnetic particles are micronized by air attrition followed by dispersion in a fluid.
Claim 5
Dependent Claim
18 words
The method according to claim 1, wherein said ion exchange resin and magnetic particles are micronized by shaking.
Claim 6
Dependent Claim
24 words
The method according to claim 1, wherein said loading and treating steps are repeated a plurality of times before the micronization step takes place.
Claim 7
Dependent Claim
16 words
The method according to claim 5, wherein said loading and treating steps are repeated 10 times.
Claim 8
Dependent Claim
20 words
The method according to claim 1, wherein said loading and treating steps are repeated until the ion exchange resin ruptures.
Claim 9
Dependent Claim
30 words
The method according to claim 1, wherein the ion capable of forming a magnetic phase is selected from those derived from iron, cobalt, nickel, manganese, vanadium, chromium or rare earths.
Claim 10
Dependent Claim
19 words
The method according to claim 1, wherein the ion capable of forming a magnetic phase is a ferrous ion.
Claim 11
Dependent Claim
19 words
The method according to claim 1, wherein the ion capable of forming a magnetic phase is a ferric ion.
Claim 12
Dependent Claim
22 words
The method according to claim 1, wherein the ion exchange resin is a polystyrene sulfonic acid ion exchange resin crosslinked with divinylbenzene.
Claim 13
Dependent Claim
19 words
The method according to claim 11, wherein the resin is about a 4 to 8% divinylbenzene crosslinked sulfonated polystyrene.
Claim 14
Dependent Claim
17 words
The method according to claim 1, wherein the resin is from about 20 to 400 mesh size.
Claim 15
Dependent Claim
17 words
The method according to claim 12, wherein the resin is from about 200 to 400 mesh size.
Claim 16
Dependent Claim
20 words
The method according to claim 1, wherein the fluidizing is carried out in from about 30 to about 180 minutes.
Claim 17
Dependent Claim
20 words
The method according to claim 1, wherein the magnetic particles are from about 50 to about 150 Å in size.
Claim 18
Dependent Claim
14 words
A low optical density magnetic fluid produced by the process according to claim 1.
Claim 19
Dependent Claim
26 words
A low optical density magnetic fluid comprising an aqueous stable colloid of magnetic particles wherein the colloid contains a fluidized matrix of an ion exchange resin.
Claim 20
Dependent Claim
26 words
A low optical density magnetic fluid comprising an aqueous stable colloid of magnetic particles wherein the colloid contains a fluidized matrix of an ion exchange resin.
Claim 21
Dependent Claim
20 words
The magnetic fluid according to claim 18, wherein the magnetic particles are about 50 to about 150 Å in size.
Claim 22
Dependent Claim
29 words
The magnetic fluid according to claim 18, wherein the optical density is reduced by from about 25% to about 70% of the values for the material prior to fluidization.
Claim 23
Dependent Claim
23 words
The magnetic fluid according to claim 18, wherein the value of ln(I o /I)/d at 700 nanometers is about 170 cm -1 .
Claim 24
Dependent Claim
25 words
The magnetic fluid according to claim 18, wherein the fluid has a magnetic saturation moment of from about less than 1 to about 8 emu/g.
Claim 25
Independent Claim
77 words
A method of forming a single component colored magnetic fluid consisting essentially of the following steps in order: providing an ion exchange resin; loading said resin with an ion capable of forming a magnetic phase; treating the resin to cause in-situ formation of magnetic particles; and introducing a pigment, a dye, an ion exchange dye or a chromophore; micronizing said ion exchange resin and magnetic particles in a fluid to form a stable colloid of magnetic particles.
Claim 26
Independent Claim
77 words
A method of forming a single component colored magnetic fluid consisting essentially of the following steps in order: providing an ion exchange resin; loading said resin with an ion capable of forming a magnetic phase; treating the resin to cause in-situ formation of magnetic particles; and introducing a pigment, a dye, an ion exchange dye or a chromophore; micronizing said ion exchange resin and magnetic particles in a fluid to form a stable colloid of magnetic particles.
Claim 27
Dependent Claim
23 words
The method according to claim 23, wherein the ion exchange dye or chromophore is red, blue, green, magenta, cyan, yellow or mixtures thereof.
Claim 28
Independent Claim
78 words
A method of forming a low optical density colored magnetic fluid consisting essentially of the following steps in order: providing an ion exchange resin; loading said resin with an ion capable of forming a magnetic phase; treating the resin to cause in-situ formation of magnetic particles; micronizing said ion exchange resin and magnetic particles in a fluid to form a stable colloid of magnetic particles; and introducing a pigment, a dye, an ion exchange dye or a chromophore.
Claim 29
Independent Claim
78 words
A method of forming a low optical density colored magnetic fluid consisting essentially of the following steps in order: providing an ion exchange resin; loading said resin with an ion capable of forming a magnetic phase; treating the resin to cause in-situ formation of magnetic particles; micronizing said ion exchange resin and magnetic particles in a fluid to form a stable colloid of magnetic particles; and introducing a pigment, a dye, an ion exchange dye or a chromophore.
Claim 30
Dependent Claim
23 words
The method according to claim 25, wherein the ion exchange dye or chromophore is red, blue, green, magenta, cyan, yellow or mixtures thereof.
Claim 31
Dependent Claim
23 words
A single component colored magnetic fluid comprising a magnetic fluid as produced by the process according to claim 1 and a color component.
Claim 32
Dependent Claim
32 words
The colored magnetic fluid according to claim 27, wherein the color component is selected from a colloidal suspension of a colored pigment or dye, or an ion exchange dye or a chromophore.
Claim 33
Dependent Claim
22 words
The colored magnetic fluid according to claim 27, wherein the color component is red, blue, green, magenta, cyan, yellow or mixtures thereof.
Claim 34
Dependent Claim
23 words
The colored magnetic fluid according to claim 28, wherein the color component is present in an amount from about 1% to about 20%.
Claim 35
Dependent Claim
23 words
The colored magnetic fluid according to claim 30, wherein the color component is present in an amount from about 1% to about 10%.
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| 3.5 Years (Year 4) | 1997-06-20 | 1997-12-20 | 1998-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-06-20 | 2001-12-20 | 2002-06-21 | $3760.00 | Window Closed / Lapsed |
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