Patent US3548269A successfully refreshed from Google Patents.
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US4033892A
Expired / Lapsed
US
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Electric field responsive fluids
Assignee: BTG International Ltd
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Filing: 1975-07-07
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Granted: 1977-07-05
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Expires: 1995-07-07
Abstract
Abstract A fluid composition which is capable of exhibiting a substantial increase in apparent viscosity under the influence of an electric field and which is of the type wherein solid particles of a chemical substance are dispersed in an electrically non-conducting oleaginous vehicle, the chemical substance being a polyhydric alcohol which contains acid groups and which has an open structure wherein a significant amount of water is adsorbed.
Inventors
- 👤 James Edward Stangroom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 06:55
CPC Classifications
F; F16; F16D; F16D37/00; F16D37/008; C; C08; C08L; C08L27/00; C08L27/02; C08L27/12; C08L5/00; C08L71/00; C08L71/02; C10; C10M; C10M171/00; C10M171/001
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
55 words
An electroviscous fluid which comprises at least one polyhydric alcohol in solid particulate form which polyhydric alcohol contains acid groups selected from the group consisting of carboxylic acid groups and sulphonic acid groups and has a structure in which water is adsorbed, and an electrically non-conducting oleaginous vehicle in which the solid particles are dispersed.
Claim 2
Dependent Claim
55 words
An electroviscous fluid which comprises at least one polyhydric alcohol in solid particulate form which polyhydric alcohol contains acid groups selected from the group consisting of carboxylic acid groups and sulphonic acid groups and has a structure in which water is adsorbed, and an electrically non-conducting oleaginous vehicle in which the solid particles are dispersed.
Claim 3
Dependent Claim
23 words
A composition according to claim 1 wherein the polyhydric alcohol is at least substantially insoluble both in water and in the oleaginous vehicle.
Claim 4
Dependent Claim
16 words
a composition according to claim 1 wherein the polyhydric alcohol is a polymer of a monosaccharide.
Claim 5
Dependent Claim
15 words
A composition according to claim 3 wherein the polymer of a monosaccharide is alginic acid.
Claim 6
Dependent Claim
17 words
A composition according to claim 4 wherein the oleaginous vehicle has a molar volume greater than 110.
Claim 7
Dependent Claim
19 words
A composition according to claim 3 wherein the polymer of a monosaccharide is a carboxymethyl Sephadex (Registered Trade Mark).
Claim 8
Dependent Claim
19 words
A composition according to claim 3 wherein the polymer of a monosaccharide is a sulphopropyl Sephadex (Registered Trade Mark).
Claim 9
Dependent Claim
18 words
A composition according to claim 1 wherein the polyhydric alcohol is a co-polymer of a plurality of monosaccharides.
Claim 10
Dependent Claim
18 words
A composition according to claim 1 wherein the polyhydric alcohol is present in the form of a salt.
Claim 11
Dependent Claim
17 words
A composition according to claim 9 wherein the salt is a sodium carboxymethyl Sephadex (Registered Trade Mark).
Claim 12
Dependent Claim
23 words
A composition according to claim 1 wherein the polyhydric alcohol is greater than 25% and less than 40% of the composition, by volume.
Claim 13
Dependent Claim
22 words
A composition according to claim 11 wherein the volume fraction of the polyhydric alcohol is greater than 30% and less than 35%.
Claim 14
Dependent Claim
27 words
A composition according to claim 1 wherein the solid particles of the polyhydric alcohol have diameters which are greater than 1 μm and less than 50 μm.
Claim 15
Dependent Claim
23 words
A composition according to claim 13 wherein the solid particles have diameters which are greater than 4 μm and less than 20 μm.
Claim 16
Dependent Claim
34 words
A composition according to claim 1 wherein the amount of adsorbed water is a function of the acid strength of the polyhydric alcohol, the amount of adsorbed water increasing with a decreasing acid strength.
Claim 17
Dependent Claim
25 words
A composition according to claim 15 wherein the amount of adsorbed water is between 4% and 12% by weight of the amount of polyhydric alcohol.
Claim 18
Dependent Claim
17 words
A composition according to claim 1 wherein the oleaginous vehicle has a molar volume greater than 80.
Claim 19
Dependent Claim
23 words
A composition according to claim 1 wherein the oleaginous vehicle is density matched to the polyhydric alcohol in which the water is adsorbed.
Claim 20
Dependent Claim
46 words
A composition according to claim 1 wherein the oleaginous vehicle is an admixture of at least two compounds, one compound having a density greater than the density of the polyhydric alcohol and the other compound having a density lower than the density of the polyhydric alcohol.
Claim 21
Dependent Claim
13 words
A fluid according to claim 1 including a fluidizer which comprises sorbitan nono-oleate.
Claim 22
Dependent Claim
13 words
A fluid according to claim 1 including a fluidizer which comprises sorbitan sesquioleate.
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) | 1980-07-04 | 1981-01-03 | 1981-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-04 | 1985-01-03 | 1985-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-04 | 1989-01-03 | 1989-07-05 | $7700.00 | Window Closed / Lapsed |