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US4502973A
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Electroviscous fluids
Assignee: BTG International Ltd
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Filing: 1982-06-18
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Granted: 1985-03-05
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Expires: 2002-06-18
Abstract
Abstract PCT No. PCT/GB82/00183 Sec. 371 Date Feb. 3, 1983 Sec. 102(e) Date Feb. 3, 1983 PCT Filed Jun. 18, 1982 PCT Pub. No. WO82/04442 PCT Pub. Date Dec. 23, 1982.Electroviscous (EV) fluids consisting of solid hydrophilic particles dispersed in hydrophobic liquids, where the liquid contains a diaryl derivative component of general formula I <IMAGE> I in which R is CY2,O,S,SO,SO2,SiF2, or O-SiY2-O,X1 and X2 are halogens, (m+n) is between 1 and 3 on average, and (p+q) is between 0 and 1 on average. EV fluids containing these novel components possess generally improved properties in terms of lower viscosities, electrical conductivities, toxicities and freezing points. In a preferred embodiment, the component is a mixture of brominated diphenyl methanes in which R is CH2,n=O,X1=Br,(m+n) is approximately one, and (p+q)=0.
Inventors
- 👤 James E. Stangroom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 07:09
CPC Classifications
C; C10; C10M; C10M171/00; C10M171/001; C07; C07C; C07C17/00; C07C17/093; C07C17/10; C07C17/12; C08; C08K; C08K5/00; C08K5/0008
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
132 words
An electroviscous liquid comprising a hydrophilic solid and a hydrophobic liquid component wherein the hydrophobic liquid component comprises at least one diaryl derivative of general formula I ##STR4## wherein R is CY 2 , O, S, SO, SO 2 , SiO 2 , SiF 2 or O-SiY 2 -O, X 1 and X 2 are either the same or different and are F, Cl or Br, each of m and n is 0, 1, 2 or 3, each of p and q is 0, 1 or 2 and Y is H, F or a methyl or ethyl group, provided that, for the said diaryl derivatives in the liquid component, the average value of (m+n) is from 1 to 3 inclusive and the average value of (p+q) is from 0 to 1 inclusive.
Claim 2
Dependent Claim
132 words
An electroviscous liquid comprising a hydrophilic solid and a hydrophobic liquid component wherein the hydrophobic liquid component comprises at least one diaryl derivative of general formula I ##STR4## wherein R is CY 2 , O, S, SO, SO 2 , SiO 2 , SiF 2 or O-SiY 2 -O, X 1 and X 2 are either the same or different and are F, Cl or Br, each of m and n is 0, 1, 2 or 3, each of p and q is 0, 1 or 2 and Y is H, F or a methyl or ethyl group, provided that, for the said diaryl derivatives in the liquid component, the average value of (m+n) is from 1 to 3 inclusive and the average value of (p+q) is from 0 to 1 inclusive.
Claim 3
Dependent Claim
51 words
An electroviscous fluid according to claim 1 wherein R is CH 2 , O, or S, X 1 and X 2 are the same or different and are Cl or Br, each of m and n is 0, 1, or 2, and each of p and q is 0 or 1.
Claim 4
Dependent Claim
46 words
An electroviscous fluid according to claim 2 wherein R is CH 2 , X 1 and X 2 are Br, each of m and n is 0, 1 or 2, each of p and q is 0 and the average value of (m+n) is about 1.
Claim 5
Dependent Claim
26 words
An electroviscous fluid according to claim 1 wherein more than 80% of the at least one diaryl derivatives in the hydrophobic liquid component are asymmetrically substituted.
Claim 6
Dependent Claim
23 words
An electroviscous fluid according to claim 1 wherein the molar volume of the hydrophobic liquid component is above about 120 cm 3 .
Claim 7
Dependent Claim
28 words
An electroviscous fluid according to claim 1 wherein the density of the hydrophobic liquid component at 20° C. is between about 1.2 and 1.8 gm cm -3 .
Claim 8
Dependent Claim
32 words
An electroviscous fluid according to claim 1 wherein the hydrophobic liquid component further comprises at least one further hydrophobic liquid selected from the group consisiting of hydrocarbons, fluorinated polymers and polychlorinated biphenyls.
Claim 9
Dependent Claim
18 words
An electroviscous fluid according to claim 1 wherein the hydrophilic solid comprises a polyhydric alcohol in particulate form.
Claim 10
Dependent Claim
30 words
An electroviscous fluid according to claim 1 wherein the hydrophilic solid comprises water-containing polymer particles having free or neutralised acid groups, provided that the polymer is not a polyhydric alcohol.
Claim 11
Dependent Claim
21 words
An electroviscous fluid according to claim 9 wherein the hydrophilic solid comprises lithium polymethacrylate (LiPM) either in cross-linked or non-cross-linked form.
Claim 12
Dependent Claim
16 words
An electroviscous fluid according to claim 10 wherein the LiPM is cross-linked with methylene bis-acrylamide (MBA).
Claim 13
Dependent Claim
32 words
An electroviscous fluid according to claim 9 wherein the fluid contains between about 25 and 35% (v/v) of the polymer particles, said particles having sizes of between about 1 and 50 microns.
Claim 14
Dependent Claim
17 words
An electroviscous fluid according to claim 7 wherein the fluorinated polymer is a polymer of trifluorovinyl chloride.
Claim 15
Dependent Claim
21 words
An electroviscous fluid according to claim 11 wherein the molar ratio of methacrylic acid content to MBA is 6 to 1.
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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) | 1988-03-04 | 1988-09-03 | 1989-03-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-03-04 | 1992-09-03 | 1993-03-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-03-04 | 1996-09-03 | 1997-03-05 | $7700.00 | Window Closed / Lapsed |