Electric field responsive fluids
US4483788A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 14, 1983 |
| Grant date | Nov 20, 1984 |
| Priority date | — |
| Expiry date | Mar 14, 2003 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2361/06
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
An electroviscous (EV) fluid composition whose fluid properties are altered in the presence of an electric field comprises water-containing particles of a phenol-formaldehyde polymer dispersed in a non-conducting liquid. The composition, selected from the broad range of fluid compositions of UK Pat. No. 1570234, possesses improved fluid properties combined with markedly reduced electrical conductivity, and is thus more suitable for use in applications such as at the interface between electronics and power hydraulics for example. In a preferred embodiment of the present invention the polymer comprises the dilithium salt of 2,2', 4,4' tetrahydroxybenzophenone condensed with formaldehyde, dispersed at 30% V/V in a mixture of brominated diphenyl methane (BDM) liquid components having the averaged formula C.sub.6 H.sub.4 Br.CH.sub.2.C.sub.6 H.sub.5.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.