Electrorheological fluid and electric device
AssigneeAsahi Kasei Kabushiki Kaisha
InventorsAkio INOUE, Tomoko KOZONO
Life of this patent
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Abstract
An electrorheological fluid which comprises a dispersion medium containing fluorine atoms in an amount larger than 0 wt % but not larger than 50.0 wt % and particles for electrorheological fluid use that are contained in the dispersion medium in an amount of 10-50 vol % of the total volume of the dispersion medium and the particles, the particles comprising a sulfonic-acid-group-containing polymer having a sulfonic acid group content of 30-70 wt %.
Claims12
An electrorheological fluid comprising:
- a dispersion medium containing fluorine atoms in an amount of over 0 wt % and 50.0 wt % or smaller in which
- particles for electrorheological fluid containing a sulfonic acid group-containing polymer having a content of sulfonic acid groups of 30 wt % or greater and 70 wt % or smaller are contained in an amount of 10 vol % or greater and 50 vol % or smaller with respect to the total volume of the dispersion medium and the particles.
An electrorheological fluid comprising
- a dispersion medium containing fluorine atoms in which
- particles for electrorheological fluid containing a sulfonic acid group-containing polymer are contained, wherein
- an electrorheological effect X expressed by the following formula (1) is 140 or greater:
- X=S1/S0 (1)
- (in which formula (1), S1 is the shear stress when applying a 3.0 kV/mm electric field, while S0 is the shear stress when not applying an electric field).
Particles for electrorheological fluid containing a sulfonic acid group-containing polymer, in which particles for electrorheological fluid,
- the content of the sulfonic acid groups in the particles for electrorheological fluid is 30 wt % or greater, and
- the content of the chlorine atoms in the particles for electrorheological fluid is 1 ppm or greater and 5,000 ppm or smaller.
An electric device comprised of an electrorheological fluid which is comprised of a dispersion medium in which particles for electrorheological fluid are contained and which is filled between a pair of electrodes, in which electric device,
- in a region of at least part of at least one surface of the surfaces of the pair of electrodes facing each other, an arithmetic mean roughness (Ra) is 0.5 μm or greater and less than 300 μm and a mean length (RSm) of roughness curve elements is 10 nm or greater and less than 100 μm.
Dependencies are inferred from the claim text.