Nippon Shokubai Co., Ltd.

Ckd Corporation

Satoru Ono

Yoshinobu Asako

Ryuji Aizawa

Izuho Okada

Minoru Kobayashi

Kiyomi Arimatsu

Yoshikuni Mori

Minoru Aoki

Kazutoshi Ito

Eiji Uematu

According to the present invention, electrorheological fluid is deaerated after it is sealed in a closed device which is operated by the electrorheological fluid. Thus, it is possible to control the operation of the closed device in accordance with an electric field. Additionally, the control of viscosity is not affected by repetitive operations of the closed device, thereby obtaining a closed device having a smooth operation and good repeatability. The deaeration is achieved under a predetermined reduced pressure, for example, of not more than 100 torr. In addition thereto, a suitable heating process is carried out as required.

Method for deaerating electrorheological fluid in a closed device

An electrorheological fluid composition comprises dielectric particles as a disperse-phase and an electrically insulating oil as a dispersion medium, wherein the dielectric particle has a polymer portion and an electrically conductive carbon black portion and the polymer portion is grafted on the carbon black portion. The electrorheological fluid composition shows a large change in viscosity and the small current properties under an applied electric field, and excellent fluidity and dispersion stability in an absence of an applied electric field.

Electrorheological fluid composition comprising an electrically

An electrorheological fluid composition is composed of a dispersed phase of dielectric solid particles and a dispersion medium of an electrically insulating solution, wherein the solution is composed of 99-75% by weight of silicone oil and 1-25% by weight of an organic compound having at least one unsaturated bond. The composition generates a large shear stress even under an electric field of relatively low intensity, and the concurrent current density is small. The composition shows excellent performances also in terms of its withstanding dielectric breakdown strength under an electric field of high intensity and the fluidity and re-dispersibility in the absence of an electric field. In the meantime, the composition has high durability of the generated shear stress and the current density.

Electrorheological fluid composition including hydrocarbon compound

An electrorheological fluid comprising dielectric particles and an insulating liquid and characterized by exhibiting a viscosity of not more than 0.2 Pa.cndot.s at a shear rate of 33/s when measured at 25.degree. C. in the absence of supply of an electric field and a structural viscosity satisfying the condition of the formula (1):

Electrorheological fluid with improved properties comprising composite

An electrorheological fluid comprising a dielectric particle as the dispersed phase, an insulating oil as the dispersing medium, and an additive, the additive being substantially insoluble in the dispersing medium, and being a composite containing a polysiloxane-containing structural unit (A), and at least one dispersed phase absorbing chain-containing structural unit (B) selected from the group consisting of an alkylene oxide chain-containing structural unit (B-1), a nitrogen atom chain-containing structural unit (B-2), and a long hydrocarbon chain-containing structural unit (B-3).

Electrorhelogical fluid

An electrorheological fluid composition comprising a dispersion of disperse-phase particles formed of a sulfonated polymer possessing aromatic rings substituted with sulfonic acid groups in an electrically non-conducting oil which electrorheological fluid is characterized by the fact that the number of sulfonic acid groups in said sulfonated polymer forming said disperse-phase particles exceeds the number of aromatic rings present in said sulfonated polymer.

Growing community of inventors

Tsuchiura, Japan

Satoru Ono