Magneto-rheological fluid with improved re-dispersion property and re-dispersion property evaluation method for magneto-rheological fluid

摘要

Magnetorheological fluids and methods for evaluating redispersibility of magnetorheological fluids are disclosed. The magnetorheological fluid according to the present invention is a magnetorheological fluid containing magnetic particles, a dispersion medium, and an additive, and collects all solid contents in the magnetorheological fluid to measure the particle size distribution, and the span value defined as follows: When obtaining (span value), span value = (D90−D10) / D50, wherein the span value is 1.3 or more. The method for evaluating redispersibility of a magnetorheological fluid according to the present invention provides a transparent container containing the magnetorheological fluid, and the transparent container is irradiated with near infrared rays while rotating the transparent container with a centrifuge. Measuring the amount of light that passes through (measurement of primary dispersion stability), applying an external force to the magnetorheological fluid to re-disperse the solid content after centrifugation in a dispersion medium, and re-dispersing the solid content The method includes the step of measuring the amount of light transmitted through the transparent container (secondary dispersion stability measurement) by irradiating near infrared rays while rotating the transparent container containing the magnetorheological fluid again with a centrifuge. [Selection] Figure 1