公开(公告)号：US20240400931A1

公开(公告)日：2024-12-05

申请号：US18691260

申请日：2022-09-14

Applicant: HITACHI ASTEMO, LTD.

Inventor： Satoshi ISHII ,  Seogchul SHIN ,  Yuichiro YAMAMOTO ,  Hitomi TAKAHASHI

IPC: C10M149/14 ,  C08G18/08 ,  C08G18/32 ,  C08G18/48 ,  C08G18/66 ,  C10N40/08 ,  F16F9/53

Abstract: Provided is an electro-rheological fluid, including: a fluid having an insulating property; and a polyether-based polyurethane particle containing a metal ion, wherein the polyurethane particle contains a chain extender, wherein the metal ion includes at least a Li ion, and wherein a ratio ([Li]/[O]) of a molar concentration ([Li]) of the Li ion to a molar concentration ([O]) of oxygen atoms of ether groups in the polyurethane particles satisfies the following condition: [Ratio of molar concentration ([Li]) of Li ion to molar concentration ([O]) of oxygen of ether groups] [Li]/[O]≥9.0×10−5.