Patent ID: 6824701
Filing Date: 2004-11-30
Classification: H01F

Abstract:
A magnetorheological fluid comprising:10 to 14 weight percent of a hydrocarbon-based liquid; 86 to 90 weight percent of bimodal magnetizable particles; 0.05 to 0.5 weight percent fumed silica; an additive package including a paraffin oil, a phenol and a sulfide, wherein the phenol has one of a formula comprising: and wherein in formulas (IA) and (IB) each of; R1, R2, R3, R4, and R5, includes one of H, CH3, CnH2+2, CnH2n+1, CnH2n, CnH2nâˆ’1, CnHn+2, CnHn+1, CnHn, CnHnâˆ’1, CnHnâˆ’2, HO, CH3Om, CnH2n+2Om, CnH2n+1Om, CnH2nOm, CnH2nâˆ’1Om, CnHn+2Om, CnHn+1Om, CnHnOm, CnHnâˆ’1Om, CnHnâˆ’2Om, CnHnâˆ’3Om, CnHnâˆ’4Om, CnHnâˆ’5Omand CnHnâˆ’6Om, wherein n is an integer from 1 to 24, and m is an integer from 1 to 6, and wherein each of v, w, x, y, and z is an integer from 0 to 5; and wherein the sulfide has one of a formula comprising: (R6)jâ€”Sâ€”(R7)kâ€ƒâ€ƒFormula (IIA) and(R6)jâ€”Sâ€”Sâ€”(R7)kâ€ƒâ€ƒ(Formula (IIB) and(R6)jâ€”Sâ€”Sâ€”Sâ€”(R7)kâ€ƒâ€ƒFormula (IIC) and(R6)jâ€”Sâ€”Sâ€”Sâ€”Sâ€”(R7)kâ€ƒâ€ƒFormula (IID)ps and wherein in formulas (IIA), (IIB), (IIC), and (IID) each of R6 and R7, includes one of H, CH3, CnH2n+2, CnH2n+1, CnH2n, CnH2nâˆ’1, CnH2n+2, CnHn+1, CnHn, and CnHnâˆ’1 groups, wherein n is an integer from 1 to 24 and wherein j and k is an integer from 2 to 24.