| 摘要 |
PURPOSE:To obtain a low cost magnetic fluid having highly saturated magnetism by using a particular surface active agent in a magnetic fluid including fine particles of iron, surface active agent and medium. CONSTITUTION:Iron may be partly oxidized. As the surface active agent, one or more kinds of compound expressed by the general equation I is used and thereby it may be stably dispersed into the medium. In this equation, L is alkylene chain and particularly indicates a low class alkylene group. R is hydrocarbon residual group, particularly a substitution or non-substitution alkyl group or allyl group. As the allyl group, the alkyl allyl group is particularly desirable. n is selected to 2 or 3 and di- or triphosphoric ester. A total number mXn of the alkylene oxide chain in the molecule is an integer from 2 to 10. |
