MAGNETIC FLUID USING POLY(12-HYDROXYSTEARIC ACID) DISPERSANT HAVING ACIDIC END

摘要

PROBLEM TO BE SOLVED: To form a stable magnetic fluid composition having an improved resistance against oxidative deterioration by using a poly(12-hydroxystearic acid) dispersant having an acidic end in a polar ester-based dispersing medium as an independent dispersant. ;SOLUTION: A magnetic fluid composition is prepared by blending a polar ester dispersing medium for polymer composed of an ester palsticizer, etc., magnetic particles of a magnetite, etc., and a poly(12-hydroxystearic acid) dispersant having an acidic end and the structure expressed by the chemical formula (where, R and n respectively represent a substituted or nonsubstituted alkyl group, aralkyl group, or aryl group and an integer of 0-4) with each other. The dispersant is prepared by mixing substances having the same or different R and n in the chemical formula together. Therefore, the magnetic particles can be effectively dispersed in the dispersing medium, without the use of second dispersant and a very stable magnetic fluid having a superior resistance to oxidative deterioration can be formed.;COPYRIGHT: (C)1999,JPO