| 摘要 |
PROBLEM TO BE SOLVED: To obtain a magnetic fluid with a low viscosity, a low volatility, and a long-term stability by providing a monocarboxylic acid monoester that is expressed by a specific expression and magnetic particles in a fine particle shape that are dispersed in the monocarboxylic acid monoester and is covered with a fatty acid. SOLUTION: A compound indicated by an expression (in the expression, R<1> ; a saturated hydrocarbon group with 7-17 carbons, R<2> : a saturated hydrocarbon group with 8-20 carbons, and the saturated hydrocarbon group that is expressed by R<1> and R<2> is selected so that the total number of carbons ranges from 23 to 33) is used as a monocarboxylic acid monoester in a magnetic fluid. Ferrite and a metal magnetic body particle are used as the magnetic body particle of a magnetic fluid. Then, a fatty acid is adsorbed by the surface of the magnetic particle. The content of the magnetic particle in a fine particle shape being covered with the adsorbed fatty acid ranges from 5 to 60wt.%. A natural oxidation prevention agent or a synthetic oxidation prevention agent can be used as an addition agent. |
