| 摘要 |
PURPOSE:To obtain a water-base magnetic field having good blackness by dispersing coprecipitated fine ferrite particles containing an adsorbed N- polyalkylenepolyamine-substituted alkenylsuccinimide in water in the presence of an anionic surfactant. CONSTITUTION:This water-base magnetic fluid is prepared by dispersing coprecipitated fine ferrite particles adsorbing an N-polyalkylenepolyamine- substituted alkenylsuccinimide in water in the presence of an anionic surfactant. Examples of the alkenylsuccinimide to be used include compounds of formulas I and II, wherein R is a 12-14C hydrocarbon group or a polybutenyl group having a molecular weight of about 300 to 2,000, R' is a 1-6C alkylene group and may be the same or different from each other when two or more R' groups are repeated, (n) is 1 to 5, and (m) is 0 to 4. This fluid is used for underlining, a color pen, a writing-brush pen, etc., as e.g. a wet pen for writing and office work. |
