PROCESS OF PRODUCTION OF MAGNETIC FLUID ON SILICON-ORGANIC BASE Russian patent published in 1994 - IPC

FIELD: chemical reactors. SUBSTANCE: process refers to production of magnetic fluids based on wide class of silicon-organic media: polymethyl-, polymethylphenyl-, polyethyl-, polymethylphenyl-, polyorganohalogenosiloxane fluids which are used in various gears of magneto-liquid seals. For stabilization of magnetite in liquid medium there are used silicon-organic trimethyl ethylsilicates, amines instead of oleic acid (second surface-active substance). In the capacity of first surface-active substance water-solved complex BHX-40B is used which is produced by simple condensation of phenol, diethylamine, fatty acids of fraction C₁₀-C₁₆ and formaldehyde taken in molar proportion 1:2: 1:1.5. First surface-active substance is sorbed on particles of aqueous magnetite making its surface lyophilic which makes it possible to extract magnetite from aqueous phase into solution of silicon-organic oligomeres in liquid medium with separation of aqueous solution of first surface-active substance. EFFECT: wide range of magnetization from 15 to 60 KA/m, high thermal stability and lesser viscosity within range of low temperatures.