RUBBER MAGNET

PURPOSE:To obtain a rubber magnet, having very low staining properties, which can be used over a wide range covering the field system of all kinds of micromotors, relay magnets and the like by a method wherein the gas in the region pinched by the peaks of the normal hydrocarbon C14H30 and C32H66 on a gas chromatogram, is brought to a fixed quantity or less. CONSTITUTION:The title rubber magnet consists of magnetic powder, rubber, a dispersant of magnetic powder and an organic peroxide crosslinking agent, and among the gases volatilizing from the surface of the rubber magnet when it is heated up to 115 deg.C, the total weight of the gas in the region pinched by the peaks of the normal hydrocarbon C14H30 and C32H66 on a gas chromatogram is limited to 0.6ppm/min or less per unit weight of the rubber magnet. In this rubber magnet, the composition of volatile gas has low staining properties, and the occurrence of contamination on a brush and a commutator can be prevented substantially even when the rubber magnet is used in a micromotor having high degree of airtightness.