| 摘要 |
PURPOSE: To produce spherical fine particles having magnetic transfer properties used in the display of a character or an image by reversing spherical fine particles each consisting of a magnetic semispherical part and a non-magnetic semispherical part by a magnetic pen. CONSTITUTION: A magnetic resin compsn. (A) prepared by compounding magnetic particles and a coloring agent with a thermoplastic synthetic resin and a non-magnetic resin compsn. (B) prepared by compounding an inorg. filler and a coloring agent with a thermoplastic synthetic resin and adjusted to the same specific gravity as the magnetic resin compsn. are respectively melted and kneaded by two extrusion molding machines and the molten compsns. (A), (B) are allowed to meet with each other in a die so as to become two layers and extruded to be subjected to hot cutting in water. |
