| abstract |
PURPOSE: To improve the dispersibility of magnetic powder by using polyurethane, which has not less than three hydrc radicals in all at random positions of molecular ends and molecular chains, as binder components of the magnetic powder applied on a base. n CONSTITUTION: Polyurethane resin, which has not less than three hydroxyl radicals at random points of molecular ends and molecular chains and is about 10,000W 100,000 in molecular weight, is used in addition to polyisocyanate at need to obtain binder components, which are mixed and dispersed in an adequate organic solvent together with magnetic powder of Fe 2 O 3 containing Co, etc. This magnetic coating is applied on a base of a polyester film, etc., and then dried. Consequently, the magnetic powder is excellently dispersed into the magnetic coating in a short time. A magnetic recording medium can therefore be obtained which has superior electromagnetic conversion characteristics, durability, etc. n COPYRIGHT: (C)1980,JPO&Japio |