Abstract: The magnetic coating composition of the invention comprises ferromagnetic particles having a specific surface area of at least 35 m.sup.2 /g dispersed in a resinous vehicle which is a polyvinyl chloride-based copolymeric resin composed of five types of monomeric moieties including (a) a moiety of vinyl chloride, (b) a moiety of vinyl alcohol, (c) a moiety of a vinyl carboxylate having from 6 to 20 carbon atoms in a unit, (d) a moiety of a vinyl or allyl monomer having a sul-fonic acid group or a sulfonic acid group in the form of a metal salt in the molecule, and (e) a moiety of a vinyl or allyl monomer having an epoxy group in the molecule. This vehicle resin is advantageous in respect of the dispersibility of the ferromagnetic particles to greatly facilitate the coating operation due to the relatively low viscosity of the coating composition as compared with conventional resins.

Abstract: The invention provides a magnetic coating composition capable of giving a magnetic recording medium having improved properties in respect of the dispersibility of the ferromagnetic particles in the vehicle resin and the surface properties of the magnetic recording medium coated therewith. The inventive magnetic coating composition is characteristic in the use of a specific vehicle resin having a polymeric molecular structure composed of the monomeric units of vinyl chloride, vinyl alcohol, amine-modified vinyl and, optionally, vinyl carboxylate and epoxy-containing a monomer in specified proportions.