Abstract: To manufacture a magnetic recording medium with reduced coating defects by effectively and reliably removing foreign matter that causes coating striations.In a manufacturing method for a magnetic recording medium that includes a process in which a magnetic layer is formed on a flexible support, the aforementioned magnetic layer is formed after cleaning the aforementioned flexible support by bringing it into contact with a rotating cleaning roll, the contact surface of which consists of at least an adhesive substance or with a cleaning member, the contact surface of which consists of at least a porous polymer and so providing a manufacturing method for a magnetic recording medium in which foreign matter, which causes coating striations, can be efficiently and reliably removed and in which it is possible to manufacture a magnetic recording medium with reduced coating defects.

Abstract: A printing ink for printing slightly adhesive plastic bases, especially polyoxymethylenes and polypropylenes, comprises an ultraviolet-curing ink and an isocyanate compound added thereto. The isocyanate compound is added in an amount of 0.5 to 35 parts by weight per 100 parts by weight of the ultraviolet-curing ink. The invention relates also to printed matter on which given characters, figures, or/and patterns have been printed using such an ultraviolet-curing ink. The invention relates further to a printing method for giving such printed matter. The printing is preceded by a pretreatment selected from among corona discharge, shortwave ultraviolet radiation, and electron radiation.

Abstract: In a magnetic recording medium comprising a substrate and a magnetic layer thereon, the magnetic layer is formed by coating a composition of a binder, preferably radiation-curable binder and a needle magnetic material, passing the coating through a magnetic field to forcedly re-orient the magnetic particles to form pores having an average pore area of 6.times.10.sup.-5 to 7.times.10.sup.-1 .mu.m.sup.2, and curing the coating, thereby minimizing output fluctuation and improving durability. Preferably lubricant is present in the pores.

Abstract: A magnetic recording medium, consisting of a base coated with a magnetic coating material, uses as a binder a polyurethane resin having a metal sulfonate group, a vinyl chloride-vinyl acetate copolymer containing not less than 8% vinyl alcohol on the basis of the total binder weight, and nitrocellulose, in which magnetic particles are dispersed. The binder may contain an isocyanate compound as a crosslinking agent for added particle dispersibility.

Abstract: A magnetic recording medium is composed of a base and a magnetic coating which comprises a binder and a magnetic powder dispersed therein. The magnetic powder, in turn, contains a nonmagnetic powder having an average particle size of not more than 2 .mu.m and a hardness of at least 6 on Mohs scale, in an amount of 1-20% on the basis of the weight of the magnetic powder, and the binder contains a resin such as polyester resin having a group expressed by the formula --SO.sub.3 M where M is monovalent metal such as Na.