Abstract: A process for producing a magnetic recording medium is described comprising applying to a support a coating solution which has ferromagnetic particles dispersed in a solution comprising a binder curable by electron beams and a low-boiling point solvent, irradiating the support with electron beam radiation while the particles remain dispersed uniformly, and evaporating the solvent to dryness.

Abstract: A magnetic recording medium and, more particularly, a magnetic recording medium based on a magnetic composition exhibiting high dispersibility of finely divided ferromagnetic powders and having excellent abrasion resistance is disclosed wherein the binder for the magnetic composition contains a 2-chloroacrylonitrile polymer and a thermoplastic polyurethane resin; in another embodiment of the invention the binder additionally contains a polyisocyanate.

Abstract: A recording medium and, more particularly, a recording medium based on a composition exhibiting high dispersibility for finely-divided ferromagnetic powders having excellent abrasion resistance is disclosed in which the magnetic composition comprises a finely-divided ferromagnetic powders dispersed in a binder containing 2-chloroacrylonitrile polymer and a polyurethane prepolymer; in another embodiment of the invention the magnetic composition additionally contains a polyisocyanate compound.

Abstract: A view finder for a single-lens reflex camera has a notch formed in the light exit face of a view finder prism outside of the area through which photographic light rays are passing. At the notch, a reflection member guides rays of light representing photographic data and passing through the inside of the view finder prism toward an eyepiece.

Abstract: A magnetic recording medium comprising a plastic film support having a magnetic recording layer on one side is provided with a backing layer containing: (1) a white and/or light colored powder; (2) carbon black and/or graphite; and (3) a polymeric binder. The backing layer transmits more than 3% of white light at a thickness of 2 microns and has a surface electrical resistance of less than 10.sup.10 .OMEGA./cm. Pinholes and drop-out are easily detected in forming such a magnetic recording medium.

Abstract: A method of producing a magnetic recording layer on a support comprising simultaneously depositing a ferromagnetic material and a polymer on a support using a vapor deposition technique such as vacuum deposition, sputtering, etc., thereby to produce thereon a magnetic recording layer of a composite film of the ferromagnetic material and the polymer. A further embodiment for producing a magnetic recording layer comprises simultaneously depositing a ferromagnetic material and a monomer or oligomer on the support using a vapor deposition technique, polymerizing the deposited layer, e.g., using a polymerization catalyst or by applying ionizing or electromagnetic rays thereto, to form a composite film of the ferromagnetic material and the polymer. The magnetic recording layer thus obtained in either embodiment can be used for high density recording.

Abstract: The inner surface of a disc jacket for retaining a magnetic recording disc is provided with a fibrous layer containing an antistatic agent. The fibrous layer is composed of a nonwoven cloth impregnated with the antistatic agent. The antistatic agent may be applied to the nonwoven cloth by spraying instead of impregnation.

Abstract: A process of producing a magnetic recording element comprising a non-magnetic support having provided thereon a subbing layer and further having provided thereon a magnetic layer comprising a ferromagnetic powder and a binder, in which the non-magnetic support is a biaxially stretched polyester and the subbing layer is formed by coating a coating solution having a solids concentration of about 0.8 to about 5 wt% comprising an amorphous linear saturated polyester resin containing an aromatic dicarboxylic acid, 10 to 50 wt% of a vinylidene chloride addition polymerizable nitrile copolymer based on the polyester resin and an organic solvent mainly composed of methyl ethyl ketone, which comprises coating the subbing solution at a temperature of about 100.degree. C. or below to provide a dry thickness of about 0.03 to about 2.0 .mu.m, drying the coated layer and then coating the magnetic recording layer thereon.

Abstract: A process for producing a magnetic recording medium with a magnetic recording layer comprising coating a magnetic coating composition comprising mainly a ferromagnetic powder, a binder, and a predominantly aqueous coating solvent on a nonmagnetic support and then drying, wherein the binder contains a water-soluble or water-dispersible amide compound. In a particularly preferred embodiment, the binder also contains an epoxy compound containing on the average one or more adjacent epoxy groups in the molecule.

Abstract: A magnetic recording medium comprising a non-magnetizable plastic film support having a magnetic recording layer on one side thereof and, on the other side thereof, a layer containing (1) at least one powder of carbon black or graphite, and (2) at least one powder of a white pigment or a light colored pigment, and (3) a binder, powders (1) and (2) forming divided color areas in the back surface layer, and the back surface layer having a surface electrical resistance below 1 .times. 10.sup.10 ohm/cm.sup.2.

Abstract: A cleaning jacket for a magnetic head used for flexible discs comprising a cleaning sheet and a sheet retaining jacket, the cleaning sheet comprising a flexible and non-magnetizable support, at least on one surface of which is provided an antistatic layer and on the other surface of which is provided a cleaning layer of a fibrous material, the retaining jacket having the shape of a flat casing and defining a space in which the cleaning sheet can be kept in such a manner that it can rotate freely therein, and, further, having a lubricating layer provided on the inner wall thereof facing the antistatic layer of the cleaning sheet.

Abstract: This invention relates to a method of forming a metallic thin film on a plastic substrate by electroless plating, which comprises providing an undercoated layer consisting essentially of polyvinylidene chloride or vinylidene chloride copolymer on the surface of the plastic substrate and then subjecting to a surface activating treatment and electroless plating.

Abstract: A magnetic recording medium comprising a support having thereon a magnetizable recording layer containing a ferromagnetic powder dispersed in a binder, said magnetizable recording layer containing a silane coupling agent.

Abstract: Magnetic recording tapes having an excellent durability are obtained by using as a binder for ferromagnetic powders on a base film or sheet an intimate mixture of (1) a vinyl chloride-vinyl acetate copolymer, (2) an organic polyisocyanate and (3) a reactive acrylic resin having a carboxyl group content of from 1 to 30% by weight which will react through the carboxyl groups with the polyisocyanate compound into a crosslinked cured state.

Abstract: A process for stabilizing a ferromagnetic material comprising heat-treating a needle-like ferromagnetic material represented by the formula MO.sub.x wherein M is a ferromagnetic metal ion or a ferromagnetic non-metal ion and another metal ion, and x is the degree of oxidation which ranges from 1.36 to 1.47, and containing at least 0.5 atom % Co, at a temperature of at least about 40.degree. C, and a process for stabilizing a magnetic recording member comprising heat-treating a magnetic recording member produced by providing a ferromagnetic recording layer comprising (a) a ferromagnetic material represented by the formula MO.sub.x wherein M and x are the same as defined above, and containing at least 0.5 atom % Co, and (b) a binder, on a support, at a temperature of at least about 40.degree. C.

Abstract: A magnetic recording member comprising a non-magnetic support having a magnetic recording layer on one side of the non-magnetic support and a lubricating layer on the other side of the non-magnetic support in which the lubricating layer comprises a liquid or semi-solid lubricant or a liquid or semi-solid lubricant, and an organic binder.