Abstract: A magnetic recording material, which comprises a magnetic layer coated on a non-magnetic support is disclosed. The magnetic layer contains both carbon black fine powder having a mean primary grain size of less than 10 m.mu. and carbon black coarse powder having a mean primary grain size in the range of 50 to 120 m.mu. in a mixing ratio ranging from 95/5 to 5/95. The material is improved in both RF output and audio output.

Abstract: A novel magnetic recording medium comprising a non-magnetic support, a magnetic recording layer, and an intermediate layer containing an electroconductive polymer. An optional second intermediate layer contains carbon black and is provided on either surface of the first intermediate layer. The magnetic recording medium has low surface electric resistance, and when used as a video tape, has both a high video S/N ratio and improved stability of video S/N with the passage of time.

Abstract: This invention relates to a magnetic recording medium whose coefficient of friction is lowered without lowering S/N and which has an improved running property, which comprises a magnetic recording layer on one side of a nonmagnetic support and a back layer containing an inorganic powder and a binder and having a thickness of at most 2.mu., on the other side thereof, characterized in that the surface of the back layer is provided with surface projections with a height of 0.05 to 0.8.mu., an interval of at least 50.mu. and 50 to 50,000 projections/cm.sup.2.

Abstract: A magnetic recording medium is disclosed which comprises a non-magnetic support having provided thereon a magnetic recording layer consisting ferromagnetic powder and containing graphite and a fatty acid ester.

Abstract: A magnetic recording medium is disclosed, which comprises a non-magnetic support having, on opposite surfaces thereof, a magnetic recording layer containing magnetic particles and a backing layer containing carbon black and other inorganic particles and a binder having a thickness of not more than 2.mu., the backing layer containing (a) carbon black having an average particle size of 60 to 120 m.mu. and (b) other inorganic particles having an average particle size of 20 to 100 m.mu..

Abstract: A magnetic recording medium is disclosed. The medium comprises a non-magnetic support having provided on opposite surfaces a magnetic recording layer and a backing layer containing two types of carbon black and a binder and having a thickness of 2 .mu.m or less, one of said carbon black being fine carbon black having an average particle size of 30 to 100 m.mu. and the other of said carbon black being coarse carbon black having an average particle size of 150 to 500 m.mu., and the mixing weight ratio of said carbon black and the binder being 1:1.5 to 1:3.5.

Abstract: A magnetic recording medium comprising a non-magnetic support, a magnetic layer on a surface of the non-magnetic support, and a backing layer on a reverse surface of the non-magnetic support, composed of powder and a binder, and having a thickness of not more that 2 microns, wherein said powder comprises TiO.sub.2 powder and carbon black powder in the weight ratio of 4:6 to 10:0. The average particle size of TiO.sub.2 powder ranges from 0.01 to 0.8 microns.

Abstract: A magnetic recording medium which comprises a non-magnetic support having on the surface side thereof a magnetic recording layer and on the opposite side thereof a backing layer having a thickness of 2 .mu.m or less, which contains carbon black and a binder and optionally, an inorganic powder, in which the backing layer contains at least two kinds of carbon black, one being fine-grained carbon black having a mean grain size of 10 to 30 m.mu. and the other being coarse-grained carbon black having a mean grain size of 150 to 500 m.mu. such that the weight ratio (P/B) of the total amount of carbon black and inorganic powder (P) to binder (B) is from about 1/0.5 to 1/3.5. The recording medium described provided smooth and stable tape-running for an extended period and a high S/N ratio.

Abstract: A magnetic recording medium comprising a support having provided thereon a magnetic recording layer containing (1) a cobalt-containing iron oxide, (2) graphite, and (3) a copolymer of vinyl chloride, vinyl acetate and maleic acid.

Abstract: A magnetic recording medium is disclosed which comprises a non-magnetic support, having a Young's modulus of 7.times.10.sup.10 to 1.times.10.sup.13 dyn/cm.sup.2, having coated on opposite surfaces, a magnetic recording layer comprising ferromagnetic particles and a fatty acid ester and a backing layer comprising a cellulose resin.

Abstract: A magnetic recording medium is disclosed which comprises a non-magnetic support having provided on opposite surface thereof a magnetic recording layer, and a backing layer containing carbon black and a binder, said carbon having an average particle size of not less than 150 m.mu. and the weight ratio of carbon black and the binder being 1:3.0 to 1:10.

Abstract: A method for preparing a magnetic recording medium is described, comprising (1) pre-dispersing ferromagnetic particles having an S.sub.BET specific surface area of 35 m.sup.2 /g or more and having an adjusted water content of 0.8 wt % or more with a binder, (2) adding an additional binder and a lubricating agent thereinto, mixing and dispersing them to prepare a diserpsion of a magnetic coating composition, and (3) coating the resulting dispersion of a magnetic coating composition on a non-magnetic support.

Abstract: A magnetic coating composition comprising a binder dissolved in a solvent and magnetic grains dispersed therein is applied onto a surface of a non-magnetic substrate continuously moved. The coating film thus overlaid on the non-magnetic substrate is subjected to a preliminary orientation step for orientating the magnetic grains in the coating film, and then to a preliminary drying step. A final orientation step is then conducted while intermediate drying is carried out. Thereafter, final drying is effected.

Abstract: A process for the production of magnetic recording media including a nonmagnetic support having a magnetic layer on one side thereof, and a backing layer obtained by dispersing a filler in a binder on the other side thereof, in which said backing layer is provided by:a first step of kneading and dispersing a filler and a binder by means of a roll mill to form chips,a second step of dissolving said chips in a solvent followed by dispersion effected with a sand grinder, anda third step of adding a curing agent to the obtained liquid dispersion, followed by coating.

Abstract: A magnetic recording material is disclosed which is comprised of a single magnetic layer comprised of plate-shaped ferromagnetic particles wherein the plate-shaped ferromagnetic particles are present in greater number in the surface part of the magnetic layer than in the inner part and/or the plate-shaped ferromagnetic particles are aligned such that an average horizontal axis component of the particles with respect to the surface of magnetic layer is larger in the surface part than in the inner part. The location and alignment of the particles make is possible to increase output with short-wave recording.

Abstract: A magnetic recording medium comprised of a non-magnetic support base having provided thereon a magnetic recording layer is disclosed. The medium also has position thereon a compound selected from the group consisting of carboxylic acids and carboxylic acid derivatives, the compound being present on an edge portion of the medium. The medium also includes an additional lubricant on the middle part of the medium, the additional lubricant being selected from the group consisting of alphatic acid esters, alphatic acids, silicons and phosphoric acid esters. By utilizing two different types of lubricants on different portions of the medium it is possible to obtain improved lubricating properties and thus improve runnability with respect to the operation of the magnetic recording medium.

Abstract: This invention provides a magnetic recording medium, in particular, magnetic recording tape whose coefficient of friction is decreased and running durability is improved without deteriorating the S/N property, which comprises a magnetic layer on one side of a support and a back layer on the other side thereof, the back layer containing a filler dispersed in a binder, characterized in that the binder consists essentially of a cellulose resin, a diolefin- or olefin-type synthetic rubber and a polyisocyanate.

Abstract: A magnetic recording medium is disclosed which is comprised of a non-magnetic support having a magnetic layer provided thereon. The magnetic layer is comprised of two different types of carbon black having different particle sizes, a lubricant which is liquid at room temperature, a ferromagnetic powder all dispersed in a binder. A carbon black (1) has an average particle size smaller than 50 m.mu. and a carbon black (2) has an average particle size of larger than 120 m.mu.. The carbon black is present in a weight ratio of (1)/(2) within the range of 50/50 to 97/3. The magnetic recording medium has improved electromagnetic properties and running durability. In addition, the material provides an improved S/N ratio and an improved coefficient of friction.

Abstract: A magnetic recording medium is disclosed. The medium is comprised of a non-magnetic support having coated thereon a magnetic recording layer and a backing layer on the surface opposite the magnetic recording layer. The backing layer contains carbon black and the surface treated calcium carbonate dispersed in a binder. The calcium carbonate is surface treated so as to make the particles hydrophobic. Including the carbon black and the calcium carbonate in the backing layer provides a recording medium with improved durability and a reduced amount of drop out.

Abstract: The present invention relates to a leader or trailer tape to be connected with a magnetic tape, which comprises a support base and two coating layers containing solid powders provided on the surface side and back side of the support base, the surface roughness of the one coating layer on the surface side being finer than that of the other coating layer on the back side, the surface roughness of the former being about 0.05 to 2 microns and that of the latter being about 0.5 microns or more.