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 comprising a coated magnetic recording layer having video and chroma S/N ratios appropriately balanced with tape transporting characteristics is attained by controlling the magnetic layer to have a surface roughness such that the maximum value of the arithmetical average roughness (Ra) is about 80 A or greater in the surface roughness pitch region greater than about 300 .mu.m while in the surface roughness pitch region of about 5 .mu.m to about 100 .mu.m the maximum value of the arithmetical average roughness (Ra) is about 40 A or less.

Abstract: In a supercalender consisting of a metal roll and an elastic roll and smoothing a web by nipping the web between the metal roll and the elastic roll, the elastic roll satisfies the condition of:Hs(D).gtoreq.-0.1T+85under the condition of 50 to 500 kg/cm of the linear pressure between the metal roll and the elastic roll, where Hs(D) is Shore hardness D-scale of the elastic roll and T is the working temperature (.degree.C.) of the elastic roller that satisfies the condition of 60.gtoreq.T.gtoreq.120.

Abstract: A magnetic recording element comprising a magnetic recording layer on a surface of a synthetic resin support and an antistatic layer on the opposite surface of said synthetic resin support, wherein said antistatic layer comprises a powder of a white or light-colored pigment and a powder of a carbon type electrically conductive substance in a binder, said pigment powder being substantially all in the outer surface portion of said antistatic layer and said electrically conductive powder being substantially all in the portion of said antistatic layer adjacent said support is disclosed.

Abstract: The present invention relates to a leader or trailer tape for a magnetic tape, which comprises a plastic support member and, on one side thereof, a laminated coating consisting of at least (1) an electrically conductive layer as a first layer and (2) a layer containing mainly a pigment and a binder as a second layer.

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: This invention relates to a magnetic recording medium which comprises a support having a surface roughness of at most 0.35 micron, a magnetic recording layer on one side of the support and a lubricant layer containing a lubricant represented by the following general formula, ##STR1## in which R=C.sub.n H.sub.2n+1, n=12-18, x=0-8 and y=1-50 and being coated onto the opposite side to the magnetic recording layer with a mean coating quantity of 1 to 500 mg/m.sup.2.

Abstract: A magnetic recording medium with a greatly reduced coefficient of friction comprising a non-magnetic support having thereon a magnetic recording layer comprising finely divided ferromagnetic powders in a binder, wherein(1) at least one alkylpolysiloxane having a hydrophilic group in the side chain thereof and represented by the formula (I) ##STR1## wherein R.sub.1 and R.sub.2, which may be the same or different, each represents ##STR2## provided that R.sub.1 and R.sub.2 are not simultaneously --CH.sub.3 ; R.sub.3 represents --CH.sub.3 or the aliphatic chain having 10 to 18 carbon atoms of a saturated or unsaturated fatty acid; R.sub.4 represents --H or --CH.sub.3 ; Z represents an ionic group, which renders the alkylpolysiloxane water-soluble, selected from the group consisting of --OSO.sub.3 Na, --COOR.sub.5 wherein R.sub.

Abstract: The present invention relates to a leader or trailer tape for a magnetic recording medium, which comprises a non-magnetic flexible support having a surface roughness of at least 0.15 .mu.m, at least one side thereof being optionally subjected to a surface activating treatment, and a transparent and electrically conductive metal oxide layer provided thereon.

Abstract: This invention relates to a leader or trailer for a magnetic tape, which comprises a plastic support member, a coated layer consisting essentially of a pigment and binder on the surface of the plastic support and a lubricant layer on the back side of the plastic support, the pigment consisting of a mixture of at least two solid powders each having a mean grain size of (A) 0.002 to 3 microns and (B) 5 to 35 microns and the lubricant layer being coated in a proportion of at least 0.1 mg/m.sup.2.

Abstract: In a magnetic recording substance comprising a non-magnetic support member and a magnetic recording layer provided thereon and consisting essentially of a ferromagnetic powder and a binder, the content of calcium component contained in the ferromagnetic powder is previously adjusted to 0.001% by weight or less.

Abstract: A cleaning tape used for cleaning the surface of a magnetic recording head of a tape recorder or the like consists of a substrate and a cleaning layer. The cleaning layer contains two kinds of particles. One kind of particles has a small diameter and a high hardness, and the other has a large diameter and a low hardness.

Abstract: In a magnetic recording substance comprising a magnetic recording layer on one side of a non-magnetic support and a back layer on the other side thereof, the back layer is provided by coating a powdered solid with a binder and coating solvent and having spike grains with a height of 0.8 to 5 microns and an interval or pitch of at least 200 microns on the surface thereof and a friction coefficient of at least 0.25.

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: In a magnetic recording substance comprising a non-magnetic support and a magnetic recording layer provided on the support, carbon black having a surface area of at least 700 m.sup.2 /g and an oil absorption of at least 300 ml (DBP)/100 g is contained in the magnetic layer thereby lowering the surface electric resistance without deteriorating the characteristics of the magnetic recording layer.

Abstract: In a method for super calendering a magnetic recording element comprising a non-magnetic flexible support having provided thereon a magnetic layer mainly composed of ferromagnetic powders and a binder using a super calendering roll assembly having a metal roll in contact with the magnetic layer side and an elastic roll in contact with the support side opposite the metal roll, which comprises pressing the surface of the magnetic layer to thereby super calender the same, at least the surface area of the elastic roll comprises a polyamide resin having a Shore hardness D of at least about 70 and having a linear expansion coefficient of at least about 8 .times. 10.sup.-5 /.degree. C.

Abstract: By incorporating 5 to 15 parts by weight of a finely divided powder having high hardness and a particle size of less than 10.mu. with 100 parts by weight of graphite powder with 20 to 50 parts by weight of a binder in a graphite layer of a magnetic recording medium which comprises a support, a magnetizable layer and a graphite layer provided on the opposite side of the support from the magnetizable layer, a reduction in the abrasion and the destruction of the graphite layer during running can be reduced.

Abstract: A magnetic sound track layer can be formed with good adherence on the emulsion layer of a photographic material for motion picture film by coating from a liquid composition comprising ferromagnetic powders, a binder, and at least 1% by weight, based on the weight of said ferromagnetic powders, of p-toluenesulfonic acid and at least 3% by weight, based on the weight of said powder of glacial acetic acid. A motion picture film where the magnetic sound track contains p-toluenesulfonic acid and glacial acetic acid.

Abstract: A magnetic recording material which comprises a support having thereon a magnetic recording layer comprising a ferromagnetic substance and a binder, wherein the ferromagnetic substance comprises a mixture of (1) a Berthollide iron oxide having a particle size of about 0.5 .mu. or larger and a degree of oxidation represented by the value of x in FeO.sub.x of 1.33<x.ltoreq.1.45 and (2) a Berthollide iron oxide having a particle size of about 0.4 .mu. or smaller and a degree of oxidation represented by the value of x in FeO.sub.x of 1.43.ltoreq. x< 1.50, in which the weight ratio of Berthollide iron oxide (1) to Berthollide iron oxide (2) ranges from about 1:4 to 4:1.