Abstract: A magnetic recording medium is disclosed, which comprises a non-magnetic support having on one surface of the support a backing layer containing carbon black and a binder and on the opposite surface of the support a magnetic recording layer containing a ferromagnetic power and a binder, the ferromagnetic powder being oriented in the magnetic recording layer such that the ratio of the number of diffraction points N(220)/N(113) measured at the surface region of the magnetic layer by high energy electron diffraction is at most 1.65; and the squareness ratio Br/Bm of the magnetic layer is from 0.830 to 0.860 at 25.degree. C. The medium has excellent running durability, S/N ratio, and dropout properties.

Abstract: A magnetic recording medium composed of a non-magnetic support having thereon at least one magnetic layer containing a ferromagnetic fine powder dispersed in a binder, wherein (a) the magnetic layer further contains at least one of (i) carbon black having a sodium content of at most 100 ppm, (ii) carbon black having a chlorine content of less than 400 ppm, and (iii) an abrasive having a Mohn' hardness of at least 8 and a mean particle size of 0.05 to 0.5 .mu.m and a sodium content of at most 100 ppm; (b) the ferromagnetic fine powder is a magnetic metal powder having a sodium content of at most 200 ppm; and/or (c) the magnetic recording medium further has a back layer provided on the side of the non-magnetic support opposite to the magnetic layer, containing carbon black having a chlorine content of at most 300 ppm dispersed in a binder. The magnetic recording medium has superior storage stability, with remarkably limited dropout increase, head clogging, C S/N decrease and RF output decrease.

Abstract: A magnetic recording medium comprising a nonmagnetic support having formed thereon a magnetic layer containing a ferromagnetic fine powder, a binder, and carbon black and formed on the opposite side of the nonmagnetic support to the magnetic layer-carrying side a backing layer containing a binder and carbon black, wherein (i) the Young's modulus of the magnetic layer is from 600 to 1100 kg/mm.sup.2 and the Young's modulus of the backing layer is from 200 to 400 kg/mm.sup.2, or (ii) the surface free energy of the backing layer is at least 1 dyn/cm higher than the surface free energy of the magnetic layer, the gloss of the magnetic layer is at least 150, and the gloss of the backing layer is from 2 to 7.

Abstract: A magnetic recording medium comprising a nonmagnetic support having on one surface thereof a magnetic layer and on the opposite surface thereof a backing layer comprising nonmagnetic particles dispersed in a binder, wherein said binder of said backing layer comprises from about 20 to 90 wt % of polycarbonate polyurethane, and said backing layer comprises from about 40 to 200 parts by weight of said binder per 100 parts by weight of said nonmagnetic particles.

Abstract: A magnetic recording medium having excellent running properties and excellent durability is disclosed, which comprises a non-magnetic support having thereon a magnetic layer comprising a ferromagnetic powder and carbon black, said carbon black being a mixture which contains high structure furnace carbon black and acetylene black in the weight ratio of the former to the latter of from 95:5 to 45:55, and said high structure furnace carbon black having properties satisfying the general equations (I) or (II) below:0<X.ltoreq.120, Y.gtoreq.0.625X+75 (I)X>120, Y.ltoreq.0.01125X.sup.2 -2.005X+229 (II)wherein Y is the amount of DBP oil absorbed (Ml/100 grams) by said high structure carbon furnace black, X is the specific surface area (m.sup.2 /gram) of said high structure carbon furnace black, and Y.gtoreq.120, wherein W is the amount of DBP oil adsorbed (ml/100 grams) by said actylene black, Z is the specific surface area (m.sup.2 /gram) of said acetylene black, and W.gtoreq.120.

Abstract: A magnetic recording medium comprising a support having provided on one surface thereof a magnetic layer comprising a binder and ferromagnetic particles dispersed therein, and on the opposite surface thereof a backing layer comprising a binder and non-magnetic particles dispersed therein, wherein at least one of the binders comprises a vinyl chloride copolymer resin having a vinyl chloride unit content of about 70 wt % or more based on the total amount of the binder, a nitrogen content of about from 0.01 to 1 wt % based on the total amount of the binder, and a polymerization degree of about from 250 to 700; and the non-magnetic particles comprises fine carbon particles having a DBP oil absorption of about 150 ml/100 g or more.

Abstract: A magnetic recording medium comprising a support having provided on one surface thereof a magnetic recording layer containing ferromagnetic particles dispersed in a binder and on the other surface thereof a backing layer, wherein said binder comprises a vinyl chloride/vinyl acetate copolymer reisn containing at least one group represented by formula (I) or (II): ##STR1## wherein X represents a --COO-- group, a --CONH-- group, or a --C.sub.6 H.sub.4 -- group; x represents an integer of from 1 to 10; R.sub.1, R.sub.2, and R.sub.3 each represents a hydrogen atom, an alkyl group having from 1 to 10 carbon atoms, or an alkyl derivative having from 1 to 10 carbon atoms, or R.sub.1, R.sub.2, and R.sub.3 may be combined to each other to form a heterocycric ring; and Y.sup..crclbar. represents a halogen atom, ClO.sub.4.sup..crclbar., or HgI.sub.3.sup..crclbar. ; or Y.sup..crclbar. is bound to R.sub.2, R.sub.2 represents an alkylene group having from 1 to 10 carbon atoms, and Y.sup..crclbar. represents a --COO.sup..

Abstract: A magnetic recording medium comprising a support having provided on one surface thereof a magnetic recording layer and on the other surface thereof a backing layer containing non-magnetic particles dispersed in a binder, wherein said binder comprises a vinyl chloride/vinyl acetate copolymer resin containing at least one group represented by formula (I) or (II): ##STR1## wherein X represents a --COO-- group, a --CONH-- group, or a --C.sub.6 H.sub.4 -- group; n represents an integer of from 1 to 10; R.sub.1, R.sub.2, and R.sub.3 each represents a hydrogen atom, an alkyl group having from 1 to 10 carbon atoms, or an alkyl derivative having from 1 to 10 carbon atoms, or R.sub.1, R.sub.2, and R.sub.3 may be combined to each other to form a heterocycric ring; and Y.sup..crclbar. represents a halogen atom, ClO.sub.4.sup..crclbar., or HgI.sub.3.sup..crclbar. ; or Y.sup..crclbar. is bound to R.sub.2, R.sub.2 represents an alkylene group having from 1 to 10 carbon atoms, and Y.sup..crclbar. represents a --COO.sup..

Abstract: A magnetic recording medium is described, comprising a non-magnetic support having provided thereon a magnetic layer containing ferromagnetic particles and a binder, said binder of the magnetic layer containing polyisocyanato-isocyanurate as a hardening component.

Abstract: A magnetic recording medium is disclosed, comprising a non-magnetic support having thereon a magnetic layer comprising ferromagnetic fine particles, a binder, and .alpha.-alumina particles having an average size of from about 0.1 to 0.3 .mu.m, provided that the number of .alpha.-alumina particles having a particle size of larger than 0.05 .mu.m is at least equal to the number of .alpha.-alumina particles having a particle size of up to 0.05 .mu.m.

Abstract: The present invention relates to a magnetic recording medium which comprises a non-magnetic support having coated on opposite surfaces thereof a magnetic layer and a backing layer comprising a resin as a binder and non-magnetic particles, wherein the resin binder contains a polyurethane resin, a copolymer of vinylidene chloride and acrylonitrile, and a polyisocyanate compound; the non-magnetic particles contains fine carbon black having an average particle size of 30 to 150 m.mu. and coarse carbon black having an average particle size of 160 to 600 m.mu.; and the mixing weight ratio of the resin binder to the non-magnetic particles is within the range of 0.375:1 to 1:1 by weight. This magnetic recording medium has excellent electromagnetic properties and running durability.

Abstract: A magnetic recording medium is described, comprising a non-magnetic support base having positioned thereon a magnetic layer and optionally a non-magnetic layer, wherein at least one layer of the magnetic and non-magnetic layers contains an oxyfatty acid ester. This recording medium has superior surface properties and thus superior running properties, and can be satisfactorily used in tape decks.

Abstract: A magnetic recording medium comprising a non-magnetic support having provided thereon a magnetic layer being provided on one surface of the support and a backing layer being provided on the surface of the support opposite to said magnetic layer, the backing layer contains binder and non-magnetic particles comprised of (i) corbon black having an average particle size of 0.1 to 1.0 .mu.m and (ii) particles of abrasives having a Mohs' hardness of at least 6 and an average particle size of 1 .mu.m or less, with the non-magnetic particles in said backing layer being used in an amount of 40 to 300 parts by weight per 100 parts by weight of binder.

Abstract: A magnetic recording medium is described, comprising a magnetic layer containing ferromagnetic fine particles and a binder coated on one side of a non-magnetic support and a backing layer coated on the opposite side of the non-magnetic support, wherein said ferromagnetic fine particles have a cobalt content of from 2 to 10 wt % with respect to the iron oxide content thereof, the content of divalent iron (Fe.sup.2+) of from 1 to 10 wt % with respect to the trivalent iron (Fe.sup.3+) content thereof, and the specific surface area of from 30 to 50 m.sup.2 /g, said binder comprises a copolymer of vinyl chloride-vinyl acetate-maleic acid contained in an amount of 40 wt % or more with respect to the total binder content of the magnetic layer, an abrasive agent having a Mohs hardness of 6 or more is contained in said magnetic layer, and the resulting magnetic tape has a coercive force of from 750 to 900 Oe at 25.degree. C.

Abstract: A magnetic recording medium is described, comprising a magnetic layer coated on one side of a non-magnetic support and a backing layer coated on the opposite side of the non-magnetic support, wherein the backing layer is provided after the magnetic layer has been subjected to calendering treatment and the backing layer comprises (i) non-magnetic particles including carbon black particles having an average particle diameter of from 0.1 to 1 .mu.m and (ii) a binder composition comprising from 50 to 95 wt % of a resin having a 100% modulus at 150 kg/cm.sup.2 or less based on the total weight of the binder composition, and the weight ratio of non-magnetic particles to binder composition contained in the backing layer is from 300/100 to 40/100.

Abstract: A magnetic recording medium is described, comprising a non-magnetic support having provided thereon a magnetic layer being provided on one surface of the support and a backing layer being provided on the surface of the support opposite to said magnetic layer, the backing layer containing (A) a binder comprised of resin having a 100% modulus of 150 kg/cm.sup.2 or less present in an amount of 50 to 95 wt % based on the total weight amount of binder and (B) non-magnetic particles comprised of (i) carbon black having an average particle size of more than 0.1 .mu.m to 1.0 .mu.m, and (ii) carbon black having an average particle size of 0.01 .mu.m to 0.1 .mu.m in a weight ratio of carbon black (i)/carbon black (ii) of 95/5 to 5/95, with the non-magnetic particles in the backing layer being present in an amount of 40 to 300 parts by weight per 100 parts by weight of the total binder.

Abstract: A magnetic recording medium comprising a magnetic layer coated on one side of a non-magnetic support and a backing layer coated on the opposite side of the non-magnetic support, wherein the backing layer comprises non-magnetic particles, a binder and silicone having a viscosity of from 1 to 50 CS (centistokes) at 25.degree. C. in an amount of from 0.01 to 3 wt. % based on the non-magnetic particles, wherein the non-magnetic particles contain carbon black in an amount of at least 50 wt. % based on the total amount of the non-magnetic particles, and wherein 25 wt. % or more of the carbon black has an average particle size of from 150 to 1,000 m.mu..

Abstract: A magnetic recording medium is described, comprising a non-magnetic support having a magnetic layer and a backing layer which is provided on the surface of the support opposite to the magnetic layer, the backing layer containing (a) non-magnetic particles comprising carbon black having an average particle diameter of 0.1 to 1.0 .mu.m, (b) a binder comprising (i) a resin having 150 kg/cm.sup.2 or less of 100% modulus in an amount of at least 50 wt % based on the total amount of binder, and (ii) a diphenyl methane diisocyanate type hardening agent, with the amount of non-magnetic particles to total contained in the backing layer being 40 to 300 parts by weight of non-magnetic particles per 100 parts by weight of binder.

Abstract: A magnetic recording medium comprising a non-magnetic support having provided thereon a magnetic layer on one side and a backing layer on the other side, wherein the backing layer contains (1) non-magnetic powders containing carbon black having an average particle diameter of from 0.1 to 1 .mu.m; (2) two or more binders wherein (a) at least one of the binders is a resin having a 100% modulus of from 15 to 150 kg/cm.sup.2 in an amount of from 50 to 95 wt % based on the total amount of the binders in the backing layer, and (b) the rest binder(s) is/are a resin other than the resin having a 100% modulus of from 15 to 150 kg/cm.sup.2, and the weight ratio of all the non-magnetic powders to all the binders in the backing layer is from 300:100 to 40:100; and (3) a polyisocyanate in an amount of from 15 to 40 wt % based on the total amount of the binders in the backing layer.

Abstract: A magnetic recording material, which comprises a non-magnetic support having provided on one side thereof a magnetic layer and on the other side thereof a backing layer is disclosed. The binder of the backing layer is comprised of a combination of a cellulose resin, a vinylidene chloride resin, a polyurethane resin and a polyisocyanate. Use of the backing layer increases the durability of the tape and aids in preventing drop out.