Abstract: An abrasive tape comprises a flexible substrate and an abrasive layer which is overlaid on the flexible substrate and which contains abrasive grains and a binder. The abrasive grains comprise first abrasive grains, which have a mean grain diameter within the range of 0.07 .mu.m to 0.40 .mu.m and a Mohs hardness within the range of 5 to 7, and second abrasive grains, which have a mean grain diameter within the range of 0.20 .mu.m to 0.60 .mu.m and a Mohs hardness not lower than 8.5.

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 switching device comprising a reed switch of a normal open type turned on and off by a magnetic field, a fixed bias magnet located in an area where the switch operates stably, and a starting magnet located opposite to the fixed bias magnet with the switch interposed between them and capable of applying a magnetic field, reverse to that of the fixed bias magnet, to the switch. When the starting magnet is carried close to the switch, its a magnetic field overcomes that of the fixed bias magnet to control the switching-on and -off of the switch, and when it is carried remote from the swtich, the fixed bias magnet controls the switching-on and -off of the switch.

Abstract: A magnetic recording medium comprising a non-magnetic support having coated thereon a magnetic layer, the magnetic layer containing (i) ferromagnetic alloy particles having an average length in the long axis of 0.25 .mu.m or less and (ii) fatty acid components comprising behenic acid in an amount of 20 to 75 wt%, stearic acid in an amount of 10 to 45 wt% and oleic acid in an amount of 10 to 45 wt% based on the total weight of the three fatty acids.

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 comprising a nonmagnetic support having coated thereon a magnetic recording layer comprising a ferromagnetic particles dispersed in a binder, the binder containing polyisocyanate and the molar ratio of (urethane bond+allophanate bond):(urea bond+biuret bond) being 85:15 to 60:40.

Abstract: A magnetic recording medium comprised of a nonmagnetic support base having a magnetic layer provided thereon is disclosed. The magnetic layer includes ferromagnetic particles dispersed in a binder in combination with carbon black particles. The carbon black particles have an average primary particle size in the range of 30 m.mu. to 50 m.mu.. Further, the carbon black is capable of the adsorption of 120 ml or more of dibutyl phthalate per 100 g of carbon black. By utilizing the particular carbon black of the present invention it is possible to obtain a magnetic recording medium having improved running properties.

Abstract: A magnetic recording medium is disclosed. The medium is comprised of a support base having coated thereon a magnetic layer comprised of ferromagnetic particles dispersed in a binder and further comprised of at least one anhydrosorbitol di- and/or tetra-fatty acid non-hydroxy ester. By including the particularly disclosed fatty acid non-hydroxy ester the running properties of the magnetic recording medium are greatly improved.