Abstract: A magnetic recording tape or disc which has excellent total characteristics of an adhesive strength, a repeat running durability, an electromagnetic characteristic, a gloss degree of the surface and a curling is provided. A binder of a magnetic layer comprises 40 to 70 wt. % of a urethane resin, 15 to 40 wt. % of an epoxy resin and 10 to 40 wt. % of a phenoxy resin.

Abstract: In a magnetic recording medium having a substrate coated with a magnetic layer comprising a magnetic powder and a binder, an improvement characterized in that said binder in said magnetic layer essentially consisting of 20 to 60 wt. % of a polyurethane, 15 to 45 wt. % of a polyester resin and 20 to 50 wt. % of a vinyl chloride-vinyl acetate copolymer-impregnated nitrocellulose.

Abstract: A magnetic recording medium comprises a substrate coated with a magnetic powder composition comprising a magnetic powder and an organic binder having a main component of vinyl chloride-vinyl alcohol copolymer.

Abstract: A magnetic recording medium comprises a magnetic layer formed by coating a magnetic powder composition obtained by mixing an abrasive powder having an average diameter of 0.8 .mu.m or more and an abrasive powder having an average diameter of 0.4 .mu.m or less and a magnetic powder in a binder, on a base film.

Abstract: A magnetic tape cassette including an intermediate frame which has flat upper and under surfaces in parallel and provides a sufficient space therein to hold a length of magnetic tape, and substantially flat top and bottom plates fastened, respectively, to the flat upper and under surfaces of the intermediate frame, characterized in that said intermediate frame is made of a composite resin material which comprises an unsaturated polyester resin and a thermoplastic polymer containing from 50 to 75% by weight of calcium carbonate and glass fiber on the basis of the total resin weight, the intermediate frame having a linear expansion coefficient in the range from 1.times.10.sup.-5 to 3.times.10.sup.-5 /.degree.C., said calcium carbonate and said glass fiber being used in a ratio by weight of from 60:10 to 40:30.

Abstract: A recess for positioning a magnetic tape cassette inserted in a deck is formed near a corner of a guard panel, a small projection is formed on at least one of an inner surface of the guard panel or a front surface of a casing near the side edge of the magnetic tape. A tape guide shaft is fixed inside of a casing so as to place the surface of the tape guide slightly behind the level of the front surface of the casing.

Abstract: A thin metallic layer type magnetic recording medium having thin metallic layers in a structure comprises a layer in which a tilt angle of a metallic particle direction to the normal line to said substrate gradually increases depending upon an increase of a distance from said substrate; and a layer in which a tilt angle of a metallic particle direction to the normal line to said substrate gradually decreases depending upon an increase of a distance from said substrate.

Abstract: A ribbed ring for winding a magnetic tape cut in narrow width is disclosed which has an annular outer peripheral part and a groove for reinforcing the ring against deformation and a rib for fitting to a groove of an adjacent ring and an annular inner peripheral part having one or more slits for fitting to a spline shaft.

Abstract: A tape cover made of resin comprises a single-piece L-shaped body of an upper plate and a front plate and an erroneous insertion detecting notch formed in the joint of the plates, wherein a gate is formed in the notch and the thickness of the wall of a portion adjacent the notch in the upper plate is smaller than the distance from the edge of the upper plate to the most remote part of the diameter of the gate.

Abstract: A tape cover formed by molding an L-shaped body of an upper plate and a front plate in one piece in which an erroneous insertion detecting notch is formed in the joint portion of both the plates comprises an injecting port as a gate positioned on a side surface of said upper plate in said notch, and the thickness of the wall of said upper plate just below said injecting port is larger than that of the other part of the wall of said upper plate near said injecting port wall.

Abstract: A magnetic tape cassette has a tape pad for pushing the magnetic tape in the path of the magnetic tape. The tape pad comprises one piece of a tape contacting part and a spring member for supporting the tape contacting part which is made of a carbon-containing polymer having elasticity.

Abstract: A magnetic recording medium having a substrate coated with a magnetic layer comprises a binder, a magnetic powder and a metal phosphide at a ratio of 0.2 to 5.0 wt. % based on said magnetic powder.

Abstract: A magnetic tape cassette comprises a pad support membrane made of a metal alloy such as bronze and nickel silver. The pad support membrane is coated with a synthetic resin layer containing a rust inhibitor.

Abstract: A fitting piece is adapted to fit in a recess for receiving an actuation pin of a recorder. The fitting piece comprises a middle portion; a pair of legs vertically extending the ends of the middle portion; and a cooperative lug formed on the leg. The fitting piece can be fitted into the recess in two different positions either permitting recording or preventing cancellation of the recorded sound.

Abstract: A cleaning tape for a magnetic recording apparatus comprises a substrate coated with a cleaning layer comprising magnetic iron oxide power as a main component and a non-magnetic abrasive power having Moh's scale of hardness of at least 6 and a binder wherein said cleaning layer has a surface roughness of 0.5 to 5 .mu.m and a ratio of said abrasive powder to iron oxide powder of 0.3 to 40 wt. % and especially 3 to 40 wt. % in the case of said surface roughness of 0.5 to 1 .mu.m; 0.5 to 20 wt. % in the case of said surface roughness of 1 to 2 .mu.m; 0.3 to 10 wt. % in the case of said surface roughness of 2 to 5 .mu.m.

Abstract: A case for holding a magnetic tape cassette comprises a case body and a cover pivotally joined together by a pair of pivots fitted in corresponding pivot-receiving holes, with arcuate protuberances formed respectively around the pivots and pivot holes in such a manner that, when the pivots have been fitted in the holes, the both protuberances coact to keep the opposing side walls of the case body and the cover apart from each other, the protuberances themselves being arranged so as not to overlap each other. The pivots protrude inwardly from the side walls of the case body, the pivot holes are formed in the side walls of the cover, and the arcuate protuberances are formed, one for each, on the inner faces of the side walls of the case body and on the outer faces of the side walls of the cover. The protuberances of the case body are formed to extend semicircularly through an angle of 180 degrees around the pivots, and the protuberances of the cover extend through an angle of 90 degrees around the pivot holes.

Abstract: A lubricant sheet for a magnetic tape cassette characterized in that at least one side of a base incorporating an antistatic agent is provided with a release type silicone coating. This lubricant sheet combines the transparency derived from the use of the clear base and coating materials with the low friction characteristic and the antistatic property to suit the application as such for transparent tape cassette cases.

Abstract: A tapping boss formed in one piece with the upper half casing for joining the lower half casing of a magnetic tape cassette comprises a stem having a cross sectional area slightly larger than the diameter of a tapping screw to receive the screw and a plurality of ribs which project radially from the cylindrical surface of said stem and whose top portions provide contact shoulders for the boss supporter of a lower half casing.

Abstract: A magnetic recording medium having multi-layer structure of two or more thin metallic layers on a substrate. The orientations of metallic particles are different for each of said thin metallic layers.

Abstract: A magnetic tape cassette having one or more guide pole which is forcibly inserted at each end into each axial hole formed in a casing comprises an air releasing portion for releasing air during the forcible insertion of said guide pole in said axial hole.