Abstract: An improved flexible magnetic recording medium of the flexible disk type characterized by the use of effective quantities of magnetite to enhance the recording mediums, physical properties, conductivity and opacity. Superior magnetic recording performance is exhibited by such disks.

Abstract: A novel tape testing apparatus of the type which senses errors, stops the tape, and causes the error to be moved to an error-correction or an error-inspection station. The apparatus of the invention is characterized by means to rapidly try to remove the error by additional passes through an error removal station and then, if necessary bring the error-bearing portion of the tape precisely under an inspection station by a precise distance-metering process.

Abstract: Apparatus for cleaning magnetic tape and like webs, comprising a series of sharp scraping edges for cleaning said web, said edges forming the periphery of a series of air ports through which a vacuum is drawn laterally across the bottom of the web. Thus the apparatus can be utilized to perform a novel cleaning process wherein the cleaning edges are constantly washed with air. Air-distributing means is provided whereby there is no situs on the tape being cleaned on which loose debris can be immobilized in a zone of stagnant air during its entire passage through the apparatus.

Abstract: Absorptive shields for transmission lines, especially those tending to radiate electromagnetic wave lengths within a frequency range of from about 10.sup.6 to about 10.sup.10 hertz, especially 10.sup.7 to 10.sup.10 hertz. The shields are flexible materials filled with ferromagnetic, or ferrimagnetic, powders of selected particle size and distribution.

Abstract: Nickel powders having an improved chemical stability are formed by reaction with an electroconductive coating such as a carbide, a silicide, or the like and, also, a reaction with sulfur.

Abstract: A novel silver powder composition characterized by a very low fusion, or film-forming temperature, probably assignable to the relatively small amount of oxides or other undesirable occlusions within coatings formed of the powder. The invention also relates to a new process for forming such a powder; the process is believed to involve the formation of a fatty-acid silver reaction product of the surface of the silver powder before it is subjected to fusion into a metallic coating. During fusion the decomposing reactant seems to act as a flux aiding the formation of a metal film of superior appearance and strength.

Abstract: A novel process for fastening ceramic material such as alumina or the like to metallic material such as an electrical conductor. The process is characterized by the fact that a solder wettable, oxidation-resistant barrier is used, on metal particles printed onto the ceramic. In some advantageous processes, the carbide layer allows metallizing processes to be carried out in non-hydrogen atmospheres. The process requires no expensive noble metal; and it utilizes a barrier material which is sufficiently stable to tolerate conductive film formation at high temperatures. Nickel-carbide coated nickel is a particularly favorable material for use in the invention because it is conductive, in the ohmic sense, and is readily wetted by common solders.Also disclosed are novel articles and compositions useful in practice of the process of the invention, and novel articles produced by the process of the invention.

Abstract: A high-precision, metal-faced, calender roll which can be readily reconditioned by thermal means. The calender roll has a surface which is advantageously formed of that class of nickel-titanium alloys having thermally-responsive shape memory properties. The calender roll is particularly useful in avoiding time consuming repair and undesirably prolonged runs in making high quality magnetic tape.

Abstract: Method for cleaning generally cylindrical articles of irregular configuration and, particularly, for cleaning straps of the type used to hold magnetic tape and supplied by manufacturers for use with magnetic tapes. The method is performed by an apparatus which comprises exterior and interior nozzles resiliently mounted along the inside and outside of the cylinder, or ring, and form means to blow and suck dirt from the article being cleaned.

Abstract: A novel silver powder paint composition characterized by a very low fusion, or film-forming temperature, probably assignable to the relatively small amount of oxides or other undesirable occlusions within coatings formed of the powder. The invention also relates to a new process for forming such a powder; the process is believed to involve the formation of a fatty-acid silver reaction product of the surface of the silver powder before it is subjected to fusion into a metallic coating. During fusion the decomposing reactant seems to act as a flux aiding the formation of a metal film of superior appearance and strength.

Abstract: Polymodal magnetic information-recording articles formed with at least two different populations of magnetic powders, whereby at least one of the powders, being of lower intrinsic coercivity and forming means to accept a noise interference pattern, accepts a pattern which serves as a means to verify the authenticity of, or means to detect previous tampering with, the magnetic recording device. More generally, the disclosure relates to polymodal recording media characterized by incorporation of a plurality of independently-erasable ferromagnetic powder populations and processes for making and using said media. Particular advantage is disclosed for such media having a relatively small ratio of coercivity between easier and harder axis and for material wherein shape anisotropy is absent from adjacent modes in a polymodal system.

Abstract: An improved, conventionally-spoolable, magnetic tape which can be unspooled and read after exposure to very high temperatures. The improvement is largely in a thermally resistant, non-adhering, anti-static backing system, used in conjunction with magnetic face coatings.

Abstract: An improved magnetic recording member of the disc type, the article of the invention is polymodal wherein one mode is formed of a first population of magnetic particles which have a coercivity differing by at least 200 oersteds from the coercivity of particles in another mode. These latter particles are, preferably, metallic magnetic particles oriented in a vertical direction and are in a thin layer over said first population of magnetic particles. This combination overcomes existing limitations on (a) disc products, and (b) the preferred metallic particles heretofore known.

Abstract: Novel powders, and resinous compositions bearing said powders, characterized by excellent chemical stability, electrical conductivity, and energy-absorbing characteristics. These three characteristics can be utilized, alone or combination, in forming many novel articles including microwave shielding apparatus, magnetic recording media, explosives, and the like articles. The more advantageous powders are characterized by a very thin coating of an electrically conductive metal carbide, metal silicide, or metal boride upon the surface thereof, and a metal core.

Abstract: An improved, conventionally-spoolable, magnetic tape which can be unspooled and read after exposure to very high temperatures. The improvement is largely in a thermally resistant, non-adhering, anti-static backing system, used in conjunction with magnetic face coatings.

Abstract: A novel silver powder composition characterized by a very low fusion, or film-forming temperature, probably assignable to the relatively small amount of oxides or other undesirable occlusions within coatings formed of the powder. The invention also relates to a new process for forming such a powder; the process is believed to involve the formation of fatty-acid silver reaction product of the surface of the silver powder before it is subjected to fusion into a metallic coating. During fusion the decomposing reactant seems to act as a flux aiding the formation of a metal film of superior appearance and strength.

Abstract: Improved processes and products based on the discovery that metal atoms in complex relationship with complexing agents can be used to moderate the formation of organic salt seed crystals which promote an exceptionally well-ordered acicular growth of organometallic salts such as oxalates of the metal. Some acicular, i.e. needle-like, products have particular utility for being reduced to ferromagnetic metal particles which retain a surprisingly large degree of acicularity and possess extraordinarily favorable properties for use in magnetic recording applications.

Abstract: An improved capacitor, especially of the tantalum capacitor type, wherein a very small particle silver metal powder is impregnated into a porous metal anode member, say of tantalum. The resulting capacitor has a much reduced resistance in the non-dielectric components of the capacitor without any substantial decrease in the desirably-high reistance across the dielectric component of the capacitor. The process of forming such a capacitor is relatively inexpensive and allows one to avoid a number of manufacturing steps and reduce the manufacturing cost of the improved capacitor even though it contains a relatively large amount of silver metal.

Abstract: Novel materials formed from powders of high porosity, usually characterized by high surface area and always with a very low bulk density, are disclosed. Metal-bearing powders of this type are found to be particularly useful as catalysts and in magnetic applications. Some such powders find use in reinforcement of resins. Also disclosed are novel procedures suitable for making such powders and novel processes and novel compositions in which these powders can be advantageously utilized.

Abstract: Playback method and apparatus compensate exactly for both tracking and speed errors due to any eccentricity in the information track on a rotating recording member during playback by moving the read head in a circular path having the same radius, angular velocity and phase as the circle of eccentricity of the track.