Abstract: A belt-like material stably transferring apparatus an absorbing and feeding apparatus for continuously absorbing and feeding the belt-like material by use of a difference in air pressure. The absorbing and feeding apparatus comprises a reserving chamber for absorbing and feeding the belt-like material to be reserved therein, and a pressure detecting chamber connected to the reserving chamber through a slit. The reserving chamber has an opening portion for feeding the belt-like material, and blowers and are connected at a position, which is opposite to the opening portion. The pressure of the pressure detecting chamber is changed in accordance with the change of the pressure in the reserving chamber connected to the pressure detecting chamber through the slit. The pressure of the reserving chamber is changed in accordance with the amount of absorbing and feeding the belt-like material absorbed and fed to the reserving chamber.

Abstract: An optical recording disk of air sandwich type includes a transparent disk carrying a transferring layer and a protection disk which are symmetrically disposed with respect to a central plane between the transparent and protection disks, the protection disk being the same as the transparent disk in material and shape and having a dummy layer which is the same as the transferring layer in material and shape.

Abstract: An optical disc is disclosed in which a pair of circular disc substrates are arranged in confronted relation with each other with their signal recording layers being directed inwardly and are bonded to each other through spacers at inner and outer peripheral portions. A vent hole is formed in a main surface of one of the disc substrates. A disc label is bonded on the disc substrate so as to cover the vent hole.

Abstract: An optical disk includes two disk substrates bound together with a spacer in between and at least one of the substrates has a recording layer facing the inside. Before using the adhesive, the portion of the recording layer in the bonding area is removed so that the adhesive is applied directly between the spacer and a transfer layer which has been formed on top of each substrate. The bonding inside the disk is much stronger and peeling of the disk is prevented.

Abstract: An optical information recording disk is formed by a pair of disk-like substrates with an inner and an outer annular spacer member disposed therebetween. The inner spacer member supports an inner circumferential portion of each of the disk-like substrates, and the outer spacer member supports an outer circumferential portion of each of the disk-like substrates. The spacer members and substrates thus define an interior space. The spacer members and substrates are fixed together by means of a thermosetting adhesive agent. A notched portion is formed in at least one of the space members so as to communicate the interior of the disk with the ambient atmosphere. Thus, during heating of the disk for purposes of joining the substrates and spacers by hardening the adhesive agent, air in the interior space in the disk can escape through the notched portion. After heating, the notched portion is filled with a sealing member such as a solid member or another adhesive agent.

Abstract: A disk-shaped information recording medium is provided in such a manner that at least one information bearing layer formed on a side of a pair of disk-shaped substrates, which substrates are arranged so that the information bearing layers face each other with a hollow space between them by means of inner and outer spacers being concentrically interposed between the two substrates. A polyurethane adhesive layer is formed between the substrate and the spacer to combine said pair of substrates together via the inner and outer spacers.

Abstract: A molding composition is obtained by blending flaky graphite with a resin component comprising a mixture of a thermoplastic resin having a glass transition temperature higher than room temperature and another thermoplastic resin having a glass transition temperature lower than room temperature. The composition is kneaded and rolled into a sheet to orient the graphite flakes parallel to the surface of the sheet. The rolled sheet is then molded into an article, for example, speaker diaphragm, arm pipe and head shell, which may be optionally be carbonized or graphitized. The resulting article exhibits improved physical properties, especially high specific modulus of elasticity comparable to aluminum and beryllium as well as good internal loss comparable to paper.

Abstract: Elements for a tone-arm system such as arm pipes, head shells, cartridge bodies, and arm bases are fabricated from a kneaded mixture comprising polypropylene and flaky graphite powder. The mixture may further include polymethyl methacrylate and/or rubber-like material. Graphite flakes are preferably oriented parallel to the surface of the element. The elements show improved temperature resistance.

Abstract: Vibratory elements for use in audio equipment are fabricated from a kneaded mixture comprising polypropylene and flaky graphite powder. The kneaded mixture is rolled into a sheet in which graphite flakes are oriented parallel to the surface, and the sheet is then formed into a desired shape, for example, a dome- or cone-shaped diaphragm and a cantilever, as by vacuum forming, air-pressure forming or press molding. The mixture may further include polymethyl methacrylate and/or rubber-like material. The elements are characterized by improved temperature resistance.

Abstract: A diaphragm for acoustic instruments such as speakers is produced by blending and kneading a thermoplastic resin such as polyvinyl chloride resin with graphite powder, rolling the blend into a sheet until graphite particles are oriented, and forming the sheet into a desired diaphragm shape. The diaphragm of the composite material containing graphite particles oriented shows an improved combination of density, elasticity and internal loss.

Abstract: Vibratory elements for use in audio equipment are fabricated from a kneaded mixture comprising post-chlorinated polyvinyl chloride and flaky graphite powder. The kneaded mixture is rolled into a sheet in which graphite flakes are oriented parallel to the surface and the sheet is then formed into a desird shape, for example, a dome- or cone-shaped diaphragm and a cantilever, as by vacuum forming, air-pressure forming or press molding. The mixture may further include polymethyl methacrylate and/or rubber-like material. The elements are characterized by improved temperature resistance.

Abstract: A molding composition comprising a thermoplastic resin in admixture with flaky graphite and carbon black is molded into an acoustic article which shows a high specific modulus of elasticity due to graphite and an increased internal loss due to carbon black. Preferred molding compositions contain 10-90 wt % of polyvinyl chloride or a vinyl chloride-vinyl acetate copolymer and 90-10 wt % of graphite flakes plus carbon black submicron particles. Carbon black is present in an amount of 0.1-2 parts per part of flaky graphite. Speaker diaphragms, arm pipes and head shells are fabricated from the molding composition. The composition is kneaded and rolled to orient the graphite flakes, and subsequently molded into an article, which is then optionally carbonized or graphitized.

Abstract: A head shell for a record player tonearm comprises a composite material essentially consisting of a thermoplastic resin and graphite powder. The composite material is prepared by kneading the components, rolled to impart a degree of orientation to the graphite powder particles, which are in the form of flaky graphite and then molded into a shell, along the surface of which the graphite particles are oriented. Head shells wherein the composite material is oxidized at the surface and head shells wherein the composite material is carbonized or graphitized are also included. A light weight, rigid head shell having a high specific modulus of elasticity is obtained through a simple procedure at low cost.

Abstract: An arm pipe for a record player tonearm comprises a composite material essentially consisting of a thermoplastic resin and graphite powder. The composite material is prepared by kneading the components, rolled to impart a degree of orientation to the graphite powder particles, which are in the form of flaky graphite and then molded into a pipe, along the surface of which the graphite particles are oriented. Arm pipes wherein the composite material is oxidized at the surface of the pipe and arm pipes wherein the composite material is carbonized or graphitized are also included. A light weight, rigid arm pipe having a high specific modulus of elasticity is obtained through a simple procedure at low cost.

Abstract: A method of producing a diaphragm of an acoustic instrument having the steps of blending powders of carbon such as graphite, carbon black or the like and a thermoplastic or a thermosetting resin, shaping the resultant blend into a desired form and then carbonizing the shaped blend. As a result, it has become possible to produce a diaphragm of an acoustic instrument, having a light weight, high rigidity and a large ratio of Young's modulus to density.

Abstract: A method of surface hardening a substrate made of an inorganic material by diffusing a different inorganic material into the substrate is disclosed wherein the diffusion is effected in an alkali metal gas atmosphere. The substrate may be made of titanium, zirconium, iron, yttrium, tungsten, tantalum or a material containing one of those elements as a principle component. The diffusion material may be boron, silicon or a material containing one of those elements. The alkali metal gas atmosphere is produced by heating metallic sodium, potassium, lithium or a combination thereof. The surface hardened substrate produced according to the method exhibits an increased Young's modulus of elasticity, hardness and mechanical strength and is particularly suitable in the manufacture of electro-acoustic diaphragms as well as other light weight, high mechanical strength articles.