Abstract: A new micro-porous membrane having a layer of minimum pores inside is disclosed. This membrane can be produced by a kind of dry-wet method in which a gas is in contact with the surface of the spread solution before it is immersed in a solidifying bath to form a coacervation phase only in the surface layer of the spread solution. It is quite important to control the amount of non-solvent for a utilized polymer contained in the gas as well as a blowing rate of the gas toward the above mentioned surface. The micro-porous membrane of the present invention not only has an improved filtration flow rate and life as a filter, but also the risk of being damaged by scratches is minimized.

Abstract: A plate-type filter cartridge includes a plurality of stacked filtration units; each filtration unit having inner and outer rims, two filtration membranes bonded to opposite sides of the two rims, and a pair of netty members formed of fibrous material contacting a porous support and membranes. The support supports the membrane and is disposed between the membranes; the support being defined by a plurality of spokes and an outer rim.

Abstract: A filter cartridge for removing particles of the order of submicrons from a solution, comprising at least two filtering films laid in parallel with the inner peripheral portions bonded fixedly to an inner rim of the core and with the outer peripheral portions joined together, thus defining a path of a solution to be filtered, and providing a relatively large effective filtering area.

Abstract: A fine porous membrane having a pore size distribution in the thickness direction and having a layer having a minimum pore size in the interior thereof, wherein the ratio of maximum pore size to the average pore size, each as determined according to ASTM-316-80, is not more than 1.8. The fine porous membrane is produced by a process comprising casting a film-forming solution, comprising a polymer in a solvent having incorporated therein a swelling agent and a non-solvent, on a casting carrier while being in a solution state, directing air having a temperature of from 15.degree. to 60.degree. C. and a relative humidity of from 10 to 80% onto the surface of the cast film at a velocity of from 0.

Abstract: A recording medium comprising a substrate and a recording layer arranged on the substrate, said recording layer being removable by irradiation of radiation having high energy density thereto through evaporation or fusion in the area having received said irradiation, which is characterized in that said recording layer comprises indium and at least one metal compound selected from the group consisting of a metal sulfide, a metal fluoride and a metal oxide and contains at least one metal showing a surface tension of not less than 600 dyne/cm within temperatures of the melting point thereof to a temperature higher than the melting point by 300.degree. C.

Abstract: An optical information recording medium is described, comprising two disc substrates, which are adhered directly or through a convex portion formed on at least one of the substrates or a spacer provided between the substrates by an adhesive layer, and a recording layer which is capable of recording and/or reading information by laser beam and which is provided on a surface of at least one of the substrates facing the other substrate, wherein the adhesive layer satisfies formulae (1), (2) and (3)d/G.gtoreq.0.05 (1)5.times.10.sup.2 .gtoreq.G.gtoreq.5 (2)200.gtoreq.d.gtoreq.20 (3)wherein G is the coefficient of shearing elasticity (kg/cm.sup.2) of the adhesive layer at 23.degree. C., and d is the thickness (.mu.m) of the adhesive layer.

Abstract: There is provided a magnetic recording material produced by coating on a support a magnetic coating composition which contains as main components a magnetic powder and a binder, the binder comprising an urethane acrylate synthesized using a polyester polyol having a particular structure, and by irradiating the resulting magnetic coat with electron beams to harden it. The polyester polyol contains polyhydric alcohol component, 50 mole % or more of which is a dihydric alcohol selected from the class (A) described below, and/or polybasic acid component, 50 mole % or more of which is a dibasic acid selected from the class (B) described below. The urethane acrylate is synthesized under such a condition that it may have two or more of (meth)acryloyl groups per molecule. Thus, improvements in electromagnetic properties and in durability are attained.

Abstract: An information recording medium comprising in order, a glass substrate; a layer for preventing diffusion of alkali metal ions and alkaline earth metal ions from the substrate; a thermal barrier layer, and an information recording layer for writing and/or reading information by means of laser beam.

Abstract: A magnetic recording medium comprised of a support having a magnetic layer coated thereon is disclosed. The magnetic layer is comprised of a binder composition having a ferromagnetic powder dispersed therein. The binder composition is cured by an electron beam. The composition is comprised of 50 to 400 parts by weight of a compound having 2 or more acryloyl groups or methacryloyl groups in the molecule and 100 parts by weight of a mixture of 20 to 80 parts by weight of a thermoplastic resin having a thermal deformation temperature of 70.degree. C. or more and 20 to 80 parts by weight of a rubber type resin. The material has excellent electromagnetic properties after repeated use. Further, the medium has high physical strength and excellent wear resistance.

Abstract: In an information recording medium having an air-sandwich structure comprising two disc-shaped substrates opposed to each other at a given space by interposing therebetween a ring-shaped inner spacer and a ring-shaped outer spacer and a recording layer for writing and/or reading information with laser beam which is provided on the inner surface of at least one substrate, the improvement in which at least one spacer is an adhesive-retainable spacer comprising a ring portion of protecting circumferences of the substrates and a protruding ring portion of arranging the two substrates apart, the latter ring portion protruding from a side of the protective ring portion and comprising a front portion for defining the space between the substrates and a stem portion being thinner than the front portion for retaining an adhesive, whereby an excessive adhesive or a volatile material of the adhesive is discharged through a space between the substrate and the stem portion of the protruding ring portion.

Abstract: A recording medium having an air-sandwich structure comprising two disc-shaped substrates opposed to each other at a given distance by interposing therebetween a ring-shaped inner spacer and a ring-shaped outer spacer and a recording layer for writing and/or reading information with laser beam which is provided on the inner surface of at least one substrate,characterized in that the distance between said two substrates satisfies the following expression (I): ##EQU1## wherein h is the distance in mm between two substrates, E.sub.1 and E.sub.2 are each a Young's modulus (in kg/mm.sup.2) of each substrate, l is the distance (in mm) between the inner spacer and the outer spacer, and t.sub.1 and t.sub.2 are each the thickness (in mm) of each substrate.

Abstract: A magnetic recording medium comprising a support having coated thereon a magnetic layer is disclosed. The magnetic layer is comprised of a binder composition having ferromagnetic particles dispersed therein. The binder composition is cured by an electron beam and comprises a copolymer, a urethane resin and a compound having two or more acryloyl groups or methacryloyl groups. The copolymer may be a vinyl chloride-vinyl acetate-vinyl alcohol copolymer having a vinyl alcohol content of 1 to 15 wt % or a vinyl chloride-vinyl acetate-maleic acid copolymer having a maleic acid content of 1 to 10 wt %. The recording medium has excellent electromagnetic properties and the magnetic layer has excellent dynamic properties.

Abstract: A process for producing a magnetic recording material comprising a support having a thin metal film layer provided thereon is described, the process comprising the steps of (1) coating a thin magnetic metal film having a water contact angle of at least 25.degree. with a polymer solution to form a thin polymer layer, drying the thin polymer layer, and providing a lubricant on the thin polymer layer, or (2) coating the thin magnetic metal film with a lubricant-containing polymer solution to form a lubricant-containing polymer layer, and drying the lubricant-containing polymer layer.

Abstract: A magnetic recording medium having a thin magnetic film on a non-magnetic support base is disclosed. A layer of a compound which contains at least two isocyanate groups is formed in connection with the medium, and may be formed on either the surface of the metal film or the surface of the base opposite the metal film, or both. The resulting medium has excellent running properties, wear resistance and electro-to-magnetic conversion characteristics which are maintained after repeated use. The medium is formed by providing a non-magnetic support base surface and coating that surface with a thin magnetic metal film by use of a process such as vapor deposition. A solution of a compound containing at least two isocyanate groups is then applied to the medium within a solvent after which a heat treatment is carried out, thus forming the layer of compound containing the isocyanate groups.

Abstract: A magnetic recording medium and a process for producing a magnetic recording medium are disclosed, the process comprising the steps of applying onto a non-magnetic base a composition comprising (1) a compound having an unsaturated bond polymerizable by electron beams, (2) at least one polymer, (3) ferromagnetic particles, and (4) an organic solvent, and then polymerizing and curing the resulting magnetic layer by irradiation with electron beams, said polymer being such that at least 10% thereof is adsorbed on the ferromagnetic particles in a mixture of 10 parts by weight of a 1 wt % solution of the polymer and 1 part by weight of the ferromagnetic particles.

Abstract: A process for producing a cellulose ester support is described which comprises producing said support from an organic solvent solution of a cellulose ester containing 30 ppm or less alkaline earth metal.

Abstract: A magnetic recording medium having a thin magnetic metal film on a non-magnetic base is disclosed. A surface layer is formed on either the thin magnetic metal film or the other side of the base or both by irradiating a coating of a polymer having an unsaturated bond polymerizable by radiation. A process for producing such magnetic recording medium is also disclosed.

Abstract: A magnetic recording medium and a process for producing a magnetic recording medium are disclosed, the process comprising the steps of applying to a non-magnetic base a composition comprising (1) a compound having an unsaturated bond polymerizable by electron beams, (2) a compound having one or more carbon-carbon unsaturated bonds, (3) ferromagnetic particles and (4) an organic solvent, and polymerizing and curing the applied coating by irradiation with electron beams, said compound having one or more unsaturated bonds is such that at least 10 wt % thereof is adsorbed onto the ferromagnetic particles in a mixture of 10 parts by weight of a 1 wt % solution of the compound and 1 part by weight of the ferromagnetic particles.

Abstract: A magnetic recording medium and a process for producing a magnetic recording medium are disclosed, the process comprising the steps of applying onto a non-magnetic base a magnetic coating composition comprising (1) a compound having a carbon-carbon unsaturated bond polymerizable by electron beams, (2) a coupling agent having a carbon-carbon unsaturated bond, (3) ferromagnetic particles, and (4) an organic solvent, and curing the applied magnetic coating composition by irradiation with electron beams.

Abstract: A magnetic recording medium having a thin magnetic metal film formed on a non-magnetic base is disclosed. A thin film of a copolymer having vinylidene chloride and acrylonitrile as repeating units is formed on either the thin magnetic metal film or the surface of the base opposite the thin magnetic metal film or both. The resulting magnetic recording medium has improved running properties, wear resistance and electro-to-magnetic conversion characteristics.