Abstract: When a thin film is formed on a flexible and filmy substrate by a vapor phase method, the substrate is prevented from warping to be caused by the internal stress remaining in the thin film. When the thin film is formed by the vapor phase method, the substrate is previously curved so that the stress acts in the direction canceling the internal stress remaining in the thin film to be formed prior to the filming. Accordingly, the stress of the curved substrate cancels out the stress remaining in the thin film formed on the substrate. The substrate having a thin film formed thereon is not warped, the stress in the interface between the thin film formed and the substrate is removed, and the thin film has no cracks to be caused by the stress.

Abstract: Methods and apparatus are disclosed for producing gypsum board having at least one facing sheet, a core of cementitious material such as low density gypsum, and an intermediate layer of bond promoting material, such as higher density gypsum located therebetween. The apparatus includes a forming table having a transverse gap. The facing sheet travels along the forming table over the gap. A spreader roller has an outer surface extending partially into the gap to depress the facing sheet. The bond promoting material is deposited on the facing sheet upstream of the spreader roller and the spreader roller outer surface rotates in the same direction as the facing sheet to coat the facing sheet with the bond promoting material. The core layer material is deposited on the facing sheet downstream of the spreader roller on top of the bond promoting coating.

Abstract: The process for producing pressure-sensitive adhesive tapes comprises the steps ofclamping a tube strip of a tube skin filled with a pressure-sensitive adhesive composition into an apparatus comprising a tubular appliance,passing the tube strip through the tubular appliance while opening the tube skin longitudinally to form a tape,separating the tape from the pressure-sensitive adhesive composition in such a way that some of the pressure-sensitive adhesive composition remains as a film on the tape,causing the separated pressure-sensitive adhesive composition to exit the apparatus by way of a discharge aperture, andwinding up the tape separated from the pressure-sensitive adhesive composition, with the pressure-sensitive adhesive film that has remained thereon, as a pressure-sensitive adhesive tape.

Abstract: An oriented polyester film coated on at least one surface with a coating that improves its adhesion to gelatin is disclosed. The dry coating contains one or more sulfopolyesters; one or more tetrablock copolymer resins; and one or more non-volatile polyamines. Other ingredients, such as particulate materials and surfactants, may be present in the coating. The coating is preferably applied at the interdraw stage.

Abstract: A reflective polarizer and a dichroic polarizer are combined to provide an improved optical polarizer. The dichroic and reflective polarizers are typically in close proximity to each other, and are preferably bonded together to eliminate the air gap between the polarizers. The combination of the two polarizers provides a high reflectivity of one polarization and high transmission for the perpendicular polarization from the reflective polarizer side of the combined polarizer, and high absorption and transmission for light of orthogonal polarization from the dichroic polarizer side. The combination also reduces iridescence as seen in transmission and when viewed in reflection from the dichroic polarizer side. The increased extinction ratio and low reflectivity of the optical polarizer allows use of a lower extinction ratio dichroic polarizer in applications requiring a given extinction ratio and high transmission.

Abstract: Thin thermoplastic foil is applied with the aid of a wide slit nozzle and an electrostatic discharge electrode to a nonwoven mat of thermoplastic fibers and filaments on a bonding roller and the resulting composite is then subjected to biaxial stretching utilizing at least some of the bonding heat carried by the composite. The composite may then be thermally fixed before being cooled to room temperature.

Abstract: Method and apparatus of coating a plurality of wet layers on an flexible elongated web, which is economical to build and easy to operate at high speeds, and an apparatus which can be used to manufacture multi-layer magnetic recording media of the highest quality. Such apparatus can employ a gravure coater while an extrusion die both smoothes the wet gravure layer to eliminate its pattern and simultaneously extrudes a second dispersion. That smoothing is provided by a face of the upstream lip, which face has a convex shape that allows the wet gravure layer to remain in contact with the upstream lip over a wrap angle .gamma. of at least two degrees, thus ensuring that the tensioned carrier web neither buckles in the cross-web direction nor experiences instabilities such as fluttering. The extruded layer is contacted by a smooth face of the downstream lip, and the coated carrier web exits the smooth face substantially tangentially at a sharp trailing corner.

Abstract: The present invention is concerned with a novel azo compound represented by formula (1), (2) or (3), a water-soluble dye comprising this azo compound, and a polarizing film containing this azo compound. The obtained polarizing film has high hydrothermoresistance and a high polarization degree and is excellent in optical characteristics: ##STR1## wherein each of the groups is defined.

Abstract: A laminated film comprising a base film and a layer which contains an inorganic layered compound and a resin and is formed by gravure coating a coating fluid comprising the inorganic layered compound and the resin under the conditions satisfying the following equation:7<log?2((G/B).times.100).sup.2 .times.(B+G).sup.2 .times.(GM)!<13wherein G is a rotational speed of a gravure roll (m/min.), B is a rotational speed of a backing roll (m/min.) and GM is a mesh number of a gravure roll, which film has good transparency and gas barrier properties.

Abstract: A method and apparatus for extrusion coating both sides of a metal strip. A metal strip, such as aluminum alloy strip, is moved through a pre-conditioner, two extrusion dies, a post-heater and a cooling system. Both sides of the strip are coated with thin coatings of thermoplastic polymers. The coated metal strip is useful for containers, such as cans and can ends, as well as for automobiles, appliances, aerospace, construction and electrical devices.

Abstract: The invention comprises a fixture and method for holding optical waveguid such as fiber optic cable, in a relatively stable fashion for processing. The fixture includes a first frame and a second frame, releasably securable to the first frame to form a unitary structure. Chambers disposed in at least one of the frames are adapted for removably receiving optical fiber cable when the first and second frames are released from one another and for securely retaining with molding material optical fiber cables when the first and second frames form the unitary structure. A process area is defined in the unitary structure such that segments of optical fiber cables secured therein are accessible in the process area for processing. An optional coating fixture is securable to said unitary structure for forming with a molding material a protective coating about the cable segments in the processing area.

Abstract: When a thin film is formed on a flexible and filmy substrate by a vapor phase method, the substrate is prevented from warping to be caused by the internal stress remaining in the thin film. When the thin film is formed by the vapor phase method, the substrate is previously curved so that the stress acts in the direction canceling the internal stress remaining in the thin film to be formed prior to the filming. Accordingly, the stress of the curved substrate cancels out the stress remaining in the thin film formed on the substrate. The substrate having a thin film formed thereon is not warped, the stress in the interface between the thin film formed and the substrate is removed, and the thin film has no cracks to be caused by the stress.

Abstract: A method and apparatus is disclosed for the in-line pre-impregnation of glass or synthetic fibers with a non-aqueous chemical treatment. The apparatus includes a first applicator for applying a curable, non-aqueous chemical treatment agent and a second applicator for applying a curing agent for the chemical treatment agent. The fibers are passed over the first and second applicators which are arranged either in parallel or in series, and are then joined by a gathering device to initiate curing of the chemical treatment agent on the fibers. In an alternative embodiment, the apparatus comprises a spray gun in which a mixture of the non-aqueous chemical treatment agent and curing agent are sprayed onto an applicator roll in contact with the fibers.

Abstract: A porous product, typically a metal foam sheet, is produced as a tailored, engineered product. The porous product can have enhanced strength, as well as more desirable electrical and mechanical properties. The product which first exists typically as a flexible, generally polymeric foam sheet in strip form, which strip is produced in the longitudinal direction, is stretched in a direction other than its direction of production. The porous product can have pores which would be anisotropic in form in usual production, which are stretched to at least substantially isotropic form. The product can even be tailored to have pores which are anisotropic in the direction of the stretch. Thus, an engineered product can be produced which, for example, as an open-cell metal foam prepared from a polymeric foam can have conductivity, both thermal and electrical, as well as strength and ductility, tailored for greater uniformity and performance.

Abstract: A coating system for material webs, specifically of paper or cardboard, includes two mutually parallel rolls directly coordinated with each other, the rolls having a mutually variable spacing such that the rolls can be positioned to create a press gap for coating the web, or so as not to create a press gap. When the rolls are not positioned to form a press gap, the web passes over both roll shells while circumventing the applicators which have already dosed the roll shells with a coating mixture. The web passes over both roll shells for purposes of transferring the coating mixture predosed by the applicators. Solely the web pull in conjunction with the wrap angle of the two roll shells serves the final dosing by scraping off an excess quantity from the roll shells.

Abstract: A method and apparatus for coating a moving paper or cardboard web, in which the moving web is brought to a first backing roll and coating mix is metered onto the web by means of a pre-doctoring blade in the form of a high-velocity laminar flow in front of the pre-doctoring blade. The applied coating mix is smoothed evenly onto the web with the pre-doctoring blade and the coated web is brought to a second backing roll, where the applied coating mix is smoothed using a doctor blade working on the web supported by the second backing roll. The tension of the web is measured upstream from the first backing roll and the rotational speed of the second backing roll is set so that the tension of the web is set at a desired value. The rotational speed of the first backing roll is set so that a speed difference between the first and the second backing roll compensates for elongation of the web caused by wetting between the first and second backing rolls.

Abstract: A method of making a hollow waveguide for transmitting electromagnetic radiation includes: filling voids on the inner surface of an insulator tube with a coating of a void-filling, hydrophylic material having a free pair of electrons and capable of complexing metal ions; applying a solution of a metal salt over the void-filling material to form a metal complex with the void-filling material; reducing the metal complex to a pure metal layer; and depositing a dielectric film on the pure metal layer.

Abstract: A composite membrane including a microporous polymer film having a high air permeability as a support and a non-porous gas or vapor separating coating having a thickness of not more than 15 .mu.m is provided. The separation factor and flux of the membrane are substantially equal to those of the coating. Also provided is a process for the manufacture of a composite membrane including a support and a gas or vapor separating coating by drawing a polymeric film to which the coating material has been applied, and increasing the viscosity of the coating during drawing.

Abstract: An extrusion coating head which is disposed between a drier for performing a non-contact drying operation and a support roll located at the upstream side of and nearest to the drier is designed so that a back edge surface thereof is designed to have an round surface having a radius of curvature R which satisfies the following inequality: 3 mm.ltoreq.R.ltoreq.30 mm, and the entire R-surface portion of the back edge of the coating head is located at a position higher than a tangential line drawn to the front edge surface at a slit-side edge point of the front edge so as to project toward the web side. The running web is coated with the coating liquid by the extrusion-type coating head, and then dried through a non-contact drying process.

Abstract: The invention provides a process for producing a highly absorbent, high strength wiper, which includes the steps of providing a bonded nonwoven web selected from the group consisting of spunbond fiber webs and staple fiber webs, stretching the nonwoven web by applying a stretching tension in at least one direction, aperturing the nonwoven web while maintaining the stretching tension, and relaxing the apertured web, thereby returning the apertured nonwoven web substantially to its pre-stretched dimensions, wherein the process is conducted at a temperature below the softening point of the nonwoven web. The invention also provides a nonwoven wiper produced in accordance with the production process.

Abstract: A method for vapor phase depositing a thin seed layer of, for example, chromium and copper onto the side walls of through holes in thin film substrates of, for example, polyimide is disclosed. This method is useful in fabricating devices such as a thin film semiconductor chip carrier in which a semiconductor chip mounted on one major surface of the chip carrier is electrically connected to a ground plane and/or a power conductor on the other major surface of the chip carrier via one or more metallized through holes.

Abstract: Applications of isotactic polypropylene resin compositions produced from metallocene catalyst wherein the resins yield articles with comparable shear modulus and heat distortion temperature values to those of conventional polypropylene, but in which the fabrication of the article is achieved at temperatures much lower than possible for conventional polypropylene.

Abstract: A waterproof zip closure is formed by extruding a first thermoplastic material onto its teeth, and applying a transverse force while the first thermoplastic material cures. The transverse force is sufficient to move the teeth in the separating direction, but is less than that which can cause separation. After curing of the thermoplastic material, the tapes and teeth of the zip closure are coated with a second thermoplastic sealing material, while the transverse force is maintained. When the transverse force is removed the sealing material is forced together to provide a waterproof seal. The second thermoplastic sealing material on the tapes further improves the waterproof nature of the zip closure.

Abstract: A method for extrusion coating both sides of a metal strip. A metal strip, such as aluminum alloy strip, is moved through a pre-conditioner, two extrusion dies, a post heater and a cooling system. Both sides of the strip are coated with thin coatings of polyester material. The coated metal strip is useful for containers, such as cans and can ends, as well as for automobiles, appliances, aerospace, construction and electrical devices.

Abstract: A wetting unit provides a contact agent between the coating roll and the film surface before coating by a thermal source.

Abstract: A method of producing a magnetic recording medium comprises the steps of heating in vacuum a magnetic recording medium produced by forming a ferromagnetic metal-film-type recording medium onto a non-magnetic substrate and of forming, immediately after heating, a protective layer on the magnetic recording medium by a plasma CVD method. A production apparatus for carrying out this method comprises a feeding apparatus for feeding a magnetic recording medium with a ferromagnetic thin film formed on a non-magnetic substrate, a plasma CVD apparatus, disposed in the path of this feeding apparatus, for forming a protective layer, and a heating apparatus disposed just before this plasma CVD apparatus in the feeding path.

Abstract: A method for manufacturing a polyester film is disclosed which comprises a polyester film before completion of orienting crystalization and, provided thereon, a sublayer comprising a copolymer containing 70 to 99.5 wt % of vinylidene chloride, and an antistatic layer comprising an ionic polymer, in that order. A coating solution is coated on the polyester film to form the sublayer with a dry thickness of 1 to 20 g/m.sup.2. The total solid content of the coating solution is not less than 4 wt %, and the coating solution contains a latex of the copolymer with an average particle size of 0.05 to 0.3 .mu.m. Heat is applied at a temperature not less than 30.degree. higher than the melting point of the copolymer, and the antistatic layer is formed on the sublayer.

Abstract: In order to coat with a uniform metal deposit the fibres of slivers to be used in the production of composite materials with a metallic or non-metallic matrix, it is proposed to use a spread fibre sliver (30) wound onto a feed spool (28) with an interpolated sheet (32). In order to avoid the deformation of the spread sliver, the latter is unwound by pulling on the interpolated sheet by means of an interpolated sheet receiving spool (34) driven by a motor (M1). Thus, the sliver travels by gravity in front of metallization means, such as rotary magnetron cathodes (40a, 40b). It is then rewound, together with a second interpolated sheet (46) onto a spool (42) driven by a motor (M2) via a brake (43) having a very limited torque.

Abstract: A metallized film combination of an oriented polymeric substrate layer having on one surface thereof a coating of a blend of (a) a vinyl alcohol homopolymer or copolymer and (b) an ethylene-acrylic acid copolymer, the coating blend having a metal layer thereon. The method involves coating the substrate after the substrate has been machine direction oriented and before the combination is transverse direction oriented followed by TD orientation and finally by depositing a metal layer on the blend surface.

Abstract: A differential pressure sealing apparatus and method for processing a continuously moving elongated sheet through successively different stages of vacuum. A vacuum chamber is provided with an inlet and a guide roller for the incoming sheet with the sheet urged against the guide roller over a wrap contact angle of 15 to 120 degrees. To resist the entrance of air into the chamber, a sealing structure encompasses at least portions of the entrance, the guide roller and the sheet.

Abstract: A coating for a thermoplastic film includes an acrylic copolymer, a finely divided wax in the amount of 30 to 150%, preferably 30 to 60%, by weight based on the total weight of the copolymer, a finely divided inorganic solid selected from the group consisting of silica, diatomaceous earth, calcium silicate, bentonite and finely divided clays in the amount of 5 to 25% by weight based on the total weight of the copolymer and either talc or Syloid in the amount of 0 to 1% based on the total weight of the copolymer. The coated film has a low haze, non-blocking and consistently low coefficient of friction for good machinability. The coating is applied to a surface of the film as an aqueous dispersion preferably by a gravure coater placed between the machine direction orienter and the transverse direction orienter in an extruding system for the film. This film can be laminated to another film such as glassine or a plastic film.

Abstract: This invention concerns the production of oriented polymeric films in which a layer of an ambient temperature curable silicone resin composition is formed on a layer of a polymeric film which is thereafter stretched at an elevated temperature to effect orientation of the film. The silicone resin composition includes a volatile inhibitor for inhibiting curing of the composition while stretching is effected. Suitable inhibitors include alkanols when the silicone resin has hydroxyl functionality. Films so produced can be used as release films.

Abstract: A coating head assembly for applying a coating material to a web, comprises an applicator block; a paint reservoir defined in the applicator block for the storage of the coating material; and a generally elongated nozzle integral with the applicator block and extending in a direction substantially transverse to the direction of transportation of the web. A free edge of the nozzle opposite to the applicator block has a generally curved nozzle face. This nozzle face has a plurality of applicator grooves defined therein in communication with the paint reservoir. During the passage of the web in sliding contact with the nozzle face, the coating material is supplied outwardly from the applicator grooves for the transfer thereof onto the web, resulting in the formation of a striped pattern of the coated layer on the web.

Abstract: A process for the preparation of a magnetic recording medium which comprises the steps of subjecting a magnetic recording layer coated on a nonmagnetic support to surface smoothening treatment, said magnetic recording layer comprising a ferromagnetic powder dispersed in a binder which is composed of a resin component and a curing agent, and then shaving a surface of said magnetic recording layer by means of a shaving device having high hardness.

Abstract: A method of producing decorative lengths of shot chain involves pre-heating the chain, initally applying a primer coat, reheating the primed chain, then subjecting one side of the chain to the application of paint of one color, reheating the chain to set that application, applying a different color to the other side of the chain and then baking to anneal the paint. The chain is then clipped to desired lengths. The method may be practiced either continuously or step-by-step.

Abstract: A process for producing a polyester film having a thin cured polyurethane coating, which comprises(1) applying an aqueous composition comprising a thermosetting polyurethane prepolymer as a film-forming component to at least one surface of an unoriented aromatic polyester film to form a thin wet coating on it, said polyurethane prepolymer being characterized by (i) having a polyol component at least 10% by weight of which is composed of a polyol containing a carbon-carbon double bond selected from unsaturated polyester polyols and polybutadiene polyols, the carbon-carbon double bond being cleavable under ultraviolet light, (ii) having a pendant anionic hydrophilic group in the polymer chain, and (iii) having isocyanate groups blocked with an oxime at the ends of the polymer chain, and(2) thereafter stretching and heat-setting the coated film, during which time the wet coating of the aqueous composition is dried and the polyurethane prepolymer is cured to form a thin cured polyurethane coating having a carbon-

Abstract: Method for producing a gas separation membrane comprising a microporous support having provided thereon a non-porous coating layer. The method comprises melt extruding a thermoplastic crystalline polymer under particular melt-extrusion conditions to form a precursor in the form of a hollow fiber or flat film, coating the precursor as a support with a coating substance composed of a natural or synthetic substance capable of forming a polymeric layer which does not form pinholes upon subsequent drawing after solidification to form a coating layer on the surface of the support, and solidifying the coating layer. The support is annealed either before or after the cooling process, and this is followed by cold drawing and heat setting the support to form the gas separation membrane.

Abstract: Process for the production of surface-finished, at least monoaxially stretched, thermoplastic films which are characterized in that the surface coating is imparted by means of slot doctoring systems before at least one stretching stage, and the subsequent stretching is carried out without contact with the surface.

Abstract: A method for producing a magnetic recording medium, comprising the steps of: (1) preparing a takeup evaporated article under a takeup tension of 13.5.times.10.sup.-8 b/t Kg-weight or more when a magnetic metal/alloy thin film is provided on a flexible substrate that is b mm wide and t m thick by takeup evaporation; (2) rewinding said evaporated article under a takup tension of 13.5.times.10.sup.-8 b/t Kg-weight or less; and (3) preserving said rewound article in an oxidation accelerating atmosphere. A method for producing a magnetic recording medium comprising the steps of: (1) preparing a takeup evaporated article by providing a magnetic metal/alloy thin film on a flexible substrate by takeup evaporation and (2) preserving said takeup evaporated article under the condition that an air stream containing an oxidizing gas is generated in winding gaps of said evaporated article.

Abstract: The invention concerns the production of oriented polymeric films in which a layer of a heat curable silicone resin composition is formed on a layer of a polymeric film which is thereafter stretched at an elevated temperature to effect orientation of the film. The heat curable silicone resin composition includes a volatile inhibitor for inhibiting curing of the composition while stretching is effected. Suitable inhibitors include volatile amines, alkynes and acetylene alcohols. Films so produced can be used as release films.

Abstract: A method of and an apparatus for making a magnetic recording tape, which is free from wrinkles formed thereon, by the use of a vapor deposition technique. A length of tape reeled on a supply reel is taken up by a take-up reel after having passed through a deposition station where it is movably turned around a cylindrical drum. In one aspect, the difference in tension between two different portions of the tape moving between the drum and the take-up reel and on respective sides of a tensioning roll forming a part of at least one tension control mechanism is adjusted to a value not greater than 10N/mm.sup.2. In another aspect, a charge eraser is employed and installed in the vicinity of the drum for removing an electrostatic charge built up in the tape being moved from the drum onto the take-up reel. In a further aspect, the cylindrical drum is used having its outer peripheral surface roughened to a ten-point average surface roughness of not smaller than 0.1 .mu.m.

Abstract: A polyester film having on at least one surface thereof a primer layer comprising a crosslinked product of a polyurethane having at least one functional group selected from a carboxyl group, a sulfo group, a hemisulfate group, and salts of these groups and a polyepoxy compound. The polyester film having a primer layer can be produced by coating an aqueous primer coating composition comprising a polyurethane having at least one of a carboxylic acid salt group, a sulfonic acid salt group and a hemisulfate salt group on at least one surface of a polyester film before its crystallization and orientation are completed, and thereafter completing the crystallization and orientation by subjecting the coated film to drying, stretching and heat-treatment, and is useful as a base film for magnetic recording media.

Abstract: A dual-coating method for use with a magnetic tape. A first coating solution is applied to a travelling support in an amount not exceeding 60 ml/m.sup.2. Within 5 seconds, a extrusion head pressed against the unsupported but tensioned moving support applies a second coating solution in an amount not exceeding 50 ml/m.sup.2.

Abstract: A heat-shrinkable barrier film comprised of an oriented polyolefin film coated on one side with a vinylidene chloride copolymer are disclosed. The films have excellent gas and vapor barrier properties, can surprisingly be made using conventional dispersion coating techniques, and retain acceptable optical properties even on shrinking up to as high as 35% in either transverse or machine directions or both.

Abstract: An array of at least three parallel rolls is provided. The rolls are constrained against each other to provide an elongated coating chamber through which passes a web entrained on at least one of the rolls. As it exits from the chamber, the coated web surface is wiped by another of the rolls, whose surface is entering the chamber at that point.

Abstract: A method for removal of curling of a circuit printable flexible substrate comprising a metal foil and a film layer of an aromatic polyamideimide or an aromatic polyimide formed by coating on the said metal foil a solution of an aromatic polyamideimide, an aromatic polyimide precursor or an aromatic polyimide, and drying the coated solution layer to setting, whose curling is produced to direct the metal foil surface to face outside, which comprises sliding under tension the curled circuit printable flexible substrate on a curved surface of a bar having a curvature radius of 0.5-25 mm, at which the substrate is turned back at a turning angle of not less than 90.degree., placing the metal foil layer in contact with the bar, at a temperature of not higher than 80.degree. C. A method employing two such bars is also disclosed.

Abstract: The invention provides a process for forming a magnetic thin film on a base film, a heat treatment process of a thin film sheet consisting of the base film and the magnetic thin film, and an apparatus for performing heat treatment of the thin film sheet. Tension applied to the thin film sheet is substantially equal to that applied to the base film when the magnetic thin film is formed thereon. Then, the thin film sheet is treated with heat. The thin film sheet is heated with a given temperature gradient to a reactive temperature at which heat shrinkage occurs, while the tension is being applied thereto. Thereafter, the thin film sheet to which the tension is still applied is cooled with substantially the same temperature gradient as applied in heating.

Abstract: The present invention provides a polyolefin film for electric insulation which is obtained by using a uniaxially drawn film of crystalline polyolefin, in which intramicrofibril and intermicrofibril amorphous parts of the uniaxially drawn film are impregnated with a low loss insulation oil, and which simultaneously satisfies the following conditions:(i) a tensile Young's modulus of the film impregnated with the insulation oil is 2.times.10.sup.4 kg/cm.sup.2 or higher;(ii) a dimensional change (change in length) of the uniaxially drawn film in the insulation oil at 100.degree. C. is within a tolerance of .+-.2%;(iii) a ratio of a long period at room temperature of an ether extraction residue of the uniaxially drawn film to a long period thereof before ether extraction is within a range of 0.900 to 0.998; and(iv) a dimensional increase of the ether extraction residue in the insulation oil at 100.degree. C. is 0.1% or higher.

Abstract: A method of manufacturing a magnetic recording film of a thin metallic film type comprises a step of forming a magnetic layer in the form of a thin metallic film on a base film, while providing a predetermined level of tension in the base film; a thermal treatment step of heating the film with the magnetic layer to a first temperature level, at which thermal shrinkage of the base film is caused, while providing the predetermined tension in the film; and, then, cooling the film, thereby removing any curls and wrinkles found therein; and an additional thermal treatment step of heating the thermally treated film to a second temperature level, which is lower than the first temperature level, and cooling the film, thereby removing thermal stress in the magnetic layer.

Abstract: A method of manufacturing a magnetic recording medium of thin metallic film type comprises, a first step of forming a thin magnetic metallic film layer on a base film which heat-contracts both in a first direction and in a second direction perpendicular to first direction, and a second step of heating the base film, while preventing the base film from heat-contracting in the first direction and thus heat-contracting the base film in the second direction, thereby making cracks in the thin magnetic metallic film layer which extend substantially parallel to the first direction of the base film.