Fujifilm Corporation

Fuji Photo Film Company, Limited

Kazutoshi Katayama

Toshihide Aoshima

Tatsuo Mikami

Wataru Kikuchi

Kazuyuki Usuki

Takashi Imai

Yoshihisa Usami

Hiroshi Hashimoto

Hiroshi Kubo

Hisashi Mikoshiba

Tetsuya Watanabe

Makoto Nagao

Kousuke Watanabe

Masashi Aonuma

Ryuji Sugita

Hiroaki Araki

Kazuo Kato

Taro Hashizume

Toshichika Aoki

Tsuneo Yoshida

A magnetic tape management device includes a processor. The processor acquires a temperature and humidity of an environment in which a magnetic tape is stored, derives a specific enthalpy using the temperature and the humidity, and performs management processing on the magnetic tape in accordance with the specific enthalpy.

Magnetic tape management device, magnetic tape cartridge, magnetic tape, magnetic tape system, magnetic tape management method, and program

An aspect of the present invention relates to a composition, which is a composition for a magnetic recording medium and comprises an isocyanate compound in the form of an adduct of a polyhydroxyl compound having one or more aromatic carbon rings and three or more hydroxyl groups per molecule with a polyisocyanate having two or more isocyanate groups per molecule.

Composition for magnetic recording medium and magnetic recording medium

The magnetic recording medium comprises a magnetic layer comprising ferromagnetic powder and binder on a nonmagnetic support, and further comprises a compound denoted by Formula (1): wherein, in Formula (1), X denotes &#x2014;O&#x2014;, &#x2014;S&#x2014;, or NR&#x2014;; each of R and Rindependently denotes a hydrogen atom or a monovalent substituent; L denotes a divalent connecting group; Z denotes a partial structure of valence n comprising at least one group selected from the group consisting of carboxyl groups and carboxylate groups; m denotes an integer of greater than or equal to 2, and n denotes an integer of greater than or equal to 1.

Magnetic recording medium and coating composition for magnetic recording medium

An aspect of the present invention relates to a magnetic recording medium, which comprises a magnetic layer comprising ferromagnetic powder and binder on a nonmagnetic support, wherein the magnetic layer further comprises a compound which has a weight average molecular weight of equal to or more than 1,000 but less than 20,000 and is denoted by formula (1): wherein, in formula (1), Adenotes a monovalent polymer group, each of Rand Rindependently denotes a single bond or a divalent connecting group, Rdenotes a hydrogen atom or a monovalent substituent, m denotes an integer of equal to or greater than 2, multiple instances of R, R, A, and Rthat are present can be identical or different, Adenotes a hydrogen atom or a monovalent substituent denoted by &#x2014;OR&#x2014;Z, Rdenotes a single bond or a divalent connecting group, Z denotes a monovalent acid group, among multiple instances of Athat are present, at least one denotes a monovalent group denoted by &#x2014;O&#x2014;R&#x2014;Z, and X denotes a connecting group of valence m.

Magnetic recording medium and magnetic coating composition for magnetic recording medium

An aspect of the present invention relates to a magnetic recording medium, which comprises a magnetic layer comprising ferromagnetic powder and binder on a nonmagnetic support, wherein the magnetic layer further comprises a compound which has a weight average molecular weight of equal to or more than 1,000 but less than 20,000 and is denoted by formula (1): wherein, in formula (1), A denotes a monovalent substituent, Rdenotes a single bond or a divalent connecting group, and m denotes an integer ranging from 2 to 4, multiple instances of A and Rthat are present can be identical or different, at least one of the multiple instances of A that are present denotes a monovalent polymer group and X denotes a heterocyclic group of valence m.

A WORM-type recording layer in an optical information recording medium contains at least one azo-metal complex dye derived from a metal ion and a compound represented by the following general formula (1-1) or (1-2): wherein Q represents a carbocyclic group or a heterocyclic group, and Rto Rindependently represent a hydrogen atom or a substituent. The compound represented by the general formula (1-1) or (1-2) has a dissociative hydrogen atom in Q, and the dissociative hydrogen atom in Q and the hydrogen atom in the &#x2014;NH&#x2014; group marked with asterisk * are eliminated from the compound, so that the residue is bonded to the metal ion to generate the azo-metal complex dye. The azo-metal complex dye may contain a component other than the metal ion and the compound represented by the general formula (1-1) or (1-2).

Optical information recording medium and azo metal complex dye

An aspect of the present invention relates to a magnetic recording medium comprising a magnetic layer comprising a ferromagnetic powder and a binder on a nonmagnetic support. A height of protrusions with a protrusion density of 0.002 protrusion/&#x3bc;mor lower on a surface of the magnetic layer as measured by AFM is 40 nm or lower; a density of protrusions that are 15 nm or higher in height on the surface of the magnetic layer as measured by AFM ranges from 0.01 to 0.18 protrusion/&#x3bc;m; and the protrusions that are 15 nm or higher in height include protrusions formed of carbon black and protrusions formed of a substance with a Mohs' hardness exceeding 7, and an average height of the protrusions formed of carbon black is greater than an average height of the protrusions formed of the substance with a Mohs' hardness exceeding 7.

Magnetic recording medium, magnetic signal reproduction system and magnetic signal reproduction method

The present invention provides an optical information recording medium comprising a substrate having provided thereon a recording layer in which information can be recorded by laser light irradiation, wherein the recording layer contains a dye represented by the following formula (I):  wherein Dye represents a dye residue having a molar extinction coefficient of 10000 (cm&#xb7;mol) or more for light having a wavelength of 450 nm to 900 nm; L represents a divalent connecting group or a single bond; UV represents a dye residue having a molar extinction coefficient of 10000 (cm&#xb7;mol) or more for light having a wavelength of 280 nm to 450 nm; and m denotes an integer from 1 to 8.

Optical information recording medium

A method for manufacturing an optical disc and a method for transporting a multi-layered optical disc are provided. When adhering the sheet and the disc substrate, after the adhesive is supplied to the outer side of the groove on the disc substrate, the sheet is loaded on the disc substrate. The adhesive is pressed to extend to the groove. At this timer, because the surplus adhesive is blocked when flowing into the groove, the surplus adhesive does not overflow easily toward the inner side of the groove. In addition, even if the adhesive overflows toward the inner side of the groove the adhesive is kept between the non-adhered portion of the sheet and the disc substrate, preventing the adhesive from moving to the disc surface. The non-adhered portion is cut by the cutting blade after the adhesive is completely cured, and then removed from the disc substrate.

Method for manufacturing optical disc and method for transporting multi-layered optical disc

A method of manufacturing an optical information recording medium is provided with the steps of: immersing a substrate having guide grooves formed on both surfaces thereof into a recording-layer forming solution; raising the substrate from the recording-layer forming solution; and drying the substrate thus raised to form recording layers on both of the surfaces of the substrate.

Method of manufacturing optical recording medium

A magnetic recording medium comprising: a support; an undercoating layer; and a thin ferromagnetic metal layer, in this order, wherein the undercoating layer comprises a reaction product of a mixture comprising a compound represented by the following formula (I):R&#x2014;Si&#x2014;Xwherein R represents an organic group having 1 to 40 carbon atoms which may contain a functional group; X represents a hydrolyzable group; a is an integer of 0 to 3; and a+b is 4, and an oligomer of a compound represented by the formula (I) which comprises at least two siloxane bonds and has a viscosity of 4 to 100 mPa&#xb7;sec, the mixture comprising at least a compound represented by the formula (I) wherein b is 2 or greater.

Magnetic recording medium

A magnetic disk, comprising a magnetic layer, a protective layer, and a lubricating layer coated at least on one surface of a flexible non-magnetic support member or a rigid non-magnetic support member, wherein the protective layer comprises a carbon film containing hydrogen, nitrogen, and rare gas elements, nitrogen content is 0.5-8.0 atom %, and rare gas content is 0.5-1.2 atom %, and a magnetic recording mode using a floppy disk, wherein magnetic signal is recorded and reproduced using a floppy disk device provided with a carbon protective layer on the surface of the head or the slider.

Magnetic recording medium and magnetic recording mode using floppy disk

The present invention provides a master carrier for magnetic transfer, comprising a plurality of transfer information recording sectors having recording information magnetized thereon, a non-magnetic-material sector defining each of the transfer information recording sectors is present between each of adjacent transfer information recording sectors, and surfaces of the transfer information recording sectors and surfaces of the non-magnetic material sectors are positioned on and form the same plane.

Master carrier for magnetic transfer and method for transfer

A magnetic recording medium, comprising a magnetic layer containing a ferromagnetic metal thin film having micro-size projections on surface thereof and formed by vacuum film forming method and provided at least on one side of a nonmagnetic substrate, a carbon protective layer and a lubricant provided on said magnetic layer, a central axis of a diamond indenter of trilateral pyramid having a tip sharp angle of 90&deg; and a radius of curvature at tip of 35-50 nm being directed perpendicularly to the surface of the nonmagnetic substrate, pressure is applied on the carbon protective layer, and a load obtained when indentation depth of the indenter is 10-25 nm is divided by projection area of indenter contactor, and the quotient, i.e. micro-hardness, is within the range of 10-30 GPa.

The present invention discloses a magnetic recording particulate mediumhaving amagnetic layer on anonmagnetic support, the magnetic layer containing a ferromagnetic metal powder and a binder and having a coercive force of 1,400 to 1,700 Oe, wherein the ferromagnetic metal powder is spindle-shaped particles consisting essentially of Fe and having a Co/Fe ratio of from 1 to 5 atomic %, an Al/Fe ratio of from 5 to 15 atomic %, an average major axis length of 0.1 to 0.2 .mu.m and a specific surface area of 40 to 50 m.sup.2 /g, and the binder contains a polyurethane consisting essentially of a diol component comprising a polyether polyol and a polyester polyol and a polyisocyanate component. This magnetic recording particulate medium is characterized by minimal head wear, freedom from head clogging, and satisfactory electromagnetic characteristics.

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Odawara, Japan

Kazutoshi Katayama