Abstract: 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.

Abstract: 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.

Abstract: The magnetic tape includes: a non-magnetic support; and a magnetic layer including ferromagnetic powder, in which a change amount of a loss tangent tan ? at a measurement temperature in a range of 50° C. to 100° C. before and after heating at 70° C. for 10 hours is 0.000 or more and 0.012 or less.

Abstract: 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.

Abstract: 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 —O—, —S—, or NR1—; each of R and R1 independently 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.

Abstract: 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.

Abstract: 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), A1 denotes a monovalent polymer group, each of R1 and R2 independently denotes a single bond or a divalent connecting group, R11 denotes a hydrogen atom or a monovalent substituent, m denotes an integer of equal to or greater than 2, multiple instances of R1, R2, A1, and R11 that are present can be identical or different, A2 denotes a hydrogen atom or a monovalent substituent denoted by —OR3—Z, R3 denotes a single bond or a divalent connecting group, Z denotes a monovalent acid group, among multiple instances of A2 that are present, at least one denotes a monovalent group denoted by —O—R3—Z, and X denotes a connecting group of

Abstract: 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, R1 denotes a single bond or a divalent connecting group, and m denotes an integer ranging from 2 to 4, multiple instances of A and R1 that 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.

Abstract: 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 —O—, —S—, or NR1—; each of R and R1 independently 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.

Abstract: The magnetic recording medium comprises a nonmagnetic layer comprising nonmagnetic powder and binder on a nonmagnetic support and a magnetic layer comprising ferromagnetic powder and binder on the nonmagnetic layer, wherein the magnetic layer comprises a lubricant and a 1-bromonaphthalene contact angle adjusting agent that is capable of adjusting a contact angle for 1-bromonaphthalene, the contact angle for 1-bromonaphthalene being measured on a surface of the magnetic layer, and the contact angle measured on the surface of the magnetic layer ranges from 45.0° to 55.0° for 1-bromonaphthalene, and ranges from 90.0° to 100.0° for water.

Abstract: 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, R1 denotes a single bond or a divalent connecting group, and m denotes an integer ranging from 2 to 4, multiple instances of A and R1 that 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.

Abstract: 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), A1 denotes a monovalent polymer group, each of R1 and R2 independently denotes a single bond or a divalent connecting group, R11 denotes a hydrogen atom or a monovalent substituent, m denotes an integer of equal to or greater than 2, multiple instances of R1, R2, A1, and R11 that are present can be identical or different, A2 denotes a hydrogen atom or a monovalent substituent denoted by —OR3—Z, R3 denotes a single bond or a divalent connecting group, Z denotes a monovalent acid group, among multiple instances of A2 that are present, at least one denotes a monovalent group denoted by —O—R3—Z, and X denotes a connecting group of

Abstract: 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.

Abstract: An aspect of the present invention relates to a magnetic recording medium comprising a magnetic layer comprising ferromagnetic powder and binder on a nonmagnetic support, wherein an average particle size of the ferromagnetic powder is equal to or less than 50 nm, the magnetic layer further comprises a compound, and the compound comprises at least one polyalkyleneimine chain and at least one polyester chain, with a proportion in the compound accounted for by the polyalkyleneimine chain being less than 5.0 weight percent and a number average molecular weight of the polyalkyleneimine chain ranging from 300 to 3,000.

Abstract: 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 R6 to R8 independently 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 —NH— 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).

Abstract: 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/?m2 or 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/?m2; 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.

Abstract: 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/?m2 or 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/?m2; 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.

Abstract: 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 R6 to R8 independently 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 —NH— 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).

Abstract: There is provided an optical information-recording medium, comprising a recording layer capable of recording of information by irradiation of a laser beam having a wavelength of 440 nm or less on or above a substrate, the recording layer comprising a dye having two or more independent dye moieties in the molecule that are bound to each other in a manner other than by forming a conjugated bond to the dye moieties, and a method of recording information, comprising recording information by irradiating a laser beam having a wavelength of 440 nm or less on or above the optical information-recording medium according to the present invention described above.

Abstract: There is provided an optical information recording medium including, on a substrate, a recording layer in which information can be recorded by irradiating a laser beam having a wavelength of 440 nm or less, wherein the recording layer includes an oxonol dye that has a maximum absorption wavelength longer than the wavelength of the laser beam. There is also provided an information recording method including irradiating a laser beam having a wavelength of 440 nm or less to the optical information recording medium to record information.