Fujifilm Corporation

Kazufumi Omura

Masahiko Mori

Katsumi Araki

Keiichi Tateishi

Yasushi Hattori

Nobuo Seto

Masataka Yoshizawa

Masahiko Taniguchi

Hideo Hanawa

Masahide Sato

Hisashi Mikoshiba

Yoshihiko Fujie

Ryuji Shinohara

Kazushi Furukawa

Yoshiaki Nagata

Shinya Hayashi

Tomohiro Ichikawa

Shinji Tsujimoto

Yohei Aritoshi

Yoshinori Tamada

Yasushi Komori

Shingo Satoh

Tadahiro Ooishi

An object of the present invention is to provide a lactone compound having excellent water stability. Provided is a lactone compound represented by Formula (I). In Formula (I), Rand Reach independently represent a substituent which does not have a dissociative proton and has a Hammett's substituent constant σp value of −0.90 or more and −0.03 or less. Rrepresents a substituent which does not have a dissociative proton and has a Hammett's substituent constant σp value of −0.90 or more and −0.03 or less, or a hydrogen atom. Y represents a substituent and n represents an integer of 1 to 4. In a case where n is an integer of 2 to 4, a plurality of Y's may be the same substituent or substituents different from each other.

Lactone compound

Provided are a pigment dispersion liquid including a pigment, a polymer dispersant, and water; and an inkjet ink containing the pigment dispersion liquid. The pigment contains a compound represented by General Formula () described in the specification, a tautomer thereof, or a salt of the compound or the tautomer. The polymer dispersant contains a polymer compound which has a repeating unit represented General Formula (-) and a repeating unit represented General Formula (-) described in the specification, and having a structure represented by General Formula () introduced into at least one terminal of a main chain: in General Formula (), L represents a linking group; Rrepresents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group; and the symbol * represents a linking bond.

Pigment dispersion liquid and inkjet ink

An aspect of the present invention relates to a magnetic recording medium, which 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 further comprises carbon black, and a state in which the carbon black is present, as observed in a reflection electron image of a surface of the magnetic layer obtained by a scanning electron microscope, satisfies condition 1 and condition 2 below:

Magnetic recording medium

An aspect of the present invention relates to binder for a magnetic recording medium, which is vinyl chloride resin comprising at least one side chain, the side chain comprising at least one urethane bond and at least one monovalent sulfur-containing substituent denoted by formula (1):&#x2014;S-A-Z&#x2003;&#x2003;(1)

Binder for magnetic recording medium and method of manufacturing the same, composition for magnetic recording medium, and magnetic recording medium

The magnetic tape comprises a nonmagnetic layer comprising nonmagnetic powder and binder on a nonmagnetic support, and comprises a magnetic layer comprising ferromagnetic powder and binder on the nonmagnetic layer, wherein a fatty acid ester, a fatty acid amide, and a fatty acid are contained in either one or both of the magnetic layer and the nonmagnetic layer, with the magnetic layer and nonmagnetic layer each comprising at least one selected from the group consisting of a fatty acid ester, a fatty acid amide, and a fatty acid, a quantity of fatty acid ester per unit area of the magnetic layer in extraction components extracted from a surface of the magnetic layer with n-hexane falls within a range of 1.00 mg/mto 10.00 mg/m, and a weight ratio of the quantity of fatty acid ester per unit area of the magnetic layer to a combined total of a quantity of fatty acid amide and a quantity of fatty acid, quantity of fatty acid ester/(quantity of fatty acid amide+quantity of fatty acid), per unit area of the magnetic layer falls within a range of 1.00 to 3.00 in the extraction components.

Magnetic tape and method of manufacturing the same

The method of manufacturing hexagonal ferrite magnetic particles includes providing hexagonal ferrite magnetic particles by conducting calcination of particles comprising an iron salt and an alkaline earth metal salt to cause fertilization; and further includes preparing the particles comprising an iron salt and an alkaline earth metal salt by adhering a glass component, followed by the alkaline earth metal salt, to the iron salt; and conducting calcination of the particles prepared to form a calcined product in which hexagonal ferrite is detected as a principal component in X-ray diffraction analysis.

Method of manufacturing hexagonal ferrite magnetic particles, method of manufacturing magnetic coating material, and method of manufacturing magnetic recording medium

The method of manufacturing hexagonal ferrite magnetic particles, which includes providing hexagonal ferrite magnetic particles by conducting calcination of particles comprising an alkaline earth metal salt and an iron salt to cause ferritization; and further includes causing a glass component to adhere to the particles and then conducting the calcination of the particles to form a calcined product in which hexagonal ferrite is detected as a principal component in X-ray diffraction analysis; and removing the glass component from a surface of the calcined product that has been formed.

Method of manufacturing hexagonal ferrite magnetic particles

The composition is a composition for forming a thermally-cured coating film, and comprises polyurethane resin comprising at least one group selected from the group consisting of a methacryloyloxy group, an acryloyloxy group, a methacryloyl group, and an acryloyl group; polythiol; and solvent.

Composition for forming thermally-cured coating film and thermally-cured coating film

An aspect of the present invention relates to a method of manufacturing magnetic powder, which comprises adding an alkali metal salt compound comprising a substituent selected from the group consisting of an alkali metal salt of a carboxyl group and an alkali metal salt of a hydroxyl group to a water-based magnetic liquid comprising magnetic particles dispersed in an acidic water-based solvent to cause the magnetic particles to aggregate in the water-based magnetic liquid; and collecting the aggregated magnetic particles to obtain the magnetic powder.

Magnetic powder and method of manufacturing the same

An aspect of the present invention relates to a method of manufacturing magnetic particles, which comprises adding a carboxylic acid compound to a water-based magnetic liquid, wherein the water-based magnetic liquid comprises magnetic particles dispersed in an acidic water-based solvent, and the carboxylic acid compound is selected from the group consisting of aromatic compounds and aliphatic compounds having one or more carboxylic acid (salt) groups denoted by:&#x2014;COOMwherein M denotes a hydrogen atom or an alkali metal atom, when the number of the carboxylic acid (salt) group contained within the molecule thereof is 1, the number of carbon atoms, excluding the carboxylic acid (salt) group portion, ranges from 1 to 13; and then collecting the magnetic particles from the water-based magnetic liquid to obtain the magnetic particles the surfaces of which have been modified by being coated with the carboxylic acid compound.

Magnetic particles and method of manufacturing the same, and usage thereof

An aspect of the present invention relates to a method of manufacturing a vinyl polymer, which comprises: mixing a first liquid and a second liquid to conduct an addition reaction, wherein the first liquid has been obtained by reacting a sulfonic acid group-containing compound selected from the group consisting of taurine, N-methyl taurine, and meta-aminobenzenesulfonic acid with an alkali metal hydroxide in methanol, the second liquid comprises a vinyl polymer having an intramolecular epoxy group in a ketone solvent, and the addition reaction incorporates a sulfonic acid alkali metal salt group onto a side chain of the vinyl polymer.

Vinyl polymer and usage thereof

Method of manufacturing magnetic powder

An aspect of the present invention relates to a radiation-curable vinyl chloride resin composition comprising a vinyl chloride resin containing a radiation-curable functional group, and/or starting material compounds thereof, as well as a benzoquinone compound.

Radiation-curable vinyl chloride resin composition and magnetic recording medium using the same

An aspect of the present invention relates to a binder resin composition for a magnetic recording medium, which comprises a vinyl chloride resin containing a radiation-curable functional group, and a methacrylate compound denoted by formula (A): 

Binder resin composition for magnetic recording medium, method of manufacturing the same, and magnetic recording medium

An aspect of the present invention relates to a magnetic recording medium comprising a nonmagnetic layer comprising a nonmagnetic powder and a binder and a magnetic layer comprising a ferromagnetic powder and a binder in this order on a nonmagnetic support, wherein the magnetic layer and/or nonmagnetic layer comprises organic acid A and organic acid B below, with an acid strength pKa(A) of organic acid A and an acid strength pKa(B) of organic acid B satisfying a relation of pKa(A)&#x3c;pKa(B);

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Minami-ashigara, Japan

Kazufumi Omura