Dispersant Or Surfactant Patents (Class 428/843.1)
  • Patent number: 11056141
    Abstract: The magnetic tape includes a non-magnetic support and a magnetic layer including ferromagnetic powder and a binding agent, in which the magnetic layer has a timing-based servo pattern, an edge shape of the timing-based servo pattern, specified by magnetic force microscopy is a shape in which a difference (L99.9?L0.1) between a value L99.9 of a cumulative distribution function of 99.9% and a value L0.1 of a cumulative distribution function of 0.1% in a position deviation width from an ideal shape of the magnetic tape in a longitudinal direction is 180 nm or less, and an isoelectric point of a surface zeta potential of the magnetic layer is 3.8 or less.
    Type: Grant
    Filed: January 30, 2020
    Date of Patent: July 6, 2021
    Assignee: FUJIFILM Corporation
    Inventors: Norihito Kasada, Eiki Ozawa, Atsushi Musha
  • Publication number: 20140287271
    Abstract: The magnetic recording medium comprises protrusions on a surface of a magnetic layer such that when protrusions of equal to or more than 8 nm in height as measured by AFM on the surface of the magnetic layer are divided into protrusions A formed of a spherical material and protrusions B formed of a non-spherical material, a value a, obtained by adding three times a standard deviation ? of heights of protrusions A to an average value of the heights of protrusions A, a value b, obtained by adding three times a standard deviation ? of heights of protrusions B to an average value of the heights of protrusions B, and a difference c, obtained by subtracting b from a, are calculated, conditions 13 nm?a?25 nm, 13 nm?b?25 nm, and 0.0 nm?c?10 nm are satisfied.
    Type: Application
    Filed: March 21, 2014
    Publication date: September 25, 2014
    Applicant: FUJIFILM Corporation
    Inventor: Masahide SATO
  • Publication number: 20120003503
    Abstract: An aspect of the present invention relates to a method of manufacturing a magnetic recording medium comprising dispersing magnetic particles in a water-based solvent having a pH that is lower than an isoelectric point of the magnetic particles to prepare a magnetic liquid, wherein the dispersing is conducted to a state of dispersion where a particle diameter in liquid is equal to or lower than 35 nm; adjusting a zeta potential of the magnetic particles to within a range of 0 to 25 mV by modifying a surface of the magnetic particles with the addition of a prescribed surface-modifying agent to the. magnetic liquid; dispersing the magnetic particles after the adjusting together with an organic solvent and a binder to prepare a magnetic coating material; and forming a magnetic layer of the magnetic recording medium with the magnetic coating material that has been prepared.
    Type: Application
    Filed: July 1, 2011
    Publication date: January 5, 2012
    Applicant: FUJIFILM CORPORATION
    Inventor: Masahiko MORI
  • Publication number: 20100055504
    Abstract: An aspect of the present invention relates to a method of modifying a surface of a powder, comprising mixing a powder with a compound denoted by general formula (I): wherein, in general formula (I), each of R10 and R13 independently denotes a hydrogen atom, alkyl group, or aryl group, each of R11 and R12 independently denotes an alkyl group or an aryl group, and L denotes a single bond or an oxygen atom.
    Type: Application
    Filed: August 26, 2009
    Publication date: March 4, 2010
    Applicant: FUJIFILM Corporation
    Inventor: Kazufumi OMURA