Alumina Particle (i.e., A12o3) Patents (Class 428/844.3)
  • Patent number: 11430478
    Abstract: Provided are a magnetic tape including: a non-magnetic support; a magnetic layer including ferromagnetic powder and a binding agent on one surface side of the non-magnetic support; and a back coating layer including non-magnetic powder and a binding agent on the other surface side of the non-magnetic support, in which an isoelectric point of a surface zeta potential of the magnetic layer is equal to or greater than 5.5, and an isoelectric point of a surface zeta potential of the back coating layer is equal to or greater than 4.5, a magnetic tape cartridge, and a magnetic tape apparatus including this magnetic tape.
    Type: Grant
    Filed: December 26, 2019
    Date of Patent: August 30, 2022
    Assignee: FUJIFILM Corporation
    Inventor: Norihito Kasada
  • Patent number: 11100949
    Abstract: Provided is a magnetic recording medium including: a non-magnetic support; and a magnetic layer including particles of at least one kind of epsilon type iron oxide-based compound selected from the group consisting of ?-Fe2O3 and a compound represented by Formula (1), an abrasive, and a binding agent, at least on one surface of the non-magnetic support, in which an average equivalent circle diameter of the particles of the epsilon type iron oxide-based compound is 7 nm to 18 nm, an average equivalent circle diameter of the abrasive in a plan view of the magnetic layer is 20 nm to 1,000 nm, and a coefficient of variation of the equivalent circle diameter of the abrasive is 30% to 60%. In Formula (1), A represents at least one kind of metal element other than Fe and a satisfies a relationship of 0<a<2. ?-AaFe2-aO3??(1).
    Type: Grant
    Filed: June 4, 2018
    Date of Patent: August 24, 2021
    Assignee: FUJIFILM Corporation
    Inventors: Masashi Shirata, Takashi Fujimoto
  • Patent number: 7854984
    Abstract: A decorative laminate having improved scratch and abrasion resistance is provided. In one embodiment, the decorate laminate includes a substrate or core, a decorative sheet on the substrate, and an overlay sheet on the decorative sheet. The overlay sheet is coated on both major surfaces to provide scratch and abrasion resistance to the laminate. The coating on the interior facing surface contains mineral particles having a particle size of from between about 10-30 microns. The coating on the exterior facing surface contains a mixture of first mineral particles having a particle size of from between about 3-8 microns and second mineral particles having a particle size of less than about 1.0 micron. The first mineral particles are preferably alumina particles, and the second mineral particles are preferably sol gel process alumina particles.
    Type: Grant
    Filed: May 3, 2005
    Date of Patent: December 21, 2010
    Assignee: The Diller Corporation
    Inventors: Kevin Francis O'Brien, Frederic Auguste Taillan
  • Patent number: 7517598
    Abstract: A magnetic recording medium having a non-magnetic support and a magnetic layer formed thereon, wherein the magnetic layer comprises a ferromagnetic powder, a binder and a non-magnetic inorganic powder, and wherein at least 95% of the non-magnetic powder particles contained in the magnetic layer have a particle size of 0.05 to 0.013 ?m, provide that the non-magnetic powder particles are those found in a field of view of 1.8 ?m×2.4 ?m when the surface of the magnetic layer is observed with a scanning electron microscope at a magnification of 50,000 times.
    Type: Grant
    Filed: January 10, 2007
    Date of Patent: April 14, 2009
    Assignee: Hitachi Maxell, Ltd.
    Inventors: Ken Yoshimura, Tetsutaro Inoue
  • Patent number: 7186472
    Abstract: A magnetic recording medium comprising a support and a magnetic layer containing an abrasive, a binder and ferromagnetic powder dispersed in the binder, wherein the magnetic layer has a thickness of from 20 to 500 nm, the abrasive has a Mohs' hardness of 5 or more and a relative abrasive velocity of less than 200, and value A of a relational expression A=K/Z of an average particle size K of the abrasive and the thickness Z of the magnetic layer is from 0.1 to 3.0.
    Type: Grant
    Filed: May 25, 2004
    Date of Patent: March 6, 2007
    Assignee: Fuji Photo Film Co., Ltd.
    Inventor: Noboru Zinbo
  • Patent number: 7175927
    Abstract: A magnetic recording medium having a non-magnetic support and a magnetic layer formed thereon, wherein the magnetic layer comprises a ferromagnetic powder, a binder and a non-magnetic inorganic powder, and wherein at least 95% of the non-magnetic powder particles contained in the magnetic layer have a particle size of 0.05 to 0.013 ?m, provide that the non-magnetic powder particles are those found in a field of view of 1.8 ?m×2.4 ?m when the surface of the magnetic layer is observed with a scanning electron microscope at a magnification of 50,000 times.
    Type: Grant
    Filed: November 9, 2004
    Date of Patent: February 13, 2007
    Assignee: Hitachi Maxell, Ltd.
    Inventors: Ken Yoshimura, Tetsutaro Inoue
  • Patent number: 7011900
    Abstract: A magnetic recording medium is prepared by coating a dispersion of non-magnetic powder and ferromagnetic powder in a binder and a dispersion of ferromagnetic powder in a binder to a non-magnetic substrate by a wet-on-wet coating technique to form subordinate and magnetic layers on the substrate, and subjecting the layers to magnetic field orientation. The subordinate layer has a Br of 80 to 400 gauss, and the magnetic layer has a thickness of 0.1 to 0.4 ?m. The medium has surface smoothness and good electromagnetic characteristics and lends itself to recording and reproducing signals having a minimum wavelength of 0.2 to 0.7 ?m.
    Type: Grant
    Filed: March 23, 2004
    Date of Patent: March 14, 2006
    Assignee: TDK Corporation
    Inventors: Akihiko Seki, Takayoshi Kuwajima, Naoto Yajima