Patents by Inventor Ryuji Kotani

Ryuji Kotani has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Rinsing agent, and method for production of hard disk substrate
    Patent number: 9187718
    Abstract: Provided are a rinsing agent to produce a hard disk substrate free from remaining abrasive grains as well as a pit defect on the surface thereof and a method for production of a hard disk substrate using such a rinsing agent. A rinsing agent of the present invention is rinsing solution containing colloidal silica as abrasive grains. Letting that the colloidal silica abrasive grains have a concentration C and an average grain size R (C and R are represented in weight % and nm, respectively), the concentration C and the average grain size R of the colloidal silica abrasive grains have a relation matching the following Expression (1): 12.2C+18.2??(1).
    Type: Grant
    Filed: July 19, 2011
    Date of Patent: November 17, 2015
    Assignees: Toyo Kohan Co., Ltd, Kohan Kogyo Co., Ltd.
    Inventors: Nobuhiro Iwamoto, Nobuaki Mukai, Kazutaka Arai, Ryuji Kotani
  • RINSING AGENT, AND METHOD FOR PRODUCTION OF HARD DISK SUBSTRATE
    Publication number: 20130122786
    Abstract: Provided are a rinsing agent to produce a hard disk substrate free from remaining abrasive grains as well as a pit defect on the surface thereof and a method for production of a hard disk substrate using such a rinsing agent. A rinsing agent of the present invention is rinsing solution containing colloidal silica as abrasive grains. Letting that the colloidal silica abrasive grains have a concentration C and an average grain size R (C and R are represented in weight % and nm, respectively), the concentration C and the average grain size R of the colloidal silica abrasive grains have a relation matching the following Expression (1): 12.2C+18.2 (1).
    Type: Application
    Filed: July 19, 2011
    Publication date: May 16, 2013
    Applicants: KOHAN KOGYO CO., LTD., TOYO KOHAN CO., LTD.
    Inventors: Nobuhiro Iwamoto, Nobuaki Mukai, Kazutaka Arai, Ryuji Kotani