Patents Assigned to YAMAGUCHI SEIKEN KOGYO CO., LTD.
  • POLISHING COMPOSITION AND METHOD FOR POLISHING MAGNETIC DISK SUBSTRATE
    Publication number: 20170015867
    Abstract: Embodiments of the invention provide a polishing composition including colloidal silica having an average particle size of 5 to 200 nm and pulverized wet-process silica particles having an average particle size of 0.1 to 1.0 ?m, wherein a value of the ratio of the average particle size of the wet-process silica particles to that of the colloidal silica is from 2.0 to 30.0. The polishing composition, according to various embodiments, achieves a high polishing rate and has a good surface smoothness, without the use of alumina particles.
    Type: Application
    Filed: September 28, 2016
    Publication date: January 19, 2017
    Applicant: YAMAGUCHI SEIKEN KOGYO CO., LTD.
    Inventors: Toru IWATA, Akira SUGAWA