Patents Represented by Law Firm Barnes, Kisselle, Raisch, Whoate, Whittemore & Hulbert
  • Patent number: 5510175
    Abstract: A nonwoven cloth 1 comprising 100% vinal filaments is bonded and fixed with microporous aromatic polysulfone resin 6 incorporating fine through-holes 5 by the steps of; impregnating the nonwoven cloth 1 with an aromatic polysulfone resinous solution 3 prepared by dissolving the aromatic polysulfone resin in an organic solvent, subsequently immersing the cloth 1 impregnated with the aromatic polysulfone resinous solution 3 in a nonsolvent 4 so as to coagulate the aromatic polysulfone resinous solution 3, afterwards washing the cloth 1 with water, and finally drying the cloth 1. The polishing cloth 7 comprises this nonwoven cloth 1 bonded and fixed with the microporous aromatic polysulfone resin 6. Therefore, as far as the polishing cloth 7 is used, the porous structure of the resin is free from being deformed by heat and pressure added to the cloth during the polishing process and clogging of the polishing particles can also be prevented.
    Type: Grant
    Filed: March 1, 1995
    Date of Patent: April 23, 1996
    Assignee: Chiyoda Co., Ltd.
    Inventor: Kenichiro Shiozawa