Patents by Inventor Yukichira Kawakami

Yukichira Kawakami 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).

  • Production process for aromatic thioether ketone/thioether sulfone copolymers
    Patent number: 5484876
    Abstract: Disclosed herein are an aromatic thioether ketone/thioether sulfone random copolymer comprising phenylene thioether ketone recurring units (I) and phenylene thioether sulfone recurring units (II), (a) the compositional ratio (I:II) of the recurring units (I) to the recurring units (II) ranging from 98:2 to 65:35, (b) the solution viscosity (.eta..sub.inh) being at least 0.3 dl/g, (c) the melt crystallization time (.tau.) being at least 3 minutes, (d) the melting point (Tm) being 300.degree.-350.degree. C., (e) the glass transition temperature being at least 125.degree. C., (f) the retention (400.degree. C./20 min) of melt crystallization enthalpy (.DELTA.Hmc) being at least 60%, and (g) the average particle size being at least 0.1 mm, and the production process thereof.
    Type: Grant
    Filed: July 29, 1994
    Date of Patent: January 16, 1996
    Assignee: Kureha Kagaku Kogyo K.K.
    Inventors: Yukichira Kawakami, Zenya Shiiki