Patents Assigned to Mutsui Petrochemical Industries
  • Acoustic material
    Patent number: 5098976
    Abstract: This invention provides an acoustic material having high elastic modulus and large internal loss by subjecting a high-modulus stretched polyethylene containing paraffin wax to plasma treatment. When the acoustic material of the present invention is used for a diaphragm of a speaker, for example, it is possible to suppress the fluctuation of frequency characteristics resulting from split vibration, decrease harmonic distortion and improve transient characteristics.
    Type: Grant
    Filed: April 14, 1989
    Date of Patent: March 24, 1992
    Assignees: Sony Corporation, Mutsui Petrochemical Industries
    Inventors: Masaru Uryu, Yoshio Nishi, Kazuo Yagi