Patents by Inventor Willard Alexander

Willard Alexander 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).

  • Process for the preparation of polybenzoxazole and polybenzothiazole filaments and fibers
    Patent number: 5976447
    Abstract: A continuous process for heating a polybenzazole or polybenzothiazole filament, which includes the step of heating the filament to a temperature of at least 100.degree. C. but no greater than 290.degree. C. while applying a tension thereto of at least 3.5 grams per denier, which is carried out at a line speed of at least 100 m/minute; and there is no prior or subsequent heating of the fiber to any temperature greater than 300.degree. C. It has been discovered that placing tension on the filament while it is dried increases its tensile modulus without a significant decrease in its tensile strength.
    Type: Grant
    Filed: June 24, 1996
    Date of Patent: November 2, 1999
    Assignee: Toyobo Co., Ltd.
    Inventors: Michael E. Mills, Willard Alexander, Timothy L. Faley, Chieh-Chun Chau