Patents by Inventor Akitsugu Kawaguchi

Akitsugu Kawaguchi 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).

  • Bisurea light stabilizer for organic polymers
    Patent number: 5166234
    Abstract: A hydroxyphenyl-benzotriazole bisurea UV light stabilizer for organic polymers and a process for making it are provided. The stabilizer is particularly useful for spandex polymer yarns that are subjected to solvent scouring. A preferred stabilizer of the invention is a bisurea formed by reacting methylene-bis(4-phenyl-isocyanate) with 2-[2-hydroxy-3-(1,1-dimethylethyl)-5-(N-aminoethyl)propionamid-phenyl ]-2H-benzotriazole.
    Type: Grant
    Filed: November 30, 1990
    Date of Patent: November 24, 1992
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Akitsugu Kawaguchi
  • Bisbenzotriazoleureas as UV stabilizers for polymers
    Patent number: 5081258
    Abstract: A hydroxyphenyl-benzotriazole bisurea UV light stabilizer for organic polymers and a process for making it are provided. The stabilizer is particularly useful for spandex polymer yarns that are subjected to solvent scouring. A preferred stabilizer of the invention is a bisurea formed by reacting methylene-bis(4-phenylisocyanate) with 2-[2-hydroxy-3-(1,1-dimethylethyl)-5-(N-aminoethyl)propionamid-phenyl]-2H- benzotriazole.
    Type: Grant
    Filed: May 5, 1989
    Date of Patent: January 14, 1992
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Akitsugu Kawaguchi
  • Oligomeric semicarbazide additives for spandex
    Patent number: 5059647
    Abstract: A spandex fiber is provided with discoloration resistance by a synergistic combination of a hydroxyphenyl-1,3,5-triazine ultraviolet light absorber and N,N-dialkylsemicarbazide groups, the groups being attached to the ends of the spandex polymer or as a substituent of an additive.
    Type: Grant
    Filed: September 29, 1989
    Date of Patent: October 22, 1991
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Akitsugu Kawaguchi