Patents by Inventor David A. Chang

David A. Chang 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).

  • Pigmented rheopectic cleaning compositions with thixotropic properties
    Patent number: 5688435
    Abstract: A pigmented bleach-containing hard surface cleaner comprises an alkali metal hypochlorite, bentonite clay, a mono-(long chain alkyl)-tertiary amine oxide, an alkali metal salt, a pH stabilizer to attain a pH of 11 or higher, an alkali metal alkyl sarcosinate, an alkylbenzene sulphonate, and an inorganic pigment which is preferably ultramarine blue. The cleaning composition has excellent colour stability as well as phase stability and hypochlorite stability.
    Type: Grant
    Filed: March 18, 1996
    Date of Patent: November 18, 1997
    Assignee: Reckitt & Colman Inc.
    Inventors: David A. Chang, James W. Cavanagh
  • In-tank toilet dispenser
    Patent number: D392021
    Type: Grant
    Filed: January 27, 1997
    Date of Patent: March 10, 1998
    Assignee: Reckitt & Colman Inc.
    Inventors: Alan N. Bodker, David A. Chang
  • In-tank toilet dispenser
    Patent number: D392022
    Type: Grant
    Filed: January 27, 1997
    Date of Patent: March 10, 1998
    Assignee: Reckitt & Colman Inc.
    Inventors: Alan N. Bodker, David A. Chang
  • In-tank toilet dispenser
    Patent number: D395071
    Type: Grant
    Filed: August 11, 1997
    Date of Patent: June 9, 1998
    Assignee: Reckitt & Colman Inc.
    Inventors: Alan N. Bodker, David A. Chang