Patents by Inventor Kenneth Alan Roberts

Kenneth Alan Roberts 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 preparing copolyesters of terephthalic acid ethylene glycol and 1 4-cyclohexanedimethanol exhibiting a neutral hue high clarity and increased brightness
    Patent number: 5681918
    Abstract: This invention relates to a three step process for preparing copolyesters exhibiting a neutral hue, high clarity and increased brightness. The process involves reacting terephthalic acid, ethylene glycol, and 1,4-cyclohexanedimethanol in a feed mole ratio of total glycols to dicarboxylic acid of 1.7:1 to 6.0:1, at a temperature of 240.degree. C. to 280.degree. C., and a pressure of 15 psig to 80 psig to form an esterification product; adding a polycondensation catalyst and a toner; and polycondensing the product at a temperature of 260.degree. C. to 290.degree. C. and a reduced pressure to form a high molecular weight copolyester.
    Type: Grant
    Filed: February 20, 1996
    Date of Patent: October 28, 1997
    Assignee: Eastman Chemical Company
    Inventors: Valerie Sue Adams, James Earl Hataway, Kenneth Alan Roberts