Patents Assigned to Ecoplastics Limited
  • Patent number: 4883857
    Abstract: Condensation copolymers such as polyesters are rendered photodegradable, by subjecting them to conditions under which they undergo ester interchange effectively causing polymer chain scission, in the presence of a keto carbonyl containing compound having chemical groups reactive with the condensation polymer products formed by the ester interchange. The compound reacts chemically with the polymer products to reform the high molecular weight condensation copolymer, but with the keto carbonyl groups chemically linked into the polymer chains to confer photodegradability thereon.
    Type: Grant
    Filed: September 30, 1988
    Date of Patent: November 28, 1989
    Assignee: Ecoplastics Limited
    Inventors: James E. Guillet, Ilse Treurnicht, Ruey S. Li
  • Patent number: 4663412
    Abstract: Polymers of fluorene containing compounds which form crosslinked networks are found to provide useful negative photoresists which are sensitive in the ultraviolet wavelength range of between about 200 nm to 300 nm. When used in negative photoresist compositions, these fluorene compounds produce a high resolution and thus higher information density in microcircuits manufactured using these photoresists.
    Type: Grant
    Filed: July 2, 1986
    Date of Patent: May 5, 1987
    Assignee: Ecoplastics Limited
    Inventors: James E. Guillet, Anthony E. Redpath
  • Patent number: 4618566
    Abstract: Polymers of fluorene containing compounds which form crosslinked networks are found to provide useful negative photoresists which are sensitive in the ultraviolet wavelength range of between about 200 nm to 300 nm. When used in negative photoresist compositions, these fluorene compounds produce a high resolution and thus higher information density in microcircuits manufactured using these photoresists.
    Type: Grant
    Filed: October 31, 1984
    Date of Patent: October 21, 1986
    Assignee: Ecoplastics Limited
    Inventors: James E. Guillet, Anthony E. Redpath