Patents by Inventor Hubert Libera

Hubert Libera 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).

  • Stabilizer system for polyolefins comprised of monocarboxylic acid esters of a piperidinol and a benzophenone or benzotriazole
    Patent number: 4986932
    Abstract: A stabilizer system for stabilization of polyolefins against light, heat, and oxidative degradation, comprising:(a) a monocarboxylate ester of a polyalkyl-4-piperidinol of the formula: ##STR1## wherein R.sub.1 represents hydrogen, a C.sub.1-5 alkyl group, an allyl or benzyl group, or a C.sub.1-4 acyl group, and R.sub.2 represents a straight or branched chain, saturated or unsaturated C.sub.16-24 aliphatic carboxylic acyl group; and(b) a benzophenone or benzotriazole UV-absorber.
    Type: Grant
    Filed: June 15, 1988
    Date of Patent: January 22, 1991
    Assignee: Huels Aktiengesellschaft
    Inventors: Josef Disteldorf, Hans-Jurgen Haage, Hubert Libera, Peter Kirchner