E.i. Dupont De Nemours and Company

Robert O York

Howard S Hammel

An improved closed cell polymer foam and foaming agent involving the use of a hydrogen-containing halocarbon blowing agent (e.g., HCFC-22) in combination with an effective amount of a hydrogen bond forming blocking agent (e.g., organic ether, ester or ketone). The presence of the blocking agent is shown to significantly reduce the escape of blowing agent from and entry of air into the foam resulting in low thermal conductivity over a longer period of time and improved thermal insulation value. A closed cell thermoplastic foam such as polyethylene, polypropylene, polystyrene, among others, is disclosed produced by means of an environmentally friendly nonflammable blowing agent substantially free of halogen substituents other than fluorine and comprising HFC-134 (1,1,2,2-tetrafluoroethane).

Polymer foams containing blocking agents

This invention relates to the use of polyfluorocarbon blowing agents in the preparation of polymer foams; particularly the use of 1,1-difluoroethane in the preparation of polystyrene foams for food packaging and food serving.

Polystyrene foams containing 1,1-defluoroethane

Foam blowing agent composition and process for producing foams

Closed cell rigid polyhydroxy acid resin compositions foamed with environmentally benign, which compositions are degradable and cause minimal environmental impact when discarded.

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Wilmington, DE, United States of America

Robert O York