The Dow Chemical Company

Dow Global Technolgoies LLC

Roy E Smith

Warren H Griffin

Dennis R Lantz

Deborah L Kocsis

Clive P Bosnyak

Richard T Fox

Lawrence S Hood

Daniel A Beaudoin

John Gordon-Duffy

Van-Chau Vo

Deborah L Koesis

Creston D Shmidt

Prepare a closed-cell alkenyl aromatic polymer foam by an extrusion process using a blowing agent composition that contains at least 30 weight-percent of the chlorine-free hydrofluorocarbon blowing agent such that the foam has a density of 48 kilograms per cubic meter or less, contains more than 50 weight-percent styrene-acrylonitrile copolymer based on total polymer weight and at least eight weight-percent of a chlorine-free hydrofluorocarbon blowing agent that has a lower solubility in polystyrene than 1,1,2,2-tetrafluoroethane (HFC-134).

Alkenyl aromatic foam with low solubility hydrofluorocarbon

Disclosed is a process for making extruded, closed-cell alkenyl aromatic polymer foam structure having an average cell size of from about 0.3 to about 3.0 millimeters. The process comprises: a) heating an alkenyl aromatic polymer material having greater than 50 percent by weight alkenyl aromatic monomeric units to form a melt polymer material; b) incorporating into the melt polymer material at an elevated pressure a blowing agent comprising at least 50 percent by weight 1,1-difluoroethane (HFC-152a) based upon the total weight of the blowing agent to form a foamable gel; c) cooling the foamable gel to an optimum foaming temperature prior to extrusion through a die; and d) extruding the foamable gel through a die to form the foam structure. Further disclosed is a foamable gel capable of forming an alkenyl aromatic polymer foam structure having an average cell size of from about 0.3 to about 3.0 millimeters.

Foamable composition and process for making large cell size alkenyl

Disclosed is a process for making extruded, closed-cell alkenyl aromatic polymer foam structure having an average cell size of from about 0.3 to about 3.0 millimeters. The process comprises: a) heating an alkenyl aromatic polymer material having greater than 50 percent by weight alkenyl aromatic monomeric units to form a melt polymer material: b) incorporating into the melt polymer material at an elevated pressure a blowing agent comprising at least 50 percent by weight 1,1-difluoroethane (HFC-152a) based upon the total weight of the blowing agent to form a foamable gel: c) cooling the foamable gel to an optimum foaming temperature prior to extrusion through a die: and d) extruding the foamable gel through a die to form the foam structure. Further disclosed is a foamable gel capable of forming an alkenyl aromatic polymer foam structure having an average cell size of from about 0.3 to about 3.0 millimeters.

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Pickerington, OH, United States of America

Roy E Smith