Method of enhancing open cell formation in alkenyl aromatic polymer foams
AssigneeThe Dow Chemical Company
InventorsBharat I. Chaudhary, Bruce A. Malone
Life of this patent
Estimating the term…
Abstract
Disclosed is a method of enhancing open cell formation in making extruded alkenyl aromatic polymer foams of about 30 percent or more open cell content. Open cell formation is enhanced by incorporating into the foam an ethylene copolymer having a Vicat softening point of about 85.degree. C. or less. The ethylene copolymer is incorporated at from about 0.1 to about 7 percent based upon the weight of the alkenyl aromatic polymer material comprising the foam.
Claims16
A method of enhancing open cell formation in making extruded alkenyl aromatic polymer foams of about 50 percent or more open cell content, heating an alkenyl aromatic polymer material comprising greater than 50 weight percent of alkenyl aromatic monomeric units to form a polymer melt, optionally incorporating a nucleating agent into the polymer melt, incorporating a blowing agent into the polymer melt to form a foamable gel, the gel being cooled to a desirable foaming temperature, the foamable gel being extruded through a die into a region of reduced pressure to form the foam, wherein the improvement comprises incorporating into the polymer melt at from about 0.1 to about 7 percent based upon the weight of the alkenyl aromatic polymer material an ethylene copolymer having a Vicat softening point of about 85.degree. C. or less, the ethylene copolymer having an ethylene monomeric content of about 50 percent to about 97 percent based upon the total weight of the ethylene copolymer.
An extruded, open cell alkenyl aromatic polymer foam, the foam comprising:
- an alkenyl aromatic polymer material comprising greater than 50 percent by weight of alkenyl aromatic monomeric units, the foam having a density of about 16 to about 250 kg/m.sup.3, the foam having an average cell size of about 1.2 millimeters or less, the foam having an open cell content of about 50 percent or more, the foam having about 0.1 to about 7 percent of an ethylene copolymer an based upon the weight of the alkenyl aromatic polymer material, the ethylene copolymer having a softening point of about 85.degree. C. or less, the ethylene copolymer having an ethylene monomeric content of about 50 percent to about 97 percent based upon the total weight of the ethylene copolymer.
Dependencies are inferred from the claim text.