The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 04, 1994
Filed:
Jun. 08, 1993
Roy E Smith, Pickerington, OH (US);
Warren H Griffin, Granville, OH (US);
Deborah L Kocsis, Newark, OH (US);
Dennis R Lantz, Granville, OH (US);
The Dow Chemical Company, Midland, MI (US);
Abstract
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.