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:
Apr. 24, 1984
Filed:
Jul. 09, 1982
John D Carlson, Bradford Woods, PA (US);
Edward W Kifer, Trafford, PA (US);
Vincent J Wojtyna, Lyndora, PA (US);
James P Colton, Monroeville, PA (US);
Koppers Company, Inc., Pittsburgh, PA (US);
Abstract
Closed-cell phenolic foam having a uniform cell structure in which the cell walls are substantially free of both ruptures and perforations is disclosed. The phenolic foam has initial k values of less than 0.15 with substantially no increase of k value over time and good density and compressive strengths. The phenolic foam is prepared by foaming and curing a foamable phenolic resole composition containing an aqueous phenol formaldehyde resole, surfactant, fluorocarbon blowing agent, and optionally other additives with an acid foaming and curing catalyst in a substantially closed mold which exerts a restraining pressure on the foaming composition in excess of ambient atmosphericpressure of greater than about 3 pounds per square inch. The aqueous phenol formaldehyde resole is essentially a phenol formaldehyde condensation polymer having a molar ratio of formaldehyde to phenol of from about 1.7:1 to 2.3:1, preferably from 1.75:1 to 2.25:1 and most preferably about 2:1. The resole has a weight average molecular weight greater than 800 and preferably from 950-1500. The resole also has a number average molecular weight greater than about 350 and preferably from about 400 to about 600 and a dispersivity greater than about 1.7, preferably from 1.8 to 2.6. The acid foaming and curing catalyst is an anhydrous aryl sulfonic acid having a pKa less than about 2.0 and which changes the compatibility of the phenolic resole with water. The preferred anhydrous aryl sulfonic acid is a combination of toluene sulfonic acid and xylene sulfonic acid.