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:
Sep. 19, 2000
Filed:
Jul. 23, 1997
Howard Sims Hammel, Bear, DE (US);
Joseph Anthony Creazzo, Wilmington, DE (US);
E. I. du Pont de Nemours and Company, Wilmington, DE (US);
Abstract
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. The present invention further relates to compositions comprising a blowing agent and an active hydrogen-containing compound, commonly referred to in the art as B-side compositions or blends, and using such compositions for producing polyurethane and polyisocyanurate foams in which the blowing agent comprises a major proportion of 1,1,2,2-tetrafluoroethane (HFC-134).