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. 27, 1994
Filed:
Jul. 23, 1993
Kiyohiro Yuge, Yawata, JP;
Hitoshi Muramatsu, Tokyo, JP;
Yasuto Masuda, Shimamoto, JP;
Kazutaka Uekado, Nishinomiya, JP;
Yasuaki Tanimoto, Nishinomiya, JP;
Abstract
A method of producing an open cell rigid polyurethane foam which comprises reacting a polyol with a polymethylene polyphenyl polyisocyanate prepolymer with a monool exemplified by diethylene glycol monomethyl ether by use of a substitute such as 1,1-dichloro-1-fluoroethane or methylene chloride as a volatile blowing agent, or a mixture of the volatile blowing agent with water, for trichlorofluoromethane as a blowing agent in the presence of a catalyst, a foam stabilizer and a cell opening agent. The resultant open cell rigid polyurethane foam has a cell size of about 200-250 microns, and is suitable for use, for example, as a core material in a vacuum heat insulating material. The foam may be enclosed in a container under a vacuum of 0.1-0.01 mmHg readily attainable to provide a vacuum heat insulating material of a high heat insulating performance.