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:
Mar. 31, 1992
Filed:
Jun. 06, 1990
Yutaka Tamano, Tokuyama, JP;
Shuichi Okuzono, Shinnanyo, JP;
Masaki Ishida, Kudamatsu, JP;
Shoji Arai, Shinnanyo, JP;
Hiroyuki Yoshimura, Shinnanyo, JP;
Tosoh Corporation, Shinnanyo, JP;
Abstract
A process for producing a rigid polyurethane foam by use of a decreased amount of a CFC blowing agent and an increased amount of water used as a blowing agent, maintaining a high degree of heat insulation and improving the deterioration in friability of the product. The catalyst is one of the imidazoles represented by the formula (I): ##STR1## where R.sup.1 is alkyl having 1 to 4 carbons, benzyl, dimethylaminopropyl, or hydroxyalkyl having 1 to 3 carbons; R.sup.2 is hydrogen, alkyl having 1 to 4 carbons, allyl, or benzyl; and R.sup.3 and R.sup.4 are independently hydrogen, methyl, or hydroxymethyl.