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:
May. 31, 1977
Filed:
Jul. 08, 1976
Silvio Vargiu, Casatenovo, (Como), IT;
Giancarlo Crespolini, Bergamo, IT;
Giulio Grazzini, Milan, IT;
Societa' Italiana Resine S.I.R. S.p.A., Milan, IT;
Abstract
Diepoxides of the general formula: ##STR1## wherein n has an average value not exceeding 0.03 and R is the bisphenyl radical of bisphenol-A are recovered from an epoxy resin of the same general formula with n varying from 0.07 to 0.30, by removing the low-boiling substance from the epoxy resin at 0.1-1 mm Hg and 165.degree.-200.degree. C and distilling off said diepoxide from the thus treated epoxy resin at 0.1-0.005 mm Hg and a temperature not exceeding 240.degree. C. The low viscosity, narrow molecular weight distribution and excellent purity of these diepoxides allow their use in critical application fields.