Societa' Italiana Resine S.i.r. S.p.a.

Euteco, S.p.a.

Mario Pitzalis

Silvio Vargiu

Giancarlo Crespolini

Edoardo Carpaneti

Gino Giuliani

Giorgio Lazzerini

A Novolak epoxy resin is prepared by adding an aqueous solution of alkali metal hydroxide to a solution of Novolak phenolic resin in epichlorohydrin, distilling off water during said addition in the form of an azeotrope with epichlorohydrin and recycling the latter, while maintaining the reaction medium at 60-80.degree. C and at a pH between 7 and 8 and a water content of from 0.5 to 2.5 wt.% in said medium. The thermosetting resin thus obtained can be used in applications requiring resins with low chlorine contents, low viscosity and high epoxy value.

Preparation of novolak epoxy resins

A liquid epoxy resin is produced by gradually feeding an aqueous solution of alkali metal hydroxide into a solution of bisphenol-A in epichlorohydrin, while maintaining the reaction medium at boiling point, distilling off water in the form of an azeotrope with epichlorohydrin and recycling the latter, and maintaining a water content of from 0.1 to 0.7 wt.% and a pH value between 7 and 9 in said reaction medium. The liquid epoxy resins thus obtained have low values of the viscosity, epoxy equivalent and hydrolyzable chlorine content.

Preparation of liquid epoxy resins from bisphenols

Petroleum resins are prepared by subjecting to pre-polymerization a hydrocarbon fraction containing olefins and diolefins, having a boiling range of from 30.degree. to 300.degree. C, in the presence of activated clays, recovering from the pre-polymerization products a selected hydrocarbon fraction having a boiling point not exceeding 250.degree. C, mixing this selected fraction with a hydrocarbon fraction containing unsaturated hydrocarbons with an average of 5 carbon atoms per molecule, subjecting the resulting mixture to polymerization in the presence of a Friedel-Crafts catalyst and recovering the petroleum resins from the polymerization products. These petroleum resins form homogeneous mixtures with rubber.

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Arcore (Milan), Italy

Mario Pitzalis