Abstract: 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.

Abstract: 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.

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.

Abstract: Liquid epoxy resins are produced by contacting a dihydroxy phenol with an excess of epihalohydrin and an aqueous solution of an alkali metal hydroxide in a molar ratio of hydroxide to phenol not exceeding 2:1, recovering from the reaction products an epoxy resin having a content of hydrolyzable chlorine of from 1 to 6% by weight, contacting a solution of the resin in a hydrocarbon with an aqueous solution of an alkali metal hydroxide while maintaining an atomic ratio of alkali metal to hydrolyzable chlorine contained in the resin of from 1:1 to 1.17:1 and recovering from the reaction products a liquid epoxy resin having a content of hydrolyzable chlorine less than 0.02% by weight.These epoxy resins of high purity are particularly useful as varnishes or coatings.