Abstract: The invention relates to electrical insulators having increased resistance to partial discharges and electrical equipment comprising such electrical insulators.These electrical insulators are formed of a macromolecular material in which is incorporated a chelate which is a derivative of an organic compound of general formula: ##STR1## wherein: R is CH.sub.2 COOM or --OH,M is Na or H,x is an integer from 1 to 4,n is an integer from 0 to 4,the metal chelate being present in the material in an amount sufficient for promoting the extinction of partial discharges, said amount not exceeding a value which would alter the physical properties of the insulator such as the volume resistivity thereof.

Abstract: The invention relates to electrical insulators having increased resistance to partial discharges and electrical equipment comprising such electrical insulators.These electrical insulators are formed of a macromolecular material in which is incorporated a chelate of general formula: ##STR1## wherein: R.sub.1, R.sub.2 and R.sub.3 each represent hydrogen or a alkyl, aryl, or cycloalkyl group or a heterocyclic group containing a sulphur, oxygen or nitrogen atom, whereby said group or heterocyclic group may be substituted by one or more halogen atoms;X and Y represent oxygen or sulphur;The total number of carbon atoms in the metal chelate is between 5 and 25;M.sup.n+ stands for a metal ion, andN is an integer from 1 to 4, this enolate or thioenolate being present in said insulating material in a sufficient amount for promoting extinction of partial discharges, said amount not exceeding a value which would substantially alter the physical properties of the insulator, such as its volume resistivity.