Patent ID: 8349937

Claim:
An insulating resin for insulating compositions in switchgear formed from the starting components comprising: a) a material containing at least one anhydride selected form the group consisting of a mixture of methyl isomers of methylbicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic anhydride and hydrogenated mixture of methyl isomers of methylbicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic anhydride, b) a material containing an imidazole of the following structure: where R1 is selected from the group consisting of alkyl, long-chain alkyl, alkenyl, cycloalkyl, haloalkyl, aryl; R 2 , R 3 , R 4 are each independently selected from the group consisting of hydrogen, alkyl, long-chain alkyl, alkenyl, cycloalkyl, haloalkyl, and aryl; where one or more nonadjacent CH2 groups in suitable radicals may each independently be replaced by —O—, —S—, —NH—, —NR o —, —SiR o R oo —, —CO—, —COO—, —OCO—, —OCO—O—, —SO2-, —S—CO—, —CO—S—, —CY1=CY2- or —C≡C—, such that oxygen and/or sulfur atoms are not bonded directly to one another, and are likewise optionally replaced by aryl or heteroaryl preferably containing 1 to 30 carbon atoms, with terminal CH3 groups being understood as CH2 groups in a sense of CH2-H, where R o and R oo =alkyl; and c) a filler comprising alumina flakes; d) a resin based on glycidyl esters: said components formed into said resin, wherein a ratio of material a) to material b), in weight:weight, lies between ≧50:1 and ≦300:1 and a proportion of material a) in the resin based on glycidyl esters, in weight:weight is from ≧0.8:1 to ≦1:1.