High voltage insulating compositions containing organic polymerizable phosphorus compounds

Claim 1

A high voltage insulating composition comprising (1) a polymer; (2) an additive effective in reducing tracking tracking; and (3) a phosphorus-containing compound which is selected from the group consisting of (a) organic polymerisable compounds having a formula selected from ##STR13## wherein n is selected from 0 to 1; t is an integer; p is integer greater than 1; X is independently selected from oxygen and sulphur; L is a t-valent organic group which, when t is 1, is selected from groups of formula --R and --XR; Q is independently selected from (i) monovalent groups of the formulae --R and --XR and (ii) divalent organic groups formed by two --R groups, two --XR groups or an --X group and an --R group attached to the same phosphorus atom, at least one of the Q groups being a group which renders said compound capable of polymerisation; and R is independently selected from (i) a hydrogen atom; (ii) an aryl group; (iii) a substituted aryl group; (iv) a group which renders the compound capable of polymerisation, which contains carbon and hydrogen and in which any other atoms are selected from fluorine, chlorine, oxygen, sulphur, nitrogen, phosphorus and silicon; (v) an alkyl group; and (vi) an alkyl group substituted by at least one group, each of said substituents consisting of at least one atom selected from carbon, hydrogen, fluorine, chlorine, oxygen, sulphur, nitrogen, phosphorus and silicon; (b) polymerisable salts of a compound in (a) containing a salt-forming acidic group, the cation in said salt being selected from ammonium and quaternary ammonium ions and metal ions wherein the metal is a metal having an atomic number less than 56 and belonging to one of Groups IA, IIA, IIB, IIIA, IIIB, IVA, IVB, VA, VB, VIA, VIIB, and VIII; and (c) products derived from the reaction of at least one compound as defined in (a) and (b) in the presence of the polymer to form higher molecular weight products.