Heat-stabilized PVC compositions

Claim 1

A composition of matter comprising (1) a vinyl chloride polymer, and (2) heat-stabilizing amounts of (1) a mixture of metal salts of aliphatic and aromatic organic acids selected from the group consisting of calcium/zinc, calcium/cadmium, barium/zinc and barium/cadmium salts of aliphatic and aromatic organic acids, (ii) a polyol, and (iii) a β-diketone having the structural formula: R.sub.1 -- CO -- CHR.sub.2 -- CO -- R.sub.3 (I) wherein R 1 and R 3 , which can be identical or different, represent: a linear or branched chain alkyl or alkenyl radical having at least one and up to 36 carbon atoms, an aralkyl radical having from 7 to 36 carbon atoms, and an aryl or cycloaliphatic radical having fewer than 14 carbon atoms, the cycloaliphatic radicals optionally comprising carbon-to-carbon unsaturation; with the proviso that the foregoing radicals R 1 and R 3 either may or may not be substituted, and, when substituted, each said substituent is selected from the group consisting of halogen, or, in the case of the aryl or cycloaliphatic radicals, methyl or ethyl radicals; said R 1 and R 3 optionally may also be modified by the presence of one or more of the linkages --O--, ##STR5## or --CO--, in an aliphatic chain; and together R 1 and R 3 can also form a divalent alkylene radical of 2 to 5 carbon atoms, optionally containing a bridging oxygen or nitrogen atom; R 2 represents: a hydrogen atom, an alkyl or alkenyl radical, having at least one and up to 36 carbon atoms, which can contain one or more of the linkages --O--, ##STR6## or --CO--, a radical of the formula --CO--R 4 , R 4 representing an alkyl radical having from 1 to 36 carbon atoms, or an aryl radical having from 6 to 10 carbon atoms, or a radical of the formula ##STR7## R 5 representing an alkyl radical having from 1 to 6 carbon atoms, and R 1 and R 3 being as above; with the further proviso that; for R 1 and R 3 , the carbon atom bonded to the respective carbonyl function of the compound (I) is free from ethylenic or carbonyl unsaturation; for R 1 or R 3 , the carbon atom bonded to the respective carbonyl function does not comprise a moiety which includes aromatic unsaturation; one of the radicals R 1 or R 3 can represent a hydrogen atom; R 1 and R 2 together can represent a divalent radical selected from among the following: a linear or branched alkylene or alkenylene radical, having up to 36 carbon atoms, an aralkylene radical having from 7 to 36 carbon atoms, and an arylene or cycloalkylene radical having fewer than 14 carbon atoms, the cycloaliphatic radicals optionally comprising carbon-to-carbon unsaturation; and with the further proviso that such latter radicals too either may or may not be substituted, and, when substituted, each such substituent is selected from the group consisting of halogen, or, in the case of the aryl or cycloaliphatic radicals, methyl or ethyl radicals, and such latter radicals optionally being modified by the presence, in an aliphatic chain, of one or more of the linkages: ##STR8##