Abstract: Thermal stability of halogen-containing polymers is improved by incorporation therein of (a) a compound of the formula: ##STR1## wherein R.sub.1 and R.sub.2 are independently selected from hydrogen, alkyl, aryl, alkyl- or alkoxy-substituted aryl, aralkyl, alkyl- or alkoxy-substituted aralkyl, or taken together form an alkylene radical of 3 to 9 carbon atoms; R.sub.3 and R.sub.4 are independently selected from alkyl of at least 4 carbon atoms, carbalkoxyalkyl, aryl, alkyl- or alkoxy-substituted aryl, aralkyl, alkyl- or alkoxy-substituted aralkyl or taken together form thiodimethylene, an ortho-arylene radical, an alkyl- or alkoxy-substituted ortho-arylene radical, or an alkylene radical of 2 to 4 carbon atoms; in combination with (b) a divalent metal salt of a carboxylic acid of 7 to 20 carbon atoms, or mixture of such metal salts.

Abstract: 2-Alkoxy-1,3-diphenyl-1,3-propanedione compounds have been found useful as photosensitizers in radiation-curable coating compositions. The novel photosensitizers of this invention have the structural formula ##STR1## in which R is an alkyl radical of from one eight carbon atoms.

Abstract: An ultraviolet radiation-curable composition is provided which comprises a polyethylenically unsaturated compound and effective photosensitizing amounts of (a) a phenacyl ester, and (b) a tertiary aliphatic amine.