.beta.-diketones, processes for making .beta.-diketones and use of .beta.-diketones as stabilizers for PVC

A substantially odor-free, non-toxic, liquid stabilizing composition for halogenated polymers comprising an amount effective to stabilize halogenated polymers of a mixture of at least two substantially odor-free, non-toxic, liquid .beta.-diketone compounds represented by formula (I):

• R.sub.1 COCH.sub.2 COR.sub.2 (I)
• and/or formula (II)
• R.sub.2 COCH.sub.2 COR.sub.2 (II)
• wherein
• R.sub.1 is represented by the formula
• (Y).sub.n -.PHI.-,
• wherein .PHI. is phenyl and each Y, which may be the same or different, is a hydrogen atom or a group selected from
• hydrocarbon chains having 1 to 12 carbon atoms, alkoxy, silyl, and
• nonreactive halogen atoms;
• each R.sub.2, which may be the same or different, is a hydrogen atom or a group selected from
• hydrocarbon chains having 5 to 12 carbon atoms, aralkyl, or silyl;
• and
• n is an integer between 0 and 3;
• with the proviso that if the number of carbon atoms in R.sub.2 in formula (I) is less than 5, the sum of the carbons contained in the Y groups is at least 3 and at most 12, and that in formula (II), the total number of the carbon atoms in the two R.sub.2 s is at least 10.