Metalworking lubricant composition containing a novel substituted malonic acid diester

A metalworking lubricant composition comprising

• (a) about 90-99 wt% mineral oil;
• and
• (b) about 1-10 wt% of a substituted malonic acid diester additive having the formula R.sub.1 R.sub.2 C(COOR.sub.3)(COOR.sub.4), wherein R.sub.1 is a C.sub.8 -C.sub.18 linear alkyl group or a C.sub.8 -C.sub.30 branched alkyl group;
• R.sub.2 is H or a C.sub.1 -C.sub.18 linear alkyl group or a C.sub.8 -C.sub.30 branched alkyl group;
• and R.sub.3 and R.sub.4 are C.sub.1 -C.sub.4 linear or branched alkyl groups, said diester additive being dissolved in said mineral oil.

A method for imparting lubricity and wear resistance to a metal surface, said method comprising applying to said surface a metalworking lubricant composition comprising

• (a) a minor proportion of a substituted malonic acid diester having the formula R.sub.1 R.sub.2 C(COOR.sub.3)(COOR.sub.4), wherein R.sub.1 is a C.sub.8 -C.sub.18 linear alkyl group or a C.sub.8 -C.sub.30 branched alkyl group or a C.sub.8 -C.sub.30 alkyl aryl group;
• R.sub.2 is H or a C.sub.1 -C.sub.18 linear alkyl group or a C.sub.8 -C.sub.30 branched alkyl group or a C.sub.8 -C.sub.30 alkyl aryl group;
• and R.sub.3 and R.sub.4 are C.sub.1 -C.sub.4 linear or branched alkyl groups;
• and
• (b) a major proportion of mineral oil, said substituted malonic acid diester constituting an additive dissolved in said mineral oil.