Basic metal salts of sulfur- and methylene-bridged polyphenol compositions, and epoxide-reacted derivatives thereof, and lubricants containing them

A lubricating composition comprising a major amount of a lubricating oil and a minor lubrication-improving amount of an oil-soluble additive selected from the following:

• I. basic metal phenates prepared by reacting an excess of an alkali metal or alkaline earth metal base with (A) a separately sulfur- and methylene-bridged polyphenol composition prepared by reacting a phenol with formaldehyde or a reversible polymer thereof and subsequently sulfurizing the methylene-bridged intermediate thus obtained, or with (B) a separately sulfur- and methylene-bridged polyphenol composition prepared by sulfurizing said phenol and subsequently reacting the sulfurized intermediate thus obtained with formaldehyde or a reversible polymer thereof;
• the sulfurizing agent being sulfur or a halide thereof;
• Ii. reaction products of an epoxide with said sulfur- and methylene-bridged polyphenol composition (A) or (B);
• Iii. basic metal salts prepared by reacting an excess of an alkali metal or alkaline earth metal base with the epoxide reaction product of (II);
• Iv. reaction products of an epoxide with the basic metal phenate of (I).