| abstract |
Thio-bis-(hydrocarbyl substituted diacid materials), such as thio-bis-(polyalkyl lactone acid) and/or their precursors, the adducts of sulfur chloride and unsaturated diacid materials, e.g., 4,8-bis-polyalkyl-4,8-dichloro-6-thiaundecane-1,2,10,11-tetracarboxylic acid bis-anhydride and their dehydrochlorinated analogs, when esterified with an alcohol, preferably a polyol, such as pentaerythritol, polypentaerythritol or a polyalkylene glycol with or without acid catalysts and/or metal template reagents yield thio-bis-(alkyl lactone acid esters) and thio-bis-(hydrocarbyl diacid esters) which can be characterized in part, as macrocyclic and/or macrocyclic-like structures, are useful as stable additives in lubricating compositions, e.g. as varnish inhibiting dispersants for lubricating oils and fuels. |