Homogeneous compositions prepared from dimercaptothiadiazoles
AssigneeThe Lubrizol Corporation
InventorKirk E. Davis
Life of this patent
Estimating the term…
Abstract
Compositions which form homogeneous blends with lubricating oils and the like are produced by preparing a mixture of an oil-soluble dispersant (preferably a substantially neutral or acidic carboxylic dispersant) and a dimercaptothiadiazole, preferably 2,5-dimercapto-1,3,4-thiadiazole, usually with a diluent, especially a lubricant base liquid, and heating said mixture above about 100.degree. C. The compositions often contain dimercaptothiadiazole moieties in amounts substantially greater than stoichiometric. They are useful for suppression of copper activity and "lead paint" deposition in lubricants.
Claims17
A composition obtained by preparing a mixture comprising at least one ashless dispersant soluble in a lubricating oil and at least one dimercaptothiadiazole and heating said mixture at about 100.degree.-250.degree. C. until it is capable of forming a homogeneous blend with an oleaginous liquid of lubricating viscosity;
- about 0.1-10 parts by weight of said dispersant being present per part of said dimercaptothiadiazole.
A composition obtained by preparing a mixture comprising:
- 2,5-dimercapto-1,3,4-thiadiazole;
- a mineral oil;
- and
- a dispersant which is soluble in said mineral oil and which has a base number less than 7 or an acid number when titrated to a bromphenol blue end point,
- said dispersant being prepared by sequentially reacting a polyisobutenyl-substituted succinic acid in which the polyisobutenyl substituent contains at least about 50 carbon atoms with pentaerythritol and a polyethylene polyamine containing about 3-7 amino groups per molecule;
- and heating said mixture at about 100.degree.-250.degree. C. until it forms a homogeneous blend;
- about 0.1.degree.-10 parts by weight of said dispersant being present per part of 2,5-dimercapto-1,3,4-thiadiazole.
A lubricating composition comprising a major amount of a lubricating oil and about 0.05-20.0 parts by weight, per 100 parts of said lubricating oil, of a composition according to clam 16.
Dependencies are inferred from the claim text.