METHOD OF PREPARATION OF ADDITIVE FOR LUBRICANTS Russian patent published in 2007 - IPC C10M159/18 

FIELD: petroleum chemistry; sulfur-containing compounds of molybdenum used as additives for lubricants reducing the friction coefficient.

SUBSTANCE: proposed method includes addition of ammonium thiomolybdate into homogeneous mixture of ammonium thiomolybdate and first modifying agent at equimolar ratio in the five-fold amount relative to the initial amount; then, second modifying agent in aromatic hydrocarbon solvent is introduced into mixture and homogenized mixture is subjected to heat treatment by boiling. Used as solvent for homogenization of mixture with the first modifying agent is bipolar aprotic solvent selected from the following series: N, N-dimethyl formamide, N, N-dimethyl acetamide, N-methyl-2-pyrrolidone or their mixtures, or dimethyl sulfoxide. Used as solvent for homogenization of mixture with the second modifying agent is o-xylol, m-xylol, p-xylol or their mixtures. Boiling is carried out with back-flow condenser at temperature of 140-150°C for -12 h. For separation of target product, use is made of petroleum ether, pentane, xehane, heptane, isooctane or their mixtures. Use may be also made of synthesized salt of thiomolybdic acid obtained from ammonium molybdate and inorganic ammonium sulfide. Used as first modifying agent is tetraalkyl ammonium salts or mixture of salts of common formula R¹R²R³R⁴NX, where R¹, R², R³ and R⁴ are similar or different and are selected from the group including C₁-C₁₆ alkyl, X=Cl, Br. Used as second modifying agent are derivatives of succinimide of the following common formula: where R⁵ is normal or branched alkyl or oligoalkylene at molecular mass of from 140 to approximately 1000; R⁶ is selected from group containing H, -C(=O)NH₂, -C(CH₂CH₂NH)_nCH₃; n= 1-4 or mixture of said succinimide derivatives.

EFFECT: increased content of molybdenum in final product; minimum friction coefficient at minimum amount of additive in lubricant.

6 cl, 3 tbl, 23 ex