Powdery molybdenum oxysulfide dithiocarbamate composition, a process for producing same, and a grease composition containing the composition

A process for production of a powdered molybdenum oxysulfide dithiocarbamate composition comprising a compound represented by the following formula (I):

• ##STR7## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are independent hydrocarbyl groups and may be the same or different groups, and wherein the total number of carbon atoms of R.sup.1 to R.sup.4 is 4 to 36;
• and X is sulfur or oxygen and the composition of the total of all Xs is represented by S.sub.m and O.sub.n in which m and n satisfy the ranges of 1.7.ltoreq.m.ltoreq.3.5 and 0.5.ltoreq.n.ltoreq.2.3, respectively, and in which the constituent particles have diameters of not larger than 50 .mu.m, comprising:
• reacting (a) molybdenum trioxide or an alkali metal salt or an ammonium salt of molybdic acid with (b) alkali hydrogen sulfide or alkali sulfide in a molar ratio of (a):(b)=1:1 to 1:2 in an aqueous medium, thereby preparing an aqueous solution or suspension (A) of a reaction product;
• reacting said reaction product (A) with (B) carbon disulfide, (C) secondary amine, and (D) a mineral acid in amounts such that the molar ratio of (A), (B) and (C) is (A):(B):(C)=1:0.9-2:0.9-2 and the amount of (D) reacted satisfies the expression:
• 1-[(R'/r)+1].times.1/10.ltoreq.d.ltoreq.1, wherein R' is the total number of carbon atoms present in R.sup.1, R.sup.2, R.sup.3 and R.sup.4 in the formula of the molybdenum oxysulfide dithiocarbamate compound above and d is the equivalent number of the mineral acid versus the alkali present in reaction product (A) when the alkali equivalent in reaction product (A) is defined as 1;
• separating the solid reaction product prepared from the solution or suspension;
• slurring the resulting reaction product in an organic solvent;
• and then, after separating the separated solid molybdenum oxysulfide dithiocarbamate product,
• washing, drying and powdering the solid product.