Preparation method of molybdenum-sulfur complex lubricating oil additive with high molybdenum content

Abstract

The invention discloses a preparation method of a molybdenum-sulfur complex lubricating oil additive with high molybdenum content. The preparation method comprises the following steps: I, preparing a mixed liquid A from a hexavalent molybdenum compound, a sulfur-containing compound and distilled water, and then adjusting a pH value; II, adding dialkyl amine into the mixed liquid A which is subjected to pH value adjustment, then stirring, and then adding a phase transfer catalyst to obtain a mixed liquid B; III, under the protection of a nitrogen atmosphere, dropwise adding carbon disulfide into the mixed liquid B to obtain a mixed liquid C; and IV, standing the mixed liquid C till the mixed liquid C is layered, removing a water phase, washing an organic phase by virtue of an alkaline solution and an organic solvent, then distilling, and drying to obtain the high-molybdenum-content molybdenum-sulfur complex lubricating oil additive of which the mass percentage content of molybdenum is not less than 10%. The preparation method disclosed by the invention is simple in preparation process, and is favorable for industrial production; and the prepared molybdenum-sulfur complex lubricating oil additive has relatively high molybdenum content and good oil solubility, and after the additive is added into lubricating oil, the anti-wear and friction reduction properties of the lubricating oil can be greatly improved.

Description

Technical field [0001] The invention belongs to the technical field of lubricating oil additive preparation, and in particular relates to a method for preparing a high-molybdenum content molybdenum-sulfur complex lubricating oil additive. Background technique [0002] As a solid lubricant, MoS 2 It has been used for hundreds of years, and it has been suspended in oil and grease in powder form for 60 to 70 years. Due to MoS 2 It is insoluble in organic systems, which limits its application. In the 1970s, oil-soluble organic molybdenum compounds began to be used in lubricants. At low concentrations, oil-soluble organic molybdenum compounds are better than MoS 2 More effective, as an extreme pressure antiwear agent and friction modifier, it can reduce friction and wear on sliding surfaces in lubricating oil and grease, improve load capacity, and is also an excellent antioxidant, and can save energy by 3% to 4% . [0003] The development of organic molybdenum has gone through four s...

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Problems solved by technology

[0005] Molybdenum dialkyldithiophosphate (MoDDP), which appeared in the 1970s, due to its high phosphorus content, affects the poisoning of exhaust gas catalysts, so its use has begun to be greatly reduced abroad; the inactive organic molybdenum that does not contain sulfur and phosphorus Most of them are molybdenum complexes, which have no pollution and will not poison the catalyst, but their tribological properties are still not as good as sulfur-containing molybdenum compounds; and the trinuclear molybdenum-sulfur compounds that have appeared in recent years are difficult to prepare and cost Expensive and, therefore, have not been widely used

[0008] The organomolybdenum compound prepared by the above method has defects such as poor oil solubility, low molybdenum content and deep color, and it is urgent to develop a method for preparing an organomolybdenum compound with a simple process and high molybdenum content with excellent anti-wear and wear-reducing properties.

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