Mixed lithium-based grease for improving dropping point and thermal stability and preparation method thereof

Abstract

The invention provides a mixed lithium-based grease for improving dropping point and thermal stability, which comprises the following components by mass percentage: 80-95% of base oil; 1-3% of lithium hydroxide; 2.5-8% of fatty acid material; Anti-wear additive 0‑2%; rust inhibitor 0.2‑1%; antioxidant 0.5‑2; inorganic thickener 3‑5%. The present invention utilizes inorganic thickening agent to thicken on the basis of the traditional lithium-based grease manufacturing process, which not only improves the dropping point and thermal stability of the prepared lithium-based grease, but also improves the anti-wear ability of the prepared lithium-based grease.

Description

technical field [0001] The invention belongs to the field of lubricating materials, in particular to a lithium-based grease mixed for improving dropping point and thermal stability. Background technique [0002] Lithium-based grease is prepared by thickening mineral oil with hydroxy fatty acid lithium soap and adding various extreme pressure and anti-wear additives such as anti-oxidation, anti-rust and anti-corrosion. Lithium-based grease has excellent water resistance and mechanical stability , extreme pressure and anti-wear performance, water resistance and pumpability, rust resistance and oxidation stability, lithium-based grease can also exert its excellent lubricating performance under various harsh operating conditions, and the product can be used for a long time The temperature range is -20 to 120°C. Lithium-based grease has become the mainstream product of modern industrial grease because of its good lubricating performance and high dropping point. It currently account...

AI Technical Summary

Problems solved by technology

[0004] 1) The stability of the colloid is not good, and the storage tends to harden

Especially poor thermal stability, at 100 ℃ ambient temperature, it will dilute the consistency of a grade

It is easy to leak grease when used for bearing lubrication;

[0005] 2) The mechanical stability of lithium-based grease is not good in the production of lithium-based grease in an atmospheric pressure kettle. If the purity of raw materials changes, it will also affect the mechanical stability;

[0006] 3) The cost of lithium hydroxide remains high, resulting in a substantial increase in the price of lithium-based grease

[0007] The most commonly used inorganic thickeners are silica gel and bentonite, etc., and the particle size is required to be small, reaching the micron level, and can form a stable colloidal system in the dispersion medium (ie base oil). Generally, surface treatment must be done to make the surface Covered by organic compounds, it is lipophilic in order to have a good affinity with mineral lubricating oil. The preparation method mostly adopts the dispersion method, that is, by means of chemical force, that is, the solvent layer formed automatically on the surface of the dispersed phase in the dispersion medium or mechanical Force (high-speed dispersing equipment such as homogenizer and colloid mill) can achieve the purpose of uniform dispersion of solid-liquid system. Generally, because of its high dropping point and the ability to maintain the original consistency in a wide temperature range, it can It is used in the high temperature range where soap-based grease cannot reach. It is mostly used as special grease. It is used under some special conditions. The mechanical stability of inorganic grease is poor, and it cannot be used for high-speed parts.