Viscosity-temperature improver for lubricant

Abstract

The invention belongs to the field of lubricants and particularly relates to a viscosity-temperature improver for a lubricant. The viscosity-temperature improver is prepared by the following steps: adding a solvent (hexane) into a polymerization reaction vessel till the temperature is 10-50 DEG C; continually adding ethylene, propylene, styrene and hydrogen into the reaction vessel, wherein the molar ratio of hydrogen to ethylene to propylene to styrene is (0.1-0.3):(0.45-1):1:(0.8-1); performing stirring for a reaction for 1-3 h; adding a main catalyst (benzoyl peroxide) and an auxiliary catalyst (triethyl aluminum), wherein the addition of the main catalyst is 0.01-1% (by weight) of that of the solvent, and the weight of the auxiliary catalyst is 2-10 times of that of the main catalyst; stopping stirring after finish of the reaction; adding methyl alcohol for termination; washing with an alkaline solution; and performing vacuum drying to obtain a product (an ethylene, propylene and styrene copolymer). The viscosity-temperature improver for the lubricant can change such aggregative indicators as the viscosity-temperature performance, the thickening capability, the low-temperature performance and the dispersity of the lubricant, and ensures that the aggregative indicators are remarkably superior to like products at present.

Description

technical field [0001] The invention belongs to the field of lubricating oil, in particular to a viscosity-temperature improver for lubricating oil. Background technique [0002] Viscosity temperature improver is one of the indispensable additives of multi-grade engine oil, and its proportion is second only to detergent and dispersant. Statistics in the United States show that the amount of viscosity index improver is increasing at a rate of 12% per year. The essence of the viscosity-temperature improver is to improve the viscosity-temperature performance of the oil, so that the oil has a higher viscosity index, so as to ensure that the engine can start smoothly at low temperature, and the oil has sufficient viscosity at high temperature to ensure good lubrication . At the same time, it is required that the viscosity-temperature improver does not have obvious harmful effects on the oxidation stability and detergency of the oil, and the multi-grade engine oil has less viscos...

AI Technical Summary

Problems solved by technology

If the dry dosage is increased and the temperature is increased, the process cannot be controlled, so the product quality is unstable and the dispersion in use is poor. This is a major disadvantage of the thermal oxidation preparation method