Improver for combined lubricating oil and preparation method thereof

Abstract

The invention discloses a combined lubricating oil improver and a preparation method thereof. The combined lubricating oil improver comprises the following components: a semi-crystalline ethylene propylene copolymer with a mass fraction of 0.3-1%, 10 ‑60% polyisobutylene, the remainder is base oil. The preparation method of the improver of the combined lubricating oil includes: S1, adding the solid block of ethylene-propylene copolymer under the protection of nitrogen, and stirring until the solid block of ethylene-propylene copolymer and base oil under the condition of 110-130°C Fully fused to form a transparent fluid glue; S2, at a temperature of 50-70°C, add polyisobutylene until it is completely fused to form a transparent flowing mixed glue; S3, the mixed glue obtained in step S2 After cooling to normal temperature, the improver of combined lubricating oil is obtained. The invention has the advantages of good low-temperature fluidity and good shear resistance, and can be widely used in the technical field of lubricating oil improvers.

Description

technical field [0001] The invention relates to the technical field of lubricating oil improvers. More specifically, the present invention relates to a combination lubricating oil improver and a preparation method thereof. Background technique [0002] In order to improve the viscosity-temperature performance of lubricating oil, polymer compounds were added to lubricating oil in the 1930s, and polyisobutylene PIB appeared in lubricating oil in the mid-1930s. However, due to poor low-temperature fluidity, it is not suitable for direct use in multi-stage internal combustion engines. Oil, ethylene propylene copolymer OCP appeared in the 1960s and 1970s. Its low-temperature fluidity has improved, but its shear resistance is average. The shear resistance is related to its molecular weight. The shear resistance of larger molecular weight is poor. The hydrogenated styrene-diene copolymer HSD has been developed, which has better low-temperature fluidity and improved shear resistanc...

AI Technical Summary

Problems solved by technology

[0003] At present, in the lubricating oil industry, a single type of viscosity index improver is added to the lubricating oil. Because one viscosity index improver has advantages in one aspect and has disadvantages in others, for example, polyisobutylene PIB has excellent shear resistance. It has a certain anti-oxidation performance, but its low-temperature fluidity is relatively poor, so it is not suitable for direct use in multi-grade internal combustion engine oils. Semi-crystalline OCP viscosity index improver has improved low-temperature fluidity, but its shear resistance and oxidation resistance are not good. If the dosage is too large, it will affect the high-temperature cleaning and dispersing properties of the oil

OCP is subject to high-temperature oxidation during use, and polymer aggregation, decomposition, oxidation, etc. will cause a series of problems such as increased oil viscosity, increased acid value, decreased cleaning and dispersibility, and increased carbon deposits, which will ultimately affect the service life of the oil.

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