Viscosity Index Improver Composition for Engine Oil
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current viscosity index improvers fail to effectively reduce high temperature high shear (HTHS) viscosity at 100°C in engine oils while maintaining low temperature viscosity and shear stability, leading to issues like oil leakage and seizure.
Innovation Solution
A viscosity index improver composition comprising a copolymer with a polyolefin-based monomer and a (meth)acrylic acid alkyl ester, specifically formulated to achieve a weight average molecular weight ratio and weight ratio that balances HTHS viscosity, shear stability, and low temperature performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If viscosity index improvers are added to reduce HTHS viscosity at 100°C, then fuel consumption is reduced, but low temperature viscosity increases causing oil leakage and seizure
Solution Approach 1:
The patent changes the molecular weight parameters of the viscosity index improver by specifying a weight average molecular weight of 100,000 to 1,200,000 and a polyolefin-based monomer content of 5% to 40%. This parameter optimization allows the additive to effectively reduce HTHS viscosity while maintaining adequate low temperature viscosity performance
Solution Approach 2:
The patent uses a composite viscosity index improver composition containing both polyolefin-based monomers (providing shear stability) and (meth)acrylic acid alkyl esters (providing viscosity index improvement). This composite approach enables simultaneous achievement of low HTHS viscosity and acceptable low temperature viscosity
2Stability of the object's composition
If viscosity index improvers are added to improve viscosity characteristics, then viscosity index increases, but shear stability deteriorates causing viscosity reduction during use
Solution Approach 1:
The patent optimizes the molecular weight range (100,000 to 1,200,000) and polyolefin-based monomer content (5% to 40%) of the viscosity index improver to achieve the right balance between viscosity index improvement and shear stability. This parameter tuning prevents excessive viscosity reduction during shear stress
Solution Approach 2:
The patent employs a composite additive system combining polyolefin-based monomers (for shear stability) and (meth)acrylic acid alkyl esters (for viscosity index improvement). The specific composition ratios ensure both viscosity index enhancement and maintenance of shear stability
3Temperature
If viscosity index improvers are added to lower HTHS viscosity, then effective temperature viscosity decreases, but low temperature viscosity increases causing engine seizure
Solution Approach 1:
The patent specifies precise parameter ranges including weight average molecular weight (100,000 to 1,200,000), polyolefin-based monomer content (5% to 40%), and (meth)acrylic acid alkyl ester composition. These parameter optimizations enable the viscosity index improver to lower HTHS viscosity while maintaining low temperature fluidity for proper engine startability
Solution Approach 2:
The patent uses a composite viscosity index improver formulation combining polyolefin-based monomers and (meth)acrylic acid alkyl esters with specific molecular weights and compositions. This composite structure provides the dual functionality of reducing high temperature viscosity while preserving low temperature performance
Data Source
AI summary
The present invention aims to provide a viscosity index improver composition and a lubricating oil composition having a low HTHS viscosity at 100°C, an excellent shear stability, and an excellent low temperature viscosity. The present invention relates to, for example, a viscosity index improver composition (C), containing: a copolymer (A) containing a polyolefin-based monomer (a) represented by the following formula (1) as a constituent monomer; a copolymer (B) containing a (meth)acrylic acid alkyl ester (c) having a C12-C15 straight-chain or branched alkyl group and a (meth)acrylic acid alkyl ester (d) having a C16-C20 straight-chain or branched alkyl group as constituent monomers; and a base oil, wherein a weight average molecular weight ratio {(A)/(B)} of the copolymer (A) to the copolymer (B) is 2 to 55, and a weight ratio (A/B) of the copolymer (A) to the copolymer (B) constituting the viscosity index improver composition (C) is 5 to 100: