Ethylene Copolymer Viscosity Modifiers Preventing Flocculation

The patent applies parameter changes by precisely controlling the ethylene content within 60-85 wt% range and molecular weight within 50,000-150,000 g/mol, along with specifying melt flow rate and density parameters. This optimization resolves the contradiction by finding the optimal parameter range where sufficient thickening efficiency and shear stability are achieved while preventing flocculation and precipitation that occur at higher ethylene contents.

The patent uses composite materials by blending ethylene-alpha-olefin copolymer with ethylene-olefin-diene terpolymer in specific ratios (5-50% and 50-95% respectively). This composite approach allows the formulation to achieve high shear stability and thickening efficiency from the copolymer component while the terpolymer component prevents aggregation and flocculation, thus resolving the contradiction between improved reliability and prevention of harmful precipitation.

The patent optimizes multiple parameters simultaneously: ethylene content (60-85 wt%), molecular weight (50,000-150,000 g/mol), and melt flow rate (0.5-5 g/10 min). This multi-parameter optimization ensures that the polymer provides sufficient viscosity index improvement while maintaining good low temperature solution rheology by preventing flocculation that would otherwise occur at higher ethylene contents.

The blended composite of ethylene-alpha-olefin copolymer and ethylene-olefin-diene terpolymer resolves the temperature-related contradiction. The copolymer provides viscosity index improvement across the temperature range, while the terpolymer component ensures good low temperature solution rheology by preventing aggregation and gel formation, thus maintaining ease of operation at low temperatures.

The patent specifies precise parameter ranges: ethylene content of 60-85 wt% and molecular weight of 50,000-150,000 g/mol. These controlled parameters ensure that the polymer maintains adequate high temperature lubrication properties through sufficient viscosity, while preventing the excessive thickening and precipitate formation that would cause clogging of pumps and passageways.

The composite formulation blends ethylene-alpha-olefin copolymer (5-50%) with ethylene-olefin-diene terpolymer (50-95%). The copolymer provides the necessary high temperature lubrication through viscosity enhancement, while the terpolymer component acts as a dispersant that prevents aggregation and precipitate formation, thereby preventing clogging and maintaining reliability in the lubrication system.