Polysiloxane Defoaming Agent for Lubricating Oil Centrifugal Stability
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Solution Overview
Problem
Polysiloxane defoaming agents used in lubricating oils tend to precipitate and lose effectiveness over time due to high centrifugal forces in machinery, leading to increased foaming and reduced lubrication performance.
Innovation Solution
A polymer-based defoaming agent with specific molecular weight and structural components, including repeating units from (meth)acryloyl groups and polysiloxane structures, is used in lubricating oil compositions to maintain defoaming performance under high centrifugal conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polysiloxane defoaming agents are used in lubricating oil, then defoaming performance is improved, but precipitation and concentration unevenness occur during long-term storage and use, leading to gradual loss of defoaming effect
Solution Approach 1:
The patent changes the molecular weight parameter of the polysiloxane defoaming agent from conventional high values (>1,000,000) to a specific range (100,000 to 1,000,000). This parameter modification improves the balance between defoaming performance and storage stability, preventing precipitation while maintaining effective defoaming action throughout the service life of the lubricating oil.
Solution Approach 2:
The patent employs a composite defoaming agent structure combining polysiloxane backbone with specific side chain modifications (introduction of aromatic hydrocarbon groups or fluorinated groups). This composite structure enhances both the defoaming efficacy and the compatibility with lubricating oil, preventing concentration unevenness and precipitation during storage and use.
2Reliability
If conventional polysiloxane defoaming agents are used, then initial defoaming effect is achieved, but centrifugal force in machinery causes separation and concentration in specific positions, decreasing defoaming agent concentration in circulating oil
Solution Approach 1:
The patent optimizes the molecular weight parameter to 100,000 to 1,000,000, which provides sufficient viscosity to resist centrifugal separation while maintaining流动性 for effective defoaming. This parameter adjustment ensures the defoaming agent remains uniformly distributed in the lubricating oil even under high centrifugal forces in torque converters and CVT pulleys.
Solution Approach 2:
The patent introduces intermediate structural components (aromatic hydrocarbon groups or fluorinated groups) as mediators between the polysiloxane backbone and the lubricating oil matrix. These intermediate groups enhance compatibility and prevent phase separation under centrifugal force, ensuring uniform distribution and sustained defoaming performance throughout the oil circulation system.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The polymer-based defoaming agent effectively suppresses foaming and maintains lubrication performance for a long duration, even under high centrifugal forces, preventing precipitation and ensuring consistent oil quality.
Implementation Method 1
a polymer as a defoaming agent... having a weight average molecular weight of 100,000 to 1,000,000, the polymer comprising: a repeating unit represented by the following general formula (1)... and a repeating unit represented by the following general formula (3)
Implementation Method 2
large specific gravity of polysiloxne defoaming agents (silicone defoaming agents) makes it easy to cause precipitation and unevenness in concentration during long-term storage in bottles or long-term use in machinery... When lubricating oil is supplied to such a position, a silicone defoaming agent compound is separated by such centrifugal effect
Data Source
Figure 1
AI summary
A defoaming agent including a polymer, the polymer including: a repeating unit represented by the following general formula (1); and a repeating unit represented by the following general formula (3): wherein in the general formula (1), X1 is a repeating unit obtainable by polymerization of a first ethylenic unsaturated group; Y1 is a side chain including a linear or branched polysiloxane structure, the polysiloxane structure having a polymerization degree of 5 to 300; and Z1 is a linking group linking the repeating unit X1 and the side chain Y1; wherein in the general formula (3), X2 is a repeating unit obtainable by polymerization of a second ethylenic unsaturated group, Y2 is a C1-30 hydrocarbyl side chain; and Z2 is a linking group linking the repeating unit X2 and the side chain Y2.