Silicone Oil Defoamer Composition for Alkaline Foam Stability
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Solution Overview
Problem
Existing silicone defoamers suffer from inadequate initial defoaming performance, particularly in alkaline foaming liquids, and degradation over time, especially under intense agitation conditions, with a lack of quantitative evaluation methods.
Innovation Solution
A method for evaluating defoaming performance using 29Si-CP/MAS-NMR to determine the ratio of silica surface silanol groups and triorganosiloxy to diorganosiloxy units in a silicone-based oil compound, ensuring a ratio of (Q2+Q3)/Q4 between 70/30 to 20/80 and (M/D) between 80/20 to 10/90, enhancing initial defoaming properties and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional oil compound defoamers are used, then defoaming performance is achieved, but initial defoaming performance is insufficient and defoaming performance degrades over time in alkaline foaming liquids
Solution Approach 1:
The patent changes the chemical parameters of the silica surface by controlling the ratio of silanol groups (Q2+Q3)/Q4 to be between 70/30 and 20/80, and the ratio of triorganosiloxy to diorganosiloxy units (M/D) to be between 80/20 and 10/90. This parameter optimization ensures both initial defoaming performance and long-term stability in alkaline conditions
Solution Approach 2:
The patent creates a composite oil compound system combining organopolysiloxane with specifically treated silica particles. The composite structure leverages the hydrophobic properties of the organopolysiloxane and the surface-treated silica to achieve synergistic defoaming performance that maintains stability over time
2Reliability
If silica is hydrophobized with chlorosilane or nitrogen-containing organosilicon compound, then some defoaming improvement is achieved, but defoaming performance still lowers with time under severe conditions
Solution Approach 1:
The patent optimizes the surface treatment parameters by controlling the (Q2+Q3)/Q4 ratio and M/D ratio within specific ranges, which provides superior resistance to degradation under severe conditions compared to conventional hydrophobization methods
Solution Approach 2:
The patent replaces conventional mechanical mixing and empirical formulation approaches with a quantitative NMR-based evaluation method that provides precise control and measurement of silica surface characteristics, enabling systematic optimization of defoaming performance
3Measurement precision
If quantitative evaluation method is implemented, then defoamer selection is improved, but measurement complexity increases
Solution Approach 1:
The patent replaces complex empirical evaluation procedures with a standardized 29Si-CP/MAS-NMR measurement method that provides quantitative data on silica surface characteristics. This substitution of measurement approach enables objective, reproducible evaluation while maintaining manageable operational complexity through established NMR protocols
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 method provides a quantitative evaluation for selecting defoamers with excellent initial and long-term defoaming performance, even in alkaline conditions, and under intense agitation.
Implementation Method 1
29Si-CP/MAS-NMR
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
An oil compound used for defoaming includes (A) a substantially hydrophobic organopolysiloxane having a viscosity of 10 to 100,000 mm2/second at 25°C, and (B) finely divided silica that has undergone surface hydrophobization treatment, wherein when an insoluble matter is collected from the oil compound by using hexane and the spectra of the insoluble matter are measured by 29Si-CP/MAS-NMR, the peaks of the silica due to the SiO4/2 (Q) units on the silica surface are such that a ratio [(Q2+Q3)/Q4] between a total area (Q2+Q3) wherein Q2 is a peak area of a silicon atom having two unreacted silanol groups and Q3 is a peak area of a silicon atom having one unreacted silanol group and an area Q4 wherein Q4 is a peak area of a silicon atom having no unreacted silanol group is at 70/30 to 20/80.