Hydrophobized Silica Defoamer Active for Rapid Continuous Processing

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Solution Overview

Problem

Existing methods for rendering silica particles hydrophobic, such as the 'in-situ' and 'dry roast' processes, are inefficient and costly due to long reaction times and batch processing, leading to contamination and production inefficiencies.

Innovation Solution

Silica particles with high surface pH and low surface area are treated with silanol terminated PDMS using high energy milling, allowing for rapid bonding and minimal free silicone oil, enabling a continuous process with improved hydrophobicity and reduced carbon content.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional in-situ or dry roast methods are used to bond silicone oil to silica particles, then hydrophobicity is achieved, but reaction time is excessively long and process efficiency is poor

Engineering Contradiction:

ImprovehydrophobicityVSAvoidreaction time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent changes the surface pH parameter of silica particles to a high alkaline range (pH 11-13) before bonding. This parameter change creates highly reactive silanol groups on the silica surface, which dramatically accelerates the bonding reaction with silane-modified PDMS, reducing reaction time from hours to minutes while maintaining effective hydrophobicity

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent performs preliminary surface treatment of silica particles by adjusting surface pH to high alkaline conditions and introducing silane groups before the actual bonding step. This preliminary action prepares the silica surface with highly reactive groups, enabling rapid and efficient bonding in the subsequent step with minimal reaction time

Inventive Principle:

Principle #10Preliminary action

2Productivity

If low molecular weight silicone oil is used as hydrophobic agent, then bonding efficiency improves, but free silicone oil spreads uncontrollably causing contamination

Engineering Contradiction:

Improvebonding efficiencyVSAvoidcontamination

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent uses silane-modified polydimethylsiloxane (silane-PDMS) instead of conventional PDMS. This composite material combines the low molecular weight advantages of PDMS for rapid bonding with silane groups that enable covalent bonding to silica and reduced free oil migration, thus achieving both high bonding efficiency and minimal contamination

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent converts the potential harm of low molecular weight silicone oil (uncontrolled spreading) into a benefit by modifying it with silane groups. The silane modification allows the low molecular weight PDMS to bond rapidly and covalently attach to silica particles, transforming the harmful free oil into a beneficial bonded hydrophobic coating

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Reliability

If batch processing is used for hydrophobization, then reaction completeness can be ensured, but production cycle time increases and cost rises

Engineering Contradiction:

Improvereaction completenessVSAvoidproduction cycle

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent enables continuous processing by using rapidly reacting components (high pH silica and silane-PDMS) that achieve complete bonding in minutes. This allows continuous feeding of silica particles through the treatment process while maintaining reaction completeness, eliminating the batch processing cycle time and enabling high-volume production

Inventive Principle:

Principle #20Continuity of useful action

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 process significantly shortens reaction time, reduces silicone oil contamination, and enables efficient, cost-effective production of hydrophobized silica particles with excellent hydrophobicity, suitable for use in defoaming formulations.

Implementation Method 1

Silica particles having a high surface pH in combination with a low surface area unexpectedly provide enhanced reactivity to bond silanol terminated PDMS

Methodology Applied

Scientific EffectChemical bonding: Chemical Bonding

Implementation Method 2

The method may include high energy milling and/or bonding silica particles having a median particle size ranging from about 2 μm to about 50 μm with a hydrophobilizing agent in a high energy milling apparatus

Methodology Applied

Scientific EffectMechanical bonding: Mechanical Force

Data Source

PatentUS12427444B2Defoamer active, manufacturing thereof, and deforming formulation

Publication Date: 2025.09.30 WR GRACE & CO CONN

AI summary

This invention relates to a defoamer active. The defoamer active may include hydrophobized silica particles obtained by treating silica particles with a hydrophobilizing agent. The silica particles may have a BET surface of less than about 150 m2/g, a surface pH of at least about 10, and a median particle size ranging from about 2 μm to about 50 μm. The carbon content of the hydrophobized silica particles may not be more than 3%.