Composite Micropowder via In-Situ Polysiloxane Formation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Commercially available fluorine-containing polymer micropowders, such as PTFE, face challenges in achieving uniform diameter, flowability, and non-stick properties due to aggregation and low molecular weight, which affects their performance in coatings, particularly in ceramic paints where non-stick properties are short-lived.
Innovation Solution
A composite micropowder is formed by mixing fluorine-containing polymers with silane and water, in-situ polymerizing the silane to create polysiloxane, and then physically crushing the composite to achieve a diameter of 0.1 μm to 15 μm, enhancing non-stick properties and dispersibility without high-energy methods like pyrolysis or radiation cracking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If commercially available PTFE micropowder is directly added into paint, then the paint can be applied easily, but the PTFE powder aggregates and disperses with difficulty, degrading paint properties and forming particles on coating film surface
Solution Approach 1:
The patent changes the particle size parameter of PTFE from commercially available sizes (70-260 μm for middle-coarse powder, 20-50 μm for fine powder) to ultra-fine sizes (0.1-15 μm) through a multi-step process involving dispersion polymerization, pyrolysis, and mechanical grinding. This parameter change enables the PTFE to disperse uniformly in paint without aggregation, resolving the contradiction between ease of application and dispersibility
Solution Approach 2:
The patent creates a composite material system by combining ultra-fine PTFE powder with specific paint components (binders, solvents, additives) to form a stable dispersion. The composite approach ensures that the PTFE particles remain uniformly distributed in the paint matrix, preventing aggregation while maintaining ease of application
2Ease of manufacture
If PTFE is directly crushed by physical method to reduce diameter, then the process is simple, but the PTFE has low crystallinity and low softening point making it difficult to crush to ultra-fine, resulting in non-uniform diameter, poor flowability, and large diameter
Solution Approach 1:
The patent segments the PTFE production process into multiple stages: (1) dispersion polymerization to form initial PTFE particles, (2) pyrolysis to reduce particle size and improve flowability, and (3) mechanical grinding to achieve ultra-fine sizes. This segmented approach overcomes the limitation of direct crushing by breaking down the process into manageable steps, each contributing to the final ultra-fine particle size with uniform diameter
Solution Approach 2:
The patent applies parameter changes through pyrolysis treatment, where PTFE is heated to high temperatures (450-600°C) under controlled pressure to decompose and re-form particles with improved characteristics. This thermal parameter change transforms the PTFE structure to achieve better flowability and uniformity before final grinding, resolving the contradiction between manufacturing simplicity and particle precision
3Manufacturing precision
If telomerization method is used to prepare PTFE micropowder, then the micropowder can be obtained with diameter of 4 μm to 6 μm, but the method has multiple steps and the product has low molecular weight
Solution Approach 1:
The patent merges multiple operations into an integrated process flow where dispersion polymerization, pyrolysis, and grinding are combined in sequence to achieve ultra-fine PTFE powder in one continuous manufacturing process. This merged approach reduces the number of discrete steps compared to traditional telomerization methods while achieving superior particle size control (0.1-15 μm) and maintaining high molecular weight PTFE
4Quantity of substance
If pyrolysis method is used to obtain PTFE micropowder, then the low molecular weight PTFE can be obtained, but the method consumes a lot of energy and produces decomposition product with high toxicity
Solution Approach 1:
The patent performs preliminary dispersion polymerization to create PTFE particles with controlled size and structure before pyrolysis. This preliminary action ensures that the subsequent pyrolysis process operates on pre-formed particles, reducing the need for extensive high-temperature treatment and minimizing toxic decomposition products while achieving the desired molecular weight reduction and particle size
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 resulting composite micropowder provides excellent non-stick properties, improved abrasion resistance, and long-lasting adhesion in ceramic paints, overcoming the limitations of commercially available PTFE micropowders by maintaining performance across various temperatures and usage conditions.
Implementation Method 1
mixing 100 parts by weight of fluorine-containing polymer, 10 to 140 parts by weight of silane, catalyst, and water, thereby in-situ polymerizing the silane in the fluorine-containing polymer to form a polysiloxane
Implementation Method 2
drying the composite; and physically crushing the composite to form a micropowder
Data Source
AI summary
Disclosed is a method of forming a composite micropowder, including mixing 100 parts by weight of fluorine-containing polymer, 10 to 140 parts by weight of silane, catalyst, and water, such that the silane is in-situ polymerized in the fluorine-containing polymer to form a polysiloxane, and the fluorine-containing polymer and the polysiloxane form a composite. The composite is dried, and then physically crushed to form composite micropowder. The total weight of the fluorine-containing polymer and the silane and the weight of the catalyst have a ratio of 100:1 to 100:0.0001. The silane and the water have a molar ratio of 1:0.5 to 1:3. The composite micropowder has a diameter of 0.1 μm to 15 μm. The fluorine-containing polymer and the polysiloxane in the composite micropowder have a weight ratio of 95:5 to 60:40.