Types of Silicone Oils with Strong Adhesion to Metal
Amino-modified silicone oil is currently the silicone oil type with the strongest known adhesion to metal, followed by epoxy-modified silicone oil and carboxyl-modified silicone oil.
Why does amino-modified silicone oil have the strongest adhesion?
Amino-modified silicone oil contains amino groups (-NH₂) in its molecular structure, which have strong polarity and reactivity:
- Amino groups can form a stable complex layer on the metal surface, significantly enhancing adhesion.
- They can form chemical bonds with oxides on the metal surface, with adhesion reaching over 3N/cm, much higher than ordinary silicone oil.
- It can maintain excellent adhesion even in high-temperature and humid environments.
Adhesion Comparison of Main Modified Silicone Oils
| Silicone Oil Type | Adhesion Performance | Action Mechanism | Application Scenarios |
|---|---|---|---|
| Amino-modified silicone oil | ★★★★★ Strongest | Amino groups form a stable complex layer with metal | Metal surface treatment, anti-corrosion coatings, electronic component protection |
| Epoxy-modified silicone oil | ★★★★ | Epoxy groups react with active groups on the metal surface | Coating additives, metal primers, adhesives |
| Carboxyl-modified silicone oil | ★★★★ | Carboxyl groups chelate with metal ions | Water-based coatings, metal anti-corrosion, adhesion promoters |
| Polyether-modified silicone oil | ★★★ | Polar ether bonds enhance wetting and adsorption | Lubricants, release agents, surfactants |
| Ordinary methyl silicone oil | ★★ | Only van der Waals force acts, weak adhesion (0.1-0.3N/cm) | General lubrication, short-term protection (requires adhesion promoters) |
Other High-Adhesion Options
- Fluorosilicone-modified silicone oil: Introduces fluorine elements on the basis of amino-modified silicone oil. It not only has strong adhesion (can reach Grade 1) but also excellent chemical resistance and heat resistance.
- Mercapto-modified silicone oil (e.g., SC-800): Contains mercapto groups (-SH), which have special affinity for metals. Suitable for special coatings and surface treatments.
- Long-chain alkyl silicone oil: Has good adsorption and lubricity for metals, especially suitable for light metals such as aluminum, magnesium, and zinc.
Application Recommendations
- Metal anti-corrosion protection: Choose amino-modified silicone oil or fluorosilicone-modified silicone oil to form a firm protective film and isolate corrosive media.
- Enhanced adhesion of metal coatings: Add epoxy-modified silicone oil (e.g., E701) or carboxyl silicone oil (e.g., LX2001) to coatings to improve the bonding force between the coating and metal.
- Metal lubrication and protection: Use high-viscosity amino-modified silicone oil, which has both excellent adhesion and lubricity to prevent wear and corrosion of metal surfaces.
Summary
If pursuing the strongest adhesion to metal, amino-modified silicone oil is the first choice. The amino groups in its molecules can form stable chemical bonds with the metal surface, and its adhesion is far superior to other types of silicone oil. Secondly, epoxy-modified or carboxyl-modified silicone oil can be considered, as they also significantly improve adhesion to metal.
Note: In practical applications, the adhesion of silicone oil is also affected by factors such as metal surface cleanliness, roughness, and temperature. It is recommended to select the appropriate type according to specific needs and conduct tests.
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