Water-Based High-Temperature Silicone Resin Insulating Paint
For a long time, the preparation of high-temperature insulatation coating (Class H coil impregnation paint, heat-resistant up to 180℃) has relied on solvent-based organic silicon resin, with toluene or xylene as the usual solvents. According to data traditional high-temperature insulating paints not only increase VOC emissions, causing environmental pollution, but also pose potential health risks to operators.
SIOResin’s Water-based high-temperature silicone resin insulating paint meets the market demand for water-based ultra-high temperature insulating paints. This paint uses our water-based high-temperature pure silicone resin SiO-715 as the film-forming material, capable of withstanding temperatures from 200℃ to 800℃. Applied through dipping or brushing on various metal substrates, the baked coating provides insulation, high-temperature resistance, high hardness, strong adhesion, and high toughness.
Product Characteristics
- Excellent water dilution, low odor, free of toluene and xylene, compliant with environmental regulations.
- Superior film-forming ability, good wetting and leveling properties, and fast surface drying at room temperature.
- Good adhesion to metals such as copper, aluminum, and iron.
- Exceptional hardness, achieving up to 8-9H depending on the substrate and curing temperature.
- Fully cured film exhibits excellent thermal stability, outstanding weather resistance, and salt spray resistance.
- The fully cured paint film has good toughness, abrasion resistance, impact resistance, anti-yellowing, and chemical resistance.
- High-temperature endurance; the coating itself can withstand extreme temperatures up to 1000℃. On metal substrates, it can endure up to 800℃ with minimal color change after prolonged high-temperature exposure.
- Excellent insulation performance, capable of withstanding 6000V voltage.
Technical Indicators
| Item | Test Method | Index |
| Coating Appearance | Beaker sampling, visual | Grey, black liquid (settles over time, stir to homogenize) |
| Baked Coating Appearance | Visual, color chart | Uniform color, no base exposure, no cracking, no wrinkling or bubbling, no discoloration |
| Solid Content (w/w) | 2h@150℃ | 40-45 |
| Viscosity | (Tu-4 cup) @25℃, s | 30-100 |
| Drying Time | Surface dry: (23±2℃) | ≤1h |
| Fully dry: 220℃ baking | 30 minutes | |
| Adhesion (sandblasted workpiece) | Cross-cut test | Grade 0 |
| Heat Resistance | 6h@600℃ | Intact coating, no cracking or peeling |
| Thermal Shock Resistance | Heated at 550℃ for 1 hour, then quenched in cold water; >=5 cycles | No peeling, cracking, or bubbling, adhesion test grade 0; minor gloss and color changes allowed |
Product Applications
- Coil impregnation paint for temperatures from 200℃ to 800℃.
- Water-based insulating coatings for electronic, electrical components, and electromechanical products under high temperatures.
- Motor protection for high-power transformers, large generator sets, engines, nuclear power units, and wind power generators.
Suggested Formulation
For more about water-based high-temperature silicone resin insulating paint, please refer to the following recommended formulation. And it can be used as a starting point for preparing water-based one-component baking insulating paint:
Insulating Paste Formulation:
| Component | Parts by Weight | Function | Supplier |
| Deionized Water | 531.6 | ||
| Dispersant BYK-190 | 24 | BYK | |
| Anti-settling Agent BYK-420 (10%) | 18 | BYK | |
| Anti-settling Agent Bentone LT (2%) | 24 | Haimings | |
| Defoamer Foamex 810 | 2.4 | TEGO | |
| Low Melting Point Glass Powder (350℃) | 200 | Enhances high-temperature adhesion | |
| Mica Powder (insulating grade) | 200 | Enhances low-temperature adhesion, insulation | |
| High-purity Zinc Phosphate | 100 | Enhances boiling water resistance, salt spray resistance | |
| Copper Chromium Black | 100 | High-temperature pigment | |
| Total | 1200 |
Pigment and filler content = 50%
Process:
- Add defoamer, anti-settling agents, and dispersant to deionized water, stir at 1000rpm for 5 minutes.
- Add mica powder and low melting point glass powder, stir at 2000-3000rpm for 45 minutes.
High-Temperature Insulating Coating Formulation:
| Component | Parts by Weight |
| Silicone Resin Emulsion SiO-715 | 100 |
| Insulating Paste | 20-67 |
| Anti-settling Agent (Bentone LT, 2%) | 4 |
| Anti-flash Rust Agent | 1.0 |
| Epoxy Phosphate (adhesion promoter) | 1 |
| Wetting Agent (TEGO 4100) | 0.3 |
| Defoamer (TEGO Foamex 810) | 0.1 |
| Thickener (Dow DR-50) | 1-2 |
Process:
- Directly disperse all components until uniform, stir at 1000-1500r/min for 20-30 minutes, and adjust to suitable viscosity. Filter through a 200-mesh filter bag during packaging.
Note:
- Adjust solid content with deionized water as needed.
- Adjust pigment to binder ratio as needed. Higher pigment to binder ratio results in lower gloss and better heat resistance; lower ratio results in higher gloss, better salt spray resistance, and abrasion resistance. Use high pigment to binder ratio paint as primer and low ratio paint as topcoat for best results.
- Recommended dry film thickness for single spraying is 35-50 microns. Thicker films are prone to cracking. Ensure the previous coat is fully cured before re-coating.
- For initial use, gradually heat to a high-temperature environment to complete the secondary sintering of the paint film. Do not place unsintered workpieces directly into a high-temperature environment to avoid film cracking.
Usage Instructions
Application Methods:
Dipping or spraying.
Construction Process:
- Stirring: Stir the coating thoroughly before use, as it may settle over time. Dilute with 5-10% deionized water as needed to achieve the required spraying viscosity. It is recommended to test on a small scale first.
- Surface Preparation: Clean the substrate to remove oil and rust. For large-scale applications, enhance the substrate’s roughness through sandblasting, brushing, or grinding to improve adhesion.
- Application: Use dipping or spraying. Allow the coating to air dry at room temperature or bake below 80℃ to accelerate surface drying. Do not bake the wet film directly at high temperatures to avoid bubbling.
- Baking: Fully cure the coating at 200-280℃ for 10-60 minutes. Optimal curing conditions are 220℃ for 30 minutes or 280℃ for 10 minutes.
Attention:
- Thoroughly stir the coating before use to ensure homogeneity as it may settle due to the different densities of high-temperature resistant materials.
- Always tightly seal the container after use to prevent the coating from thickening and forming a skin.
- Clean spray guns and brushes promptly with water after use to prevent residue from drying and affecting future applications.
Any further questions? Simply contact our professional engineers for assistance.
Best luck!