COOLTHERM EP-3500
Harmonization Code : 3910.00.00.90 | Silicones in Primary Forms; Others
Main features
- 3.3 W/(m K) Thermal Conductivity
- 10.4 to 12 ppm/deg C CTE
- 205 to 206 deg C Glass Transition
Product Description
CoolTherm® EP-3500 Epoxy Resin is a dark gray, highly filled epoxy resin formulated for use with CoolTherm® EP-3500 Hardener or CoolTherm® EP-2000 Hardener. The two-component systems are designed for encapsulating motor stators, transformer coils, and electrical devices requiring a rigid material with high thermal conductivity and a low coefficient of linear thermal expansion. Depending on the selected hardener, the cured system provides a typical thermal conductivity of 2.6 or 3.3 W/m·K, a glass transition temperature of approximately 205–206 °C by TMA, and electrical insulation properties.
Key features
- High thermal conductivity: Provides a typical cured thermal conductivity of 3.3 W/m·K with EP-3500 Hardener or 2.6 W/m·K with EP-2000 Hardener.
- Low thermal expansion: Delivers a typical coefficient of linear thermal expansion of 10.4–12 ppm/°C, depending on the selected hardener.
- High-temperature cured system: Provides a typical glass transition temperature of 205–206 °C by TMA.
Applications / Suitable for
- Motor stator encapsulation
- Transformer-coil encapsulation
- Electrical devices requiring rigid, thermally conductive encapsulation with low thermal expansion
TDS, SDS & Technical Documents
Technical Specifications
General Properties
Physical Properties
Thermal Properties
Electrical Properties
Additional Information
As-supplied / before-processing properties
Typical properties of CoolTherm EP-3500 resin and its mixed systems with CoolTherm EP-3500 or EP-2000 Hardener before cure. Values are not intended for specification purposes.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Appearance | Dark gray paste | — | CoolTherm EP-3500 resin as supplied |
| Viscosity | 9,200 | cP | Resin at 60 °C; shear rate 10/sec |
| Specific gravity | 2.98 | — | Resin at 25 °C |
| Mix ratio by weight | 100:100 / 100:72 | Resin:hardener | EP-3500 Hardener / EP-2000 Hardener |
| Mix ratio by volume | 100:100 / 100:78 | Resin:hardener | EP-3500 Hardener / EP-2000 Hardener |
| Mixed viscosity | 8,000 / 3,800 | cP | At 60 °C; EP-3500 Hardener / EP-2000 Hardener |
| Mixed specific gravity | 2.98 / 2.88 | — | EP-3500 Hardener / EP-2000 Hardener |
| Working life | >3 / >3 | hours | At 60 °C; EP-3500 Hardener / EP-2000 Hardener |
| Shelf life | 9 | months | Resin stored at 25 °C in the original, unopened container; periodic container rotation is required to reduce hard-packed filler settling |
After-processing / final-state properties
Typical cured properties of CoolTherm EP-3500 resin with EP-3500 or EP-2000 Hardener. Values are listed in that order and were measured after curing for 2 hours each at 120 °C, 150 °C, 180 °C, and 210 °C. Values are not intended for specification purposes.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Thermal conductivity | 3.3 / 2.6 | W/m·K | EP-3500 Hardener / EP-2000 Hardener; test method not stated |
| Coefficient of linear thermal expansion | 10.4 / 12 | ppm/°C | EP-3500 Hardener / EP-2000 Hardener; test method and temperature region not stated |
| Glass transition temperature | 206 / 205 | °C | TMA; EP-3500 Hardener / EP-2000 Hardener |
| Hardness | 90 / 93 | Shore D | ASTM D2240; EP-3500 Hardener / EP-2000 Hardener |
| Storage modulus | 20 / — | GPa | DMA; EP-3500 Hardener / EP-2000 Hardener; EP-2000 Hardener value not reported |
| Volume resistivity | 1 × 1014 / 1 × 1014 | ohm-cm | ASTM D257 at 25 °C; EP-3500 Hardener / EP-2000 Hardener |
| Dielectric strength | 15.4 (390) / — | kV/mm (V/mil) | ASTM D149; EP-3500 Hardener / EP-2000 Hardener; EP-2000 Hardener value not reported |
