CONATHANE EN-21
Harmonization Code : 3910.00.00.90 | Silicones in Primary Forms; Others

Main features
- Low-viscosity
- Room-temperature cure
- Good electrical and thermal properties
Product Description
CONATHANE® EN-21 Polyurethane Encapsulant is a two-component, unfilled, low-viscosity polyurethane potting compound for electronic circuits, components, and power devices. The system supports hand-mix, meter-mix, and vacuum potting or casting processes and may cure at room temperature or with low-temperature heat. Documented applications include transformers, coils, reed and mercury switches, inductors, ignition systems, voltage regulators, ballasts, microcircuits, rectifiers, and printed circuit assemblies. Typical cured properties include Shore A 80 hardness, 155% elongation, 0.3 W/m·K thermal conductivity, moisture resistance, and thermal-shock performance.
Key features
- Low-viscosity processing: Typical initial mixed viscosity is 2,000 cP at 25°C.
- Room-temperature or heat cure: Recommended cure options are seven days at 25°C or four hours at 80°C.
- Electrical and thermal properties: Typical data include 650 V/mil dielectric strength and 0.3 W/m·K thermal conductivity.
Applications / Suitable for
- Transformers, coils, switches, and inductors
- Voltage regulators, ballasts, and rectifiers
- Microcircuits and printed circuit assemblies
TDS, SDS & Technical Documents
Technical Specifications
General Properties
Additional Information
As-supplied / before-processing properties
Typical as-supplied or mixed-state values unless otherwise stated. These values are not sales specifications.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Part A viscosity | 6,000 | cP | At 25°C |
| Part B viscosity | 800 | cP | At 25°C |
| Part A specific gravity | 1.14 | N/A | At 25°C |
| Part B specific gravity | 0.96 | N/A | At 25°C |
| Mix ratio | 100:116 | parts by weight | Part A : Part B |
| Initial mixed viscosity | 2,000 | cP | At 25°C |
| Pot life | 40 | min | At 25°C |
| Cure options | 7 days at 25°C; 4 h at 80°C | N/A | Recommended schedules |
After-processing / final-state properties
Typical final-state values under the stated system and test conditions. These values are not sales specifications.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Hardness | 80 | Shore A | ASTM D2240 at 25°C |
| Tensile strength | 2,000 | psi | ASTM D412 at 25°C |
| Ultimate elongation | 155 | % | ASTM D412 at 25°C |
| Tear strength | 120 | pli | ASTM D624 at 25°C |
| Dielectric strength | 650 | V/mil | ASTM D149, 1/16 in specimen |
| Volume resistivity | 7.2 × 10¹⁴ | ohm·cm | ASTM D257 at 25°C |
| Thermal conductivity | 0.3 | W/m·K | ASTM C177 at 25°C |
| Coefficient of thermal expansion | 210 | ppm/°C | ASTM D696 at 25°C |





















