COOLTHERM ES-40
Harmonization Code : 3910.00.00.90 | Silicones in Primary Forms; Others
Main features
- Eight Configurable Hardener Options
- Adhesive, Laminating, and Electrical-Insulation Uses
- Up to 77.2 MPa Tensile Strength
Product Description
Thermoset® ES-40 Epoxy System is a white, unfilled, general-purpose epoxy resin platform used with Thermoset® Hardeners No. 18, 25, 37, 65, 66, 67, 70, or 71. Hardener selection changes the mixed ratio, working life, cure schedule, rigidity, flexibility, heat resistance, moisture response, appearance, and cured electrical and mechanical properties. The resin has a typical 14,000 cP viscosity at 25°C and 1.18 specific gravity. Supported systems provide working lives from 5 to 75 minutes for a 200 g mass and room-temperature or elevated-temperature cure. Typical cured hardness ranges from 60 to 92 Shore D, tensile strength from 15.9 to 77.2 MPa, and elongation at break from 3.5% to 55%, depending on the selected hardener and ratio.
Key features
- Eight supported hardener options for different processing and cured-property requirements
- General-purpose resin for adhesive, laminating, and electrical or electronic insulation applications
- Room-temperature and elevated-temperature cure options
- Typical cured hardness from 60 to 92 Shore D
- Typical tensile strength from 15.9 to 77.2 MPa
- Adjustable rigid-to-flexible behaviour with selected hardeners and documented variable mix ratios
- Six-month resin shelf life at 25°C in the original unopened container
Applications
- Electrical and electronic insulation, potting, and encapsulation
- General-purpose adhesive bonding
- Laminating and cast parts requiring hardener-selectable rigidity or flexibility
TDS, SDS & Technical Documents
Technical Specifications
General Properties
Physical Properties
Additional Information
Thermoset® ES-40 Epoxy System
A white, unfilled epoxy resin formulated for use with eight Thermoset® hardeners. The selected hardener controls handling, cure, rigidity, flexibility, appearance, heat resistance, environmental response, and final electrical and mechanical properties for adhesive, laminating, and electrical or electronic insulation applications.
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ES-40 resin properties
ES-40 is supplied as a white unfilled liquid resin. Mixed-system properties depend on the hardener and ratio selected.
| Property | Typical value | Context |
|---|---|---|
| Appearance | White liquid | Unfilled epoxy resin. |
| Viscosity at 25°C | 14,000 cP | Resin-only value; mixed viscosity is hardener-dependent. |
| Specific gravity | 1.18 | Typical as-supplied resin value. |
Select the hardener for the required process and final material
The hardeners are separate formulations. Mix ratios, working lives, cure schedules, compliance language, and final properties must remain tied to the selected system.
| Field | No. 18 | No. 25 | No. 37 | No. 65 | No. 66 | No. 67 | No. 70 | No. 71 |
|---|---|---|---|---|---|---|---|---|
| Primary positioning | Heat-resistant room-temperature system | Fast room-temperature cure; high-gloss finish | Variable flexibility; conditional food-contact formulation | Low-viscosity, high-gloss encapsulation | Low-stress, variable rigidity | Elevated-temperature cure; up to 155°C continuous operation | Low-viscosity, impact and thermal-shock resistance | Low-exotherm, semi-rigid flexible system |
| Mix ratio by weight | 100:14 | 100:100 | 100:100* | 100:40 | 100:50* | 100:24 | 100:30 | 100:100 |
| Mix ratio by volume | 100:16 | 100:122 | 100:120 | 100:50 | 100:60* | 100:30 | 100:35 | 100:120 |
| Working life, 200 g at 25°C | 20 min | 5 min | 75 min | 50 min | 60 min | 60 min | 30 min | 60 min |
| Cure schedule | 24 h at 25°C | 24 h at 25°C | 24 h at 25°C; 2 h at 66°C; or 0.05 h at 93°C | 24 h at 25°C | 24 h at 25°C | 2 h at 100°C; optional 2 h at 150°C | 24 h at 25°C | 24 h at 25°C |
*Hardener No. 37 and No. 66 ratios may be varied to change bond rigidity. Food-contact compliance for No. 37 requires exactly 100 parts resin to 54 parts hardener by weight and compliance with all stated proportioning, mixing, application, and cure conditions.
Meter the selected hardener, minimise air, dispense, and follow its cure schedule
Transfer the required quantity of ES-40 resin to a clean container and add the selected hardener at its documented ratio. Mix thoroughly until uniform. Automatic meter/mix/dispense equipment may be used for higher-volume production.
- Minimise entrapped air during mixing.
- For high-voltage or other critical electrical applications, vacuum processing may be appropriate to reduce bubbles and voids.
- Apply using validated automatic meter/mix/dispense equipment.
- Follow only the cure schedule for the selected hardener.
- Start cure timing after the material reaches the stated temperature and account for oven ramp and part thermal mass.
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Storage and handling
ES-40 resin has a six-month shelf life when stored at 25°C in its original unopened container. If crystals form after cool storage or shipment, gently warm the resin to 50–60°C until the crystals melt before adding hardener. Use disposable mixing equipment where practical; solvent-cleaned equipment must be fully dry before reuse. Review the current resin and selected-hardener SDS and labels before handling.
Hardener-specific mechanical and electrical properties
The typical properties below apply only to the stated ES-40/hardener formulation and test condition. Variable-ratio systems can produce different results.
| Property | No. 18 | No. 25 | No. 37 | No. 65 | No. 66 | No. 67 | No. 70 | No. 71 |
|---|---|---|---|---|---|---|---|---|
| Hardness, Shore D | 88 | 80 | 84 | 85 | 85 | 92 | 82 | 60 |
| Tensile strength, MPa | 77.2 | 56.5 | 51.7 | 62.1 | 52.4 | 75.2 | 59.6 | 15.9 |
| Elongation at break, % | 3.6 | 5 | 4.5 | 4.5 | 12 | 5.2 | 3.5 | 55 |
| Moisture absorption, 24 h at 25°C, % | 0.18 | 0.23 | 0.55 | 0.22 | 0.35 | 0.20 | 0.36 | 0.85 |
| Volume resistivity at 25°C, ohm-cm | 4 × 1016 | 2.4 × 1014 | 1 × 1016 | 1 × 1015 | 1 × 1016 | 1 × 1016 | 2 × 1016 | 1 × 1014 |
| Dielectric constant, 1 MHz at 25°C | 3.8 | 3.4 | 3.7 | 4.2 | 3.7 | 4.4 | 3.4 | 4.2 |
| Dissipation factor, 1 MHz at 25°C | 0.020 | 0.028 | 0.016 | 0.016 | 0.016 | 0.038 | 0.025 | 0.021 |
Adhesive, laminating, and electrical-insulation uses
ES-40 is directly positioned for adhesive, laminating, and electrical or electronic insulation. Application selection must include the exact hardener, ratio, cure schedule, desired rigidity, voltage, geometry, humidity, operating temperature, and substrate.
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Potting & Encapsulation Materials Catalogue — PC3002
The catalogue provides portfolio-level comparison and lists the ES-40/70 system as a white, unfilled, moderate-viscosity two-component epoxy with 550 cP mixed viscosity, a 100:30 weight ratio, 24-hour room-temperature cure, and 82 Shore D hardness.
The current ES-40 technical datasheet governs the complete eight-hardener platform. Use catalogue values only for the identified ES-40/70 combination.
Select the ES-40 hardener for your process and final property requirements
Krayden can help review hardener selection, mix-ratio control, working life, vacuum processing, dispensing, cure schedule, rigidity, flexibility, heat resistance, electrical properties, moisture exposure, and application qualification for Thermoset® ES-40.
