SynChem – Resins & Varnishes WEVOSIL 26040 FL
Solvent-free, two-component silicone-based gap filler with high thermal conductivity .
The resulting soft-elastic moulding material is characterized by good low-temperature flexibility and excellent behaviour in the temperature shock test. The system contains mineral fillers, which can be abrasive.
Recommended temperature range: -60 °C to +200 °C.
The resin is processed together with WEVOSIL 26040 FL B.
Application
- Pressure-sensitive electrical components
- Complete assemblies in SMD technology
- Thermally conductive adhesive and encapsulation
Standards
- Temperature application range -60 °C - +200 °C
Delivery forms
30 kg containers
Color
WEVOSIL 26040 FL A: Natural
WEVOSIL 26040 FL B: Blue
Storage
Polymer (A-component) and crosslinker (B-component) must be stored dry and at a temperature of 5 °C to 30 °C and not in the open air. The containers should be stored upright and not
directly on the cold floor (floor temperature not below 5 °C). WEVOSIL 26040 has a shelf life of 6 months after production.
At temperatures above 25 °C, the settling of the fillers contained in the casting compound is accelerated. The potting compound is then more difficult to homogenize.
Hardening
- Pot life: 50-70 minutes at room temperature, depending on layer thickness and casting volume.
- Curing time: 4 hours at room temperature, or 1 hour at 100 °C
- Final chemical curing: several days at room temperature
Curing notes:
- Excessive humidity has a damaging effect on the uncured compound. If necessary, curing should take place in an air-conditioned room, a container with low humidity or in an oven.
- Curing at an elevated temperature (50 - 100°C) accelerates the curing reaction and can influence the adhesion of the potting compound to the walls of the component.
- The WEVOSIL 26040 FL casting compound reaches its final hardness after a few days at room temperature.
- After approx. 4 hours curing at room temperature (or 1 h @ 100 °C) approx. 90 - 95 % of the curing takes place. To achieve the final hardness, post-curing can then be carried out for 2 hours at 165 - 180 °C. However, this last step is not absolutely necessary. After a few days, the casting compound reaches its final hardness even at room temperature (depending on the system).
- Electrical tests of the component quality can usually be carried out after the first curing (4 hours at room temperature or 1 h @ 100 °C).
Protection
Our products are intended exclusively for industrial use. For further details, please read the safety data sheet.
Processing
Our processing instructions please find here.
You have questions according to our resins and varnishes or want to send an inquiry?
Our product manager will be happy to help you.
Technical data
| Property | Unit of measure | Condition | Value | Test method |
|---|---|---|---|---|
| Mixing ratio | weight-% | 100:100 | ||
| Pot lilfe | min | 25 °C | 50-70 | |
| Curing time | h | 25 °C | 4 | |
| Curing time | h | 100 °C | 1 |
| Property | Unit of measure | Condition | Value | Test method |
|---|---|---|---|---|
| Density | g/cm³ | WEVOSIL 26040 FL A | 3.08-3.12 | |
| Density | g/cm³ | WEVOSIL 26040 FL B | 3.08-3.12 | |
| Viscosity | mPas | WEVOSIL 26040 FL B / 22 °C | 100,000-150,000 | |
| Viscosity | mPas | 22 °C, WEVOSIL 26040 FL A | 100,000-150,000 | |
| Mixture viscosity | 22 °C | 100,000-150,000 | ||
| Hardness | Shore 00 | 60-80 | ISO 48-4 | |
| Water absorption | % | 30 d, RT | 0.1 | |
| Elongation at break | % | 30 | ISO 527-2 |
| Property | Unit of measure | Condition | Value | Test method |
|---|---|---|---|---|
| Glass transition temperature | °C | -100 | TMA | |
| Thermal conductivity | W/m*K | 4.0 | ISO 22007-2:2008 |
| Property | Unit of measure | Condition | Value | Test method |
|---|---|---|---|---|
| Dielectric strength | kV/mm | >20 | DIN EN 60243 | |
| Dielectric constant ε at 50 Hz, 23 °C | 7.0 | DIN EN 60250 | ||
| Dielectric constant; at 1 kHz, 23 °C | 6.78 | DIN EN 60250 | ||
| Dielectric constant ε at 1 MHz, 23 °C | 6.51 | DIN EN 60250 | ||
| Volume resistance specific at 23 °C, 50 % r.h. | Ωxcm | >10^13 | DIN EN 62631-3-1:2016 | |
| Surface resistivity at 23°C and 50 % r.h. | Ω | >10^14 | DIN EN 62631-3-2:2016 |