Best moisture protection with the new Bectron® MR melting resins

ELANTAS Europe has successfully marketed the Bectron® MR 3402, Bectron® MR 3404 and Bectron® MR 3406 melting resin product series for many years. These products continue to gain in popularity for the protection of electronic components. Bectron® MR 34xx products are solvent-free, single-component thermoplastics, distinguished by their excellent moisture resistance (including saline and chlorinated water applications). They can be applied as thick film coating as well as potting compound. The currently available products are heated to about 185 °C, liquefy and can then be applied to the PCB. The material solidifies on cooling without the need for an additional hardening process.

Furthermore, the Bectron® MR product series possesses excellent dielectric properties, even for high-frequency applications. The material can be reversibly fused and therefore offers the possibility to replace components and repair PCBs (see Fig. 1).

Figure 1: Selective removal of Bectron® MR 34xx for exchange of defective components underneath

All Bectron® MR variants are polyolefin-based. As with candle wax, these are flammable when sufficient excess in heat is available. However, numerous projects require flame-retarding properties. In close cooperation with our customers, our Sales as well as our Research & Development, the Bectron® MR product portfolio has now been extended to include Bectron® MR 3405 FR and Bectron® MR 3406 FR, so that ELANTAS Europe now offers materials with “UL 94 V-0“ certification.

Parallel to the development of the flame-retarding products, melting resins with other characteristic profiles than the existing Bectron® MR product series were developed. The lowest possible application temperature with maximum thermal stability and matched viscosity, hardness and adhesiveness represent in part contradictory requirements. The answer to this diverse application profile is a newly developed modular principle based on the different components of the Bectron® MR product series. This modular concept allows the application-specific adjustment of hardness, melting temperature and viscosity.

The table below gives an overview of the extended Bectron® MR portfolio together with their specific properties.

Bectron® MR 3404 H is a further development of our well-known Bectron® MR 3404. Thanks to its - for a thermoplastic polyolefin unusually - high hardness, it provides a high level of mechanical protection for electronic components.

The new Bectron® MR 3405 offers the greatest thermal stability. On the basis of this formulation and the newly acquired expertise of the modular principle, a harder Bectron® MR 3405 H and a flame-retarding Bectron® MR 3405 FR were also developed.

Application Conditions
ColorUL 94Max. Operation
HardnessSoftening Point
Bectron® MR 34029250 mPa·s @ 190°CYellow


125 °CShore A 15130 °C
Bectron® MR 34041100 mPa·s @ 180°CYellow-105 °CShore A 22107 °C
Bectron® MR 3404 H2000 mPa·s @ 170°CYellow-100 °CShore A 75105 °C
Bectron® MR 34052100 mPa·s @ 190°CYellow-145° CShore A 30155 °C
Bectron® MR 3405 H2000 mPa·s @ 190°CYellow-140 °CShore A 53153 °C
Bectron® MR 3405 FR2000 mPa·s @ 200°CBlackV-0145 °CShore A 35156 °C
Bectron® MR 3406520 mPa·s @ 180°CYellow-125°CShore A 15138 °C
Bectron® MR 3406 FR800 mPa·s @ 190°CBlackV-0125 °CShore A 16139 °C

Table: Overview of the extended Bectron® MR product series

Figure 2 illustrates the extension of the existing portfolio (green) to include the new more thermally stable and harder variants (yellow) and the UL 94 V-0 certified products (black).

Figure 2: Classification of Bectron® MR products as a function of material hardness and maximum temperature in operation

Fairs & Events