RBC-3400 FR

UL Listed: Yes
, UL Listed

RBC-3400 FR is a low viscosity, UL listed epoxy for 94 V-O flame retardency. It is designed for applications where thermal conductivity, excellent electrical insulation, high heat distortion and superior thermal shock properties are required.  RBC-3400 FR can be cured at room temperature or elevated temperature to fit a variety of applications. It can be used as a heat sink for large castings or as an encapsulant for heat generating components.


Mixed Viscosity @ 25oC,cps: 6,600
Shelf Life, (closed Container @ 25oC): 12 Months


Color: Black/any
Specific Gravity @ 25oC: 1.48
Hardness, Shore D: 88
Linear Shrinkage, in./in.: 0.003
Moisture Absorption 24 hr. @25 oC, %: 0.23
Izod Impact Strength, ft. lbs./in. of notch: 0.27
Tensile Strength @ 25oC, psi: 8,375
Compressive Strength  @ 25oC, psi: 19,320


Thermal Conductivity, cal/sec/cm2/oC/cm X 10-4: 27.3
Thermal Stability, 1000 Hrs. @ 175oC, % Wt. Loss: 0.35
Coefficient of Thermal Expansion, in./in./oC X 10-6: 27
Heat Distortion Temperature, oC: 125
Operating Temperature Range, oC: -65 to 130


Volume Resistivity  @ 25oC, ohm-cm: 5×1016
Dielectric Strength, volts/mil: 480
Dielectric Constant @ 25oC, 100 KC: 5.7
Dissipation Factor @ 25oC, 100 KC: 0.018

The above properties are typical of a system cured with Hardener AB-312


AB-56: A fast, room temperature curing system with good chemical and thermal properties.

A-121: A resilient, low viscosity system with slightly longer pot life, that exhibits excellent resistance to thermal shock.

AB-312: Good resistance to heat, chemicals, thermal and mechanical shock, and good     electrical properties at high humidity.


Weigh the desired amount of RBC-3400 FR into a clean container and combine with recommended hardener in the proper ratio as shown below.

Hardener Parts by Weight
per 100 pts. Resin
Pot Life 
100 grams @ 25oC
AB-56 20 1 hour
A-121 12 3 hours
AB-312 13 2 hours


Hardener Cure @ 25oC Cure @ 65oC Cure @ 100oC Cure @ 130oC
AB-56 24 hours 1 hour
A-121 24 hours 3 hours 2 hours 1 hour
AB-312 3 hours 2 hours 1 hour