ISO-PUR® BD50-FR
Flame retardant in accordance with UL 94 V-0 (1,5 mm)
ISO-PUR® BD50-FR is a cold-curing 2-component polyurethane cast resin based on liquid synthetic rubber and polymeric aromatic diisocyanates. Due to its very high level of hydrophobicity the compound is ideally suited as moisture protection in telecommunication devices and for sealing and insulating various electronic components. Other possible applications include potting of antennas and sensors (control circuit boards) in various application fields (for example in the automotive industry). The casting compound has passed flame retardancy tests according to UL94 V-0 (1,5 mm) and is therefore particularly suitable for encapsulating electrical components tested according to UL standards. At low temperatures (Tg < -50°C), ISO- PUR® BD50-FR exerts little mechanical stress on sensitive electronic components and reliably protects these parts against environmental influences. The hydrolytic stability of the material is excellent. The cured material does not contain any phthalates and does not tend to become brittle. The material exhibits a high temperature stability compared to standard polybutadiene resins because of special additives are used to protect against thermo oxidative degradation. The cured material shows good adhesion to metal, ceramic and many plastics. ISO-PUR® BD50-FR is compliant according to EU Directives 2011/65/EU (“RoHS”) and 2015/863/EU (“RoHS III”).
Technical data
Resin
Colour
Viscosity (25°C; rot.; 1 s-1)
Viscosity (25°C; rot.; 10 s-1)
Density (23°C)
Black (other colours on request)
Approx. 11000 mPas
Approx. 7000 mPas
Approx. 1,60 g/cm³
Hardener
Colour
Viscosity (25°C; rot.; 1 s-1)
Viscosity (25°C; rot.; 10 s-1)
Density (23°C)
Brown
Approx. 130 mPas
Approx. 120 mPas
Approx. 1,23 g/cm³
Mixture
Mixing ratio resin : hardener
Colour
14,3 : 1 parts by weight
Black (other colours on request)
Density (23oC)
Approx. 1,57 g/cm³
Pot life (23°C)
Gel time (23°C)
Approx. 10 min
Approx. 30 min
Mixed viscosity (25°C; rot.; 1 s-1)
Mixed viscosity (25°C; rot.; 10 s-1)
Approx. 9200 mPas
Approx. 6300 mPas
Dielectric strength
> 7 kV/mm
Cured product
Mixing ratio resin : Hardener
Under standard curing condition
14,3 : 1 parts by weight
(14 days 23°C / 50% rel. h.) if not stated otherwise
Hardness Shore A
(23°C; 14d RT 50% rel. h.)
Hardness Shore A
(23°C; oven curing: 4hRT + 24h80°C)
Approx. 74
Approx. 76
Hardness Shore D
(23°C; 14d RT 50% rel. h.)
Hardness Shore D
(23°C; oven curing: 4hRT + 24h80°C)
Approx. 15
Approx. 17
Long-term temperature resistance
Short-term temperature resistance
Approx. 120°C
Approx. 140°C
Glass transition temperature (midset)
< -60°C
Tensile strength (5A specimen)
(2 mm thickness; speed: 10 mm/min; 23°C)
Elongation at break (5A specimen)
(2 mm thickness; speed: 10 mm/min; 23°C)
Approx. 1,30 N/mm2
Approx. 70%
Tear resistance
(W-specimen; incision; speed: 10 mm/min; 23°C)
Approx. 2,80 N/mm
Dielectric strength
> 20 kV/mm
Dielectric loss factor tan δ (25°C; 500 V AC; 50 Hz)
Approx. 0,09
Relative permittivity (25°C; 500 V AC; 50 Hz)
Approx. 6,20
Insulation resistance (25°C; 500 V DC)
Approx. 2,70×1010 Ohm
Volume resistance (25°C; 500 V DC)
Approx. 4,20×1012 Ohm×cm
Surface resistance (25°C; 500 V DC)
Approx. 2,30×1011 Ohm×cm
Thermal conductivity
Approx. 1,10 W/K×m
Water absorption
After 28 days in water (immersion, 23°C)
Approx. 1,65%
Water vapour permeability
(75% rel.h.; 23°C; 1 mm thickness)
Approx. 2,50×10-6 g/(day×mm2)
Storage and transport
Store in a dry and airtight, closed container at 10 – 35°C. Can be stored for at least 12 months in original sealed containers under the above conditions. Short-term deviations during transport and storage are acceptable.
Cleaning
To ensure good adhesion of the cast resin the customer should individually test the suitability of the involved surfaces. Possible pre-treatments like cleaning, activation processes (plasma pro-cess) etc. should also be taken into account. The contact surfaces should be free of dirt such as dust, grease or water. For cleaning we recom-mend ISO-RC® Degreaser for wipe degreasing or ISO-RC® Flux-Off + ISO-RC® Spraywash for spray degreasing (available in 400 ml spray cans).
Processing
Stir up the resin container thoroughly before use to remove any possible sedimentation. Weigh the resin and hardener in the desired mixing ratio and mix for 1 – 3 minutes (depending on mixed quantity and processing time). Apply suitable mixing speed in order to ensure complete homogeneous mixing without introducing too many air bubbles into the reaction mass. The ideal processing temperature is 20 – 25°C. In general, curing is delayed at lower temperatures and accelerated at higher temperatures. When using a double chamber bag, empty the corners well and knead for 3 minutes. Before casting, a homogeneous mass, free of streaks, must be obtained. Then pour immediately and do not scrape the mixing vessel. Air bubbles in the reaction mass can be removed before the end of the potlife by evacuating the material or carefully fanning the surface with a hot air gun. Machine casting is also possible.
The EC safety data sheet provides information on safety-relevant product properties.
Hardener component (containing diisocyanate): As of August 24, 2023, appropriate training must be provided before industrial or commercial use.