ISO-PUR® BD50-S
Very soft, low-viscosity PolyBD casting resin
ISO-PUR® BD50-S is a soft, 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, in 1kV cable boxes 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). Even at low temperatures (Tg < -50°C), ISO-PUR® BD50-S exerts practically no mechanical stress on sensitive electronic components and reliably protects these parts against environmental influences, because of its extremely low hardness. 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 an improved temperature stability better than standard polybutadienes re-sins, because of special additives used to protect against thermo oxidative degradation. The very low hardness of ISO-PUR® BD50-S allows the removal for maintenance or repair purposes. The material shows good adhesion to metal, ceramic and many plastics. ISO-PUR® BD50-S is RoHS 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
Approx. 700 mPas
Approx. 650 mPas
Approx. 0,93 g/cm³
Hardener
Colour
Viscosity (25°C; rot.; 1 s-1)
Viscosity (25°C; rot.; 10 s-1)
Density (23°C)
Yellow
Approx. 230 mPas
Approx. 220 mPas
Approx. 1,21 g/cm³
Mixture
Mixing ratio resin : hardener
Colour
10 : 1 parts by weight
Black (other colours on request)
Density (23oC)
Approx. 0,95 g/cm³
Pot life (23°C)
Gel time (23°C)
Approx. 100 min
Approx. 200 min
Mixing viscosity (25°C; rot.; 1 s-1)
Mixing viscosity (25°C; rot.; 10 s-1)
Approx. 830 mPas
Approx. 800 mPas
Dielelectric strength
> 7 kV/mm
Cured product
Mixing ratio resin : Hardener
under standard curing condition
10 : 1 parts by weight
(14 days 23°C / 50% rel. h.) if not stated otherwise
Hardness Shore 00
(23°C; 14d RT 50% rel. h.)
Hardness Shore 00
(23°C; oven curing: 4hRT + 24h80°C)
Approx. 25
Approx. 15
Long-term temperature resistance
Short-term temperature resistance
Approx. 100°C
Approx. 120°C
Glas transition temperature (midset)
< -55°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. 0,15 N/mm2
Approx. 440%
Tear resinstance
(W-specimen; incision; speed: 10 mm/min; 23°C)
Approx. 0,35 N/mm
Thermal conductivity
Approx. 0,20 W/K×m
Water absorption after 28 days
in water (immersion, 23°C)
Approx. 1,18%
Water vapour permeability
(75% rel.h.; 23°C; 1 mm thickness)
Approx. 7,80×10-6 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 process) etc. should also be taken into account. The contact surfaces should be free of dirt such as dust, grease or water. For cleaning we recommend 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.