ISO-CAST® A765-BKE
Flame retardant in accordance with UL 94 V-0 (6 mm)
ISO-CAST® A765-BKE
ISO-CAST® A765-BKE is a mineral-filled, cold-curing 2-component polyurethane casting resin based on polyether and ester polyols, epoxy resins as well as polymeric aromatic diisocyanates. The potting compound has passed fire protection tests according to UL 94V-0 (6 mm) and is therefore particularly suitable for potting electrical components that are tested according to the UL standard. ISO-CAST® A765-BKE does not contain any plasticisers that could migrate and therefore does not tend to become brittle. The product has a low potting viscosity, good thermal conductivity and little shrinkage during curing. The compound shows good corrosion protection properties and high adhesion to metal, ceramics and many plastics. The resistance to hydrolysis is excellent. The product 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)
Beige
Approx. 23000 mPas
Approx. 11000 mPas
Approx. 1,58 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
5 : 1 parts by weight
8 : 1 parts by weight
Beige (other colours on request)
Density (23°C)
5 : 1 parts by weight
8 : 1 parts by weight
Approx. 1,50 g/cm³
Approx. 1,50 g/cm³
Pot life (23°C) /
Gel time (23°C)
5 : 1 parts by weight
8 : 1 parts by weight
Approx. 40 min / approx. 120 min
Approx. 60 min / approx. 120 min
Mixed viscosity (25°C; rot.; 1 s-1)
5 : 1 parts by weight
8 : 1 parts by weight
Approx. 7500 mPas
Approx. 9300 mPas
Mixed viscosity (25°C; rot.; 10 s-1)
5 : 1 parts by weight
8 : 1 parts by weight
Approx. 4000 mPas
Approx. 5400 mPas
Dielectric strength
> 8 kV/mm
Cured product
Mixing ratio resin: hardener
Under standard curing condition
5 : 1 parts by weight
8 : 1 parts by weight
(14 days 23°C / 50% relative humidity) unless otherwise stated
Hardness Shore D
(23°C; 14d RT 50% rel. h.) /
Hardness Shore D
(23°C; oven curing: 4hRT + 24h80°C)
5 : 1 parts by weight
8 : 1 parts by weight
Approx. 58 / approx. 60
Approx. 42 / approx. 42
Long-term temperature resistance /
Short-term temperature resistance
5 : 1 parts by weight
8 : 1 parts by weight
Approx. 130°C / approx. 210°C
Approx. 130°C / approx. 210°C
Glass transition temperature (midset)
5 : 1 parts by weight
8 : 1 parts by weight
Approx. -10°C
Approx. -4°C
Tensile strength (5A specimen)
(2 mm thickness; speed: 10 mm/min; 23°C)
5 : 1 parts by weight
8 : 1 parts by weight
Approx. 20 N/mm2
Approx. 3,75 N/mm2
Elongation at break (5A specimen)
(2 mm thickness; speed: 10 mm/min; 23°C)
5 : 1 parts by weight
8 : 1 parts by weight
Approx. 17%
Approx. 44%
Tear resistance
(W-specimen; incision; speed: 10 mm/min; 23°C)
5 : 1 parts by weight
8 : 1 parts by weight
Approx. 57 N/mm
Approx. 8,10 N/mm
Dielectric strength
5 : 1 parts by weight
8 : 1 parts by weight
> 20 kV/mm
> 20 kV/mm
Dielectric loss factor tan δ (25°C; 50 Hz)
5 : 1 parts by weight
8 : 1 parts by weight
Approx. 0,02
Approx. 0,02
Dielectric constant ε (25°C; 50 Hz)
5 : 1 parts by weight
8 : 1 parts by weight
Approx. 4,30
Approx. 4,30
Thermal conductivity
5 : 1 parts by weight
8 : 1 parts by weight
Approx. 0,88 W/K×m
Approx. 0,88 W/K×m
Coefficient of thermal expansion
5 : 1 parts by weight
8 : 1 parts by weight
Approx. 150×10-6 K-1
Approx. 150×10-6 K-1
Tracking resistance
5 : 1 parts by weight
8 : 1 parts by weight
KA 3c
KA 3c
Water absorption
After 28 days in water (immersion; 23°C)
5 : 1 parts by weight
8 : 1 parts by weight
Approx. 0,30%
Approx. 0,93%
Water vapour permeability
(75% relative humidity; 23°C; 1 mm thickness)
5 : 1 parts by weight
8 : 1 parts by weight
Approx. 3,20×10-7 g/(day×mm2)
Approx. 7,80×10-7 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 thoroughly and knead for 3 minutes. Before casting, a homogeneous mass, free of streaks, must be obtained. Pour immediately afterwards and do not scrape the mixing vessel. Air bubbles that have been stirred in, 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.