ISO-CAST® A765-BF
• flame retardant acc. to UL94 V-0
• especially good ventilation
ISO-CAST® A765-BF is a mineral-filled, cold-curing, two-component polyurethane casting resin based on polyether and ester polyols, epoxy resins, and polymeric aromatic diisocyanates The casting compound has passed flame retardancy tests according to UL94 V-0 (6 mm) and is therefore particularly suitable for casting electrical components tested according to UL standards. The cured material of ISO-CAST® A765-BF does not contain any plasticisers and does not tend to become brittle. The system is characterised by low potting viscosity, good heat dissipation, and very little shrinkage during curing. The compound offers good corrosion protection and high adhesion to metal, ceramics, and many plastics. The hydrolysis resistance is excellent. ISO-CAST® A765-BF is compliant according to EU Directives 2011/65/EU (“RoHS”) and 2015/863/EU (“RoHS III”).
Technical data
Downloads
Resin
Colour
Viscosity (25 °C; rot.; 1 s-1)
Viscosity (25 °C; rot.; 10 s-1)
Density (23 °C)
Blue (other colours on request)
Approx. 20,000 mPas
Approx. 10,000 mPas
Approx. 1.58 g/cm³
Hardener
Type
Colour
Viscosity (25 °C; rot.; 1 s-1)
Viscosity (25 °C; rot.; 10 s-1)
Density (23 °C)
ISO-CAST® hardener
Brown
Approx. 130 mPas
Approx. 120 mPas
Approx. 1.23 g/cm³
ISO-CAST® hardener LV
Brown
Approx. 50 mPas
Approx. 30 mPas
Approx. 1.23 g/cm³
Mixture
Mixing ratio resin : hardener
5 : 1 parts by weight
6.25 : 1 parts by weight
8 : 1 parts by weight
5 : 1 parts by weight (hardener LV)
6.25 : 1 parts by weight (hardener LV)
8 : 1 parts by weight (hardener LV)
Colour
Blue (other colours on request)
Density (23 °C)
5 : 1 parts by weight
6.25 : 1 parts by weight
8 : 1 parts by weight
5 : 1 parts by weight (hardener LV)
6.25 : 1 parts by weight (hardener LV)
8 : 1 parts by weight (hardener LV)
Approx. 1.50 g/cm³
Approx. 1.50 g/cm³
Approx. 1.50 g/cm³
Approx. 1.50 g/cm³
Approx. 1.50 g/cm³
Approx. 1.50 g/cm³
Potlife (23 °C) /
Gel time (23 °C)
5 : 1 parts by weight
6.25 : 1 parts by weight
8 : 1 parts by weight
5 : 1 parts by weight (hardener LV)
6.25 : 1 parts by weight (hardener LV)
8 : 1 parts by weight (hardener LV)
Approx. 70 min / approx. 140 min
Approx. 80 min / approx. 160 min
Approx. 90 min / approx. 180 min
Approx. 70 min / approx. 140 min
Approx. 80 min / approx. 160 min
Approx. 90 min / approx. 180 min
Mixed viscosity (25 °C; rot.; 1 s-1)
5 : 1 parts by weight
6.25 : 1 parts by weight
8 : 1 parts by weight
5 : 1 parts by weight (hardener LV)
6.25 : 1 parts by weight (hardener LV)
8 : 1 parts by weight (hardener LV)
Approx. 5,600 mPas
Approx. 7,000 mPas
Approx. 9,000 mPas
Approx. 4,200 mPas
Approx. 5,500 mPas
Approx. 7,200 mPas
Mixed viscosity (25 °C; rot.; 10 s-1)
5 : 1 parts by weight
6.25 : 1 parts by weight
8 : 1 parts by weight
5 : 1 parts by weight (hardener LV)
6.25 : 1 parts by weight (hardener LV)
8 : 1 parts by weight (hardener LV)
Approx. 3,700 mPas
Approx. 4,700 mPas
Approx. 5,700 mPas
Approx. 2,400 mPas
Approx. 3,000 mPas
Approx. 4,000 mPas
Cured product
Under standard curing condition
(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: 4h RT + 24h 80 °C)
5 : 1 parts by weight
6.25 : 1 parts by weight
8 : 1 parts by weight
5 : 1 parts by weight (hardener LV)
6.25 : 1 parts by weight (hardener LV)
8 : 1 parts by weight (hardener LV)
Approx. 55 / approx. 70
Approx. 57 / approx. 60
Approx. 43 / approx. 40
Approx. 47 / approx. 50
Approx. 50 / approx. 55
Approx. 40 / approx. 42
Long-term temperature resistance /
Short-term temperature resistance
5 : 1 parts by weight
6.25 : 1 parts by weight
8 : 1 parts by weight
5 : 1 parts by weight (hardener LV)
6.25 : 1 parts by weight (hardener LV)
8 : 1 parts by weight (hardener LV)
Approx. 130 °C / approx. 210 °C
Approx. 130 °C / approx. 210 °C
Approx. 130 °C / approx. 210 °C
Approx. 130 °C / approx. 210 °C
Approx. 130 °C / approx. 210 °C
Approx. 130 °C / approx. 210 °C
Flame retardancy test according to UL94
5 : 1 parts by weight
6.25 : 1 parts by weight
8 : 1 parts by weight
5 : 1 parts by weight (hardener LV)
6.25 : 1 parts by weight (hardener LV)
8 : 1 parts by weight (hardener LV)
V-0 (6 mm)
V-0 (6 mm)
V-0 (6 mm)
V-0 (6 mm)
V-0 (6 mm)
V-0 (6 mm)
Glass transition temperature (midset)
5 : 1 parts by weight
6.25 : 1 parts by weight
8 : 1 parts by weight
5 : 1 parts by weight (hardener LV)
6.25 : 1 parts by weight (hardener LV)
8 : 1 parts by weight (hardener LV)
Approx. 25 °C
Approx. 13 °C
Approx. -2 °C
Approx. 25 °C
Approx. 13 °C
Approx. -2 °C
Tensile strength (5A specimen)
(2 mm thickness; speed: 10 mm/min; 23 °C)
5 : 1 parts by weight
6.25 : 1 parts by weight
8 : 1 parts by weight
5 : 1 parts by weight (hardener LV)
6.25 : 1 parts by weight (hardener LV)
8 : 1 parts by weight (hardener LV)
Approx. 17 N/mm2
Approx. 7.40 N/mm2
Approx. 3.80 N/mm2
Approx. 8.30 N/mm2
Approx. 5.60 N/mm2
Approx. 3.00 N/mm2
Elongation at break (5A specimen)
(2 mm thickness; speed: 10 mm/min; 23 °C)
5 : 1 parts by weight
6.25 : 1 parts by weight
8 : 1 parts by weight
5 : 1 parts by weight (hardener LV)
6.25 : 1 parts by weight (hardener LV)
8 : 1 parts by weight (hardener LV)
Approx. 20 %
Approx. 55 %
Approx. 45 %
Approx. 60 %
Approx. 75 %
Approx. 60 %
Tear resistance
(W-specimen; incision; speed: 10 mm/min; 23 °C)
5 : 1 parts by weight
6.25 : 1 parts by weight
8 : 1 parts by weight
5 : 1 parts by weight (hardener LV)
6.25 : 1 parts by weight (hardener LV)
8 : 1 parts by weight (hardener LV)
Approx. 57 N/mm
Approx. 22 N/mm
Approx. 9 N/mm
Approx. 27.5 N/mm
Approx. 15.5 N/mm
Approx. 7.85 N/mm
Dielectric strength
5 : 1 parts by weight
6.25 : 1 parts by weight
8 : 1 parts by weight
5 : 1 parts by weight (hardener LV)
6.25 : 1 parts by weight (hardener LV)
8 : 1 parts by weight (hardener LV)
> 20 kV/mm
> 20 kV/mm
> 20 kV/mm
> 20 kV/mm
> 20 kV/mm
> 20 kV/mm
Dielectric loss factor tan δ (25 °C; 500 V AC; 50 Hz)
5 : 1 parts by weight
6.25 : 1 parts by weight
8 : 1 parts by weight
5 : 1 parts by weight (hardener LV)
6.25 : 1 parts by weight (hardener LV)
8 : 1 parts by weight (hardener LV)
Approx. 0.09
Approx. 0.09
Approx. 0.11
Approx. 0.05
Approx. 0.09
Approx. 0.10
Relative permittivity (25 °C; 500 V AC; 50 Hz)
5 : 1 parts by weight
6.25 : 1 parts by weight
8 : 1 parts by weight
5 : 1 parts by weight (hardener LV)
6.25 : 1 parts by weight (hardener LV)
8 : 1 parts by weight (hardener LV)
Approx. 5.20
Approx. 5.50
Approx. 7.50
Approx. 5.10
Approx. 5.60
Approx. 7.50
Insulation resistance (25 °C; 500 V DC)
5 : 1 parts by weight
6.25 : 1 parts by weight
8 : 1 parts by weight
5 : 1 parts by weight (hardener LV)
6.25 : 1 parts by weight (hardener LV)
8 : 1 parts by weight (hardener LV)
Approx. 1.30×1012 Ω
Approx. 7.30×1011 Ω
Approx. 1.40×1011 Ω
Approx. 2.50×1012 Ω
Approx. 1.30×1012 Ω
Approx. 1.50×1011 Ω
Volume resistance (25 °C; 500 V DC)
5 : 1 parts by weight
6.25 : 1 parts by weight
8 : 1 parts by weight
5 : 1 parts by weight (hardener LV)
6.25 : 1 parts by weight (hardener LV)
8 : 1 parts by weight (hardener LV)
Approx. 2.90×1014 Ωxcm
Approx. 1.10×1014 Ωxcm
Approx. 1.50×1013 Ωxcm
Approx. 4.20×1014 Ωxcm
Approx. 1.80×1014 Ωxcm
Approx. 2.00×1013 Ωxcm
Surface resistance (25 °C; 500 V DC)
5 : 1 parts by weight
6.25 : 1 parts by weight
8 : 1 parts by weight
5 : 1 parts by weight (hardener LV)
6.25 : 1 parts by weight (hardener LV)
8 : 1 parts by weight (hardener LV)
Approx. 2,40×1013 Ω
Approx. 1,40×1013 Ω
Approx. 1,45×1012 Ω
Approx. 2,40×1013 Ω
Approx. 1,40×1013 Ω
Approx. 1,45×1012 Ω
Thermal conductivity
5 : 1 parts by weight
6.25 : 1 parts by weight
8 : 1 parts by weight
5 : 1 parts by weight (hardener LV)
6.25 : 1 parts by weight (hardener LV)
8 : 1 parts by weight (hardener LV)
Approx. 0.80 W/K×m
Approx. 0.80 W/K×m
Approx. 0.70 W/K×m
Approx. 0.80 W/K×m
Approx. 0.80 W/K×m
Approx. 0.80 W/K×m
Water absorption
After 28 days in water (immersion; 23 °C)
5 : 1 parts by weight
6.25 : 1 parts by weight
8 : 1 parts by weight
5 : 1 parts by weight (hardener LV)
6.25 : 1 parts by weight (hardener LV)
8 : 1 parts by weight (hardener LV)
Approx. 0.40 %
Approx. 0.75 %
Approx. 1.60 %
Approx. 0.50 %
Approx. 0.60 %
Approx. 1.30 %
Water vapor permeability
(75 % relative humidity; 23 °C; 1 mm thickness)
5 : 1 parts by weight
6.25 : 1 parts by weight
8 : 1 parts by weight
5 : 1 parts by weight (hardener LV)
6.25 : 1 parts by weight (hardener LV)
8 : 1 parts by weight (hardener LV)
Approx. 5.30×10-7 g/(day×mm2)
Approx. 7.30×10-7 g/(day×mm2)
Approx. 9.30×10-7 g/(day×mm2)
Approx. 5.75×10-7 g/(day×mm2)
Approx. 6.00×10-7 g/(day×mm2)
Approx. 1.00×10-6 g/(day×mm2)
Storage and transport
Store in a dry, airtight container at 20–35 °C. Can be stored for at least 12 months in original sealed containers under the above conditions. Short-term deviations during transport and storage of the resin are acceptable. For ISO-PUR® Hardener LV, ensure continuous temperature control above 18 °C.
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 the resin container thoroughly. Weigh the resin and hardener in the specified mixing ratio and mix for 1 – 3 minutes (depending on the batch size 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 processing is also possible.
The EC safety data sheet provides information on safety-relevant product properties.
Hardener component (containing diisocyanate): Since August 24, 2023, appropriate training must be provided before industrial or commercial use.