ISO-CAST® A765-BF
Flame retardant according to UL 94 V-0 (6 mm)
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
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. 20000 mPas
Approx. 10000 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 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
Colour
Blue (other colours on request)
Density (23oC)
5 : 1 parts by weight
6,25 : 1 parts by weight
8 : 1 parts by weight
Approx. 1,51 g/cm³
Approx. 1,51 g/cm³
Approx. 1,51 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
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
Approx. 4200 mPas
Approx. 5500 mPas
Approx. 7200 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
Approx. 2400 mPas
Approx. 3000 mPas
Approx. 4000 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: 4hRT + 24h80°C)
5 : 1 parts by weight
6,25 : 1 parts by weight
8 : 1 parts by weight
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
Approx. 130°C / approx. 210°C
Approx. 130°C / approx. 210°C
Approx. 130°C / approx. 210°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
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
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
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
> 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
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
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
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
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
Approx. 2,40×1013 Ωxcm
Approx. 1,40×1013 Ωxcm
Approx. 1,45×1012 Ωxcm
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): As of August 24, 2023, appropriate training must be provided before industrial or commercial use.