SynChem – Resins & Varnishes Voltacast 3110 Polyurethane casting resin

Cold-curing 2-component-polyurethane casting resin.

Voltacast 3110 is a pigmented, filled and cold-curing two-component polyurethane casting resin with low temperature development while curing, based on polyester containing hydroxyl-functional groups. The hardener is based on an aromatic polyisocyanate.

Download datasheet


  • Embedding and potting of transformers and electronics, especially of heat-sensitive electronic parts such as transistors, photo cells, etc.
  • Voltacast 3110 contains non-abrasive fillers and is therefore especially suitable for sensitive mixing and dispensing equipment.


  • Thermal class E - B (120-130)
  • Flame retardant UL 94 V-2
  • UL approved file no. E 72640
  • RoHS-compliant 2011/65/EU
  • REACh-compliant 2006/121/EU
  • Polybromited diphenylether 2003/11/EU
  • Electrical Insulation Systems in acc. with UL 1446 (IEC 61858):
Class 130 R150HE Table II
  Z130HE Table II
Class 155 R201HE Table II

Delivery forms

Voltacast 3110 is supplied in non-returnable one-way containers of 20 kg and in 250 kg. Additionally 1000 kg containers (returnable) are available (not for oversea export).




In closed original cans and at 25 °C storage temperature maximum the resin can be stored for 12 months. The hardener can be stored for more than 6 months under the same conditions. Both resin and hardener have to be protected against water and humidity and therefore must not be stored outside. Additionally the respective hardener must be stored and transported frost-protected (above 10 °C).


After curing of 48 hours at 20°C minimum the resin compound can be fully stressed (both mechanically and electro-technically).


Cured resin is biologically inactive and not dangerous to health. When processing the liquid components please refer to the respective Material Safety Data Sheets (MSDS’s).


Once cured the resin compound is almost insoluble. Therefore, application equipment should be cleaned regularly with cleaner Voltatex® T050. All equipment cleaning and maintenance should be carried out in accordance with the equipment manufacturer’s instructions.


Due to the contents of fillers which will settle to the ground during a longer storage period Voltacast 3110 needs to be stirred up homogenously (without including foam) prior to use. In any case the resin shall rest for about 2 hours after stirring to allow degasing The time needed for degasing the resin may be shortened by storing the resin at approx. 60 °C or at a vacuum of approx. 20 mbar. Provided the mixture is consumed very soon, the hardener Voltacast H131 or Voltacast H132 may be added to the warm resin. Otherwise the resin has to cool down to room temperature again in order to avoid a significant shortening of the mixture’s pot life.

Casting resin, hardener and mixtures made must be protected against humidity! The temperature in the working area must be above 18 °C!
The same way it is essential to dry the parts the casting resin shall be applied on. An example for best practice is to extract all humidity on and inside the parts used by drying them at approx. 50 °C for about 1 hour, as otherwise the resin may form gas bubbles while curing.
Hardener Voltacast H131 respectively Voltacast H132 shall be added to the casting resin in the mixing ratio stated above. The mixture has to be stirred homogenously and carefully without including foam. Voltacast 3110 and Voltacast H131 resp. Voltacast  H132 can be applied on all common mixing and dispensing equipment with our without applying vacuum.

Pot life of Voltacst 3110 with Voltacast H131: approx. 40 min. at room temperature

Pot life of Voltacast 3110 with Voltacast H132: approx. 50 min. at room temperature

Technical data

Property Unit of measure Conditions  Values Voltacast H131  Values Voltacast H132  Test method 
Shore-A-hardness    after 2 months   75 ± 10 acc. to DIN 53505
Shore-D-hardness    after 3 days (20±5)   acc. to DIN 53505
Shore-D-hardness    after 4 weeks 35 ± 5   acc. to DIN 53505
Shore-D-hardness    after 2 months 40 ± 10   acc. to DIN 53505
Water absorption  after 96h at 23°C 0.17 ± 0.02 - IEC 60455-2; test method 1 acc. to ISO 62
Property Unit of measure Values  Test method 
Temperature index  °C  120 -130 IEC 60216. 20000h-value. weight loss 5%-limit
Property Conditions  Werte  Test method 
Resistance  transformer oil, org. solvents and vapours resistant IEC 60455-2, test method acc. ISO 175
Liquid phase
Property Unit of measure Values Voltacast 3110  Values with H131  Values with H132  Test method 
Curing time  min  24 h at RT + 5 h at 80°C      
Impact on enamelled wires    compatible with all common enamelled wires      
Mixing ratio  weight-%    100 : 30 100 : 30  
Viscosity resin + hardener  mPas  1500 ± 350 1050 ± 350 500 ± 50 DIN 53019 at 25 °C
Pot-Life  min    40 ± 15 50 ± 15 (100g-test) at 20-23 °C
Property Unit of measure Values with H131  Test method 
Creep resistance    CTI (175-275)M (0.15-0.25) DIN IEC 112
Dielectric strength at 23 °C after 96 h storage at 92 % r.h.  kV/mm  15-24 IEC 60455-2; test method acc. IEC 60243-1
Dielectric strength at 23 °C and 50 % r.h.  kV/mm  38-57 IEC 60455-2; test method acc. IEC 60243-1
Dielectric strength at 105 °C after 168 h oil immersion  kV/mm  55-73 IEC 60455-2; test method acc. IEC 60243-1
Dielectric constant at 23 °C between 50 Hz and 1 MHz    4.4 - 5.4 acc. DIN 53483
Loss factor cross section 0.2=200x10^-3  °C  120 - 130 acc. DIN 53483
Loss factor at 23 °C from 50 Hz and 1 MHz    0.04 - 0.05 acc. DIN 53483