Electrical insulation resins

Electric Insulating Resins

Silicone electric insulating resin for winding impergation of the electrical machines reparing and upgrading, electromagnetic coils, lifting magnets reparing, impregnation of wire and cable braid, anti-stick and anti-adhesive coating for metal molds.

Electrical insulation silicone resin KO-921

Product description

Electrical insulation resin KO-921 


Electrical insulation resin KO-921 is a clear homogenous solution of polymethylphenylsilxane resin in organic solvents. Polymethylphenylsiloxane resin is obtained by hydrolytic co-condensation of phenyltrichlorosilane and dimethyldichlorosilane with further polymerization.


Silicone electrical insulating resin KO-921 is used in the industrial sector in the manufacture and repair of cable and wiring products, electric motors, electrical apparatus, electrical engineering, electrical machines and equipment, in industrial, construction, metallurgical, chemical, energy and other industrial facilities:

  • Resin KO-921 is an insulation lacquer for glass winding impregnation of wires and cables, as impregnating and coating resin for materials working at temperatures up to +250°C.
  • Silicone resin KO-921 is an electrical insulation material for electric equipment and devices.
  • Protective coating of electrical equipment and devices against mold and mildew.
  • For production of heat resistant electrical insulating enamels and compounds.
  • In the food industry - as an anti-stick & anti-adhesive coating of metal forms for meat products baking:
  • Resin KO-921 - anti-adhesive coating of metal molds for meat products baking.
  • KO-921 is a protective non-stick and anti-adhesive coating of metal baking molds for meat loaves and biscuit semi-finished products.


  • Resin KO-921 has fast drying film and lowered drying temperature. The drying time of the coating at +20°C to degree 3 – max. 15-20 minutes.
  • Coating provides good dielectric properties.
  • Polymerized coating is heat resistant (up to +250°С).
  • It has high water-resistant properties.
  • Resin KO-921 is safe for food industry application (as a release, non-stick and anti-adhesive coating for metal molds baking)
  •  KO-921 electrical insulating resin has a good impregnating ability due to its low viscosity and low surface tension.
  •  It fixes individual coils and layers of winding and insulation well.
  • Forms a wear-resistant coating in the form of a smooth glossy dense and durable film.
  • Resin KO-921 has good thermal conductivity and mechanical strength.
  • It does not adversely affect copper and enamel insulation of wires.
  • Thermoelastic properties are maintained during long-term heating of the insulation in the electrical machines processing.
  • High dielectric characteristics vary slightly under the influence of high temperature and moisture.

Methods of application

Before use, resin KO-916A must be thoroughly mixed to achieve homogeneity throughout the volume. Prepare the surface: remove dirt, degrease, dry.

Application methods: impregnation, dipping, spraying, brushing.

If necessary, KO-921 can be diluted to the desired viscosity with solvents (toluene, xylene) in an amount of max. 20%.
The application of resin KO-921 is carried out at an ambient temperature of +5°C to +30°C and a humidity of max. 80%.
Drying at room temperature. Drying time at a temperature from +15°С to +35°С is 15-20 minutes. To speed up the process can be dried in an oven at a temperature of +70°C.

Consumption for single-layer application —50-100 g/m2.


Store in sealed container at temperature from -30°С to +35°С. Keep in a cool, dry, well-ventilated place, away from heaters. Protect from moisture and direct sunlight. 

The guaranteed shelf life in original container is 12 months.

Storage over the date specified on the label does not necessarily mean the product is unusable. In case if store more please check the properties of product before use.


  • Steel barrels up to 200 liters.

Safety information

The product is flammable; please follow fire safety instructions during work. The polymerized varnish coat is nontoxic, fire-safe.
Detailed instructions are given in the relevant product safety data sheet. It can be provided upon request.

  • Silkor Ltd. is a large-scale supplier and manufacturer of silicone organic electric insulating resins.

    To get a special offer or to buy an electric insulation resin, find out the current price in Ukraine or your domestic market, please, use any easy contact way:

Physical and chemical properties

Parameter name and measure unitStandard

Homogeneous transparent solution. Ligh opalescence is permissible.

Mass fraction of nonvolatile substances, %48 - 52
Viscosity according to VZ-4 viscometer with a nozzle diameter of 4 mm at +20°C, s17 - 27
The drying time of the lacquer film at (+200±5)°C to the degree of 3, minutes, max15
Mass fraction of hydrogen bonded to silicon,%, max0,001
The thermoelasticity of the lacquer film at (200° + 5) ˚С, h, min75
Optical density, max0,5
Dielectrical properties:Test conditions
R,М(15-35)°С, 45-75%
24ч (+20±1)°С, 
Specific volumetric electrical resistance of lacquer coating, Ohm*m, min1,0×10121,0×10101,0×1011
Electric strength of resin coating, MV/m, min753535
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