Opti-tec 7020 is a clear potting compound

Opti-tec 7020

Optically Clear Silicone Potting Compound

Opti-tec 7020 silicone potting compound transmission curveOpti-tec 7020 1.1 kg kitOpti-tec 7020 250g twinpack

Opti-tec™ 7020 Optically Clear Silicone Rubber Potting Compound is a two part, clear liquid silicone elastomer which will cure at room temperature or can be accelerated at elevated temperatures. It has a low viscosity, which allows for ease of flow around complex parts, providing electrical insulation and shock resistance. Its combination of transparency, non-yellowing and compliance makes it suitable for encapsulation of sensitive electronic or opto-electronic parts (e.g. LEDs), protecting the components from vibration, moisture and atmospheric contaminants.

  • Optically clear
  • Compliant
  • Room or low temperature cure
  • Non-yellowing catalyst system
  • Low shrinkage
  • Excellent for protecting LEDs or solar applications
  • Convenient 10:1 mixing ratio for use in automatic dispensing equipment or hand mixing
  • Low viscosity which allows for ease of flow around complex parts, providing electrical insulation and shock resistance
  • Contains no solvents
  • Has a chemical composition which provides hydrolytic stability and reversion resistance. It is an addition cure silicone with a platinum catalyst.
  1. Optical assembly
  2. Opto-electronics, photonics, LEDs
  3. Optical encapsulation & glob topping, casting, potting
  4. Solar panels
  5. Electronics potting


Opti-tec 7020 is available in twinpacks or in bulk.

For bulk, weigh 10 parts of Part A to 1 part of Part B. Allowable tolerance on the measured weight for either Part A or Part B is +/-2.5%. The mixing container should be 4 to 5 times larger than the volume of silicone. Use stainless steel, HDPE, polypropylene, etc. Using clean tools, thoroughly mix the A and B components.

Twinpack packaging

The twinpack sachet is a clear film sachet, with the resin and hardener separated by a removable clip and rail divider. Click here for twinpack mixing instructions.

Care should be taken to avoid excessive aeration. For many applications, natural degassing will be sufficient. If degassing is required, intermittently evacuate at 20-40 mbar for 15-30 minutes. Leave for a few minutes after releasing the vacuum to allow surface bubbles to collapse.

Cure begins as soon as the components are mixed in the recommended ratio. Complete cure is normally achieved in 16 to 24 hours at ambient temperatures of 20-30°C. Cure can be accelerated by heating to 50-120°C.

Uncured properties
Colour Part A – clear
Part B – clear
Mixed – clear; colourless
Viscosity (mPa.s) Part A – 4000
Part B – 500
Mixed – easily pourable
Specific gravity Part A – 1.02
Part B – 1.01
Mix ratio 10:1 Part A to Part B
Pot life (@ 23°C) 4 hours
Cure schedule (approx maximum time) 25°C – 20 hours
100°C – 60 mins
Cured properties (1 hour @ 100°C)
Hardness, Shore A 40
Temperature range -60 to 200°C
Tensile strength 4.8 MP
Elongation at break 100%
Linear shrinkage < 0.1%
CTE (ppm/°C) 275
Dielectric strength (kV/mm) 20
Dielectric constant @ 1000Hz 2.69
Dissipation factor @ 1000Hz 0.0006
Volume resistivity (ohm-cm) 1.7 x 1015
Thermal conductivity (W/m K) 0.18
Specific heat (kJ/kg) 1.255
Refractive index @ 589nm 1.405
Transmittance @ 400nm 90.3%


Opti-tec 7020 silicone potting compound transmission curve

Transmittance of Opti-tec 7020 @ 1cm path length

Opti-tec 7020 is supplied in matched kits in a 10 to 1 ratio of Part A to Part B – standard size is 1.1kg total. Unopened containers have a shelf life of 12 months at ambient temperatures. Alternatively, Opti-tec 7020 is supplied in pre-weighed 250 gram twinpacks.
Opti-tec 7020 1.1 kg kitOpti-tec 7020 250g twinpack

Part number Description
OPT7020-1.1KG 1.1kg kit
OPT7020-250G 250g twinpack

Contact Details

17 Station Field Industrial Estate,
Banbury Road, Kidlington
Oxfordshire, England

t 01865 842842
e info@intertronics.co.uk


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March 2016 - Version 5.1