Opti-tec 4200 Optically Clear Polyurethane Encapsulant & Potting Compound

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About Opti-tec 4200 Optically Clear Polyurethane Encapsulant & Potting Compound

Opti-tec™ 4200 is a clear, water-white polyurethane resin designed for the encapsulation of electronics, LEDs, electrical products and other items where high transparency and aesthetics are important. Opti-tec 4200 optically clear potting compound has excellent non-yellowing colour stability, due to the incorporation of both UV resistant base materials and the addition of UV stabilisers and antioxidants.

Opti-tec 4200 is used for a range of applications from high value LED panels to decorative giftware (e.g. flower impregnation). It is also an excellent resin for the doming of badges, labels and decals.

Opti-tec 4200 is available in a harder version (Opti-tec 4210) and a translucent milky-white version (Opti-tec 4220).


Features & Benefits

  • Clear, water-white, non-yellowing
  • Excellent long term UV stability
  • Scratch and mark resistant
  • Non-toxic
  • Easy to mix and process
  • Very low viscosity
  • Excellent penetration and air release properties
  • Low shrinkage
  • Low exotherm


  • Protection of LEDs – LED bars, LED arrays, luminaires
  • LED potting or LED encapsulation
  • Electronics potting
  • Dome coating of labels and badges
  • High quality, clear casting


OPT4200 application 600px    OPT4200 application 2 600 px


Typical properties Mixed Resin Hardener
Colour Clear Clear Clear
Specific gravity (g/ml) 1.11 1.06 1.16
Viscosity mPa.s @ 25°C 600 600 600
Mix ratio by weight 0.92:1
Mix ratio by volume 1:1
Pot life 10 minutes
Gel time 20 minutes
Tack free cure 40 minutes
Minimum cure schedule 36 hours @ 20-25°C
4 hours @ 40°C
2 hours @ 60°C
* typical values – will vary according to mass, film thickness and application. Higher cure temperatures will result in greater cure shrinkage and exotherm.
Cured properties
Shore hardness A75
Operating temperature (application & geometry dependent) -55 to +120°C
Thermal conductivity < 0.21 W/mK
Tensile strength ~ 15 mPa
Elongation at break 100%
Coefficient of linear expansion 100-150 pp/m°C
Volume resistivity < 1.3 x 1012 ohm.cm
Surface resistivity < 1.4 x 1012 ohm
Dielectric strength 20 kV/mm
Water absorption 1.17% (30 days @ 25°C)
Refractive index 1.47-1.48
Opti-tec 4200 is RoHS compliant and contains 0% REACH SVHC

Opti-tec 4200, 7020, 5012 transmission
Optical transmission of Opti-tec 4200, Opti-tec 7020, Opti-tec 5012


Safety Data Sheets
For the latest SDS for this product, please e-mail msds@intertronics.co.uk

Ordering Information

Opti-tec 4200 is available in convenient side-by-side double syringe cartridges, twinpack sachets and bulk packaging.

Click here for twinpack mixing instructions.


Part number Description
OPT4200-50G Clear Polyurethane Encapsulant – 50 gram double syringe cartridge
IDM805001 Syringe Gun – for 50g cartridges
OPT4200-200G Clear Polyurethane Encapsulant – 200 gram double syringe cartridge
OPT4200-250G Clear Polyurethane Encapsulant – 250 gram twinpack sachet
OPT4200-1KG Clear Polyurethane Encapsulant – 1 kilogram kit

For best results, store away from strong oxidising agents, strong acids and strong bases. Store in a cool, well-ventilated area. Keep container tightly closed and keep in original packaging.


Next Steps

Our technical sales team are on hand to discuss your application requirements. Click here to get in touch.

Find out more information on how to purchase.

  • Last updated: July 2021
  • Version: 3.0

Statements, technical information and recommendations contained herein are based on tests we believe to be reliable but they are not to be construed in any manner as warrantees expressed or implied. The user shall determine the suitability of the product for his intended use and the user assumes all risk and liability whatsoever in connection therewith.