• Applicable to various proceprocesses. molding, dispensing, etc.)
  • High viscosity for less flowability
  • Excellent transparency
  • Low shrinkage
  • Wide cure temperature range
  • No Oxygen inhibition

Specific features of SEMICOSIL® 831 A/B

  • Addition Curing
  • Fast curing under heat
  • Highly transparent
  • No chemical shrinkage
  • Two-component
  • Sealingng or Dam material for optical bonding
  • Prevent spreading out of bonding material
  • Maintain thickness of bonding material
  • Encapsulation of optical & electronic components

Surface preparation

All surfaces must be clean and free of contaminants that will inhibit the cure of SEMICOSIL® 831.

Examples of inhibiting contaminants are sulfur-containing materials, plasticizers, urethanes, amine-containing materials, and organometallic compounds – especially organotin compounds.

If a substrate’s ability to inhibit cure is unknown, a small-scale test should be run to determine compatibility.


Mixing ratio

Part A (SEMICOSIL® 831 A) : Part B (SEMICOSIL® 831 B) = 1 : 1



Curing speed can be adjusted by temperature and time.

We recommend running preliminary tests to optimize conditions for a particular application. Comprehensive processing instructions are given in below.

- 30 min at 70°C

- 10 min at 150°C

Cure time can be increased or decreased depending on the applied temperature.





SEMICOSIL® 831 A/B should be stored between 5 °C and 30 °C and below 60%RH in the tightly closed original container.


The 'Best use before end' date (Shelf life) of each batch appears on the product label.


Storage beyond the date specified on the label does not necessarily mean that the product is no longer usable. In this case however, the properties required for the intended use must be checked for quality assurance reasons.


Shelf life;

  • SEMICOSIL® 831 A : 1 year
  • SEMICOSIL® 831 B : 1 year

Sales and support

Wacker Chemical Corporation
3301 Sutton Road
Adrian, MI 49221-9397
United States
+1  888  922-5374 (Phone)

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