PNU-46203PNU-46203 is an electronics grade, two-component polyurethane adhesive or encapsulant for high temperature resistance. PNU-46203 is designed for the encapsulation by casting of completed circuit boards. Cured PNU-46203 is expected to meet the flammability requirements of UL 94, V-0 at thicknesses of 0.070 inch (1.8 mm) or greater. The cured materials provide long-term circuit protection and bond stability from -55°C to 125°C. PNU-46203 bonds well to most metals, ceramics and plastics as well as to epoxy and paper phenolic circuit boards.


  • PNU-46203 polymer backbone provides excellent flexibility at low and high temperatures, UV and moisture resistance. (no yellowing)
  • PNU-46203 has low shrinkage on curing
  • PNU-46203 has excellent adhesion to most substrates without primers
  • PNU-46203 is unaffected by soldering or cleaning processes
  • PNU-46203 is flame retardant
  • PNU-46203 has room temperature reparability by cutting away the material around the area of the affected component, replacing the component, then re-pot.


  • PNU-46203 contains no MDI or TDI and all active isocyanate is polymeric in nature. Therefore no extraordinary precautions against water contamination are necessary. Neither PNU-46203 Part A nor Part B should be exposed to ambient air for prolonged periods of time. The containers should be covered when not in use. If PNU-46203 Part A and B is used in a continuous mixer, the feed tanks should be vented through a desiccated air vent
  • Components to be encapsulated by PNU-46203 should be clean, dry, and not contaminated with solder flux, silicone grease, or other uncured materials
  • For evaluation and small production runs, in a metal or plastic container no more than ½ full, warm 100 g of PNU-46203 Part A to 35°C (95°F) then, add 25.0 g of PNU-46203 Part B. Mix thoroughly using a plastic or metal spatula. Degas the mixture for 10-15 minutes at 0.5 mm Hg or less to remove all entrained air
  • For high volume applications Protavic recommends that either Mixpac or meter-mix machines be used. Contact your Protavic representative for recommendations of suppliers of meter mixing equipment


The properties set out below were obtained after curing for 2 hours at 100ºC (212°F). They were determined following measurements carried out in the laboratory over a small number of tests. They are values given by way of guidance, and do not constitute a guarantee. It will be for the user, in all cases, to carry out their own tests to determine whether the PNU-46203resin can be used for the particular application the user has in mind.


Refer to the attached material safety data sheet.


PNU-46203 is available in two-part Mixpac.  For larger kits, please contact Protavic America, Inc.