Polymer-related chemicals

UV-Curing Thermally Conductive Insulation Coating Agent
WTCR Series

WTCR series is a UV-curable thermally conductive insulation composition. An insulating film with high thermal conductivity can be easily formed in a short time by UV-irradiation. For thermally conductive cured paint compositions, the limie od thermal conductivity is at most 2W/mk. The thermal conductivity of WTCR-001 reached 5W/mk. WTCR-001 can be used with aluminum or copper substrates owing to its high adhesion to metals.

Development Process
Combining our photobase generator with a conventional UV radical curing agent shows excellent curability and high adhesion to metal substrates even when exposed to large amounts of heat dissipation filler. We have developed the WTCR series by applying these technologies.

Application Examples
Aluminum substrate, Copper substrate


  • Pre-mixed, so it is not necessary to measure and mix by yourself
  • Fast curing with high pressure mercury lamp or UV-LED(365nm)
  • Thermal conductivity: approximately 5 W/m・k (Existing products: 1~2W/m・K)
  • High adhesion to metallic substrates made of aluminum or copper
  • High insulation resistivity
  • No defects (cracks) and no degradation of electrical properties after 100 hours under the condition of 80℃/85%RH
  • Curable with heat
    (The shaded or deep part which does not cure completely with UV is curable)
Cured film

Product Data

Basic Properties

Conditions Pre-bake:100℃/5min. UV-LED 10 sec (@365nm 300mW/cm2) Post-bake:150℃/10min.
Appearance Gray slurry

Physical Properties

Thermal conductivity(W/m・K) by Laser Flash Method Approximately 5W/m・K
Adhesion(Al, Cu) 100/100(Lattice evaluation)
Hardness Pencil hardness 6H<
Whiteness W=64

Electrical Properties

Insulation resistivity Surface resistivity 1×1012-13 Ω/□
Volume resistivity 1×1014 Ω・cm or more
Voltage endurance test(100/500V 1min.) No abnormality
Leakage current(@100/500V 1min.) 0.02mA
Dielectric constant(1 MHz) 3.3
Dielectric loss(1 MHz) 0.02