TekNational, Inc.
Tek-Sil® GP7X Series
If you need a gap filler with higher thermal conductivity, Tek-Sil® GP7X is rated at 17 watt/mk compared to 1.5 watt/mk for the standard "GP" material.  This material is presently available in five thicknesses. 
GP7X SeriesUnitGP7X-15GP7X-20GP7X-40GP7X-60GP7X-79
Thicknessmm0.3 +/-0.10.5 +/-0.11.0 +/-0.21.5 +/-0.022.0 +/-0.02
Widthmm200200200200200
Lengthmm150150300300300
Thermal Resistance°Cin²/W0.07 0.80.140.200.27
ColorvisualLight Gray
Thermal Conductivitywatt/m-k17
Volume ResistivityMohm·m1x105
Withstand VoltagekV/mm·AC15
Specific Gravitygr/cm³3.2
HardnessShore OO80
Elongation%35
CompressionKgf/in²@10%7572232019
50% sustain after 1 min626164524232
Continuous Use°C-60° to +200°
Flame RetardanceUL 94VV-0