Thermal Paste Cross

I need a heatsink compound with similar characteristics as below.

conductivity coefficient: |>3.5 |W/m-K|
heat impedance <0.105℃-in2/W|
viscosity 1000
Instantaneous temperature resistance -50~300℃|
Working temperature -30~280℃|
Silicone Compounds 5%
carbon compound 65%
Metal oxide compound 30%


We don’t seem to have any non-silicone based heatsink compounds which come even close to your 280°C specification.