Thermally conductive plastic compositions, extrusion apparatus and methods for making thermally conductive plastics

A thermally conductive composition comprising:

• a resin material;
• and
• a thermally conductive filler composition dispersed in the polymer material, wherein the thermally conductive filler composition comprises a blend of (a) a boron nitride, a graphite, or a combination thereof;
• (b) a talc, and (c) a silane, and the thermally conductive composition has an in-plane thermal conductivity of about 2 W/mK or greater, a through-plane thermal conductivity of about 0.9 W/mK or greater, or both.

A filler composition comprising a blend of:

• (a) from about 5 weight percent to about 95 weight percent of a boron nitride, a graphite, or a combination thereof;
• (b) from about 5 weight percent to about 95 weight percent of a talc;
• (c) from about 0.1 weight percent to about 6 weight percent of a silane;
• and
• (d) from about 0.1 weight percent to about 60 weight percent of wollastonite, calcium carbonate, or a combination thereof.