Electrically conductive additive system and method of making same
View Patent ↗An electrically conductive additive system comprising carbon nanofibers and, optionally, electrically conductive particulate material mixed in a liquid component. The carbon nanofibers can be characterized by having a diameter between about 70 to about 200 nanometers, a length between about 50 to about 100 microns, and graphitic planes having a stacked cone-type structure.
1. An electrically conductive additive package comprising:
carbon nanofibers characterized by having a diameter between about 70 to about 200 nanometers, a length of about 50 to about 100 microns, and graphitic planes having a stacked cone-type structure; and
conductive carbon black.
2. The additive package of claim 1 wherein the carbon nanofibers and conductive carbon black are dispersed in a liquid component.
3. The additive package of claim 2 further comprising a dispersing agent.
4. The additive package of claim 2 wherein the liquid component is selected from the group consisting of polyester grinding vehicles, polyol grinding vehicles, epoxies, plasticizers, monomers, and any combination thereof.
5. The additive package of claim 1 wherein the carbon nanofibers are further characterized by having a dispersive surface energy ranging between about 20 to about 285 mJ/m 2 .
6. A method of preparing an electrically conductive additive package of claim 1 , the method comprising the steps of:
preparing a first suspension including the carbon nanofibers dispersed in a first liquid component;
preparing a second suspension including the carbon black dispersed in a second liquid component; and
mixing the first and second suspensions together to form the electrically conductive additive package.
7. The method of claim 6 wherein the step of preparing a first suspension includes de-agglomerating the carbon nanofibers present in the first suspension.
8. The method of claim 7 wherein the de-agglomeration step is accomplished by a three-roll mill.
9. The method of claim 6 wherein the first and second liquid components are substantially the same.
10. The additive package of claim 2 wherein the liquid component comprises between about 75 wt % and 98 wt % of the total additive package.
11. The additive package of claim 2 wherein the carbon nanofibers comprises between about 1 wt % and 15 wt % of the total additive package.
12. The additive package of claim 8 wherein the carbon black comprises between about 1 wt % and 20 wt % of the total additive package.