Conductive Polymer Composites for Electrostatic Discharge Applications
Publication Date: 2003-Aug-05
The IP.com Prior Art Database
Vijay Wani: INVENTOR [+4]
Conductive composites with low metal and metallized fiber content for electrostatic Discharge and painting applications with good molded part aesthetics.
This invention pertains to a unique method of combining conductive fibers at very low loading levels within a polymer matrix to form a molded composite which provides electrical conductivity sufficient for protection from Electrostatic Discharge (ESD), and low to moderate levels of shielding protection against electromagnetic emission.
Electrostatic Discharge and painting applications require moderate levels of electrical conductivity, and conductive particulate fillers such as carbon are commonly employed to provide the desired electrical properties. As example, arc discharge to disk drives and other exposed parts (keyboards, etc.) of a computer system can conduct the arc current into and through the electronic circuitry, resulting in malfunction or destruction of components.
It has been found that specific metal and metallized fiber combinations above sufficient overall loading contents are applicable to electromagnetic shielding applications [reference US20030089892A1] and have been demonstrated to be more effective from a combined processing and performance standpoint than use of individual fiber types alone. Such conductive composites with metal and metallized fiber combinations added at the molding machine hopper are additionally able to satisfy requirements for ESD applications (electrical conductivities resulting in approximately ³10-20 dB of shielding) at surprisingly low fiber content levels. These low required fiber levels permit good molded part aesthetics to be achieved, and additionally allow the use of color concentrates to vary tints. Specific formulation examples are...