April 10, 2007 – NEC Corp. has developed a completely new kind of bioplastic composed of plant-based material and carbon fiber, which realizes heat conductivity higher than that of stainless steel, according to the Japan Electronic News. The innovative bioplastic is expected to make electronic products more environmentally sound, while solving conventional heat release issues.
The features of the new bioplastic include creation of a cross-linked structure of carbon fiber through use of a unique binder in the polylactic acid (PLA)*1 resin, achieving high heat diffusion. With carbon fiber of 10% and 30%, the heat diffusion ability of the new bioplastic composite is comparable to and double that of stainless steel, respectively. This enables good heat conductivity in the plane direction of the PLA resin board, which is a characteristic conventionally difficult to attain in metal boards.
The composite is environmentally friendly because it is mainly composed of biomass-based components, including the binder. The biomass ratio exceeds 90%, excluding inorganic components such as the carbon fiber.
The strength and moldability of the composite have been fundamentally verified for use in electronic products. NEC’s newly developed bioplastic composite in the housings of electronic products easily releases the heat generated from electronic parts with high temperatures through whole housing surfaces, while slowing up an increase in the temperature of the housings near parts.
In addition, NEC has also discovered how to add flame retardancy – without using toxic flame retardants – and shape memory to PLA. The new bioplastic achieves high heat conductivity by a new technology for carbon-fiber cross-linking with a unique biomass-based binder, which was realized at NEC’s fundamental and environmental research laboratories. NEC will continue to develop these technologies toward realization of mass production of the bioplastic composite by the end of the fiscal year ending March 2009, after which it will start to use the composite in housings of electronic products and seek out new applications.