An Overview of Non-Black Fillers for Rubber

Naturally-occurring, ground and synthesized materials with small particle sizes have been used as fillers for rubber compounds since the earliest days of the rubber industry. However, only amorphous precipitated silica has become a major competitor to carbon black for applications that need the highest level of reinforcement. This paper will present an overview of the history of non-black fillers and compare the properties that maximize the reinforcement of rubber compounds. In particular, the development of highly dispersible silica (HDS) fillers which allow the production of passenger tires that have improved rolling resistance without sacrificing wet traction or treadwear will be discussed. The latest developments and potential for future improvements will be presented.