New Methods of Carbon Black Surface Modification

Abstract

The modification of the surface of carbon black is an important tool to adjust its material properties for different applications. Besides the well-known oxidation processes some new routes of surface modification were established in the last couple of years. The main feature of these new technologies is the formation of a chemical bond between the carbon black and the modification agent. This paper is intended to give an overview on new modification methods which lead to a wide range of different types of carbon black. These technologies, e.g. polymer grafting, reactions with diazonium salts and radical initiators, open up the opportunity to influence the material surface, giving rise to changes from intense hydrophilic to strong hydrophobic. An effective tool to attach modification agents on the carbon black surface is the well-known chemistry by Otto Diels and Kurt Alder. First published 75 years ago the so-called Diels-Alder reaction became a key also to new types of carbon blacks. With this reaction type it is possible to create products with variable polarities between hydrophilic and hydrophobic in order to tailor solutions for applications with special requirements. For this development the availability of new characterization methods like special DRIFTS and NMR analyses played an important role. The main targets for the commercial use of these new products are NIP (non-impact printing) applications like ink jet and electrophotography, along with coating applications.