Development and performance of enzymatically modified lignosulfonates as coating binders

Pigment coatings are applied to optimize the surface and printing properties of coated papers (Huang and Lepoutre, 1998). A coating color consists of several components having different functions. To bind the pigments and to fix the coating layer to the base paper, today mainly petroleum based latex binders are used. There are efforts to increasingly substitute these petroleum-based products by renewable binders (Flory et al., 2013; Gosselink et al., 2010). Biopolymers like starch, proteins and lignocellulosic materials are gaining in importance in paper coating applications (Imam et al, 2013). Technical lignins, such as lignosulfonates or kraft lignins, are the major industrial by-products of the pulping industry and are an abundant source of biopolymers, which today are mainly used for energy production. Material applications of technical lignins for special products is only between 1 and 2% (Gosselink et al., 2004), which is mainly due to the heterogeneity of technical lignins. Still more and more applications of technical lignins as building block for polymers, resins or adhesives are being developed recently (Stewart, 2008).