Extender resins to enhance processing and end product properties in paste applications

Abstract

PVC paste formulations are defined on the one hand by the required properties of the finished product, and on the other hand, by the essential processing properties. It is often difficult to reconcile both demands. The use of extender resins as viscosity modifiers and for gloss control is discussed. Extender resins (also named blending resins or filler resins) decrease the paste viscosity in general and also suppress flow anomalies like dilatancy. They increase the matt effect of the surface of the finished article. The strength of these effects depends on the grades used. Special grades avoid the impact some extender resins can have on the mechanical properties. Special copolymeric blending resins have the additional benefit of accelerating fusion of the paste. These features make extender resins a powerful component in paste formulations, as is illustrated by the examples given.