GONZALES, TX - Rockwood’s clay-based additives business has announced a global price increase of up to 20 percent according to product type, effective January 1, 2011. This action impacts all markets and regions represented by Southern Clay Products and Rockwood Additives and encompasses all product lines, including Claytone® and Tixogel® organoclays for solvent-based systems, as well as Laponite®, Optiflo® and Optigel® additives for water-based systems.