There are many factors that contribute to the increased interest in developing waterborne coatings - from the depletion of natural petroleum resources and the spiraling escalation in prices of crude oil to toxicological effects of certain paint and coatings ingredients on human health or restrictive environmental legislation, to name just a few. Research and product development increasingly focus on the area of alkyd emulsions for architectural paint. Today, alkyd emulsions are a growing technology with low volatile organic compounds (VOCs) for the paint and coatings industries, forming an excellent basis for the development of paint with the highest possible level of flow and leveling characteristics. Alkyd emulsions are a truly green technology, they largely consist of renewable vegetable raw materials - the major component being vegetable oil (over 40 percent bio-sourced carbon). Despite their generally good properties, acrylic-emulsion paints cannot match the high gloss levels achieved by traditional solvent-based alkyd paints. Alkyd-emulsion paints are therefore increasingly gaining consumer interest and market share. However, unmet customer needs for high-gloss, low- and high-solids paints with optimal application properties, such as paint stability, brushability, flow and gloss retention, have led to the development of novel nonionic synthetic associative thickeners (NSATs). The challenge lies in obtaining the right application properties along with optimal dry film properties and predictable Theological characteristics using a well-defined thickener package. By using carefully selected combinations of newly developed NSATs, the right balance of sag, leveling, gloss, brushability, hiding and paint stability can be obtained. Different strategies for formulating high-performance alkyd emulsion-based paints will be reviewed and discussed using the latest developments in synthetic rheological additives. Advanced rheological testing delivered a full viscosity profile of paints thickened with different NSATs to ultimately reach optimal application and dry film properties. Application data clearly show that by combining different NSATs, formulators will be able to dial-in any desired viscosity profile, with each component bringing its own unique and optimum contribution to the paint and its application characteristics.
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