Thickener latex paint, rheological properties

ATER-SOLUBLE POLYMERS (WSPs) are an important class of industrial polymers. They have many applications in solution and in the solid state. In solution, they are widely used as thickeners to control the rheology of various water-based formulations, such as latex paints, drilling muds, foods, cosmetics, and building materials. Chemically modified natural polysaccharides such as starch, cellulose, and guar are a large class of commercial water-soluble polymers. The appropriate chemical modification of these polysaccharides can lead to the modified solution properties needed for specific applications. 

Uses Associative thickener, rheology control agent, flow aid, leveling agent in interior and exterior latex paints Features Improves high shear vise., roller spatter high resist, to enzymatic degradation delayed solubility Properties Whitish powd. 98% < 425 m particle size sol. in water vise. 250-600 mPa-s-min. (1%, 20 C) pH neutral (1%) nonionic 4% max. water, 4.5% max. salt Use Level 0.3-0.5% (on total paint wt.)... 

Uses Thickener, vise, stabilizer for factory- or in-store tinted paints, acrylic, vinyl acrylic or other water-based latexes Features For low to high shear rheology Properties Nonionic 0ptigel 800 [Sud-Chemie AG]... 

Uses Associative thickener, rheology control agent, vise, builder, stabilizer for aq. systems for indoor and outdoor paints, latex and anticorrosive paints, syn. resin-bound renderings, adhesives, and paste fillers Properties Wh. lightly transparent liq. emulsion disp. in water dens. 1.06 g/ml (20 C) pH = 6.5 nonionic 40% act. in water/butyltriglycol (40/ 20)... 

NW, Pigment Volume Content, and Latex. Pigment volume content (PVC) and latex type and grade are important for optimizing dry film properties. Percent NW is usually governed by the desired cost of the final product. The formulator usually does not use these variables to optimize paint rheology but should be aware of how they affect thickener efficiency. 

Chem. Descrip. Hydrophobe modified ethoxylate Uses Rheology control agent, associative thickener for latex systems, high gloss and semi-gloss coatings, waterborne architectural and industrial paints, printing inks, suitable for acrylics, styrene-acrylics Properties Clear liq. dens. 8.75 Ib/gal vise. 1800 cps VOC 20% (EPA Method 24) 40% act., 40% water Use Level 1.0-3.0% on total wt. 

Surfactants and dispersants are used to disperse pigment, mineral and latex particles to promote suspension stability, to minimize the viscosity contribution of particle flocculation or agglomeration, and to enable higher solids content. Adjusting paint theology for optimal in-can stability and application properties normally requires the use of thickeners, thixotropes and rheology modifiers of various types. 

---