There have been significant advancements in the use of special clays as rheological additives in paint and coatings systems. Special clays such as sepiolite, attapulgite and smectites comprise a particular silicate subgroup in the clay family. All of them, under the appropriate processing conditions, produce gel structures that are able to behave as shear thinning and thixotropic fluids. These properties make special clays unique in comparison to other rheological additives, improving specifically the stability and application properties of these systems. These special clays deliver good anti-settling and anti-sagging characteristics for paints and coatings, either in water or solvent systems.
Special clays also provide special absorption and adsorption characteristics. Absorption, surface activity and morphological factors allow the design of special functionalized additives that will work in a wide range of base systems and will provide new functions beyond the standard improvements that are seen in typical rheological additives.