Лако-красочные материалы — производство

Another class of thickeners for solventborne coatings is the overba­sed calcium sulfonates. They contain acicular microcrystals (0.5 to 3 pm) of calcium carbonate associated with the long chain sulfonate by adsorption through the sulfonate group. The non-polar hydro­carbon chains (typically C12 to C30) form intermolecular bonds through weak van der Waals forces, producing a stable microstruc­ture that causes an increase in viscosity suitable for anti-settling and anti-sagging properties. The gel structure achieved by them is strongly shear thinning.

The main advantages of these thickeners are their ease of incor­poration, temperature stability, effectiveness, good sag resistance and very little effect on gloss. On the other hand, due to their high alkalinity, they cannot be used in acid catalyzed systems. They make the product more water sensitive.