HASE stands for hydrophobically-modified alkali soluble emulsion. These are tertiary polymers that build on the ASE chemistry by adding a hydrophobic acrylic ester monomer to the polymer composition.
HASE rheology modifiers retain the pH dependent behaviour, easy handling advantages and resistance to microbiological contamination of their ASE counterparts, but in addition to absorbing water, HASE rheology modifiers also thicken via hydrophobe association.
This mechanism, known as associative thickening, offers performance properties over a wider range of shear levels and enables a wider range of rheology profiles than is possible with volume exclusion thickeners such as ASE and cellulosic offerings.