Oligomeric Phosphonates for Universal Applications in Wash- and Cleaning Detergents

The properties of a new class of oligomeric phosphonates (HYDRODIS) for the usage in washing and cleaning detergents were studied. HYDRODIS integrates the dispersion capability of polymers and the exceptionable substoichiometrical sequestrant efficiency of this kind of phosphonates (threshold effect) in one molecule. The investigations were focused on the following items: • Measurement of the calcium sensitivity in comparison to classical sequestrants • Proofing the resolving of scale deposit • Visualization of the crystal growth by means of atomic force microscopy • Performance comparison in automatic dishwashing (substitution of NTA). It has been shown that the new molecule structure of those phosphonates provides additional performance-enhancing properties. In comparison to the other kind of classical sequestrants and dispersants HYDRODIS performs better particularly under difficult conditions as high p H , high temperatures and very high water hardness. As a very important aspect it has been proved that HYDRODIS develops no calcium sensitivity. Therefore no risk of precipitations exists by the inhibitor itself which usually occur in defined ranges of concentrations between calcium ions and the used inhibitor (= calcium sensitivity) - a very important aspect of security in cases of difficult or changeable conditions of water hardness. Over this HYDRODIS is able to resolve the existing scale deposit by a longer time of contact.