WASSERDISPERGIERBARES HYBRIDPOLYMER

摘要

Proposed is a water-dispersible hybrid polymer comprising an ethylenically unsaturated polyurethane (core) onto which an addition polymer chain (shell) has been provided by polymerisation, with the unsaturation of the polyurethane being achieved by the incorporation therein of dimethyl-m-isopropenyl benzyl isocyanate, and the acid number of the shell polymer being in the range of 30 to 120 (mg KOH/g). Aqueous dispersions of these hybrid polymers are pre-eminently suitable for use in aqueous coating compositions of the so-called clear coat type, particularly when stringent demands are imposed with regard to the acid resistance of the topcoats applied using these compositions.