Method for the preparation of graft polymer dispersions having broad particle size distribution without wildly fluctuating viscosities

摘要

A method for preparing graft polymer dispersions having broad particle size distribution without wildly fluctuating viscosities is disclosed. The method comprises: (a) preparing intermediate graft polyol dispersions containing 30 percent by weight or less solids to achieve a broad distribution of partial sizes in a continuous process and (b) charging the intermediate graft polymer dispersion of (a) to a semi-batch reactor as seeds for further grafting to increase the solids content of the dispersion to above 30 percent by weight. The graft polymer so formed is useful in the production of polyurethanes.