| abstract |
Abstract The present invention relates to a process for preparing hydrophobically modified alkylene oxide polyurethanes by polymerizing, in the presence of a catalyst, a solvent-free melt of a polyisocyanate branching agent; a water-soluble polyalkylene glycol having an M, of from 2000 5 to 11,000 Daltons; and a diisocyanate; wherein the solvent-free melt further includes a hydrophobic capping agent, or a hydrophobic capping agent is added to the melt after the addition of catalyst. Hydrophobically modified alkylene oxide polyurethanes prepared by the process of the present invention show excellent ICI/KU properties and are useful as thickeners for coatings formulations. |