Patent ID: 9663607
Date: 2017-05-30
CPC Classifications: C08G,C09D

Claim:
1. A process for preparing an aqueous solution of a hydrophobically modified alkylene oxide poly(urethane-urea-allophanate) thickener consisting of the steps of: a) contacting under reactive conditions 1) a water-soluble polyalkylene glycol; 2) a hydrophobic capping agent or a hydrophobic difunctional agent or a combination thereof; and 3) a 2 to 50 percent stoichiometric excess of a diisocyanate with respect to the sum of the moles of isocyanate reactive groups of the polyalkylene glycol; and ii) the capping agent or the hydrophobic difunctional agent or a combination thereof, to form a polyurethane prepolymer with isocyanate functionality; then b) contacting the prepolymer with water under conditions sufficient to convert the prepolymer to an aqueous solution of a hydrophobically modified alkylene oxide poly(urethane-urea-allophanate).