Abstract: A water dispersible, modified polyurethane which is the reaction product of polyisocyanate, polyether polyol, modifying agent containing at least one pendant hydrophobic group and at least two active hydrogen moieties and capping agent. The modified polyurethane may also include a second type of modifying agent which does not have a pendant hydrophobic group. The modified polyurethane can be prepared by reacting the polyisocyanate and the polyether polyol and then adding the capping agent and finally the modifying agent with or without the second modifying agent. The modified polyurethane resists microbial attack, exhibits superior efficiency in thickening aqueous compositions under high shear conditions and achieves acceptable sag and leveling.

Abstract: A water dispersible, modified polyurethane which is the reaction product of polyisocyanate, polyether polyol, modifying agent containing at least two active hydrogen moieties and capping agent. The modified polyurethane is preferably prepared by reacting the polyisocyanate, the polyether polyol and the modifying agent and then adding the capping agent. The modified polyurethane resists microbial attack, exhibits superior efficiency in thickening aqueous compositions and imparts improved leveling.Included among the modifying agents are ethylene diamine, 1,6-diaminohexane, 1,10-diaminodecane, N-phenyl-p-phenylenediamine, succinic acid, suberic acid, sebacic acid, 1,10-decanedicarboxylic acid, 1,4-benzene-dicarboxylic acid, ethanolamine, 2-(ethylamino)ethanol, and p-carboxyphenol and mixtures thereof.

Abstract: A thermally stable thickener is composed of a stabilizing agent and a water dispersible polyurethane. The stabilizing agent is a smectite-type clay having a cation exchange capacity of at least 75 milliequivalents per 100 grams of clay, 100% active clay basis. The water dispersible polyurethane must possess the property that it forms an aqueous composition that experiences a decrease in Stormer viscosity upon thermal aging. Aqueous compositions incorporating the thermally stable thickener may be exposed to extended periods at elevated temperatures without substantially affecting the level of thickening.