EPAISSISSANT THERMIQUEMENT STABLE

摘要

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.