GREASE COMPOSITIONS HAVING POLYUREA THICKENERS MADE WITH ISOCYANATE TERMINATED PREPOLYMERS

摘要

This disclosure relates to grease compositions having at least one base oil, and at least one polyurea thickener. The at least one polyurea thickener is prepared by reacting an isocyanate- terminated prepolymer with at least one amine under reaction conditions sufficient to prepare the at least one polyurea thickener. The isocyanate-terminated prepolymer is prepared by reacting a polyisocyanate with a polyol, at an NCO/OH equivalent ratio of 1.05:1 to 10:1, under reaction conditions sufficient to prepare said isocyanate-terminated prepolymer. When the grease compositions are used under high temperature conditions, structural stability and resistance to breaking down in accordance with DIN 51821 (FAG FE9) is improved. This disclosure also relates to a method of preparing the grease compositions. This disclosure further relates to a method for improving high temperature performance of a grease composition in a mechanical component lubricated with the grease composition.