| 摘要 |
PROBLEM TO BE SOLVED: To provide a process for producing a urea grease in improved productivity and quality by replacing a secondary milling method by a method comprising comminuting urea thickener particles in the urea reaction stage. SOLUTION: A urea grease is produced by subjecting an isocyanate and an amine to a urea reaction in a mineral oil or a synthetic oil by means of a mill having a construction in which a plurality (say, 2) of agitating elements 2 being a plurality (say, 2) of blade-type agitating elements 2 deviating from the center of a treatment tank 1 and composed of vertically extending platy twisted plates are positioned, and a shearing-type mixing element 3 rotating at a speed higher than that of the element 2 in at least one position between the elements 2 and deviating from the center of the tank 1 is positioned, and the element 2 and the element 3 are rotated both around their respective axes and about the center of the tank. |
