abstract |
PROBLEM TO BE SOLVED: To find a method for producing a thixotropic agent having a well-defined structure, and to make it possible to stably store a solution obtained by such a method for several months or more. Further enhance the reliability of use of the solution. SOLUTION: A monohydroxyl compound is reacted with an excess of toluylene diisocyanate to remove unreacted toluylene diisocyanate, and the obtained monoisocyanate adduct is further reacted with a diamine in the presence of a lithium salt to produce urea. A solution containing urethane is produced. |