| 摘要 |
PROBLEM TO BE SOLVED: To provide a production method which can obtain a blocked isocyanate compound having a uretoneimine bond in the molecule which more reduces heating loss than conventional block isocyanate compounds by a simple method. SOLUTION: The method for producing a blocked isocyanate having a uretoneimine bond by carbodiimidating 4,4'-diphenyl-methane diisocyanate, then uretoneiminating the resulting compound to form a polyisocyanate, and blocking the resulting polyisocyanate with an active hydrogen compound comprises conducting the above carbodiimidation until the amount of the isocyanate group of 4,4'-diphenylmethane diisocyanate comes to 2/3 of its initial amount and, simultaneously, the above amount of the isocyanate group being 3.2-4.2 mmol/g.
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