| 摘要 |
The polyisocyanate ester compound is a branched material having at least two ester linkages, at least four urethane linkages further from the center of the compound compared to the ester linkages, and at least one terminal isocyanate group for each urethane linkage, which isocyanate group may be blocked. The compound can be prepared by first by reacting a polyol compound having at least two hydroxyl groups with a carboxylic acid compound having one carboxylic acid group and at least two hydroxyl groups to form a hydroxyl-functional ester product. The hydroxyl-functional ester product is then reacted with a polyisocyanate compound in which the isocyanate groups have different reactivities. The reaction with the polyisocyanate compound is carried out under conditions so that only one of the isocyanate groups is substantially reactive with the hydroxyl groups of the ester product of the first stage.
|
