| 摘要 |
<p>Disclosed is a novel polyisocyanate which is obtained by reacting at least one diisocyanate selected from the group consisting of an aliphatic diisocyanate and an alicyclic diisocyanate with a polyol having a number average molecular weight of from 3,000 to 30,000 and an average number of hydroxyl groups of from 2 to 3 and which contains allophanate linkages and urethane linkages in a specific ratio. The polyisocyanate of the present invention exhibits a high curing rate and a low viscosity. Further, the polyisocyanate, upon being cured, not only has no surface tack and exhibits a low modulus-in-tension property, but also exhibits a high tensile elongation property without a need for a plasticizer. Therefore, the polyisocyanate of the present invention can be advantageously used as a sealant. Also disclosed is a method for effectively and efficiently producing the polyisocyanate which, upon being cured, is improved with respect to a low modulus-in -tension property and a high tensile elongation property.</p> |
