Preparation of storage-stable, isocyanate-functional prepolymers using NCO-functional carbonyl and carbamoyl halides

Abstract

The invention relates to storage-stable isocyanate-functional prepolymers, to a process for the preparation, and also to their use as a starting component in the production of polyurethane plastics, of paints and coatings, of adhesives and of sealants.

Description

Claims

1. Isocyanate-functional prepolymers comprising at least one structural unit of the general formula (I) or (II)

2. Isocyanate-functional prepolymers according to claim 1, in which R and R′ are each an o-, m or p-phenylene radical, a 1,5-pentylene radical or a 2,4- or 2,6-toluene radical, R″ is a C1 to C4-alkyl radical and X is Cl.

3. Process for preparing isocyanate-functional prepolymers according to claim 1, comprising reacting: a) one or more polyisocyanates withb) one or more polyols in the presence ofc) at least one isocyanatocarbonyl halide or isocyanatocarbamoyl halide of the general formula (III) or (IV), respectively

4. Process according to claim 3, wherein R and R′ are each an o-, m or p-phenylene radical, a 1,5-pentylene radical or a 2,4- or 2,6-toluene radical, R″ is a C1 to C4-alkyl radical and X is Cl.

5. Process according to claim 3, wherein the polyisocyanates are selected from the group consisting of hexamethylene diisocyanate, isophorone diisocyanate, the isomeric bis(4,4′-isocyanatocyclohexyl)methanes, TDI, MDI, and mixtures thereof.

6. Process according to claim 3, wherein the polyols are polyether-based polyols.

7. Process according to claim 3, wherein the isocyanatocarbonyl halide is selected from the group consisting of 6-isocyanatocaproyl chloride, 11-isocyanatoundecanoyl chloride, and o-, m- or p-isocyanatobenzoyl chloride.

8. Process according to claim 3, wherein the isocyanatocarbamoyl halide is selected from the group consisting of 2-chlorocarbamoyl-ethylamino-4-isocyanatotoluene and 4-chlorocarbamoyl-ethylamino-2-isocyanatotoluene.

9. Process according to claim 3, wherein the equivalents ratio of the NCO groups of component a) to the OH groups of component b) is from 7:1 to 3:1.

10. Polyurethane compositions obtained from isocyanate-functional prepolymers according to claim 1.

11. Polyurethane compositions according to claim 10, wherein the compositions are selected from the group consisting of plastics, paints, coatings, adhesives or sealants.

12. Substrates provided with coatings obtained from isocyanate-functional prepolymers according to claim 1.