Polyisocyanates

Polyisocyanates are prepared by a process which comprises(i) preparation of an addition product (A) which contains one group which is reactive toward isocyanate and one isocyanate group by reacting(a) a diisocyanate I with(b) compounds containing two groups which are reactive toward isocyanate, where at least one of the components (a) or (b) has functional groups having differing reactivities toward the functional groups of the other component,(ii) if desired, intermolecular addition reaction of the addition product (A) to form a polyaddition product (P) which contains one group which is reactive toward isocyanate and one isocyanate group and(iii) reaction of the addition product (A) and/or the polyaddition product (P) with a diisocyanate or polyisocyanate II which is different from diisocyanate I.