Modified polyisocyanates, a process for their production and their use

Modified polyisocyanates having an NCO group content of from 10 to 45% by weight, comprising

• a) a polyisocyanate component consisting essentially of an organic polyisocyanate having an NCO group content of from 15 to 50% by weight which is liquid at room temperature, and
• b) 2 to 100% by weight, based on the weight of component a), of a polymer modifier consisting of at least one particulate graft rubber which is dispersed in swollen from in component a), said modifier consisting of
• i) from 20 to 80% by weight of a rubber polymer having a glass transition temperature below 0.degree. C., and
• ii) from 20 to 80% by weight of vinyl monomers which have been grafted onto the rubber, wherein the weights of components b) i) and b) ii) total 100% of the weight of component b).