abstract |
The present invention relates to a process for the preparation of a modified 1,5-naphthylene diisocyanate containing urea and biuret groups comprising reacting (a) 1,5-naphthylene diisocyanate in molten form with (b) a mixture comprising about 0.02 to about 0.5 mole of water per mole of 1,5-naphthylene diisocyanate and about 1 to about 10 parts for each part of water of an organic solvent. The present invention further relates to a process for the preparation of elastomeric moldings comprising reacting by the one-shot or prepolymer process at an isocyanate index of 70 to 130 a modified 1,5-naphthylene diisocyanate containing urea and biuret groups with compounds containing at least two isocyanate-reactive groups and having a molecular weight in the range from about 500 to about 10,000 and, optionally, organic compounds containing isocyanate-reactive groups and having a molecular weight in the range from 60 to 499. |