Preparation of polyisocyanate containing biuret group comprises mixing di- and/or polyisocyanate; water (vapor) as biuret-forming agent; optionally catalyst, in a mixing device and leading the obtained reaction mixture into a reactor

摘要

Preparation of polyisocyanate (I) containing biuret group comprises mixing di- and/or polyisocyanate; water and/or water vapor as biuret-forming agent; optionally catalyst under release of carbon dioxide, in a mixing device with an energy of at least 0.05x10 6> J/kg water (vapor) and leading the obtained reaction mixture into an reactor, in which the reaction mixture, water (vapor) and carbon dioxide are lead in direct or indirect current. An independent claim is also included for a device comprising at least one mixing device, in which around a circulation pump, in which isocyanate directly or unitely with catalyst, water (vapor), optionally inert gas led over inlets, where circulation cycle ends in a promoted product in a downstream cascaded agitating reactor with 2-10 agitated segments, and followed by at least one tranquillizing zone to gas-liquid separation.