Process for producing low-monomer-content organic polyisocyanates

A process for producing polyisocyanates having a residual monomeric isocyanate content of less than 1.0% by weight, comprising:

• 1) reacting
• A) an isocyanate component composed of at least 60% by weight of one or more diisocyanates and not more than 40% by weight of one or more monoisocyanates and/or one or more isocyanates having a functionality ≧3 with
• B1) optionally a catalyst and/or
• B2) optionally a reactive component
• in the form of droplets in a diluent C) at a temperature of 0 to 200° C. with oligomerization,
• 2) separating the reaction mixture into an isocyanate phase and a diluent phase;
• 3) optionally adding a catalyst poison D) before, during or after the phase separation;
• and
• 4) removing the polyisocyanate present in the isocyanate phase from the excess monomer.