Abstract: The present invention relates to isocyanato-isocyanurates corresponding to the formula ##STR1## in which X.sub.1, X.sub.2 and X.sub.3 may be the same or different and represent radicals corresponding to the formula ##STR2## wherein R.sup.1 and R.sup.2 may be the same or different and represent hydrogen or C.sub.1 -C.sub.12 alkyl groups, and p is a whole or (on a statistical average) fractional number of from 1 to 5.The present invention also relates to a process for producing these isocyanato-isocyanurates and additionally relates to the use of the new isocyanato-isocyanurates, optionally blocked by blocking agents for isocyanate groups, as the isocyanate component in the produciton of isocyanate polyaddition products, preferably polyurethane lacquers.

Abstract: Polyisocyanates are prepared by reacting a polyamine solution with a phosgene solution. Excess phosgene and hydrogen chloride formed during the reaction are removed from the reaction mixture. The solvent is subsequently removed from the reaction mixture (e.g., by evaporation and condensation) and treated with a compound containing isocyanate reactive hydrogen atoms to convert any isocyanates present into urethanes and/or ureas. The thus-treated solvent may then be reused, preferably after any urethanes and/or ureas present in the solvent have been removed.