摘要:
A reactor for the thermal cleavage of monofunctional and/or polyfunctional carbamic esters into the corresponding isocyanate and hydroxyl components in the liquid phase having devices for introduction of heat into the reactor, where the devices are heat exchanger plates through which a heat transfer medium flows and have a geometry defined by the ratio of the degassing area to the volume and arrangement of the heating surfaces which makes it possible for the cleavage to be carried out in a two-phase mixture which has a gas content of over 50% by volume.
摘要:
The invention provides a multistage process for continuously preparing organic, distillable polyisocyanates, preferably diisocyanates, more preferably aliphatic or cycloaliphatic diisocyanates, by reacting the corresponding organic polyamines with carbonic acid derivatives and alcohols to low molecular mass monomeric polyurethanes, and thermally cleaving said polyurethanes, in which at defined reaction stages the polyisocyanates prepared and unusable residues are separated off, and reusable by products and intermediates are recycled to upstream stages.
摘要:
The invention relates to a multistage process for the continuous preparation of organic, distillable isocyanates, preferably diisocyanates, particularly preferably aliphatic or cycloaliphatic diisocyanates, by reaction of the corresponding organic amines with urea and alcohols to liberate ammonia and form low molecular weight monomeric urethanes and thermal dissociation of the latter, in which by-products formed are at least partly utilized.
摘要:
The invention relates to a multistage process for the continuous preparation of organic, distillable isocyanates, preferably diisocyanates, particularly preferably aliphatic or cycloaliphatic diisocyanates, by reaction of the corresponding organic amines with urea and alcohols to liberate ammonia and form low molecular weight monomeric urethanes and thermal dissociation of the latter, in which by-products formed are at least partly utilized.
摘要:
The invention relates to an improved multistage process for the continuous preparation of diisocyanates by reaction of the corresponding diamines with carbonic acid derivatives and alcohols to form low molecular weight monomeric urethanes and thermal dissociation of the latter.
摘要:
The invention relates to an improved multistage process for the continuous preparation of diisocyanates by reaction of the corresponding diamines with carbonic acid derivatives and alcohols to form low molecular weight monomeric urethanes and thermal dissociation of the latter.
摘要:
The invention relates to a multistage process for the continuous preparation of organic, distillable polyisocyanates, preferably diisocyanates, particularly preferably aliphatic or cycloaliphatic diisocyanates, by reaction of the corresponding organic polyamines with carbonic acid derivatives and alcohols to form low molecular weight monomeric polyurethanes and thermal dissociation of the latter, in which the polyisocyanates produced and unusable residues are separated off at particular stages of the reaction and reusable by-products and intermediates are recirculated to preceding stages.
摘要:
The present invention relates to a multiple-stage process for the continuous preparation of organic, distillable polyisocyanates, preferably diisocyanates, more preferably aliphatic or cycloaliphatic diisocyanates, by reaction of the corresponding organic poly-amines with ureas to form low-molecular monomeric polyureas, and the thermal decomposition thereof.
摘要:
A process for preparing urethanes by reacting aromatic diamines with a dialkyl carbonate, wherein the alkyl radical of the organic dialkyl carbonate comprises 2-18 carbon atoms and one or more heteroatoms and the reaction is performed in the presence of a catalyst.