Abstract: The invention relates to a process for preparing methylenediphenyl diisocyanates which comprises at least the steps: A) reaction of aniline with formaldehyde in the presence of hydrochloric acid as catalyst to give a mixture of diamines and polyamines of the diphenylmethane series (MDA) and subsequent at least partial neutralization of the hydrochloric acid by means of alkali metal hydroxide, B) reaction of the mixture of diamines and polyamines of the diphenylmethane series obtained in step A) with phosgene to give a mixture of diisocyanates and polyisocyanates of the diphenylmethane series (MDI) and hydrogen chloride, wherein C) the hydrochloric acid which has been neutralized in step A) is separated off in the form of a solution containing alkali metal chloride and is subsequently at least partly fed to an electrochemical oxidation to form chlorine, alkali metal hydroxide and optionally hydrogen and D) at least part of the chlorine produced in step C) is used for preparing the phosgene used in step B).

Abstract: The invention relates to a process for preparing methylenediphenyl diisocyanates which comprises at least the steps: A) reaction of aniline with formaldehyde in the presence of hydrochloric acid as catalyst to give a mixture of diamines and polyamines of the diphenylmethane series (MDA) and subsequent at least partial neutralization of the hydrochloric acid by means of alkali metal hydroxide, B) reaction of the mixture of diamines and polyamines of the diphenylmethane series obtained in step A) with phosgene to give a mixture of diisocyanates and polyisocyanates of the diphenylmethane series (MDI) and hydrogen chloride, wherein C) the hydrochloric acid which has been neutralized in step A) is separated off in the form of a solution containing alkali metal chloride and is subsequently at least partly fed to an electrochemical oxidation to form chlorine, alkali metal hydroxide and optionally hydrogen and D) at least part of the chlorine produced in step C) is used for preparing the phosgene used in step B).

Abstract: The present invention relates to a process for the manufacture of diisocyanates by phosgenation of the corresponding diamines in which the vaporous diamines, optionally rarefied with an inert gas or with the vapors of an inert solvent, and phosgene are heated separately to temperatures of about 200° C. to about 600° C. and mixed and reacted in a tube reactor characterized in that a number n?2 of nozzles directed parallel to the axis of the tube reactor are arranged in the tube reactor, the diamine-containing stream being fed into the tube reactor through the n nozzles and the phosgene stream being fed into the tube reactor through the remaining free space.

Abstract: Mold release agents useful for the production of plastic molded parts having reduced concentration of undesirable, potentially health hazardous substances in the edge zone and on the surface of the molded part and a process for the production of low toxicity plastic molded parts using such mold release agents. These mold release agents have at least one group which is reactive with the undesirable materials that form on the surfaces and in the edge zones of the molded parts.

Abstract: The present invention relates to a process for the manufacture of diisocyanates by phosgenation of the corresponding diamines in which the vaporous diamines, optionally rarefied with an inert gas or with the vapors of an inert solvent, and phosgene are heated separately to temperatures of about 200° C. to about 600° C. and mixed and reacted in a tube reactor characterized in that a number n≧2 of nozzles directed parallel to the axis of the tube reactor are arranged in the tube reactor, the diamine-containing stream being fed into the tube reactor through the n nozzles and the phosgene stream being fed into the tube reactor through the remaining free space.

Abstract: Mold release agents useful for the production of plastic molded parts having reduced concentration of undesirable, potentially health hazardous substances in the edge zone and on the surface of the molded part and a process for the production of low toxicity plastic molded parts using such mold release agents. These mold release agents have at least one group which is reactive with the undesirable materials that form on the surfaces and in the edge zones of the molded parts.

Abstract: Cyclic products are prepared by selective olefin metathesis of bifunctional or polyfunctional substrates in the presence of one or several homogeneous or heterogeneous metathesis catalysts in a reaction medium. The invention is characterized in that the substrates contain two or more functional groups in the form of substituted or non-substituted alkene or alkyne units and in that the reaction medium essentially consists of compressed carbon dioxide. Also disclosed is the preparation of cyclic or polymer products according to the disclosed process, the reaction temperature and total pressure being matched to ensure that the density of the reaction medium lies in a range d=0.2-1.5 g·cm−3 and that the product distribution is essentially controlled by the reaction medium density.