摘要:
The present invention relates to a process for preparing polyisocyanates from natural raw material sources, in which a composition comprising low molecular weight aromatics which comprise at least one hydroxy group or at least one alkoxy group per molecule (oxyaromatics) is produced from a biomass material, these oxyaromatics are converted into the corresponding aromatic amines and, optionally after condensation with formaldehyde, reacted further with phosgene to give compounds comprising isocyanate groups.
摘要:
Process for preparing aromatic isocyanates by reacting the corresponding formamides with an oxygen-comprising gas over noble metal catalysts at temperatures of from 300 to 600° C. and a contact time of from 1 to 1000 ms, wherein: a. the formamide is vaporized before entering the reaction zone, b. the reaction mixture obtained is quenched with an alcohol-comprising quenching liquid and c. the urethane formed is dissociated into isocyanate and alcohol.
摘要:
The present invention relates to a process for continuously preparing a mononitrated organic compound, especially a process for preparing mononitrobenzene. The invention relates more particularly to an improved continuous adiabatic process for preparing nitrobenzene.
摘要:
Process for preparing aromatic isocyanates by reacting the corresponding formamides with an oxygen-comprising gas over noble metal catalysts at temperatures of from 300 to 600° C. and a contact time of from 1 to 1000 ms, wherein: a. the formamide is vaporized before entering the reaction zone, b. the reaction mixture obtained is quenched with an alcohol-comprising quenching liquid and c. the urethane formed is dissociated into isocyanate and alcohol.
摘要:
The invention relates to a process for purifying crude aromatic nitro compounds which originate from the nitration of aromatic compounds, comprising the single or multiple performance of the following wash stage (a):(a) contacting the crude aromatic nitro compound (N-in) with an aqueous phase (W-res) and then separating the phases to obtain an organic phase (N-res) and an aqueous phase (W-res),wherein at least one demulsifier (D) is present in one or more of the wash stages (a).
摘要:
The invention relates to a process for the preparation of formamides by reacting aromatic amines with a formic acid ester in the presence of a catalyst, wherein the catalyst is a phosphorus-containing acid or a Lewis-acidic metal salt.
摘要:
The present invention relates to a process for preparing polyisocyanates comprising biuret groups from diisocyanates or polyisocyanates and diamines.
摘要:
The present invention relates to a process for preparing polyisocyanates from natural raw material sources, in which a composition comprising low molecular weight aromatics which comprise at least one hydroxy group or at least one alkoxy group per molecule (oxyaromatics) is produced from a biomass material, these oxyaromatics are converted into the corresponding aromatic amines and, optionally after condensation with formaldehyde, reacted further with phosgene to give compounds comprising isocyanate groups.
摘要:
The invention relates to a process for purifying crude aromatic nitro compounds which originate from the nitration of aromatic compounds, comprising the single or multiple performance of the following wash stage (a): (a) contacting the crude aromatic nitro compound (N-in) with an aqueous phase (W-res) and then separating the phases to obtain an organic phase (N-res) and an aqueous phase (W-res), wherein at least one demulsifier (D) is present in one or more of the wash stages (a).
摘要:
The present invention relates to a process for preparing polyisocyanates comprising biuret groups from diisocyanates or polyisocyanates and diamines.