Abstract:
A method for producing carbamate including a urea production step; a carbamate-forming step; an ammonia separation step of absorbing the gas with water in the presence of carbonate to produce a gas absorption water, and separating ammonia; an aqueous alcohol solution separation step of separating an aqueous alcohol solution from the gas absorption water; an ammonia/carbon dioxide separation step of separating carbon dioxide gas from the aqueous ammonia solution in the gas absorption water from which the aqueous alcohol solution is separated; an aqueous ammonia solution reusing step of mixing the aqueous ammonia solution and carbonate with the water to be used for production of the gas absorption water.
Abstract:
The present invention relates to gas phase phosgenation of amines for preparation of isocyanates. In the present invention, phosgene is prepared by reacting chlorine with an excess of carbon monoxide in a gas phase. The obtained phosgene-containing reaction mixture is divided into two streams by a thermal and/or a membrane separating process. The first stream is a low-carbon monoxide stream of no more than 1% by weight of carbon monoxide, based on a total weight of the first stream. The second stream is a carbon monoxide-rich stream of more than 10% by weight of carbon monoxide, based on a total weight of the second stream. The first stream is used as the phosgene-containing reactant stream in the gas phase phosgenation of amines to prepare isocyanates. The second stream can be recycled into the phosgene synthesis.
Abstract:
The invention relates to a process for preparing isocyanates by reacting the corresponding amines with phosgene, optionally in the presence of an inert medium, in which phosgene and amine are first mixed and converted to the isocyanate in a reactor, and in which a reaction gas which comprises isocyanate and hydrogen chloride leaving the reactor is cooled in a quench by adding a liquid quench medium to form a mixture of reaction gas and quench medium as the product stream. The walls of the quench are essentially completely wetted with a liquid.
Abstract:
A method for producing carbamate including a urea production step; a carbamate-forming step: an ammonia separation step of absorbing the gas with water in the presence of carbonate to produce a gas absorption water, and separating ammonia; an aqueous alcohol solution separation step of separating an aqueous alcohol solution from the gas absorption water; an ammonia/carbon dioxide separation step of separating carbon dioxide gas from the aqueous ammonia solution in the gas absorption water from which the aqueous alcohol solution is separated; an aqueous ammonia solution reusing step of mixing the aqueous ammonia solution and carbonate with the water to be used for production of the gas absorption water.
Abstract:
The invention relates to a process for preparing isocyanates by reacting the corresponding amines with phosgene in the gas phase, optionally in the presence of an inert medium, in which the amine is evaporated in an evaporator to give an amine-comprising gas stream, the phosgene is mixed into the amine-comprising gas stream, and the amine and the phosgene are converted to the isocyanate in a reactor, wherein the temperature of surfaces in contact with the gaseous amine is kept above the dew point limit of the amine-comprising gas stream. The invention further relates to an apparatus for preparing isocyanates by reacting the corresponding amines with phosgene in the gas phase, comprising an evaporator to evaporate the amine and a reactor in which the reaction is effected, and means of connection of evaporator and reactor, wherein surfaces which can come into contact with gaseous amine are provided with a coating which is not wetted by amine or have an averaged roughness depth Rz to DIN ISO 4287 of not more than 10 μm, and/or the apparatus has no dead spaces or thermal bridges.
Abstract translation:本发明涉及一种制备异氰酸酯的方法,该方法通过使气相中的相应胺与光气反应,任选地在惰性介质存在下进行,其中胺在蒸发器中蒸发得到含胺气流,光气 混合到含胺的气流中,并且胺和光气在反应器中转化为异氰酸酯,其中与气态胺接触的表面的温度保持在含胺的气流的露点极限以上 。 本发明还涉及一种用于通过使相应的胺与气相中的光气反应制备异氰酸酯的装置,其包括蒸发器以蒸发胺和其中进行反应的反应器,以及蒸发器和反应器的连接装置,其中表面 可以与气态胺接触的涂层提供有不被胺润湿或者具有DIN ISO 4287的平均粗糙深度Rz不大于10μm的涂层和/或该设备没有死空间或热桥。
Abstract:
The invention relates to a process for preparing isocyanates by reacting the corresponding amines with phosgene in the gas phase, optionally in the presence of an inert medium, in which the amine and the phosgene are first mixed and converted to the isocyanate in a reactor, and in which a reaction gas (1) which comprises isocyanate and hydrogen chloride leaving the reactor is cooled in a quench (3) by adding a liquid quench medium (5) to form a mixture of reaction gas and quench medium as the product stream (7). The quench medium (5) used is a mixture which comprises at least one solvent and isocyanate and which is withdrawn from the preparation process, any solid particles present in the quench medium (5) being removed before addition to the quench (3).
Abstract:
A polyisocyanate composition containing an amide-modified product, obtained by modifying a polyisocyanate compound with a polybasic carboxylic acid in an equivalent ratio of carboxyl groups/isocyanate groups being at most 0.9.
Abstract:
Aliphatic and/or cycloaliphatic polyisocyanates containing allophanate groups are produced by reacting (a) a di- and/or polyisocyanate with aliphatic and/or cycloaliphatic isocyanate groups with (b) a hydroxy compound at a temperature of at least 150.degree. C. for no more than 90 minutes and then rapidly cooling the reaction mixture to a temperature of less than 100.degree. C. It is preferred that the reaction be carried out in the absence of oxygen. The products thus obtained are virtually colorless, have a relatively low viscosity and excellent storage stability.
Abstract:
Disclosed are novel compositions capable of catalytically trimerizing organic isocyanates said compositions comprising solutions of the reaction products obtained by reacting in an inert solvent in substantially equimolar proportions electron-rich ketene-aminals with electron-poor olefins having the respective formulae (I) and (II) ##STR1## The variously substituted electron-rich ketene-aminals (I), as the name implies, have high electron density associated with the double bond because of the two tertiary amine groups while the electron-poor olefins (II) have the opposite situation due to the presence of electron withdrawing substituents R.sub.9 and R.sub.10.Also discosed is an improved process for trimerizing organic isocyanates using the above catalyst compositions including the preparation of polyisocyanurate polymers and isocyanurate-modified polyisocyanates.
Abstract:
This invention relates to compounds of the formula ##STR1## Z' is chlorine or fluorine, with the proviso that Z' is chlorine when Q is the moiety of Formula III. The invention also relates to the preparation of the compounds, their use in controlling animal pests in plant protection, and pesticidal agents comprising the compounds as active ingredients.