摘要:
Di- and polyamines of the diphenylmethane series are prepared by a) mixing a first portion of aniline with an acid catalyst, b) mixing a second portion of aniline with formaldehyde, and c) mixing and reacting the mixtures prepared in each of steps a) and b). The diamines produced by this process may then be phosgenated to produce the corresponding di-/polyisocyanate.
摘要:
Di- and polyamines of the diphenylmethane series are prepared by a) mixing a first portion of aniline with an acid catalyst, b) mixing a second portion of aniline with formaldehyde, and c) mixing and reacting the mixtures prepared in each of steps a) and b). The diamines produced by this process may then be phosgenated to produce the corresponding di-/polyisocyanate.
摘要:
The invention provides a process for the preparation of polyamines of the diphenylmethane series. This process comprises a) reacting aniline and formaldehyde in a molar ratio of 1.5:1 to 6:1, in the presence of an acid catalyst at temperatures of 20° C. to 100° C., in which the water content in the acid reaction mixture is
摘要:
The invention provides a process for the preparation of polyamines of the diphenylmethane series. This process comprises a) reacting aniline and formaldehyde in a molar ratio of 1.5:1 to 6:1, in the presence of an acid catalyst at temperatures of 20° C. to 100° C., in which the water content in the acid reaction mixture is
摘要:
The invention relates to a method of producing polyisocyanates of the diphenylmethane series including the steps of a) reacting aniline and formaldehyde in the presence of HCl to provide a product mixture containing polyamines of the diphenylmethane series, HCl, aniline and water; b) removing excess aniline and water by distillation to provide a product mixture comprising polyamines of the diphenylmethane series, HCl, no more than 10 wt. % aniline based on the polyamines, and no more than 5 wt. % water based on the polyamines; and c) phosgenating the product mixture in (b).
摘要:
Polyisocyanates of the diphenyl methane series having reduced color values are obtained by a) reacting aniline and formaldehyde in the presence of an acid catalyst to form a polyamine, b) neutralizing the reaction mixture containing polyamine with a base, c) separating the neutralized mixture into the aqueous and the organic phases, d) adding a base to the organic phase and then e) phosgenating the resulting polyamine to produce the corresponding polyisocyanate.
摘要:
Polyisocyanates of the diphenylmethane series are produced by a) reacting aniline and formaldehyde in the presence of an acidic catalyst to produce a polyamine, b) neutralizing the reaction mixture from step a) with a base at a temperature of more than 110° C. or neutralizing the reaction mixture from step a) with a base and heating the neutralized mixture to a temperature of more than 110° C., and c) phosgenating the polyamine from step b) to convert it to the corresponding polyisocyanate.
摘要:
The present invention relates to a host cell having an elevated expression or activity of an enzyme as compared with the parent cell from which it has been derived, said enzyme having lactoyl-CoA reductase activity. Furthermore, provided is a method of producing lactaldehyde and/or 1,2-propanediol, said method comprising culturing said host cell and/or utilizing said enzyme to produce said compound.
摘要:
A determination of an equivalent series resistance (ESR) effect for high frequency filtering performance of a filtered feed-through assembly is described. A low frequency signal is introduced to a filtered feed-through assembly. ESR limit of the filtered feed-through is determined based on the low frequency signal.
摘要:
The present invention relates to processes for the preparation of oxo products by the hydroformylation of substrates having C═C double bonds using unmodified rhodium catalysts in a reaction mixture essentially consisting of the substrates, the catalyst and carbon dioxide in a supercritical state (scCO2). In particular, the invention relates to such processes for the preparation of products which contain substantial proportions of branched i-oxo products. Further, the invention relates to such processes for the hydroformylation of substrates which do not correspond to the general formula CnH2n. The invention further relates to such processes in which the separation of product and catalyst is effected using the special solvent properties of scCO2.
摘要翻译:本发明涉及通过使用未改性的铑催化剂在基本上由底物,催化剂和超临界状态的二氧化碳(scCO2)组成的反应混合物中,通过使用C = C双键加成甲基化制备羰基合成产物的方法。 特别地,本发明涉及制备含有相当比例的支链α-氧代产物的产物的这种方法。 此外,本发明涉及用于不对应于通式C n H 2n的底物的加氢甲酰化的这种方法。 本发明还涉及使用scCO 2的特殊溶剂性质来分离产物和催化剂的方法。