摘要:
The invention relates to a process for isolating methylglycinenitrile-N,N-diacetonitrile (MGDN) from an aqueous emulsion which comprises MGDN and has an MGDN content of 3-50% by weight in a crystallizer, comprising the steps: (a) the aqueous emulsion is, starting from a temperature above the solidification point, cooled to a temperature below the solidification point, the cooling rate averaged over time not exceeding 5 K/h, until substantially the entirety of the emulsified MGDN has solidified, (b) the resulting aqueous suspension is cooled further and/or concentrated, and the cooling rate may be greater than in step (a).
摘要:
The invention relates to a process for isolating methylglycinenitrile-N,N-diacetonitrile (MGDN) from an aqueous emulsion which comprises MGDN and has an MGDN content of 3-50% by weight in a crystallizer, comprising the steps: (a) the aqueous emulsion is, starting from a temperature above the solidification point, cooled to a temperature below the solidification point, the cooling rate averaged over time not exceeding 5 K/h, until substantially the entirety of the emulsified MGDN has solidified, (b) the resulting aqueous suspension is cooled further and/or concentrated, and the cooling rate may be greater than in step (a).
摘要:
A method for isolating methylglycinenitrile-N,N-diacetonitrile (MGDN) from an aqueous mixture comprising MGDN is provided The method comprises cooling the aqueous mixture in one or more steps In one of these steps the mixture is cooled at a cooling rate of at least 20 K/h from a temperature above the solidification point of MGDN to a temperature below the solidification point of MGDN The method is implemented continuously
摘要:
The present invention relates to a process for preparing aminopolycarboxylates proceeding from an amino acid which, in a first process step is reacted with ethylene oxide to give an intermediate mixture comprising the corresponding dialkanolamine, and then the intermediate mixture, in a second process step is converted catalytically using a base to the corresponding aminopolycarboxylate, wherein the amino acid, before the reaction with ethylene oxide in the first process step, is supplied to a partial neutralization with 0.70 to 0.99 equivalent of base per acid group, or, in the first process step, an amino acid which has already been partly neutralized with 0.70 to 0.99 equivalent of base per acid group is used.
摘要:
Process for preparing one or more complexing agents selected from methylglycinediacetic acid, glutamic acid diacetic acid and salts thereofProcess for preparing one or more complexing agents selected from methylglycinediacetic acid, glutamic acid diacetic acid and salts thereof by catalytic dehydrogenation of N,N-bis(2-hydroxyethyl)alanine and/or N,N-bis(2-hydroxyethyl)glutamic acid and/or salts thereof in the presence of alkali metal hydroxide, where a catalyst comprising copper and zirconium dioxide is used, the activation of which is a reduction, wherein the precursor of the catalyst in question has a degree of crystallization K, defined as K = I K · 100 I K + I A , in the range from 0 to 50%.
摘要:
The present invention relates to a process for preparing aminopolycarboxylates proceeding from an amino acid which, in a first process step is reacted with ethylene oxide to give an intermediate mixture comprising the corresponding dialkanolamine, and then the intermediate mixture, in a second process step is converted catalytically using a base to the corresponding aminopolycarboxylate, wherein the amino acid, before the reaction with ethylene oxide in the first process step, is supplied to a partial neutralization with 0.70 to 0.99 equivalent of base per acid group, or, in the first process step, an amino acid which has already been partly neutralized with 0.70 to 0.99 equivalent of base per acid group is used.
摘要:
The invention relates to a process for preparing triethylenetetramine substituted by at least one methyl group (Me-TETA or methyl-substituted TETA compounds). Me-TETA is prepared by hydrogenating biscyanomethylimidazolidine (BCMI) in the presence of a catalyst. The present invention further relates to methyl-substituted TETA compounds as such. The present invention further relates to the use of methyl-substituted TETA compounds as a reactant or intermediate in the production of, for example, coatings or adhesives.
摘要:
The present invention relates to a process for preparing quaternary ammonium compounds, which comprises reacting compounds comprising an sp3-hybridized nitrogen atom with a dialkyl sulfate or trialkyl phosphate and subjecting the resulting ammonium compound to an anion exchange.
摘要:
The present invention relates to a method for the production of aminodicarboxylic acid-N,N,diacetic acids of the general Formula I, wherein X independently of one another represents hydrogen or an alkali metal and n represents a number 1 or 2. Furthermore, the invention relates to aminodicarboxylic acid-N,N-diacetic acids of high purity. The inventive method comprises the following steps: A.) reacting an aminodicarboxylic acid of the general Formula II, wherein X and n have the aforementioned meanings, with 0.8 to 1.2 mole equivalents of formaldehyde and with 0.8 to 1.2 mole equivalents of hydrocyanic acid; b) reacting the reaction products of step a) with 0.8 to 1.2 mole equivalents of hydrocyanic acid and with 0.8 to 1.2 mole equivalents of formaldehyde; c) hydrolyzing in the reaction product obtained in step b).
摘要:
Crystalline ascorbate, in particular choline ascorbate in the form of crystals free from water of crystallization, processes for its preparation, and its used are described.