Abstract:
Azo pigments of the Beta -hydroxynaphthoic acid series containing an o-phenylenediamine and a trimellitic acid imide moiety. These pigments are best illustrated by the formula
The pigments are suitable for example for coloring resins, surface coatings and printing inks and give brilliant hues of very good fastness properties.
Abstract:
PROBLEM TO BE SOLVED: To provide a method for producing an alkanolamine diminished in discoloration determined by e.g. APHA color number and improved in color stability over a long storage period. SOLUTION: This method for producing an alkanolamine comprises the following steps: step (a): the original alkanolamine is treated with an effective amount of phosphorous acid, hypophosphorous acid or a compound thereof at an elevated temperature for 5 min or longer, and subsequently, step b: the resultant alkanolamine is distilled in the presence of an effective amount of one of the above phosphorus compounds.
Abstract:
PROBLEM TO BE SOLVED: To find out an economical, selective and efficient method for producing an alkanolamine having improved color quality as opposed to a conventional method. SOLUTION: This method for producing the alkanolamine having the improved color quality and good in color stability comprises using a supported heterogeneous catalyst comprising a noble metal of Re, Ru, Rh, Pd, Os, Ir, Pt and/or Ag and a carrier material selected from the group of active carbon, α-aluminum oxide, zirconium dioxide and titanium dioxide as a hydrogenating catalyst in which the catalyst has a prescribed hardness of at least 10 N cutting hardness and prescribed strengths of at least 30 N laterial pressure strength and at least 25 N stamping strength in the case of active carbon as the carrier material in the method for producing the alkanolamine having the improved color quality by treating an alkanolamine using hydrogen at a high temperature in the presence of the hydrogenating catalyst. Thereby, the alkanolamine is economically produced.
Abstract:
The invention relates to a method for distillative separation of triethanolamin from a substance mixture consisting of mono- di-, and triethanolamin, ethanolamin-ether and water obtainable by an ammonia and ethylene oxide reaction in a liquid phase at a high pressure and temperature consisting in distilling the substance mixture in two stages. In the first stage, a low-boiling fraction and a high-boiling fraction are withdrawn and discharged, and in the second stage, a medium-boiling fractions is distilled at a triethanolamin content >99.4 % by weight and a diethanolamin content
Abstract:
Method of purifying triethanolamine prepared by reacting aqueous ammonia with ethylene oxide in the liquid phase under pressure and at elevated temperature by removing excess ammonia, water and monoethanolamine from the reaction product, reacting the resulting crude product with ethylene oxide at temperatures of from 110 to 180° C., and then rectifying the mixture in the presence of phosphorous or hypophosphorous acid or compounds thereof.
Abstract:
Process for separating triethanolamine continuously by distillation from a mixture of monoethanolamine, diethanolamine and triethanolamine together with ethanolamine ethers and water obtained by reaction of ammonia with ethylene oxide in the liquid phase under superatmospheric pressure and at elevated temperature, in which the mixture is distilled in two stages. The low-boiling fraction and the high-boiling fraction are taken off and discharged in the first stage and the intermediate-boiling fraction comprising >99.4% by weight of triethanolamine and
Abstract:
Process for separating triethanolamine continuously by distillation from a mixture of monoethanolamine, diethanolamine and triethanolamine together with ethanolamine ethers and water obtained by reaction of ammonia with ethylene oxide in the liquid phase under superatmospheric pressure and at elevated temperature, in which the mixture is distilled in two stages. The low-boiling fraction and the high-boiling fraction are taken off and discharged in the first stage and the intermediate-boiling fraction comprising >99.4% by weight of triethanolamine and
Abstract:
The invention relates to a method for distillative separation of triethanolamin from a substance mixture consisting of mono- di-, and triethanolamin, ethanolamin-ether and water obtainable by an ammonia and ethylene oxide reaction in a liquid phase at a high pressure and temperature consisting in distilling the substance mixture in two stages. In the first stage, a low-boiling fraction and a high-boiling fraction are withdrawn and discharged, and in the second stage, a medium-boiling fractions is distilled at a triethanolamin content >99.4 % by weight and a diethanolamin content
Abstract:
Process for separating triethanolamine continuously by distillation from a mixture of monoethanolamine, diethanolamine and triethanolamine together with ethanolamine ethers and water obtained by reaction of ammonia with ethylene oxide in the liquid phase under superatmospheric pressure and at elevated temperature, in which the mixture is distilled in two stages. The low-boiling fraction and the high-boiling fraction are taken off and discharged in the first stage and the intermediate-boiling fraction comprising >99.4% by weight of triethanolamine and
Abstract:
Process for separating triethanolamine continuously by distillation from a mixture of monoethanolamine, diethanolamine and triethanolamine together with ethanolamine ethers and water obtained by reaction of ammonia with ethylene oxide in the liquid phase under superatmospheric pressure and at elevated temperature, in which the mixture is distilled in two stages. The low-boiling fraction and the high-boiling fraction are taken off and discharged in the first stage and the intermediate-boiling fraction comprising >99.4% by weight of triethanolamine and