摘要:
The present invention relates to a process for preparing polyoxyalkylene glycol of high purity and having a low color number from the corresponding alkylene glycol and a starter in the presence of a basic catalyst, wherein a reducing agent is present in the polymerization.
摘要:
A process is described for purifying polyalkylene glycols obtained by adding alkylene oxide to alkylene glycol, in which, after addition is complete, the resultant polyalkylene glycol is treated at a pH of >7 with a bleaching agent selected from the group consisting of peroxides, peracids, percarbonates, perborates, peroxodisulfates or oxygen, in each case with or without addition of a bleaching activator. The process is suitable in particular for preparing polyethylene glycol having molar weights from 196 to 203 g/mol which meets requirements of pharmacopeias.
摘要:
A process is described for purifying polyalkylene glycols obtained by adding alkylene oxide to alkylene glycol, in which, after addition is complete, the resultant polyalkylene glycol is treated at a pH of >7 with a bleaching agent selected from the group consisting of peroxides, peracids, percarbonates, perborates, peroxodisulfates or oxygen, in each case with or without addition of a bleaching activator.The process is suitable in particular for preparing polyethylene glycol having molar weights from 196 to 203 g/mol which meets requirements of pharmacopeias.
摘要:
The present application relates to the use of formulations comprising a) at least one polymer as component A comprising at least one structural unit of the formula (I) where the structural unit may be part of a polymer main chain or may be bonded to a polymer main chain via an anchor group, and M is hydrogen or a metal cation; and water; for the treatment of hard surfaces as compositions for improving the run-off behavior of water from the treated hard surfaces and for reducing soil and salt deposition on the treated hard surfaces, and to formulations for the treatment of hard surfaces comprising the at least one polymer, at least one surfactant and at least one carboxylic acid and/or sulfonic acid and/or inorganic acid, and to the use of these formulations for the treatment of hard surfaces.
摘要:
The invention relates to a process for preparing substituted chroman derivatives of the general formula VII, ##STR1## where X is the group --CN, --COOR.sup.3, --CHO, --CH.sub.2 OR.sup.7 or --CH(OR.sup.8).sub.2,R.sup.2 is a C.sub.1 -C.sub.23 -alkyl, C.sub.2 -C.sub.23 -alkenyl, C.sub.6 -C.sub.18 -aryl or C.sub.7 -C.sub.18 -aralkyl radical,R.sup.3 is hydrogen or an optionally substituted C.sub.1 -C.sub.4 -alkyl radical,R.sup.4, R.sup.5, R.sup.6 are, independently of one another, hydrogen or a C.sub.1 -C.sub.4 -alkyl radical,R.sup.7 is hydrogen or a C.sub.1 -C.sub.4 -alkyl radical,R.sup.8 is a C.sub.1 -C.sub.4 -alkyl radical, or the two radicals are a C.sub.2 -C.sub.6 -alkylene radical which links the two oxygen atoms to form a cyclic acetal and is optionally branched or may carry one or two carboxyl groups, cyclohexyl or phenyl radicals,and to the novel intermediates of the process.
摘要:
The present application relates to the use of formulations comprising a) at least one polymer as component A comprising at least one structural unit of the formula (I) where the structural unit may be part of a polymer main chain or may be bonded to a polymer main chain via an anchor group, and M is hydrogen or a metal cation; and water; for the treatment of hard surfaces as compositions for improving the run-off behavior of water from the treated hard surfaces and for reducing soil and salt deposition on the treated hard surfaces, and to formulations for the treatment of hard surfaces comprising the at least one polymer, at least one surfactant and at least one carboxylic acid and/or sulfonic acid and/or inorganic acid, and to the use of these formulations for the treatment of hard surfaces.
摘要:
Process for isolating pure substances from of mixtures of high-boiling air- and/or temperature-sensitive substances which require a high separation efficiency, by rectification under medium vacuum in columns containing metal cloth packings with ordered structure using channel liquid distributors with 500 or more drip points/m.sup.2, which are arranged at an angle of 90.degree. to the cloth layers of the packing elements located immediately below the distributors, in which two or more of the packing elements underneath the liquid distributors have only a very small height, which ensure virtual exclusion of air and are designed so that no heat exchange through the column wall can take place during the rectification. The patent also relates to packed columns which can be used for this process and to the use of this process and these columns for the final purification of vitamin E acetate by distillation.
摘要:
A process for preparing chromanol derivatives of the formula I ##STR1## where n is from 1 to 10,R.sup.1, R.sup.2,R.sup.3, R.sup.4 independently of one another are hydrogen or C.sub.1 -C.sub.4 alkyl,R.sup.5 is hydrogen, C.sub.1 -C.sub.4 alkyl, C.sub.6 -C.sub.10 aryl, C.sub.7 -C.sub.18 aralkyl, C.sub.7 -C.sub.18 alkylaryl, C.sub.1 -C.sub.22 acyl, or a group protecting the hydroxyl,by reduction of the corresponding 4-oxochromanol derivatives of the formula II ##STR2## comprises reacting the 4-oxochromanol derivatives of the formula II with metallic zinc in the presence of an acid or an acid mixture.Compounds of the formula I having C.sub.1 -C.sub.22 acyl as radical R.sup.5 can also be prepared by the above-described reduction of the compounds of the formula II with hydrogen as radical R.sup.5 and simultaneous or subsequent esterification.
摘要:
Packing elements with a low pressure drop for mass transfer column internals of the internal diameter of the column and of a height of from 40 to 300 mm made of dimensionally stable layers, which have an ordered structure and are in mutual contact, of cloth material or cloth-like material with a specific surface area of from 100 to 2000 m.sup.2 /m.sup.3, whereina) the shaped layers of cloth material or cloth-like material, preferably made of metal cloth, which are in mutual contact are arranged so that they form a multiplicity of narrow flow channels, preferably virtually triangular, virtually rectangular or else virtually equilateral hexagonal flow channels, in which the angle of inclination of the serration of the individual cloth layers of the packing to the column axis is only 0 to 25.degree., preferably 3 to 14.degree., andb) to ensure mechanical stability of the packing elements, if necessary wires or thin rods are fixed in suitable arrangement between the cloth layers, or else the cloth layers are firmly connected at some points of contact, and processes for obtaining pure substances from substance mixtures by rectification using the novel packing elements.
摘要:
The invention relates to a process for preparing low-by-product, light-color methylglycine-N,N-diacetic acid tri(alkali metal) salt by alkaline hydrolysis of methylglycinediacetonitrile (MGDN), comprising the steps in the sequence (a) to (f): (a) mixing of MGDN with aqueous alkali at a temperature of ≦30° C.; (b) allowing the aqueous alkaline MGDN suspension to react at a temperature in the range from 10 to 30° C. over a period of from 0.1 to 10 h to form a solution; (c) allowing the solution from step (b) to react at a temperature in the range from 30 to 40° C. over a period of from 0.1 to 10 h; (d) optionally allowing the solution from step (c) to react at a temperature in the range from 50 to 80° C. over a period of from 0.5 to 2 h; (e) optionally allowing the solution from step (c) or (d) to react at a temperature in the range from 110 to 200° C. over a period of from 5 to 60 min; (f) hydrolysis and removal of ammonia of the solution obtained in step (c), (d) or (e) by stripping at a temperature of from 90 to 105° C.