摘要:
Process for distillatively separating a mixture containing a vinyl ether of the general formula (I) R1—O—CH═CH2 (I) and alcohol of the general formula (II) R2—OH (II) in which R1 and R2 are each independently a saturated or unsaturated, aliphatic or cycloaliphatic radical having from 2 to 10 carbon atoms, and in which the alcohol (II) has a boiling point which is at least 1° C. higher, measured at or extrapolated to 0.1 MPa abs, than the vinyl ether (I), by a) passing the mixture into a first distillation column and withdrawing, as a top product, an azeotrope containing vinyl ether (I) and alcohol (II) and, as a bottom product, a stream enriched with the alcohol (II); b) passing the azeotrope containing vinyl ether (I) and alcohol (II) from the first distillation column into a second distillation column which is operated at a pressure which is from 0.01 to 3 MPa higher compared to the first distillation column, and withdrawing, as a bottom product or gaseous sidestream in the stripping section, the vinyl ether (I) and, as a top product, an azeotrope containing vinyl ether (I) and alcohol (II); and c) recycling the azeotrope containing vinyl ether (I) and alcohol (II) from the second distillation column into the first distillation column.
摘要:
The present invention relates to a method of regenerating a ruthenium catalyst for the hydrogenation of phthalates, which comprises flushing the catalyst with inert gas in a regeneration step until the original activity or part of the original activity has been attained.
摘要:
The present invention relates to a process for preparing N-(1-alkenyl)carboxamides of the formula I, which comprises reacting a carboxamide of the formula II with an alkyne of the formula III in the presence of a catalyst selected from among carbonyl complexes, halides and oxides of rhenium, manganese, tungsten, molybdenum, chromium and iron.
摘要:
Processes comprising: providing a starting material comprising one or more aromatic hydrocarbons, and having an aromatic sulfur compound content and a total sulfur content; reducing the aromatic sulfur compound content and the total sulfur content in the starting material; and hydrogenating the one or more aromatic hydrocarbons in the presence of a supported ruthenium catalyst and hydrogen.
摘要:
In a process for preparing isocyanates by reacting the corresponding primary amines with phosgene in an inert solvent, use is made of from 0.01 to 50 mol % of a sulfonamide, based on the total amount of primary amine and isocyanate formed in the reaction solution.
摘要:
Process for distillatively separating a mixture containing a vinyl ether of the general formula (I) R1—O—CH═CH2 (I) and alcohol of the general formula (II) R2—OH (II) in which R1 and R2 are each independently a saturated or unsaturated, aliphatic or cycloaliphatic radical having from 2 to 10 carbon atoms, and in which the alcohol (II) has a boiling point which is at least 1° C. higher, measured at or extrapolated to 0.1 MPa abs, than the vinyl ether (I), by a) passing the mixture into a first distillation column and withdrawing, as a top product, an azeotrope containing vinyl ether (I) and alcohol (II) and, as a bottom product, a stream enriched with the alcohol (II); b) passing the azeotrope containing vinyl ether (I) and alcohol (II) from the first distillation column into a second distillation column which is operated at a pressure which is from 0.01 to 3 MPa higher compared to the first distillation column, and withdrawing, as a bottom product or gaseous sidestream in the stripping section, the vinyl ether (I) and, as a top product, an azeotrope containing vinyl ether (I) and alcohol (II); and c) recycling the azeotrope containing vinyl ether (I) and alcohol (II) from the second distillation column into the first distillation column.
摘要:
The invention relates to a process for the preparation of tetrasubstituted ureas by reaction of the corresponding amines with phosgene in the presence of an aqueous inorganic base at a temperature in the range from 0 to 150° C., which comprises: feeding the corresponding amine, the phosgene and the aqueous inorganic base on average continuously to the reaction apparatus, forming a two-phase system in the reaction apparatus through the choice of the tetrasubstituted ureas to be prepared, through the mixing ratios of the substances and substance mixtures to be fed in, through the temperature during the reaction and, where appropriate, through the feed of an organic solvent which is not completely miscible with water, and discharging the reaction mixture on average continuously from the reaction apparatus.
摘要:
The present invention relates to a process for continuously preparing 5-alkoxy-substituted oxazoles, in particular for continuously preparing 4-methyl-5-alkoxy-substituted oxazoles and also a process for preparing pyridoxine derivatives.
摘要:
A continuous process for preparing sugar alcohols by catalytic hydrogenation of an aqueous solution of a saccharide, which forms the corresponding sugar alcohol on hydrogenation, in the presence of a ruthenium catalyst which is obtainable by: i) single or multiple treatment of an amorphous silicon-dioxide-based support material with a halogen-free aqueous solution of a low-molecular-weight ruthenium compound and subsequent drying of the treated support material at below 200° C., ii) reducing the solid obtained in i) with hydrogen at from 100 to 350° C., step ii) being carried out immediately after step i), which comprises, before the hydrogenation, bringing the aqueous saccharide solution to be hydrogenated into contact with the support material.
摘要:
Polysiloxane sols preparable by subjecting (1) in a first stage (A) a silicon compound of the general formula I: (ZoL-)mSi(H)n(R)p (I), which is free of carbamate groups and where o is an integer from 1 to 5; m is 0, 1, 2 or 3; n is an integer from 1 to 4; p is 0, 1 , 2 or 3; Z is a reactive functional group, excluding carbamate group; L is an at least divalent, linking, organic group; H is a hydrolyzable, monovalent, organic group or hydrolyzable atom; R is a nonhydrolyzable, monovalent, organic group; to partial hydrolysis and condensation in the presence (B) of at least one crosslinking agent, and then subjecting (2) in a further stage, the reaction mixture (1) to complete hydrolysis and condensation with (C) a hydrolyzable, carbamate-functional silicon compound of the general formula II: {[HR1N—(O)C—O—]rL-}sSi(H)t(R)u (II) where R1 is a hydrogen atom or group R; r is an integer from 1 to 5; s is 1, 2 or 3; t is 1, 2 or 3; u 0, 1 or 2; and their use as coating materials, adhesives, and sealing compounds and also for producing optical moldings and self-supporting films.