摘要:
The invention relates to an apparatus for the galvanic deposition of a metal layer on a substrate and comprises a substrate holder connected to a drive shaft that extends in a direction perpendicular to a surface of the substrate. The cathode current is supplied to the substrate by the drive shaft. The drive shaft has an outer insulating layer. The substrate is held in contact with a contact plate by a supporting ring on the outer periphery of a supporting plate. The contact plate rests on a base of the supporting plate and has a central sleeve connectable with the drive shaft. A mounting portion is provided in the base around the sleeve and a tube portion is inserted into the mounting portion in a sealing and detachable manner. An internally threaded ring is arranged on the drive shaft and is shiftable along the longitudinal axis of the drive shaft. The internally threaded ring is detachably connectable to the tube portion and seals the tube portion and the drive shaft from intrusion of the electrolyte material.
摘要:
A process for coproducing di- and/or polyisocyanates and glycols, comprising process stages A, B, C and E for preparing glycols and process stages A, C, D, E, F and G for preparing di- and/or polyisocyanates,which comprises accomplishing the material coupling via the separation of the reaction mixture obtained in process stage A into process stages B and C, by in process stage A, reacting an aqueous alkylene oxide with carbon dioxide to give a reaction mixture comprising alkylene carbonate, hydrolyzing a portion of the alkylene carbonate-comprising reaction mixture obtained in process stage A to glycol in process stage B, dewatering the remaining alkylene carbonate-comprising stream of the reaction mixture from process stage A in process stage C, in process stage D, synthesizing amine by hydrogenating an aromatic nitro compound or a nitrile, in process stage E, transesterifying the dewatered alkylene carbonate-comprising mixture from process stage C with a monohydroxy alcohol to give the corresponding dialkyl carbonate, obtaining glycol as a coproduct, in process stage F, reacting the dialkyl carbonate-comprising reaction mixture obtained in process stage E with the amine obtained in process stage D to a mixture comprising the corresponding mono-, di- and/or polycarbamate, which in process stage G is cleaved to obtain the corresponding di- and/or polyisocyanate.
摘要:
The invention relates to a process for preparing isocyanates by thermal dissociation of carbamates and separation by distillation of the reaction mixture from the carbamate dissociation, comprising the corresponding isocyanate and the corresponding alcohol, by distillation in a column (K) having an enrichment section (V) and a stripping section (A), where the carbamate (1) is introduced between the enrichment section (V) and the stripping section (A) and the isocyanate is taken off as a constituent of the bottom stream (2) and the alcohol is taken off as a constituent of the overhead stream (3) from the column (K), in the presence of an inert solvent, wherein an intermediate boiler having a boiling point between the boiling point of the isocyanate and the boiling point of the alcohol under the operating conditions of the carbamate dissociation is used as inert solvent and is fed as external runback (4) in liquid form in a purity of >95% by weight, based on the total weight of the external runback (4), in the upper region of the enrichment section (V) and as gaseous, superheated stream (5) into the lower region of stripping section (A) at one or more points.
摘要:
Process for preparing aromatic isocyanates by reacting the corresponding formamides with an oxygen-comprising gas over noble metal catalysts at temperatures of from 300 to 600° C. and a contact time of from 1 to 1000 ms, wherein: a. the formamide is vaporized before entering the reaction zone, b. the reaction mixture obtained is quenched with an alcohol-comprising quenching liquid and c. the urethane formed is dissociated into isocyanate and alcohol.
摘要:
The invention provides a process for preparing polyisocyanates, comprising the steps of a) reacting amines with phosgene, b) removing hydrogen chloride, excess phosgene and, if appropriate, the solvent from the reaction mixture, c) separating the liquid mixture from step b) into a liquid phase and a gaseous phase, d) working up the gaseous phase from step c) to give the polyisocyanate.
摘要:
A process for coproducing di- and/or polyisocyanates and glycols, comprising process stages A, B, C and E for preparing glycols and process stages A, C, D, E, F and G for preparing di- and/or polyisocyanates,which comprises accomplishing the material coupling via the separation of the reaction mixture obtained in process stage A into process stages B and C, by in process stage A, reacting an aqueous alkylene oxide with carbon dioxide to give a reaction mixture comprising alkylene carbonate, hydrolyzing a portion of the alkylene carbonate-comprising reaction mixture obtained in process stage A to glycol in process stage B, dewatering the remaining alkylene carbonate-comprising stream of the reaction mixture from process stage A in process stage C, in process stage D, synthesizing amine by hydrogenating an aromatic nitro compound or a nitrile, in process stage E, transesterifying the dewatered alkylene carbonate-comprising mixture from process stage C with a monohydroxy alcohol to give the corresponding dialkyl carbonate, obtaining glycol as a coproduct, in process stage F, reacting the dialkyl carbonate-comprising reaction mixture obtained in process stage E with the amine obtained in process stage D to a mixture comprising the corresponding mono-, di- and/or polycarbamate, which in process stage G is cleaved to obtain the corresponding di- and/or polyisocyanate.
摘要:
The invention relates to the fields of materials sciences and medicine and relates to an agent, which can be used, for example, as a contrast medium for the localization of cancer cells. The object of the present invention is to disclose an agent which sensitively and selectively recognizes the site and the type of the molecules or cells to be examined. The object is attained through an agent composed at least of bio-shuttle molecules to which endohedral fullerenes are coupled by way of peptide-based molecules, wherein the endohedral fullerenes are hydrophobic and correspond to the formula A3-xMxZ@C2n in which x=0 to 3 and n≧34, A means rare earths and/or transuranic elements, M means metals, Z means non-metals and C means carbon. The object is further attained through a method in which hydrophobic endohedral fullerenes are coupled with bio-shuttle molecules by way of an irreversible Diels-Alder reaction with an inverse electron demand (DARinv).
摘要:
The present invention relates to in-place soil stabilization. Specifically, the present invention relates a method and device for measuring the increase in subsurface earth pressure during the injection of a stabilizing agent into the soil. The rise in sensor pressure indicates an increase in soil strength and bearing capacity. Therefore, real-time monitoring of these pressures may serve as a guide during the injection process.
摘要:
A worm gear for a vehicle steering system. The worm gear includes a tooth worm and a tooth worm wheel which mesh with each other. The teeth on the worm wheel are shaped such that the pressure angle of the left tooth flank and the right tooth flank are different from each other so that the normal force between the worm and the worm wheel is independent of the direction of rotation of the torque exerted on the worm by the worm wheel.
摘要:
A rack oven includes a rack carrier with a main body ant at least one side support connected to the main body for movement between a rack holding position and a rack transfer position. The main body and side support form a rack receiving channel. The side support may be biased into one of the rack holding and the rack transfer positions.