Abstract: A process for the concentration of aqueous hydrogen peroxide by discontinuous crystallization. A cooling surface is arranged in a crystallizing vessel and first wetted with hydrogen peroxide and then cooled at a high cooling rate, whereupon seed crystals form. The cooling rate is at least 1 K/s, preferably from 10 to 30 K/s. When the vessel has been filled with H2O2 starting material, the latter crystallizes, starting from the seed crystals, and forms a crystal layer. When the mother liquor of lower H2O2 concentration has been discharged, there follows a sweating operation with a slow increase in temperature, as a result of which the H2O2 concentration in the crystal layer is increased further.

Abstract: Strongly acid cation exchangers with improved properties are obtained if the sulphonation of the non-functionalized polymers is carried out at a high temperature and/or in the absence of oxygen.

Abstract: A method of manufacturing electronic or opto-electronic or micromechanic components by providing a vacuum where the external surface of a wall is exposed to ambient air and the inner surface enclosed as a processing area. A base body of a part to be manufactured is introduced into the processing area and a low energy plasma discharged is generated in the process area, the ion energy at the surface of the base body is between 0 and 15 eV in order to introduce a reactive gas. Subsequently, the reactive gas treats the base body in order to separate the processing area from an inner surface of the wall and enclosing the processing area during the treatment.

Abstract: Process for producing hydrogen peroxide The invention relates to a process for producing hydrogen peroxide by the cyclic anthraquinone process. According to the invention, the rate of oxidation of a hydrogenated working solution containing a tetrahydroanthrahydroquinone derivative is increased if the oxidation is carried out in the presence of a secondary amine. Preferably a slightly water-soluble secondary amine having a boiling point of at least 150° C., in a quantity of 0.001 to 2 mol per mol of tetrahydro compounds, is used.

Abstract: In carrying out the hydrogenation stage of the anthraquinone process for the preparation of hydrogen peroxide in a hydrogenation reactor on a fixed bed catalyst of a particulate catalyst, the service life of the catalyst is increased in that the working solution comprising the reaction carrier and a gas phase comprising hydrogen, are passed through the hydrogenation reactor from the bottom upwards. The empty tube speed of the working solution is 0.05 to 100 m/h, preferably 10 to 50 m/h.

Abstract: A freezer head for pipe freezing devices has a casing having a first exterior side with one or more first exterior depressions for receiving a pipe section to be frozen. The casing has a second exterior side with one or more second exterior depressions. The casing has a hollow interior. The casing has at least one connector configured to supply a cooling medium into the hollow interior. The first depression has a bottom having at least a first bottom portion and a second bottom portion, wherein each one of the first and second bottom portions has a different radius of curvature. The second depression has a bottom having at least a first bottom portion and a second bottom portion, wherein each one of the first and second bottom portions has a different radius of curvature.

Abstract: A vacuum arrangement with a vacuum disc valve. A support plate is movably guided along a wall with an opening that is closed or opened by a valve. A seal plate is provided on the support plate which is controlled and actuated through a cylinder chamber. When the support plate is moved, the seal plate is displaced in the direction of the opening and is tightly placed on the borders of said opening by actuation in the cylinder chamber. The resulting sealing forces are absorbed by the movement guides of the support plate.

Abstract: Pressing tongs have at least two pressing jaws wherein at least one of the pressing jaws is configured to be moved from a closed position into an open position. At least one first connector is provided to connect the pressing tongs to a motor-driven actuating device. At least one second connector is provided to connect the pressing tongs to a manual actuating device. The same type of pressing tongs can thus be operated manually as well as motor-driven.

Abstract: An electric tool for applying a pressing force has a tool housing and a drive arranged in the tool housing. The drive has an electric motor and a drive element configured to be driven by the electric motor. The drive element is located externally to the tool housing. A pressing unit is connected to the drive element remote from the tool housing and has two pressing parts. The drive element acts on at least one of the two pressing parts for moving the at least one pressing part relative to the other one of the two pressing parts. The drive element is preferably a hydraulically actuated piston, and the electric motor operates a pump element that supplies hydraulic medium to the piston.

Abstract: The present invention relates to a method for avoiding undesirable discoloration in polycarbonate production by catalytic removal of dissolved oxygen from phenol by (a) admixing hydrogen with phenol and (b) passing the phenol stream over ion exchangers doped with platinum group metals.

Abstract: A process for the continuous preparation of very highly concentrated hydrogen peroxide having a content of greater than 80 wt.%, especially over 98 wt.%, by suspension crystallization and after-treatment of the H2O2 crystals. The after-treatment takes the form of countercurrent washing in a hydraulic or mechanical washing column with a packed crystal bed. Hydrogen peroxide is disclosed having a concentration of from 99.9 to 100 wt.% and a content of TOC, nitrate, phosphate, nickel and tin of in each case less than 4 mg/l.

Abstract: A process for the concentration of aqueous hydrogen peroxide by discontinuous crystallization. A cooling surface is arranged in a crystallizing vessel and first wetted with hydrogen peroxide and then cooled at a high cooling rate, whereupon seed crystals form. The cooling rate is at least 1 K/s, preferably from 10 to 30 K/s. When the vessel has been filled with H2O2 starting material, the latter crystallizes, starting from the seed crystals, and forms a crystal layer. When the mother liquor of lower H2O2 concentration has been discharged, there follows a sweating operation with a slow increase in temperature, as a result of which the H2O2 concentration in the crystal layer is increased further.

Abstract: A method of manufacturing workpieces, includes loading the workpieces into a treatment facility, surface treating the workpieces in at least one vacuum station of the facility grouped as a station batch and controlling at least the timing of the process by a freely programmable process controller unit. At least two stations operating each on workpiece batches can be grouped as respective station batches and be different with respect to number of workpieces. The workpieces can be transported to and from the grouped stations. An embodiment of vacuum treatment system for such a process includes at least one vacuum treatment station for workpieces grouped as a station batch. A transport system supplies the vacuum station with workpieces. A process controller unit has an output operationally connected to a drive arrangement for the transport system. The unit controls operating timing of the treatment system and is freely programmable.

Abstract: The present invention relates to a method for avoiding undesirable discoloration in polycarbonate production by catalytic removal of dissolved oxygen from phenol by

Abstract: The present invention relates to a process for preparing strongly acidic macroporous or strongly acidic monodisperse-gel-type ion exchangers, particularly macroporous monodisperse, macroporous heterodisperse, or monodisperse-gel-type cation exchangers, by treating the respective basis polymer with sulfuric acid in stepwise cycles at graded concentrations. The invention further relates to the cation exchangers prepared by this process and to their uses.

Abstract: A process for the vacuum treatment of workpieces, includes loading the workpieces into a treatment facility, surface treating the workpieces in at least one vacuum station of the facility grouped as a station batch and controlling at least the timing of the process by a freely programmable process controller unit. At least two stations operating each on workpiece batches can be grouped as respective station batches and be different with respect to number of workpieces. The workpieces can be transported to and from the grouped stations. An embodiment of vacuum treatment system for such a process includes at least one vacuum treatment station for workpieces grouped as a station batch. A transport system supplies the vacuum station with workpieces. A process controller unit has an output operationally connected to a drive arrangement for the transport system. The unit controls operating timing of the treatment system and is freely programmable.

Abstract: The present invention relates to a process for gas adsorption, in particular of acidic gases, using monodisperse aminomethylated bead polymers.

Abstract: The invention relates to an improved process for the preparation of hydrogen peroxide by the anthraquinone process, the improvement being directed at decreasing epoxides in the oxidation stage. According to the invention, the hydrogenated working solution, comprising a 2-alkyl-tetrahydroanthrahydroquinone, is mixed with partly or, preferably, completely oxidized working solution and the mixture is oxidized with a gas comprising oxygen in an oxidation reactor. The volume ratio of hydrogenated to oxidized working solution is in the range from 5 to 1 to 1 to 5 and preferably in the range of 2 to 1 to 1 to 2.

Abstract: A freezer head for pipe freezing devices has a casing having a first exterior side with one or more first exterior depressions for receiving a pipe section to be frozen. The casing has a second exterior side with one or more second exterior depressions. The casing has a hollow interior. The casing has at least one connector configured to supply a cooling medium into the hollow interior. The first depression has a bottom having at least a first bottom portion and a second bottom portion, wherein each one of the first and second bottom portions has a different radius of curvature. The second depression has a bottom having at least a first bottom portion and a second bottom portion, wherein each one of the first and second bottom portions has a different radius of curvature.

Abstract: A hair dyeing composition achieving intensive, stable colorations, which can be varied by the addition of further coupling substances, contains an oxidation dyestuff system reacting with peroxide comprising a combination of a) 2-(2,5-diaminophenyl)ethanol of the water-soluble salts thereof, and b) 2,6-dichloro-4-aminophenol.