Abstract: The invention relates to a complete method for producing pure silicon that is suitable for use as solar-grade silicon, comprising the reduction of a silicon oxide, purified by acidic precipitation from an aqueous solution of a silicon oxide dissolved in an aqueous phase, using one or more pure carbon sources, the purified silicon oxide being obtained, in particular, by the precipitation of a silicon oxide dissolved in an aqueous phase in an acidifier. The invention also relates to a formulation containing an activator and to a device for producing silicon, a reactor and electrodes.

Abstract: The invention relates to a complete method for producing pure silicon that is suitable for use as solar-grade silicon, comprising the reduction of a purified silicon oxide using one or more pure carbon sources, the purified silicon oxide, which was purified as silicon oxide dissolved in an aqueous phase, having a content of other polyvalent metals or metal oxides, in relation to the silicon oxide, of less than or equal to 300 ppm, preferably less than 100 ppm, especially preferably less than 50 ppm and according to the invention less than 10 ppm of the other metals and being obtained advantageously by gel formation in alkaline conditions. The invention also relates to a formulation containing an activator and to the use of purified silicon oxide together with an activator for producing silicon.

Abstract: The object of the invention is a more energy-efficient system for utilizing waste heat and residual gases from the engineered generation of carbon compounds, such as carbon black, graphite or from sugar pyrolysis, using a coupling of energy-heat or a thermal heat-generating plant for generating electrical energy, in particular for operating melt furnaces, and/or for utilizing the waste heat in endothermal processes. The invention also relates to the use of waste heat.

Abstract: The invention relates to a process and to an apparatus for preparing polyether alcohols by alkoxylating alcohols, and also long-chain polyether alcohols having a narrow product distribution. The process is preferably carried out continuously in the liquid phase in a microstructured reactor. An alkylene oxide or different alkylene oxides are metered at one or more points into the channels of the microreactor. The channels are cooled with the aid of a cooling medium or heated with the aid of a heating medium.

Abstract: The present invention relates to a system, a reactor and a process for the continuous industrial conduct of a reaction where a b-unsaturated aliphatic polyether compound A is reacted with an HSi compound B in the presence of a catalyst C and optionally of other auxiliaries, and the system is at least based on the system (3) for combining the starting materials for components A (1) and B (2), on at least one multielement reactor (5) which in turn comprises at least two reactor units in the form of exchangeable pre-reactors (5.1) and comprises at least one further reactor unit (5.3) downstream of the pre-reactors, and on a product-work-up system (8).

Abstract: The present invention relates to a system, to a reactor and to a process for continuous industrial performance of a reaction wherein allyl methacrylate A is reacted with an HSi compound B in the presence of a catalyst C and optionally of further assistants, and the system is based at least on the combination of reactants (3) for components A (1) and B (2), at least one multielement reactor (5) which, in turn, comprises at least two reactor units in the form of exchangeable pre-reactors (5.1) and at least one further reactor unit (5.3) connected downstream of the pre-reactors, and on a product workup (8).

Abstract: The present invention relates to a system, to a reactor and to a process for continuous industrial performance of a reaction wherein allyl glycidyl ether A is reacted with an HSi compound B in the presence of a catalyst C and optionally of further assistants, and the system is based at least on the combination of reactants (3) for components A (1) and B (2), at least one multielement reactor (5) which in turn comprises at least two reactor units in the form of exchangeable pre-reactors (5.1) and at least one further reactor unit (5.3) connected downstream of the prereactors, and on a product workup (8).

Abstract: The present invention relates to a system, to a reactor and to a process for continuous industrial performance of a reaction wherein an ?,?-unsaturated fluorine-substituted olefin A is reacted with an HSi compound B in the presence of a catalyst C and optionally of further assistants, and the system is based at least on the combination of reactants (3) for components A (1) and B (2), at least one multielement reactor (5) which, in turn, comprises at least two reactor units in the form of exchangeable prereactors (5.1) and at least one further reactor unit (5.3) connected downstream of the prereactors, and on a product workup (8).

Abstract: The invention relates to a process and to an apparatus for preparing polyether alcohols by alkoxylating alcohols, and also long-chain polyether alcohols having a narrow product distribution. The process is preferably carried out continuously in the liquid phase in a microstructured reactor. An alkylene oxide or different alkylene oxides are metered at one or more points into the channels of the microreactor. The channels are cooled with the aid of a cooling medium or heated with the aid of a heating medium.

Abstract: The invention relates to a process for the reaction of polyorganosiloxanes, in which a hydrogen atom bound to the silicon is replaced by an alkoxide group, and also to substituted polyorganosiloxanes prepared by this process and their use.

Abstract: Organopolysiloxanes, which terminally, laterally or both have at least one group of the formula ##STR1## well as at least one acrylate group, linked over a bridge element to this group, is obtained by hydrosilylation of organopolysiloxanes with at least one SiH group by compounds, which have at least two acrylate groups, in equimolar amounts at a temperature of 60.degree. to 130.degree. C. in presence of rhodium catalysts. The rhodium catalysts cause a 1,2 addition to take place during the addition reaction between polyacrylates and hydrogen siloxanes.

Abstract: An abhesive coating composition is based on an organopolysiloxane having radiation-curing (meth)acrylate ester groups, which contains an additive that affects the degree of abhesiveness, the additive being obtained by the reaction of an MQ resin with a polysiloxane containing (meth)acrylate ester groups.

Abstract: Polyether siloxanes, which are linked to the polysiloxane backbone through Si--C bonds, are synthesized by reacting given polysiloxanes with a compound having at least one epoxide group in such amounts, that there are at least two epoxide groups per OH group, in the presence of Lewis acids at temperatures not exceeding 60.degree. C. or in the presence of complex catalysts, which accelerate the addition between epoxide groups and hydroxyl groups, at temperatures up to 140.degree. C., the reaction optionally being carried out in the presence of an inert solvent. The polyether siloxanes obtained have a defined functionality and are free of excess, unreacted polyol components.

Abstract: Polysiloxanes of the general formula ##STR1## which contain at least one sulfatohexyl group linked by an Si--C bond are prepared wherein R.sup.1 is a methyl or phenyl group with the proviso that at least 90% of the R.sup.1 groups are methyl groups, R.sup.2 either is identical with R.sup.1 or is --(CH.sub.2).sub.6 --OSO.sub.3.sup.-.M.sup.+, M.sup.+ being an alkali, 1/2 alkaline earth or optionally an alkyl-substituted ammonium ion, R.sup.3 is identical with R.sup.1 or R.sup.2, with the proviso that at least one R.sup.2 or R.sup.3 group in the average molecule is a --(CH.sub.2).sub.6 --OSO3.sup.-.M.sup.+ group, "a"=0 to 5 and b=0 to 5. A method for the synthesis of these compounds and their use as hydrolysis-resistant surfactants is also described.

Abstract: Organopolysiloxanes having polyether and ester groups linked to a common spacer group, wherein the spacer group is linked through an SiC bond to the siloxane backbone and a method for the synthesis thereof are disclosed. These compounds are useful as additives for plastics, lacquers and binders for reducing the coefficient of sliding friction, for improving scratch resistance and increasing abhesiveness. If the compounds are esters of acrylic or methacrylic acid, they can be used as radiation-curable lacquers and coating compositions.

Abstract: 2-(3'-butenyl)-3,4-dihydro-2H-pyrans of the general formula ##STR1## wherein R is a hydrogen group or an alkyl group with 1 to 6 carbon atoms. Methods for the synthesis of these compounds and their use as reactive modifiers or diluents for cationically curable monomers or polymers.

Abstract: Organopolysiloxanes are disclosed which contain, aside from methyl groups, alkyl groups with 1 to 20 carbon atoms, aryl groups or aralkyl groups, epoxy groups which are linked over Si--C bonds to silicon atoms of the polysiloxanes, and R.sup.3 OH groups, R.sup.3 being a divalent alkylene groups with 3 to 11 carbon atoms. The organopolysiloxanes have good compatibility with photoinitiators and adhesion and release properties which can be adjusted for the intended application by coordinating the long chain alkyl groups, the epoxy groups and the --R.sup.3 OH groups.

Abstract: A (meth)acrylate ester-modified organopolysiloxane composition, which is composed of several fractions of equilibrated (meth)acrylate ester-modified organopolysiloxanes that differ in the average number of silicon atoms in the mixture of molecules, is disclosed which contains60 to 95% by weight of a modified organopolysiloxane A having, on the average, 5 to 50 silicon atoms and5 to 40% by weight of a modified organopolysiloxane B having, on the average, at least 50 silicon atoms,with the proviso that the number of silicon atoms in the average molecule of the modified organopolysiloxane B is at least twice as large as the number of silicon atoms in the average molecule of the modified organopolysiloxane A. The organopolysiloxane mixtures have improved abhesive properties.

Abstract: Novel polysiloxanes with (meth)acrylate groups and monocarboxylate groups and their use as radiation-curable abhesive coating matrials are disclosed. The modified polysiloxanes adhere well to the support that is to be coated and can be cured at a high rate on the support. The cured coating has good chemical and physical stabilities and a high flexibility. The abhesive properties can be adapted to the chemical character of the adhesives, so that the desired degree of abhesiveness is obtained.

Abstract: Optical glass fibers are provided with a primary coating of organo-polysiloxanes, containing acrylic acid ester groups, corresponding to the general formula: ##STR1## where the primary coating is free of inert components capable of migration.