Abstract: Zinc oxide powder is prepared by a process having the following steps a) generating of a zinc vapor-containing stream in a vaporization zone; b) oxidizing the zinc vapor by reaction with an oxygen-containing gas thereby forming zinc oxide powder in an oxidation zone; and c) cooling of the reaction mixture with water or an inert gas, and separation of the zinc oxide powder in a cooling/isolation zone, wherein aa) in the vaporization zone, a gas stream of an inert gas and a fuel gas is passed through a zinc melt which has a temperature of 450 to <900° C., thereby forming zinc vapor, the content of fuel gas being 1 to 50 vol. %, based on the sum of inert gas and fuel gas, and the molar quotient of zinc vapor to fuel gas being 0.01 to 50, and bb) in the oxidation zone, a second gas stream, which contains an oxygen-containing gas and steam, is added to the gas stream of zinc vapor, fuel gas and inert gas in an amount such that the temperature in the oxidation zone is from 500 to 1100° C.

Abstract: The present invention relates to a powder which, in addition to a polymer, comprises a flame retardant based on ammonium polyphosphate, to the use of this powder for the layer-by-layer production of moldings, and also to moldings produced from this powder. The moldings constructed using the inventive powder have marked advantages with regard to their flammability, when comparison is made with conventional products, and this permits use in aircraft, for example. Furthermore, moldings produced from inventive powder also have improved mechanical properties, when comparison is made with moldings based on conventional powders, in particular in relation to modulus or elasticity and in relation to tensile strength. In addition, these moldings also have a density close to that of injection moldings.

Abstract: The present invention relates to a polymer powder which comprises polyamide, and to the use of this powder for shaping processes, and also to moldings produced from this polymer powder. The shaping processes are layer-by-layer processes which use powders, where regions of the respective layer are selectively melted via introduction of electromagnetic energy. The selectivity may be achieved, with no intention of restricting the invention thereto, be achieved via masks, application of inhibitors, of absorbers, or of susceptors, or via focusing of the energy introduced. After cooling, the regions then solidified can be removed in the form of moldings from the powder bed.

Abstract: The present invention provides a layered composite, which includes the following layers: (I) a layer I composition including: (a) from 0 to 80 part by weight of at least one polyamide selected from the group including PA6, PA66, PA6/66 and mixtures thereof; (b) from 0 to 100 parts by weight of at least one polyamine-polyamide copolymer that includes the following monomer units: (?) from 0.

Abstract: The present invention provides a layered composite, which includes the following layers:

Abstract: The present invention relates to a process for melting and adhering material to produce three-dimensional objects by means of selective heating via microwave radiation. Unlike selective laser sintering, the present process uses simple microwave radiation commonly available in any household. The selectivity of heating is achieved by applying one or more susceptors to selected regions of a layer composed of a pulverulent substrate, and then heating the susceptor by means of microwave radiation. The heated susceptor transfers the energy present therein to a pulverulent substrate surrounding the susceptor, and the substrate is thereby melted, providing firm adhesion within the substrate after cooling.

Abstract: An oxime is synthesized by ammoximation of a carbonyl compound. In stage (i) of the process, a carbonyl compound containing 6 to 20 C atoms is reacted with ammonia and hydrogen peroxide in the presence of a) an organic solvent that is a1) at least partly water-soluble, a2) stable under ammoximation conditions, a3) has a boiling point of higher than 100° C. and/or is capable of forming a two-phase azeotrope with water, and b) a titanium-containing heterogeneous catalyst. After the reaction, the catalyst is separated from the reaction mixture. The oxime is crystallized and separated from the reaction mixture. Water is removed from the remaining mother liquor, provided the mother liquor is a two-phase system in which one of the phases is an aqueous phase. Water or a water-containing two-phase azeotrope is distilled off from the mother liquor, while the distillation bottoms and, optionally, the predominantly organic phase of the azeotrope are recycled to stage (i).

Abstract: A carbonaceous material with organic groups obtainable by reacting carbonaceous material with organic compounds of the general formula I

Abstract: Powder coating compositions based on carboxyl- and/or hydroxyl-containing polyesters, crosslinkers, and other customary additives for coatings having a matt appearance and methods for providing coatings having a matt appearance.

Abstract: A process for depositing a solid (B) proceeds by targeted thermal decomposition of a gaseous substance (A). The substance (A) has a higher density than the gaseous product (C) formed during the decomposition. In the process, a device is used which has a cup (1), the base (1.1) of which is oriented in the direction of the force of gravity (g) and the opening region (1.2) of which is oriented in the opposite direction to the force of gravity (g). The cup (1) can be heated directly or indirectly by a heating, temperature-measuring and control unit (3.3). The device further contains a substance-adding unit (2) with substance feedline (3.1) and metering unit (3.2), the substance-adding unit (2) being oriented with the substance outlet (2.1) in the direction of the force of gravity (g) and projecting into the free volume of the cup (1) between the base (1.1) and opening region (1.2). The device also has a reactor casing (3) and an outlet (3.6) for gaseous product (C).

Abstract: Aqueous dispersion comprising silicon/titanium mixed oxide powder with a BET surface area of 5 to 500 m2/g which has been prepared by flame hydrolysis and has a titanium dioxide content of 0.5 to 20 wt. %, based on the powder, water and at least one pH-regulating substance which can be removed completely from the reaction mixture on heating, the aqueous dispersion having a solids content of between 40 and 80 wt. %. A green body produced therefrom with a green density of between 40 and 85%. A shaped glass article of optical quality with a coefficient of thermal expansion of not more than 0.5×10−6/K produced from the green body.

Abstract: The present invention provides a process for preparing a mixture, which mixture includes catenate and cyclic siloxanes of formula I

Abstract: The present invention relates to a catalyst and to a process for preparing color-reduced polyisocyanates containing isocyanurate groups.

Abstract: The present invention relates to a catalyst and to a process for preparing color-reduced polyisocyanates containing isocyanurate groups.

Abstract: Rec-hydantoinases which may be obtained in more active form by a the process described herein. The invention also relates, inter alia, to a rechydantoinase from the organism Arthrobacter crystallopoietes DSM20117, to nucleic acids which code for such a protein and to vectors containing said nucleic acids and to uses thereof.

Abstract: A composition containing (i) at least one silicon-containing compound, (ii) at least one peroxidic free-radical initiator, and (iii) at least one conjugated hydrocarbon and/or at least one organofunctional silane of the general formula I

Abstract: Methylheptanone and corresponding homologous methylketones, in particular phytone and tetrahydrogeranyl acetone, are produced by aldol condensation of isovaleraldehyde or prenal or the corresponding aldehydes with acetone in the presence of a catalyst phase, which contains an aldolizing catalyst and a heterogeneous hydrogenating catalyst.

Abstract: The invention relates to polynucleotides corresponding to the oxyR gene and which encode a OxyR transcriptional regulator, methods of producing L-amino acids, and methods of screening for polynucleotides which encode proteins having OxyR transcriptional regulator activity.

Abstract: The invention relates to a process for the production of .epsilon.-caprolactone having a purity of 99.9% and increased color and storage stability which comprises feeding .epsilon.-caprolactone, which has been made by reacting cyclohexanone with a solution of a percarboxylic acid, into a first distillation unit, operating at 0.1 to 500 mbars and drawing off as the top product a mixture consisting of .epsilon.-caprolactone and lower-boiling impurities, feeding the bottom product of said first distillation unit into a second distillation unit, operating at 0.1 to 500 mbars and then drawing off the pure .epsilon.-caprolactone as the top product. The .epsilon.-caprolactone is useful as an intermediate for the production of known useful compounds such as polyesterols which are subsequently converted to polyurethanes.