摘要:
Colored pigments are provided from the green-yellow to red spectrum based on oxide-nitrides with two or three different cations Q, R and S in the crystal lattice, wherein the nitrogen to oxygen atomic ratio is determinative for the color. These pigments crystallise in the pyrochlore, spinel or elpasolite structure. Pigments in the perovskite are as provided with increased color brilliance. The color of the pigments can be adjusted in a wide range of the color spectrum during their preparation within a substance class with the cations Q, R and S and while retaining the crystal structure, by increasing or lowering the atomic ratio N to O in the oxide-nitride and bringing about the required charge balancing by replacing an equivalent quantity of the cation Q with the valency q by a cation R with the valency q+1. In order to prepare the pigments, a mixture of oxide-nitride-forming metal compounds in the atomic ratio of the cations according to the structural formula is calcined, preferably in the presence of mineralizers, under nitriding conditions at 700.degree.-1250.degree. C.
摘要:
Oxonitrides with a perovskite of the general formula LnTaOn.sub.2, where Ln is a rare-earth element, and which exhibit an enhanced brightness, are produced by annealing a powder mixture consisting of a Ta (V) compound and a Ln compound in a reducing atmosphere that contains ammonia. Added to the powder mixture being annealed is a mineralizing agent from the series of alkali metal or alkaline earth halides, Na.sub.3 AlF.sub.6, Na.sub.2 SiF.sub.6, AlF.sub.3 or of the ammonia salts of carbonic acid or a mono- or dicarboxylic acid with 1 to 4 C atoms in a quantity of 0.1 to 10 parts by weight, relative to 1 part by weight of the mixture of the Ta and Ln compounds. Such oxonitrides can be used as pigments that are yellow-orange to reddish brown in color.
摘要:
Silicon diimide having a carbon content of at most 0.5% by weight and a chlorine content of at most 20 ppm is prepared by reacting ammonia with organyl amino silane at 50.degree.-300.degree. C. at elevated pressure and is useful as an intermediate for high grade silicon nitride.
摘要:
A fluid swivel is described, which enable the measurement and the adjustment of separation of seal surfaces. The fluid swivel includes inner and outer walls that are rotatably coupled about an axis and that form an annular chamber and a pair of gaps extending from the chamber. A hollow region is formed along each gap for holding a face seal, and the gap forms an extrusion gap portion extending radially from each hollow region. The inner and outer walls form axially-spaced wall surfaces adjacent to the hollow region, and one of the walls has a gage-passing passage leading from the outside of the wall to the space between the wall surfaces to pass a gage for measuring the separation gap between the wall surfaces. One of the walls includes a plurality of parts and also includes shims between the parts for enabling slight adjustment of the spacing between the seal surfaces, depending on the thickness of the shims.