Abstract: The invention relates to a process for producing a paste-like SiO2 composition using an SiO2 slip which allows simple intermediate storage and transport conditions without the processability of the slip to give the paste-like SiO2 composition being impaired thereby. According to the invention, it is for this purpose proposed that a homogeneous SiO2 base slip be subjected to a drying step to form a dry SiO2 composition and subsequently be processed further by means of a remoistening step to give the paste-like SiO2 composition, where the remoistening step comprises the addition of liquid to the dry SiO2 composition to form a paste-like kneadable SiO2 composition having a solids content of more than 85% by weight. The invention further relates to the use of a paste-like SiO2 composition as repair composition.

Abstract: The invention relates to a process for producing a paste-like SiO2 composition using an SiO2 slip which allows simple intermediate storage and transport conditions without the processability of the slip to give the paste-like SiO2 composition being impaired thereby. According to the invention, it is for this purpose proposed that a homogeneous SiO2 base slip be subjected to a drying step to form a dry SiO2 composition and subsequently be processed further by means of a remoistening step to give the paste-like SiO2 composition, where the remoistening step comprises the addition of liquid to the dry SiO2 composition to form a paste-like kneadable SiO2 composition having a solids content of more than 85% by weight. The invention further relates to the use of a paste-like SiO2 composition as repair composition.

Abstract: In a known method, a SiO2 slip layer is applied to a basic quartz glass body by means of spraying on an SiO2 slip, the slip layer is dried and sintered to form an SiO2-containing functional layer.

Abstract: To optimize a known method for producing a composite body from a basic body of opaque quartz glass and a dense sealing layer, in such a way that the basic body can be provided with the dense sealing layer without any significant changes and deformations in the opaque material being noticed, the invention suggests a method comprising the following steps: (a) producing the basic body by using a first slip which contains larger amorphous SiO2 particles; (b) providing a second slip which contains smaller amorphous SiO2 particles and the composition of which differs from that of the first slip at least in that it contains SiO2 nanoparticles in the range between 0.2% by wt. to 15% by wt. and which is distinguished by a relatively low vitrification temperature; (d) producing a slip layer from the second slip on a surface of the basic body, drying the slip layer, and (e) subsequently vitrifying the slip layer with formation of the dense sealing layer.

Abstract: In a known method, a SiO2 slip layer is applied to a basic quartz glass body by means of spraying on an SiO2 slip, the slip layer is dried and sintered to form an SiO2-containing functional layer.

Abstract: SiO2 slurry for the production of quartz glass contains a dispersion liquid and amorphous SiO2 particles with particle sizes to a maximum of 500 ?m. The largest volume fraction is SiO2 particles with particle sizes of 1 ?m-60 ?m, as well as SiO2 nanoparticles with particle sizes less than 100 nm constituting 0.2-15% volume by weight of the entire solids content. To prepare the slurry for use and optimize its flow behavior for later processing by dressing or pouring the slurry mass, and for later drying and sintering without cracks, the slurry has SiO2 particles with a multimodal distribution of particle sizes, with a first maximum in the range 1 ?m-3 ?m and a second maximum in the range 5 ?m-50 ?m, and an 83%-90% solids content by weight of the SiO2 particles and the SiO2 nanoparticles together.

Abstract: SiO2 slurry for the production of quartz glass contains a dispersion liquid and amorphous SiO2 particles with particle sizes to a maximum of 500 ?m. The largest volume fraction is SiO2 particles with particle sizes of 1 ?m-60 ?m, as well as SiO2 nanoparticles with particle sizes less than 100 nm constituting 0.2-15% volume by weight of the entire solids content. To prepare the slurry for use and optimize its flow behavior for later processing by dressing or pouring the slurry mass, and for later drying and sintering without cracks, the slurry has SiO2 particles with a multimodal distribution of particle sizes, with a first maximum in the range 1 ?m-3 ?m and a second maximum in the range 5 ?m-50 ?m, and an 83%-90% solids content by weight of the SiO2 particles and the SiO2 nanoparticles together.

Abstract: A known SiO2 slurry for the production of quartz glass contains a dispersion liquid and amorphous SiO2 particles with particle sizes to a maximum of 500 ?m, wherein the largest volume fraction is composed of SiO2 particles with particle sizes in the range 1 ?m-60 ?m, as well as SiO2 nanoparticles with particle sizes less than 100 nm in the range 0.2-15% volume by weight (of the entire solids content). In order to prepare such a slurry for use, and to optimize the flow behavior of such a slurry with regard to later processing by dressing or pouring the slurry mass, and with regard to later drying and sintering without cracks, the invention suggests a slurry with SiO2 particles with a multimodal distribution of particle sizes, with a first maximum of the sizes distribution in the range 1 ?m-3 ?m and a second maximum in the range 5 ?m-50 ?m, and a solids content (percentage by weight of the SiO2 particles and the SiO2 nanoparticles together) in the range 83%-90%.

Abstract: In a known method for producing quartz glass that is doped with nitrogen, an SiO2 base product is prepared in the form of SiO2 grains or in the form of a porous semi-finished product produced from the SiO2 grains and the SiO2 base product is processed into the quartz glass with the nitrogen chemically bound therein in a hot process in an atmosphere containing a reaction gas containing nitrogen. From this starting point, a method is provided for achieving nitrogen doping in quartz glass with as high a fraction of chemically bound nitrogen as possible. This object is achieved according to the invention in that a nitrogen oxide is used as the nitrogen-containing reaction gas, and that a SiO2 base product is used that in the hot process has a concentration of oxygen deficient defects of at least 2×1015 cm?3, wherein the SiO2 base product comprises SiO2 particles having an average particle size in the range of 200 nm to 300 ?m (D50 value).

Abstract: Methods for producing a quartz glass component with reflector layer are known in which a reflector layer composed of quartz glass acting as a diffuse reflector is produced on at least part of the surface of a substrate body composed of quartz glass. In order, taking this as a departure point, to specify a method which enables cost-effective and reproducible production of uniform SiO2 reflector layers on quartz glass components, it is proposed according to the invention that the reflector layer is produced by thermal spraying by means of SiO2 particles being fed to an energy carrier, being incipiently melted or melted by means of said energy carrier and being deposited on the substrate body. In the case of a quartz glass component obtained according to the method, the SiO2 reflector layer is formed as a layer which is produced by thermal spraying and has an opaque effect and which is distinguished by freedom from cracks and uniformity.

Abstract: In a known method for bonding components made of material with a high silicic acid content by means of a substance to substance bond, a SiO2-containing bonding mass is formed between connecting surfaces of the components. In order to provide for cost-efficient manufacture of a thermally stable composite, the invention proposes to generate a SiO2-containing bonding mass that is generic with regard to the material with a high silicic acid content, comprising the following procedural steps: provision of a slurry containing amorphous SiO2 particles; formation of a slurry mass between the connecting surfaces which are fixed in position with regard to each other; drying of the slurry mass; and solidification of the slurry mass by heating under formation of the SiO2-containing bonding mass. A component assembly manufactured according to the method of the invention shows high temperature resistance and thermal fatigue resistance and can also be used in contamination-sensitive applications.

Abstract: In a known exterior deposition method for producing synthetic quartz glass, amorphous quartz glass powder particles (13) are fed to a reaction zone (12), the quartz glass powder particles are heated in the reaction zone (12) and deposited on the exterior side of a carrier (10) rotating about an axis of rotation. In order, proceeding from this, to specify a method which is distinguished by a high deposition efficiency, according to the invention it is proposed that amorphous quartz glass powder particles having a particle size of at least 3 ?m together with a silicon-containing starting substance (14) are fed to the reaction zone (12), wherein the silicon-containing starting substance (14) is converted to SiO2 particles in the reaction zone, and the SiO2 particles are deposited in Co-15 deposition with the quartz glass powder particles on the carrier to form an SiO2-containing layer (11) in which the quartz glass powder particles (13) make up a proportion by weight of SiO2 in the range of 30% to 95%.

Abstract: In a known method for producing a raised marking on a glass object, a suspension containing SiO2 particles is applied to a surface of the glass object as a pattern, and the pattern is compacted to form the marking. Starting from this, in order to enable a cost-effective production of an optically appealing and uniform marking on an object made of quartz glass, which marking is also suited for applications at high temperature or in a contamination-sensitive environment, such as in solar cell and semiconductor production, it is suggested according to the invention that a binder-free suspension be used to create a marking on a quartz glass object, the suspension containing a dispersion liquid and amorphous SiO2 particles having particle sizes of up to a maximum of 500 ?m, of which are between 0.2% by wt. and 15% by wt. SiO2 nanoparticles having particle sizes of less than 100 nm, and the solids content thereof, i.e.

Abstract: An ideal quartz glass for a wafer jig for use in an environment having an etching effect is distinguished by both high purity and high resistance to dry etching. To indicate a quartz glass that substantially fulfills these requirements, it is suggested according to the invention that the quartz glass is doped with nitrogen at least in a near-surface area, has a mean content of metastable hydroxyl groups of less than 30 wt ppm and that its fictive temperature is below 1250° C. and its viscosity is at least 1013 dPa·s at a temperature of 1200° C. An economic method for producing such a quartz glass comprises the following method steps: melting an SiO2 raw material to obtain a quartz glass blank, the SiO2 raw material or the quartz glass blank being subjected to a dehydration measure, heating the SiO2 raw material or the quartz glass blank to a nitriding temperature in the range between 1050° C. and 1850° C.

Abstract: To optimize a known method for producing a composite body from a basic body of opaque quartz glass and a dense sealing layer, in such a way that the basic body can be provided with the dense sealing layer without any significant changes and deformations in the opaque material being noticed, the invention suggests a method comprising the following steps: (a) producing the basic body by using a first slip which contains larger amorphous SiO2 particles; (b) providing a second slip which contains smaller amorphous SiO2 particles and the composition of which differs from that of the first slip at least in that it contains SiO2 nanoparticles in the range between 0.2% by wt. to 15% by wt. and which is distinguished by a relatively low vitrification temperature; (d) producing a slip layer from the second slip on a surface of the basic body, drying the slip layer, and (e) subsequently vitrifying the slip layer with formation of the dense sealing layer.

Abstract: The invention relates to a method for the economic production of a blank for a component made from laser-active quartz glass in any form or dimension. The method comprises the following method steps: a) preparation of a dispersion with a solids content of at least 40 wt. %, comprising SiO2 nanopowder and doping agents, including a cation of the rare earth metals and transition metals in a fluid, b) granulation by agitation of the dispersion, with removal of moisture to form a doped SiO2 granulate of spherical porous granular particles with a moisture content of less than 35 wt. % and a density of at least 0.95 g/cm3, c) drying and purification of the SiO2 granulate, by heating to a temperature of at least 1000° C. to form doped porous SiO2 grains with an OH content of less than 10 ppm and d) sintering or fusing the doped SiO2 grains in a reducing atmosphere to give the blank made from doped quartz glass.

Abstract: Methods for producing a quartz glass component with reflector layer are known in which a reflector layer composed of quartz glass acting as a diffuse reflector is produced on at least part of the surface of a substrate body composed of quartz glass. In order, taking this as a departure point, to specify a method which enables cost-effective and reproducible production of uniform SiO2 reflector layers on quartz glass components, it is proposed according to the invention that the reflector layer is produced by thermal spraying by means of SiO2 particles being fed to an energy carrier, being incipiently melted or melted by means of said energy carrier and being deposited on the substrate body. In the case of a quartz glass component obtained according to the method, the SiO2 reflector layer is formed as a layer which is produced by thermal spraying and has an opaque effect and which is distinguished by freedom from cracks and uniformity.

Abstract: A known SiO2 slurry for the production of quartz glass contains a dispersion liquid and amorphous SiO2 particles with particle sizes to a maximum of 500 ?m, wherein the largest volume fraction is composed of SiO2 particles with particle sizes in the range 1 ?m-60 ?m, as well as SiO2 nanoparticles with particle sizes less than 100 nm in the range 0.2-15% volume by weight (of the entire solids content). In order to prepare such a slurry for use, and to optimize the flow behavior of such a slurry with regard to later processing by dressing or pouring the slurry mass, and with regard to later drying and sintering without cracks, the invention suggests a slurry with SiO2 particles with a multimodal distribution of particle sizes, with a first maximum of the sizes distribution in the range 1 ?m-3 ?m and a second maximum in the range 5 ?m-50 ?m, and a solids content (percentage by weight of the SiO2 particles and the SiO2 nanoparticles together) in the range 83%-90%.

Abstract: The present invention relates to a method for bonding components made of high silica material by way of integral joining by forming a high-silica bonding mass between connecting surfaces of the components. A method is provided which permits an inexpensive production of a mechanically and thermally stable composite of components made of a high silica material, particularly for large-area bonded connections for which a contact pressure of more than 5 N/cm2 is applied while the connecting surfaces are being fixed, and/or the path length for possible degassing products from the bonded connection is more than 150 mm. This object is achieved according to the invention in that the SiO2 bonding mass is used in dry form either right from the beginning or at least the SiO2 bonding mass is dried on the connecting surfaces before the joining process and the surfaces to be bonded are subsequently brought into contact and a firm composite is created by way of heating with formation of a SiO2 containing bonding mass.

Abstract: The invention relates to methods for producing a coated component consisting of quartz glass, according to which the component surface is at least partially provided with a SiO2 glass composition that differs from the quartz glass of the base body. The aim of the invention is to provide a novel way of coating a quartz glass component with a SiO2 glass composition that can be produced in a cost-effective, reproducible manner, with any thickness, and can fulfil various functions according to the concrete embodiment thereof. To this end, an amorphous slip containing SiO2 particles is produced and applied to the surface of the base body, forming a slip layer which is dried and then vitrified, forming a SiO2 glass composition. The quartz glass components coated in this way can be advantageously used especially in the production of semiconductors.