摘要:
There are provided an apparatus and a method for manufacturing a vitreous silica crucible which can prevent the deterioration of the inner surface property in the manufacturing process of a vitreous silica crucible. The apparatus includes a mold defining an outer shape of a vitreous silica crucible, and an arc discharge unit having electrodes and a power-supply unit, wherein each of the electrodes includes a tip end directed to the mold, the other end opposite to the tip end, and a bent portion provided between the tip end and the other end.
摘要:
The present invention provides a method of manufacturing a vitreous silica crucible by heating and fusing a silica powder layer in a rotating mold by arc discharge generated by carbon electrodes comprising: a preparation process for determining optimal temperatures during heating and fusing the silica powder layer for one or more selected from the group consisting of the silica powder layer, fume generated during arc fusing, and arc flame generated in the arc discharge; a temperature measuring process for measuring actual temperatures during heating and fusing for one or more selected from the group where the optimal temperatures are determined; and a temperature controlling process for controlling the actual temperatures for one or more selected from the group where the actual temperatures are measured so that the actual temperatures match the optimal temperatures.
摘要:
There is provided a method of manufacturing a vitreous silica crucible having a suitably controlled inner surface property. The present invention provides a method of manufacturing a vitreous silica crucible by heating and fusing a silica powder layer in a rotating mold by arc discharge generated by carbon electrodes including: a preparation process for determining optimal fusing temperatures during heating and fusing the silica powder layer at plural points of different heights of the silica powder layer; a temperature measuring process for measuring actual temperatures during heating and fusing the silica powder layer at the plural points; a temperature controlling process for controlling the actual temperatures at the plural points so that the actual temperatures matches the optimal fusing temperatures at the respective points.
摘要:
Accurate temperature measurement during manufacturing a vitreous silica crucible is enabled. The present invention provides an apparatus for manufacturing a vitreous silica crucible including: a mold for forming a silica powder layer by supplying silica powder therein; an arc discharge unit having carbon electrodes and a power supply unit and for heating and fusing the silica powder layer by arc discharge; and a temperature measurement unit for measuring temperature of a fused portion in the mold, wherein the temperature measurement unit is an radiation thermometer for measuring temperature by detecting radiation energy of a wavelength of 4.8 to 5.2 μm.
摘要:
Provided is a vitreous silica crucible which can suppress inward sagging and buckling of the sidewall effectively even when time for pulling silicon ingots is extremely long. According to the present invention, provided is a vitreous silica crucible for pulling a silicon single crystal, wherein the crucible has a wall comprising, from an inner surface toward an outer surface of the crucible, a transparent vitreous silica layer having a bubble content rate of less than 0.5%, a bubble-containing vitreous silica layer having a bubble content rate of 1% or more and less than 50%, a semi-transparent vitreous silica layer having a bubble content rate of 0.5% or more and less than 1.0% and having an OH group concentration of 35 ppm or more and less than 300 ppm.
摘要:
The present invention provides a method of manufacturing a vitreous silica crucible including: a silica powder supplying process of supplying a material silica powder into a mold for molding a vitreous silica crucible, to form a silica powder layer, and an arc fusing process of arc fusing the silica powder layer by arc discharge generated by carbon electrodes, wherein the arc fusing process includes processes of measuring temperatures at measuring points provided on different heights of an inner surface of the silica powder layer while rotating the mold, and controlling the arc discharge to enable detection, at each measuring point, of a local maximum point which appears first in the arc fusing process.
摘要:
The present invention provides a vitreous silica crucible which can suppress buckling and sidewall lowering of the crucible without fear of mixing of impurities into silicon melt. According to the present invention, provided is a vitreous silica crucible for pulling a silicon single crystal, wherein a ratio I2/I1 is 0.67 to 1.17, where I1 and I2 are area intensities of the peaks at 492 cm−1 and 606 cm−1, respectively, in Raman spectrum of vitreous silica of the region having a thickness of 2 mm from an outer surface to an inner surface of a wall of the crucible.
摘要:
Provided is a method of calculating a temperature distribution with higher accuracy than a conventional method, which calculates a temperature distribution of an inner surface of a silica powder molded body during manufacturing based on boundary conditions corrected in accordance with the actually measured temperature in consideration of plasma radiation by arc discharge and heat radiation of arc discharge.According to a method of calculating a temperature distribution of a crucible during manufacturing, includes a temperature calculation process in which a temperature calculator calculates temperature distribution in an inner surface of a silica powder molded body through a numerical calculation method which mesh-divides an object to be calculated, by calculating heat flux from heat plasma modeled by a gas flow and radiation of heat plasma radiated from arc electrodes, wherein the temperature distribution is calculated by adjusting gas flow and radiation conditions in a way that the calculated temperature distribution and the actually measured temperature distribution of an inner surface of a silica powder molded body becomes similar, and reading, from a correspondence table, gas flow and radiation conditions corresponding each step of a control sequence for producing a crucible.
摘要:
A compound represented by the following general formula (1): wherein R1 represents a hydrogen atom or a C2 to C4 alkanoyl group and R2 represents a group represented by the following formula (A), (B), (C), (D), (E), (F), or (G): wherein R3 represents a C1 to C4 alkyl group can inhibit macrophage activation. Accordingly, a macrophage activation inhibitor containing a compound represented by the general formula (1) or its pharmacologically acceptable salt as an active ingredient is useful as an agent for preventing, improving, or treating a disease resulting from infection with pathogens such as a bacterium and a virus.
摘要:
An object of the present invention is to provide a novel polymer coated metal oxide. A polymer coated metal oxide according to the present invention is characterized in that a polymer has a siloxane skeletal structure. A polymer coated metal oxide manufacturing method according to the present invention is a method of contacting a metal oxide with a solution of a polymer having a siloxane skeletal structure. As a result, a polymer can be bonded to the surface of a metal oxide. Herein, it is preferable that a polymer should have a branching structure. Also, it is preferable that the polymer having the branching structure should be a dendritic polymer. Further, it is preferable that a metal oxide should be glass, silica gel, titanium oxide, barium titanate, indium tin oxide (ITO), aluminum oxide, nickel oxide, iron oxide and the like.