Abstract:
A quartz glass substrate for polysilicon thin film transistor liquid crystal display, in which a halogen content is not more than 10 ppm; an OH content is not more than 100 ppm; a total content of a heavy metal element and an alkali metal element is not more than 1 ppm; and an annealing point is not less than 1,150.degree. C.
Abstract:
A torch is provided for decomposing a volatile metal chloride by hydrolysis to directly form an oxide article on a mandrel. The torch includes a nozzle which provides an output jet stream of vaporized metal chloride. Sheath openings in the nozzle provide a supply of gas which is relatively inert with respect to the gaseous metal chloride for preventing reaction immediately adjacent the nozzle face. A plurality of slanted nozzle openings are provided in the nozzle for directing angled streams of combustible gas through the sheath stream at a selected region for reaction with the jet stream of gaseous metal chloride. When the gas streams are ignited, a torch flame is provided which may be directly impinged upon a mandrel in order to directly form an oxide article of high purity thereon.
Abstract:
PURPOSE:To obtain transparent and uniform quartz glass in the process for prepg. quartz glass by the sol-gel process using alkyl silicate, and fine pulverous silica as main raw materials by removing foreign matters by centrifuging the sol in the stage or after prepn. of the sol. CONSTITUTION:White sol is prepd. by mixing alkyl silicate (e.g. ethyl silicate), water, hydrochloric acid, and fine silica powder, etc. and prepg. white sol by stirring or dispersing with supersonic wave, etc. Then, the sol is centrifuged to remove foreign matters in the sol, adjusting the pH of the sol to 3-5 by dropping aq. NH3, and foreign matters are removed further by centrifuging again. Then, the sol is gelled in a specified vessel; the gel is dried in a dryer when the gel begins to shrink. Obtd. dry gel is heated and sintered in a sintering furnace. By this method, quartz glass contg. only trace amt. of foam and foreign matters and suitable as a parent material of optical fiber is prepd.
Abstract:
This invention is to provide a synthetic quartz glass plate for an excimer UV lamp device, which is good and uniform in light extraction efficiency over the whole surface when it is used as a window material for the excimer UV lamp device. The synthetic quartz glass plate for the excimer UV lamp device is formed from synthetic quartz glass synthesized by a flame hydrolysis method using a high purity silicon compound as a raw material. The synthetic quartz glass plate for the excimer UV lamp device emitting vacuum ultra-violet rays having wavelengths of 150-250 nm is characterized in that it is obtained by joining at least two synthetic quartz glass sheets by confronting mutual edge faces of the sheets, the total length of the outer peripheries of the plate after joining is ≥ 2,700 mm, the thickness is 3-10 mm, the fluctuation width in thickness is ≤ 1 mm, the bending of the plate by joining is ≤ 3 mm, the birefringence at the joined part is ≤ 80 nm/cm, the number of independent bubbles each having a major diameter of