Patents by Inventor Kasumi Hoshikawa

Kasumi Hoshikawa has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6849242
    Abstract: The granule consists of individual granules approximately spherical in shape, having a pore volume of 0.5 cm3, a mean diameter of pores of 50 nm or less, a specific surface area of 100 m2/g or less, and a bulk density of 0.7 g/cm3 or higher. It is produced by dispersing a fumed silica obtained by hydrolysis of a silicon compound into pure water to obtain a slurry, and drying the slurry. The granule is used for producing high purity synthetic quartz glass powder. The method further comprises: a first heat treatment under an oxygen-containing atmosphere, a second heat treatment in a temperature range of from 600 to 1100° C., and a third heat treatment in a temperature range of from 1100 to 1300° C. under an atmosphere containing hydrogen chloride; and a step of densification comprising calcining the product at a temperature not higher than 1500° C. under vacuum or in an atmosphere of gaseous hydrogen or gaseous helium.
    Type: Grant
    Filed: September 28, 2000
    Date of Patent: February 1, 2005
    Assignees: Heraeus Quarzglas GmbH & Co. KG, Shin-Etsu Quartz Products Co., Ltd.
    Inventors: Rainer Koeppler, Fritz-Ulrich Kreis, Klaus Arnold, Hiroshi Matsui, Kasumi Hoshikawa, Tsukasa Sakaguchi