Abstract: A process for producing a transparent or opaque silica glass product including mixing a silica fine powder and a cellulose derivative and injection molding the mixture, followed by degreasing treatment and baking treatment, which is characterized in that the cellulose derivative is a cellulose derivative which causes reversible thermal gelation in an aqueous solution of at least one member selected from methyl cellulose, hydroxypropylmethyl cellulose and hydroxyethylmethyl cellulose; in producing a transparent silica glass product, the cellulose derivative is added in water heated at a gelation temperature thereof or higher, and after cooling, the formed aqueous solution is kneaded with the silica fine powder; and in producing an opaque silica glass product, the cellulose derivative is added in a silica slurry containing a silica powder and heated at a gelation temperature of the cellulose derivative or higher.

Abstract: A process for producing a transparent or opaque silica glass product including mixing a silica fine powder and a cellulose derivative and injection molding the mixture, followed by degreasing treatment and baking treatment, which is characterized in that the cellulose derivative is a cellulose derivative which causes reversible thermal gelation in an aqueous solution of at least one member selected from methyl cellulose, hydroxypropylmethyl cellulose and hydroxyethylmethyl cellulose; in producing a transparent silica glass product, the cellulose derivative is added in water heated at a gelation temperature thereof or higher, and after cooling, the formed aqueous solution is kneaded with the silica fine powder; and in producing an opaque silica glass product, the cellulose derivative is added in a silica slurry containing a silica powder and heated at a gelation temperature of the cellulose derivative or higher.

Abstract: A composition for ceramic extrusion-molded bodies includes a ceramic material, a water-soluble cellulose ether, a styrenesulfonate and water. A method for manufacturing a ceramic extrusion-molded body using the composition is also provided.

Abstract: Provided is a dispersion stabilizer for suspension polymerization that contains a hydroxypropylmethylcellulose with a degree of methoxy group substitution of 27 to 30% by mass and a degree of hydroxypropoxy group substitution of 5 to 12% by mass, in which the viscosity at 20° C. of a 2% by mass aqueous solution of the hydroxypropylmethylcellulose is within a range from 5 to 1,600 mPa·s, and in 2 ml of a 0.2% by mass solution of the hydroxypropylmethylcellulose, the number of undissolved fibers with a particle size within a range from 8 to 200 ?m, as measured by a Coulter counter method, is not more than 1,000, and the number of undissolved fibers with a particle size of 50 ?m or greater measured using the same method is not more than 20. By employing a method of producing a vinyl chloride-based polymer that uses this dispersion stabilizer, a vinyl chloride-based polymer with extremely low levels of fish eyes and defects derived from foreign objects can be produced.

Abstract: A process for producing a transparent or opaque silica glass product including mixing a silica fine powder and a cellulose derivative and injection molding the mixture, followed by degreasing treatment and baking treatment, which is characterized in that the cellulose derivative is a cellulose derivative which causes reversible thermal gelation in an aqueous solution of at least one member selected from methyl cellulose, hydroxypropylmethyl cellulose and hydroxyethylmethyl cellulose; in producing a transparent silica glass product, the cellulose derivative is added in water heated at a gelation temperature thereof or higher, and after cooling, the formed aqueous solution is kneaded with the silica fine powder; and in producing an opaque silica glass product, the cellulose derivative is added in a silica slurry containing a silica powder and heated at a gelation temperature of the cellulose derivative or higher.

Abstract: In an extrusion or injection molding composition comprising water-insoluble particles, a water-soluble binder, and water, true spherical particles having an average particle size of 0.2-20 ?m are used as the water-insoluble particles. The addition of a small amount of a binder to water-insoluble particles as the substrate facilitates molding operation and enables to produce a molded part featuring a shape stability after molding.

Abstract: A water-soluble cellulose ether is selected by judging whether the number of undissolved fibers having a size of 16–200 ?m is up to 350 fibers/2 ml in a 0.1 wt % aqueous solution of the cellulose ether at 25° C. This water-soluble cellulose ether forms an aqueous solution which can be filtered without clogging and can form a very thin film without defectives.

Abstract: A water-soluble cellulose ether is selected by judging whether the number of undissolved fibers having a size of 16-200 &mgr;m is up to 350 fibers/2 ml in a 0.1 wt % aqueous solution of the cellulose ether at 25° C. This water-soluble cellulose ether forms an aqueous solution which can be filtered without clogging and can form a very thin film without defectives.