Yoshino Gypsum Co., Ltd.

Kenichi Sugano

Masato Yoshikane

Emi Mamada

Tatsuya Horiuchi

Masaru Yoshida

Shinichi Miura

Yusuke Ichino

The present invention provides a gypsum-based embedding material composition for casting useful for forming a rapid-heating type gypsum-based embedding material and a method for producing the same. The gypsum-based embedding material is formed of the gypsum-based powdery embedding material composition by adding a malaxation liquid into the composition and heating the mixture in a high-temperature furnace. The gypsum-based embedding material composition contains as main components, at least one co-pulverized material selected from a co-pulverized material of calcined gypsum and quartz, that of calcined gypsum and cristobalite, and that of calcined gypsum, quartz, and cristobalite. The composition further contains a powdery moisture-retaining component or a liquid moisture-retaining component having a low water content, and has an average particle diameter of 30 μm or less.

Gypsum-based investment material composition for casting, and method for manufacturing gypsum-based investment material composition for casting

The present invention intends to provide a method by which the scattering property of a powder can be more clearly evaluated. There is provided a method for evaluating a scattering property of a powder, the method including dropping a powder to be evaluated onto a liquid placed in a box, thereby scattering the powder as dust in the box, and measuring a dust concentration in air in the box with a dust meter. There is also provided an apparatus for evaluating a scattering property of a powder, the apparatus including a box in which a liquid is to be placed, and a dust meter that measures a dust concentration in air in the box when the powder to be evaluated drops onto the liquid placed in the box and scatters as dust.

Powder dustiness evaluation method and powder dustiness evaluation device

The present invention intends to provide a practically valuable insolubilizing material for a designated hazardous substance (a heavy metal or the like) and an insolubilization method using the insolubilizing material for a designated hazardous substance, the insolubilizing material and method: making it possible to conduct treatment in a neutral region from start to finish to effectively insolubilize and immobilize a heavy metal or the like, which is contained in soil and the vicinity of the surface of the soil and which has adverse effects on health, by adding the insolubilizing material to the soil to mix with the soil, or spraying the insolubilizing material on the soil; and making the treated matter reusable, environmentally friendly, and neutral without fail. In order to achieve the purpose, the present invention provides an insolubilizing material for a designated hazardous substance, making it possible to conduct treatment to soil so that the soil does not reach a strongly basic region of a pH of 11 or more from start to finish, the insolubilizing material containing: a water-soluble aluminum compound not being strongly basic and not being amorphous; and at least one concomitant component selected from the group consisting of calcium compounds, magnesium compounds, and phosphate compounds each not being strongly basic.

Insolubilizing material for specific hazardous substance and method for insolubilizing specific hazardous substance with same

'A gypsum-based embedding material' is provided with which favorable casting can be conducted not only in the case where a conventional wax pattern is used, but also, in particular, in the case where a resin pattern different from the conventional wax pattern in disappearance temperature and disappearance behavior is used, and with which, although being a 'gypsum-based embedding material', occurrence of cracks, breakage, or the like in a mold is suppressed even when casting is conducted by &#x201c;rapid heating&#x201d; excellent in treatment efficiency. The gypsum-based embedding material composition for casting comprising, as main components, calcined gypsum as a binder, cristobalite and quartz as heat-expandable refractory materials, and a non-heat-expandable refractory material having an average particle diameter of 5 to 20 &#x3bc;m, the blending amount of the non-heat-expandable refractory material in 100 parts by mass of the main components being 10 to 25 parts by mass.

Gypsum-based embedding material composition for casting

The object of the present invention is to provide an embedding material composition for casting that makes it possible to conduct a favorable casting in the case where casting is conducted using a resin pattern that is different from a conventional wax pattern in disappearance temperature and disappearance behaviors through 'rapid heating' excellent in treatment efficiency. The present invention relates to an embedding material composition for casting not using a heat-expandable refractory material as a main component, comprising: a binder; and a non-heat-expandable refractory material having an average particle diameter of 5 to 20 &#x3bc;m as main components, in which a content of the binder is 25 to 40 parts by mass and a content of the non-heat-expandable refractory material is 60 to 75 parts by mass in the case where the total amount of the main components is 100 parts by mass, and the present invention also relates to a casting process using the embedding material composition for casting.

Casting investment composition and casting process using same

Provided is a coloring agent composition to be added to a gypsum-containing raw material powder constituting a gypsum product and to be used for coloring the gypsum product, the coloring agent composition being a powder containing a pigment, calcined gypsum, and amorphous silica. A process for producing the coloring agent composition includes a first step of mixing a pigment, calcined gypsum, and amorphous silica to obtain a mixed powder. Use of the coloring agent composition makes it possible to easily produce gypsum products such as a powder and a hardened body that are excellent in colorability.

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Tokyo, Japan

Kenichi Sugano