Ngk Insulators, Inc.

Tetsuya Onogi

Koji Kimura

Takuji Kimura

Hidemi Nakagawa

A ceramic molded body including a ceramic powder and an organic binder includes an oxidizable ceramic powder as the ceramic powder, includes an oxidizable metal or metal compound, or is in contact with a solid body including an oxidizable metal or metal compound. In a hydrogen atmosphere, the ceramic molded body is heated to a maximum temperature set within a range of 1,100° C. to 1,400° C. at a heating rate of more than 25° C./h, is degreased at the maximum temperature, and is then cooled at a cooling rate of more than 25° C./h.

Method for degreasing shaped ceramic molded body and method for manufacturing ceramic fired body

The invention provides a ceramic green sheet having plasticity, punching property, and sinterability of satisfactory levels as well as a low percent (heat) shrinkage. In the production of a ceramic slurry serving as a raw material of the sheet, ingredients thereof are mixed under such conditions that the functional group ratio (polyol to isocyanate) is 1.5/11.5 to 11.5/11.5; the urethane resin formed from isocyanate and polyol has a repeating-unit-based molecular weight of 290 to 988; and the ratio by weight of the urethane resin to a ceramic powder falls within a range of 4.5 to 10 parts by weight of the urethane resin with respect to 100 parts by weight of the ceramic powder. A ceramic green sheet having, in well balance, all of the properties (i.e., plasticity, punching property, sinterability, and (heat) shrinkage) required for facilitating subsequent processes such as mechanical working and firing can be provided.

Ceramic green sheet and method for producing the same

The ceramic slurry is prepared by mixing a ceramic powder, a solvent, a dispersion medium, an isocyanate, a polyol, and a catalyst for accelerating a urethane reaction between the isocyanate and the polyol. A temperature-sensitive catalyst, which substantially exhibits a catalyst function only within a specific temperature range including an active temperature and higher than room temperature, is used as the catalyst. In a solidifying and drying step performed after a molding step of the slurry at room temperature, the solidification/drying temperature is set to be a high temperature within the range (within the specific temperature range) relatively close to the active temperature of the temperature-sensitive catalyst, and this temperature is maintained. Thus, the catalyst function can sufficiently be exhibited under high temperature.

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Nagoya, Japan

Tetsuya Onogi