Abstract: The present invention relates to a ceramic sheet having uniform quality over its entire surface with a decreased number of detects such as foreign matters and flaws. When the ceramic sheet was divided into sections of 30 mm square or smaller, each divided section has 5 or less defects detected based on an image obtained with a charge coupled device (CCD) camera. The present invention also relates to a method for producing the ceramic sheet. In this method, a green sheet or a calcined sheet mainly including spherical ceramic particles having an average particle diameter of 0.1 to less than 5 ?m was used as a spacer. By using this spacer, the green sheet for ceramic sheet slides smoothly on the spacer surface when it shrinks in baking, and the friction resistance between the green sheet for ceramic sheet and the spacer is lowered. In this manner, the method of the present invention can mass-produce the above-described high quality ceramic sheets.

Abstract: The present invention relates to a ceramic sheet having uniform quality over its entire surface with a decreased number of detects such as foreign matters and flaws. When the ceramic sheet was divided into sections of 30 mm square or smaller, each divided section has 5 or less defects detected based on an image obtained with a charge coupled device (CCD) camera. The present invention also relates to a method for producing the ceramic sheet. In this method, a green sheet or a calcined sheet mainly including spherical ceramic particles having an average particle diameter of 0.1 to less than 5 ?m was used as a spacer. By using this spacer, the green sheet for ceramic sheet slides smoothly on the spacer surface when it shrinks in baking, and the friction resistance between the green sheet for ceramic sheet and the spacer is lowered. In this manner, the method of the present invention can mass-produce the above-described high quality ceramic sheets.

Abstract: The present invention relates to a ceramic sheet having uniform quality over its entire surface with a decreased number of defects such as foreign matters and flaws. When the ceramic sheet was divided into sections of 30 mm square or smaller, each divided section has 5 or less defects detected based on an image obtained with a charge coupled device (CCD) camera. The present invention also relates to a method of producing the ceramic sheet. In this method, a green sheet or a calcined sheet mainly including spherical ceramic particles having an average particle diameter of 0.1 to less than 5 ?m was used as a spacer. By using this spacer, the green sheet for ceramic sheet slides smoothly on the spacer surface when it shrinks in baking, and the friction resistance between the green sheet for ceramic sheet and the spacer is lowered. In this manner, the method of the present invention can mass-produce the above-described high quality ceramic sheets.

Abstract: A ceramic sheet has a burr height on the periphery of the sheet of ±100 ?m or less and/or a dimple height on the sheet surface of 100 ?m or less, as determined by irradiating the sheet with a laser beam to measure reflected light, and three-dimensionally analyzing the reflected light with a laser optical three-dimensional profiling instrument. This sheet is highly resistant to stacking-induced loads and thermal stresses. Further, when the ceramic sheet includes a zirconia ceramic partially stabilized with 2.8 to 4.5% by mole of yttria and containing 0.1 to 2% by mass of at least one dispersed reinforcing oxide, in which the grain size of the surface of the sheet has an average of 0.1 to 0.4 ?m, a maximum of 0.4 to 0.8 ?m, and a coefficient of variation of 30% or less, which grain size is determined by scanning electron microscopic observation, the ceramic sheet has satisfactory strength at room temperature and at high temperatures and satisfactory durability of strength at high temperatures.

Abstract: The invention provides a setter which comprises a sheet ceramic containing 40% to 90% by weight of an [NiO] unit; a process for producing a porous ceramic sheet containing nickel oxide and stabilized zirconia, by the use of the setter; and a porous ceramic sheet having a ratio X of a ratio Xa relative to a ratio Xb ranging from 0.85 to 1.18, where the ratio Xa is a ratio of an X-ray diffraction peak intensity of the (200) line of nickel oxide relative to an X-ray diffraction peak intensity of the (111) line of the stabilized zirconia on one side of the sheet, and the ratio Xb is a ratio of an X-ray diffraction peak intensity of nickel oxide in the (200) line relative to an X-ray diffraction peak intensity of the (111) line of the stabilized zirconia on the other side, where the ceramic sheet is mainly produced by the process.

Abstract: The present invention provides the first package (10) for brittle sheets, which comprises the brittle sheets (12) which are placed in a state of multiple layers and the end cushioning materials (20) (20) which are larger than the outer shape of the brittle sheets (12) and whose elasticity range from 2 to 100 mm and which are placed at both ends of the brittle sheets of lamination. The present invention also provides the second package for brittle sheets, which comprises the brittle sheets which are placed in a state of multiple layers, and the side cushioning material whose proof compressive load is not less than 1960 N in vertical direction and not less than 98 N in lateral direction and which is placed at the side of the said brittle sheets of lamination.

Abstract: A zirconia powder has an average particle diameter in a range from larger than 0.5 .mu.m to 0.8 .mu.m, and particles of 90 volume percent of the zirconia powder having a diameter of 1.5 .mu.m or smaller. Using this zirconia powder, a zirconia ceramics having uniform quality can be produced. The zirconia powder of the present invention can be efficiently produced by wet-milling a raw material powder using balls under a condition satisfying the following mathematical relation (I):1.times.10.sup.12 .ltoreq.(W.sub.1.sup.2 .div.W.sub.2).times.(.omega..sup.2 .div.d).times.T.ltoreq.1.times.10.sup.14 (I)where W.sub.1 is the weight (g) of balls, W.sub.2 is the weight (g) of the raw material powder, .omega. is the peripheral velocity (cm/min) at outer periphery of a rotor, d is the diameter (cm) of a milling chamber, and T is the milling time (min).