Nippon Shokubai Co., Ltd.

Nippon Shokubai Kagaku Kogyo Co., Ltd.

Toho Gas Co., Ltd.

Norikazu Aikawa

Kazuo Hata

Keijirou Takasaki

Masatoshi Shimomura

Katsuhiko Sakamoto

Shigemi Osaka

Kenji Ukai

Kouji Hisada

Nobuhisa Noda

Fumihide Tamura

Takehiko Suzuki

Masato Adachi

Hideki Imai

Koji Nishikawa

Kazuhisa Murakami

Takeshi Satake

Tetuya Yasaka

A ceramic sheet including a principal surface having particle marks is disclosed. The average width of the particle marks is 0.2 to 50 &#x3bc;m, the average depth of the particle marks along the sheet thickness direction is 0.1 to 25 &#x3bc;m, and the coefficient of variation of the widths of the particle marks is 0.23 or more.

Ceramic sheet and method for manufacturing the same

The objective of one or more embodiments of the present invention is to provide a zirconia electrolyte which has high strength and which is suitable for a solid electrolyte layer of a solid oxide fuel cell, and a method for producing a zirconia electrolyte having high strength. The zirconia electrolyte according to one or more embodiments of the present invention is characterized in essentially consisting of zirconia stabilized by one or a plurality of oxides of rare earth selected from the group of scandium, yttrium, cerium, gadolinium and ytterbium, wherein a standard deviation of pore numbers in 10 or more regions having an area of 50 &#x3bc;mand not overlapping with each other on a fracture surface is 2.5 or more.

Zirconia electrolyte and method for producing zirconia electrolyte

In at least one of principal surfaces of the electrolyte sheet for a solid oxide fuel cell of the present invention, (1) a burr height [&#x394;H (0-3)] in a first zone is 100 &#x3bc;m or less, as measured by irradiating the principal surface of the sheet with a laser beam at a pitch of 0.01 mm using a laser optical three-dimensional shape measurement device, the first zone being a zone extending between a peripheral edge of the sheet and a position 3 mm inside the peripheral edge, and (2) a ratio [&#x394;H (0.61-3)/&#x394;H (0-0.6)] of a burr height [&#x394;H (0.61-3)] in a third zone to a burr height [&#x394;H (0-0.6)] in a second zone is 0.5 or more and 2.0 or less, as calculated from the burr heights measured by irradiating the principal surface of the sheet with a laser beam at a pitch of 0.01 mm using the laser optical three-dimensional shape measurement device, the second zone being a zone extending between the peripheral edge of the sheet and a position 0.6 mm inside the peripheral edge, and the third zone being a zone extending between a position 0.61 mm inside the peripheral edge of the sheet and the position 3 mm inside the peripheral edge.

Electrolyte sheet for solid oxide fuel cell, method for producing the same, and single cell for solid oxide fuel cell including the same

The present invention relates to a method of producing a scandia-stabilized zirconia sheet. The method includes the steps of: (1) pulverizing a scandia-stabilized zirconia sintered body to obtain a sintered scandia-stabilized zirconia powder having an average particle diameter (De), determined by a transmission electron microscope, in the range of 0.3-1.5 &#x3bc;m, and an average particle diameter (Dr), determined by a laser scattering method, in the range of 0.3-3.0 &#x3bc;m, where a ratio of Dr/De is at least 1.0-2.5; (2) preparing a slurry containing the sintered scandia-stabilized zirconia powder and an unsintered zirconia powder, where a percentage of the sintered scandia-stabilized zirconia powder to a sum of the sintered scandia-stabilized zirconia powder and the unsintered zirconia powder in the slurry is at least 2 mass % and at most 40 mass %; (3) molding the slurry into a green sheet; and (4) sintering the green sheet.

Process for production of scandia-stabilized zirconia sheet, scandia-stabilized zirconia sheet obtained by the process, and scandia-stabilized zirconia sintered powder

An electrolyte sheet for solid oxide fuel batteries with mechanical strength characteristics is proposed. These characteristics may include a high and stable average value of strength, Weibull coefficient, and a high adhesion to an electrode formed on a surface thereof and hence inhibits the electrode from interfacial separation from the electrolyte sheet. The electrolyte sheet for solid oxide fuel batteries is characterized by having a plurality of concaves and/or convexes on at least one surface thereof, the concaves and convexes having base faces which are circular or elliptic or are a rounded polygon in which the vertexes have a curved shape with a curvature radius of 0.1 &#x3bc;m or larger and/or the concaves and convexes having a three-dimensional shape which is semispherical or semiellipsoidal or is a polyhedron in which the vertexes and the edges have a curved cross-sectional shape having a curvature radius of 0.1 &#x3bc;m or larger.

Electrolyte sheet for solid oxide fuel cell, method for producing the same, and cell for solid oxide fuel cell

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 &#x3bc;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.

Ceramic sheet and method of producing ceramic sheet

The present invention provides electrolyte sheets for solid oxide fuel cells, the electrolyte sheets being able to improve their adhesion to electrode films formed on both surfaces thereof and being also able to improve electric power generation characteristics of fuel cells by an increase in their electrode reaction areas. There is disclosed an electrolyte sheet for solid oxide fuel cells including a sintered sheet, wherein surface roughness of the sheet as measured by an optical and laser-based non-contact three-dimensional profile measuring system is 2.0 to 20 &#x3bc;m in Rz and 0.20 to 3.0 &#x3bc;m in Ra, and wherein a ratio of Rz of one surface (having a greater Rz and a greater Ra) to Rz of the other surface having a smaller Rz and a smaller Ra is in a range of 1.0 to 3.0, and a ratio of Ra of one surface (having a greater Rz and a greater Ra) to Ra of the other surface having a smaller Rz and a smaller Ra is in a range of 1.0 to 3.0, and a ratio of Rmax to Rz (Rmax/Rz ratio) of at least one surface is in a range of 1.0 to 2.0.

Electrolyte sheets for solid oxide fuel cell and method for manufacturing same

A single cell for SOFC operating at low temperatures is provided, including a first solid electrolyte with oxide ion conductivity at 800&#xb0; C. of 0.015 S/cm or more and bending strength of 600 MPa or more, a fuel electrode and bonded to one side of the first electrolyte, comprised of a cermet of a catalyst and a second solid electrolyte with a conductivity of 0.08 S/cm or more, and an air electrode bonded to the other side of the first electrolyte comprised of a compound of first perovskite type oxide with a third solid electrolyte. The electrodes are coated with fuel and air electrode contact layers, respectively.

Single cell for a solid oxide fuel cell

A single cell for SOFC operating at low temperatures, is provided, including a first solid electrolyte with oxide ion conductivity at 800&#xb0; C. of 0.015 S/cm or more and bending strength of 600 MPa or more, a fuel electrode and bonded to one side of the first electrolyte, comprised of a cermet of a catalyst and a second solid electrolyte with a conductivity of 0.08 S/cm or more, and an air electrode bonded to the other side of the first electrolyte comprised of a compound of first perovskite type oxide with a third solid electrolyte. The electrodes are coated with fuel and air electrode contact layers, respectively.

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 &#x3bc;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.

A ceramic sheet has a burr height on the periphery of the sheet of &#xb1;100 &#x3bc;m or less and/or a dimple height on the sheet surface of 100 &#x3bc;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 &#x3bc;m, a maximum of 0.4 to 0.8 &#x3bc;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. The ceramic sheet is very useful as, for example, a solid-electrolyte film of a solid oxide fuel cell.

Ceramic sheet and process for producing the same

The invention provides a setter which comprises a sheet ceramic containing 40% to 90% by weight of an &lsqb;NiO&rsqb; 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.

Porous ceramic sheet, process for producing the same, and setter for use in the process

The present invention provides the first package (,) for brittle sheets, which comprises the brittle sheets (,) which are placed in a state of multiple layers and the end cushioning materials (,) (,) which are larger than the outer shape of the brittle sheets (,) 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.

Package, packing method and transporting method for brittle sheets

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):

Zirconia powder, method for producing the same, and zirconia ceramics

Disclosed are a ceramics sheet which has an area of 400 cm.sup.2 or more, thickness of 0.4 mm or less, maximum waviness height of 100 .mu.m or less, and warp of 0.1% or less and in which frequency of generated cracking and breakage is 10% or less when a load-applying test and a deflection-loading test each described in the text are carried out in succession, and a flat and large ceramics sheet having an area of 600 cm.sup.2 or more and thickness of 1 mm or less. Further, disclosed is a method for producing a ceramics sheet having the characteristics described above and characterized in that in calcining a ceramics green sheet to produce a ceramics sheet, the green sheet described above is interposed between porous sheets which have bulk density corresponding to 30 to 85% of the theoretical density and in which the shrinkage rate caused by heating up to the calcining temperature of the above green sheet is 5% or less on condition that the periphery of the green sheet does not protrude from the porous sheets, and calcined.

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Himeji, Japan

Norikazu Aikawa