Low-temperature sinterable ceramic composition
AssigneeNgk Spark Plug Co., Ltd.
InventorsTakashi Kato, Minato Ando
Life of this patent
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Abstract
A low-temperature sinterable ceramic composition comprising 1 to 20% by weight of Al.sub.2 O.sub.3, 15 to 50% by weight of SiO.sub.2, 0 to 5% by weight of MgO, 3 to 18% by weight of CaO, 0 to 5% by weight of TiO.sub.2, 1 to 8% by weight of B.sub.2 O.sub.3, 0 to 2% by weight of Li.sub.2 O, 20 to 80% by weight of at least one of zircon, mullite and spinnel, and 1 to 12% by weight of a fluoride selected from CaF.sub.2, MgF.sub.2, LiF, AlF.sub.3, MnF.sub.2, BaF.sub.2 and SrF.sub.2.
Claims2
A low-temperature sinterable ceramic composition consisting essentially of 1 to 20% by weight of Al.sub.2 O.sub.3, 15 to 50% by weight of SiO.sub.2, 0 to 5% by weight of MgO, 3 to 18% by weight of CaO, 0 to 5% by weight of TiO.sub.2, 1 to 8% by weight of B.sub.2 O.sub.3, 0 to 2% by weight of Li.sub.2 O, 20 to 80% by weight of at least one zircon, mullite and spinel, and 1 to 12% by weight of a fluoride selected from CaF.sub.2, MgF.sub.2, LiF, AlF.sub.3, MnF.sub.2 and SrF.sub.2, wherein said composition has a sintering temperature of not more than 1,000.degree. C., a flexural strength of at least 2,100 kg/cm.sup.2, a dielectric constant of not more than 8 at 1 MHz, and a coefficient of thermal expansion of not more than 8.times.10.sup.-6 /.degree.C.
Dependencies are inferred from the claim text.