公开(公告)号：US4960551A

公开(公告)日：1990-10-02

申请号：US273811

申请日：1988-11-21

申请人： Takamitsu Eonomoto ,  Hiroshi Ueda ,  Midori Kawahara ,  Naoki Okada ,  Noboru Murata

发明人： Takamitsu Eonomoto ,  Hiroshi Ueda ,  Midori Kawahara ,  Naoki Okada ,  Noboru Murata

IPC分类号： C04B35/468 ,  C04B35/472 ,  H01C7/02

CPC分类号： C04B35/4684 ,  C04B35/472 ,  H01C7/02

摘要： A modified lead barium titanate ceramic which has a fundamental composition of (Ba.sub.1-x-y Sb.sub.y Pb.sub.x)TiO.sub.3, where x is not greater than 0.9 and usually not smaller than 0.6 and y is from 0.001 to 0.1, and has a high positive temperature coefficient of resistivity (PTCR) over a range of temperature higher than about 350.degree. C. at the lower boundary, is produced by using a metal salt of an organic acid such as lead titanate salt of oxalic acid as the source of Pb and by adding at least one of BaCO.sub.3, SiO.sub.2, BN and TiO.sub.2 to the raw materials of the above fundamental composition. After thermally decomposing the organic acid metal salt the mixture of the raw materials including the additive(s) is compacted and sintered. By this method the sintering is achieved with good reproducibility and with little dissipation of lead, and the obtained titanate ceramic is good and durable in the PTCR characteristics and hence is useful as the material of a PTC thermistor functioning at medium-to-high temperatures.

摘要翻译： 具有（Ba1-x-ySbBx）TiO3的基本组成的改性的铅钛酸钡陶瓷，其中x不大于0.9且通常不小于0.6，y为0.001至0.1，并且具有高的正温度系数 通过使用诸如草酸的钛酸铅的有机酸的金属盐作为Pb的来源，并且至少加入至少在下边界处于高于约350℃的温度范围内的电阻率（PTCR） 一种BaCO3，SiO2，BN和TiO2为原料的上述基本成分。 在分解有机酸金属盐之后，将包含添加剂的原料的混合物压实并烧结。 通过这种方法，以良好的再现性和铅的少量耗散实现烧结，并且所得钛酸陶瓷在PTCR特性中是良好和耐用的，因此可用作在中 - 高温度下工作的PTC热敏电阻的材料。

公开(公告)号：US5219811A

公开(公告)日：1993-06-15

申请号：US841210

申请日：1992-02-27

申请人： Takamitsu Enomoto ,  Midori Kawahara ,  Noboru Murata ,  Hiroshi Ueda ,  Naoki Okada

发明人： Takamitsu Enomoto ,  Midori Kawahara ,  Noboru Murata ,  Hiroshi Ueda ,  Naoki Okada

IPC分类号： C04B35/468 ,  H01C7/02

CPC分类号： C04B35/4684 ,  H01C7/025

摘要： To produce a modified barium titanate ceramic which is semiconductive and sufficiently high in breakdown voltage and has a low specific resistance at room temperature and a high positive temperature coefficient (PTC) of resistance, the invention provides a powder composition comprising (A) a basic mixture consisting of 45-85 mol % of BaTiO.sub.3 powder, 1-20 mol % of SrTiO.sub.3 powder, 5-20 mol % of CaTiO.sub.3 powder and 1-20 mol % of PbTiO.sub.3 powder, (B) a source of a dopant element such as Nb, Sb, Y, La or Ce to render the ceramic semiconductive, (C) a source of Mn such as MnC.sub.2 O.sub.4 and/or a source of Cu such as CuO added such that the total amount of Mn and Cu is not more than 0.06 mol % on the basis of the quantity of the mixture (A) with proviso that the amount of Mn is not more than 0.025 mol % and (D) SiO.sub.2 amounting to 0.1-2.0 mol % on the basis of the quantity of the mixture (A). The BaTiO.sub.3 powder and the SrTiO.sub.3 powder are produced by calcining BaTiO(C.sub.2 O.sub.4).sub.2 and SrTiO(C.sub.2 O.sub.4).sub.2, respectively, and in each of these powders very fine primary particles agglomerate to constitute porous and coarse secondary particles (about 100-200 .mu.m). The PbTiO.sub.3 powder may be produced by calcining PbTiO(C.sub.2 O.sub.4).sub.2 so as to have nearly the same structure as the BaTiO.sub.3 and SrTiO.sub.3 powders. The aimed ceramic is produced by compacting the powder composition into a green body and sintering it at 1300.degree.-1400.degree. C.

摘要翻译： 为了制备半导体且足够高的击穿电压并且在室温下具有低电阻率和高正电阻系数（PTC）的改性钛酸钡陶瓷，本发明提供一种粉末组合物，其包含（A）基本混合物 包括45-85mol％的BaTiO 3粉末，1-20mol％的SrTiO 3粉末，5-20mol％的CaTiO 3粉末和1-20mol％的PbTiO 3粉末，（B）掺杂元素的源如Nb ，Sb，Y，La或Ce，以形成陶瓷半导体，（C）Mn的源如MnC 2 O 4和/或Cu源如CuO，使得Mn和Cu的总量不大于0.06mol 基于混合物（A）的量，基于混合物的量（A），Mn的量不大于0.025mol％，（D）SiO 2为0.1-2.0mol％，基于混合物（A）的量 ）。 通过煅烧BaTiO（C2O4）2和SrTiO（C2O4）2分别制备了BaTiO3粉末和SrTiO3粉末，在这些粉末中，非常细的初级颗粒聚集形成多孔和粗糙的二次颗粒（约100-200μm） ）。 PbTiO 3粉末可以通过煅烧PbTiO（C 2 O 4）2来制备，以具有与BaTiO 3和SrTiO 3粉末几乎相同的结构。 目标陶瓷通过将粉末组合物压实成生坯并在1300-140℃下烧结而制备。