Process for making ceramic resistor materials

专利名称：Process for making ceramic resistor

materials

发明人：Peter G. Fuller,Hans A. Stoeckler申请号：US05/574768申请日：19750502公开号：US03983077A公开日：19760928

摘要：A process for making barium titanate based materials and the like of positivetemperature coefficient of resistivity having desirable and precisely predeterminedthermal and electrical properties utilizes low cost starting materials and convenient andeconomical processing steps. Titanium dioxide powder is placed in suspension in anaqueous medium with dissolved compounds of barium and other selected materials whilethe pH of the medium is regulated within selected limits, whereby barium and otherselected ions are adsorbed in predetermined ratio by suspended titanium dioxideparticles and whereby water-soluble contaminants in the starting materials are placed insolution. An aqueous carbonate solution is then commingled with the titanium dioxidesuspension in a controlled manner to form a precipitate which incorporates titaniumdioxide and desired relative proportions of carbonates of barium and other selectedmaterials in a homogenous mixture. The precipitate is filtered from the aqueous mediumfor effecting separation of the water soluble contaminants from the precipitate. Theprecipitate is subsequently dried and calcined and is preferably combined with a binderand fired for forming ceramic resistor elements.

申请人：TEXAS INSTRUMENTS INCORPORATED

代理人：John A. Haug,James P. McAndrews,Russell E. Baumann

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