SU1070867A1 - Method of producing lead titanate powder - Google Patents

Abstract

1. A method for producing titanium oxide titanium and glut or lead lead powder of titanium sulfate, comprising preparing a mixture of powders of the starting components, roasting and grinding, characterized in that, in order to obtain lead titanate for the solder stekpokpotsitsionnym material providing hermetic soldering, roasting is carried out at a temperature of .750-1000 ° C with a holding time of 10-50 h., titanium oxide of the following granulometric composition is used, wt.%: 45-60 μm65 2-45 μm90-98 less than 2 grams or lead lead - next particle size th composition, wt. %: 50-100 µm $ 1 4-40 µm.89-95 less than 4 (L 2. Method POP.1, characterized in that the molar ratio of PbO to TiOj in the mixture is 1.0.11, 05.

Description

The invention relates to methods for producing titanates, preferably lead titanate (TC), and can be used in the manufacture of filler for glass composite materials for hermetic soldering of electronic equipment.

A known method for producing powdered TC by calcining titanyloxapates, lead titanyl tartrates, isolated from aqueous solutions in the form of the corresponding compounds.

A significant disadvantage of this method is the use of drogic and scarce oxalic and tartaric acids.

A well-known method of obtaining

00 powder TC calcination together

O5 precipitated from aqueous solutions of compounds of titanium and lead, for example,

hydroxides, taken in the ratio necessary to obtain the TC.

However, the implementation of this method requires a special stage of preparation of solutions of titanium and lead compounds, neutralization of solutions and washing water under production conditions, as well as complex instrumentation.

In addition, the well-known method of obtaining a powdered TC includes the evaporation or pulverization of liViHbiK rasporov nitrates or others (titanium and alloy and titanium alloy specified). Relation followed by calcination of the obtained powder. This process has the disadvantages of the previous method and, furthermore, the additional disadvantage that nitrogen oxides are neutralized. The closest to the technical essence and the achieved result of the invention is a method for synthesizing TC from titanium oxide and lead lead or lead red lead, which is burning the mixture of these materials. However, this method does not allow to obtain a TC with a particle size of more than 0.5 µm, which makes it unsuitable for use as a filler of a low-melting stack when forming a glass composite material, since particles of a vehicle less than 2 µm in size tend to aggregate and, when introduced into the glass composite material, when melted, bunches prevent the soldering of parts. The aim of the invention is to obtain lead titanate for soldering glass composite material The purpose is achieved by the fact that in the conventional method of obtaining titanium powder and lead from titanate oxide and lithium oxide or minium lead, preparation of the mixture of powders of the starting components, roasting and grinding. Calcination is carried out at a temperature of 7501000 ° C with a yield of 10-50 h. Using titanium oxide of the following particle size distribution, May, 45-60. 2-45 μm90-UZH less than 2 μm 65%,: a gulp or minium lead trace of a grain size distribution wt. 50-100 microns: 1 4-40 microns 89-95% less than 4 When. This molar ratio of PbO to the mixture is 1.01-1.05. The angular limits of the granulometric composition of titanium oxide and flat srittsovogog (lead red lead) provide the vehicle with the necessary quality with a particle size in the range of 5–45 μm, 4i o allows to obtain glass composite material, ensuring hermetic soldering. If titanium oxide grains with a size of less than 2 microns are used in an amount of more than 5%, the spreadability of the glass composition material deteriorates and no tight sealing takes place. When using titanium oxide grains with a ball size of 45-60 µm in an amount of more than 5%, unreacted lead oxide in an amount of more than 1 wt.% Remains in the TS, which is unacceptable, since the process of melting and soldering of the glass composite material leads to the interaction of lead oxide. with organic binder, part of the paste for applying glass coating on the part, accompanied by the swelling of the melted layer of glass composite material and the violation of tightness during soldering. When using lead grains of lead or red lead less than 4 microns in an amount of more than 10%, clumping of these materials occurs, the homogeneity of the charge for synthesis of TS deteriorates, the amount of unreacted lead oxide increases, and the integrity of soldering is impaired. In the presence of lead grains of lead or of red lead, more than 50-100 µm in the amount of 1%, the amount of unreacted lead oxide increases and the soldering tightness is disturbed. The firing of the charge during the synthesis of TS is carried out at a temperature of 750-1000 °. At a firing temperature below, the amount of unreacted lead oxide in the vehicle is more than 1 wt.% And a duration of more than 50 hours is required, and at a firing temperature of more than 1000 ° C, the vehicle gets too coarse-grained and increases the duration of its grinding and, in addition, the loss of lead oxide increases due to its volatility with increasing firing temperature. The duration of the seal may be 10 hours if the average grain size of the titanium oxide is closer to the lower limit and the firing temperature approaches. In the case when the average granularity of titanium oxide approaches the upper limit and the burning temperature is 750 ° C, a drying time of 50 hours is required. An excess of lead oxide is introduced into the initial mixture, equal to the loss of evaporation during heat treatment. The molar ratio of PbO and IOL should not exceed 1.05, since in this case unreacted lead oxide may remain in an amount in excess of 1 wt.%. On the other hand, this ratio should not be less than 1.01, otherwise a mixture of reactive PbO and TiO, after volatilizing part of PbO, can reveal a lack of PbO, leading to a deviation of the TC composition from the stoichiometric one and a change in the properties of the TC. The method for producing lead titanate powder is carried out as follows. 74.3 kg of lead slab is mixed with 26.6 kg of titanium oxide TiOg (the particle size distribution for examples 1-13 is shown in the table). The resulting mixture is calcined in a chamber electric furnace in an atmosphere of air. The temperature is raised at a rate of 50-100 ° C / h, cooling at a rate of 25-50 ° C / h. The resulting TC is ground in a tar mill to a specific surface of 1300-1500 and sieved through a bito with a mesh size of 45 microns. The prepared TS powder using a well-known technology is mixed with Easy; ) with glass (| m) (1 ml of glass panes made of glass grains, covered with glass frit for sealing the ceramic body of integrated circuits of the type TOR-116, 500 chassis are made on glass composite material using puffed color leak detector according to the known method. The data of the examples are summarized in the table. As can be seen from the table, the level of tightness of the spa of a glass compositional material using the vehicle according to the method proposed does not exceed .µm.s, which ensures reliable sealing of integrated circuit (IC) housings and a low soldering temperature, which allows to maintain high explosive characteristics of the IC. It is impossible to obtain a junction of a glass-composite material using a TC, tested by a known method (prototype), because the spreading of the glass composite material is absent. The use of the proposed method for the extraction of powdered TC makes it possible to create a low temperature glass composition material It is below, providing reliable and tight connection of parts made of ceramics and metal in electronic devices, as well as in other areas of technology where similar demands are made.

Claims (2)

1. METHOD FOR PRODUCING POWDER TITANATE POWDER from titanium oxide and lead or minium lead, including the preparation of a mixture from the powders of the starting components, roasting and grinding, characterized in that, in order to obtain lead titanate for solder glass-packing material, providing hermetically sealed soldering, roasting is carried out at a temperature of .750-1000 С with holding for 10-50.4, titanium oxide of the following particle size distribution is used, May.!?: 45-60 μm 2-45 microns less than 2 microns and litharge or minium <5 90-98 έ5 screw - of the following particle size distribution, May.%: 50-100 microns 4-40 microns. less than 4 microns $ 1 89-95 <s10 2. The method according to claim 1, characterized in that the molar ratio of PbO to Ti0 ₂ in the charge is 1.011.05.