CN103708541A - Method for preparing barium nonatitanate by liquid-phase process - Google Patents

Abstract

The invention discloses a method for preparing Ba2Ti9O20 by a liquid-phase process, which comprises the following steps: adding tetrabutyl titanate into ethylene glycol while stirring, wherein the volume ratio of the ethylene glycol to the tetrabutyl titanate is (4-8):1; adding hydrochloric acid to regulate the pH value of the solution to 2-6; adding pure water under such acidic conditions to perform hydrolysis, thereby obtaining a clear solution, wherein the mole ratio of the pure water to the tetrabutyl titanate is 4:1; adding barium acetate and 0-10 wt% boric acid, and completely dissolving to form a stable and uniform sol, wherein the mole ratio of the barium acetate to the tetrabutyl titanate is 2:9; converting the sol into a gel at 80-150 DEG C; calcining at 500-900 DEG C to obtain Ba2Ti9O20 powder; and carrying out pressure molding, and sintering at 1180-1280 DEG C to obtain the Ba2Ti9O20 dielectric ceramic material. The XRD (X-ray diffraction) proves that the main crystal phase of the synthetic material is Ba2Ti9O20 and the expected effect is achieved.

Description

A kind of method of Liquid preparation methods nine titanium barium

Technical field

The present invention relates to a kind of ceramic composition that composition is feature of take, be specifically related to a kind of dielectric ceramic material Ba with good dielectric properties ₂ti ₉o ₂₀(be called for short B ₂t ₉) preparation method.

Background technology

Microwave technology grew up since 50 years last century, contacted more and more closelyr with our life, had been widely used in the communications field.Microwave-medium ceramics is mainly in microwave circuit, to do insulated substrate and manufacture microwave dielectric resonator etc.

B ₂t ₉it is the material (specific inductivity is about 35～40) of a kind of medium specific inductivity and Q value.Because application band is wide, material system low price obtains extensive concern.

At present, B ₂t ₉preparation method often adopt solid-phase synthesis and liquid phase method (or being called wet chemistry method).Sol-gel method of the present invention is exactly a kind of conventional liquid phase method.

Although adopt traditional solid phase method to synthesize B ₂t ₉method comparison simple, easily operation, but due at needed TiO ₂and BaCO ₃near component, exist the compound of other components of a lot of better heat stability such as Ba ₆ti ₁₇o ₄₀, BaTi ₃o ₇, BaTi ₄o ₉, BaTi ₅o ₁₁, and Ba ₄ti ₁₃o ₃₀, therefore adopt the stoichiometric ratio of the necessary strict control starting raw material of the method and the quantity of a reaction parameter, and adopt the method to need higher calcining temperature and sintering temperature, generally more than 1300 ℃, even up to 1400 ℃.Although adopt higher sintering temperature still to be many times also difficult to obtain single-phase B ₂t ₉.Simultaneously solid phase method has that energy consumption is large, efficiency is low, powder not evenly, is easily sneaked into the shortcomings such as impurity.

And liquid phase rule can obtain the homogeneity of reaction material on molecular level, chemical reaction is more easily carried out, therefore at lower temperature, can synthesize required goods.People once adopted multiple liquid phase method to synthesize B ₂t ₉, as by the aikylide of barium and titanium in ethanolic soln at 1100 ℃ continuous hydrolysis 543h make single-phase B ₂t ₉; Ethylene glycol solution with barium carbonate solution and barium obtains B by burning under the environment of citric acid ₂t ₉presoma, then by the B obtaining ₂t ₉thereby presoma at 1200 ℃, calcine the synthetic single-phase B of 110h ₂t ₉; With BaCl ₂and TiCl ₄for starting raw material is at H ₂o ₂in situation about existing with ammoniacal liquor, adopt coprecipitation method synthetic single-phase B at 900 ℃ ₂t ₉etc..But these methods are complex process mostly, and experiment flow is long, and the work output of product is lower.

Summary of the invention

Object of the present invention, is to overcome the shortcoming and defect of prior art, and a kind of Liquid preparation methods B is provided ₂t ₉method.

The present invention is achieved by following technical solution.

A kind of Liquid preparation methods Ba ₂ti ₉o ₂₀method, there are following steps:

(1) ethylene glycol is put into beaker, in the situation that constantly stirring, adding butyl (tetra) titanate, the volume ratio of ethylene glycol and butyl (tetra) titanate is 4～8:1; Then drip hydrochloric acid, the pH value of solution is adjusted into 2～6; The pure water that to add with butyl (tetra) titanate mol ratio under this acidic conditions be 4:1 makes butyl (tetra) titanate hydrolysis, obtains settled solution;

(2) according to Ba ₂ti ₉o ₂₀metering ratio, the barium acetate that to add with butyl (tetra) titanate mol ratio after the butyl (tetra) titanate complete hydrolysis of step (1) be 2:9, then add the boric acid of 0～10wt% mass percent, then constantly stir, until solid matter all dissolves, form the colloidal sol of stable and uniform;

(3) step (2) gained colloidal sol is put in 80～150 ℃ of baking ovens, is incubated and makes it be converted into gel in 2～6 hours;

(4) step (3) gained gelinite is calcined at 500～900 ℃, be incubated 1 hour, obtain B ₂t ₉powder;

(5) by step (4) B ₂t ₉the tackiness agent that adds 6wt% in powder, under 10MPa, extrusion forming is base substrate, then at 1180～1280 ℃ sintering, be incubated 2 hours, make the fine and close B with good dielectric properties ₂t ₉dielectric ceramic material.

The sintering temperature of described step (5) is 1250 ℃.

Beneficial effect of the present invention:

Through X-ray diffraction (XRD), prove, the principal crystalline phase of synthesized powder is Ba ₂ti ₉o ₂₀, reached desired result.Obtained goods are tested electrical property after by silver, and the dielectric properties of material are good, and its specific inductivity is 27.6, and dielectric loss is 2.4 * 10 ^-4.

Accompanying drawing explanation

Fig. 1 is X-ray diffraction (XRD) figure of the specific embodiment of the invention.

Embodiment

The raw materials used analytical reagent that is of the present invention.

Specific embodiment is as follows:

(1) ethylene glycol is put into beaker, in the situation that constantly stirring, adding butyl (tetra) titanate, the volume ratio of ethylene glycol and butyl (tetra) titanate is 6:1; Then drip hydrochloric acid, the pH value of solution is adjusted into 3; The pure water that to add with butyl (tetra) titanate mol ratio under this acidic conditions be 4:1 makes butyl (tetra) titanate hydrolysis, obtains settled solution;

(2) according to B ₂t ₉metering ratio, the barium acetate that to add with butyl (tetra) titanate mol ratio after the butyl (tetra) titanate complete hydrolysis of step (1) be 2:9, then add the boric acid of 4wt% mass percent, then constantly stirs, until solid matter all dissolves, forms the colloidal sol of stable and uniform;

(3) colloidal sol of step (2) is put in 110 ℃ of baking ovens, is incubated and makes it be converted into gel in 2 hours.

(4) step (3) gained gel is calcined at 800 ℃, be incubated 1 hour, obtain B ₂t ₉powder.

(5) by step (4) B ₂t ₉the tackiness agent that adds 6wt% in powder, under 10MPa, extrusion forming is base substrate, then in 1250 ℃ of sintering, is incubated 3 hours, makes the fine and close B with good dielectric properties ₂t ₉dielectric ceramic material.

Obtained goods are tested electrical property after by silver, and the dielectric properties of material are good.Its specific inductivity is 27.6, and dielectric loss is 2.4 * 10 ^-4.

Fig. 1 is that as can be seen from Figure, the principal crystalline phase of synthesized powder is Ba through X-ray diffraction (XRD) figure ₂ti ₉o ₂₀, reached desired result.

Each processing parameter that the present invention is cited and bound value thereof and interval value can be realized the present invention, then this is not illustrated one by one.

Claims (2)

1. a Liquid preparation methods Ba ₂ti ₉o ₂₀method, there are following steps:

(1) ethylene glycol is put into beaker, in the situation that constantly stirring, adding butyl (tetra) titanate, the volume ratio of ethylene glycol and butyl (tetra) titanate is 4～8:1; Then drip hydrochloric acid, the pH value of solution is adjusted into 2～6; The pure water that to add with butyl (tetra) titanate mol ratio under this acidic conditions be 4:1 makes butyl (tetra) titanate hydrolysis, obtains settled solution;

(2) according to Ba ₂ti ₉o ₂₀metering ratio, the barium acetate that to add with butyl (tetra) titanate mol ratio after the butyl (tetra) titanate complete hydrolysis of step (1) be 2:9, then add the boric acid of 0～10wt% mass percent, then constantly stir, until solid matter all dissolves, form the colloidal sol of stable and uniform;

(3) step (2) gained colloidal sol is put in 80～150 ℃ of baking ovens, is incubated and makes it be converted into gel in 2～6 hours;

(4) step (3) gained gelinite is calcined at 500～900 ℃, be incubated 1 hour, obtain B ₂t ₉powder;

(5) by step (4) B ₂t ₉the tackiness agent that adds 6wt% in powder, under 10MPa, extrusion forming is base substrate, then at 1180～1280 ℃ sintering, be incubated 2 hours, make the fine and close B with good dielectric properties ₂t ₉dielectric ceramic material.

2. a kind of Liquid preparation methods Ba according to claim 1 ₂ti ₉o ₂₀method, it is characterized in that, the sintering temperature of described step (5) is 1250 ℃.