JPS58199717A - Manufacture of germanate - Google Patents

Abstract

PURPOSE:To economically manufacture a fine-grained germanate of high purity having a uniform composition by reacting an alkoxide of a bivalent metal with a germanium alkoxide and by hydrolyzing the reaction product. CONSTITUTION:An alkoxide of a bivalent metal such as Ba, Sr, Ca, Ni or Cu is mixed with a germanium alkoxide preferably in an org. solvent such as benzene, and the mixture is reacted at about 0-100 deg.C. An alkaline aqueous soln. is added to the reaction product to hydrolyze the product at about 0-100 deg.C. Thus, a germanate is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to a method for producing a germanate of a divalent metal. In particular, the present invention relates to a method for producing germanate, which is suitable for modifying materials such as dielectrics.

[Description of prior art]

Conventionally, germanates such as barium germanate (BaGe01) have a low melting point, so if they are added to ceramic dielectric materials such as barium titanate (BaTiO,), the dielectric material can be sintered at a lower temperature. It is thought that it can be tied together.

There are two conventional methods for this addition: The first method is to add necessary amounts of barium salt such as barium carbonate (Bacon) and germanium oxide (GeO2), and perform calcination, pulverization, and firing to cause a reaction.

The second method is to synthesize a germanate such as BaGe01 in advance by mixing and firing the upper barium salt and Ge, and after pulverizing this, it is added to the ceramic material and fired. It's a method.

According to these conventional methods, especially in the first method, Ba
O and Ge01 do not necessarily distribute or react uniformly in ceramics, and it is difficult to stabilize their properties. In addition, both the first and second methods have the disadvantage that impurities are likely to be mixed in from the grinding device during grinding, resulting in deterioration of the properties.

In recent years, electronic components have been required to be smaller and have more advanced characteristics, and the raw material powder used for them has therefore become more required than ever to have uniform composition and high-purity fine particles. ing. In manufacturing processes, there is also an increasing interest in producing materials using as little energy as possible.

(Objective of the Invention) The present invention solves the above-mentioned drawbacks, and it is possible to produce germanate (a) in a uniform and desired composition, (a) in highly pure and fine particles, and (c) at a low cost with less energy. Another object of the present invention is to provide a method for producing germanate that can be produced.

[Summary of the invention]

The first feature of the present invention is a step of mixing and reacting a divalent metal alkoxide and germanium alkoxide,
A method for producing a germanate salt includes a step of hydrolyzing the reaction product to obtain a germanate salt.

Note that it is preferable that the alkoxide of the divalent metal and the germanium alkoxide are reacted in a state in which they are dissolved in an organic solvent.

Further, the reaction temperature between the divalent metal alkoxide and the germanium alkoxide is preferably θ°C to 100°C.

In addition, the reaction temperature for hydrolysis to obtain germanate is θ
It is preferable that it is 100 degreeC to 100 degreeC.

Further, it is preferable to obtain a germanate by hydrolysis with an alkaline aqueous solution.

Moreover, the above divalent metals are Ba, Sr+CaJg+Pb+Zn
+Co+l'In.

Preferably, it is one or more metals selected from Cd, Ni, and Cu.

The second feature of the present invention is the step of mixing and reacting a divalent metal alkoxide and germanium alkoxide, and hydrolyzing this reaction product to produce a hydrous germanate and/or an amorphous germanate. and heating the hydrous germanate and/or amorphous germanate to obtain an anhydrous and/or crystalline germanate.

Note that the heating temperature of the amorphous germanate is preferably 400° C. or higher and lower than the decomposition start temperature of the germanate.

As used herein, alkoxide refers to a compound in which the hydrogen atom of the OB group of alcohol is replaced with a metal atom.

〔supplementary explanation〕

The present invention will be further explained below.

In the present invention, a germanate of a divalent metal is produced using an alkoxide as a starting material.In the present invention, it is first necessary to produce an alkoxide of a divalent metal and germanium. This divalent metal is Ba.

Sr+Ca, Mg+Pb, Zn+Co+Mn+CdtN
Preferably, the metal is one or more metals selected from i and Cu.

In particular, divalent metals such as Ba, Sr+Ca, and Mg have high reactivity with alcohol, so they can be directly reacted with alcohol to produce alkoxides as shown in the following general formula (2).

Ga+2 ROHM (OR)i + H2...-...
・−・−・■ (However, H is a divalent metal. The same applies below.
) Heating may be used to promote this alkoxide production reaction. In particular, Mg has a slow reaction with alcohol, so a catalyst such as 12. HgCh may be added, but this may prevent contamination of impurity ions and Care must be taken as release may occur.

This reaction between metal and alcohol proceeds from the surface of the metal to the inside, but the reaction may be slowed down because the alkoxide produced covers the metal surface. In order to prevent this, it is preferable to add benzene or other dissolving medium.

Divalent metals Pb, Zn, and Ge are produced by other methods because it is difficult to directly react these metals with alcohol.

In the case of pb, lead acetate (Pb(CH
3COO)t) and sodium alkoxide (Na0R)
It is preferable to synthesize lead alkoxide from and using an exchange reaction.

Pb (CH3COO)1 + 2 NaOR-Pb
(OR)* +2 CHiCOONa −−−・−■Z
In the case of n, zinc chloride (ZnC12
) and sodium alkoxide (Na0R).

ZnCl2+ 2 Na0R-+Zn (OR)t +
2 NaCl ---■ Also, in the case of Ge, germanium halides, especially germanium tetrachloride (GIBC14
) is recommended. To synthesize germanium alkoxide from GeC1+, it is best to use anhydrous ammonia as shown in the following general formula (2).

GeCl4+ 4 ROB + 4 NH3−→Ge
(0R)4 + 4 NH4C1−−−−−−−−−
■When producing this alkoxide, preferred alcohols include methanol, ethanol, propatool, butanol, etc. The type of alcohol used is largely related to the reactivity when producing the alkoxide, but the produced alkoxide can be used in the present invention. The type of alkyl group in the alkoxide is not essentially important when used as a starting material.

The starting materials for this alkoxide are metals, alcohols,
All metal salts have the characteristic that their purity can be increased by relatively easy physical or chemical methods, and they do not contain any unnecessary ions, so alkoxides synthesized from these metal salts as starting materials are especially difficult to purify. Even if this is not done, impurities can be easily reduced to 0.1% or less. In order to further increase the purity of the alkoxide, the solid alkoxide is recrystallized, and the liquid alkoxide is subjected to distillation or the like.

Divalent metal alkoxide h(OR″
), germanium alkoxide Go(OR)a, or their organic solvent solutions are mixed to the desired composition, and then decarboxylated distilled water, dilute ammonia water, or other alkaline aqueous solution is gradually added to perform hydrolysis. A white powder precipitate is formed.

If this is separated by filtration, germanate is obtained.

Here, there is no difference in the properties of the product □ whether distilled water or alkaline aqueous solution is used for hydrolysis, but germanium isopropoxide is more easily hydrolyzed when hydrolyzed in alkaline conditions. Because it is faster, the formation of germanate is also faster. In order to make this alkaline state, in addition to hydrolyzing with an alkaline aqueous solution, an alkali alkoxide, an amine, etc. may be added to the alkoxide solution to make it alkaline in advance.

The reaction between the divalent metal alkoxide and germanium alkoxide is preferably carried out in a solvent. Suitable organic solvents include benzene, alcohol, hexane, etc. If the reaction temperature is set to be higher than the boiling point of the solvent, the reaction can be carried out under pressure in a pressure vessel.

0 It is preferred that the reaction temperature of both alkoxides does not exceed 100°C for most alkoxides.

Although it is not necessary to carry out the reaction by cooling, a desirable reaction temperature is 0°C to 100°C. A particularly desirable reaction temperature is 4
It is 0°C to 100°C.

Moreover, the reaction temperature for hydrolysis is preferably 0°C to 100°C. Further, hydrolysis is not limited to being carried out in aquatic plants, but can also be carried out in aqueous ammonia or other alkaline aqueous solutions.

According to the method of the present invention, the germanate obtained by the reaction may be obtained as a hydrate or an anhydride depending on the reaction conditions, the blending ratio of the raw materials used, the type of divalent metal used, etc. In some cases, it may be obtained in an amorphous form, or in a crystalline form, or these forms may coexist; however, regardless of which form it is obtained, when added as a modifier for dielectrics, etc. There is no change in the properties of the dielectric material, etc.

When obtained as a hydrate, it can be easily converted into an anhydride by heating or drying as necessary.

1 Even when obtained in an amorphous state, a crystalline germanate can be easily obtained by heating. The heating temperature is preferably 400° C. or higher and lower than the decomposition temperature of the germanate, but it can also be obtained at a lower temperature or by storm heating. The temperature for this crystallization varies depending on the type of divalent metal, reaction conditions, etc. For example, if the divalent metal is Ba, 8
However, crystalline germanate can be obtained at a heating temperature of 400°C for Sr and 800°C for Mg.

The heating atmosphere in this case is air, neutral, oxidizing, or reducing atmosphere.

The germanate in the final form is preferably an anhydrous germanate when used, but it does not necessarily have to be in an anhydrous state when the ceramic material is added. It can also be used as an anhydrous germanate.

In either case, when the germanate is obtained directly by the above reaction or in the case where the germanate is obtained by heating, the obtained germanate has a 0.0. It is a fine particle with a particle size of O2N2.1μ. Furthermore, since the heat treatment temperature for crystallizing the germanate is lower than the conventional firing temperature of 1000° C. or higher, it is easy to loosen the aggregates. In addition, the germanate obtained by chemical analysis is a highly pure substance with impurities of 0.1% or less, and the ratio of germanium atoms to divalent metal atoms (M/Ge) is M/Ge =
1, the product is M/Ge=0.98~1
．． 02 is confirmed.

〔Effect of the invention〕

As described above, according to the present invention, a divalent metal alkoxide and a germanium alkoxide are reacted and hydrolyzed to obtain a germanate. It has the excellent effect of being able to be produced uniformly and at a low cost with less energy by using a low temperature reaction process of 1000° C. or higher.

3 [Explanation based on Examples] Next, the present invention will be explained more specifically using Examples.
The gist of the present invention is not limited to the following examples.

(Example 1) High purity Ba metal 20.0g, high purity Sr metal 12.0g.
8 g of high-purity Mg metal and 3.5 g of high-purity Mg metal were taken, and these metals and 45 g of dehydrated isopropanol were placed in 200 ml of benzene and reacted at 80° C. while refluxing. A benzene solution of the metal isopropoxide is obtained in about 2 to 24 hours in each case with H2 evolution. Furthermore, by dissolving 431.2 g of anhydrous GeCl, a special grade reagent, in 200 ml of benzene along with 70 g of isopropanol, and passing dry ammonia gas through this solution,
NH4Cl began to be produced, and ammonia gas began to be discharged from the reaction vessel in about 1 hour, indicating that germanium alkoxide production had ended. generated N)
14 cl is separated by filtration to obtain a benzene solution of germanium alkoxide. The divalent metal alkoxide 4 and the germanium alkoxide thus obtained were each mixed in an atomic ratio of 1.
The mixture was mixed so that the mixture was refluxed at 80° C. for 1 hour or more. Next, while refluxing, 15 s+1 of 10N ammonia water was added dropwise little by little to form a white precipitate. After separating this precipitate by filtration, 1
A powder was obtained by drying for 0 hours.

The properties of the obtained powder were examined by X-ray diffraction, differential thermal analysis, and thermogravimetric analysis. Also, this powder is 400.600.80
The mixture was heated at different temperatures from 0°C to 1000°C, and the structure of the germanate formed was confirmed by X-ray diffraction.

Table 1 shows the results of X-ray diffraction analysis.

From Table 1, germanate represented by MGeOi crystallizes at different temperatures depending on the type of divalent metal (Ha, Sr, Mg), but it forms an anhydrous crystal at a temperature of 400°C to 800°C. I know it will happen.

Furthermore, when the particle size of the obtained germanate powder was measured using an electron microscope, it was found to be 0. They were fine particles with a diameter of 1 to 0.1 μm. Furthermore, as a result of chemical analysis, there were no impurities.
A highly pure substance of 1% or less, its atomic ratio is M/Ge=
It was 0.98-1.02.

5 Table 1 6 (Example 2) 6.7 g of high-purity Na metal was taken, added to 67 g of dehydrated ethanol, and reacted to synthesize sodium ethoxide, which was then injected with special grade zinc chloride (ZnCl2) 19
．． Zinc ethoxide was obtained by adding 8 g and heating under reflux.

The obtained zinc ethoxide and the germanium isopropoxy obtained in Example 1 are mixed so that the atomic ratio becomes Zn/Ge=2, and the mixture is reacted under reflux at about 80°C.

Next, 15+++1 decarboxylated distilled water was added dropwise little by little while the mixture was being refluxed, and a white precipitate was formed.

When this powder was measured in the same manner as in Example 1, it was found that Zn2G
It was found that crystals of e 04 were obtained.

(Example 3) Sodium ethoxide is synthesized in the same manner as in Example 2. And special grade lead acetate (Pb (CI43 COO)2)
47, Ig was added and heated under reflux to obtain lead ethoxide.

The obtained lead ethoxide and the Ge1 flumanium isoproboxide obtained in Example 1 were mixed at an atomic ratio of Pb/Ge=
1 and reflux reaction at about 80"C.

Then, while refluxing, 15 ml of decarbonated distilled water was added dropwise little by little, and a white precipitate formed.

When this powder was measured in the same manner as in Example 1, the products shown in Table 2 were obtained.

Table 2 8 Procedural amendment July 26, 1980 Patent Order No. 82877 3 of 1983, Relationship to the case of the person making the amendment Patent applicant Address 5-1 Marunouchi-chome, Chiyoda-ku, Tokyo Name Name Mitsubishi Mining and Cement Co., Ltd. Representative Kobayashi Blindness 4, Agent, 1: 6, Number of inventions increased by amendment None 8, Contents of amendment (1) Page 9, line 13 of the specification ``...Impurity 0.1% or more of impurities is corrected to 111 of impurities of 0.1% or more.

(2) Specification, page 1O, line 8 to line 9 of the same page “-
111・-Germanium isopropoxide−・−・−
・” is replaced with “・・−・−・−Germanium alkoxide・
−・・−・” is corrected.

(3) Last line of page 12 of the specification'
-m--'' is corrected to [--1--J by anhydrous and/or crystalline germanate by heating.

Claims (8)

[Claims] (1) A method for producing a germanate salt, which includes a step of mixing and reacting a divalent metal alkoxide and a germanium alkoxide, and a step of hydrolyzing the reaction product to obtain a germanate salt. (2) The method for producing a germanate salt according to claim 111, in which a divalent metal alkoxide and germanium alkoxide are reacted in a state dissolved in an organic solvent. (3) The method for producing a germanate salt according to claim 11 or (2), wherein the reaction temperature of the divalent metal alkoxide and germanium alkoxide is θ°C to 100°C. (4) Production of a germanate salt according to any one of claims (1) to (3), wherein the reaction temperature for obtaining the germanate salt by hydrolysis is 0°C to 100°C. Method. (5) A method for producing a germanate salt according to any one of claims 11 to (4), wherein the germanate salt is obtained by hydrolysis with an alkaline aqueous solution. (6) Divalent metal is Ba, Sr+ Ca, Mg+ P
b+ Zn+ Co, Mn+ CcL Ni and C
The method for producing a germanate salt according to any one of claims 1 and 1 to (5), wherein the metal is one or more metals selected from u. (7) a step of mixing and reacting a divalent metal alkoxide and germanium alkoxide; a step of hydrolyzing this reaction product to obtain a hydrous germanate and/or an amorphous germanate; A method for producing a germanate salt, the method comprising heating an acid salt and/or an amorphous germanate salt to obtain an anhydrous and/or crystalline germanate salt. (8) The method for producing a germanate salt according to claim (7), wherein the heating temperature of the amorphous germanate salt is 400° C. or higher and lower than the decomposition start temperature of the germanate salt.