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CN-116507588-B - Method for producing barium titanyl oxalate and method for producing barium titanate

CN116507588BCN 116507588 BCN116507588 BCN 116507588BCN-116507588-B

Abstract

A process for producing barium titanyl oxalate, characterized in that a solution (A) containing oxalic acid and a solution (B) containing a titanium source and a barium source are mixed and reacted to produce barium titanyl oxalate, wherein the A solution and the B solution are supplied to one end of a reaction liquid flow path, respectively, the A solution and the B solution are mixed in the reaction flow path, the reaction liquid is discharged from the other end of the reaction liquid flow path, and then solid-liquid separation of the reaction liquid is performed, wherein the residence time of the reaction liquid in the reaction liquid flow path is within 30 seconds, or the A solution and the B solution are supplied to one end of the reaction liquid flow path, respectively, and the A solution and the B solution are mixed at one end of the reaction liquid flow path, and the reaction liquid is moved to the other end of the reaction liquid flow path while swirling the reaction liquid is generated, and then the solid-liquid separation of the reaction liquid is performed.

Inventors

  • TANNO HIROAKI
  • Guo long Ji

Assignees

  • 日本化学工业株式会社

Dates

Publication Date
20260508
Application Date
20211112
Priority Date
20201119

Claims (7)

  1. 1. A method for manufacturing barium titanyl oxalate is characterized in that: Which is a method for producing barium titanyl oxalate by mixing and reacting a liquid A and a liquid B described below, The solution A is a solution containing oxalic acid, the solution B is a solution containing a titanium source and a barium source, In the production method, the A liquid and the B liquid are respectively supplied to one end side of a reaction liquid flow path, the A liquid and the B liquid are mixed in the reaction flow path, the reaction liquid is discharged from the other end side of the reaction liquid flow path, then solid-liquid separation of the reaction liquid is performed, The residence time of the reaction solution in the reaction solution flow path is within 30 seconds, The reactant flow is formed by an in-line mixer or a continuous flow microreactor, The solvent of the solution A is water solvent, organic solvent or mixed solvent of water and organic solvent, the organic solvent is selected from more than 1 or 2 of methanol, ethanol, propanol, butanol, diethyl ether, 1, 3-butanediol, ethylene glycol, propylene glycol, dipropylene glycol, glycerol, N-dimethylformamide and acetone, The solvent of the solution B is water.
  2. 2. The method for producing barium titanyl oxalate according to claim 1, wherein: the reaction liquid flow path is formed in the static mixer by supplying the liquid a and the liquid B to one end side of the static mixer, respectively.
  3. 3. A method for manufacturing barium titanyl oxalate is characterized in that: which is a method for producing barium titanyl oxalate by mixing and reacting a liquid A and a liquid B described below, The solution A is a solution containing oxalic acid, the solution B is a solution containing a titanium source and a barium source, The manufacturing method comprises supplying the A liquid and the B liquid to one end of a reaction liquid flow path, mixing the A liquid and the B liquid at one end of the reaction liquid flow path, moving the reaction liquid to the other end of the reaction liquid flow path while generating Taylor vortex, discharging the reaction liquid from the other end of the reaction liquid flow path, performing solid-liquid separation of the reaction liquid, The residence time of the reaction solution in the reaction solution flow path is 60 seconds or less, The solvent of the solution A is water solvent, organic solvent or mixed solvent of water and organic solvent, the organic solvent is selected from more than 1 or 2 of methanol, ethanol, propanol, butanol, diethyl ether, 1, 3-butanediol, ethylene glycol, propylene glycol, dipropylene glycol, glycerol, N-dimethylformamide and acetone, The solvent of the solution B is water.
  4. 4.A method for producing barium titanyl oxalate according to claim 1 or 3, wherein: The titanium source in the solution B is titanium tetrachloride, and the barium source is barium chloride.
  5. 5. A method for producing barium titanyl oxalate according to claim 1 or 3, wherein: The mixing temperature of the solution A and the solution B is below 75 ℃.
  6. 6. A method for producing barium titanyl oxalate according to claim 1 or 3, wherein: the average particle diameter of the barium titanyl oxalate is 1.0 μm or less.
  7. 7. A method for producing barium titanate, characterized by: Firing the barium titanyl oxalate obtained by the production method according to any one of claims 1 to 3.

Description

Method for producing barium titanyl oxalate and method for producing barium titanate Technical Field The present invention relates to a method for producing barium titanyl oxalate useful as a raw material for functional ceramics such as dielectrics, piezoelectrics, optoelectronic materials, semiconductors, sensors, and the like. Background Currently, barium titanate is generally produced by a solid phase method, a hydrothermal synthesis method, an alkoxide method, an oxalate method, or the like. In the solid phase method, since the solid phase method is produced by a dry method in which constituent raw material powders and the like are mixed and the mixture is heated at a high temperature, the obtained powder forms aggregates exhibiting irregular shapes, and further, high-temperature firing is required to achieve desired characteristics. Although the hydrothermal synthesis method has the advantage of good powder properties, it is industrially disadvantageous because it is complicated in synthesis steps and uses an autoclave, and therefore, it is inferior in productivity, and the cost for producing the powder is high. In addition, the alkoxide method is difficult to handle the starting material, is expensive, and is industrially disadvantageous. Barium titanate obtained by the oxalate method can be produced at a low cost as compared with the hydrothermal synthesis method and the alkoxide method, and has a characteristic of having a uniform composition as compared with barium titanate produced by the solid phase method. As a conventional oxalate method, there is a method in which a titanium source such as titanium tetrachloride, a barium source such as barium chloride, and oxalic acid are reacted in a solvent such as water to obtain barium titanyl oxalate, and then the barium titanyl oxalate is fired (for example, see patent documents 1 to 3). Prior art literature Patent literature Patent document 1 Japanese patent application laid-open No. 2005-500239 Patent document 2 Japanese patent application laid-open No. 2010-202610 Patent document 3 Japanese patent application laid-open No. 2013-63867 Disclosure of Invention Technical problem to be solved by the invention However, since barium titanyl oxalate obtained in the above patent document generates barium titanate at a firing temperature of 700 ℃ or higher, the crystallinity is low at the time of generation of barium titanate, but some degree of grain growth occurs. When such barium titanyl oxalate is fired at a high temperature, the barium titanyl oxalate is large in size even if it is highly crystallized, and thus the barium titanyl oxalate cannot satisfy the characteristics as a functional ceramic raw material. Accordingly, an object of the present invention is to provide a method for producing barium titanyl oxalate, which can produce barium titanate having a small particle size and high crystallinity. Technical scheme for solving technical problems The inventors of the present invention have made intensive studies in view of the above-described circumstances, and as a result, have found that by supplying a solution containing oxalic acid (solution a) and a solution containing a titanium compound and a barium compound (solution B) to one end side of a reaction liquid passage formed in an in-line mixer, a microreactor or the like, respectively, mixing the solution a and the solution B in the reaction passage, and discharging the reaction liquid from the other end side of the reaction liquid passage, a fine barium titanyl oxalate can be obtained by shortening the mixing time of the solution a and the solution B, carbon dioxide thermally decomposed during firing of such fine barium titanyl oxalate is liable to escape, and the temperature at which barium titanate is produced can be reduced, and by producing barium titanate at a low temperature, barium titanate can be highly crystallized at a low temperature as compared with the prior art, so that the grain growth of barium titanate can be suppressed, and thus fine-grained and highly crystallized barium titanate can be obtained as compared with the prior art, and completed the present invention. Further, as a result of intensive studies in view of the above-described circumstances, the inventors of the present invention have found that by supplying a solution containing oxalic acid (solution a) and a solution containing a titanium compound and a barium compound (solution B) to one end side of a reaction liquid flow path, respectively, mixing the solution a and the solution B while generating a vortex in the reaction flow path, and discharging the reaction liquid from the other end side of the reaction liquid flow path, it is possible to obtain fine barium titanyl oxalate by rapidly bringing the reaction raw materials in the solution a and the solution B into contact with each other, carbon dioxide thermally decomposed during firing of such fine barium titanyl oxalate is liable to escape, and the temperature at