JP2006176367A - Method for producing carbonate crystal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing carbonate crystals which have high aspect ratios and small sizes and can be dispersed in a monodispersed state. <P>SOLUTION: The method for producing the carbonate crystals is characterized by producing the carbonate crystals having aspect ratios of ≥2.5 and an average value of the major axis of ≤1 μm by reacting a metal ion source containing at least one kind of metal ion selected from Sr<SP>2+</SP>ion, Ca<SP>2+</SP>ion, Ba<SP>2+</SP>ion, Zn<SP>2+</SP>ion, and Pb<SP>2+</SP>ion and a carbonic acid source in a liquid having a pH value of ≥9.0 and including an aggregation preventing agent. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing small-size and monodisperse carbonate crystals having a high aspect ratio.

Conventionally, carbonates (for example, calcium carbonate) have been widely used in the fields of rubber, plastics, papermaking, etc. However, in recent years, carbonates with high functionality have been developed one after another, and particle shapes and particles have been developed. Depending on the diameter, etc., it is used for multiple purposes and multiple purposes.
Examples of the crystal form of the carbonate include calacite, aragonite, and vaterite. Among these, aragonite is acicular and is useful for various applications in that it has excellent strength and elastic modulus.

As a method for producing carbonate, a method of producing carbonate by reacting a solution containing carbonate ions and a solution of chloride, a method of producing carbonate by reacting chloride and carbon dioxide gas, etc. are generally used. Known. Further, as a method for producing an acicular carbonate having an aragonite structure, for example, in the former method, a reaction between a solution containing carbonate ions and a chloride solution is performed under ultrasonic irradiation (see Patent Document 1). ) and a method of introducing carbon dioxide into Ca (OH) ₂ water slurry, pre-Ca (OH) in ₂ water slurry, placed needle aragonite crystals as a seed crystal, the seed crystal only in a certain direction growth A method (see Patent Document 2) is proposed.
However, in the method for producing a carbonate described in Patent Document 1, not only the length of the obtained carbonate is as large as 30 to 60 μm, but also a carbonate having a wide particle size distribution width and controlled to a desired particle size. There is a problem that cannot be obtained. Moreover, even if the carbonate manufacturing method described in Patent Document 2 is used, only large particles having a length of 20 to 30 μm can be obtained.

  By the way, in recent years, as a material for optical components used in general optical components such as spectacle lenses and transparent plates and optical components for optoelectronics, in particular, optical equipment for recording sound, video, character information, etc. There is an increasing tendency to use polymer resins. The reason for this is that polymer optical materials (optical materials made of polymer resins) are generally lighter, cheaper and more workable and mass-productive than other optical materials (eg, optical glass). A point is mentioned. The polymer resin also has an advantage that it is easy to apply a molding technique such as injection molding or extrusion molding.

  However, when a conventional polymer optical material that has been conventionally used is subjected to a molding technique to produce a product, the resulting product has a property of exhibiting birefringence. A polymer optical material having birefringence is not particularly problematic when used for an optical element that does not require relatively high accuracy, but in recent years, optical articles that require higher accuracy have been required. For example, in a write / erase type magneto-optical disk, birefringence is a big problem. That is, in such a magneto-optical disk, a deflection beam is used for the reading beam or the writing beam, and if there is a birefringent optical element (for example, the disk itself, a lens, etc.) in the optical path, the reading, Alternatively, the writing accuracy is adversely affected.

  Therefore, for the purpose of reducing birefringence, a non-birefringence optical resin material using a polymer resin and inorganic fine particles having different birefringence codes has been proposed (see Patent Document 3). The optical resin material is obtained by a technique called a crystal dope method. Specifically, a large number of inorganic fine particles are dispersed in a polymer resin, and a molding force is applied from the outside by stretching or the like. A molecular resin bond chain and a large number of inorganic fine particles are oriented substantially in parallel, and the birefringence caused by the orientation of the polymer resin bond chain is reduced by the birefringence of inorganic fine particles having different signs.

  Thus, in order to obtain a non-birefringent optical resin material using the crystal doping method, inorganic fine particles that can be used for the crystal doping method are indispensable. It is recognized that carbonates of the above can be used particularly suitably, and small-size and monodisperse carbonate crystals having a high aspect ratio are desired.

JP 59-203728 A US Pat. No. 5,164,172 WO 01/25364 pamphlet

  An object of the present invention is to solve the conventional problems and achieve the following objects. That is, an object of the present invention is to provide a method for producing a small-size and monodispersed carbonate crystal having a high aspect ratio.

As a result of intensive studies in view of the above problems, the present inventor has obtained the following knowledge. That is, a liquid containing a coagulation inhibitor, a metal ion source containing at least one metal ion selected from Sr ²⁺ ions, Ca ²⁺ ions, Ba ²⁺ ions, Zn ²⁺ ions, and Pb ²⁺ ions, and a carbonic acid source. It is a finding that when reacted in a medium, a small-size and monodisperse carbonate crystal can be obtained with a high aspect ratio.

The present invention is based on the above knowledge of the present inventor, and means for solving the above problems are as follows. That is,
<1> A metal ion source containing at least one metal ion selected from Sr ²⁺ ions, Ca ²⁺ ions, Ba ²⁺ ions, Zn ²⁺ ions, and Pb ²⁺ ions, and a carbonate source at a pH of 9.0 or more. A method for producing a carbonate crystal comprising reacting in a liquid containing an anti-aggregation agent to produce a carbonate crystal having an aspect ratio of 2.5 or more and an average value of a major axis of 1 μm or less. is there.
<2> The method for producing a carbonate crystal according to <1>, wherein the aggregation inhibitor is any one of a polyalkylene oxide compound and a polyvinyl compound.
<3> The method for producing a carbonate crystal according to any one of <1> to <2>, wherein the aggregation inhibitor is any one of polyethylene oxide and polyvinyl alcohol.
<4> The method for producing a carbonate crystal according to any one of <1> to <3>, wherein a metal ion source and a carbonic acid source are simultaneously added and reacted in a liquid.
<5> The method for producing a carbonate crystal according to any one of <1> to <4>, wherein the metal ion is at least one metal ion selected from Sr ²⁺ ion, Ca ²⁺ ion, and Ba ²⁺ ion. It is.
<6> From the above <1> to <1>, wherein the metal ion source is any one of hydroxides and chlorides, and the carbonate source is at least one of sodium carbonate, potassium carbonate, ammonium carbonate, and carbon dioxide gas. 5> The method for producing a carbonate crystal according to any one of the above.
<7> The method for producing a carbonate crystal according to any one of <1> to <6>, wherein the metal ion source and the carbonate source are reacted in the presence of an alcohol.
<8> The method for producing a carbonate crystal according to any one of <1> to <7>, wherein a metal ion source is used in an amount of 0.05 mol / L or more.
<9> The method for producing a carbonate crystal according to any one of <1> to <8>, further including a drying step of drying the carbonate crystal obtained by the reaction between the metal ion source and the carbonate source.
In the method for producing a carbonate crystal described in <1> to <9>, a small-size and monodisperse carbonate crystal having a high aspect ratio can be efficiently and easily formed.
Further, the carbonate crystal produced by the method for producing a carbonate crystal of the present invention can be used for multiple purposes and for many purposes, and can also be applied to a non-birefringent optical resin material.

  According to the present invention, the conventional problems can be solved, and a method for producing a small-size and monodispersed carbonate crystal having a high aspect ratio can be provided.

(Method for producing carbonate crystals)
In the method for producing carbonate crystals of the present invention, the metal ion source and the carbonate source are reacted at a pH of a predetermined value or higher in a liquid containing an anti-aggregation agent, and the aspect ratio is 2.5 or more. And the carbonate crystal | crystallization whose particle | grain major axis is 1 micrometer or less is manufactured.

-Metal ions-
The metal ion is not particularly limited as long as it contains a metal ion and can be appropriately selected according to the purpose. For example, Sr ²⁺ ion, Ca ²⁺ ion, Ba ²⁺ ion, Zn ²⁺ ion, and Pb ²⁺ And ions. Among these, Sr ²⁺ ions, Ca ²⁺ ions, and Ba ²⁺ ions, which are alkaline earth metal ions, are particularly preferable from the viewpoint of reactivity. Those that react with the carbonic acid source to form a carbonate having any form of calacite, aragonite, vaterite, and amorphous are preferred, and those that form a carbonate having an aragonite-type crystal structure are particularly preferred.
The crystal structure of the aragonite-type is represented by CO ₃ ^2- unit, to form a carbonate which the CO ₃ ^2- unit has any shape are laminated needle and rod-like. For this reason, when the carbonate is stretched in an arbitrary direction by a stretching process described later, crystals are arranged in a state where the major axis direction of the particles coincides with the stretching direction.
Table 1 shows the refractive index of the aragonite type mineral. As shown in Table 1, the carbonate having an aragonite type crystal structure has a large birefringence δ, and therefore can be suitably used for doping a polymer having orientation birefringence.

The metal ion source is not particularly limited as long as it includes at least one metal ion selected from Sr ²⁺ ions, Ca ²⁺ ions, Ba ²⁺ ions, Zn ²⁺ ions, and Pb ²⁺ ions. For example, at least one nitrate, chloride, hydroxide and the like selected from Sr, Ca, Ba, Zn, and Pb can be used. Of these, hydroxides and chlorides are particularly preferable from the viewpoint of reactivity.

The metal ion source preferably contains at least one of NO ₃ ⁻ , Cl ⁻ , and OH ⁻ . Therefore, specific examples of the metal ion source include Sr (NO ₃ ) ₂ , Ca (NO ₃ ) ₂ , Ba (NO ₃ ) ₂ , Zn (NO ₃ ) ₂ , Pb (NO ₃ ) ₂ , SrCl ₂ , CaCl ₂ , BaCl ₂ , ZnCl ₂ , PbCl ₂ , Sr (OH) ₂ , Ca (OH) ₂ , Ba (OH) ₂ , Zn (OH) ₂ , Pb (OH) ₂ , and hydrates thereof Preferably mentioned.

-Carbonate source-
The carbonic acid source is not particularly limited as long as it generates CO ₃ ^2- ion, and can be appropriately selected according to the purpose. For example, sodium carbonate [Na ₂ CO ₃ ], lithium carbonate [Li ₂ CO ₃ ], potassium carbonate [K ₂ CO ₃ ], cesium carbonate [Cs ₂ CO ₃ ], ammonium carbonate [(NH ₄ ) ₂ CO ₃ ], sodium hydrogen carbonate [NaHCO ₃ ], carbon dioxide, urea [(NH ₂ ) ₂ CO] and the like are preferable. Among these, sodium carbonate, potassium carbonate, ammonium carbonate, and carbon dioxide are particularly preferable from the viewpoint of reactivity.

-Reaction method-
The method of reacting in the liquid is not particularly limited and may be appropriately selected depending on the purpose. For example, from the viewpoint of reactivity, the metal ion source and the carbonate source are simultaneously mixed in the liquid. The method of adding and reacting is mentioned.
Specifically, as a method of adding the metal ion source and the carbonic acid source and reacting them simultaneously in a liquid, a double jet method can be mentioned.

-Double jet method-
The double jet method is a method in which the metal ion source and the carbonic acid source are added and reacted on the reaction liquid surface or in the liquid, respectively. For example, as shown in FIG. In this method, the liquid A containing the ion source and the liquid B containing the carbonic acid source are simultaneously injected into the liquid C, and these are reacted in the liquid C.

  The addition rate of the metal ion source and the carbonic acid source by the double jet method is not particularly limited and can be appropriately selected according to the purpose. However, it is preferably faster, for example, the total amount of the additive substance is 1 min. The addition rate is preferably such that the addition is completed within the range. The molar addition rate is preferably determined so as to be the stoichiometric ratio of the final product. In the present invention, the equimolar rate is most preferable.

The double jet method can be performed using, for example, a double jet reaction crystallizer. This apparatus has a stirring blade in a reaction vessel, and is provided with a nozzle for supplying a raw material solution in the vicinity of the stirring blade. The number of nozzles is two or more. Then, the metal ion source (the A liquid) and the carbonic acid source (the B liquid) supplied from the nozzle become uniform at high speed by the mixing action by the stirring blade, and instantaneously and uniformly react in the C liquid. It is possible.
In addition, as a stirring speed in a double jet method, 500-1500 rpm is preferable.

-PH-
The pH in the liquid in which the metal ion source and the carbonate source are reacted is preferably in an alkaline atmosphere from the viewpoint of easily obtaining needle-like or rod-like carbonate crystals, specifically 9 or more. Is preferable, and 9.5 or more is more preferable. If the pH is less than 9, the transparency of the resulting carbonate crystals may be lowered.
Further, when the metal ion source contains an OH group, it is preferable to maintain the pH from the start to the end of the reaction. When the metal ion source does not contain an OH group, for example, It is preferable to carry out the reaction by adding a chemical that forms an alkaline atmosphere, such as NaOH, so as to achieve the above pH.

-Anti-agglomeration agent-
When the ionic strength is increased during the formation of carbonate crystals, the anti-aggregation agent loses the repulsive force due to the electric double layer between crystal particles, tends to cause aggregation, and is difficult to prepare efficiently at a high concentration. Therefore, it is added to prevent the aggregation of crystal particles. By adding the anti-aggregation agent, the crystal particles are stably brought into a colloidal state and effectively prevented from aggregating with each other.
The anti-aggregation agent is not particularly limited as long as it can be adsorbed on crystal particles, has a steric repulsion force, and can prevent aggregation of the crystal particles, and may be either a natural product or a synthetic compound.
Preferred examples of the natural product include gelatin, starch, agar, carrageenan and the like.
Preferred examples of the synthetic compound include polyalkylene oxide compounds and polyvinyl compounds. Among these, polyalkylene oxide compounds are particularly preferable.
Examples of the polyalkylene oxide compound include polyethylene oxide, polypropylene oxide, polyoxyethylene polyoxypropylene, polyoxyethylene-9-octadecenylamine, polyoxyethylene-9-octadecenyl ether, and polyoxyethylene dodecyl. Examples include ether, sodium polyoxyethylene dodecyl ether sulfate, sodium polyoxyethylene dodecyl ether phosphate, polyoxypropylene octadecyl ether, and among these, polyethylene oxide is particularly preferable.
Examples of the polyvinyl compound include polyvinyl alcohol, polyvinyl pyrrolidone, polymethyl vinyl ether, and polyvinyl imidazole. Among these, polyvinyl alcohol is particularly preferable.
In addition, for example, polyacrylamide compounds, polystyrene compounds, and the like are also preferable.
Examples of the polyacrylamide compounds include polyacrylamide and poly N-isopropylacrylamide.
Examples of the polystyrene compound include sodium polystyrene sulfonate.

The addition amount of the aggregation inhibitor is not particularly limited as long as the above object can be achieved, but is preferably 0.1 to 10.0% by mass, and preferably 0.5 to 5.0% by mass with respect to the metal ion source. % Is more preferable.
The timing for adding the anti-aggregation agent is not particularly limited as long as it is present when the volume of the crystal particles is increased and the above object can be achieved. It is preferable to add it before increasing the number.
There is no restriction | limiting in particular as temperature at the time of the said aggregation inhibitor addition, Although it can select suitably according to the temperature which the aggregation inhibitor to add melt | dissolves, 0-50 degreeC is preferable and 5-40 degreeC is more preferable. .

-Addition concentration of metal ion source and carbonate source-
The addition concentration of the metal ion source and the carbonate source is not particularly limited and may be appropriately selected depending on the intended purpose. The addition concentration of the metal ion source is 0.05 mol / L from the viewpoint of reactivity. Is preferable, and 0.10 mol / L or more is more preferable.

-Reaction temperature-
There is no restriction | limiting in particular as temperature in the liquid with which the said metal ion source and the said carbonic acid source are made to react, but it is 0-50 degreeC from a viewpoint which dissolves an aggregation inhibitor in a metal ion source. Preferably, 5-40 degreeC is more preferable.

-Other processes-
When the metal ion source and the carbonate source are reacted, it is preferable to react in the presence of an organic solvent. The type of the organic solvent is not particularly limited and may be appropriately selected depending on the intended purpose. For example, methanol, ethanol, 1-propanol, isopropyl alcohol, 2-aminoethanol, 2-methoxyethanol, acetone, Preferred examples include tetrahydrofuran, 1,4-dioxane, N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, 1,3-dimethyl-2-imidazolidone, dimethyl sulfoxide and the like. These may be used individually by 1 type and may use 2 or more types together. Among these, alcohols are particularly preferable, and methanol, ethanol, isopropyl alcohol, and 2-aminoethanol are more preferable from the viewpoints of reactivity and easy availability of materials.
Moreover, when a carbonate crystal is obtained by the reaction of the metal ion source and the carbonate source, it is preferable to have a drying step of drying the carbonate crystal.
The method for drying carbonate crystals in the drying step is not particularly limited and may be appropriately selected. For example, it is preferable to dry after removing the solvent by filtration or the like.

-Properties of carbonate-
The carbonate crystals obtained by the method for producing carbonate crystals of the present invention have the following properties.

--Aspect ratio--
The aspect ratio needs to be 2.5 or more, preferably 3.0 or more, and more preferably 4.0 or more. When the aspect ratio is less than 2.5, for example, when applied to rubber or plastic, the effect of improving strength and elastic modulus may not be obtained depending on the usage.

--Average length of major axis--
The average value of the major axis needs to be 1.0 μm or less, preferably 0.9 μm or less, and more preferably 0.8 μm or less. If the average value of the major axis exceeds 1.0 μm, it may be greatly affected by scattering, and the adaptability to optical applications may be reduced.

但し、上記数式（１）において、ｒは長径の平均値、ｎは長径を測定した粒子の数、ｒ_ｉはｉ番目に測定した粒子の長径を表し、ｎ＝５０以上が好ましく、１００以上がより好ましい。 --Long diameter variation-
The variation in the major axis is not particularly limited, but the variation coefficient of the major axis is preferably 45% or less, and more preferably 40% or less. The major axis variation coefficient is represented by the ratio of the standard deviation of the major axis to the average value of the major axis, and is obtained by the following mathematical formula (1).

However, in the above equation (1), r is the major axis of the mean value, n represents the number of particles was measured major axis, r _i represents the major axis of the particles measured in the i-th, n = 50 or more, 100 or more More preferred.

-Application-
The carbonate crystal produced by the method for producing a carbonate crystal of the present invention has an aspect ratio of 2.5 or more and an average value of major axis of 1 μm or less, and has a shape such as a needle shape and a rod shape instead of a spherical shape. Therefore, it is useful as a plastic reinforcing material, friction material, heat insulating material, filter and the like. In particular, in a composite material subjected to deformation such as a stretched material, the strength and optical characteristics can be improved by orienting the particles.

Further, the carbonate crystal produced by the method for producing a carbonate crystal of the present invention is dispersed in an optical polymer having birefringence, and subjected to a stretching treatment so that the binding chain of the optical polymer and the carbonate crystal are substantially reduced. When oriented in parallel, the birefringence caused by the orientation of the bond chain of the optical polymer can be canceled by the birefringence of the carbonate crystal.
There is no restriction | limiting in particular as said extending | stretching process, According to the objective, it can select suitably, For example, uniaxial stretching is mentioned. Examples of the uniaxial stretching method include stretching with a stretching machine to a desired stretching ratio while heating as necessary.

  The intrinsic birefringence of a resin having birefringence is as described in “Transparent Resins So far: The World of High-Performance Optical Materials that Challenge IT” (Fumio Ide, Industrial Research Committee, First Edition) p29. Specifically, as shown in Table 2 below. From Table 2, it is recognized that many of the optical polymers have positive birefringence. In addition, when strontium carbonate is used as the carbonate crystal and added to, for example, polycarbonate as the optical polymer, the positive birefringence of the mixture can be canceled and not only zeroed, but also negative. . For this reason, it can be suitably used for an optical component, in particular, an optical element in which deflection characteristics are important and high accuracy is required.

  Examples of the present invention will be described below, but the present invention is not limited to the following examples.

但し、上記数式（１）において、ｒは長径の平均値、ｎは長径を測定した粒子の数、ｒ_ｉはｉ番目に測定した粒子の長径を表す。 Example 1
To 300 ml of an aqueous 0.25 mol / L strontium hydroxide solution as a metal ion source, 1.0 g of polyethylene oxide as an anti-aggregation agent is added and dissolved, mixed with ethanol and cooled to 35 ° C. 300 ml of an aqueous 0.10 mol / L ammonium carbonate solution was stirred and mixed for reaction. The pH in the reaction solution was 12.8.
Next, while stirring the reaction solution, excess carbon dioxide gas as a carbon dioxide source was supplied, and then the solvent was removed by filtration, followed by drying to obtain strontium carbonate crystal T-1. When this crystal was observed with a transmission electron microscope and the major axis of a plurality of particles was measured, the aspect ratio was 5.2, the major axis average was 730 nm, and the coefficient of variation obtained by the following mathematical formula (1) was 36%. there were.

However, in the above equation (1), r is the major axis of the mean value, n represents the number of particles was measured major axis, r _i represents the major axis of the particles was measured i th.

(Example 2)
To 500 ml of an aqueous solution cooled to 35 ° C. by adding 0.25 mol / L strontium hydroxide as a metal ion source, 1.0 g of polyvinyl alcohol as an aggregation inhibitor was added and dissolved, and 300 ml of ethanol was added. While maintaining this solution at 35 ° C., 0.15 mol / L strontium chloride aqueous solution as a metal ion source and 0.18 mol / L sodium carbonate aqueous solution as a carbonic acid source were simultaneously added and mixed to obtain a strontium concentration. Was adjusted to be 0.1 mol / L. The pH in the reaction solution was 12.3.
Next, after adding a 0.3 mol / L aqueous strontium hydroxide solution as a metal ion source, an excess carbon dioxide gas was supplied as a carbon dioxide source while stirring the reaction solution, and then the solvent was removed by filtration. Drying gave strontium carbonate crystals T-2. When this crystal was observed in the same manner as in Example 1, the aspect ratio was 4.7, the average major axis was 780 nm, and the variation coefficient of the major axis was 42%.

(Comparative Example 1)
In Example 2, strontium carbonate crystal H-1 was obtained in the same manner except that polyvinyl alcohol was not added. When this crystal was observed in the same manner as in Example 1, the aspect ratio was 2.1, the average value of the major axis was 1.1 μm, and the coefficient of variation of the major axis was 70%.

  From these results, the carbonate crystal production method of the present invention is obtained by reacting a metal ion source and a carbonate source in a liquid having a pH of 9.0 or more and containing an aggregation inhibitor. It was found that the salt crystal has a high aspect ratio and can be monodispersed.

The carbonate produced by the carbonate production method of the present invention has an aspect ratio of 2.5 or more and an average value of the major axis of 1 μm or less, and is not spherical, but has a shape such as a needle shape and a rod shape. It is useful as a plastic reinforcing material, friction material, heat insulating material, filter and the like. In particular, in a composite material subjected to deformation such as a stretched material, the strength and optical characteristics can be improved by orienting the particles.
Further, the carbonate (crystal) produced by the carbonate production method of the present invention is dispersed in an optical polymer having birefringence, and subjected to a stretching treatment to make the optical polymer bond chain and the carbonate substantially parallel. The birefringence caused by the orientation of the bond chain of the optical polymer can be canceled by the birefringence of the carbonate. For this reason, it can be suitably used for an optical component, in particular, an optical element in which deflection characteristics are important and high accuracy is required.

FIG. 1 is a conceptual diagram illustrating a method for producing a carbonate of the present invention by a double jet method.

Claims (9)

A metal ion source containing at least one metal ion selected from Sr ²⁺ ions, Ca ²⁺ ions, Ba ²⁺ ions, Zn ²⁺ ions, and Pb ²⁺ ions, and a carbonate source, having a pH of 9.0 or more, A method for producing a carbonate crystal comprising reacting in a liquid containing an anti-agglomeration agent to produce a carbonate crystal having an aspect ratio of 2.5 or more and an average value of major axis of 1 μm or less.   The method for producing a carbonate crystal according to claim 1, wherein the aggregation inhibitor is any one of a polyalkylene oxide compound and a polyvinyl compound.   The method for producing a carbonate crystal according to any one of claims 1 and 2, wherein the aggregation inhibitor is any one of polyethylene oxide and polyvinyl alcohol.   The method for producing a carbonate crystal according to any one of claims 1 to 3, wherein a metal ion source and a carbonate source are simultaneously added and reacted in the liquid. The method for producing a carbonate crystal according to any one of claims 1 to 4, wherein the metal ion is at least one metal ion selected from Sr ²⁺ ions, Ca ²⁺ ions, and Ba ²⁺ ions.   The metal ion source is any one of hydroxide and chloride, and the carbonate source is at least one of sodium carbonate, potassium carbonate, ammonium carbonate, and carbon dioxide gas. The manufacturing method of the carbonate crystal of description.   The method for producing a carbonate crystal according to any one of claims 1 to 6, wherein a metal ion source and a carbonate source are reacted in the presence of an alcohol.   The manufacturing method of the carbonate crystal | crystallization in any one of Claim 1 to 7 which uses a metal ion source 0.05 mol / L or more. The manufacturing method of the carbonate crystal | crystallization in any one of Claim 1 to 8 including the drying process which dries the carbonate crystal | crystallization obtained by reaction with a metal ion source and a carbonate source.

Images