JP3362239B2 - Method for producing plate-like calcium carbonate - Google Patents

Description

Detailed Description of the Invention

[0001]

[Object of the Invention]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing plate-like calcium carbonate having a plate-like shape, and more specifically to efficiently produce plate-like calcium carbonate having a uniform plate-like shape from calcium hydroxide. It is about the method.

[0002]

2. Description of the Related Art As is well known, calcium carbonate is used for papermaking.
Widely used as a filler for rubber, resins, paints, foods, etc.

Calcium carbonate is roughly classified into two types, that is, heavy calcium carbonate produced by crushing limestone and precipitated calcium carbonate produced by chemically reacting a carbon source and a calcium source. It is roughly divided into.

[0004] Heavy calcium carbonate has a particle size limit of micron order due to the capability of a crusher, and its shape is also angular and irregular. If the particle size is not classified, a narrow particle size range can be obtained. Since there are problems such as not being available, its field of use is limited.

On the other hand, the precipitated calcium carbonate is typically a suspension (slurry) of calcium hydroxide (hereinafter referred to as lime milk) containing carbon dioxide or a carbon dioxide-containing gas (hereinafter referred to as carbon dioxide gas). Depending on the carbon dioxide compounding method of introducing and reacting, 0.03 to 0.06 μm or 1
Since it has a uniform particle shape and a particle diameter of ˜3 μm and is easy to manufacture, its field of use is wide.

[0006] Here, the following will be discussed focusing on the crystal system and particle shape of calcium carbonate. Three isomorphic polymorphs of calcite, aragonite, and vaterite are known for crystal engineering. The calcite type is the most stable and has a cubic shape, a spindle shape, a chain shape, or the like. The aragonite type is the second most stable after the calcite type, and has a columnar shape, a needle shape, or the like. The above two crystal systems are currently manufactured and sold.
On the other hand, the vaterite type, which basically has a spherical shape, is unstable in crystal engineering, and in the presence of water, the particle shape is easily changed at the same time as the crystal transition to calcite or aragonite. It is not manufactured because of the cost of stabilizing the surface coating and the like.

In the above-mentioned calcium carbonate particle shape, recently, a plate-like shape other than the above-mentioned shape has been strongly required. Similar to calcium carbonate, this is because kaolinite-based fillers and pyrophyllite-based fillers, which are used in large quantities as inorganic fillers for papermaking, rubber, resins, paints, etc., are composed of hexagonal plate-like or scale-like crystals. This is because the calcium carbonate has excellent properties, and in order to substitute it, a plate-shaped calcium carbonate is indispensable.

As a method for producing the above-mentioned plate-shaped calcium carbonate, several reports have recently been made, but the involved reactions are complicated, a large amount of heat energy is used, and the product is expensive. The current situation is that industrial production has not yet been reached.

At present, calcium hydroxide, basic calcium carbonate, and calcium carbonate are under development and research as lime-related plates including calcium carbonate.

As the method for producing the plate-like calcium hydroxide described above, a method obtained by a solution reaction of calcium chloride and sodium hydroxide (Gypsum and Lime Society Journal "Gypsum and Lime" No. 189), hydration of calcium oxide A method in which a water-soluble calcium salt is added to the reaction solution and the mixture is aged (JP-A-58-
176124), and as a method for producing the plate-like basic calcium carbonate described above, a method of partially carbonizing lime milk to obtain basic calcium carbonate (Japanese Patent Publication No. 62-321).
30, JP-A-61-219715 and JP-A-62-1
13718) and the like. However, these methods have considerable problems as industrial materials such as expensive raw materials, shape changes when water is present, and high pH in water.

On the other hand, calcium carbonate is a sufficient material for solving the problems of shape change in water and high pH. As a method for producing the plate-shaped calcium carbonate described above, the first step is to react the aqueous solution of calcium hydroxide with carbon dioxide, or to react the slurry of limestone with carbon dioxide to prepare an aqueous solution of calcium hydrogen carbonate. Then, as a second step, a method is obtained by dropping or injecting into the water subjected to heating control (JP-A-63-50).
316, Journal of the Ceramic Society of Japan "Journal of the Ceramic Society of Japan" Vol. 100), and a method of carbonating plate-like calcium hydroxide or basic calcium carbonate prepared by partial carbonation of lime milk at a temperature of 200 ° C. or higher (Journal of Gypsum and Lime Society “Gypsum and Lime” No. 196).
And JP-A-61-219717).

However, these methods have problems in that the manufacturing process is complicated in two steps, mass production cannot be expected, the cost of raw materials is high, and further the consumption of heat energy is large. This is a difficult manufacturing method.

[Problems to be Solved by the Invention]

The inventors of the present invention have made diligent studies to solve the above-mentioned drawbacks found in the conventional techniques for producing plate-shaped lime-related substances, particularly plate-shaped calcium carbonate, and as a result, have found that carbon dioxide gas is added to lime milk. In introducing and carrying out the carbonation reaction, the following structural formulas (1), (2),
When a primary amine, a secondary amine, a tertiary amine, a quaternary amine compound represented by (3) or an organic amine compound which is a polymer thereof is coexistent, plate-like calcium carbonate is extremely efficiently produced. The present invention has been completed, and the present invention has been completed. It is an object of the present invention to provide a method for producing plate-like calcium carbonate which is easy to carry out a reaction operation and can be mass-produced at low cost.

[Structural formula 1] (In the formula, R ₁ is an alkyl group, an olefin group, a diolefin group or an aromatic group. R ₂ and R ₃ are a hydrogen atom or an alkyl group and may be different from each other.)

[Structural formula 2] (In the formula, R ₁ , R ₂ R ₄ and R ₅ are a hydrogen atom or an alkyl group and may be different from each other. R ₃ is an alkyl group, an olefin group, a diolefin group or an aromatic group. )

[Structural formula 3] (In the formula, R ₁ , R ₂ R ₄ , R ₅ , R ₇ and R ₈ are hydrogen atoms or alkyl groups and may be different from each other.
₃ and R ₆ are alkyl groups, olefin groups, diolefin groups or aromatic groups. n is an integer of 1 or more. )

Briefly describing the present invention, the present invention relates to a method for producing calcium carbonate by a carbonation reaction in which carbon dioxide gas is introduced into lime milk, in which reaction conditions under which basic calcium carbonate is produced during the production process of calcium carbonate. And a carbonation reaction in the presence of the organic amine compound represented by the structural formulas (1), (2), and (3), in a plate-like calcium carbonate production method. The configuration of the present invention will be described in detail below.

The present invention is a so-called carbonation compounding method in which carbon dioxide is introduced into lime milk to carry out a carbonation reaction to produce calcium carbonate. In the so-called carbonation combination method, reaction conditions for producing basic calcium carbonate in the course of the carbonation reaction. The greatest characteristic is that the organic amine compounds represented by the structural formulas (1), (2), and (3) coexist below.

Techniques using organic chemicals in the production of calcium carbonate are known in the art, for example, JP-B-48-17438 (a method for producing calcium carbonate having excellent coating physical properties) and JP-A-57-14530. Method for producing finely ground precipitated calcium carbonate, Journal of Japan Adhesion Association Vo
l. 21 No. 2 (1985) (Study on preparation of calcium carbonate in the presence of polyvinyl alcohol), JP-B-60-33764 (method for producing finely precipitated calcium carbonate), JP-A-1-252525 (method for producing calcium carbonate having a large surface area). Is disclosed in. Further, a technique of using as an organic solvent at the time of producing calcium carbonate is also known, and for example, it can be found in, for example, Journal of Japan Adhesion Association Vol. 21, No.
10 (1985) (Synthesis of calcium carbonate in methanol system and its surface properties), Oita Prefectural Industrial Research Institute, Showa 60
Fiscal Year Annual Report (Method for synthesizing vaterite-type calcium carbonate (2nd report)) Japanese Patent Publication No. 2-16244 (method for producing amorphous calcium carbonate), JP-A-4-31315 (monodispersed spherical or elliptic spherical vaterite calcium carbonate and its production Method), JP-A-5-201724 (Ethylene glycol dispersion of crystalline calcium carbonate and crystalline calcium carbonate), JP-A-5-294616 (Voterite-type calcium carbonate morphology control method / particle growth method), JP-A-5-155613. (Method for producing morphologically controlled monodisperse vaterite type calcium carbonate).

However, in the above-mentioned conventional method,
In the former case, an organic chemical is added from the initial stage of the reaction, and the shape of manufactured calcium carbonate is cubic calcium carbonate. In the latter, alcohols are used as a solvent, and the shape of calcium carbonate produced is amorphous or spherical calcium carbonate.

On the other hand, in the method for producing plate-like calcium carbonate of the present invention, under the reaction conditions for producing basic calcium carbonate and under the above structural formulas (1), (2),
The carbonation reaction is carried out in the presence of the organic amine compound shown in (3) to produce plate-like calcium carbonate.

When the organic amine compounds represented by the structural formulas (1), (2) and (3) are used under the above-mentioned reaction conditions, the present inventors efficiently produce plate-like calcium carbonate. We found a very peculiar phenomenon that it is generated, but its theoretical elucidation has not been sufficiently done.

In the present invention, the conditions for the carbonation reaction system are:
That is, the concentration of lime milk, the concentration of carbon dioxide gas and the amount of carbon dioxide gas are not regulated separately, but the reaction conditions are such that basic calcium carbonate or a mixture of basic calcium carbonate and calcium hydroxide is formed during the reaction. It is necessary to be a carbonation reaction of. Even if the organic amine compound represented by the above structural formulas (1), (2), and (3) is added to the reaction system outside these conditions, only cubic or chain-like calcium carbonate of about 0.1 μm is produced. Is.

In the present invention, since the condition that basic calcium carbonate is produced during the carbonation reaction is important, this point will be explained. Whether or not basic calcium carbonate is produced in the course of the carbonation reaction can be distinguished by the carbonation reaction rate. As described above, it is inaccurate to define the conditions for forming basic calcium carbonate by the carbonation rate because of factors such as the ratio of the amount of reacted carbon dioxide to the amount of introduced carbon dioxide and the reactivity due to the particle size of calcium hydroxide. In some cases, it happens. To specify more accurate conditions, the electrical conductivity during carbonation may be adopted. In the reaction of forming basic calcium carbonate, the carbonation rate is 6
Electric conductivity of 3.5 mS / cm from around 0%
In the reaction that is not so, the electric conductivity is already 3.5 m before the carbonation rate exceeds 60%.
A drop exceeding S / cm is observed. Therefore, as a condition for forming basic calcium carbonate, the decrease in electrical conductivity is 3.5 before the reaction before the carbonation rate exceeds 60%.
It is important to be within mS / cm.

[0021]

[0022]

[0023]

[0024]

Specific examples of the organic amine compounds represented by the above structural formulas (1), (2) and (3) include methylamine, ethylamine, propylamine, butylamine, hexylamine, heptylamine, dimethylamine and diethylamine. , Dipropylamine, dibutylamine, dihexylamine, methylethylamine, methylpropylamine, methylbutylamine, ethylpropylamine, ethylbutylamine, propylbutylamine, trimethylamine, triethylamine, tripropylamine, tributylamine, methyldiethylamine, methyldipropylamine, Methyldibutylamine, dimethylethylamine, dimethylpropylamine, dimethylbutylamine,
Diethylpropylamine, diethylbutylamine, dipropylbutylamine, methylethylpropylamine, methylethylbutylamine, methylpropylbutylamine, ethylpropylbutylamine, triethylamine,
Diisopropylamine, ethylenediamine, propanodiamine, diethylenediamine, triethylenediamine,
Diethylenetriamine, tetraethylenetetraamine,
Pentaethylene hexaamine, hexaethylene octaamine, octaethylene decaamine, hexamethylenetetramine, hexamethylenediamine, methylethyldiamine, ethylethylenediamine, dimethylethylenediamine, methylpropyldiamine, tetramethyldiamine, tetramethylhexanediamine, tetramethylphenylene Diamine, tolylenediamine, trimethylethylenediamine, phenyldiamine, diaminoheptane, dimethylenetriamine, diethylenetriamine, methyleneethylenetriamine, ethylenepropylenetriamine,
Ethylene butylene triamine, methylene propylene triamine, propylene butylene thiamine, trimethylene tetramine, triethylene tetramine, tripropylene tetramine, tributylene tetramine, dimethylene ethylene teroramine, methylene diethylene tetramine, tetraethylene pentamine, diethylene propylene tetramine, ethylene di Propylene tetramine, tetraethylene pentaamine, pentaethylene hexaamine, hexaethylene octaamine, aniline, toluidine, xylidine, naphthylamine, nitroamine, phenylenediamine, diphenylamine, diaminodiphenylamine, chrysoidine, dimethylaniline, diethylaniline, benzylaniline, creatine, methyl Benzylamine,
Examples thereof include phenylethylamine, creatine, dimethanolamine, diethanolamine, octadecyldiethanolamine, and lauryldipolyglycolamine, and these are used alone or in combination of two or more.

In the present invention, the structural formula (1),
The organic amine compounds shown in (2) and (3) are not limited to the above specific examples. In the present invention, among the above-mentioned organic amine compounds, ethylenediamine, diethylenetriamine, triethylenetriamine,
Tetraethylenepentamine is the preferred one.

In the present invention, the structural formula (1),
The organic amine compound shown in (2) and (3) may be added before or during the reaction, or both, and the substantial addition time is as follows.
The carbonation rate is between 0 and 85%, preferably between 5 and 70%. If the carbonation rate is 85% or more, 0.0
Cubic calcium carbonate of about 5 μm is produced. Here, the carbonation rate (G) is represented by the following formula (1).

[0028]

[Formula 1]

In the present invention, the amount of the organic amine compound added varies depending on the kind of the organic amine compound, but is preferably 0.01 to 20% by weight, and more preferably 0.1 to 10% by weight, based on calcium hydroxide. If it is 0.01% by weight or less, cubic or chain-like calcium carbonate of about 0.05 μm tends to be formed, and if it is 20% by weight or more, it is 10 μm.
The coarse particles are likely to be as large as m and are not economically preferable.

【Example】

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

[0031]

Example 1 400 m of lime milk with a concentration of 9 g / 100 ml
1 was adjusted to 15 ° C., and 25% carbon dioxide gas was added to 900 ml /
Blowing was started at the speed of minutes. After 45 minutes from the start of the reaction, 1.23 g of diethylenetriamine was added. When the carbonation rate at this point was measured by a conventional method, it was about 66%. At this point, 10 ml was taken out, dehydrated and dried, and the powder obtained was examined with an X-ray disintegrator. As a result, it was found to be basic calcium carbonate. After addition
The reaction was continued as it was to complete the reaction. The reaction end time was about 68 minutes from the start of the reaction. The decrease in electrical conductivity up to a carbonation rate of 60% is 1.9 m before the reaction.
It was S / cm. The carbonated lime milk is filtered, dehydrated, washed with water, washed with methyl alcohol, and then heated to 100 ° C.
Then, 48 g of calcium carbonate was obtained. When the shape of the obtained calcium carbonate was observed with a scanning electron microscope, the diameter was about 1 to 1.5 μm and the thickness was 0.1 to 0.15 μm.
It was a plate-like particle of m. A scanning electron micrograph of this product is shown in FIG.

[0032]

[Comparative Example 1] 400 m of lime milk with a concentration of 9 g / 100 ml
1.23 g of diethylenetriamine was added to 1 liter of lime milk in advance, 25% carbon dioxide gas was introduced at 2,000 ml / min, and the temperature was kept at 15 ± 1 ° C. for carbonation. After 20 minutes from the start of the reaction, 10 ml was taken out, dehydrated and dried, and the powder obtained was examined by an X-ray disintegrator. As a result, a calcite-type calcium carbonate and calcium hydroxide were in a mixed state. The reaction completion time was about 35 minutes, and as a result, about 0.04 μm cubic calcium carbonate was produced. In the carbonation reaction, the decrease in electric conductivity up to a carbonation rate of 60% was 4.6 mS / cm.

[0033]

[Comparative Example 2] The same operation as in Example 1 was carried out except that diethylenetriamine was not added. Carbonation was completed in about 68 minutes, and about 0.6 µm cubic calcium carbonate was produced. At this time, the decrease in electric conductivity up to a carbonation rate of 60% was 1.8 mS / cm. Also, the reaction start 4
When 10 ml was taken out in 5 minutes, dehydrated and dried, and the powder obtained was examined by an X-ray disintegrator, it was found to be basic calcium carbonate.

[0034]

[Comparative Example 3] The same operation as in Example 1 was carried out except that 5.23 g of triethylenetetramine hexaacetic acid was added instead of diethylenetriamine, whereby spindle-shaped calcium carbonate of about 1 to 2 µm was produced.

[0035]

Comparative Example 4 The same operation as in Example 1 was carried out except that 6.87 g of citric acid was added instead of diethylenetriamine, whereby spindle-shaped calcium carbonate of about 1 to 2 μm was produced.

[0036]

Example 2 The same operation as in Example 1 was carried out except that the lime milk concentration was 6 g / 100 ml, the reaction start temperature was 20 ° C., and 25% carbon dioxide gas was 600 ml / min.
32 g of plate-like calcium carbonate having a thickness of 1.5 μm and a thickness of 0.1 to 0.15 μm was obtained. At this time, the decrease in electrical conductivity up to a carbonation rate of 60% is 2.2 mS /
It was cm.

[0037]

[Example 3] 400 m of lime milk having a concentration of 6 g / 100 ml
1 was adjusted to 15 ° C., and 25% carbon dioxide gas was added to 300 ml /
Blowing was started at the speed of minutes. After 20 minutes from the start of the reaction, 4.46 g of triethylenetetramine was added. When the carbonation rate at this point was measured according to a conventional method, it was about 17%. Also, at this point, 10 ml
Was taken out, dehydrated and dried, and the powder obtained was examined with an X-ray disintegrator. As a result, it was found that basic calcium carbonate and calcium hydroxide were mixed. After the addition, the reaction was continued as it was to terminate the reaction. The reaction end time was about 120 minutes from the start of the reaction. The decrease in electrical conductivity up to a carbonation rate of 60% was 1.6 mS / cm based on that before the reaction. The carbonated lime milk is filtered, dehydrated, washed with water and washed with methyl alcohol, and then dried at 100 ° C. to 32
g of calcium carbonate was obtained. The shape of the obtained calcium carbonate was observed with a scanning electron microscope.
It was a plate-like particle having a thickness of 1.5 μm and a thickness of 0.1 to 0.15 μm.

[0038]

Example 4 The same operation as in Example 3 was carried out except that 3.42 g of ethylenediamine was added instead of diethylenetriamine, and the diameter was 1 to 1.5 μm and the thickness was 0.1.
.About.0.15 .mu.m plate-like calcium carbonate was produced.

[0039]

Example 5 Example 3 except that 5.42 g of tetraethylenepentamine was added instead of diethylenetriamine.
When a similar operation to that described above was performed, plate-like calcium carbonate having a diameter of 1 to 1.5 μm and a thickness of 0.1 to 0.15 μm was produced.

Also in Examples 2 to 5, formation of basic calcium carbonate was confirmed by X-ray analysis during the reaction. Further, in any of the examples, the decrease in electrical conductivity up to a carbonation rate of 60% was within 3.5 mS / cm based on the level before the reaction.

【The invention's effect】

By the method for producing plate-like calcium carbonate of the present invention, it is possible to easily produce calcium carbonate having a plate-like shape which has never been obtained. As its characteristic, first, calcium hydroxide and carbon dioxide as carbonation raw materials and a small amount of organic amine compound as an additive are used, so that it can be produced at a low manufacturing cost, and the addition time of the organic amine compound is wide. Therefore, the reaction operation is easy. Further, the plate-like calcium carbonate produced does not show a high alkali by dissolving like other plate-like calcium hydroxide or plate-like basic calcium carbonate, so that surface coating with other substances or heating and carbonation are complicated. It does not require stable stabilization. From the above viewpoints, it can be said that the plate-like calcium carbonate manufacturing method of the present invention is a manufacturing method that is easy to industrially manufacture on the premise of mass production. By the way, conventional natural plate-like compounds represented by kaolin clay, talc, and the like have been demanded to be depleted of resources. Moreover,
When it is filled in papermaking, resin, paint, rubber, etc., the product may be colored or turbid due to the inclusion of a small amount of impurities, the production area or the temporal variation. Therefore, the plate-like calcium carbonate of constant quality obtained in the present invention is extremely important as a substitute for the conventional plate-like natural compound, and a large amount of plate-like calcium carbonate of constant quality can be obtained by increasing the quantity of the substitute. The product filled with plate-like calcium carbonate can be stably produced with a constant quality and at the same time, the production cost can be reduced. Furthermore, it is expected that it will lead to the improvement of various physical properties such as the smoothness and glossiness of the surface of the product filled with plate-like calcium carbonate.

[Brief description of drawings]

FIG. 1 is a scanning electron micrograph as a substitute for a drawing, which shows the particle structure of the calcium carbonate obtained in Example 1.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hisao Sugihara 1-2-20 Nagahama-cho, Oita-shi, Oita (72) Inventor Yoshiyuki Yakushiji 3 2052, Imura, Usuki-shi, Oita (72) Inventor Kiyo-Sugawara Oita 54 (56) References, 1044, Enashida, Usuki-shi, Ueno Pref. JP-A-2-184519 (JP, A) JP-A-3-285816 (JP, A) JP-A-4-97910 (JP, A) JP-A- 1-301511 (JP, A) Special Table 5-509282 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) C01F 11/18

Claims (2)

(57) [Claims] 1. A method for producing calcium carbonate by a carbonation reaction of calcium hydroxide with carbon dioxide, comprising: reacting under a reaction condition of forming basic calcium carbonate in a process of forming calcium carbonate and having the following structural formula (1):
The carbonation reaction is carried out in the presence of a primary amine, a secondary amine, a tertiary amine, a quaternary amine compound represented by (2) or (3), or an organic amine compound which is a polymer thereof. A method for producing plate-shaped calcium carbonate, which comprises carrying out the method. [Structural formula 1] (In the formula, R ₁ is an alkyl group, an olefin group, a diolefin group or an aromatic group. R ₂ and R ₃ are a hydrogen atom or an alkyl group and may be different from each other.) ] (In the formula, R ₁ , R ₂ R ₄ and R ₅ are a hydrogen atom or an alkyl group and may be different from each other. R ₃ is an alkyl group, an olefin group, a diolefin group or an aromatic group. ) [Structural Formula 3] (In the formula, R ₁ , R ₂ R ₄ , R ₅ , R ₇ and R ₈ are hydrogen atoms or alkyl groups and may be different from each other.
₃ and R ₆ are alkyl groups, olefin groups, diolefin groups or aromatic groups. n is an integer of 1 or more. ) 2. A carbonation rate of 60% in the carbonation process.
2. The method for producing plate-like calcium carbonate according to claim 1, wherein the electric conductivity is reduced to 3.5 mS / cm or less before the reaction before the temperature exceeds the above.