KR100231114B1 - Method for preparing calcium carbonate used for filled paper - Google Patents

Abstract

The present invention relates to a method for producing a calcium carbonate for internal battery having a total diameter of 0.2-0.3 μm in diameter and 1.0 ± 0.2 μm in long diameter and fusiform.

Carbon dioxide gas was introduced into the sand milled lime oil to prepare a suspension suspension of 0.04 μm of colloidal calcium carbonate, and another sand milled lime oil obtained by previously adding ₂ mol of NH ₄ Cl to 0.01-0.20 mol / Ca (OH) was added. By adding 10-30 mol / CaCO ₃ mol to the suspension and introducing carbon dioxide gas, the above-mentioned calcium carbonate battery may be prepared.

Description

Method for producing calcium carbonate for battery

Representative examples of the synthetic calcium carbonate produced by the reaction of lime oil and carbon dioxide gas are cuboid colloidal calcium carbonate and short diameter of 0.01 to 0.10 μm in total diameter (mean particle diameter measured by electron microscope). There are fusiform hard calcium carbonates having a diameter of ˜0.5 μm and a diameter of 1 to 20 μm, and are used in rubber, plastic, paint, ink, sealant and paper industry, respectively. In the paper industry, as a filler for internal batteries, hard calcium carbonate, mainly composed of fusiform calcium carbonate having a short diameter of 0.2 to 0.3 µm and a long diameter of 1 to 4 µm, is mainly used as a filler for internal batteries. .

In addition, fillers at the time of papermaking with acid size by bronze wire were generally talc, but after changing to neutral size papermaking method by plastic wire, wire wear and whiteness are excellent and relatively cheap calcium carbonate This has been conceived.

Gel calcium carbonate in calcium carbonate has excessively fine particles, poor retention, poor opacity of papermaking, and heavy calcium carbonate, which is simply pulverized limestone, has good wear of plastic wire. Therefore, fusiform hard calcium carbonate is mainly used as an optimal filler.

However, the conventional hard calcium carbonate cannot satisfy the material retention rate, wire wear degree, and whiteness and opacity of the paper sheet due to the non-uniform particle size distribution. Thus, fusiform calcium carbonate with uniform particle size is strongly desired from the industry. It is becoming.

Although fusiform calcium carbonate for internal battery is called hard calcium carbonate, the manufacturing method belongs to the synthetic calcium carbonate produced by the reaction of lime oil and carbon dioxide with respect to the heavy calcium carbonate obtained by pulverizing limestone. With respect to the fine calcium carbonate mainly composed of particles having a short diameter of 0.2 to 0.5 µm and a long diameter of 1 to 20 µm, the bulky particles are called hard calcium carbonate.

If we divide these manufacturing conditions,

1) Calcium carbonate is introduced into the lime oil at a relatively low concentration and low temperature of 3 to 10%, 10 to 20 ° C by 20 to 40% by volume of carbon dioxide gas at 40 to 100 l / min · kg Ca (OH) ₂ relatively rapidly. Immediately after the introduction of carbon dioxide, 0.04 μm of cubic particles are produced in large quantities (or many), and the cubic particles combine Ca (OH) _{2 in the system} to form high-basic calcium carbonate and settle. After the growth in the (iii) phase, a very high viscosity gol-gel state is obtained, and further carbonization is continued, thereby Ca (OH) ₂ contained in the bed phase particles is carbonated, The needle-shaped particles are divided into CaCO ₃ to produce cubic particles having a uniform total grain size of 0.04 μm.

Of carbonated before the start in the reaction Ca (OH) sol after ₂ and a _{reaction-second} high basic cost Ca (OH) ₂ is a particle diameter, and constellation are different, before reaction Ca (OH) of the electron through the calcium carbonate when the gel state If remains as it is, finally uniform 0.04 micrometer cubic particle cannot be obtained.

2) In the process of producing hard calcium carbonate, in contrast to colloidal calcium carbonate, a small amount (or minority) of 0.04 탆 particles, which become "species" immediately after introduction of carbon dioxide gas, is produced as small as possible. It is grown sequentially, and is introduced into a relatively high concentration and high temperature lime oil of 10 to 15%, 30 to 50 ° C, and 20 to 40% by volume of carbon dioxide gas is slowly and slowly introduced at 30 to 50 lminkg kg Ca (OH) ₂ . It is to prepare fusiform calcium carbonate having a short diameter of 0.2 to 0.3 mu m and a long diameter of 1 to 4 mu m.

In reality, however, as shown in FIG. 1, in the case of hard calcium carbonate, separate particles grow in terms of long diameter particles of 1 to 4 µm, and they are adsorbed to each other to form large particles of 1 to 20 µm, that is to say strictly fusiform. It is a collection of large and small heterogeneous particles.

Therefore, when this is used as a filler for a battery, low charge retention is obtained, wire wear is high, and the opacity of the battery is bad.

Various attempts have been made to achieve uniformity of the fusiform particles, but whether economic efficiency is important or not, products that meet the desired quality requirements have not been commercialized to date.

1 is a view schematically showing the shapes of the present invention and the conventional product.

The present inventors carefully examined the reaction process by following an electron microscope, and as a result, the hard particles exceeding 1 μm in length were basically 0.04 μm in square crystals. The prokaryotic particles are connected in series, and the chained particles are arranged in parallel with each other with regularity, and are bound at both ends at the end of the reaction to form fusiform particles. It was found that the formation of the abnormal aggregates by growth and adsorption in other directions cannot be avoided unless the above is carried out as a more precise homogeneous system. In order to rectify this drawback, various experiments were repeated and, in particular, if the following three items were strictly followed, industrially uniform fusiform calcium carbonate for battery resistance could be produced relatively simply.

1) Wet grinding of lime oil

After hydration of quicklime, lime oil within at least one month is a large aggregate of 1 μm or more due to the agglomeration of Ca (OH) ₂ particles, and when wet crushed by sand mill or the like, the original total diameter is about 0.1 μm. It was found that it could be dispersed into primary particles of, and it was thought that the use of sand milled lime oil (SM lime oil) would be the first condition to achieve its intended purpose.

2) Species Reaction by Addition of Prokaryotic Particles

In the reaction of lime oil and carbon dioxide gas, 0.04 μm of CaCO ₃ particles, which are nuclei immediately after the reaction, are prepared with as few as possible, and the original Ca (OH) ₂ is slowly carbonated to crystallize C-C. Instead of depositing CaCO ₃ in the axial direction and growing the particles in parallel, instead of adding parallel particles to the co-calculated calcium carbonate-containing suspension, 0.04 μm of prokaryotic particles prepared separately, NH ₄ Cl was added. the separate SM after the addition 10~30mol / CaCO ₃ mol lime milk is adopted a so-called "bell reaction" method for initiating a carbonate reaction.

When the amount of Ca (OH) ₂ in SM lime oil is added to less than 10 mol / CaCO ₃ mol and more than 30 mol / CaCO ₃ mol added to the colloidal calcium carbonate-containing suspension, the particle size distribution is uniform. The desired battery resistance cannot be obtained.

The conditions for producing 0.04 占 퐉 colloidal calcium carbonate, which are the prokaryotic particles, are 40 to 100 l / min-kg Ca in 20 to 40% by volume of carbon dioxide gas in lime oil at 3 to 10% and 10 to 20 ° C as usual except for sand mill treatment. It is good to introduce into (OH) ₂ .

After adding the NH ₄ Cl-containing SM lime oil to the colloidal calcium carbonate-containing suspension, the carbonation conditions are 30 to 50 liters of carbon dioxide gas of 20 to 40% by volume in lime oil at 10 to 15% and 30 to 50 ° C as conventionally. Instead of introducing min.kg Ca (OH) ₂ , SM lime oil at 3 to 10% and 10 to 30 ° C. was added to the colloidal calcium carbonate suspension, followed by 20 to 80 liters of carbon dioxide gas at 20 to 40% by volume. By introducing into min · kg Ca (OH) ₂ , fusiform-resistant calcium carbonate for battery with a short diameter of 0.2 to 0.3 μm and a long diameter of 1 ± 0.2 μm is obtained.

3) addition of NH ₄ Cl

If NH ₄ Cl is added to lime oil in advance, it will not grow in an abnormal direction due to carbonation and can finally obtain fusiform particles having a uniform particle size.

This Cl in NH ₄ Cl ^- as the CaCl ₂ (Cl ion), NH ₄ ⁺ is (NH _{4) 2} serving as CO ₃ in a liquid reactive and generating in order on the surface of the precipitated CaCO ₃ is a prokaryotic particles In this case, it is considered that the phenomenon of promoting growth in the C-axis direction of the CaCO ₃ nucleus occurs when a carbon dioxide gas is introduced after adding SM lime oil containing NH ₄ Cl to the colloidal calcium carbonate-containing suspension. .

Here, after CaCO ₃ precipitates from CaCl ₂ and (NH ₄ ) ₂ CO ₃ , it is reduced to the original NH ₄ Cl, and NH ₄ Cl seems to act effectively to the end catalytically.

However, the addition rate of NH ₄ Cl needs to be 0.01 to 0.20 mol / CaCO ₃ mol, and when it is less than 0.01 mol, it becomes difficult to prevent aggregation of fusiform particles, and when it exceeds 0.20 mol, abnormal growth rapidly increases. Increases.

In the present invention, by satisfying all three items described above, fusiform calcium carbonate can be obtained that has a uniform particle size distribution and excellent in paper stock retention rate, wire wear degree, and whiteness and opacity at the time of papermaking.

In other words, it is difficult to obtain the desired quality when one of the three items is not observed.

Furthermore, the hard calcium carbonate of the present invention can be effectively used for rubber, plastics, paints, inks, and sealants after dry classification in addition to the batteries.

Next, an Example and a comparative example are illustrated.

Example 1

1) Adjust Ca (OH) ₂ , which has been subjected to wet grinding with a sand mill, to 5% and 15 ° C until the particle size of the grind gage is 5 µm 0% (zero). 60 L / min · kg Ca (OH) ₂ was introduced, the carbonation was terminated at pH 6.8, and 0.04 µm cubic calcium carbonate was obtained.

2) The same SM lime oil was adjusted to 8% and 20 ° C, followed by addition of ₂ mol of 0.1 mol / Ca (OH) at 8% and 20 ° C of NH ₄ Cl, and then to the 0.04 μm CaCO ₃ suspension of 1) above. , 15 mol / CaCO ₃ mol was added.

3) A filler for internal batteries was prepared by introducing 30 vol% carbon dioxide gas into 50 L / min · kg Ca (OH) ₂ and dehydrating to 65% solids with a centrifuge at pH 6.8.

In order to clarify the difference with the following Example 1, it summarizes in Table 1, and shows Examples 2-4 and 1-5 for a comparison. The blanks in the table are the same values as in Example 1.

TABLE 1

TABLE 2

Moreover, the image of the particle structure of this invention and a conventional product is shown in FIG.

The present invention is a relatively inexpensive filler for producing high value-added batteries, such as rice paper, general resistant batteries, which have a high material retention rate in papermaking, low wear of plastic wire, and excellent optical properties such as whiteness and opacity. In addition, since the powder has high whiteness, high hiding power, and easy dispersibility, it is also used as a filler for rubber, plastics, paints, inks, sealants and the like, and can greatly contribute to the related industry.

Claims (3)

Incorporating carbon dioxide gas into sand milled lime oil (hereinafter referred to as SM lime oil) to prepare a 0.04 μm suspension of calcium carbonate-containing suspension, in which ₂ mol of NH ₄ Cl was added in an amount of 0.01 to 0.20 mol / Ca (OH). The particle size distribution is uniform, the total diameter is 0.2 ~ 0.3㎛, the total diameter is 1.0 ± 0.2㎛, characterized in that the additional SM lime oil is added to the suspension 10 to 30 mol / CaCO ₃ mol, the step of introducing carbon dioxide gas Method for producing calcium carbonate for phosphorus fusiform-resistant battery. The SM lime oil having a concentration of 3 to 10% by weight and a temperature of 10 to 20 ° C in a step of preparing the 0.04 μm cross-linked calcium carbonate suspension, 40 to 100 l / min. A method for producing a battery for calcium carbonate, characterized in that introduced into kg Ca (OH) ₂ . The method according to claim 1, wherein the concentration and temperature of the NH ₄ Cl-added lime oil are 3 to 10 wt% and 10 to 30 ° C., respectively, and the SM lime oil is added to the colloidal calcium carbonate-containing suspension, followed by introducing the carbon dioxide gas. Is a method for producing a calcium carbonate for battery, characterized in that a carbon dioxide gas is introduced at ₂₀ to 80 l / min · kg Ca (OH) ₂ .

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