JP2012509395A - Zinc flake production equipment - Google Patents

Abstract

The present invention relates to a storage tank for supplying a spherical zinc powder mixed raw material, connecting a ball mill to an inflow line and an outflow line, and flaking the spherical zinc powder while circulating the mixed raw material flowing into the storage tank. This is related to the zinc flake manufacturing equipment, and in particular, it adopts a composite ball mill with an inner tank in which circular discs are stacked in multiple layers, so that the flatness of zinc flakes is good and the porosity is minimized. As a result of improving the anti-corrosion performance by increasing the anti-corrosion performance by increasing the blocking effect of corrosion factors and increasing the specific surface area, the performance of anti-corrosion pigments can be improved and the production time can be shortened by the continuous manufacturing process. And as a result of increasing the yield, commercialization can be achieved.
[Selection] Figure 3

Description

  The present invention relates to a device for producing zinc flakes, and more specifically, by making a spherical zinc powder into flakes using a flake-dedicated composite ball mill, the flatness of the zinc flakes is good and the porosity is minimized, The present invention relates to an apparatus for producing zinc flakes that can increase the performance of anticorrosive pigments and increase the yield and can be commercialized as a result of achieving both an increase in the blocking effect of corrosion factors and an increase in anticorrosion performance by increasing the specific surface area.

  Conventionally, zinc powder functions as a sacrificial positive electrode that is contained in a paint and corrodes before iron, and serves to prevent corrosion of an object to be protected. The zinc powder as an existing anticorrosion pigment is a dull spherical gray powder having a particle size distribution of 1 to 10 μm, and such a conventional spherical zinc powder is greatly formed when employed as an anticorrosion pigment. There was an inconvenience that the anticorrosion performance deteriorated due to the porosity.

  On the other hand, metal flakes are obtained by thinning and flattening spherical metal particles, and this structure provides a high gloss visual effect and an increase in specific surface area. Various methods for flaking by the law have been tried.

  For this reason, in order to eliminate the above-mentioned problems of the zinc powder, various methods for flaking the spherical zinc powder using a mill method have been attempted. As shown in FIG. 1, zirconia, alumina, etc. When a spherical zinc powder is put into the inside of a ball mill having a structure of a cylindrical container 1 filled with a predetermined amount of balls 3 having excellent wear resistance as described above and rotated in the direction of the arrow to form flakes, Although it is easy to control the process, the characteristics of zinc, that is, the combined characteristics of brittleness and ductility, increase the working time, and the disadvantage is that the yield of commercially available zinc flakes in the actual product is extremely low. there were.

  Furthermore, as shown in FIG. 2, spherical zinc powder is put inside an attrition mill having a structure of a cylindrical container 1 filled with a predetermined amount of balls 3 having excellent wear resistance such as zirconia and alumina. In the case where the stirring blade is rotated and the ball is moved in the circumferential direction in the container to give a large impact to the raw material powder and flaked, the manufacturing time is shortened and the energy is larger than the ball mill, Undesirably, there is a problem in the reproducibility of the product, and there is a problem that raw material particles are aggregated in the mill and a loss occurs, resulting in an increase in production cost.

  That is, the above-described method is a method for increasing the grinding efficiency by moving the balls in the spherical zinc powder in the circumferential direction in the rotating body container to give a large impact to the raw material powder, and uses the above-described existing method. There were many problems in flaking zinc.

  Further, PCT Patent Publication No. WO 2004/026508 discloses a method for producing zinc flakes by a dry mill. In this method, since heat is generated in the mill, the consumption of raw materials is increased. There was a disadvantage that the amount was high and the possibility of dust generation was high, making it difficult to apply in practice.

PCT Patent Publication No. WO2004 / 026508 Pamphlet

  The present invention has been made to solve the above-mentioned disadvantages, and its object is to use a novel type of composite ball mill for producing zinc flakes that can improve the production yield and the production amount of zinc flakes, and the spherical zinc powder. The present invention provides a zinc flake manufacturing apparatus capable of shortening manufacturing time and improving production yield by manufacturing zinc flakes by stirring a mixed raw material of a solvent and a lubricant at high speed.

  Another object of the present invention is to produce zinc flakes using spherical zinc powder particles, thereby increasing the specific surface area of the zinc flakes and minimizing the large porosity generated in the case of spherical zinc powder. Therefore, the present invention provides an apparatus for producing zinc flakes that can improve the performance of anticorrosive pigments as a result of achieving both an increase in the effect of blocking corrosion factors and an increase in anticorrosion performance by increasing the specific surface area.

  In order to achieve the above-described object, the present invention provides a zinc flake manufacturing apparatus for manufacturing zinc flakes, wherein the zinc flake manufacturing apparatus 10 includes a storage tank 12, a circulation pump 14, and a composite ball mill 20. The composite ball mill 20 is connected to the storage tank 12, the inflow line 13 and the outflow line 15, and performs the step of flaking the spherical zinc powder while circulating the mixed raw material flowing into the storage tank 12. The ball mill 20 includes an outer tank 30 in which an internal space 31 for containing the mixed raw material supplied from the storage tank 12 is formed, and a rotor 50 disposed in the internal space 31 of the outer tank 30 and driven by an external motor. And the inner space 31 is filled with balls having excellent wear resistance in order to flake spherical zinc powder. Providing an apparatus for manufacturing a zinc flake that.

  According to the apparatus for producing zinc flakes according to the present invention, the flatness of zinc flakes is good, the porosity is minimized, and the corrosion factor is obtained by flaking spherical zinc powder using a flake-dedicated composite ball mill. As a result of improving the anti-corrosion performance by increasing the barrier effect and increasing the specific surface area, the performance of the anti-corrosion pigments can be improved, and the production time and yield can be increased by shortening the production time through the continuous production process. Can be commercialized.

(A) And (b) is a schematic diagram of the conventional ball mill. It is a schematic diagram of the conventional attrition mill. It is a schematic diagram of the manufacturing apparatus of the zinc flakes by preferable embodiment of this invention. It is a schematic sectional drawing for demonstrating in detail the composite ball mill in FIG. It is a perspective view for demonstrating in detail the inner tank in FIG. It is a graph which shows the time-dependent change of the yield of the zinc flake manufactured according to the method of Example 1 and Example 2 which concerns on this invention. It is a graph which shows the time-dependent change of the yield of the zinc flake manufactured according to the method of Comparative Example 1- Comparative Example 3 for the comparison with Example 1 and Example 2. FIG. It is the photograph which image | photographed the zinc flake manufactured according to the method of Example 1 which concerns on this invention with a scanning electron microscope (SEM), and expanded by 2,000 times. It is the photograph which image | photographed the zinc flake manufactured according to the method of Example 2 which concerns on this invention with a scanning electron microscope (SEM), and expanded by 2,000 times.

  Hereinafter, preferred embodiments of a powder production apparatus according to the present invention will be described in detail with reference to the accompanying drawings. It should be noted that in the following description, only portions necessary for understanding the manufacturing method of the present invention will be described, and descriptions of other portions will be omitted in order not to obscure the gist of the present invention. .

  First, based on attached FIG. 3, the zinc flake manufacturing apparatus according to the present invention will be described in detail.

  FIG. 3 is a schematic view of an apparatus for producing zinc flakes according to a preferred embodiment of the present invention, FIG. 4 is a schematic sectional view for explaining the composite ball mill in FIG. 3 in detail, and FIG. It is a perspective view for demonstrating in detail the inner tank in FIG.

  3 and 4, a zinc flake manufacturing apparatus 10 according to a preferred embodiment of the present invention includes a storage tank 12, a circulation pump 14, and a composite ball mill 20, and the composite ball mill 20. Is characterized by performing a step of flaking the spherical zinc powder while circulating the mixed raw material connected to the storage tank 12 and the inflow line 13 and the outflow line 15 and flowing into the storage tank 12.

  At this time, in order to produce zinc flakes, the storage tank 12 is supplied with spherical zinc powder, solvent and lubricant raw materials from the outside, and these raw materials are stirred using a stirrer to produce mixed raw materials. Then, this heterogeneous mixture is supplied to the storage tank 12 through the inflow line 13 by the circulation pump 14. A cooling jacket (not shown) and a stirring device are attached around the storage tank 12 to perform stirring and temperature maintenance.

  Further, as shown in FIG. 4, the composite ball mill 20 includes an outer tank 30 in which an internal space 31 for storing the mixed raw material supplied from the storage tank 12 is formed, and the outer tank 30. A rotor 50 disposed in the internal space 31 and driven by an external motor. The composite ball mill 20 is filled with balls having excellent wear resistance in order to flake spherical zinc powder.

  The outflow line 15 of this kind of zinc flake manufacturing apparatus 10 according to the present invention is provided with a condenser 16 for preventing the temperature of the mixed raw material circulated from the composite ball mill 20 to the storage tank 12.

  Furthermore, the ball filled in the composite ball mill 20 is made of zirconia or alumina material having excellent wear resistance, and the shape thereof is spherical or rod-shaped, and the size of the ball is 0.1 to 5.0 mm. The filling rate of the balls is preferably 20 to 80% by volume with respect to the volume of the inner space to be filled (the inner space formed by the inner diameter of the inner tank, see FIG. 4).

  If the filling rate of the balls is less than 20% by volume, flaking may not proceed even if the filling amount of the balls is small, and if it exceeds 80% by volume, the operation may be stopped due to clogging.

  The apparatus 10 for producing zinc flakes according to the present invention performs the flaking process of spherical zinc powder by using a specially designed composite ball mill 20, so that zinc flakes can be formed like a normal ball mill. Can increase the rotational speed like an attrition mill, the flatness of zinc flakes is good, the porosity is minimized, the blocking effect of corrosion factors is increased and the specific surface area As a result of achieving both expansion of the anticorrosion performance by increasing the anti-corrosion property, the performance of the anticorrosion pigment can be improved, and the yield can be increased and commercialization can be achieved.

  4 and 5, the composite ball mill 20 in the zinc flake manufacturing apparatus 10 according to a preferred embodiment of the present invention includes an inlet 32 connected to the inflow line 13 (see FIG. 3), and the discharge line 15 (see FIG. 3) and an outlet 34 connected to the outer tub 30. The outer tub 30 is provided around the rotor 50 and disposed in the inner space 31 of the outer tub 30 so that the filled balls are accommodated therein. It has the inner tank 40, It is characterized by the above-mentioned. At this time, the inner tank 40 includes a large number of circular disks 41 having an outer diameter smaller than the inner diameter of the outer tank 30 and an inner diameter larger than the outer diameter of the rotor 50 disposed in the inner space 31. Further, the circular disk 41 has a multi-layered structure in which it is stacked in multiple layers by being supported by a support rod 60 that is disposed in parallel to the inflow line 13 at a predetermined interval and is installed in the outer tub 30. In addition, spacers 62 are interposed between the circular disks 41 in the circumferential direction, and the mixed raw material that flows into the inner tank 40 and undergoes the flaking process is discharged to the outflow line 15.

  In the present invention, the circular disc 41 has a multi-layer structure in which 10 to 100 circular discs are stacked in multiple layers, and the number of the circular discs is not limited to the above-mentioned number. The number of sheets can be appropriately adjusted according to the size.

  The inner tub 40 composed of such a circular disk 41 having a multilayer structure increases the frictional force between the mixed raw material, balls (not shown) and the rotor 50, and zinc does not adhere to the inner wall of the outer tub 30 due to condensation. Zinc can be smoothly circulated to the outside. That is, the rotation of the rotor 50 causes friction between the mixed raw material and the balls, resulting in flaking. At this time, before the generation of frictional heat and the aggregation of particles, the gap (circular disc) The material being flaked out through the gaps between the spacers 62 sandwiched between 41. This process is repeated several times, and flaking progresses. When the particle size distribution is measured and the target particle size is reached, the process is stopped and the flaked zinc is recovered.

  At this time, the outer tank 30 is horizontal with respect to the rotation axis of the rotor 50, suppresses vibration generated by the rotation of the rotor 50 connected to the rotation axis as much as possible, and the internal pressure of the outer tank 30 and the mixed raw material flow in. By maintaining the external pressure at the inlet 32 constant, the outer tub 30 and the rotating shaft are prevented from being damaged. In the inner space 31 of the outer tank 30, the inner tank 40 as described above is provided, and the zinc flakes are discharged to the outlet 34. Further, when the mixed raw material flowing out to the outlet 34 through the inner tank 40 (mixed raw material in which the zinc flaking process has progressed) is conveyed to the storage tank 12 through the outflow line 15, It is cooled by a condenser 16 attached to. Such a circulation process stops when the particle size distribution of the mixed raw material falls within the range of 10 to 50 μm. The time until complete flattening depends on the amount of raw material and the rotational speed.

  Hereinafter, a method of flaking spherical zinc powder using a flake-dedicated composite ball mill, which is a zinc flake manufacturing apparatus according to the present invention, will be described.

  The present invention uses a composite ball mill exclusively for flakes, which is an apparatus for producing zinc, and uses 30 to 90% by weight of a solvent, 10 to 70% by weight of spherical zinc powder, and 100 parts by weight of the spherical zinc powder. After the mixed raw material obtained by mixing 0.01 to 10.0 parts by weight in the storage tank 12 is flowed into the composite ball mill 20 container through the inflow line 13, the rotor 50 is moved at a speed of 100 to 8,000 rpm. To produce zinc flakes having a particle size distribution of 10 to 50 μm by rotating for 10 to 360 minutes.

  In addition, in order to improve the workability of flaking, the mixed raw material flows into the composite ball mill 20 and then the storage tank 12 through the outflow line 15 so that the circulation rate of the mixed raw material becomes 5 to 30% by volume. The flaking process is performed while being circulated. When the circulation rate of the mixed raw material is out of the range of the circulation rate, the flaking workability may be lowered.

  In the present invention, the mixed raw material comprises 30 to 90% by weight of a solvent, 10 to 70% by weight of spherical zinc powder, and 0.01 to 10.0 parts by weight of a lubricant with respect to 100 parts by weight of the spherical zinc powder. And preferably.

  In the present invention, the solvent gives fluidity to the spherical zinc powder during the flaking operation, smoothly supplies the mixed raw material from the inflow line to the inside of the composite ball mill, and flakes the spherical zinc powder inside the composite ball mill. When working, it is intended to achieve fluidity and easy volatility of the solvent. If the amount of solvent mixed is less than 30% by weight, the mixture of zinc powder that is relatively spherical compared to the amount of solvent mixed As the amount increases, the fluidity of the spherical zinc powder decreases, and as a result, the flaking workability may decrease. When the amount of the solvent exceeds 90% by weight, the solvent is excessively mixed. As a result, the working time for volatilizing an excessive amount of the solvent is prolonged, so that the flaking workability may be lowered.

  In the present invention, the solvent comprises alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol, aromatic hydrocarbons such as xylene, benzene, toluene, and cocosol, and ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. It is preferable to use one or more selected from the group.

  In the present invention, the spherical zinc powder preferably has a particle size range of 1 to 50 μm, more preferably 1 to 10 μm. When the particle size range of the spherical zinc powder is out of the above-described range, the particle size of the spherical zinc powder may be too small or too large to reduce the flaking workability.

  Further, in the present invention, the lubricant is for preventing the agglomeration of the zinc powder during the mill operation, and the amount of the lubricant mixed is less than 0.01 part by weight with respect to 100 parts by weight of the spherical zinc powder. If the amount of lubricant exceeds 10.0 parts by weight, the purity of the final product may be reduced and the working time may be extended.

  In the present invention, the lubricant includes stearates or volatile oils (white spirit, petroleum spirit, etc.), polyethylene waxes (PCE (perchloroethylene)), fluorine waxes (PTFE (polytetrafluoroethylene)). It is preferable to use one or more silicon waxes.

  Further, the mixed raw material is charged in an amount of 10 to 60% by volume with respect to the volume of the internal space formed by the inner diameter of the inner tank 40 of the composite ball mill (the inner space formed by the inner diameter of the inner tank, see FIG. 4). It is preferable. If the input amount of the mixture is less than 10% by volume, the flaking workability may be reduced by reducing the mill area, and if it exceeds 60% by volume, the zinc powder may be aggregated due to generation of frictional heat.

  Furthermore, as described above, the composite ball mill has a size of 0.1 to 5.0 mm of zirconium or alumina ceramic balls with respect to the volume of the internal space formed by the inner diameter of the inner tank 40 of the composite ball mill. It is preferable to fill -80 volume%.

  Zinc flakes produced according to the method according to the present invention have a commercially available diameter of 10 to 50 μm and a thickness of 0.1 to 2 μm, with a particle diameter and thickness ratio of 10: 1 to 1. Zinc flakes having a ratio of 100: 1, more preferably 15: 1 to 30: 1, are characterized in that the yield can be increased to 60-95%.

  The examples and comparative examples described in more detail below will provide a better understanding of the present invention, but the scope of the present invention is not limited to these examples.

  In the composite ball mill container, 60% by weight of ethyl alcohol, 40% by weight of spherical zinc powder having a particle size range of 4 to 6 μm, and spherical A mixed raw material obtained by adding and mixing 2 parts by weight of a stearic acid lubricant as an additive to 100 parts by weight of zinc powder of the inner space of the composite ball mill (preferable implementation of the present invention) In the example, the internal space formed by the inner diameter of the inner tank, see FIG. At this time, zirconium balls having a size of 0.5 to 0.8 mm are formed by the inner diameter of the inner space of the container (in the preferred embodiment of the present invention, see FIG. 4). As a result of operating at a rotational speed of 1300 rpm under conditions filled to 70% by volume of the inner space), zinc flakes having a diameter of 10 to 50 μm and a thickness of 0.1 to 2 μm were obtained within 30 minutes. % Can be obtained (see C-1 in FIG. 6).

  Using a composite ball mill exclusively for flakes, which is a zinc flake manufacturing apparatus according to the present invention, 70% by weight of ethyl alcohol, 30% by weight of spherical zinc powder having a particle size range of 4 to 6 μm, and spherical A mixed raw material obtained by adding and mixing 2 parts by weight of a stearic acid lubricant as an additive to 100 parts by weight of zinc powder of the inner space of the composite ball mill (preferable implementation of the present invention) In the example, the internal space formed by the inner diameter of the inner tank, see FIG. At this time, zirconium balls having a size of 0.8 to 1.0 mm are formed based on the inner diameter of the inner space of the container (in the preferred embodiment of the present invention, see FIG. 4). As a result of operating at a rotational speed of 1500 rpm under the condition of filling up to 70% by volume of the internal space), zinc flakes having a diameter of 10 to 50 μm and a thickness of 0.1 to 2 μm are within 70 minutes. % Was obtained with a yield of at least% (see C-7 in FIG. 6).

(Comparative Example 1)
Using an attrition mill, spherical zinc powder having a particle size range of 4 to 6 μm is introduced into the internal space of the composite ball mill container so that the filling rate is 30% by volume, and then the size is 1.0 to 1.. As a result of operating at a rotational speed of 2000 rpm in a dry process condition in which a 5 mm zirconium ball was filled in the inner space of the container so that the filling rate was 50% by volume, a diameter of 10 to 50 μm and 0.1 to 2 μm were obtained. Zinc flakes having a particle diameter and thickness ratio of 10: 1 to 50: 1 are 21% after 30 minutes, 22% after 60 minutes, and 33% after 120 minutes. It was confirmed that the yield can be obtained. However, after 120 minutes, particle aggregation occurred and the particle size increased significantly, and no further improvement in yield was observed (see A-1 in FIG. 7).

(Comparative Example 2)
After using an attrition mill, 60% by weight of ethyl alcohol and 40% by weight of spherical zinc powder having a particle size range of 4 to 6 μm are charged into the interior space of the composite ball mill container so that the filling rate is 30% by volume. As a result of operating at a rotational speed of 2000 rpm under a wet process condition in which a ball made of zirconium having a size of 1.0 to 1.5 mm was filled in the internal space of the container so that the filling rate was 50% by volume, Zinc flakes having a diameter of 50 μm and a thickness of 0.1 to 2 μm and a particle diameter and thickness ratio of 10: 1 to 50: 1 are 18% after 30 minutes and 21 after 60 minutes. %, After 120 minutes, it was confirmed that a yield of 20% was obtained. However, no further improvement in yield was observed after 48 hours (see A-2 in FIG. 7).

(Comparative Example 3)
A zinc flake was produced by adding 2 parts by weight of a stearic acid lubricant as an additive to 100 parts by weight of zinc powder under the same conditions as in Comparative Example 2. As a result, a diameter of 10 to 50 μm and 0.1 wt. Zinc flakes having a thickness of ˜2 μm and a particle diameter and thickness ratio of 10: 1 to 50: 1 are 26% after 30 minutes, 30% after 60 minutes and 27 after 120 minutes. % Yield was confirmed. However, the yield dropped to 25% or less after 48 hours (see A-3 in FIG. 7).

  When comparing the yield of zinc flakes manufactured according to Example 1 and Example 2 and Comparative Examples 1 to 3, zinc flakes were prepared using a flake-dedicated composite ball mill which is a zinc flake manufacturing apparatus according to the present invention. In the case of manufactured Example 1 and Example 2, when operating at 1300-1500 rpm, it turned out that the yield of 70% or more is shown within 30 minutes. On the other hand, in the case of Comparative Example 1 (dry process), Comparative Example 2 (wet process), and Comparative Example 3 (wet process + additive 2%) in which zinc flakes were produced using an attrition mill, 30 minutes each. It was found that the yield did not exceed 30% even after 60 minutes and 120 minutes.

  In particular, in the case of Comparative Example 1, the amount of the initial by-product is high, and when the milling is performed for 120 minutes or more, the raw materials agglomerate, which is undesirable from the aspect of zinc flake productivity. I understood that.

  Therefore, Example 1 and Example 2 according to the present invention have a good flatness of zinc flakes manufactured according to these methods and a high yield, so that they are commercially competitive mass production processes. I was able to confirm that there was.

  In the present invention, FIG. 6 is a graph showing the change over time in the yield of zinc flakes manufactured according to the methods of Examples 1 and 2 according to the present invention, and FIG. 6 is a graph showing the change over time in the yield of zinc flakes manufactured according to the methods of Comparative Examples 1 to 3 for comparison.

  Further, FIG. 8 is a photograph of the zinc flakes manufactured according to the method of Example 1 according to the present invention, taken with a scanning electron microscope (SEM) and magnified to 2,000 times, and FIG. It is the photograph which image | photographed the zinc flake manufactured according to the method of Example 2 which concerns on an invention with the scanning electron microscope (SEM), and expanded by 2,000 times.

  The present invention has been described above with reference to specific items such as specific components and limited embodiments and drawings, which are provided to assist in a more general understanding of the present invention. However, the present invention is not limited to these embodiments, and various modifications and variations can be made from such description by those skilled in the art to which the present invention belongs. Can be achieved.

Claims (3)

In zinc flake manufacturing equipment,
The zinc flake manufacturing apparatus (10) includes a storage tank (12), a circulation pump (14), and a composite ball mill (20).
The composite ball mill (20) is connected to the storage tank (12), the inflow line (13), and the outflow line (15), and circulates the mixed raw material flowing into the storage tank (12) while circulating the spherical zinc powder. The process of flaking is performed,
The composite ball mill (20)
An outer tank (30) in which an internal space (31) for containing the mixed raw material supplied from the storage tank (12) is formed;
A rotor (50) disposed in the internal space (31) of the outer tub (30) and driven by an external motor;
Have
An apparatus for producing zinc flakes, characterized in that the interior space (31) is filled with balls having excellent wear resistance in order to flake spherical zinc powder. The composite ball mill (20) further includes an inner tank (40) in which filled balls are stored.
The inner tank (40) has an outer diameter smaller than the inner diameter of the outer tank (30) and an inner diameter larger than the outer diameter of the rotor (50) disposed in the inner space (31). The circular disc (41) is formed to have a plurality of circular discs (41), and the circular disc (41) is arranged in parallel with the inflow line (13) at a predetermined interval in the outer tub (30). By being supported by the support rod (60) to be installed, it has a multi-layered multi-layer structure, and spacers (62) are interposed between the circular disks (41) in the circumferential direction, 2. The apparatus for producing zinc flakes according to claim 1, wherein a mixed raw material that flows into the inner tank (40) and is subjected to a flaking process is discharged to the outflow line (15). 3. The said outflow line (15) is further equipped with the capacitor | condenser (16) which prevents temperature rising of the mixed raw material circulated from the said composite ball mill (20) to the said storage tank (12), The Claim 2 characterized by the above-mentioned. Zinc flake production equipment.

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