KR102553132B1 - Pearlescent pigment particle, Apparatus and method for manufacturing thereof - Google Patents

Abstract

The present invention provides pearlescent pigment particles capable of easily forming a rutile crystal structure and easily adjusting the thickness of the coating layer while forming different metal oxide layers on the coating portion coated on the substrate, and an apparatus for manufacturing the same, and It's about manufacturing methods.
An apparatus for producing pearlescent pigment particles according to an embodiment of the present invention is a pearlescent pigment particle in which at least one layer of a coating portion formed of a plurality of layers on the surface of a substrate is adjusted in thickness through a titration method. As a manufacturing apparatus, a plurality of tanks each containing raw materials for coating a substrate, a reactor in which coating is performed by inputting the substrate and raw materials, and each formed between the reactor and each tank to selectively control the supply of the substrate and raw materials and a control unit for controlling each supply control valve. In addition, a method for producing pearlescent pigment particles according to an embodiment of the present invention is a method for producing pearlescent pigment particles in which a coating portion formed of a plurality of layers is formed on the surface of a substrate, the first step of preparing a substrate; ; A second step of preparing a precursor for forming a coating portion; A third step of forming a coating portion on the surface of the substrate, wherein at least one of the plurality of layers forming the coating portion forms a layer made of a metal oxide while adjusting the thickness using a titration method .

Description

Pearlescent pigment particle, apparatus and method for manufacturing the same {Pearlescent pigment particle, Apparatus and method for manufacturing thereof}

The present invention relates to pearlescent pigment particles and a manufacturing apparatus and manufacturing method thereof, and more particularly, a rutile crystal structure can be easily formed while forming different metal oxide layers on a coating part coated on a substrate, , Pearlescent pigment particles capable of easily adjusting the thickness of a coating layer, and a manufacturing device and manufacturing method thereof.

Pearlescent pigments refer to pigments that express pearlescent, iridescent, and metallic hues.

Conventional pearlescent pigments have a structure in which nano-sized metal oxide fine particles are densely coated on mica in the form of micro-sized flakes. At this time, the particle size of the mica particles used is adjusted according to the type of pearl luster pigment and should be maintained in the range of 0.1 to 200 μm. This is because if the mica particles are too small, a lot of light scattering occurs, resulting in a loss of gloss, and if the particles are too large, there are restrictions on use. Therefore, commonly used pearl luster pigments form mica to a thickness of 0.1 to 10 μm and a coating layer formed of metal oxide fine particles to have a thickness of 10 to 150 nm.

On the other hand, metal oxides used in pearlescent pigments include Ti0 ₂ , Si0 ₂ , ZnO, W0 ₃ and the like. Also, CdS and ZnS may be used instead of the metal oxide. The refractive index of Ti0 ₂ is 2.84, the refractive index of Si0 ₂ is 1.457, the refractive index of ZnO is 2.0, the refractive index of W0 ₃ is 1.67, the refractive index of CdS is 2.384, and the refractive index of ZnS is 2.355. am. Therefore, a pearlescent pigment having a predetermined refractive index is produced by coating the material on the surface of mica, which is a base material, using a material exhibiting a desired refractive index.

A typical metal oxide used in pearlescent pigments is TiO ₂ , and the crystal structure of TiO ₂ can be divided into rutile, anatase, and brookite. Among them, Brookite is not used industrially because it is very unstable and difficult to synthesize pure crystals, and TiO ₂ having a rutile and anatase crystal structure is used industrially.

In the case of anatase crystal structure, it is mainly used as a photocatalyst due to its excellent photoactivity, and recently it is widely used for air cleaning. On the other hand, the rutile crystal structure is generally used as a white pigment because of its excellent light resistance and heat resistance. On the other hand, the crystal structure of anatase (Anatase) has a characteristic that a phase transition occurs when heat is received in the process of coating Ti0 ₂ and the crystal structure is changed to rutile (Rutile). In terms of the physical properties of the pigment, Ti0 ₂ of the rutile crystal structure has excellent light resistance, heat resistance, and weather resistance compared to the anatase crystal structure, has good color and hiding power, and has a high refractive index, so it is considered as a pearl luster pigment. It is advantageous that Ti0 ₂ of a rutile crystal structure is used.

In addition, TiO ₂ has good optical properties and is known as a material harmless to the human body, as well as having good corrosion resistance and mechanical durability. In addition, since the refractive index has a refractive index of 1.9 to 2.6 depending on the deposition type, a high refractive index can be used when coated on mica. In particular, since Ti0 ₂ of the rutile crystal structure is transparent and birefringent, it is advantageous to form a rutile crystal structure for use as a pearlescent pigment. However, Ti0 ₂ has a disadvantage in that it is coated with an anatase crystal structure when coated on mica under general coating process conditions.

On the other hand, as a method of coating TiO ₂ on a substrate such as mica, a fluidized bed chemical vapor deposition method and a uniform precipitation method are mainly used.

First, the fluidized bed chemical vapor deposition method is a method of coating a gaseous raw material on a substrate (mica) to be coated.

When TiO ₂ is coated on a substrate (mica) using a chemical vapor deposition method, a reaction shown in Chemical Formula 1 below occurs.

TiCl ₄ + 2H ₂ O + Mica (mica) → TiO ₂ -Mica + 4HCl … [Formula 1]

However, in the case of using the fluidized bed chemical vapor deposition method, since the TiO ₂ coated on the substrate is formed in an anatase crystal structure, in order to phase-transform the anatase crystal structure of TiO ₂ into a rutile crystal structure, during the coating process SnO ₂ should be added. However, in order to induce a phase transition of TiO ₂ by adding SnO ₂ , titanium chloride (TiCl ₄ ) must be heated to a high temperature, so there is a limit to the commercial use of the fluidized bed chemical vapor deposition method.

And, the homogeneous precipitation method is a method in which OH- ions are released through a solution reaction such as hydrolysis without adding a precipitating agent to the solution from the outside when the precipitate is formed so that the precipitation is made.

When TiO ₂ is coated on a substrate (mica) using a uniform precipitation method, a reaction shown in Chemical Formula 2 below occurs.

TiOSO ₄ + Mica (mica) + H ₂ O → TiO ₂ -Mica + H ₂ SO ₄ . [Formula 2]

In the case of using the uniform precipitation method, when a titanium salt solution is added and stirred while applying a certain temperature to ultrapure water containing mica, the titanium salt is hydrolyzed to form a precipitate of titanium hydrate, which is coated on the surface of the mica. However, since the homogeneous precipitation method exhibits strong acidity during the reaction process, it is necessary to neutralize the pH for safety. In addition, in the case of using the uniform precipitation method, since Ti0 ₂ to be precipitated has an elliptical irregular shape, scattering of light occurs due to the shape, which causes a decrease in pearl luster effect.

The description of the above background art is only for understanding the background of the present invention, and should not be taken as an admission that it corresponds to the prior art already known to those skilled in the art.

Korean Patent Registration No. 10-1858414 (Announcement date 2013.05.09)

The present invention provides a pearlescent pigment particle capable of easily forming a rutile crystal structure even at a low temperature by utilizing SnO when Ti0 ₂ is coated on a substrate, and a manufacturing device and manufacturing method thereof.

In addition, the present invention provides a pearlescent pigment particle that can easily control the thickness of a coating layer by coating Ti0 ₂ using a titration method without using a fluidized bed chemical vapor deposition method or a uniform precipitation method, and a manufacturing device and manufacturing method thereof provides

A pearlescent pigment particle according to an embodiment of the present invention includes a substrate; It is coated on the surface of the substrate, and includes a coating portion formed by coating at least two different metal oxides step by step.

The coating unit may include a first metal oxide layer coated on the surface of the substrate; a second metal oxide layer coated on the surface of the first metal oxide layer; A protective layer coated on the surface of the second metal oxide layer is included, and the thickness of the second metal oxide layer is controlled by a titration method.

The base material is flake mica (Mica), the coating part, the first metal oxide layer is formed of tin oxide (SnO) having a rutile crystal structure, and the second metal oxide layer is a rutile crystal structure. It is formed of titanium dioxide (TiO ₂ ) of the structure, and the protective layer is characterized in that it is formed of sodium silicate (Na ₂ SiO ₃ ).

The coating portion is formed of titanium dioxide (TiO ₂ ) having a rutile crystal structure on the surface of the protective layer, and a third metal oxide layer formed to a thickness different from that of the second metal oxide layer is further formed. to be characterized

Each of the second metal oxide layer and the third metal oxide layer has a thickness of 10 to 150 nm.

On the other hand, in the apparatus for producing pearlescent pigment particles according to an embodiment of the present invention, at least one layer of a coating portion formed of a plurality of layers on the surface of a substrate is pearlescent by adjusting the thickness through a titration method. An apparatus for producing pigment particles, wherein a plurality of tanks each contain raw materials for coating a substrate, a reactor in which coating is performed by inputting the substrate and raw materials, and formed between the reactor and each tank, respectively to It includes a supply control valve for selectively adjusting the supply of and a control unit for controlling each supply control valve.

The reactor is characterized in that it includes a stirrer for stirring the substrate and raw materials put into the reactor, and a motor for rotating the stirrer.

The tank includes a base material tank for accommodating a base material, a first tank for accommodating a titanium dioxide (Ti0 ₂ ) precursor, a second tank for accommodating a tin oxide (SnO) precursor, and a second tank for accommodating sodium hydroxide (NaOH). It is characterized in that it includes a third tank and a fourth tank accommodating sodium silicate (Na ₂ SiO ₃ ).

The supply control valve includes a substrate supply control valve for controlling the supply of the substrate, a first supply control valve for controlling the supply of the titanium dioxide (Ti0 ₂ ) precursor, and a second supply control valve for controlling the supply of the tin oxide (SnO) precursor. A supply control valve, a third supply control valve for controlling the supply of sodium hydroxide (NaOH), and a fourth supply control valve for controlling the supply of sodium silicate (Na ₂ SiO ₃ ).

In order to check and process the coating process in real time, the reactor further comprises a thermometer for measuring the temperature inside the reactor, a pH meter for measuring the pH inside the reactor, and a heater for heating the inside of the reactor. with features

The control unit includes a motor controller for controlling the number of rotations of the motor during the process according to selective control of the first supply control valve to the fourth supply control valve, and a motor controller according to the selective control of the first supply control valve to the fourth supply control valve. A process time control unit for controlling a process time, a temperature control unit for adjusting the temperature inside the reactor in response to the selective control of the first supply control valve to the fourth supply control valve, the first supply control valve, and the second supply control valve A pH control unit controlling the pH inside the reactor in real time by controlling the third supply control valve in response to the selective control of the valve and the fourth supply control valve, and the first supply in response to the control of the temperature control unit and the pH control unit It is characterized in that it includes a raw material supply rate control unit for controlling the feed rate of the raw material by controlling the control valve to the fourth supply control valve.

On the other hand, a method for producing pearlescent pigment particles according to an embodiment of the present invention is a method for producing pearlescent pigment particles using the above-described apparatus for producing pearlescent pigment particles, comprising: a first step of preparing a substrate; A second step of preparing a precursor for forming a coating portion; A third step of forming a coating portion on the surface of the substrate, wherein at least one of the plurality of layers forming the coating portion forms a layer made of a metal oxide while adjusting the thickness using a titration method .

In the first step, the substrate is prepared as a flake having a thickness of 0.1 to 10 μm using natural mica or synthetic mica, and in the second step, the precursor is tin oxide (tin oxide forming the first metal oxide layer) It is characterized in that it includes a SnO) precursor and a titanium dioxide (TiO ₂ ) precursor forming the second metal oxide layer.

The third step may include a first step of injecting DI water and a substrate into a reactor in which current flows between the agitation bar and the inner wall; A second process of adding HCl and the tin oxide (SnO) precursor to the reactor and stirring them to form a first metal oxide layer formed of tin oxide (SnO) having a rutile crystal structure on the surface of the substrate; HCl and the titanium dioxide (TiO ₂ ) precursor are added to the reactor and stirred to form a second metal oxide layer formed of titanium dioxide (TiO ₂ ) having a rutile crystal structure on the surface of the first metal oxide layer. The third process of doing; a fourth process of dehydrating in the reactor and then washing the substrate on which the first metal oxide layer and the second metal oxide layer are formed using ultrapure water; and a fifth process of recovering pigment particles by drying the substrate on which the first metal oxide layer and the second metal oxide layer are formed.

The third step may further include a sixth step of further forming a protective layer by coating sodium silicate (Na ₂ SiO ₃ ) on the surface of the pigment particle after the fifth step.

a seventh step of injecting DI water and the pigment particles having the protective layer into the reactor through which current flows between the stirring bar and the inner wall after the sixth step; HCl and the titanium dioxide (TiO ₂ ) precursor are added to the reactor and stirred to form a third metal oxide layer formed of titanium dioxide (TiO ₂ ) having a rutile crystal structure on the surface of the protective layer. It is characterized by further comprising a process.

The third process and the eighth process are characterized in that the formation thickness of the second metal oxide layer and the third metal oxide layer is adjusted by adjusting the time of inputting and stirring the titanium dioxide (TiO ₂ ) precursor.

The third process and the eighth process are characterized by stirring for 3 to 12 hours at pH 1.6 and a temperature of 70 to 80 ° C.

The third process and the eighth process are characterized in that the coating speed is maintained at 20 ~ 30 nm / hr.

According to an embodiment of the present invention, when Ti0 ₂ is coated on a substrate, an effect of easily forming Ti0 ₂ having a rutile crystal structure can be expected even at a low temperature by using SnO.

In addition, by coating using a titration method, an effect of easily adjusting the thickness of the coating layer can be expected.

In addition, it is superior in terms of production time and yield to the conventional fluidized bed chemical vapor deposition method or uniform precipitation method, and it is possible to produce pearlescent pigments of high quality with low manufacturing cost.

In addition, according to an embodiment of the present invention, the coating part can be formed with three or more composite layers to form an excellent refractive index, and accordingly, color anisotropy, dichroism, and birefringence in which direct color and indirect color change depending on the angle are improved. can indicate

In addition, since TiO ₂ having a rutile crystal structure can be easily formed, solvent resistance is excellent, and thus, the effect of broadly expanding the use of pearlescent pigments can be expected.

In addition, by coating two or more metal oxides, the light absorption rate is reduced and the reflectance is increased, so that gloss can be expressed more effectively.

In addition, since all processes are performed inside the reactor, rapid processing is possible.

1 is a cross-sectional view showing pearlescent particles according to an embodiment of the present invention,
2 is a cross-sectional view showing pearlescent particles according to another embodiment of the present invention,
3 is a block diagram of an apparatus for producing pearlescent particles according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, only these embodiments will complete the disclosure of the present invention, and will fully cover the scope of the invention to those skilled in the art. It is provided to inform you. Like reference numerals designate like elements in the drawings.

First, the refractive index is first described for easy explanation of the present invention.

The index of refraction refers to the rate at which the speed of light decreases as it travels through different media. Optically, light has a wave-particle duality, being both a particle and a wave. Waves of light have different velocities in different media. That is, the speed is different when light travels in air or vacuum and when light collides with Ti0 ₂ and is divided into reflected light and refracted light. The degree to which light bends when passing through a boundary between different media is called the index of refraction.

On the other hand, when the standard medium is air and the opposite medium is Ti0 ₂ , when the crystal structure of Ti0 ₂ is rutile, the relative refractive index is about 2.84, which is higher than other metal oxides. It is known that the refractive index is higher. This relative refractive index can be explained by Snell's law.

1 is a cross-sectional view showing pearlescent particles according to an embodiment of the present invention.

As shown in FIG. 1 , pearlescent particles according to an embodiment of the present invention include a substrate 100; Doedoe coated on the surface of the base material 100, and includes a coating portion 200 formed by coating at least two different metal oxides step by step.

As the substrate 100, thin mica (Mica) is used. At this time, natural mica or synthetic mica may be used as the mica.

For example, as the substrate 100, flaky mica having a refractive index of about 1.5 and a thickness of 0.1 to 10 μm may be used. At this time, it is preferable to use a white color and an even surface.

The coating unit 200 may be implemented as a plurality of layers by coating different metal oxides in stages to have various refractive indices.

For example, the coating unit 200 may include a first metal oxide layer 210 coated on a surface of a substrate; a second metal oxide layer 220 coated on the surface of the first metal oxide layer 210; A protective layer 230 coated on the surface of the second metal oxide layer 220 is included.

At this time, the first metal oxide layer 210 is formed of tin oxide (SnO) having a rutile crystal structure, and the second metal oxide layer 220 is formed of titanium dioxide (TiO ₂ ) having a rutile crystal structure. And, the protective layer 230 is preferably formed of sodium silicate (Na ₂ SiO ₃ ).

Therefore, since the first metal oxide layer 210 and the second metal oxide layer 220 form different high refractive indexes, the color expression is clear, and the direct color and the indirect color are clear, so that pearl luster pigments having high luminance can be implemented. there is.

Meanwhile, the first metal oxide layer 210 is formed of tin oxide (SnO) having a rutile crystal structure. When forming the second metal oxide layer 220 formed on the titanium dioxide (TiO ₂ ) at a low temperature, it induces a phase transition from an anatase crystal structure to a rutile crystal structure.

Tin oxide (SnO) forming the first metal oxide layer 210 has a characteristic of reducing light absorption, and since light absorption and reflection have a complementary color effect, the first metal oxide layer 210 is tin oxide. By forming (SnO), pearlescent pigments with excellent refractive index can be implemented.

The second metal oxide layer 220 is formed of titanium dioxide (TiO ₂ ) having a rutile crystal structure, and the first metal oxide layer 210 is formed of tin oxide (SnO) having a rutile crystal structure. Therefore, it can be easily implemented by inducing a phase transition of titanium dioxide (TiO ₂ ) of a rutile crystal structure at a low temperature. At this time, the second metal oxide layer 220 may be formed while controlling its thickness using a titration method. At this time, it is preferable that the second metal oxide layer 220 has a thickness of 10 to 150 nm.

Titanium dioxide (Ti0 ₂ ) forming the second metal oxide layer 220 has a very high refractive index, anisotropy and non-toxicity, and has a high hiding power and is insoluble in all solvents. In addition, titanium hydroxide is synthesized by synthesizing titanium with a strong base such as NaOH through a titration method, and titanium hydroxide has an excellent color reaction (or color reaction), so it is advantageous to synthesize pearlescent pigments from matte to glossy, It is possible to implement pearlescent pigments of higher quality than conventional pearlescent pigments with excellent coloring power and coloring power.

The protective layer 230 is preferably formed of sodium silicate (Na ₂ SiO ₃ ), which is an inorganic adhesive.

Sodium silicate (Na ₂ SiO ₃ ) forming the protective layer 230 is an inorganic adhesive having solvent resistance, and can further enhance the solvent resistance of the second metal oxide layer 220 .

Meanwhile, in the present invention, a metal oxide layer may be further formed on the coating portion in order to implement a more diverse refractive index.

2 is a cross-sectional view showing pearlescent particles according to another embodiment of the present invention.

As shown in FIG. 2 , pearlescent particles according to another embodiment of the present invention include a substrate 100 as in the above-described embodiment; Doedoe coated on the surface of the base material 100, and includes a coating portion 200 formed by coating at least two different metal oxides step by step. In addition, the coating unit 200 includes a first metal oxide layer 210 coated on the surface of the substrate 100; a second metal oxide layer 220 coated on the surface of the first metal oxide layer 210; A protective layer 230 coated on the surface of the second metal oxide layer 220 is included. However, in this embodiment, the third metal is formed of titanium dioxide (TiO2) having a rutile crystal structure on the surface of the protective layer 230 and has a thickness different from that of the second metal oxide layer 220. An oxide layer 240 is further formed.

In this case, the third metal oxide layer 240, like the second metal oxide layer 220, is preferably formed of titanium dioxide (Ti0 ₂ ) having a rutile crystal structure.

At this time, the third metal oxide layer 240 can also be formed while controlling its thickness using a titration method similarly to the second metal oxide layer 220 . Therefore, the thickness of the third metal oxide layer 240 is also preferably formed to be 10 to 150 nm.

However, it is preferable that the thickness of the third metal oxide layer is different from that of the second metal oxide layer 220 .

Therefore, it is possible to implement various colors of the pearl luster pigment by setting a difference between the direct color and the indirect color by the second metal oxide layer 220 and the third metal oxide layer 240 exposed to the outermost part.

3 is a block diagram of an apparatus for producing pearlescent particles according to an embodiment of the present invention.

As shown in FIG. 3 , the apparatus for producing pearlescent pigment particles according to an embodiment of the present invention includes a plurality of tanks 300 in which raw materials for coating a substrate are respectively accommodated, and the substrate and raw materials are inputted for coating. The reactor 400 in which the process proceeds, a supply control valve 500 formed between the reactor 400 and each tank 300 to selectively control the supply of the substrate and raw material, and each supply control valve 500 It includes a control unit 600 for controlling.

The reactor 400 includes a stirrer 410 for stirring the substrate and raw materials put into the reactor 400 and a motor 420 for rotating the stirrer 410 . Here, the stirrer 410 may be a stir bar.

The tank 300 includes a substrate tank 310 for accommodating a substrate, a first tank 320 for accommodating a titanium dioxide (TiO ₂ ) precursor, and a second tank 330 for accommodating a tin oxide (SnO) precursor. and a third tank 340 accommodating sodium hydroxide (NaOH) and a fourth tank 350 accommodating sodium silicate (Na ₂ SiO ₃ ).

Here, 15 to 25 liters of HCl, 15 to 25 kg of D.I water, and 0.5 to 2.5 kg of tin oxide are added to the second tank 330 to form a tin oxide (SnO) precursor. Meanwhile, the second tank 330 may be formed of three subdivided tanks, and each subdivided tank may be directly supplied to the reactor 400 through each valve. That is, HCl, D.I Water, and tin oxide (Tin Oxide) may be directly supplied to the reactor 400 to form a tin oxide (SnO) precursor in the reactor 400, and HCl and D.I Water required for other processes may be During the process, it may be directly supplied to the reactor 400.

The supply control valve 500 includes a substrate supply control valve 510 for controlling the supply of the substrate, a first supply control valve 520 for controlling the supply of the titanium dioxide (Ti0 ₂ ) precursor, and tin oxide (SnO) The second supply control valve 530 for controlling the supply of the precursor, the third supply control valve 540 for controlling the supply of sodium hydroxide (NaOH), and the agent for controlling the supply of sodium silicate (Na ₂ SiO ₃ ) 4 supply control valve 550. In this way, the supply control valve 500 may be formed in each supply pipe connected to each tank.

On the other hand, in order to check and process the coating process in real time, the reactor 400 includes a thermometer 430 for measuring the temperature inside the reactor 400, a pH meter 440 for measuring the pH inside the reactor 400, and , A heater 450 for heating the inside of the reactor 400 is further configured.

The control unit 600 includes a motor controller 610 for adjusting the number of rotations of the motor 420 during the process according to the selective control of the first supply control valve 520 to the fourth supply control valve 550, and The process time controller 620 for controlling the process time according to the selective control of the supply control valve 520 to the fourth supply control valve 550, and the first supply control valve 520 to the fourth supply control valve 550 ) Corresponding to the selective control of the temperature controller 630 for controlling the temperature inside the reactor 400, the first supply control valve 520, the second supply control valve 530 and the fourth supply control valve 550 In response to the selective control of ), the third supply control valve 540 is controlled to adjust the pH inside the reactor 400 in real time, the pH control unit 640, the temperature control unit 630, and the pH control unit 640 In response to the control of ), the first supply control valve 520 to the fourth supply control valve 550 are controlled to control the input speed of the raw material.

Here, the motor controller 610 is connected to the motor 420 to control the speed of the motor 420 for each process, and the process time control unit 620 includes the motor controller 610, the temperature control unit 630, the pH It is connected to the control unit 640 and the raw material supply speed control unit 650 respectively to control the process time in real time, and the temperature control unit 630 is connected to the thermometer 430 and the heater 450 to correspond to the temperature sensed value. to control the temperature of the heater for each process, the pH control unit 640 is connected to the pH meter 440 to control the pH for each process, and the raw material supply rate control unit 650 is connected to the supply control valve 500 Controls the real-time supply amount of each supply control valve (510, 520, 530, 540, 550).

On the other hand, after each process is completed, an outlet (not shown) is formed in the reactor 400 to discharge the raw material input into the reactor 400, and the outlet is formed with a discharge pipe (not shown) formed with a discharge valve (not shown) and It is connected.

In the apparatus for producing pearlescent pigment particles configured as described above, the substrate supply control valve 510 is controlled to input the substrate into the reactor 400, and the first supply control valve 520 to the fourth supply control valve 550 are operated. Selectively control to form the coating portion 200 on the substrate.

Here, as an example, a process of forming the coating unit 200 on a substrate using the apparatus for producing pearlescent pigment particles will be described.

First, the control unit 600 controls the substrate supply control valve 510 to input the substrate into the reactor 400, and then controls the second supply control valve 530 to supply the tin oxide (SnO) precursor to the reactor 400. Put in and stir. Accordingly, a first metal oxide layer formed of tin oxide (SnO) having a rutile crystal structure is formed on the surface of the substrate. At this time, 15 ~ 25ℓ of HCl, 15 ~ 25kg of D.I water, and 0.5 ~ 2.5kg of tin oxide (Tin Oxide), a precursor of tin oxide (SnO), were added to the second tank 330, and tin oxide was stirred in advance. It is preferable to feed the (SnO) precursor to the reactor 400. Of course, when the second tank 330 is divided into three, it may be directly supplied to the reactor 400 from each tank.

Subsequently, the control unit 600 controls the first supply control valve 520 to inject and stir the titanium dioxide (Ti0 ₂ ) precursor, thereby forming titanium dioxide (Ti0 ₂ ) having a rutile crystal structure on the surface of the first metal oxide layer. ) to form a second metal oxide layer formed of.

Here, when the first metal oxide layer and the second metal oxide layer are formed, the control unit 600 controls the third supply control valve 540 to inject sodium hydroxide (NaOH) into the reactor 400 so that the reactor 400 ) The internal pH can be adjusted in real time within the range of 1.6 ~ 7.5. In addition, the temperature inside the reactor 400 can be adjusted in real time. In this way, by controlling the pH and temperature inside the reactor 400 in real time by interlocking with the supply speed of the raw material, various pearl luster as well as desired pearl luster can be obtained. In addition, since each supply control valve is controlled by the controller 600, it is easy to apply a titration method and easily adjust the thickness of the second metal oxide layer.

Meanwhile, when the process of forming the second metal oxide layer is completed, the control unit 600 controls the fourth supply control valve 550 to inject sodium silicate (Na ₂ SiO ₃ ) into the reactor 400 so that the second metal oxide layer is formed. A protective layer may be formed on the surface of the oxide layer.

In addition, when the process of forming the protective layer is completed, the control unit 600 controls the first supply control valve 520 to inject and stir the titanium dioxide (TiO ₂ ) precursor to determine rutile on the surface of the protective layer. A third metal oxide layer formed of titanium dioxide (Ti0 ₂ ) of the structure may be formed.

Meanwhile, after each process is completed, a dehydration and washing process may be performed, and ultrapure water may be used for the dehydration and washing process, and may be performed inside the reactor 400 in real time. That is, when each process is completed, the agitator 410 and the heater 450 formed in the reactor 400 are operated to perform dehydration and washing processes inside the reactor 400 . As such, in the present invention, since all processes are processed in the reactor 400, rapid process processing is possible. That is, in the conventional method, manual work of taking out the substrate for the dehydration and washing process performed after each process was required, but by preventing such manual work, process automation and rapid processing are possible.

A method for producing the pearlescent pigment constituted as described above will be described.

A method for producing a pearlescent pigment according to an embodiment of the present invention includes a first step of preparing a substrate; A second step of preparing a precursor for forming a coating portion; A third step of forming a coating portion on the surface of the substrate, wherein at least one of the plurality of layers forming the coating portion forms a layer made of a metal oxide while adjusting the thickness using a titration method .

At this time, in the first step, the substrate is prepared as a thin piece having a thickness of 0.1 to 10 μm using natural mica or synthetic mica.

In the second step, a tin oxide (SnO) precursor forming the first metal oxide layer and a titanium dioxide (TiO ₂ ) precursor forming the second metal oxide layer are separately prepared.

Here, the tin oxide (SnO) precursor uses a tin oxide (Tin Oxide)-based material, and the titanium dioxide (Ti0 ₂ ) precursor uses TiOCl ₂ .

When the substrate, tin oxide (SnO) precursor, and titanium dioxide (Ti0 ₂ ) precursor are prepared in this way, a plurality of layers of coatings are sequentially coated on the substrate.

So, the third step is the first step of injecting ultrapure water (DI Water) and the substrate into the reactor 400 through which current flows between the stirring bar and the inner wall; A second process of adding HCl and the tin oxide (SnO) precursor to the 400 and stirring to form a first metal oxide layer formed of tin oxide (SnO) having a rutile crystal structure on the surface of the substrate class; A second metal oxide formed of titanium dioxide (Ti0 ₂ ) having a rutile crystal structure on the surface of the first metal oxide layer by adding HCl and the titanium dioxide (Ti0 ₂ ) precursor to the reactor 400 and stirring it. a third process of forming a layer; a fourth process of dehydrating in the reactor 400 and then washing the substrate on which the first metal oxide layer and the second metal oxide layer are formed using ultrapure water; and a fifth process of recovering pigment particles by drying the substrate on which the first metal oxide layer and the second metal oxide layer are formed.

Meanwhile, in the third process of forming the second metal oxide layer, the thickness of the second metal oxide layer may be adjusted using a titration method.

In the third process, when TiO ₂ is coated on the surface of the substrate, preferably on the surface of the substrate on which the first metal oxide layer is formed, a reaction shown in Formula 3 occurs using a titration method.

TiOCl ₂ + 2NaOH + Mica (mica) → TiO ₂ -Mica + 2NaCl + H ₂ O … [Formula 3]

The titration method is one of the important operations in quantitative analysis. It is a method of finding out and coating it by dropping it drop by drop. This can be achieved through real-time control of the supply control valve 500 by the control unit 600 . Therefore, it is easy to productively control the thickness of the coating layer by precipitating titanium dioxide (TiO ₂ ) produced by neutralizing titanium chloride (TiOCl ₂ ) with ammonia or sodium hydroxide (2NaOH) and coating it on mica (Mica). .

And, after the fifth process, a sixth process of further forming a protective layer on the surface of the second metal oxide layer by coating sodium silicate (Na ₂ SiO ₃ ) on the surface of the pigment particle is further performed.

On the other hand, after the sixth process to further form the third metal oxide layer on the surface of the protective layer, as in the other embodiments described above, in the reactor 400 through which current flows between the stirring bar and the inner wall, ultrapure water (DI Water) and the above a seventh step of injecting pigment particles having a protective layer formed thereon; HCl and the titanium dioxide (TiO ₂ ) precursor are added to the reactor 400 and stirred to form a third metal oxide layer formed of titanium dioxide (TiO ₂ ) having a rutile crystal structure on the surface of the protective layer. An eighth process of doing may be further performed.

The manufacturing method of the pearlescent pigment as described above will be described through specific examples.

In the present invention, in order to adjust the formation thickness of the second metal oxide layer using a titration method, it is preferable to adjust the time for adding and stirring the titanium dioxide (TiO ₂ ) precursor in the third process described above.

15 ~ 30 ℓ of D.I water and 1.5 ~ 3.5 kg of 0.1 ~ 10㎛ mica (Calcium Aluminum Borosilicate) are added to a 50 ℓ reactor (400) and stirred while maintaining the temperature at 70 ~ 80 ℃. At this time, the stirring bar uses stainless steel made of SU316L, in which Mo is synthesized, and the stirring is started by the motor stirrer.

In addition to the substrate tank 310, four tanks capable of introducing raw materials into the reactor 400 are prepared.

So, in the first tank 320, a titanium dioxide (Ti0 ₂ ) precursor, that is, TiOCl ₂ is prepared, and in the second tank 330, 15 ~ 25ℓ of HCl, 15 ~ 25kg of DI water, and tin oxide (SnO) Prepare by stirring 0.5 ~ 2.5 kg of tin oxide as a precursor.

Then, NaOH is prepared for pH adjustment in the third tank 340, and sodium silicate (Na ₂ SiO ₃ ) aqueous solution for forming a protective layer is prepared in the fourth tank 350.

When the raw materials are prepared in this way, the raw materials prepared in the first tank 320 to the fourth tank 350 are introduced into the reactor 400 according to a predetermined order to perform coating.

At this time, the supply rate of the raw materials introduced into the reactor 400 from the first tank 320 to the fourth tank 350 is maintained at a rate of 5±3 ml/min.

Then, after adjusting the pH of the inside of the reactor 400 to 1.6, the coating is started. Of course, the pH can be adjusted to obtain the desired pearl luster.

First, raw materials are supplied from the second tank 330 and the third tank 340 to the reactor 400, and maintained for 30 minutes while stirring at 35±5 RPM. Then, inside the reactor 400, tin oxide (Tin Oxide), a precursor of tin oxide (SnO), reacts to form a first metal oxide layer on the surface of the substrate.

Then, raw materials are supplied from the first tank 320 and the third tank 340 to the reactor 400, and maintained for 3 to 4 hours while stirring at 45±5 RPM. Then, inside the reactor 400, a second metal oxide layer is formed while being coated on the surface of the first metal oxide layer at a rate of 20 to 30 nm/hr.

Subsequently, the substrate on which the first metal oxide layer and the second metal oxide layer are formed is dehydrated in the reactor 400 and washed four times using DI water. At this time, the agitator 410 and the heater 450 formed in the reactor 400 are operated to perform dehydration and washing processes inside the reactor 400 .

Then, the substrate on which the first metal oxide layer and the second metal oxide layer are formed is put into the reactor 400 again, and maintained for 1 hour while stirring at 45±5 RPM. Then, a protective layer is formed on the surface of the second metal oxide layer.

Subsequently, the substrate on which the protective layer is formed is dehydrated in the reactor 400 and washed 4 times using D.I Water. At this time, the agitator 410 and the heater 450 formed in the reactor 400 are operated to perform dehydration and washing processes inside the reactor 400 .

After washing, dry at 350 ℃ for 24 hours.

Thus, a pearlescent pigment in which titanium dioxide (TiO ₂ ) having a rutile crystal structure having a thickness of 40 to 60 nm forms the second metal layer was recovered. The recovered pearlescent pigment was white with a very high refractive index.

Example 2 supplies raw materials from the first tank 320 and the third tank 340 to the reactor 400, which is the process of forming the second metal oxide layer, and the holding time is 5 during the process of stirring at 45 ± 5 RPM. A pearlescent pigment was prepared under the same conditions as in Example 1, except that the mixture was maintained for about 7 hours.

Thus, a pearlescent pigment in which titanium dioxide (TiO ₂ ) having a rutile crystal structure having a thickness of 60 to 80 nm forms the second metal layer was recovered. The recovered pearlescent pigment was yellow with a very high refractive index.

In Example 3, raw materials are supplied from the first tank 320 and the third tank 340 to the reactor 400, which is the process of forming the second metal oxide layer, and the holding time is 8 during the process of stirring at 45 ± 5 RPM. A pearlescent pigment was prepared under the same conditions as in Example 1, except that the mixture was maintained for about 9 hours.

Thus, a pearlescent pigment in which titanium dioxide (TiO ₂ ) having a rutile crystal structure having a thickness of 80 to 100 nm forms the second metal layer was recovered. The recovered pearlescent pigment was red with a very high refractive index.

Example 4 supplies raw materials from the first tank 320 and the third tank 340 to the reactor 400, which is the process of forming the second metal oxide layer, and the holding time is 10 in the process of stirring at 45 ± 5 RPM. A pearlescent pigment was prepared under the same conditions as in Example 1, except that the mixture was maintained for about 11 hours.

Thus, a pearlescent pigment in which titanium dioxide (TiO ₂ ) having a rutile crystal structure having a thickness of 100 to 140 nm forms the second metal layer was recovered. The recovered pearlescent pigment was blue with a very high refractive index.

In Example 5, raw materials are supplied from the first tank 320 and the third tank 340 to the reactor 400, which is the process of forming the second metal oxide layer, and the holding time is 11 in the process of stirring at 45 ± 5 RPM. A pearlescent pigment was prepared under the same conditions as in Example 1, except that the mixture was maintained for about 12 hours.

Thus, a pearlescent pigment in which titanium dioxide (Ti0 ₂ ) having a rutile crystal structure having a thickness of 140 to 160 nm forms the second metal layer was recovered. The recovered pearlescent pigment was green with a very high refractive index.

[Comparative example]

In the comparative example, raw materials are supplied from the second tank 330 and the third tank 340 to the reactor 400, which is a process of forming the first metal oxide layer, and the process of maintaining for 30 minutes while stirring at 35 ± 5 RPM A pearlescent pigment was prepared under the same conditions as in Example 1 except that it was not carried out.

Thus, a pearlescent pigment in which titanium dioxide (TiO ₂ ) having an anatase crystal structure having a thickness of 40 to 60 nm forms the second metal layer was recovered. The color of the recovered pearlescent pigment was white similar to that of Example 1.

As can be seen in Examples 1 to 5 above, it was confirmed that the thickness of the second metal oxide layer can be adjusted to a desired level by adjusting the coating time of the second metal oxide layer using the titration method. , it was confirmed that the implemented color can be adjusted according to the thickness of the second metal oxide layer.

In addition, as can be seen from the comparison between the Examples and Comparative Examples, when the first metal oxide layer is formed first before forming the second metal oxide layer and SnO is used together in the formation of the second metal oxide layer, 70 to 70 Even at a relatively low temperature of 80 ° C., titanium dioxide (Ti0 ₂ ) undergoes a phase transition from an anatase crystal structure to a rutile crystal structure, thereby forming a second metal oxide layer having a rutile crystal structure. could confirm that

On the other hand, as can be seen in Examples 1 to 5, while the first metal oxide layer and the second metal oxide layer are formed, while supplying NaOH for pH control to the third tank 340, the pH inside the reactor 400 is adjusted. do. The hydrolysis reaction condition for forming the first metal oxide layer or the second metal oxide layer is preferably maintained at a pH of 1.6 to 7.5 at a temperature of 70 to 80 °C.

If the temperature inside the reactor 400 is lower than 70° C., the reaction proceeds slowly, so that the first metal oxide layer and the second metal oxide layer having a desired thickness are not formed. Also, if the temperature inside the reactor 400 is higher than 80° C., a problem in which hydrolysis occurs in a tank containing raw materials rather than in the reactor 400 may occur.

In addition, the pH inside the reactor 400 is preferably maintained at 1.6 to 7.5 during the reaction, starting at 1.6. If the pH inside the reactor 400 is higher than 7.5, a problem may occur in which desired gloss is not realized.

In addition, it is preferable to implement various colors of white, yellow, red, blue and green by forming the coating thickness of the first metal oxide layer or the second metal oxide layer coated on the substrate to be 10 to 150 nm.

Also, the coating speed of the first metal oxide layer or the second metal oxide layer coated on the substrate is preferably maintained at 20 to 30 nm/hr. If the coating speed is slower than the suggested speed, a problem of slow reaction speed may occur, and if the coating speed is faster than the suggested speed, a problem of not properly coating may occur.

Although the present invention has been described with reference to the accompanying drawings and preferred embodiments described above, the present invention is not limited thereto, but is limited by the claims described below. Therefore, those skilled in the art can variously modify and modify the present invention within the scope not departing from the technical spirit of the claims described below.

The technical idea of the present invention was examined through several examples.

It is obvious that a person skilled in the art to which the present invention pertains can variously modify or change the above-described embodiments from the description of the present invention. In addition, even if not explicitly shown or described, a person skilled in the art may make various modifications from the description of the present invention to the technical idea according to the present invention. is obvious, which still belongs to the scope of the present invention. The above embodiments described with reference to the accompanying drawings are described for the purpose of explaining the present invention, and the scope of the present invention is not limited to these embodiments.

100: base material 200: coating part
210: first metal oxide layer 220: second metal oxide layer
230: protective layer 240: third metal oxide layer
300: tank 400: reactor
500: supply control valve 600: control unit

Claims (15)

delete delete delete At least one of the coating parts formed of a plurality of layers on the surface of a substrate is an apparatus for producing pearlescent pigment particles in which the thickness is adjusted through a titration method,
a plurality of tanks in which raw materials for coating the substrate are respectively accommodated;
A reactor in which coating is performed by inputting the substrate and raw materials;
Supply control valves formed between the reactor and each tank to selectively control the supply of the substrate and the raw material;
Includes a control unit for controlling each supply control valve,

The tank includes a base material tank for accommodating a base material, a first tank for accommodating a titanium dioxide (TiO ₂ ) precursor, a second tank for accommodating a tin oxide (SnO) precursor, and a second tank for accommodating sodium hydroxide (NaOH). 3 tanks and a 4th tank containing sodium silicate (Na ₂ SiO ₃ );

The reactor includes a stirrer for stirring the substrate and raw materials put into the reactor, and a motor for rotating the stirrer,

The supply control valve includes a substrate supply control valve for controlling the supply of the substrate, a first supply control valve for controlling the supply of the titanium dioxide (Ti0 ₂ ) precursor, and a second supply control valve for controlling the supply of the tin oxide (SnO) precursor. A supply control valve, a third supply control valve for controlling the supply of sodium hydroxide (NaOH), and a fourth supply control valve for controlling the supply of sodium silicate (Na ₂ SiO ₃ ),

The control unit includes a motor controller for controlling the number of rotations of the motor during the process according to selective control of the first supply control valve to the fourth supply control valve, and a motor controller according to the selective control of the first supply control valve to the fourth supply control valve. A process time control unit for controlling a process time, a temperature control unit for adjusting the temperature inside the reactor in response to the selective control of the first supply control valve to the fourth supply control valve, the first supply control valve, and the second supply control valve A pH control unit controlling the pH inside the reactor in real time by controlling the third supply control valve in response to the selective control of the valve and the fourth supply control valve, and the first supply in response to the control of the temperature control unit and the pH control unit A raw material supply rate control unit for controlling the feed rate of the raw material by controlling the control valve to the fourth supply control valve;

In order to check and process the coating process in real time, a thermometer for measuring the temperature inside the reactor, a pH meter for measuring the pH inside the reactor, and a heater for heating the inside of the reactor are installed in the reactor,

The motor controller is connected to the motor and controls the speed of the motor for each process,
The process time control unit is connected to the motor controller, temperature control unit, pH control unit and raw material supply speed control unit to control the process time in real time,
The temperature control unit is connected to the thermometer and the heater to control the temperature of the heater for each process in response to the temperature sensing value,
The pH control unit is connected to the pH meter to control the pH for each process,
The raw material supply speed control unit is connected to the supply control valve to control the real-time supply amount of each supply control valve,

An outlet is formed in the reactor to discharge the input raw material,
The outlet is connected to a discharge pipe formed with a discharge valve,

When each process is completed, the discharge valve is opened to discharge the raw material input for the process, and then the dehydration and washing process is performed for the product after each process is completed. Apparatus for producing pearlescent pigment particles. delete delete delete delete delete delete delete delete delete delete delete

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