KR101936043B1 - Titanium oxide inorganic pigment particle and manufacturing method of the same - Google Patents

Abstract

The present invention relates to titanium oxide inorganic pigment particles, which includes: a first region exhibiting a yellow color; a second region exhibiting a blue color while surround the first region; and a third exhibiting a yellow color while surround the second region, in which the yellow color exhibited by the first region, the blue color exhibited by the second region, the yellow color exhibited by the third region are combined to exhibit colors of soft yellow, yellow, soft brown, brown, reddish brown or black-brown as a whole, and to a manufacturing method thereof. According to the present invention, even though a heavy metal material is not doped and other materials are not coated, the colors of the soft yellow, yellow, soft brown, brown, reddish brown or black-brown can be exhibited.

Description

Title: TITANIUM OXIDE INORGANIC PIGMENT PARTICLES AND METHOD FOR MANUFACTURING THE SAME

The present invention relates to an inorganic pigment particle and a method for producing the same, and more particularly, to a titanium oxide inorganic pigment particle exhibiting a pale yellow, yellow, light brown, brown, reddish brown or blackish brown color and a method for producing the same.

The cosmetics industry is rapidly changing from simple cosmetics to functional cosmetics, and development of effective ingredients, evaluation of efficacy and safety of active ingredients, and development of a carrier with excellent skin safety and absorbency are expected to become important research and development tasks .

In functional cosmetics, cosmetics emphasizing only a single function of skin whitening, wrinkle improvement, and ultraviolet ray blocking are most used, and in the case of functional cosmetics containing two functionalities, a mixture of whitening and wrinkle improving functions is most widely used.

However, the development of functional cosmetics has become a serious problem for cosmetics due to environmental hormones and genetic modification, and the demand for functional cosmetics centering on natural products is increasing due to the consumer psychology that prefers "naturalness".

In the case of ultraviolet screening agents, the organic blocker is applied to the skin in a molecular state. Therefore, it can spread ultraviolet rays very effectively when it is applied to the skin. However, since it contacts with the skin at the molecular level, it absorbs ultraviolet rays, And it has been reported that the ultraviolet shielding ability is deteriorated by ultraviolet rays. Therefore, studies on inorganic UV-blocking agents have been actively carried out, but they have problems causing bleaching phenomenon, and studies for solving the problems are needed.

Chromium compounds such as chromium oxide and chromium hydroxides are used as inorganic pigment materials for cosmetics such as eyeliner and makeup base. Recently, the problem of stability of water-soluble chromium in cosmetics for make-up has been raised. Trivalent chromium is an essential element in the human body, but hexavalent chromium is known to cause skin irritation and allergies. The recently revised Cosmetic Safety Standard classifies chromium as one of the heavy metals that can not be used as raw materials for cosmetics.

Considering these points, it is required to study a safe substance which can be used as a natural inorganic pigment material for cosmetics.

Korean Patent Publication No. 10-0335292

The present invention provides a titanium oxide inorganic pigment particle which exhibits a color of light yellow, yellow, light brown, brown, reddish-brown or black-brown color even though no heavy metal is not doped and other materials are not coated, .

A second aspect of the present invention is a display device including a first area displaying a yellow color, a second area surrounding the first area and representing a color of the indigo color, and a third area surrounding the second area, Wherein the color of the yellow series represented by the first region, the color of the indigo series represented by the second region, and the color of the yellow series represented by the third region are combined to form a total of pale yellow, yellow, light brown, Or a black-brown color. The present invention also provides titanium oxide inorganic pigment particles.

The first region may be a region in which white titanium dioxide particles are doped with nitrogen by a nitriding reduction reaction to change the white titanium dioxide particles to a yellowish color.

And the second region may be a region formed by changing the surface of the first region exhibiting the yellow-based color to a color of the indigo color by the nitridation-reduction reaction.

And the third region may be a region formed by changing the surface of the second region representing the color of the indigo system to a yellow-based color by an oxidation reaction.

Wherein the first region is made of N-doped TiO ₂ , the second region is made of N-doped TiO _{2 -x} (0 <x <1) as an oxygen defect structure region, The third region may be composed of N-doped TiO ₂ .

The second region may have an oxygen-deficient inclined structure from the surface toward the center.

The first region is made of N-doped TiO ₂ and the second region is made of N-doped TiO _{2 -x} (0 <x <1) and TiO _x N _y having a rock salt structure (0 <x <1, 0 <y <1), and the third region may be composed of N-doped TiO ₂ .

It is preferable that the TiO _x N _y (0 <x <1, 0 <y <1) forming the rock salt structure exists in the second region at a ratio lower than 40%.

The second region may have a thickness of 0.1 to 20 nm and have a transmittance.

The third region may have a thickness of 0.1 to 20 nm and have a transmittance.

The titanium oxide inorganic pigment particles may have a particle diameter of 10 to 300 nm.

The present invention also provides a method for producing titanium dioxide particles, comprising the steps of: (a) preparing white titanium dioxide particles as a starting material; (b) charging the titanium dioxide particles into a reactor; flowing a gas containing nitrogen into the reactor; (C) a step of nitriding-reducing the first particles exhibiting a yellow-based color to form a first color having a yellow-based color on the first particle surface, Forming a second region in which a first region representing a yellow color is formed and a second region surrounding the first region and having a color of an indigo color by forming a second region representing the second color, And causing a particle to undergo oxidation reaction to form a third region exhibiting a yellow-based color on the surface of the particle exhibiting a color of the blue color system, Yellow, green, brown, reddish brown or black-brown based on the color of the yellow-based color, the blue-based color represented by the second region and the yellow-based color represented by the third region By weight based on the total weight of the titanium oxide particles.

The first region may be a region in which white titanium dioxide particles are doped with nitrogen by a nitriding reduction reaction in the step (b) to change the white titanium dioxide particles to a yellowish color.

The second region may be a region formed by changing the surface of the first region exhibiting the yellow-based color to the color of the indigo blue by the nitridation-reduction reaction in the step (c).

The third region may be a region formed by changing the surface of the second region representing the color of the indigo system to a yellow system color by the oxidation reaction in the step (d).

Wherein the first region is made of N-doped TiO ₂ , the second region is made of N-doped TiO _{2 -x} (0 <x <1) as an oxygen defect structure region, The third region may be composed of N-doped TiO ₂ .

The second region may have an oxygen-deficient inclined structure from the surface toward the center.

The first region is made of N-doped TiO ₂ and the second region is made of N-doped TiO _{2 -x} (0 <x <1) and TiO _x N _y having a rock salt structure (0 <x <1, 0 <y <1), and the third region may be composed of N-doped TiO ₂ .

It is preferable that the TiO _x N _y (0 <x <1, 0 <y <1) forming the rock salt structure exists in the second region at a ratio lower than 40%.

The second region may have a thickness of 0.1 to 20 nm and have a transmittance.

The third region may have a thickness of 0.1 to 20 nm and have a transmittance.

The nitridation-reduction reaction in the step (b) is preferably carried out at a temperature of 300 to 500 캜.

The nitridation reduction reaction in the step (c) is preferably performed at a temperature of 510 to 700 캜, which is higher than the nitriding reduction reaction in the step (b).

The oxidation reaction is preferably carried out at a temperature of 100 to 500 캜.

The titanium dioxide particles may be white particles having a particle size of 10 to 300 nm.

The titanium oxide inorganic pigment particles preferably have a particle diameter of 10 to 300 nm.

According to the present invention, the heavy metal material is not doped, and even if no other material is coated, it exhibits a pale yellow, yellow, light brown, brown, reddish brown or blackish brown color.

According to the method for producing titanium oxide inorganic pigment particles of the present invention, titanium dioxide which is a raw material can be used to form a color of light yellow, yellow, light brown, brown, reddish brown or black brown color without doping with a heavy metal such as Mn, Cr, It is possible to prepare titania particles.

Further, according to the titanium oxide inorganic pigment particle production method of the present invention, natural raw materials are used, and the process is simple and high in reproducibility.

FIG. 1 is a view showing a titanium oxide inorganic pigment particle according to a preferred embodiment of the present invention.
FIGS. 2 to 5 are diagrams for explaining a method for producing titanium oxide inorganic pigment particles according to a preferred embodiment of the present invention.
6 is a view for explaining a method according to the first embodiment for producing titanium oxide inorganic pigment particles.
7 is a view for explaining a method according to a second embodiment for producing titanium oxide inorganic pigment particles.
8 is a view for explaining a method according to a third embodiment for producing titanium oxide inorganic pigment particles.
9 is a view for explaining a method according to a fourth embodiment for producing titanium oxide inorganic pigment particles.
10 is a view showing an example in which the colors appearing in combination are changed according to the example of changing the color of the second region according to the nitridation-reduction temperature and the transmittance of the second region.
FIG. 11 is a diagram illustrating an example in which colors appearing in combination of colors are changed according to the example of color change of the third region and the transmittance of the third region according to the oxidation temperature.
12 is a photograph showing the color of particles formed by the nitriding reduction reaction according to Experimental Examples 1 to 6.
13 is a photograph showing the color of titanium oxide inorganic pigment particles formed by oxidation reaction according to Experimental Examples 7 to 24. FIG.
FIG. 14 is a view showing a color evaluation result using a colorimeter of particles produced through a nitriding reduction reaction according to Experimental Examples 1 to 6. FIG.
FIG. 15 is a view showing a result of color evaluation using a colorimeter of titanium oxide inorganic pigment particles formed by an oxidation reaction according to Experimental Examples 7 to 12. FIG.
16 is a view showing a color evaluation result using a colorimeter of titanium oxide inorganic pigment particles formed by oxidation reaction according to Experimental Examples 13 to 18. FIG.
17 is a graph showing the result of color evaluation using a colorimeter of titanium oxide inorganic pigment particles formed by an oxidation reaction according to Experimental Examples 19 to 24. FIG.
18 is a graph showing the change in color with time after dispersing H ₃ PO ₄ etchant in titanium dioxide inorganic pigment particles formed by oxidation reaction according to Experimental Example 10 and particles formed by nitriding reduction reaction according to Experimental Example 4 .

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, it should be understood that the following embodiments are provided so that those skilled in the art will be able to fully understand the present invention, and that various modifications may be made without departing from the scope of the present invention. It is not.

A titanium oxide inorganic pigment particle according to a preferred embodiment of the present invention includes a first region that exhibits a yellow color, a second region that surrounds the first region and exhibits an indigo color, and a second region that surrounds the second region And a third area indicating a yellow system color, wherein the yellow system color represented by the first area, the indigo system color represented by the second area, and the yellow system color represented by the third area are color-combined Generally, the colors are light yellow, yellow, light brown, brown, reddish brown or blackish brown.

The first region may be a region in which white titanium dioxide particles are doped with nitrogen by a nitriding reduction reaction to change the white titanium dioxide particles to a yellowish color.

And the second region may be a region formed by changing the surface of the first region exhibiting the yellow-based color to a color of the indigo color by the nitridation-reduction reaction.

And the third region may be a region formed by changing the surface of the second region representing the color of the indigo system to a yellow-based color by an oxidation reaction.

Wherein the first region is made of N-doped TiO ₂ , the second region is made of N-doped TiO _{2 -x} (0 <x <1) as an oxygen defect structure region, The third region may be composed of N-doped TiO ₂ .

The second region may have an oxygen-deficient inclined structure from the surface toward the center.

The first region is made of N-doped TiO ₂ and the second region is made of N-doped TiO _{2 -x} (0 <x <1) and TiO _x N _y having a rock salt structure (0 <x <1, 0 <y <1), and the third region may be composed of N-doped TiO ₂ .

It is preferable that the TiO _x N _y (0 <x <1, 0 <y <1) forming the rock salt structure exists in the second region at a ratio lower than 40%.

The second region may have a thickness of 0.1 to 20 nm and a region having a transmittance (region having high transmittance).

The third region may have a thickness of 0.1 to 20 nm and may have a region having a transmittance (region having a high transmittance).

The titanium oxide inorganic pigment particles may have a particle diameter of 10 to 300 nm.

A method for producing titanium oxide inorganic pigment particles according to a preferred embodiment of the present invention comprises the steps of: (a) preparing white titanium dioxide particles as a raw material; (b) charging the titanium dioxide particles into a reactor, Forming a first particle exhibiting a yellow-based color by nitridation-reduction reaction while flowing a gas containing nitrogen into the first particle; (c) subjecting the first particles exhibiting the yellow-based color to a nitriding- And a second region showing a color of a blue color is formed on the surface of the first particle representing the color of the first color, (D) a step of oxidizing the second particles to form a third color having a yellow-based color on the surface of the second color, Wherein the color of the yellow series represented by the first region, the color of the indigo series represented by the second region, and the color of the yellow series represented by the third region are combined to form a totally pale yellow, yellow , Light brown, brown, reddish brown or blackish brown.

The first region may be a region in which white titanium dioxide particles are doped with nitrogen by a nitriding reduction reaction in the step (b) to change the white titanium dioxide particles to a yellowish color.

The second region may be a region formed by changing the surface of the first region exhibiting the yellow-based color to the color of the indigo blue by the nitridation-reduction reaction in the step (c).

The third region may be a region formed by changing the surface of the second region representing the color of the indigo system to a yellow system color by the oxidation reaction in the step (d).

Wherein the first region is made of N-doped TiO ₂ , the second region is made of N-doped TiO _{2 -x} (0 <x <1) as an oxygen defect structure region, The third region may be composed of N-doped TiO ₂ .

The second region may have an oxygen-deficient inclined structure from the surface toward the center.

The first region is made of N-doped TiO ₂ and the second region is made of N-doped TiO _{2 -x} (0 <x <1) and TiO _x N _y having a rock salt structure (0 <x <1, 0 <y <1), and the third region may be composed of N-doped TiO ₂ .

It is preferable that the TiO _x N _y (0 <x <1, 0 <y <1) forming the rock salt structure exists in the second region at a ratio lower than 40%.

The second region may have a thickness of 0.1 to 20 nm and a region having a transmittance (region having high transmittance).

The third region may have a thickness of 0.1 to 20 nm and may have a region having a transmittance (region having a high transmittance).

The nitridation-reduction reaction in the step (b) is preferably carried out at a temperature of 300 to 500 캜.

The nitridation reduction reaction in the step (c) is preferably performed at a temperature of 510 to 700 캜, which is higher than the nitriding reduction reaction in the step (b).

The oxidation reaction is preferably carried out at a temperature of 100 to 500 캜.

The titanium dioxide particles may be white particles having a particle size of 10 to 300 nm.

The titanium oxide inorganic pigment particles preferably have a particle diameter of 10 to 300 nm.

Hereinafter, titanium oxide inorganic pigment particles according to a preferred embodiment of the present invention will be described in more detail.

FIG. 1 is a view showing a titanium oxide inorganic pigment particle according to a preferred embodiment of the present invention.

1, a titanium oxide inorganic pigment particle according to a preferred embodiment of the present invention includes a first region 110c representing a yellow-based color, a second region 110c surrounding the first region 110c, A second region 120b and a third region 130 that surrounds the second region 120b and shows a yellowish color. The second region 120b includes a yellow color represented by the first region 110c, 120b, and the yellow color represented by the third region 130 are combined to form a color of pale yellow, yellow, light brown, brown, reddish brown, or blackish brown.

The first region 110c is a region in which white titanium dioxide particles are doped with nitrogen by a nitriding reduction reaction to change the white titanium dioxide particles to a yellowish color. The first region 110c may be composed of N-doped TiO ₂ . At the time of X-ray diffraction (XRD) analysis, the N-doped TiO ₂ appears as an anatase phase, a rutile phase, or a mixture thereof.

The second region 120b is a region formed by changing the surface of the first region 110c that exhibits a yellow-based color to a color of the indigo color by the nitridation-reduction reaction. The second region 120b may have a thickness of 0.1 to 20 nm and may have a region having a transmittance (region having high transmittance). The second region 120b having a blue color may have transparency because the thickness of the second region 120b is very small.

The transmittance of the second region 120b is changed according to the thickness of the second region 120b and the transmittance of the second region 120b is changed according to the thickness of the second region 120b through the combination of the first region 110c and the second region 120b Green, green, blue, or indigo blue color is expressed. Accordingly, a first region 110c representing a yellow-based color, a second region 120b representing a navy blue color having a very thin thickness and permeability, and a third region 130 representing a yellow-based color Yellow, light brown, brown, reddish brown or black-brown color as a whole. When the second region 120b is thicker than 20 nm, the transmittance is low, so that the colors of pale yellow, yellow, light brown, brown, reddish brown or black-brown can not be displayed due to color combination. The yellow-based color expressed in the first region 110c can be transmitted to the outside through the second region 120b and thus the yellow-based color expressed in the first region 110c, A yellowish color, a yellowish brown, a light brownish brown color, a reddish brownish brown color or a blackish brownish color may be expressed as a whole in combination with a color of a blue color expressed in the first region 120b and a color of a yellowish color expressed in the third region 130 .

The second region 120b may be composed of an N-doped TiO _{2 -x} (0 <x <1) region having an oxygen defect structure. The second region 120b may have an oxygen-deficient inclined structure from the surface toward the center. More specifically, the second region 120b has a structure in which the degree of oxygen deficiency is lowered from the surface toward the center, and the degree of oxygen deficiency at the surface is high and the degree of oxygen deficiency decreases toward the center. In the X-ray diffraction (XRD) analysis, the N-doped TiO _{2 -x} (0 <x <1) is anatase, rutile, .

The second region 120b is formed by mixing N-doped TiO _{2 -x} (0 <x <1) and TiO _x N _y (0 <x <1, 0 <y <1) having a rock salt structure . In the case where the N-doped TiO _2-x (0 <x <1) and TiO _x N _y (0 <x <1, 0 <y <1) coexist in the second region 120b, the TiO _x N (less than 40%) (for example, 0.01 to 39.9%, more specifically 0.01 to 32.0%) of _y (0 <x <1, 0 <y <1) When the TiO _x N _y (0 <x <1, 0 <y <1) is present in the second region 120b at a ratio of 40% or more, the entirety of the pale yellow, yellow, light brown, brown, reddish brown, The color may not be expressed. Titanium oxide inorganic pigment particles formed by oxidation reaction at 200 ° C for 1 hour in accordance with Experimental Example 11 were 56.5% anatase phase, 11.5% rutile phase , And 32.0% rock salt structure. The thus formed titanium oxide inorganic pigment particles showed a blackish brown color as a whole. Titanium oxide inorganic pigment particles formed by oxidation reaction at 250 ° C for 1 hour according to Experimental Example 17 in an experimental example to be described later in the following Examples were 75.2% anatase phase, 13.4% rutile phase , And a rock salt structure of 11.4%. The thus formed titanium oxide inorganic pigment particles exhibited a reddish brown color as a whole. Titanium oxide inorganic pigment particles formed by oxidation reaction at 300 DEG C for 1 hour according to Experimental Example 24 in an experimental example to be described later in the following Examples were subjected to nitridation reduction reaction at 750 DEG C for 46.5% anatase phase and 53.5% rock salt structure was observed. However, the titanium oxide inorganic pigment particles formed as a whole showed black color and no pale yellow, yellow, light brown, brown, reddish brown or black brown color appeared.

The third region 130 may be a region formed by changing the surface of the second region 120b of the indigo color to a yellow color by the oxidation reaction. The third region 130 may be composed of N-doped TiO ₂ . At the time of X-ray diffraction (XRD) analysis, the N-doped TiO ₂ appears as an anatase phase, a rutile phase, or a mixture thereof.

The third region 130 may have a thickness of 0.1 to 20 nm and may have a region having a transmittance (region having high transmittance). The third region 130 having a yellowish color is very thin and transparent. A first region 110c representing yellow color, a second region 120b representing a blue color having a very thin thickness and permeability, a third region 120b representing a yellow color having a very thin thickness and permeability ( Yellow, light brown, brown, reddish brown or black-brown color as a whole. When the third region 130 is thicker than 20 nm, the transmittance is low and the pale yellow, yellow, light brown, brown, reddish brown or black-brown color may not be expressed by color combination. The yellow color of the first region 110c and the blue color of the second region 120b are combined to form a green, green, blue or indigo color. The third region 130 Is thin with a thickness of about 0.1 to 20 nm, green, green, blue, or indigo-colored colors appearing as a color combination of the first region 110c and the second region 120b are transmitted and can be externally colored have. Accordingly, the yellow-based color expressed in the first region 110c and the indigo-colored color expressed in the second region 120b are combined to produce a green, green, blue, or indigo-colored color, The green, green, blue or indigo-colored colors appearing by combining the colors expressed in the first region 110c and the second region 120b and the yellow-colored colors expressed in the third region 130 are color-combined, As a whole, colors such as light yellow, yellow, light brown, brown, reddish brown or black-brown can be expressed.

The titanium oxide inorganic pigment particles may have a particle diameter of 10 to 300 nm. The titanium oxide inorganic pigment particles of the present invention exhibit pale yellow, yellow, light brown, brown, reddish brown or blackish brown color even though they are not doped with heavy metal such as Mn, Cr, Fe and the like in addition to nitrogen. In addition, even if other materials such as pigments are not coated on the surface, they exhibit colors of light yellow, yellow, light brown, brown, reddish brown or black brown.

The first region 110c and the second region 120b form a core and the third region 130 forms a core portion of the shell portion 110b. shell. Yellow, light brown, brown, reddish-brown or black-brown color through the combination of the core part and the shell part.

Hereinafter, a method for producing titanium oxide inorganic pigment particles according to a preferred embodiment of the present invention will be described in more detail.

FIGS. 2 to 5 are diagrams for explaining a method for producing titanium oxide inorganic pigment particles according to a preferred embodiment of the present invention. FIG. 6 is a view for explaining a method according to the first embodiment for producing titanium oxide inorganic pigment particles, and FIG. 7 is a view for explaining a method according to the second embodiment for producing titanium oxide inorganic pigment particles. FIG. 8 is a view for explaining a method according to the third embodiment for producing titanium oxide inorganic pigment particles, and FIG. 9 is a view for explaining a method according to the fourth embodiment for producing titanium oxide inorganic pigment particles Fig.

Referring to FIGS. 2 to 9, titanium dioxide particles (powder) are prepared as a raw material for preparing titanium oxide inorganic pigment particles according to a preferred embodiment of the present invention. The titanium dioxide particles ('10' in FIG. 2) as a raw material exhibit white (white). Titanium dioxide (TiO ₂ ) has an energy gap of about 3.0 to 3.2 eV, is chemically and biologically stable, and does not corrode well. Titanium dioxide (TiO ₂₎ is present in at least one form in the anatase phase (anatase phase), daily doubles (rutile phase) and a phase called kite (brookite phase). The titanium dioxide particles used as the raw material may be any of the anatase phase, the rutile phase and the brookite phase. The raw material titanium dioxide particles are preferably particles having an average particle diameter of 10 nm to 300 nm. If the particle size of the raw material titanium dioxide particles is less than 10 nm, the cost is uneconomical due to the high cost. When the particle size exceeds 300 nm, the reaction time for producing the titanium oxide inorganic pigment particles according to the present invention becomes long and uneconomical. When used, it can be difficult to mix with other cosmetic ingredients due to the large particle size, and cosmetic ingredients are thickly applied to the skin, which can increase the amount of the cosmetic ingredient used, which can be uneconomical.

(10 ') of white titanium dioxide as a raw material is charged into a reactor and a nitrogen-containing gas (for example, ammonia (NH ₃ ) gas) is allowed to flow into the reactor, A first particle 110a having a yellowish color is formed as shown in FIG. The reactor may be a rotary kiln or the like capable of uniformly conducting a gas-solid reaction. When a gas containing nitrogen such as ammonia (NH ₃ ) gas is flowed, a reducing atmosphere is formed inside the reactor.

The first temperature T1 for the nitridation reduction reaction is preferably 300 to 500 deg. C, more preferably 400 to 500 deg. If the temperature in the reactor is less than 300 ° C, sufficient nitridation reduction may not occur and the amount of nitrogen doped in the raw material titanium dioxide particles may not be sufficient. Accordingly, nitrogen doped TiO ₂ (N -doped TiO ₂ ) may not be formed. If the temperature in the reactor is higher than 500 ° C, the energy consumption is excessive, which may result in an uneconomical and coloration of the target yellow system. For example, even if nitriding reduction treatment is performed at a temperature higher than 700 ° C. or nitriding reduction reaction is performed at a temperature lower than 700 ° C., the oxygen deficiency amount is increased during the nitriding treatment for a long time, and the oxygen deficiency amount is increased by N-doped TiO _{2 - When x} is greater than 1, the crystal structure is changed to TiO _x N _y (0 <x <1, 0 <y <1), which forms the Roct salt structure, and the proportion of the salt salt structure And a black color when it is more than a predetermined value (for example, 96%). The nitridation reduction reaction is preferably performed for 10 minutes to 24 hours, preferably 30 minutes to 12 hours, more preferably 1 to 10 hours. If the nitridation reaction time is short, a sufficient nitridation reduction reaction may not take place, and the amount of nitrogen doped in the raw material titanium dioxide particles may not be sufficient, so that N-doped TiO ₂ that shows yellowish color is not formed And it is uneconomical in terms of time and cost even if the nitriding reduction reaction time is too long. The rate of temperature rise up to the first temperature T1 is preferably 1 to 50 占 폚 / min, more preferably 2 to 20 占 폚 / min.

As shown in FIGS. 6 and 9, the nitridation reduction reaction may be performed in a period (S1 interval) in which the temperature is maintained constant at the first temperature T1. However, as shown in FIGS. 7 and 8, T1) to a second temperature (T2) at a predetermined temperature rising speed (S2 section). 7 and 8, when the nitridation reduction reaction is performed in a section (section S2) in which the temperature rises from the first temperature T1 to the second temperature T2 as shown in FIGS. 7 and 8, (For example, 0.1 to 10 占 폚 / min), and more preferably about 0.1 to 5 占 폚 / min.

The raw material titanium dioxide particles react with a nitrogen-containing gas such as ammonia (NH ₃ ) gas in the reactor, thereby directly doping the raw material titanium dioxide particles with nitrogen. In the initial stage of the nitridation reduction reaction, the titanium dioxide particles of the starting material are changed from white (white) to yellow N-doped TiO ₂ , and the first particles 110a exhibiting a yellow color series due to the influence of nitrogen .

The first particles 110a exhibiting the yellow color are subjected to a nitridation reduction reaction to form a second region (120a 'in FIG. 4) showing the indigo color on the surface of the first particles showing yellowish color As shown in FIG. 4, a first particle 110b having a yellow color and a second particle 120b having a blue color are formed while surrounding the first particle 110b .

When the first particles 110a exhibiting a yellow-based color are nitrided and reduced at a second temperature T2, a second region 120a having a blue color is formed on the surface as shown in FIG. 4 . A second region ('120a' in FIG. 4) showing a color of the indigo color can be formed on the surface by suitable nitridation and reduction reaction. As shown in FIG. 4, by a nitridation reduction reaction at the second temperature T2, a first region 110b showing a yellow-based color and a second region 110b surrounding the first region 110b, Two regions 120a are formed.

The second region ('120a' in FIG. 4) may be composed of an N-doped TiO _{2 -x} (0 <x <1) region having an oxygen defect structure. The nitrogen-doped particles are continuously exposed to the ammonia gas from the surface of the nitrogen-doped particles by a reducing atmosphere (a reducing atmosphere containing a nitrogen-containing gas) according to the reaction temperature and time, and react with oxygen to form NO _x , defect structure. The second region ('120a' in FIG. 4) having an oxygen defect structure has an oxygen deficiency gradient structure from the surface toward the center. More specifically, the second region ('120a' in FIG. 4) has a structure in which the degree of oxygen deficiency is reduced from the surface toward the central region. The degree of oxygen deficiency at the surface is high and the degree of oxygen deficiency decreases toward the center Respectively. As oxygen defects are generated, the oxidation number of Ti is changed. N-doped TiO _{2 -x} (0 <x <1) is formed through the formation of oxygen defects in yellow N-doped TiO ₂ . In the atmosphere of nitrogen containing nitrogen such as ammonia (NH ₃ ) gas, about several percent of nitrogen is doped in the titanium dioxide particle in the raw material material during the nitriding reduction reaction, ) Of titanium dioxide particles change to yellow color and the nitridation reduction reaction is continued to form an oxygen defect structure from the surface of the N-doped TiO ₂ to become TiO _{2 -x} , N-doped TiO _{2 -x} (0 < x < 1) is formed on the surface due to the change. TiO _{2 -x} and there is a large amount of oxygen-containing air gap a high content of nitrogen (nitrogen) than the nitrogen-doped _{TiO 2 (N-doped TiO 2} ) ( a first area ( '110b' in Fig. 4)). When TiO _{2 -x} has an x value of 1 or more, it changes to TiO _x N _y (0 <x <1, 0 <y <1) which forms a rock salt structure. In the case where the nitridation reduction reaction is performed at a relatively low temperature or is relatively short, a yellow region is present in the first region (110b 'in FIG. 4) and a second region (110b' 4). In the case where the nitriding reduction reaction is relatively long, the second region ('120a' in FIG. 4) as well as the first region (110b in FIG. 4) ') Is also changed to the color of the indigo color, so that the first area (' 110b 'in FIG. 4) may not be able to exhibit the yellow color.

The second region 120b is formed by mixing N-doped TiO _{2 -x} (0 <x <1) and TiO _x N _y (0 <x <1, 0 <y <1) having a rock salt structure . In the case where the N-doped TiO _{2 -x} (0 <x <1) and TiO _x N _y (0 <x <1, 0 <y <1) coexist in the second region (120a ' , A ratio (less than 96%) of the TiO _x N _y (0 <x <1, 0 <y <1) of less than 96% (eg 0.1 to 95.9%, more specifically 1 to 95.1% It is preferable that it exists. In the case where the TiO _x N _y (0 <x <1, 0 <y <1) is present in the second region (120a 'in FIG. 4) The third region (130 'in FIG. 5) may not be formed even though the oxidation reaction is performed on the first region 120a of FIG. 4, The color of the series may not be expressed. In the following Experimental Example, it was confirmed that when nitriding reduction reaction was carried out at 525 ° C and 550 ° C for 10 hours, only anatase phase and rutile phase were present and a rock salt structure was not formed, and nitridation at 600 ° C for 10 hours in the case where the reduction reaction of _{4.9% N-doped TiO 2 -x} (0 <x <1) and rock salt of 95.1% (rock salt) structure _{(TiO x N y (0 <} x <1, 0 <y <1) ), And 100% rock salt structure was formed when the nitridation reduction reaction was performed at 750 ° C. for 10 hours, and N-doped TiO _{2 -x} (0 <x <1) was not present Respectively. In the experimental examples to be described later, titanium dioxide inorganic pigment particles formed by oxidation reaction at 300 ° C for 1 hour had a ratio of rock salt structure of 100% for particles subjected to nitridation reduction at 750 ° C for 10 hours, and 46.5% of anatase And the rock salt structure of 53.5% was observed. However, the titanium oxide inorganic pigment particles formed as a whole showed black color and no pale yellow, yellow, light brown, brown, reddish brown or black brown color appeared .

The thickness of the second region ('120a' in FIG. 4) formed on the surface increases as the nitridation reduction temperature increases, and the transmittance of the second region (120a 'in FIG. 4) decreases accordingly. When the nitriding reduction temperature is higher, the phase of the second region ('120a' in FIG. 4) formed by the oxygen deficiency structure is transformed into a rock salt structure, and the formed ratio of the formed rock salt structure If it exceeds a certain ratio, black color can be expressed.

The nitridation reduction reaction for causing the blue color to be expressed on the surface is preferably performed at a temperature of 510 to 700 ° C, preferably 520 to 650 ° C, more preferably 525 to 600 ° C. When the temperature in the reactor is lower than 510 ° C., a sufficient nitridation reduction reaction may not occur and a second region ('120a' in FIG. 4) showing a dark blue color is formed on the surface, but a yellow N-doped TiO ₂ can be maintained as it is. If the temperature in the reactor is higher than 700 ° C, the energy consumption becomes uneconomic and the content of TiO _x N _y (0 <x <1, 0 <y <1) (eg, 96%) of the rock salt structure is increased to a certain level (eg, 96%), even if oxidized, a black color develops and the pale yellow, yellow, light brown, brown, reddish brown or black brown color may not appear. When the nitriding reduction treatment is performed at a temperature higher than 700 ° C. or when the nitriding reduction reaction is performed at a temperature lower than 700 ° C., the oxygen deficiency amount is increased during the nitriding treatment for a long period of time, and the oxygen deficiency amount is increased from the N-doped TiO _{2 -x} to x TiO _x N _y (0 < x < 1, 0 < y < 1), which is a salt salt structure, is changed. When the structure of the salt salt is more than a certain percentage (for example, 96%), it shows a black color.

On the other hand, in the low-temperature nitriding and reduction reaction, an oxygen deficiency structure does not occur, a yellow N-doped TiO ₂ is formed, and a second region ('120a' in FIG. 4) .

The nitridation-reduction reaction at the second temperature T2 may be performed in-situ by raising the temperature from the first temperature T1 to the second temperature T2 as shown in FIGS. 7 and 8 And may be performed after cooling at a first temperature T1 and then at a second temperature T2 as shown in FIG.

Considering the above points, the nitridation reduction reaction for forming the second region ('120a' in FIG. 4) that exhibits the indigo color is performed at 510 to 700 ° C, preferably 520 to 650 ° C, more preferably 525 Deg.] C to 600 [deg.] C for 1 minute to 24 hours, more preferably 5 minutes to 18 hours, and further preferably 10 minutes to 12 hours.

The transmittance of the second region ('120a' in FIG. 4) varies depending on the thickness of the second region ('120a' in FIG. 4) Green, blue, or indigo color through a combination of a region ('110b' in FIG. 4) and a second region ('120a' in FIG. 4).

The particles thus formed are color-combined in a first region ('110b' in FIG. 4) representing a color of a second color ('120a' in FIG. 4) , Green, blue, or indigo blue.

10 is a view showing an example in which the colors appearing in combination are changed according to the example of changing the color of the second region according to the nitridation-reduction temperature and the transmittance of the second region.

Referring to FIGS. 4 and 10, the color represented by the second region 120a changes according to the nitridation-reducing temperature, and as the nitriding-reducing temperature increases, the color of the second region 120a changes from light to dark do. For example, when the nitriding reduction temperature is 500 ° C, the second region 120a has a light blue color. When the nitriding reduction temperature is 600 ° C, the second region 120a has a dark blue color. When the nitriding reduction temperature is 750 ° C, the second region 120a exhibits a dark blue color close to black or black.

The transmittance of the second region 120a varies depending on the thickness of the second region 120a and the transmittance of the first region 110b and the second region 120a varies depending on the transmittance of the second region 120a The color to be expressed will vary. In FIG. 10, the overlapping portion ('A' in FIG. 10) between the first region 110b and the second region 120a shows a portion where the first region 110b and the second region 120a appear in color combination. As the transmittance of the second region 120a is lowered from 90% to 0%, the color of the first region 110b and the second region 120a is changed from light color to dark color. For example, when the transmittance of the second region 120a is 90%, the hue of the first region 110b and the second region 120a appearing in color combination is light green, and the transmittance of the second region 120a is 0%, the color of the first region 110b and the second region 120a appears to be indigo blue. When the transmittance is 0%, the ratio of the salt structure is, for example, 96% or more, .

The first region 110b indicating the yellow color and the second region 120b surrounding the first region 110b are shown in FIG. 5, And a third region 130 having a yellowish color is formed on the surface of the second region 120b having the same color. As shown in FIG. 5, the thus prepared titanium dioxide inorganic pigment particles have a first region 110c representing a yellow-based color, a first region 120b representing a blue-based color, and a yellow-based color The colors of the third region 130 are combined to form a color of pale yellow, yellow, light brown, brown, reddish brown or black-brown. It is preferable that the third region has a thickness of 0.1 to 20 nm by the oxidation reaction.

A third region which reacts with oxygen from the surface of the second region ('120a' in FIG. 4) during the oxidation treatment of the nitridation-reduced particles to form a yellowish color on the particle surface while the oxygen deficiency site is filled with oxygen, (130) is formed. The third region 130 may be composed of N-doped TiO ₂ . The third region 130, which exhibits a yellowish color, is formed to have a very thin thickness so as to have transparency. The yellow color of the first region 110c and the blue color of the second region 120b are combined to form a green, green, blue or indigo color. The third region 130 Is thin with a thickness of about 0.1 to 20 nm, green, green, blue, or indigo-colored colors appearing as a color combination of the first region 110c and the second region 120b are transmitted and can be externally colored have. Accordingly, the yellow-based color expressed in the first region 110c and the indigo-colored color expressed in the second region 120b are combined to produce a green, green, blue, or indigo-colored color, The green, green, blue or indigo-colored colors appearing by combining the colors expressed in the first region 110c and the second region 120b and the yellow-colored colors expressed in the third region 130 are color-combined, As a whole, colors such as light yellow, yellow, light brown, brown, reddish brown or black-brown can be expressed. When the particles subjected to the nitridation reduction reaction are oxidized in an oxidizing atmosphere such as air or oxygen (O ₂ ), due to the nitrogen contained in the second region ('120 a' in FIG. 4) yellow-colored N-doped TiO ₂ is formed.

_{TiO x N y (0 <x} <1, 0 <y <1) has a certain percentage (e.g., 96%) of the 2 ( '120a' in Fig. 4) area is formed to be less than or, TiO _x N _y (0 oxidation reaction is carried out with respect to a second particle having a second region ('120a' in FIG. 4) composed of N-doped TiO _{2 -x} (0 <x <1) without forming <x <1, 0 <y < And a third region 130 (nitrogen-doped TiO ₂ ) is formed on the surface of the third region 130. The thickness of the third region 130 may be controlled by controlling the oxidizing condition, and the transmittance of the second region 130 may vary depending on the thickness of the third region 130. The light transmittance is controlled according to the thickness of the third region 130 to form a light yellow, yellowish brown, brownish brown, reddish brown or reddish brown color through the color combination of the first region 110c, the second region 120b, A blackish brown color can be expressed. As the oxidation temperature and time are increased, the thickness of the third region 130 formed on the surface is increased to change the transmittance, and the color of the first region 110c and the second region 120b, which form the core portion, Yellow, light brown, brown, reddish brown, and blackish brown depending on the color combination of the first region 130 and the third region 130.

The temperature for the oxidation reaction is preferably 100 to 500 ° C, more preferably 200 to 400 ° C or so. When the temperature of the oxidation reaction is less than 100 ° C, sufficient oxidation reaction may not occur. When the temperature of the oxidation reaction exceeds 500 ° C, energy consumption is large and the second region (titanium oxide) 120b (regions expressing the indigo blue color) are all changed to yellow, so that pale yellow, yellow, light brown, brown, reddish brown or black-brown color may not be expressed. A second region 120b for expressing a blue color is required to exist in the third region 130 that exhibits a yellow color so that the color of the third region 130 may be combined with the color of the third region 130 to form a light yellow, The color of the indigo blue color expressed in the second region 120b may be changed to the color of the yellow color by the oxidation reaction. Therefore, when the oxidation is performed at a temperature of 500 ° C or less Oxidation reaction is preferable. The oxidation reaction is preferably performed for 10 minutes to 24 hours, preferably 20 minutes to 12 hours, more preferably 30 minutes to 6 hours.

It is preferable that the second region 120b has a thickness of 0.1 to 20 nm to exhibit a high transmittance. The second region 120b, which represents the color of the blue color, has a thickness of about 0.1 to 20 nm, which is very thin and has transparency. A first region 110c representing a yellow-based color, a second region 120b representing a navy-blue color having a very thin thickness and permeability, and a third region 130 representing a yellow-based color And the color of the entire system is pale yellow, yellow, light brown, brown, reddish brown or blackish brown. When the second region 120b is thicker than 20 nm, the transmittance is low, so that the colors of pale yellow, yellow, light brown, brown, reddish brown or black-brown can not be displayed due to color combination. The yellow-based color expressed in the first region 110c can be transmitted to the outside through the second region 120b and thus the yellow-based color expressed in the first region 110c, A yellowish color, a yellowish brown, a light brownish brown color, a reddish brownish brown color or a blackish brownish color may be expressed as a whole in combination with a color of a blue color expressed in the first region 120b and a color of a yellowish color expressed in the third region 130 .

It is preferable that the third region 130 has a thickness of 0.1 to 20 nm to exhibit a high transmittance. The third region 130 having a yellowish color has a thickness of about 0.1 to 20 nm, which is very thin and thus has transparency. A first region 110c representing yellow color, a second region 120b representing a blue color having a very thin thickness and permeability, a third region 120b representing a yellow color having a very thin thickness and permeability ( Yellow, light brown, brown, reddish brown or black-brown color as a whole. When the third region 130 is thicker than 20 nm, the transmittance is low and the pale yellow, yellow, light brown, brown, reddish brown or black-brown color may not be expressed by color combination. The yellow color of the first region 110c and the blue color of the second region 120b are combined to form a green, green, blue or indigo color. The third region 130 Is thin with a thickness of about 0.1 to 20 nm, green, green, blue, or indigo-colored colors appearing as a color combination of the first region 110c and the second region 120b are transmitted and can be externally colored have. Accordingly, the yellow-based color expressed in the first region 110c and the indigo-colored color expressed in the second region 120b are combined to produce a green, green, blue, or indigo-colored color, The green, green, blue or indigo-colored colors appearing by combining the colors expressed in the first region 110c and the second region 120b and the yellow-colored colors expressed in the third region 130 are color-combined, As a whole, colors such as light yellow, yellow, light brown, brown, reddish brown or black-brown can be expressed.

FIG. 11 is a view illustrating an example in which a combined color is changed by varying the transmittance as the thickness of the third yellow region changes according to the oxidation temperature.

Referring to FIGS. 5 and 11, the thickness of the third region 130 varies according to the oxidation temperature. As the oxidation temperature increases, the thickness of the third region 130 that exhibits yellow increases, It becomes. For example, when the oxidation temperature is 200 DEG C, the third region 130 has a very thin thickness, and when the oxidation temperature is 300 DEG C, the third region 130 becomes thick and yellowish.

The transmittance of the third region 130 is changed according to the thickness of the third region 130 and the refractive index of the core portion (C 'in FIG. 11) (the first region 110c and the second region 110c) The color developed through the color combination of the third region 130 and the second region 120b is different. 11) of the core portion ('C' in FIG. 11) and the third region 130 (FIG. 11) Color Shows the part that appears in combination. As the transmittance of the third region 130 is lowered from 90% to 50%, the color of the core portion ('C' in FIG. 11) and the third region 130 is changed from deep color to light color . For example, when the transmittance of the third region 130 is 90%, the color of the core portion ('C' in FIG. 11) and the third region 130 appears as a dark color, (C 'in FIG. 11) and the third region 130 are color-combined, the color appears as pale yellow, yellow or light brown.

Yellowish, yellowish brown, reddish brown, reddish brown, reddish brown, and reddish brown are obtained through condition control of the above-described nitridation reduction reaction, control of the conditions of the oxidation reaction, control of the thickness of the second region 120b, Various colors such as black and brown can be realized.

As shown in FIG. 5, the thus-prepared titanium oxide inorganic pigment particles have a first region 110c that represents a yellow color, a second region 120b that surrounds the first region 110c and exhibits an indigo color, And a third region 130 that surrounds the second region 120b and exhibits a yellowish color. The third region 130 includes a yellow color represented by the first region 110c, a blue color represented by the second region 120b, And the yellow color represented by the third region 130 are combined to form a color of pale yellow, yellow, light brown, brown, reddish brown or black-brown series as a whole. The first region 110c and the second region 120b form a core and the third region 130 forms a core portion of the shell portion 110b. shell. Yellow, light brown, brown, reddish-brown or black-brown color through the combination of the core part and the shell part.

Hereinafter, experimental examples according to the present invention will be specifically shown, and the present invention is not limited by the following experimental examples.

<Experimental Example 1>

As the raw material titanium dioxide (TiO ₂ ) particles, P25 product of Degussa Co. was prepared. Titanium dioxide particles used as raw materials represent white.

The prepared white titanium dioxide particles were charged into a reactor (rotary kiln), and subjected to nitridation reduction reaction at 450 ° C for 10 hours while flowing ammonia (NH ₃ ) gas into the reactor (rotary kiln). The reactor was heated to 450 ° C at a rate of 5 ° C / min, and the NH ₃ gas was supplied at a flow rate of 1.5 l / min.

<Experimental Example 2>

As the raw material titanium dioxide (TiO ₂ ) particles, P25 product of Degussa Co. was prepared. Titanium dioxide particles used as raw materials represent white.

The prepared white titanium dioxide particles were charged into a reactor (rotary kiln), and subjected to nitridation reduction reaction at 500 ° C for 10 hours while flowing ammonia (NH ₃ ) gas into the reactor (rotary kiln). The reactor was heated to a temperature of 500 ° C at a rate of 5 ° C / min, and the NH ₃ gas was supplied at a flow rate of 1.5 l / min.

<Experimental Example 3>

As the raw material titanium dioxide (TiO ₂ ) particles, P25 product of Degussa Co. was prepared. Titanium dioxide particles used as raw materials represent white.

The prepared white titanium dioxide particles were charged into a reactor (rotary kiln), and ammonia (NH ₃ ) gas was flowed into the reactor (rotary kiln), followed by nitridation reduction reaction at 525 ° C for 10 hours. The reactor was heated to 525 ° C at a heating rate of 5 ° C / min, and the NH ₃ gas was supplied at a flow rate of 1.5 l / min.

<Experimental Example 4>

As the raw material titanium dioxide (TiO ₂ ) particles, P25 product of Degussa Co. was prepared. Titanium dioxide particles used as raw materials represent white.

The prepared white titanium dioxide particles were charged into a reactor (rotary kiln), and subjected to nitridation reduction reaction at 550 ° C for 10 hours while flowing ammonia (NH ₃ ) gas into the reactor (rotary kiln). The reactor was heated to 550 ° C at a rate of 5 ° C / min, and the NH ₃ gas was supplied at a flow rate of 1.5 l / min.

<Experimental Example 5>

As the raw material titanium dioxide (TiO ₂ ) particles, P25 product of Degussa Co. was prepared. Titanium dioxide particles used as raw materials represent white.

The prepared white titanium dioxide particles were charged into a reactor (rotary kiln), and subjected to nitridation reduction reaction at 600 ° C for 10 hours while flowing ammonia (NH ₃ ) gas into the reactor (rotary kiln). The reactor was heated to 600 ° C at a rate of 5 ° C / min, and the NH ₃ gas was supplied at a flow rate of 1.5 l / min.

<Experimental Example 6>

As the raw material titanium dioxide (TiO ₂ ) particles, P25 product of Degussa Co. was prepared. Titanium dioxide particles used as raw materials represent white.

The prepared white titanium dioxide particles were charged into a reactor (rotary kiln) and subjected to a nitriding reduction reaction at 750 ° C for 10 hours while flowing ammonia (NH ₃ ) gas into the reactor (rotary kiln). The reactor was heated to a temperature of 750 ° C at a heating rate of 5 ° C / min, and the NH ₃ gas was supplied at a flow rate of 1.5 l / min.

<Experimental Example 7>

According to Experimental Example 1, the particles formed by nitriding reduction reaction at 450 DEG C for 10 hours were oxidized at 200 DEG C for 1 hour to form titanium oxide inorganic pigment particles. More specifically, the temperature was raised to 200 ° C at a heating rate of 5 ° C / min, an oxidation reaction was performed at 200 ° C for 1 hour while injecting air into a reactor (rotary kiln), and then naturally cooled to form titanium oxide inorganic pigment particles Respectively.

<Experimental Example 8>

The particles formed by nitriding reduction reaction at 500 ° C for 10 hours according to Experimental Example 2 were oxidized at 200 ° C for 1 hour to form titanium oxide inorganic pigment particles. More specifically, the temperature was raised to 200 ° C at a heating rate of 5 ° C / min, an oxidation reaction was performed at 200 ° C for 1 hour while air was introduced into the reactor (rotary kiln), and then naturally cooled to form titanium oxide inorganic pigment particles Respectively.

<Experimental Example 9>

According to Experimental Example 3, particles formed by nitridation reduction reaction at 525 占 폚 for 10 hours were oxidized at 200 占 폚 for 1 hour to form titanium oxide inorganic pigment particles. More specifically, the temperature was raised to 200 ° C at a heating rate of 5 ° C / min, an oxidation reaction was performed at 200 ° C for 1 hour while air was introduced into the reactor (rotary kiln), and then naturally cooled to form titanium oxide inorganic pigment particles Respectively.

<Experimental Example 10>

According to Experimental Example 4, particles formed by nitriding reduction reaction at 550 DEG C for 10 hours were oxidized at 200 DEG C for 1 hour to form titanium oxide inorganic pigment particles. More specifically, the temperature was raised to 200 ° C at a heating rate of 5 ° C / min, an oxidation reaction was performed at 200 ° C for 1 hour while air was introduced into the reactor (rotary kiln), and then naturally cooled to form titanium oxide inorganic pigment particles Respectively.

&Lt; Experimental Example 11 &

According to Experimental Example 5, the particles formed by nitriding reduction reaction at 600 占 폚 for 10 hours were oxidized at 200 占 폚 for 1 hour to form titanium oxide inorganic pigment particles. More specifically, the temperature was raised to 200 ° C at a heating rate of 5 ° C / min, an oxidation reaction was performed at 200 ° C for 1 hour while air was introduced into the reactor (rotary kiln), and then naturally cooled to form titanium oxide inorganic pigment particles Respectively.

<Experimental Example 12>

According to Experimental Example 6, the particles formed by nitriding reduction reaction at 750 占 폚 for 10 hours were oxidized at 200 占 폚 for 1 hour to form titanium oxide inorganic pigment particles. More specifically, the temperature was raised to 200 ° C at a heating rate of 5 ° C / min, an oxidation reaction was performed at 200 ° C for 1 hour while air was introduced into the reactor (rotary kiln), and then naturally cooled to form titanium oxide inorganic pigment particles Respectively.

<Experimental Example 13>

According to Experimental Example 1, the particles formed by nitriding reduction reaction at 450 占 폚 for 10 hours were oxidized at 250 占 폚 for 1 hour to form titanium oxide inorganic pigment particles. More specifically, the temperature was raised to 250 ° C at a heating rate of 5 ° C / min, an oxidation reaction was conducted at 250 ° C for 1 hour while injecting air into a reactor (rotary kiln), and then naturally cooled to form titanium oxide inorganic pigment particles Respectively.

<Experimental Example 14>

The particles formed by nitriding reduction reaction at 500 ° C for 10 hours according to Experimental Example 2 were oxidized at 250 ° C for 1 hour to form titanium oxide inorganic pigment particles. More specifically, the temperature was raised to 250 ° C at a heating rate of 5 ° C / min, an oxidation reaction was conducted at 250 ° C for 1 hour while injecting air into a reactor (rotary kiln), and then naturally cooled to form titanium oxide inorganic pigment particles Respectively.

<Experimental Example 15>

According to Experimental Example 3, the particles formed by nitriding reduction reaction at 525 ° C for 10 hours were oxidized at 250 ° C for 1 hour to form titanium oxide inorganic pigment particles. More specifically, the temperature was raised to 250 ° C at a heating rate of 5 ° C / min, an oxidation reaction was conducted at 250 ° C for 1 hour while injecting air into a reactor (rotary kiln), and then naturally cooled to form titanium oxide inorganic pigment particles Respectively.

<Experimental Example 16>

According to Experimental Example 4, the particles formed by the nitriding reduction reaction at 550 DEG C for 10 hours were oxidized at 250 DEG C for 1 hour to form titanium oxide inorganic pigment particles. More specifically, the temperature was raised to 250 ° C at a heating rate of 5 ° C / min, an oxidation reaction was conducted at 250 ° C for 1 hour while injecting air into a reactor (rotary kiln), and then naturally cooled to form titanium oxide inorganic pigment particles Respectively.

<Experiment 17>

According to Experimental Example 5, particles formed by nitriding reduction reaction at 600 占 폚 for 10 hours were oxidized at 250 占 폚 for 1 hour to form titanium oxide inorganic pigment particles. More specifically, the temperature was raised to 250 ° C at a heating rate of 5 ° C / min, an oxidation reaction was conducted at 250 ° C for 1 hour while injecting air into a reactor (rotary kiln), and then naturally cooled to form titanium oxide inorganic pigment particles Respectively.

<Experimental Example 18>

According to Experimental Example 6, the particles formed by nitriding reduction reaction at 750 占 폚 for 10 hours were oxidized at 250 占 폚 for 1 hour to form titanium oxide inorganic pigment particles. More specifically, the temperature was raised to 250 ° C at a heating rate of 5 ° C / min, an oxidation reaction was conducted at 250 ° C for 1 hour while injecting air into a reactor (rotary kiln), and then naturally cooled to form titanium oxide inorganic pigment particles Respectively.

<Experimental Example 19>

According to Experimental Example 1, the particles formed by nitriding reduction reaction at 450 DEG C for 10 hours were oxidized at 300 DEG C for 1 hour to form titanium oxide inorganic pigment particles. More specifically, the temperature was raised to 300 ° C at a heating rate of 5 ° C / min, an oxidation reaction was carried out at 300 ° C for 1 hour while air was introduced into the reactor (rotary kiln), followed by natural cooling to form titanium oxide inorganic pigment particles Respectively.

<Experimental Example 20>

The particles formed by nitridation reduction reaction at 500 ° C for 10 hours according to Experimental Example 2 were oxidized at 300 ° C for 1 hour to form titanium oxide inorganic pigment particles. More specifically, the temperature was raised to 300 ° C at a heating rate of 5 ° C / min, an oxidation reaction was carried out at 300 ° C for 1 hour while air was introduced into the reactor (rotary kiln), followed by natural cooling to form titanium oxide inorganic pigment particles Respectively.

<Experimental Example 21>

According to Experimental Example 3, the particles formed by nitriding reduction reaction at 525 ° C for 10 hours were oxidized at 300 ° C for 1 hour to form titanium oxide inorganic pigment particles. More specifically, the temperature was raised to 300 ° C at a heating rate of 5 ° C / min, an oxidation reaction was carried out at 300 ° C for 1 hour while air was introduced into the reactor (rotary kiln), followed by natural cooling to form titanium oxide inorganic pigment particles Respectively.

&Lt; Experimental Example 22 &

According to Experimental Example 4, the particles formed by the nitriding reduction reaction at 550 DEG C for 10 hours were oxidized at 300 DEG C for 1 hour to form titanium oxide inorganic pigment particles. More specifically, the temperature was raised to 300 ° C at a heating rate of 5 ° C / min, an oxidation reaction was carried out at 300 ° C for 1 hour while air was introduced into the reactor (rotary kiln), followed by natural cooling to form titanium oxide inorganic pigment particles Respectively.

<Experimental Example 23>

According to Experimental Example 5, the particles formed by the nitriding reduction reaction at 600 ° C for 10 hours were oxidized at 300 ° C for 1 hour to form titanium oxide inorganic pigment particles. More specifically, the temperature was raised to 300 ° C at a heating rate of 5 ° C / min, an oxidation reaction was carried out at 300 ° C for 1 hour while air was introduced into the reactor (rotary kiln), followed by natural cooling to form titanium oxide inorganic pigment particles Respectively.

<Experimental Example 24>

According to Experimental Example 6, the particles formed by nitriding reduction reaction at 750 占 폚 for 10 hours were oxidized at 300 占 폚 for 1 hour to form titanium oxide inorganic pigment particles. More specifically, the temperature was raised to 300 ° C at a heating rate of 5 ° C / min, an oxidation reaction was carried out at 300 ° C for 1 hour while air was introduced into the reactor (rotary kiln), followed by natural cooling to form titanium oxide inorganic pigment particles Respectively.

12 is a photograph showing the color of particles formed by the nitriding reduction reaction according to Experimental Examples 1 to 6.

Referring to FIG. 12, the particles formed by the nitriding reduction reaction according to Experimental Example 1 and Experimental Example 2 showed a yellowish color. According to Experimental Example 1, the particles formed by nitriding reduction reaction at 500 DEG C for 10 hours according to Experimental Example 2 were darker yellowish than the particles formed by nitriding reduction reaction at 450 DEG C for 10 hours.

According to Experimental Example 3, the particles formed by nitriding reduction reaction at 525 ° C for 10 hours exhibited a light blue color. The particles formed by the nitriding reduction reaction at 550 ° C for 10 hours according to Experimental Example 4, And the particles formed by nitriding reduction reaction at 600 ° C for 10 hours according to Experimental Example 5 showed a dark blue color. As the nitriding reduction temperature increased from 525 ° C to 600 ° C, it was confirmed that the color changed from light color to dark color.

The particles formed by nitriding reduction reaction at 750 ° C for 10 hours according to Experimental Example 6 showed a light black color.

When the nitridation reduction reaction is carried out at 525 and 550 ° C according to Experimental Examples 3 to 4, when the temperature is raised to about 300 to 500 ° C in the process of raising the nitridation reduction temperature, white titanium dioxide particles And reacts with ammonia (NH ₃ ) gas, whereby nitrogen is directly doped to the raw material titanium dioxide particles. In the initial stage of the nitriding reduction reaction, the titanium dioxide particles of the raw material are changed from white to yellow, As the nitridation reduction reaction continues, it is judged that the surface gradually changes from the yellow color to the indigo color. The nitrogen-doped particles are continuously exposed to the ammonia gas from the surface of the nitrogen-doped particles by a reducing atmosphere (reducing atmosphere containing a nitrogen-containing gas) depending on the nitriding reaction temperature and time, and react with oxygen to form NO _x , (oxygen defect structure). Is determined to be in accordance with the oxygen defects (oxygen defect) is balsaengdoem change occurs in the oxidation number of Ti, and the _{N-doped TiO 2 -x (0} <x <1) through the oxygen defects formed in the N-doped TiO ₂ . When TiO _{2 -x} has an x value of 1 or more, it changes to TiO _x N _y (0 <x <1, 0 <y <1) which forms a rock salt structure. During the nitridation reduction reaction in the ammonia (NH ₃ ) gas atmosphere, nitrogen is doped in the oxygen sites in the titanium dioxide particles of the raw material, and thus white particles of the titanium dioxide are yellow color, The color changes to the color of the system, and as the nitridation-reduction reaction continues, it changes from the surface of the N-doped TiO ₂ to the oxygen defect structure, the yellow color changes on the surface due to the change of the Ti oxidation number, Is formed. A second region (refer to 120a 'in FIG. 4) representing the color of the indigo color is formed on the surface of the first region (see 110b' in FIG. 4) representing the yellow color, The color of the region (see 110b in FIG. 4) and the color of the second region (see 120a in FIG. 4) representing the color of the blue color series appear in a color combination.

X-ray diffraction (XRD) analysis was performed on titanium dioxide particles as raw materials and particles formed by nitriding reduction reaction according to Experimental Examples 1 to 6, and the results are shown in Table 1 below .

Anatase Rutile Rock salt Raw material 88% 12% - Experimental Example 1 88.5% 11.5% - Experimental Example 2 89.5% 10.5% - Experimental Example 3 86.1% 13.9% - Experimental Example 4 88.0% 12.0% - Experimental Example 5 4.9% - 95.1% Experimental Example 6 - - 100%

Referring to Table 1, according to Experimental Examples 1 to 4, the anatase phase and the rutile phase were present in the particles formed under the nitriding reaction condition of 550 ° C or less, and the crystalline phase of the rock salt structure It does not exist. However, according to Experimental Example 5 and Experimental Example 6, the particles formed at a nitriding reaction temperature of 600 ° C or higher showed a crystalline phase of a rock salt structure. According to Experimental Example 5, the particles formed by nitriding reduction reaction at 600 ° C for 10 hours showed a 4.9% TiO ₂ crystal phase (anatase crystal phase) and a 95.1% rock salt structure crystal phase. From this, it is judged that the TiO ₂ crystal phase begins to transform into a crystalline phase of rock salt structure above 600 ° C. Particularly, at a temperature of 750 ° C. or higher, it is transformed into a rock salt structure by 100% _x N _y (0 <x <1, 0 <y <1).

13 is a photograph showing the color of titanium oxide inorganic pigment particles formed by oxidation reaction according to Experimental Examples 7 to 24. FIG.

Referring to FIG. 13, particles formed by nitriding reduction reaction at 450 ° C. for 10 hours according to Experimental Example 1 were treated at 200 ° C., 250 ° C. and 300 ° C. for 1 hour Titanium oxide inorganic pigment particles formed by oxidation reaction were white or pale yellow.

Particles formed by nitriding reduction reaction at 500 ° C for 10 hours according to Experimental Example 2 were formed by oxidation reaction at 200 ° C, 250 ° C and 300 ° C for 1 hour according to Experimental Example 8, Experimental Example 14 and Experimental Example 20 Titanium oxide inorganic pigment particles showed light yellow.

Titanium oxide inorganic pigment particles formed by oxidation reaction at 250 ° C according to Experimental Example 13 and Experimental Example 14 rather than titanium oxide inorganic pigment particles formed by oxidation reaction at 200 ° C according to Experimental Example 7 and Experimental Example 8 had a lighter color Respectively. Titanium oxide inorganic pigment particles formed by oxidation reaction at 300 ° C according to Experimental Example 19 and Experimental Example 20 rather than titanium oxide inorganic pigment particles formed by oxidation reaction at 250 ° C according to Experimental Example 13 and Experimental Example 14 had a lighter color Respectively. From this, it was confirmed that the color of the titanium oxide inorganic pigment particle changes according to the oxidation temperature. As the oxidation temperature increased, it was confirmed that the titanium oxide inorganic pigment particles exhibited a lighter hue.

Particles formed by nitriding reduction reaction at 520 ° C for 10 hours according to Experimental Example 3 were oxidized at 200 ° C, 250 ° C and 300 ° C for 1 hour according to Experimental Examples 9, 15 and 21, respectively Titanium oxide inorganic pigment particles showed flesh color (pale yellow) to pale yellow. As the oxidation temperature increased to 200 ° C, 250 ° C and 300 ° C, it was confirmed that the titanium oxide inorganic pigment particles showed lighter color.

Particles formed by nitriding reduction reaction at 550 ° C for 10 hours according to Experimental Example 4 were oxidized at 200 ° C, 250 ° C and 300 ° C for 1 hour according to Experimental Example 10, Experimental Example 16 and Experimental Example 22, respectively Titanium oxide inorganic pigment particles showed brown to pale yellow. As the oxidation temperature increased to 200 ° C, 250 ° C and 300 ° C, it was confirmed that the titanium oxide inorganic pigment particles showed lighter color.

Particles formed by nitriding reduction reaction at 600 ° C for 10 hours according to Experimental Example 5 were oxidized at 200 ° C, 250 ° C and 300 ° C for 1 hour according to Experimental Examples 11, 17 and 23, respectively Titanium oxide inorganic pigment particles showed blackish brown, reddish brown, and yellow (flesh color). As the oxidation temperature increased to 200 ° C, 250 ° C and 300 ° C, it was confirmed that the titanium oxide inorganic pigment particles showed lighter color.

Particles formed by nitriding reduction reaction at 750 ° C for 10 hours according to Experimental Example 6 were oxidized at 200 ° C, 250 ° C and 300 ° C for 1 hour according to Experimental Example 12, Experimental Example 18 and Experimental Example 24, respectively Titanium oxide inorganic pigment particles showed black color.

X-ray diffraction (XRD) analysis was performed on the titanium oxide inorganic pigment particles formed by the oxidation reaction according to Experimental Examples 7 to 24, and the results are shown in Table 2 below.

Oxidation temperature (℃) Anatase Rutile Rock salt Experimental Example 7 200 92.4% 7.6% - Experimental Example 13 250 91.9% 8.1% - Experimental Example 19 300 89.5% 10.5% - Experimental Example 8 200 87.2% 12.8% - Experimental Example 14 250 88.0% 12.0% - Experimental Example 20 300 91.9% 8.1% - Experimental Example 9 200 84.5% 15.5% - Experimental Example 15 250 86.9% 13.1% - Experimental Example 21 300 87.9% 12.1% - Experimental Example 10 200 84.6% 15.4% - Experimental Example 16 250 85.5% 14.5% - Experimental Example 22 300 87.4% 12.6% - Experimental Example 11 200 56.5% 11.5% 32.0% Experimental Example 17 250 75.2% 13.4% 11.4% Experimental Example 23 300 83.8% 16.2% - Experimental Example 12 200 - - 100% Experimental Example 18 250 - - 100% Experimental Example 24 300 46.5% - 53.5%

When particles subjected to a nitriding reduction reaction at a temperature of 550 ° C or lower (particles obtained by nitriding reduction reaction according to Experimental Examples 1 to 4) were subjected to oxidation reaction, no salt structure was formed and the same X- The diffraction (XRD) pattern was maintained.

The particles obtained by the nitriding reduction reaction at 600 ° C (the particles obtained by the nitriding reduction reaction according to Experimental Example 5) had a ratio of the salt salt structure of 95.1%. When the particles were oxidized (Experimental Example 11, Experimental Example 17 and Experimental Example 23) The ratio of rock salt structure decreased, and as the oxidation temperature increased, the ratio of rock salt structure decreased further. More specifically, the titanium dioxide inorganic pigment particles formed by the oxidation reaction at 200 ° C. according to Experimental Example 11 had a rock salt structure ratio of 32.0%, and the oxidation occurred at 250 ° C. according to Experimental Example 17 The ratio of the rock salt structure of the titanium inorganic pigment particles was 11.4%, and the proportion of the rock salt structure of the titanium oxide inorganic pigment particles formed by the oxidation reaction at 300 ° C according to Experimental Example 23 was 0%. (Examples 11, 17, and 23) were subjected to a nitriding reduction reaction at 600 ° C (particles obtained by nitriding reduction reaction according to Experimental Example 5) Reddish brown, and yellow (fleshy) colors.

However, the particles obtained by the nitriding reduction reaction at 750 ° C (particles obtained by the nitriding reduction reaction according to Experimental Example 6) showed black color as shown in FIG. 12, and the ratio of the salt salt structure was 100% as shown in Table 1, 100%, and 53.5%, respectively, in the oxidation reaction (Experimental Example 12, Experimental Example 18 and Experimental Example 24). As shown in FIG. 13, titanium oxide inorganic pigment particles formed by oxidation reaction at 200 ° C. according to Experimental Example 12 showed black color, and titanium oxide inorganic pigment particles formed by oxidation reaction at 250 ° C. according to Experimental Example 18 Black, and titanium oxide inorganic pigment particles formed by oxidation reaction at 300 ° C according to Experimental Example 24 showed a light black color. The particles (obtained by nitriding reduction reaction according to Experimental Example 6) produced by nitriding and reducing treatment at 750 ° C had a rock salt structure ratio of 100%. Even at a high oxidation temperature of 300 ° C, Respectively. Yellow, light brown, brown, reddish-brown, or black-brown color, even though the particles produced by the nitriding-reduction treatment at 750 ° C (particles showing black as the particles obtained by the nitriding reduction reaction according to Experimental Example 6) It is impossible to control the thickness of the third region 130 formed on the surface to be controlled to a desired color.

14 and Table 3 show the color evaluation results using the colorimeter of the particles produced through the nitriding reduction reaction according to Experimental Examples 1 to 6. In FIG. 14, 'No 1' refers to particles formed by nitriding reduction reaction at 450 ° C. for 10 hours according to Experimental Example 1, and 'No 2' is nitridation reduction reaction at 500 ° C. for 10 hours according to Experimental Example 2 'No 3' is for particles formed by nitriding reduction reaction at 525 ° C. for 10 hours according to Experimental Example 3, 'No 4' is for particles formed at 550 ° C. for 10 hours according to Experimental Example 4 No 5 'is for particles formed by nitriding reduction reaction at 600 ° C. for 10 hours according to Experimental Example 5, and' No 6 'is for particles formed by nitridation reduction reaction at 750 ° C. For 10 hours. &Lt; tb &gt; &lt; TABLE &gt;

Nitridation reduction temperature L * a * b * Experimental Example 1 450 ℃ 89.51 -3.46 4.54 Experimental Example 2 500 ℃ 90.72 -4.59 9.12 Experimental Example 3 525 ° C 58.46 -5.73 -4.39 Experimental Example 4 550 ℃ 39.31 -1.25 -6.64 Experimental Example 5 600 ℃ 36.24 -0.31 -4.83 Experimental Example 6 750 ℃ 34.04 0.68 -1.91

14 and Table 3, L * denotes brightness, a * denotes the X-axis of the saturation coordinate, and b * denotes the y-axis of the saturation coordinate. According to Experimental Examples 1 to 6, L * was 89.51 to 34.04, a * was -5.63 to 0.68, and b * was -6.64 to 9.12.

The color evaluation results of the titanium oxide inorganic pigment particles formed by the oxidation reaction according to Experimental Examples 7 to 12 are shown in Figs. 15 and 4. Fig. 15 shows the titanium oxide inorganic pigment particles formed by oxidation reaction at 200 ° C. according to Experimental Example 7, and particles formed by nitriding reduction reaction at 450 ° C. for 10 hours according to Experimental Example 1, No 2 'refers to titanium oxide inorganic pigment particles formed by oxidation reaction at 200 ° C. according to Experimental Example 8, and particles formed by nitriding reduction reaction at 500 ° C. for 10 hours according to Experimental Example 2, and' No 3 ' No 4 'is the inorganic oxide particle formed by nitriding reduction reaction at 525 ° C according to Experimental Example 3 for 10 hours by oxidation reaction at 200 ° C according to Experimental Example 9, and' No 4 ' And the particles formed by nitriding reduction reaction at 550 ° C for 10 hours were subjected to oxidation reaction at 200 ° C according to Experimental Example 10, and 'No 5' 10 hours Quot; No 6 &quot; refers to titanium oxide inorganic pigment particles formed by oxidation reaction at 200 ° C according to Experimental Example 11, and 'No 6' corresponds to the nitridation reduction reaction at 750 ° C for 10 hours according to Experimental Example 6 To titanium oxide inorganic pigment particles formed by oxidation reaction at 200 ° C according to Experimental Example 12.

Nitridation reduction temperature L * a * b * Experimental Example 7 450 ℃ 91.85 -3.17 5.97 Experimental Example 8 500 ℃ 91.17 -3.89 8.63 Experimental Example 9 525 ° C 74.02 2.71 12.18 Experimental Example 10 550 ℃ 48.78 0.9 6.18 Experimental Example 11 600 ℃ 39.44 -1.02 -0.63 Experimental Example 12 750 ℃ 34.44 0.2 -2.32

15 and Table 4, the titanium oxide inorganic pigment particles formed by the oxidation reaction according to Experimental Examples 7 to 12 had L * of 91.85 to 34.44, a * of -3.89 to 2.71, and b * of -2.32 I could implement a color that represented a value of 12.18.

The color evaluation results of the titanium oxide inorganic pigment particles formed by the oxidation reaction according to Experimental Examples 13 to 18 are shown in FIG. 16 and Table 5. FIG. 16 shows the titanium oxide inorganic pigment particles formed by oxidation reaction at 250 ° C. according to Experimental Example 13, and the particles formed by nitriding reduction reaction at 450 ° C. for 10 hours according to Experimental Example 1, No 2 'refers to the titanium oxide inorganic pigment particles formed by nitriding reduction reaction at 500 ° C for 10 hours according to Experimental Example 2, by oxidation reaction at 250 ° C according to Experimental Example 134, and' No 3 ' The particles formed by the nitriding reduction reaction at 525 ° C according to Example 3 were formed by titanium oxide inorganic pigment particles formed by oxidation reaction at 250 ° C according to Experimental Example 15, and 'No 4' Deg.] C for 10 hours according to Experimental Example 16, and 'No 5' for titanium oxide inorganic pigment particles formed by oxidation reaction at 250 &lt; 0 &gt; C according to Experimental Example 16,No 6 'for inorganic pigment particles formed by oxidation reaction at 250 ° C according to Experimental Example 17, and' No 6 'for 10 hours at 750 ° C according to Experimental Example 6 To titanium oxide inorganic pigment particles formed by oxidation reaction at 250 ° C. according to Experimental Example 18.

Nitridation reduction temperature L * a * b * Experimental Example 13 450 ℃ 94.41 -2.47 4.23 Experimental Example 14 500 ℃ 91.15 -4.03 8.44 Experimental Example 15 525 ° C 90.41 -1.81 12.02 Experimental Example 16 550 ℃ 59.84 6.27 12.77 Experimental Example 17 600 ℃ 46.36 4.35 8.01 Experimental Example 18 750 ℃ 35.08 0.03 -2.52

16 and Table 5, the titanium oxide inorganic pigment particles formed by the oxidation reaction according to Experimental Examples 13 to 18 had L * of 94.41 to 35.08, a * of -4.03 to 6.27, and b * of -2.52 A color representing a value of 12.77 may be implemented.

The color evaluation results of the titanium oxide inorganic pigment particles formed by the oxidation reaction according to Experimental Examples 19 to 24 are shown in FIGS. 17 and 6. FIG. In FIG. 17, 'No 1' refers to titanium oxide inorganic pigment particles formed by oxidation reaction at 300 ° C. according to Experimental Example 19, and particles formed by nitriding reduction reaction at 450 ° C. for 10 hours according to Experimental Example 1, No 2 'refers to titanium oxide inorganic pigment particles formed by nitriding reduction reaction at 500 ° C for 10 hours according to Experimental Example 2, and the particles formed by oxidation reaction at 300 ° C according to Experimental Example 20, and' No 3 ' The particles formed by nitriding reduction reaction at 525 ° C according to Experimental Example 3 for 10 hours were subjected to oxidation reaction at 300 ° C according to Experimental Example 21, and 'No 4' And the particles formed by nitriding reduction reaction at 550 ° C for 10 hours were subjected to oxidation reaction at 300 ° C according to Experimental Example 22, and 'No 5' 10:00 Quot; No 6 &quot; refers to titanium oxide inorganic pigment particles formed by oxidation reaction at 300 ° C according to Experimental Example 23, and 'No 6' corresponds to the nitridation reduction reaction at 750 ° C for 10 hours according to Experimental Example 6 And titanium oxide inorganic pigment particles formed by oxidation reaction at 300 ° C according to Experimental Example 24.

Nitridation reduction temperature L * a * b * Experimental Example 19 450 ℃ 92.53 -2.31 3.65 Experimental Example 20 500 ℃ 94.5 -3.16 6.64 Experimental Example 21 525 ° C 91.71 -3.57 11.81 Experimental Example 22 550 ℃ 94.22 -3.84 14.96 Experimental Example 23 600 ℃ 80.75 2.66 19.31 Experimental Example 24 750 ℃ 41.4 -1.06 -0.82

17 and Table 6, the titanium oxide inorganic pigment particles formed by the oxidation reaction according to Experimental Examples 19 to 24 had L * of 94.22 to 41.4, a * of -3.84 to 2.66 and b * of -0.82 I could implement a color that represented a value of 19.31.

<Experimental Example 25>

To confirm the structure of the synthesized titanium oxide inorganic pigment particle, an H ₃ PO ₄ etchant capable of etching the surface was prepared.

0.01 g of the particles formed by the nitriding reduction reaction at 550 ° C according to Experimental Example 4 were dispersed in 30 ml of the H ₃ PO ₄ etchant, and the mixture was stirred at the time (0 minutes, 10 minutes, 20 minutes, 30 minutes, 60 minutes) And the change in color was observed, as shown in Fig.

Further, titanium oxide inorganic pigment particles formed by oxidation reaction at 200 ° C for 1 hour in accordance with Experimental Example 10 (titanium oxide formed by oxidation reaction of particles formed by nitriding reduction reaction at 550 ° C for 10 hours in accordance with Experimental Example 4) Inorganic pigment particles) was dispersed in 30 ml of the H ₃ PO ₄ etchant and observed for color change with time (0 min, 10 min, 20 min, 30 min, 60 min).

Finally, the dispersion solutions, which were etched for 60 minutes, were observed by filtration using an AAO (Anodic Aluminum Oxide) filter and shown in FIG.

Referring to FIG. 18, the particles formed by the nitriding reduction reaction according to Experimental Example 4, the second region 120a having an oxygen-deficient structure formed on the surface is removed over time, And finally observed.

In addition, the titanium oxide inorganic pigment particles formed by the oxidation reaction according to Experimental Example 10, the third region 130 was removed at the beginning of etching and the core portion composed of the first region 110c and the second region 120b was derived, The second region 120b is removed while the etching time is increased, and the color of the first region 110c finally appears.

When the dispersion solution in which the particles formed by nitriding reduction reaction according to Experimental Example 4 were etched for 60 minutes was observed by filtration using an AAO (Anodic Aluminum Oxide) filter, the deep yellow of the first region 110b Respectively.

In addition, when the dispersion solution in which the titanium oxide inorganic pigment particles formed by the oxidation reaction according to Experimental Example 10 was etched for 60 minutes was observed by filtration using AAO (Anodic Aluminum Oxide) filter, And a dark yellow color was observed on the surface 110c.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention.

110c:
120b: second region
130: third region

Claims (22)

A first region indicating a yellow color;
A second region surrounding the first region and representing a color of a blue color series; And
And a third region surrounding the second region and representing a yellow color,
The color of the yellow series represented by the first region, the color of the indigo series represented by the second region, and the color of the yellow series represented by the third region are combined to form a total of light yellow, yellow, light brown, brown, reddish brown, , &Lt; / RTI &gt;
Wherein the first region is comprised of N-doped TiO ₂ ,
The second region is composed of N-doped TiO _2-x (0 <x <1) and TiO _x N _y (0 <x <1, 0 <y <1) having a rock salt structure,
And the third region is comprised of N-doped TiO ₂ .
The method of claim 1, wherein the first region is formed by nitrogen-doped titanium dioxide particles in a white state by a nitridation-reduction reaction and the white titanium dioxide particles are changed to a yellow-
Wherein the second region is a region formed by changing the surface of the first region exhibiting the yellowish color to a color of the indigo color by the nitridation reduction reaction,
Wherein the third region is a region formed by the oxidation of the surface of the second region, which shows the color of the indigo blue series, to a yellow-based color.
delete delete delete The method according to claim 1, wherein the TiO _x N _y (0 <x <1, 0 <y <1) forming a rock salt structure is present in the second region at a rate lower than 40% Titanium oxide inorganic pigment particles.
The titanium oxide inorganic pigment particle according to claim 1, wherein the second region is a region having a thickness of 0.1 to 20 nm and a transmittance.
The titanium oxide inorganic pigment particle according to claim 1, wherein the third region is a region having a thickness of 0.1 to 20 nm and a transmittance.
The titanium oxide inorganic pigment particle according to claim 1, wherein the titanium oxide inorganic pigment particle has a particle diameter of 10 to 300 nm.
(a) preparing white titanium dioxide particles as a raw material;
(b) charging the titanium dioxide particles into a reactor and nitriding and reducing the gas while flowing a nitrogen-containing gas into the reactor to form first particles exhibiting a yellowish color;
(c) nitriding-reducing the first particles exhibiting the yellow-based color to form a second region showing a color of the indigo system on the surface of the first particles showing a yellow-based color, thereby forming a first Forming a second particle having a region and a second region surrounding the first region and having a color of a blue color; And
(d) causing the second particles to be oxidized to form a third region having a yellowish color on the surface of the second region exhibiting a blue color,
The color of the yellow series represented by the first region, the color of the indigo series represented by the second region, and the color of the yellow series represented by the third region are combined to form a total of light yellow, yellow, light brown, brown, reddish brown, Lt; / RTI &gt;
Wherein the first region is comprised of N-doped TiO ₂ ,
The second region is composed of N-doped TiO _2-x (0 <x <1) and TiO _x N _y (0 <x <1, 0 <y <1) having a rock salt structure,
Wherein the third region is comprised of N-doped TiO ₂ .
[10] The method of claim 10, wherein the first region is a region formed by doping nitrogen into titanium dioxide particles by nitridation-reduction reaction in the step (b) to change the white titanium dioxide particles to a yellowish color,
Wherein the second region is a region formed by changing the surface of the first region exhibiting the yellow-based color to the color of the indigo blue by the nitridation-reduction reaction in the step (c)
Wherein the third region is a region in which the surface of the second region exhibiting the blue color is changed to a yellow color by the oxidation reaction in the step (d). Way.
delete delete delete The method according to claim 10, wherein the TiO _x N _y (0 <x <1, 0 <y <1) forming a rock salt structure is present in the second region at a rate lower than 40% Titanium oxide inorganic pigment particles.
11. The method of claim 10, wherein the second region is a region having a thickness of 0.1 to 20 nm and a transmittance.
11. The method of claim 10, wherein the third region is a region having a thickness of 0.1 to 20 nm and a transmittance.
The method according to claim 10, wherein the nitridation reduction reaction in step (b) is performed at a temperature of 300 to 500 캜.
The method according to claim 10, wherein the nitridation-reduction reaction in step (c) is performed at a temperature of 510 to 700 캜, which is higher than the temperature of the nitridation-reduction reaction in step (b).
The method according to claim 10, wherein the oxidation reaction is performed at a temperature of 100 to 500 캜.
11. The method for producing titanium oxide inorganic pigment particles according to claim 10, wherein the titanium dioxide particles are particles of white having a particle diameter of 10 to 300 nm.
11. The method according to claim 10, wherein the titanium oxide inorganic pigment particles have a particle diameter of 10 to 300 nm.

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