KR20210026892A - Inorganic fluorescence, and pearlescent pigment comprising the same - Google Patents

Abstract

The present invention relates to an inorganic fluorescent substance and a pearlescent pigment including the same, and the fluorescent substance according to an embodiment of the present invention includes a material represented by General Formula 1. [General Formula 1] (A_a, B_b, C_c, D_d)O_f (A is Ce or Gd, B is at least one of Gd, Zr, Ti, and La when A is Ce, B is Ce when A is Gd, C is one of an alkali metal, D is at least one of Ho, Yb, Er, and Tm, 1<=a+b+c+d<=2, 0<a<2, 0.005<=b<=0.3, 0<=c<=0.1, 0<d<=0.1, and 2<=f<=3). Accordingly, an average particle size is small, and a luminescent property is excellent.

Description

Inorganic phosphor, and pearlescent pigment containing the same {INORGANIC FLUORESCENCE, AND PEARLESCENT PIGMENT COMPRISING THE SAME}

The present invention relates to an inorganic phosphor, and a pearlescent pigment comprising the same, and more specifically, an inorganic phosphor exhibiting an up-conversion effect by simultaneously containing Ce and Gd, and its fluorescence characteristics, indirect color, and metallic luster effect. It relates to a pearlescent pigment having an aesthetic effect.

Pearlescent pigment is a collective term for pigments that give off pearly, iridescent and metallic colors, and the most widely used pearlescent pigment in the market today is a natural mica titanium pigment that appeared in the mid-1960s. _{This pigment is coated with TiO 2} on the mica surface with a uniform thickness, and has many advantages such as non-toxicity, chemical resistance, and non-conductivity, and is thus widely used in all areas of the processing industry including cosmetics. The application field of pearlescent pigment can be largely divided into industrial (paint, wallpaper, construction materials, etc.), automobile (automobile paint, architectural exterior materials, etc.), cosmetics (basic cosmetics, color cosmetics, etc.), and currency.

As a manufacturing technology for such pigments, pearlescent pigments having excellent luster and saturation are produced by coating metal oxides such as iron oxide and pigments such as organic phosphors and inorganic phosphors on a plate-like substrate for industrial use, automobiles, cosmetics, and money. The technology to be used in the etc. is required.

A phosphor is a material that converts absorbed light into light of a different wavelength and emits it, and an inorganic phosphor refers to a phosphor made of an inorganic compound. Up-conversion (UC) phosphor receives light of low energy (infrared light) and emits light of higher energy (visible light). The process of producing such visible light is called luminescence.Active ions absorb light energy in the ground state and transition to the metastable level, and then absorb another light energy before returning to the ground state, resulting in higher energy. Transition to the state. An up-conversion fluorescent substance includes, for example doped with rare earth ions to halide matrix NaYF _4: Er, Yb, doped with a rare earth ion in the oxide-based matrix _{Gd 2 O 3: Er, Yb} , or CeO _2: Er, Y _b Etc.

However, since the conventional up-conversion phosphor has insufficient luminescence properties or uses an undesirable material such as fluoride, it is necessary to develop a new composition that produces satisfactory results in terms of luminance, luminescence color, color purity, or visibility.

In addition, conventional CeO ₂ and Gd ₂ O ₃ It is necessary to develop a new composition in consideration of the stoichiometric ratio with improved properties such as luminance than that used as the base material.

Korean Patent Application Publication No. KR 10-2011-0130117 Japanese Unexamined Patent Application Publication No. 2013-60568

An object of the present invention is to provide an inorganic phosphor having a small average particle size and excellent luminescence characteristics by simultaneously including Ce and Gd in a specific composition ratio.

In addition, the present invention is to prepare a pearlescent pigment that emits light at a specific wavelength in infrared light while having an aesthetic effect through an indirect color and metallic luster effect by coating the inorganic phosphor, and having increased color purity, visibility, and light intensity. The purpose.

The phosphor according to an embodiment of the present invention includes a material represented by the following general formula (1).

[General Formula 1] (A _a , B _b , C _c , D _d ) O _f

(In the general formula 1, A is Ce or Gd, when A is Ce, B is at least one of Gd, Zr, Ti, and La, when A is Gd, B is Ce, C is any one of alkali metals, D is At least any one of Ho, Yb, Er, and Tm, 1≤a+b+c+d≤2, 0<a<2, 0.005≤b≤0.3, 0≤c≤0.1, 0<d≤0.1, 2 ≤f≤3).

In the phosphor according to an embodiment of the present invention, in the general formula 1, A is Ce, B is Gd, and D is Ho and Yb, and in this case, the ratio of the number of atoms of Ho is d1, and the ratio of the number of atoms of Yb is d2. In this case, 0.005≦b≦0.05, 0.001≦d1≦0.005, and 0.01≦d2≦0.03 may be satisfied.

In the phosphor according to an embodiment of the present invention, in the general formula 1, A is Ce, B is Gd, C is Na, and D is Ho and Yb, and in this case, the ratio of the number of atoms of Ho is d1 and the number of atoms of Yb. When the ratio is d2, 0.005≦b≦0.03, 0.01≦c≦0.035, 0.001≦d1≦0.005, and 0.01≦d2≦0.03 may be satisfied.

In the phosphor according to an embodiment of the present invention, in the general formula 1, A is Ce, B is Gd, C is Li, and D is Ho and Yb, and the ratio of the number of atoms of Ho is d1 and the ratio of the number of atoms of Yb is In the case of d2, 0.005≦b≦0.03, 0.02≦c≦0.1, 0.001≦d1≦0.005, and 0.01≦d2≦0.03 may be satisfied.

In the phosphor according to an embodiment of the present invention, A may be Ce and B may be Zr in General Formula 1 above.

In the phosphor according to an embodiment of the present invention, in the general formula 1, when A is Gd, B is Ce, D is Ho and Yb, the ratio of the number of atoms of Ho is d1, and the ratio of the number of atoms of Yb is d2, The 0.005≦b≦0.3, 0.002≦d1≦0.006, and 0.04≦d2≦0.08 may be satisfied.

The phosphor according to an embodiment of the present invention is characterized in that when irradiated with infrared rays having a wavelength of 980 nm, the emission wavelength is 510 to 580 nm.

The phosphor according to an embodiment of the present invention may have an average particle size D50 of 200 nm or less.

A pearlescent pigment according to an embodiment of the present invention is a base material; And a phosphor represented by the following general formula 1 according to the present invention coated on the substrate.

[General Formula 1] (A _a , B _b , C _c , D _d ) O _f

(In the general formula 1, A is Ce or Gd, when A is Ce, B is at least one of Gd, Zr, Ti, and La, when A is Gd, B is Ce, C is any one of alkali metals, D is At least any one of Ho, Yb, Er, and Tm, 1≤a+b+c+d≤2, 0<a<2, 0.005≤b≤0.3, 0≤c≤0.1, 0<d≤0.1, 2 ≤f≤3).

In the pearlescent pigment according to an embodiment of the present invention, the substrate is coated with a metal oxide on a flake substrate, and the flake substrate is synthetic mica, natural mica, glass flake, plate-shaped iron oxide, plate-shaped alumina, aluminum flake, plate-shaped It contains at least one or more of silica, talc, and bismuth, and the metal of the metal oxide is silicon (Si), titanium (Ti), zirconium (Zr), antimony (Sb), zinc (Zn), and tin (Sn) , Iron (Fe), magnesium (Mg), manganese (Mn), aluminum (Al), cobalt (Co), and may contain at least one or more of barium (Ba).

In the pearlescent pigment according to an embodiment of the present invention, the substrate may be alumina (Al ₂ O ₃ ) coated with titanium oxide (TiO _{2 ).}

In the pearlescent pigment according to an embodiment of the present invention, the coating thickness of the phosphor of claim 1 coated on the substrate may be 10 to 500 nm.

The pearlescent pigment according to the embodiment of the present invention may emit light at a wavelength of 510 to 580 nm when irradiated with infrared rays having a wavelength of 980 nm.

The inorganic phosphor according to the embodiment of the present invention has a small average particle size and excellent luminescence characteristics, and the pearlescent pigment according to the embodiment of the present invention has an aesthetic effect through an indirect color and metallic luster effect, and a specific wavelength in infrared rays. It emits light, and color purity, visibility, and luminous intensity are increased.

1 is a graph comparing the luminescence characteristics of Comparative Examples 1-1 and 1-2, Examples 1-1, and 1-5.
1 is a luminescence spectrum and a photograph of luminescence showing while changing the b value in the phosphor prepared in Example 1-1.
2 is a light emission spectrum and a light emission photograph showing while changing the c value in the phosphor prepared in Example 1-2.
3 is a light emission spectrum and a light emission photograph shown while changing the c value in the phosphor prepared in Example 1-3.
FIG. 4 is an emission spectrum and photo emission showing a case of a Zr-doped plate in the phosphor prepared in Example 1-4.
5 is a light emission spectrum and a light emission photograph showing while changing the b value in the phosphor prepared in Example 1-5.

Hereinafter, the present invention will be described in more detail through examples. Since these examples are for illustrative purposes only, the scope of the present invention is not to be construed as being limited by these examples.

Expressions such as "comprising" used in the present specification are understood as open-ended terms including the possibility of including other embodiments, unless specifically stated otherwise in the phrase or sentence in which the expression is included. It should be.

As used herein, "preferable" and "preferably" refer to embodiments of the present invention that may provide certain advantages under certain circumstances. However, under the same or different circumstances, other embodiments may also be desirable. Additionally, reference to one or more preferred embodiments does not imply that other embodiments are not useful, and is not intended to exclude other embodiments from the scope of the present invention.

In the present specification, when a member is positioned “on” another member, this includes not only a case where a member is in contact with another member, but also a case where another member exists between the two members.

The phosphor according to an embodiment of the present invention includes a material represented by the following general formula (1).

[General Formula 1] (A _a ,B _b ,C _c ,D _d )O _f

(A is Ce or Gd,

When A is Ce, B is at least one of Gd, Zr, Ti, and La,

When A is Gd, B is Ce, C is any one of alkali metals,

D is at least any one of Ho, Yb, Er, and Tm,

1≤a+b+c+d≤2, 0<a<2, 0.005≤b≤0.3, 0≤c≤0.1, 0<d≤0.1, 2≤f≤3).

In general, the light absorption and light emission characteristics of a phosphor depend on the absorption characteristics of the parent body. In addition, it is important to select a parent body having thermal stability applied in the manufacturing process, and when considering this, the parent body according to the embodiment of the present invention is at least one selected from the group consisting of Ce/La, Gd, Zr, and Ti. It is composed of the above substances/O.

When the phosphor according to the embodiment of the present invention is coated on the surface of the Gd-based inorganic particle, the phosphor of the present invention has a particle size smaller than that of the conventional Ce-based phosphor, and thus is evenly distributed compared to the conventional one. On the other hand, when the Ce-based inorganic particles are coated, the pearl characteristics are increased compared to the Gd-based. Therefore, in the present invention, it is required to select a ratio of the number of atoms that take advantage of each of the inorganic particles so as to improve the coating quality while increasing the pearl properties.

This phosphor is a mixture of any one or two or more of Ho, Yb, Er, and Tm in a parent body consisting of at least one or more substances selected from the group consisting of Ce/ Gd, Zr, Ti, and La/ O (oxygen) Activator is doped.

The phosphor satisfying the above relationship may be one in which B ions are added or B ions are substituted instead of A ions in a crystal lattice made of A and O. The a value, which represents the ratio of the number of atoms of A, is a value determined from the relationship between the ratio of the number of atoms of other ions and the number of oxidation with O, and the value of f, which represents the ratio of the number of atoms of O, is related to the relationship with the number of oxidation of other ions Is determined by yourself.

The b value representing the ratio of the number of atoms of B ions added should be 0.005 to 0.3. If it is out of the range of 0.005 to 0.3, the light emission intensity becomes weaker and the average particle size increases. In addition, when considering the luminescence characteristics and the particle size of the fluorescent particles, the b value may be 0.005 to 0.2, may be 0.01 to 0.1, and may be 0.01 to 0.05.

When a material consisting of Ce and O is doped with a small amount of at least one of Gd, Zr, Ti, and La as a mother body, or a material consisting of Gd and O contains a small amount of Ce or doped with a small amount of Ce as a mother body. In this case, the effect is increased in terms of light absorption and luminescence properties than in the case of using a material composed of Ce and O or a material composed of Gd and O as a parent body.

The phosphor according to an embodiment of the present invention may further include C, which is at least one or more of Li, Na, and K as an alkali metal. When the C is further included, it is possible to improve light emission characteristics, but it is necessary to select a ratio of the number of atoms within a range that does not impair luminance. Considering this, the c value may be 0 to 0.1, more preferably 0.01 to 0.08, more preferably 0.02 to 0.06, more preferably 0.03 to 0.05, but this corresponds to A, B, C, D. It may vary depending on the ratio of the element and the number of atoms of each element.

The phosphor according to an embodiment of the present invention is doped with rare earth metal ions such as Ho, Yb, Er, and Tm as a dopant D in the parent body. The dopant may be selected in consideration of the wavelength and luminance of the emission color. The d value representing the ratio of the number of atoms of the dopant is added in the range of 0 to 0.1.

When light of a specific wavelength is irradiated, visible light is emitted from the up-conversion phosphor, and at this time, light is emitted in a different color depending on the type of doped earth ions. For example, when only Ho or Ho and Yb are used as dopants, green light emission occurs. In addition, when the colored light of a phosphor emitting a plurality of color lights is visually recognized, it is observed as a mixed color. Therefore, it is possible to emit light of a desired color by appropriately adjusting the type and quantity ratio of the dopant. As an example, by mixing Ho and Yb at a specific stoichiometric ratio to be described later, a phosphor emitting light at around 550 nm may be prepared. In addition, other rare earth metal ions may be doped instead of Ho and Yb to give different colors of different wavelengths.

The dopant may exist in any form in the parent body and may be substituted for an element constituting the parent crystal lattice, or may be mixed with an element constituting the parent crystal lattice. Ho, Yb, Er, and Tm, which are dopants according to an embodiment of the present invention, are uniformly distributed in the phosphor.

The phosphor according to an embodiment of the present invention may be prepared by spray pyrolysis. Spray pyrolysis is a solution of dissolving a precursor into droplets of several microns to tens of microns. After spraying, the solvent is evaporated and the precipitated precursor is pyrolyzed to produce particles and films. However, other than the spray pyrolysis method, there are no special restrictions on the manufacturing method, such as the solid phase method or the liquid phase method.

The size of the phosphor particles according to the embodiment of the present invention may be any size that can be coated on a plate-like substrate, but more preferably, it is preferably a nano size. In the nano-sized phosphor according to an embodiment of the present invention, the particles may be 300 nm or less, more preferably 250 nm or less, more preferably 200 nm or less, or 150 nm or less, or 100 nm or less. The particle size of the phosphor can be manufactured to a size of 300 nm or less through the process of nano-dispersing.

In the case of a phosphor having a particle size of 300 nm or more, when coated on A-901K, which will be described later, it is not coated on the surface and may grow into an enlarged needle. This may be the result of aggregation between the particles rather than the attraction of the phosphor nanoparticles with A-901K. However, when the particle size is less than 10 nm, the optical properties may not be improved upon UV irradiation.

The particle size of the phosphor can be manufactured to a size of 300 nm or less through the process of nano-dispersing. Phosphor particles synthesized at high temperature by spray pyrolysis are difficult to coat on a plate-like substrate because they exist in an agglomerated form unless there is a process of nanodispersing. As the coating coverage increases, the fluorescence properties may also be improved, and thus nanodispersing may be performed.

In an embodiment of the present invention, a phosphor prepared by spray pyrolysis may be milled in an aqueous system using a bead mill to disperse nanoparticles. Alternatively, hollow particles may be prepared by adding an organic additive to the precursor solution and then grown into nanocrystals through heat treatment. In the spray pyrolysis method, the degree of nano-ization may vary depending on the organic additive, and even if the same organic additive is used, the degree of nano-ization may vary depending on the composition of the parent body and the dopant.

In the phosphor according to the embodiment of the present invention, in the general formula 1, when A is Ce, B is Gd, and D is Ho and Yb, the ratio of the number of atoms of Ho is d1, and the ratio of the number of atoms of Yb is d2. , 0.005≤b≤0.05, 0.001≤d1≤0.005, and 0.01≤d2≤0.03 may be satisfied.

The phosphor satisfying the above relationship may be one in which Gd is substituted for Ce _{in the CeO 2 crystal lattice.} The a value, which represents the ratio of the number of atoms of Ce, is a value determined from the relationship between the ratio of the number of atoms of other ions and the number of oxidation with O, and the value of f, which represents the ratio of the number of atoms of O, is related to the relationship of the number of oxidation of other ions. Is determined by yourself.

The b value representing the ratio of the number of atoms of Gd to be added may be 0.005 to 0.05. According to the experimental results, when less than 0.005 or more than 0.05, the light emission intensity becomes weaker and the average particle size increases. In consideration of the luminescence characteristics and the particle size of the fluorescent particles, the b value may be 0.005 to 0.05, 0.005 to 0.04, 0.005 to 0.03, 0.005 to 0.02, and 0.005 to 0.01.

When a material made of Ce and O doped with Gd is used as a matrix, the effect is increased in light absorption and luminescence characteristics than when a material made of Ce and O is used as a matrix.

The phosphor according to an embodiment of the present invention may further include C, and C may be an alkali metal and may be at least one of Li, Na, and K. When the C is further included, it is possible to improve light emission characteristics, but it is necessary to select a ratio of the number of atoms within a range that does not impair luminance. Considering this, the c value representing the ratio of the number of atoms of C may be 0 to 0.1, more preferably 0.01 to 0.08, more preferably 0.02 to 0.06, more preferably 0.03 to 0.05, but this is Ce, It may vary depending on the ratio of the ions corresponding to Gd, Ho, and Yb and the number of atoms of each ion.

The ratio of the number of atoms of Ho and Yb is based on the results of preparing a nanophosphor according to an embodiment of the present invention by spray pyrolysis and examining the relative luminance. The phosphor was prepared by spray pyrolysis while changing d1 and d2 values, and then the luminescence intensity was investigated under infrared irradiation at 980 nm, and as a result of the value showing the highest luminance, d1 may be 0.001 to 0.005, more preferably May be 0.002 to 0.004, more preferably 0.003, but this may vary depending on Ce, Gd, and C. In addition, a value showing the highest luminance is a result, and d2 may be 0.01 to 0.03, more preferably 0.02, but this may vary depending on the ratio of the number of atoms of Ce, Gd, and C.

In the phosphor according to an embodiment of the present invention, in the general formula 1, A is Ce, B is Gd, C is Na, and D is Ho and Yb, and the ratio of the number of atoms of Ho is d1 and the ratio of the number of atoms of Yb is In the case of d2, 0.005≦b≦0.03, 0.01≦c≦0.035, 0.001≦d1≦0.005, and 0.01≦d2≦0.03 may be satisfied.

The phosphor satisfying the above relationship may be one in which Gd is substituted for Ce _{in the CeO 2 crystal lattice.} The a value, which represents the ratio of the number of atoms of Ce, is a value determined from the relationship between the ratio of the number of atoms of other ions and the number of oxidation with O, and the value of f, which represents the ratio of the number of atoms of O, is related to the relationship of the number of oxidation of other ions. Is determined by yourself.

The b value representing the ratio of the number of atoms of Gd to be added may be 0.005 to 0.03. According to the experimental results, when less than 0.005 or exceeding 0.03, the light emission intensity becomes weaker and the average particle size increases. In addition, when considering the luminescence characteristics and the particle size of the fluorescent particles, the b value may be 0.005 to 0.02, more preferably 0.005 to 0.01.

When a material made of Ce and O doped with Gd is used as a matrix, the effect is increased in light absorption and luminescence characteristics than when a material made of Ce and O is used as a matrix.

The phosphor according to an embodiment of the present invention may further contain Na. When Na is further included, the luminescence characteristics can be improved, but it is necessary to select a ratio of the number of atoms within a range that does not impair luminance. In consideration of this, the c value representing the ratio of the number of atoms of Na may be 0.01 to 0.035, more preferably 0.02 to 0.03, more preferably 0.03, but this is Ce, Gd, Ho, And the ratio of the ions corresponding to Yb and the number of atoms of each ions.

Phosphors satisfying the above relationship are doped with Ho and Yb. The ratio of the number of atoms of Ho and Yb is based on the results of preparing a nanophosphor according to an embodiment of the present invention by spray pyrolysis and examining the relative luminance. The phosphor was prepared by spray pyrolysis while changing d1 and d2 values, and then the luminescence intensity was investigated under infrared irradiation at 980 nm, and as a result of the value showing the highest luminance, d1 may be 0.001 to 0.005, more preferably May be 0.002 to 0.004, more preferably 0.003, but this may vary depending on Ce, Gd, and C. In addition, a value showing the highest luminance is a result, and d2 may be 0.01 to 0.03, more preferably 0.02, but this may vary depending on the ratio of the number of atoms of Ce, Gd, and C.

In the phosphor according to an embodiment of the present invention, in the general formula 1, A is Ce, B is Gd, C is Li, and D is Ho and Yb, and the ratio of the number of atoms of Ho is d1 and the ratio of the number of atoms of Yb is In the case of d2, 0.005≦b≦0.03, 0.02≦c≦0.1, 0.001≦d1≦0.005, and 0.01≦d2≦0.03 may be satisfied.

The phosphor satisfying the above relationship may be one in which Gd is substituted for Ce _{in the CeO 2 crystal lattice.} The a value, which represents the ratio of the number of atoms of Ce, is a value determined from the relationship between the ratio of the number of atoms of other ions and the number of oxidation with O, and the value of f, which represents the ratio of the number of atoms of O, is related to the relationship of the number of oxidation of other ions. Is determined by yourself.

The b value representing the ratio of the number of atoms of Gd to be added may be 0.005 to 0.03. According to the experimental results, when less than 0.005 or exceeding 0.03, the light emission intensity becomes weaker and the average particle size increases. In addition, when considering the luminescence characteristics and the particle size of the fluorescent particles, the b value may be 0.005 to 0.02, more preferably 0.005 to 0.01.

When a material made of Ce and O doped with Gd is used as a matrix, the effect is increased in light absorption and luminescence characteristics than when a material made of Ce and O is used as a matrix.

The phosphor according to an embodiment of the present invention may further include Li. In the case where Li is further included, it is possible to improve light emission characteristics, but it is necessary to select a ratio of the number of atoms within a range that does not impair luminance. In consideration of this, the c value representing the ratio of the number of atoms of Li may be 0.02 to 0.1, more preferably 0.03 to 0.1, more preferably 0.04 to 0.1, and more preferably 0.05. To 0.1, more preferably 0.05 to 0.08, more preferably 0.05 to 0.06, more preferably 0.05, but this is each corresponding to Ce, Gd, Ho, and Yb It may vary depending on the ratio of the number of atoms of ions.

Phosphors satisfying the above relationship according to an embodiment of the present invention are doped with Ho and Yb. The ratio of the number of atoms of Ho and Yb is based on the results of preparing a nanophosphor according to an embodiment of the present invention by spray pyrolysis and examining the relative luminance. The phosphor was prepared by spray pyrolysis while changing d1 and d2 values, and then the luminescence intensity was investigated under infrared irradiation at 980 nm, and as a result of the value showing the highest luminance, d1 may be 0.001 to 0.005, more preferably May be 0.002 to 0.004, more preferably 0.003, but this may vary depending on Ce, Gd, and C. In addition, a value showing the highest luminance is a result, and d2 may be 0.01 to 0.03, more preferably 0.02, but this may vary depending on the ratio of the number of atoms of Ce, Gd, and C.

In the phosphor according to an embodiment of the present invention, A may be Ce and B may be Zr in General Formula 1 above. The phosphor satisfying the above relationship may be one in which Zr is substituted for Ce _{in the CeO 2 crystal lattice.} According to the experimental results, it was confirmed that when doped with Zr, the luminous intensity increased, which was advantageous in increasing the luminance. In addition, the b value representing the ratio of the number of atoms of Zr may be 0.005 to 0.3. If it is less than 0.005 or exceeds 0.3, the light emission intensity may be weaker. As an example, the b value may be 0.01 to 0.25, or 0.05 to 0.2, or 0.08 to 0.15.

In the phosphor according to an embodiment of the present invention, in the general formula 1, when A is Gd, B is Ce, D is Ho and Yb, the ratio of the number of atoms of Ho is d1, and the ratio of the number of atoms of Yb is d2, The 0.005≦b≦0.3, 0.002≦d1≦0.006, and 0.04≦d2≦0.08 may be satisfied.

The phosphor satisfying the above relationship may be one in which Ce is substituted for Gd _{in the Gd 2} O _{3 crystal lattice.} The value a, which represents the ratio of the number of atoms of Gd, is a value determined from the relationship between the ratio of the number of atoms of other ions and the number of oxidation with O, and the value of f, which represents the ratio of the number of atoms of O, is related to the relationship with the number of oxidation of other ions. Is determined by yourself.

The b value representing the ratio of the number of atoms of Ce to be added may be 0.005 to 0.3. According to the experimental results, when less than 0.005 or exceeding 0.3, the light emission intensity becomes weaker and the average particle size increases. In addition, when considering the luminescence characteristics and the particle size of the fluorescent particles, the b value may be 0.005 to 0.2, and may be 0.005 to 0.1.

When a material made of Gd and O doped with Ce is used as a matrix, the effect is increased in light absorption and luminescence characteristics than when a material made of Gd and O is used as a matrix.

The phosphor according to an embodiment of the present invention may further include C, and C may be an alkali metal and may be at least one of Li, Na, and K. When the C is further included, it is possible to improve light emission characteristics, but it is necessary to select a ratio of the number of atoms within a range that does not impair luminance. Considering this, the c value representing the ratio of the number of atoms of C may be 0 to 0.1, or 0.01 to 0.08, or 0.02 to 0.06, or 0.03 to 0.05, but this is Ce, Gd, Ho, and Yb It may vary depending on the ratio of the ions corresponding to and the number of atoms of each ion.

The ratio of the number of atoms of Ho and Yb is based on the results of preparing a nanophosphor according to an embodiment of the present invention by spray pyrolysis and examining the relative luminance. The phosphor was prepared by spray pyrolysis while changing d1 and d2 values, and then the luminescence intensity was investigated under infrared irradiation at 980 nm, and as a result of the value showing the highest luminance, d1 may be 0.002 to 0.006, more preferably May be 0.003 to 0.005, more preferably 0.004, but this may vary depending on the ratio of the number of atoms of Ce, Gd, and C. In addition, the value showing the highest luminance is the result, and d2 may be 0.04 to 0.08, may be 0.05 to 0.07, and more preferably 0.06, but this is depending on the ratio of the number of atoms of Ce, Gd, and C. It can be different.

The phosphor according to the embodiment of the present invention may emit light at a wavelength of 510 to 580 nm, more preferably 520 to 560 nm, and more preferably 530 to 550 nm when irradiated with infrared rays having a wavelength of 980 nm.

A pearlescent pigment according to an embodiment of the present invention is a base material; And a phosphor according to the present invention coated on the substrate.

Pearlescent pigments may take on double or multiple colors depending on the angle of observation due to the difference in angles that occur when light passes through the pigment layer and some are reflected and the other is refracted.

The pearlescent pigment according to the embodiment of the present invention is coated with a phosphor according to the embodiment of the present invention that emits light in a specific area when irradiated with light of a specific wavelength. It can be used as a security pigment for cards, driver's licenses, check cards, stamps, tickets, credit cards, gift certificates, and the like. In addition, it can be used for security products such as paints, coatings, powder coatings, printing inks, coating compositions, plastics, adhesives, paper stock, building materials or rubber compositions.

The substrate is a pigment having a special optical effect that gives a pearlescent gloss to the object to be colored, and may be coated with a metal oxide on a flake substrate. The flake substrate is not particularly limited, but a substrate including at least one of synthetic mica, natural mica, glass flake, plate-shaped iron oxide, plate-shaped alumina, aluminum flake, plate-shaped silica, talc, and bismuth may be used.

For example, a substrate in which the synthetic mica particles are uniformly dispersed by adding a surfactant to the synthetic mica pulverized into fine powder using a water mixer can be used.In the case of using such a substrate, the coating layer containing the metal oxide is the table of the substrate. It is uniformly adsorbed on the surface and can exhibit excellent gloss and saturation.

It is preferable to use the flake substrate having a particle size of 5 to 250 μm in a plate shape. If the particle size is less than 5㎛, the material is coated on the surface of the substrate, and as the coating thickness increases, the plate-like substrate gradually changes into a spherical shape. That is, the aspect ratio decreases, which causes scattering of light by causing diffuse reflection, so that the same color having the same refractive index cannot be displayed. On the contrary, when the particle diameter exceeds 250 μm, the surface area to be coated increases, making it difficult to construct a coating layer for color realization.

The metal of the metal oxide is silicon (Si), titanium (Ti), zirconium (Zr), antimony (Sb), zinc (Zn), tin (Sn), iron (Fe), magnesium (Mg), manganese (Mn). ), aluminum (Al), cobalt (Co), and barium (Ba) may be any one or more selected from the group consisting of.

Specific examples include titanium dioxide (TiO ₂ ), iron oxide (Fe ₂ O ₃ ), tin dioxide (SnO ₂ ), zirconium dioxide (ZrO ₂ ), silicon dioxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), oxidation Magnesium (MgO), manganese dioxide (MnO ₂ ), and the like.

Most preferably, it may be Adamas A-901K as the substrate. This is alumina (Al ₂ O ₃ ) coated with titanium oxide (TiO ₂ ), and has the best pearl properties, color purity, and luminescence properties.

Pearlescent pigment according to an embodiment of the present invention is prepared by dipping the phosphor in a binder solution using a plate-like substrate coated with _{titanium oxide (TiO 2} ) having a high refractive index on alumina (Al ₂ O _{3 ).} It can be done, and there is no particular limitation on its manufacturing method.

In the pearlescent pigment according to an embodiment of the present invention, the coating thickness of the phosphor of claim 1 coated on the substrate is 10 to 500 nm, more preferably 10 to 400 nm, more preferably 10 to 300 nm, more preferably 10 To 200nm, more preferably 10 to 100nm. According to the experimental results, when coated with the coating thickness, pearl characteristics and fluorescence characteristics were increased.

<Comparative Example 1 and Example 1> Preparation of inorganic phosphor

Comparative Example _{1-1: (. Ce0.977, Ho 0} .003, Yb 0 02) O 2

Comparative Example _{1-2: (. Gd 1 .936,} Ho 0 .004, Yb 0 06) O 3

Example _{1-1: (. Ce 0 02 .977} -b, Gd b, Ho 0 .003, Yb 0) O 2

Example _{1-2: (. Ce 0 .977-} bc, Gd b, Na c, Ho 0 .003, Yb 0 02) O 2

Example _{1-3: (. Ce 0 .977-} bc, Gd b, Li c, Ho 0 .003, Yb 0 02) O 2

Example _{1-4: (. Ce 0 .977-} b, Zr b, Ho 0 .003, Yb 0 02) O 2

Example _{1-5: (. Gd 1 06 .936} -b, Ce b, Ho 0 .004, Yb 0) O 3

The phosphors of the Comparative Examples and Examples were prepared as follows using the spray pyrolysis method.

Ce(NO ₃ ) ₃ ˙6H ₂ 0 is used as a Ce precursor, Zr(NO ₃ ) ₂ ˙xH ₂ O (Zirconiumoxynitratehydrate) is used as a Zr precursor, and Gd ₂ O ₃ (Gadoliniumoxide) or Gd(NO ₃ ) 6H ₂ O was used as the Gd precursor. _{Ho 2} O ₃ and Yb ₂ O ₃ were used as precursors for active ions (Ho ³⁺ ) and activating ions (Yb ^3+). Na ⁺ precursor was used NaHCO ₃ or Na ₂ CO ₃ . The precursor of Li ⁺ was used as _{Li 2} CO _3. Ethylene glycol (EG) was used as an organic additive.

The precursor solution was prepared as follows. First, the oxide precursor is dissolved using nitric acid to form an aqueous solution. After dissolving the remaining aqueous precursors and organic additives to this solution, distilled water was added to make the total amount of the solution 500 mL. At this time, the total concentration of the precursors of the components constituting the phosphor was made to be 0.3 M. The amount of each component constituting the phosphor was adjusted according to the molar ratio of each component required by the stoichiometric equations of the Comparative Examples and Examples. The amount of the organic additive was adjusted to be 80% to 120% of the total molar concentration of the phosphor precursor.

The prepared precursor solution is made into droplets using a droplet generator, and then transferred to a quartz reactor maintained at 900°C using air as a carrier gas, and dried/pyrolyzed. The dried/pyrrolyzed ceramic powder was recovered with a Teflon collector mounted at the end of the quartz reactor. The recovered powder was heat-treated for 3 hours in an oxidizing atmosphere at 1000 ~ 1200°C.

<Experimental Example 1> Measurement of light emission intensity

The thus prepared Comparative Example 1-1 and Examples 1-1 to 1-4 were irradiated with 980 nm IR to compare the light emission intensities between 500 and 600 nm, and are shown in Table 1. When the emission intensity of Comparative Example 1-1 is 1, the emission intensity of Examples 1-1 to 1-4 is shown.

Comparative Example 1-1 Example 1-1
(b=0.01) Example
1-2
(b=0.01, c=0.03) Example
1-3
(b=0.01,
C=0.05) Example
1-4
(b=0.1) Luminous intensity (ratio) One 1.2 2.2 2.5 1.9

According to the above experimental results, it was confirmed that the addition doping of Gd exhibited better luminescence characteristics than the case of using Ce and O as a parent body.

<Experimental Example 2>

Experimental Example 2-1:

In the phosphor prepared in Example 1-1, a nanophosphor was prepared by spray pyrolysis while changing the b value to 0.01, 0.03, 0.05, and 0.1.

As a result of the experiment, a photograph of light emission under the light emission spectrum and infrared radiation is shown in FIG. 1. According to the above results, the most preferable b value was 0.01.

Experimental Example 2-2:

When the b value was fixed to 0.01 in the phosphor prepared in Example 1-2, it was confirmed whether the brightness was improved by additionally doping Na to the Ce site. When Na was doped, it was confirmed that the luminance was improved than when Na was not doped. In addition, the emission spectrum as a result of the experiment while changing the c value to 0.01 to 0.05 is shown in FIG. 2. According to the above results, the most preferable c value was 0.03.

Experimental Example 2-3:

When the b value was fixed to 0.01 in the phosphor prepared in Example 1-3, it was confirmed whether the brightness was improved by additionally doping Li to the Ce site. In the case of doping with Li, it can be seen that the luminance is improved compared to the case in which Li is not doped. In addition, the emission spectrum as a result of the experiment while changing the c value to 0.01 to 0.05 is shown in FIG. 3. According to the above results, the most preferable c value was 0.05.

Experimental Example 2-4:

As an experiment result in the case where the phosphor prepared in Example 1-4 was doped with Zr, a light emission spectrum and a photograph of light emission under infrared irradiation are shown in FIG. 4. In the case of doping with Zr, it was confirmed that the light emission intensity was increased, which is advantageous for increasing the luminance.

Experimental Example 2-5:

In the phosphor prepared in Example 1-5, a nanophosphor was prepared by spray pyrolysis while changing the b value to 0.1, 0.3, and 0.5. As a result of the experiment, a light emission spectrum and a photograph of light emission under infrared radiation are shown in FIG. 5. According to the above results, the most preferable b value was 0.1.

<Example 2> Preparation of pearlescent pigment

In order to coat the phosphor prepared in Example 1 on Adamas A-901K, which is a pearlescent pigment, a solution having a concentration of 10 wt% Adamas A-901K/MeOH was prepared.

Next, resin (HPD96), dispersant (BYK-181), and antifoaming agent (SN-defoamer 399) were mixed at 98:1:1, and then suspended at 1:1 with primary distilled water. A binder solution containing the inorganic phosphor particles prepared in was prepared.

_{Next, 400 g of zirconium oxide (ZrO 2} ) balls were added to a 250 ml polyethylene bottle for ball milling, and then 100 g of a binder solution containing the inorganic phosphor particles prepared in each of Example 1 was added, and then at 35 Hz in the milling equipment. Milling was carried out.

Next, the solution was titrated to a solution having a concentration of 10 wt% Adamas A-901K/MeOH. After the completion of the titration, stirring was performed for 30 minutes to stabilize, and the pH was gradually adjusted to 7.1 using a diluted HCl solution to terminate the coating reaction.

Next, after drying at 100° C. through a dehydration process, agglomerated particles were removed by a screen process to obtain pearlescent pigment powder coated with the inorganic phosphor.

Claims (13)

Including a substance represented by the following general formula 1,
Phosphor
[General Formula 1](A _a , B _b , C _c , D _d ) O _f
(A is Ce or Gd,
When A is Ce, B is at least one of Gd, Zr, Ti, and La,
When A is Gd, B is Ce,
C is any one of alkali metals,
D is at least any one of Ho, Yb, Er, and Tm,
1≤a+b+c+d≤2, 0<a<2, 0.005≤b≤0.3, 0≤c≤0.1, 0<d≤0.1, 2≤f≤3).
The method of claim 1,
In the general formula 1, A is Ce, B is Gd, and D is Ho and Yb,
When the ratio of the number of atoms of Ho is d1 and the ratio of the number of atoms of Yb is d2,
0.005≤b≤0.05, 0.001≤d1≤0.005, and 0.01≤d2≤0.03,
Phosphor.
The method of claim 1,
In the general formula 1, A is Gd, B is Ce, D is Ho and Yb,
When the ratio of the number of atoms of Ho is d1 and the ratio of the number of atoms of Yb is d2,
Satisfying the 0.005≤b≤0.3, 0.002≤d1≤0.006, and 0.04≤d2≤0.08,
Phosphor.
The method of claim 1,
In the general formula 1, A is Ce, B is Gd, C is Li, and D is Ho and Yb,
When the ratio of the number of atoms of Ho is d1 and the ratio of the number of atoms of Yb is d2,
0.005≤b≤0.03, 0.02≤c≤0.1, 0.001≤d1≤0.005, and 0.01≤d2≤0.03,
Phosphor.
The method of claim 1,
In the general formula 1, A is Ce, B is Gd, C is Na, and D is Ho and Yb,
When the ratio of the number of atoms of Ho is d1 and the ratio of the number of atoms of Yb is d2,
0.005≤b≤0.03, 0.01≤c≤0.035, 0.001≤d1≤0.005, and 0.01≤d2≤0.03,
Phosphor.
The method of claim 1,
In the general formula 1, A is Ce, B is Zr,
Phosphor.
The method of claim 1,
The phosphor emits light at a wavelength of 510 to 580 nm when irradiated with infrared rays having a wavelength of 980 nm,
Phosphor
The method of claim 1,
The phosphor has an average particle size D50 of 300 nm or less of the particles,
Phosphor.
materials; And
Including; the phosphor of claim 1 coated on the substrate
Pearl glossy pigment.
The method of claim 9,
The substrate is coated with a metal oxide on the flake substrate,
The flake substrate includes at least one or more of synthetic mica, natural mica, glass flake, plate-shaped iron oxide, plate-shaped alumina, aluminum flake, plate-shaped silica, talc, and bismuth,
The metal of the metal oxide is silicon (Si), titanium (Ti), zirconium (Zr), antimony (Sb), zinc (Zn), tin (Sn), iron (Fe), magnesium (Mg), manganese (Mn). ), including at least one or more of aluminum (Al), cobalt (Co) and barium (Ba),
Pearl glossy pigment.
The method of claim 9,
The substrate is alumina (Al ₂ O ₃ ) coated with titanium oxide (TiO _{2 ),}
Pearl glossy pigment.
The method of claim 9,
The coating thickness of the phosphor of claim 1 coated on the substrate is 10 to 500 nm,
Pearl glossy pigment.
The method of claim 9,
The pearlescent pigment emits light at a wavelength of 510 to 580 nm when irradiated with infrared rays of a wavelength of 980 nm,
Pearl Glossy Pigment

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