Crystal body, phosphor, fluorescent material, and resin sheet

Abstract

The present invention relates to a crystal body characterized by having an oxide matrix comprising SrCa2Ga2O6 or BaSr2Ca6Ga6O18, and a method for manufacturing the same. According to the present invention, it is possible to provide a crystal which is composed of components that are relatively inexpensive and can be stably obtained, and which can be used as a phosphor having excellent characteristics.

Description

Technical Field

[0001] This invention relates to crystals, phosphors, fluorescent materials, and resin sheets. Background Technology

[0002] White LEDs typically have a yellow phosphor (or a green phosphor and a red phosphor) on a blue LED chip. When excited by the light from the blue LED (around λ = 460 nm), the yellow light is emitted. By combining the yellow light with the blue light from the blue LED itself, white light is obtained through color mixing (for example, see Patent Document 1).

[0003] In particular, in backlights and other applications of liquid crystal displays that require the inclusion of the three primary colors of light, it is necessary to display phosphors that emit narrow bands of green light and narrow bands of red light.

[0004] Most phosphors currently used are based on oxides, nitrides, and fluorides, and are manufactured by doping them with rare earth ions and transition metal ions as luminescent ions.

[0005] Therefore, it leads to an increase in the cost of phosphors, and is not the preferred option from the perspective of reducing the use of rare metals.

[0006] In recent years, in particular, there has been increased interest in infrared luminescent materials that absorb ultraviolet light into the visible light region and emit light in the infrared region. For example, applications in devices such as the following are being considered.

[0007] Firstly, despite years of repeated improvements to silicon solar cells, it still takes many years to increase efficiency by even a mere 0.1%. To address this issue, wavelength conversion film technology for solar cells has attracted attention. This technology can easily improve solar cell efficiency by converting ultraviolet to blue light, which solar cells cannot absorb, to wavelengths that solar cells can absorb. In particular, there is a strong demand for materials that can efficiently convert to the infrared region.

[0008] In addition, organic high-conversion-efficiency materials have been used in technologies that incorporate wavelength-converting materials into polymer sheets for agricultural greenhouses and tunnels to promote plant growth. However, their application is limited due to their low weather resistance and short Stokes shift, resulting in significant absorption of light in the visible light region. On the other hand, infrared-emitting inorganic wavelength-converting materials have a greater advantage in stability compared to organic materials, but high-efficiency materials have not yet been discovered.

[0009] In the field of safety technology, safety inks that emit visible light when exposed to ultraviolet light have been used in the past, but future technologies require even higher safety performance. Safety inks that absorb visible light and convert it into near-infrared light have properties that are invisible to the naked eye, and are therefore considered to have higher safety performance than previous products. There is anticipation for the development of even more efficient materials.

[0010] In addition, there is a growing interest in high-efficiency infrared emitting materials, with applications expected in medical technologies such as skin condition improvement, displays, and various LEDs.

[0011] To date, rare earth elements (Pr) have been used as near-infrared luminescence centers in phosphor materials. 3+ 、Nd 3+ Tm 3+ Eu 2+ (etc.) or transition metal elements (Cr) 3+ Ni 2+ V 2+ Mn 4+ Reports (Non-Patent Literature 1 and Non-Patent Literature 2), etc.

[0012] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2007-326981.

[0013] Non-patent literature Non-patent literature 1: FAKroger, Some Aspects of the Luminescence of Solids. (1948) Non-patent literature 2: Toda K., Sato M., Chem Lett. 2014; 43(8). Summary of the Invention

[0014] The problem that the invention aims to solve In order to make crystals widely used in various applications, including phosphor applications, there is a need to develop crystals with novel structures that are composed of relatively inexpensive and stably available components and exhibit new properties.

[0015] In addition, in phosphor applications, there is a requirement for crystals that are composed of relatively inexpensive and stably available components and that emit light efficiently in the visible to infrared region.

[0016] Therefore, the object of the present invention is to solve at least one of the following problems.

[0017] The purpose of this invention is to provide a crystal composed of relatively inexpensive and stably obtainable components, having a novel structure.

[0018] The object of the present invention is to provide a crystal composed of relatively inexpensive and stably obtainable components, which can be used as a phosphor with excellent properties.

[0019] means for solving problems This objective is achieved through the invention described below.

[0020] The crystals of the present invention are characterized by having an oxide matrix composed of SrCa2Ga2O6.

[0021] The crystals of the present invention only need to have an oxide matrix composed of SrCa2Ga2O6, and may also contain elements different from those constituting the oxide matrix. By adjusting the type and content of such elements, the characteristics of the crystals can be appropriately adjusted.

[0022] As described above, the crystals of the present invention may also contain elements other than those constituting the oxide matrix (i.e., Sr, Ca, Ga and O) (hereinafter also referred to as "other elements").

[0023] For example, for at least one of the Sr site, Ca site, and Ga site constituting the oxide matrix, at least a portion of the atom constituting that site may also be replaced by other elements.

[0024] The content of other elements in the crystals of the present invention is preferably 5% by mass or less, more preferably 0.01% by mass or more and 4% by mass or less, and even more preferably 0.1% by mass or more and 3% by mass or less.

[0025] It is particularly preferable that a portion of Ga constituting the oxide matrix is ​​replaced by other elements. This allows for the more suitable obtaining of a crystalline structure having the crystal structure of the oxide matrix.

[0026] Other elements may include, for example, Mn, Cr, Fe, Bi, Ti, V, and rare earth elements (Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu), and may be selected from one or more of these, preferably from the group consisting of Mn, Cr, Bi, and rare earth elements, more preferably from the group consisting of Mn and Cr, and even more preferably Mn. Thus, a crystal that emits light upon excitation by near-ultraviolet to blue light is obtained.

[0027] In the crystals of the present invention, preferably a portion of Ga constituting the oxide matrix is ​​replaced by other elements.

[0028] In the crystals of the present invention, the other elements are preferably one or more selected from the group consisting of Mn, Cr, Fe, Ti, Bi and rare earth elements.

[0029] In the crystals of the present invention, it is preferable that the substitution ratio of Ga to the other elements is 0.10 or less in molar ratio.

[0030] The crystals of the present invention are preferably those shown in the following formula (1).

[0031] SrCa2(Ga （1-x） M x )2O6 (1) (In equation (1), M is one or more elements selected from the group consisting of Mn, Cr, Fe, Ti, Bi and rare earth elements, satisfying the relationship 0 < x ≤ 0.10.) Furthermore, the crystals of the present invention are characterized by having a composition of BaSr2Ca6Ga6O 18 The oxide parent body is formed.

[0032] In the crystals of the present invention, preferably a portion of Ga constituting the oxide matrix is ​​replaced by other elements.

[0033] In the crystals of the present invention, the other elements that replace Ga are preferably one or more selected from the group consisting of Mn, Cr, Fe, Ti, Bi and rare earth elements.

[0034] In the crystals of the present invention, it is preferable that the substitution ratio of Ga to the other elements is 0.10 or less in molar ratio.

[0035] The crystals of the present invention are preferably those shown in the following formula (2).

[0036] BaSr2Ca6 (Ga （1-x） M x 6O 18 (2) (In equation (2), M is one or more elements selected from the group consisting of Mn, Cr, Fe, Ti, Bi and rare earth elements, satisfying the relationship 0 < x ≤ 0.10.) The phosphor of the present invention is characterized in that it is composed of the crystal of the present invention described above.

[0037] The fluorescent material of the present invention is characterized in that it is formed by coating the surface of the phosphor of the present invention with a light-transmitting resin.

[0038] The resin sheet of the present invention is characterized in that it is formed from a light-transmitting resin substrate and contains the phosphor of the present invention described above.

[0039] Invention Effects According to the present invention, a crystal composed of relatively inexpensive and stably obtainable components and having a novel structure can be provided.

[0040] According to the present invention, a crystal composed of relatively inexpensive and stably obtainable components can be provided, which can be used as a phosphor with excellent properties. Attached Figure Description

[0041] Figure 1 This is a flowchart illustrating an example of a process in the method for manufacturing crystals according to the present invention.

[0042] Figure 2 This is a diagram showing the X-ray diffraction pattern of the crystal in Example 1.

[0043] Figure 3 These are diagrams showing the powder X-ray diffraction patterns of the crystals in Examples 2-10.

[0044] Figure 4 This is a graph showing the results of the photoluminescence measurement of the crystals in Example 1.

[0045] Figure 5 This is a graph showing the results of the photoluminescence measurement of the crystals in Example 1.

[0046] Figure 6 This is a graph showing the relationship between the luminescence intensity when the crystals of Examples 2-9 are irradiated with ultraviolet light of a predetermined intensity (365nm).

[0047] Figure 7 The image shows photographs of the crystal of Example 1 when irradiated with an indoor lamp, when irradiated with ultraviolet light with a wavelength of 254 nm, and when irradiated with ultraviolet light with a wavelength of 365 nm.

[0048] Figure 8 This is a diagram showing the powder X-ray diffraction pattern of the crystal in Example 11.

[0049] Figure 9 This is a graph showing the measurement results of photoluminescence of the crystal in Example 11.

[0050] Figure 10 This refers to the second aspect of the present invention involving a material composed of BaSr2Ca6Ga6O 18 A schematic diagram of the crystal structure of the oxide parent body.

[0051] Figure 11 These are diagrams showing the powder X-ray diffraction patterns of the crystals in Examples 12-18.

[0052] Figure 12 This is a graph showing the measurement results of photoluminescence when the crystals of Examples 12-18 are excited at around 330 nm.

[0053] Figure 13 This is a graph showing the measurement results of photoluminescence when the crystals of Examples 12-18 are excited at around 460 nm. Detailed Implementation

[0054] The preferred embodiments of the present invention will now be described in detail.

[0055] <Crystal of the first aspect of the present invention> (1) Crystalline First, the crystals of the present invention will be described.

[0056] Furthermore, in the following description, the case of the crystal of the present invention being used as an optical material, especially a phosphor, is taken as the main focus, but it is not limited thereto. As described below, the crystal of the present invention can be used in a wide range of applications as various optical materials other than phosphors, and as materials other than optical materials.

[0057] The crystals of the present invention are characterized by having an oxide matrix composed of SrCa2Ga2O6.

[0058] This configuration provides a crystalline structure composed of relatively inexpensive and stably obtainable components, capable of being used as a phosphor with excellent properties. In particular, the novel crystal structure, different from conventional crystals, enables fluorescence properties not achievable in compounds with known crystal structures. For example, compared to compounds with conventional crystal structures, it allows for higher wavelength red emission (emission at wavelengths longer than 670 nm) and emission in a narrower frequency band. Therefore, the crystal of this invention can be appropriately applied to applications such as phosphors for white LEDs, ultraviolet absorbers, phosphors for wavelength conversion films in silicon solar cells, wavelength conversion materials for agricultural sheets for plant growth control, security applications, and biosensors. Furthermore, as detailed later, the crystal of this invention only needs to have an oxide matrix composed of SrCa2Ga2O6, but it may also contain elements different from those constituting the oxide matrix. The properties of the crystal can be appropriately adjusted by the type and content of such elements.

[0059] As described above, the crystals of the present invention may also contain elements other than those constituting the oxide matrix (i.e., Sr, Ca, Ga and O) (hereinafter also referred to as "other elements").

[0060] For example, for at least one of the Sr site, Ca site, and Ga site constituting the oxide matrix, at least a portion of the atom constituting that site may also be replaced by other elements.

[0061] The content of other elements in the crystals of the present invention is preferably 5% by mass or less, more preferably 0.01% by mass or more and 4% by mass or less, and even more preferably 0.1% by mass or more and 3% by mass or less.

[0062] It is particularly preferable that a portion of Ga constituting the oxide matrix is ​​replaced by other elements. This allows for the more suitable obtaining of a crystalline structure having the crystal structure of the oxide matrix.

[0063] Other elements may include, for example, Mn, Cr, Bi, Fe, Ti, V, and rare earth elements (Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu), and may be selected from one or more of these, preferably from the group consisting of Mn, Cr, Bi, and rare earth elements, more preferably from the group consisting of Mn and Cr, and even more preferably Mn. Thus, a crystal that emits light upon excitation by near-ultraviolet to blue light is obtained.

[0064] In the crystals of the present invention, tetravalent (Mn) is preferred. 4+ The state contains Mn.

[0065] Thus, by irradiating with near-ultraviolet to blue light, a crystal exhibiting red luminescence with a peak at 712 nm was obtained.

[0066] The substitution ratio of Ga by the other elements is preferably 0.10 or less in molar ratio, more preferably 0.002 or more and 0.08 or less, and even more preferably 0.01 or more and 0.07 or less.

[0067] As a result, crystals can exhibit superior fluorescence properties (especially luminescence intensity).

[0068] In particular, the crystals of the present invention are preferably those shown in the following formula (1).

[0069] SrCa2(Ga （1-x） M x )2O6 (1) (In equation (1), M is one or more elements selected from the group consisting of Mn, Cr, Fe, Ti, Bi, V and rare earth elements, satisfying the relationship 0 < x ≤ 0.10.) As a result, the crystals can exhibit particularly excellent fluorescent properties (especially luminescence intensity).

[0070] In the above formula (1), x can satisfy the relationship 0 < x ≤ 0.10, preferably 0.001 ≤ x ≤ 0.09, more preferably 0.002 ≤ x ≤ 0.08, and even more preferably 0.01 ≤ x ≤ 0.07.

[0071] This will allow the aforementioned effects to be achieved more significantly.

[0072] In addition, M in the above formula (1) can be selected from one or more of the group consisting of Mn, Cr, Fe, Ti, Bi, V and rare earth elements, preferably one or more of the group consisting of Mn and Cr, and more preferably Mn.

[0073] This will allow the aforementioned effects to be achieved more significantly.

[0074] The crystals of the present invention need only have a crystalline structure in at least a portion thereof, and may also include amorphous portions.

[0075] The proportion of the portion having a crystalline structure in the crystal of the present invention is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more.

[0076] Furthermore, the ratio of the crystalline structure portion to the amorphous structure portion in the crystal of the present invention can be determined by X-ray diffraction.

[0077] The crystals of the present invention can be crystals for any purpose. Examples of uses for the crystals of the present invention include ultraviolet absorbers, optical sensors, wavelength conversion materials, phosphors, and other optical materials.

[0078] In particular, the crystals of the present invention are composed of relatively inexpensive and stably obtainable components, and exhibit the excellent optical properties described above, and are therefore preferably used in phosphors.

[0079] Furthermore, the crystals of the present invention, when excited by short-wavelength near-ultraviolet to blue light, can emit long-wavelength red to near-infrared light, and therefore can be appropriately applied, for example, to wavelength conversion materials for wavelength conversion films in solar cells such as silicon.

[0080] As a phosphor, it can be used, for example, as a light-emitting element for display, a light-emitting element for lighting, a scintillator, etc.

[0081] As a UV absorber, it can be used as a UV-absorbing material in UV-absorbing sheets, foundations, lotions, sunscreens, etc.

[0082] As a light sensor, it can be used, for example, as a light detection element in a photodetector.

[0083] The Ga at the Ga site can be replaced by elements other than Mn without impairing the effects of the present invention. Other elements that can be used as Ga sites include Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Al. In the crystal of the present invention, these other elements are contained in the Ga site in a trivalent form.

[0084] The substitution ratio of elements other than Mn in the Ga site is expressed as the molar percentage of the other elements relative to all elements in the Ga site ((moles of elements other than Mn / moles of all elements in the Ga site) × 100), preferably 20 mol% or less, more preferably 5 mol% or less.

[0085] The Sr at the Sr site can be replaced by other elements without impairing the effects of the present invention. Examples of such other elements include Mg, Zn, Cu, Co, Ni, Fe, Mn, Ce, and Sn. In the crystals of the present invention, these other elements are contained in the Sr site in a divalent form.

[0086] The substitution ratio of other elements in the Sr site is expressed as the molar percentage of other elements relative to all elements in the Sr site ((moles of other elements / moles of all elements in the Sr site) × 100), preferably 20 mol% or less, more preferably 5 mol% or less.

[0087] The Ca at the Ca site can be replaced by other elements without impairing the effects of the invention. Examples of such other elements include Mg, Zn, Cu, Co, Ni, Fe, Mn, Ce, and Sn. In the crystals of the present invention, these other elements are contained in the Ca site in a divalent form.

[0088] The substitution ratio of other elements in the Ca site is expressed as the molar percentage of other elements relative to all elements in the Ca site ((moles of other elements / moles of all elements in the Ca site) × 100), preferably 20 mol% or less, more preferably 5 mol% or less.

[0089] In the crystal of the present invention, the preferred molar ratio of each site in the overall crystal is "all Sr site elements : all Ca site elements : all Ga site elements : all O site elements = 1.00 : 2.00 : 2.00 : 6.00". However, without impairing the effect of the present invention, the ratio of more than one site may deviate from the above range. Preferably, it is "all Sr site elements : all Ca site elements : all Ga site elements : all O site elements = 1.00 ± 0.05 : 2.00 ± 0.10 : 2.00 ± 0.10 : 6.00 ± 0.30".

[0090] <Crystal of the second aspect of the present invention> (1) Crystalline In the following description, the crystal of the present invention is described primarily as an optical material, especially a phosphor, but it is not limited thereto. As described below, the crystal of the present invention can be used in a wide range of applications as various optical materials other than phosphors, and as materials other than optical materials.

[0091] The crystals of the present invention are characterized by having a composition of BaSr2Ca6Ga6O 18 The constituent oxide matrix. That is, the crystal of the present invention is characterized by having BaSr2Ca6Ga6O 18 The crystal structure has at least an oxide matrix composed of Ba, Sr, Ca and Ga.

[0092] use Figure 10 For those with BaSr2Ca6Ga6O 18 The crystalline form of the oxide parent body is explained. Figure 10 This indicates that it has the properties of BaSr2Ca6Ga6O 18 A schematic diagram of the crystal structure of the oxide parent body. Figure 10 In the middle, crystal (1) has a crystal structure of BaSr2Ca6Ga6O 18 The crystal structure is a crystal structure in which constituent elements are arranged at Ba, Sr, Ca, and Ga sites. Furthermore, in Figure 10 The crystal (1) is composed of Ba (2) at Ba sites, Sr (3) at Sr sites, Ca (4) at Ca sites, Ga (5) at Ga sites, and O (6). In crystal (1), BaSr2Ca6Ga6O 18 In the crystal structure, a portion of the Ga sites are replaced by Mn.

[0093] In this invention, it has a composition of BaSr2Ca6Ga6O 18 The constituent oxide parent refers to the oxide that has properties similar to BaSr2Ca6Ga6O. 18 The parent crystal with the same structure, where some of the Ba, Sr, Ca, or Ga sites are replaced by other elements, is BaSr2Ca6Ga6O. 18 That is, in this invention, it has a composition of BaSr2Ca6Ga6O 18 The crystalline form of the oxide matrix refers to the one that has properties similar to BaSr2Ca6Ga6O. 18 The same crystal structure, and with BaSr2Ca6Ga6O 18 This invention relates to crystals whose parent material, BaSr2Ca6Ga6O, is partially substituted by other elements. The crystals of this invention are those having the composition BaSr2Ca6Ga6O. 18 The constituent oxide matrix can be used, or it can contain elements different from those constituting the constituent oxide matrix. By adjusting the types and amounts of such elements, the characteristics of the crystal can be appropriately adjusted.

[0094] In this invention, BaSr2Ca6Ga6O18 The crystal structure is obtained by replacing one-third of the Sr sites in SrCa2Ga2O6 with Ba. Furthermore, the inventors of this invention discovered that the crystal obtained by replacing one-third of the Sr sites in SrCa2Ga2O6 with Ba, i.e., having a structure of BaSr2Ca6Ga6O... 18 The crystals of the oxide matrix absorb light from the ultraviolet to the visible region and emit light from the visible to the infrared region. They exhibit novel fluorescence properties due to the presence of a SrCa2Ga2O6 oxide matrix as described above (high-wavelength red emission (emission at wavelengths longer than 670 nm, emission in a narrow frequency band), and excellent absorption of blue light in the 450-500 nm region. Therefore, the crystals of the present invention can be appropriately applied, for example, to phosphors for white LEDs, ultraviolet absorbers, phosphors for wavelength conversion films in silicon solar cells, wavelength conversion materials for agricultural sheets for plant growth control, security applications, and biosensors. Furthermore, as detailed later, the crystals of the present invention only require a matrix of BaSr2Ca6Ga6O6. 18 The constituent oxide matrix can be used, or it can contain elements different from those constituting the constituent oxide matrix. By adjusting the types and amounts of such elements, the characteristics of the crystal can be appropriately adjusted.

[0095] As described above, the crystals of the present invention may also contain a composition of BaSr2Ca6Ga6O 18 Elements other than the elements constituting the parent oxide (i.e., Ba, Sr, Ca, Ga, and O) (hereinafter also referred to as "other elements"). That is, for the elements constituting BaSr2Ca6Ga6O 18 At least one of the Ba site, Sr site, Ca site, and Ga site, and at least a portion of the element constituting the site may be replaced by other elements.

[0096] The content of other elements in the crystals of the present invention is preferably 5.0% by mass or less, more preferably 0.01% by mass or more and 4.0% by mass or less, and even more preferably 0.1% by mass or more and 3.0% by mass or less.

[0097] The preferred crystal of the present invention is the following formula (2): BaSr2Ca6 (Ga （1-x） M x 6O 18 (2) (In equation (2), M is one or more elements selected from the group consisting of Mn, Cr, Fe, Ti, Bi, V and rare earth elements, satisfying the relationship 0 < x ≤ 0.10.) x is 0 < x ≤ 0.10, preferably 0.001 ≤ x ≤ 0.09, and more preferably 0.01 ≤ x ≤ 0.07. By making the crystal of the present invention an oxide as shown in formula (2), a crystal that emits light in the visible to infrared region is formed. In particular, having a novel crystal structure different from conventional crystals, fluorescence properties that cannot be obtained in compounds with known crystal structures can be obtained. For example, compared with compounds with conventional crystal structures, red emission at a higher wavelength (emission at a wavelength longer than 670 nm) and emission in a narrower frequency band can be obtained. Furthermore, by making the crystal of the present invention an oxide as shown in formula (2), it is preferable from the perspective of improving the absorption of light at 300 to 600 nm, preferably 300 to 550 nm, and the emission of light at 650 to 900 nm, preferably 650 to 750 nm.

[0098] The preferred crystal of the present invention is an oxide as shown in the following formula (3): (Ba) （1-α） A1 α ) p (Sr) （1-β） A2 β ) q (Ca) （1-γ） A3 γ ) r (Ga) （1-x-δ） M x A4 δ ) s O t (3) (In the formula, A1, A2, and A3 are selected from one or more of the group consisting of Mg, Zn, Cu, Co, Ni, Fe, Mn, Ce, and Sn. A1, A2, and A3 can be the same or different. A4 is selected from one or more of the group consisting of Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Al. M is selected from Mn.) The element is selected from one or more of the following groups: Cr, Fe, Ti, Bi, V, and rare earth elements, where 0.00≤α≤0.20, 0.00≤β≤0.20, 0.00≤γ≤0.20, 0.00≤δ≤0.20, 0<x≤0.10, p=1.00±0.05, q=2.00±0.10, r=6.00±0.30, s=6.00±0.30, and t=18.00±0.90. By making the crystal of the present invention an oxide as shown in formula (3), a crystal that emits light in the visible to infrared region is formed. In particular, having a novel crystal structure different from conventional crystals, fluorescence properties that cannot be obtained in compounds with known crystal structures can be obtained. For example, compared with compounds with conventional crystal structures, red emission at a higher wavelength (emission at a wavelength longer than 670 nm) and emission in a narrower frequency band can be obtained. Furthermore, by making the crystal of the present invention an oxide as shown in formula (3), it is preferable from the perspective of improving the absorption of light at 300-600 nm, preferably 300-550 nm, and the emission of light at 650-900 nm, preferably 650-750 nm, is enhanced.

[0099] α is 0.00≤α≤0.20, preferably 0.00≤α≤0.10, and more preferably 0.00≤α≤0.05.

[0100] β is 0.00≤β≤0.20, preferably 0.00≤β≤0.10, and more preferably 0.00≤β≤0.05.

[0101] γ is 0.00≤γ≤0.20, preferably 0.00≤γ≤0.10, and more preferably 0.00≤γ≤0.05.

[0102] δ is 0.00≤δ≤0.20, preferably 0.00≤δ≤0.10, and more preferably 0.00≤δ≤0.05.

[0103] x is 0 < x ≤ 0.10, preferably 0.001 ≤ x ≤ 0.09, and more preferably 0.01 ≤ x ≤ 0.07.

[0104] p is p = 1.00 ± 0.05, preferably p = 1.00 ± 0.01, and more preferably p = 1.000 ± 0.001.

[0105] q is q = 2.00 ± 0.10, preferably q = 2.00 ± 0.02, and more preferably q = 2.000 ± 0.002.

[0106] r is r = 6.00 ± 0.30, preferably r = 6.00 ± 0.06, and more preferably r = 6.000 ± 0.006.

[0107] The value of s is s = 6.00 ± 0.30, preferably s = 6.00 ± 0.06, and more preferably s = 6.000 ± 0.006.

[0108] The value of t is t = 18.00 ± 0.90, preferably t = 18.00 ± 0.18, and more preferably t = 18.000 ± 0.018.

[0109] It is preferable to improve the absorption of light in the range of 300-600 nm, preferably 300-550 nm, and the emission of light in the range of 650-900 nm, preferably 650-750 nm, by making the values ​​of α, β, γ, δ, x, p, q, r, s and / or t within the range of the above.

[0110] From the viewpoint of enhancing the absorption of light in the 300-350 nm and 450-500 nm ranges, and enhancing the emission of light in the 650-900 nm range, preferably in the 650-750 nm range, the crystal of the present invention is preferably composed of BaSr2Ca6Ga6O. 18 A portion of the Ga that forms the oxide matrix is ​​replaced by other elements.

[0111] Other elements M that can replace Ga at Ga sites include Mn, Cr, Fe, Ti, Bi, V, and rare earth elements. M can be one or more selected from Mn, Cr, Fe, Ti, Bi, V, and rare earth elements, preferably one or more selected from the group consisting of Mn, Cr, and rare earth elements, more preferably one or more selected from the group consisting of Mn and Cr, and even more preferably Mn. M is the element that becomes the luminescent center when used as a phosphor. Therefore, the absorption of light in the 300-600 nm range, preferably 300-550 nm, is strong, and the luminescence of light in the 650-900 nm range, preferably 650-750 nm, is enhanced.

[0112] In the crystals of this invention, Mn can be tetravalent (Mn 4+ The state of ) can also be contained in divalent (Mn) 2+ The state includes, preferably, tetravalent (Mn) 4+ The state includes ). Furthermore, in the crystals of this invention, Cr, Bi, Fe, Ti, V, and rare earth elements are in the trivalent (M) state. 3+ The form of ) is contained in the Ga site.

[0113] The substitution ratio of M in the Ga site, expressed as the mole % of M relative to all elements in the Ga site ((moles of M / moles of all elements in the Ga site) × 100), is greater than 0 mol% and less than 10 mol%, preferably 0.1 to 9 mol%, more preferably 1 to 7 mol%. By keeping the substitution ratio of M in the Ga site within the above range, the absorption of light at 300 to 600 nm, preferably 300 to 550 nm, is strengthened, and the emission of light at 650 to 900 nm, preferably 650 to 750 nm, is strengthened. When there are multiple M, the above moles of M are the total moles of these multiple M.

[0114] The Ga at the Ga site can be replaced by other elements A4 besides M, without impairing the effects of the present invention. Examples of A4 include Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Al. In the crystal of the present invention, the Ga at the Ga site is trivalent (A4). 3+ The form contains A4.

[0115] The substitution ratio of A4 in the Ga site, expressed as the mole percentage of A4 relative to all elements in the Ga site ((moles of A4 / moles of all elements in the Ga site) × 100), is 20 mol% or less, preferably 10 mol% or less, and more preferably 5 mol% or less. When there are multiple A4 groups, the aforementioned mole number of A4 is the total mole number of these multiple A4 groups.

[0116] The Ba at the Ba site can be replaced by other elements Al without impairing the effects of the present invention. Examples of Al include Mg, Zn, Cu, Co, Ni, Fe, Mn, Ce, and Sn. In the crystals of the present invention, Al exists in a divalent state (Al2O3). 2+ The form of ) is contained in the Ba site.

[0117] The substitution ratio of A1 in the Ba site, expressed as the mole percentage of A1 relative to all elements in the Ba site ((moles of A1 / moles of all elements in the Ba site) × 100), is 20 mol% or less, preferably 10 mol% or less, and more preferably 5 mol% or less. When there are multiple A1 groups, the aforementioned mole percentage of A1 refers to the total moles of these multiple A1 groups.

[0118] The Sr at the Sr site can be replaced by other elements A2 without impairing the effects of the present invention. Examples of A2 include Mg, Zn, Cu, Co, Ni, Fe, Mn, Ce, and Sn. In the crystals of the present invention, A2 exists in a divalent state (A2... 2+ The form of ) is contained in the Sr site.

[0119] The substitution ratio of A2 in the Sr site, expressed as the mole percentage of A2 relative to all elements in the Sr site ((moles of A2 / moles of all elements in the Sr site) × 100), is 20 mol% or less, preferably 10 mol% or less, and more preferably 5 mol% or less. When there are multiple A2 groups, the aforementioned mole percentage of A2 is the total mole percentage of these multiple A2 groups.

[0120] The Ca at the Ca site can be replaced by other elements A3 without impairing the effects of the present invention. Examples of A3 include Mg, Zn, Cu, Co, Ni, Fe, Mn, Ce, and Sn. In the crystals of the present invention, A3 exists in a divalent (A2) state.2+ The form of ) is contained in the Ca site.

[0121] The substitution ratio of A3 in the Ca site, expressed as the mole percentage of A3 relative to all elements in the Ca site ((moles of A3 / moles of all elements in the Ca site) × 100), is 20 mol% or less, preferably 10 mol% or less, and more preferably 5 mol% or less. When there are multiple A3s, the aforementioned mole number of A3s is the total mole number of these multiple A3s.

[0122] In the crystal of the present invention, the preferred molar ratio of each site in the overall crystal is "all Ba site elements : all Sr site elements : all Ca site elements : all Ga site elements : all O site elements = 1.00 : 2.00 : 6.00 : 6.00 : 18.00". However, the elements at each site may deviate from the above range without impairing the effect of the present invention. Preferably, it is "all Ba site elements : all Sr site elements : all Ca site elements : all Ga site elements : all O site elements = 1.00 ± 0.05 : 2.00 ± 0.10 : 6.00 ± 0.30 : 6.00 ± 0.30 : 18.00 ± 0.90", more preferably "all Ba site elements : all Sr site elements : all Ca site elements : all Ga site elements : all O site elements = 1.00 ± 0". .01∶2.00±0.02∶6.00±0.06∶6.00±0.06∶18.00±0.18”, more preferably “all Ba site elements∶all Sr site elements∶all Ca site elements∶all Ga site elements∶all O elements of O sites = 1.000±0.001∶2.000±0.002∶6.000±0.006∶6.000±0.006∶18.000±0.018”.

[0123] The crystal structure of the crystal of the present invention is the Turulight structure series, which is a structure with a cubic crystal system space group such as F432.

[0124] The crystal of the present invention, having the above-described structure, exhibits red emission with a peak around 710 nm when irradiated with light of 300-600 nm.

[0125] The crystals of the present invention need only have a crystalline structure in at least a portion thereof, and may also include amorphous portions.

[0126] The proportion of the portion having a crystalline structure in the crystal of the present invention is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more.

[0127] Furthermore, the ratio of the crystalline structure portion to the amorphous structure portion in the crystal of the present invention can be determined by X-ray diffraction.

[0128] The average particle size of the crystals of the present invention is preferably 1 nm to 100 μm, more preferably 10 to 100 μm, and even more preferably 15 to 50 μm. Furthermore, in the present invention, the average particle size is obtained by taking photographs of the particles using a SEM (Scanning Electron Microscope: JSM-7900F, manufactured by Nippon Electron Ltd.) under an accelerating voltage of 8 kV, measuring the minor diameter of arbitrarily selected 100 particles, and calculating their average value. Image analysis is performed using the image analysis and measurement software WinROOF.

[0129] The crystals of the present invention, through the above-described configuration, are composed of relatively inexpensive and stably obtainable components, and therefore have the potential to be applied to various uses. They can provide oxide matrixes with novel structures exhibiting foreseeable new properties, namely oxide matrixes composed of SrCa2Ga2O6 or BaSr2Ca6Ga6O6. 18 The crystals are composed of an oxide matrix. Further, the crystals of the present invention are formed by using an oxide matrix composed of SrCa2Ga2O6 or BaSr2Ca6Ga6O6. 18 By replacing the elements in the oxide matrix with other elements, it is possible to achieve diversified applications and higher performance.

[0130] The crystals of the present invention are composed of relatively inexpensive and stably obtainable components, providing crystals that can be used as phosphors with excellent properties. Furthermore, by substituting elements of the oxide matrix with other elements, the crystals of the present invention can provide crystals that emit light in the visible to infrared region. In particular, the crystals of the present invention have a novel crystal structure different from conventional crystals, enabling the acquisition of fluorescence properties not obtainable in compounds with known crystal structures. For example, compared to compounds with conventional crystal structures, higher wavelength red emission (emission at wavelengths longer than 670 nm) and emission in a narrower frequency band are possible. Therefore, the crystals of the present invention can be appropriately applied to red phosphors for white LEDs, wavelength conversion materials for silicon solar cells, etc.

[0131] The crystal of the present invention can be a crystal for any purpose. Examples of uses for the crystal of the present invention include ultraviolet absorbers, photosensors, wavelength conversion materials, phosphors, and other optical materials. In particular, the crystal of the present invention exhibits excellent performance as a phosphor.

[0132] Furthermore, the crystals of the present invention, when excited by short-wavelength near-ultraviolet to blue light, can emit long-wavelength red to near-infrared light, and therefore can be appropriately applied, for example, to wavelength conversion materials for wavelength conversion films in solar cells such as silicon.

[0133] As a phosphor, it can be used, for example, as a plant growth promoter, a light-emitting element for display, a light-emitting element for lighting, a scintillator, etc.

[0134] As a UV absorber, it can be used as a UV-absorbing material in UV-absorbing sheets, foundations, lotions, sunscreens, etc.

[0135] As a light sensor, it can be used, for example, as a light detection element in a photodetector.

[0136] (2) Methods for manufacturing crystals Next, the manufacturing method of the crystal of the present invention (the crystal of the first aspect of the present invention and the manufacturing method of the second aspect of the present invention) will be described. Furthermore, the manufacturing method of the crystal of the second aspect of the present invention and the crystal of the first aspect of the present invention are identical except for whether or not a Ba source substance is required. Therefore, the differences will be described separately below, and the similarities will be collectively referred to as the manufacturing method of the crystal of the second aspect of the present invention and the manufacturing method of the crystal of the first aspect of the present invention, and will be described as the manufacturing method of the crystal of the present invention.

[0137] Figure 1 This is a flowchart illustrating an example of the steps in the method for manufacturing the crystals of the present invention.

[0138] The crystals of the present invention can be suitably manufactured, for example, by using a method having the following steps: a mixing step, in which a substance of Sr source, a substance of Ca source and a substance of Ga source, which are used as raw materials, are mixed (first method) or at least a substance of Ba source, a substance of Sr source, a substance of Ca source and a substance of Ga source are mixed (second method); and a heat treatment step, in which the mixture obtained by the mixing step is heat-treated.

[0139] Therefore, it is possible to appropriately manufacture crystals composed of relatively inexpensive and stably obtainable components, which can be used as phosphors with excellent properties.

[0140] The following is a description of each process.

[0141] (2-1) Mixing process In the mixing process, in the first method, a substance from an Sr source, a substance from a Ca source, and a substance from a Ga source are mixed; in the second method, at least a substance from a Ba source, a substance from an Sr source, a substance from a Ca source, and a substance from a Ga source are mixed to obtain a raw material mixture.

[0142] In addition, in order to correspond to the composition of the crystal to be manufactured, in the mixing process, in the first mode, raw materials other than Sr source material, Ca source material, and Ga source material (i.e., materials of other element sources) may be used. In the second mode, raw materials other than Ba ​​source material, Sr source material, Ca source material, and Ga source material (i.e., materials of other element sources) may be used.

[0143] Furthermore, there are no particular restrictions on the timing of mixing the components in the mixing process. For example, all the raw materials can be mixed together, or other raw materials can be mixed after mixing a variety of specific raw materials.

[0144] As Sr, Ca, Ga, and Ba sources, any compound containing Sr, Ca, Ga, and Ba can be used, such as their oxides, carbonates, hydroxides, etc. Among these, at least one of metal carbonates and metal oxides is preferred.

[0145] Therefore, the reactions in the subsequent heat treatment processes can be carried out appropriately.

[0146] Hydrates can also be used as these compounds. In the following description of preferred compounds, the hydrate water of the hydrate is omitted.

[0147] Examples of Sr sources include strontium oxide (SrO), strontium carbonate (SrCO3), and strontium hydroxide (Sr(OH)2).

[0148] Examples of sources of Ca include calcium oxide (CaO), calcium carbonate (CaCO3), and calcium hydroxide (Ca(OH)2).

[0149] Examples of Ga sources include gallium oxide (Ga2O3), gallium carbonate (Ga2(CO3)3), and gallium hydroxide (Ga(OH)3).

[0150] Examples of sources of Ba include barium oxide (BaO), barium carbonate (BaCO3), and barium hydroxide (Ba(OH)2).

[0151] Mn sources that can serve as other element sources include, for example, manganese oxides (MnO, Mn3O4, Mn2O3, MnO2, MnO3, Mn2O7), manganese carbonate (MnCO3), and manganese hydroxide (Mn(OH)2).

[0152] Examples of Cr sources that can serve as sources of the other elements include, for example, chromium oxide (CrO, Cr2O3, CrO2, CrO3), chromium carbonate (Cr2(CO3)3), and chromium hydroxide (Cr(OH)2, Cr(OH)3).

[0153] Bi sources that can serve as other element sources include, for example, bismuth oxide (Bi₂O₃), bismuth carbonate (Bi₂(CO₃)₃), bismuth hydroxide (Bi(OH)₃), etc.

[0154] Rare earth element sources, such as oxides, carbonates, hydroxides, etc., of rare earth elements can be used as other element sources.

[0155] More specifically, when the rare earth element is, for example, Sc, the Sc source that serves as the source of the rare earth element can be, for example, scandium oxide (Sc2O3), scandium carbonate (Sc2(CO3)3), scandium hydroxide (Sc(OH)3), etc.

[0156] Furthermore, when the rare earth element is, for example, Pr, a Pr source that serves as the source of the rare earth element can be, for example, praseodymium oxide (Pr6O). 11 Praseodymium carbonate (Pr2(CO3)3, Pr(CO3)2), praseodymium hydroxide (Pr(OH)3, Pr(OH)4), etc.

[0157] In addition, when the rare earth element is, for example, Sm, the Sm source that serves as the source of the rare earth element can be, for example, samarium oxide (Sm2O3), samarium carbonate (SmCO3, Sm2(CO3)3), samarium hydroxide (Sm(OH)2, Sm(OH)3), etc.

[0158] In addition, when the rare earth element is, for example, Eu, Eu sources that serve as the source of the rare earth element can be, for example, europium oxide (Eu2O3), europium carbonate (EuCO3, Eu2(CO3)3), europium hydroxide (Eu(OH)2), etc.

[0159] In addition, when the rare earth element is, for example, Tb, the Tb source that serves as the source of the rare earth element can be, for example, terbium oxide (Tb2O3, Tb4O7), terbium carbonate (Tb2(CO3)3, Tb(CO3)2), terbium hydroxide (Tb(OH)3, Tb(OH)4), etc.

[0160] In addition, when the rare earth element is, for example, Tm, the Tm source that serves as the source of the rare earth element can be, for example, thulium oxide (Tm2O3), thulium carbonate (TmCO3, Tm2(CO3)3), thulium hydroxide (Tm(OH)2, Tm(OH)3), etc.

[0161] In the mixing process, the Sr source, Ca source, Ga source, Ba source (and other element sources as needed) described above are mixed in a predetermined ratio, such as a stoichiometric ratio, to prepare a raw material mixture.

[0162] The mixing method for the raw material mixture can be either dry mixing or wet mixing. From the viewpoint of being able to mix the raw materials more evenly, wet mixing is preferred.

[0163] Organic solvents such as methanol, acetone, benzene, and carbon tetrachloride can be used as solvents for wet mixing.

[0164] As a mixing method, for example, stationary mixers such as agitators, spiral mixers, ribbon mixers, fluidized bed mixers, rotary mixers such as cylindrical mixers and twin cylindrical mixers, wet pulverizers such as sand mills, ball mills, bead mills, colloid mills, sand grinder mills, vibrators such as paint mixers, and dispersers such as ultrasonic dispersers can be used for mixing.

[0165] The raw material mixture obtained as described above can, for example, be mixed with a flux before the heat treatment process described later.

[0166] Therefore, it is possible to obtain crystals in a more suitable crystallization state (e.g., composed of single crystals).

[0167] As a flux, SrCl2 can be used, for example.

[0168] Alternatively, for example, a mixture of raw materials can be obtained by sequentially adding Sr-sourced substances, Ca-sourced substances, Ga-sourced substances, Ba-sourced substances, etc., to a flux.

[0169] In this situation, the same effect as described above can be achieved.

[0170] (2-2) Heat treatment process In the heat treatment process, the raw material mixture is subjected to heat treatment.

[0171] As a heat treatment method in the heat treatment process, any method that can heat the raw material mixture is acceptable, without any particular limitation, and various devices and methods can be used.

[0172] In the heat treatment process, it is preferable to perform heat treatment at a temperature of 1000°C or higher and 1600°C for 3 hours or more and 10 hours or less.

[0173] This allows for more appropriate reactions during the heat treatment process. Furthermore, crystals can be synthesized through heat treatment at lower temperatures, eliminating the need for specialized equipment and reducing manufacturing costs.

[0174] As described above, the heating temperature in the heat treatment process is preferably 1000°C or higher and 1600°C or lower, more preferably 1050°C or higher and 1550°C or lower, and even more preferably 1100°C or higher and 1500°C or lower. Furthermore, as described above, the heating time in the heat treatment process is preferably 3 hours or higher and 10 hours or lower, more preferably 3.5 hours or higher and 9 hours or lower, and even more preferably 4 hours or higher and 8 hours or lower.

[0175] Therefore, the reactions in the heat treatment process can be carried out more appropriately.

[0176] There are no particular limitations on the atmosphere in the heat treatment process. The heat treatment process can be carried out in the atmosphere or in an inert gas atmosphere.

[0177] Examples of inert gases include argon, helium, and nitrogen.

[0178] In addition, the heat treatment process can be carried out, for example, in a mixed gas atmosphere of inactive gas and hydrogen.

[0179] The proportion of hydrogen in the mixed gas can be set, for example, to be more than 1.0% by volume and less than 10.0% by volume.

[0180] Furthermore, the heat treatment process described above can be carried out in one stage or in two or more stages with altered conditions.

[0181] For example, when the heat treatment process is divided into a first stage and a second stage, the atmosphere can be changed in the first stage and the second stage.

[0182] For example, in the case of heat treatment processes performed in the first and second stages as described above, the first stage can be carried out in the atmosphere, and the second stage can be carried out in a mixed atmosphere of inactive gas and hydrogen.

[0183] Therefore, the reactions in the first and second stages of the heat treatment process can be carried out more appropriately.

[0184] Alternatively, the solid reactants can be pulverized between the first and second stages.

[0185] Therefore, the reaction in the second stage of the heat treatment process can be carried out appropriately.

[0186] The preferred embodiments of the present invention have been described above, but the present invention is not limited thereto.

[0187] For example, the crystals of the present invention are not limited to those manufactured by the above-described manufacturing method, as long as they have an oxide matrix composed of SrCa2Ga2O6.

[0188] Additionally, for example, the crystals of the present invention only require that they contain BaSr2Ca6Ga6O 18 The oxide matrix can be used, and it is not limited to the crystals manufactured by the above-described manufacturing method.

[0189] In addition, the above-described method for manufacturing crystals may include other steps in addition to the steps described above.

[0190] More specifically, for example, in methods for manufacturing crystals, pulverization and classification can be performed after mixing and heat treatment processes, as needed. Pulverization can be either wet or dry. In dry pulverization, depending on the requirements, dry pulverizers such as mortars, roller crushers, atomizers, hammer mills, spray mills, fluid energy mills, and mixers can be used.

[0191] Alternatively, for example, the powdered crystals obtained by pulverization can be dispersed in a liquid and then recovered through solid-liquid separation, thereby removing impurities. This, for example, can further improve the luminescence efficiency of the crystals.

[0192] Solid-liquid separation can be carried out using industrially common methods such as filtration, vacuum filtration, pressure filtration, centrifugation, and decantation. Crystals recovered through solid-liquid separation can be dried using industrially common equipment such as vacuum dryers, hot air dryers, cone dryers, and rotary evaporators.

[0193] The phosphor of the present invention is characterized in that it is composed of a crystal in which a portion of the elements of the crystal in the crystal of the present invention (the crystal of the first embodiment of the present invention or the crystal of the second embodiment of the present invention) are replaced by elements that serve as luminescent centers. That is, the crystal in the crystal of the present invention (the crystal of the first embodiment of the present invention or the crystal of the second embodiment of the present invention) in which a portion of the elements of the crystal are replaced by elements that serve as luminescent centers is a phosphor that serves as a wavelength conversion material.

[0194] In the phosphor of the present invention, the element serving as the luminescent center is the aforementioned element M, that is, one or more selected from the group consisting of Mn, Cr, Fe, Ti, Bi and rare earth elements, preferably one or more selected from the group consisting of Mn, Cr and rare earth elements, more preferably one or more selected from the group consisting of Mn and Cr, and even more preferably Mn.

[0195] As a phosphor of the present invention, examples include phosphors composed of oxides represented by formula (1), oxides represented by formula (2), or oxides represented by formula (3) that are crystals of the present invention (the first type of crystal or the second type of crystal of the present invention).

[0196] The average particle size of the phosphor of the present invention is preferably 1 nm to 100 μm, more preferably 10 nm to 100 μm, and even more preferably 15 nm to 50 μm.

[0197] The fluorescent material of the present invention is characterized in that it contains the phosphor of the present invention. That is, the fluorescent material of the present invention is composed of the phosphor of the present invention, or contains the phosphor of the present invention, and may contain other components as needed.

[0198] Examples of fluorescent materials in this invention include fluorescent materials in which the surface of the phosphor of this invention is coated with a light-transmitting resin. In other words, examples of fluorescent materials in this invention include fluorescent materials comprising the phosphor of this invention and a light-transmitting resin coated on the surface of the phosphor of this invention.

[0199] The haze (JIS-K-7136) of the light-transmitting resin is less than 10%, and the total light transmittance (JIS-K-7361) is more than 80%.

[0200] Examples of light-transmitting resins include polyethylene resin, polyvinyl chloride resin, acrylic resin, polycarbonate resin, polystyrene resin, polyamide resin, polypropylene resin, polyolefin resin, silicone resin, polyethylene terephthalate resin (PET resin), polybutylene terephthalate resin (PBT resin), and polytetramethylene terephthalate resin (PTT).

[0201] When the fluorescent material of the present invention is a fluorescent material comprising the phosphor of the present invention and a light-transmitting resin coated on the surface of the phosphor of the present invention, if the coating amount of the light-transmitting resin is too thin, the coating performance cannot be exerted; if it is too thick, the transmittance is impaired. Therefore, the thickness of the light-transmitting resin is preferably 0.1 nm to 10 μm, more preferably 1 nm to 5 μm.

[0202] By making the fluorescent material of the present invention a fluorescent material comprising the phosphor of the present invention and a light-transmitting resin coated on the surface of the phosphor of the present invention, when manufacturing a resin sheet in which the phosphor of the present invention is dispersed, the phosphor of the present invention is easily dispersed in the resin, and thus a resin sheet in which the phosphor of the present invention is uniformly dispersed is easily obtained.

[0203] In the fluorescent material of the present invention, there are no particular limitations on the method of coating the surface of the phosphor of the present invention with a light-transmitting resin. For example, the following method can be used: the phosphor of the present invention is dispersed in a solvent beforehand, a monomer of a light-transmitting resin is added thereto, a polymerization initiator is then added, and the monomer of the light-transmitting resin is polymerized by heating or the like, thereby generating a light-transmitting resin on the surface of the phosphor of the present invention, and thus coating the surface of the phosphor of the present invention with the light-transmitting resin.

[0204] The fluorescent material of the present invention can be exemplified as a fluorescent material having a core-shell structure, which consists of a core and a shell. The core is composed of the phosphor of the present invention, and the shell is formed on the surface of the core and is composed of a substance with a lower refractive index than the core. As the material for forming the shell, resin materials and inorganic materials can be exemplified. From the viewpoint of light transmittance, a material with a lower refractive index than the core is preferred.

[0205] By making the fluorescent material of the present invention a fluorescent material with a core-shell structure, the core-shell structure is composed of a core and a shell, the core is composed of the phosphor of the present invention, and the shell is formed on the surface of the core and is composed of a material with a lower refractive index than the core. This allows for the improvement of light intake efficiency through the material of the shell, and the improvement of durability due to the shell blocking external deterioration factors.

[0206] The fluorescent material of the present invention may contain a spreading agent. The spreading agent enhances the wettability, adhesion, spreadability, and drape of the phosphor or fluorescent material of the present invention, thereby enabling the phosphor or fluorescent material of the present invention to adhere uniformly. In particular, when using the phosphor or fluorescent material of the present invention as a plant growth promoter for agricultural purposes, and when directly dispersing the phosphor or fluorescent material of the present invention onto plants to allow it to adhere directly to the leaves, stems, etc., a spreading agent is used to ensure that the phosphor or fluorescent material of the present invention adheres uniformly to the plant surface at an appropriate density when dispersing the dispersion containing the phosphor or fluorescent material of the present invention onto the plant surface.

[0207] As a spreading agent, any spreading agent suitable for agricultural use is acceptable without particular restrictions. Examples include: spreading agents with nonionic surfactants, such as surfactants based on polyoxyethylene alkylphenyl ethers, polyoxyethylene alkyl ethers, polyalkylene glycol alkyl ethers, polyoxyethylene fatty acid esters, polyoxyethylene resin esters, polyoxyethylene hexyl fatty acid esters, sorbitan fatty acid esters, and organosilicon surfactants as active ingredients; spreading agents with anionic surfactants, such as surfactants based on naphthylmethane sulfonate, lignin sulfonate, and alkyl sulfosuccinate; and cationic surfactants, such as tetraalkylammonium salts. Commercially available spreading agents include Approach BI (registered trademark, manufactured by Maruwa Biochemical Co., Ltd.), squash (registered trademark, manufactured by Maruwa Biochemical Co., Ltd.), Surfactant WK (registered trademark, manufactured by Maruwa Biochemical Co., Ltd.), MixPower (registered trademark, manufactured by Syngenta Japan Co., Ltd.), and Supply (registered trademark, manufactured by OAT Agrio Co., Ltd.).

[0208] The content of the spreading agent in the fluorescent material of the present invention can be appropriately selected, for example, 0.05 to 10% by mass relative to the phosphor, preferably 0.1 to 1.0% by mass.

[0209] The fluorescent material of the present invention comprises the phosphor of the present invention and a light-transmitting resin coated on the surface of the phosphor of the present invention. When the fluorescent material is dispersed in an aqueous dispersion solvent such as water, alcohol, or a mixture thereof, or in an oleophilic dispersion solvent such as aromatic hydrocarbons such as toluene, xylene, and benzene, aliphatic hydrocarbons such as pentane and hexane, ethers such as dioxane and dibutyl ether, or esters such as ethyl acetate, the fluorescent material of the present invention and the spreading agent can be mixed in the dispersion solvent for use.

[0210] The phosphor of the present invention can be used in aqueous dispersion solvents such as water, alcohol, and mixed solvents thereof, or in lipophilic dispersion solvents such as aromatic hydrocarbons such as toluene, xylene, and benzene, aliphatic hydrocarbons such as pentane and hexane, ethers such as dioxane and dibutyl ether, and esters such as ethyl acetate. In this case, the phosphor of the present invention and the developing agent can be mixed in the dispersion solvent for use.

[0211] As an example of using the phosphor or fluorescent material of the present invention as a plant growth material for agricultural purposes, the following method can be cited: dispersing the phosphor or fluorescent material of the present invention in an aqueous solvent, directly distributing the resulting dispersion onto the plant, so that the phosphor of the present invention adheres to the surface of the plant's leaves, stems, etc.

[0212] The phosphor or fluorescent material of the present invention can be used for any purpose that requires emitting light in the visible to infrared region. It can also be used for any purpose that requires converting light preferably from 300 to 600 nm, preferably from 300 to 550 nm, into light from 650 to 900 nm, preferably from 650 to 750 nm and emitting light. Examples of uses for the phosphor or fluorescent material of the present invention include phosphors for white LEDs, ultraviolet absorbers, phosphors for wavelength conversion films for silicon solar cells, wavelength conversion materials for agricultural sheets for plant growth control, security applications, and biosensors.

[0213] The resin sheet of the present invention is characterized in that it is composed of a light-transmitting resin substrate and contains the phosphor or fluorescent material of the present invention.

[0214] The resin sheet of the present invention is composed of a light-transmitting resin substrate. That is, the resin sheet of the present invention is formed by molding a light-transmitting resin into a sheet shape. The light-transmitting resin involved in the resin sheet of the present invention can be exemplified by the same light-transmitting resin involved in the fluorescent material of the present invention.

[0215] The content of the phosphor or fluorescent material of the present invention in the resin sheet of the present invention is not particularly limited, but is preferably 1 to 20% by mass, more preferably 1 to 10% by mass.

[0216] The resin sheet of the present invention can be a resin sheet with a thickness of 250 μm or more, generally referred to as a "sheet", a resin sheet with a thickness of less than 250 μm, or a resin sheet generally referred to as a "foil". That is, the thickness of the resin sheet of the present invention is not particularly limited and can be appropriately selected according to the period of use, the environment of use, and the state of use.

[0217] When the resin sheet of the present invention is used as a wavelength conversion sheet for agricultural applications, for example, the thickness of the resin sheet of the present invention is preferably 10 to 150 μm.

[0218] The resin sheet of the present invention may contain spreading agents, agricultural materials, pesticides, biostimulants, silica and other inorganic substances as needed.

[0219] The resin sheet of the present invention is suitable for use as an agricultural sheet.

[0220] Example The present invention will now be described in detail based on specific embodiments, but the present invention is not limited thereto.

[0221] In addition, for treatments where atmospheric and temperature conditions are not specifically specified, they shall be carried out in the atmosphere at 25°C.

[0222] (3) Evaluation methods First, regarding the analytical methods used in the evaluation of the following embodiments, the measurement conditions are summarized below.

[0223] (3-1) X-ray diffraction Device: MX-Labo (Mac Science Co., Ltd.) X-rays: CuKα (λ = 1.54056 Å) Current: 25mA Voltage: 40kV (3-2) Photoluminescence Device: FP-6500 (JASCO Corporation) Xenon lamp as the radiation source: 150W Excitation wavelength: 465nm The intensity of the emitted light was measured when the light was irradiated with excitation light (λex = 435 nm).

[0224] (4) Crystal manufacturing (Example 1) First, prepare SrCO3 powder as Sr source, CaCO3 powder as Ca source, Ga2O3 powder as Ga source, and MnO2 powder as Mn source, and weigh them according to the molar ratio of Sr, Ca, Ga and Mn as 1.00∶2.00∶1.94∶0.06.

[0225] Next, the above raw materials are mixed using an agate mortar and pestle to obtain a raw material mixture. At this point, acetone is used as a solvent for wet mixing.

[0226] Next, the same mass of flux (SrCl2) was added to the above raw material mixture, and the mixture was heated to 1200°C in the atmosphere and kept at 1200°C for 6 hours to obtain a solid substance.

[0227] The solid material was then cooled to room temperature to obtain crystals.

[0228] For the crystals of Example 1, the crystalline phase was identified by X-ray diffraction according to the above-described measurement conditions.

[0229] The crystal in this embodiment is composed of SrCa2(Ga) 0.97 Mn0.03 The single crystal with the composition represented by 2O6.

[0230] The detailed crystallographic data obtained from the structural analysis of the crystals manufactured in Example 1 are as follows.

[0231] Crystal system: Cubic Crystal lattice shape: face-centered cubic lattice Lattice constants: a = 15.475 Å, V = 3705.8.475 ų Space Group: F432 z-value: 24 Rl factor: 0.0344 wR2 factor: 0.0785 (Example 2) First, prepare SrCO3 powder as Sr source, CaCO3 powder as Ca source, Ga2O3 powder as Ga source, and MnO2 powder as Mn source, and weigh them according to the molar ratio of Sr, Ca, Ga and Mn as 1.00∶2.00∶1.94∶0.06.

[0232] Next, the above raw materials are mixed using an agate mortar and pestle to obtain a raw material mixture. At this point, acetone is used as a solvent for wet mixing.

[0233] The raw material mixture was placed on a plate made of Pt and then placed in an alumina boat. It was then heat-treated at 1200°C for 6 hours in the atmosphere to obtain a solid substance.

[0234] The solid material was then cooled to room temperature. The resulting product was pulverized and sieved to obtain a powdery crystalline substance.

[0235] The crystal in this embodiment is composed of SrCa2(Ga) 0.97 Mn 0.03 The single crystal with the composition represented by 2O6.

[0236] (Examples 3-10) The amounts of Sr, Ca, Ga, and Mn sources were varied, but the crystals were produced in the same manner as in Example 2.

[0237] (Example 11) In the preparation of the raw material mixture, Cr2O3 powder as the Cr source was used instead of MnO2 powder as the Mn source. Otherwise, crystals were produced in the same manner as in Example 2.

[0238] Furthermore, the proportion of components other than the single crystal in the crystals obtained in each of the embodiments is less than 1% by mass.

[0239] exist Figure 2 The X-ray diffraction pattern of the crystal of Example 1 is shown in the figure.

[0240] In addition, Figure 2 The X-ray diffraction pattern shown also includes, for reference, data from the ICSD (Inorganic Crystal Structure Database) of Sr3Ga2O6, as well as data on SrCa2Ga. 1.87 Mn 0.13 Simulation results of the X-ray diffraction pattern of O6.

[0241] In addition, Figure 3 The image shows the powder X-ray diffraction patterns of the crystals from Examples 2-10. (From...) Figure 3 It can be seen that the same peaks as those in the crystals of Examples 2 to 10 were also observed in the crystals of Example 1.

[0242] In addition, Figure 4 , Figure 5 The results of photoluminescence measurements of the crystals from Example 1 are shown below. Figure 4 It can be seen that in the crystal of Example 1, excitation occurs in the ultraviolet region, resulting in green luminescence. Furthermore, from... Figure 5 It is also known that in the crystals of Example 1, there are Mn-derived molecules around 700 nm. 4+ The light emission was observed. The same results were obtained for Examples 2-10.

[0243] exist Figure 6 The figure shows the relationship between the luminescence intensity when the crystals of Examples 2 to 9 are irradiated with ultraviolet light of a predetermined intensity (365 nm). As can be seen from the figure, high luminescence intensity is obtained in the phosphors of Examples 2 to 8, and particularly high luminescence intensity is obtained in the phosphor of Example 2, where x in Formula (1) is 0.03.

[0244] In addition, Figure 7 The image shows photographs of the crystal of Example 1 when irradiated with an indoor lamp, when irradiated with ultraviolet light with a wavelength of 254 nm, and when irradiated with ultraviolet light with a wavelength of 365 nm.

[0245] It appears reddish-gray under indoor lighting, green when irradiated with ultraviolet light at a wavelength of 254 nm, and red when irradiated with ultraviolet light at a wavelength of 365 nm. The same results were obtained for the crystals of Examples 2-9.

[0246] In addition, Figure 8 The image shows the powder X-ray diffraction pattern of the crystals of Example 11.

[0247] In addition, Figure 8The X-ray diffraction pattern shown also includes, for reference, data from the ICSD (Inorganic Crystal Structure Database) of Sr3Ga2O6, as well as data on SrCa2Ga. 1.87 Mn 0.13 Simulation results of the X-ray diffraction pattern of O6.

[0248] In addition, Figure 9 The results of photoluminescence measurements of the crystals in Example 11 are shown below. Figure 9 It can be seen that in the crystal of Example 11, there is excitation in the ultraviolet region and luminescence in the near-infrared region.

[0249] Furthermore, a portion of the elements constituting the oxide matrix (SrCa2Ga2O6) of the various embodiments was replaced with elements other than Mn and Cr, more specifically, with Bi, Pr, Sm, Eu, Tb, and Tm. Otherwise, crystals were manufactured in the same manner as in the various embodiments. They were evaluated in the same way as described above, and the results showed that the Bi-containing crystals appeared white under indoor lighting and exhibited a long blue afterglow when irradiated with ultraviolet light at a wavelength of 254 nm, and a long yellow afterglow when irradiated with ultraviolet light at a wavelength of 365 nm. The Pr-containing crystals appeared yellow under indoor lighting and exhibited a long yellow or blue afterglow when irradiated with ultraviolet light at a wavelength of 254 nm. The Sm-containing crystals appeared yellow or white under indoor lighting and exhibited a long yellow or blue afterglow when irradiated with ultraviolet light at a wavelength of 254 nm. It appears red or blue, turns red when irradiated with ultraviolet light at a wavelength of 365 nm, appears yellow or white under indoor light in crystals containing Eu, appears red when irradiated with ultraviolet light at a wavelength of 254 nm, appears red when irradiated with ultraviolet light at a wavelength of 365 nm, appears yellow under indoor light in crystals containing Tb, exhibits a long green afterglow when irradiated with ultraviolet light at a wavelength of 254 nm, appears yellow or white under indoor light in crystals containing Tm, and exhibits a long blue afterglow when irradiated with ultraviolet light at a wavelength of 254 nm.

[0250] Furthermore, various changes were made to the processing temperature in the heat treatment process within the range of 1000°C to 1600°C, and various changes were made to the processing time in the heat treatment process within the range of 3 hours to 10 hours. Otherwise, crystals were manufactured in the same manner as in the aforementioned embodiments, and they were evaluated in the same manner as described above. As a result, the same results as in the corresponding embodiments were obtained.

[0251] (Example 12) First, prepare BaCO3 powder as Ba source, SrCO3 powder as Sr source, CaCO3 powder as Ca source, Ga2O3 powder as Ga source, and MnO2 powder as Mn source, and weigh them according to the molar ratio of Ba, Sr, Ca, Ga and Mn as 1.00∶2.00∶6.00∶5.76∶0.24.

[0252] Next, the above raw materials are mixed using an agate mortar and pestle to obtain a raw material mixture. At this point, acetone is used as a solvent for wet mixing.

[0253] Next, the above raw material mixture was heated to 1000°C in the atmosphere and held at 1000°C for 4 hours. It was then temporarily removed and ground using an agate mortar. Subsequently, it was heated to 1200°C and held at 1200°C for 6 hours, thereby obtaining BaSr2Ca6(Ga 0.96 Mn 0.04 6O 18 The powder represents the composition of the product.

[0254] (Examples 13-18) The amounts of Ba source, Sr source, Ca source, Ga source, and Mn source were changed, but the crystals were manufactured in the same manner as in Example 12.

[0255] The average particle size of the crystals from Examples 12-18 is shown in Table 1. The average particle size was determined by SEM following the steps outlined below.

[0256] <Determination of average particle size> Using a scanning electron microscope (SEM: JSM-7900F, manufactured by NEC Corporation), particle images were captured under an accelerating voltage of 8 kV. From the resulting SEM images, 100 particles were randomly selected, and the minor diameter of each particle was measured. The average diameter was calculated as the mean particle size. WinROOF image analysis and measurement software was used for image analysis.

[0257] Additionally, the crystals obtained in Example 13 were BaSr2Ca6 (Ga 0.99 Mn 0.01 6O 18 The powder shown has the following composition; additionally, the crystals obtained in Example 14 are BaSr2Ca6 (Ga 0.98 Mn 0.02 6O 18 The powder shown has the following composition; additionally, the crystals obtained in Example 15 are BaSr2Ca6 (Ga 0.97 Mn 0.03 6O 18The powder shown has the following composition; additionally, the crystals obtained in Example 16 are BaSr2Ca6 (Ga 0.95 Mn 0.05 6O 18 The powder shown has the following composition. Additionally, the crystals obtained in Example 17 were BaSr2Ca6 (Ga 0.94 Mn 0.06 6O 18 The powder shown has the following composition; additionally, the crystals obtained in Example 18 are BaSr2Ca6 (Ga 0.93 Mn 0.07 6O 18 The powder shown has the following composition.

[0258] exist Figure 11 The X-ray diffraction patterns of the crystals of Examples 12-18 are shown in the figure.

[0259] In addition, Figure 11 In the X-ray diffraction patterns shown, data for the single-crystal X-ray diffraction pattern of Sr3Ga2O6 are also presented for reference. The same peaks were confirmed in the crystals of Examples 12-18.

[0260] In addition, Figure 12 The results of photoluminescence measurements for the crystals of Examples 12-18 are shown. As a comparative example, for Ca... 14 Al 10 Zn6O 35 Mn 4+ The same measurements were performed. Table 1 shows the intensity of the absorption peak near 715 nm, the absorption peak near 350 nm, and the emission peak near 460 nm. Figure 12 As shown in Table 1, among the crystals of Examples 12-18, the phosphor of Example 12, in which x is 0.04 in Formula (2), exhibited particularly high luminescence intensity. The respective intensities are recorded as the relative intensities obtained when commercially available YAG is excited at 450 nm and the peak of the luminescence spectrum from 470 to 800 nm is set to 1.

[0261]

[0262] In the table, CZA represents Ca 14 Al 10 Zn6O 35 Mn 4+ The absorption intensity near 350nm is the peak of the absorption peak near 330nm, the absorption intensity near 460nm is the peak of the absorption peak near 450nm, and the emission intensity near 715nm is the peak of the emission peak near 715nm.

[0263] (Example 19) 120 g of the crystals obtained in Example 15 were dispersed in 250 mL of ethanol. Next, 1 g of 2-methacryloyloxyethyl phosphoric acid was added to the dispersion. Then, the dispersion was placed in a 500 mL round-bottom flask with a stirring blade and mechanically stirred at 400 rpm and 40°C for 3 hours. Next, 10 mg of AIBN (azobisisobutyronitrile) was dissolved in (100) mL of ethanol and added dropwise to the dispersion. Afterward, the reaction mixture was heated to 75°C and stirred at 800 rpm for 2 hours. After 2 hours, heating was stopped, and the mixture was cooled to room temperature while stirring. After cooling to room temperature, stirring was stopped, and the supernatant was removed. The resulting fluorescent material was ultrasonically cleaned three times with 300 mL of ethanol and dried to obtain a transparent resin-coated fluorescent material with the surface of the crystals coated with a transparent resin.

[0264] (Example 20) The transparent resin-coated fluorescent material obtained in Example 15 was dispersed in water at a solid content concentration of 1.0% by mass to obtain a dispersion.

[0265] (Comparative Example 1) Silica particles with an average particle size of 20 μm were dispersed in water at a solid content concentration of 1.0% by mass to obtain a dispersion.

[0266] An experiment was conducted using sunny red lettuce to promote plant growth. The experimental steps are as follows.

[0267] In a hydroponic cultivation system (manufactured by UING Corporation) equipped with white LEDs, red leaf lettuce seeds were placed on a sponge, and 8 seedlings on the seventh day after sowing were sprayed 10 times with the dispersion of Example 20. Then, on the fourteenth day, each of the 8 seedlings was sprayed 10 times in the same manner, and harvesting was carried out on the 21st day after sowing. The same procedure was performed with the dispersion of Comparative Example 1, and harvesting was carried out on the 21st day after sowing.

[0268] Next, the fresh weight immediately after harvest was measured. The results showed that the fresh weight of the fluorescent material coated with the transparent resin obtained in Example 19 was 6.9 g, and the fresh weight of the silica particles in Comparative Example 1 was 6.0 g. It was confirmed that the fresh weight of the fluorescent material coated with the transparent resin obtained in Example 19 was more than 15% by mass compared with the silica particles in Comparative Example 1.

[0269] Industrial applicability The crystals of the present invention are composed of relatively inexpensive and stably obtainable components, and can be used as phosphors with excellent properties. Therefore, the crystals of the present invention have industrial applicability.

[0270] Furthermore, the phosphor, fluorescent material, and resin sheet of the present invention are suitable for use in the field of red emission based on wavelength conversion, particularly in the field of plant growth promoting materials for agricultural applications.

Claims

1. A crystalline substance, characterized in that, The crystal has an oxide matrix composed of SrCa2Ga2O6.

2. The crystal according to claim 1, characterized in that, A portion of the Ga constituting the oxide matrix is ​​replaced by other elements.

3. The crystal according to claim 2, characterized in that, The other elements are selected from one or more of the group consisting of Mn, Cr, Fe, Ti, Bi, and rare earth elements.

4. The crystal according to claim 2, characterized in that, The substitution ratio of Ga by the other elements is less than 0.10 in molar ratio.

5. The crystal according to claim 2, characterized in that, The crystal is the crystal shown in the following formula (1). SrCa2(Ga) （1-x） M x (2O6(1)) In equation (1), M is one or more elements selected from the group consisting of Mn, Cr, Fe, Ti, Bi and rare earth elements, satisfying the relationship 0 < x ≤ 0.

10.

6. A crystalline substance, characterized in that, The crystal has a composition of BaSr2Ca6Ga6O 18 The oxide parent body is formed.

7. The crystal according to claim 6, characterized in that, A portion of the Ga constituting the oxide matrix is ​​replaced by other elements.

8. The crystal according to claim 7, characterized in that, The other elements replacing Ga are selected from one or more elements chosen from the group consisting of Mn, Cr, Fe, Ti, Bi, and rare earth elements.

9. The crystal according to claim 7, characterized in that, The substitution ratio of Ga by the other elements is less than 0.10 in molar ratio.

10. The crystal according to claim 7, characterized in that, The crystal is the crystal shown in the following formula (2). BaSr2Ca6(Ga （1-x） M x )6O 18 (2) In equation (2), M is one or more elements selected from the group consisting of Mn, Cr, Fe, Ti, Bi and rare earth elements, satisfying the relationship 0 < x ≤ 0.

10.

11. A phosphor, characterized in that, The phosphor is composed of the crystal as described in claim 3 or 8.

12. A fluorescent material, characterized in that, The fluorescent material is formed by coating the surface of the phosphor of claim 11 with a light-transmitting resin.

13. A resin sheet, characterized in that, The resin sheet is formed from a light-transmitting resin substrate and contains the phosphor as described in claim 11.

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