Crystal body, phosphor, fluorescent material, and resin sheet

Abstract

Disclosed is a crystal body characterized by having an oxide base material that is composed of SrCa2Ga2O6 or BaSr2Ca6Ga6O18. According to the present invention, it is possible to provide a crystal body which is composed of relatively inexpensive and stably available components, and can be used as a phosphor that has excellent characteristics.

Description

Crystals, phosphors, fluorescent materials and resin sheets

[0001] The present invention relates to a crystal, a phosphor, a fluorescent material, and a resin sheet.

[0002] White LEDs generally have a yellow phosphor (or green and red phosphors) placed on a blue LED chip, which is excited by light from the blue LED (λ=approximately 460 nm) to emit yellow light, which is then combined with the blue light from the blue LED itself to produce a mixed color white light (see, for example, Patent Document 1).

[0003] In particular, for backlights of liquid crystal displays, which must contain the three primary colors of light, phosphors that emit green light in narrow bands and red light in narrow bands are required.

[0004] Most of the current phosphors are manufactured by doping rare earth or transition metal ions as luminescent ions into oxides, nitrides, or fluorides as a base material.

[0005] This leads to an increase in the cost of the phosphor, and is also undesirable from the viewpoint of reducing the amount of rare metals used.

[0006] In recent years, in particular, infrared-emitting materials that absorb light in the ultraviolet to visible light range and emit light in the infrared range have been attracting attention. For example, applications to the following devices are possible.

[0007] First, silicon solar cells have undergone many improvements over the years, but it still takes several years to improve their efficiency by just 0.1%. Wavelength conversion film technology for solar cells is attracting attention as a solution to this problem. This technology can easily improve the efficiency of solar cells by converting ultraviolet and blue light, which solar cells cannot absorb, into wavelengths that solar cells can absorb. In particular, no materials capable of highly efficient conversion into the infrared region have yet been found, and there is a strong demand for their development.

[0008] Furthermore, organic high-conversion-efficiency materials are also used in technology to promote plant growth by adding wavelength-converting materials to polymer sheets in agricultural greenhouses and tunnels, but their use is limited by problems such as poor weather resistance and a short Stokes shift, which results in the absorption of a large amount of light in the visible light range.On the other hand, infrared-emitting inorganic wavelength-converting materials have a significant advantage over organic materials in terms of stability, but no highly efficient materials have been found to date.

[0009] In the field of security technology, security ink that emits visible light when irradiated with ultraviolet light has been used for some time, but in the future, technology with even higher security performance will be required. Security ink that absorbs visible light and converts it to near-infrared light has the property of being invisible to the naked eye, and is therefore expected to have higher security performance than conventional products, and there is hope for the development of more efficient materials.

[0010] Other potential applications include medical technology such as improving skin conditions, displays, and various LEDs, and interest in highly efficient infrared-emitting materials is growing.

[0011] Until now, rare earth elements (Pr ３＋ , Nd ３＋ , Tm ３＋ , Eu ２＋ etc.), or transition metal elements (Cr ３＋ , Ni ２＋ , V ２＋ , Mn ４＋ There are reports of the use of such methods (Non-Patent Documents 1 and 2).

[0012] JP 2007-326981 A

[0013] FAKroger, Some Aspects of the Luminescence of Solids.(1948)Toda K., Sato M., Chem Lett. 2014; 43(8)

[0014] In order for crystals to be widely used for various purposes, including as phosphors, it is necessary to develop crystals with novel structures that are composed of relatively inexpensive and stably available components and that exhibit new properties.

[0015] Furthermore, for phosphor applications, there is a demand for crystals that are composed of components that are relatively inexpensive and stably available, and that emit light with high efficiency in the visible to infrared light range.

[0016] Therefore, an object of the present invention is to solve at least one of the following problems: An object of the present invention is to provide a crystal having a novel structure, which is composed of components that are relatively inexpensive and stably available. An object of the present invention is to provide a crystal that is composed of components that are relatively inexpensive and stably available, which can be used as a phosphor with excellent properties.

[0017] The above object is achieved by the present invention. ２ Ga ２ O ６ The present invention is characterized by having an oxide matrix composed of:

[0018] The crystal of the present invention is SrCa ２ Ga ２ O ６ It is sufficient that the crystal has an oxide matrix composed of the above, and it may contain elements different from the elements that compose the oxide matrix. The properties of the crystal can be suitably adjusted by the type and content of such elements.

[0019] As described above, the crystal of the present invention may contain elements (hereinafter also referred to as "other elements") other than the elements constituting the oxide matrix (i.e., Sr, Ca, Ga, and O).

[0020] For example, at least one of the Sr site, Ca site, and Ga site constituting the oxide matrix may have at least a portion of the atoms constituting the site substituted with another element.

[0021] However, the content of other elements in the crystal 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.

[0022] In particular, it is preferable that a part of Ga constituting the oxide matrix is ​​substituted with another element, which makes it possible to more suitably obtain a crystal having the crystal structure of the oxide matrix.

[0023] Examples of the other elements include 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, and Lu), and one or more elements selected from these can be used. However, one or more elements selected from the group consisting of Mn, Cr, Bi, and rare earth elements are preferred, one or more elements selected from the group consisting of Mn and Cr are more preferred, and Mn is even more preferred. This allows for the production of a crystal that emits light when excited with near-ultraviolet to blue light.

[0024] In the crystal of the present invention, it is preferable that a portion of Ga constituting the oxide matrix is ​​substituted with another element.

[0025] In the crystal of the present invention, the other elements are preferably at least one selected from the group consisting of Mn, Cr, Fe, Ti, Bi and rare earth elements.

[0026] In the crystal of the present invention, the substitution ratio of Ga by the other element is preferably 0.10 or less in molar ratio.

[0027] The crystal of the present invention is preferably represented by the following formula (1): SrCa ２ (Ga （１－ｘ） M ｘ ) ２ O ６ (1) (In formula (1), M is one or more elements selected from the group consisting of Mn, Cr, Fe, Ti, Bi, and rare earth elements, and satisfies the relationship 0<x≦0.10.)

[0028] The crystal of the present invention is BaSr ２ Ca ６ Ga ６ O １８ The present invention is characterized by having an oxide matrix composed of:

[0029] In the crystal of the present invention, it is preferable that a portion of Ga constituting the oxide matrix is ​​substituted with another element.

[0030] In the crystal of the present invention, the other element substituting for Ga is preferably one or more elements selected from the group consisting of Mn, Cr, Fe, Ti, Bi and rare earth elements.

[0031] In the crystal of the present invention, the substitution ratio of Ga by the other element is preferably 0.10 or less in molar ratio.

[0032] The crystalline body of the present invention is preferably represented by the following formula (2): BaSr ２ Ca ６ (Ga （１－ｘ） M ｘ ) ６ O １８ (2) (In formula (2), M is one or more elements selected from the group consisting of Mn, Cr, Fe, Ti, Bi, and rare earth elements, and satisfies the relationship 0<x≦0.10.)

[0033] The phosphor of the present invention is characterized by comprising the above-described crystal of the present invention.

[0034] The fluorescent material of the present invention is characterized in that the surface of the phosphor of the present invention is coated with a light-transmitting resin.

[0035] The resin sheet of the present invention is characterized by comprising a light-transmitting resin substrate and containing the phosphor of the present invention.

[0036] According to the present invention, it is possible to provide a crystal having a novel structure, which is composed of components that are relatively inexpensive and stably available. According to the present invention, it is possible to provide a crystal that is composed of components that are relatively inexpensive and stably available, which can be used as a phosphor with excellent properties.

[0037] 1 is a flowchart showing an example of the steps of a method for producing a crystalline body of the present invention. 2 is a diagram showing an X-ray diffraction pattern of the crystalline body of Example 1. 3 is a diagram showing powder X-ray diffraction patterns of the crystalline bodies of Examples 2 to 10. 4 is a diagram showing the results of photoluminescence measurement for the crystalline body of Example 1. 5 is a diagram showing the results of photoluminescence measurement for the crystalline body of Example 1. 6 is a diagram showing the relationship between luminescence intensity when the crystalline bodies of Examples 2 to 9 are irradiated with ultraviolet light (365 nm) of a predetermined intensity. 7 is a diagram showing photographs of the crystalline body of Example 1 irradiated with room light, ultraviolet light having a wavelength of 254 nm, and ultraviolet light having a wavelength of 365 nm. 8 is a diagram showing a powder X-ray diffraction pattern of the crystalline body of Example 11. 9 is a diagram showing the results of photoluminescence measurement for the crystalline body of Example 11. ２ Ca ６ Ga ６ O １８ 1 is a schematic diagram showing a crystalline body having an oxide matrix composed of: 1. A diagram showing powder X-ray diffraction patterns of the crystalline bodies of Examples 12 to 18. 2. A diagram showing the results of photoluminescence measurements when the crystalline bodies of Examples 12 to 18 are excited at around 330 nm. 3. A diagram showing the results of photoluminescence measurements when the crystalline bodies of Examples 12 to 18 are excited at around 460 nm.

[0038] Preferred embodiments of the present invention will be described in detail below. <Crystalline body of the first embodiment of the present invention> (1) Crystalline body First, the crystalline body of the present invention will be described.

[0039] In the following explanation, the crystal of the present invention will be mainly described as an optical material, particularly a phosphor, but is not limited to this, and the crystal of the present invention can be used in a wide range of applications as various optical materials other than phosphors or as materials other than optical materials, as will be described later.

[0040] The crystal of the present invention is SrCa ２ Ga ２ O ６ The present invention is characterized by having an oxide matrix composed of:

[0041] This configuration allows for the provision of a crystal that is composed of relatively inexpensive and stably available components and can be used as a phosphor with excellent properties. In particular, the crystal has a novel crystal structure that differs from conventional crystals, and exhibits fluorescent properties not obtainable with compounds of known crystal structures, such as red light emission at higher wavelengths (emission at wavelengths longer than 670 nm) and narrower bands than compounds of conventional crystal structures. Therefore, the crystal of the present invention can be suitably applied to, for example, 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, biosensors, and the like. Furthermore, as will be described in detail later, the crystal of the present invention is a SrCa ２ Ga ２ O ６ It is sufficient that the crystal has an oxide matrix composed of the above, and it may contain elements different from the elements that compose the oxide matrix. The properties of the crystal can be suitably adjusted by the type and content of such elements.

[0042] As described above, the crystal of the present invention may contain elements (hereinafter also referred to as "other elements") other than the elements constituting the oxide matrix (i.e., Sr, Ca, Ga, and O).

[0043] For example, at least one of the Sr site, Ca site, and Ga site constituting the oxide matrix may have at least a portion of the atoms constituting the site substituted with another element.

[0044] However, the content of other elements in the crystal 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.

[0045] In particular, it is preferable that a part of Ga constituting the oxide matrix is ​​substituted with another element, which makes it possible to more suitably obtain a crystal having the crystal structure of the oxide matrix.

[0046] Examples of the other elements include 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, and Lu), and one or more selected from these can be used. However, one or more selected from the group consisting of Mn, Cr, Bi, and rare earth elements is preferred, one or more selected from the group consisting of Mn and Cr is more preferred, and Mn is even more preferred. This allows for the production of a crystal that emits light when excited with near-ultraviolet to blue light.

[0047] In the crystalline form of the present invention, Mn is tetravalent (Mn ４＋ ) is preferably contained in the state.

[0048] This results in a crystal that emits red light with a peak at 712 nm when irradiated with light from near ultraviolet to blue.

[0049] The substitution ratio of Ga by the other element is preferably 0.10 or less, more preferably 0.002 or more and 0.08 or less, and even more preferably 0.01 or more and 0.07 or less, in molar ratio.

[0050] This allows the crystal to exhibit better fluorescent properties (especially luminescence intensity).

[0051] In particular, the crystal of the present invention is preferably represented by the following formula (1): SrCa ２ (Ga （１－ｘ） M ｘ ) ２ O ６ (1) (In formula (1), M is one or more elements selected from the group consisting of Mn, Cr, Fe, Ti, Bi, V, and rare earth elements, and satisfies the relationship 0<x≦0.10.)

[0052] This allows the crystal to exhibit particularly excellent fluorescent properties (especially luminescence intensity).

[0053] In the above formula (1), x may satisfy the relationship 0<x≦0.10, but preferably satisfies the relationship 0.001≦x≦0.09, more preferably the relationship 0.002≦x≦0.08, and even more preferably the relationship 0.01≦x≦0.07, thereby enabling the aforementioned effects to be exhibited more significantly.

[0054] Furthermore, M in the above formula (1) may be at least one element selected from the group consisting of Mn, Cr, Fe, Ti, Bi, V and rare earth elements, but is preferably at least one element selected from the group consisting of Mn and Cr, and more preferably Mn, which allows the above-mentioned effects to be more significantly exhibited.

[0055] The crystalline substance of the present invention may have a crystalline structure at least in part, and may also contain a portion of amorphous structure.

[0056] However, the proportion of the portion having a crystalline structure in the crystalline substance 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.

[0057] The ratio of the crystalline structure portion to the amorphous structure portion in the crystalline substance of the present invention can be determined by measurement using X-ray diffraction.

[0058] The crystal of the present invention may be used for any purpose, and examples of uses of the crystal of the present invention include ultraviolet absorbers, optical sensors, wavelength conversion materials, and optical materials such as phosphors.

[0059] In particular, the crystal of the present invention is preferably applied to phosphors because it is composed of components that are relatively inexpensive and stably available and exhibits the excellent optical properties described above.

[0060] Furthermore, the crystal of the present invention can be excited by short-wavelength near-ultraviolet to blue light and emit long-wavelength red to near-infrared light, and therefore can be suitably applied, for example, to wavelength conversion materials for wavelength conversion films for solar cells such as silicon.

[0061] The phosphor can be used, for example, as a light-emitting element for displays, a light-emitting element for lighting, a scintillator, etc.

[0062] The ultraviolet absorber can be used as an ultraviolet absorbing material in, for example, ultraviolet absorbing sheets, foundations, lotions, sunscreens, and the like.

[0063] The optical sensor can be used, for example, as a light detection element in a photodetector.

[0064] Ga at the Ga site may be substituted with elements other than Mn, provided that the effects of the present invention are not impaired. Examples of other elements at the Ga site 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 other elements are contained at the Ga site as trivalent elements.

[0065] The substitution ratio of elements other than Mn at the Ga site is preferably 20 mol % or less, more preferably 5 mol % or less, in terms of the mol % of other elements relative to all elements at the Ga site ((number of moles of elements other than Mn / number of moles of all elements at the Ga site)×100).

[0066] Sr at the Sr site may be substituted with other elements as long as the effects of the present invention are not impaired. Examples of such other elements include Mg, Zn, Cu, Co, Ni, Fe, Mn, Ce, and Sn. In the crystal of the present invention, the other elements are contained in the Sr site as divalent elements.

[0067] The substitution ratio of the other element at the Sr site is preferably 20 mol % or less, more preferably 5 mol % or less, in terms of the mole % of the other element relative to all elements at the Sr site ((number of moles of other elements / number of moles of all elements at the Sr site) × 100).

[0068] Ca at the Ca site may be substituted with other elements as long as the effects of the present invention are not impaired. Examples of such other elements include Mg, Zn, Cu, Co, Ni, Fe, Mn, Ce, and Sn. In the crystal of the present invention, the other elements are contained in the Ca site as divalent elements.

[0069] The substitution ratio of the other element at the Ca site is preferably 20 mol % or less, more preferably 5 mol % or less, in terms of the mol % of the other element relative to all elements at the Ca site ((moles of other elements / moles of all elements at the Ca site)×100).

[0070] In the crystal of the present invention, the molar ratio of each site in the entire crystal is preferably "total Sr site elements:total Ca site elements:total Ga site elements:total O elements at O ​​sites = 1.00:2.00:2.00:6.00," but the ratio of one or more sites may deviate from the above range as long as the effects of the present invention are not impaired. Preferably, the molar ratio is "total Sr site elements:total Ca site elements:total Ga site elements:total O elements at O ​​sites = 1.00±0.05:2.00±0.10:2.00±0.10:6.00±0.30."

[0071] <Crystal of the second form of the present invention> (1) Crystal In the following explanation, the crystal of the present invention will be mainly described as an optical material, particularly a phosphor, but is not limited to this, and the crystal of the present invention can be used in a wide range of applications as various optical materials other than phosphors or materials other than optical materials, as described below.

[0072] The crystal of the present invention is BaSr ２ Ca ６ Ga ６ O １８ That is, the crystal of the present invention is characterized by having an oxide matrix composed of BaSr ２ Ca ６ Ga ６ O １８ and has an oxide matrix composed of at least Ba, Sr, Ca and Ga.

[0073] BaSr ２ Ca ６ Ga ６ O １８ The crystal having an oxide matrix composed of BaSr will be explained with reference to FIG. ２ Ca ６ Ga ６ O １８10 is a schematic diagram showing a crystal having an oxide matrix composed of BaSr ２ Ca ６ Ga ６ O １８ The crystal structure is a crystal structure in which the constituent elements are arranged at the Ba site, the Sr site, the Ca site, and the Ga site. The crystal (1) in FIG. 10 is composed of Ba (2) arranged at the Ba site, Sr (3) arranged at the Sr site, Ca (4) arranged at the Ca site, Ga (5) arranged at the Ga site, and O (6). The crystal (1) is composed of BaSr ２ Ca ６ Ga ６ O １８ In the crystal structure of the above, some of the Ga atoms in the Ga sites are substituted with Mn atoms.

[0074] In the present invention, BaSr ２ Ca ６ Ga ６ O １８ The oxide matrix composed of BaSr ２ Ca ６ Ga ６ O １８ and the base material is BaSr, in which a part of the Ba site, Sr site, Ca site, or Ga site is substituted with another element. ２ Ca ６ Ga ６ O １８ That is, in the present invention, BaSr ２ Ca ６ Ga ６ O １８ The crystal having an oxide matrix composed of BaSr ２ Ca ６ Ga ６ O １８ and has the same crystal structure as BaSr ２ Ca ６ Ga ６ O １８ The crystal of the present invention is a crystal having BaSr as a base material, in which a part of the Ba site, Sr site, Ca site and / or Ga site is substituted with other elements. ２ Ca６ Ga ６ O １８ It is sufficient that the crystal has an oxide matrix composed of the above, and it may contain elements different from the elements that compose the oxide matrix. The properties of the crystal can be suitably adjusted by the type and content of such elements.

[0075] In the present invention, BaSr ２ Ca ６ Ga ６ O １８ The crystal structure of SrCa ２ Ga ２ O ６ The present inventors have found that SrCa has a structure in which one-third of the Sr sites are substituted with Ba. ２ Ga ２ O ６ A crystal in which one-third of the Sr sites in ２ Ca ６ Ga ６ O １８ The crystal having an oxide matrix composed of SrCa absorbs light in the ultraviolet to visible light range and emits light in the visible to infrared range. ２ Ga ２ O ６ It has been found that the crystal exhibits novel fluorescent properties (red emission on the high wavelength side (emission on the wavelength side longer than 670 nm, emission in a narrow band) and also has excellent absorption in the blue light region of 450 to 500 nm. Therefore, the crystal of the present invention can be suitably applied to, for example, 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, the security field, biosensors, etc. Furthermore, as will be described in detail later, the crystal of the present invention can be suitably applied to, for example, 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, the security field, biosensors, etc. ２ Ca ６ Ga ６ O １８ It is sufficient that the crystal has an oxide matrix composed of the above, and it may contain elements different from the elements that compose the oxide matrix. The properties of the crystal can be suitably adjusted by the type and content of such elements.

[0076] As described above, the crystal of the present invention is BaSr２ Ca ６ Ga ６ O １８ The oxide matrix may contain elements (hereinafter also referred to as "other elements") other than the elements (i.e., Ba, Sr, Ca, Ga, and O) that constitute the oxide matrix. ２ Ca ６ Ga ６ O １８ At least one of the Ba sites, Sr sites, Ca sites, and Ga sites constituting the above structure may have at least a portion of the element constituting the site substituted with another element.

[0077] However, the content of other elements in the crystal 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.

[0078] The crystalline body of the present invention is represented by the following formula (2): BaSr ２ Ca ６ (Ga （１－ｘ） M ｘ ) ６ O １８ (2) (In formula (2), M is one or more elements selected from the group consisting of Mn, Cr, Fe, Ti, Bi, V, and rare earth elements, and satisfies 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. Since the crystalline body of the present invention is an oxide represented by formula (2), it becomes a crystalline body that emits light in the visible to infrared region. In particular, it has a novel crystalline structure that differs from conventional crystalline bodies, and exhibits fluorescent properties that have not been obtained with compounds of known crystalline structures, such as red emission at a longer wavelength (emission at a wavelength longer than 670 nm) and emission in a narrower band, compared to compounds of conventional crystalline structures. Furthermore, since the crystalline body of the present invention is an oxide represented by formula (2), it is preferable in that it has a strong effect of absorbing light in the range of 300 to 600 nm, preferably 300 to 550 nm, and emitting light in the range of 650 to 900 nm, preferably 650 to 750 nm.

[0079] The crystalline body of the present invention has 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 one or more selected from the group consisting of Mg, Zn, Cu, Co, Ni, Fe, Mn, Ce, and Sn, and A1, A2, and A3 may be the same or different, A4 is one or more selected from the group consisting of Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Al, and M is The oxide is preferably an oxide represented by the formula (3), which is one or more elements selected from the group consisting of Mn, Cr, Fe, Ti, Bi, V, and rare earth elements, and satisfies the following conditions: 0.00≦α≦0.20, 0.00≦β≦0.20, 0.00≦γ≦0.20, 0.00≦δ≦0.20, 0<x≦0.10, and 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. The crystalline body of the present invention is an oxide represented by the formula (3), which emits light in the visible to infrared range. In particular, the crystalline body has a novel crystalline structure that differs from conventional crystalline bodies, and exhibits fluorescent properties not obtainable with compounds of known crystalline structures, such as red emission at longer wavelengths (emission at wavelengths longer than 670 nm) and emission in a narrower band, compared to compounds of conventional crystalline structures. Furthermore, since the crystalline body of the present invention is an oxide represented by formula (3), it is preferable in that it has a strong effect of absorbing light in the range of 300 to 600 nm, preferably 300 to 550 nm, and emitting light in the range of 650 to 900 nm, preferably 650 to 750 nm.

[0080] α is in the range of 0.00≦α≦0.20, preferably 0.00≦α≦0.10, and more preferably 0.00≦α≦0.05. β is in the range of 0.00≦β≦0.20, preferably 0.00≦β≦0.10, and more preferably 0.00≦β≦0.05. γ is in the range of 0.00≦γ≦0.20, preferably 0.00≦γ≦0.10, and more preferably 0.00≦γ≦0.05. δ is in the range of 0.00≦δ≦0.20, preferably 0.00≦δ≦0.10, and more preferably 0.00≦δ≦0.05. x is in the range of 0<x≦0.10, preferably 0.001≦x≦0.09, and more preferably 0.01≦x≦0.07. p is p = 1.00 ± 0.05, preferably p = 1.00 ± 0.01, more preferably p = 1.000 ± 0.001. q is q = 2.00 ± 0.10, preferably q = 2.00 ± 0.02, more preferably q = 2.000 ± 0.002. r is r = 6.00 ± 0.30, preferably r = 6.00 ± 0.06, more preferably r = 6.000 ± 0.006. s is s = 6.00 ± 0.30, preferably s = 6.00 ± 0.06, more preferably s = 6.000 ± 0.006. t is t = 18.00 ± 0.90, preferably t = 18.00 ± 0.18, more preferably t = 18.000 ± 0.018. When the values ​​of α, β, γ, δ, x, p, q, r, s and / or t are within the above ranges, the effect of strong absorption of light in the range of 300 to 600 nm, preferably 300 to 550 nm, and strong emission of light in the range of 650 to 900 nm, preferably 650 to 750 nm, is enhanced, which is preferable.

[0081] The crystal of the present invention has a strong absorption of light in the wavelength range of 300 to 350 nm and 450 to 500 nm, and a strong emission of light in the wavelength range of 650 to 900 nm, preferably 650 to 750 nm, and is therefore a BaSr ２ Ca ６ Ga ６ O １８ It is preferable that a part of Ga constituting the oxide matrix composed of the above is substituted with another element.

[0082] Examples of other elements M substituting Ga at the Ga site include Mn, Cr, Fe, Ti, Bi, V, and rare earth elements. M can be one or more elements selected from Mn, Cr, Fe, Ti, Bi, V, and rare earth elements, but one or more elements selected from the group consisting of Mn, Cr, and rare earth elements are preferred, one or more elements selected from the group consisting of Mn and Cr are more preferred, and Mn is even more preferred. M is an element that becomes the luminescence center when used as a phosphor. This enhances the effect of strong absorption of light in the 300 to 600 nm, preferably 300 to 550 nm, and strong emission of light in the 650 to 900 nm, preferably 650 to 750 nm.

[0083] In the crystalline form of the present invention, Mn is tetravalent (Mn ４＋ ) or in a divalent (Mn ２＋ ), and may be contained in a tetravalent (Mn ４＋ In the crystal of the present invention, Cr, Bi, Fe, Ti, V and rare earth elements are preferably contained in the Ga site in a trivalent (M ３＋ ) is included.

[0084] The substitution ratio of M at the Ga site is, in mole percent ((moles of M / moles of all elements at the Ga site) × 100) of M relative to all elements at the Ga site, more than 0 mole percent and 10 mole percent or less, preferably 0.1 to 9 mole percent, and more preferably 1 to 7 mole percent. When the substitution ratio of M at the Ga site is within the above range, the effect of strong absorption of light at 300 to 600 nm, preferably 300 to 550 nm, and strong emission of light at 650 to 900 nm, preferably 650 to 750 nm, is enhanced. When there are multiple M, the above number of moles of M is the total number of moles of those multiple M.

[0085] Ga at the Ga site may be substituted with an element A4 other than the above M, as long as the effect of the present invention is not impaired. 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, A4 is a trivalent (A4 ３＋ ) is included.

[0086] The substitution ratio of A4 at the Ga site is 20 mol % or less, preferably 10 mol % or less, and more preferably 5 mol % or less, in terms of the mol % of A4 relative to all elements at the Ga site ((moles of A4 / moles of all elements at the Ga site)×100). When there are multiple A4s, the above number of moles of A4 is the total number of moles of the multiple A4s.

[0087] Ba at the Ba site may be substituted with another element A1 within a range that does not impair the effects of the present invention. Examples of A1 include Mg, Zn, Cu, Co, Ni, Fe, Mn, Ce, and Sn. In the crystal of the present invention, A1 is present at the Ba site in a divalent state (A1 ２＋ ) is included.

[0088] The substitution ratio of Al at the Ba site is 20 mol % or less, preferably 10 mol % or less, and more preferably 5 mol % or less, in terms of the mol % of Al relative to all elements at the Ba site ((moles of Al / moles of all elements at the Ba site) × 100). When there are multiple Al, the above number of moles of Al is the total number of moles of the multiple Al.

[0089] Sr at the Sr site may be substituted with another element A2 within the range that does not impair the effects of the present invention. Examples of A2 include Mg, Zn, Cu, Co, Ni, Fe, Mn, Ce, and Sn. In the crystal of the present invention, A2 is a divalent (A2 ２＋ ) is included.

[0090] The substitution ratio of A2 at the Sr site is 20 mol % or less, preferably 10 mol % or less, and more preferably 5 mol % or less, expressed as the mole percentage of A2 relative to all elements at the Sr site ((number of moles of A2 / number of moles of all elements at the Sr site) × 100). When there are multiple A2s, the above number of moles of A2 is the total number of moles of the multiple A2s.

[0091] Ca at the Ca site may be substituted with another element A3 within the range that does not impair the effects of the present invention. Examples of A3 include Mg, Zn, Cu, Co, Ni, Fe, Mn, Ce, and Sn. In the crystal of the present invention, A3 is a divalent (A2 ２＋) is included.

[0092] The substitution ratio of A3 at the Ca site is 20 mol % or less, preferably 10 mol % or less, and more preferably 5 mol % or less, expressed as the mole percentage of A3 relative to all elements at the Ca site ((number of moles of A3 / number of moles of all elements at the Ca site) × 100). When there are multiple A3s, the number of moles of A3 is the total number of moles of the multiple A3s.

[0093] In the crystal of the present invention, the molar ratio of each site in the entire crystal is preferably "total Ba site elements:total Sr site elements:total Ca site elements:total Ga site elements:total O elements at O ​​sites = 1.00:2.00:6.00:6.00:18.00", but the elements at each site may deviate from the above range as long as the effects of the present invention are not impaired. Preferably, the molar ratio is "total Ba site elements:total Sr site elements:total Ca site elements:total Ga site elements:total O elements at O ​​sites = 1.00±0.05:2.00±0.10:6.00±0.30:6.00±0.30:18.00±0.90", and more preferably "total Ba site elements:total Sr site elements:total Ca site elements:total Ga site elements:total O elements at O ​​sites = 1.00±0.05:2.00±0.10:6.00±0.30:6.00±0.30:18.00±0.90". .01:2.00±0.02:6.00±0.06:6.00±0.06:18.00±0.18", and more preferably "total Ba site elements:total Sr site elements:total Ca site elements:total Ga site elements:total O elements at O ​​sites =1.000±0.001:2.000±0.002:6.000±0.006:6.000±0.006:18.000±0.018".

[0094] The crystal structure of the crystalline substance of the present invention is a Turulight structure series, and has a cubic space group such as F432.

[0095] The crystal of the present invention, having the above-mentioned structure, emits red light having a peak at around 710 nm when irradiated with light of 300 to 600 nm.

[0096] The crystalline substance of the present invention may have a crystalline structure at least in part, and may also contain a portion of amorphous structure.

[0097] However, the proportion of the portion having a crystalline structure in the crystalline substance 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.

[0098] The ratio of the crystalline structure portion to the amorphous structure portion in the crystalline substance of the present invention can be determined by measurement using X-ray diffraction.

[0099] The average particle size of the crystalline body 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. In the present invention, the average particle size is a value obtained by taking photographs of particles using an SEM (scanning electron microscope: JSM-7900F, manufactured by JEOL Ltd.) at an accelerating voltage of 8 kV, measuring the minor axes of 100 arbitrarily selected particles, and calculating the average value. Image analysis is performed using the image analysis and measurement software WinROOF.

[0100] The crystal of the present invention is composed of components that are relatively inexpensive and stably available due to the above-mentioned constitution, and therefore has the potential to be applied to various uses. It is an oxide matrix having a novel structure, i.e., SrCa, which is expected to exhibit new properties. ２ Ga ２ O ６ An oxide matrix composed of BaSr ２ Ca ６ Ga ６ O １８ Furthermore, the crystal of the present invention can provide a crystal having an oxide matrix composed of SrCa. ２ Ga ２ O ６ An oxide matrix composed of BaSr ２ Ca ６ Ga ６ O １８By substituting the elements of the oxide matrix composed of the above with other elements, diversification of applications and improvement of performance can be achieved. The crystal of the present invention is composed of components that are relatively inexpensive and stably available, and can be used as a phosphor with excellent properties. Furthermore, by substituting the elements of the oxide matrix with other elements, the crystal of the present invention can provide a crystal that emits light in the visible to infrared range. In particular, the crystal of the present invention has a novel crystal structure that differs from conventional crystals, and can achieve fluorescent properties not obtained with compounds of known crystal structures, such as red emission at longer wavelengths (emission at wavelengths longer than 670 nm) and emission in a narrower band, compared to compounds of conventional crystal structures. Therefore, the crystal of the present invention can be suitably applied to red phosphors in white LEDs, wavelength conversion materials in silicon solar cells, etc.

[0101] The crystal of the present invention may be used for any purpose, and examples of uses of the crystal of the present invention include ultraviolet absorbers, optical sensors, wavelength conversion materials, optical materials such as phosphors, etc. In particular, the crystal of the present invention exhibits excellent effects as a phosphor.

[0102] Furthermore, the crystal of the present invention can be excited by short-wavelength near-ultraviolet to blue light and emit long-wavelength red to near-infrared light, and therefore can be suitably applied, for example, to wavelength conversion materials for wavelength conversion films for solar cells such as silicon.

[0103] The phosphor can be used, for example, as a plant growth promoting material, a light emitting element for displays, a light emitting element for lighting, a scintillator, etc.

[0104] The ultraviolet absorber can be used as an ultraviolet absorbing material in, for example, ultraviolet absorbing sheets, foundations, lotions, sunscreens, and the like.

[0105] The optical sensor can be used, for example, as a light detection element in a photodetector.

[0106] (2) Manufacturing Method of Crystalline Body Next, the manufacturing method of the crystal of the present invention (the manufacturing method of the crystal of the first embodiment of the present invention and the manufacturing method of the second embodiment of the present invention) will be described. Note that the manufacturing method of the crystal of the second embodiment of the present invention and the crystal of the first embodiment of the present invention are similar except for whether or not a Ba source substance is essential, so below, the differences will be described separately, and the similarities will be described by collectively referring to the manufacturing method of the crystal of the second embodiment of the present invention and the manufacturing method of the crystal of the first embodiment of the present invention as the manufacturing method of the crystal of the present invention. Figure 1 is a flowchart showing an example of the steps of the manufacturing method of the crystal of the present invention.

[0107] The crystalline body of the present invention can be suitably produced, for example, by using a method including a mixing step of mixing a Sr source substance, a Ca source substance, and a Ga source substance as raw materials (first embodiment) or at least a Ba source substance, a Sr source substance, a Ca source substance, and a Ga source substance (second embodiment), and a heat treatment step of heat treating the mixture obtained by the mixing step.

[0108] This makes it possible to suitably produce a crystal that is made of components that are relatively inexpensive and stably available, and that can be used as a phosphor with excellent properties.

[0109] Each step will be described below. (2-1) Mixing Step In the mixing step, in the first embodiment, a Sr source substance, a Ca source substance, and a Ga source substance are mixed together, and in the second embodiment, at least a Ba source substance, a Sr source substance, a Ca source substance, and a Ga source substance are mixed together to obtain a raw material mixture.

[0110] Furthermore, in the mixing step, in the first embodiment, a raw material other than the Sr source material, the Ca source material, and the Ga source material (i.e., a raw material of the other element source) may be further used, and in the second embodiment, a raw material other than the Ba source material, the Sr source material, the Ca source material, and the Ga source material (i.e., a raw material of the other element source) may be further used, so as to correspond to the composition of the crystal to be produced.

[0111] The timing of mixing each component in the mixing step is not particularly limited. For example, all raw materials may be mixed at once, or specific types of raw material components may be mixed and then other raw material components may be further mixed.

[0112] As the Sr source, Ca source, Ga source, and Ba source, any compound containing Sr, Ca, Ga, and Ba can be used, respectively. For example, oxides, carbonates, hydroxides, etc. of these elements can be preferably used. Among these, it is preferable to use at least one of a metal carbonate and a metal oxide. This allows the reaction in the subsequent heat treatment step to proceed smoothly.

[0113] These compounds may be used in the form of hydrates. In the following description of preferred compounds, the water of hydration of the hydrates will be omitted.

[0114] Examples of the Sr source include strontium oxide (SrO) and strontium carbonate (SrCO ３ ), strontium hydroxide (Sr(OH) ２ ) etc.

[0115] Examples of the Ca source include calcium oxide (CaO) and calcium carbonate (CaCO ３ ), calcium hydroxide (Ca(OH) ２ ) etc.

[0116] The Ga source may be, for example, gallium oxide (Ga ２ O ３ ), gallium carbonate (Ga ２ (CO ３ ) ３ ), gallium hydroxide (Ga(OH) ３ ) etc.

[0117] Examples of the Ba source include barium oxide (BaO) and barium carbonate (BaCO ３ ), barium hydroxide (Ba(OH) ２ ) etc.

[0118] Examples of the Mn source as the other element source include manganese oxide (MnO, Mn ３ O ４ , Mn ２O ３ , MnO ２ , MnO ３ , Mn ２ O ７ ), manganese carbonate (MnCO ３ ), manganese hydroxide (Mn(OH) ２ ) etc.

[0119] Examples of the Cr source as the other element source include chromium oxide (CrO, Cr ２ O ３ , CrO ２ , CrO ３ ), chromium carbonate (Cr ２ (CO ３ ) ３ ), chromium hydroxide (Cr(OH) ２ , Cr(OH) ３ ) etc.

[0120] Examples of the Bi source as the other element source include bismuth oxide (Bi ２ O ３ ), bismuth carbonate (Bi ２ (CO ３ ) ３ ), bismuth hydroxide (Bi(OH) ３ ) etc.

[0121] As the rare earth element source as the other element source, for example, oxides, carbonates, hydroxides, etc. of rare earth elements can be used.

[0122] More specifically, when the rare earth element is, for example, Sc, the Sc source, which is the rare earth element source, is, for example, scandium oxide (Sc ２ O ３ ), scandium carbonate (Sc ２ (CO ３ ) ３ ), scandium hydroxide (Sc(OH) ３ ) etc.

[0123] When the rare earth element is, for example, Pr, the Pr source, which is the rare earth element source, can be, for example, praseodymium oxide (Pr ６ O １１ , Pr ２ O ３etc.), praseodymium carbonate (Pr ２ (CO ３ ) ３ , Pr(CO ３ ) ２ ), praseodymium hydroxide (Pr(OH) ３ , Pr(OH) ４ ) etc.

[0124] When the rare earth element is, for example, Sm, the Sm source, which is the rare earth element source, can be, for example, samarium oxide (Sm ２ O ３ ), samarium carbonate (SmCO ３ , Sm ２ (CO ３ ) ３ ), samarium hydroxide (Sm(OH) ２ , Sm(OH) ３ ) etc.

[0125] When the rare earth element is, for example, Eu, the Eu source, which is the rare earth element source, can be, for example, europium oxide (Eu ２ O ３ ), europium carbonate (EuCO ３ , Eu ２ (CO ３ ) ３ ), europium hydroxide (Eu(OH) ２ ) etc.

[0126] When the rare earth element is, for example, Tb, the Tb source, which is the rare earth element source, can be, for example, terbium oxide (Tb ２ O ３ , Tb ４ O ７ ), terbium carbonate (Tb ２ (CO ３ ) ３ , Tb(CO ３ ) ２ ), terbium hydroxide (Tb(OH) ３ , Tb(OH) ４ ) etc.

[0127] When the rare earth element is, for example, Tm, the Tm source, which is the rare earth element source, can be, for example, thulium oxide (Tm２ O ３ ), thulium carbonate (TmCO ３ , Tm ２ (CO ３ ) ３ ), thulium hydroxide (Tm(OH) ２ , Tm(OH) ３ ) etc.

[0128] In the mixing step, the Sr source, Ca source, Ga source, and Ba source (and, if necessary, the other element sources) are mixed in a predetermined ratio, for example, a stoichiometric ratio, to prepare a raw material mixture.

[0129] The raw material mixture may be mixed by either dry mixing or wet mixing, but wet mixing is preferred from the viewpoint of being able to mix the raw materials more uniformly.

[0130] The solvent used in the wet mixing is, for example, an organic solvent such as methanol, acetone, benzene, or carbon tetrachloride.

[0131] The mixing method may include, for example, a stationary mixer such as a stirrer, a spiral mixer, a ribbon mixer, or a fluidizing mixer; a rotary mixer such as a cylindrical mixer or a twin cylindrical mixer; a wet grinder such as a sand mill, a ball mill, a bead mill, a colloid mill, or a sand grinder mill; a shaker such as a paint shaker; or a disperser such as an ultrasonic disperser.

[0132] The raw material mixture obtained as described above may be mixed with a flux, for example, prior to the heat treatment step described below.

[0133] This allows the crystal to be obtained in a more suitable crystalline state (for example, composed of a single crystal). ２ etc. can be used.

[0134] It is also possible to obtain a raw material mixture by sequentially adding, for example, a Sr source material, a Ca source material, a Ga source material, a Ba source material, etc. to the flux, and in this case, the same effect as above can be obtained.

[0135] (2-2) Heat Treatment Step In the heat treatment step, the raw material mixture is subjected to heat treatment.

[0136] The heat treatment method in the heat treatment step is not particularly limited as long as it can heat the raw material mixture, and various devices and methods can be used.

[0137] The heat treatment step is preferably performed at 1000° C. or higher and 1600° C. or lower for 3 hours or higher and 10 hours or lower.

[0138] This allows the reaction in the heat treatment step to proceed more smoothly. Also, the crystals can be synthesized by heat treatment at a relatively low temperature, which does not require special equipment and leads to reduced production costs.

[0139] As described above, the heating temperature in the heat treatment step 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 step 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. This allows the reaction in the heat treatment step to proceed more efficiently.

[0140] The atmosphere in the heat treatment step is not particularly limited, and the heat treatment step may be carried out, for example, in the air or in an inert gas atmosphere.

[0141] Examples of the inert gas include argon gas, helium gas, and nitrogen gas.

[0142] The heat treatment step may also be carried out in an atmosphere of a mixed gas of an inert gas and hydrogen gas.

[0143] The proportion of hydrogen gas in the mixed gas can be, for example, 1.0 vol % or more and 10.0 vol % or less.

[0144] The heat treatment process as described above may be carried out in one stage, or in two or more stages under different conditions.

[0145] For example, when the heat treatment step is divided into a first stage and a second stage, the atmosphere may be different between the first stage and the second stage.

[0146] For example, when the heat treatment step is carried out in the first and second stages as described above, the first stage may be carried out in the air, and the second stage may be carried out in a mixed gas atmosphere of an inert gas and hydrogen gas.

[0147] This allows the reactions in the first and second stages of the heat treatment step to proceed more favorably.

[0148] The solid reactant may be pulverized between the first and second stages, which allows the reaction in the second stage of the heat treatment process to proceed more efficiently.

[0149] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these.

[0150] For example, the crystal of the present invention may be SrCa ２ Ga ２ O ６ The crystal of the present invention is not limited to those produced by the above-mentioned production method as long as it has an oxide matrix composed of BaSr ２ Ca ６ Ga ６ O １８ Any material having an oxide matrix composed of the above may be used, and is not limited to those manufactured by the above-mentioned manufacturing method.

[0151] Furthermore, the above-described method for producing a crystal may further include other steps in addition to the steps described above.

[0152] More specifically, for example, in the method for producing a crystalline body, pulverization or classification may be carried out after the mixing step or heat treatment step, as necessary. The pulverization may be either wet pulverization or dry pulverization. In the dry pulverization, a dry pulverizer such as a mortar, roll crusher, atomizer, hammer mill, jet mill, fluid energy mill, or mix muller may be used as necessary.

[0153] Furthermore, for example, the powdered crystal obtained by pulverization may be dispersed in a liquid and then recovered by solid-liquid separation to remove impurities, which can further improve the luminous efficiency of the crystal.

[0154] Solid-liquid separation can be carried out by an industrially commonly used method such as filtration, suction filtration, pressure filtration, centrifugation, decantation, etc. The crystals recovered by solid-liquid separation can be dried using an industrially commonly used device such as a vacuum dryer, a hot air heating dryer, a conical dryer, a rotary evaporator, etc.

[0155] The phosphor of the present invention is characterized in that it comprises a crystal of the above-mentioned 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 some of the elements of the crystal have been substituted with an element that serves as the luminescence center. In other words, the above-mentioned 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 some of the elements of the crystal have been substituted with an element that serves as the luminescence center is a phosphor that is a wavelength conversion material.

[0156] In the phosphor of the present invention, the element that serves as the luminescence center is the above-mentioned M element, i.e., one or more elements selected from the group consisting of Mn, Cr, Fe, Ti, Bi and rare earth elements, preferably one or more elements selected from the group consisting of Mn, Cr and rare earth elements, more preferably one or more elements selected from the group consisting of Mn and Cr, and even more preferably Mn.

[0157] The phosphor of the present invention may be a crystal of the above-mentioned crystal of the present invention (the crystal of the first form of the present invention or the crystal of the second form of the present invention) that is an oxide represented by formula (1), an oxide represented by formula (2), or an oxide represented by formula (3).

[0158] 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.

[0159] The fluorescent material of the present invention is characterized by containing the phosphor of the present invention. That is, the fluorescent material of the present invention consists of the phosphor of the present invention or contains the phosphor of the present invention and, if necessary, contains other components.

[0160] The fluorescent material of the present invention may be a fluorescent material in which the surface of the phosphor of the present invention is coated with a light-transmitting resin, i.e., a fluorescent material containing the phosphor of the present invention and a light-transmitting resin that coats the surface of the phosphor of the present invention.

[0161] The light-transmitting resin has a haze (JIS-K-7136) of 10% or less and a total light transmittance (JIS-K-7361) of 80% or more.

[0162] 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), polytetramethylene terephthalate resin (PTT), and the like.

[0163] When the fluorescent material of the present invention comprises the phosphor of the present invention and a light-transmitting resin that coats the surface of the phosphor of the present invention, if the coating amount of the light-transmitting resin is too thin, the coating performance will not be exhibited, and if it is too thick, the transparency will be impaired. Therefore, the thickness of the light-transmitting resin is preferably 0.1 nm to 10 μm, and more preferably 1 nm to 5 μm.

[0164] Since the fluorescent material of the present invention is a fluorescent material comprising the phosphor of the present invention and a light-transmitting resin that coats the surface of the phosphor of the present invention, when a resin sheet in which the phosphor of the present invention is dispersed is produced, the phosphor of the present invention is easily dispersed in the resin, making it easier to obtain a resin sheet in which the phosphor of the present invention is uniformly dispersed.

[0165] In the fluorescent material of the present invention, the method for coating the surface of the phosphor of the present invention with a light-transmitting resin is not particularly limited, and examples thereof include a method in which the phosphor of the present invention is dispersed in a solvent, a monomer of the 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 to generate a light-transmitting resin on the surface of the phosphor of the present invention, thereby coating the surface of the phosphor of the present invention with the light-transmitting resin.

[0166] The fluorescent material of the present invention may have a core-shell structure, which comprises a core made of the phosphor of the present invention and a shell formed on the surface of the core and made of a material having a lower refractive index than the core. Materials for forming the shell include resin materials and inorganic materials, and from the viewpoint of light transmittance, materials having a lower refractive index than the core are preferably used.

[0167] The fluorescent material of the present invention is a fluorescent material having a core-shell structure consisting of a core made of the phosphor of the present invention and a shell formed on the surface of the core and made of a material with a lower refractive index than the core. This makes it possible to increase the light capture efficiency by using the shell material, and to improve durability by blocking external factors of deterioration with the shell.

[0168] The fluorescent material of the present invention can contain a spreading agent. The spreading agent enhances the wettability, adhesion, spreadability, suspension, etc. of the phosphor of the present invention or the fluorescent material of the present invention, thereby enabling the phosphor of the present invention or the fluorescent material of the present invention to be uniformly adhered. In particular, when the phosphor of the present invention or the fluorescent material of the present invention is used as an agricultural plant growth-promoting material by directly spraying the phosphor of the present invention or the fluorescent material of the present invention on plants to allow it to adhere directly to the leaves, stems, etc. of plants, the phosphor of the present invention or the fluorescent material of the present invention is adhered to the plants by spraying a dispersion of the phosphor of the present invention or the fluorescent material of the present invention in an aqueous solvent on the plants. The spreading agent is used to ensure that the phosphor of the present invention or the fluorescent material of the present invention is uniformly adhered to the surface of the plants at an appropriate density when the dispersion containing the phosphor of the present invention or the fluorescent material of the present invention is sprayed on the plants.

[0169] The spreading agent is not particularly limited as long as it can be used for agricultural purposes, and examples thereof include nonionic surfactants such as polyoxyethylene alkylphenyl ether surfactants, polyoxyethylene alkyl ether surfactants, polyalkylene glycol alkyl ether surfactants, polyoxyethylene fatty acid ester surfactants, polyoxyethylene resin acid ester surfactants, polyoxyethylene hexitane fatty acid ester surfactants, sorbitan fatty acid ester surfactants, and silicone surfactants as active ingredients; anionic surfactants such as naphthylmethanesulfonate surfactants, ligninsulfonate surfactants, and alkylsulfosuccinate surfactants as active ingredients; and cationic surfactants such as tetraalkylammonium salt surfactants. 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 K.K.), and Supply (registered trademark, manufactured by OAT Agrio Co., Ltd.).

[0170] The content of the spreading agent in the fluorescent material of the present invention may be appropriately selected, but is, for example, 0.05 to 10% by mass, preferably 0.1 to 1.0% by mass, based on the phosphor.

[0171] The fluorescent material of the present invention is a fluorescent material comprising the phosphor of the present invention and a light-transmitting resin that coats the surface of the phosphor of the present invention, and when the fluorescent material is used by being dispersed in an aqueous dispersion solvent such as water, alcohol, or a mixed solvent thereof, or 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, and esters such as ethyl acetate, the fluorescent material of the present invention and a spreading agent can be mixed in the dispersion solvent and used.

[0172] The phosphor of the present invention can be dispersed in an aqueous dispersion solvent such as water, alcohol, or a mixture thereof, or in a lipophilic 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, and esters such as ethyl acetate. In this case, the phosphor of the present invention and a spreading agent can be mixed into the dispersion solvent and used.

[0173] When the phosphor or fluorescent material of the present invention is used as an agricultural plant growth material, a method of using the phosphor or fluorescent material of the present invention may include, for example, dispersing the phosphor or fluorescent material of the present invention in an aqueous solvent and spraying the resulting dispersion directly onto plants to adhere the phosphor of the present invention to the surfaces of the leaves, stems, etc. of the plants.

[0174] The use of the phosphor or fluorescent material of the present invention may be any use that requires emission in the visible to infrared light region, and may be any use that requires conversion of light of preferably 300 to 600 nm, preferably 300 to 550 nm, to light of 650 to 900 nm, preferably 650 to 750 nm, and emission of the converted light. Examples of uses of 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 fields, biosensors, and the like.

[0175] The resin sheet of the present invention is characterized by comprising a light-transmitting resin substrate and containing the phosphor of the present invention or the fluorescent material of the present invention.

[0176] The resin sheet of the present invention is made of a light-transmitting resin substrate. That is, the resin sheet of the present invention is a light-transmitting resin formed into a sheet shape. Examples of the light-transmitting resin for the resin sheet of the present invention include the same light-transmitting resin as the light-transmitting resin for the fluorescent material of the present invention.

[0177] The content of the phosphor of the present invention or the 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.

[0178] The resin sheet of the present invention may be one generally called a "sheet" having a thickness of 250 μm or more, one generally called a "sheet" having a thickness of 250 μm or less, or one generally called a "foil." In other words, the thickness of the resin sheet of the present invention is not particularly limited and may be appropriately selected depending on the period of use, the environment of use, the state of use, etc.

[0179] When the resin sheet of the present invention is used as a wavelength conversion sheet for agricultural use, the thickness of the resin sheet of the present invention is preferably 10 to 150 μm, for example.

[0180] The resin sheet of the present invention may contain, as needed, a spreading agent, agricultural materials, pesticides, biostimulants, inorganic substances such as silica, and the like.

[0181] The resin sheet of the present invention is suitably used as an agricultural sheet.

[0182] The present invention will be described in detail below based on specific examples, but the present invention is not limited to these.

[0183] Treatments for which no particular atmospheric or temperature conditions are given were carried out in the air at 25°C.

[0184] (3) Evaluation Methods First, the measurement conditions for the analytical methods used in the evaluations of the following examples are summarized below.

[0185] (3-1) X-ray diffraction Apparatus: MX-Labo (Mac Science Co. Ltd.) X-ray: CuKα (λ=1.54056 Å) Current: 25 mA Voltage: 40 kV

[0186] (3-2) Photoluminescence Apparatus: FP-6500 (JASCO Corporation) Radiation source: 150 W xenon lamp Excitation wavelength: 465 nm Excitation light (λ ｅｘ The intensity of the emitted light when irradiated with light (=435 nm) was measured.

[0187] (4) Production of Crystalline Material (Example 1) First, SrCO as a Sr source ３ powder and CaCO as a Ca source ３ powder and Ga as a Ga source ２ O ３ powder and MnO as a Mn source２ Powders of Sr, Ca, Ga, and Mn were prepared and weighed so that the molar ratio of Sr, Ca, Ga, and Mn was 1.00:2.00:1.94:0.06.

[0188] Next, the raw materials were mixed in an agate mortar to obtain a raw material mixture, in which the raw materials were wet mixed using acetone as a solvent.

[0189] Next, the same mass of flux (SrCl ２ ) was added, heated to 1200°C in the atmosphere, and held at 1200°C for 6 hours to obtain a solid material. The solid material was then allowed to cool to room temperature to obtain a crystalline body.

[0190] The crystalline phase of the crystalline body of Example 1 was identified by X-ray diffraction under the measurement conditions described above.

[0191] The crystal of this example is SrCa ２ (Ga ０．９７ Mn ０．０３ ) ２ O ６ The single crystal had a composition expressed by the formula:

[0192] Detailed crystallographic data obtained by structural analysis of the crystal produced in Example 1 are as follows:

[0193] Crystal system: Cubic system Lattice type: Face-centered cubic lattice Lattice constants: a = 15.475 Å, V = 3705.8.475 Å ３ Space group: F432 z value: 24 R1 factor: 0.0344 wR2 factor: 0.0785

[0194] (Example 2) First, SrCO as a Sr source ３ powder and CaCO as a Ca source ３ powder and Ga as a Ga source ２ O ３ powder and MnO as a Mn source ２ Powders of Sr, Ca, Ga, and Mn were prepared and weighed so that the molar ratio of Sr, Ca, Ga, and Mn was 1.00:2.00:1.94:0.06.

[0195] Next, the raw materials were mixed in an agate mortar to obtain a raw material mixture, in which the raw materials were wet mixed using acetone as a solvent.

[0196] This raw material mixture was placed on a Pt plate, which was then placed in an alumina boat and heat-treated in air at 1200° C. for 6 hours to obtain a solid material.

[0197] The solid material was then allowed to cool to room temperature, and the resulting product was crushed and sieved to obtain a powdery crystalline material.

[0198] The crystal of this example is SrCa ２ (Ga ０．９７ Mn ０．０３ ) ２ O ６ The single crystal had a composition expressed by the formula:

[0199] Examples 3 to 10 Crystals were produced in the same manner as in Example 2, except that the amounts of the Sr source, Ca source, Ga source, and Mn source used were changed.

[0200] (Example 11) In the preparation of the raw material mixture, MnO as a Mn source ２ Instead of powder, Cr as a Cr source ２ O ３ A crystal was produced in the same manner as in Example 2, except that powder was used.

[0201] The proportion of components other than the single crystal contained in the crystals obtained in each of the examples was 1 mass % or less.

[0202] Fig. 2 shows the X-ray diffraction pattern of the crystalline body of Example 1. In the X-ray diffraction pattern shown in Fig. 2, for reference, Sr ３ Ga ２ O ６ Data from ICSD (Inorganic Crystal Structure Database) and SrCa ２ Ga １．８７ Mn ０．１３ O ６ The results of the simulation of the X-ray diffraction pattern are also shown.

[0203] 3 shows the powder X-ray diffraction patterns of the crystalline bodies of Examples 2 to 10. As is clear from FIG. 3, the crystalline bodies of Examples 2 to 10 also exhibited peaks similar to those of Example 1.

[0204] 4 and 5 show the results of photoluminescence measurements of the crystal of Example 1. From FIG. 4, it can be seen that the crystal of Example 1 has excitation in the ultraviolet region and emits green light. From FIG. 5, it can be seen that the crystal of Example 1 has Mn around 700 nm. ４＋ It can also be seen that there is luminescence due to the fluorine-containing compound. Similar results were obtained for Examples 2 to 10.

[0205] 6 shows the relationship between the luminescence intensity when ultraviolet light (365 nm) of a predetermined intensity was irradiated onto the crystals of Examples 2 to 9. From this figure, it can be seen that high luminescence intensity was obtained with the phosphors of Examples 2 to 8, and that particularly high luminescence intensity was obtained with the phosphor of Example 2, in which x in formula (1) is 0.03.

[0206] FIG. 7 shows photographs of the crystal of Example 1 when irradiated with room light, ultraviolet light having a wavelength of 254 nm, and ultraviolet light having a wavelength of 365 nm.

[0207] It exhibited a reddish gray color under room lighting, a green color when irradiated with ultraviolet light having a wavelength of 254 nm, and a red color when irradiated with ultraviolet light having a wavelength of 365 nm. Similar results were obtained for the crystals of Examples 2 to 9.

[0208] 8 shows the powder X-ray diffraction pattern of the crystalline body of Example 11. In the X-ray diffraction pattern shown in FIG. ３ Ga ２ O ６ Data from ICSD (Inorganic Crystal Structure Database) and SrCa ２ Ga １．８７ Mn ０．１３ O ６ The results of the simulation of the X-ray diffraction pattern are also shown.

[0209] 9 shows the results of measuring photoluminescence for the crystal of Example 11. From Fig. 9, it can be seen that the crystal of Example 11 exhibits excitation in the ultraviolet region and emission in the near-infrared region.

[0210] In addition, the oxide matrix (SrCa ２ Ga ２ O ６ Crystals were produced in the same manner as in the above-mentioned Examples, except that some of the elements constituting the crystals (Mn, Cr) were replaced with elements other than Mn and Cr, more specifically, Bi, Pr, Sm, Eu, Tb, and Tm. When these crystals were evaluated in the same manner as above, the crystals containing Bi exhibited a white color under room light, a blue long afterglow when irradiated with ultraviolet light having a wavelength of 254 nm, and a yellow long afterglow when irradiated with ultraviolet light having a wavelength of 365 nm, the crystals containing Pr exhibited a yellow color under room light, and a yellow or blue long afterglow when irradiated with ultraviolet light having a wavelength of 254 nm, and the crystals containing Sm exhibited a yellow or white color under room light, and a red or blue afterglow when irradiated with ultraviolet light having a wavelength of 254 nm. The crystals containing Eu exhibited a yellow or white color under room light, a red color when irradiated with ultraviolet light having a wavelength of 254 nm, and a red color when irradiated with ultraviolet light having a wavelength of 365 nm. The crystals containing Tb exhibited a yellow color under room light, and a green long afterglow when irradiated with ultraviolet light having a wavelength of 254 nm. The crystals containing Tm exhibited a yellow or white color under room light, and a blue long afterglow when irradiated with ultraviolet light having a wavelength of 254 nm.

[0211] Crystals were produced in the same manner as in each of the above-described Examples, except that the treatment temperature in the heat treatment step was variously changed within a range of 1000°C or higher and 1600°C or lower, and the treatment time in the heat treatment step was variously changed within a range of 3 hours or higher and 10 hours or lower. When these crystals were evaluated in the same manner as in the above-described Examples, the same results as in the corresponding Examples were obtained.

[0212] (Example 12) First, BaCO as a Ba source ３ powder and SrCO as a Sr source ３ powder and CaCO as a Ca source３ powder and Ga as a Ga source ２ O ３ powder and MnO as a Mn source ２ Powders of Ba, Sr, Ca, Ga, and Mn were prepared and weighed so that the molar ratio of Ba, Sr, Ca, Ga, and Mn was 1.00:2.00:6.00:5.76:0.24.

[0213] Next, the raw materials were mixed in an agate mortar to obtain a raw material mixture, in which the raw materials were wet mixed using acetone as a solvent.

[0214] Next, the raw material mixture was heated to 1000°C in the atmosphere, held at 1000°C for 4 hours, then taken out and ground in an agate mortar, and then heated to 1200°C and held at 1200°C for 6 hours to obtain BaSr ２ Ca ６ (Ga ０．９６ Mn ０．０４ ) ６ O １８ A powder having the composition shown in the formula:

[0215] Examples 13 to 18 Crystals were produced in the same manner as in Example 12, except that the amounts of the Ba source, Sr source, Ca source, Ga source, and Mn source used were changed.

[0216] The average particle sizes of the crystals of Examples 12 to 18 are shown in Table 1. The average particle sizes were measured by SEM measurement according to the following procedure. <Measurement of average particle size> Using an SEM (scanning electron microscope: JSM-7900F, manufactured by JEOL Ltd.), a photograph of the particles was taken at an acceleration voltage of 8 kV, and 100 particles were randomly selected from the obtained SEM image. The minor axis of each particle was measured, and the average value was calculated to obtain the average particle size. For image analysis, image analysis and measurement software WinROOF was used.

[0217] The crystal obtained in Example 13 was BaSr ２ Ca ６ (Ga ０．９９ Mn ０．０１ ) ６ O １８ The crystal obtained in Example 14 was a powder having a composition represented by the formula: ２ Ca６ (Ga ０．９８ Mn ０．０２ ) ６ O １８ The crystal obtained in Example 15 was a powder having a composition represented by the formula: ２ Ca ６ (Ga ０．９７ Mn ０．０３ ) ６ O １８ The crystal obtained in Example 16 is a powder having a composition represented by the formula: ２ Ca ６ (Ga ０．９５ Mn ０．０５ ) ６ O １８ The crystal obtained in Example 17 was a powder having a composition represented by the formula BaSr ２ Ca ６ (Ga ０．９４ Mn ０．０６ ) ６ O １８ The crystal obtained in Example 18 was a powder having a composition represented by the formula: ２ Ca ６ (Ga ０．９３ Mn ０．０７ ) ６ O １８ The powder had a composition represented by the formula:

[0218] 11 shows the X-ray diffraction patterns of the crystals of Examples 12 to 18. In the X-ray diffraction patterns shown in FIG. ３ Ga ２ O ６ The single crystal X-ray diffraction pattern data of each of the above compounds are also shown. Similar peaks were observed in the crystals of Examples 12 to 18.

[0219] 12 shows the results of measuring photoluminescence for the crystals of Examples 12 to 18. １４ Al １０ Zn ６ O ３５ : Mn ４＋The same measurements were also performed for the other crystals. Table 1 shows the peak-top intensity of the absorption peak near 715 nm, the peak-top intensity of the absorption peak near 350 nm, and the peak-top intensity of the emission peak near 460 nm. From FIG. 12 and Table 1, it can be seen that, among the crystals of Examples 12 to 18, a particularly high emission intensity was obtained with the phosphor of Example 12, in which x in formula (2) is 0.04. Each intensity is expressed as a relative intensity when commercially available YAG is excited at 450 nm and the highest peak in the emission spectrum from 470 to 800 nm is set to 1.

[0220]

[0221] In the table, CZA represents Ca １４ Al １０ Zn ６ O ３５ : Mn ４＋ The wavelength around 350 nm is the absorption intensity at the peak top of the absorption peak around 330 nm, the wavelength around 460 nm is the absorption intensity at the peak top of the absorption peak around 450 nm, and the wavelength around 715 nm is the emission intensity at the peak top of the emission peak around 715 nm.

[0222] Example 19: 120 g of the crystals obtained in Example 15 were dispersed in 250 mL of ethanol. Next, 1 g of 2-methacryloyloxyethyl phosphate was added to the dispersion. The dispersion was then placed in a 500 mL round-bottom flask equipped 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. The reaction solution was then 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 liquid was removed. The resulting fluorescent material was ultrasonically washed three times with 300 mL of ethanol and dried to obtain a light-transmitting resin-coated fluorescent material in which the surface of the crystals was coated with a light-transmitting resin.

[0223] Example 20 The light-transmitting resin-coated fluorescent material obtained in Example 15 was dispersed in water to a solid content concentration of 1.0% by mass to obtain a dispersion.

[0224] Comparative Example 1 Silica particles having an average particle size of 20 μm were dispersed in water to a solid content of 1.0% by mass to obtain a dispersion.

[0225] An experiment on plant growth promotion was conducted using sunny lettuce. The experimental procedure was as follows. Sunny lettuce seeds were placed on a sponge in a hydroponic cultivation system (manufactured by UING) equipped with a white LED. Eight seedlings 7 days after sowing were sprayed 10 times with the dispersion of Example 20. Then, on the 14th day, eight seedlings were sprayed 10 times each, and the plants were harvested 21 days after sowing. The same procedure was performed with the dispersion of Comparative Example 1, and the plants were harvested 21 days after sowing. The fresh weights were then measured immediately after harvest. The fresh weights of the plants sprayed with the light-transmitting resin-coated fluorescent material obtained in Example 19 were 6.9 g, while the fresh weights of the plants sprayed with the silica microparticles of Comparative Example 1 were 6.0 g. The light-transmitting resin-coated fluorescent material obtained in Example 19 exhibited a fresh weight increase of at least 15% by mass compared to the silica microparticles of Comparative Example 1.

[0226] The crystal of the present invention is composed of components that are relatively inexpensive and readily available, and can be used as a phosphor with excellent properties. Therefore, the crystal of the present invention has industrial applicability. Furthermore, the phosphor, fluorescent material, and resin sheet of the present invention are suitable for use in technical fields requiring red light emission by wavelength conversion, particularly in the technical field of plant growth promotion materials for agriculture.

Claims

1. SrCa ２ G ２ O ６ A crystal having an oxide matrix composed of:

2. The crystal according to claim 1, wherein a portion of Ga constituting the oxide matrix is ​​substituted with another element.

3. The crystal according to claim 2, wherein the other elements are one or more selected from 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 said Ga by said other element is 0.10 or less in molar ratio.

5. The crystal according to claim 2, characterized in that the crystal is represented by the following formula (1): SrCa ２ (Ga （１－ｘ） M ｘ ) ２ O ６ (1) (In formula (1), M is one or more elements selected from the group consisting of Mn, Cr, Fe, Ti, Bi, and rare earth elements, and satisfies the relationship 0<x≦0.10.) 6. BaSr ２ Ca ６ G ６ O １８ A crystal having an oxide matrix composed of:

7. The crystal according to claim 6, wherein a portion of Ga constituting said oxide matrix is ​​substituted with another element.

8. The crystal according to claim 7, wherein the other element substituting the Ga is one or more elements selected 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 said Ga by said other element is 0.10 or less in molar ratio.

10. The crystal according to claim 7, characterized in that the crystal is represented by the following formula (2): BaSr ２ Ca ６ (Ga （１－ｘ） M ｘ ) ６ O １８ (2) (In formula (1), M is one or more elements selected from the group consisting of Mn, Cr, Fe, Ti, Bi and rare earth elements, and satisfies the relationship 0<x≦0.10.) 11. A phosphor comprising the crystal according to claim 3 or 8.

12. A fluorescent material, comprising the phosphor according to claim 11, the surface of which is coated with a light-transmitting resin.

13. A resin sheet comprising a light-transmitting resin substrate and containing the phosphor according to claim 11.

Images