JP2008248052A - Stress-induced light-emitting material for emitting ultraviolet ray, its manufacturing method, and its utilization - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stress-induced light-emitting material showing the excellent light emitting characteristics, to be produced at a baking temperature lower than that of the conventional stress-induced light-emitting material, its manufacturing method, and its utilization, and to provide a stress-induced light emitting material showing high luminance light emitting characteristics of a wavelength shorter than 350 nm, its manufacturing method, and its utilization. <P>SOLUTION: The material has a structure represented by general formula MN(PO<SB>3</SB>)<SB>4</SB>, (wherein M is a monovalent metal ion and N is a trivalent metal ion) as the base structure, with at least a part of M or N in the general formula substituted by at least either one of a rare earth ion and a group III metal ion. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a stress-stimulated luminescent material, a method for producing the same, and use thereof, and in particular, a stress-stimulated luminescent material that can be produced at a firing temperature lower than that of a conventional stress-stimulated luminescent material and exhibits excellent luminescent properties. The present invention relates to the manufacturing method and use thereof.

  Conventionally, a phenomenon of emitting visible light (so-called fluorescence phenomenon) by receiving various stimuli (external stimuli) from the outside is known. Substances exhibiting such a fluorescent phenomenon are called phosphors and are used in various fields such as lamps, illumination lamps, various displays such as cathode ray tubes and plasma display panels, and pigments.

  In addition, as external stimuli, many substances (luminous substances) that exhibit a luminescence phenomenon by ultraviolet rays, electron beams, X-rays, radiation, electric fields, or chemical reactions are known. In recent years, the present inventors have found a stress-stimulated luminescent material that emits light by strain generated by applying mechanical external force such as friction, shearing force, impact force, vibration, etc. We are developing.

  Specifically, the present inventors have (1) a stress luminescent material having a spinel structure, a corundum structure, or a β-alumina structure (see Patent Document 1), and (2) a silicate stress luminescent material (Patent Document). (See 2 and 3), (3) Defect-controlled aluminate high-intensity stress illuminant (see Patent Document 4), (4) Composite material containing epoxy resin and test made with coating film of composite material Method of visualizing and evaluating stress distribution by applying mechanical force such as compression, tension, friction and torsion to a piece (see Patent Documents 4 and 5), (5) Wurtzite structure and sphalerite A high-luminance mechanoluminescence material (see Patent Document 6), which has a structure that coexists with a mold structure and is composed mainly of oxides, sulfides, selenides, and tellurides, has been developed. Furthermore, the present inventors recently developed an alumina silicate high intensity stress illuminant and an alumina silicate high intensity stress ultraviolet illuminant (see Patent Document 7).

Each of the stress-stimulated luminescent materials disclosed in Patent Documents 1 to 4, 6, and 7 can emit light repeatedly semipermanently with a luminance that can be confirmed with the naked eye. Moreover, these stress light-emitting bodies can be used for measuring a stress distribution in a structure including the stress light-emitting body. Examples of the stress distribution measuring method include (1) a stress or stress distribution measuring method using a stress illuminant, (2) a stress distribution measuring system (see Patent Document 8), and (3) mechanical. For example, a light emitting head that directly converts an external force into an optical signal and transmits it, and (4) a remote switch system using the light emitting head (see Patent Document 9).
JP 2000-119647 A (released on April 25, 2000) JP 2000-313878 (released on November 14, 2000) JP 2003-165993 (published June 10, 2003) JP 2001-49251 A (published on February 20, 2001) JP 2003-292949 A (published on October 15, 2003) JP-A-2004-43656 (Released on February 12, 2004) International Publication WO2006 / 109704 A1 (released October 19, 2006) JP 2001-215157 A (published August 10, 2001) JP-A-2004-77396 (published on March 11, 2004)

  As disclosed in Patent Documents 1 to 4, 6, and 7, many stress-stimulated luminescent materials have been developed. The luminescent color of stress-stimulated luminescent materials covers all the wavelength ranges used in the industry. Not reached. For example, Patent Document 7 discloses a stress-stimulated luminescent material that emits ultraviolet light having a wavelength of 350 to 400 nm, but no stress-stimulated luminescent material that emits ultraviolet light having a wavelength shorter than 350 nm has been found so far. In addition, the stress-stimulated luminescent material is obtained by mixing raw materials and firing. However, since the firing temperature is a high temperature of 1000 ° C. or higher, much energy is required for production. Therefore, development of a stress-stimulated luminescent material that emits light in an unprecedented wavelength region and a stress-stimulated luminescent material that can be manufactured at a lower firing temperature than conventional stress-stimulated luminescent materials are required.

  The present invention has been made in view of the above problems, and a first object thereof is a stress-stimulated luminescent material which can be produced at a firing temperature lower than that of a conventional stress-stimulated luminescent material and exhibits excellent luminescent properties. It is in providing the manufacturing method and its utilization. In addition, the second object is that the production at a firing temperature lower than that of a conventional stress-stimulated luminescent material is possible, and the stress-stimulated luminescent material that emits ultraviolet light having a wavelength shorter than 350 nm, its production method, and its To provide usage.

As a result of intensive studies in view of the above problems, the present inventors have expressed the general formula MN (PO ₃ ) ₄ (wherein M is a monovalent metal ion and N is a trivalent metal ion). A stress-stimulated luminescent material that exhibits high-luminance luminescence characteristics at a lower firing temperature than conventional by replacing a part of M or N in the above general formula with a rare earth ion or a group III metal ion as a base structure. Found that it can be manufactured. Furthermore, it has been found that by using a specific metal ion as the rare earth ion or group III metal ion, ultraviolet light having a wavelength shorter than 350 nm is emitted. Based on these unique findings, the present inventors have completed the present invention. That is, the present invention includes the following industrially useful inventions.

(1) The following general formula (a)
MN (PO ₃ ) ₄ (a)
(In the formula, M is a monovalent metal ion and N is a trivalent metal ion.)
A stress-luminescent material characterized in that the structure represented by the formula is a matrix structure, and a part of M or N in the general formula (a) is substituted with at least one of a rare earth ion or a group III metal ion.

  (2) The stress-stimulated luminescent material according to (1), wherein M in the general formula (a) is an alkali metal ion, and N is a rare earth ion, La ion, or Y ion.

  (3) In the general formula (a), M is Na ion, K ion, Rb ion, or Cs ion, and N is Ce ion, Pr ion, Nd ion, Pm ion, Sm ion, Eu ion, Gd ion. Tb ion, Dy ion, Ho ion, Er ion, Tm ion, Yb ion, The stress luminescent material as described in (1) characterized by the above-mentioned.

  (4) The stress-stimulated luminescent material according to (1), wherein M in the general formula (a) is Na ion and N is La ion.

  (5) Rare earth ions substituted for a part of M or N in the general formula (a) are Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and A rare earth ion selected from the group consisting of Yb, wherein the group III metal ion substituted with a part of M or N in the general formula (a) is a Tl ion (1) The stress-stimulated luminescent material according to any one of to (4).

  (6) The rare earth ion substituted for a part of M or N in the general formula (a) is a rare earth ion selected from the group consisting of Eu, Dy, Ce, and Tb. The stress-stimulated luminescent material according to any one of (1) to (4), wherein the group III metal ion substituted with a part of M or N in a) is a Tl ion.

  (7) The rare earth ion substituted with a part of M or N in the general formula (a) is a Ce ion, and the Group III metal substituted with a part of M or N in the general formula (a) The stress luminescent material according to any one of (1) to (4), wherein the ions are Tl ions.

  (8) The content of rare earth ions and group III metal ions substituted for a part of M or N in the general formula (a) is 0.1 to 20 mol%, (1) to The stress-stimulated luminescent material according to any one of (7).

  (9) The stress-stimulated luminescent material according to any one of (1) to (8), which emits ultraviolet rays.

  (10) The stress-stimulated luminescent material according to any one of (1) to (8), which emits ultraviolet rays having a wavelength shorter than 350 nm.

(11) The composition formula is the following general formula (b)
Na _1-x Q _x La (PO ₃ ) ₄ (b)
(In the formula, Q is Ce ion or Tl ion, and x is a number satisfying 0.01 ≦ x ≦ 0.2.)
The stress-stimulated luminescent material according to (1), which is represented by:

  (12) A production method for producing the stress-stimulated luminescent material according to any one of (1) to (11), wherein raw materials are mixed and fired at 200 to 350 ° C. for 1 to 4 hours in the air. Furthermore, the manufacturing method of the stress light-emitting material characterized by baking at 400-600 degreeC in air | atmosphere for 10 to 40 hours.

  (13) A stress luminescent material formed by molding the stress luminescent material according to any one of (1) to (11).

  (14) A stress-stimulated luminescent material obtained by mixing the stress-stimulated luminescent material according to any one of (1) to (11) and a polymer material.

  (15) The stress-stimulated luminescent material as described in (13) or (14), wherein the stress-stimulated luminescent material is used by one-dimensional dispersion.

  (16) The stress-stimulated luminescent material according to (13) or (14), wherein the stress-stimulated luminescent material is two-dimensionally distributed.

  (17) The stress-stimulated luminescent material according to (13) or (14), wherein the stress-stimulated luminescent material is distributed three-dimensionally.

As described above, the stress-stimulated luminescent material according to the present invention is represented by the general formula MN (PO ₃ ) ₄ (wherein M is a monovalent metal ion and N is a trivalent metal ion). And a part of M or N in the above general formula is substituted with at least one of rare earth ions or Group III metal ions. The parent structure is a crystal structure in which distortion is likely to occur. Therefore, there is an effect that the matrix structure is distorted by a load of a mechanical external force and can emit light with high luminance. In addition, since the stress-stimulated luminescent material according to the present invention can be manufactured by firing at a temperature lower than 1000 ° C., there is an effect that energy consumption at the time of manufacturing can be reduced.

  An embodiment according to the present invention will be described below with reference to FIGS. 1 to 3, but the present invention is not limited to this.

<I. Stress Luminescent Material>
The stress-stimulated luminescent material according to the present invention has the general formula (a)
MN (PO ₃ ) ₄ (a)
(In the formula, M is a monovalent metal ion and N is a trivalent metal ion.)
And a structure in which a part of M or N in the general formula (a) is substituted with at least one of a rare earth ion or a group III metal ion. In the matrix structure, the three-dimensional crystal structure is likely to be distorted by a mechanical external force load. Therefore, according to the above configuration, the three-dimensional crystal structure (space) of the base structure is distorted by a mechanical external force load and exhibits strong light emission. In this specification, “stress light emission” is intended to emit light by deformation due to mechanical external force such as frictional force, shearing force, pressure, and tension.

  Furthermore, the stress-stimulated luminescent material according to the present invention can be produced at a firing temperature lower than that of a conventional stress-stimulated luminescent material, specifically, a firing temperature lower than 1000 ° C. Therefore, it can be manufactured with less energy. In addition, since the method for producing the stress-stimulated luminescent material according to the present invention will be described later, detailed description thereof is omitted here.

  Moreover, the crystal structure of the host structure of the stress-stimulated luminescent material according to the present invention can be distorted by other than mechanical external force. Specifically, the matrix structure can be distorted by various energies such as an electric field. Therefore, the stress-stimulated luminescent material according to the present invention can emit light in a light-emitting mode other than stress-stimulated light emission. That is, the stress-stimulated luminescent material according to the present invention only needs to exhibit at least stress luminescence, and may exhibit luminescence by other luminescence modes in addition to stress luminescence.

  In the stress-stimulated luminescent material according to the present invention, the rare earth ions and the III metal ions function as luminescent centers. In the luminescent material, the luminescent color of the luminescent material changes depending on the type of luminescent center. In other words, in the stress-stimulated luminescent material according to the present invention, the luminescent color can be changed by changing the kind of the rare earth ions and the group III metal ions. The rare earth ions and the group III metal ions may be any one that can be a luminescent center. Specifically, for example, as rare earth ions, europium (Eu), dipsyrosium (Dy), lanthanum (La), gadolinium (Gd ), Cerium (Ce), samarium (Sm), yttrium (Y), neodymium (Nd), terbium (Tb), praseodymium (Pr), erbium (Er), thulium (Tm), ytterbium (Yb), scandium (Sc) ), Promethium (Pm), holmium (Ho), and lutetium (Lu).

  Examples of the group III metal ion include group III metal ions such as aluminum (Al), gallium (Ga), indium (In), and thallium (Tl).

The stress-stimulated luminescent material according to the present invention may contain the rare earth ions and group III metal ions exemplified above alone or in combination. Further, among those exemplified above, rare earth ions and / or Tl ions selected from the group consisting of Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb. Preferably, it contains a rare earth ion or a group III metal ion selected from the group consisting of Eu ²⁺ , Tb ³⁺ , Dy ³⁺ , Ce ³⁺ , and Tl ⁺ . By containing these rare earth ions or group III metal ions, a high intensity stress luminescent material can be obtained.

Furthermore, it is preferable that Ce ³⁺ or Tl ⁺ is included among the rare earth ions and group III metal ions exemplified above. As disclosed in Patent Documents 1 to 4, 6, and 7, stress-stimulated luminescent materials that exhibit strong light emission in a wavelength region of 350 nm or more (blue to red wavelength region) have been known. A stress-stimulated luminescent material that emits ultraviolet rays having a short emission wavelength region, that is, a wavelength shorter than 350 nm has not been obtained. However, in the stress-stimulated luminescent material according to the present invention, for example, if Ce ³⁺ or Tl ⁺ is selected as the luminescent central metal ion, a high-luminance stress-stimulated luminescent material that emits ultraviolet light having a wavelength shorter than 350 nm can be realized. it can. That is, according to the present invention, a stress luminescent material that emits ultraviolet rays, preferably ultraviolet rays having a wavelength shorter than 350 nm, is realized by replacing a part of the base structure with a specific rare earth ion or group III metal ion. can do. In the present specification, “ultraviolet light” intends radiation in a wavelength range of 200 to 400 nm, preferably in a wavelength range of 200 to 350 nm.

  Further, the specific values of the rare earth ions and group III metal ions are not particularly limited, but the contents generally affect the light emission characteristics of the light emitting material. Therefore, the content may be set within a range in which desired light emission characteristics can be obtained. Specifically, it is preferable to set the contents of the rare earth ions and the group III metal ions within a range in which the three-dimensional structure of the host structure is maintained. More specifically, the content is preferably 0.1 to 20 mol%, more preferably 1 to 15 mol%, and particularly preferably 1 to 10 mol%. In addition, when the said content is less than 0.1 mol%, efficient light emission cannot be obtained, and when it exceeds 20 mol%, there exists a tendency for a host structure to be disturb | confused and for luminous efficiency to fall.

That is, specifically, the stress-stimulated luminescent material according to the present invention has, for example, a composition formula represented by the following general formulas (b) to (e).
M _1-x Q _x N (PO ₃ ) ₄ (b)
M _1-xy Q _x R _y N (PO ₃ ) ₄ (c)
MQ _x N _1-x (PO ₃ ) ₄ (d)
MQ _x R _y N _1-xy (PO ₃ ) ₄ (e)
Wherein M is a monovalent metal ion, N is a trivalent metal ion, Q and R are each independently a rare earth ion or a group III metal ion, and x is 0.01 ≦ x ≦ 0.2 is a number satisfying 0.20, and y is a number satisfying 0.01 ≦ y ≦ 0.20.)
It can be represented by either

  In the general formulas (a) to (e), M may be a monovalent metal ion, and specific examples include alkali metal ions. Among these, Na ions, K ions, Rb ions, or Cs ions are preferable. In the general formulas (a) to (e), N may be a trivalent metal ion, and specific examples include rare earth ions. Among them, Ce ion, Pr ion, Nd ion, Pm ion, Sm ion, Eu ion, Gd ion, Tb ion, Dy ion, Ho ion, Er ion, Tm ion, Yb ion, La ion, or Y ion Is preferred. More specifically, as a preferable combination of (M, N), (Na, La), (K, Yb), (K, Ce), (K, Gd), (K, Bi), (Na, Er) ), (Na, Nd), (Na, Bi), (Na, Gd), (Cs, Nd), (Cs, Er), (Cs, Gd), (Cs, Er), (Rb, Nd), (Rb, Ho), (Rb, Tm), (Ag, Nd), and (Ag, La). According to the said structure, the base structure of the stress light-emitting material concerning this invention can be made into the structure which is easy to be distorted by stress.

As a preferred embodiment of the present invention, (M, N) = (Na, La), that is, a stress-stimulated luminescent material having NaLa (PO ₃ ) ₄ as a base structure can be mentioned. Hereinafter, as an embodiment of the stress-stimulated luminescent material according to the present invention, a stress-stimulated luminescent material having NaLa (PO ₃ ) ₄ as a base structure will be described in more detail.

The crystal structure of NaLa (PO ₃ ) ₄ takes the space group P2 ₁ / n (J. Zhu, W.-D. Cheng, D.-S. Wu, J. Solide State Sci., 6 (2006) 597. See). More specifically, as shown in FIG. 1, it is formed of a three-dimensional frame network structure in which a LaO ₈ polyhedron and [(PO ₃ ) ₄ ] ^4- are connected by La-OP. Na ⁺ is located in the gap of this framework. Na ⁺ is coordinated to six oxygen atoms having a Na—O bond distance of 2.416 to 2.756 Å. On the other hand, as shown in FIG. 3, La ³⁺ is surrounded by eight oxygen atoms, and the La—O bond distance is 2.441 to 2.558 Å. That is, in NaLa (PO ₃ ) ₄ , the Na site is larger than the La site.

Further, the wave ^- like coupling of [(PO ₃ ) ₄ ] ^4- is composed of (PO ₃ ) ₄ formed by the vertex sharing of the PO ₄ tetrahedron along the a-axis, as shown in FIG. In the PO ₄ tetrahedron, the PO distance fluctuates in the range of 1.475 to 1.492 mm, and the PO bond is broken at the closest distance, whereas at the longest distance, the PO bond is broken. -O is bonded. The angle of O—P—O is 99.4 to 119.6 °, and the angle of P—O—P of [(PO ₃ ) ₄ ] ⁴⁻ is 131.5 to 139.4 °.

In NaLa (PO ₃ ) ₄ , as described above, the Na site is larger than the La site. Therefore, in the stress-stimulated luminescent material according to the present embodiment, it is preferable that a part of Na of the base structure NaLa (PO ₃ ) ₄ is substituted with rare earth ions or group III metal ions. However, a part of La may be substituted with rare earth ions or Group III metal ions. The rare earth ions or Group III metal ions and their contents are as described above.

  Since the stress-stimulated luminescent material according to the present invention has the above-described configuration, it can exhibit high-luminance luminescence by applying a mechanical external force. The stress-stimulated luminescent material according to the present invention can be manufactured by firing at a lower temperature than conventional stress-stimulated luminescent materials. Therefore, energy consumption required for manufacturing can be reduced. Furthermore, since the stress-stimulated luminescent material according to the present invention has the above-described host structure, it is possible to provide a stress-stimulated luminescent material having a wavelength region of 300 to 600 nm by selecting a specific metal ion as the luminescent center. That is, it is possible to provide a stress-stimulated luminescent material that emits ultraviolet light having a wavelength shorter than 350 nm, which is not conventional. Therefore, the stress-stimulated luminescent material according to the present invention can be widely used as a luminescent material. In particular, a stress-stimulated luminescent material that emits ultraviolet rays not only uses the luminescent color (blue) but also can use ultraviolet energy as excitation energy, for example. Therefore, in addition to using as a light emitting material exhibiting a specific light emission color, it can be used for a wider range of applications. Furthermore, since the matrix structure of the stress-stimulated luminescent material according to the present invention is a phosphate, it is unlikely to cause environmental pollution. Therefore, for example, it can be suitably used for applications used in a natural environment.

<II. Method for producing stress luminescent material>
The method for producing a stress-stimulated luminescent material according to the present invention (hereinafter also simply referred to as “manufacturing method according to the present invention”) is a method for producing the above-described stress-stimulated luminescent material according to the present invention. Specifically, it is a method for producing a stress-stimulated luminescent material according to the present invention by a solid-phase reaction method, and more specifically, the raw materials are weighed and fired so as to have the desired composition of the stress-stimulated luminescent material. This is a method for producing a stress-stimulated luminescent material. Generally, in the production of stress-stimulated luminescent materials, the firing conditions are factors that greatly affect the physical properties of the obtained stress-stimulated luminescent materials. More specifically, when the raw material is amorphized (vitrified) during firing, a desired base structure is not formed. In other words, the crystal structure is less likely to be distorted by a mechanical external force. With such a structure, even if the composition is the same, the crystal structure is not distorted due to a mechanical external force, so that it does not exhibit stress luminescence. That is, in order for the obtained material to exhibit stress luminescence, it is premised that a base structure having a crystal structure that is likely to be distorted by mechanical external force is formed by firing. Therefore, in the manufacturing method according to the present invention, it is necessary to perform firing under the condition that a base structure having a crystal structure that is likely to be distorted by a mechanical external force is formed. For example, if the temperature is rapidly raised or lowered during firing, the desired crystallinity tends to be difficult to obtain. For this reason, in the method for producing a stress-stimulated luminescent material according to the present invention, it is preferable that the temperature is raised and lowered slowly (stepwise) during firing. More specifically, it is preferable to raise and lower the firing temperature stepwise at a rate of 1 to 10 ° C./min.

  The firing temperature also greatly affects the physical properties of the stress luminescent material. Accordingly, the firing temperature is preferably set according to the composition of the stress-stimulated luminescent material so that a host structure having a desired crystal structure is formed. Specifically, the temperature is preferably 400 to 600 ° C, more preferably 450 to 600 ° C, and still more preferably 600 ° C. According to the firing temperature, it is possible to form a base structure having a crystal structure in which distortion is likely to occur due to mechanical external force. Therefore, a high-luminance stress luminescent material can be manufactured. Moreover, the firing temperature of the conventional stress-stimulated luminescent material is a high temperature of 1000 ° C. or higher. However, the production method according to the present invention can produce the stress-stimulated luminescent material at a lower firing temperature. Therefore, manufacturing equipment cost and energy consumption required for manufacturing can be reduced. In addition, it is preferable to perform baking in air | atmosphere.

  Further, the firing time is appropriately changed according to the composition of the stress-stimulated luminescent material and the firing temperature, and is not particularly limited, but is generally set within a range of 10 to 40 hours. Good.

  Furthermore, in the manufacturing method according to the present invention, it is preferable to perform preliminary firing before firing at the firing temperature. The pre-baking temperature is preferably 150 to 400 ° C, and preferably 200 to 350 ° C. Furthermore, it is preferable that the temporary baking time is 1 to 4 hours. By performing such preliminary firing, the yield of the stress-stimulated luminescent material obtained can be increased. That is, the production efficiency of the stress-stimulated luminescent material can be improved. In addition, it is preferable to perform temporary baking also in air | atmosphere.

  In the production method according to the present invention, the raw material, that is, the raw material of the stress luminescent material according to the present invention is not particularly limited as long as it becomes the stress luminescent material according to the present invention by firing. Specifically, for example, an alkali metal salt, a rare earth salt, a phosphate, and a salt of a metal serving as a light emission center may be used as a raw material in accordance with the composition of the stress luminescent material according to the present invention. Any of the alkali metal salts, rare earth salts, phosphates, and salts of the metal serving as the emission center may be inorganic salts or organic salts. Examples of the inorganic salt include oxides, halides (for example, chloride), hydroxides, ammonium salts, carbonates, phosphates, sulfates, nitrates, and the like. Examples of the organic salt include acetates and alcoholates. The amount of the raw material may be a proportion corresponding to the constituent atomic ratio according to the composition of the stress-stimulated luminescent material to be manufactured. In order to easily distort the matrix structure, the lattice defects of alkali metal ions are used. It is advantageous to form. Therefore, it is preferable to reduce the alkali metal composition within the range of 0.1 to 20 mol% rather than the chemical composition stoichiometry of the base structure. Further, the raw material may contain a fluxing agent such as boric acid or ammonium chloride.

  In the production method according to the present invention, the raw materials are preferably wet-mixed using ethanol or the like after weighing a desired amount. Then, it is preferable to perform temporary baking and baking on the conditions mentioned above.

<III. Stress light emitter>
The stress-stimulated luminescent material according to the present invention exhibits high luminance light emission. In addition, as one embodiment, strong emission of ultraviolet rays having a wavelength shorter than 350 nm, which has not been obtained conventionally, is shown. Therefore, the stress-stimulated luminescent material according to the present invention can be used in various industrial fields by utilizing such luminescent characteristics. Although the usage form of the stress-stimulated luminescent material according to the present invention is not particularly limited, for example, it can be used as a stress-stimulated luminescent material formed by molding the stress-stimulated luminescent material. Moreover, it can be used as a stress luminescent material obtained by mixing the stress luminescent material according to the present invention and a polymer material. Therefore, the present invention includes such a stress luminescent material. Hereinafter, the stress-stimulated luminescent material according to the present invention will be described.

  The stress-stimulated luminescent material according to the present invention only needs to contain the stress-stimulated luminescent material according to the present invention, and other specific configurations are not particularly limited. For example, it can be mixed with other inorganic materials or organic materials to form a stress luminescent material made of a composite material. More specifically, for example, a configuration in which a stress light emitting material and a polymer material are mixed and formed into a flat plate shape can be employed. The polymer material mixed with the stress-stimulated luminescent material is not particularly limited, and examples thereof include a resin such as an epoxy resin. The amount of the polymer material to be mixed is not particularly limited. For example, the stress light emitting material may be formed in a flat plate shape and mixed in such an amount that the shape can be maintained. Moreover, the mixing conditions of the polymer material are not particularly limited, and a known method may be used. According to such a configuration, since the composite material includes the stress-stimulated luminescent material according to the present invention, when the composite material is strained by a mechanical external force, the stress-stimulated luminescent material in the composite material is distorted. Occurs. This strain becomes excitation energy, and the composite material emits light.

  As one embodiment, the stress-stimulated luminescent material according to the present invention can be a stress-stimulated luminescent material formed by molding the stress-stimulated luminescent material into fine particles. The method for forming the stress-stimulated luminescent material into fine particles is not particularly limited. For example, a powdered stress luminescent material may be formed into fine particles using a conventionally known method. Of course, at this time, additives necessary for forming the fine particles may be appropriately added. The particle size of the fine particles is not particularly limited, but is preferably 100 μm or less, and more preferably 1 nm to 100 μm. The stress-stimulated luminescent material according to the present embodiment can be used for applications in which fine particles of the stress-stimulated luminescent material are dispersed one-dimensionally in a target system, light is emitted by a mechanical external force, and the light emission is utilized. In this specification, “one-dimensional dispersion” refers to a phenomenon in which a particulate material is dispersed in another uniform material, and “one-dimensional dispersion” refers to a particulate material. (As an example in the present invention, it is intended to disperse the stress-stimulated luminescent particles having a particle size of several nm to 100 μm) in other uniform substances. The stress-stimulated luminescent material according to the present embodiment can also be used as a material for manufacturing a stress-stimulated luminescent material (details will be described later) in which the stress-stimulated luminescent material is distributed two-dimensionally or three-dimensionally.

  The stress-stimulated luminescent material according to the present invention may be a stress-stimulated luminescent material in which the stress-stimulated luminescent material is dispersed two-dimensionally as one embodiment. Examples of the stress-stimulated luminescent material according to this embodiment include an embodiment in which a planar object such as a substrate is coated with the stress-luminescent material according to the present invention and molded into a planar film. The method for producing the stress-stimulated luminescent material according to the present embodiment is not particularly limited. For example, a powdered stress-stimulated luminescent material or a fine-grained stress-stimulated luminescent material (stress luminescent material) is formed into a planar shape such as a substrate. It can manufacture by coating the surface of the target object by a conventionally well-known method. In addition, you may add suitably an additive required in order to form into a film at the time of shaping | molding.

  In addition, the stress-stimulated luminescent material according to the present embodiment includes a compound that can form the host structure of the stress-stimulated luminescent material according to the present invention, such as a nitrate, a halide, an alkoxy compound, and the like, and a compound containing a metal serving as a luminescent center. It can also be produced by applying a coating solution prepared by dissolving in a solvent to the surface of the heat-resistant substrate, followed by baking. The heat-resistant substrate is not particularly limited. Specifically, for example, quartz, silicon, graphite, heat-resistant glass such as quartz glass and Vycor glass, alumina, silicon nitride, silicon carbide, molybdenum silicide, etc. Examples thereof include heat-resistant steels such as ceramics, stainless steel, heat-resistant metals or heat-resistant alloys such as nickel, chromium, titanium, and molybdenum, cermets, cements, and concretes.

  The stress-stimulated luminescent material according to the present embodiment can be used, for example, for light emission by applying a mechanical external force to a film (film) containing a stress-stimulated luminescent material and utilizing the light emission. In addition, as described above, by using the stress-stimulated luminescent material according to the present invention formed into a film, it is possible to realize light emission of a large area with a small amount of the stress-stimulated luminescent material.

  Moreover, the stress light-emitting body concerning this invention can be a stress light-emitting body which the stress light-emitting material concerning this invention is distributed three-dimensionally as one Embodiment. Examples of the stress-stimulated luminescent material according to the present embodiment include an embodiment in which a stress-stimulated luminescent material according to the present invention is coated on a three-dimensional network structure (for example, a three-dimensional structure) and formed into a three-dimensional film shape, Examples include a three-dimensional structure obtained by three-dimensionally molding the stress-stimulated luminescent material according to the invention. The method for producing the stress-stimulated luminescent material according to the present embodiment is not particularly limited. For example, the stress-stimulated luminescent material according to the present invention is three-dimensionally used by using a conventionally known technique such as plating or a mold. It can be manufactured by three-dimensional molding.

  In the stress-stimulated luminescent material according to the embodiment described above, if a stress-stimulated luminescent material exhibiting ultraviolet luminescence characteristics is used as the stress-stimulated luminescent material, ultraviolet light generated by mechanical external force is applied to an object in contact with or close to the stressed luminescent material. Can act physically and / or chemically. Specifically, since ultraviolet rays have a short wavelength, energy is high. For this reason, the ultraviolet-ray obtained by light emission of a stress ultraviolet-ray luminescent material can be used as excitation light. For example, a light emitting material that emits light of a color different from blue, such as red, yellow, and green, and that emits light by ultraviolet light and does not emit light by stress, the stress of the present invention that emits ultraviolet light A composite material (light emitter) is formed by mixing with the light emitting material. When stress is applied to this composite material, only the stress-stimulated luminescent material according to the present invention emits light and emits ultraviolet rays. The emitted ultraviolet light can excite a light emitting material that emits light of a color different from that of blue. According to such a configuration, the light emitters of all colors from blue to red can be made to emit light. As a result, it is possible to realize stress-stimulated illuminants of all luminescent colors.

  Furthermore, since ultraviolet rays have high energy, detection by a detector is easy. Therefore, it is possible to easily detect the light emission intensity of the stress luminescent material and the stress luminescent material that emit ultraviolet rays. Furthermore, ultraviolet rays are less emitted from lighting fixtures such as fluorescent lamps, and have an advantage of less interference even in an illumination environment when measuring the emitted light.

  In addition, the stress-stimulated luminescent material according to the present invention emits light by applying mechanical external force such as frictional force, shearing force, impact force, vibration, wind force, and ultrasonic wave. This emission intensity depends on the nature of the mechanical external force serving as an excitation source, but generally tends to increase as the applied mechanical action force increases. Therefore, by measuring the light emission intensity of the stress light emitter according to the present invention, the mechanical external force applied to the stress light emitter can be measured without contact. That is, according to the stress-stimulated luminescent material according to the present invention, the stress state can be visualized. For this reason, the light-emitting body of the present invention can be applied to all fields for detecting stress, such as a stress detector. The stress-stimulated luminescent material according to the present invention can also be used as a phosphorescent material or a phosphor.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and can be obtained by appropriately combining technical means disclosed in different embodiments. Embodiments are also included in the technical scope of the present invention.

  Although this invention is demonstrated more concretely based on an Example and FIGS. 4-15, this invention is not limited to this. Those skilled in the art can make various changes, modifications, and alterations without departing from the scope of the present invention.

[Production Example 1: Production of NaLa (PO ₃ ) ₄ ]
A solid phase reaction method was used to synthesize NaLa (PO ₃ ) ₄ powder sample. NaCl (99.5%), La ₂ O ₃ , and (NH ₄ ) ₂ HPO ₄ (98.5%) were weighed and wet mixed with ethanol. The obtained mixed powder was heated in air from room temperature to 900 ° C. at a heating rate of 10 ° C./min. As a result of the measurement of TG-DTA, it was found that crystallization started from around 400 ° C. (not shown). However, since it was found that the number of samples became very small after the measurement, it was decided to perform preliminary baking before the main baking. Specifically, after calcining at 350 ° C. for 4 hours in the air, it was calcined at 700 ° C. for 10 hours to produce a NaLa (PO ₃ ) ₄ powder sample. The temperature rising rate was 10 ° C./min.

The obtained NaLa (PO ₃ ) ₄ powder sample was subjected to crystal structure analysis by the method described above. Crystal structure analysis was performed using an XRD pattern obtained by powder X-ray diffraction (XRD) measurement using CuKα rays. As a result, as shown in FIG. 4 (a), it was confirmed that the target frame network structure was formed because it belonged to a monoclinic crystal (space group: P2 ₁ / n).

Further, by using the powder samples obtained NaLa _{(PO 3) 4,} was measured excitation and emission spectra of NaLa _{(PO 3) 4.} The excitation spectrum and emission spectrum were measured at room temperature using a spectrofluorometer (JASCO FP-6600). As a result, as shown in FIG. 5A, in the emission spectrum of NaLa (PO ₃ ) ₄ , emission peaks were observed in the vicinity of 450 nm and 590 nm. This result is reported in NaLa (PO) reported by J. Zhu et al. (See J. Zhu, W.-D. Cheng, D.-S. Wu, J. Solide State Sci., 6 (2006) 597). ₃ ) The emission spectrum of ₄ coincided with the peak position. From this, it was confirmed that NaLa (PO ₃ ) ₄ having the target structure could be produced.

[Example 1: Production of Na _0.95 Q _0.05 La (PO ₃ ) ₄ (Q = Eu ³⁺ , Tb ³⁺ )]
A solid phase reaction method was used to synthesize a powder sample, which is a stress luminescent material. _{NaCl (99.5%), La 2} O 3, the _{(NH 4) 2 HPO 4 (} 98.5%), Eu 2 O 3 (99.9%), and _Tb 4 _O 7 (99.9%) composition ratio were weighed so that _{Na 0.95 Q 0.05 La (PO 3} ) 4 (Q = Eu, Tb), and wet-mixed with ethanol. The obtained mixed powder was calcined in air at 350 ° C. for 4 hours, and then calcined at 700 ° C. for 10 hours to obtain Na _0.95 Eu _0.05 La (PO ₃ ) ₄ and Na _0.95 Tb _0.05. A powder sample of La (PO ₃ ) ₄ was produced.

The obtained Na _0.95 Eu _0.05 La (PO ₃ ) ₄ and Na _0.95 Tb _0.05 La (PO ₃ ) ₄ powder samples were analyzed for crystal structure by the method described in Production Example 1. went. As a result, as shown in FIGS. 4B and 4C, it is confirmed that both belong to the monoclinic crystal (space group: P2 ₁ / n) and the desired frame network structure is formed. It was done. 4B is a diagram showing an XRD pattern of Na _0.95 Eu _0.05 La (PO ₃ ) ₄ , and FIG. 4C is a diagram showing Na _0.95 Tb _0.05 La (PO ₃ ) ₄ XRD patterns are shown.

Next, using the obtained Na _0.95 Eu _0.05 La (PO ₃ ) ₄ and Na _0.95 Tb _0.05 La (PO ₃ ) ₄ powder samples, the method described in Production Example 1 was performed. The excitation spectrum and emission spectrum were measured. As a result, as shown in FIG. 5B, in the emission spectrum of Na _0.95 Eu _0.05 La (PO ₃ ) ₄ , the linear emission spectrum was confirmed at the positions of 590 nm and 630 nm. This light emission is considered to be light emission due to the transition of Eu ³⁺ by ⁵ D _J → ⁷ F _{J ′} . As can be seen from the emission wavelength, Na _0.95 Eu _0.05 La (PO ₃ ) ₄ emitted red light. Eu ³⁺ is an f ⁶ -f ⁶ transition in the f ⁶ electron configuration, and is emitted by f electrons, so the emission color is not affected by the host structure. Therefore, it is considered that the emission color of Na _0.95 Eu _0.05 La (PO ₃ ) ₄ is red.

On the other hand, as shown in FIG. 5C, a linear emission spectrum peculiar to Tb ³⁺ was also observed in the emission spectrum of Na _0.95 Tb _0.05 La (PO ₃ ) ₄ . Since Tb ^{3+ is} also emitted by f electrons, the emission color is not affected by the host structure. Therefore, even in Na _0.95 Tb _0.05 La (PO ₃ ) ₄ in which the base structure is NaLa (PO ₃ ) ₄ , emission of ⁵ D ₄ → ⁷ F ₅ having the strongest emission band at 550 nm was exhibited. It is considered a thing. This is considered to be because the transition probability of ⁵ D ₄ → ⁷ F ₅ is the largest in both the electric dipole transition and the magnetic dipole transition.

[Example 2: Production of Na _0.95 Q _0.05 La (PO ₃ ) ₄ (Q = Ce ³⁺ , Tl ⁺ , Dy ³⁺ )]
As in Example 1, a solid phase reaction method was used for the synthesis of a powder sample, which is a stress-luminescent material. _{NaCl (99.5%), La 2} O 3, (NH 4) 2 HPO 4 (98.5%), CeO 2 (99.9%), TlNO 3 (99.9%), and _Dy 2 _{O 3} (99.9%) was weighed so that the composition ratio was Na _0.95 Q _0.05 La (PO ₃ ) ₄ (Q = Ce, Tl, Dy), and wet-mixed using ethanol. The obtained mixed powder was calcined in the atmosphere at 350 ° C. for 4 hours and then calcined in the atmosphere at 700 ° C. for 10 hours. However, under these conditions, it melted during firing, the product became hard and expanded, making it difficult to recover the sample. Therefore, the firing conditions were changed, and the mixed powder was calcined at 200 ° C. for 4 hours in the air and then fired at 600 ° C. for 40 hours in the air to obtain Na _0.95 Ce _0.05 La (PO ₃ ). ₄ , powder samples of Na _0.95 Tl _0.05 La (PO ₃ ) ₄ and Na _0.95 Dy _0.05 La (PO ₃ ) ₄ were prepared.

Obtained Na _0.95 Ce _0.05 La (PO ₃ ) ₄ , Na _0.95 Tl _0.05 La (PO ₃ ) ₄ , and Na _0.95 Dy _0.05 La (PO ₃ ) ₄ powders The sample was subjected to crystal structure analysis by the method described in Production Example 1. As shown in FIGS. 6A to 6C, all of the diffraction peaks coincided with NaLa (PO ₃ ) ₄ shown in the lower part of the graph. As a result, it was confirmed that the target framework structure was formed. 6A to 6C show Na _0.95 Ce _0.05 La (PO ₃ ) ₄ , Na _0.95 Tl _0.05 La (PO ₃ ) ₄ , and Na _{0.95, respectively.} The XRD pattern of Dy _0.05 La (PO ₃ ) ₄ is shown.

Next, the obtained Na _0.95 Ce _0.05 La (PO ₃ ) ₄ , Na _0.95 Tl _0.05 La (PO ₃ ) ₄ , and Na _0.95 Dy _0.05 La (PO ₃ ) _Using the powder sample No. ₄ , the excitation spectrum and the emission spectrum were measured by the method described in Production Example 1.

As a result, as shown in FIG. 7A, two peaks of 308 nm and 327 nm were observed in the emission spectrum of Na _0.95 Ce _0.05 La (PO ₃ ) ₄ . The excitation spectrum also had three peaks at 294 nm, 252 nm, and 223 nm, which were separated. The 3d level of Ce ³⁺ is the lowest among the trivalent rare earth ions. However, since the distance to the 4f excitation level ( ² F _7/2 , ~ 2000 cm ⁻¹ ) is large, the emission efficiency is generally high, and various light emission from the near ultraviolet part to the near infrared part depends on the host structure. Show. The dependence of the emission wavelength on the host structure is due to the splitting of the Ce ³⁺ 5d level crystal field. The energy level of the 5d excited state of Ce ³⁺ is large and splits into 5d ² T ₂ and 5d ² E. Then, 5d ² T ₂ is further separated by the spin orbit interaction. Also, the ground state of 4f is separated into ² F _5/2 orbits and ² F _7/2 orbits. Therefore, since the emission spectrum shown in FIG. 7A relaxes to the ground state ( ² F _5/2 , ² F _7/2 ) separated into two from the lowest excitation orbital at 5d ² T ₂ , It is thought that the emission spectrum is a peak.

Moreover, the excitation spectrum and emission spectrum of Na _0.95 Tl _0.05 La (PO ₃ ) ₄ were broad and broad spectra. The emission peak was 360 nm, which was found to show short wavelength emission.

Further, the emission spectrum of Na _0.95 Dy _0.05 La (PO ₃ ) ₄ showed a linear emission spectrum having peaks at 477 nm, 486 nm, and 573 nm. This is considered to be light emission due to the transition from ⁴ F _9/2 to ⁶ H _15/2 and the transition from ⁶ H _15/2 to ⁶ F _15/2 to ⁶ F _11/2 . Also, because it has a 470～500Nm, peaks at _570～600Nm, emission of _{Na 0.95 Dy 0.05 La (PO 3} ) 4 was found to appear in the emission color close to white.

[Example 3: Production of NaLa (PO ₃ ) ₄ : Ce ³⁺ ]
As in Example 1, a solid phase reaction method was used for the synthesis of a powder sample, which is a stress-luminescent material. NaCl (99.5%), La ₂ O ₃ , (NH ₄ ) ₂ HPO ₄ (98.5%), and CeO ₂ (99.9%) have a composition ratio of Na _1-x Ce _x La (PO ₃ ) ₄ (0.01 ≦ x ≦ 0.20) and weighed using ethanol. The obtained mixed powder was in the air, after 4 hours calcined at 200 ° C., in air and baked for 10 hours in the range of _{150~1000 ℃, Na 1-x Ce} x La (PO 3) 4 (0. A powder sample of 01 ≦ x ≦ 0.20) was produced.

As a result, in Na _0.90 Ce _0.10 La (PO ₃ ) ₄ , when the firing temperature was 1000 ° C., the sample adsorbed to the crucible and further evaporated, making it difficult to collect the sample. . Therefore, Na _0.90 Ce _0.10 La (PO ₃ ) ₄ powder samples obtained by firing at 400 ° C., 600 ° C., and 900 ° C. for 10 hours were each subjected to the crystal structure by the method described in Production Example 1. Analysis was performed. The powder X-ray diffraction pattern obtained as a result is shown in FIG. When the calcination temperature was 400 ° C. and 600 ° C., it coincided with the diffraction peak of NaLa (PO ₃ ) ₄ and a single phase was formed. On the other hand, when the calcination temperature was 900 ° C., it did not coincide with the diffraction peak of NaLa (PO ₃ ) ₄ . As a result of further detailed analysis, it was found that when the firing temperature was 900 ° C., an impurity phase of LaP ₃ O ₉ was formed. In other words, it was found that when firing at 900 ° C. for 10 hours, the target crystal structure could not be obtained because the temperature was too high.

Next, an excitation spectrum and an emission spectrum were measured by the method described in Production Example 1 using a powder sample of Na _0.90 Ce _0.10 La (PO ₃ ) ₄ obtained at each of the above firing temperatures. As a result, as shown in FIG. 8B, in the samples obtained at the firing temperatures of 400 ° C. and 600 ° C., three excitation bands were clearly observed in the excitation spectrum. On the other hand, in the sample obtained at the firing temperature of 900 ° C., no clear splitting of the excitation spectrum was seen. Also, the sample obtained at the baking temperature of 600 ° C. showed the maximum light emission intensity, while the sample obtained at the baking temperature of 900 ° C. had a very low light emission intensity. Furthermore, in the samples obtained at the baking temperatures of 400 ° C. and 600 ° C., the emission peak was 327 nm, whereas in the sample obtained at the firing temperature of 900 ° C., the emission peak was 322 nm, and the shorter wavelength side Had shifted to.

In addition, the sample obtained with a firing temperature of 600 ° C. and a firing time of 10 hours had high emission intensity, and the sample was easy to collect. Therefore, next, the firing temperature was set to 600 ° C., the firing time was set to 10 hours, and the dependence of the emission intensity on the amount of Ce ³⁺ added was examined.

Powder samples of each Ce ³⁺ addition amount were manufactured with the Ce ³⁺ addition amount being 0.01 at%, 0.05 at%, 0.10 at%, 0.15 at%, and 0.20 at%. The obtained powder sample was subjected to crystal structure analysis by the method described in Production Example 1. As a result, as shown in FIG. 9A, a single phase of NaLa (PO ₃ ) ₄ containing no impurities was formed in all the samples.

Next, the excitation spectrum and the emission spectrum were measured by the method described in Production Example 1 using the obtained powder sample. As a result, as shown in FIG. 9B, the sample to which 5 at% Ce ³⁺ was added showed the strongest light emission. In addition, when the addition amount of Ce ³⁺ increased from 5 at%, the emission intensity decreased. Further, no change in the shape of the excitation spectrum due to the addition amount of Ce ³⁺ was observed, and there were three excitation bands, and the maximum excitation wavelength was shown at 294 nm. Further, in the emission spectrum, no shift was observed due to the change in the amount of Ce ³⁺ added, and the emission peak was 327 nm.

Based on the above results, the firing conditions were further examined. Specifically, the firing time was 10 hours, and the firing temperature was 450 ° C, 500 ° C, 550 ° C, or 600 ° C. As a result, it was found that a sample with 15 at% Ce ³⁺ added, which was fired at a firing temperature of 550 ° C. in air for 10 hours, showed the maximum value of PL intensity (luminescence intensity). Therefore, Na _0.85 Ce _0.15 La (PO ₃ ) _{4 was} subjected to crystal structure analysis, excitation spectrum and emission spectrum measurement by the method described in Production Example 1. As a result, as shown in FIG. 10A, all diffraction peaks can be attributed to monoclinic crystals (space group: P2 ₁ / n), and a single phase of the target substance containing no impurities is formed. Was confirmed. Further, as shown in FIG. 10B, the maximum excitation wavelength was 294 nm. Furthermore, an emission spectrum having a strong emission peak at 327 nm was observed.

Stress emission evaluation was performed on Na _0.85 Ce _0.15 La (PO ₃ ) ₄ having such light emission characteristics. As an evaluation sample, 0.5 g of a powder sample of Na _0.85 Ce _0.15 La (PO ₃ ) ₄ and 4.5 g of an epoxy resin are mixed, and a disc-shaped composite pellet formed into a size φ25 × 9 mm is obtained. Using. Stress luminescence was evaluated using a stress luminescence measuring apparatus using a material testing machine. Uniaxial compression on the sample was evaluated using a common material testing machine equipped with a load gauge. The luminescence intensity of stress luminescence was measured using a photo counter through a photomultiplier tube (PHOTOMULTIPLIER TUBE). As the photomultiplier tube, R585 made by Hamamatsu was mainly used, and R649 made by Hamamatsu was used for the measurement on the long wavelength side. As an evaluation method, based on the excitation spectrum of FIG. 10B, ultraviolet light having a wavelength of 254 nm is irradiated, and after irradiating ultraviolet light having a wavelength of 254 nm for 1 minute, a uniaxial compressive force is applied to the sample held for 1 minute. It added with the test machine and the light emission in that case was measured with the optical fiber. The compressive stress was 1000 N, and a triangular waveform compressive stress was applied. In addition, the distance between the optical fiber and the sample surface was set to be closer than 40 mm, and 5 mm from the sample surface. The stress luminescence evaluation results are shown in FIG. In FIG. 11, the left axis represents the count number detected by the photon counter, and the right axis represents the magnitude of the compressive stress. As shown in FIG. 11, it was confirmed that the emission intensity of Na _0.85 Ce _0.15 La (PO ₃ ) ₄ increased as the compressive stress increased.

[Example 4: Production of NaLa (PO ₃ ) ₄ : Tl ⁺ ]
As in Example 1, a solid phase reaction method was used for the synthesis of a powder sample, which is a stress-luminescent material. NaCl (99.5%), La ₂ O ₃ , (NH ₄ ) ₂ HPO ₄ (98.5%), and TlNO ₃ (99.9%) have a composition ratio of Na _1-x Tl _x La (PO ₃ ) ₄ (0.01 ≦ x ≦ 0.20) and weighed using ethanol. The obtained mixed powder was in the air, after 4 hours calcined at 200 ° C. in air, and then fired for 10 hours in the range of _{150~1000 ℃, Na 1-x Ce} x La (PO 3) 4 (0. 01 ≦ x ≦ 0.20).

As a result, as the amount of Tl ⁺ added was increased, the reaction proceeded excessively, and the tendency to be easily dissolved was shown. In Na _0.90 La _0.10 La (PO ₃ ) ₄ , when the firing temperature was 1000 ° C., the sample could not be recovered. Therefore, the crystal structure analysis was performed by the method described in Production Example 1 for the powder samples obtained by baking at 400 ° C., 600 ° C., and 900 ° C. for 10 hours.

As a result, as shown in FIG. 12A, when the firing temperature is 400 ° C. and 600 ° C., it coincides with the diffraction peak of NaLa (PO ₃ ) ₄ , and the target NaLa (PO ₃ ) ₄ is single. A phase was formed. On the other hand, when the firing temperature is 900 ° C., it does not coincide with the diffraction peak of NaLa (PO ₃ ) ₄ , and it can be confirmed that an impurity phase of LaP ₃ O ₉ is formed as in Example 3. It was.

  Next, with respect to the obtained powder sample, the excitation spectrum and the emission spectrum were measured by the method described in Production Example 1. As a result, as shown in FIG. 12B, there was not much change in the emission intensity due to the difference in the firing temperature, and an emission peak was shown in the vicinity of 350 nm. The emission spectrum was broad and broad. Among them, the sample obtained at a firing temperature of 600 ° C. and a firing time of 10 hours had good crystallinity and a high recovery rate after firing.

Next, using a sample to which 1 at% of Tl ⁺ is added, the firing temperature is lowered by 50 ° C., specifically, 600 ° C., 550 ° C., 500 ° C., and 450 ° C. Dependency was examined. As a result, as shown in FIG. 13A, all diffraction peaks coincide with the diffraction peak of NaLa (PO ₃ ) ₄ shown at the bottom of the graph at any firing temperature, and NaLa (PO ₃ ) ₄ : Tl. It was confirmed that a single phase was formed.

  Furthermore, the excitation spectrum and the emission spectrum of the powder samples obtained at each firing temperature were measured by the method described in Production Example 1. As a result, as shown in FIG. 13 (b), only the sample obtained at the baking temperature of 500 ° C. exhibited splitting of the emission peak. Further, the emission peak of the sample obtained at the baking temperature of 500 ° C. was 367 nm, but the emission peak of the sample obtained at the other baking temperatures was 347 nm, and there was almost no shift. Furthermore, the emission intensity was highest in the sample obtained at a baking temperature of 600 ° C.

Next, the dependence of the emission intensity on the Tl ⁺ addition amount when the firing temperature was 600 ° C. and the firing time was 10 hours was examined.

Powder samples were prepared with Tl ⁺ addition levels of 0.01 at%, 0.05 at%, 0.10 at%, 0.15 at%, and 0.20 at%. The obtained powder sample was subjected to crystal structure analysis by the method of Production Example 1. As a result, as shown in FIG. 14A, all the diffraction peaks coincide with the diffraction peak of NaLa (PO ₃ ) ₄ in any composition, and a single phase of NaLa (PO ₃ ) ₄ : Tl ⁺ It was confirmed that was formed.

Next, the excitation spectrum and the emission spectrum were measured by the method described in Production Example 1 using the powder samples obtained at each Tl ⁺ addition amount. As a result, as shown in FIG. 14B, the emission peak shifted to the longer wavelength side as the Tl ⁺ addition amount increased. In addition, the sample with ¹ at% Tl ⁺ added showed the strongest emission. Furthermore, the maximum excitation wavelength was 228.2 nm and the emission peak was 347.6 nm.

Stress luminescence evaluation was performed on Na _0.99 Tl _0.01 La (PO ₃ ) ₄ baked in the atmosphere at a baking temperature of 600 ° C. and a baking time of 10 hours. As an evaluation sample, a disk-like composite pellet formed by mixing 0.5 g of Na _0.99 Tl _0.01 La (PO ₃ ) ₄ powder sample and 4.5 g of epoxy resin and molded into a size φ25 × 9 mm was used. . Stress luminescence was evaluated using a stress luminescence measuring apparatus using a material testing machine. Uniaxial compression on the sample was evaluated using a common material testing machine equipped with a load gauge. The luminescence intensity of stress luminescence was measured using a photo counter through a photomultiplier tube (PHOTOMULTIPLIER TUBE). As the photomultiplier tube, R585 made by Hamamatsu was mainly used, and R649 made by Hamamatsu was used for the measurement on the long wavelength side. As a stress luminescence evaluation method, it was decided to irradiate ultraviolet rays of 254 nm instead of 365 nm based on the excitation spectrum of FIG. A uniaxial compressive stress was applied to the sample held for 1 minute after being irradiated with ultraviolet rays for 1 minute, and the light emission at that time was measured with an optical fiber. The compressive stress was 1000 N, and a triangular waveform compressive stress was applied. The distance between the optical fiber and the sample surface was set at a position 5 mm from the sample surface. As a result, although not shown, it was confirmed that the emission intensity of Na _0.99 Tl _0.01 La (PO ₃ ) ₄ increased with increasing compressive stress.

From the results of Examples 1 to 4 above, it became clear that a stress-stimulated luminescent material having NaLa (PO ₃ ) ₄ as a base structure can be produced. A stress-stimulated luminescent material having NaLa (PO ₃ ) ₄ as a base structure is not conventionally known. Moreover, it became clear that a stress light-emitting material can be produced at a low firing temperature of 400 to 600 ° C. There is no conventional stress-stimulated luminescent material that can be produced at such a low firing temperature. Furthermore, it became clear that a stress-stimulated luminescent material that emits ultraviolet light having a wavelength lower than 350 nm can be produced. Such a stress-stimulated luminescent material that emits ultraviolet light having a low wavelength has not been known so far.

  Note that the present invention is not limited to the configurations described above, and various modifications are possible within the scope of the claims, and technical means disclosed in different embodiments and examples respectively. Embodiments and examples obtained by appropriately combining them are also included in the technical scope of the present invention. Moreover, all the academic literatures and patent literatures described in this specification are incorporated herein by reference.

As described above, since the present invention uses NaLa (PO ₃ ) ₄ as a base structure, it is possible to provide a stress-stimulated luminescent material having high luminance luminescent characteristics at a low firing temperature. Furthermore, by selecting the emission center, a stress-stimulated luminescent material that emits ultraviolet light having a wavelength lower than 350 nm, which is not conventionally used, can be provided. Therefore, the present invention can be used not only as a stress-stimulated luminescent material but also widely applied in industrial fields using stress-stimulated luminescent materials and stress-stimulated luminescent materials, for example, industrial fields such as electronics, medicine, chemistry and agriculture it can.

FIG. 1 is a diagram showing the crystal structure of NaLa (PO ₃ ) ₄ . FIG. 2 is a diagram showing a bond model of [(PO ₃ ) ₄ ] ⁴⁻ in the crystal structure of NaLa (PO ₃ ) ₄ . FIG. 3 is a diagram showing a structural model of La ³⁺ coordination bond in the crystal structure of NaLa (PO ₃ ) ₄ . 4 (a)-(c) shows NaLa (PO ₃ ) ₄ , Na _0.95 Eu _0.05 La (PO ₃ ) ₄ , and Na _0.95 Tb _0.05 La (PO ₃ ) _{4, respectively.} It is a figure which shows the XRD pattern. 5 (a)-(c) show NaLa (PO ₃ ) ₄ , Na _0.95 Eu _0.05 La (PO ₃ ) ₄ , and Na _0.95 Tb _0.05 La (PO ₃ ) _{4, respectively.} It is a figure which shows the excitation spectrum and emission spectrum of. FIGS. _6A to 6C show Na _0.95 Ce _0.05 La (PO ₃ ) ₄ , Na _0.95 Tl _0.05 La (PO ₃ ) ₄ , and Na _0.95 Dy _{0, respectively. .05} is a diagram showing the XRD pattern of La (PO ₃ ) ₄ . FIGS. 7A to 7C show Na _0.95 Ce _0.05 La (PO ₃ ) ₄ , Na _0.95 Tl _0.05 La (PO ₃ ) ₄ , and Na _0.95 Dy _{0, respectively. .05} is a diagram showing an excitation spectrum and an emission spectrum of La (PO ₃ ) ₄ . FIG. 8A is a diagram showing an XRD pattern of Na _0.90 Ce _0.10 La (PO ₃ ) ₄ fired at 400 ° C., 600 ° C., and 900 ° C., and FIG. ° C., illustrates 600 ° C., and the excitation and emission spectra of the calcined _{Na 0.90 Ce 0.10 La (PO 3} ) 4 at 900 ° C.. FIG. 9A shows Na _0.99 Ce _0.01 La (PO ₃ ) ₄ , Na _0.95 Ce _0.05 La (PO ₃ ) ₄ , Na _0.90 Ce _0.10 baked at 600 ° C. _{La (PO 3) 4, Na} 0.85 Ce 0.15 La (PO 3) 4, and _{Na 0.80 Ce 0.20 La (PO 3} ) is a diagram showing a ₄ XRD pattern, FIG. 9 (b ) Na _0.99 Ce _0.01 La (PO ₃ ) ₄ , Na _0.95 Ce _0.05 La (PO ₃ ) ₄ , Na _0.90 Ce _0.10 La (PO ₃ ) calcined at 600 ° C. FIG. ₄ is a diagram showing excitation spectra and emission spectra of Na ₄ , Na _0.85 Ce _0.15 La (PO ₃ ) ₄ , and Na _0.80 Ce _0.20 La (PO ₃ ) ₄ . FIG. 10A is a diagram showing an XRD pattern of Na _0.85 Ce _0.15 La (PO ₃ ) ₄ fired at 550 ° C., and FIG _{. 85} Ce _0.15 La _{(PO 3)} is a diagram showing the excitation and emission spectra of _four. FIG. 11 is a diagram showing a stress luminescence response curve of Na _0.85 Ce _0.15 La (PO ₃ ) ₄ fired at 550 ° C. FIG. 12A is a diagram showing an XRD pattern of Na _0.90 Tl _0.10 La (PO ₃ ) ₄ fired at 400 ° C., 600 ° C., and 900 ° C., and FIG. ° C., illustrates 600 ° C., and the excitation and emission spectra of the calcined _{Na 0.90 Tl 0.10 La (PO 3} ) 4 at 900 ° C.. FIG. 13 (a) is a diagram showing an XRD pattern of Na _0.99 Tl _0.01 La (PO ₃ ) ₄ baked at 450 ° C., 500 ° C., 550 ° C., and 600 ° C., and FIG. is, 450 ℃, 500 ℃, 550 ℃, and 600 ° C. in calcined _{Na 0.99 Tl 0.01 La (PO 3} ) is a diagram showing the excitation and emission spectra of _four. FIG. 14 (a) shows that Na _0.99 Tl _0.01 La (PO ₃ ) ₄ , Na _0.95 Tl _0.05 La (PO ₃ ) ₄ , Na _0.90 Tl _0.10 baked at 600 ° C. FIG. 14 shows XRD patterns of La (PO ₃ ) ₄ , Na _0.85 Tl _0.15 La (PO ₃ ) ₄ , and Na _0.80 Tl _0.20 La (PO ₃ ) ₄ , and FIG. ) Na _0.99 Tl _0.01 La (PO ₃ ) ₄ , Na _0.95 Tl _0.05 La (PO ₃ ) ₄ , Na _0.90 Tl _0.10 La (PO ₃ ) calcined at 600 ° C. FIG. ₄ is a diagram showing excitation spectra and emission spectra of Na ₄ , Na _0.85 Tl _0.15 La (PO ₃ ) ₄ , and Na _0.80 Tl _0.20 La (PO ₃ ) ₄ .

Claims (17)

The following general formula (a)
MN (PO ₃ ) ₄ (a)
(In the formula, M is a monovalent metal ion and N is a trivalent metal ion.)
The structure represented by
A stress-stimulated luminescent material, wherein a part of M or N in the general formula (a) is substituted with at least one of a rare earth ion and a group III metal ion.   2. The stress-stimulated luminescent material according to claim 1, wherein M in the general formula (a) is an alkali metal ion and N is a rare earth ion.   In the general formula (a), M is Na ion, K ion, Rb ion, or Cs ion, and N is Ce ion, Pr ion, Nd ion, Pm ion, Sm ion, Eu ion, Gd ion, Tb ion. The stress-stimulated luminescent material according to claim 1, wherein the stress luminescent material is Dy ion, Ho ion, Er ion, Tm ion, Yb ion, La ion, or Y ion.   2. The stress-stimulated luminescent material according to claim 1, wherein M in the general formula (a) is Na ion, and N is La ion. The rare earth ion substituted with a part of M or N in the general formula (a) is composed of Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb. A rare earth ion selected from the group,
5. The stress-stimulated luminescent material according to claim 1, wherein the group III metal ion substituted with a part of M or N in the general formula (a) is a Tl ion. The rare earth ion substituted with a part of M or N in the general formula (a) is a rare earth ion selected from the group consisting of Eu, Dy, Ce, and Tb.
5. The stress-stimulated luminescent material according to claim 1, wherein the group III metal ion substituted with a part of M or N in the general formula (a) is a Tl ion.   The rare earth ion substituted with a part of M or N in the general formula (a) is a Ce ion, and the group III metal ion substituted with a part of M or N in the general formula (a) is Tl. It is an ion, The stress luminescent material of any one of Claims 1-4 characterized by the above-mentioned.   8. The content of rare earth ions and group III metal ions substituted for a part of M or N in the general formula (a) is 0.1 to 20 mol%. 2. The stress-stimulated luminescent material according to item 1.   The stress-stimulated luminescent material according to claim 1, which emits ultraviolet rays.   The stress-stimulated luminescent material according to claim 1, which emits ultraviolet rays having a wavelength shorter than 350 nm. The composition formula is the following general formula (b)
Na _1-x Q _x La (PO ₃ ) ₄ (b)
(In the formula, Q is Ce ion or Tl ion, and x is a number satisfying 0.01 ≦ x ≦ 0.2.)
The stress-stimulated luminescent material according to claim 1, wherein A manufacturing method for manufacturing the stress-stimulated luminescent material according to any one of claims 1 to 11,
The raw materials are mixed and fired in the atmosphere at 200 to 350 ° C. for 1 to 4 hours.
Furthermore, the manufacturing method of the stress luminescent material characterized by baking at 400-600 degreeC in air | atmosphere for 10 to 40 hours.   The stress light-emitting body formed by shape | molding the stress luminescent material of any one of Claims 1-11.   A stress-stimulated luminescent material obtained by mixing the stress-stimulated luminescent material according to claim 1 and a polymer material.   The stress-stimulated luminescent material according to claim 13 or 14, wherein the stress luminescent material is used in a one-dimensionally dispersed manner.   The stress-stimulated luminescent material according to claim 13 or 14, wherein the stress-stimulated luminescent material is distributed two-dimensionally.   The stress-stimulated luminescent material according to claim 13 or 14, wherein the stress-stimulated luminescent material is distributed three-dimensionally.