JP2009286927A - Stress-induced light emitter, production method thereof, and composite material and level sensor each using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stress-induced light emitter which has an improved stress-induced light intensity in spite of containing a reduced amount of a rare earth metal and to provide a production method thereof. <P>SOLUTION: The stress-induced light emitter is a stress-induced light emitter containing a matrix material which emits light upon receiving stress and contains a transition metal (except a rare earth metal) and further contains at least either element of Si and Sn, wherein at least part of the element is mixed with the matrix material in a state not solid-dissolved therein. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a stress-stimulated luminescent material, a manufacturing method thereof, a composite material using the stress luminescent material, and a level sensor.

  As an excitation source of a luminescent material, ultraviolet rays, electron beams, X-rays, radiation, electric fields, chemical reactions, etc. are generally known. However, the material is generated by mechanical force (mechanical energy) applied from the outside. There is also a phenomenon of light emission. This phenomenon is called a stress luminescence phenomenon.

  The stress luminescence phenomenon includes destructive luminescence and deformation luminescence. Destructive luminescence has been known for a long time, and is a phenomenon in which light is emitted when a solid is destroyed. Deformed light emission is not accompanied by destruction, and is divided into light emission in an elastic deformation region and light emission in a plastic deformation region. The destructive luminescence phenomenon has been observed in a large number of material systems, and about half of the inorganic substances are said to have destructive luminescence properties. On the other hand, the deformation light emission was weak light emission in the plastic deformation region although there were some reports of radiation-induced alkali halides and certain polymers.

  In recent years, various inorganic materials that emit reversibly strong light emission in proportion to stress or strain energy in an elastic deformation region with small mechanical energy have been reported (for example, see Patent Document 1). In many of these, a rare earth metal serving as a luminescent center is added in an inorganic crystal skeleton whose structure is highly controlled. Materials that emit light at various wavelengths from ultraviolet to visible to infrared have been obtained by selecting the kind of inorganic material or emission center.

Examples of the rare earth metal serving as the luminescent center include strontium aluminate to which europium is added (SrAl ₂ O ₄ : Eu, luminescent in green). The human visual sensitivity may be best in the green region of 500 to 600 nm, and the luminescence of europium-added strontium aluminate can be sufficiently confirmed with the naked eye. Furthermore, since the stress luminescence intensity is proportional to the strain energy in the elastic region, it has been demonstrated that the stress distribution can be directly visualized from the stress luminescence image.

By the way, transition metal such as Zr becomes the host of the phosphor in the form of CaZrO ₃ or the like in the phosphor (see Patent Documents 2 and 3), or the emission center of the phosphate phosphor that can be excited in the vacuum ultraviolet region. (See Patent Document 4), adding to an aluminate-based mother crystal together with Eu to give an effect of lengthening the afterglow of fluorescence (see Patent Document 5), or using yttrium oxide as a base material, Functions such as further improving the light emission luminance by electron beam excitation by replacing a part (see Patent Document 6), and imparting water resistance and an initial light emission decrease suppressing effect by surface coating (see Patent Document 7). It is known to have.
International Publication No. 2005/097946 Pamphlet (October 5, 2005) Japanese Unexamined Patent Publication No. 1996-283713 (released on October 29, 1996) JP 2001-107038 A (published April 17, 2001) JP 2006-282907 A (published on October 19, 2006) Japanese Unexamined Patent Publication No. 1996-73845 (published on March 19, 1996) JP 2006-265396 A (released on October 5, 2006) JP 2006-124680 A (published May 18, 2006)

  As described above, the rare earth metal used as the emission center in the stress-stimulated luminescent material is a useful substance that is widely used in various materials such as superconductivity and catalysts. However, the total reserves of rare earth metals are very limited, and Japan relies on supply from certain countries. In 2006, the top producers of rare earth metals were China, India, and Thailand, with each country's production accounting for 93%, 3%, and 2% of the global share, respectively.

  In order to secure such a valuable resource, it is necessary to reduce the amount of rare earth metal used in the stress-stimulated luminescent material. Therefore, it is necessary to develop a stress-stimulated luminescent material with high stress luminescence intensity while using a metal that can be supplied more stably, such as transition elements other than rare earth metals.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a stress-stimulated luminescent material having high stress luminescence intensity and a method for producing the same while suppressing the amount of rare earth metal used.

  The present inventor has intensively studied to solve the above problems. Specifically, the transition metal other than the rare earth metal is added so as to be in a non-solid solution state with respect to the base material that emits light when subjected to stress, and the effect on the stress emission characteristics is examined. Was done. As a result, it has been found that a stress luminescent material with high stress luminescence intensity can be obtained while containing a transition metal other than a rare earth metal in a non-solid solution state while suppressing the amount of rare earth metal used. The invention has been completed.

  That is, the present invention includes the following inventions.

  The stress-stimulated luminescent material according to the present invention is a stress-stimulated luminescent material including a host material that emits light when subjected to stress, and further includes at least one element of transition metal (excluding rare earth metals), Si and Sn, It is characterized in that at least a part of the element is contained in the matrix material in a non-solid solution state.

  Furthermore, in the stress-stimulated luminescent material according to the present invention, it is more preferable that the element is present in the form of particles on the surface of the base material.

  Furthermore, in the stress-stimulated luminescent material according to the present invention, the content of the above elements is more preferably 0.1 mol% or more and 90 mol% or less.

  Furthermore, in the stress-stimulated luminescent material according to the present invention, the content of the element is more preferably 10 mol% or more and 90 mol% or less.

  Furthermore, in the stress-stimulated luminescent material according to the present invention, the content of the element is more preferably 0.1 mol% or more and less than 10 mol%.

  Furthermore, in the stress-stimulated luminescent material according to the present invention, the element is selected from the group consisting of Zr, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Hf, Nb, Mo, Ta, and W. More preferably, it is at least one metal.

  Furthermore, in the stress-stimulated luminescent material according to the present invention, the base material includes at least one compound selected from the group consisting of metal oxides, metal nitrides, and metal sulfides, and further includes a rare earth metal as a luminescent center. More preferred.

  Furthermore, in the stress-stimulated luminescent material according to the present invention, the metal oxide is more preferably at least one compound selected from the group consisting of aluminate and aluminosilicate.

  Furthermore, in the stress-stimulated luminescent material according to the present invention, the rare earth metal is composed of Eu, Dy, La, Gd, Ce, Sm, Y, Nd, Tb, Pr, Er, Tm, Yb, Sc, Pm, Ho, and Lu. More preferably, it is an ion of at least one metal selected from the group.

  Furthermore, the composite material according to the present invention is characterized by including the stress-stimulated luminescent material.

  Furthermore, a level sensor according to the present invention is characterized by including the stress-stimulated luminescent material.

  Further, in the method for producing a stress-stimulated luminescent material according to the present invention, in a composition in which a base material that emits light when subjected to stress is in a solid solution state, the raw materials are mixed, and further a transition metal (excluding rare earth metals), It includes a mixing step of mixing at least one element of Si and Sn, and a baking step of baking the mixture obtained by the mixing step.

  As described above, the stress-stimulated luminescent material according to the present invention is a stress-stimulated luminescent material including a base material that emits light when subjected to stress, and includes at least one of transition metals (except rare earth metals), Si, and Sn. An element is further included, and at least a part of the element is contained in the base material in a non-solid solution state.

  Since the non-solid solution portion present in the stress luminescent material forms a harder phase than the base material and the stress is easily concentrated, the stress luminescence intensity is high.

  In addition, by increasing the proportion of transition metals other than rare earth metals, Si and Sn in the stress-stimulated luminescent material, the amount of rare earth metals used is limited, and the amount of reserves is limited. It also has the effect of being suppressed.

  Hereinafter, the present invention will be described in detail.

<1. Stress-stimulated luminescent material according to the present invention>
The stress-stimulated luminescent material according to the present invention is a stress-stimulated luminescent material including a host material that emits light upon receiving stress, and includes at least one element of transition metal (excluding rare earth metals), Si, and Sn (hereinafter described) For the sake of convenience, it is referred to as “transition metal etc.”), and at least a part of the transition metal etc. is contained in the base material in a non-solid solution state.

  In the present specification, the “non-solid solution state” means a state where two or more kinds of substances existing as independent elements or compounds exist as a solid, but are not dissolved but phase-separated, For example, it means a state in which neither a substitutional solid solution nor an interstitial solid solution is formed.

  In the present specification, “transition metal” means an element of each group of the periodic tables 3 to 12, and “rare earth metal” means 15 elements of Sc, Y and lanthanoid (La, Ce, Pr, Nd). , Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu). However, rare earth metals are excluded from transition metals and the like further included in the base material in the stress-stimulated luminescent material according to the present invention. Therefore, for convenience of explanation, hereinafter, the term “transition metal” simply means “transition metal (excluding rare earth metals)”.

  A transition metal or the like contained in a non-solid solution state with respect to the base material forms a harder phase than the base material, and stress tends to concentrate in the vicinity thereof. Due to this stress concentration effect, the stress luminescence intensity of the stress luminescent material can be further improved as compared with the stress luminescent material not containing the transition metal or the like. Furthermore, not only the stress concentration effect but also the high strength of the stress is considered to be improved for the following reason. That is, it is considered that a small part of Zr is dissolved in the host crystal. This is because, as a result of the analysis of the lattice defect concentration by the present inventors, it has been found that the lattice defect concentration increases with the stress emission intensity by adding Zr. Therefore, it is considered that the addition of Zr not only facilitates the concentration of stress due to the formation of a hard phase, but also forms appropriate lattice defects in the host crystal and facilitates deformation (easily distorted). It is done. The same applies to other transition metals.

[1-1. (Matrix material)
Specific examples of the host material contained in the stress-stimulated luminescent material according to the present invention are not particularly limited, but include at least one compound selected from the group consisting of metal oxides, metal nitrides, and metal sulfides, And those further containing a rare earth metal. The base material may contain at least one metal selected from the group consisting of alkali metals and alkaline earth metals for charge compensation. When the base material of the stress-stimulated luminescent material according to the present invention contains an alkali metal and / or an alkaline earth metal, a part thereof may be substituted with a rare earth metal serving as a luminescence center.

  The metal oxide is not particularly limited, and examples thereof include aluminate, aluminosilicate, phosphate, silicate, magnesium oxide and the like. Among these, at least one compound selected from the group consisting of aluminate and aluminosilicate is preferable.

  Although it does not specifically limit as a metal sulfide, Zinc sulfide, iron sulfide, molybdenum sulfide, lead sulfide, etc. are mentioned.

  The metal nitride is not particularly limited, and examples thereof include aluminum nitride, iron nitride, niobium nitride, and titanium nitride.

  The rare earth metal serving as the emission center is not particularly limited as long as it is in the above-mentioned “rare earth metal” category, but Eu and Ce are more preferable.

  In the stress-stimulated luminescent material according to the present invention, in addition to the transition metal to be contained in the non-solid solution state, the base material may further contain a transition metal or the like as the luminescent center. Although it does not specifically limit as a transition metal etc. which become a light emission center, Zr, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Hf, Nb, Mo, Ta, W etc. are mentioned. Among these, Mn is preferable. In addition, a transition metal contained in a non-solid solution state may be the emission center.

  Although it does not specifically limit as an alkali metal, Na, K, Rb, Cs etc. are mentioned. Although it does not specifically limit as an alkaline-earth metal, Ca, Sr, Ba, Ra etc. are mentioned. Of these, Sr and Ca are preferable.

  Considering that the content of alkali metal and / or alkaline earth metal is replaced by rare earth metal, from the stoichiometric composition of the base material from 0.1 mol% so as to have a non-stoichiometric composition It is preferable to reduce the amount by 20 mol%. Thereby, the light emission intensity can be further improved. “Non-stoichiometric composition” means a state where the elements of the composition formula do not have a simple integer ratio because the elements constituting the crystal are locally excessive or insufficient.

  The rare earth metal content is preferably 0.1 mol% or more and 20 mol% or less, more preferably 0.2 mol% or more and 10 mol% or less, and 0.5 mol% or more and 5 mol% or less. Is particularly preferred. Thereby, the base material can be made to emit light effectively.

[1-2. Transition metals, etc.)
In the stress-stimulated luminescent material according to the present invention, at least a part of a transition metal or the like is further contained in a non-solid solution state in the base material that emits light by receiving stress.

  As long as the transition metal or the like is contained in the base material in a non-solid solution state, the state of the transition metal or the like in the stress-stimulated luminescent material according to the present invention is not limited, but it may be present in the form of particles on the surface of the base material. preferable. The particle size is more preferably 10 nm or more and 500 nm or less.

  Further, in the stress-stimulated luminescent material according to the present invention, the transition metal contained in a non-solid state may be a part or all of the transition metal contained in the stress-stimulated luminescent material. .

  The content of the transition metal in a non-solid solution state is not particularly limited, but is preferably 0.1 mol% or more and 90 mol% or less.

  In addition, when the content of the transition metal or the like is 10 mol% or more and 90 mol% or less, a saturation phenomenon is observed in which the stress emission intensity becomes constant when a stress of a certain load or more is applied. It is possible to control the saturation stress value and adjust the sensitivity of stress emission.

  When the content of the transition metal or the like is 0.1 mol% or more and less than 10 mol%, the stress-stimulated luminescent material according to the present invention emits stress with strong intensity as the applied load increases. A stress-stimulated luminescent material with improved stress luminescence intensity can be obtained while suppressing the amount of rare earth metal used.

  Although it does not specifically limit as a specific example of the transition metal etc. which are contained in the stress light-emitting body based on this invention in the non-solid solution state, Zr, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn , Hf, Nb, Mo, Ta, W and the like. Of these, Zr and Hf are preferable.

<2. Method for producing stress-stimulated luminescent material according to the present invention>
The method for producing a stress-stimulated luminescent material according to the present invention is a composition in which a base material that emits light when subjected to stress is in a solid solution state, the raw materials are mixed, and a transition metal (however, excluding rare earth metals) is mixed. And a firing step of firing the mixture obtained by the mixing step.

[2-1. (Mixing process)
In the mixing step included in the method for producing a stress-stimulated luminescent material according to the present invention, the raw materials are mixed in a composition in which the base material is in a solid solution state, and further transition metals (except for rare earth metals) are mixed. Good. When a transition metal or the like is further added to the base material in a solid solution state, at least a part of the transition metal is not dissolved in the base material and is mixed in a non-solid solution state.

About the raw material of a base material, it is good to weigh a raw material so that it may become a composition in a solid solution state. For the constituent atomic ratio having the stress luminescence property, a known document (for example, see Patent Document 1) may be referred to. Further, for example, when using strontium carbonate SrCO ₃ , aluminum oxide Al ₂ O ₃ , and europium oxide Eu ₂ O ₃ as raw materials as in Examples described later, Sr _0.99 Eu _0.01 Al ₂ O _4. When using calcium carbonate CaCO ₃ , aluminum oxide Al ₂ O ₃ , silicon dioxide SiO ₂ , europium oxide Eu ₂ O ₃ , Ca _0.99 Eu _0.01 Al ₂ Si ₂ O _It may be set to ₈ .

At this time, a transition metal or the like may be included in the base material in a solid solution state. That is, a part of the produced transition metal or the like may be contained in a solid solution state as a part of the base material. For example, by adding a raw material serving as a supply source of xmol transition metal or the like to a raw material having a composition of Sr _0.99-x Eu _0.01 Al ₂ O ₄ , the above-mentioned “matrix material is in a solid solution state. The raw materials may be “mixed in composition”. Further, when a transition metal or the like is further added, the mixed step is performed because the transition metal or the like is added in a non-solid solution state.

  Each raw material of the base material is not particularly limited as long as it becomes an oxide by firing. As such a raw material, an inorganic substance (carbonate, oxide, halide, hydroxide, sulfate, nitrate, etc.) of an alkali metal or an alkaline earth metal can be used. In addition, an inorganic substance of a rare earth metal or a transition metal (oxide, sulfide, nitride, halide, hydroxide, carbonate, sulfate, nitrate, or the like) can also be used.

  The timing of adding each raw material of the base material and the transition metal is not particularly limited, but the method of adding the transition metal that is mixed in a non-solid solution state after adding each raw material of the base material, each raw material of the base material And a method of simultaneously adding a transition metal or the like mixed in a non-solid solution state. In particular, a method of simultaneously adding each raw material of the base material and a transition metal to be mixed in a non-solid solution state is preferable.

  Moreover, it does not specifically limit about the method of mixing, What is necessary is just to carry out using a ball mill, a mortar, etc.

  In the mixing step, a solvent may be used. The solvent may be appropriately selected depending on the raw materials, and examples thereof include methanol, ethanol, butanol and the like.

  Further, the obtained mixture may be dried after the mixing step and before the firing step described later. Although it does not specifically limit as drying conditions, For example, what is necessary is just to carry out for 1 to 10 hours at 50-200 degreeC. Moreover, you may grind | pulverize the mixture after making it dry.

[2-2. (Baking process)
In the firing step, the mixture obtained in the mixing step may be fired.

  The gas for forming the atmosphere when performing the firing step is not particularly limited, and air, nitrogen gas, inert gas (for example, argon gas), hydrogen-containing inert gas (for example, hydrogen-containing argon gas) Etc. Moreover, you may perform a baking process in a vacuum. Among these, a hydrogen-containing inert atmosphere that is a reducing atmosphere is more preferable, and hydrogen-containing argon gas is more preferable. When performing a baking process in the reducing atmosphere by hydrogen-containing inert gas, it is although it does not specifically limit as content of hydrogen, It is preferable that it is 1 volume%-10 volume%.

  The firing temperature is not particularly limited, but may be fired at 1000 to 1600 ° C. in a reducing atmosphere. Although it does not specifically limit as baking time, It is good to carry out for 1 to 10 hours. Although the rate of temperature increase and temperature decrease is not particularly limited, it may be performed at 1 to 5 ° C./min.

  Moreover, temporary baking may be performed before the baking process, and the baking process may be the main baking. When pre-baking is performed, it is more preferably performed in an oxidation-reduction atmosphere, and the temperature is more preferably 500 to 1000 ° C., but is not limited thereto.

<3. Composite Material, Level Sensor According to the Present Invention>
The form using the stress-stimulated luminescent material according to the present invention is not particularly limited, and it is applied to the surface of the support material as a form of powder or sintered body, which is mixed with other materials and molded. The form etc. are mentioned. The form of the powder or sintered body is a form in which the stress luminescent material obtained in the present invention is used almost as it is, and the particle size and particle size distribution of the powder, the shape and size of the sintered body are not particularly limited. Absent.

  In this specification, the “composite material” means a material formed by mixing with other materials, a material applied to the surface of a support material, or the like. And the composite material which concerns on this invention should just contain the stress light-emitting body based on the above-mentioned this invention.

  When the composite material according to the present invention is manufactured by further mixing the stress-stimulated luminescent material according to the present invention with other materials, the stress-stimulated luminescent material according to the present invention is mixed or embedded with a polymer material or the like in an arbitrary ratio to be combined. A material can be formed. Examples of the polymer material include an epoxy resin, an acrylic resin, and a urethane resin. The mixing conditions are not particularly limited, and a known method may be used. When a mechanical external force is applied to the composite material, light can be emitted with mechanical deformation of the light emitter.

  Moreover, when apply | coating to the surface of a support material, it becomes a composite material which has a laminated structure, for example. As a result of laminating other materials on the stress luminescent material, the stress luminescent material according to the present invention may not be present on the outermost surface. The support is not particularly limited and may be any of metal, fiber, rubber, paper, glass and the like. When a mechanical external force is applied to the composite material, the surface of the material or the inner light-emitting layer emits light by deformation. If such a method is used, light emission of a large area can be obtained using a small number of light emitters.

  In this specification, the level sensor means a sensor that detects and warns that a state in which the light emission intensity is saturated and shows a constant value when a certain stress or more is applied. And the level sensor which concerns on this invention should just contain the stress light-emitting body which concerns on this invention.

  In the stress-stimulated luminescent material according to the present invention, the saturation stress value is changed by adjusting the amount of transition metal or the like added to the base material. By utilizing this property, the sensitivity of stress luminescence can be adjusted, so that a level sensor can be manufactured according to the application. For example, it is possible to manufacture a level sensor that issues a warning when an excessive load is applied by embedding the stress light emitter according to the present invention on the wall or floor of a house.

  Examples will be shown below, and the embodiments of the present invention will be described in more detail. Of course, the present invention is not limited to the following examples, and it goes without saying that various aspects are possible in detail. Further, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims, and the present invention is also applied to the embodiments obtained by appropriately combining the disclosed technical means. It is included in the technical scope of the invention. Moreover, all the literatures described in this specification are used as reference.

[Example 1]
Strontium carbonate SrCO ₃ , aluminum oxide Al ₂ O ₃ , europium oxide Eu ₂ O ₃ , and zirconia ZrO ₂ are converted into (1-x) Sr _0.99 Eu _0.01 Al ₂ O ₄ .xZrO ₂ (x = 0.0). A predetermined amount was weighed so as to obtain the composition of (05). Specifically, 0.2923 g of SrCO ₃ , 0.2039 g of aluminum oxide Al ₂ O ₃ , 0.0035 g of europium oxide Eu ₂ O _3, and 0.0123 g of zirconia ZrO ₂ were weighed.

  Next, the weighed raw materials were put in ethanol, mixed thoroughly using a ball mill, and then dried at 80 ° C. The obtained mixture was pulverized in a mortar and then calcined at 1400 ° C. for 4 hours in a reducing atmosphere (5% hydrogen-containing argon). The temperature increase and decrease were performed slowly at a rate of 2 ° C./min.

  Next, the material obtained after firing was pulverized to prepare a powder of a stress luminescent material.

  This powder was observed using an electron microscope. The results are shown in FIG. FIG. 1 is a diagram showing the result of observing the stress-stimulated luminescent material obtained in this example with an electron microscope. FIG. 1 (a) shows a reflected electron image, and FIG. 1 (b) shows a real image. From FIG. 1, it was confirmed that Zr was present in a non-solid solution with respect to the base material, specifically, it was present in the form of particles on the surface of the base material.

  In addition, the powder was subjected to X-ray diffraction (XRD) measurement, ultraviolet excitation luminescence (PL) measurement, and stress luminescence (ML) measurement.

  For the measurement of XRD, RINT-2000; Rigaku Corporation was used. For ML, C.I. N. Xu, in Encyclopedia of smart materials, Vol. 1 (Ed: M. Schwartz), Wiley, New York pp190 2002. This system includes a universal testing machine (RTC-1310A; Orientec) and a photon counting system comprising a photomultiplier tube (R585S; Hamamatsu Photonics) and a photon counter (C5410-51; Hamamatsu Photonics). ing. For measurement of PL, a spectrofluorometer (FP6600; Jusco) equipped with a 150 W xenon lamp was used.

  XRD and PL were measured using only a stress luminescent material powder, and ML was measured using a composite material containing the stress luminescent material powder. This composite material is prepared by mixing the above powder with an optical epoxy resin (SpeciFix epoxy resin (manufactured by Struers)) as a disk-shaped pellet having a diameter of 25 mm and a thickness of 15 mm.

The measurement result of XRD is shown in FIG. FIG. 2 is a diagram showing the XRD measurement results of the stress-stimulated luminescent material obtained in this example and Comparative Example 1 described later. The peak indicated by the arrow in FIG. 2 indicates Zr origin (SrZrO ₃ ).

  Moreover, the measurement result of ML is shown in FIG. FIG. 3 is a diagram showing the measurement results of ML of the stress-stimulated luminescent material obtained in this example and Comparative Examples 1 and 3. As shown in FIG. 3, it was confirmed that the stress-stimulated luminescent material of Example 1 showed stronger luminescence intensity than the stress-stimulated luminescent materials of Comparative Examples 1 and 3. Moreover, in the stress light-emitting body which concerns on Example 1, it was shown that emitted light intensity becomes strong as stress increases. By the way, Comparative Example 3 is obtained by mixing zirconia with a base material in a solid solution state. Comparison between Example 1 and Comparative Example 3 showed that the luminescent intensity of the stress luminescent material formed by mixing zirconia in a non-solid solution state was high.

  Moreover, the measurement result of PL is shown in FIG. FIG. 4 is a diagram showing the measurement results of PL of the stress-stimulated luminescent material obtained in this example and Comparative Example 1. There was no emission peak shift due to the presence or absence of Zr addition, and the emission color was the same.

[Example 2]
Calcium carbonate CaCO ₃ , Al ₂ O ₃ , SiO ₂ , Eu ₂ O ₃ , and ZrO ₂ are converted into (1-x) [Ca _0.99 Eu _0.01 Al ₂ Si ₂ O ₈ ] · xZrO ₂ (x = 0.05), a predetermined amount was weighed. Specifically, 0.0999 g of CaCO ₃ , 0.1020 g of Al ₂ O ₃ , 0.0120 g of SiO ₂ , 0.0018 g of Eu ₂ O _3, and 0.0062 g of ZrO ₂ were weighed.

  Next, the weighed raw materials were put in ethanol, mixed thoroughly using a ball mill, and then dried at 80 ° C. The resulting mixture was pulverized in a mortar and then baked at 1400 ° C. for 4 hours in a reducing atmosphere (5% hydrogen-containing argon). The temperature increase and decrease were performed slowly at a rate of 2 ° C./min.

  Next, the material obtained after firing was pulverized to prepare a powder of a stress luminescent material. And ML measurement was performed by the same method as Example 1 about this powder.

  The measurement result of ML is shown in FIG. FIG. 5 is a diagram showing the measurement result of ML of the stress-stimulated luminescent material obtained in this example and Comparative Example 2. As shown in FIG. 5, it was confirmed that the stress-stimulated luminescent material of Example 2 showed stronger luminescence intensity than the stress-stimulated luminescent material of Comparative Example 2. It was also shown that the emission intensity increased as the stress increased.

Example 3
x = 0.30, i.e. _{0.70Sr 0.99 Eu 0.01 Al 2 O 4} · 0.30ZrO so as to have the composition of _2, except for changing the amount of ZrO ₂ is stress in the same manner as in Example 1 Synthesis of the luminescent material and ML measurement were performed. Specifically, SrCO ₃ was 0.2923 g, Al ₂ O ₃ was 0.2039 g, Eu ₂ O ₃ was 0.0035 g, and ZrO ₂ was 0.1056 g.

Example 4
x = 0.50, i.e. _{0.50Sr 0.99 Eu 0.01 Al 2 O 4} · 0.50ZrO so as to have the composition of _2, except for changing the amount of ZrO ₂ is stress in the same manner as in Example 1 Synthesis of the luminescent material and ML measurement were performed. Specifically, SrCO ₃ was 0.2923 g, Al ₂ O ₃ was 0.2039 g, Eu ₂ O ₃ was 0.0035 g, and ZrO ₂ was 0.2464 g.

Example 5
x = 0.7, i.e. _{0.30Sr 0.99 Eu 0.01 Al 2 O 4} · 0.70ZrO so as to have the composition of _2, except for changing the amount of ZrO ₂ is stress in the same manner as in Example 1 Synthesis of the luminescent material and ML measurement were performed. Specifically, SrCO ₃ was 0.2923 g, Al ₂ O ₃ was 0.2039 g, Eu ₂ O ₃ was 0.0035 g, and ZrO ₂ was 0.5749 g.

Example 6
Stress is the same as in Example 1 except that the amount of ZrO ₂ was changed so that x = 0.10, that is, 0.90Sr _0.99 Eu _0.01 Al ₂ O ₄ · 0.10ZrO _2. Synthesis of the luminescent material and ML measurement were performed. Specifically, SrCO ₃ was 0.2923 g, Al ₂ O ₃ was 0.2039 g, Eu ₂ O ₃ was 0.0035 g, and ZrO ₂ was 0.0274 g.

  Next, ML was measured for the stress-stimulated luminescent materials of Examples 3 to 6 in the same manner as in Example 1. The results are shown in FIG. FIG. 6 is a diagram showing the results of measuring the ML of the stress-stimulated luminescent material of Examples 3-6. It was shown that any stress-stimulated luminescent material emits stress well. It was also shown that the emission intensity was saturated when the load applied in Examples 3 to 6 exceeded a predetermined value. Further, FIG. 6 shows that the light emission value that is saturated can be controlled by adjusting the amount of transition metal to be added.

Example 7
A stress luminescent material was prepared in the same manner as in Example 1 except that any one of zinc oxide ZnO, silicon oxide SiO ₂ , tin oxide SnO _{2, and} hafnium oxide HfO ₂ was used instead of ZrO ₂ , and ML measurement was performed. . Specifically, ZnO was 0.0081 g, SiO ₂ was 0.0060 g, SnO ₂ was 0.0151 g, and HfO ₂ was 0.0210 g. The results are shown in FIG. FIG. 7 is a diagram showing the results of ML measurement in Examples 1 and 7. It was shown that higher stress luminescence can be obtained by using Hf as the transition metal. The load for ML measurement was 1000N.

Example 8
The relationship between the amount of Zr added and the stress emission was confirmed. Specifically, a stress-stimulated luminescent material was produced in the same manner as in Example 1 except that the amount of ZrO ₂ added was changed to various amounts. Specifically, in the composition formula of (1-x) (Sr _0.99 Eu _0.01 Al ₂ O ₄ ) · xZrO ₂ , x is 0, 0.005, 0.012, 0.024, 0.036. 0.048, 0.070, 0.1, 0.3, 0.5, 0.7, 0.9. The load for ML measurement was 1000N.

  The results are shown in FIG. FIG. 8 shows the relationship between the amount of Zr added and stress emission. The horizontal axis in FIG. 8 indicates the amount of Zr added, and the vertical axis indicates the stress emission. As shown in FIG. 8, the highest stress emission was exhibited when x was 2.5.

[Comparative Example 1]
SrCO ₃ , Al ₂ O ₃ , Eu ₂ O ₃ , and ZrO ₂ have a composition of (1-x) (Sr _0.99 Eu _0.01 Al ₂ O ₄ ) · xZrO ₂ (x = 0). Then, a predetermined amount was weighed (that is, zirconia oxide was not used). Specifically, SrCO ₃ was 0.2923 g, Al ₂ O ₃ was 0.2039 g, and Eu ₂ O ₃ was 0.0035 g.

  Next, the weighed raw materials were put in ethanol, mixed thoroughly using a ball mill, and then dried at 80 ° C. The obtained mixture was pulverized in a mortar and then calcined at 1400 ° C. for 4 hours in a reducing atmosphere (5% hydrogen-containing argon). The temperature increase and decrease were performed slowly at a rate of 2 ° C./min.

  Next, the material obtained after firing was pulverized to prepare a powder of a stress luminescent material. And XRD measurement, PL measurement, and ML measurement were performed about this powder by the same method as Example 1.

[Comparative Example 2]
CaCO ₃ , Al ₂ O ₃ , SiO ₂ , and Eu ₂ O ₃ are converted into a composition of (1-x) [Ca _0.99 Eu _0.01 Al ₂ Si ₂ O ₈ ] .xZrO ₂ (x = 0) Then, a predetermined amount was weighed. Specifically, CaCO ₃ was 0.0999 g, Al ₂ O ₃ was 0.1020 g, SiO ₂ was 0.0120 g, and Eu ₂ O ₃ was 0.0018 g.

  Next, the weighed raw materials were put in ethanol, mixed thoroughly using a ball mill, and then dried at 80 ° C. The obtained mixture was pulverized in a mortar and then calcined at 1400 ° C. for 4 hours in a reducing atmosphere (5% hydrogen-containing argon). The temperature increase and decrease were performed slowly at a rate of 2 ° C./min. Next, the material obtained after firing was pulverized to prepare a powder of a stress luminescent material. And ML measurement was performed by the same method as Example 1 about this powder.

[Comparative Example 3]
Strontium carbonate SrCO ₃ , aluminum oxide Al ₂ O ₃ , europium oxide Eu ₂ O ₃ , and zirconia ZrO ₂ were mixed with Sr _0.99-x Eu _0.01 Al ₂ O ₄ .xZrO ₂ (x = 0.05). A stress-stimulated luminescent material was synthesized and ML was measured in the same manner as in Example 1 except that the composition was used. Specifically, SrCO ₃ was 0.2775 g, Al ₂ O ₃ was 0.2039 g, Eu ₂ O ₃ was 0.0035 g, and ZrO ₂ was 0.0123 g. With this composition, the stress-stimulated luminescent material was in a state in which a non-solid transition metal was not included.

  Since the stress-stimulated luminescent material according to the present invention emits light by a mechanical external force, it can be used as an optical element that converts the mechanical external force into light. In addition, since the stress at which the light emission value is saturated can be adjusted, it can also be applied to a level sensor.

It is a figure which shows the result of having observed the stress light-emitting body obtained in Example 1 with the electron microscope. It is a figure which shows the measurement result of XRD of the stress light-emitting body obtained in Example 1 and Comparative Example 1. It is a figure which shows the measurement result of ML of the stress light-emitting body obtained in Example 1 and Comparative Examples 1 and 3. It is a figure which shows the measurement result of PL of the stress light-emitting body obtained in Example 1 and Comparative Example 1. It is a figure which shows the measurement result of ML of the stress light-emitting body obtained in Example 2 and Comparative Example 2. It is a figure which shows the measurement result of ML of the stress light-emitting body obtained in Examples 3-6. It is a figure which shows the measurement result of ML of the stress light-emitting body obtained in Example 1 and 7. It is a figure which shows the measurement result of ML of the stress light-emitting body obtained in Example 8.

Claims (12)

A stress luminescent material including a host material that emits light by receiving stress,
A transition metal (excluding rare earth metals), Si and Sn further comprising at least one element;
A stress-stimulated luminescent material, wherein at least a part of the element is contained in a matrix material in a non-solid solution state.   2. The stress-stimulated luminescent material according to claim 1, wherein the element is present in the form of particles on the surface of the base material.   The stress-stimulated luminescent material according to claim 1 or 2, wherein the content of the element is 0.1 mol% or more and 90 mol% or less.   Content of the said element is 10 mol% or more and 90 mol% or less, The stress light-emitting body of any one of Claims 1-3 characterized by the above-mentioned.   The stress luminescent material according to any one of claims 1 to 3, wherein the content of the element is 0.1 mol% or more and less than 10 mol%.   The element is at least one metal selected from the group consisting of Zr, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Hf, Nb, Mo, Ta, and W. The stress-stimulated luminescent material according to any one of claims 1 to 5.   The base material includes at least one compound selected from the group consisting of metal oxides, metal nitrides, and metal sulfides, and further includes a rare earth metal as an emission center. 2. The stress-stimulated luminescent material according to item 1.   The stress-stimulated luminescent material according to claim 7, wherein the metal oxide is at least one compound selected from the group consisting of aluminate and aluminosilicate.   The rare earth metal is an ion of at least one metal selected from the group consisting of Eu, Dy, La, Gd, Ce, Sm, Y, Nd, Tb, Pr, Er, Tm, Yb, Sc, Pm, Ho, and Lu. The stress-stimulated luminescent material according to claim 7, wherein   The composite material containing the stress light-emitting body of any one of Claims 1-9.   The level sensor containing the stress light-emitting body of any one of Claims 1-9. Mixing step of mixing raw materials in a composition in which a base material that emits light upon receiving stress is in a solid solution state, and further mixing at least one element of transition metal (excluding rare earth metals), Si and Sn When,
And a firing step of firing the mixture obtained by the mixing step.