JP7151746B2 - Light energy storage oxide and resin composition - Google Patents

Description

The present invention relates to light energy storage oxide and resin compositions.

2. Description of the Related Art Luminescent materials that store the energy of light such as ultraviolet rays and then emit visible light at around room temperature when externally stimulated are known.
Among them, a material that emits light upon being mechanically stimulated by an externally applied force (compression, displacement, friction, impact, etc.) is called a mechanoluminescent material.

As such a mechanoluminescent material, a mechanoluminescent material based on strontium aluminate has been disclosed. For example, europium as an activator is combined with a specific amount of at least one element selected from the group consisting of neodymium, dysprosium, and holmium as a co-activator. (See Patent Document 1).

In addition, as an application of the mechanoluminescent material, by applying a composition containing the mechanoluminescent material to a concrete structure, abnormal deformation and cracks that occur in the concrete structure can be sensed, and destruction of the concrete structure can be prevented. A use of prevention has been proposed (see Patent Document 2).

JP 2014-198758 A JP 2013-155062 A JP 2012-229934 A JP 2016-8945 A

In the application of the mechanoluminescent material described in Patent Document 2, assuming a bridge installed outdoors, light energy from sunlight can be stored during the daytime, but light energy is not added at night. It is preferable that the light energy stored during the day can be stored during the night, and that it can emit light even after a long period of time since sunset when an abnormality or crack occurs.
However, in a known mechanoluminescent material such as that described in Patent Document 1, after light energy is stored, the luminescence intensity against stress rapidly decreases with the passage of time. It can be said that the luminous intensity maintenance characteristics after energy storage are insufficient.

Also, it has been proposed to record the stress history by attaching a photosensitive film to a film containing a mechanoluminescent material (see Patent Document 3). In this case, since the excitation of the mechanoluminescent material can be performed only before attaching the photosensitive film, there is a problem that long-term use becomes difficult if the luminous intensity against stress decreases with the lapse of time.
Furthermore, a method has been proposed in which a photosensitive sheet and a filter sheet are laminated on a mechanoluminescent material so that excitation can be performed even after the photosensitive sheet is attached (see Patent Document 4). Even in this case, it is unrealistic to frequently excite the mechanoluminescent material when it is used in darkness such as a tunnel, and a mechanoluminescent material with the ability to store light energy for a long period of time is required.

Further, as a substance having the property of storing light energy and releasing energy by light emission, there has been a demand for investigation of a material capable of emitting light by stimulation other than mechanical stimulation.

In view of such circumstances, it is an object of the present invention to provide a light energy storage oxide having excellent emission intensity maintenance characteristics after energy storage.

The inventors of the present invention conducted various investigations on the composition of a compound having excellent emission intensity maintenance characteristics after energy storage. and magnesium ions is effective in improving the emission intensity maintenance characteristics, and arrived at the present invention.

That is, the light energy storage oxide of the present invention is a light energy storage oxide obtained by activating strontium aluminate with europium, and contains at least one selected from the group consisting of manganese ions, praseodymium ions and magnesium ions. characterized by containing

The optical energy storage oxide of the present invention contains at least one selected from the group consisting of manganese ions, praseodymium ions and magnesium ions as a co-activator in the optical energy storage oxide obtained by activating strontium aluminate with europium. is doing.
Various elements have been used as co-activators in light energy storage oxides obtained by activating strontium aluminate with europium. The present inventors have found that manganese ions, praseodymium ions and magnesium ions have an effect of improving emission intensity maintenance characteristics as an effect peculiar to manganese ions, praseodymium ions and magnesium ions. , which could not be expected by those skilled in the art.
By using at least one selected from the group consisting of manganese ions, praseodymium ions and magnesium ions as a co-activator, even after a long time has passed after storing light energy, high luminescence is obtained by stimulation. strength can be exhibited. Therefore, it can be suitably used for applications such as detecting anomalies in bridges as described above.

In the light energy storage oxide of the present invention, the total content of at least one selected from the group consisting of manganese ions, praseodymium ions and magnesium ions is 0.001 to 0.05 mol per 1 mol of strontium aluminate. Preferably.
When the content of at least one selected from the group consisting of manganese ions, praseodymium ions and magnesium ions is within the above range, the effect of improving the emission intensity maintenance characteristics is exhibited more favorably.

The optical energy storage oxide of the present invention preferably contains at least one selected from the group consisting of manganese ions and praseodymium ions.
Manganese ions and praseodymium ions are preferred because they have a particularly high effect of improving emission intensity maintenance characteristics.
Also, the optical energy storage oxide of the present invention preferably contains at least one selected from the group consisting of manganese ions and magnesium ions.
Manganese ions and magnesium ions are preferred because they are inexpensive raw materials.
Moreover, the optical energy storage oxide of the present invention preferably contains manganese ions.

The optical energy storage oxide of the present invention preferably emits light upon application of mechanical energy. Moreover, it is preferable to emit light by applying thermal energy. Moreover, it is preferable to emit light by application of electrical energy.
Optical energy storage oxides capable of emitting light by applying thermal or electrical energy in addition to or instead of mechanical stimulation, i.e., application of mechanical energy, find use in a variety of other applications. can do.
For example, it can be used as a sensor to detect dangers such as landslides and rising geothermal heat in mountainous areas. In order to monitor changes in mechanical energy and geothermal rise due to landslides, two or more types of strain sensing sensors (strain gauges, etc.) and temperature sensing sensors (thermometers) are usually required. By using objects, a single sensor can simultaneously monitor vibrations and geothermal rise, which are signs of landslides and volcanic eruptions.
In addition, this optical energy storage oxide can be used as a threshold visualization temperature sensor because it emits light above a certain temperature. In a chemical reaction, the reaction may go out of control, heat is generated, and an accident such as an explosion may occur. People around you may be unaware that you have an abnormal fever and fail to escape, resulting in a disaster. Therefore, there is a need for a technology that can visualize abnormal heat generation. If the reaction vessel is coated with this light energy storage oxide, it will emit strong light in the event of abnormal heat generation, and can notify the surroundings of danger.

The resin composition of the present invention is characterized by containing the light energy storage oxide of the present invention and a synthetic resin.
If the light energy storage oxide and the synthetic resin are mixed to form a resin composition, it can be used by applying it to a structure or the like in the form of a paint or the like.

ADVANTAGE OF THE INVENTION According to this invention, the optical energy storage oxide excellent in the luminescence intensity maintenance characteristic after energy storage can be provided.

FIG. 1 is a diagram showing the relationship between the luminous intensity retention rate _Ik and the type of co-activator ion in Examples 1-3 and Comparative Examples 1-15. FIG. 2 is a diagram showing the relationship between the light energy storage performance value _IST and the type of co-activator ion in Examples 1-3. FIG. 3 is a diagram showing the relationship between the emission intensity maintenance factor Ik and the contents of manganese ions and _europium ions in Examples 1 and 4 to 11 using manganese ions as co-activators. FIG. 4 is a diagram showing the relationship between the light energy storage performance value IST and the content of manganese ions and _europium ions in Example 1 and Examples 4 to 11 using manganese ions as co-activators. FIG. 5 is a diagram showing the temperature of the sample surface and the voltage value of the photomultiplier tube during heating.

The optical energy storage oxide of the present invention is described below.
The light energy storage oxide of the present invention is a light energy storage oxide obtained by activating strontium aluminate with europium, and contains at least one selected from the group consisting of manganese ions, praseodymium ions and magnesium ions. It is characterized by

In this specification, the light energy storage oxide is capable of storing the light energy possessed by the light (electromagnetic wave) by irradiating it with light, and emitting light and releasing the light energy by some stimulus. means oxide.
The wavelength of the light that is the source of the light energy is not particularly limited, but ultraviolet light (wavelength: 250-380 nm) or visible light in the blue region (wavelength: 380-450 nm) can be preferably used. Further, the wavelength of light when emitting light energy is preferably visible light (wavelength 380 to 780 nm). Visible light can be visually confirmed by a person (observer).

The stimulus for releasing the light energy stored in the light energy storage oxide includes stimuli such as application of mechanical energy, application of thermal energy, and application of electrical energy.
It is presumed that the storage and release of light energy by the light energy storage oxide formed by activating europium to strontium aluminate occurs by the following mechanism.
First, in the optical energy storage stage, the 4f electrons of Eu ²⁺ are excited to the 5d level by the irradiation of the excitation light, and the excited electrons at the 5d level move to the conduction band and move to the anion defect level. trapped, and holes are trapped in the cation defect level.
On the other hand, in the stage of emitting light energy, the excited electrons trapped in the anion defect level move to the conduction band again by the application of energy, and the holes trapped in the cation defect level move to the valence band, resulting in light emission. It is believed that light is emitted by recombination of electrons and holes at the center.
Based on this presumed mechanism, as a stimulus for releasing the light energy stored in the light energy storage oxide, it is possible to apply enough energy to move the excited electrons trapped in the anion defect level back to the conduction band. Any stimulus that can be provided is sufficient.

The optical energy storage oxide of the present invention preferably has an initial afterglow intensity of 0.02 cd/m ² or less. The initial afterglow intensity means the brightness when the circular pellet in which the optical energy storage oxide is dispersed is irradiated with the light of a fluorescent lamp of 200 lux and then kept in a dark place at 25° C. for 5 minutes. If the initial afterglow intensity exceeds 0.02 cd/m ² , there is a possibility that the luminous intensity maintenance characteristics will deteriorate.

The optical energy storage oxide of the present invention is based on strontium aluminate.
Strontium aluminate is a compound generally represented by _SrxAlyOz (0< _x , 0< _y , 0<z). Specific examples of strontium aluminate include, but are not limited to, various compounds such as SrAl ₂ O ₄ , SrAl ₄ O ₇ , Sr ₄ Al ₁₄ O ₂₅ , SrAl ₁₂ O ₁₉ , and Sr ₃ Al ₂ O ₆ . ing.
The base strontium aluminate is preferably monoclinic α-strontium aluminate. Monoclinic α-strontium aluminate is preferable for realizing mechanoluminescence derived from the piezoelectric effect due to strain because it has spontaneous polarization. In addition, it is difficult to achieve mechanoluminescence with hexagonal strontium aluminate.

The strontium aluminate is an alumina raw material and/or aluminum hydroxide containing at least one alumina selected from θ-alumina, κ-alumina, δ-alumina, η-alumina, χ-alumina, γ-alumina, and ρ-alumina, and strontium It is preferably synthesized from a source. Normally, "alumina" often refers to inexpensive and general-purpose α-alumina, but if so-called activated alumina such as θ-alumina and/or aluminum hydroxide is used as a raw material, a higher emission intensity can be obtained than when α-alumina is used. Because it can be achieved.

The light energy storage oxide of the present invention contains europium (Eu) ions as an activator. The amount of Eu ions contained in the light energy storage oxide is not particularly limited, but is 0.0001 to 0.05 mol, preferably 0.0005 to 0.03 mol, per 1 mol of strontium aluminate.
If the amount of Eu ions is too small, a sufficient emission intensity cannot be achieved, and if it is too large, the emission intensity maintenance characteristics will be lowered. The amount of Eu ions is more preferably 0.001 to 0.01 mol per 1 mol of strontium aluminate. Within this concentration range, it is easy to obtain a light energy storage oxide having both the emission intensity after the waiting time from excitation and the property of maintaining the emission intensity.

The light energy storage oxide of the present invention further contains at least one selected from the group consisting of manganese (Mn) ions, praseodymium (Pr) ions and magnesium (Mg) ions as a co-activator.
Compounds serving as manganese ion sources include manganese carbonate (MnCO ₃ ), manganese nitrate [Mn(NO ₃ ) ₂ ], manganese chloride (MnCl ₂ ), manganese oxide (MnO, MnO ₂ , Mn ₃ O ₄ , Mn ₂ O ₃ , MnO ₃ ), manganese acetate [Mn(CH ₃ COO) ₂ ], and the like.
Compounds serving as praseodymium ion sources include praseodymium carbonate [Pr ₂ (CO ₃ ) ₃ ], praseodymium nitrate [Pr(NO ₃ ) ₃ ], praseodymium chloride (PrCl ₃ ), praseodymium oxide (Pr ₂ O ₃ ), and praseodymium sulfate. [Pr ₂ (SO ₄ ) ₃ ] and the like.
Compounds serving as magnesium ion sources include magnesium carbonate (MgCO ₃ ), magnesium nitrate [Mg(NO ₃ ) ₂ ], magnesium chloride (MgCl ₂ ), magnesium oxide (MgO), magnesium acetate [Mg(CH ₃ COO) ₂ ] and the like.
The content of at least one selected from the group consisting of manganese ions, praseodymium ions and magnesium ions contained in the light energy storage oxide is not particularly limited, but the total content per mol of strontium aluminate is 0.001 to 0. It is preferably 0.05 mol, more preferably 0.001 to 0.03 mol. Further, it is more preferably 0.002 to 0.01 mol.

The optical energy storage oxide of the present invention preferably contains none of neodymium, dysprosium, and holmium as a co-activator. Patent Document 1 discloses that the mechanoluminescent intensity is increased by containing at least one element selected from the group consisting of neodymium, dysprosium, and holmium as a co-activator for strontium aluminate. However, it is preferable not to contain these elements because the emission intensity maintenance characteristics deteriorate when these elements are contained.
The optical energy storage oxide of the present invention preferably does not contain an alkali metal such as sodium as a co-activator. When an alkali metal such as sodium is contained, the initial afterglow intensity tends to increase, and the emission intensity maintenance characteristics tend to deteriorate.
The optical energy storage oxide of the present invention preferably contains no more than 0.4 mol of barium per 1 mol of strontium aluminate. When barium is contained in a certain amount or more, part or all of the crystal structure of the matrix strontium aluminate becomes hexagonal, which tends to weaken mechanoluminescent properties.

The light energy storage oxide of the present invention preferably has an average particle size of 1 to 10 μm. As the average particle size increases, the afterglow intensity tends to increase, the contrast of mechanoluminescence tends to decrease, and the visibility tends to deteriorate. Here, the average particle size means the 50% cumulative particle size on a volume basis obtained by measuring the particle size distribution with a laser diffraction/scattering particle size analyzer (manufactured by Microtrack Bell: model number Microtrac MT3300EX). do. The particle size can be adjusted by changing the amount of flux to be added, the firing temperature, the firing time, and the like.

A dispersing agent for enhancing the dispersibility of the particles may be further added to the raw material composition for optical energy storage oxide, which is the composition used for producing the optical energy storage oxide. Examples of dispersants include, but are not limited to, anionic surfactants and nonionic surfactants. Examples of anionic surfactants include ammonium polycarboxylate, and examples of nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene hydrogenated castor oil, polyoxyethylene mono fatty acid ester, polyoxyethylene sorbitan mono Fatty acid ester etc. are mentioned. These may be used alone or in combination of two or more.

A flux component may be further added to the raw material composition for optical energy storage oxide in order to improve the crystallinity of the particles. Examples of the flux component include, but are not limited to, compounds such as magnesium fluoride, aluminum fluoride, ammonium fluoride, ammonium bromide, ammonium iodide, ammonium sulfate, ammonium nitrate, and boric acid. These may be used alone or in combination of two or more.

Alternatively, the surface of the optical energy storage oxide may be coated with a silane coupling agent and heat-treated to improve the water resistance of the optical energy storage oxide.
The silane coupling agent preferably contains trialkoxysilane.
Further, the substituent other than the alkoxy group of the trialkoxysilane is preferably a hydrocarbon group having 3 or more carbon atoms.
According to the silane coupling agent as described above, hydrophobicity can be enhanced by the structure of the substituent other than the alkoxy group, so that it can be used as a light energy storage oxide with further excellent water resistance.

Moreover, the silane coupling agent is preferably a silane coupling agent having a fluoroalkyl group.
When the silane coupling agent has a fluoroalkyl group, the hydrophobicity can be enhanced, and therefore, it can be used as a light energy storage oxide with further excellent water resistance.

Also, the silane coupling agent is preferably 3,3,3-trifluoropropyltrimethoxysilane.
When 3,3,3-trifluoropropyltrimethoxysilane is used, it can be used as a light energy storage oxide with particularly excellent water resistance.

Alternatively, a light energy storage oxide and a phosphoric acid compound are mixed to prepare a slurry, which is pulverized to modify the surface of the optical energy storage oxide with the phosphoric acid compound. It may be a storage oxide.
A light energy storage oxide having such a surface treatment layer is also preferable because it becomes a light energy storage oxide having sufficient water resistance.

The phosphoric acid compound is not particularly specified, and both inorganic phosphates and organic phosphates can be used. Among them, water-soluble salts (including phosphoric acid) are preferred, specifically selected from the group consisting of ammonium phosphate, sodium phosphate, potassium phosphate, sodium polyphosphate, sodium hexametaphosphate, and phosphoric acid. At least one is preferred.

<Method for producing light energy storage oxide>
Although the method for producing the light energy storage oxide is not particularly limited, for example, the following methods can be mentioned.
Strontium aluminate as a base can be obtained by reacting alumina with a strontium compound.
Examples of strontium compounds include, but are not limited to, strontium carbonate, strontium oxide, strontium hydroxide, strontium halides (such as strontium chloride), strontium sulfate, strontium nitrate, and strontium hydrogen phosphate.
The europium compound that serves as the europium source is not particularly limited, and examples thereof include europium carbonate, europium oxide, europium chloride, europium sulfate, europium nitrate, and europium acetate.
Compounds serving as manganese ion sources are not particularly limited, and include manganese carbonate (MnCO ₃ ), manganese nitrate [Mn(NO ₃ ) ₂ ], manganese chloride (MnCl ₂ ), manganese oxide (MnO, MnO ₂ , Mn ₃ O ₄ ). , Mn ₂ O ₃ , MnO ₃ ), manganese acetate [Mn(CH ₃ COO) ₂ ], and the like.
Compounds serving as praseodymium ion sources include praseodymium carbonate [Pr ₂ (CO ₃ ) ₃ ], praseodymium nitrate [Pr(NO ₃ ) ₃ ], praseodymium chloride (PrCl ₃ ), praseodymium oxide (Pr ₂ O ₃ ), and praseodymium sulfate. [Pr ₂ (SO ₄ ) ₃ ] and the like.
Compounds serving as magnesium ion sources include magnesium carbonate (MgCO ₃ ), magnesium nitrate [Mg(NO ₃ ) ₂ ], magnesium chloride (MgCl ₂ ), magnesium oxide (MgO), magnesium acetate [Mg(CH ₃ COO) ₂ ] and the like.

Alumina, a strontium compound, a europium compound, and at least one selected from the group consisting of a manganese compound, a praseodymium compound and a magnesium compound are mixed to prepare a raw material composition for a light energy storage oxide, which further comprises a dispersant, A flux component may be added. A light energy storage oxide is obtained by firing a light energy storage oxide raw material composition in which these components are mixed.

The mixing means for the above components is not particularly limited, and known mixing means can be used. Among them, it is preferable to carry out wet mixing in the presence of a dispersing medium (for example, water) in a reaction vessel equipped with a pulverizer for stirring pulverizing media for efficient mixing. Here, the grinding medium agitating type pulverizer is one in which grinding media are put into a pulverizing vessel and agitated by rocking or rotating (rotating or revolving) the pulverizing vessel together with the material to be pulverized, or A pulverizer that directly agitates and pulverizes Examples of the grinding medium agitating pulverizer are not particularly limited, but one selected from the group consisting of planetary mills, bead mills, and vibration mills is preferable. Among them, a planetary mill involving rotation and revolution is particularly preferable. After wet mixing, the dispersion medium is removed and the mixture is dried to obtain a raw material composition for optical energy storage oxide.

Firing conditions are not particularly limited, and can be carried out according to a general firing method. For example, the obtained raw material composition for a light energy storage oxide is fired (for example, fired at 1000° C. or higher in a reducing atmosphere), and if necessary, the light energy storage oxide is obtained by pulverizing and sizing. can get.

Optical energy storage oxides are physically and chemically relatively stable under various environments, and emit light when stimulated by mechanical energy, thermal energy, electrical energy, or the like.

<Resin composition>
The light energy storage oxide of the present invention is preferably mixed with a synthetic resin and used as a resin composition. The resin composition containing the light energy storage oxide and synthetic resin of the present invention is the resin composition of the present invention.
As the synthetic resin, various resins such as thermosetting resin, room temperature setting resin, ultraviolet setting resin, and radiation setting resin can be used.
For example, at least selected from urethane resins, epoxy resins, acrylic resins, polyester resins, alkyd resins, silicone resins, fluorine resins, polyamide resins, vinyl chloride-vinyl acetate resins, chlorinated propylene resins, maleimide resins and modified products thereof One type is mentioned.
Among these resins, it is preferable to include an epoxy resin or a urethane resin.
When a resin composition is prepared using an epoxy resin or urethane resin as a synthetic resin and applied to a structure as an epoxy resin-based coating or a urethane resin-based coating, the light energy storage oxide can be used as a stress-stimulated luminescent material. It can be used as a mechanoluminescent paint used.
This mechanoluminescent paint has a clear correspondence between the magnitude of the load applied to the structure and the brightness of the emitted light, and is preferable because it facilitates determination of the degree of the load applied to the structure.

The synthetic resin is preferably a room temperature curable resin that can be cured at room temperature. If the resin is curable at room temperature, it can be applied to a large structure that is difficult to heat in a heating furnace or the like, and then cured to form a strong coating film.
In this specification, the room temperature is 25° C., and a resin that is cured by being left at 25° C. for 7 days is regarded as a room temperature curable resin.
Further, the synthetic resin itself may not be curable at room temperature, but may be a resin that becomes curable at room temperature by blending a curing agent or a curing catalyst.

In addition to the light energy storage oxide and the synthetic resin, the resin composition may contain solvents, dispersants, fillers, thickeners, surface conditioners or leveling agents, curing agents, cross-linking agents, pigments, and erasers as necessary. Additives such as a foaming agent, an antioxidant, a light stabilizer including an ultraviolet absorber, a flame retardant, a curing catalyst, a bactericidal agent, an antibacterial agent, and an adhesion imparting agent can be contained.

<Method for producing resin composition>
The resin composition containing the optical energy storage oxide of the present invention can be produced by mixing and dispersing the optical energy storage oxide, the synthetic resin, and, if necessary, other materials.
For example, the resin composition can be produced by using a mixer such as a conical blender, a V blender, a ribbon blender, a Henschel mixer, a Banbury mixer, or a triple roll to mix the raw materials.

<Application of resin composition>
The resin composition of the present invention containing the light energy storage oxide of the present invention is suitable for use in determining the degree of load applied to a structure by applying it to the structure as a paint.
The material and application of the structure whose degree of load is to be determined are not particularly limited, but suitable materials include ordinary paper, synthetic paper, epoxy resin, polyethylene, polyethylene terephthalate, polyester, polypropylene, Polymer materials such as polyvinyl chloride, natural or synthetic rubber, glass, ceramics, metals, wood, artificial or natural fibers, concrete, or combinations thereof, processed products thereof, and the like. In addition, suitable uses for structures include large structures such as buildings, viaducts, bridges, roads, railroad rails, columns, towers, pipelines and tunnels, floor materials, tiles, wall materials, block materials, pavement materials, Building materials such as wood, steel, and concrete; power transmission components such as gears and cams; exterior parts or built-in parts (engine parts, tires, belts, etc.) used in bicycles, automobiles, trains, ships, airplanes, etc.; , bearing retainers, bearings with optical sensors, fastening parts such as screws, bolts, nuts, washers, and the like.

Also, the structure to which the resin composition is applied may be a material that has an anisotropic breaking strength and has directions in which the breaking strength is stronger and weaker with respect to load.
Typical examples of materials having anisotropic breaking strength include wood, artificial fibers, and natural fibers. Some ceramics and metals also have anisotropy. Concrete is originally a material that does not have anisotropy, but since anisotropy is substantially present due to hardening conditions at the time of construction, etc., it is preferable to treat it as a material that has anisotropy.
Information about the direction of the load applied to the structure can be obtained by observing the luminescence pattern of the resin composition. Focusing on the brightness, the importance of the load applied to the structure can be judged. Even if the brightness of the emitted light itself is high, if it is determined from the pattern of the emitted light that the direction of the load is the direction in which the breaking strength is strong, there is no need to worry about the load so much. This eliminates the need to take excessive measures for maintenance, and facilitates maintenance of structures.
It is also desirable to observe the pattern of light emission over time. If it is possible to observe the pattern of luminescence over time and confirm that the pattern of luminescence has changed, it is possible to obtain information on whether or not structural destruction has occurred in the structure from the change in the pattern.
Since the resin composition containing the light energy storage oxide of the present invention is excellent in the property of maintaining the light emission intensity after light energy is stored, the pattern of light emission can be observed all night from sunset to sunrise in the next morning. , it is possible to accurately determine whether a structural failure has occurred in a structure or whether a problem has occurred in the structure.

When the resin composition of the present invention containing the light energy storage oxide of the present invention is used for the above applications, the resin composition is applied to the structure.
The method of applying the resin composition can be carried out by a method of applying a paint normally, and is not particularly limited, but it is spray coating, brush coating, roll coating, gravure coating, bar coating, and spin coating. method, dipping method, and the like can be used.
After applying the resin composition, the resin is preferably cured, preferably at room temperature. In addition, depending on the type of resin composition, it is desirable to fix the resin composition on the surface of the structure by performing heat curing, ultraviolet curing, or the like.
The coating thickness of the resin composition is desirably 1 to 500 μm.
When the coating thickness is less than 1 μm, the absolute amount of the light energy storage oxide is small, and the luminance of light emission is insufficient, which may make it difficult to measure the load. In addition, even if the coating thickness exceeds 500 μm, the brightness of light emission does not increase so much, which is not economical.

It is desirable to apply the resin composition to the structure generally over the entire surface of the structure and determine the degree of load occurring on the entire structure. However, when determining the degree of load on only a specific portion of the structure, the resin composition may be applied only to that specific portion.

When a load is applied to the structure coated with the resin composition and the coating film is distorted, the light energy storage oxide emits light due to the force exerted by the resin on the light energy storage oxide. . Specifically, the luminance of light emitted by the light energy storage oxide is measured, and the pattern of light emission is observed. Information on the amount of strain and the rate of change in the amount of strain can be obtained from the luminance, and information on the direction in which the load is applied can be obtained from the pattern of light emission.
The luminance of emitted light can be measured by taking a photograph or moving image of a structure emitting light and analyzing the photograph or moving image using image analysis software.
Specifically, image analysis software (for example, ImageJ: manufactured by the National Institutes of Health (NIH)) is used to calculate the brightness of the entire image or a part of the area to be measured, and the background brightness of that part is calculated. The subtracted value can be used as the luminance of mechanoluminescence.

Observation of the light emission pattern is performed visually by an observer so as to recognize a characteristic light emission pattern. In doing so, if the direction in which the load is applied and the strength of the structure are known, the relationship between the pattern of light emission and the direction in which the load is applied and the strength of the structure can be obtained by observing them with reference to them. It is desirable to try to find out the sex.

When measuring the luminance and observing the pattern of light emission periodically after the structure is installed without intentionally applying a load, information on the load applied to the structure at the place where the structure is installed should be collected periodically. can be recorded effectively.
In this case, it is desirable to periodically take pictures (pictures and/or videos) at the place where the structure is installed and keep records.

In addition, when intentionally applying a load to a structure, use a device for strength testing of materials (tensile tester, compression tester, bending tester, etc.) to apply a load to the structure and observe the state of light emission. By doing so, it is possible to measure the relationship between the value of the load applied to the material and the luminescence behavior.
Conditions for applying a load can comply with the JIS regulations regarding materials for structures.

Other uses of the resin composition of the present invention containing the light energy storage oxide of the present invention include storage batteries, valve seats, water pipes, sprinkler heads, and non-aqueous electrolyte secondary batteries injected with electrolyte or polymer electrolyte. It is expected to detect liquid leakage and the like. In addition, the stress distribution in the adhesive layer of the adhesive containing the light energy storage oxide can be visualized, and cracks in the adhesive can be grasped.
In addition, examples of the use of the resin composition as an ink composition, bonding agent, or surface coating agent include bonding adhesives used in financial institutions, public institutions, credit card companies, the distribution industry, etc. Mailing items such as pressure-bonded postcard sheets containing mechanoluminescent materials; Furniture such as chairs and beds; Building materials such as flooring, tiles, walls, blocks, paving materials, wood, steel, concrete, etc.; operating devices for operating audio devices, air conditioners, etc.; input devices such as home electric appliances, mobile devices, electronic computers, etc.; image storage means such as digital cameras, CCD cameras, films, photographs, videos, etc. is mentioned.

Alternatively, the light energy storage oxide of the present invention may be used as a composite material with other inorganic materials or organic materials, and then molded to produce a light-emitting body. For example, a luminous body can be obtained by mixing or embedding the optical energy storage oxide of the present invention in an organic material such as resin or plastic in an arbitrary ratio to form a composite material. When a mechanical stimulus such as an external force is applied to this luminous body, it emits light due to the stimulus.

The following examples are provided to illustrate the invention in detail. However, the present invention is not limited by these examples.

Example 1 (Preparation of light energy storage oxide using manganese ions as co-activator)
Strontium carbonate (manufactured by Sakai Chemical Industry Co., Ltd. SW-K, 28.11 g), europium oxide (manufactured by Shin-Etsu Chemical Co., Ltd., 0.3586 g), manganese carbonate (manufactured by Chuo Denki Kogyo Co., Ltd., C2-SP, 0.060 g ), aluminum oxide (RA-40, 19.9561 g, manufactured by Iwatani Chemical Industry Co., Ltd.), and boric acid (0.073 g, manufactured by U.S. Borax) were weighed and added to water (90 mL). Thereafter, 3 mm diameter alumina balls (SSA-999W, 190 g, manufactured by Nikkato Co., Ltd.) were used as grinding media, and a slurry was obtained by dispersing, pulverizing, and mixing using a planetary ball mill. The resulting slurry was evaporated to dryness at 130°C. The resulting solid matter was pulverized in a mortar to obtain a powdery raw material composition for light energy storage oxide. Next, 40 g of the raw material composition for optical energy storage oxide is filled in an alumina crucible, heated to 1200° C. at a rate of 200° C./hour in a reducing atmosphere (nitrogen containing 2% hydrogen), and held for 4 hours. , 200° C./hour to room temperature.
The baked product thus obtained was pulverized in an alcohol solvent using a planetary ball mill, filtered, and dried to obtain a light energy storage oxide powder.
The manganese ion content is 0.0025 mol per mol of strontium aluminate.

Example 2 (Preparation of light energy storage oxide using praseodymium ion as co-activator)
Light energy was applied in the same manner as in Example 1, except that the manganese carbonate was changed to praseodymium oxide (manufactured by Nikki Co., Ltd.) to adjust the composition so that the praseodymium ion content was 0.0025 mol per 1 mol of strontium aluminate. A stock oxide was obtained.

Example 3 (Preparation of light energy storage oxide using magnesium ions as co-activator)
Example 1, except that manganese carbonate was replaced with magnesium carbonate (GP-30N manufactured by Kojima Chemical Co., Ltd.) so that the magnesium ion content was 0.0025 mol per 1 mol of strontium aluminate. A light energy storage oxide was obtained by the same method.

Comparative Example 1 (without co-activator)
A light energy storage oxide was obtained in the same manner as in Example 1, except that the composition was changed so as not to contain manganese carbonate.

Comparative Example 2 (using sodium ions as co-activator)
Example 1 except that manganese carbonate was changed to sodium hydroxide (reagent manufactured by Wako Pure Chemical Industries, Ltd.) to adjust the composition so that the sodium ion content was 0.0025 mol per 1 mol of strontium aluminate. A light energy storage oxide was obtained by the same method.

Comparative Example 3 (using zinc ions as a co-activator)
Same as Example 1, except that manganese carbonate was changed to zinc oxide (fine zinc oxide manufactured by Sakai Chemical Industry Co., Ltd.) so that the zinc ion content was 0.0025 mol per 1 mol of strontium aluminate. A light energy storage oxide was obtained by the same method.

Comparative Example 4 (using copper ions as a co-activator)
Example 1, except that manganese carbonate was changed to copper chloride (reagent special grade, manufactured by Wako Pure Chemical Industries, Ltd.) to adjust the composition so that the copper ion content was 0.0025 mol per mol of strontium aluminate. A light energy storage oxide was obtained by the same method.

Comparative Example 5 (using thulium ion as a co-activator)
The same as in Example 1 except that manganese carbonate was changed to thulium oxide (reagent manufactured by Wako Pure Chemical Industries, Ltd.) to adjust the composition so that the content of thulium ions was 0.0025 mol per mol of strontium aluminate. A light energy storage oxide was obtained by the method.

Comparative Example 6 (Using holmium ions as a co-activator)
The same method as in Example 1 was repeated except that the composition was adjusted by replacing manganese carbonate with holmium oxide (manufactured by Shin-Etsu Chemical Co., Ltd.) so that the content of holmium ions was 0.0025 mol per mol of strontium aluminate. A light energy storage oxide was obtained.

Comparative Example 7 (Using dysprosium ion as a co-activator)
Example 1 except that the composition was adjusted by replacing manganese carbonate with dysprosium oxide (manufactured by Shin-Etsu Chemical Co., Ltd.) so that the content of dysprosium ions was 0.0025 mol per mol of strontium aluminate. A light energy storage oxide was obtained by the same method as

Comparative Example 8 (using tin ions as a co-activator)
Manganese carbonate was changed to tin chloride dihydrate (reagent manufactured by Wako Pure Chemical Industries, Ltd.) to adjust the composition so that the tin ion content was 0.0025 mol per 1 mol of strontium aluminate. A light energy storage oxide was obtained in the same manner as in Example 1.

Comparative Example 9 (using neodymium ions as a co-activator)
In the same manner as in Example 1, except that the composition was adjusted by replacing manganese carbonate with neodymium oxide (manufactured by Shin-Etsu Chemical Co., Ltd.) so that the content of neodymium ions was 0.0025 mol per mol of strontium aluminate. A light energy storage oxide was obtained.

Comparative Example 10 (using calcium ions as a co-activator)
Same as Example 1, except that manganese carbonate was changed to calcium carbonate (CW-S manufactured by Sakai Chemical Industry Co., Ltd.) to adjust the composition so that the content of calcium ions was 0.0025 mol per mol of strontium aluminate. A light energy storage oxide was obtained by the same method.

Comparative Example 11 (using barium ions as a co-activator)
Same as Example 1, except that the composition was adjusted by replacing manganese carbonate with barium carbonate (BW-K manufactured by Sakai Chemical Industry Co., Ltd.) so that the content of barium ions was 0.0025 mol per mol of strontium aluminate. A light energy storage oxide was obtained by the same method.

Comparative Example 12 (using potassium ions as a co-activator)
Same as Example 1, except that manganese carbonate was changed to potassium carbonate (reagent manufactured by Wako Pure Chemical Industries, Ltd.) to adjust the composition so that the content of potassium ions was 0.0025 mol per mol of strontium aluminate. A light energy storage oxide was obtained by the method.

Comparative Example 13 (using silicon ions as a co-activator)
Example except that the composition was adjusted by replacing manganese carbonate with silicon oxide (Sciqas (registered trademark) manufactured by Sakai Chemical Industry Co., Ltd.) so that the silicon ion content was 0.0025 mol per mol of strontium aluminate. A light energy storage oxide was obtained in the same manner as in 1.

Comparative Example 14 (using gallium ions as a co-activator)
The same method as in Example 1 was repeated except that the composition was adjusted by replacing manganese carbonate with gallium oxide (manufactured by Dowa Kogyo Co., Ltd.) so that the content of gallium ions was 0.0025 mol per mol of strontium aluminate. An energy storage oxide was obtained.

Comparative Example 15 (using indium ions as a co-activator)
Same as Example 1 except that manganese carbonate was changed to indium oxide (reagent manufactured by Wako Pure Chemical Industries, Ltd.) to adjust the composition so that the indium ion content was 0.0025 mol per 1 mol of strontium aluminate. A light energy storage oxide was obtained by the method.

Examples 4 to 11 (change in content of europium ions and manganese ions)
A light energy storage oxide was prepared in the same manner as in Example 1, except that the composition was adjusted by changing the amount of europium oxide and/or manganese carbonate so that the contents of europium ions and manganese ions were as shown in Table 3. Obtained.

Comparative Example 16 (Change in content of europium ions and barium ions)
A light energy storage oxide was obtained in the same manner as in Comparative Example 11 except that the composition was adjusted by changing the amounts of europium oxide and barium carbonate so that the contents of europium ions and barium ions were as shown in Table 4.

The optical energy storage oxides obtained in each example and each comparative example were evaluated by the following methods.
(Evaluation of luminescence properties by application of mechanical energy)
To make circular pellets, light energy storage oxide powder and epoxy resin were added to a transparent plastic cell in a weight ratio of 2:3, mixed by hand, and cured by heating. 365 nm light from a UV lamp (AS ONE Handy UV Lamp SLUV-4) was irradiated for 1 minute on the cured circular pellet, left in the dark at 25 ° C for 5 minutes, and then tested with a desktop precision universal testing machine (Shimadzu Corporation , AGS-X), and the emitted light at that time was detected with a photomultiplier tube module (manufactured by Hamamatsu Photonics, H7827-011). The voltage value of the photomultiplier tube module at this time was set to _I5min .
Furthermore, the circular pellets prepared by the above method were irradiated with 365 nm light from a UV lamp (AS ONE Handy UV Lamp SLUV-4) for 1 minute, left in the dark at 25 ° C. for 24 hours, and then measured in the same manner. The voltage value of the tube module was taken as _I24h .
The emission intensity maintenance characteristic is represented by the following formula (1).
Emission intensity maintenance rate _{Ik (%) = (I24h/I5mim ) x} 100 (1)
In addition, it is preferable that the _luminous intensity is high after being left in the dark and that the luminous intensity is maintained well. A light energy storage performance value _IST was used.
Optical energy storage performance value I _ST =I _24h ×(I _24h /I _5mim ) × 100 (2)
Tables 1 and 3 and FIGS. 1 and 3 show the evaluation results of the emission intensity maintenance rate in each example and comparative example. Tables 2 and 3 and FIGS. 2 and 4 show the evaluation results of optical energy storage performance in the examples.

(Measurement of average particle size)
For the optical energy storage oxide obtained in each example and each comparative example, the particle size distribution was measured by a laser diffraction/scattering particle size analyzer (manufactured by Microtrack Bell: model number Microtrac MT3300EX), and the volume-based A 50% cumulative particle size was calculated.
Tables 1 and 3 show the calculated 50% cumulative particle size as the average particle size.

FIG. 1 shows the relationship between the luminescence intensity retention rate _Ik and the type of co-activator ion in Examples 1-3 and Comparative Examples 1-15.
From FIG. 1, in Examples 1 to 3 using manganese ions, praseodymium ions, or magnesium ions as co-activators, the emission intensity maintenance rate I _k It turns out to be excellent.
Further, FIG. 2 shows the relationship between the light energy storage performance value I _ST and the type of co-activator ion of Examples 1 to 3, which were shown to be excellent in the luminous intensity maintenance rate I _k in FIG. there is From FIG. 2, it can be seen that Examples 1 and 2, in which manganese ions or praseodymium ions are used as co-activators, are particularly excellent in light energy storage performance value _IST .

FIG. 3 is a diagram showing the relationship between the emission intensity maintenance factor Ik and the contents of manganese ions and _europium ions in Examples 1 and 4 to 11 using manganese ions as co-activators. It was confirmed that the luminous intensity maintenance characteristics were excellent for each content.
FIG. 4 is a diagram showing the relationship between the light energy storage performance value IST and the content of manganese ions and _europium ions in Example 1 and Examples 4 to 11 using manganese ions as co-activators.
Regarding the content of manganese ions and europium ions when manganese ions are used as a co-activator, per mol of strontium aluminate, (manganese ions, europium ions) = (0.0025 mol, 0.001 mol), ( 0.0025 mol, 0.01 mol), (0.005 mol, 0.01 mol), (0.01 mol, 0.01 mol) in the case of combinations such as luminous intensity maintenance rate I _k and light energy It can be seen that the storage performance value _IST increases.
From this, light energy is particularly preferable when the manganese ion content is 0.002 to 0.01 mol and the europium ion content is 0.001 to 0.01 mol per 1 mol of strontium aluminate. It can be said that it becomes a storage oxide.

In Comparative Example 16, manganese ions and praseodymium ions were used as co-activators at the same activator concentration as in Example 7, which had the lowest emission intensity maintenance ratio _Ik among Examples 1 and 4 to 11 shown in Table 3. Or, it is an example of evaluation results when ions other than magnesium ions are used. Specifically, this is an example of using barium ions as a co-activator. Table 4 shows the evaluation results.
Among the co-activators used in Comparative Examples 2 to 15 in Table 1, the barium ion was the ion with the highest emission intensity maintenance rate _Ik .
Since the emission intensity retention rate _Ik and the light energy storage performance value _IST of Comparative Example 16 are significantly inferior to those of Example 7, manganese ions, praseodymium ions, or magnesium ions were used as co-activators at the same activator concentration. was shown to be a particularly preferable light energy storage oxide when

(Evaluation of luminescence properties by application of thermal energy)
The luminescence due to thermal energy of the obtained powder was measured by the following method. The powder of Example 1 was placed in a quartz sample container, placed on the sample stage of a microscope cooling and heating stage (LINKAM 10002L), and a K-type thermocouple was placed on the sample surface to measure the temperature of the sample surface. Then, 365 nm light from a UV lamp (AS ONE Handy UV Lamp SLUV-4) was irradiated from above the upper glass window for 10 minutes, left at 25 ° C. in the dark for 3 hours, and then heated to 25 ° C. to 300 ° C. The temperature was raised at 10° C./min, and light emission during the temperature rise was detected with a photomultiplier tube module (manufactured by Hamamatsu Photonics, H7827-011).
FIG. 5 is a diagram showing the temperature of the sample surface and the voltage value of the photomultiplier tube during heating.
It can be seen that the light is emitted at around 80° C. even after being left in the dark for 3 hours.

(Evaluation of initial afterglow intensity)
The initial afterglow intensity of the obtained powder was measured by the following method. A circular pellet prepared using the powder of Example 1 was irradiated with light of a fluorescent lamp of 200 lux, and the luminance when held in a dark place at 25 ° C. for 5 minutes was measured with a luminance meter (BM-9A manufactured by Topcon Technohouse). Measured at The luminance at this time was 0.02 cd/m ² . Comparative Examples 2 and 9 were measured in the same manner and found to be 0.04 cd/m ² and 0.1 cd/m ² , respectively.

Claims (9)

A light energy storage oxide obtained by activating strontium aluminate with europium, wherein at least one selected from the group consisting of manganese ions, praseodymium ions and magnesium ions is added in a total amount of 0.001 per mol of strontium aluminate Contains ~0.05 mol,
The europium ion content is 0.0001 to 0.05 mol per 1 mol of strontium aluminate,
A light energy storage oxide characterized by having an average particle size of 1 to 10 μm. 2. The optical energy storage oxide according to claim 1 , containing at least one selected from the group consisting of manganese ions and praseodymium ions. 2. A light energy storage oxide according to claim 1 , containing at least one selected from the group consisting of manganese ions and magnesium ions. 4. The light energy storage oxide according to any one of claims 1 to 3, which contains manganese ions. 5. The optical energy storage oxide according to any one of claims 1 to 4, characterized by having an average particle size of 1 to 2.64 μm. 6. The optical energy storage oxide according to any one of claims 1 to 5, which emits light upon application of mechanical energy. 7. The optical energy storage oxide according to any one of claims 1 to 6, which emits light upon application of thermal energy. 8. The optical energy storage oxide according to any one of claims 1 to 7, which emits light upon application of electrical energy. A resin composition comprising the light energy storage oxide according to any one of claims 1 to 8 and a synthetic resin.

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