JP3273317B2 - Stress-stimulated luminescent material and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a novel stress-stimulated luminescent material which emits light when a mechanical external force is applied thereto, and a method for producing the same.

[0002]

2. Description of the Related Art Hitherto, a phenomenon in which a substance emits visible light near room temperature when a substance is stimulated from the outside is well known as a trivol luminescence phenomenon. Substances that cause such a fluorescent phenomenon, that is, fluorescent materials, include lighting lamps such as fluorescent lamps, CRTs (Cathode Ray Tubes),
It is used as a so-called cathode ray tube. External stimuli that cause this fluorescence phenomenon are usually given by ultraviolet rays, electron beams, X-rays, radiation, electric fields, chemical reactions, and the like. unknown.

[0003]

SUMMARY OF THE INVENTION The present inventors have developed a material which emits light efficiently by mechanical stimulation such as external force, unlike stimulation by ultraviolet rays, electron beams, X-rays, radiation, electric fields, chemical reactions and the like. As a result of long-term research on, as a result, in particular, not only is it effective to add a luminescent center to a host material having a melilite-type structure, but also found an appropriate addition amount and an appropriate doping method of the luminescent center. The efficiency of converting mechanical energy into light energy has been significantly improved. The present invention is based on such knowledge, and its technical problem is that it has been known that light is efficiently emitted by mechanical stimulation by external force such as frictional force, shear force, impact force, and pressure. Another object of the present invention is to provide a novel stress-stimulated luminescent material of a different type from the conventional one and a method of manufacturing the same.

[0004]

Means for Solving the Problems The stress-stimulated luminescent material of the present invention for solving the above-mentioned problems is characterized in that an electron excited by mechanical energy returns to a ground state in a base material composed of an oxide having a melilite structure. And a luminescent center made of at least one kind of rare earth or transition metal which emits light. Further, the method for producing a stress-stimulated luminescent material according to the present invention is characterized in that a base material composed of an oxide having a melilite structure has a rare-earth or transition metal that emits light when electrons excited by mechanical energy return to a ground state.
After adding and mixing at least 0.001 to 20 wt% of luminescent centers composed of more than one kind,
It is characterized by firing at 0 to 1800 ° C. and doping the emission center.

The above-mentioned oxides having a melilite structure include CaYAl ₃ O ₇ , Ca ₂ Al ₂ SiO ₇ ,
Ca ₂ (Mg, Fe) Si ₂ O ₇ , Ca ₂ B ₂ S
iO ₇ , CaNaAlSi ₂ O ₇ , Ca ₂ MgSi
₂ O ₇ , (Ca, Na) ₂ (Al, Mg) (Si,
Al) ₂ O ₇ , and Ca ₂ (Mg, Al) (A
l, Si) SiO _7, and any of them or a mixture of a plurality of them can be used as a base material.

According to the present invention, it is possible to provide a stress-stimulated luminescent material capable of efficiently emitting light by mechanical stimulation by an external force such as a frictional force, a shearing force, an impact force, and a pressure, and a method of manufacturing the same. it can.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The stress-stimulated luminescent material according to the present invention is constituted by adding a luminescent center to a base material. The base material is particularly a substance having a melilite type structure, more specifically, a melilite type structure. This is based on the result of confirming that a material composed of an oxide having a structure is suitable and that the luminescence intensity when using the material is higher than that of other substances. for that reason,
The host material is naturally selected from the above-mentioned oxides having the melilite structure, and the oxides having the melilite structure group are, in particular, CaYAl ₃ O ₇ or Ca ₂ A.
l ₂ SiO ₇ , Ca ₂ (Mg, Fe) Si ₂ O
₇ , Ca ₂ B ₂ SiO ₇ , Ca ₂ BeSi ₂ O
₇ , CaNaAlSi ₂ O ₇ , Ca ₂ Al (Al,
Si) ₂ O ₇ , Ca ₂ MgSi ₂ O ₇ , (Ca,
Na) ₂ (Al, Mg) (Si, Al) ₂ O ₇ , C
a ₂ (Mg, Al) (Al, Si) SiO ₇ as a main component is suitable.
₂ Al ₂ SiO ₇ or Ca ₂ MgSi ₂ O ₇ are suitable.

Further, when a luminescent center is added to the above-mentioned base material, the luminescent intensity can be remarkably improved.
In order to dope the luminescent center, a material to be the luminescent center is mixed well with the base material, and then 600 to 1 in a reducing atmosphere.
This is achieved by firing at a high temperature of 800 ° C. for 30 minutes or more. Further, by adding a flux such as boric acid, the light emission characteristics can be improved.

[0009] Sc, Y,
La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, T
rare earth ions of b, Dy, Ho, Er, Tm, Yb, Lu, and Ti, Zr, V, Cr, Mn, Fe, Co,
It is suitable to use one or more of transition metal ions of Ni, Cu, Zn, Nb, Mo, Ta, and W, but the optimum emission center differs depending on the base material. For example, if the host material is Ca ₂ Al ₂ SiO ₇ or Ca ₂
In the case of MgSi ₂ O ₇ , Ce is effective. The addition amount of the material serving as the emission center can be selected in the range of 0.001 to 20 wt%. When the content is less than 0.001 wt%, the emission intensity is insufficiently improved. On the other hand, when the content is more than 20 wt%, the crystal structure of the base material cannot be maintained, and the luminous efficiency is lowered to be suitable for practical use. Absent.

The luminous intensity of the above-mentioned luminescent material depends on the nature of the mechanical force acting as an excitation source. Generally, the greater the applied mechanical force, the stronger the luminous intensity. Therefore, by measuring the light emission intensity, the mechanical acting force applied to the material can be known. As a result, the stress state applied to the material can be detected in a non-contact manner, and the stress state can be visualized. Therefore, application in a stress detector and other wide fields can be expected.

[0011]

Examples of the present invention will be described below. Example 1 In order to investigate the stress-stimulated luminescent properties of the stress-stimulated luminescent material according to the present invention, the powder sample was buried in an epoxy resin, pelletized, and the following measurements were performed. The test powder sample was Ca ₂ Al ₂ SiO ₇ which is a base material.
And 0.05% by weight of Ce ₂ O _{3 serving} as an emission center;
10 wt% of boric acid as a flux is added, and the mixture is heated at 1300 ° C. in a reducing atmosphere (Ar + H ₂ , 5%).
This was produced by powdering the stress-stimulated luminescent material obtained by baking for 4 hours.

FIG. 1 shows the pellet sample (Ca ₂
The stress luminescence behavior (time-dependent change) when a mechanical force of 1000 N is applied to Al ₂ SiO ₇ : Ce) by a vice is shown. The above sample (Ca ₂ Al ₂ SiO ₇
: Ce) emitted intense blue light that could be confirmed with the naked eye. FIG. 2 shows the pellet-shaped sample (Ca
₂ Al ₂ SiO _7: shows the results of examining the stress dependence of the emission intensity of Ce). According to this result, the luminescence intensity was dependent on the stress, and the luminescence intensity increased as the load increased. From this, it was found that the magnitude of the stress can be evaluated by measuring the emission intensity. The same tendency as in FIGS. 1 and 2 was obtained with other oxides having a melilite structure.

Example 2 In the same manner as in Example 1 (Sample No. 1), CaYAl ₃ O ₇ (Sample No. 2), C
a ₂ (Mg, Fe) Si ₂ O ₇ (sample No. 3),
Ca ₂ B ₂ SiO ₇ (Sample No. 4), CaNaA
lSi ₂ O ₇ (sample No. 5), Ca ₂ MgSi ₂
O ₇ (sample No. 6), (Ca, Na) ₂ (Al, M
g) (Si, Al) ₂ O ₇ (sample No. 7), Ca ₂
(Mg, Al) (Al, Si) SiO ₇ (Sample NO.
In 8), a luminescent material containing 0.05 mol% of Ce ions was prepared, and the luminescence intensity was measured. Table 1 shows the results together with Example 1 (Sample No. 1).

[0014]

[Table 1]

[0015]

As described above in detail, according to the present invention, a new stress-stimulated luminescent material which emits light effectively by a mechanical external force such as frictional force, shear force, impact force, and pressure, and a method of manufacturing the same are provided. Can be obtained, and the mechanical external force can be directly converted to light by the light emission of the material itself acting on it. it can.

[Brief description of the drawings]

FIG. 1 shows a pellet sample (Ca ₂ Al ₂ ) according to the present invention.
SiO 7: _Ce) to a graph showing the stress light-emitting behavior when multiplied by the mechanical action force.

FIG. 2 shows a pellet sample (Ca ₂ Al ₂ ) according to the present invention.
SiO 7: is a graph showing the results of examining the stress dependence of the emission intensity of _Ce).

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI C09K 11/64 CPR C09K 11/64 CPR 11/80 CPM 11/80 CPM (56) References JP-A-2-38484 (JP, A) JP-A-51-74990 (JP, A) JP-A-48-46582 (JP, A) JP-A-10-172459 (JP, A) JP-A-2000-212557 (JP, A) JP-A-2000-34479 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C09K 11/00 C09K 11/08 C09K 11/59 C09K 11/60 C09K 11/63 C09K 11/64 C09K 11/80 WPI (DIALOG)

Claims (2)

(57) [Claims] 1. A CaYAl having a melilite type structure₃ O₇ ,
Ca₂ Al₂ SiO₇ , Ca₂(Mg, Fe) Si
₂ O₇ , Ca₂ B₂ SiO₇ , CaNaAlSi
₂ O ₇ , Ca₂ MgSi₂ O₇ , (Ca, Na)
₂ (Al, Mg) (Si, Al)₂ O₇ , And C
a₂ (Mg, Al) (Al, Si) SiO₇ Oxide of
The base material consisting of one or more of
Occurs when the electrons excited by the energy return to the ground state.
Luminescence consisting of one or more luminous rare earths or transition metals
A stress-stimulated luminescent material having a center added. 2. CaYAl having a melilite type structure₃ O₇ ,
Ca₂ Al₂ SiO₇ , Ca₂(Mg, Fe) Si
₂ O₇ , Ca₂ B₂ SiO₇ , CaNaAlSi
₂ O ₇ , Ca₂ MgSi₂ O₇ , (Ca, Na)
₂ (Al, Mg) (Si, Al)₂ O₇ , And C
a₂ (Mg, Al) (Al, Si) SiO₇ Oxide of
The base material consisting of one or more of
Occurs when the electrons excited by the energy return to the ground state.
Luminescence consisting of one or more luminous rare earths or transition metals
Add and mix the center in the range of 0.001-20 wt%
And then fired at 600-1800 ° C in a reducing atmosphere
Stress-luminescent material characterized by doping the luminescent center
Method of manufacturing the ingredients.