JP2005350657A - Phosphor and plasma display panel using the phosphor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a phosphor which does not suffer easily degradation with time by its operations for various purposes and can maintain a high luminescent efficiency regardless of the operation time length and to provide a PDP (plasma display panel) using this phosphor. <P>SOLUTION: G phosphor 250G has zinc silicate as its base material and a phosphor main part having manganese (Mn) as its activity-adding material. To this phosphor main part, at least one element of titanium (Ti), zirconium (Zr) and hafnium (Hf) or at least one element of molybdenum (Mo) and tungsten (W) is added. In this way, by adding one of the mentioned elements, G phosphor 250G has little segregation of silicon (Si) on the surface of particles and nearby thereof and has a high crystallinity. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a phosphor and a plasma display panel using the phosphor, and more particularly to a zinc silicate phosphor activated by manganese.

The manganese-activated zinc silicate phosphor used in plasma display panels (hereinafter referred to as “PDP”) and fluorescent lamps (hereinafter referred to as “ZSM phosphor”) has a high color. It is often used as a green phosphor having high purity and high luminous efficiency.
Although the ZSM phosphor has a base material whose general formula is represented by Zn ₂ SiO ₄ , the atomic ratio (Zn / Si) = 1.5 in which silicon is in excess of the stoichiometric composition It is considered desirable to have a composition (see, for example, Non-Patent Document 1). In this document, in the stoichiometric composition, the atomic ratio (Zn / Si) in Zn ₂ SiO ₄ is “2”, whereas in the case of a phosphor used in a PDP, a fluorescent lamp, etc., the above stoichiometric composition However, it is said that it is necessary to obtain high luminous efficiency by making silicon excessive.

  As a method for producing a ZSM phosphor, a silicon source typified by silicon dioxide, a zinc source typified by zinc oxide, and a manganese source typified by manganese carbonate are used in comparison with the stoichiometric composition for the above reasons. A method is adopted in which the silicon components are mixed at a blending ratio at which the silicon component is slightly excessive, and heat treatment (firing) is performed at about 1200 ° C. in the air or in a reducing atmosphere (see, for example, Non-Patent Document 1). In addition, since the heat treatment is performed in the high temperature atmosphere as described above, the zinc component is easily sublimated from the surface in the manufacturing process, and as a result, the composition of the surface of the phosphor particles is compared with the composition when the whole particles are averaged. In particular, silicon is in an excessive state. And it is thought that a part of silicon in the particle | grain surface of ZSM fluorescent substance exists as silicon dioxide (for example, refer nonpatent literature 1).

By the way, the ZSM phosphor has a problem of deterioration over time such that the light emission efficiency is lowered as the lighting time elapses depending on use conditions. In order to deal with such problems, for example, when a use lamp is used as a fluorescent lamp, a method of forming a silicon nitride compound layer on the surface of phosphor particles has been proposed (see Patent Document 1). As another method, there has been proposed a method in which tungsten oxide is added at the time of manufacturing a phosphor, thereby suppressing deterioration of the phosphor with time (see Patent Documents 2 and 3).
Phosphor Society, “Phosphor Handbook” (pp. 219-220), Ohmsha, December 25, 1987 Japanese Patent Publication No. 06-62944 Japanese Patent No. 2811485 U.S. Pat. No. 4,728,459

  However, the conventional techniques including the proposals in the above-mentioned Patent Documents 1 to 3 achieve both high luminous efficiency in the initial stage of driving and suppression of deterioration in the case of long-term driving in a wide range of applications such as PDP and fluorescent lamp. It is difficult. For example, in the case where the technique proposed in Patent Document 1 is used, since it has been studied only for a fluorescent lamp, application to a PDP or the like is substantially difficult. That is, in the PDP, discharge is generated in a minute space during driving, and high-energy ultraviolet rays having a short wavelength affect the phosphor. Even if the technique proposed in Patent Document 1 is adopted, the PDP is actually used. It is difficult to protect the phosphor. Also, if this technology is adopted for PDP, visible light generated by ultraviolet light or light emission, which is excitation light, is absorbed by the compound layer that coats the phosphor, thus significantly reducing the light emission efficiency of PDP. Another problem will occur.

  In addition, in the techniques proposed in Patent Documents 2 and 3, it is considered that a little time-dependent deterioration suppression effect can be obtained by adding tungsten oxide at the time of manufacture. It is considered insufficient to satisfy both. That is, when tungsten oxide is added in the amounts proposed in Patent Documents 2 and 3, the luminous efficiency is lowered. Conversely, when the addition amount of tungsten oxide is reduced, tungsten oxide is reduced. While maintaining the same luminous efficiency as the phosphor not added, there is a trade-off relationship that the effect of suppressing deterioration over time cannot be sufficiently obtained.

  The present invention has been made to solve the above-mentioned problems, and it is difficult to cause deterioration over time due to driving for various uses, and a phosphor capable of maintaining high luminous efficiency regardless of the length of driving time and An object of the present invention is to provide a PDP using the phosphor.

The inventors of the present application examined the above-mentioned problem in detail, and in order to achieve both the maintenance of the light emission efficiency and the suppression of deterioration with time in the ZSM phosphor, the composition of the phosphor particle surface and its vicinity is precisely determined. It was found that controlling and improving crystallinity are extremely important.
Based on the above investigation results, the present invention adopts the following configuration.
The phosphor according to the present invention has a phosphor main portion made of zinc silicate as a base material and manganese as an activator, and titanium (Ti), zirconium (Zr) and hafnium are formed on the phosphor main portion. It is characterized in that at least one element of (Hf) is added.

The phosphor according to the present invention is characterized in that at least one element of molybdenum (Mo) and tungsten (W) is added to the phosphor main part.
Furthermore, the PDP according to the present invention is characterized by comprising the above phosphor.

  In the phosphor according to the present invention, by adding at least one element selected from the group consisting of Ti, Zr, and Hf, segregation of silicon (Si) on the particle surface and in the vicinity thereof is reduced, and a high crystal Have sex. In the present invention, the crystallinity at the particle surface and in the vicinity thereof can also be improved by adding at least one of Mo and W to the phosphor main part.

  Since the phosphor according to the present invention does not adopt a configuration in which the particle surface is covered with a film, ultraviolet light and visible light are not absorbed, and high luminous efficiency can be maintained. In addition, since the phosphor according to the present invention does not form a film as in the technique proposed in Patent Document 1 above, the phosphor occupies a small size without reducing the proportion of the total phosphor. It is also effective for applications such as PDP that require formation of a layer.

Furthermore, in the present invention, since the selected element is added to the main part of the phosphor, the PDP has a short wavelength and has sufficient deterioration resistance even for a PDP affected by high energy ultraviolet rays.
Therefore, in the phosphor according to the present invention, deterioration with time due to driving is difficult to occur even for various usages, and high light emission efficiency can be maintained regardless of the driving time.
The phosphor according to the present invention preferably employs the following configuration.

  In the present invention, when adding at least one selected from Ti, Zr, and Hf, the total addition ratio is 0.0001 mol to 0.01 mol with respect to 1 mol of the phosphor main part. Is desirable from the viewpoint of crystallinity at and near the particle surface. Furthermore, it is desirable to define the addition ratio with respect to 1 mol of the phosphor main part to 0.0005 mol or more and 0.005 mol or less.

  In addition, when adding at least one element of Mo and W, it is desirable to define a total addition ratio of 0.00005 mol to 0.01 mol with respect to 1 mol of the phosphor main part, and 1 mol of the phosphor main part. On the other hand, it is more desirable to set the ratio to a total of 0.0001 mol or more and 0.005 mol or less, or to a ratio of a total of 0.00005 mol to 0.0005 mol with respect to 1 mol of the phosphor main part.

Further, in the phosphor according to the present invention, it is desirable that the atomic ratio of zinc to silicon is set to 1.5 or more in the particle surface and the vicinity thereof from the viewpoint of obtaining high luminous efficiency. Here, the above-mentioned particle surface and its vicinity region are reasonable when capturing the composition of the phosphor to be a region from the particle surface to a depth of 4 nm.
As the atomic ratio of zinc to silicon in the present invention, a value obtained by measurement using X-ray photoelectron spectroscopy using AlKα rays as irradiation X-rays can be employed. More specifically, it is converted from the number of relative silicon atoms in the particle surface and its neighboring region converted from the photoelectron peak area caused by 2p orbitals in silicon atoms, and from the photoelectron peak area caused by 2p3 orbitals in zinc atoms. It can be defined by the ratio to the number of relative zinc atoms in the surface of the particle and the vicinity thereof.

  As for the atomic ratio of zinc to silicon in the present invention, the particle surface converted from the photoelectron peak area due to the 2p orbital in the silicon atom and the vicinity thereof using the same X-ray photoelectron spectroscopy as described above. When the ratio is defined by the ratio between the relative number of silicon atoms and the number of relative zinc atoms in the particle surface converted from the photoelectron peak area due to the 3p orbital in the zinc atom and the vicinity thereof, it is 1.7 or more. It is desirable to take a value.

Since the PDP according to the present invention has the phosphor according to the present invention having the above advantages, it has both advantages of high emission luminance and excellent deterioration resistance. In particular, in the PDP according to the present invention, it is desirable to use the phosphor as a constituent material of the green phosphor layer or a partial region thereof.
It should be noted that the phosphor according to the present invention has the above advantages even when used for applications other than PDP, such as a fluorescent lamp.

Hereinafter, the best mode for carrying out the present invention will be described with an example. The embodiment described below is merely an example, and the present invention is not limited to this.
(Embodiment 1)
1. Configuration of PDP 1 The configuration of the PDP 1 according to the embodiment of the present invention will be described with reference to FIG. FIG. 1 is a perspective view (partial cross-sectional view) showing a main part extracted from a partial structure of a PDP 1 according to an embodiment.

1-1. Configuration of Front Panel 10 As shown in FIG. 1, the front panel 10 has scan electrodes (hereinafter referred to as “Scn electrodes”) on a surface (a lower surface in FIG. 1) of the front substrate 11 facing the rear panel 20. A plurality of display electrode pairs 12 including 12a and sustain electrodes (hereinafter referred to as "Sus electrodes") 12b are arranged in parallel to each other and cover the display electrode pairs 12. The layer 13 and the protective layer 14 are coated in order.

The front substrate 11 is made of, for example, high strain point glass or soda lime glass. In addition, each of the Scn electrode 12a and the Sus electrode 12b has wide transparent electrodes 12a1 and 12b1 made of ITO (tin-doped indium oxide), SnO ₂ (tin oxide), ZnO (zinc oxide), and the like, and reduces electric resistance. The bus electrodes 12a2 and 12b2 formed of Cr (chromium) -Cu (copper) -Cr (chromium), Ag (silver), or the like are laminated. The size of each part constituting the electrodes 12a and 12b is, for example, that the transparent electrodes 12a1 and 12b1 have a thickness of 0.1 μm and a width of 150 μm, and the bus electrodes 12a2 and 12b2 have a thickness of 7 μm and a width of 95 μm. The distance between the Scn electrode 12a and the Sus electrode 12b is, for example, about 80 μm.

The dielectric layer 13 is made of a low melting point glass material such as Pb-B, and the protective layer 14 is mainly composed of MgO (magnesium oxide) or MgF ₂ (magnesium fluoride). . The dielectric layer 13 is formed with a thickness of about 30 μm, for example, and the protective layer 14 is formed with a thickness of about 1 μm, for example.
1-2. Configuration of Back Panel 20 As shown in FIG. 1, the back panel 20 has a direction (X direction) that is substantially orthogonal to the display electrode pair 12 on the surface of the back substrate 21 that faces the front panel 10 (upper surface in FIG. 1). ), A plurality of data electrodes (hereinafter referred to as “Dat electrodes”) 22 are arranged in stripes, and a dielectric layer 23 is formed so as to cover the Dat electrodes 22. On the dielectric layer 23, a main partition wall 24a is provided between adjacent Dat electrodes 22, and an auxiliary partition wall 24b is formed in a direction substantially orthogonal to the main partition wall 24a. And the partition 24 in the back panel 20 is comprised by the auxiliary partition 24b. Although not shown in detail in the drawing, the upper end of the auxiliary partition wall 24b is set slightly lower than the upper end of the main partition wall 24a in the Z direction. Here, the back substrate 21 is also made of high strain point glass or soda lime glass.

In addition to Ag, the Dat electrode 22 is made of a metal material such as gold (Au), chromium (Cr), copper (Cu), nickel (Ni), platinum (Pt), or a method of laminating them. Combinations can also be used. The size of the Dat electrode 22 is set to, for example, a thickness of 5 μm and a width of 60 μm. The interval between adjacent Dat electrodes 22 is set to about 150 μm, for example. The dielectric layer 23 is made of a low-melting glass material such as Pb—B, but may contain aluminum oxide (Al ₂ O ₃ ) or titanium oxide (TiO ₂ ). The partition wall 124 is formed using, for example, a lead glass material. The thickness of the dielectric layer 23 is, for example, about 30 μm.

For example, when the PDP 1 according to the present embodiment assumes a 42-inch class VGA specification, the pitch in the X direction (the pitch between adjacent auxiliary partition walls 24b) is about 1080 μm, and the design dimension of the partition 24 is the pitch in the Y direction. The (pitch between adjacent main partition walls 24a) is about 360 μm, the height is set to about 150 μm, and the width is set to about 40 μm.
A phosphor layer 25 is provided on each inner wall surface of the recessed portion formed by the dielectric layer 23 and the partition wall 24. The phosphor layer 25 is divided into a red (R) phosphor layer 25R, a green (G) phosphor layer 25G, and a blue (B) phosphor layer 25B for each wavelength of light emitted by incidence of ultraviolet rays as excitation light. And is color-coded for each depression. For example, as shown in the enlarged portion of FIG. 1, the G phosphor layer 25G is composed of a plurality of G phosphors 250G.

The phosphors constituting each of the R, G, and B color phosphor layers 25R, 25G, and 25B have the following composition, for example.
R phosphor; (Y, Gd) BO ₃ : Eu
G phosphor; Zn _1.9 SiO ₄ Mn _0.1 α _x
B phosphor; BaMgAl ₁₀ O ₁₇ : Eu
In the composition of the G phosphor 250G, “α” includes a selected specific element and is a characteristic part in the present embodiment. This will be described later.

1-3. Arrangement of Front Panel 10 and Back Panel 20 As shown in FIG. 1, the PDP 1 includes a front panel 10 and a back panel 20 sandwiching a partition wall 24 formed on the back panel 20 as a gap material, and a display. The electrode pair 12 and the Dat electrode 22 are arranged in a direction substantially orthogonal to each other, and the outer peripheral portions of the panels 10 and 20 are sealed in this state. With this configuration, a discharge space 30 partitioned by each partition wall 24 is formed between the front panel 10 and the back panel 20, and both panels 10 and 20 form a sealed container. A discharge space 30 in the PDP 1 is filled with a discharge gas formed by mixing Ne, Xe, He, or the like. The sealed pressure of the discharge gas is, for example, about 6.7 × 10 ^{4 to} 1.0 × 10 ⁵ Pa.

Note that the Xe partial pressure in the discharge gas is normally set to less than 7%, but may be set to 7% or more, and further 10% or more for the purpose of improving the light emission luminance of the panel.
In the PDP 1, discharge cells (not shown) are formed at each location where the display electrode pair 12 and the Dat electrode 22 are three-dimensionally crossed. The PDP 1 is in a state where a plurality of discharge cells are arranged in a matrix, and one pixel is constituted by three discharge cells of R, G, and B. As an example, the pixel size in the PDP 1 is 1080 μm × 1080 μm.

2. Next, a method for driving the PDP 1 will be described. Note that the driving method of the PDP 1 according to the present embodiment is the same as the driving method of the conventional PDP, and is not shown.
A PDP device, which is a display device, is formed by connecting a drive unit including each driver to each electrode 12a, 12b, 22 of the PDP 1 according to the present embodiment (not shown).

  In driving a PDP apparatus including the PDP 1 as a display panel, for example, one field is divided into eight subfields SF1 to SF8, and the luminance relative ratio of each subfield is 1: 2: 4: 8: 16: 32: 128. The number of sustain pulses is set so that By controlling lighting / non-lighting of each of the subfields SF1 to SF8 according to display luminance data, 256 gradations can be displayed with a combination of the eight subfields SF1 to SF8. In the present embodiment, display driving is performed with 256 gradations as an example, but the present invention is not limited to this.

  Each of the subfields SF1 to SF8 includes an initialization period and a writing period to which a fixed time common to each other is assigned, and a sustain period set with a length of time corresponding to the relative ratio of luminance. For example, when performing display driving of the PDP 1, first, an initializing discharge is generated in all the discharge cells in the initializing period, whereby the influence of the discharge performed in the subfield before the subfield is affected. Absorbs variations in discharge and discharge characteristics (initialization of discharge cells).

  Next, in the writing period, the plurality of Scn electrodes 12a are sequentially scanned for each line based on the subfield data, and a slight discharge (writing discharge) is generated between the Scn electrode 12a and the Dat electrode 22. Thus, in the discharge cell in which the write discharge, which is a minute discharge, is generated between the Scn electrode 12a and the Dat electrode 122, required wall charges are accumulated on the surface of the protective layer 14 of the front panel 10.

  Thereafter, in the sustain period, a rectangular wave sustain pulse is applied to the Scn electrode 12a and the Sus electrode 12b at a predetermined voltage and a predetermined cycle. The sustain pulse applied to the Scn electrode 12a and the sustain pulse applied to the Sus electrode 12b have the same period and are out of phase by a half period. Applied to.

By applying these sustain pulses, a potential difference is generated between the Scn electrode 12a and the Sus electrode 12b in the sustain period, and this potential difference and the wall charges accumulated in the discharge cells in which writing is performed in the writing period. The total potential difference exceeds the discharge start voltage, and a sustain discharge occurs in the discharge cell in which writing has been performed.
Vacuum ultraviolet rays (wavelength: 147 nm) generated by the sustain discharge cause each of the phosphor layers 25R, 25G, and 25B to emit light so that visible light is emitted from the front panel 10 side. By repeating such an operation between the subfields SF1 to SF8, the discharge cells regularly arranged corresponding to the display data are selectively discharged and light is displayed on the display area of the PDP 1.

During the sustain period, the thin line rectangular pulse may be applied to the Dat electrode 22 to improve the luminance.
3. G phosphor 250G
Next, a characteristic G phosphor 250G in the present embodiment will be described.
In the PDP 1 according to the present embodiment, a material having the following composition is used as the G phosphor 250G constituting the G phosphor layer 25G.

G phosphor 250G; Zn _1.9 SiO ₄ : 0.1Mn: 0.001Ti
That is, the G phosphor 250G according to the present embodiment has titanium (Ti) as the additive element α. And, as shown in the above composition formula, the addition ratio of Ti is within the range of 0.0001 mol or more and 0.01 mol or less with respect to 1 mol of (Zn _1.9 SiO ₄ Mn _0.1 ) which is the phosphor main part. It has become. The Ti addition ratio is more preferably in the range of 0.0005 mol or more and 0.005 mol or less with respect to 1 mol of (Zn _1.9 SiO ₄ Mn _0.1 ).

  In addition, in G phosphor 250G according to the present embodiment, the atomic ratio (surface Zn / Si ratio) of zinc (Zn) to silicon (Si) on the particle surface and in the vicinity thereof is set to 1.5 or more. Yes. Here, the surface Zn / Si ratio in the vicinity of the phosphor particle surface is a value measured by X-ray photoelectron spectroscopy (XPS) using AlKα rays. More specifically, using the above method, the number of relative silicon atoms at and near the phosphor particle surface converted from the photoelectron peak area due to the 2p orbital in the silicon atom, and the 2p3 orbital in the zinc atom It can be expressed as a ratio (surface Zn / Si ratio) to the phosphor particle surface converted from the photoelectron peak area and the number of relative zinc atoms in the vicinity thereof (conversion method 1).

In addition, the particle | grain surface and its vicinity area | region in the said G fluorescent substance 250G are about 4 nm from the surface in the radial direction of a particle | grain.
Further, the evaluation of the surface Zn / Si ratio is a measurement method using X-ray photoelectron spectroscopy (XPS) using AlKα rays as irradiation X-rays in the same manner as described above, and silicon is in a 2p orbit in a silicon atom. The number of relative silicon atoms at the phosphor particle surface and in the vicinity thereof is converted from the photoelectron peak area caused by the photoelectron peak area. In particular, with respect to zinc, relative to the surface of the phosphor particle and the vicinity thereof from the photoelectron peak area caused by the 3p orbital in the zinc atom. By converting the number of zinc atoms, it is also possible to evaluate the ratio (surface Zn / Si ratio) between these two (conversion method 2). When the (surface Zn / Si ratio) is evaluated by the evaluation conversion method based on this method, it is desirable to set the (surface Zn / Si ratio) value of the G phosphor 250G to 1.7 or more.

4). Advantages of G phosphor 250G and PDP1 As described above, in the G phosphor 250G according to the present embodiment, Ti is in the above ratio with respect to the phosphor main part (Zn _1.9 SiO ₄ Mn _0.1 ). Therefore, there is little segregation of silicon (Si) on the particle surface and in the vicinity thereof (for example, a region from the particle surface to a depth of about 4 nm), and the crystallinity is high.

  Further, the G phosphor 250G does not form a film like the phosphor proposed in the above-mentioned Patent Document 1, so that there is no attenuation due to absorption of ultraviolet rays or visible light, and high luminous efficiency can be maintained. Since the film is not formed, the ratio of the total phosphor is maintained largely. For this reason, the G phosphor 250G can maintain a high luminous efficiency even when the phosphor layer 25 is formed in a small size like the PDP 1 according to the present embodiment.

Furthermore, in the G phosphor 250G according to the present embodiment, since Ti is added to the phosphor main part (Zn _1.9 SiO ₄ Mn _0.1 ), it has a short wavelength and has high energy ultraviolet rays. The affected PDP 1 also has sufficient deterioration resistance characteristics.
Therefore, in the G phosphor 250G according to the present embodiment, deterioration with time due to driving is difficult to occur, and high light emission efficiency can be maintained regardless of the length of driving time.

Note that, by defining the Ti addition ratio in the G phosphor 250G within the above range, it is possible to achieve both high luminous efficiency and deterioration resistance. Further, in the G phosphor 250G, the (surface Zn / Si ratio) is set to 1.5 or more in (Conversion method 1) and 1.7 or more in (Conversion method 2), so that the effect of suppressing deterioration with time is obtained. It is even higher.
Further, in the PDP 1 according to the present embodiment, the G phosphor 250G having the above advantages is adopted as the constituent material of the G phosphor layer 25G, so that the time-dependent deterioration of the G phosphor layer 25G due to driving hardly occurs. In addition, high luminous efficiency is maintained regardless of the driving time, and the image quality is high.

5). Variation of Additive Element α in G Phosphor 250G In this embodiment, Ti is employed as an example of an additive element for the phosphor main part (Zn _1.9 SiO ₄ Mn _0.1 ), but zirconium (Zr) or hafnium (Hf), or a combination of these. Even when such an element is employed, the addition ratio is more preferably within the range of 0.0001 mol or more and 0.01 mol or less with respect to 1 mol of the phosphor main part (Zn _1.9 SiO ₄ Mn _0.1 ). Is within the range of 0.0005 mol or more and 0.005 mol or less. For example, it can be set as the following composition.

Zn _1.9 SiO ₄ Mn _0.1 : 0.0005Ti: 0.0005Zr
Zn _1.9 SiO ₄ Mn _0.1 : 0.0005Zr: 0.0005Hf
Zn _1.9 SiO ₄ Mn _0.1 : 0.0005Hf: 0.0005Ti
Zn _1.9 SiO ₄ Mn _0.1 : 0.0005Ti: 0.0002Zr: 0.003Hf
Various other variations can be adopted. This will be described later.

6). Manufacturing Method of G Phosphor 250G Hereinafter, a manufacturing method of G phosphor 250G according to the present embodiment will be described with reference to FIGS.
As shown in FIG. 2, the raw material, using a manganese compound 250G ₁ and zinc compound 250G ₂ and silicon dioxide 250G ₃ and the titanium oxide 250G _4. Among these, the manganese compound 250G ₁ is used as a material serving as a manganese source, and for example, high-purity (purity 99% or more) manganese hydroxide, manganese carbonate, manganese nitrate, manganese halide, manganese oxalate. It becomes a material which becomes manganese oxide by firing. In this embodiment, MnCO ₃ is used as an example.

The zinc compound 250G ₂ is a material that is a source of zinc, for example, zinc oxide and zinc oxide by firing high-purity (purity 99% or more) zinc hydroxide, zinc carbonate, zinc nitrate, zinc halide, zinc oxalate, and the like. Material. In this embodiment, ZnO is used as an example.
The silicon dioxide 250G ₃ is a material serving as a silicon source, and is a high-purity (purity 99% or more) compound. In the present embodiment, SiO ₂ is used as an example.

The titanium oxide 250G4 is a material that serves as a titanium source. For example, titanium dioxide having a high purity (purity 99% or more) can be used.
In addition, it is also possible to directly use high-purity (99% or more) manganese oxide as a material that becomes a manganese source, instead of the manganese compound 250G ₁ , and as a material that becomes a zinc source, the zinc compound 250G Instead of ₂ , it is also possible to use zinc oxide of high purity (purity 99% or more) directly. Furthermore, it is also possible to use a hydroxide of silicon obtained by hydrolyzing a silicon alkoxide compound such as ethyl silicate instead of the silicon oxide 250G ₃ as described above.

As shown in FIG. 2, the four types of raw materials 250G ₁ , 250G ₂ , 250G ₃ , 250G ₄ are mixed (step S1). The mixing ratio of each raw material for forming the G phosphor 250G is, for example, as follows.
MnCO ₃ (for example, manufactured by Kojundo Chemical Laboratory Co., Ltd.): 0.10 mol (1.076 g)
ZnO (for example, manufactured by Kojundo Chemical Laboratory Co., Ltd.): 1.90 mol (13.636 g)
SiO ₂ (for example, manufactured by Kojundo Chemical Laboratory Co., Ltd.): 1.00 mol (5.298 g)
TiO ₂ (for example, manufactured by Kojundo Chemical Laboratory Co., Ltd.): 0.001 mol (0.004 g)
For the mixing in step S1, a commonly used V-type mixer, stirrer, etc., a ball mill, a vibration mill, a jet mill or the like having a pulverizing function can be used.

In step S1, four kinds of raw materials 250G ₁ , 250G ₂ , 250G ₃ , 250G ₄ are mixed and then dried (step S2), whereby mixed and pulverized powder 250G ₁₀ is obtained. Here, in step S1, for example, each raw material is put into a polyethylene container (capacity is about 300 cc) having an inner diameter of 70 mm and a depth of 80 mm, together with 150 g of stabilized zirconia cobblestone having a diameter of 3 mm and pure water of 80 cc. Load and mix for 24 hours at 150 rpm. In step S2, the mixture obtained in step S1 is dried for the fourth time using a hot air dryer.

Next, as shown in FIG. 2, in step S3, for example, about 5 g of the mixed pulverized powder 250G ₁₀ is loaded on an alumina board (about 10 mm × about 100 mm), and in this state, the inner diameter is about 100 mm and the length is long. Firing is performed using a 1500 mm tubular firing furnace. The step S3 for performing the firing includes a sub-step S31 for performing heating, a sub-step S32 for maintaining at the maximum temperature, and a sub-step S33 for performing temperature lowering. The conditions such as the temperature in step S3 for firing will be described with reference to FIG.

As shown in FIG. 3, in sub-step S31, 1200 ° C. (points) with a temperature increase rate of 200 deg per hour from room temperature (point p0) while introducing 1 L of compressed air into the tubular firing furnace per minute. Heat to p1). In sub-step S32, the temperature of 1200 ° C. is maintained for 4 hours (the maximum temperature is maintained from point p1 to point p2).
Next, in sub-step S33, the introduction of compressed air to the tubular firing furnace is shut off, and the temperature is lowered over about 12 hours (from point p2 to point p3).

As shown in FIG. 2, by completing the firing step S3, a G phosphor 250G that is a manganese-activated zinc silicate phosphor having the above-described configuration is obtained.
In addition, the conditions regarding the temperature and time in baking as shown in FIG. 3 are examples, and are not particularly limited. In addition, regarding the type and amount of gas introduced into the furnace, the raw material to be used and its particle shape, further its specific surface area, the shape of the phosphor 250G to be finally obtained, the size of the fired powder to be used, Adjustment is necessary depending on the shape and the like.

7). Confirmation of Superiority Hereinafter, confirmation results of the above-described superiority of the G phosphor 250G according to the present embodiment and the PDP 1 including the same will be described with reference to Tables 1 to 3 and FIGS. Tables 1 to 3 show the compositions of the samples used in this confirmation.

表１〜３に示すように、本確認においては、添加元素の種類およびその添加量を変化させて各サンプル（実施例１〜７５）を形成した。また、比較例１として、Ｔｉ、Ｚｒ、Ｈｆ、ＭｏおよびＷの何れも添加していない従来のＧ蛍光体を用意した。なお、各表１〜３の中で、「元素の添加量」および「表面Ｚｎ／Ｓｉ比分析値」は、次の方法により求められたものである。

As shown in Tables 1 to 3, in this confirmation, each sample (Examples 1 to 75) was formed by changing the type of additive element and its addition amount. Further, as Comparative Example 1, a conventional G phosphor not containing any of Ti, Zr, Hf, Mo and W was prepared. In Tables 1 to 3, “element addition amount” and “surface Zn / Si ratio analysis value” are determined by the following methods.

  As a method for measuring the addition amount of the additive element, inductively coupled plasma atomic emission spectrometry (ICP-AES) can be used. When a sample is dissolved in an acid or alkali and then sprayed into the plasma, the elements present in the solution are atomized and excited and are inherent to each element when transitioning to a lower energy level. Emit light. In this inductively coupled plasma atomic emission spectrometry (ICP-AES), the composition ratio in a sample can be determined by measuring the wavelength and intensity of light unique to each element.

In addition, as a method for measuring the composition ratio of the entire phosphor particles, there are a titration method, an inductively coupled plasma mass spectrometry method, a fluorescent X-ray analysis method, and the like, and any method may be used.
Furthermore, in the above embodiment, the atomic ratio of zinc to silicon (surface Zn / Si ratio) in the vicinity of the phosphor particle surface is extremely important. The surface Zn / Si ratio can be measured by X-ray photoelectron spectroscopy (XPS) as described above. In this confirmation, the relative sensitivity factors of the 2p orbitals in Si atoms, the 2p3 orbitals in Zn atoms, and the 3p orbitals in Zn atoms are 0.368, 2.768, and 1.029, respectively. The relative atomic number ratio was calculated by dividing each photoelectron peak area.

7-1. Sample (Examples 1-8)
As shown in Table 1, in Examples 1 to 8, the addition amount was changed in the range of 0.00005 to 0.02 mol with respect to 1 mol of the phosphor main part (Zn _1.9 SiO ₄ Mn _0.1 ). While adding Ti. In Examples 1 to 8, the surface Zn / Si ratio was adjusted to “1.0” by (Conversion method 1) and “1.2” by (Conversion method 2).

(Examples 9 to 16)
In Examples 9 to 16, Zr was added to the phosphor main part (Zn _1.9 SiO ₄ Mn _0.1 ). The additive amount of Zr in Example 9-16, like the Ti of the above Examples 1-8, the phosphor main portion _{(Zn 1.9 SiO 4 Mn 0.1)} 1mol, 0.00005~ The amount was 0.02 mol. The surface Zn / Si ratio was the same as in Examples 1-8.

When Zr is to be added to the phosphor main part, ZrO ₂ that is a Zr source may be used instead of TiO _{2 in} the method for manufacturing the G phosphor 250G according to the above embodiment. . There is no change in other factors related to the manufacturing method.
(Examples 17 to 24)
In Examples 17 to 24, Hf was added to the phosphor main part (Zn _1.9 SiO ₄ Mn _0.1 ). About the amount of Hf addition in Examples 17 to 24, the phosphor main part (Zn _1.9 SiO ₄ Mn _0.1 ) is the same as Ti in Examples 1 to 8 and Zr in Examples 9 to 16 above. It was set to 0.00005-0.02 mol with respect to 1 mol. The surface Zn / Si ratio was the same as in Examples 1 to 8 and Examples 9 to 16.

When Hf is to be added to the phosphor main part, HfO ₂ as a Hf source may be used instead of TiO _{2 in} the method for manufacturing the G phosphor 250G according to the above embodiment. .
(Examples 25 to 40)
In Examples 25 to 40, at least two types of elements composed of Ti, Zr, and Hf were selectively added to the phosphor main part (Zn _1.9 SiO ₄ Mn _0.1 ). . As shown in Table 1, the total amount of elements added was 0.0001 mol (per 1 mol of phosphor main part) in Examples 25 to 28, and 0.0005 mol (per mol of phosphor main part) in Examples 29 to 32. ), 0.001 mol (per 1 mol of phosphor main part) in Examples 33 to 36, and 0.005 mol (per mol of phosphor main part) in Examples 37 to 40.

Also in Examples 25 to 40, the surface Zn / Si ratio is set to “1.0” in (Conversion method 1) and “1.2” in (Conversion method 2).
(Examples 41 to 67)
As shown in Table 2, in Examples 41 to 67, the phosphor main part (Zn _1.9 SiO ₄ Mn _0.1 ) was selected from an element group composed of Ti, Zr, and Hf. Any one kind of element was added. The addition amount of the element in each Example is as showing in Table 2, and the group of Examples 41-46, the group of Examples 47-58, the group of Examples 59-64, and Examples 65-67. The surface Zn / Si ratio was changed for each group. Specifically, in Examples 41 to 46, “Conversion Method 1” is “1.2”, and (Conversion Method 2) is “1.4”. In Examples 47 to 58, (Conversion Method 1) “1.5”, “Conversion method 2” is “1.7”, and in Examples 59 to 64, “Conversion method 1” is “1.7”, and (Conversion method 2) is “2.0”. In Examples 65 to 67, the conversion method 1 was “1.9” and the conversion method 2 was “2.2”.

  In Examples 41 to 67, in the heating sub-step S31 in the firing step S3 of FIG. 2, an appropriate amount of ZnO is simultaneously mounted in the tubular firing furnace, and the amount of compressed air to be supplied is 0 to 1 L / min. The surface Zn / Si ratio was adjusted by appropriately adjusting within the range. More specifically, in order to increase the surface Zn / Si, ZnO powder (the same raw material as the sample) was placed on another alumina boat, and heat treatment was performed simultaneously with the alumina boat on which the mixed powder was placed. At that time, in particular, in the heating sub-step S31 and the maximum temperature maintenance sub-step S32 in the firing temperature schedule, the amount of compressed air to be supplied was reduced to perform the processing. By appropriately adjusting the amount of compressed air supplied in this way, it becomes possible to manufacture a phosphor having a desired surface Zn / Si ratio as shown in Table 2. However, the method for adjusting the surface Zn / Si ratio is not limited to this, and various other methods can be adopted.

(Examples 68 to 75)
As shown in Table 3, in Examples 68 to 75, Ti, Zr, and Hf were used for the phosphor main part (Zn _1.9 SiO ₄ Mn _0.1 ) as in Examples 25 to 40. At least two types were selectively added from the constituent element group. The total amount of elements added was 0.001 mol (per 1 mol of phosphor main part) in Examples 68 to 71, and 0.005 mol (per 1 mol of phosphor main part) in Examples 72 to 75.

In Examples 68 to 75, the surface Zn / Si ratio was set to “1.5” in (Conversion method 1) and “1.7” in (Conversion method 2).
(Comparative Example 1)
As shown in Tables 1 to 3, in Comparative Example 1, none of Ti, Zr, and Hf was added, and the surface Zn / Si ratio was “1.0” in (Conversion method 1) and in (Conversion method 2). It is adjusted to “1.2”.

7-2. Method for evaluating phosphor performance The following performance evaluation was performed on each sample of Examples 1 to 75 and Comparative Example 1.
The phosphor performance evaluation method in this confirmation was performed by irradiating each of the phosphors of Examples 1 to 75 and Comparative Example 1 with vacuum ultraviolet light (VUV) having a wavelength of 146 nm and exciting them, and calculating the emission luminance value at this time. It was measured. About the result, it describes corresponding to each sample of Tables 1-3. More specifically, the relative light emission luminance values when the luminance value of the phosphor according to Comparative Example 1 is set to 100 are shown in Tables 1 to 3.

  The relative light emission luminance value is the relative light emission luminance value after 100 hours of continuous irradiation with the relative light emission luminance value of the phosphor after firing (referred to as “initial” in Tables 1 to 3) and vacuum ultraviolet light (VUV). The value (in Tables 1 to 3, described as “after 100 hr.”) Was measured and evaluated. Further, in Tables 1 to 3, the ratio of the relative light emission luminance value after “100 hr.” To the relative light emission luminance value in “Initial” as a percentage (in Tables 1 to 3, “Light emission luminance maintenance ratio”). And calculated for each sample.

In the phosphor performance evaluation method, the emission luminance maintenance ratio of Comparative Example 1 was 74%. And about the light emission luminance maintenance factor in fluorescent substance, it may be 74% or more of the said comparative example 1, and if it is 80% or more, it is more preferable. Further, the relative light emission luminance value in the “initial stage” may be 85% or more with respect to Comparative Example 1, and more preferably 90% or more.
7-3. Consideration As shown in Table 1, all the samples of Examples 1 to 8 have a higher emission luminance maintenance ratio than Comparative Example 1. Specifically, the emission luminance maintenance rate of Comparative Example 1 was 74.0%, whereas in Examples 1-8, it was 76.0-91.2%, 2.0 points. It is 17.2 points higher. In particular, in Examples 3 to 9, the light emission luminance maintenance rate is 80% or more.

Further, the “initial” relative light emission luminance is a value larger than 85% with respect to Comparative Example 1 in all of Examples 1 to 8, and particularly 90% or more in Examples 1 to 7. It has become. Further, in Examples 1 to 6, the relative light emission luminance value is 95% or more.
For these reasons, Examples 1 to 8 have a high effect of suppressing deterioration over time and are sufficiently acceptable from the viewpoint of relative light emission luminance at the “initial stage”. Therefore, the addition amount of Ti is preferably 0.0001 to 0.01 mol, and more preferably 0.0005 to 0.005 mol.

  Next, as shown in Table 1, all the samples of Examples 9 to 16 have a higher emission luminance maintenance ratio than that of Comparative Example 1. In addition, the relative light emission luminance value in the “initial stage” was 89% to 100% of the comparative example 1 in all the samples of Examples 9-16. From these results, Examples 9 to 16 have a higher temporal deterioration suppressing effect than Comparative Example 1, and the “initial” relative light emission luminance value is sufficiently allowed. In particular, in Examples 10 to 15, the “initial” relative light emission luminance value is 90% or more compared to Comparative Example 1, and the amount of Zr added is preferably 0.0001 to 0.01 mol.

In Examples 11 to 13, since the emission luminance maintenance ratio is 80% or more and the “initial” relative emission luminance value is also 95% or more, the amount of Zr added is 0.0005 to 0. A range of 0.002 mol is particularly preferred.
Also about Examples 17-24, it has a result which has a high luminous-intensity maintenance factor compared with the comparative example 1 which does not add Hf. From this, in Examples 17-24, it is judged that it has a high temporal deterioration suppression effect. In particular, in Examples 17 to 21, since the “initial” relative light emission luminance is 90% or more as compared with Comparative Example 1, it has sufficient performance from this viewpoint. When comparing Examples 17 to 24 and Comparative Example 1, it is considered that the amount of Hf added is preferably in the range of 0.00005 to 0.002 mol.

Furthermore, in Examples 19 and 20, the emission luminance maintenance rate is 80% or more, and the “initial” relative emission luminance value is also 95% or more. It turns out that it is 0.0005-0.001 mol.
Next, as shown in the lower half of Table 1, in each case, Examples 25 to 40 are comparative examples in which the above elements are not added regardless of the amount of addition (0.0001 to 0.005 mol in total). Compared to 1, it has a higher emission luminance maintenance rate. From this, it is judged that all of Examples 25 to 40 have a high temporal deterioration suppressing effect.

Thus, in the phosphor according to the present invention, only one of Ti, Zr, and Hf may be added as in Examples 1 to 24 above. 40, it can be seen that even when at least two kinds of elements are added in combination, the effect of suppressing deterioration with time is high. Further, when a plurality of elements are combined and added to the phosphor main part (Zn _1.9 SiO ₄ Mn _0.1 ), the “initial” relative light emission luminance value is 90% or more, and 100 hr. The subsequent luminance maintenance rate is 80% or more. Therefore, in the phosphor according to the present invention, it is more preferable that the amount of elements selectively added from the group of elements is in the range of 0.0005 to 0.005 mol in total.

  Next, as shown in Table 2, in Examples 41 to 67, the surface Zn / Si ratio was in the range of 1.2 to 1.9 (conversion method 1), and 1.4 to 2 in (conversion method 2). .2 in any case, the maintenance rate of the relative light emission luminance was improved in any case as compared with Comparative Example 1 containing no additive. As a result, the phosphor having a surface Zn / Si ratio in the range of 1.2 to 1.9 according to the evaluation method (conversion method 1) is judged to have an effect of suppressing deterioration with time as in the above-described example. can do.

Surface Zn / Si ratio in the case of adding Ti at a ratio of 0.01 mol to 1 mol of the phosphor main part (Zn _1.9 SiO ₄ Mn _0.1 ), “initial” relative emission luminance and emission luminance maintenance ratio The relationship will be described with reference to FIG. In FIG. 4, the values of the relative light emission luminances and the light emission luminance maintenance ratios of Example 4 in Table 1 and Examples 41, 48, 59, and 65 in Table 2 are plotted.

As shown in FIG. 4, when the surface Zn / Si ratio is 1.5 (conversion method 1) or more (in the case of conversion method 2, 1.7 or more), that is, Example 48, Example 59, and Example. In Example 65, the emission luminance maintenance ratio (after 100 hr.) Is higher than those in Example 4 and Example 41, and it can be seen that the effect of suppressing deterioration of the phosphor over time is particularly high.
FIG. 4 shows the case where the addition ratio of Ti to 1 mol of the phosphor main part (Zn _1.9 SiO ₄ Mn _0.1 ) is 0.005 mol, that is, Example 6, Example 42, Example 49, and Although the above values in Example 60 are also plotted, Example 49 and Example 60 in which the surface Zn / Si ratio is 1.5 (conversion method 1) or more are the same as in the case where the addition ratio is 0.001 mol. Both values are high.

In addition, although illustration is abbreviate | omitted, also when adding Zr, Hf, etc., when surface Zn / Si ratio is 1.5 or more by (conversion method 1), and 1.7 or more by (conversion method 2) In addition, both the “initial” relative light emission luminance and the light emission luminance maintenance ratio have high values. This can be seen by referring to Tables 1 and 2.
Therefore, from FIG. 4, in the case where Ti, Zr, and Hf are added to the phosphor main part (Zn _1.9 SiO ₄ Mn _0.1 ), the surface Zn / Si ratio is 1 (conversion method 1). It can be seen that it is desirable that the ratio is 0.5 or more and 1.7 or more in (Conversion method 2) from both the viewpoints of the “initial” relative light emission luminance and the light emission luminance maintenance rate.

Next, as shown in Table 3, in Examples 68 to 75, in any addition amount (total amount; 0.001 to 0.005 mol), it is higher than Comparative Example 1 containing no additive. It has a relative light emission luminance maintenance rate. From this result, the case where two or all of the three elements selected from the group consisting of Ti, Zr and Hf are added to the phosphor main part (Zn _1.9 SiO ₄ Mn _0.1 ). It can also be determined that it has a high effect of suppressing deterioration over time.

When considering the data in Tables 1 to 3 above, it is desirable to form the G phosphor 250G with the following configuration.
Regarding the composition of the G phosphor 250G, at least one element is selected from the element group composed of Ti, Zr and Hf with respect to the phosphor main part (Zn _1.9 SiO ₄ Mn _0.1 ). It is desirable to add it. The total addition ratio of the elements (Ti, Zr, Hf) to 1 mol of the phosphor main part (Zn _1.9 SiO ₄ Mn _0.1 ) is preferably in the range of 0.0001 mol to _0.01 mol. It is more desirable to set it in the range of .0005 mol to 0.005 mol. The surface Zn / Si ratio is preferably 1.5 or more in (Conversion method 1) and 1.7 or more in (Conversion method 2).

7-4. Confirmation of superiority in PDP Next, the superiority of PDP will be described with reference to FIG. FIG. 5 shows a fixed display of one green color for both the PDP using the G phosphor according to Comparative Example 1 and the PDP using the phosphor according to Example 65, and the usage time (display) (Elapsed time) is a plot of the transition of the emission luminance maintenance rate. The light emission luminance maintenance ratio in FIG. 5 is expressed as a percentage when the relative luminance at the start of lighting in each PDP is “100”.

The manufacturing method of each PDP used for this confirmation is as follows, for example.
In the production of the PDP according to the example, the G phosphor (average particle size 2 μm) according to the example 65 is 30 wt%, ethyl cellulose (molecular weight is about 200,000) 4.5 wt%, and butyl carbitol acetate 65 as a solvent. 0.5 wt% was kneaded by a three-roll mill to obtain a phosphor ink having physical properties of a viscosity of 2.0 to 6.0 Pa · s (2000 to 6000 cps). This phosphor ink was applied between the partition walls 24 using the meniscus method, dried, and then heat treated at 500 ° C. for 10 minutes to form a G phosphor layer 25G.

The components of the phosphor ink are not limited to those described above, and other methods (for example, a screen printing method and a line jet method) may be used as the coating method.
The P phosphor G layer 25G of the PDP according to the example was configured by the above method, and the PDP according to the example was obtained by using a conventional method for other portions.
On the other hand, the PDP according to the comparative example does not contain any of the phosphors of the comparative example 1, that is, Ti, Zr, and Hf, and the surface Zn / Si ratio is 1.0 (converted by the conversion method 1 evaluation method). In the evaluation method of Method 2, the one using 1.2) Mn-activated zinc silicate phosphor was applied.

As shown in FIG. 5, in the PDP according to the comparative example, 3000 hr. At the time of elapse, the emission luminance maintenance ratio has decreased to about 82%, and it is 6000 hr. It has dropped to about 79% at the time. In contrast, in the PDP according to the embodiment, 3000 hr. At the time of lapse, it has an emission luminance maintenance ratio of about 93%, and it is 6000 hr. About 91% is maintained even at the time.
Therefore, in the PDP 1 including the G phosphor 250G according to the present embodiment, the luminance deterioration with time is suppressed and the emission luminance is suppressed as compared to the PDP according to the comparative example in which none of Ti, Zr, and Hf is added to the G phosphor. The seizure phenomenon due to the decrease in the thickness is surely suppressed.
(Embodiment 2)
Hereinafter, the PDP according to the second embodiment will be described. However, the difference between the PDP according to the present embodiment and the PDP 1 according to the first embodiment is only the composition of the G phosphor that constitutes the G phosphor layer, and the following description will focus on this point. To.

1. Composition of G phosphor In the PDP according to the second embodiment, a material having the following composition is used as the G phosphor constituting the G phosphor layer.
G phosphor; Zn _1.9 SiO ₄ : 0.1Mn: 0.0005W
That is, the G phosphor according to the second embodiment has tungsten (W) as the additive element α. And, the addition ratio of W is within the range of 0.00005 mol or more and 0.01 mol or less with respect to 1 mol of (Zn _1.9 SiO ₄ Mn _0.1 ) which is the phosphor main part, as shown in the above composition formula. It has become. Note that the addition ratio of _W, with respect to _{(Zn 1.9 SiO 4 Mn 0.1)} 1mol, within 0.005mol the range above 0.0001 mol, _{or, (Zn 1.9 SiO 4 Mn 0} . ₁ ) It is more desirable that the amount be in the range of 0.00005 mol or more and 0.0005 mol or less with respect to ₁ mol.

Also in the G phosphor according to the second embodiment, as in the first embodiment, the atomic ratio of zinc (Zn) to silicon (Si) on the particle surface and the vicinity of the element (surface Zn / Si ratio) ) Is preferably set to 1.5 or more in (Conversion Method 1), and is set to 1.7 or more in (Conversion Method 2).
2. Advantages of G phosphor and PDP As described above, in the G phosphor according to the present embodiment, W is added in the above ratio with respect to the phosphor main part (Zn _1.9 SiO ₄ Mn _0.1 ). Therefore, there is little segregation of silicon (Si) on the particle surface and the vicinity thereof (for example, a region from the particle surface to a depth of 4 nm), and the crystallinity is high.

In addition, in the G phosphor according to the present embodiment, as with the G phosphor 250G according to the first embodiment, it is difficult to cause deterioration with time due to driving, and high light emission efficiency can be maintained regardless of the length of driving time. is there.
In the present embodiment, by defining the W addition ratio in the G phosphor within the above range, both high luminous efficiency and deterioration resistance can be achieved. In the G phosphor according to the present embodiment, the (surface Zn / Si ratio) is 1.5 or more in (Conversion method 1) and 1.7 or more in (Conversion method 2). As in the first embodiment, the effect of suppressing deterioration with time is even higher. Therefore, the PDP including the G phosphor layer having the G phosphor hardly deteriorates with time due to the driving of the G phosphor layer 25G, and maintains high luminous efficiency regardless of the driving time. High image quality.

Note that, in the G phosphor according to the present embodiment, when the W content is increased, the deterioration resistance is improved, but the light emission efficiency tends to decrease, and an appropriate amount needs to be contained.
3. G phosphor manufacturing method The G phosphor manufacturing method according to the present embodiment is different from the first embodiment in that W oxide is used instead of Ti oxide in the raw material used in the raw material mixing step. Is different. That is, for example, the following raw materials are used for manufacturing the G phosphor according to the present embodiment.

MnCO ₃ (for example, manufactured by Kojundo Chemical Laboratory Co., Ltd.): 0.10 mol (1.076 g)
ZnO (for example, manufactured by Kojundo Chemical Laboratory Co., Ltd.): 1.90 mol (13.636 g)
SiO ₂ (for example, manufactured by Kojundo Chemical Laboratory Co., Ltd.): 1.00 mol (5.298 g)
WO ₃ (for example, manufactured by Kojundo Chemical Laboratory Co., Ltd.): 0.0005 mol (0.006 g)
Other processes related to the manufacturing method can be the same as those in the first embodiment, and the description thereof will be omitted.

4). Variation of Additive Element α in G Phosphor In Embodiment 2, W is adopted as an example of an additive element for the phosphor main part (Zn _1.9 SiO ₄ Mn _0.1 ), but molybdenum (Mo ), Or a combination of Mo and W. Even when such an element is employed, the addition ratio is more preferably in the range of 0.00005 mol to 0.01 mol with respect to 1 mol of the phosphor main part (Zn _1.9 SiO ₄ Mn _0.1 ). Is in the range of 0.0001 mol or more and 0.005 mol or less, or in the range of 0.00005 mol or more and 0.0005 mol or less. For example, it can be set as the following composition.

Zn _1.9 SiO ₄ Mn _0.1 : 0.0005Ti: 0.0005Mo
Zn _1.9 SiO ₄ Mn _0.1 : 0.0005Zr: 0.0005Mo: 0.0005W
Various other variations can be adopted.
5). Confirmation of Superiority Hereinafter, confirmation results of the superiority of the G phosphor according to the present embodiment and the PDP including the same will be described with reference to Tables 4 to 6 and FIGS. In this confirmation, the compositions of the samples used are shown in Tables 4-6.

表４〜６に示すように、本確認においては、添加元素の種類およびその添加量を変化させて各サンプル（実施例７６〜１１９）を作製した。また、比較例１としては、上記実施の形態１における確認で用いたのと同様に、Ｔｉ、Ｚｒ、Ｈｆ、ＭｏおよびＷの何れも添加していない従来のＧ蛍光体を用意した。なお、各表４〜６の中で、「元素の添加量」および「表面Ｚｎ／Ｓｉ比分析値」は、上記と同様であるので、あらためての説明を省略する。

As shown in Tables 4-6, in this confirmation, each sample (Examples 76-119) was produced by changing the type of additive element and the amount added. As Comparative Example 1, a conventional G phosphor not containing any of Ti, Zr, Hf, Mo, and W was prepared in the same manner as used in the confirmation in the first embodiment. In each of Tables 4 to 6, “element addition amount” and “surface Zn / Si ratio analysis value” are the same as described above, and thus a description thereof is omitted.

5-1. Sample (Examples 76 to 83)
As shown in Table 4, in Examples 76 to 83, the addition amount was changed in the range of 0.00003 to _0.01 mol with respect to 1 mol of the phosphor main part (Zn _1.9 SiO ₄ Mn _0.1 ). While adding W. In Examples 76 to 83, the surface Zn / Si ratio was adjusted to “1.0” (conversion method 1) and “1.2” (conversion method 2).

(Examples 84 to 92)
In Examples 84 to 92, Mo was added to the phosphor main part (Zn _1.9 SiO ₄ Mn _0.1 ). The addition amount of Mo in the embodiment 84-16, similar to the W of Examples 76 to 83, the phosphor main portion _{(Zn 1.9 SiO 4 Mn 0.1)} 1mol, 0.00003~ 0.01 mol. The surface Zn / Si ratio was the same as in Examples 76 to 83. When Mo is to be added to the phosphor main part, MoO ₃ that is a Mo source may be used. There are no changes to other factors related to the manufacturing method.

(Examples 93 to 97)
In Examples 93 to 97, both Mo and W were added to the phosphor main part (Zn _1.9 SiO ₄ Mn _0.1 ). As shown in Table 4, the amount of element added was such that the total in each sample was 0.00005 to 0.02 mol per mol of the phosphor main part.

In Examples 93 to 97, the surface Zn / Si ratio is set to “1.0” in (Conversion method 1) and “1.2” in (Conversion method 2).
(Examples 98 to 117)
As shown in Table 5, in Examples 98 to 117, one element of Mo and W was added to the phosphor main part (Zn _1.9 SiO ₄ Mn _0.1 ). The addition amount of the element in each Example 98-117 is as showing in Table 5, the group of Examples 98-101, the group of Examples 102-109, the group of Examples 110-113, and Example The surface Zn / Si ratio was changed between the groups 114 to 117. Specifically, in Examples 98 to 101, (Conversion Method 1) is “1.2”, (Conversion Method 2) is “1.4”, and in Examples 102 to 109 (Conversion Method 1) “1.5”, “1.7” in (Conversion method 2), and in Examples 110 to 113, “1.7” in (Conversion method 1) and “2.0” in (Conversion method 2) In Examples 114 to 117, “2.0” was set for (Conversion method 1), and “2.3” was set for (Conversion method 2).

In addition, about the adjustment method to the surface Zn / Si ratio in each Example, it is the same as the method employ | adopted in Examples 41-67 in the confirmation in the said Embodiment 1. FIG. However, also in Examples 98 to 117 in this confirmation, the method for adjusting the surface Zn / Si ratio is not limited to this, and other various methods can be adopted.
(Examples 118 and 119)
As shown in Table 6, in Examples 118 and 119, both Mo and W were added to the phosphor main part (Zn _1.9 SiO ₄ Mn _0.1 ) as in Examples 93 to 97. Added. The total amount of elements added was 0.0007 mol (per 1 mol of phosphor main part) in Example 118 and 0.001 mol (per mol of phosphor main part) in Example 119.

In Examples 118 and 119, the surface Zn / Si ratio was set to “1.5” in (Conversion method 1) and “1.7” in (Conversion method 2).
5-2. Method for performance evaluation of phosphor The confirmation in Embodiment 1 and the performance evaluation were performed on the samples of Examples 76 to 119 and Comparative Example 1. The results are shown in Tables 4-6.

In the present embodiment in which at least one element of Mo and W is added to the phosphor main part (Zn _1.9 SiO ₄ Mn _0.1 ), the emission luminance maintenance ratio in the phosphor is as follows. It may be 74% or more of Comparative Example 1 and more preferably 80% or more. Further, the relative light emission luminance value in the “initial stage” may be 85% or more with respect to Comparative Example 1, and more preferably 90% or more.

5-3. Consideration As shown in Table 4, in Examples 76 to 83 in which W was added to the phosphor main part (Zn _1.9 SiO ₄ Mn _0.1 ), the amount of element added (0.00003 to 0.003). 01 mol), it has a higher “initial” relative light emission luminance than Comparative Example 1. From this result, it can be determined that the phosphors of Examples 76 to 83 have a high effect of suppressing deterioration with time. In particular, in the phosphors according to Examples 77 to 83, the emission luminance maintenance rate is 80% or more, and the amount of W added is 1 mol of the phosphor main part (Zn _1.9 SiO ₄ Mn _0.1 ). On the other hand, it is preferable to set it as the range of 0.00005-0.01 mol.

  Furthermore, in the phosphors according to Examples 78 to 82, the relative light emission luminance in the “initial stage” is 95% or higher than that of Comparative Example 1, and the light emission luminance maintenance ratio is 80% or higher. From this, like the fluorescent substance which concerns on Examples 78-82, as addition amount of W, 0.0001-0.005 mol (with respect to 1 mol of fluorescent substance main parts) is more preferable. In addition, the phosphors according to Examples 77 to 79 have a relative light emission luminance of “initial” of 99% or higher than that of Comparative Example 1 and a light emission luminance maintenance rate of 80% or higher. The amount is more preferably 0.00005 to 0.0005 mol (relative to 1 mol of the phosphor main part).

In Examples 84 to 92 in which Mo was added to the phosphor main part (Zn _1.9 SiO ₄ Mn _0.1 ), the comparative example was used regardless of the amount of addition (0.00003 to 0.01 mol). Compared to 1, it has a higher emission luminance maintenance rate. From this, it can be considered that the phosphors according to Examples 84 to 92 have an effect of suppressing deterioration with time. In particular, in the phosphors according to Examples 85 to 92, the emission luminance maintenance ratio is 80% or more. From this, the addition amount of Mo is 0.00005 to 0.01 mol (phosphor main part). 1 mol) is preferred.

  Furthermore, in the phosphors according to Examples 86 to 90, the relative light emission luminance at the “initial stage” is 95% or higher than that of Comparative Example 1, and the light emission luminance maintenance ratio is 80% or higher. Therefore, the addition amount of Mo is preferably in the range of 0.0001 to 0.005 mol (relative to 1 mol of the phosphor main part). Further, in the phosphors according to Examples 85 to 87, the relative light emission luminance in the “initial stage” is 98% or higher than that of Comparative Example 1, and the light emission luminance maintenance ratio is 80% or higher. Therefore, the addition amount of W is more preferably in the range of 0.00005 to 0.0005 (with respect to 1 mol of the phosphor main part).

Next, as shown in Table 4, Examples 93 to 97 have a higher emission luminance maintenance rate than Comparative Example 1 regardless of the amount of addition (total amount; 0.00005 to 0.02 mol). doing. From this result, it can be judged that the phosphors according to Examples 93 to 97 have an effect of suppressing deterioration with time, and as an additive element to be contained in the phosphor main part (Zn _1.9 SiO ₄ Mn _0.1 ). It is clear that both elements Mo and W may be contained in combination.

Furthermore, when Mo and W are included in combination, the relative light emission luminance in the “initial stage” is 90% or more, and the light emission luminance maintenance ratio is 80% or more. More preferably, the total of the elements is in the range of 0.00005 to 0.01 mol (relative to 1 mol of the phosphor main part).
As shown in Table 5, in each of Examples 98 to 117, an improvement in the emission luminance maintenance ratio was observed as compared with Comparative Example 1 containing no additive. From this result, it is determined that the phosphors according to Examples 98 to 117 have an effect of suppressing deterioration with time, as in Examples 76 to 97.

Further, as shown in FIG. 5, when the surface Zn / Si ratio is 1.5 (conversion method 1) or more (1.7 or more in the case of conversion method 2), the emission luminance maintenance ratio (100 hours) The latter) is higher than the other cases, and it can be said that the effect of suppressing deterioration with time of the phosphors according to Examples 102 to 117 is particularly high.
As shown in Table 6, in the phosphors according to Examples 118 and 119, in any addition amount (total amount: 0.0007 to 0.001 mol), compared with Comparative Example 1 containing no additive. And has a high emission luminance maintenance rate. From these results, it is determined that the phosphors according to Examples 118 and 119 have a higher temporal deterioration suppressing effect than Comparative Example 1.

From these results, Mo and W are combined and added to the phosphor main part, and the surface Zn / Si ratio is “1.5” in (Conversion method 1) and 1.7 in (Conversion method 2). By adjusting, it is possible to effectively suppress the deterioration of the phosphor over time.
5-4. Confirmation of superiority in PDP Next, superiority as a PDP will be described with reference to FIG. FIG. 7 shows a fixed display of one green color for both the PDP using the G phosphor according to Comparative Example 1 and the PDP using the phosphor according to Example 114, and the usage time (display) (Elapsed time) is a plot of the transition of the emission luminance maintenance rate. Note that the emission luminance maintenance ratio in FIG. 7 is expressed as a percentage when the relative luminance at the start of lighting in each PDP is “100”.

The manufacturing method of each PDP used for this confirmation is the same as the method in the first embodiment except for the composition of the G phosphor used.
As shown in FIG. 7, in the PDP according to the comparative example, as described above, 3000 hr. At the time of elapse, the emission luminance maintenance rate is about 82%, 6000 hr. It has dropped to about 79% at the time. On the other hand, in the PDP according to the present embodiment, 3000 hr. At the time of lapse, it has an emission luminance maintenance ratio of about 93%, and it is 6000 hr. About 92% is maintained even at the time.

Therefore, in the PDP including the G phosphor according to the present embodiment, the luminance deterioration with time is suppressed compared to the PDP according to the comparative example in which none of Ti, Zr, Hf, Mo, and W is added to the G phosphor. In addition, the image sticking phenomenon due to the decrease in emission luminance is reliably suppressed.
(Other matters)
About the said Embodiment 1, 2, the example of this invention is shown and this invention is not limited to these. For example, in the first and second embodiments, the case where the G phosphor according to the present invention is applied to the PDP has been described. However, the same effect can be obtained even when applied to other uses such as a fluorescent lamp. . However, the effect of the present invention can be remarkably obtained by applying the present invention to a PDP having a discharge space smaller than that of a fluorescent lamp or the like and a generated ultraviolet ray having a short wavelength.

In addition, the composition of the G phosphor according to the first and second embodiments needs to be adjusted as appropriate according to required characteristic values such as chromaticity, luminous efficiency, deterioration resistance, and afterglow characteristics. In particular, there is no particular limitation on this, but as a specific example, although the light emission characteristics can be improved by slightly increasing the amount of Si, deterioration resistance is generally deteriorated.
In the G phosphors according to the first and second embodiments, the amount of Mn activation can be adjusted as appropriate. This is not particularly limited, but is generally in the range of 0.01 to 0.2 mol in practice. For example, when the Mn activation amount is set to be small with respect to the above-described range, the afterglow time of light emission becomes long, and a problem such as an afterimage phenomenon occurs when considering application to video display applications such as PDP. . Conversely, when a large amount of Mn activation is set with respect to the above-described range, there is a problem that the light emission efficiency is lowered.

  Further, in the PDP 1 applied in the first and second embodiments, a structure having a grid-structured partition wall 24 is adopted. Of course, a structure having a stripe-shaped partition wall or a structure having a meander-structured partition wall is adopted. It can also be applied to. Further, in the first and second embodiments, the present invention is applied to the AC type PDP. However, the present invention can also be applied to the DC type PDP.

  The present invention can be applied to a PDP, a fluorescent lamp, or the like that needs to suppress a decrease in light emission efficiency even by long-term driving.

It is a principal part perspective view (partial cross section figure) which shows the principal part of PDP1 which concerns on embodiment. It is a step figure showing a manufacturing method of green phosphor 250G. It is a temperature profile figure which shows transition of the temperature in baking step S3 in the manufacture process of the green fluorescent substance 250G. In each fluorescent substance of an Example and a comparative example, it is a characteristic view which shows the relationship between the surface Zn / Si ratio analysis value, an initial stage light emission brightness | luminance, and a light emission brightness maintenance factor. In each PDP of an Example and a comparative example, it is a characteristic view which shows the relationship between use time and a light emission brightness maintenance factor. In each fluorescent substance of an Example and a comparative example, it is a characteristic view which shows the relationship between the surface Zn / Si ratio analysis value, an initial stage light emission brightness | luminance, and a light emission brightness maintenance factor. In each PDP of an Example and a comparative example, it is a characteristic view which shows the relationship between use time and a light emission brightness maintenance factor.

Explanation of symbols

1. PDP
10. Front panel 11. Front substrate 12. Display electrode pair 12a. Scan electrode 12b. Sustain electrode 13. Dielectric layer 14. Protective layer 20. Rear panel 21. Rear substrate 22. Data electrode 23. Dielectric layer 24. Septum 25. Phosphor layer 25R. R phosphor layer 25G. G phosphor layer 25B. B phosphor layer 30. Discharge space 250G. G phosphor 250G ₁ . Manganese compound 250G ₂ . Zinc compound 250G ₃ . Silicon dioxide 250G ₄ . Titanium oxide 250G ₁₀ . Mixed ground powder

Claims (14)

A phosphor having a phosphor main part composed of zinc silicate as a base material and manganese as an activator,
An element comprising at least one of titanium, zirconium and hafnium is added to the phosphor main part. 2. The phosphor according to claim 1, wherein the additive element is added at a ratio of 0.0001 mol to 0.01 mol in total with respect to 1 mol of the phosphor main part. 2. The phosphor according to claim 1, wherein the additive element is added in a ratio of 0.0005 mol to 0.005 mol in total with respect to 1 mol of the phosphor main part. A phosphor having a phosphor main part composed of zinc silicate as a base material and manganese as an activator,
A phosphor characterized in that at least one element of molybdenum and tungsten is added to the phosphor main part. The phosphor according to claim 4, wherein the additive element is added in a ratio of 0.00005 mol to 0.01 mol with respect to 1 mol of the phosphor main part. The phosphor according to claim 4, wherein the additive element is added in a ratio of 0.0001 mol to 0.005 mol in total with respect to 1 mol of the phosphor main part. The phosphor according to claim 4, wherein the additive element is added in a ratio of 0.00005 mol to 0.0005 mol in total with respect to 1 mol of the phosphor main part. Having a particulate appearance,
8. The phosphor according to claim 1, wherein each particle has an atomic ratio of zinc to silicon in the surface and in the vicinity of the particle is 1.5 or more. The phosphor according to claim 8, wherein the neighboring region is a region from the particle surface to a depth of 4 nm. The phosphor according to claim 8 or 9, wherein the atomic number ratio is a value obtained by measurement using X-ray photoelectron spectroscopy using AlKα rays as irradiation X-rays. The atomic ratio is calculated from the relative number of silicon atoms in the particle surface and the vicinity thereof converted from the photoelectron peak area caused by 2p orbitals in silicon atoms and the photoelectron peak area caused by 2p3 orbitals in zinc atoms. 11. The phosphor according to claim 10, wherein the phosphor is defined by a ratio with respect to the number of relative zinc atoms in the surface of the particle and the vicinity thereof. The atomic ratio is calculated from the relative number of silicon atoms in the particle surface and its neighboring region converted from the photoelectron peak area due to the 2p orbital in the silicon atom and the photoelectron peak area due to the 3p orbital in the zinc atom. 11. The phosphor according to claim 10, wherein the phosphor has a value of 1.7 or more when defined by a ratio to the number of relative zinc atoms in the particle surface and the vicinity thereof. A plasma display panel having a pair of substrates disposed to face each other with a space between them, and having a phosphor layer formed on one of the pair of substrates facing the space,
A plasma display panel, wherein at least a partial region of the phosphor layer is formed using the phosphor according to any one of claims 1 to 12. 14. The plasma display panel according to claim 13, wherein at least a partial region of the phosphor layer is a region that emits green light upon incidence of ultraviolet light as excitation light.

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