JP4582324B2 - Zirconium and manganese containing phosphates - Google Patents

Description

The present invention relates to zirconium-time及 beauty manganese-containing phosphate having characteristic fluorescence properties.

Zirconium (Zr) or hafnium (Hf) becomes a mother crystal to which a light emitting element is added in the form of CaZrO ₃ or the like in the phosphor (see Patent Document 1: Japanese Patent Laid-Open No. 8-283713), or aluminate and aluminate It is added to a salt-based mother crystal to increase the afterglow of fluorescence (see Patent Document 2: Japanese Patent Laid-Open No. 8-73845), or added to oxychloride or oxybromide of rare earth elements together with Ce. Thus, it is known to have a function of improving the conversion efficiency of radiation-excited phosphors (see Patent Document 3: Japanese Patent Application Laid-Open No. 11-349939).
However, regarding a system in which only zirconium or hafnium is added as a small amount component to a simple transparent crystal that does not exhibit active light characteristics by itself, the properties such as fluorescence have hardly been studied.

JP-A-8-283713 JP-A-8-73845 Japanese Patent Laid-Open No. 11-349939

The present invention has been made in view of the above circumstances, and an object thereof is to provide a zirconium arm及 beauty manganese-containing phosphate fluoresce in the visible region when excited by light in the vacuum ultraviolet region.

The present inventor has conducted extensive investigations to achieve the above objects, the total atoms, Z r 1 atomic% to 15 atomic% or less, 0.01 atomic% or more Mn 5 atomic% or less, alkaline earth When a phosphate containing 3 to 35 atomic percent of a metal group element and 5 to 20 atomic percent of P is excited at a wavelength in the vacuum ultraviolet region, a peak wavelength of 500 to It has been found that it emits light in a green to orange region of 600 nm, particularly 510 to 590 nm, has a high luminance, and is useful as a phosphor.

In recent years, phosphors excited in the vacuum ultraviolet region have been researched and developed for application to plasma display panels and rare gas discharge lamps that do not use mercury. It has been found that phosphors exhibiting near-ultraviolet light emission under vacuum ultraviolet excitation can be obtained by adding zirconium or hafnium with rare earth phosphates, silicates, aluminates, etc. as mother crystals. (see Japanese Patent Laid-open 2005-298583). Furthermore, the present inventor has shown that when a predetermined amount of manganese in addition to zirconium or hafnium is added to the mother crystal as described above, the phosphor emits light in the visible region when excited at a wavelength in the vacuum ultraviolet region. emission peak wavelength determined by the type of crystal be found that (Japanese open No. 2005-298584, see the 2006-104049 JP) to spread wide range of red from blue, for further applications, the luminous intensity Improvement is desired, and the present invention has been made in view of this point.

That is, the present invention provides the following phosphates.
_{(1) C aZr (PO 4} ) 2 to obtain the addition-solid solution M n, the total atoms, Z r 1 atomic% to 15 atomic% or less, Mn of 0.01 atomic% to 5 atomic % Or less, 3 to 35 atom% of an alkaline earth metal element, and P to 5 to 20 atom% in proportions of 500 to 600 nm by excitation with vacuum ultraviolet light of 130 to 220 nm, respectively. A phosphate characterized by emitting fluorescence in the green to orange region.
(2 ) The phosphate according to (1), which is ( Ca _0.93 Mn _0.07 ) Zr (PO ₄ ) ₂ .
( 3 ) The phosphate according to (1), which is (Ca _0.973 Mn _0.027 ) Zr (PO ₄ ) ₂ .

  The phosphate of the present invention to which zirconium or hafnium and manganese are added has a wavelength in the range from green to orange having a wavelength of 500 to 600 nm when excited with light in the vacuum ultraviolet region, such as 147 nm of resonance line emission of xenon atoms. Development of fluorescent materials such as cathode ray lamps that do not use mercury and fluorescent materials such as backlights for liquid crystal displays, and monitoring and display of vacuum ultraviolet light in industrial devices using vacuum ultraviolet light such as semiconductor manufacturing processes can be expected.

  In the phosphate according to the present invention, Zr or Hf is 1 atom% or more and 15 atom% or less, Mn is 0.01 atom% or more and 5 atom% or less, and alkaline earth metal element is 3 atom% or more with respect to all atoms. It is a phosphate containing 35 atomic percent or less and P in a proportion of 5 atomic percent to 20 atomic percent.

Here, as a mother crystal used for the phosphate of the present invention, the composition formula identified by powder X-ray diffraction is Mg ₂ P ₂ O ₇ , Ca ₃ (PO ₄ ) ₂ , CaZr (PO ₄ ) _2. , SrMgP ₂ O ₇ , BaZr (PO ₄ ) ₂ , Ba ₇ Zr (PO ₄ ) ₆ and other alkaline earth metal-containing phosphates can be suitably selected.

  The Zr, Hf, and Mn-containing phosphate of the present invention is obtained by adding and solid-solving Zr, Hf, and Mn to the above-mentioned mother crystal. In view of the bond distance in the medium, both Zr, Hf, and Mn are uniformly contained in a certain amount or are easily dissolved, and the structure is observed when containing only Zr or Hf. It is also advantageous from the viewpoint of efficiency of transmitting light emission energy to Mn and causing visible light emission. The alkaline earth metal elements constituting these mother crystals may be used alone or in combination of two or more elements.

  In the present invention, Zr or Hf is added to the above mother crystal in an amount of 1 atom% to 15 atom%, preferably 3 atom% to 12 atom% of all atoms. Further, Mn is added in an amount of 0.01 atomic% to 5 atomic%, preferably 0.1 atomic% to 2 atomic% of all atoms. When the amount of Zr or Hf added is less than 1 atomic% of all atoms, the absorption of vacuum ultraviolet light contributing to the excitation of light emission is not sufficient, the light emission becomes weak, and the amount of Mn added is 0.2% of all atoms. If it is less than 01 atomic%, fluorescence emission cannot be substantially observed. On the other hand, even if Zr or Hf is added in excess of 15 atomic% and Mn exceeds 5 atomic% and the substitution is increased, the degree to which the excitation energy is lost while traveling through nearby atoms without contributing to light emission increases. Moreover, among Zr and Hf, Zr is more preferable from the viewpoint of abundant resources and price.

  Regarding the ratio of alkaline earth metal and phosphorus contained in the phosphate of the present invention, the alkaline earth metal is 3 atomic% to 35 atomic% of all atoms, preferably 4 atomic% to 25 atomic%. It is. When the proportion of the alkaline earth metal is less than 3 atomic%, a compound that does not contribute to light emission is likely to be generated, and when it exceeds 35 atomic%, the amount of phosphorus described later decreases as a result. In addition, from the viewpoint of the bond distance of the elements constituting the crystal, it is preferable that 50 atomic% or more, particularly 60 atomic% or more of the entire alkaline earth metal is calcium. The upper limit is not particularly limited, and 100 atomic% may be calcium.

Further, the phosphorus content is 5 atom% or more and 20 atom% or less, preferably 10 atom% or more and 20 atom% or less of all atoms. When the phosphorus content is less than 5 atomic%, a large number of independent oxygen atoms that do not form phosphate ions are contained, and in such a system, light emission is weakened. In addition, containing phosphorus in excess of 20 atomic% is not realized unless phosphorus is not a formal pentavalent low valence, that is, a phosphite group or a hypophosphite group. In this case, it is disadvantageous in terms of chemical stability, and light emission is actually weakened.
The content ratio of each element can be obtained based on quantitative determination by ICP emission spectroscopy after decomposing the sample into a solution.

Next, the manufacturing method of the phosphate of this invention is described.
The production method of the present invention is not particularly limited, but as raw materials, powders such as oxides, carbonates and oxalates containing alkaline earth metal, zirconium or hafnium, and manganese elements, phosphoric acid, and ammonium phosphate A raw material containing phosphorus such as 800 ° C. or higher and 1800 ° C. or lower, especially 850 ° C. or higher and 1500 ° C. or lower for 30 minutes or longer and 24 hours or shorter, particularly 1 hour or longer and 8 hours or shorter. Is the most common and has a wide range of applications, and can be suitably employed in the present invention. In this case, it is preferable to measure and mix the metal element according to the target composition. However, it is also effective to mix the phosphate group raw material more than the target composition within the range of the equivalent amount to about twice. . Moreover, in order to accelerate | stimulate reaction, you may add fluxes, such as an alkali metal fluoride and a boric acid.

  Moreover, it replaces with a part of said raw material, uses the phosphate containing 1 or more types of each said metal element, mixes other raw materials as needed, and heats within the said temperature range and time, A method of reacting can also be preferably used.

  Further, a water-soluble compound containing a part or all of the metal elements constituting the phosphate of the present invention is reacted with a water-soluble compound containing a phosphate group in the form of a solution to form a precipitate, which is dried or It is also an effective method to synthesize the target phosphate by baking and dehydrating or to use it as an intermediate.

  When the powders are mixed, the mixing method is not particularly limited, but can be performed using a mortar, a fluid mixer, a tilt rotary mixer, or the like.

  The atmosphere in which the heating reaction is performed can be selected according to the type of mother crystal such as air, inert gas atmosphere, reducing gas atmosphere, etc. Generally, an inert gas atmosphere such as nitrogen or argon is divalent to Mn. It is preferable because it is easy to keep in this state.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not limited to the following example.

[Synthesis of starting materials]
(1) Manganese oxalate Manganese oxalate used in the following synthesis was a precipitate produced by mixing an aqueous manganese chloride solution and an aqueous ammonium oxalate solution, and was filtered and dried.
(2) Calcium / manganese carbonate Calcium / manganese carbonate is dissolved in an aqueous solution in which calcium chloride and manganese chloride are dissolved in accordance with the target composition, and ammonium hydrogen carbonate (NH ₄ HCO ₃₎ having twice the total number of moles of Ca and Mn. ) An aqueous solution was added to form a precipitate, which was obtained by drying.
(3) phosphate of zirconium oxide chloride, zirconium (ZrOCl ₂ · 8H ₂ O, guaranteed reagent) and 193.4g was dissolved in pure water 900 cm ^3, this oxalic acid _{(H 2 C 2 O 4 ·} 2H 2 O, special grade reagent) A solution prepared by dissolving 151.3 g in 1400 cm ³ of pure water was added, and 259 g of 75% phosphoric acid aqueous solution was further added thereto with stirring. Concentrated ammonia was added to adjust the pH of the solution to about 2, and then 85 ° C. in a water bath. And reacted for 15 hours with stirring. The resulting precipitate was filtered and dried to obtain zirconium phosphate.
(4) Calcium hydrogen phosphate Calcium hydrogen phosphate (CaHPO ₄ ) is produced by dispersing calcium hydroxide in water, adding a slight excess of phosphoric acid, stirring and reacting, and filtering and drying. A thing was used.

[Example 1]
Calcium manganese carbonate (4.05 g) and zirconium phosphate (12.21 g) were mixed in an automatic mortar, placed in an alumina crucible, and heated to 1200 ° C in an electric furnace with a nitrogen gas flow of 0.7 dm ³ (standard condition) per minute. Then, after being kept for 3 hours, it was cooled in the same nitrogen stream. The obtained sample was pulverized with a mortar to form powder. The composition of the obtained sample is
(Ca _0.93 Mn _0.07 ) Zr (PO ₄ ) ₂
The powder X-ray diffraction pattern almost coincided with CaZr (PO ₄ ) ₂ . When calculated from the composition formula, Zr is 8.3 atomic% of all atoms, Mn is 0.58 atomic%, Ca is 7.8 atomic%, and P is 16.7 atomic%.

[Example 2]
3.89 g of calcium carbonate (reagent 99.99% CaCO ₃ , manufactured by Wako Pure Chemical Industries, Ltd.)
Automatically 0.173 g of manganese oxalate, 4.93 g of zirconium oxide (ZrO ₂ ) (TZ-0, manufactured by Tosoh Corporation), and 11.09 g of diammonium hydrogen phosphate ((NH ₄ ) ₂ HPO ₄ , reagent special grade) The mixture was mixed in a mortar, placed in an alumina crucible, heated to 1200 ° C. in an electric furnace with nitrogen gas flowing at 0.7 dm ³ (standard state) per minute, kept for 3 hours, and then cooled in the same nitrogen stream. The obtained sample was pulverized with a mortar to form powder. The composition of the obtained sample is
(Ca _0.973 Mn _0.027 ) Zr (PO ₄ ) ₂
The powder X-ray diffraction pattern almost coincided with CaZr (PO ₄ ) ₂ . When calculated from the composition formula, Zr is 8.3 atomic% of all atoms, Mn is 0.22 atomic%, Ca is 8.1 atomic%, and P is 16.7 atomic%.

[Comparative Example 1]
3.60 g of calcium carbonate, aluminum oxide (Al ₂ O ₃ ) (Tymicron TM-DA, manufactured by Daimei Chemical Industry Co., Ltd.) 4.08 g, silicon oxide (SiO ₂ ) (1-FX, manufactured by Tatsumori) 81 g, manganese oxalate 0.256 g, zirconium oxide 0.099 g, and sodium fluoride (reagent special grade NaF, manufactured by Wako Pure Chemical Industries, Ltd.) 0.067 g were mixed in an automatic mortar, placed in an alumina crucible, and nitrogen gas was added. Heated to 1200 ° C. in a flowing electric furnace at 0.7 dm ³ (standard state) per minute, kept for 4 hours, and then cooled in the same nitrogen stream. The obtained sample was pulverized with a mortar to form powder. The composition of the obtained sample is
(Ca _0.9 Mn _0.04 Zr _0.02 Na _0.04 ) Al ₂ Si ₂ O ₈
When calculated from the composition formula, Zr is 0.15 atomic% of all atoms, Mn is 0.31 atomic%, Ca is 6.9 atomic%, and P is not included.

[Comparative Example 2]
Yttrium oxide (Y ₂ O ₃ ) (4N product manufactured by Shin-Etsu Chemical Co., Ltd.) 2.26 g, aluminum oxide 3.82 g, boric acid (reagent special grade H ₃ BO ₃ , manufactured by Wako Pure Chemical Industries, Ltd.), manganese oxalate 0.395 g and 0.308 g of zirconium oxide were mixed in an automatic mortar, placed in an alumina crucible, heated to 1100 ° C. in an electric furnace with nitrogen gas flowing at 0.7 dm ³ (standard condition) per minute, and maintained for 3 hours. Then, it was cooled in the same nitrogen stream. The obtained sample was pulverized with a mortar to form powder. The composition of the obtained sample is
(Y _0.8 Mn _0.1 Zr _0.1 ) Al ₃ (BO ₃ ) ₄
When calculated from the composition formula, Zr is 0.50 atomic% of all atoms, Mn is 0.50 atomic%, and Ca and P are not included.

[Comparative Example 3]
8.17 g of calcium hydrogen phosphate, 1.60 g of calcium carbonate, 1.56 g of calcium fluoride (reagent special grade CaF ₂ , manufactured by Wako Pure Chemical Industries, Ltd.), 0.160 g of manganese oxalate, 0.123 g of zirconium oxide, and fluorine A powdery sample was obtained by performing the same operation as in Comparative Example 2 except that 0.084 g of sodium chloride was used. The composition of the obtained sample is
(Ca _0.96 Mn _0.01 Zr _0.01 Na _0.02 ) ₅ (PO ₄ ) ₃ F
When calculated from the composition formula, Zr is 0.10 atomic% of all atoms, Mn is 0.10 atomic%, Ca is 22.9 atomic%, and P is 14.3 atomic%.

[Measurement of fluorescence]
For each of the following samples synthesized in Examples 1 and 2 and Comparative Examples 1 to 3, the fluorescence spectrum when excited with 147 nm light was measured using a vacuum ultraviolet absorption / fluorescence measuring device manufactured by Spectrometer Co., Ltd. did.
Example 1: (Ca _0.93 Mn _0.07 ) Zr (PO ₄ ) ₂
Example 2: (Ca _0.973 Mn _0.027 ) Zr (PO ₄ ) ₂
Comparative Example 1: (Ca _0.9 Mn _0.04 Zr _0.02 Na _0.04 ) Al ₂ Si ₂ O ₈
Comparative Example 2: (Y _0.8 Mn _0.1 Zr _0.1 ) Al ₃ (BO ₃ ) ₄
Comparative Example 3: (Ca _0.96 Mn _0.01 Zr _0.01 Na _0.02 ) ₅ (PO ₄ ) ₃ F

  FIG. 1 shows an emission spectrum chart when the samples obtained in Examples 1 and 2 and Comparative Examples 1 to 3 are excited with light of 147 nm. The vertical axis is shown so as to be proportional to the actual light emission intensity (energy). Numbers 1 and 2 in the figure correspond to Examples 1 and 2, and numbers 3 to 5 correspond to Comparative Examples 1 to 3, respectively. Compared with Comparative Examples 1 and 2, which are not phosphates, and Comparative Example 3 containing Ca and P but having a low Zr content, the light emission of the examples is clearly stronger.

It is a chart of the fluorescence-emission spectrum when the sample of Examples 1, 2 and Comparative Examples 1-3 is excited with 147 nm light.

Claims (3)

C aZr (PO _{4) 2} to obtain the addition-solid solution M n, the total atoms, Z r 1 atomic% to 15 atomic% or less, Mn of 0.01 atomic% to 5 atomic% or less, Alkaline earth metal element is contained in an amount of 3 atomic% to 35 atomic%, and P is contained in a ratio of 5 atomic% to 20 atomic%, respectively, and from green of 500 to 600 nm by excitation with vacuum ultraviolet light of 130 to 220 nm. Phosphate characterized by emitting fluorescence in the orange region. The phosphate according to claim 1, which is (Ca _0.93 Mn _0.07 ) Zr (PO ₄ ) ₂ . The phosphate according to claim 1, which is (Ca _0.973 Mn _0.027 ) Zr (PO ₄ ) ₂ .

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