JP2011074169A - Phosphor and fluorescent lamp using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a phosphor with little degradation in a baking process when a fluorescent lamp is produced, and the fluorescent lamp using the phosphor. <P>SOLUTION: The phosphor, on the particle surface of which 0.1-21 wt.% of calcium barium borate, on the basis of the amount of phosphor, represented by following formula is coated, has little luminance reduction and little chromaticity change in the baking process when the fluorescent lamp is produced. The formula is (1-m)CaO-mBaO-nB<SB>2</SB>O<SB>3</SB>, wherein 0.2≤m≤0.85, 0.6≤n≤3. Furthermore, the phosphor has large adhesive strength between the phosphor and a glass tube so that especially the phosphor shows larger effect in a circular fluorescent lamp, etc. which is heated at higher temperature than the baking temperature when the fluorescent lamp is produced. Moreover, by using the phosphor, fluorescence is obtained which has high lamp luminous flux and a high luminous flux maintenance factor, and has little chromaticity change. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a phosphor and a fluorescent lamp using the same, and more particularly to a phosphor with little deterioration in a baking process when manufacturing the fluorescent lamp and a fluorescent lamp using the same.

  In general, a fluorescent lamp has a structure in which electrodes are attached to both ends, and a phosphor is applied to the inner surface of a glass tube that is kept airtight. The airtight space is mixed with rare gas such as argon and a small amount of mercury after the air inside is exhausted. When discharge is started between both electrodes, electric energy is converted into ultraviolet radiation in the discharge space in the tube, and this ultraviolet radiation excites the phosphor on the tube wall and emits light. For such fluorescent lamps, a three-wavelength phosphor has been conventionally used. As a blue light-emitting phosphor, europium-activated alkaline earth metal aluminate phosphor (BAM phosphor) and europium-activated alkaline earth metal are used. Europium and manganese-activated alkaline earth metal aluminate phosphors (BAM: Mn phosphors) are used as chloroapatite phosphors (SCA phosphors) and blue-green to green-emitting phosphors. However, these divalent europium activated phosphors are phosphors fired in a reducing atmosphere, and the activator is partially oxidized in the baking process for volatilizing the organic binder during the production of the fluorescent lamp, resulting in a reduction in luminance. There was a problem of chromaticity change.

  As fluorescent lamps, there are circular and polygonal annular fluorescent lamps in addition to straight tube fluorescent lamps, which are used for various lighting applications. In the case of an annular fluorescent lamp, a phosphor layer is formed on the inner surface of a straight tubular glass tube, and then the glass tube is heated to a softening temperature (700 to 900 ° C.) to be formed into an annular shape. There is a problem that the brightness is lowered and the chromaticity change is further increased.

  In order to solve the problem of lowering the brightness in the baking process, Japanese Patent Application Laid-Open No. 8-143863, etc. discloses europium-activated alkaline earth metal aluminate phosphors or europium and manganese-activated alkalis to which rare earth elements such as Sm are added. Although earth metal aluminate phosphors are disclosed, none of them are sufficient and improvements have been demanded.

JP-A-8-143863

  The present invention has been made to solve the above problems. An object of the present invention is to provide a phosphor with little deterioration in a baking process at the time of manufacturing a fluorescent lamp and a fluorescent lamp using the same.

  As a result of intensive investigations to achieve the above object, the present inventor has found that a phosphor having a specific calcium borate / barium coated on the phosphor surface has a decrease in luminance or a change in chromaticity during the baking process when the fluorescent lamp is manufactured. We found that there was little, and came to complete this invention.

(1) The phosphor of the present invention is characterized in that the phosphor particle surface is coated with 0.1 to 21% by weight of calcium borate and barium represented by the following formula with respect to the phosphor.
(1-m) CaO · mBaO · nB ₂ O ₃
(However, 0.2 ≦ m ≦ 0.85, 0.6 ≦ n ≦ 3)

(2) The phosphor of the present invention is the phosphor according to (1), wherein the phosphor is a europium-activated alkaline earth metal aluminate phosphor, europium and manganese-activated alkaline earth metal aluminate It is a salt phosphor or a europium activated alkaline earth metal chloroapatite phosphor.

(3) The phosphor of the present invention is the phosphor according to (2), wherein the phosphor is BaMgAl ₁₀ O ₁₇ : Eu, BaMgAl ₁₀ O ₁₇ : Eu, Mn, (Sr, Ca, Ba) _10. It is (PO ₄ ) ₆ Cl ₂ : Eu.

(4) A fluorescent lamp of the present invention includes a light-transmitting airtight container, a phosphor layer formed in the light-transmitting airtight container, a discharge medium sealed in the light-transmitting airtight container, and an electrode. In the fluorescent lamp, the phosphor layer includes the phosphor described in (1) to (3).

  The phosphor of the present invention has a low luminance decrease and chromaticity change in the baking process at the time of manufacturing the fluorescent lamp, and further has a large adhesive force between the phosphor and the glass tube. In particular, the effect is large in an annular fluorescent lamp heated at a high temperature. Furthermore, by using the phosphor of the present invention, a fluorescent lamp having a high lamp luminous flux, a high luminous flux maintenance factor and little chromaticity change can be obtained.

It is a figure which shows the relationship between the baking luminance maintenance factor of the SCA fluorescent substance of this invention, and m value. It is a figure which shows the relationship between the baking luminance maintenance factor of the SCA fluorescent substance of this invention, and n value. It is a figure which shows the relationship between the baking luminance maintenance factor of the SCA fluorescent substance of this invention, and the coating amount. It is a figure which shows the relationship between the brightness | luminance after baking and the coating amount of the SCA fluorescent substance of this invention. It is a figure which shows the relationship between the baking brightness maintenance factor and baking temperature of the SCA fluorescent substance of this invention. It is a figure which shows the relationship between chromaticity y value of the SCA fluorescent substance of this invention, and baking temperature. It is a figure which shows the relationship between the baking brightness maintenance factor and baking temperature of the BAM fluorescent substance of this invention. It is a figure which shows the relationship between chromaticity y value of the BAM fluorescent substance of this invention, and baking temperature. It is a figure which shows the relationship between the baking brightness maintenance factor of the BAM: Mn fluorescent substance of this invention, and baking temperature. It is a figure which shows the relationship between chromaticity y value of the BAM: Mn fluorescent substance of this invention, and baking temperature. It is a figure which shows the relationship between the adhesive force of the SCA fluorescent substance of this invention, and baking temperature. It is a figure which shows the relationship between the adhesive force of BAM fluorescent substance of this invention, and baking temperature. It is a figure which shows the relationship between the adhesive force of BAM: Mn fluorescent substance of this invention, and baking temperature.

  Hereinafter, a phosphor according to the present invention and a fluorescent lamp using the phosphor will be described using embodiments and examples. However, the present invention is not limited to these embodiments and examples.

Here, the manufacturing method of the fluorescent substance which concerns on one embodiment of this invention is demonstrated. First, a europium-activated alkaline earth metal chloroapatite phosphor (SCA phosphor) is prepared according to a usual method. Next, this phosphor is dispersed in pure water to obtain a phosphor suspension. An aqueous solution of a boron compound (a water-soluble borate such as ammonium borate, sodium borate, or potassium borate is preferable as the boron compound) is added to the phosphor suspension, and then an aqueous solution of a calcium compound (as a calcium compound). Add a water-soluble chloride or nitrate, such as calcium chloride or calcium nitrate, and an aqueous solution of barium compound (water-soluble chloride or nitrate as barium compound, such as barium chloride or barium nitrate), and react. Calcium and borate borate is deposited on the phosphor surface. Thereafter, the treated phosphor and the dispersion medium are separated and dried to obtain the phosphor of the present invention coated with calcium and barium borate represented by the following formula.
(1-m) CaO · mBaO · nB ₂ O ₃
(However, 0.2 ≦ m ≦ 0.85, 0.6 ≦ n ≦ 3)

  The particle size of calcium borate / barium coated on the phosphor surface is preferably 0.5 μm or less, more preferably 0.1 μm or less. When the particle size is larger than 0.5 μm, the phosphor surface is not uniformly coated, and the effect of the present invention is reduced. Here, the particle size is measured by an electron micrograph of the phosphor.

  The composition of calcium borate and barium precipitated on the phosphor surface is prepared by changing the amount of raw material added. The particle size of calcium borate / barium is prepared by changing the concentration, temperature, and pH of the reaction solution.

  Calcium / borate borate on the phosphor surface is coated in a film form when the coating amount is less than 1.2% by weight, but is coated in a film form and granular form at 1.2% by weight or more.

  Next, a method for manufacturing a fluorescent lamp according to an embodiment of the present invention will be described. First, the phosphor of the present invention and a binder such as calcium pyrophosphate and calcium barium borate (CBB) are added to a nitrocellulose / butyl acetate solution, and these are mixed and suspended to prepare a phosphor-coated suspension. . The obtained phosphor coating suspension is poured into the inner surface of the glass tube, and then dried by passing warm air through the glass tube, followed by baking at 600 to 700 ° C. to form a phosphor layer. After mounting the electrode, it is heated to 700 to 900 ° C. and formed into an annular shape, and the annular fluorescent lamp of the present invention is obtained through a process such as exhaust.

  The characteristics of the phosphor of the present invention will be described with reference to the drawings. FIG. 1 shows the SCA phosphor obtained by changing the amount of Ca and Ba of the raw material in Example 1, and the baking luminance maintenance rate when baking at 700 ° C. for 30 minutes and calcium barium borate adhering to the phosphor. Shows the relationship with the m value. From this figure, the baking luminance maintenance ratio is as high as 80% or more in the range of 0.2 ≦ m ≦ 0.85, 85% or more in the range of 0.3 ≦ m ≦ 0.8, and 0.4 ≦ m ≦ 0. It can be seen that 90% or higher in the range of 0.7 and 93% or higher in the range of 0.5 ≦ m ≦ 0.66.

  FIG. 2 shows the SCA phosphor obtained by changing the amount of B in the raw material in Example 1, the baking luminance maintenance rate when baking at 700 ° C. for 30 minutes and the n value of calcium borate and barium adhering to the phosphor. Shows the relationship. From this figure, the baking luminance maintenance rate is as high as 80% or more in the range of 0.6 ≦ n ≦ 3, 85% or more in the range of 0.9 ≦ n ≦ 2.5, and 1.2 ≦ n ≦ 2. It can be seen that it is 90% or more, and it is further increased to 93% or more in the range of 1.4 ≦ n ≦ 1.7.

  FIG. 3 shows the baking luminance maintenance ratio when baking is performed at 700 ° C. for 30 minutes for the SCA phosphor obtained by changing the coating amount of calcium borate and barium by changing the addition amount of the raw material in Example 1. The relationship with the coating amount of calcium borate and barium adhering to the phosphor is shown. From this figure, the baking luminance maintenance rate is as high as 80% or more when the coating amount of calcium borate / barium is 0.1% by weight or more, higher as 85% or more when 0.3% by weight or more, and 0.7% by weight. From the above, it can be seen that it is higher than 90%.

  FIG. 4 shows an SCA phosphor obtained by changing the coating amount of calcium borate and barium by changing the addition amount of the raw material in Example 1, respectively at 700 ° C. (solid line) and 650 ° C. (dotted line). The relationship between the brightness | luminance after baking when baking for minutes and the coating amount of calcium borate barium adhering to fluorescent substance is shown. Here, the luminance after baking is emission luminance when excited by ultraviolet light having a wavelength of 253.7 nm. In the case of 700 ° C. (solid line) in FIG. 4, the phosphor before coating with calcium borate / barium is obtained. This is the relative luminance when the luminance after baking at 700 ° C. is 100%. In the case of 650 ° C. (dotted line), the luminance after baking the phosphor before coating with calcium borate / barium at 650 ° C. Is the relative luminance when 100 is 100%. From this figure, in the case of 700 ° C. (solid line), the luminance after baking is as high as 101% or more in the range of 0.1 to 21% by weight of calcium borate / barium coating, and 0.3 to 16% by weight. It can be seen that the range is higher than 110%. Moreover, in the case of 650 degreeC (dotted line), it turns out that the brightness | luminance after baking is as high as 101% or more in the range whose coverage of calcium borate barium is 0.1 to 9 weight%.

Accordingly, from FIGS. 1 to 4, calcium borate represented by (1-m) CaO · mBaO · nB ₂ O ₃ (where 0.2 ≦ m ≦ 0.85, 0.6 ≦ n ≦ 3) It can be seen that a phosphor having a high baking luminance maintenance ratio and high luminance after baking can be obtained by coating barium in the range of 0.1 to 21% by weight.

  FIG. 5 shows a case where the SCA phosphor of Example 1 coated with calcium and barium borate (solid line) and the SCA phosphor of Comparative Example 1 before coating (dotted line) were baked for 30 minutes at different baking temperatures. The relationship between the baking luminance maintenance rate and the baking temperature is shown. From this figure, when the baking temperature exceeds 400 ° C., the difference in baking luminance maintenance rate between Example 1 and Comparative Example 1 gradually increases, and further, the difference in baking luminance maintenance rate increases from 600 ° C. to 800 ° C. You can see it grows.

  FIG. 6 shows that the SCA phosphor of Example 1 coated with calcium and barium borate (solid line) and the SCA phosphor of Comparative Example 1 before coating (dotted line) were baked for 30 minutes at different baking temperatures. The relationship between the chromaticity y value (CIE color system) of the phosphor and the baking temperature is shown. From this figure, when the baking temperature exceeds 400 ° C., the chromaticity y value of the phosphor after baking gradually increases between Example 1 and Comparative Example 1, and further increases from 600 ° C. to 800 ° C. It can be seen that the difference increases.

  FIG. 7 shows that the BAM phosphor of Example 8 coated with calcium and barium borate (solid line) and the BAM phosphor of Comparative Example 2 before coating (dotted line) were baked for 30 minutes at different baking temperatures. The relationship between the baking luminance maintenance rate and the baking temperature is shown. From this figure, it can be seen that the difference in baking luminance maintenance ratio between Example 8 and Comparative Example 2 increases from around 600 ° C., and the difference in baking luminance maintenance ratio increases as the temperature rises.

  FIG. 8 shows that the BAM phosphor of Example 8 coated with calcium and barium borate (solid line) and the BAM phosphor of Comparative Example 2 before coating (dotted line) were baked for 30 minutes at different baking temperatures. The relationship between the chromaticity y value (CIE color system) of the phosphor and the baking temperature is shown. From this figure, the chromaticity y value of the phosphor after baking from around 400 ° C. has a large difference between Example 8 and Comparative Example 2, and the difference becomes even larger when the temperature becomes high from 600 ° C. to 800 ° C. I understand that

  FIG. 9 shows that the BAM: Mn phosphor of Example 9 coated with calcium and barium borate (solid line) and the BAM: Mn phosphor of Comparative Example 3 before coating (dotted line) were changed to 30 by changing the baking temperature. The relationship between the baking brightness | maintenance rate and baking temperature when baking for minutes is shown. From this figure, it can be seen that the difference in baking luminance maintenance ratio between Example 9 and Comparative Example 3 increases from about 400 ° C. in the baking temperature, and the difference in baking luminance maintenance ratio further increases at high temperatures from 600 ° C. to 800 ° C.

  FIG. 10 shows that the BAM: Mn phosphor of Example 9 coated with calcium and barium borate (solid line) and the BAM: Mn phosphor of Comparative Example 3 before coating (dotted line) were changed to 30 by changing the baking temperature. The relationship between the chromaticity y value (CIE color system) of the phosphor when baking for a minute and the baking temperature is shown. From this figure, the chromaticity y value of the phosphor after baking from around 400 ° C. has a large difference between Example 9 and Comparative Example 3, and the difference is even larger at a high temperature of 600 ° C. to 800 ° C. I understand.

  Therefore, as shown in FIGS. 5 to 10, by coating the calcium borate / barium of the present invention, the higher the baking temperature from 600 ° C. to 800 ° C., the greater the effect on the baking luminance maintenance ratio and chromaticity change. I understand.

  FIG. 11 shows that the SCA phosphor of Example 1 coated with calcium and barium borate (solid line) and the SCA phosphor of Comparative Example 1 before coating (dotted line) were baked for 15 minutes at different baking temperatures. The relationship between adhesive strength and baking temperature is shown. From this figure, it can be seen that the difference between Example 1 and Comparative Example 1 increases as the baking temperature increases from 600 ° C. to 700 ° C.

  FIG. 12 shows a case where the BAM phosphor of Example 8 coated with calcium and barium borate (solid line) and the BAM phosphor of Comparative Example 2 before coating (dotted line) were baked for 15 minutes at different baking temperatures. The relationship between adhesive strength and baking temperature is shown. From this figure, it can be seen that the difference between Example 8 and Comparative Example 2 increases as the baking temperature increases from 600 ° C. to 700 ° C.

  FIG. 13 shows the BAM: Mn phosphor of Example 9 coated with calcium and barium borate (solid line) and the BAM: Mn phosphor of the comparative example 3 before coating (dotted line) with varying baking temperatures of 15 respectively. The relationship between the adhesive force when baking for a minute and baking temperature is shown. From this figure, it can be seen that the difference between Example 9 and Comparative Example 3 increases as the baking temperature increases from 600 ° C. to 700 ° C.

Therefore, it can be seen from FIGS. 11 to 13 that the effect of adhesive strength increases as the baking temperature increases from 600 ° C. to 700 ° C. by coating the calcium borate barium of the present invention.

In addition, from the above results, the higher the baking temperature, the greater the effect on the baking luminance maintenance rate and chromaticity change, and the greater the effect of the adhesive strength, so the heating temperature is higher than the baking temperature at the time of manufacturing the fluorescent lamp. It can be seen that the effect is great in a ring fluorescent lamp.

  The baking luminance maintenance rate is measured as follows. 1) Pack 5 g of the phosphor in a magnetic crucible and use an electric furnace to bake at a predetermined temperature for 30 minutes. 2) The phosphor before and after baking is excited with ultraviolet light having a wavelength of 253.7 nm, and the emission luminance is measured. 3) [(Luminance after baking / Luminance before baking) × 100%] is obtained and set as a baking luminance maintenance ratio.

  The chromaticity y value after baking is measured as follows. 1) Pack 5 g of the phosphor in a magnetic crucible and use an electric furnace to bake at a predetermined temperature for 30 minutes. 2) The phosphor after baking is excited with ultraviolet rays having a wavelength of 253.7 nm, and the chromaticity y value (the chromaticity coordinate value of the CIE color system) is measured.

  The adhesive strength after baking is measured as follows. 1) 27 g of phosphor is added to 30 g of 1.2% nitrocellulose / butyl acetate solution to prepare a phosphor-coated suspension. 2) A phosphor coating suspension is hung on a glass piece and placed on a spin coater. 3) Rotate the spin coater to apply the phosphor to the glass piece. 4) Put a glass piece coated with a phosphor in an electric furnace and bake at a predetermined temperature for 15 minutes. 5) Water is applied to the glass piece after baking, and the water pressure when the phosphor film is peeled off is measured to obtain the adhesive strength.

  Examples of the present invention will be described below, but it goes without saying that the present invention is not limited to specific examples.

[Example 1]
100 g of divalent europium-activated strontium chloroapatite phosphor (SCA phosphor) represented by the general formula (Sr _0.99 Eu _0.01 ) ₁₀ (PO ₄ ) ₆ Cl ₂ is suspended in 150 ml of pure water. To do. To this phosphor suspension, 8.0 ml of 33.8 wt% (NH ₄ ) ₃ BO ₃ aqueous solution is added and stirred. Next, 2.2 ml of 26.9 wt% CaCl ₂ aqueous solution and 37.3 ml of 24.1 wt% BaCl ₂ aqueous solution are added to precipitate calcium borate and barium on the phosphor surface. After that, solid-liquid separation is performed with Nutsche, and the solid content is dried at 110 ° C. for 15 hours, and calcium borate / barium represented by 0.34CaO · 0.66BaO · 1.4B ₂ O ₃ is 2.1% by weight. A coated phosphor of the present invention is obtained.

[Example 2]
Except adding 4.0 ml of 26.9 wt% CaCl ₂ aqueous solution and 3.6 ml of 24.1 wt% BaCl ₂ aqueous solution, it is expressed as 0.68CaO · 0.32BaO · 1.4B ₂ O ₃ in the same manner as in Example 1. The phosphor of the present invention coated with 2.1% by weight of calcium barium borate is obtained.

[Example 3]
It is represented by 0.50CaO · 0.50BaO · 1.4B ₂ O ₃ in the same manner as in Example 1 except that 2.8 ml of 26.9 wt% CaCl ₂ aqueous solution and 5.9 ml of 24.1 wt% BaCl ₂ aqueous solution were added. The phosphor of the present invention coated with 2.1% by weight of calcium barium borate is obtained.

[Example 4]
Calcium borate represented by 0.34CaO · 0.66BaO · 1.7B ₂ O ₃ in the same manner as in Example 1 except that 9.7 ml of 33.8 wt% (NH ₄ ) ₃ BO ₃ aqueous solution was added. The phosphor of the present invention coated with 2.1% by weight of barium is obtained.

[Example 5]
Calcium borate represented by 0.34CaO · 0.66BaO · 2.0B ₂ O ₃ in the same manner as in Example 1 except that 11.4 ml of 33.8 wt% (NH ₄ ) ₃ BO ₃ aqueous solution was added. The phosphor of the present invention coated with 2.1% by weight of barium is obtained.

[Example 6]
Example 1 except that 2.7 ml of 33.8 wt% (NH ₄ ) ₃ BO ₃ aqueous solution was added and 0.7 ml of 26.9 wt% CaCl ₂ aqueous solution and 12.4 ml of 24.1 wt% BaCl ₂ aqueous solution were further added. The phosphor of the present invention coated with 0.7% by weight of calcium borate / barium represented by 0.34CaO.0.66BaO.1.4B ₂ O ₃ is obtained in the same manner as described above.

[Example 7]
Example 1 except that 42.3 ml of 33.8 wt% (NH ₄ ) ₃ BO ₃ aqueous solution was added, and further 11.6 ml of 26.9 wt% CaCl ₂ aqueous solution and 197.2 ml of 24.1 wt% BaCl ₂ aqueous solution were added. In the same manner as above, the phosphor of the present invention coated with 11.1% by weight of calcium borate / barium represented by 0.34CaO.0.66BaO.1.4B ₂ O ₃ is obtained.

[Example 8]
Suspend 100 g of divalent europium activated alkaline earth metal aluminate phosphor (BAM phosphor) represented by the general formula (Ba _0.9 Eu _0.1 ) MgAl ₁₀ O ₁₇ in 150 ml of pure water. To do. To this phosphor suspension, 8.0 ml of 33.8 wt% (NH ₄ ) ₃ BO ₃ aqueous solution is added and stirred. Next, 2.2 ml of 26.9 wt% CaCl ₂ aqueous solution and 37.3 ml of 24.1 wt% BaCl ₂ aqueous solution are added to precipitate calcium borate and barium on the phosphor surface. After that, solid-liquid separation is performed with Nutsche, and the solid content is dried at 110 ° C. for 15 hours, and calcium borate / barium represented by 0.34CaO · 0.66BaO · 1.4B ₂ O ₃ is 2.1% by weight. A coated phosphor of the present invention is obtained.

[Example 9]
Divalent europium and divalent manganese-activated alkaline earth metal aluminate fluorescent compounds represented by the general formula (Ba _0.9 Eu _0.1 ) (Mg _0.8 Mn _0.2 ) Al ₁₀ O ₁₇ 100 g of the body (BAM: Mn phosphor) is suspended in 150 ml of pure water. To this phosphor suspension, 8.0 ml of 33.8 wt% (NH ₄ ) ₃ BO ₃ aqueous solution is added and stirred. Next, 2.2 ml of 26.9 wt% CaCl ₂ aqueous solution and 37.3 ml of 24.1 wt% BaCl ₂ aqueous solution are added to precipitate calcium borate and barium on the phosphor surface. After that, solid-liquid separation is performed with Nutsche, and the solid content is dried at 110 ° C. for 15 hours, and calcium borate / barium represented by 0.34CaO · 0.66BaO · 1.4B ₂ O ₃ is 2.1% by weight. A coated phosphor of the present invention is obtained.

[Comparative Example 1]
An SCA phosphor that is not coated with a surface treatment substance (the SCA phosphor before coating in Examples 1 to 7) is prepared.

[Comparative Example 2]
A BAM phosphor not coated with a surface treatment substance (a BAM phosphor before coating in Example 8) is prepared.

[Comparative Example 3]
A BAM: Mn phosphor that is not coated with a surface treatment substance (a BAM: Mn phosphor before coating in Example 9) is prepared.

  For each phosphor obtained in Examples 1 to 9 and Comparative Examples 1 to 3, the composition and coverage of calcium borate and barium on the phosphor surface, and the baking luminance maintenance rate when baked at 700 ° C. for 30 minutes are shown in Table 1. Shown in From this table, it can be seen that the phosphors of Examples 1 to 9 of the present invention have a higher baking luminance maintenance rate than the phosphors of Comparative Examples 1 to 3 which are not coated with calcium borate / barium.

  Next, a monochromatic fluorescent lamp (straight tube, inner diameter: 2 mm, outer diameter: 3 mm) is manufactured using the phosphors obtained in Example 6 and Comparative Example 1. First, 27 g of phosphor, 2.7 g of 15% CBB binder / butyl acetate solution, and 30 g of 1.2% nitrocellulose / butyl acetate solution are mixed to prepare a phosphor coating suspension. The obtained phosphor coating suspension is poured into the inner surface of the glass tube, then dried by passing warm air through it, baked at 650 ° C. for 3 minutes, evacuated, fitted with a filament, and attached with a base. Get a fluorescent lamp.

  Table 2 shows the results of measuring the initial luminous flux, luminous flux maintenance factor, and chromaticity change amount of the fluorescent lamp thus obtained using an integrating sphere. Here, the lamp luminous flux is an initial luminous flux at the time of manufacturing the fluorescent lamp, and indicates a relative value (relative luminous flux) when the initial luminous flux of the fluorescent lamp using the phosphor of Comparative Example 1 is 100%. The luminous flux maintenance factor is a value obtained by calculating [(lamp luminous flux after 100 hours of lighting / initial luminous flux) × 100%]. The amount of change in chromaticity is obtained by measuring the emission color at the time of producing the fluorescent lamp and after lighting for 100 hours, and obtaining the change amount Δx of chromaticity x and the change amount Δy of chromaticity y. From this table, the fluorescent lamp using the phosphor of Example 6 of the present invention has a lamp luminous flux and a luminous flux maintenance as compared with the fluorescent lamp using the phosphor of Comparative Example 1 that is not coated with calcium borate and barium. It can be seen that the rate is high and the amount of chromaticity change is small.

  Therefore, from the above results, by coating calcium borate and barium borate on the SCA phosphor, a phosphor having high baking luminance maintenance rate and adhesive strength and less chromaticity change can be obtained, and this phosphor is used for a fluorescent lamp. Thus, it can be seen that a fluorescent lamp with a high lamp luminous flux and a luminous flux maintenance factor and a small chromaticity change can be obtained. A similar effect can be obtained when a BAM phosphor or a BAM: Mn phosphor is used.

  As described above, the phosphor of the present invention has a low luminance decrease and chromaticity change in the baking process at the time of manufacturing the fluorescent lamp, and further has a large adhesive force between the phosphor and the glass tube. The effect is great in a ring-shaped fluorescent lamp heated at a temperature higher than the baking temperature at the time of manufacturing the lamp. By using the phosphor of the present invention, it is possible to provide a fluorescent lamp having a high lamp luminous flux and a luminous flux maintenance factor and a small chromaticity change.

Claims (4)

1. A phosphor characterized in that the phosphor particle surface is coated with 0.1 to 21% by weight of calcium borate / barium represented by the following formula with respect to the phosphor.
(1-m) CaO · mBaO · nB ₂ O ₃
(However, 0.2 ≦ m ≦ 0.85, 0.6 ≦ n ≦ 3)   The phosphor is a europium activated alkaline earth metal aluminate phosphor, a europium and manganese activated alkaline earth metal aluminate phosphor, or a europium activated alkaline earth metal chloroapatite phosphor. The phosphor according to claim 1. The phosphor _{BaMgAl 10 O 17: Eu, BaMgAl} 10 O 17: Eu, Mn, (Sr, Ca, Ba) 10 (PO 4) 6 Cl 2: according to claim 2, characterized in that the Eu Phosphor.   In a fluorescent lamp comprising a translucent airtight container, a phosphor layer formed in the translucent airtight container, a discharge medium enclosed in the translucent airtight container, and an electrode, the phosphor layer is A fluorescent lamp comprising the phosphor according to claim 1.

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