JP2006274088A - Uv excited luminescent phosphor, mixed phosphor having the same, and fluorescent lamp and cold cathode fluorescent lamp using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a YVO phosphor used for a fluorescent lamp improved in the lamp luminous flux maintenance factor and the like. <P>SOLUTION: The phosphor is the one wherein an antimony oxide is coated on a phosphor (Y(V, P)O<SB>4</SB>:Eu) that is an Eu-activated rare earth vanadate or one wherein part or the whole of the rare earth vanadate is substituted by a rare earth phosphate. The fluorescent lamp having it has an improved lamp luminous flux maintenance factor and in addition shows improvement in the displacement of chromaticity. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is used for a cold cathode fluorescent lamp, a fluorescent lamp for general illumination, an Hg-enclosed flat lamp, a high-load fluorescent lamp, etc., and a fluorescent lamp and a backlight light source for a liquid crystal display device. The present invention relates to a cold cathode fluorescent lamp and a flat lamp, and more particularly, to provide a phosphor having a good emission energy maintenance rate in a device, a white light source having a small color change, and a color liquid crystal display device using the same. .

As a red phosphor used for a fluorescent lamp or the like, a Y (P, V) O ₄ phosphor is used. In addition to fluorescent lamps, phosphors have various uses such as PDP. Depending on each application and the type of phosphor, phosphor powders and films may have various surface treatments such as coating. A covering film is formed.

JP-A-10-330746 Japanese Patent Laid-Open No. 53-119793 Japanese Patent Application Laid-Open No. 01-176652 Japanese Patent Laid-Open No. 55-131083

  In order to improve the characteristics of phosphors used in UV-excited light-emitting devices, particularly durability (for example, luminous flux maintenance factor) in the environment where the phosphors are used (for example, in a discharge tube), it is proposed to form various coating films Has been implemented.

  As for the coating film of antimony, reference 1 has an aluminate phosphor coated with an oxide of antimony, reference 3 has tin-activated alkaline earth normal phosphate phosphor or tin-activated alkaline earth pyrophosphate. A mixture of a salt phosphor and antimony trioxide is disclosed.

However, depending on the type of phosphor, especially the chemical classification of the matrix (phosphate, aluminate, etc.), crystallographic classification (crystal structure), the composition of the activator and the matrix, constituent elements, etc. The deterioration mechanism is different. In addition, since deterioration factors differ depending on the use of the phosphor, particularly the usage environment of the phosphor, for example, in Reference 4, in the phosphor for electron beam excitation, Y ₂ O ₂ S: Eu, Y ₂ O ₃ : Eu , YVO ₄ : Eu or the like is coated with tin oxide containing antimony as a conductive film, thereby increasing the conductivity and slowing down the excitation electron beam. However, the present invention is a different use environment, and its function also imparts conductivity.
The Y (P, V) O ₄ : Eu phosphor is used as a red phosphor for a high-pressure mercury lamp, but when used in a fluorescent lamp for general illumination, a cold cathode used as a color liquid crystal backlight illumination. When used in a fluorescent lamp, the luminous flux maintenance factor becomes a problem.

This invention is made | formed as a result of earnestly examining in view of the said subject, and can solve a subject by following (1)-(11).
(1) An antimony oxide is coated on the surface of a phosphor particle activated by Eu, or a phosphor particle surface in which a part or all of the rare earth vanadate is substituted with a rare earth phosphate. Phosphor. With this configuration, a rare earth vanadate phosphor, and a phosphor partially or entirely substituted with a rare earth phosphate, preferably a rare earth vanadate phosphor and a phosphor partially substituted with the rare earth phosphate, Therefore, when used in a discharge space, such as an ultraviolet-excited fluorescent lamp, it is possible to prevent phosphor deterioration and to obtain a lamp having a good luminous flux maintenance factor. Specifically, as a cause of deterioration of the fluorescent lamp (decrease in the initial luminous flux and reduction in the luminous flux maintenance factor), it is conceivable that the phosphor and the phosphor film thereof are degraded by ion bombardment, mercury adsorption, etc. It is considered that this is improved by the oxide film, and as a result, a fluorescent lamp (for general illumination and liquid crystal backlight) having an excellent luminous flux maintenance factor can be obtained.
(2) The phosphor according to (1), wherein the phosphor is represented by a general formula of Y (V, P) O ₄ : Eu.
(3) The ultraviolet-excited luminescent material according to (2), wherein the general formula is Y (V _{1 -x} , P _x ) O ₄ : Eu, and x is 0 ≦ x <1. Y (V _1−x , P _x ) O ₄ : Eu having sufficient luminance and lamp / white light source suitable for use as an ultraviolet-excited red light-emitting phosphor, where x is 0 ≦ x <1, The effect of improving the luminance and lamp luminous flux maintenance factor due to the coating of the antimony oxide is considered to be because the phosphor deterioration preventing function functions suitably.
(4) The phosphor according to any one of (1) to (3), wherein the oxide of antimony is in a range of more than 0 parts by weight and 1 part by weight or less as Sb with respect to 100 parts by weight of the phosphor. In the rare earth vanadate / phosphate phosphor, the amount of light flux is 100% by weight of the phosphor, and has Sb (converted amount of antimony oxide) in an amount of 1 part by weight or less. There is an effect of improving the maintenance rate.
(5) The antimony oxide is the phosphor according to (4), which is in the range of more than 0 parts by weight and 0.5 parts by weight or less as Sb with respect to 100 parts by weight of the phosphor. By having an antimony oxide in the range, a phosphor and a fluorescent lamp having an excellent luminous flux maintenance factor can be obtained.
More preferably, it has an antimony oxide in the range of 0.01 parts by weight to 0.3 parts by weight with respect to 100 parts by weight of the phosphor, compared with the case of having an antimony oxide coating outside the range. The luminous flux maintenance factor is excellent, the luminous flux is high, and the luminous flux ratio is 99% or more compared to the case without coating.
More preferably, they are 0.05 weight part or more and 0.2 weight part or less with respect to 100 weight part of fluorescent substance.
(6) A phosphor mixed with a white light source, wherein the phosphor described in (1) to (5) is a red light emitting phosphor, and further includes blue and green light emitting phosphors.
(7) The white phosphor according to (6), wherein the blue phosphor includes a BaMgAl ₁₀ O ₁₉ : Eu phosphor. SCA {(Sr, Ca, Ba) ₅ (PO ₄ ) ₃ Cl: Eu} phosphor, (Sr, Ca, Ba) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu phosphor, and the like can also be used.
(8) The green phosphor is any one of BaMgAl ₁₀ O ₁₇ : Eu, Mn phosphor, (Ce, Tb) (Mg, Mn) Al ₁₁ O ₁₉ phosphor, Zn ₂ SiO ₄ : Mn phosphor A mixed phosphor of a white light source according to the above (6) or (7).
(9) A cold cathode fluorescent lamp provided with the mixed phosphor or the phosphor of each emission color according to the above (6) to (8).
(10) A fluorescent lamp having the ultraviolet-excited luminescent material described in (1) to (5) above.
(11) A fluorescent lamp having the mixed phosphor according to the above (6) to (8).

  At the time of lamp formation, the initial luminous flux is almost the same as or slightly lower than that of the prior art in which no coating film made of antimony oxide is used, and the YVO phosphor is coated with antimony oxide, thereby maintaining good luminous flux. Thus, even if the initial luminous flux is lower than the conventional one, the luminous flux after 100 hours to 500 hours is reversed, and the luminous flux of the antimony oxide coating is increased. In addition, in any state of the powder and the phosphor layer (phosphor film), and also in other phosphors, for example, a mixed phosphor layer (phosphor film) with green and blue-emitting phosphors, An excellent luminous flux maintenance factor can be realized without impairing the characteristics. Thus, it can be used for various types of backlight illumination for general illumination fluorescent lamps and liquid crystal display devices.

The coated ultraviolet-excited luminescent phosphor, mixed phosphor thereof, and fluorescent lamp using the same will be described. The ultraviolet-excited luminescent phosphor of the present invention (a rare earth vanadate activated with Eu and a part or all thereof is replaced with a rare earth phosphate) is a YVO phosphor, a YVO ₄ : Eu phosphor, It is described as Y (P, V) O ₄ phosphor.

<Coating film formation / coating method>
As a coating method, phosphor particles and antimony oxide are mixed by dry mixing or wet mixing to coat the surface of the phosphor particles with the antimony oxide. Most simply, an appropriate amount of antimony oxide fine particles are mixed with the phosphor in a dry process to obtain a phosphor in which the surface of the phosphor particles is coated with antimony oxide. In order to obtain a uniform coating, the phosphor and antimony oxide are suspended in a solvent such as water, mixed thoroughly with a ball mill or the like, and then the suspension is separated and dried to make the antimony oxide more uniform. Can be coated on the surface of the phosphor particles. In these methods, antimony oxide is directly mixed with the phosphor. As wet mixing, for example, as shown in Example 2 or the like, antimony oxide particles may be suspended in a phosphor binder resin.

  In order to obtain a more uniform coating of antimony oxide, a method using the following chemical reaction can be applied. For example, a phosphor is suspended in water, a water-soluble acidic antimony salt is added to the suspension, and an aqueous solution of a basic substance is added to the suspension to neutralize the antimony hydroxide. By depositing on the particle surface of the phosphor, solid-liquid separation, and drying at a temperature of 100 ° C. or higher, a phosphor whose particle surface is coated with an antimony oxide can be obtained. As the water-soluble acidic antimony salt, antimony sulfate such as antimony chloride, antimony fluoride and other antimony halides, antimony sulfate, and antimony nitrate can be used. As the basic substance for neutralizing the suspension, ammonia, caustic soda, and the like can be used.

  As a method for forming the coating film, for example, an optically stable film is formed by baking in a baking process after applying a phosphor to a glass tube and removing the binder.

<Baking conditions of coated antimony oxide>
The baking temperature is, for example, 500 ° C. or higher and 650 ° C. or lower. Further, the atmosphere is not particularly limited, and examples thereof include air or a neutral atmosphere of N ₂ or Ar.

<Composition>
The coating of antimony oxide in the present invention may be any of Sb ₂ O ₃ , Sb ₂ O ₄ , and Sb ₂ O ₅ , or a mixture or composite thereof. In addition, a mixture of these oxides from the step of coating or mixed phosphors may contain a trace amount of halogen elements such as chlorine or hydroxides that can be mixed as coating materials for other (luminescent color) phosphors. In addition, the coating effect of the present invention can be obtained even when the phosphor particles are coated with a mixture of, for example, rare earth metal carbonates, specifically carbonate compounds such as lanthanum carbonate and yttrium carbonate. There is no loss.

  As will be described later, the method of forming the coating film, particularly the mixing method (wet / dry method), the coating formation temperature (the baking temperature when forming the phosphor layer of the lamp) and the atmosphere (phosphor binder composition, fluorescence of other emission colors) Depending on the environment in which the body is mixed, Hg (mercury) in the discharge space, sealing gas (inert gas [Ar, Xe]), the film quality is considered to change, and antimony (Sb) has a valence of III. Therefore, it is considered that the oxide film has a complicated structure, for example, a chain structure in which III and IV are mixed and cross-linked with oxygen (O). Even if the Sb amount and the mixing ratio with other phosphors of the emission color (binder, suspension of the mixed phosphor during wet mixing, etc.) are changed, as will be seen in the examples described later, the present invention Therefore, the oxide of the above composition formula and / or the mixture thereof At that time, the structure is considered to change, but the effect of the present invention can still be obtained, so that the structural change is small or the effect is less dependent on the structure. As for the lamp, as shown in the examples described later, since a remarkable improvement in the luminous flux maintenance factor was confirmed, in consideration of ion bombardment and Hg adsorption, which are considered as causes of conventional deterioration, such a gas-filled fluorescent lamp is used. The antimony oxide coating structure of the present invention can be suitably used in a lamp or a fluorescent lamp having Hg, particularly a fluorescent lamp in which both are enclosed. The improvement effect is obtained.

<Dependence of Sb coating amount: Sb coating amount dependency of lamp luminous flux and its maintenance factor>
FIG. 1A plots the relationship between the change in lamp luminous flux with time and the Sb analysis value of antimony oxide for a YVO ₄ : Eu phosphor coated with antimony oxide.

  As shown in FIG. 1, the lamp luminous flux maintenance factor of the phosphor not coated with Sb after lighting for 100 hours is 93%, but the luminous flux maintenance factor of approximately 100% is exhibited by the Sb coating. Furthermore, even after 300 hours and 500 hours have passed, the tendency does not change, and the luminous flux maintenance factor continues to decrease for phosphors without coating, while the phosphors coated with antimony oxide maintain almost the same luminous flux. is doing. Further, the chromaticity point hardly changes with respect to the lighting time, and the chromaticity coordinate tends to be maintained after the initial chromaticity change (0 to 100 hours), and the initial chromaticity coordinate is displaced. In an uncoated phosphor, Δx and Δy tend to decrease, and in a phosphor coated with antimony oxide, Δx and Δy tend to increase.

<Each color phosphor>
Examples of the red light emitting phosphor include Y ₂ O ₃ : Eu phosphor, 3.5 MgO · 0.5 MgF ₂ · GeO ₂ : Mn ⁴⁺ phosphor, and the like. These phosphors are mixed with Y (P, V) O ₄ : Eu of the present invention and used as a mixed phosphor emitting red light.

Green phosphors include LaPO ₄ : Ce, Tb phosphor, (Ce, Tb) (Mg, Mn) Al ₁₁ O ₁₉ ⁺ phosphor, Y ₂ SiO ₅ : Tb, Ce phosphor, Zn ₂ SiO _4: Mn ^{_{phosphor, M II 1-x Eu x}} O · a (Mg 1-y Mn y) O · bAl 2 O 3 phosphor (M ^II is Ba, at least one selected from the group consisting of Sr and Ca A, b, x, and y are real numbers satisfying 0.8 ≦ a ≦ 1.2, 4.5 ≦ b ≦ 5.5, 0.05 ≦ x ≦ 0.3, and 0.02 ≦ y ≦ 0.5.

As the blue light emitting phosphor, BaMgAl ₁₀ O ₁₇ : Eu phosphor, (Sr, Ca, Ba) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu phosphor or (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu phosphor and the like.

[Production of YVO phosphor]
Weigh each desired amount of raw materials of Y ₂ O ₃ , Eu ₂ O ₃ , V ₂ O ₅ (additional H ₃ PO ₄ and (NH ₃ ) ₂ HPO _{4 for} Y (P, V) O ₄ ) Then, put it in a porcelain pot together with water and alumina balls, etc., knead in a ball mill for 15 hours, for example, and then dry and calcinate, for example, at 1250 ° C. for 6 hours. Get. Thereafter, a trivalent europium-activated vanadic acid (phosphoric acid) phosphor is obtained by subjecting it to a dispersion treatment, sieving and washing and drying treatment.

  In each of the following examples, “NP-310-10” (Y (P, V) O phosphor) and “NP-312” (YVO phosphor) manufactured by Nichia Corporation are used.

[Fluorescent lamp production]
The YVO ₄ : Eu phosphor and a predetermined amount of antimony oxide Sb ₂ O ₃ are put in a mixing container and dry mixed. The mixture obtained by the process is suspended in a solvent, here, a phosphor binder resin for coating, and the binder is coated in a glass tube to be a fluorescent lamp, for example, heat treatment conditions of 580 to 600 ° C. for 15 minutes. , And a phosphor layer is formed in the glass tube. At this time, as for the phosphor layer, a vitreous film is observed, the antimony oxide is altered, and it is considered that the phosphor particle surface is coated, and as the amount of the antimony oxide increases. Observed brownish. This is considered to be one of the causes that the luminous flux is reduced as the amount of antimony oxide increases in each of the following examples. Subsequently, Hg and Ar gas are sealed by a normal method, and the tube is sealed with an electrode to produce a red single color FL40SS standard fluorescent lamp (straight tube type).

  Fluorescent lamps in each example described later are manufactured and evaluated by the above method using the phosphors in each example.

[Example 1]
Example 1 YVO phosphor obtained by the above production method (manufactured by Nichia Corporation: NP-312, emission wavelength 620 nm, 253.7 nm for excitation wavelength) (composition [YVO ₄ : Eu]) and antimony oxide Sb ₂ O ₃ is suspended in pure water, and the suspension is separated, dried, and sieved to obtain a powder phosphor mixture. Here, the amount of antimony oxide (Sb ₂ O ₃ ) is 0.2 parts by weight (Sb is 0.167 parts by weight) with respect to 100 parts by weight of the phosphor. Thus, the fluorescent substance mixture obtained by wet mixing and the fluorescent substance of Comparative Example 1 below were measured for the powder brightness, and they were of substantially the same luminance and chromaticity (x, y). .

  When these powder phosphors are baked under conditions close to the baking conditions in the above-mentioned fluorescent lamp manufacturing process, the phosphor brightness and chromaticity are hardly changed in the phosphor of Comparative Example 1. In the phosphor mixture of Example 1, a decrease in luminance (5%) and a change in chromaticity (± 0.004) are observed.

  From this, it is considered that the composition and structure of the coating film or the antimony oxide to be coated have changed since the powder luminance has been slightly lowered due to the formation of the coating film (baking process) of the antimony oxide. It is done.

[Comparative Example 1]
In the phosphor preparation method, the obtained YVO phosphor powder (composition [YVO ₄ : Eu]) is prepared and subjected to powder evaluation with Example 1 described above. Further, a fluorescent lamp is manufactured by the above-described lamp manufacturing method and used for lamp evaluation with Example 2 below.

[Example 2]
The YVO phosphor obtained in the phosphor production method is wet-mixed with antimony oxide in the lamp production method to produce a fluorescent lamp. At this time, the antimony oxide Sb ₂ O ₃ is 0.2 parts by weight (Sb is 0.167 parts by weight) with respect to 100 parts by weight of the phosphor.

  Table 1 shows the initial (0 hr) chromaticity / relative luminous flux ratio and the chromaticity displacements Δx, Δy ([0 hr x (0 ()) after lighting for each time (100 hr, 500 hr) for the lamps of Example 2 and Comparative Example 1. y) value] − [x (y) value after elapse of each time]). This indicates a luminous flux maintenance factor. In the case of the lamp of Comparative Example 1 immediately after ramping (0 hour), the comparative example 1 has a higher luminous flux. After a lapse of time, the light is reversed and Example 2 has a higher luminous flux, and the luminous flux maintenance factor is almost 100% in Example 2, while the lamp of Comparative Example 2 shows a decrease of 10% or more. It can be seen that Example 2 is excellent in the luminous flux maintenance factor.

[Examples 3 and 4]
In the same manner as in Example 1, a phosphor mixture obtained by dry mixing was suspended in a 1% NC butyl acetate (tricellulose) solvent to prepare a phosphor binder, and thereafter, a lamp was manufactured by the above-described lamp manufacturing method. At this time, the antimony oxide Sb ₂ O ₃ in the dry mixing is expressed as 0.1 and 0.2 parts by weight (Sb is 0.0835 and 0.167 parts by weight) with respect to 100 parts by weight of the phosphor, respectively. As shown in FIG.

  Compared with the lamp of Comparative Example 2 below, as shown in Table 2, the luminous flux (lm) at the time of lamp production (0 hr) shows almost no difference from Example 3, but decreases in Example 4. The tendency to be seen is seen. The lamp characteristics after 100 hours have almost the same luminous flux maintenance factor as in Examples 3 and 4. However, Comparative Example 2 shows a decrease of 10% or more, and the luminous flux is lower than that in Example 4. Yes.

  As for chromaticity, in Comparative Example 2, the displacement amount Δx of the x value tends to decrease, while in the example, a tendency to increase is observed.

[Comparative Example 2]
In Example 2, the fluorescent lamp is manufactured without mixing the antimony oxide.

[Examples 5 to 9]
As Examples 5 to 9, Y (P, V) O ₄ phosphor obtained in the above phosphor production method, here Y (P _0.35 , V _0.65 ) O ₄ : Eu (manufactured by Nichia Corporation: NP- 310-10, emission wavelength 620 nm, 253.7 nm for excitation wavelength), in the above lamp manufacturing method, antimony oxide is wet mixed to manufacture a monochromatic fluorescent lamp. At this time, the antimony oxide Sb ₂ O ₃ is 0.2, 0.4, 0.6, 1.0, and 2.0 parts by weight as shown in Table 3 with respect to 100 parts by weight of the phosphor. , Sb amount is 0.167, 0.334, 0.501, 0.835, 1.670 parts by weight.

FIG. 1A shows the relative luminous flux of the fluorescent lamps of Examples 5 to 9 and Comparative Example 3 with respect to Comparative Example 3 at each time with respect to the lamp luminous flux after the lamp was manufactured (0 hour), 100 hours, 300 hours, and 500 hours. FIG. 1B shows the ratio (relative lm (%): [light beam of the example] / [light beam of the comparative example]). FIG. With respect to the luminous flux of the lamp after 500 hours, the luminous flux [luminous flux (100, 300, 500 hr)] after lighting for each hour with respect to the luminous flux [luminous flux (0 hr)] at the time of lamp production in each example and comparative example Ratio ([light flux (100, 300, 500 hr)] / [light flux (0 hr)]) is shown as an lm maintenance factor. That is, it shows the dependency of the light flux relative ratio and the light flux maintenance factor on the Sb amount (Sb ₂ O ₃ amount) and its temporal change. The luminous flux at the time of lamp production tends to be higher in Comparative Example 3 in the range of 4% or less. However, after 100 hours, the luminous flux maintenance factor of Examples 5 to 9 is approximately 100%, which is Comparative Example. A decrease of 10% or more is observed in the lamp No. 3. Thereby, the lamp light flux after 100 hours has passed is higher in Examples 5 to 9 than in Comparative Example 3 with a low light flux maintenance factor.

2A and 2B show the displacements (Δx and Δy) from the lamp production time (0 hour) for the chromaticities x and y of Examples 5 to 10 and Comparative Example 3, respectively, and the lamp lighting times (100 , 300, after 500 hours), and the dependence of the chromaticity point on the x and y displacement amounts Δx and Δy of the Sb amount and Sb ₂ O ₃ amount and its change over time.

[Comparative Example 3]
In Example 5 above, a fluorescent lamp is prepared without mixing antimony oxide.

[Examples 10 and 11]
As Examples 10 and 11, Y (P, V) O ₄ phosphor obtained in the above phosphor production method, and in the above lamp production method, antimony oxide is wet-mixed to produce a fluorescent lamp. At this time, as shown in Table 4, the antimony oxide Sb ₂ O ₃ is 0.1 and 0.2 parts by weight with respect to 100 parts by weight of the phosphor, respectively, and the Sb amounts are 0.0835 and 0.005, respectively. 167 parts by weight.

Similar to Examples 5 to 9 (FIGS. 1A and 1B), FIGS. 3A and 3B show the light flux relative ratio and the light flux maintenance factor of Comparative Example 4 at each lighting time. This shows the dependency of the maintenance rate on the amount of Sb (Sb ₂ O ₃ amount) and its change over time. 4A and 4B are similar to Examples 5 to 9 (FIGS. 2A and 2B), respectively, in FIGS. 4A and 4B, the chromaticity x and y are respectively displaced from the lamp production time (0 hour) ( Δx and Δy) are shown for each lamp lighting time (after 100, 300, 500 hours), and the dependency of x, y displacement amount Δx, Δy of chromaticity point on Sb amount / Sb ₂ O ₃ amount The time change is shown.

[Comparative Example 4]
In Example 10 above, a fluorescent lamp is prepared without mixing antimony oxide.

[Examples 12 to 14]
As Examples 13 to 15, a Y (P, V) O ₄ phosphor obtained by the above phosphor production method and the above lamp production method are prepared by wet mixing antimony oxide to produce a fluorescent lamp. At this time, as shown in Table 5, the antimony oxide Sb ₂ O ₃ is respectively 5, 10, 20 parts by weight with respect to 100 parts by weight of the phosphor, and the Sb amount is 4.175, 8.350, 16. 70 parts by weight.

FIGS. 5A and 5B show the luminous fluxes at the respective lighting times (after 0, 100, 300, and 500 hours) of the lamps of Examples 12 to 14 and the respective times as in Examples 5 to 9 (FIGS. 1A and B). The relative ratio of the light beam of the comparative example 5 and the light beam maintenance factor after 100, 300, 500 hours progress are shown. That is, it shows the dependency of the light flux relative ratio and the light flux maintenance factor on the Sb amount (Sb ₂ O ₃ amount) and its temporal change. 6A and 6B are similar to Examples 5 to 9 (FIGS. 2A and 2B), respectively, in FIGS. 6A and 6B, the chromaticity x and y are respectively displaced from the time of lamp production (0 hour) ( Δx and Δy) are shown for each lamp lighting time (100, 300, 500 hours), and the dependence of the chromaticity point on the x and y displacement amounts Δx and Δy of the Sb amount / Sb ₂ O ₃ amount and It shows the time change. Here, Example 12 after 300 hours of lighting is excluded from measurement due to lamp breakage.

The luminous flux at the time of producing the lamp has a simple decreasing tendency in the region (Examples 12 to 14) of 5 to 20 parts by weight of Sb ₂ O ₃ (4.175 to 16.70 parts by weight of Sb). It can be seen that the maintenance rate hardly changes. Compared with Comparative Example 5, the lamp luminous flux after 100 hours is lower in this range. From the above, in the range of 5 parts by weight with Sb ₂ O ₃ (4.175 important part with Sb), the initial lamp luminous flux is reduced by 10% or more as compared with Comparative Example 5, the lamp luminous flux after 100 hours is low, There is a tendency that Sb ₂ O ₃ is preferably used in an amount of 5 parts by weight or less (4.175 important part in Sb).

[Comparative Example 5]
In Example 12, the fluorescent lamp is prepared without mixing the antimony oxide.

[Examples 15 and 16]
In Examples 15 and 16, in the lamp manufacturing method, as shown in Table 6, the amount of antimony oxide (Sb ₂ O ₃ ) of Example 1 was 0.1 parts by weight (Sb was 0.0835 parts by weight). A dry-mixed YVO phosphor, a green-emitting BAM: Mn phosphor, and a blue-emitting BAM phosphor are wet-mixed with the above binder in a weight ratio of 40%: 20%: 40% to obtain white three-wavelength fluorescence. A lamp is referred to as Example 15. As shown in Table 6 as Example 16, the phosphor binder in which the amount of antimony oxide (Sb ₂ O ₃ ) in Example 2 was 0.1 parts by weight (Sb was 0.0835 parts by weight) was the same as described above. , BAM: Mn phosphor (green) and BAM phosphor (blue) are mixed to obtain a white three-wavelength fluorescent lamp by the above-described lamp manufacturing method.

  Table 6 shows the luminous flux and chromaticity point at the time of lamp manufacture, the relative ratio of the luminous flux with Comparative Example 6, the chromaticity point after 100 hours of lighting, and the luminous flux maintenance for Examples 15 and 16 and Comparative Example 6 described later. This indicates the rate / chromaticity point displacement.

  As is apparent from the table, it is understood that the luminous flux maintenance factor after 100 hours is improved as compared with Comparative Example 6 in both dry mixing and wet mixing.

Further, in the comparative example, Δx (the amount of displacement of the chromaticity x value) tends to decrease, whereas in the example, it tends to increase. From this, in the example, monochromatic red (Y (P, V) O ₄ ) Indicates that the light emission (flux) from the phosphor has not decreased.

[Comparative Example 6]
As Comparative Example 6, the fluorescent lamp manufactured in Example 15 without mixing antimony oxide is used.

  The phosphor of the present invention includes a fluorescent lamp for general illumination, a cold cathode fluorescent lamp or a flat lamp used for backlight of a liquid crystal display device such as a color or a single color, an Hg-enclosed flat lamp, a high-load fluorescent lamp, Or, in rare gas discharge lamps, etc., it is used as a red-light-emitting phosphor excited by ultraviolet light, and as a mixed phosphor of the red-light-emitting phosphor and phosphors of other emission colors, such as a three-wavelength phosphor, a white light source. In particular, the present invention can be applied to phosphors having good emission energy and luminous flux maintenance ratios in light-emitting devices, fluorescent lamps with small color change, and white light sources.

Examples 5-9, shows the amount of Sb (Sb ₂ O ₃ amount) dependency of the light beam relative ratio of Comparative Example 3 (Example] / [Comparative Example]), the time variation of the present invention. The figure which shows the light beam maintenance factor of Example 5-9 of this invention, the dependency on Sb amount (Sb2O3 amount) dependence of the comparative example 3, and its time change. Shows Examples 5-9 of the present invention, the amount of Sb (Sb ₂ O ₃ amount) dependence of the displacement ([Delta] x) of the chromaticity coordinates x of Comparative Example 3, the time change. Shows Examples 5-9 of the present invention, the amount of Sb (Sb ₂ O ₃ amount) dependence of the displacement of the chromaticity coordinate y of Comparative Example 3 ([Delta] y), the time change. Shows the embodiment 10, 11, Sb amount of the light beam relative ratio of Comparative Example 4 (Example] / [Comparative Example]) (Sb ₂ O ₃ amount) dependence of the present invention, the time variation. The figure which shows the light beam maintenance factor, Sb amount (Sb2O3 amount) dependence, and its time change of Examples 10 and 11 and Comparative Example 4 of the present invention. Shows examples 10 and 11 of the present invention, the amount of Sb (Sb ₂ O ₃ amount) dependence of the displacement ([Delta] x) of the chromaticity coordinates x of Comparative Example 4, the time change. Shows examples 10 and 11 of the present invention, the amount of Sb (Sb ₂ O ₃ amount) dependence of the displacement of the chromaticity coordinate y of Comparative Example 4 ([Delta] y), the time change. Examples 12 to 14, shows the amount of Sb (Sb ₂ O ₃ amount) dependency of the light beam relative ratio of Comparative Example 5 (Example] / [Comparative Example]), the time variation of the present invention. The figure which shows the light beam maintenance factor of Example 12-14 of this invention, the dependence on Sb amount (Sb2O3 amount) dependence, and its time change of the comparative example 5. FIG. Shows Examples 12 to 14 of the present invention, the amount of Sb (Sb ₂ O ₃ amount) dependence of the displacement ([Delta] x) of the chromaticity coordinates x of Comparative Example 5, the time change. Shows Examples 12 to 14 of the present invention, the amount of Sb (Sb ₂ O ₃ amount) dependence of the displacement of the chromaticity coordinate y of Comparative Example 5 ([Delta] y), the time change.

Claims (11)

Phosphors in which a rare earth vanadate activated with Eu or phosphor particles in which a part or all of the rare earth vanadate is substituted with a rare earth phosphate is coated with an antimony oxide . The light-emitting phosphor according to claim 1, wherein the phosphor is represented by a general formula of Y (V, P) O ₄ : Eu. The phosphor according to claim 2, wherein the general formula is Y (V _1−x , P _x ) O ₄ : Eu, and x is 0 ≦ x <1. The phosphor according to any one of claims 1 to 3, wherein the oxide of antimony is in a range of more than 0 parts by weight and 1 part by weight or less as Sb with respect to 100 parts by weight of the phosphor. The phosphor according to claim 4, wherein the antimony oxide is in a range of more than 0 parts by weight and 0.5 parts by weight or less as Sb with respect to 100 parts by weight of the phosphor. 6. A mixed phosphor for a white light source comprising the phosphor according to claim 1 as a red-emitting phosphor and further including blue and green-emitting phosphors. The mixed phosphor for a white light source according to claim 6, wherein the blue phosphor comprises a BaMgAl ₁₀ O ₁₉ : Eu phosphor. The green phosphor includes any one of BaMgAl ₁₀ O ₁₇ : Eu, Mn phosphor, (Ce, Tb) (Mg, Mn) Al ₁₁ O ₁₉ phosphor, and Zn ₂ SiO ₄ : Mn phosphor. The mixed phosphor of a white light source according to claim 6 or 7. 9. A cold cathode fluorescent lamp comprising the mixed phosphor according to claim 6 or a phosphor of each emission color. A fluorescent lamp comprising the phosphor according to claim 1. A fluorescent lamp comprising the mixed phosphor according to claim 6.

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