JPH09176633A - Phosphor, phosphor slurry, and fluorescent lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antimony-manganese-activated calcium halophosphate phosphor which has a high luminance and gives a fluorescent lamp having a high retention ratio of brightness, a phosphor slurry using the same, and a high-luminance highretention-ratio fluorescent lamp. SOLUTION: This phosphor is prepd. by attaching 0.1-5.0 pts.wt. fine LaPO4 particles to the surface of 100 pts.wt. antimony-manganese-activated calcium halophosphate phosphor represented by the general formula: 3Ca3 (PO4 )2 .Ca(F, Cl)2 :Sb, Mn. 0.1-5.0 pts.wt. fine M2 P2 O7 particles (wherein M is at least one element selected from among Ca, Sr, and Ba) may be added to the phosphor in addition to the LaPO4 particles.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phosphor, a phosphor slurry, and a fluorescent lamp, and particularly to an antimony-manganese-activated calcium halophosphate phosphor having little deterioration in emission luminance with time, and a phosphor using this phosphor. The present invention relates to a slurry and a fluorescent lamp formed using the phosphor slurry.

[0002]

2. Description of the Related Art Antimony / manganese-activated calcium halophosphate phosphors have been widely used as phosphors for fluorescent lamps for general lighting since they can obtain white light having an arbitrary color temperature by themselves. . However, the fluorescent lamp using the antimony / manganese-activated calcium halophosphate phosphor is inferior in performance to the three-wavelength fluorescent lamp in terms of brightness and color rendering property, and therefore tends to be gradually replaced by the three-wavelength fluorescent lamp. There is. However, since the product price is lower than that of the three-wavelength fluorescent lamp, the fluorescent lamp using the above calcium halophosphate phosphor still occupies an overwhelmingly dominant position in terms of the production amount and the diffusion rate. There is.

From the above technical background, some efforts have been made to increase the demand for inexpensive fluorescent lamps in order to improve the characteristics of antimony / manganese activated calcium halophosphate phosphors. Recently, especially, the three-wavelength type phosphor is mainly used to prevent the deterioration of the phosphor by irradiation ultraviolet rays by forming a protective film on the surface of the phosphor or a fluorescent lamp, and to suppress the reaction with glass. Measures for preventing the reduction of the emission brightness of the phosphor due to the scattering and adhesion of mercury compounds or emitter substances have been studied.

[0004]

However, in the fluorescent lamp using the antimony / manganese activated calcium halophosphate phosphor, the maintenance ratio of the brightness during lighting (the brightness after lighting for a predetermined time relative to the initial brightness) However, the expensive three-wavelength fluorescent lamp is inevitably used in an application or place where performance is important, resulting in an increase in lighting equipment cost. Therefore, in order to expand the application of inexpensive fluorescent lamps using calcium halophosphate phosphors and increase the demand, it is necessary to improve the emission characteristics of antimony-manganese activated calcium halophosphate phosphors, especially the maintenance rate of brightness. It is a technical issue.

The present invention has been made to solve the above-mentioned problems, and an antimony-manganese-activated calcium halophosphate phosphor having a high emission brightness and a high brightness maintenance rate when used in a fluorescent lamp. An object of the present invention is to provide a phosphor slurry using this phosphor and a fluorescent lamp of high brightness and high maintenance rate type.

[0006]

In order to achieve the above object, the present inventor has found that the general formula 3Ca ₃ (PO ₄ ) ₂ .C
a (F, Cl) ₂ : antimony represented by Sb, Mn
Various additives are mixed with manganese-activated calcium halophosphate phosphor to prepare a phosphor slurry, and the phosphor slurry is applied to the inner surface of the glass tube, dried and baked to form a fluorescent lamp. The effects of factors such as the type and amount of the lamp on the lamp characteristics were investigated in detail by experiments and a comparative study was conducted. As a result, the weight ratio to the phosphor is 0.1 to
When using a phosphor in which 5.0% of LaPO ₄ particles are attached to the surface of the phosphor as a light emitting layer of a fluorescent lamp,
It has been found that the luminous brightness is high and the luminous flux maintenance factor after a predetermined time is high.

In addition to the above LaPO ₄ fine particles, C
When fine particles of pyrophosphate of alkaline earth metal such as a, Sr, and Ba are attached to the surface of the phosphor at a weight ratio of 0.1 to 5.0%, the emission brightness of the fluorescent lamp is particularly high. It has also been found that the luminous flux maintenance factor is increased and the luminous flux maintenance factor is improved.

As a result of further detailed investigations, experiments, and studies, the above LaPO ₄ fine particles and alkaline earth metal pyrophosphate fine particles were suspended in a conventional antimony-manganese-activated calcium halophosphate phosphor. Also in the case of suspending 0.1 to 5.0% by weight in the body slurry,
It was found that the same improvement effect as in the case of attaching as described above can be obtained.

Further, as LaPO ₄ fine particles, La ₂
La compounds such as O ₃ and La ₂ (CO ₃ ) ₃ are dissolved in nitric acid and then (NH ₄ ) ₂ HPO ₄ and NH ₄ H ₂ PO
It has been found that the use of fine particles formed from the precipitation of LaPO ₄ formed by reacting with ₄ is more effective in improving the properties of the phosphor.

Further, LaPO produced by the above reaction
_When the precipitate of ₄ is separated and produced from the reaction solution, an appropriate amount of nitrate ion is left to be contained in the phosphor slurry in the range of 100 to 10000 ppm by weight ratio to the phosphor, thereby further improving the characteristics of the phosphor film. The knowledge that it can be obtained was also obtained. The present invention has been completed based on the above findings.

That is, the first phosphor according to the present invention has the general formula 3Ca ₃ (PO ₄ ) ₂ .Ca (F, Cl) ₂ : S.
It is characterized in that 0.1 to 5.0% by weight of LaPO ₄ fine particles are adhered to the surface of the antimony / manganese activated calcium halophosphate phosphor represented by b and Mn.

The second phosphor according to the present invention has the general formula 3Ca ₃ (PO ₄ ) ₂ .Ca (F, Cl) ₂ : Sb,
On the surface of the antimony / manganese-activated calcium halophosphate phosphor represented by Mn, fine particles of LaPO ₄ and M ₂ P ₂
It is characterized in that fine particles of O ₇ (wherein M is at least one element selected from Ca, Sr and Ba) are deposited by 0.1 to 5.0% by weight respectively.

Furthermore, the first phosphor slurry according to the present invention comprises a water-soluble binder and a general formula 3Ca ₃ (PO ₄ ) ₂
In a phosphor slurry in which an antimony / manganese activated calcium halophosphate phosphor represented by Ca (F, Cl) ₂ : Sb, Mn is suspended, the antimony / manganese activated calcium halophosphate phosphor is It is characterized in that fine particles of LaPO ₄ are suspended in the slurry by 0.1 to 5.0% by weight.

The second phosphor slurry according to the present invention comprises a water-soluble binder and a general formula 3Ca ₃ (PO ₄ ) ₂
In a phosphor slurry in which an antimony / manganese activated calcium halophosphate phosphor represented by Ca (F, Cl) ₂ : Sb, Mn is suspended, the antimony / manganese activated calcium halophosphate phosphor is LaPO ₄ particles and M ₂ P ₂ O ₇ (where M is Ca, Sr and B
Fine particles of at least one element selected from a) and 0.1 to 5.0% by weight of each are suspended in the slurry.

Further, the amount of nitrate ion contained in the phosphor slurry is 100 to 10,000 ppm in weight ratio to the antimony-manganese activated calcium halophosphate phosphor.
Is set.

The first fluorescent lamp according to the present invention includes a light-transmissive glass tube filled with a sealing gas containing mercury and a rare gas, and a phosphor layer formed on the inner wall surface of the light-transmissive glass tube. In the low-pressure mercury vapor discharge type fluorescent lamp, which comprises means for maintaining a positive column discharge in the enclosed gas, the phosphor layer has the general formula 3Ca ₃ (PO ₄ ).
₂ · Ca (F, Cl) ₂ : antimony / manganese activated calcium halophosphate phosphor represented by Sb, Mn L on the surface
It is characterized in that it contains a phosphor having 0.1 to 5.0% by weight of fine particles of aPO ₄ attached.

Further, the second fluorescent lamp according to the present invention is
A light-transmissive glass tube filled with a sealing gas containing mercury and a rare gas, a phosphor layer formed on the inner wall surface of the light-transmitting glass tube, and means for maintaining positive column discharge in the sealing gas. In a low-pressure mercury vapor discharge type fluorescent lamp having the following structure, the phosphor layer has a general formula: 3Ca ₃ (P
O ₄ ) ₂ · Ca (F, Cl) ₂ : Sb, Mn antimony / manganese activated calcium halophosphate phosphor surface with LaPO ₄ particles and M ₂ P ₂ O ₇ (provided that M
Is 0.1 to 5.0% by weight of fine particles of at least one element selected from Ca, Sr and Ba.
It is characterized in that it contains an attached phosphor.

Here, the fine particles of LaPO ₄ are contained in the range of 0.1 to 5.0% by weight ratio to the phosphor in order to improve the emission brightness of the calcium halophosphate phosphor.

The content of LaPO ₄ fine particles is 0.1% by weight.
If the amount is less than the lower limit, the effect of improving the emission brightness is insufficient. On the other hand, when the content exceeds 5.0% by weight, LaPO ₄ itself is not a light-emitting substance, so that the emission brightness of the phosphor is rather lowered, or when the fluorescent lamp is formed, the light-emission coated surface is not coated. It becomes rough and a so-called defective product is likely to occur. Therefore, the content ratio of LaPO ₄ fine particles is always 0.1 to 5.0 with respect to the weight of the phosphor.
It is set within the range of%.

Fine particles of M ₂ P ₂ O ₇ (where M is at least one element selected from Ca, Sr and Ba) which is an alkaline earth metal pyrophosphate are the above-mentioned L
When added and contained in combination with the fine particles of aPO ₄ , it exerts the effect of further improving the emission brightness of the phosphor, and is added and contained in the range of 0.1 to 5.0 wt% with respect to the phosphor. . When the content is less than 0.1% by weight, the effect of improving the emission brightness is small, while when it exceeds 5.0%, the emission brightness is rather lowered.

The fine particles of LaPO ₄ and M ₂ P ₂ O _{7 referred to} here are particles having an average particle diameter of 2 μm or less. Since the average particle size of the phosphor is usually 3 to 10 μm, the phosphor particles are evenly attached to the surface of the phosphor particles, or LaPO ₄ and M ₂ P ₂ O ₇ particles are evenly distributed in the spaces between the adjacent phosphor particles. Average particle size of 2μm
The following LaPO ₄ fine particles and M ₂ P ₂ O ₇ fine particles are preferably used.

As the LaPO ₄ fine particles, commercially available LaPO ₄ powder may be finely pulverized using, for example, a glass bead mill. However, in order to obtain fine particles having better dispersibility, it is preferable to use the one prepared by the following precipitation method. That is, a La compound such as La ₂ O ₃ is dissolved in an acid such as nitric acid, and (NH ₄ ) ₂ HPO ₄ or N is added to the resulting solution.
H ₄ H ₂ PO ₄ , NH ₃ etc. were added and reacted to obtain La,
A precipitate of PO ₄ is formed. Then, after washing this precipitate, it is possible to use it as a slurry as it is. Further, the slurry can be dried and then pulverized to be used as a fine particle powder.

Further, the nitrate ion contained in the reaction solution when the LaPO ₄ precipitate is formed may be completely removed by a sufficient washing operation. However, when the nitrate ion content in the phosphor slurry is set in the range of 100 to 10000 ppm by weight ratio to the phosphor, the dispersibility of LaPO ₄ fine particles is improved, and the effect of improving the emission brightness of the phosphor is enhanced. . If the amount of nitrate ions is less than 100 ppm, the above-mentioned improvement effect is small, while if it exceeds 10,000 ppm, blackening is likely to occur during lighting of the fluorescent lamp, and the commercial value of the fluorescent lamp is significantly impaired.

In the present invention, when the phosphor is suspended in a binder to prepare a phosphor slurry without preliminarily depositing the LaPO ₄ particles on the surface of the phosphor, the LaPO ₄ particles are added to the slurry. In a weight ratio of 0.1
Even when the phosphor slurry is prepared by suspending 5.0%, the same action and effect as when the LaPO ₄ fine particles are previously attached to the phosphor surface can be obtained. Also in this case, in addition to the LaPO ₄ fine particles, M ₂ P ₂ O ₇ (where M is at least one element selected from Ca, Sr, and Ba) fine particles in a weight ratio of 0.1 to 5.
A larger effect of improving the lamp characteristics can be obtained by the composite suspension of 0%.

According to the phosphor and the phosphor slurry having the above-mentioned constitution, the LaPO ₄ fine particles are added to the surface of the antimony / manganese activated calcium halophosphate phosphor, which was insufficient in terms of the brightness maintenance ratio, in a weight ratio of 0. Since 1 to 5.0% is adhered, the maintenance factor of the brightness of the phosphor is significantly improved and the emission brightness can be improved. In particular, in addition to the above LaPO ₄ fine particles, Ca, Sr,
By combining fine particles of Ba pyrophosphate in a weight ratio of 0.1 to 5.0%, the brightness maintenance ratio and the emission brightness of the phosphor can be further improved.

Further, according to the fluorescent lamp of the present invention, since the light emitting layer is formed by using an inexpensive phosphor that provides excellent emission brightness and a greatly improved luminous flux maintenance factor, inexpensive general lighting is provided. The range of applications of fluorescent lamps for automobiles can be greatly expanded.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the present invention will be described.
A more specific description will be given based on the following examples.

Example 1 La ₂ O ₃ was dissolved in nitric acid, and (NH ₄ ) was added to the solution.
₂ HPO ₄ was added and reacted to produce a LaPO ₄ precipitate. The precipitate was washed, dried, and then pulverized to obtain LaPO ₄ fine particles having an average particle size of 0.2 μm.

100 g of the LaPO ₄ fine particles are dispersed in 20 liters of pure water, and 10 kg of an antimony-manganese activated calcium halophosphate phosphor having an average particle size of 6 μm.
Was charged and sufficiently stirred to obtain a mixed solution. Further, the phosphor according to Example 1 was prepared by filtering, drying and sieving the mixed solution. This phosphor is used as a scanning electron microscope (S
EM) When observed with a photograph, LaPO
₄ Fine particles were uniformly attached. Also, as a result of the analysis, L
It was confirmed that the aPO ₄ fine particles were present in 1.0% by weight ratio with respect to the phosphor.

Next, the phosphor according to Example 1 was uniformly dispersed in a water-soluble binder in which polyethylene oxide was dissolved to prepare a phosphor slurry. Next, the obtained phosphor slurry was applied to the inner surface of the glass bulb, dried and baked to integrally form a light emitting layer (phosphor film). Thereafter, in accordance with the normal lamp manufacturing process, Example 1
20W fluorescent lamp (FL20SS W / 18 type)
Was manufactured.

On the other hand, as Comparative Example 1, a phosphor slurry was prepared in the same manner as in Example 1 except that no LaPO ₄ fine particles were added, and the slurry was applied to the inner surface of the glass bulb, followed by drying and firing. A 20 W fluorescent lamp according to a comparative example having the same type as that of Example 1 was manufactured.

In order to evaluate the characteristics of the thus-produced fluorescent lamps according to Example 1 and Comparative Example,
The initial total luminous flux and the luminous flux maintenance factor after 1000 hours of lighting were measured. As a result, the initial total luminous flux of the fluorescent lamp according to Example 1 was 103 when the fluorescent substance of the conventional comparative example was 100. In addition, the luminous flux maintenance factor after 1000 hours of lighting was significantly reduced to 85% in the comparative example,
In Example 1, it was maintained at 92, which is excellent. That is, according to this example, it was found that the initial total luminous flux and the luminous flux maintenance factor after 1000 hours of lighting were significantly improved.

Further, without attaching the pre LaPO ₄ particles antimony-manganese activated halophosphate calcium phosphor surface, LaPO ₄ particles against halophosphate calcium phosphor 10kg when phosphor slurry prepared was prepared by the method Was mixed at a ratio of 100 g, and the same effect as in Example 1 was obtained when the FL20SS W / 18 type fluorescent lamp was used by using the obtained phosphor slurry. That is, it was confirmed that even when LaPO ₄ fine particles were not previously attached and were suspended in the slurry during the preparation of the phosphor slurry, the same effect as when previously attached was obtained.

Example 2 A LaPO ₄ fine particle precipitate was produced in the same manner as in Example 1, and this precipitate was thoroughly washed to adjust the slurry concentration so that the solid content was 20% by weight. 500 g of this slurry was weighed and dispersed in 20 liters of pure water, 10 kg of antimony-manganese-activated calcium halophosphate phosphor was added, and the mixture was sufficiently stirred to obtain a mixed solution. Furthermore, the mixed liquid was filtered, dried, and sieved to prepare the phosphor according to Example 2. Observation of this phosphor with a scanning electron microscope (SEM) photograph showed that the LaPO ₄ particles were less aggregated than in the method of Example 1, and that the LaPO ₄ particles were uniformly attached to the surface of each phosphor.
As a result of the analysis, it was confirmed that the LaPO ₄ fine particles were present in 1.0% by weight ratio with respect to the phosphor.

Then, in the same manner as in Example 1, the above-mentioned Example 2 was added to a water-soluble binder in which polyethylene oxide was dissolved.
The phosphor according to (1) was uniformly dispersed to prepare a phosphor slurry. Next, the obtained phosphor slurry was applied to the inner surface of the glass bulb, dried and baked to integrally form a light emitting layer (phosphor film). Thereafter, according to the normal lamp manufacturing process, the 20 W fluorescent lamp (FL20
SS W / 18 type) was manufactured.

In order to evaluate the characteristics of the thus manufactured fluorescent lamp according to Example 2, the initial total luminous flux and the luminous flux maintenance factor after 1000 hours of lighting were measured. As a result, the initial total luminous flux of the fluorescent lamp according to Example 2 was 102 when the fluorescent substance of the conventional comparative example was 100. In addition, the luminous flux maintenance factor after 1000 hours of lighting was significantly reduced to 85% in the comparative example, but was well maintained at 91 in Example 2. That is, according to this example, it was found that the initial total luminous flux and the luminous flux maintenance factor after 1000 hours of lighting were significantly improved.

Further, without attaching the pre LaPO ₄ particles antimony-manganese activated halophosphate calcium phosphor surface, LaPO ₄ slurry against halophosphate calcium phosphor 10kg when phosphor slurry prepared was prepared by the method Was mixed at a ratio of 500 g, and the same effect as that of Example 2 was obtained when the FL20SS W / 18 type fluorescent lamp was used by using the obtained phosphor slurry. That is, without depositing LaPO ₄ fine particles in advance,
It was confirmed that even when the phosphor was suspended in the slurry at the time of preparation, the same effect as when the phosphor was previously attached was obtained.

Example 3 A precipitate of LaPO ₄ was produced in the same manner as in Example 2, and the washing conditions for this precipitate were relaxed as compared with Example 2, whereby
The amount of nitrate ions in the LaPO ₄ slurry is 1000
The content was adjusted to 0 ppm and the solid content was adjusted to 20% by weight.

Next, 10 kg of antimony / manganese activated calcium halophosphate phosphor was mixed with the LaPO ₄ precipitation slurry prepared by the above method so that the actual content of LaPO ₄ was 100 g. A phosphor slurry according to Example 3 was prepared. As a result of analyzing this phosphor slurry, nitrate ion was 1000 p
It was found that pm existed.

The FL20SS W / 18 type fluorescent lamp was manufactured by applying this phosphor slurry to the inner surface of the glass bulb in the same manner as in Examples 1 and 2, followed by drying and firing.

In order to evaluate the characteristics of the thus manufactured fluorescent lamp according to Example 3, the initial total luminous flux and the luminous flux maintenance factor after 1000 hours of lighting were measured. As a result, the initial total luminous flux of the fluorescent lamp according to Example 3 was 102 when the fluorescent substance of the conventional comparative example was 100. Further, the luminous flux maintenance factor after 1000 hours of lighting was drastically reduced to 85% in the comparative example, but was well maintained at 91 in Example 3. That is, according to this example, it was found that the initial total luminous flux and the luminous flux maintenance factor after 1000 hours of lighting were significantly improved.

Example 4 100 g of LaPO ₄ fine particles prepared in Example 1
While weighing, Ca ₂ P ₂ O ₇ obtained by firing CaHPO ₄ at a temperature of 900 ° C. was finely pulverized to weigh 100 g of fine particles having an average particle diameter of 1 μm. Next, LaPO ₄ fine particles and Ca ₂ P ₂ O ₇ fine particles were dispersed in 20 liters of pure water. Further, 10 parts of the antimony / manganese activated calcium halophosphate phosphor prepared in Example 1 was added to this dispersion.
kg was added, and the mixture was sufficiently stirred to obtain a mixed solution. By filtering, drying and sieving this mixed solution in the same manner as in Example 1,
The phosphor according to Example 4 was prepared. As a result of analyzing this phosphor, it was confirmed that LaPO ₄ fine particles were present in 1.0% by weight ratio to the phosphor, while Ca ₂ P ₂ O ₇ fine particles were also present in 1.0%. It was

Using this phosphor, a phosphor slurry was prepared in the same manner as in Example 1, and an FL20SS W / 18 fluorescent lamp was manufactured using this phosphor slurry, and the same lamp characteristics were obtained. evaluated. As a result, the initial total luminous flux of the fluorescent lamp according to Example 4 was 105 when the fluorescent substance of the conventional comparative example was 100. Again 1000
The luminous flux maintenance factor after long-time lighting was significantly reduced to 85% in the comparative example, but was 94, which was maintained well in Example 4. That is, according to this example, since Ca ₂ P ₂ O ₇ fine particles coexisted in addition to LaPO ₄ fine particles, it was found that the initial total luminous flux and the luminous flux maintenance factor after 1000 hours of lighting were significantly improved. did.

Examples 5 to 19 In accordance with the processing methods shown in Examples 1 to 4, the contents of LaPO ₄ fine particles, the content of Ca ₂ P ₂ O ₇ fine particles and the amount of nitrate ions in the phosphor slurry are shown. The phosphor and the phosphor slurry were prepared by changing the value within the range of 1 and the phosphor slurry was used to manufacture FL20SSW / 18 fluorescent lamps according to Examples 5 to 19, respectively. For each fluorescent lamp, the initial total luminous flux and the luminous flux maintenance factor after 1000 hours of lighting were measured in the same manner as in Examples 1 to 4. The measurement results are collectively shown in Table 1 below together with the measurement results of Examples 1 to 4 above.

[0045]

[Table 1]

As is clear from the results shown in Table 1 above,
In the fluorescent lamps of the respective examples in which a predetermined amount of LaPO ₄ fine particles were adhered to the surface of the calcium halophosphate phosphor or the phosphor composition suspended in the phosphor slurry was used, the LaPO ₄ fine particles were not contained at all. It has been proved that each of them has a high initial total luminous flux and an excellent luminous flux maintenance rate as compared with the conventional fluorescent lamps that do not include them, and that good lamp characteristics are exhibited.

In the above embodiment, M ₂ O ₂ P
₇ shows an example in which Ca ₂ P ₂ O ₇ fine particles are used as the fine particles _7, but in addition, strontium pyrophosphate (Sr ₂
Similar effects are obtained when P ₂ O ₇ ) or barium pyrophosphate (Ba ₂ P ₂ O ₇ ) is used.

[0048]

As described above, according to the phosphor and the phosphor slurry according to the present invention, the LaPO ₄ is deposited on the surface of the antimony / manganese activated calcium halophosphate phosphor, which is insufficient in maintaining the brightness. The weight ratio of the fine particles to 0.
Since 1 to 5.0% is attached, the maintenance factor of the brightness of the phosphor is significantly improved and the emission brightness can be improved. Especially in addition to the above LaPO ₄ fine particles,
By adding fine particles of Ca, Sr, and Ba pyrophosphate compositely in an amount of 0.1 to 5.0% by weight, the brightness maintenance ratio and the emission brightness of the phosphor can be further improved. .

Further, according to the fluorescent lamp of the present invention, since the light emitting layer is formed by using an inexpensive phosphor that provides excellent emission brightness and a significantly improved luminous flux maintenance factor, inexpensive general lighting is provided. The range of applications of fluorescent lamps for automobiles can be greatly expanded.

Claims (7)

[Claims] 1. The general formula 3Ca ₃ (PO ₄ ) ₂ · Ca
(F, Cl) ₂ : Sb, Mn antimony / manganese activated calcium halophosphate phosphor LaPO _{4 on the} surface
0.1% to 5.0% by weight of fine particles are attached to the phosphor. 2. The general formula 3Ca ₃ (PO ₄ ) ₂ · Ca
(F, Cl) ₂ : Sb. LaPO _{4 on the} surface of an antimony / manganese activated calcium halophosphate phosphor represented by Mn
And fine particles of M ₂ P ₂ O ₇ (where M is at least one element selected from Ca, Sr and Ba) are deposited by 0.1 to 5.0% by weight, respectively. Characteristic phosphor. 3. A water-soluble binder comprising the general formula 3Ca ₃
(PO ₄ ) ₂ · Ca (F, Cl) ₂ : Sb, Mn In the phosphor slurry in which the antimony / manganese-activated calcium halophosphate phosphor is suspended, the above-mentioned antimony / manganese-activated calcium halophosphate fluorescence is used. For the body
LaPO ₄ particles are added to the slurry in a weight ratio of 0.1 to 0.1
A phosphor slurry characterized by being suspended at 5.0%. 4. A water-soluble binder containing the general formula 3Ca ₃
(PO ₄ ) ₂ · Ca (F, Cl) ₂ : Sb, Mn In the phosphor slurry in which the antimony / manganese-activated calcium halophosphate phosphor is suspended, the above-mentioned antimony / manganese-activated calcium halophosphate fluorescence is used. For the body
LaPO ₄ fine particles and M ₂ P ₂ O ₇ (where M is Ca,
(At least one element selected from Sr and Ba)
And the fine particles of
A phosphor slurry characterized by being suspended at 5.0%. 5. The amount of nitrate ion contained in the phosphor slurry is set to 100 to 10000 ppm by weight ratio to the antimony-manganese activated calcium halophosphate phosphor. Phosphor slurry. 6. A light-transmissive glass tube filled with a filling gas containing mercury and a rare gas, a phosphor layer formed on the inner wall surface of the light-transmitting glass tube, and a positive column discharge is maintained in the filling gas. In the low-pressure mercury vapor discharge type fluorescent lamp, the phosphor layer has the general formula:
Ca ₃ (PO ₄ ) ₂ · Ca (F, Cl) ₂ : Sb, Mn
0.1 to in antimony-manganese activated halophosphate calcium phosphor surface shown fine particles of LaPO ₄ in weight ratio
A fluorescent lamp containing 5.0% adhered phosphor. 7. A light-transmissive glass tube filled with a sealing gas containing mercury and a rare gas, a phosphor layer formed on the inner wall surface of the light-transmitting glass tube, and a positive column discharge maintained in the sealing gas. In the low-pressure mercury vapor discharge type fluorescent lamp, the phosphor layer has the general formula:
Ca ₃ (PO ₄ ) ₂ · Ca (F, Cl) ₂ : Sb, Mn
The fine particles of LaPO ₄ and M ₂ P ₂ O ₇ are formed on the surface of the antimony / manganese-activated calcium halophosphate phosphor represented by
(Provided that M is at least one element selected from Ca, Sr and Ba) in a weight ratio of 0.1
A fluorescent lamp characterized by containing ~ 5.0% adhered phosphor.