JPH02173087A - Phosphor and fluorescent lamp - Google Patents

Abstract

PURPOSE:To obtain a green emitting phosphor free from discoloration during lighting of a high-load fluorescent lamp, showing a high luminous output, and giving stable lamp characteristics by forming a composition represented by a specified formula. CONSTITUTION:A Ce- or Tb-activated phosphor represented by formula I (wherein Re is at least one of Y, La, and Gd; a>0, b>0, 0<a+b<1, e>=0, f>=0, g>0, an 0.8>=e+f+g <=1.30) or formula II (wherein Re, a, and b are as defined above; x>=0; y>0; 5X10<-6=z<=6X10<-3>), wherein the contact electrification charge on the surface of phosphor per unit weight, under a load on the tube wall of 0.055W/cm<2> or higher, is between that of an alpha-Al2O3 powder (having a particle diameter of about 0.1mum) and that of an SiO2 powder (having a particle diameter of about 2.0mum). This phosphor does not cause discoloration during lighting of a high-load fluorescent lamp (0.055W/cm<2> or higher). Therefore, a fluorescent lamp made by using a green emitting phosphor showing a high luminous output and giving stable lamp characteristics can be obtained.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) This invention provides a green-emitting rare earth aluminate/silicic acid/phosphate phosphor or a rare earth boric acid/(silicic acid) activated with cerium and terbium. - It relates to a phosphate phosphor or a rare earth orthophosphate phosphor, and in particular to a phosphor and a fluorescent lamp that emit green light suitable for a three-wavelength fluorescent lamp with a high tube load.

(Prior Art) In recent years, three-wavelength fluorescent lamps that simultaneously satisfy high color rendering properties and high efficiency have become widely used as general lighting fluorescent lamps. This type of fluorescent lamp uses blue, green, and red emitting phosphors that have a relatively narrow band emission spectral distribution.

Conventionally, as a green-emitting rare earth aluminate/silicic acid/phosphate phosphor activated with cerium and terbium, [(R
e, Tb, Ce)20*AlI20* ・SiO2・P
2O3] (Japanese Patent Publication No. 60-9543) is known. In addition, rare earth boric acid/silicic acid/phosphate phosphors include [
(Re.

Tb, Ce) 03 5i02 P20SB
20. ] () There is Komei Publication No. 62-44792.

Alternatively, as a rare earth orthophosphate phosphor, [(Re, T
b, Ce) PO4] (Japanese Patent Publication No. 59-43508) is known.

In addition, in pressure wavelength range fluorescent lamps, the proportion of the green light emitting phosphor in the total luminous flux (emission output) is very high, so the characteristics of the green light emitting phosphor are different from those of pressure wavelength range fluorescent lamps. Significantly affects performance.

(Problems to be Solved by the Invention) Therefore, in a pressure wavelength range emission type fluorescent lamp, it is necessary to use a green-emitting phosphor that has excellent performance and is stable. However, conventional rare earth aluminate/silicic acid/phosphate phosphors, rare earth boric acid/(silicic acid)/phosphate phosphors, or rare earth orthophosphate phosphors are more difficult to use in high-load fluorescent lamps (than red-emitting phosphors). During lighting at a power of 0,055 W/cm2 or more), a significant coloring phenomenon is observed, which is presumed to be due to reaction with mercury adsorbed, absorbed, and remaining on the surface layer of the phosphor.

As a result, not only did the product value suffer greatly,
The reduction in light emission output was also large, which was a problem.

After conducting extensive research, experimentation, and analysis of the cause, we found that the blue (light brown) phenomenon, which is presumed to be caused by a reaction with mercury adsorbed, absorbed, and remaining on the surface layer of the phosphor, is due to the amount of contact charge on the surface of the phosphor. It was found that there was a close correlation between

That is, it has been found that the coloring phenomenon changes significantly depending on the difference in the amount of contact charge on the surface of the phosphor, and as a result, it has been found that the light emission output is also greatly affected.

As described above, there is a desire for a green light-emitting phosphor for pressure wavelength range fluorescent lamps that has a high luminous output and exhibits a small coloring phenomenon during lighting of the fluorescent lamp.

Therefore, this invention was made to solve the above problems, and it is a fluorescent lamp of high load (0,055W/cj) that has a high light emission output, and a fluorescent lamp of this type that has a small coloring phenomenon during lighting. The object of the present invention is to provide a green-emitting rare earth aluminate/silicic acid/phosphate phosphor, a rare earth boric acid/(silicic acid)/phosphate phosphor, or a rare earth orthophosphate phosphor and a fluorescent lamp.

[Structure of the Invention] (Means for Solving the Problems) This invention provides a formula CRel-m-b Tba Ceb )20*eAJ activated with cerium and terbium.
203 ・f Si02 ・gP20% (
However, Re is yttrium (Y) or lanthanum (La).

At least one type selected from gadolinium (Gd), and ag0, b>0. O<a+b<1゜e≧O, f≧
0. g>0.0.8≦e+ f +g≦1.30), or (Re r-a-bT baCe 11) 203
e xS f02 a yP205 ・z132
0, (However, Re is yttrium (Y), lanthanum (L)
a).

At least one selected from gadolinium (Gd), and a>0. b>0, O<a+b<1°X≧O,y>
0.5X10-"≦z≦6X10-3), and when the tube wall load is 0.055W/cm2 or more, the contact charge amount of the phosphor surface per unit weight is a-AfIzOi powder (particle size of about 0 .1μm) and SiO2 powder (particle size approx. 2.0μm)
m) is the phosphor located between.

In addition, the particle size of about 0.1 μm means 0.03 to 0.1 μm.
The particle size of about 2.0 um refers to the range from 0.5 to 2.0 um.

Further, the present invention includes a phosphor film made of the above-mentioned phosphor,
This fluorescent lamp has a wall load of 0.055 W/cm2 or more.

(Function) According to the present invention, the green light-emitting phosphor does not cause any coloring phenomenon during lighting in a high-load fluorescent lamp (0,055 W/cm2 or more), and very stable lamp characteristics can be obtained.

That is, this effect is achieved when the pipe wall load is 0.055vlc-
This is noticeable in the above-mentioned fluorescent lamps, and in fluorescent lamps with a wall load of less than 0.055 V/c, the effect is hardly recognized, or even if it is recognized, the effect is It is extremely small (see Figure 1).

Furthermore, if the contact zone M amount on the surface of the phosphor is more polar than α-AI20s powder (particle size approximately 0.1 μm) and its absolute value is larger, and SiO2 powder (particle size approximately 260 μm
) If the polarity is negative and its absolute value is large, when used in a high-load fluorescent lamp (0,055w/(44 or more)), a significant coloring phenomenon will occur, the commercial value will be significantly impaired, and the discharge will not occur. It becomes stable and becomes practically unusable (see Figure 2).

Furthermore, Figure 2 shows exactly the same tendency for green-emitting rare earth aluminate/silicic acid/phosphate phosphors, rare earth boric acid/(silicic acid)/phosphate phosphors, or rare earth orthophosphate phosphors. There is a clear correspondence between the contact charging order and the degree of coloring phenomenon.

In addition, to determine the n1 contact charge amount of the phosphor particles, a commercially available suction type Faraday cage method device was used, and a trial sample for Δ#1 determination was pretreated in a polypropylene container. Using.

Furthermore, the coloring phenomenon during lighting is closely related to the amount of mercury adsorbed/absorbed on the phosphor surface, and there is a positive correlation between the difference in coloring phenomenon and the amount of mercury adsorbed/absorbed. It is acceptable.

From this, it can be seen that the amount of contact charge on the surface of the phosphor of the present invention per unit weight is α-AI? zOi powder (particle size approximately 0.1μm
) and SiO2 powder (particle size approximately 2.0 μm), the green-emitting rare earth phosphor is present in a high-load fluorescent lamp (0.05μm).
5V/c- or more), the light emitting output is high, and the coloring phenomenon during lighting is small, making a great contribution to practical application.

(Example) Hereinafter, regarding the phosphor according to the example (2 examples) of this invention,
The manufacturing method will be explained in detail.

Example-1 First, 3g of beer containing 2I of pure water was prepared by a conventional method (Lag, 6oTb., , Ce0,
2. ), O, eO, IAN203'0.1Si02 Q
200 g of green-emitting phosphor expressed as O,95p20
Put in. The Bee Power containing the phosphor suspension was attached to a commercially available ultrasonic cleaner (50 kHz), and ultrasonic cleaning was performed for 10 minutes.

After washing, the supernatant liquid was removed by decantation, filtered, and dried. When the contact charge amount of this phosphor was determined by Δ-1, it was -1,0XIO-"c (coulomb) 7g. At the same time, the contact charge amount of the conventional phosphor without ultrasonic cleaning, a- AfizO1 powder (particle size approximately 0.1
μm) and Sin, that of powder (particle size approximately 2.0 μm) is -1,0XIO-'c/g, +1. Ox1
0-"c/g, -8,Ox 10-"c/g.

Furthermore, a 4-watt fluorescent lamp FL-4 (15.5 mm
φ) (tube load 0.11 V/cj), the fluorescent lamps were lit for 500 hours, and the degree of coloring (light brown) of the fluorescent lamps was classified into 7 grades from A rank to C- rank. , planned.

The degree of coloring of the fluorescent lamp using the green-emitting phosphor of the present invention was A-rank, while that of the conventional green-emitting phosphor was C-rank.

In addition, the seven levels of the degree of red color phenomenon were classified as follows.

Palanque: No coloring phenomenon observed. A-rank...
Very slight coloring is observed.

B rank: Slight coloring is observed. B-rank・
...Some coloring is observed.

C rank: light brown coloring is observed. C-rank: The degree of light brown coloring is inferior to that of C-rank. C
-Rank...brown coloration is observed.

Example-2 First, in a 3I pyrolysis solution containing 2 g of pure water, the following were prepared by a conventional method (La0, 4.Tb0, , 6Ce, .
5. )20, e0, 2 S i 02
#0, 96 P 2 05 dispute 4 X 1
0-'B20. Add 200 g of a green-emitting phosphor represented by . While stirring the phosphor suspension, adjust the pH to 8 to 9 with aqueous ammonia. Continue stirring in this state for 30 minutes. Thereafter, it is filtered and dried to obtain the phosphor of the present invention.

The contact charge amount of this phosphor and the conventional example is +1.5X10
-'' and -2,5X10-'c/g.

Furthermore, as in Example-1, a 4-watt fluorescent lamp FL-
As a result of manufacturing and evaluating phosphor No. 4, the phosphor of the present invention was ranked A, whereas the phosphor of the conventional example was ranked C-.

As described above, the green-emitting rare earth phosphor according to the present invention has no coloration phenomenon during lighting, has high luminous output, and is very stable in a high-load fluorescent lamp (0,055 V/c- or more). This provides lamp characteristics.

Next, FIG. 3 shows an example of a fluorescent lamp equipped with a fluorescent film made of the above-mentioned fluorescent material. Fluorescent lamps are as shown in the figure.
The bulb (1) has a fluorescent film (2) attached to its inner surface, and a discharge gas of a predetermined pressure is sealed inside the bulb (1), and electrodes are attached to both ends of the bulb (1). A predetermined voltage is applied to (3), and the fluorescent film (2) emits light due to the excitation source.

The present invention includes a fluorescent lamp including the above-described phosphor according to the present invention.

[Effects of the Invention] As explained above, according to the present invention, a high-load fluorescent lamp (0,055 V/c- or more) does not suffer from coloring during lighting, and therefore has high luminous output and lamp characteristics. A stable green-emitting phosphor and fluorescent lamp can be realized.

[Brief explanation of the drawing]

Figure 1 is a curve diagram showing the relationship between tube wall load of a fluorescent lamp and the degree of coloring phenomenon, Figure 2 is a curve diagram showing the relationship between contact electrification order and degree of coloring phenomenon, and Figure 3 is a curve diagram showing the relationship between the tube wall load of a fluorescent lamp and the degree of coloring phenomenon. FIG. 1 is a partially cross-sectional front view of an embodiment of a fluorescent lamp including a fluorescent film made of fluorescent material. (2)...Fluorescent film. Applicant's agent Patent attorney Takehiko Suzue Figure 3

Claims (2)

[Claims] (1) General formula activated with cerium and terbium (
Re_1_a_-_bTb_aCe_b)_2O_3・
eAl_2O_3・fSiO_2・gP_2O_5 (However, Re is at least one selected from yttrium (Y), lanthanum (La), and gadolinium (Gd), and a>0, b>0, 0<a+b<1, e≧ 0, f≧0
, g>0, 0.8≦e+f+g≦1.30), or (
Re_1_-_a_-_bTb_aCe_b)_2O_
3・xSiO_2・yP_2O_5・zB_2O_3(
However, Re is yttrium (Y), lanthanum (La),
At least one type selected from gadolinium (Gd) and a>0, b>0,0<a+b<1, x≧0,y>
0.5×10^-^6≦z≦6×10^-^3), and the pipe load is 0.055W/cm^2 or more,
The amount of contact charge on the surface of the phosphor per unit weight is a-Al_
2O_3 powder (particle size approximately 0.1 μm) and SiO_2 powder (
A phosphor characterized in that the particle size is between about 2.0 μm). (2) comprising a phosphor film made of the phosphor according to claim 1;
A fluorescent lamp characterized by a tube wall load of 0.055 W/cm^2 or more.