JPS62187785A - Highly color-rendering fluorescent lamp - Google Patents

Abstract

PURPOSE:To improve the brightness of a fluorescent screen and to prevent its deterioration, by controlling the composition and the particle size of a red light emitting phosphor among the components of a fluorescent screen for a highly color-rendering fluorescent lamp to specified values. CONSTITUTION:15-45wt% red light emitting phosphor (A) having a particle size of 2-4mu, composed of a phosphor having a composition represented by the formula (wherein 0.25<=x<0.98; 0.01<y<=0.1; x+y<=1) is mixed with 30-65wt% green light emitting phosphor (B) selected from the group consisting of phosphors represented by the formulas LaPO4: Ce, Tb, n.MIIO.B2O3:Ce, Tb (wherein MII is Mg or Zn; and 0<n<=2) and (Ce, Tb) MIIAl11O19 and 15-35wt% blue light emitting phosphor (C) selected from the group consisting of Ca2B5O9Cl:Eu<2+>, BaMg2Al16O27:Eu<2+> and aMII3(PO4)2: bMIICl2:Eu<2+> (wherein MII is Ca, Sr or Ba; and 1<=a/b<=3). The resulting phosphor mixture compsn. is used as a fluorescent screen to prepare the titled fluorescent lamp.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high color rendering fluorescent lamp. More specifically, the present invention relates to a high color rendering fluorescent lamp in which the white luminous flux is improved by strictly controlling the composition and particle size of the red-emitting phosphor, which is one of the constituent components of the fluorescent film.

The fluorescent film of a high color rendering lamp is made of a luminescent composition that is a mixture of blue, green, and red emitting phosphors.The reason why such a luminescent composition is used as the fluorescent film of a high color rendering fluorescent lamp is as follows. This is because by mixing blue, green, and red emitting phosphors, the color rendering index can be increased without lowering the viewing efficiency.

Blue, green and red emitting phosphors used as fluorescent films in high color rendering lamps are required to have the following characteristics.

i) 430nm to 490nm for blue emitting phosphors
nm, preferably around 450 nm, and 510 nm to 570 nm for green emitting phosphors.

Preferably around 540 nm, and for red emitting phosphors from 590 nm to 630 nm, preferably 610 nm.
The peak wavelength of the emission spectrum should be around nm.

ii) Emission brightness is high, especially green light-emitting phosphors have high emission brightness because their emission color matches visibility.

iii) Emission brightness does not change (decrease) over time, that is, there is little deterioration.

The fluorescent film of high color rendering fluorescent lamps currently in practical use uses europium-activated yttrium oxide phosphor (
Y2O3:Eu) is used.

In addition, as a blue-emitting phosphor, a divalent europium-activated barium magnesium aluminate phosphor (BaMg, 81
+aOzCEu'') and divalent europium activated strontium calcium halophosphate group amount 1 ((Sr+Ca)s
(POa)zcl:Hu”) is used, and cerium and terbium-activated lanthanum phosphate phosphor (LaPOn: CeTb) and terbium-activated magnesium cerium aluminate phosphor ((CeTb) are used as green-emitting phosphors.
e, Tb) MgA1zO+v) is used.

However, many of these phosphors are relatively expensive, so it is desired to reduce the amount of these phosphors used as much as possible to increase the luminous flux (as white) of the entire phosphor film. ing. Furthermore, blue-emitting phosphors and green-emitting phosphors have worse deterioration characteristics than red-emitting phosphors, and improvements in their characteristics are required.

The present invention replaces at least a portion of the yttrium in the europium-activated yttrium oxide red light-emitting phosphor (YzOz:Eu), which has been conventionally used as the fluorescent film of high color rendering fluorescent lamps, to improve the red brightness and reduce the particle size. By controlling the diameter, we can take full advantage of the good deterioration characteristics of this red-emitting phosphor, increase the luminous flux of the entire phosphor film (as a white color), and improve the deterioration characteristics of the lamp. The purpose is to provide a lamp.

In order to solve the above-mentioned problems, the present inventors conducted a detailed study on the relationship between the composition and particle size of red-emitting phosphors used in high color rendering fluorescent lamps and lamp luminous flux, and found that Y, O, : For nu, a particle size of about 4 to 5 μm is optimal, and although a particle size smaller than that causes a decrease in brightness, at least a part of Y in Y2O3:Eu is replaced by Gd.
(Y+-X-yGdXEuy) zO:
+ When using phosphor, particles smaller than 4μ, i.e. 2
It was found that even when a coating with a thickness of ~4μ was used, no reduction in brightness occurred, and high brightness characteristics were exhibited even if the coating weight was lower than that of the currently used Y, O, :Eu.

In addition, by making the red-emitting phosphor into small particles, it is thought that a coating film is formed that covers the blue-emitting phosphor and the green-emitting phosphor within the phosphor film, and this improves the deterioration characteristics of the phosphor film. We have discovered that it is possible to do this, and have arrived at the present invention.

The high color rendering fluorescent lamp of the present invention has the following characteristics: a) The compositional formula is (Y+-, I-yGd-Euy)zOi
(However, and y are respectively 0.25≦x<9.98
．． This number satisfies the conditions of 0.01≦3'≦0.1 and x+y≦1. b) 15 to 45% by weight of a red light-emitting phosphor which is a europium-activated yttrium gadolinium oxide phosphor represented by (the same applies hereinafter) and whose particle size is in the range of 2 to 4μ; b) cerium and terbium-activated phosphor; Lanthanum acid phosphor (LaPO4:Ce, Tb), composition formula is nM I
f O・Bz03:CeTb (However, MII is at least one of magnesium and zinc, and n is O≦n≦
This is a number that satisfies the condition of 2.0. ) and terbium-activated alkaline earth metal cerium aluminate phosphor whose composition formula is (CeTb)MIIAl++O+q (where MII has the same definition as above). at least one type of green-emitting phosphor 30-6
0 weight percent, and C) divalent europium-activated chloro 5111M calcium-based phosphor (Ca, B, 0.C1:Eu2+),
Divalent europium-activated barium magnesium aluminate phosphor (BaM5tAlt60zt ・Eu”
) and the composition formula is aMII, (FO4)zb-MII
'C13: Divalent europium represented by Eu2+ (where Mll is at least one of calcium, strontium, and barium, and a and b are numbers satisfying the condition 1≦a/b≦゛3) A phosphor film is characterized in that a mixed luminescent composition comprising 15 to 35% by weight of a blue-emitting phosphor, which is at least one kind of activated alkaline earth metal halophosphate phosphor, is used as a phosphor film.

The present invention will be explained in detail below.

In the present invention, it is used as a red-emitting phosphor (Y+
-++-yGd++Euy)20:+The phosphor is manufactured by the manufacturing method described below.

As a raw material for the phosphor, yttrium oxide (Y2O2),
Yttrium, gadolinium, and europium compounds that can be easily converted into various oxides at high temperatures, such as gadolinium oxide (GdzO:+) and europium oxide (Euz03), or nitrates, oxalates, and chlorides of Y, Gd, and Eu, are used. The above three phosphor raw materials are stoichiometrically (
Y+-8-yGdxIluy) 203 (X and y are each 0.25≦x <0.98.0.01≦y
This is a number that satisfies the conditions of ≦0.1 and x+y≦1. ) Weigh and mix thoroughly so that the composition formula is as follows.

The mixing may be carried out in a dry manner using a ball mill, mixer mill, mortar, etc., or may be carried out in a wet manner such as in a paste state using water or an organic solvent as a medium, or by co-precipitation with oxalate or the like.

In addition, in the production of phosphors, fluxing agents are often added to the phosphor raw materials for the purpose of improving the luminance brightness, powder characteristics (particularly in this case, the fibers), etc. of the phosphor obtained. , boron oxide (BzO*) is also used in the production of this phosphor.
By adding and mixing an appropriate amount of barium chloride (BaCl) or the like as a flux into the phosphor raw material mixture, it is possible to improve the luminance of light emission and the powder properties.

Next, the phosphor raw material mixture is filled into a heat-resistant container such as an aluminium crucible or a quartz crucible, and fired.

Note that when the phosphor raw materials are wet mixed, the phosphor raw material mixture is dried in advance. Firing is performed several times in the air.

The firing temperature is 130 if the composition ratio is close to YzOz:Eu.
It is carried out at a high temperature of 0 to 1600°C, or if the composition ratio is close to GdzOi, it is carried out at a high temperature of 1050 to 1300°C.

The firing time varies depending on the filling amount, firing temperature, etc., but within the above firing temperature range, it is appropriate for 0.5 to 6 hours, more preferably 1 to 5 hours.

After firing, a phosphor is obtained by performing washing, dispersion, classification, drying, and various operations generally employed in the production of subdivided phosphors.

Figure 1 shows the fluorescent films used in the high color rendering fluorescent lamp of the present invention (Yo, Z@+ Gdo, ?ff+ Euo,
03) zoa phosphor (curve a) and exemplified as a comparative example (Yo, 96. ELIo, 04) t
The figure shows the relationship between the emission intensity (relative value) and the particle size of each phosphor used for each monochromatic fluorescent lamp using 's phosphor (curve b). As is clear from Figure 1, it has traditionally been used as a red-emitting phosphor in high color rendering fluorescent lamps (Yo, qb, Euo, o4) z
oz, the emission intensity gradually decreases when the particle size becomes smaller than 4μ, whereas the fluorescent lamps used in the high color rendering fluorescent lamp of the present invention (Yo, go, Gdo, 7.Eu
o, os) z03 has higher emission intensity than conventional red-emitting phosphors up to about 2μ. In addition, the particle size of the phosphor used is 5 to 6 meters! If it is more than that, the coating film transmittance of the obtained fluorescent film will decrease and the maximum luminous flux as a fluorescent lamp will not be obtained, which is not preferable. Also (Y+-x-yGdJLIy
Since lzoz has a higher specific gravity than the conventionally used YzO:+:Eu, the larger the particles used, the higher the Y2
In order to obtain a fluorescent film with a light transmittance comparable to that of O3:Eu, the coating weight increases, which is undesirable and increases the cost.
I-, -, Gd, Euy) 2off is 2 to 4 in order to make the coating as thin as possible and obtain more luminous flux than the conventional one.
It is preferable to use particles with a particle size of μ.

Figure 2 shows Yl-11-11, osGdgEu, which is used as a red-emitting phosphor in the high color rendering fluorescent lamp of the present invention.
o, os)t.

This figure shows the relationship between the amount of Gd in solid solution (x) and the emission intensity of the obtained phosphor.

As is clear from Figure 2, when the solid solution 1(x) of Gd is larger than approximately 0.25, the luminescence intensity is lower than that of Y2O3:Eu, which has been conventionally used as a red-emitting phosphor in high color rendering fluorescent lamps. expensive.

On the other hand, the concentration (y) of europium (Eu) as an activator is
Almost the same as in the case of Y2O3:Eu, the emission intensity is 0.
It is practically preferable that the range is 01≦y≦0.1. Produced as described above (Y, -11-ycdxau
y)! The o3 phosphor is superior to the conventional YzOz:Eu phosphor as a red-emitting phosphor for the phosphor film of a high color rendering fluorescent lamp. The luminescent composition used as the fluorescent film of the high color rendering fluorescent lamp of the present invention comprises the above-mentioned (y,□□cdxEuy) tos red-emitting phosphor, green-emitting phosphor, and blue-emitting phosphor having a specific particle size. Prepared by mixing predetermined amounts.

The green-emitting phosphor used in the high color rendering fluorescent lamp of the present invention is a cerium- and terbium-activated lanthanum phosphate phosphor (LaPOa:Ce,Tb) whose composition formula is nM U O BgOs:CeTb (however, MII is at least one of magnesium and zinc, and n is 0
The number satisfies the condition ≦n≦2.0. ) and the composition formula is (Ce, Tb)MIIA1zO+
A green emitting phosphor is used which is at least one of the terbium-activated alkaline earth metal cerium aluminate phosphors represented by q (where MU has the same definition as above). The blue-emitting phosphor is the same (conventionally known divalent europium-activated male chloroborate phosphor (CaJsOqCl:Eu'')).

Divalent europium-activated barium magnesium aluminate phosphor (BaMgJl 1 bott:Eu” and compositional formula aMIIz(PO4)z HbMIIc1
3: Eu2+ (where MII is at least one of calcium, strontium, and barium, and a and b are numbers that satisfy the condition 1≦a/b≦3.0)
A blue-emitting phosphor that is at least one type of divalent europium-activated alkaline earth metal halophosphate phosphor represented by is used.

The red, green and blue emitting phosphors each account for 15 to 45% by weight of the total amount of the resulting luminescent composition.

They are mixed in amounts of 30-65% by weight and 15-3.5% by weight. If the mixed amounts of the red, green and blue light emitting phosphors are not within the above range, a high color rendering index and high luminous flux cannot be obtained.

Approximately 4,000 to 6
Desired fluorescent lamps with color temperatures within the range of 500'K can be obtained.

The high color rendering fluorescent lamp of the present invention is manufactured in the same manner as conventional lamps, except that the novel luminescent composition described above is used as a fluorescent film.

Next, the present invention will be explained by examples.

Example 1 3.2μ of (Yo, +Gdo, I?:l 11!-
u@, 02? ) tOz phosphor 40% by weight, LaPO4
:Ce4b phosphor 40! i-1% and BaMgzAI
A 30 W fluorescent lamp having a phosphor film made of a mixed luminescent composition containing 20% by weight of +hOzt:Eu'' phosphor was manufactured by a conventional method.

The color rendering index of the obtained fluorescent lamp was 84, and the luminous efficiency was 7.
3j! s+/W, (Yo, +Gdo, etc Euo, ozt) z
(h Instead of phosphor, use 4μ of (Yo, 96ELlO,o
a) It showed a luminous flux higher than the luminous efficiency (701! m/W) of a fluorescent lamp made in the same manner as above except for using zOs phosphor, and the luminance decreased when operated for a long time (
(deterioration of the fluorescent film) was also improved.

Example 2 2.5μ (Y6.5Gd6.467 Buo, o:
++) zOx phosphor 40% by weight, (Ce, Tb)Mg
A1zO+v phosphor 40% by weight and BaMg2Af,
A 30 W fluorescent lamp having a fluorescent film made of a mixed luminescent composition containing 20% by weight of 60.7:Eu'' phosphor was manufactured by a conventional method.

The color rendering index of the obtained fluorescent lamp was 84, and the luminous efficiency was 7.
1 j! m/W, (Yo, 5Gdo, 41,7 Euo, o:++
) 4μ (Yo, q,,Eu) instead of 203 phosphor
o. 4) Luminous efficiency (69 Am/W) of a fluorescent lamp made in the same manner as above except for using z(h phosphor)
It exhibits a higher luminous flux, and the decrease in brightness (deterioration of the fluorescent film) when operated for a long time has been improved.

Example 3 2.4μ of (Yo, zGdo, '?'?JuO,o
va) zoz phosphor 32% by weight, (La, B) P
EXAMPLE 1 A 30 W fluorescent lamp having a fluorescent film made of a mixed luminescent composition consisting of 40% by weight of O,:Ce,Tb+Li phosphor and 28% by weight of CaJ504C1:Eu'' phosphor was manufactured by a conventional method.

The color rendering index of the obtained fluorescent lamp was 82, and the luminous efficiency was 7.
2j! m/W (Yo, zGdo, , tzEu
o, oza) 4μ (Yo, oza) instead of zo3 phosphor
qhEuo, 04) Luminous efficiency (6
81f/W), and the reduction in brightness (deterioration of the fluorescent film) when operated for a long time was also improved.

Example 4 3.0 μ of (Gdo, qrsEuo, ozs)z(h
Phosphor 35%, 0.33Mg0 ・BzO:+:C
e, Tb phosphor 45% and (Sr,Ca)s(P
A 30 W fluorescent lamp having a phosphor film made of a mixed luminescent composition consisting of 20% by weight of Oa)*Ce:Eu'' phosphor was manufactured by a conventional method.

The color rendering index of the obtained fluorescent lamp was 84, and the luminous efficiency was 7.
21m/W (Gdo, 9?5Eu0.025
> 4μ (Yo, qJuo,
04) Luminous efficiency of a fluorescent lamp produced in the same manner as above except for using zQz phosphor (70j2m/W)
It exhibits higher luminous flux, and the reduction in brightness (deterioration of the fluorescent film) during long-term operation has also been improved.

As detailed above, replacing at least a part of Y in YzOl:Eu with Gd increases the red luminescence intensity, and the luminescence intensity decreases less even if it is crushed more finely than Y2O3:Hu. Compared to conventional high color rendering fluorescent lamps using YzO*:Eu, by using a small-sized phosphor ((Y+--yGdXEuy)zOi) as a red-emitting phosphor in the fluorescent film of a high color rendering fluorescent lamp. It has high brightness and can reduce the coating weight to obtain the same emission intensity, and also suppresses deterioration of the fluorescent film compared to conventional high color rendering fluorescent lamps using Y2O,:ELI.

[Brief explanation of drawings]

Figure 1 shows the relationship between the particle size of red-emitting phosphors used in the high color rendering fluorescent lamp of the present invention and conventional high color rendering fluorescent lamps, and the relative emission intensity of a monochromatic lamp using these alone as a fluorescent film. This is a graph showing. Figure 2 shows the relationship between Gd1l(x) in the red-emitting phosphor (Yl-X-yGd xEuy) zo:+ used in the high color rendering fluorescent lamp of the present invention and the relative emission intensity of these phosphors. This is a graph showing. Patent applicant Kasei Obtonics Co., Ltd. Drawing engraving (
(No change in content) (OJ) Procedural amendment March 17, 1985 Michibe Uga, Commissioner of the Patent Office1, Indication of IG Patent Application No. 1989-289312, Title of invention: High color rendering fluorescent lamp 3. Relationship with the case of the person making the amendment Patent applicant name Name Kasei Optonics Co., Ltd. 4 Agent address 40 Mori Building, Toranomon, 5-13-1 Toranomon, Minato-ku, Tokyo Name (6538) Patent attorney, Yamashita
穣 ♀°°Hot 5, subject to correction
゛----2' Description, drawings and power of attorney 6, contents of amendment -1. As per the attached sheet・Y／＼′

Claims (1)

[Claims] 1)a) The compositional formula is (Y_1_-_x_-_yGd_xE
u_y)_20_3 (however, x and y are each 0.
25≦x<0.98, 0.01≦y≦0.1 and x+
15 to 45% by weight of a red light-emitting phosphor which is a europium-activated yttrium oxide gadolinium phosphor represented by y≦1 (a number satisfying the condition y≦1) and whose particle size is in the range of 2 to 4 μm. b) Cerium-terbium-activated lanthanum phosphate phosphor (LaPO_4:Ce, Tb), compositional formula n MIIO B_2O_3:Ce, Tb (however, MI
I is at least one of magnesium and zinc, and n is a number satisfying the condition 0<n≦2.0) Cerium- and terbium-activated alkaline earth metal borate-based phosphor and composition The formula is (Ce,Tb)MIIAl
30-65% by weight of a green-emitting phosphor that is at least one of the terbium-activated alkaline earth metal cerium aluminate phosphors represented by _1_1O_1_9 (where MII has the same definition as above); and C) Divalent europium activated calcium chloroborate phosphor (Ca_2B_5O_9Cl:Eu^
2^+), divalent europium activated barium magnesium aluminate phosphor (BaMg_2Al_1_6
O_2_7:Eu^2^+), and the composition formula is aMII_
3(PO_4)_2:bMIICl_2:Eu^2^+
(However, MII is at least one of calcium, strontium, and barium, and a and b are 1≦a
Blue-emitting phosphor 15 to 35 which is at least one type of divalent europium-activated alkaline earth metal halophosphate phosphor represented by /b≦3)
A fluorescent lamp with high color rendering properties, characterized in that a fluorescent film is a mixed light-emitting composition consisting of % by weight.