JPH01185389A - Phosphor and fluorescent lamp prepared from the same - Google Patents

Abstract

PURPOSE:To obtain a highly bright phosphor emitting blue light which gives a fluorescent lamp having high color rendering properties, high luminous flux efficiency, high color temp. and less occurrence of color shade, by mixing together compds. contg. ingredient elements of a desired substance in predetermined proportions, optionally followed by addition of a flux, and calcining it. CONSTITUTION:Oxides or precursor substances contg. ingredient elements of a desired substance are mixed together in predetermined element proportions, optionally followed by addition of a flux comprising a fluoride compd. which vaporizes at high temps., such as ZnF2. The mixture is calcined in a reducing atmosphere (e.g., in H2 or atmosphere of H2 + inert gas) at 1,000-1,500 deg.C, and pulverized. Optionally, a flux such as an alkali metal salt is added thereto and the mixture is and re-calcined in the aforesaid atmosphere at 1,000-1,500 deg.C. Thus, a phosphor of the formula (wherein M is Zn or Mg; Z is Ca, Sr, or Ba; 0<=x<=0.3; and 0.02<=y<=1.0) is obtd. This phosphor is mixed with a phosphor emitting red light and a phosphor emitting green light, and applied to a tube wall. As a result, a fluorescent lamp exhibiting a color temp. of 6,500K is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fluorescent material that emits light when excited by ultraviolet light and a fluorescent lamp using the same.

[Conventional technology]

Conventionally, a three-wavelength band type fluorescent lamp has been commercialized as a fluorescent lamp with good color rendering properties. This fluorescent lamp is coated with a mixture of phosphors of three emission colors: blue, red, and green, so that it can be excited by ultraviolet light to produce white light.

For example, as a blue-emitting phosphor (SrCaBaMg)0
．． (PO4), Cu2: Eu or (BaMg)□. (
pO4) 6ca2:EU, Y2O3:Eu is used as a red-emitting phosphor, and LaPO4:Tb, Ce, etc. are used as a green-emitting phosphor.

The mixing ratio of the three types of phosphors is determined so that a white color with a color temperature of 5000 K can be obtained using these phosphors. In that case, the average color rendering index (Ra) and luminous efficiency are almost determined, and R
A light beam with a value of about 84 and a luminous flux efficiency of 892 m/W has been obtained.

Recently, in the market, with the diversification of lighting, there has been a demand for fluorescent lamps with a higher color temperature (6500K) and Ra of 80 or more than the above-mentioned fluorescent lamps. When the color temperature is increased by changing the mixing ratio of the three types of phosphors, Ra decreases. So color temperature 6
To obtain a fluorescent lamp with Ra of 80 or more at 500 K,
In addition to the above three types of phosphors, as a fourth component, 480 to 4
A method has been considered in which a phosphor with a blue-green luminescent color having a peak wavelength around 90 nm is mixed. Such blue-green emitting phosphors include SrO・P2O5・B2O3:
Eu or 5r4Afl, 402. ': There are Eu etc. (
For example, the 212th Annual Conference on Fluorescent Materials Conference (September 19, 1986), pp. 21-23, etc.).

[Problem to be solved by the invention]

The above-mentioned conventional technology does not take into account the fact that the more types of fluorescent materials to be mixed, the more severe the conditions must be in order to uniformly mix many types of fluorescent materials during the manufacture of fluorescent lamps. In order to uniformly apply a mixture of many types of phosphors with different specific gravity and particle sizes, a uniformly mixed phosphor coating must be obtained. Further, industrially, such a paint must be stored for a certain period of time from mixing to application, and therefore it is necessary to prevent non-uniformity such as separation from progressing during that time. Therefore, as the number of types of phosphors increases, the phosphor film tends to become non-uniform, which causes the problem of color unevenness in the fluorescent lamp. Furthermore, since each phosphor has a different luminance life, there is also the problem that the color of the emitted light changes when the fluorescent lamp is used for a long time.

An object of the present invention is to provide a fluorescent lamp having a color temperature of about 6500 K, high color rendering properties, high luminous flux efficiency, and less likely to cause color unevenness, and a fluorescent material used therein.

[Means to solve the problem]

The above purpose is achieved by the general formula % (where M is at least one element selected from the group consisting of Zn and Mg, and Z is at least one element selected from the group consisting of Ca, Sr, and Ba). represents an element,
X is a value in the range of 0 x x 0.3, y is 0.02 < y x 1
．． 0) and a fluorescent lamp using this phosphor.

If the value of X exceeds 0.3, the above range of S
i.

Since another phase appears in addition to ○□9 and the brightness decreases, a value of 3 or less is preferable.

In addition, the range of y is 0.02 to 1.0 as in the conventional (S
rCaBaMg) □. (P O4) G C (12: E
It is preferable because it has higher brightness than the phosphor u (hereinafter abbreviated as SPC). In particular, it is more preferable for y to be in the range of 0.05 to 1.0 because the brightness is higher.

The above-mentioned phosphor can be manufactured, for example, by the following method. Oxides of the constituent elements of the above general formula excluding oxygen,
Compounds that can become oxides by heating, such as 5Zno
・2CO□・4H20, Eu2O3, A203, Si
n, etc., so as to have the element ratio excluding oxygen in the above general formula, and if necessary, add a fluoride that vaporizes at high temperature such as ZnF2 as a furanox, and add it in a reducing atmosphere, for example, H2.
In medium or mixed gas of H2 and inert gas, about 1000 ~
1' Bake at 500℃. The fired product is pulverized, a flux such as an alkali metal salt is added if necessary, and the fired product is fired again at about 1000 to 1500°C in the above atmosphere.

A fluorescent lamp using this phosphor can be obtained, for example, by using the above phosphor as a blue component, Y2O3:Eu as a red component, and L a P O4: T b , Ce as a green component.

[Effect]

M in the general formula:=Zn, x=O, that is, Zn2(x-y)Eu2yAI14Sj, 0
．． , , will be explained by taking a phosphor as an example. FIG. 1 shows the emission spectra of this phosphor when the value of y, that is, the Eu concentration was changed, upon excitation with 254 nm ultraviolet light. y is 0.03
The emission spectrum in this case has a peak wavelength of 453 nm and a spectral half width of 66 nm. This is wider than the half-width of about 30 nm of the conventional blue-emitting phosphor SPC.

Since the half-width is wide, the luminescent energy near 480 nm is strong, and the effect of raising the color temperature is great. Furthermore, as the Eu concentration increases, light emission having a peak around 52Qnm appears in addition to the main peak wavelength around 460nm. In this way, the two peak intensities can be changed by adjusting the Eu concentration. This is advantageous for obtaining a fluorescent lamp with a high color temperature from the phosphor of the present invention, a red-emitting phosphor, and a green-emitting phosphor.

〔Example〕

An embodiment of the present invention will be described below.

Examples 1 to 6 Eu203 0.01y mol A2
0. 0.02 mole 5iOz
(Colloidal silica) 0.05 mol ZnF2
(Flux) 0.006 mol The above formulation was mixed well, packed into a 15mM aluminum crucible, placed in an electric furnace, and heated in N2 containing 5% N2 (200mM).
Q /m1n) at 1200° C. for 2 hours.

The fired product was ground in an agate mortar, 0.0004 mol of 2So4 was added as a flux, and fired again under the same conditions as above. The fired product was washed with water to remove 2S04. Note that ZnF2 used as a flux evaporates during firing, so it does not remain in the sample. The emission characteristics of the thus obtained phosphors having different Eu concentrations (y) upon excitation at 254 nm are shown below. The brightness value is the phosphor s
The brightness of pC is expressed relative to 100.

FIG. 2 shows the relationship between Eu concentration (y) and relative brightness. y
The brightness is higher than SPc when the value is in the range of 0.02 to 1.0. Further, the brightness is higher when the value of y is in the range of 0.05 to 1.0.

This phosphor was mixed with a red-emitting phosphor and a green-emitting phosphor and applied to a fluorescent lamp, with a color temperature of 6500 K,
The fluorescent lamp can have an Ra of 80 or more and a luminous flux efficiency of 18 Qm/W or more.

Examples 7 to 10 M C0,0,002 mol (However, M = Mg, Ca, Sr, Ba)
E N2030.0007 mol Au, 030.02 mol 5in2 0.05 mol ZnF
After thoroughly mixing 20.006 mol of the above formulation, it was packed into a 15 mM aluminium crucible, and the rest was treated in the same manner as in Example 1. The emission characteristics of the thus obtained phosphor upon excitation at 254 nm are shown below.

The brightness value is expressed relative to the brightness of the phosphor spc as 100.

81 Examples 11-13 MgCO 30,002 mol M'C○ 30.001 mol (where M' = Ca, S r, B a) E N
2030.0007 mol 4 magazines 2030.02 mol 5un2 0.05 mol ZnF
After thoroughly mixing 20.006 mol of the above formulation, it was packed into a 15 m Q alumina crucible, and the rest was treated in the same manner as in Example 1. The emission characteristics of the thus obtained phosphor upon excitation at 254 nm are shown below.

Example 14 MgC 0,0,0186 mol Eu, 020.0007 mol M, 020.02 mol 5in2 0.05 mol ZnF
2 0.006 mol After thoroughly mixing the above-mentioned materials, they were packed into a 15+++Q aluminium crucible, and the rest was treated in the same manner as in Example 1. The emission characteristics of the phosphor thus obtained upon excitation at 254 nm are shown below.

The brightness value is expressed relative to the brightness of the phosphor SPC as 100.

Example 15 MgC0,0,0166 mole CaC0,0,002 mole E u2o, 0.0007
Mol Al120. 0.02
(-/l/Sin, 0.05
Mol ZnF, 0.006
After thoroughly mixing the above-mentioned materials, they were packed in an aluminium crucible of No. 51 Ilρ, and the rest was treated in the same manner as in Example 1. The emission characteristics of the phosphor thus obtained upon excitation at 254 nm are shown below. The brightness value is expressed relative to the brightness of the phosphor SPC as 100.

Note that phosphors obtained by using Sr or Ba in place of Ca had almost the same luminescent properties.

Example 16 Znz, 7Eul11.3AJSi50□, 37 parts by weight Y, O,: Eu 33 parts by weight LaPO4: Tb, Ce 30 parts by weight Low melting point glass 1 part by weight 1% polyethylene oxide aqueous solution 100 parts by weight Obtained in Example 1 The above mixture was prepared using a phosphor, and the mixture was ball milled for 30 minutes, poured into a glass tube, and dried with hot air at about 100° C. to form a uniform film surface (coating amount: 2.3 g). Then, through the process of firing, sealing, tube bending, and exhaust, the 28W
I made a fluorescent lamp (FCL30).

This fluorescent lamp had a color temperature of 6500, an Ra of 80, and a luminous flux efficiency of 81 Am/W. Moreover, the fluorescent film was homogeneous without color unevenness. In addition, 5rO-P.

0, ・B2O3: Eu22g, (S r, Ca,
B a, Mg) □.

(PO,)r, CA2: Eu23g, LaP
O4: Tb, Ce27g and Y2O3: Eu2gg
A conventional fluorescent lamp manufactured using a mixture of There was something.

[Effect 3 of the Invention According to the present invention, a high-intensity blue-emitting phosphor could be obtained. Furthermore, a fluorescent lamp used in combination with this phosphor, a red-emitting phosphor, and a green-emitting phosphor has a color temperature of 65.
00 K, showing high color rendering properties and high luminous flux efficiency.

[Brief explanation of the drawing]

The first is Z n,, (□-y) with different Eu concentrations (y).
'E u2yAll. 5isOte phosphor 254n
A diagram showing the emission spectrum due to m excitation, Figure 2 is 254
Z n2 (ty) E u2 yA by nm excitation
I14 S ig 01 Eu concentration of Il phosphor (y)
FIG. 3 is a diagram showing the relationship between and relative brightness. Representative Patent Attorney Junnosuke Nakamura (Procedural Amendments) May 6, 1985 Director General of the Patent Office Kunio Ogawa 1, Indication of Case Patent Application No. 9568, 1988 2
, Title of the invention Fluorescent material and fluorescent lamp using the same 3, Person making the amendment - Relationship to the case Name of patent applicant
(510) Hitachi, Ltd. 5, date of amendment order
April 26, 1986 6, Subject of amendment: Brief explanation column of drawings in the specification.\-

Claims (3)

[Claims] 1. General formula (M_1_-_x_-_yZ_xEu_y)_2Al_
4Si_5O_1_8 (However, M is at least one element selected from the group consisting of Zn and Mg, Z is Ca, S
It represents at least one element selected from the group consisting of r and Ba, x is a value in the range of 0≦x≦0.3, and y is 0.
02≦y≦1.0). 2. 2. The phosphor according to claim 1, wherein M in the general formula is at least Zn. 3. General formula (M_1_-_x_-_yZ_xEu_y)_2Al_
4Si_5O_1_8 (However, M is at least one element selected from the group consisting of Zn and Mg, Z is Ca, S
It represents at least one element selected from the group consisting of r and Ba, x is a value in the range of 0≦x≦0.3, and y is 0.
A fluorescent lamp comprising a phosphor having a value in the range of 02≦y≦1.0, a red-emitting phosphor, and a green-emitting phosphor on a tube wall.