JPS628470B2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to improvements in fluorescent lamps.

One way to improve the color rendering method without sacrificing the efficiency of fluorescent lamps is to use three types of fluorescent lamps whose emission spectra have peak wavelengths around 450 nm, 540 nm, and 610 nm, respectively, and whose emission spectra have relatively narrow half-widths. A so-called three-wavelength method using the body is known. In this three-wavelength system, the blue-emitting phosphors whose emission spectrum peak wavelength is around 450 nm are divalent europium-activated strontium/calcium halophosphate phosphors, and divalent europium-activated halostrontium phosphate phosphors. , divalent europium-activated barium/magnesium aluminate phosphor, cerium and terbium co-activated yttrium silicate phosphor, cerium and terbium co-activated aluminium as a green-emitting phosphor with an emission peak wavelength around 540 nm. magnesium acid phosphor, terbium-activated yttrium silicate phosphor, terbium-activated lanthanum phosphate/gadolinium phosphor, cerium and terbium co-activated lanthanum phosphate phosphor, and terbium-activated gadolinium oxysulfide phosphor. Furthermore, the peak wavelength of the emission spectrum
A europium-activated yttrium oxide phosphor is used as a red-emitting phosphor near 610 nm.

Among blue-emitting phosphors, divalent europium-activated strontium/calcium halophosphate phosphors have peak wavelengths closer to 450 nm and higher luminous efficiency than divalent europium-activated strontium halophosphate phosphors. It is superior to divalent europium-activated barium/magnesium aluminate phosphor in that it has a peak wavelength closer to 450 nm and is cheaper, although the luminous efficiency is comparable. For this reason, divalent europium-activated strontium/calcium halophosphate phosphors are widely used as blue-emitting phosphors.

However, when considering the balance between the efficiencies of blue, green, and red light-emitting phosphors, the efficiency of this blue-emitting phosphor is lower than that of other phosphors, and improvement thereof is desired.

This invention was accomplished by obtaining a blue-emitting phosphor with particularly improved luminous efficiency. The general formula of this phosphor is x(M _1-p・Eup・O)・yP ₂ O ₅・
aM′X ₂・bB ₂ O ₃ (However, M and M′ are at least one of strontium, calcium, and barium;
X is at least one of chlorine, fluorine, and bromine, 2.7≦
x≦3.3, 0.50≦y≦1.5, 0.10≦a≦0.50, 0.01≦
b≦0.50, 0.001≦p≦0.20) divalent europium-activated haloborophosphate blue-emitting phosphor (hereinafter referred to as haloborophosphate phosphor),
A patent application was filed earlier. Compared to the 100% luminous efficiency of the divalent europium-activated strontium/calcium halophosphate phosphor, the luminous efficiency of this haloborophosphate phosphor is at most 130%, significantly improving efficiency.

The peak wavelength of the emission spectrum of this haloborophosphate phosphor is around 450 nm. When this phosphor was applied to the three-wavelength method described above, the general formula was (Ln・Tb) ₂ O ₂ S (where Ln is at least one of yttrium, lanthanum, gadolinium, cerium, lutetium, and samarium). A terbium-activated rare earth phosphor with the general formula (Ln・Tb)PO ₄ (where Ln is at least one of yttrium, lanthanum, gadolinium, cerium, lutetium, and samarium). Phosphate phosphor, a cerium and terbium coactivated rare earth phosphate phosphor whose general formula is (Ln・Ce・Tb)PO ₄ (where Ln is at least one of yttrium, gadolinium, lanthanum, lutetium, and samarium) The general formula is (Ln・Eu) ₂ O ₃ (Ln is yttrium,
When a fluorescent lamp tube is The inventors have discovered that the invention is effective in improving edge blackening, and have come to provide this invention.

That is, in this invention, (1) the general formula is x(M _1-p・
Eup・O)・yP ₂ O ₅・aM′X ₂・bB ₂ O ₃ (However, M and M′ are at least one of strontium, calcium, and barium, X is at least one of chlorine, fluorine, and bromine, 2.7≦x ≦3.3, 0.50≦y≦1.5,
0.10≦a≦0.50, 0.01≦b≦0.50, 0.001≦p≦
0.2) A divalent europium-activated haloborophosphate blue-emitting phosphor with the general formula (Ln.
Tb) Terbium-activated rare earth oxysulfide green light-emitting phosphor represented by ₂ O ₂ S (Ln is at least one of yttrium, lanthanum, gadolinium, cerium, lutetium, and samarium), whose general formula is (Ln・Tb) Terbium-activated rare earth phosphate green light-emitting phosphor represented by PO ₄ (where Ln is at least one of yttrium, lanthanum, gadolinium, cerium, lutetium, and samarium);
Or the general formula is (Ln・Ce・Tb)PO ₄ (However,
Ln is at least one of yttrium, gadolinium, lanthanum, lutetium, and samarium)
A green-emitting phosphor which is at least one type of cerium and terbium co-activated rare earth phosphate green-emitting phosphor represented by the formula (Ln・Eu) ₂ O ₃
(However, Ln is at least one of yttrium, lanthanum, gadolinium, cerium, terbium, and samarium) A fluorescent lamp equipped with a fluorescent film body consisting of a europium-activated rare earth oxide red-emitting phosphor, or ( 2) The phosphor film is composed of 100% by weight, 5-45% by weight of blue-emitting phosphor, 20-70% by weight of green-emitting phosphor, and 10-60% by weight of red-emitting phosphor. The fluorescent lamp described in item (1) above is a type of fluorescent lamp.

The fluorescent lamp of the present invention has been improved in terms of luminous efficiency and tube edge blackening of the three-wavelength type fluorescent lamp, and has been made at a low cost.

Tube end blackening refers to a so-called blackening phenomenon in which the tube end of a fluorescent lamp becomes black during lighting, and when this phenomenon occurs, the appearance of the lamp is significantly impaired and its commercial value is significantly reduced. Tube end blackening is thought to be caused by a chemical reaction that occurs between the phosphor, substances scattered from the cathode, impure gas in the tube, mercury, etc. under the activated state of discharge. Although the degree of occurrence varies depending on the type of phosphor, cathode material, and impure gas in the tube, the generation position is always a fixed position near the electrode.

To evaluate this tube end blackening, cut out a certain area including the glass and fluorescent film at the position where the blackening occurs.
What is necessary is to measure the visible light transmittance of glass and fluorescent film. As the degree of tube end blackening progresses, the visible light transmittance decreases. The visible light transmittance, which indicates the degree of tube end blackening, was measured for the 40 Watt fluorescent lamp of the present invention equipped with such a fluorescent film, and the blue-emitting phosphor was replaced with divalent europium-activated halophosphoric acid. A comparison was made with a comparative fluorescent lamp that was changed to strontium and calcium phosphors. In this case, the visible light transmittance of the comparative example fluorescent lamp is 100%, while the visible light transmittance of the fluorescent lamp of the present invention is 185%, and the degree of blackening is 85% of the comparative example lamp. It has been reduced by that amount. However, in order to measure the blackening at the end of the tube by lighting it for a relatively short period of time to simulate the blackening caused by lighting it for a long period of time, the fluorescent lamps of the Examples and Comparative Examples were measured at 130% of the rated load of the 40 Watt fluorescent lamp. under high load conditions
This was done after 1500 hours of lighting. A sample piece was cut out from the area where blackening occurred at the tube end, that is, from 30 mm from the end of the lamp light emitting part to 45 mm from the end, and was 15 mm long and 15 mm wide.The visible light transmittance was measured using a Beckman transmittance meter. be.

The performance of a three-wavelength fluorescent lamp that is suitable for practical use as a high color rendering fluorescent lamp is generally determined by an average color rendering index (Ra) of 80 or more and a lamp efficiency of 80 lm/W or more. In order to satisfy this performance, the ratio of the blue-emitting phosphor, green-emitting phosphor, and red-emitting phosphor is 100% by weight, 5 to 45% by weight of the blue-emitting phosphor, and 5-45% by weight of the green-emitting phosphor. 20～
70% by weight and 10-60% by weight of red-emitting phosphor.

Hereinafter, the present invention will be explained in more detail with reference to an example fluorescent lamp.

Example 1 SrCo ₃ 2.94 mol, Eu ₂ O ₃ 0.03 mol,
(NH ₄ ) ₂ TPO ₄ 1.84 mol, CaCl ₂ 1.2 mol,
Accurately weigh 0.16 mol of H ₃ BO ₃ and mix in a ball mill. This mixture was placed in a quartz crucible under a reducing atmosphere consisting of 95% nitrogen and 5% hydrogen by volume.
Bake at 1100℃ for 2 hours. After cooling the fired product, it is immersed in pure water and ground in a ball mill. Further, it is washed with pure water to remove excess CaCl ₂ and then dried. The dried material was placed in a quartz crucible under the reducing atmosphere.
Recalcined at 1100°C for 2 hours, cooled, crushed, and sieved. _{Chemical analysis of the phosphor thus obtained revealed that the general formula was 3.0 (Sr 0.98 Eu 0.02 O ) .}
It was confirmed that it was a blue-emitting phosphor represented by 0.92P ₂ O ₅ .0.33CaCl ₂ .0.08B ₂ O ₃ . Hereinafter, this fluorescent material will be referred to as fluorescent material A, and will be used in the fluorescent lamp of this example.

The excitation spectrum of phosphor A is shown at A' in FIG. 3Sr _3.0 (PO ₄ ) ₂ for comparative lamps _.
The excitation spectrum is shown at L' in FIG. 1, where L is a divalent europium-activated strontium calcium halophosphate phosphor represented by CaCl ₂ :0.02Eu. Both A' and L' are normalized to the highest excitation efficiency of 100%. In FIG. 1, the excitation efficiency of A' at an excitation wavelength of 254 nm is 80%, showing a significant improvement in excitation efficiency compared to 45.5% for L'.

The emission spectrum distribution of phosphor A is shown in FIG. It exhibits narrow band emission with a peak wavelength of 452 nm, making it suitable for use as a three-wavelength blue phosphor.

16% by weight _of phosphor A as a blue-emitting phosphor and 16% by weight of phosphor A as a green-emitting phosphor ₍ La _{0.09 Gd 0.01 Ce 0.70} Tb _{0.2 )}
64% by weight of cerium and terbium co-activated lanthanum-gadolinium phosphate phosphor, denoted by _PO4 ;
The 40 Watt 5000K white fluorescent lamp of this example was prepared in accordance with conventional methods using 20% by weight of (Y ₀ . ₉₅ Eu ₀ . ₀₅ ) ₂ O ₃ europium activated yttrium oxide phosphor as the red-emitting phosphor. Created and measured visible light transmittance after lighting for 1500 hours. In addition, as a comparative example fluorescent lamp, the blue-emitting phosphor was replaced with a divalent europium-activated strontium/calcium halophosphate phosphor L, and a cerium and terbium co-activated lanthanum/gadolinium phosphate green-emitting phosphor was used, activated with europium. 40 using the same yttrium oxide red-emitting phosphor.
A Watts 5000K white fluorescent lamp is used.

The emission spectrum distribution of this example fluorescent lamp at the initial stage of lighting is as shown in FIG. The visible light transmittance of the fluorescent lamp of this example was 135% compared to 100% of the fluorescent lamp of the comparative example, which is a 35% improvement. In addition, the average color rendering index (Ra) at the initial stage of lighting is 84, and the lamp efficiency (lm/W) is 83lm/
Indicates the value of W.

Example 2 SrCo ₃・2.773 mol, CaCo ₃ 0.0885 mol,
Eu ₂ O ₃ 0.0443 mol, (NH ₄ ) ₂ HPO ₄ 1.90 mol,
1.1 mol of CaCl ₂ and 0.18 mol of H ₃ BO ₃ were accurately weighed and mixed in a ball mill. Hereinafter, in the same manner as in _{Example 1, the general formula is 2.95(Sr 0.94 ・Ca 0.03 ・ Eu 0.03 ・}O)・
A blue-emitting phosphor represented by 0.95P ₂ O ₅ .0.30CaCl ₃ .0.09B ₂ O ₃ is obtained. Hereafter, this phosphor will be referred to as phosphor B.
, and is used as a blue-emitting phosphor in the fluorescent lamp of this example. This phosphor B was 12% by weight as a green-emitting phosphor (La ₀ . ₂ Ce ₀ . ₇₀ Tb ₀ . ₁ ).
66% by weight of cerium and terbium co-activated lanthanum phosphate phosphor denoted by PO ₄ and europium activation denoted by (Y ₀ . ₈₉₅ Tb ₀ . ₀₀₅ Eu ₀ . ₁ ) ₂ O ₃ as a red-emitting phosphor. Using terbium yztrium oxide phosphor 22% by weight, 40 watts according to conventional method.
A 4200K white fluorescent lamp was made and the visible light transmittance was measured after being lit for 1500 hours. In addition, the phosphor L used in the comparative lamp of Example 1 was used as the blue-emitting phosphor, and the phosphor made of the same material as in this example lamp was used as the green and red color-emitting phosphor. 40
A Watts 4200K white fluorescent lamp is used as a comparative example lamp.

The visible light transmittance of the fluorescent lamp of this example was 130% compared to 100% of the fluorescent lamp of the comparative example, which is an improvement of 30%. In addition, the average color rendering index (Ra) at the initial stage of lighting is 84, and the lamp efficiency (lm/W) is 84l.
Indicates the value of m/W.

Example 3 SrCo ₃ 2.928 mol, BaCo ₃ 0.061 mol,
Eu ₂ O ₃ 0.0305 mol, (NH ₄ ) ₂ HPO ₄ 1.70 mol,
1.134 mol of CaCl ₂ , 0.126 mol of SrCl ₂ , and 0.24 mol of H ₃ BO ₃ are accurately weighed and mixed in a ball mill. Hereinafter _, in the same manner as in _{Example 1, the general formula is 3.05 (Sr 0.96 ・}Ba _0.02・
Eu _{0.02 ・ O} )・_0.85P2O5・_0.35 (Ca _0.90・_{Sr 0.1 )}
A phosphor represented by Cl ₂ .0.12B ₂ O ₃ is obtained. Hereinafter, this phosphor will be referred to as phosphor C, and will be used as a blue-emitting phosphor in the fluorescent lamp of this example. 6% by weight of this phosphor C was used as a green-emitting phosphor (Y ₀ . ₈₅ Sm ₀ . ₀₅ Tb ₀ . ₁ ) terbium-activated yttrium/samarium oxysulfide phosphor represented by ₂ O ₂ S. % by weight, as a red-emitting phosphor (Y ₀ . ₄₄₅
Using 29% by weight _of a europium-activated yttrium oxide gadolinium phosphor represented by Gd _0.005 Eu _0.05 ) _{2 O 3 ,} a 40 Watt 3500K warm white fluorescent lamp was prepared according to a conventional method. Measure the visible light transmittance after lighting for a certain period of time. In addition, the phosphor L used in the comparative example lamp of Example 1 was used as the blue-emitting phosphor, and the green,
A 40 Watt 3500K warm white fluorescent lamp using the same phosphor as this example as a red-emitting phosphor was used as a comparative example lamp.

The visible light transmittance of the fluorescent lamp of this example was 155% compared to 100% of the fluorescent lamp of the comparative example, which is an improvement of 55%. In addition, the average color rendering index (Ra) at the initial stage of lighting is 85, and the lamp efficiency (lm/W) is 83l.
Indicates m/W.

Example 4 BaCo ₃ 2.682 mol, CaCo ₃ 0.149 mol,
Eu ₂ O ₃ 0.0745 mol, (NH ₄ ) ₂ HPO ₄ 1.84 mol,
SrCl ₂ 1.0692 mol, BaCl ₂ 0.1188 mol, H ₃ BO ₃ 0.16
Weigh the moles accurately and mix in a ball mill. Hereinafter, in the same manner as in Example 1, the general formula 2.98
( _{Ba 0.90 Ca 0.05 Eu 0.05 O )}・_0.92P2O5・0.33
_A phosphor _{represented by} ( _{Sr0.9Ba0.1 ) Cl2.0.08B2O3} is obtained _. Hereinafter, this fluorescent material will be referred to as fluorescent material D, and will be used as a blue light emitting material in the fluorescent lamp of this example. 7% by weight _of this phosphor _D was used as _a green- _emitting phosphor ( _{Y 0} . ₈₀ Ce ₀ .
70% _by weight as a red-emitting phosphor (Y _0.95
Using 13% by weight of a europium-activated yttrium oxide phosphor represented by _{Eu 0.05} ) ₂ O ₃ , a conventional method was used.
A 3500K warm white fluorescent lamp was made and the visible light transmittance was measured after being lit for 1500 hours. Further, the phosphor L used in the comparative example lamp of Example 1 was used as the blue-emitting phosphor, and the same phosphor as in this example was used as the green- and red-emitting phosphors.
A 3500K warm white fluorescent lamp is used as a comparative example lamp.

The visible light transmittance of the fluorescent lamp of this example was 185% compared to 100% of the fluorescent lamp of the comparative example, which is an improvement of 85%. In addition, the average color rendering index (Ra) at the initial stage of lighting is 85, and the lamp efficiency (lm/W) is 84l.
Indicates m/W.

Example 5 SrCo ₃ 2.55 mol, CaCo ₃ 0.33 mol, Eu ₂ O ₃ 0.06 mol, (NH ₄ ) ₂ HPO ₄ 1.80 mol, BaCl ₂ 1.197 mol,
0.063 mol of BaF ₂ and 0.24 mol of H ₃ BO ₃ are accurately weighed and mixed in a ball mill. Hereinafter, in the same manner as in Example 1, the general formula 3.0 (Sr ₀ . ₈₅ Ca ₀ . ₁₁ Eu ₀ . ₀₄ O)
A phosphor expressed as 0.90P ₂ O ₅ .0.35Ba (Cl _{0.9 F 0.1 )} .0.12B ₂ O ₃ is obtained. Hereinafter, this phosphor will be referred to as phosphor E.
, and is used as a blue-emitting phosphor in the fluorescent lamp of this example. 5% by weight of this phosphor E was used as a green-emitting phosphor (Y ₀ . ₈
50% _{by weight terbium-activated yttrium-gadolinium oxysulfide phosphor, designated Gd 0.1 Tb 0.1 ) 2 O 2 S} ;
As a red-emitting phosphor, 45% by weight of a _europium -activated yttrium- _gadolinium oxide phosphor represented by (Y ₀ . ₉₃ Gd ₀ . _{02 Eu 0} . Created a 3000K warm white fluorescent lamp,
Measure the visible light transmittance after lighting for 1500 hours. Further, the phosphor L used in the comparative example lamp of Example 1 was used as the blue-emitting phosphor, and the same phosphor as in this example was used as the green- and red-green-emitting phosphor. A white fluorescent lamp is used as a comparative example lamp.

The visible light transmittance of this example fluorescent lamp was 170% compared to 100% of the comparative example fluorescent lamp, which is an improvement of 70%. In addition, the average color rendering index (Ra) at the initial stage of lighting is 86, and the lamp efficiency (lm/W) is 85l.
Indicates m/W.

Example 6 SrCo ₃ 2.784 mol, Eu ₂ O ₃ 0.058 mol,
(NH ₄ ) ₂ HPO ₄ 1.82 mol, CaCl ₂ 1.0692 mol,
Precisely weigh 0.1188 mol of SrBv ₂ and 0.20H ₃ BO ₃ and mix in a ball mill. Hereinafter, in the same manner as in Example 1,
General formula 2.9 (Sr _{0. 96} Eu _{0. 04} O)・0.91P ₂ O ₅・0.33
A phosphor _represented by (Ca _0.9 Sr _{0.1 )} (Cl _{1.8 Br 0.2} )·0.10B _{2 O 3} is obtained. Hereinafter, this phosphor will be referred to as phosphor F, and will be used as a blue-emitting phosphor in the fluorescent lamp of this example. 19% by weight of _this phosphor F was used as a green-emitting phosphor ( _{La 0.05 Lu 0.05} Ce _0.75 Tb _0.15 ) _.
Cerium and _{terbium coactivated lanthanum} tercium phosphate phosphor 64% _by weight, denoted as _PO4 , with europium _{as a} red-emitting phosphor ( _{Y0.94Tb0.01Eu0.05} ) _2O3 Using 17% by weight of active yttrium terbium oxide phosphor, a 40 watt 6000K daylight color fluorescent lamp was prepared according to a conventional method, and the visible light transmittance was measured after being lit for 1500 hours. In addition, a 40 Watt 6000K daylight fluorescent material was prepared, using the fluorescent material L used in the comparative example lamp of Example 1 as the blue emitting fluorescent material, and using the same fluorescent materials as in this example as the green and red emitting fluorescent materials. The light lamp is used as a comparative example lamp.

The visible light transmittance of the fluorescent lamp of this example was 145% compared to 100% of the fluorescent lamp of the comparative example, which is an improvement of 45%. In addition, the average color rendering index (Ra) at the initial stage of lighting is 82, and the lamp efficiency (lm/W) is 81l.
Indicates m/W.

In order to reduce the price of the fluorescent lamp, it has a two-layer structure with a phosphor layer made of an inexpensive phosphor on the glass tube side and a phosphor layer made of an expensive phosphor on the discharge side. Although it is known that a fluorescent film is used, the fluorescent lamp of the present invention also uses an antimony and manganese co-activated calcium halophosphate phosphor on the glass tube side, and a fluorescent film on the discharge side as defined in the present invention. A phosphor film body consisting of a phosphor mixed layer may be provided in a laminated manner.

[Brief explanation of the drawing]

Figure 1 is an excitation spectrum diagram of the blue-emitting phosphor used in the Example and Comparative Example lamps, Figure 2 is an emission spectrum distribution diagram of the blue-emitting phosphor used in the Example lamp, and Figure 3 is the excitation spectrum diagram of the blue-emitting phosphor used in the Example lamp. FIG. 3 is an emission spectrum distribution diagram of an example lamp at the initial stage of lighting.

Claims (1)

[Claims] 1. The general formula is x(M ₁ −P・Eup・O)・yP ₂ O ₅・
aM′X ₂・bB ₂ O ₃ (However, M and M′ are at least one of strontium, calcium, and barium;
x is at least one of chlorine, fluorine, and bromine, 2.7≦
x≦3.1, 0.50≦y≦1.5, 0.10≦a≦0.50, 0.01≦
b≦0.50, 0.01≦p≦0.20); a divalent europium-activated haloborophosphate blue-emitting phosphor;
The general formula is (Ln・Tb) ₂ O ₂ S (where Ln is yttrium, lanthanum, gadolinium, cerium,
A terbium-activated rare earth oxysulfide green-emitting phosphor represented by at least one of lutetium and samarium, whose general formula is (Ln・Tb)PO ₄ (however, Ln
is a terbium-activated rare earth phosphate green-emitting phosphor whose general formula is (Ln・Ce・Tb)PO ₄
(However, Ln is at least one of yttrium, gadolinium, lanthanum, lutetium, and samarium. (Ln・
Eu) ₂ O ₃ (where Ln is at least one of yttrium, lanthanum, gadolinium, cerium, terbium, and samarium) and a europium-activated rare earth oxide red-emitting phosphor. A fluorescent lamp characterized by: 2. The fluorescent film contains 100% by weight, 5-45% by weight of blue-emitting phosphor, 20-70% by weight of green-emitting phosphor,
A fluorescent lamp according to claim 1, characterized in that the composition comprises 10 to 60% by weight of red-emitting phosphor.