KR100358573B1 - Luminescent silicate-borate substances - Google Patents

Abstract

The present invention preferably activates a variety of luminescent screens, particularly stable for use in light emitting screens, especially low pressure mercury vapor discharge lamps of all types and types, with improved luminous properties and remarkably stable under the action of short-wave ultraviolet radiation, compared to conventional luminescent materials. Light emitting silicate-borate material.

The light emitting material according to the present invention is based on the rare earth metal metaborate of the formula (1).

(Y, La) _1-xyz Ce _x Gd _y Tb _z (Mg, Zn, Cd) _1-p Mn _p B _5-qs (Al, Ga) _q (X) _s O ₁₀

Here, X is Si, Ge, P, Zr, V, Nb, Ta, W or the sum of these elements, and p, q, s, x, y and z are alternatively ≤ 1.

The luminescent materials can be used either individually or as a mixture in the light emitting layer of the screen or in a low pressure discharge lamp.

Description

Luminescent silicate-borate material {LUMINESCENT SILICATE-BORATE SUBSTANCES}

The present invention preferably provides a variety of activated, improved luminous properties and remarkably stable under the action of short-wave ultraviolet radiation, suitable for use in light emitting screens, in particular low pressure mercury discharge lamps of all kinds and types. Luminescent silicate-borate materials.

Due to the typical terbium emission with a maximum wavelength of about 541 to 543 nm, compounds which are emitted in narrow bands are preferably used as green components in fluorescent lamps, in particular small fluorescent lamps and triphosphor tube fluorescent lamps. These are the most important materials: luminescent materials cerium magnesium aluminate: Tb (CAT) (AT 351635), lanthanum phosphate: Ce, Tb (LAP) (DE 33 26 921 and US 4 891 550), and lanthanum Phosphate silicates: Ce, Tb (LAPS) (DE 32 48 809) and Y ₂ SiO ₅ : Ce, Tb (EP 037 688). All these luminescent materials are characterized by high thermal stability and high luminous efficiency. The disadvantage is the high manufacturing cost incurred as the production temperature is required to be 1,300 to 1,600 ° C.

Other light emitting materials having a maximum emission wavelength of 542 nm are gadolinium magnesium pentaborate: Ce, Tb described in EP 023 068. The luminescent material CBT is characterized by a relatively low production temperature which only slightly exceeds 1000 ° C. Since the light emitting material has excellent stability and excellent emission characteristics, the light emitting material is used in the same manner as the light emitting materials CAT, LAP, LAPS, and Y ₂ SiO ₅ : Ce, Tb. It is disadvantageous in that it is difficult to be processed and processed.

It is an object of the present invention to further develop luminescent materials and processing properties and to develop luminescent materials which can be used in all ordinary fluorescent lamps, small energy-saving lamps and the latest fluorescent lamps.

1 is a graph showing the relationship between the relative emission intensity and the wavelength of the material according to Example 2 of Table 1,

2 is a graph showing the relationship between the relative emission intensity and the wavelength of the material according to Example 9 of Table 2,

3 is a graph showing the relationship between the relative emission intensity and the wavelength of the material according to Example 14 of Table 3,

According to the present invention, the object is achieved by the rare earth metal metaborate-based light emitting material of the general formula (1).

(Formula 1)

(Y, La) _1-xyz Ce _x Gd _y Tb _z (Mg, Zn, Cd) _1-p Mn _p B _5-qs (Al, Ga) _q (X) _s O ₁₀

In Formula 1 above

X is Si, Ge, P, Zr, V, Nb, Ta, W or the sum of these elements,

y = z = p = 00.01≤x≤1.0

0≤q≤1.0

0 <s≤1.0

z = p = 0 and y ≠ 00.01≤x≤1-y

0.02≤y≤0.80

0≤q≤1.0

0 <s≤1.0

p = 0 and z ≠ 00.01≤x≤1-y-z

O≤y≤0.98

y + z≤0.99

0.01≤z≤0.75

0≤q≤1.0

0 <s≤1.0

z = 0 and p ≠ 00.01≤x≤1-y

0≤y≤0.99

0.01≤p≤0.30

0≤q≤1.0

0 <s≤1.0

p ≠ 0 and z ≠ 00.01≤x <1-y-z

0≤y≤0.98

0.01≤z≤0.75

x + z≤0.99

0.01≤p≤0.30

0≤q≤1.0

0 <s≤1.0

All of the above luminescent compounds have a monoclinic structure with space group P2 ₁ / c which can be compared with the structure of LnMgB ₅ O _10. See B. Saubat, M. Vlasse and C. Fouassier, J. of Solid State Chem. 34 (1980) 3, pages 271-277.

The luminescent material according to the invention has a maximum emission at 542 nm and / or has a wide emission band at 630 nm. The change in the maximum emission band is closely related to the amount and type of element X incorporated.

The invention is described in more detail below with reference to various examples and test results.

Test results for the luminescent materials and various samples according to the invention are shown in Tables 1-5 and FIGS.

In Tables 1-4, Rel. int. is the relative emission intensity at maximum emission and Rel. integr. Intensity is the relative integrated emission intensity and q is the relative quantum yield. An unsubstituted sample of luminescent material (x = 0) is described by Welker, J. of Luminescence 48/49 (1991), page 53 and Smets Mater. Chem. and Phys. 16 (1987), information on page 292 is used as a standard for comparison of quantum yields.

Example

A. Light-emitting Material of Chemical Formula Gd _0.6 Ce _0.2 Tb _0.2 MgAl _0.1 Si _0.05 B _4.85 O ₁₀ According to Example 2 of Table 1

Starting materials are as follows:

H ₃ BO ₃ 5.176 g

CeO ₂ 0.431 g

Gd ₂ O ₃ 1.360 g

1.230 g (0.05 molar excess) MgCO ₃

SiO ₂ 0.038 g

Tb ₄ O ₇ 0.467 g

Al ₂ O ₃ 0.064 g

Preparation: Starting materials comprising substances which can be present in the form of oxides or which can be converted into oxides are mixed with 0.05 mol excess magnesium and excess boric acid between 5-50% in the above ratio and 30 minutes at 600 ° C. depending on the reaction conditions. Pre-ignition while. After crushing the intermediate, it was further heated to 1035 ° C. in a corundum crucible and ignited at the reaction temperature for 3 hours under reducing conditions in a nitrogen / hydrogen mixture. The final product was washed with water, dried and sieved. The compound obtained exhibits a maximum emission at 542 nm as shown in FIG. 1.

B. Light-emitting Material of Chemical Formula Gd _0.6 Ce _0.2 Tb _0.2 MgAl _0.1 Si _0.05 B _4.80 O ₁₀ According to Example 5 Listed in Table 1

Starting materials are as follows:

H ₃ BO ₃ 5.176 g

CeO ₂ 0.431 g

Gd ₂ O ₃ 1.360 g

1.230 g (0.05 g excess) MgCO ₃

SiO ₂ 0.075 g

Tb ₄ O ₃ 0.467 g

Al ₂ O ₃ 0.064 g

Preparation: Prepared similarly to Example 2 described in Table 1. The light emitting compound obtained exhibits maximum light emission at 542 nm.

C. Light-emitting Material of Chemical Formula Gd _0.8 Ce _0.2 Mg _0.9 Mn _0.1 Al _0.1 Si _0.05 B _4.85 O ₁₀ According to Example 9 described in Table 2

Starting materials are as follows:

H ₃ BO ₃ 12.748 g

CeO ₂ 1.291g

Gd ₂ O ₃ 5.439 g

3.342 g (0.05 molar excess) MgCO ₃

MnCO ₃ 0.4311 g

Al ₂ O ₃ 0.1911g

SiO ₂ 0.113 g

Preparation: The starting materials were mixed thoroughly, introduced into a furnace at room temperature and then heated to 560 ° C. under a nitrogen atmosphere. After standing for 30 minutes, the intermediate was removed and ground. The pulverized intermediate was introduced into the furnace again and then ignited at 1015 ° C. for 4 hours under reducing conditions. After cooling to 500 ° C., the fine crystalline final product was washed with water at 80 ° C. with stirring and then dried. The compound thus obtained has an emission band showing maximum emission at 628 nm. The emission spectrum is shown in FIG.

D. Light-emitting Material of Chemical Formula Gd _0.8 Ce _0.2 Mg _0.9 Mn _0.1 Si _0.1 B _4.9 O ₁₀ According to Example 11 Listed in Table 2

Starting materials are as follows:

H ₃ BO ₃ 12.748 g

CeO ₂ 1.291g

Gd ₂ O ₃ 5.439 g

3.342 g (0.05 molar excess) MgCO ₃

MnCO ₃ 0.431 g

SiO ₂ 0.226 g

Preparation: All starting materials were treated as in Example 9 listed in Table 2 but ignited for 6 hours at the reaction temperature mentioned. A luminescent compound was formed having an emission band showing maximum emission at 629 nm.

E. Light-emitting Material of Chemical Formula Gd _0.6 Ce _0.2 Tb _0.2 Mg _0.9 Mn _0.1 Al _0.1 Si _0.05 B _4.85 O ₁₀ According to Example 14 Listed in Table 3

Starting materials are as follows:

H ₃ BO ₃ 4.801g

CeO ₂ 0.431 g

Gd ₂ O ₃ 1.360 g

1.113 g (0.05 molar excess) MgCO ₃

MnCO ₃ 0.144 g

SiO ₂ 0.075 g

Tb ₄ O ₃ 0.467 g

Al ₂ O ₃ 0.064 g

Preparation: The starting material was heated to 580 ° C. in a nitrogen atmosphere, left for 30 minutes, then removed from the furnace and triturated. The intermediate was then further ignited at 1025 ° C. for 2 hours under reducing conditions. After removal and grinding, a second ignition was carried out under the same conditions. The cooled and washed product has a characteristic emission line of terbium at 542 nm and manganese emission band at 628 nm as shown in FIG. 3.

Example Number Chemical formula Remarks Rel.int. (%) Rel.integr.intensity (%) q One Gd _0.6 Ce _0.2 Tb _0.2 MgAl _0.1 B _4.9 O ₁₀ High temperature cleaning 100 100 0.93 2 Gd _0.6 Ce _0.2 Tb _0.2 MgAl _0.1 Si _0.05 B _4.85 O ₁₀ High temperature cleaning 103 102 0.95 3 Gd _0.6 Ce _0.2 Tb _0.2 MgAl _0.05 Si _0.05 B _4.9 O ₁₀ EDTA 101 100 0.94 4 Gd _0.6 Ce _0.2 Tb _0.2 MgSi _0.1 B _4.9 O ₁₀ EDTA 99 99 0.91 5 Gd _0.6 Ce _0.2 Tb _0.2 MgAl _0.1 Si _0.1 B _4.8 O ₁₀ High temperature cleaning 101 100 0.93 6 Gd _0.6 Ce _0.2 Tb _0.2 ZnAl _0.05 Si _0.05 B _4.9 O ₁₀ Untreated 102 101 0.94 7 Gd _0.6 Ce _0.2 Tb _0.2 Mg _0.75 Cd _0.25 Al _0.1 Si _0.05 B _4.85 O ₁₀ Untreated 102 101 0.94

Example Number Chemical formula Remarks Rel.int. (%) Rel.integr.intensity (%) q 8 Gd _0.8 Ce _0.2 Mg _0.9 Mn _0.1 Al _0.1 B _4.9 O ₁₀ High temperature cleaning 100 100 0.90 9 Gd _0.8 Ce _0.2 Mg _0.9 Mn _0.1 Al _0.1 Si _0.05 B _4.85 O ₁₀ High temperature cleaning 104 105 0.94 10 Gd _0.8 Ce _0.2 Mg _0.9 Mn _0.1 Al _0.05 Si _0.05 B _4.9 O ₁₀ Untreated 102 104 0.93 11 Gd _0.8 Ce _0.2 Mg _0.9 Mn _0.1 Si _0.1 B _4.9 O ₁₀ EDTA 99 101 0.91 12 Gd _0.8 Ce _0.2 Mg _0.9 Mn _0.1 Al _0.25 Si _0.75 B _4.9 O ₁₀ High temperature cleaning 100 101 0.91

Example Number Chemical formula Remarks Rel.int. (%) Rel.integr.intensity (%) q 13 Gd _0.6 Ce _0.2 Tb _0.2 Mg _0.9 Mn _0.1 Al _0.1 B _4.9 O ₁₀ High temperature cleaning 100 100 0.90 14 Gd _0.6 Ce _0.2 Tb _0.2 Mg _0.9 Mn _0.1 Al _0.1 Si _0.05 B _4.85 O ₁₀ High temperature cleaning 102 103 0.92 15 Gd _0.6 Ce _0.2 Tb _0.2 Mg _0.9 Mn _0.1 Si _0.1 B _4.9 O ₁₀ High temperature cleaning 99 100 0.90

Example Number Chemical formula Remarks Rel.int. (%) Rel.integr.intensity (%) q 16 Gd _0.6 Ce _0.2 Tb _0.2 MgAl _0.1 Ge _0.05 B _4.85 O ₁₀ High temperature cleaning 101 101 0.91 17 Gd _0.6 Ce _0.2 Tb _0.2 MgAl _0.1 Zr _0.05 B _4.85 O ₁₀ High temperature cleaning 100 100 0.9 18 Gd _0.8 Ce _0.2 Mg _0.9 Mn _0.1 Al _0.1 P _0.05 B _4.85 O ₁₀ High temperature cleaning 102 101 0.91 19 Gd _0.8 Ce _0.2 Mg _0.9 Mn _0.1 Al _0.1 V _0.05 B _4.85 O ₁₀ High temperature cleaning 99 99 0.89 20 Gd _0.6 Ce _0.2 Tb _0.2 MgAl _0.1 Nb _0.05 B _4.85 O ₁₀ High temperature cleaning 95 94 0.84 21 Gd _0.8 Ce _0.2 Mg _0.9 Mn _0.1 Al _0.1 Ta _0.05 B _4.85 O ₁₀ High temperature cleaning 96 96 0.85

This simply O ₁₀ to O _{10 + s} instead due to an excess of boric acid and an excess of divalent cations, the charge supplemented by oxygen atoms that occurs as a result of the selected substitution is not considered in Table 1-4 and the embodiment for manufacturing It is referred to as an approximation.

The results according to Table 1 for the luminescent material BSCT, the results according to Table 2 for the luminescent material BSCM, the results according to Table 3 for the luminescent material BSCTM and the results according to Table 4 for the luminescent material BSCX are simple penta known to date It is demonstrated that the luminescent properties of borate luminescent materials are significantly improved in some cases, in particular by the additional incorporation of silicon and the formation of luminescent silicate-borate materials, wherein only the manganese activated luminescent silicate-borate materials according to Table 5 The structure, based on the example of, is essentially different from the structure of luminescent pentaborate materials known to date of these silicate-borate materials, and is generally reduced in lattice as indicated by the increase in the magnitude of the θ value in the diffractometer pattern. Happens.

In Table 5, Si = 0 represents CBM in Example 8, Si = 0.05 represents BSCM in Example 10, Si = 0.1 represents BSCM in Example 11 and additionally Si = 0.05 in Example 9 Represents BSCM. Similar structural changes occur in all samples tested, with smaller central ions inducing lattice shrinkage, but larger sizes inducing lattice expansion. In the first case, improvement of the luminescence properties is mainly observed, and in the second case, slightly deteriorated or invariant is observed compared to the conventional luminescent pentaborate material.

In all of the examples described in Tables 1 to 5, certain silicate-borate as well as germanate-borate and phosphate-borate are excellent base lattice for activation with cerium, terbium, gadolinium and manganese, and because of their very good luminescent properties, It can be used individually or as a mixture in a luminescent screen. In particular, they can be used as light emitting layers in low pressure mercury discharge lamps, which lead to a few percent increase in luminous flux.

Claims (9)

A rare earth metal metaborate light emitting silicate-borate material of Formula 1 (Formula 1) (Y, La) _1-xyz Ce _x Gd _y Tb _z (Mg, Zn, Cd) _1-p Mn _p B _5-qs (Al, Ga) _q (X) _s O ₁₀ Wherein X is Si, Ge, P, Zr, V, Nb, Ta, W or the sum of these elements, when y = z = p = 0, 0.01 ≦ x ≦ 1.0, 0 ≦ q ≦ 1.0, and 0 <s ≦ 1.0, when z = p = 0 and y ≠ 0, 0.01 ≦ x ≦ 1-y, 0.02 ≦ y ≦ 0.80, 0 ≦ q ≦ 1.0, and 0 <s ≦ 1.0, when p = 0 and z ≠ 0, 0.01≤x≤1-y-z, O≤y≤0.98, y + z≤0.99, 0.01≤z≤0.75, 0≤q≤1.0, and 0 <s≤1.0, when z = 0 and p ≠ 0, 0.01≤x≤1-y, 0≤y≤0.99, 0.01≤p≤0.30, 0≤q≤1.0, and 0 <s≤1.0, and When p ≠ 0 and z ≠ 0, 0.01≤x <1-yz, 0≤y≤0.98, 0.01≤z≤0.75, x + z≤0.99, 0.01≤p≤0.30, 0≤q≤1.0, and 0 < s ≤ 1.0. The light emitting silicate-borate material of claim 1 wherein y = z = p = 0 and 0.01 ≦ x ≦ 0.50. The light emitting silicate-borate material of claim 1 wherein z = p = 0, 0.01 ≦ x ≦ 0.50, 0.05 ≦ y ≦ 0.75 and x + y ≦ 1. The light emitting silicate-borate material of claim 1 wherein p = 0, 0.01 ≦ z ≦ 0.75 and x + y + z = 1. The light emitting silicate-borate material of claim 1, wherein z = 0, 0.01 ≦ p ≦ 0.30 and x + y = 1. The light emitting silicate-borate material of claim 1 wherein 0.01 ≦ p ≦ 0.30, 0.01 ≦ z ≦ 0.75 and x + y + z = 1. The light emitting silicate-borate material according to claim 1, wherein at least one said light emitting material is used as a mixture in a light emitting screen. The light emitting silicate-borate material according to claim 1, wherein at least one said light emitting material is used in the light emitting layer of low pressure mercury discharge lamps or as a mixture with respect to the light emitting layers. The light-emitting silicate-borate material according to any one of claims 1 to 6, which is arranged inside a discharge vessel of a low pressure mercury vapor discharge lamp having a diameter of 5 mm or more and an ultraviolet discharge force of 200 W / m 2 or more.