KR930003385B1 - LI CONTAIN InBO3-Tb GREEN LUMINOUS MATERIAL - Google Patents

Abstract

The green-light emitting fluorescent material of In1-x-yLixTby:BO3 [0<x<=0.09 mole: 0<y<=0.07 mole is mfd. by (a) mixing In2O3 and B2O3 as a main material with Li2CO3 or LiCl as an additive, Tb4O7 or TbCl as an activating agent, and alkali (earth) metal halide as a flux in the ball mill, (b) firing the mixture in a quartz or alumina crucible under the atmosphere at 800-1500 deg.C for 0.5-6 hr, and (c) washing and drying the fired fluorescent material. The fluorescent material is useful for the CRT for display.

Description

Li-containing InBO3-Tb-based green phosphor

FIG. 10 is a graph showing relative luminance of luminance of a Li-containing LiBO ₃ Tb-based green phosphor according to a Li content change based on 100% of the luminance of a conventional InBO ₃ -Tb-based green phosphor.

The present invention relates to an InBO ₃ (indium borate) -Tb (terbium) -based green phosphor used in a cathode ray tube for a display. Particularly, a part of In (indium) in InBO ₃ is replaced with Li (lithium). A Li-containing InBO ₃ -Tb-based green phosphor.

In general, in the case of a cathode ray light phosphor, particularly a phosphor of a cathode ray tube for a display, flickering of the screen occurs due to a flicker effect, which is a pulsation of a vacuum tube current that occurs remarkably in a low frequency region. The user has a problem that the eyes easily feel fatigue, and there is a method of changing the flame frequency to prevent such flicker phenomenon, but the method of changing the flame frequency has been limited by the regulations.

On the other hand, as another method for preventing the flicker phenomenon, the afterglow time of the phosphor, which is the light emission time after stopping the supply of the stimulus energy to the phosphor, is lengthened. Hanaro InBO ₃ -based phosphors have been widely used.

However, when InBO _{3 type} phosphor is used under electron excitation such as a display cathode ray tube, a projection tube, and a low-speed electron excitation fluorescent display tube, there is a problem that the luminance of the phosphor is insufficient.

In order to solve this problem, the present invention replaces a portion of In in the InBO ₃ -Tb-based green phosphor with Li (lithium) so that the emission color is higher under excitation such as an electron beam without substantially changing the emission color. It is an object to provide a Li-containing InBO ₃ -Tb-based phosphor having efficiency.

The present invention is described in detail as follows.

That is, according to the present invention, indium compound, In ₂ O ₃ (indium oxide) and boric acid compound or B ₂ O ₃ (boron oxide) are used as the main raw material of the phosphor, and Li (substituted in part of the InBO ₃ -Tb-based phosphor) Lithium compounds such as Li ₂ CO ₃ (lithium carbonate) or LiCl (lithium chloride) are used as an additive to provide lithium), while Tb ₄ O ₇ (terbium oxide) or TbCl (terbium chloride) is used as an activator. To prepare a phosphor.

At this time, an alkali metal halide or an alkaline earth metal halide is added as a flux to grow the phosphor particles and lower the firing temperature.

The raw materials and additives of the above-mentioned phosphors and materials such as an activator and a flux are sufficiently mixed using a mixing device such as a pestle or a ball mill, and then filled into a heat-resistant container such as quartz or alumina crucible, and the atmospheric pressure atmosphere, Fire for 30 minutes to 6 hours at 800 ~ 1500 ℃.

The calcined phosphor is washed and dried

In _1-xy Li _x Tb _y : BO ₃

here

x is 0 <x≤0.09mole

y is 0 <y≤0.07mole

The phosphor of the present invention having the composition formula is prepared.

As an effect of the prepared Li-containing InBO ₃ -Tb-based green phosphor of the present invention as described above, a 10% afterglow time of 15 to 20ms can be obtained a heavy afterglow, color shift or film during the afterglow time The film has the advantage of being uniform when formed, and because of its good color purity and long afterglow, no flickering or staining occurs due to the flicker effect. The advantage is that it can be used for high resolution CRTs and mixed phosphors for displays.

The following is an embodiment of the present invention.

Example 1

The raw materials were mixed in the following amounts to prepare Li-containing InBO ₃ Tb-based green phosphor of the present invention and compared them with the conventional InBO ₃ -Tb-based phosphor. In other words,

In ₂ O ₃ (indium oxide): 100 g

Tb ₄ O ₇ (terbium oxide): 24 g

B ₂ O ₃ (boron oxide): 320 g

Li ₂ CO ₃ (lithium carbonate): 7.2 g

After mixing sufficiently using a pestle or a ball mill (Ball Mill), it was filled in an alumina crucible, the lid was sealed and placed in an electric furnace and calcined at 1400 ℃ for 3 hours.

Then, washed and dried to prepare a phosphor of the present invention containing Li.

Thus producing a Li-containing system of the present invention InBO ₃ -Tb results of measuring the luminescence properties of a green phosphor, Li containing the present invention with respect to the luminescence brightness is 100% of the conventional green phosphor-based InBO ₃ -Tb -Tb InBO _3-base phosphor It can be seen that the luminous luminance of the light emitting efficiency is improved to about 143%.

Example 2

As in the embodiment 1 In ₂ O ₃ (indium oxide), 100g, Tb ₄ O ₇ (terbium oxide) into a 24g Li ₂ CO ₃ B ₂ in which the (lithium carbonate) The amount of 8.5g, Example 1 After mixing 550 g of H ₃ BO ₃ (boric acid) instead of O ₃ (boron oxide) using a pestle or ball mill, fill it into an alumina crucible, seal the lid, and place it in an electric furnace. The phosphor of the present invention containing Li was prepared by baking, washing and drying at 1400 ° C. for 3 hours.

Thus producing a Li-containing system of the present invention InBO ₃ -Tb results of measuring the luminescence properties of a green phosphor, Li containing the present invention with respect to the luminescence brightness is 100% of the conventional green phosphor-based InBO ₃ -Tb -Tb InBO _3-base phosphor It can be seen that the luminous luminance of the light emitting efficiency is increased to about 145%.

In order to compare the light emission characteristics of the Li-containing InBO ₃ -Tb green phosphor of the present invention prepared in Examples 1 and 2 and the conventional InBO ₃ -Tb green phosphor containing no Li, the Li content is changed. Relative luminance of the phosphor according to the present invention was measured and expressed as relative luminance (%) based on the luminance of luminance 100% of the conventional InBO ₃ -Tb-based green phosphor, based on the relative luminance of 100% It is shown in (%) and attached to the accompanying drawings.

In the drawing, the horizontal axis representing the change in Li content is the x value in the composition formula, and the vertical axis representing the change in the light emission luminance represents a relative value of 100% of the light emission luminance of the conventional InBO ₃ -Tb green phosphor containing no Li. .

As can be seen from the analysis of the graph shown in the drawings, the emission luminance of the Li-containing InBO ₃ -Tb-based green phosphor of the present invention is 143% in Example 1 and 145% in Example 2, which is at least 10 depending on the Li content. It can be seen that the luminous efficiency was improved by more than 50%.

On the other hand, in the emission chromaticity point measurement, the emission chromaticity point of the Li-containing InBO ₃ -Tb-based green phosphor of the present invention is X = 0.3257, Y = 0.06271, the emission chromaticity test of the conventional InBO ₃ -Tb-based green phosphor, X = 0.525, It was almost the same as Y = 0.6276.

Claims (2)

In a typical InBO ₃ -Tb-based green phosphor used in a cathode ray only for display, Li-containing InBO ₃ -Tb-based green phosphor, characterized in that the substitution of a portion of the InBO ₃ In to Li. The composition formula of the Li-containing InBO ₃ -Tb green phosphor is represented by In _1-xy Li _x Tb _y : BO ₃ , and the values x and y of Li and Tb contained are respectively. 0 <x≤0.09mole 0 <y≤0.07mole Li-containing InBO ₃ -Tb-based green phosphor, characterized in that.

Images