KR100561554B1 - Panel glass composition for cathode-ray tube - Google Patents

Abstract

The present invention relates to a panel glass composition for cathode ray tubes used in color televisions and monitors, more specifically, 50 to 65% by weight of SiO ₂ , 0.1 to 5% by weight of Al ₂ O ₃ , 4 to 9% by weight of Na ₂ O , K ₂ O 4-9% by weight, Sb ₂ O ₃ 0.1-1% by weight, CeO ₂ 0.1-1% by weight, TiO ₂ 0.1-1% by weight, BaO 5-15% by weight, SrO 5-15%, ZrO ₂ comprises 0.1 to 5% by weight, ZnO 0.1 to 10% by weight and Bi ₂ O ₃ 0.01 to 1% by weight, wherein the content of (BaO + SrO + ZrO ₂ + ZnO + Bi ₂ O ₃ ) is It relates to a panel glass composition for a cathode ray tube having a weight of 23 wt% or more, an X-ray absorption coefficient of 0.6 kPa or more of 34 cm ⁻¹ or more, and a fine hardness of 520 kgf / mm 2 or more.

Cathode Ray Tube, Panel Glass, Composition

Description

Panel glass composition for cathode ray tube {PANEL GLASS COMPOSITION FOR CATHODE-RAY TUBE}

The present invention relates to a panel glass composition for a cathode ray tube, more specifically, SiO ₂ , Al ₂ O ₃ , Na ₂ O, K ₂ O, Sb ₂ O ₃ , CeO ₂ , TiO ₂ , BaO, SrO, ZrO ₂ , ZnO and Bi ₂ O ₃ , wherein the content of (BaO + SrO + ZrO ₂ + ZnO + Bi ₂ O ₃ ) is 23% by weight or more, and the X-ray absorption coefficient at 0.6 Hz is 34 cm ^{−. It} relates to a panel glass composition for a cathode ray tube having ^one or more and a microhardness of 520 kgf / mm 2 or more.

The cathode ray tube functions to cause an image to be formed on the panel glass by emitting an electron beam emitted from the cathode and stimulating a fluorescent material present on the inner surface of the panel glass provided at the front portion of the cathode ray tube. X-rays are generated during the emission of these electron beams. The X-rays penetrate the panel glass and reach the viewer in front of the television or monitor, which adversely affects the human body. Therefore, the panel glass composition for cathode ray tubes is required to have the ability to absorb such X-rays.

On the other hand, recently used flat panel glass is required to improve the mechanical properties than the curved panel glass, and the current trend is that the thickness of the panel glass is thinner, in order to enable this Improvement is required. However, when the thickness of panel glass becomes thin, the X-ray absorption effect will become low. Therefore, by adding components having high X-ray absorptivity to the panel glass composition for the cathode ray tube, it exhibits a certain level of X-ray absorption effect in spite of the thinned thickness, and at the same time adjusts the content of various compositional components to obtain physical properties Compositions for improving and maintaining panel glass have been developed (Korean Patent Laid-Open Publication Nos. 1996-0022307, 1996-0022308, 2000-0007335; Japanese Patent Laid-Open No. 7-206466). However, panel glass compositions according to these conventional techniques are still not satisfactory in the X-ray absorption effect.

In addition, as the thickness of the panel glass becomes thinner, the possibility of damage to the panel glass increases, and thus, improvement of mechanical properties such as fine hardness of the panel glass is required. However, a panel glass composition which improves the X-ray absorption effect and at the same time improves mechanical properties such as microhardness of panel glass has not been developed yet.

The present invention is to solve the problems of the prior art as described above, the object of the present invention, while maintaining the physical properties such as coefficient of thermal expansion at the level required for the panel glass for cathode ray tube, while having an excellent X-ray absorption effect It is to provide a panel glass composition for a cathode ray tube to improve mechanical properties such as fine hardness of the panel glass.

According to the present invention, 50 to 65% by weight of SiO ₂ , 0.1 to 5% by weight of Al ₂ O ₃ , 4 to 9% by weight of Na ₂ O, 4 to 9% by weight of K ₂ O 4, and 0.1 to 1% by weight of Sb ₂ O _3. , CeO ₂ 0.1-1%, TiO ₂ 0.1-1%, BaO 5-15%, SrO 5-15%, ZrO ₂ 0.1-5%, ZnO 0.1-10%, and Bi ₂ O ₃ 0.01 to 1% by weight, wherein the content of (BaO + SrO + ZrO ₂ + ZnO + Bi ₂ O ₃ ) is 23% by weight or more, and the X-ray absorption coefficient at 0.6Å is 34 cm ⁻¹ or more And a fine glass panel composition for a cathode ray tube having a fine hardness of 520 kgf / mm 2 or more.

SiO ₂ contained in the glass composition of this invention is a glass component, and it is preferable to be contained in 50 to 65weight% of a ratio in a composition. If the content of SiO _{2 in} the composition is less than 50% by weight, the chemical durability of the composition is deteriorated, and if it exceeds 65% by weight, there is a problem in that melting becomes difficult during processing.

In addition, Al ₂ O ₃ contained in the glass composition of the present invention is for increasing the chemical durability of the panel glass, it is preferably included in the ratio of 0.1 to 5% by weight in the composition. If the content in the composition of Al ₂ O ₃ is less than 0.1% by weight, there is no effect of chemical durability, and if it exceeds 5% by weight, there is a problem that the coefficient of thermal expansion is lowered.

In addition, Na ₂ O and K ₂ O included in the glass composition of the present invention are for maintaining the thermal expansion coefficient of the panel glass at a constant level, and are preferably included in the composition at a ratio of 4 to 9% by weight. If the content in the composition of Na ₂ O or K ₂ O is less than 4% by weight, the meltability of the glass is poor, if more than 9% by weight there is a problem that the chemical durability is lowered.

In addition, Sb ₂ O ₃ contained in the glass composition of the present invention is a clarifier for removing bubbles generated during melting during glass manufacturing, and is preferably included in the composition at a ratio of 0.1 to 1% by weight. When the content in the composition of Sb ₂ O ₃ is less than 0.1% by weight, bubbles generated during melting of the glass may not be smoothly removed, and when the content of Sb ₂ O ₃ exceeds 1% by weight, the clarification effect is saturated, and the clarification effect is no longer improved.

In addition, CeO ₂ and TiO ₂ contained in the glass composition of the present invention are used to prevent discoloration of the panel glass due to electron beam, X-ray, or ultraviolet rays generated in the cathode ray tube, and in a ratio of 0.1 to 1% by weight in the composition. It is preferable that each is included. When the content in the composition of CeO ₂ or TiO ₂ is less than 0.1% by weight, color development of the panel glass occurs, and when it exceeds 1% by weight, it is difficult to adjust the color tone of the glass.

In addition, BaO and SrO contained in the glass composition of the present invention are for improving the X-ray absorption effect of the panel glass, and are preferably contained in the composition at a ratio of 5 to 15% by weight. When the content of BaO or SrO in the composition is less than 5% by weight, the X-ray absorption effect of the panel glass cannot be obtained at a desired level, and when the content exceeds 15% by weight, the liquidus temperature rises, thereby causing devitrification during molding. .

In addition, ZrO ₂ contained in the glass composition of this invention is for improving the X-ray absorption effect of panel glass, and it is preferable that it is contained in the composition at a ratio of 0.1 to 5 weight%. If the content of ZrO ₂ is less than 0.1% by weight, the X-ray absorption effect of the panel glass may not be obtained at a desired level. If the content of ZrO ₂ is more than 5% by weight, it may be difficult to melt during processing.

In addition, ZnO contained in the glass composition of this invention is for improving the X-ray absorption effect of panel glass, and it is preferable to be contained in a composition of 0.1 to 10 weight%. When the content of ZnO in the composition is less than 0.1% by weight, the X-ray absorption effect of the panel glass may not be obtained at a desired level. When the content of ZnO exceeds 10% by weight, the liquidus temperature rises, resulting in devitrification during molding.

In addition, Bi ₂ O ₃ contained in the glass composition of the present invention is to improve the X-ray absorption effect of the panel glass and at the same time to improve the mechanical properties such as the fine hardness of the panel glass, 0.01 to 1% by weight in the composition It is preferably included in the ratio. When the content of Bi ₂ O _{3 in} the composition is less than 0.01% by weight, the effect of improving the mechanical properties such as the X-ray absorption effect and the fine hardness of the panel glass cannot be obtained at a desired level, and when it exceeds 1% by weight, it is used in the glass melting furnace. There is a problem that the erosion of the refractory is increased.

(BaO + SrO + ZrO ₂ + ZnO + Bi ₂ O ₃ ) is included in the glass composition of the present invention at least 23 wt%, more preferably 25-30 wt%. All of these components are used to improve the X-ray absorption effect of the panel glass. If the total content thereof is less than 23% by weight, the X-ray absorption effect of the panel glass cannot be obtained to a desired level.

In addition to the above components, the glass composition of the present invention may further include components typically included in the panel glass composition for cathode ray tube within the scope of achieving the object of the present invention.

As described above, 50 to 65% by weight of SiO ₂ , 0.1 to 5% by weight of Al ₂ O ₃ , 4 to 9% by weight of Na ₂ O, 4 to 9% by weight of K ₂ O, 0.1 to 1% by weight of Sb ₂ O ₃ , CeO ₂ 0.1-1%, TiO ₂ 0.1-1%, BaO 5-15%, SrO 5-15%, ZrO ₂ 0.1-5%, ZnO 0.1-10% and Bi ₂ O ₃ 0.01 to 1 is made, including the% by weight, in the (BaO + SrO + ZnO + ZrO ₂ + Bi ₂ O ₃₎ glass composition of the present invention at least the content is 23% by weight of the, X at least 34cm ^-1 0.6Å The glass of the present invention has a linear absorption coefficient, has a fine hardness of 520 kgf / mm 2 or more, and more preferably, the content of (BaO + SrO + ZrO ₂ + ZnO + Bi ₂ O ₃ ) is 25 to 30% by weight. The composition has an X-ray absorption coefficient at 0.6 kPa of 38 to 40 cm ^{-1 and has} a microhardness of 530 kgf / mm 2 or more.

Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

[Examples 1 and 2]

According to the composition ratios shown in Table 1 below, the ingredients were weighed at 300 g per batch, mixed in a gyro blender, and then charged into a 300 cc platinum crucible and melted at 1400 ° C. for 24 hours in an electric furnace. Thereafter, the melt was poured into a mold of 15 cm × 7 cm, molded, held at 540 ° C. for 1 hour in a slow cooling furnace, and then lowered to 300 ° C. at a rate of 1 ° C./min to completely slow cooling, thereby measuring the panel glass specimen Was prepared.

The density, X-ray absorption coefficient and microhardness of the manufactured panel glass test specimens were measured and shown in Table 1.

Property measurement method

① density

Density was measured by ASTM C729-75 method.

② X-ray absorption coefficient

The X-ray absorption coefficient was calculated by multiplying the mass absorption coefficient of each component at 0.6 Hz by the composition ratio of each component and multiplying the density by the value.

③ fine hardness

Microhardness was measured using a microhardness meter (Shimazu HMV).

[Comparative Examples 1-3]

According to the composition ratio shown in Table 1 below, in the same manner as in Examples 1 to 2 were prepared panel glass test pieces for measuring the physical properties of Comparative Examples 1 to 3, the physical properties also measured in the same manner as Examples 1 to 2 It is shown in Table 1. The composition component and content of Comparative Example 2 are the same as the composition component and content of Example 1 of Korean Patent Laid-Open Publication No. 1996-0022307, and the composition component and content of Comparative Example 3 contain 59.6 wt% of SiO ₂ instead of 59.9 wt%. Except for that, it is the same as the composition component and content of Example 1 of Japanese Patent Laid-Open No. 7-206466.

TABLE 1

 ingredient Composition ratio (wt%) Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 SiO ₂ 57.95 53.70 61.55 57.14 59.6 Al ₂ O ₃ 2.20 2.20 2.20 2.50 1.4 Na ₂ O 7.00 7.00 7.70 7.5 6.8 K ₂ O 8.00 7.00 8.20 7.0 8.3 Sb ₂ O ₃ 0.15 0.15 0.15 0.4 0.4 CeO ₂ 0.40 0.40 0.40 0.48 0.4 TiO ₂ 0.40 0.40 0.40 0.4 0.5 BaO 11.00 14.00 8.50 12.0 8.8 SrO 10.00 10.00 8.50 7.9 8.8 ZrO ₂ 2.30 2.35 2.00 2.5 2.9 ZnO 0.40 2.60 0.40 - 1.8 Bi ₂ O ₃ 0.20 0.20 - - - Li ₂ O - - - 0.28 - CaO - - - 1.3 - MgO - - - 0.6 0.2 Fe ₂ O ₃ - - - - 0.1 BaO + SrO + ZrO ₂ + ZnO + Bi ₂ O ₃ 23.9 29.15 19.4 22.4 22.3  Item Property measurement result Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Density (g / cm 3) 2.8520 2.9490 2.7570 2.861 2.8005 X-ray absorption coefficient at 0.6Å (cm ^-1 )  34.0  39.0  28.5  31.6  32.1 Fine hardness (kgf / ㎡) 530.2 531.2 513.3 512.7 514.6

According to the present invention, the X-ray absorption coefficient at 0.6 Å is 34 cm ⁻¹ or more, and the X-ray absorption effect is excellent, and the panel glass composition for the cathode ray tube having improved mechanical properties with a fine hardness of the panel glass of 520 kgf / mm 2 or more can be obtained. have.

Claims (3)

SiO ₂ 50 ~ 65% by weight, Al ₂ O ₃ 0.1 ~ 5 wt%, Na ₂ O 4 ~ 9 wt%, K ₂ O 4 ~ 9 _{wt%, Sb 2 O 3 0.1 ~} 1% by weight, CeO ₂ 0.1 ~ 1% by weight, 0.1-1% by weight of TiO ₂ , 5-15% by weight of BaO, 5-15% by weight of SrO, 0.1-5% by weight of ZrO _2, 0.1-10% by weight of ZnO and 0.01-1% by weight of Bi ₂ O ₃ It comprises a, wherein the content of (BaO + SrO + ZrO ₂ + ZnO + Bi ₂ O ₃ ) is more than 23% by weight, the X-ray absorption coefficient at 0.6 Å is 34cm ^-1 or more, the fine hardness The panel glass composition for cathode ray tubes characterized by more than 520kgf / mm 2. delete The method according to claim 1, wherein the content of (BaO + SrO + ZrO ₂ + ZnO + Bi ₂ O ₃ ) is 25 to 30% by weight, and the X-ray absorption coefficient at 0.6 kV is 38 to 40 cm ^-1 . The panel glass composition for cathode ray tubes characterized in that the fine hardness is 530kgf / mm 2 or more.