JPH05311357A - Shadow-mask material - Google Patents

Abstract

PURPOSE:To develop an Fe-Ni shadow-mask material for the highdefinition color television picture tube having more uniform etching drillability than before. CONSTITUTION:The crystal grain size of the Fe-Ni shadow-mask material is controlled to >=9.0 fineness number, and the aggregation degree of the (100) face on the rolling surface is adjusted to <35%. The rolling and annealing history, annealing temp. before final rolling and final draft and the annealing temp. and time when final annealing is applied are controlled. Since the crystal grain size is controlled to >=9.0 fineness number, the etched hole and wall surface are smoothed. As the aggregation degree of the (100) face on the rolling surface is controlled to <35%, the crystals are oriented at random, and the etching uniformity is improved. The shadow-mask material is applicable to the high-definition color television picture tube.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shadow mask material used in a picture tube for a color television, and more particularly to an Fe-Ni-based high definition color television in which crystal grain size and texture are specified in specific ranges. The present invention relates to a shadow mask material for a picture tube for John.

[0002]

2. Description of the Related Art A shadow mask is used as a color selection electrode in a color television picture tube.

As a material for a shadow mask, low carbon aluminum killed steel has been used so far, but recently, an amber alloy material (Fe-36% N) having a low thermal expansion characteristic has been used.
i) is more often used.

This is due to the following reasons. That is, when the color cathode ray tube is operated, the electron beam directed to the shadow mask passes through the aperture of the shadow mask and directly strikes the surface of the shadow mask non-opening portion, so that the shadow mask is occasionally damaged. Is heated up to 80 ° C. At this time, if the material has a large thermal expansion, the thermal expansion of the shadow mask causes a decrease in the color purity, but the use of Fe-Ni-based amber, which has a low thermal expansion coefficient, reduces the color purity due to the thermal expansion. It is to prevent it.

There are several manufacturing methods for such a shadow mask, but typically, an Fe-Ni amber material is ingot, forged, repeatedly rolled and annealed, and finally cold-rolled to an appropriate thickness. It is indispensable to carry out final recrystallization annealing if necessary after forming the shadow mask material and to form a large number of perforations therein by well-known etching using ferric chloride, for example. After that, well-known processes such as molding and blackening are performed to manufacture the shadow mask.

However, this Fe-Ni-based amber alloy has a problem that it is inferior in etching piercing property to the conventional low carbon aluminum killed steel. This problem is because the etching speed varies depending on the crystal orientation of each crystal grain, so when etching the Fe-Ni-based shadow mask material, which is a polycrystalline body, irregularities are formed along the crystal grains, and proper perforations are not formed, resulting in shadows. The quality of the mask is reduced.

In this regard, it has been conventionally known that the smaller the crystal grains, the smoother the hole shape and the etched wall surface after etching and the better the quality of the mask. The number of crystal grains on the wall is specified. Furthermore, for example, JP-A-59-
As described in Japanese Patent No. 149638, it has been conventionally attempted to uniformize etching by making crystal grains fine and increasing the degree of aggregation of {100} planes with respect to the rolling plane.

[0008]

However, this is still insufficient as a material for a high definition mask, which has recently been in increasing demand. An object of the present invention is to develop a shadow mask material for a picture tube for an Fe-Ni-based high-definition color television having a more uniform etching perforation property than ever before.

[0009]

SUMMARY OF THE INVENTION As a result of various studies conducted by the present inventors in view of such a point, it was rather a problem that the degree of aggregation of {100} planes on the conventional shadow mask rolling surface was increased. On the contrary, it was found that it is desirable to make the degree of aggregation of {100} faces as low as possible for a high definition mask. Based on this knowledge opposite to the conventional one, the present invention is characterized in that the grain size is 9.0 or more in grain size number, and the degree of aggregation of {100} faces to the rolled face is less than 35%. An Fe-Ni-based shadow mask material is provided.

[0010]

The smaller the crystal grains, the smoother the hole shape and the etched wall surface after etching, and the quality of the mask is improved. When the grain size is 9.0 or more in terms of grain size, a smooth post-etching hole shape and etching wall surface are guaranteed. When the degree of aggregation of {100} planes with respect to the rolled surface is less than 35% as the crystal orientation, the crystal orientation becomes random and the etching uniformity is improved.

[0011]

[Examples] The Fe-Ni-based shadow disk material is Fe-34 typified by an amber alloy material (Fe-36% Ni).
Up to 38 wt% Ni, including Si, Mn, Cr, Co, Ti, Zr, Mo, N as additional elements
It is also possible to add one or more of b, B, V, Be, Al, Ta and W.

The Fe-Ni-based shadow mask material is prepared by melting an ingot having an appropriate composition, repeating forging, rolling and annealing, and finally cold rolling to obtain a shadow mask material having an appropriate thickness. After performing final recrystallization annealing or strain relief annealing, a large number of perforations are coated with a photoresist, and a pattern is baked and developed.
It is manufactured by etching using an etching solution such as iron, and then forming by a well-known photoetching technique of removing the resist.

Crystal structure is important for etching. In the present invention, the grain size is 9.0 in terms of grain size number.
As described above, it is preferably 9.5 to 12. Then, the degree of aggregation of {100} planes on the rolled surface needs to be less than 35%. The preferred degree of aggregation is less than 30%.

The reason for the limitation will be described. It has been conventionally known that the smaller the crystal grains, the smoother the hole shape and the etched wall surface after etching and the better the quality of the mask. In the above-mentioned JP-A-61-39343, the opening wall is The number of such crystal grains is specified. In the present invention, this point is the same, and the crystal grain size is 9.0 in the grain size number.
It is necessary to be above. Preferably 9.5-12
The range is. The crystal grain size is based on the JIS standard. Further, as known from JP-A-59-149638, it has been conventionally performed to increase the degree of aggregation of {100} planes. However, when one orientation is aggregated, each crystal grain becomes Even if it is small, the crystal grains adjacent to each other have almost the same orientation, so that the actual result is the same as in the case where the crystal grain is large, which is not preferable. Therefore, the crystallographic orientation should be as random as possible, and the degree of aggregation of {100} planes on the rolling plane should be 3
It should be less than 5%. The preferred degree of aggregation is less than 30%.

In the present invention, preferable manufacturing conditions are as follows: hot rolling, rolling at a rolling degree not exceeding 80%, recrystallization annealing, and rolling again at a rolling degree not exceeding 80%. .. Then, at 650 to 1150 ° C. for 5 seconds to 60
Minute annealing is performed to refine the crystal grains. Final rolling degree is 10-5
0% and 650-11 if final recrystallization annealing is required
It is carried out at 50 ° C. for 5 seconds to 60 minutes.

Examples and Comparative Examples Fe-36% Ni alloy was used as the chemical composition of the sample material. From the same ingot, the degree of cold rolling before the final recrystallization annealing and the final recrystallization annealing conditions were changed to obtain the grain sizes and {100} shown in Table 1.
A test material having a degree of surface aggregation was prepared. In addition, all the test materials were subjected to final cold rolling with a workability of 15% after final recrystallization annealing to obtain cold-rolled sheets with a plate thickness of 0.15 mm.

A large number of holes were formed in the cold rolled sheet by an etching solution containing ferric chloride as a main component, and the etching piercing property at this time was evaluated. The results are also shown in Table 1. The mask pattern used had a high definition and was difficult to etch.

[0018]

[Table 1]

As can be seen from Table 1, the inventive examples showed better etching piercing properties than the comparative examples and were able to produce good quality masks with uniform piercing.

[0020]

Industrial Applicability The Fe-Ni-based shadow mask material having more uniform etching perforation than the conventional one has been successfully developed, and the shadow mask for a picture tube for a high-definition color television, which has recently been increasing in demand, has been dealt with. You can

Claims (1)

[Claims] 1. An Fe-Ni-based shadow mask material having a grain size of 9.0 or more in terms of grain size and a degree of aggregation of {100} planes with respect to a rolling plane of less than 35%.