JP2853070B2 - Method of manufacturing thin plate for shadow mask - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a thin plate for a shadow mask.

[0002]

2. Description of the Related Art A shadow mask type color picture tube is provided with a shadow mask having a large number of small openings formed by photoetching based on a predetermined design standard. As this material, conventionally, the plate thickness is 0.1 to 0.1.
Although a thin mild steel plate of 3 mm has been adopted, an iron-nickel-based thin plate having low thermal expansion characteristics has recently been adopted.

[0003] Perforation by photoetching is performed by applying a photoresist to a thin metal plate having a smooth surface rolled by a normal work roll and securing a flow path of air when vacuuming a glass reference pattern. If the air flow path is not sufficient and not uniform, the adhesion of the glass reference pattern is poor, and the quality of the product perforated by etching is reduced.

[0004] Therefore, the thin plate for the shadow mask is rolled using a dull roll which has been subjected to fine unevenness processing such as shot blasting, electric discharge machining, or laser beam machining on the roll surface in order to secure the air flow path. You.

[0005] However, in a single pass rolling using a dull roll, before rolling by the dull roll, a large amount of the smooth surface when rolled remains on the surface of the sheet metal by a roll having a normal smooth surface, Due to the unevenness mechanism of the dull roll surface, the area occupation ratio of the surface exhibiting the unevenness transferred to the metal surface is small and lacks uniformity of the surface properties, so that the air flow path at the time of evacuation is not sufficiently and uniformly secured. .
Therefore, the adhesion of the glass reference pattern is still insufficient, and the quality of the product perforated by etching is still insufficient.

Japanese Patent Application Laid-Open No. 2-192802 proposes a "method of manufacturing a metal sheet for a shadow mask" as an example of the above countermeasure. Here, by performing the final rolling of 3 to 5 passes with a roll subjected to dull processing,
The area occupation ratio of the uneven surface of the steel sheet is set to 80%.

[0007]

However, the technique disclosed in Japanese Patent Application Laid-Open No. 2-192802 described above is
As described in the embodiment, the rolling reduction per pass is as low as 0.5 to 3%, and in order to obtain a predetermined plate thickness,
The number of passes is too large and inefficient. Further, the uniformity of the roughness in the longitudinal direction of the coil is not sufficient, and it is still insufficient to prevent uneven etching.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and eliminates non-uniformity of roughness in the longitudinal direction of a coil of a rolled thin plate, enables uniform etching, and eliminates etching unevenness. An object of the present invention is to provide a method of manufacturing a metal sheet for a shadow mask.

[0009]

In order to achieve the above object, the present invention relates to a pair of rolls dulled to 0.8 to 1.6 μm Ra having a unit width load of 0.05 to 2.00 T.
roll contact in the range of on / mm, 1000 rotations to 1
A method of manufacturing a thin plate for a shadow mask, comprising: performing a final rolling at a rolling reduction of 8 to 40% by using a pair or a plurality of pairs of rolls that have been subjected to an idle rotation process of 0000 rotations. It is.

The reasons for limiting the present invention will be described below. (1) The roll before overturning used in the present invention is 0.8 to 1.6.
It has been dulled to μmRa. When the roughness of the roll exceeds 1.6 μmRa, the roughness of the thin plate after rolling through the dull roll is 0.8 μmRa, regardless of the number of rolling operations performed on the dull roll.
And the defective etching rate exceeds 5%. on the other hand,
If the roll roughness is less than 0.8 μm Ra, the number of rolling
Thickness of thin plate is 0.3μm even when processing over 000 rotations
It becomes less than Ra, and the etching failure rate exceeds 5%.

(2) In the present invention, a pair of rolls dulled as described above are loaded with a unit width load of 0.05 to 2.00 To.
Roll contact in the range of n / mm, 1000 rotations to 10
The idle rotation process of 000 rotations is performed. As shown in FIG. 2 of the embodiment described later, the roll roughness after idling at 1000 Ton / mm or more and at 1000 rotations becomes substantially constant. By setting the maximum value of the width load to 2.00 Ton / mm, excessive removal of the roll unevenness is avoided. Further, by setting the upper limit of the number of times of the idling process to 10000 times, the fatigue of the roll is avoided.

By the above-described rolling process, unnecessary unevenness of the roll is corrected before rolling, and the number of times of the idle rolling process is set to 1000 times or more so that the roll roughness does not change. The thin plate rolled using this dull roll has a surface roughness of 0.3 to
It satisfies the range of 0.8 μm Ra, and the variation in roughness in the longitudinal direction (difference in roughness between top and bottom) is 0.05 μm.
It can be within mRa.

(3) In the present invention, the final rolling is carried out at a rolling reduction of 8 to 40% using the dull roll subjected to the above-mentioned rolling treatment. As shown in FIG. 3 of the embodiment described later, if the rolling reduction is less than 8%, it is difficult to stabilize the transfer (printing ratio) to a thin rolled sheet in the range of 70 to 80%. The reason why the upper limit is set to 40% is that the print ratio is flat, and conversely, a decrease in mechanical property values due to work hardening (elongation decrease, excessive hardness, etc.) occurs.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing the steps of one embodiment of the present invention.
In the drawing, reference numeral 1 denotes a roll dulling step, and 2 denotes an idle rolling process of the dulled roll.

In general, as a material, a thin plate for a shadow mask is formed by continuous casting step 3, hot rolling step 4, pickling step 5, cold rolling step (rough rolling) 6, annealing step 7,
And it manufactures through the final cold rolling process (finish) 8.

In this case, the dull roll used in the final cold rolling step (finishing) is generally off-line in the dulling step 1,
A dulling process is performed on the roll surface, in which fine irregularities are formed by shot blasting, electric discharge machining, laser beam machining, or the like. In the present invention, as described above, 0.8 to 1.6 μm suitable for the surface roughness of the shadow mask thin plate.
Dull processing to Ra. The dulled roll is subjected to the idling process in the idling process step 2 as shown by the thin arrow, and the processed dull roll is used for the final cold rolling step 8.

FIG. 2 is a diagram showing the relationship between the roll roughness and the number of times of idling. In the figure, it can be seen that the roll roughness after the idling process of 1,000 rotations at 0.05 Ton / mm or more is almost constant. Here, ○ indicates a width load of 0.1 ton / mm, and ● indicates a width load of 0.03 ton / m.
The marks m and Δ indicate the case where the width load is 0.05 ton / mm.

The maximum value of the width load is 2.00 Ton / m
By setting it to m, excessive removal of the unevenness of the roll is avoided. Further, by setting the upper limit of the number of times of the idling process to 10000 times, the fatigue of the roll is avoided.

By the above-described rolling process, unnecessary unevenness of the roll is corrected before rolling, and the number of times of the rolling process is set to 1000 times or more so that the roll roughness does not change. As a result, the thin plate rolled by using the dull roll satisfies the surface roughness range of 0.3 to 0.8 μmRa required for the shadow mask material, and has a variation in roughness in the longitudinal direction (top and bottom). Bottom roughness difference)
Can be set within 0.05 μmRa. That is, it is possible to eliminate the initial wear of the roll due to the rolling of the thin plate, and to make the unevenness of the roughness in the longitudinal direction of the rolled coil less than 0.05 μmRa.

The final rolling is performed in the final rolling step 8 at a rolling reduction of 8 to 40% by using the dull roll subjected to the above-described rolling treatment. FIG. 3 is a diagram showing the relationship between the reduction ratio and the printing ratio (the ratio of roll roughness to plate roughness). As is clear from the figure, if the rolling reduction is less than 8%, it is difficult to stabilize the transfer (printing ratio) to the thin plate of the roll roll in the range of 70 to 80%. The reason why the upper limit is set to 40% is that the printing rate is flat, and conversely, a decrease in mechanical property values due to work hardening (elongation rate reduction, excessive hardness, etc.) occurs.

That is, a pair of rolls dulled to 0.8 to 1.6 μm Ra are loaded with a unit width load of 0.05 to 2.00 To.
Roll contact in the range of n / mm, 1000 rotations to 10
The surface roughness required as a thin plate for a shadow mask is obtained by performing final cold rolling at a rolling reduction of 8 to 40% using a pair or a plurality of pairs of rolls that have been subjected to an idling process of 000 rotations. It can be manufactured uniformly to 0.3 to 0.8 μmRa.

Table 1 shows the experimental results according to the present invention. Table 2
Shows the rolling schedule at that time. Here, a Fe-36% Ni alloy was used as a typical material.

[0023]

[Table 1]

[0024]

[Table 2]

The following is clear from Table 1.
The roughness in the longitudinal direction of rolling using a conventional roll that does not undergo idling greatly differs between the top, the center, and the bottom. The roll roughness before rolling was 1.6 μm Ra.
In the case of exceeding, regardless of the number of times of rolling, the thin plate roughness after rolling exceeds 0.8 μmRa, and the defective etching rate exceeds 5%.

The roll roughness before rolling is 0.8 μmR
If it is less than a, even if the number of rollings is 1000 rotations or less, the thin plate roughness is less than 0.3 μmRa, and the etching failure rate exceeds 5%. On the other hand, within the range of the present invention, the plate roughness is 0.3 to 0.8 μm Ra, the variation in the coil longitudinal direction is also within 0.05 μm, the etching failure rate is less than 5%, It shows an etching property.

[0027]

As described above, according to the present invention, in the final rolling step of the production of a thin plate for a shadow mask, a specific operation of rolling using a dull roll which has been subjected to idling is performed by a simple operation of rolling. Since the surface roughness of the thin plate required as a thin plate is 0.3 to 0.8 μm Ra, and the difference in roughness between the coil top, center and bottom can be maintained within 0.05 μm, as a result, the etching property Can be easily and inexpensively obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing the steps of one embodiment of the present invention.

FIG. 2 is a diagram showing the relationship between the roll roughness and the number of times of idling according to the present invention.

FIG. 3 shows a relationship between a reduction ratio and a printing ratio in a final rolling step according to the present invention.

[Explanation of symbols]

 1 Roll dulling process 2 Dulling roll idling process 3 Continuous casting process 4 Hot rolling process 5 Pickling process 6 Cold rolling process (rough rolling) 7 Annealing process 8 Final cold rolling process (finish)

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B21B 1/22 B21B 3/00-3/02 H01J 9/14 H01J 29/07

Claims (1)

(57) [Claims] 1. A pair of rolls dulled to 0.8 to 1.6 μm Ra are loaded with a unit width load of 0.05 to 2.00 Ton /
roll contact in the range of 1000 mm
A method of manufacturing a thin plate for a shadow mask, comprising: performing a zero-rotation rolling process; and performing final cold rolling at a reduction ratio of 8 to 40% using a pair or a plurality of pairs of the rolls subjected to the slipping process.