JPH02133104A - Manufacture of shadow mask stock - Google Patents

Abstract

PURPOSE:To improve vacuum adhesion of a pattern and to prevent fouling of a shadow mask stock by performing cold rerolling the coil-shaped shadow mask stock after slitting. CONSTITUTION:A shadow mask stock is slitted to have a product width, cold rolled, and is introduced to an etching line after shape straightening. In the etching line, a flat mask is produced by adhering patterns after degreasing and applying resist, and the performing exposure, development and etching. An evacuation time is reduced and adhesion is improved by cold rolling the stock after slitting.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing a shadow mask material for a color television cathode ray tube.

[Background of the invention]

Shadow masks are used as color selection electrodes in color television cathode ray tubes. Low carbon Al-killed steel and rimmed steel have been used as materials for shadow masks, but recently an amber alloy material (Fe-36%Ni) with low thermal expansion characteristics has also begun to be used.

The manufacturing process of the shadow mask is generally as follows. First, through processes such as melting and casting of the material and appropriate rolling,
Then, a shadow mask material having a predetermined thickness is manufactured by final cold working. The shadow mask material is etched and perforated to form a flat mask. The flat mask is annealed to give it press formability, and is then pressed into a spherical shape. The spherical mask is subjected to a blackening process to become a shadow mask. There is also a method in which annealing to impart press formability is performed immediately after final rolling, and this is called a pre-annealing method.

To explain in more detail, first, taking low-carbon Al-killed steel as an example of a method for producing a shadow mask material, the steel is melted in a converter and then cast into an ingot.After casting, hot rolling and cold rolling are performed to form an open coil. Decarburized by annealing,
Thereafter, final cold rolling is performed to a predetermined thickness. Thereafter, it is slit to obtain a shadow mask material having a predetermined width. In the case of invar material, it is similarly melted, then cast, forged, and then hot rolled. After that, cold rolling and annealing are repeated at appropriate times, and the final cold rolling is made to a specified thickness, and the same is slit to a specified width. You can obtain the shadow mask material. After degreasing, the shadow mask material is coated with photoresist on both sides, the pattern is vacuumed to completely adhere to the material, exposed to light, baked and developed, then etched and perforated with an etching solution mainly containing ferric chloride. Cut into flat masks.

The flat mask is annealed in a non-oxidizing atmosphere to impart press formability (in Blair Annealing this annealing is performed on the final cold rolled material before etching). After leveling, it is spherically molded into a mask shape using a press.

Finally, the spherical mask is degreased and then subjected to a blackening treatment in a steam or combustion gas atmosphere to form a black oxide film on the surface. In this way, a shadow mask is produced.

[Prior art and its problems]

The above is the general manufacturing process for shadow masks, but recently there has been a movement to improve the efficiency of this shadow mask manufacturing process, and there is a strong demand for improved efficiency in the manufacturing of flat masks in particular. .

Conventionally, when manufacturing shadow mask materials, 0.
After rolling to a thickness of 3 mm or less, the material was slit to a product width suitable for manufacturing a flat mask, and then the shadow mask material was etched to form holes for electron beam passage. However, during this slitting process, burrs or protrusions called paris appeared on the slit end surface.
These protrusions not only obstructed the adhesion of the pattern by vacuuming after the degreasing and resist coating processes, but also caused a serious problem in that the rubber rolls used in each manufacturing process were scraped off, and the scraps caused stains. In particularly severe cases, the patterned glass could even break. The occurrence of cracks also depends on the slitting conditions, so if you increase the frequency of replacing the slitter blades or set detailed conditions for each product, it can be reduced to a certain extent, but this does not affect the material manufacturing. It was extremely inefficient and the drop in productivity was undeniable. [Structure of the Invention] The present invention has been made in view of the above points, and provides a method for manufacturing a shadow mask material that is unprecedented.

That is, the present invention provides a method for producing a shadow mask material characterized by performing re-cold rolling of a coiled shadow mask material after slitting, and a method for producing a shadow mask material with a total rolling reduction of 10% or more after slitting the coiled shadow mask material. The present invention relates to a method for producing a shadow mask material, which is characterized by performing re-cold rolling.

[Specific description of the invention]

Next, a method for manufacturing the shadow mask material of the present invention will be described.

Figure 1 shows a typical slit-up cross-section. 1st
The protrusions shown in the figure obstructed the vacuuming process when the pattern was adhered, or were cut or peeled off midway through, causing scratches and stains on the shadow mask material. FIG. 2 shows a cross-sectional view of the end face after cold rolling with a total reduction of 50% after slitting, and the end face is rounded and no protruding foreign matter such as ribs is observed.

Furthermore, due to cold rolling, the end faces are subject to a greater reduction in plate thickness due to etch drop than the center of the width, and the thinner plate thickness at the edges is thought to reduce the causes of various problems. In order to reduce the fringing after slitting by cold rolling, a total rolling reduction of 10% or more is desirable and has a great effect. The upper limit of the rolling reduction rate is 90% in total. The reason is that if the width is exceeded, the width will shrink.
This is because it becomes difficult to manage width accuracy. Also, heat treatment may be performed in the middle of this rolling reduction, for example, slit -1
Even when manufacturing in the process of 1st cold rolling, 1st heat treatment and 2nd cold rolling, the reduction ratio of 1st cold rolling and 2nd cold rolling is 10%.
More than that is fine. The material of the present invention will be explained below with reference to Examples.

〔Example〕

Using an amber material (Fe-36%Ni) as the material, slits were made in various thicknesses as shown in Table 1 to obtain the product width, and then cold rolling (heat treatment was applied in some cases). All the plates were made to have a thickness of 0.15 mm, and after shape correction, they were put into an etching line.

On the etching line, after degreasing and applying resist, the pattern was adhered, exposed, developed, and etched to produce a flat mask. The results are also listed in Table 1.

As is clear from Table 1, cold rolling after slitting shortens the evacuation time and improves adhesion. This means that the rolling reduction is 10% as shown in Inventive Examples Nα1 to 6.
The above is more effective.

Comparative Example &8 was subjected to etching after slitting, but the glass broke when the pattern was vacuum-adhered. [Effects of the Invention] As described above, by cold rolling the shadow mask material before the etching process to remove paris, the vacuum adhesion of the pattern was improved and the shadow mask material was free from stains. This can greatly contribute to improving efficiency and quality in the production of shadow mask materials for color television cathode ray tubes. Table 1

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram showing the state of the end cross section after slitting, and FIG. 2 is a schematic explanatory diagram showing the state of the end cross section after cold rolling with a post-slitting reduction ratio of 50%. In the figure, 1 is the burr, and 2 is the material itself. Chilled grass / l'E) ￥ 2m

Claims (2)

[Claims] (1) A method for producing a shadow mask material, which comprises slitting a coiled shadow mask material and then cold rolling it again. (2) A method for producing a shadow mask material, which comprises slitting the coiled shadow mask material and then cold rolling it again at a total rolling reduction of 10% or more.