JP2003183779A - Raw material for shadow mask for color picture tube, shadow mask, and picture tube - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a material for a shadow mask having a uniform and excellent magnetic property throughout a coil, a manufacturing method therefor, the shadow mask using the cold-rolled steel sheet, and a picture tube incorporating the shadow mask therein. <P>SOLUTION: A method for manufacturing the raw material for the shadow mask in the color picture tube is characterized by heat-treating a low-carbon alloy steel strip comprising 0.60 wt.% or more Mn, and 0.002-0.012 wt.% Al, and the balance Fe with unavoidable impurities, at a temperature where no recrystallization takes place, to correct the shape. The shadow mask is characterized by using the raw material. The picture tube is characterized by incorporating the shadow mask therein. <P>COPYRIGHT: (C)2003,JPO

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 for a color picture tube, a shadow mask and a color picture tube incorporating the same. More specifically, the present invention relates to a material for a shadow mask for a color picture tube having excellent tensile strength and high temperature creep strength, a shadow mask and a color picture tube incorporating the same.

[0002]

2. Description of the Related Art Conventionally, a so-called curved surface (dome type) cathode ray tube in which a shadow mask having a slightly curved mask surface is attached to a frame frame by welding has been used for a shadow mask type color picture tube. . Since the shadow mask material used in such a conventional method is formed into a dome shape, importance has been attached to press formability, shape fixability for maintaining the shape at the time of pressing, and the like.

[0003]

The curved surface cathode ray tube has a problem that eyes are easily fatigued due to irregular reflection of external light rays such as illumination, and therefore it has been desired to flatten the cathode ray tube. However, in the shadow mask method, if the flat surface of the CRT progresses, the slightly curved mask surface used in the conventional CRT may not be flat. Therefore, it is desired to develop a material for a shadow mask which can be made flat by completely flattening the mask surface in a conventional shadow mask cathode ray tube. Shadow mask method In the case of a cathode ray tube, several methods have been proposed for flattening the mask surface, but it is said that the stretchable shadow mask method that applies tension in the vertical direction of the shadow mask is one of the industrially promising methods. It is being appreciated. The spread-type shadow mask is formed by joining a shadow mask element, which has been punched with a predetermined dot hole pattern by etching, to the frame frame in a direction opposite to the spreading direction with pressure applied to the frame by welding or the like. The applied pressure is removed, and the tension is formed by the restoring force of the frame. After that, in order to prevent generation of secondary electrons, heat radiation, generation of rust, etc., 45
The blackening treatment is performed at 0 to 470 ° C. for 10 to 20 minutes. The material properties required for such a spread-type shadow mask are not only excellent in etching property, but also required to be excellent in tensile strength, particularly high temperature creep property during blackening treatment. That is, in the blackening process, since the heat treatment is performed while the tension due to the restoring force of the frame frame is applied to the shadow mask, the creep phenomenon occurs in the shadow mask body due to heat and tension, and the shadow mask body stretches. is there. In this way, when the television set was completed by incorporating the shadow mask element with large creep elongation and low tension into the cathode ray tube, and when the volume was increased during operation, the vibration of the shadow mask element increased. It was a cause of screen color misregistration. Conventionally, in order to solve such a problem, the pressure applied by the frame is adjusted.
Although measures such as increasing the rigidity of the shadow mask material to make it stronger and providing cushions on the speaker part and the cathode ray tube support part have been considered, the sufficient effect has not been obtained yet. Japanese Patent No. 2548133 proposes an aperture grill type steel plate material for a mask, but contains 40 to 100 PPM of N and 0.20 to Mn of Mn.
This is a proposal to reduce the creep elongation during blackening treatment due to the high strength and high temperature creep characteristics of the ultra low carbon steel sheet containing 0.60% by weight. In this case, since the solute atom N has a remarkably smaller atomic radius than the solvent atom Fe, N forms an interstitial solid solution in the Fe crystal lattice.
Create a Cottrell atmosphere. At high temperatures such as blackening temperature, N in Fe has a high diffusion rate, so creep elongation, that is, N atoms gather around dislocation creep, forming a Cottrell atmosphere like a cloud, and dislocation creep movement. It is believed that this has the effect of reducing creep elongation because it has the effect of suppressing JP-A-1
1-2222628 is also a proposal based on the same technical principle as the above-mentioned Japanese Patent No. 2548133, and N is 100 to 17
By including 0 PPM and 0.10 to 0.60% by weight of Mn, overlapping of the claims with Japanese Patent No. 2548133 is avoided. The object of the present invention is to
The purpose of the present invention is to provide a color picture tube that is compatible with the above-mentioned flat screen cathode ray tube. That is, by taking measures to reduce the creep elongation of the stretchable slot type shadow mask by increasing the rigidity of the shadow mask material. It proposes a method for solving problems such as color shift. That is, the most important technical problem disclosed by the present invention is to improve creep characteristics by setting Mn to 0.60% by weight or more, and Al to 0.002-
By setting the content to 0.012% by weight, the precipitation of AlN is suppressed and the creep improving effect of solid solution N is improved without lowering the inclusion level. Further, by performing the heat treatment at a temperature at which recrystallization is not performed, the shape does not change even if the blackening treatment is performed, and the color shift of the screen can be eliminated. Furthermore, by imparting an appropriate surface roughness before heat treatment at a temperature at which recrystallization is not performed, it is possible to further improve the adhesion to the resist and the vacuuming property. The present inventors have arrived at the proposal of the present invention by finding out the Mn and Al content regulating effect, the heat treatment and the surface roughness imparting treatment as described above.

[0004]

A material for a shadow mask for a color picture tube according to the present invention contains Mn in an amount of 0.60% by weight or more, contains Al in an amount of 0.002 to 0.012% by weight, and has a balance of Fe and inevitable impurities. The low carbon alloy steel strip made of is subjected to shape modification treatment by heat treatment at a temperature that does not cause recrystallization. The material for a shadow mask for a color picture tube of the present invention contains 0.03% by weight or less of C and 0.60% by weight of Mn.
In the low carbon alloy steel strip containing the above, 0.002 to 0.012% by weight of Al, the balance Fe and unavoidable impurities,
It is characterized in that the shape correction process is performed by heat treatment at a temperature at which recrystallization is not performed. The material for a shadow mask for a color picture tube of the present invention contains 0.60 wt% or more of Mn, 0.002 to 0.012 wt% of Al, and a balance of Fe and unavoidable impurities in a low carbon alloy steel strip, Surface roughness Ra (J
The surface roughness is imparted so that IS B 0601) is 0.2 to 0.8 μm, and the shape is corrected by heat treatment at a temperature at which recrystallization is not performed. The material for a shadow mask for a color picture tube of the present invention has a C content of 0.03.
A low carbon alloy steel strip containing not more than 10% by weight, not less than 0.60% by weight of Mn, 0.002 to 0.012% by weight of Al, the balance being Fe and unavoidable impurities, and having a surface roughness Ra (J
The surface roughness is imparted so that IS B0601) is 0.2 to 0.8 μm, and the shape is corrected by heat treatment at a temperature at which recrystallization is not performed. It is desirable that the material contains 0.01% by weight or less of Si and 0.10% by weight or less of P,
It is desirable to contain N in an amount of 0.010 to 0.020 wt% and S in an amount of 0.10 wt% or less. The shadow mask for a color picture tube of the present invention is characterized by using the material for a shadow mask described in any one of the above. A color picture tube of the present invention is characterized by incorporating the shadow mask. In the color picture tube of the present invention, the shadow mask is
It is characterized in that it is attached to the frame in a state where tension is applied in the vertical direction. The color picture tube of the present invention is characterized in that the shadow mask is attached to the frame in a state where tension is applied in the vertical and horizontal directions. In such a color picture tube, it is desirable that the tension in the horizontal direction is smaller than the tension in the vertical direction. The shadow mask material of the present invention has a load stress of 196 N / mm ² and an elongation of 0.3% when held at 450 ° C. for 60 minutes.
It is characterized in that it is configured as follows. The shadow mask of the present invention is such that the load applied to the shadow mask after being incorporated in a color picture tube is 196 N / mm ² , and the elongation when held at 450 ° C. for 60 minutes is 0.5% or less. It is characterized by being

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The shadow mask of the present invention comprises a shadow mask material produced by adjusting components to be contained,
It is fixed (for example, welded) to the frame with a large amount of tension applied in the vertical direction. Further, the shadow mask of the present invention is slackened even after the heat treatment is performed in a state where a slight tension smaller than that in the vertical direction is applied to the horizontal direction of the frame, and the shadow mask itself slackens to generate wrinkles. You can keep the state that you do not do,
It has sufficient high temperature creep strength.

The low carbon steel used as the material for the shadow mask of the present invention is preferably one that has been subjected to decarburization and denitrification treatment using a vacuum degassing method to reduce carbides and nitrides in the steel and hot rolled. . First, the types of elements contained in the steel used for the material of the shadow mask of the present invention and the reasons for limiting the content will be described.

C forms a solid solution in steel to increase the material hardness,
Since the tensile strength and the creep strength are improved, it is necessary to add it. However, if the amount of C is large, the carbides increase and the etching characteristics are hindered. Therefore, the upper limit is made 0.03% by weight. Is preferred. The lower limit is vacuum degassing or open coil annealing in a box annealing furnace (O
The content is preferably 0.0001% by weight, which can be practically reduced by CA). More preferably 0.0002
The content is at least wt%, more preferably 0.00
The content is 03% by weight or more.

Mn is an important component of the present invention, and in order to improve the creep characteristics as a spread type slot type shadow mask, the higher the content of Mn is, the lower limit is set to 0.60% by weight. The upper limit is preferably 1.0% by weight or less from the viewpoint of manufacturing cost and etching property.

Si impairs the etching property and deteriorates the adhesion of the blackened film. Therefore, the smaller the content, the more preferable, and the content is preferably 0.01% by weight or less.
S is segregated at the crystal grain boundaries, significantly impairs the etching characteristics, and causes embrittlement of the material. Therefore, the S content is preferably small, and is preferably 0.10 wt% or less. More preferably, the content is 0.05% by weight or less.

Al, like Mn, is an important element of the present invention, is used as a deoxidizing agent in the steelmaking process, and has the effect of improving the cleanliness of steel. Therefore 0.002% by weight
The above content is preferable. The content is more preferably 0.003% by weight or more. On the other hand, if a large amount of Al is contained, embrittlement due to solid solution hardening occurs, and not only the etching characteristics deteriorate, but also AlN is formed by combining with the solid solution N in the steel to reduce the solid solution N and improve the creep characteristics In order to deteriorate, the upper limit is made 0.012% by weight or less.

As mentioned above, N is required to be added because it forms a solid solution in steel to increase the material hardness and the tensile strength and creep strength. Furthermore, in addition to forming a nitride having a high hardness, the nitride is finely dispersed in the crystal grains to prevent the dislocation creep from moving, so that the creep strength is particularly improved. Therefore, the content is preferably 0.010% by weight or more. The content is more preferably 0.012% by weight or more. On the other hand, when the amount of N is large, the amount of nitride increases excessively and the material becomes brittle, so the content is preferably 0.02% by weight or less. The content is more preferably 0.017% by weight or less.

Cu is required to be added because it forms a solid solution in steel to increase the material hardness and the tensile strength and creep strength. Therefore, the content is preferably 0.001% by weight or more. The content is more preferably 0.002% by weight or more, and further preferably 0.003% by weight.
It is the above content. On the other hand, when the amount of Cu is large, the etching rate is lowered and the etching liquid is contaminated. Therefore, the content is preferably 0.1% by weight or less. More preferably, the content is 0.08% by weight or less.

Cr is required to be added because it forms a solid solution in steel to increase the material hardness and the tensile strength and creep strength. Further, Cr has a strong property of reacting with solid solution nitrogen (N) remaining in the steel to form a nitride such as CrN, and thus has a nitride forming and stabilizing effect. As a result, by significantly reducing the blowholes in the slab and forming and dispersing fine nitrides,
Creep strength is significantly increased. It is speculated that this is because the resistance to creep elongation accompanying the movement of dislocations increases. Therefore, the lower limit of the amount of Cr added is 0.001% by weight.
The above content is preferable. The content is more preferably 0.002% by weight or more, and further preferably 0.003% by weight or more. On the other hand, when the amount of Cr is large, carbides are formed and the magnetic properties are impaired.
The content is preferably 0.1% by weight or less. More preferably, the content is 0.09% by weight or less. More preferably, the content is 0.08% by weight or less.

Since P hinders the etching property, the upper limit is 0.10% by weight.

Next, a method of manufacturing a thin steel plate as a shadow mask material of the present invention will be described. The molten metal having the above composition obtained by the usual melting method is vacuum degassed or
A hot rolled sheet is obtained by performing deoxidation treatment with l, Si, etc., and performing continuous casting and hot rolling steps. In the pickling step, after descaling, cold rolling is performed to a plate thickness of 0.2 to 0.8 mm. Then, after softening by annealing, finish processing is performed by cold rolling to a predetermined plate thickness of 0.05 to 0.20 mm. For the annealing treatment, either a box-type annealing furnace or a continuous annealing furnace may be used. Furthermore, after finishing by cold rolling, heat treatment is performed in a temperature range in which no surface roughness is applied and recrystallization is not performed, or after surface roughness is applied, heat treatment is performed in a temperature range in which recrystallization is not performed. Give. The temperature range in which recrystallization does not occur varies depending on the steel composition, but is preferably in the range of approximately 450 to 550 ° C. In addition,
The surface roughness imparting treatment may be performed by a well-known method, for example, it may be performed in a temper rolling step, and a predetermined plate thickness of 0.05
Up to 0.20 mm may be performed during cold rolling.
Also, before and after performing heat treatment in a temperature range that does not recrystallize,
A mechanical tension leveler or a hydro-tension leveler may be used to correct the shape of the plate. Surface roughness Ra of cold-rolled sheet (JIS B060
1) is preferably in the range of 0.2 to 0.8 μm. The range of 0.4 to 0.6 μm is more preferable. If it is less than 0.2 μm, the adhesion to the resist is poor, and if it exceeds 0.8 μm, the adhesion is too good, and the resist at the portion to be dissolved during development tends to remain.

Next, the shadow mask of the present invention will be described. A water-soluble casein resist was applied to both surfaces of the shadow mask material shown in Table 1 and, after drying, the resist was patterned on both surfaces of the material using a glass plate having a pair of front and back patterns. Next, exposure, hardening treatment, and baking treatment are performed, and then both surfaces of the patterned resist have a liquid temperature of 60 ° C. and a specific gravity of 48 ° B.
Etching was carried out by spraying the ferric chloride solution of e as an etching solution from a spray. After etching, wash with water,
The resist was peeled off with an alkaline solution, washed and dried to prepare a shadow mask.

Next, the shadow mask of the present invention is framed.
The state of being attached to the frame will be described. Shadow mass of the present invention
Is fixed to the frame with tension applied.
It There are various types of this fixing method, but the welding method is also
It is often used. When fixing, first
Force the center of the frame above and below the frame inward
Slightly bend and fix the shadow mask in this state
To do. And the upper and lower frames that have been bent inside
Undo (release the forcible power), Shadowmass
The vertical tension is applied to the rack. Also on
For fixing the shadow mask to the frame frame
The tension applied to the left and right is less than the tension applied vertically.
It is also preferable to load in the direction. Color image of the present invention
It is desirable that the pipe be loaded with strong tension in the vertical direction.
Yes. Not only load vertically but also tension horizontally
Is applied, tension is applied vertically,
It is possible to prevent wrinkles from occurring in the shadow mask. Shi
However, apply too much tension to the left and right sides of the shadow mask.
Loaded in the direction of the shadow mask
This is not preferable because it causes deformation of the dot holes. Shadow above
The vertical stress applied to the mask is several hundred N in the actual machine.
/ Mm ^TwoIs in a stressed state, but tested
196 N / mm^TwoAnd hold at 450 ° C for 60 minutes
If the elongation when held is 0.5% or less, a picture tube is in use
Problems such as slack in the shadow mask occur
do not do. In addition, a so-called shadow mask element before blackening treatment
In the material state, a heat treatment process called blackening treatment after material formation
In view of the fact that the
It is desirable to keep it. Therefore, the shadow mask
196 N / mm as a test material^TwoLoad stress of
The elongation when held at 450 ° C for 60 minutes is 0.3% or less.
If so, the shadow mask becomes loose during use of the picture tube
Such a problem does not occur.

[0018]

The present invention will be described in more detail with reference to the following examples. Table 1 shows the chemical composition when steels (A to H) having different chemical compositions were vacuum degassed and the molten slab was hot-rolled into a hot rolled sheet of 2.5 mm. Show. These hot-rolled sheets were washed with sulfuric acid and then cold-rolled to obtain cold-rolled sheets with a thickness of 0.35 mm. After that, annealing was performed using a continuous annealing furnace, and cold rolling was performed to obtain a plate thickness of 0.10 mm. During this cold rolling, the surface roughness Ra of the cold rolled sheet was adjusted by imparting a certain surface roughness to the rolling roll. After imparting a constant surface roughness Ra, a heat treatment was performed to the extent that recrystallization was not performed. Further, after the cold rolling, the roughness imparting treatment was performed again, and the heat treatment was performed to the extent that recrystallization was not performed. The heat treatment temperature in Table 1 indicates a heat treatment temperature at which recrystallization is not performed. In Tables 1 and 2, sample numbers C, D, G
And H were subjected to surface roughening treatment by temper rolling. Sample numbers A, B, E and F provided surface roughness during cold rolling.

Table 2 shows the results of the characteristic tests for the test materials thus obtained. Tensile test using an Instron type tensile tester, creep elongation using a creep tester (manufactured by Tokai Seisakusho), load stress 196 N / m
m ² and elongation (%) when held at 450 ° C. for 60 minutes in the atmosphere, and load stress of 196 N / mm ² applied, and when held at 450 ° C. for 20 minutes in the atmosphere, repeated 3 times Both elongation (%) was measured and evaluated. This creep strength test evaluation is defined by the following criteria. That is, the reason why the creep elongation in the column “Characteristics of shadow mask material” in Table 2 is set to “0.3% or less” is that the shadow mask is blackened after being welded to the frame. Assuming that heat treatment is applied,
Establishing test conditions for the shadow mask material so that the shadow mask can be kept tension-free even after the shadow mask is attached to the frame with tension applied after the blackening treatment. It is a thing. As this condition, the creep stress after applying a load stress of 196 N / mm ² to the shadow mask material and holding it at 450 ° C. for 60 minutes was measured. This is because if the elongation is 0.3% or less, the shadow mask material can be used as a flat mask shadow mask even after the shadow mask is incorporated in the picture tube.

[0020]

[Table 1]

The surface roughness Ra was measured according to JIS B 0601. Regarding the adhesion to the resist, after applying water-soluble casein so that the thickness after drying is 5 to 6 μm, a cross-cut is made with a cutter to reach the steel plate, and a forced peel test with cellophane tape is performed. went. If there is no peeling at all, it is judged as pass (indicated by ◯ in Table 2), and if there is any peeled part, it is rejected (indicated by x in Table 2).
And

Further, in the actual device of the color picture tube,
Following the blackening treatment, a heating treatment such as a baking treatment and a glass sealing treatment which are performed after being incorporated in the picture tube is performed. Therefore, the creep elongation of the shadow mask is assumed to be larger than that of the shadow mask material. Therefore, in the present invention, in view of the manufacturing process of the above-mentioned actual machine, the elongation when the load stress of 196 N / mm ² is applied to the shadow mask material and the heating / cooling cycle of 20 minutes at room temperature and 450 ° C. is repeated three times. It is set to be 0.6% or less. This is because if the elongation is 0.6% or less, the shadow mask material can be used as a flat mask shadow mask even after the shadow mask is incorporated in the picture tube.

From Table 2, since the product of the present invention is excellent in any of the above-mentioned characteristics, a symbol of ◯ is shown in the judgment column as a comprehensive evaluation. On the other hand, the comparative example products that do not fall within the scope of the present invention are inferior in any of the above-mentioned characteristics, and therefore, the symbol X is shown as a comprehensive evaluation.

[0024]

[Table 2]

[0025]

The material for a slot type shadow mask for a color picture tube of the present invention has excellent etching properties, and the slot type shadow mask and a picture tube incorporating the same have excellent tensile strength, high temperature creep strength and adhesion to a resist. Therefore, it is possible to flatten the mask surface in a conventional shadow mask type cathode ray tube.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Jun Kuri             1302 Higashitoyoi, Kudamatsu City, Yamaguchi Prefecture Toyo Kohan Co., Ltd.             Shimomatsu Factory F-term (reference) 4K037 EA01 EA04 EA05 EA15 EA18                       EA23 EA25 EA27 EB02 EB05                       EB08 FH08                 5C031 EE05 EE11

Claims (15)

[Claims] 1. A low carbon alloy steel strip comprising Mn in an amount of 0.60% by weight or more, Al in an amount of 0.002 to 0.012% by weight, and the balance being Fe and inevitable impurities. A material for shadow masks for color picture tubes characterized by being subjected to correction processing. 2. C of 0.03% by weight or less and Mn of 0.6
A low carbon alloy steel strip consisting of 0% by weight or more and 0.002 to 0.012% by weight of Al and the balance Fe and unavoidable impurities is subjected to shape modification treatment by heat treatment at a temperature at which recrystallization does not occur. Material for shadow masks for color picture tubes. 3. A low carbon alloy steel strip containing 0.60% by weight or more of Mn, 0.002 to 0.012% by weight of Al, the balance being Fe and unavoidable impurities, and having a surface roughness Ra (JI).
A material for a shadow mask for a color picture tube, which is subjected to a surface roughness imparting treatment such that S B 0601) is 0.2 to 0.8 μm, and is subjected to a shape correcting treatment by a heat treatment at a temperature at which recrystallization is not performed. 4. A C content of 0.03% by weight or less and a Mn content of 0.6.
0% by weight or more, Al 0.002 to 0.012% by weight or less, and a surface roughness Ra (JIS B 0601) of 0.2 to 0.8 μm in a low carbon alloy steel strip composed of the balance Fe and unavoidable impurities. A material for a shadow mask for a color picture tube, which is subjected to a surface roughness imparting treatment so as to achieve a shape modification treatment by a heat treatment at a temperature that does not cause recrystallization. 5. The material for a shadow mask for a color picture tube according to claim 1, which contains Si in an amount of 0.01% by weight or less. 6. The shadow mask material according to claim 1, which contains 0.10% by weight or less of P. 7. The material for a shadow mask for a color picture tube according to claim 1, which contains 0.010 to 0.020% by weight of N. 8. The material for a shadow mask for a color picture tube according to claim 1, which contains 0.10% by weight or less of S. 9. A shadow mask for a color picture tube, which uses the material for a shadow mask according to claim 1. 10. A color picture tube incorporating the shadow mask of claim 9. 11. A color picture tube in which a shadow mask is attached to a frame while being vertically tensioned. 12. A color picture tube in which a shadow mask is attached to a frame in a state where tension is applied in the vertical direction and the horizontal direction. 13. The color picture tube according to claim 12, wherein the tension in the horizontal direction is smaller than the tension in the vertical direction. 14. The method according to claim 1, wherein the load stress is 196 N / mm ² and the elongation when held at 450 ° C. for 60 minutes is 0.3% or less. Material for the shadow mask of. 15. A load stress of 196 N / mm ² is applied to the shadow mask after it has been incorporated into a color picture tube, and then 4
A shadow mask which has an elongation of 0.6% or less when held at 50 ° C. for 60 minutes.