JP3288656B2 - Fe-Ni shadow mask material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material for an Fe-Ni-based shadow mask used as a material for a color television CRT or the like, for example, a photomask using an etching solution mainly containing a ferric chloride solution. We propose a low thermal expansion Fe-Ni-based shadow mask material with excellent press-formability without any visible unevenness or mottling (hereinafter referred to as "unevenness") during etching.

[0002]

2. Description of the Related Art Conventionally, a low carbon aluminum killed steel plate has been used as a shadow mask material. This steel plate
The steel sheet after the intermediate cold rolling is subjected to an appropriate strain relief by a continuous annealing or batch annealing furnace, and is subjected to a flaw removal if necessary. Then, the cold rolling and the temper rolling (final rolling) are performed. (Including). On the other hand, in recent years, low-thermal-expansion Fe-Ni-based alloy plates have attracted attention as materials for high-quality color television CRTs and displays. This Fe-Ni-based alloy plate has been developed as a substitute for a low-carbon aluminum-killed steel plate previously used as a shadow mask material. The reason why such Fe-Ni-based alloys are receiving attention is that
Compared to the low-carbon aluminum-killed steel sheet, it is superior in terms of preventing color misregistration, and is one of the indispensable materials especially for applications such as displays and large-sized televisions.

[0003] However, this Fe-Ni-based alloy has problems in photoetching properties and press formability. That is, it has been pointed out that the Fe-Ni-based alloy has a poor perforation shape at the time of photoetching and is more likely to cause a defect called stripe unevenness, as compared with aluminum killed steel. In particular, it has been found that such a defect called streaking causes streaky contrast unevenness in a white portion of an image in a color cathode ray tube, thereby significantly lowering the quality of a display. It is considered that the cause of the stripe unevenness is the presence of nonmetallic inclusions and the influence of segregation of components such as Ni. Therefore, it is effective to eliminate these causes in order to reduce streaking. However, even if all of these causes were removed, unresolved streaks still remain, so the inventors assumed that there was another factor and continued their research. In terms of press formability, the yield strength is larger than aluminum killed steel,
Since the Young's modulus is low, there is a problem that springback occurs at the time of press forming after forming the through hole after etching.

It is a primary object of the present invention to provide a material for an Fe-Ni-based shadow mask which finds the true cause of streak unevenness and mottling (whole unevenness) caused by poor etching and does not cause these. Further, according to the present invention, it is possible to provide a Fe-Ni-based shadow mask material having softening after annealing before press in a tube maker at a lower temperature (800 ° C. or lower) and having good press formability. it can. Further, according to the present invention, it is possible to provide an Fe-Ni-based shadow mask material having good etching piercing properties and a clear hole shape at the time of piercing. further,
According to the present invention, it is possible to reliably and inexpensively provide a material for a color cathode ray tube or a display having a clear image.

[0005]

Means for Solving the Problems The inventors obtained the following knowledge as a result of intensive studies on the problems, such as streaking, remaining in the prior art as a problem to be solved. That is,
It was found that the stripe unevenness or the like generated in the shadow mask material was caused by disorder of the orientation of individual crystal grains on the etched surface. The disorder of the orientation is caused by Ni segregation, non-metallic inclusions, residual mixed grain structure due to coarse grains generated during annealing, orientation of a specific texture, etc., and these elements are entangled with each other. Was found to occur. Furthermore, since the orientation of such crystal grains depends on the crystal orientation of the individual crystal grains, it is concluded that it is absolutely necessary to control the texture in order to prevent the occurrence of such stripes and the like. Reached.

In the production of a shadow mask,
There is pre-press annealing after etching and subsequent press forming, blackening process, but Fe-Ni alloy has higher proof stress and higher spring back than aluminum killed steel used conventionally, There is a problem that the springback at the time of press forming is large and so-called shape freezing property (press formability) is poor. As a countermeasure for this, attempts have been made to reduce the springback by lowering the 0.2% proof stress by performing molding at a warm temperature (about 200 ° C) during pressing. Furthermore, it is possible to regulate impurities and limit the formation of carbides and nitrides,
It has been found that it is also effective to improve the pressability by adding elements such as these (Japanese Patent Application Laid-Open No. 7-166278).

On the other hand, in order to improve the press formability, Mn reduction is required.
(For example, 0.05% or less) and that it is effective to control the relationship between low Mn and the amount of N.
No. 9-157800).

Therefore, the present invention aims at reducing the hardness and proof stress at the time of annealing before press and reducing the springback by controlling the texture before press based on the above various findings. Further, in the present invention, as a shadow mask material, in order to excel the etching piercing property and to improve the hole shape after piercing, in addition to the above-described control, it is also desirable to control the roughness of the product and the number of inclusions. Further, it was concluded that control of the surface roughness and the number of inclusions was also effective in addition to the limitation of the Mn composition and the control of the texture. As a result of studying these points, the inventors found that the Mn content of the conventional 36% Ni invar material was 0.2 to 0.3 wt%, but Mn: 0.1 wt% or less, preferably 0.05 wt%.
It has been found that it is effective to commercialize low Mn materials.

The present invention is a material developed based on such knowledge. That is, the present invention relates to the following: Ni: 34 to 38 wt%, Mn: 0.1
In a material for an iron-nickel alloy shadow mask containing less than wt%, the cubic orientation (1
00) <001> and its twin orientation (221) <2
12>, wherein the X-ray intensity ratio Ir is in the range of 0.5 to 5: 1 and the cross-sectional cleanliness as defined by JIS G 0555 is 0.05% or less.
Ni-based shadow mask material.

Further, the present invention relates to a method of the present invention, wherein Ni: 34 to 38 wt%, Mn: 0.
In an iron-nickel alloy shadow mask material containing 1 wt% or less and S: 0.1 wt% or less, the cubic orientation (100) <001> and its twin orientation (221) <212> in the (111) pole figure. X-ray intensity ratio Ir of 0.5
Has a texture in the range of ５5: 1 and JIS G 055
5. A Fe-Ni-based shadow mask material characterized by having a cross-sectional cleanliness of 0.05% or less and a value of Mn (wt%) / S (wt%) of 2 or more as determined by the method described in No. 5.

In the present invention, the Vickers hardness specified by JIS Z 2244 is Hv 150 or more, more preferably Hv:
Provided is a material for an Fe-Ni-based shadow mask having 160 or more, more preferably Hv: 170 or more.

In the present invention, the above X-ray intensity ratio
(X-ray count number ratio) is 0.5 to 5: 1 as described above.
The lower limit of the preferred intensity ratio is 0.5 or more, more preferably 1 or more, more preferably 1.5 or more, and the upper limit of the preferred intensity ratio is 5 or less, further preferably 4.5 or less, more preferably 4.0 or less. .

The above materials are, for example, N: 34-38 wt%, M
n: An alloy containing 0.1 wt% or less, with the balance being substantially Fe, is used to anneal a cold-rolled material obtained by processing according to a conventional method. Before the final rolling, an annealing temperature: 900 to 1150 ° C. ,
It can be manufactured by performing an intermediate annealing of soaking time: 5 to 60 seconds, followed by a final annealing of an annealing temperature: 700 to 900 ° C. and soaking time: 60 to 600 seconds. In the above-described manufacturing method, it is preferable that each annealing condition is performed within a range illustrated in FIGS. 1A, 1B, 1C, and 1D.

In the present invention, the surface roughness is 0.2 μm ≦ Ra ≦ 0.9 μm, the surface roughness is 20 μm ≦ Sm ≦ 250 μm, and the surface roughness is −0.5 ≦ Rsk. It is effective. And, the surface roughness is 0.2 μm ≦ Ra ≦ 0.9 μm and −0.
5 ≤ Rsk, surface roughness 0.2 μm ≤ Ra ≤ 0.9 μm, -0.5 ≤
It is also effective to set Rsk and 20 μm ≦ Sm ≦ 250 μm. Further, according to the present invention, distribution on a surface polished to an arbitrary depth from the plate surface10
μm or more inclusions per unit area of 100 mm ²
Not more than 65, the number of inclusions of 10μm or more distributed on the cross section in the thickness direction is not more than 80 per 100 mm ² unit area, and also measured by the method according to JIS G 0551 It is preferable that the obtained crystal grain size number indicates a size of 7.0 or more.

[0015] The thickness of the shadow mask material is 0.
The range of 01-0.5 mm, preferably 0.1-0.5 mm, is common.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In general, streaks appear to be relatively wide in the width of individual streaks, unevenness caused by so-called segregation, and relatively streaks appearing in a thin silk pattern,
It can be classified into so-called streak unevenness (silk-like streaks) caused by crystal orientation. There is also a form in which both are mixed with each other. The present invention seeks to improve the latter of these non-uniformities, namely, the non-uniformity depending on the crystal orientation. Therefore, in the present invention,
By introducing the twin orientation of the (100) plane of the cubic orientation, the crystal orientation is controlled by disrupting the twin orientation. Hereinafter, the method of crystal grain orientation of the present invention will be described.

First, an alloy material having a predetermined component composition is hot-rolled according to a conventional method, subjected to recrystallization annealing, pickling, and the like, if necessary, and then subjected to, for example, intermediate cold rolling. Is subjected to intermediate annealing. This intermediate annealing is performed to control the development of the cubic orientation (100) <001>. This intermediate annealing is performed at a temperature of 900 to 1150 ° C. When the temperature is low (<900 ° C.), the cubic orientation in the final product is excessively developed, and the ratio of twin orientation (221) <212> becomes low, so that the line streak quality deteriorates. The reason why the streak quality deteriorates due to the decrease in the twin orientation ratio is that the alignment of the preferred orientation <001> in the rolling direction is slightly disturbed in each crystal grain unit due to the accumulation of the cubic orientation, and this becomes a stripe shape. It is considered visible. Conversely, when the temperature of the intermediate annealing is high (> 1150 ° C),
The cubic orientation is poorly developed, the etching rate is reduced, and the coherence of the individual etching holes is reduced during pattern etching of the shadow mask, resulting in the occurrence of overall unevenness called mottling.

The soaking time in the intermediate annealing is as follows:
The range of 5 to 60 seconds is preferable. If the time is shorter than 5 seconds, the recovery and recrystallization are not sufficiently performed, and the structure of a mixed particle state is maintained, thereby deteriorating the etching quality. On the other hand, if this time is longer than 60 seconds, the grains become coarse, the development of the cubic orientation is reduced, and a mixed grain structure is also formed, resulting in a decrease in etching properties.

Next, in the present invention, it is effective to regulate not only the conditions of the intermediate annealing described above but also the conditions of the final annealing. That is, the final annealing is performed in order to finely and uniformly arrange the crystal grains of the product and to prevent roughness of the hole wall after etching which causes mottling, and is performed at an annealing temperature of 700 to 900 ° C. , 60
It is effective to process with a soaking time of ~ 600 seconds. The reason is that if the annealing temperature is lower than 700 ° C. in the final annealing, recrystallization becomes insufficient, while if it is higher than 900 ° C., the recrystallization becomes coarse and the etching quality deteriorates.

The soaking time for the final annealing is as follows:
It is preferably in the range of 60 to 600 seconds depending on the degree of growth of individual crystal grains and development of crystal orientation. For example, if the soaking time is short (<60 seconds), the cubic orientation will be insufficiently developed, and the etching rate will decrease and mottling will occur. On the other hand, if the soaking time is long (> 60 seconds), the crystal grains become coarse, and the twin orientation is excessively developed with respect to the cubic orientation, resulting in a decrease in streak quality. These annealing conditions (intermediate and final) have an appropriate range, and a region surrounded by a, b, c, and d in FIG. 1 is preferable.

In order to obtain good press formability, the yield strength must be reduced. For this reason, in the present invention, it is necessary to reduce the Mn (0.1 wt% or less). At the same time, the amount of S is controlled to generate MnS, thereby reducing the proof stress. By the way, the control of the above-mentioned texture is effective for the press forming which appears at the time of annealing before press (11).
1) It has an important effect on the appearance of the crystal orientation, and especially when the pre-press annealing is performed with the X-ray intensity ratio Ir in the range of 0.5 to 0.5, the appearance intensity of the (111) orientation becomes highest. Therefore, according to such a method, it is possible to obtain a material for a shadow mask which has no mottling, has streak quality, and has good pressability.

Next, the reasons for limiting the component composition of the Fe—Ni-based shadow mask material according to the present invention will be described. C is
If it is contained in an amount of 0.1 wt% or more, not only does carbide precipitate and inhibits the etching property, but also adversely affects the shape freezing property after the shadow mask forming process. In addition, when the amount of C is large, the proof stress increases, the springback increases, and the adaptation to the mold during the molding process is deteriorated. Therefore, in the present invention,
C content is set to 0.1 wt% or less.

[0023] Si is one of the deoxidizing components, but if this amount is too large, the hardness of the material itself increases and at the same time C
In the same manner as described above, the moldability is adversely affected, and as the amount increases, the yield strength increases, and the springback increases. In addition, the influence on the stripe unevenness at the time of etching is produced.
Therefore, in the present invention, the amount of Si is preferably 0.5 wt% or less.

Mn is one of the deoxidizing components, and can be combined with S, which is harmful to hot workability, to form MnS, so that hot workability can be improved if added properly. However, if the addition amount is too large, the thermal expansion coefficient is increased and the Curie point is displaced to a higher temperature side. Therefore, in the present invention, the amount of Mn is set to 0.1 wt% or less. Preferably 0.075 wt% or less,
More preferably 0.07 wt% or less, even more preferably 0.06 wt%
%, Most preferably 0.05% by weight or less. In the present invention, by reducing the conventional addition amount of Mn from about 0.2 to 0.3 wt% to 0.1 wt% or less, there is a concern that the yield may decrease due to the deterioration of hot workability due to S. In this regard, the present invention further examines the relationship between S and Mn,
When considering the product yield, Mn (wt%) / S (wt
%) Is controlled to 2 or more, or Mn (wt%) / S
The value of (wt%) is preferably 2.5 or more, more preferably 3 or more, still more preferably 4 or more, and most preferably 5 or more.

If the content of S is 0.01 wt% or more, the hot workability is extremely deteriorated even if the relationship with Mn is adjusted.

Ni is the most important element in the present invention. If the Ni content is less than 34% by weight, the thermal expansion coefficient increases, and martensitic transformation may occur to cause uneven etching. On the other hand, when the amount of Ni is more than 38% by weight, there is a problem that a similar thermal expansion coefficient becomes large and color unevenness occurs when applied to a color CRT or the like. Therefore, in order to improve the good etching property and the color unevenness of the color cathode ray tube, the Ni content is 34 to 38 wt.
%.

Next, the present invention further controls the texture in addition to the above-described alloy design relating to the composition of the components in order to achieve the desired effects. The present inventors have confirmed by various experiments that it is necessary to satisfy the following conditions as a factor for obtaining good stripe unevenness in the form of the texture. The preferred texture for the shadow mask material according to the present invention is (111) pole figure in cubic orientation (100)
<001> and its twin orientation (221) <212>
To control the X-ray intensity ratio Ir. The range is the X-ray intensity ratio (X-ray count number ratio I) of the (111) pole figure.
r), from 0.5 to 5: 1, preferably from 1 to 4.5: 1, more preferably from 1 to 4.0: 1, even more preferably from 1.5 to 4.0: 1.
: 1 and the optimum ratio for producing a shadow mask material having excellent stripe quality was found to be 2 to 3.5: 1.

The method and conditions for measuring the X-ray intensity ratio Ir are as follows. First, the X-ray intensity ratio Ir is measured by covering one surface of a plate with a Teflon seal, and then coating the other surface with a commercially available chemical polishing liquid (manufactured by Mitsubishi Gas Chemical Co., Ltd.).
(CPE1000), and the thickness was reduced to 70 to 30% of the plate thickness to obtain a measurement surface. As the measurement surface, it is desirable to measure the vicinity of the center of the plate thickness. The (111) pole measurement by the Schulz reflection method was performed on the sample surface thus obtained after the chemical polishing under the measurement conditions shown in Table 1 below, and the (100) pole figure was obtained based on the pole figure obtained thereby.
The ratio between the X-ray intensity in the <001> direction and the X-ray intensity in the (221) <212> direction was determined. For each X-ray intensity, the maximum X-ray intensity (maximum X-ray count number) is obtained, the intensity is divided into 15 equal parts, and (100) <001> is obtained from the obtained pole figure.
And (221) the contour line intensity corresponding to the intensity corresponding to <212> was read, and the intensity was defined as the respective X-ray intensity. And thus obtained (10
The respective ratios of 0) <001> direction and (221) <212> direction were obtained and defined as X-ray intensity ratio Ir. Note that X
The linear intensity ratio Ir is defined as follows.
Ir = X-ray intensity of cubic orientation (001) <001> / twin orientation (221) <
X-ray intensity of 212>

[0029]

[Table 1]

FIG. 2 summarizes the relationship between the X-ray intensity ratio and the etching. In this figure, the horizontal axis represents the logarithm of the X-ray intensity ratio Ir, and the vertical axis represents the etching factor (the value obtained by dividing the etching amount in the depth direction when pattern etching was performed by the etching amount in the width direction (side etch). )
This shows the mottling quality of the line. As shown in the figure, it is recognized that the etching factor (etching speed in the thickness direction) increases as the X-ray intensity ratio Ir increases (the ratio of twins decreases). on the other hand,
The streak quality deteriorates when the X-ray intensity ratio Ir is too large or too small. As can be seen from the results shown, the appropriate range of the X-ray intensity ratio Ir is in the range of 0.5 to 5. In addition, with respect to motoling, it is advantageous that the etching rate is high, but as can be seen from the figure, it is almost
Ir: If it exceeds 1.0, there is no significant change, and it is considered that there is no difference.

Table 3 shows a study of the Fe—Ni-based materials shown in Table 2 manufactured under the conditions shown in Table 3. For example, in No. 11, the cubic orientation of (100) <001> is more developed, and the X-ray intensity ratio Ir with the (221) <212> twin orientation is 13.91. Regarding the etching property of this sample (comparative material 11), as shown in Table 3, although the mottling was good due to the high etching rate, the stripes were clearly recognized, and as an actual shadow mask product, Is not suitable.

[0032]

[Table 2]

[0033]

[Table 3]

Materials Nos. 1, 3 and 4 of the present invention in Table 3 are materials conforming to the present invention. Comparative material No. 6 is (1
00) <001> The cubic orientation is very weak, and the normalized intensity ratio is 0.36: 1. This comparative material No.
As for the etching property of No. 6, the quality of the mottling is poor, which is also unsuitable as a shadow mask product.

The present invention is directed to a material which defines an appropriate range of the azimuth component by such a pole figure, thereby preventing the occurrence of streaking unevenness at the time of etching and the occurrence of overall unevenness called motoling which occur in a material for a shadow mask. is there.

The material according to the present invention also has an X-ray intensity ratio I
r in addition to the limited texture shown by r
The cleanliness of the cross section according to the definition of 5 is set to 0.05% or less, preferably 0.03% or less, more preferably 0.02% or less, and further preferably 0.017% or less. The reason for this is that if the cross-sectional cleanliness d exceeds the above value, the etching accuracy is reduced and the product defect rate is reduced.

The measured value of the section cleanliness d is JIS
Perform according to G 0555. Specifically, the product was cut to a length of 30 mm in the rolling direction, and after polishing the cross section, a grid having 20 grid lines each in the vertical and horizontal directions was mounted on a microscope,
While moving the field of view in a zigzag as shown in FIG.
The observation was performed by observing 60 visual fields at a magnification of 00 times. Therefore,
The measurement surface is a cross section parallel to the rolling direction, and the measurement area is a sheet thickness × 30 mm. When the number of lattice points is P, the number of visual fields is f, and the number of total lattice point centers in f visual fields is n, the cross-sectional cleanliness d is expressed by the following formula: d (%) = (n / P × f) × 100.

In the present invention, the Vickers hardness specified by JIS Z 2244 is Hv: 150 or more, more preferably Hv: 16
Provided is a Fe—Ni-based shadow mask material characterized by having an Hv of 170 or more, more preferably Hv: 170 or more. The reason is that if an Fe—Ni alloy having such a hardness is used, it is easily softened for press forming when it is etched and annealed thereafter. In order to control the hardness, the rolling reduction in dull rolling after final annealing is reduced by several percent.
It can be controlled by controlling at about 20%.

The material according to the present invention also comprises Ra, Rsk, Sm
It is preferable to appropriately control the roughness of the material surface represented by First, in the product surface roughness, the center line average roughness Ra
Is a parameter indicating the average size of the roughness. If this value is too large, scattering at the time of exposure is increased, and a difference occurs in the drilling start time at the time of etching, so that the shape of the hole is deteriorated. On the other hand, if it is too small, exhaust is not sufficiently performed at the time of evacuation, and poor adhesion between the pattern and the material is likely to occur. Therefore, in the present invention, 0.2 ≦ Ra ≦ 0.9. A preferred lower limit of the center line average roughness Ra is 0.25 μm or more,
More preferably 0.3 μm or more, still more preferably 0.35 μm
m or more is preferable. On the other hand, the upper limit is preferably 0.85 μm or less, more preferably 0.8 μm or less, and even more preferably 0.7 μm or less.

Next, Rsk, which indicates the relativity of the surface roughness, is a parameter that simply indicates whether the pattern is convex or concave, and the symmetry with respect to the center line of the amplitude distribution curve (ADF) distribution is calculated according to the following equation. Is a numerical value. Rsk = 1 / σ ³ ∫Z ³ P (z) dz Here, σ indicates the root mean square value, and ∫Z ³ P (z) dz indicates the third moment of the amplitude distribution curve. When the value of Rsk is negative and large, scattering at the time of exposure is increased, and the shape of the hole is deteriorated. On the other hand, if it is too large, the evacuation is not sufficiently performed, and poor adhesion between the pattern and the material is likely to occur. Therefore, in the present invention, -0.5≤Rsk. A preferred lower limit is 0 or more, and a more preferred lower limit is 0.1 or more.
On the other hand, the upper limit is preferably 1.3 or less, more preferably 1.1 or less, and 1.0 or less as an optimal example.

Next, the average peak gap represented by Sm indicates the size of the pitch of the peaks and valleys of the roughness, and such roughness is caused by partial evacuation that occurs when the unevenness is too large. It can be said that this clearly indicates a defect in the hole shape due to the strong scattering at the time of exposure which occurs when the defect is too small. In the present invention, this Sm is set to 20 μm ≦ Sm ≦ 250 μm. This Sm
Is preferably at least 40 μm, more preferably at least 50 μm, even more preferably at least 80 μm. On the other hand, a preferred upper limit is 200 μm or less, more preferably 160 μm or less,
More preferably, it is 150 μm or less, and the optimal example is 130 μm or less.

The surface roughness as described above can be easily realized by using a dull roll when the material for a shadow mask according to the present invention is cold-rolled to a final size. The dull roll is a roll having a predetermined surface roughness. By using this roll to roll a shadow mask material made of the present alloy, it is possible to stamp the inverted pattern at an appropriate transfer rate. In order to obtain such a dull roll, it can be easily obtained by processing by electric discharge machining, laser machining, shot blasting or the like. For example, it can be performed by using a steel grid of # 120 as a roll processing condition by the shot blast method.

In the present invention, it is effective to control the number of inclusions in addition to the above characteristics. That is, it is preferable that polishing is performed to an arbitrary depth from the plate surface, and the number of inclusions having a size of 10 μm or more distributed on the surface is controlled to 65 or less per unit area of 100 mm ² . In this case, the number is preferably 50 or less, more preferably 30 or less, still more preferably 25 or less, and most preferably 20 or less. The reason for this limitation is that, in general, a shadow mask requires a fine etching technique, so that it is better that the inclusions in the material be as small as possible. Although the number of inclusions and the cross-sectional cleanliness are similar concepts, the cross-sectional cleanliness d alone merely defines the area of the foreign matter. It is also effective to limit the size of. The method for measuring the number of inclusions was as follows: the plate surface was polished, and finally finished by buffing, and the surface parallel to the plate surface was observed with a microscope to measure the number. For the measurement, a 10 mm × 10 mm surface was observed. FIGS. 3 and 4 show photographs of large inclusions that cause defects.

In the present invention, in addition to the control of the number of inclusions on the surface of the plate, 10 μm
It is effective to control the number of the above inclusions to 80 or less per unit area of 100 mm ² . This number is preferably
70 or less, more preferably 50 or less, still more preferably
The optimal example is 40 or less, 30 or less, especially 20 or less. This is because the defect rate cannot be reduced to 0 only by controlling the cross-sectional cleanliness d described above, and the defect rate is further reduced by limiting the size of the inclusions. Because it can be. The method of measuring the number of inclusions in the cross section in the thickness direction is as follows.
A section parallel to the rolling direction was polished, finished by buffing, and observed with a microscope. The measurement was performed by measuring about three cross sections having a thickness of 25 mm and a length of 100 mm ² . FIG. 9 shows a photograph of a large inclusion causing a defect. In the present invention, the above-described method of controlling the degree of cleanliness and the number of inclusions can be achieved by separating and floating the inclusions in a ladle during the refining process.

In the present invention, the grain size of the alloy is further determined by the grain size number measured by the method according to JIS G 0551.
It is preferable to use a particle size that indicates a size of 7.0 or more (more fine control). Preferably 8.0 or more, more preferably
It is 8.5 or more, more preferably 9.5 or more. The reason for limiting in this way is that it is necessary to make the crystal having a crystal grain size number of 7.0 or more.First, if the crystal grain is large, the diameter of the hole at the time of etching differs in the etching rate of each crystal orientation, Variation and unevenness of transmitted light due to unevenness of etching holes occur, and eventually, a phenomenon called motoling occurs, and hole defects occur, thereby lowering the yield. Also, the crystal grains become too large during the press working, which causes a press failure. The method of measuring the crystal grain size is such that the plate cross section in the direction perpendicular to the rolling direction is a microscopic surface, etched with aqua regia after buffing, and the austenite structure standard crystal grain size described in JIS G 0551 at an observation magnification of 200 times. The grain size number is determined by comparison with the figure. Since the standard grain size diagram is based on an observation magnification of 100 times, the grain size number in the standard diagram was corrected by +2.0. (Measure the grain size number in increments of 0.5)

[0046]

Example 1 An ingot of an alloy having a composition shown in Table 2 above and conforming to the present invention was melted by a vacuum degassing process, and then hot-rolled to form a hot-rolled sheet of 5 mm. This was repeatedly manufactured by repeatedly performing cold rolling and annealing under the conditions shown in Table 3 to obtain 0.13 t
After being adjusted to the product thickness of, the product was evaluated as an actual shadow mask product through an actual photo-etching process. Etching was performed using a 0.26 mm pitch mask pattern, 46 Baume ferric chloride solution, a liquid temperature of 50 ° C, and a spray pressure.
The test was performed at 2.5 kgf / cm ² . Sample Nos. 1 to 5 in Table 2 are examples manufactured according to the present invention, and Sample Nos. 6 to 11 are examples of comparative materials. When the properties of the obtained shadow mask products after etching were evaluated, all of the materials of the present invention exhibited good mold conformability to a mold in press moldability and good tensile rigidity, and also exhibited blackening properties. Also, it was confirmed that a blackened film having good adhesiveness and sufficient radiation characteristics was formed, and it was found that the film exhibited excellent characteristics as a shadow mask product.

Embodiment 2 In this embodiment, if the X-ray intensity ratio and the cross-sectional cleanliness d are within the proper ranges, the shadow mask material is compared with the conventional shadow mask material.
Although it is a shadow mask material that is sufficiently satisfactory in terms of quality and product yield, a combination with various factors was examined in order to further improve the yield and the like. Table 4 shows the results. Table 4 shows section cleanliness and surface roughness (Ra, Rsk, S
m), the number of inclusions and grain size number of 10μm or more of the plane and cross section and the presence or absence of seizure during annealing before press,
It shows the relationship between the hole defect rates. Surface roughness meter
Tokyo Seimitsu Surfcom 1500A was used. As a result, the following became clear. When the cross-sectional cleanliness exceeds 0.05%, the percentage of defective holes increases slightly (No. 44). When the number of inclusions of 10 μm or more observed in a plane and a cross section exceeded 65 per unit area and 80, respectively, it was confirmed that the occurrence of hole defects slightly increased (No. 5).
0, 51). When the crystal grain size number becomes 7.0 or less, the hole defect rate slightly increases.However, since the individual crystal grains are large, the hole shape depends on the crystal orientation, and it is relatively difficult to form uniform holes. (No.52). As described above, proper surface roughness has the role of improving the adhesion of the resist in the resist coating and etching processes before etching, improving the vacuum evacuation, preventing halation due to exposure, and preventing shadowing during annealing before pressing. Prevents close contact between masks, and thus prevents unevenness of the blackened (oxidized) film due to close contact. In order to support these points, it was confirmed that depending on the combination of Ra, Rsk, and Sm, unevenness of blackening due to the hole defect rate due to etching and seizure (adhesion between the plates during annealing before press) was caused.
(No. 45, 46, 47, 48, 49).

[0048]

[Table 4]

Example 3 Table 5 shows the relationship between hot rolling and press formability. Press formability was evaluated based on mold conformability after etching annealing, and was performed by a warm press. Inventive Examples 1 to 4 all have a good yield by hot rolling, and also have good pressability after etching annealing under relatively low temperature pressing conditions of 180 ° C. In Reference Example 5, the value of Mn / S was 1
Therefore, although the yield in hot rolling is slightly lowered, the press formability is extremely good and there is no practical problem. On the other hand, Comparative Examples 6 to 8 are out of the range of the present invention, and those having a high Mn or those having the X-ray aggregability ratio Ir out of the range are inferior in press formability. Also, materials having Hv 150 or more before etching tend to have low Hv after subsequent etching and annealing (750 ° C.), and tend to have improved workability.

[0050]

[Table 5]

[0051]

As described above, according to the present invention, a Fe-Ni-based alloy having excellent etching characteristics, especially a Fe-Ni alloy having a low thermal expansion which does not cause uneven stripes or mottling during etching.
A material for a Ni-based shadow mask can be provided. Therefore, it is possible to reliably provide a high-yield material for a color CRT or a display having a beautiful image.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing the relationship between the appropriate ranges of intermediate annealing conditions and final annealing conditions according to the present invention.

FIG. 2 shows Ir, an etching factor, and streaks,
It is explanatory drawing which shows the relationship with the quality of moto ring.

FIG. 3 is a micrograph showing an example of large inclusions on the surface of an alloy plate.

FIG. 4 is a micrograph showing an example of a large inclusion in a cross section of an alloy plate.

FIG. 5 is a view showing a method for measuring the cross-sectional property of an alloy plate.

────────────────────────────────────────────────── (5) References JP-A-2001-59140 (JP, A) JP-A-8-333638 (JP, A) JP-A-6-158229 (JP, A) JP-A-9-262603 (JP, A) JP-A-7-34200 (JP, A) JP-A-9-310158 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C22C 38/00-38 / 60

Claims (9)

(57) [Claims] 1. A material for an iron-nickel alloy shadow mask containing 34 to 38% by weight of Ni and 0.1% by weight or less of Mn,
(111) Cube orientation in pole figure (100) <00
X of (1) and its twin orientation (221) <212>
A material for an Fe-Ni-based shadow mask, having a texture having a linear intensity ratio Ir in the range of 0.5 to 5: 1 and having a cross-sectional cleanliness of 0.05% or less as defined by JIS G 0555. . 2. Ni: 34 to 38 wt%, Mn: 0.1 wt% or less,
S: In an iron nickel alloy shadow mask material containing 0.01 wt% or less, the cubic orientation (100) <001> in the (111) pole figure and its twin orientation (22)
1) It has an X-ray intensity ratio Ir with <212> in the range of 0.5 to 5: 1, has a cross-sectional cleanliness of 0.05% or less as defined by JIS G 0555, and has a Mn (wt% )
/ S (wt%) is 2 or more.
Ni-based shadow mask material. 3. The Vickers hardness specified by JIS Z 2244 is Hv 150 or more.
The material for an Fe-Ni-based shadow mask described in the above. 4. The material for a Fe—Ni-based shadow mask according to claim 1, wherein the surface roughness is 0.2 μm ≦ Ra ≦ 0.9 μm. 5. The material for a Fe—Ni-based shadow mask according to claim 1, wherein the surface has a roughness of 20 μm ≦ Sm ≦ 250 μm. 6. The Fe-Ni-based shadow mask material according to claim 1, wherein the surface roughness satisfies -0.5 ≦ Rsk. 7. The method according to claim 1, wherein the number of inclusions having a size of 10 μm or more distributed on a surface polished to an arbitrary depth from the plate surface is 65 or less per unit area of 100 mm ² . The material for an Fe-Ni-based shadow mask according to any one of the preceding claims. 8. The method according to claim 1, wherein the number of inclusions having a size of 10 μm or more distributed in a cross section in the thickness direction is 80 or less per unit area of 100 mm ^2. Fe-Ni-based shadow mask material. 9. The Fe-particle according to claim 1, wherein a crystal grain size number measured by a method according to JIS G 0551 indicates a size of 7.0 or more.
Ni-based shadow mask material.