WO2003069006A1

WO2003069006A1 - Mask material for color picture tube, its production method, mask for color picture tube, and color picture tube

Info

Publication number: WO2003069006A1
Application number: PCT/JP2003/001374
Authority: WO
Inventors: Kengo Iwanaga; Yasuyuki Ikeda; Yasuo Tahara; Yoshikazu Maruhashi; Hironao Okayama
Original assignee: Toyo Kohan Co., Ltd.
Priority date: 2002-02-12
Filing date: 2003-02-10
Publication date: 2003-08-21
Also published as: JP3600818B2; AU2003207203A1; JP2003231949A; TW200302871A

Abstract

A mask material for a color picture tube excellent in tensile strength, creep extension, and magnetic characteristics. A low carbon steel to which Ni, Al, and Ti, or Ni, Al, Ti, and B are added is subjected to hot rolling, pickling, primary cold rolling, intermediate annealing, secondary cold rolling, and age precipitation so as to precipitate fine grains of intermetallic compounds such as NiAl(Ti) and Ni3Al(Ti) by aging in the steel. A method for producing the material, a mask for a color picture tube, and a color picture tube incorporating the mask.

Description

Material for color picture tube mask, method for producing the same, mask for color picture tube, and color

Technical field

The present invention relates to a color picture tube for a color television or a color display device of a computer.

MASK MATERIAL, PROCESS FOR PRODUCING THE SAME, MASK FOR COLOR PICTURE TUBE, AND COLOR

It relates to a picture tube.

Background art

In a color picture tube such as a color television or a color display device of a computer, a mask such as a shadow mask or an aperture grill is used so that a predetermined phosphor is irradiated with an electron beam. Traditionally, these masks have been used by being attached to curved color picture tubes.Burned color picture tubes are apt to fatigue eyes due to irregular reflection of external light such as illumination, and distorted images at corners. Therefore, flattening of a color picture tube is desired.

In a color picture tube, in order to obtain a clear image, it is required that the electron beam can be accurately irradiated on the phosphor surface without shifting the position of the slit formed in the mask. In the case of a mask used for a conventional curved color picture tube, the mask has a curvature, so that the center of the mask does not sag and dimensional stability can be easily obtained. However, when the color picture tube is flattened, the mask tends to sag at the center portion, resulting in a problem that the image is distorted. In order to solve this problem, it is necessary to apply tension from the center to the outer periphery of the mask and attach it to the frame of the mask, so that the mask does not sag at the center of the mask. . Therefore, the stretch-type mask material used for the flat-type color picture tube is required to have high tensile strength because it can be attached to the frame by applying high tension to the frame. Furthermore, after being welded to the frame, heat treatment is performed to blacken the mask surface, but even after darkening, it is necessary to maintain a state in which tension is applied so that slack does not occur at the center of the mask. There is. Therefore, it is necessary that the creep elongation be small in order to avoid recovery of the black ligne by heat treatment. Furthermore, the color picture tube is composed of an electron gun and a phosphor that converts the electron beam into an image, and the inside of the picture tube must be magnetically shielded so that the electron beam is not deflected by geomagnetism. There is. The mask must also have a function as a magnetic shielding material, and the material for the mask has a large residual magnetic flux density Br as a magnetic property and a small coercive force Hc, that is, a residual magnetic flux density Br. It is also necessary that the ratio to the magnetic force He (Br / Hc) be large.

Conventionally, low carbon steel solid solution strengthened with C or N has been attempted to improve the tensile strength.However, when the amount of C or N in the steel increases, carbides and nitrides increase, The movement of the domain wall is hindered, and the magnetic properties deteriorate. There is also a method of precipitating carbides and the like in steel in order to reduce creep elongation to a small extent.However, most of the precipitates have a large particle size of the order of um, hinder domain wall movement, Deteriorates. On the other hand, by using the Fe-Ni-invar alloy, which has a small dimensional change due to heat, for the mask material, the tension when the mask is mounted on the frame with the tension applied is reduced, and the creep strength is also reduced. Attempts have been made, but invar alloys are expensive and costly.

An object of the present invention is to provide a mask material for a color picture tube having excellent tensile strength, creep elongation, and magnetic properties, a method for manufacturing the same, a mask for a color picture tube, and a color picture tube incorporating the same. Disclosure of the invention In the mask material for a color picture tube of the present invention, Ni is 2 to 5% by weight, A1 and Ti are both 0.5 to 2% by weight in total, and the balance is Fe and unavoidable impurities. Materials for color picture tube masks, or

N i is 2-5 wt ^_0/0, A 1 and T i is from 0.5 to 2 weight in total of both. / ₀ , B exceeds 0% by weight and 0.05% by weight. The remainder is a material for a mask for a color picture tube, the remainder being Fe and unavoidable impurities.

The material for the color picture tube mask has a tensile strength of 50 ONZmm ² or more;

300 intensive stress of N / mm ^2, 460 to ° 1 hour held stretched when the C was set to be 3% or less 0.1,

It is desirable that the ratio of the residual magnetic flux density Br to the coercive force He, that is, Br (kG) / He (Oe) be 2 or more.

In the method of manufacturing a mask material for a color picture tube according to the present invention, Ni is 2 to 5% by weight, and A1 and Ti are 0.5 to 2% by weight in total. /. A steel slab consisting of Fe and unavoidable impurities is hot-rolled and pickled, first cold-rolled, then intermediately annealed at 700 to 900 ° C, and secondarily cold-rolled. A method for producing a material for a mask for a color picture tube, characterized by aging at 400 to 700 ° C, or

Ni force S 2 to 5% by weight, A1 and Ti in total of 0.5 to 2% by weight, B over 0% by weight and 0.05% by weight or less, remainder Fe and inevitable impurities After hot rolling, pickling, primary cold rolling, intermediate annealing at 700 to 900 ° C, and secondary cold rolling, aging at 400 to 700 ° C A method for producing a material for a color picture tube mask.

Further, the mask for a power picture tube of the present invention is characterized by using any of the above-mentioned materials for a mask for a power picture tube, and can be used as a mask for a normal curved color picture tube, and in particular, can be expanded. It can also be suitably used as a mask for a mold color picture tube. The color picture tube of the present invention is characterized by using any one of the color picture tube masks described above. BEST MODE FOR CARRYING OUT THE INVENTION

In the present invention, low carbon steel to which Ni and A 1 and T i, or B is further added, is hot-rolled, pickled, cold-rolled first, then subjected to intermediate annealing, and further subjected to secondary cold-pressing. Excellent tensile strength by performing aging precipitation treatment after elongating to precipitate fine intermetallic compounds such as fine NiA1 (Ti) and NisA1 (Ti) in steel. Thus, it was possible to obtain a small creep elongation and a suitable Br / He. Hereinafter, the present invention will be described in detail.

As the low-carbon steel applied to the mask material for a color picture tube of the present invention, the carbon and nitrides in the steel are reduced by decarburization and denitrification using a vacuum degassing method, and hot rolling is performed. Are preferred. Next, the types of elements contained in the low carbon steel applied to the mask material for a color picture tube of the present invention and the reasons for limiting the contents thereof will be described.

C forms a solid solution in steel and increases the hardness of the material, improves tensile strength, and suppresses creep elongation to a small extent.Therefore, a force that must be contained to some extent The amount of C in the steel sheet after cold rolling is large. If too much, carbides increase, deteriorating the etching characteristics required for forming holes and slits in the mask, hindering the movement of the domain wall, and suppressing the growth of crystal grains, deteriorating the magnetic characteristics. Therefore, the upper limit of the content is preferably set to 0.06% by weight. The lower limit is preferably as low as possible as much as practically possible by vacuum degassing.

Mn is an element necessary for bonding with S in steel and fixing it as Mn S to prevent red hot brittleness in hot rolling.However, in order to improve magnetic properties, the lower the content, the lower the content. Preferably, the upper limit of the content is 0.5% by weight.

Since Si deteriorates the adhesion of the blackened film formed by the blackening treatment, it is 0.3% by weight. Is the upper limit of the content. The content of S is preferably small from the viewpoint of crystal grain growth, and the upper limit is 0.05% by weight. Similarly, the content of N is preferably as small as possible, and the upper limit is 0.05% by weight.

Ni is an element necessary for age-precipitating intermetallic compounds such as Ni A 1 (T i) and Ni ₃ A 1 (T i) .As the content increases with A 1 and T i, The amount of precipitation of intermetallic compounds during aging treatment increases, the tensile strength increases, and the creep elongation decreases. Intermetallic compounds such as N i A 1 (T i) and N i ₃ A 1 (T i) precipitate with a fine particle size on the order of nm, and unlike precipitates on the order of μηι, There is almost no hindrance to movement, and the degree of deterioration in magnetic properties is extremely small. Therefore, the tensile strength can be improved without deteriorating the magnetic properties, and the creep elongation can be suppressed to a small value. If Ni is less than 2% by weight, sufficient tensile strength cannot be obtained, and it is difficult to suppress creep elongation. Therefore, the lower limit of the content is set to 2% by weight. On the other hand, when the Ni content in the steel increases, the M s point (Martensite starting point) decreases, and the steel becomes a hard martensitic structure. Even if intermediate annealing is performed after primary cold rolling, secondary cold rolling is performed. Since it becomes extremely difficult to perform rolling, the upper limit of the content is set to 5% by weight.

A 1 and T i is an element necessary to with N i N i A 1 (T i), an intermetallic compound such as N i ₃ A 1 (T i) is aging precipitation, the content of N i Also included in steel. By containing only A 1 N i A 1 and N i ₃ A or by aging precipitation of intermetallic compounds such as 1, by containing only T i N i T i and N i ₃ T i intermetallic compounds such as When aging precipitates, the effect of increasing the tensile strength and suppressing the creep elongation can be obtained, but Ni A 1 (T i), Ni ₃ A When a complex intermetallic compound such as 1 (T i) is formed, the tensile strength is increased and the creep elongation is suppressed to a small extent, compared with the case where only A 1 is contained or the case where only T i is contained. Greater effects can be obtained. Therefore, A 1 and T i determine the lower and upper limits of the content by the sum of both. If the total content of both A1 and Ti is less than 0.5% by weight, the amount of intermetallic compound deposited will be insufficient, and the tensile strength will be sufficiently improved, and the creep Cannot be suppressed sufficiently small. On the other hand, if the content exceeds 2% by weight, the magnetic properties deteriorate, which is not preferable.

B is an element that segregates preferentially at the grain boundaries, and is selectively contained in steel in addition to the above elements. If B is further added to steel containing the above elements in the above ranges, grain boundary precipitation of intermetallic compounds such as NiA1 (Ti) and Ni3A1 (Ti) may occur. It is suppressed, and the dispersion of the intermetallic compound in the steel becomes more uniform. However, if the content exceeds 0.05% by weight, the etching characteristics deteriorate.

Next, a method for producing a thin steel sheet as a material for a mask for a color picture tube according to the present invention will be described.

After hot-rolling low-carbon steel with the above chemical composition produced by vacuum melting or vacuum degassing, pickling is performed to remove the oxide film on the steel sheet surface generated in the hot rolling process. . Subsequently, primary cold rolling is performed to obtain a sheet thickness of 0.2 to 0.5 mm. Next, softening treatment is performed by intermediate annealing at 700 to 900 ° C. If the annealing temperature is lower than 700 ° C., it does not sufficiently soften, and the subsequent secondary cold rolling becomes extremely difficult. On the other hand, if the annealing is performed at a temperature exceeding 900 ° C., the required tensile strength cannot be obtained even after the secondary cold rolling and then the aging precipitation treatment. Either box annealing or discontinuous annealing can be applied as the annealing method.

Next, the sheet is subjected to secondary cold rolling to a predetermined thickness of 0.05 to 0.2 mm as a mask material. After that, the aging treatment is performed at 400 to 700 ° C. for several tens of seconds to several hours. Aging precipitation temperature 4 0 0 ° N i A 1 is less than C (T i), N i 3 A 1 (T i) not sufficiently precipitated intermetallic compounds such as the required tensile strength is obtained Absent. On the other hand, if the aging precipitation treatment is performed at a temperature exceeding 700 ° C, overaging occurs, and the intermetallic compound re-dissolves in the steel, and the tensile strength decreases. For the aging precipitation treatment, either a box type annealing furnace or a continuous annealing furnace may be used depending on the heating temperature and the heating time.

The material for a mask for a color picture tube of the present invention obtained as described above is fixed to a frame after being press-formed as it is in accordance with the shape of a normal curved power picture tube. It can be used as a mask, or it can be used as an extended mask used for a color picture tube having a flat screen as described later. In this case, the mask is fixed to the frame under tension. If color picture pipe mask material of the present invention is used as a stretched mask, but actually is in a state of tension loaded more than 40 ONZmm ^2, the pilot in the 30 ON / mm ² applied stress If the elongation after holding at 460 ° C for 1 hour is 0.3% or less, the mask material will not loosen even when used for a picture tube.

For these reasons, it is necessary that the mask material for a color picture tube of the present invention has a tensile strength of 50 ONZmm ^{2 or more} . Tensile When strength is Ru der less than 50 ON / mm ^2, intensive stress of 30 ON / mm ² as mentioned above, beyond 3% 0.1 elongation at the time of 1 hour at 460 ° C, kinescope The mask material will become loose when used for The upper limit of the tensile strength is not particularly specified, but is preferably 90 ON / mm ² or less.

Further, the mask material for a color picture tube according to the present invention must also have a function as a magnetic shielding material, and the precipitates in the steel do not impede the movement of the magnetic domain wall and degrade the magnetic properties. It is necessary to produce fine precipitates of the order. The intermetallic compounds such as NiA 1 (T i) and Ni ₃ A 1 (T i) which precipitate by aging in the color cathode ray tube mask material of the present invention are fine precipitates, but remain as magnetic properties. It is preferable that the magnetic flux density Br is large and the coercive force He is small, that is, Br (kG) / He (Oe) indicating the ratio of the residual magnetic flux density Br to the coercive force He is 2 or more. If B r (kG) / He (O e) is less than 2, the electron beam is deflected by the geomagnetism, and a clear color image without distortion cannot be obtained.

Next, a method for manufacturing a mask for a color picture tube according to the present invention will be described. A water-soluble casein resist is applied to both sides of the mask material for a color picture tube obtained as described above, and after drying, the resist on both sides of the mask material is applied to a pair of front and back patterns using a glass dry plate. And pattern the resist. Next, exposure and hardening Then, a baking treatment is performed, and thereafter, etching is performed on both sides of the patterned resist by spraying a ferric chloride solution having a liquid temperature of 60 ° C. and a specific gravity of 48 ° Be from a spray as an etchant. After etching, it is washed with water, the resist is stripped with an alkaline solution, washed and dried to make a mask for a color picture tube.

Next, a state in which the color picture tube mask of the present invention is attached to a frame will be described. As described above, the color picture tube mask of the present invention can be used as it is, after being press-formed according to the shape of a normal curved color picture tube, and then fixed to a frame, as described below. It can also be used as a stretch mask for flat color picture tubes. In this case, the mask is fixed to the frame under tension. There are various fixing methods, but the welding method is most often used. At the time of fixing, the center portions of the upper and lower frames of the frame are forcibly slightly bent inward, and then the mask is fixed to the frame by welding. Then, when the forcibly applied force is removed from the upper and lower frames that are inwardly radiused and the original shape is restored, the mask is in a state where vertical tension is applied to the mask. Also, in the case of a shadow mask in which a substantially circular dot hole is formed in the mask material, when the mask is fixed to the above-described frame, a tension smaller than the tension applied vertically to the mask is applied. It is also preferable to apply a load in the left-right direction of the mask. By applying tension not only in the vertical direction but also in the horizontal direction of the mask, wrinkles that may occur in the horizontal direction can be prevented. However, it is not preferable to apply excessive tension in the left and right directions of the mask, since the formed dot holes are deformed. Example

Hereinafter, the present invention will be described in more detail with reference to Examples.

(Example)

A slab obtained by vacuum degassing a low carbon steel having a dangling composition shown in Table 1 was hot rolled to obtain a hot rolled sheet having a sheet thickness of 2.5 mm. After washing these hot rolled sheets with sulfuric acid, Cold-rolled to obtain a cold-rolled sheet having a sheet thickness of 0.3 mm. Table 1 Chemical composition of low carbon steel

Next, these cold-rolled sheets were subjected to intermediate annealing under the conditions shown in Table 2, and then subjected to secondary cold rolling to form cold-rolled sheets having a thickness of 0.1 mm. A time exposure treatment was performed under the conditions shown below to obtain a test material for a mask material for a color picture tube. Table 2 Intermediate annealing conditions and aging precipitation conditions for cold rolled sheets

Note) #: Not implemented because secondary cold rolling is not possible The tensile strength of each test material for mask material obtained in this manner was measured using Tensilon. 5◦ ON / mm ² or more was set as a good range. Using a simple Epstein-type magnetometer, a residual magnetic flux density B r (kG) and coercive force He (O e) were measured by applying a magnetic field of 1 OO e, and B r (kG) / He ( O e) was determined, and two or more were determined to be good. Furthermore, the creep test machine (Tokai Seisakusho) loaded with load stress 300N / mm ² was used to measure the creep elongation when the one hour hold at 460 ° C in the atmosphere, and good 0.3% or less did. Table 3 shows the measurement results of the properties of the test materials. In Table 3, C4 and J could not be subjected to secondary cold rolling and could not be evaluated.

Table 3 Properties of test materials

Characteristics l> i sword mouth

Tensile strength creepage Br / Hc

(N / mm ² ) (kG / Oe)

A 6 1 1 0.26 3.2 The present invention

B 633 0.27 3.4 The present invention

C 1 607 0.19 3.7 The present invention

C 2 563 0.24 3.4 The present invention

C 3 513 0.28 3.2 The present invention

C 5 438 0.64 5.6 Comparative example

D 1 816 0.13 2.1 The present invention

D 2 798 0.18 2.7 The present invention

D 3 503 0.30 3.1 The present invention

D 4 487 0.51 5.3 Comparative example

D 5 421 0.63 4.7 Comparative example

E 701 0.21 2.3 The present invention

F 772 0.07 2.5 The present invention

G 767 0.06 2.7 The present invention

H 61 1 0.23 3.5 The present invention

I 478 0.56 5.1 Comparative example

K 41 1 0.81 6.4 Comparative example

L 7 13 0.19 1.7 Comparative example As shown in Table 3, the mask material for a color picture tube of the present invention has a tensile strength, BrZHc, and creep elongation in a preferable range, and the mask does not loosen as a mask for a flat stretchable color picture tube. It can be understood that the color picture tube of the present invention in which the mask is incorporated is capable of obtaining a clear color image without distortion because the electron beam is not deflected by geomagnetism. Industrial applicability

The mask material for a color picture tube according to the present invention comprises fine particles such as fine Ni A1 (T i) and fine Ni ₃ A 1 (T i) in low carbon steel to which Ni and A 1 and Ti are added. Aging precipitation of a suitable intermetallic compound and further selective addition of B to suppress intergranular precipitation of the intermetallic compound so that the intermetallic compound is uniformly and finely precipitated in the crystal grains. Thus, excellent tensile strength, excellent suppressed creep elongation, and suitable Br / Hc can be obtained. For this reason, the flat expansion-type color picture tube mask of the present invention in which this material is fixed to the frame under a tension while being applied with tension does not loosen during use even when incorporated into the color picture tube. In addition, the color picture tube of the present invention in which the mask for the color picture tube is inserted into the mask does not deflect the electron beam due to terrestrial magnetism, so that a clear color image without distortion can be obtained.

Claims

The scope of the claims

1. Ni-force S 2 to 5% by weight, A1 and Ti are 0.5 to 2% by weight in total, and the balance is Fe and inevitable impurities.

2. Ni is 2 to 5% by weight, A1 and Ti are 0.5 to 2% by weight in total, B is more than 0% by weight and 0.05% by weight or less, the balance is Fe and inevitable Material for masks for picture tubes made of impurities.

3. The mask material for a color picture tube according to claim 1, which has a tensile strength of 50 ONZmm ² or more.

4. intensive stress of 300 NZmm ^2, elongation when held for 1 hour at 460 ° C was set to be zero. 3% or less, the mask for color picture tube according to any one of claims 1 to 3 material.

5. The mask material for a color picture tube according to any one of claims 1 to 4, wherein the ratio of the residual magnetic flux density Br to the coercive force He, that is, Br (kG) / He (Oe) is 2 or more.

6. A steel slab consisting of 2 to 5% by weight of Ni force, 0.5 to 2% by weight in total of A1 and Ti, and the balance of Fe and unavoidable impurities was hot rolled and pickled. After that, primary cold rolling, then intermediate annealing at 700 to 900 ° C, and after secondary cold rolling, aging treatment at 400 to 70 ° C, the material for the mask for a color picture tube. Manufacturing method

7. N i is 2-5 wt ^_0/0, A 1 and T i is from 0.5 to 2 wt% in total of both, B is beyond 0.05 wt% 0 wt%, the balance being F e and A slab consisting of unavoidable impurities is hot-rolled, pickled, first cold-rolled, intermediately annealed at 700 to 900 ° C, and then secondarily cold-rolled, then aged at 400 to 700 ° C. A method for producing a material for a mask for a color picture tube, characterized by performing a treatment.

8. A force lamp using the material for a picture tube mask according to any one of claims 1 to 5. Mask for one picture tube.

9. The color picture tube mask according to claim 8, wherein the color picture tube mask is a stretchable color picture tube mask.

10. A color picture tube using the color picture tube mask according to claim 8.