KR20050077922A - Paste composite for printing of shadow mask of cathode ray tube and screen printing method using the same - Google Patents

Abstract

The present invention relates to a paste composition for shadow mask printing of a color cathode ray tube and a screen printing method using the same. The paste composition for shadow mask printing of a color cathode ray tube according to the present invention includes 50 to 100 parts by weight of frit, 10 to 70 parts by weight of organic binder, 50 to 300 parts by weight of solvent, based on 100 parts by weight of the electron reflecting material. , 1 to 30 parts by weight of a thermal radiation material, wherein the thermal radiation material is a chemical formula (A _1-y B _y O) _1-x (C _2-z D _z O _{3 + x} ) having a spinel or inverse spinel crystal structure A composite oxide to be represented, wherein x is 0 ≦ x <1, y is 0 ≦ y <1, z is 0 ≦ z ≦ 2, and A is a divalent cation Fe, Cr, Co, Mn, Cu , Zn is an element containing at least one selected from, and B, C and D is characterized in that the element containing at least any one selected from Fe, Mn, Cr of trivalent cations. As a result, it is possible to coat the shadow mask surface of the color cathode ray tube with a doping reduction coating film which has excellent electron reflection characteristics and can improve heat radiation characteristics and improve deterioration of conventional geomagnetic properties.

Description

Paste composition for shadow mask printing of color cathode ray tube and screen printing method using the same {Paste composite for printing of shadow mask of cathode ray tube and screen printing method using the same}

The present invention relates to a paste composition for shadow mask printing of a color cathode ray tube and a screen printing method using the same. More specifically, a doming phenomenon caused by thermal deformation of a shadow mask of a color cathode ray tube is compared with that of the conventional art. The present invention relates to a paste composition for shadow mask printing of a color cathode ray tube capable of reducing color purity of a color cathode ray tube and a screen printing method using the same.

1 is a side view illustrating a structure of a color cathode ray tube. As shown in the drawing, the color cathode ray tube 100 includes a panel 102 having a fluorescent film 101 formed on an inner side thereof and a graphite having conductivity on an inner side thereof. The coated funnel 103 is sealed with fusion glass, and the neck portion 104 of the funnel 103 corresponds to three pixels of three colors of R (red), G (green), and B (blue). The electron gun 106 which generates the electron beam 105 of this is mounted.

In addition, a plurality of slot or dot-shaped holes are arranged at positions close to the fluorescent film 101 such that the three-color electron beam 105 emitted from the electron gun 106 is an image plane, A shadow mask 110 is provided by the frame 107 to accurately reach the fluorescent film 101 formed inside the panel 102, and the electron beam 105 is deflected from side to side on the outer circumferential surface of the funnel 103. A deflection yoke 108 is provided. When the electron beam 105 passes through the hole of the shadow mask 110 and reaches the fluorescent film 101, the electron beam 105 is viewed from the panel 102 in order to prevent the electron beam 105 from being deflected due to the influence of geomagnetism. When the inner shield (109) is attached to the back of the frame 107 to shield the geomagnetic.

In this configuration, when an image signal is input to the electron gun 106, hot electrons are emitted from the cathode of the electron gun 106, and the emitted electrons are accelerated and focused toward the panel 102 by a voltage applied from each electrode of the electron gun 106. We will go through the process. At this time, the path of the electron beam 105 is adjusted by the magnetic field of the magnet mounted to the neck portion 104 of the panel 102, and the adjusted electron beam 105 of the panel 102 is deflected by the deflection yoke 108. It is scanned inside, about 20% of the deflected electron beam 105 passes through the hole (Hole) of the shadow mask 110 is subjected to color screening and the selected electron beam 105 is a fluorescent film (inside the panel 102) ( The video signal is reproduced by colliding with light 101).

In addition, the remaining 80% of the electron beam 105 collides with the surface of the shadow mask 110 to cause a temperature increase. Accordingly, the shadow mask 110 is thermally expanded, and thus the surface of the shadow mask 110 is swollen and the electron beam 105 is swelled. Doming phenomenon occurs, in which the landing position of the crankshaft changes. This doming phenomenon causes mislanding of the electron beam 105 to increase, which in turn leads to a decrease in purity called a purity drift.

Meanwhile, the high-purity low-carbon steel sheet, such as rimmed steel or aluminum killed steel, is used as the material of the shadow mask, which is subject to various conditions such as material supply capacity, price, workability, and strength. It is decided in consideration of these. However, this pure iron or aluminum-kilted steel has a high thermal expansion coefficient (for example, about 1.2 × 10 ⁻⁵ / ° C. at 0 to 100 ° C.), so that a shadow mask made of this material is thermally expanded in the screen direction. One doming phenomenon is severe. Therefore, in order to suppress the doming phenomenon, an invar alloy, which is a Fe-Ni alloy having a low thermal expansion coefficient, is used instead of aluminum killed steel as a material of the shadow mask. It is much more expensive than aluminum-kilted steel, so it is not economical and the mechanical workability is not good, so the annealing process temperature is very high above 900 ℃, and the process becomes complicated, such as the need to heat the mold during forming of the shadow mask. .

In addition to the method of using the shadow mask material as an inva alloy, various methods for suppressing the doming phenomenon have been proposed, and one of the representative examples is an electron on the surface of the shadow mask made of aluminum-kilted steel or invar alloy material. Coating the reflecting material (coating) to coat the dope reducing film. When the dope reducing coating layer is formed on the surface of the shadow mask with an electron reflecting material, the electrons injected from the electron gun are prevented from penetrating to the shadow mask to some extent, thereby suppressing heat generation of the shadow mask and thus reducing the dope phenomenon.

Here, referring to the method of coating the electron reflection material on the shadow mask surface, US Patent No. 3,562,518 in the spray mask method for forming an electron reflection material of bismuth oxide (Bi ₂ O ₃ ) and the glass component on the shadow mask surface A method has been proposed, and Japanese Patent Application Laid-Open No. 55-76553 proposes a method of forming an electron reflection material containing components such as tungsten (W), lead (Pb), bismuth (Bi) and the like by a spray method. They produce an electron reflection material in the form of a slurry and form an electron reflection film on the surface of the shadow mask by a spray method with a thickness of about 10 μm. However, this method has an electron reflection effect, but spraying 5mg / cm ² or more causes clogging of holes in the shadow mask or burrs on the surface of the holes. There is a problem in that exposure failure occurs due to the interference of light passing through the hole of the shadow mask or the electron beam is disturbed when passing through the hole.

Another method of coating the electronic reflective material on the shadow mask surface is to use a deposition method that targets the desired material as a source and targets the shadow mask, which is a coating material. There is a problem that the price is increased due to the deposition equipment.

Finally, the technology of coating the electronic reflective material on the surface of the shadow mask by using the screen printing method, in the Republic of Korea Patent Publication Nos. 1997-0063326 and 1998-006642 using a colorant, an electron reflecting material, a glass raw material By forming a doming reduction coating film on the mask, the electron reflection effect is achieved, and thereby the doming phenomenon is reduced. However, in the case of forming a dominant reduction coating film according to these techniques, the components or color may change during the manufacturing process of the color cathode ray tube, resulting in deterioration of quality. In addition, most materials reflect electron reflection only when the electrons are impulsed, and in the case of aluminum killed (AK steel) iron plate, electron reflection reflects about 25% of incident electrons. The above patents do not specifically limit this range of electron reflective materials.

In addition, Japanese Patent Application Laid-open No. Hei 10-275569 has introduced a paste composition in which Fe ₃ O ₄ powder is added to a conventional paste composition so as to have excellent electron reflection characteristics and improve thermal radiation characteristics. In general, however, the magnetic material used for the color CRT, unlike the situation which is required to the coercive force (Hc) is 2 Oe or less of Fe ₃ O ₄ Since the coercive force (Hc) is a quasi-ferromagnetic material with 10 to 50 Oe, when the dope reduction coating film is formed using the paste composition to which the Fe ₃ O ₄ powder is added, color purity is impaired by inhibiting the geomagnetic properties of the color cathode ray tube during operation There was a problem that is lowered.

As described above, in the paste composition for shadow mask printing of a conventional color cathode ray tube, when the electronic reflective material is coated on the shadow mask surface by the screen printing method, the electron reflection characteristic is excellent when the color brown tube is operated, but thermal radiation characteristics are inferior. In the case where the dope reducing coating layer was formed using the paste composition to which the Fe ₃ O ₄ powder was added, the thermal radiation characteristics could be improved while having excellent electron reflection characteristics. Since there was also a problem that the color purity is lowered.

On the other hand, in addition to the development of a printing paste composition that can solve the above problems, the development of a printing method that can minimize the production loss to the optimum quality when screen printing the dominant reduction coating film on the shadow mask using the printing paste composition It is also necessary.

Accordingly, an object of the present invention is to print a shadow mask of a color cathode ray tube, which can improve thermal radiation characteristics and improve deterioration of conventional geomagnetic properties, while having excellent electron reflection characteristics. It is to provide a paste composition.

In addition, another object of the present invention is to provide a screen printing method using a paste composition for printing a shadow mask of a color cathode ray tube, which is superior in quality and can reduce production loss.

The above object is, according to the present invention, 50 to 100 parts by weight of frit, 10 to 70 parts by weight of organic binder, 50 to 300 parts by weight of solvent, and 1 to 30 thermal radiation materials, based on 100 parts by weight of the electron reflecting material. Includes parts by weight, and the thermal radiation material is a complex oxide represented by the formula (A _1-y B _y O) _1-x (C _2-z D _z O _{3 + x} ) having a spinel or inverse spinel crystal structure, Wherein x is 0 ≤ x <1, y is 0 ≤ y <1, z is 0 ≤ z ≤ 2, and A is at least any one selected from Fe, Cr, Co, Mn, Cu, Zn of a divalent cation It is an element containing one, and B, C, and D are achieved by the shadow mask printing paste composition of the color cathode ray tube, characterized in that it is an element containing at least any one selected from Fe, Mn, and Cr which is a trivalent cation. .

Here, the electron reflecting material is preferably at least one selected from the group consisting of heavy metal elements having an atomic number of 55 or more and oxides thereof.

The electron reflecting material is more preferably at least one selected from the group consisting of bismuth, tungsten and oxides thereof.

In addition, the organic binder may be at least one selected from the group consisting of epoxy resin, ethyl cellulose and nitro cellulose.

The solvent is generally one of butyl carbitol and butyl carbitol acetate.

On the other hand, according to another field of the present invention, (a) transferring the shadow mask to the screen printing substrate; (b) applying a printing paste composition to the screen mesh on which the shadow mask pattern is formed; (c) disposing a shadow mask under the screen mesh to which the printing paste composition is applied, and then printing a dope reducing coating film in the direction of a stripe of the shadow mask while pressing the back yarn with a uniform pressure; And (d) drying the shadow mask on which the dominant reducing coating layer is formed, wherein the printing paste composition comprises 50 to 100 parts by weight of frit and an organic binder of 10 to 100 parts by weight of the electronic reflective material. 70 parts by weight, 50 to 300 parts by weight of a solvent, and 1 to 30 parts by weight of a thermal radiation material, wherein the thermal radiation material is a chemical formula (A _1-y B _y O) _1-x having a spinel or inverse spinel crystal structure. C _2-z D _z O _{3 + x} ), wherein x is 0 ≦ x <1, y is 0 ≦ y <1, z is 0 ≦ z ≦ 2, and A is bivalent Is an element containing at least one selected from Fe, Cr, Co, Mn, Cu, and Zn as a cation, and B, C, and D are elements containing at least one selected from Fe, Mn, and Cr as trivalent cations A screen printing method of a shadow mask of a color cathode ray tube is provided.

Here, the step (a), it is possible to reduce the defects caused by the foreign matter than the transfer using a vacuum adsorber than using a conventional electromagnet.

In addition, in step (c), the hardness of the back rubber may be 60 to 90 A to reduce wear due to friction between the shadow mask and the back rubber.

In the step (d), the drying is preferably performed at 150 to 220 ° C. for 5 to 10 minutes to prevent deterioration of the shadow mask.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The shadow mask printing paste composition of the color cathode ray tube according to the present invention is a chemical formula (A _1-y B _y O) _1-x having a chemically stabilized spinel or inverse spinel crystal structure (C _2-z D). _z O _{3 + x} ) to include the composite oxide to improve the heat radiation characteristics than conventional and to include an electron reflecting material of any one of the heavy metal element and the oxide of atomic number 55 or more to have excellent electron reflection characteristics In addition to having improved heat radiation characteristics and excellent electron reflection characteristics than the conventional, it is intended to not interfere with the geomagnetic characteristics of the color cathode ray tube during operation. Wherein x is 0 ≤ x <1, y is 0 ≤ y <1, z is 0 ≤ z ≤ 2, and A is at least any one selected from Fe, Cr, Co, Mn, Cu, Zn of a divalent cation An element containing one, B, C and D is an element containing at least any one selected from Fe, Mn, Cr of trivalent cations. The composition of the shadow mask printing paste composition of the color cathode ray tube according to the present invention is 50 to 100 parts by weight of frit, 10 to 70 parts by weight of the organic binder, and a solvent with respect to 100 parts by weight of the electron reflecting material. 50 to 300 parts by weight, and 1 to 30 parts by weight of the thermal radiation material.

First, as the electron reflecting material, a heavy metal element having an atomic number of 55 or more and an oxide thereof are used. In particular, bismuth, tungsten and oxides thereof are tungsten oxide (WO ₃ ).

The frit is printed on the shadow mask and then completely vitrified in the blackening process so that the electronic reflective material is not scattered, and furthermore, the frit is firmly attached to the shadow mask. If the amount of frit is too small, the fusion effect is lowered, resulting in film peeling of the coating, and too much frit reduces the effect of reducing the dominant phenomenon due to excessive organic matter. Limited to wealth.

In addition, the organic binder may be at least one selected from the group consisting of an epoxy resin, ethyl cellulose and nitrocellulose, and more preferably an epoxy resin.

The solvent is for dissolving the organic binder, specifically butyl carbitol or butyl carbitol acetate.

Finally, the thermal radiation material is a composite oxide represented by the formula (A _1-y B _y O) _1-x (C _2-z D _z O _{3 + x} ) with a spinel or inverse spinel crystal structure, where x is 0 ≤ x <1, y is 0 ≤ y <1, z is 0 ≤ z ≤ 2, A is at least any one selected from Fe, Cr, Co, Mn, Cu, Zn of a divalent cation Element, and B, C, and D are elements containing at least one selected from Fe, Mn, and Cr as trivalent cations. These composite oxides are chemically stable structures, and secondary changes such as color change or component change, which may cause quality deterioration, occur little during the manufacturing process of the shadow mask, and are generally black. In this operation, the thermal radiation characteristics can be improved as compared with the conventional one without disturbing the geomagnetic characteristics. If the thermal radiation material contained in the printing paste composition according to the present invention is 1 part by weight or less with respect to 100 parts by weight of the electronic reflective material, it is difficult to expect improvement of the thermal radiation property, and if it is 30 parts by weight or more, the relative content of the electronic reflective material with respect to the thermal radiation material. Since the electron reflection characteristic is lowered, or the fusion strength is lowered, the peeling tends to be reduced, and thus the peeling strength is limited to 1 to 30 parts by weight. Typical examples of thermal radiation materials include FeOCr ₂ O ₃ , Fe _1-x Cu _x OCr ₂ O ₃ may be mentioned.

With this configuration, the screen printing method of the shadow mask of the color cathode ray tube according to the present invention will be described with reference to FIG.

First, the shadow mask 10 is transferred to a screen printing substrate from a tray in which a centering pin is installed so that the shadow mask 10 can be positioned. At this time, instead of the conventional electromagnet, a vacuum adsorber is used, which is to prevent a phenomenon in which the shadow mask 10 is magnetized when a conventional electromagnet is used to cause a defect caused by a foreign substance.

Then, the printing paste composition according to the present invention described above is applied to the screen mesh 11 on which the shadow mask 10 pattern is plated. At this time, the printing paste composition may be previously applied to the screen mesh 11.

Then, as shown in FIG. 2, after placing the shadow mask 10 under the screen mesh 11 to which the printing paste composition is applied, the stripe of the shadow mask 10 is pressed while pressing the back rubber with a uniform pressure. A dope reducing film is printed in the stripe direction. Here, the hardness of the back rubber should be within 60 ~ 90A, which is to reduce the production loss by extending the working life by minimizing the wear due to the friction of the shadow mask 10 and the back rubber. In addition, the screen printing direction should be the direction of the stripe of the shadow mask 10. If the shadow mask 10 is crossed with the stripe, the friction between the back rubber and the shadow mask 10 is severe and the life is shortened. This is because the production yield is likely to decrease due to excessive staining.

Then, the shadow mask 10 in which the dope reducing coating film was formed is dried. Drying is performed for 5 to 10 minutes at 150 to 220 ° C, because the drying mask is higher than 220 ° C or when the time is longer than 10 minutes because the shadow mask 10 is deteriorated oxidation and yellowing problem. In addition, the mesh belt type drying furnace is most suitable for drying, and a hot air fan is installed inside to improve drying power. The dried complete shadow mask 10 is removed by using a vacuum adsorber and placed in a drinking tray.

 Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto.

Example 1

The composition of Example 1 according to the present invention includes 68 parts by weight of frit, 50 parts by weight of epoxy resin, 150 parts by weight of solvent, and 5 parts by weight of thermal radiation material with respect to 100 parts by weight of the electronic reflective material. Butyl carbitol is used as solvent, tungsten oxide (WO ₃ ) is used as electron reflecting material, FeOCr ₂ O ₃ , Fe _1-x Cu _x OCr ₂ O ₃ was used. This paste composition was printed in the stripe longitudinal direction on the small pore size portion of the shadow mask using a screen mesh to form a dope reducing film.

Example 2

The composition of Example 2 according to the present invention is the same except that the heat radiation material in the composition of Example 1 is changed to 10 parts by weight with respect to 100 parts by weight of the electron reflective material.

Example 3

The composition of Example 3 according to the present invention is the same except that the heat radiation material in the composition of Example 1 is changed to 15 parts by weight with respect to 100 parts by weight of the electron reflective material.

The composition of Examples 1 to 3 described above was coated on the shadow mask surface to form a dominant reduction coating film, and the thermal emissivity and the local dominant amount (μm) of each of them were measured and shown in Table 1 below. Here, the thermal emissivity is the value measured through FT-IR in the 7.7 micrometer wavelength band and 100 degreeC heating state. For reference, the conventional thermal emissivity was about 0.780 level.

Thermal emissivity Local Domming Amount (μm) Example 1 0.792 550 Example 2 0.820 510 Example 3 0.843 490

As can be seen in Table 1 above, when the printing paste composition of Examples 1 to 3 according to the present invention was printed on the shadow mask surface to form a dope reducing coating layer, 0.792 higher than the conventional thermal emissivity of 0.780. The thermal emissivity was gradually increased to 0.843, and the doming amount was gradually decreased from 550㎛ to 490㎛.

As described above, the paste composition for shadow mask printing of a color cathode ray tube may be obtained by chemical formula (A _1-y B _y O) _1-x having a chemically stable spinel or inverse spinel crystal structure (C _2-z D _z O _{3 + x).} It is composed of a compound oxide represented by the (), and comprises a heavy metal element having an atomic number of 55 or more and an electron reflecting material of any one of the oxides at the same time has the improved thermal radiation characteristics and excellent electron reflecting characteristics and at the same time operating the color cathode ray tube It does not interfere with geomagnetic characteristics.

In the above-described embodiments, the shadow mask of the color brown tube is described above, but the shadow mask of the CDT (Color Display Tube) and the CPT (Color Picture Tube) is a flat tension mask (Flat Tension Mask) in flattron. ), As well as the shadow mask of the color cathode ray tube that accurately lands the electron beams to the corresponding phosphors on the screen, such as gate metal of a field emission display (FED), to obtain a desired color image. Of course, it can be variously applied to these.

As described above, according to the present invention, a shadow mask printing paste composition of a color cathode ray tube, which has excellent electron reflection characteristics and improves thermal radiation characteristics and improves deterioration of conventional geomagnetic characteristics, Is provided.

In addition, there is provided a screen printing method using a paste composition for printing a shadow mask of a color cathode ray tube, which is superior in quality and can reduce production loss.

1 is a side cross-sectional view showing the structure of a color cathode ray tube;

2 is a view for explaining a screen printing method using the paste composition for shadow mask printing of the color cathode ray tube according to the present invention.

* Explanation of symbols for main parts of the drawings

 10: shadow mask 11: screen mesh

 100: color cathode ray tube 101: fluorescent film

 102 panel 103: funnel

 104: neck portion 105: electron beam

 106: electron gun 107: frame

 108: deflection yoke 109: inner shield

Claims (9)

50 to 100 parts by weight of frit, 10 to 70 parts by weight of organic binder, 50 to 300 parts by weight of solvent, and 1 to 30 parts by weight of thermal radiation material, based on 100 parts by weight of the electron reflecting material, The thermal radiation material is a complex oxide represented by the formula (A _1-y B _y O) _1-x (C _2-z D _z O _{3 + x} ) having a spinel or inverse spinel crystal structure, where x is 0 ≦ x <1, y is 0 ≦ y <1, z is 0 ≦ z ≦ 2, and A is an element containing at least one selected from Fe, Cr, Co, Mn, Cu, and Zn of a divalent cation And, B, C and D is a shadow mask printing paste composition for a color cathode ray tube, characterized in that the element containing at least any one selected from among the trivalent cations Fe, Mn, Cr. The method of claim 1, The electron reflecting material is at least one selected from the group consisting of a heavy metal element of atomic number 55 or more and an oxide thereof, the shadow mask printing paste composition of the color cathode ray tube. The method of claim 3, The electron reflecting material is at least one selected from the group consisting of bismuth, tungsten and oxides thereof. The method of claim 1, The organic binder is at least one selected from the group consisting of epoxy resin, ethyl cellulose and nitro cellulose, the shadow mask printing paste composition of the color cathode ray tube. The method of claim 1, The solvent is a paste composition for shadow mask printing of the color cathode ray tube, characterized in that any one of butyl carbitol and butyl carbitol acetate. (a) transferring the shadow mask to the screen printing substrate; (b) applying a printing paste composition to the screen mesh on which the shadow mask pattern is formed; (c) disposing a shadow mask under the screen mesh to which the printing paste composition is applied, and then printing a dope reducing coating film in the direction of a stripe of the shadow mask while pressing the back yarn with a uniform pressure; And (d) drying the shadow mask on which the dope reducing coating layer is formed; The printing paste composition includes 50 to 100 parts by weight of frit, 10 to 70 parts by weight of organic binder, 50 to 300 parts by weight of solvent, and 1 to 30 parts by weight of thermal radiation material based on 100 parts by weight of the electron reflecting material. , The thermal radiation material is a complex oxide represented by the formula (A _1-y B _y O) _1-x (C _2-z D _z O _{3 + x} ) having a spinel or inverse spinel crystal structure, where x is 0 ≦ x <1, y is 0 ≦ y <1, z is 0 ≦ z ≦ 2, and A is an element containing at least one selected from Fe, Cr, Co, Mn, Cu, and Zn of a divalent cation And B, C, and D are elements including at least one selected from Fe, Mn, and Cr as trivalent cations. The method of claim 6, Step (a), the screen printing method of the shadow mask of the color cathode ray tube, characterized in that the transfer using a vacuum adsorber. The method of claim 6, The screen printing method of the shadow mask of the color cathode ray tube, characterized in that the hardness of the rubber in the step (c) is 60 ~ 90A. The method of claim 6, Drying in the step (d) is the screen printing method of the shadow mask of the color cathode ray tube, characterized in that performed for 5 to 10 minutes at 150 ~ 220 ℃.