ANTI-DOME COMPOSITIONS FOR A SHADOW MASK AND PROCEPSHSENT TO PREPARE THE, Ml ^
l) CwwQ < The present invention is related to an anti-dome composition for shadow mask, particularly it relates to 1) an anti-dome composition that includes a mixture of electron reflecting material such as this. or bismuth oxide, and a zeolite to restrict temperature increase when coating the shadow mask composition for a CRT (cathode-ray tube), 2) an anti-dome composition that includes lead (Pb) and at least one of ZnO, Ba, 03 and Bi2? 3 to protect material expansion from a shadow mask and to restrict temperature increases when coating the shadow mask composition for a CRT, 3) an anti-dome composition including ferroelectric as PZT (PbZrTi03), PT (PbTi03), PZ (PbZr03) or PLZT [(PbLa) (ZrTi) 03] to restrict temperature increase by coating the composition in the shadow mask for a CRT to change the beam energy of the electrons in non-thermal energy and a p Procedure to prepare it. 2) Description of Related Art In a TRC of conventional shadow mask type, the graphic images are reproduced by red, green / and blue electron beams emitted from means to produce them. The electron beams pass through a hole in a shadow mask, converge at a point, and collide with red, green, and blue phosphors formed on a phosphor screen on an interior surface of a panel. The shadow mask used in the color CRT has a role in choosing electron beams for a particular color between the electron beams emitted from an electron gun. The shadow mask is usually produced with an AK steel (weakened with aluminum) that has hundreds of thousands and tens of thousands of holes formed by photolithography. A general procedure for preparing the shadow mask is described more particularly below. To allow a flatness and property of setting to a mask panel, an AK steel is subjected to a roller leveling treatment, causing a plastic deformation. Subsequently, the procedure for preparing holes in the mask panel is performed by photolithography. The photolithography process is carried out with the coating sequence of a photo-hardening material, exposure, development and etching of the panel. According to the etching procedure, the panel has a number of orifices passing electron beams. The panel having holes is heat treated in a high temperature gas and hydrogen gas to give ductility (annealing process) and then a forming process is performed to change the panel in a certain way by a press. After the forming process, the panel is subjected to a degreasing process, to remove impurities connected to the surface of the panel. Subsequently, a blackening procedure is performed to improve the anti-dome property of the shadow mask. Approximately 20% of the electron beams emitted from an electron gun and reaching the shadow mask pass through the shadow mask and cause a phosphor screen luminescence. And, approximately 80% of the remaining electron beams are absorbed in the shadow mask and cause the thermal expansion of the shadow mask. In this circumstance, the temperature of the shadow mask increases to approximately 80 to 90 ° C. As mentioned earlier, we call the thermal expansion of a shadow mask as a dome phenomenon. The dome phenomenon results in movement of the holes in the shadow mask, which induces a change in luminescence positions, further provoking luminescence of different colors. Consequently, the dome phenomenon decreases the purity of color of the TRCs. In accordance with the requirement to avoid the dome phenomenon, various types of anti-dome methods have been developed. Japanese patent publication No. sho 59-15861; The patents of the U.S.A. Nos. 4665338 and 4528246 describe procedures for preparing CRTs using a shadow mask that is produced with an Invar steel to avoid color purity decrement according to the dome phenomenon. Invar steel shows a preferable anti-dome property because it has 1/10 of expansion coefficient of an AK steel, 11.7 X 10 - 10 ~ 6 / K. Therefore, Invar steel is usually used as a material of a shadow mask for TRCs of more than 38.2 cm (15 inches). However, Invar steel has problems of high cost and difficulty during procedures. Korean patent application No. 86-1589 describes a reflecting electron layer coated on one side of an electron gun with heavy metals such as lead (Pb), bismuth (Bi) and tungsten (W) by an aqueous emulsion method to reduce the heating caused by the electron beams. However, the metal layer can not be easily coated, and the anti-dorao ratio is only about 30%, and the method described has a problem of adjusting to a practical mass production. Additionally, the tungsten layer is usually oxidized over 300"C. Therefore, the layer has a vigorous oxidation problem at the temperature of about 450 ° C which is reached in the baking and sealing process. To solve the above problems, the present invention provides an anti-dome composition for a shadow mask having an anti-dome ratio of approximately 30 to 50%, by restricting the temperature increase by preventing shadow mask expansion mechanically or by changing The energy of the electron beam in non-thermal energy, and a method for preparing the same, In addition, the shadow mask of the present invention has a low cost of production and comfort during additional procedures, objectives, advantages and novel features of the invention. invention will be established in part in the description that follows, and in part will be apparent to those with skill in the specialty, when examining the following or can be learned by practice of the invention. The object and advantages of the invention can be achieved and achieved by means and combinations particularly pointed out in the appended claims. In the following detailed description, only the preferred embodiment of the invention has been illustrated and described, simply by way of illustration of the best mode contemplated by the inventor or inventors to carry out the invention. As will be considered, the invention is capable of modifying into various, all without departing from the invention. According to this, the description should be considered as illustrative in nature, and not as restrictive. DESCRIPTION OF THE INVENTION To achieve the above objectives, the present invention provides an anti-dome composition for a shadow mask comprising a vehicle and a zeolite, and also provides an anti-dome composition for a shadow mask comprising a vehicle, an electron reflective material selected from the group consisting of bismuth oxide, tungsten oxide and lead, and a zolstite. And the present invention provides a shadow mask comprising a steel layer having a plurality of holes for passing electron beams and a coating layer formed in the steel layer when using the anti-dome composition. It is preferable that in an amount the zeolite is from 10 to 90% by weight of the total amount of the composition and the coating layer is prepared by a stencil printing method and has a thickness of 3 to 30 μm. The present invention provides a shadow mask comprising a steel layer having a plurality of holes for passing electron beams, a first coating layer formed in the steel layer by using an anti-dome composition including a zeolite and a second coating layer formed in the first layer by using an anti-dome composition that includes an electron reflective material selected from the cosmic group of bismuth oxide, tungsten oxide and lead. It is preferable that the first and second coating layers are prepared by a stencil printing method and have a thickness of 3 to 30 μm. The present invention provides a method for preparing an anti-dome composition for a shadow mask comprising the steps of mixing a vehicle and a zeolite, and also providing a method for preparing an anti-dome composition for a shadow mask comprising the steps of mixing a vehicle, an electron reflective material selected from the group consisting of bismuth oxide, tungsten oxide and lead, and a zeolite. In a method for preparing a shade mask comprising the steps of preparing a steel layer with a plurality of holes for passing electron beams and coating an anti-dome composition to produce a coating layer in the steel layer, the improvement of the present invention is that the anti-dome composition includes an electron reflective material selected from the group consisting of bismuth oxide, tungsten oxide and lead and / or a zeolite. In a method for preparing a shadow mask comprising the steps of preparing a steel layer having a plurality of holes for passing electron beams and coating an anti-dome composition to produce a coating layer on the steel layer, the improvement of the present invention is to form a first coating layer prepared from a zeolite in the steel layer and form a second coating layer prepared from an electron reflecting material selected from the group consisting of bismuth oxide, of tungsten and lead in the first coating layer. It is preferable that an amount of the zeolite is 10 to 90% by weight of the total amount of the composition and the respective coating layer is prepared by a stencil printing method and has a thickness of 3 to 30 μra. The present invention provides an anti-dome composition for a shadow mask comprising a vehicle, lead and at least one compound selected from the group consisting of ZnO, B203 and Bi203. It is preferable that an amount of the compound selected from the group consisting of ZnO, B203 and Bia03 is 5 to 50% by weight of the total amount of the composition. The present invention also provides a shadow mask comprising a steel layer having a plurality of holes for passing electron beams and a coating layer using the above anti-dome composition. It is preferable that the coating layer be prepared by a stencil printing method and having a thickness of 3 to 30 μm. The present invention provides a method for preparing an anti-dome composition for a shadow mask comprising the steps of mixing a vehicle, lead and at least one compound selected from the group consisting of ZnO, B203 and Bi203. It is preferable that the amount of the compound selected from the group consisting of ZnO, B203 and Bi203 be 5 to 50% by weight with respect to the total amount of the composition. In a method for preparing a shade mask comprising the steps of preparing a steel layer having a plurality of holes for passing electron beams and coating an anti-dome layer to produce a coating layer in the steel layer , the improvement of the present invention is that the anti-dome composition includes at least one compound selected from the group consisting of ZnO, B203 and Bi203. It is preferable that the coating layer be prepared by a stencil printing method and have a thickness of 3 to 30 μm. The present invention provides an antidomain composition for a shadow mask comprising a carrier and at least one compound selected from the group consisting of PZT (PbZrTi? 3), PT (PbTi? 3), PZ (PbZr? 3) and PLZT [ (PbLa) (ZrTi) 03]. It is preferable that an amount of the compound selected from the group consisting of PZT, PT, PZ and PLZT is 30% weight or more with respect to the total amount of the composition. The present invention also provides a shadow mask comprising a steel layer having a plurality of holes for passing electron beams and a coating layer using the above anti-dome composition. It is preferable that the coating layer be prepared by a stencil printing method and have a thickness of 3 to 30 μm. The present invention provides a method for preparing an anti-dorao composition for a shadow mask comprising the steps of mixing a vehicle and at least one compound selected from the group consisting of PZT, PT, PZ and PLZT. It is preferable that an amount of compound selected from the group consisting of PZT, PT, PZ and PLZT is 30% by weight or more relative to the total amount of the composition. In a method for preparing a shadow mask comprising the steps of preparing a steel layer having a plurality of holes when passing electron beams and coating an anti-dome layer to produce a coating layer in the steel layer, The improvement of the present invention is that the anti-dome composition includes at least one compound selected from the group consisting of PZT, PT, PZ and PLZT. It is preferable that the revetment layer be prepared by a stencil printing method and have a thickness of 3 to 30 μm. DESCRIPTION PCTftMAlflA T) K h S MQPMPftfflSS, PHPERi g. [Prepare an anti-dome composition using an electron reflecting material and a zeolite] An electron reflecting material such as bismuth oxide, tungsten oxide or lead, is mixed with a zeolite to produce a mixture. An epoxy-based vehicle is added to the mixture to produce an anti-dome type paste composition for a shade mask. To avoid particle separation after the blackening and baking procedures, an appropriate amount of a low melting point frit is added to the composition. A zeolite that has a chemical formula of Na12 [(A102) 12 Si02) 12] XHaO is a clay mineral widely used. The zeolite has micro pores in such a way that it is used as an absorbent, carrier of enzymes, insulating material, etc. In the present invention, the zeolite is used as an insulating material to avoid heat transfer caused by electrons colliding with a shadow mask. Bismuth oxide has a role of restricting temperature increase by reflecting many electron beams emitted from an electron gun before colliding the shadow mask, because it has a high reflective coefficient of electrons. The above coating composition is coated in the shade mask which is passed through an annealing process by a screen printing method. By adjusting a blackening procedure, the shadow mask having a coating layer to avoid a dome phenomenon has an improved anti-dome property. [Prepare an anti-dome composition using lead ZnO, B203 and Bi203] ZnO, B203 and Bi203 are added to lead to produce a mixture. An epoxy-based vehicle is added to the mixture to produce an anti-dome type paste composition for a shadow mask. Lead has the role of restricting the increase in temperature by reflecting many of the electron beams emitted from an electron gun before colliding the shadow mask because it has a high electron reflecting coefficient. And ZnO, B203 and Bi203 have a thermal expansion role of the shadow mask because they have a low coefficient of expansion. The above coating composition is coated in the shade mask which is passed through an annealing process by a screen printing method. By adjusting a blackening procedure, the shadow mask having a coating layer to avoid a dome phenomenon has an improved anti-dome property. According to the previous procedure, the lead melts and wraps particles of ZnO, B203 and Bi203 in such a way that the breakdown of the particles is avoided in the following procedures. [Prepare an anti-dome composition when using PZT, PT, PZ and PLZT] An epoxy-based vehicle is added to PZT, PT, PZ, PLZT or its mixture to produce a paste-type anti-dome composition for a shade mask. To avoid breakage of the particles after the blackening and baking procedures, an appropriate amount of a low melting point frit is added to the composition. PZT, PT, PZ, PLZT or a mixture of them that has piezoelectric effects, and pyroelectric has a role to restrict the temperature increase of the shadow mask by changing the energy of the electron beams into non-thermal energy. The above coating composition is coated in the shade mask which is passed through an annealing process by a screen printing method. By adjusting a blackening procedure, the shadow mask having a coating layer to avoid a dome phenomenon has more improved anti-dome properties. According to the above procedure, the frit melts and wraps the PZT, PT, PZ, particles of PLZT in such a way that breaking of the particles is avoided in the following procedures. Preferable examples and reference example are described below. These examples are illustrative only and the present invention is not restricted to the scope of the examples. EXAMPLE 1 16 g of butyl carbitol and 4 g of epoxy resin are mixed to prepare a vehicle. 20 g of the zeolite are added to 40 g of bismuth oxide particles, and then 20 g of frit are added to produce mixed particles. The mixed particles were added to the vehicle to produce an anti-dome composition for a shadow mask of the present invention. The above coating composition is coated in the shade mask which is passed through an annealing process by a screen printing method in a thickness of 20 μm of a coating layer. By adjusting a blackening process with a temperature of 570 bc, the shadow mask having a coating layer to avoid a dome phenomenon has even more improved anti-dome properties.
16 g of butyl carbitol and 4 g of epoxy resin are mixed to prepare a vehicle. 10 g of the zeolite is added to 50 g of lead particles and then 20 g of frit are added to produce mixed particles. The mixed particles were added to the vehicle to produce an anti-dorao composition for a shadow mask of the present invention. The above coating composition is coated in the shade mask which is passed through an annealing process by a screen printing method in a thickness of 20 μm of a coating layer. By adjusting a blackening process with a temperature of 570 ° C, the shadow mask that has a coating layer to avoid a dome phenomenon, has even more improved anti-dome property, f grotop 16 g of butyl carbitol and 4 g of resin Epoxy are mixed to prepare a vehicle. 10 g of zeolite is added to 60 g of tungsten oxide particles and then 10 g of frit are added to produce mixed particles. The mixed particles are added to the vehicle to produce an anti-dorao composition for a shadow mask of the present invention. The above coating composition is coated in the shade mask which is passed through an annealing process by a screen printing method in 15 μm thickness of a coating layer. By adjusting a blackening process with a temperature of 570 ° C, the shadow mask having a coating layer to avoid a dome phenomenon has an even more improved anti-dome property. EXAMPLE 4 16 g of butyl carbitol and 4 g of epoxy resin are mixed to prepare a vehicle. 40 g of frit are added to 40 g of zeolite to produce mixed particles. 16 g of frits are added to 64 g of bismuth oxide particles to produce other mixed particles. The mixed particles are respectively added to the vehicle, to produce anti-dome compositions for a shadow mask of the present invention. The coating composition having the zeolite is coated in the shade mask which is passed through an annealing process by a screen printing method in the thickness of 10 μm of a first coating layer. With the same method, the coating composition having bismuth oxide is coated in the first coating layer. By adjusting a blackening procedure with a temperature of 570 ° C, the shadow mask that has the two coating layers to avoid a dome phenomenon, has more improved anti-dome properties. E CTplP 5 16 g of butyl carbitol and 4 g of epoxy resin are mixed to prepare a vehicle. 40 g of frit are added to 40 g of the zeolite to produce mixed particles. 20 g of frit are added to 64 g of lead particles to produce other mixed particles. The mixed particles were respectively added to the vehicle to produce anti-dome compositions for a shadow mask of the present invention. The coating composition having the zeolite is coated in the shade mask which is passed through an annealing process by a screen printing method in the thickness of 10 μm of a first coating layer. With the same method, the coating composition having lead is coated in the first coating layer. By adjusting a blackening process with a temperature of 57 ° C, the shadow mask having the two coating layers to avoid a dome phenomenon has more improved anti-dome properties Example 6 16 g butyl carbitol and 4 g of epoxy resin are mixed to prepare a vehicle 40 g of frit are added to 40 g of the zeolite to produce mixed particles 30 g of frit are added to 50 g of tungsten oxide particles to produce other mixed particles. mixed particles are respectively added to the vehicle to produce anti-dome compositions for shadow mask of the present invention The coating composition having the zeolite is coated in the shadow mask which is passed through an annealing process by a method of stencil printing in 10 μm thickness of a first coating layer, with the same method, the coating composition having tungsten oxide is coated in the first coating layer. By adjusting a blackening procedure with a temperature of 570 ° C, the shadow mask that has the two coating layers to avoid dome phenomenon, has more improved anti-dome properties. EXpffiPlQ, 16 g of butyl carbitol and 4 g of epoxy resin are mixed to prepare a vehicle. 40 g of frit are added to 40 g of the zeolite to produce mixed particles. The mixed particles were added to the vehicle to produce an anti-dome composition for a shadow mask of the present invention. The above coating composition is coated in the shade mask which is passed through an annealing process by a screen printing method in a thickness of 10 μm of a coating layer. By adjusting a blackening procedure with a temperature of 570 ° C, the shadow mask that has the coating layer to avoid a dome phenomenon, has more improved anti-dome properties. Example 8 16 g of butyl sarbitol and 4 g of epoxy resin are mixed to prepare a vehicle. 40 g of ZnO are added to 40 g lead particles to produce mixed particles. The mixed particles were added to the vehicle to produce an anti-dome composition for a shadow mask of the present invention. The above coating composition is coated on the shade mask which is passed through an annealing process by a screen printing method in a thickness of 20 μm of a coating layer. By adjusting a blackening process with a temperature of 570 ° C, the shadow mask that the coating layer has to avoid a dome phenomenon has more improved anti-dome properties. Example 9 16 g of butyl carbitol and 4 g of epoxy resin are mixed to prepare a vehicle. 20 g of ZnO are added to 60 g lead particles to produce mixed particles. The mixed particles were added to the vehicle to produce an anti-dome composition for a shadow mask of the present invention. The above coating composition is coated on the shade mask which is passed through an annealing process by a screen printing method in a thickness of 20 μm of a coating layer. By adjusting a blackening procedure with a temperature of 570"c, the shadow mask that the coating layer has to avoid a dome phenomenon has more improved anti-dome properties Example 10 16 g of butyl carbitol and 4 g of Epoxy resin is mixed to prepare a vehicle 16 g of frit are added to 64 g of PZT particles to produce mixed particles The mixed particles are added to the vehicle to produce an anti-dome composition for a shadow mask of the present invention. The above coating composition is coated in the shade mask which is passed through an annealing process by a screen printing method in a thickness of 20 μm of a coating layer. 570"C, the shadow mask that has the coating layer to avoid dome phenomenon, has more improved anti-dome properties. Example 11 16 g of butyl carbitol and 4 g of epoxy resin are mixed to prepare a vehicle. 8 g of frit are added to 72 g of PZT particles to produce mixed particles. The mixed particles are added to the vehicle to produce an antidomain composition for a shadow mask of the present invention. The above coating composition is coated in the shade mask which is passed through an annealing process by a screen printing method in 25 μm thickness of a coating layer. By adjusting a blackening procedure with a temperature of 570"c, the shadow mask that has the coating layer to avoid a dome phenomenon, has more improved anti-dome properties. Reference Example 1 A shadow mask is prepared with the same method of Example 1 except that the coating layer is not formed. A dome proportion in general is determined by measuring a maximum distance between an unheated beam position and the beam position when heated and displaying a dome phenomenon. Dome formation rates of the 63.5 cm (25") steel AK masks coated with the composition according to the Examples and Reference Example are illustrated in the following Table 1. TABLE 1 Maximum Amount of Dome Training Ratio Dome reduction (μm), Example 1 40 33.3 Example 2 42 30.0 Example 3 35 41.7 Example 4 35 41.7 Example 5 38 36.7 Example 6 30 50.0 Example 7 40 33.3 Example 8 35 41.7 Example 9 40 33.3 Example 10 38 36.7 Example 11 36 40.0 Reference Example 60 As a result of preparing the anti-dome compositions and shadow masks coated with the compositions according to the Examples and the Reference Example, the shadow masks of Examples 1 to 7 reduce the dome ratio to approximately 30 to 50% compared to the shadow mask of the Reference Example because the shadow masks of Examples 7 restrict the temperature increase by a reflection effect of electrons caused by electron reflecting materials and an insulating effect caused by the zeolite. In addition, the shadow masks produced with the procedure of Examples 1 to 7 have low production costs and ease during the procedures. A type 4A zeolite is used in the Examples, however we were able to obtain the same results when using type 3A, 5A and X zeolites having the same molecular structure as the type 4A zeolite but different micro-pore size. The shadow masks of Examples 8 and 9 reduce the dome ratio to about 30 to 40% or more compared to the shadow mask of the Reference Example by restricting the temperature increase. And the shadow masks produced with the procedure of Examples 8 and 9 also have low production cost and ease during processing. The shadow masks of Examples 10 and 11 reduce the ratio of domes to approximately 30 to 40% compared to the shadow mask of the Reference Example by restricting the temperature increase. And the shadow masks produced with the procedure of Examples 10 and 11 also have low production costs and ease during processing.
In this description, only the preferred embodiment of the invention is illustrated and described, but as mentioned above, it will be understood that the invention is capable of being used in various other combinations and environments and is capable of changes or modification within the scope of the invention. inventive concepts expressed here.