MXPA99007763A - Composition to form a conductive layer and cathode rays tube that uses such formed layer from the composite - Google Patents

Abstract

A composition is provided to form a conductive layer comprising 0.01-0.1% by weight of a conductive black pigment, 0.05-10% by weight of a binder, 0.01-50% by weight of a conductive agent, and the remaining amount of a solvent based on the total weight of the composition, and a cathode ray tube (CRT) having the conductive layer formed by coating the composition on the outer surface of a panel, drying and heating thereof, and a formed protective layer on the conductive layer. The conductive layer formed using the composition has excellent conductivity, contrast characteristics and film properties. In addition, you can obtain a clean color purity and a high quality body color

Description

COMPOSITION TO FORM A CONDUCTIVE LAYER AND CATHODIC RAYS TUBE THAT USES SUCH LAYER FORMED TO LEAVE OF THE COMPOSITION BACKGROUND OF THE INVENTION 1. Field of Invention The present invention relates to a composition for forming a conductive layer, and more particularly, to a composition for forming a conductive layer having excellent conductivity and contrast characteristics, and a cathode ray tube (CRT) having the conductive layer formed using the previous composition. 2. Description of the Related Art.

The fundamental principle of a CRT is based on the fact that a beam of electrons is emitted from an electron gun and is selectively deflected by a deflection yoke according to the positions of incidence, and falls on a layer of phosphorus formed on the inner surface of a panel and in this way excites the phosphor causing it to shine, so that an image is formed. Regarding the panel for a CRT, it is typically REF .: 30998 uses a curved panel that has a predetermined curvature. Although the curved panel has the disadvantage from the point of view of acquiring a high quality image, it causes severe brilliance and image distortion in the peripheral portion thereof, still used largely as a panel for a CRT due to the technical difficulty in making flat panels. However, according to recent advances in flat panel technology, existing curved panels are replaced by flat panels that have a curvature close to infinity. A panel that has a large curvature, this, an almost flat panel, can generate a clean image by suppressing the brightness due to external light reflection, reduced fatigue of the eye and avoiding distortion of an image. As an example of a flat panel, a panel has been proposed in Figure 1, whose inner and outer surfaces are both completely planar. In a CRT that uses such a flat panel, an "image is formed in the central portion of the panel and appears to recede in. To solve this problem, as shown in Figure 2, a flat panel having an external surface has been proposed. completely flat and a curved inner surface having a predetermined curvature.

However, according to this flat panel, it is difficult to obtain a uniform image due to the different transmittances between the central portion and the peripheral portion of the panel, which is caused by a difference in thickness. Furthermore, in the case of using a generally dark ink panel or a semitinta panel having a transmittance of about 40-50% as the flat panel, the difference in the transmittances between the central portion and the peripheral portion of the panel is they become bigger. Therefore, according to the present invention, a method has been proposed for solving the above-mentioned problems, by means of which a transparent panel having a transmittance of 80% or more, and a conductive layer for use as a flat panel is used adjust the transmittance and improve the contrast characteristics which is covered on the external surface of the same.

BRIEF DESCRIPTION OF THE INVENTION To solve the above problems, an object of the present invention is to provide a composition for forming a conductive layer having excellent conductivity and contrast characteristics.

Another object of the present invention is to provide a cathode ray tube using the conductive layer formed using the composition. Accordingly, to obtain the first objective, a composition is provided to form a conductive layer which includes 0.01-1.0% by weight of a conductive black pigment, 0.05-10% by weight of a binder, 0.01-50% by weight of a conductive agent, and the remaining amount of a solvent based on the total weight of the composition. To obtain the second objective, a cathode ray tube including a panel, and a conductive layer and a protective layer formed sequentially on the outer surface of the panel is provided, wherein the conductive layer is prepared by coating the composition to form a layer. conduxa mentioned above on the outer surface of the panel, coat, dry and heat it.

BRIEF DESCRIPTION OF THE DRAWINGS The above objects and advantages of the present invention will become apparent when a preferred embodiment of the invention is described in detail. The. same, with reference to the accompanying drawings, in which: Figure 1 is a sectional view illustrating an example of a general planar panel; Figure 2 is a sectional view illustrating another example of a general planar panel; and Figure 3 is a sectional view illustrating a cathode ray tube using a flat panel on which a conductive layer is formed in accordance with the present invention.

DESCRIPTION OF THE PREFERRED MODALITIES A composition for forming a conductive layer according to the present invention includes 0.01-1.0% by weight of a conductive black pigment, 0.05-10% by weight of a binder, 0.01-50% by weight of a conductive agent, and the amount remaining of a solvent based on the total weight of the composition. In the composition, the conductive black pigment is selected from at least the group consisting of carbon black and titanium black, and the average particle diameter thereof is 200 nm or less, and more preferably 120 nm or more. less. In addition, the binder is at least one which is selected from a silane coupling agent such as epoxysilane, trimethoxysilane or vinylsilane, a metal alkoxide represented by the formula (1) and a silicon alkoxide oligomer represented by the formula ( 2) : Formula (1): [i (OR) wherein Mx is one that is selected from the group consisting of Si, Ti, Sn, Zr and Ce, R may be the same or different from each other and is a C ^ C alkyl, ,, and m is an integer that is selected from 4 to 6; Formula (2): (SiO) n (OR) 4.2n wherein n is in the range of 0.5-1.5, R is a C1-C4 alkyl, and the average molecular weight is 400-6000. If the average molecular weight of the silicon alkoxide oligomer represented by the formula (2) is less than 400, the hardness of the film decreases. On the other hand, if the average molecular weight of the silicon alkoxide oligomer is greater than 6000, the viscosity of the composition is increased. In addition, the conductive agent is preferably at least one which is selected from the group consisting of metal, metal oxide and a conductive polymer. Here, metal and metal oxide are not specifically restricted insofar as they have been widely used in the art and have an average particle diameter of 200 nm or less, and more preferably 120 nm or less. In detail, the metal includes silver (Ag), gold (Au), platinum (Pt), copper (Cu), nickel (Ni), palladium (Pd), cobalt (Co), rhodium (Rh), ruthenium (Ru) and tin (Sn), and the metal oxide includes tin oxide, indium oxide and tin indium oxide (ITO), antimony oxide, antimony and zinc oxide and antimony and tin oxide. In addition, the conductive polymer is a polymer that has a p-resonance structure and is not specifically restricted to the extent that it is widely used in the art. Detailed examples of the conductive polymer include polypyrrole, polyacetylene, polyfuran, polyparaphenylene, polyselenophen, polythiophene, polyaniline and the like, and derivatives thereof having side chain substitutes or functional additives, may also be used. As the solvent, an alcohol solvent such as methanol, ethanol, isopropyl alcohol N-butanol or N-methyl-2-pyrrolidone (NMP), dimethylformamide or water can be used alone or in combination. A pigment can be added to the composition to adjust wavelengths to form the conductive layer according to the present invention so as to correct the color sensitivity of the black pigments, and thereby improve the color purity of an image or get a high quality body color. Here, the pigment for adjusting wavelengths are preferably organic or inorganic pigments which exhibit excellent transmittance in the range of 400-700 nm and which have an average particle diameter of 200 nm or less, more preferably 120 nm or less. The content of the pigment is preferably 0.005-0.3% by weight based on the total weight of the composition to form the conductive layer. The pigment for adjusting wavelengths can be added to the composition to form the conductive layer according to the present invention together with a suitable dispersing agent such as compounds containing sulfone groups. Otherwise, the pigment can be added in the form of a pigment composition containing a pigment for adjusting wavelengths, a suitable dispersing agent and a conductive polymer. The pigment composition includes 0.3-30% by weight of a pigment to adjust the wavelength, 0.24-1.2% by weight of a dispersing agent, 5-50% by weight of a conductive polymer and the remaining amount of solvent, based on in the total weight of the pigment composition, and can be prepared by dissolving the pigment to adjust the wavelength and the dispersing agent in an organic mixture solvent containing the conductive polymer, mechanically dispersing and then grinding by means of waves Ultrasonics to the same for 0.5-4 hours. A cathode ray tube (CRT) according to the present invention includes a panel, and a conductive layer and a protective layer formed sequentially on the outer surface of the panel, wherein the conductive layer is prepared by coating the composition to form a layer. conductive according to the present invention on the outer surface of the panel, coating, drying and heating thereof. In the CRT according to the present invention, the protective layer includes at least one which is selected from the group consisting of a hydrolysis of metal alkoxide represented by formula (1) and one of hydrolysis of silicon alkoxide oligomer depicted by the formula (2): Formula (1): [Mx (-R) n] where M_ is one that is selected from the group consisting of Si, Ti, Sn, Zr and Ce, R can be the same or different between yes and is an alkyl of C, -C4, and m is an integer that is selected from 4 to 6; Formula (2): (SiO) n (OR) r wherein n is in the range of 0.5-1.5, R is a C_-C4 alkyl, and the average molecular weight is 400-6000. In addition, the pigment for adjusting the wavelength or the composition containing it can be added in the formation of the protective layer, in case it is not added in the formation of the conductive layer.

On the protective layer, a spray layer containing at least one that is selected from the group consisting of a metal alkoxide hydrolyte represented by the formula (1) and a silicon alkoxide oligomer hydrolyte represented by the formula (2), and a fluoroalkylsilane hydrolyte represented by the formula (3) which can be further formed on the protective layer: Formula (1): [Mx (OR) wherein Mx is one that is selected from the group that consists of Si, Ti, Sn, Zr and Ce, R may be the same or different from each other and is an alkyl of C ^ C ,, and m is an integer that is selected from 4 to 6; Formula (2): (SiO) n (OR) 4.2n wherein n is in the range of 0.5-1.5, R is an alkyl of C! -C4, and the average molecular weight is 400-6000. Formula (3): R1R2Si (R3) 3 where R? is a C2-C10 fluoroalkyl, R2 is a C0-C2 alkyl, R3 may be the same or different from each other and is a C-C5 alkyl or alkoxy, or a halogen. Optionally, the spray layer can be used. In the case where the CRT according to the present invention uses a double coating layer structure having the conductive layer and the protective layer is stacked sequentially on the outer surface of the panel, the fluoroalkylsilane can be further added to the composition for forming the protective layer to reinforce moisture tolerance, whereby the phenomenon of film separation is avoided and the film contamination resistance is improved. Figure 3 is a sectional view of the cathode ray tube (CRT) according to the present invention. With reference to Figure 3, the CRT according to the present invention includes a panel 11, a funnel 15, a deflection yoke 16 and an electron gun 17. Here, the panel 11 has a curved inner surface having a predetermined curvature and a flat outer surface on which a conductive layer 12, a protective layer 13, and a spray layer 14 are sequentially formed. A method for manufacturing the CRT according to a preferred embodiment of the present invention will now be described in detail. First, a conductive black pigment, a conductive agent and a binder in an organic solvent are dissolved to prepare a solution containing black pigment. Then, a pigment for adjusting the wavelengths, a conductive polymer and a dispersing agent selected from compounds containing sulfone groups, are mixed, dispersed using a paint shaker and then ground by ultrasonic waves, so it is prepared a pigment composition for adjusting wavelengths. The conductive black pigment composition and the pigment composition for adjusting the wavelengths are mixed and then ground by ultrasonic waves to prepare a composition to form a conductive layer. Here, the conductive black pigment and the pigment for adjusting wavelengths have an average particle diameter of 200 nm or less, preferably 120 nm or less. If the average particle diameter is greater than 200 nm, white turbidity occurs in the conductive layer, which undesirably decreases resolution. The composition prepared in this manner to form a conductive layer is spin-coated on the outer surface of the transparent ink panel for a CRT of 43-48 cm (17-19 inches), and then dried to form the conductive layer. Subsequently, at least one compound selected from the group consisting of metal alkoxide represented by the formula (1) and a silicon alkoxide oligomer represented by the formula (2) and an acid catalyst are stirred to mix the solvent, and then the resulting mixture is coated by centrifugation on the conductive layer and then dried to form a protective layer. Successively, at least one compound selected from the metal alkoxide represented by the formula (1) and silicon alkoxide oligomer represented by the formula (2) and fluoroalkylsilane represented by the formula (3) and an acid catalyst are mixed with the solvent, with stirring, and the resulting mixture is spray coated onto the protective layer and then dried to form an antireflective spray coating having irregularities. Finally, the resulting structure is heated to complete the CRT having the triple coating layer on the outer surface of the panel. In the present invention, each layer can be formed by methods conventional in the art, for example by simple coating methods such as spin coating, spray coating or deposition coating. As described above, the conductive black pigment contained in the composition to form the conductive layers improves the conductivity and decreases the transmittance, thereby improving the contrast characteristics, and the binder increases the hardness of the film and increases the resistance of the coupling force between the conductive layer and the upper and lower layers thereof. In other words, the conductive layer formed using the composition for forming the conductive layer according to the present invention has low strength, in the range of 102 ~ 1010 O / ü, preferably 10 '~ 104 O / ü, and excellent characteristics of contrast and film properties. The embodiments of the present invention will now be described in detail, but the invention is not limited thereto. The resistance, transmittance, film hardness and moisture tolerance of CRT obtained in the examples and in the comparative example are evaluated as follows, "and" the results are shown in Table 1.

Resistance The surface resistance of a sample is measured at four points using a surface resistance measuring machine and the average value of the four measured resistance values is calculated.

Transmittance The transmittance is measured at 550 nm using a spectroscope for visible ray bands.

Contrast The contrast is measured using a 400 Lux light source.

Tolerance to Moisture A panel without a coating layer is prepared as a control sample on its outer surface, and samples are impregnated for the examples and the comparative example as well as the control sample, in water at 60 ° C for 8 hours. Then, the film states and the changes in the resistance before and after the formation of the coating layer are observed, and the results are shown as follows: T: very good O: good ?: scanty x: poor < Example 1 > g of a carbon black dispersion solution (carbon black content: 0.5 g) obtained by dispersing carbon black having an average particle diameter of 200 nm in water, 10 g of polythiophene and 2 g of tetraethoxysilane dissolved in a solvent mixture composed of 35 g of methanol, 20 g of ethanol, 15 g of isopropyl alcohol and 20 g of methyl cellosolve, to prepare a composition containing carbon black. Subsequently, a pigment composition is mixed to adjust the wavelength consisting of 10 g of a 1.5% blue pigment dispersion solution and 5 g of 2.0% violet pigment dispersion solution with the composition "containing carbon black and then subjected to grinding by ultrasonic waves for 4 hours to prepare a composition to form a conductive layer, subsequently, the prepared composition is applied as a spin coating on the outer surface of a transparent ink panel for a CRT of 48 cm (19 inches) that has approximately 81% in the average transmittance between the central and peripheral portions of the CRT, and dries to form the conductive layer. Then, 3 g of tetraethoxysilane and a mixture solvent consisting of 30 g of methanol, 50 g of ethanol, 12 g of normal butanol and 4 g of water are added, 0.5 g of nitric acid are added and reacted at room temperature. environment for 24 hours to prepare a composition to form a protective layer. Later, the prepared composition is applied as a coating by centrifugation on the conductive layer and dried to form the protective layer. Subsequently, 3 g of tetraethoxysilane and 0.3 g of 0.3 g of CF3 (CFJ 7CH_CH Si (OCH 3) 3 are mixed with a mixing solvent consisting of 30 g of methanol, 50 g of ethanol, 12 g of normal butanol and 4 g of water, and 0.5 g of nitric acid are added thereto and reacted at room temperature for 24 hours to prepare a composition to form a spray layer, then the prepared composition is applied as a spray coating on the protective layer and Dry to form the spray layer Finally, the result is thermally treated at 200 ° C for 30 minutes, so that the CRT is completed, and the resistance, transmittance, contrast and humidity tolerance of the same of the following Table are measured. 1. < Example 2 > With the exception of the spray layer that is not formed on the protective layer, this embodiment is carried out in the same manner as that described in example 1. < Example 3 > With the exception of 0.3 g of CF \, (CF -, CH_CH_Si (OCH < which is added later when preparing the composition to form a protective layer and a spray layer that is not formed, this embodiment is carried out from the same way as described in example 2, to complete a CRT. < Example 4 > With the exception of a pigment composition for wavelength adjustment consisting of 23.7 g of 1.5% blue pigment dispersant solution and 7.9 g of 2.0% violet pigment dispersion solution which is subsequently added to prepare the composition to form a layer protective, instead of preparing the composition of a conductive layer, this embodiment is carried out in the same way to that described in example 1, to complete a CRT. < Example 5 > With the exception of the composition to form a conductive layer that is prepared using 3 g of indium tin oxide (ITO) having an average particle diameter of 200 nm instead of polythiophene, this embodiment is carried out therefrom as described in example 1, to complete a CRT. < Example 6 > With the exception of a composition "to form a conductive layer that is prepared using 0.3 g of silver (Ag) having an average particle diameter of 120 nm instead of polythiophene, this embodiment is carried out in the same way to the described in example 1, to complete a CRT. < Comparative Example > With the exception of tetraethoxysilane that is not added when preparing a composition to form a conductive layer and a spray layer that is not formed, this embodiment is carried out in the same manner as described in example 1, to complete a CRT .

Table 1 It is understood from Table 1 that the CRT according to the present invention has excellent conductivity and contrast characteristics, and also improves the humidity tolerance thereof. In Example 2, since the spray layer contains a fluoroalkylsilane hydrolyte, which is a water repellent component, it is not formed, the moisture tolerance decreases a little. However, due to the silicon alkoxide oligomer added to the conductive layer as a binder, moisture tolerance is still maintained at a predetermined level.

Although the transmittance is low and the contrast characteristics are excellent, in the comparative example, the resistance is high and the tolerance to humidity is poor. Therefore, the stability of the film is considered damaged. The conductive layer using the composition according to the present invention shows excellent transmittance and contrast characteristics. In addition, the conductive layer has excellent moisture tolerance, which improves the stability of the film and provides a clean color purity and a high quality body color. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects or products to which it refers.

Claims (15)

CLAIMS Having described the invention as above, the content of the following claims is claimed as property.

1. A composition for forming a conductive layer comprising 0.01-1.0% by weight of a conductive black pigment, 0.05-10% by weight of a binder, 0.01-50% by weight of a conductive agent and the remaining amount of a solvent based on in the total weight of the composition.

2. The composition according to claim 1, characterized in that the conductive black pigment is at least one which is selected from the group consisting of carbon black and titanium black, and the average particle diameter thereof is 200. nm or less.

3. The composition according to claim 1, characterized in that the binder is at least one which is selected from the group consisting of a silane coupling agent, a metal alkoxide represented by the formula (1) and a silicon alkoxide oligomer. represented by the formula (2): Formula (1) [Mx (0R) m] wherein M: is one that is selected from the group consisting of Si, Ti, Sn, Zr and Ce, R may be the same or different from yes and is an alkyl of C, -C4, and m is an integer selected from 4 to 6; Formula (2) (SiO) n (OR) 4_2r. wherein n is in the range of 0.5-1.5, R is an alkyl of C_-C ", and the average molecular weight is 400-6000.

4. The composition according to claim 1, characterized in that the conductive agent is at least one which is selected from the group consisting of metal, metal oxide or a conductive polymer. The composition according to claim 4, characterized in that the conductive polymer is at least one which is selected from the group consisting of polythiophene, polyaniline, polypyrrole, polyacetylene, polyfuran, polyparaphenylene, and polyselenophen. 6. The composition according to claim 1, characterized in that it further comprises at least one wavelength-adjusting pigment having a maximum transmittance in the wavelength range of 400-700 nm and the average particle diameter of the same is 200 nm or less. The composition according to claim 6, characterized in that the wavelength-adjusting pigment is added in the form of a pigment composition containing a pigment for adjusting wavelengths, a dispersing agent and a conductive polymer, and Pigment composition is prepared by dissolving 0.3-30% by weight of a wavelength adjusting pigment and 0.24-1.2% by weight of a dispersing agent in an organic mixture solvent containing 5-50% by weight of a polymer conductor, mechanically disperse and then grind by ultrasonic waves the same. 8. The composition according to claim 7, characterized in that the conductive polymer is at least one that is selected from the group consisting of polythiophene, polyaniline, polypyrrole, polyacetylene, polyfuran, polyparaphenylene and polyselenophen. 9. A cathode ray tube, characterized in that it comprises: a panel; and a conductive layer and a protective layer sequentially formed on the outer surface "of the panel, wherein the conductive layer is prepared by coating the composition to form a conductive layer according to any of claims 1 to 9 on the outer surface of the panel , coating, drying and heating the same 10. The cathode ray tube according to claim 8, characterized in that the protective layer includes at least one which is selected from the group consisting of a hydrolysis of metal alkoxide represented by the formula (1) and a hydrolysis of silicon alkoxide oligomer represented by the formula (2): Formula (1) [Mi (OR) -,] wherein _ is one which is selected from the group consisting of Si, Ti, Sn, Zr and Ce, R may be the same or different from each other and is a C: -C4 alkyl, and m is an integer selected from 4 to 6; Formula (2) (SiO) r (0R) _, n wherein n is in the range of 0.5-1.5, R is an alkyl of C-C-, and the average molecular weight is 400-6000. - -? The cathode ray tube according to claim 8, characterized in that the protective layer further includes a hydrolysis of -fluoroalkylsilane represented by the formula (3): Formula (3) RiRSi (R 3 where R_ is a fluoroalkyl of C ^ -C10, R ^ is a C0-C2 alkyl, R, can be the same or different from each other, and is a Cx-C alkyl or alkoxy, or a halogen. according to claim 10 or 11, characterized in that the protective layer further includes at least one wavelength-adjusting pigment having a maximum transmittance in the wavelength range of 400-700 nm and the average particle diameter of the The same is 200 nm or less 13. The cathode ray tube according to claim 12, characterized in that the wavelength adjustment pigment is added in the form of a pigment composition containing a pigment for adjusting wavelengths. , an agent d ispersant and a conductive polymer, and the pigment composition is prepared by dissolving 0.3-30% by weight of a wavelength-adjusting pigment and 0.24-1.2% by weight of a dispersing agent in an organic-mixture solvent containing -50% by weight of a conductive polymer, mechanically dispersing and then grinding by means of ultrasonic waves the same. The cathode ray tube according to claim 13, characterized in that the conductive polymer is at least one which is selected from the group consisting of polythiophene, polyaniline, polypyrrole, polyacetylene, polyfuran, polyparaphenylene and polyselenophene. 1

5. The cathode ray tube according to claim 9, characterized in that it further comprises a spray layer containing at least one hydrolyte selected from the group consisting of a metal alkoxide hydrolyte represented by the formula (1) and a silicon alkoxide oligomer hydrolyte represented by the formula (2), and a fluoroalkylsilane hydrolyte represented by the formula (3) can be further formed on the protective layer: Formula (1) [M. (OR),.] Where M is one that is selected from the group consisting of Si, Ti, Sn, Zr and Ce, R may be the same or different from each other_ and is an alkyl of C ^ -C4, and m is a whole number that is selected from 4 to 6; Formula (2) (SiO) r, (OR), n wherein n is in the range of 0.5-1.5, R is an alkyl of C ^ ^ and the average molecular weight is 400-6000. Formula (3) R? R, Si (RJ, where R_ is a fluoroalkyl of C, -C_, R is an alkyl of Cc-C ,, R. may be the same or different from each other, and is a C-alkyl. : -C5 or alkoxy, or a halogen. EXTRACT OF THE INVENTION A composition is provided to form a conductive layer comprising 0.01-0.1% by weight of a conductive black pigment, 0.05-10% by weight of a binder, 0.01-50% by weight of a conductive agent, and the remaining amount of a solvent based on the total weight of the composition, and a cathode ray tube (CRT) having the conductive layer formed by coating the composition on the outer surface of a panel, drying and heating thereof, and a formed protective layer on the conductive layer. The conductive layer formed using the composition has excellent conductivity, contrast characteristics and film properties. In addition, a clean purity of color and a high quality body color can be obtained.