KR100284335B1 - Composition for forming conductive film and cathode ray tube employing conductive film formed by using the same - Google Patents

Abstract

The present invention includes conductive black pigment fine particles, conductive polymers, binders, pigment fine particles for controlling wavelengths and solvents, wherein the conductive black pigment fine particles, conductive polymers, binders and pigment fine particles for adjusting wavelengths are each 0.01 to 1.0 based on the total weight of solids in the composition. The present invention relates to a composition for forming a conductive film having a weight%, 0.03 to 0.5 weight%, 0.1 to 10 weight%, and 0.01 to 0.2 weight%, and a cathode ray tube with a conductive film formed using the same. By using the composition according to the present invention, it is possible to obtain a conductive film having excellent film properties, excellent conductivity and controllability thereof. In addition, the cathode ray tube employing such a conductive film has improved transmittance as the transmittance is reduced to a level of up to 30%, and can exhibit excellent color purity and high quality body color.

Description

Composition for forming conductive film and cathode ray tube employing conductive film formed by using the same}

The present invention relates to a conductive film, and more particularly, to a composition for forming a conductive film having excellent conductivity and improved contrast characteristics, resolution, and film strength, and a cathode ray tube with a conductive film formed using the same.

Until now, curved panels having a predetermined curvature have been mainly used for cathode ray tubes due to manufacturing process problems. However, such curved panels have a problem that glare and distortion of images become more severe toward the outside of the panel, so that high quality images cannot be realized. There is a limit.

To compensate for this drawback is a panel having a curvature near infinity, that is, a flat panel.

As the curvature of the panel is larger, that is, the panel is closer to the plane, glare caused by external light reflection is suppressed, so that a clear image can be realized, eye fatigue can be reduced, and image distortion does not occur. Therefore, the research on the cathode ray tube employing a flat panel has recently been conducted at various angles.

Proposed as an example of a flat panel is a panel in which both the inner and outer surfaces of the panel are completely flat as shown in FIG. 1A. However, in the case of a cathode ray tube employing such a panel, an image implemented in the center portion of the panel appears to enter the inner surface.

In order to overcome this problem, as shown in FIG. 1B, a flat panel having a curvature structure having an outer surface of the panel and a predetermined curvature is proposed.

However, the flat panel having such a structure has a problem in that transmittance is different due to the difference in thickness between the center portion and the peripheral portion of the panel. In addition, when the dark tint or semi tint panel having a transmittance of about 40% to 50% is generally applied to a flat panel having the above structure, the difference in transmittance between the center and the peripheral part becomes larger, making it difficult to realize a uniform image. .

Accordingly, a method of preventing contrast decrease due to high transmittance has been proposed by using a clear tint panel having a transmittance of 80% or more and coating a conductive film for controlling transmittance on its outer surface.

Such conductive film should maximize external light absorption to improve contrast, minimize transmitted light scattering to suppress image bleeding, and have conductivity to prevent dust adhesion by static electricity. In addition, the film strength should be excellent.

As an example of such a composition for forming a conductive film, a cathode ray tube having a conductive coating composition comprising a dye or pigment, conductive fine particles for supplementing the conductivity of the dye or pigment, and a binder such as silicate and a formed conductive film using the same has been proposed. .

However, such a conventional conductive coating composition has a high content of pigments and conductive fine particles as compared to the content of the binder, so that the mechanical strength of the conductive film formed therefrom is low and the transmittance reduction is only about 30%, so that sufficient contrast improvement effect cannot be obtained. There is this.

The technical problem to be achieved by the present invention is to provide a composition for forming a conductive film having excellent conductivity and improved contrast characteristics, resolution and mechanical strength.

Another technical problem to be achieved by the present invention is to provide a cathode ray tube manufactured from the composition and having a conductive film having excellent conductivity and excellent contrast characteristics, resolution, and mechanical strength.

1A is a cross-sectional view of a conventional flat panel.

1B is a cross-sectional view of a flat panel according to the present invention.

2 is a cross-sectional view of a cathode ray tube with a conductive film according to an embodiment of the present invention.

<Explanation of symbols for main parts of the drawings>

11 ... Panel 12 ... Conductive Film

13 ... shield 14 ... spray

15 ... Funnel 16 ... Deflection yoke

17 ... electron gun

The technical problem of the present invention includes conductive black pigment fine particles, conductive polymers, binders, pigment fine particles for controlling wavelengths and solvents, wherein the conductive black pigment fine particles, conductive polymers, binders and pigment fine particles for wavelength control are based on the total weight of solids in the composition, respectively. 0.01 to 1.0% by weight, 0.03 to 0.5% by weight, 0.1 to 10% by weight and 0.01 to 0.2% by weight of the composition for forming a conductive film can be made.

According to another aspect of the present invention, in a cathode ray tube including a panel and a conductive film and a protective film sequentially formed on an outer surface of the panel, the conductive film may include conductive black pigment fine particles, conductive polymers, a binder, and pigment fine particles for wavelength control. It can be made by a cathode ray tube characterized in that it comprises 0.01 to 1.0% by weight, 0.03 to 0.5% by weight, 0.1 to 10% by weight and 0.01 to 0.2% by weight, respectively.

In the composition for forming a conductive film according to the present invention and the conductive film formed using the same, the conductive black pigment fine particles are at least one selected from carbon black, titanium black (TiO ₂ ) and silver (Ag), preferably carbon black. And the average particle diameter is 200 nm or less, Preferably it is 120 nm or less.

Further, the conductive polymer is not particularly limited as long as it is conductive and has a volume resistivity of the polymer itself of 10 ⁵ 자체 cm or less, and is generally used in the field of the present invention. Polyacetylene, polyfuran, polyparaphenylene, polyserenophene, etc. are mentioned, A polythiophene type polymer is preferable.

In addition, the binder is preferably at least one selected from a silane coupling agent such as epoxysilane, trimethoxysilane or vinylsilane, a metal alkoxide of formula (1) and a silicon alkoxide oligomer of formula (2).

[M ₁ (OR) ₄ ]

Wherein M ₁ is Si, Ti, Sn or Zr, and R is an alkyl group having 1 to 4 carbon atoms.

(SiO) _n (OR) _4-2n

In said formula, n is 0-1 and R is a C1-C4 alkyl group.

On the other hand, the pigment fine particles for wavelength control are organic or inorganic pigments or dyes that can be commonly used in the field of the present invention, preferably organic or inorganic pigments that can correct the color of the black pigment by excellent transmittance in the 400 ~ 700nm region Or dyes, more preferably one or more pigments selected from phthalocyanine pigments and purple pigments, the average particle diameter of which is 200 nm or less, more preferably 120 nm or less.

In addition, as a solvent, alcohol solvents, such as methanol, ethanol, isopropyl alcohol, n-butanol, N-methyl 2-pyrrolidone (NMP), dimethylformamide, water, etc. can be used individually or in mixture.

The composition for forming a conductive film according to the present invention may be formed of silver (Ag), gold (Au), platinum (Pt), copper (Cu), nickel (Ni), palladium (Pd), cobalt (Co), and rhodium as necessary. (1) selected from metal fine particles such as (Rh), ruthenium (Ru) or tin (Sn), and metal oxide fine particles such as tin oxide, indium oxide, indium tin oxide (ITO), antimony oxide, antimony zinc oxide or antimony tin oxide, and the like. It may further contain more than one type of conductive fine particles, in which case the average particle diameter of these fine particles should be 200 nm or less, preferably 120 nm or less.

On the other hand, in the cathode ray tube according to the present invention, the protective film may include at least one selected from hydrolyzates of metal alkoxides of formula (1) and hydrolyzates of silicon alkoxide oligomers of formula (2). It may further comprise a hydrolyzate of alkylsilane.

In addition, in the cathode ray tube according to the present invention, at least one hydrolyzate selected from the hydrolyzate of the metal alkoxide of the formula (1) and the hydrolyzate of the silicon alkoxide oligomer of the formula (2) above, and the valence of the fluoroalkylsilane It may further include a spray film including a decomposition product.

[Formula 1]

[M ₁ (OR) ₄ ]

Wherein M ₁ is Si, Ti, Sn or Zr, and R is an alkyl group having 1 to 4 carbon atoms.

[Formula 2]

(SiO) _n (OR) _4-2n

In said formula, n is 0-1 and R is a C1-C4 alkyl group.

In the present invention, specific examples of the fluoroalkylsilane may be CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ Si (OCH ₃ ) ₃ , CF ₃ (CF ₂ ) ₅ CH ₂ CH ₂ Si (OCH ₃ ) ₃ , CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ SiCH ₃ (OCH ₃ ) ₂ , CF ₃ CH ₂ CH ₂ Si (CH ₃ ) ₃ , CF ₃ (CF ₂ ) ₅ CH ₂ CH ₂ SiCl ₃ , CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ SiCl ₃ , CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ SiMeCl ₃ or CF ₃ CH ₂ CH ₂ SiCl ₃ .

Whereas the conventional composition for forming a conductive film includes a pigment and conductive fine particles separately, and thus the content of the binder is relatively small, the composition for forming a conductive film according to the present invention is characterized by adding conductive black pigment fine particles having excellent external light absorption ability. Instead, by increasing the content of the binder and adding a conductive polymer as a dispersant and a conductive agent to improve the conductivity and film strength, and by adding organic or inorganic pigments or dyes as pigment fine particles for wavelength control, high contrast quality and color purity It is characterized by providing body color.

2 is a cross-sectional view of a cathode ray tube according to an example of the present invention.

Referring to the drawings, the cathode ray tube according to the present invention includes a panel 11, a funnel 15, a deflection yoke 16 and an electron gun 17, of which the panel 11 has a predetermined inner surface. The curvature is curved and the outer surface is a planar structure, and the conductive film 12, the protective film 13, and the spray film 14 are sequentially formed on the outer surface thereof.

The manufacturing method of the cathode ray tube which concerns on this invention is demonstrated concretely.

First, the conductive black pigment fine particles, the conductive polymer, the binder, and the fine particles for wavelength control are mixed with a solvent under stirring to prepare a composition for forming a conductive film. In this case, the conductive black pigment fine particles and the wavelength control pigment fine particles are used having an average particle diameter of 200nm or less, preferably 120nm or less, when the average particle diameter exceeds 200nm whitening occurs in the conductive film formed from this composition and the resolution is reduced There is a problem that it is not preferable. In addition, if necessary, conductive fine particles commonly used in the field of the present invention may be further added to the composition. In this case, the average particle size range should be the same as above.

The conductive film forming composition thus prepared is spin coated on the outer surface of a clear tint panel for a 19 inch cathode ray tube having an average transmittance of about 81% at the center and periphery of the panel, and then dried to form a conductive film.

Subsequently, at least one compound selected from the metal alkoxide of Formula 1 and the silicon alkoxide oligomer of Formula 2 and an acid catalyst are mixed with a solvent under stirring, and the mixture is spin-coated on the conductive layer and then dried to form a protective film. .

Subsequently, at least one compound selected from the metal alkoxide of formula (1) and the silicon alkoxide oligomer of formula (2) and fluoroalkylsilane are mixed with the solvent under stirring with an acid catalyst and the mixture is spray coated onto the protective film, It is dried to form an antireflection spray film having an uneven structure.

Finally, the resultant was fired to complete a cathode ray tube having three coating layers formed on an outer surface of the panel.

According to the present invention, according to the content of the conductive black pigment fine particles and the conductive polymer in the composition for forming a conductive film, the resistance of the conductive film may be adjusted in the range of 10 ² to ^{10 10} Pa / □, and the transmittance may be adjusted in the range of 30 to 95%. In addition, the binder added in a large amount compared to the conventional conductive film forming composition provides a more dense network of the conductive film itself to provide a film forming property, as well as the conductive film and its upper and lower films (ie, the lower panel and the upper part). The film strength is improved by strengthening the bonding force between the protective films to be formed).

In addition, the fluoroalkylsilane in the composition for forming a spray film can prevent the film separation phenomenon due to moisture absorption by making the film have moisture resistance.

On the other hand, the silicon alkoxide oligomer of the general formula (2) used in the present invention preferably has an average molecular weight of 400 to 6,000, if less than 400 has a disadvantage that the film strength is lowered, while the viscosity exceeds 6,000.

In the present invention, each film may be formed by a method which may be conventionally used in the field of the present invention, that is, by an easy coating method such as, for example, spin coating, spray coating or dip coating.

In the present invention, the cathode ray tube may have a two-layer coating film structure in which only the conductive film and the protective film are sequentially formed on the outer surface of the panel. In this case, the moisture resistance can be reinforced by further adding fluoroalkylsilane to the protective film-forming composition.

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

The resistance, transmittance, film strength, and moisture resistance of the cathode ray tubes obtained in Examples and Comparative Examples were evaluated as follows, and the results are shown in Table 1 below.

resistance measurement

The surface resistance of 4 points of a sample was measured using the surface resistance meter, and the average value was computed.

Transmittance measurement

The transmittance at 550 nm was measured using a spectrophotometer in the visible light band.

Evaluation of moisture resistance

A panel having no coating film formed on the outer surface of the panel was prepared as a control sample, and the control sample and the samples of Examples and Comparative Examples were immersed in water at 60 ° C. for 8 hours, and before and after the film formation. The resistance change was observed and evaluated, and the evaluation result was expressed as follows:

◎ very good

○: good

△: normal

×: defective

<Example 1>

10 g of carbon black dispersion obtained by dispersing carbon black having an average particle diameter of 200 nm in water (carbon black content: 0.5 g), 10 g of polythiophene and 2 g of tetraethoxysilane in 35 g of methanol, 20 g of ethanol, 15 g of iso Dissolved in a mixed solvent consisting of propyl alcohol and 20 g of methyl cellosolve to prepare a composition for forming a conductive film, and then spin coating on the outer surface of a clear tint panel for 19-inch cathode ray tubes having an average transmittance of about 81% at the center and the periphery. And dried to form a conductive film.

Next, 3 g of tetraethoxysilane was mixed with a mixed 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 was added thereto to react at room temperature for 24 hours to form a protective film. After the composition was prepared, spin coating and drying were performed on the conductive film to form a protective film.

Then, a mixed solvent consisting of ₃ g of tetraethoxysilane and 0.3 g of CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ Si (OCH ₃ ) ₃ consists of 30 g of methanol, 50 g of ethanol, 12 g of normal butanol and 4 g of water. And a 0.5 g nitric acid was added thereto to react at room temperature for 24 hours to prepare a composition for forming a spray film, and then spray-coated and dried on the protective film to form a spray film.

Finally, the cathode ray tube was completed by heat treatment at 200 ° C. for 30 minutes.

<Example 2>

A cathode ray tube was completed in the same manner as in Example 1 except that no spray film was prepared on the protective film.

<Example 3>

A cathode ray tube was completed in the same manner as in Example 1, except that 3 g of indium tin oxide having an average particle diameter of 200 nm was used instead of PEDT to prepare a composition for forming a conductive film.

<Example 4>

A cathode ray tube was completed in the same manner as in Example 1 except that 0.3 g of silver having an average particle diameter of 200 nm instead of PEDT was used to prepare a composition for forming a conductive film.

<Comparative Example 1>

A cathode ray tube was completed in the same manner as in Example 2 except that tetraethoxysilane was not added at the time of preparing the composition for forming a conductive film.

Resistance (Ω / □) Transmittance (%) Moisture resistance Remarks Example 1 8 × 10 ³ 60 ◎ No resistance change Example 2 3 × 10 ⁴ 61 ○ Slight increase in resistance Example 3 6 × 10 ⁴ 65 ◎ No resistance change Example 4 8 × 10 ² 50 ◎ No resistance change Comparative Example 1 5 × 10 ⁸ 56 × Membrane Separation Occurs

From the results of Table 1, it can be seen that the cathode ray tubes (Examples 1 to 4) according to the present invention are not only excellent in conductivity and moisture resistance, but also have improved contrast.

However, in Example 2, although the spray film containing the hydrolyzate of the fluoroalkylsilane, which is a water repellent component, was not formed, the moisture resistance was slightly decreased, but the predetermined moisture resistance was prevented by the silicon alkoxide oligomer added as a binder to the conductive film. It can be seen that.

However, when the conductive film does not contain a binder and the outermost layer does not contain a hydrolyzate of fluoroalkylsilane as a water repellent component (Comparative Example 1), the moisture resistance is poor and a film separation phenomenon occurs. It can be seen that this is greatly inhibited.

The conductive film prepared using the composition according to the present invention has a reduced transmittance up to a level of 30% and is excellent in film formability. Therefore, the cathode ray tube containing such a conductive film is excellent in electroconductivity, contrast characteristics, and film strength.

Claims (13)

Conductive black pigment fine particles, conductive polymer, binder, wavelength control pigment fine particles and a solvent, The conductive black pigment fine particles, the conductive polymer, the binder, and the wavelength control pigment fine particles are 0.01 to 1.0% by weight, 0.03 to 0.5% by weight, 0.1 to 10% by weight and 0.01 to 0.2% by weight, respectively, based on the total weight of solids in the composition. Formation composition. 2. The conductive film-forming composition according to claim 1, wherein the conductive black pigment fine particles are at least one selected from carbon black, titanium black, and silver oxide, and have an average particle diameter of 200 nm or less. The conductive film-forming composition according to claim 1, wherein the conductive polymer is at least one selected from polythiophene, polyaniline, polypyrrole, polyacetylene, polyfuran, polyparaphenylene, and polyserenophene. The conductive film-forming composition according to claim 1, wherein the binder is at least one selected from a silane coupling agent, a metal alkoxide of formula (1), and a silicon alkoxide oligomer of formula (2). [Formula 1] [M ₁ (OR) ₄ ] Wherein M ₁ is Si, Ti, Sn or Zr, and R is an alkyl group having 1 to 4 carbon atoms. [Formula 2] (SiO) _n (OR) _4-2n In said formula, n is 0-1 and R is a C1-C4 alkyl group. The conductive film-forming composition according to claim 1, wherein the pigment fine particles for wavelength adjustment are at least one selected from organic or inorganic pigments and dyes having a maximum transmittance of 400 to 700 nm and an average particle diameter of 200 nm or less. panel; And In the cathode ray tube comprising a conductive film and a protective film sequentially formed on the outer surface of the panel, The conductive film comprises conductive black pigment fine particles, conductive polymers, binders and pigment fine particles for wavelength adjustment, 0.01 to 1.0% by weight, 0.03 to 0.5% by weight, 0.1 to 10% by weight and 0.01 to 0.2% by weight, respectively. Cathode ray tube. The cathode ray tube according to claim 6, wherein the conductive black pigment fine particles are at least one selected from carbon black, titanium black, and silver oxide, and have an average particle diameter of 200 nm or less. The cathode ray tube according to claim 6, wherein the conductive polymer is at least one selected from polythiophene, polyaniline, polypyrrole, polyacetylene, polyfuran, polyparaphenylene, and polyserenophene. The cathode ray tube according to claim 6, wherein the binder is at least one selected from a silane coupling agent, a metal alkoxide of formula (1), and a silicon alkoxide oligomer of formula (2). [Formula 1] [M ₁ (OR) ₄ ] Wherein M ₁ is Si, Ti, Sn or Zr, and R is an alkyl group having 1 to 4 carbon atoms. [Formula 2] (SiO) _n (OR) _4-2n In said formula, n is 0-1 and R is a C1-C4 alkyl group. The cathode ray tube according to claim 6, wherein the pigment fine particles for wavelength adjustment are at least one selected from organic or inorganic pigments and dyes having a maximum transmittance of 400 to 700 nm and an average particle diameter of 200 nm or less. The cathode ray tube according to claim 6, wherein the protective film comprises at least one selected from a hydrolyzate of a metal alkoxide of formula (1) and a hydrolyzate of silicon alkoxide oligomer of formula (2). [Formula 1] [M ₁ (OR) ₄ ] Wherein M ₁ is Si, Ti, Sn or Zr, and R is an alkyl group having 1 to 4 carbon atoms. [Formula 2] (SiO) _n (OR) _4-2n In said formula, n is 0-1 and R is a C1-C4 alkyl group. 12. The cathode ray tube according to claim 11, wherein the protective film further comprises a hydrolyzate of fluoroalkylsilane. The spray of claim 6, wherein the protective layer includes a hydrolyzate of a metal alkoxide of Formula 1 and at least one hydrolyzate of a silicon alkoxide oligomer of Formula 2, and a hydrolyzate of fluoroalkylsilane. Cathode ray tube further comprises a membrane. [Formula 1] [M ₁ (OR) ₄ ] Wherein M ₁ is Si, Ti, Sn or Zr, and R is an alkyl group having 1 to 4 carbon atoms. [Formula 2] (SiO) _n (OR) _4-2n In said formula, n is 0-1 and R is a C1-C4 alkyl group.