KR20030021985A - A composition for a conductive layer and a conductive layer therefrom - Google Patents

Abstract

PURPOSE: A composition for formation of a conductive film and a conductive film produced from the same are provided to reduce manufacturing costs by using metallic oxide fine particles rather than metallic colloid, while improving mechanical strength and contrast. CONSTITUTION: A composition contains metallic oxide fine particles, a coloring agent, and a silane coupling agent. The metallic oxide fine particles are 0.5 to 6 percent calculated in terms of a solid, the coloring agent is 0.01 to 10 percent calculated in terms of a solid, and the silane coupling agent is 0.01 to 10 percent calculated in terms of a solid. The metallic oxide fine particles are selected from a group consisting of indium tin oxide, antimony tin oxide, aluminum zinc oxide, SnO2, In2O3 and Sb2O3. The coloring agent is selected from a group consisting of organic or inorganic pigment and metal complex.

Description

A composition for forming a conductive film and a conductive film produced therefrom {A COMPOSITION FOR A CONDUCTIVE LAYER AND A CONDUCTIVE LAYER THEREFROM}

[Industrial use]

The present invention relates to a composition for forming a conductive film and a conductive film prepared therefrom, and more particularly, transmittance and body color can be controlled, mechanical strength and contrast can be improved, and antistatic and electromagnetic shielding properties. The excellent conductive film formation composition and the transparent conductive film manufactured from this composition are related.

[Prior art]

Cathode Ray Tube (CRT) panels are coated with a multifunction film depending on the type of panel. Examples thereof include a high contrast film for reducing the transmittance, an antireflection film for reducing the reflectance, an antistatic film for preventing adhesion of static electricity and dust, and the like. Recently, with increasing interest in the effects of electromagnetic waves on the human body and stricter regulations on electromagnetic waves, development of membranes capable of shielding electromagnetic fields formed from electromagnetic waves and electromagnetic waves has been actively conducted. The material and structure of the films are determined according to the conductivity, transmittance and reflectance required for the panel.

A transparent conductive film is formed on the panel surface using a coating liquid containing conductive fine particles for the purpose of antistatic, antireflection and electromagnetic shielding of the display device. The transparent conductive film is a thin conductive film formed on a glass substrate or a plastic substrate having a high light transmittance.

In general, the transparent conductive film is a spin coating, spray coating or dipping coating composition comprising a transparent conductive particles, such as metal oxides such as tin oxide doped with antimony (Sb) or indium oxide doped with tin (Sn), etc. It is formed by coating using the same wet coating method followed by low temperature baking.

However, the transparent conductive film formed by this method has a surface resistance of about 10 ⁷ kW / ?, which is larger than 10 ² kW /? 10 ⁴ kW / ?. In addition, in order to lower the surface resistance, the thickness of the conductive film must be increased, but as the thickness of the conductive film is increased, the anti-reflective effect is reduced. Therefore, a low surface resistance, good electron shielding and It is difficult to form a transparent conductive film having an antireflection effect. In particular, in the case of flat panel monitors, high-voltage and transparent panels are applied, a highly conductive low-transmittance film must be formed as a transparent conductive film to cope with electromagnetic regulations of the Swedish Confederation for Professional Employees (TCO).

In order to solve this drawback, a method of forming a conductive thin film by applying a metal colloid obtained by dispersing metal fine particles such as Au, Ag, Pd, Ru, Rh and Pt in a solvent alone or in an alloy state to a substrate is used. (Korean Patent Publication No. 2000-50674). Korean Patent Laid-Open Publication No. 1999-11487 discloses an antistatic film having a single film structure prepared using a composition comprising metal fine particles, a binder, and a solvent. In this method, the surface of the metal fine particles was treated with a binder such as polyvinyl alcohol, polyvinyl pyrrolidone and silicon alkoxide oligomer to improve the dispersibility of the metal fine particles.

However, the method of using the metal colloid has a limit in reducing the production cost since the cost of the metal used as the conductive oxide fine particles is expensive. In addition, due to the metal colloid property, film formation and stability may be poor, and stains and foreign substances may be generated on the coating layer. In spite of the above-described problems, a metal colloid is applied to satisfy the TCO electromagnetic wave standard of the flat panel monitor.

The present invention is to solve the above problems, an object of the present invention is to provide a composition for forming a conductive film capable of controlling transmittance, high conductivity and contrast, antistatic and electromagnetic shielding.

Another object of the present invention is to provide a conductive film capable of controlling transmittance, having high conductivity and high contrast, antistatic and electromagnetic shielding prepared from the composition.

In order to achieve the above object, in the present invention, metal oxide fine particles; coloring agent; And it provides a composition for forming a conductive film comprising a silane coupling agent.

The present invention also provides a transparent conductive film prepared from the composition for forming a conductive film.

The present invention also comprises a conductive film prepared from the composition for forming a conductive film; And an anti-reflective film (protective film) formed by coating a composition including a metal alkoxide or an oligomer thereof on the conductive film.

The present invention also comprises a conductive film prepared from the composition for forming a conductive film; An antireflection film formed by applying a composition including a metal alkoxide or an oligomer thereof on the conductive film; And a non-glare layer formed by spray coating a hydrolyzate including a metal alkoxide or an oligomer thereof formed on the anti-reflection film.

Hereinafter, the present invention will be described in more detail.

The composition for forming a conductive film according to the present invention includes metal oxide fine particles; coloring agent; And a silane coupling agent.

The metal oxide fine particles include at least one oxide selected from indium tin oxide (ITO), antimony tin oxide (ATO), aluminum zinc oxide (AZO), SnO ₂ , In ₂ O _3, and Sb ₂ O ₃ . The conductive metal oxide has advantages of excellent film formation, easy processability, and low cost. The conductive oxide fine particles are preferably contained in the composition for forming a conductive film at 0.5 to 6% on a solids basis. When the amount of the conductive oxide fine particles is less than 0.5%, there is a problem that the conductivity is insufficient and when the amount of the fine particles exceeds 6%, the film forming property is poor, the reflectance is high, and the manufacturing cost is increased.

As the colorant, an organic or inorganic pigment, a metal complex, or the like may be used. The organic pigments include carbon-based materials such as carbon black or graphite, yellow, blue or violet pigments, and inorganic pigments include TiO, TiN, TiO _1-x N _x (0 <x <1), TiC, TiN. -TiC, cobalt oxide, zinc oxide, iron oxide, ruthenium oxide, aluminum oxide or mixtures of two or more thereof can be used. The metal complex includes metal complex azo dyes, metal complex anthraquinone dyes, and the like. Of these, it is preferable to use organic pigments having high color purity.

The colorant facilitates control of the transmittance and body color (color) of the conductive film. The colorant may be adjusted in amount depending on the transmittance of the conductive film. In this invention, it is preferable that solid content of the coloring agent added to the composition contains 0.01 to 10% of a coloring agent. If the content of the colorant is less than 0.01% based on the solid content, there is a problem that the color is not developed, and when the content of the colorant exceeds 10%, the transmittance is lowered and the resolution becomes worse.

The silane coupling agent is represented by the following formula (1).

[Formula 1]

YRSiX ₃

Wherein Y is one organic functional group selected from the group consisting of a vinyl group, a phenyl group, an epoxy group, an amino group, and a mercapto group having affinity (or reactivity) with an organic material, and R is an alkyl group, preferably having 1 carbon X is an alkyl group of 4 to 4, X is an alkoxy group having 1 to 4 carbon atoms, preferably a methoxy group or an ethoxy group having affinity (or reactivity) to the inorganic material.) Preferred examples of the silane coupling agent having the general formula (1) Epoxy silane, trimethoxy silane, phenyltrimethoxy silane, vinyl silane and the like.

Organic or inorganic pigments used as colorants have low affinity with conductive oxide fine particles, making it difficult to obtain conductive films in which components are uniformly dispersed. Therefore, in this invention, a silane coupling agent is added and the affinity of electroconductive oxide fine particle and a coloring agent (especially organic or inorganic pigment) is improved. That is, since organic functional groups such as vinyl group, phenyl group, epoxy group, amino group and mercapto group of the silane coupling agent have affinity with organic or inorganic pigments, the affinity with the colorant used in the formation of the conductive film can be improved, so that the colorant And a conductive film in which the conductive fine particles are uniformly dispersed can be formed. In addition, since the silane coupling agent includes an alkoxy group having affinity with the inorganic material, the bonding strength with the panel substrate can be improved to improve the mechanical strength of the conductive film.

It is preferable that the silane coupling agent is contained in the composition for forming a conductive film at 0.01 to 10% based on solids. If the content of the silane coupling agent is less than 0.01%, there is a problem that the addition effect is insignificant, and if the content of the silane coupling agent exceeds 10%, the conductivity is lowered. In addition, the silane coupling agent is preferably used around 10% based on the solids content of the inorganic components present in the composition. The addition amount of the said silane coupling agent can be adjusted according to the characteristic of the inorganic material used, and the kind of silane coupling agent.

The composition for forming a conductive film of the present invention is prepared by adding conductive oxide fine particles to an organic solvent to disperse the same, and adding a colorant and a silane coupling agent thereto. As the organic solvent, one or more alcohol solvents such as methanol, ethanol, n-butanol, isopropanol, diacetone alcohol, or methyl cellosolve, ethyl cellosolve, isopropyl cellosolve, and dimethylformamide may be used. The composition is applied using a conventional coating method such as spin coating, spray coating or dip coating, drying and firing to form a conductive film.

The coating film for a display device of the present invention is a conductive film formed by applying a composition for forming a conductive film on the outer surface of the panel for a display device; And an antireflection film formed by spin coating or dip coating a composition comprising a metal alkoxide or an oligomer thereof on the conductive film.

In the present invention, the conductive film formed by applying the composition for forming a conductive film on the outer surface of the panel for a display device; An antireflection film formed by applying a composition including a metal alkoxide or an oligomer thereof on the conductive film; And a diffuse reflection layer formed by spray coating a hydrolyzate including a metal alkoxide or an oligomer thereof on the anti-reflection film.

The antireflection film may be formed by spin coating or dip coating a metal alkoxide or oligomer with water, an organic solvent or a mixture thereof. The organic solvent may be one or more of an alcohol solvent such as methanol, ethanol, n-butanol, isopropanol, diacetone alcohol, or methyl cellosolve, ethyl cellosolve, isopropyl cellosolve, and dimethylformamide.

The metal alkoxide used for the antireflection film or the diffuse reflection layer has the following formula (2).

[Formula 2]

M (OR ') ₄

(Wherein, M is one element selected from the group consisting of Si, Ti, Sn and Zr, R 'is an alkyl group having 1 to 4 carbon atoms.)

The metal alkoxide oligomer preferably has a degree of polymerization of 2 to 10. When the degree of polymerization exceeds 10, there is a problem in that the viscosity is high and it is difficult to use.

Of these metal alkoxides, silicon alkoxides or oligomers thereof and fluorosilicates can be preferably used. Examples of the fluorosilicates include 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 Si (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 , CF ₃ CH ₂ CH ₂ SiCl ₃ and the like.

The following presents a preferred embodiment to aid the understanding of the present invention. However, the following examples are merely provided to more easily understand the present invention, and the present invention is not limited to the following examples.

<Example 1>

30 g of highly conductive ITO dispersion (10% solids) was added to 70 g of a mixed organic solvent of 10 g of methanol, 30 g of ethanol, 15 g of isopropyl alcohol, and 15 g of methyl cellosolve, followed by 2 g of a carbon black dispersion (10% of solids) as a colorant, and 0.3 g of phenyltrimethoxy silane (PTMS) was added as a silane coupling agent, and the composition for electrically conductive film formation was prepared. The conductive film-forming composition was spin-coated on a transparent glass panel, dried, and baked at 200 ° C. to form a conductive film.

<Example 2>

A conductive film was formed in the same manner as in Example 1 except that ATO was used instead of ITO fine particles.

Comparative Example 1

A conductive film was formed in the same manner as in Example 1 except that the silane coupling agent was not added.

The transmittance, surface resistance, and electromagnetic shielding of the ultra low frequency (VLF) in the range of 2 kHz to 400 kHz of the conductive films prepared in Examples 1 and 2 were measured, and the results are shown in Table 1 below.

Transmittance (%) Surface resistance (kΩ) Electromagnetic shielding degree (V / m) Electromagnetic shielding standard Example 1 65 30 or less 0.85 or less TCO compatible (1 V / m or less) Example 2 65 10 ⁷ 1.3 MPR-II compatible (2.5 V / m or less)

It can be seen from the results of Table 1 that the conductive film prepared according to the present invention has a low surface resistance. The electromagnetic shielding of ultra low frequency limited by the TCO standard is less than 1 V / m when measuring electromagnetic waves 30 cm away from the monitor. The electromagnetic shielding standard proposed by the Measure and proof Radiation Board (MPR-II), also one of Sweden's regulations, is 2.5 V / m or less when measured 50 cm away from the monitor. Therefore, since the conductive film according to the present invention satisfies all TCO or MPR-II standards, it can be seen that the electromagnetic wave shielding degree is also excellent.

Film strength, film hardness, and surface roughness of the conductive films of Examples 1 and 2 and Comparative Example 1 were measured, and the results are shown in Table 2 below. The eraser test was reciprocated 100 times at a constant speed at 10 cm with a 1 kg load, and then visually confirmed whether the surface condition changed. The eraser used for the test used a standard product. Surface roughness was measured by an industrial atomic force microscope.

Membrane Strength (Eraser Test) Film hardness (pencil hardness) Surface roughness Average height Example 1 Even 100 times 7 ~ 8 H 74.7 279 Comparative Example 1 Traces occur 50 times 7 H 120 450

It can be seen that the conductive film of the present invention is excellent in mechanical strength such as film strength or film hardness.

In the composition for forming a conductive film of the present invention, by applying metal oxide fine particles instead of metal colloids, manufacturing costs can be lowered and productivity can be increased. In addition, by using a colorant, the transmittance and body color of the conductive film can be easily adjusted, and by adding a silane coupling agent as the coupling agent, the colorant and the conductive oxide fine particles can be uniformly dispersed to form a uniform thin film, and mechanical strength Can also be improved.

Claims (13)

Metal oxide fine particles; coloring agent; And a silane coupling agent. The composition of claim 1, wherein the metal oxide fine particles are 0.5 to 6% based on solids, the colorant is 0.01 to 10% based on solids, and the silane coupling agent is 0.01 to 10% based on solids. The method of claim 1, wherein the metal oxide fine particles are selected from the group consisting of indium tin oxide (ITO), antimony tin oxide (ATO), aluminum zinc oxide (AZO), SnO ₂ , In ₂ O ₃ and Sb ₂ O ₃ oxides. A conductive film forming composition. The composition for forming a conductive film according to claim 1, wherein the colorant is at least one selected from the group consisting of organic or inorganic pigments and metal complexes. The method of claim 4, wherein the colorant is carbon black, graphite, TiO, TiN, TiO _1-x N _x (0 <x <1), TiC, TiN-TiC, cobalt oxide, zinc oxide, iron oxide, ruthenium oxide, oxidation A composition for forming a conductive film, which is at least one selected from the group consisting of aluminum, metal complex azo dyes, metal complex anthraquinone dyes, and mixtures of two or more thereof. The composition for forming a conductive film of claim 1, wherein the silane coupling agent is a compound represented by the following Chemical Formula 1. [Formula 1] YRSiX ₃ Wherein Y is one organic functional group selected from the group consisting of vinyl group, phenyl group, epoxy group, amino group, and mercapto group having affinity (or reactivity) with the organic material, R is an alkyl group, and X is an inorganic material Alkoxy group having affinity (or reactivity) A conductive film for display device manufactured from the composition for forming a conductive film of any one of claims 1 to 6. A conductive film prepared from the composition for forming a conductive film of any one of claims 1 to 6; And an anti-reflection film formed by coating a composition including a metal alkoxide or an oligomer thereof on the conductive film. The coating film for a display device according to claim 8, wherein the metal alkoxide is represented by the following Chemical Formula 2. 10. [Formula 2] M (OR ') ₄ (Wherein, M is one element selected from the group consisting of Si, Ti, Sn and Zr, R 'is an alkyl group having 1 to 4 carbon atoms.) The coating film of claim 8, wherein the polymerization degree of the metal alkoxide oligomer is 2 to 10. 10. A conductive film prepared from the composition for forming a conductive film of any one of claims 1 to 6; And an antireflection film formed by applying a composition including a metal alkoxide or an oligomer thereof on the conductive film. And a diffuse reflection layer formed by spray coating a hydrolyzate including a metal alkoxide or an oligomer thereof formed on the anti-reflection film. The coating film of claim 11, wherein the metal alkoxide is represented by the following Chemical Formula 2. 14. [Formula 2] M (OR ') ₄ (Wherein, M is one element selected from the group consisting of Si, Ti, Sn and Zr, R 'is an alkyl group having 1 to 4 carbon atoms.) The coating film of claim 11, wherein the degree of polymerization of the metal alkoxide oligomer is 2 to 10. 13.