KR100430989B1 - Rapid drying transparent conductive coating compounds - Google Patents

Abstract

The quick-drying transparent conductive coating liquid composition is disclosed. The coating liquid composition according to the present invention comprises a non-aqueous acrylic polymer binder solution; Conductive polymer aqueous solution; And an ether solvent or an alcohol solvent dissolving the binder solution and the conductive polymer aqueous solution. According to the present invention, by using a non-aqueous acrylic polymer binder instead of a silica sol or a water-soluble binder, a conductive film excellent in water resistance, hardness, transparency, conductivity, and the like can be formed in a short time at about 50 ° C.

Description

Rapid drying transparent conductive coating compounds

The present invention relates to a quick-drying transparent conductive coating liquid composition, and more particularly to a quick-drying transparent conductive coating liquid composition to which a non-aqueous non-water acrylic polymer binder is applied.

The transparent conductive film refers to a film having high light transmittance and excellent conductivity, and is widely applied to an antistatic film, an electromagnetic shielding film, a transparent electrode, and the like. Mainly, metal oxide films such as an ATO (Antimony Tin Oxide) film and an ITO (Indium Tin Oxide) film are widely used as such transparent conductive films.

In general, the metal oxide film is formed by a vacuum deposition method or a coating liquid coating method.

However, in the former case, since expensive equipment is required, manufacturing costs are high, and a heat treatment process of 300 ° C. or more is required, so that the substrate is not applicable to heat. In particular, since the vacuum equipment is very limited in size, it is practically impossible to apply the transparent conductive film to a large area.

In the latter case, the transparent conductive film may be formed at a lower temperature than the former, but in preparing the coating agent, nano-sized sol particles should be uniformly dispersed in the coating liquid. There arises a problem that the uniform dispersion is not made due to. If the dispersion is not uniform, transparency or the like is lowered, which is not preferable.

Therefore, a method of using a conductive polymer as a conductive material has been proposed and used so that the dispersion process of the sol particles is not necessary. As the conductive polymer, polyaniline, polypyrrol, polythiophene, polyethylene dioxythiophene, and the like have been proposed.

In the case of using a conductive polymer, a binder is particularly required for adhesion to the substrate and formation of a film. Examples of such binders include silica sol hydrolyzed with methyl silicate and ethyl silicate using an alcohol solvent and water, polyvinyl alcohol (PVA), polyvinylacetate (PVAc), and hydroxypropyl cellulose which are water-soluble polymers. (HPC) etc. are mentioned.

However, when the silica sol is used as the binder, it is difficult to use a film, plastic, or the like, which is weak to heat, because the curing temperature of the silica sol is usually higher than 100 ° C. and the curing time is also required for 30 minutes or more. In general, the conductive polymer has a strong acidity, the silica sol has a problem that the storage stability worsens because the pot life that can be used as a coating liquid is shortened because the viscosity increases under such acid conditions.

In the case of using a water-soluble polymer as a binder, the viscosity of the coating liquid is relatively free and the storage stability is excellent. However, the adhesive strength to substrates such as acrylic and polycarbonate is poor, and the film hardness is relatively low compared to that of silica sol. have. In addition, since the time required for evaporating moisture after coating is not only long, the water resistance is poor, and when washing with water or the like, there is a problem that the conductivity decreases.

Therefore, the technical problem to be achieved by the present invention, by using a non-aqueous polymer binder to compensate for the disadvantages of using a silica sol or a water-soluble polymer as a binder long pot life, good storage stability, adhesion, water resistance, transparency, surface It is to provide a quick-drying transparent conductive coating liquid composition having excellent resistance characteristics.

Fast drying transparent conductive coating composition according to the present invention for achieving the above technical problem, methyl methacrylate (Methylmethacrylate), methyl acrylate (Methylacrylate), ethyl acrylate (Ethylacrylate), normal butyl acrylate (n-Butylacrylate) , Normal butyl methacrylate (n-Butylmethacrylate), ethyl methacrylate (Ethylmethacrylate), isobutyl methacrylate (iso-Butylmethacrylate), methacrylic acid, isopropyl methacrylate (iso-Propylmethacrylate), 2 2-Ethylhexylacrylate, 1,6-hexanediol diacrylate, 2-Hydroxyethylmethacrylate, 2-hydroxyethyl acrylate Non-aqueous methacrylate comprising an acrylic polymer formed by polymerizing one or more selected from 2-hydroxyethylacrylate and acrylic acid. Reel polymer-based binder solution; polyethylene dioxythiophene-based, polyaniline-based, or a polypyrrole-based conductive polymer solution; And propylene glycol monopropyl ether, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, and diethylene glycol to dissolve the binder solution and the conductive polymer aqueous solution. Monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol-2-ethylhexyl ether and isopropyl alcohol, or any one of them It comprises an ether-based or alcohol-based solvent containing, wherein the binder solution is 1.00 to 50.0wt%, the conductive polymer aqueous solution is 1.00 to 90.0wt%, the solvent is contained in 50.0 to 98.0wt%, The conductive polymer is 0.01 to 2.0 with respect to the aqueous solution of the conductive polymer. It is contained in 0wt% and 10.0wt% or more with respect to the binder solution, at this time, so that the solutes dissolved in the solvent is not only well dispersed but also better adhesion to the substrate when forming a coating film Preferably, methylpyrrolidone or dimethylformamide is contained in the solvent. In forming the acrylic polymer, a polymerization initiator used to cause an acrylic copolymerization reaction may include azo-bis-isobutyronitrile; AIBN) or tert-butylperoxybenzoate (TBPB) and the like can be used.

Hereinafter, preferred embodiments of the present invention will be described in detail.

Example 1 Preparation of Binder Solution

First, 25 g of toluene was added to a 100 ml four-necked flask reactor and the temperature in the reactor was raised to 105 ° C., followed by 32 g of methyl methacrylate, 5 g of normal butyl acrylate, 2 g of ethyl methacrylate, 0.7 g of methacrylic acid, and azobisisobutyro. A solution of 0.2 g of nitrile was added dropwise to the reactor for 2 hours.

After the dropping was completed, the temperature in the reactor was adjusted to 110 to 115 ° C. and acrylic copolymerization reaction was carried out at this temperature for 3 hours. After 3 hours, a mixture of 4 g of toluene and 0.1 g of azobisisobutyronitrile was slowly added dropwise to the reactor and reacted at this temperature for 1 hour. After the reaction, the temperature in the reactor was cooled to 90 ° C., and 22 g of toluene and 9 g of isopropyl alcohol were diluted in order to prepare a non-aqueous acrylic polymer binder solution.

Example 2 Preparation of Binder Solution

Another example of the preparation of the binder solution is to first put 30 g of toluene in a 100 ml four-necked flask reactor, raise the temperature in the reactor to 105 ° C, and then 5 g of ethyl acrylate, 10 g of normal butyl acrylate, 15 g of methyl methacrylate, and 10 g of acrylic acid. And a solution of 0.2 g of tert-butyl peroxybenzoate were added dropwise to the reactor for 1.5 hours. After the dropping, the temperature in the reactor was adjusted to 110 ° C to 115 ° C and an acrylic copolymerization reaction was carried out at this temperature for 3.5 hours. Thereafter, a mixture of 4 g of toluene and 0.1 g of tert-butyl peroxybenzoate is slowly added dropwise and reacted at this temperature for 1 hour. After the reaction, the temperature was cooled to 90 ° C. and 20 g of toluene and 10 g of isopropyl alcohol were diluted in order to prepare a non-aqueous acrylic polymer binder solution.

Example 3 Preparation of Transparent Conductive Coating Liquid

First, 3 g of the binder solution prepared in Example 1 was taken into a 150 ml beaker, and 29.3 g of ethylene glycol monoethyl ether was added thereto, followed by sufficiently stirring to dissolve well. Into this beaker, 14 g of a conductive polymer solution containing 1.3 wt% of polyethylenedioxythiophene polystyrene sulfonate (PEDT / PSS), 20 g of ethylene glycol monomethyl ether, 32 g of propylene glycol monomethyl ether, and 1.7 g of normal methylpyrrolidone were added thereto. The solution was sufficiently stirred for about 30 minutes to prepare a transparent conductive coating solution.

Polyethylenedioxythiophene / Polystyrenesulphonate (PEDT / PSS) aqueous solution is a form in which a polymer of polystyrene sulfonate is added as a dopant to an aqueous solution of polyethylene dioxythiophene-based conductive polymer. Therefore, it is well soluble in water and excellent thermal stability and atmospheric stability can be expected.

Polyaniline-based conductive polymer aqueous solution or polypyrrole-based conductive polymer aqueous solution having excellent electrical conductivity and oxidation stability may be used instead of the conductive aqueous solution. However, when the conductive polymer solution is coated on a substrate, its transmittance is relatively low. It is highly preferred to use a deoxythiophene-based polymer aqueous solution.

The solvent used in the present invention is an ethylene glycol monomethyl ether and propylene glycol, which are ether solvents, in order to effectively dissolve an acrylic polymer binder and to disperse a polyethylenedioxythiophene-based conductive polymer in a coating solution to effectively exhibit electrical conductivity. Monomethyl ether was selected. In addition, propylene glycol monopropyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol Monobutyl ether, diethylene glycol-2-ethylhexyl ether, etc. may be used, and an alcoholic solvent can also be used. In addition, normal methylpyrrolidone (n-Methylpyrrolidone; NMP) was used as a solvent to help dispersibility of the aqueous polymer solution and to improve adhesion to the substrate, and instead of this solvent, dimethylformamide (N, N-Dimethylformamide). ; DMF) may be used.

Example 4 Preparation of Transparent Conductive Coating Liquid

As another example for preparing a transparent conductive coating solution, the one prepared according to Example 2 was used as a binder solution, except that 1.0 g of normal methylpyrrolidone in organic solvent was used instead of 1.7 g. In the same manner, a transparent conductive coating solution was prepared.

Example 5 Preparation of Transparent Conductive Coating Liquid

In another embodiment for preparing a transparent conductive coating agent, 2 g of the binder solution prepared in Example 1 was taken and placed in a 150 ml beaker. 48 g of ethylene glycol monoethyl ether was added thereto, followed by stirring to dissolve well.

8 g of an aqueous conductive polymer solution containing 1.3 wt% of polyethylenedioxythiophene / polystyrene sulfonate (PEDT / PSS), 4.5 g of ethylene glycol monomethyl ether, 21 g of propylene glycol monomethyl ether, 15 g of isopropyl alcohol, and normal methyl pyrroli 1.5 g of money was added thereto, followed by sufficient stirring for about 30 minutes to prepare a transparent conductive coating solution.

Example 6 Preparation of Transparent Conductive Coating Liquid

As another example for preparing a transparent conductive coating solution, the same method as in Example 5 was used except that 1.0 g instead of 1.5 g of normal methylpyrrolidone was used in the organic solvent. A transparent conductive coating liquid was prepared.

Example 7 Formation of Transparent Conductive Film

After coating the transparent conductive coating liquid prepared in Example 3 with a bar coater No. 7 on the three acrylic panels having a substrate size of 7 cm x 15 cm to have a moisture film thickness of 16 µm, the drying conditions of the coating film were 80 It was heat dried for 2 minutes at < RTI ID = 0.0 > C, < / RTI > In the case of the transparent conductive coating solution prepared in Examples 4 to 6, a transparent conductive film was formed in the same manner.

[Analysis table]

Table 1 shows the measurement results for the sheet resistance, transmittance, coating film hardness, adhesive force and water resistance of the transparent conductive film formed in Example 7.

Here, the sheet resistance was measured using a multi-meta, the transmittance was measured using an ultraviolet visible spectrophotometer (UV-Visible Spectrophotometer), the film hardness was measured by ASTM D3502 measuring method (pencil hardness measuring method). And the adhesive force was measured by ASTM D3359 (scotch tape test method). Water resistance was measured by immersing the resultant formed with a transparent conductive film in water for 24 hours and visually observing the surface state.

Referring to Table 1, it was completely dried within 10 minutes at about 50 ℃, it can be seen that the formed coating film almost maintains the transparency of the substrate with a high transmittance of 85% or more, that is, excellent transparency of the coating film. In addition, the surface resistance is also excellent in 10 ⁶ ~ 10 ⁷ Ω / □, showing that the hardness and adhesion of the physical properties of the coating film is also good, it can be seen that the water resistance is also excellent.

division Drying condition Transmittance (%) Sheet resistance (Ω / □) Coating hardness (H) Adhesion Water resistance Example 3 80 ° C x 2 minutes 85% 1 × 10 ⁶ 2H 100/100 No change 60 degrees Celsius * 5 minutes 88% 3 × 10 ⁶ H 100/100 No change 50 degrees Celsius * 10 minutes 90% 6 × 10 ⁶ H 100/100 No change Example 4 80 ° C x 2 minutes 88% 2 × 10 ⁶ H 100/100 No change 60 degrees Celsius * 5 minutes 90% 5 × 10 ⁶ H 100/100 No change 50 degrees Celsius * 10 minutes 90% 9 × 10 ⁶ H 100/100 No change Example 5 80 ° C x 2 minutes 90% 1 × 10 ⁷ H 100/100 No change 60 degrees Celsius * 5 minutes 90% 4 × 10 ⁷ H 100/100 No change 50 degrees Celsius * 10 minutes 92% 9 × 10 ⁷ HB 100/100 No change Example 6 80 ° C x 2 minutes 90% 2 × 10 ⁷ H 100/100 No change 60 degrees Celsius * 5 minutes 92% 5 × 10 ⁷ HB 100/100 No change 50 degrees Celsius * 10 minutes 92% 9 × 10 ⁷ HB 100/100 No change

According to the quick-drying transparent conductive coating liquid according to the present invention as described above, by using a non-aqueous acrylic polymer-based binder in place of silica sol or water-soluble binder, excellent water resistance, hardness, transparency, conductivity, etc. within a short time at about 50 ℃ A conductive film can be formed. Accordingly, the present invention can be applied to a wide range of parts, such as an electromagnetic shielding film, an antistatic film, and a transparent electrode.

The present invention is not limited to the above embodiments, and it is apparent that many modifications are possible by those skilled in the art within the technical spirit of the present invention.

Claims (6)

Methyl methacrylate, methyl acrylate, ethyl acrylate, normal butyl acrylate, normal butyl methacrylate, ethyl methacrylate, isobutyl methacrylate, methacrylic acid, isopropyl methacrylate, 2-ethylhexyl acrylate , 1,6-hexanediol diacrylate, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate and a non-aqueous acrylic polymer binder solution comprising an acrylic polymer formed by polymerizing one or more selected from acrylic acid ; Polyethylene dioxythiophene-based, polyaniline-based, or polypyrrole-based conductive polymer aqueous solution; And Propylene glycol monopropyl ether, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol mono so as to dissolve the binder solution and the conductive polymer aqueous solution Methyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol-2-ethylhexyl ether and isopropyl alcohol containing any one or a mixture thereof It comprises an ether or alcohol solvent containing; The binder solution is contained in 1.00 ~ 50.0wt%, the conductive polymer solution in 1.00 ~ 90.0wt%, the solvent is contained in 50.0 ~ 98.0wt%, the conductive polymer is contained in 0.01 ~ 2.00wt% with respect to the conductive polymer solution And the fast-drying transparent conductive coating liquid composition, characterized in that containing 10.0wt% or more with respect to the binder solution. delete delete delete The quick-drying transparent conductive coating liquid composition according to claim 1, wherein the solvent contains normal methylpyrrolidone or dimethylformamide. delete