KR20240110222A - Transparent high electroconductive coating composition, manufacturing method of the electroconductive composition and Electroconductive coating film prepared using the composition - Google Patents

Abstract

In the present invention, a coating film is formed by polymerization of a crosslinking agent and crosslinking reaction with the polymer, including a crosslinking agent, an electrically conductive polymer PEDOT/PSS conductive polymer aqueous dispersion, a silane compound, a surface additive, and the remaining solvent, and has excellent heat resistance and temperature resistance as a coating film. It is a highly conductive coating liquid composition that improves moisture resistance and durability and has excellent solvent resistance.

Description

Transparent high electroconductive coating composition, manufacturing method of the electroconductive composition and Electroconductive coating film prepared using the composition}

The present invention relates to a transparent highly conductive coating composition, a manufacturing method thereof, and a conductive coating film manufactured using the composition. Specifically, it can be cured at low temperature or in a short time, and can be easily applied by wet coating. In addition, the applied and cured coating film relates to a conductive coating liquid composition having excellent adhesion to glass or film, strong durability, and characteristics of high transparency and high conductivity, and a method of manufacturing the same.

Most mobile devices and automation devices in use recently are equipped with a touch screen panel (hereinafter referred to as 'TSP'). TSP refers to a screen that detects the location and performs specific processing when an external force, such as a hand or a pen, is applied to letters or signals displayed on the screen without using the keyboard. These TSPs absolutely require transparent electrodes using highly conductive materials. Most transparent electrodes are made of inorganic metal oxides such as indium tin oxide (hereinafter referred to as 'ITO') and are used by dry coating on film or glass using a vapor deposition method.

Representative types of TSP include those that use transparent electrodes coated on a film substrate, such as GFF, GF2, and GF1, and those that use transparent electrodes coated on glass, such as GG, G1, and G2. Transparent electrodes are installed inside the TSP. Rather than attaching a film to glass using OCA (Optically Clear Adhesive), etc., a method of implementing an electrode layer directly through deposition of an inorganic metal oxide such as ITO on glass is widely used to simplify the process and reduce production costs.

The problem with dry coating for depositing inorganic metal oxides such as ITO is that the raw materials themselves are expensive, excessive process costs are consumed for deposition, and indium, the main raw material for ITO, is among the commonly used inorganic metal oxides. Silver is a limited mineral and is rapidly being depleted as the display market expands. As a result, a further increase in price is inevitable.

Accordingly, in order to improve the conductivity of polyethylenedioxythiophene, which has been conventionally used as a coating material, a coating solution capable of dispersion in water was prepared by using a high molecular acid salt such as polystyrene sulfonate as a doping material, and its miscibility with alcohol solvents. , it had excellent processability and could be used as a coating material for various purposes, including the surfaces of glass and plastic films.

However, although polyethylenedioxythiophene conductive polymer has excellent transparency, it must be coated with low concentration of polyethylenedioxythiophene to maintain high transparency of 95% or more, and alkoxysilane [RSi(OR1) ₃ is added to increase the adhesion of the membrane. ] (In this case, R is methyl, ethyl, propyl or isobutyl, and R1 is methyl or ethyl), there is a problem that the conductivity is further reduced due to the non-conductive silica sol. In addition, the polymer membrane formed as a result has the disadvantage of being extremely vulnerable to moisture, so when left for a long period of time or exposed to a high humidity environment, the electrical properties of the polymer membrane change significantly, making commercialization difficult.

Therefore, research is needed on high-conductivity coating materials that enable wet coating with low processing costs, allow free supply and demand of raw materials, and have excellent durability even in environments with high humidity.

Accordingly, the present inventor prepared a highly conductive coating composition containing a crosslinking agent, and thus completed the present invention, which can be cured at low temperature or in a short time, can be easily applied by wet coating, and has excellent durability and adhesion.

Republic of Korea Patent Publication No. 10-1406678

The present invention provides a transparent, highly conductive coating liquid composition that can be cured at low temperature or in a short period of time, can be easily applied by wet coating, and the applied and cured coating film has the characteristics of high transparency and high conductivity with excellent durability and adhesion, and a method for producing the same. And to provide a conductive coating film manufactured using the composition.

However, the technical problem to be achieved by the present invention is not limited to the problems mentioned above, and other problems not mentioned can be clearly understood by those skilled in the art from the description below.

According to one embodiment of the present invention, a highly conductive coating liquid composition comprising 1.0 to 20.0% by weight of a crosslinker, 10.0 to 80.0% by weight of an electrically conductive polymer PEDOT/PSS conductive polymer aqueous dispersion, 0.01 to 5% of a surface additive, and the remainder of the solvent. provided.

In the present invention, the crosslinking agent may be a highly conductive coating liquid composition that is a water-soluble crosslinking agent.

In the present invention, the water-soluble crosslinking agent can form a coating film through a polymerization reaction with a polymer substrate having a carboxyl group (-COOH) or hydroxyl group (-OH).

In the present invention, the crosslinking agent is methyl, melamine, urea, aziridine, oxazoline, cellulose, and water-soluble phenol. It may be one or more selected from the group.

In the present invention, the electrically conductive polymer PEDOT/PSS conductive polymer aqueous dispersion may exist in the form of cationic polythiophene and anionic polystyrenesulfonic acid ionic complex as a counter-ion.

In the present invention, the electrically conductive polymer PEDOT/PSS conductive polymer aqueous dispersion may contain PEDOT poly(3,4-ethylenedioxythiophene) and PSS (polystyrenesulfonic acid) at a molar ratio of 1:1 to 5.

In the present invention, it further includes 0.01 to 20.0% by weight of a silane-based compound, and the silane-based compound may include any one or more selected from the group consisting of polysiloxane, silane, dimethyl polysiloxane, trimethoxy silane, or silazane. there is.

In the present invention, the surface additive may be made of polysiloxane or polyacrylic.

In the present invention, the solvent is 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 monomethyl ether, Ethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol monopropyl ether, diethylene glycol 2-ethylhexyl ether, methyl alcohol, isopropyl alcohol, ethyl alcohol, butyl alcohol, methyl ethyl ketone, acetone, toluene, It may include a first solvent containing at least one selected from the group consisting of xylene, ethyl acetate, butyl acetate, and purified water.

In the present invention, the solvent is dimethyl sulfoxide, ethylene glycol, glycerin, sorbitol, formamide, N-methylformamide, N,N-dimethylformamide, acetamide, N-methylacetamide, N-dimethylacetamide, n , a second solvent containing at least one selected from the group consisting of n-dimethyl formamide, tetrahydrofuran, n-methyl-2-pyrrolidinone, nitromethane, and acetonitrile, relative to 100 parts by weight of the first solvent. It may contain an additional 1.0 to 20.0 parts by weight.

According to the present invention, curing is possible at low temperature or in a short time using a crosslinking agent and an electrically conductive polymer aqueous dispersion of PEDOT/PSS conductive polymer, and it can be easily applied using a wet coating method, so productivity is excellent and process costs can be reduced. there is

In addition, the surface resistance can be lowered to 130Ω/□ or less, and with transparency of more than 90%, it can be used as a highly conductive transparent electrode.

In addition, the highly conductive coating liquid composition of the present invention can be applied to upper and lower electrodes applied to TSP, inorganic electroluminescent device (EL) electrodes for mobile phones, etc. In addition, transparent electrodes coated with inorganic metal oxides such as ITO are difficult to apply to electrodes of flexible displays due to their lack of flexibility, but since the conductive coating liquid composition with electromagnetic wave shielding function of the present invention is flexible, it can be used for flexible displays in the future. It can also be applied as an electrode, leading the flexible display market, and can also be applied as a highly conductive coating layer for large-area television and computer monitor screens.

Hereinafter, in order to explain in more detail, examples will be given in detail. However, the following examples are illustrative and the scope of the present invention is not limited thereto.

According to one embodiment of the present invention, a highly conductive coating liquid composition containing 1.0 to 20.0% by weight of a crosslinker, 10.0 to 80.0% by weight of an electrically conductive polymer PEDOT/PSS conductive polymer aqueous dispersion, 0.01 to 5% of a surface additive, and the remainder of the solvent. to provide.

The highly conductive coating liquid relates to a conductive coating liquid composition with electromagnetic interference (EMI) shielding properties used in transparent electrodes. Problems such as excessive process cost consumption, securing of raw materials, and price increase due to the dry coating method of depositing inorganic metal oxides such as ITO are encountered. can be solved. In addition, it has excellent adhesion to glass or film, has electromagnetic wave shielding properties, and has characteristics of high transparency and high conductivity.

The highly conductive coating solution according to the present invention does not use a binder, which is generally used as a component of the coating film, but is composed by introducing a cross-linking agent, thereby forming a coating film through self-polymerization of the cross-linking agent and cross-linking reaction with the polymer component.

In addition, the coating film formed as a result has excellent high conductivity and electromagnetic wave shielding properties while improving durability of heat resistance and anti-temperature and humidity resistance, and has excellent solvent resistance even when heat cured at low temperature and for a short time.

In the present invention, the crosslinking agent may be a water-soluble crosslinking agent, and accordingly, the water-soluble crosslinking agent can form a coating film through a polymerization reaction with a polymer substrate having a carboxyl group (-COOH) or hydroxyl group (-OH).

In the present invention, the crosslinking agent is methyl, melamine, urea, aziridine, oxazoline, cellulose, and water-soluble phenol. It may be one or more selected from the group.

The methyl-based and melamine-based crosslinking agent may be one or more selected from the group consisting of Methylated melamine, Mixed etherized melamine, Methylated benzoguanamine, Melamine-Formaldehyde (NIKALAC MW-12LF, manufactured by Sanwa Chemical, Japan, etc.), and Butylated melamine. You can.

The urea-based crosslinking agent may be alkylated urea, for example, methylated urea such as MX-270 or MX-280 manufactured by Sanwa Chemical Company of Japan.

The aziridine-based crosslinking agent is 2-Methyl Aziridine Propylene Imine, 2-Ethyl Aziridine Butylene Imine, 1,1'-(1,3-Phenylenedicarbonyl)bis(methylaziridine), 1,1',1''-( benzene-1,3,5-triyltricarbonyl)tris[2-ethylaziridine], Trimethylolpropane tris(2-methyl-1-aziridine propionate, Trimethylolpropane tris(β-N-aziridinyl) propionate, Pentaerythritol tris[3-(1-aziridinyl) propionate] and Pentaerythritol tris(2-methyl-1-aziridine propionate).

The oxazoline compound crosslinking agent is 2-Oxazoline, 2,2-m-phenylene-bis (2-oxazoline) [2,2-m-phenylene-bis (2-oxazoline)] or 2-Methyl It may be 2-alkenyl-2-oxazoline, such as -2-oxazoline, or it may be EPOCROS Series WS-300, WS-500, products of Sanwa Chemical Company of Japan.

The cellulose-based compound may be CNF (Cellulose Nano Fiber) or CNC (Cellulose Nano Crystal).

The water-soluble phenol-based compound crosslinking agent may be a phenol-based compound or a phenol/aldehyde-based compound.

For example, bisphenols that can be used in phenolic compounds include 4,4'-isopropylidene-diphenol (known as bisphenol-A), 4,4'-methylidene-diphenol (known as bisphenol-F) ) and alkylated phenol or bisphenol such as 4,4'-sec-butylidene-diphenol.

In addition, the phenol/aldehyde compound is any one selected from the group consisting of formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde, n-valeraldehyde, caproaldehyde, heptaldehyde, and straight-chain aldehydes having about 8 or less carbon atoms. It could be more than that.

In the present invention, the crosslinking agent may be included in an amount of 1.0 to 20.0% by weight, 2 to 18% by weight, 3 to 17% by weight, or 4 to 16% by weight relative to the total weight of the highly conductive coating liquid composition, and is used for self-polymerization of the crosslinking agent and crosslinking reaction of the polymer. In terms of improving, a urea-based, arizidine-based or oxazoline-based crosslinking agent may be suitably included in an amount of 5 to 15% by weight, but is not limited thereto.

For example, if the crosslinking agent is included in less than 1.0% by weight, a problem may occur in which no crosslinking reaction occurs, and if it is included in more than 20.0% by weight, a problem of no practical benefit may occur compared to when it is included in less than 20.0% by weight. .

Therefore, when the crosslinking agent is included in an amount of 1.0 to 20.0% by weight, it is possible to form a coating film through a polymerization reaction with the polymer substrate, and the coating film of the formed transparent electrode has the effect of lowering the surface resistance to 130 (Ω/□) or less.

The electrically conductive polymer PEDOT/PSS conductive polymer aqueous dispersion of the present invention may exist in the form of cationic polythiophene and anionic polystyrenesulfonic acid ionic complex as a counter-ion.

In the present invention, the electrically conductive polymer is cationic polythiophene, and the counter-ion of cationic polythiophene is an aqueous dispersion of the polymer that exists in the form of an ionic complex.

At this time, the aqueous dispersion of the polymer is an aqueous dispersion of ionic polymers of poly(3,4-ethylenedioxythiophene) (PEDOT) and polystyrene sulfonate (PSS). The PEDOT/PSS conductive polymer aqueous dispersion may be an aqueous dispersion in which polyethylenedioxythiophene (PEDOT) is doped with polystyrene sulfonate (PSS).

Additionally, polystyrenesulfonic acid is also called polystyrenesulfonate or polystyrenesulfonate.

The cationic polythiophene is a conductive polymer and may be a polythiophene consisting of repeating units of the general formula (i) or (ii) below, or a polythiophene having a combination of units of (i) and (ii). and suitably may be polythiophene having a repeating unit of general formula (ii) below.

At this time, A represents an optionally substituted C1-C5 alkylene radical, and Rx represents an optionally substituted C1-C18 alkyl radical in linear or branched form, an optionally substituted C5-C12 cycloalkyl radical, or an optionally substituted C1-C18 alkyl radical. represents a C6-C14 aryl radical, an optionally substituted C7-C18 aralkyl radical, an optionally substituted C1-C4 hydroxyalkyl radical or a hydroxyl radical, and x represents an integer from 0 to 8, , in the case where several radicals R are bound to A, they may be the same or different.

Formulas (i) and (ii) are to be understood as meaning that the Rx substituent may be attached to the alkylene radical A.

In addition, A of the polythiophene having a repeating unit of general formula (ii) may represent an optionally substituted C2-C3 alkylene radical, and x may represent 0 or 1.

In the present invention, in addition to the repeating units of general formula (i), (ii) or (i) and (ii), the polythiophene may optionally also contain other repeating units, and all repeats of the polythiophene At least 50% of the units, preferably at least 75% and most preferably at least 95%, have the structure of general formula (i), (ii) or (i) and (ii), preferably general formula (ii). It is desirable to have it. The percentage value may express the numerical content of units of structural formulas (i) and (ii) among the total number of monomer units in the externally-doped conductive polymer.

The polythiophene comprises a structure of formula (i), (ii) or (i) and (ii), preferably formula (ii), with a total of n repeat units, where n is 2 to 2,000, preferably Typically, it is an integer from 2 to 100. The repeating units of formula (i), (ii) or (i) and (ii), suitably formula (ii), may in each case be the same or different within the polythiophene. In each case, polythiophenes having the same repeating units of general formula (ii) are preferred.

In addition, at least 50%, 75%, or 95% of all repeating units of polythiophene may be composed of 3,4-ethylenedioxythiophene units, most preferably 100 3,4-ethylenedioxythiophene units. %, the conductive polymer may be poly(3,4-ethylenedioxythiophene).

Additionally, the polythiophene may have H on the end group in each case.

In the context of the present invention, the C1-C5 alkylene radical A is suitably methylene, ethylene, n-propylene, n-butylene or n-pentylene.

The C1-C18 alkyl radical R is preferably a linear or branched C1-C18 alkyl radical, such as methyl, ethyl, n- or iso-propyl, n-, iso-, sec- or tert-butyl, n-pentyl, 1 -Methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-ethyl, propyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, n-hexyl, n-heptyl, n -octyl, 2-ethylhexyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-hexadecyl or n-octadecyl, C5- C12 cycloalkyl radical R represents, for example, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl or cyclodecyl, C6-C14 aryl radical R represents, for example, phenyl or naphthyl, C7-C18 aralkyl radicals R are, for example, benzyl, o-, m-, p-tolyl, 2,3-, 2,4-, 2,5-, 2,6-, 3,4-, Represents 3,5-xylyl (xylyl) or mezytyl (mesityl).

In the context of the present invention, many organic groups are possible as optional additional substituents of radical A and/or radical R, for example alkyl, cycloalkyl, aryl, aralkyl, alkoxy, halogen, ether , thioethers, disulfides, sulfoxides, sulfones, sulfonates, aminos, aldehydes, ketos, carboxylic acid esters, carboxylic acids, carbonates, carboxylates, cyano, alkylsilanes and alkoxysilane groups and carboxamides. (carboxamide) group.

The polythiophene is preferably cationic, with “cationic” relating only to the charges on the polythiophene main chain. Positive charges are not visible in the above equation because their precise number and location cannot be absolutely determined. However, the number of positive charges is at least 1 and at most n, where n is the total number of all repeating units (same or different) in the polythiophene.

For example, to compensate for the positive charge, cationic polythiophene requires an anion as a counter-ion, so the counter-ion is suitably a polymeric anion (polyanion).

In this connection, the conducting polymer is suitably a cationic polythiophene, which exists in the form of ionic complexes of the cationic polythiophene and the polymeric anion as counter-ion.

Therefore, it is most appropriate for the conductive polymer to exist in the form of poly(3,4-ethylenedioxythiophene) and an ionic complex of polystyrenesulphonic acid (PEDOT: PSS). do.

The polymeric anion or polyanion is a monomeric anion as a counter-ion, and can contribute to film formation to form a thermally stable electrically conductive film.

For example, the polyanion is an anion of polymeric carboxylic acids such as polyacrylic acid, polymethacrylic acid, or polymaleic acid, or polymeric sulfonic acids such as polystyrenesulfonic acid and polyvinylsulfonic acid, and these polycarboxylic acids Boxylic and -sulfonic acids can also be copolymers of vinylcarboxylic acid and vinylsulfonic acid with other polymerizable monomers such as acrylic esters and styrene. In particular, it may contain a solid electrolyte of the anion of polymeric carboxylic acid or sulfonic acid to compensate for the positive charge of polythiophene, and may preferably contain polystyrenesulfonic acid (polystyrenesulfonate).

When polythiophene, specifically poly(3,4-ethylenedioxythiophene), is used, as already described above, the anion of polystyrene sulfonic acid (PSS) is in the form of the PEDOT:PSS ionic complex known from the prior art. The ionic complex can be obtained by oxidatively polymerizing 3,4-ethylenedioxythiophene, a thiophene monomer, in an aqueous solution in the presence of polystyrenesulfonic acid.

For details, see, for example, chapter 9.1.3 of “PEDOT ·Principles and Applications of an Intrinsically Conductive Polymer”, Elschner et al., CRC Press (2011).

The molecular weight of the polyacid supplying the polyanion is suitably 1,000 to 2,000,000, most suitably 2,000 to 500,000.

Poly acids or alkali metal salts thereof can be obtained commercially, for example polystyrenesulfonic acid and polyacrylic acid, or can be prepared by known processes (e.g. Houben Weyl, Methoden der organischen Chemie, vol. E 20 Makromolekulare See Stoffe, part 2, (1987), p. 1141 et seq.).

The ionic complex of polythiophene and polyanion, especially the PEDOT:PSS ionic complex, is suitably present in the highly conductive coating liquid composition in the form of particles. These particles in the composition have a specific resistance of less than 10,000 ohm·cm.

The PEDOT:PSS ionic complex particles in the highly conductive coating composition may have a d ₅₀ in the range of 1 to 100 nm, or suitably in the range of 1 to 60 nm. Most suitably, it may have a d ₅₀ in the range of 5 to 40 nm.

At this time, the d ₅₀ value of the diameter distribution means that 50% of the total weight of all particles in the dispersion can be given to particles with a diameter less than the d ₅₀ value. The particle diameter is determined through ultracentrifuge measurements. A common procedure is Colloid Polym. Sci.267, 1113-1116 (1989).

The electrically conductive polymer PEDOT/PSS conductive polymer aqueous dispersion of the present invention may contain PEDOT poly(3,4-ethylenedioxythiophene) and PSS (polystyrenesulfonic acid) at a molar ratio of 1:1 to 5, and water In terms of improving dispersibility, heat resistance, and atmospheric stability, it may be appropriately included in a molar ratio of 1:2 to 3. It is not limited to this. A representative product that has been commercialized accordingly is the Clevios series from Germany's Heraeus.

The PEDOT/PSS conductive polymer aqueous dispersion may be included in an amount of 10.0-80.0% by weight, 11-75% by weight, 13-70% by weight, or 15-65% by weight relative to the total weight of the conductive coating composition, and has a significantly high light transmittance and low In terms of having a haze value, it may be most appropriately included in an amount of 20 to 60% by weight.

If the content of the PEDOT/PSS conductive polymer aqueous dispersion is less than 10.0% by weight, it may be difficult to realize high conductivity, and if it exceeds 80.0% by weight, light transmittance decreases and haze increases as the coloring conductive polymer increases. It may cause problems with optical properties, such as increased temperature, and problems with dispersibility within the conductive coating liquid composition may occur.

In addition, when forming a transparent electrode using only the PEDOT/PSS conductive polymer aqueous dispersion and a general binder (acrylic binder resin or polyurethane binder resin), the surface resistance of the transparent electrode is very high, around 10 ³ ~10 ⁴ Ω/□. There are problems with using it as a transparent electrode for displays.

To lower the surface resistance of transparent electrodes made of these PEDOT/PSS conductive polymers, dimethyl sulfoxide (DMSO), ethylene glycol, glycerin, sorbitol, formamide (FA), and N-methylform. Amide (NMFA), N,N-dimethylformamide (DMF), acetamide (AA), N-methylacetamide (NMAA), N-dimethylacetamide (DMA), n,n-dimethylformamide (DMF) Although it is possible to consider adding a solvent with a high dielectric constant such as tetrahydrofuran (THF) and n-methyl-2-pyrrolidinone (NMP), it is still insufficient to be used as a conductive coating liquid composition for transparent electrodes. In addition, there is a problem that the surface resistance increases further due to incompatibility with the binder used in the coating liquid composition. Considering this, the present invention uses a water-soluble crosslinking agent that forms a coating film through a polymerization reaction with the polymer substrate.

Therefore, when the PEDOT/PSS conductive polymer aqueous dispersion is included in an amount of 10.0 to 80.0% by weight relative to the total weight of the conductive coating composition, a coating film can be formed through a polymerization reaction with a water-soluble crosslinking agent, and the coating film of the formed transparent electrode has a surface resistance of 130 (Ω/). □) has the effect of lowering it to below.

In the present invention, the silane-based compound may include any one or more selected from the group consisting of polysiloxane, silane, dimethyl polysiloxane, trimethoxy silane, or silazane, and is contained in an amount of 0.01 to 20% by weight based on the total weight of the conductive coating liquid composition. may be included.

In the present invention, the surface additive may be made of polysiloxane or polyacrylic, and may be included in an amount of 0.01 to 5% by weight based on the total weight of the conductive coating liquid composition.

In the present invention, the solvent is 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 monomethyl ether, Ethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol monopropyl ether, diethylene glycol 2-ethylhexyl ether, methyl alcohol, isopropyl alcohol, ethyl alcohol, butyl alcohol, methyl ethyl ketone, acetone, toluene, It may include a first solvent containing at least one selected from the group consisting of xylene, ethyl acetate, butyl acetate, and purified water.

For example, the first solvent may include ethyl alcohol and purified water.

In the present invention, the solvent is dimethyl sulfoxide, ethylene glycol, glycerin, sorbitol, formamide, N-methylformamide, N,N-dimethylformamide, acetamide, N-methylacetamide, N-dimethylacetamide, n , a second solvent containing at least one selected from the group consisting of n-dimethyl formamide, tetrahydrofuran, n-methyl-2-pyrrolidinone, nitromethane, and acetonitrile, relative to 100 parts by weight of the first solvent. It may contain an additional 1.0 to 20.0 parts by weight.

For example, the second solvent may contain ethylene glycol or formamide, or a combination thereof, and when contained at less than 1% compared to the first solvent, the haze value may increase, and when contained at more than 20%. In this case, a problem of lowered conductivity may occur.

When the highly conductive coating composition according to the present invention is applied to glass or film and cured, a highly conductive coating film having a surface resistance of 130Ω/□ or less and an electromagnetic wave shielding function can be obtained.

The method of applying (coating) the conductive coating composition according to a preferred embodiment of the present invention is not particularly limited as long as it is a method commonly known in the relevant technical field, and depending on the shape of the glass or film, spin coating or robot It is not particularly limited to methods such as spray coating, dip coating, and flow coating, and any commonly used method can be used.

In addition, these methods may be used in combination, and the thickness of the transparent electrode coating layer (conductive coating film) formed in this way is appropriately 0.01 to 10 microns (㎛), preferably 0.1 to 5 microns (㎛).

In addition, any transparent support can be used as a film to which the highly conductive coating composition according to the present invention can be applied. In particular, PET (Polyethylene Terephthalate) can be used in various application fields such as electronics and communications, batteries, nanotechnology research, and aerospace. ) film, COP (Cyclo Olefin Polymer) film, or TAC (Tri-acetyl Cellulose) film are suitable.

It is advisable for this PET film to have a transmittance of 90% or more and a haze in the range of 0.5% or less.

Hereinafter, the present invention will be described in more detail through examples. These examples are only for illustrating the present invention in more detail, and it will be apparent to those skilled in the art that the scope of the present invention is not limited by these examples according to the gist of the present invention. .

Example

According to the composition ratio shown in the table below, the crosslinking agent or binder was added to the solvent (first solvent and second solvent) and stirred at a speed of 1000 rpm for 30 minutes to completely mix. While continuously stirring, the PEDOT/PSS conductive polymer aqueous dispersion was dropped at a rate of 5 g/min, and finally, a surface control additive was added and mixed uniformly at a rate of 1000 rpm for about 1 hour to prepare a coating liquid composition.

division bookbinder crosslinking agent first solvent secondary solvent Conductive polymer Additives for surface control Example 1 - MW12LF 10g ETOH 20gDI WATER 35g EG 2g
FA 2g 30g 1g Example 2 - GW752 10g ETOH 20gDI WATER 26g EG 1g
FA 2g 40g 1g Example 3 - MX279 10g ETOH 20gDI WATER 36g EG 1g
FA 2g 30g 1g Example 4 - WS-300 10g ETOH 20gDI WATER 26g EG 3g 40g 1g Comparative Example 1 A-1127 10g - ETOH 20gDI WATER 2g EG 2g
FA 1g 40g 1g Comparative Example 2 PU77 10g - ETOH 20DI WATER 26g EG 2g
FA 1g 40 1g DI WATER: Pure (Deionized water)
ETOH: ethyl alcohol
EG: ethylene glycol
FA: Formamide
Conductive polymer: Heraeus PEDOT/PSS conductive polymer
Additive for surface control: BYK-3441
MM803: Dooricem, melamine-based crosslinking agent
MW-12LF: Sanwa chemicals, melamine-based crosslinking agent
GW752: GEOWON's aziridine-based cross-linking agent
MX279: Urea-based crosslinking agent
WS-300: Nippon Shokubai's oxazoline-based crosslinking agent
A-1127: DSM, acrylic binder resin
PU77: Lamberti polyurethane binder resin

The coating solution compositions prepared according to Examples 1 to 4 and Comparative Examples 1 and 2 of Table 1 were applied to a transparent PET film (50㎛ urethane primer, Kolon) with #20 bar coating (Wet: 45.7). ㎛/㎡) and then heat-cured in a hot air drying oven at 100°C for 3 minutes to form a coating film. In order to compare and evaluate the physical properties of the coating film, the following experiment was performed and the results are shown in Table 2 below.

(1) Adhesion measurement

Adhesion was measured using NITTO-31B. The adhesion test results were classified as follows depending on the change in surface resistance and the presence or absence of the coating film.

① Less than 10Ω/□: Good, ② 10~20Ω/□: Average, ③ 20Ω/□: Excess and detachment of coating film: Poor.

(2) Surface resistance measurement

The surface resistance was measured at 10V using a Mitsubishi Chemical Loresta EP MCP-610 surface resistance meter.

(3) Light transmittance and haze

Using a spectrophotometer (NIPPON DENSHOKU, NDH-5000), PET film used for coating (50㎛ urethane primer, Kolon H34P, transmittance (T.T): 92.5%, haze: 0.8%) was used as a base film. The relative total light transmittance and haze were measured.

(4) Heat resistance and durability

After 500 hours at a temperature of 80℃, the results were classified as follows according to the change in surface resistance and the presence or absence of the coating film.

① Less than 25Ω/□: Good, ② 25~50Ω/□: Average, ③ 50Ω/□: Exceeding and detachment of coating film: Poor.

(5) Constant temperature and humidity durability

After 250 hours at a temperature of 85°C and a relative humidity of 85%, the changes in surface resistance and the presence or absence of the coating film were classified as follows.

① Less than 25Ω/□: Good, ② 25~50Ω/□: Average, ③ 50Ω/□: Exceeding and detachment of coating film: Poor.

(6) Solvent resistance

After thoroughly soaking the three solvents, ETOH (Ethyl alcohol), MEK (Methyl ethyl ketone), and Acetone, in a dustproof wiper (asahi kasei, BEMCOT M-3) and reciprocating 20 times with a 2Kg load, there is a change in surface resistance and detachment of the coating film. Depending on the presence or absence, it was classified as follows.

① Less than 10Ω/□: Good, ② 10~20Ω/□: Average, ③ 20Ω/□: Excess and detachment of coating film: Poor.

division Adhesion surface resistance
(Ω/□) light transmittance
(%) Haze
(%) heat resistance
durability constant temperature and humidity
durability Solvent resistance ETOH MEK Acetone Example 1 Good 115 92.5 0.3 Good Good Good Good Good Example 2 Good 130 93.3 0.3 Good Good Good Good Good Example 3 Good 109 92.8 0.4 Good Good Good Good Good Example 4 Good 110 93.1 0.3 Good Good Good Good Good Comparative Example 1 Good 122 92.3 0.4 Good commonly commonly error error Comparative Example 2 Good 117 92.8 0.5 commonly error error error error

Referring to Table 2, the coating film formed using the conductive coating liquid composition prepared by applying a crosslinking agent according to Examples 1 to 4 maintains the excellent adhesion effect with the PET substrate and has a low surface area of 130Ω/□ or less. It not only has resistance, transmittance of more than 92.5%, and haze of less than 0.4%, but also has excellent heat resistance and constant temperature and humidity durability. In addition, despite the relatively low temperature of 100℃ and 3 minutes and short heat curing conditions, it has excellent solvent resistance against three solvents, ETOH (Ethyl alcohol), MEK (Methyl ethyl ketone), and Acetone, showing physical properties suitable as a highly conductive coating liquid composition. It was.

Next, in the case of the coating liquid compositions prepared according to Comparative Examples 1 and 2, a coating film was formed by applying acrylic binder resin and polyurethane binder resin commonly used in the industry, and the adhesion, surface resistance, light transmittance and It was confirmed that basic performance such as haze was good.

However, it was found that not only was the heat resistance and constant temperature and humidity durability related to the product use period poor, but the solvent resistance, which is the performance required for applying the TCF film to the product, was also poor, and thus it was found to be unsuitable as a coating liquid composition. Could know.

Therefore, when a coating film is formed by applying a crosslinking agent according to Examples 1 to 4, it not only maintains excellent basic performance such as adhesion, surface resistance, light transmittance, and haze as a highly conductive coating film, but also maintains heat resistance and durability of constant temperature and humidity. It was found to be suitable as a conductive coating liquid composition due to its excellent solvent resistance.

Above, the present invention has been described in detail with preferred embodiments, but the present invention is not limited to the above embodiments, and various modifications may be made by those skilled in the art within the scope of the technical idea of the present invention. This is possible.

Claims (10)

1.0 to 20.0% by weight of cross-linking agent;
10.0 to 80.0% by weight of electrically conductive polymer PEDOT/PSS conductive polymer aqueous dispersion;
Surface additive 0.01~5% and
A highly conductive coating liquid composition including the remainder of the solvent. According to paragraph 1,
The highly conductive coating liquid composition wherein the crosslinking agent is a water-soluble crosslinking agent. According to paragraph 2,
The water-soluble crosslinking agent is a highly conductive coating liquid composition that forms a coating film through a polymerization reaction with a polymer base having a carboxyl group (-COOH) or hydroxyl group (-OH). According to paragraph 1,
The crosslinking agent is from the group consisting of methyl, melamine, urea, aziridine, oxazoline, cellulose, and water-soluble phenolic compounds. A highly conductive coating liquid composition that is at least one selected. According to paragraph 1,
The electrically conductive polymer PEDOT/PSS conductive polymer aqueous dispersion exists in the form of cationic polythiophene and anionic polystyrenesulfonic acid ionic complex as a counter-ion. Highly conductive coating liquid composition. According to paragraph 1,
The electrically conductive polymer PEDOT/PSS conductive polymer aqueous dispersion is a highly conductive coating liquid composition comprising PEDOT poly(3,4-ethylenedioxythiophene) and PSS (polystyrenesulfonic acid) in a molar ratio of 1:1 to 5. According to paragraph 1,
It further contains 0.01 to 20.0% by weight of a silane-based compound,
A highly conductive coating liquid composition wherein the silane-based compound includes at least one selected from the group consisting of polysiloxane, silane, dimethyl polysiloxane, trimethoxy silane, and silazane. According to paragraph 1,
A highly conductive coating composition wherein the surface additive is made of polysiloxane or polyacrylic. According to paragraph 1,
The solvent is 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 monomethyl ether, diethylene glycol mono. Ethyl ether, Diethylene glycol monobutyl ether, Diethylene glycol monopropyl ether, Diethylene glycol 2-ethylhexyl ether, methyl alcohol, isopropyl alcohol, ethyl alcohol, butyl alcohol, methyl ethyl ketone, acetone, toluene, xylene, A highly conductive coating liquid composition comprising a first solvent containing at least one selected from the group consisting of ethyl acetate, butyl acetate, and purified water. According to clause 9,
The solvent is dimethyl sulfoxide, ethylene glycol, glycerin, sorbitol, formamide, N-methylformamide, N,N-dimethylformamide, acetamide, N-methylacetamide, N-dimethylacetamide, n,n- 1.0 to 20.0 parts by weight of a second solvent containing at least one selected from the group consisting of dimethyl formamide, tetrahydrofuran, n-methyl-2-pyrrolidinone, nitromethane and acetonitrile, based on 100 parts by weight of the first solvent. A highly conductive coating liquid composition comprising more parts by weight.