WO2016029586A1 - Method for manufacturing flexible transparent conducting composite film - Google Patents

Abstract

Disclosed is a method for manufacturing a flexible transparent conducting composite film. The method comprises: immersing a transparent polymer film coated with an oxidizer film into a 3,4-ethylenedioxythiophene monomer solution, and carrying out chemical oxidation polymerization of the 3,4-ethylenedioxythiophene monomer on the polymer film surface to synthesize the conducting poly-3,4-ethylenedioxythiophene coating in situ, thereby obtaining the flexible transparent conducting composite film. The present invention gets rid of the problems of difficulty in formation of the poly-3,4-ethylenedioxythiophene film, difficulty in preparing the large-area high-quality conducting film, and difficulty in producing the non-ITO flexible transparent conducting film.

Description

 Flexible transparent conductive composite film manufacturing method

Technical field

 The invention belongs to the technical field of functional polymer materials, and particularly relates to a conductive poly 3,4- Synthesis of ethylene dioxythiophene coating and preparation of flexible transparent conductive film.

Background technique

 A flexible transparent conductive film often refers to a visible light transmittance of more than 80% and a surface resistance of less than 1000 Ω/□. Flexible film. It is a key material for the development of high-end optoelectronic products such as flexible displays, solar cells, touch panels, and electronic paper. At present, the flexible transparent conductive film is mainly for sputtering a transparent conductive indium tin oxide on the transparent polymer film ( ITO) compound. On the one hand, indium is a precious metal with limited resources; on the other hand, the ITO film is brittle and has poor flexibility. ITO The flexural fatigue life of the flexible transparent conductive film is low, and it is difficult to meet the market demand for a flexible transparent conductive film. Many research institutes and companies are committed to developing non-ITO The flexible transparent conductive film can be classified into an oxide system, a metal system, a conductive polymer system and a nano carbon material system depending on the conductor material.

 Oxide system

 Oxide-based flexible transparent conductive film, except indium tin oxide (ITO Outside of the coated film, a polymer film coated with a transparent zinc oxide semiconductor is representative of such products. Its performance varies greatly depending on the polymer substrate and the surface treatment and sputtering process. Further, the oxide semiconductor is large in brittleness and poor in flexibility. The oxide-based flexible transparent conductive film generally has a problem of low resistance to warpage and cannot meet the market demand.

 2. Metal system

 Metals such as silver, gold, and aluminum are good conductors of electricity when the thickness of the metal layer is less than 20 At the time of nanometer, it still has good electrical conductivity, but the absorption and reflection of visible light drop sharply, and it can exhibit a certain light transmittance. However, it is costly to uniformly plate a nano-scale metal layer on the surface of the polymer, and such a flexible transparent conductive film is difficult to have commercial value.

 Coating a photosensitive silver salt or nano silver particles is another method of preparing a flexible transparent conductive film. United States Cambrios 2008 The company announced the development of ClearOhm technology for the preparation of nano-silver and nano-silver inks for the preparation of flexible transparent conductive films. It is said that the silver wire has a wire diameter ratio of more than 300 and a wire diameter of about 100. Nano. The nano silver ink is coated on the transparent polymer substrate, and the randomly oriented nano silver wires constitute a mesh of less than 1 micrometer, and the obtained flexible film has a surface resistance of 50 to 300 Ω/□ and a light transmittance of about 92%. Cambrios is investigating the feasibility of using laser ablation technology to process transparent circuit boards while promoting the application of nano silver inks in touch panels.

 3. Conductive polymer system

 Poly 3, 4-ethylenedioxythiophene ( PEDOT It has excellent electrical conductivity and transparency and is a candidate material for preparing flexible transparent conductive films. However, the PEDOT material is insoluble and infusible and difficult to process into a film. PEDOT developed by Bayer The aqueous dispersion of poly(p-styrenesulfonic acid (PSS) complex, Baytron P, can be coated into a film, which solves the problem of PEDOT film formation to some extent. But insulated PSS The layer hinders the migration of charges, and the resulting PEDOT/PSS film has low conductivity and high hygroscopicity. Its conductivity and reliability cannot meet the requirements of the market. Many scientists and workers study EDOT In-situ polymerization of the monomer on the surface of the substrate, it is desirable to obtain a transparent film having better conductivity and stability while solving the film formation problem. Methods that have been explored include direct polymerization, solution polymerization, and chemical vapor deposition (CVD). And vapor phase deposition polymerization (VPP).

The direct polymerization method is a method in which a monomer is mixed with an oxidizing agent solution and then coated on a surface of a substrate, and the monomer is oxidatively polymerized by heating. In the direct polymerization process, once the monomer is mixed with the oxidant solution, oxidative polymerization has begun. Although the addition of inhibitors such as imidazole can prolong the pot life of the mixture, the conductivity of the obtained PEDOT film can reach the order of 100 S/cm, but the repeatability is not ideal, the conductivity can fluctuate in several orders of magnitude, and the direct polymerization method is used. Not universal.

The solution polymerization adsorption method is to place the substrate in a monomer solution, and then add an oxidizing agent solution for oxidative polymerization, so that the synthesized PEDOT is adsorbed and deposited on the surface of the substrate to form a PEDOT film. The PEDOT film obtained by the solution polymerization adsorption method has poor compactness, weak adhesion to the substrate, and low monomer utilization. Liang Jie et al. introduced a sulfonic acid group on the surface of PP to improve the adhesion between PEDOT and PP, and obtained a composite film with conductivity of 300 S/cm and transmittance of 90%.

Chemical vapor deposition (CVD) is the introduction of vaporized oxidant and monomer vapor into the reaction chamber, oxidative polymerization and deposition of the monomer on the surface of the substrate, cleaning to remove oxidant residues and low molecular oligomers, to obtain conductance Transparent PEDOT film with a rate exceeding 100 0S/cm. However, CVD requires special equipment, high process requirements, and a limited variety of oxidants to choose from, which is not suitable for large-scale production.

Vapor Deposition Polymerization (VPP) is the attachment of an oxidant to the surface of a substrate and then the deposition of monomeric vapor on the surface of the oxidant. In the 1980s, Xia Turing used a high-speed spin coater to coat the oxidant FeCl ₃ and surfactant on the surface of PET. After drying, it was exposed to EDOT vapor to deposit and polymerize the film on PET. A composite film having a light transmittance of more than 80% and a conductivity of more than 0.2 S/cm was obtained. Kim et al. used a similar method to settle and polymerize EDOT vapor at room temperature to obtain a transparent PET composite film having a surface resistance of 500 Ω/□.

Bjorn et al. found that in vapor phase deposition polymerization, the acidity of the solid Fe ⁺³ salt oxidant is sufficient to catalyze the addition polymerization of DEOT, resulting in conjugate defects and non-conductive products of the skeleton chain; the addition of volatile weak base in the oxidant can inhibit the addition. The side reaction is polymerized to obtain a pH window suitable for DEOT oxidative polymerization. Madl et al. incorporated pyridine in Fe(OTs) ₃ solution, coated on polyethylene naphthalate (PEN) surface, dried and exposed to EDOT steam at 50 °C to obtain conductivity of 600 S/cm. PEN/PEDOT composite film with a light transmittance of 94%.

 Fabretto et al found that humidity has a great influence on the vapor deposition polymerization of EDOT. VPP water molecules capture EDOT Hydrogen protons on dimeric or polycationic cations to construct a conjugated backbone chain of PEDOT. However, in a high humidity environment, the solid oxidant film is highly hydrated and crystallizes and loses its oxidative activity at PEDOT. A void defect is caused on the film.

 4. Nano carbon system

Both carbon nanotubes and graphene have good electrical conductivity. Some companies have researched carbon nanotube transparent conductive films, such as Unidym Company of the United States and Toray Corporation of Japan. Although the carbon nanotube transparent conductive film has the advantages of good flexibility and good moisture resistance, its resistance value is high, generally 500-2500 Ω/□. IBM is an early company that studies graphene transparent conductive films. Pohang University of Science and Technology in South Korea said that the resistance of graphene transparent conductive film can be reduced to 30 Ω/□ by HNO ₃ treatment, but the industrial production technology of continuous graphene film needs to be broken.

 As described above, at present, the flexible transparent conductive film is mainly plated with an ITO film, and has a high price, a scarce raw material, and a poor resistance to curvature. non- ITO Alternatives are under development, especially with conductive polyethylene dioxythiophene films and nano silver inks with strong competitiveness and market penetration. However, the conductive polymer is insoluble and insoluble, and is difficult to process into a film; polar substitution or ion complexation exacerbates the distortion of the planar conjugated chain and the tendency of the material to adsorb water vapor from the environment, reducing the electrical properties and reliability of the material; Gas phase precipitation polymerization (VPP) of EDOT monomer can be obtained with ITO The film is comparable to the transparent conductive film, but controlling the uniformity of the monomer concentration in the cavity under vacuum is a big problem, and the area of the obtained uniform film is small; in addition, the strong acidic solid oxidant is easy to cause 3,4- The side-addition reaction of ethylene dioxythiophene monomer causes a conjugate defect and a non-conductive product of the skeleton chain.

 To this end, the present invention discloses a conductive preparation on the surface of a transparent polymer film. Synthesis technology of PEDOT coating and method of preparing flexible transparent conductive film.

Summary of the invention

The object of the present invention is to overcome the above-mentioned deficiencies in the prior art and to provide a method for preparing a flexible transparent conductive film, which comprises in-situ synthesis of transparent conductive poly 3,4- on the surface of a transparent polymer substrate by liquid phase precipitation polymerization. A more specific technical solution of ethylene dioxythiophene coating is as follows.

 A method for manufacturing a flexible transparent conductive composite film, which comprises immersing a transparent polymer film covering an oxidant film into 3,4- The ethylenedioxythiophene monomer solution is subjected to chemical oxidative polymerization of 3,4-ethylenedioxythiophene monomer on the surface of the polymer film to synthesize a conductive poly(3,4-ethylenedioxythiophene) in situ. Flexible transparent conductive composite film .

 Further, during the preparation process, the oxidant continuously oxidizes and diffuses to the surface of the transparent polymer 3,4- The ethylenedioxythiophene monomer is polymerized to form a transparent conductive poly(3,4-ethylenedioxythiophene) coating.

Further, the oxidant film is an inorganic oxidant or an inorganic oxidant compounded with an organic peroxide; the inorganic oxidant is a physically adsorbed inorganic oxidant; and the organic peroxide is a surface chemically converted organic peroxide.

Further optimized, the inorganic oxidant is a ferric salt; the trivalent iron salt is one or more of ferric chloride, iron sulfate and iron p-toluenesulfonate; the inorganic oxidant is in a transparent polymer base. The adsorption capacity of the material is 0.2-10 mmol/m ² .

The surface chemistry further optimized is converted into one or more of hydrogen peroxide oxidation, peracid oxidation, ozone oxidation, vacuum ultraviolet photochemical oxidation, and oxygen plasma bombardment.

The organic peroxide further optimized is one or more of hydrogen peroxide, peroxyether, ketone peroxide and peroxyacid; the concentration of the organic peroxide on the surface of the transparent polymer substrate is 0-10 mmol. /m ² .

 Further optimized concentration of the 3,4-ethylenedioxythiophene monomer solution is 20-400 mmol/L The solvent of the solution is at least one of petroleum ether, hexane, heptane, cyclohexane, benzene, toluene, dichloromethane, chloroform, acetonitrile, butyl acetate, methyl ethyl ketone or butanol.

 The further optimized oxidative polymerization is carried out at 0-60 ° C for a reaction time of 0.02-12 hours, resulting in a poly 3,4- The ethylene dioxythiophene coating was washed with 0.1 to 0.5 M of dilute sulfuric acid.

 Further optimized substrate of the transparent polymer film Including polymethyl methacrylate, polycarbonate, polyethylene terephthalate, polyethylene naphthalate, cycloolefin polymer, polyimide, cured epoxy resin or silicone resin .

The further optimized transparent polymer film is surface-treated to form an oxidizing agent layer; the surface treatment comprises chemical modification, high-energy radiation modification and surfactant treatment; the surface chemical modification is hydrolysis or sulfonation, specifically Soak for 10 to 45 minutes with 10% NaOH aqueous solution or 30% H ₂ SO ₄ aqueous solution; the high energy radiation treatment is 172 nm vacuum ultraviolet photochemical oxidation or oxygen plasma treatment.

The process or experience of the present invention is further described below: the β position of the 3,4-ethylenedioxythiophene monomer is directly linked to oxygen, and the electron donating property of oxygen increases the electron cloud density on the thiophene ring and reduces the oxidation of the thiophene ring. Potential, under the action of oxidant, it is easy to couple polymerization; and the β position of the thiophene ring is occupied by oxidized ethylene. The thiophene ring can only be connected by α-α during oxidative polymerization to form a structurally conjugated chain to obtain conductivity. A conductive polymer with excellent transparency and stability. When the transparent polymer substrate coated with the oxidizer film is immersed in the 3,4-ethylenedioxythiophene monomer solution, the oxidizing agent is dissolved in the retention layer on the surface of the polymer substrate, and the 3,4-ethylenedioxythiophene in the retention layer is The monomers are oxidized to dimers, trimers, multimers and oligomers. Due to the insolubility of poly 3,4-ethylenedioxythiophene, the molecular weight of 3,4-ethylenedioxythiophene oligomer increases with the reaction time, and the solubility in the solvent is deteriorated, which will precipitate and adsorb to The surface of the polymer substrate. The 3,4-ethylenedioxythiophene monomer in the solution phase is continuously diffused into the retention layer by the concentration difference, supplementing the consumed 3,4-ethylenedioxythiophene monomer; at the same time, under the action of the oxidant The 3,4-ethylenedioxythiophene oligomer adsorbed on the surface of the substrate reacts with the precipitated 3,4-ethylenedioxythiophene monomer to grow into a polymer chain until the adsorbed oxidant is depleted, in the polymerization. A transparent conductive poly 3,4-ethylenedioxythiophene coating is formed on the surface of the substrate to obtain a flexible transparent conductive film.

 The performance of the flexible transparent conductive film prepared by the present invention is divided into the liquid phase precipitation polymerization of poly 3,4- In addition to the ethylene dioxythiophene coating, it is also related to the transparent substrate used. Optical grade transparent plastic Polymethyl methacrylate, polycarbonate, polyethylene terephthalate, cured epoxy resin, silicone resin, etc., with an ester group or a phenyl structural unit in the molecular chain, have certain chemical activity. The cycloolefin polymer is a newly developed optical grade transparent plastic with surface energy, gas permeability and low water absorption. It has outstanding chemical inertness and anti-aging ability, but High energy radiation can provoke chemical changes in the surface of the cyclic olefin polymer material. Polyethylene naphthalate and transparent polyimide are heat-resistant transparent plastics specially developed for optoelectronic products. They are sensitive to general chemical reagents and high-energy radiation.

The invention adopts a physical adsorption method to prepare an oxidizing agent film, and applies an oxidizing agent solution on the surface of the transparent polymer substrate by dip coating method, and forms an oxidizing agent film after the solvent is volatilized. The surface energy of the polymer is low, and the wettability of the polar oxidizing agent solution is poor, and the surface of the transparent substrate needs to be hydrophilically treated to improve the wettability of the surface of the substrate and the oxidizing agent solution. Surface chemical modification, high-energy radiation treatment, and surfactant treatment can all introduce polar groups on the surface of the polymer to improve the surface energy and wettability of the polymer. The surface chemical modification can be hydrolysis or sulfonation, and the polar carboxyl group or sulfonic acid group can be introduced on the surface of the polymer by soaking in 10% NaOH aqueous solution or 30% H ₂ SO ₄ aqueous solution for 10 to 45 minutes. Treatment with 172nm vacuum ultraviolet radiation or oxygen plasma for 2 minutes can introduce oxygen-containing groups on the surface of the polymer to reduce the contact angle of the polymer substrate to water below 20 °, and the surface of the substrate changes from hydrophobic to hydrophobic. Hydrophilic, the amount of adsorption to inorganic oxidants can be on the order of 10 mmol / m ² .

The oxidation potential of 3,4-ethylenedioxythiophene is low, and high-valent metal salts such as ferric salt can capture electrons on the thiophene ring and oxidatively polymerize the 3,4-ethylenedioxythiophene monomer. Ferric chloride, ferric sulfate, iron p-toluenesulfonic acid are readily available, and their anions have doping ability. The 3,4-ethylenedioxythiophene obtained by oxidation of 3,4-ethylenedioxythiophene The coating has good electrical conductivity. One or more of the above inorganic oxidizing agents may be selected according to market supply. A transparent uniform film having a surface resistance of less than 10 ⁴ Ω/□ can be prepared by adsorbing the trivalent iron salt oxidizing agent at 0.2 mmol/m ² or more. As the amount of oxidant adsorbed increased, the thickness of the obtained poly 3,4-ethylenedioxythiophene film increased, and the surface resistance and light transmittance of the composite film decreased. However, the amount of adsorption is too large, and the inorganic oxidizing agent is easily aggregated on the surface of the organic polymer to synthesize a non-uniform poly 3,4-ethylenedioxythiophene coating. The controlled adsorption amount is below 10 mmol/m ² , and the synthesized poly 3,4-ethylenedioxythiophene film is less likely to be spotted. The combination of multiple oxidants can reduce the tendency of the oxidant to agglomerate on the surface of the polymer substrate while increasing the total amount of oxidant adsorbed.

The invention converts the polymer on the surface of the substrate into an organic peroxide by high-energy radiation or chemical oxidation, and introduces an organic peroxide group as a second oxidant on the surface of the polymer substrate to further overcome the agglomeration of the inorganic oxidant. Increase the total amount of oxidant on the surface of the substrate.氙Excimer 172nm vacuum ultraviolet radiation, oxygen plasma can excite and split the polymer molecules on the surface of the substrate, react with oxygen or ozone, and introduce various peroxide groups on the surface of the polymer. Hydrogen peroxide immersion, peracid treatment, and ozone steaming can also oxidize the polymer to form hydrogen peroxide, peroxyether, ketone peroxide, and peroxyacid on the surface of the polymer, depending on the molecular structure of the polymer. The combination of high energy radiation treatment and chemical oxidation increases the surface peroxide content of the substrate to the order of 10 mmol/m ² . The peroxy group introduced on the surface of the polymer substrate is not highly oxidizing to the 3,4-ethylenedioxythiophene monomer. However, under the catalysis of oxidant ions or iron ions, the peroxy group is easily decomposed to generate hydroxyl radicals, and the oxidant ions are reduced from a low-valent state to a high-valent state, which further oxidizes the 3,4-ethylenedioxythiophene monomer. Increase the efficiency of the oxidant. The resulting hydroxyl radical also has a strong oxidizing power, which oxidizes the low-valent ion to the oxidation state. The peroxy group introduced on the surface of the polymer substrate can recycle the inorganic oxidizing agent to increase the oxidizing ability of the inorganic oxidizing agent.

Once the transparent polymer substrate with the composite oxidant film is immersed in the 3,4-ethylenedioxythiophene monomer solution, the inorganic oxidant attached to the surface of the substrate dissolves into the retention layer on the surface of the substrate, and 3, 4 in the oxidation retention layer. - The ethylenedioxythiophene monomer is polymerized, and the oxidant ion is reduced to a low-cost reduced state, losing the ability to oxidize 3,4-ethylenedioxythiophene. The organic peroxide group on the surface of the substrate is chemically bonded to the substrate, and the oxidation activity to 3,4-ethylenedioxythiophene is not high. However, the low-valent oxidant ions that lose oxidative activity in the retention layer can diffuse to the surface of the substrate, catalyze the decomposition of the peroxide group, and oxidize itself to a high-valent oxidation state. The regenerated oxidized ions further oxidize the 3,4-ethylenedioxythiophene monomer to increase the thickness of the synthetic conductive poly(3,4-ethylenedioxythiophene) and increase the surface conductance of the composite film. The oxidant ion diffusion has an isotropic property, and some of the reduced state ions in the retention layer will escape the retention layer. As the reaction time increases, the oxidant ion content in the retention layer decreases. When the adsorption amount of the inorganic oxidant is more than 0.2 mmol/m ² , there are enough reduced ions in the retention layer to catalyze the decomposition of peroxy groups on the surface of the substrate.

The solvent for diluting the 3,4-ethylenedioxythiophene monomer not only affects the solubility and oxidative polymerization rate of the 3,4-ethylenedioxythiophene monomer, but also affects the rate at which the adsorbed inorganic oxidant dissolves into the retention layer. The oxidizing agent has a large adsorption amount, has a high solubility in the solvent used, and is rapidly dissolved in the retention layer. The solvent can be selected from petroleum ether, hexane, heptane, cyclohexane, benzene, toluene, dichloromethane, chloroform, acetonitrile, butyl acetate, methyl ethyl ketone or butanol or a mixed solvent can be prepared to control the dissolution of the oxidant into the retention layer. The matching of the speed and the oxidation consumption speed prevents the high-valent oxidation state ions from diffusing out of the retention layer, ensuring that the oxidative polymerization occurs in the retention layer, thereby ensuring the effective utilization of the raw materials. By adjusting the adsorption amount of the inorganic oxidant and the content of the organic peroxide group, a solvent of 20-400 mmol/L of 3,4-ethylenedioxythiophene monomer is prepared by using a solvent, and the reaction is carried out at 0-60 ° C for 0.2-12 hours. Synthetic conductive poly(3,4-ethylenedioxythiophene) coating, which is washed with dilute sulfuric acid to remove residual oxidant ions, and can produce flexible transparent conductive with surface resistance lower than 10 ² Ω/□ and transmittance higher than 80%. membrane.

 In summary, the present invention has the following advantages and technical effects as compared with the prior art: the present invention overcomes the poly 3,4- Ethylene dioxythiophene is difficult to form into a film, and it is difficult to produce a large-area, high-quality conductive film.

 The problem of ITO flexible transparent conductive film. In situ synthesis of a transparent conductive poly(3,4-ethylenedioxythiophene) coating on the surface of a transparent polymer substrate, Surface resistance and complex of the obtained poly 3,4-ethylenedioxythiophene coating

 The transmittance of the film at 550 nm can vary from 82% to 92%, and the surface resistance of the composite film can range from 80 to 600 Ω/□. Variety.

detailed description

The following is a further description of the present invention in conjunction with the examples, but the present invention is not limited to the following examples. The following examples are based on the present invention and further refined, and the process parameters which are not specifically described may be referred to conventional techniques.

 Implementation example 1

The transparent polyimide film was immersed in a 10% NaOH solution for 15 minutes, taken out, neutralized with dilute hydrochloric acid, rinsed with distilled water, and dried with nitrogen. The surface treated polyimide film was immersed in a 5.0% H ₂ O ₂ solution for 10 minutes, taken out and dried at 40 ° C, and a 2.1 mmol/m ² peroxy group was introduced, followed by immersion in a 70 mmol/L FeCl ₃ ethanol solution. After soaking for 3 minutes, take off and dry, and adsorb 1.5 mmol/m ² of FeCl ₃ . The polyimide film composite with an oxidizing agent in the film is suspended 70 mmol / L of 3,4-ethylene dioxythiophene toluene solution was allowed to stand at 25 ^o C for 10 hours. After taking out, it was rinsed with 0.3 M of dilute sulfuric acid, washed with deionized water and absolute ethanol, and dried with nitrogen to obtain a pale blue transparent PI/PEDOT composite film .

 Implementation example 2

The transparent polyimide film (PI) was immersed in a 10% NaOH solution for 15 minutes, taken out, neutralized with dilute hydrochloric acid, rinsed with distilled water, and dried with nitrogen. The surface treated polyimide film was immersed in a 5.0% peracetic acid solution for 10 minutes, taken out and dried at 40 ° C, and a 2.8 mmol/m ² peroxy group was introduced, followed by immersion in a 70 mmol/L FeCl ₃ ethanol solution. After soaking for 3 minutes, it was taken out and adsorbed 1.5 mmol/m ² of FeCl ₃ . After the solvent was evaporated, the polyimide film with FeCl ₃ oxidant was suspended from 70 mmol/L of 3,4-ethylenedioxythiophene. dioxane solution was allowed to stand at 25 ^o C for 10 hours. After taking out, it was rinsed with 0.3 M of dilute sulfuric acid, washed with deionized water and absolute ethanol, and dried with nitrogen to obtain a pale blue transparent PI/PEDOT composite film .

 Implementation example 3

The polyethylene terephthalate film was immersed in tetrahydrofuran, rinsed with distilled water, and blown dry with nitrogen. The polyethylene terephthalate film was irradiated with a 172 nm vacuum ultraviolet light source with a radiation output of 8 mW/cm ² in air to control the distance between the light window and the polyethylene terephthalate film. Mm, irradiation time 4 minutes. Immediately after the irradiation, the exposed polyethylene terephthalate film was immersed in a solution of 80 mmol/L of iron butanol p-toluenesulfonate for 10 minutes, and then taken out to dryness to adsorb 2.2 mmol/m ² of Fe(TsO) _{3 .} Oxidizer. With an oxidizing agent to the polyethylene terephthalate film is suspended in 80 mmol / L of 3,4-ethylene dioxythiophene in cyclohexane solution was allowed to stand at 25 ^o C for 10 hours. After taking out, it was rinsed with 0.3 M of dilute sulfuric acid, washed with deionized water and absolute ethanol, and dried with nitrogen to obtain a pale blue transparent PET/PEDOT composite film .

 Implementation example 4

The polyethylene terephthalate film was immersed in tetrahydrofuran, rinsed with ethanol, and blown dry with nitrogen. The polyethylene terephthalate film was irradiated with a 172 nm vacuum ultraviolet light source with a radiation output of 8 mW/cm ² in air to control the distance between the light window and the polyethylene terephthalate film. Mm, irradiation time 4 minutes. Immediately after the irradiation, the exposed polyethylene terephthalate film was immersed in a 3% peracetic acid solution for 10 minutes, a 1.5 mmol/m ² peroxy group was introduced, and then immersed in 80 mmol/L of p-toluenesulfonic acid. After 10 minutes, the iron butanol solution was taken out and dried, and 1.9 mmol/m ² of Fe(TsO) ₃ oxidant was adsorbed. The oxidant with the polyethylene terephthalate film is suspended in 80 mmol / L of 3,4-ethylene dioxythiophene in cyclohexane solution was allowed to stand at 30 ^o C 4 hours. After taking out, it was rinsed with 0.3 M of dilute sulfuric acid, washed with deionized water and absolute ethanol, and dried with nitrogen to obtain a pale blue transparent PET/PEDOT composite film .

 Implementation example 5

The cycloolefin polymer membrane was soaked in toluene, rinsed with ethanol, and blown dry with nitrogen. The cycloolefin polymer film was irradiated with a 172 nm vacuum ultraviolet light source having a radiation output of 8 mW/cm ² in air, and the distance between the light window and the cycloolefin polymer film was controlled to be 2 mm, and the irradiation time was 4 minutes. Immediately after the irradiation, the exposed cycloolefin polymer film was immersed in a 3% peracetic acid solution for 10 minutes, a peroxy group of 0.8 mmol/m ² was introduced, and then immersed in a solution of 80 mmol/L of iron butanol p-toluenesulfonate 10 After a minute, it was taken out and dried, and a Fe (TsO) ₃ oxidizing agent of 1.8 mmol/m ^{2 was} adsorbed. The compound with the oxidizing agent cycloolefin polymer film suspended in 80 mmol / L of 3,4-ethylene dioxythiophene in cyclohexane solution was allowed to stand at 30 ^o C 4 hours. After taking out, it was rinsed with 0.3 M of dilute sulfuric acid, washed with deionized water and absolute ethanol, and dried with nitrogen to obtain a pale blue transparent COC/PEDOT composite film .

 The surface resistance and the complex of the poly 3,4-ethylenedioxythiophene coating obtained in the examples were measured by a four-probe resistance tester. The light transmittance of the film at 550 nm was obtained, and the results are shown in Table 1. The surface resistance of the composite film can vary from 80 to 600 Ω/□ and the light transmittance can vary from 82 to 92%.

 Table 1 Surface resistance and light transmittance of liquid phase precipitation polymerization PEDOT composite film

Project	unit	Example 1	Example 2	Example 3	Example 4	Example 5
Transparent substrate		PI	PI	PET	PET	COC
Water solution	Min	15	15	---	15	---
VUV radiation	Min	---	---	4	4	4
H 2 O 2 soak	[c]×min	5%×10	---	---	---	---
CH 3 COOOH	[c] ×min	---	3%×10	---	3%×10	3%×10
Oxidant concentration	Mmmol/L	FeCl 3 70	FeCl 3 70	Fe(TsO) 3 80	Fe(TsO) 3 80	Fe(TsO) 3 70
Adsorption time	Min	3	3	10	10	10
Monomer concentration	Mmmol/L	70	70	80	80	80
Reaction time	Hrs	10	10	10	4	4
Peroxyl content	Mmmol/m 2	2.1	2.8	---	1.5	0.8
Total oxidant	Mmmol/m 2	3.6	4.3	2.2	3.4	2.6
Surface resistance	Ω/□	600	220	140	80	400
Transmittance @ 550nm	%	90	86	84	82	92

Claims (10)

1. A method for fabricating a flexible transparent conductive composite film, characterized in that a transparent polymer film coated with an oxidizing agent film is immersed in a 3,4-ethylenedioxythiophene monomer solution, and 3,4-B is carried out on the surface of the polymer film. The chemical oxidative polymerization of the dioxythiophene monomer is carried out to synthesize a conductive poly(3,4-ethylenedioxythiophene) in situ to obtain a flexible transparent conductive composite film.
2. The method for fabricating a flexible transparent conductive composite film according to claim 1, wherein the oxidant continuously oxidizes and diffuses to the surface of the transparent polymer to polymerize the 3,4-ethylenedioxythiophene monomer during the preparation process. A transparent conductive poly 3,4-ethylenedioxythiophene coating is formed.
3. The method for fabricating a flexible transparent conductive composite film according to claim 1, wherein the oxidizing agent film is an inorganic oxidizing agent or a composite of an inorganic oxidizing agent and an organic peroxide; and the inorganic oxidizing agent is a physically adsorbed inorganic oxidizing agent; The organic peroxide is an organic peroxide that is chemically converted on the surface.
4. The method for fabricating a flexible transparent conductive composite film according to claim 3, wherein the inorganic oxidizing agent is a ferric salt; the trivalent iron salt is ferric chloride, ferric sulfate and p-methylbenzene. One or more kinds of iron sulfonate; the inorganic oxidizing agent has an adsorption amount of 0.2 to 10 mmol/m ² on the transparent polymer substrate.
5. The method for fabricating a flexible transparent conductive composite film according to claim 3, wherein the surface is chemically converted into hydrogen peroxide, peracid oxidation, ozone oxidation, vacuum ultraviolet photochemical oxidation, and oxygen plasma bombardment. More than one.
6. The method for fabricating a flexible transparent conductive composite film according to claim 3, wherein the organic peroxide is one or more of hydrogen peroxide, peroxyether, ketone peroxide and peroxyacid; The concentration of the organic peroxide on the surface of the transparent polymer substrate is from 0 to 10 mmol/m ² .
7. The method for fabricating a flexible transparent conductive composite film according to claim 1, wherein the concentration of the 3,4-ethylenedioxythiophene monomer solution is 20-400 mmol/L; the solvent of the solution is One or more of petroleum ether, hexane, heptane, cyclohexane, benzene, toluene, dichloromethane, chloroform, acetonitrile, butyl acetate, methyl ethyl ketone or butanol.
8. The method for fabricating a flexible transparent conductive composite film according to claim 3, wherein the oxidative polymerization is carried out at 0-60 ° C, and the reaction time is 0.02-12 hours, and the obtained poly 3,4-ethylenedioxygen is obtained. The thiophene coating is washed with 0.1 to 0.5 M of dilute sulfuric acid.
9. The method for fabricating a flexible transparent conductive composite film according to claim 3, wherein the substrate of the transparent polymer film comprises polymethyl methacrylate, polycarbonate, and polyethylene terephthalate. Ester, polyethylene naphthalate, cycloolefin polymer, polyimide, cured epoxy or silicone resin.
10. The method for fabricating a flexible transparent conductive composite film according to claim 1, wherein the transparent polymer film is surface-treated to form an oxidizing agent layer; the surface treatment comprises chemical modification, high-energy radiation modification, and surface treatment. Treatment with an active agent; the surface is chemically modified to be hydrolyzed or sulfonated, specifically with 10% aqueous NaOH or 30% The H2SO4 aqueous solution is immersed for 10-45 minutes; the high-energy radiation treatment is 172 nm vacuum ultraviolet photochemical oxidation or oxygen plasma treatment.