KR100422321B1 - Transparent Anti-static Polyester Films - Google Patents

Abstract

The present invention relates to an antistatic polyester film that exhibits transparency of up to 90% or more in the visible region, and more particularly, to a mixed solution of a conductive polymer monomer, an oxidizing agent, a dopant, and the like is coated on a polyester surface. By directly synthesizing a conductive polymer film on a polyester film to produce a transparent antistatic polyester film relates to a method for enhancing the adhesion and surface hardness of the coated conductive film and to the invention of the polyester film prepared using the same.

Using the techniques of the present invention when the surface resistivity is 10 ¹⁰ ohm / □ (ohms / square) from 10 ² ohms / □ adjustment is possible, while the transmittance at 550 nm up to less than 90%, the adhesive force by the ASTM D3359 method by It is this 5B and the transparent antistatic polyester film which is 2H or more in surface pencil hardness by the ASTM D3363-92a method can be manufactured.

Description

Transparent Anti-static Polyester Film {Transparent Anti-static Polyester Films}

The present invention relates to a coating technology of a transparent antistatic polyester film and a transparent antistatic pulley film using the same.

In the present invention, the polyester film refers to a polymer film having an ester functional group such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT) film.

With the recent development of industrialization, the damage caused by the generation of static electricity has increased in many fields, including various electronic and electric devices, information and communication fields, medical fields, and general household goods. It is emerging. Antistatic refers to discharging the charge accumulated on the surface of the insulator by an appropriate method, and to prevent the charge, a conductive film capable of discharging the charge accumulated on the surface of the product may be formed.

Antistatic technologies for polymer products include roughly (1) plating, (2) conductive powder mixing, and (3) using conductive polymers. Plating method is a method of soaking the product in the plating solution containing metal so that the metal layer is coated on the surface of the product. This method is detrimental to the physical and chemical properties of the product because the plating solution is harmful to the human body and it is difficult to completely remove the remaining plating solution after plating. There is this. Conductive powder mixing method is a method of making a product by mixing the fine conductive powder to the raw material of the product to make a mixture. However, in order to make the product conductive, the content of the metal powder should be higher than the critical value. At this time, the mechanical properties of the polymer are greatly degraded and the fluidity is poor, which causes a great problem in forming the product. In particular, it is not applicable to the product which requires transparency. In contrast, the method using the conductive polymer may simultaneously impart transparency and conductivity according to the content of the conductive polymer.

The problem of imparting antistatic properties to the packaging of precision parts such as semiconductor chips and polyester films applied to various industries is an important problem to be solved urgently throughout the industry including the semiconductor, telecommunications and medical fields.

The development of an antistatic polyester film with transparency is not solved by the above-mentioned plating method or conductive powder mixing method. Some have used a method of dissolving a surfactant in a suitable solvent and then coating it on a polyester surface or using a mixture of surfactant and polymer.

The reason why the surfactant is conductive is that it combines with moisture in the atmosphere to show conductivity. However, the conductivity of the surfactant is limited, so that surface resistance of approximately 10 ⁹ Ω / □ or less cannot be obtained. When the moisture content of the surfactant is low, the antistatic property is greatly reduced, and the solvent resistance is very bad. Due to the disadvantage that the surfactant powder on the surface of the film impurity particles adversely affect the quality of the product or there is a risk of dust generation, the application is greatly limited.

In addition, a mixture of conductive carbon black and polymer resin may be used, or a method of coating carbon black on the surface of the polymer may be used. It is used in products such as carrier tape or antistatic tray for transporting semiconductor chips. This method is also inconvenient because the color is black and especially conductive carbon black may be smeared out or conductive dust may be generated. . Therefore, there is an urgent need to develop a new transparent antistatic polyester film of non-carbon black and non-surfactant type that can compensate for these disadvantages.

As conductive polymers such as polyaniline, polypyrrole or polythiophene dissolved in water organic solvents have been developed, many research studies have been conducted to impart conductivity to antistatic polyester films or other polymer surfaces. ought. A common method is to make a conductive polymer that is doped and then coat it on the surface of the polymer, including polyester, in a suitable solvent. In this case, the appropriate binder may be dissolved together to improve mechanical properties such as adhesion or surface hardness of the coating layer.

However, in order to increase the solubility and conductivity, the synthesized conductive polymer should be dissolved in toxic organic solvents such as metacresol and chloroform, and then coated and dried on the surface of the polymer including polyester. During this process, when the organic solvent is volatilized and the working environment is poor, the use of the organic solvent is limited. In order to compensate for this disadvantage, in the case of polling aniline, a conductive polymer may be synthesized using an aniline derivative (for example, ethoxy aniline) that can be dissolved in an alcohol solvent.

In the case of using such an aniline derivative, the synthesized conductive polymer increases solubility, whereas the electrical conductivity of the synthesized conductive polymer decreases, thereby limiting the conductivity of the conductive polymer having low resistance and good transparency.

In Bayer, conventionally, 3,4-ethylenedioxythiophene, a kind of conductive polymer monomer, and ferric toluene sulfonate (Iron (III) p-toluenesulfonate), which are synthesized from them, 3,4-polyethylenedioxythiophene, a conductive polymer, was developed (US Pat. No. 4,959,430). 3,4-ethylenedioxythiophene and ferrictoluenesulfonate were mixed at room temperature and then heated. 3,4-polyethylenedioxythiophene, a blue conductive polymer, was prepared.

Synthesized 3,4-polyethylenedioxythiophene is also commercially available in the form of dispersed in water, but if the mixture is left for a long time at room temperature by mixing 3,4-ethylenedioxythiophene and ferric toluenesulfonate may cause polymerization reaction In order to prevent this, a small amount of a reaction inhibitor imidazole may be mixed. Oxidizing agents such as conductive polymer monomers such as 3,4-ethylenedioxythiophene and ferrictoluenesulfonate, and alcohol solvents such as ethyl alcohol, butyl alcohol, butanol, isopropyl alcohol and acetone Because it is soluble in, there is little problem of working environment by smell or toxicity during coating work.

Bayer's patent on imparting conductivity to polymer surfaces using 3,4-ethylenedioxythiophene and ferrictoluenesulfonate (US Pat. No. 4,987,042, US Pat. No. 5,035,926) discloses these compounds either directly or in polyvinylacetate After mixing an appropriate amount with a binder such as polyvinyl acetate or polyvinyl alcohol, the mixture is mixed with a polycarbonate film, a polyvinyl chloride film, a polyester film, and a polyamide. When coated on a polymer surface such as a film and heated, the surface resistance can be as low as several hundred ohms / square.

Similar methods have been introduced (US Pat. Nos. 5,447,824 and 5,705,888), but the methods described in these documents mix 3,4-ethylenedioxythiophene and ferrictoluenesulfonate with imidazole and coat them on a polymer surface, followed by heat drying. To directly synthesize the conductive polymer film on the polyester film.

However, the conductive polymer film made by such a method has a disadvantage in that the coated conductive polymer film is completely peeled off when the hand polymer or the fingernail is scratched when the adhesiveness with the base polymer is bad.

According to the patent, it is mixed with a binder such as polyvinyl acetate, polyvinyl alcohol and the like and coated on the base polymer film. However, when 3,4-ethylenedioxythiophene is used to directly synthesize the conductive polymer film on the surface of the polyester film, when the binder is used simultaneously with the conductive monomer and the oxidizing agent, the binder interferes with the synthesis of the conductive polymer and thus the uniform Interfere with formation and cannot form a stable conductive polymer layer. In addition, when synthesizing with the binder, the binder should use a solvent capable of dissolving the conductive monomer and the oxidizing agent.

In this case, after the coating and synthesis is completed, the binder is dissolved and the synthesized coating layer is peeled off during the process of washing the unreacted monomer and the excess oxidant. When the binder is not used to compensate for these disadvantages, the conductive polymer layer is pulled off by hand when the conductive polymer layer synthesized on the polyester surface is pushed by hand.

Therefore, when 3,4-ethylenedioxythiophene is directly synthesized on the polyester surface using 3,4-ethylenedioxythiophene, a new method must be used instead of the conventional method. Polymer products such as polyester coated with the conductive polymer film prepared by the above method are expected to be very useful commercially as long as it improves the adhesion between the conductive polymer film and the base polymer and increases the surface pencil hardness.

The present invention is synthesized by coating the mixture solution of 3,4-ethylenedioxythiophene and ferric toluene sulfonate on a substrate such as polyester to synthesize a 3,4-polyethylenedioxythiophene film directly on the polyester film surface. An object of the present invention is to provide a coating solution and a coating method capable of increasing the adhesion between the conductive polymer film and the base polymer and the surface pencil hardness, and a transparent antistatic polyester film using the same.

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

The general method of conductive polymer synthesis depends on the type of conductive polymer. In the case of 3,4-ethylenedioxythiophene and ferrictoluene sulfonate mainly used in the present invention, when 3,4-ethylenedioxythiophene is dissolved in a solvent and ferrictoluenesulfonate is added thereto, 3,4-polyethylenedioxane Citofene is synthesized. At this time, if the temperature is heated, the synthesis reaction is accelerated, and the synthesis is completed within 1 or 2 minutes at 100 ° C. or higher. Bayer sells 3,4-polyethylenedioxy thiophene in which the product is dispersed in water. This product can be coated on a substrate such as glass and heat-dried to coat a conductive film on the glass substrate.

However, since these products are water-dispersible conductive polymers, coating them directly on a polyester film does not match the solvent system, and thus, a conductive polymer membrane having good adhesion to the base polymer and good surface pencil hardness cannot be obtained.

In the method of synthesizing conductive polymers used in the present invention, as the conventional patent, 3,4-ethylenedioxythiophene, a monomer, and ferrictoluenesulfonate, an oxidizing agent, are used at a predetermined ratio of ethyl alcohol, butyl alcohol, isopropyl alcohol, acetone. Dissolve in a solvent such as to make a solution.

When the solution was coated on a substrate surface such as polyester and then heated again in a thermocycle or vacuum oven, a method of directly synthesizing a 3,4-polyethylenedioxythiophene membrane as a conductive polymer on the substrate surface was used.

In order to prepare an antistatic polyester film using the above method, it is necessary to overcome various difficulties. It is important to improve the adhesion and the surface pencil hardness of the conductive polymer film formed on the polyester surface.

Common methods for improving adhesion include a method of introducing a polar group to the surface of the substrate by treating the surface of the substrate such as polyester with a corona or ion beam, or coating an acrylic resin or the like on the surface of the polyester film. Here, the corona or ion beam treatment technology increases the adhesion of the polyester surface, but has a disadvantage in that the adhesion decreases with time due to a complex action with surrounding moisture.

Therefore, polyester resin coated with acrylic resin should be used or desired resin should be coated on polyester. In addition, 3,4-ethylene dioxythiophene and ferrictoluenesulfonate mixtures have a fast synthesis reaction, and the reaction is almost completed within 1-2 minutes at a high temperature of 100 ° C or higher, so that the adhesive strength within the resin-coated polyester resin is within this time. Enhancement reactions should be made. A binding aid may be used for this purpose, but the compatibility with the solvent system used should be good, and crystallization should not occur after the solvent is removed.

After the synthesis is completed, the hardness of the coated conductive polymer film is a very important problem in the use of the transparent antistatic polyester film. To measure the surface hardness, scrape the polyester surface with a pencil (pencil hardness test: ASTM D3363-92a) or scrape with steel wool. In general, the method of improving the surface hardness is mainly used a method of hard coating on the surface of the adherend such as polyester. After applying a compound consisting of alkoxy silicate (alkoxy silicate) on the surface of the polymer and UV or heat-cured to form a silica layer (silica) can be coated with a high pencil hardness layer on the surface of the polymer.

In this case, the acetate-based curing agent is used together, and the curing temperature and the curing time are determined according to the content ratio of the curing agent and the alkoxy silicate. In general, as the content of the curing agent increases, the curing time is shortened, but the surface pencil hardness is lowered.

In addition, in order to complete the hard coating in a short time, the curing temperature must be high, but when the curing temperature is high, there is a disadvantage that it cannot be used in the case of the polymer deformation occurs at that temperature.

In order to solve the above problems, the present invention uses the following method.

First, in order to improve the adhesion between the synthesized 3,4-polyethylenedioxythiophene and the polyester film as the base polymer, (1) using a polyester film coated with an acrylic resin, or (2) a non-coated polyester film In the case, the primer was first treated with a primer capable of imparting adhesion to the polyester surface.

Polyester resin coated with acrylic resin is a commonly used method, commercially available and used as it is (eg Saehan Co., Ltd., XG532, acrylic coated polyester film). In addition, an epoxy resin was coated on the surface of the non-coated general polyester resin and then cured to give an adhesive property to the non-coated polyester film. The 3,4-ethylenedioxythiophene and ferrictoluenesulfonate mixed solution was coated on the surface of the polyester film thus treated, and then heated again to form a 3,4-polyethylene dioxythiophene film on the surface of the polyester film.

The epoxy resin mainly used in the present invention can mix 20-80 parts by weight of an amine curing agent when the weight of the epoxy resin is 100 as the bisphenol epoxy and the amine curing agent. However, the epoxy resin, the curing agent and the solvent which can be used in the present invention are not limited to the system used in the present invention, but any epoxy that can be coated on the polyester surface can be used, and the mixing ratio of the epoxy and the curing agent and the solvent are mixed. The content of epoxy and curing agent, ie the content of solids, is not limited to any certain content.

In addition, the solvent is not limited to acetone, and any solvent that does not generate a solid precipitate when the epoxy and the curing agent are mixed can be used. However, the curing temperature and curing time may be adjusted according to the type of solvent, the ratio of epoxy and curing agent, and the solid content in the solvent. The same effect can be obtained by using co-solvent when necessary in preparing a coating solution in which an epoxy and a curing agent are mixed.

The thickness of the epoxy resin coated on the polyester film is suitably 0.1-5.0 microns thick. If the thickness of the coated epoxy resin is too thin, coating is difficult, and if the thickness of the epoxy resin layer is too thick, the polyester film used is distorted.

In addition, when the conductive polymer is synthesized after coating an epoxy resin containing a curing agent on a polyester film, the curing degree of the epoxy layer should be at least 50% or more. If the epoxy resin is uncured, it prevents the formation of the 3,4-polyethylenedioxythiophene film from 3,4-ethylenedioxythiophene and ferric toluenesulfonate and thus has no conductivity.

3,4-ethylene dioxythiophene and ferrictoluenesulfonate mixed solution was coated on the polyester film coated with acrylic resin, and then heated at 50-150 ° C. for 30 seconds to 5 minutes to form 3,4-polyethylene on the polyester film. A deoxythiophene membrane is synthesized. The surface resistance of the antistatic polyester film thus prepared was measured to be 2 × 10 ³ ohms / square.

However, the coated conductive polymer layer is weak enough to be easily pushed by hand, and thus the surface hardness is very bad. This means that unless otherwise prescribed, there is no adhesion between the acrylic layer coated on the polyester surface and the synthesized 3,4-polyethylenedioxythiophene and cannot be used.

The increased adhesion between the acrylic layer coated on the polyester surface and the synthesized 3,4-polyethylenedioxythiophene membrane can significantly improve adhesion and surface hardness by adding a certain amount of alkyl trialkoxysilicate, which is used as a conventional adhesion promoter. Can be. Representative alkyl groups here are trimethacryloxypropyl, vinyl and the like, and most silicates such as silicates, acrylic silicates, and epoxy silicates used as organic-inorganic coupling agents have the same performance.

In addition, the silicate content used in the present invention was evaluated 1-30 parts by weight to confirm the increase in adhesion at these parts by weight, but the same effect can be expected in other contents.

However, if the content is too small, the effect is insignificant, and if the content is too high, silicates other than the content used to promote adhesion may rather adversely affect the surface hardness. The maximum adhesion was found when the silicate content was 5-10 parts by weight, depending on the type of silicate. At this time, the adhesive force is 5B.

In applying the above technique, an acrylic resin-coated polyester film to which alkyl trialkoxysilicate is added may be used, or alkyl trialkoxysilicate may be substituted with 3,4-ethylenedioxythiophene, ferrictoluenesulfonate, imidazole, solvent, and the like. It can be used in addition to the mixture, in which case both can have the same effect. The epoxy resin coating method is not applicable to the case of a polyester film that is deformed at a high temperature because the curing of the epoxy resin should be made at a relatively high temperature.

For example, amorphous polyester film (A-PET film) is opaque due to crystallization at a temperature of about 120 ℃ Celsius, N, N- dimethylformamide and N-methyl- It is a polyester film characterized by being opaque when contacted with an organic solvent such as 2-pyrrolidinone (N-Methyl-2-pyrrolidinone). Such polyester film is impossible to the above-mentioned epoxy resin coating treatment. In this case, the problem may be solved by coating the acrylic polyol-based polymer. In the case of the amorphous polyester film, the acrylic polyol is coated on the surface of the film, the solvent is removed by air at about 40 ° C, and then 3,4-ethylenedioxythiophene, peryltoluenesulfonate, and imidazole mixed solution are coated on the film. When left at a temperature of about 50-80 ° C. for several minutes, a conductive polymer 3,4-ethylenedioxythiophene layer is formed.

The conductive polymer layer prepared in this manner has an adhesive strength of 5B and a surface pencil hardness of 2H or more. At this time, in addition to the acrylic polyol, a polyester polyol, a urethane-based polymer cured with an acrylic polyol and an isocyanate mixture, and the like have the same effect.

The antistatic polyester film prepared by the above method has a surface resistance of up to 10 ² ohms / square, shows an adhesive force of 5B in the scotch tape adhesion test, and shows a pencil hardness of 2H or higher as a result of the surface hardness measurement.

Additives such as antioxidants, UV stabilizers and blockers, surfactants, viscosity modifiers, etc. may be added to enhance the functionality of the polyester film surface with 3,4-polyethylenedioxythiophene membrane prepared by the above method and to improve the efficiency of coating. have.

Antioxidants are hindered phenolic compounds substituted with alkyl, aryl groups with or without phosphorus, sulfur and are likely to occur during heat treatment to form 3,4-polyethylenedioxythiophene membranes and during product use. It is used for the purpose of suppressing thermal degradation. UV stabilizers are hindered amine compounds substituted with alkyl or aryl groups and sunscreens are benzotriazole compounds substituted with alkyl or aryl groups and can be used to suppress the possibility of conductivity changes by ultraviolet light in the environment during product use. have. The surfactants are acrylic, fluorine, silicone positive, negative or nonionic compounds. For smooth coating, the viscosity of the coating solution needs to be adjusted. As the diluent, acetone, methanol, ethanol, isopropyl alcohol, normal butanol, cyclohexane, It is a mixed organic solvent such as methyl ethyl ketone, methyl isopropyl ketone, xylene, toluene, etc. The thickener can add additives such as cellulose ether, starch, silica organic compounds, polyacrylate, polyurethane polymer resin, etc. have.

The polymer film capable of producing a transparent antistatic polyester film using the above technique may be a polyester-based polymer having an ester functional group such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT) film, and the like. Film made of modified polyester made of a copolymer for improving adhesion. The above technology can be applied to all products requiring antistatic properties such as plates, molded articles, as well as films.

The present invention mainly uses polythiophene using 3,4-ethylenedioxythiophene as a monomer of a conductive polymer and ferrictoluenesulfonate as an oxidizing agent, but the same method can be applied to the synthesis of polythiophene using another thiophene derivative. Can be. In addition, a conductive polymer such as polyaniline or polypyrrole may also form a conductive film on the polyester film by direct synthesis by the same method. In the case of polyaniline, the reaction between the aniline and the oxidant is fast, so the content of the reaction delay agent should be increased. Likewise, in the case of polypyrrole, the same effect can be obtained by adjusting the content of the reaction delay agent.

In general, the solvent resistance of the antistatic film is determined by dropping isopropyl alcohol or acetone on the film and then changing the conductivity or the presence of stain after the solvent evaporates.

A drop of isopropyl alcohol is dropped on the transparent antistatic polyester film prepared by the above technique, and a light trace is left after evaporation. However, if the trace is removed with a soft cloth, it is wiped clean and the surface resistance of this part is not much different from the initial value. Therefore, it can be judged that the solvent resistance of the transparent antistatic polyester film produced by the above technique is good.

However, in some cases, the surface of the transparent antistatic film may be wiped with a solvent such as alcohol or acetone, in which case there may be a problem that the conductive polymer layer is removed even in the antistatic film prepared by the above technique. This problem is also found in other conductive polymers using binders.

In order to solve this problem, the present invention used a method of protective coating on the 3,4-polyethylenedioxythiophene layer formed on the surface of the polyester film. When the protective layer is formed on the conductive polymer layer, the surface resistance of the film is inevitably increased, and the conductive polymer layer should be protected from the solvent while minimizing the increase in the surface resistance. To meet these requirements, thermoset protective layer materials should be used. When the thermoplastic protective layer material is used, solvent resistance is inevitably low.

The present invention used a method of mixing the acrylic polyol and isocyanate in an equivalent ratio and thermosetting at a constant temperature to make a urethane-based thermosetting protective layer. The thickness of the protective layer is an important factor in determining the increase of the surface resistance, and the thickness of the protective layer can be adjusted as the concentration of the acrylic polyol and diisocyanate dissolved in the solvent. That is, if the content of high acrylic polyol and diisocyanate is high, the coating thickness is likely to be high, so the coating thickness should be thin or the content of acrylic polyol and diisocyanate should be low. It shows the best properties when the content of acrylic polyol and isocyanate in the solvent is 2-30 parts by weight.

If the acrylic polyol and isocyanate content is lower than 2 parts by weight, the protective layer is too thin to act as a protective layer. If the acrylic polyol and isocyanate content is higher than 30 parts by weight, the protective layer is too thick and the surface resistance is too high. It cannot be used because there is a possibility that the antistatic property decreases due to a high increase.

In addition to the acrylic polyol and isocyanate mixtures, various kinds of silicate compounds can also be used as the protective layer. The silicate has the advantage that the surface protective layer is not peeled off even when wiped with a solvent of ethyl alcohol, isopyrophyll alcohol, or isetone because the surface hardness of the protective layer is very high and the solvent resistance is very high when the curing agent is mixed and used. The coating technique of the protective layer is largely a thermosetting method and an ultraviolet curing method, both of which are useful for forming a surface protective layer. When selecting a thermosetting method, it should be cured at a temperature such that the dimensions of the polyester film, the base polymer during thermal curing, are not deformed.

In particular, in the case of the amorphous polyester film, the thermal stability is inferior to that of the general polyester film, so the thermosetting temperature should not be increased. When choosing the UV curing method, UV curing time should be as short as possible. Since conductive polymers are conjugated double bonds in structure, they have a strong tendency to decrease conductivity as the nucleus double bonds collapse after prolonged exposure to ultraviolet rays. Therefore, when the protective layer is coated using the ultraviolet curing method, the exposure time to ultraviolet rays should be kept as short as possible to suppress the collapse of the nucleophilic double bond as much as possible. In this case, when the UV stabilizer is mixed with the mixture of the conductive polymer monomer and the oxidizing agent or the UV stabilizer is mixed with the coating liquid for the protective layer, the collapse of the conductive polymer may be suppressed during UV curing.

In the case of the transparent antistatic polyester film coated with the protective coating layer by the above technology, the conductive layer is excellent in solvent resistance and does not peel off even when washed with an alcohol or acetone solvent.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, these Examples and Comparative Examples do not limit the scope of the present invention.

<Example 1>

100 parts by weight of the bisphenol epoxy and 40 parts by weight of the amine curing agent were dissolved in acetone to adjust the content of the epoxy and the curing agent to 20%, and then the solution was coated on the uncoated polyester film to a thickness of 1 micron.

The film was cured for 20 minutes in a 120 degree Celsius heat circulation oven to prepare an epoxy coated polyester film. Curing degree at this time is about 70%. The film was coated with a solution of 3.5 mmol of 3,4-ethylenedioxythiophene, 8.1 mmol of ferric toluenesulfonate, and 2.3 mmol of imidazole in 15 grams of acetone to a thickness of 1.5 microns, followed by 2 minutes in a thermocycle oven at 100 degrees Celsius. To induce the reaction. After the reaction was completed, the film was taken out, washed with ethyl alcohol and dried to prepare a transparent antistatic polyester film.

The surface resistance of the antistatic film prepared as described above has a property of 2 × 10 ³ ohms / square, adhesiveness of 5B, pencil hardness of 3H, and transparency of 75%. This property is antistatic prepared by a method of forming a 3,4-polyethylenedioxy thiophene film without any treatment of the non-coated polyester film of Comparative Example 1 or using a polymer as a binder as in Comparative Example 2-4 It was much superior to surface properties such as adhesiveness and surface pencil hardness of the polyester film.

In addition, it can be seen that the surface properties of the antistatic polyester film prepared by the method of synthesizing the 3,4-polyethylenedioxythiophene film without any treatment on the polyester film coated with the acrylic resin of Comparative Example 5.

<Example 2>

When 3.5 mmol of 3,4-ethylenedioxythiophene, 8.1 mmol of ferrictoluenesulfonate and 2.3 mmol of imidazole were mixed in 15 grams of acetone, except that three surfactants were mixed in an amount of 0.1-20 parts by weight based on the solids content. A transparent antistatic polyester film was prepared in the same manner as in Example 1.

The surface characteristics of the antistatic polyester film having the 3,4-polyethylenedioxythiophene film prepared by the above technique are summarized in Table 1. As shown in Table 1, when the surfactant is added, the surface resistance and adhesion are similar to those of Example 1, while the surface lubricity is greatly increased. The effect of the surfactant content is 5-10 parts by weight regardless of the type of surfactant is the best properties, while if the surfactant content is too high (for example 20 parts by weight) surface slippage is too Severe surfactant was found on the hands.

Table 1.Surface Properties by Surfactant Type and Content

Content (parts by weight) Surface resistance (Ω / □) Transparency (%) ¹ Adhesion ² Surface Hardness ³ Surface Lubrication ⁴ FC430 ⁵ 0.10.51.05.01020 10 ³ 75-80 5B 1 H1 H1 H2 H2 H2 H Bad Bad Good Good Bad KP322 ⁶ 0.10.51.05.01020 10 ³ 75-80 5B 1 H1 H2 H3 H3 H3 H Good Bad Good Good Bad BYK358 ⁷ 0.10.51.05.01020 10 ³ 75-80 5B 1 H1 H1 H2 H2 H2 H Good Bad Good Good Good Good Good

¹ : transmittance at 550 nm, ² : ASTM D3359 test method,

³ : ASTM D3363-92a test method, ⁴ : Good: smooth surface when scratched by hand, poor: jammed or scratched by hand,

⁵ : 3M company, ⁶ : Shin-Etsu company, ⁷ : BYK company

<Example 3>

A method of mixing 1-30 parts by weight of methacryloxypropyl trialkoxysilicate to solids when 3.5 mmol of 3,4-ethylenedioxythiophene, 8.1 mmol of ferrictoluenesulfonate, and 2.3 mmol of imidazole were mixed into 15 grams of acetone. A transparent antistatic polyester film was prepared in the same manner as in Comparative Example 5 except for the above.

The antistatic polyester film prepared by the above technique has a surface resistance of 1.0 × 10 ³ ohms / square and a transparency of 75% regardless of the content of methacryloxypropyltrialkoxysilicate added to the conductive polymer synthesis solution. Showed.

However, the adhesive force and the surface hardness is slightly different depending on the silicate content, the adhesive strength is 2-5B, the surface hardness is HB-4H within the range used in this embodiment. If the silicate content is more than 10 parts by weight, the surface hardness tended to decrease rather.

Therefore, when a predetermined amount of alkoxysilicate is mixed in the mixed solution for conducting polymer synthesis, the adhesiveness and surface pencil hardness of the antistatic polyester film are greatly improved.

Table 2. Surface Physical Properties According to Methacrylicoxypropyltrialkoxysilicate Content

Silicate Content (parts by weight) 1.0 2.0 5.0 10 20 30 Surface resistance (Ω / □) 10 ³ 10 ³ 10 ³ 10 ³ 10 ³ 10 ³ Transparency (550 nm,%) 75-80 75-80 75-80 75-80 75-80 75-80 Adhesive force (ASTM D3359) 2B 3B 5B 5B 5B 4B Surface Hardness (ASTM D3363-92a) HB 2H 3-4H 4H 3H 2H

<Example 4>

A transparent antistatic polyester film was prepared in the same manner as in Example 3 except for adding a surfactant (Shin-Etsu Corp., KP322) to the conductive polymer synthesis solution.

The surface resistance of the antistatic polyester film produced by the above technique is 1 × 10 ³ ohms / square, the transparency is 75%, the adhesion is 5B, the surface pencil hardness is 4H, and the surface of the produced antistatic polyester film is especially It was very smooth.

<Example 5>

A transparent antistatic polyester film was prepared in the same manner as in Example 4 except that no alkyl trialkoxysilicate was added.

The antistatic polyester film prepared by the above technique had the same surface resistance and transparency as Example 4, but the adhesiveness and surface hardness showed the same physical properties as those of Comparative Example 5, that is, adhesive B and surface pencil hardness 2B. Therefore, when using a polyester film coated with an acrylic resin as a substrate, it is not expected to improve the surface properties only with a surfactant.

<Example 6>

In coating a polyester film surface with 3.5 mmol of 3,4-ethylenedioxythiophene, 8.1 mmol of ferrictoluenesulfonate, and 2.3 mmol of imidazole in 15 grams of acetone, the thickness of the coating film was 0.5 micron and 1 micron. A transparent antistatic polyester film was prepared in the same manner as in Example 1 except for the above.

Adhesiveness and surface pencil hardness of the antistatic film thus prepared were the same as the results of Example 1 as 5B and 4H irrespective of the thickness of the coating film. However, the surface resistance of the transparent antistatic polyester film having a coating thickness of 1.0 micron was increased to 10 ⁴ ohms / square and the transparency was 81%. The surface resistance of the transparent antistatic polyester film having a coating thickness of 0.5 micron was increased to 10 ⁶ ohms / square and the transparency was 95%.

<Example 7>

A transparent antistatic polyester film was prepared in the same manner as in Example 6 except that the coating solution prepared according to Example 6 was applied to a polyester film coated with an acrylic resin.

The antistatic polyester film prepared by the above method showed the same characteristics as the antistatic polyester film prepared according to Example 6.

<Example 8>

The acrylic polyol was dissolved in ethyl alcohol to make a 10% solution, which was then coated on an amorphous polyester film with a thickness of 1 micron and dried by hot air at about 40 degrees Celsius.

On this film, 5 parts by weight of methacryloxypropyltrialkoxysilicate, based on solids, was added to a solution of 3.5 mmol of 3,4-ethylenedioxythiophene, 8.1 mmol of ferrictoluene sulfonate, and 2.3 mmol of imidazole in 15 grams of acetone. A solution containing 5 parts by weight of an active agent (Shin-Etsu Co., Ltd., KP322) was coated to a thickness of 1 micron, and then dried at 70 degrees Celsius for 5 minutes to induce a synthesis reaction. After the reaction was completed, the film was taken out, washed with ethyl alcohol and dried again to prepare an amorphous polyester film.

The amorphous polyester film produced by the above technique showed surface resistance of 10 ⁴ ohms / square, transparency of 85%, adhesion of 5B, and surface hardness of 3H.

<Example 9>

3.5 mmol of 3,4-ethylenedioxythiophene, 8.1 mmol of ferrictoluenesulfonate, and 2.3 mmol of imidazole were dissolved in 150 grams of acetone, and then 5 parts by weight of methacryloxypropyltrialkoxysilicate, based on solids, was added to the solution. 5 parts by weight of the active agent (Shin-Etsu Co., Ltd., KP322) was mixed with respect to a solid to prepare a coating solution.

After the solution was coated on the surface of the acrylic polyester film, the reaction was induced by heating at 120 ° C. for 2 minutes to obtain an antistatic polyester film.

The surface resistance of the antistatic polyester film prepared by the above technique showed 10 ⁴ -10 ⁵ ohms / square, transparency of 92%, adhesion of 5B, and surface hardness of 4H. This result shows that even when the concentration of the conductive polymer monomer and the oxidizing agent used in the present invention is diluted 10 times compared to [Example 4], the surface hardness and adhesion are the same, but the transparency is greatly improved. At this time, the surface resistance increased by about 1-2 orders.

<Example 10>

7.5 parts by weight of diisocyanate was mixed with respect to 100 parts by weight of the acrylic polyol on the polyester film prepared in Example 9, and then dissolved in ethyl acetate to prepare a 10% solution, which was coated to a thickness of 0.5 micron to form a protective layer.

The antistatic polyester film prepared by the above technique was not damaged by the conductive polymer film even if it was washed with an eyeglass cleaning cloth moistened with a solvent such as ethyl alcohol, isopropyl alcohol or acetone, and thus there was no change in surface resistance.

In Example 1-4, when the 3,4-polyethylenedioxythiophene film was formed on the polyester film by using the conductive polymer synthesis solution mixed with the surfactant, the surface resistance, transparency, and adhesiveness were maintained the same. While it can be seen that the surface pencil hardness of the antistatic polyester film slightly increased.

<Comparative Example 1>

On a commercially available uncoated polyester film, a mixed solution of 3.5 mmol of 3,4-ethylenedioxythiophene, 8.1 mmol of ferrictoluenesulfonate and 2.3 mmol of imidazole in 15 g of acetone was coated to a thickness of 1.5 microns and then 3,4-polyethylenedioxythiophene was synthesized on the polyester surface by heating in a thermocycle oven at 100 degrees Celsius for 2 minutes. The film was taken out of the thermocycle oven, washed with ethyl alcohol and dried again to prepare a polyester film.

The surface resistance of the polyester film prepared by the above method was 2.5 × 10 ³ ohms / square, the transparency was measured to be 70%, and the adhesion and surface hardness were not enough to be measured. It was.

<Comparative Example 2>

3.5 mmol of 3,4-ethylenedioxythiophene, 8.1 mmol of ferrictoluenesulfonate, 2.3 mmol of imidazole, and 5.0 mmol of polyvinyl alcohol were mixed in 15 grams of deionized distilled water and then coated on a 1.5 micron thick uncoated polyester film. A polyester film was prepared in the same manner as in Comparative Example 1 except for the one.

The polyester film produced by the above method had a surface resistance of 1.0 × 10 ³ ohms / square, transparency of 74%, pencil hardness of HB, and adhesiveness of 2B.

<Comparative Example 3>

In the same manner as in Comparative Example 2, except 3.5 mmol of 3,4-ethylenedioxythiophene, 8.1 mmol of ferrictoluenesulfonate, 2.3 mmol of imidazole, and 0.5 mmol of acryl polyol in 15 grams of ethyl alcohol. To prepare a polyester film.

The polyester film prepared by the above method is taken out of the thermocycle oven and then the coated conductive polymer membrane is washed while washing with ethyl alcohol.

<Comparative Example 4>

3.5 mmol of 3,4-ethylenedioxythiophene, 8.1 mmol of ferrictoluenesulfonate, and 2.3 mmol of imidazole were mixed with acetone. 0.5 mmol of polymethylmethacrylate (PMMA) was added to N, N-dimethylformamide (N, N-Dimethylformamide) and N-Methyl-2-pyrrolidinone (N-Methyl-2-pyrrolodinone) were mixed in a weight ratio 1: 1, except that the coating solution was prepared by mixing the weight ratio 1: 1 with Comparative Example 2 and In the same manner to prepare a polyester film.

The polyester film prepared by the above method had a surface resistance of 1.0 × 10 ³ ohms / square, transparency of 73%, adhesiveness of B, and surface pencil hardness of 2B.

<Comparative Example 5>

All methods were performed in the same manner as in Comparative Example 1 except for using a polyester film coated with an acrylic resin as the substrate polymer film, thereby preparing a polyester film.

The polyester film produced by the above method had a surface resistance of 1.0 × 10 ³ ohms / square, transparency of 73%, adhesiveness of B, and surface pencil hardness of 2B.

<Comparative Example 6>

3.5 mmol of 3,4-ethylenedioxythiophene, 8.1 mmol of ferrictoluenesulfonate, and 2.3 mmol of imidazole were dissolved in 15 grams of acetone, and then 5 parts by weight of methacryloxy propyltrialkoxysilicate, based on solids, and surfactant were added to the solution. (Shin-Etsu Co., KP322) 5 parts by weight of the solid content was mixed to form a coating solution. The solution was coated on an acrylic treated polyester film, and then heated at 120 ° C. for 2 minutes to induce a reaction to prepare an antistatic polyester film.

Rubbing the surface of the antistatic polyester film produced by the above technique with a spectacled wiping cloth moistened with isopropyl alcohol peeled off the 3,4-polyethylenedioxythiophene film formed on the polyester surface. The damaged part showed high surface resistance and insulation.

As shown in Comparative Example 1-5, 3,4-polyethylene on the surface of the polyester using a solution of 3,4-ethylenedioxythiophene, ferric toluenesulfonate, imidazole on a non-coated polyester film When forming a film dioxythiophene, surface resistance of ^{1 × 10 3 - 3 × 10} 3 ohm / □, while the showing surface resistance transparent diagram showing a 70% or more characteristic adhesion and a surface pencil hardness was found to show a very bad properties This phenomenon can be seen that the same occurs when the acrylic resin-coated polyester resin is used as a substrate polymer or when a 3,4-polyethylenedioxythiophene film is formed by using a binder on an uncoated polyester film.

In Comparative Examples 1-5, the surface resistance and the transparency are similar to each other. The surface resistance is the content ratio of 3,4-ethylenedioxythiophene and ferrictoluenesulfonate, the concentration ratio of these mixtures dissolved in a solvent, and the coating thickness. Because it is determined. Fixing the concentration and the coating thickness of these can be seen that the surface resistance and transparency does not show a big difference.

Using the techniques of the present invention when the surface resistivity is 10 ¹⁰ ohm / □ (ohms / square) from 10 ² ohms / □ adjustment is possible, while the transmittance at 550 nm up to less than 90%, the adhesive force by the ASTM D3359 method by It is this 5B and the transparent antistatic polyester film which is 2H or more in surface pencil hardness by the ASTM D3363-92a method can be manufactured.

Claims (8)

In the synthesis of the conductive polymer film directly on the polyester film by applying a solution (base resin dispersion) mixed with a conductive polymer monomer, an oxidant and a dopant on the polyester surface of the substrate, the substrate is subjected to pretreatment (primer coating) before the conductive film synthesis. Transparent permanent antistatic polyester film, characterized in that the adhesion to the film is improved and the durability is increased by forming a protective coating film. The method of claim 1, wherein the conductive polymer, thiophene, aniline, pyrrole and thiophene substituted ethylene dioxy group, a thiophene substituted with alkyl having 4 to 10 carbon atoms, sulfonyl aniline, A transparent permanent antistatic polyester film, characterized in that it is a nucleus pyrrole or a monomer modified from these monomers. The method of claim 1, wherein a binder of epoxy-based, acrylic-based or urethane-based or a mixture of these and other resins in a thickness of 0.01-5 microns on the surface of the polyester film to improve adhesion between the synthesized conductive polymer and the polyester film or After coating with a modified adhesion-enhanced resin modified from these, and then coated with a conductive layer and dried for 1-20 minutes at 70-150oC to use a transparent permanent antistatic polyester, characterized in that the use of a polyester polymer film formed a primer layer as a substrate film. According to claim 1, 1-30 parts by weight of alkyl trialkoxysilicate, i.e., an alkyl group containing a functional group of methacrylicoxypropyl, vinyl, organic-inorganic interface for 100 parts of the conductive polymer mixture to increase the hardness of the conductive coating film A transparent permanent antistatic polyester film, characterized in that it is prepared from a coating solution comprising a silicate, an amine silicate or an acrylic silicate used as a coupling agent. delete delete The method of claim 1, wherein in order to protect the conductive polymer film formed on the surface of the polyester film and to increase the durability, using an acrylic polyol and an isocyanate mixture, a silicate compound or an acrylic polymer, a urethane polymer, etc. Transparent antistatic polyester film, characterized in that the coating to form a protective layer. delete