JP2010285591A - Antistatic polyester film containing acetylene diol-based surfactant and method for producing the film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antistatic polyester film which has improved defective appearance of coating and to provide a method for producing the antistatic polyester film. <P>SOLUTION: An antistatic coating composition contains 0.001-1 parts weight acetylene diol-based surfactant in addition to 100 parts weight composition containing: 100 parts weight electroconductive polymer resin; 100-1,000 parts weight water-dispersible polyurethane resin comprising an anionic polyether-polyurethane dispersion having at least one functional group selected from the group comprising a hydroxyl group, an amine group, an alkyl group and a carboxyl group; 100-1,000 parts weight cross-linking agent resin selected from the group comprising isocyanate-based ones, carbonyl imide-based ones, oxazoline-based ones, epoxy-based ones and melamine-based ones; and 10-100 parts weight fluorocarbon resin. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an antistatic polyester film containing an acetylenic diol-based surfactant and a method for producing the same, and more specifically, a conductive polymer resin is used to achieve excellent antistatic performance and a polyurethane resin is contained. In addition to improving the peel strength from the adhesive tape, it contains a crosslinker resin to improve the solvent resistance and coating film performance by adjusting the crosslink density, and contains a fluororesin to improve the antifouling performance. The present invention relates to an antistatic polyester film which can easily control the physical properties of the coating while minimizing coating appearance defects by further containing an acetylenic diol surfactant in the composition, and a method for producing the same.

  In general, a polymerized film is easy to bend due to its high elasticity and is excellent in mechanical properties, heat resistance, transparency and chemical resistance, so it is used for photography, drawing, OHP, electrical Widely used in all fields of industry as applications for electronic parts, general industrial and packaging materials.

  However, in spite of the excellent physical properties of the polymerized film as described above, the film surface has a very high specific resistance. Therefore, when friction is applied, the film surface tends to be easily charged. In this case, when the polymerized film is charged, foreign matter such as dust adheres to the film surface due to static electricity, and the product to which the film is applied has an inconvenience that an electric shock is applied and a product defect occurs. .

  In addition, there is an inconvenience that a fire occurs when a discharge occurs in a film manufacturing process or a processing process using a chemical substance such as an organic solvent.

  Known techniques for suppressing the generation of static electricity in the film as described above include internal addition methods in which organic sulfonates or organic phosphates are mixed during film production, metal vapor deposition methods in which metal compounds are vapor-deposited on the surface, and conductive inorganic materials. There are a method of applying particles to the surface, a method of applying an anionic or cationic monomolecular compound or polymer compound to the surface, and the like. Among these methods, although the internal addition method is excellent in stability due to aging, it has the disadvantage that the excellent physical properties inherent in the film and the antistatic effect are reduced. The method of applying inorganic particles has recently been in the spotlight because of its excellent antistatic properties, but it is currently used only in special fields where the production cost is too high and high antistatic properties are required. It is. On the other hand, the coating method using the anionic or cationic monomolecular compound has a relatively good antistatic effect and is advantageous from the viewpoint of production cost, and thus has been widely applied. Various research and development have been made.

  Various techniques relating to coating methods for anionic or cationic monomolecules have been proposed. For example, an antistatic polyester using polydiaryldimethylammonium chloride, which is a polymeric quaternary ammonium, as an antistatic agent. A technique relating to a film is disclosed (for example, see Patent Document 1 below), and a technique using an acrylic polymer in which a quaternary ammonium group is attached to the terminal of an acrylic amide as an antistatic agent is disclosed. (For example, see Patent Document 2 below), and a silicon compound containing a cation-modified silicon compound made of quaternary ammonium chloride was applied to a base film and cured to form a low reflective layer. An antireflection film is disclosed (for example, see Patent Document 3 below).

  In the products using the various antistatic types described above, recently, the demand for antistatic films has increased rapidly in conjunction with the growth of the display industry.

  As the antistatic type frequently used for this purpose, it is currently known that the cation antistatic type is the most common, and films using conductive polymers are on the market as high-grade films. .

  In short, in the field of antistatic polyester film, it is required to have both excellent antistatic performance and antifouling performance, but depending on the in-line coating method, it is difficult to have the above two types of performance together. It has been pointed out.

  Also, when the protective film is affixed, if the peeling force between the tape used and the antistatic surface is low, the protective film will not be peeled off or the product may be affected during the peeling process. There is a need for a product with high peel strength from the adhesive tape.

  However, in the case of conventional in-line coating, coating properties such as leveling and wettability are insufficient due to high surface tension of the film coating surface, and the coating defects caused by this result are the main causes of lowering productivity and yield. If the surfactant content is increased to solve the above problem, it is very difficult to find the optimum coating solution composition because the physical properties of the coating are lowered.

  Therefore, as a result of diligent efforts to solve the above-mentioned problems, the present inventors have improved the coating properties by controlling the viscosity and surface tension of the coating composition liquid while being manufactured by the in-line coating method, thereby preventing the antistatic effect. The present invention has been completed by producing an antistatic polyester film with easy control of coating properties such as properties, antifouling properties, and peeling force.

Korean Published Patent No. 2003-0022713 US Pat. No. 5,925,447 Korean Published Patent No. 2002-0010877

  An object of the present invention is to provide an antistatic coating composition which further contains an acetylenic diol-based surfactant for providing an antistatic polyester film with easy control of coating physical properties and has improved coating appearance defects. .

  Another object of the present invention is to apply an antistatic coating composition by an in-line coating method, exhibit excellent transparency and antistatic properties, and is excellent in peel strength from adhesive tape, antifouling performance and coating properties. In particular, it is an object of the present invention to provide an antistatic polyester film that can easily control physical properties and can quickly respond to requirements due to market changes, and a method for producing the same.

  In order to achieve the above object, the present invention provides an antistatic coating composition for satisfying optimum physical properties, comprising 100 parts by weight of a conductive polymer resin, a hydroxyl group, an amine group, an alkyl group and a carboxyl group. 100 to 1000 parts by weight of a water-dispersible polyurethane resin comprising an anionic polyether polyurethane dispersion containing at least one functional group selected from the group consisting of an isocyanate, a carbonylimide, an oxazoline, an epoxy and a melamine Acetylenediol surfactants 0.001 to 100 parts by weight of a composition containing 100 to 1000 parts by weight of a crosslinking agent resin selected from the group consisting of 10 to 100 parts by weight of fluororesin Anti-static coating set with improved coating appearance defect further containing 1 part by weight To provide things.

  The acetylenic diol surfactant used in the antistatic coating composition with improved coating appearance defects of the present invention is a compound represented by the following chemical formula 1.

(In the above formula, R ₁ and R ₄ are C _{3 to} C ₁₀ linear or branched alkyl groups, halogen-substituted alkyl groups, vinyl groups, allyl groups, ethynyl groups, phenyl groups, aryl groups. (Aryl) group, halogen group, C ₃ -C ₁₀ alkoxy group, cyano group, amino group, hydroxyl group, carbonyl group, ester group, or carboxyl group, R ₂ and R ₃ are H or C ₁ -C _{5 is} an alkyl group, and m, n, p, and q are constants of 0 to 20.)
By further containing an acetylenic diol surfactant in the coating composition of the present invention, the coating property can be improved without a decrease in physical properties. At that time, the content of the acetylenic diol surfactant is the conductive polymer. It is to further contain 0.001 to 1 part by weight with respect to 100 parts by weight of the composition containing the resin, the polyurethane resin, the crosslinking agent resin and the fluororesin.

  The water-dispersible polyurethane resin used in the antistatic coating composition with improved coating appearance defects according to the present invention is allylamine, vinylamine, ethyleneamine, vinylpyridine, diethylaminoethyl methacrylate, diallyldimethylammonium chloride, methacryloyloxyethyltrimethylammonium sulfate. And anionic polyether polyurethane dispersions containing functional groups as repeating units selected from the group consisting of these and combinations thereof; or selected from the group consisting of methyl, ethyl, propyl, butyl, pentyl, hexyl and combinations thereof And anionic polyether polyurethane dispersions containing functional groups as repeating units.

  The conductive polymer resin used in the antistatic coating composition of the present invention is an aqueous dispersion containing a polyanion and a polythiophene, or an aqueous dispersion containing a polyanion and a polythiophene derivative. The content of polyanions in the dispersion is 1-5% by weight.

  The fluororesin used in the antistatic coating composition of the present invention is tetrafluoroethylene, trifluoroethylene, hexafluoropropylene copolymer, chlorotrifluoroethylene, tetrafluoroethylene copolymer, chlorotrifluoroethylene, It is at least one selected from the group consisting of a tetrafluoroethylene copolymer, polyvinyl fluoride, and polyvinylidene fluoride.

  The solid content contained in the antistatic coating composition of the present invention is 0.5 to 10.0% by weight.

  The present invention provides an antistatic polyester film comprising an antistatic layer formed by applying the antistatic coating composition on one or both sides of a polyester film.

The antistatic polyester film of the present invention has a peeling force with a NITTO # 31B tape of 1,000 g / in or more and a peeling force with a 3M # 244 tape of 100 g / 18 mm or more, and the surface resistance value of the antistatic polyester film Is ensured such that the antistatic property is less than 10 ¹¹ Ω / sq. The antistatic polyester film has a water contact angle of 90 ° or more, and has an excellent antifouling function.

  Therefore, the antistatic polyester film of the present invention is effectively applicable to any one type of optical display device selected from the group consisting of a liquid crystal display, a plasma display, a personal information terminal for personal use, and navigation.

  Further, in the present invention, a polyester film is uniaxially stretched, and the antistatic coating composition is applied to one or both sides of the uniaxially stretched polyester film to form an antistatic layer. A method for producing a biaxially stretched polyester film by further stretching a formed polyester film, and a method for producing an antistatic polyester film performed by an in-line coating method is provided.

  Therefore, while being performed by the in-line coating method of the present invention, the coating properties are improved by controlling the viscosity and surface tension of the coating composition liquid, and the control of coating properties such as antistatic properties, antifouling properties and peeling force is easy. An antistatic polyester film can be provided.

  By providing the antistatic coating composition of the present invention, the conductive polymer is contained to achieve excellent antistatic performance, and the polyurethane resin is contained to improve the peeling force from the adhesive tape, Uses a cross-linking agent to improve the solvent resistance and coating film performance by adjusting the cross-linking density, and to improve the antifouling performance by adding a fluororesin. In particular, the coating composition further contains an acetylenic diol surfactant. Accordingly, the physical properties of the coating can be easily adjusted because the change in the physical properties depending on the content is small while minimizing the appearance defect of the coating.

  Furthermore, when the antistatic coating composition of the present invention is applied to one or both sides of a polyester film, the peel strength from the adhesive tape and the antifouling performance are improved while being excellent in transparency and antistatic property. Therefore, it is possible to provide an antistatic polyester film that can be easily controlled and can quickly respond to the requirements due to market changes.

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

  The present invention is an antistatic coating composition for satisfying optimum physical properties, and is at least one selected from the group consisting of 100 parts by weight of a conductive polymer resin and a hydroxyl group, an amine group, an alkyl group and a carboxyl group. 100 to 1000 parts by weight of a water-dispersible polyurethane resin comprising an anionic polyether polyurethane aqueous dispersion containing various functional groups, and selected from the group consisting of isocyanate, carbonylimide, oxazoline, epoxy and melamine Further, 0.001 to 1 part by weight of an acetylenic surfactant is further included with respect to 100 parts by weight of the composition containing 100 to 1000 parts by weight of any one kind of the crosslinking agent resin and 10 to 100 parts by weight of the fluororesin. An antistatic coating composition having improved coating appearance defects is provided.

  Hereafter, each composition of the antistatic coating composition which improved the coating external appearance defect of this invention is explained in full detail.

  The conductive polymer resin contained in the antistatic coating composition with improved coating appearance defects according to the present invention is used for imparting excellent antistatic performance, and preferably contains poly anion and polythiophene. An aqueous dispersion or an aqueous dispersion containing a polyanion and a polythiophene derivative is used.

  In the above, the poly anion is an acidic polymer, such as a high molecular carboxylic acid, a high molecular sulfonic acid, or polyvinyl sulfonic acid. Examples of the polymer carboxylic acid include polyacrylic acid, polymethacrylic acid, and polymeric acid. Examples of the polymer sulfonic acid include polystyrene sulfonic acid.

  In the conductive polymer resin of the present invention, it is preferable from the aspect of imparting conductivity that the poly anion has an excessive solid content weight ratio with respect to the polythiophene or polythiophene derivative. For example, when it is assumed that 1% by weight of polythiophene or polythiophene derivative is used, the polyanion is preferably more than 1% by weight and 5% by weight or less, and more preferably in the range of 1 to 3% by weight. Therefore, in an example of the present invention, an aqueous dispersion containing 0.5% by weight of poly (3,4-ethylenedioxythiophene) and 0.8% by weight of polystyrene sulfonic acid (molecular weight Mn = 150,000) is prepared. Although used, it is not limited to this.

  Hereinafter, the polyurethane resin contained in the antistatic coating composition of the present invention will be described. The polyurethane resin used in the present invention is added to a polyester film to increase the peel force between the film surface and the tape.

  Accordingly, the preferred polyurethane resin used in the present invention is an aqueous dispersion type, and an anionic polyether polyurethane containing at least one functional group such as hydroxyl group, amine group, alkyl group and carboxyl group. A resin made of an aqueous dispersion is used.

  More specifically, the water-dispersible polyurethane resin is an anionic polyether polyurethane dispersion containing hydroxyl groups; allylamine, vinylamine, ethyleneamine, vinylpyridine, diethylaminoethyl methacrylate, diallyldimethylammonium chloride, methacryloyloxyethyltrimethylammonium sulfate. And an anionic polyether polyurethane dispersion containing a functional group as a repeating unit selected from the group consisting of these combinations or a repeating group selected from the group consisting of methyl, ethyl, propyl, butyl, pentyl, hexyl and combinations thereof An anionic polyether polyurethane dispersion containing functional groups as units is used.

  On the other hand, the addition amount of the polyurethane resin is 100 to 1000 parts by weight of the polyurethane resin with respect to 100 parts by weight of the conductive polymer resin. At this time, if the addition amount of the polyurethane resin is less than 100 parts by weight, the peeling force with the tape is lowered and the function cannot be expressed, and if it exceeds 1000 parts by weight, the tape peeling force is sufficiently secured. No, there arises a problem that the antifouling function and the antistatic performance are lowered.

  Hereinafter, the crosslinking agent contained in the antistatic coating composition of the present invention will be described. The cross-linking agent used in the present invention is used for adjusting the cross-linking density to improve the solvent resistance and coating film performance between the antistatic layer and the polyester film. At this time, as a suitable crosslinking agent component, any one or more resins selected from the group consisting of isocyanate, carbonylimide, oxazoline, epoxy, and melamine are listed.

  On the other hand, the addition amount of the crosslinking agent is 100 to 1000 parts by weight of the crosslinking agent resin with respect to 100 parts by weight of the conductive polymer resin. At this time, if the addition amount of the crosslinking agent resin is less than 100 parts by weight, the antistatic property may not be exhibited well, the solvent resistance is weak, and the whitening phenomenon may occur. On the other hand, if it exceeds 1000 parts by weight, the transparency may be good, but there may be a problem that the antistatic property is hardly exhibited.

  Of the antistatic coating composition, the fluororesin used in the present invention is added to the polyester film so as to improve the antifouling property and solvent resistance of the film.

  Suitable fluororesins include tetrafluoroethylene, trifluoroethylene, hexafluoropropylene copolymer, chlorotrifluoroethylene, tetrafluoroethylene copolymer, chlorotrifluoroethylene, polytetrafluoroethylene copolymer, polyvinyl Fluoride, polyvinylidene fluoride, etc.

  At this time, the addition amount of the fluororesin is 10 to 100 parts by weight of the fluororesin with respect to 100 parts by weight of the conductive polymer resin. If the addition amount of the fluororesin is less than 10 parts by weight, the antifouling property is lowered, whereas if it exceeds 100 parts by weight, the transparency of the film, the tape peeling force and the antistatic performance are lowered. May occur.

  In the antistatic coating composition of the present invention, a surfactant is added to improve the stability, wettability and coating leveling of the coating composition.

  In general, the use of a surfactant improves the wettability and coating leveling of the coating composition, but has the disadvantage that the main physical properties such as the peel strength from the tape and antifouling properties are reduced. On the other hand, the antistatic coating composition of the present invention uses an acetylenic diol-based surfactant as a surfactant, thereby improving the wettability and coating leveling of the coating composition, and the peel strength from the adhesive tape, By maintaining the main coating properties such as antifouling properties, conventional problems are solved.

  That is, as shown in Table 1 of the present invention, in the antistatic coating composition with improved coating appearance defects according to the present invention, when a conventional acrylate surfactant is contained [Comparative Example 3], acetylenediol An anti-fouling property is insufficient compared with the composition containing the surfactant, and the wettability of the coating film is reduced. In particular, the result of a low peeling force value with a commercial 3M tape can be confirmed.

  Further, when the surfactant is not contained in the antistatic coating composition [Comparative Example 4], the coating leveling property and the coating wettability are remarkably deteriorated, resulting in a coating appearance defect.

  Therefore, by further including an acetylenic diol surfactant in the coating composition of the present invention, the main coating physical properties such as peelability from the adhesive tape and antifouling properties while realizing excellent wettability and coating leveling properties. This is advantageous in improving the defect of the coating appearance. Therefore, by using the antistatic coating composition of the present invention, it is possible to provide an optical antistatic polyester film having excellent quality and high yield rate.

  The acetylenic diol surfactant used in the antistatic coating composition with improved coating appearance defects according to the present invention is the use of a compound represented by the following chemical formula 1.

(Wherein R ₁ and R ₄ are C _{3 to} C ₁₀ linear or branched alkyl groups, halogen-substituted alkyl groups, vinyl groups, allyl groups, ethynyl groups, phenyl groups, aryl groups, halogen atoms, A group, a C ₃ -C ₁₀ alkoxy group, a cyano group, an amino group, a hydroxyl group, a carbonyl group, an ester group, or a carboxyl group, and R ₂ and R ₃ are H or a C ₁ -C ₅ alkyl group. , M, n, p, q are constants of 0-20.)
In an embodiment of the present invention, a preferred compound of an acetylenic diol-based surfactant, which is 2,5,8,11-tetramethyl 6-dodecyne-5,8-diethoxylate (2,5,8,11-tetramethyl 6 dodecyn) −5,8 diol ethylate) is used, but is not limited thereto.

  That is, the acetylenediol surfactant of the present invention is a trifluoromethyl group, a methyl group, a vinyl group, an allyl group, an ethynyl group, a phenyl group, an aryl group, a halogen group, an alkoxy group, a cyano group, an amino group, a hydroxyl group, An acetylenic diol surfactant containing at least one functional group selected from the group consisting of a carbonyl group, an ester group and a carboxyl group can be used.

  At this time, a suitable content of the acetylenic diol-based surfactant is 0.001 to 1 part by weight with respect to 100 parts by weight of the composition containing the conductive polymer resin, the polyurethane resin, the crosslinking agent and the fluororesin. . If the addition amount of the surfactant is less than 0.001 part by weight, the wettability of the coating film is lowered, and if it exceeds 1 part by weight, a coating appearance defect is caused by fine bubbles in the coating composition.

  The antistatic coating composition of the present invention described above is preferably produced such that the solid content is 0.5 to 10.0% by weight with respect to 100% by weight of the total coating composition, Preferably, it is produced so that the solid content is 1.0 to 5.0% by weight. If the solid content is less than 0.5% by weight, it is not sufficient to develop the film formation and antistatic function of the coating layer, and if it exceeds 10.0% by weight, the transparency of the film is affected. Since it gives, it is not preferable.

  On the other hand, the solvent used in the antistatic coating composition is an aqueous coating liquid containing water as a main medium.

  Furthermore, the coating composition used in the present invention can contain a suitable organic solvent to the extent that the effects of the present invention are not impaired for the purpose of improving applicability and transparency. Examples of the solvent include isopropyl alcohol, butyl cellosolve, t-butyl cellosolve, ethyl cellosolve, acetone, ethanol, methanol and the like.

  However, if a coating composition contains a large amount of organic solvent, there is a risk of explosion during the drying, stretching and heat treatment steps when applied to the in-line coating method. The amount is controlled to 10% by weight or less, more preferably 5% by weight or less.

  The present invention provides an antistatic polyester film comprising an antistatic layer formed by applying the antistatic coating composition on one or both sides of a polyester film.

  The antistatic coating composition used for the antistatic polyester film of the present invention has a solid content, and an acetylenic surfactant is added to the coating composition containing a conductive polymer resin, a polyurethane resin, a crosslinking agent, and a fluororesin. Furthermore, since it is the aqueous coating liquid contained and the composition component and content are the same as the composition component and content of the antistatic coating composition mentioned above, the concrete description about this is abbreviate | omitted.

  The antistatic polyester film of the present invention can be optimized for desired physical properties depending on the specific composition of the antistatic coating composition.

  In other words, it contains a conductive polymer to achieve excellent antistatic performance, and contains a polyurethane resin to improve the peel strength from the adhesive tape, and contains an appropriate cross-linking agent to control the cross-linking density. Solvent properties and coating film performance can be improved, and antifouling performance can be improved by containing a fluororesin, and low coating properties can be improved by addition of an acetylenic diol surfactant.

  For this reason, the antistatic polyester film produced by applying this to one or both sides of the polyester film is excellent in transparency and antistatic property, and it is easy to remove coating appearance defects. The property can prevent deterioration of physical properties.

More specifically, the antistatic polyester film of the present invention is transparent, but has a surface resistance of less than 1 × 10 ¹¹ Ω / sq in the characteristics of the coating surface, and is organic such as ethanol, methyl ethyl ketone, toluene, and ethyl acetate. Even after the surface is wiped off with a solvent, the surface resistance is maintained at a value of less than 1 × 10 ¹¹ Ω / sq. Therefore, the antistatic agent of the antistatic layer has excellent solvent resistance that does not fall off or dissolve.

  In addition, the antistatic polyester film of the present invention has an excellent antifouling performance with a water contact angle of 90 ° or more, a peeling force with a Nitto31B tape of 1,000 g / in or more, and 3M # of 100 g / 18 mm or more. Has peel strength from 244 tape.

  In short, the present invention has an excellent performance in tape peeling force, antifouling function, solvent resistance and the like by the antistatic layer formed by applying the antistatic coating composition on one side or both sides of the polyester base film. In particular, since there is no decrease in physical properties due to the surfactant, it is possible to provide a polyester film satisfying difficult levels of physical properties that can meet the needs of larger LCD screens.

  More specifically, the antistatic polyester film of the present invention is effectively applied to any one type of optical display device selected from the group consisting of a liquid crystal display, a plasma display, a personal information terminal for personal use, and navigation. Can do.

Furthermore, the present invention provides
1) uniaxially stretching the polyester film;
2) applying an antistatic coating composition of the present invention to one or both sides of the uniaxially stretched polyester film to form an antistatic layer;
And 3) producing a biaxially stretched polyester by further stretching the polyester film on which the antistatic layer is formed, and using the antistatic coating composition of the present invention by an in-line method. An antistatic polyester film manufacturing method is provided.

  First, the first step of uniaxially stretching a polyester film will be described.

  The type of polyester film used in the present invention can be used without particular limitation as long as it is an ordinary resin known as a base film to which an antistatic coating is applied. In the present invention, polyethylene terephthalate, Although the description mainly focuses on polyester resins such as polybutylene terephthalate and polyethylene naphthalate, it goes without saying that the present invention is not limited thereto.

  Here, the polyester film means a polyester obtained by polycondensation of an aromatic dicarboxylic acid and an aliphatic glycol. As the aromatic dicarboxylic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid or the like is used. In addition to these, as the dicarboxylic acid component of the copolyester, isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, oxycarboxylic acid (for example, P-oxybenzoic acid, etc.) ) Can be used. Examples of the aliphatic glycol include ethylene glycol, diethylene glycol, 1,4-cyclohexanedimethanol, propylene glycol, butanediol, and neopentyl glycol. These dicarboxylic acid components and glycol components are used in combination of two or more. May be.

  Typical examples of the polyester film include polyethylene terephthalate (PET), polyethylene-2,6-naphthalenedicarboxylate (PEN), and a copolymer containing a third component in the polyester can also be used.

  The polyester resin having the structure described above is vacuum-dried and then melted by an extruder, extruded into a sheet using a T-die, brought into close contact with a casting drum by an electrostatic application method to a cooling roll, and cooled and solidified to obtain an unstretched polyester sheet. By passing this through a roll heated above the glass transition temperature of the polyester resin and performing uniaxial stretching of 2.5 to 4.5 times depending on the difference in running speed ratio between the rolls, uniaxial A stretched polyester film is produced.

  In the second stage of the method for producing an antistatic polyester film of the present invention, an antistatic layer is formed by applying the antistatic coating composition of the present invention to one or both sides of the uniaxially stretched polyester film in the first stage. It is the stage to do. Specifically, examples of the method for applying the antistatic coating composition include a Mayer bar method, a gravure method, and the like, by introducing a polar group on the surface of the film before application, and adhesion between the coating layer and the film. Corona discharge treatment can be performed so as to improve applicability.

  The antistatic coating composition of the present invention is an anionic polyether containing 100 parts by weight of a conductive polymer resin and at least one functional group selected from the group consisting of a hydroxyl group, an amine group, an alkyl group and a carboxyl group. 100 to 1000 parts by weight of a water-dispersible polyurethane resin comprising a polyurethane dispersion and 100 to 1000 parts by weight of any one crosslinking agent resin selected from the group consisting of isocyanate, carbonylimide, oxazoline, epoxy and melamine It is obtained by further adding 0.001 to 1 part by weight of an acetylenic surfactant based on 100 parts by weight of the composition containing 10 parts by weight and 10 to 100 parts by weight of the fluororesin.

  The antistatic coating composition of the present invention contains a conductive polymer resin to achieve excellent antistatic performance, and contains a polyurethane resin to improve the peeling force from the adhesive tape, and an appropriate crosslinking agent. Use to improve the solvent resistance and coating film performance by adjusting the crosslinking density, improve the antifouling performance by adding fluororesin, and add the acetylenediol surfactant to minimize the coating appearance defects By ensuring the physical properties, it is possible to provide an antistatic polyester film for optical use that is high in quality and has a high yield rate. The composition components and contents of the antistatic coating composition used in the second stage of the production method of the present invention are as described above.

  The third step of the method for producing an antistatic polyester film of the present invention is a step of producing a biaxially stretched polyester film by further stretching the polyester film formed with the antistatic layer obtained in the second step.

  At this time, the stretching in the third stage is performed in a direction perpendicular to the direction of uniaxial stretching, and the preferred elongation is 3.0 to 7.0 times. After finishing the stretching process, an antistatic polyester film can be produced by heat setting, curing and drying.

  The thickness of the biaxially stretched polyester film produced by the production method of the present invention is 5 to 300 μm, preferably 10 to 250 μm.

  Hereinafter, the present invention will be described in more detail with reference to examples.

  These examples are for explaining the present invention more specifically, and the scope of the present invention is not limited to these examples.

<Example 1>
Step 1: 1 produced an average particle diameter of the shaft oriented polyester film having an intrinsic viscosity 0.625dl / g of amorphous spherical silica particles of 2.5μm is within 20ppm polyethylene terephthalate pellets, over 7 hours using a vacuum drier After sufficiently drying at a temperature of 160 ° C., the mixture is melted, and further, an amorphous unstretched sheet is produced by closely adhering to a cooling drum using an extrusion T die by an electrostatic application method, and this is heated to 95 ° A uniaxially stretched polyester film was produced by further stretching 3.5 times in the traveling direction of the film at a temperature of C. Thereafter, the film surface to be coated was subjected to corona discharge treatment to produce a polyester film.

Step 2: Manufacture of biaxially stretched polyester film A conductive polymer resin (0.5% by weight of poly3,4-ethylenedioxythiophene and polystyrene sulfonic acid (molecular weight Mn = 150) as a solid content on the corona-treated surface. , 000) 0.8% by weight of an aqueous dispersion), 100 parts by weight of a polyurethane resin (an anionic polyether polyurethane dispersion containing a hydroxy group), an epoxy crosslinking agent (manufactured by Esprix Technology) , CR-5L) and 200 parts by weight of fluororesin (manufactured by DuPont, ZONYL) are mixed with water to produce a coating solution. An acetylenediol surfactant (2) with respect to 100 parts by weight of the coating solution. , 5,8,11-tetramethyl 6 dodecine-5,8 diethoxylate) 0.1 parts by weight And elephants. At this time, the solid content was 1.5% by weight with respect to the coating solution. The antistatic coating solution was applied to the uniaxial polyester film produced in Step 1 using a Mayer bar. After coating, the coating solution applied in the 105-140 ° C. tender section is dried, stretched 3.5 times in the direction perpendicular to the film traveling direction, and heat treated for 4 seconds at a temperature of 240 ° C. to 38 μm. A biaxially stretched antistatic polyester film having a thickness of 5 mm was produced.

<Example 2>
100 parts by weight of conductive polymer resin (aqueous dispersion containing 0.5% by weight of poly3,4-ethylenedioxythiophene and 0.8% by weight of polystyrene sulfonic acid (molecular weight Mn = 150,000)), polyurethane 400 parts by weight of a resin (an anionic polyether polyurethane dispersion containing a hydroxyl group), 200 parts by weight of an epoxy cross-linking agent (manufactured by Esprit Technology, CR-5L) and 150 parts by weight of a fluororesin are mixed in water and coated. A liquid is prepared, and 0.15 part by weight of 2,5,8,11-tetramethyl-6dodecine-5,8 diethoxylate is mixed with 100 parts by weight of the coating liquid, so that the total solid content is 2 A biaxially stretched antistatic polyester film was produced in the same manner as in Example 1 except that it was produced so as to be 0.0% by weight.

<Example 3>
A biaxially stretched antistatic polyester film was produced in the same manner as in Example 1 except that an anionic polyether polyurethane dispersion containing an allylamine group as a repeating unit was used as the functional group of the polyurethane resin.

<Example 4>
A biaxially stretched antistatic polyester film was produced in the same manner as in Example 1 except that an anionic polyether polyurethane dispersion containing an ethyl group as a repeating unit was used as the functional group of the polyurethane resin.

<Comparative Example 1>
A biaxially stretched antistatic polyester film was produced in the same manner as in Example 1 except that the fluororesin was not included in the composition of the antistatic coating solution.

<Comparative example 2>
A biaxially stretched antistatic polyester film was produced in the same manner as in Example 1 except that the polyurethane resin was not included in the composition of the antistatic coating solution.

<Comparative Example 3>
A biaxially stretched antistatic polyester film was produced in the same manner as in Example 1 except that an acrylate surfactant was contained in the composition of the antistatic coating solution instead of the acetylenic diol surfactant.

<Comparative example 4>
A biaxially stretched antistatic polyester film was produced in the same manner as in Example 1 except that the acetylenediol surfactant was not included in the composition of the antistatic coating solution.

<Comparative Example 5>
A biaxially stretched antistatic polyester film was produced in the same manner as in Example 1 except that 1.5 parts by weight of acetylenic diol surfactant was included in the composition of the antistatic coating solution.

<Experimental example>
The following physical properties were evaluated for the antistatic polyester films produced according to Examples 1 to 4 and Comparative Examples 1 to 5, and the results are shown in Table 1.

1. The water contact angle was measured using a droplet method with purified water obtained by distilling ion-exchanged water using a water contact angle contact angle measuring device (manufactured by Kyowa Interface Science Co., Ltd., model name: Dropmaster 300). The average value was taken after 5 measurements.

2. Using an antistatic measuring instrument (Mitsubishi Corporation, model name MCP-T600), after providing a sample in an environment of a temperature of 23 ° C and a humidity of 50% RH, the surface resistance is measured according to JISK7194. did.

3. Wet ethanol on an ethanol-resistant fabric (BEMCOT manufactured by Asahi Kasei Fiber Co., Ltd.), then reciprocate the coated film surface 10 times with a load of 0.5 kg, and then evaluate the state of the coated surface according to the following criteria: did.

○: When the change in antistatic property is within the range of 10 ¹ △: When the change in antistatic property increases by 10 ¹ or more and less than 10 ¹¹ ×: When the antistatic property exceeds 10 ¹¹
4). Peel strength with tape-1
Adhesive tape (manufactured by Nitto Denko Co., Ltd.) on the coating surface of the film obtained above using a peel force measuring instrument (AR1000 from Chemical Instruments) in an atmosphere of 23 ° ± 3 and relative humidity 50 ± 5% No. 31B, width: 25 mm) was pasted, and it was reciprocated once by a rubber roller with a load of 2 kg, and left for 1 hour, and then peeled 180 ° at a peeling speed of 0.3 MPM. At this time, the obtained peeling force value was measured.

5. Peel strength with tape -2
In an atmosphere of 23 ° ± 3 and relative humidity of 50 ± 5%, an adhesive tape (manufactured by 3M, tape NO. 244, width: 18 mm), and reciprocated once with a rubber roller with a load of 2 kg, and left for 1 hour, and then peeled 180 ° at a peeling speed of 0.3 MPM. At this time, the obtained peeling force value was measured.

6). Appearance of coating Compare the size and number of uncoated parts when visually observing the coated surface of the film obtained above using various light sources such as fluorescent lamps, halogens, and hundred-heat lamps. evaluated.

Those in which the area of the uncoated portion exceeded 1 mm × 3 mm were inspected. The inspection area was 1 m ² .

◎: 0 to 1 ○: 0 to 3 △: 3 to 10 ×: Over 10

  As is apparent from Table 1 above, in the case of Comparative Example 1 in which the composition of the antistatic coating liquid did not contain a fluororesin, it was confirmed that the water contact angle was low and the antifouling performance was lowered. In the case of the comparative example 2 which did not contain resin, the numerical value of tape peeling force showed a remarkably low result, and the desired physical property was not obtained. In the case of Comparative Example 3 in which an acrylate surfactant was used instead of an acetylenic diol surfactant, the antifouling property was insufficient due to the results of water contact angle and liquid surface tension. A decrease in the wettability of the film was confirmed, and in particular, the value of the peeling force with the commercial 3M tape was low, and the on-site applicability was reduced, and the desired physical properties were not obtained.

  Further, in the case of Comparative Example 4 in which the surfactant was not included in the composition of the antistatic coating liquid, the coating leveling property and the coating wettability were reduced by showing a high value of the liquid surface tension. In the case of Comparative Example 5 containing an excessive amount of acetylenic diol surfactant, a result insufficient to realize the optimum coating appearance quality was confirmed.

On the other hand, an antistatic layer was formed on the conductive polymer resin by using an antistatic coating solution containing a polyurethane resin and an appropriate crosslinking agent containing a fluororesin and an acetylenic diol surfactant. The polyester film produced according to No. 2 is transparent, and the surface resistance of the coating surface is less than 1 × 10 ¹¹ Ω / sq, and after wiping the surface with an organic solvent such as ethanol, methyl ethyl ketone, toluene, ethyl acetate, etc. Furthermore, since the surface resistance was maintained at a value of less than 1 × 10 ¹¹ Ω / sq, it was confirmed that the antistatic agent of the antistatic layer had excellent solvent resistance that would not drop off or dissolve. It has excellent antifouling performance with a water contact angle of 90 ° or more, and has a peeling force with a Nitto31B tape of 1,000 g / in or more and a peeling force with a 3M # 244 tape of 100 g / 18 mm or more. Therefore, it is possible to obtain a polyester film having a low surface tension and excellent wetting performance with no coating appearance defect or minimized.

  As described above, the present invention can first provide an antistatic coating composition in which desired physical properties are optimized. That is, the antistatic coating composition of the present invention contains a conductive polymer to achieve excellent antistatic performance, and contains a polyurethane resin to improve the peeling force from the adhesive tape, and is also suitable as a crosslinking agent. To improve the solvent resistance and coating film performance by adjusting the crosslink density, improve the antifouling performance by containing a fluororesin, and by applying an acetylenediol surfactant with a tape having low peeling force Peeling force and coating properties can be improved.

  Secondly, the antistatic coating composition of the present invention is applied to one side or both sides of a polyester film, and is excellent in transparency and antistatic property, and has improved peeling force and antifouling performance with an adhesive tape, in particular. An antistatic polyester film with improved coating appearance defects can be provided.

Third, the method for producing an antistatic polyester film of the present invention performed by an inline coating method has an excellent antistatic function, and even after wiping the surface with an organic solvent such as ethanol, methyl ethyl ketone, toluene, and ethyl acetate. Since the surface resistance is maintained at a value of less than 1 × 10 ¹¹ Ω / sq, the antistatic agent of the antistatic layer has excellent solvent resistance that does not fall off or dissolve, and has an excellent antifouling function and an adhesive tape. It is possible to provide an antistatic polyester film having improved peel strength and coating properties.

  Although the present invention has been described in detail only with respect to the embodiments described above, it is obvious to those skilled in the art that various changes and modifications can be made within the scope of the technical idea of the present invention. It goes without saying that various modifications and corrections belong to the scope of the claims.

Claims (14)

  Water-dispersible polyurethane resin comprising 100 parts by weight of conductive polymer resin and an anionic polyether polyurethane dispersion containing at least one functional group selected from the group consisting of hydroxyl group, amine group, alkyl group and carboxyl group 100 to 1000 parts by weight, 100 to 1000 parts by weight of a crosslinking agent resin selected from the group consisting of isocyanate, carbonylimide, oxazoline, epoxy and melamines, and 10 to 100 parts by weight of fluororesin An antistatic coating composition with improved coating appearance defects, further comprising 0.001 to 1 part by weight of an acetylenic diol surfactant with respect to 100 parts by weight of the composition containing The antistatic coating composition with improved coating appearance defect according to claim 1, wherein the acetylenic diol surfactant is a compound represented by the following chemical formula (Chemical Formula 1).

Wherein R ₁ and R ₄ are C _{3 to} C ₁₀ linear or branched alkyl groups, halogen-substituted alkyl groups, vinyl groups, allyl groups, ethynyl groups, phenyl groups, aryl groups, halogen groups, C ₃ -C ₁₀ alkoxy group, a cyano group, an amino group, a hydroxyl group, selected from a carbonyl group, an ester group or a carboxyl group,, R _2, R ₃ is H or an alkyl group C ₁ -C ₅ Yes, m, n, p, q are constants of 0-20   The water-dispersible polyurethane resin functions as a repeating unit selected from the group consisting of allylamine, vinylamine, ethyleneamine, vinylpyridine, diethylaminoethyl methacrylate, diallyldimethylammonium chloride, methacryloyloxyethyltrimethylammonium sulfate, and combinations thereof. 2. An antistatic coating composition with improved coating appearance defects according to claim 1, which is an anionic polyether polyurethane dispersion containing groups.   The water dispersible polyurethane resin is an anionic polyether polyurethane dispersion containing a functional group as a repeating unit selected from the group consisting of methyl, ethyl, propyl, butyl, pentyl, hexyl and combinations thereof. The antistatic coating composition having improved coating appearance defects according to claim 1.   The coating appearance defect according to claim 1, wherein the conductive polymer resin is an aqueous dispersion containing a polyanion and a polythiophene, or an aqueous dispersion containing a polyanion and a polythiophene derivative. Improved antistatic coating composition.   6. The antistatic coating composition with improved coating appearance defects according to claim 5, wherein the aqueous dispersion contains 1 to 5% by weight of polyanions.   The fluororesin is tetrafluoroethylene, trifluoroethylene, hexafluoropropylene copolymer, chlorotrifluoroethylene, tetrafluoroethylene copolymer, chlorotrifluoroethylene, polytetrafluoroethylene copolymer, polyvinyl fluoride and 6. The antistatic coating composition with improved coating appearance defects according to claim 5, wherein the composition is at least one selected from the group consisting of polyvinylidene fluoride.   The antistatic coating composition with improved coating appearance defect according to claim 1, wherein the solid content in the antistatic coating composition is 0.5 to 10.0 wt%. On one or both sides of the polyester film,
An antistatic polyester film having improved coating appearance defects, comprising an antistatic layer to which the antistatic coating composition according to claim 1 is applied. The surface resistance value after the surface of the antistatic polyester film is washed with any one organic solvent selected from the group consisting of ethanol, methyl ethyl ketone, toluene and ethyl acetate is less than 1 × 10 ¹¹ Ω / sq. The antistatic polyester film according to claim 9, wherein the antistatic property is maintained as described above.   10. The electrification according to claim 9, wherein the antistatic polyester film has a peeling force with a NITTO # 31B tape of 1,000 g / in or more and a peeling force with a 3M # 244 tape of 100 g / 18 mm or more. Prevent polyester film.   The antistatic polyester film according to claim 9, wherein a water contact angle of the antistatic polyester film is 90 ° or more. The polyester film is uniaxially stretched,
The antistatic coating composition according to claim 1 is applied to one or both sides of the uniaxially stretched polyester film to form an antistatic layer,
A method for producing an antistatic polyester film, wherein the polyester film having the antistatic layer formed thereon is further stretched to produce a biaxially stretched polyester film.   The method for producing an antistatic polyester film according to claim 13, wherein the solid content in the antistatic coating composition is 0.5 to 10% by weight.