KR101359625B1 - Anti-static polyester film and manufacturing method thereof - Google Patents

Abstract

The present invention relates to an antistatic polyester film and a method for producing the same.
The antistatic polyester film of the present invention is formed with an antistatic layer on one or both sides of the polyester film, an antistatic layer is formed by the in-line coating method with an antistatic coating composition containing a conductive polymer resin with an average particle diameter of 60 nm or less As a result, in the conventional inline coating, the coating thickness between the film widths is different by the lateral stretching process, and the problems of productivity and yield reduction due to the antistatic variation of the coating surface generated thereby can be solved. Accordingly, the present invention can provide an antistatic polyester film having excellent antistatic properties and having almost no antistatic width variation and excellent peeling force, antifouling performance, and coating property with transparency and adhesive tape.

Description

Antistatic polyester film and its manufacturing method {ANTI-STATIC POLYESTER FILM AND MANUFACTURING METHOD THEREOF}

The present invention relates to an antistatic polyester film and a method for manufacturing the same, and more particularly, one or both surfaces of the polyester film is modified to an average particle diameter of 60 nm or less. By forming the antistatic layer by the in-line coating method with the antistatic coating composition containing the conductive polymer resin, it is excellent in antistatic properties, there is little variation between the antistatic properties, transparency, peeling force with the adhesive tape, antifouling performance and coating properties The excellent antistatic polyester film and its manufacturing method are related.

In general, polymeric polymer films are excellent in mechanical properties, heat resistance, transparency, and chemical resistance while being well-elastic, so that they can be used for photographic, drafting, ouchip, electric and electronic parts, general industry and packaging materials It is widely used across all industries.

However, despite the excellent physical properties of the polymer-polymerized film as described above, there is a problem that the surface of the film is easily charged if friction is applied because the resistivity of the film surface is very large. In this case, when the polymer-polymerized film is charged, foreign matter such as dust adheres to the surface of the film due to static electricity, and electric shock is applied to the product to which the film is applied, resulting in defective products.

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

Examples of the known technique for suppressing the generation of static electricity in the film include an internal addition method in which an organic sulfonic acid salt or an organic phosphate is mixed in the production of a film, a metal vapor deposition method in which a metal compound is deposited on the surface, A method of applying an anionic or cationic monomolecular compound or a polymer compound to the surface, and the like. Among the above methods, the internal addition method is excellent in stability against changes over time, but has a problem that excellent physical properties inherent to the film and antistatic effect are reduced. The metal deposition method and the method of applying the conductive inorganic particles have excellent antistatic properties However, it is used only in special fields requiring high antistatic properties because the manufacturing cost is too high. On the other hand, the coating method using the anionic or cationic monomolecular compound has been widely applied to a variety of research and development, because it has a relatively good antistatic effect and is advantageous in terms of manufacturing cost.

With the recent growth of the display industry and the increasing demand for antistatic films, products using various antistatic types as described above are emerging. Among them, the most popular antistatic type is a cationic antistatic type, and in particular, the high-grade film market using a conductive polymer is expanding.

Conductive polymers have been widely used in off-line coatings because of their excellent transparency and antistatic properties. However, the in-line coating method has been pointed out as a problem of productivity due to lateral deviation of antistatic performance due to transverse stretching.

Thus, the inventors of the present invention in the conventional in-line coating, the coating thickness between the film width is different by the lateral stretching process, and the resulting antistatic performance deviation of the coating surface resulting from this to try to solve the problem of productivity and yield degradation, the average particle diameter 60nm or less The present invention was completed by applying an electrically conductive polymer resin modified by using an in-line coating method to produce an antistatic polyester film with little variation in antistatic properties by an inline coating method and easily controlling an antistatic property.

An object of the present invention is to provide an antistatic polyester film which is excellent in antistatic property and has little variation in antistatic properties.

Another object of the present invention is to provide a conductive polymer resin-containing antistatic coating composition which is excellent in antistatic property but has almost no width variation of antistatic property and is excellent in transparency, And to provide a method for producing an antistatic polyester film excellent in performance and coating property.

In order to achieve the above object, the present invention is formed on one side or both sides of the polyester film, an antistatic layer coated with an antistatic coating composition containing a conductive polymer resin by an inline coating method, the antistatic polyester film An antistatic polyester film having an antistatic width difference, that is, an edge portion and a center portion variation of 10% or less is provided.

At this time, the surface resistance of the edge portion and the center portion of the antistatic polyester film is within 10 ^{7-10 10} Ω / sq.

The antistatic coating composition is water-dispersible consisting of an anionic polyether polyurethane dispersion containing at least one functional group selected from the group consisting of a hydroxyl group, an amine group, an alkyl group and a carboxyl group based on 100 parts by weight of the conductive polymer resin. 100 to 1000 parts by weight of a polyurethane resin, 100 to 1000 parts by weight of any crosslinker resin selected from the group consisting of isocyanate, carbonylimide, oxazoline, epoxy and melamine, and 10 to 100 parts by weight of fluororesin And 0.001 to 1 parts by weight of an acetylene diol-based surfactant.

In addition, the conductive polymer resin is characterized in that the distribution of the particle size of less than 60nm average particle diameter.

In the antistatic coating composition of the present invention, the conductive polymer resin is a water dispersion containing polyanion and polythiophene or a water dispersion containing polyanion and polythiophene derivative.

The antistatic polyester film of the present invention has a change in antistatic properties before and after washing the surface of the organic solvent selected from the group consisting of ethanol, methyl ethyl ketone, toluene and ethyl acetate within a range of 10 ¹ kPa. The initial surface resistance is maintained.

In addition, the antistatic polyester film of the present invention satisfies the peel force of 900g / in or more with the acrylate tape (NITTO # 31B) and the peel force of 150g / 18mm or more with the tape (3M # 244) of the paper material.

The present invention is uniaxially stretched polyester film, and applied to one or both sides of the polyester film by an in-line coating method with an antistatic coating composition containing a conductive polymer resin having an average particle diameter of 60nm or less to form an antistatic layer,

It provides a method for producing an antistatic polyester film to re-stretch the polyester film on which the antistatic layer is formed to produce a biaxially stretched polyester film.

The antistatic coating composition is water-dispersible composed of an anionic polyether polyurethane dispersion containing at least one functional group selected from the group consisting of hydroxyl groups, amine groups, alkyl groups and carboxyl groups based on 100 parts by weight of the conductive polymer resin. 100 to 1000 parts by weight of a polyurethane resin, 100 to 1000 parts by weight of any crosslinker resin selected from the group consisting of isocyanate, carbonylimide, oxazoline, epoxy and melamine, and 10 to 100 parts by weight of fluororesin And 0.001 to 1 parts by weight of an acetylene diol-based surfactant.

At this time, the solid content in the antistatic coating composition is preferably 0.5 to 10 wt%.

The present invention contains a polyurethane resin in the antistatic coating composition to improve the peeling force with the adhesive tape and at the same time to improve the solvent resistance and coating performance by controlling the crosslinking density by using an appropriate crosslinking agent, and the antifouling performance by adding a fluorine resin In particular, by containing a conductive polymer resin having an average particle diameter of 60 nm or less, it is possible to provide an antistatic polyester film having stable antistatic properties and hardly generating antistatic width variation even in an inline coating method.

Accordingly, the antistatic polyester film of the present invention eliminates the main causes of productivity and yield reduction due to variations in the antistatic performance of the coating surface caused by the lateral stretching process in the conventional inline coating, the coating thickness between the width of the film is different. can do.

In addition, the present invention forms an antistatic layer on the one or both sides of the polyester film by the antistatic coating composition for easy control of the coating properties by the inline coating method, the edge portion and the center portion of the antistatic polyester film even in the inline coating method It is possible to provide a method for producing an antistatic polyester film in which antistatic variation of the antistatic agent is hardly generated.

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

The present invention is formed on one side or both sides of the polyester film, an antistatic layer coated with an antistatic coating composition containing a conductive polymer resin by an inline coating method, the antistatic edge portion and the center portion of the antistatic polyester film It provides an antistatic polyester film having a variation in sex of 10% or less.

Specifically, the surface resistance of the edge portion and the center portion of the antistatic polyester film realizes excellent antistatic property of 10 ^{7-10 10} Ω / sq, and the deviation of the antistatic property of the edge portion and the center portion of the film is 10%. It is characterized by the following.

The antistatic coating composition is water-dispersible consisting of an anionic polyether polyurethane dispersion containing at least one functional group selected from the group consisting of a hydroxyl group, an amine group, an alkyl group and a carboxyl group based on 100 parts by weight of the conductive polymer resin. 100 to 1000 parts by weight of a polyurethane resin, 100 to 1000 parts by weight of any crosslinker resin selected from the group consisting of isocyanate, carbonylimide, oxazoline, epoxy and melamine, and 10 to 100 parts by weight of fluororesin And 0.001 to 1 parts by weight of an acetylene diol-based surfactant.

Hereinafter, each composition of the antistatic coating composition of the present invention will be described in detail.

The antistatic coating composition of the present invention is such that the average particle diameter of the conductive polymer resin is distributed to a particle size of 60nm or less, more preferably 20 to 50nm to express a stable antistatic performance. At this time, if the average particle diameter of the conductive polymer resin exceeds 60 nm, the variation in the width of the surface resistance becomes very large, which makes the use of the product difficult.

The particle size of the conductive polymer resin is 20% or less smaller than the conventional conductive polymer resin, and can be used without limitation by conventional means capable of physically miniaturizing the particles, and may use a commercial product that meets the particle size conditions. It may be.

Further, by applying the conductive polymer resin in the form of an aqueous dispersion in which fine particles having an average particle size of 60 nm or less are uniformly dispersed, it is possible to reduce the difference in coating thickness between the film widths during the production of the film by the inline coating method, The antistatic performance deviation can be minimized.

More specifically, in the production of a film by an in-line coating method, a coating process is performed immediately before the first stretching (longitudinal stretching) and the second stretching (transverse stretching), wherein the stretching stress of the center portion and the edge portion in the transverse stretching is different Therefore, a physical property deviation occurs at each position by transverse stretching.

Generally, the edge portion is higher in elongation stress than the central portion, and the coating thickness of the edge portion is thinner. The antistatic property between the center and the edge of the final film is more than 30%. It is possible to obtain an antistatic polyester film having a surface resistance value of 10 ⁷ ? / Sq at the center portion of the film and a surface resistivity value of 10 ¹⁰ ? / Sq at the edge portion and having a deviation of antistatic property between the central portion and the edge portion of 30% There is a problem in productivity and yield deterioration due to difficulty in production of the product.

Thus, in the case of the antistatic coating composition of the present invention, when the coating composition in which the conductive polymer resin having a lower average particle diameter is lowered to 60 nm is uniformly dispersed, the charging between the central portion and the edge portion may be performed even if the stretching is increased due to the improved dispersibility. Since the variation in the prevention property can be minimized to 10% or less, the conventional problem can be solved.

The conductive polymer resin contained in the antistatic coating composition of the present invention is preferably an aqueous dispersion containing a polyanion and a polythiophene or a water dispersion containing a polyanion and a polythiophene derivative use.

In the above description, the polyanion is an acidic polymer, such as a polymeric carboxylic acid or a polymeric sulfonic acid, or polyvinylsulfonic acid. Examples of the polymeric carboxylic acid include polyacrylic acid, polymethacrylic acid, and poly maleic acid, and examples of the polymeric sulfonic acid include polystyrene sulfonic acid and the like.

In the conductive polymer resin of the present invention, it is preferable that the polythiophene or the polythiophene derivative has an excessive amount of the polyanion by weight in terms of solid content, from the viewpoint of imparting conductivity. For example, when 1 wt% of the polythiophene or polythiophene derivative is used, the polyanion is preferably more than 1 wt%, and more preferably 5 wt% or less. More preferably in the range of 1 to 3% by weight. Thus, in the embodiment 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 used, but the present invention is not limited thereto.

To describe the polyurethane resin contained in the antistatic coating composition of the present invention, the polyurethane resin used in the present invention is added to the polyester film to increase the peeling force between the film surface and the tape.

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

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

On the other hand, the amount of the polyurethane resin to be added may be 100 to 1000 parts by weight of the polyurethane resin per 100 parts by weight of the conductive polymer resin. If the addition amount of the polyurethane resin is less than 100 parts by weight, the peeling force with the tape deteriorates and the function can not be exhibited. If the amount exceeds 1000 parts by weight, the peeling force of the tape is sufficiently secured but the antifouling performance and antistatic performance The problem of falling occurs.

The cross-linking agent used in the present invention is used to improve the solvent resistance and film performance of the antistatic layer and the polyester film by controlling the cross-linking density of the cross-linking agent contained in the antistatic coating composition of the present invention. At this time, as the preferable crosslinking agent component, any one or more resins selected from the group consisting of isocyanate-based, carbonylimide-based, oxazoline-based, epoxy-based and melamine-based resins can be used.

On the other hand, the amount of the crosslinking agent to be added may be 100 to 1000 parts by weight of the crosslinking agent resin per 100 parts by weight of the conductive polymer resin. If the amount of the cross-linking agent resin is less than 100 parts by weight, antistatic properties may not be exhibited, and the solvent resistance may be low to cause whitening. On the other hand, if it exceeds 1000 parts by weight, transparency is good, but antistatic properties may be difficult to develop.

In the antistatic coating composition, the fluororesin added to the present invention is added to the polyester film to improve the antifouling property and solvent resistance of the film.

Preferred examples of the fluororesin include tetrafluoroethylene, trifluoroethylene, fluorinated ethylene copolymer propylene, chlorotrifluoroethylene, ethyenetetrafluoroethylene copolymer, chlorotrifluoroethylene , Polytetrafluoroethylene copolymer, polyvinyl fluoride, and polyvinylidene fluoride.

At this time, the amount of the fluororesin to be added may be 10 to 100 parts by weight of the fluororesin, based on 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. On the other hand, if it exceeds 100 parts by weight, the transparency of the film, the peeling strength of the film and the antistatic performance may be deteriorated.

The antistatic coating composition of the present invention is added with a surfactant to improve the stability, wetting and leveling of the coating composition.

Therefore, by containing the acetylenic diol-based surfactant as the surfactant in the antistatic coating composition of the present invention, it is possible to maintain the main coating properties such as peeling force and antifouling property with the adhesive tape while realizing excellent wettability and coating leveling property, It is possible to provide an antistatic polyester film for optical use having a high yield.

The acetylenic diol-based surfactant used in the antistatic coating composition of the present invention is a compound represented by the following formula (1).

Formula 1

(Wherein, R _1, R ₄ is C ₃ ~ C ₁₀ alkyl group in straight or branched chain of, by halogen-substituted alkyl group, a vinyl group, an allyl group, an ethynyl group, a phenyl group, an aryl group, a halogen group, a C ₃ ~ C ₁₀ R ₂ and R ₃ are H or a C ₁ to C ₅ alkyl group, and m, n, p and q are each independently selected from the group consisting of 0 to 20 carbon atoms, It is an integer.)

Thus, in the examples of the present invention, as preferable compounds of the acetylenic diol-based surfactants, 2,5,8,11-tetramethyldodecyne-5,8-diol ethoxysilate (2,5,8,11-Tetramethyl 6 dodecyn-5,8 diol ethoxylate), but is not limited thereto.

That is, the acetylenic diol-based surfactant of the present invention may contain at least one selected from the group consisting of trifluoromethyl, methyl, vinyl, allyl, ethynyl, phenyl, aryl, halogen, An acetylenic diol surfactant containing at least one functional group selected from the group consisting of a carboxyl group can be used.

The acetylene diol surfactant is preferably added in an amount of 0.001 to 1 part by weight based on 100 parts by weight of the total antistatic coating composition. If the addition amount of the surfactant is less than 0.001 parts by weight, the wettability of the coating film is deteriorated. If the amount is more than 1 part by weight, fine bubbles in the coating composition cause coating appearance defects.

The antistatic coating composition of the present invention is preferably prepared so that the solid content is 0.5 to 10.0% by weight based on 100% by weight of the total coating composition, more preferably 1.0 to 5.0% . If the content of the solid content is less than 0.5% by weight, it is not sufficient to exhibit the coating film formation and antistatic function of the coating layer. If the content is more than 10.0% by weight, the transparency of the film is undesirably affected.

On the other hand, the solvent used in the antistatic coating composition is an aqueous coating liquid which is substantially water-based.

Further, for the purpose of improving the coatability and the transparency of the coating composition used in the present invention, it may contain an appropriate organic solvent to the extent that the effect of the present invention is not impaired. Preferred examples of the organic solvent include isopropyl alcohol , Butyl cellosolve, t-butyl cellosolve, ethyl cellosolve, acetone, ethanol, methanol and the like can be used.

However, when a large amount of an organic solvent is contained in the coating composition, there is a risk of explosion in the drying, stretching and heat treatment processes when the coating composition is applied to the in-line coating method. Therefore, the content thereof is preferably 10% by weight or less, more preferably 5% %.

The antistatic polyester film of the present invention can optimize the desired properties depending on the specific composition of the antistatic coating composition.

That is, it contains a conductive polymer modified to a particle size of 60 nm or less in average particle size to realize stable antistatic performance, and improves the peeling force with adhesive tape by containing polyurethane resin and at the same time contains an appropriate crosslinking agent to control the crosslinking density. It is possible to improve solvent resistance and coating performance, improve antifouling performance by containing fluorine resin, and improve the wettability of the coating composition due to the addition of an acetylene diol-based surfactant.

Therefore, the antistatic polyester film of the present invention is excellent in transparency and antistatic properties, in particular, due to the characteristics of the conductive polymer modified to a particle size of 60nm or less of the average particle diameter can prevent the variation between the antistatic properties.

More specifically, the antistatic polyester film of the present invention is transparent and has a surface resistance in the range of 10 ⁷ to ^{10 10} Ω / sq in the characteristics of the coated surface, and in the group consisting of ethanol, methyl ethyl ketone, toluene and ethyl acetate as any of a before and after anti-static change within the range of 10 ¹ Ω castle washed with an organic solvent selected, it maintains the initial surface resistance, has excellent solvent resistance, an antistatic agent in the antistatic layer is not dissolved or eliminated.

In addition, since the antistatic polyester film of the present invention exhibits a water contact angle of 85 degrees or more, it has an excellent antifouling performance, peelability with an acrylate adhesive tape (NITTO # 31B) of 900 g / 3M # 244) of 150 g / 18 mm or more.

The antistatic polyester film of the present invention, which satisfies the above-mentioned physical properties, can meet a demanding level of physical properties required for enlarging the LCD screen in the future. In addition, the antistatic polyester film of the present invention can be applied to any optical display device selected from the group consisting of a liquid crystal display, a plasma display, a personal digital assistant, and a navigation device.

Further,

1) uniaxially stretching the polyester film;

2) An antistatic layer is applied to one or both surfaces of the polyester film by an in-line coating method with an antistatic coating composition containing a conductive polymer resin having an average particle diameter of 60 nm or less on one or both surfaces of the uniaxially stretched polyester film. Forming; And

3) It provides a method for producing an antistatic polyester film for producing a biaxially stretched polyester by re-stretching the polyester film on which the antistatic layer is formed.

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

The polyester film used in the present invention may be any conventional resin known as a base film to which a conventional antistatic coating is applied without any particular limitation. In the present invention, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate , But it is to be understood that the present invention is not limited thereto.

The polyester film refers to a polyester obtained by polycondensing an aromatic dicarboxylic acid and an aliphatic glycol. The aromatic dicarboxylic acid is obtained by using terephthalic acid, 2,6-naphthalene dicarboxylic acid or the like, As the dicarboxylic acid component, there can be used isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalene dicarboxylic acid, adipic acid, sebacic acid, oxycarboxylic acid (for example, P-oxybenzoic acid). The aliphatic glycols include ethylene glycol, diethylene glycol, 1,4-cyclohexanedimethanol, propylene glycol, butanediol, neopentyl glycol, and the like, and these dicarboxylic acid components and glycol components are each two kinds. You may use together the above.

Typical examples of the polyester film include polyethylene terephthalate (PET), polyethylene-2,6-naphthalene dicarboxylate (PEN), and copolymers containing the third component in the polyester.

The polyester resin having the above-mentioned constitution was vacuum-dried, melted by an extruder, extruded into a sheet through a T-die (DIE), adhered to the casting drum by electrostatic application (pinning) The uniaxially stretched polyester film is obtained by obtaining a polyester sheet and uniaxially stretching it at 2.5 to 4.5 times in the roll heated to a temperature not lower than the glass transition temperature of the polyester resin by the difference in the peripheral speed between the roll and the roll.

In the method for producing an antistatic polyester film of the present invention, step 2 is a step of forming an antistatic layer by applying the antistatic coating composition of the present invention on one side or both sides of the uniaxially stretched polyester film in the first step. More specifically, the antistatic coating composition may be applied by a Meyer bar method, a gravure method, or the like, and a polar group may be introduced onto the surface of the film before coating to improve adhesion between the coating layer and the film Or a corona discharge treatment may be performed to improve the coating property.

At this time, the antistatic coating composition of the present invention is the same as that described in the above-mentioned antistatic polyester film, and a detailed description thereof will be omitted.

In the two-step antistatic coating composition of the present invention, control of the coating properties is easy depending on each composition and content. In particular, an antistatic coating composition containing a conductive polymer resin having an average particle diameter of 60 nm or less forms an antistatic layer on one or both sides of the polyester film by an inline coating method, thereby preventing the antistatic edge portion and the center of the antistatic polyester film. With a sex variation of 10% or less, an antistatic polyester film that hardly occurs can be produced.

In the method for producing an antistatic polyester film of the present invention, Step 3 is a step for re-stretching a polyester film formed with an antistatic layer in Step 2 to prepare a biaxially stretched polyester film.

At this time, the stretching in the third step is stretched in the direction perpendicular to the direction of uniaxial stretching, and the preferred stretching ratio is 3.0 to 7.0 times. After the stretching step, the antistatic polyester film can be produced through heat fixation, curing, drying and the like.

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

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

This embodiment is intended to illustrate the present invention in more detail, and the scope of the present invention is not limited to these examples.

≪ Example 1 >

Step 1: Production of uniaxially stretched polyester film

A polyethylene terephthalate pellet having an intrinsic viscosity of 0.625 dl / g containing 20 ppm of amorphous spherical silica particles having an average particle diameter of 2.5 μm was thoroughly dried at 160 ° C. for 7 hours by using a vacuum drier, - An amorphous undrawn sheet was made by adhering it to the cooling drum through a die by electrostatic application, and the amorphous undrawn sheet was heated again and stretched 3.5 times in the film advancing direction at 95 캜 to prepare a uniaxially stretched polyester film. Thereafter, the film surface to be coated was subjected to a corona discharge treatment to produce a polyester film.

Step 2: Production of biaxially stretched polyester film

An aqueous dispersion containing a conductive polymer resin (0.5% by weight of poly3,4-ethylenedioxythiophene) and 0.8% by weight of polystyrenesulfonic acid (molecular weight Mn = 150,000) having a mean particle size distribution of 35 ± 5 nm as a solid on the corona treated surface. ) 100 parts by weight, polyurethane resin (polyether polyurethane dispersion of anion containing a hydroxy group) 200 parts by weight, 200 parts by weight of epoxy crosslinking agent (SPRIX TECHNOLOGY, CK-7B), fluororesin (Dupont, ZONYL) ) 100 parts by weight and 0.1 parts by weight of 2,5,8,11-tetramethyl 6dodecine-5,8 diol ethoxysilate as an acetylene diol-based surfactant was mixed with water to prepare an antistatic coating solution. At this time, the solid content was set to be 1.5% by weight based on the total antistatic coating solution. The antistatic coating liquid was applied to the monoaxial polyester film prepared in the step 1 using a gravure roll. After coating, the coating liquid applied at a temperature of 105 to 140 캜 in a tenter section was dried, stretched 3.8 times in the direction perpendicular to the film advancing direction, and heat-treated at 240 캜 for 4 seconds to give a 38 탆 thick biaxially oriented antistatic polyester film .

<Example 2>

100 parts by weight of a conductive polymer resin (an aqueous dispersion containing 0.5% by weight of poly3,4-ethylenedioxythiophene and 0.8% by weight of polystyrenesulfonic acid (molecular weight Mn = 150,000)) having an average particle size distribution of 35 ± 5 nm, and a polyurethane resin (Polyether Polyurethane Dispersion of Anion Containing a Hydroxy Group) 400 parts by weight, 200 parts by weight of an epoxy crosslinking agent (Sprix Technologies, CR-5L), 150 parts by weight of a fluororesin and 2,5,8,11-tetra 0.15 parts by weight of methyl 6dodecine-5,8 diol ethoxysilate was mixed with water to prepare an antistatic coating solution, and the same procedure as in Example 1 except that the total solid content was prepared to be 2.0% by weight. To produce a biaxially stretched antistatic polyester film.

<Example 3>

100 parts by weight of a conductive polymer resin (an aqueous dispersion containing 0.5% by weight of poly3,4-ethylenedioxythiophene and 0.8% by weight of polystyrenesulfonic acid (molecular weight Mn = 150,000)) having an average particle size distribution of 55 ± 5 nm, and a polyurethane resin (Polyether Polyurethane Dispersion of Anion Containing a Hydroxy Group) 400 parts by weight, 200 parts by weight of an epoxy crosslinking agent (Sprix Technologies, CR-5L), 150 parts by weight of a fluororesin and 2,5,8,11-tetra 0.15 parts by weight of methyl 6dodecine-5,8 diol ethoxysilate was mixed with water to prepare an antistatic coating solution, and the same procedure as in Example 1 except that the total solid content was prepared to be 2.0% by weight. To produce a biaxially stretched antistatic polyester film.

&Lt; Comparative Example 1 &

A biaxially stretched antistatic polyester film was produced in the same manner as in Example 1 except that the conductive polymer resin having an average particle diameter distribution of 100 ± 10 nm was contained.

Comparative Example 2

A biaxially stretched antistatic polyester film was produced in the same manner as in Example 1, except that the composition of the antistatic coating solution did not contain a fluorine resin.

&Lt; Comparative Example 3 &

A biaxially stretched antistatic polyester film was produced in the same manner as in Example 1, except that the polyurethane resin was not contained in the composition of the antistatic coating liquid.

&Lt; Comparative Example 4 &

A biaxially stretched antistatic polyester film was prepared in the same manner as in Example 1 except that the acetylene diol-based surfactant was not contained in the composition of the antistatic coating solution.

&Lt; Comparative Example 5 &

A biaxially stretched antistatic polyester film was prepared in the same manner as in Example 1 except that 1.5 parts by weight of the acetylene diol-based surfactant was contained in the composition of the antistatic coating solution.

<Experimental Example>

About the antistatic polyester film manufactured in Examples 1-2 and Comparative Examples 1-5, the following physical property was evaluated and the result was shown in Table 1 .

1. Water contact angle

Water contact angle was measured by the sessile drop method with purified water obtained by distilling ion-exchanged water using a contact angle measuring instrument (Kyowa Interface Science Co., Ltd .; model name Dropmaster 300), and measuring five times at different positions. After that, an average value was taken.

2. Antistatic property

Using an antistatic measuring instrument (Mitsubishi Co., Ltd .; model name MCP-T600), the sample was installed under the environment of temperature of 23 ℃ and humidity of 50% RH, and then applied to the edge and center of the film according to JIS K7194. The surface resistance to was measured.

3. Ethanol Resistance

Ethanol was soaked in a cloth (BEMCOT, manufactured by ASAHI KASEI FIBER CO., LTD.), And the coated film surface was reciprocated 10 times under a load of 0.5 kg, and the state of the coated surface was evaluated according to the following criteria.

○: When the change of antistatic property is within the range of 10 ¹ Ω

?: The change in antistatic property was increased by 10 ¹ or more and less than 10 ¹¹ ?

X: When the change in antistatic property exceeds 10 ¹¹ Ω

4. Peel force with tape-1

(Nitto Co NITTO # 31B tape width: 20 mm) was applied to the coated surface of the film obtained above using an apparatus for peeling force measurement (AR1000 manufactured by Chemical Machinery Co., Ltd.) under the atmosphere of 23 ° ± 3 and 50 ± 5% 25 mm) was attached thereto, followed by one round of pressing and pressing with a rubber roller having a load of 2 kg for one hour, followed by peeling at 180 degrees at a peeling speed of 0.3 MPM. At this time, the obtained peel force value was measured.

5. Peel force with tape-2

A paper adhesive tape (3M tape No. 244, width: 18 mm) was applied to the coated surface of the film obtained above using a peel force measuring device (AR1000, manufactured by Chemical Machinery Co., Ltd.) under the atmosphere of 23 ° ± 3 and 50 ± 5% After being stuck, it is pressed once by reciprocating with a rubber roller having a load of 2 kg, left for 1 hour, and peeled 180 degrees at a peeling speed of 0.3 MPM. At this time, the obtained peel force value was measured.

6. Coating appearance

When the coated surface of the film obtained from the Xingyi was visually observed by using various light sources such as fluorescent lamps, halogen, and incandescent lamps, the size and number of the uncoated portions were evaluated according to the following criteria.

The area of the uncoated area exceeded 1 mm x 3 mm and the inspection area was 1 m2.

◎: 0 to 1

○: 2 to 3

?: 4 to 10

×: exceeding 10

As can be seen from Table 1, in the case of Comparative Example 1 in which the conductive polymer resin having a large average particle diameter was distributed in the antistatic coating composition, it was confirmed that a large variation in surface resistance between the edge portion and the center portion occurred.

Moreover, in the case of the comparative example 2 which does not contain a fluororesin, since the contact angle value showed the result of remarkably low, desired antifouling performance was not acquired, In the case of the comparative example 3 which does not contain a polyurethane resin, peeling with the said tape From the force results, it was confirmed that the adhesion of the surface is lowered, in particular, the value of the peel force with a commercially available 3M tape is low, the field applicability is lowered to obtain the desired physical properties.

In the composition of the antistatic coating solution, Comparative Example 4, which does not contain a surfactant, since the coating leveling property and the wettability of the coating film is lowered, it was confirmed that the coating appearance defects are insufficient to implement the excellent quality. In addition, in the case of Comparative Example 5 containing an excess of acetylene diol-based surfactant, it was confirmed that the result is insufficient to implement the optimum coating appearance quality.

On the other hand, the average particle diameter of the conductive polymer resin is distributed to a size 20% smaller than the average particle size, and the antistatic layer is formed by using an antistatic coating solution containing a fluororesin and an acetylene diol-based surfactant in a polyurethane resin and an appropriate crosslinking agent. The polyester films prepared in Examples 1 to 2 were transparent, but the surface resistance of the coated surface was realized in the range of 10 ⁷ to ^{10 10} Ω / sq.

In particular, the antistatic property between the edge portion and the center portion of the produced polyester film is hardly generated at less than 10%, and the antistatic property is changed even after wiping the surface with an organic solvent such as ethanol, methyl ethyl ketone, toluene or ethyl acetate. Since it is maintained within the range of 10 ¹ kPa, it was confirmed that excellent solvent resistance that the antistatic agent of the antistatic layer is not dropped or dissolved. In addition, since the water contact angle is more than 85 degrees, it has excellent antifouling performance, and the peeling force with the high adhesive acrylate adhesive tape (NITTO # 31B) satisfies the level of 1,000 g / in, and at the same time, the relatively low adhesive force The peeling force with the adhesive tape (3M # 244) made of paper also satisfies 150g / 18mm or more. Thus, the present invention can provide a polyester film of excellent quality with low surface tension and excellent wetting performance.

As described above,

First, the present invention contains a conductive polymer resin with an average particle diameter of 60nm or less to implement a stable antistatic performance, by containing a polyurethane resin to improve the peel strength with the adhesive tape and at the same time contain a suitable crosslinking agent to control the crosslinking density It provides an antistatic coating composition that improves the coating properties and the coating properties, and improves the antifouling performance by containing a fluororesin, and can improve the coating properties by applying an acetylene diol-based surfactant.

Second, the present invention has a stable antistatic property by forming an antistatic layer by the in-line coating method on the one or both sides of the polyester film, the composition containing the antistatic coating composition, in particular, a conductive polymer resin having an average particle diameter of 60nm or less, While providing an antistatic polyester film with little variation in antistatic width between inline coating methods.

Third, the production method of the antistatic polyester film of the present invention in the conventional inline coating, the coating thickness between the width of the film by the lateral stretching process is different and the productivity and yield decrease due to the antistatic performance variation of the coating surface caused by this The cause was eliminated.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims. .

Claims (10)

In the antistatic polyester film in which the antistatic coating composition containing the conductive polymer resin on one side or both sides of the polyester film is formed by the inline coating method,
The conductive polymer resin is an aqueous dispersion containing polyanions and polythiophenes uniformly dispersed into fine particles having an average particle diameter of 60 nm or less, or an aqueous dispersion containing polyanions and polythiophene derivatives,
The surface resistance of the edge portion and the center portion of the antistatic polyester film is 10 ^{7-10 10} Ω / sq, and the antistatic property of the edge portion and the center portion of the film from the surface resistance value is less than 10% Polyester film. delete The method of claim 1 wherein the antistatic coating composition
100 to 1000 weight of water-dispersible polyurethane resin which consists of an anionic polyether polyurethane dispersion containing at least 1 functional group selected from the group which consists of a hydroxyl group, an amine group, an alkyl group, and a carboxyl group with respect to 100 weight part of conductive polymer resins. Part, isocyanate-based, carbonylimide-based, oxazoline-based, 100-1000 parts by weight of any crosslinker resin selected from the group consisting of melamine-based, 10-100 parts by weight of fluororesin and acetylene diol-based surfactant 0.001 The said antistatic polyester film characterized by the above-mentioned. delete delete The method of claim 1, wherein either one of the antistatic sex change after the before and washed with the organic solvent selected for the surface of the antistatic polyester film in the group consisting of ethanol, methyl ethyl ketone, toluene and ethyl acetate 10 ¹ Ω The antistatic polyester film, characterized in that within the range. The antistatic polyester film of claim 1, wherein the antistatic polyester film satisfies a peel force of at least 900 g / in with an acrylate tape (NITTO # 31B) and a peel force of at least 150 g / 18 mm with a paper material tape (3M # 244). The antistatic polyester film characterized in that. In one or both sides of the polyester film, in the method for producing an antistatic polyester film formed by forming an antistatic layer by coating an antistatic coating composition containing a conductive polymer resin by an in-line coating method,
The polyester film was uniaxially stretched,
In-line antistatic coating composition containing conductive polymer resin of polyanion and polythiophene-dispersed water dispersion or polyanion and polythiophene-derived water dispersion uniformly dispersed into fine particles with an average particle diameter of 60 nm or less It is applied to one or both sides of the polyester film by a coating method to form an antistatic layer,
The method for producing an antistatic polyester film for re-stretching the polyester film on which the antistatic layer is formed to produce a biaxially stretched polyester film. The method of claim 8, wherein the antistatic coating composition
100 to 1000 weight of water-dispersible polyurethane resin which consists of an anionic polyether polyurethane dispersion containing at least 1 functional group selected from the group which consists of a hydroxyl group, an amine group, an alkyl group, and a carboxyl group with respect to 100 weight part of conductive polymer resins. Part, isocyanate-based, carbonylimide-based, oxazoline-based, 100-1000 parts by weight of any crosslinker resin selected from the group consisting of melamine-based, 10-100 parts by weight of fluororesin and acetylene diol-based surfactant 0.001 It is an aqueous solution containing -1 weight part, The manufacturing method of the said antistatic polyester film characterized by the above-mentioned. The method of claim 8, wherein the solid content in the antistatic coating composition is 0.5 to 10% by weight.