KR101619358B1 - Anti static polyester adhesive film for improving water-proofing - Google Patents

Abstract

The present invention relates to an antistatic polyester film excellent in water resistance. More specifically, the present invention relates to an antistatic polyester film which is free from coloring due to an antistatic agent, does not deteriorate in water resistance even after forming a primer layer, has a short drying time, And an antistatic polyester film excellent in water resistance that does not peel off in a high temperature or high humidity environment after forming a primer layer on a base film. To this end, the antistatic polyester adhesive film excellent in water resistance according to the present invention is a base film, which comprises a biaxially oriented polyester film having a thickness of 50-300 탆 and a polymer layer formed on at least one side of the base film as a bonding layer Wherein the surface on which the primer layer is formed has an electrostatic chargeability of ¹⁰ < ¹⁰ > / m < 2 > or less and a static chargeability of 10 < ¹¹ >

Polyester film, antistatic property, water resistance, adhesive film

Description

[0001] The present invention relates to an antistatic polyester film having excellent water resistance,

The present invention relates to an antistatic polyester film excellent in water resistance. More specifically, the present invention relates to an antistatic polyester film which is free from coloring due to an antistatic agent, does not deteriorate in water resistance even after forming a primer layer, has a short drying time, And an antistatic polyester film excellent in water resistance that does not peel off in a high temperature or high humidity environment after forming a primer layer on a base film.

In general, biaxially oriented polyesters for flat display materials, which are used in adhesive films, in particular, polyethylene terephthalate, are required to exhibit structural stability and excellent chemical properties, physical properties, thermal properties, mechanical properties, solvent resistance, durability, And is widely used in various industrial fields such as a magnetic recording medium, a capacitor, an electric and electronic parts material, a packaging material, a photographic material, various medical and industrial fields.

Despite these advantages, however, the problem of static electricity, which is a disadvantage of all polymer films, is not an exception, and it is a serious problem not only in terms of quality but also in safety due to foreign matter adhesion, sparking, electric shock, etc. during manufacturing or processing.

In order to solve such static electricity problems, various methods of imparting antistatic properties have been used. Examples thereof include an internal addition method using an organic sulfonate or an organic phosphate, a method of depositing a metal compound, a method of applying conductive inorganic particles, A method of applying an anionic or cationic compound, and the like.

In the case of a conventional antistatic agent, Japanese Patent Application Laid-Open No. 10-330650 discloses a coating agent which forms a coating film having antistatic property even when the antistatic agent is transparent and the humidity is not high. The coating material contains sulfonated polyaniline as an antistatic agent and a water-soluble or water-dispersible polymer in a mixed solvent of water and a water-soluble organic solvent. According to this, although a transparent antistatic coating can be easily formed on the surface of the plastic or film, there may be a slight coloring due to the sulfonated polyaniline, and there may be a disadvantage that the water-dispersible polymer deteriorates the water resistance. Japanese Patent Application No. 2000-253289 discloses an electroconductive polymer comprising a conductive polymer comprising poly (3,4-dioxythiophene) and a polyanion, a water-soluble compound having an amide group or hydroxyl group at room temperature and a self-emulsifying polyester Polyester resin aqueous dispersion in a specific ratio to a composition obtained by blending a specified amount of an alkoxysilane having an epoxy group in a composition obtained by adding a water-dispersible polyester resin to a composition obtained in a specific ratio. Such a composition is said to improve transparency, conductivity, solvent resistance, and water resistance. However, it takes time to evaporate moisture during drying using a polyester resin aqueous dispersion, and there is a risk of deterioration during storage due to reactivity with moisture of the alkoxysilane. Korean Patent No. 0430989 discloses a quick-drying transparent conductive coating liquid composition. According to Korean Patent No. 0430989, the conductive coating liquid composition is composed of a non-aqueous acrylic polymer binder solution, a conductive polymer aqueous solution and a solvent, and forms a conductive film having excellent water resistance, conductivity and transparency within a short time at about 50 ° C . Such a conductive film can improve the drying time and the water resistance because the evaporation time of the water can be shortened and the hydrophobicity can be increased by using the non-aqueous acrylic polymer binder instead of the silica sol or the water-soluble binder. However, when exposed to a high temperature or high humidity environment for a long time, there is a problem that peeling of the coating layer occurs or the surface conductivity is reduced, and it is difficult to withstand a wet heat durability test required for a material such as LCD or PDP.

Disclosure of the Invention The present invention has been made to solve such problems as described above. It is an object of the present invention to provide an antistatic agent which is free from coloration due to an antistatic agent and does not deteriorate water resistance even after forming a primer layer, And an antistatic polyester adhesive film which does not peel off in a high temperature or high humidity environment after the primer layer is formed on the base film and is excellent in water resistance.

These and other objects and advantages of the present invention will become more apparent from the following description of a preferred embodiment thereof.

The object of the present invention can be attained by providing a biaxially oriented polyester film having a thickness of 50 to 300 占 퐉 and a primer layer as an adhesive layer on at least one surface of the base film, ¹⁰ Ω / m 2 or less and has a static chargeability of 10 ¹¹ Ω / m 2 or less after a 10-min water resistance test at 90 ° C in water. This antistatic polyester is excellent in water resistance.

The primer layer contained 5.0 wt% of an antistatic resin containing 90 wt% of water, 30 wt% of a copolymerization antistatic resin of acrylic monomer and quaternary ammonium salt, 2.0 wt% of a curing agent containing 30 wt% of a polyethyleneimine curing agent 2.0% by weight of a silica particle or alumina-silica composite oxide particle dispersion containing 70% by weight of silica particles or alumina-silica composite oxide particles, 1.0% by weight of an anionic surfactant aqueous dispersion containing 10% by weight of an anionic surfactant % By weight of the coating liquid.

Preferably, the surface of the base film on which the primer layer is formed has a total light transmittance of 90% or more and a haze value of 0.4 to 1.0%.

Preferably, the adhesive force between the base film and the primer layer is 100% after a 96-hour moisture resistance test at 65 ° C and 95% humidity.

Preferably, the primer layer is applied after uniaxial stretching of the biaxially oriented polyester base film.

According to the present invention, there is no coloring by the antistatic agent, the water resistance does not deteriorate even after the primer layer is formed, the drying time is short, there is no risk of deterioration during storage, and after the primer layer is formed on the base film, Peeling does not occur in a high humidity environment, and excellent effects such as high optical properties and excellent appearance characteristics are obtained.

Further, the present invention can increase the product yield by increasing the adhesion with resin used for post-processing such as prism lens processing, hard coat processing, and AR processing.

In addition, the present invention can be used throughout the various optical members due to its high transmittance and small haze value. Particularly, as optical films, base films for prism sheets used for LCDs, base films for backlights, It is useful as a coating film, a base film for AR film, a protective film for CRT, and the like.

Hereinafter, the present invention will be described in detail with reference to embodiments and drawings of the present invention. It will be apparent to those skilled in the art that these embodiments are provided by way of illustration only for the purpose of more particularly illustrating the present invention and that the scope of the present invention is not limited by these embodiments .

1 is a cross-sectional view of an antistatic polyester adhesive film excellent in water resistance according to the present invention.

An antistatic polyester adhesive film excellent in water resistance according to the present invention is a base film which comprises a biaxially oriented polyester film having a thickness of 50-300 占 퐉 and a primer layer as a bonding layer of a polymer on at least one side of the base film, The surface of the primer layer has an electrostatic chargeability of ¹⁰ < ¹⁰ > / m < 2 > or less and a static chargeability of 10 < ¹¹ >

As the base film, a biaxially oriented polyester film may be a known film.

An antistatic polyester excellent in water resistance according to the present invention is characterized in that a copolymerization antistatic resin of an acrylic monomer and a quaternary ammonium salt is used as a primer layer of the adhesive film. 2 is a chemical formula of the copolymerization antistatic agent of the acrylic monomer and the quaternary ammonium salt used in the present invention.

Further, the polyethyleneimine curing agent used in the primer layer of the present invention, in addition to the melamine or epoxy curing agent normally used, additionally contains a water-sintering functional group in the molecule, thereby increasing the adhesive force with the plastic substrate, Has a function of improving the hardness and also increasing the polar interaction between the resin composition molecules to improve the function of moisture absorption.

The surfactant used in the primer layer of the present invention can be used as a water-soluble coating solution, and can be applied to a base film using a required amount of a known anionic or nonionic surfactant to increase the wettability of the base film and uniformly apply the coating solution .

In the primer layer of the present invention, an additive may be added to the coating liquid for improving the coating property and the function. Examples of such additives include organic particles, inorganic particles, defoaming agents, and the like. According to the present invention, the water-soluble polymer primer layer can contain inorganic particles having a comparatively small refractive index difference with resin to ensure running properties. When the average particle diameter of the inorganic particles used is less than 30 nm, It does not contribute to the running property and scratch resistance of the film, and does not give the effect of fine particle injection. When the average particle size of the fine particles exceeds 500 nm, there arises a problem that the haze is obstructed. Accordingly, the size of the inorganic particles according to the present invention has a particle size in the range of 30 to 500 nm, more preferably 50 to 300 nm. For example, silica particles or alumina-silica composite oxide particles are preferably used.

The primer layer of the adhesive film according to the present invention is characterized in that the primer layer of the adhesive film comprises 5.0 wt% of an antistatic resin containing 90 wt% of water, 30 wt% of a copolymerization antistatic resin of an acrylic monomer and a quaternary ammonium salt, 2.0% by weight of a curing agent containing 30% by weight of an imine curing agent, 2.0% by weight of a silica particle or an alumina-silica composite oxide particle aqueous dispersion containing silica particles or 70% by weight of alumina-silica composite oxide particles, an anionic surfactant And 1.0 wt% of an anionic surfactant aqueous dispersion solution containing 10 wt% of an anionic surfactant.

The surface of the base film (the surface of the base film on which the primer layer is formed) of the adhesive film of the antistatic polyester excellent in water resistance according to the present invention has a total light transmittance of 90% or more and a haze value of 0.4 to 1.0% , And the adhesive force between the base film and the primer layer is 100% after 96 hours of humidity test at 65 ° C and 95% humidity. This is because if the adhesive strength is poor compared to the conventional product, the product can not be applied.

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

[Example 1]

First, the polyethylene terephthalate resin pellets were dried under reduced pressure (1.3 hPa) at 135 캜 for 6 hours, then fed to an extruder, melt extruded at about 280 캜 into a sheet, and dried on a metal roll Quenched and solidified to obtain a casting film having a thickness of 1925 탆. Next, this casting film was heated to 100 DEG C in a heated roll group and an infrared heater, and then stretched at a 3.2-fold stretching ratio in the longitudinal direction by a roll group having a peripheral speed to obtain a uniaxially oriented PET film, Respectively. The coating solution for forming the primer layer was coated on one side of the uniaxially oriented PET film by a reverse roll method and dried. Subsequently, the film was gripped at the end with a clip, introduced into a hot air region, and dried. Thereafter, stretching was carried out at 130 占 폚 in the transverse direction at 3.2 times the stretching ratio, followed by heat setting at 240 占 폚, and then lateral relaxation at 3 占 폚 at 200 占 폚. Thus, an adhesive biaxially oriented polyester film for optical use having a thickness of 188 mu m was obtained.

In Example 1, in the film formation of the biaxially oriented polyester film, the optical biaxially oriented polyester film having a thickness of 188 μm after film formation was coated on the adhesive film by the following method and then applied to obtain a water resistance An optical biaxially oriented polyester film having an improved function was obtained.

The coating liquid for the adhesive layer forming the primer layer contained 5.0 wt% of antistatic resin containing 90 wt% of water, 30 wt% of copolymerization antireflection resin of acrylic monomer and quaternary ammonium salt, 30 wt% of polyethyleneimine curing agent 2.0% by weight of a curing agent which is an anionic surfactant, 2.0% by weight of a silica particle or an alumina-silica composite oxide particle aqueous dispersion containing silica particles or alumina-silica composite oxide particles in an amount of 70% by weight and an anionic surfactant in an amount of 10% 1.0% by weight of an activator aqueous dispersion was added and dispersed to prepare a coating liquid.

[Example 2]

The coating liquid was prepared in the same manner as in Example 1 except that the thickness of the casting film was 2200 탆 and the thickness of the film after the film formation was 250 탆 in the biaxially oriented polyester film.

[Comparative Example 1]

In Comparative Example 1, in the film of the biaxially oriented polyester film of Example 1, an optical biaxially oriented polyester adhesive film having a thickness of 250 mu m after film formation was prepared by applying a coating solution by the following method Optical biaxially oriented polyester This adhesive film was obtained.

The coating liquid for the adhesive layer forming the primer layer contained 95% by weight of water, 2.0% by weight of a curing agent containing 30% by weight of a polyethyleneimine curing agent, and silica containing 70% by weight of silica particles or alumina- 2.0% by weight of a particulate or alumina-silica composite oxide particle aqueous dispersion, and 1.0% by weight of an anionic surfactant aqueous dispersion containing 10% by weight of an anionic surfactant were added and dispersed to prepare a coating liquid.

[Comparative Example 2]

In Comparative Example 2, in the film formation of the biaxially oriented polyester film of Example 1, the optical biaxially oriented polyester film having a thickness of 250 mu m after film formation was applied to the adhesive film by the following method, The biaxially oriented polyester obtained was an adhesive film.

The coating liquid for the adhesive layer forming the primer layer contained 2.0% by weight of an antistatic resin containing 30% by weight of 93% by weight of water, a copolymerization antireflection resin of an acrylic monomer and a quaternary ammonium salt, and 30% by weight of a polyethyleneimine curing agent 2.0% by weight of a curing agent which is an anionic surfactant, 2.0% by weight of a silica particle or an alumina-silica composite oxide particle aqueous dispersion containing silica particles or alumina-silica composite oxide particles in an amount of 70% by weight and an anionic surfactant in an amount of 10% 1.0% by weight of an activator aqueous dispersion was added and dispersed to prepare a coating liquid.

[Comparative Example 3]

In Comparative Example 3, in the film formation of the biaxially oriented polyester film of Example 1, an optical biaxially oriented polyester adhesive film having a thickness of 250 mu m after film formation was prepared by applying a coating solution in the following manner, The biaxially oriented polyester obtained was an adhesive film.

The coating liquid for the adhesive layer forming the primer layer contained 7.0% by weight of antistatic resin containing 30% by weight of 88% by weight of water, copolymerization antistatic resin of acrylic monomer and quaternary ammonium salt, 30% by weight of polyethyleneimine curing agent 2.0% by weight of a curing agent which is an anionic surfactant, 2.0% by weight of a silica particle or an alumina-silica composite oxide particle aqueous dispersion containing silica particles or alumina-silica composite oxide particles in an amount of 70% by weight and an anionic surfactant in an amount of 10% 1.0% by weight of an activator aqueous dispersion was added and dispersed to prepare a coating liquid.

[Experimental Example 1]

The coating appearance of the films prepared in Examples 1 to 2 and Comparative Examples 1 to 3 was measured. Fluorescent lamps and three wavelengths of light were used to measure the coating state of the prepared coating solution by visually dividing into upper / middle / lower portions.

[Experimental Example 2]

The adhesion between the substrate and the primer layer of the films prepared in Examples 1 to 2 and Comparative Examples 1 to 3 was measured. Using a # 4 wire bar, a cellulose adhesive test sample is coated on the surface to which the primer layer is adhered, and dried at 150 캜 for 30 seconds in a drying oven. Cutting lines are then made on the film coated with the primer layer with a cutter, and 2 mm x 2 mm squares are placed in a 10 x 10 matrix. The cutting line is deep enough to pass through the adhesive layer to reach the substrate film. Attach cellophane tape (No. 405, made by NICHIBAN; width: 24 mm) to the film with the cutting line and rub the tape with velvet and attach it strongly to the film. Then, remove the tape vertically. The area of the primer layer remaining on the adhesive layer was visually observed, and the adhesive force was calculated by the following equation.

The adhesive strength test for evaluation of moisture resistance after 96 hours at 65 占 폚 and 95% humidity was also carried out in the same manner as described above.

[Experimental Example 3]

The electrostatic chargeability of the films prepared in Examples 1 to 2 and Comparative Examples 1 to 3 was measured. The measurement film was allowed to stand for 24 hours under conditions of 23 ° C and a relative humidity of 50%, and the surface resistance was measured by applying a voltage of 500 V using a model R-503, a surface resistance meter of Kawaguchi Co.,

[Experimental Example 4]

The films prepared in Examples 1 to 2 and Comparative Examples 1 to 3 were immersed for 10 minutes and then the film was dried using a dryer. Using a model R-503 manufactured by Kawaguchi Co., Ltd., The surface resistance was measured by applying an applied voltage of 500V.

[Experimental Example 5]

Optical properties of the coating solutions used in the films prepared in Examples 1 to 2 and Comparative Examples 1 to 3 were measured. The optical properties were measured by dividing the total transmittance and Hz by a method commonly used in the art.

The results of Experimental Examples 1 to 5 are shown in Table 1 below.

[Table 1]

division PET thickness
(탆) Coating Appearance
(Upper / middle / lower) Adhesion
(%) Electrostatic chargeability
(Ω / ㎡) Water resistance
Electrostatic chargeability
(Ω / ㎡) Optical property
(TT / Hz) Example 1 188 Prize 100 10 ⁸ 10 ⁹ 91.1 / 0.8 Example 2 250 Prize 100 10 ⁸ 10 ⁹ 90.6 / 0.9 Comparative Example 1 250 Ha 0 10 ¹⁴ 10 ¹⁴ 87.0 / 0.3 Comparative Example 2 250 Up / Middle 90 10 ¹¹ 10 ¹² 90.2 / 0.9 Comparative Example 3 250 Ha 100 10 ⁷ 10 ⁸ 91.4 / 1.2

As can be seen from the above Table 1, the examples show that the electrostatic chargeability and the optical characteristics after electrostatic chargeability and water resistance test are excellent as well as the appearance and adhesion of the coating with the substrate as compared with the comparative examples.

However, in the case of Comparative Examples 1 and 3, when the surface of the PET substrate was observed after coating, defective appearance of the coating occurred in the form of stain and the product could not be applied. In the case of Comparative Examples 1 and 2, if the adhesive force is not 100%, the product can not be applied.

Therefore, the antistatic polyester adhesive film excellent in water resistance according to the present invention is free from coloration due to the antistatic agent, does not deteriorate the water resistance even after forming the primer layer, has a short drying time, The present invention is not limited to the prism lens processing, the hard coat processing, the AR process, and the like. Further, since the primer layer is formed on the base film, peeling does not occur in a high temperature or high humidity environment, It is possible to increase the product yield by increasing the adhesion force with the resin used for post-processing such as processing, etc., and can be used throughout the various optical members due to the high transmittance and low haze value. A base film for a prism sheet used for an LCD, a base film for a backlight, a hard coat processing, an AR film In the base film and a CRT may be effective, such as is useful as a protective film.

1 is a cross-sectional view of an antistatic polyester adhesive film excellent in water resistance according to the present invention.

2 is a chemical formula of the copolymerization antistatic agent of the acrylic monomer and the quaternary ammonium salt used in the present invention.

Claims (5)

1. An antistatic polyester adhesive film excellent in water resistance, As the base film, a biaxially oriented polyester film having a thickness of 50 to 300 占 퐉, Wherein a primer layer is formed on at least one surface of the base film as an adhesive layer, the surface of the primer layer has an electrostatic chargeability of 10 ¹⁰ ? / M 2 or less, a static chargeability after 10 minutes of water resistance test at 90 占 폚 water, ¹¹ Ω / m 2 or less, The primer layer contained 5.0% by weight of an antistatic resin aqueous dispersion containing 90% by weight of water, 30% by weight of a copolymerization antistatic resin of an acrylic monomer and a quaternary ammonium salt, 2.0% by weight of a curing agent aqueous dispersion 2.0 containing 30% by weight of a polyethyleneimine curing agent 2.0% by weight of a silica particle or alumina-silica composite oxide particle dispersion containing 70% by weight of silica particles or alumina-silica composite oxide particles, 10% by weight of an anionic surfactant, 1.0% by weight of an anionic surfactant aqueous dispersion Wherein the antistatic polyester film is applied with a coating liquid prepared by adding and dispersing an antistatic agent in an amount of 0.1 to 10 wt%. delete The method according to claim 1, Wherein the surface of the base film on which the primer layer is formed has a total light transmittance of 90% or more and a haze value of 0.4 to 1.0%. The method according to claim 1, Wherein the adhesive force between the base film and the primer layer is 100% after a test of wetting resistance at 65 캜 and 95% humidity for 96 hours. The method according to any one of claims 1, 3, and 4, Wherein the primer layer is applied after uniaxial stretching of the biaxially oriented polyester base film.

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