KR101664317B1 - Polyester adhesive film for improving anti static and water-proofing - Google Patents

Abstract

The present invention relates to an adhesive film having improved antistatic properties and water resistance. More specifically, the present invention relates to an adhesive film which is excellent in antistatic property and does not deteriorate in antistatic property even when a water resistance test is conducted after forming a primer layer, To an adhesive film of polyester which has improved antistatic properties and water resistance which do not cause peeling in a high temperature or high humidity environment even after a primer layer is formed on a substrate. To this end, the polyester adhesive film having improved antistatic properties and water resistance according to the present invention is a biaxially oriented polyester adhesive film having a function of improving the water resistance of the primer layer, and is characterized in that it comprises a base film of a biaxially oriented polyester film A primer layer is formed as an adhesive layer on at least one side of a film and the base film, wherein the surface of the base film has an electrostatic chargeability of 10 ⁷ or less and a static chargeability after 10 minutes water resistance test at 90 占 폚 water is 10 ⁶ Or less.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a polyester film having improved antistatic properties and water resistance,

The present invention relates to an adhesive film having improved antistatic properties and water resistance. More specifically, the present invention relates to an adhesive film which is excellent in antistatic property and does not deteriorate in antistatic property even when a water resistance test is conducted after forming a primer layer, To an adhesive film of polyester which has improved antistatic properties and water resistance which do not cause peeling in a high temperature or high humidity environment even after a primer layer is formed on a substrate.

Generally, polyesters, especially polyethylene terephthalates, are excellent in structural stability, chemical properties, physical properties, thermal properties, mechanical properties, solvent resistance, durability, chemical resistance and electrical insulation properties and are used for magnetic recording media, It is used extensively in all industrial fields such as various medical and industrial fields in addition to component materials, packaging materials and photographic materials.

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 and electric shock during manufacturing or processing. Various methods for imparting antistatic properties have been used in order to solve such problems of static electricity. For example, there have been used methods such as 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 the conventional antistatic agent, according to Japanese Patent Laid-Open Publication No. 1998-330650, the antistatic agent is transparent, and discloses a paint which forms a coating film having antistatic property even when 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. Further, Japanese Patent Application Laid-Open No. 2002-060736 discloses a conductive polymer composition comprising a conductive polymer comprising poly (3,4-dioxythiophene) and a polyanion, a water-soluble compound which is liquid at room temperature and has an amide group or hydroxyl group, Discloses a composition for antistatic coating which is obtained by blending a specified amount of an alkoxysilane having an epoxy group in a composition obtained by blending a polyester resin aqueous dispersion at 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. 10-0430989 discloses a quick-drying transparent conductive coating liquid composition. According to Korean Patent No. 10-0430989, 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, transparency, . 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 moisture and heat durability tests required for materials such as LCD or PDP.

In recent years, antistatic films applied to the inside of a display as a material for electronic materials have undergone a water washing process due to the nature of the manufacturing process. Conventional antistatic agents have a drawback in that their antistatic properties are lost after the water washing process due to their low water resistance. Further, polymeric antistatic agents such as polyvinyl benzyl type, poly (meth) acrylate type, styrene- (meth) acrylate copolymer type, methacrylate methacrylic imide copolymer type cationic or anionic type And the like are known, but these polymer compounds have a problem that water resistance and antistatic property are not sufficient.

Japanese Patent Application Laid-Open No. 1998-330650 Japanese Patent Application Laid-Open No. 2002-060736 Korean Patent No. 10-0430989

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to provide a primer layer which is excellent in antistatic property and which does not deteriorate antistatic property even when a water resistance test is performed after forming a primer layer, It is an object of the present invention to provide a polyester adhesive film having improved antistatic properties and water resistance that do not peel off in a high temperature or high humidity environment even after forming a layer.

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

The above object is achieved by a biaxially oriented polyester adhesive film having a function of improving the water resistance of a primer layer, comprising: a base film of a biaxially oriented polyester film having a thickness of 50 to 300 占 퐉; but form a primer layer, the surface of the primer layer is electrostatic charging property is 10 ⁷ Ω / ㎡ or less, the antistatic performance, characterized in that from 90 ℃ water 10 minutes water resistance electrostatic charging property is 10 ⁶ Ω / ㎡ or less after testing A polyester having improved water resistance is achieved by an adhesive film.

Here, the primer layer comprises 5.0 to 9.0% by weight of an antistatic resin aqueous dispersion containing 10% by weight of an antistatic agent in which polyurethane-based monomers and carbon nanotubes are dispersed, a curing agent aqueous dispersion 1.0 containing 30% by weight of a polyethyleneimine curing agent To 5.0% by weight of silica particles or 0.1 to 3.0% by weight of silica particles or alumina-silica composite oxide particle aqueous dispersion containing 70% by weight of silica particles or alumina-silica composite oxide particles, 10% by weight of an anionic surfactant, 0.1 to 3.0% by weight of an active agent water dispersion and a balance of water.

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.

More preferably, the primer layer is applied after uniaxially stretching the biaxially oriented polyester film.

According to the present invention, the primer layer used in the biaxially stretched polyester film has not only sufficient adhesion with the base material but also effects such as maintaining the charging performance even in a high humidity environment.

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.

1 is a cross-sectional view of a polyester adhesive film having improved antistatic properties and water resistance according to the present invention.

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 a polyester adhesive film having improved antistatic properties and water resistance according to the present invention. The polyester adhesive film having the antistatic property and water resistance improved according to the present invention is a biaxially oriented polyester adhesive film having a function of improving the water resistance of the primer layer. The adhesive film comprises a base film of a biaxially oriented polyester film , A primer layer is formed on at least one surface of the base film as an adhesive layer, and the surface of the primer layer has a static electrification property of 10 ⁷ Ω / m 2 or less and a static electrification property of 10 ⁶ Ω / m 2 or less.

Preferably, the primer layer comprises 5.0 to 9.0% by weight of an antistatic resin aqueous dispersion containing 10% by weight of an antistatic agent in which polyurethane-based monomers and carbon nanotubes are dispersed, a curing agent containing 30% by weight of a polyethyleneimine curing agent 1.0 to 5.0% by weight of a dispersion, 0.1 to 3.0% by weight of a silica particle or an alumina-silica composite oxide particle aqueous dispersion containing 70% by weight of silica particles or alumina-silica composite oxide particles, 10% by weight of an anionic surfactant And 0.1 to 3.0% by weight of a surfactant aqueous dispersion and a balance of water. More preferably, the antistatic agent in which the polyurethane-based monomer and the carbon nanotube are dispersed in water preferably has a weight ratio of polyurethane-based monomer to carbon nanotube of 15: 1.

The primer layer of the polyester adhesive film having improved antistatic properties and water resistance according to the present invention is characterized by using an antistatic agent in which a polyurethane-based monomer and carbon nanotubes are dispersed. In the antistatic agent composition of the present invention, The tube may have excellent antistatic properties because it has high electrical conductivity besides excellent thermal and mechanical properties. The carbon nanotube may be selected from single wall carbon nanotubes, double wall carbon nanotubes, multiwall carbon nanotubes, and mixtures thereof The carbon nanotube dispersion solvent used in the solvent dispersion step may be one or more of acetone, methyl ethyl ketone, methyl alcohol, ethyl alcohol, isopropyl alcohol, butyl alcohol, ethylene glycol, polyethylene glycol, tetrahydrofuran, Dimethylformamide, dimethylacetamide, nucleic acid, cyclohexanone, toluene It is preferable to use at least one member selected from the group consisting of chloroform, chloroform, distilled water, dichlorobenzene, dimethylbenzene, trimethylbenzene, pyridine, methylnaphthalene, nitromethane, acrylonitrile, octadecylamine, aniline and dimethylsulfoxide .

The carbon nanotubes used in the present invention are preferably multi-walled carbon nanotubes having an average diameter of 120 nm, a length of 160 μm, and a volume resistivity of 0.1 Ω · cm in a bulk state. Treating the multi-walled carbon nanotubes at 310 ° C. for 2 hours, ultrasonically treating the carbon nanotubes in an acid solution having a sulfuric acid / nitric acid ratio of 3: 1 for 3 hours, , And a step of filtering and drying the carbon nanotubes sufficiently in an oven is preferably dispersed in water. And more preferably by the addition of a dispersant for dispersing the water COOH, OH, COOCH ₃ To introduce a functional group of any one of them to improve the dispersion state. In addition, the carbon nanotubes exhibit high conductivity through a shortened conductive path as the length of the carbon nanotubes is particularly long and the dispersion of the carbon nanotubes in the polymer resin matrix is good, thereby providing excellent antistatic function.

In addition, the polyethyleneimine curing agent of the primer layer according to the present invention further increases the adhesive strength with the plastic substrate by additionally containing a water-sintering synthetic functional group in the molecule as compared with the melamine or epoxy curing agent usually used, And also has a function of increasing the polarity interaction between the resin composition molecules and improving the function of moisture absorption.

Further, the surfactant of the primer layer according to the present invention can be used as an aqueous 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 addition, the primer layer according to the present invention may contain an additive in 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.

In addition, the surface of the primer layer on which the primer layer is formed has an electrostatic chargeability of 10 ⁷ Ω / m 2 or less, and has a water resistance of 10 minutes It characterized in that the electrostatic charging property is 10 ⁶ Ω / ㎡ or less, and further characterized in that the adhesive force between the base film and the primer layer is 65 ℃, 95% 100% after the moisture resistance test 96 hours in a humidity. This is because if the adhesive strength is poor compared to the conventional product, the product can not be applied. Preferably, the primer layer is applied after uniaxially stretching the biaxially oriented polyester film.

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 liquid 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 in Example 1 was prepared by mixing 90 wt% of water, an antistatic resin (polyurethane monomer-carbon nanotube weight ratio of 15: 1) dispersed in polyurethane-based monomer and carbon nanotube, 2.0 wt% of a curing agent aqueous dispersion containing 30 wt% of a polyethyleneimine curing agent (a curing agent having a -NH-C ₂ H ₄ group-containing curing agent, hereinafter the same), 10 wt% of an antistatic resin aqueous dispersion containing 10 wt% 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 (an anionic surfactant containing a florine group, 1.0% by weight of an anionic surfactant aqueous dispersion solution containing a weight% of a surfactant 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 formation of the biaxially oriented polyester film of Comparative Example 1, the optical biaxially oriented polyester film having a thickness of 250 m after film formation was coated on the adhesive film by the following method, A polyester was obtained as an adhesive film.

The coating liquid for the adhesive layer forming the primer layer of Comparative Example 1 contained 93 wt% of water, 2.0 wt% of a resin water dispersion containing 30 wt% of a polyurethane monomer, 30 wt% of a curing agent containing a polyethyleneimine curing agent 2.0% by weight of a dispersion, 2.0% by weight of a silica particle or alumina-silica composite oxide particle aqueous dispersion containing silica particles or 70% by weight of alumina-silica composite oxide particles, and 10% by weight of an anionic surfactant 1.0% by weight of the dispersion was 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 of Comparative Example 2 was prepared by mixing 2.0% by weight of an antistatic resin aqueous dispersion containing 93% by weight of water and 10% by weight of an antistatic resin in which carbon nanotubes were dispersed, 2.0% by weight of a curing agent aqueous dispersion containing 30% by weight, 2.0% by weight of a silica particle or an alumina-silica composite oxide particle aqueous 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 aqueous dispersion of anionic surfactant containing anionic surfactant 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 of Comparative Example 3 contained 10.0% by weight of an antistatic resin aqueous dispersion containing 85% by weight of water, 10% by weight of an antistatic resin in which polyurethane-based monomers and carbon nanotubes were dispersed, 2.0% by weight of a curing agent aqueous dispersion containing 30% by weight of a polyethyleneimine curing agent, 2.0% by weight of a silica particle or alumina-silica composite oxide particle aqueous dispersion containing silica particles or 70% by weight of alumina-silica composite oxide particles, 1.0% by weight of an anionic surfactant aqueous dispersion containing 10% by weight of an activator 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 symbols "o" in Table 1 indicate 90% or more, and "x"

The adhesive strength test for evaluation of moisture resistance after 96 hours at 65 占 폚 and 95% humidity is 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 film was allowed to stand for 24 hours under conditions of 23 DEG C and relative humidity of 50%, and the surface resistance was measured by applying a voltage of 500 V using a surface resistance meter model R8340A of ADVANTEST Co., Ltd., Japan.

[Experimental Example 4]

In the above Examples 1 to 2 and Comparative Examples 1 to 3, the film prepared in water at 90 占 폚 was immersed for 10 minutes, and the measurement film was dried using a dryer. Using a model R8340A manufactured by ADVANTEST Co., Voltage was applied to measure the surface resistance of the primer layer.

The results according to Experimental Examples 1 to 4 are shown in Table 1 below.

division PET
thickness
(탆) Coating Appearance
(Upper / middle / lower) Adhesion
(%) Electrostatic chargeability
(Ω / ㎡) Water resistance
Electrostatic chargeability
(Ω / ㎡) Example 1 188 Prize 100 10 ⁷ 10 ⁶ Example 2 250 Prize 100 10 ⁷ 10 ⁶ Comparative Example 1 250 Prize 100 10 ¹⁴ 10 ¹⁴ Comparative Example 2 250 Prize 80 10 ⁷ 10 ⁶ Comparative Example 3 250 Ha 100 10 ⁶ 10 ⁵

As can be seen from the above Table 1, it can be seen that, in comparison with the comparative examples, the electrostatic chargeability after electrostatic chargeability and water resistance test is maintained as well as the coating appearance and adhesion with the substrate. However, in the case of Comparative Example 1, since the electrostatic chargeability is similar to that of the existing PET surface, the product can not be applied. In the case of Comparative Example 2, if the adhesive force is not 100%, the product can not be applied. In the case of Comparative Example 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.

101: primer layer 102: biaxially oriented polyester film
103: backside layer

Claims (4)

A base film of a biaxially oriented polyester film having a thickness of 50 to 300 mu m, and
Wherein the base film is coated with a composition comprising 5.0 to 9.0% by weight of an antistatic resin aqueous dispersion containing 10% by weight of an antistatic agent in which a polyurethane-based monomer and carbon nanotubes are dispersed in a weight ratio of 15: 1 Comprising a primer layer,
Wherein the surface of the primer layer has an electrostatic chargeability of 10 < ⁷ > / m < 2 > or less and an electrostatic chargeability of 10 < ⁶ & This adhesive film. The method according to claim 1,
The primer layer contains 1.0 to 5.0% by weight of a curing agent aqueous dispersion containing 30% by weight of a polyethylene imine curing agent, silica particles containing 70% by weight of silica particles or alumina-silica composite oxide particles, or 0.1 to 100% by weight of an alumina- To 3.0% by weight of an anionic surfactant, 0.1% to 3.0% by weight of an anionic surfactant aqueous dispersion containing 10% by weight of an anionic surfactant, and a residual amount of water. Polyester adhesive film. The method according to claim 1,
Wherein the adhesive force between the base film and the primer layer is 100% after a wet test in 96 hours at 65 캜 and 95% humidity, wherein the antistatic property and the water resistance are improved. The method according to claim 1,
Wherein the primer layer is applied after uniaxial stretching of the biaxially oriented polyester film, wherein the primer layer is provided with antistatic properties and water resistance.

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