KR101072767B1 - Double-faced adhesive film without base - Google Patents

Abstract

The present invention relates to an inorganic double-sided adhesive film, and more particularly, to an inorganic double-sided adhesive film having antistatic performance and used for laminating and fixing optical films for display elements such as liquid crystal display devices. The inorganic double-sided adhesive film of the present invention includes a first release film, a second release film, and an antistatic adhesive layer provided between the first release film and the second release film, wherein the antistatic adhesive layer is a carboxyl group. Acrylic pressure-sensitive adhesive having; Epoxy curing agents and isocyanate curing agents; Silane coupling agents; And an antistatic agent. When the inorganic double-sided adhesive film of the present invention is used, the optical film can be easily laminated and fixed, and excellent adhesiveness and antistatic performance are generated, so that static electricity is generated when the release film is peeled off or when the optical film is laminated. It is possible to reduce, thereby preventing damage to the optical film and the adhesive layer.

Inorganic materials, antistatic, adhesive layer, double sided adhesive film, optical film fixing

Description

Inorganic double-sided adhesive film {Double-faced adhesive film without base}

The present invention relates to an inorganic double-sided adhesive film, and more particularly, to an inorganic double-sided adhesive film having antistatic performance and used for laminating and fixing optical films for display elements such as liquid crystal display devices.

Conventionally, a method of laminating and fixing an optical film such as a polarizing film or a retardation film, coating a pressure-sensitive adhesive on a release film and immediately laminating it with an optical film, and then aging at a predetermined time or temperature for a crosslinking reaction of the pressure-sensitive adhesive, The method of laminating and fixing the optical film using a double-sided adhesive film was used.

However, in the method of coating the adhesive on the release film and laminating it with the optical film, a polarizing plate manufacturer must separately provide a coating line, and in case of poor coating due to poor coating, it is impossible to rework an optical film such as an expensive polarizing film. I have a problem.

In the case of using a double-sided adhesive film, it is required to go through a separate antistatic agent coating process for imparting antistatic performance to the polarizing plate film, foreign matters due to peeling static electricity generated when the release film is peeled off when a separate antistatic agent coating process is not performed. There is a problem of liquid crystal damage due to mixing problems and static electricity generated when the polarizer panels are stacked.

Accordingly, the present inventors have repeatedly conducted numerous studies and experiments to develop a pressure-sensitive adhesive film which is excellent in charging performance and can be easily laminated and secured to an optical film such as a polarizing film, and has antistatic performance. It came to develop the double-sided adhesive film provided with an adhesive layer.

In the prior art, an adhesive film is prepared in the form of an inorganic double-sided adhesive by imparting a charging performance to the adhesive layer, and an example of applying the same to a lamination of an optical film is not found, and the inventors invented it for the first time.

Accordingly, it is an object of the present invention to provide an inorganic double-sided adhesive film having an adhesive function capable of easily fixing and laminating an optical film with antistatic performance. In particular, it can be used for laminating and fixing optical films in the manufacture of polarizing plates used in liquid crystal display devices, and has good reworking properties, and reduces the lifting and warping of adhesive layers, thereby reducing the reliability of optical films. It is an object of the present invention to provide an inorganic double-sided adhesive film.

In order to achieve the above object, the inorganic double-sided adhesive film according to an embodiment of the present invention is the first release film, the second release film, and the antistatic property provided between the first release film and the second release film. It includes an adhesive layer.

In an embodiment of the present invention, the antistatic adhesive layer is an acrylic pressure-sensitive adhesive having a carboxyl group; Epoxy curing agents and isocyanate curing agents; Silane coupling agents; And an antistatic agent.

In the embodiment of the present invention, the antistatic adhesive layer is 0.08 to 0.09 parts by weight of the epoxy-based curing agent of 5% solids, the isocyanate of 45% solids relative to 100 parts of the acrylic pressure-sensitive adhesive having a carboxyl group of 21% solids 0.16 to 0.18 parts by weight of the system curing agent, a solid content of 45 to 50% of the silane coupling agent may include 0.08 to 0.09 parts by weight of the antistatic agent of 99.9% of the solid content of 0.25 to 2.0 parts by weight.

In an embodiment of the present invention, the acrylic pressure-sensitive adhesive may have a weight average molecular weight of 1 million to 1.5 million, the glass transition temperature (Tg) is -50 to -10 ℃.

In an embodiment of the present invention, the adhesive force of the antistatic adhesive layer may be preferably 400 to 600 g / 25mm.

In an embodiment of the present invention, it may be preferable that the surface resistance of the antistatic adhesive layer is 9.0 × 10 ⁸ to 3.0 × 10 ¹¹ dl / m ² .

In an embodiment of the present invention, when the peel force between the antistatic adhesive layer and the first release film is P1, and the peel force between the antistatic adhesive layer and the second release film is P2, P2 / P1 It may be preferred that is 1.3 to 3.0.

In an embodiment of the present invention, it may be preferable that P1 is 1 to 3 g / 25mm and P2 is 2 to 8 g / 25mm.

In an embodiment of the present invention, the second release film may include a base film and a release layer formed on the base film, and the base film may have an orientation angle of 0 ° to 8 °.

In the case of using the inorganic double-sided adhesive film according to the present invention, it is possible to easily perform the lamination and fixing of the optical film when manufacturing the polarizing plate, it is possible to improve the productivity of the polarizing plate production.

Since the antistatic adhesive layer of the inorganic double-sided adhesive film of the present invention exhibits excellent antistatic performance, by applying this as an adhesive layer for laminating and fixing the optical film, reducing the antistatic agent coating process, occurs during release film release It can reduce the damage of the liquid crystal caused by the static electricity.

In addition, by adjusting the peeling force of the first release film lower than the peeling force of the second release film, the first release film can be easily peeled off without deformation of the adhesive layer when the first release film is removed. In addition, by using a base film having an orientation angle of 0 ° to 8 ° as the base film of the heavy release film, the accuracy during the polarizing plate foreign material inspection can be increased.

Furthermore, since the antistatic adhesive layer of the present invention exhibits a surface resistance value of 3.0 × 10 ¹¹ dl / m ² or less, it is possible to prevent the liquid crystal from being damaged during the removal of the first and second release films and the lamination process of the optical film. Can be.

In addition, the antistatic adhesive layer according to the present invention may exhibit good reworkability and reliability while exhibiting excellent antistatic performance.

Hereinafter, the inorganic double-sided adhesive film according to the embodiment of the present invention will be described in more detail.

1 is a cross-sectional view showing an inorganic double-sided adhesive film according to an embodiment of the present invention.

Referring to Figure 1, the inorganic double-sided adhesive film according to an embodiment of the present invention is a light peeling release film 10, a heavy peeling release film 20, and the light peeling release film 10 and a heavy peeling release film. The antistatic adhesion layer 30 (henceforth an "adhesive layer") provided between 20 is included. In this embodiment, the first release film is referred to as the light release release film, and the second release film is referred to as heavy release film. The release film is classified into a light peeling release film and a heavy peeling release film according to the size of the peeling force, and the peeling force of the heavy peeling release film is greater than that of the light peeling release film.

Conventional double-sided adhesive film includes a base material for supporting the adhesive layer, while the upper and lower surfaces of the substrate, that is, including a configuration in which the adhesive layer is formed on each side, the inorganic double-sided adhesive film of the present invention is a conventional double-sided adhesive As the substrate supporting the adhesive layer is removed from the film, the adhesive layer is composed of one layer without the substrate, and both sides of the adhesive layer are used to adhere the skin adhesive, respectively.

Each of the light release release film 10 and the heavy release film 20 includes base films 11 and 21 and release layers 12 and 22 formed on the base films 11 and 21. The light peeling release film 10 and the heavy peeling release film 20 are provided on the upper and lower surfaces of the adhesive layer 30, respectively. In applying the inorganic double-sided adhesive film for laminating an optical film, by removing the light peeling release film 10 first, one surface of the adhesive layer 30 from which the light peeling release film 10 is removed After attaching to the optical film, the heavy release film 20 is removed.

The base films 11 and 21 are made of a material having heat resistance, and a film made of a heat resistant resin having a thickness in the range of 25 to 50 μm is used. As such a heat resistant resin, it is preferable to use polyester resins, such as polyethylene terephthalate (PET), polyethylene naphthalate, and polybutylene terephthalate, for example. can do. In particular, it may be preferable to use a PET film having a thickness of 38 ㎛ as the base film (11, 21).

When the PET film is used, the strength is 22.0 ± 8 kgf / mm ² in the MD direction, 30.0 ± 9 kgf / mm ^{2 in the} TD direction, and 150 ± 80% elongation in the MD direction and 100 ± 80% in the TD direction. Can be used.

On the other hand, it may be preferable to use a film having an orientation angle of 0 ° to 8 ° as the base film of the second release film. This is because, after laminating to the polarizing plate, the precision of the foreign material inspection of the polarizing plate is increased. The orientation angle is an angle at which the base film is stretched during the production of the base film, and indicates the inclination of the alignment main axis. The smaller the angle of the orientation angle, the more foreign matter in the polarizing plate is visible when the double-sided adhesive film is attached to the polarizing plate. Therefore, the precision at the time of foreign material inspection can be improved.

In an embodiment of the present invention, the initial peeling force between the adhesive layer 30 and the light release film 10 is P1, the peeling force between the adhesive layer 30 and the heavy release film 20 is In the case of P2, it may be preferable that P2 / P1 is 1.3 to 3.0. This is the light peeling release film 10 is first peeled off in the process of laminating the adhesive layer of the double-sided adhesive film on the optical film at this time, the adhesive layer 30 is completely attached to the heavy release film 20, the adhesive layer This is because deformation of (30) should not occur at all.

In an embodiment of the present invention, it may be preferable that P1 is 1 to 3 g / 25mm and P2 is 2 to 8 g / 25mm. When the P1 of the light release film 10 is less than 1g / 25mm, the adhesive layer 30 may be protected by a defect such as lifting or tunneling between the adhesive layer 30 and the light release film 10. If the P1 is greater than 3g / 25mm, the pressure-sensitive adhesive layer 30 may be separated from the heavy release film 20 when the light release film 10 is peeled off.

Peeling force (P2) of the heavy release film 20 is preferably not exceeding 10g / 25mm even after leaving the heavy release film for 24 hours at 70 ℃. The reason is that when the lamination material, for example, a polarizing film, a glass plate, a backlight unit, or the like is bonded to the adhesive layer according to the present invention for laminating the polarizing plate panel, the heavy release film 20 is automatically removed. This is because it must be easily removed.

In addition, if the difference between the peeling force of the light peeling release film and the heavy release film is large, the damage of the adhesive layer does not occur when removing the light peeling release film, but not easily removed when removing the heavy release film, Since there is a problem of damaging the surface, it is preferable to adjust P1 and P2 in a range where P2 / P1 becomes 1.3 to 3.0 if possible.

The release agent used in the light peeling and heavy peeling release film production is not particularly limited, but a silicone-based release agent having excellent peeling characteristics may be used. In particular, in consideration of the heat resistance of the base film, it is preferable to use an addition-reaction type silicone release agent. When apply | coating and hardening the said addition reaction type | mold silicone type release agent, it is preferable to dry and harden at the temperature of 115 degrees C or less. This is because when working on a base film having a width of 1300 mm or more at a temperature exceeding 115 ° C., lateral wrinkles and longitudinal wrinkles may occur due to heat shrinkage of the base film.

Formation of the release layer of the light release film and the heavy release film is applied to the base film by a variety of methods such as gravure coating, air knife coating, and then dried, cured by a method such as heat treatment, ultraviolet irradiation, etc. It can achieve by making it.

In the present invention, the adhesive layer 30 includes an adhesive, a curing agent, and an antistatic agent.

As the pressure-sensitive adhesive, all pressure-sensitive adhesives commonly used in this field may be used, and among those, an acrylic pressure-sensitive adhesive may be used in which a carboxyl group or a hydroxyl group is used alone as a functional group, or a carboxyl group and a hydroxyl group are used in combination. Preferably, the acrylic adhesive which has a carboxyl group as a functional group can be used.

In the present invention, the acrylic pressure-sensitive adhesive having a carboxyl group may be used in a weight average molecular weight of 1 million to 1.5 million and a glass transition temperature (Tg) of -50 to -10 ℃. Moreover, the acrylic adhesive which has a carboxyl group whose solid content is 21% can be used.

In the present invention, the curing agent may be used by mixing an epoxy curing agent and an isocyanate curing agent. As the epoxy curing agent, for example, polyglycidyl ether of polyoxyalkylene polyol, tetraglycidyl xylene diamine and the like can be used. As the isocyanate-based curing agent, for example, triylene diisocyanate, xylene isocyanate and the like can be used.

The epoxy curing agent may be used in an amount of 0.1 to 2 parts by weight, and more preferably 0.08 to 0.09 parts by weight, based on 100 parts by weight of the acrylic pressure sensitive adhesive having a carboxyl group having a solid content of 21%. The isocyanate curing agent may be used in an amount of 0.1 to 0.3 parts by weight, and more preferably 0.16 to 0.18 parts by weight, based on 100 parts by weight of the acrylic pressure sensitive adhesive having a carboxyl group having a solid content of 21%. In addition, the epoxy-based curing agent may be used with a solid content of 5%, and the isocyanate-based curing agent may be used with a solid content of 45%.

As the antistatic agent, a known antistatic agent may be used, for example, an ionic complex polymer antistatic agent may be used. The ion complex polymer antistatic agent is known from the Republic of Korea Patent Publication No. 2006-0066401, 2004-0064523, in particular LiPF ₆ , LiBF ₄ , LiSbF ₆ , LiClO ₄ , LiCF ₃ SO ₃ , LiAsF ₆ , LiC Cations mixed with one or more selected from (CF ₃ SO ₃ ) ₃ , LiN (CF ₃ SO ₃ ) ₂ , LiI, LiBr, LiCl, LiF, NaPF ₆ , NaClO ₄ , NaI, NaSCN, KSCN, KPF _6, or KClO ₄ An anion conductive organic compound such as trilauryl phosphite, trischloromethyl ester or dimethyl sulfoxide is added to the reaction product obtained by heating the metal salt with a cationic conductive organic compound such as propylene carbonate, ethylene glycol or dimethyl formamide while stirring. Ion complex polymer antistatic agent prepared by removing unreacted metal salt from the final reaction product obtained by heating with stirring can be used.

In the case of using LiNH ₂ or LiN (C ₂ H ₅ ) ₂ as the cationic metal salt, surface resistance and peeling antistatic performance even after elapse of time due to better chain bonding with the polymer as compared to the case of using other cationic metal salts described above. This is preferable because it is excellent and no surface transition occurs.

As antistatic agents, cationic surfactants (ammonium salt, sulfonium, phosphonium, etc.), anionic surfactants, polyoxyethylene alkylamines, polyhydric alcohol derivatives, nonionic surfactants, alkalamine derivatives, alkyl phosphate amines Salts, fatty acid esters, alkyldietanolamines, amphoteric surfactants, polystyrene glycol esters and the like can be used.

The antistatic agent may be used in an amount of 0.25 to 2.0 parts by weight, and preferably 0.34 parts by weight, based on 100 parts by weight of the acrylic pressure sensitive adhesive having a carboxyl group of 21% solids. When the antistatic agent is used at less than 0.25 part by weight based on 100 parts by weight of the acrylic adhesive having a carboxyl group having a solid content of 21%, the surface resistance of the adhesive layer may not have a value of 3.0 × 10 ¹¹ dl / m ² or less. In the case of using more than 2.0 parts by weight, a phenomenon in which the adhesive layer is transferred to the glass substrate when the adhesive force of the double-sided adhesive film is measured appears, and the bonding force between the optical film and the adhesive layer laminated with the optical film is weak and raised, and warped. In addition, light leakage occurs to reduce reliability.

In addition, the antistatic agent may be used with a solid content of 99.9%.

The composition constituting the adhesive layer may further include a silane coupling agent. As the silane coupling agent, a silane coupling agent containing an epoxy group may be used. The silane coupling agent may be used in an amount of 0.01 to 1 parts by weight based on 100 parts by weight of the acrylic adhesive having a carboxyl group having a solid content of 21%, more preferably 0.08 to 0.09. It can be used in parts by weight. In addition, as the silane coupling agent, a solid content of 45 to 50% may be used.

When the silane coupling agent adheres the adhesive layer to a substrate such as a glass substrate, the silane coupling agent improves the adhesion stability, and particularly, when the silane coupling agent is left for a long time under high temperature and high humidity.

In the present invention, the adhesive layer may be preferable to exhibit an adhesive force of 400 to 600 g / 25mm in order to improve the reworkability, the reliability by preventing the lifting and light leakage. When the adhesive force of the adhesive layer is less than 400 g / 25mm, light leakage due to lifting and bending occurs, and when the adhesive layer exceeds 600 g / 25mm, when the adhesive layer is removed from the optical film, the optical film is damaged and cannot be reused. Reworkability is poor.

In addition, it is preferable that the adhesive layer has a surface resistance value of 9.0 × 10 ⁸ to 3.0 × 10 ¹¹ dl / m ² , since it can prevent damage to the liquid crystal due to static electricity generated in the removal of the release film, the polarizing plate lamination process, and the like.

Taking the composition of the pressure-sensitive adhesive layer that satisfies the above-described adhesion and surface resistance values, the pressure-sensitive adhesive layer has a solid content of 5 parts based on 100 parts of the acrylic pressure-sensitive adhesive having a carboxyl group having a weight average molecular weight of 1 million to 1.5 million and a solid content of 21%. 0.08 to 0.09 parts by weight of% epoxy based curing agent, 0.16 to 0.18 parts by weight of isocyanate based hardener of 45% solids, 0.08 to 0.09 parts by weight of silane coupling agent of 45 to 50% solids, and antistatic agent of 99.9% of solids 0.25 To 2.0 parts by weight.

The pressure-sensitive adhesive layer is added to the acrylic pressure-sensitive adhesive having a carboxyl group and the isocyanate-based curing agent in the corresponding composition and stirred for 10 hours, and then put a silane coupling agent and an antistatic agent in the corresponding composition and stirred to form a mixed pressure liquid, The mixed solution can be formed by coating on the release layer 22 of the heavy release film 20.

As a method of coating the composition constituting the adhesive layer may be used a coating method such as comma knife coating, slot die coating, gravure, micro gravure, reverse, kiss roll. The dry coating amount during coating is preferably 10 to 30 g / m 2, and the thickness of the adhesive layer is preferably 15 to 25 μm.

After the adhesive layer is coated on the heavy release film, it is laminated with the light release film and rolled up in a roll to undergo a aging process. By providing the finished inorganic double-sided adhesive film to the polarizing plate manufacturers, the polarizing plate manufacturers can easily laminate and fix the polarizing film or retardation film using the double-sided adhesive film.

The double-sided adhesive film according to the present invention exhibits excellent adhesive properties with rework, reliability and blister resistance, while reducing the generation of static electricity generated during peeling of the release film or laminating the optical film, thereby preventing damage to the liquid crystal. have.

In addition, the antistatic agent is introduced into the adhesive layer, so that the adhesive layer having excellent charge performance can be provided by one coating, which is excellent in terms of economy.

Coating equipment according to an embodiment of the present invention, by coating the coating head portion and the cleanliness in the drying chamber in a 100 to 1,000 class level equipment using the environment of the coating equipment as a dust-free room Block dust and foreign substances (impurity) in the film, and work on less than two foreign substances of 100㎛ or more per M ² . Accordingly, it is possible to prevent the double-sided adhesive film irregularities due to the mixing of foreign matter.

In addition, the coater head of the pressure-sensitive adhesive coater is coated using a comma coater while maintaining the viscosity of the coating solution at 2,000 to 6,000 cps / 25 ° C., so that the coating thickness is less than ± 1.5 μm of the target thickness in a dry state.

The coater head of the release agent coater is coated using a microgravure coater, and the amount of the release agent applied is 0.17 to 0.23 g / m 2 for the light peelable release film and 0.14 to 0.20 g / m 2 for the heavy release film.

Hereinafter, the present invention will be described in more detail by explaining examples and experimental examples of the present invention.

However, the present invention is not limited to the following examples, and various forms of embodiments can be implemented within the scope of the appended claims, and the following examples are only ordinary in the art while making the disclosure of the present invention complete. It is intended to facilitate the implementation of the invention to those with knowledge.

[Examples and Comparative Examples]

1. Preparation of adhesive layer composition

Comparative Example 1

To 100 parts by weight of an acrylic pressure-sensitive adhesive containing a carboxyl group having a weight average molecular weight of 1.2 million and a solid content of 21%, 0.233 parts by weight of an isocyanate curing agent having a solid content of 45% and 0.164 parts by weight of an epoxy curing agent having a solid content of 5% were stirred for 10 minutes. 0.2 weight part of antistatic agent of 99.9% of solid content, and 0.083 weight part of silane coupling agent of 48% of solid content were put, and it stirred, and prepared the uniform mixture liquid.

Comparative Example 2

To 100 parts by weight of an acrylic pressure-sensitive adhesive containing a carboxyl group having a weight average molecular weight of 1.2 million and 21% solids, 0.178 parts by weight of 45% isocyanate-based curing agent and 0.082 parts by weight of an epoxy-based curing agent of 5% solids were stirred for 10 minutes, 0.205 parts by weight of an antistatic agent having a solid content of 99.9% and 0.083 parts by weight of a silane coupling agent having a solid content of 48% were added and stirred to prepare a uniform mixed solution.

Example

To 100 parts by weight of an acrylic pressure-sensitive adhesive containing a carboxyl group having a weight average molecular weight of 1.2 million and 21% solids, 0.178 parts by weight of 45% isocyanate-based curing agent and 0.082 parts by weight of an epoxy-based curing agent of 5% solids were stirred for 10 minutes, 0.34 parts by weight of an antistatic agent having a solid content of 99.9% and 0.083 parts by weight of a silane coupling agent having a solid content of 48% were added and stirred to prepare a uniform mixed solution.

Comparative example

To 100 parts by weight of an acrylic pressure-sensitive adhesive containing a carboxyl group having a weight average molecular weight of 1.2 million and 21% solids, 0.04 parts by weight of an isocyanate curing agent having a solid content of 45% was stirred for 10 minutes, and then 0.15 parts by weight of an antistatic agent having a solid content of 99.9% and a solid content. 0.06 parts by weight of 48% of a silane coupling agent was added thereto, and stirred to prepare a uniform mixed solution.

2. Production of double-sided adhesive film

On one surface of a polyethylene terephthalate film having a thickness of 38 μm, an addition reaction type silicone-based release agent was applied so as to have an application amount of 0.15 to 0.25 g / m 2, and then dried in a hot air circulation oven at 110 ° C. for 60 seconds and aged at 40 ° C. for 48 hours. The light peeling release film 10 was prepared.

In addition, 20 parts by weight of a release additive was added to one side of a polyethylene terephthalate having a thickness of 38 μm and an orientation angle of 6 ° to 100 parts by weight of an addition-reaction type silicone release agent, and applied so that the coating amount was 0.15 to 0.25 g / m 2, Drying for 60 seconds in a hot air circulation oven of 110 ℃ and aged for 48 hours at 40 ℃ to prepare a peeling release film 20.

Thereafter, the mixed solution prepared above is coated on the release layer 22 of the heavy release film 20 so that the coating amount is 15 g / m 2, dried at 100 ° C. for 1 minute, and then lightly peeled on the adhesive layer 30. The release film 10 was laminated, and aged at room temperature 23-25 ° C. for 7 days to prepare a double-sided adhesive film.

In addition, in Comparative Example 3, a double-sided adhesive film having a coating amount of 25 g / m 2 was prepared using the mixed solution prepared in Comparative Example 2.

[Test Example 1: release peel force measurement]

An evaluation sample was prepared by cutting the double-sided adhesive film prepared above to a size of 25 mm × 150 mm. In the evaluation sample, the light peeling release film was peeled off at a peel rate of 300 mm / min and a peeling angle of 180 ° to measure the peel force of the light peeling release film.

After that, the evaluation sample from which the light peeling release film was removed was laminated on a PET film having a thickness of 25 μm, and the remaining heavy peeling release film was peeled off at a peeling speed of 300 mm / min and a peeling angle of 180 ° to reduce the initial peeling force of the peeling release film. Measured.

In addition, the peeling force of the heavy release film after aging for 24 hours at 70 ℃ was measured in the same manner as described above.

Test Example 2: Adhesion Measurement

The light peeling film is removed from the double-sided adhesive film prepared above, and the adhesive layer from which the light peeling film is removed is attached to a PET film having a thickness of 25 μm. Thereafter, the heavy peeling film was removed, and the pressure-sensitive adhesive layer from which the heavy peeling film was removed was reciprocated once with a roller of 2 kg and attached to a glass substrate to prepare an evaluation sample.

After adhesion, the mixture was left at room temperature for 30 minutes, and then the adhesive layer was peeled off from the glass substrate at a peeling rate of 300 m / min and a peeling angle of 180 ° to measure the adhesive force on the adhesive surface of the adhesive layer to which the heavy release film was attached. .

Test Example 3: Measurement of Surface Resistance and Evaluation of Antistatic Performance

The double-sided adhesive film prepared above was cut into a size of 100 mm in width and 100 mm in length , and the light peeling film was removed, and one surface of the adhesive layer was laminated by laminating onto a PET film or polarizing film having a thickness of 25 μm, and the heavy peeling film was evaluated. Samples were prepared. Using a surface resistance measuring instrument (MCT-HT450, Mitsubishi), the left, right, and middle areas of the sample were measured, respectively, and the average value was taken. At this time, measured at 100V for 30 seconds.

Then, the antistatic performance was evaluated based on the measured surface resistance values. The case where the measured surface resistance value was 3.0x10 <^11> Pa / m <^2> or less was represented by "(circle)", and the case exceeding 3.0x10 <^11> Pa / m < ² > was shown as "x".

[Test Example 4: Evaluation of reworkability]

Remove the light peeling film from the double-sided adhesive film prepared above to adhere one side of the adhesive layer to the polarizing film, remove the heavy peeling film to attach a glass substrate on the other side of the pressure-sensitive adhesive layer removed the evaluation sample Was prepared. After auto-clave treatment (aging) for 2 hours at a temperature of 60 ℃, and left for 1 hour at 23 ℃ was observed for damage of the polarizing film during peeling. The evaluation criteria for reworkability are as follows.

<Evaluation Criteria>

No damage of polarizing film: ○

Slight damage of the polarizing film: △

Large amount of damage of the polarizing film: ×

[Test Example 5: Reliability Evaluation]

The evaluation sample prepared in Test Example 4 was autoclaved for 20 minutes at a temperature of 5 atmospheres and 50 ° C, and then 1000 hours at a temperature of 80 ° C, 1000 hours at a temperature of 60 ° C and a relative humidity of 90%. After 1000 hours at the temperature of -40 ℃, it was observed whether the lifting or bending occurred.

In addition, by measuring the difference in contrast after leaving the light leakage was measured.

The evaluation criteria for reliability are as follows.

<Evaluation Criteria>

No lifting or occurrence: ○

Slight lifting or bending: △

Large amount of lifting or bending: ×

No light leakage: ○

Slight light leakage occurs: △

Large amount of light leakage: ×

Table 1 shows the composition of the adhesive layers prepared in Examples and Comparative Examples and the test results of the test examples.

TABLE 1

From the results in Table 1, it can be seen that in the case of the embodiment including an antistatic agent in an amount of 0.25 parts by weight or more, the adhesive strength and the antistatic performance are excellent. In Comparative Examples 1 to 3 and Comparative Example containing less than 0.25 part by weight of the antistatic agent, the surface resistance is much higher than the surface resistance of the Example, it can be seen that the antistatic performance is poor.

In the case of Comparative Example 1, the reworkability is low, and in Comparative Example 3, the thickness of the adhesive layer is 25 μm, which is relatively thick, indicating that the reworkability is poor. In the case of the comparative example, it turns out that both reworkability and reliability are inferior.

1 is a cross-sectional view showing an inorganic double-sided adhesive film according to an embodiment of the present invention.

* Description of the symbols for the main parts of the drawings *

10: first release film 20: second release film

30: adhesion layer

Claims (12)

Inorganic double-sided adhesive film having antistatic performance, First release film; Second release film; And It includes an antistatic adhesive layer provided between the first release film and the second release film, The antistatic adhesive layer, Acrylic adhesive which has a carboxyl group; Epoxy curing agents and isocyanate curing agents; Silane coupling agents; And Contains an antistatic agent, Peeling force of the first release film is lower than the peeling force of the second release film, The second release film includes a base film and a release layer formed on the base film, the base film is an inorganic material double-sided adhesive film, characterized in that the orientation angle is 0 ° to 8 °. The method of claim 1, wherein the antistatic adhesive layer, 0.08 to 0.09 parts by weight of an epoxy-based curing agent having a solid content of 5%, 0.16 to 0.18 parts by weight of an isocyanate-based curing agent having a solid content of 45%, and a silane coupling agent having a solid content of 45 to 50% based on 100 parts of an acrylic pressure-sensitive adhesive having a carboxyl group having a solid content of 21%. Inorganic double-sided adhesive film, characterized in that it comprises 0.08 to 0.09 parts by weight and an antistatic agent of 99.9% solids content of 0.25 to 2.0 parts by weight. The inorganic double-sided adhesive film of claim 1 or 2, wherein the acrylic pressure-sensitive adhesive has a weight average molecular weight of 1 million to 1.5 million, and a glass transition temperature (Tg) of -50 to -10 ° C. The inorganic double-sided adhesive film according to claim 1 or 2, wherein the adhesive force of the antistatic adhesive layer is 400 to 600 g / 25 mm. The inorganic double-sided adhesive film according to claim 1 or 2, wherein the surface resistance of the antistatic adhesive layer is 9.0 × 10 ⁸ to 3.0 × 10 ¹¹ dl / m ² . The inorganic double-sided adhesive film according to claim 1 or 2, wherein the antistatic adhesive layer has a thickness of 15 to 25 μm. The method according to claim 1 or 2, The antistatic agents include cationic surfactants, anionic surfactants, polyoxyethylene alkylamines, polyhydric alcohol derivatives, nonionic surfactants, alkalamine derivatives, alkyl phosphate amine salts, fatty acid esters, alkyl diethanol amines, both Inorganic double-sided adhesive film, characterized in that it is a surfactant or a polystyrene glycol ester. The method according to claim 1 or 2, When the peel force between the antistatic adhesive layer and the first release film is P1, and the peel force between the antistatic adhesive layer and the second release film is P2, P2 / P1 is 1.3 to 3.0. Inorganic double sided adhesive film. The method according to claim 1 or 2, Peel force between the antistatic adhesive layer and the first release film is 1 to 3 g / 25mm, Peel force between the antistatic adhesive property and the second release film is an inorganic material double-sided adhesive film, characterized in that 2 to 8 g / 25mm. delete The method according to claim 1 or 2, The base film is an inorganic double-sided adhesive film, characterized in that made of polyethylene terephthalate (PET), polyethylene naphthalate, or polybutylene terephthalate. The method according to claim 1 or 2, The base film is an inorganic double-sided adhesive film, characterized in that having a thickness in the range of 25 ~ 50㎛.

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