KR20090131460A - Antistatic surface protection film - Google Patents

Abstract

PURPOSE: An antistatic surface protection film is provided to prevent surface damage of components and display products in carrying/keeping, and to be attached/removed from the display products easily without scratches. CONSTITUTION: An antistatic surface protection film includes the followings: a core layer(1) contacting a polystyrene-based polymer; a skin layer(2) containing the polyethylene-based polymer and an antistatic agent, and laminated on either side of the core layer; and a tie layer(3) uniting the core layer and the skin layer between the core layer and the skin layer. The tie layer includes the polymer including repeating unit having the polystyrene-based polymer and compatibility.

Description

Antistatic Surface Protection Film {ANTISTATIC SURFACE PROTECTION FILM}

The present invention relates to an antistatic surface protection film capable of protecting the surface of a display product and its parts from static electricity generated when the display product and its parts are transported and / or stored.

In general, display products such as LCDs and their components are subjected to numerous transportation and storage processes from the factory until they are delivered to the consumer. When transporting or storing, display products and parts thereof are transported and / or stored with the surface protected using a surface protection film to prevent the surface from being damaged.

The surface protective film is made of a film such as a polypropylene film, vinyl chloride film, polyethylene terephthalate film and the like. Such surface protective films are applied to the surface of display products and their components by various methods. For example, a method of adhering a surface protective film having a pressure-sensitive adhesive layer on one surface to a surface of a display product and a part thereof; The method of fixing a film to this is mentioned.

The display product and parts thereof having the surface protection film adhered or fixed to the surface in this way should remove the surface protection film on the surface from the surface of the display product and the parts thereof in use. At this time, static electricity may be generated between the surface of the display product and its components and the film. The generated static electricity may attract impurities or dust to adhere to the display product and its components, and the display product and its components may be damaged by electrostatic discharge (ESD).

Therefore, in order to prevent static electricity generation, an adhesive layer or an adhesive tape containing an antistatic agent such as an inherently conductive polymer (ICP) or a surfactant is used on the surface of the surface protection film. However, in order to suppress the generation of static electricity, a large amount of antistatic agent had to be added to the pressure-sensitive adhesive layer or the adhesive tape, which lowered the adhesive force of the pressure-sensitive adhesive layer or the adhesive tape. Thus, during storage or transportation of the display product and its parts, the pressure-sensitive adhesive layer is easily separated from the surface protection film or the adhesive tape is separated from the surface protection film and the display product and the parts thereof. As a result, the surface protection film may be separated from the display product and its parts, thereby damaging the surface of the display product and its parts.

In addition, since most of the surface protective film is too flexible, workability may be reduced when the surface of the display product and its components is coated with the surface protective film. Nevertheless, the use of a surface protection film that is too stiff may result in scratching of the film on the surface of the display product and its components upon removal of the surface protection film from the surface of the display product and its components.

The inventors of the present invention not only prevent the surface damage of the display product and its parts during transport / storage, but also easily attach to the display product and the parts thereof without causing scratches on the surface of the display product and the parts thereof. Efforts have been made to produce surface protective films that can be removed / removed.

As a result, the present inventors laminated a skin layer containing a polyethylene-based polymer and an antistatic agent on both sides of a core layer made of a polystyrene-based polymer by a tie layer made of a polymer compatible with both the polystyrene-based polymer and the polyethylene-based polymer. It has been found that an antistatic surface protective film having a smooth surface and improved adhesion / adhesion workability of the film can be produced. The present invention is based on this.

The present invention, a core layer containing a polystyrene-based polymer (core layer); A skin layer laminated on both sides of the core layer and containing a polyethylene-based polymer and an antistatic agent; And a tie layer coupling the core layer and the skin layer between the core layer and the skin layer, wherein each tie layer is compatible with a polystyrene-based polymer. There is provided an antistatic surface protection film characterized in that it comprises a repeating unit and a polymer comprising a repeating unit compatible with the polyethylene-based polymer.

In addition, the present invention comprises the steps of: iii) preparing a polymer material for core layer formation with a polystyrene-based polymer; Ii) preparing a polymer material for forming a skin layer by mixing a polyethylene-based polymer and an antistatic agent; Iii) preparing a tie layer-forming polymer material from a polymer including a moiety compatible with the polystyrene-based polymer and a moiety compatible with the polystyrene-based polymer; And iii) co-extruding the core layer forming polymer material, the skin layer forming polymer material and the tie layer forming polymer material.

An antistatic surface protection film according to the present invention is a polymer comprising a repeating unit compatible with a polystyrene-based polymer and a repeating unit compatible with a polyethylene-based polymer on both surfaces of a core layer made of a polystyrene-based polymer. By laminating a polyethylene-based polymer and an antistatic agent skin layer by using a tie layer, the surface of the display product and its parts is not only prevented from being damaged during transportation / storage, but also scratched by the film on the surface of the display product and its parts. It can be easily attached / removed to the display product and its parts without generating scratches.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

The antistatic surface protection film according to the present invention includes a core layer (1) made of polystyrene-based polymer and a skin layer (2) made of polyethylene-based polymer and antistatic agent, which are compatible with the polystyrene-based polymer. It can be said that the structure is bonded by a tie layer 3 made of a polymer comprising a repeating unit and a repeating unit compatible with the polyethylene-based polymer (see FIG. 1). Such an antistatic surface protection film of the present invention not only has low surface resistance, but also has a smooth surface and moderate stiffness. Therefore, the antistatic surface protection film of the present invention can be easily adhered to the surface of the display product and its parts without the occurrence of scratches on the surface of the display product and the parts thereof, and also detached (removed) from the display product and the parts thereof. Can be. In addition, the antistatic surface protection film of the present invention can protect the surface of the display product and its components from static electricity or external physical impact.

According to one example of the invention, the core layer 1 comprises a polystyrene-based polymer. The polystyrene-based polymer has a phenyl group attached to a hydrocarbon main chain, and can be obtained by radical vinyl polymerization of a styrene monomer. Examples of the styrene monomers include styrene, α-methylstyrene, p-methylstyrene, and the like. By such a core layer present in the antistatic surface protection film of the present invention, the operator can easily adhere the surface protection film to the display product and its parts even if the surface protection film is a sheet, and from the display product and its parts It can be easily removed (removed).

However, the polystyrene-based polymer is brittle, so that the core layer is slightly lacking in flexibility. In order to increase the flexibility of the core layer, the present invention may further include a styrene-butadiene copolymer in addition to the polystyrene-based polymer. Thereby, the core layer becomes slightly flexible (ie, slightly stiff), whereby the adhesion / desorption (removal) workability of the film can be improved.

According to an example of the present invention, the styrene-butadiene copolymer is suitably included in an amount of about 10 to 100 parts by weight based on 100 parts by weight of the polystyrene-based polymer. If the content of the styrene-butadiene copolymer is less than 10 parts by weight, the film may be broken when the film is wound in a roll form, and if the content of the styrene-butadiene copolymer is more than 100 parts by weight, the stiffness of the film It is weak and the working efficiency can be reduced.

The core layer formed of the polystyrene-based polymer can be said to be the support layer of the antistatic surface protection film according to the present invention, and the thickness thereof is preferably about 50 to 80% of the total thickness of the surface protection film. According to an example of the present invention, when the total thickness of the film is about 70 to 120 μm, the thickness of the core layer may be about 40 to 90 μm.

On both sides of the core layer, a skin layer 2 containing a polyethylene-based polymer and an antistatic agent is laminated. The skin layer serves to impart antistatic property to the antistatic surface protection film of the present invention. The thickness of the skin layer is not particularly limited, but according to an example of the present invention, it may be about 10 to 20 μm.

Examples of the polyethylene-based polymer forming the skin layer include a high density polyethylene (HDPE) polymer, a low density polyethylene (LDPE) polymer, a linear low density polyethylene (LLDPE) polymer, an ethylene vinyl acetate (EVA) polymer and a mixture of two or more kinds of the polymers. have. Since the surface of the skin layer formed of such a polyethylene-based polymer is soft, scratches do not occur on the surface of the display product and its components by the surface protection film.

The skin layer of such polyethylene-based polymer includes an antistatic agent for imparting antistatic properties. The kind of the antistatic agent is not particularly limited, and any antistatic agent known in the art may be used without limitation. According to an example of the present invention, a material such as a surfactant or an ionomer may be used as the antistatic agent.

The surfactant is classified into anionic, cationic, zwitterionic and nonionic surfactants. Examples of cationic surfactants include quaternary ammonium compounds, and examples of anionic surfactants include alkylsulfonate, alkylsulfate, alkylphosphite and sodium alkyl. Sulfonates (sodium alkylsulfonate), and non-ionic surfactants include ethoxylated alkylamines, fatty acid esters, glyceride alkyamines, and polyethylene glycol esters. polyethylene glycol esters, and the like. Examples of the amphoteric ionic surfactants include alkylbetain and alkylalanine.

Further, an ionomer may be used without particular limitation in the present invention, as long as it is a polymer containing ions of metals belonging to Groups 1 to 16 of the periodic table. Specific examples of the metal ions include Na ⁺ , K ⁺ , Li ⁺ , Zn ^{2 +} .

Examples of such ionomers include ethylene-based ionomers, styrene-based ionomers, rubber-based ionomers, fluorine-based ionomers, sulfonated EPDM-based ionomers, carboxylated nitrile-based ionomers, and mixtures thereof. More specifically, poly (ethylene-co-methacrylic acid) ionomer, poly (butadiene-co-acrylic acid) ionomer [poly (butadiene-co-acrylic acid) ionomer ], Perfluorosulfonate ionomer, perfluorocarboxylate ionomer, telechelic polybutadidne ionomer, sulfonated ethylene-propylene terpolymer ionomer -propylene terpolymer ionomer], poly (styrene-co-acrylic acid) ionomer, sulfonated butyl elastomer ionomer, sulfonated polypenteneamer ionomer [ sulfonated polypentenamer ionomer], poly (styrene-co-butadiene-co-acrylic acid) ionomer], poly (butadiene-co-acrylonitrile-co- There are methacrylic acid) ionomer [poly (butadiene-co-acrylonitrile-co-acrylic acid) ionomer], and mixtures thereof and the like.

The amount of the antistatic agent may be about 10 to 50 parts by weight based on 100 parts by weight of the polyethylene-based polymer. If the amount of the antistatic agent is less than 10 parts by weight, the desired antistatic performance may not be exhibited. If the antistatic agent is more than 50 parts by weight, the amount of the antistatic agent may not only lower the properties of the polyethylene-based polymer but also increase the manufacturing cost. have.

Such a skin layer is difficult to be laminated on both sides of the core layer due to incompatibility between the polyethylene-based polymer of the skin layer and the polystyrene-based polymer of the core layer. Therefore, in order to laminate the skin layer on both sides of the core layer, a layer made of a material capable of bonding the both layers between the two layers is required. For example, when manufacturing the surface protection film of the present invention by coextrusion, a tie layer made of a polymer comprising a repeating unit compatible with a polystyrene-based polymer and a repeating unit compatible with a polystyrene-based polymer may be used. It is needed between the core layer and the skin layer.

Thus, at the interface between the tie layer and the core layer, a repeating unit portion compatible with the polystyrene-based polymer in the tie layer diffuses into the surface of the core layer or forms a covalent bond with the polystyrene-based polymer. Can be adhered to the layer. In addition, even at the interface between the tie layer and the skin layer, a repeating unit having compatibility with the polyethylene-based polymer in the tie layer diffuses into the surface of the skin layer or forms a covalent bond with the polyethylene-based polymer. Can be adhered to the layer. As a result, a skin layer may be adhered to both surfaces of the core layer by the tie layer. Therefore, the use of the surface protection film of the present invention does not cause the skin layer to be separated from the core layer.

Examples of the polymer including a repeating unit compatible with the polystyrene-based polymer and a repeating unit compatible with the polystyrene-based polymer include ethylene-alkyl (meth) acrylate copolymers. copolymer].

The thickness of the tie layer is not particularly limited, but according to an example of the present invention, the thickness of the tie layer may be about 3 to 7 μm.

On the other hand, the antistatic surface protection film of the present invention can be produced by a method for producing various laminated sheets known in the art, but it is appropriate to simultaneously form the core layer, skin layer and tie layer by the coextrusion method.

According to one embodiment of the present invention, the antistatic surface protection film according to the present invention comprises the steps of: i) preparing a polymer material for core layer formation from a polystyrene-based polymer; Ii) preparing a polymer material for forming a skin layer by mixing a polyethylene-based polymer and an antistatic agent; Iii) preparing a tie layer-forming polymer material from a polymer including a moiety compatible with the polystyrene-based polymer and a moiety compatible with the polystyrene-based polymer; And iii) co-extruding the polymer material for core layer formation, the polymer material for skin layer formation, and the polymer material for tie layer formation. At this time, the preparing step of the polymer material for forming the core layer, the preparing step of the polymer material for forming the skin layer, and the preparing step for the tie layer forming polymer material do not have a temporal relationship.

In the co-extrusion step, as shown in FIG. 2, through the annular die 401 at a temperature of about 200 ° C. in the first extruder 102 in which the core layer forming polymer material 101 is located at the center. Extruded. At the same time, the tie layer forming polymer material 301, 301 ′ is extruded through the annular die 401 at temperatures of about 160 ° C. in the third extruders 302, 302 ′, or optionally, a single extruder ( A single extruder can supply the tie layer forming material for both tie layers. In addition, the skin material for forming the layers 201, 201 'is also extruded through the annular die 401 at a temperature of about 200 ° C in the second extruders 202, 202', or optionally a single extruder (Iii) A skin layer forming material for the skin layer can be supplied. At this time, the one annular die 401 is connected to the first extruder 102, the second extruders 202, 202 ′ and the output opening of the third extruders 302, 302 ′. . Through such one annular die 401, each layer-forming polymer material is coextruded into concentrically stacked tubular films, wherein the coextruded tubular films are expanded by an air ring 402. This results in a multilaryered tubular bubble 501. Subsequently, the multilayer tubular bubble 501 is cut by a slitter (not shown), opened into a flat sheet, and then passed through a pair of nip rolls 403 to become a flat multilayer film 502. Thereafter, the flat multilayer film 502 is finally wound up by a winding roll (not shown).

The multilayer film 502 formed by such co-extrusion is a five-layer film in which a skin layer 2 is laminated on the core layer 1 by a tie layer on each side of the core layer 1. At this time, at the interface between the core layer 1 and the tie layer 3, the polystyrene-based polymer is covalently bonded to the repeating unit portion compatible with the polystyrene-based polymer. At the interface between the tie layer and the skin layer, the polyethylene-based polymer is covalently bonded to the repeating unit moiety compatible with the polyethylene-based polymer. As a result, the skin layer 2 may be attached to the core layer 1 by the tie layer 3. The antistatic surface protective film of the present invention formed in this manner does not cause the core layer and the skin layer to delaminate from each other when the film is used.

The core material for forming the core layer may be a polystyrene-based polymer in a pellet form, a polystyrene-based polymer in a granular form, or a polystyrene-based polymer in a powder form, or may be in the form of a polystyrene-based polymer syrup in a partially polymerized state. In addition, the polymer for forming the core layer may further include various types of styrene-butadiene copolymer to increase the flexibility of the core layer. If the polymer material for forming the core layer is in the state of polymer syrup, the viscosity may be about 1,000 to 100,000 cPs.

In addition, the polymer material for forming the skin layer may be in the form of a mixture of a polystyrene-based polymer and an antistatic agent in a pellet form, a mixture of a polystyrene-based polymer and an antistatic agent in a granular form, and a mixture of a polystyrene-based polymer and an antistatic agent in a powder form. And a mixture of a polystyrene-based polymer syrup and an antistatic agent in a partially polymerized state. If the polymer material for forming the skin layer is in a syrup state, the viscosity may be about 1,000 to 100,000 cPs.

In addition, the tie layer forming polymer material is a polymer comprising a repeating unit compatible with the repeating unit-polyethylene polymer compatible with the polystyrene-based polymer may be in the form of pellets, granules, powders, etc. It may be in the form of a polymer syrup in a polymerized state. If the tie layer forming polymer material is in a syrup state, the viscosity may be about 1,000 to 100,000 cPs.

In the coextrusion step, a moiety compatible with the polystyrene polymer and the polystyrene polymer, or a moiety compatible with the polyethylene polymer and the polyethylene polymer may form a covalent bond. For example, it is appropriate to adjust the coextrusion temperature. According to one embodiment of the invention, the coextrusion step is preferably carried out at a temperature of about 160 to 200 ℃.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the following examples are for illustrating the present invention, and the scope of the present invention is not limited thereto.

Example 1

As the polymer material for forming the core layer, about 100 parts by weight of a polystyrene polymer (G144 manufactured by Dongbu Hitec) in a pellet state was prepared.

As a polymer material for forming a skin layer, about 80 parts by weight of a low-density polyethylene polymer (Hanhwa Petrochemical 5302) in pellet form and a potassium-containing ionomer in pellet form as an antistatic agent (DuPont-MDP) ENTIRA SD- 100) About 20 parts by weight of the mixture was prepared.

Moreover, about 100 weight part of ethylene-acrylate copolymers (BYNEL 22E78 by a DuPont company) of a pellet state were prepared as a tie material for forming a polymer.

A core layer forming polymer material prepared in a centrally located first extruder, and a tie layer forming polymer material prepared in a total of two third extruders positioned on both sides of the first extruder, and a total of two positioned outside the third extruders. The polymer material for skin layer formation prepared in the 2nd large extruder was thrown in, respectively. Subsequently, in the first extruder, the second extruder, and the third extruder, each layer-forming polymer material is sequentially stacked in a concentric circle through a tube-shaped multilayer film (core layer, tie layer, and skin layer) through one annular die. ) Was coextruded. At this time, the extrusion temperature of the first extruder was about 200 ° C, the extrusion temperature of the second extruder was about 200 ° C, and the extrusion temperature of the third extruder was about 160 ° C. Thereafter, the coextruded tubular multilayer film is expanded by an air ring to form a multilayer tubular bubble, and the multilayer tubular bubble is cut open and then passed through a pair of nip rolls to protect a flat, 5-layer antistatic surface. A film was prepared. At this time, the thickness of the 5-layered film produced was about 100 μm, the thickness of the core layer was about 65 μm, the thickness of each skin layer was about 10.5 μm, and the thickness of each tie layer was about 7 μm.

Example 2

As a polymer material for forming a core layer, about 70 parts by weight of a polystyrene polymer in pellet form (G144 manufactured by Dongbu Hitec) and a styrene-butadiene copolymer in pellet form (K-RESIN KR-10 manufactured by Chevron) An antistatic surface protective film was prepared in the same manner as in Example 1 except that 30 parts by weight of the mixture was prepared.

Example 3

As a polymer material for forming a core layer, about 50 parts by weight of a polystyrene polymer in pellet form (G144 manufactured by Dongbu Hitec) and a styrene-butadiene copolymer in pellet form (K-RESIN KR-10, manufactured by Chevron) An antistatic surface protective film was prepared in the same manner as in Example 1 except that 50 parts by weight of the mixture was prepared.

Example 4

As a polymer material for skin layer formation, about 90 parts by weight of a low density polyethylene polymer (Hanhwa Petrochemical 5302) in a pellet state and a potassium-containing ionomer (MK-400 manufactured by Mitsui-Dipont) in an pellet as an antistatic agent An antistatic surface protective film was prepared in the same manner as in Example 1 except that 10 parts by weight of the mixture was prepared.

Example 5

As a polymer material for skin layer formation, about 85 parts by weight of a low density polyethylene polymer (Hanhwa Petrochemical 5302) in pellet form and a potassium-containing ionomer (MK-400 manufactured by Mitsui-Dipont) in pellet form as an antistatic agent An antistatic surface protective film was prepared in the same manner as in Example 1 except that 15 parts by weight of the mixture was prepared.

Example 6

As a polymer material for skin layer formation, about 80 parts by weight of a low density polyethylene polymer (Hanhwa Petrochemical 5302) in pellet form and a potassium-containing ionomer (MK-400 manufactured by Mitsui-Dipont) in pellet form as an antistatic agent An antistatic surface protective film was prepared in the same manner as in Example 1 except that 20 parts by weight of the mixture was prepared.

Comparative Example 1

A polystyrene antistatic film (manufactured by Mitsubishi Plastics, Inc.) having a thickness of about 100 μm was used.

Comparative Example 2

A polyester film (HH10 manufactured by SKC Co., Ltd.) having a thickness of 100 μm was used.

Comparative Example 3

Polyethylene-based antistatic film (manufactured by PMK Co., Ltd.) having a thickness of 100 μm was used.

Experimental Example 1

In order to examine the antistatic properties of the antistatic surface protective film according to the present invention, the surface resistance of the films prepared in Examples 1 to 6 and the films of Comparative Examples 1 and 2 was set to ASTM D 257-. It was measured according to 07. In particular, the surface resistance of the films prepared in Examples 4 to 6 was measured to determine the change in the antistatic properties according to the change in the content of the antistatic agent in the skin layer. At this time, the surface resistance was measured under a relative humidity of about 22 ° C. and 32%. The measurement results are shown in Tables 1 and 2, respectively.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Surface resistance (Ω / ㎡) 10 ⁸ 10 ⁸ 10 ⁸ 10 ¹⁰ 10 ⁹

As can be seen from Table 1, the films of Comparative Examples 1 and 2 had surface resistances of about 10 ¹⁰ Pa / m 2 and 10 ⁹ Pa / m 2, respectively. On the other hand, the surface resistance of the films prepared in Examples 1 to 3 were all about 10 ⁸ Ω / ㎡. Thus, it was confirmed that the antistatic surface protective film according to the present invention may have a slightly higher antistatic property than the conventional film.

Example 4 Example 5 Example 6 Surface resistance (Ω / ㎡) 3.10 × 0 ¹³ 7.54 × 10 ¹² 3.02 × 10 ¹⁰

As shown in Table 2, the surface resistance of the films prepared in Examples 4 to 6 was confirmed that the surface resistance is lower as the content of the antistatic agent increases. In particular, in order to ensure that the surface resistance is about 10 ¹² Ω / ㎡ or less it was confirmed that the content of the antistatic agent is about the content of the antistatic agent of the film prepared in Example 6.

Experimental Example 2

In order to confirm whether scratches are formed on the surface of the display product and its components by the antistatic surface protection film according to the present invention, the films prepared in Examples 1 to 3 and the films of Comparative Examples 1 and 2 Hardness of was measured according to ASTM D 3363-05. Here, the hardness is shown in the order of (Soft) 3B → 2B → B → HB → H → 2H → 3H → 4H (Hard). The measurement results are shown in Table 3.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Hardness 3B 3B 3B 2B 3H

As a result of the measurement, the antistatic surface protective film prepared in Examples 1 to 3 had a surface of 3B soft in comparison with the film of Comparative Example 2 having the hardest surface at 3H.

Thus, when the antistatic surface protection film of the present invention adheres to the display product and its parts, and the antistatic surface protection film of the present invention is detached (removed) from the display product and its parts, the antistatic property of the present invention It has been found that scratches on the surface of the display product and its components can be reduced by the surface protective film.

Experimental Example 3

In order to evaluate the ease of adhesion / desorption operation of the antistatic surface protection film according to the present invention, storage modulus and tensile strength were respectively measured as follows.

<Elastic modulus of storage>

The storage modulus of the films prepared in Examples 1 to 3 and the films of Comparative Examples 1 to 3 was determined by TA Instrument's DMA Q800 ™ under 20 μm amplitude at a temperature of 40 ° C. for 5 minutes. Measured using. The measurement results are shown in FIG. 3.

Tensile strength

Tensile strength of the films prepared in Examples 1 to 3 and the films of Comparative Examples 1 and 2 was measured according to ASTM D 882-02. The measurement results are shown in Table 4.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Tensile strength (kg / ㎡) MD 2.818 3.043 3.309 3.543 13.717 TD 2.145 2.688 2.324 8.133

1) As a result of measuring the storage elastic modulus, the film of Comparative Example 3 had a storage elastic modulus of about 120 MPa, which was too flexible, so that the workability was not appropriate. On the other hand, the film of Comparative Example 2 was too stiff with a storage modulus of about 4,300 MPa.

In comparison, the antistatic surface protective films prepared in Examples 1 to 3 had a storage modulus between the film of Comparative Example 2 and the film of Comparative Example 3. That is, the antistatic surface protective films prepared in Examples 1 to 3 were slightly pliable (ie, slightly stiff). In addition, as the content of the styrene-butadiene copolymer in the core layer of the antistatic surface protection film increases (Example 1 → Example 3), the storage modulus is lowered from about 2000 MPa to about 1600 MPa, thereby improving the flexibility of the film. It became.

2) As a result of measuring the tensile strength, in Comparative Example 1, the tensile strength in the direction of MD (Machine Direction) was about 3.543 kg / 43, and the tensile strength in the direction of CD (Cross Dircction) was about 3.543 kg /. In Comparative Example 2, the tensile strength in the MD direction was about 13.717 kg / cc, and the tensile strength in the CD direction was about 8.133 kg / dl.

In comparison, in the case of the antistatic surface protective film prepared in Example 1, the tensile strength in the MD direction was about 2.818 kg / cc, and the tensile strength in the CD direction was about 2.145 kg / cc. Further, as the content of the styrene-butadiene copolymer in the core layer of the antistatic surface protection film according to the present invention increases (Example 1 → Example 3), the tensile strength in the MD direction is about 2.818 to about 3.309 kg / ㎣. Increased to. However, as the content of the styrene-butadiene copolymer increased, the tensile strength in the CD direction increased from about 2.145 to about 2.688 kg / ㎣ and then decreased to 2.324 kg / ㎣.

3) Therefore, in the case of the antistatic surface protection film according to the present invention, the operator can easily adhere the sheet of film to the display product and its parts, compared to the conventional film, and the film itself is brittle or bent. It has been found that the film can be detached from the display product and its parts without deformation. That is, in the case of the antistatic surface protection film according to the present invention, it can be seen that the adhesion / desorption work efficiency of the film can be improved.

In addition, since the antistatic surface protective film itself according to the present invention does not brittle or bend when detaching the film, it was confirmed that the scratch did not occur on the surface of the display product and its parts by the film. In addition, as the content of the styrene-butadiene copolymer in the core layer was increased, it was confirmed that the deformation of the film can be prevented.

1 is a cross-sectional view of an antistatic surface protection film according to the present invention.

Figure 2 is a simplified view showing the manufacturing process of the antistatic surface protection film according to the present invention.

3 is a graph showing the storage modulus of the films of Examples 1 to 3 and Comparative Examples 1 to 3.

<Description of Major Codes in Drawings>

1: core layer, 2: skin layer, 3: tie layer,

101: polymer material for forming the core layer, 102: the first extruder,

201, 201 ': polymer material for skin layer formation,

202, 202 ': second extruder,

301, 301 ': polymer material for forming a tie layer,

302, 302 ': third extruder,

401: annular die, 402: air ring, 403: nip roll,

501: multilayer tubular bubble, 502: flat multilayer film

Claims (17)

A core layer containing a polystyrene-based polymer; A skin layer laminated on both sides of the core layer and containing a polyethylene-based polymer and an antistatic agent; And A tie layer coupling the core layer and the skin layer between the core layer and the skin layer As antistatic surface protection films comprising: Each tie layer is an antistatic surface protective film, characterized in that it comprises a polymer comprising a repeating unit compatible with the polystyrene-based polymer and a repeating unit compatible with the polyethylene-based polymer. The antistatic surface protection film according to claim 1, wherein the core layer, skin layer and tie layer are formed by coextrusion. The antistatic surface protection film according to claim 1, wherein the core layer further contains a styrene-butadiene copolymer. The antistatic surface protection film according to claim 3, wherein the styrene-butadiene copolymer is 10 to 100 parts by weight based on 100 parts by weight of the polystyrene-based polymer. The method of claim 1, wherein the polyethylene-based polymer is a high density polyethylene (HDPE) polymer, low density polyethylene (LDPE) polymer. An antistatic surface protective film, characterized in that selected from the group consisting of linear low density polyethylene (LLDPE) polymer, ethylene vinyl acetate (EVA) polymer and a mixture of two or more kinds of the polymer. The antistatic surface protective film according to claim 1, wherein the antistatic agent is a surfactant or an ionomer. The antistatic surface protective film according to claim 6, wherein the surfactant is selected from the group consisting of anionic surfactants, cationic surfactants, zwitterionic surfactants, and nonionic surfactants. The method of claim 7, wherein the cationic surfactant is a quaternary ammonium compound, the anionic surfactant is alkylsulfonate, alkylsulfate, alkylphosphite or Sodium alkylsulfonate (sodium alkylsulfonate), the amphoteric surfactant is alkyl betaine (alkylbetain) or alkylalanine (alkylalanine), the nonionic surfactant is ethoxylated alkylamine (ethoxylated alkylamine) Antistatic surface protective film, characterized in that, fatty acid ester (fatty acid ester), glyceride alkylamine (glyceride alkyamine), polyethylene glycol ester (polyethylene glycol ester). The antistatic surface protective film according to claim 6, wherein the ionomer contains one of ions of a metal belonging to Groups 1 to 16 of the periodic table. The antistatic surface protective film of claim 9, wherein the metal ions are selected from the group consisting of Na ⁺ , K ⁺ , Li ^+, and Zn ^{2 +} . The ionomer of claim 6, wherein the ionomer is selected from the group consisting of ethylene-based ionomers, styrene-based ionomers, rubber-based ionomers, fluorine-based ionomers, sulfonated EPDM-based ionomers, carboxylated nitrile-based ionomers and mixtures thereof. An antistatic surface protective film characterized by being selected. The method of claim 6, wherein the ionomer is a poly (ethylene-co-methacrylic acid) ionomer, a poly (butadiene-co-acrylic acid) ionomer [poly (butadiene-) co-acrylic acid ionomer], perfluorosulfonate ionomer, perfluorocarboxylate ionomer, telechelic polybutadiene ionomer, sulfonated ethylene-propylene Sulfonated ethylene-propylene terpolymer ionomer, poly (styrene-co-acrylic acid) ionomer, sulfonated butyl elastomer ionomer, sulfonated butyl elastomer ionomer Sulfonated polypentenamer ionomer, poly (styrene-co-butadiene-co-acrylic acid) ionomer, poly (butadiene-co- Acrylonitrile, methacrylic acid -co-) ionomer [poly (butadiene-co-acrylonitrile-co-acrylic acid) ionomer] and is characterized by a member selected from the group consisting of a mixture antistatic surface protecting film. The antistatic surface protective film according to claim 1, wherein the antistatic agent is included in an amount of 10 to 50 parts by weight based on 100 parts by weight of the polyethylene-based polymer resin. According to claim 1, wherein the polymer comprising a repeating unit compatible with the polystyrene-based polymer and the repeating unit compatible with the polyethylene-based polymer is an ethylene-alkyl (meth) acrylate copolymer [ethylene-alkyl (meth) acrylate copolymer] antistatic surface protective film characterized in that. Iii) preparing a polymer material for forming a core layer from a polystyrene-based polymer; Ii) preparing a polymer material for forming a skin layer by mixing a polyethylene-based polymer and an antistatic agent; Iii) preparing a tie layer-forming polymer material from a polymer including a moiety compatible with the polystyrene-based polymer and a moiety compatible with the polystyrene-based polymer; And Iii) co-extrusion of the core layer forming polymer material, skin layer forming polymer material and tie layer forming polymer material Method of producing an antistatic surface protection film comprising a. The method for producing an antistatic surface protection film according to claim 15, wherein the polymer material for forming a core layer further comprises a styrene-butadiene copolymer. The method of claim 15, wherein the coextrusion step is performed at a temperature of 160 to 200 ℃.

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