KR101058395B1 - Double sided hard coat film for display protection - Google Patents

Abstract

The present invention relates to a double-sided hard coating film for display protection.

The display protective double-sided hard coating film of the present invention is a plastic base film, the first hard coating layer formed on one surface of the plastic base film, the anti-blocking layer and the plastic substrate to meet the surface water contact angle 90 to 120 ° formed on the first hard coating layer A second hard coating layer formed on the back surface of the film, and the anti-friction coefficient between the anti-blocking layer and the second hard coating layer (μ) is less than 0.3, anti-blocking properties and antifouling properties are improved without deterioration of optical properties, In particular, since the surface hardness is excellent, it is useful to apply to the touch panel of the touch screen.

Plastic base film, hard coating, anti blocking, antifouling, scratch resistance

Description

DOUBLE SIDE HARD COATING FILM TO PROTECT DISPLAY}

The present invention relates to a double-sided hard coating film for display protection, and more particularly, a first hard coating layer and an anti-blocking layer having antifouling properties are sequentially laminated on one surface of the plastic base film, and scratch resistance on the back side of the plastic base film. The second hard coating layer to implement the laminated structure, and excellent anti-blocking properties and antifouling properties without deterioration of the optical properties, and relates to a double-sided hard coating film for display protection that can prevent scratches on the back of the film.

Conventional hard coating film is a surface protection and anti-glare of screen display devices such as liquid crystal display (LCD), plasma display panel (PDP), electroluminescent display (ELD), cathode ray tube display (CRT) and portable digital terminal (PDA) Although it has been used for the purpose of anti-reflection, it is recently applied to the touch panel of the touch screen with the increase of the touch screen market.

The touch screen is a touch display device in which a command is executed when a user touches a specific command portion of a display screen with a hand or a special device. The touch panel used is a resistive type, and the transparency of an ITO film or the like on one surface of a transparent plastic substrate is used. The transparent conductive thin films face each other so as to face each other through an insulating spacer between two substrates on which the conductive thin films are stacked.

In general, since the surface of the touch panel is exposed to the outside, there is a problem that the appearance of the display panel is poor due to scratching or stamping of the display surface due to the load and hardness of an object such as a pen. In order to give a function to make a user feel good writing, a hard coating film is widely used.

When the hard coating is applied to the plastic substrate as described above, if only the single-sided hard coating is applied, the surface on which the hard coating layer is not formed is vulnerable to external stimulus generated during the process, causing problems such as scratches on the surface of the plastic substrate film. The double-sided coating of the situation is required.

In addition, when the hard coating film is wound and stored in a roll state, it may cause blocking due to poor activity due to interlayer adhesion or chemical force, and when blocking occurs, it becomes difficult to separate between layers or to force separation. As large damage occurs to the substrate or the coating layer, antiblocking property is required between the substrate and the substrate to prevent the damage.

Accordingly, Japanese Patent Application Laid-Open No. 2004-151937 and Japanese Patent Application Laid-Open No. 2005-132897 disclose a technique for forming a backcoat containing particulate matter to prevent adhesion between layers, but the particles used in the backcoat are anti It is difficult to expect other functions besides providing blocking properties, and if the surface of the hard coating does not contain antifouling properties, there is a problem that is vulnerable to external contaminants.

Accordingly, the present inventors have endeavored to realize a double-sided hard coating film having excellent surface hardness and anti-blocking property between the hard coating films and at the same time improved antifouling properties, and thus have a first hard coating layer and antifouling properties on one surface of the plastic base film. The anti-blocking layer is sequentially formed, and the second hard coating layer is formed on the back surface of the plastic base film to realize scratch resistance, so that the anti-blocking property and the antifouling property are excellent without deterioration of the optical properties, and the scratch resistance on the back side is improved. By confirming, the present invention was completed.

An object of the present invention is to provide a double-sided hard coating film excellent in anti-blocking properties and improved antifouling properties.

In order to achieve the above object, the present invention provides a plastic base film, the first hard coating layer formed on one surface of the plastic base film, the anti-blocking layer and a surface water contact angle formed on the first hard coating layer to meet 90 to 120 ° and the plastic Comprising a second hard coating layer formed on the back of the base film, and provides a double-sided hard coating film for display protection that the static friction coefficient (μ) between the anti-blocking layer and the second hard coating layer satisfies 0.3 or less.

In this case, the first hard coating layer or the second hard coating layer is a photocured composition containing 0.1 to 5 parts by weight of the photopolymerization initiator with respect to 100 parts by weight of the ionizing radiation curable resin mixture, the anti-blocking layer is an ionizing radiation curable resin mixture The composition containing 0.1 to 60 parts by weight of the inorganic particles, 0.1 to 30 parts by weight of the antifouling additive and 0.1 to 5 parts by weight of the photopolymerization initiator is photocured to form fine roughness on the surface based on 100 parts by weight.

Furthermore, the composition constituting the hard coating layer and the antiblocking layer may further contain 30 to 70 parts by weight of one or more solvents selected from the group consisting of toluene, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone.

The ionizing radiation curable resin mixture is an ionizing radiation curable resin comprising at least one skeleton structure selected from the group consisting of (meth) acrylic resins, polyurethane resins, polyester resins, polyether resins, olefin resins and polyimide resins,

Pentaerythritol triacrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, trimethylolpropane tri (meth) acrylate and ditrimethylolpropane tetra (meth It is preferred that at least one polyfunctional monomer selected from the group consisting of acrylates or at least one polyfunctional oligomer selected from the group consisting of urethane (meth) acrylate oligomers and polyester (meth) acrylate oligomers is mixed.

The inorganic particles applied to the anti-blocking layer preferably have an average particle size of 0.01 to 1 μm, and a metal oxide or clay material made of silica, alumina and zirconium oxide may be used.

The inorganic particles may be used by surface treatment with organic compounds such as silane coupling agents, polyols, alkalolamines, titanate coupling agents.

In addition, the antifouling additive applied to the anti-blocking layer may be a silicon compound having a molecular weight of 100 to 10,000 or a fluorine-based compound having a molecular weight of 100 to 10,000.

Further, the first hard coating layer is preferably 0.5 to 20㎛ thick, the second hard coating layer is preferably 0.5 to 10㎛ thick, the anti-blocking layer is preferably 0.01 to 2㎛ thick.

The display protective double-sided hard coating film of the present invention sequentially forms a first hard coating layer and an anti-blocking layer having anti-blocking property and antifouling property on one surface of the plastic base film, and implements scratch resistance on the back side of the plastic base film. 2 By forming the hard coating layer, it is excellent in anti-blocking property and antifouling property without deterioration of optical properties, and can prevent scratches on the back side, so it is excellent as a hard coating film for display protection, especially as a touch screen protective film for touch screens. The application of is excellent.

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

The present invention provides a plastic base film, a first hard coating layer formed on one surface of the plastic base film, an anti-blocking layer having a surface water contact angle formed on the first hard coating layer meeting 90 to 120 °, and a second formed on the back surface of the plastic base film. It is composed of a hard coating layer, and provides a double-sided hard coating film for display protection that the static friction coefficient between the anti-blocking layer and the second hard coating layer satisfies 0.3μ or less.

Referring to FIG. 1 corresponding to an example of the present invention, the present invention implements surface hardness improvement by forming hard coating layers 20 and 30 on both sides of the plastic base film 10, and in particular, the first hard coating layer 20. By stacking the anti-blocking layer 30 on which fine irregularities are formed, the regular friction coefficient with the second hard coating layer 40 is controlled to 0.3 μ or less, thereby securing anti-blocking property, and the anti-blocking layer ( 30) can ensure an excellent antifouling property of the surface water contact angle of 90 ° or more, preferably 90 to 120 ° by containing an appropriate amount of antifouling additives.

In addition, the present invention is excellent in light transmittance and haze of 5% or less, preferably 2% or less, even if an antiblocking layer having a thickness of 0.01 to 2 μm containing particles of 0.01 to 1 μm is separately formed on the first hard coating layer. Since the transmission image of the screen is unclear or difficult to recognize the screen can be minimized.

Hereinafter, each component layer of the present invention will be described in detail.

1. Plastic base film (10)

The plastic base film applicable to the present invention is not particularly limited as long as it is highly transparent, but in consideration of optical properties, the thickness of the base film is preferably 10 to 300 μm, and particularly, polyethylene terephthalate, polyethylene naphthalate, polypropylene terephthalate, Polyester films such as polybutylene terephthalate and polypropylene naphthalate can be used.

The plastic base film may be a composite film having a laminated structure of two or more layers, and as a composite film, a composite film containing particles in the surface layer portion without coarse particles in the inner layer portion, and having coarse particles in the inner layer portion. A composite film containing microparticles in the surface layer portion and a composite film having a layer containing fine bubbles in the inner layer portion may be used, and the composite film may be chemically heterogeneous or homogeneous in the polymer forming the inner layer portion and the surface layer portion.

In this case, the plastic base film 10 may be subjected to a surface treatment for the purpose of improving the adhesion between the first hard coating layer 20 and the second hard coating layer 40, a preferred example of the surface treatment is chemical treatment, Mechanical treatment, corona discharge treatment, high frequency treatment, active plasma treatment, and the like, and chemical treatment, glow discharge treatment, and UV treatment are more preferable. In particular, the chemically treated plastic base film reduces the light reflectance on the surface of the film. It is suitable for use for optics because it increases the light transmittance.

2. The first Hard coating layer  (20)

The first hard coating layer 20 may be formed by applying a hard coating composition solution containing 0.1 to 5 parts by weight of a photopolymerization initiator to 100 parts by weight of the ionizing radiation curable resin mixture on one surface of the plastic base film 10, and then curing the hard coating layer 20. have.

The ionizing radiation curable resin mixture is a mixture of a polyfunctional monomer or a polyfunctional oligomer for improving the degree of curing in the ionizing radiation curable resin, the mixing ratio is preferably 1: 5 to 5: 1, the ionizing radiation curable resin When the ratio of the polyfunctional monomer or the polyfunctional oligomer to the ratio exceeds 1: 5, the degree of curing is too high to form curls or cracks well in the direction of the hard coating layer, and when less than 5: 1, the degree of curing is low to provide sufficient hardness characteristics in the hard coating layer. Difficult to get.

The ionizing radiation curable resin preferably includes (meth) acrylic resins, polyurethane resins, polyester resins, polyether resins, olefin resins, and polyimide resins in the skeleton structure, and the number of repeating units of the resin is 3 to 10. Polymer oligomers are used.

More specifically, as the resin containing the (meth) acrylic resin in the skeletal structure, a resin obtained by polymerizing or copolymerizing a (meth) acrylic monomer or a resin copolymerizing a (meth) acryl monomer with a monomer having another ethylenically unsaturated double bond The resin containing the polyurethane resin in the skeletal structure includes a resin containing a urethane bond in the molecular chain.

In addition, the resin containing the polyester resin in the skeletal structure includes unsaturated polyester resins, alkyd resins, polyethylene terephthalates, etc., as resins containing ester bonds in the molecular chain, and resins containing the polyether resin in the skeletal structure. Is a resin containing an ether bond in the molecular chain, polyethylene glycol, polypropylene glycol, polytetramethylene glycol and the like.

In addition, the resin containing the olefin resin in the skeleton structure includes polyethylene, polypropylene, ethylene and propylene copolymer, ethylene and vinyl acetate copolymer, ionomer, ethylene and vinyl alcohol copolymer, ethylene and vinyl chloride copolymer, and the like. The resin containing the polyimide resin in the skeletal structure may be a copolymer containing an imide bond in a molecular chain and a copolymer composed of two or more kinds of the skeletal structure or a copolymer composed of the skeletal structure and other monomers. have.

The multifunctional monomer and the multifunctional oligomer are for increasing the degree of curing of the composition, it is preferable that the multi-functional containing three or more functional groups.

In this case, the polyfunctional monomer may be a de-alcohol reactant between (meth) acrylate and a polyhydric alcohol, specifically pentaerythritol triacrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta At least one selected from the group consisting of (meth) acrylate, trimethylolpropane tri (meth) acrylate and ditrimethylolpropane tetra (meth) acrylate is preferred.

The polyfunctional oligomer is a urethane (meth) acrylate oligomer or polyester (meth) acrylate oligomer, the polyfunctional oligomer may be one or more or a copolymer consisting of the oligomer and a monomer of a different type, may also be used as a repeating unit Is 3 to 10, and may be used by copolymerizing with a low molecular weight substance having a weight average molecular weight of less than 8,000.

The photopolymerization initiator to be applied in the present invention is not particularly limited, but benzophenones, acetphenones, hydroxycyclohexylphenyl ketones, thioxanthones, dibenzyl disulfite, diethyl oxide, triphenylbiimidazole and isopropyl- One or more selected from the group consisting of N, N-methylaminobenzoates can be used.

At this time, the content of the photopolymerization initiator is included in 0.1 to 5 parts by weight based on 100 parts by weight of the ionizing radiation curable resin mixture, if the content is less than 0.1 parts by weight, there is a problem that the photocuring is not sufficient, the content is more than 5 parts by weight There is no problem in curing, but when left for a long time by the remaining initiator, an initiator may precipitate on the surface or a change in properties of the hard coat layer may occur.

In addition, the hard coating composition may further include 30 to 70 parts by weight of the solvent with respect to 100 parts by weight of the total content, the solvent is a ketone, ester, aliphatic hydrocarbon, halogenated hydrocarbon, aromatic hydrocarbon, amine, Water, alcohol and the like can be used without limitation as long as it is a liquid having a boiling point of 60 to 170 ° C, and particularly preferably at least one selected from the group consisting of toluene, mail ethyl ketone, methyl isobutyl ketone and cyclohexanone is used. Can be.

Further, the first hard coating layer is formed by applying a hard coating composition on the plastic base film and then curing, and as the active line, acrylic vinyl such as ultraviolet rays, electron beams and radiation (α rays, β rays, γ rays, etc.) Electromagnetic waves that polymerize the group can be applied, and ultraviolet rays are practically preferred because they are simple.

At this time, the first hard coating layer is a thickness is determined depending on the application is 0.5 ~ 20㎛, more preferably 1 ~ 15㎛. If the thickness of the hard coating layer is less than 0.5㎛, even if fully cured, because the thickness is too thin, there is a problem that the hard coating layer is damaged due to insufficient surface hardness, if the thickness of the hard coating layer exceeds 20㎛ stress such as bending There is a problem that a crack occurs in the hard coat layer is not preferable.

3. Anti-blocking layer (30)

The antiblocking layer 30 is 0.1 to 60 parts by weight of inorganic particles, 0.1 to 30 parts by weight of antifouling additives and 0.1 to 5 parts by weight of the photopolymerization initiator with respect to 100 parts by weight of the ionizing radiation curable resin mixture on the first hard coating layer 20. After coating the composition solution for the anti-blocking layer comprising a part, it is formed by curing, to implement anti-blocking properties and antifouling properties.

The ionizing radiation curable resin mixture applied to the antiblocking layer 30 is the same as the composition described in the first hard coat layer 20.

Inorganic particles to be applied to the present invention are to improve the surface hardness of the film and to form anti-corrugation on the surface to impart antiblocking properties. In order to facilitate dispersion in a solution, a silane coupling agent, a polyol, an alkylol Preference is given to at least one selected from the group consisting of silica, alumina, metal oxides, zirconium oxide and clay surface treated with organic compounds such as amines, titanate coupling agents.

The inorganic particles are not particularly limited but have a spherical shape, a cube shape, a spindle shape, an indefinite shape, and an average particle diameter of 0.01 to 2 μm may be used, and if the size is less than 0.01 μm, surface hardness and anti blocking properties If this value is not sufficient and the thickness exceeds 2 µm, the transmittance is 90% or less, the haze value is 2% or more, and the visibility is lowered.

The inorganic particles may be included in an amount of 0.1 to 60 parts by weight, preferably 1 to 30 parts by weight, based on 100 parts by weight of the ionizing radiation curable resin mixture to have a static friction coefficient of 0.3 μm or less, more preferably, between the antiblocking layer and the second hard coating layer. Can be controlled to 0.1 to 0.3μ.

At this time, if the inorganic particle content is less than 0.1 parts by weight, there is a problem that the surface hardness (pencil hardness) and anti-blocking properties of the hard coating film is not sufficient, if the content exceeds 60 parts by weight hard coating due to insufficient dispersion in the solution The haze of a film shows the value of 15% or more, and there exists a problem of poor visibility.

The antifouling additive to be applied to the present invention preferably has an average molecular weight of 100 to 10,000, and if the average molecular weight is less than 100, the antifouling property is reduced.

In addition, the antifouling additive may be preferably a resin containing a silicon compound or a fluorine compound, the silicon compound is not particularly limited as long as the compound having a siloxane (Si-O) bond, the molecular weight of 100 ~ 10,000 of the liquid (Meth) acrylate polysiloxane compounds or (meth) acrylate organo-modified polysiloxane compounds can be preferably used.

The resin containing the fluorine-based compound is a resin containing a structure in which part or all of hydrogen of polyethylene is substituted with fluorine, and a compound having a molecular weight of 100 to 10,000 is preferable.

At this time, the content of the antifouling additive is contained in 0.1 to 30 parts by weight based on 100 parts by weight of the ionizing radiation curable resin mixture, the anti-blocking layer surface can control the water contact angle of 90 ° or more, more preferably 90 to 120 ° have. In particular, when the antifouling additive content is less than 0.1 parts by weight, the antifouling function is not sufficient, and when it exceeds 30 parts by weight, there is a problem of lowering the surface hardness is not preferable.

Further, the photopolymerization initiator to be applied in the present invention is not particularly limited, but benzophenones, acetphenones, hydroxycyclohexylphenyl ketones, thioxanthones, dibenzyl disulfite, diethyl oxide, triphenylbiimidazole and iso One or more selected from the group consisting of propyl-N, N-tomethylaminobenzoate can be used.

In this case, the content of the photopolymerization initiator is included in 0.1 to 5 parts by weight based on 100 parts by weight of the ionizing radiation curable resin mixture, and if the content is less than 0.1 parts by weight, there is a problem that the photocuring is not sufficient, and the content is more than 5 parts by weight. Although there is no problem in curing, the initiator may precipitate on the surface or change in the properties of the anti-blocking layer when left for a long time by the remaining initiator.

In addition, the composition for the anti-blocking layer may further comprise 30 to 97 parts by weight of a solvent based on 100 parts by weight of the total content, the solvent is a ketone, ester, aliphatic hydrocarbon, halogenated hydrocarbon, aromatic hydrocarbon, amine In general, water, alcohol, etc. can be used without limitation as long as the boiling point is a liquid of 60 ~ 170 ℃, particularly preferably at least one selected from the group consisting of toluene, mail ethyl ketone, methyl isobutyl ketone and cyclohexanone Can be used.

The method of forming the anti-blocking layer is the same as the first hard coating layer 20 described above, the thickness of the anti-blocking layer is preferably 0.01 ~ 2㎛. If the thickness is less than 0.01 µm, there is a problem that the inorganic particles are hardly fixed to the antiblocking layer. If the thickness exceeds 2 µm, the haze shows a value of 1% or more, which is not preferable because of problems in visibility.

4. Second Hard coating layer 40

The second hard coating layer 40 is to prevent scratches that may occur during the manufacturing process of the hard coating film, the photopolymerization initiator 0.1 to 5 with respect to 100 parts by weight of the ionizing radiation curable resin mixture on the back surface of the plastic base film 10 It may be formed by applying a hard coat composition containing a weight part and then curing.

In this case, although the inorganic coating may be further included in the hard coating composition, when the antifouling additive is included, there is a problem in that adhesion to other layers such as a printing layer, an adhesive layer, and a transparent electrode is lowered on the back of the hard coating film. It is preferable not to.

The description of the composition for forming the second hard coat layer 40 is the same as the composition of the first hard coat layer 20 described above, the formation method thereof is also the same.

It is preferable that the second hard coating layer 40 is 0.5 to 10 μm thick, and since only a simple scratch generated during the process may be prevented, the pencil hardness may be lower than that of the first hard coating layer 20, and more preferably 1H or more. Do.

Furthermore, in order to show a logo, a company name, or a brand name on the second hard coating layer 40 within a range in which the desired effect of the present invention is not impaired, a printing layer such as a pattern printed by ink printing or other methods Can be formed.

That is, in the double-sided hard coating film for display protection of the present invention, the first hard coating layer 20 for realizing surface hardness on one surface of the plastic base film 10 and the anti-blocking layer 30 for implementing antiblocking and antifouling properties are sequentially And a second hard coating layer 40 having scratch resistance on the back surface thereof, and having excellent surface hardness of the hard coating film and at the same time, static friction between the anti-blocking layer 30 and the second hard coating layer 40. Coefficient is controlled to 0.3μ or less, excellent antiblocking property.

In addition, the anti-blocking layer 30 may be applied to various screen display devices as the surface water contact angle is maintained at 90 to 120 degrees to improve antifouling properties, and may be particularly useful for a touch panel of a touch screen.

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

The following examples are merely illustrative of the present invention, but the scope of the present invention is not limited to the following examples.

< Example  1>

1. The first Hard coating layer  formation

5 parts by weight of a photoinitiator (100% solids) (Ciba Specialty Chemicals, IRGACURE-184 model) is added to 100 parts by weight of an ionizing radiation curable resin mixture (100% solids) (model UV-9100B, manufactured by Nippon Synthetic Chemical Co., Ltd.). Thereafter, the mixture was diluted with a mixed solvent of 1: 1 by weight ratio of methyl isobutyl ketone and propylene glycol monoethyl ether so that the total solid concentration was 45 parts by weight, and a hard coating solution was prepared.

The hard coating solution uniformly mixed on one surface of a polyester substrate film (Toray Co., Ltd., Lumirror model) having a thickness of 100 μm was applied by using a microgravure coater, dried at 80 ° C. for 2 minutes, and then Irradiation and curing were performed under conditions of an accumulated light amount of 300 mJ / cm ² to form a first hard coat layer having a thickness of 6 μm.

2. Anti-blocking layer  formation

5 parts by weight of photoinitiator (100% solids) (Shiba Specialty Chemicals, IRGACURE-184 model) with respect to 100 parts by weight of ionizing radiation curable resin mixture (100% solids) After adding 15 parts by weight of the additive (OPTOOL DAC-HP fluorine antifouling additive DAIKIN model) and 15 parts by weight of the surface-treated silica particles (Nano Resin, Nanopole C model), methylisobutyl was added so that the total solid concentration was 6 parts by weight. A coating solution for antiblocking was prepared by diluting with a mixed solvent of a ketone and propylene glycol monoethyl ether in a weight ratio of 1: 1.

The antiblocking coating liquid uniformly mixed on the first hard coating layer was applied using a microgravure coater, dried at 80 ° C. for 2 minutes, and then irradiated and cured under conditions of an accumulated light amount of 300 mJ / cm ² of a high pressure mercury ultraviolet lamp. The antiblocking layer having a thickness of 0.3 μm was formed by the treatment.

3. Second Hard coating layer  formation

5 parts by weight of a photoinitiator (100% solids) (Shiba Specialty Chemicals, IRGACURE-184 model) is added to 100 parts by weight of an ionizing radiation curable resin mixture (100% solids) (Model UV-9100B, manufactured by Nippon Synthetic Chemical Co., Ltd.). Thereafter, the mixture was diluted with a mixed solvent of 1: 1 by weight ratio of methyl isobutyl ketone and propylene glycol monoethyl ether so that the total solid concentration was 45 parts by weight, and a hard coating solution was prepared.

The hard coating solution was applied to the back surface of the film on which the first hard coating layer was formed by using a microgravure coater, dried at 80 ° C. for 2 minutes, and then irradiated and cured under conditions of a cumulative light amount of 300 mJ / cm ² of a high pressure mercury ultraviolet lamp. By processing to form a second hard coat layer having a thickness of 3㎛, to prepare a double-sided hard coat film.

< Example  2>

Except for adding 10 parts by weight of the antifouling additive during the anti-blocking layer forming process, it was carried out in the same manner as in Example 1 to prepare a double-sided hard coating film.

< Example  3>

Except for adding 20 parts by weight of silica particles in the anti-blocking layer forming process, it was carried out in the same manner as in Example 1 to prepare a double-sided hard coating film.

< Comparative Example 1 >

Except that the anti-blocking layer was omitted, the same process as in Example 1 A hard coat film was prepared.

< Comparative Example 2 >

Except for omitting silica particles during the anti-blocking layer forming process, it was carried out in the same manner as in Example 1 to prepare a double-sided hard coating film.

< Comparative Example 3 >

Except that the antifouling additive was omitted during the anti-blocking layer formation process, it was carried out in the same manner as in Example 1 to prepare a double-sided hard coating film.

< Comparative Example 4 >

The double-sided hard coating film was carried out in the same manner as in Example 1 except that the anti-blocking layer was diluted with a mixed solvent so that the total solid concentration was 45 parts by weight during the anti-blocking layer forming process and stirred to form an anti-blocking layer having a thickness of 5 μm. Was prepared.

< Comparative Example 5 >

Except that the second hard coating layer was omitted, it was carried out in the same manner as in Example 1 to prepare a hard coating film.

< Comparative Example 6 >

An anti-blocking layer was omitted, and the first hard coating layer further contained 15 parts by weight of an antifouling additive (OPTOOL DAC-HP fluorine-based antifouling additive, DAIKIN model) and 15 parts by weight of surface-treated silica particles (nano resin, Nanopole C model). Except for the formation, it was carried out in the same manner as in Example 1 to prepare a double-sided hard coating film.

< Experimental Example >

1. Pencil hardness measurement

The double-sided hard coat film was measured according to the JIS K-5400 standard using a hardness tester (manufactured by Shintokagaku Co., Ltd., HEIDON model) and described in Table 1 below.

2. Transmittance and Haze  Measure

The transmittance and haze of the double-sided hard coat film were measured using a spectrophotometer (model of Nippon Denshoku, NDH2000), and the results are shown in Table 1 below.

3. Measurement of static friction coefficient (μ)

In order to quantify and compare the anti-blocking properties of the double-sided hard coating film, the static friction coefficient (μ) was measured and described in Table 1 according to the ASTM-1894 standard. It is excellent and anti-blocking property is low when the static friction coefficient is high.

(However, Comparative Examples 1 and 6 have no antiblocking layer, so the surface of the first hard coat layer was measured.)

4. Anti-blocking property  Measure

The double-sided hard coating film was cut out to a size of 3 × 10 cm, and the antiblocking layer and the second hard coating layer were overlapped and sandwiched on a glass plate and left at 200 g / cm ² for 24 hours at room temperature to determine the presence of antiblocking properties with the naked eye.

(However, Comparative Examples 1 and 6 have no antiblocking layer, so the antiblocking properties of the first hard coat layer and the second hard coat layer were measured.)

5. Arithmetic mean roughness ( Ra ) And 10-point average roughness ( Rz ) Measure

The roughness on the surface of the anti-blocking layer of the double-sided hard coating film was measured using a roughness measuring instrument to measure arithmetic average roughness (Ra) and 10-point average roughness (Rz), and are shown in Table 1 below.

(However, Comparative Examples 1 and 6 have no antiblocking layer, so the surface of the first hard coat layer was measured.)

6. Fingerprint Removal Characteristics

After the second hard coating layer of the double-sided hard coating film was treated with a matte black ink, the fingerprints, which were obtained by slowly pressing and contacting the finger on the surface of the anti-blocking layer containing antifouling property, were removed five times using a cloth or the like. Judging by the degree of the trace, "○" was found in the absence of fingerprints, "△" in the presence of weak fingerprints, and "x" in the case of visible fingerprints.

(However, Comparative Examples 1 and 6 have no antiblocking layer, so the surface of the first hard coat layer was measured.)

7. Water contact angle  Measure

In order to confirm the antifouling property of the double-sided hard coating film, a contact angle meter (Kyowa Co., Drop Master 300 model) was added dropwise purified water having a diameter of 2mm on the surface of the anti-blocking layer and the contact angle between the surface of the anti-blocking layer and purified water was measured.

(However, Comparative Examples 1 and 6 have no antiblocking layer, so the surface of the first hard coat layer was measured.)

8. Scratch resistance  Measure

And by applying a load of 250gf / cm ² by using a steel wool (gangcheolsom) on both sides of the hard coating film observed the number of scratches when the round 10, the absence of scratches level 5, if there is a 1 to 5 scratches level 4, 5 to 10 wounds, level 3, 10 or more wounds, level 2, if there is a wound on the entire surface, measured in the level 1, shown in Table 1 below.

division Example Comparative example One 2 3 2 3 4 5 Haze (%) 0.61 0.59 0.73 0.54 0.64 1.28 0.64 Permeability (%) 91.32 91.35 91.32 91.35 91.35 91.22 91.29 Anti-blocking layer Static Friction Coefficient (μ) 0.2 0.2 0.2 0.5 0.2 0.2 0.2 Anti-blocking property ○ ○ ○ Ⅹ ○ ○ ○ Pencil hardness 3H 3H 3H 3H 3H 3H 3H Scratch resistance 5 5 5 5 5 5 5 Ra (μm) 0.0081 0.0083 0.0101 0.0091 0.0042 0.0081 0.0098 Rz (μm) 0.2154 0.2558 0.3004 0.2468 0.0978 0.2154 0.2682 Fingerprint removal ○ ○ ○ ○ △ ○ ○ Water contact angle 108.3 108.2 108.5 108.7 70.8 108.3 108.5 2nd hard coating layer Scratch resistance 4 4 4 4 4 4 -

division Comparative Example 1 Comparative Example 6 Haze (%) 0.55 1.25 Permeability (%) 91.31 91.24 First hard coating layer Static friction coefficient (μ) 0.5 0.2 Anti-blocking property Ⅹ ○ Pencil hardness 3H 3H Scratch resistance 5 5 Ra (μm) 0.0039 0.0085 Rz (μm) 0.0965 0.2187 Fingerprint removal △ ○ Water contact angle 71.3 109.0 2nd hard coating layer Scratch resistance 4 4

According to the results of Tables 1 and 2, in Examples 1 to 3, the first hard coating layer and the anti-blocking layer having anti-blocking properties and antifouling properties were sequentially formed on one surface of the plastic base film, and on the back side of the plastic base film. By forming the second hard coating layer that implements scratch resistance, it was possible to obtain a hard coating film having excellent antiblocking properties and antifouling properties, high surface hardness, and preventing scratches without deteriorating optical properties.

On the other hand, in Comparative Example 1 except the anti-blocking layer was poor antiblocking and antifouling property of the hard coating film, Comparative Example 2 in which the anti-blocking layer does not contain silica particles was poor anti-blocking property, antifouling agent In the case of Comparative Example 3 without the addition of the antifouling property was poor.

In addition, in the case of Comparative Example 4 in which the thickness of the anti-blocking layer was formed to a thickness of 5 μm, and in Comparative Example 6 in which the anti-blocking layer was omitted without introducing the anti-blocking layer, the haze was increased to decrease the optical characteristics. In the case of Comparative Example 3 in which the second hard coat layer was not formed, scratch resistance was poor on the back surface of the film.

As a result of the above, the double-sided hard coating film of the present invention is excellent in light transmittance, haze and visibility, as well as excellent surface hardness and anti-blocking property between the film and at the same time improved antifouling, display device provided in the display material optical material It can be widely used in the device optical film and the screen display device equipped with the optical film.

Applicable technology range of image display surface used for liquid crystal display (LCD), plasma display panel (PDP), electroluminescent display (ELD), cathode ray tube display (CRT), portable digital terminal (PDA), front panel There is an image display member used for protecting the image display device by adhering to the surface of the substrate and the substrate for protecting the mobile device, and is particularly excellent in application to the touch panel of the touch screen.

Although the present invention has been described in detail only with respect to the embodiments described, it will be apparent to those skilled in the art that various modifications and variations are possible within the technical scope of the present invention, and such modifications and modifications belong to the appended claims.

1 It is sectional drawing of the double-sided hard coat film of this invention.

<Code Description of Main Parts of Drawing>

10: plastic base film

20: first hard coating layer

30: anti blocking layer

40: second hard coating layer

Claims (12)

Plastic base film; A first hard coating layer formed on one surface of the plastic base film; An antiblocking layer having a surface water contact angle formed on the first hard coating layer satisfying 90 to 120 °; And A second hard coat layer formed on the rear surface of the plastic base film; Including; Static friction coefficient between the anti-blocking layer and the second hard coating layer Double sided hard coating film for display protection of less than 0.3μ. The display protective double-sided surface of claim 1, wherein the first hard coat layer or the second hard coat layer contains 0.1 to 5 parts by weight of a photopolymerization initiator with respect to 100 parts by weight of the ionizing radiation curable resin mixture. Hard coating film. The composition of claim 1, wherein the antiblocking layer contains 0.1 to 60 parts by weight of inorganic particles, 0.1 to 30 parts by weight of an antifouling additive, and 0.1 to 5 parts by weight of a photopolymerization initiator with respect to 100 parts by weight of an ionizing radiation curable resin mixture. The surface-protective double-sided hard coating film, characterized in that the fine surface is formed on the surface. The display as claimed in claim 2 or 3, wherein the composition further contains 30 to 70 parts by weight of at least one solvent selected from the group consisting of toluene, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone. Protective double sided hard coat film. 4. The at least one skeleton according to claim 2 or 3, wherein the ionizing radiation curable resin mixture is selected from the group consisting of (meth) acrylic resins, polyurethane resins, polyester resins, polyether resins, olefin resins and polyimide resins. To ionizing radiation curable resin containing a structure, Pentaerythritol triacrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, trimethylolpropane tri (meth) acrylate and ditrimethylolpropane tetra (meth At least one multifunctional monomer selected from the group consisting of acrylates, or at least one multifunctional oligomer selected from the group consisting of urethane (meth) acrylate oligomers and polyester (meth) acrylate oligomers Double-sided hard coating film for the display protection. The double-sided hard coating film for display protection according to claim 3, wherein the average particle size of the inorganic particles is 0.01 to 1 µm. The double-sided hard coating film for display protection according to claim 6, wherein the inorganic particles are metal oxides or clays composed of silica, alumina and zirconium oxide. The double-sided hard coating film for display protection according to claim 6, wherein the inorganic particles are surface-treated with one component selected from a silane coupling agent, a polyol, an alcoholic amine or a titanate coupling agent. The double-sided hard coat film for display protection according to claim 3, wherein the antifouling additive is a silicon compound having a molecular weight of 100 to 10,000 or a fluorine compound having a molecular weight of 100 to 10,000. The double-sided hard coating film for display protection according to claim 1, wherein the first hard coating layer has a thickness of 0.5 to 20 µm. The double-sided hard coating film for display protection according to claim 1, wherein the second hard coating layer has a thickness of 0.5 to 10 μm. The double-sided hard coating film for display protection according to claim 1, wherein the anti-blocking layer has a thickness of 0.01 to 2 μm.

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