KR100587441B1 - LCD panel surface protection film - Google Patents

Abstract

Provided is a liquid crystal panel surface protective film having excellent properties such as excellent handleability, easy inspection of a liquid crystal panel with optical evaluation, and excellent anti-dust adhesion to the liquid crystal panel.

A liquid crystal display panel protective film used by adhering to the surface of a polarizing plate or a retardation plate of a liquid crystal display panel, wherein a wear-resistant layer is provided on one surface of a biaxially oriented polyester film having a thickness of 5 to 50 μm, and an adhesive layer is formed on the other surface. The biaxially oriented polyester film has a delay value of 30 to 10,000 nm, the wear resistant layer has a surface resistivity of less than 1 × 10 ¹⁰ Ω and a total light transmittance of the laminated film of 80% or more.

Description

LCD panel surface protection film

The present invention relates to a liquid crystal panel surface protective film, and more particularly, to a liquid crystal panel surface protective film used for protecting the surface of a polarizing plate or a retardation plate by adhering to the surface of a polarizing plate or a retardation plate of a liquid crystal display panel.

Usually, a liquid crystal display panel is produced by laminating | stacking a polarizing plate or a phase difference plate on both surfaces of the liquid crystal cell which enclosed the liquid crystal between two board | substrates. And a protective film is adhere | attached on the surface of a polarizing plate or a retardation plate in order to prevent abrasion of the surface of a polarizing plate or a retardation plate, or dust adhesion in the distribution process or the assembly process of various display apparatuses, such as a computer, a word processor, and a television. Such a protective film is peeled off as an unnecessary substance after playing a protective role of a polarizing plate or a retardation plate. Usually, peeling removal of a protective film is performed by the method of crimping | bonding an adhesive tape to a protective film and lifting an adhesive tape.

Conventionally, polyethylene film, ethylene vinyl acetate copolymer film, etc. are used as said protective film. However, since the protective film may interfere with the inspection involving the optical evaluation of the display ability, color, contrast, and foreign matter mixing of the liquid crystal panel, a defect that must be peeled off at the time of inspection and attached after the completion of the inspection. have.

Patent Publication No. 4-30120 discloses a protective film in which a light isotropic adhesive resin layer is laminated on a light isotropic base film as a protective film that does not need to be peeled off during an inspection involving optical evaluation. However, since this protective film is manufactured by the casting | flow_spread method as a base film, since it uses the film of the near-amorphous state hardly oriented, it cannot be said that it is enough from a viewpoint of chemical resistance, abrasion resistance, etc. .

The present invention has been carried out in view of the above circumstances, and an object thereof is a liquid crystal display panel having characteristics such as excellent handling properties, easy inspection of a liquid crystal display panel with optical evaluation, and excellent adhesion of dust to the liquid crystal display panel. It is to provide a surface protective film.

That is, the gist of the present invention is a liquid crystal display panel surface protection film which is used by adhering to the surface of a polarizing plate or a retardation plate of a liquid crystal display panel, wherein a wear-resistant layer is provided on one surface of a biaxially oriented polyester film having a thickness of 5 to 50 μm. The biaxially oriented polyester film has a retardation value of 30 to 10,000 nm, the surface resistivity of the wear resistant layer is less than l × 10 ¹⁰ Ω, and the total light of the laminated film. The transmittance | permeability is 80% or more, The liquid crystal display panel surface protection film characterized by the above-mentioned.

Hereinafter, the present invention will be described in detail. The liquid crystal display panel surface protection film of this invention is used by adhering to the surface of the polarizing plate or retardation plate of a liquid crystal display panel, and is provided with the wear-resistant layer on one surface of a biaxially-oriented polyester film, and also provided the adhesive layer on the other surface. Made of film. And in a preferable aspect of this invention, a release film is laminated | stacked on the surface of an adhesion layer. The liquid crystal panel surface protection film of this invention is generally manufactured through the wear-resistant layer forming process, the adhesion layer forming process, and the release film lamination process sequentially.

In the present invention, a biaxially oriented polyester film (hereinafter abbreviated as a film) is a film obtained by stretching and orienting a sheet melt-extruded from an extrusion die in a biaxial direction in a longitudinal direction and a transverse direction by a so-called extrusion method.

Polyester constituting the film refers to a polyester obtained by polycondensing aromatic dicarboxylic acid and aliphatic glycol. As aromatic dicarboxylic acid, terephthalic acid, 2, 6- naphthalenedicarboxylic acid, etc. are mentioned, As aliphatic glycol, ethylene glycol, diethylene glycol, 1, 4- cyclohexane dimethanol, etc. are mentioned. Representative polyesters include polyethylene terephthalate (PET), polyethylene-2,6-naphthalenedicarboxylate (PEN) and the like.

The polyester is preferably a copolymer containing a third component. As dicarboxylic acid component of such copolyester, isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, oxycarboxylic acid (for example, P-oxybenzoic acid etc.) is mentioned, As a glycol component Ethylene glycol, diethylene glycol, propylene glycol, butanediol, 1, 4- cyclohexane dimethanol, neopentyl glycol, etc. are mentioned. It is preferable that the said dicarboxylic acid component and the glycol component use 2 or more types together.

In this invention, when handling property is considered, it is preferable to contain particle | grains in a film on the conditions which do not impair transparency. Examples of the particles include silicon dioxide, calcium carbonate, aluminum oxide, titanium dioxide, kaolin, talc, zeolite, lithium fluoride, barium sulfate, carbon black, and heat resistant polymer fine powder as described in Japanese Patent Publication No. 59-5216. Can be. It is preferable that these particles use 2 or more types together. The average particle diameter of the particles is usually 0.02 to 2 µm, preferably 0.05 to 1.5 µm, and more preferably 0.05 to 1 µm. The content of the particles is usually 0.01 to 2% by weight, preferably 0.02 to 1% by weight.

As a method of containing a particle | grain in a film, a well-known method can be employ | adopted. For example, the particles may be added at any stage of the polyester manufacturing process. In particular, in the step before the start of the polycondensation reaction after the esterification step or the end of the transesterification reaction, it is preferable to perform the polycondensation reaction by adding a slurry dispersed in ethylene glycol or the like. In addition, a method of mixing a slurry obtained by dispersing particles in ethylene glycol or water and a polyester raw material using a kneading extruder with Poaful, a method of mixing dried particles and a polyester raw material using a kneading extruder, and the like may also be adopted. .

The production of the film is carried out by a method in which the sheet melt-extruded from the extrusion die is stretched and oriented in the biaxial direction in the longitudinal direction and the transverse direction according to the extrusion method.

In the extrusion method, the polyester is melt-extruded from the extrusion die, and cooled and solidified in a cooling roll to obtain an unstretched sheet. In this case, in order to improve the planarity of the sheet, it is necessary to improve the adhesion between the sheet and the rotary cooling drum, and electrostatically applied adhesion or liquid coating adhesion is preferably adopted. In the electrostatic application bonding method, a linear electrode is usually placed on the surface side of a sheet in a direction that is directly parallel to the flow of the sheet, and a static voltage is applied to the sheet by applying a DC voltage of about 5 to 10 kV to the electrode, thereby providing a sheet and a drum. It is a method of improving the adhesiveness of the. Moreover, the liquid coating adhesion method is a method of improving the adhesiveness of a drum and a sheet | seat by apply | coating a liquid uniformly to the whole or part (for example, only the part which contacts both ends of a sheet) of the surface of a rotary cooling drum. In this invention, it is preferable to use both together as needed.

In stretching in the biaxial direction, first, the unstretched sheet is stretched in one direction by a drawer of a roll or a tenter type. The stretching temperature is usually 70 to 120 ° C, preferably 80 to 10 ° C, and the draw ratio is usually 2.5 to 7 times, preferably 3.0 to 6 times. Subsequently, it extends in the direction orthogonal to a one-step extending | stretching direction. Drawing temperature is 70-120 degreeC normally, Preferably it is 80-115 degreeC, A draw ratio is 3.0-7 times normally, Preferably it is 3.5-6 times. Subsequently, heat treatment is carried out at a temperature of 170 to 250 ° C. under tension or within 30% of relaxation to obtain a biaxially oriented film.

In the said stretching, the method of extending | stretching one direction to two or more steps can be employ | adopted. In that case, it is preferable to make the draw ratio of two directions finally become the said range, respectively. The unstretched sheet may be biaxially stretched at the same time so that the area magnification is 10 to 40 times. Further, if necessary, stretching may be performed in the second longitudinal and / or transverse direction before or after the heat treatment.

In the present invention, the film should have a thickness of 5 to 50 µm and a Retardation value of 30 to 10,000 nm. If the thickness of the film is less than 5 μm, the surface protective property of the liquid crystal panel is lowered, and the handleability is poor in the wear resistant layer forming step or the adhesion layer forming step, and when the thickness of the film exceeds 50 μm, the retardation value is increased and A decrease in the total light transmittance causes a problem when an inspection involving optical evaluation such as display ability, color, contrast, and foreign matter mixing is performed on the liquid crystal display panel. If the retardation value is less than 30 nm, the chemical resistance of the film is deteriorated. If the retardation value is more than 10, OOOnm, the matting state becomes a cross nicol state between the polarizing plate and the protective film by the angle θ3 of the alignment axis of the film. The thickness of the film is preferably 10 µm to 40 µm, and the retardation value is preferably 50 to 5000 nm, more preferably l00 to 2000 nm.

In the present invention, the constituent material of the wear resistant layer includes, for example, various crosslinkable resins, metal oxides, hard carbon materials, and the like. Specific examples of the crosslinkable resin include copolymer resins of silicon-containing compounds and fluorine-containing compounds, in addition to acrylic resins, urethane resins, melamine resins, epoxy resins, and organic silicate resins.

In the present invention, an active energy ray cured resin is suitably used from the viewpoint of productivity and the like. Examples of the active energy ray curable resins include unsaturated polyester resins, acrylic resins, addition polymerization resins, hybrid resins of thiol and acrylic resins, cationic polymerization resins, hybrid resins of cationic polymerization and radical polymerization. Among them, acrylic resins are preferable from the viewpoints of curability, abrasion resistance, surface hardness, crosslinkability and durability.

The acrylic resin contains an acrylic oligomer and a reactive diluent as the active energy ray polymerization component. And it contains a photoinitiator, a photoinitiator, adjuvant, etc. as needed.

Typical examples of the acrylic oligomer include oligomers in which a reactive acryloyl group or a methacryloyl group is bonded to an acrylic resin skeleton. As other acrylic oligomer, polyester (meth) acrylate, epoxy (meth) acrylate, urethane (meth) acrylate, polyether (meth) acrylate, silicone (meth) acrylate, polybutadiene (meth) acrylate Etc. can be mentioned. Moreover, the oligomer which the melamine, the isocyanuric acid, the cyclic hose spazen etc. couple | bonded with the acryloyl group or the methacryloyl group which are rigid skeletons is mentioned.

The reactive diluent is a copolymer component of the coating film because the reactive diluent has a function of a solvent in the coating step as a medium of the coating agent and itself has a group that reacts with a polyfunctional or monofunctional acrylic oligomer. As a specific example of such a reactive diluent, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, di Pentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, trimethylolpropane tri (meth) acrylate, ethylene glycol (meth) acrylate, propylene glycol di (meth) acrylate, (meth ) Acryloyloxypropyl triethoxysilane, (meth) acryloyloxypropyl trimethoxysilane, etc. are mentioned.

As a photoinitiator, 2, 2-ethoxy acetophenone, l-hydroxycyclohexyl phenyl ketone, dibenzoyl, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, p-chlorobenzophenone, for example , p-methoxybenzophenone, mysler ketone, acetophenone, 2-chlorothioxanthone, anthraquinone, phenyldisulfide, 2-methyl- [4- (methylthio) phenyl] -2-morpholine-1- Propanone etc. are mentioned.

Examples of the photopolymerization initiation aid include tertiary amines such as triethylamine, triethanolamine, and 2-dimethylaminoethanol, alkylphosphines such as triphenylphosphine, and thioethers such as β-thiodiglycol.

Examples of the modifier include an applicability improving agent, an antifoaming agent, a thickener, inorganic particles, organic particles, lubricants, organic polymers, dyes, pigments, stabilizers and the like. These are used in the range which does not inhibit reaction by an active energy ray, and can improve the characteristic of an active energy ray hardening resin layer according to a use. An organic solvent can be mix | blended with the composition of an active energy ray hardening resin layer for the improvement of workability at the time of coating, and control of coating thickness.

In this invention, the following method can be employ | adopted in order to provide antistatic property to a liquid crystal display surface protection film. That is, (l) a method of depositing a conductive material such as chromium deposition on a film, (2) a method of putting an antistatic agent into a film and putting it in, (3) a method of providing an antistatic agent-containing coating layer on a film, and (4) abrasion resistance The method etc. which contain an antistatic agent in a layer can be employ | adopted. Among these, the method of (3) or (4) is preferable.

As the antistatic agent, for example, various cationic antistatic agents having cationic groups such as quaternary ammonium salts, pyridinium salts and primary to tertiary amino groups, anionic such as sulfonate groups, sulfuric acid ester bases, phosphate ester bases and phosphonate groups Various surfactant type antistatic agents, such as anionic antistatic agent which has a group, amphoteric antistatic agents, such as amino acid type, amino sulfate ester type, nonionic antistatic agents, such as amino alcohol type, glycerin type, and polyethylene glycol type, or charging as mentioned above The polymeric antistatic agent etc. which made the antimicrobial agent high molecular weight are mentioned.

It is preferable that a silicone type compound is contained in a wear resistant layer in order to provide suitable peelability. Silicone oil, silicone resin, silicone rubber, etc. are mentioned as a kind of silicone type compound. Preference is given to compounds in which silicone is the main component. As such a compound, linear dimethylpolysiloxane rubber, organic modified polysiloxane, etc. are mentioned, for example.

The content of the silicone compound in the wear resistant layer is usually 0.5 to 60% by weight, preferably 0.5 to 50% by weight, more preferably 1 to 40% by weight. If the content of the silicone compound exceeds 60% by weight, the adhesive strength with the adhesive tape is lowered, so that it is difficult to adhere to the adhesive tape when the protective film is removed. When the cut | disconnected thing is handled by overlapping, there exists a thing which the adhesive of a cut edge adheres to the surface of the protective film of another polarizing plate or retardation plate.

The wear resistant layer is formed by applying a curable resin composition to one surface of the film to cure it. As the coating method, a reverse wool coating method, a gravure roll coating method, a rod coating method, an air knife coating method or the like can be adopted. Curing of the applied curable resin composition is performed by active energy ray or heat, for example. As active energy rays, ultraviolet rays, visible rays, electron beams, X-rays, α-rays, β-rays, γ-rays and the like are used. As a heat source, an infrared heater, a heat oven, etc. are used. Irradiation of an active energy ray is normally applied to an application layer, but in order to improve the adhesiveness with a film, it is preferable to perform on the opposite surface of an application layer. It is preferable to use the reflecting plate which can reflect an active energy ray as needed. The film cured by the active energy ray is particularly good in wear resistance.

The thickness of the wear resistant layer is usually in the range of 0.5 to 10 m, preferably 1 to 5 m. When thickness is less than 0.5 micrometer, abrasion resistance falls, and when it exceeds 10 micrometers, hardening shrinkage of a wear resistant layer becomes large and a film may wind up in a wear resistant layer.

In the present invention, the surface resistivity of the wear resistant layer should be less than 1 × 10 ¹⁰ Ω. When the surface resistivity of the wear resistant layer exceeds the above value, static electricity is likely to be generated, and adhesion of dust increases. The surface resistivity of the wearable layer is preferably less than 5 × 10 ⁹ Ω, more preferably less than 1 × 10 ⁹ Ω.

In the present invention, the coefficient of friction for the polyester film of the wear resistant layer is preferably 0.3 or less. The reason for this is as follows. The film which has undergone the wear-resistant layer forming process is stored in an overlapping state before being brought into the adhesion layer forming process. When the friction coefficient of the wear resistant layer exceeds 0.3, the wear resistant layer and the film in contact with the upper and lower sides may be fixed (broken) in the storage and deteriorate in handling. Therefore, in this invention, in order to avoid such a problem, adjustment of the friction coefficient with respect to the polyester film of a wear-resistant layer is preferable. The coefficient of friction for the polyester film of the wear resistant layer is preferably 0.25 or less.

In the present invention, the surface roughness Ra of the wear resistant layer is preferably 0.03 μm or less. That is, when the surface roughness (Ra) of the wear resistant layer exceeds 0.03 μm, there is a problem in inspection involving optical evaluation in the state where the protective film is attached, even if the film thickness and retardation value are within the above ranges due to the decrease in transparency. Can cause. Therefore, in this invention, in order to perform the said test in the state which attached the protective film without a problem at all, it is preferable to adjust the surface roughness Ra of a wear-resistant layer. The surface roughness Ra of the wear resistant layer is preferably 0.025 μm or less.

In this invention, it is preferable that the peeling force with respect to the following adhesive of a wear-resistant layer is 500 gf / 50 mm or less. The reason for this is as follows. The liquid crystal display panel surface protection film of this invention is stored in the superposition state. At the time of the said storage, in the cutting process to a predetermined dimension, the adhesive layer accidentally pushed out between a polyester film and a release film may contact the wear-resistant layer of another protective film. The contact of the pressure-sensitive adhesive layer with respect to the wear-resistant layer becomes a cause of adhesion contamination of the pressure-sensitive adhesive with respect to the wear-resistant layer when the adhesive strength of the pressure-sensitive adhesive increases. Therefore, in order to avoid such a problem, in this invention, adjustment of the peeling force with respect to the following adhesive of a wear-resistant layer is preferable.

In the present invention, the pressure-sensitive adhesive layer is composed of known pressure-sensitive adhesives such as acrylic pressure-sensitive adhesives, rubber pressure-sensitive adhesives, block copolymer type pressure-sensitive adhesives, polyisobutylene pressure-sensitive adhesives, silicone pressure-sensitive adhesives, and the like. Generally, such an adhesive consists of compositions, such as an elastomer, a tackifier, a softener (plasticizer), a deterioration inhibitor, a filler, a crosslinking agent.

As an elastic polymer, natural rubber, synthetic isoprene rubber, reclaimed rubber, SBR, block copolymer, polyisobutylene, butyl rubber, polyacrylic acid ester copolymer, silicone rubber etc. are mentioned according to the kind of each said adhesive, for example.

As the tackifier, for example, rosin, hydrogenated rosin ester, terpene resin, aromatic modified terpene resin, hydrogenated terpene resin, terpene phenol resin, aliphatic petroleum resin, aromatic petroleum resin, alicyclic petroleum resin, coumarone Indene resin, styrene resin, alkylphenol resin, xylene resin, etc. are mentioned.

Examples of the softener include paraffinic process oils, naphthalene process oils, aromatic process oils, liquid polybutenes, liquid polyisobutylenes, liquid polyisoprene, dioctylphthalate, dibutylphthalate, castor oil, tall oil, and the like. have.

Examples of the deterioration inhibitor include aromatic amine derivatives, phenol derivatives, and organic thioslates.

Examples of the filler include zincation, titanium white, calcium carbonate, clay, pigments, carbon black, and the like. When a filler is contained, it is used in the range which does not significantly affect the total light transmittance of a protective film.

As the crosslinking agent, for example, sulfur, a vulcanization aid, and a vulcanization accelerator (typically dibutylthiocarbamate zinc or the like) are used for crosslinking the natural rubber adhesive. Polyisocyanate is used as a crosslinking agent which can crosslink the adhesive which uses natural rubber and carboxylic acid copolymer polyisoprene as a raw material at room temperature. Polyalkyl phenol resins are used as crosslinking agents having heat resistance and non-pollution characteristics in crosslinking agents such as butyl rubber and natural rubber. Organic peroxides such as benzoyl peroxide, dicumyl peroxide, and the like are used for the crosslinking of the butadiene rubber, the styrene butadiene rubber, and the natural rubber as a raw material, and a non-polluting adhesive can be obtained. As the crosslinking aid, polyfunctional methacryl esters are used. There exists formation of the adhesive by crosslinking, such as ultraviolet crosslinking and electron beam crosslinking.

Formation of an adhesion layer is performed by the method of apply | coating an adhesive to the other surface of a film. As the coating method, the same method as used for forming the wear resistant layer can be adopted. The thickness of an adhesion layer is 0.5-10 micrometers normally, Preferably it is the range of 1-5 micrometers.

In the present invention, the adhesive force of the pressure-sensitive adhesive layer is adjusted in the same range that the pressure-sensitive adhesive layer is peeled off from the surface of the polarizing plate or the retardation plate, such as a biaxially oriented polyester film, when the pressure-sensitive adhesive tape is squeezed onto the wear-resistant layer. do. In this case, the adhesive force between the polarizing plate or the retardation plate and the adhesive layer is preferably in the range of 5 to 200 gf / 50 mm. And a well-known release film is laminated | stacked on the adhesive layer surface from a viewpoint of the convenience of handleability.

The total light transmittance TL of the laminated film (liquid crystal panel surface protective film) of the present invention configured as described above is 80%, preferably 85% or more. As a result, the test | inspection accompanying optical evaluations, such as the display capability of a liquid crystal display plate, a hue, contrast, and a foreign material mixing, can be made to attach a protective film to the surface of a polarizing plate or retardation plate.

Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited to a following example, unless the summary is exceeded. In addition, in an Example and a comparative example, "part" shows a "weight part." In addition, the measuring method and evaluation criteria used by this invention are as follows.

(1) Thickness of Biaxially Oriented Polyester Film:

The thickness of the film was measured using the Citizen Watch company Mumetron "4M-100P TYPE V-2."

(2) Retardation value (Re) of biaxially oriented polyester film:

The maximum value n (gamma) of refractive index in a film plane, and refractive index n (beta) of the direction orthogonal to it were measured using the Abbe refractometer by the Atago optical company, and the difference (n (gamma) -n (beta)) was computed. The difference (nγ-nβ) was multiplied by the thickness of the film on which the refractive index was measured to be the delay value.

(3) Surface resistivity (Ω) of the wear resistant layer:

Using Hiresta MODEL HT-210 manufactured by Mitsubishi Petrochemical Co., Ltd., samples were installed at 23 ° C./50% RH, and a surface voltage (Ω) was measured after charging for 1 minute (voltage application time 1 minute) by applying a voltage of 500 V. It was. The form of the electrode used here is a concentric circular electrode having an outer diameter of 16 mm of the main electrode and an inner diameter of 40 mm of the counter electrode. The value obtained by multiplying the surface resistivity (Ω) measured by the above device by 10 was used as the surface resistivity (Ω).

(4) friction coefficient of the wear resistant layer:

On a smooth glass plate, two sheets of abrasion-resistant layer surface of a sample film cut to a width of 15 mm and a length of 150 mm and a polyester film (T100-38 manufactured by Diamond Foil) are placed on it, a rubber plate is placed thereon, and a load is placed thereon. The friction force was measured by sliding the film comb at a pressure of 0.5 g / mm ² and a speed of 20 mm / min. The value was calculated from the slip point of 5 mm to obtain a friction coefficient. In addition, the measurement was performed under the temperature of 23 degreeC, and 50% of humidity.

(5) Surface roughness Ra of the wear resistant layer:

Surface roughness with centerline average roughness Ra (μm) is assumed. It was obtained as follows using the surface roughness measuring instrument ("SE-3F" by Kosaka Research Institute). That is, from the film cross-sectional curve, a portion of the reference length L (2.5 mm) is extracted in the direction of the center line, and the roughness curve y = f (x) with the center line of the extraction portion as the y-axis and the direction of the vertical magnification. When expressed by, the value given by the following formula is represented by [μm]. The center line average roughness calculated | required ten cross-sectional curves from the sample film surface, and showed it as the average value of the center line average roughness of the extraction part calculated | required from this cross-sectional curve. The tip radius of the stylus was 2 μm, the load was 30 mg, and the cutoff value was 0.08 mm.

[Equation 1]

(6) Peeling force of the wear-resistant layer to the pressure-sensitive adhesive:

A double-sided adhesive tape (No. 502 manufactured by Nitto Electric Works) was attached on the wear-resistant layer, and a rubber roller was pressed at a linear pressure of 450 g / cm, cut into a width of 50 mm, and used as a sample for measuring the peel force. After being pressed for 1 hour, the resultant was pressed for 1 hour using an Instron tensile tester and peeled at a speed of 300 mm / min, and the average value of the stress was taken as the peel force of the sample. The test was repeated 10 times and the arithmetic mean of 10 times was taken as the peel force. In addition, this test was performed at 23 degreeC and the standard condition of 50% RH.

(7) Total light transmittance (TL) of the laminated film:

In accordance with JIS-K7105, the total light transmittance (TL) was measured by an integrating sphere turbidimeter ("NDH-300A" manufactured by Nippon Denshoku Industries Co., Ltd.).

(8) Handleability:

The handleability of the film in the wear resistant layer forming process or the adhesion layer forming process and the handleability of the laminated film upon adhesion to the deflection plate were evaluated.

(9) Extinction state:

The film containing the foreign material for characterization evaluation was arrange | positioned between the two deflecting plates of a cross nicol state, and the presence or absence of the quenching state when the whole was seen from the top through the sample film was observed.

(10) Wear resistance rating:

Using RUBBING TESTER manufactured by Daepyung Chemical Co., Ltd., a cellulose nonwoven fabric of long fiber was rolled and attached to 65 mm x 50 mm metal flat plate indenter, soaked with 1 ml of ethyl acetate and rubbed the wear-resistant layer surface by 100 round trip. Then, the surface was observed and the case where the wear-resistant layer hardly changed was evaluated as good, and the case where the wear-resistant layer was peeling off as a defect.

(11) Dust Adhesion:

Tobacco material was dropped on the surface of the wear-resistant layer of the laminated film, and the adhesion state of the ash was observed when one rotation (360 degree rotation) was performed to evaluate the presence or absence of dust adhesion.

(12) Broachability:

Two polyester films having a wear resistant layer formed thereon were overlaid, the lower film was fixed, and the upper film was pushed and slipped with a finger to examine the presence or absence of a broken between the wear resistant layer and the polyester film.

(13) ease of inspection:

The film containing the foreign material for evaluation of properties was arrange | positioned between the two deflecting plates of a cross nicol state, and the easiness of seeing the foreign material when the whole was seen from the top through the sample film was evaluated.

(14) adhesive adhesiveness:

An acrylic adhesive was transferred to the surface of the wear resistant layer, and the presence or absence of adhesiveness was evaluated.

Preparation Example 1 (Polyester A)

100 parts of dimethyl terephthalate, 60 parts of ethylene glycol, and 0.09 parts of magnesium acetate and 4 water salts were placed in a reactor, methanol was distilled off while heating up, and a transesterification reaction was carried out. The transesterification reaction was terminated. Subsequently, an ethylene glycol slurry containing 0.1 part of silica particles having an average particle diameter of 1.54 μm was added to the reaction system, and 0.04 part of ethylacetate phosphate and 0.01 part of germanium oxide were added, and then the temperature was maintained at 280 ° C. for 100 minutes. Was reached to 15 mmHg, and then the pressure was gradually reduced to finally 0.3 mmHg. After 4 hours, the system was brought to normal pressure to obtain polyester A. The content of silica particles of polyester A was 0.1% by weight.

Preparation Example 2 (Polyester B)

In Preparation Example 1, except that ethylene glycol slurry containing 0.1 parts of titanium oxide particles having an average particle diameter of 0.27 μm was used instead of 0.1 parts of silica particles having an average particle size of 1.54 μm, as in Preparation Example 1 To obtain polyester B. The content of the titanium oxide particles of the polyester B was 1% by weight.

Production Example 3 (Polyester Film Al)

Polyester A was dried at 180 ° C. for 4 hours under inert gas, melt extruded at 290 ° C. by a melt extruder, and cooled and solidified on a cooling roll set at a surface temperature of 40 ° C. using an electrostatically applied adhesion method. Got. The obtained sheet was stretched at 85 ° C in 3.5-fold longitudinal direction, then stretched at 100 ° C in 3.7-fold transverse direction, and further heat-set at 230 ° C to obtain a polyester film A1 having a thickness of 25 µm. The retardation value of the film was 700 nm.

Production Example 4 (Polyester Film A2)

It carried out like the manufacture example 3 and obtained the polyester film A2 of 38 micrometers in thickness. The retardation value of the film was 990 nm.

Production Example 5 (Polyester Film A3)

It carried out like the manufacture example 3 and obtained the polyester film A3 of thickness 3micrometer. The retardation value of the film was 90 nm.

Production Example 6 (Polyester Film A4)

It carried out like the manufacture example 3 and obtained the polyester film A4 of 75 micrometers in thickness. The retardation value of the film was 2200 nm.

Production Example 7 (Polyester Film A5)

In the manufacture example 3, after extending | stretching in the longitudinal direction, it carried out like manufacture example 3 except having apply | coated the following aqueous dispersion coating liquid so that the application thickness after extending | stretching drying might be 0.1 micrometer, and polyester film A5 was obtained. The delay value of the obtained film was 700 nm.

The aqueous dispersion coating solution was prepared as follows. That is, first, p-styrene sulfonate sodium salt (40 parts), vinyl sulfonate sodium salt (40 parts), and N, N'-dimethylaminomethacrylate (20 parts) are dissolved in distilled water and polymerized while heating and stirring at 60 ° C. Antistatic resin was obtained by adding and polymerizing 2,2'- azobis (2-aminodipropane) dihydrochloride as an initiator.

Then, a polyurethane resin (isocyanate component: isoprone diisocyanate, polyol component: terephthalic acid, isophthalic acid, polyester polyol composed of ethylene glycol, diethylene glycol, chain extender: 2,2- Dimethylol propionic acid) 50 parts, acrylic resin (structural unit: methyl methacrylate, N, N'-dimethylaminoethyl methacrylate, 2-hydroxyethyl methacrylate, butyl acrylate) 10 parts, trifunctional water-soluble epoxy 5 parts of compounds and 5 parts of colloidal silica having an average particle diameter of 0.1 μm were blended to prepare an aqueous dispersion coating liquid.

Production Example 8 (Polyester Film Bl)

In the manufacture example 3, it carried out like manufacture example 3 except having changed polyester A into polyester B, and obtained polyester film B1 of 50 micrometers in thickness. The retardation value of the film was not measurable.

Example 1

Active energy ray-curable resin composition consisting of 30 parts of dipentaerythritol hexaacrylate, 40 parts of tetrafunctional urethane acrylate, 27 parts of bisphenol A type epoxy acrylate and 3 parts of 1-hydroxycyclohexylphenyl ketone, and a quaternary agent as an antistatic agent The ammonium base-containing methacrylimide copolymer was blended in a weight ratio of 95: 5, and applied to one surface of the polyester film A1 so that the thickness after curing was 2 μm. The irradiation distance was 100 mm using a high pressure mercury lamp having a 120 W / cm energy. Irradiated for 15 seconds to form a cured film. And the acrylic adhesive agent was apply | coated to the opposite surface of the hardened film coating surface, and the laminated film was obtained.

Example 2

In Example 1, the laminated | multilayer film was obtained like Example 1 except having formed the wear-resistant hardened film so that the thickness after hardening might be set to 1 micrometer.

Example 3

In Example 1, the laminated | multilayer film was obtained like Example 1 except changing polyester film Al into polyester film A2.

Example 4

Example 1 WHEREIN: Except changing polyester film Al into polyester film A5, and not including a quaternary ammonium base containing methacrylimide copolymer as an antistatic agent in an active energy ray hardening resin composition. A laminated film was obtained as follows.

Comparative Example 1

In Example 1, the laminated | multilayer film was obtained like Example 1 except not having mix | blended the antistatic agent.

Comparative Example 2

In Example 1, the laminated | multilayer film was obtained like Example 1 except not having formed a cured film.

Comparative Example 3

In Example 1, the laminated | multilayer film was obtained like Example 1 except changing polyester film A1 into polyester film A3. By the way, wrinkles entered the whole film and it was a film in question practically.

Comparative Example 4

In Example 1, the laminated | multilayer film was obtained like Example 1 except changing polyester film Al into polyester film A4.

Comparative Example 5

In Example 1, the laminated | multilayer film was obtained like Example 1 except changing polyester film A1 into polyester film B1.

The results of Examples 1 to 4 and Comparative Examples 1 to 5 are shown in Tables 1 and 2 below.

TABLE 1

TABLE 2

Preparation Example 9 (Polyester C)

In Preparation Example 1, poly was prepared in the same manner as in Preparation Example 1 except that instead of an ethylene glycol slurry containing 0.1 parts of silica particles having an average particle size of 1.54 μm, an ethylene glycol slurry containing 0.075 parts of silica particles having an average particle size of 1.54 μm was used. Ester C was obtained. The content of silica particles of Polyester C was 0.075% by weight.

Preparation Example 10 (Polyester D)

In Preparation Example 1, poly was prepared in the same manner as in Preparation Example 1 except that an ethylene glycol slurry containing 0.2 parts of silica particles having an average particle size of 1.54 μm was used instead of 0.1 parts of silica particles having an average particle size of 1.54 μm. Ester D was obtained. The content of silica particles of polyester D was 0.2% by weight.

Production Example 11 (Polyester Film C)

In the manufacture example 3, it carried out like manufacture example 3 except having changed polyester A into polyester C, and obtained polyester film C of thickness 25micrometer. The retardation value of the film was 700 nm.

Production Example 12 (Polyester Film D)

In Production Example 3, a polyester film D having a thickness of 25 μm was obtained in the same manner as in Production Example 3 except that Polyester A was changed to Polyester D. The retardation value of the film was 700 nm.

Example 5

In Example 1, the laminated film was obtained like Example 1 except changing polyester film A1 to polyester film C, and using the coating agent for hardening films of holes. As a coating agent for hardened films, the coating agent prepared by mix | blending linear dimethylpolysiloxane rubber in the weight ratio of 95: 5 was used for the coating agent (mixture of an active energy ray hardening resin composition and an antistatic agent) used in Example 1.

Example 6

In Example 5, the laminated | multilayer film was obtained like Example 5 except having formed the wear-resistant hardened film so that the thickness after hardening might be set to 1 micrometer.

Example 7

In Example 5, the laminated | multilayer film was obtained like Example 5 except changing the coating agent for hardening films of following. As a coating agent for hardened films, the coating agent prepared by mix | blending linear dimethylpolysiloxane rubber in the weight ratio of 98: 2 was used for the coating agent (mixture of an active energy ray hardening resin composition and an antistatic agent) used in Example 1.

The results of Examples 5 to 7 are shown in Tables 3 and 4 below.

TABLE 3

TABLE 4

According to this invention demonstrated above, the liquid crystal display panel surface protection film which has the characteristic of being excellent in handleability, the inspection of the liquid crystal display panel with optical evaluation is easy, and excellent in preventing dust adhesion to a liquid crystal display panel, etc. is provided.

Claims (9)

A liquid crystal display surface protective film used by being adhered to the surface of a polarizing plate or a retardation plate of a liquid crystal display panel, wherein a wear-resistant layer is provided on one surface of a biaxially oriented polyester film having a thickness of 5 to 50 μm, and an adhesive layer is provided on the other surface. The biaxially oriented polyester film has a retardation value of 30 to 10,000 nm, the wear resistant layer has a surface resistivity of less than 1 × 10 ¹⁰ Ω, and the total light transmittance of the laminated film is 80% or more. Liquid crystal panel surface protection film. The film according to claim 1, wherein the wear resistant layer is made of an active energy ray curable resin. The film of claim 1 or 2, wherein wear resistance is provided through an antistatic layer. The film according to claim 1 or 2, wherein the wear resistant layer contains an antistatic agent. The film according to claim 1 or 2, wherein the wear-resistant layer contains a silicone compound. The film according to claim 1 or 2, wherein the coefficient of friction for the polyester film of the wear resistant layer is 0.3 or less. The film of Claim 1 or 2 whose surface roughness Ra of a wear resistant layer is 0.03 micrometer or less. The film according to claim 1 or 2, wherein the adhesive layer comprises at least one member selected from the group consisting of acrylic pressure sensitive adhesives, rubber pressure sensitive adhesives, block copolymer type pressure sensitive adhesives, polyisobutylene pressure sensitive adhesives, and silicone pressure sensitive adhesives. The film of Claim 1 or 2 by which the release film was laminated | stacked on the surface of the adhesion layer.