KR101798655B1 - Composite film for electrostatic capacity type touch screen panel - Google Patents

Abstract

[0001] The present invention relates to a composite film for a capacitive touch panel, and more particularly, to a composite film for a capacitive touch panel that minimizes reflection due to light emitted from a BLU of an LCD and improves transmittance, (Ag) layer of the ITO film of the ITO film and the silver (Ag) layer of the lead wire by integrating the adhesive layer which is formed on the ITO film, will be. To this end, the composite film for a capacitive touch panel according to the present invention comprises a transparent base film and a coating layer of two or more layers having different refractive indices sequentially coated on the base film, wherein the uppermost layer of the coating layer has a low refractive index of 1.31 to 1.40 And a pressure-sensitive adhesive layer formed on the opposite side of the base film on which the coating layer is formed, the pressure-sensitive adhesive layer being coated with a pressure-sensitive adhesive composition comprising a urethane-based copolymer resin, a curing agent and a silane coupling agent.

Description

TECHNICAL FIELD [0001] The present invention relates to a composite film for a capacitive touch panel,

[0001] The present invention relates to a composite film for a capacitive touch panel, and more particularly, to a composite film for a capacitive touch panel that minimizes reflection due to light emitted from a BLU of an LCD and improves transmittance, (Ag) layer of the ITO film of the ITO film and the silver (Ag) layer of the lead wire by integrating the adhesive layer which is formed on the ITO film, will be.

2. Description of the Related Art Generally, a touch screen panel is a device mounted on a surface of a display device to convert physical contact of a user's finger or a touch pen into an electrical signal and output. The touch screen panel includes a liquid crystal display, Display panel (Plasma Display Panel), and EL (Electro-luminescence) devices.

Such a touch panel is largely classified into a capacitive type, a resistive type, an ultrasonic type, and an infrared type according to the operation principle, and both the capacitive type and the resistive type are widely used today. In recent years, a capacitance type having excellent characteristics in terms of durability and transmittance has been spotlighted as compared with the resistance film type.

The structure of such a capacitive touch panel is shown in FIG. 1 is a cross-sectional view of an integrated capacitance type touch screen panel to which a composite film for a capacitive touch panel according to the present invention advanced in the related art is applied. As shown in FIG. 1, there is a printed layer 2 on the edge of a glass for a touch panel, and there is an ITO layer 1 deposited thereon. After the ITO layer 1 is deposited, And the Ag layer 3, which is an outgoing line, is placed on both ends, thereby forming a capacitive touch panel. In Fig. 1, the identification number "9" is described below as a composite film for a capacitive touch panel according to an embodiment of the present invention.

In addition, the adhesive layer of the image quality improving film is in contact with the ITO layer, which is an inorganic substance, and the adhesive force of the adhesive decreases with respect to the inorganic substrate. In addition, the general adhesive layer contains an acid in the functional group, and when the adhesive layer containing an acid is bonded to the ITO film, the Ag layer of the ITO layer and the outgoing wire is oxidized over time, Occurs. In addition, in the touch panel industry, the image quality improvement film and the adhesive film are purchased separately, and the laminating process is outsourced. Since the two films are purchased separately, the problem of defect management in the management problem and outsourcing Price, and low yield.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to minimize the surface reflectance and improve the transmittance to improve the image quality and to prevent the oxidation of the ITO and the Ag paste layer The present invention also provides a composite film for a capacitive touch panel capable of improving adhesion of a substrate to an ITO film as an inorganic material.

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

The above object can be achieved by a transparent substrate film and a coating layer of two or more layers having different refractive indices sequentially coated on the base film, wherein the uppermost layer of the coating layer comprises a coating layer composed of a low refractive index layer having a refractive index of 1.31 to 1.40, And a pressure-sensitive adhesive layer formed on the opposite surface of the film, the pressure-sensitive adhesive layer being coated with a pressure-sensitive adhesive composition comprising a urethane-based copolymer resin, a curing agent and a silane coupling agent.

Here, the low refractive index layer has an average specular reflectance of 0.1 to 1.0% at an incident angle of 5 ° in a wavelength region of 480 to 680 nm.

Preferably, the composite film for a capacitive touch panel has a transmittance and a haze (HAZE) of 93.5% or more and 1.5% or less, respectively.

Preferably, the water contact angle of the low refractive index layer is 85 DEG or less.

Preferably, the urethane-based copolymer resin and the curing agent have an acid-free functional group, and the pressure-sensitive adhesive layer is wet-coated.

Preferably, the current change rate of the base film after formation of the pressure-sensitive adhesive layer coated with the pressure-sensitive adhesive composition comprising the urethane-based copolymer resin is 20% or less.

Preferably, the silane coupling agent is contained in an amount of 0.01 to 1 part by weight based on 100 parts by weight of the urethane-based copolymer resin (based on the solid content).

Preferably, the coating thickness of the pressure-sensitive adhesive layer coated with the pressure-sensitive adhesive composition containing the urethane-based copolymer resin is 10 to 100 탆, and the adhesive force of the pressure-sensitive adhesive composition is 2 to 25 N / 25 mm.

Preferably, the base film is any one of a polyethylene terephthalate (PET) film, a triacetate cellulose (TAC) film, a polypropylene (PP) film, and a polyethylene (PE) film.

According to the present invention, it is possible to improve the image quality by minimizing the reflection of light from the BLU of the LCD and improving the transmittance, and by integrating the adhesive layer not containing an acid, the ITO layer of the ITO film and the outgoing line It is possible to prevent the oxidation of the silver (Ag) layer, thereby securing the electrical stability and simplifying the process and reducing the cost.

1 is a cross-sectional view of an integrated capacitive touch screen panel to which a composite film for a capacitive touch panel according to the present invention is applied.
FIG. 2 is a schematic diagram for testing the current change amount. FIG.

Hereinafter, the present invention will be described in detail with reference to embodiments and drawings of the present invention. It will be apparent to those skilled in the art that these embodiments are provided by way of illustration only for the purpose of more particularly illustrating the present invention and that the scope of the present invention is not limited by these embodiments .

In the case of a film having a general transparent base film and a hard coating layer, since the reflectance of the surface has an average specular reflectance of 3 to 5% at an incident angle of 5 ° in a wavelength range of 480 to 680 nm, Is high, so that a large amount of reflection occurs on the surface, which causes a problem that the image quality of the display is deteriorated by the reflected light. In order to solve the above-mentioned problems, the composite film for a capacitive touch panel according to the present invention comprises two or more coating layers having different refractive indices on a transparent base film, and the uppermost layer has a refractive index of 1.31 To 1.40, thereby improving the image quality by improving the transmittance and minimizing the surface reflectance of the light coming from the outside through the refractive index control layer of multiple layers.

In addition, the pressure-sensitive adhesive layer of the image quality improving film is in contact with the ITO layer, which is an inorganic substance, and a general problem occurs in that the pressure-sensitive adhesive has a low adhesive strength to the inorganic substrate. In order to solve the above problems, the composite film for a capacitive touch panel according to the present invention is characterized by adding a silane coupling agent capable of forming a hydrogen bond with an ITO layer to a pressure-sensitive adhesive composition containing a curing agent to improve adhesiveness to the ITO layer Thereby improving adhesion.

In addition, the general pressure-sensitive adhesive layer contains an acid in the functional group, and the pressure-sensitive adhesive layer containing the acid bonds with the ITO film. In this case, the Ag layer of the ITO layer and the lead wire is oxidized The problem arises. In order to solve the above problems, the composite film for a capacitive touch panel according to the present invention is characterized in that the functional group of the urethane copolymer resin contained in the pressure-sensitive adhesive layer is introduced into a hydroxy group and the curing agent is designed to an isocyanate system, Respectively.

In addition, in the touch panel industry, the image quality improvement film and the adhesive film are separately purchased and the laminating process is outsourced. Since the two films are purchased separately, there is a problem of defective management which occurs in the management problem and outsourcing , And low yield. Therefore, the present invention solves the above problems by integrating the two films.

Accordingly, the composite film for a capacitive touch panel according to the present invention is a film having a composite function capable of improving image quality, preventing oxidation, and preventing scattering.

1, which is a sectional view of a monolithic capacitive touch screen panel using a composite film for a capacitive touch panel according to the present invention, a printed layer 2 is formed on an edge portion on a glass for a touch panel, And the ITO layer 1 deposited thereon is deposited. After the ITO layer 1 is deposited, a pattern is formed through etching and the Ag layer 3, which is an outgoing line, The ITO layer and the Ag layer come to the bottom plate. Therefore, the two layers (ITO layer and Ag layer) are oxidized when exposed to air (oxygen), resulting in deterioration of electrical conductivity. In order to compensate for this, another protective film for protecting ITO and Ag layer is formed. It is an object of the present invention to provide a composite film for a capacitive touch panel, which is the protective film. The structure of such a composite film for capacitive touch panel is such that an adhesive layer 4 not containing an acid is formed on the plastic substrate 5 to prevent the oxidation of ITO and Ag layers, And two or more coating layers having different refractive indexes such as the high refractive index layer 6 and the low refractive index layer 7 in order to impart an antireflection function for improving the visibility.

Hereinafter, the components of the present invention will be described in detail.

1. High hardness layer manufacturing

1.1 High hardness layer of high refractive index

The refractive index of the high-hardness high-hardness layer, which is an essential thin film layer of the composite film for a capacitive touch panel according to the present invention, is 1.50 to 1.60, and more preferably 1.52 to 1.56. As a method for forming such a high hardness layer of high refractive index, a transparent thin film of an inorganic oxide formed by chemical vapor deposition (CVD) or physical vapor deposition (PVD), in particular, by vacuum vapor deposition or sputtering, which is one kind of physical vapor deposition , A thin film formed by all-wet coating is preferable.

The high hardness layer of the high refractive index is composed of an inorganic fine particle containing an oxide of at least one metal selected from Ti, Zr, In, Zn, Sn, Al and Sb, an anionic dispersant and a curable resin (Hereinafter also referred to as a "binder "), a coating composition containing a polymerization initiator and a solvent, drying the solvent, and curing the coating by one or both means of heating and irradiation of ionizing radiation . In the case of using a curable resin or an initiator, since the curable resin is hardened through polymerization reaction by heating and / or ionizing radiation after the coating, a high-refractive-index high-hardness layer excellent in scratch resistance and adhesiveness can be formed.

1.2 Inorganic fine particles

As the inorganic fine particles, oxides of metals (for example, Ti, Zr, In, Zn, Sn, Sb and Al) are preferable, and from the viewpoint of refractive index, zirconium oxide fine particles are most preferable. However, from the viewpoint of conductivity, it is preferable to use inorganic fine particles containing an oxide of at least one of Sb, In and Sn as a main component. The refractive index can be adjusted to a predetermined range by changing the amount of the inorganic fine particles. When zirconium oxide is used as a main component, the average particle diameter of the inorganic fine particles in the layer is preferably from 1 to 120 nm, more preferably from 1 to 60 nm, even more preferably from 2 to 40 nm. This range is preferable because it reduces haze and improves dispersion stability and adhesion to the upper layer by appropriate irregularities on the surface. The refractive index of the inorganic fine particles containing zirconium oxide as a main component used in the present invention is preferably 1.90 to 2.80, more preferably 2.10 to 2.80, and most preferably 2.20 to 2.80. The addition amount of the inorganic fine particles varies depending on the layer to which the inorganic fine particles are added, and the addition amount in the high refractive index layer is 40 to 85 mass%, preferably 50 to 75 mass%, and 60 to 70 mass% More preferable. The particle diameter of the inorganic fine particles can be measured by a light scattering method or an electron microscope photograph. The specific surface area of the inorganic fine particles is preferably from 10 to 400 m 2 / g, more preferably from 20 to 200 m 2 / g, and most preferably from 30 to 150 m 2 / g.

In order to stabilize the dispersion in the dispersion or the coating solution or to improve the affinity or the bonding property with the binder component, the inorganic fine particles are subjected to physical surface treatment such as plasma discharge treatment and corona discharge treatment or surface treatment with a surfactant, Chemical surface treatment may be performed. It is particularly preferable to use a coupling agent.

As the coupling agent, it is preferable to use an alkoxy metal compound (e.g., titanium coupling agent, silane coupling agent). In particular, treatment with a silane coupling agent having an acryloyl or methacryloyl group is effective. The chemical surface treatment agent, solvent, catalyst and dispersion stabilizer for the inorganic fine particles are described in paragraphs [0058] to [0083] of JP-A-2006-17870.

1.3 Curable resin

As the curable resin, a polymerizable compound is preferable, and as the polymerizable compound, an ionizing radiation-curable polyfunctional monomer or a polyfunctional oligomer is preferably used. The functional group in the compound is preferably a light-, electron-beam- or radiation-polymerizable functional group, and more preferably a photopolymerizable functional group.

Examples of the photopolymerizable functional group include unsaturated polymerizable functional groups such as (meth) acrylic group, vinyl group, styryl group and allyl group. Among them, a (meth) acrylic group is preferable.

Specific examples of the photopolymerizable polyfunctional monomer having a photopolymerizable functional group include (meth) acrylates of alkylene glycols such as neopentyl glycol acrylate, 1,6-hexanediol (meth) acrylate and propylene glycol di (meth) ) Acrylic acid diesters; (Meth) acrylic acid esters of polyoxyalkylene glycols such as triethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate and polypropylene glycol di Diesters; (Meth) acrylic acid diesters of polyhydric alcohols such as pentaerythritol di (meth) acrylate; (Meth) acrylate such as ethylene oxide or propylene oxide adducts such as 2,2-bis (4-acryloxypropyl) phenyl} propane and 2-2-bis {4- (acryloxypolypropoxy) Acrylic acid diesters.

Also, epoxy (meth) acrylates, urethane (meth) acrylates and polyester (meth) acrylates are preferably used as photopolymerizable polyfunctional monomers.

Among these, esters of polyhydric alcohol and (meth) acrylic acid are preferable, and polyfunctional monomers having three or more (meth) acrylic groups in one molecule are more preferable. Specific examples thereof include trimethylolpropane tri (meth) acrylate, trimethylol ethane tri (meth) acrylate, 1,2,4-cyclohexanetetra (meth) acrylate, pentaglycerol triacrylate, pentaerythritol (Meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol pentaacrylate, dipentaerythritol tetra (Meth) acrylate, tripentaerythritol triacrylate, and tripentaerythritol hexatriacrylate. Two or more of the multifunctional monomers may be used in combination. The amount of the curable resin to be used may be adjusted within a range that satisfies the refractive index of each layer described above.

1.4 Polymerization initiator

As the polymerization initiator, it is preferable to use a photopolymerization initiator. As the photopolymerization initiator, a photoradical polymerization initiator or a photocationic polymerization initiator is preferable, and a photoradical polymerization initiator is more preferable.

Examples of photo radical polymerization initiators include acetophenones, benzophenones, benzoyl benzoates of Michler,? -Amyloxime esters, tetramethylthiurammonosulfide and thioxanthones. Examples of commercially available photo radical polymerization initiators include Nippon Kayaku Co., Ltd. KAYACURE (e.g., DETX-S, BP-100, BDMK, CTX, BMS, 2-EAQ, ABQ, CPTX, EPD, ITX, QTX, BTC, MCA); Ciba Specialty Chemicals Corp. Irgacure (e.g., 651, 184, 127, 500, 907, 369, 1173, 2959, 4265, 4263) And Sartomer Company Inc. Esacure (KIP100F, KB1, EB3, BP, X33, KT046, KT37, KIP150, TZT) Particularly, photocleavage-type photo radical polymerization initiators are preferred. Photocatalytic photo radical polymerization initiators are available from Technical Information Institute Co., Ltd. (Published by Kazuhiro Takausu) (1991) on page 159 of the latest UV curing technology. Examples of commercially available photocatalytic photo radical polymerization initiators include Ciba Specialty Chemicals Corp. Irgacure (e.g., 651, 184, 127, 907). The amount of the photopolymerization initiator to be used is preferably 0.1 to 15 parts by mass, more preferably 1 to 10 parts by mass, per 100 parts by mass of the curable resin.

In addition to the photopolymerization initiator, a photosensitizer may be used. Specific examples of the photosensitizer include n-butylamine, triethylamine, tri-n-butylphosphine, Michler's ketone, and thioxanthone. Examples of commercially available photosensitizers include Nippon Kayaku Co., Ltd. KAYACURE (e.g., DMBI, EPA).

The photopolymerization reaction is preferably carried out by ultraviolet irradiation after coating the high hardness layer of high refractive index and drying.

In addition, the high-hardness layer of high refractive index may contain a surfactant, an antioxidant, a coupling agent, a thickener, a coloring agent, a colorant (for example, a pigment, Dyes, defoaming agents, leveling agents, flame retardants, ultraviolet absorbers, infrared absorbers, adhesion promoters, polymerization inhibitors, antioxidants, surface modifiers, conductive metal fine particles and the like.

1.5 Solvent

As the solvent, it is preferable to use a liquid having a boiling point of 60 to 170 占 폚. Specific examples thereof include water, alcohols such as methanol, ethanol, isopropanol, butanol, benzyl alcohol, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, esters such as methyl acetate (For example, methylene chloride, chloroform, carbon tetrachloride), ethyl acetate, propyl acetate, butyl acetate, methyl formate, ethyl formate, propyl formate, butyl formate), aliphatic hydrocarbons , Aromatic hydrocarbons such as benzene, toluene and xylene, amides such as dimethylformamide, dimethylacetamide and n-methylpyrrolidone, ethers such as diethyl ether, dioxane and tetrahydrofuran, Ether alcohols such as 1-methoxy-2-propanol. Of these, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and butanol are preferable. Particularly, as the dispersion medium, methyl ethyl ketone, methyl isobutyl ketone or cyclohexanone is preferable.

The solvent is preferably used such that the coating composition for a high refractive index layer has a solid content concentration of 2 to 30 mass%, more preferably 3 to 20 mass% of a solid content concentration.

1.6 How to form high hardness layer of high refractive index

The inorganic fine particles containing zirconium oxide as a main component used in the high hardness layer of the high refractive index are preferably used in the formation of a high hardness layer of high refractive index in a dispersion state. The inorganic fine particles may be dispersed using a dispersing machine. Examples of the dispersing machine include a sand grinder mill (for example, a bead mill with a pin), a high-speed impeller mill, a pebble mill, a roller mill, an attritor and a colloid mill. Among these, a sand grinder mill and a high-speed impeller mill are preferable. A preliminary dispersion process may be performed. Examples of the dispersing machine used for the preliminary dispersion treatment include a ball mill, a three-roll mill, a kneader and an extruder.

It is preferable that the inorganic fine particles are dispersed so as to have a particle size as small as possible in the dispersion medium. The mass average particle diameter is preferably 10 to 120 nm, more preferably 20 to 100 nm, even more preferably 30 to 90 nm, still more preferably 30 to 80 nm. By dispersing the inorganic fine particles in a small particle size of 200 nm or less, a high-refractive-index high-hardness layer can be formed without impairing transparency.

The high-hardness high-hardness layer used in the present invention is formed as follows. A curing resin (for example, the above ionizing radiation-curable multifunctional monomer or polyfunctional oligomer) as a binder precursor necessary for forming a matrix, a photopolymerization initiator and the like are added to the dispersion obtained by dispersing the inorganic fine particles in the dispersion medium as described above , A high refractive index layer or a medium refractive index layer is prepared, and the obtained coating composition for forming a high refractive index layer or the medium refractive index layer is coated on a transparent support and cured by crosslinking reaction or polymerization reaction of the curable resin. It is preferable that the binder of the layer is crosslinked or polymerized with the dispersing agent at the same time as or after the coating of the high-hardness layer of high refractive index.

The binder of the high refractive index layer or the medium refractive index layer thus produced can be obtained by, for example, taking an anionic group of the dispersing agent in the binder as a result of the crosslinking reaction or polymerization reaction between the above-mentioned preferable dispersant and the ionizing radiation-curable polyfunctional monomer or polyfunctional oligomer It becomes a losing form. The anionic group taken in the binder of the high refractive index layer or the medium refractive index layer has a function of maintaining the dispersed state of the inorganic fine particles and the crosslinking or polymerization structure gives the binder a film-forming ability. As a result, the high refractive index The coating layer is improved in physical strength, chemical resistance and weather resistance.

At the time of forming a high-hardness layer at high refractive index, the crosslinking or polymerization reaction of the curable resin is preferably carried out in an atmosphere having an oxygen concentration of 10 vol% or less. By forming a high-refractivity high-hardness layer in an atmosphere having an oxygen concentration of 10 vol% or less, the high-refractivity high-hardness layer can improve physical strength, chemical resistance, weather resistance, and adhesion between the high refractive index layer and the layer adjacent to the high refractive index layer.

The layer formation through the crosslinking reaction or polymerization reaction of the curable resin is preferably performed in an atmosphere having an oxygen concentration of 6 vol% or less, more preferably in an atmosphere having an oxygen concentration of 4 vol% or less, and more preferably in an atmosphere having an oxygen concentration of 2 vol% Most preferably, it is carried out in an atmosphere having an oxygen concentration of 1% by volume or less.

The thickness of the high-hardness layer of high refractive index is preferably 0.1 to 20 탆, more preferably 2 to 8 탆. Specifically, for example, the main composition is determined by selecting the kind of the fine particles and the kind of the resin so that the film thickness and the refractive index of the high-hardness high-hardness layer can be satisfied, and the blending ratio thereof is determined.

2. Production of low refractive index layer

2.1 Low Refractive Index Layer

The low refractive index layer of the composite film for a capacitive touch panel according to the present invention preferably has a refractive index of 1.31 to 1.40, more preferably 1.38 or less. This range is preferable because the film strength can be maintained while reducing the reflectance. Similarly to the above, a method of forming a low refractive index layer may be a method of using a transparent thin film of an inorganic oxide formed by chemical vapor deposition (CVD) or physical vapor deposition (PVD), in particular, by vacuum vapor deposition or sputtering, Wet coating method using a coating composition for forming a low refractive index layer described later is preferable. The low refractive index layer preferably contains inorganic fine particles. Among the inorganic fine particles, at least one kind of inorganic fine particles are preferably hollow particles, and hollow particles containing silica as a main component (hereinafter also referred to as "hollow silica particles" Is more preferable. The thickness of the refraction layer is preferably 90 to 130 nm, more preferably 100 to 120 nm. The haze of the low refractive index layer is preferably 3% or less, more preferably 2% or less, and most preferably 1% or less.

In addition, in the pencil hardness test at a load of 500 g, the strength of the antireflection film having the layers up to the low-resistance layer is preferably H or higher, more preferably 2H or higher, and most preferably 3H or higher.

In addition, in the case of the antireflection film for PDP, it is preferable that the contact angle of the surface of the antireflection film with respect to water is 95 to 120 degrees in order to improve the fingerprint prevention performance. In the case of the antireflection film for a touch panel, It is preferable that the contact angle of the surface with respect to water is 85 DEG or less because the edges of the LCD surface and the double-sided tape are laminated so that a sufficient adhesive force with the AR surface is secured.

2.2 Inorganic Fine Particles

The inorganic fine particles that can be used in the low refractive index layer are preferably hollow particles. The refractive index of the hollow particles is preferably 1.40 or less, more preferably 1.28 to 1.38, and most preferably 1.32 to 1.36. The hollow particles are preferably hollow silica particles, and the inorganic fine particles are described below with reference to hollow silica particles. The refractive index used here represents the refractive index of the whole particles and does not represent the refractive index of silica alone as the outer shell forming the hollow silica particles. Assuming that the radius of the cavity inside the particle is a and the radius of the outer shell of the particle is b, the porosity x represented by the following formula (1) is preferably 10 to 60%, and preferably 20 to 60% , And most preferably 30 to 60%.

Equation (1): x = (4πa 3/3) (4πb 3/3) X 100

If the hollow silica particles are intended to have a lower refractive index and a higher porosity, the thickness of the outer shell is thinned and the strength as a particle is lowered. Therefore, from the viewpoint of scratch resistance, particles having a refractive index within the above-mentioned range are preferable.

Here, the refractive index of the hollow silica particles can be measured by an Abbe refractometer (manufactured by ATAGO K.K.). Methods for producing hollow silica are described, for example, in JP-A-2001-233611 and JP-A-2002-79616. Commercially available hollow silica particles may also be used.

The coating amount of the hollow silica particles is preferably from 1 to 100 mg / m 2, more preferably from 5 to 80 mg / m 2, still more preferably from 10 to 60 mg / m 2. Within this range, a favorable effect of reducing the refractive index or improving the scratch resistance can be obtained, the occurrence of fine irregularities on the surface of the low refractive index layer can be prevented, and the appearance (for example, a black appearance) It can be kept good.

The average particle diameter of the hollow silica particles is preferably 30 to 150%, more preferably 35 to 80%, and even more preferably 40 to 60% with respect to the thickness of the low refractive index layer. That is, if the thickness of the low refractive index layer is 100 nm, the particle diameter of the hollow silica particles is preferably 30 to 150 nm, more preferably 35 to 80 nm, still more preferably 40 to 60 nm. If the particle diameter is within this range, the ratio of the cavity can be satisfactorily maintained, the refractive index can be sufficiently reduced, the occurrence of fine irregularities on the surface of the low refractive index layer can be prevented, and the appearance (for example, ) And the integral reflectance can be kept good. The fine silica particles may be crystalline or amorphous, and monodisperse particles are preferred. The shape is most preferably spherical, but it may be irregular. The average particle diameter of the hollow silica particles can be determined from electron micrographs.

In the present invention, silica particles having no cavities can be used in combination with the hollow silica particles. The particle size of the silica without cavities is preferably 5 to 150 nm, more preferably 10 to 80 nm, and most preferably 15 to 60 nm.

Further, at least one kind of silica fine particles (also referred to as "small particle size silica fine particles") having an average particle diameter of less than 25% of the thickness of the low refractive index layer is prepared by mixing silica fine particles having the above- "). ≪ / RTI > The small particle size silica fine particles may be present in a gap between large particle size silica fine particles, and thus can contribute as a retaining agent for large particle size silica fine particles. The average particle diameter of the small particle size silica fine particles is preferably from 1 to 20 nm, more preferably from 5 to 15 nm, even more preferably from 10 to 15 nm. The use of such fine silica particles is preferable from the viewpoints of the cost of raw materials and the effect of the preservative agent. In order to stabilize the dispersion in the dispersion or coating solution or to improve the affinity or binding property with the binder component, the hollow particles may be subjected to physical surface treatment such as plasma discharge treatment and corona discharge treatment, or surface treatment with a surfactant, Chemical surface treatment may be performed. The use of a coupling agent is particularly preferred. As the coupling agent, it is preferable to use an alkoxy metal compound (for example, a titanium coupling agent or a silane coupling agent). Among them, the treatment with a silane coupling agent having an acryloyl or methacryloyl group is effective. The chemical surface treatment agent, solvent, catalyst and dispersion stabilizer for hollow particles are described in paragraphs [0058] to [0083] of JP-A-2006-17870.

The low refractive index layer may also be formed by applying a coating composition containing a film-forming solute and one or more solvents, drying the solvent, and curing the coating by either or both means of heating and irradiation of ionizing radiation . As the solute, a composition containing a heat-curable or ionizing radiation-curable fluorine-containing curable resin, a hydrolyzate of an organosilyl compound, or a partial condensate thereof is preferable. Further, it is preferable to use a composition containing a fluorine-containing curable resin as the low refractive index layer, and more preferably an embodiment in which a hydrolyzate of an organosilyl compound or a partial condensate thereof is supplementarily used. The amount of the hydrolyzate of the organosilyl compound or the partial condensate thereof to be used as an auxiliary is 10 to 40 mass% with respect to the fluorine-containing curable resin.

2.3 Coating composition for forming a low refractive index layer

Usually, the coating composition for forming a low refractive index layer takes a liquid form, dissolving the above-mentioned inorganic fine particles and the fluorine-containing curable resin preferably contained in an appropriate solvent, dissolving various additives and a radical polymerization initiator . Here, the concentration of the solid content may be appropriately selected depending on the application, but is generally from 0.01 to 60% by mass, more preferably from 0.5 to 50% by mass, still more preferably from 1 to 20% by mass.

The radical polymerization initiator may be either a type generating a radical under heat or a type generating a radical under an optical action. For compounds that initiate radical polymerization under the action of heat, organic or inorganic peroxides, organic azo or diazo compounds and the like may be used.

More specifically, examples of organic peroxides include benzoyl peroxide, halogen benzoyl peroxide, lauroyl peroxide, acetyl peroxide, dibutyl peroxide, cumene hydroperoxide and butyl hydroperoxide; Examples of inorganic peroxides include hydrogen peroxide, ammonium persulfate, and potassium persulfate; Examples of azo compounds include 2-azo-bis-isobutyronitrile, 2-azo-bis-propionitrile and 2-azo-bis-cyclohexanedinitrile; Examples of diazo compounds include diazoaminobenzene and p-nitrobenzene diazonium. When a compound that initiates radical polymerization under the action of light is used, the film is cured by irradiation with ionizing radiation. Examples of such photo radical polymerization initiators include acetophenones, benzoins, benzophenones, phosphinoxides, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-dialkyldione compounds Logistics, disulfide compounds, fluoroamine compounds and aromatic sulfoniums. Examples of the acetophenones include 2,2-diethoxyacetophenone, p-dimethylacetophenone, 1-hydroxydimethylphenylketone, 1-hydroxycyclohexylphenylketone, 2-methyl- 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone. Examples of the benzoin include benzoin benzene sulfonic acid ester, benzoin toluene sulfonic acid ester, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether. Examples of benzophenones include benzophenone, 2,4-dichlorobenzophenone, 4,4-dichlorobenzophenone and p-chlorobenzophenone. Examples of the phosphine oxides include 2,4,6-trimethylbenzoyldiphenylphosphine oxide. In addition, a sensitizing dye may be preferably used in combination with such a photoradical polymerization initiator.

The amount of the compound which initiates radical polymerization under the action of heat or light may be sufficient to initiate polymerization of the carbon-carbon double bond. The amount of the compound added is preferably 0.1 to 15% by mass relative to the total solid content of the composition for forming a low refractive index layer, , More preferably from 0.5 to 10 mass%, still more preferably from 2 to 5 mass%.

2.4 Solvent

The solvent contained in the coating composition for a low refractive index layer is not particularly limited as long as the curable resin can be uniformly dissolved or dispersed without causing precipitation, and two or more solvents may be used in combination. Preferred examples thereof include ketones (e.g., acetone, methyl ethyl ketone, methyl isobutyl ketone), esters (e.g., ethyl acetate, butyl acetate), ethers (e.g., tetrahydrofuran, 1,4 Dioxane), alcohols (e.g., methanol, ethanol, isopropyl alcohol, butanol, ethylene glycol), aromatic hydrocarbons (e.g., toluene, xylene), and water.

2.5 Other compounds appropriately contained in the coating composition for forming a low refractive index layer

Known silicone-based or fluorine-based anti-fingerprinting agents, lubricants, and the like may be appropriately added to impart properties such as a fingerprint-preventing property, a water resistance, a chemical resistance and a sliding property. When such an additive is added, the amount of the additive to be added is preferably from 0 to 20 mass%, more preferably from 0 to 10 mass%, still more preferably from 0 to 5 mass%, based on the total solid content of the low refractive index layer.

The low refractive index layer may contain an inorganic filler, a silane coupling agent, a lubricant, a surfactant, and the like. In particular, inorganic fine particles, a silane coupling agent and a lubricant are preferably contained.

As examples of the silane coupling agent, a silane coupling agent containing a hydroxyl group, a mercapto group, a carboxyl group, an epoxy group, an alkyl group, an alkoxysilyl group, an acyloxy group or an acylamino group is preferable, and an epoxy group, a polymerizable acyloxy group (E.g., (meth) acryloyl) or a polymerizable acylamino group (e.g., acrylamino, methacryloamino). The lubricant is preferably a silicone compound such as dimethylsilicone or a fluorine-containing compound into which a polysiloxane moiety is introduced.

2.6 Organosilyl compounds

The organosilyl compound becomes a hydrolyzate and / or a partial condensate by hydrolysis and condensation in a coating composition for formation of a low refractive index layer, and not only functions as a binder in the composition, but also allows flexibility of film coating and improves alkali resistance. In the present invention, the organosilyl compound preferably used in the coating composition for forming a low refractive index layer includes a compound represented by the following formula (3).

(3)

R ¹¹ mSi (X ¹¹ ) n

Wherein R ¹¹ represents an alkyl group, an alkenyl group or an aryl group, R ¹² represents an alkyl group, m + n is 4, and m and n each independently represents an integer of 0 or 1, and X ¹¹ represents -OH, halogen atom, -OR ¹² group or -OCOR ¹² group, R ¹¹ is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms (e.g., methyl, ethyl, propyl, i-propyl, butyl, hexyl, octyl) , A substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms (e.g., vinyl, allyl or 2-butene-1-yl) or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms Phenyl, naphthyl), and R ¹² represents a group having the same meaning as the alkyl group represented by R ¹¹ . When the group represented by R ¹¹ or R ¹² has a substituent, preferred examples of the substituent include halogen (for example, fluorine, chlorine, bromine), hydroxyl group, mercapto group, carboxyl group, epoxy group, (E.g., methyl, ethyl, i-propyl, propyl, tert-butyl), an aryl group (for example, phenyl or naphthyl), an aromatic heterocyclic group (for example, furyl, pyrazolyl, pyridyl) For example methoxy, ethoxy, i-propoxy, hexyloxy), aryloxy groups (for example phenoxy), alkylthio groups (for example methylthio, ethylthio) (For example, phenylthio), an alkenyl group (e.g., vinyl, allyl), an acyloxy group (for example, acetoxy, acryloyloxy, methacryloyloxy), an alkoxycarbonyl group Methoxycarbonyl, ethoxycarbonyl), an aryloxycarbonyl group (for example, phenoxycarbonyl), a carbamoyl group (for example, (For example, acetylamino, benzoylamino, acrylamino, methacryloyloxy, and the like), such as methyl, ethyl, n-propyl, ).

The compound of formula (3) forms a matrix by the so-called sol-gel method including hydrolysis and co-condensation. The compound of formula (3) is represented by the following four equations.

[Formula 3a] Si (X ¹¹⁾ ₄

???????? R ¹¹ Si (X ¹¹ ) ₃ ?????

???????? R ¹¹ ₂ Si (X ¹¹ ) ₂ ?????

Formula 3d] R ¹¹ ₃ SiX ¹¹

The components of formula (3a) are described in detail below. Specific examples of the compound represented by the formula (3a) include tetramethoxysilane, tetraethoxysilane, tetra-i-propoxysilane, tetra-n-propoxysilane, tetra-n-butoxysilane, tetra- Ethoxy silane and tetra-tert-butoxy silane. In particular, tetramethoxysilane and tetraethoxysilane are preferred.

The components of formula (3b) are described below. In the component of formula 3b, R ¹¹ represents a group having the same meaning as that of Formula 3 R ^11, and examples thereof include methyl, ethyl, n- propyl, and i- propyl groups such as alkyl group, γ- chloropropyl group, a vinyl group, CF ₃ CH ₂ CH ₂ CH ₂ -, C ₂ F ₅ CH ₂ CH ₂ CH ₂ -, C ₃ F ₇ CH ₂ CH ₂ CH ₂ -, C ₂ F ₅ CH ₂ CH ₂ -, CF ₃ OCH ₂ CH ₂ CH ₂ -, C ₂ F ₅ OCH ₂ CH ₂ CH ₂ -, C ₃ F ₇ OCH ₂ CH ₂ CH ₂ -, (CF ₃ ) ₂ CHOCH ₂ CH ₂ CH ₂ -, C ₄ F ₉ CH ₂ OCH ₂ CH ₂ CH ₂ -, 3- (perfluoro-cyclohexyloxy) propyl _{group, H (CF 2) 4 CH} 2 OCH 2 CH 2 CH 2 -, H (CF 2) 4 CH 2 CH 2 CH 2 -, 3 -Glycidoxypropyl group, 3-acryloxypropyl group, 3-methacryloxypropyl group, 3-mercaptopropyl group, phenyl group and 3,4-epoxycyclohexylethyl group. X ¹¹ represents -OH, a halogen atom, -OR ¹² group or -OCOR ¹² group. R ¹² represents a group having the same meaning as R ¹² in formula (2), preferably an acyloxy group having an alkoxy group or 1 to 4 carbon atoms, a has a range of 1 to 5 carbon atoms. Examples thereof include a chlorine atom, a methoxy group , Ethoxy group, n-propyloxy group, i-propyloxy group, n-butyloxy group, s-butyloxy group, tert-butyloxy group and acetyloxy group. Specific examples of the component of Formula 3b include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, i -Propyltrimethoxysilane, i-propyltriethoxysilane, chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltri Methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxysilane, 3- methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3,4-epoxycyclohexylethyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, Silane, 3,4-epoxycyclohexylethyltriethoxysilane, _{CF 3 CH 2 CH 2 CH 2} Si (OCH 3) 3 -, C 2 H 5 CH 2 CH 2 CH 2 Si (OCH 3) 3 -, C 2 F 5 CH 2 CH 2 Si (OCH 3) 3 -, _{C 3 F 7 CH 2 CH 2} CH 2 Si (OCH 3) 3 -, C 2 F 5 OCH 2 CH 2 CH 2 Si (OCH 3) 3 -, C 3 F 7 OCH 2 CH 2 CH 2 Si (OC 2 _{H 5) 3 -, (CF} 3) 2 CHOCH 2 CH 2 CH 2 Si (OCH 3) 3 -, C 4 F 9 CH 2 OCH 2 CH 2 CH 2 Si (OCH 3) 3 -, H (CF 2) ₄ CH ₂ OCH ₂ CH ₂ CH ₂ Si (OCH ₃ ) ₃ -, and 3- (perfluorocyclohexyloxy) propylsilane.

Of these, an organosilyl compound having a fluorine atom is preferable. When R is an organic silane compound having no fluorine atom, methyltrimethoxysilane or methyltriethoxysilane is preferably used. One of these organosilyl compounds may be used alone, or two or more of them may be used in combination.

The components of formula (3c) are described below. The component of Formula 3c is an organosilyl compound represented by the formula R ¹¹ ₂ Si (X ¹¹ ) ₂ {wherein R ¹¹ and X ¹¹ are the same as R ¹¹ and X ¹¹ defined in the organosilyl compound used as the component of Formula 3b . Here, a plurality of R < ¹¹ > s may not be the same group. Specific examples of the organosilyl compound include dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, di-n-propyldimethoxysilane, di-n-propyldiethoxysilane, di (CF ₃ CH ₂ CH ₂ ) ₂ Si (OCH ₃ ) ₂ , (CF ₃ CH ₂ ) ₂ , and the like. _{CH 2 CH 2) 2 Si (} OCH 3) 2, (C 3 F 7 OCH 2 CH 2 CH 2) 2 Si (OCH 3) 2, [H (CF 2) 6 CH 2 OCH 2 CH 2 CH 2] 2 include Si (OCH _{3) 2} and _{(C 2 F 5 OCH 2 CH} 2) 2 Si (OCH 3) 2. An organic silyl compound having a fluorine atom is preferable. When R11 is an organosilyl compound having no fluorine atom, dimethyldimethoxysilane or dimethyldiethoxysilane is preferable. One of the organosilyl compounds represented by the formula (3c) may be used alone, or two or more of them may be used in combination.

The components of the formula (3d) are explained below. The component of the formula (3d) is an organosilyl compound represented by the formula R ¹¹ ₃ SiX ¹¹ , wherein R ¹¹ and X ¹¹ have the same meanings as R ¹¹ and X ¹¹ defined in the organosilyl compound used as the component of the formula (3b) }. Here, a plurality of R < ¹¹ > s may not be the same. Specific examples of the organosilyl compound include trimethylmethoxysilane, trimethylethoxysilane, triethylmethoxysilane, triethylethoxysilane, tri-n-propylmethoxysilane, tri-n-propylethoxysilane, tri i-propylmethoxysilane, tri-i-propylethoxysilane, triphenylmethoxysilane, and triphenylethoxysilane.

In the present invention, each of the components represented by the general formulas (3a) to (3d) may be used singly or as a mixture. In this case, the mixing ratio is preferably 0 to 100 parts by mass relative to 100 parts by mass of the component Preferably 1 to 60 parts by mass, more preferably 1 to 40 parts by mass; The component (3c) is preferably 0 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, and even more preferably 0.5 to 3 parts by mass with respect to 100 parts by mass of the component (3a). The amount of the component (III) is preferably 0 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, and even more preferably 0.5 to 3 parts by mass based on 100 parts by mass of the component (III). Of the components (3a) to (3d), the proportion of the component (3a) is preferably 30 mass% or more in 100 mass% of the total organosilyl compound. When the proportion of the component (3a) is more than 30% by mass, problems such as decrease in adhesiveness or curability of the film coating to be obtained do not occur, which is preferable. The compound described in paragraphs [0039] and [0052] to [0067] of JP-A-2006-30740 may be preferably added, or the coating composition for forming a low refractive index layer described herein It may be produced preferably.

2.7 Formation of low refractive index layer

The low refractive index layer is formed by applying a coating composition in which hollow particles, a fluorine-containing curable resin, an organosilyl compound, and optionally other optional components are dissolved or dispersed therein, and simultaneously with coating or after coating and drying, (For example, light irradiation or electron beam irradiation), or by curing the coating through crosslinking or polymerization reaction under heating.

In particular, when the low refractive index layer is formed through crosslinking or polymerization of an ionizing radiation-curable compound, the crosslinking or polymerization reaction is preferably carried out in an atmosphere having an oxygen concentration of 10 vol% or less. By forming a low refractive index layer in an atmosphere having an oxygen concentration of 10 vol% or less, an outermost layer excellent in physical strength and chemical resistance can be obtained. The oxygen concentration is preferably 6 vol% or less, more preferably 4 vol% or less, still more preferably 2 vol% or less, most preferably 1 vol% or less. As a means for reducing the oxygen concentration to 10 vol% or less, it is preferable to replace the atmosphere (nitrogen concentration: about 79 vol%, oxygen concentration: about 21 vol%) with another gas and substitution with nitrogen (nitrogen purge) Is more preferable.

3. Manufacturing method of urethane-based pressure sensitive adhesive

The coated substrate to which the pressure-sensitive adhesive composition according to the present invention is applied is preferably any one of a polyethylene terephthalate (PET) film, a polypropylene (PP) film, and a polyethylene (PE) film.

3.1 Adhesive

The pressure-sensitive adhesive of the present invention contains the urethane resin obtained by the above-described process for producing a urethane resin. Since the urethane resin obtained by the above-mentioned production method has a self-adhesive property, it can be used as a pressure-sensitive adhesive directly. However, by further reacting the secondary hydroxyl group or the tertiary hydroxyl group remaining in the urethane resin with the polyisocyanate compound as the crosslinking agent, a pressure-sensitive adhesive excellent in re-releasability can be obtained. That is, the present invention is a pressure-sensitive adhesive formed by reacting the urethane resin and the polyisocyanate compound.

3.2 Hardener

As the polyisocyanate compounds usable as the curing agent, polyfunctional polyisocyanates such as the above polyisocyanate compounds and their trimethylolpropane adduct type modified products, buret type modified products or isocyanurate type modified products are used. Among them, it is preferable to be a modification having an average number of functional groups of 2 or more. For example, Dyuranate P301-75E (trimethylol propane adduct type HDI, content of isocyanate group: 12.9% by mass, solid content: 75% by mass, manufactured by Asahi Kasei Corporation), Colonate L (manufactured by Nippon Polyurethane Industry, trimethylol propane Water type TDI, isocyanate group content: 13.5% by mass, solids content: 75% by mass). As the polyisocyanate compound, 10 to 30% by mass of an isocyanate group content (excluding a solvent in the case of a solution) is preferably reacted within a range of 20 parts by mass or less based on 100 parts by mass of the urethane resin. And more preferably from 0.01 to 10 parts by mass because of better releasability. On the other hand, when the polyisocyanate compound is not used, the cohesive force is lowered and the cohesion is easily broken. When the amount is more than 20 parts by mass, the cohesion is too strong and the cohesion tends to decrease. Since the strength of the pressure-sensitive adhesive can be adjusted by adjusting the amount of the polyisocyanate compound used, a pressure-sensitive adhesive having a good balance between the pressure-sensitive adhesive property and the strength can be easily obtained. It is preferable that the polyisocyanate compound is added to the urethane resin and reacted with the adherend immediately before coating the pressure-sensitive adhesive. When a crosslinking agent and a secondary hydroxyl group remaining in the urethane resin are reacted, an urethane formation catalyst can be used. As the urethanation catalyst, an urethane formation catalyst used in the prepolymer formation reaction may be used.

By reacting the polyisocyanate compound in the present invention, the urethane resin crosslinked through the secondary hydroxyl group or the tertiary hydroxyl group remaining in the urethane resin is excellent in the balance between the adhesive property and the strength, and is excellent in re-peeling property while maintaining the adhesive property . In addition, since it is based on the urethane resin described above, it is inexpensive. In addition, since it does not contain an acrylic compound, it is considered that migration to an adherend and skin irritation are low. Further, since the crosslinked urethane resin has a large molecular weight and is hardly hardened at a low temperature, it is considered that the temperature dependency of the adhesive force is low. Further, it is considered that the low molecular weight compound does not migrate to the surface like the rubber adhesive.

3.3 Silane coupling agent

The silane coupling agent is used for further enhancing the adhesive force upon bonding with the ITO layer or the substrate, and a known silane coupling agent can be used. As the silane coupling agent preferably containing an epoxy group, for example, 3-glycidoxypropyltrimethoxysilane can be used. The epoxy group of the silane coupling agent binds to the crosslinkable functional group of the acrylic copolymer and the alkoxysilane part strongly bonds the ITO layer of the ITO film to improve the adhesive stability to further improve the heat resistance and humidity resistance, It is helpful to improve adhesion durability.

The silane coupling agent is preferably contained in an amount of 0.01 to 1 part by weight based on 100 parts by weight of the urethane-based copolymer (based on the solid content). When the content is less than 0.01 part by weight, the adhesion of the ITO film to the ITO layer may be weak. When the content is more than 1 part by weight, the workability of the ITO film is poor.

Hereinafter, the structure and effect of the present invention will be described in more detail with reference to examples and comparative examples. However, this embodiment is intended to explain the present invention more specifically, and the scope of the present invention is not limited to these embodiments.

[Example 1]

First, 8 parts by weight of Antimony Zinc Oxide (AZO), 3 parts by weight of an acrylic monomer, 0.5 parts by weight of a photoinitiator (hereinafter, referred to as " And 88.5 parts by weight of PGME as a solvent were coated on a 80 μm thick polyester substrate (PET film, refractive index: 1.65, manufactured by Toray Industries, Ltd.) using a # 2 Meyer bar as a # 2 high refractive index coating composition for high- Dried at 100 ° C for 2 minutes, and cured by ultraviolet irradiation to form a high-refractive-index high-hardness layer having an optical thickness of 100 nm and a refractive index of 1.67.

Next, 10 parts by weight of hollow silica particles as inorganic fine particles, 4 parts by weight of an acrylic monomer resin, 0.5 parts by weight of a photoinitiator, and 85.5 parts by weight of PGME as a solvent were added to the high refractive index layer using # 2 Meyer bar Dried, and cured by irradiation with ultraviolet rays to form a low refractive index layer having a thickness of 80 nm and a refractive index of 1.31.

Finally, 100 parts by weight of a pressure-sensitive adhesive composition (urethane copolymer, weight average molecular weight: 1,230,000, molecular weight distribution: 4.3, glass transition temperature: -47 DEG C, gel fraction: 85%) containing 1.0 wt% A pressure-sensitive adhesive composition (based on solid content) comprising 1.3 parts by weight of a curing agent and 0.05 parts by weight of a silane coupling agent was coated on the release film and then a pressure sensitive adhesive of 25 μm in dry thickness was applied on the opposite side of the PET base film on which the high- And then aged at room temperature for 7 days to prepare a pressure sensitive adhesive layer to produce a composite film for a capacitive touch panel.

[Example 2]

A composite film for a capacitive touch panel was produced in the same manner as in Example 1 except that a low refractive index layer having a refractive index of 1.33 was formed.

[Example 3]

A composite film for a capacitive touch panel was produced in the same manner as in Example 1 except that a low refractive index layer having a refractive index of 1.35 was formed.

[Example 4]

A composite film for a capacitive touch panel was produced in the same manner as in Example 1 except that a low refractive index layer having a refractive index of 1.37 was formed.

[Example 5]

A composite film for a capacitive touch panel was produced in the same manner as in Example 1 except that a low refractive index layer having a refractive index of 1.39 was formed.

[Comparative Example 1]

A composite film for a capacitive touch panel was produced in the same manner as in Example 1 except that a low refractive index layer having a refractive index of 1.41 was formed.

[Comparative Example 2]

A composite film for a capacitive touch panel was produced in the same manner as in Example 1 except that a low refractive index layer having a refractive index of 1.43 was formed.

[Comparative Example 3]

A composite film for a capacitive touch panel was produced in the same manner as in Example 1 except that a low refractive index layer having a refractive index of 1.45 was formed.

[Comparative Example 4]

A composite film for a capacitive touch panel was produced in the same manner as in Example 1 except that a low refractive index layer having a refractive index of 1.47 was formed.

[Comparative Example 5]

A composite film for a capacitive touch panel was produced in the same manner as in Example 1 except that a low refractive index layer having a refractive index of 1.49 was formed.

Using the composite film for capacitive touch panel according to Examples 1 to 5 and Comparative Examples 1 to 5, surface reflectance was measured by the following Experimental Example 1, and the results are shown in Table 1 below.

[Experimental Example 1]

The surface reflectance was measured with a UV spectrophometer (Shimazu UV-PC3600) equipped with an adapter at an incident angle (= reflection angle) of 5 ° in a wavelength range of 380 to 780 nm. A black matte tape The surface reflectance was measured after backside treatment with black or black matte paint. Thereafter, the average mirror reflectance was calculated in the range of 480 to 680 nm to evaluate the antireflection performance.

High-hardness layer
The refractive index (n1) The refractive index of the low refractive index layer
Refractive index (n2) At 480 to 680 nm
Average mirror reflectance (%) Example 1 1.67 1.31 0.24 Example 2 1.67 1.33 0.46 Example 3 1.67 1.35 0.68 Example 4 1.67 1.37 0.94 Example 5 1.67 1.39 1.35 Comparative Example 1 1.67 1.41 1.64 Comparative Example 2 1.67 1.43 1.88 Comparative Example 3 1.67 1.45 2.01 Comparative Example 4 1.67 1.47 2.35 Comparative Example 5 1.67 1.49 2.55

[Example 6]

The high refractive index layer, the low refractive index layer and the PET base film described in Example 1 were constructed in the same manner. The pressure-sensitive adhesive composition (urethane copolymer, weight average molecular weight: 1,230,000, molecular weight distribution: 4.3, 1.3 parts by weight of an isocyanate-based curing agent and 0.05 part by weight of a silane coupling agent (3-glycidoxypropyltrimethoxysilane) were added to 100 parts by weight of a releasing film Coated on the opposite side of the PET base film on which the high refractive index layer was formed was transferred and matched with a pressure sensitive adhesive having a dry thickness of 20 占 퐉 to prepare a composite film for capacitive touch panel.

[Example 7]

A composite film for a capacitive touch panel was prepared in the same manner as in Example 6 except that a pressure sensitive adhesive composition containing 1.0 wt% of a hydroxyl group was used.

[Example 8]

A composite film for a capacitive touch panel was prepared in the same manner as in Example 6 except that a pressure sensitive adhesive composition containing 2.5 wt% of a hydroxyl group was used.

[Example 9]

A composite film for a capacitive touch panel was prepared in the same manner as in Example 6 except that a pressure sensitive adhesive composition containing 5.0 wt% of a hydroxyl group was used.

[Example 10]

A composite film for a capacitive touch panel was prepared in the same manner as in Example 6 except that a pressure sensitive adhesive composition containing 10.0 wt% of a hydroxyl group was used.

[Comparative Example 6]

The high refractive index layer, the low refractive index layer and the PET base film described in Example 1 were constructed in the same manner. The pressure-sensitive adhesive composition (urethane copolymer, weight average molecular weight: 1,230,000, molecular weight distribution: 4.3, glass transition 1.3 parts by weight of an epoxy-based curing agent and 0.05 part by weight of a silane coupling agent (3-glycidoxypropyltrimethoxysilane) were added to 100 parts by weight of a releasing film (temperature: -47 DEG C, gel fraction: 85% A pressure sensitive adhesive having a dry thickness of 20 占 퐉 was transferred to an antireflection film, followed by aging and aging to produce a composite film for a capacitive touch panel.

[Comparative Example 7]

A composite film for capacitive touch panel was produced in the same manner as in Comparative Example 6 except that a pressure sensitive adhesive composition containing 1.0 wt% of a carboxyl group was used.

[Comparative Example 8]

A composite film for a capacitive touch panel was produced in the same manner as in Comparative Example 6 except that a pressure sensitive adhesive composition containing 2.5 wt% of a carboxyl group was used.

[Comparative Example 9]

A composite film for capacitive touch panel was produced in the same manner as in Comparative Example 6 except that a pressure sensitive adhesive composition containing 5.0 wt% of carboxyl groups was used.

[Comparative Example 10]

A composite film for a capacitive touch panel was produced in the same manner as in Comparative Example 6 except that a pressure sensitive adhesive composition containing 10.0 wt% of a carboxyl group was used.

Using the composite film for capacitive touch panel according to Examples 6 to 10 and Comparative Examples 6 to 10, the rate of change of current was measured through the following Experimental Example 2, and the results are shown in Table 2 below.

[Experimental Example 2]

After laminating in the manner shown in FIG. 2, the amount of current was measured by measuring the amount of current using a current measuring device (MCP-T600) after 85 ° C * 95% * 500 hr reliability.

The pressure-
Type of functional group The pressure-
Functional content (wt%) Current change rate (%)
[85 ° C * 95% * 500 hr] Example 6 The hydroxyl group (-OH) 0.5 0.01 Example 7 The hydroxyl group (-OH) 1.0 0.01 Example 8 The hydroxyl group (-OH) 2.5 0.01 Example 9 The hydroxyl group (-OH) 5 0.01 Example 10 The hydroxyl group (-OH) 10 0.01 Comparative Example 6 The carboxyl group (-COOH) 0.5 61 Comparative Example 7 The carboxyl group (-COOH) 1.0 69 Comparative Example 8 The carboxyl group (-COOH) 2.5 87 Comparative Example 9 The carboxyl group (-COOH) 5 92 Comparative Example 10 The carboxyl group (-COOH) 10 114

[Example 11]

The high refractive index layer, the low refractive index layer and the PET base film described in Example 1 were constructed in the same manner. The pressure-sensitive adhesive composition (urethane copolymer, weight average molecular weight: 1,230,000, molecular weight distribution: 4.3, (Based on solid content) of 1.3 parts by weight of an isocyanate-based curing agent and 0.05 part by weight of a silane coupling agent was coated on 100 parts by weight of a releasing film, and the high refractive index layer A pressure-sensitive adhesive having a dry thickness of 20 占 퐉 was transferred to the opposite surface of the formed PET substrate film and aged to prepare a composite film for a capacitive touch panel.

[Example 12]

And 0.25 parts by weight of a silane coupling agent were used in place of the silane coupling agent.

[Example 13]

And 0.50 parts by weight of a silane coupling agent were used in place of the silane coupling agent.

[Example 14]

And 0.75 parts by weight of a silane coupling agent were used in place of the silane coupling agent.

[Example 15]

And 1.00 parts by weight of a silane coupling agent were used in place of the silane coupling agent.

[Comparative Example 11]

A composite film for a capacitive touch panel was produced in the same manner as in Example 11 except that no silane coupling agent was used.

[Comparative Example 12]

And 1.25 parts by weight of a silane coupling agent were used in place of the silane coupling agent, to prepare a composite film for a capacitive touch panel.

[Comparative Example 13]

And 1.50 parts by weight of a silane coupling agent were used in place of the silane coupling agent.

[Comparative Example 14]

And 1.75 parts by weight of a silane coupling agent were used in place of the silane coupling agent.

[Comparative Example 15]

And 2.00 parts by weight of a silane coupling agent were used in place of the silane coupling agent.

Using the composite film for capacitive touch panel according to Examples 11 to 15 and Comparative Examples 11 to 15, the adhesive force was measured and the residue of the adhesive layer was confirmed by the following Experimental Example 3, and the results are shown in the following Table 3 .

[Experimental Example 3]

The composite film for capacitive touch panels was cut to a width of 25 mm and a length of 175 mm and then lapped with ITO film (double layer ITO film, manufactured by NITTO DENKO CO., LTD.) At room temperature and then left at room temperature for 1 hour to use a peel strength measuring device (AR1000, ChemInstruments) , And the adhesive strength was measured at a peeling speed of 300 mm / min. After the peeling, it was visually confirmed whether the residue of the pressure-sensitive adhesive layer remained on the ITO film.

Pressure-sensitive adhesive composition Silane coupling agent content (wt%) adhesiveness
(gf / 25 mm) Adhesive layer residue
(Reworkability) Example 11 Urethane-based copolymer 0.05 711 ◎ Example 12 Urethane-based copolymer 0.25 924 ◎ Example 13 Urethane-based copolymer 0.50 1136 ◎ Example 14 Urethane-based copolymer 0.75 1542 ◎ Example 15 Urethane-based copolymer 1.00 1898 ◎ Comparative Example 11 Urethane-based copolymer 0.00 506 ◎ Comparative Example 12 Urethane-based copolymer 1.25 2014 X Comparative Example 13 Urethane-based copolymer 1.50 2355 X Comparative Example 14 Urethane-based copolymer 1.75 2454 X Comparative Example 15 Urethane-based copolymer 2.00 2498 X

It is to be understood that the present invention is not limited to the above embodiments and various changes and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention.

1: ITO layer 2: printing layer
3: lead wire (Ag) 4: adhesive layer (Acid Free)
5: PET film 6: high refractive index layer
7: low refractive index layer 8: double-sided tape
9: Image Enhancement Film

Claims (9)

In a composite film for a capacitive touch panel,
Transparent substrate film
Wherein the uppermost layer of the coating layer comprises a coating layer composed of a low refractive index layer having a refractive index of 1.31 to 1.40,
An adhesive layer formed on the opposite surface of the base film on which the coating layer is formed, the adhesive layer being coated with a pressure-sensitive adhesive composition comprising a urethane-based copolymer resin, a curing agent and a silane coupling agent,
Wherein the urethane-based copolymer resin and the curing agent have an acid-free functional group, and the pressure-sensitive adhesive layer is wet-coated. The method according to claim 1,
Wherein the low refractive index layer has an average specular reflectance of 0.1 to 1.5% at an incident angle of 5 ° in a wavelength region of 480 to 680 nm. The method according to claim 1,
Wherein the composite film for a capacitive touch panel has a transmittance and a haze (HAZE) of 93.5% or more and 1.5% or less, respectively. The method according to claim 1,
Wherein the water contact angle of the low refractive index layer is 85 DEG or less. delete The method according to claim 1,
Wherein the current change rate of the base film after formation of the pressure-sensitive adhesive layer is within 20%. The method according to claim 1,
Wherein the silane coupling agent comprises 0.01 to 1 part by weight based on 100 parts by weight of the urethane-based copolymer resin. The method according to claim 1,
Wherein the coating thickness of the adhesive layer is 10 to 100 占 퐉 and the adhesive force of the adhesive composition is 2 to 25 N / 25 mm. The method according to any one of claims 1 to 4 and 6 to 8,
Wherein the base film is any one of a polyethylene terephthalate (PET) film, a triacetate cellulose (TAC) film, a polypropylene (PP) film, and a polyethylene (PE) film.

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