KR20120088955A - Composite film for electrostatic capacity type touch screen panel - Google Patents

Abstract

PURPOSE: A composite film for electrostatic capacity type touch screen panel is provided to integrate adhesive layers which does not include acid, thereby obtaining electrical stability by preventing oxidation of a silver layer. CONSTITUTION: A composite film for electrostatic capacity type touch screen panel comprises a base film, a coating layer and an adhesive layer(4). In the coating layer, the refractive indexes which are successively coated on the base film are different. The top layer of the coating layer is composed of low refractive index layers having the refractive index of 1.31-1.40. The low refractive index layer has an average specular reflectance of 0.1-1.5% at 5 degrees angle of incidence among the 480-680 nano meters wavelength area. The adhesive layer is formed in the opposite surface of the base film in which a coating layer is formed. The adhesive layer is spread by the adhesive composition which includes a urethane based copolymer resin, a hardening agent and a silane coupling agent.

Description

Composite film for capacitive touch panel {COMPOSITE FILM FOR ELECTROSTATIC CAPACITY TYPE TOUCH SCREEN PANEL}

The present invention relates to a composite film for a capacitive touch panel, and more particularly, by minimizing reflection by light emitted from a BLU of an LCD and improving transmittance, the image quality can be improved, and also no acid is included. A composite film for capacitive touch panels that can simplify the process and reduce the cost while ensuring electrical stability by preventing oxidation of the ITO layer of the ITO film and the silver (Ag) layer of the lead wire by integrating a non-adhesive layer. will be.

In general, a touch screen panel is a device mounted on a surface of a display device and converting a physical contact of a user's finger or touch pen into an electrical signal and outputting the electrical signal. A liquid crystal display and a plasma It is applied to a Plasma Display Panel, an EL (Electro-luminescence) device, and the like.

The touch panel is classified into a capacitive type, a resistive film type, an ultrasonic type, an infrared type, and the like according to an operating principle, and a double capacitive type and a resistive film type are currently widely used. In recent years, the electrostatic capacitive method which is excellent in a characteristic with respect to durability and a transmittance | permeability compared with a resistive film system is attracting attention.

Looking at the structure of the capacitive touch panel as shown in FIG. 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 advanced in the related art is applied. As shown in FIG. 1, there is a printed layer 2 on the edge of the glass for the touch panel and an ITO layer 1 deposited thereon. After depositing the ITO layer 1, etching is performed. Through the formation of a pattern, the Ag layer 3, which is a leader line, is raised on both ends thereof, thereby producing a capacitive touch panel. In Figure 1, the identification number "9" is described later as a composite film for a capacitive touch panel according to an embodiment of the present invention.

In addition, the pressure-sensitive adhesive layer of the image quality improvement film is laminated with the ITO layer, which is an inorganic substrate, and a general problem occurs in that the pressure-sensitive adhesive has a low adhesive strength with respect to the inorganic substrate. In addition, the general adhesive layer contains an acid in the functional group, and if the adhesive layer including the acid is laminated with the ITO film, the silver (Ag) layer of the ITO layer and the leader line is oxidized over time, thereby deteriorating the electrical stability. Occurs. In addition, in the touch panel industry, quality improvement film and adhesive film are purchased separately, and the lamination process is outsourced.Because the two films are purchased separately, management problems and defect management problems occurring during outsourcing (lamination) are high. There are many problems such as price and low yield.

The present invention has been made to solve the above problems, the object of the present invention is to minimize the surface reflectance and at the same time improve the transmittance to improve the image quality, oxidation of ITO and Ag paste layer The present invention is to provide a composite film for a capacitive touch panel that can prevent and at the same time improve the adhesion of the substrate with the ITO film, which is an inorganic substrate.

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

The object is a transparent base film and two or more coating layers having different refractive indices sequentially coated on the base film, wherein the top layer of the coating layer is a coating layer consisting of a low refractive index layer having a refractive index of 1.31 to 1.40 and the substrate having the coating layer formed thereon. A pressure-sensitive adhesive layer formed on the opposite side of the film is achieved by a composite film for a capacitive touch panel comprising a pressure-sensitive adhesive layer 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 is characterized by having an average specular reflectance (average specular reflectance) of 0.1 ~ 1.0% at a 5 ° incidence angle in the wavelength range of 480 to 680 nm.

Preferably, the transmittance and haze of the capacitive touch panel composite film are 93.5% or more and 1.5% or less, respectively.

Preferably, the water contact angle of the low refractive index layer is characterized in that less than 85 °.

Preferably, the urethane-based copolymer resin and the curing agent has an acid free functional group, the adhesive layer is characterized in that the wet coating.

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

Preferably, the silane coupling agent is characterized in that it comprises 0.01 to 1 parts by weight based on 100 parts by weight of the urethane-based copolymer resin (based on solids 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㎛, the adhesive strength of the pressure-sensitive adhesive composition is characterized in that 2 to 25N / 25mm.

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

According to the present invention, the image quality can be improved by minimizing the reflection by the light emitted from the BLU of the LCD and improving the transmittance, and by integrating the adhesive layer containing no acid, the ITO layer and the leader line of the ITO film By preventing the oxidation of the silver (Ag) layer, it has the effect of securing 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.
Figure 2 is a schematic diagram for the current change amount confirmation experiment.

Hereinafter, the present invention will be described in detail with reference to embodiments and drawings of the present invention. These examples are only presented by way of example only to more specifically describe the present invention, it will be apparent to those skilled in the art that the scope of the present invention is not limited by these examples. .

In the case of a general transparent base film and a film having a hard coating layer, reflectance by an external light source is because the reflectance of the surface has an average specular reflectance of 3 to 5% at a 5 ° incidence angle in a wavelength region of 480 to 680 nm. Due to this high reflection surface is a lot of problems caused by the reflected light to degrade the display quality. In order to solve the above problems, the capacitive touch panel composite film according to the present invention comprises a coating layer having two or more layers having different refractive indices on a transparent base film, and a refractive index of 1.31 having no antifouling component at the top layer. By constructing a low refractive index layer of ~ 1.40, the image quality was improved by minimizing the surface reflectance through the multi-layered refractive index control layer while improving the transmittance.

In addition, the pressure-sensitive adhesive layer of the image quality improvement film is laminated with the ITO layer, which is an inorganic substrate, and a general problem occurs in that the pressure-sensitive adhesive is lowered with respect to the inorganic substrate. In order to improve the problems described above, the capacitive touch panel composite film according to the present invention adds a silane coupling agent capable of forming a hydrogen bond with the ITO layer to an adhesive composition including a curing agent, thereby improving adhesion to the ITO layer. By doing so, the adhesive force was improved.

In addition, the general pressure-sensitive adhesive layer contains an acid in the functional group, and the pressure-sensitive adhesive layer containing the acid is laminated with the ITO film. In this case, the silver (Ag) layer of the ITO layer and the leader line is oxidized over time, thereby decreasing electrical stability. A floating problem occurs. In order to solve the above problems, the capacitive touch panel composite film according to the present invention is introduced into the hydroxyl group of the functional group of the urethane copolymer resin included in the pressure-sensitive adhesive layer, by designing the curing agent isocyanate-based, electrical stability is improved Secured.

In addition, in the touch panel industry, the quality improvement film and the adhesive film are purchased separately, and the lamination process is outsourced.Because the two films are purchased separately, management problems, defect management problems during outsourcing (lamination), and high price In the present invention, the above problems are solved by integrating the two films.

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

As can be seen from FIG. 1, which 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, a printed layer 2 on an edge portion of a glass for a touch panel. There is an ITO layer (1) deposited on it, and after depositing such an ITO layer (1) to form a pattern by etching, and the lead layer Ag layer (3) is raised on both ends of the capacitive touch panel As it is manufactured, the ITO layer and the Ag layer come on the lower plate. Therefore, the upper two layers (ITO layer and Ag layer) has a disadvantage in that the electrical conductivity worsens due to the property of being oxidized when exposed to air (oxygen). In order to compensate for this, another protective film is formed to protect the ITO and Ag layers, and it is an object of the present invention to provide a composite film for a capacitive touch panel as the protective film. The structure of the composite film for a capacitive touch panel is to form a pressure-sensitive adhesive layer (4) containing no acid to prevent oxidation of the ITO and Ag layers on the plastic substrate (5), and the transmittance and In order to provide the antireflection function which improves visibility, two or more coating layers having different refractive indices such as the high refractive index layer 6 and the low refractive index layer 7 are included.

Hereinafter will be described in detail with respect to the components of the present invention.

1. High Hardness Layer Fabrication

1.1 High Refractive Hardness Layer

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

In addition, the highly refractive high hardness layer is curable resin containing inorganic fine particles including an oxide of at least one metal selected from Ti, Zr, In, Zn, Sn, Al, and Sb, an anionic dispersant, and a trifunctional or higher functional polymer. (Hereinafter also referred to as "binder"), by coating 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. It is preferably formed. In the case of using the curable resin or the initiator, the curable resin is cured through a polymerization reaction under the influence of heating and / or ionizing radiation after coating, thereby forming a high refractive index high hardness layer excellent in scratch resistance and adhesion.

1.2 Inorganic Particulates

As the inorganic fine particles, oxides of metals (eg, Ti, Zr, In, Zn, Sn, Sb, Al) are preferable, and fine particles of zirconium oxide are most preferable in terms of refractive index. However, from the viewpoint of conductivity, it is preferable to use inorganic fine particles mainly composed of an oxide of at least one metal of Sb, In and Sn. The refractive index can be adjusted to a predetermined range by changing the amount of the inorganic fine particles. When using zirconium oxide as a main component, 1-120 nm is preferable, as for the average particle diameter of the inorganic fine particle in a layer, 1-60 nm is more preferable, and its 2-40 nm are still more preferable. This range is desirable because it reduces haze and improves adhesion to the top layer by dispersion stability and proper 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 layer is 40 to 85% by mass, preferably 50 to 75% by mass, and 60 to 70% by mass relative to the solids of the entire high refractive layer. More preferred. The particle diameter of the inorganic fine particles can be measured by light scattering or electron micrographs. The specific surface area of the inorganic fine particles is preferably 10 to 400 m 2 / g, more preferably 20 to 200 m 2 / g, and most preferably 30 to 150 m 2 / g.

In order to stabilize the dispersion in the dispersion or coating solution or to improve the affinity or binding property with the binder component, physical surface treatments such as plasma discharge treatment and corona discharge treatment, or surfactants, coupling agents and the like are applied to the inorganic fine particles. Chemical surface treatment can also be performed. Particular preference is given to using coupling agents.

As said coupling agent, it is preferable to use an alkoxy metal compound (for example, a titanium coupling agent and a silane coupling agent). In particular, the treatment with a silane coupling agent having an acryloyl or methacryloyl group is effective. Chemical surface treating agents, solvents, catalysts and dispersion stabilizers of inorganic fine particles are described in paragraphs [0058] to [0083] of JP-A-2006-17870.

1.3 Curable Resin

As curable resin, a polymeric compound is preferable and it is preferable to use an ionizing radiation-curable polyfunctional monomer or a polyfunctional oligomer as a polymeric compound. As a functional group in this compound, a photo-, electron beam-, or radiation-polymerizable functional group is preferable, and a photopolymerizable functional group is more preferable.

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

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

In addition, epoxy (meth) acrylates, urethane (meth) acrylates, and polyester (meth) acrylates are also preferably used as the photopolymerizable polyfunctional monomer.

Among these, esters of a polyhydric alcohol and (meth) acrylic acid are preferable, and a polyfunctional monomer having three or more (meth) acryl groups in one molecule is more preferable. Specific examples thereof include trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, 1,2,4-cyclohexane tetra (meth) acrylate, pentaglycerol triacrylate, and pentaerythritol. Tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol triacrylate, dipentaerythritol pentaacrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol hexa ( Meta) acrylate, tripentaerythritol triacrylate, and tripentaerythritol hexatriacrylate. You may use combining two or more types of polyfunctional monomers. The usage-amount of curable resin may be adjusted in the range which satisfy | fills the refractive index of each layer mentioned above.

1.4 polymerization initiator

It is preferable to use a photoinitiator as a polymerization initiator. As a photoinitiator, an optical radical polymerization initiator or a photocationic polymerization initiator is preferable, and an optical radical polymerization initiator is more preferable.

Examples of the radical photopolymerization initiator include acetophenones, benzophenones, benzoyl benzoate of Michler, α-amyl oxime ester, tetramethylthiuram monosulfide and thioxanthones. Examples of commercially available radical photopolymerization initiators include Nippon Kayaku Co., Ltd. KAYACURE of manufacture (eg, DETX-S, BP-100, BDMK, CTX, BMS, 2-EAQ, ABQ, CPTX, EPD, ITX, QTX, BTC, MCA); Ciba Specialty Chemicals Corp. Irgacure of manufacture (eg, 651, 184, 127, 500, 907, 369, 1173, 2959, 4265, 4263); And Sartomer Company Inc. Esacure of manufacture (KIP100F, KB1, EB3, BP, X33, KT046, KT37, KIP150, TZT). In particular, photocleavage-type photoradical polymerization initiators are preferred. The fission type radical photopolymerization initiator is known as Technical Information Institute Co., Ltd. (Published by Kazuhiro Takausu) (1991), described on page 159 of the latest UV curing technology. Examples of commercially available photo split optical radical polymerization initiators include Ciba Specialty Chemicals Corp. Irgacure of manufacture (eg, 651, 184, 127, 907). 0.1-15 mass parts is preferable with respect to 100 mass parts of curable resin, and, as for the usage-amount of a photoinitiator, 1-10 mass parts is more preferable.

In addition to the said photoinitiator, a photosensitizer can also be used. Specific examples of photosensitizers include n-butylamine, triethylamine, tri-n-butylphosphine, Michler's ketones and thioxanthones. Examples of commercially available photosensitizers include Nippon Kayaku Co., Ltd. KAYACURE of manufacture (eg, DMBI, EPA).

The photopolymerization reaction is preferably performed by ultraviolet irradiation after coating and drying the high refractive index layer.

In addition to the above-described components (e.g., inorganic fine particles, curable resins, polymerization initiators, photosensitizers), high refractive index high hardness layers may include surfactants, antioxidants, coupling agents, thickeners, colorants, colorants (e.g. pigments, Dyes), antifoaming agents, leveling agents, flame retardants, ultraviolet absorbers, infrared absorbers, tackifiers, polymerization inhibitors, antioxidants, surface modifiers, conductive metal fine particles and the like.

1.5 solvent

As a solvent, it is preferable to use the liquid whose boiling point is 60-170 degreeC. 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 , Ethyl acetate, propyl acetate, butyl acetate, methyl formate, ethyl formate, propyl formate, butyl formate), aliphatic hydrocarbons (e.g. hexane, cyclohexane), halogenated hydrocarbons (e.g. methylene chloride, chloroform, carbon tetrachloride) Aromatic hydrocarbons (eg benzene, toluene, xylene), amides (eg dimethylformamide, dimethylacetamide, n-methylpyrrolidone), ethers (eg diethyl ether, dioxane, tetrahydrofuran), and Ether alcohols (eg 1-methoxy-2-propanol). Among these, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and butanol are preferable. In particular, as the dispersion medium, methyl ethyl ketone, methyl isobutyl ketone or cyclohexanone is preferable.

It is preferable to use the said solvent so that the coating composition for high refractive index layers may become 2-30 mass% of solid content concentration, and it is more preferable to use so that it may become 3-20 mass% of solid content concentration.

1.6 Formation of High Refractive Hard Layer

It is preferable that the inorganic fine particles containing zirconium oxide as a main component used for a high refractive index high hardness layer are used for formation of a high refractive index layer in a dispersion state. The inorganic fine particles can be dispersed using a disperser. Examples of dispersers include sand grinder mills (eg, bead mills with pins), high speed impeller mills, pebble mills, roller mills, adjusters and colloid mills. Among these, a sand grinder mill and a high speed impeller mill are preferable. Preliminary dispersion processing may be performed. Examples of dispersers used in the predispersion treatment include ball mills, three-roll mills, kneaders and extruders.

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

The high refractive index high hardness layer used for this invention is formed as follows. To the dispersion obtained by dispersing the inorganic fine particles in the dispersion medium as described above, a curable resin (e.g., the ionizing radiation-curable polyfunctional monomer or polyfunctional oligomer described above), a photopolymerization initiator, and the like as a binder precursor necessary for matrix formation are added To prepare a coating composition for forming a high refractive index layer or a medium refractive index layer, the obtained coating composition for forming a high refractive index layer or a medium refractive index layer is coated on a transparent support and cured through a crosslinking reaction or a polymerization reaction of a curable resin. Simultaneously with or after the coating of the high refractive index layer, the binder of the layer is preferably crosslinked or polymerized with a dispersant.

The binder of the high refractive index layer or the medium refractive index layer thus prepared is, for example, the anionic group of the dispersant is taken into the binder as a result of the crosslinking reaction or polymerization reaction of the above-described preferred dispersant and the ionizing radiation-curable polyfunctional monomer or polyfunctional oligomer. Losing form. The anionic groups taken in the binder of the high refractive index layer or the medium refractive index layer have a function of maintaining the dispersed state of the inorganic fine particles, and the crosslinked or polymerized structure gives the binder a film-forming ability, thereby high refractive index containing inorganic fine particles The coating layer is improved in physical strength, chemical resistance and weather resistance.

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

The layer formation through the crosslinking reaction or the 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 in an atmosphere having an oxygen concentration of 2 vol% or less Even more preferably, it is most preferably carried out in an atmosphere having an oxygen concentration of 1 vol% or less.

0.1-20 micrometers is preferable and, as for the thickness of the high refractive hardness layer, 2-8 micrometers is more preferable. Specifically, for example, the main composition is determined by selecting the type of the fine particles and the type of the resin and determining the blending ratio thereof so as to satisfy the film thickness and the refractive index of the high refractive index layer.

2. Low refractive index layer manufacturing

2.1 Low refractive index layer

The low refractive index layer of the composite film for 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 method of forming the low refractive index layer, a transparent thin film of inorganic oxide formed by chemical vapor deposition (CVD) or physical vapor deposition (PVD), in particular vacuum deposition or sputtering, which is a kind of physical vapor deposition method, may be used. Although possible, the method by the all-wet coating using the coating composition for low refractive index layer formation mentioned later is preferable. The low refractive index layer preferably contains inorganic fine particles. Among the inorganic fine particles, at least one type of inorganic fine particles is preferably hollow particles, and hollow particles containing silica as a main component (hereinafter also referred to as "hollow silica particles"). More preferred. 90-130 nm is preferable and, as for the thickness of this refractive layer, 100-120 nm is more preferable. In addition, 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, the strength of the antireflection film having the layers up to the low refractive index layer is preferably at least H, more preferably at least 2H, and most preferably at least 3H, in a pencil hardness test of 500 g load.

In addition, in the case of the anti-reflection film for PDP, in order to improve the anti-fingerprint performance, the contact angle of water on the surface is preferably 95 ° to 120 °, but in the case of the anti-reflection film for touch panels, the touch panel is located inside the touch panel. Since the edge portion of the LCD surface and the double-sided tape are laminated to ensure sufficient adhesive force with the AR surface, the contact angle of the surface with water is preferably 85 ° or less.

2.2 Inorganic Particulates

The inorganic fine particles that can be used for 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 particles will be described with reference to the hollow silica particles below. The refractive index used here represents the refractive index of all the particles, and does not represent the refractive index of silica alone as the outer shell forming the hollow silica particles. At this time, 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 20 to 60% is More preferably, 30 to 60% is most preferred.

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

If the hollow silica particles are intended to have lower refractive index and higher porosity, the outer shell becomes thinner and the strength as particles is lowered. Therefore, from the viewpoint of scratch resistance, particles having a refractive index within the above 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. In addition, commercially available hollow silica particles can also be used.

In addition, the coating amount of the hollow silica particles is preferably 1 to 100 mg / m 2, more preferably 5 to 80 mg / m 2, and even more preferably 10 to 60 mg / m 2. Within this range, a good effect of reducing the refractive index or improving the scratch resistance can be obtained, and the occurrence of minute unevenness on the surface of the low refractive index layer can be prevented, and the appearance (e.g. rich black appearance) and integral reflectance can be reduced. It can be kept well.

Further, the average particle diameter of the hollow silica particles is preferably 30 to 150%, more preferably 35 to 80%, 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, even more preferably 40 to 60 nm. If the particle diameter is within this range, the ratio of the cavity can be maintained satisfactorily, the refractive index can be sufficiently reduced, the occurrence of minute irregularities on the surface of the low refractive index layer can be prevented, and the appearance (eg, a dense black appearance) ) And integrated reflectance can be kept good. The silica fine particles may be crystalline or amorphous, and monodisperse particles are preferable. Although the shape is the most preferable spherical form, there is no problem even if it is indefinite. The average particle diameter of the hollow silica particles can be determined from electron micrographs.

In the present invention, silica particles without cavities may be used in combination with hollow silica particles. The particle size of the silica without cavity 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 may be silica fine particles having the above-described particle diameters ("large particle size silica fine particles"). It is preferable to use in combination with "." The small particle sized silica fine particles may be present in the gap between the large particle sized silica fine particles, and thus may serve as a retainer for the large particle sized silica fine particles. The average particle diameter of the small particle size silica fine particles is preferably 1 to 20 nm, more preferably 5 to 15 nm, even more preferably 10 to 15 nm. The use of such silica fine particles is preferable from the viewpoint of raw material cost and oil retainer effect. In order to stabilize the dispersion in the dispersion or coating solution or to improve affinity or binding to the binder component, physical surface treatments such as plasma discharge treatment and corona discharge treatment for hollow particles, or by surfactants, coupling agents, etc. Chemical surface treatment may also be performed. The use of a coupling agent is particularly preferred. As a coupling agent, it is preferable to use an alkoxy metal compound (for example, a titanium coupling agent and a silane coupling agent). Among these, the treatment with a silane coupling agent having acryloyl or methacryloyl group is effective. Chemical surface treating agents, solvents, catalysts and dispersion stabilizers of hollow particles are described in paragraphs [0058] to [0083] of JP-A-2006-17870.

The low refractive index layer is also 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 irradiation of heating and ionizing radiation. It is preferable to be. The solute is preferably 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. Moreover, it is preferable to use the composition containing a fluorine-containing curable resin, and, as for the low refractive index layer, the aspect which uses the hydrolyzate of organosilyl compound or its partial condensate adjuvant is more preferable. The addition amount of the hydrolyzate or partial condensate of the organosilyl compound used auxiliary is 10 to 40 mass% with respect to the fluorine-containing curable resin.

2.3 Coating composition for low refractive index layer formation

Typically, the coating composition for forming the low refractive index layer is in liquid form, by dissolving the above-mentioned inorganic fine particles and fluorine-containing curable resin, preferably contained in a suitable solvent, and dissolving various additives and radical polymerization initiators as necessary. Are manufactured. Here, the concentration of the solid content may be appropriately selected depending on the use, but about 0.01 to 60% by mass is common, more preferably 0.5 to 50% by mass, still more preferably about 1 to 20% by mass.

The radical polymerization initiator may be either of a type generating radicals under thermal action or a type generating radicals under light action. For compounds which initiate radical polymerization under thermal action, organic or inorganic peroxides, organic azo or diazo compounds and the like may be used.

More specifically, examples of the organic peroxide include benzoyl peroxide, halogen perbenzoyl 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 diazoaminobenzenes and p-nitrobenzenediazonium. When using the compound which starts radical polymerization under light action, a film hardens by irradiation of ionizing radiation. Examples of such radical photopolymerization initiators include acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, and 2,3-dialkyldione compounds. Logistics, disulfide compounds, fluoroamine compounds and aromatic sulfoniums. Examples of acetophenones are 2,2-diethoxyacetophenone, p-dimethylacetophenone, 1-hydroxydimethyl phenyl ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-4-methylthio-2-mo Leporinopropiophenone and 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone. Examples of benzoins include benzoin benzenesulfonic acid ester, benzoin toluenesulfonic 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 phosphine oxides include 2,4,6-trimethylbenzoyldiphenylphosphine oxide. In addition, a sensitizing dye can also be preferably used in combination with such an optical radical polymerization initiator.

The amount of the compound that initiates radical polymerization under the action of heat or light is sufficient if the amount is large enough to initiate the polymerization of the carbon-carbon double bond, and the amount is 0.1 to 15% by mass based on the total solids of the composition for forming the low refractive index layer. It is preferable that it is, It is more preferable that it is 0.5-10 mass%, It is further more preferable that it is 2-5 mass%.

2.4 Solvent

The solvent contained in the coating composition for low refractive index layer is not particularly limited as long as the curable resin can be dissolved or dispersed uniformly without causing precipitation, and may be used in combination of two or more solvents. Preferred examples thereof are 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 (eg methanol, ethanol, isopropyl alcohol, butanol, ethylene glycol), aromatic hydrocarbons (eg toluene, xylene) and water.

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

In order to impart properties such as anti-fingerprint properties, water resistance, chemical resistance and slipperiness, a known silicone-based or fluorine-based fingerprint agent, lubricant, or the like may be appropriately added. When adding such an additive, the amount of the additive added is preferably 0 to 20% by mass, more preferably 0 to 10% by mass, even more preferably 0 to 5% by mass based on the total solids 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, it is preferable that inorganic fine particles, a silane coupling agent, and a lubricant are contained.

As an example of the said silane coupling agent, the 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 More preferred is a silane coupling agent containing (eg, (meth) acryloyl) or a polymerizable acylamino group (eg, acrylamino, methacrylamino). The lubricant is preferably a fluorine-containing compound into which a silicone compound, such as dimethylsilicone, or 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 the coating composition for forming the low refractive index layer, and not only acts as a binder in the composition, but also enables softening of the film coating and improves alkali resistance. In the present invention, the organosilyl compound which is preferably used in the coating composition for forming the low refractive index layer includes a compound represented by the following formula (3).

(3)

R ¹¹ mSi (X ¹¹ ) n

X ¹¹ represents an —OH, a halogen atom, an —OR ¹² group or an —OCOR ¹² group, R ¹¹ represents an alkyl group, an alkenyl group or an aryl group, R ¹² represents an alkyl group, m + n is 4, m and n each represents a positive integer. More specifically, R ¹¹ represents a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms (eg, methyl, ethyl, propyl, i-propyl, butyl, hexyl, octyl) A substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms (eg, vinyl, allyl or 2-buten-1-yl) or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms (eg, 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 (eg, fluorine, chlorine, bromine), hydroxyl group, mercapto group, carboxyl group, epoxy group, alkyl group (eg, Methyl, ethyl, i-propyl, propyl, tert-butyl), aryl groups (e.g. phenyl, naphthyl), aromatic heterocyclic groups (e.g. furyl, pyrazolyl, pyridyl), alkoxy groups (e.g. For example, methoxy, ethoxy, i-propoxy, hexyloxy), aryloxy group (e.g., phenoxy), alkylthio group (e.g., methylthio, ethylthio), arylthio group ( For example, phenylthio), alkenyl groups (eg, vinyl, allyl), acyloxy groups (eg, acetoxy, acryloyloxy, methacryloyloxy), alkoxycarbonyl groups (eg, Methoxycarbonyl, ethoxycarbonyl), aryloxycarbonyl groups (eg phenoxycarbonyl), carbamoyl groups (eg carba 1, N-methylcarbamoyl, N, N-dimethylcarbamoyl, N-methyl-N-octylcarbamoyl), and acylamino groups (eg, acetylamino, benzoylamino, acrylamino, methacrylamino ).

The compound of formula 3 forms a matrix by the so-called sol-gel method which includes hydrolysis and mutual condensation. The compound of formula 3 is represented by the following four formulas.

[Formula 3a] Si (X ¹¹ ) ₄

[Formula 3b] R ¹¹ Si (X ¹¹ ) ₃

[Formula 3c] R ¹¹ ₂ Si (X ¹¹ ) ₂

[Formula 3d] R ¹¹ ₃ SiX ¹¹

The component of general formula (3a) is demonstrated 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-s-part Methoxysilane and tetra-tert-butoxysilane. In particular, tetramethoxysilane and tetraethoxysilane are preferable.

The component of General formula (3b) is demonstrated 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- (perfluorocyclohexyloxy) 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 a -OH, a halogen atom, an -OR ¹² group, or an -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, and 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 Methoxysilane, 3-glycidoxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryl Oxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3,4-epoxycyclohexylethyltrimethoxy 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 ) It includes, and 3- (perfluoro-cyclohexyloxy) silane _{- 4 CH 2 OCH 2 CH 2} CH 2 Si (OCH 3) 3.

Among these, organosilyl compounds having a fluorine atom are preferable. When using the organosil compound which does not have a fluorine atom as R, it is preferable to use methyl trimethoxysilane or methyl triethoxysilane. One of these organosilyl compounds may be used alone, or two or more thereof may be used in combination.

The component of general formula (3c) is demonstrated below. The component of formula 3c is an organosilyl compound represented by the formula R ¹¹ ₂ Si (X ¹¹ ) ₂ {R ¹¹ and X ¹¹ are synonymous with R ¹¹ and X ¹¹ defined in the organosylyl compound used as component of formula 3b. Has}. Here, the plurality of R ¹¹ may not be the same group. Specific examples of the organosilyl compound include dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, di-n-propyldimethoxysilane, di-n-propyldiethoxysilane and di -i-propyldimethoxysilane, di-i-propyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, (CF ₃ CH ₂ CH ₂ ) ₂ Si (OCH ₃ ) ₂ , (CF ₃ CH ₂ 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 Si (OCH ₃ ) ₂ and (C ₂ F ₅ OCH ₂ CH ₂ ) ₂ Si (OCH ₃ ) ₂ . Organosilyl compounds having fluorine atoms are preferred. When using the organosilyl compound which does not have a fluorine atom as R11, dimethyl dimethoxysilane or dimethyl diethoxysilane is preferable. One of the organosilyl compounds represented by the component of the formula (3c) may be used alone or in combination of two or more thereof.

The component of general formula (3d) is demonstrated below. The component of formula 3d is an organosilyl compound represented by the formula R ¹¹ ₃ SiX ¹¹ (where R ¹¹ and X ¹¹ have the same meaning as R ¹¹ and X ¹¹ defined in the organosylyl compound used as component of formula 3b). }. Here, the plurality of R ¹¹ may not be the same. Specific examples of this organosilyl compound include trimethylmethoxysilane, trimethylethoxysilane, triethylmethoxysilane, triethylethoxysilane, tri-n-propylmethoxysilane, tri-n-propylethoxysilane and tri -i-propylmethoxysilane, tri-i-propylethoxysilane, triphenylmethoxysilane and triphenylethoxysilane.

In the present invention, each of the components of Formulas 3a to 3d may be used alone but may be used as a mixture. In this case, the mixing ratio is 0 to 100 parts by mass based on 100 parts by mass of the component Formula 3a. It is preferably 1 to 60 parts by mass, more preferably 1 to 40 parts by mass; The component of the formula (3c) is preferably 0 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, even more preferably 0.5 to 3 parts by mass with respect to 100 parts by mass of the formula (3a); The component of the formula 3d is preferably 0 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, even more preferably 0.5 to 3 parts by mass with respect to 100 parts by mass of the formula 3a component. Among the formulas (3a) to (3d), the proportion of the formula (3a) is preferably 30 mass% or more in 100 mass% of the total organosilyl compounds. When the ratio of the component of Formula 3a is 30% by mass or more, problems such as a decrease in adhesiveness or hardenability of the obtained film coating do not occur, which is preferable. In addition to the components of Formulas 3a to 3d, the compounds 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 may be It is also possible to produce preferably.

2.7 Formation of Low Refractive Index Layer

The low refractive index layer is applied to a coating composition in which hollow particles, fluorine-containing curable resins, organosilyl compounds, and optionally other components are dissolved or dispersed therein, and simultaneously with or after coating and drying, ionizing radiation. It is preferably formed by curing the coating via irradiation (for example, irradiation of light or irradiation of an electron beam) or by crosslinking or polymerization under heating.

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

3. Manufacturing method of urethane adhesive

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

3.1 Adhesive

The adhesive of this invention contains the urethane resin obtained by the manufacturing method of the urethane resin mentioned above. Since the urethane resin obtained by the said manufacturing method has adhesive performance by itself, it can be used as an adhesive as it is. However, by further reacting the secondary hydroxyl group or tertiary hydroxyl group remaining in the urethane resin with the polyisocyanate compound as a crosslinking agent, a pressure-sensitive adhesive having better re-peelability can be obtained. That is, this invention is an adhesive formed by making the said urethane resin and polyisocyanate compound react.

3.2 Curing Agent

As a polyisocyanate compound which can be used as a hardening | curing agent, polyfunctional polyisocyanate, such as the said polyisocyanate compound and these trimethylol propane adduct-type modified bodies, a biuret-type modified body, or an isocyanurate type modified body, is used. Especially, it is preferable that it is a modified body with an average number of functional groups more than two. For example, duranate P301-75E (made by Asahi Kasei Co., trimethylolpropane addition product type HDI, isocyanate group content: 12.9 mass%, solid content: 75 mass%), colonate L (made by Nippon Polyurethane company, trimethylol propane addition). Water type TDI, isocyanate group content: 13.5 mass%, solid content: 75 mass%), etc. can be used. As a polyisocyanate compound, what makes 10-30 mass% of isocyanate group content (except a solvent in the case of a solution) react with 20 mass parts or less with respect to 100 mass parts of urethane resins. Since better repeelability is exhibited, it is more preferable that it is 0.01-10 mass parts. On the other hand, when a polyisocyanate compound is not used, cohesion force falls and coagulation | rupture breaks easily, and when it exceeds 20 mass parts, there exists a tendency for cohesion to be too strong and adhesive force falls. Since the intensity | strength of an adhesive can be adjusted by adjustment of the usage-amount of this polyisocyanate compound, the adhesive which balanced adhesiveness and strength can be obtained easily. It is preferable that a polyisocyanate compound is added to a urethane resin and made to react just before coating the said adhesive to a to-be-adhered body. When making the secondary hydroxyl group which remain | survives in a crosslinking agent and a urethane resin, a urethanation catalyst can be used. As a urethanation catalyst, the urethanation catalyst used at the time of a prepolymer formation reaction can be used.

By reacting the polyisocyanate compound in the present invention, the urethane resin crosslinked through the secondary or tertiary hydroxyl group remaining in the urethane resin is excellent in the balance of adhesion performance and strength, and excellent in re-peelability while maintaining the adhesion performance. It is estimated. Moreover, since it uses the urethane resin mentioned above, it is low cost. Moreover, since it does not contain an acryl-type compound, it is thought that migration to a to-be-adhered body and skin irritation are low. Moreover, since this crosslinked urethane resin has a large molecular weight and it is hard to harden at low temperature, it is thought that the temperature dependency of adhesive force is low. Moreover, it is thought that a low molecular weight compound does not migrate to the surface like a rubber adhesive.

3.3 Silane Coupling Agent

A silane coupling agent is for further strengthening the adhesive force at the time of joining with an ITO layer or a base material, A well-known silane coupling agent can be used. Preferably, 3-glycidoxy propyl trimethoxy silane can be used as a silane coupling agent containing an epoxy group. The epoxy group of the silane coupling agent is bonded to the crosslinkable functional group of the acrylic copolymer, and the alkoxysilane moiety strongly bonds the ITO layer of the ITO film to improve adhesive stability, thereby improving heat and moisture resistance characteristics, and especially at high temperature or humidity conditions. When left under a long time under the role of helping to improve the adhesion durability.

The silane coupling agent is preferably included 0.01 to 1 parts by weight based on 100 parts by weight of the urethane-based copolymer (based on the solid content). If the content is less than 0.01 parts by weight, the adhesive force with the ITO layer of the ITO film may be weak, when the content exceeds 1 part by weight is not good rework.

Hereinafter, the configuration and effects of the present invention will be described in more detail with reference to Examples and Comparative Examples. However, this embodiment is intended to illustrate the present invention in more detail, and the scope of the present invention is not limited to these examples.

Example 1

First, 8 parts by weight of Antimony Zinc Oxide (AZO), 3 parts by weight of an acrylic monomer, and 0.5 parts by weight of a photoinitiator among inorganic fine particles containing an oxide of at least one metal selected from Ti, Zr, In, Zn, Sn, Al, and Sb. After coating a high refractive index coating composition containing 88.5 parts by weight of PGME as a solvent to a polyester substrate (PET film, refractive index: 1.65, Toray Advanced Materials Co., Ltd.) having a thickness of 80 μm using # 2 Mayer bar, It dried at 100 degreeC for 2 minutes, hardened | cured by ultraviolet irradiation, and formed the high refractive index high hardness layer of optical thickness of 100 nm and refractive index of 1.67.

Next, a low refractive index layer coating composition comprising 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 was added to the high refractive layer using # 2 Mayer bar. After application, the resultant was dried in a drier at 100 ° C. for 2 minutes and cured by ultraviolet irradiation to form a low refractive index layer having a thickness of 80 nm and a refractive index of 1.31.

Finally, the pressure-sensitive adhesive composition (urethane copolymer, weight average molecular weight: 1,230,000, molecular weight distribution: 4.3, glass transition temperature: -47 ℃, gel fraction: 85%) containing a hydroxyl group 1.0wt% isocyanate type A pressure-sensitive adhesive composition (based on solids 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 a release film, and then a pressure-sensitive adhesive having a dry thickness of 25 μm was formed on the opposite side of the PET base film having the high refractive index layer. 7 days of aging at room temperature and transfer paper to prepare an adhesive layer to prepare a composite film for capacitive touch panel.

[Example 2]

A composite film for a capacitive touch panel was manufactured 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 manufactured 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 manufactured 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 manufactured 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 manufactured in the same manner as in Example 1, except that the 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 manufactured 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 manufactured 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 manufactured 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 manufactured 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 to measure the surface reflectance through the following Experimental Example 1 and the results are shown in Table 1 below.

[Experimental Example 1]

Black matte tape on the opposite side of the composite film for capacitive touch panels using a UV Spectrophometer [Shimazu UV-PC3600] equipped with an adapter for surface reflectance at an angle of incidence (= reflection angle) of 5 ° in the wavelength region of 380 to 780 nm. The surface reflectance was measured after the backside treatment was black by using a matte paint. After that, the average mirror reflectance was calculated in the range of 480 to 680 nm to evaluate the antireflection performance.

Of high refractive hardness layer
Refractive index (n1) Low refractive index
Refractive index (n2) At 480 ~ 680nm
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]

After the high refractive index layer, the low refractive index layer and the PET base film described in Example 1 were configured in the same manner, the pressure-sensitive adhesive composition (urethane copolymer, weight average molecular weight: 1,230,000, molecular weight distribution: 4.3, glass) containing 0.5 wt% of hydroxyl groups Transition temperature: -47 DEG C, gel fraction: 85%) A pressure-sensitive adhesive composition containing 1.3 parts by weight of isocyanate curing agent and 0.05 parts by weight of silane coupling agent (3-glycidoxypropyltrimethoxysilane) was added to 100 parts by weight of the release film. By coating and laminating a pressure-sensitive adhesive having a dry thickness of 20㎛ on the opposite surface of the PET substrate film formed by coating the high refractive index layer to prepare a composite film for a capacitive touch panel.

[Example 7]

Except that the pressure-sensitive adhesive composition containing a hydroxyl group 1.0wt% was carried out in the same manner as in Example 6 to prepare a composite film for a capacitive touch panel.

[Example 8]

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

[Example 9]

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

[Example 10]

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

[Comparative Example 6]

After the high refractive index layer, the low refractive index layer and the PET base film described in Example 1 were configured 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) containing 0.5wt% of carboxyl groups Temperature: -47 DEG C, gel fraction: 85%) A pressure-sensitive adhesive composition comprising 1.3 parts by weight of an epoxy curing agent and 0.05 parts by weight of a silane coupling agent (3-glycidoxypropyltrimethoxysilane) was coated on a release film to 100 parts by weight. The transfer film was laminated and aged with an adhesive having a dry thickness of 20 μm on the antireflection film to prepare a composite film for a capacitive touch panel.

[Comparative Example 7]

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

[Comparative Example 8]

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

[Comparative Example 9]

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

[Comparative Example 10]

Except for using the pressure-sensitive adhesive composition containing 10.0wt% carboxyl group was carried out in the same manner as in Comparative Example 6 to prepare a composite film for a capacitive touch panel.

By using the composite film for capacitive touch panel according to Examples 6 to 10 and Comparative Examples 6 to 10 through the following Experimental Example 2 to measure the current change rate and the results are shown in Table 2 below.

[Experimental Example 2]

After laminating in the manner shown in Figure 2 after 85 ℃ * 95% * 500hr reliability after measuring the amount of current using the amperage meter (MCP-T600), the amount of current change was confirmed.

Of pressure-sensitive adhesive composition
Functional group kind Of pressure-sensitive adhesive composition
Functional group content (wt%) Current rate of change (%)
[85 ℃ * 95% * 500hr] Example 6 Hydroxyl group (-OH) 0.5 0.01 Example 7 Hydroxyl group (-OH) 1.0 0.01 Example 8 Hydroxyl group (-OH) 2.5 0.01 Example 9 Hydroxyl group (-OH) 5 0.01 Example 10 Hydroxyl group (-OH) 10 0.01 Comparative Example 6 Carboxyl group (-COOH) 0.5 61 Comparative Example 7 Carboxyl group (-COOH) 1.0 69 Comparative Example 8 Carboxyl group (-COOH) 2.5 87 Comparative Example 9 Carboxyl group (-COOH) 5 92 Comparative Example 10 Carboxyl group (-COOH) 10 114

Example 11

The same composition of the high refractive index layer, the low refractive index layer and the PET substrate film described in Example 1 was followed, and the pressure-sensitive adhesive composition (urethane copolymer, weight average molecular weight: 1,230,000, molecular weight distribution: 4.3, glass) contained 1.0 wt% of hydroxyl groups. Transition temperature: -47 DEG C, gel fraction: 85%) The high refractive index layer was coated with a pressure-sensitive adhesive composition (based on solids content) containing 1.3 parts by weight of isocyanate-based curing agent and 0.05 parts by weight of silane coupling agent. Transfer laminated and matured pressure-sensitive adhesive with a dry thickness of 20㎛ on the opposite surface of the formed PET base film to prepare a composite film for a capacitive touch panel.

[Example 12]

A composite film for a capacitive touch panel was manufactured in the same manner as in Example 11 except that 0.25 part by weight of the silane coupling agent was used.

[Example 13]

Except that 0.50 parts by weight of the silane coupling agent was carried out in the same manner as in Example 11 to prepare a composite film for a capacitive touch panel.

Example 14

Except for using a silane coupling agent 0.75 parts by weight was carried out in the same manner as in Example 11 to prepare a composite film for a capacitive touch panel.

Example 15

Except that 1.00 parts by weight of the silane coupling agent was carried out in the same manner as in Example 11 to prepare a composite film for a capacitive touch panel.

Comparative Example 11

Except not using a silane coupling agent was carried out in the same manner as in Example 11 to prepare a composite film for a capacitive touch panel.

[Comparative Example 12]

Except that using 1.25 parts by weight of the silane coupling agent was carried out in the same manner as in Example 11 to prepare a composite film for a capacitive touch panel.

[Comparative Example 13]

A capacitive touch panel composite film was prepared in the same manner as in Example 11 except that 1.50 parts by weight of a silane coupling agent was used.

[Comparative Example 14]

A capacitive touch panel composite film was manufactured in the same manner as in Example 11, except that 1.75 parts by weight of the silane coupling agent was used.

Comparative Example 15

A composite film for a capacitive touch panel was manufactured in the same manner as in Example 11 except that 2.00 parts by weight of a silane coupling agent was used.

Using the composite film for a capacitive touch panel according to Examples 11 to 15 and Comparative Examples 11 to 15 through the following Experimental Example 3 to determine the adhesive force and confirm the residue of the adhesive layer and the results are shown in Table 3 below It was.

[Experimental Example 3]

After cutting the composite film for capacitive touch panel to 25mm in width and 175mm in length, after laminating it to ITO film (Nitto Denko's double layer ITO Film) and leaving it at room temperature for 1 hour, using peel force measuring device (AR1000, Chem Instruments) The adhesive force was measured at a peel rate of 300 mm / min. In addition, it was visually confirmed whether the residue of the adhesive layer remained on the ITO film after peeling.

Pressure-sensitive adhesive composition Silane coupling agent content (wt%) adhesiveness
(gf / 25mm) Adhesive layer residue
(Reworkability) Example 11 Urethane Copolymer 0.05 711 ◎ Example 12 Urethane Copolymer 0.25 924 ◎ Example 13 Urethane Copolymer 0.50 1136 ◎ Example 14 Urethane Copolymer 0.75 1542 ◎ Example 15 Urethane Copolymer 1.00 1898 ◎ Comparative Example 11 Urethane Copolymer 0.00 506 ◎ Comparative Example 12 Urethane Copolymer 1.25 2014 X Comparative Example 13 Urethane Copolymer 1.50 2355 X Comparative Example 14 Urethane Copolymer 1.75 2454 X Comparative Example 15 Urethane 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: printed layer
3: leader line (Ag) 4: adhesive layer (Acid Free)
5: PET film 6: high refractive index layer
7: low refractive index layer 8: double sided tape
9: quality improvement film

Claims (9)

In the composite film for capacitive touch panel,
Transparent base film
A two or more coating layers having different refractive indices sequentially coated on the base film, wherein the top layer of the coating layer is formed of a low refractive index layer having a refractive index of 1.31 to 1.40;
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 coated with a pressure-sensitive adhesive composition comprising a urethane-based copolymer resin, a curing agent and a silane coupling agent. Composite film. The method of claim 1,
The low refractive index layer is characterized in that it has an average specular reflectance of 0.1 to 1.5% at a 5 ° incidence angle in the wavelength range of 480 to 680 nm, a composite film for a capacitive touch panel. The method of claim 1,
The transmittance and haze of the capacitive touch panel composite film are 93.5% or more and 1.5% or less, respectively. The method of claim 1,
The water contact angle of the low refractive index layer is 85 ° or less, characterized in that the composite film for capacitive touch panel. The method of claim 1,
The urethane-based copolymer resin and the curing agent has an acid free (Acid free) functional group, wherein the adhesive layer is characterized in that the wet coating, capacitive touch panel composite film. The method of claim 1,
After the formation of the adhesive layer coated with a pressure-sensitive adhesive composition containing the urethane-based copolymer resin, the current change rate of the base film is characterized in that less than 20%, capacitive touch panel composite film. The method of claim 1,
The silane coupling agent comprises 0.01 to 1 part by weight based on 100 parts by weight of the urethane-based copolymer resin, composite film for a capacitive touch panel. The method of claim 1,
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㎛, the adhesive strength of the pressure-sensitive adhesive composition is characterized in that 2 to 25N / 25mm, composite for capacitive touch panel film. The method according to any one of claims 1 to 8,
The base film is any one of polyethylene terephthalate (PET) film, triacetate cellulose (TAC) film, polypropylene (PP) film or polyethylene (PE) film, composite film for capacitive touch panel.

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