KR20130137998A - Conductive laminate - Google Patents

Abstract

The present invention relates to a conductive laminate which is capable of suppressing air bubbles due to excellent heat resistance while treatment at high temperature is performed and is free of loosening or delamination problems. When the conductive laminate, for example, is used as an electrode plate for touch panel, an exterior stimulus such as pen input and exterior shock can be effectively absorbed or resisted, thereby ensuring excellent durability.

Description

Conductive laminate

The present application relates to a conductive laminate.

Touch panels, for example resistive touch panels, are often used in combination with liquid crystal displays. As the resistive touch panel, for example, a matrix panel and an analog panel can be exemplified.

For example, the matrix type touch panel is formed by forming a rectangular electrode in a direction crossing each other between the pressing side substrate on the input operation side and the non-pressing side substrate on the display side, and then facing each other using a spacer or the like. Can be. In addition, an analog type can be formed by making a pair of electroconductive laminated bodies opposing each conductive film inside and using a spacer. After the current flows through one conductive film and the voltage on the other conductive film can be measured, the opposing conductive film can be contacted by pressing, and the position can be detected through the flow of current in the contact portion. For example, Patent Documents 1 to 3 disclose a conductive laminate having a hard coat layer on its surface as an adhesive layer as a conductive laminate used for a touch panel as described above, so that durability at the time of pressing operation can be ensured. Disclosed are a conductive laminate adhered to a hard coat film.

[Patent Literature]

Patent Document 1: Japanese Patent No. 2667686

Patent Document 2: Japanese Patent No. 4646131

Patent Document 3: Japanese Patent No. 4208454

This application provides a conductive laminated body.

An exemplary electroconductive laminate may include a film base layer on which a conductive film is formed on one surface, and an adhesive layer formed on the film base layer. In one example, the pressure-sensitive adhesive layer may include an acrylic polymer including isobornyl (meth) acrylate and methyl (meth) acrylate.

As a film base material layer contained in an electroconductive laminated body, an optically transparent glass base material layer or a plastic base material layer can be used, for example. As the plastic substrate layer in the above, for example, a polyester base layer, a polyamide base layer, a polyvinyl chloride base layer, a polystyrene base layer, or a polyolefin base layer such as polyethylene or polypropylene may be used. The plastic substrate layer may be a non-oriented or uniaxially or biaxially stretched substrate layer. The film base layer may be subjected to treatment such as corona discharge treatment, ultraviolet irradiation treatment, plasma treatment or sputter etching from the viewpoint of improving the adhesion with the conductive film described later. Such a film base layer may have a thickness of, for example, about 3 μm to 300 μm, 5 μm to 250 μm, or about 10 μm to 200 μm.

On one surface of the film base layer, a conductive film, for example, a transparent conductive film, is formed. The conductive film can be formed by, for example, depositing a film containing a conductive film forming material on one surface of the film base layer through vacuum deposition, sputtering, ion plating, spray pyrolysis, chemical plating or electroplating.

As a material for forming the conductive film, for example, a transparent conductive film can be appropriately selected and used. For example, the conductive film is a metal made of gold, silver, platinum, palladium, copper, aluminum, nickel, chromium, titanium, iron, cobalt or tin, or an alloy of two or more of the above, or indium oxide and tin oxide. , Titanium oxide or cadmium oxide, or a metal compound made of a mixture of two or more of the above, a metal compound made of copper iodide, or the like. The conductive film may be, for example, a crystalline layer or an amorphous layer.

In one example, the conductive film may be a crystal layer including indium tin oxide (ITO). The ITO crystal layer contains, for example, indium oxide as a main component, and also tin oxide, zinc oxide, antimony oxide, aluminum oxide, potassium oxide, cerium oxide, magnesium oxide, cadmium oxide, copper oxide, tungsten oxide or oxide The oxide having a large band gap such as rhenium may be composed of a complex oxide including one or more oxides. For example, the ITO crystal layer is 2.5% to 25% by weight or 7.5% to 17.5% by weight of tin oxide based on indium oxide formed by sputtering using a target containing indium oxide and tin oxide as a main component. The crystal layer may be advantageous from the viewpoint of improving the resistance value and transmittance. The ITO crystal layer may include, for example, 85 wt% to 95 wt% of indium oxide and 5 wt% to 15 wt% of tin oxide in consideration of the resistance value and transmittance.

The thickness of the conductive film can be determined in consideration of flexibility, continuity, transparency, resistance value, and the like, which are required depending on the use of the conductive laminate, for example, and is typically 10 nm to 300 nm or 20 nm to 200 nm. It can be selected within a range.

The conductive laminate may further include a lower coating layer existing between the film base layer and the conductive film. Such a coating layer can be advantageously used for improving the adhesion between the conductive film and the film base layer, and for improving the scratch resistance, the bend resistance and the spot property.

The undercoat layer may include an inorganic material, an organic material, or an organic composite material. The inorganic material may be, for example, SiO _2, MgF ₂ or Al ₂ O _3, etc. may be exemplified an organic material include, an acrylic polymer, urethane polymer, melamine polymer, such as alkyd polymer or a siloxane polymer is to be illustrated As the organic-inorganic composite material, a composite of at least one inorganic material and at least one organic material may be exemplified. In one example, the lower coating layer may be formed using a sol-gel reactant or a thermosetting resin including a mixture of a melamine resin, an alkyd polymer, and an organic silane condensate as a sol-gel reactant or an organic material.

The lower coating layer may be formed by, for example, vacuum deposition, sputtering, ion plating, coating or the like. In addition, the lower coating layer may be formed to a thickness of usually 100 nm or less, 15 nm to 100 nm or 20 nm to 60 nm.

An adhesive layer may be formed on one surface of the film base material layer, for example, the surface on which the conductive film is not formed. The pressure-sensitive adhesive layer may include, for example, an acrylic polymer containing isobornyl (meth) acrylate and methyl (meth) acrylate.

The acrylic polymer is 5 to 30 parts by weight of isobornyl (meth) acrylate, for example isobornyl acrylate and 5 to 40 parts by weight of methyl (meth) acrylate, for example methyl acrylate. It may include wealth. Unless otherwise specified, the unit weight portion in the present specification may mean a weight ratio between the respective components. The isobornyl (meth) acrylate and methyl (meth) acrylate may be included in the polymer as polymerized units, for example. In the present specification, the inclusion of a compound in a polymer as a polymer unit may mean that the compound forms a backbone, for example, a main chain or a side chain of the polymer through a polymerization reaction.

The acrylic polymer may comprise 5 parts by weight to 30 parts by weight or 10 parts by weight to 30 parts by weight of isobornyl (meth) acrylate. When the acrylic polymer contains isobornyl (meth) acrylate in a ratio of 5 parts by weight or more, it is possible to effectively increase the adhesive force of the pressure-sensitive adhesive, and to allow the pressure-sensitive adhesive to effectively suppress bubble generation under high temperature conditions. In addition, by including isobornyl (meth) acrylate in an amount of 30 parts by weight or less, it is possible to effectively maintain the conversion rate during the preparation of the polymer and to adjust the molecular weight to the desired level.

The acrylic polymer may also contain 5 parts by weight to 40 parts by weight or 10 parts by weight to 30 parts by weight of methyl (meth) acrylate. When the acrylic polymer contains methyl (meth) acrylate in a proportion of 40 parts by weight or less, it is possible to effectively increase the adhesive strength of the pressure-sensitive adhesive, and to allow the pressure-sensitive adhesive to effectively suppress bubble generation at high temperature conditions. In addition, when methyl (meth) acrylate is included in 5 parts by weight or more, the conversion rate can be effectively maintained during the preparation of the polymer, and the molecular weight can be adjusted to the desired level.

The acrylic polymer may further include a compound of Formula 1 in an amount of 30 parts by weight to 80 parts by weight. The compound may be included in the polymer, for example, in polymerized units.

[Formula 1]

In Formula 1, R ₁ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ₂ is a straight or branched alkyl group having 2 or more carbon atoms.

In Formula 1, R ₂ may be, for example, a straight or branched alkyl group having 2 to 14 carbon atoms.

As the compound of Formula 1, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, sec-butyl (meth) acrylate, pentyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-ethylbutyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) Acrylate, isononyl (meth) acrylate, lauryl (meth) acrylate and the like can be exemplified. One kind or two or more kinds of the above compounds may be included in the polymer.

The acrylic polymer may further comprise 0.01 to 20 parts by weight of a copolymerizable monomer having a crosslinkable functional group. The copolymerizable monomer may be included in the polymer as, for example, a polymerized unit.

As the copolymerizable monomer having a crosslinkable functional group, for example, the copolymer may be copolymerized with other monomers included in the acrylic polymer such as isobornyl (meth) acrylate, methyl (meth) acrylate or the compound of formula (1). The monomer which has a site | part and also has a crosslinkable functional group can be used. As said crosslinkable functional group, a hydroxyl group, a carboxyl group, an isocyanate group, a glycidyl group, etc. can be illustrated, for example. Copolymerizable monomers having such crosslinkable functional groups are variously known in the field of pressure-sensitive adhesives, and all of these monomers may be used in the polymer. Examples of the copolymerizable monomer having a hydroxyl group or a carboxyl group as a typical crosslinkable functional group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (Meth) acrylate such as 2-hydroxyethyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate or 8-hydroxyoctyl Hydroxyalkyleneglycol (meth) acrylates such as hydroxypropyleneglycol (meth) acrylate; (Meth) acryloyloxypropionic acid, 4- (meth) acryloyloxybutyric acid, acrylic acid dimer, itaconic acid, maleic acid, or Maleic anhydride, and the like, but are not limited thereto.

The acrylic polymer may further comprise other optional comonomers, if desired, and the monomers may be included in the acrylic polymer as polymerized units. As said arbitrary comonomer, (meth) acrylonitrile, (meth) acrylamide, N-methyl (meth) acrylamide, N-butoxy methyl (meth) acrylamide, N-vinyl pyrrolidone, or N- Nitrogen-containing monomers such as vinyl caprolactam and the like; (Meth) acrylic acid esters, alkoxy alkylene glycol (meth) acrylic acid esters, alkoxy alkylene glycol (meth) acrylic acid esters, alkoxy alkylene glycol (Meth) acrylic acid esters, phenoxy alkylene glycol (meth) acrylic acid esters, phenoxy alkylene glycol (meth) acrylic acid esters, phenoxy trialkylene glycol Alkylene oxide group-containing monomers such as polyalkylene glycol (meth) acrylic acid esters and the like; Styrene-based monomers such as styrene or methylstyrene; Glycidyl group-containing monomers such as glycidyl (meth) acrylate; And carboxylic acid vinyl esters such as vinyl acetate, but are not limited thereto. These comonomers may be included in the polymer by selecting one kind or more than two types as appropriate according to need. Such comonomers may be included in the acrylic polymer, for example, in a proportion of 20 parts by weight or less, or 0.1 parts by weight to 15 parts by weight, based on the weight of the other monomer.

Acrylic polymers can be prepared through conventional polymerization methods. For example, a monomer mixture prepared by blending necessary monomers according to the desired monomer composition may be subjected to solution polymerization, photo polymerization, bulk polymerization, suspension polymerization, or emulsion polymerization and emulsion polymerization. If necessary in this process, a suitable polymerization initiator or a molecular weight regulator or chain transfer agent may be used together.

The pressure-sensitive adhesive layer may further contain a thiol compound. Such a thiol compound may be, for example, an oligomer generated from the plastic base layer when the pressure-sensitive adhesive layer is in contact with the conductive film or suppresses a change in the resistance value of the conductive film, or when the pressure-sensitive adhesive layer is in contact with the plastic base layer or the like. Generation of bubbles due to gas or the like can be suppressed.

The thiol compound is, for example, used as a chain transfer agent in the polymerization process of the acrylic polymer and included in the pressure-sensitive adhesive in a state of being bonded to the polymer, independently contained as a separate component, or other small molecules other than the acrylic polymer. It may be included in the pressure-sensitive adhesive in a state in which it is bound to a polymer.

As the thiol compound, for example, a thiol compound of the formula (2) can be exemplified.

(2)

In Formula 2, R is an alkyl group substituted with an alkyl group, a hydroxy group or an oxiranyl group, or a substituent of the following Formula 3.

(3)

는, 화학식 3의 A가 화학식 2의 황 원자(S)에 연결되어 있음을 의미한다. In Formula 3, A is an alkylene group or an alkylidene group, and R _a is hydrogen, an alkyl group, or -L ₁ -C (-L ₂ -OC (= 0) -L ₃ -SH) _n R _(3-n) , Wherein L ₁ to L ₃ are each independently an alkylene group or an alkylidene group, R is an alkyl group, n is a number of 1 to 3,

Means that A in Formula 3 is linked to a sulfur atom (S) in Formula 2.

In Formula 2 or 3, the alkyl group may be an alkyl group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms. The alkyl group may be, for example, straight chain, branched chain or cyclic. In addition, when necessary, it may be substituted with any substituent other than a hydroxyl group or an oxiranyl group.

In Formula 2 or 3, the alkylene group or the alkylidene group may be an alkylene group or an alkylidene group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms. The alkylene or alkylidene group may be, for example, linear, branched or cyclic. And may be optionally substituted with any substituent, if necessary.

As a thiol compound, For example, in the said Formula (2), R is a C3-C20, C3-C16, C3-C12 or C3-C8 linear or branched alkyl group; In Formula 2, R is a linear or branched alkyl group having 1 to 8 or 1 to 4 carbon atoms substituted with a hydroxy group, and R in Formula 2 is a straight chain having 1 to 8 or 1 to 4 carbon atoms substituted with an oxiranyl group Or a branched alkyl group; Or in Formula 2, R is a substituent of Formula 3, A in Formula 3 is a linear or branched alkylene or alkylidene group having 1 to 8 or 1 to 4 carbon atoms, and R _a is a hydrogen atom, 4 to C 12 or a straight or branched chain alkyl group having 4 to 8 carbon atoms, or -L ₁ -C (-L ₂ -OC (= O) -L ₃ -SH) _n R _(3-n) , wherein L ₁ to L ₃ is each independently a linear or branched alkylene group or alkylidene group having 1 to 8 or 1 to 4 carbon atoms, R is a straight or branched alkyl group having 1 to 8 or 1 to 4 carbon atoms, and n is 2 or Compound 3 may be used, but is not limited thereto.

As a thiol compound, 2-mercapto ethanol, glycidyl mercaptan, mercaptoacetic acid, 2-ethylhexyl thioglycolate, 2, 3- dimercapto-1-propanol, n-dodecane thiol, t-butyl mer Captan, n-butyl mercaptan, 1-octadecane thiol, trimethylol propane tris (3-mercapto thiol) or pentaerythritol tetrakis (3-mercapto propionate) and the like can be exemplified.

The thiol compound may be included, for example, in a ratio of 0.001 part by weight to 5 parts by weight or 0.01 part by weight to 4 parts by weight with respect to 100 parts by weight of the acrylic polymer.

The pressure-sensitive adhesive layer may further include, for example, a polyfunctional crosslinking agent that is crosslinking the acrylic polymer. As the polyfunctional crosslinking agent, a known crosslinking agent such as an isocyanate crosslinking agent, an epoxy crosslinking agent, an aziridine crosslinking agent or a metal chelate crosslinking agent can be used without particular limitation. Typically, an isocyanate crosslinking agent may be used as the multifunctional crosslinking agent, but is not limited thereto.

As an isocyanate crosslinking agent, For example, diylene, such as tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isoborone diisocyanate, tetramethyl xylene diisocyanate, or naphthalene diisocyanate An isocyanate compound or a compound obtained by reacting the diisocyanate compound with a polyol may be used, and as the polyol, for example, trimethylol propane may be used, but is not limited thereto.

The multifunctional crosslinking agent may be included in the pressure-sensitive adhesive layer in an amount of 0.01 to 10 parts by weight or 0.1 to 5 parts by weight with respect to 100 parts by weight of the acrylic polymer, and can maintain excellent required physical properties of the pressure-sensitive adhesive layer in this range.

The pressure-sensitive adhesive layer may further include additives such as a silane coupling agent, a tackifier, an epoxy resin, an ultraviolet stabilizer, an antioxidant, a colorant, a reinforcing agent, a filler, an antifoaming agent, a surfactant, or a plasticizer, if necessary for the above components. have.

The pressure-sensitive adhesive layer may have a storage modulus in the range of, for example, 5 × 10 ⁴ Pa to 2 × 10 ⁵ Pa or 5 × 10 ⁴ Pa to 1 × 10 ⁵ Pa at 23 ° C. In this range, the pressure-sensitive adhesive layer can effectively resist or absorb external stimuli. By setting the storage elastic modulus of the pressure-sensitive adhesive layer to 5 × 10 ⁴ Pa or more, the pressure-sensitive adhesive layer exhibits adequate resistance to external magnetic poles, thereby preventing the occurrence of irregularities in the laminate or the pressure of the pressure-sensitive adhesive during processing. In addition, by setting the storage modulus to 2 × 10 ⁵ Pa or less, the pressure-sensitive adhesive layer can effectively absorb external stimuli to improve scratch resistance and spot resistance of the laminate.

The thickness of the pressure-sensitive adhesive layer can be appropriately selected in consideration of cushioning properties and the like, and can be generally selected within the range of 1 µm or more, 5 µm to 500 µm or 5 µm to 10 µm.

In one example, the pressure-sensitive adhesive layer as described above may be formed on a surface on which the conductive film of the film base layer is not formed. FIG. 1: shows the case where the said electroconductive film 101, the film base material layer 102, and the adhesive layer 103 are formed one by one as an exemplary electroconductive laminated body 10. FIG. Although not shown, the lower coating layer may be present between the conductive film 101 and the film base layer 102.

The electroconductive laminate may further include, for example, a transparent sheet layer or a release film layer attached to the film base layer by the pressure-sensitive adhesive layer. FIG. 2 is a diagram illustrating an exemplary laminate 20, and shows the case where the transparent sheet layer 201 is attached via the pressure-sensitive adhesive layer 103 in the structure of FIG. 1. Instead of the transparent sheet layer 201, a release film layer may be included in the conductive laminate.

As the transparent sheet layer, for example, an appropriate kind may be selected and used from a transparent glass or plastic substrate layer which may be used as the film substrate layer. When the transparent sheet layer is included, the thickness of the transparent sheet layer may be adjusted to be thicker than the film base layer. In one example, the thickness of the transparent sheet layer is adjusted within the range of 50 μm to 300 μm, or 75 μm to 200 μm, and the thickness of the film base layer is 3 μm to 100 μm or 10 μm to 50 μm. While being adjusted in the range, the transparent sheet layer can be adjusted to have a higher thickness than the film base layer.

As the release film layer, for example, a release film commonly used in the adhesive sheet field may be used.

The said electroconductive laminated body may further contain the hard coat layer formed in the surface on the opposite side to the surface facing the film base material layer of the said transparent sheet layer further. 3 exemplarily shows a laminate 30 in which a hard coat layer 301 is further formed in the laminate having the structure of FIG. 2.

The hard coat layer can be formed by, for example, a hard coat treatment method in which a hard resin such as an acrylic urethane resin or a siloxane resin is applied and cured. . In the hard coat treatment, a silicone resin or the like is mixed with a hard resin such as the acryl urethane-based resin or siloxane-based resin to roughen the surface of the hard resin, and when it is applied to a touch panel or the like, Plane can be formed at the same time. Such a hard coat layer can be formed to a thickness of about 0.1 to 30 占 퐉 in consideration of the hardness characteristic, the anti-creep characteristic, and the curl prevention characteristic.

Such a conductive laminate can be usefully used, for example, as an electrode plate for a touch panel.

The present application also relates to pressure-sensitive adhesive compositions. Exemplary pressure-sensitive adhesive composition may be used to form a conductive laminate, for example, the conductive laminate described above. The pressure-sensitive adhesive composition may include, for example, an acrylic polymer including 5 parts by weight to 30 parts by weight of isobornyl (meth) acrylate and 5 parts by weight to 40 parts by weight of methyl (meth) acrylate. The pressure-sensitive adhesive composition may also have a storage modulus of 5 × 10 ⁴ Pa to 2 × 10 ⁵ Pa at 23 ° C. after the crosslinking structure is implemented.

As a specific matter of the acrylic polymer or other components contained in the said adhesive composition, or the said storage elastic modulus, the matter described about the adhesive layer in the item of the said electroconductive laminated body can apply equally, for example.

The present application also relates to a method for producing the conductive laminate using the pressure-sensitive adhesive composition. The exemplary method may include forming the pressure-sensitive adhesive layer on one surface of the film base layer on which one surface is formed, for example, the surface opposite to the surface on which the conductive film is formed.

In the above, the film base layer can be produced, for example, by forming a conductive film on one surface of the glass or plastic base layer described above in a conventional manner. In one example, when the conductive film is the above-described ITO crystal layer, the method for forming the conductive film includes forming a conductive film on one surface of the film base layer by sputtering, and heat treating the base layer on which the conductive film is formed. It may include.

The sputtering method of forming the conductive film in the above is not particularly limited, and conventional methods known in the art may be applied. In one example, the DC magnetron sputtering method can be applied to the sputtering method.

The heat treatment in the above, for example, may be performed for about 30 minutes to 12 hours at a temperature of 100 ℃ to 200 ℃. By this heat treatment, the conductive film is crystallized, and generation of carriers in the film can be promoted. By the heat treatment under the above conditions, the scattering factors of carriers, which are transitions and defects of crystal grains in the crystal film, can be reduced, and the formation of carriers can be smoothed. The heat treatment temperature may mean the temperature of the object to be processed, and may be, for example, about 100 ° C to 200 ° C or about 120 ° C to 180 ° C. In addition, the heat treatment time may be, for example, about 30 minutes to 12 hours or about 30 minutes to 5 hours. The crystallization can be sufficiently advanced at a heat treatment temperature of 100 ° C or higher and a treatment time of 30 minutes or higher. By setting the heat treatment temperature to 200 ° C or lower and the time to 12 hours or lower, practical productivity and cost can be maintained have.

The heat treatment may be performed in an oxygen-containing atmosphere. The amount of oxygen in the heat treatment atmosphere may be a trace amount, or may be carried out under an oxygen atmosphere that is present after the substitution of a conventional nitrogen or argon gas. By this heat treatment, the ITO crystal film grows, and the resistivity of the conductive film can be appropriately maintained.

The formation of the conductive film may be performed on the lower coating layer in a state in which a lower coating layer is previously formed on the film base layer.

The method of forming an adhesive layer in the above film base material layer is not specifically limited. For example, the pressure-sensitive adhesive layer is coated on one surface of the film base material layer with an adhesive composition containing an acrylic polymer containing isobornyl (meth) acrylate and methyl (meth) acrylate and other additives such as a crosslinking agent. To form a crosslinked structure, or to form a pressure-sensitive adhesive layer by performing the coating and curing process on one surface of the transparent sheet layer or the release film layer mentioned above, and then may be formed by laminating it on the film base layer.

The method of coating the pressure-sensitive adhesive composition in the above is not particularly limited, and for example, a method of applying the pressure-sensitive adhesive composition by a conventional means such as a bar coater may be used.

The multifunctional crosslinking agent contained in the pressure-sensitive adhesive composition during the coating process is preferably controlled in such a manner that the crosslinking reaction of the functional groups does not proceed from the viewpoint of performing a uniform coating process. Thus, the crosslinking agent can be crosslinked Structure to improve the cohesive force of the pressure-sensitive adhesive, and improve the adhesive property and cuttability.

The coating process is also preferably performed after sufficiently removing the bubble-inducing component such as volatile components or reaction residues in the pressure-sensitive adhesive composition, and thus the crosslinking density or the molecular weight of the pressure-sensitive adhesive is too low to lower the elastic modulus, It is possible to prevent the problem that the bubbles existing between the glass plate and the adhesive layer become large and scatterers are formed inside.

The method of implementing the crosslinking structure by curing the pressure-sensitive adhesive composition subsequent to the coating is not particularly limited. For example, the coating layer may be formed at an appropriate temperature so that a crosslinking reaction of the acrylic polymer and the multifunctional crosslinking agent included in the coating layer may be caused. It can be carried out in such a manner as to maintain.

The present application also relates to a touch panel. An exemplary touch panel may include the conductive laminate or the electrode plate for the touch panel.

As long as the touch panel includes the conductive laminate or the electrode plate, the touch panel may be formed in a known structure including a capacitive type or a resistive film type. The conductive laminate may be used for forming various devices such as a touch panel or a liquid crystal display. For example, in the case of a laminate including a hard coat layer, the conductive laminate is often exposed to external stimuli like a resistive touch panel. It can be usefully used for the exposed device.

In the case of a resistive touch panel, a pair of touch panel electrode plates having a conductive film are disposed to face each other through spacers so that the conductive films face each other, and at least one of the electrode plates described above. It may be a conductive laminate.

FIG. 4 shows a touch panel 40 including an electroconductive laminate of the structure illustrated in FIG. 3 as an electrode plate as a structure of an exemplary touch panel 40.

The panel 40 in FIG. 4 is opposed to each other by using the spacers S so that the conductive films 101 and 401 formed by mutually orthogonally arranging a pair of electrode plates each including the conductive films 101 and 401 face each other. It has the structure arrange | positioned and the electroconductive laminated body illustrated in FIG. 3 is used as an upper electrode plate.

The panel 40 of such a structure turns on the circuit when the conductive films 101 and 401 contact each other when pressure is applied to the upper electrode plate using an input pen or the like, and when the pressure is released, the panel 40 is turned off. It can function as a switch horizontal body which is in the OFF) state. In the structure, the conductive laminate may be included as an electrode plate to exhibit excellent durability. In the panel 40, a conductive film is formed on the base layer 402 of, for example, plastic or glass as a lower electrode plate, or a laminate of any one of the conductive laminates illustrated in FIGS. May be used.

The present application can provide an electroconductive laminate which is excellent in heat resistance and can suppress generation of bubbles even when the treatment is performed at a high temperature, and does not cause problems such as lifting or peeling. For example, even when used as an electrode plate of a touch panel, the conductive laminate can effectively absorb or resist external stimuli and impact such as a pen input, and is excellent in durability.

1 to 3 are diagrams illustrating exemplary conductive laminates.
4 is a diagram illustrating a structure of an exemplary touch panel to which an exemplary conductive laminate is applied.

Hereinafter, the conductive laminate and the like will be described in detail with reference to Examples and Comparative Examples, but the scope of the conductive laminate and the like is not limited to the following examples.

The physical properties in the following examples and comparative examples were evaluated in the following manner.

1. Measurement of the weight average molecular weight and molecular weight distribution of the polymer

The weight average molecular weight and molecular weight distribution of the polymer were measured under the following conditions using GPC (Gel Permeation Chromatography). For the preparation of the calibration curve, the measurement results were converted using standard polystyrene of the Agilent system.

<Conditions for measuring weight average molecular weight>

Meter: Agilent GPC (Agilent 1200 series, USA)

Column: Two PL Mixed B connections

Column temperature: 40 ° C

Eluent: tetrahydrofuran

Flow rate: 1.0 mL / min

Concentration: ~ 2 mg / mL (100 μl injection)

2. Measurement of Storage Modulus of Adhesive

The pressure-sensitive adhesive layer is cut to a size of 15 cm × 25 cm × 25 μm (width × length × thickness), and the cut pressure-sensitive adhesive layer is laminated in five layers. Subsequently, the laminated pressure-sensitive adhesive layer was cut into a circle having a diameter of 8 mm, and then left in the compressed state using glass to stand overnight, thereby improving the wetting at the interface between the layers, thereby resulting in bubbles generated during lamination. Prepare the sample by removing. Subsequently, the sample is placed on a parallel plate, the gap is adjusted, the zero point of Normal & Torque is set, the stabilization of the normal force is confirmed, and the following conditions are measured for the storage modulus. The tensile modulus is obtained by

Measuring instruments and measuring conditions

Measuring instrument: ARES-RDA, TA Instruments Inc. with forced convection oven

Measuring conditions:

geometry: 8 mm parallel plate

gap: around 1 mm

test type: dynamic strain frequency sweep

strain = 10.0 [%], temperature: 30 ℃

initial frequency: 0.4 rad / s, final frequency: 100 rad / s

3. Durability Rating

The conductive laminate produced in Examples or Comparative Examples, wherein the laminate having a structure in which the conductive film, the transparent film, the pressure-sensitive adhesive layer, the transparent film, and the hard coating layer are sequentially formed is left at 150 ° C. for 2 hours, and then the state of the laminate. Was observed to evaluate the durability according to the following criteria (heat treatment durability). In addition, after leaving the laminate at 60 ° C. and 90% relative humidity for 240 hours, the state of the laminate was also observed to evaluate the durability according to the following criteria (moisture heat durability).

<Durability Evaluation Standard>

O: Bubble, interlayer peeling and interlayer lifting do not occur in the laminate

X: Bubbles, delamination or lifting occurs in the laminate

4. Evaluation of adhesion

The pressure-sensitive adhesive composition prepared in Example or Comparative Example is coated on a surface of which a hard coating layer of PET (poly (ethylene terephthalate)) film having a hard coating layer on one surface is not formed so that the thickness after drying is about 25 μm, 120 After aging at 5 ° C. for 5 minutes to form an adhesive layer, the specimen was cut to have a width of 25 mm. Thereafter, the pressure-sensitive adhesive layer of the specimen was applied to a hard coat layer or an ITO conductive layer by applying a load of about 2 Kg, and left for about 30 minutes at room temperature. Thereafter, the specimen was peeled at a peel angle of 180 degrees and a peel rate of 300 mm / min using a tensile tester, and the peel force on the hard coating layer or the ITO conductive layer was measured and described in Table 1 below.

5. Pen Lighting ( pen writing A) durability rating

After reciprocating 150,000 round ends of the pen having a rounded end to the hard coat layer surface of the conductive laminate prepared in Example or Comparative Example 15 times, the visually pressed state was observed and durability was evaluated according to the following criteria.

<Durability Evaluation Standard>

O: Press marks are not visible to the naked eye

X: Press marks are severely observed with the naked eye

Manufacturing example  1. Preparation of Acrylic Polymer (A)

Nitrogen gas was refluxed and 58 parts by weight of n-butyl acrylate, 20 parts by weight of isobornyl acrylate, 20 parts by weight of methyl acrylate, and 2-hydroxyethyl acrylate 2 in a reactor equipped with a cooling device for easy temperature control. Part by weight was added and 150 parts by weight of ethyl acetate was added as a solvent to 100 parts by weight of monomer. Subsequently, 0.03 parts by weight of N-dodecane diol was added to 100 parts by weight of the monomer, and after purging nitrogen gas for about 60 minutes, the temperature was raised to about 60 ° C., and azobisisobutyronitrile as a reaction initiator was used as a monomer. The reaction was initiated by adding 0.04 parts by weight to 100 parts by weight. After the reaction proceeds for about 8 hours, the reaction mixture is cooled and diluted with ethyl acetate to obtain a solid concentration of about 30% by weight so that the molecular weight (Mw) is about 800,000 and the polydispersity index (Mw / Mn) is about 3.2. Acrylic polymer (A) was prepared.

Manufacturing example  2 to 7. Preparation of acrylic polymers (B) to (G)

The molecular weight (Mw) and polydispersity index (Mw / Mn) were polymerized in the same manner as in Preparation Example 1, except that the weight ratio of the monomer introduced into the reactor was changed as shown in Table 1 below. Polymers (B) to (G) were prepared.

Manufacturing example One 2 3 4 5 6 7 Acrylic polymer A B C D E F G only
Amount
sieve BA 58 58 58 58 98 73 58 IBOA 20 20 15 15 - 25 - MA 20 15 20 15 - - 40 HEA 2 2 2 2 2 2 2 Molecular Weight( Mw ) 80 82 78 83 70 50 85 Dispersed  Indices( Mw Of Mn ) 3.2 3.1 3.4 3.2 3.2 3.5 3.0 BA n-butyl Acrylate
IBOA : Isobornyl Acrylate
MA : methyl Acrylate
HEA : 2- Hydroxyethyl Acrylate
Molecular Weight( Mw Unit: only
Content unit: Weight portion

Manufacturing example  8. Conductive film  formation

An Indium Tin Oxide (ITO) conductive film was formed on one surface of a transparent PET film (thickness: about 25 μm) in the following manner. Acid in the coating liquid containing organic silane (phenyltrimethoxy silane), tetraethoxy silane, ethyl alcohol and distilled water in a weight ratio of 1: 6: 7: 2 (organic silane: tetraethoxy silane: ethyl alcohol: distilled water). A catalyst was added and partial hydrolysis reaction was performed at 25 ° C. for about 24 hours to prepare a sol coating solution. The coating solution in the sol state was coated on one surface of the PET film, the solvent was dried by maintaining at about 60 ° C. for about 1 minute, and a gel reaction was performed for 3 minutes in a convection oven at 140 ° C. to form a lower coating layer. Thereafter, a sputtering process was performed in an atmosphere of 5 mTorr including 98.4% by volume of argon gas and 1.6% by volume of oxygen gas to form an ITO conductive film having a thickness of about 20 nm on the lower coating layer.

Example  One.

Preparation of pressure-sensitive adhesive composition

An adhesive composition was prepared by blending the acrylic polymer (A) prepared in Preparation Example 1 and an isocyanate crosslinking agent (TDI, toluene diisocyanate). In the above, the crosslinking agent was blended in a proportion of 0.3 parts by weight based on 100 parts by weight of the solid content of the polymer (A).

Conductivity Of the laminate  Produce

The pressure-sensitive adhesive layer was formed by coating the pressure-sensitive adhesive composition on a surface where the hard coating layer of the transparent PET film having a hard coating layer formed thereon on one surface so that the thickness after drying was about 25 μm, and then maintaining the temperature at 120 ° C. for about 5 minutes. Then, the electrically conductive laminated body was manufactured by laminating to the said adhesive layer the surface in which the electrically conductive film manufactured in the manufacture example 8 is not formed, and the electrically conductive film of PET film formed in one surface.

Example  2.

A conductive laminate was prepared in the same manner as in Example 1, except that the acrylic polymer (B) prepared in Preparation Example 2 was used instead of the acrylic polymer (A) in preparing the pressure-sensitive adhesive composition.

Example  3.

A conductive laminate was prepared in the same manner as in Example 1, except that the acrylic polymer (C) prepared in Preparation Example 3 was used instead of the acrylic polymer (A) in preparing the pressure-sensitive adhesive composition.

Example  4.

A conductive laminate was prepared in the same manner as in Example 1, except that the acrylic polymer (D) prepared in Preparation Example 4 was used instead of the acrylic polymer (A) in preparing the pressure-sensitive adhesive composition.

Comparative Example  One.

A conductive laminate was prepared in the same manner as in Example 1, except that the acrylic polymer (E) prepared in Preparation Example 5 was used instead of the acrylic polymer (A) in preparing the pressure-sensitive adhesive composition.

Comparative Example  2.

A conductive laminate was prepared in the same manner as in Example 1, except that the acrylic polymer (F) prepared in Preparation Example 6 was used instead of the acrylic polymer (A) in preparing the pressure-sensitive adhesive composition.

Comparative Example  3.

A conductive laminate was prepared in the same manner as in Example 1, except that the acrylic polymer (G) prepared in Preparation Example 7 was used instead of the acrylic polymer (A) in preparing the pressure-sensitive adhesive composition.

Physical properties of the pressure-sensitive adhesive or the conductive laminate of Examples or Comparative Examples were measured and summarized in Table 2 below.

Example Comparative Example One 2 3 4 One 2 3 Storage modulus 8.0 7.8 7.9 6.8 4.1 4.8 9.2 Heat treatment durability O O O O X X O Wet heat  durability O O O O X O O Adhesion ( Hard coating layer ) 2730 2640 2650 2610 1050 2230 1840 Adhesion ( Conductive film ) 3010 2970 2700 2650 1230 1580 1660 pen Lighting  durability O O O O X X O Storage modulus: Storage modulus (× 10) at room temperature (23 ° C.) of the pressure sensitive adhesive ⁴ Pa )
Adhesion ( Hard coating layer ): On the hard coating layer  Peel force of adhesive gf / 25 mm )
Adhesion ( Conductive film ): ITO On the conductive film  Peel force of adhesive gf / 25 mm )

10, 20, 30: conductive laminate
101: conductive film
102: film substrate layer
103: adhesive layer
201: transparent sheet layer
301: hard coating layer
40: touch panel
S: Spacer
401: conductive film
402: substrate layer

Claims (16)

A film base layer having a conductive film formed on one surface; And an adhesive layer formed on the film base layer and comprising an acrylic polymer including 5 to 30 parts by weight of isobornyl (meth) acrylate and 5 to 40 parts by weight of methyl (meth) acrylate. Conductive laminate.
The conductive laminate according to claim 1, further comprising a lower coating layer existing between the film base layer and the conductive film.
The conductive laminate of claim 1, wherein the acrylic polymer further comprises 30 parts by weight to 80 parts by weight of the compound of Formula 1:
[Chemical Formula 1]

In Formula 1, R ₁ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ₂ is a straight or branched alkyl group having 2 or more carbon atoms.
The conductive laminate according to claim 1, wherein the acrylic polymer further comprises 0.01 to 20 parts by weight of a copolymerizable monomer having a crosslinkable functional group.
The conductive laminate according to claim 4, wherein the crosslinkable functional group is a hydroxy group, a carboxyl group, a glycidyl group or an isocyanate group.
The conductive laminate according to claim 1, wherein the pressure-sensitive adhesive layer further comprises a polyfunctional crosslinking agent for crosslinking the acrylic polymer.
The conductive layered product according to claim 1, wherein the pressure-sensitive adhesive layer has a storage modulus at 23 ° C of 5 × 10 ⁴ Pa to 2 × 10 ⁵ Pa.
The electroconductive laminated body of Claim 1 in which the adhesive layer is formed in the surface in which the electroconductive film of a film base material layer is not formed.
The conductive laminate according to claim 8, further comprising a transparent sheet layer or a release film layer adhered to the film base layer by the pressure-sensitive adhesive layer.
The conductive laminate according to claim 9, further comprising a hard coat layer formed on a surface on the opposite side of the surface of the transparent sheet layer that faces the film substrate layer.
An electrode plate for a touch panel comprising the conductive laminate of claim 1.
An acrylic polymer comprising 5 to 30 parts by weight of isobornyl (meth) acrylate and 5 to 40 parts by weight of methyl (meth) acrylate, wherein the storage modulus at 23 ° C. is Pressure-sensitive adhesive composition for conductive laminates of 5 × 10 ⁴ Pa to 2 × 10 ⁵ Pa.
The manufacturing method of the electroconductive laminated body containing forming the adhesive layer containing the adhesive composition of Claim 12 on one surface of the film base material layer in which the conductive film is formed in one surface.
The film base layer according to claim 13, wherein the film base layer having the conductive film formed on one surface thereof forms a conductive film on one surface of the base layer by sputtering, and the base layer having the conductive film formed thereon at a temperature of 100 ° C to 200 ° C. Method for producing a conductive laminate formed in a manner comprising the heat treatment for 30 minutes to 12 hours.
A touch panel comprising the conductive laminate of claim 1 or the electrode plate of claim 11.
A pair of touch panel electrode plates having a conductive film are disposed so as to face each other via spacers so that the conductive films face each other, wherein at least one of the electrode plates is the conductive laminate of claim 1 or the electrode plate of claim 11. Touch panel.

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