KR20170093558A - Conductive laminate - Google Patents

Abstract

The present invention relates to a conductive laminate and a usage thereof. According to the present invention, since the conductive laminate can effectively restrain bubble from being generated around a stepped unit even if the conductive laminate is attached to a substrate having a stepped surface, and can improve adhesion on an ITO surface at the same time, thereby maintaining an exterior or the performance of a product to which the conductive laminate is applied. For example, the conductive laminate can be usefully used for a touch panel or the like.

Description

Conductive laminate {CONDUCTIVE LAMINATE}

The present application relates to a conductive laminate and its use.

BACKGROUND ART [0002] A touch panel or a touch screen is variously applied to various information processing terminals such as a mobile communication terminal or an ATM, or a display device such as a TV and a monitor. In addition, as the application to small portable electronic devices increases, there is an increasing tendency for a smaller and lighter touch panel or screen.

In constructing the touch panel or the screen, for example, a conductive laminate as disclosed in Patent Document 1 or 2 is used. Such a conductive laminate may include a pressure-sensitive adhesive layer. It is important that the conductive laminate does not generate air bubbles when it is laminated to another substrate through the pressure-sensitive adhesive layer. When bubbles are generated, the design of the screen is remarkably deteriorated, which may affect the appearance and cause deterioration of the performance.

Patent Document 1: Korean Patent Publication No. 2002-0036837 Patent Document 2: Korean Patent Publication No. 2001-0042939

An object of the present invention is to provide a conductive laminate capable of effectively suppressing the generation of bubbles in the vicinity of a step portion and exhibiting excellent adhesion to an ITO surface even when attached to a substrate having a surface step difference, and a use thereof.

The present application relates to a conductive laminate. Fig. 1 exemplarily shows the structure of the conductive laminate according to the first embodiment of the present application. As shown in Fig. 1, the conductive laminate 1 comprises a base layer 101; And a first conductive layer (201) formed on one side of the substrate layer; And a pressure-sensitive adhesive layer (30) adhered to a surface of the first base layer on which the first conductive layer is not formed. Hereinafter, the conductive laminate of the present application will be specifically described.

[Base layer]

The type of the base layer 101 is not particularly limited, and for example, a glass base material or a plastic base material can be used. Examples of the plastic substrate include a polyethylene terephthalate film, a polytetrafluoroethylene film, a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polyvinyl chloride film, an ethylene-vinyl acetate film, A copolymer film, an ethylene-ethyl acrylate copolymer film, an ethylene-methyl acrylate copolymer film, or a polyimide film, but is not limited thereto.

The thickness of the base layer 101 is not particularly limited and may be suitably set as long as it can function as a conductive laminate. For example, the thickness of the substrate layer may be in the range of about 1 탆 to 500 탆, about 3 탆 to 300 탆, about 5 탆 to 250 탆, or about 10 탆 to 200 탆.

The substrate layer 101 may be subjected to appropriate bonding treatment such as, for example, corona discharge treatment, ultraviolet ray irradiation treatment, plasma treatment, or sputter etching treatment, but the present invention is not limited thereto.

[First conductive layer]

The conductive layer 201 may be formed on one surface of the base layer 101. Examples of the material constituting the conductive layer 201 include metals such as gold, silver, platinum, palladium, copper, aluminum, nickel, chromium, titanium, iron, cobalt, tin, Tin oxide, titanium oxide, cadmium oxide, or a mixture of two or more of the above metals, copper iodide, and the like. The conductive layer may be a crystalline layer or an amorphous layer. In one example, indium tin oxide (ITO) may be used as the material of the conductive layer, but the present invention is not limited thereto.

The thickness of the conductive layer 201 may be adjusted within a range of about 10 nm to 300 nm, about 10 nm to 200 nm, or about 10 nm to 100 nm in consideration of the possibility of forming a continuous coating, conductivity, transparency, But is not limited thereto.

The method for forming the conductive layer 201 is not particularly limited and may be a conventional thin film forming method in which a vacuum deposition method, a sputtering method, an ion plating method, a spray pyrolysis method, a chemical plating method, an electroplating method, And can be usually formed by a vacuum evaporation method or a sputtering method.

The conductive layer 201 may be formed on one side of the base layer 101 via an anchor layer or a dielectric layer if necessary. The anchor layer or the dielectric layer improves the adhesion between the conductive layer 201 and the base layer 101, and improves scratch resistance or flex resistance.

In addition, the anchor layer or the dielectric layer as described above is, for example, inorganic substances such as SiO _2, MgF ₂ or A _l2 O _3; A sputtering method, an ion plating method, or a coating method using an organic material such as an acrylic resin, a urethane resin, a melamine resin, an alkyd resin or a siloxane-based polymer, or a mixture of two or more of them. The anchor layer or dielectric layer may be formed generally at a thickness of about 100 nm or less, specifically 15 nm to 100 nm or 20 nm to 60 nm.

 [Pressure sensitive adhesive layer]

The pressure-sensitive adhesive layer 30 may be attached to a surface of the base layer 101 on which the conductive layer 201 is not formed. The pressure-sensitive adhesive layer 30 may contain the pressure-sensitive adhesive composition in a cured state. The pressure-sensitive adhesive composition may include an acrylic polymer and a tackifier. As used herein, the term " polymer " may refer to a polymer in which one or more different monomers are mixed and polymerized. In one example, the pressure-sensitive adhesive layer 30 may include the acrylic polymer in a crosslinked state. Hereinafter, the storage modulus or loss modulus of the pressure-sensitive adhesive layer 30 refers to the storage modulus or loss modulus of the pressure-sensitive adhesive layer 30 containing the acrylic polymer in a crosslinked state, unless otherwise specified. When the pressure-sensitive adhesive layer 30 is adhered to another substrate having a surface step difference, the physical properties and composition of the pressure-sensitive adhesive layer 30 can be controlled as follows in terms of suppressing the formation of bubbles in the peripheral portion of the step.

The pressure-sensitive adhesive layer (30) may satisfy the following general formula (1)

 [Formula 1]

1? G '/ G "? 5

G 'and G "denote the storage elastic modulus (G') and the loss elastic modulus (G") of the pressure-sensitive adhesive layer at a temperature of 50 ° C and a frequency of 1 rad / sec, respectively. The upper limit of G '/ G "in the general formula 1 may be, for example, not more than 5, not more than 4.5, not more than 4, not more than 3.5 or not more than 3, and the lower limit of G' / G" , 1 or more, 1.5 or more, or 2 or more. When the pressure-sensitive adhesive layer 30 satisfies the above-mentioned general formula (1), the ratio of the storage elastic modulus to the loss elastic modulus is increased to effectively suppress the generation of bubbles in the vicinity of the step portion, An excellent adhesion can be exhibited.

Specifically, the pressure-sensitive adhesive layer 30 has a storage modulus at a temperature of 50 ° C. and a frequency of 1 rad / sec of less than 1.7 × 10 ⁴ Pa, 1.6 × 10 ⁴ Pa or less, 1.5 × 10 ⁴ Pa or less, 1.4 10 ⁴ Pa or less, or 1.3 10 ⁴ Pa or less. The lower limit of the storage elastic modulus of the pressure-sensitive adhesive layer 30 at a temperature of 50 ° C and a frequency of 1 rad / sec may be 1.0 × 10 ⁴ Pa or more, for example. The term " storage elastic modulus " as used herein generally means " dynamic storage modulus ". That is, when a sine-shaped shear strain is applied to an elastic body, a stress is delayed in an intermediate form in the case of a viscoelastic material. Mathematically, one component is in the same phase and the other component is delayed by pi / 2 In this case, energy stored in the same phase, that is, the energy stored without loss by elasticity, can be referred to as a " dynamic storage modulus " or " storage modulus ". By adjusting the storage modulus of the pressure-sensitive adhesive layer within the above-mentioned range, even when adhered to a substrate having a surface step difference, the generation of bubbles in the peripheral portion of the step can be effectively suppressed and the adhesion to the ITO surface can be improved.

The pressure-sensitive adhesive layer 30 is also, 50 ℃ temperature and loss elastic modulus at 1 rad / sec frequency (Loss Modulus) is 1.0 × 10 ⁴ Pa or less, 0.9 × 10 ⁴ Pa or less, 0.8 × 10 ⁴ Pa or less, or 0.7 × 10 ⁴ Pa or less. The lower limit of the loss elastic modulus of the pressure-sensitive adhesive layer 30 at the temperature of 50 DEG C and the frequency of 1 rad / sec may be, for example, 0.110 ⁴ Pa or more. As used herein, the term " loss modulus " means " dynamic loss modulus " That is, when sine shear deformation is applied to the elastic body as described above, energy that is irreversibly lost due to the portion shifted by pi / 2, that is, converted to heat due to elasticity is referred to as " dynamic loss elastic modulus &Quot; modulus of elasticity ". The loss elastic modulus of the pressure-sensitive adhesive layer 30 can be controlled within the above-mentioned range, so that even when adhered to a substrate having a surface step difference, bubble formation in the peripheral portion of the step can be suppressed.

The acrylic polymer may include alkyl (meth) acrylate as polymerized units. In the present specification, when a monomer is contained in a polymer as a polymerized unit, it may mean a form in which the monomer undergoes a polymerization reaction to form a skeleton of the polymer, for example, a main chain or a side chain.

The acrylic polymer may include an alkyl (meth) acrylate having an alkyl group having 5 or more carbon atoms as a first monomer and an alkyl (meth) acrylate having an alkyl group having 1 to 4 carbon atoms as a second monomer as a polymerization unit. When the acrylic polymer includes the monomer polymerized units, the pressure-sensitive adhesive layer may exhibit the above-described loss or storage elastic modulus range, and even when the pressure-sensitive adhesive layer is adhered to a substrate having a surface step difference, .

As the first monomer, for example, alkyl (meth) acrylates having an alkyl group having 5 or more carbon atoms can be used. The alkyl group is not particularly limited when it has 5 or more carbon atoms, but may be, for example, a branched chain or straight chain alkyl group, more preferably a straight chain alkyl group. Examples of the first monomer include monomers such as pentyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, ethylhexyl (meth) acrylate, nonyl Acrylate and the like, and one or more of the above can be used. As an embodiment of the present invention, 2-ethylhexyl (meth) acrylate can be used, but is not limited thereto. The upper limit of the carbon number of the alkyl group of the first monomer is not particularly limited. For example, an alkyl (meth) acrylate having an alkyl group having 20 or less carbon atoms, 18 or less carbon atoms, 16 or less carbon atoms, 14 or less carbon atoms, 12 or less carbon atoms, Can be used.

The first monomer may be contained in an amount of about 60 parts by weight to 98 parts by weight based on 100 parts by weight of the acrylic polymer. In the present specification, the unit " weight part " may mean a ratio of the weight between the respective components. More specifically, the first monomer is present in an amount of at least about 60 parts by weight, at least about 65 parts by weight, at least about 70 parts by weight, at least about 75 parts by weight, at least about 80 parts by weight, at least about 85 parts by weight, May be included in the acrylic polymer in a proportion of at least about 90 parts by weight. The upper limit of the content ratio of the first monomer polymerized units in the acrylic polymer may be, for example, about 98 parts by weight or less, about 95 parts by weight or less, about 90 parts by weight or about 85 parts by weight or less. In this range, the pressure-sensitive adhesive layer can increase the ratio of the storage elastic modulus to the loss elastic modulus, so that even when adhered to a substrate having a surface step difference, bubbles in the periphery of the step can be effectively suppressed and adhesion to the ITO surface can be improved have.

As the second monomer, an alkyl (meth) acrylate having an alkyl group having 1 to 4 carbon atoms can be used. The alkyl group having 1 to 4 carbon atoms is not particularly limited, but may be, for example, a branched chain or straight-chain alkyl group, more preferably a straight-chain alkyl group. Examples of such monomers include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, Butyl (meth) acrylate, sec-butyl (meth) acrylate, and the like can be exemplified. According to one embodiment of the present application, methyl (meth) acrylate can be used but is not limited thereto.

The second monomer may be contained in an amount of 1 part by weight to 20 parts by weight based on 100 parts by weight of the acrylic polymer. Specifically, the second monomer is used in an amount of 1 part by weight or more, 2 parts by weight or more, 4 parts by weight or more, 6 parts by weight or more, 8 parts by weight or more and 20 parts by weight or less, 18 parts by weight or less, 16 parts by weight No more than 14 parts by weight, or no more than 12 parts by weight. In this range, the pressure-sensitive adhesive layer 30 can increase the ratio of the storage elastic modulus to the loss elastic modulus, and even when attached to a substrate having a surface step difference, the generation of bubbles in the peripheral portion of the step is more effectively suppressed and the adhesion to the ITO surface is improved .

The acrylic polymer may further include a crosslinkable monomer polymerized unit. As used herein, the term " crosslinkable monomer " may mean a monomer capable of providing a crosslinkable functional group to a polymer when the polymer contains other functional groups capable of forming an acrylic polymer with a crosslinkable functional group.

In the production of pressure-sensitive adhesives, various monomers that can be used as crosslinking monomers are known, and these monomers can all be used in the acrylic polymer. Examples of the crosslinkable monomer include a compound containing a nitrogen-containing functional group such as a hydroxyl group, a carboxyl group, an epoxy group, an isocyanate group or an amino group. Specific examples of the crosslinkable monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl Acrylate, 2-hydroxyethyleneglycol (meth) acrylate, 2-hydroxypropyleneglycol (meth) acrylate and the like; (Meth) acryloyloxypropionic acid, 4- (meth) acryloyloxybutyric acid, acrylic acid dimer, itaconic acid, maleic acid, or Carboxyl group-containing monomers such as maleic anhydride; Or nitrogen-containing monomers such as (meth) acrylamide, N-vinylpyrrolidone or N-vinylcaprolactam, and mixtures of one or more of the above may be used.

When the acrylic polymer includes a crosslinkable monomer polymerized unit, for example, the crosslinkable monomer may be contained in an amount of 1 to 20 parts by weight based on 100 parts by weight of the acrylic polymer. Specifically, the crosslinkable monomer is used in an amount of 1 part by weight or more, 2 parts by weight or more, 4 parts by weight or more, 6 parts by weight or more, 8 parts by weight or more and 20 parts by weight or less, 18 parts by weight or less, 16 parts by weight No more than 14 parts by weight, or no more than 12 parts by weight. In this range, the pressure-sensitive adhesive layer can increase the ratio of the storage elastic modulus to the loss elastic modulus, and even when adhered to a substrate having a surface step difference, it is possible to effectively suppress the generation of bubbles in the peripheral portion of the step and improve the adhesion to the ITO surface. The method for producing the acrylic polymer is not particularly limited and can be produced in a usual manner. The acrylic polymer can be polymerized by, for example, an LRP (Living Radical Polymerization) method, and examples thereof include an organic rare earth metal complex as a polymerization initiator or an organic alkali metal compound as a polymerization initiator to form an alkali metal or alkaline earth metal , An anion polymerization method in which an organic alkali metal compound is used as a polymerization initiator and synthesized in the presence of an organoaluminum compound, an anion polymerization method using an atom transfer radical polymerization agent as a polymerization initiator, (ATRP), Atomic Transfer Radical Polymerization (ATRP), and ICAR (Atomization Transfer), which perform polymerization under an organic or inorganic reducing agent that generates electrons using an atom transfer radical polymerization agent as a polymerization initiator. Initiators for continuous activator regeneration) (RAFT) using a reversible addition-cleavage chain transfer agent using an inorganic reductant chain transfer agent, or an organic tellurium compound as an initiator. Among these methods, an appropriate method can be selected and applied have.

The pressure-sensitive adhesive composition may include a tackifier. In the case of including the tackifier, the pressure sensitive adhesive layer 30 can increase the ratio of the storage elastic modulus to the loss elastic modulus, and even when the pressure sensitive adhesive layer is adhered to the substrate having the surface step difference, .

Examples of the tackifier include, for example, hydrocarbons or hydrogenated products thereof, rosin resins or hydrogenated products thereof, rosin ester resins or hydrogenated products thereof, terpene resins or hydrogenated products thereof, terpene phenol resins or hydrogenated products thereof, Or a polymerized rosin ester resin, or a mixture of two or more of them may be used, but the present invention is not limited thereto. The tackifier may be included in the pressure-sensitive adhesive layer 30 at a ratio of 5 parts by weight to 100 parts by weight based on 100 parts by weight of the acrylic polymer. More specifically, the tackifier may be included in the pressure-sensitive adhesive layer 30 at a ratio of 5 or more, 10 or more, 20 or more, 30 or more, or 40 or more to 100 parts by weight of the acrylic polymer. The upper limit of the content ratio of the tackifier in the acrylic polymer is not particularly limited, but may be, for example, about 100 parts by weight, about 90 parts by weight, about 80 parts by weight, about 70 parts by weight or about 60 parts by weight have. In this range, the pressure-sensitive adhesive layer 30 can increase the ratio of the storage elastic modulus to the loss elastic modulus, thereby effectively suppressing the generation of bubbles in the periphery of the step portion even when attached to a substrate having a surface step difference, .

The pressure-sensitive adhesive layer 30 may further include a crosslinking agent capable of crosslinking the acrylic polymer. The crosslinking agent may be a crosslinking agent having at least one, more preferably from 1 to 10, from 1 to 8, from 1 to 6, or from 1 to 4 functional groups capable of reacting with the crosslinkable functional group contained in the acrylic polymer Crosslinking agents may be used. As such a crosslinking agent, an appropriate type can be selected and used from among conventional crosslinking agents such as an isocyanate crosslinking agent, an epoxy crosslinking agent, an aziridine crosslinking agent and a metal chelate crosslinking agent in consideration of the kinds of crosslinkable functional groups of the acrylic polymer.

Examples of the isocyanate crosslinking agent include diisocyanate compounds such as tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isoboron diisocyanate, tetramethylxylene diisocyanate, and naphthalene diisocyanate; A reaction product such as a polyol such as trimethylol propane or an isocyanurate adduct of the above diisocyanate compound. Of these, xylene diisocyanate or hexamethylene diisocyanate can be preferably used. As the epoxy crosslinking agent, , Ethylene glycol diglycidyl ether, triglycidyl ether, trimethylol propane triglycidyl ether, N, N, N ', N'-tetraglycidyl ethylenediamine and glycerin diglycidyl ether. It is at least one selected from can be illustrated.

Aziridine crosslinking agents include N, N'-toluene-2,4-bis (1-aziridinecarboxamide), N, N'-diphenylmethane-4,4'-bis (1-aziridinecarboxamide ), Triethylene melamine, bisisoproparyl-1- (2-methyl aziridine), or tri-1-aziridinyl phosphine oxide, but the present invention is not limited thereto. The metal chelate crosslinking agent A compound in which a polyvalent metal such as aluminum, iron, zinc, tin, titanium, antimony, magnesium and / or vanadium is coordinated to acetylacetone or ethyl acetoacetate, and the like.

The crosslinking agent is used in an amount of, for example, 0.001 to 10 parts by weight, 0.01 to 10 parts by weight, 0.01 to 9 parts by weight, 0.01 to 8 parts by weight, 0.01 to 7 parts by weight, 0.01 to 6 parts by weight, 0.01 to 5 parts by weight, 0.01 to 4 parts by weight, 0.01 to 3 parts by weight, 0.01 to 2 parts by weight or 0.01 to 1 part by weight . In this range, the pressure-sensitive adhesive layer 30 can exhibit the storage or loss elastic modulus range described above, and even when attached to a substrate having a surface step difference, it is possible to effectively suppress the formation of bubbles in the peripheral portion of the step, .

The pressure-sensitive adhesive layer 30 may further include a silane coupling agent. As the silane coupling agent, for example, a silane coupling agent having a beta-cyano group or an acetoacetyl group can be used. Such a silane coupling agent can make the pressure-sensitive adhesive formed by, for example, a polymer having a low molecular weight exhibit excellent adhesion and adhesion stability. When the pressure-sensitive adhesive layer 30 further comprises a silane coupling agent, the silane coupling agent may be included in an amount of 0.01 to 5 parts by weight or 0.01 to 1 part by weight based on 100 parts by weight of the acrylic polymer.

The pressure-sensitive adhesive layer 30 may further include at least one additive selected from the group consisting of a curing agent, a UV stabilizer, an antioxidant, a colorant, a reinforcing agent, a filler, a defoamer, a surfactant and a plasticizer, if necessary.

The method for producing the pressure-sensitive adhesive layer (30) is not particularly limited, and can be produced in a usual manner. For example, a pressure-sensitive adhesive composition in which an acrylic polymer is present in a crosslinked state can be prepared by applying the composition to an appropriate processing substrate by conventional means and curing the composition. In the present application, it is preferable that the curing process is performed after sufficiently removing bubble-inducing components such as volatile components or reaction residues contained in the pressure-sensitive adhesive composition. Accordingly, the crosslinking density or the molecular weight of the pressure-sensitive adhesive is too low to lower the elastic modulus, and bubbles existing in the pressure-sensitive adhesive interface at high temperature are increased to form a scattering body therein. The method of curing the pressure-sensitive adhesive composition is not particularly limited. For example, the pressure-sensitive adhesive composition may be cured by suitable heating, drying and / or aging processes or by curing by electromagnetic wave irradiation such as ultraviolet .

The adhesive force of the pressure-sensitive adhesive layer (30) can be measured at a peel angle of 180 ° and a peel rate of 0.3 m / min. In one example, the pressure-sensitive adhesive layer 30 may have an adhesive strength to ITO (Indium Tin Oxide) of 900 gf / in or more, measured at a peeling angle of 180 ° and a peeling speed of 0.3 m / min, 1000 gf / in, 1050 gf / in, 1100 gf / in, 1150 gf / in, 1200 gf / in, 1250 gf / in, 1300 gf / in, 1350 gf / in Or more, 1400 gf / in, 1450 gf / in, 1500 gf / in, 1550 gf / in, 1600 gf / in, or 1650 gf / in. The pressure-sensitive adhesive layer 30 can have an excellent adhesive force within the above-described range with respect to the ITO surface.

[Second base layer and second conductive layer]

The conductive laminate of the present application may further include a second base layer and a second conductive layer. Hereinafter, the above-described base layer and conductive layer are referred to as a first base layer and a first conductive layer, respectively, for the purpose of classification. Fig. 2 exemplarily shows the structure of the conductive laminate 2 according to the second embodiment of the present application. As shown in Fig. 2, the conductive laminate 2 comprises a first base layer 101; A first conductive layer 201 formed on one surface of the first base layer 101; And a pressure-sensitive adhesive layer (30) adhered to a surface of the first base layer on which the first conductive layer is not formed. The conductive laminate 2 includes a second conductive layer 202 formed on one surface of the second base layer 102 and the second base layer 102 and having a surface level difference 2021. The surface of the first base layer 101 on which the first conductive layer is not formed and the surface of the second conductive layer 202 having a step difference may exist in the state of being adhered by the adhesive layer 30 have.

As used herein, the term " surface step " may mean the difference in height of the surface (shown as H in Fig. 2). The step difference of the surface of the second conductive layer 202 may be derived, for example, from a pattern electrode used in a touch panel to be described later. The pattern shape of the pattern electrode is not particularly limited and may be, for example, a mesh shape or a shape in which electrodes having a polygonal or circular cross-section are spaced apart from each other. The material of the pattern electrode is not particularly limited and may be any one of silver (Ag), aluminum (Al), copper (Cu), chromium (Cr), nickel (Ni), molybdenum . ≪ / RTI > In another example, the step difference of the surface of the second conductive layer 202 may be printed printed steps, for example, to improve the design of the screen.

The thickness of the surface step of the second conductive layer 202 is not particularly limited and may be suitably selected according to the application to which the structure causing the surface step difference is applied, but it may be usually within the range of about 1 to 150 mu m. The thickness range of the pressure-sensitive adhesive layer is not particularly limited, but may be, for example, in the range of 15 m to 30 m. In another example, the thickness of the pressure-sensitive adhesive layer may have a thick thickness range of, for example, about 2 占 퐉 or more, compared with the thickness of the surface step difference. When the pressure-sensitive adhesive layer 30 has a thickness within the above-described range, it is possible to effectively reduce the generation of bubbles in the peripheral portion of the surface step of the second conductive layer 202 (shown by A in FIG. 2).

The conductive laminate includes the above-described base layer, conductive layer and pressure-sensitive adhesive layer as basic units, and if necessary, other elements usually used for forming the conductive laminate, such as a transparent sheet layer, a release film layer or a hard coating layer May be further included.

The present application also relates to the use of the conductive laminate. The conductive laminate of the present application can be used, for example, in the configuration of a touch panel. The touch panel may include the conductive laminate as an electrode plate for a touch panel, for example. Further, the above-described pattern electrode can function as a touch sensor. The touch panel may have a known structure including an electrostatic capacity type or a resistance film type as long as the touch panel includes the conductive laminated body. The conductive laminate can be used for forming various devices such as a liquid crystal display as well as a touch panel.

The conductive laminate of the present application can effectively suppress the generation of bubbles in the periphery of the step and improve the adhesion to the ITO surface even when attached to a substrate having a surface step difference so that the appearance and performance of the product to which the conductive laminate is applied can be maintained . Such a conductive laminate can be usefully used, for example, in touch panels and the like.

1 is a schematic view of a conductive laminate according to the first embodiment of the present application.
2 is a schematic view of the conductive laminate of the second embodiment of the present application.

Hereinafter, the present application will be described in more detail by way of examples according to the present application and comparative examples not complying with the present application, but the scope of the present application is not limited by the following embodiments.

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

1. Evaluation of storage elastic modulus and loss elastic modulus

The pressure-sensitive adhesive composition prepared in Examples and Comparative Examples was coated between release films and cut to a size of 15 cm x 25 cm. The release film on one side was removed and laminated five times to have a thickness of about 1 mm . Subsequently, the laminate was cut into a circular shape having a diameter of 8 mm, compressed using glass, and allowed to stand overnight to improve wetting at the interface between the respective layers, To prepare a sample. Next, the sample was placed on a parallel plate, the gap was adjusted, the zero point of Normal & Torque was set, the normal force was stabilized, and then the storage elastic modulus and the loss elastic modulus were measured.

<Measurement apparatus and measurement conditions>

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

Measuring conditions:

geometry: 8 mm parallel plate

Thickness: about 1 mm

Test type: dynamic strain frequency sweep

Strain = 10.0 [%], Temperature: 50 [deg.] C

Initial frequency: 0.1 rad / s, Final frequency: 1 rad / s

2. Adhesion evaluation

A PET film having the pressure-sensitive adhesive layer prepared in Examples and Comparative Examples was cut to a width of 25 mm and a length of 100 mm to prepare a test piece. Then, a PET film having a pressure-sensitive adhesive layer formed thereon is attached to the ITO layer using a roller of 2 kg in accordance with JIS Z 0237. The ITO layer with the PET film on which the pressure-sensitive adhesive layer is formed is pressed for 20 minutes in an autoclave (50 ° C, 5 atmospheres), and then kept in a constant temperature and humidity chamber (23 ° C, 50% relative humidity) for about 24 hours. Then, using the equipment (Texture Analyzer, manufactured by Stable Microsystems, UK), the adhesion of the PET film with the pressure-sensitive adhesive layer formed thereon was peeled off from the ITO layer at a peeling speed of 300 mm / min and a peeling angle of 180 degrees.

3. Step  Evaluation of characteristics (1)

A transparent conductive laminate having an ITO layer (transversal length = 10 cm x 10 cm thickness: 20 nm) formed in a usual manner on a PET film (width x length = 10 cm x 10 cm thickness: ° C oven for about 1 hour, Ag paste (transversal length = 1 cm x 10 cm, thickness: 18 m) was applied on the ITO layer of the heat-treated transparent conductive laminate, For about 30 minutes. Next, the pressure-sensitive adhesive layer of the conductive laminate produced in Examples and Comparative Examples was applied so as to be in contact with the surface of the transparent conductive laminate on which the Ag paste was formed, and then bubbles were observed on the periphery of the step through an optical microscope.

○: No air bubbles were visually confirmed.

B: Fine bubbles were visually observed.

X: Large bubbles were observed with the naked eye.

4. Step  Evaluation of characteristics (2)

Step Property Evaluation The specimen of the step (1) was subjected to autoclave treatment at a pressure of 6 kgf / cm ² at a temperature of 50 ° C for 30 minutes, and bubbles were observed on the periphery of the step through an optical microscope.

○: No air bubbles were visually confirmed.

B: Fine bubbles were visually observed.

X: Large bubbles were observed with the naked eye.

Manufacturing example . Preparation of acrylic polymer

80 parts by weight of 2-ethylhexyl acrylate (EHA), 10 parts by weight of methyl acrylate (MA) and 2 parts by weight of 2-hydroxyethyl (meth) acrylate were added to a 1 L reactor equipped with a cooling device, Acrylate (HEA) were added thereto. Subsequently, 100 parts by weight of ethyl acetate (EAc) was poured into a solvent, and nitrogen gas was purged for 60 minutes to remove oxygen. Then, while maintaining the temperature at 60 占 폚, azobisisobutyronitrile (AIBN) were added to initiate the reaction. Thereafter, the reaction product was reacted for about 5 hours and diluted with ethyl acetate (EAc) to prepare an acrylic polymer.

Example  One

Preparation of pressure-sensitive adhesive composition

0.25 parts by weight of "Takenate D110N" (xylene diisocyanate) (cross-linking agent: Mitsui Chemical Co., Ltd.) as a crosslinking agent and Terpene series "DERTOPHENE T115" By weight to prepare a pressure-sensitive adhesive composition.

Conductivity Of the laminate  Produce

On one side of the PET film, the pressure-sensitive adhesive composition was releasably treated with silicone, and the pressure-sensitive adhesive composition thus prepared was coated and cured to a thickness of about 25 탆 to form a pressure-sensitive adhesive layer. Thereafter, the pressure-sensitive adhesive layer was transferred to the opposite surface of a PET film (thickness: about 25 mu m) having an ITO layer formed on one surface thereof in a usual manner, and the PET film thus treated was peeled off to produce a conductive laminate.

Example  2

The pressure-sensitive adhesive composition and the conductive laminate were prepared in the same manner as in Example 1, except that 20 parts by weight of the tackifier contained in the pressure-sensitive adhesive composition of Example 1 was added to 100 parts by weight of the acrylic polymer solid prepared in Preparation Example 1, .

Example  3

The pressure-sensitive adhesive composition and the conductive laminate were prepared in the same manner as in Example 1, except that 30 parts by weight of the tackifier contained in the pressure-sensitive adhesive composition of Example 1 was added to 100 parts by weight of the acrylic polymer solid prepared in Preparation Example 1, .

Comparative Example

A pressure-sensitive adhesive composition and a conductive laminate were prepared in the same manner as in Example 1, except that the pressure-sensitive adhesive composition contained in the pressure-sensitive adhesive composition of Example 1 was not included.

The physical properties and evaluation results of the above-mentioned Examples and Comparative Examples are shown in Table 1 below.

division Example 1 Example 2 Example 3 Comparative Example Storage modulus
(× 10 ⁴ )
(Unit: Pa) 1.5 1.3 1.3 1.7 Loss modulus
(× 10 ⁴ )
(Unit: Pa) 0.6 0.7 0.7 0.7 G '/ G " 2.5 1.85 1.85 2.42 Adhesion (ITO side) 1008.3 1442.5 1653.1 843.5 Step evaluation (1) △ △ △ × Evaluation of steps (2) ○ ○ ○ ×

As can be seen from the above Table 1, in the case of the conductive laminate of the present application, the ratio of the storage elastic modulus to the loss elastic modulus is increased by adding the tackifier within a specific range within the pressure sensitive adhesive layer, And the adhesion to the ITO surface can be improved.

101 and 102: First and second substrate layers
201 and 202: first and second conductive layers
2021: Step
30: pressure-sensitive adhesive layer
H: step thickness
A: step periphery

Claims (19)

A first base layer;
A first conductive layer formed on one surface of the first base layer; And
And a pressure-sensitive adhesive layer adhered to a surface of the first base layer where the first conductive layer is not formed, wherein the pressure-sensitive adhesive layer comprises a pressure-sensitive adhesive composition comprising an acrylic polymer and a tackifier, . The method according to claim 1,
Wherein the pressure-sensitive adhesive layer is a conductive laminate satisfying the following general formula (1)
[Formula 1]
1? G '/ G "? 5
G 'and G "denote the storage elastic modulus (G') and the loss elastic modulus (G") of the pressure-sensitive adhesive layer at a temperature of 50 ° C and a frequency of 1 rad / sec, respectively. The method according to claim 1,
The acrylic polymer includes alkyl (meth) acrylate as a polymerization unit. The method according to claim 1,
The acrylic polymer includes an alkyl (meth) acrylate having an alkyl group having 5 or more carbon atoms as a first monomer and an alkyl (meth) acrylate having an alkyl group having 1 to 4 carbon atoms as a second monomer as polymerized units. 5. The method of claim 4,
Wherein the first monomer is contained in an amount of 60 to 98 parts by weight based on 100 parts by weight of the acrylic polymer. 5. The method of claim 4,
And the second monomer is contained in an amount of 1 part by weight to 20 parts by weight based on 100 parts by weight of the acrylic polymer. The method according to claim 1,
Wherein the acrylic polymer further comprises, as a polymerization unit, a crosslinkable monomer which is a hydroxyl group-containing compound, a carboxyl group-containing compound, an epoxy group-containing compound or a nitrogen-containing functional group-containing compound. 8. The method of claim 7,
Wherein the crosslinkable monomer is contained in an amount of 1 part by weight to 20 parts by weight based on 100 parts by weight of the acrylic polymer. The method according to claim 1,
The tackifier may be a hydrocarbon resin or a hydrogenated product thereof; Rosin resin or hydrogenated product thereof; Rosin ester resins or hydrogenated products thereof; Terpene resins or hydrogenated products thereof; Terpene phenol resin or hydrogenated product thereof; And at least one selected from the group consisting of a polymerized rosin resin or a polymerized rosin ester resin. The method according to claim 1,
Wherein the tackifier is present in an amount ranging from 5 parts by weight to 100 parts by weight based on 100 parts by weight of the acrylic polymer. The method according to claim 1,
The pressure-sensitive adhesive composition may further comprise 0.001 to 10 parts by weight of a crosslinking agent relative to 100 parts by weight of the acrylic polymer The method according to claim 1,
Wherein the pressure-sensitive adhesive layer has an adhesive force of 900 gf / in or more to ITO (Indium Tin Oxide) measured at a peeling angle of 180 占 and a peeling speed of 0.3 m / min. The method according to claim 1,
The first substrate layer may be formed of a material such as glass, a polyethylene terephthalate film, a polytetrafluoroethylene film, a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polyvinyl chloride film, Wherein the conductive laminate is at least one selected from the group consisting of an ethylene-propylene copolymer film, an ethylene-ethyl acrylate copolymer film, an ethylene-methyl acrylate copolymer film and a polyimide film. The method according to claim 1,
Wherein the first conductive layer comprises gold, silver, platinum, palladium, copper, aluminum, nickel, chromium, titanium, iron, cobalt, tin, indium oxide, tin oxide, titanium oxide, cadmium oxide or copper iodide. The method according to claim 1,
And a second conductive layer formed on one surface of the second base layer and the second base layer and having a surface step difference, wherein the surface of the first base layer, on which the first conductive layer is not formed, Wherein the surface having the step of the adhesive layer is present in an attached state by the pressure-sensitive adhesive layer. 16. The method of claim 15,
Wherein the surface level difference of the second conductive layer is generated by further including a pattern electrode on one surface on which the second base layer is not formed. 17. The method of claim 16,
Wherein the pattern electrode is at least one selected from the group consisting of Ag, Al, Cu, Cr, Ni and Mo. 16. The method of claim 15,
Wherein the thickness of the pressure-sensitive adhesive layer is thicker than the thickness of the surface step difference by 2 占 퐉 or more. A touch panel comprising the conductive laminate of claim 1.

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