JP6466770B2 - Conductive laminate and touch panel using the same - Google Patents

Description

  The present invention relates to a conductive laminate and a touch panel using the same.

  In recent years, thiophene-based and aniline-based polymers have excellent stability and conductivity, and are expected to be used as organic conductive materials. As one of the applications, a coating composition in which a conductive polymer in which a dopant is added to the above polymer is dispersed in a solvent is used to form a transparent electrode used in various devices such as a liquid crystal display and a transparent touch panel. Yes.

  However, when the conductive polymer is used as a coating composition and a conductive film is formed on a substrate using the coating composition, it is under high temperature and high humidity (for example, a temperature of 85 ° C. and a relative humidity of 80%). In this case, it is necessary to suppress the temporal change of the electric resistance value of the conductive film.

  In addition, the conductive film used for the touch panel is sometimes used by bonding a conductive film patterned in the X-axis direction and a conductive film patterned in the Y-axis direction with an adhesive layer. If the conductive film is displaced at the time of alignment, the conductive film needs to be peeled off and bonded again, so that the conductive film is required to have so-called reworkability.

  For such a problem, for example, Patent Document 1 proposes a conductive laminate in which an adhesive layer containing an acidic component is brought into contact with a conductive layer containing a polythiophene-based conductive agent.

  On the other hand, Patent Document 2 proposes an antistatic polarizing film in which an antistatic coating composition containing a conductive polymer and an organic acid compound is applied between a polarizing film and an adhesive layer.

International publication number: WO2011 / 099474 Special table 2009-530657 gazette

  Patent Document 1 describes that it is possible to suppress the temporal change in the electrical resistance value of the conductive layer of the conductive laminate under high temperature and high humidity. However, reworkability of the obtained conductive laminate is not considered, and there is still room for improvement.

  On the other hand, Patent Document 2 describes the reworkability of the antistatic polarizing film, but it is considered to suppress the temporal change of the electric resistance value of the antistatic layer (conductive layer) under high temperature and high humidity. Absent. Further, in Patent Document 2, since the antistatic coating composition does not contain a binder, it is difficult to make the thickness of the coating film uniform when the composition is applied to a substrate. A conductive layer having a uniform electric resistance value cannot be formed due to the change of the above.

  The present invention has been made in order to solve the above problems, and has a small change over time in the electrical resistance value of the conductive layer of the conductive laminate under high temperature and high humidity, and has excellent reworkability. And a touch panel using the same.

The conductive laminate of the present invention is a conductive laminate including a substrate, a conductive layer disposed on at least one main surface of the substrate, and an adhesive layer disposed on the conductive layer. Te, the conductive layer comprises a conductive polymer, a binder, wherein the adhesive layer is observed containing an acid-free crosslinking resins, the acid-free crosslinking resins, as a monomer component, containing a hydroxyl group (meth) acrylic acid ester characterized by containing Mukoto.

  The touch panel of the present invention includes the conductive laminate of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the time-dependent change of the electrical resistance value of the conductive layer of the conductive laminated body under high temperature and high humidity is small, and the conductive laminated body excellent in rework property can be provided.

FIG. 1 is a schematic cross-sectional view showing an example of the conductive laminate of the present invention. FIG. 2 is a schematic cross-sectional view showing another example of the conductive laminate of the present invention.

(Conductive laminate of the present invention)
The transparent conductive laminate of the present invention comprises a substrate, a conductive layer disposed on at least one main surface of the substrate, and an adhesive layer disposed on the conductive layer, and the conductive layer comprises The conductive layer includes a conductive polymer and a binder, and the adhesive layer includes an acid-free crosslinked resin.

<Conductive layer>
When the conductive layer of the conductive laminate of the present invention contains a binder, it is possible to form a conductive layer having high hardness and high adhesion to the substrate as compared to a conductive layer made of only a conductive polymer. In addition, since the conductive layer includes a binder, a conductive layer having a small thickness variation can be formed on the base material, so that the electrical resistance value of the entire conductive layer can be made uniform. Furthermore, the conductive layer may be patterned, whereby a conductive layer suitable for touch panel use can be formed.

[Conductive polymer]
As the conductive polymer, any organic polymer having a main chain composed of a π-conjugated system can be used. For example, polypyrrole conductive polymer, polythiophene conductive polymer, polyacetylene conductive polymer, polyphenylene conductive polymer, polyphenylene vinylene conductive polymer, polyaniline conductive polymer, polyacene conductive high Examples thereof include molecules, polythiophene vinylene-based conductive polymers, and copolymers thereof. From the viewpoint of ease of polymerization and stability in air, polypyrrole conductive polymers, polythiophene conductive polymers, and polyaniline conductive polymers are preferred.

  Specific examples of the polypyrrole-based conductive polymer include polypyrrole, poly (N-methylpyrrole), poly (3-methylpyrrole), poly (3-ethylpyrrole), poly (3-n-propylpyrrole), poly (3-butylpyrrole), poly (3-octylpyrrole), poly (3-decylpyrrole), poly (3-dodecylpyrrole), poly (3,4-dimethylpyrrole), poly (3,4-dibutylpyrrole) , Poly (3-carboxypyrrole), poly (3-methyl-4-carboxypyrrole), poly (3-methyl-4-carboxyethylpyrrole), poly (3-methyl-4-carboxybutylpyrrole), poly (3 -Hydroxypyrrole), poly (3-methoxypyrrole), poly (3-ethoxypyrrole), poly (3-butoxypyrrole), poly 3-hexyloxy-pyrrole), poly (3-methyl-4-hexyloxy-pyrrole), poly (3-methyl-4-hexyloxy-pyrrole) and the like.

  Specific examples of the polythiophene-based conductive polymer include poly (thiophene), poly (3-methylthiophene), poly (3-ethylthiophene), poly (3-propylthiophene), poly (3-butylthiophene), Poly (3-hexylthiophene), poly (3-heptylthiophene), poly (3-octylthiophene), poly (3-decylthiophene), poly (3-dodecylthiophene), poly (3-octadecylthiophene), poly ( 3-bromothiophene), poly (3-chlorothiophene), poly (3-iodothiophene), poly (3-cyanothiophene), poly (3-phenylthiophene), poly (3,4-dimethylthiophene), poly ( 3,4-dibutylthiophene), poly (3-hydroxythiophene), poly (3-methoxythio) ), Poly (3-ethoxythiophene), poly (3-butoxythiophene), poly (3-hexyloxythiophene), poly (3-heptyloxythiophene), poly (3-octyloxythiophene), poly (3 -Decyloxythiophene), poly (3-dodecyloxythiophene), poly (3-octadecyloxythiophene), poly (3,4-dihydroxythiophene), poly (3,4-dimethoxythiophene), poly (3,4 Diethoxythiophene), poly (3,4-dipropoxythiophene), poly (3,4-dibutoxythiophene), poly (3,4-dihexyloxythiophene), poly (3,4-diheptyloxythiophene), Poly (3,4-dioctyloxythiophene), poly (3,4-didecyloxythiophene) ), Poly (3,4-didodecyloxythiophene), poly (3,4-ethylenedioxythiophene), poly (3,4-propylenedioxythiophene), poly (3,4-butenedioxythiophene), Poly (3-methyl-4-methoxythiophene), poly (3-methyl-4-ethoxythiophene), poly (3-carboxythiophene), poly (3-methyl-4-carboxythiophene), poly (3-methyl- 4-carboxyethylthiophene), poly (3-methyl-4-carboxybutylthiophene) and the like.

  Specific examples of the polyaniline-based conductive polymer include polyaniline, poly (2-methylaniline), poly (3-isobutylaniline), poly (2-anilinesulfonic acid), poly (3-anilinesulfonic acid) and the like. Can be mentioned.

  These may be used individually by 1 type and may use 2 or more types together. Among these, since transparency and conductivity are higher, polypyrrole, poly (3-methoxythiophene), poly (3,4-ethylenedioxythiophene), poly (2-anilinesulfonic acid), poly (3- The polymer which consists of 1 type or 2 types chosen from aniline sulfonic acid) is preferable.

In the present invention, a dopant can be used in combination in order to increase the electrical conductivity of the conductive polymer. Examples of the dopant include halogens such as iodine and chlorine, Lewis acids such as BF ₃ and PF ₅ , proton acids such as nitric acid and sulfuric acid, transition metals, alkali metals, amino acids, nucleic acids, surfactants, dyes, chloranil, Tetracyanoethylene, TCNQ, etc. can be used.

  In the present invention, it is preferable to use a polymer containing a polythiophene compound and a dopant as the conductive polymer, poly (3,4-ethylenedioxythiophene) is used as the polythiophene compound, and polystyrene sulfone is used as the dopant. Most preferably, a mixture using an acid (also referred to as PEDOT / PSS) is used.

  The blending ratio of the conductive polymer and the dopant is preferably conductive polymer: dopant = 1: 2 to 1: 4 in terms of mass ratio.

[Binder]
Examples of the binder include silicone-based inorganic binders formed by crosslinking alkoxysilane monomers, alkoxysilane oligomers, etc .; polyvinylidene fluoride resin (PVDF), vinylidene fluoride-acrylic copolymer, vinylidene fluoride-hexafluoropropylene copolymer Organic binder containing fluorine-based resin such as coalescence; organic binder containing polyvinyl alcohol resin, acrylic resin, polyester resin, polycarbonate resin, polyurethane resin, polystyrene resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl acetate resin, etc. Can be used. When the silicone inorganic binder is used, a conductive layer having a high hardness can be produced, and when an organic binder containing the fluorine resin is used, the water resistance and transparency of the conductive layer can be improved.

[Characteristics of conductive layer]
The surface electrical resistance value of the conductive layer is preferably 50Ω / sq or more and 10,000Ω / sq or less. Further, when the conductive layer is used as a touch panel electrode, the surface electrical resistance value of the conductive layer is preferably 50Ω / sq to 500Ω / sq, more preferably 50Ω / sq to 400Ω / sq. The smaller the surface electrical resistance value, the better the electrical characteristics.

  Although the thickness of the said conductive layer is suitably set according to a use, it is about 0.01-10 micrometers normally. If the conductive layer is too thin or too thick, it is difficult to form a uniform conductive layer. Depending on the proportion of the conductive polymer, when the thickness of the conductive layer is less than 0.01 μm, the surface electrical resistance value tends to increase or the variation in the surface electrical resistance value tends to increase. When the thickness of the conductive layer is greater than 10 μm, the thickness of the conductive laminate becomes too large and the total light transmittance tends to decrease.

  The variation of the surface electrical resistance value of the conductive layer depending on the location is preferably within ± 10%, more preferably within ± 5%. When the variation in the surface electrical resistance value of the conductive layer exceeds ± 10%, it becomes difficult to use the conductive layer as a touch panel electrode.

The variation S P1 of the surface electrical resistance value of the conductive layer at the location _P1 is represented by the following formula (1), where R _{A is} the average value of the surface electrical resistance values of all the measurement locations and R _P1 is the surface electrical resistance value of the location P1. Calculate with
S _P1 (%) = (| R _A −R _P1 | / R _A ) × 100 (1)

  The volume ratio between the conductive polymer and the binder can be 1:99 to 70:30. When the volume ratio between the conductive polymer and the binder is within the above range, the electrical characteristics, optical characteristics, physical characteristics, and wet heat resistance of the conductive layer can be improved. In particular, when the conductive layer is used as a touch panel electrode, a more preferable volume ratio of the conductive polymer and the binder is 5:95 to 45:55.

<Adhesive layer>
The pressure-sensitive adhesive layer of the conductive laminate of the present invention contains an acid-free crosslinked resin as a pressure-sensitive adhesive. Thereby, the time-dependent change of the electrical resistance value of the conductive layer under high temperature and high humidity can be suppressed, and a conductive laminate excellent in reworkability can be formed.

[Acid-free cross-linked resin]
In the present invention, the acid-free cross-linked resin refers to a cross-linked polymer obtained by further polymerizing an acid-free polymer formed by polymerizing a monomer not containing an acidic group such as a carboxyl group, a sulfonic acid group, and a phosphoric acid group with a cross-linking agent. The monomer not containing an acidic group contains a functional group such as a hydroxyl group or an amino group in order to perform a crosslinking reaction with a crosslinking agent. However, the acid-free cross-linked resin means that the resin does not have an acidic group intentionally, does not mean that no acidic group is detected, and is inevitable in the production process of the conductive laminate of the present invention. A trace amount of acid mixed in is meant to be acceptable.

  In the acid-free crosslinked resin, an acid-free polymer containing a polar group such as a hydroxyl group or an amino group is formed by reacting with a crosslinking agent, so that the acid-free crosslinked resin ultimately has a reduced number of polar groups. The adhesive layer becomes hydrophobic. Therefore, it is possible to suppress water from entering the conductive layer through the adhesive layer, and to reduce the influence of water on the conductive polymer having low water resistance in the conductive layer, so that the electric resistance of the conductive layer under high temperature and high humidity It is possible to suppress the change of the value with time. In addition, since the number of polar groups of the acid-free cross-linked resin in the adhesive layer is reduced, the adhesive force of the adhesive layer to the adherend becomes appropriate, and the reworkability of the conductive laminate can be improved. So-called adhesive residue when the laminate is peeled off can be reduced.

  Further, when only an acid-free polymer is used as the pressure-sensitive adhesive, the pressure-sensitive adhesive layer becomes hydrophilic because the pressure-sensitive adhesive layer is formed of a resin containing a large number of polar groups that are not crosslinked. For this reason, it becomes impossible to prevent water from entering the conductive layer through the adhesive layer, and the influence of water on the conductive polymer having low water resistance in the conductive layer becomes large. The resistance value changes with time. In addition, since the number of polar groups of the resin in the adhesive layer is large, the adhesive force of the adhesive layer to the adherend increases, so that the reworkability of the conductive laminate is lowered, so-called when the conductive laminate is peeled off. Increases adhesive residue.

  Furthermore, when a cross-linked resin containing an acidic group is used as the pressure-sensitive adhesive, the number of acidic groups in the resin in the pressure-sensitive adhesive is reduced by the cross-linking reaction, but acidic groups such as carboxyl groups have other polarities such as hydroxyl groups. Since the hydrophilicity is higher than that of the group, the remaining acidic group tends to make the pressure-sensitive adhesive layer hydrophilic, and the pressure-sensitive adhesive force of the pressure-sensitive adhesive layer becomes relatively large. Therefore, for the same reason as described above, the change over time in the electrical resistance value of the conductive layer under high temperature and high humidity increases, the reworkability of the conductive laminate decreases, and the so-called glue when the conductive laminate is peeled off. The rest will increase.

  As the acid-free polymer having a functional group other than the acidic group used for forming the acid-free crosslinked resin, for example, at least one of acrylic resin, urethane resin, rubber resin, silicone resin, and the like can be used. .

  The acrylic resin is not particularly limited as long as it has a functional group other than an acidic group. For example, (meth) acrylic acid alkyl ester in which the alkyl group usually has 2 to 18 carbon atoms. A functional group-containing (meth) acrylic acid polymer obtained by copolymerizing a functional group-containing monomer and another modifying monomer that can be copolymerized therewith, if necessary, can be used. Among these, a functional group-containing (meth) acrylic acid polymer having 6 or more carbon atoms in the alkyl group is preferable. In this specification, “(meth) acrylic acid” means both acrylic acid and methacrylic acid.

  Examples of the urethane resin include polyether urethane resin, non-yellowing polyether urethane resin, aromatic isocyanate / ether urethane resin, polyester urethane resin, non-yellowing polyester urethane resin, aromatic isocyanate / Examples thereof include ester urethane resins, polyether / polyester urethane resins, and non-yellowing polyether / polyester urethane resins.

  Examples of the rubber resin include chloroprene rubber (CR), isoprene rubber (IR), butyl rubber (IIR), nitrile-butadiene rubber (NBR), natural rubber, styrene-butadiene copolymer rubber (SBR), butadiene rubber ( BR), urethane rubber, fluororubber, acrylic rubber, ethylene-propylene copolymer rubber, ethylene-propylene-diene copolymer rubber, urethane rubber, silicone rubber and the like.

  Examples of the silicone resin include methyl silicone resin, methylphenyl silicone resin, and organic resin-modified silicone resin modified with epoxy resin, alkyd resin, polyester resin, and the like.

  As the acid-free polymer, a resin containing a hydroxyl group is preferable. For example, when a resin having an amino group is used as the acid-free polymer, if the conductive polymer is acidic, the amino group of the adhesive may react with the conductive polymer. This is because the conductivity may decrease.

  The monomer component of the acid-free polymer is preferably a (meth) acrylic acid ester containing a hydroxyl group. By using the (meth) acrylic acid ester containing a hydroxyl group as a monomer component of the acid-free polymer, the transparency of the adhesive layer can be maintained, and the hydroxyl group of the (meth) acrylic acid ester reacts with a crosslinking agent. The adhesive strength of the adhesive layer can be set within an appropriate range.

  The crosslinking agent for forming the acid-free crosslinking resin is not particularly limited. For example, an epoxy crosslinking agent, an isocyanate crosslinking agent, an imine crosslinking agent, a metal chelate crosslinking agent, and a melamine crosslinking agent. An agent or the like can be used. Among these, it is preferable to use an epoxy-based crosslinking agent, an isocyanate-based crosslinking agent, and a metal chelate-based crosslinking agent. By using an epoxy-based crosslinking agent, an isocyanate-based crosslinking agent, and a metal chelate-based crosslinking agent, crosslinking of an acid-free polymer having a functional group other than an acidic group proceeds even under relatively low temperature conditions such as room temperature. It is.

  Examples of the epoxy crosslinking agent include bisphenol A / epichlorohydrin type epoxy resin, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6-hexanediol diglycidyl ether, Methylolpropane triglycidyl ether, sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl erythritol, diglycerol polyglycidyl ether, and the like can be used.

  As said isocyanate type crosslinking agent, well-known aromatic polyisocyanate, aliphatic polyisocyanate, araliphatic polyisocyanate, alicyclic polyisocyanate, etc. can be used.

  As the metal chelate crosslinking agent, an aluminum chelate compound having Al as a central metal and a zirconium chelate compound having Zr as a central metal can be used.

  The amount of the crosslinking agent added to the acid-free polymer varies depending on the type of the acid-free polymer, but is, for example, in the range of 0.01 to 10 parts by mass with respect to 100 parts by mass of the acid-free polymer, preferably Can be in the range of 0.1 to 1 part by mass.

  When the addition amount of the crosslinking agent is excessively small, the adhesive strength of the adhesive layer increases and the cohesive strength of the adhesive layer cannot be improved, and so-called adhesive residue is increased when the conductive laminate is peeled off. . Moreover, when the addition amount of the crosslinking agent is excessively large, problems such as changes in physical properties due to unreacted crosslinking agent and contamination of the adherend may occur.

[Other ingredients]
In order to control the adhesive strength, a tackifier may be added to the adhesive layer as necessary. The tackifier is not particularly limited as long as it does not contain an acid group, and examples thereof include terpene resins, terpene phenol resins, synthetic petroleum resins, and hydrogenated resins thereof that do not contain an acid group. .

[Characteristics of adhesive layer]
The adhesive strength of the adhesive layer to the glass plate is preferably 1.5 N / 10 mm or more, and more preferably 4.0 N / 10 mm or more. Here, in this Embodiment, the adhesive force with respect to a glass plate means 180 degree peeling adhesive force with respect to the glass plate measured by the method similar to the adhesive force test prescribed | regulated to JISZ0237 (2009).

  When the adhesive strength of the adhesive layer to the glass plate is less than 1.5 N / 10 mm, when pasted to a transparent panel of a display device such as the conductive laminate of the present invention, a liquid crystal display device or an organic EL display device In addition, the conductive laminate of the present invention may be peeled off or displaced. Moreover, it is preferable that the adhesive force with respect to the glass plate of the said adhesion layer is 8 N / 10mm or less. When the adhesive force of the adhesive layer to the glass plate is excessively large, the reworkability of the conductive laminate of the present invention may be reduced. In this case, when the transparent panel is reused, an adhesive residue may occur when the conductive laminate of the present invention is peeled off.

  The thickness of the adhesive layer is preferably 5 μm or more and 200 μm or less, and more preferably 8 μm or more and 100 μm or less. When the thickness of the pressure-sensitive adhesive layer is less than 5 μm, necessary adhesive strength may not be obtained. When the thickness of the pressure-sensitive adhesive layer is greater than 200 μm, the total light transmittance tends to be low.

<Base material>
Although it does not specifically limit as a base material used for the electroconductive laminated body of this invention, The transparent base material which has transparency is preferable. As the material for the transparent substrate, for example, various materials such as resin, rubber, glass and ceramics can be used.

<Extraction electrode>
The conductive laminate of the present invention can further include a lead electrode between the conductive layer and the adhesive layer. As the material for the extraction electrode, a metal paste such as a highly conductive silver paste or a metal material such as aluminum or molybdenum is suitable, but is not limited thereto. In addition, as a method for forming the extraction electrode, a known method such as a printing method using the metal paste or a sputtering method using the metal material can be appropriately used.

<Conductive laminate>
The total light transmittance of the conductive laminate of the present invention is preferably 83% or more, and more preferably 90% or more. Further, the haze of the conductive laminate is preferably 2.0% or less, and more preferably 1.5% or less. The higher the total light transmittance and haze, the better the optical properties. The total light transmittance and the haze can be measured with a spectrophotometer such as “V-570” manufactured by JASCO Corporation.

  Next, the conductive laminate of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing an example of the conductive laminate of the present invention. In FIG. 1, the conductive laminate 10 includes a base material 11, a conductive layer 12 that is patterned and disposed on the base material 11, and an adhesive layer 13 that is disposed on the conductive layer 12. . In FIG. 1, the patterning portion of the conductive layer 12 is omitted. Further, as described above, the conductive layer 12 includes a conductive polymer and a binder, and the adhesive layer 13 includes an acid-free cross-linked resin.

  FIG. 2 is a schematic cross-sectional view of a conductive laminate showing another example of the conductive laminate of the present invention. In FIG. 2, the conductive laminate 20 includes a base material 21, a conductive layer 22 patterned and disposed on the base material 21, an extraction electrode 24 disposed on the conductive layer 22, and an extraction electrode. 24 and an adhesive layer 23 disposed on 24. In FIG. 2, the patterning portion of the conductive layer 22 is omitted. As described above, the conductive layer 22 includes a conductive polymer and a binder, and the adhesive layer 23 includes an acid-free cross-linked resin.

(Touch panel of the present invention)
The touch panel of the present invention includes the conductive laminate of the present invention. Since the touch panel provided with the conductive laminate of the present invention uses an acid-free crosslinked resin as a component of the adhesive layer of the conductive laminate, the touch panel is in contact with the adhesive layer as compared with the adhesive layer containing an acidic component. It is difficult to cause deterioration of the lead wiring (metal). Moreover, in the adhesive layer containing an acidic component, there is a problem that the acid component affects the lead-out wiring (metal) and the like, the electrical resistance value changes, and the sensitivity of the touch panel changes over time. The touch panel of the present invention provided with the conductive laminate used does not have such a problem, and can provide a touch panel whose sensitivity does not change even when used for a long time.

(Method for producing conductive laminate of the present invention)
The method for producing a conductive laminate of the present invention comprises a step of producing a conductive layer forming paint containing a conductive polymer, a binder, and a solvent, and applying the conductive layer forming paint on a substrate. And drying, a step of forming a conductive layer on the substrate and a step of forming or arranging an adhesive layer containing an acid-free crosslinked resin on the conductive layer can be provided.

  Further, the method for producing a conductive laminate of the present invention includes a step of forming a resist film at a position where a conductive pattern is formed on the conductive layer, and an inert agent that deactivates the conductivity. And a step of patterning the conductive layer by deactivating the conductivity of the exposed portion of the conductive layer.

  Furthermore, the method for producing a conductive laminate according to the present invention can include a step of forming a lead electrode between the conductive layer and the adhesive layer.

<Paint for forming conductive layer>
Examples of the conductive polymer used for the conductive layer forming coating include a mixture (PEDOT / PSS) containing poly (3,4-ethylenedioxythiophene) as the polythiophene compound and polystyrene sulfonic acid as a dopant. Can be used.

  Content of the said conductive polymer in the said coating material for conductive layer formation is 0.7 mass% or more and 70.0 mass% or less with respect to the mass of the total solid component contained in the said coating material for conductive layer formation. preferable. When the content of the conductive polymer is less than 0.7% by mass with respect to the mass of all solid components contained in the conductive layer forming coating material, the conductivity of the conductive layer is decreased, and 70.0% by mass is obtained. If it exceeds, the physical properties and wet heat resistance of the conductive layer tend to be lowered.

  As the binder used for the conductive layer-forming coating material, the above-described silicone-based inorganic binder, an organic binder containing a fluorine-based resin, or the like can be used.

  As the fluororesin, polyvinylidene fluoride (PVDF) is preferable. PVDF plays a role as a binder, thereby improving the adhesion between the conductive layer and the substrate. PVDF is uniformly dispersed in the conductive layer formed using the conductive layer forming paint to improve translucency, so that the dispersed particle size of PVDF in the conductive layer forming paint is 0.3 μm or less. It is preferable to set to.

  In addition to PVDF, the organic binder includes vinylidene fluoride-acrylic copolymer, vinylidene fluoride-hexafluoropropylene copolymer, hydroxyethyl cellulose, polyvinyl alcohol, polyethylene oxide, silane compound, polyester emulsion, polyolefin emulsion, and the like. Resin may be included.

  The content of the binder is preferably 30.0% by mass or more and 99.3% by mass or less, more preferably 55% by mass or more and 95.0% by mass with respect to the mass of all solid components contained in the conductive layer forming coating material. % Or less. When the content of the binder is too small, a conductive layer having sufficient hardness tends to be difficult to obtain, and when the content of the binder is too large, the conductive layer becomes cloudy and optical characteristics tend to deteriorate.

  The solvent used for the conductive layer-forming coating material preferably contains a protic polar solvent and an aprotic polar solvent. By using a protic polar solvent and an aprotic polar solvent in combination, a transparent conductive film excellent in transparency can be obtained at a relatively low drying temperature.

  Examples of the protic polar solvent include water, ethyl alcohol, methyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, ethylene glycol, propylene glycol, acetic acid, and the like. Examples of the polar solvent include dimethyl sulfoxide, N-methylpyrrolidone, N-ethylpyrrolidone, N, N-dimethylformamide, acetonitrile, acetone, tetrahydrofuran and the like.

  The content of the aprotic polar solvent is preferably 1.0% by mass or more and 50.0% by mass or less with respect to the total mass of the solvent. If the content of the aprotic polar solvent is less than 1.0% by mass with respect to the total mass of the solvent, the optical properties of the conductive layer tend to deteriorate, and if it exceeds 50.0% by mass, There exists a tendency for heat-and-moisture resistance to fall.

  Although content of the said solvent is not specifically limited, What is necessary is just to be 50.0 mass% or more and 99.5 mass% or less with respect to the total mass of the said coating material for conductive layer formation. The solvent may contain a nonpolar solvent.

<Formation of conductive layer>
Examples of the method for applying the conductive layer-forming coating material on a substrate include a bar coating method, a reverse method, a gravure coating method, a micro gravure coating method, a die coating method, a dipping method, a spin coating method, a slit coating method, A coating method such as a spray coating method can be used.

  The heating after the application may be performed under the condition that the solvent component of the conductive layer-forming coating material evaporates, and is preferably performed at 100 to 150 ° C. for 5 to 60 minutes. If the solvent remains in the conductive layer, the strength tends to be inferior. As the heating method, for example, a hot air drying method, a heating drying method, a vacuum drying method, natural drying, or the like can be used. Further, if necessary, the transparent conductive film may be formed by irradiating the coating film with UV light or EB light to cure the coating film.

<Process for forming conductive pattern>
The resist film formed at the position where the conductive pattern on the conductive layer is formed can be formed, for example, by screen printing a resist agent on the conductive layer. The said resist agent is not specifically limited, It can select suitably.

  As an inert agent used in order to deactivate the electroconductivity of the exposed part of the said conductive layer, what is necessary is just to be able to deactivate the said conductive polymer, For example, an oxidizing compound and a basic compound are mentioned.

  Examples of the oxidizing compound include hydrogen peroxide compounds, perchloric acid compounds, hypochlorous acid compounds, peracetic acid compounds, metachlorobenzoic acid compounds, sulfite compounds, and the like.

  Examples of the basic compound include ammonia, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, pyridine, 4-methylpyridine, and tetramethylammonium hydroxide.

  In the step of forming the conductive pattern, since the conductive layer contains a binder, the inert agent hardly penetrates into the conductive layer. For this reason, since the inactive agent gradually penetrates into the conductive layer, a conductive pattern can be formed with high accuracy.

<Formation of adhesive layer>
In order to form an adhesive layer on the conductive layer, an adhesive layer-forming coating material containing the acid-free polymer, a crosslinking agent, and a solvent may be applied and dried. The method for applying and drying the adhesive layer-forming coating material on the conductive layer is not particularly limited, and various coating devices and drying devices can be used. The solvent is not particularly limited as long as it can mix the acid-free polymer and the crosslinking agent.

  Further, in order to dispose the adhesive layer on the conductive layer, the adhesive layer is separately formed on the separator using the adhesive layer forming coating material, and the separately formed adhesive layer is pasted on the conductive layer. What is necessary is just to arrange | position by attaching.

  Hereinafter, the present invention will be described in detail using examples. However, the present invention is not limited to the following examples. Unless otherwise indicated, in the following, “part” means “part by mass”.

Example 1
<Preparation of adhesive layer forming coating>
100 parts of acrylic pressure-sensitive adhesive (trade name “Cybinol TPO3232”, solid content concentration: 35 mass%, hydroxyl value: 2.7 mg / g, weight average molecular weight Mw: 500,000), an acid-free polymer On the other hand, 0.8 parts of zirconium chelate compound (made by Matsumoto Fine Chemical Co., Ltd., trade name “Orga Tix ZC700”, solid content concentration: 20% by mass), which is a metal chelate crosslinking agent, is added and mixed with isopropyl alcohol and toluene. Dilution was carried out using a solvent (volume mixing ratio = 1: 1) so that the solid content concentration was 23% by mass to obtain a coating material a for forming an adhesive layer.

<Preparation of paint for forming conductive layer>
The following components were added and mixed to prepare a conductive layer forming coating material A.
(1) Conductive polymer dispersion (manufactured by Heraeus, trade name “PH1000”, conductive polymer: PEDOT-PSS, solid content concentration: 1.0 mass%, solvent: water): 46.0 parts (2 ) Binder resin (acrylic resin, solid content concentration: 30.0% by mass, solvent: water): 4.6 parts (3) Protic polar solvent (ethyl alcohol): 12.0 parts (4) Aprotic polar solvent (Ethylene glycol): 36.0 parts (5) Water: 1.4 parts

<Formation of conductive sheet>
Next, a PET film (total light transmittance: 92.0%) having a thickness of 100 μm was used as a substrate, and the conductive layer forming coating material A was applied to one main surface of the substrate using a bar coater. Heat at 5 ° C. for 5 minutes. Thereby, the electroconductive film of Example 1 in which the electroconductive layer was formed in one main surface was produced. The thickness of the conductive layer was 0.3 μm.

<Formation of resist film>
A resist agent (product name “Clvious SET S”, manufactured by Heraeus Co., Ltd.) is printed on the 5 cm square region of the central portion of the main surface on the conductive layer side of the conductive film, and then heated at 100 ° C. for 5 minutes. did. Thereby, a resist film was formed on the conductive layer.

<Decrease in conductivity>
Next, after immersing the conductive film having a resist film formed on the conductive layer in a solution prepared by preparing a 10% aqueous solution of a chlorine-based inert agent (trade name “Clvious Etch”, manufactured by Heraeus) for 20 minutes, Washed with distilled water and heated at 100 ° C. for 5 minutes. Thereby, the conductivity of the exposed portion of the conductive layer was lowered.

<Removal of resist film>
Next, the conductive film is immersed in toluene for 3 minutes, the resist film is peeled off, washed with distilled water, and dried at 100 ° C. for 5 minutes to produce a conductive film provided with a patterned conductive layer. did.

<Measurement of variation in surface electrical resistance value of conductive layer>
Using the above-described formula (1): S _P1 (%) = (| R _A −R _P1 | / R _A ) × 100, variations in the surface electric resistance values at 10 points on the conductive layer were measured. As a result of the above measurement, when the variation of the surface electrical resistance value of the conductive layer is within ± 10% for all 10 points, it is judged as good, and the variation of the surface electrical resistance value of the conductive layer exceeds ± 10% even at one point. It was judged as bad.

<Measurement of change rate of surface electric resistance value of conductive layer>
First, the initial surface electrical resistance value of the conductive layer of the conductive film was measured using a resistivity measuring device “Loresta-GP” (MCP-T610 type) manufactured by Mitsubishi Chemical Analytech Co., Ltd. and an LSP probe.

Next, the conductive film was placed in a constant temperature and humidity chamber and stored at 85 ° C. and a relative humidity of 80% for 240 hours. Subsequently, the surface electrical resistance value of the conductive layer of the conductive film after storage was measured in the same manner as described above. Finally, the change rate of the surface electrical resistance value was calculated by the following formula (2).
Rate of change in surface electrical resistance value (%) = [(surface electrical resistance value after storage−initial surface electrical resistance value) / initial surface electrical resistance value] × 100 (2)

  As a result of the above measurement, when the rate of change of the surface electrical resistance value is less than 10%, it is determined that the electrical resistance value of the conductive layer of the electrically conductive laminate under high temperature and high humidity changes little with time, and the heat and moisture resistance is good, When the change rate of the surface electrical resistance value exceeded 10%, the heat and humidity resistance was judged to be poor.

<Formation of adhesive layer>
Example 1 The above-mentioned adhesive layer-forming coating material a was applied to the conductive layer side of the conductive film having the patterned conductive layer using a bar coater to form an adhesive layer on the conductive film. A conductive film with an adhesive layer (conductive laminate of the present invention) was obtained.

<Evaluation of reworkability>
Next, the adhesive layer side of the conductive film with an adhesive layer was bonded to a glass plate, and the adhesive strength was measured by peeling it 180 ° to the glass plate in the same manner as the adhesive strength test defined in JIS Z0237 (2009). . Moreover, the adhesive residue of the glass plate after peeling was observed visually. As a result, when there was no adhesive residue, the reworkability was judged to be good, and when adhesive residue was observed, the reworkability was judged to be poor.

(Example 2)
<Preparation of adhesive layer forming coating>
Acrylic pressure-sensitive adhesive which is an acid-free polymer (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name “Cooponyl N-7520”, solid content concentration: 35 mass%, hydroxyl value: 50.0 mg / g, weight average molecular weight Mw: 70) 10,000 parts of titanium chelate compound (manufactured by Matsumoto Fine Chemical Co., Ltd., trade name “Orgatechs TC1040”, solid content concentration: 75% by mass) is added to 100 parts by weight, and methyl ethyl ketone and Dilution was carried out using a mixed solvent with toluene (volume mixing ratio = 1: 1) so that the solid content concentration became 23% by mass to obtain a coating material b for forming an adhesive layer.

<Preparation of paint for forming conductive layer>
The following components were added and mixed to prepare a conductive layer forming coating material B.
(1) Conductive polymer dispersion (manufactured by Heraeus, trade name “PH1000”, conductive polymer: PEDOT-PSS, solid content concentration: 1.0 mass%, solvent: water): 46.0 parts (2 ) Binder resin dispersion (PVDF dispersion, average dispersion particle size of PVDF particles: 0.2 μm, solid content concentration: 35 mass%, solvent: water): 3.9 parts (3) Protic polar solvent (ethyl alcohol) : 12.0 parts (4) Aprotic polar solvent (ethylene glycol): 36.0 parts (5) Water: 2.1 parts

  A conductive film with an adhesive layer of Example 2 was prepared in the same manner as in Example 1 except that the adhesive layer-forming paint b and the conductive layer-forming paint B were used. Measurement of variation and change rate of surface electric resistance value of conductive layer, measurement of adhesive strength and evaluation of reworkability were performed.

(Example 3)
<Preparation of adhesive layer forming coating>
Acrylic pressure-sensitive adhesive which is an acid-free polymer (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name “Cooponyl N-7520”, solid content concentration: 35 mass%, hydroxyl value: 50.0 mg / g, weight average molecular weight Mw: 70) To 100 parts by weight, 0.5 part of an isocyanate-based crosslinking agent (trade name “Coronate HX” manufactured by Nippon Polyurethane Industry Co., Ltd., solid content concentration: 100% by mass) is added, and a mixed solvent of methyl ethyl ketone and toluene ( The mixture was diluted so that the solid content concentration became 23% by mass using a volume mixing ratio = 1: 1) to obtain a coating material c for forming an adhesive layer.

  A conductive film with an adhesive layer of Example 3 was produced in the same manner as in Example 1 except that the adhesive layer-forming paint c and the conductive layer-forming paint B produced in Example 2 were used. In the same manner as described above, variation in the surface electrical resistance value of the conductive layer and measurement of the rate of change, measurement of adhesive strength, and evaluation of reworkability were performed.

(Comparative Example 1)
<Preparation of adhesive layer forming coating>
Epoxy-based cross-linking with respect to 100 parts of an acrylic pressure-sensitive adhesive that is an acidic group-containing polymer (manufactured by Soken Chemicals, trade name “SK-2094”, solid content concentration: 25 mass%, acid value: 6.8 mg / g) 0.27 parts of an agent (manufactured by Soken Chemical Co., Ltd., trade name “E-AX”, solid content concentration: 5% by mass) was added, diluted with toluene to a solid content concentration of 20% by mass, and adhered. A layer-forming paint d was obtained.

  A conductive film with an adhesive layer of Comparative Example 1 was produced in the same manner as in Example 1 except that the adhesive layer-forming paint d and the conductive layer-forming paint B produced in Example 2 were used. In the same manner as described above, variation in the surface electrical resistance value of the conductive layer and measurement of the rate of change, measurement of adhesive strength, and evaluation of reworkability were performed.

(Comparative Example 2)
A conductive layer-forming coating material C was prepared in the same manner as in Example 1 except that no binder resin was added. A conductive film with an adhesive layer of Comparative Example 2 was prepared in the same manner as in Example 1 except that the adhesive layer forming coating material a and the conductive layer forming coating material C prepared in Example 1 were used. In the same manner as described above, variation in the surface electrical resistance value of the conductive layer and measurement of the rate of change, measurement of adhesive strength, and evaluation of reworkability were performed.

  The results of Examples 1 to 3 and Comparative Examples 1 and 2 are shown in Table 1.

  From Table 1, it can be seen that in Examples 1 to 3 of the present invention, the rate of change and variation of the surface electrical resistance value are good and the reworkability is also good. On the other hand, Comparative Example 1 in which no acid-free crosslinked resin was used for the adhesive layer was inferior in the rate of change in surface electrical resistance and reworkability, and in Comparative Example 2 in which no binder was added to the conductive layer, the variation in surface electrical resistance was large. I understand that.

10, 20 Conductive laminate 11, 21 Base material 12, 22 Conductive layer 13, 23 Adhesive layer 24 Lead electrode

Claims (9)

A conductive laminate comprising a substrate, a conductive layer disposed on at least one main surface of the substrate, and an adhesive layer disposed on the conductive layer,
The conductive layer includes a conductive polymer and a binder,
The adhesive layer is observed containing an acid-free crosslinking resins,
The acid-free crosslinking resins, as a monomer component, containing a hydroxyl group (meth) conductive laminate according to claim containing Mukoto acrylic acid ester.   The conductive laminate according to claim 1, wherein the conductive layer is patterned.   The conductive laminate according to claim 1, further comprising an extraction electrode between the conductive layer and the adhesive layer.   The conductive laminate according to claim 1, wherein the conductive polymer includes a dopant.   The conductive laminate according to claim 1, wherein the conductive polymer includes a polythiophene compound and polystyrene sulfonic acid.   The conductive laminate according to claim 1, wherein the binder includes a fluorine-based resin. The thickness of the adhesive layer, electroconductive laminate according to any one of claims 1 to 6 at 5μm least 200μm or less. Total light transmittance is at 83% or more, haze, electroconductive laminate according to any one of claims 1 to 7 or less 2.0%. Touch panel characterized in that it comprises a conductive multilayer body according to any one of claims 1-8.

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