JP6584188B2 - Laminated body and method for producing the same - Google Patents

Description

  The present invention relates to a laminate and a method for producing the same.

  In recent years, display devices such as a liquid crystal display (LCD) and input devices using a touch panel or the like in combination with the display device have been widely used in various fields. As the touch panel, a capacitive touch panel is widely used, and the capacitive touch panel has a structure in which many members are laminated, and an adhesive layer is used for bonding the members. Is used. Examples of the capacitive touch panel include a capacitive touch panel having a laminated structure of cover glass / adhesive layer / transparent conductive layer / glass substrate.

  The transparent conductive layer is formed of a material having high transparency and conductivity, such as indium tin oxide (ITO). Since the transparent conductive layer usually has a high refractive index (around 1.9 with an ITO film), the transparent conductive layer generally has a refractive index of about 1.45 to 1.5. The reflectance may increase due to the difference in refractive index at the interface with the pressure-sensitive adhesive layer, and there is a problem that the visibility is poor. In addition, when the transparent conductive layer is patterned, a pattern opening that does not have a transparent conductive layer is formed by pasting on a patterned transparent conductive layer with another member such as a cover glass via an adhesive layer. In some cases, the pattern can be seen (pattern appearance) due to the difference in reflectance between the portion and the pattern portion having the transparent conductive layer.

  For such problems, for example, a transparent substrate, a hard coat layer having a specific refractive index, an undercoat layer having a specific refractive index, and a patterned transparent conductive layer are laminated in this order. A laminate is known (see, for example, Patent Document 1).

Japanese Patent No. 5683734

  Patent Document 1 discloses that the appearance of a pattern can be suppressed by disposing a hard coat layer or an undercoat layer having a specific refractive index between a transparent conductive layer and a transparent substrate. However, in patent document 1, the adhesive layer laminated | stacked on a transparent conductive layer is not fully examined, suppression of pattern appearance is not enough, and there was room for improvement.

  Therefore, an object of this invention is to provide the laminated body which can suppress the pattern appearance of a transparent conductive layer. Another object of the present invention is to provide a method for producing the laminate.

  As a result of intensive studies to solve the above problems, the present inventors have found that the object can be achieved by using the following laminate, and have completed the present invention.

That is, the present invention provides a transparent substrate, a first optical adjustment layer, a transparent conductor having a patterned transparent conductive layer in this order, and a laminate having a pressure-sensitive adhesive layer formed on the transparent conductive layer of the transparent conductor. Body,
The pressure-sensitive adhesive layer includes a base pressure-sensitive adhesive region essentially formed of the pressure-sensitive adhesive composition from one main surface of the pressure-sensitive adhesive layer to the thickness direction, and inorganic particles from the other main surface to the thickness direction. Having an inorganic particle-containing region,
The pressure-sensitive adhesive layer and the transparent conductor are laminated so that the inorganic particle-containing region of the pressure-sensitive adhesive layer and the transparent conductive layer of the transparent conductor are in contact with each other,
The present invention relates to a laminate having a metal element to carbon element ratio (metal element / carbon) contained in the inorganic particle-containing region of 0.01 to 0.2.

  The refractive index of the transparent substrate is preferably larger than the refractive index of the first optical adjustment layer and lower than the refractive index of the transparent conductive layer.

  A second optical adjustment layer having a refractive index higher than the refractive index of the first optical adjustment layer and lower than the refractive index of the transparent conductive layer is further provided between the first optical adjustment layer and the transparent substrate. Is preferred.

  The refractive index of the surface of the inorganic particle-containing region on the side in contact with the transparent conductive layer is preferably 1.47 to 1.74.

  It is preferable that the refractive index of the inorganic particle-containing region continuously decreases from the side in contact with the transparent conductive layer of the inorganic particle-containing region toward the other side of the inorganic particle-containing region.

  It is preferable that the inorganic particles include zirconia particles.

  The average thickness of the inorganic particle-containing region is preferably 20 nm to 600 nm.

  The transparent conductive layer preferably has a surface resistance value of 100Ω / □ or less.

Further, the present invention provides a step of preparing a transparent conductor having a transparent substrate, a first optical adjustment layer, and a transparent conductive layer in this order,
A dispersion containing inorganic particles is applied to one main surface of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition, and the inorganic particles contained in the dispersion are thickened from one main surface of the pressure-sensitive adhesive layer. Infiltrating in the direction to form a base pressure-sensitive adhesive region essentially formed by the pressure-sensitive adhesive composition, and an inorganic particle-containing region,
Bonding the pressure-sensitive adhesive layer and the transparent conductor so that the inorganic particle-containing region of the pressure-sensitive adhesive layer and the transparent conductive layer of the transparent conductor are in contact with each other;
It is related with the manufacturing method of the said laminated body characterized by the element ratio (metal element / carbon) of the metal element and carbon contained in the said inorganic particle containing area | region being 0.1-0.2.

  Since the laminate of the present invention has a specific inorganic particle-containing region on the side of the pressure-sensitive adhesive layer in contact with the transparent conductive layer, reflection at the interface between the pressure-sensitive adhesive layer and the transparent conductive layer can be suppressed, The pattern appearance of the transparent conductive layer can be suppressed. Moreover, this invention can provide the manufacturing method of the laminated body which can manufacture the laminated body which show | plays the said effect.

It is sectional drawing which shows typically one Embodiment of the laminated body of this invention. It is sectional drawing which shows typically one Embodiment of the laminated body of this invention. It is a one part enlarged view of the adhesive layer of FIG. It is the schematic which shows the formation process of the adhesive layer used by this invention.

1. Laminated body The laminated body of the present invention includes a transparent base material, a first optical adjustment layer and a patterned transparent conductive layer in this order, and a pressure-sensitive adhesive layer formed on the transparent conductive layer of the transparent conductor. Have
The pressure-sensitive adhesive layer includes a base pressure-sensitive adhesive region essentially formed of the pressure-sensitive adhesive composition from one main surface of the pressure-sensitive adhesive layer to the thickness direction, and inorganic particles from the other main surface to the thickness direction. Having an inorganic particle-containing region,
The pressure-sensitive adhesive layer and the transparent conductor are laminated so that the inorganic particle-containing region of the pressure-sensitive adhesive layer and the transparent conductive layer of the transparent conductor are in contact with each other,
The element ratio (metal element / carbon) of the metal element and carbon contained in the inorganic particle-containing region is 0.01 to 0.2.

  The configuration of the laminate of the present invention will be described in detail with reference to the drawings. In addition, the dimension of each structure in FIG. 1 shows the example, and this invention is not limited to this.

  As shown in FIG. 1, the laminate 1 of the present invention has a transparent conductor 5 and an adhesive layer 8. The transparent conductor 5 includes the transparent base material 2, the first optical adjustment layer 3, and the patterned transparent conductive layer 4 (hereinafter sometimes simply referred to as “transparent conductive layer 4”) in this order. The pressure-sensitive adhesive layer 8 includes a base pressure-sensitive adhesive region 7 that is essentially formed of the pressure-sensitive adhesive composition from one main surface of the pressure-sensitive adhesive layer 8 (the surface indicated by the arrow A in FIG. 1) to the thickness direction. And an inorganic particle-containing region 6 containing inorganic particles from the other main surface of the pressure-sensitive adhesive layer 8 (the surface indicated by the arrow B in FIG. 1) in the thickness direction. The pressure-sensitive adhesive layer 8 and the transparent conductor 5 are laminated so that the inorganic particle-containing region 6 of the pressure-sensitive adhesive layer 8 and the transparent conductive layer 4 of the transparent conductor 5 are in contact with each other.

  In this invention, since it has the specific inorganic particle containing area | region 6 in the side which contacts the transparent conductive layer 4 of the adhesive layer 8, it suppresses the reflection in the interface between the adhesive layer 8 and the transparent conductive layer 4. Can do. Hereinafter, each structure of the laminated body 1 of this invention is demonstrated in detail.

(1) Transparent conductor (1-1) Transparent base material As the transparent base material 2, what is necessary is just to have transparency, for example, a base material made of a resin film, glass or the like (for example, a sheet or film) A resin film is particularly preferable. The thickness of the transparent substrate 2 is not particularly limited, but is preferably about 10 μm to 200 μm, and more preferably about 15 μm to 150 μm.

  Although it does not restrict | limit especially as a material of the said resin film, Various plastic materials which have transparency are mentioned. For example, the materials include polyester resins such as polyethylene terephthalate and polyethylene naphthalate, acetate resins, polyethersulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth) acrylic resins. , Polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl alcohol resin, polyarylate resin, polyphenylene sulfide resin, and the like. Among these, polyester resins, polyimide resins and polyethersulfone resins are preferable.

  In addition, the transparent base material 2 is subjected to etching treatment such as plasma treatment, corona discharge, flame, ultraviolet ray irradiation, electron beam irradiation, chemical conversion, oxidation and undercoating treatment on the surface in advance, and an optical adjustment layer provided thereon You may make it improve the adhesiveness with respect to the said transparent base materials 2, such as. Further, before providing the optical adjustment layer or the like, dust may be removed and cleaned by solvent cleaning, ultrasonic cleaning, or the like, if necessary.

  The refractive index of the transparent substrate 2 is not particularly limited, and is usually about 1.45 to 1.75. Moreover, it is preferable from the point of suppression of the pattern visibility of a transparent conductive layer that the refractive index of the said transparent base material 2 is larger than the refractive index of the 1st optical adjustment layer 3 mentioned later, and lower than the refractive index of the transparent conductive layer 4.

(1-2) Optical Adjustment Layer The first optical adjustment layer 3 is preferably formed from one or more materials selected from the group consisting of organic substances and inorganic substances. For example, a mixture of an inorganic substance and an organic substance, or an organic substance alone Although it can be formed from an inorganic substance alone, it is preferably formed from an organic substance alone from the viewpoint of the patterning processability of the transparent conductive layer (the organic substance is easier to etch).

Examples of inorganic substances forming the first optical adjustment layer 3 include NaF, Na ₃ AlF ₆ , LiF, MgF ₂ , CaF ₂ , SiO ₂ , LaF ₃ , CeF ₃ , Al ₂ O ₃ , TiO ₂ , Nb ₂ O ₅ , Ta ₂ O ₅ , ZrO ₂ , ZnO, ZnS, SiO _x (x is 1.5 or more and less than 2) and the like can be mentioned. Among these, SiO ₂ , Al ₂ O ₃ , TiO ₂ , Nb ₂ O ₅ Inorganic oxides such as Ta ₂ O ₅ , ZrO ₂ , ZnO, and SiO _x (x is 1.5 or more and less than 2) are preferable, and SiO ₂ is more preferable. Moreover, as an organic substance which forms the 1st optical adjustment layer 3, an acrylic resin, a urethane resin, a melamine resin, an alkyd resin, an epoxy resin, a siloxane polymer etc. are mentioned. In particular, it is preferable to use a thermosetting resin made of a mixture of a melamine resin, an alkyd resin, and an organosilane condensate as the organic substance. The first optical adjustment layer 3 can be formed using the above materials by a coating method such as a gravure coating method or a bar coating method, a vacuum deposition method, a sputtering method, an ion plating method, or the like.

  When the first optical adjustment layer 3 is formed from a mixture of an inorganic substance and an organic substance, the mixing ratio is not particularly limited. For example, the content of the inorganic substance in the first optical adjustment layer 3 is an inorganic atom constituting the inorganic substance. And the atomic ratio of carbon atoms contained in the first optical adjustment layer 3. That is, the ratio of the number of inorganic atoms and the number of carbon atoms (inorganic atoms / carbon atoms) constituting the inorganic substance is preferably 0.15 or more, and more preferably 0.30 or more. Examples of the inorganic atoms constituting the inorganic substance include one or more atoms selected from the group consisting of Na, Al, Li, Mg, Ca, Si, La, Ce, Ti, Nb, Ta, Zr, and Zn. Among these, Si, Nb and the like are preferable, and Si is more preferable.

  The ratio (inorganic atom / carbon atom) represents the atomic ratio of the inorganic atom and the carbon atom contained in the first optical adjustment layer 3, and the laminate of the present invention is the second optical adjustment layer or other When the optical adjustment layer is included, the optical adjustment layer other than the first optical adjustment layer 3 can be appropriately adjusted with respect to the ratio (inorganic atom / carbon atom).

  For example, when an organic material containing an inorganic atom such as an organic silane condensate is used as a material constituting the first optical adjustment layer 3, the organic material may be used even if the optical adjustment layer does not contain an inorganic material. Inorganic atoms (Si in the case of organosilane condensate) are detected. However, the ratio of (inorganic atoms / carbon atoms) due to inorganic atoms derived from organic substances is usually as low as less than 0.15.

  The content of inorganic atoms constituting the inorganic substance in the first optical adjustment layer 3 can be obtained by measuring the depth profile of the element ratio by photoelectron spectroscopy analysis (ESCA). That is, the inorganic atoms contained in the first optical adjustment layer 3 are plotted with respect to the depth direction, and the ratio (inorganic atoms / carbon atoms) is maximized in the depth range corresponding to the first optical adjustment layer 3. Can be adopted.

  Although the thickness of the 1st optical adjustment layer 3 is not specifically limited, For example, it is preferable that they are 3 nm-200 nm, It is more preferable that they are 5 nm-150 nm, It is further more preferable that they are 10 nm-40 nm. . Since the thickness of the 1st optical adjustment layer 3 exists in the said range, since it becomes difficult to visually recognize the pattern of a transparent conductive layer, it is preferable.

  The first optical adjustment layer 3 may have nanoparticles. Although it does not specifically limit as a particle size of the said nanoparticle, For example, it is 1-200 nm, 10-80 nm is preferable and 20-40 nm is more preferable. If the particle size is less than 1 nm, the particles may not be uniformly dispersed in the optical adjustment layer. If the particle size is more than 200 nm, the surface may be uneven and the resistance value may be increased. Examples of the inorganic oxide forming the nano fine particles include fine particles of silicon oxide (silica), hollow nano silica, titanium oxide, aluminum oxide, zinc oxide, tin oxide, zirconium oxide, niobium oxide, and the like. Among these, fine particles of silicon oxide (silica), titanium oxide, aluminum oxide, zinc oxide, tin oxide, zirconium oxide, and niobium oxide are preferable. These may be used alone or in combination of two or more. The content of the nanoparticles in the first optical adjustment layer 3 is preferably 90% by weight or less, and more preferably 0.1 to 90% by weight. When the first optical adjustment layer 3 contains the nanoparticles, the presence of the nanoparticles can be confirmed from the difference in contrast when a cross-sectional image of a transmission electron microscope (TEM) is observed. In the case where the first optical adjustment layer 3 contains nanoparticles, the inorganic atoms derived from the nanoparticles are also subject to the “inorganic atoms” in the above ratio (inorganic atoms / carbon atoms).

  The first optical adjustment layer 3 may be disposed between the transparent substrate 2 and the transparent conductive layer 4.

  The refractive index of the first optical adjustment layer 3 is not particularly limited, but is preferably about 1.35 to 1.75, and more preferably about 1.40 to 1.55.

  In the present invention, as shown in FIG. 2, the refractive index of the transparent conductive layer 4 is higher than the refractive index of the first optical adjustment layer 3 between the first optical adjustment layer 3 and the transparent substrate 2. It is preferable from the viewpoint of optical characteristics to have the second optical adjustment layer 3 ′ having a refractive index lower than the refractive index.

  The second optical adjustment layer 3 ′ is preferably formed from one or more materials selected from the group consisting of organic substances and inorganic substances, for example, a mixture of an inorganic substance and an organic substance, an organic substance alone, or an inorganic substance alone. can do. As an inorganic substance and an organic substance, the thing similar to what was illustrated by the 1st optical adjustment layer 3 can be mentioned. The thickness of the second optical adjustment layer 3 ′ is preferably about 5 to 300 nm, more preferably 10 to 100 nm, and further preferably 20 to 40 nm. By making the film thickness within the above range, the pattern visibility can be further improved, which is preferable.

In addition, the material for forming the second optical adjustment layer 3 ′ is not particularly limited, and the same material as the first optical adjustment layer 3 can be exemplified. Among the inorganic substances, the refractive index is high. , TiO ₂ , Nb ₂ O ₅ , ZrO _{2 and} other metal oxides can be preferably used. Further, the element ratio between the metal element and the carbon contained in the second optical adjustment layer 3 ′ (metal element / carbon) is not particularly limited, but it is 0.15 or more that the pattern visibility. Is preferable from the viewpoint that can be suitably controlled. About the element ratio of the said metal element and carbon, it can measure by the same method as the measuring method in a 1st optical adjustment layer. Similarly to the first optical adjustment layer 3, the second optical adjustment layer 3 ′ may contain nanoparticles having an average particle diameter of 1 nm to 500 nm.

  The refractive index of the second optical adjustment layer 3 ′ is not particularly limited as long as it is higher than the refractive index of the first optical adjustment layer 3 and lower than the refractive index of the transparent conductive layer 4. It is preferably about 1.60 to 2.40. It is preferable that the refractive index of the second optical adjustment layer 3 ′ is in the above range because the pattern visibility of the transparent conductive layer can be suppressed.

  The difference in refractive index between the first optical adjustment layer 3 and the second optical adjustment layer 3 ′ is not particularly limited, but is preferably about 0.05 to 0.90, preferably 0.10 to 0 More preferably, it is about .30. It is preferable that the refractive index difference between the first optical adjustment layer 3 and the second optical adjustment layer 3 ′ is in the above range because the pattern visibility of the transparent conductive layer can be suppressed.

(1-3) Transparent conductive layer The transparent conductive layer 4 is preferably a layer formed of a metal oxide. As the metal oxide, metal oxidation of at least one metal selected from the group consisting of indium, tin, zinc, gallium, antimony, titanium, silicon, zirconium, magnesium, aluminum, gold, silver, copper, palladium, tungsten A thing is used suitably. The metal oxide may further contain a metal atom shown in the above group, if necessary. Among these, indium tin oxide (ITO) is preferable.

  The thickness of the transparent conductive layer 4 is not particularly limited, but the thickness is preferably 10 nm or more in order to obtain a continuous film having good surface resistance of 300Ω / □ or less. When the film thickness becomes too thick, the transparency is lowered, and therefore, it is preferably 15 nm to 35 nm, and more preferably 20 nm to 30 nm. If the thickness of the transparent conductive layer 4 is less than 10 nm, the electrical resistance of the film surface becomes high and it becomes difficult to form a continuous film. Further, when the thickness of the transparent conductive layer 4 exceeds 35 nm, the transparency may be lowered.

  The surface resistance value of the transparent conductive layer 4 is not particularly limited and may be 300Ω / □ or less, preferably 100Ω / □ or less, more preferably 0.1 to 100Ω / □, 80Ω / □ is more preferable. It is preferable that the surface resistance value of the conductive layer is 100Ω / □ or less because power consumption when a touch panel or the like is used is suppressed and operability is improved.

  It does not specifically limit as a formation method of the transparent conductive layer 4, A conventionally well-known method is employable. Specifically, for example, a vacuum deposition method, a sputtering method, and an ion plating method can be exemplified. These methods can be appropriately employed depending on the required film thickness.

  The transparent conductive layer 4 may be amorphous or crystalline.

  The transparent conductive layer 4 used in the present invention is patterned. As the pattern forming method, any known method can be adopted, but for example, etching can be performed. Examples of the shape of the patterning portion include a stripe shape and a square shape. The patterned transparent conductive layer 4 has a level difference between a pattern opening having no transparent conductive layer and a pattern having a transparent conductive layer. The level difference can be filled with the adhesive layer 8.

  The refractive index of the transparent conductive layer 4 is not particularly limited, but is usually about 1.75 to 2.14.

(1-4) Configuration of Transparent Conductor The transparent conductor 5 used in the present invention may have the transparent base material 2, the first optical adjustment layer 3, and the transparent conductive layer 4 in this order, and the second optical adjustment. Although other layers such as a layer 3 ′ may further be included, the transparent conductive layer 4 is preferably formed directly on the first optical adjustment layer 3 from the viewpoint of suppressing pattern appearance.

  If necessary, the transparent substrate 2 may further be provided with an anti-blocking layer, a hard coat layer, an easy adhesion layer, and the like.

  Generally, the hard coat layer is provided for the purpose of imparting hardness to the film to prevent scratches, and the anti-blocking layer is provided for forming slipperiness and blocking resistance by forming irregularities on the film surface. Provided. The hard coat layer and the anti-blocking layer can be formed between the first optical adjustment layer 3 (or the second optical adjustment layer 3 ′) and the transparent substrate 2, or the transparent conductive layer 4 of the transparent substrate 2 can be formed. It can also be formed on the surface opposite to the side on which is formed.

  Examples of the resin that forms the hard coat layer include thermosetting resins, thermoplastic resins, ultraviolet curable resins, electron beam curable resins, and two-component mixed resins. Among these, curing by ultraviolet irradiation is possible. An ultraviolet curable resin capable of efficiently forming a hard coat layer by a simple processing operation is preferable. Examples of the ultraviolet curable resin include various types such as polyester, acrylic, urethane, amide, silicone, and epoxy, and examples include ultraviolet curable monomers, oligomers, and polymers. Examples of the ultraviolet curable resin preferably used include those having an ultraviolet polymerizable functional group, particularly those containing an acrylic monomer or oligomer component having 2 or more, particularly 3 to 6 functional groups. . Further, an ultraviolet polymerization initiator is blended in the ultraviolet curable resin.

  The formation method in particular of a hard-coat layer is not restrict | limited, A suitable system can be employ | adopted. For example, a method of applying a resin composition for forming a hard coat layer on the transparent substrate 2 and drying and then curing is employed. The resin composition is applied by an appropriate method such as phantom, die coater, casting, spin coating, phanten metalling, and gravure. In the application, the resin composition is preferably diluted with a common solvent such as toluene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, isopropyl alcohol, ethyl alcohol, and the like to prepare a solution.

  As the anti-blocking layer, a curable resin layer containing fine particles, a curable resin composition using a coating composition containing two or more components that are phase-separated, or a combination thereof are used. Thus, those having irregularities formed on the surface are preferably used. As the components of the curable resin layer, those described above as the components of the hard coat layer are preferably used. Moreover, as a coating composition containing 2 or more types of components which phase-separate, the composition as described, for example in international publication 2005/073763 pamphlet can be used suitably.

  The transparent conductor 5 used in the present invention can be a transparent conductor wound body in which the long transparent conductor 5 is wound in a roll shape. Moreover, the wound body of the long transparent conductor 5 uses the roll-shaped wound body of the long transparent base material 2, the above-mentioned transparent conductive layer 4, the 1st optical adjustment layer 3, and necessity. Accordingly, any additional layers can be formed by roll-to-roll method.

(2) Pressure-sensitive adhesive layer (2-1) Base pressure-sensitive adhesive region The pressure-sensitive adhesive layer 8 used in the present invention contains a base pressure-sensitive adhesive region 7 essentially formed of a pressure-sensitive adhesive composition, and inorganic particles containing inorganic particles. Region 6. Here, “essentially formed by the pressure-sensitive adhesive composition” means that the element ratio of the metal element of the inorganic particles in the base pressure-sensitive adhesive region 7 is 1 atomic% or less, and 0.5 atomic% or less. And is particularly preferably 0 atomic% (that is, containing no inorganic particles). The method for measuring the element ratio of the inorganic particles is based on the method described in the examples.

  The pressure-sensitive adhesive composition is not particularly limited as long as it is a composition that can be used for optical applications. For example, an acrylic pressure-sensitive adhesive composition, a rubber-based pressure-sensitive adhesive composition, a silicone-based pressure-sensitive adhesive composition, and a polyester-based pressure-sensitive adhesive Agent composition, urethane pressure-sensitive adhesive composition, epoxy pressure-sensitive adhesive composition, and polyether-based pressure-sensitive adhesive composition can be appropriately selected and used, and these can be used alone or in combination of two or more. Can be used. Among these, an acrylic pressure-sensitive adhesive having a (meth) acrylic polymer as a base polymer is preferable from the viewpoints of transparency, workability, durability, and the like.

  Although it does not specifically limit as said (meth) acrylic-type polymer, It is obtained by superposing | polymerizing the monomer component containing the alkyl (meth) acrylate which has a C4-C24 alkyl group in the terminal of an ester group. Can be mentioned. Alkyl (meth) acrylate refers to alkyl acrylate and / or alkyl methacrylate, and (meth) in the present invention has the same meaning.

  Examples of the alkyl (meth) acrylate include those having a linear or branched alkyl group having 4 to 24 carbon atoms, and having a linear or branched alkyl group having 4 to 9 carbon atoms. Alkyl (meth) acrylates are preferred because they are easy to balance the adhesive properties. These alkyl (meth) acrylates can be used alone or in combination of two or more.

  In the present invention, the alkyl (meth) acrylate having an alkyl group having 4 to 24 carbon atoms at the ester terminal is 40% by weight or more based on the total amount of the monofunctional monomer component forming the (meth) acrylic polymer. It is preferably 50% by weight or more, more preferably 60% by weight or more. It is preferable to use an alkyl (meth) acrylate having an alkyl group having 4 to 24 carbon atoms at the ester end in the above range because the adhesive property can be easily balanced.

  The monomer component that forms the (meth) acrylic polymer may contain a copolymerization monomer other than the alkyl (meth) acrylate as a monofunctional monomer component. A copolymerization monomer can be used as the remainder of the said alkyl (meth) acrylate in a monomer component.

  Examples of the copolymerization monomer include a cyclic nitrogen-containing monomer, a hydroxyl group-containing monomer, a carboxyl group-containing monomer, and a monomer having a cyclic ether group.

  In addition to the monofunctional monomer, the monomer component forming the (meth) acrylic polymer can contain a polyfunctional monomer as necessary in order to adjust the cohesive force of the pressure-sensitive adhesive. .

  The polyfunctional monomer is a monomer having at least two polymerizable functional groups having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group. For example, dipentaerythritol hexa (meth) acrylate, 1, Examples include 6-hexanediol di (meth) acrylate and trimethylolpropane tri (meth) acrylate. A polyfunctional monomer can be used individually by 1 type or in combination of 2 or more types.

  The amount of the polyfunctional monomer used varies depending on the molecular weight, the number of functional groups, and the like, but it is preferably used at 3 parts by weight or less with respect to 100 parts by weight of the monofunctional monomer in total. Adhesive force can be improved when the usage-amount of a polyfunctional monomer exists in the said range.

  The production of such a (meth) acrylic polymer can be appropriately selected from known production methods such as radiation polymerization such as solution polymerization and ultraviolet polymerization, various radical polymerizations such as bulk polymerization and emulsion polymerization. Further, the (meth) acrylic polymer obtained may be a random copolymer, a block copolymer, a graft copolymer or the like.

  The polymerization initiator, chain transfer agent, emulsifier and the like used for radical polymerization are not particularly limited and can be appropriately selected and used. In addition, the weight average molecular weight of a (meth) acrylic-type polymer can be controlled by the usage-amount of a polymerization initiator and a chain transfer agent, and reaction conditions, The usage-amount is suitably adjusted according to these kinds.

  For example, in solution polymerization or the like, for example, ethyl acetate, toluene or the like is used as a polymerization solvent. As a specific example of solution polymerization, the reaction is performed under an inert gas stream such as nitrogen and a polymerization initiator is added, and the reaction is usually performed at about 50 to 70 ° C. under reaction conditions for about 5 to 30 hours.

  Examples of thermal polymerization initiators used for solution polymerization include azo initiators such as 2,2′-azobisisobutyronitrile, persulfates such as potassium persulfate, and di (2-ethylhexyl) peroxy. List peroxide-based initiators such as dicarbonates, redox-based initiators that combine peroxides and reducing agents, such as combinations of persulfates and sodium bisulfite, and peroxides and sodium ascorbate. However, it is not limited to these.

  The polymerization initiator may be used alone or in combination of two or more, but the total content is 0.005 to 1 part by weight with respect to 100 parts by weight of the monomer. Is preferably about 0.02 to 0.5 parts by weight.

  Examples of the chain transfer agent include lauryl mercaptan, glycidyl mercaptan, mercaptoacetic acid, 2-mercaptoethanol, thioglycolic acid, 2-ethylhexyl thioglycolate, and 2,3-dimercapto-1-propanol. The chain transfer agent may be used alone or in combination of two or more, but the total content is 0.1 parts by weight with respect to 100 parts by weight of the total amount of monomer components. Less than or equal to

  Examples of the emulsifier used for emulsion polymerization include anionic emulsifiers such as sodium lauryl sulfate and ammonium lauryl sulfate, and nonionic emulsifiers such as polyoxyethylene alkyl ether and polyoxyethylene alkylphenyl ether. These emulsifiers may be used alone or in combination of two or more.

  Moreover, when manufacturing a (meth) acrylic-type polymer by radiation polymerization, it can superpose | polymerize and manufacture the said monomer component by irradiating radiation, such as an electron beam and an ultraviolet-ray. When the radiation polymerization is performed with an electron beam, it is not particularly necessary to include a photopolymerization initiator in the monomer component. However, when the radiation polymerization is performed with ultraviolet polymerization, the polymerization time is particularly shortened. For example, a photopolymerization initiator can be contained in the monomer component because of the advantages that can be achieved. A photoinitiator can be used individually by 1 type or in combination of 2 or more types.

  The photopolymerization initiator is not particularly limited, but is not particularly limited as long as it initiates photopolymerization, and a commonly used photopolymerization initiator can be used. For example, benzoin ether photopolymerization initiator, acetophenone photopolymerization initiator, α-ketol photopolymerization initiator, aromatic sulfonyl chloride photopolymerization initiator, photoactive oxime photopolymerization initiator, benzoin photopolymerization initiator Agents, benzyl photopolymerization initiators, benzophenone photopolymerization initiators, ketal photopolymerization initiators, thioxanthone photopolymerization initiators, acylphosphine oxide photopolymerization initiators, and the like can be used. Examples of the benzoin ether photopolymerization initiator include 2,2-dimethoxy-1,2-diphenylethane-1-one (trade name: Irgacure 651, manufactured by BASF). Examples of the acetophenone-based photopolymerization initiator include 1-hydroxycyclohexyl phenyl ketone (trade name: Irgacure 184, manufactured by BASF). Examples of the α-ketol photopolymerization initiator include 2-methyl-2-hydroxypropiophenone. Examples of the aromatic sulfonyl chloride photopolymerization initiator include 2-naphthalene sulfonyl chloride. Examples of the photoactive oxime photopolymerization initiator include 1-phenyl-1,1-propanedione-2- (o-ethoxycarbonyl) -oxime. Examples of the benzoin photopolymerization initiator include benzoin. Examples of the benzyl photopolymerization initiator include benzyl. Examples of the benzophenone photopolymerization initiator include benzophenone. Examples of the ketal photopolymerization initiator include benzyl dimethyl ketal. Examples of the thioxanthone photopolymerization initiator include thioxanthone. Examples of the acylphosphine photopolymerization initiator include bis (2,6-dimethoxybenzoyl) phenylphosphine oxide, bis (2,6-dimethoxybenzoyl) (2,4,4-trimethylpentyl) phosphine oxide, and the like. It is done.

  Although the usage-amount of a photoinitiator is not restrict | limited in particular, For example, it is preferable that it is 0.01-10 weight part with respect to 100 weight part of said monomer components.

  The weight average molecular weight of the (meth) acrylic polymer used in the present invention is preferably 400,000 to 4,000,000. By making the weight average molecular weight larger than 400,000, it is possible to satisfy the durability of the pressure-sensitive adhesive layer, or to suppress the occurrence of adhesive residue due to the reduced cohesive force of the pressure-sensitive adhesive layer. On the other hand, when the weight average molecular weight is larger than 4 million, the bonding property tends to be lowered. Furthermore, in the solution system, the viscosity becomes too high, and coating may be difficult. The weight average molecular weight is a value measured by GPC (gel permeation chromatography) and calculated in terms of polystyrene. In addition, it is difficult to measure the molecular weight of the (meth) acrylic polymer obtained by radiation polymerization.

  The pressure-sensitive adhesive composition used in the present invention can contain a crosslinking agent. Examples of crosslinking agents include isocyanate crosslinking agents, epoxy crosslinking agents, silicone crosslinking agents, oxazoline crosslinking agents, aziridine crosslinking agents, silane crosslinking agents, alkyletherified melamine crosslinking agents, metal chelate crosslinking agents, Examples of the crosslinking agent include oxides, and these can be used alone or in combination of two or more. As said crosslinking agent, an isocyanate type crosslinking agent and an epoxy-type crosslinking agent are used preferably.

  The crosslinking agent may be used alone or in combination of two or more, but the total content is based on 100 parts by weight of the (meth) acrylic polymer. The crosslinking agent is preferably contained in an amount of 10 parts by weight or less, and more preferably in the range of 0.01 to 10 parts by weight.

  The pressure-sensitive adhesive composition used in the present invention can contain a (meth) acrylic oligomer in order to improve the adhesive force. The (meth) acrylic oligomer is preferably a polymer having a glass transition temperature (Tg) higher than that of the (meth) acrylic polymer used in the present invention and a small weight average molecular weight. Such a (meth) acrylic oligomer functions as a tackifier resin and has the advantage of increasing the adhesive force. The blending amount of the (meth) acrylic oligomer is preferably 20 parts by weight or less, more preferably 0.01 to 10 parts by weight with respect to 100 parts by weight of the (meth) acrylic polymer.

  Furthermore, the pressure-sensitive adhesive composition used in the present invention can contain a silane coupling agent. The amount of the silane coupling agent is preferably 1 part by weight or less, more preferably 0.01 to 1 part by weight, based on 100 parts by weight of the (meth) acrylic polymer.

  Examples of silane coupling agents that can be preferably used include epoxy group-containing silane coupling agents such as 3-glycidoxypropyltriethoxysilane, amino group-containing silane coupling agents such as 3-aminopropyltrimethoxysilane, and 3-acrylic acid. Examples include (meth) acrylic group-containing silane coupling agents such as loxypropyltrimethoxysilane, and isocyanate group-containing silane coupling agents such as 3-isocyanatopropyltriethoxysilane.

  Furthermore, the pressure-sensitive adhesive composition used in the present invention may contain other known additives such as surfactants, plasticizers, and tackifiers.

  The base pressure-sensitive adhesive region 7 is formed of the pressure-sensitive adhesive composition, and the formation method will be described later. The refractive index of the base adhesive region 7 is usually about 1.40 to 1.55.

(2-2) Inorganic particle-containing region The inorganic particles constituting the inorganic particle-containing region 6 of the pressure-sensitive adhesive layer 8 used in the present invention are not particularly limited, but have a higher refractive index than the base pressure-sensitive adhesive layer 7. It is preferable that high refractive index particles are included.

  The refractive index of the inorganic particles used in the present invention is not particularly limited, but is generally about 1.60 to 2.74 because the refractive index of the base adhesive layer is about 1.40 to 1.55. It is preferable that it is about 1.65 to 2.20. It is preferable for the refractive index of the inorganic particles to be in the above range because the refractive index of one main surface of the pressure-sensitive adhesive layer (the surface of the inorganic particle-containing region 6) can be increased.

  The refractive index of the inorganic particles is preferably larger than the refractive index of the base adhesive layer 7, and the difference between the refractive index of the inorganic particles and the refractive index of the base adhesive layer 7 is 0.2 to 1.3. It is preferable that it is 0.3 and 1.2. If the difference in refractive index is less than 0.2, a large amount of inorganic particles are required to increase the refractive index of the inorganic particle-containing region 6, and it tends to be difficult to maintain transparency and adhesiveness. . In addition, when the difference in refractive index exceeds 1.3, the difference in refractive index from the pressure-sensitive adhesive layer increases, and it becomes difficult to maintain transparency (low haze value) due to strong scattering by inorganic particles. . It is preferable that the difference in refractive index is in the above-mentioned range since it is possible to control both transparency and high refractive index.

The inorganic particles are preferably one or more metal oxides selected from the group consisting of TiO ₂ , ZrO ₂ , CeO ₂ , Al ₂ O ₃ , BaTiO ₃ , Nb ₂ O ₅ and SnO _2. From an optical viewpoint, it is more preferable to include zirconia particles (ZrO ₂ ) having no absorption in the visible light region and having a small absorption edge wavelength.

  The average primary particle diameter of the inorganic particles is preferably 3 nm to 100 nm, more preferably 5 nm to 50 nm, still more preferably 5 nm to 30 nm, and particularly preferably 5 nm to 20 nm. When the average primary particle diameter is in the above range, both transparency and high refractive index can be controlled. The average primary particle size can be measured by particle size distribution measurement or direct observation by TEM.

  In this invention, although the inorganic particle containing area | region 6 is formed in the adhesive layer 8 using the said inorganic particle, the formation method is mentioned later.

In the inorganic particle-containing region 6, the element ratio of the metal element and carbon derived from the inorganic particles (metal element / carbon) is 0.01 to 0.2, preferably 0.05 to 0.15, It is more preferable that it is 0.07-0.13. If the element ratio of the metal element and carbon derived from inorganic particles is less than the above range, the pattern visibility of the transparent conductive layer may be deteriorated, and if it exceeds the above range, the adhesive strength may be reduced or the patterned transparent conductive layer may be deteriorated. The visibility of may increase. Here, the element ratio between the metal element and carbon contained in the inorganic particles specifically indicates, for example, the element ratio of Zr and C (Zr / C) when the inorganic particles are ZrO ₂ . Moreover, when an inorganic particle contains a some metal element, it is the ratio of the total amount of all the metal elements, and carbon.

In the inorganic particle-containing region 6, the element ratio between the metal element derived from the inorganic particle and carbon can be measured by X-ray photoelectron spectroscopy (ESCA) under the following conditions. Measurement equipment and conditions are as follows.
(Measurement condition)
Measuring apparatus: Quantera SMX, manufactured by ULVAC-PHI, Inc. Measurement conditions: X-ray source: Monochrome AlKα
X Ray setting: 200 μmφ, 15 kV, 26 W
Photoelectron extraction angle: 45 ° to the sample surface
Charge neutralization condition: combined use of electron neutralizing gun and Ar ion gun (neutralization mode) Binding energy: Peak derived from CC bond in C1s spectrum is corrected to 285.0 eV Acceleration voltage of Ar ion gun: 1 kV
Etching rate of Ar ion gun: 2 nm / min (SiO ₂ conversion)
Etching area: 2mm x 2mm
Under the above conditions, a depth profile of the element ratio with respect to the depth direction is created. In the depth range corresponding to the inorganic particle containing region 6 in the obtained depth profile (that is, the depth range where the element ratio of the metal element is 1 atomic% or more), all elements of the metal element (however, excluding H and He) ) And the element ratio (atomic%) of all carbon elements (excluding H and He), and the integrated value of the metal element and the integrated value of carbon. The value calculated as the ratio is adopted.
(In the above description, a method using Quantera SMX manufactured by ULVAC-PHI, Inc. is described as a measuring device, but it is also possible to measure with an equivalent device of the measuring device.)

  On the surface of the inorganic particle-containing region 6 (the surface indicated by arrow B in FIGS. 1 and 2, that is, the surface in contact with the transparent conductive layer 4), the inorganic particles are substantially uniform in the in-plane direction of the inorganic particle-containing region 6. It is preferable that an adhesive layer having the same composition as that of the base adhesive layer 7 and the inorganic particles are present in a mixed manner. The dispersion state in the in-plane direction of the inorganic particle-containing region 6 can be confirmed by observing the surface of the inorganic particle-containing region 6 with a scanning electron microscope (SEM).

  The area ratio (surface coverage) occupied by the inorganic particles on the surface of the inorganic particle-containing region 6 is preferably 55% or more and less than 100%, more preferably 60 to 99%, and more preferably 70 to 99. % Is more preferable, and 75 to 99% is particularly preferable. It is preferable that the area ratio of the inorganic particles is 55% or more because the refractive index on the surface of the inorganic particle-containing region 6 can be increased while maintaining the degree of adhesiveness required for optical applications. In addition, as the area ratio of the inorganic particles is higher, when the inorganic particle-containing region 6 is failed to be bonded to the transparent conductive layer 4, no glue remains and can be easily peeled off, thereby improving reworkability. Is preferable. In addition, if the area ratio (surface coverage) of the inorganic particles is measured as an area with respect to the entire area in a square region having one side of 10 μm to 200 μm, the size of the square region is not particularly limited. It can be measured by the area of a rectangular region having a short side of 18 μm. That is, the surface coverage is a value calculated by (area of the region portion where the inorganic particles exist in the measurement region) / (total area of the measurement region) × 100.

  FIG. 3 is an enlarged view of a part of the pressure-sensitive adhesive layer 8. The concentration distribution of the inorganic particles 9 in the thickness direction of the pressure-sensitive adhesive layer 8 is the surface of the inorganic particle-containing region 6 (that is, the surface of the pressure-sensitive adhesive layer 8, the surface in contact with the transparent conductive layer 4, the arrow in FIG. 3). It is preferable that it decreases substantially continuously from the surface of B) toward the other side of the inorganic particle-containing region. That is, the concentration distribution of the inorganic particles 9 in the inorganic particle-containing region 6 is highest on the surface of the inorganic particle-containing region 6 on the side in contact with the transparent conductive layer 4 and decreases according to the thickness direction of the inorganic particle-containing region 6. It is preferable to have a distribution. Due to the presence of the inorganic particles 9 in such a distribution, the refractive index of the inorganic particle-containing region 6 becomes the largest on the side in contact with the transparent conductive layer of the inorganic particle-containing region 6, and the other of the inorganic particle-containing regions It becomes smaller continuously toward the side. Therefore, in the present invention, the refractive index on the surface of the pressure-sensitive adhesive layer 8 can be increased, and even when bonded to the transparent conductive layer 4, reflection at the interface between the pressure-sensitive adhesive layer 8 and the transparent conductive layer 4 is possible. The rate can be reduced. Further, the inorganic particle-containing region 6 and the base pressure-sensitive adhesive are arranged so as to have a distribution in which the inorganic particles 9 decrease in the thickness direction from the side in contact with the transparent conductive layer 4 of the inorganic particle-containing region 6. A change in bulk physical properties with the region 7 can be reduced, which is preferable from the viewpoint of adhesive function and adhesion reliability.

  The fact that the concentration distribution of the inorganic particles 9 decreases in the thickness direction of the pressure-sensitive adhesive layer 8 can be specified by acquiring a depth profile of the element ratio using ESCA. That is, the element ratio of the inorganic atoms contained in the inorganic particles 9 contained in the inorganic particle-containing region 6 tends to decrease substantially continuously from the surface on the inorganic particle-containing region 6 side to the other surface. is there. The term “substantially continuous” means that the pressure-sensitive adhesive layer 8 strictly allows the inorganic particles 9 to partially contain a region that does not continuously decrease. It means that the region where 9 does not continuously decrease is dominant, and that the pressure-sensitive adhesive layer 8 does not allow the inorganic particles 9 to contain regions where they rapidly decrease. A line graph is shown with the depth from the surface of the pressure-sensitive adhesive layer 8 as the horizontal axis and the depth direction of the metal element content (unit: atomic%) of the inorganic particles contained in the pressure-sensitive adhesive layer 8 as the vertical axis. There are times when you can see a trend of declining as a whole, although it is undulating on the zigzag. This is also the case when “inorganic particles 9 decrease substantially continuously”. When such a determination is difficult, the determination is performed as follows. If the average value including the measurement points before and after using the moving average method is calculated and plotted again, if there is a tendency to decrease substantially continuously, “inorganic particles 9 are substantially continuous. This is the case when it decreases to You can calculate the average including one point of data before and after an arbitrary measurement point (ternary transfer average). If the trend is still difficult to read, calculate the average including data of two or more points before and after. (When calculating an average including data of two or more points before and after, it is a 5-term moving average).

  When the inorganic particles 9 are uniformly dispersed with respect to the base resin, when the depth profile of the element ratio is obtained by ESCA, the plot of the element ratio with respect to the depth has a shape having a peak. This is due to the etching rate of the base resin component and the inorganic particle component. Since the resin component generally has a higher etching rate and the inorganic particles are lower, the base resin is preferentially etched, and the apparent inorganic element amount tends to increase at a certain depth. Thereafter, when the inorganic particles are also sufficiently etched, the amount of elements tends to decrease. On the other hand, for a system having a concentration gradient as in the present invention, the deeper the etching, the smaller the amount of elements, so the element ratio plot does not have a peak shape, but the aforementioned abbreviation. It tends to decrease continuously. This produces a continuous change in the refractive index, resulting in improved pattern visibility. Therefore, the present invention is characterized by having an inorganic particle-containing region having no peak in the depth profile of the element ratio by ESCA.

  The reduction rate of the inorganic particles 9 is not particularly limited, but is preferably 0.09 to 0.20 atomic% / nm. Since the reduction rate of the inorganic particles 9 is in the above range, the pattern visibility of the transparent conductive layer can be suitably suppressed, which is preferable.

  The average thickness of the inorganic particle-containing region 6 is not particularly limited, but is preferably 20 nm to 600 nm and more preferably 20 nm to 300 nm from the viewpoint of suppressing the pattern visibility of the transparent conductive layer. More preferably, the thickness is 20 nm to 200 nm. By setting it as the said range, since there exists a tendency which can reduce the visibility of the patterned transparent conductive layer, it is preferable. The boundary between the inorganic particle-containing region 6 and the base pressure-sensitive adhesive region 7 has an irregular uneven shape. In the present invention, the average thickness of the inorganic particle-containing region 6 is a measured value of the depth of the uneven shape. Can be determined by averaging. The thickness of the base pressure-sensitive adhesive region 7 is a value obtained by subtracting the average thickness of the inorganic particle-containing region 6 from the thickness of the entire pressure-sensitive adhesive layer 8. The measuring method of the average thickness of the inorganic particle containing area | region 6 can be measured by the method as described in an Example.

  The refractive index of the surface of the inorganic particle-containing region 6 on the side in contact with the transparent conductive layer 4 (surface indicated by arrow B in FIGS. 1 and 2) is preferably 1.47 to 1.74, and 1.58 to 1.74 is more preferable, and 1.60 to 1.74 is more preferable. It is preferable that the average refractive index of the surface of the inorganic particle-containing region 6 is in the above range because the pattern visibility of the transparent conductive layer can be suppressed. The average refractive index of the surface of the inorganic particle-containing region 6 is preferably lower than the refractive index of the transparent conductive layer 4.

(2-3) Properties of the pressure-sensitive adhesive layer The overall thickness of the pressure-sensitive adhesive layer 8 is not particularly limited, but is preferably 5 μm to 500 μm, for example, and more preferably 5 μm to 400 μm. It is preferably 5 μm to 300 μm, more preferably 5 μm to 250 μm. When the thickness of the pressure-sensitive adhesive layer 8 is less than 5 μm, the adhesion to the transparent conductor 5 tends to be poor. On the other hand, when the thickness of the pressure-sensitive adhesive layer 8 exceeds 500 μm, the pressure-sensitive adhesive composition is not sufficiently dried during the application and drying of the pressure-sensitive adhesive layer 8, and bubbles remain or the pressure-sensitive adhesive layer Since thickness unevenness is generated on the surface No. 8 and wrinkles and the like are likely to occur during winding in the process, problems in appearance tend to become obvious.

  The haze value of the pressure-sensitive adhesive layer 8 of the present invention is preferably 1 or less, more preferably less than 1, more preferably from 0 to 0.9, and further preferably from 0 to 0.8. Further preferred is 0 to 0.6. When the haze value is within the above range, the transparency required for the pressure-sensitive adhesive layer used in optical applications can be satisfied.

  The total light transmittance of the pressure-sensitive adhesive layer 8 is preferably 80% or more, and more preferably 90% or more. It is preferable for the total light transmittance to be in the above range because excellent transparency and excellent appearance can be obtained. The total light transmittance can be measured according to JIS K7361.

  Further, the pressure-sensitive adhesive layer 8 on the side opposite to the side in contact with the transparent conductive layer 4 (the surface of the base pressure-sensitive adhesive layer 7, the surface of the arrow A in FIGS. 1 to 3) is separated until practical use. The pressure-sensitive adhesive layer surface can be protected with a mold film or the like. As the release film, those described below can be used.

(3) Laminate In the laminate of the present invention, the pressure-sensitive adhesive layer 8 and the transparent conductor 5 are in contact with the inorganic particle-containing region 6 of the pressure-sensitive adhesive layer 8 and the transparent conductive layer 4 of the transparent conductor 5. It can form by laminating | stacking.

In the laminate of the present invention, the color difference (ΔE) between the reflected light of the pattern portion of the transparent conductive layer 4 and the reflected light immediately below the pattern opening can be 3.0 or less by adopting the above configuration. Thus, the pattern appearance is suppressed. Here, the "color difference", ^{L *} difference [Delta] L ^*, with ^{a *} difference .DELTA.a ^*, and ^{b *} of the difference [Delta] b ^*,
ΔE = {(ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² } ^0.5
It is a value represented by.

2. Manufacturing method of laminate The manufacturing method of the laminate of the present invention is as follows.
A step of preparing a transparent conductor having a transparent substrate, a first optical adjustment layer and a transparent conductive layer in this order;
A dispersion containing inorganic particles is applied to one main surface of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition, and the inorganic particles contained in the dispersion are thickened from one main surface of the pressure-sensitive adhesive layer. Infiltrating in the direction to form a base pressure-sensitive adhesive region essentially formed by the pressure-sensitive adhesive composition, and an inorganic particle-containing region,
Bonding the pressure-sensitive adhesive layer and the transparent conductor so that the inorganic particle-containing region of the pressure-sensitive adhesive layer and the transparent conductive layer of the transparent conductor are in contact with each other;
The element ratio (metal element / carbon) of the metal element and carbon contained in the inorganic particle-containing region is 0.01 to 0.2.

  About the said transparent conductor, an adhesive composition, and an inorganic particle, the thing as described in this specification can be mentioned. The amount of the metal element derived from the inorganic particles in the inorganic particle-containing region is also as described above.

  The pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition does not contain inorganic particles. It can be formed by applying the pressure-sensitive adhesive composition to a support or the like and drying and removing the polymerization solvent or the like. In applying the pressure-sensitive adhesive composition, one or more solvents other than the polymerization solvent may be added as appropriate.

  As said support body, it is preferable that it is a material which supports an adhesive layer and can be peeled from an adhesive layer. Examples of the support include a release film, a low adhesive substrate made of a fluorine-based polymer, and a low adhesive substrate made of a nonpolar polymer.

  Examples of the constituent material of the release film include resin films such as polyethylene, polypropylene, polyethylene terephthalate, and polyester films, porous materials such as paper, cloth, and nonwoven fabric, nets, foam sheets, metal foils, and laminates thereof. Suitable thin leaf bodies and the like can be mentioned, but a resin film is suitably used from the viewpoint of excellent surface smoothness.

  Examples of the resin film include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, polyurethane film, ethylene- A vinyl acetate copolymer film etc. are mentioned.

  The thickness of the release film is usually 5 μm to 200 μm, preferably about 5 μm to 125 μm. For the release film, if necessary, release agent and antifouling treatment with a silicone-based, fluorine-based, long-chain alkyl-based or fatty acid amide-based release agent, silica powder, etc., coating type, kneading type, An antistatic treatment such as a vapor deposition type can also be performed. In particular, the release property from the pressure-sensitive adhesive layer can be further improved by appropriately performing a release treatment such as silicone treatment, long-chain alkyl treatment, or fluorine treatment on the surface of the release film.

  Various methods are used as a method of applying the pressure-sensitive adhesive composition. Specifically, for example, by roll coat, kiss roll coat, gravure coat, reverse coat, roll brush, spray coat, dip roll coat, bar coat, knife coat, air knife coat, curtain coat, lip coat, die coater, etc. Examples thereof include an extrusion coating method.

  Although the said heat drying temperature is not specifically limited, It is preferable that it is 40-200 degreeC, 50-180 degreeC is more preferable, and 60-170 degreeC is further more preferable. By setting the heating temperature within the above range, a transparent resin layer having excellent adhesive properties can be obtained. As the drying time, an appropriate time can be adopted as appropriate. The drying time is preferably 5 seconds to 20 minutes, more preferably 5 seconds to 10 minutes, and particularly preferably 10 seconds to 5 minutes.

  The pressure-sensitive adhesive layer can also be formed by polymerizing the pressure-sensitive adhesive composition by irradiating active energy rays such as ultraviolet rays. For ultraviolet irradiation, a high-pressure mercury lamp, a low-pressure mercury lamp, a metal halide lamp, or the like can be used. In addition, while producing a (meth) acrylic-type polymer from a monomer component, an adhesive layer can be formed. A crosslinking agent or the like can be appropriately blended with the monomer component. As the monomer component, a part of the monomer component previously polymerized into a syrup can be used for ultraviolet irradiation.

  In the present invention, one main surface of the pressure-sensitive adhesive layer is coated with a dispersion containing inorganic particles on at least one main surface side of the obtained pressure-sensitive adhesive layer (not containing inorganic particles). Can penetrate the inorganic particles. As a specific method, as shown in FIG. 4, a dispersion 10 containing inorganic particles 9 is applied to the surface of the pressure-sensitive adhesive layer 8 '(FIG. 4 (a)). The surface of the pressure-sensitive adhesive layer 8 ′ is swollen by the solvent of the dispersion liquid 10, and in the process, the inorganic particles 9 in the dispersion liquid 10 penetrate into the pressure-sensitive adhesive layer 8 ′ in the thickness direction (FIG. 4B). . Thereafter, by drying the pressure-sensitive adhesive layer 8 ′, the solvent of the dispersion 10 can be evaporated to form the base pressure-sensitive adhesive region 7 and the inorganic particle-containing region 6 containing inorganic particles (FIG. 4 ( c)).

  The dispersion medium of the dispersion liquid needs to be compatible with the pressure-sensitive adhesive, and such a dispersion medium is selected from the group of water, an organic solvent, a liquid organic resin monomer, and a liquid organic resin oligomer. In addition, a solvent containing one type or two or more types can be given. Examples of the organic solvent include organic solvents such as alcohol, ether, ketone, and hydrocarbon. Examples of the liquid organic resin monomer include acrylic or methacrylic monomers such as methyl acrylate and methyl methacrylate, and epoxy monomers. Examples of the liquid organic resin oligomer include urethane acrylate oligomers, epoxy acrylate oligomers, and acrylate oligomers. Among these, alcohols and ketones are preferable because of coating properties, viscosity, and drying properties on the adhesive layer, and alkyl alcohols having 4 or less carbon atoms, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), and the like are more preferable. .

  Examples of the method for applying the dispersion containing the inorganic particles to the pressure-sensitive adhesive layer surface include the usual methods such as bar coating, reverse coating, spray coating, gravure coating, rod coating, dip roll coating, and bar coating. Extrusion coating using a knife coat, air knife coat, curtain coat, lip coat, die coater or the like.

  After applying the dispersion liquid containing inorganic particles to the surface of the pressure-sensitive adhesive layer, the inorganic particles can be permeated from one main surface of the pressure-sensitive adhesive layer by drying and removing the dispersion solvent and the like. The drying temperature and drying time are not particularly limited, and appropriate times can be appropriately employed. By sufficiently drying the applied dispersion solvent, a transparent resin layer having excellent adhesive properties can be obtained.

  In the present invention, the dispersion containing inorganic particles is applied to one main surface of the pressure-sensitive adhesive layer, and the inorganic solvent is permeated from one main surface of the pressure-sensitive adhesive layer by drying and removing the dispersion solvent and the like. In the pressure-sensitive adhesive layer, the inorganic particle-containing region 6 and the base pressure-sensitive adhesive region 7 can be formed. The inorganic particle-containing region 6 and the base pressure-sensitive adhesive region 7 are as described above.

  The laminated body of the present invention is obtained by bonding the obtained pressure-sensitive adhesive layer and the transparent conductor so that the inorganic particle-containing region of the pressure-sensitive adhesive layer and the transparent conductive layer of the transparent conductor are in contact with each other. Can do.

  The laminate of the present invention can be suitably used for a capacitive touch panel.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail using an Example, this invention is not limited to a following example, unless the summary is exceeded.

Production Example 1 (Production of pressure-sensitive adhesive layer)
(Preparation of acrylic oligomer (A-1))
In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube and a condenser, 60 parts by weight of dicyclopentanyl methacrylate (DCPMA), 40 parts by weight of methyl methacrylate (MMA), α- as a chain transfer agent After charging 3.5 parts by weight of thioglycerol and 100 parts by weight of toluene as a polymerization solvent and introducing nitrogen gas with gentle stirring to replace nitrogen, the liquid temperature in the flask was kept at around 70 ° C. for 1 hour. Stir. Next, 0.2 part by weight of 2,2-azobisisobutyronitrile as a polymerization initiator is put into the four-necked flask and reacted at 70 ° C. for 2 hours, followed by reaction at 80 ° C. for 2 hours. I let you. Thereafter, the reaction solution was added to a temperature atmosphere of 130 ° C., and toluene, the chain transfer agent and the unreacted monomer were removed by drying to obtain a solid acrylic oligomer (A-1). The acrylic oligomer (A-1) had a weight average molecular weight (Mw) of 5.1 × 10 ³ .

(Production of acrylic prepolymer composition (A-2))
A monomer component composed of 68 parts by weight of 2-ethylhexyl acrylate (2EHA), 14.5 parts by weight of N-vinyl-2-pyrrolidone (NVP), and 17.5 parts by weight of 2-hydroxyethyl acrylate (HEA) Furthermore, 0.035 parts by weight of a photopolymerization initiator (trade name: Irgacure 184, manufactured by BASF) and 0.035 parts by weight of a photopolymerization initiator (trade name: Irgacure 651, manufactured by BASF) are mixed with a viscosity ( Measurement conditions: BH viscometer No. 5 rotor, 10 rpm, measurement temperature: 30 ° C.) Pre-polymer composition (A-2) in which a part of the monomer component is polymerized by irradiating ultraviolet rays until the pressure reaches about 20 Pa · s. )

Next, 100 parts by weight of the obtained prepolymer composition (A-2), 5 parts by weight of the acrylic oligomer (A-1), 0.15 parts by weight of hexanediol diacrylate (HDDA), and a silane coupling agent (Product name: KBM-430, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.3 parts by weight was added and mixed to obtain an acrylic pressure-sensitive adhesive composition (A-3). Thickness of the resulting acrylic pressure-sensitive adhesive composition (A-3) after the pressure-sensitive adhesive layer is formed on the surface of the release film (trade name: MRF # 38, manufactured by Mitsubishi Plastics). The pressure-sensitive adhesive coating layer was formed by coating to 150 μm, and then a release film (trade name: MRF # 38, manufactured by Mitsubishi Resin Co., Ltd.) was bonded to the surface of the pressure-sensitive adhesive coating layer. . Then, the pressure-sensitive adhesive coating layer was photocured by irradiating with ultraviolet rays under the conditions of an illuminance of 5 mW / cm ² and a light amount of 1500 mJ / cm ² to form a pressure-sensitive adhesive layer A. The refractive index of the pressure-sensitive adhesive layer A was 1.49.

Example 1
One release film of the pressure-sensitive adhesive layer A obtained in Production Example 1 was peeled off. On the surface of the exposed pressure-sensitive adhesive layer, a coating dispersion liquid (dispersion medium: ethanol, particle concentration: 1.5% by weight) containing zirconia particles (ZrO ₂ , refractive index: 2.17, primary particle size: 20 nm), The transmittance of the dispersion liquid: 75%, manufactured by CIK Nanotech Co., Ltd.) was adjusted so that the average thickness of the inorganic particle-containing region was 200 nm. 5 and dried in a drying oven at 110 ° C. for 180 seconds. Next, a PET release sheet was bonded to the pressure-sensitive adhesive surface in which zirconia (ZrO ₂ ) particles were dispersed to obtain a pressure-sensitive adhesive sheet. The refractive index of the surface of the inorganic particle-containing region was 1.68, and the area ratio (surface coverage) occupied by the zirconia particles was 93%. Moreover, the element ratio of Zr / C in the inorganic particle containing area | region of the obtained adhesive layer was 0.07. When the depth profile of the element ratio of the obtained pressure-sensitive adhesive layer was obtained, the element ratio of Zr did not have a peak in the depth direction, and it went from the pressure-sensitive adhesive layer surface (the surface containing the inorganic particles) to the inside of the pressure-sensitive adhesive layer. It was found that it decreased monotonously. The reduction rate was 0.20 atomic% / nm (thickness was converted to SiO ₂ ). Moreover, the metal element ratio of the inorganic particles in the base pressure-sensitive adhesive region was 0 atomic%. In addition, the average primary particle diameter of the zirconia particles was measured by TEM observation.

  A thermosetting resin composition containing a melamine resin: alkyd resin: organosilane condensate in a weight ratio of 2: 2: 1 in terms of solid content was diluted with methyl ethyl ketone so that the solid content concentration was 8% by weight. This solution was applied to one main surface of a transparent film substrate (refractive index: 1.65) made of a PET film (trade name: Lumirror, manufactured by Toray Industries, Inc.) having a thickness of 50 μm, and heated at 150 ° C. for 2 minutes. Curing was performed to form an optical adjustment layer having a thickness of 30 nm and a refractive index of 1.54.

  On the surface of the refractive index adjusting layer, an indium tin oxide layer (ITO layer, refractive index: 1.90) having a thickness of 21 nm was laminated as a transparent conductive layer. Subsequently, the obtained transparent conductor was heated at 150 ° C. to crystallize the ITO layer. When the resistance value of the heated transparent conductor was measured by the four-terminal method, it was 140Ω / □. A polyimide adhesive tape was attached to the ITO layer where the ITO layer was desired to remain, and the ITO layer was etched by immersion in 1 mol / L hydrochloric acid for 2 minutes. Thereafter, the transparent conductor was sufficiently washed with ion-exchanged water, dried at 120 ° C. for 10 minutes, and then the polyimide adhesive tape was peeled off to obtain a transparent conductor on which the ITO layer was patterned. The transparent conductor and the pressure-sensitive adhesive layer were laminated so that the patterned ITO layer surface of the obtained transparent conductor was in contact with the inorganic particle-containing region of the pressure-sensitive adhesive layer.

Example 2
A laminate of the transparent conductor and the pressure-sensitive adhesive layer was produced in the same manner as in Example 1 except that the film thickness of the inorganic particle-containing region of the pressure-sensitive adhesive layer was 500 nm.

Example 3
Adhering to the transparent conductor in the same manner as in Example 1 except that the thickness of the transparent conductive layer is an indium tin oxide layer (ITO layer, refractive index: 1.90, resistance value: 80Ω / □) of 30 nm. A laminate of the agent layer was produced.

Example 4
A UV curable acrylic resin (hard coat layer forming coating solution) is applied on both sides of a transparent film substrate (refractive index: 1.65) made of a PET film (trade name: Lumirror, manufactured by Toray Industries, Inc.) having a thickness of 50 μm. Refractive index: 1.52) was applied so that the thickness after drying was 2.0 μm, and the coating film was dried by heating at 80 ° C. for 3 minutes. Then, the hard coat layer (refractive index: 1.52) was formed by irradiating the ultraviolet ray of the integrated light quantity 200mJ / cm < ² > with the high pressure mercury lamp (PET film which has a hard coat layer).

Subsequently, with respect to 100 parts of UV curable acrylic resin (refractive index: 1.52), zirconium oxide nanoparticles (average particle size: 10 nm) were adjusted to have a refractive index of 1.65. A layer forming coating solution was prepared. Next, the coating liquid for forming a high refractive index layer is applied to the surface of one hard coat layer of a PET film having a hard coat layer so that the thickness after drying is 30 nm, and heated at 80 ° C. for 3 minutes. Thus, the coating film was dried. Thereafter, an optical adjustment layer (high refractive index layer, refractive index: 1.65) was formed by irradiating ultraviolet rays with an integrated light quantity of 200 mJ / cm ² with a high-pressure mercury lamp. The metal element to carbon element ratio (metal element / carbon) in the optical adjustment layer was 0.41.

A coating solution for forming a low refractive index layer was prepared by adjusting nanosilica particles (average particle size: 15 nm) to an ultraviolet curable acrylic resin (refractive index: 1.52) so that the refractive index was 1.45. The coating liquid is formed by applying the coating liquid for forming the low refractive index layer to the surface of the formed optical adjustment layer (high refractive index layer) so that the thickness after drying becomes 40 nm and heating at 80 ° C. for 3 minutes. Dried. Then, the low refractive index layer (refractive index: 1.45) was formed by irradiating the ultraviolet-ray of the integrated light quantity 200mJ / cm < ² > with a high pressure mercury lamp. The ratio of (inorganic atom / carbon atom) in the low refractive index layer was 0.32.

The laminated film (hard coat layer / PET film / hard coat layer / high refractive index layer / low refractive index layer) was mounted on a DC magnetron sputtering apparatus and wound up while closely contacting and running on a heated film forming roll. While the laminated film was running, the degree of vacuum in the apparatus was set to 1 × 10 ⁻⁴ Pa (degassing process) by the exhaust apparatus provided in the DC magnetron sputtering apparatus.

  Subsequently, ITO was laminated, crystallized, patterned, and laminated in the same manner as in Example 1.

Comparative Example 1
In Example 3, it was the same as Example 3 except that the pressure-sensitive adhesive layer A obtained in Production Example 1 was used as a pressure-sensitive adhesive sheet (that is, the pressure-sensitive adhesive layer of Comparative Example 1 did not have an inorganic particle-containing region). Thus, a laminate of a transparent conductor and an adhesive layer was produced.

Comparative Example 2
In Example 4, the same as Example 4 except that the pressure-sensitive adhesive layer A obtained in Production Example 1 was used as a pressure-sensitive adhesive sheet (that is, the pressure-sensitive adhesive layer of Comparative Example 2 does not have an inorganic particle-containing region). Thus, a laminate of a transparent conductor and an adhesive layer was produced.

  The following evaluation was performed about the laminated body obtained by the Example and the comparative example. The evaluation results are shown in Table 1 and the drawings.

<Measurement of resistance value of transparent conductive layer>
The transparent conductive film was heat-treated at 150 ° C. to crystallize the transparent conductive layer, and then the surface resistance (Ω / □) of the transparent conductive layer was measured by a four-terminal method according to JIS K7194 (1994).

<Average surface refractive index of the inorganic particle-containing region>
The average surface refractive index of the pressure-sensitive adhesive sheets obtained in Examples and Comparative Examples was measured for the refractive index at sodium D line (589 nm) using a spectroscopic ellipsometer (trade name: EC-400, manufactured by JA Woollam). In the pressure-sensitive adhesive sheets of Examples and Comparative Examples, the average refractive index of the surface on which the particles were applied was measured in a state where the release sheets on both sides were peeled off and the blackboard was bonded to the surface on which the particles were not applied. In the pressure-sensitive adhesive sheet of the comparative example, the average refractive index on the surface of the pressure-sensitive adhesive layer was measured in a state where both the release sheets were peeled off and a blackboard was bonded to one surface.

<Measurement of thickness of inorganic particle-containing region>
The cross section in the depth direction of the pressure-sensitive adhesive layer was adjusted, and TEM observation was performed. Measurement of the thickness of the inorganic particle-containing region was measured from the obtained TEM image. The thickness of the inorganic particle-containing region is the average value of the unevenness at the interface between the base pressure-sensitive adhesive layer and the inorganic particle-containing region. If it is difficult to determine the interface with the base pressure-sensitive adhesive layer, the surface TEM image is converted into image processing software. The binarized image processing was performed with (ImageJ), and the depth of the region where 90% of the nanoparticles were present was defined as the thickness of the adjustment layer.

<Measuring method of inorganic substance (inorganic atom) content in first optical adjustment layer>
An X-ray photoelectron spectroscopy (ESCA) was carried out under the following conditions to obtain a depth profile.
Measuring device: Quantera SMX, manufactured by ULVAC-PHI X-ray source: Monochrome AlKα
X Ray setting: 200 μmφ, 15 kV, 26 W
Photoelectron extraction angle: 45 ° to the sample surface
Charge neutralization condition: combined use of electron neutralizing gun and Ar ion gun (neutralization mode) Binding energy: Peak derived from CC bond in C1s spectrum is corrected to 285.0 eV Acceleration voltage of Ar ion gun: 1 kV
Etching rate of Ar ion gun: 2 nm / min (SiO ₂ conversion)
Etching area: 2mm x 2mm
In the region corresponding to the first optical adjustment layer of the depth profile, the depth at which the element ratio of inorganic atoms (element ratio of inorganic atoms to all elements (excluding H and He) included in the optical adjustment layer) is the highest The number ratio of (inorganic atom / carbon atom) was adopted here.

<Content of metal element in the inorganic particle-containing region>
X-ray photoelectron spectroscopy (ESCA) was performed under the following conditions to obtain a depth profile of the element ratio in the depth direction.
Measuring device: Quantera SMX, manufactured by ULVAC-PHI, Inc. X-ray source: Monochrome AlKα
X Ray setting: 200 μmφ, 15 kV, 26 W
Photoelectron extraction angle: 45 ° to the sample surface
Charge neutralization condition: combined use of electron neutralizing gun and Ar ion gun (neutralization mode) Binding energy: Peak derived from CC bond in C1s spectrum is corrected to 285.0 eV Acceleration voltage of Ar ion gun: 1 kV
Etching rate of Ar ion gun: 2 nm / min (SiO ₂ conversion)
Etching area: 2mm x 2mm
In the depth range corresponding to the inorganic particle-containing region in the obtained depth profile (that is, the depth range in which the element ratio of the metal element is 1 atomic% or more), all the elements of the metal element (however, excluding H and He) The element ratio (atomic%) to carbon is integrated, and the element ratio (atomic%) to all elements of carbon element (excluding H and He) is integrated, and the ratio of the integrated value of metal element to the integrated value of carbon Calculated as

<Measurement method of inorganic particle content in base adhesive layer region>
The metal element ratio of the inorganic particles relative to all the elements (excluding H and He) contained in the base pressure-sensitive adhesive layer region was calculated in the same manner as in the above <content ratio of metal element in the inorganic particle-containing region>.

<Area ratio occupied by inorganic particles (surface coverage)>
The surface of the adhesive layer containing the inorganic particles was observed using an FE-SEM at an acceleration voltage of 2 kV, an observation magnification of 500 times, 2,000 times, and 5,000 times. By performing binarized image processing on the obtained surface SEM image with image processing software (ImageJ), the area ratio (%) occupied by the inorganic particles as the area with respect to the entire area in a rectangular region having a long side of 23 μm and a short side of 18 μm is obtained. Asked.

<Measurement of ΔY value of reflectance>
Black tape (absorber) on the transparent base material surface (hard coat layer surface if it has a hard coat layer) of the transparent conductor (unetched) before being bonded to the adhesive layer obtained in Examples and Comparative Examples ) So that reflection from the back surface is not measured. Then, the adhesive layer used by each Example and the comparative example was bonded on the transparent conductive layer which has not been etched, and the laminated body was produced. At that time, in the case where the pressure-sensitive adhesive layer has an inorganic particle-containing region, bonding was performed so that the transparent conductive layer and the inorganic particle-containing region were in contact (pattern part sample). Moreover, the transparent conductor (unetched treatment) in a state before being bonded to the pressure-sensitive adhesive layer obtained in Examples and Comparative Examples was etched at 50 ° C. with 10% by weight hydrochloric acid (HCl) to form an optical adjustment layer. Prepare the exposed non-patterned part sample, and paste the black tape on the transparent substrate surface, and then paste the adhesive layer used in each example and comparative example on the exposed optical adjustment layer. A laminate was produced. At that time, in the case where the pressure-sensitive adhesive layer had an inorganic particle-containing region, bonding was performed so that the optical adjustment layer and the inorganic particle-containing region were in contact (non-pattern part sample).
Thereafter, the reflectance of each pattern portion sample and non-pattern portion sample from the surface of the pressure-sensitive adhesive layer using a reflectance measuring machine (product name: U-4100 (+ integrating sphere unit), manufactured by Hitachi, Ltd.). The spectrum was measured. The measurement conditions of the reflectance spectrum are as follows.
Data mode:% R
Measurement range: 380 nm to 780 nm
Scan speed: 600 nm / min Slit: 4 nm
Sampling interval: 5 nm
Light source: D65
Field of view: 2 ° C. field of view The reflectance Y (described in JIS Z 8701) of each of the pattern portion sample and the non-pattern portion sample in the XYZ coordinates was calculated from the spectrum, and ΔY was determined by calculating the difference between them.

<Color difference (ΔE) measurement>
First, a reflection spectrum was measured in the same manner as in <Measurement of ΔY value of reflectance>. Thereafter, the L * value, a * value, and b * value defined in JIS Z 8729 were calculated from the reflection spectrum, and the color differences ΔL *, Δa *, and Δb * were determined and substituted into the following equations.
ΔE = {(ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² } ^0.5

<Pattern appearance>
The transparent conductor (unetched treatment) in a state before being bonded to the pressure-sensitive adhesive layer obtained in Examples and Comparative Examples was cut out to 5 cm × 10 cm, and the surface of the transparent conductor of the transparent conductor was short of the transparent conductor. Along the side direction, a polyimide tape having a width of 1 mm was applied in a stripe shape at intervals of 2 mm and impregnated with hydrochloric acid at 50 ° C. and 10% by mass for 5 minutes. Thus, a wiring pattern having a stripe-shaped pattern portion was formed. Thereafter, the polyimide tape was peeled off and a transparent base material made of a transparent conductor was pasted on a blackboard to prepare a sample for wiring pattern visibility evaluation.
Each adhesive layer used in the examples and comparative examples was bonded onto the patterned transparent conductive layer of the prepared sample for wiring pattern visibility evaluation to prepare a laminate. At that time, when the pressure-sensitive adhesive layer had an inorganic particle-containing region, the bonding was performed so that the surface on the inorganic particle-containing region side and the surface on the transparent conductive layer side were in contact. Thereafter, the wiring pattern was observed, and visual suppression (pattern appearance) was evaluated based on the following criteria.
A: The pattern of the conductive layer was hardly visible, and the pattern was hardly visible even when the observation angle was changed.
A: The pattern of the conductive layer is hardly visible, but the pattern may be visible by changing the observation angle.
X: The pattern can always be confirmed by changing the observation angle.

DESCRIPTION OF SYMBOLS 1 Laminated body 2 Transparent base material 3 1st optical adjustment layer 3 '2nd optical adjustment layer 4 Patterned transparent conductive layer 5 Transparent conductor 6 Inorganic particle containing area | region (refractive index adjustment layer)
7 Base adhesive region 8 Adhesive layer 9 Inorganic particles 10 Dispersion

Claims (9)

A transparent substrate, a first optical adjustment layer and a transparent conductor having a patterned transparent conductive layer in this order, and a laminate having a pressure-sensitive adhesive layer formed on the transparent conductive layer of the transparent conductor,
The pressure-sensitive adhesive layer includes a base pressure-sensitive adhesive region essentially formed of the pressure-sensitive adhesive composition from one main surface of the pressure-sensitive adhesive layer to the thickness direction, and inorganic particles from the other main surface to the thickness direction. Having an inorganic particle-containing region,
The pressure-sensitive adhesive layer and the transparent conductor are laminated so that the inorganic particle-containing region of the pressure-sensitive adhesive layer and the transparent conductive layer of the transparent conductor are in contact with each other,
A laminate having a metal element to carbon element ratio (metal element / carbon) contained in the inorganic particle-containing region of 0.01 to 0.2.   2. The laminate according to claim 1, wherein a refractive index of the transparent substrate is larger than a refractive index of the first optical adjustment layer and lower than a refractive index of the transparent conductive layer.   A second optical adjustment layer having a refractive index higher than the refractive index of the first optical adjustment layer and lower than the refractive index of the transparent conductive layer is further provided between the first optical adjustment layer and the transparent substrate. The laminate according to claim 1 or 2, wherein:   The laminated body according to any one of claims 1 to 3, wherein a refractive index of a surface of the inorganic particle-containing region on a side in contact with the transparent conductive layer is 1.47 to 1.74.   The refractive index of the inorganic particle-containing region is continuously reduced from the side in contact with the transparent conductive layer of the inorganic particle-containing region toward the other side. The laminated body as described in.   The laminate according to claim 1, wherein the inorganic particles include zirconia particles.   The average thickness of the said inorganic particle containing area | region is 20 nm-600 nm, The laminated body in any one of Claims 1-6 characterized by the above-mentioned.   The laminate according to any one of claims 1 to 7, wherein the transparent conductive layer has a surface resistance value of 100 Ω / □ or less. A step of preparing a transparent conductor having a transparent substrate, a first optical adjustment layer and a transparent conductive layer in this order;
A dispersion containing inorganic particles is applied to one main surface of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition, and the inorganic particles contained in the dispersion are thickened from one main surface of the pressure-sensitive adhesive layer. Infiltrating in the direction to form a base pressure-sensitive adhesive region essentially formed by the pressure-sensitive adhesive composition, and an inorganic particle-containing region,
Bonding the pressure-sensitive adhesive layer and the transparent conductor so that the inorganic particle-containing region of the pressure-sensitive adhesive layer and the transparent conductive layer of the transparent conductor are in contact with each other;
The layered product according to any one of claims 1 to 8, wherein an element ratio of metal element to carbon (metal element / carbon) contained in the inorganic particle-containing region is 0.01 to 0.2. Manufacturing method.

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