CN113508315A

CN113508315A - Laminate and image display device

Info

Publication number: CN113508315A
Application number: CN202080017911.9A
Authority: CN
Inventors: 朴一雨
Original assignee: Sumitomo Chemical Co Ltd
Current assignee: Sumitomo Chemical Co Ltd
Priority date: 2019-03-04
Filing date: 2020-02-10
Publication date: 2021-10-15
Also published as: JP2020144455A; WO2020179371A1; TW202105147A; KR20210134669A

Abstract

The invention provides a laminate which is provided with a polarizing layer, a coloring layer and a touch sensor layer, and when an image display device in a power-off state is observed from a visible side, the difference between a display area and a non-display area is not obvious. The invention provides a laminate, which sequentially comprises a polarizing layer, an adhesive layer and a touch sensor layer, wherein the touch sensor layer comprises a wiring and a coloring layer, the laminate can be divided into a display area and a non-display area in a plan view, and the coloring layer is arranged in the non-display area and is arranged on one side closer to the polarizing layer than the wiring.

Description

Laminate and image display device

Technical Field

The present invention relates to a laminate and an image display device.

Background

Patent document 1 describes a touch panel in which a colored layer is provided on a touch sensor layer. The colored layer may have not only a design function of the image display device but also a function of forming a shielding layer in the non-display region.

Patent document 2 describes a touch screen panel having a touch panel with a front surface to be touched, a laminate including transparent electrodes, and a display substrate, and describes forming a concave portion in the touch panel or the display substrate so as to fit a printed layer.

Documents of the prior art

Patent document

Patent document 1 Korean laid-open patent application No. 10-2019-

Patent document 2 Korean laid-open patent application No. 10-2013-0141780

Disclosure of Invention

The invention aims to provide a laminate which is provided with a polarizing layer, a coloring layer and a touch sensor layer, and when an image display device in a power-off state is observed from a visible side, the color difference between a display area and a non-display area is not obvious.

The invention provides the following laminated body and image display device.

[1] A laminate comprising a polarizing layer, an adhesive layer and a touch sensor layer in this order,

the touch sensor layer includes a wiring and a coloring layer,

the laminate is divided into a display region and a non-display region in a plan view,

the colored layer is provided in the non-display region and is disposed on a side closer to the polarizing layer than the wiring.

[2]According to [1]The laminate, wherein an absolute value Δ a of a color difference between the display region and the non-display region when viewed from the polarizing layer side^*And Δ b^*All are 0.3 or less.

[3] The laminate according to [1] or [2], wherein the colored layer contains carbon black.

[4] The laminate according to any one of [1] to [3], wherein a height difference between the display region and the non-display region on an outermost surface when viewed from the touch sensor layer side is 3 μm or less.

[5] The laminate according to any one of [1] to [4], wherein the colored layer has a thickness of 2 μm or less and an optical density of 4 or more.

[6] The laminate according to any one of [1] to [5], further comprising an organic EL display element on an outermost surface on the side of the touch sensor layer.

[7] An image display device comprising the laminate according to any one of [1] to [6 ].

[8] A method for producing the laminate according to any one of [1] to [6], comprising:

a step of preparing a polarizing layer by using a polarizing film,

a process of preparing a touch sensor layer,

bonding the polarizing layer and the touch sensor layer via a bonding layer;

the step of preparing the touch sensor layer includes a colored layer forming step of forming a colored layer by photolithography.

According to the present invention, a laminate including a polarizing layer, a coloring layer, and a touch sensor layer can be provided, and when the image display device in a power-off state is viewed from the visible side, color difference between a display region and a non-display region is not conspicuous. A user of the image display device including the laminate can feel that the display area is enlarged because the non-display area looks like the display area.

Drawings

Fig. 1 is a schematic cross-sectional view showing a laminate according to an embodiment of the present invention.

Fig. 2 is a plan view of the laminate as viewed from the polarizing layer side.

Fig. 3 is a schematic cross-sectional view showing a laminate according to an embodiment of the present invention.

Fig. 4 is a schematic diagram schematically illustrating the description of the position accuracy.

Fig. 5 is a schematic cross-sectional view schematically showing a method for producing a laminate.

Fig. 6 is a schematic cross-sectional view schematically showing a method for producing a laminate.

Fig. 7 is a schematic cross-sectional view schematically showing a method for producing a laminate.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the embodiments below. In all the drawings below, the scale of each component shown in the drawings is appropriately adjusted and displayed in order to facilitate understanding of each component, and the scale of each component does not necessarily coincide with the scale of an actual component.

[ laminate ]

Fig. 1 is a schematic cross-sectional view of a laminate according to an embodiment of the present invention. The laminate 100 of the present embodiment includes a polarizing layer 101, a bonding layer 102, and a touch sensor layer 103 in this order from the visible side. The touch sensor layer 103 includes a wiring 104 and a coloring layer 105. The laminate 100 is divided into a display region a and a non-display region B in a plan view, and the colored layer 105 is provided in the non-display region B and is disposed closer to the polarizing layer 101 than the wiring 104. The wiring 104 may be provided in the non-display region B. In the present specification, a planar view means a view from the thickness direction of the layer.

According to the research of the inventor, the following steps are found: by providing the touch sensor layer 103 with the wiring 104 and the colored layer 105, and providing the colored layer 105 in the non-display region B and disposing the non-display region B closer to the polarizing layer 101 than the wiring 104, in the image display device including the laminate 100 such that the polarizing layer 101 is on the visible side, when the image display device in the power-off state is viewed from the visible side, the color difference between the display region and the non-display region (hereinafter also referred to as "difference in visibility") becomes less noticeable. In the case where the colored layer is formed on the surface of the polarizing layer on the front panel side or on the surface of the polarizing layer side, the user of the image display device can directly recognize the color of the colored layer, and therefore the difference between the color of the colored layer and the color of the polarizing layer is likely to be conspicuous. In addition, in the case where the colored layer is formed on the surface of the polarizing layer on the touch sensor layer side, the user of the image display device can recognize the smooth surface of the colored layer, and therefore, the difference between the color of the colored layer and the color of the polarizing layer is easily conspicuous due to the influence of reflection. On the other hand, in the laminate of the present invention, the touch sensor layer having the colored layer is disposed on the side opposite to the front panel side with respect to the polarizing layer. The user of the image display device can see the coloring layer through the polarizing layer.

Further, the colored layer is disposed apart from the polarizing layer. In this case, the color of the colored layer is close to the color of the polarizing layer, and thus the difference in visibility is considered to be alleviated. A user of an image display device including the laminate of the present invention can feel that the display area is larger than the actual size because the non-display area looks like the display area.

Fig. 2 is a plan view of the laminate 100 viewed from the polarizing layer 101 side. From the viewpoint of reducing the difference in visibility, the color tone a of the display region a and the non-display region B when viewed from the polarizing layer side^*And b^*Absolute value Δ a of the difference (hereinafter also referred to as color difference)^*And Δ b^*For example, each may be 0.3 or less. Reducing color difference from display area A to non-display area BFrom the viewpoint of (1), the colored layer 101 may be black. This is because the polarizing layer is often manufactured so that its color is neutral gray. The colored layer 101 preferably contains carbon black from the viewpoint of reducing color difference between the display region a and the non-display region B. The color difference is preferably 0.2 or less, and more preferably 0.15 or less. Δ a^*And Δ b^*Is L of the display area A^*a^*b^*Coordinate a in the color space (CIE 1976)^* _A、b^* _AL of the NAND display region B^*a^*b^*Coordinate a in the color space (CIE 1976)^* _B、b^* _BThe absolute value of the difference (c) can be obtained by the following equation.

Δa^*＝|a^* _A-a^* _B|

Δb^*＝|b^* _A-b^* _B|

The laminate 100 preferably has: the difference in height between the display region and the non-display region on the outermost surface when viewed from the touch sensor layer 103 side (hereinafter also simply referred to as "difference in height") is 3 μm or less. When the step is 3 μm or less, generation of bubbles due to the step can be suppressed when the touch sensor layer of the laminate is bonded to the display portion, and the lamination with the organic EL display element tends to be favorable. From the viewpoint of preventing the occurrence of defects in the bonding step, the step is preferably 2 μm or less, more preferably 1 μm or less, and still more preferably 0.5 μm or less.

In order to make the height difference 3 μm or less, for example, the thickness of the colored layer 105 is made 2 μm or less. In order to reduce the height difference, the thickness of the colored layer 105 may be reduced. On the other hand, if the thickness of the colored layer 105 is made thin, the optical density is lowered, and the shading property tends to be impaired. Therefore, the present inventors have found that the height difference can be made 3 μm or less without impairing the shielding property of the colored layer 105 from the wiring 104 by setting the thickness of the colored layer 105 to 2 μm or less and setting the optical density to 4 or more. The thickness of the colored layer 105 is preferably 2 μm or less, and the optical density is preferably 4 or more. The optical density may be 7 or less, or 6 or less. The optical density of the colored layer can be measured by an optical density measuring instrument, specifically, by the method described in the examples described later.

In order to adjust the thickness and optical density of the colored layer 105 to the above ranges, for example, a method of forming the colored layer 105 by photolithography using the composition for forming a colored layer is exemplified. This is because a coloring layer-forming composition having a larger colorant content can be used more easily by photolithography than by printing, and the optical density per unit film thickness of the coloring layer 105 can be increased more easily.

The thickness of the laminate 100 is not particularly limited, and may be, for example, 20 to 1000 μm, preferably 25 to 500 μm, and more preferably 30 to 300 μm, since it varies depending on the function required for the laminate 100, the application of the laminate 100, and the like.

The shape of the laminate 100 in a plan view may be, for example, a square shape, preferably a square shape having long sides and short sides, and more preferably a rectangle. When the shape of the laminate 100 in a plan view is rectangular, the length of the long side may be, for example, 10mm to 1400mm, and preferably 50mm to 600 mm. The length of the short side may be, for example, 5mm to 800mm, preferably 30mm to 500mm, and more preferably 50mm to 300 mm.

When the shape of the laminate 100 in a plan view is a square shape, the lengths of the sides in the layers constituting the laminate 100 may be the same. Each layer constituting the laminate 100 may be subjected to R-processing at the corner portion and may be subjected to notch processing or punching at the end portion.

The laminate 100 is preferably bendable. Bendable means that bending with a bending radius of 2.5mm is possible. More preferably, the laminate 100 does not crack even when the number of times of bending is 1 ten thousand with a bending radius of 2.5mm of the inner surface of the laminate 100.

The laminate 100 may further have a front panel on the outermost surface on the polarizing layer 101 side. The laminate 100 may further have an organic EL display element on the outermost surface on the touch sensor 103 side.

Fig. 3 is a schematic cross-sectional view of a laminate according to another embodiment of the present invention. The laminate 200 of the present embodiment includes, in order from the visible side, a front panel 201, a bonding layer 202, a polarizing layer 101, a bonding layer 102, a touch sensor layer 103, a bonding layer 203, and an organic EL display element 204. The touch sensor layer 103 includes a wiring 104 and a coloring layer 105, and is laminated on the base material layer 111.

The laminate 100 can be used for an image display device, for example. The image display device is not particularly limited, and examples thereof include an organic electroluminescence (organic EL) display device, an inorganic electroluminescence (inorganic EL) display device, a liquid crystal display device, and an electroluminescence display device. In the case where the laminate 100 has flexibility, the laminate 100 is preferably used for a flexible display.

[ polarizing layer ]

The polarizing layer 101 may be a linear polarizing layer, or a combination of a linear polarizing layer and a phase difference layer. Examples of the linearly polarizing layer include a stretched film or a stretched layer adsorbing a dichroic dye, and a film obtained by applying and curing a composition containing a dichroic dye and a polymerizable compound as a polarizer. As the dichroic dye, specifically, iodine or a dichroic organic dye can be used. The dichroic organic dye includes a dichroic direct dye composed of a disazo compound such as c.i. direct red 39, and a dichroic direct dye composed of a compound such as trisazo or tetrazo.

Examples of the film obtained by applying and curing a composition containing a dichroic dye and a polymerizable compound include a film containing a cured product of a polymerizable liquid crystal compound, such as a layer obtained by applying and curing a composition containing a dichroic dye having liquid crystallinity or a composition containing a dichroic dye and a polymerizable liquid crystal.

A film obtained by applying and curing a composition containing a dichroic dye and a polymerizable liquid crystal is preferable because it is not limited in the bending direction as compared with a stretched film or a stretched layer in which a dichroic dye is adsorbed. Therefore, in order to obtain a laminate in which the number of times of bending that does not cause cracking when the repeated bending is performed in at least one direction in the plane and a direction perpendicular thereto, and further in any direction in the plane is within the above range, a film obtained by applying and curing a composition containing a dichroic dye and a polymerizable liquid crystal as a polarizer is preferably contained as the linear polarizing layer.

(1) Linear polarizing layer having polarizer as stretched film or stretched layer

A polarizer as a stretched film for adsorbing a dichroic dye can be generally produced through the following steps: a step of uniaxially stretching a polyvinyl alcohol resin film; a step of dyeing a polyvinyl alcohol resin film with a dichroic dye to adsorb the dichroic dye; treating the polyvinyl alcohol resin film having the dichroic dye adsorbed thereon with an aqueous boric acid solution; and a step of washing with water after the treatment with the boric acid aqueous solution. The polarizer may be used as a linear polarizing layer as it is, or may be used as a linear polarizing layer after a transparent protective film is attached to one or both surfaces thereof. The thickness of the polarizer is preferably 2 μm to 40 μm.

The polyvinyl alcohol resin can be obtained by saponifying a polyvinyl acetate resin. As the polyvinyl acetate-based resin, in addition to polyvinyl acetate which is a homopolymer of vinyl acetate, a copolymer of vinyl acetate and another monomer copolymerizable therewith may be used. Examples of the other monomer copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and (meth) acrylamides having an ammonium group.

The saponification degree of the polyvinyl alcohol resin is usually 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol resin may be modified, and for example, polyvinyl formal or polyvinyl acetal modified with aldehydes may be used. The polymerization degree of the polyvinyl alcohol resin is usually 1000 to 10000, preferably 1500 to 5000.

The polarizer as the stretched layer to which the dichroic dye is adsorbed can be generally produced through the following steps: a step of applying a coating liquid containing the polyvinyl alcohol resin onto a base film; a step of uniaxially stretching the obtained laminated film; dyeing the polyvinyl alcohol resin layer of the uniaxially stretched laminated film with a dichroic dye, and adsorbing the dichroic dye to form a polarizer; treating the film having the dichroic dye adsorbed thereon with an aqueous boric acid solution; and a step of washing with water after the treatment with the boric acid aqueous solution.

The substrate film may be peeled off from the polarizer as necessary. The material and thickness of the base film may be the same as those of the thermoplastic resin film described later.

The polarizer as the stretched film or the stretched layer may be combined with the optical laminate in a form in which a thermoplastic resin film is bonded to one surface or both surfaces thereof. The thermoplastic resin film can function as a protective film for polarizers or a retardation film.

The thermoplastic resin film may be formed of a polyolefin resin such as a chain polyolefin resin (e.g., a polypropylene resin) or a cyclic polyolefin resin (e.g., a norbornene resin); cellulose resins such as triacetyl cellulose; polyester resins such as polyethylene terephthalate, polyethylene naphthalate and polybutylene terephthalate; a polycarbonate-based resin; (meth) acrylic resins; or a mixture thereof, and the like.

From the viewpoint of thinning, the thickness of the thermoplastic resin film is usually 300 μm or less, preferably 200 μm or less, more preferably 100 μm or less, further preferably 80 μm or less, further preferably 60 μm or less, and further usually 5 μm or more, preferably 20 μm or more.

The thermoplastic resin film may or may not have a retardation.

The thermoplastic resin film may be bonded to the polarizer using an adhesive layer, for example.

(2) A linear polarizing layer comprising a polarizer formed from a film obtained by coating and curing a composition containing a dichroic dye and a polymerizable compound

Examples of the film obtained by applying and curing a composition containing a dichroic dye and a polymerizable compound include a film containing a cured product of a polymerizable liquid crystal compound, such as a layer obtained by applying and curing a composition containing a liquid crystal-polymerizable dichroic dye or a composition containing a dichroic dye and a polymerizable liquid crystal onto a base film (or an alignment film formed on a base film).

The film may be peeled off the substrate or used as a linear polarizing layer together with the substrate.

The material and thickness of the base film may be the same as those of the thermoplastic resin film described above.

A film obtained by applying and curing a composition containing a dichroic dye and a polymerizable compound may be combined with a laminate in a form in which a thermoplastic resin film is laminated on one surface or both surfaces thereof. As the thermoplastic resin film, the same thermoplastic resin film as that used for a polarizer as a stretched film or a stretched layer can be used.

Specific examples of the film obtained by applying and curing a composition containing a dichroic dye and a polymerizable compound include films described in japanese patent laid-open nos. 2013-37353 and 2013-33249.

The thickness of the film obtained by applying and curing the composition containing the dichroic dye and the polymerizable compound is usually 10 μm or less, preferably 0.5 to 8 μm, and more preferably 1 to5 μm.

The thickness of the polarizing layer 101 is, for example, 2 μm to 100 μm, preferably 10 μm to 60 μm.

The polarizing layer 101 may further include a phase difference layer. The retardation layer may include 1 or 2 or more retardation layers. The retardation layer may be a positive A plate such as a λ/4 plate or a λ/2 plate, or a positive C plate. The retardation layer may be formed of a resin film exemplified as a material of the protective film, or may be formed of a layer obtained by curing a polymerizable liquid crystal compound. The polarizing layer 101 may further include an alignment film, a substrate film.

If the linear polarizing layer and the retardation layer are disposed so that the absorption axis of the linear polarizing layer and the slow axis of the retardation layer are at a predetermined angle, the polarizing layer 101 has an antireflection function, that is, can function as a circular polarizing plate. In the case where the phase difference layer includes a λ/4 plate, the angle of the absorption axis of the linear polarizing layer with the slow axis of the λ/4 plate may be 45 ° ± 10 °.

When the polarizing layer 101 includes a retardation layer, the polarizing layer 101 and the retardation layer may be bonded to each other through a bonding layer described later. The thickness of the adhesive layer may be, for example, 0.5 to 25 μm, preferably 1 to 25 μm.

By providing the laminate 100 with the polarizing layer 101 as a circularly polarizing plate, reflection of external light can be prevented. The thickness of the circularly polarizing plate is, for example, 10 to 200. mu.m, preferably 10 to 100. mu.m.

[ adhesive layer ]

The adhesive layer 102 is a layer interposed between the polarizing layer 101 and the touch sensor layer 103, and may be, for example, an adhesive layer or an adhesive layer. The adhesive layer 102 may be a layer for adhering a polarizing layer and the touch sensor layer 103, and may be a layer for adhering a front panel and a polarizing plate, which will be described later. The adhesive layer 102 is preferably an adhesive layer from the viewpoint of absorbing the difference in height of the colored layer 105. The laminate 100 may have 1 bonding layer, or may have 2 or more. In addition, 1 adhesive layer can be composed of 1 or 2 or more layers. When the optical laminate includes a plurality of bonding layers 20, the plurality of bonding layers may be the same type or different types.

The pressure-sensitive adhesive layer may be composed of a pressure-sensitive adhesive composition containing a resin such as a (meth) acrylic, rubber, urethane, ester, silicone, or polyvinyl ether resin as a main component. Among them, preferred is an adhesive composition containing a (meth) acrylic resin as a base polymer, which is excellent in transparency, weather resistance, heat resistance and the like. The adhesive composition may be an active energy ray-curable adhesive composition or a thermosetting adhesive composition.

As the (meth) acrylic resin (base polymer) used in the adhesive composition, for example, a polymer or copolymer in which 1 or 2 or more kinds of (meth) acrylic esters such as butyl (meth) acrylate, ethyl (meth) acrylate, isooctyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate are used as monomers is preferably used. In the base polymer, it is preferable to copolymerize a polar monomer. Examples of the polar monomer include monomers having a carboxyl group, a hydroxyl group, an amide group, an amino group, an epoxy group, and the like, such as (meth) acrylic acid, 2-hydroxypropyl (meth) acrylate, hydroxyethyl (meth) acrylate, (meth) acrylamide, N-dimethylaminoethyl (meth) acrylate, and glycidyl (meth) acrylate.

The adhesive composition may comprise only the above-mentioned base polymer, but usually contains a crosslinking agent. Examples of the crosslinking agent include a crosslinking agent which is a metal ion having a valence of 2 or more and forms a metal carboxylate salt with a carboxyl group; a crosslinking agent which is a polyamine compound and forms an amide bond with a carboxyl group; a crosslinking agent in the polyepoxy compound or the polyol and forming an ester bond with the carboxyl group; a polyisocyanate compound and a crosslinking agent forming an amide bond with a carboxyl group. Among them, polyisocyanate compounds are preferable.

The active energy ray-curable adhesive composition is an adhesive composition having a property of being cured by irradiation with an active energy ray such as an ultraviolet ray or an electron beam, and also having a property of having an adhesive property before the irradiation with the active energy ray, thereby being closely adhered to an adherend such as a film, and being cured by the irradiation with the active energy ray to adjust the adhesion force. The active energy ray-curable adhesive composition is preferably an ultraviolet-curable adhesive composition. The active energy ray-curable adhesive composition contains an active energy ray-polymerizable compound in addition to a base polymer and a crosslinking agent. Further, a photopolymerization initiator, a photosensitizer, and the like may be contained as necessary.

The binder composition may contain additives such as fine particles, beads (resin beads, glass beads, and the like), glass fibers, resins other than the base polymer, adhesion-imparting agents, fillers (metal powders, other inorganic powders, and the like), antioxidants, ultraviolet absorbers, dyes, pigments, colorants, antifoaming agents, anticorrosion agents, and photopolymerization initiators, which impart light scattering properties.

The organic solvent diluted solution of the adhesive composition may be applied to a substrate and dried to form the adhesive composition. When an active energy ray-curable pressure-sensitive adhesive composition is used, a cured product having a desired degree of curing can be obtained by irradiating the pressure-sensitive adhesive layer formed with an active energy ray.

As the adhesive layer, an aqueous adhesive or an active energy ray-curable adhesive can be used. Examples of the aqueous adhesive include an adhesive composed of a polyvinyl alcohol resin aqueous solution, and an aqueous two-pack polyurethane emulsion adhesive.

The active energy ray-curable adhesive is an adhesive that is cured by irradiation with an active energy ray such as ultraviolet ray, and examples thereof include an adhesive containing a polymerizable compound and a photopolymerization initiator, an adhesive containing a photoreactive resin, and an adhesive containing a binder resin and a photoreactive crosslinking agent. Examples of the polymerizable compound include photopolymerizable monomers such as a photocurable epoxy monomer, a photocurable (meth) acrylic monomer, and a photocurable urethane monomer, and oligomers derived from a photopolymerizable monomer. Examples of the photopolymerization initiator include photopolymerization initiators containing active substances that generate neutral radicals, anionic radicals, and cationic radicals by irradiation with active energy rays such as ultraviolet rays. As the active energy ray-curable adhesive containing a polymerizable compound and a photopolymerization initiator, an active energy ray-curable adhesive containing a photocurable epoxy monomer and a photocationic polymerization initiator can be preferably used.

From the viewpoint of reducing the height difference, the thickness of each adhesive layer is, for example, 3 to 100 μm, more preferably 5 to50 μm, and may be 20 μm or more.

[ touch sensor layer ]

The touch sensor layer 103 is not limited as long as it can detect a position touched on a front panel described later. Examples of the detection system include a resistive film system, a capacitive system, an optical sensor system, an ultrasonic system, an electromagnetic induction coupling system, and a surface acoustic wave system. From the viewpoint of low cost, a resistive-film type or capacitive-coupling type touch sensor panel is preferably used.

An example of a resistive touch sensor panel includes a pair of substrates arranged to face each other, an insulating spacer sandwiched between the pair of substrates, a transparent conductive film provided on the inner front surface of each substrate as a resistive film, and a touch position detection circuit. In an image display device provided with a resistive touch sensor panel, for example, if a surface of a front panel described later is touched, the opposing resistive films are short-circuited, and a current flows through the resistive films. The touch position detection circuit can detect the voltage change at this time and detect the touched position.

An example of a capacitive coupling type touch sensor panel includes a base material layer, a position detection transparent electrode layer provided on the entire surface of the base material layer, and a touch position detection circuit. In an image display device provided with a capacitive coupling type touch sensor panel, for example, if the surface of a front panel described later is touched, the transparent electrode can be grounded via the capacitance of a human body at the point of touch. The touch position detection circuit can detect grounding of the transparent electrode and detect the touch position.

The touch sensor layer 103 may have, for example, the following configuration: a configuration in which the resistive-type or capacitive-coupling-type touch sensor panel is formed on a glass plate with a separation layer interposed therebetween, the glass plate is separated from the separation layer, and a base material layer is provided on the separation layer; or a constitution in which the glass plate is separated from the separation layer so that the separation layer is exposed on the outermost surface. The touch sensor panel may further include an insulating layer, a protective layer, and an adhesive layer in addition to the transparent electrode layer and the base material layer.

By providing the colored layer 105 on the touch sensor layer 103, even if the colored layer 105 is narrow, the following tendency is exhibited: that is, the shielding property of the wiring 104 by the colored layer 105 is easily improved, and the adhesion between the touch sensor layer 103 and the polarizer layer 101 or a front panel described later is easily improved.

In recent years, as the display area is expanded, the non-display area is also narrowed, and the colored layer 105 formed in the non-display area tends to be narrowed, for example, to have a fine shape such as a thin line. On the other hand, the colored layer 105 is often formed on the polarizer layer 101 or on the front panel. In such a situation, if the polarizer layer 101 or the front panel is attached to the touch sensor layer 103 so that the narrowed colored layer 105 shields the wiring 104, a lot of time is consumed, and the attachment accuracy (accuracy of position matching) is not sufficient. In the case where the shielding property cannot be sufficiently obtained, the wiring 104 is recognized in the display area, which is not desirable. However, since the colored layer 105 is formed on the touch sensor layer 103 having the wiring as in the laminate 100 of the present invention, even when the colored layer 105 is narrowed, it is not necessary to align the colored layer 105 with the wiring 104, and therefore, the polarizer layer 101 or the front panel is extremely easily attached to the touch sensor layer 103, and the wiring 104 tends to have an excellent shielding effect by the colored layer 105.

(colored layer)

The colored layer 105 may be disposed on the side closer to the polarizing layer 101 than the wiring 104, and may be formed on the outermost surface of the touch sensor layer 103 on the side of the laminating layer 102, or may be disposed between a transparent electrode layer and a base material layer when the touch sensor layer 103 has the base material layer. The colored layer 105 may be formed of a single layer or a plurality of layers.

The colored layer 105 can be formed by a printing method using a composition for forming a colored layer such as ink or paint, or can be formed by a photolithography method when the composition for forming a colored layer is an active energy ray-curable type. Further, these methods may be combined.

Specific examples of the printing method include gravure printing, offset printing, screen printing, and transfer printing using a transfer sheet. Printing using the printing method may be repeated until a colored layer 105 of a desired thickness is obtained.

The composition for forming a colored layer used for forming the colored layer 105 contains, for example, a binder resin, a colorant, a solvent, and an optional additive. When the composition for forming a colored layer is an active energy ray-curable composition, the composition for forming a colored layer further contains an active energy ray-polymerizable compound. Further, a photopolymerization initiator, a photosensitizer, and the like may be contained as necessary.

Examples of the binder resin include chlorinated polyolefins (e.g., chlorinated polyethylene and chlorinated polypropylene), polyester resins, polyurethane resins, acrylic resins, vinyl acetate resins, vinyl chloride-vinyl acetate copolymers, and cellulose resins. The binder resin may be used alone, or 2 or more kinds may be used in combination. The binder resin may be a thermally polymerizable resin or a photopolymerizable resin.

The colorant may be black from the viewpoint of reducing the difference in visibility between the display region and the non-display region. When the colored layer 105 is formed of a plurality of layers, the colored layer 105 may be black or a color other than black as long as the colored layer disposed closest to the polarizing layer 102 is black.

The composition for forming a colored layer preferably contains carbon black from the viewpoint of reducing the difference in visibility. Examples of the colorant other than carbon black include inorganic pigments such as titanium white, spangle, carbon black, iron oxide red, chrome vermilion, ultramarine, cobalt blue, chrome yellow, and titanium yellow; organic pigments or dyes such as phthalocyanine blue, indanthrene blue, isoindolinone yellow, benzidine yellow, quinacridone red, polyazo red, perylene red, aniline black, and the like; metallic pigments made of scaly foils of aluminum, brass, and the like; a pearl lustre pigment (pearl pigment) is formed by a scaly foil such as titanium dioxide coated mica and alkaline lead carbonate. The colorant is preferably contained in an amount of 50 to 200 parts by mass per 100 parts by mass of the binder resin.

The thickness of the colored layer 105 is preferably 0.5 to50 μm, more preferably 1 to 30 μm, and may be 1.5 to 20 μm, from the viewpoint of suppressing the level difference and improving the shading effect.

In the case where the colored layer 105 is black, even if the thickness is thin, a high shading effect can be obtained as compared with other colors. In fig. 1, the colored layer 105 is illustrated as having a uniform thickness and a rectangular cross-sectional shape, but the colored layer 105 may have a non-uniform thickness and may have a cross-sectional shape having a tapered portion with a thickness decreasing toward the inside. By having the tapered portion, inflow of air which is likely to occur at the time of lamination can be suppressed. When the thickness of the colored layer 105 is not uniform, the numerical range described above as the thickness of the colored layer 105 is the maximum thickness of the colored layer 105.

The colored layer 105 is not limited to the form provided on the entire periphery of the peripheral portion of the touch sensor layer 103, and may be provided only on a part of the peripheral portion depending on desired design or the like. When the colored layer 105 is provided on the peripheral portion of the touch sensor layer 103, the width thereof may be appropriately determined depending on the size of the display region, desired design, and the like, and may be, for example, in the range of 10 μm to50 mm or in the range of 10 μm to5 mm.

(Wiring)

In order to electrically connect the touch position detection circuit and the transparent electrode in the touch sensor panel, a wiring 104 may be disposed. The wiring 104 may be a wiring in which a metal film is patterned. The metal film may be formed as follows: a metal film is formed by sputtering or vapor deposition of a metal such as aluminum, copper, silver, gold, or an alloy thereof, and then the metal film is patterned by photolithography or etching. The wiring 104 may be provided over a transparent conductive film or a transparent electrode layer in the non-display region. The thickness of the wiring 104 may be, for example, 30nm to 7 μm. The line width of the wiring 104 is usually 1 μm to 2 mm.

(substrate layer)

Examples of the base layer include a base film having a transparent conductive layer vapor-deposited on one surface thereof, a base film having a transparent conductive layer transferred thereto via an adhesive layer, and the like. Alternatively, the separation layer described later may be used as the base layer without another base film.

The base film is not particularly limited as long as it is a resin film that transmits light.

Examples thereof include cyclic polyolefin resin films; cellulose acetate resin films made of resins such as triacetyl cellulose and diacetyl cellulose; polyester resin films formed of resins such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate; a polycarbonate-based resin film; a (meth) acrylic resin film; a polypropylene resin film and the like known in the art. Among them, cyclic polyolefin resin films are preferable. The thickness of the base film is usually 300 μm or less, preferably 200 μm or less, more preferably 100 μm or less, and usually 5 μm or more, preferably 10 μm or more. After assembling the transparent conductive layer to the touch sensor layer, the substrate layer may be removed from the touch sensor layer.

(transparent conductive layer)

The transparent conductive layer may be a transparent conductive layer made of a metal oxide such as ITO, or may be a metal layer made of a metal such as aluminum, copper, silver, gold, or an alloy thereof. The transparent conductive layer may be patterned by photolithography. The touch sensor layer 103 may have 1 or 2 or more transparent conductive layers. The transparent conductive layer may be a single layer or a plurality of layers, and in the case of a plurality of layers, materials forming each layer may be the same type or different types.

(separation layer)

The separation layer is a layer formed over a substrate such as a glass plate to separate a transparent conductive layer formed over the separation layer from the substrate together with the separation layer. The separation layer is preferably an inorganic layer or an organic layer. Examples of the material for forming the inorganic layer include silicon oxide. Examples of the material for forming the organic layer include a (meth) acrylic resin composition, an epoxy resin composition, and a polyimide resin composition. The separation layer may be removed with the substrate such that the touch sensor layer is free of the separation layer.

(insulating layer)

The insulating layer may be formed so as to cover the wiring 104 and the transparent conductive layer. The insulating layer may be formed of at least 1 material selected from the group consisting of a curable prepolymer, a curable polymer, and a plastic polymer. The insulating layer may be formed of a varnish-type material capable of forming a film. The varnish-type material may contain at least 1 selected from the group consisting of a polyorganosiloxane, a polyimide, and a polyurethane material. The insulating layer may be an adhesive layer described later. The insulating layer may be patterned by photolithography. The insulating layer may be a single layer or a plurality of layers, and in the case of a plurality of layers, materials forming each layer may be the same kind or different kinds.

(adhesive layer)

Examples of the adhesive layer include the adhesive layer used for the adhesive layer and the adhesive layer. The adhesive layer may contain at least 1 material selected from the group consisting of polyester-based resins, polyether-based resins, polyurethane-based resins, epoxy-based resins, silicone-based resins, and acrylic-based resins.

[ other layers ]

The laminate 100 may have a front panel and an organic EL display element as other layers.

(front panel)

The front panel is preferably a plate-like body that transmits light. The front panel may be composed of only 1 layer, or may be composed of 2 or more layers. The front panel may constitute an outermost surface of the image display device.

Examples of the front panel include a glass plate (e.g., a glass plate, a glass film, etc.) and a resin plate (e.g., a resin plate, a resin sheet, a resin film, etc.). Among the above, from the viewpoint of flexibility of the laminate and the image display device including the same, a plate-like body made of a resin such as a resin film is preferable.

Examples of the thermoplastic resin constituting the resin plate-like body such as a resin film include polyolefin resins such as a chain polyolefin resin (e.g., a polyethylene resin, a polypropylene resin, and a polymethylpentene resin) and a cyclic polyolefin resin (e.g., a norbornene resin); cellulose resins such as triacetyl cellulose; polyester resins such as polyethylene terephthalate, polyethylene naphthalate and polybutylene terephthalate; a polycarbonate-based resin; ethylene-vinyl acetate-based resin; a polystyrene-based resin; a polyamide resin; a polyetherimide resin; (meth) acrylic resins such as polymethyl (meth) acrylate resins; a polyimide-based resin; a polyether sulfone-based resin; a polysulfone-based resin; a polyvinyl chloride resin; a polyvinylidene chloride resin; a polyvinyl alcohol resin; a polyvinyl acetal resin; a polyether ketone resin; a polyether ether ketone resin; a polyether sulfone-based resin; polyamide-imide resins, and the like.

The thermoplastic resin may be used alone or in combination of 2 or more.

Among them, polyimide-based resins, polyamide-based resins, and polyamideimide-based resins are preferably used as the thermoplastic resin constituting the front panel from the viewpoint of flexibility, strength, and transparency.

The front panel may be a film having a hard coat layer provided on at least one side of the base film to further increase the hardness. As the base film, the above resin film can be used.

The hard coat layer may be formed on one surface of the substrate film or on both surfaces. By providing the hard coat layer, hardness and scratch resistance can be improved. The thickness of the hard coat layer may be, for example, 0.1 to 30 μm, preferably 1 to 20 μm, and more preferably 5 to 15 μm.

The hard coat layer is a cured layer of, for example, an ultraviolet curable resin. Examples of the ultraviolet curable resin include (meth) acrylic resins, silicone resins, polyester resins, polyurethane resins, amide resins, and epoxy resins. The hard coating may also contain additives for strength enhancement. The additive is not limited, and examples thereof include inorganic fine particles, organic fine particles, and a mixture thereof.

The front panel may have not only a function of protecting the front (screen) of the image display device (function as a window film), but also a function as a touch sensor, a blue light prevention function, a viewing angle adjustment function, and the like.

The thickness of the front plate may be, for example, 10 to 2000. mu.m, or 20 to 2000. mu.m, preferably 25 to 1500. mu.m, more preferably 30 to 1000. mu.m, still more preferably 40 to 500. mu.m, particularly preferably 40 to 200. mu.m, or further 40 to 100. mu.m.

(organic EL display element)

As the organic EL display element, a conventionally known organic EL display element can be used.

[ method for producing laminate ]

The laminate according to one embodiment of the present invention can be produced by bonding layers constituting the laminate to each other via a bonding layer. When the layers are bonded to each other via the bonding layer, it is preferable to apply a surface activation treatment such as corona treatment to one or both of the bonding surfaces in order to improve the adhesion.

The method for manufacturing the laminate 100 may include, for example, a step of preparing the polarizing layer 101, a step of preparing the touch sensor layer 103, and a step of bonding the polarizing layer and the touch sensor layer via a bonding layer; the step of preparing the touch sensor layer 103 may include a colored layer forming step of forming the colored layer 105 by photolithography.

The polarizing layer 101 may be formed directly on the front panel or the substrate, or may be formed with an alignment film interposed therebetween, and the substrate may be incorporated into the laminate, or may be separated from the polarizing layer 101 without being a component of the laminate.

The touch sensor layer 103 can be manufactured by, for example, the following methods 1 to 4.

In the method 1, first, the base material layer 111 is laminated on the glass plate via an adhesive layer. On the base material layer 111, a transparent conductive layer, a wiring 104, and a colored layer 105 are formed in this order. The glass substrate is separated from the base material layer 111 by heating, whereby the touch sensor layer 103 including the colored layer 105, the wiring 104, the transparent conductive layer, and the base material layer 111 can be obtained.

In the method 2, a separation layer is first formed on a glass plate. On the separation layer, a transparent conductive layer, a wiring 104, an insulating layer, and a coloring layer 105 are formed in this order. A peelable thermoplastic resin film is laminated on the outermost surface on the side opposite to the separation layer, and the colored layer 105 is transferred onto the peelable thermoplastic resin film through the separation layer to separate the glass plate. Next, the base layer 111 is prepared, and the base layer 111 and the release layer are bonded via an adhesive layer. The touch sensor layer 103 can be obtained by peeling off the peelable thermoplastic resin film, and the touch sensor layer 103 includes a colored layer 105, an insulating layer, a wiring 104, a transparent conductive layer, a separation layer, an adhesive layer, and a base material layer 111 in this order. Before the colored layer 105 is formed, another transparent conductive layer may be formed on the insulating layer, and another insulating layer may be formed on the other transparent conductive layer.

In the method 3, a separation layer is first formed on a glass plate. On the separation layer, a transparent conductive layer, a wiring 104, an insulating layer, and a coloring layer 105 are formed in this order. The polarizing layer 101 is bonded to the outermost surface opposite to the separation layer via the bonding layer 102. Next, the glass plate is separated, whereby a touch sensor layer 103 can be obtained, and the touch sensor layer 103 includes a colored layer 105, an insulating layer, a wiring 104, a transparent conductive layer, and a separation layer in this order. Another transparent conductive layer may be further formed over the insulating layer, another insulating layer may be formed over the other transparent conductive layer, and the colored layer 105 may be formed over the other insulating layer.

In the 4 th method, a separation layer is first formed on a glass plate. A colored layer 105 is formed on the separation layer. Next, a transparent conductive layer, a wiring 104, and an insulating layer are sequentially formed on the colored layer 105. A peelable thermoplastic resin film is laminated on the outermost surface on the side opposite to the separation layer, and the glass plate is separated by transferring the separation layer to the insulating layer onto the peelable thermoplastic resin film. Next, a base layer is prepared, and the base layer and the separation layer are bonded via an adhesive layer. The touch sensor layer 103 can be obtained by peeling off the peelable thermoplastic resin film, and the touch sensor layer 103 includes an insulating layer, a wiring 104, a transparent conductive layer, a colored layer 105, a separation layer, an adhesive layer, and a base material layer in this order. Before the peelable thermoplastic resin film is laminated, another transparent conductive layer may be formed on the insulating layer, and another insulating layer may be formed on the other transparent conductive layer.

The colored layer 105 is preferably formed by photolithography. When the colored layer 105 is formed by photolithography, the thickness of the colored layer 105 is easily reduced, and the difference in height between the display region and the non-display region tends to be reduced on the surface of the laminate 100 on the touch sensor 103 side.

The photolithography method is a method in which the active energy ray-curable composition for forming a colored layer is applied onto an insulating layer or a base material layer, dried to form a composition layer for forming a colored layer, and the composition layer for forming a colored layer is exposed to light through a photomask and developed. After development, post baking may also be performed.

When the adhesive layer is bonded to the polarizing layer 101 and the touch sensor layer 103, a treatment such as corona treatment or plasma treatment may be applied to the bonding surface.

[ use of image display device ]

The image display device of the present invention can be used as mobile devices such as smart phones and tablet computers, televisions, digital photo frames, electronic signboards, measuring instruments, office equipment, medical equipment, computer equipment, and the like. The laminate of the present invention has a wide display area and is reduced in apparent unevenness, and therefore, a high-quality image display device having an enlarged display area can be provided.

Examples

The present invention will be described in further detail with reference to examples, but the present invention is not limited to these examples. In the examples, "%" and "part(s)" are% by mass and part(s) by mass unless otherwise specified.

[ color difference ]

The color tones a of the non-display region and the display region were measured from the front panel side of the laminate using an integrating sphere reflectance measuring instrument (KONICAMINOLTA, CM-3700d)^*And b^*Determining the absolute value Deltaa of the difference between the color tones of the non-display region and the display region^*And Δ b^*。

[ difference in height ]

The difference in height between the display region and the non-display region was measured on the surface of the laminate on the touch sensor side using an interference microscope (Bruker GT).

[ positional accuracy ]

A distance La131 between the center of the touch sensor alignment mark (cross "+") (hereinafter also referred to as a TS mark) 104a and the center of the colored layer alignment mark (cross "+") (hereinafter also referred to as a colored mark) 105a shown in fig. 4 was measured using an optical microscope (olympus). Distance La131 can be obtained from the absolute values Δ x and Δ y of the differences between TS symbol 104a and colored symbol 105a in the x direction and the y direction, according to the following equation.

La＝[(Δx)²+(Δy)²]^1/2

The distance La131 is equal to the distance L132 between the colored layer 105 and the wiring 104, and the smaller the distance La131 is, the better the positional accuracy between the colored layer 105 and the wiring 104 tends to be. The distance La131 is indicated by "O" when it is 5 μm or less, by "Δ" when it is larger than 5 μm and 50 μm or less, and by "X" when it is larger than 50 μm.

[ optical Density ]

The same operations as in the examples and comparative examples were carried out on a transparent glass substrate to prepare sample films of the colored layers, and the Optical Density (OD) of each of the obtained sample films was measured using an optical density measuring instrument (product name: 361T, X-rite Co.).

< composition for forming colored layer 1 >

Composition for forming active energy ray-curable colored layer containing carbon black (CR-BK 0951L, manufactured by Samsung SDI Co., Ltd.)

< composition for forming colored layer 2 >

[ ink Components ]

Acetylene black (carbon black) 15% by mass

75% by mass of polyester

Dimethyl glutarate 2.5% by mass

Succinic acid 2% by mass

5.5% by mass of isophorone

[ curing agent ]

75% by mass of aliphatic polyisocyanate

25% by mass of ethyl acetate

[ solvent ]

Isophorone

[ production method ]

With respect to 100 parts by mass of the ink component, 10 parts by mass of a curing agent and 10 parts by mass of a solvent were added and stirred to obtain a composition 2 for forming a colored layer.

< production of adhesive sheet 1 >

84 parts by mass of 2-ethylhexyl acrylate, 15 parts by mass of isobornyl acrylate, 1 part by mass of hydroxypropyl acrylate, and 0.02 part by mass of 1-hydroxycyclohexyl phenyl ketone as a polymerization initiator are mixed. The mixed solution is irradiated with ultraviolet rays to polymerize the monomer.

Then, 0.4 part of 1-hydroxycyclohexyl phenyl ketone, 0.3 part of lauryl acrylate, 0.05 part of polyethylene glycol (200) diacrylate and 0.05 part of (3-glycidyloxypropyl) trimethoxysilane were added to the above-mentioned mixture as a polymerization initiator to prepare a pressure-sensitive adhesive composition.

The adhesive composition was applied to a polyethylene terephthalate film (release film) whose surface was treated with silicon. The coating thickness was 25 μm. Another release film was prepared and laminated on the coating film. The laminate comprising the release film/pressure-sensitive adhesive composition coating film/release film layer was irradiated with ultraviolet light. In the ultraviolet irradiation step, the ultraviolet rays of 300 to 400nm (the intensity of light emitted at 365nm is maximized) are irradiated so that the cumulative light amount is 1500mJ/cm²The laminated body is irradiated. In this manner, an adhesive sheet 1 having a (meth) acrylic adhesive layer 1 with a thickness of 25 μm was produced.

< production of adhesive sheet 2 >

A mixed solution of 81.8 parts of acetone, 61.0 parts of butyl acrylate, 37 parts of methyl methacrylate, 1.0 part of acrylic acid and 1.0 part of 2-hydroxyethyl acrylate was charged into a reactor equipped with a cooling tube, a nitrogen introduction tube, a thermometer and a stirrer, and the atmosphere in the apparatus was replaced with nitrogen gas so as to be free of oxygen and the internal temperature was raised to 55 ℃. Thereafter, a solution prepared by dissolving 0.14 parts of azobisisobutyronitrile (polymerization initiator) in 10 parts of acetone was added to the reaction mixture. After 1 hour of the initiator addition, acetone was continuously added to the reactor at an addition rate of 17.3 parts/hr so that the concentration of the acrylic resin other than the monomer was 35%, the temperature was maintained at 54-56 ℃ for 12 hours, and finally ethyl acetate was added to adjust the concentration of the acrylic resin to 20%.

I) the above nonvolatile content amount of acrylic resin: 100 parts, ii) Coronate L as an isocyanate-based compound: 3.0 parts, iii) KBM403 as a silane-based compound: 0.5 part of the mixture is mixed. Ethyl acetate was added so that the total solid content concentration became 10%, to obtain a pressure-sensitive adhesive composition.

The obtained pressure-sensitive adhesive composition was applied to the release-treated surface of the polyethylene terephthalate film (thickness: 38 μm) after the release treatment by an applicator so that the thickness after drying was 5 μm. The coating layer was dried at 100 ℃ for 1 minute to obtain a film having the adhesive layer 2. Thereafter, another polyethylene terephthalate film (38 μm in thickness) after the mold release treatment was attached to the pressure-sensitive adhesive layer 2. Then, the resultant was aged at 23 ℃ and 50% RH relative humidity for 7 days to prepare an adhesive sheet 2.

< example 1 >

1. Fabrication of touch sensor layers

The following describes steps for fabricating the touch sensor layer with reference to fig. 5.

1) Formation of a separation layer (FIG. 5a)

An acrylic resin was applied to the glass plate 301 to form a separation layer 302.

2) Formation of touch sensor layers (FIG. 5b)

On the separation layer 302, a1 st ITO layer 303, a wiring (copper pattern) 304, a1 st insulating layer 305, a 2 nd ITO layer 306, and a 2 nd insulating layer 307 are formed in this order.

The 1 st ITO layer 303, the 2 nd ITO layer 306, and the wiring 304 are each fabricated as follows. An ITO film or a metal film is formed by a sputtering method. Next, a photoresist film pattern is formed on the ITO film or the metal film by photolithography (including the following steps: a photoresist coating step, an exposure step, and a developing step). After patterning the ITO film or the metal film by an etching method, the photoresist film pattern is removed. When the wiring 304 is formed, a TS mark for confirming the positional accuracy and the stacking state is formed in the outer region of the touch sensor unit.

The 1 st insulating layer 305 and the 2 nd insulating layer 307 are patterned by photolithography (including the following steps: a composition coating step for forming an insulating layer, an exposure step, a development step, and a thermosetting step).

3) Formation of colored layer (FIG. 5c)

On the 2 nd insulating layer 307, a colored layer 308 is formed to have a thickness of 1.5 μm after drying using the composition 1 for forming a colored layer. The colored layer 308 is formed by photolithography (including the following steps: a coating step of the composition 1 for forming a colored layer, an exposure step, a development step, and a thermosetting step). The colored layer 308 is formed on the 2 nd insulating layer 307 so that the wiring 304 is located below the colored layer 308. The coloring layer 308 is formed so that the coloring mark and the TS mark are formed at the same position.

4) Transfer of touch sensor layer (FIG. 5d)

An adhesive-coated PET film 309 (having a thickness of 52 μm) was bonded to the surface of the colored layer 308.

The touch sensor laminate 300 is peeled from the glass plate 301 together with the PET film 309.

On the surface on the separation layer 302 side, a base material layer 311(COP film, thickness 23 μm) was bonded via an adhesive layer (photocurable adhesive) 310.

2. Fabrication of polarizing layers

A polyvinyl alcohol film having an average polymerization degree of about 2400 and a saponification degree of 99.9 mol% and a thickness of 30 μm (Kuraray co., trade name "Kuraray vinyl VF-PE # 3000" manufactured by ltd.) was immersed in pure water at 37 ℃ and then immersed in an aqueous solution containing iodine and potassium iodide at 30 ℃ (iodine/potassium iodide/water (mass ratio): 0.05/1.7/100).

The resulting solution was immersed in an aqueous solution of potassium iodide and boric acid at 58 ℃ (potassium iodide/boric acid/water (weight ratio) ═ 12/3.2/100). After the film was washed with pure water at 15 ℃ and dried at 80 ℃, a polarizer having a thickness of about 12 μm in which iodine was adsorbed and oriented to polyvinyl alcohol was obtained. The stretching was mainly performed in the steps of iodine dyeing and boric acid treatment, and the total stretching magnification was 5.5 times. A triacetyl cellulose (TAC) film having a thickness of 25 μm was bonded to one surface of the obtained polarizer via an adhesive layer.

A retardation layer including a layer obtained by polymerizing and curing a liquid crystal compound [ thickness 16 μm, layer composition: adhesive layer (thickness 5 μm)/λ/4 plate composed of liquid crystal compound cured layer and alignment film (thickness 3 μm)/adhesive layer (thickness 5 μm)/adhesive layer on λ/4 plate side of positive C plate composed of liquid crystal compound cured layer and alignment film (thickness 3 μm) ]. The polarizing layer thus prepared was prepared (layer composition of "TAC/polarizer/phase difference layer", thickness 53 μm). The polarizing layer is a circular polarizing film.

3. Production of front Panel with adhesive layer

A front panel (thickness: 50 μm) was prepared in which a hard coat layer (thickness: 10 μm) was formed on one surface of a polyimide resin film (thickness: 40 μm) using a composition containing a dendrimer compound having a polyfunctional acrylic group at the terminal.

As the 1 st adhesive layer, the adhesive layer 1 of the adhesive sheet 1 prepared above was prepared. And applying corona treatment to the bonding surface of the front panel and the 1 st bonding layer and the bonding surface of the 1 st bonding layer and the front panel. And (3) laminating the front panel and the 1 st laminating layer to obtain the front panel with the adhesive layer.

4. Production of laminate

The steps for producing the laminate will be described below with reference to fig. 5.

After corona treatment was applied to the bonding surface of the front panel 312 on the side of the 1 st bonding layer 313 and the bonding surface of the polarizing layer 314 on the TAC side, the front panel 312 with the adhesive layer and the polarizing layer 314 were laminated so that these surfaces were located inside, and bonded using a roll bonder (fig. 5 e).

As the 2 nd laminating layer 315, the pressure-sensitive adhesive layer 1 of the pressure-sensitive adhesive sheet 1 prepared above was prepared. The surface of the polarizing layer 314 on the retardation layer side and the surface of the 2 nd adhesive layer 315 which is attached to the polarizing layer 314 are subjected to corona treatment. The 2 nd lamination layer 315 is laminated on the surface of the polarizing layer 314 on the retardation layer side (fig. 5 f).

The pressure-sensitive adhesive-attached PET film 309 was peeled off, and the surface on the colored layer 308 side was bonded to the 2 nd bonding layer 315 of the polarizing layer 314, thereby obtaining a laminate 320 of example 1 (fig. 5 g). The results are shown in Table 1.

< example 2 >

A laminate of example 2 was obtained in the same manner as in example 1 except that a polarizing layer was prepared as described below. The results are shown in Table 1.

The composition for an alignment film was coated on one side of a 25 μm TAC film, and dried and subjected to polarized light exposure to form an alignment film. A composition containing a dichroic dye and a polymerizable liquid crystal compound is applied to the alignment film and dried. The polymerizable liquid crystal compound was cured by ultraviolet irradiation to form a coated polarizer (thickness: 2 μm). Next, a protective composition comprising polyvinyl alcohol and water was applied to the side of the polarizer opposite to the TAC film, and dried to form a protective layer (thickness 0.5 μm, omitted in the figure). A retardation layer including a layer obtained by polymerizing and curing a liquid crystal compound [ thickness 16 μm, layer structure: adhesive layer (thickness 5 μm)/λ/4 plate composed of liquid crystal compound cured layer and alignment film (thickness 3 μm)/adhesive layer (thickness 5 μm)/positive C plate composed of liquid crystal compound cured layer and alignment film (thickness 3 μm) ]. The polarizing layer thus prepared was prepared (layer composition of "TAC/polarizer/phase difference layer", thickness 43 μm).

< example 3 >

1. Fabrication of touch sensor layers

The following describes steps for fabricating the touch sensor layer with reference to fig. 6.

1) Formation of a separation layer (FIG. 6a)

An acrylic resin was applied to a glass plate 401 to form a separation layer 402.

2) Formation of touch sensor layers (FIG. 6b)

On the separation layer 402, a1 st ITO layer 403, a wiring (copper pattern) 404, a1 st insulating layer 405, a 2 nd ITO layer 406, and a 2 nd insulating layer 407 are formed in this order.

The 1 st ITO layer 403, the 2 nd ITO layer 406, and the wiring 404 are each fabricated as follows. An ITO film or a metal film is formed by a sputtering method. Next, a photoresist film pattern is formed on the ITO film or the metal film by photolithography (a photoresist coating step, an exposure step, and a development step). After patterning the ITO film or the metal film by an etching method, the photoresist film pattern is removed. When the wiring 404 is formed, a TS mark for confirming the positional accuracy and the stacking state is formed in the outer region of the touch sensor unit.

The 1 st insulating layer 405 and the 2 nd insulating layer 407 are patterned by photolithography (including the following steps: a composition coating step for forming an insulating layer, an exposure step, a development step, and a thermosetting step).

3) Formation of colored layer (FIG. 6c)

On the 2 nd insulating layer 407, a colored layer 408 was formed using the above colored layer forming composition 1 so that the thickness after drying was 1.5 μm. The colored layer 408 is formed by photolithography (including the following steps: a colored layer forming composition 1 coating step, an exposure step, a development step, and a thermosetting step). The colored layer 408 is formed on the insulating layer 2 407 such that the wiring 404 is located below the colored layer 408. The coloring layer 408 is formed so that the coloring mark and the TS mark are formed at the same position.

2. Fabrication of polarizing layers

A polarizing layer was produced in the same manner as in "2. production of polarizing layer" in example 1.

3. Production of front Panel with adhesive layer

A front panel with an adhesive layer was produced in the same manner as in "3. production of front panel with an adhesive layer" in example 1.

4. Production of laminate

The following describes a manufacturing process of the multilayer body with reference to fig. 6.

The laminating surface on the 1 st laminating layer 413 side of the front panel 412 and the laminating surface on the TAC side of the polarizing layer 414 were subjected to corona treatment, and then the front panel 412 with an adhesive layer and the polarizing layer 414 were laminated with these surfaces being inside, and laminated using a roll bonder (fig. 6 d).

As the 2 nd lamination layer 415, the pressure-sensitive adhesive layer 2 of the pressure-sensitive adhesive sheet 2 prepared above was prepared. The surface of the polarizing layer 414 on the retardation layer side and the surface of the 2 nd adhesive layer 415 adhering to the polarizing layer 414 are subjected to corona treatment. The 2 nd lamination layer 415 is laminated on the surface of the polarizing layer 414 on the retardation layer side (fig. 6 e).

The surface on the colored layer 408 side was bonded to the 2 nd bonding layer 415 of the polarizing layer 414, and the glass plate 401 was peeled off from the separation layer 402, thereby obtaining a laminate 420 of example 3 (fig. 6 f). The results are shown in Table 1.

< example 4 >

1. Fabrication of touch sensor layers

The following describes steps for fabricating the touch sensor layer with reference to fig. 7.

1) Formation of a separation layer (FIG. 7a)

An acrylic resin was applied to a glass plate 501 to form a separation layer 502.

2) Formation of colored layer (FIG. 7b)

On the separation layer 502, a colored layer 508 was formed using the above composition 1 for forming a colored layer so that the thickness after drying was 1.5 μm. The colored layer 508 is formed by photolithography (including the following steps: a coating step of the composition 1 for forming a colored layer, an exposure step, a development step, and a thermosetting step).

When the colored layer 508 is formed, a colored mark is formed in an outer region of the touch sensor unit.

3) Formation of touch sensor layers (FIG. 7c)

On the colored layer 508 of the separation layer 502, a1 st ITO503 layer, a wiring (copper pattern) 504, a1 st insulating layer 505, a 2 nd ITO layer 506, and a 2 nd insulating layer 507 are formed in this order.

The 1 st ITO layer 503, the 2 nd ITO layer 506, and the wiring 504 are each fabricated as follows. An ITO film or a metal film is formed by a sputtering method. Next, a photoresist film pattern is formed on the ITO film or the metal film by photolithography (a photoresist coating step, an exposure step, and a development step). After patterning the ITO film or the metal film by an etching method, the photoresist film pattern is removed. The wiring 504 is formed so that the TS mark and the colored mark are formed at the same position.

4) Transfer of touch sensor layer (FIG. 7d)

An adhesive-attached PET film 509 (thickness 52 μm) was bonded to the surface of the 2 nd insulating layer 507 side. After the touch sensor laminate 500 was peeled from the glass plate 501 together with the PET film 509, a base material layer 511(COP film, thickness 23 μm) was bonded to the surface on the separation layer 502 side through an adhesive layer (photocurable adhesive) 510.

2. Fabrication of polarizing layers

3. Production of front Panel with adhesive layer

4. Production of laminate

The steps for producing the laminate will be described below with reference to fig. 7.

The laminating surface of the 1 st laminating layer 513 side of the front panel 512 and the laminating surface of the polarizing layer 514 on the TAC side were subjected to corona treatment, and then the front panel 512 with an adhesive layer and the polarizing layer 514 were laminated with these surfaces being inside and laminated by a roll bonder (fig. 7 e).

As the 2 nd laminating layer 515, the pressure-sensitive adhesive layer 1 of the pressure-sensitive adhesive sheet 1 prepared above was prepared. The surface of the polarizing layer 514 on the retardation layer side and the surface of the 2 nd adhesive layer 515 which is adhered to the polarizing layer 514 are subjected to corona treatment. The 2 nd adhesive layer 515 is bonded to the surface of the polarizing layer 514 on the retardation layer side (fig. 7 f).

The surface on the base material layer 511 side was bonded to the 2 nd bonding layer 515 of the polarizing layer 514, to obtain a laminate 520 of example 4 (fig. 7 g). The results are shown in Table 1.

< example 5 >

A laminate of example 5 was obtained in the same manner as in example 3, except that the colored layer was produced as described below in the production of the touch sensor layer of example 3. The results are shown in Table 1.

The colored layer is formed on the 2 nd insulating layer of the touch sensor layer. The ink used was the composition 2 for forming a colored layer prepared above. Printing was repeated 2 times by the screen printing method to obtain a coating thickness of 3 μm. The screen used is a 460 mesh screen.

< comparative example 1 >

A laminate of comparative example 1 was produced in the same manner as in example 1, except that a colored layer was provided on the surface of the front panel to which the 1 st adhesive layer was adhered, instead of forming a colored layer on the 2 nd insulating layer of the touch sensor layer. The results are shown in Table 1.

< comparative example 2 >

A laminate of comparative example 2 was produced in the same manner as in example 2, except that a colored layer was provided on the surface of the front panel to which the 1 st adhesive layer was adhered, instead of forming a colored layer on the 2 nd insulating layer of the touch sensor layer. The results are shown in Table 1.

< comparative example 3 >

A laminate of comparative example 3 was produced in the same manner as in example 1, except that a colored layer was provided on the retardation layer side surface of the polarizing layer instead of forming a colored layer on the insulating layer 2 of the touch sensor layer. The results are shown in Table 1.

[ Table 1]

Description of the symbols

100,200,320,420,520 laminate, 101,314,414,514 polarizing layer, 102,202,203 laminating layer, 103 touch sensor layer, 104,304,404,504 wiring, 104a TS mark, 105,308,408,508 coloring layer, 105a coloring mark, 121 display area a, 122 non-display area B, 131 distance La, 132 distance L, 201,312,412,512 front panel, 204 organic EL display element, 300,500 touch sensor laminate, 301,401,501 glass plate, 302,402,502 separating layer, 303,403,503 ITO 1, 305,405,505 ITO 1, 306,406,506 ITO 2, 307,407,507 ITO 2, 309,509 adhesive PET film, 310,510 adhesive layer, 311,511 base layer, 313,413,513 ITO 1, 315,415,515 laminating layer 2.

Claims

1. A laminate comprising a polarizing layer, an adhesive layer and a touch sensor layer in this order,

the touch sensor layer is provided with a wiring and a coloring layer,

the laminated body is divided into a display area and a non-display area in a plan view,

2. The laminate according to claim 1, wherein the observation is made from the polarizing layer sideAbsolute value Δ a of color difference between the display area and the non-display area^*And Δ b^*All are 0.3 or less.

3. The laminate according to claim 1 or 2, wherein the colored layer comprises carbon black.

4. The laminate according to any one of claims 1 to 3, wherein a height difference between the display region and the non-display region on the outermost surface when viewed from the touch sensor layer side is 3 μm or less.

5. The laminate according to any one of claims 1 to 4, wherein the colored layer has a thickness of 2 μm or less and an optical density of 4 or more.

6. The laminate according to any one of claims 1 to5, further comprising an organic EL display element on an outermost surface on the side of the touch sensor layer.

7. An image display device comprising the laminate according to any one of claims 1 to 6.

8. A method of manufacturing the laminate of any one of claims 1 to 6, comprising:

a step of preparing a polarizing layer by using a polarizing film,

a process of preparing a touch sensor layer,

bonding the polarizing layer and the touch sensor layer via a bonding layer;