Kit for image display panel, image display panel, and image display device

Abstract

This image display panel kit is provided with: an optical laminate including a polarizer containing iodine; and a conductive paste. When the optical laminate having a cured layer of the conductive paste formed on the side surface thereof is subjected to a humid heat test at a temperature of 85 DEG C, a relative humidity of 85%, and a test time of 240 hours, and the iodine-containing deposits in the optical laminate after the humid heat test are evaluated, the iodine-containing deposits in the optical laminate after the humid heat test are evaluated. The maximum precipitation distance of the precipitate from the side surface on which the cured layer is formed in a direction perpendicular to the side surface is 700 [mu] m or less. The kit is suitable for manufacturing an image display panel having excellent environmental resistance, in which a conductive structure is formed on a side surface of an optical laminate.

Description

Technical Field

[0001] The present invention relates to a kit for an image display panel, an image display panel, and an image display device. Background Art

[0002] Image display devices typified by liquid crystal display devices and electroluminescent (EL) display devices (e.g., organic EL display devices, inorganic EL display devices) are rapidly spreading. Each of the above-described various image display devices generally includes an image display panel, and the image display panel includes an image forming layer such as a liquid crystal layer and an EL light emitting layer, and an optical laminate including an optical film disposed on the image forming layer. A typical example of the optical film is a polarizing film.

[0003] In an image display device, static electricity sometimes becomes a problem. Static electricity is likely to be generated when manufacturing an image display device, for example, when an optical laminate is bonded to an image forming layer via an adhesive sheet, or when in use, for example, when a user touches the image display device. Generation of static electricity may cause poor display of the image display device. In addition, in recent years, image display devices having a touch panel, and image display devices having a touch sensor built in the image display panel are spreading. In these image display devices, static electricity may cause malfunction of the touch panel and the touch sensor. Patent Document 1 discloses a technique of adding an antistatic agent to an adhesive sheet in order to prevent charging due to static electricity.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2011-528448 Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] From the viewpoint of sufficiently suppressing charging, it is conceivable to form an image display panel having a conduction structure formed on a side surface of an optical laminate. The conduction structure can be formed, for example, by coating and curing a conductive paste. On the other hand, in vehicle-mounted applications as a typical example, the demand for the environmental resistance performance of an image display device is increasing. For example, there is an increasing demand for the performance capable of withstanding a damp heat test assumed to be used in a very harsh environment. The inventors of the present invention have found through research that, when the conditions of the damp heat test are set severely, in an image display panel having a conduction structure formed on a side surface of an optical laminate, a specific display image deterioration that is not observed in a panel not having the conduction structure occurs.

[0009] An object of the present invention is to provide a kit for an image display panel suitable for manufacturing an image display panel having excellent environmental resistance performance, the image display panel having a conduction structure formed on a side surface of an optical laminate.

[0010] Method for solving problems

[0011] The present invention provides a kit for an image display panel, which includes an optical laminate and a conductive paste. The optical laminate includes a polarizer containing iodine.

[0012] Among them, when a damp heat test at a temperature of 85 °C, a relative humidity of 85%, and a test time of 240 hours is performed on the optical laminate having a cured layer of the above-mentioned conductive paste formed on the side surface, and the iodine-containing precipitates in the optical laminate after the above-mentioned damp heat test are evaluated,

[0013] The maximum precipitation distance of the precipitates in the direction perpendicular to the side surface from the side surface where the cured layer is formed is 700 μm or less.

[0014] According to another aspect, the present invention provides an image display panel, which includes an image forming layer and an optical laminate disposed on the visible side of the above-mentioned image forming layer, and has a conduction structure on the side surface of the above-mentioned optical laminate.

[0015] The above-mentioned optical laminate includes a polarizer containing iodine.

[0016] The above-mentioned conduction structure includes a cured layer of a conductive paste.

[0017] When a damp heat test at a temperature of 85 °C, a relative humidity of 85%, and a test time of 240 hours is performed, and the iodine-containing precipitates in the optical laminate after the above-mentioned damp heat test are evaluated,

[0018] The maximum precipitation distance of the precipitates in the direction perpendicular to the side surface from the side surface where the above-mentioned conduction structure is formed is 700 μm or less.

[0019] According to another aspect, the present invention provides an image display device, which includes the above-mentioned image display panel of the present invention.

[0020] Effects of the invention

[0021] According to the present invention, it is possible to provide a kit for an image display panel suitable for manufacturing an image display panel with excellent environmental resistance, and the image display panel has a conduction structure formed on the side surface of the optical laminate. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a cross-sectional view schematically showing an example of an optical laminate that the kit for an image display panel of the present invention may include.

[0023] Figure 2It is a schematic diagram for explaining a method for evaluating the maximum precipitation distance B of precipitates in an optical laminate.

[0024] Figure 3 It is a schematic diagram for explaining a method for evaluating the maximum precipitation distance B of precipitates in an optical laminate.

[0025] Figure 4 It is a cross-sectional view schematically showing an example of an optical laminate that the kit for an image display panel of the present invention can include.

[0026] Figure 5 It is a cross-sectional view schematically showing an example of an optical laminate that the kit for an image display panel of the present invention can include.

[0027] Figure 6 It is a cross-sectional view schematically showing an example of an optical laminate that the kit for an image display panel of the present invention can include.

[0028] Figure 7 It is a cross-sectional view schematically showing an example of an optical laminate that the kit for an image display panel of the present invention can include.

[0029] Figure 8 It is a cross-sectional view schematically showing an example of an optical laminate that the kit for an image display panel of the present invention can include.

[0030] Figure 9A It is a cross-sectional view schematically showing an example of an image display panel of the present invention.

[0031] Figure 9B It is a cross-sectional view schematically showing an example of an image display panel of the present invention.

[0032] Figure 9C It is a cross-sectional view schematically showing an example of an image display panel of the present invention.

[0033] Figure 9D It is a cross-sectional view schematically showing an example of an image display panel of the present invention.

[0034] Figure 9E It is a cross-sectional view schematically showing an example of an image display panel of the present invention.

[0035] Figure 9F It is a cross-sectional view schematically showing an example of an image display panel of the present invention.

[0036] Figure 10 It is an observation image obtained for the image display panel of Example 1 to confirm the state of precipitates after the damp heat test.

[0037] Figure 11This is an observation image obtained for the image display panel of Example 4 to confirm the state of the precipitates after the damp heat test.

[0038] Figure 12 This is an observation image obtained for the image display panel of Example 6 to confirm the state of the precipitates after the damp heat test. Detailed implementation mode

[0039] The kit for an image display panel according to the first aspect of the present invention includes an optical laminate and a conductive paste. The optical laminate includes a polarizer containing iodine.

[0040] Among them, when a damp heat test is performed on the optical laminate having a cured layer of the conductive paste formed on the side surface at a temperature of 85°C, a relative humidity of 85%, and a test time of 240 hours, and the iodine-containing precipitates in the optical laminate after the damp heat test are evaluated,

[0041] The maximum precipitation distance of the precipitates in the direction perpendicular to the side surface from the side surface where the cured layer is formed is 700 μm or less.

[0042] In the second aspect of the present invention, for example, in the kit for an image display panel according to the first aspect, the maximum precipitation distance is 500 μm or less.

[0043] In the third aspect of the present invention, for example, in the kit for an image display panel according to the first or second aspect, the precipitates include a compound of iodine and a conductive component contained in the conductive paste.

[0044] In the fourth aspect of the present invention, for example, in the kit for an image display panel according to any one of the first to third aspects, the concentration of iodine in the polarizer is 5% by weight or less.

[0045] In the fifth aspect of the present invention, for example, in the kit for an image display panel according to any one of the first to fourth aspects, the optical laminate further includes an adhesive sheet.

[0046] In the sixth aspect of the present invention, for example, in the kit for an image display panel according to the fifth aspect, the water absorption rate of the adhesive sheet is 1.5% by weight or more.

[0047] The image display panel according to the seventh aspect of the present invention includes an image forming layer and an optical laminate disposed on the visible side of the image forming layer, and has a conduction structure on the side surface of the optical laminate.

[0048] The optical laminate includes a polarizer containing iodine.

[0049] The conduction structure includes a cured layer of a conductive paste.

[0050] When performing a damp heat test at an implementation temperature of 85°C, a relative humidity of 85%, and a test time of 240 hours, and evaluating the iodine-containing precipitate in the above optical laminate after the above damp heat test,

[0051] The maximum precipitation distance of the precipitate in the direction perpendicular to the above side surface starting from the above side surface where the above conduction structure is formed is 700 μm or less.

[0052] In the eighth aspect of the present invention, for example, in the image display panel of the seventh aspect, the above image forming layer is an embedded type image display unit.

[0053] The image display device of the ninth aspect of the present invention includes the image display panel of the seventh or eighth aspect.

[0054] Hereinafter, the details of the present invention will be described. The following description is not intended to limit the present invention to a specific embodiment.

[0055] [Kit for Image Display Panel]

[0056] The kit for an image display panel of the present embodiment includes an optical laminate and a conductive paste. An example of the optical laminate that the kit for an image display panel of the present embodiment may include is shown in Figure 1 . Figure 1 The optical laminate 10(10A) includes a polarizer 1 and a transparent protective film 2 disposed on the polarizer 1. The optical laminate 10 can function as a polarizing film 3. The polarizer 1 contains iodine, typically a film obtained by adsorbing iodine on a hydrophilic polymer film such as a polyvinyl alcohol film, a partially formalized polyvinyl alcohol film, or a partially saponified ethylene-vinyl acetate copolymer film and performing unidirectional stretching. However, as long as it contains iodine, the polarizer 1 is not limited to the above examples.

[0057] The optical laminate 13 having a cured layer 11 of the conductive paste formed on the side surface 12 can be formed using the optical laminate 10A and the conductive paste contained in the kit for an image display panel of the present embodiment (see Figure 2 ). When performing a damp heat test (hereinafter referred to as damp heat test A) on the optical laminate 13 at a temperature of 85°C, a relative humidity of 85%, and a test time of 240 hours and evaluating the iodine-containing precipitate in the optical laminate 13 after the damp heat test A, the maximum precipitation distance of the precipitate (hereinafter referred to as maximum precipitation distance B) is 700 μm or less.

[0058] Regarding the evaluation method of the maximum precipitation distance B, refer to Figure 3The description will be given below. An optical laminate 13 to be the object of a damp heat test is prepared by forming a cured layer 11 on a side surface 12 of the optical laminate 10. The cured layer 11 can be formed by applying an electrically conductive paste to the side surface 12 and drying the coating layer. The coating layer can also be dried by heating. Although the drying depends on the type of the electrically conductive paste, for example, it can be carried out by heating at 90 to 150°C. When the used electrically conductive paste has specified drying conditions, it can also be carried out according to the specified conditions. The cured layer 11 is preferably formed so as to cover the entire thickness direction of the optical laminate 10, and the width in the direction along the side surface 12 is 30 mm or more and the thickness from the side surface 12 is 100 μm or more.

[0059] Next, a damp heat test A is carried out on the prepared optical laminate 13. The conditions of the damp heat test A are set to a temperature of 85°C, a relative humidity of 85%, and a test time of 240 hours. The damp heat test A can be carried out by accommodating the optical laminate 13 in a thermo-hygrostat capable of maintaining the above temperature and relative humidity. The damp heat test A can also be carried out in a state where the optical laminate 13 is fixed to a substrate. The substrate can be a glass sheet, an image forming layer, or a substrate contained in the image forming layer (for example, a first transparent substrate and a second transparent substrate described later). The glass constituting the glass sheet is preferably an alkali-free glass. The fixing to the substrate can be carried out using an adhesive sheet (for example, the adhesive sheet 4 described later). Next, looking down from a direction perpendicular to the main surface of the optical laminate 13, the precipitation state of the iodine-containing precipitate 14 near the side surface 12 on which the cured layer 11 is formed is observed. The observation is carried out in a range of at least 10 mm or more in the direction along the side surface 12. The observation can be carried out using a magnifying observation device such as an optical microscope. Typically, the precipitate 14 is observed in the form of one or more strip-shaped objects extending along a direction D perpendicular to the side surface 12 from the side surface 12 on which the cured layer 11 is formed. For the precipitate 14A that extends the most along the direction D from the side surface 12 among the observed precipitates 14, the distance from the side surface 12 to the tip of the precipitate 14A is measured, and this distance can be determined as the maximum precipitation distance B. It should be noted that the conclusion that the precipitate 14 contains iodine can be confirmed by various known evaluation methods, such as energy dispersive X-ray fluorescence analysis (EDX).

[0060] According to the research of the present inventors, when the conditions of the damp heat test are set to severe conditions in an image display panel having a conduction structure formed on the side surface of the optical laminate, deterioration of the displayed image peculiar to the panel occurs, mainly due to the precipitation of precipitates 14 from the side surface 12 where the conduction structure is formed. Under the above severe damp heat conditions, the iodine contained in the polarizer 1 may easily migrate inside the polarizer 1, at the interface between the polarizer 1 and other adjacent layers, or inside other adjacent layers to the polarizer 1, resulting in the formation of precipitates 14. The precipitate 14 contains, for example, a compound of iodine and a conductive component contained in the conductive paste. Examples of the conductive component are metals. However, the precipitate 14 is not limited to the above examples as long as it contains iodine and can be observed by the above evaluation method. The image display panel kit of the present embodiment, in which the precipitation that can form the precipitate 14 is suppressed, is suitable for manufacturing an image display panel having excellent environmental resistance.

[0061] The maximum precipitation distance B can be 650 μm or less, 600 μm or less, 550 μm or less, 500 μm or less, 450 μm or less, 400 μm or less, 350 μm or less, 300 μm or less, 250 μm or less, 200 μm or less, 150 μm or less, 100 μm or less, 50 μm or less, 30 μm or less, 20 μm or less, and further can be 10 μm or less. The maximum precipitation distance B can also be 0 μm, in other words, it can be an image display panel kit in which no precipitate 14 is precipitated even after the damp heat test A.

[0062] The maximum precipitation distance B may vary in various ways depending on, for example, the constitution of the polarizer 1, the constitution of the conductive paste, and the constitution of the optical laminate 10. Examples of the constitution of the polarizer 1 that may affect the maximum precipitation distance B are the concentration of iodine in the polarizer 1 and the thickness of the polarizer 1. Examples of the constitution of the conductive paste that may affect the maximum precipitation distance B are the type of conductive component contained in the conductive paste, the content rate of the conductive component in the conductive paste, and the degree of hydrophilicity of the surface of the cured layer 11. Examples of the constitution of the optical laminate 10 that may affect the maximum precipitation distance B are the ratio of the thickness of the polarizer 1 to the thickness of the optical laminate 10, and the constitution of the other layer in the case where the optical laminate 10 further includes other layers in addition to the polarizer 1. Examples of the other layer are a transparent protective film, and the adhesive sheet and the optical film described later. According to the research of the present inventors, for example, a low moisture permeability of the transparent protective film 2 can contribute to the suppression of the migration of iodine in a humid and hot environment and the resulting suppression of the maximum precipitation distance B. In addition, a high water absorbency of the adhesive sheet can contribute to the suppression of the maximum precipitation distance B. Furthermore, according to the research, the type and content rate of additives that can be included in the other layer may affect the maximum precipitation distance B. An example of the additive is an antistatic agent and a conductive polymer. For example, an additive containing a metal and / or metal ion (for example, a lithium ion) may hinder the reaction of forming the precipitate 14 from iodine.

[0063] The thickness of the polarizer 1 is, for example, 100 μm or less, and can be 90 μm or less, 80 μm or less, 70 μm or less, 60 μm or less, 50 μm or less, 40 μm or less, 30 μm or less, 25 μm or less, and further can be 20 μm or less. The lower limit of the thickness of the polarizer 1 is, for example, 1 μm or more, and can be 3 μm or more, 5 μm or more, 6 μm or more, 7 μm or more, 8 μm or more, 9 μm or more, and further can be 10 μm or more.

[0064] The concentration of iodine in the polarizer 1 is, for example, 10 wt% or less, and can be 9 wt% or less, 8 wt% or less, 7 wt% or less, 6 wt% or less, 5 wt% or less, 4.5 wt% or less, 4 wt% or less, 3.5 wt% or less, 3 wt% or less, 2.5 wt% or less, and further can be 2 wt% or less. The lower limit of the iodine concentration is, for example, 0.5 wt% or more, and can be 1 wt% or more, and further can be 1.5 wt% or more. The concentration of iodine in the polarizer 1 can be evaluated by EDX.

[0065] Figure 1 The optical laminate 10A includes a transparent protective film 2. In the optical laminate 10A, the polarizer 1 and the transparent protective film 2 are laminated so as to be in contact with each other. The transparent protective film 2 can have a function of protecting the polarizer 1.

[0066] The transparent protective film 2 can be made of, for example, a thermoplastic resin. Examples of the thermoplastic resin that can be used for the transparent protective film 2 are cellulose resins such as cellulose triacetate, polyester resins, polyethersulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth)acrylic resins, cyclic polyolefin resins (norbornene resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixed resins thereof. The transparent protective film 2 can be a film of a thermosetting resin or an ultraviolet curable resin such as (meth)acrylic, urethane, acrylic urethane, epoxy, or silicone. The transparent protective film 2 can contain one or more arbitrary additives.

[0067] Figure 1 The optical laminate 10A includes one transparent protective film 2 disposed on one surface of the polarizer 1. As Figure 4 shown, the optical laminate 10 (10B) of the present embodiment may also include two transparent protective films 2 (2A, 2B) respectively disposed on two main surfaces of the polarizer 1. In other words, the polarizer 1 can be disposed between the two transparent protective films 2A and 2B. Figure 4 The polarizer 1 of is in contact with each of the transparent protective films 2A and 2B. The materials of the transparent protective films 2A and 2B can be the same or different. For example, one of the transparent protective films 2A (or 2B) on one side can be a thermoplastic resin film, and the transparent protective film 2B (or 2A) on the other side can be a thermosetting resin film or an ultraviolet curable resin film.

[0068] The transparent protective film 2 can also have optical properties such as an antiglare property and an antireflection property. The transparent protective film 2 can be a film that functions as a retardation film.

[0069] A hard coat can also be provided on the surface of the transparent protective film 2 opposite to the surface on the polarizer side. In addition, the opposite surface can also be subjected to various treatments for the purposes of antireflection, antiadhesion, diffusion, antiglare, etc.

[0070] The polarizer 1 and the transparent protective film 2 can be bonded together with an adhesive. Examples of the adhesive are various adhesives such as water-based, solvent-based, hot melt, free radical curable, and cationic curable adhesives. Preferred adhesives are water-based adhesives and free radical curable adhesives. However, as long as it is optically transparent, the adhesive is not limited to the above examples.

[0071] The thickness of the transparent protective film 2 can be appropriately determined, but from the viewpoints of strength, processability, etc., operability, and thin film properties, it can be about 10 to 200 μm.

[0072] The thickness of the polarizing film 3 is, for example, 10 μm to 500 μm. The total light transmittance of the polarizing film 3 is not particularly limited, and is, for example, 30% to 50%.

[0073] Conductive paste typically contains a binder resin and conductive particles dispersed in the binder resin. In the conductive paste containing conductive particles, the main conductive component is usually the conductive particles. Examples of the binder resin are thermosetting resins. Examples of the thermosetting resins are epoxy resins, silicone resins, polyester resins, and polyurethane resins. Examples of the conductive particles are metal particles, metal oxide particles, and carbon particles. Examples of metals that can be contained in the conductive particles are gold, platinum, silver, copper, aluminum, nickel, zinc, lithium, magnesium, and cobalt. The conductive particles can be particles of the above various metals or particles of their oxides. However, as long as it can be used for an image display panel, the conductive paste, the binder resin, the conductive particles, and the metals that can be contained in the conductive particles are not limited to the above examples.

[0074] The conductive paste may further contain materials other than the binder resin and the conductive particles, such as additives.

[0075] The content rate of the conductive component in the conductive paste is, for example, 47% by weight or more, and can be 49% by weight or more, 50% by weight or more, 52% by weight or more, 54% by weight or more, 55% by weight or more, 56% by weight or more, and further can be 57% by weight or more. The upper limit of the content rate is, for example, 80% by weight or less, and can be 75% by weight or less, 73% by weight or less, 70% by weight or less, 69% by weight or less, 67% by weight or less, 65% by weight or less, 63% by weight or less, and further can be 60% by weight or less.

[0076] The water contact angle of the conductive paste is, for example, 90° or more, and can be 91° or more, 92° or more, 93° or more, 94° or more, and further can be 95° or more. The upper limit of the contact angle is, for example, 115° or less, and can be 113° or less, 111° or less, 110° or less, 108° or less, 106° or less, 105° or less, 103° or less, 101° or less, and further can be 100° or less. By using a conductive paste having a contact angle that is somewhat larger, moisture permeation into the conductive structure in a humid and hot environment can be suppressed. Therefore, the conductive paste having the above contact angle is suitable for suppressing the formation of compounds of iodine and the conductive components contained in the conductive paste. The contact angle can be measured as follows: A cured layer 11 of the conductive paste is formed on the surface of a glass sheet, 10 μL of pure water is dropped on its surface, and the contact angle is measured in the form of the contact angle of the water droplet after 5 minutes from the dropping according to the droplet method specified in Japanese Industrial Standard (hereinafter referred to as JIS) R3257.

[0077] The volume resistivity of the cured layer 11 formed from the conductive paste is, for example, 1×10 -4 Ω·m or less, and can be 8×10 -5Below Ω·m, 5×10 -5 Below Ω·m, 3×10 -5 Below Ω·m, and further can be 1×10 -5 Below Ω·m. The lower limit of the volume resistivity is, for example, 1×10 -2 Above Ω·m. The volume resistivity can be measured in accordance with JIS K6271:2008.

[0078] The optical laminate 10 is not limited to Figure 1 and Figure 4 Examples. The optical laminate 10 may also include other layers in addition to the polarizer 1 and the transparent protective film 2. An example of the optical laminate 10 including other layers is shown in Figure 5 . Figure 5 The optical laminate 10C of

[0079] further includes an adhesive sheet 4. The optical laminate 10C has a laminated structure in which the transparent protective film 2, the polarizer 1, and the adhesive sheet 4 are laminated in this order. The adhesive sheet 4 is in contact with the polarizer 1. The optical laminate 10C is also a polarizing film with an adhesive sheet.

[0080] The adhesive sheet 4 includes a (meth)acrylic polymer (A) as a base polymer. The adhesive sheet 4 may include a (meth)acrylic polymer (A) as a main component. The adhesive sheet 4 containing a (meth)acrylic polymer (A) as a main component may be a layer formed from an adhesive composition (B) containing a (meth)acrylic polymer (A) as a main component. In addition, the adhesive sheet 4 containing a (meth)acrylic polymer (A) as a main component may be a layer formed from a photocurable composition (C) containing a monomer group containing a (meth)acrylic monomer and / or a partial polymer of the monomer group. In this specification, (meth)acrylate refers to acrylate and / or methacrylate. The main component means the component with the largest content rate. The content rate of the main component is, for example, 50% by weight or more, and can be 60% by weight or more, 70% by weight or more, and further can be 80% by weight or more.

[0081] <(Meth)acrylic polymer (A)>

[0082] (Meth)acrylic polymer (A) may have a structural unit derived from an alkyl (meth)acrylate. The structural unit derived from an alkyl (meth)acrylate may be the main structural unit in (meth)acrylic polymer (A). In this specification, the main structural unit means the structural unit with the largest content rate in the polymer. The content rate of the main structural unit is, for example, 50% by weight or more, may be 60% by weight or more, 70% by weight or more, and further may be 80% by weight or more.

[0083] The number of carbon atoms of the alkyl group in the alkyl (meth)acrylate is not particularly limited, and is, for example, 1 to 30. The alkyl group may be linear, branched, or cyclic. Examples of the alkyl group are methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, hexyl, cyclohexyl, heptyl, 2-ethylhexyl, isooctyl, nonyl, decyl, isodecyl, dodecyl, isotetradecyl, lauryl, tridecyl, pentadecyl, hexadecyl, heptadecyl, and octadecyl. The alkyl (meth)acrylate may be used alone or two or more thereof may be used in combination. In the case of using two or more in combination, the average number of carbon atoms of the alkyl group is preferably 3 to 9. The alkyl (meth)acrylate is preferably butyl acrylate.

[0084] In (meth)acrylic polymer (A), when the structural unit derived from an alkyl (meth)acrylate is the main structural unit, its content rate may be 50% by weight or more, 60% by weight or more, 70% by weight or more, and further may be 80% by weight or more.

[0085] (Meth)acrylic polymer (A) may have a structural unit derived from a (meth)acrylate represented by the following chemical formula (1). The structural unit derived from the (meth)acrylate of formula (1) may be the main structural unit in (meth)acrylic polymer (A). R in formula (1) 2 is a hydrogen atom or a methyl group, R in formula (1) 3 is an alkyl group, the alkyl group may be linear or may have a branch, R 3 is preferably a linear alkyl group, examples of R 3 are a methyl group and an ethyl group, and n in formula (1) is an integer of 1 to 15.

[0086] [Chemical formula 1]

[0087]

[0088] Examples of the (meth)acrylate of formula (1) are 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, and methoxytriethylene glycol (meth)acrylate. The structural unit derived from the (meth)acrylate of formula (1) can contribute to the improvement of the water absorbency of the adhesive sheet 4.

[0089] In the case where the structural unit derived from the (meth)acrylate of formula (1) is the main structural unit in the (meth)acrylic polymer (A), its content rate can be 40% by weight or more, 45% by weight or more, 50% by weight or more, 55% by weight or more, 60% by weight or more, 65% by weight or more, 70% by weight or more, 75% by weight or more, and further can be 80% by weight or more.

[0090] Other examples of the monomer capable of forming the (meth)acrylic polymer (A) are at least one monomer selected from an aromatic ring-containing monomer, an amide group-containing monomer, a carboxyl group-containing monomer, and a hydroxyl group-containing monomer. In other words, the (meth)acrylic polymer (A) can have a structural unit derived from at least one monomer selected from an aromatic ring-containing monomer, an amide group-containing monomer, a carboxyl group-containing monomer, and a hydroxyl group-containing monomer. These monomers can be used alone, or two or more of them can be used in combination.

[0091] (Meth)acrylic polymer (A) can have a structural unit derived from a carboxyl group-containing monomer. A carboxyl group-containing monomer is a compound that contains a carboxyl group in its structure and contains a polymerizable unsaturated double bond such as (meth)acryloyl group, vinyl group, etc. Examples of the carboxyl group-containing monomer are (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. Among these, from the viewpoints of copolymerizability, price, and improvement of the adhesive properties of the adhesive sheet, acrylic acid is preferred.

[0092] (Meth)acrylic polymer (A) can have a structural unit derived from an aromatic ring-containing monomer. An aromatic ring-containing monomer is a compound that contains an aromatic ring structure in its structure and contains a polymerizable unsaturated double bond such as (meth)acryloyl group, vinyl group, etc. Examples of the aromatic ring are a benzene ring, a naphthalene ring, and a biphenyl ring. The aromatic ring-containing monomer is preferably an aromatic ring-containing (meth)acrylate.

[0093] Examples of the aromatic ring-containing (meth)acrylate esters include benzyl (meth)acrylate, phenyl (meth)acrylate, o-phenylphenol (meth)acrylate, phenoxymethyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxypropyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, ethylene oxide-modified nonylphenol (meth)acrylate, ethylene oxide-modified cresol (meth)acrylate, phenol ethylene oxide-modified (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, methoxybenzyl (meth)acrylate, chlorobenzyl (meth)acrylate, tolyl (meth)acrylate, styryl (meth)acrylate, etc., (meth)acrylate esters having a benzene ring; hydroxyethylated β-naphthol acrylate, 2-naphthyl ethyl (meth)acrylate, 2-naphthyloxyethyl acrylate, 2-(4-methoxy-1-naphthyloxy)ethyl (meth)acrylate, etc., (meth)acrylate esters having a naphthalene ring; biphenyl (meth)acrylate, etc., aromatic ring-containing (meth)acrylate esters having a biphenyl ring. Among these, from the viewpoints of improving the adhesion characteristics and durability of the adhesive sheet, benzyl (meth)acrylate and phenoxyethyl (meth)acrylate are preferred, and benzyl acrylate is more preferred.

[0094] (Meth)acrylic polymer (A) may have a structural unit derived from an amide group-containing monomer. The amide group-containing monomer is a compound that contains an amide group in its structure and contains a polymerizable unsaturated double bond such as a (meth)acryloyl group or a vinyl group. Examples of the amide group-containing monomer include acrylamide monomers such as (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N-isopropylacrylamide, N-methyl (meth)acrylamide, N-butyl (meth)acrylamide, N-hexyl (meth)acrylamide, N-hydroxymethyl (meth)acrylamide, N-hydroxymethyl-N-propyl (meth)acrylamide, aminomethyl (meth)acrylamide, aminoethyl (meth)acrylamide, mercaptomethyl (meth)acrylamide, mercaptoethyl (meth)acrylamide, etc.; N-acryloyl heterocyclic monomers such as N-(meth)acryloylmorpholine, N-(meth)acryloylpiperidine, N-(meth)acryloylpyrrolidine, etc.; N-vinyl lactam monomers containing N-vinyl such as N-vinylpyrrolidone, N-vinyl-ε-caprolactam, etc. Among these, from the viewpoint of improving the durability of the adhesive sheet, N-vinyl lactam monomers are preferred.

[0095] (Meth)acrylic polymer (A) may have a structural unit derived from a hydroxyl group-containing monomer. The hydroxyl group-containing monomer is a compound that contains a hydroxyl group in its structure and a polymerizable unsaturated double bond such as a (meth)acryloyl group or a vinyl group. Examples of the hydroxyl group-containing monomer include hydroxyl group-containing (meth)acrylic acid alkyl esters such as 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, and 12-hydroxydodecyl (meth)acrylate; and hydroxyl group-containing (meth)acrylic acid cycloalkyl esters such as methyl (4-hydroxymethylcyclohexyl)acrylate. Among these, 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate are preferred.

[0096] In (meth)acrylic polymer (A), the total content of the structural units derived from at least one monomer selected from an aromatic ring-containing monomer, an amide group-containing monomer, a carboxyl group-containing monomer, and a hydroxyl group-containing monomer is, for example, 0 to 30% by weight, may be 0.1 to 20% by weight, and further may be 0.1 to 10% by weight. However, the content is not limited to the above examples.

[0097] When (meth)acrylic polymer (A) has a structural unit derived from a carboxyl group-containing monomer, the content of this structural unit is not particularly limited. For example, it is 0.1% by weight or more, may be 1% by weight or more, 2% by weight or more, 3% by weight or more, and further may be 4% by weight or more. The upper limit of the content is, for example, 25% by weight or less, may be 20% by weight or less, and further may be 10% by weight or less. (Meth)acrylic polymer (A) may also not have a structural unit derived from a carboxyl group-containing monomer.

[0098] When (meth)acrylic polymer (A) has a structural unit derived from an aromatic ring-containing monomer, the content of this structural unit is not particularly limited. For example, it is 3 to 25% by weight, may be 22% by weight or less, and further may be 20% by weight or less. The lower limit of the content may be 8% by weight or more, and further may be 12% by weight or more. (Meth)acrylic polymer (A) may also not have a structural unit derived from an aromatic ring-containing monomer.

[0099] When (meth)acrylic polymer (A) has a structural unit derived from an amide group-containing monomer, the content of this structural unit is not particularly limited. For example, it is 0.1 to 10% by weight, may be 0.2 to 8% by weight, and further may be 0.6 to 6% by weight. (Meth)acrylic polymer (A) may also not have a structural unit derived from an amide group-containing monomer.

[0100] When the (meth)acrylic polymer (A) has a structural unit derived from a hydroxyl group-containing monomer, the content rate of the structural unit is not particularly limited. For example, it is 1% by weight or less, may be 0.5% by weight or less, and further may be 0.1% by weight or less. The (meth)acrylic polymer (A) may also not have a structural unit derived from a hydroxyl group-containing monomer.

[0101] (The (meth)acrylic polymer (A) may further have a structural unit derived from a comonomer other than the above-mentioned monomers. The comonomer can be used, for example, for the purpose of improving the adhesiveness and heat resistance of the adhesive sheet. The comonomer can be used alone or two or more of them can be used in combination.

[0102] The comonomer usually has a polymerizable functional group containing an unsaturated double bond such as (meth)acryloyl or vinyl. Examples of the comonomer include acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride; caprolactone adducts of acrylic acid; sulfonic acid group-containing monomers such as allyl sulfonic acid, 2-(meth)acrylamide-2-methylpropanesulfonic acid, (meth)acrylamidopropanesulfonic acid, and (meth)acrylic acid sulfopropyl ester; phosphoric acid group-containing monomers such as 2-hydroxyethyl acryloyl phosphate; (meth)acrylic acid alkylaminoalkyl esters such as (meth)acrylic acid aminoethyl ester, (meth)acrylic acid N,N-dimethylaminoethyl ester, and (meth)acrylic acid tert-butylaminoethyl ester; succinimide monomers such as N-(meth)acryloxymethylene succinimide, N-(meth)acryloyl-6-oxohexamethylene succinimide, and N-(meth)acryloyl-8-oxooctamethylene succinimide; maleimide monomers such as N-cyclohexyl maleimide, N-isopropyl maleimide, N-dodecyl maleimide, and N-phenyl maleimide; itaconimide monomers such as N-methyl itaconimide, N-ethyl itaconimide, N-butyl itaconimide, N-octyl itaconimide, N-2-ethylhexyl itaconimide, N-cyclohexyl itaconimide, and N-dodecyl itaconimide; vinyl monomers such as vinyl acetate and vinyl propionate; cyanoacrylate monomers such as acrylonitrile and methacrylonitrile; epoxy group-containing (meth)acrylates such as (meth)acrylic acid glycidyl ester; diol (meth)acrylates such as polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, methoxyethylene glycol (meth)acrylate, and methoxypolypropylene glycol (meth)acrylate; (meth)acrylate monomers such as (meth)acrylic acid tetrahydrofurfuryl ester, fluorine-containing (meth)acrylate, polysiloxane (meth)acrylate, and 2-methoxyethyl acrylate; silane monomers containing silicon atoms such as 3-acryloyloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 4-vinylbutyltrimethoxysilane, 4-vinylbutyltriethoxysilane, 8-vinyloctyltrimethoxysilane, 8-vinyloctyltriethoxysilane, 10-methacryloyloxydecyltrimethoxysilane, 10-acryloyloxydecyltrimethoxysilane, 10-methacryloyloxydecyltriethoxysilane, and 10-acryloyloxydecyltriethoxysilane.

[0103] Other examples of comonomers are polyfunctional monomers having two or more unsaturated double bonds such as tripropylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, 1,6 - hexanediol di(meth)acrylate, bisphenol A diglycidyl ether di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and caprolactone - modified dipentaerythritol hexa(meth)acrylate.

[0104] When the (meth)acrylic polymer (A) has a structural unit derived from a comonomer, the content rate of this structural unit is, for example, 10% by weight or less, may be 7% by weight or less, and further may be 5% by weight or less. The (meth)acrylic polymer (A) may also not have a structural unit derived from a comonomer.

[0105] The weight - average molecular weight of the (meth)acrylic polymer (A) is generally 300,000 - 4,000,000. From the viewpoint of durability, the weight - average molecular weight of the (meth)acrylic polymer (A) is preferably 1,000,000 or more, and may also be 1,500,000 or more. The weight - average molecular weight of the (meth)acrylic polymer (A) may be 3,000,000 or less, and may also be 2,000,000 or less. From the aspect of heat resistance, a weight - average molecular weight of 300,000 or more is preferred. When the weight - average molecular weight is 4,000,000 or less, there is a tendency that the adhesive sheet is not likely to harden and peeling is not likely to occur. The weight - average molecular weight (Mw) / number - average molecular weight (Mn) representing the molecular weight distribution is preferably 1.8 - 10, more preferably 1.8 - 7, and further preferably 1.8 - 5. From the aspect of durability, a molecular weight distribution (Mw / Mn) of 10 or less is preferred. The weight - average molecular weight and the molecular weight distribution (Mw / Mn) can be determined by GPC (gel permeation chromatography) and calculated as values converted to polystyrene.

[0106] The (meth)acrylic polymer (A) can be formed by various known polymerization methods such as solution polymerization, radiation polymerization using electron beams, ultraviolet rays (UV), bulk polymerization, and emulsion polymerization. The polymerization is typically radical polymerization. The (meth)acrylic polymer (A) can be any copolymer such as a random copolymer, a block copolymer, a graft copolymer, etc. However, the formation method of the (meth)acrylic polymer (A) is not limited to the above examples. It should be noted that when the adhesive sheet is a layer formed from the photocurable composition (C), the (meth)acrylic polymer (A) is mainly formed by radiation polymerization using electron beams, UV, etc.

[0107] As the polymerization solvent for solution polymerization, known polymerization solvents such as ethyl acetate and toluene can be used, for example. Solution polymerization can be carried out, for example, under an inert gas stream such as nitrogen while using a polymerization initiator. The polymerization conditions are, for example, 50 to 70 °C and 5 to 30 hours.

[0108] The polymerization initiator, chain transfer agent, emulsifier, etc. for radical polymerization are not particularly limited and can be appropriately selected. The weight average molecular weight of the (meth)acrylic polymer (A) can be controlled according to the types and amounts of the polymerization initiator and chain transfer agent, as well as the polymerization conditions, etc.

[0109] Examples of the polymerization initiator are azo initiators such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-amidinopropane) dihydrochloride, 2,2'-azobis[2-(5-methyl-2-imidazolin-2-yl)propane] dihydrochloride, 2,2'-azobis(2-methylpropionamidine) disulfate, 2,2'-azobis(N,N'-dimethyleneisobutyramidine), 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine] hydrate (for example, VA-057 manufactured by Wako Pure Chemical Industries, Ltd.); persulfates such as potassium persulfate and ammonium persulfate; peroxides such as bis(2-ethylhexyl) peroxydicarbonate, bis(4-tert-butylcyclohexyl) peroxydicarbonate, di-sec-butyl peroxydicarbonate, tert-butyl peroxyneodecanoate, tert-hexyl peroxypivalate, tert-butyl peroxypivalate, dilauroyl peroxide, di-n-octanoyl peroxide, 1,1,3,3-tetramethylbutyl 2-ethylhexanoate peroxide, bis(4-methylbenzoyl) peroxide, benzoyl peroxide, tert-butyl peroxyisobutyrate, 1,1-bis(tert-hexylperoxy)cyclohexane, tert-butyl hydroperoxide, hydrogen peroxide, etc.; redox initiators combining peroxides and reducing agents such as a combination of persulfate and sodium bisulfite, and a combination of peroxide and sodium ascorbate. However, the polymerization initiator is not limited to the above examples.

[0110] The polymerization initiator can be used alone or two or more kinds can be used in combination. The total amount of the polymerization initiator used is, for example, 0.005 to 1 part by weight, and can also be 0.02 to 0.5 part by weight, relative to 100 parts by weight of the monomer component.

[0111] Examples of the chain transfer agent are dodecyl mercaptan, glycidyl mercaptan, mercaptoacetic acid, 2-mercaptoethanol, thioglycolic acid, 2-ethylhexyl thioglycolate, and 2,3-dimercapto-1-propanol. The chain transfer agent can be used alone or two or more kinds can be used in combination. The total amount of the chain transfer agent used is, for example, 0.1 part by weight or less, relative to 100 parts by weight of the monomer component.

[0112] In radiation polymerization, polymerization is carried out by irradiating a monomer group with radiation such as an electron beam or UV to form a (meth)acrylic polymer (A). In the case of forming an adhesive sheet from a photocurable composition (C), polymerization is carried out by irradiating the photocurable composition (C) with light to form a (meth)acrylic polymer (A). In the case of radiation polymerization using an electron beam, the use of a photoinitiator is not particularly necessary. In the case of radiation polymerization using UV, a photoinitiator can be used because of advantages such as the ability to shorten the polymerization time. The photoinitiator can be used alone or two or more thereof can be used in combination.

[0113] Examples of the photoinitiator are various photoinitiators such as benzoin ethers, acetophenones, α-hydroxy ketones, photoactive oximes, benzoins, benzils, benzophenones, ketals, thioxanthones, etc. However, the photoinitiator is not limited to the above examples. The amount of the photoinitiator is, for example, 0.05 to 1.5 parts by weight, and can also be 0.1 to 1 part by weight, relative to 100 parts by weight of the monomer component.

[0114] <Adhesive composition (B)>

[0115] The adhesive composition (B) is typically a composition capable of forming an adhesive sheet by drying. In this case, the adhesive sheet formed from the adhesive composition (B) usually becomes a solvent type (also called a thermosetting type).

[0116] The adhesive composition (B) may contain a crosslinking agent. Examples of the crosslinking agent that can be contained in the adhesive composition (B) are isocyanate crosslinking agents, peroxide crosslinking agents, epoxy crosslinking agents, imine crosslinking agents, and polyfunctional metal chelates. The adhesive composition (B) preferably contains an isocyanate crosslinking agent and a peroxide crosslinking agent, and more preferably contains an isocyanate crosslinking agent.

[0117] As the isocyanate crosslinking agent, a compound having at least two isocyanate groups (isocyanate compound) can be used. The number of isocyanate groups contained in the isocyanate compound is preferably 3 or more. The upper limit of the number of isocyanate groups is not particularly limited, and is, for example, 5. Examples of the isocyanate compound are aromatic isocyanate compounds, alicyclic isocyanate compounds, and aliphatic isocyanate compounds. The isocyanate crosslinking agent is preferably a compound capable of self-polymerization by reaction with water.

[0118] Examples of aromatic isocyanate compounds are phthalic diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 2,2'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-toluidine diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, and xylylene diisocyanate.

[0119] Examples of alicyclic isocyanate compounds are 1,3-cyclopentene diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated toluene diisocyanate, and hydrogenated tetramethylxylylene diisocyanate.

[0120] Examples of aliphatic isocyanate compounds are trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate.

[0121] The isocyanate crosslinking agent can be a polymer (dimer, trimer, pentamer, etc.) of the above isocyanate compounds, an adduct obtained by addition with a polyol such as trimethylolpropane, a urea-modified product, a biuret-modified product, a urethane-modified product, an isocyanurate-modified product, a carbodiimide-modified product, and a urethane prepolymer obtained by addition with a polyether polyol, a polyester polyol, an acrylic polyol, a polybutadiene polyol, a polyisoprene polyol, etc.

[0122] The isocyanate crosslinking agent is preferably an aromatic isocyanate compound and its derivative, more preferably a toluene diisocyanate and its derivative, that is, a toluene diisocyanate-based (TDI-based) crosslinking agent. From the viewpoint of reactivity, the TDI-based crosslinking agent is more suitable than a xylylene diisocyanate and its derivative, that is, a xylylene diisocyanate-based (XDI-based) crosslinking agent. The isocyanate crosslinking agent can contain an adduct of a polyol and toluene diisocyanate as the TDI-based crosslinking agent. Specific examples of the adduct are trimethylolpropane / toluene diisocyanate trimer adduct.

[0123] Isocyanate crosslinking agents can be commercially available products. Examples of commercially available products are Millionate MT, Millionate MTL, Millionate MR-200, Millionate MR-400, Coronate L, Coronate HL, Coronate HX (above, manufactured by Tosoh Corporation), Takenate D-101E, Takenate D-110N, Takenate D-120N, Takenate D-140N, Takenate D-160N, Takenate D-165N, Takenate D-170HN, Takenate D-178N, Takenate 500, Takenate 600 (above, manufactured by Mitsui Chemicals, Inc.). Among these, Takenate D-101E is preferred.

[0124] The isocyanate crosslinking agents can be used alone or two or more of them can be used in combination.

[0125] With respect to 100 parts by weight of the (meth)acrylic polymer (A), the compounding amount of the isocyanate crosslinking agent in the adhesive composition (B) is, for example, 0.01 to 20 parts by weight. The lower limit of the compounding amount can be 0.05 parts by weight or more, 0.1 parts by weight or more, and further can be 0.15 parts by weight or more. The upper limit of the compounding amount can be 15 parts by weight or less, 13 parts by weight or less, 10 parts by weight or less, 8 parts by weight or less, 5 parts by weight or less, 3 parts by weight or less, 2 parts by weight or less, 1 part by weight or less, and further can be 0.5 parts by weight or less.

[0126] With respect to 100 parts by weight of the (meth)acrylic polymer (A), the compounding amount of the crosslinking agent other than isocyanates in the adhesive composition (B) is preferably 2 parts by weight or less, more preferably 1 part by weight or less. From the viewpoint of the durability of the adhesive sheet, the adhesive composition (B) may substantially contain no crosslinking agent other than isocyanates, particularly epoxy crosslinking agents.

[0127] The adhesive composition (B) may further contain known additives. Examples of the additives are silane coupling agents, solvents, colorants, pigments, powders, dyes, surfactants, plasticizers, tackifiers, surface lubricants, leveling agents, softeners, antioxidants, anti-aging agents, light stabilizers, ultraviolet absorbers, polymerization inhibitors, inorganic or organic fillers, metal powders, particles, and foils. In the range where it can be controlled, redox types added with reducing agents can also be used. However, the additives are not limited to the above examples. With respect to 100 parts by weight of the (meth)acrylic polymer (A), the total blending amount of the additives is, for example, 10 parts by weight or less, can be 5 parts by weight or less, and further can be 1 part by weight or less.

[0128] The adhesive composition (B) may contain a silane coupling agent as an additive. Examples of the silane coupling agent are epoxy group-containing silane coupling agents such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; amino group-containing silane coupling agents such as 3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutyl)propylamine, N-phenyl-γ-aminopropyltrimethoxysilane; (meth)acryloyl group-containing silane coupling agents such as 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane; and isocyanate group-containing silane coupling agents such as 3-isocyanatopropyltriethoxysilane.

[0129] When the adhesive composition (B) contains a silane coupling agent, with respect to 100 parts by weight of the (meth)acrylic polymer (A), its blending amount is, for example, 5 parts by weight or less, can be 3 parts by weight or less, 1 part by weight or less, 0.5 part by weight or less, 0.4 part by weight or less, 0.2 part by weight or less, and further can be 0.1 part by weight or less. The lower limit of the blending amount is not particularly limited and is, for example, 0.02 part by weight or more. The adhesive composition (B) may also not contain a silane coupling agent.

[0130] The adhesive composition (B) may also substantially not contain a photocuring agent such as a photoinitiator.

[0131] The adhesive sheet 4 can be formed, for example, by drying a coating film of the adhesive composition (B) provided on a substrate. Drying can be carried out by heating. As the substrate, a release film can be used. The adhesive sheet 4 formed on the release film can be transferred, for example, to other layers that can be included in the optical laminate 10 such as the polarizer 1 and the transparent protective film 2. The substrate can be other layers that can be included in the optical laminate 10 such as the polarizer 1 and the transparent protective film 2. However, the method for forming the adhesive sheet 4 from the adhesive composition (B) is not limited to the above examples.

[0132] The release film can be a known film that can be used when forming a solvent-based adhesive sheet.

[0133] The drying temperature of the coating film is, for example, 130°C or lower, and can be 125°C or lower, 120°C or lower, 110°C or lower, and further can be 100°C or lower. The drying temperature is, for example, 60°C or higher, and can also be 80°C or higher. The drying time of the coating film can be appropriately adjusted according to the composition of the adhesive composition (B), and is, for example, 30 seconds to 300 seconds, 40 seconds to 240 seconds, and further can be 60 seconds to 180 seconds.

[0134] <Photocurable composition (C)>

[0135] The photocurable composition (C) is a composition capable of forming an adhesive sheet by irradiation with light. The adhesive sheet formed from the photocurable composition (C) usually becomes a photocurable type. The photocurable composition (C) contains, for example, a monomer group containing (meth)acrylic monomers and / or a partial polymer of the monomer group. The content rate of the (meth)acrylic component, that is, the (meth)acrylic monomer and its partial polymer, in the photocurable composition can be 50% by weight or more, 60% by weight or more, 70% by weight or more, and further can be 80% by weight or more. In this case, an acrylic adhesive sheet mainly composed of a (meth)acrylic polymer and its crosslinked product can be formed.

[0136] Examples of the monomers that the monomer group can contain are the same as those described above in the description of the (meth)acrylic polymer (A).

[0137] The photocurable composition (C) usually contains a photoinitiator. Examples of the photoinitiator are photo radical generators that generate radicals by visible light and / or ultraviolet light having a wavelength shorter than 450 nm. Examples of the photoinitiator are the same as those described above in the description of the (meth)acrylic polymer (A). The blending amount of the photoinitiator in the photocurable composition (C) is, for example, 0.02 to 10 parts by weight, and can also be 0.05 to 5 parts by weight, based on 100 parts by weight in total of the monomer group and its partial polymer.

[0138] The photocurable composition (C) can contain a crosslinking agent. Examples of the crosslinking agent are polyfunctional monomers having two or more polymerizable functional groups in one molecule. The polyfunctional monomer can be a (meth)acrylic monomer. Examples of the polyfunctional monomer are monomers having two or more C=C bonds in one molecule, and monomers having one or more C=C bonds and one or more polymerizable functional groups such as epoxy groups, aziridinyl groups, oxazolinyl groups, hydrazide groups, and hydroxymethyl groups in one molecule. The polyfunctional monomer is preferably a monomer having two or more C=C bonds in one molecule.

[0139] Examples of crosslinking agents that the photocurable composition (C) may contain are (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,2-ethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol diacrylate (NDDA), 1,12-dodecanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate and other polyfunctional acrylates (ester compounds formed from polyhydric alcohols and (meth)acrylic acid, etc.); allyl (meth)acrylate, vinyl (meth)acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, urethane acrylate, butyl di(meth)acrylate, hexyl di(meth)acrylate. The polyfunctional monomer is preferably a polyfunctional acrylate, more preferably trimethylolpropane tri(meth)acrylate, hexanediol di(meth)acrylate, dipentaerythritol hexa(meth)acrylate.

[0140] The compounding amount of the crosslinking agent varies depending on the molecular weight, number of functional groups, etc., but is, for example, 5 parts by weight or less, or may be 3 parts by weight or less, 2 parts by weight or less, 1 part by weight or less, and further may be 0.5 part by weight or less, relative to every 100 parts by weight of the total of the monomer group and its partial polymers. The lower limit of the compounding amount is, for example, 0.01 part by weight or more, and further may be 0.05 part by weight% or more.

[0141] The photocurable composition (C) may also contain additives other than those described above. Examples of additives are chain transfer agents, silane coupling agents, viscosity modifiers, tackifiers, plasticizers, softeners, anti-aging agents, fillers, colorants, antioxidants, surfactants, antistatic agents, and ultraviolet absorbers. However, the additives are not limited to the above examples. Examples of the silane coupling agent are the same as those described above in the description of the adhesive composition (B).

[0142] The content rate of the solvent in the photocurable composition (C) is, for example, 5% by weight or less, may be 4% by weight or less, 3% by weight or less, 2% by weight or less, 1% by weight or less, and further may be 0.5% by weight or less. The photocurable composition (C) may substantially not contain a solvent. Substantially not containing a solvent means that it is allowed to contain solvents, etc. from additives, etc. at a content rate of, for example, 0.1% by weight or less, preferably 0.05% by weight or less, more preferably 0.01% by weight or less.

[0143] The viscosity of the photocurable composition (C) is preferably 5 to 100 poise.

[0144] The adhesive sheet 4 can be formed, for example, by irradiating a coating film of a photocurable composition (C) provided on a substrate. As the substrate, a release film can be used. The adhesive sheet 4 formed on the release film can be transferred, for example, to other layers that the optical laminate 10 may include. However, the method of forming the adhesive sheet 4 from the photocurable composition (C) is not limited to the above example.

[0145] The irradiated light is, for example, visible light or ultraviolet light having a wavelength shorter than 450 nm. The light may include light having a wavelength in the same region as the absorption wavelength of the photoinitiator contained in the photocurable composition. Light obtained by cutting off short-wavelength light of 300 nm or less through a filter or the like can be irradiated. The light source of the light is, for example, a light irradiation device equipped with an ultraviolet irradiation lamp. Examples of the ultraviolet irradiation lamp are ultraviolet LEDs, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, xenon lamps, microwave-excited mercury lamps, black lights, chemical lamps, germicidal lamps, low-pressure discharge mercury lamps, and excimer lasers. Two or more ultraviolet irradiation lamps can also be combined.

[0146] The irradiation intensity of the light is, for example, 1 to 20 mW / cm 2 . The cumulative light amount of the light is, for example, 100 to 5000 mJ / cm 2 .

[0147] The thickness of the adhesive sheet 4 is, for example, 1 to 50 μm, and can be 2 to 30 μm, 2 to 25 μm, and further can be 5 to 20 μm.

[0148] The water absorption rate of the adhesive sheet 4 is, for example, 1% by weight or more, and can be 1.1% by weight or more, 1.2% by weight or more, 1.3% by weight or more, 1.4% by weight or more, 1.5% by weight or more, 1.6% by weight or more, 1.7% by weight or more, 1.8% by weight or more, 1.9% by weight or more, 2% by weight or more, 2.1% by weight or more, and further can be 2.2% by weight or more. The upper limit of the water absorption rate is, for example, 10% by weight or less. Since the adhesive sheet 4 having a water absorption rate within the above range has a large ability to absorb moisture in a humid and hot environment, it can contribute to the suppression of the maximum precipitation distance B. The water absorption rate can be evaluated by thermogravimetric analysis (TGA) at a given temperature and relative humidity. The evaluation can be performed using a humidified TGA measuring device. The conditions of temperature and relative humidity for evaluating the water absorption rate are set in order as (1) 100 °C, 0% RH, 60 minutes, (2) 85 °C, 0% RH, 120 minutes, and (3) 85 °C, 85% RH, 240 minutes. Let the weight at the end of (1) measured by TGA be the initial weight W0 (g), and the weight at the end of (3) be the humidified weight W1 (g). The water absorption rate can be obtained by the formula: (W1 - W0) / W0 × 100%. The weight of the test piece for evaluating the water absorption rate is preferably set to about 10 to 100 mg.

[0149] The adhesive sheet 4 can be of a low-resistance type. The surface resistivity of the low-resistance type adhesive sheet 4 is, for example, 9×10 11 Ω / square or less, and can be 5×10 11 Ω / square or less, 1×10 11 Ω / square or less, 9×10 10 Ω / square or less, 5×10 10 Ω / square or less, 1×10 10 Ω / square or less, 9×10 9 Ω / square or less, 5×10 9 Ω / square or less, and further can be 1×10 9 Ω / square or less. The lower limit of the surface resistivity is, for example, 1×10 4 Ω / square or more. The surface resistivity of the adhesive sheet 4 within the above range can also contribute to a more practical operation of the touch panel. The surface resistivity can be evaluated, for example, by a high-resistance resistivity meter (as an example, manufactured by MITSUBISHI CHEMICAL ANALYTECH, Hiresta series).

[0150] The adhesive sheet 4 can contain at least one selected from an antistatic agent and a conductive polymer. The antistatic agent and the conductive polymer can contribute to the reduction of the surface resistivity of the adhesive sheet. Examples of the antistatic agent are salt plasma compounds. The ionic compound can be an ionic liquid that is liquid at normal temperature (25°C). The ionic compound is suitable for forming the adhesive sheet 4 having excellent optical transparency.

[0151] Examples of the cation constituting the ionic compound are metal ions and ions. Examples of the metal ions are alkali metal ions and alkaline earth metal ions. Examples of the alkali metal ions are lithium ions, sodium ions, and potassium ions, and can be lithium ions. Examples of the alkaline earth metal ions are magnesium ions and calcium ions. However, the metal ions are not limited to the above examples.

[0152] Examples of the ions are ions in which at least 1 atom selected from a nitrogen atom, a phosphorus atom, and a sulfur atom is positively charged (+). The ions can be organic ions, and in this case, can be ions of a cyclic organic compound or ions of a chain organic compound. The cyclic organic compound can be aromatic or non-aromatic such as aliphatic. Examples of the ions include quaternary ammonium ions such as N-ethyl-N,N-dimethyl-N-(2-methoxyethyl)ammonium ion, N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium ion, N-ethyl-N,N-dimethyl-N-propylammonium ion, N-methyl-N,N,N-trioctylammonium ion, N,N,N-trimethyl-N-propylammonium ion, tetrabutylammonium ion, tetramethylammonium ion, tetrahexylammonium ion, and N-methyl-N,N,N-tributylammonium ion; N-alkylpyridines substituted with an alkyl group having 4 to 16 carbon atoms such as pyridine ions; 1,3-alkylmethylimidazoles substituted with an alkyl group having 2 to 10 carbon atoms (e.g., ethyl) ions, 1,2-dimethyl-3-alkylimidazoles substituted with an alkyl group having 2 to 10 carbon atoms such as imidazole ions; ions, pyrrolidine ions, pyridazine ions, pyrimidine ions, pyrazine ions, pyrazole ions, thiazole ions, azole ions, triazole ions, and piperidine ions. However, the ions are not limited to the above examples.

[0153] Examples of the anions constituting the ionic compound are fluoride ion, chloride ion, bromide ion, iodide ion, perchlorate (ClO4 - ), hydroxide (OH - ), carbonate (CO3 2- ), nitrate (NO3 - ), sulfonate (SO4 - ), methylbenzenesulfonate (CH3(C6H4)SO3 - ), p-toluenesulfonate (CH3C6H4SO3 - ), carboxybenzenesulfonate (COOH(C6H4)SO3 - ), trifluoromethanesulfonate (CF3SO2 - ), benzoate (C6H5COO - ), acetate (CH3COO - ), trifluoroacetate (CF3COO - ), tetrafluoroborate (BF4 - ), tetrabenzylborate (B(C6H5)4 - ), hexafluorophosphate (PF6 -) Tris(pentafluoroethyl)trifluorophosphate (P(C2F5)3F3 - ) Bis(fluorosulfonyl)imide (N(SO2F)2 - ) Bis(trifluoromethanesulfonyl)imide (N(SO2CF3)2 - ) Bis(pentafluoroethanesulfonyl)imide (N(SOC2F5)2 - ) Bis(pentafluoroethylcarbonyl)imide (N(COC2F5)2 - ) Bis(perfluorobutanesulfonyl)imide (N(SO2C4F9)2 - ) Bis(perfluorobutylcarbonyl)imide (N(COC4F9)2 - ) Tris(trifluoromethanesulfonyl)methide (C(SO2CF3)3 - ) And tris(trifluoromethanecarbonyl)methide (C(SO2CF3)3 - ). However, the anion is not limited to the above examples.

[0154] The antistatic agent may contain an anion containing a sulfur atom. Examples of anions containing a sulfur atom are bis(fluorosulfonyl)imide (N(SO2F)2 - ) And bis(trifluoromethanesulfonyl)imide (N(SO2CF3)2 - ).

[0155] The antistatic agent may be an organic salt. Additionally, the antistatic agent may be a lithium salt, and as the cation and anion, it may be a lithium organic salt containing a lithium ion and an organic ion, respectively.

[0156] Specific examples of the antistatic agent are 1-ethyl-3-methylimidazole Bis(fluorosulfonyl)imide, lithium bis(trifluoromethane)sulfonimide (LiTFSi), ethylmethylpyrrolidine Bis(trifluoromethanesulfonyl)imide (EMPTFSi) and tributylmethylammonium bis(trifluoromethanesulfonyl)imide (TBMATFSi).

[0157] The antistatic agent may also not contain a phosphorus atom.

[0158] Examples of the conductive polymer are polythiophene, polyaniline, polypyrrole, polyquinoxaline, polyacetylene, poly(phenylene vinylene), polynaphthalene, and their derivatives. The conductive polymer is preferably polythiophene, polyaniline, and their derivatives, and more preferably polythiophene derivatives.

[0159] The conductive polymer may have a hydrophilic functional group. Examples of the hydrophilic functional group are sulfo group, amino group, amide group, imide group, hydroxyl group, mercapto group, hydrazino group, carboxyl group, sulfate group, phosphate group, and their salts (e.g., quaternary ammonium salt group).

[0160] From the viewpoints of conductivity and chemical stability, the conductive polymer is preferably poly(3,4-disubstituted thiophene). Examples of poly(3,4-disubstituted thiophene) are poly(3,4-alkylenedioxythiophene) and poly(3,4-dialkoxythiophene), and poly(3,4-alkylenedioxythiophene) is preferred. Poly(3,4-alkylenedioxythiophene) has, for example, a structural unit represented by the following formula (I).

[0161] [Chemical formula 2]

[0162]

[0163] R in formula (I) 1 is, for example, an alkylene group having 1 to 4 carbon atoms. The alkylene group may be linear or may have a branched chain. Examples of the alkylene group are methylene, 1,2-ethylene, 1,3-propylene, 1,4-butylene, 1-methyl-1,2-ethylene, 1-ethyl-1,2-ethylene, 1-methyl-1,3-propylene, and 2-methyl-1,3-propylene, and methylene, 1,2-ethylene, and 1,3-propylene are preferred, and 1,2-ethylene is more preferred. The conductive polymer may be poly(3,4-ethylenedioxythiophene) (PEDOT).

[0164] Examples of the dopant are polyanions. In the case where the conductive polymer is polythiophene (or its derivative), the polyanion can form an ion pair with polythiophene (or its derivative). The polyanion is not particularly limited, and examples thereof are carboxylic acid polymers such as polyacrylic acid, polymaleic acid, and polymethacrylic acid; sulfonic acid polymers such as polystyrene sulfonic acid, polyvinyl sulfonic acid, and polyisoprene sulfonic acid. The polyanion may be a copolymer of vinyl carboxylic acids or vinyl sulfonic acids and other monomeric compounds. Examples of the other monomeric compounds are (meth)acrylate compounds; aromatic vinyl compounds such as styrene and vinylnaphthalene. The polyanion is preferably polystyrene sulfonic acid (PSS). An example of the conductive polymer as a complex with the dopant is a complex of poly(3,4-ethylenedioxythiophene) and polystyrene sulfonic acid (PEDOT / PSS).

[0165] With respect to 100 parts by weight of the (meth)acrylic polymer (A), the total amount of at least one selected from the antistatic agent and the conductive polymer in the adhesive sheet 4 is, for example, less than 25 parts by weight, and may be 20 parts by weight or less, 15 parts by weight or less, 10 parts by weight or less, and further may be 9 parts by weight or less. The lower limit of the amount is, for example, 0.005 parts by weight or more.

[0166] Other examples of the other layers that can be included in the optical laminate 10 are optical films. Figure 6The optical laminate 10D further includes an optical film 5. The optical laminate 10D has a laminated structure in which a transparent protective film 2, a polarizer 1, the optical film 5, and an adhesive sheet 4 are laminated in sequence. The optical film 5 is in contact with the polarizer 1. The optical laminate 10D is also an optical film with an adhesive sheet.

[0167] Examples of the optical film 5 are retardation films. However, the optical film 5 is not limited to retardation films. The retardation film has, for example, a refractive index characteristic represented by the formula nx > ny and has a slow axis. However, the retardation film is not limited to the above examples. The retardation film may have, for example, a refractive index characteristic represented by the formula nz > nx = ny and has various refractive index characteristics known as retardation films. In the present specification, nx, ny, and nz are the refractive index in the direction (slow axis) in which the in-plane refractive index of the film reaches the maximum, the refractive index in the direction (fast axis) orthogonal to the slow axis in the plane, and the refractive index in the thickness direction, respectively.

[0168] Hereinafter, the retardation film that can be the optical film 5 will be described. The retardation film may have a Re(550) of 10 nm or more, 30 nm or more, 50 nm or more, 80 nm or more, and further may have 100 nm or more. Re(550) is the in-plane phase difference of the retardation film with respect to light having a wavelength of 550 nm. The in-plane phase difference can be obtained by setting the thickness of the retardation film to d (nm) and using the formula Re = (nx - ny) × d.

[0169] The Re(550) of the retardation film may be 100 nm to 180 nm, 110 to 170 nm, 120 to 160 nm, and further may be 135 nm to 155 nm. In this case, the retardation film can function as a so-called λ / 4 wave plate. The Re(550) of the retardation film may be 180 nm to 320 nm, 200 to 290 nm, and further may be 230 to 280 nm. In this case, the retardation film can function as a so-called λ / 2 wave plate. The optical film 5 may be a layer that can function as a λ / 4 wave plate or a λ / 2 wave plate. When the optical film 5 is a layer that can function as a λ / 4 wave plate, the optical laminate 10D may be an elliptically polarized film with an adhesive sheet or a circularly polarized film with an adhesive sheet.

[0170] The retardation film may be an alignment fixing layer of a liquid crystal compound (hereinafter, referred to as a liquid crystal alignment fixing layer). In other words, the optical film 5 may be a liquid crystal alignment fixing layer. In the present specification, the liquid crystal alignment fixing layer means a layer in which a liquid crystal compound is aligned in a given direction in the layer and its alignment state is fixed. It should be noted that the liquid crystal alignment fixing layer includes an alignment curing layer obtained by curing a liquid crystal monomer. The liquid crystal alignment fixing layer is suitable for obtaining a desired phase difference while reducing the thickness.

[0171] In a liquid crystal alignment fixing layer, typically, rod-shaped liquid crystal compounds are aligned (homogeneous alignment) along a given direction. Examples of liquid crystal compounds are nematic liquid crystals and discotic liquid crystals. The liquid crystal compound may be a liquid crystal polymer or a liquid crystal monomer. The liquid crystal monomer may have polymerizability and / or crosslinkability.

[0172] Specific examples of the liquid crystal monomer are polymerizable mesogenic compounds described in each of the gazettes of JP-T 2002-533742, EP358208, EP66137, WO93 / 22397, EP0261712, DE19504224, DE4408171, GB2280445, etc. Examples of the polymerizable mesogenic compound are LC242 manufactured by BASF, E7 manufactured by Merck, and LC-Sillicon-CC3767 manufactured by Wacker-Chem. The liquid crystal monomer is preferably a nematic monomer.

[0173] The retardation film as the liquid crystal alignment fixing layer can be formed by coating a coating liquid containing a liquid crystal compound on the surface of a substrate film that has been subjected to an alignment treatment, aligning the liquid crystal compound along the direction corresponding to the alignment treatment, and fixing the alignment state. A release film can be used as the substrate. The retardation film formed on the release film can be transferred to other layers that the optical laminate 10 may include, for example. However, the method for forming the retardation film as the liquid crystal alignment fixing layer is not limited to the above examples.

[0174] For other specific examples of the liquid crystal compound and details of the method for forming the liquid crystal alignment fixing layer, reference can be made to JP-A 2006-163343. However, the retardation film as the liquid crystal alignment fixing layer and the method for forming it are not limited to the content described in this gazette.

[0175] The retardation film can be a stretched resin film. Examples of the resin capable of forming the retardation film are polycarbonate, polyvinyl acetal, cycloolefin resin, acrylic resin, and cellulose ester resin. The retardation film can be a stretched resin film containing polycarbonate.

[0176] The retardation film can be a retardation film for antireflection, a retardation film for viewing angle compensation, or a tilted alignment retardation film for viewing angle compensation.

[0177] Other examples of other layers that the optical laminate 10 may include are a surface protective film (cover film). Figure 7 The optical laminate 10E further includes a surface protective film 6. The optical laminate 10E has a laminated structure in which a surface protective film 6, a transparent protective film 2, a polarizer 1, an optical film 5, and an adhesive sheet 4 are laminated in sequence. The surface protective film 6 is located on the outermost layer on the side opposite to the adhesive sheet 4 side.

[0178] The surface protective film 6 can have the function of protecting the outermost layer during the circulation and storage of the optical laminate 10, and also in the state where the optical laminate 10 is introduced into an image display panel or an image display device. Additionally, the surface protective film 6 can function as a window to the external space in the state where it is introduced into the image display device. The surface protective film 6 is typically a resin film. Resins that can form the surface protective film 6 are, for example, polyesters such as polyethylene terephthalate (PET), polyolefins such as polyethylene and polypropylene, acrylics, cycloolefins, polyimides, and polyamides, and polyesters are preferred. However, the surface protective film 6 is not limited to the above examples. The surface protective film 6 can be a glass film or a laminated film containing a glass film. The surface protective film 6 can also be subjected to surface treatments such as antiglare, antireflection, and antistatic treatments. The surface protective film 6 can be joined to the transparent protective film 2 by an adhesive or an adhesive sheet. The thickness of the surface protective film 6 is, for example, 10 to 80 μm.

[0179] Other examples of other layers that can be included in the optical laminate 10 are release liners. Figure 8 The optical laminate 10F further includes a release liner 7. The optical laminate 10F has a laminated structure in which a surface protective film 6, a transparent protective film 2, a polarizer 1, an optical film 5, an adhesive sheet 4, and a release liner 7 are laminated in sequence. The release liner 7 is in contact with the adhesive sheet 4. By peeling off the release liner 7, the optical laminate 10F can be used, for example, as an optical film with an adhesive sheet.

[0180] The release liner 7 is, for example, a film, paper, woven fabric, non-woven fabric, porous material, net, foam, foil, or a laminate thereof formed from a resin, paper, fiber, metal, or a composite material thereof. Examples of the resin are polyethylene, polypropylene, polybutene, polybutadiene, polymethylpentene, polyvinyl chloride, vinyl chloride copolymer, polyethylene terephthalate, polybutylene terephthalate, polyurethane, ethylene-vinyl acetate copolymer, and polyester. However, the release liner 7 is not limited to the above examples. Additionally, the materials constituting the release liner 7 and the resins that can be constituted are not limited to the above examples.

[0181] The thickness of the release liner 7 is, for example, 5 to 200 μm, and can be 5 to 100 μm. As needed, various surface treatments such as a release treatment, an antifouling treatment, and an antistatic treatment can be performed on the surface of the release liner 7. The release treatment can utilize various release agents such as silicone-based, fluorine-based, long-chain alkyl-based, fatty acid amide-based, or particles such as silica powder.

[0182] The optical laminate 10 can be circulated and stored, for example, in the form of a wound body obtained by winding a strip-shaped optical laminate, or in the form of a single-sheet optical laminate.

[0183] Typically, the optical laminate 10 can be used for an image display panel or an image display device. In other words, the optical laminate 10 can be an optical laminate for an image display panel or an image display device. Examples of the image display panel are a liquid crystal panel, and EL panels such as an organic EL panel and an inorganic EL panel. Examples of the image display device are a liquid crystal display, and EL displays such as an organic EL display and an inorganic EL display. The use of the optical laminate 10 is not limited to the above examples. In addition, the image display panel and the image display device that can use the optical laminate 10 are not limited to the above examples.

[0184] The kit for an image display panel of the present embodiment may also include other components in addition to the optical laminate 10 and the conductive paste.

[0185] The types of the image display panel that can use the kit for an image display panel of the present embodiment are as described above.

[0186] [Image display panel]

[0187] Examples of the image display panel of the present embodiment are shown in Figure 9A . Figure 9A The image display panel 100(100A) includes a liquid crystal cell 30A as an image forming layer, and an optical laminate 10(10A) disposed on the visible side of the liquid crystal cell 30A. The image display panel 100 is a liquid crystal panel. A conduction structure 20 is provided on a side surface 12 of the optical laminate 10. The optical laminate 10 includes a polarizer 1 containing iodine. The conduction structure 20 includes a cured layer of the conductive paste. For the image display panel 100, when evaluating the iodine-containing precipitate in the optical laminate 10 after performing a damp heat test at an implementation temperature of 85 °C, a relative humidity of 85%, and a test time of 240 hours, the maximum precipitation distance B is 700 μm or less. Regarding the maximum precipitation distance B of the image display panel 100, including the preferred range, it can be the maximum precipitation distance B that can be obtained as the optical laminate 10 within the above range. The maximum precipitation distance B of the image display panel 100 can be obtained by performing the damp heat test A and the evaluation method of the maximum precipitation distance B described above for the optical laminate 10 taken out from the image display panel 100, or for the image display panel 100.

[0188] Figure 9AThe conductive structure 20 is provided in a manner that is in contact with all layers included in the optical stack 10. The conductive structure 20 is preferably provided at a ratio of 1% or more, preferably 3% or more, of the area of ​​the side surface of the optical stack 10. The upper limit of the ratio is, for example, 99% or less, and may be 95% or less. The conductive structure 20 is generally formed in a manner that electrically connects the optical stack 10 to other appropriate locations in the image display panel. The conductive structure 20 may be linear.

[0189] The liquid crystal cell 30A includes a liquid crystal layer 32, and a first transparent substrate 31 and a second transparent substrate 33 sandwiching the liquid crystal layer 32. Figure 9A In FIG. 3 , the electrodes in the liquid crystal cell 30A are omitted.

[0190] An example of the liquid crystal layer 32 is a layer containing liquid crystal molecules that are homogeneously aligned in the absence of an electric field. The liquid crystal layer 32 may be an IPS type liquid crystal layer. However, various types of liquid crystal layers such as TN type, STN type, π type, and VA type may also be used as the liquid crystal layer 32. The thickness of the liquid crystal layer 32 is, for example, about 1.5 to 4 μm.

[0191] Examples of materials constituting the first transparent substrate 31 and the second transparent substrate 33 are glass and resin. Examples of resin are PET, polycycloolefin and polycarbonate. The thickness of the first transparent substrate 31 and the second transparent substrate 33 made of glass is, for example, about 0.1 to 1 mm. The thickness of the first transparent substrate 31 and the second transparent substrate 33 made of resin is, for example, about 10 to 200 μm. The first transparent substrate 31 and the second transparent substrate 33 may have an easy-adhesion layer and a hard coating layer on the surface.

[0192] The image forming layer may have a touch sensor built in. In other words, the image forming layer may be an embedded image display unit. An example of an image display panel having an embedded image display unit is shown in FIG. Figures 9B - 9F . Figures 9B - 9F The image display panels 100B to 100F include in-cell liquid crystal cells 30B to 30F as in-cell image display cells. The in-cell liquid crystal cells 30B to 30F include touch sensing electrode portions related to touch sensing and touch driving functions between the first transparent substrate 31 and the second transparent substrate 33 .

[0193] like Figure 9B , Figure 9C and Figure 9FAs shown, the touch sensing electrode portion 35 may be formed by a touch sensing electrode 36 and a touch driving electrode 37. The touch sensing electrode refers to a touch detection (receiving) electrode. The touch sensing electrode 36 and the touch driving electrode 37 may be formed into various patterns independently of each other. For example, when looking down at the inlaid liquid crystal cell 30B, the touch sensing electrode 36 and the touch driving electrode 37 may be formed into orthogonal patterns. Additionally, in Figure 9B , Figure 9C and Figure 9F , the touch sensing electrode 36 is disposed on the side (visible side) closer to the first transparent substrate 31 than the touch driving electrode 37, but the touch driving electrode 37 may also be disposed on the side (visible side) closer to the first transparent substrate 31 than the touch sensing electrode 36.

[0194] As Figure 9D and Figure 9E shown, the touch sensing electrode portion 38 may also be formed by integrating the touch sensing electrode and the touch driving electrode.

[0195] The touch sensing electrode portions 35 and 38 may be disposed between the liquid crystal layer 32 and the first transparent substrate 31 or the second transparent substrate 33. In the examples of Figure 9B and Figure 9D , the touch sensing electrode portions 35 and 38 are disposed between the liquid crystal layer 32 and the first transparent substrate 31 (closer to the visible side than the liquid crystal layer 32). In the examples of Figure 9C and Figure 9E , the touch sensing electrode portions 35 and 38 are disposed between the liquid crystal layer 32 and the second transparent substrate 33 (closer to the backlight side than the liquid crystal layer 32).

[0196] As Figure 9F shown, as the touch sensing electrode portion 35, the touch sensing electrode 36 is disposed between the liquid crystal layer 32 and the first transparent substrate 31, and the touch driving electrode 37 is disposed between the liquid crystal layer 32 and the second transparent substrate 33, respectively.

[0197] The driving electrodes of the touch sensing electrode portions 35 and 38 may share the electrodes for controlling the liquid crystal layer 32.

[0198] The touch sensing electrode portions 35 and 38, the touch sensing electrode 36, and the touch driving electrode 37 may have a known configuration.

[0199] The image display panel 100 may further include other layers in addition to the above. Examples of the other layers are a conductive layer and a color filter. The conductive layer has a surface resistivity of, for example, 1×10 -13 Ω / □ or less. The conductive layer may be disposed, for example, between the optical laminate 10 and the image forming layer. The image display panel 100 may also not include the conductive layer.

[0200] Figures 9A - 9F In the example of Figures 9A - 9F , an adhesive sheet 41 and a polarizing film 42 are further provided on the side of the image forming layer opposite to the side of the optical laminate 10. In the above example, the adhesive sheet 41 is in contact with the second transparent substrate 33, and the polarizing film 42 is in contact with the adhesive sheet 41. The transmission axis (or absorption axis) of the polarizing film 42 and the transmission axis (or absorption axis) of the polarizer 1 may be orthogonal to each other when the image display panel 100 is viewed from above.

[0201] The adhesive sheet 41 may have various configurations described in the description of the adhesive sheet 4. The adhesive sheet 41 and the adhesive sheet 4 may have the same configuration. However, the adhesive sheet 41 is not limited to the above example. The thickness of the adhesive sheet 41 is, for example, 1 to 100 μm, may be 2 to 50 μm, 2 to 40 μm, and further may be 5 to 35 μm.

[0202] The polarizing film 42 may have various configurations described in the description of the polarizing film 3. The polarizing film 42 and the polarizing film 3 may have the same configuration. However, the polarizing film 42 is not limited to the above example.

[0203] [Image display device]

[0204] The image display device of the present embodiment is, for example, a liquid crystal display device including an image display panel 100 as a liquid crystal panel and a lighting system. In the liquid crystal display device, the image display panel 100 is disposed, for example, closer to the visual side than the lighting system. The lighting system has, for example, a backlight or a reflector and irradiates light to the image display panel 100. However, the image display device of the present embodiment is not limited to the liquid crystal display device. The image display device may also be an EL display device such as an organic EL display device and an inorganic EL display device.

[0205] [Example]

[0206] Hereinafter, the present invention will be described in more detail by way of examples. The present invention is not limited to the examples shown below. It should be noted that parts and % in each example are based on weight. Hereinafter, all test conditions not specifically specified are 23 °C and 65% RH.

[0207] [Polarizer and polarizing film]

[0208] <Fabrication of polarizing films F1 to F3>

[0209] (40 μm TAC film with HC)

[0210] In a resin solution (manufactured by DIC Corporation, trade name: UNIDIC 17-806, solid content concentration: 80%) obtained by dissolving a UV-curable resin monomer or oligomer containing urethane acrylate as a main component in butyl acetate, 5 parts of a photopolymerization initiator (manufactured by BASF Corporation, trade name: IRGACURE 907) and 0.1 part of a leveling agent (manufactured by DIC Corporation, trade name: GRANDIC PC4100) were added per 100 parts of the solid content in the solution. Next, cyclopentanone and propylene glycol monomethyl ether were added to the solution at a ratio of 45:55 so that the solid content concentration in the solution reached 36%, and a hard coat forming material was prepared. The prepared hard coat forming material was applied to TJ40UL (manufactured by Fujifilm, raw material: triacetyl cellulose polymer, thickness: 40 μm) so that the thickness of the cured hard coat reached 7 μm, and a coating film was formed. The coating film was dried at 90 °C for 1 minute, and further irradiated with ultraviolet rays having a cumulative light amount of 300 mJ / cm 2 to cure the coating film and form a hard coat (HC), and a 40-μm TAC film with an HC was prepared.

[0211] (30-μm acrylic film)

[0212] 8000 g of methyl methacrylate (MMA), 2000 g of methyl 2-(hydroxymethyl)acrylate (MHMA), 10000 g of 4-methyl-2-pentanone (methyl isobutyl ketone, MIBK), and 5 g of n-dodecyl mercaptan were added to a 30-L kettle-type reactor equipped with a stirring device, a temperature sensor, a condenser, and a nitrogen inlet tube. Nitrogen was introduced therein, and at the same time, the temperature was raised to 105 °C. When reflux occurred, 5.0 g of tert-butyl peroxyisopropyl carbonate (Kayacarbon BIC-7, manufactured by Kayaku AKZO Corporation) as a polymerization initiator was added, and at the same time, a solution composed of 10.0 g of tert-butyl peroxyisopropyl carbonate and 230 g of MIBK was added dropwise over 4 hours. At the same time, solution polymerization was carried out at about 105 to 120 °C under reflux, and further aging was carried out for 4 hours.

[0213] 30 g of a stearyl phosphate / distearyl phosphate mixture (Phoslex A-18, manufactured by Sakai Chemical Industry Co., Ltd.) was added to the obtained polymer solution, and a cyclization condensation reaction was carried out at about 90 to 120 °C for 5 hours under reflux. Next, the obtained polymer solution was introduced into an exhaust-type twin-screw extruder (φ = 29.75 mm, L / D = 30) with a barrel temperature of 260 °C, a rotation speed of 100 rpm, a degree of vacuum of 13.3 to 400 hPa (10 to 300 mmHg), 1 rear vent, and 4 front vents at a treatment speed of 2.0 kg / h in terms of resin amount. In this extruder, a cyclization condensation reaction and devolatilization were further carried out, and extrusion was performed, whereby a transparent pellet containing an alicyclic polymer was obtained.

[0214] The obtained alicyclic polymer-containing product was measured by dynamic TG, and a mass reduction of 0.17 mass% was detected. In addition, the weight-average molecular weight of this alicyclic polymer-containing product was 133,000, the melt flow rate was 6.5 g / 10 min, and the glass transition temperature was 131 °C.

[0215] The obtained pellets were melt-kneaded and extruded with acrylonitrile-styrene (AS) resin (TOYO ASAS20, manufactured by Toyo Styrene Co., Ltd.) at a mass ratio of 90 / 10 using a single-screw extruder (screw φ 30 mm), whereby transparent pellets were obtained. The glass transition temperature of the obtained pellets was 127 °C.

[0216] Using a 50 mmφ single-screw extruder, the pellets were melt-extruded from a 400 mm-wide coat hanger die to produce a film with a thickness of 120 μm. Using a twin-screw stretching device, the produced film was stretched 2.0 times longitudinally and 2.0 times transversely at a temperature of 150 °C, whereby a stretched film (30 μm acrylic film) with a thickness of 30 μm was obtained. As a result of measuring the optical properties of this stretched film, the total light transmittance was 93%, the in-plane retardation Δnd was 0.8 nm, and the thickness-direction retardation Rth was 1.5 nm.

[0217] (Polarizing film F1)

[0218] Between rollers with different speed ratios, while dyeing a 45-μm thick polyvinyl alcohol film in an iodine solution at a temperature of 30°C and a concentration of 0.3% for 1 minute, it was stretched 3 times. Next, it was immersed in an aqueous solution at a temperature of 60°C containing 4% boric acid and 10% potassium iodide for 0.5 minutes while being stretched until the total draw ratio reached 6 times. Next, after washing by immersing it in an aqueous solution at a temperature of 30°C containing 1.5% potassium iodide for 10 seconds, it was dried at 50°C for 4 minutes, thereby obtaining a polarizer with a thickness of 18 μm. A 40-μm TAC film with HC (on the side of the triacetyl cellulose film) after saponification was adhered to one side of this polarizer using a polyvinyl alcohol-based adhesive. Further, a 30-μm acrylic film was adhered to the other side of the polarizer using a polyvinyl alcohol-based adhesive. Thereby, a polarizing film F1 was obtained.

[0219] (Polarizing films F2, F3)

[0220] The concentration of potassium iodide in the aqueous potassium iodide solution for immersion was changed, and except for this, polarizing films F2 and F3 with only different iodine concentrations from polarizing film F1 were obtained in the same manner as polarizing film F1.

[0221] <Fabrication of Polarizing Film F4>

[0222] Between rollers with different speed ratios, while dyeing an 80-μm thick polyvinyl alcohol film in an iodine solution at a temperature of 30°C and a concentration of 0.3% for 1 minute, it was stretched 3 times. Next, it was immersed in an aqueous solution at a temperature of 60°C containing 4% boric acid and 10% potassium iodide for 0.5 minutes while being stretched until the total draw ratio reached 6 times. Next, after washing by immersing it in an aqueous solution at a temperature of 30°C containing 1.5% potassium iodide for 10 seconds, it was dried at 50°C for 4 minutes, thereby obtaining a polarizer with a thickness of 28 μm. A 30-μm thick transparent protective film formed from a modified acrylic polymer having a lactone ring structure was adhered to one side of this polarizer using a polyvinyl alcohol-based adhesive. Further, a 47-μm thick transparent protective film having a hard coat (HC) formed on a triacetyl cellulose film (manufactured by Konica Minolta, Inc., trade name “KC4UY”) was adhered to the other side of the polarizer. Heating and drying were performed in an oven set at 70°C for 5 minutes, thereby fabricating a polarizing film F4.

[0223] <Fabrication of Polarizing Film F5>

[0224] (Polarizer)

[0225] One side of a substrate of an amorphous isophthalic acid copolyethylene terephthalate (IPA copolyester) film (water absorption rate: 0.75%, Tg: 75°C, thickness: 100 μm) was subjected to corona treatment, and an aqueous solution containing polyvinyl alcohol (degree of polymerization: 4200, saponification degree: 99.2 mol%) and acetoacetylated polyvinyl alcohol (degree of polymerization: 1200, acetoacetylation rate: 4.6%, saponification degree: 99.0 mol% or more, manufactured by Nippon Gohsei Chemical Industry Co., Ltd., trade name “GOHSEFIMER Z200”) in a ratio of 9:1 was coated on the corona-treated surface at 25°C and dried to form a polyvinyl alcohol resin layer with a thickness of 11 μm, and a laminate was produced.

[0226] The obtained laminate was subjected to free-end unidirectional stretching (auxiliary stretching treatment in a gas atmosphere) to 2.0 times in the longitudinal direction (length direction) between rollers with different circumferential speeds in an oven at 120°C. Next, the laminate was immersed in an insolubilization bath at a liquid temperature of 30°C (an aqueous boric acid solution obtained by mixing 4 parts of boric acid with 100 parts of water) for 30 seconds (insolubilization treatment). Next, it was immersed in a dyeing bath at a liquid temperature of 30°C (an aqueous iodine solution obtained by mixing 0.2 part of iodine and 1.0 part of potassium iodide with 100 parts of water) for 60 seconds (dyeing treatment). Next, it was immersed in a crosslinking bath at a liquid temperature of 30°C (an aqueous boric acid solution obtained by mixing 3 parts of potassium iodide and 3 parts of boric acid with 100 parts of water) for 30 seconds (crosslinking treatment). Next, the laminate was immersed in an aqueous boric acid solution at a liquid temperature of 70°C (an aqueous solution obtained by mixing 4 parts of boric acid and 5 parts of potassium iodide with 100 parts of water), and at the same time, unidirectional stretching (stretching treatment in an aqueous solution) was performed in the longitudinal direction (length direction) between rollers with different circumferential speeds so that the total stretching ratio reached 5.5 times. Next, the laminate was immersed in a cleaning bath at a liquid temperature of 30°C (an aqueous solution obtained by mixing 4 parts of potassium iodide with 100 parts of water) (cleaning treatment). Thus, a laminate containing a polarizer with a thickness of 5 μm was obtained.

[0227] (Adhesive)

[0228] 45 parts of acryloylmorpholine, 45 parts of 1,9-nonanediol diacrylate, 10 parts of an acrylic oligomer (ARUFONUP1190, manufactured by Toagosei Co., Ltd.) obtained by polymerizing (meth)acrylic acid monomers, 3 parts of a photoinitiator (IRGACURE907, manufactured by BASF), and 1.5 parts of a polymerization initiator (KAYACURE DETX-S, manufactured by Nippon Kayaku Co., Ltd.) were mixed to prepare an ultraviolet curable adhesive.

[0229] (Polarizing film F5)

[0230] On the surface of the polarizer of the laminate produced above, the ultraviolet curable adhesive was applied in such a way that the thickness of the cured adhesive layer reached 1 μm, and a 25-μm TAC film with HC (on the triacetyl cellulose film side) was laminated. The 25-μm TAC film with HC was produced by the same method as the above-mentioned 40-μm TAC film with HC. Next, ultraviolet rays were irradiated as active energy rays to cure the adhesive. For the ultraviolet irradiation, a metal halide lamp filled with gallium, an irradiation device: Light HAMMER10 manufactured by Fusion UV Systems, Inc., a valve: V valve, a peak illuminance: 1600 mW / cm 2 , and an accumulated irradiation dose of 1000 / mJ / cm 2 (wavelength 380 - 440 nm). The illuminance of the ultraviolet rays was measured using a Sola-Check system manufactured by Solatell. Next, the amorphous PET substrate was peeled off, and a polarizing film F3 using a thin polarizer was produced. The optical properties of the obtained polarizing film F3 were: a monomer transmittance of 42.8% and a degree of polarization of 99.99%.

[0231] <Iodine concentration of the polarizer>

[0232] The concentration (unit: wt%) of iodine contained in the polarizer was evaluated by the following method using EDX. For EDX, a fluorescent X-ray analyzer ZSX-PRIMUS IV (manufactured by Rigaku Corporation) was used.

[0233] (Determination of the conversion formula)

[0234] In EDX, the intensity of the fluorescent X-ray from iodine can be measured. The conversion formula for calculating the iodine concentration of the polarizer from the measured intensity of the fluorescent X-ray was determined by the following steps (1) - (3).

[0235] (1) A known amount of potassium iodide was dissolved in an aqueous solution of polyvinyl alcohol (PVA) to prepare 7 kinds of PVA aqueous solutions containing iodine with known concentrations. Each of the prepared PVA aqueous solutions was applied to a PET film, and after the coated film was dried and peeled off, specimens 1 - 7 of PVA films containing iodine with known concentrations were obtained. It should be noted that the iodine concentration (unit: wt%) of the prepared PVA film was calculated by the following mathematical formula 1. The amount of potassium iodide in the mathematical formula 1 is the amount of potassium iodide dissolved in the PVA aqueous solution. The PVA weight is the weight of PVA contained in the above aqueous solution. 127 and 166 are the molecular weights of iodine and potassium iodide, respectively.

[0236] [Mathematical formula 1]

[0237] Iodine concentration (wt%) = {amount of potassium iodide (g) / (amount of potassium iodide (g) + weight of PVA (g))} × (127 / 166)

[0238] (2) EDX was performed on Samples 1 to 7, and the peak intensity (unit: kcps) of the fluorescent X-ray having a wavelength corresponding to iodine was measured. In addition, the film thicknesses of Samples 1 to 7 were measured separately using a spectroscopic film thickness meter MCPD-1000 (manufactured by Otsuka Electronics Co., Ltd.).

[0239] (3) The peak intensity of the measured fluorescent X-ray was divided by the thickness (μm) of each sample to calculate the fluorescent X-ray intensity per unit thickness (kcps / μm). The iodine concentration and the fluorescent X-ray intensity per unit thickness of each sample are shown in Table 1 below.

[0240]

[0241] (4) Based on the results in Table 1, for each sample, a calibration curve was made with the fluorescent X-ray intensity per unit thickness on the horizontal axis and the iodine concentration on the vertical axis. Based on the made calibration curve, a conversion formula for obtaining the iodine concentration from the fluorescent X-ray intensity per unit thickness of the polarizer which is a PVA film was determined as shown in the following Mathematical Formula 2.

[0242] [Mathematical Formula 2]

[0243] Iodine concentration (wt%) = 14.474 × fluorescent X-ray intensity per unit thickness (kcps / μm)

[0244] (Evaluation of iodine concentration of polarizer)

[0245] The polarizing films F1 to F5 were immersed in a solvent (dichloromethane) that does not dissolve PVA to dissolve the TAC film and the acrylic film that are transparent protective films, and the polarizer was taken out. EDX was performed on the taken-out polarizer, and the peak intensity (unit: kcps) of the fluorescent X-ray having a wavelength corresponding to iodine was measured. In addition, different from EDX, the film thickness of the taken-out polarizer was measured using a spectroscopic film thickness meter MCPD-1000 (manufactured by Otsuka Electronics). The iodine concentration of the polarizer was obtained from the measured film thickness, peak intensity, and the conversion formula of Mathematical Formula 2 above. The evaluation results are shown in Table 2 below.

[0246] [Table 2]

[0247]

[0248] [Adhesive composition]

[0249] <Weight average molecular weight of (meth)acrylic polymer>

[0250] (Meth)acrylic polymers were determined for their weight-average molecular weight (Mw) by GPC (gel permeation chromatography). The Mw / Mn of (meth)acrylic polymers was also determined in the same manner.

[0251] · Analytical device: HLC-8120GPC manufactured by Tosoh Corporation

[0252] · Column: G7000H manufactured by Tosoh Corporation XL + GMH XL + GMH XL

[0253] · Column size: Each 7.8 mmφ × 30 cm, total 90 cm

[0254] · Column temperature: 40 °C

[0255] · Flow rate: 0.8 mL / min

[0256] · Injection volume: 100 μL

[0257] · Eluent: Tetrahydrofuran

[0258] · Detector: Differential refractometer (RI)

[0259] · Standard sample: Polystyrene

[0260] (Preparation of (meth)acrylic polymer A1)

[0261] A monomer mixture containing 60 parts of methoxyethyl acrylate (MEA), 39 parts of butyl acrylate (BA), and 1 part of 4-hydroxybutyl acrylate (HBA) was added to a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen inlet tube, and a condenser. Further, 0.1 part of 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator was added together with 100 parts of ethyl acetate with respect to 100 parts of the monomer mixture. While slowly stirring the mixture, nitrogen was introduced to displace the air in the flask with nitrogen. Next, the temperature of the liquid in the flask was maintained at around 55 °C and a polymerization reaction was carried out for 8 hours to prepare a solution of (meth)acrylic polymer A1 having a weight-average molecular weight (Mw) of 1.95 million and Mw / Mn = 3.9.

[0262] The composition of (meth)acrylic polymer A1 is summarized in Table 3 below.

[0263]

[0264] (Preparation of adhesive composition B1)

[0265] Based on 100 parts by solid content of the solution of (meth)acrylic polymer A1, 5 parts of 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide (ELEXCEL AS-110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), 0.6 parts of an isocyanate crosslinking agent (Coronate L manufactured by Tosoh Corporation, trimethylolpropane tolylene diisocyanate) as a crosslinking agent, and 0.1 part of benzoyl peroxide (NYPER BMT manufactured by NOF Corporation) were blended to prepare an adhesive composition B1. The composition of the adhesive composition B1 is summarized in Table 4 below.

[0266]

[0267]

[0268] [Optical laminate (polarizing film with adhesive sheet)]

[0269] Using the above-prepared polarizing films F1 to F5 and the adhesive composition B1, optical laminates X1 to X5 were produced. The production of the optical laminates was carried out in the following order. On one side of a PET film (release liner; MRF38, manufactured by Mitsubishi Chemical Polyester Film) treated with a silicone-based release agent, the adhesive composition was coated so that the thickness of the dried adhesive sheet reached 20 μm. Next, the formed coating film was dried at 155 °C for 1 minute, thereby forming an adhesive sheet on the surface of the release liner. Next, the adhesive sheet formed on the release liner was transferred to the surface of the polarizing film to produce an optical laminate (polarizing film with adhesive sheet). For the produced optical laminates X1 to X5, the combinations of the polarizing film and the adhesive composition, and the transfer surface of the adhesive sheet in the polarizing film are shown in Table 5 below. It should be noted that the shape of the produced optical laminates was set to a rectangular shape with a width of 50 mm and a height of 50 mm.

[0270]

[0271] (Water absorption rate of the adhesive sheet)

[0272] The water absorption rate of the adhesive sheet formed from the adhesive composition was evaluated by the above method. An IGA-sorp manufactured by Hiden was used as the TGA device, and the measurement mode was set to the sequence mode. In addition, the weight of the test piece was set to 20 mg. The water absorption rate of the adhesive sheet formed from the adhesive composition B1 was 2.23%.

[0273] [Image display panel]

[0274] Image display panels Z1 to Z8 were produced using the optical laminate and the conductive paste. The following three types (Y1 to Y3) of conductive pastes were prepared.​

[0275] · Conductive paste Y1: ELEPASTE NP-1 made by Taiyo Ink, mainly containing silver as the conductive component, and the content rate of the conductive component is 57%

[0276] · Conductive paste Y2: ELEPASTE AF4820 made by Taiyo Ink, mainly containing silver as the conductive component, and the content rate of the conductive component is 69%

[0277] · Conductive paste Y3: TB3331D made by Threebond, mainly containing nickel as the conductive component, and the content rate of the conductive component is 46%

[0278] (Water contact angle on the surface of the conductive paste)

[0279] Using a contact angle meter (Dropmaster made by Kyowa Interface Science Co., Ltd.), the water contact angles on the surfaces of conductive pastes Y1 to Y3 were evaluated by the above method. An alkali-free glass was used for the glass sheet. The conductive paste was coated on the surface of the glass sheet, and the formed coating film was dried at 100 °C for 5 minutes to form a cured layer of the conductive paste (thickness: 100 μm). The water contact angles on the surfaces of conductive pastes Y1 to Y3 are shown in Table 6 below.

[0280]

[0281] (Fabrication of the image display panel)

[0282] Image display panels Z1 to Z8 were fabricated as described below. The release liner was peeled off from the optical laminate and bonded via the exposed adhesive sheet to the surface on the visible side of a separately prepared in-cell liquid crystal cell. Next, the conductive paste was coated across one long side on the side surface of the optical laminate and cured to form a conduction structure (thickness: 100 μm). The formed conduction structure was in contact with the side surfaces of the adhesive sheet and the polarizing film. The formed conduction structure was connected to an external ground electrode. Further, the lead wiring around the transparent electrode pattern inside the in-cell liquid crystal cell was connected to the controller IC. Thus, an image display panel (liquid crystal panel) with a touch sensing function was fabricated.

[0283] <Humid heat test A>

[0284] For the produced image display panels Z1 to Z8, a damp heat test A at a temperature of 85°C, a relative humidity of 85%, and a test time of 240 hours was carried out using a thermo-hygrostat. For the image display panels Z1 to Z8 after the damp heat test A, the maximum precipitation distance B of the iodine-containing precipitate was evaluated. The evaluation of the maximum precipitation distance B was carried out by the above method. The evaluation of the maximum precipitation distance B used an optical microscope (magnification: 50 times), and the observation was carried out in a range of at least 10 mm in the direction of the side surface of the optically laminated body having a conduction structure formed thereon. In addition, the fact that the precipitate contains iodine was separately confirmed by EDX.

[0285] <Examples 1 to 6, Comparative Examples 1 and 2>

[0286] For the image display panels Z1 to Z8 of Examples 1 to 6 and Comparative Examples 1 and 2, the combinations of the optically laminated body and the conductive paste, and the evaluation results of the maximum precipitation distance B are shown in Table 7 below. In addition, for the image display panels Z1, Z4, and Z6 of Example 1, Example 4, and Example 6, the observation images obtained for evaluating the maximum precipitation distance B after the damp heat test A are respectively shown in Figures 10 - 12 .

[0287]

[0288] Industrial Applicability

[0289] The kit of the optically laminated body and the conductive paste of the present invention is suitable for manufacturing an image display panel having excellent environmental resistance with a conduction structure formed on the side surface of the optically laminated body.

Claims

1. A kit for an image display panel, comprising: an optical laminate including a polarizer containing iodine, and a conductive paste, Among them, when performing a damp heat test on the optical laminate having a cured layer of the conductive paste formed on a side surface at a temperature of 85°C, a relative humidity of 85%, and a test time of 240 hours, and evaluating iodine-containing precipitates in the optical laminate after the damp heat test, a maximum precipitation distance of the precipitates in a direction perpendicular to the side surface from the side surface on which the cured layer is formed is 700 μm or less.

2. The kit according to claim 1, wherein the maximum precipitation distance is 500 μm or less.

3. The kit according to claim 1, wherein the precipitates contain a compound of iodine and a conductive component, and the conductive component is a conductive component contained in the conductive paste.

4. The kit according to claim 1, wherein the concentration of iodine in the polarizer is 5% by weight or less.

5. The kit according to claim 1, wherein the optical laminate further includes an adhesive sheet.

6. The kit according to claim 5, wherein the water absorption rate of the adhesive sheet is 1.5% by weight or more.

7. An image display panel, comprising an image forming layer and an optical laminate disposed on a visible side of the image forming layer, and having a conduction structure on a side surface of the optical laminate, the optical laminate includes a polarizer containing iodine, the conduction structure includes a cured layer of a conductive paste, when performing a damp heat test at a temperature of 85°C, a relative humidity of 85%, and a test time of 240 hours, and evaluating iodine-containing precipitates in the optical laminate after the damp heat test, a maximum precipitation distance of the precipitates in a direction perpendicular to the side surface from the side surface on which the conduction structure is formed is 700 μm or less.

8. The image display panel according to claim 7, wherein the image forming layer is an in-cell type image display unit.

9. An image display device, comprising the image display panel according to claim 7 or 8.

Images