Image display device manufacturing method and manufacturing method of image display device with front transparent member

Abstract

To provide an image display device manufacturing method, in which a long inhibitable duration of polyene formation of polyvinyl alcohol that the image display device possesses is secured.SOLUTION: The image display device manufacturing method includes a step for heating a laminate in which a resin film 40 with a first adhesive layer attached, a polarizing plate 30, a second adhesive layer 50, and an image display cell 60 are laminated in order. The resin film 40 with a first adhesive layer attached includes a resin film 42 and a first adhesive layer 41 that are laminated directly adjoining each other. A moisture permeability rate (1) of the resin film 40 with a first adhesive layer attached is 5 g / (m2 x 24 hours) to 20 g / (m2 x 24 hours) inclusive, and a moisture permeable rate (2) is 10 g / (m2 x 24 hours) or greater. The first adhesive layer 41 side of the resin film 40 with first adhesive layer attached that constitutes the laminate is laminated on the polarizing plate 30 side.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a method for manufacturing an image display device including a polarizing plate having a polarizer made of a polyvinyl alcohol-based resin film, and a method for manufacturing an image display device with a front transparent member.

Background Art

[0002] Image display devices such as liquid crystal display devices and organic EL display devices are also used as in-vehicle image display devices such as car navigation devices and rear monitors, and their applications are expanding. Along with the expansion of the applications of image display devices, polarizing plates including polarizers made of polyvinyl alcohol-based resin films, which are a part of the image display devices, are required to have higher durability in more severe environments (for example, high-temperature environments) than conventionally required.

[0003] As an in-vehicle image display device, an image display cell is bonded to one surface of a polarizing plate via an adhesive layer or an adhesive agent layer, and a front transparent member (such as a transparent resin plate, glass, or touch panel) on the viewing side is bonded to the other surface of the polarizing plate via an adhesive layer or an adhesive agent layer. An image display device (image display device with a front transparent member) having a laminated structure is used. In order to improve the durability of such an image display device with a front transparent member, for example, Patent Document 1 describes heating (aging) a laminate having a configuration of an adhesive layer, a polarizing plate, and an adhesive layer image display cell before bonding the front transparent member.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the invention described in Patent Document 1, even when an image display device with a front transparent member obtained by laminating a front transparent member on a laminate after heat treatment (aging) is exposed to a high-temperature environment, polyene formation of the polyvinyl alcohol-based resin forming the polarizer, which is a component member of the image display device with a front transparent member, is suppressed, and a decrease in its transmittance is suppressed. However, when the time from the heat treatment to the lamination of the front transparent member is long, when the image display device with a front transparent member is exposed to a high-temperature environment, the effect of suppressing polyene formation of the polyvinyl alcohol-based resin forming the polarizer is not exhibited, and the effect of suppressing the decrease in its transmittance is also not exhibited, which the present inventors have found. Also, when the time until the front transparent member is laminated is short, the productivity of the image display device with a front transparent member, such as having to perform the heat treatment many times, is significantly reduced.

[0006] In view of the above circumstances, an object of the present invention is to provide a method for manufacturing an image display device capable of lengthening the time from the heat treatment to the lamination of the front transparent member. In other words, an object is to provide a method for manufacturing an image display device with a front transparent member having high productivity.

Means for Solving the Problems

[0007] [Invention 1] A method for manufacturing an image display device in which a resin film with a first adhesive layer, a polarizing plate having a polarizer made of a polyvinyl alcohol-based resin film, a second adhesive layer, and an image display cell are laminated in this order, including a step of heating a laminate in which the resin film with the first adhesive layer, the polarizing plate, the second adhesive layer, and the image display cell are laminated in order, in the resin film with the first adhesive layer, the resin film and the first adhesive layer are directly laminated in contact with each other, the water vapor transmission rate (1) of the resin film with the first adhesive layer, obtained by the following formula (A), is 5 g / (m 2 ·24 hours) or more and 20 g / (m 2 ·24 hours) or less, The water vapor transmission rate (2) of the resin film with the first adhesive layer, which is obtained by the following formula (B), is 10 g / (m 2 ·24 hours) or more, The method for manufacturing an image display device, wherein in the laminate, the side of the first adhesive layer in the resin film with the first adhesive layer is laminated on the polarizing plate side.

[0008] (Mass of the resin film with the first adhesive layer at the 48-hour time point - Mass of the resin film with the first adhesive layer at the 24-hour time point) / (m 2 ·24 hours) Formula (A) (Mass of the resin film with the first adhesive layer at the 72-hour time point - Mass of the resin film with the first adhesive layer at the 48-hour time point) / (m 2 ·24 hours) Formula (B) (In formulas (A) and (B), the mass of the resin film with the first adhesive layer at the 24-hour time point refers to the mass per unit area when the resin film with the first adhesive layer processed to a moisture permeation area of 28.26 cm 2 is set in a moisture permeation cup containing about 45 g of calcium chloride, placed in a constant temperature machine at a temperature of 40°C and a relative humidity of 90%, and allowed to stand for 24 hours. The mass of the resin film with the first adhesive layer at the 48-hour time point refers to the mass per unit area when the resin film with the first adhesive layer processed to a moisture permeation area of 28.26 cm 2 is set in a moisture permeation cup containing about 45 g of calcium chloride, placed in a constant temperature machine at a temperature of 40°C and a relative humidity of 90%, and allowed to stand for 48 hours. The mass of the resin film with the first adhesive layer at the 72-hour time point refers to the mass per unit area when the resin film with the first adhesive layer processed to a moisture permeation area of 28.26 cm 2 is set in a moisture permeation cup containing about 45 g of calcium chloride, placed in a constant temperature machine at a temperature of 40°C and a relative humidity of 90%, and allowed to stand for 72 hours.) [Invention 2] The water vapor transmission rate (2) of the resin film with the first adhesive layer is 40 g / (m 2· The manufacturing method of the image display device according to [Invention 1], which is below 24 hours.

[0009] [Invention 3] The water vapor transmission rate (1) of the resin film with the first adhesive layer is 5 g / (m 2 · 24 hours) or more and 15 g / (m 2 · 24 hours) or less, The water vapor transmission rate (2) of the resin film with the first adhesive layer is 10 g / (m 2 · 24 hours) or more and 25 g / (m 2 · 24 hours) or less, the manufacturing method of the image display device according to [Invention 1].

[0010] [Invention 4] The water vapor transmission rate (2) of the resin film with the first adhesive layer is greater than the water vapor transmission rate (1) of the resin film with the first adhesive layer, which is characterized in that the manufacturing method of the image display device according to any one of [Invention 1] to [Invention 3].

[0011] [Invention 5] The polarizing plate has the polarizer and the protective film, and the protective film is laminated via an adhesive layer on the surface of the polarizer on the side of the first adhesive layer, The moisture permeability of the protective film under the environment of 40°C temperature and 90% relative humidity is 1000 (g / m 2 · 24 hours) or less, the manufacturing method of the image display device according to any one of [Invention 1] to [Invention 4].

[0012] [Invention 6] The manufacturing method of the image display device with a front transparent member, which includes the step of peeling the resin film from the image display device obtained by the manufacturing method of the image display device according to any one of [Invention 1] to [Invention 5] and bonding the front transparent member onto the first adhesive layer.

Advantages of the Invention

[0013] The present invention can extend the time from manufacturing an image display device to manufacturing an image display device with a front transparent member, and can improve the productivity of the image display device with a front transparent member.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0015] Hereinafter, a method for manufacturing the image display device of the present invention will be described. FIG. 1 shows an image display device 10 with a front transparent member. The image display device 10 with a front transparent member can be manufactured from the image display device 20 shown in FIG. 2. The image display device 10 with a front transparent member and a method for manufacturing the image display device with a front transparent member will be described later.

[0016] <Image display device> FIG. 2 shows an image display device 20 manufactured by the method for manufacturing the image display device of the present embodiment. The image display device 20 includes a resin film 40 with a first adhesive layer, a polarizing plate 30 having a polarizer 31 made of a polyvinyl alcohol-based resin film, a second adhesive layer 50, and an image display cell 60 laminated in this order.

[0017] In the resin film 40 with a first adhesive layer, the resin film 42 and the first adhesive layer 41 are directly in contact and laminated. In the image display device 20, the side of the first adhesive layer 41 in the resin film 40 with a first adhesive layer is laminated on the side of the polarizing plate 30.

[0018] Hereinafter, in the image display device 20, the side closer to the image display cell 60 is referred to as the cell side, and the side closer to the resin film 42 is referred to as the viewing side. In the present invention, in order to manufacture an image display device, when performing a heating step on a laminate in which an adhesive layer, a polarizing plate, an adhesive layer, and an image display cell are laminated in this order, a resin film 40 with a first adhesive layer is laminated, and the resin film with the first adhesive layer satisfies the water vapor transmission rate (1) and the water vapor transmission rate (2) described below. Although there are unclear parts in the detailed mechanism of the present invention, it is presumed as follows. When the laminate is heated and then left standing, the polarizing plate contained in the laminate and the adhesive layers on both sides of the polarizing plate absorb moisture from the surrounding again. If an image display device with a front transparent member is manufactured from the laminate in a moisture-absorbed state and the image display device with the front transparent member is continuously exposed to a high-temperature environment, polyene formation occurs due to dehydration of polyvinyl alcohol, and it is considered that the transmittance of the image display device with the front transparent member decreases. The present invention can efficiently reduce the amount of moisture during the laminate heating step and suppress moisture absorption even when left standing after the heating step by setting the water vapor transmission rate (1) and the water vapor transmission rate (2) described below within a specific range. Since the image display device obtained by the manufacturing method of the present invention can suppress moisture absorption, polyene formation of polyvinyl alcohol can be suppressed, and a decrease in transmittance can be suppressed, and it can have good durability. Note that the present invention does not have to be interpreted as being limited to the above mechanism.

[0019] Hereinafter, elements that constitute or can constitute the image display device 20 will be described in detail. <Polarizing plate> As shown in FIG. 3, the polarizing plate 30 has, for example, a polarizer 31 and a first protective film 33 that protects the polarizer 31.

[0020] As shown in FIG. 3 for example, the first protective film 33 is laminated on the visible side surface of the polarizer 31 of the polarizing plate 30 via an adhesive layer 32. That is, it can be said that in the image display device 20, a protective film is laminated on the surface of the polarizer 31 on the side of the first adhesive layer 41 via the adhesive layer 32. In the image display device 20 including the polarizing plate 30 in this case, the first adhesive layer 41 of the resin film 40 with the first adhesive layer is laminated on the visible side of the first protective film 33.

[0021] As shown in FIG. 3, the polarizing plate 30 may have a second protective film 34 laminated on the cell-side surface of the polarizer 31 via an adhesive layer 32. In the image display device 20 including the polarizing plate 30 in this case, a second adhesive layer 50 is laminated on the cell side of the second protective film 34. For example, the polarizing plate 30 may not include the second protective film 34. When the polarizing plate 30 does not include the second protective film 34, the cell-side surface of the polarizer 31 and the image display cell 60 are bonded via an adhesive or an adhesive. Further, the polarizing plate 30 preferably includes at least the first protective film 33 among the first protective film 33 and the second protective film 34, but may not include the first protective film 33. When the polarizing plate 30 does not include the first protective film 33, the first adhesive layer 41 is directly laminated on the viewing-side surface of the polarizer 31.

[0022] 〔Polarizer〕 The polarizer 31 is a polyvinyl alcohol-based resin film in which a dichroic dye is adsorbed and oriented. As the polyvinyl alcohol-based resin, for example, a saponified product of a polyvinyl acetate-based resin can be used. The saponification degree of the polyvinyl acetate-based resin is preferably 85 mol% or more, more preferably 90 mol% or more, and still more preferably 99 mol% or more.

[0023] As the polyvinyl acetate-based resin, for example, polyvinyl acetate which is a homopolymer of vinyl acetate, a copolymer of vinyl acetate and another monomer copolymerizable therewith, etc. can be used. Examples of other copolymerizable monomers include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and the like.

[0024] The degree of polymerization of the polyvinyl alcohol-based resin is preferably 1000 or more and 10000 or less, and more preferably 1500 or more and 5000 or less. The polyvinyl alcohol-based resin may be modified. Examples of the modified polyvinyl alcohol-based resin include polyvinyl formal, polyvinyl acetal, polyvinyl butyral, etc., which are modified with aldehydes.

[0025] Examples of the dichroic dye include iodine, water-soluble dichroic dyes, etc. The thickness of the polarizer 31 is not particularly limited, but is preferably 3 μm or more and 35 μm or less, more preferably 4 μm or more and 30 μm or less, and even more preferably 5 μm or more and 25 μm or less. By the thickness of the polarizer being 35 μm or less, the influence on the deterioration of the optical properties of the polarizer due to polyene formation of the polyvinyl alcohol-based resin in a high-temperature environment can be suppressed.

[0026] As the manufacturing method of the polarizer 31, a known method can be adopted. As the manufacturing method, for example, a swelling step, a dyeing step, a crosslinking step, a washing step, and a drying step are sequentially performed using a polyvinyl alcohol-based resin film as a raw film. The swelling step is a treatment step of swelling the raw film by immersing it in a swelling liquid. The dyeing step is a treatment step of adsorbing and orienting the dichroic dye on the film by immersing the film after the swelling step in a dyeing liquid containing the dichroic dye. The crosslinking step is a treatment step of performing a crosslinking treatment by bringing a crosslinking liquid into contact with the film. Between each step, that is, before, after, or during any one or more treatment steps, a uniaxial stretching treatment as a stretching step can be performed.

[0027] 〔Protective Film〕 The first protective film 33 is not particularly limited, and various transparent protective films that can be used for a polarizing plate can be adopted. As the material constituting the protective film, for example, a thermoplastic resin excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy, etc. is used. Examples of the above thermoplastic resin include cellulose ester resins such as triacetyl cellulose, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, polyether sulfone resins, polysulfone resins, polycarbonate resins, polyamide resins such as nylon and aromatic polyamide, polyimide resins, polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymer, (meth)acrylic resins, cyclic polyolefin resins (norbornene resins) having a cyclic or norbornene structure, polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof. Further, the protective film can use a cured layer formed from a thermosetting resin or an ultraviolet curable resin such as (meth)acrylic, urethane, acrylic urethane, epoxy, or silicone. Among these, cellulose ester resins, polycarbonate resins, (meth)acrylic resins, cyclic polyolefin resins, and polyester resins are preferred.

[0028] On the surface of the protective film where the polarizer is not laminated, functional layers such as a hard coat layer, an antireflection layer, an anti-sticking layer, a diffusion layer, or an antiglare layer can be provided. Note that the functional layers such as the hard coat layer, the antireflection layer, the anti-sticking layer, the diffusion layer, and the antiglare layer can be provided on the protective film itself, or can be provided separately as a separate body from the protective film.

[0029] Of the surface of the protective film where the polarizer is laminated and the surface of the polarizer where the protective film is laminated, surface treatment may be performed on either one or both surfaces. Examples of the surface treatment include corona treatment, plasma treatment, primer treatment, saponification treatment, etc.

[0030] The thickness of the first protective film 33 is not particularly limited, but for example, it is 1 μm or more and 500 μm or less, preferably 1 μm or more and 300 μm or less, more preferably 5 μm or more and 300 μm or less, and even more preferably 5 μm or more and 100 μm or less.

[0031] The first protective film 33 preferably has a moisture permeability of 1000 (g / m 2 ·24 h) or less under the environment of a temperature of 40 °C and a relative humidity of 90%. The above moisture permeability is preferably 200 (g / m 2 ·24 h) or more.

[0032] The above moisture permeability is more preferably 200 (g / m 2 ·24 h) or more and 900 (g / m 2 ·24 h) or less, even more preferably 200 (g / m 2 ·24 h) or more and 600 (g / m 2 ·24 h) or less, and still even more preferably 200 (g / m 2 ·24 h) or more and 300 (g / m 2 ·24 h) or less.

[0033] The measurement of the moisture permeability can be carried out in accordance with the moisture permeability test (cup method) of JIS Z0208. When the moisture permeability of the first protective film 33 is 1000 (g / m 2 ·24 h) or less, the transfer of moisture to the polarizer 31 can be suppressed, and the moisture absorption of the polarizer after the heat treatment can be easily suppressed. As a result, it is presumed that the polyene formation is less likely to proceed. Therefore, the moisture permeability of the first protective film 33 is preferably 1000 (g / m 2 ·24 h) or less.

[0034] Similar to the first protective film 33, the second protective film 34 can be appropriately selected from the above various protective films for use. The second protective film 34 may use a film of a type different from that of the first protective film 33, or may use a film of the same type as the first protective film 33.

[0035] The second protective film 34 preferably has a moisture permeability of 1000 (g / m 2 ·24 hours) or less in an environment of 40°C and 90% relative humidity. When the moisture permeability of the second protective film 34 is 1000 (g / m 2 ·24 hours) or less, it is possible to suppress the migration of moisture from the second adhesive layer 50 side to the polarizer 31, and it is also easy to suppress the moisture absorption of the polarizer after the heat treatment. As a result, since it is presumed that polyene formation hardly progresses, it is preferable that the moisture permeability of the second protective film 34 is 1000 (g / m 2 ·24 hours) or less.

[0036] 〔Adhesive layer〕 As the adhesive for forming the adhesive layer 32, various adhesives that can be used for a polarizing plate can be applied. For example, isocyanate-based adhesives, polyvinyl alcohol-based adhesives, gelatin-based adhesives, vinyl-based latexes, aqueous polyesters, and the like can be mentioned. These adhesives are usually used as adhesives composed of an aqueous solution (aqueous adhesives) and contain a solid content of 0.5 to 60% by weight. Among these, polyvinyl alcohol-based adhesives are preferable, and polyvinyl alcohol-based adhesives containing an acetoacetyl group are more preferable.

[0037] The above aqueous adhesive may contain a crosslinking agent. As the crosslinking agent, a compound having at least two functional groups reactive with components such as polymers constituting the adhesive in one molecule is usually used. For example, alkylenediamines; isocyanates; epoxies; aldehydes; amino-formaldehydes such as methylol urea and methylol melamine can be mentioned. The blending amount of the crosslinking agent in the adhesive is usually about 10 to 60 parts by weight with respect to 100 parts by weight of components such as polymers constituting the adhesive.

[0038] Examples of the adhesive include active energy ray-curable adhesives such as ultraviolet curable adhesives and electron beam curable adhesives in addition to the water-based adhesive. Examples of the active energy ray-curable adhesive include (meth)acrylate-based adhesives. Examples of the curable components in the (meth)acrylate-based adhesive include compounds having a (meth)acryloyl group and compounds having a vinyl group. Examples of the compounds having a (meth)acryloyl group include alkyl (meth)acrylates such as linear alkyl (meth)acrylates having 1 to 20 carbon atoms, alicyclic alkyl (meth)acrylates, and polycyclic alkyl (meth)acrylates; hydroxyl group-containing (meth)acrylates; epoxy group-containing (meth)acrylates such as glycidyl (meth)acrylate. The (meth)acrylate-based adhesive may contain nitrogen-containing monomers such as hydroxyethyl (meth)acrylamide, N-methylol (meth)acrylamide, N-methoxymethyl (meth)acrylamide, N-ethoxymethyl (meth)acrylamide, (meth)acrylamide, and (meth)acryloylmorpholine. The (meth)acrylate-based adhesive may contain polyfunctional monomers such as tripropylene glycol diacrylate, 1,9-nonanediol diacrylate, tricyclodecane dimethanol diacrylate, cyclic trimethylolpropane formal acrylate, dioxane glycol diacrylate, and EO-modified diglycerin tetraacrylate as crosslinking components. Also, compounds having an epoxy group or an oxetanyl group can be used as cationic polymerization curable adhesives. The compound having an epoxy group is not particularly limited as long as it has at least two epoxy groups in the molecule, and various generally known curable epoxy compounds can be used.

[0039] The above-mentioned adhesive may contain appropriate additives as required. Examples of the additives include coupling agents such as silane coupling agents and titanium coupling agents, adhesion promoters such as ethylene oxide, ultraviolet absorbers, anti-degradants, dyes, processing aids, ion trap agents, antioxidants, tackifiers, fillers, plasticizers, leveling agents, foam suppressants, antistatic agents, heat stabilizers, hydrolysis-resistant stabilizers, and the like.

[0040] The application of the above-mentioned adhesive may be performed on either the protective film side or the polarizer side, or on both sides. After lamination, a drying process is carried out to form an adhesive layer composed of a coating-dried layer. After the drying process, ultraviolet rays or electron beams can be irradiated as required.

[0041] The thickness of the adhesive layer 32 is not particularly limited. For example, when using an aqueous adhesive or the like, it is preferably about 30 to 5000 nm, more preferably about 100 to 1000 nm. For example, when using an ultraviolet curable adhesive, an electron beam curable adhesive, or the like, it is preferably about 0.1 to 100 μm, more preferably about 0.5 to 10 μm.

[0042] <Resin Film with First Adhesive Layer> 〔Resin Film〕 Examples of the resin constituting the resin film 40 include polyolefin resins such as polyethylene-based resins and polypropylene-based resins; cyclic polyolefin resins; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polycarbonate resins; (meth)acrylic resins, and the like. Among these, polyester resins such as polyethylene terephthalate are preferred. The resin film may have a single-layer structure or may have a multilayer structure of two or more layers. The resin film may be a film subjected to stretching treatment such as uniaxial stretching or biaxial stretching.

[0043] The resin film 40 may be provided with a release layer by treating its surface with a release agent. Examples of the release agent include silicone-based release agents. In this case, the resin film 40 with the first adhesive layer is configured by directly laminating the first adhesive layer 41 on the surface of the resin film 40 that has been release-treated.

[0044] 〔First Adhesive Layer〕 As the adhesive for forming the first adhesive layer 41, various adhesives that can be used in an image display device can be applied. For example, rubber-based adhesives, acrylic-based adhesives, silicone-based adhesives, urethane-based adhesives, vinyl alkyl ether-based adhesives, polyvinyl alcohol-based adhesives, polyvinyl pyrrolidone-based adhesives, polyacrylamide-based adhesives, cellulose-based adhesives, etc. can be mentioned. Among these, acrylic-based adhesives are preferred. The above acrylic-based adhesive contains an acrylic polymer as a base polymer, and for example, the acrylic-based adhesive described in JP-A-2017-75998 can be exemplified.

[0045] The acrylic polymer in the above acrylic-based adhesive has a monomer unit of (meth)acrylic acid alkyl ester as a main skeleton. As the (meth)acrylic acid alkyl ester, a (meth)acrylic acid alkyl ester having 1 to 20 carbon atoms in the alkyl group is preferably used, and the content of the (meth)acrylic acid alkyl ester is preferably 40% by weight or more, more preferably 60% by weight or more, based on the total amount of the monomer components constituting the base polymer. Also, from the viewpoint of adjusting the adhesiveness of the adhesive, monomer units such as nitrogen-containing monomer units and hydroxy group-containing monomers may be included. Further, in order to form a crosslinked structure in the adhesive layer, a crosslinking agent may be used. Examples of the crosslinking agent include commonly used ones such as isocyanate-based crosslinking agents, epoxy-based crosslinking agents, oxazoline-based crosslinking agents, aziridine-based crosslinking agents, carbodiimide-based crosslinking agents, and metal chelate-based crosslinking agents. The amount of the crosslinking agent used is usually 10 parts by weight or less, preferably 5 parts by weight or less, based on 100 parts by weight of the base polymer.

[0046] From the perspective of being able to adjust the adhesive force, the above-mentioned adhesive may be added with a silane coupling agent; tackifiers such as terpene-based tackifiers, styrene-based tackifiers, phenol-based tackifiers, rosin-based tackifiers, and epoxy-based tackifiers. Further, from the perspective of improving light resistance, an ultraviolet absorber may be added. In addition to the components exemplified above, additives such as plasticizers, softening agents, deterioration inhibitors, fillers, colorants, antioxidants, surfactants, and antistatic agents can be used within a range that does not impair the properties of the adhesive.

[0047] As a method for forming the adhesive layer, for example, a method of applying the above-mentioned adhesive to a separator or the like that has been subjected to a release treatment, drying to form an adhesive layer, and then transferring it to a polarizing film or the like, or a method of applying the above-mentioned adhesive to a polarizing film or the like and drying to form an adhesive layer can be exemplified.

[0048] 〔Water vapor transmission rate〕 The resin film 40 with the first adhesive layer has a water vapor transmission rate within a specific range. Specifically, for the resin film 40 with the first adhesive layer, the water vapor transmission rate (1) is 5 g / (m 2 ·24 h) or more and 20 g / (m 2 ·24 h) or less. Further, for the resin film 40 with the first adhesive layer, the water vapor transmission rate (2) is 10 g / (m 2 ·24 h) or more.

[0049] The above water vapor transmission rate (1) can be obtained from the following formula (A). The above water vapor transmission rate (2) can be obtained from the following formula (B). (Mass of the resin film with the first adhesive layer at the 48-hour time point - Mass of the resin film with the first adhesive layer at the 24-hour time point) / (m 2 ·24 h) (A) (Mass of the resin film with the first adhesive layer at the 72-hour time point - Mass of the resin film with the first adhesive layer at the 48-hour time point) / (m 2 ·24 h) (B) In the above formulas (A) and (B), the "mass of the resin film with the first pressure-sensitive adhesive layer at the 24-hour time point" represents the following value. The "mass of the resin film with the first pressure-sensitive adhesive layer at the 24-hour time point" complies with the water vapor permeability test (cup method) of JIS Z0208, and the resin film with the first pressure-sensitive adhesive layer processed to a water vapor permeation area of 28.26 cm 2 is set in a water vapor permeation cup containing about 45 g of calcium chloride, and is the mass per unit area when left standing in a constant temperature machine at a temperature of 40 °C and a relative humidity of 90% for 24 hours.

[0050] In the above formula (A), the "mass of the resin film with the first pressure-sensitive adhesive layer at the 48-hour time point" represents the following value. The "mass of the resin film with the first pressure-sensitive adhesive layer at the 48-hour time point" complies with the water vapor permeability test (cup method) of JIS Z0208, and the resin film with the first pressure-sensitive adhesive layer processed to a water vapor permeation area of 28.26 cm 2 is set in a water vapor permeation cup containing about 45 g of calcium chloride, and is the mass per unit area when left standing in a constant temperature machine at a temperature of 40 °C and a relative humidity of 90% for 48 hours.

[0051] In the above formula (B), the "mass of the resin film with the first pressure-sensitive adhesive layer at the 72-hour time point" represents the following value. The "mass of the resin film with the first pressure-sensitive adhesive layer at the 72-hour time point" complies with the water vapor permeability test (cup method) of JIS Z0208, and the resin film with the first pressure-sensitive adhesive layer processed to a water vapor permeation area of 28.26 cm 2 is set in a water vapor permeation cup containing about 45 g of calcium chloride, and is the mass per unit area when left standing in a constant temperature machine at a temperature of 40 °C and a relative humidity of 90% for 72 hours.

[0052] Since the water vapor transmission rate of the resin film 40 with the first pressure-sensitive adhesive layer is within the above specific range, it is possible to facilitate the removal of moisture from the polarizer 31 in the heating process described later, and to suppress the absorption of moisture by the polarizer 31 after the heating process.

[0053] The water vapor transmission rate (1) in the resin film 40 with the first pressure-sensitive adhesive layer is 5 g / (m 2 ·24 h) or more and 15 g / (m 2· It is preferably below 5 g / (m·24 hours), and more preferably 2 · It is above 5 g / (m·24 hours) and below 11 g / (m·24 hours). 2 · It is more preferably below 5 g / (m·24 hours), and 2 · It is above 5 g / (m·24 hours) and below 7 g / (m·24 hours). 2 · It is even more preferably below 5 g / (m·24 hours).

[0054] The water permeation rate (2) in the resin film 40 with the first adhesive layer is such that the water permeation rate (2) is preferably from 10 g / (m 2 ·24 hours) to 40 g / (m·24 hours), more preferably from 10 g / (m 2 ·24 hours) to 25 g / (m·24 hours), even more preferably from 10 g / (m 2 ·24 hours) to 15 g / (m·24 hours), and most preferably from 10 g / (m 2 ·24 hours) to 15 g / (m·24 hours). 2 ·24 hours) to 15 g / (m·24 hours), and 2 · It is even more preferably below 15 g / (m·24 hours).

[0055] The water permeation rate (1) and the water permeation rate (2) in the resin film 40 with the first adhesive layer are such that the water permeation rate (1) is from 5 g / (m 2 ·24 hours) to 15 g / (m·24 hours), and the water permeation rate (2) is from 10 g / (m 2 ·24 hours) to 25 g / (m·24 hours), and preferably 2 ·24 hours) to 25 g / (m·24 hours). 2 · It is preferably in the above numerical range within the range where the water permeation rate (2) is equal to or higher than the water permeation rate (1), and more preferably in the above numerical range within the range where the water permeation rate (2) is greater than the water permeation rate (1).

[0056] The water permeation rate (1) and the water permeation rate (2) in the resin film 40 with the first adhesive layer preferably satisfy the above numerical range within the range where the water permeation rate (2) is equal to or higher than the water permeation rate (1), and more preferably satisfy the above numerical range within the range where the water permeation rate (2) is greater than the water permeation rate (1).

[0057] The water vapor transmission rate (1) and the water vapor transmission rate (2) in the resin film 40 with the first adhesive layer can be adjusted, for example, by the type of the resin film 42, the thickness of the resin film 42, the type of the first adhesive layer 41, the thickness of the first adhesive layer 41, and the moisture permeability of the first adhesive layer 41. If the water vapor transmission rate (1) and the water vapor transmission rate (2) in the resin film 40 with the first adhesive layer are within the above-specified ranges, the type of the resin film 42, the thickness of the resin film 42, the type of the first adhesive layer 41, the thickness of the first adhesive layer 41, and the moisture permeability of the first adhesive layer 41 are not particularly limited.

[0058] The thickness of the resin film 42 is, for example, 30 μm or more and 160 μm or less, preferably 30 μm or more and 120 μm or less, more preferably 30 μm or more and 80 μm or less, and still more preferably 50 μm or more and 80 μm or less.

[0059] The thickness of the first adhesive layer 41 is, for example, 100 μm or more and 900 μm or less, preferably 100 μm or more and 700 μm or less, more preferably 100 μm or more and 500 μm or less, and still more preferably 125 μm or more and 500 μm or less.

[0060] The moisture permeability of the first adhesive layer 41 is, for example, 100 g / (m 2 ·24 h) or more and 1000 g / (m 2 ·24 h) or less, preferably 100 g / (m 2 ·24 h) or more and 800 g / (m 2 ·24 h) or less, more preferably 100 g / (m 2 ·24 h) or more and 600 g / (m 2 ·24 h) or less, and still more preferably 200 g / (m 2 ·24 h) or more and 600 g / (m 2 ·24 h) or less.

[0061] <The second adhesive layer> As the adhesive for forming the second adhesive layer 50, similar to the first adhesive layer 41, it can be appropriately selected and used from the above-mentioned various adhesives. The second adhesive layer 50 may use an adhesive of a different type from the first adhesive layer 41, or may use the same type of adhesive as the first adhesive layer 41. The thickness of the second adhesive layer 50 is not particularly limited, and is, for example, about 1 to 100 μm, preferably about 2 to 50 μm.

[0062] <Image display cell> Examples of the image display cell 60 include a liquid crystal cell, an organic EL cell, and the like. As the liquid crystal cell, for example, any of a reflective liquid crystal cell that uses external light, a transmissive liquid crystal cell that uses light from a light source such as a backlight, and a transflective liquid crystal cell that uses both external light and light from a light source may be used. When the liquid crystal cell uses light from a light source, a polarizing plate is also disposed on the side opposite to the viewing side of the image display cell (liquid crystal cell) in the image display device (liquid crystal display device), and a light source is further disposed. It is preferable that the polarizing plate on the light source side and the liquid crystal cell are bonded via an appropriate adhesive layer. As the driving method of the liquid crystal cell, for example, any type such as VA mode, IPS mode, TN mode, STN mode, or bend alignment (π type) can be used.

[0063] As the organic EL cell, for example, a structure in which a transparent electrode, an organic light-emitting layer, and a metal electrode are sequentially laminated on a transparent substrate to form a light emitter (organic electroluminescence light emitter) is preferably used. The organic light-emitting layer is a laminate of various organic thin films. For example, a laminate of a hole injection layer made of a triphenylamine derivative or the like and a light-emitting layer made of a fluorescent organic solid such as anthracene, a laminate of these light-emitting layers and an electron injection layer made of a perylene derivative or the like, or a laminate of a hole injection layer, a light-emitting layer, and an electron injection layer, etc., various layer configurations can be adopted.

[0064] <Method for manufacturing an image display device> The method for manufacturing an image display device includes a lamination step of obtaining a laminate in which a resin film 40 with a first adhesive layer, a polarizing plate 30, a second adhesive layer 50, and an image display cell 60 are laminated in this order.

[0065] The method for manufacturing an image display device includes a heating step of heating a laminate in which a resin film 40 with a first adhesive layer, a polarizing plate 30, a second adhesive layer 50, and an image display cell 60 are laminated in this order. The method for manufacturing an image display device may further include other steps than the steps described in the above embodiment. In the method for manufacturing an image display device, it is preferable that the heating step is the last step.

[0066] By performing the heating step, it is possible to reduce the moisture contained in the polarizer 31, the first adhesive layer 41, the second adhesive layer 50, the first protective film 33, the second protective film 34, and the like. By heating the laminate, while reducing the moisture contained in each member (particularly the polarizer 31) constituting the laminate during heating, it is possible to suppress the transfer of moisture to each member (particularly the polarizer 31) constituting the laminate after the heating step.

[0067] The heating step is not particularly limited, but for example, it can be performed by putting the laminate into a hot air oven. The heating temperature in the heating step of heating the laminate is not particularly limited as long as it can reduce the moisture contained in each member (particularly the polarizer 31) constituting the laminate. For example, it is 80°C or higher and 100°C or lower, preferably 80°C or higher and 95°C or lower, and more preferably 85°C or higher and 95°C or lower.

[0068] The heating time in the heating step of heating the laminate is not particularly limited as long as it can reduce the moisture contained in each member (particularly the polarizer 31) constituting the laminate. For example, it is 30 minutes or longer and 5 hours or shorter, preferably 1 hour or longer and 5 hours or shorter, and more preferably 1 hour or longer and 3 hours or shorter. Note that the higher the heating temperature, the shorter the heating time can be.

[0069] As the next step performed using the image display device 20, for example, there is a step of bonding the front transparent member 70. The image display device 10 with a front transparent member shown in FIG. 1 can be manufactured by peeling the resin film 42 from the image display device 20 and bonding the front transparent member 70 to the first adhesive layer 41 after peeling. Note that the image display device 20 may be left standing at room temperature (25° C.) until the resin film 42 is peeled from the image display device 20. By using the manufacturing method of the present invention, even if the period until the image display device 10 with a front transparent member is manufactured from the image display device 20 becomes long, the obtained image display device 10 with a front transparent member can have good durability even when exposed to a high-temperature environment.

[0070] Examples of the front transparent member 70 include a front transparent plate (window layer) and a touch panel. As the front transparent plate, a transparent plate having appropriate mechanical strength and thickness is used. Examples of such a transparent plate include a transparent resin plate such as an acrylic resin or a polycarbonate resin, or a glass plate. As the touch panel, various touch panels such as a resistive film method, a capacitance method, an optical method, and an ultrasonic method, and a glass plate or a transparent resin plate having a touch sensor function are used.

[0071] <Use of the image display device or the image display device with a front transparent member> Examples of the use of the image display device 20 or the image display device 10 with a front transparent member include applications for mobile devices such as televisions, personal computers, mobile phones, and tablet terminals, and in-vehicle applications. Specific examples of in-vehicle applications include car navigation devices, speedometers, touch panels for air conditioners, rear monitors, and rear monitors.

[0072] <Effect of this embodiment> Regarding the image display device 20 obtained by the manufacturing method of the image display device according to this embodiment, the time until the polyvinyl alcohol of the polarizer 31 is polyene-ized can be lengthened. For this reason, after the heating step, that is, after manufacturing the image display device 20, it is possible to suppress the progress of polyene-ization due to the polarizer or the like absorbing water again before performing the subsequent steps.

[0073] Furthermore, the image display device 20 is excellent in high-temperature durability. For this reason, the image display device 10 with a front transparent member manufactured by the manufacturing method of the image display device according to this embodiment can be suitably used also for applications that may be exposed to a high-temperature environment for a long time. For example, an in-vehicle image display device may be exposed to a high-temperature environment for a long time. That is, the image display device 10 with a front transparent member can be suitably used for in-vehicle applications.

Example

[0074] The manufacturing method of the image display device and the manufacturing method of the image display device with a front transparent member will be described in more detail based on the examples described below. Note that the manufacturing method of the image display device and the manufacturing method of the image display device with a front transparent member are not limited to the configurations described in the example section.

[0075] <Measurement of water vapor transmission rate of the protective film> The water vapor transmission rate of the protective film used in the manufacture of the polarizing plate was measured at a temperature of 40°C and a relative humidity of 90% in accordance with the water vapor transmission rate test (cup method) of JIS Z0208.

[0076] <Measurement of water vapor transmission rate of the first adhesive layer> The first adhesive layer used in each production example was measured at a temperature of 40°C and a relative humidity of 90% in accordance with the water vapor transmission rate test (cup method) of JIS Z0208.

[0077] <Measurement of water permeation rate of the resin film with the first adhesive layer> In accordance with the water vapor transmission rate test (cup method) of JIS Z0208, the water vapor permeation area is 28.26 cm 2The resin film with the first adhesive layer processed as such was set in a moisture permeation cup containing approximately 45 g of calcium chloride, and left standing for 24 hours in a thermostatic chamber at a temperature of 40°C and a relative humidity of 90%. The mass per unit area at this time was defined as the "mass of the resin film with the first adhesive layer at the 24-hour mark". Also, the mass per unit area when left standing for 48 hours in a thermostatic chamber at a temperature of 40°C and a relative humidity of 90% was defined as the "mass of the resin film with the first adhesive layer at the 48-hour mark". Furthermore, the mass per unit area when left standing for 72 hours in a thermostatic chamber at a temperature of 40°C and a relative humidity of 90% was defined as the "mass of the resin film with the first adhesive layer at the 72-hour mark".

[0078] The moisture permeation rate (1) was obtained from the following formula (A), and the moisture permeation rate (2) was obtained from the following formula (B). (Mass of the resin film with the first adhesive layer at the 48-hour mark - Mass of the resin film with the first adhesive layer at the 24-hour mark) / (m 2 · 24 hours) (A) (Mass of the resin film with the first adhesive layer at the 72-hour mark - Mass of the resin film with the first adhesive layer at the 48-hour mark) / (m 2 · 24 hours) (B) <Resin film with the first adhesive layer> To produce a resin film with the first adhesive layer in which a resin film having a release layer and the first adhesive layer are laminated, the following resin film and the first adhesive layer were prepared.

[0079] 〔Resin film〕 · Resin film A1: A polyester-based resin film with a release layer and a thickness of 80 μm · Resin film A2: A polyester-based resin film with a release layer and a thickness of 200 μm · Resin film B1: A polyester-based resin film with a release layer and a thickness of 38 μm · Resin film B2: A polyester-based resin film with a release layer and a thickness of 75 μm 〔The first adhesive layer〕 · Adhesive layer C1: An adhesive layer with a thickness of 250 μm (product name "CEF2810" manufactured by 3M) was laminated to form an adhesive layer with a thickness of 500 μm. The water vapor transmission rate was 216 g / (m 2 · 24 hours). · Adhesive layer C2: An adhesive layer with a thickness of 250 μm (product name "CEF2810" manufactured by 3M). The water vapor transmission rate was 364 g / (m 2 · 24 hours). · Adhesive layer C3: An adhesive layer with a thickness of 125 μm (product name "CEF2805" manufactured by 3M). The water vapor transmission rate was 548 g / (m 2 · 24 hours). · Adhesive layer D: An acrylic adhesive layer with a thickness of 15 μm. The water vapor transmission rate was 2000 g / (m 2 · 24 hours) or more.

[0080] (Production Example 1: Production of a polarizer) A polyvinyl alcohol-based resin film with a thickness of 30 μm was immersed in pure water at 21.5°C for 79 seconds (swelling step), and then immersed in an aqueous solution at 23°C with a mass ratio of potassium iodide / boric acid / water of 2 / 2 / 100 and containing 1.0 mM of iodine for 151 seconds (dyeing step). Thereafter, it was immersed in an aqueous solution at 68.5°C with a mass ratio of potassium iodide / boric acid / water of 2.5 / 4 / 100 for 76 seconds (first crosslinking step). Subsequently, it was immersed in an aqueous solution at 45°C with a mass ratio of potassium iodide / boric acid / zinc chloride / water of 3 / 5.5 / 0.6 / 100 for 11 seconds (second crosslinking step, metal ion treatment step). Thereafter, it was immersed in a washing bath for washing (washing step) and dried at 38°C (drying step) to obtain a polarizer with a thickness of 12 μm in which iodine was adsorbed and oriented on the polyvinyl alcohol. The stretching was mainly carried out in the dyeing step and the first crosslinking step, and the total stretching ratio was 5.85 times. The thickness of the obtained polarizer was measured using a digital micrometer "MH-15M" manufactured by Nikon Corporation.

[0081] (Production Example 2: Preparation of an adhesive composition) 50 g of a modified polyvinyl alcohol-based resin containing an acetoacetyl group (manufactured by Mitsubishi Chemical Corporation: Gosenex Z-410) was dissolved in 950 g of pure water, heated at 90 °C for 2 hours, and then cooled to room temperature to obtain an acetoacetyl group-modified polyvinyl alcohol-based resin solution.

[0082] Maleic acid, a 40% by mass glyoxal solution, and pure water were blended into the obtained acetoacetyl group-modified polyvinyl alcohol-based resin solution so as to have the contents shown in Table 1 below, thereby preparing an adhesive composition.

[0083] [Table 1]

[0084] <Production of Polarizing Plate> The following protective films were prepared. · Protective film F1: A saponified triacetyl cellulose film with a hard coat layer (manufactured by Toppan Printing Co., Ltd., trade name "40FJCHCN-LMP", triacetyl cellulose film thickness: 40 μm, hard coat layer thickness: 7 μm). The moisture permeability was 200 g / (m 2 · 24 hours). · Protective film F2: A saponified cellulose acylate film (manufactured by Fujifilm Corporation, trade name "Fujitac ZRG40", thickness 40 μm). The moisture permeability was 900 g / (m 2 · 24 hours). · Protective film F3: A saponified triacetyl cellulose film with a hard coat layer (manufactured by Toppan Printing Co., Ltd., trade name "40FJCHCN-TC", triacetyl cellulose film thickness: 40 μm, hard coat layer thickness: 7 μm). The moisture permeability was 350 g / (m 2 · 24 hours). · Protective film F4: A saponified triacetyl cellulose film (manufactured by Fujifilm Corporation, trade name "TJ40UL", thickness 40 μm). The moisture permeability was 900 g / (m 2 · 24 hours). · Protective film F5: Saponified cellulose acetate film (trade name "FUJITAC ZRG25", thickness 25 μm, manufactured by Fujifilm Corporation). The water vapor permeability was 1200 g / (m 2 · 24 hours).

[0085] (Production Example 3: Production of Polarizing Plate (1)) On one side of the polarizer produced in Production Example 1, the surface of the protective film F1 that does not have the hard coat layer laminated thereon was laminated via the adhesive composition prepared in Production Example 2. Further, on the other side of the polarizer, the protective film F2 was laminated via the adhesive composition prepared in Production Example 2 and laminated using a roll laminator. Then, it was dried at 75 °C for 8 minutes to obtain a polarizing plate (1). Note that the adhesive layers composed of the adhesive composition had a thickness of 80 nm each after drying. The protective film F1 corresponds to the first protective film. The protective film F2 corresponds to the second protective film. Table 2 shows the configuration of the polarizing plate (1).

[0086] (Production Example 4: Production of Polarizing Plate (2)) A polarizing plate (2) was obtained in the same manner as the polarizing plate (1) except that the protective film F3 was used instead of the protective film F1. Table 2 shows the configuration of the polarizing plate (2).

[0087] (Production Example 5: Production of Polarizing Plate (3)) A polarizing plate (3) was obtained in the same manner as the polarizing plate (1) except that the protective film F4 was used instead of the protective film F1. Note that the protective film F4 was laminated to the polarizer via an adhesive layer on the triacetyl cellulose side. Table 2 shows the configuration of the polarizing plate (3).

[0088] (Production Example 6: Production of Polarizing Plate (4)) A polarizing plate (4) was obtained in the same manner as the polarizing plate (1) except that the protective film F5 was used instead of the protective film F2. Table 2 shows the configuration of the polarizing plate (4).

[0089]

Table 2

[0090] (Production Example 6: Production of Laminate (1)) A 25-μm acrylic adhesive layer was formed on the second protective film side of the polarizing plate (1), that is, on the protective film F2 side, to obtain a polarizing plate (1) with an adhesive layer. In the obtained polarizing plate (1) with an adhesive layer, it was cut into a size of 90 mm × 100 mm so that the absorption axis was parallel to the long side. A 100 mm × 100 mm non-alkali glass (Corning's "EAGLE XG") was bonded to the surface of the adhesive layer of the polarizing plate (1) with an adhesive layer to obtain a polarizing plate (1) with a glass plate.

[0091] A resin film with a first adhesive layer (resin film A1) having a thickness of 80 μm and a release layer and an adhesive layer C1 with a thickness of 500 μm was laminated on the first protective film side of the obtained polarizing plate with a glass plate, that is, on the protective film F1 side, and bonded on the adhesive layer side to produce a laminate (1).

[0092] (Production Example 7: Production of Laminate (2)) A laminate (2) was produced in the same manner as in Production Example 6, except that the 500-μm first adhesive layer (adhesive layer C1) in the resin film with a first adhesive layer was changed to a 250-μm first adhesive layer (adhesive layer C2).

[0093] (Production Example 8: Production of Laminate (3)) A laminate (3) was produced in the same manner as in Production Example 6, except that the 500-μm first adhesive layer (adhesive layer C1) in the resin film with a first adhesive layer was changed to a 125-μm first adhesive layer (adhesive layer C3).

[0094] (Production Example 9: Production of Laminate (4)) A laminate (4) was produced in the same manner as in Production Example 7, except that the polarizing plate (1) was changed to a polarizing plate (2).

[0095] (Production Example 10: Production of Laminate (5)) A laminate (5) was produced in the same manner as in Production Example 7, except that the polarizing plate (1) was changed to a polarizing plate (3).

[0096] (Production Example 11: Production of laminate (6)) A laminate (6) was produced in the same manner as in Production Example 7, except that the polarizing plate (1) was changed to a polarizing plate (4).

[0097] (Production Example 12: Production of laminate (7)) A laminate (7) was produced in the same manner as in Production Example 7, except that the resin film (resin film A1) with a thickness of 80 μm in the resin film with the first adhesive layer was changed to a polyester-based resin film (resin film A2) with a thickness of 200 μm having a release layer.

[0098] (Production Example 13: Production of laminate (8)) A laminate (8) was produced in the same manner as in Production Example 7, except that the polyester-based resin film (resin film A1) with a thickness of 80 μm having a release layer was not laminated. That is, in the laminate (8), the first adhesive layer (adhesive layer C2) with a thickness of 250 μm is exposed.

[0099] (Production Example 14: Production of laminate (9)) A laminate (9) was produced in the same manner as in Production Example 6, except that instead of the resin film with the first adhesive layer, a resin film with an adhesive layer having a thickness of 53 μm in which an acrylic adhesive layer (adhesive layer D) with a thickness of 15 μm and a polyester-based resin film (resin film B1) with a thickness of 38 μm were laminated was laminated.

[0100] (Production Example 15: Production of laminate (10)) A laminate (10) was produced in the same manner as in Production Example 6, except that instead of the resin film with the first adhesive layer, a resin film with an adhesive layer having a thickness of 90 μm in which an acrylic adhesive layer (adhesive layer D) with a thickness of 15 μm and a polyester-based resin film (resin film B2) with a thickness of 75 μm were laminated was laminated.

[0101] (Example 1: Production of pseudo-image display device (1)) The laminate (1) obtained in Production Example 6 was heated at 95°C for 3 hours (heating step), and a pseudo-image display device (1) for evaluation was produced. Table 3 shows the configuration of the laminate (1) and the mode of the heating step in Example 1. Note that "integrated" described in the column of the heating step in Table 3 means that heating was performed in a state where a resin film with a first adhesive layer was laminated on a polarizing plate as a laminate, and it means that the laminate after heating was used as a pseudo-image display device.

[0102] Note that the pseudo-image display device means an evaluation laminate in which a glass plate is laminated as an alternative to the image display cell of the image display device. [Production of Evaluation Sample (Pseudo-Image Display Device with Front Transparent Member)] The pseudo-image display device (1) obtained in Example 1 was allowed to stand in an environment of 23°C and 60% relative humidity for 1 hour. After standing, an 80-μm polyester-based resin film (resin film A1) was peeled off, and non-alkali glass ("EAGLE XG" manufactured by Corning Inc.) was bonded to the exposed 500-μm adhesive layer (adhesive layer C1), and the temperature was 50°C and the pressure was 5 kgf / cm 2 (490.3 kPa), and autoclave treatment was performed for 15 minutes. This was used as an evaluation sample (1-1) (pseudo-image display device (1-1) with front transparent member).

[0103] Note that the pseudo-image display device with front panel means an evaluation laminate in which a glass plate is laminated as an alternative to the image display cell of the image display device with front panel. Six additional types of evaluation samples were produced in the same manner as the above evaluation sample (1-1), except that the standing time of the pseudo-image display device (1) obtained after Example 1 in an environment of 23°C and 60% relative humidity was changed to 6 hours, 24 hours, 36 hours, 72 hours, 96 hours, and 120 hours, respectively. Note that the evaluation sample with a standing time of 6 hours was designated as evaluation sample (1-6), the evaluation sample with a standing time of 24 hours was designated as evaluation sample (1-24), the evaluation sample with a standing time of 36 hours was designated as evaluation sample (1-36), the evaluation sample with a standing time of 72 hours was designated as evaluation sample (1-72), the evaluation sample with a standing time of 96 hours was designated as evaluation sample (1-96), and the evaluation sample with a standing time of 120 hours was designated as evaluation sample (1-120).

[0104] (Examples 2 to 6: Production of Simulated Image Display Devices (2) to (6)) The laminate (2) to the laminate (6) were each heated at 95°C for 3 hours (heating step), and the simulated image display devices (2) to (6) were produced. Table 3 shows the configurations of the laminates (2) to (6) and the modes of the heating steps in Examples 2 to 6.

[0105] Similar to the simulated image display device (1), seven types of evaluation samples with standing times of 1 hour, 6 hours, 24 hours, 36 hours, 72 hours, 96 hours, and 120 hours were produced for each of the simulated image display devices (2) to (6).

[0106] (Comparative Example 1: Production of Simulated Image Display Device (7)) The laminate (7) was heated at 95°C for 3 hours (heating step), and the simulated image display device (7) was produced. Seven types of evaluation samples were produced in the same manner as above, except that the simulated image display device (1) was changed to the simulated image display device (7). Table 3 shows the configuration of the laminate (7) and the mode of the heating step in Comparative Example 1.

[0107] (Comparative Example 2: Production of Simulated Image Display Device (8)) The laminate (8) was heated at 95°C for 3 hours (heating step), and the simulated image display device (8) was produced. Table 3 shows the configuration of the laminate (8) and the mode of the heating step in Comparative Example 2.

[0108] Seven types of evaluation samples were produced in the same manner as the simulated image display device (1), except that the obtained simulated image display device (8) was left standing in an environment of 23°C and 60% relative humidity, and then non-alkali glass (Corning's "EAGLE XG") was bonded to the exposed first adhesive layer (adhesive layer C2) with a thickness of 250 μm, and this was used as an evaluation sample.

[0109] (Comparative Example 3: Production of Simulated Image Display Device (9)) The following pressure-sensitive adhesive sheet (1) was prepared. A polyester resin film (resin film A1) with a thickness of 80 μm having release layers on both sides of a pressure-sensitive adhesive layer (pressure-sensitive adhesive layer C2) with a thickness of 250 μm was laminated to obtain a pressure-sensitive adhesive sheet (1) having a structure of polyester resin film / pressure-sensitive adhesive layer / polyester resin film.

[0110] The pressure-sensitive adhesive sheet (1) and the laminate (9) were each individually heated at 95 °C for 3 hours. After heating, the resin film with the first pressure-sensitive adhesive layer of the laminate (9) was peeled off together with the pressure-sensitive adhesive layer to expose the first protective film. Also, the polyester resin film on one surface of the pressure-sensitive adhesive sheet (1) was peeled off, and the pressure-sensitive adhesive layer side of the pressure-sensitive adhesive sheet was bonded to the first protective film of the laminate (9) to obtain a pseudo-image display device (9). Table 3 shows the configuration of the laminate (9) and the mode of the heating process in Comparative Example 3. Note that "individual" described in the column of the heating process in Table 3 means that the laminate and the pressure-sensitive adhesive sheet (1) were individually heated as described above, and it means that a pseudo-image display device was obtained by bonding the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet (1) to the polarizing plate exposed after heating.

[0111] After the obtained pseudo-image display device (9) was allowed to stand in an environment of 23 °C and 60% relative humidity, the release film on the other surface of the pressure-sensitive adhesive sheet (1) was peeled off from the pseudo-image display device (9), and seven types of evaluation samples were prepared in the same manner as the pseudo-image display device (1) except that non-alkali glass ("EAGLE XG" manufactured by Corning Inc.) was bonded to the surface of the 250-μm pressure-sensitive adhesive layer.

[0112] (Comparative Example 4: Production of pseudo-image display device (10)) A pseudo-image display device (10) and its evaluation samples (seven types) were produced in the same manner as in Comparative Example 3 except that the laminate (8) was changed to a laminate (10). Table 3 shows the configuration of the laminate (10) and the mode of the heating process in Comparative Example 4.

[0113] (Comparative Example 5: Production of pseudo-image display device (11)) The lamination body (2) was used as the pseudo-image display device (11) by omitting the step of heating at 95°C for 3 hours. Seven types of evaluation samples were prepared in the same manner as above, except that the pseudo-image display device (1) was changed to the pseudo-image display device (11).

[0114] <Evaluation of Initial Optical Characteristics> The single transmittance of the seven types of evaluation samples of the pseudo-image display device (1) with a front panel obtained in Example 1 was measured using a spectrocolorimeter / color difference meter (Konica Minolta, Inc. "CM-3700A"). The initial value of the single transmittance and, for the obtained single transmittance, using the color matching function of the C light source, L * a * b * (CIE) chromaticity in the color system was calculated to obtain the single hue b value. Here, the reference value of the single hue b value was set to 6.0 or less. For the evaluation samples exceeding the reference value, it was determined that the optical characteristics deteriorated due to the heating process, that is, they were not suitable for the heating process, and they were excluded from the high-temperature durability evaluation described later. The transmittance of the evaluation samples was measured at wavelengths of 380 to 780 nm.

[0115] For the obtained single transmittance, visual sensitivity correction was performed according to the 2-degree field of view (C light source) of JIS Z 8701:1999 "Color Display Method - XYZ Color System and X10Y10Z10 Color System" to obtain the visually sensitivity-corrected single transmittance (Ty).

[0116] <High-Temperature Durability Evaluation> After the initial optical characteristics evaluation of each of the seven types of evaluation samples of the pseudo-image display device (1), they were left standing in an environment at a temperature of 105°C for 500 hours. The visually sensitivity-corrected single transmittance of each evaluation sample after standing was measured.

[0117] After the measurement, the change amount of the visually sensitivity-corrected single transmittance of each evaluation sample, defined by the following formula (C), was obtained. Formula (C): (Visually sensitivity-corrected single transmittance before standing) - (Visually sensitivity-corrected single transmittance after standing) First, samples with an absolute value of the change in the single transmittance after visual sensitivity correction of less than 3% were selected from among Evaluation Sample (1-1), Evaluation Sample (1-6), Evaluation Sample (1-24), Evaluation Sample (1-36), Evaluation Sample (1-72), Evaluation Sample (1-96), and Evaluation Sample (1-120). Further, among those with an absolute value of the change in the single transmittance after visual sensitivity correction of less than 3%, the one with the longest standing time under the environment of 23°C and 60% relative humidity during the preparation of the evaluation sample was selected, and the standing time under the environment of 23°C and 60% relative humidity during the preparation of the evaluation sample was defined as the "maximum time when polyene formation has not progressed" in Table 3. Hereinafter, the "maximum time when polyene formation has not progressed" may be simply referred to as the "maximum time".

[0118] Similarly, evaluations were performed using the evaluation samples of the pseudo-image display devices (2) to (6), (8) to (11) with front panels. For the pseudo-image display device (7) with a front panel in Comparative Example 1, since the b value of the single color phase exceeded the reference value, high-temperature durability was not performed. The maximum time in Comparative Example 1 in Table 3 was set as "-". In Comparative Example 5, since the absolute value of the change in the single transmittance after visual sensitivity correction was 3% or more for all seven types of evaluation samples, it was determined that polyene formation progressed in less than 1 hour. Therefore, Comparative Example 5 was described as "<1".

[0119]

Table 3

[0120] In Examples 1 to 6, it was confirmed that the maximum time was longer than that in Comparative Examples 1 to 5. That is, it was confirmed that polyene formation was less likely to progress even if time was allowed between the heating step and the next step. Generally, it may take about 24 to 48 hours from the heat treatment of the intermediate laminate to the step of bonding the next front transparent member. In Examples 1 to 5, the maximum time was longer than 48 hours in all cases. Therefore, the time until the next step can be suitably ensured.

[0121] In Examples 2, 4, 5, and 6, the configuration of the resin film with the first adhesive layer is common. On the other hand, Examples 2, 4, 5, and 6 differ in that polarizers (1), (2), (3), and (4) are used, respectively. In these Examples 2, 4, 5, and 6, it was confirmed that the maximum time of Example 2 was the longest, the maximum times of Examples 4 and 6 were the next longest, and the maximum time of Example 5 was the next longest.

[0122] Based on Examples 2, 4, and 5, the following can be considered. The lower the moisture permeability of the first protective film, the more effectively the transfer of moisture to the polarizer after the heating process can be suppressed, and thus the maximum time during which polyene formation has not progressed can be extended.

[0123] Based on Examples 2 and 6, the following can be considered. When the moisture permeability of the second protective film is 1000 (g / m 2 ·24 hours) or less, the transfer of moisture to the polarizer after the heating process can be suppressed, and thus the maximum time during which polyene formation has not progressed can be extended.

[0124] In Comparative Example 1, the moisture permeation rate (1) in the resin film with the first adhesive layer is smaller than a specific range, and the moisture permeation rate (2) is smaller than a specific range. For this reason, although the polarizer (1) is used as in Examples 1 to 3, it is expected that moisture is less likely to escape during the heating process, and it is considered that the optical characteristics have deteriorated due to the heating process.

[0125] In Comparative Example 2, the moisture permeation rate (1) and the moisture permeation rate (2) are larger than a specific range. For this reason, it is considered that the polarizer in the image display device after the heating process is likely to absorb moisture, and it is considered that polyene formation of the polyvinyl alcohol-based resin forming the polarizer is likely to progress.

[0126] In Comparative Examples 3 and 4, although the laminate is heated, after separately heating the laminate provided with a polarizing plate and the resin film with an adhesive layer, the resin film with an adhesive layer is bonded to the polarizing plate, which is different from Example 2. It is considered that polyene formation easily progresses due to moisture being absorbed through the first protective film until the resin film with an adhesive layer is bonded to the first protective film exposed after heating.

[0127] In Comparative Example 5, since the heating step is not performed and the moisture contained in the polarizer cannot be reduced, it is considered that polyene formation of the polyvinyl alcohol-based resin forming the polarizer easily progresses.

Explanation of Reference Numerals

[0128] 10…Image display device with a front transparent member 20…Image display device 30…Polarizing plate 31…Polarizer 32…Adhesive layer 33…First protective film 34…Second protective film 40…Resin film with a first adhesive layer 41…First adhesive layer 42…Resin film 50…Second adhesive layer 60…Image display cell 70…Front transparent member

Claims

1. A method for manufacturing an image display device in which a resin film with a first adhesive layer, a polarizing plate having a polarizer made of a polyvinyl alcohol-based resin film, a second adhesive layer, and an image display cell are laminated in this order, including a step of heating a laminate in which the resin film with the first adhesive layer, the polarizing plate, the second adhesive layer, and the image display cell are laminated in order, wherein the resin film with the first adhesive layer has the resin film and the first adhesive layer laminated in direct contact with each other, The water vapor transmission rate (1) of the resin film with the first adhesive layer, which is determined by the following formula (A), is 5 g / (m ２ ·24 hours) or more and 20 g / (m ２ ·24 hours) or less, and The water vapor transmission rate (2) of the resin film with the first adhesive layer, which is determined by the following formula (B), is 10 g / (m ２ ·24 hours) or more, and and in the laminate, the side of the first adhesive layer in the resin film with the first adhesive layer is laminated on the polarizing plate side. A method for manufacturing an image display device. (Mass of the resin film with the first adhesive layer at the 48-hour time point - Mass of the resin film with the first adhesive layer at the 24-hour time point) / (m ２ · 24 hours) Formula (A) (Mass of the resin film with the first pressure-sensitive adhesive layer at the 72-hour time point - Mass of the resin film with the first pressure-sensitive adhesive layer at the 48-hour time point) / (m ２ ・ 24 hours) Formula (B) (In the formulas (A) and (B), the mass of the resin film with the first adhesive layer at the 24-hour time point refers to the mass per unit area when a resin film with the first adhesive layer processed to a moisture permeation area of 28.26 cm ２ is set in a moisture permeation cup containing about 45 g of calcium chloride, placed in a thermostatic chamber at a temperature of 40 °C and a relative humidity of 90%, and allowed to stand for 24 hours.) The mass of the resin film with the first adhesive layer at the 48-hour time point refers to the mass per unit area when a resin film with the first adhesive layer processed to a moisture permeation area of 28.26 cm ２ is set in a moisture permeation cup containing approximately 45 g of calcium chloride, placed in a constant temperature machine at a temperature of 40°C and a relative humidity of 90%, and left standing for 48 hours, in accordance with the moisture permeability test of JIS Z0208, The mass of the resin film with the first adhesive layer at the 72-hour time point refers to the mass per unit area when a resin film with the first adhesive layer processed to a moisture permeation area of 28.26 cm ２ is set in a moisture permeation cup containing about 45 g of calcium chloride, placed in a constant temperature machine at a temperature of 40°C and a relative humidity of 90%, and left standing for 72 hours.

2. The water permeation rate (2) of the resin film with the first adhesive layer is 40 g / (m ２ ·24 hours) or less. The method for manufacturing an image display device according to claim 1.

3. The water permeation rate (1) of the resin film with the first adhesive layer is 5 g / (m ２ ·24 h) or more and 15 g / (m ２ ·24 h) or less, and The water vapor transmission rate (2) of the resin film with the first adhesive layer is 10 g / (m ２ ·24 hours) or more and 25 g / (m ２ ·24 hours) or less. The method for manufacturing an image display device according to claim 1.

4. The method for manufacturing an image display device according to any one of Claims 1 to 3, characterized in that the water vapor transmission rate (2) of the resin film with the first adhesive layer is greater than the water vapor transmission rate (1) of the resin film with the first adhesive layer.

5. The polarizing plate has the polarizer and a protective film, and the protective film is laminated on the surface of the polarizer on the first adhesive layer side via an adhesive layer. The water vapor permeability of the protective film under the environment of a temperature of 40°C and a relative humidity of 90% is 1000 (g / m ２ ·24 hours) or less. The method for manufacturing an image display device according to any one of claims 1 to 3.

6. A method for manufacturing an image display device with a front transparent member, including a step of peeling the resin film from the image display device obtained by the method for manufacturing an image display device according to Claim 1 and attaching a front transparent member onto the first adhesive layer.

Images