WO2019176719A1

WO2019176719A1 - Laminate, composite polarizing plate and image display device

Info

Publication number: WO2019176719A1
Application number: PCT/JP2019/009070
Authority: WO
Inventors: 寿和松本
Original assignee: 住友化学株式会社
Priority date: 2018-03-12
Filing date: 2019-03-07
Publication date: 2019-09-19

Abstract

The purpose of the present invention is to provide a laminate in which the rate of change of resistance of a transparent conductive layer is small even in a high-temperature and high-humidity environment. In addition, another purpose of the present invention is to provide a composite polarizing plate and an image display device employing said laminate. The present invention provides a laminate characterized in that a transparent conductive layer and a pressure-sensitive adhesive layer having a moisture permeability of 100 g/(m²·day) or less, at a temperature of 40ºC and a relative humidity of 92%R.H., are laminated in contact with each other. It is preferable that the pressure-sensitive adhesive layer be a rubber-based adhesive or a polyolefin-based adhesive.

Description

Laminated body, composite polarizing plate, and image display device

The present invention relates to a laminate, a composite polarizing plate, and an image display device.

In recent years, cellular phones and tablet terminals have been widely used, and liquid crystal display devices and organic EL display devices (OLEDs) have been widely used as image display devices. Under such circumstances, in particular, image display devices having a touch panel function are increasing. In such an image display device, the pressure-sensitive adhesive layer is often arranged so as to be in direct contact with the transparent conductive layer of the touch panel, and adhesion and durability between the transparent conductive layer and the pressure-sensitive adhesive layer are particularly important. It is said that.

In order to solve this problem, Patent Document 1 discloses that a pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive composition containing only a silane compound having an epoxy group is used as a silane coupling agent. . Patent Document 2 discloses that a pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive composition containing a silane compound having two alkoxysilyl groups in the molecule is used as a silane coupling agent. Yes.

In Patent Document 2, the corrosiveness of the transparent conductive layer was also examined and improved, but no countermeasure was taken against the corrosion of the transparent conductive layer in a high-temperature and high-humidity environment.

JP-A-4-223403 JP 2016-101716 A

An object of the present invention is to provide a laminate having a small resistance change rate of a transparent conductive layer even in a high temperature and high humidity environment. Furthermore, another object of the present invention is to provide a composite polarizing plate and an image display device using the same.

That is, the present invention provides the following laminate, composite polarizing plate, and image display device.
[1] Transparent conductive layer, temperature 40 ° C., relative humidity 92% R.D. H. A laminate having a moisture permeability of 100 g / (m ² · day) or less and being laminated in contact with each other.
[2] The adhesive layer is a pressure-sensitive adhesive layer formed from a rubber-based pressure-sensitive adhesive composition containing polyisobutylene and a hydrogen abstraction type photopolymerization initiator. Laminated body.
[3] The laminate according to [1], wherein the adhesive layer is a pressure-sensitive adhesive layer containing a polyolefin resin.
[4] The laminate according to [3], wherein the polyolefin resin includes an amorphous polypropylene resin.
[5] A composite polarizing plate comprising a polarizing film and the laminate according to any one of [1] to [4].
[6] The composite polarizing plate according to [5], wherein the polarizing film has a thickness of 15 μm or less.
[7] An image display device comprising the laminate according to any one of [1] to [4] or the composite polarizing plate according to [5] to [6].

According to the present invention, it is possible to provide a laminate having a small resistance change rate of a transparent conductive layer even in a high temperature and high humidity environment. Furthermore, the present invention can also provide a composite polarizing plate and an image display device with little change in the resistance value of the transparent conductive layer even in a high temperature and high humidity environment.

Hereinafter, preferred embodiments of the present invention will be described, but the present invention is not limited to these embodiments.

(Transparent conductive layer)
In the present invention, the transparent conductive layer is not particularly limited, and examples thereof include a crystalline metal layer or a crystalline metal compound layer. Crystalline can include not only single crystals but also polycrystals in which a large number of crystal grains are aggregated. Examples of components constituting the transparent conductive layer include metal oxides such as silicon oxide, aluminum oxide, titanium oxide, magnesium oxide, zinc oxide, indium oxide, and tin oxide, aluminum, gold, silver, copper, titanium, palladium, and chromium. And metals such as nickel, tungsten, platinum, iron, indium, tin, iridium, rhodium, neodymium, molybdenum, and mixtures thereof. Of these, a crystalline layer mainly composed of indium oxide is preferable, and a layer made of crystalline ITO (Indium Tin Oxide) is particularly preferably used. The transparent conductive layer may be a film formed over the entire surface of the laminate main surface, or may be a metal wiring layer formed of a metal mesh.

“Transparent” means translucent and includes translucent. The transparent conductive layer preferably has a total light transmittance in the visible light wavelength region (for example) of 400 to 800 nm of 50% or more, and preferably 70% or more. When the transparent conductive layer is a metal mesh, the wiring may not be visually recognized by an observer.

In the case where the transparent conductive layer is made of a crystalline material, the crystal grain size is not particularly limited but is preferably 3000 nm or less. When the crystal grain size exceeds 3000 nm, writing durability may be deteriorated. Here, the crystal grain size is defined as the largest diagonal line or diameter in each polygonal or oval region observed under a transmission electron microscope (TEM).

When the transparent conductive layer is not a crystalline film, for example, sliding durability and environmental reliability required for a touch panel may be lowered.

The transparent conductive layer can be formed by a known method. As a method for forming the transparent conductive layer, for example, physical formation methods (Physical Vapor Deposition (hereinafter referred to as “PVD”) such as DC magnetron sputtering method, RF magnetron sputtering method, ion plating method, vacuum deposition method, pulse laser deposition method, etc. "))) Etc. can be used. From the viewpoint of industrial productivity of forming a transparent conductive layer having a uniform film thickness over a large area, the method of forming a transparent conductive layer is preferably a DC magnetron sputtering method. In addition to the above physical formation method (PVD), a chemical vapor deposition method (Chemical Vapor Deposition (hereinafter referred to as “CVD”)) or a sol-gel method may be used. The sputtering method is desirable from the viewpoint of thickness control.

The film thickness of the transparent conductive layer is preferably 5 to 50 nm from the viewpoints of transparency and conductivity. More preferably, it is 5 to 30 nm. If the film thickness of the transparent conductive layer is less than 5 nm, the resistance value tends to be inferior in stability over time.

When the transparent conductive layer is a metal wiring layer composed of a metal mesh, the line width is usually 10 μm or less, preferably 5 μm or less, more preferably 3 μm or less, and usually 0.5 μm or more. Even with such a metal wiring layer having a narrow line width, the laminate of the present invention can suppress corrosion of the transparent conductive layer.

When the transparent conductive layer of the present invention is used for a touch panel, that is, when the touch panel has a transparent conductive layer, the surface resistance value of the transparent conductive layer at a film thickness of 10 to 30 nm is required due to reduction of power consumption of the touch panel and circuit processing. Is preferably in the range of 100 to 2000 Ω / □ (Ω / sq), more preferably in the range of 140 to 1000 Ω / □ (Ω / sq).

The transparent conductive layer used in the present invention may be formed on the surface of a glass substrate or a transparent organic polymer substrate. In that case, the transparent conductive layer may be formed on one side of the substrate or on both sides. The transparent conductive layer may be formed on the entire surface of the main surface of the substrate or may be formed on a part of the substrate. Moreover, after forming a transparent conductive layer on one surface of a glass substrate or a transparent organic polymer substrate, a temperature of 40 ° C. and a relative humidity of 92% R.S. H. The transparent conductive layer may be transferred to an adhesive layer having a moisture permeability of 100 g / (m ² · day) or less.

For example, the transparent organic polymer substrate may be any transparent organic polymer substrate, particularly a transparent organic polymer substrate excellent in heat resistance, transparency, etc. used in the optical field.

Examples of the transparent organic polymer substrate include polyester polymers such as polyethylene terephthalate and polyethylene naphthalate, polycarbonate polymers, cellulose polymers such as diacetyl cellulose and triacetyl cellulose, and transparent polymers such as acrylic polymers such as polymethyl methacrylate. The board | substrate which becomes is mentioned. The transparent organic polymer substrate used in the transparent conductive laminate of the present invention includes polystyrene, styrene-based polymers such as acrylonitrile / styrene copolymer, polyethylene, polypropylene, polyolefin having a cyclic or norbornene structure, and ethylene / propylene copolymer. Examples also include substrates made of transparent polymers such as olefin polymers such as polymers, vinyl chloride polymers, amide polymers typified by nylon and aromatic polyamide. Furthermore, as the transparent organic polymer substrate used in the transparent conductive laminate of the present invention, imide polymer, sulfone polymer, polyether sulfone polymer, polyether ether ketone polymer, polyphenylene sulfide polymer, vinyl alcohol type Examples also include substrates made of transparent polymers such as polymers, vinylidene chloride polymers, vinyl butyral polymers, arylate polymers, polyoxymethylene polymers, epoxy polymers and blends of the above polymers.

In the present invention, among these transparent organic polymer substrates, those having low optical birefringence, those having birefringence controlled to λ / 4 or λ / 2, or those having birefringence not controlled at all are used. It can be selected as appropriate according to the conditions. As mentioned here, when selecting appropriately according to the application, for example, by using polarized light such as linearly polarized light, elliptically polarized light, circularly polarized light, etc. The case where it uses as a display member which expresses a function, and a circularly polarizing plate for reflection prevention used for an organic EL display can be mentioned.

The film thickness of the transparent organic polymer substrate can be appropriately determined, but is generally about 10 to 500 μm, particularly 20 to 300 μm, more preferably 30 to 200 μm, from the viewpoint of workability such as strength and handleability. .

<Adhesive layer>
The adhesive layer is formed on the transparent conductive layer, and the adhesive layer and the transparent conductive layer are laminated in contact with each other. The adhesive layer used in the present invention has a temperature of 40 ° C. and a relative humidity of 92% R.D. H. The water vapor transmission rate is 100 g / (m ² · day) or less. As a result of studies by the present inventors, it has been clarified that the corrosion of the transparent conductive layer in a high-temperature and high-humidity environment is caused by moisture contained in the polarizing plate. In such a laminate having an adhesive layer, the transparent conductive layer is hardly corroded in a high temperature and high humidity environment when the adhesive layer and the transparent conductive layer are laminated in contact with each other. It becomes. In the present specification, the adhesive layer or the pressure-sensitive adhesive layer may be collectively referred to as “adhesive layer”.

The moisture permeability of the adhesive layer is 100 g / (m ² · day) or less, preferably 50 g / (m ² · day) or less, and 30 g / (m ² · day) or less. Is more preferably 20 g / (m ² · day) or less. Further, the lower limit value of moisture permeability is not particularly limited, but ideally, it is preferable that water vapor is not permeated at all (that is, 0 g / (m ² · day)). The water vapor transmission rate is 40 ° C. when the thickness of the adhesive layer is 50 μm, and the relative humidity is 92% R.D. H. It is a water vapor transmission rate (moisture permeability) under conditions, and the measurement method can follow the method described in the examples.

<Adhesive layer>
The adhesive layer can be a layer for adhering the transparent conductive layer and a polarizing plate described later. As the adhesive layer, a temperature of 40 ° C. and a relative humidity of 92% R.D. H. The water vapor transmission rate in the case may be 100 g / (m ² · day) or less. The composition of the adhesive forming the adhesive layer is not particularly limited, and a layer made of any appropriate adhesive can be adopted. Examples of such adhesives include natural rubber adhesives, α-olefin adhesives, urethane resin adhesives, ethylene-vinyl acetate resin emulsion adhesives, ethylene-vinyl acetate resin hot melt adhesives, and epoxy resins. Adhesives, vinyl chloride resin solvent adhesives, chloroprene rubber adhesives, cyanoacrylate adhesives, silicone adhesives, styrene-butadiene rubber solvent adhesives, nitrile rubber adhesives, nitrocellulose adhesives, Reactive hot melt adhesives, phenol resin adhesives, modified silicone adhesives, polyester hot melt adhesives, polyamide resin hot melt adhesives, polyimide adhesives, polyurethane resin hot melt adhesives, polyolefin resin hot melt adhesives Adhesive, polyvinyl acetate resin solvent-based adhesive, Styrene resin solvent adhesive, polyvinyl alcohol adhesive, polyvinyl pyrrolidone resin adhesive, polyvinyl butyral adhesive, polybenzimidazole adhesive, polymethacrylate resin solvent adhesive, melamine resin adhesive, urea resin adhesive Agents, resorcinol adhesives, and the like. Such an adhesive agent can be used individually by 1 type or in mixture of 2 or more types.

Examples of adhesives include, for example, thermosetting adhesives and hot-melt adhesives when classified according to the adhesive form. Only one kind of such an adhesive may be used, or two or more kinds may be used.

A thermosetting adhesive exhibits an adhesive force when cured by heating and solidified. Examples of the thermosetting adhesive include an epoxy thermosetting adhesive, a urethane thermosetting adhesive, and an acrylic thermosetting adhesive. The curing temperature of the thermosetting adhesive is, for example, 100 to 200 ° C.

The hot melt adhesive is melted or softened by heating, thermally fused to the adherend, and then solidified by cooling to adhere to the adherend. Examples of hot melt adhesives include rubber hot melt adhesives, polyester hot melt adhesives, polyolefin hot melt adhesives, ethylene-vinyl acetate resin hot melt adhesives, polyamide resin hot melt adhesives, and polyurethane resins. Examples thereof include hot melt adhesives. The softening temperature (ring ball method) of the hot melt adhesive is, for example, 100 to 200 ° C. The melt viscosity of the hot melt adhesive is 180 ° C., for example, 100 to 30000 mPa · s.

The thickness of the adhesive layer is not particularly limited, but is preferably about 0.01 to 10 μm, and more preferably about 0.05 to 8 μm.

<Adhesive layer>
An adhesive layer can be a layer for adhere | attaching a transparent conductive layer and the below-mentioned polarizing plate. The pressure-sensitive adhesive layer has a temperature of 40 ° C. and a relative humidity of 92% R.D. H. The water vapor transmission rate in the case may be 100 g / (m ² · day) or less. The composition of the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer is not particularly limited, and a layer composed of any appropriate pressure-sensitive adhesive can be adopted. Examples of the adhesive include rubber adhesives, polyolefin adhesives, acrylic adhesives, silicone adhesives, urethane adhesives, vinyl alkyl ether adhesives, polyvinyl alcohol adhesives, and polyvinylpyrrolidone adhesives. , Polyacrylamide pressure-sensitive adhesives, cellulose-based pressure-sensitive adhesives, and the like. Among these, rubber pressure-sensitive adhesives and polyolefin pressure-sensitive adhesives are preferable from the viewpoint of moisture permeability.

The rubber-based pressure-sensitive adhesive only needs to contain a rubber-based polymer, and its composition is not particularly limited.

The rubber polymer used in the present invention is a polymer exhibiting rubber elasticity in a temperature range near room temperature. Specific examples include styrene-based thermoplastic elastomers and isobutylene-based polymers. In the present invention, from the viewpoint of weather resistance, polyisobutylene (PIB), which is a homopolymer of isobutylene, is used. Is preferred. This is because polyisobutylene has excellent light resistance because it does not contain a double bond in the main chain.

As the polyisobutylene, for example, commercially available products such as OPPANOL manufactured by BASF can be used.

The weight average molecular weight (Mw) of the polyisobutylene is preferably 100,000 or more, more preferably 300,000 or more, further preferably 600,000 or more, and particularly preferably 700,000 or more. . The upper limit of the weight average molecular weight is not particularly limited, but is preferably 5 million or less, more preferably 3 million or less, and even more preferably 2 million or less. By setting the weight average molecular weight of the polyisobutylene to 100,000 or more, it is possible to obtain a rubber-based pressure-sensitive adhesive that is more excellent in durability during high-temperature storage.

The content of the polyisobutylene is not particularly limited, but is preferably 50% by weight or more, more preferably 60% by weight or more in the total solid content of the rubber-based pressure-sensitive adhesive, and 70% by weight. % Or more, more preferably 80% by weight or more, still more preferably 85% by weight or more, and particularly preferably 90% by weight or more. The upper limit of the content of polyisobutylene is not particularly limited, and is preferably 99% by weight or less, and more preferably 98% by weight or less. It is preferable that polyisobutylene is contained in the above range because it is excellent in low moisture permeability.

Further, the rubber-based pressure-sensitive adhesive used in the present invention may contain a polymer, an elastomer, or the like other than the polyisobutylene. Specifically, copolymers of isobutylene and normal butylene, copolymers of isobutylene and isoprene (for example, butyl rubbers such as regular butyl rubber, chlorinated butyl rubber, brominated butyl rubber, and partially crosslinked butyl rubber), and vulcanization thereof And modified products (for example, those modified with a functional group such as a hydroxyl group, a carboxyl group, an amino group, and an epoxy group); styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-isoprene -Styrene block copolymer (SIS), Styrene-butadiene-styrene block copolymer (SBS), Styrene-ethylene-propylene-styrene block copolymer (SEPS, SIS hydrogenated product), Styrene-ethylene-propylene block Copolymer (SEP, styrene-a Styrene-based thermoplastic elastomers such as styrene-based block copolymers such as styrene-isobutylene-styrene block copolymer (SIBS) and styrene-butadiene rubber (SBR); butyl rubber (IIR), Butadiene rubber (BR), acrylonitrile-butadiene rubber (NBR), EPR (binary ethylene-propylene rubber), EPT (ternary ethylene-propylene rubber), acrylic rubber, urethane rubber, polyurethane thermoplastic elastomer; polyester Thermoplastic elastomers; blend thermoplastic elastomers such as polymer blends of polypropylene and EPT (ternary ethylene-propylene rubber). These can be added within a range that does not impair the effects of the present invention, but is preferably about 10 parts by weight or less with respect to 100 parts by weight of the polyisobutylene, and may not be included from the viewpoint of durability. preferable.

Further, it is particularly preferable that the rubber-based pressure-sensitive adhesive used in the present invention contains the polyisobutylene and a hydrogen abstraction type photopolymerization initiator.

The hydrogen abstraction type photopolymerization initiator is capable of drawing a hydrogen from the polyisobutylene and creating a reactive site in the polyisobutylene without irradiating the initiator itself by irradiating active energy rays. . By forming the reaction point, the crosslinking reaction of polyisobutylene can be started.

As the photopolymerization initiator, in addition to the hydrogen abstraction type photopolymerization initiator used in the present invention, there are also cleavage type photopolymerization initiators that generate radicals by cleavage of the photopolymerization initiator itself upon irradiation with active energy rays. Are known. However, when a cleavage type photopolymerization initiator is used for the polyisobutylene used in the present invention, the main chain of polyisobutylene is cleaved by the photopolymerization initiator in which radicals are generated, and cannot be crosslinked. In the present invention, by using a hydrogen abstraction type photopolymerization initiator, polyisobutylene can be crosslinked as described above.

Examples of the hydrogen abstraction type photopolymerization initiator include acetophenone, benzophenone, methyl-4-phenylbenzophenone o-benzoylbenzoate, 4,4′-dichlorobenzophenone, hydroxybenzophenone, 4,4′-dimethoxybenzophenone, 4,4 '-Dichlorobenzophenone, 4,4'-dimethylbenzophenone, 4-benzoyl-4'-methyl-diphenyl sulfide, acrylated benzophenone, 3,3', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone, Benzophenone compounds such as 3,3′-dimethyl-4-methoxybenzophenone; thioxanes such as 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone Compounds such as 4,4′-bis (dimethylamino) benzophenone and 4,4′-diethylaminobenzophenone; 10-butyl-2-chloroacridone, 2-ethylanthraquinone, 9,10- Examples thereof include phenanthrenequinone and camphorquinone; aromatic ketone compounds such as acetonaphthone and 1-hydroxycyclohexyl phenyl ketone; aromatic aldehydes such as terephthalaldehyde; and quinone aromatic compounds such as methylanthraquinone. These can be used individually by 1 type or in mixture of 2 or more types. Among these, from the viewpoint of reactivity, a benzophenone-based compound is preferable, and benzophenone is more preferable.

The content of the hydrogen abstraction type photopolymerization initiator is preferably 0.001 to 10 parts by weight, more preferably 0.005 to 10 parts by weight with respect to 100 parts by weight of the polyisobutylene. More preferably, it is 0.01 to 10 parts by weight. It is preferable to include a hydrogen abstraction type photopolymerization initiator in the above-mentioned range since the crosslinking reaction can proceed to a target density.

In the present invention, a cleavage type photopolymerization initiator may be used together with the hydrogen abstraction type photopolymerization initiator as long as the effects of the present invention are not impaired. .

The rubber-based pressure-sensitive adhesive used in the present invention can further contain a polyfunctional radically polymerizable compound. In the present invention, the polyfunctional radically polymerizable compound functions as a crosslinking agent for polyisobutylene.

The polyfunctional radical polymerizable compound is a compound having at least two radical polymerizable functional groups having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group. Specific examples of the polyfunctional radical polymerizable compound include, for example, tripropylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and 1,9-nonanediol. Di (meth) acrylate, 1,10-decanediol di (meth) acrylate, 2-ethyl-2-butylpropanediol di (meth) acrylate, bisphenol A di (meth) acrylate, bisphenol A ethylene oxide adduct di (meth) ) Acrylate, bisphenol A propylene oxide adduct di (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, neopentyl glycol di (meth) acrylate, tricyclodecane dimethanol di (meth) Cleats, dioxane glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meta) ) Acrylate, EO-modified diglycerin tetra (meth) acrylate, etc., esterified products of (meth) acrylic acid and polyhydric alcohol, 9,9-bis [4- (2- (meth) acryloyloxyethoxy) phenyl] fluorene, etc. Can be mentioned. These can be used singly or as a mixture of two or more. Among these, from the viewpoint of compatibility with polyisobutylene, an esterified product of (meth) acrylic acid and a polyhydric alcohol is preferable, and a bifunctional (meth) acrylate having two (meth) acryloyl groups, a (meth) acryloyl group. Are more preferable, and tricyclodecane dimethanol di (meth) acrylate and trimethylolpropane tri (meth) acrylate are particularly preferable.

The content of the polyfunctional radically polymerizable compound is preferably 20 parts by weight or less, more preferably 15 parts by weight or less, and further preferably 10 parts by weight or less based on 100 parts by weight of the polyisobutylene. preferable. Further, the lower limit value of the content of the polyfunctional radical polymerizable compound is not particularly limited. For example, it is preferably 0.1 parts by weight or more with respect to 100 parts by weight of the polyisobutylene, More preferably, it is more than 1 part by weight, and still more preferably 1 part by weight. It is preferable from a viewpoint of durability of the obtained rubber-type adhesive layer that content of a polyfunctional radically polymerizable compound exists in the said range.

The molecular weight of the polyfunctional radically polymerizable compound is not particularly limited, but is preferably about 1000 or less, and more preferably about 500 or less.

The rubber-based pressure-sensitive adhesive used in the present invention contains at least one tackifier selected from the group consisting of a tackifier containing a terpene skeleton, a tackifier containing a rosin skeleton, and a hydrogenated product thereof. Can do. By including a tackifier in the rubber-based pressure-sensitive adhesive, it is possible to form a rubber-based pressure-sensitive adhesive layer having high adhesion to various adherends and high durability even in a high temperature environment. Therefore, it is preferable.

Examples of the tackifier containing the terpene skeleton include terpene polymers such as α-pinene polymer, β-pinene polymer and dipentene polymer, and modified terpene polymers (phenol-modified, styrene-modified, aromatic). Modified terpene resin and the like). Examples of the modified terpene resin include terpene phenol resin, styrene modified terpene resin, aromatic modified terpene resin, hydrogenated terpene resin (hydrogenated terpene resin) and the like. Examples of the hydrogenated terpene resin herein include a hydride of a terpene polymer and other modified terpene resins and hydrogenated terpene phenol resins. Among these, from the viewpoint of compatibility with the rubber-based pressure-sensitive adhesive and pressure-sensitive adhesive properties, hydrogenated products of terpene phenol resins are preferable.

Examples of the tackifier containing the rosin skeleton include rosin resin, polymerized rosin resin, hydrogenated rosin resin, rosin ester resin, hydrogenated rosin ester resin, rosin phenol resin, and the like. Specifically, gum rosin, wood rosin, Unmodified rosin such as tall oil rosin (raw rosin), hydrogenated, disproportionated, polymerized, other chemically modified modified rosin, and derivatives thereof can be used.

As the tackifier, for example, commercially available products such as the Clearon series, Polystar series, Superester series, Pencel series, Pine Crystal series, etc. manufactured by Yashara Chemical Co., Ltd. may be used. it can.

When the tackifier is a hydrogenated product, the hydrogenation may be a partially hydrogenated product that has been partially hydrogenated, and all the double bonds in the compound are fully hydrogenated. It may be a hydrogenated product. In the present invention, a completely hydrogenated product is preferred from the viewpoints of adhesive properties, weather resistance and hue.

The tackifier preferably contains a cyclohexanol skeleton from the viewpoint of adhesive properties. Although the detailed principle is unknown, it is thought that the cyclohexanol skeleton is more compatible with the base polymer polyisobutylene than the phenol skeleton. As a tackifier containing a cyclohexanol skeleton, for example, hydrogenated products such as terpene phenol resin and rosin phenol resin are preferable, and complete hydrogenated products such as terpene phenol resin and rosin phenol resin are more preferable.

The softening point (softening temperature) of the tackifier is not particularly limited, but is preferably about 80 ° C. or higher, and more preferably about 100 ° C. or higher. It is preferable that the tackifier has a softening point of 80 ° C. or higher because the tackifier can be kept soft without being softened even at high temperatures. The upper limit value of the softening point of the tackifier is not particularly limited, but if the softening point becomes too high, the molecular weight becomes higher, the compatibility deteriorates, and problems such as whitening may occur. The temperature is preferably about 200 ° C. or less, and preferably about 180 ° C. or less. In addition, the softening point of the tackifier resin here is defined as a value measured by a softening point test method (ring ball method) defined in either JIS K5902 or JIS K2207.

The weight average molecular weight (Mw) of the tackifier is not particularly limited, but is preferably 50,000 or less, preferably 30,000 or less, and more preferably 10,000 or less, It is more preferably 8000 or less, and particularly preferably 5000 or less. Moreover, the lower limit of the weight average molecular weight of the tackifier is not particularly limited, but is preferably 500 or more, more preferably 1000 or more, and further preferably 2000 or more. It is preferable that the weight average molecular weight of the tackifier is in the above range because the compatibility with polyisobutylene is good and problems such as whitening do not occur.

The addition amount of the tackifier is preferably 40 parts by weight or less, more preferably 30 parts by weight or less, and further preferably 20 parts by weight or less with respect to 100 parts by weight of the polyisobutylene. . Moreover, the lower limit of the addition amount of the tackifier is not particularly limited, but is preferably 0.1 parts by weight or more, more preferably 1 part by weight or more, and 5 parts by weight or more. More preferably. By making the usage-amount of a tackifier into the said range, since an adhesive characteristic can be improved, it is preferable. Moreover, when the usage-amount of a tackifier exceeds the said range and adds in large quantities, there exists a tendency for the cohesive force of an adhesive to fall, and it is unpreferable.

Further, a tackifier other than the tackifier containing the terpene skeleton and the tackifier containing the rosin skeleton can be added to the rubber-based adhesive used in the present invention. Examples of the tackifier include petroleum resin-based tackifiers. Examples of the petroleum-based tackifier include aromatic petroleum resins, aliphatic petroleum resins, alicyclic petroleum resins (aliphatic cyclic petroleum resins), aliphatic / aromatic petroleum resins, aliphatic / aliphatic resins. Examples thereof include cyclic petroleum resins, hydrogenated petroleum resins, coumarone resins, coumarone indene resins, and the like.

The petroleum resin-based tackifier can be used within a range that does not impair the effects of the present invention.

An organic solvent can be added as a diluent to the rubber-based adhesive. The diluent is not particularly limited, and examples thereof include toluene, xylene, n-heptane, dimethyl ether, and the like. These may be used alone or in combination of two or more. it can. Among these, toluene is preferable.

The addition amount of the diluent is not particularly limited, but it is preferably about 50 to 95% by weight and more preferably about 70 to 90% by weight in the rubber adhesive. When the addition amount of the diluent is within the above range, it is preferable from the viewpoint of coatability to a support or the like.

Additives other than those described above can be added to the rubber-based pressure-sensitive adhesive used in the present invention as long as the effects of the present invention are not impaired. Specific examples of the additive include a softening agent, a crosslinking agent (for example, polyisocyanate, epoxy compound, alkyl etherified melamine compound, etc.), filler, anti-aging agent, ultraviolet absorber and the like. The kind, combination, addition amount, and the like of the additive added to the rubber-based pressure-sensitive adhesive can be appropriately set according to the purpose. The content (total amount) of the additive in the rubber-based pressure-sensitive adhesive is preferably 30% by weight or less, more preferably 20% by weight or less, and still more preferably 10% by weight or less.

The rubber-based pressure-sensitive adhesive layer used in the present invention can be formed from the above-mentioned pressure-sensitive adhesive, and the production method is not particularly limited. Thus, an adhesive layer can be formed.

When polyisobutylene is included as the rubber-based pressure-sensitive adhesive, it is preferable to crosslink the polyisobutylene by irradiating the pressure-sensitive adhesive with active energy rays. In general, the active energy ray is applied to the obtained coating layer by applying the rubber-based pressure-sensitive adhesive to various supports.
Moreover, the irradiation of the active energy ray may be performed directly on the coating layer (without bonding other members or the like), or after bonding various members such as an optical film such as a separator or glass to the coating layer. May be. In the case of irradiation after bonding to the optical film or various members, active energy rays may be irradiated through the optical film or various members, and the optical film or various members are peeled off, and the peeled surface is used. You may irradiate an active energy ray.

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

When the pressure-sensitive adhesive coating layer is heat-dried, the heat-drying temperature is preferably about 30 ° C to 200 ° C, more preferably 40 ° C to 180 ° C, and still more preferably 80 ° C to 150 ° C. By setting the heating temperature in the above range, an adhesive layer having excellent adhesive properties can be obtained. As the drying time, an appropriate time can be adopted as appropriate. The drying time is preferably about 5 seconds to 20 minutes, more preferably 30 seconds to 10 minutes, and further preferably 1 minute to 8 minutes.

Further, even when the active energy ray is irradiated to the pressure-sensitive adhesive coating layer, when the adhesive or the pressure-sensitive adhesive contains an organic solvent as a diluent, it is heated and dried after the application and before the active energy ray irradiation. It is preferable to remove the solvent and the like.

The heating and drying temperature is not particularly limited, but is preferably about 30 ° C. to 90 ° C., more preferably about 60 ° C. to 80 ° C. from the viewpoint of reducing the residual solvent. As the drying time, an appropriate time can be adopted as appropriate. The drying time is preferably about 5 seconds to 20 minutes, more preferably 30 seconds to 10 minutes, and further preferably 1 minute to 8 minutes.

Examples of the active energy rays include visible light, ultraviolet rays, and electron beams. Among these, ultraviolet rays are preferable.

The irradiation condition of ultraviolet rays is not particularly limited, and can be set to any appropriate condition depending on the composition of the rubber-based pressure-sensitive adhesive composition to be crosslinked. For example, the integrated irradiation light amount is 100 mJ / cm ^2. ˜2000 mJ / cm ² is preferred.

As the support, for example, a peeled sheet (separator) can be used.

Examples of the constituent material of the separator include plastic materials such as polyethylene, polypropylene, polyethylene terephthalate, and polyester films, porous materials such as paper, cloth, and nonwoven fabric, nets, foamed sheets, metal foils, and laminates thereof. Although an appropriate thin leaf body etc. can be mentioned, a plastic film is used suitably from the point which is excellent in surface smoothness.

Examples of the plastic film include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, polyurethane film, and ethylene. -Vinyl acetate copolymer film and the like.

The thickness of the separator is usually about 5 to 200 μm, preferably about 5 to 100 μm. For the separator, silicone type, fluorine type, long chain alkyl type or fatty acid amide type release agent, release by silica powder, etc., and antifouling treatment, coating type, kneading type, vapor deposition, if necessary An antistatic treatment such as a mold can also be performed. In particular, the release property from the pressure-sensitive adhesive layer can be further improved by appropriately performing a release treatment such as a silicone treatment, a long-chain alkyl treatment, or a fluorine treatment on the surface of the separator.

When the adhesive layer is formed on a release-treated sheet (separator), the pressure-sensitive adhesive layer can be transferred onto the transparent conductive layer to form the laminate of the present invention.

The thickness of the pressure-sensitive adhesive layer is not particularly limited and can be appropriately set depending on the application, but is preferably 250 μm or less, more preferably 100 μm or less, and 55 μm or less. More preferably. Further, the lower limit of the thickness of the pressure-sensitive adhesive layer is not particularly limited, but from the viewpoint of durability, it is preferably 1 μm or more, more preferably 5 μm or more, and more than 15 μm. Further preferred.

The gel fraction of the pressure-sensitive adhesive layer used in the present invention is not particularly limited, but is preferably about 10 to 98%, more preferably about 25 to 98%, and further preferably about 45 to 90%. It is preferable for the gel fraction to be in the above range since both durability and adhesive strength can be achieved.

The polyolefin pressure-sensitive adhesive only needs to contain a polyolefin-based resin, and the composition thereof is not particularly limited.

Specific examples of polyolefin resins include low density polyethylene, ultra-low density polyethylene, low crystalline polypropylene, amorphous propylene- (1-butene) copolymer, ionomer resin, ethylene-vinyl acetate copolymer, ethylene- ( Examples thereof include ethylene copolymers such as (meth) acrylic acid copolymers, ethylene- (meth) acrylic acid ester-maleic anhydride copolymers, ethylene-glycidyl methacrylate copolymers, and polyolefin-modified polymers.
The pressure-sensitive adhesive layer preferably contains an amorphous polypropylene resin, and more preferably contains an amorphous propylene- (1-butene) copolymer. If it is such an adhesive layer, the adhesive sheet which is further excellent in level | step difference followable | trackability can be obtained. In this specification, “amorphous” means a property that does not have a clear melting point such as crystalline.

The content ratio of the amorphous propylene- (1-butene) copolymer contained in the pressure-sensitive adhesive can be appropriately adjusted so that the elastic value of the pressure-sensitive adhesive layer is 0.7 N / mm or less. The content ratio of the amorphous propylene- (1-butene) copolymer contained in the pressure-sensitive adhesive is preferably 10% by weight to 100% by weight, more preferably 10% by weight to 95% by weight. is there.

The amorphous propylene- (1-butene) copolymer can be obtained by polymerizing propylene and 1-butene, preferably using a metallocene catalyst. More specifically, the amorphous propylene- (1-butene) copolymer is subjected to a polymerization step of polymerizing propylene and 1-butene using, for example, a metallocene catalyst, and the catalyst residue is removed after the polymerization step. It can be obtained by performing post-processing steps such as a step and a foreign matter removing step. The amorphous propylene- (1-butene) copolymer is obtained through such a process, for example, in a powder form, a pellet form or the like. Examples of the metallocene catalyst include a metallocene homogeneous mixed catalyst containing a metallocene compound and an aluminoxane, a metallocene supported catalyst in which a metallocene compound is supported on a particulate carrier, and the like.

The amorphous propylene- (1-butene) copolymer polymerized using the metallocene catalyst as described above exhibits a narrow molecular weight distribution. The molecular weight distribution (Mw / Mn) of the amorphous propylene- (1-butene) copolymer is preferably 3 or less, more preferably 2 or less, even more preferably 1.1 to 2, particularly It is preferably 1.2 to 1.9. Amorphous propylene- (1-butene) copolymer having a narrow molecular weight distribution has few low molecular weight components. Therefore, if such an amorphous propylene- (1-butene) copolymer is used, bleeding of low molecular weight components can be achieved. It is possible to obtain a pressure-sensitive adhesive layer that can prevent the adherend from being contaminated.

In the amorphous propylene- (1-butene) copolymer, the content of propylene-derived structural units is preferably 80 mol% to 99 mol%, more preferably 85 mol% to 99 mol%, Preferably, it is 90 mol% to 99 mol%.

The content ratio of the structural unit derived from 1-butene in the amorphous propylene- (1-butene) copolymer is preferably 1 mol% to 20 mol%, more preferably 1 mol% to 15 mol%, Preferably, it is 1 mol% to 10 mol%. If it is such a range, the adhesive layer excellent in the balance of toughness and a softness | flexibility can be obtained.

The amorphous propylene- (1-butene) copolymer may be a block copolymer or a random copolymer.

The amorphous propylene- (1-butene) copolymer has a weight average molecular weight (Mw) of preferably 200,000 or more, more preferably 200,000 to 500,000, still more preferably 200,000. ~ 300,000. If the weight average molecular weight (Mw) of the amorphous propylene- (1-butene) copolymer is in such a range, a general styrene-based thermoplastic resin or acrylic thermoplastic resin (Mw is 100,000 or less) ), The pressure-sensitive adhesive layer can be obtained with less low molecular weight components and capable of preventing contamination of the adherend.

The melt flow rate of the amorphous propylene- (1-butene) copolymer at 230 ° C. and 2.16 kgf is preferably 1 g / 10 min to 50 g / 10 min, more preferably 5 g / 10 min to 30 g / 10 min. And more preferably 5 g / 10 min to 20 g / 10 min. When the melt flow rate of the amorphous propylene- (1-butene) copolymer is within such a range, a pressure-sensitive adhesive layer having a uniform thickness can be formed by coextrusion molding without processing defects. The melt flow rate can be measured by a method according to JISK7210.

The amorphous propylene- (1-butene) copolymer may further contain other monomer-derived structural units as long as the effects of the present invention are not impaired. Examples of other monomers include α-olefins such as ethylene, 1-pentene, 1-hexene, 1-octene, 1-decene, 4-methyl-1-pentene and 3-methyl-1-pentene. .

The pressure-sensitive adhesive layer preferably further contains a crystalline polypropylene resin. By containing the crystalline polypropylene resin, the elastic modulus E ′ at 70 ° C. of the pressure-sensitive adhesive layer can be adjusted to a desired value. The content ratio of the crystalline polypropylene resin can be set to any appropriate ratio depending on the desired elastic modulus E ′. The content of the crystalline polypropylene resin is preferably 0% by weight to 90% by weight with respect to the total weight of the amorphous propylene- (1-butene) copolymer and the crystalline polypropylene resin. More preferably, it is 5 to 90% by weight.

The crystalline polypropylene resin may be homopolypropylene or a copolymer obtained from propylene and a monomer copolymerizable with propylene. Examples of monomers copolymerizable with propylene include α-olefins such as ethylene, 1-pentene, 1-hexene, 1-octene, 1-decene, 4-methyl-1-pentene, and 3-methyl-1-pentene. Etc. When the crystalline polypropylene resin is a copolymer obtained from propylene and a monomer copolymerizable with propylene, it may be a random copolymer or a block copolymer.

The crystalline polypropylene resin is preferably obtained by polymerization using a metallocene catalyst, like the amorphous propylene- (1-butene) copolymer. By using the crystalline polypropylene resin thus obtained, it is possible to prevent contamination of the adherend due to bleeding of low molecular weight components.

The crystallinity of the crystalline polypropylene resin is preferably 10% or more, more preferably 20% or more. The crystallinity is typically determined by differential scanning calorimetry (DSC) or X-ray diffraction.

Preferably, the pressure-sensitive adhesive layer contains F ⁻ , Cl ⁻ , Br ⁻ , NO ₂ ⁻ , NO ₃ ⁻ , SO ₄ ²⁻ , Li ⁺ , Na ⁺ , K ⁺ , Mg ²⁺ , Ca ²⁺ and NH ₄ ⁺ . It does not contain substantially. This is because it is possible to prevent the adherend from being contaminated with the ions. The pressure-sensitive adhesive layer containing no ions can be obtained, for example, by subjecting the amorphous propylene- (1-butene) copolymer contained in the pressure-sensitive adhesive layer to solution polymerization using a metallocene catalyst as described above. it can.
In solution polymerization using the metallocene catalyst, the amorphous propylene- (1-butene) copolymer is purified by repeating precipitation isolation (reprecipitation method) using a poor solvent different from the polymerization solvent. Therefore, a pressure-sensitive adhesive layer that does not contain the ions can be obtained. In the present specification, “F ⁻ , Cl ⁻ , Br ⁻ , NO ₂ ⁻ , NO ₃ ⁻ , SO ₄ ²⁻ , Li ⁺ , Na ⁺ , K ⁺ , Mg ²⁺ , Ca ²⁺ and NH ₄ ⁺ are substantially “Not included” means that it is below the detection limit in standard ion chromatographic analysis (for example, ion chromatographic analysis using trade names “DX-320” and “DX-500” manufactured by Dionex). Say. Specifically, for 1 g of the adhesive layer,
F ⁻ , Cl ⁻ , Br ⁻ , NO ₂ ⁻ , NO ₃ ⁻ , SO ₄ ²⁻ and K ⁺ are each 0.49 μg or less, Li ⁺ and Na ⁺ are each 0.20 μg or less, and Mg ²⁺ and Ca ²⁺ are each This refers to a case where 0.97 μg or less and NH ₄ ⁺ is 0.5 μg or less.

The pressure-sensitive adhesive layer may further contain other components as long as the effects of the present invention are not impaired. Examples of the other components include an antioxidant, an ultraviolet absorber, a light stabilizer, a heat resistance stabilizer, and an antistatic agent. The kind and usage-amount of another component can be suitably selected according to the objective.

The polyolefin-based pressure-sensitive adhesive layer used in the present invention can be formed from the above-mentioned pressure-sensitive adhesive, and its production method is not particularly limited, but the pressure-sensitive adhesive is extruded and molded on various supports, etc., and dried by heating or irradiation with active energy rays. Thus, the pressure-sensitive adhesive layer can be formed.

The molding temperature in the extrusion molding is preferably 160 ° C. to 220 ° C., more preferably 170 ° C. to 200 ° C. Within such a range, the molding stability is excellent.

As the support, for example, a peeled sheet (separator) can be used.

(Laminate)
In the laminate of the present invention, the transparent conductive layer, temperature 40 ° C., relative humidity 92% R.D. H. And the adhesive layer having a moisture permeability of 100 g / (m ² · day) or less are laminated in contact with each other. A temperature of 40 ° C. and a relative humidity of 92% R.D. H. The pressure-sensitive adhesive layer having a moisture permeability of 100 g / (m ² · day) or less may be disposed, or may be disposed on both sides. The manufacturing method of a laminated body is not specifically limited, It can carry out by a well-known method.

(Polarizing film)
The polarizing film is not particularly limited, and various types can be used. Examples of polarizing films include hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, ethylene / vinyl acetate copolymer partially saponified films, and dichroism of iodine and dichroic dyes. Examples thereof include polyene-based oriented films such as those obtained by adsorbing substances and uniaxially stretched, polyvinyl alcohol dehydrated products and polyvinyl chloride dehydrochlorinated products. Among these, a polarizing film made of a polyvinyl alcohol film and a dichroic substance such as iodine is preferable. The thickness of these polarizing films is not particularly limited, but is generally about 3 to 80 μm.

As the polyvinyl alcohol film, a saponified polyvinyl acetate resin can be used. Examples of the polyvinyl acetate resin include, in addition to polyvinyl acetate, which is a homopolymer of vinyl acetate, copolymers with other monomers copolymerizable with vinyl acetate. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having an ammonium group.

The degree of saponification of the polyvinyl alcohol-based resin is usually about 85 to 100 mol%, preferably 98 mol% or more. This polyvinyl alcohol-based resin may be modified, and for example, polyvinyl formal and polyvinyl acetal modified with aldehydes can also be used. The degree of polymerization of the polyvinyl alcohol resin is usually about 1,000 to 10,000, preferably about 1,500 to 5,000.

A film made of a polyvinyl alcohol resin is used as an original film of a polarizing film. The method for forming a polyvinyl alcohol-based resin can be formed by a known method. The film thickness of the polyvinyl alcohol-based raw film is preferably about 5 to 35 μm, more preferably 5 to 20 μm, considering that the thickness of the obtained polarizing film is 15 μm or less. When the film thickness of the raw film is 35 μm or more, it is necessary to increase the draw ratio when producing the polarizing film, and the dimensional shrinkage of the resulting polarizing film tends to increase. On the other hand, when the film thickness of the raw film is 5 μm or less, the handling property at the time of stretching is lowered, and there is a tendency that problems such as cutting are likely to occur during production.

The uniaxial stretching of the polyvinyl alcohol-based resin film can be performed before, simultaneously with, or after the dyeing of the dichroic dye. When uniaxial stretching is performed after dyeing, this uniaxial stretching may be performed before boric acid treatment or during boric acid treatment. Moreover, you may uniaxially stretch in these several steps.

In the uniaxial stretching, rolls having different peripheral speeds may be uniaxially stretched or may be stretched uniaxially using a hot roll. Further, the uniaxial stretching may be dry stretching in which stretching is performed in the air, or may be wet stretching in which stretching is performed in a state where a solvent is used and the polyvinyl alcohol-based resin film is swollen. The draw ratio is usually about 3 to 8 times.

As a method for dyeing a polyvinyl alcohol resin film with a dichroic dye, for example, a method of immersing the polyvinyl alcohol resin film in an aqueous solution containing the dichroic dye is employed. Specifically, iodine or a dichroic dye is used as the dichroic dye. In addition, it is preferable that the polyvinyl alcohol-type resin film performs the immersion process to water before a dyeing process.

When iodine is used as the dichroic dye, a method of dyeing a polyvinyl alcohol-based resin film in an aqueous solution containing iodine and potassium iodide is usually employed. The iodine content in this aqueous solution is usually about 0.01 to 1 part by weight per 100 parts by weight of water. Further, the content of potassium iodide is usually about 0.5 to 20 parts by weight per 100 parts by weight of water. The temperature of the aqueous solution used for dyeing is usually about 20 to 40 ° C.
The immersion time (dyeing time) in this aqueous solution is usually about 20 to 1,800 seconds.

On the other hand, when a dichroic dye is used as the dichroic dye, a method of immersing and dyeing a polyvinyl alcohol-based resin film in an aqueous solution containing a water-soluble dichroic dye is usually employed. The content of the dichroic dye in this aqueous solution is usually about 1 × 10 ⁻⁴ to 10 parts by weight per 100 parts by weight of water, and preferably about 1 × 10 ⁻³ to 1 part by weight. This aqueous solution may contain an inorganic salt such as sodium sulfate as a dyeing assistant. The temperature of the aqueous dichroic dye solution used for dyeing is usually about 20 to 80 ° C. Further, the immersion time (dyeing time) in this aqueous solution is usually about 10 to 1,800 seconds.

The boric acid treatment after dyeing with a dichroic dye can usually be performed by immersing the dyed polyvinyl alcohol resin film in a boric acid-containing aqueous solution.

The amount of boric acid in the boric acid-containing aqueous solution is usually about 2 to 15 parts by weight per 100 parts by weight of water, and preferably 5 to 12 parts by weight. When iodine is used as the dichroic dye, the boric acid-containing aqueous solution preferably contains potassium iodide. The amount of potassium iodide in the boric acid-containing aqueous solution is usually about 0.1 to 15 parts by weight and preferably about 5 to 12 parts by weight per 100 parts by weight of water. The immersion time in the boric acid-containing aqueous solution is usually about 60 to 1,200 seconds, preferably about 150 to 600 seconds, and more preferably about 200 to 400 seconds. The temperature of the boric acid-containing aqueous solution is usually 50 ° C. or higher, preferably 50 to 85 ° C., more preferably 60 to 80 ° C.

The polyvinyl alcohol resin film after the boric acid treatment is usually washed with water. The water washing treatment can be performed, for example, by immersing a boric acid-treated polyvinyl alcohol resin film in water. The temperature of water in the water washing treatment is usually about 5 to 40 ° C. The immersion time is usually about 1 to 120 seconds.

After washing with water, a drying process is performed to obtain a polarizing film. The drying process can be performed using a hot air dryer or a far infrared heater. The temperature for the drying treatment is usually about 30 to 100 ° C., preferably 50 to 80 ° C. The drying treatment time is usually about 60 to 600 seconds, and preferably 120 to 600 seconds.

The moisture content of the polarizing film is reduced to a practical level by the drying treatment. The water content is usually 5 to 20% by weight, preferably 8 to 15% by weight. When the moisture content is less than 5% by weight, the flexibility of the polarizing film is lost, and the polarizing film may be damaged or broken after drying. Moreover, when a moisture content exceeds 20 weight%, the thermal stability of a polarizing film may be inferior.

Further, the stretching, dyeing, boric acid treatment, water washing step, and drying step of the polyvinyl alcohol resin film in the production process of the polarizing film may be performed in accordance with, for example, the method described in JP2012-159778A. . In the method described in this document, a polyvinyl alcohol resin layer to be a polarizer is formed by coating a polyvinyl alcohol resin on a base film.

The thickness of the polarizing film is preferably 15 μm or less, more preferably 3 to 10 μm.

Moreover, the said polarizing film can be used as a single-sided protective polarizing plate which has a protective film only on the single side | surface of the said polarizing film.

(Protective film)
As a material for forming a protective film provided on one side or both sides of the polarizing film, a material excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy and the like is preferable. For example, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, cellulose resins such as diacetyl cellulose and triacetyl cellulose, acrylic resins such as polymethyl methacrylate, styrene such as polystyrene and acrylonitrile / styrene copolymer (AS resin) Resin, polycarbonate resin and the like.
In addition, polyethylene, polypropylene, polyolefins having a cyclo or norbornene structure, polyolefin resins such as ethylene / propylene copolymers, vinyl chloride resins, amide resins such as nylon and aromatic polyamide, imide resins, sulfone resins , Polyether sulfone resin, polyether ether ketone resin, polyphenylene sulfide resin, vinyl alcohol resin, vinylidene chloride resin, vinyl butyral resin, arylate resin, polyoxymethylene resin, epoxy resin, or Examples of resins that form the protective film include blends of the resins. The protective film can also be formed as a cured layer of an acrylic, urethane, acrylic urethane, epoxy, silicone, or other thermosetting or ultraviolet curable resin. When providing a protective film on both sides of a polarizing film, the protective film which consists of the same resin material may be used by the front and back, and the protective film which consists of a different resin material etc. may be used.

The thickness of the protective film can be determined as appropriate, but is generally about 1 to 500 μm from the viewpoints of workability such as strength and handleability, and thin film properties.

The polarizing film and the protective film are usually laminated via an aqueous adhesive or the like. Examples of the water-based adhesive include an isocyanate-based adhesive, a polyvinyl alcohol-based adhesive, a gelatin-based adhesive, a vinyl-based latex, a water-based polyurethane, and a water-based polyester. In addition to the above, examples of the adhesive between the polarizing film and the protective film include an ultraviolet curable adhesive and an electron beam curable adhesive. The electron beam curable polarizing film adhesive exhibits suitable adhesion to the various protective films. The protective film is preferably subjected to saponification treatment, corona treatment, plasma treatment, and the like prior to bonding with the polarizing film.

The surface of the protective film to which the polarizing film is not adhered may be subjected to a treatment for the purpose of a hard coat layer, an antireflection treatment, an antistatic layer, an antisticking layer, or diffusion or antiglare.

It is also useful to laminate a retardation film on the polarizing plate. For example, the functionality of a circularly polarizing plate can be provided by laminating a retardation film of λ / 4 plate. In such a case, the protective film may have a retardation film function, or a retardation film may be laminated on a polarizing plate on which a double-sided protective film of a polarizing film is laminated.

The retardation film of the λ / 4 plate is not particularly limited, and a known film can be used. For example, a film made of a liquid crystal compound described in JP 2014-123134 A or JP 2015-187717 A or a stretched film described in Japanese Patent No. 3325560 can be used.

(Composite polarizing plate)
The composite polarizing plate of this invention is the structure which laminated | stacked the said polarizing film or the said polarizing plate, and the said laminated body.

As the composite polarizing plate, the polarizing film or the polarizing plate and the laminate are prepared at a temperature of 40 ° C. and a response humidity of 92% R.D. H. It is possible to laminate the adhesive layer with the adhesive layer having a moisture permeability of 100 g / (m ² · day) or less. Temperature 40 ° C, response humidity 92% H. As the pressure-sensitive adhesive layer having a moisture permeability of 100 g / (m ² · day) or less, the one provided in the polarizing plate or the one provided in the laminate may be used.

In addition, the composite polarizing plate of the present invention may include an intervening layer such as an adhesive layer, a pressure-sensitive adhesive layer, and an undercoat layer (primer layer) other than those described above, and an easily adhesive layer. For example, the polarizing film or the polarizing plate and the laminate are heated at a temperature of 40 ° C. and a relative humidity of 92% R.D. H. It may be laminated through an adhesive layer other than the adhesive layer having a moisture permeability of 100 g / (m ² · day) or less. Examples of the adhesive layer other than the adhesive layer include a temperature of 40 ° C. and a relative humidity of 92% R.D. H. In which the water vapor transmission rate exceeds 100 g / (m ² · day). Examples of the adhesive layer other than the adhesive layer include an acrylic pressure-sensitive adhesive.

Moreover, the composite polarizing plate of the present invention can be provided with a functional layer. Providing the functional layer is preferable because generation of defects such as through cracks and nano slits generated in the polarizing film can be suppressed. The functional layer can be formed from various forming materials. The functional layer can be formed, for example, by applying a resin material to the polarizing film.

Examples of the resin material forming the functional layer include polyester resins, polyether resins, polycarbonate resins, polyurethane resins, silicone resins, polyamide resins, polyimide resins, PVA resins, acrylic resins, and the like. Can be mentioned. These resin materials can be used alone or in combination of two or more, but among these, one or more selected from the group consisting of polyurethane-based resins and polyvinyl alcohol (PVA) -based resins are preferable, PVA resin is more preferable. The form of the resin may be either water-based or solvent-based. The resin is preferably a water-based resin, and is preferably a PVA-based resin. As the water-based resin, an acrylic resin aqueous solution or a urethane resin aqueous solution can be used.

If the functional layer becomes too thick, the optical reliability and water resistance are lowered. Therefore, the thickness of the functional layer is preferably 15 μm or less, more preferably 10 μm or less, further preferably 8 μm or less, and 6 μm or less. Is more preferably 5 μm or less, and particularly preferably 3 μm or less. On the other hand, the thickness of the functional layer is preferably 0.2 μm or more, more preferably 0.5 μm or more, and further preferably 0.7 μm or more. Since the generation of cracks can be suppressed by the functional layer having the thickness, it is preferable.

Also, in order to laminate the composite polarizing plate with other members, an adhesive layer can be formed on one side or both sides of the composite polarizing plate. For example, the pressure-sensitive adhesive layer can be formed on the opposite side of the transparent conductive layer side with respect to the polarizing film in the composite polarizing plate.

The pressure-sensitive adhesive layer to be used is not particularly limited, and a known layer can be used.
This pressure-sensitive adhesive layer has a temperature of 40 ° C. and a relative humidity of 92% R.D. H. Moisture permeability may be 100g ^/ (m 2 · day) or less of the adhesive in said different from the adhesive, the moisture permeability may be 100g ^/ (m 2 · day) than the pressure-sensitive adhesive .

Examples of the pressure-sensitive adhesive different from the pressure-sensitive adhesive include acrylic polymer, silicone polymer, polyester, polyurethane, polyamide, polyvinyl ether, vinyl acetate / vinyl chloride copolymer, modified polyolefin, epoxy-based, fluorine-based, natural rubber, and synthetic rubber. What uses rubber-type polymers, such as rubber | gum, as a base polymer can be selected suitably, and can be used. As the pressure-sensitive adhesive, those having excellent optical transparency, moderate wettability, cohesiveness and adhesive pressure-sensitive adhesive properties, and excellent weather resistance and heat resistance are particularly preferable.

The pressure-sensitive adhesive layer is not particularly limited as long as it has excellent optical transparency and exhibits pressure-sensitive adhesive properties such as appropriate wettability, cohesiveness, and adhesiveness, but is preferably excellent in durability and the like. Specific examples of the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer include a pressure-sensitive adhesive made of an acrylic resin (also referred to as an acrylic pressure-sensitive adhesive).

The pressure-sensitive adhesive layer formed from the acrylic pressure-sensitive adhesive is not particularly limited, but (butyl) (meth) acrylate, ethyl (meth) acrylate, isooctyl (meth) acrylate, and (meth) acrylic acid (Meth) acrylic ester resins such as 2-ethylhexyl and copolymer resins using two or more of these (meth) acrylic esters are preferably used. These resins are copolymerized with polar monomers. Examples of polar monomers include (meth) acrylic acid, 2-hydroxypropyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, (meth) acrylamide, and 2-N, N-dimethylaminoethyl (meth). Examples thereof include monomers having a polar functional group such as carboxyl group, hydroxyl group, amide group, amino group, and epoxy group, such as acrylate and glycidyl (meth) acrylate. Moreover, a crosslinking agent is normally mix | blended with the adhesive with acrylic resin.

In addition to this, various additives may be blended in the adhesive. Suitable additives include silane coupling agents and antistatic agents. A silane coupling agent is effective in increasing the adhesive strength with glass. Antistatic agents are effective in reducing or preventing the generation of static electricity. That is, when sticking the polarizing plate to the liquid crystal cell through the pressure-sensitive adhesive layer, the surface protective film (separator) that has been temporarily protected by covering the pressure-sensitive adhesive layer is peeled off and then attached to the liquid crystal cell. The static electricity generated when the surface protective film is peeled off causes alignment failure in the liquid crystal in the cell, which may cause display failure of the liquid crystal display device. In order to reduce or prevent the generation of such static electricity, the addition of an antistatic agent is effective.

The thickness of at least one pressure-sensitive adhesive is preferably 3 to 50 μm. More preferably, it is 3 to 30 μm.

When the adhesive layer is made conductive, its resistance value may be selected as appropriate, but it is preferably in the range of 1 × 10 ⁹ to 1 × 10 ¹¹ Ω / □, for example.

Examples of other members that can be further laminated on the laminate of the present invention include a front plate such as a cover glass and a window film, and a display element such as a liquid crystal display element and an organic EL display element.

<Image display device>
The image display device of the present invention has the laminate or composite polarizing plate of the present invention.

The composite polarizing plate of the present invention is applied to a known one regardless of the type as an image display device.
For example, the composite polarizing plate of the present invention can be suitably used for a liquid crystal display device mounted with a touch panel or an organic EL display device.

The image display device may be a flexible image display device. The flexible image display device includes a laminate for a flexible image display device and an organic EL display panel, and the flexible image display device laminate is arranged on the viewing side with respect to the organic EL display panel, and is configured to be bendable. Yes. As a laminate for a flexible image display device, it may contain a window, a circularly polarizing plate, a touch panel provided with the laminate of the present invention, and their order of lamination is arbitrary. It is preferable to laminate | stack in order of the touchscreen provided with the laminated body of this invention, or a window, the touchscreen provided with the laminated body of this invention, and a circularly-polarizing plate. Moreover, as a laminated body for flexible image display apparatuses, what contains a window and the composite polarizing plate of this invention can be illustrated. The presence of a circularly polarizing plate on the viewing side of the touch panel is preferable because the touch panel pattern is less visible and the visibility of the display image is improved. Each member can be laminated | stacked using an adhesive agent, an adhesive, etc. Moreover, the light-shielding pattern formed in at least one surface of any layer of a window, a circularly-polarizing plate, and a touchscreen can be comprised.

[Window]
The window is disposed on the visual recognition side of the flexible image display device, and plays a role of protecting other components from external impacts or environmental changes such as temperature and humidity. Conventionally, glass has been used as such a protective layer. However, a window in a flexible image display device is not rigid and hard like glass, and has flexible characteristics. The window is made of a flexible transparent substrate and may include a hard coat layer on at least one surface.

(Transparent substrate)
The transparent substrate has a visible light transmittance of 70% or more, preferably 80% or more. As the transparent substrate, any transparent polymer film can be used. Specifically, the transparent substrate is made of polyolefins such as cycloolefin derivatives having units of monomers including polyethylene, polypropylene, polymethylpentene, norbornene or cycloolefin, diacetylcellulose, triacetylcellulose, propionylcellulose and the like. (Modified) Celluloses, acrylics such as methyl methacrylate (co) polymers, polystyrenes such as styrene (co) polymers, acrylonitrile / butadiene / styrene copolymers, acrylonitrile / styrene copolymers, ethylene-acetic acid Vinyl copolymers, polyvinyl chlorides, polyvinylidene chlorides, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyarylate and other polyesters, nylon, etc. Even films formed of polymers such as lyamides, polyimides, polyamideimides, polyetherimides, polyethersulfones, polysulfones, polyvinyl alcohols, polyvinyl acetals, polyurethanes, epoxy resins, etc. Good. These polymers can be used alone or in admixture of two or more. Among the transparent substrates described above, a polyamide film, a polyamideimide film or a polyimide film, a polyester film, an olefin film, an acrylic film, and a cellulose film that are excellent in transparency and heat resistance are preferable. It is also preferable to disperse inorganic particles such as silica, organic fine particles, rubber particles and the like in the polymer film. In addition, colorants such as pigments and dyes, optical brighteners, dispersants, plasticizers, heat stabilizers, light stabilizers, infrared absorbers, ultraviolet absorbers, antistatic agents, antioxidants, lubricants, solvents, etc. You may contain the compounding agent of. The transparent substrate has a thickness of 5 to 200 μm, preferably 20 to 100 μm. The transparent substrate may be an unstretched film, a uniaxially stretched film, or a biaxially stretched film.

(Hard coat)
The window may be provided with a hard coat layer on at least one surface of the transparent substrate. The thickness of the hard coat layer is not particularly limited, and may be, for example, 2 to 100 μm.
When the thickness of the hard coat layer is less than 2 μm, it is difficult to ensure sufficient impact resistance and scratch resistance, and when it exceeds 100 μm, the bending resistance is lowered and the problem of curling due to curing shrinkage occurs. There is.

The hard coat layer can be a hardened layer of a hard coat composition containing a reactive material that forms a crosslinked structure by irradiation with active energy rays or thermal energy. Examples of the active energy rays include visible light, ultraviolet rays, infrared rays, X-rays, α rays, β rays, γ rays, and electron beams. Ultraviolet light is particularly preferred. The hard coat composition contains at least one polymer of a radical polymerizable compound and a cationic polymerizable compound. The hard coat composition may further contain a polymerization initiator. The hard coat composition may further include one or more selected from the group consisting of a solvent and an additive. Examples of the additive include inorganic particles, leveling agents, stabilizers, surfactants, antistatic agents, lubricants, antifouling agents and the like.

[Adhesive layer]
Each layer (window, circularly polarizing plate, touch panel) forming the laminate for a flexible image display device and a film member (linear polarizing plate, λ / 4 retardation plate, etc.) constituting each layer can be laminated with an adhesive. Adhesives include water based adhesives, organic solvent based, solventless based adhesives, solid adhesives, solvent volatilizing adhesives, moisture curable adhesives, heat curable adhesives, anaerobic curable adhesives, and active energy ray curable adhesives. Commonly used materials such as an adhesive, a curing agent mixed adhesive, a hot-melt adhesive, a pressure-sensitive adhesive (adhesive), and a rewet adhesive can be used. Of these, water-based solvent volatile adhesives, active energy ray-curable adhesives, and pressure-sensitive adhesives are often used. The thickness of the adhesive layer can be appropriately adjusted according to the required adhesive strength and the like, and is 0.01 μm to 500 μm, preferably 0.1 μm to 300 μm. When the laminate for a flexible image display device includes a plurality of adhesive layers, the thickness and type of each may be the same or different.

[Shading pattern]
The light shielding pattern can be applied as at least a part of a bezel or a housing of a flexible image display device. The light shielding pattern shields the wiring arranged at the edge portion of the flexible image display device, and makes it difficult to see. The light shielding pattern may be in the form of a single layer or multiple layers. The color of the light shielding pattern is not particularly limited, and examples thereof include black, white, and metal color. The light shielding pattern can be formed of a pigment and a polymer such as an acrylic resin, an ester resin, an epoxy resin, polyurethane, or silicone. The light shielding pattern can be formed by various methods such as printing, lithography, and inkjet. The thickness of the light shielding pattern may be 1 μm to 100 μm, preferably 2 μm to 50 μm. It is also preferable to give a shape such as an inclination in the thickness direction of the light shielding pattern.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. In the examples, the parts and% representing the content or amount used are based on weight unless otherwise specified. In addition, each physical property in the following examples was measured by the following method.

(1) Measurement of thickness:
Measurement was performed using a digital micrometer “MH-15M” manufactured by Nikon Corporation.

(2) Measurement of moisture permeability of pressure-sensitive adhesive layer On the pressure-sensitive adhesive surface of the pressure-sensitive adhesive sheet (pressure-sensitive adhesive layer thickness: 50 μm) used in the examples, a triacetyl cellulose film (TAC film, thickness: 25 μm, manufactured by Konica Minolta Co., Ltd.) ). Thereafter, the release film of the pressure-sensitive adhesive sheet was peeled off to obtain a measurement sample. Next, using this measurement sample, moisture permeability (water vapor permeability) was measured by the moisture permeability test method (cup method, conforming to JIS Z 0208) under the following conditions.
Measurement temperature: 40 ° C
Relative humidity: 92% R.D. H.
Measurement time: A constant temperature and humidity chamber was used for measurement for 24 hours.

[Production Example 1] Production of Polarizing Film A 30 μm-thick polyvinyl alcohol film (average polymerization degree of about 2400, saponification degree of 99.9 mol% or more) is uniaxially stretched by about 4 times by dry stretching, and the tension state is maintained. The sample was immersed in pure water at 40 ° C. for 40 seconds, and then immersed in an aqueous solution having an iodine / potassium iodide / water weight ratio of 0.052 / 5.7 / 100 at 28 ° C. for 30 seconds to perform a dyeing treatment. It was. Thereafter, it was immersed in an aqueous solution having a weight ratio of potassium iodide / boric acid / water of 11.0 / 6.2 / 100 at 70 ° C. for 120 seconds. Subsequently, after washing with pure water at 8 ° C. for 15 seconds, the film is dried at 60 ° C. for 50 seconds and then at 75 ° C. for 20 seconds while being held at a tension of 300 N, and iodine is adsorbed and oriented on the polyvinyl alcohol film. A polarizing film having a thickness of 12 μm was obtained.

[Production Example 2] Production of rubber-based pressure-sensitive adhesive 1 100 parts by weight of polyisobutylene (trade name: OPPANOL B80, Mw: about 750,000, manufactured by BASF) and tricyclodecane dimethanol dimer as a polyfunctional radical polymerizable compound 10 parts by weight of acrylate (trade name: NK ester A-DCP, bifunctional acrylate, molecular weight: 304, manufactured by Shin-Nakamura Chemical Co., Ltd.), benzophenone (Wako Pure Chemical Industries, Ltd.), a hydrogen abstraction type photopolymerization initiator (Manufactured) 0.5 parts of toluene and 10 parts by weight of fully hydrogenated terpene phenol was adjusted to a solid content of 15% by weight to prepare a rubber adhesive 1 (solution). did.

[Production Example 3] Production of rubber-based pressure-sensitive adhesive sheet 1 A 38-μm thick polyester film (trade name: Diafoil MRF, Mitsubishi) obtained by peeling one side of the rubber-based pressure-sensitive adhesive 1 (solution) obtained in Production Example 2 with silicone. A coating layer was formed by applying to the release-treated surface of Resin Co., Ltd. Subsequently, the coating layer was dried at 80 ° C. for 3 minutes to form a pressure-sensitive adhesive layer, and a pressure-sensitive adhesive sheet having a thickness of 20 μm was produced. Also, the adhesive surface of the adhesive sheet is a 38 μm thick polyester film (trade name: Diafoil MRF, manufactured by Mitsubishi Resin Co., Ltd.) having one surface peeled off with silicone so that the peeling treatment surface and the pressure-sensitive adhesive layer are in contact with each other. Pasted together. The polyester film coated on both surfaces of the pressure-sensitive adhesive layer functions as a release film (separator).

One separator was peeled off, and ultraviolet rays were irradiated at room temperature from the side where the separator was peeled off to obtain a pressure-sensitive adhesive sheet comprising a rubber-based pressure-sensitive adhesive layer 1 / separator. In the UVA region, the UV irradiation was a light amount of 1000 mJ / cm ² . When the moisture permeability was measured using a pressure-sensitive adhesive sheet having a 50 μm-thick pressure-sensitive adhesive layer prepared by separately adjusting the coating thickness, the pressure-sensitive adhesive layer had a layer humidity of 10 g / (m ² · day). .

[Production Example 4] Production of olefin-based pressure-sensitive adhesive sheet As a pressure-sensitive adhesive layer forming material, an amorphous propylene- (1-butene) copolymer polymerized by a metallocene catalyst (trade name “Tufselen H5002” manufactured by Sumitomo Chemical Co., Ltd.): Propylene-derived structural unit 90 mol% / 1-butene-derived structural unit 10 mol%, Mw = 230,000, Mw / Mn = 1.8) and a crystalline polypropylene resin polymerized by a metallocene catalyst (Nippon Polypropylene) 40 parts by product (trade name “WINTEC WFX4”, manufactured by Co., Ltd.) were used. 100 parts of the pressure-sensitive adhesive layer forming material was put into an extruder and subjected to T-die melt extrusion (extrusion temperature 180 ° C.) to obtain a pressure-sensitive adhesive layer having a thickness of 20 μm. Moreover, the adhesive surface of the adhesive layer is a 38 μm thick polyester film (trade name: Diafoil MRF, manufactured by Mitsubishi Resin Co., Ltd.) having one surface peeled off with silicone, and the release surface and the adhesive layer are in contact with each other. Were pasted together. The polyester film coated on both surfaces of the pressure-sensitive adhesive layer functions as a release film (separator).
The moisture permeability of the pressure-sensitive adhesive layer was 12 g / (m ² · day) when a pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer having a thickness of 50 μm prepared by separately adjusting the extrusion conditions was measured.

[Production Example 5] Production of rubber adhesive 2 Styrene-ethylene-propylene-styrene block copolymer (SEPS, trade name: SEPTON 2063, styrene content: 13%, manufactured by Kuraray Co., Ltd.) as a styrene thermoplastic elastomer ) 100 parts by weight and hydrogenated terpene phenol (trade name: YS Polyster TH130, softening point: 130 ° C., hydroxyl value: 60, manufactured by Yasuhara Chemical Co., Ltd.) as a tackifier, petroleum-based tackifier (Trade name: Picolastic A5, vinyltoluene-based tackifier, softening point: 5 ° C., manufactured by Eastman Kodak Company) 61.7 parts, polybutene as a softening agent (trade name: HV-300, weight average molecular weight: 3000, JX Nippon Mining & Energy Co., Ltd.) 21.3 parts of a toluene solution containing 30% by weight solids Adjusted, to prepare a rubber-based pressure-sensitive adhesive 2 (solution).

[Production Example 6] Production of rubber-based pressure-sensitive adhesive sheet 2 A polyester film (trade name: Diafoil MRF, product name: Diafoil MRF, obtained by removing one side of the rubber-based pressure-sensitive adhesive 2 (solution) obtained in Production Example 5 with silicone. The coated layer was formed by coating on a release-treated surface of Mitsubishi Resin Co., Ltd. Subsequently, the coating layer was dried at 80 ° C. for 3 minutes to form a pressure-sensitive adhesive layer, and a pressure-sensitive adhesive sheet having a thickness of 20 μm was produced. Also, the adhesive surface of the adhesive sheet is a 38 μm thick polyester film (trade name: Diafoil MRF, manufactured by Mitsubishi Resin Co., Ltd.) having one surface peeled off with silicone so that the peeling treatment surface and the pressure-sensitive adhesive layer are in contact with each other. Pasted together. The polyester film coated on both surfaces of the pressure-sensitive adhesive layer functions as a release film (separator).

One separator was peeled off, and ultraviolet rays were irradiated at room temperature from the side where the separator was peeled off to obtain a pressure-sensitive adhesive sheet composed of rubber-based pressure-sensitive adhesive layer 2 / separator. In the UVA region, the UV irradiation was a light amount of 1000 mJ / cm ² . The moisture permeability of the pressure-sensitive adhesive layer was 40 g / (m ² · day) as measured using a pressure-sensitive adhesive sheet having a 50 μm-thick pressure-sensitive adhesive layer prepared by separately adjusting the coating thickness.

The following two types were prepared as transparent conductive layers.
Transparent conductive layer A: A non-alkali glass [trade name “Eagle XG”] substrate manufactured by Corning Inc. was prepared by forming an ITO layer having a thickness of 30 nm on the surface.
Transparent conductive layer B: A non-alkali glass [trade name “Eagle XG”] substrate manufactured by Corning Inc. was prepared by forming an aluminum layer having a thickness of 500 nm on the surface.

[Example 1]
(Production of laminate)
The rubber-based pressure-sensitive adhesive layer 1 produced in Production Example 3 was bonded to the surface of the transparent conductive layer A on which the ITO layer was formed to produce a laminate.

(Production of composite polarizing plate)
While applying a polyvinyl alcohol-based adhesive so that the thickness of the adhesive layer is 0.1 μm on both surfaces of the polarizing film obtained in Production Example 1, a protective film (triacetylcellulose (TAC) film (trade name) : KC2UAW, thickness: 25 μm, manufactured by Konica Minolta Co., Ltd.), followed by drying at 80 ° C. for 2 minutes to produce a polarizing plate with a double-sided protective film.

The obtained laminate and a polarizing plate with a double-sided protective film were bonded together through the rubber-based pressure-sensitive adhesive layer 1 included in the laminate to obtain a composite polarizing plate.

[Evaluation of ITO corrosiveness of composite polarizing plate]
The surface resistance of the ITO layer of the transparent conductive layer A was measured using a low resistivity meter (trade name “Loresta-AX” manufactured by Mitsubishi Chemical Analytech Co., Ltd.) at a temperature of 23 ° C. and a relative humidity of 50% R.D. H. Measured under the atmosphere of

As an evaluation method, first, the surface resistance value (surface resistance value before test) of the ITO layer before the rubber-based pressure-sensitive adhesive 1 was bonded was measured. Next, the composite polarizing plate produced above was cut into a test piece having a size of 40 mm × 40 mm. The cut composite polarizing plate was heated to 60 ° C. and 90% relative humidity. H. In an oven for 72 hours, and then a temperature of 23 ° C. and a relative humidity of 50% R.D. H. Then, the polarizing plate and the adhesive were peeled off from the composite polarizing plate to expose the transparent conductive layer A.
Thus, the surface resistance value of the ITO layer after the test (surface resistance value after the test) was measured. The rate of change in resistance before and after the test was calculated by the following formula, and the ITO corrosivity was evaluated according to the following criteria. A smaller resistance change rate means that the ITO is not corroded.
Resistance change rate (%) = [(surface resistance value after test) − (surface resistance value before test)] / [surface resistance value before test] × 100

<Evaluation criteria for ITO corrosivity>
(Circle): It is a composite polarizing plate whose resistance change rate is less than 30%, and ITO corrosivity is favorable.
Δ: The rate of change in resistance is 30% or more and less than 100%, and the ITO corrosivity of the composite polarizing plate is poor.
X: The resistance change rate is 100% or more, and the ITO corrosiveness of the composite polarizing plate is extremely poor.

The result of ITO corrosivity evaluation was ○. Moreover, although corrosion of the ITO layer was visually confirmed, no cloudiness or pitting corrosion occurred on the surface of the ITO layer.

[Example 2]
A laminate and a composite polarizing plate were produced in the same manner as in Example 1 except that the adhesive in Example 1 was changed from the rubber adhesive 1 to the olefin adhesive in Production Example 4.

Next, the corrosive evaluation of the ITO layer was performed in the same manner as in Example 1. The result of ITO corrosivity evaluation was “good”. Moreover, when the corrosion of the ITO layer was visually confirmed, no cloudiness or pitting corrosion occurred on the surface of the ITO layer.

[Example 5]
A laminate and a composite polarizing plate were produced in the same manner except that the adhesive in Example 1 was changed from the rubber adhesive 1 to the rubber adhesive 2 in Production Example 6.

[Example 3]
A laminate and a composite polarizing plate were produced in the same manner as in Example 1 except that the transparent conductive layer A in Example 1 was changed to the transparent conductive layer B.

[Aluminum corrosivity evaluation of composite polarizing plate]
The surface resistance value of the surface of the aluminum layer of the transparent conductive layer B was determined using a high resistivity meter (trade name “HIRESTA-UP” MCP-HT450 manufactured by Mitsubishi Chemical Analytech Co., Ltd.) at a temperature of 23 ° C. and a relative humidity of 50. % R. H. Measured under the atmosphere of

As an evaluation method, first, the surface resistance value (surface resistance value before test) of the aluminum layer before the rubber-based pressure-sensitive adhesive 1 was bonded was measured. Next, the composite polarizing plate produced above was cut into a test piece having a size of 40 mm × 40 mm. The composite polarizing plate thus cut was subjected to a temperature of 80 ° C. and a relative humidity of 90% R.D. H. In an oven for 72 hours, and then a temperature of 23 ° C. and a relative humidity of 50% R.D. H. Under the atmosphere, the polarizing plate and the pressure-sensitive adhesive were peeled off from the composite polarizing plate to expose the transparent conductive layer B.
Thus, the surface resistance value of the aluminum layer after the test (surface resistance value after the test) was measured. The rate of change in resistance before and after the test was calculated according to the following formula, and was evaluated based on the standard below aluminum corrosivity.
A smaller resistance change rate means that the aluminum is not corroded.
Resistance change rate (%) = [(surface resistance value after test) − (surface resistance value before test)] / [surface resistance value before test] × 100

<Evaluation criteria for aluminum corrosion>
(Circle): It is a composite polarizing plate whose resistance change rate is less than 30%, and aluminum corrosivity is favorable.
(Triangle | delta): Resistance change rate is 30% or more and less than 100%, and the aluminum corrosivity of a composite polarizing plate is unsatisfactory.
X: The rate of change in resistance is 100% or more, and the aluminum corrosivity of the composite polarizing plate is extremely poor.

The result of aluminum corrosivity evaluation was “good”. Further, when the corrosion of the aluminum layer was visually confirmed, no cloudiness or pitting corrosion occurred on the surface of the aluminum layer.

[Example 4]
A laminate and a composite polarizing plate were produced in the same manner as in Example 3 except that the adhesive in Example 3 was changed from the rubber adhesive 1 to the olefin adhesive in Production Example 4.

Next, the corrosive evaluation of the aluminum layer was performed in the same manner as in Example 3. The result of aluminum corrosivity evaluation was “good”. Moreover, although corrosion of the aluminum layer was confirmed visually, no cloudiness or pitting corrosion occurred on the surface of the aluminum layer.

[Example 6]
A laminate and a composite polarizing plate were produced in the same manner as in Example 3 except that the pressure-sensitive adhesive in Example 3 was changed from the rubber-based pressure-sensitive adhesive 1 to the rubber-based pressure-sensitive adhesive 2 in Production Example 6.

According to the present invention, a laminate having a small resistance change rate of the transparent conductive layer can be provided even in a high-temperature and high-humidity environment, which is useful. Furthermore, the present invention is useful because it can provide a composite polarizing plate and an image display device in which the resistance change of the transparent conductive layer is small even under a high temperature and high humidity environment.

Claims

Transparent conductive layer, temperature 40 ° C., relative humidity 92% R.D. H. A laminate having a moisture permeability of 100 g / (m 2 · day) or less and being laminated in contact with each other.
The laminate according to claim 1, wherein the adhesive layer is a pressure-sensitive adhesive layer formed from a rubber-based pressure-sensitive adhesive composition containing polyisobutylene and a hydrogen abstraction type photopolymerization initiator.
The laminate according to claim 1, wherein the adhesive layer is a pressure-sensitive adhesive layer containing a polyolefin resin.
The laminate according to claim 3, wherein the polyolefin resin includes an amorphous polypropylene resin.
A composite polarizing plate comprising a polarizing film and the laminate according to any one of claims 1 to 4.
The composite polarizing plate according to claim 5, wherein the polarizing film has a thickness of 15 μm or less.
An image display device comprising the laminate according to any one of claims 1 to 4 or the composite polarizing plate according to claims 5 to 6.