JP2022064896A - Laminate for flexible image display device and flexible image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate for a flexible image display device, which shows excellent flexibility and adhesiveness without causing peeling or breakage even when subjected to repeated bending, by using an optical film including at least a polarizing film and a plurality of specific adhesive layers, and to provide a flexible image display device in which the laminate for a flexible image display device is disposed.

SOLUTION: The laminate for a flexible image display device comprises a plurality of adhesive layers and an optical film including at least a polarizing film. The polarizing film has a thickness of 20 μm or less; and among the plurality of adhesive layers, a storage modulus G' at 25°C of the outermost adhesive layer on a convex side when the laminate is bent is substantially equal to or smaller than the storage modulus G' of other adhesive layers at 25°C.

SELECTED DRAWING: Figure 3

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to an optical film including at least a polarizing film, a laminate for a flexible image display device including a plurality of specific adhesive layers, and a flexible image display device in which the laminate for the flexible image display device is arranged. ..

As an organic EL display device integrated with a touch sensor, as shown in FIG. 1, an optical laminate 20 is provided on the visual side of the organic EL display panel 10, and a touch panel 30 is provided on the visual side of the optical laminate 20. ing. The optical laminate 20 includes a polarizing film 1 having protective films 2-1 and 2-2 bonded to both sides thereof and a retardation film 3, and the polarizing film 1 is provided on the visible side of the retardation film 3. Further, in the touch panel 30, transparent conductive films 4-1 and 4-2 having a structure in which a base film 5-1 and 5-2 and transparent conductive layers 6-1 and 6-2 are laminated are interposed via a spacer 7. It has an arranged structure (see, for example, Patent Document 1).

Further, it is expected to realize a foldable organic EL display device having more excellent portability.

Japanese Unexamined Patent Publication No. 2014-157745

However, the conventional organic EL display device as shown in Patent Document 1 is not designed with bending in mind. If a plastic film is used as the base material of the organic EL display panel, the organic EL display panel can be given flexibility. Further, even when a plastic film is used for the touch panel and incorporated into the organic EL display panel, the organic EL display panel can be provided with flexibility. However, there is a problem that the optical film including the conventional polarizing film laminated on the organic EL display panel hinders the flexibility of the organic EL display device.

Therefore, in the present invention, by using an optical film including at least a polarizing film and a plurality of specific pressure-sensitive adhesive layers, there is no peeling or breakage even with repeated bending, and the bending resistance and adhesion are excellent. It is an object of the present invention to provide a laminated body for a flexible image display device and a flexible image display device in which the laminated body for the flexible image display device is arranged.

The laminate for a flexible image display device of the present invention is a laminate for a flexible image display device including a plurality of pressure-sensitive adhesive layers and an optical film containing at least a polarizing film, and the thickness of the polarizing film is 20 μm or less. Of the plurality of pressure-sensitive adhesive layers, the storage elastic modulus G'at 25 ° C. of the outermost pressure-sensitive adhesive layer on the convex side when the laminate is bent is stored at 25 ° C. of the other pressure-sensitive adhesive layer. It is characterized in that it is substantially the same as or smaller than the elastic modulus G'.

In the laminated body for a flexible image display device of the present invention, the optical film has the polarizing film, the protective film of the transparent resin material on the first surface of the polarizing film, and the first surface of the polarizing film. Is preferably an optical laminate comprising a retardation film having different second surfaces.

In the laminated body for a flexible image display device of the present invention, the first pressure-sensitive adhesive layer is arranged on the side opposite to the surface in contact with the polarizing film with respect to the protective film among the plurality of pressure-sensitive adhesive layers. Is preferable.

In the laminated body for a flexible image display device of the present invention, a second pressure-sensitive adhesive layer is arranged on the side opposite to the surface in contact with the polarizing film with respect to the retardation film among the plurality of pressure-sensitive adhesive layers. It is preferable that it is.

In the laminated body for a flexible image display device of the present invention, a transparent conductive layer constituting a touch sensor is arranged on the side opposite to the surface in contact with the retardation film with respect to the second pressure-sensitive adhesive layer. Is preferable.

In the laminated body for a flexible image display device of the present invention, the third pressure-sensitive adhesive layer is arranged on the side opposite to the surface in contact with the second pressure-sensitive adhesive layer with respect to the transparent conductive layer constituting the touch sensor. It is preferable that it is.

In the laminated body for a flexible image display device of the present invention, the transparent conductive layer constituting the touch sensor is arranged on the side opposite to the surface in contact with the protective film with respect to the first pressure-sensitive adhesive layer. Is preferable.

In the laminated body for a flexible image display device of the present invention, among the plurality of pressure-sensitive adhesive layers, the transparent conductive layer constituting the touch sensor is located on the side opposite to the surface in contact with the first pressure-sensitive adhesive layer. , It is preferable that a third pressure-sensitive adhesive layer is arranged.

In the laminated body for a flexible image display device of the present invention, it is preferable that the plurality of pressure-sensitive adhesive layers are formed from the same pressure-sensitive adhesive composition.

The flexible image display device of the present invention includes the flexible image display device laminate and the organic EL display panel, and the flexible image display device stack is arranged on the visual side with respect to the organic EL display panel. It is preferable to be done.

In the flexible image display device of the present invention, it is preferable that the window is arranged on the visual recognition side with respect to the laminated body for the flexible image display device.

According to the present invention, by using an optical film including at least a polarizing film and a plurality of specific pressure-sensitive adhesive layers, there is no peeling or breakage even with repeated bending, and excellent bending resistance and adhesion are obtained. It is possible to obtain a laminated body for a flexible image display device, and further, it is possible to obtain a flexible image display device in which the laminated body for the flexible image display device is arranged, which is useful.

Hereinafter, embodiments of an optical film, a laminate for a flexible image display device, and a flexible image display device according to the present invention will be described in detail with reference to drawings and the like.

It is sectional drawing which shows the conventional organic EL display device. It is sectional drawing which shows the flexible image display apparatus by one Embodiment of this invention. It is sectional drawing which shows the flexible image display apparatus by another Embodiment of this invention. It is sectional drawing which shows the flexible image display apparatus by another Embodiment of this invention. It is a figure which shows the measuring method of the fold resistance. It is sectional drawing which shows the evaluation sample used in an Example (configuration A). It is sectional drawing which shows the evaluation sample used in an Example (configuration B). It is a figure which shows the manufacturing method of the phase difference used in an Example. It is a figure which shows the manufacturing method of the phase difference used in an Example.

[Laminate for flexible image display device]
The laminate for a flexible image display device of the present invention is characterized by including a plurality of pressure-sensitive adhesive layers and an optical film.

[Optical film]
The laminate for a flexible image display device of the present invention is characterized by including an optical film including at least a polarizing film, and the optical film includes, for example, a protective film formed of, for example, a transparent resin material in addition to the polarizing film. And those including films such as retardation films.
Further, in the present invention, as the optical film, the polarizing film, the protective film of the transparent resin material on the first surface of the polarizing film, and the second surface different from the first surface of the polarizing film. The structure including the retardation film provided in the above is referred to as an optical laminate. The optical film does not include a plurality of pressure-sensitive adhesive layers such as the first pressure-sensitive adhesive layer described later.

The thickness of the optical film is preferably 92 μm or less, more preferably 60 μm or less, and further preferably 10 to 50 μm. If it is within the above range, it is a preferable embodiment without inhibiting bending.

The polarizing film may have a protective film bonded to at least one side by an adhesive (layer) as long as the characteristics of the present invention are not impaired (not shown in the drawings). An adhesive can be used for the bonding treatment between the polarizing film and the protective film. Examples of the adhesive include isocyanate-based adhesives, polyvinyl alcohol-based adhesives, gelatin-based adhesives, vinyl-based latex-based adhesives, and water-based polyesters. The adhesive is usually used as an adhesive consisting of an aqueous solution, and usually contains 0.5 to 60% by weight of a solid content. In addition to the above, examples of the adhesive between the polarizing film and the protective film include an ultraviolet curable adhesive, an electron beam curable adhesive, and the like. The adhesive for an electron beam curable polarizing film exhibits suitable adhesiveness to the above-mentioned various protective films. Further, the adhesive used in the present invention may contain a metal compound filler. In the present invention, a polarizing film (polarizing plate) in which a polarizing film and a protective film are bonded together with an adhesive (layer) may be referred to.

<Polarizing film>
The polarizing film (also referred to as a polarizing element) contained in the optical film of the present invention is polyvinyl alcohol (PVA) in which iodine is oriented, which is stretched by a stretching step such as aerial stretching (dry stretching) or boric acid water stretching step. A system resin can be used.

As a method for producing a polarizing film, typically, as described in Japanese Patent Application Laid-Open No. 2004-341515, a production method including a step of dyeing a single layer of a PVA-based resin and a step of stretching (single-layer stretching method). ). Further, JP-A No. 51-06644, JP-A-2000-338329, JP-A-2001-343521, International Publication No. 2010/100917, JP-A-2012-073563, JP-A-2011-2816. A manufacturing method including a step of stretching a PVA-based resin layer and a resin base material for stretching in a laminated state and a step of dyeing, as described in 1. With this manufacturing method, even if the PVA-based resin layer is thin, it can be stretched without any trouble such as breakage due to stretching because it is supported by the stretching resin base material.

The manufacturing method including the step of stretching in the state of the laminated body and the step of dyeing is as described in JP-A-51-069644, JP-A-2000-338329, and JP-A-2001-343521 described above. There is an aerial stretching (dry stretching) method. Then, the step of stretching in a boric acid aqueous solution as described in International Publication No. 2010/100917 and Japanese Patent Application Laid-Open No. 2012-07563 is performed in that it can be stretched at a high magnification and the polarization performance can be improved. A production method including the above is preferable, and a production method including a step of performing auxiliary stretching in the air before stretching in an aqueous boric acid solution (two-stage stretching method) is particularly preferable. Further, as described in JP-A-2011-2816, a manufacturing method in which a PVA-based resin layer and a stretching resin base material are stretched in a laminated state, the PVA-based resin layer is excessively dyed, and then decolorized. (Excessive staining and decolorization method) is also preferable. The polarizing film contained in the optical film of the present invention is made of a polyvinyl alcohol-based resin in which iodine is oriented as described above, and is a polarizing film stretched in a two-step stretching step consisting of auxiliary stretching in the air and stretching in boric acid in water. can do. Further, the polarizing film is made of a polyvinyl alcohol-based resin in which iodine is oriented as described above, and the laminated body of the stretched PVA-based resin layer and the stretching resin base material is excessively dyed and then decolorized. It can be a produced polarizing film.

The thickness of the polarizing film is 20 μm or less, preferably 12 μm or less, more preferably 9 μm or less, still more preferably 1 to 8 μm, and particularly preferably 3 to 6 μm. If it is within the above range, it is a preferable embodiment without inhibiting bending.

<Phase difference film>
The optical film used in the present invention may include a retardation film, and the retardation film (also referred to as a retardation film) is obtained by stretching a polymer film or oriented and fixed a liquid crystal material. It is possible to use a modified product. As used herein, the retardation film refers to a film having birefringence in the in-plane and / or thickness direction.

As the retardation film, the antireflection retardation film (see JP-A-2012-133303 [0221], [0222], [0228]) and the viewing angle compensating phase difference film (Japanese Patent Laid-Open No. 2012-133303 [0225]). ], [0226]), tilt-oriented retardation film for viewing angle compensation (see Japanese Patent Application Laid-Open No. 2012-133303 [0227]) and the like.

The retardation film is not particularly limited as long as it has substantially the above-mentioned functions, for example, the retardation value, the arrangement angle, the three-dimensional birefringence, and whether it is a single layer or a multilayer, and is a known retardation film. Can be used.

The thickness of the retardation film is preferably 20 μm or less, more preferably 10 μm or less, still more preferably 1 to 9 μm, and particularly preferably 3 to 8 μm. If it is within the above range, it is a preferable embodiment without inhibiting bending.

<Protective film>
The optical film used in the present invention may include a protective film formed of a transparent resin material, and the protective film (also referred to as a transparent protective film) may be a cycloolefin resin such as a norbornene resin, polyethylene, or the like. Olefin-based resins such as polypropylene, polyester-based resins, (meth) acrylic-based resins, and the like can be used.

The thickness of the protective film is preferably 5 to 60 μm, more preferably 10 to 40 μm, still more preferably 10 to 30 μm, and a surface treatment layer such as an antiglare layer or an antireflection layer is appropriately provided. Can be done. If it is within the above range, it is a preferable embodiment without inhibiting bending.

[First adhesive layer]
Of the plurality of pressure-sensitive adhesive layers used in the laminate for a flexible image display device of the present invention, the first pressure-sensitive adhesive layer is arranged on the side opposite to the surface in contact with the polarizing film with respect to the protective film. Is preferable.

The pressure-sensitive adhesive layer constituting the first pressure-sensitive adhesive layer used in the laminate for a flexible image display device of the present invention is an acrylic pressure-sensitive adhesive, a rubber-based pressure-sensitive adhesive, a vinyl alkyl ether-based pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, or a polyester-based pressure-sensitive adhesive. Examples thereof include adhesives, polyamide-based adhesives, urethane-based adhesives, fluorine-based adhesives, epoxy-based adhesives, and polyether-based adhesives. The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer may be used alone or in combination of two or more. However, from the viewpoint of transparency, processability, durability, adhesion, bending resistance, etc., it is preferable to use the acrylic pressure-sensitive adhesive alone.

<(Meta) acrylic polymer>
When an acrylic pressure-sensitive adhesive is used as the pressure-sensitive adhesive composition, the (meth) acrylic containing a (meth) acrylic monomer having a linear or branched alkyl group having 1 to 24 carbon atoms as a monomer unit. It is preferable to contain a based polymer. By using the linear or branched (meth) acrylic monomer having an alkyl group having 1 to 24 carbon atoms, a pressure-sensitive adhesive layer having excellent flexibility can be obtained. The (meth) acrylic polymer in the present invention means an acrylic polymer and / or a methacrylic polymer, and the (meth) acrylate means an acrylate and / or a methacrylate.

Specific examples of the (meth) acrylic monomer having a linear or branched alkyl group having 1 to 24 carbon atoms constituting the main skeleton of the (meth) acrylic polymer include methyl (meth) acrylate and ethyl. (Meta) acrylate, n-butyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, isobutyl (meth) acrylate, n-pentyl (meth) acrylate, isopentyl (meth) acrylate, n -Hexyl (meth) acrylate, isohexyl (meth) acrylate, isoheptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl (meth) acrylate, Examples thereof include isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-dodecyl (meth) acrylate, n-tridecyl (meth) acrylate, and n-tetradecyl (meth) acrylate. Generally, a monomer having a low glass transition temperature (Tg) becomes a viscoelastic body even in a high velocity region at the time of bending. Therefore, from the viewpoint of flexibility, a linear or branched alkyl having 4 to 8 carbon atoms. A (meth) acrylic monomer having a group is preferable. As the (meth) acrylic monomer, one kind or two or more kinds can be used.

The linear or branched (meth) acrylic monomer having an alkyl group having 1 to 24 carbon atoms is the main component of all the monomers constituting the (meth) acrylic polymer. Here, the main component is 80 to 100% by weight of a (meth) acrylic monomer having a linear or branched alkyl group having 1 to 24 carbon atoms among all the monomers constituting the (meth) acrylic polymer. %, More preferably 90 to 100% by weight, even more preferably 92 to 99.9% by weight, and particularly preferably 94 to 99.9% by weight.

When an acrylic pressure-sensitive adhesive is used as the pressure-sensitive adhesive composition, it is preferable to contain a (meth) acrylic polymer containing a hydroxyl group-containing monomer having a reactive functional group as a monomer unit. By using the hydroxyl group-containing monomer, a pressure-sensitive adhesive layer having excellent adhesion and flexibility can be obtained. The hydroxyl group-containing monomer is a compound containing a hydroxyl group in its structure and containing a polymerizable unsaturated double bond such as a (meth) acryloyl group and a vinyl group.

Specific examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, and 8-hydroxy. Examples thereof include hydroxyalkyl (meth) acrylates such as octyl (meth) acrylates, 10-hydroxydecyl (meth) acrylates and 12-hydroxylauryl (meth) acrylates, and (4-hydroxymethylcyclohexyl) -methyl acrylates. Among the hydroxyl group-containing monomers, 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate are preferable from the viewpoint of durability and adhesion. As the hydroxyl group-containing monomer, one kind or two or more kinds can be used.

Further, as the monomer unit constituting the (meth) acrylic polymer, it is possible to contain a monomer such as a carboxyl group-containing monomer having a reactive functional group, an amino group-containing monomer, and an amide group-containing monomer. The use of these monomers is preferable from the viewpoint of adhesion in a moist heat environment.

When an acrylic pressure-sensitive adhesive is used as the pressure-sensitive adhesive composition, a (meth) acrylic polymer containing a carboxyl group-containing monomer having a reactive functional group can be contained as a monomer unit. By using the carboxyl group-containing monomer, a pressure-sensitive adhesive layer having excellent adhesion in a moist heat environment can be obtained. The carboxyl group-containing monomer is a compound containing a carboxyl group in its structure and containing a polymerizable unsaturated double bond such as a (meth) acryloyl group and a vinyl group.

Specific examples of the carboxyl group-containing monomer include (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid and the like.

When an acrylic pressure-sensitive adhesive is used as the pressure-sensitive adhesive composition, a (meth) acrylic polymer containing an amino group-containing monomer having a reactive functional group can be contained as a monomer unit. By using the amino group-containing monomer, a pressure-sensitive adhesive layer having excellent adhesion in a moist heat environment can be obtained. The amino group-containing monomer is a compound containing an amino group in its structure and containing a polymerizable unsaturated double bond such as a (meth) acryloyl group and a vinyl group.

Specific examples of the amino group-containing monomer include N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate and the like.

When an acrylic pressure-sensitive adhesive is used as the pressure-sensitive adhesive composition, a (meth) acrylic polymer containing an amide group-containing monomer having a reactive functional group can be contained as a monomer unit. By using the amide group-containing monomer, a pressure-sensitive adhesive layer having excellent adhesion can be obtained. The amide group-containing monomer is a compound containing an amide group in its structure and containing a polymerizable unsaturated double bond such as a (meth) acryloyl group and a vinyl group.

Specific examples of the amide group-containing monomer include (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-isopropylacrylamide, N-methyl (meth) acrylamide, and N. -Butyl (meth) acrylamide, N-hexyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methylol-N-propane (meth) acrylamide, aminomethyl (meth) acrylamide, aminoethyl (meth) acrylamide, mercapto Acrylamide-based monomers such as methyl (meth) acrylamide and mercaptoethyl (meth) acrylamide; N-acrylloyl heterocyclic monomers such as N- (meth) acryloylmorpholin, N- (meth) acryloylpiperidin, and N- (meth) acryloylpyrrolidine; Examples thereof include N-vinyl group-containing lactam-based monomers such as N-vinylpyrrolidone and N-vinyl-ε-caprolactam.

As the monomer unit constituting the (meth) acrylic polymer, the blending ratio (total amount) of the monomers having the reactive functional group is 20% by weight or less based on all the monomers constituting the (meth) acrylic polymer. Is preferable, 10% by weight or less is more preferable, 0.01 to 8% by weight is further preferable, 0.01 to 5% by weight is particularly preferable, and 0.05 to 3% by weight is most preferable. If it exceeds 20% by weight, the number of cross-linking points increases and the flexibility of the pressure-sensitive adhesive (layer) is lost, so that the stress relaxation property tends to be poor.

As the monomer unit constituting the (meth) acrylic polymer, in addition to the monomer having a reactive functional group, other copolymerizable monomers can be introduced as long as the effects of the present invention are not impaired. The blending ratio is not particularly limited, but is preferably 30% by weight or less, and more preferably not contained, in all the monomers constituting the (meth) acrylic polymer. If it exceeds 30% by weight, the number of reaction points with the film tends to decrease, and the adhesion tends to decrease, especially when a material other than the (meth) acrylic monomer is used.

In the present invention, when the (meth) acrylic polymer is used, one having a weight average molecular weight (Mw) in the range of 1 million to 2.5 million is usually used. Considering durability, particularly heat resistance and flexibility, it is preferably 1.2 million to 2.2 million, more preferably 1.4 million to 2 million. When the weight average molecular weight is smaller than 1 million, in order to ensure durability, when cross-linking polymer chains, the number of cross-linking points is larger than that of a polymer chain having a weight average molecular weight of 1 million or more, and an adhesive (layer) is used. ) Is lost, so that the dimensional changes between the bending outer side (convex side) and the bending inner side (concave side) that occur between the films during bending cannot be alleviated, and the film is likely to break. Further, when the weight average molecular weight becomes larger than 2.5 million, a large amount of diluting solvent is required to adjust the viscosity for coating, which is not preferable because it increases the cost, and the obtained (meth) acrylic type. Since the entanglement of the polymer chains of the polymer becomes complicated, the flexibility is inferior and the film is liable to break at the time of bending. The weight average molecular weight (Mw) is a value measured by GPC (gel permeation chromatography) and calculated in terms of polystyrene.

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

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

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

Examples of the polymerization initiator include 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-amidinopropane) dihydrochloride, and 2,2'-azobis [2- (5-methyl-). 2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis (2-methylpropionamidine) disulfate, 2,2'-azobis (N, N'-dimethyleneisobutyramidin), 2, Azo-based initiators such as 2'-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate (trade name: VA-057, manufactured by Wako Pure Chemical Industries, Ltd.), potassium persulfate, Persulfate such as ammonium persulfate, di (2-ethylhexyl) peroxydicarbonate, di (4-t-butylcyclohexyl) peroxydicarbonate, di-sec-butylperoxydicarbonate, t-butylperoxyneodeca Noate, t-hexylperoxypivalate, t-butylperoxypivalate, dilauroyl peroxide, di-n-octanoyl peroxide, 1,1,3,3-tetramethylbutylperoxy-2-ethyl Hexanoate, di (4-methylbenzoyl) peroxide, dibenzoyl peroxide, t-butylperoxyisobutyrate, 1,1-di (t-hexylperoxy) cyclohexane, t-butylhydroperoxide, peroxide Examples include peroxide-based initiators such as hydrogen, redox-based initiators in which a peroxide and a reducing agent such as a combination of persulfate and sodium hydrogen sulfite, and a combination of peroxide and sodium ascorbate are combined. Yes, but not limited to these.

The polymerization initiator may be used alone or in admixture of two or more, but the content as a whole is, for example, with respect to 100 parts by weight of all the monomers constituting the (meth) acrylic polymer. , 0.005 to 1 part by weight, more preferably about 0.02 to 0.5 part by weight.

Further, when a chain transfer agent, an emulsifier used for emulsion polymerization or a reactive emulsifier is used, conventionally known ones can be appropriately used. Further, the amount of these additions can be appropriately determined as long as the effects of the present invention are not impaired.

<Crosslinking agent>
The pressure-sensitive adhesive composition of the present invention may contain a cross-linking agent. As the cross-linking agent, an organic cross-linking agent or a polyfunctional metal chelate can be used. Examples of the organic cross-linking agent include an isocyanate-based cross-linking agent, a peroxide-based cross-linking agent, an epoxy-based cross-linking agent, and an imine-based cross-linking agent. A polyfunctional metal chelate is one in which a polyvalent metal is covalently or coordinated to an organic compound. Examples of the polyvalent metal atom include Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, Sn, Ti and the like. Can be mentioned. Examples of the atom in the organic compound having a covalent bond or a coordination bond include an oxygen atom, and examples of the organic compound include an alkyl ester, an alcohol compound, a carboxylic acid compound, an ether compound, and a ketone compound. Among them, isocyanate-based cross-linking agents (particularly, trifunctional isocyanate-based cross-linking agents) are preferable in terms of durability, and peroxide-based cross-linking agents and isocyanate-based cross-linking agents (particularly, bifunctional isocyanate-based cross-linking agents) are preferable. Is preferable from the viewpoint of flexibility. Both peroxide-based crosslinkers and bifunctional isocyanate-based crosslinkers form flexible two-dimensional crosslinks, whereas trifunctional isocyanate-based crosslinkers form stronger three-dimensional crosslinks. At the time of bending, two-dimensional cross-linking, which is a more flexible cross-linking, is advantageous. However, since the durability is poor and the peeling is likely to occur only by the two-dimensional cross-linking, the hybrid cross-linking of the two-dimensional cross-linking and the three-dimensional cross-linking is good. It is a preferable embodiment to use or a bifunctional isocyanate-based cross-linking agent in combination.

The amount of the cross-linking agent used is, for example, preferably 0.01 to 10 parts by weight, more preferably 0.03 to 2 parts by weight, based on 100 parts by weight of the (meth) acrylic polymer. If it is within the above range, the bending resistance is excellent and it is a preferable embodiment.

<Other additives>
Further, the pressure-sensitive adhesive composition in the present invention may contain other known additives, for example, various silane coupling agents, polyether compounds of polyalkylene glycol such as polypropylene glycol, colorants, pigments and the like. Powders, dyes, surfactants, plasticizers, tackifiers, surface lubricants, leveling agents, softeners, antioxidants, antioxidants, light stabilizers, UV absorbers, polymerization inhibitors, antistatics Agents (alkenyl metal salts, ionic liquids, etc., which are ionic compounds), inorganic or organic fillers, metal powders, particles, foils, and the like can be appropriately added depending on the intended use. Further, a redox system to which a reducing agent is added may be adopted within a controllable range.

[Other adhesive layer]
Of the plurality of pressure-sensitive adhesive layers used in the laminate for a flexible image display device of the present invention, the second pressure-sensitive adhesive layer is arranged on the side opposite to the surface in contact with the polarizing film with respect to the retardation film. be able to.

Of the plurality of pressure-sensitive adhesive layers used in the laminate for a flexible image display device of the present invention, the third pressure-sensitive adhesive layer is in contact with the second pressure-sensitive adhesive layer with respect to the transparent conductive layer constituting the touch sensor. A third pressure-sensitive adhesive layer can be placed on the opposite side of the surface.

Of the plurality of pressure-sensitive adhesive layers used in the laminate for a flexible image display device of the present invention, the third pressure-sensitive adhesive layer is in contact with the first pressure-sensitive adhesive layer with respect to the transparent conductive layer constituting the touch sensor. It can be placed on the opposite side of the surface.

When a second pressure-sensitive adhesive layer and further other pressure-sensitive adhesive layers (for example, a third pressure-sensitive adhesive layer, etc.) are used in addition to the first pressure-sensitive adhesive layer, these pressure-sensitive adhesive layers are the same. The composition (same pressure-sensitive adhesive composition), whether it has the same properties or different properties, is not particularly limited, but when the laminate is bent among the plurality of pressure-sensitive adhesive layers. The storage elastic modulus G'at 25 ° C. of the outermost pressure-sensitive adhesive layer on the convex side of the above is required to be substantially the same as or smaller than the storage elastic modulus G'at 25 ° C. of another pressure-sensitive adhesive layer. Further, from the viewpoint of workability, economy, and flexibility, it is preferable that all the pressure-sensitive adhesive layers are pressure-sensitive adhesive layers having substantially the same composition and the same characteristics.

<Formation of adhesive layer>
The plurality of pressure-sensitive adhesive layers in the present invention are preferably formed from the pressure-sensitive adhesive composition. Examples of the method for forming the pressure-sensitive adhesive layer include a method in which the pressure-sensitive adhesive composition is applied to a separator or the like that has been peeled off, and a polymerization solvent or the like is dried and removed to form the pressure-sensitive adhesive layer. Further, it can also be produced by a method of applying the pressure-sensitive adhesive composition to a polarizing film or the like and drying and removing a polymerization solvent or the like to form a pressure-sensitive adhesive layer on the polarizing film or the like. When applying the pressure-sensitive adhesive composition, one or more solvents other than the polymerization solvent may be newly added as appropriate.

As the peeling-treated separator, a silicone peeling liner is preferably used. When the pressure-sensitive adhesive composition of the present invention is applied onto such a liner and dried to form a pressure-sensitive adhesive layer, an appropriate method can be appropriately adopted as a method for drying the pressure-sensitive adhesive. .. Preferably, a method of heating and drying the coating film is used. The heating and drying temperature is, for example, preferably 40 to 200 ° C., more preferably 50 to 180 ° C., and particularly preferably 70 to 70 to 40 ° C. when preparing an acrylic pressure-sensitive adhesive using a (meth) acrylic polymer. It is 170 ° C. By setting the heating temperature in the above range, a pressure-sensitive adhesive having excellent adhesive properties can be obtained.

As the drying time, an appropriate time may be adopted as appropriate. The drying time is preferably 5 seconds to 20 minutes, more preferably 5 seconds to 10 minutes, and particularly preferably 10 seconds to 5 minutes when preparing an acrylic pressure-sensitive adhesive using, for example, a (meth) acrylic polymer. Minutes.

Various methods are used as the method for applying the pressure-sensitive adhesive composition. Specifically, for example, 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 include the extrusion coating method.

The thickness of the pressure-sensitive adhesive layer used in the laminate for a flexible image display device of the present invention is preferably 1 to 200 μm, more preferably 5 to 150 μm, and further preferably 10 to 100 μm. The pressure-sensitive adhesive layer may be a single layer or may have a laminated structure. Within the above range, it is a preferable embodiment without hindering bending and in terms of adhesion (retention resistance). Further, when a plurality of pressure-sensitive adhesive layers are provided, it is preferable that all the pressure-sensitive adhesive layers are within the above range.

Of the plurality of pressure-sensitive adhesive layers used in the laminated body for the flexible image display device of the present invention, the storage elastic modulus G'at 25 ° C. of the outermost surface pressure-sensitive adhesive layer on the convex side when the laminated body is bent is the other. It is characterized in that it is substantially the same as or smaller than the storage elastic modulus G'at 25 ° C. of the pressure-sensitive adhesive layer. When a plurality of storage elastic moduli (G') are substantially the same, the stress generated during bending (bending) is not biased to some layers, so that each film / layer (for example, an optical film such as a polarizing film) is not biased. ) Is suppressed, and peeling of the pressure-sensitive adhesive layer / adhesive layer is suppressed, which is preferable.
Further, for example, when the optical laminated body is used as the optical film, the storage elastic modulus (G') is such that the retardation film side is on the convex side (outside) and the laminated body for the flexible image display device is centered. When the adhesive layer on the retardation side receives a pulling force when it is bent and becomes smaller toward the convex side, the pulling force becomes smaller from the convex side (outside) to the concave side (inside). go. The pressure-sensitive adhesive layer that receives the force in the tensile direction is a pressure-sensitive adhesive layer that relieves stress. Since the stress applied from the convex side (outside) to the concave side (inside) becomes small, bending resistance is ensured even if G'is larger than the outermost layer side. Compared with the case where the size increases toward the convex side (outside), breakage of each film / layer and peeling between layers are eliminated, which is a preferable embodiment.
In addition, substantially the same means that the difference in the storage elastic modulus (G') between the pressure-sensitive adhesive layers is within ± 15% of the average value of the storage elastic modulus (G') of the plurality of pressure-sensitive adhesive layers. Preferably, it means that it is within the range of ± 10%.

The storage elastic modulus (G') of the pressure-sensitive adhesive layer used in the laminate for a flexible image display device of the present invention is preferably 1.0 MPa or less, more preferably 0.8 MPa or less, still more preferably at 25 ° C. Is 0.3 MPa or less. If the storage elastic modulus of the adhesive layer is within such a range, the adhesive layer does not become hard easily, has excellent stress relaxation properties, and has excellent bending resistance. Therefore, a flexible image display device that can be bent or folded is realized. can do.

In particular, when the laminated body for a flexible image display device is bent at the center, the innermost storage elastic modulus (G') on the concave side (inside) is preferably 0.05 to 0.2 MPa at 25 ° C. Yes, more preferably 0.05 to 0.15 MPa. If it exceeds 0.2 MPa, the stress applied at the time of bending cannot be relaxed, and the film such as an optical film is likely to break. If it is less than 0.05 MPa, it completely follows the dimensional change between the films during continuous bending, so that the durability of the bent portion deteriorates due to the exhaustion deterioration of the adhesive layer, and peeling and foaming are likely to occur.
Further, when the laminated body for a flexible image display device is bent at the center, the outermost storage elastic modulus (G') on the convex side (outside) is preferably 0.01 to 0.15 MPa at 25 ° C. Yes, more preferably 0.01 to 0.1 MPa. If it exceeds 0.15 MPa, the shear stress generated at the time of bending cannot be relaxed, and the film such as an optical film is likely to break. If it is less than 0.01 MPa, it completely follows the dimensional change between the films during continuous bending, so that the durability of the bent portion deteriorates due to the exhaustion deterioration of the adhesive layer, and peeling and foaming are likely to occur.
When a plurality of pressure-sensitive adhesive layers are present, the storage elastic modulus (G') of the pressure-sensitive adhesive layer located in the middle is preferably 0.01 to 0.2 MPa, more preferably 0.01 to 0 at 25 ° C. It is .15 MPa. Since the pressure-sensitive adhesive layer is located in the middle of the laminated product, it is most difficult to apply stress. Therefore, the storage elastic modulus (G') of the pressure-sensitive adhesive layers on the convex side (outside) and the concave side (inside) of the plurality of pressure-sensitive adhesive layers. The applicable range is the sum of the ranges of. If it is within the above range, the film on the convex side does not break at the time of bending, which is preferable.

The upper limit of the glass transition temperature (Tg) of the pressure-sensitive adhesive layer used in the laminate for a flexible image display device of the present invention is preferably 0 ° C. or lower, more preferably −20 ° C. or lower, still more preferably −25. It is below ° C. When the Tg of the pressure-sensitive adhesive layer is within such a range, it is possible to realize a flexible image display device that is flexible or foldable, has excellent stress relaxation property, and the pressure-sensitive adhesive layer does not easily become hard even in a high speed region at the time of bending. can.

The total light transmittance (according to JIS K7136) in the visible light wavelength region of the pressure-sensitive adhesive layer used in the laminate for a flexible image display device of the present invention is preferably 85% or more, more preferably 90% or more.

The haze of the pressure-sensitive adhesive layer (according to JIS K7136) used in the laminate for a flexible image display device of the present invention is preferably 3.0% or less, more preferably 2.0% or less.

The total light transmittance and the haze can be measured using, for example, a haze meter (manufactured by Murakami Color Technology Research Institute, trade name "HM-150").

[Transparent conductive layer]
The member having a transparent conductive layer is not particularly limited, and a known member can be used, but a member having a transparent conductive layer on a transparent substrate such as a transparent film, or a transparent conductive layer and a liquid crystal display. A member having a cell can be mentioned.

The transparent base material may be any one having transparency, and examples thereof include a base material made of a resin film or the like (for example, a sheet-shaped, film-shaped, plate-shaped base material, or the like). The thickness of the transparent substrate is not particularly limited, but is preferably about 10 to 200 μm, more preferably about 15 to 150 μm.

The material of the resin film is not particularly limited, and examples thereof include various transparent plastic materials. For example, the materials thereof include polyester resins such as polyethylene terephthalate and polyethylene naphthalate, acetate resins, polyether sulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, and (meth) acrylic resins. , Polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl alcohol resin, polyallylate resin, polyphenylene sulfide resin and the like. Of these, polyester-based resins, polyimide-based resins and polyether sulfone-based resins are particularly preferable.

Further, the transparent substrate is subjected to etching treatment such as sputtering, corona discharge, flame, ultraviolet irradiation, electron beam irradiation, chemical conversion, oxidation, etc. and an undercoating treatment in advance on the surface of the transparent substrate, and the transparent conductive layer provided on the transparent base material. The adhesion to the transparent substrate may be improved. Further, before the transparent conductive layer is provided, dust may be removed and cleaned by solvent cleaning, ultrasonic cleaning, or the like, if necessary.

The constituent material of the transparent conductive layer is not particularly limited, and is selected from the group consisting of indium, tin, zinc, gallium, antimony, titanium, silicon, zirconium, magnesium, aluminum, gold, silver, copper, palladium, and tungsten. A metal oxide of at least one metal is used. The metal oxide may further contain the metal atoms shown in the above group, if necessary. For example, indium oxide (ITO) containing tin oxide, tin oxide containing antimony, and the like are preferably used, and ITO is particularly preferably used. The ITO preferably contains 80 to 99% by weight of indium oxide and 1 to 20% by weight of tin oxide.

Further, examples of the ITO include crystalline ITO and non-crystalline (amorphous) ITO. The crystalline ITO can be obtained by applying a high temperature at the time of sputtering or further heating the amorphous ITO.

The thickness of the transparent conductive layer of the present invention is preferably 0.005 to 10 μm, more preferably 0.01 to 3 μm, and further preferably 0.01 to 1 μm. When the thickness of the transparent conductive layer is less than 0.005 μm, the change in the electric resistance value of the transparent conductive layer tends to be large. On the other hand, when it exceeds 10 μm, the productivity of the transparent conductive layer is lowered, the cost is increased, and the optical characteristics tend to be lowered.

The total light transmittance of the transparent conductive layer of the present invention is preferably 80% or more, more preferably 85% or more, and further preferably 90% or more.

The density of the transparent conductive layer of the present invention is preferably 1.0 to 10.5 g / cm ³ , and more preferably 1.3 to 3.0 g / cm ³ .

The surface resistance value of the transparent conductive layer of the present invention is preferably 0.1 to 1000 Ω / □, more preferably 0.5 to 500 Ω / □, and further preferably 1 to 250 Ω / □.

The method for forming the transparent conductive layer is not particularly limited, and a conventionally known method can be adopted. Specifically, for example, a vacuum vapor deposition method, a sputtering method, and an ion plating method can be exemplified. Further, an appropriate method can be adopted depending on the required film thickness.

Further, an undercoat layer, an oligomer prevention layer and the like can be provided between the transparent conductive layer and the transparent substrate, if necessary.

The transparent conductive layer constitutes a touch sensor and is required to be bendable.

In the laminated body for a flexible image display device of the present invention, the transparent conductive layer constituting the touch sensor may be arranged on the side opposite to the surface in contact with the retardation film with respect to the second pressure-sensitive adhesive layer. can.

In the laminated body for a flexible image display device of the present invention, the transparent conductive layer constituting the touch sensor may be arranged on the side opposite to the surface in contact with the protective film with respect to the first pressure-sensitive adhesive layer. can.

Further, in the laminated body for a flexible image display device of the present invention, the transparent conductive layer constituting the touch sensor can be arranged between the protective film and the window film (OCA).

The transparent conductive layer can be suitably applied to a liquid crystal display device having a built-in touch sensor such as an in-cell type or an on-cell type when used in a flexible image display device, and in particular, the touch sensor is built in the organic EL display panel. May be (embedded)

[Conductive layer (antistatic layer)]
Further, the laminated body for a flexible image display device of the present invention may have a conductive layer (conductive layer, antistatic layer). Since the laminated body for a flexible image display device has a bending function and has a very thin thickness structure, the laminated body has high reactivity with weak static electricity generated in a manufacturing process or the like and is easily damaged. By providing the conductive layer on the surface, the load due to static electricity in the manufacturing process or the like is greatly reduced, which is a preferable embodiment.

Further, one of the major features of the flexible image display device including the laminated body is that it has a bending function, but when it is continuously bent, static electricity is generated due to shrinkage between the films (base materials) at the bending portion. In some cases. Therefore, when the laminated body is imparted with conductivity, the generated static electricity can be quickly removed, and the damage caused by the static electricity of the image display device can be reduced, which is a preferable embodiment.

Further, the conductive layer may be an undercoat layer having a conductive function, an adhesive containing a conductive component, or a surface treatment layer containing a conductive component. For example, a method of forming a conductive layer between the polarizing film and the pressure-sensitive adhesive layer by using an antistatic agent composition containing a conductive polymer such as polythiophene and a binder can be adopted. Further, a pressure-sensitive adhesive containing an ionic compound which is an antistatic agent can also be used. Further, the conductive layer preferably has one or more layers, and may include two or more layers.

[Flexible image display device]
The flexible image display device of the present invention includes the above-mentioned laminate for a flexible image display device and an organic EL display panel, and the laminate for a flexible image display device is arranged on the visual side with respect to the organic EL display panel and is bent. It is configured to be possible. Although optional, the window can be arranged on the visual side with respect to the laminated body for the flexible image display device.

FIG. 2 is a cross-sectional view showing one embodiment of the flexible image display device according to the present invention. The flexible image display device 100 includes a stack 11 for a flexible image display device and an organic EL display panel 10 configured to be foldable. A laminated body 11 for a flexible image display device is arranged on the visual recognition side with respect to the organic EL display panel 10, and the flexible image display device 100 is configured to be bendable. Further, although optional, a transparent window 40 can be arranged on the visual side of the laminated body 11 for a flexible image display device via the first adhesive layer 12-1.

The laminated body 11 for a flexible image display device further includes an optical laminated body 20 and a pressure-sensitive adhesive layer constituting a second pressure-sensitive adhesive layer 12-2 and a third pressure-sensitive adhesive layer 12-3.

The optical laminate 20 includes a polarizing film 1, a protective film 2 made of a transparent resin material, and a retardation film 3. The protective film 2 made of a transparent resin material is bonded to the first surface of the polarizing film 1 on the visible side. The retardation film 3 is joined to a second surface different from the first surface of the polarizing film 1. The polarizing film 1 and the retardation film 3 generate circular polarization or have a viewing angle, for example, in order to prevent light incident inside from the viewing side of the polarizing film 1 from being internally reflected and emitted to the viewing side. It is for compensating for.

In the present embodiment, the protective film is provided on both sides of the conventional polarizing film, whereas the protective film is provided on only one side, and the polarizing film itself is also used in the conventional organic EL display device. By using a polarizing film having a thickness very thin (20 μm or less) as compared with the polarizing film, the thickness of the optical laminate 20 can be reduced. Further, since the polarizing film 1 is much thinner than the polarizing film used in the conventional organic EL display device, the stress due to expansion and contraction generated under temperature or humidity conditions becomes extremely small. Therefore, the possibility that the stress caused by the shrinkage of the polarizing film causes deformation such as warpage in the adjacent organic EL display panel 10 is greatly reduced, and the deterioration of display quality and the destruction of the panel encapsulating material due to the deformation are greatly reduced. It becomes possible to suppress it. Further, the use of a thin polarizing film does not hinder bending, which is a preferable embodiment.

When the optical laminate 20 is bent with the protective film 2 side as the inside, the thickness of the optical laminate 20 (for example, 92 μm or less) is reduced, and the first pressure-sensitive adhesive layer 12-1 having the storage elastic modulus as described above is obtained. Is arranged on the side opposite to the retardation film 3 with respect to the protective film 2, so that the stress applied to the optical laminate 20 can be reduced, whereby the optical laminate 20 can be bent. Further, therefore, an appropriate storage elastic modulus range may be set according to the environmental temperature in which the flexible image display device is used. For example, when the assumed operating environment temperature is −20 ° C. to + 85 ° C., the first pressure-sensitive adhesive layer can be used so that the storage elastic modulus at 25 ° C. is in an appropriate numerical range.

Although optional, a bendable transparent conductive layer 6 constituting the touch sensor can be further arranged on the side opposite to the protective film 2 with respect to the retardation film 3. The transparent conductive layer 6 is configured to be directly bonded to the retardation film 3 by, for example, a manufacturing method as shown in Japanese Patent Application Laid-Open No. 2014-219667, whereby the thickness of the optical laminate 20 is reduced, and the optical laminate 20 is formed. It is possible to further reduce the stress applied to the optical laminated body 20 when the product is bent.

Although optional, the pressure-sensitive adhesive layer constituting the third pressure-sensitive adhesive layer 12-3 can be further arranged on the side opposite to the retardation film 3 with respect to the transparent conductive layer 6. In the present embodiment, the second pressure-sensitive adhesive layer 12-2 is directly bonded to the transparent conductive layer 6. By providing the second pressure-sensitive adhesive layer 12-2, the stress applied to the optical laminated body 20 when the optical laminated body 20 is bent can be further reduced.

The flexible image display device shown in FIG. 3 is almost the same as that shown in FIG. 2, but in the flexible image display device of FIG. 2, the touch sensor is on the opposite side of the retardation film 3 from the protective film 2. In contrast to the foldable transparent conductive layer 6 that constitutes the above, in the flexible image display device of FIG. 3, the side opposite to the protective film 2 with respect to the first pressure-sensitive adhesive layer 12-1. The difference is that the bendable transparent conductive layer 6 constituting the touch sensor is arranged. Further, in the flexible image display device of FIG. 2, the third pressure-sensitive adhesive layer 12-3 is arranged on the side opposite to the retardation film 3 with respect to the transparent conductive layer 2, whereas in FIG. The flexible image display device differs in that the second pressure-sensitive adhesive layer 12-2 is arranged on the side opposite to the protective film 2 with respect to the retardation film 3.

Further, although optional, the third adhesive layer 12-3 can be arranged when the window 40 is arranged on the visual recognition side with respect to the laminated body 11 for the flexible image display device.

The flexible image display device of the present invention can be suitably used as a flexible liquid crystal display device, an organic EL (electroluminescence) display device, an image display device such as electronic paper, and the like. Further, it can be used regardless of a method such as a touch panel such as a resistance film method or a capacitance method.

Further, as the flexible image display device of the present invention, as shown in FIG. 4, it is also used as an in-cell type flexible image display device in which the transparent conductive layer 6 constituting the touch sensor is built in the organic EL display panel 10-1. It is possible to do.

Hereinafter, some examples related to the present invention will be described, but the present invention is not intended to be limited to those shown in such specific examples. The numerical values in the table are the blending amount (addition amount), and indicate the solid content or the solid content ratio (weight basis). The compounding contents and evaluation results are shown in Tables 1 to 4.

[Example 1]
[Polarizing film]
An amorphous polyethylene terephthalate (hereinafter, also referred to as “PET”) (IPA copolymerized PET) film (thickness: 100 μm) having 7 mol% of isophthalic acid unit was prepared as a thermoplastic resin base material, and the surface was treated with corona (thickness: 100 μm). 58 W / m ² / min) was applied. On the other hand, acetacetyl-modified PVA (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name: Gosefimer Z200 (average degree of polymerization: 1200, degree of polymerization: 98.5 mol%, degree of acetacetylation: 5 mol%)) Prepare PVA (polymerization degree 4200, saponification degree 99.2%) added in an amount of 1% by weight, prepare a coating solution of a PVA aqueous solution having a PVA-based resin of 5.5% by weight, and measure the thickness after drying. Was coated to 12 μm and dried in an atmosphere of 60 ° C. for 10 minutes by hot air drying to prepare a laminate having a PVA-based resin layer on the substrate.

Next, this laminated body was first stretched 1.8 times at a free end at 130 ° C. in the air (aerial auxiliary stretching) to produce a stretched laminated body. Next, a step of insolubilizing the PVA layer in which the PVA molecules contained in the stretched laminate were oriented was performed by immersing the stretched laminate in a boric acid insoluble aqueous solution having a liquid temperature of 30 ° C. for 30 seconds. The boric acid insolubilized aqueous solution in this step had a boric acid content of 3 parts by weight with respect to 100 parts by weight of water. A colored laminate was produced by dyeing this stretched laminate. In the colored laminate, the stretched laminate is mixed with a dyeing solution containing iodine and potassium iodide at a liquid temperature of 30 ° C., so that the single transmittance of the PVA layer constituting the final polarizing film is 40 to 44%. The PVA layer contained in the stretched laminate was stained with iodine by immersing it in an arbitrary time. In this step, the dyeing solution used water as a solvent and had an iodine concentration in the range of 0.1 to 0.4% by weight and a potassium iodide concentration in the range of 0.7 to 2.8% by weight. The ratio of iodine to potassium iodide concentrations is 1: 7. Next, a step of cross-linking the PVA molecules of the PVA layer on which iodine was adsorbed was performed by immersing the colored laminate in a boric acid cross-linked aqueous solution at 30 ° C. for 60 seconds. The boric acid crosslinked aqueous solution in this step had a boric acid content of 3 parts by weight with respect to 100 parts by weight of water and a potassium iodide content of 3 parts by weight with respect to 100 parts by weight of water.

Further, the obtained colored laminate was stretched 3.05 times in the same direction as the previous stretching in air (boric acid water stretching) at a stretching temperature of 70 ° C. in a boric acid aqueous solution, and finally. An optical film laminate having a draw ratio of 5.50 times was obtained. The optical film laminate was taken out from the boric acid aqueous solution, and the boric acid adhering to the surface of the PVA layer was washed with an aqueous solution having a potassium iodide content of 4 parts by weight based on 100 parts by weight of water. The washed optical film laminate was dried by a drying step with warm air at 60 ° C. The thickness of the polarizing film contained in the obtained optical film laminate was 5 μm.

[Protective film]
As the protective film, a methacrylic resin pellet having a glutarimide ring unit was extruded, formed into a film, and then stretched. This protective film was an acrylic film having a thickness of 20 μm and a moisture permeability of 160 g / m ² .

Next, the polarizing film and the protective film were bonded together using the adhesive shown below to obtain a polarizing film.

As the adhesive (active energy ray-curable adhesive), each component is mixed according to the formulation table shown in Table 1, stirred at 50 ° C. for 1 hour, and the adhesive (active energy ray-curable adhesive A). Was prepared. The numerical values in the table indicate the weight% when the total amount of the composition is 100% by weight. The components used are as follows.
HEAA: Hydroxyethylacrylamide M-220: ARONIX M-220, Tripropylene glycol diacrylate), ACMO: Acryloylmorpholin AAEM: 2-acetoacetoxyethyl methacrylate, UP-1190: ARUFON UP- 1190, Toagosei IRG907: IRGACURE907, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropane-1-one, BASF DETX-S: KAYACURE DETX-S, diethylthioxanthone, Nippon Kayaku Made by Yakusha

In the examples and comparative examples using the adhesive, the protective film and the polarizing film are laminated via the adhesive, and then the adhesive is cured by irradiating with ultraviolet rays to cure the adhesive layer. Was formed. For UV irradiation, gallium-filled metal halide lamp (Fusion UV Systems, Inc., trade name "Light HAMMER10", bulb: V bulb, peak illuminance: 1600 mW / cm ² , integrated irradiation dose 1000 / mJ / cm ² (wavelength) 380-440 nm)) was used.

[Phase difference film]
The retardation film (1/4 wavelength retardation plate) of this embodiment is composed of two layers, a retardation layer for a 1/4 wavelength plate and a retardation layer for a 1/2 wavelength plate in which a liquid crystal material is oriented and immobilized. It was a composed retardation film. Specifically, it was manufactured as follows.

(Liquid crystal material)
As a material for forming the retardation layer for 1/2 wave plate and the retardation layer for 1/4 wave plate, a polymerizable liquid crystal material showing a nematic liquid crystal phase (manufactured by BASF, trade name: Paliocolor LC242) was used. A photopolymerization initiator (manufactured by BASF, trade name: Irgacure 907) for the polymerizable liquid crystal material was dissolved in toluene. Further, for the purpose of improving the coatability, a megafuck series made by DIC was added in an amount of about 0.1 to 0.5% depending on the thickness of the liquid crystal to prepare a liquid crystal coating liquid. The liquid crystal coating liquid was applied onto the oriented substrate with a bar coater, dried by heating at 90 ° C. for 2 minutes, and then oriented and fixed by UV curing in a nitrogen atmosphere. As the substrate, a substrate such as PET, which can transfer the liquid crystal coating layer later, was used. Further, for the purpose of improving coatability, about 0.1% to 0.5% of a fluoropolymer, which is a megafuck series made by DIC, is added depending on the thickness of the liquid crystal layer, and MIBK (methyl isobutyl ketone), cyclohexanone, or MIBK is added. A coating solution was prepared by dissolving the mixture in a solid content concentration of 25% using a mixed solvent of cyclohexanone and cyclohexanone. This coating liquid was applied to a base material with a wire bar to obtain a drying step of 3 minutes at a setting of 65 ° C., and the orientation was fixed by ultraviolet curing in a nitrogen atmosphere. As the substrate, a substrate such as PET, which can transfer the liquid crystal coating layer later, was used.

(Manufacturing process)
The manufacturing process of this embodiment will be described with reference to FIG. The numbers in FIG. 8 are different from the numbers in other drawings. In this manufacturing step 20, the base material 14 is provided by a roll, and the base material 14 is supplied from the supply reel 21. In the manufacturing process 20, the coating liquid of the ultraviolet curable resin 10 was applied to the base material 14 by the die 22. In this manufacturing step 20, the roll plate 30 was a cylindrical mold for forming a concave-convex shape related to the alignment film for the 1/4 wave plate of the 1/4 wave plate on the peripheral side surface. In the manufacturing step 20, the base material 14 coated with the ultraviolet curable resin is pressed against the peripheral side surface of the roll plate 30 by the pressure roller 24, and the ultraviolet curable resin is produced by irradiation with ultraviolet rays by the ultraviolet irradiation device 25 composed of a high-pressure mercury lamp. It was cured. As a result, in the manufacturing process 20, the uneven shape formed on the peripheral side surface of the roll plate 30 was transferred to the base material 14 so as to be 75 ° with respect to the MD direction. Then, the base material 14 was peeled from the roll plate 30 integrally with the ultraviolet curable resin 10 cured by the peeling roller 26, and the liquid crystal material was applied by the die 29. After that, the liquid crystal material was cured by irradiation with ultraviolet rays by the ultraviolet irradiation device 27, and a configuration related to the retardation layer for a quarter wave plate was created by these.
Subsequently, in this step 20, the base material 14 is conveyed to the die 32 by the transfer roller 31, and the coating liquid of the ultraviolet curable resin 12 is applied onto the retardation layer for the 1/4 wave plate of the base material 14 by the die 32. bottom. In this manufacturing step 20, the roll plate 40 was a cylindrical mold for forming a concave-convex shape related to the alignment film for the 1/2 wave plate of the 1/4 wavelength retardation plate on the peripheral side surface. In the manufacturing process 20, the base material 14 coated with the ultraviolet curable resin is pressed against the peripheral side surface of the roll plate 40 by the pressure roller 34, and the ultraviolet curable resin is produced by irradiation with ultraviolet rays by the ultraviolet irradiation device 35 composed of a high-pressure mercury lamp. It was cured. As a result, in the manufacturing step 20, the uneven shape formed on the peripheral side surface of the roll plate 40 was transferred to the base material 14 so as to be 15 ° with respect to the MD direction. Then, the base material 14 was peeled from the roll plate 40 integrally with the ultraviolet curable resin 12 cured by the peeling roller 36, and the liquid crystal material was applied by the die 39. After that, the liquid crystal material is cured by irradiation with ultraviolet rays by the ultraviolet irradiation device 37, thereby creating a configuration related to the retardation layer for 1/2 wave plate, and the retardation layer for 1/4 wave plate and 1/2 wavelength. A phase difference film having a thickness of 7 μm composed of two layers of a wave plate retardation layer was obtained.

[Optical film (optical laminate)]
The retardation film obtained as described above and the polarizing film obtained as described above are continuously bonded together using the above adhesive by a roll-to-roll method, and the axes of the slow phase axis and the absorption axis are bonded together. A laminated film (optical laminated body) was produced so that the angle was 45 °.

Next, the obtained laminated film (optical laminated body) was cut into 15 cm × 5 cm.

[Second adhesive layer]
<Preparation of (meth) acrylic polymer A1>
A four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a cooler was charged with a monomer mixture containing 99 parts by weight of butyl acrylate (BA) and 1 part by weight of 4-hydroxybutyl acrylate (HBA). ..
Further, 0.1 part by weight of 2,2'-azobisisobutyronitrile as a polymerization initiator is charged with ethyl acetate with respect to 100 parts by weight of the monomer mixture (solid content), and nitrogen gas is gently stirred. Was introduced and replaced with nitrogen, and then the polymerization reaction was carried out for 7 hours while keeping the liquid temperature in the flask at around 55 ° C. Then, ethyl acetate was added to the obtained reaction solution to prepare a solution of (meth) acrylic polymer A1 having a weight average molecular weight of 1.6 million, which was adjusted to a solid content concentration of 30%.

<Preparation of acrylic pressure-sensitive adhesive composition>
0.1 weight by weight of an isocyanate-based cross-linking agent (trade name: Takenate D110N, trimethylolpropane xylylene diisocyanate, manufactured by Mitsui Chemicals, Inc.) with respect to 100 parts by weight of the solid content of the obtained (meth) acrylic polymer A1 solution. , 0.3 parts by weight of benzoyl peroxide (trade name: Niper BMT, manufactured by Nippon Oil & Fats Co., Ltd.), which is a peroxide-based cross-linking agent, and silane coupling agent (trade name: KBM403, manufactured by Shin-Etsu Chemical Co., Ltd.). ) 0.08 parts by weight was blended to prepare an acrylic pressure-sensitive adhesive composition.

<Manufacturing an optical laminate with an adhesive layer>
The acrylic pressure-sensitive adhesive composition is uniformly coated on the surface of a 38 μm-thick polyethylene terephthalate film (PET film, transparent substrate, separator) treated with a silicone-based release agent with a fountain coater at 155 ° C. It was dried in an air circulation type constant temperature oven for 2 minutes to form a pressure-sensitive adhesive layer 1 (second pressure-sensitive adhesive layer) having a thickness of 25 μm on the surface of the base material.
Next, a separator having the pressure-sensitive adhesive layer 1 (second pressure-sensitive adhesive layer) was transferred to the protective film side (corona-treated) of the obtained optical laminate to prepare an optical laminate with a pressure-sensitive adhesive layer. ..

[First adhesive layer]
Similar to the second pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer 4 (first pressure-sensitive adhesive layer) is mixed with the pressure-sensitive adhesive layer 4 (first pressure-sensitive adhesive layer) having a thickness of 50 μm based on the blending contents of Tables 2 and 3. A layer) is formed, and a separator having the adhesive layer 4 formed is transferred to the surface (corona-treated) of a PET film (transparent substrate, manufactured by Mitsubishi Resin Co., Ltd., trade name: diamond foil) having a thickness of 75 μm. , A PET film with an adhesive layer was formed.

[Third adhesive layer]
Similar to the second pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer 2 (third pressure-sensitive adhesive layer) is added to the pressure-sensitive adhesive layer 2 (third pressure-sensitive adhesive layer) having a thickness of 50 μm based on the blending contents of Tables 2 and 3. A layer) is formed, and a separator having the adhesive layer 2 formed is transferred to the surface (corona-treated) of a polyimide film (PI film, manufactured by Toray DuPont Co., Ltd., Capton 300V, base material) having a thickness of 77 μm. , A PI film with an adhesive layer was formed.

<Laminate for flexible image display device>
As shown in FIG. 6, the first to third adhesive layers (along with each transparent substrate) obtained as described above are attached to the (meth) acrylic resin film serving as the protective film 2 as a second adhesive. The transparent base material 8-2 (to which the agent layer 12-2 is bonded, the third pressure-sensitive adhesive layer 12-3 is bonded to the retardation film 3, and the second pressure-sensitive adhesive layer 12-2 is further bonded). By adhering the first pressure-sensitive adhesive layer 12-1 to the PET film), a laminated body 11 for a flexible image display device corresponding to the configuration A used in the first embodiment was produced. The laminated body 11 for a flexible image display device corresponding to the configuration B is shown in FIG. 7.

<Preparation of (meth) acrylic polymer A3>
Except that the polymerization reaction was carried out so that the mixing ratio (weight ratio) of ethyl acetate and toluene was 95/5 when the polymerization reaction was carried out for 7 hours while keeping the liquid temperature in the flask at around 55 ° C. Was carried out in the same manner as in the preparation of the (meth) acrylic polymer A1.

<Preparation of (meth) acrylic oligomer (oligomer)>
99 parts by weight of butyl acrylate (BA), 2 parts by weight of acrylic acid (AA), 3 parts by weight of 2-mercaptoethanol, polymerization started in a 4-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a cooler. Add 0.1 part by weight of 2,2'-azobisisobutyronitrile and 140 parts by weight of toluene as an agent, introduce nitrogen gas with gentle stirring to sufficiently replace the nitrogen, and then the liquid temperature in the flask. Was kept at around 70 ° C. and a polymerization reaction was carried out for 8 hours to prepare an acrylic oligomer solution. The weight average molecular weight of the acrylic oligomer was 4500. The obtained oligomer was added in a predetermined amount when mixing a cross-linking agent or the like to prepare an acrylic pressure-sensitive adhesive composition. By using such an oligomer, the effect of improving the durability of the pressure-sensitive adhesive layer and suppressing foaming can be expected.

[Example 8]
Addition reaction type silicone adhesive (trade name "X-40-3306", manufactured by Shin-Etsu Chemical Co., Ltd.) 100 parts by weight, and platinum catalyst (trade name "CAT-PL-50T", manufactured by Shin-Etsu Chemical Co., Ltd.) (Manufactured) 0.2 parts by weight were mixed to obtain a silicone-based pressure-sensitive adhesive composition. This is applied to a PET film and a PI film which are transparent substrates, and the thickness after drying is 50 μm for the first pressure-sensitive adhesive layer and the third pressure-sensitive adhesive layer, respectively, and the second pressure-sensitive adhesive layer. Was applied to a thickness of 25 μm and dried at 100 ° C. for 3 minutes to obtain a silicone-based pressure-sensitive adhesive layer (pressure-sensitive adhesive layer 6) (common to the first to third pressure-sensitive adhesive layers).

[Comparative Example 1]
[Polarizing film]
A polyvinyl alcohol film having a thickness of 50 μm is immersed in the following 5 baths [1] to [5] through multiple sets of rolls having different peripheral speeds while sequentially applying tension in the longitudinal direction of the film, and the final draw ratio is the film. It was stretched so as to be 6.0 times the original length. This film was dried in an oven at 50 ° C. for 4 minutes to obtain a polarizing film having a thickness of 22 μm.
[1] Swelling bath: Pure water at 30 ° C. [2] Dyeing bath: The iodine concentration is in the range of 0.02 to 0.2% by weight and the potassium iodide concentration is 0.14 to 100 parts by weight with respect to 100 parts by weight of water. It was within the range of 1.4% by weight. The ratio of iodine to potassium iodide concentrations is 1: 7. It was immersed in an aqueous solution containing these at 30 ° C. for an arbitrary time so that the final transmittance of the polarizing film was 40 to 44%.
[3] First cross-linking bath: An aqueous solution at 40 ° C. containing 3% by weight of potassium iodide and 3% by weight of boric acid.
[4] Second cross-linking bath: An aqueous solution at 60 ° C. containing 5% by weight of potassium iodide and 4% by weight of boric acid.
[5] Washing bath: An aqueous solution at 25 ° C. containing 3% by weight of potassium iodide Then, the polarizing film and the protective film used in Example 1 are bonded together using the adhesive used in Example 1 and polarized. It was made into a film.

[Optical film (optical laminate)]
The retardation film used in Example 1 and the polarizing film obtained as described above are bonded together using the adhesive used in Example 1, and the axis angle between the slow phase axis and the absorption axis becomes 45 °. As described above, a laminated film was produced.

[Examples 2 to 8 and Comparative Examples 1 to 3]
In the preparation of the polymer ((meth) acrylic polymer) to be used, the pressure-sensitive adhesive composition, and the pressure-sensitive adhesive layer, except for those specified in particular, the examples 1 except for the changes as shown in Tables 2 to 4. In the same manner as above, a laminated body for a flexible image display device was produced. Only in Example 5, the configuration B (see FIG. 7) containing no second pressure-sensitive adhesive layer was adopted.

The abbreviations in Tables 2 and 3 are as follows.
BA: n-butyl acrylate 2EHA: 2-ethylhexyl acrylate AA: acrylic acid HBA: 4-hydroxybutyl acrylate HEA: 2-hydroxyethyl acrylate D110N: trimethylolpropane / xylylene diisocyanate adduct (manufactured by Mitsui Chemicals, trade name) : Takenate D110N)
C / L: Trimethylolpropane / Tolylene diisocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name: Coronate L)
Peroxide: Benzoyl peroxide (peroxide-based cross-linking agent, manufactured by NOF CORPORATION, trade name: NOF BMT)

[evaluation]
<Measurement of weight average molecular weight (Mw) of (meth) acrylic polymer>
The weight average molecular weight (Mw) of the obtained (meth) acrylic polymer was measured by GPC (gel permeation chromatography).
-Analyzer: HLC-8120GPC manufactured by Tosoh Corporation
-Column: Tosoh, G7000H _XL + GMH _XL + GMH _XL
-Column size: 7.8 mm φ x 30 cm each 90 cm in total
-Column temperature: 40 ° C
・ Flow rate: 0.8 ml / min
・ Injection amount: 100 μl
・ Eluent: Tetrahydrofuran ・ Detector: Differential refractometer (RI)
・ Standard sample: Polystyrene

(Measurement of thickness)
The thicknesses of the polarizing film, the retardation film, the protective film, the optical laminate, the pressure-sensitive adhesive layer and the like were measured using a dial gauge (manufactured by Mitutoyo).

(Measurement of storage elastic modulus G'of the adhesive layer)
The separator was peeled off from the pressure-sensitive adhesive sheets of each Example and Comparative Example, and a plurality of pressure-sensitive adhesive sheets were laminated to prepare a test sample having a thickness of about 1.5 mm. This test sample is punched into a disk shape with a diameter of 7.9 mm, sandwiched between parallel plates, and dynamic viscoelasticity measurement is performed and measured under the following conditions using "Advanced Rheometric Expansion System (ARES)" manufactured by Rheometric Scientific. From the results, the storage elastic modulus G'of the pressure-sensitive adhesive layer at 25 ° C. was read.
(Measurement condition)
Deformation mode: Torsion measurement temperature: -40 ° C to 150 ° C
Temperature rise rate: 5 ° C / min

(Fold resistance test method)
FIG. 5 shows a schematic view of a 180 ° folding resistance tester (manufactured by Imoto Seisakusho). This device has a mechanism in which the chuck on one side repeatedly bends 180 ° across the mandrel in a constant temperature bath, and the bending radius can be changed according to the diameter of the mandrel. The mechanism is such that the test is stopped when the film breaks. In the test, the 5 cm × 15 cm laminated body for a flexible image display device obtained in each Example and Comparative Example was set in the device, and the temperature was 25 ° C., the bending angle was 180 °, the bending radius was 3 mm, and the bending speed was 1 second / time. It was carried out under the condition of a weight of 100 g. The folding resistance was evaluated by the number of times until the laminated body for the flexible image display device was broken. Here, when the number of bendings reached 200,000, the test was terminated.
As a measurement (evaluation) method, when the first pressure-sensitive adhesive layer side of the laminated body for a flexible image display device is turned inside (concave side) and bent (only in Example 1), the first pressure-sensitive adhesive layer is outside. Two types of bending (bending) directions were evaluated when bending on the (convex side).
<Presence / absence of breakage>
◯: No break △: Slight break at the end of the bent part (no problem in practical use)
×: There is a break in the entire surface of the bent part (there is a practical problem)
<Presence / absence of appearance (scratch)>
○: No creases or peeling, etc. △: Slight creases, peeling, etc. are confirmed at the bent part (no problem in practical use)
×: Folding, peeling, etc. are confirmed on the entire surface of the bent part (there is a problem in practical use).

From the evaluation results in Table 4, it was confirmed by the fold resistance test that in all the examples, there was no practical problem in folds and peeling. That is, in the laminated body for the flexible image cover device of each embodiment, by reducing the thickness of the polarizing film to be used and using a plurality of specific adhesive layers, it is possible to cause peeling or breakage even with repeated bending. It was confirmed that a laminated body for a flexible image display device having excellent bending resistance and adhesiveness could be obtained.

On the other hand, in Comparative Example 1, it was confirmed that the bending resistance was inferior because the thickness of the polarizing film exceeded a desired range. Further, in Comparative Examples 2 and 3, the storage elastic modulus G'at 25 ° C. of the outermost pressure-sensitive adhesive layer on the convex side when bent was larger than the storage elastic modulus G'at 25 ° C. of the other pressure-sensitive adhesive layer. Therefore, it was confirmed that the bending resistance and the adhesiveness were inferior due to breakage and peeling.

Although the present invention has been described above with reference to the drawings for a specific embodiment, the present invention can be modified in many ways other than the configurations shown and described. Therefore, the present invention is not limited to the configurations illustrated and described, and its scope should be defined only by the appended claims and their equivalents.

1 Polarizing film 2 Protective film 2-1 Protective film 2-2 Protective film 3 Phase difference layer 4-1 Transparent conductive film 4-2 Transparent conductive film 5-1 Base film 5-2 Base film 6 Transparent conductive layer 6- 1 Transparent conductive layer 6-2 Transparent conductive layer 7 Spacer 8 Transparent substrate 8-1 Transparent substrate (PET film)
8-2 Transparent substrate (PET film)
9 Base material (PI film)
10 Organic EL display panel 10-1 Organic EL display panel (with touch sensor)
11 Laminate for flexible image display device (laminate for organic EL display device)
12 Adhesive layer 12-1 First adhesive layer 12-2 Second adhesive layer 12-3 Third adhesive layer 13 Decorative printing film 20 Optical laminate 30 Touch panel 40 Window 100 Flexible image display device ( Organic EL display device)

Claims (11)

A laminate for a flexible image display device comprising a plurality of pressure-sensitive adhesive layers and at least an optical film containing a polarizing film.
The thickness of the polarizing film is 20 μm or less, and the thickness is 20 μm or less.
Of the plurality of pressure-sensitive adhesive layers, the storage elastic modulus G'at 25 ° C. of the outermost pressure-sensitive adhesive layer on the convex side when the laminate is bent is the storage elastic modulus G'at 25 ° C. of the other pressure-sensitive adhesive layer. A laminated body for a flexible image display device, which is substantially the same as or smaller than'. The optical film has a polarizing film, a protective film of a transparent resin material on the first surface of the polarizing film, and a retardation film on a second surface different from the first surface of the polarizing film. The laminate for a flexible image display device according to claim 1, wherein the laminate is an optical laminate including the above. The second aspect of the present invention, wherein the first pressure-sensitive adhesive layer is arranged on the side opposite to the surface in contact with the polarizing film with respect to the protective film among the plurality of pressure-sensitive adhesive layers. Laminated body for flexible image display device. 2. 3. The laminated body for a flexible image display device according to 3. The flexibility according to claim 4, wherein the transparent conductive layer constituting the touch sensor is arranged on the side opposite to the surface in contact with the retardation film with respect to the second pressure-sensitive adhesive layer. Laminated body for image display device. 5. The fifth aspect of the present invention is characterized in that the third pressure-sensitive adhesive layer is arranged on the side opposite to the surface in contact with the second pressure-sensitive adhesive layer with respect to the transparent conductive layer constituting the touch sensor. The above-mentioned laminate for a flexible image display device. The third or fourth aspect of the present invention, wherein the transparent conductive layer constituting the touch sensor is arranged on the side opposite to the surface in contact with the protective film with respect to the first pressure-sensitive adhesive layer. Laminated body for flexible image display device. Among the plurality of pressure-sensitive adhesive layers, a third pressure-sensitive adhesive layer is arranged on the side opposite to the surface in contact with the first pressure-sensitive adhesive layer with respect to the transparent conductive layer constituting the touch sensor. The laminated body for a flexible image display device according to claim 7. The laminate for a flexible image display device according to any one of claims 1 to 8, wherein the plurality of pressure-sensitive adhesive layers are formed from the same pressure-sensitive adhesive composition. The laminated body for a flexible image display device according to any one of claims 1 to 9 and an organic EL display panel are included.
A flexible image display device characterized in that the laminated body for the flexible image display device is arranged on the visual recognition side with respect to the organic EL display panel. The flexible image display device according to claim 10, wherein a window is arranged on the visual recognition side with respect to the laminated body for the flexible image display device.

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