TWI859806B - Laminated body, image display device using the same, and method for manufacturing the laminated body - Google Patents

Abstract

This project provides a thin laminate with excellent bonding strength between components.

The solution is as follows: the laminated body of the embodiment of the present invention comprises: a polarizing plate including a polarizer, a functional layer, a resin layer and an adhesive layer; the resin layer and the adhesive layer are arranged adjacent to each other; the resin layer comprises a resin having a glass transition temperature of 85°C or higher and a weight average molecular weight Mw of 50,000 or higher and less than 500,000, and an isocyanate compound; the isocyanate compound comprises a compound selected from toluene diisocyanate, diphenylmethane diisocyanate, stubyl diisocyanate, and stubyl diisocyanate. and at least one of its derivatives; the content of the aforementioned resin in the aforementioned resin layer is 50% by weight or more and 90% by weight or less, and the content of the aforementioned isocyanate compound in the aforementioned resin layer is 10% by weight or more and 50% by weight or less; the aforementioned adhesive layer is composed of a cured layer of the adhesive composition, and the octanol/water partition coefficient logPow calculated by the weighted average of the molar fractions of the monomer components contained in the aforementioned adhesive composition is 1.5 or more and 4.0 or less.

Description

Laminated body and image display device using the same, and method for manufacturing the laminated body

The present invention relates to a multilayer body and an image display device using the same.

In recent years, image display devices represented by liquid crystal display devices and electroluminescent (EL) display devices (e.g., organic EL display devices, inorganic EL display devices) are rapidly becoming popular. Polarizing plates are usually used in image display panels mounted on image display devices. Typically, laminates that integrate polarizing plates with functional layers such as phase difference layers are widely used (e.g., Patent Document 1). Recently, the demand for thinner image display devices has become stronger, and thus the thinning of the above-mentioned laminates has also been strongly demanded.

Existing technical literature Patent Literature

Patent document 1: Japanese Patent No. 3325560

As the above-mentioned laminated bodies become thinner, the adhesion between the components constituting the laminated bodies may not be sufficiently ensured.

The present invention is made in view of the above situation, and its main purpose is to provide a thin multilayer body with excellent adhesion between components.

1. The laminate of the embodiment of the present invention comprises: a polarizing plate including a polarizer, a functional layer, a resin layer and an adhesive layer disposed between the polarizing plate and the functional layer; the resin layer and the adhesive layer are disposed adjacent to each other; the resin layer comprises: a resin having a glass transition temperature of 85°C or higher and a weight average molecular weight Mw of 50,000 or higher and less than 500,000, and an isocyanate compound; the isocyanate compound comprises toluene diisocyanate, diphenylmethane diisocyanate, At least one of stubyl diisocyanate and its derivatives; the content of the aforementioned resin in the aforementioned resin layer is 50% by weight or more and 90% by weight or less, and the content of the aforementioned isocyanate compound in the aforementioned resin layer is 10% by weight or more and 50% by weight or less; the aforementioned adhesive layer is composed of a cured layer of the adhesive composition, and the octanol/water partition coefficient logPow calculated by the weighted average of the molar fractions of the monomer components contained in the aforementioned adhesive composition is 1.5 or more and 4.0 or less.

2. In the laminate as described in 1 above, the content of the monomer component having an octanol/water partition coefficient logPow of 0.0 or less may be 30 parts by weight or less relative to 100 parts by weight of the monomer component contained in the adhesive composition.

3. In the laminate of 1 or 2 above, the resin layer may further contain at least one of hexamethylene diisocyanate or its derivatives as the isocyanate compound.

4. In any of the laminates in 1 to 3 above, the thickness of the adhesive layer may be less than 3 μm.

5. In any of the laminates in 1 to 4 above, the thickness of the resin layer may be less than 1 μm.

6. In the laminated body of any one of 1 to 5 above, the resin layer can also be arranged adjacent to the polarizer.

7. In any of the above-mentioned laminates 1 to 6, the functional layer may also be a phase difference layer.

8. The image display device of the embodiment of the present invention has a multilayer body as described in any one of 1 to 7 above.

9. The method for manufacturing the laminate of the embodiment of the present invention comprises the following steps: coating a polarizing plate or a functional layer containing a polarizer with an organic solvent solution containing a resin and an isocyanate compound to form a resin layer; and bonding the functional layer or the polarizing plate to the resin layer through an adhesive composition; the glass transition temperature of the resin is above 85°C and the weight average molecular weight Mw is above 50,000 and less than 500,000; the isocyanate compound comprises a diisocyanate selected from At least one of toluene ester, diphenylmethane diisocyanate, stubyl diisocyanate and their derivatives; the content of the aforementioned resin in the aforementioned resin layer is 50% by weight or more and 90% by weight or less, the content of the aforementioned isocyanate compound in the aforementioned resin layer is 10% by weight or more and 50% by weight or less, and the octanol/water partition coefficient logPow calculated by the weighted average of the molar fractions of the monomer components contained in the aforementioned adhesive composition is 1.5 or more and 4.0 or less.

According to the implementation form of the present invention, a thin multilayer body with excellent adhesion between components can be obtained.

10: Polarizing plate

11: Polarizer

11a: First main surface

11b: Second main surface

12: Protective layer

20: Resin layer

30: Next is the agent layer

40: Functional layer

70: Organic EL panel body

71: Substrate

72: Upper structure layer

100: Layered body

200: Image display panel (organic EL panel)

Figure 1 is a cross-sectional view schematically showing the general structure of a laminated body in one embodiment of the present invention.

FIG2 is a cross-sectional view schematically showing the general structure of an image display panel in an embodiment of the present invention.

Figure 3 is a cross-sectional SEM observation photograph of Example 1.

Figure 4 is a cross-sectional SEM observation photograph of Comparative Example 1.

Hereinafter, the embodiments of the present invention will be described with reference to the attached drawings, but the present invention is not limited to such embodiments. In addition, the attached drawings are for the purpose of making the description clearer, so sometimes the width, thickness, shape, etc. of each part are schematically shown compared with the embodiments, which is only an example and does not limit the interpretation of the present invention.

(Definition of terms and symbols)

The definitions of terms and symbols in this manual are as follows.

(1) Refractive index (nx, ny, nz)

"nx" is the refractive index in the direction where the refractive index in the plane reaches the maximum (i.e., the slow axis direction), "ny" is the refractive index in the direction orthogonal to the slow axis in the plane (i.e., the fast axis direction), and "nz" is the refractive index in the thickness direction.

(2) In-plane phase difference (Re)

"Re(λ)" is the in-plane phase difference measured at 23°C using light of wavelength λnm. For example, "Re(550)" is the in-plane phase difference measured at 23°C using light of wavelength 550nm. For Re(λ), when the thickness of the layer (film) is set to d(nm), it is calculated by the formula: Re(λ)=(nx-ny)×d.

(3) Phase difference in thickness direction (Rth)

"Rth(λ)" is the phase difference in the thickness direction measured at 23°C using light with a wavelength of λnm. For example, "Rth(550)" is the phase difference in the thickness direction measured at 23°C using light with a wavelength of 550nm. For Rth(λ), when the thickness of the layer (film) is set to d(nm), it is calculated using the formula: Rth(λ)=(nx-nz)×d.

(4) Nz coefficient

The Nz coefficient is calculated by Nz=Rth/Re.

(5) Angle

When an angle is mentioned in this manual, the angle includes two components: clockwise and counterclockwise relative to the reference direction. Therefore, for example, "45°" means ±45°.

A. Laminated body

FIG1 is a cross-sectional view schematically showing the general structure of a laminate of an embodiment of the present invention. The laminate 100 has, from the top side of FIG1 , a polarizing plate 10, a resin layer 20, an adhesive layer 30, and a functional layer 40.

The polarizing plate 10 includes a polarizer 11 having a first main surface 11a and a second main surface 11b facing each other, and further includes a protective layer 12 disposed on the first main surface 11a side of the polarizer 11. In the example of the figure, no protective layer is disposed between the polarizer 11 and the resin layer 20, and the resin layer 20 is disposed adjacent to the polarizer 11. By omitting the protective layer, it is possible to help thin the laminate. The laminate 100 is generally disposed in an image display device so that the polarizer 11 is closer to the visual recognition side than the resin layer 20.

In the example of the figure, the polarizing plate 10 includes a polarizing element 11 and a protective layer 12 disposed on the first main surface 11a side of the polarizing element 11, and may further include a second protective layer disposed on the second main surface 11b side of the polarizing element 11. In addition, the polarizing plate 10 includes the polarizing element 11 and the protective layer 12, but the protective layer 12 may also be omitted.

In the example of the diagram, the polarizing plate 10, the resin layer 20, the adhesive layer 30 and the functional layer 40 are arranged in sequence, but it can also be different from the example of the diagram. The adhesive layer 30 can be arranged on the side of the polarizing plate 10, and the resin layer 20 can be arranged on the side of the functional layer 40.

The resin layer 20 and the adhesive layer 30 are arranged adjacent to each other. It is preferable that an interface is confirmed between the resin layer 20 and the adhesive layer 30. Alternatively, it is preferable that an intermediate layer including components derived from the resin layer 20 and components derived from the adhesive layer is not formed between the resin layer 20 and the adhesive layer 30. The intermediate layer can be formed, for example, by dissolving (miscible) a part of the resin layer in the adhesive composition forming the adhesive layer when the adhesive layer is formed. By adopting a state in which an interface is formed (no intermediate layer is formed), excellent adhesion to the resin layer can be obtained without damaging the function of the resin layer. The above-mentioned interface or intermediate layer can be confirmed, for example, by observation using a scanning electron microscope (SEM).

The functional layer 40 can be composed of any appropriate optical component. Typically, the functional layer 40 can function as a phase difference layer. At this time, the laminate 100 is sometimes referred to as a polarizing plate with a phase difference layer. By using an adhesive layer in the lamination of the resin layer and the functional layer or the polarizing plate, the thickness of the adhesive layer between the resin layer and the functional layer or the polarizing plate can be made very thin (for example, less than 5 μm), which can greatly contribute to the thinning of the laminate. In addition, the obtained laminate also has excellent bendability.

Although not shown, the laminate (polarizing plate with phase difference layer) may also have other functional layers. The type, characteristics, quantity, combination, configuration, etc. of other functional layers that the laminate may have may be appropriately set according to the purpose. For example, the resin layer 20 can reduce the impact of the polarizer 11 on other components, and the laminate may also have the resin layer. In addition, for example, the polarizing plate with phase difference layer may also have a conductive layer or an isotropic substrate with a conductive layer. The polarizing plate with phase difference layer having a conductive layer or an isotropic substrate with a conductive layer is suitable for, for example, a so-called internal touch panel type input display device in which a touch sensor is integrated inside the image display panel. As another example, the polarizing plate with phase difference layer can also have other phase difference layers. The optical properties (e.g., refractive index properties, in-plane phase difference, Nz coefficient, photoelastic coefficient), thickness, configuration, etc. of other phase difference layers can be appropriately set for visual purposes. As a specific example, other phase difference layers (representatively, layers that impart (elliptical) circular polarization function and layers that impart ultra-high phase difference) can be set on the viewing side of the polarizer to improve visibility when viewing through polarized sunglasses. By having the above layers, even when viewing the display screen through polarized lenses such as polarized sunglasses, excellent visibility can still be achieved, and it can also be appropriately applied to image display devices that can be used outdoors.

Each component constituting the laminate can be laminated through any appropriate adhesive layer. As specific examples of the adhesive layer, an adhesive layer and an adhesive layer can be cited. For example, the protective layer 12 is bonded to the polarizer 11 through an adhesive layer (preferably an active energy ray curing adhesive). The thickness of the adhesive layer is, for example, greater than 0.05 μm, preferably 0.4 μm to 3.0 μm, and more preferably 0.6 μm to 2.2 μm.

Although not shown, an adhesive layer may be provided on the side of the functional layer 40 where the polarizing plate 10 is not provided. By using the adhesive layer, for example, the laminate 100 may be attached to an image display panel contained in an image display device. The thickness of the adhesive layer is preferably 10μm to 20μm.

The laminate can be in the form of a single sheet or a strip. In this specification, "strip" refers to a long and thin shape that is sufficiently long relative to its width, for example, including a long and thin shape that is more than 10 times, preferably more than 20 times, the length relative to its width. The strip-shaped laminate can also be rolled into a roll.

B. Polarizing plate

The polarizing plate includes a polarizing element having a first main surface and a second main surface facing each other, and may further include a protective layer disposed on the first main surface side and/or a second protective layer disposed on the second main surface side.

B-1. Polarizer

The polarizer is typically made of a polyvinyl alcohol (PVA) resin film containing a dichroic substance. The thickness of the polarizer is preferably 1μm~8μm, more preferably 1μm~7μm, and more preferably 2μm~5μm. The above thickness can greatly help to reduce the thickness of the laminate, for example.

The boric acid content of the polarizer is preferably 10% by weight or more, preferably 13% by weight to 25% by weight. If the boric acid content of the polarizer is within the above range, the ease of curling adjustment during lamination can be well maintained by the multiplication effect with the iodine content described later, and the curling during heating can be well suppressed, and the appearance durability during heating can be improved. The boric acid content can be calculated, for example, by the neutralization method using the following formula in the form of the amount of boric acid contained in the polarizer per unit weight.

[Mathematical formula 1]

The iodine content of the polarizer is preferably 2% by weight or more, more preferably 2% by weight to 10% by weight. If the iodine content of the polarizer is within the above range, the easiness of curling adjustment during lamination can be well maintained, curling during heating can be well suppressed, and the appearance durability during heating can be improved. In this specification, "iodine content" refers to the amount of all iodine contained in the polarizer (PVA-based resin film). More specifically, iodine exists in the form of iodine ions ( ^I- ), iodine molecules ( _I2 ), polyiodine ions ( _I3- ^, _I5- ⁾ and the like in the polarizer, and the iodine content in this specification refers to the amount of iodine including all of these forms. The iodine content can be calculated, for example, by the calibration curve method of X-ray fluorescence analysis. In addition, polyiodine ions exist in the polarizer in the form of a PVA-iodine complex. By forming the complex, absorption dichroism can be exhibited in the wavelength range of visible light. Specifically, the complex of PVA and triiodide ions (PVA‧I ₃ ^- ) has an absorption peak near 470nm, and the complex of PVA and pentaiodide ions (PVA‧I ₅ ^- ) has an absorption peak near 600nm. As a result, polyiodine ions can absorb light in a wide range of visible light depending on their morphology. On the other hand, iodine ions (I ^- ) have an absorption peak near 230nm and do not substantially interfere with the absorption of visible light. Therefore, polyiodine ions that exist in the form of a complex with PVA can mainly interfere with the absorption performance of the polarizer.

The polarizer should preferably show absorption dichroism at any wavelength between 380nm and 780nm. The single transmittance Ts of the polarizer should be 40% to 48%, preferably 41% to 46%. The polarization degree P of the polarizer should be above 97.0%, preferably above 99.0%, and more preferably above 99.9%. The single transmittance is represented by the Y value after measurement and sensitivity correction using an ultraviolet-visible spectrophotometer. The polarization degree is represented by the parallel transmittance Tp and the orthogonal transmittance Tc obtained after measurement and sensitivity correction using an ultraviolet-visible spectrophotometer, and is obtained by the following formula.

Polarization degree (%) = {(Tp-Tc)/(Tp+Tc)} ^1/2 × 100

A polarizer can be typically produced using a laminate of two or more layers. As a specific example of a polarizer obtained using a laminate, there can be cited a polarizer obtained using a laminate of a resin substrate and a PVA-based resin layer coated on the resin substrate. A polarizer obtained by using a laminate of a resin substrate and a PVA-based resin layer coated on the resin substrate can be produced, for example, as follows: a PVA-based resin solution is coated on the resin substrate, and the PVA-based resin layer is formed on the resin substrate by drying, thereby obtaining a laminate of the resin substrate and the PVA-based resin layer; the laminate is stretched and dyed to make the PVA-based resin layer into a polarizer. Stretching typically includes immersing the laminate in a boric acid aqueous solution and stretching it. Furthermore, stretching may also include stretching the laminate in the air at a high temperature (for example, above 95° C.) before stretching in the boric acid aqueous solution, if necessary. The obtained resin substrate/polarizer laminate can be used directly (i.e., the resin substrate can be used as a protective layer for the polarizer), or the resin substrate can be peeled off from the resin substrate/polarizer laminate and any appropriate protective layer that meets the purpose can be used on the peeled area layer. The details of the manufacturing method of the polarizer are described in, for example, Japanese Patent Publication No. 2012-73580 and Japanese Patent No. 6470455. The entire contents of these publications are cited in this specification as reference.

The manufacturing method of the polarizer typically includes: forming a polyvinyl alcohol resin layer containing a halogenated substance and a polyvinyl alcohol resin on one side of a long thermoplastic resin substrate to form a laminate; and sequentially performing: an air-assisted stretching treatment, a dyeing treatment, an underwater stretching treatment, and a drying and shrinking treatment on the laminate, wherein the drying and shrinking treatment is to heat the laminate while conveying the laminate in the length direction so as to shrink the laminate in the width direction by more than 2%. Thus, a very thin polarizer with excellent optical properties and suppressed optical property deviation can be provided. That is, by introducing auxiliary stretching, even when PVA is coated on a thermoplastic resin, the crystallinity of PVA can be improved, and high optical properties can be achieved. In addition, the orientation of PVA can be improved in advance, so that when immersed in water in the subsequent dyeing step and stretching step, the problems such as reduction in orientation or dissolution of PVA can be prevented, and high optical properties can be achieved. Furthermore, when the PVA-based resin layer is immersed in liquid, the orientation disorder and reduction in orientation of the polyvinyl alcohol molecules can be suppressed compared to the case where the PVA-based resin layer does not contain halides. Thereby, the optical properties of the polarizer obtained by the treatment steps of immersing the laminate in liquid such as dyeing treatment and underwater stretching treatment will be improved. Furthermore, by using a dry shrinking process to shrink the laminate in the width direction, the optical properties can be improved.

B-2. Protective layer

烯系)、聚烯烴系、(甲基)丙烯酸系、乙酸酯系等透明樹脂等。又，也可舉出(甲基)丙烯酸系、胺甲酸乙酯系、(甲基)丙烯酸系胺甲酸乙酯系、環氧系、聚矽氧系等熱硬化型樹脂或紫外線硬化型樹脂等。此外，例如也可舉出矽氧烷系聚合物等玻璃質系聚合物。又，亦可使用日本專利特開2001-343529號公報(WO01/37007)中記載的聚合物薄膜。作為該薄膜的材料，例如可使用含有在側鏈具有取代或未取代的醯亞胺基的熱塑性樹脂與在側鏈具有取代或未取代的苯基以及腈基的熱塑性樹脂的樹脂組成物，例如可舉出具有由異丁烯與N-甲基馬來醯亞胺構成之交替共聚物及丙烯腈‧苯乙烯共聚物的樹脂組成物。該聚合物薄膜例如可為上述樹脂組成物的擠製成形物。 The protective layer 12 and the second protective layer (not shown) are each formed of any appropriate film that can be used as a protective layer of the polarizer. Specific examples of the material of the main component of the film include cellulose resins such as triacetate cellulose (TAC), polyesters, polyvinyl alcohols, polycarbonates, polyamides, polyimides, polyether sulfones, polysulfones, polystyrenes, cyclic olefins (e.g., polydecene), and the like.

Examples of the present invention include transparent resins such as olefin resins, polyolefin resins, (meth) acrylic resins, and acetate resins. Examples of the present invention include thermosetting resins such as (meth) acrylic resins, urethane resins, (meth) acrylic urethane resins, epoxy resins, and polysilicone resins, or ultraviolet curing resins. Examples of the present invention include glassy polymers such as silicone polymers. Examples of the polymer films described in Japanese Patent Laid-Open No. 2001-343529 (WO01/37007) may also be used. As the material of the film, for example, a resin composition containing a thermoplastic resin having a substituted or unsubstituted imide group in the side chain and a thermoplastic resin having a substituted or unsubstituted phenyl group and a nitrile group in the side chain can be used, for example, a resin composition containing an alternating copolymer composed of isobutylene and N-methylmaleimide and an acrylonitrile-styrene copolymer can be cited. The polymer film can be, for example, an extruded product of the above resin composition.

The laminated body of the embodiment of the present invention is typically configured on the visual side of the image display device, and the protective layer 12 is configured on the visual side. Therefore, the protective layer 12 can be subjected to surface treatments such as hard coating (HC), anti-reflection, anti-sticking, and anti-glare treatments as needed. Furthermore/or, the protective layer 12 can be subjected to treatments to improve visibility when viewed through polarized sunglasses as needed (typically, (elliptical) circular polarization function and ultra-high phase difference are given). By implementing the above treatment, excellent visibility can be achieved even when viewing the display screen through polarized lenses such as polarized sunglasses, and it can also be suitable for application in image display devices that can be used outdoors.

The thickness of the protective layer is preferably 10μm~50μm, preferably 10μm~30μm. In addition, when surface treatment is performed, the thickness of the protective layer is the thickness including the thickness of the surface treatment layer.

In one embodiment, the second protective layer is preferably optically isotropic. In this specification, "optically isotropic" means that the in-plane phase difference Re(550) is 0nm~10nm, and the phase difference Rth(550) in the thickness direction is -10nm~+10nm.

C. Resin layer

The resin layer can reduce the impact that the polarizer may have on other components (it can have a barrier function). For example, the movement of iodine that may be contained in the polarizer can be suppressed, and when the laminate is mounted on an image display device, the corrosion of the metal components of the image display device can be significantly suppressed. The resin layer represents a solidified or thermosetting material of a coating film of an organic solvent solution with a resin on top. When it is configured as described above, the thickness can be made very thin (for example, less than 10 μm). The thickness of the resin layer is preferably less than 5 μm, more preferably less than 1 μm, and more preferably less than 0.7 μm. On the other hand, the thickness of the resin layer is preferably greater than 0.05 μm, more preferably greater than 0.08 μm, more preferably greater than 0.1 μm, and particularly preferably greater than 0.2 μm. Furthermore, in the case of the above-mentioned structure, a resin layer can be directly formed on the polarizing plate (polarizer) or the functional layer without passing through the bonding layer. The resin layer has lower moisture absorption and moisture permeability than a cured product of a water-based coating film such as an aqueous solution or a water dispersion, and therefore has the advantage of excellent humidification durability. As a result, a laminate can be obtained that can maintain optical properties and has excellent durability even in a high temperature and high humidity environment. In addition, the resin layer can suppress the adverse effects on the polarizing plate (polarizer) caused by ultraviolet irradiation, for example, compared with a cured product of an ultraviolet-curing resin. The resin layer is preferably a cured product of a coating film of an organic solvent solution of a resin. Compared with cured products, solidified products shrink less during film forming and do not contain residual monomers, etc., so the degradation of the film itself can be suppressed, and the adverse effects on the polarizing plate (polarizer) or functional layer caused by residual monomers can be suppressed.

The glass transition temperature (Tg) of the resin constituting the resin layer is 85°C or higher, and the weight average molecular weight (Mw) is 50,000 or higher. If Tg and Mw are within the above range, the resin layer is formed by a cured product or a thermosetting product of an organic solvent solution of the resin, and the migration of iodine that may be contained in the polarizer can be significantly suppressed. The Tg of the resin constituting the resin layer is preferably 90°C or higher, more preferably 100°C or higher, more preferably 110°C or higher, and particularly preferably 120°C or higher. The upper limit of Tg can be, for example, 200°C. In addition, the Mw of the resin constituting the resin layer is preferably 60,000 or more, more preferably 70,000 or more, and more preferably 80,000 or more. On the other hand, the Mw is preferably less than 500,000, preferably 400,000 or less, and more preferably 300,000 or less.

The resin layer contains an isocyanate compound in addition to the above-mentioned resin. Specifically, as the isocyanate compound, toluene diisocyanate, diphenylmethane diisocyanate, stubyl diisocyanate, and their derivatives (e.g., modified products, adducts) can be used. These can be used alone or in combination. By using the isocyanate compound, excellent adhesion to the polarizing plate (polarizer) can be achieved. As the isocyanate compound, in addition to the above, at least one of hexamethylene diisocyanate or its derivatives is preferably used. With the above-mentioned structure, the adhesion with the adhesive layer described later is more excellent.

The content of the resin in the resin layer is, for example, 50% by weight or more, 55% by weight or more, or 60% by weight or more. On the other hand, the content of the resin in the resin layer is, for example, 90% by weight or less, 85% by weight or less, or 80% by weight or less. The content of the isocyanate compound in the resin layer is, for example, 10% by weight or more, 15% by weight or more, or 20% by weight or more. On the other hand, the content of the isocyanate compound in the resin layer is, for example, 50% by weight or less, 45% by weight or less, or 40% by weight or less. Relative to 100 parts by weight of the isocyanate compound, the amount of hexamethylene diisocyanate and its derivatives is preferably 10 to 40 parts by weight.

As the resin constituting the resin layer, any appropriate thermoplastic resin or thermosetting resin can be used as long as it can form a cured product or a thermosetting product of a coating film of an organic solvent solution and has the Tg and Mw as described above. A thermoplastic resin is preferred. Examples of thermoplastic resins include epoxy resins and acrylic resins. Epoxy resins and acrylic resins can also be used in combination. Representative examples of epoxy resins and acrylic resins that can be used for the resin layer are described below.

<Epoxy resin>

As the epoxy resin, an epoxy resin having an aromatic epoxy group can be preferably used. By using an epoxy resin having an aromatic epoxy group as the epoxy resin, excellent adhesion to the polarizing plate (polarizer) can be achieved. Examples of the epoxy resin having an aromatic ring include bisphenol-type epoxy resins such as bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, and bisphenol S-type epoxy resin; novolac-type epoxy resins such as phenol novolac epoxy resin, cresol novolac epoxy resin, and hydroxybenzaldehyde phenol novolac epoxy resin; polyfunctional epoxy resins such as glyoxypropyl ether of tetrahydroxybenzylmethane, glyoxypropyl ether of tetrahydroxydiphenyl ketone, and epoxidized polyethylene phenol; naphthol-type epoxy resins, naphthalene-type epoxy resins, and biphenyl-type epoxy resins. Bisphenol A type epoxy resin, biphenyl type epoxy resin, and bisphenol F type epoxy resin can be preferably used. Only one type of epoxy resin can be used, or two or more types can be used in combination.

<Acrylic resin>

Acrylic resins typically contain repeating units derived from (meth)acrylate monomers having a linear or branched structure as the main component. In this specification, (meth)acrylic acid refers to acrylic acid and/or methacrylic acid. Acrylic resins may contain repeating units derived from any appropriate copolymer monomer that meets the purpose. Examples of copolymer monomers include carboxyl-containing monomers, hydroxyl-containing monomers, amide-containing monomers, aromatic ring-containing (meth)acrylates, and heterocyclic vinyl monomers. By appropriately setting the type, amount, combination, and copolymerization ratio of the monomer units, an acrylic resin having the above-mentioned predetermined Tg and Mw can be obtained.

<Boron-containing acrylic resin>

In one embodiment, the acrylic resin includes a copolymer (hereinafter sometimes referred to as a boron-containing acrylic resin) obtained by polymerizing a monomer mixture including more than 50 parts by weight of a (meth)acrylic monomer and more than 0 parts by weight and less than 50 parts by weight of a monomer represented by formula (1) (hereinafter sometimes referred to as a copolymer monomer):

(wherein, X represents a functional group comprising at least one reactive group selected from the group consisting of vinyl, (meth)acryl, styryl, (meth)acrylamide, vinyl ether, epoxy, cyclohexane, hydroxy, amino, aldehyde and carboxyl groups; ^R1 and ^R2 each independently represent a hydrogen atom, an aliphatic hydrocarbon group which may have a substituent, an aryl group which may have a substituent, or a heterocyclic group which may have a substituent; and ^R1 and ^R2 may be linked to each other to form a ring).

The boron-containing acrylic resin is represented by the repeating unit shown in the following formula. By polymerizing a monomer mixture containing a copolymer monomer shown in formula (1) and a (meth) acrylic monomer, the boron-containing acrylic resin has a boron-containing substituent in the side chain (for example, the repeating unit of k in the following formula). Thereby, excellent adhesion to the polarizing plate (polarizer) can be achieved. The boron-containing substituent can be included in the boron-containing acrylic resin continuously (that is, in a block form) or randomly.

(wherein, R ⁶ represents an arbitrary functional group, and j and k represent integers greater than 1).

<(Meth)acrylic acid monomer>

As the (meth)acrylic acid-based monomer, any appropriate (meth)acrylic acid-based monomer can be used. For example, (meth)acrylic acid ester monomers having a linear or branched chain structure and (meth)acrylic acid ester monomers having a ring structure can be cited.

Examples of (meth)acrylate monomers having a linear or branched structure include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tertiary butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and 2-hydroxyethyl (meth)acrylate. Methyl (meth)acrylate is preferably used. Only one (meth)acrylate monomer may be used, or two or more may be used in combination.

酯、(甲基)丙烯酸1-金剛烷基酯、(甲基)丙烯酸二環戊烯酯、(甲基)丙烯酸二環戊烯基氧基乙酯、(甲基)丙烯酸二環戊酯、(甲基)丙烯酸聯苯酯、(甲基)丙烯酸鄰聯苯氧基乙酯、(甲基)丙烯酸鄰聯苯氧基乙氧基乙基酯、丙烯酸間聯苯氧基乙酯、(甲基)丙烯酸對聯苯氧基乙酯、(甲基)丙烯酸鄰聯苯氧基-2-羥丙酯、(甲基)丙烯酸對聯苯氧基-2-羥丙酯、(甲基)丙烯酸間聯苯氧基-2-羥丙酯、N-(甲基)丙烯醯基氧基乙基-鄰聯苯=胺甲酸酯、N-(甲基)丙烯醯基氧基乙基-對聯苯=胺甲酸酯、N-(甲基)丙烯醯基氧基乙基-間聯苯=胺甲酸酯、鄰苯基苯酚環氧丙基醚丙烯酸酯等含聯苯基單體、(甲基)丙烯酸聯三苯酯、(甲基)丙烯酸鄰聯三苯氧基乙酯等。宜可使用(甲基)丙烯酸1-金剛烷基酯、(甲基)丙烯酸二環戊酯。藉由使用該等單體，可獲得玻璃轉移溫度高的聚合物。該等單體可僅使用1種，亦可組合2種以上來使用。 Examples of the (meth)acrylate monomer having a ring structure include cyclohexyl (meth)acrylate, benzyl (meth)acrylate, isobutyl (meth)acrylate, and

Ester, 1-adamantyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, dicyclopentyl (meth)acrylate, biphenyl (meth)acrylate, o-biphenyloxyethyl (meth)acrylate, o-biphenyloxyethoxyethyl (meth)acrylate, m-biphenyloxyethyl acrylate, p-biphenyloxyethyl (meth)acrylate, o-biphenyloxy-2-hydroxypropyl (meth)acrylate, Biphenyl monomers such as p-biphenyloxy-2-hydroxypropyl (meth)acrylate, m-biphenyloxy-2-hydroxypropyl (meth)acrylate, N-(meth)acryloyloxyethyl-o-biphenyl=carbamate, N-(meth)acryloyloxyethyl-p-biphenyl=carbamate, N-(meth)acryloyloxyethyl-m-biphenyl=carbamate, o-phenylphenol epoxypropyl ether acrylate, triphenyl (meth)acrylate, o-triphenoxyethyl (meth)acrylate, etc. can be preferably used. 1-Adamantyl (meth)acrylate and dicyclopentyl (meth)acrylate can be used. By using these monomers, a polymer with a high glass transition temperature can be obtained. These monomers can be used alone or in combination of two or more.

In addition to the above-mentioned (meth)acrylate monomers, silsesquioxane compounds having (meth)acryloyl groups can also be used. By using silsesquioxane compounds, acrylic polymers with high glass transition temperatures can be obtained. Silsesquioxane compounds are known to have various skeleton structures, such as cage structures, ladder structures, random structures, etc. Silsesquioxane compounds may have only one of these structures, or may have two or more. Silsesquioxane compounds may be used alone, or in combination of two or more.

As silsesquioxane compounds containing (meth)acryl groups, for example, MAC grade and AC grade of the SQ series of Toagosei Co., Ltd. can be used. MAC grade is a silsesquioxane compound containing a methacryl group, and specifically, for example, MAC-SQ TM-100, MAC-SQ SI-20, MAC-SQ HDM, etc. AC grade is a silsesquioxane compound containing an acryl group, and specifically, for example, AC-SQ TA-100, AC-SQ SI-20, etc. can be cited.

Use more than 50 parts by weight of (meth)acrylic acid monomers relative to 100 parts by weight of the monomer mixture.

<Comonomer>

As a comonomer, the monomer represented by the above formula (1) can be used. By using the comonomer, a boron-containing substituent is introduced into the side chain of the obtained polymer. The comonomer can be used alone or in combination of two or more.

As the aliphatic alkyl group in the above formula (1), there can be mentioned a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent, a cyclic alkyl group having 3 to 20 carbon atoms which may have a substituent, and an alkenyl group having 2 to 20 carbon atoms. As the above aryl group, there can be mentioned a phenyl group having 6 to 20 carbon atoms which may have a substituent, a naphthyl group having 10 to 20 carbon atoms which may have a substituent, and the like. As the heterocyclic group, there can be mentioned a 5-membered cyclic group or a 6-membered cyclic group containing at least one heteroatom which may have a substituent. In addition, ^R1 and ^R2 may be linked to each other to form a ring. ^R1 and ^R2 are preferably hydrogen atoms or linear or branched alkyl groups having 1 to 3 carbon atoms, and are more preferably hydrogen atoms.

The reactive group contained in the functional group represented by X is at least one selected from the group consisting of vinyl, (meth)acryl, styryl, (meth)acrylamide, vinyl ether, epoxy, cyclobutylene, hydroxyl, amine, aldehyde and carboxyl. Ideally, the reactive group is (meth)acryl and/or (meth)acrylamide. By having such reactive groups, excellent adhesion to the polarizing plate (polarizer) can be achieved.

In one embodiment, the functional group represented by X is preferably a functional group represented by Z-Y-. Here, Z represents a functional group including at least one reactive group selected from the group consisting of vinyl, (meth)acryl, styryl, (meth)acrylamide, vinyl ether, epoxy, cyclohexane, hydroxy, amino, aldehyde and carboxyl, and Y represents a phenyl group or an alkyl group.

Specifically, the following compounds can be used as copolymer monomers.

The copolymer monomer is used in an amount greater than 0 weight part and less than 50 weight parts relative to 100 weight parts of the monomer mixture. It is preferably greater than 0.01 weight part and less than 50 weight parts, more preferably 0.05 weight part to 20 weight parts, more preferably 0.1 weight part to 10 weight parts, and particularly preferably 0.5 weight part to 5 weight parts.

<Acrylic resin containing lactone ring, etc.>

In another embodiment, the acrylic resin has a repeating unit containing a ring structure selected from a lactone ring unit, a glutaric anhydride unit, a glutarimide unit, a maleic anhydride unit, and a maleimide (N-substituted maleimide) unit. The repeating unit containing a ring structure may contain only one type in the repeating unit of the acrylic resin, or may contain two or more types.

The lactone ring unit is preferably represented by the following general formula (2):

In the general formula (2), R ² , R ³ and R ⁴ each independently represent a hydrogen atom or an organic residue having 1 to 20 carbon atoms. In addition, the organic residue may also contain an oxygen atom. The acrylic resin may contain only a single lactone ring unit, or may contain a plurality of lactone ring units in which R ² , R ³ and R ⁴ in the general formula (2) are different. Acrylic resins having lactone ring units are described in, for example, Japanese Patent Publication No. 2008-181078, and the description of the publication is cited in this specification as a reference.

The glutarimide unit is preferably represented by the following general formula (3):

In the general formula (3), R ¹¹ and R ¹² each independently represent hydrogen or an alkyl group having 1 to 8 carbon atoms, and R ¹³ represents an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, or an aryl group having 6 to 10 carbon atoms. In the general formula (3), preferably, R ¹¹ and R ¹² each independently represent hydrogen or a methyl group, and R ¹³ represents hydrogen, a methyl group, a butyl group, or a cyclohexyl group. More preferably, R ¹¹ represents a methyl group, R ¹² represents hydrogen, and R ¹³ represents a methyl group. The acrylic resin may contain only a single pentylimide unit, or may contain a plurality of pentylimide units in which R ¹¹ , R ¹² , and R ¹³ in the general formula (3) are different. Acrylic resins having a glutarimide unit are described, for example, in Japanese Patent Laid-Open Nos. 2006-309033, 2006-317560, 2006-328334, 2006-337491, 2006-337492, 2006-337493, and 2006-337569, and the descriptions of these publications are incorporated herein by reference. In addition, regarding the glutaric anhydride unit, the above description regarding the glutarimide unit applies except that the nitrogen atom substituted by ^R in the above general formula (3) is an oxygen atom.

Regarding maleic anhydride units and maleimide (N-substituted maleimide) units, their structures are determined by their names, so detailed descriptions are omitted.

The content ratio of the repeating unit containing a ring structure in the acrylic resin is preferably 1 mol% to 50 mol%, more preferably 10 mol% to 40 mol%, and more preferably 20 mol% to 30 mol%. In addition, the acrylic resin contains the repeating unit derived from the above-mentioned (meth) acrylic monomer as the main repeating unit.

The resin layer is typically formed by applying an organic solvent solution of the above-mentioned resin to form a coating film and curing or heat-curing the obtained coating film. As an organic solvent, any appropriate organic solvent that can dissolve or evenly disperse the above-mentioned resin can be used. Specific examples of organic solvents include ethyl acetate, toluene, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), cyclopentanone, and cyclohexanone. The resin concentration of the solution is preferably 3 parts by weight to 20 parts by weight relative to 100 parts by weight of the solvent. If it is the above-mentioned resin concentration, a uniform coating film can be formed.

The solution can be applied to any suitable substrate, preferably to a polarizing plate (polarizer) or a functional layer. When the solution is applied to the substrate, it means that the resin layer formed on the substrate is transferred to the polarizing plate (polarizer) or the functional layer. The transfer is performed through a bonding layer, so the resin layer can be directly formed by applying the solution to the polarizing plate (polarizer) or the functional layer, and the bonding layer can be omitted. As a method for applying the solution, any suitable method can be adopted. As specific examples, there are roller coating, spin coating, wire rod coating, dip coating, die coating, curtain coating, spray coating, knife coating (comma coating, etc.).

The heating temperature for curing or heat curing of the above-mentioned coating film is preferably below 100°C, preferably 50°C to 70°C. If the heating temperature is within the above range, adverse effects on the polarizer can be prevented. The heating time can be, for example, 1 minute to 10 minutes.

The resin layer (substantially an organic solvent solution of the above resin) may contain any appropriate additives depending on the purpose. Specific examples of additives include ultraviolet absorbers; levelers; antioxidants such as hindered phenol, phosphorus, and sulfur; stabilizers such as light stabilizers, weather stabilizers, and heat stabilizers; reinforcing materials such as glass fibers and carbon fibers; near-infrared absorbers; tris(dibromopropyl) phosphate, tris(ene) phosphate, and the like. Flame retardants such as propyl ester and antimony oxide; antistatic agents such as anionic, cationic and nonionic surfactants; colorants such as inorganic pigments, organic pigments and dyes; organic fillers or inorganic fillers; resin modifiers; organic fillers or inorganic fillers; plasticizers; lubricants; antistatic agents; flame retardants, etc. The type, quantity, combination and addition amount of additives can be appropriately set according to the purpose.

D. Then the agent layer

The above-mentioned adhesive layer is preferably composed of a cured adhesive composition. Specifically, it is preferably composed of a cured adhesive composition (radical polymerization curing adhesive composition) such as electron beam curing, ultraviolet curing, and visible light curing. The thickness of the adhesive layer is preferably 3μm or less, and preferably 2μm or less. The use of the above thickness can greatly contribute to the thinning of the laminate. In addition, the impact on other components caused by the shrinkage that occurs when the adhesive layer is formed by the adhesive composition can be reduced. For example, from the perspective of obtaining excellent adhesion, the thickness of the adhesive layer is preferably 0.05μm or more, preferably 0.5μm or more, and more preferably 1μm or more.

As monomer components constituting the radical polymerization curable adhesive composition, for example, compounds having radical polymerizable functional groups with carbon-carbon double bonds such as (meth)acryl and vinyl can be cited. Such monomer components can use any of monofunctional radical polymerizable compounds or polyfunctional radical polymerizable compounds having two or more polymerizable functional groups. Moreover, such radical polymerizable compounds can be used alone or in combination of two or more. In addition, in the present invention, (meth)acryl refers to acryl and/or methacryl.

The octanol/water partition coefficient logPow calculated by the weighted average of the molar fraction of the monomer components contained in the above-mentioned adhesive composition is, for example, greater than 1.0 and less than 4.0, preferably greater than 1.5, may be greater than 2.0, and may be greater than 2.5. By using the adhesive composition, excellent adhesion to the resin layer can be obtained. Moreover, the functions (e.g., barrier function) of the resin layer can be maintained. By using the adhesive composition, the formation of the above-mentioned intermediate layer (miscible layer) can be suppressed. Here, the octanol/water partition coefficient (logPow) is an indicator of the lipophilicity of a substance, and refers to the logarithmic value of the octanol/water partition coefficient. A high logPow can mean lipophilicity. logPow can be measured (for example, by the flask penetration method described in JIS-Z-7260), but can also be calculated. In this manual, the octanol/water partition coefficient (logPow) refers to the value calculated using Chem Draw Ultra manufactured by CambridgeSoft. For the resin layer of the cured or thermosetting material of the coating film of the organic solvent solution of the resin, the use of a highly hydrophobic adhesive composition can inhibit the formation of the above-mentioned intermediate layer and obtain excellent adhesion, which is an unexpected excellent effect.

酯(商品名「LIGHT ACRYLATE IB-XA」，共榮社化學公司製，LogPow；3.27)、羥基三甲基乙酸新戊二醇丙烯酸酯加成物(商品名「LIGHT ACRYLATE HPP-A」，共榮社化學公司製，LogPow；3.35)、1,9-壬二醇二丙烯酸酯(商品名「LIGHT ACRYLATE 1,9ND-A」，共榮社化學公司製，LogPow；3.68)、鄰苯基苯酚EO改質丙烯酸酯(商品名「FANCRYL FA-301A」，日立化成公司製，LogPow；3.98)、2-乙基己基氧雜環丁烷(商品名「Aron Oxetane OXT-212」，東亞合成公司製，LogPow；4.24)、雙酚-A-二環氧丙基醚(商品名「JER828」，三菱化學公司 製，LogPow；4.76)、雙酚A EO 6莫耳改質二丙烯酸酯(商品名「FA-326A」，日立化成公司製，LogPow；4.84)、雙酚A EO 4莫耳改質二丙烯酸酯(商品名「FA-324A」，日立化成公司製，LogPow；5.15)、雙酚A PO 2莫耳改質二丙烯酸酯(商品名「FA-P320A」，日立化成公司製，LogPow；6.10)、雙酚A PO 3莫耳改質二丙烯酸酯(商品名「FA-P323A」，日立化成公司製，LogPow；6.26)、雙酚A PO 4莫耳改質二丙烯酸酯(商品名「FA-P324A」，日立化成公司製，LogPow；6.43)、丙烯酸月桂酯(商品名「LIGHT ACRYLATE L-A」，共榮社化學公司製，LogPow；6)、丙烯酸異硬脂酯(商品名「ISTA」)，大阪有機化學工業公司製；LogPow；7.46)、苯氧基二乙二醇丙烯酸酯(商品名「P2HA」，共榮社化學公司製，LogPow；2.15)、丙烯酸2-羥基-3-苯氧丙酯(商品名「ARONIX M-5700」，東亞合成公司製，LogPow；1.17)。 The logPow of the radical polymerizable compound is shown below. For example, hydroxyethyl acrylamide (trade name "HEAA", manufactured by Kojin Co., Ltd., LogPow: -0.56), diethyl acrylamide (trade name "DEAA", manufactured by KJ Chemicals Corporation, LogPow: 1.69), unsaturated fatty acid hydroxy alkyl ester modified ε-caprolactone (trade name "PLACCEL FA1DDM", manufactured by Daicel Corporation, LogPow: 1.06), N-vinyl formamide (trade name "BEAMSET 770", manufactured by Arakawa Chemicals Co., Ltd., LogPow: -0.25), acrylamide isoflurane (trade name "ACMO", manufactured by Kojin Co., Ltd., LogPow: -0.20), γ-butyrolactone acrylate (trade name "GBLA", manufactured by Osaka Organic Chemical Industry Co., Ltd., LogPow: 0.19), acrylic acid dimer (trade name "β-CEA", manufactured by Daicel Corporation, LogPow: 0.19), and 1,2-dimethoxy-1,2-dimethoxy-1,2-dimethoxy-1,2-dimethoxy-1,2-dimethoxy-1,2-dimethoxy-1,2-dimethoxy-1,2-dimethoxy-1,2-dimethoxy-1,2-dimethoxy-1,2-dimethoxy-1,2-dimethoxy-1,2-dimethoxy-1,2-dimethoxy-1,2-dimethoxy-1 Corporation, LogPow; 0.2), N-vinyl pyrrolidone (trade name "NVP", manufactured by Nippon Catalyst Co., Ltd., LogPow; 0.24), acetyl acetoxyethyl methacrylate (trade name "AAEM", manufactured by Nippon Synthetic Chemical Co., Ltd., LogPow; 0.27), 2-hydroxyethyl acrylate (trade name "HEA", manufactured by Osaka Organic Chemical Industry Co., Ltd., LogPow; 0.28), glycidyl methacrylate (trade name "Light Ester G", manufactured by Kyoeisha Chemicals, LogPow; 0.57), dimethyl acrylamide (trade name "DMAA", manufactured by Kojin Co., LogPow; 0.58), tetrahydrofurfuryl alcohol acrylate polymer (trade name "VISCOAT#150D", manufactured by Osaka Organic Chemicals, LogPow; 0.60), 4-hydroxybutyl acrylate (trade name "4-HBA", manufactured by Osaka Organic Chemicals, LogPow; 0.68), acrylic acid (trade name "acrylic acid", manufactured by Mitsubishi Chemical, LogPow; 0.69), triethylene glycol diacrylate (trade name "LIGHT ACRYLATE 3EG-A", manufactured by Kyoeisha Chemicals, LogPow; 0.72), PEG400# diacrylate (trade name "LIGHT ACRYLATE 9EG-A", manufactured by Kyoeisha Chemical Co., Ltd., LogPow: -0.1), polypropylene glycol diacrylate (trade name "ARONIX M-220", manufactured by Toagosei Co., Ltd., LogPow: 1.68), dicyclopentenyl acrylate (trade name "FANCRYL FA-511AS", manufactured by Hitachi Chemical Co., Ltd., LogPow: 2.26), butyl acrylate (trade name "butyl acrylate", manufactured by Mitsubishi Chemical Co., Ltd., LogPow: 2.35), 1,6-hexanediol diacrylate (trade name "LIGHT ACRYLATE 1.6HX-A", manufactured by Kyoeisha Chemical Co., Ltd., LogPow: 2.43), dicyclopentanyl acrylate (trade name "FANCRYL FA-513AS", manufactured by Hitachi Chemical Co., Ltd., LogPow: 2.58), dihydroxymethyl-tricyclodecane diacrylate (trade name "LIGHT ACRYLATE DCP-A", manufactured by Kyoeisha Chemical Co., Ltd., LogPow; 305), acrylic acid

Ester (trade name "LIGHT ACRYLATE IB-XA", manufactured by Kyoeisha Chemical Co., Ltd., LogPow: 3.27), hydroxytrimethylacetate neopentyl glycol acrylate adduct (trade name "LIGHT ACRYLATE HPP-A", manufactured by Kyoeisha Chemical Co., Ltd., LogPow: 3.35), 1,9-nonanediol diacrylate (trade name "LIGHT ACRYLATE 1,9ND-A", manufactured by Kyoeisha Chemical Co., Ltd., LogPow: 3.68), o-phenylphenol EO modified acrylate (trade name "FANCRYL FA-301A", manufactured by Hitachi Chemical Co., Ltd., LogPow: 3.98), 2-ethylhexyloxycyclobutane (trade name "Aron Oxetane OXT-212", manufactured by Toagosei Co., Ltd., LogPow; 4.24), bisphenol-A-diepoxypropyl ether (trade name "JER828", manufactured by Mitsubishi Chemical Co., Ltd., LogPow; 4.76), bisphenol A EO 6 mol modified diacrylate (trade name "FA-326A", manufactured by Hitachi Chemical Co., Ltd., LogPow; 4.84), bisphenol A EO 4 mol modified diacrylate (trade name "FA-324A", manufactured by Hitachi Chemical Co., Ltd., LogPow; 5.15), bisphenol A PO 2 mol modified diacrylate (trade name "FA-P320A", manufactured by Hitachi Chemical Co., Ltd., LogPow; 6.10), bisphenol A PO 3 mol modified diacrylate (trade name "FA-P323A", manufactured by Hitachi Chemical Co., Ltd., LogPow; 6.26), bisphenol A PO 4 mol modified diacrylate (trade name "FA-P324A", manufactured by Hitachi Chemical Co., Ltd., LogPow; 6.43), lauryl acrylate (trade name "LIGHT ACRYLATE LA", manufactured by Kyoeisha Chemical Co., Ltd., LogPow; 6), isostearyl acrylate (trade name "ISTA"), manufactured by Osaka Organic Chemical Co., Ltd.; LogPow; 7.46), phenoxydiethylene glycol acrylate (trade name "P2HA", manufactured by Kyoeisha Chemical Co., Ltd., LogPow; 2.15), 2-hydroxy-3-phenoxypropyl acrylate (trade name "ARONIX M-5700", manufactured by Toagosei Co., Ltd., LogPow; 1.17).

When the total amount of monomer components contained in the adhesive composition is set to 100 parts by weight, the content of monomer components with an octanol/water partition coefficient logPow of 0.0 or less may also be 30 parts by weight or less. When the total amount of monomer components contained in the adhesive composition is set to 100 parts by weight, the content of monomer components with an octanol/water partition coefficient logPow of 2.0 or more may also be 40 parts by weight or more.

Regarding the amount of polymerization initiator that can be used during curing, when the total amount of the adhesive composition is set to 100% by weight, it is, for example, 0.05% by weight to 10% by weight.

The adhesive composition is hardened, for example, by irradiating the coating film of the adhesive composition with active energy rays (e.g., visible light, ultraviolet light, electron beam).

E. Phase difference layer

The above-mentioned phase difference layer can be a single layer or can have a laminated structure of two or more layers. The phase difference layer can also be composed of any appropriate material. Specifically, the phase difference layer can be a directional solidification layer of a liquid crystal compound, can be a stretched film (resin film), or can be a combination of these. The thickness of the phase difference layer is, for example, greater than 1 μm and less than 50 μm. In one embodiment, the thickness of the phase difference layer is preferably less than 10 μm, more preferably less than 8 μm, and more preferably less than 6 μm. According to the embodiment of the present invention, even when the extremely thin phase difference layer is used, for example, when the laminate is mounted on an image display device, the corrosion of the metal components of the image display device can be significantly suppressed. In addition, when the phase difference layer has a layered structure, the "thickness of the phase difference layer" refers to the total thickness of each phase difference layer. Specifically, the "thickness of the phase difference layer" does not include the thickness of the connecting layer.

As the above-mentioned phase difference layer, for example, an oriented solidified layer of a liquid crystal compound (liquid crystal oriented solidified layer) can be used. By using a liquid crystal compound, for example, the difference between nx and ny of the obtained phase difference layer can be significantly increased compared to non-liquid crystal materials, so the thickness of the phase difference layer used to obtain the desired in-plane phase difference can be significantly reduced. Therefore, a significant thinning of the polarizing plate with a phase difference layer can be achieved. In this specification, "oriented solidified layer" refers to a layer in which the liquid crystal compound is oriented along a predetermined direction in the layer and its oriented state is fixed. In addition, "oriented solidified layer" is a concept that includes an oriented solidified layer obtained by curing a liquid crystal monomer as described later. In the phase difference layer, the rod-shaped liquid crystal compound on the representative is oriented in a state of being arranged in the slow axis direction of the phase difference layer (oriented along the plane).

The above-mentioned liquid crystal orientation solidification layer can be formed in the following manner: an orientation treatment is performed on the surface of a predetermined substrate, and a coating liquid containing a liquid crystal compound is applied to the surface to orient the liquid crystal compound in a direction corresponding to the above-mentioned orientation treatment, and the orientation state is fixed. As an orientation treatment, any appropriate orientation treatment can be adopted. Specifically, mechanical orientation treatment, physical orientation treatment, and chemical orientation treatment can be cited. As a specific example of mechanical orientation treatment, friction treatment and stretching treatment can be cited. As a specific example of physical orientation treatment, magnetic field orientation treatment and electric field orientation treatment can be cited. As a specific example of chemical orientation treatment, oblique evaporation method and light orientation treatment can be cited. The processing conditions of various orientation treatments can adopt any appropriate conditions depending on the purpose.

The orientation of the liquid crystal compound is carried out by treating it at a temperature that exhibits a liquid crystal phase according to the type of the liquid crystal compound. By carrying out the temperature treatment, the liquid crystal compound becomes a liquid crystal state, and the liquid crystal compound is oriented according to the orientation treatment direction of the substrate surface.

In one embodiment, the fixation of the orientation state is performed by cooling the liquid crystal compound that has been oriented as described above. When the liquid crystal compound is a polymerizable monomer or a crosslinking monomer, the fixation of the orientation state is performed by subjecting the liquid crystal compound that has been oriented as described above to a polymerization treatment or a crosslinking treatment.

Specific examples of liquid crystal compounds and details of the method for forming an oriented solidified layer are described in Japanese Patent Publication No. 2006-163343. This specification uses the description of the publication as a reference.

When the phase difference layer is a single layer, in one embodiment, the phase difference layer can function as a λ/4 plate. Specifically, the Re(550) of the phase difference layer is preferably 100nm~180nm, more preferably 110nm~170nm, and more preferably 110nm~160nm. The thickness of the phase difference layer can be adjusted to obtain the desired in-plane phase difference of the λ/4 plate. When the phase difference layer is the above-mentioned liquid crystal directional solidification layer, its thickness is, for example, 1.0μm~2.5μm. In this embodiment, the angle formed by the slow axis of the phase difference layer and the absorption axis of the polarizer is preferably 40°~50°, more preferably 42°~48°, and more preferably 44°~46°. Furthermore, the phase difference layer should preferably exhibit an inverse dispersion wavelength characteristic in which the phase difference value increases according to the wavelength of the measured light.

When the phase difference layer is a single layer, in another embodiment, the phase difference layer can function as a λ/2 plate. Specifically, the Re(550) of the phase difference layer is preferably 200nm~300nm, preferably 230nm~290nm, and more preferably 230nm~280nm. The thickness of the phase difference layer can be adjusted to obtain the desired in-plane phase difference of the λ/2 plate. When the phase difference layer is the above-mentioned liquid crystal directional solidification layer, its thickness is, for example, 2.0μm~4.0μm. In this embodiment, the angle formed by the slow axis of the phase difference layer and the absorption axis of the polarizer is preferably 10°~20°, preferably 12°~18°, and more preferably 12°~16°.

When the phase difference layer has a laminated structure, in one embodiment, the phase difference layer has a laminated structure in which a first phase difference layer (H layer) and a second phase difference layer (Q layer) are sequentially arranged from the polarizer side. The H layer can function as a λ/2 plate, and the Q layer can function as a λ/4 plate. Specifically, the Re (550) of the H layer is preferably 200nm~300nm, preferably 220nm~290nm, and more preferably 230nm~280nm; the Re (550) of the Q layer is preferably 100nm~180nm, preferably 110nm~170nm, and more preferably 110nm~150nm. The thickness of the H layer can be adjusted to obtain the desired in-plane phase difference of the λ/2 plate. When the H layer is the above-mentioned liquid crystal directional solidification layer, its thickness is, for example, 2.0μm~4.0μm. The thickness of the Q layer can be adjusted to obtain the desired in-plane phase difference of the λ/4 plate. When the Q layer is the above-mentioned liquid crystal directional solidification layer, its thickness is, for example, 1.0μm~2.5μm. In this embodiment, the angle formed by the slow axis of the H layer and the absorption axis of the polarizer is preferably 10°~20°, preferably 12°~18°, and more preferably 12°~16°; the angle formed by the slow axis of the Q layer and the absorption axis of the polarizer is preferably 70°~80°, preferably 72°~78°, and more preferably 72°~76°. In addition, the arrangement order of the H layer and the Q layer can be opposite, and the angle formed by the slow axis of the H layer and the absorption axis of the polarizer and the angle formed by the slow axis of the Q layer and the absorption axis of the polarizer can also be opposite. In addition, each layer (for example, the H layer and the Q layer) can display the reverse dispersion wavelength characteristics in which the phase difference value increases according to the wavelength of the measured light, can display the normal wavelength dispersion characteristics in which the phase difference value decreases according to the wavelength of the measured light, and can also display the flat wavelength dispersion characteristics in which the phase difference value does not basically change according to the wavelength of the measured light.

The refractive index characteristics of the phase difference layer (at least one layer when having a layered structure) represent the relationship of nx>ny=nz. In addition, "ny=nz" includes not only the case where ny and nz are completely equal, but also the case where they are substantially equal. Therefore, there are cases where ny>nz or ny<nz within the range that does not impair the effect of the present invention. The Nz coefficient of the phase difference layer is preferably 0.9~1.5, and more preferably 0.9~1.3.

As mentioned above, the phase difference layer is preferably a liquid crystal oriented solidification layer. As the above-mentioned liquid crystal compound, for example, a liquid crystal compound whose liquid crystal phase is a nematic phase (nematic liquid crystal) can be cited. As the above-mentioned liquid crystal compound, for example, a liquid crystal polymer or a liquid crystal monomer can be used. The liquid crystal performance mechanism of the liquid crystal compound can be lyotropic or thermotropic. The liquid crystal polymer and the liquid crystal monomer can be used alone or in combination.

When the liquid crystal compound is a liquid crystal monomer, the liquid crystal monomer is preferably a polymerizable monomer and a crosslinking monomer. This is because the orientation state of the liquid crystal monomer can be fixed by polymerizing or crosslinking (i.e., curing) the liquid crystal monomer. If the liquid crystal monomers are polymerized or crosslinked with each other after being oriented, the above-mentioned orientation state can be fixed. Here, a polymer is formed by polymerization, and a three-dimensional network structure is formed by crosslinking, and these are non-liquid crystal. Therefore, the phase difference layer formed will not undergo the transformation into a liquid crystal phase, a glass phase, or a crystalline phase due to temperature changes, which is unique to liquid crystal compounds. As a result, the phase difference layer becomes a phase difference layer with extremely excellent stability that is not affected by temperature changes.

The temperature range in which a liquid crystal monomer exhibits liquid crystallinity varies depending on its type. Specifically, the temperature range is preferably 40°C to 120°C, more preferably 50°C to 100°C, and most preferably 60°C to 90°C.

As the above-mentioned liquid crystal monomer, any appropriate liquid crystal monomer can be used. For example, polymerizable liquid crystal original compounds described in Japanese Patent Table 2002-533742 (WO00/37585), EP358208 (US5211877), EP66137 (US4388453), WO93/22397, EP0261712, DE19504224, DE4408171 and GB2280445 can be used. As specific examples of the polymerizable liquid crystal original compounds, for example, BASF's trade name LC242, Merck's trade name E7, and Wacker-Chem's trade name LC-Sillicon-CC3767 can be cited. As a liquid crystal monomer, a nematic liquid crystal monomer is preferred.

In another embodiment, the phase difference layer has a layered structure of a first phase difference layer that can function as a λ/4 plate and a second phase difference layer (so-called positive C plate) whose refractive index characteristics show the relationship nz>nx=ny from the polarizer side. The details of the λ/4 plate are as described above. In this embodiment, the angle formed by the slow axis of the first phase difference layer and the absorption axis of the polarizer is preferably 40°~50°, preferably 42°~48°, and more preferably 44°~46°. In addition, the first phase difference layer preferably shows an inverse dispersion wavelength characteristic in which the phase difference value increases according to the wavelength of the measured light.

The phase difference Rth(550) in the thickness direction of the positive C plate is preferably -50nm~-300nm, more preferably -70nm~-250nm, more preferably -90nm~-200nm, and particularly preferably -100nm~-180nm. Here, "nx=ny" includes not only the case where nx and ny are strictly equal, but also the case where nx and ny are substantially equal. The in-plane phase difference Re(550) of the positive C plate is, for example, less than 10nm.

The second phase difference layer having the refractive index characteristic of nz>nx=ny can be formed by any appropriate material, preferably by a film containing a liquid crystal material fixed to a homeotropic alignment. The liquid crystal material (liquid crystal compound) capable of homeotropic alignment can be a liquid crystal monomer or a liquid crystal polymer. As a specific example of the liquid crystal compound and the method for forming the phase difference layer, the liquid crystal compound and the method for forming the phase difference layer described in [0020] to [0028] of Japanese Patent Publication No. 2002-333642 can be cited. At this time, the thickness of the second phase difference layer is preferably 0.5μm to 5μm.

F. Image display device

The above-mentioned multilayer body can be applied to an image display device. Therefore, the image display device of the embodiment of the present invention has the above-mentioned multilayer body. As representative examples of image display devices, liquid crystal display devices and electroluminescent (EL) display devices (for example, organic EL display devices, inorganic EL display devices) can be cited.

FIG2 is a cross-sectional view schematically showing the general structure of an image display panel included in an image display device of an embodiment of the present invention, taking an organic EL display device as an example. The image display panel (organic EL panel) 200 has: an organic panel body 70 and a laminate 100 arranged on its viewing side. The laminate 100 is arranged so that the resin layer 20 is closer to the organic EL panel body 70 than the polarizer 11. The laminate 100 is attached to the organic EL panel body 70 by means of an adhesive layer (not shown).

The organic EL panel body 70 has a substrate 71 and an upper structural layer 72. The upper structural layer 72 includes: a circuit layer including a thin film transistor (TFT), an organic light emitting diode (OLED), a sealing film for sealing the OLED, etc. The upper structural layer 72 may include metal components (e.g., electrodes, sensors, wiring, metal layers). For example, when a flexible substrate (e.g., a resin substrate) is used as the substrate 71, the resulting organic EL display device can be bent, flexed, bent, rolled, etc. The multilayer body of the embodiment of the present invention can have excellent flexibility and bending durability, and therefore can also be suitably used in the image display device.

Implementation example

The present invention is described in detail below by way of examples, but the present invention is not limited to these examples. The measurement methods of thickness, Tg and Mw are as follows. In addition, unless otherwise specified, the "parts" and "%" in the examples and comparative examples are based on weight.

(1)Thickness

The thickness below 10μm is measured using an interferometer film thickness meter (manufactured by Otsuka Electronics Co., Ltd., product name "MCPD-3000"). The thickness greater than 10μm is measured using a digital micrometer (manufactured by Anritsu Co., Ltd., product name "KC-351C").

(2) Glass transition temperature (Tg)

Calculate it as follows: Take about 5 mg of the sample (polymer), perform DSC measurement under the following conditions, and calculate the midpoint glass transition temperature based on the measurement results.

‧Measurement device: manufactured by TA Instruments, product name: Q-2000

‧Temperature process: change the temperature from 0℃→150℃→0℃→150℃

‧Ambient gas: N ₂ (50mL/min)

‧Measurement speed: 10℃/min

(3) Weight average molecular weight (Mw)

Measured by gel permeation chromatography (GPC), the value is calculated using standard polystyrene conversion.

‧Analysis device: Tosoh, HLC-8120GPC

‧Pipeline: Made by Tosoh, G7000HXL+GMHXL+GMHXL

‧Column size: 7.8mmφ×30cm each, total 90cm

‧Column temperature: 40℃

‧Flow rate: 0.8ml/min

‧Injection volume: 100μl

‧Solvent: Tetrahydrofuran

‧Detector: Differential refractometer (RI)

‧Standard sample: polystyrene

[Implementation Example 1]

(Production of polarizers)

As the thermoplastic resin substrate, a long strip of amorphous isophthalic acid copolymer polyethylene terephthalate film (thickness: 100μm) with a water absorption rate of 0.75% and a Tg of about 75°C was used. Corona treatment was applied to one side of the resin substrate.

13 parts by weight of potassium iodide was added to 100 parts by weight of a PVA resin prepared by mixing polyvinyl alcohol (polymerization degree 4200, saponification degree 99.2 mol%) and acetyl acetyl modified PVA (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "GOHSEFIME Z410") at a ratio of 9:1, and the mixture was dissolved in water to prepare a PVA aqueous solution (coating liquid).

The above-mentioned PVA aqueous solution was applied to the corona-treated surface of the resin substrate and dried at 60°C to form a PVA-based resin layer with a thickness of 13μm to produce a laminate.

The obtained laminate was subjected to free-end uniaxial stretching to 2.4 times in the longitudinal direction (long side direction) between rollers of different circumferential speeds in an oven at 130°C (air-assisted stretching treatment).

Next, the laminate was immersed in an insolubilizing bath (boric acid aqueous solution obtained by mixing 4 parts by weight of boric acid with 100 parts by weight of water) at a liquid temperature of 40°C for 30 seconds (insolubilizing treatment).

Then, the concentration was adjusted in a dyeing bath (an iodine aqueous solution obtained by mixing iodine and potassium iodide at a weight ratio of 1:7 relative to 100 parts by weight of water) at a liquid temperature of 30°C and immersed for 60 seconds so that the single unit transmittance (Ts) of the final polarizer became 43.0% or more (dyeing treatment).

Next, immerse in a crosslinking bath (boric acid aqueous solution obtained by mixing 3 parts by weight of potassium iodide and 5 parts by weight of boric acid with 100 parts by weight of water) at a liquid temperature of 40°C for 30 seconds (crosslinking treatment).

Afterwards, the laminate was immersed in a boric acid aqueous solution (boric acid concentration 4.0 wt%, potassium iodide concentration 5 wt%) at a liquid temperature of 70°C, and uniaxially stretched in the longitudinal direction (length direction) between rollers of different circumferential speeds, with a total stretching ratio of 5.5 times (underwater stretching treatment).

Thereafter, the laminate was immersed in a cleaning bath (an aqueous solution obtained by mixing 4 parts by weight of potassium iodide with 100 parts by weight of water) at a liquid temperature of 20°C (cleaning treatment).

After that, it was dried in an oven maintained at 90°C and contacted with a SUS heating roller maintained at 75°C for about 2 seconds (drying and shrinking treatment). The shrinkage rate in the width direction of the laminate after the drying and shrinking treatment was 5.2%.

According to the above method, a polarizer with a thickness of 5μm is formed on the resin substrate.

(Production of polarizing plates)

On the surface of the polarizer obtained above (the surface opposite to the resin substrate), an HC-COP film is bonded as a protective layer through a UV-curable adhesive. Specifically, the UV-curable adhesive is applied so that the thickness after curing becomes 1.0 μm, and a roller press is used to bond. Thereafter, UV light is irradiated from the HC-COP film side to cure the adhesive. In addition, the HC-COP film is a film having a hard coating (HC) layer (thickness 2 μm) formed on a cycloolefin (COP) film (manufactured by Zeon Corporation, trade name "ZF12", thickness 25 μm), which is bonded to the COP film on the polarizer side. Next, the resin substrate is peeled off from the polarizer to obtain a polarizing plate having a structure of a protective layer (HC-COP film)/adhesive layer/polarizer.

(Formation of resin layer)

99.0 parts by weight of methyl methacrylate (MMA, manufactured by FUJIFILM Wako Pure Chemical Corporation, trade name: methyl methacrylate monomer), 1.0 parts by weight of the monomer of the general formula (1e), and 0.2 parts by weight of a polymerization initiator (manufactured by FUJIFILM Wako Pure Chemical Corporation, trade name: 2,2'-azobis(isobutyronitrile)) were dissolved in 100 parts by weight of toluene. Then, the mixture was heated to 70°C in a nitrogen environment and polymerized for 5.5 hours to obtain copolymer 1 (solid content concentration: 50% by weight). The Tg of copolymer 1 was 105°C and the Mw was 85,000.

To 70 parts (in terms of solid content) of the obtained copolymer 1 (boron-containing acrylic resin), 22.5 parts (in terms of solid content) of a trihydroxymethylpropane adduct of toluene diisocyanate (manufactured by Tosoh Corporation, trade name "CORONATE L") and 7.5 parts (in terms of solid content) of a trihydroxymethylpropane adduct of hexamethylene diisocyanate (manufactured by Mitsui Chemicals, trade name "TAKENATE D160N") were added as isocyanate compounds to obtain a mixture. The mixture was dissolved in 80 parts of a mixed solvent of ethyl acetate/cyclopentanone (70/30) to obtain a resin solution (20%). The resin solution was applied to the surface of the polarizer side of the polarizing plate obtained above using a wire rod, and the applied film was dried at 60°C for 5 minutes to form a resin layer (thickness 0.4μm) in the form of a cured product of the applied film of the resin organic solvent solution.

(Then the preparation of the drug composition)

The monomer components were mixed at the blending ratio shown in Table 1 to obtain an adhesive composition containing 3% by weight of a polymerization initiator (manufactured by BASF, trade name "Irgacure 907"). In addition, the monomers shown in Table 1 are equivalent to the above-mentioned trade names.

(Production of phase difference layer)

10 g of polymerizable liquid crystal (manufactured by BASF, trade name "Paliocolor LC242", represented by the following formula) showing a nematic liquid crystal phase and 3 g of a photopolymerization initiator for the polymerizable liquid crystal compound (manufactured by BASF, trade name "Irgacure907") were dissolved in 40 g of toluene to prepare a liquid crystal composition (coating liquid).

The surface of the polyethylene terephthalate (PET) film (thickness 38μm) is rubbed with a rubbing cloth to perform an orientation treatment. The direction of the orientation treatment is: when attached to the polarizing plate, it is viewed from the viewing side, and is 15° relative to the direction of the absorption axis of the polarizer. The above-mentioned liquid crystal coating liquid is applied to the orientation-treated surface using a rod coater, and heated and dried at 90°C for 2 minutes to orient the liquid crystal compound. Using a metal halide lamp, the liquid crystal layer formed in the above manner is irradiated with 1mJ/ ^cm2 of light to harden the liquid crystal layer, thereby forming a liquid crystal orientation solidified layer A (H layer) on the PET film. The thickness of the liquid crystal orientation solidified layer A is 2.5μm, and the in-plane phase difference Re(550) is 270nm. In addition, the liquid crystal orientation solidified layer A exhibits a refractive index characteristic of nx>ny=nz.

The coating thickness is changed, and the orientation treatment direction is made 75° relative to the absorption axis of the polarizer when viewed from the viewing side. The same operation as above is performed to form a liquid crystal orientation solidification layer B (Q layer) on the PET film. The thickness of the liquid crystal orientation solidification layer B is 1.5μm, and the in-plane phase difference Re (550) is 140nm. In addition, the liquid crystal orientation solidification layer B shows a refractive index characteristic of nx>ny=nz.

(Production of laminated bodies)

The above-mentioned adhesive composition is used to transfer the liquid crystal oriented solidified layer A to the resin layer surface of the polarizing plate formed with a resin layer in such a manner that the thickness of the adhesive layer formed after curing becomes 1.5 μm. At this time, the transfer (bonding) is performed so that the angle formed by the absorption axis of the polarizer and the slow axis of the liquid crystal oriented solidified layer A is 15°. In addition, the curing of the adhesive composition is performed by irradiating ultraviolet rays in a nitrogen environment in such a manner that the accumulated light amount becomes 900 mJ/ ^cm2 .

Next, use a UV-curable adhesive (1μm thickness after curing) to transfer the liquid crystal oriented solidified layer B to the surface of the liquid crystal oriented solidified layer A. At this time, the angle between the absorption axis of the polarizer and the slow axis of the liquid crystal oriented solidified layer B is 75° and the transfer (bonding) is performed. In addition, the curing of the adhesive composition is carried out by irradiating ultraviolet rays.

In addition, each transfer is performed while the rollers are transporting.

[Example 2 and Example 4]

Except for changing the monomer components contained in the adhesive composition as shown in Table 1 below, the same operation as Example 1 is performed to obtain a laminate.

[Implementation Example 3]

The laminate was obtained by operating in the same manner as in Example 2 except that poly(methyl methacrylate) (manufactured by Merck) having a Tg of 110°C and a Mw of 350,000 was used instead of copolymer 1 when forming the resin layer.

[Implementation Example 5]

The laminate was obtained by operating in the same manner as in Example 4 except that the isocyanate compound was changed as shown in Table 1 when forming the resin layer.

[Comparative Example 1, Comparative Example 2 and Comparative Example 3]

Except for changing the monomer components contained in the adhesive composition as shown in Table 1 below, the same operation as in Example 1 was performed to obtain a laminate.

[Comparison Example 4]

The same operation as in Example 4 was performed, except that poly(methyl methacrylate) (manufactured by Merck) with a Tg of 115°C and a Mw of 1,000,000 was used instead of copolymer 1 when forming the resin layer, to obtain a laminate.

[Comparison Example 5]

The laminate was obtained by operating in the same manner as in Example 4 except that no isocyanate compound was used when forming the resin layer.

The following evaluations were performed on the embodiments and comparative examples. The evaluation results are summarized in Table 1 together with various values.

<Evaluation>

1. Cross-section observation

The cross section of the obtained laminate was observed using a scanning electron microscope (magnification: 30,000 times) to confirm whether a compatible layer between the resin layer and the adhesive layer was formed.

[Evaluation Criteria]

Good: There is a clear interface between the resin layer and the adhesive layer, and no miscible layer is confirmed

Bad: There is no clear interface between the resin layer and the adhesive layer, and a compatible layer is confirmed.

2. Separation

After cutting out a sample of 200 mm in the length direction (extending direction of the polarizer) and 15 mm in the width direction from the obtained laminate with an adhesive and pasting it on a glass plate, a cutter was used to cut near the resin layer and the adhesive layer, and the polarizer was peeled off in the length direction at a peeling speed of 1000 mm/min at 90 degrees using a Tensilon universal testing machine RTC (manufactured by A&D Company, Limited), and the peeling force (N/15mm) at this time was measured. Specifically, the peeling force (adhesion force) of the adhesive layer (laminated portion of the adhesive layer and the phase difference layer) on the resin layer was measured. In addition, the measurement was performed in an environment of 23°C and 50%RH.

[Table 1]

Excellent adhesion was confirmed in each embodiment. As shown in FIG3, the compatible layer between the resin layer and the adhesive layer was not confirmed in each embodiment. In FIG3, the interface between the resin layer with a thickness of 0.4 μm and the adhesive layer with a thickness of 1.5 μm can be confirmed. On the other hand, in Comparative Examples 1, 2, and 3, the compatible layer was confirmed as shown in FIG4. In FIG4, there was no clear interface between the polarizer (upper side) and the phase difference layer (lower side), and a compatible layer with a thickness of 1.9 μm was confirmed.

Industrial availability

The multilayer body of the embodiment of the present invention can be used, for example, in an image display device. Representative examples of image display devices include liquid crystal display devices, organic EL display devices, and inorganic EL display devices.

10: Polarizing plate

11: Polarizer

11a: First main surface

11b: Second main surface

12: Protective layer

20: Resin layer

30: Next is the agent layer

40: Functional layer

100: Layered body

Claims (9)

A laminated body comprises: a polarizing plate including a polarizer, a functional layer, a resin layer and an adhesive layer disposed between the polarizing plate and the functional layer; The resin layer and the adhesive layer are disposed adjacent to each other; The resin layer comprises: a resin having a glass transition temperature of 85°C or higher and a weight average molecular weight Mw of 50,000 or higher and less than 500,000, and an isocyanate compound; the isocyanate compound comprises at least one selected from toluene diisocyanate, diphenylmethane diisocyanate, stubyl diisocyanate and their derivatives; the content of the resin in the resin layer is 50% by weight or higher and 90% by weight or lower, and the content of the isocyanate compound in the resin layer is 10% by weight or higher and 50% by weight or lower; The aforementioned adhesive layer is composed of a cured layer of an adhesive composition, and the octanol/water partition coefficient logPow calculated by weighted average of the molar fractions of the monomer components contained in the aforementioned adhesive composition is greater than 1.5 and less than 4.0. The laminate of claim 1, wherein the content of the monomer component having an octanol/water partition coefficient logPow of 0.0 or less is 30 parts by weight or less relative to 100 parts by weight of the monomer component contained in the adhesive composition. The laminate of claim 1, wherein the resin layer further comprises at least one of hexamethylene diisocyanate or its derivatives as the isocyanate compound. The laminate of claim 1, wherein the thickness of the adhesive layer is less than 3 μm. The laminate of claim 1, wherein the thickness of the resin layer is less than 1 μm. The laminate of claim 1, wherein the resin layer and the polarizer are disposed adjacent to each other. The multilayer structure of claim 1, wherein the functional layer is a phase difference layer. An image display device comprises a layered volume as described in any one of claims 1 to 7. A method for manufacturing a laminate, comprising the following steps: Coating an organic solvent solution containing a resin and an isocyanate compound on a polarizing plate or a functional layer containing a polarizer to form a resin layer; and Bonding the functional layer or the polarizing plate to the resin layer through an adhesive composition; The glass transition temperature of the resin is above 85°C and the weight average molecular weight Mw is above 50,000 and less than 500,000; The isocyanate compound comprises at least one selected from toluene diisocyanate, diphenylmethane diisocyanate, stubyl diisocyanate and their derivatives; The content of the aforementioned resin in the aforementioned resin layer is 50% by weight or more and 90% by weight or less, and the content of the aforementioned isocyanate compound in the aforementioned resin layer is 10% by weight or more and 50% by weight or less; The octanol/water partition coefficient logPow calculated by the weighted average of the molar fractions of the monomer components contained in the aforementioned adhesive composition is 1.5 or more and 4.0 or less.