CN115917383A - Polarizing plate with adhesive layer - Google Patents

Abstract

The invention provides a polarizing plate with an adhesive layer, which inhibits deiodination even under a high-temperature and high-humidity environment and is easy to eliminate generated curling. The present invention provides a polarizing plate with an adhesive layer, which comprises: a polarizing plate, a protective film disposed on one side of the polarizing plate via an adhesive layer, and a first adhesive layer disposed on the other side of the polarizing plate, wherein the polarizing plate is a film obtained by adsorbing iodine to a hydrophilic polymer film, and the first adhesive layer has a moisture permeability of 180 g/(m.H.) under conditions of a temperature of 40 ℃ and a relative humidity of 90% ² Day) or more and 1500 g/(m) ² Day) below.

Description

Polarizing plate with adhesive layer

technical field

The present invention relates to a polarizing plate with an adhesive layer, and an image display device including the polarizing plate with an adhesive layer.

Background technique

Patent Document 1 proposes a polarizing plate with an adhesive layer in which a polarizer protective film is laminated on one side of a polarizer via an adhesive layer, and an adhesive layer is laminated on the other side.

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2012-247574

Contents of the invention

The problem to be solved by the invention

An object of the present invention is to provide a polarizing plate with an adhesive layer that suppresses deiodination even in a high-temperature, high-humidity environment and that can easily eliminate curl.

means of solving problems

The present invention provides the following polarizing plate with an adhesive layer and an image display device.

[1] A polarizing plate with an adhesive layer comprising:

Polarizer,

A protective film arranged on one side of the polarizer through an adhesive layer, and

The first adhesive layer disposed on the other side of the polarizer,

The above-mentioned polarizer is a film obtained by absorbing iodine on a hydrophilic polymer film,

The moisture permeability of the first pressure-sensitive adhesive layer under conditions of a temperature of 40° C. and a relative humidity of 90% RH is not less than 180 g/(m ² ·day) and not more than 1500 g/(m ² ·day).

[2] The polarizing plate with an adhesive layer according to [1], wherein

The first pressure-sensitive adhesive layer is a layer containing a pressure-sensitive adhesive containing a (meth)acrylic resin.

[3] The polarizing plate with an adhesive layer according to [1] or [2], wherein

The thickness of the first pressure-sensitive adhesive layer is 10 μm or more.

[4] The polarizing plate with an adhesive layer according to any one of [1] to [3], wherein

The said protective film is a film containing a cyclic polyolefin resin.

[5] A laminate for a flexible image display device comprising:

The polarizing plate with an adhesive layer according to any one of [1] to [4], and

Front panel or touch sensor.

[6] An image display device comprising the polarizing plate with an adhesive layer according to any one of [1] to [4].

[7] A polarizing plate with an adhesive layer comprising:

polarizer, and

A protective film disposed on one side of the polarizer via an adhesive layer,

On the other side of the polarizer, a second adhesive layer, a functional layer, and a first adhesive layer are provided in order from the polarizer side,

The above-mentioned functional layer is a single layer of a liquid crystal solidified layer, or a multilayer of two or more layers selected from a liquid crystal solidified layer, an alignment layer and a bonding layer,

The above-mentioned polarizer is a film obtained by absorbing iodine on a hydrophilic polymer film,

A laminate formed of the second pressure-sensitive adhesive layer, the functional layer, and the first pressure-sensitive adhesive layer has a moisture permeability of 180 g/(m ² ·day) or more under conditions of a temperature of 40°C and a relative humidity of 90%RH And less than 1500g/(m ² ·day).

[8] The polarizing plate with an adhesive layer according to [7], wherein

The said protective film is a film containing a cyclic polyolefin resin.

[9] The polarizing plate with an adhesive layer according to [7] or [8], wherein

The above-mentioned functional layer includes a first liquid crystal solidified layer and a second liquid crystal solidified layer.

[10] A laminate for a flexible image display device comprising:

The polarizing plate with an adhesive layer according to any one of [7] to [9], and

Front panel or touch sensor.

[11] An image display device comprising the polarizing plate with an adhesive layer according to any one of [7] to [9].

Invention effect

According to the present invention, it is possible to provide a polarizing plate with an adhesive layer in which deiodination is suppressed even in a high-temperature, high-humidity environment and curling is easily eliminated.

Description of drawings

FIG. 1 is a schematic cross-sectional view showing an example of a polarizing plate with an adhesive layer of the present invention.

Fig. 2 is a schematic cross-sectional view showing another example of the polarizing plate with an adhesive layer of the present invention.

Fig. 3 is a schematic diagram showing a method of setting up a sample for deiodination evaluation.

4 is a diagram showing an observation image under an optical microscope of the polarizing plate with an adhesive layer obtained in Example 1. FIG.

5 is a diagram showing an example of data converted into monochrome 256 gradation data of the observed image of the polarizing plate with an adhesive layer obtained in Example 1. FIG.

Fig. 6 is a schematic diagram illustrating a method of measuring the curl height.

Detailed ways

Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments. In all of the following drawings, the scales are appropriately adjusted to make each component easier to understand. The scale of each component shown in the drawings does not necessarily match the scale of the actual component.

＜Polarizing plate with adhesive layer＞

[first embodiment]

The polarizing plate with an adhesive layer (hereinafter also referred to as the first polarizing plate) according to the first embodiment of the present invention includes: a polarizing plate, a protective film disposed on one side of the polarizing plate via an adhesive layer, and a The first adhesive layer on the other side of the polarizer. An example of the layer configuration of the first polarizing plate is shown in FIG. 1 . The first polarizing plate 100 shown in FIG. 1 includes a protective film 11 , an adhesive layer 12 , a polarizing plate 10 , and a first adhesive layer 13 in this order.

The first polarizing plate 100 is preferably composed of only the protective film 11 , the adhesive layer 12 , the polarizing plate 10 , and the first adhesive layer 13 . The first polarizing plate 100 preferably has the protective film 11 laminated on one side of the polarizing plate 10 via only the adhesive layer 12 . In the first polarizing plate 100 , the first adhesive layer 13 is preferably directly laminated on the surface of the polarizing plate 10 opposite to the adhesive layer 12 side. In the case where the first polarizing plate 100 is only composed of the protective film 11, the adhesive layer 12, the polarizer 10, and the first adhesive layer 13, the first polarizing plate 100 can be used as a linear polarizer with an adhesive layer. board use.

The thickness of the first polarizing plate 100 varies depending on the function required of the first polarizing plate 100 and the use of the first polarizing plate 100, so it is not particularly limited. For example, it may be 5 μm or more, or it may be 10 μm or more, for example, it may be 200 μm. Below, it may be 150 μm or less, 120 μm or less, 100 μm or less, 80 μm or less, or 70 μm or less.

[Polarizer]

The polarizing plate 10 has properties of absorbing linearly polarized light having a vibration plane parallel to its absorption axis and transmitting linearly polarized light having a vibration plane perpendicular to the absorption axis (parallel to the transmission axis). The polarizer 10 is a film obtained by adsorbing iodine to a hydrophilic polymer film. The polarizing plate 10 can be produced, for example, through the following steps: a step of uniaxially stretching the hydrophilic polymer film; a step of dyeing the hydrophilic polymer film with iodine to allow iodine to absorb; A step of treating a hydrophilic polymer film having iodine adsorbed thereon; and a step of washing with water after the treatment with an aqueous solution of boric acid.

As a hydrophilic polymer film, a polyvinyl-alcohol-type resin film etc. are mentioned, for example. The polyvinyl alcohol-based resin is obtained by saponifying polyvinyl acetate-based resin. As the polyvinyl acetate-based resin, in addition to polyvinyl acetate which is a homopolymer of vinyl acetate, a copolymer of vinyl acetate and other monomers that can be copolymerized with vinyl acetate can also be used. Examples of other monomers that can be copolymerized with vinyl acetate include unsaturated carboxylic acid-based compounds, olefin-based compounds, vinyl ether-based compounds, unsaturated sulfone-based compounds, and (meth)acrylic compounds having ammonium groups. Amide compounds. In the present specification, "(meth)acrylic acid" means at least one selected from acrylic acid and methacrylic acid. The same applies to "(meth)acrylate" and the like.

The degree of saponification of the polyvinyl alcohol-based resin is generally not less than 85 mol % and not more than 100 mol %, preferably not less than 98 mol %. The polyvinyl alcohol-based resin may be modified, and polyvinyl formal or polyvinyl acetal modified with aldehydes may be used. The degree of polymerization of the polyvinyl alcohol-based resin is usually not less than 1,000 and not more than 10,000, preferably not less than 1,500 and not more than 5,000.

The polarizing plate 10 has iodine adsorbed and oriented, and the boron content is 5.5% by mass or less, preferably 5.0% by mass or less, more preferably 4.5% by mass or less, so that shrinkage due to heating can be suppressed. The content of boron is preferably 0.5% by mass or more, more preferably 1% by mass or more, and may be 2% by mass or more. By making the content of boron 0.5% by mass or more, it can be expected that iodine can be held stably and discoloration can be suppressed.

The thickness of the polarizing plate 10 is usually 30 μm or less, preferably 15 μm or less, more preferably 13 μm or less, still more preferably 10 μm or less, particularly preferably 8 μm or less. The thickness of the polarizing plate 10 is usually 2 μm or more, preferably 3 μm or more, for example, 5 μm or more.

[protective film]

The protective film 11 is disposed on one side of the polarizer 10 and can have a function of protecting the polarizer 10 . The protective film 11 can be set as a coating layer or a film comprising an optically transparent thermoplastic resin such as a cyclic polyolefin resin; acetic acid containing resins such as cellulose triacetate and cellulose diacetate; Cellulose-based resins; polyester-based resins including resins such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate; polycarbonate-based resins; (methyl ) acrylic resin; polypropylene resin, one or a mixture of two or more of these resins.

A hard coat layer may be formed on the protective film 11 . The hard coat layer may be formed on one side or both sides of the protective film 11 . By providing a hard coat layer, it is possible to obtain the protective film 11 with improved hardness and scratch resistance. The hard coat layer may be, for example, a cured layer of acrylic resin, silicone resin, polyester resin, polyurethane resin, amide resin, epoxy resin, or the like. In order to increase the strength, the hard coat may contain additives.

The additives are not limited, and examples thereof include inorganic fine particles, organic fine particles, or mixtures thereof. The hard coat layer is, for example, a cured layer of an ultraviolet curable resin. Examples of ultraviolet curable resins include acrylic resins, silicone resins, polyester resins, polyurethane resins, amide resins, and epoxy resins.

The thickness of the protective film 11 is usually not less than 1 μm and not more than 100 μm, preferably not less than 5 μm and not more than 80 μm, more preferably not less than 8 μm and not more than 60 μm, and still more preferably not less than 12 μm and not more than 45 μm, from the viewpoint of strength and handleability. 30 μm or less.

[adhesive layer]

The adhesive bond layer 12 may exist between the protective film 11 and the polarizing plate 10, and may bond both. As the adhesive for forming the adhesive layer 12, water-based adhesives, active energy ray-curable adhesives, or thermosetting adhesives are mentioned, and water-based adhesives, active energy ray-curable adhesives are preferably used. Adhesive. The surfaces of the opposing protective film 11 and polarizing plate 10 bonded via the adhesive layer 12 may be subjected to corona treatment, plasma treatment, flame treatment, etc. in advance, and may have an undercoat layer or the like.

From the viewpoint of ensuring adhesiveness, the thickness of the adhesive layer 12 is not less than 0.01 μm and not more than 10 μm.

[First Adhesive Layer]

In the first embodiment, the moisture permeability of the first adhesive layer 13 under the conditions of a temperature of 40° C. and a relative humidity of 90% RH (hereinafter, also simply referred to as “moisture permeability”) is 180 g/(m ² ·day). Not less than 1500 g/(m ² ·day). The moisture permeability was measured in accordance with the measuring method described in the section of Examples described later.

抜け)的倾向。尤其是，对于在偏振片的一侧仅经由粘接剂层配置有保护膜、并且在另一侧直接配置有粘合剂层的带粘合剂层的偏振板而言，存在容易发生脱碘的倾向。通过使第一偏振板100的第一粘合剂层13的透湿度为1500g/(m²·day)以下，从而存在容易抑制脱碘的倾向。需要说明的是，在分别在偏振片的两面经由粘接剂层而层叠有保护膜的情况(两面保护型偏振板)下，存在不易发生这样的脱碘的倾向。The polarizing plate with an adhesive layer is bonded to an organic EL display element or a liquid crystal cell (usually an inorganic glass surface) via the adhesive layer. In the case where the polarizer is a hydrophilic resin film, it tends to have poor heat and humidity resistance after being bonded to the inorganic glass surface, and so-called deiodination (Japanese: ヨウ

抜け) tendency. In particular, for a polarizing plate with an adhesive layer in which a protective film is disposed only via an adhesive layer on one side of the polarizer, and an adhesive layer is directly disposed on the other side, deiodination easily occurs. Propensity. When the water vapor transmission rate of the first pressure-sensitive adhesive layer 13 of the first polarizing plate 100 is 1500 g/(m ² ·day) or less, it tends to be easy to suppress deiodination. In addition, in the case where a protective film is laminated|stacked on both surfaces of a polarizing plate via an adhesive layer respectively (both-surface protection type polarizing plate), there exists a tendency for such deiodination to not generate|occur|produce easily.

In addition, the protective film included in the polarizing plate with an adhesive layer is usually stiffer than the adhesive layer. Therefore, in the case where a polarizing plate with an adhesive layer is manufactured by attaching a protective film to one side of the polarizer only via an adhesive layer, and directly laminating an adhesive layer on the other side, the thus manufactured tape A polarizing plate with an adhesive layer tends to be more prone to curling than a polarizing plate having a protective film on both surfaces. Curls can be eliminated by storage in an atmosphere different from that of the bonding step, for example, at room temperature and high humidity, and it is desirable that the time required for the elimination of curls is short. When the water vapor transmission rate of the first adhesive layer 13 of the first polarizing plate 100 is 180 g/(m ² ·day) or more, curling tends to be easily eliminated in a relatively short time.

From the viewpoint of the suppression of deiodination and the shortening of the decurling time, the water vapor transmission rate of the first adhesive layer 13 is preferably 300 g/(m ² ·day) or more and 1400 g/(m ² ·day) or less, more preferably 500 g/(m ² ·day) to 1300 g/(m ² ·day), more preferably 700 g/(m ² ·day) to 1200 g/(m ² ·day).

The moisture permeability of the first pressure-sensitive adhesive layer 13 can be adjusted by, for example, selection of types and ratios of components of the pressure-sensitive adhesive composition, crosslinking density, and the like. In addition, it can also be adjusted by laminating a plurality of adhesives with different moisture permeability. The crosslink density can be adjusted by changing the production conditions and by appropriately selecting the type and amount of the crosslinking agent. As a method of adjusting the moisture permeability by lamination of the adhesive, for example, it can be adjusted by appropriately determining the ratio of the thicknesses of the low moisture permeability adhesive layer and the high moisture permeability adhesive. Examples of low moisture-permeable adhesives used for lamination include adhesives mainly composed of rubber-based resins. Among acrylic adhesives used for optical applications, those with high moisture-permeable Lots of adhesive.

The first adhesive layer 13 can be made of an adhesive composition mainly composed of resins such as (meth)acrylic, rubber, urethane, ester, silicone, and polyvinyl ether. Formed in one or more layers. Among them, an adhesive composition comprising, as a base polymer, a (meth)acrylic resin excellent in transparency, weather resistance, heat resistance, etc. is suitable and preferably contained. The adhesive composition is preferably an active energy ray-curable type or a heat-curable type.

As the (meth)acrylic resin (base polymer) used in the adhesive composition, for example, butyl (meth)acrylate, ethyl (meth)acrylate, (meth)acrylic acid A polymer or a copolymer of one or more of (meth)acrylates such as isooctyl and 2-ethylhexyl (meth)acrylate as monomers. It is preferred to copolymerize polar monomers with the base polymer. Examples of polar monomers include (meth)acrylic acid, 2-hydroxypropyl (meth)acrylate, hydroxyethyl (meth)acrylate, (meth)acrylamide, (meth)acrylic acid N , N-dimethylaminoethyl ester, glycidyl (meth)acrylate and other monomers having carboxyl groups, hydroxyl groups, amido groups, amino groups, epoxy groups, etc.

The adhesive composition may contain only the above-mentioned base polymer, but usually also contains a crosslinking agent. Examples of the crosslinking agent include: a metal ion having a divalent or higher valence, which forms a metal carboxylate salt with a carboxyl group; a polyamine compound, which forms an amide bond with a carboxyl group; As a cross-linking agent for forming an ester bond with carboxyl groups of polyepoxides and polyols; as a cross-linking agent for forming amide bonds with carboxyl groups for polyisocyanate compounds. Among them, polyisocyanate compounds are preferable.

The adhesive composition can contain one or more additives such as antistatic agents, solvents, crosslinking catalysts, tackifiers, plasticizers, softeners, pigments, rust inhibitors, inorganic fillers, organic fillers, etc. as other Element.

The thickness of the first adhesive layer 13 may be, for example, 3 μm or more, preferably 5 μm or more, and more preferably 10 μm or more. The thickness of the first adhesive layer 13 may be, for example, 50 μm or less, preferably 40 μm or less, more preferably 30 μm or less, and further preferably 27 μm or less from the viewpoint of thinning.

[other layers]

The first polarizing plate 100 may include a protective film (Japanese: Protect film) for protecting the surface (the surface of the protective film 11, etc.), a separation film (hereinafter, also referred to as a spacer) laminated on the outer surface of the first adhesive layer 13 pieces) as other layers.

[protective film]

After bonding a polarizing plate to an image display element or other optical members, for example, this protective film is peeled off together with the pressure-sensitive adhesive layer it has.

The pellicle film is formed of, for example, a base film and an adhesive layer laminated thereon. Regarding the adhesive layer, the above description is cited.

The resin forming the base film may be, for example, polyethylene-based resins such as polyethylene, polypropylene-based resins such as polypropylene, polyester-based resins such as polyethylene terephthalate, and polyethylene naphthalate. Thermoplastic resins such as resins and polycarbonate resins. Polyester-based resins such as polyethylene terephthalate are preferred.

[Separation Membrane]

The separation membrane may be a film made of polyethylene-based resins such as polyethylene, polypropylene-based resins such as polypropylene, polyester-based resins such as polyethylene terephthalate, or the like. Among them, a stretched film of polyethylene terephthalate is preferable. The surface of the separation membrane may be subjected to a peeling treatment.

[Second Embodiment]

A polarizing plate with an adhesive layer (hereinafter also referred to as a second polarizing plate) according to the second embodiment of the present invention includes: a polarizing plate and a protective film disposed on one side of the polarizing plate through an adhesive layer, and The other side of the polarizing plate includes a second pressure-sensitive adhesive layer, a functional layer, and a first pressure-sensitive adhesive layer in this order from the polarizing plate side. An example of the layer configuration of the second polarizing plate is shown in FIG. 2 . Fig. 2 is a schematic cross-sectional view of an example of a second polarizing plate. The second polarizing plate 200 shown in FIG. 2 includes a protective film 11 , an adhesive layer 12 , a polarizing plate 10 , a second adhesive layer 14 , a functional layer 15 , and a first adhesive layer 13 in this order.

The second polarizing plate 200 is preferably composed of only the protective film 11 , the adhesive layer 12 , the polarizer 10 , the second adhesive layer 14 , the functional layer 15 , and the first adhesive layer 13 . The second polarizing plate 200 preferably has the protective film 11 laminated only on one side of the polarizing plate 10 via the adhesive layer 12 . In the second polarizing plate 200 , it is preferable that the second adhesive layer 14 is directly laminated on the surface of the polarizing plate 10 opposite to the adhesive layer 12 side.

The protective film 11, the adhesive layer 12 and the polarizer 10 in the second polarizing plate 200 are respectively applicable to the protective film 11, the adhesive layer 12, the first adhesive layer 13 and the polarizer in the first polarizing plate 100 described above. Description of sheet 10. In addition, the second polarizing plate 200 may include other layers such as a protective film and a separation film described in the above-mentioned first polarizing plate 100 .

[First adhesive layer and second adhesive layer]

The first adhesive layer 13 may have a function of attaching the second polarizing plate 200 to the image display device. The second adhesive layer 14 may exist between the polarizing plate 10 and the functional layer 15 to join them. The first adhesive layer 13 and the second adhesive layer 14 can be made of resins such as (meth)acrylic, rubber, urethane, ester, silicone, and polyvinyl ether. The main component of the adhesive composition is formed. The adhesive composition forming the first adhesive layer 13 (hereinafter also referred to as "first adhesive composition") and the adhesive composition forming the second adhesive layer 14 (hereinafter also referred to as The "second adhesive composition") may be of the same type or of different types. As the first and second pressure-sensitive adhesive compositions, a pressure-sensitive adhesive composition using a (meth)acrylic resin excellent in transparency, weather resistance, heat resistance, etc. as a base polymer is preferable. The first and second adhesive compositions may be active energy ray-curable or heat-curable.

The description of the (meth)acrylic resin (base polymer), crosslinking agent, and other components used in the first and second adhesive compositions in the second polarizing plate 200 applies to the above-mentioned first polarizing Description of the (meth)acrylic resin (base polymer), crosslinking agent, and other components described in the sheet 100.

The moisture permeability of the first adhesive layer 13 may be, for example, 10 g/(m ² ·day) or more, preferably 20 g/(m ² ·day) or more and 6000 g/(m ² ·day) or less, more preferably 100 g/(m 2 ·day). (m ² ·day) to 3000 g/(m ² ·day), more preferably 180 g/(m ² ·day) to 1500 g/(m ^{2 ·} day).

The thickness of the first adhesive layer 13 may be, for example, 3 μm or more, preferably 5 μm or more, and more preferably 10 μm or more. For example, it may be 50 μm or less, preferably 40 μm or less, more preferably 30 μm or less, and further preferably 27 μm or less from the viewpoint of thinning.

The thickness of the second adhesive layer 14 may be, for example, 2 μm to 30 μm, preferably 3 μm to 20 μm. For example, it may be 10 μm or more, but from the viewpoint of further thinning, it is preferably 15 μm or less, more preferably 10 μm or less, and particularly preferably 7 μm or less.

[Functional layer]

The functional layer 15 is a single layer of a liquid crystal solidified layer alone, or a multilayer of two or more layers selected from a liquid crystal solidified layer, an alignment layer, and a bonding layer. The functional layer 15 preferably includes two liquid crystal solidified layers, and more preferably has a layer structure in which two liquid crystal solidified layers are laminated via an adhesive layer.

[Liquid crystal solidified layer]

The liquid crystal solidified layer may be a retardation layer containing a cured product of a polymerizable liquid crystal compound that exhibits optical anisotropy by applying and aligning the polymerizable liquid crystal compound to a substrate. The retardation layer which is a hardened|cured material of a polymerizable liquid crystal compound includes the 1st form - 5th form.

First form: Retardation layer in which a rod-shaped liquid crystal compound is aligned in a horizontal direction with respect to a support substrate

Second form: Retardation layer in which the rod-shaped liquid crystal compound is aligned in the vertical direction with respect to the support substrate

The third form: a retardation layer in which a rod-shaped liquid crystal compound changes the alignment direction helically in the plane

The fourth form: a retardation layer with a discotic liquid crystal compound obliquely oriented

Fifth form: a biaxial retardation layer in which a discotic liquid crystal compound is oriented in a vertical direction with respect to a support substrate

For example, as an optical film used for an organic electroluminescent display, the first aspect, the second aspect, and the fifth aspect are preferably used. Alternatively, retardation layers of these forms may be used in a stacked manner.

When the retardation layer is a layer containing a polymer in an aligned state of a polymerizable liquid crystal compound (hereinafter, sometimes referred to as an "optical anisotropic layer"), the retardation layer preferably has reverse wavelength dispersion. Inverse wavelength dispersion refers to the optical characteristics that the in-plane retardation value of the liquid crystal alignment at a short wavelength is smaller than the in-plane retardation value of the liquid crystal alignment at a long wavelength, and the retardation film preferably satisfies the following formula (1) and formula (2) ). It should be noted that Re(λ) represents an in-plane retardation value with respect to light having a wavelength of nm.

Re(450)/Re(550)≤1(1)

1≤Re(630)/Re(550) (2)

In the case where the phase difference layer is in the first form and has reverse wavelength dispersibility, since the coloring at the time of black display in the display device is reduced, it is preferable that, in the above formula (1), if 0.82≤Re(450)/Re( 550)≤0.93, it is more preferred. More preferably, 120≦Re(550)≦150.

Examples of the polymerizable liquid crystal compound used to form the retardation layer include "3.8.6 Network (Completely Crosslinked Type)" in Liquid Crystal Handbook (edited by the Liquid Crystal Handbook Editorial Committee, published by Maruzen Co., Ltd. on October 30, 2012). ", "6.5.1 Liquid crystal material b. Polymerizable nematic liquid crystal material" among the compounds described in the compounds having a polymerizable group, and Japanese Patent Application Laid-Open No. 2010-31223, Japanese Patent Laid-Open No. 2010-270108, Japan JP 2011-6360, JP 2011-207765, JP 2011-162678, JP 2016-81035, International Publication 2017/043438 and JP 2011-207765 The polymerizable liquid crystal compound described in the gazette, etc.

As a method of producing a retardation layer from a polymer in an aligned state of a polymerizable liquid crystal compound, for example, the method described in JP 2010-31223 A may be mentioned.

The retardation layer, which is a liquid crystal solidified layer formed by curing a polymerizable liquid crystal compound, has a thickness of, for example, 0.1 μm to 10 μm, preferably 0.5 μm to 8 μm, more preferably 1 μm to 6 μm.

The retardation layer can be a λ/4 retardation layer that imparts a retardation of 1/4 wavelength to transmitted light, a λ/2 retardation layer that imparts a retardation of 1/2 wavelength to transmitted light, a positive type (Japanese:ポジテイブ) A plate, and positive C plate. The functional layer may contain two liquid crystal solidified layers. In the case where the functional layer includes a first liquid crystal solidified layer and a second liquid crystal solidified layer, the combination of the liquid crystal solidified layer may be a combination of a λ/2 retardation layer and a λ/4 retardation layer, a λ/4 retardation layer and a positive phase difference layer. Combination of type C layers, etc.

The second polarizing plate 200 may be configured as a circular polarizing plate having a λ/4 retardation layer. A circular polarizing plate can be used as a polarizing plate for antireflection.

[Orientation layer]

The alignment layer may be disposed between the aforementioned base material and the layer of the cured product of the polymerizable liquid crystal compound. The alignment layer has an alignment regulating force for aligning the liquid crystal in a desired direction in the liquid crystal solidified layer formed thereon. Examples of the alignment layer include an alignment polymer layer formed of an alignment polymer, a photo-alignment polymer layer formed of a photo-alignment polymer, a layer having a concave-convex pattern, and a plurality of grooves (grooves) on the surface of the layer. trench alignment film. The thickness of the alignment layer may be, for example, not less than 10 nm and not more than 500 nm, preferably not less than 10 nm and not more than 200 nm.

The alignment polymer layer can be formed by applying a composition obtained by dissolving an alignment polymer in a solvent on a base material, removing the solvent, and performing grinding treatment as necessary. In this case, in the alignment polymer layer formed of the alignment polymer, the alignment restricting force can be adjusted arbitrarily according to the surface state of the alignment polymer and polishing conditions.

The photo-alignment polymer layer can be formed by applying a composition containing a polymer or monomer having a photoreactive group and a solvent to a substrate layer and irradiating polarized light. In this case, in the photo-alignment polymer layer, the alignment-regulating force can be adjusted arbitrarily according to the polarized light irradiation conditions and the like to the photo-alignment polymer.

The groove alignment film can be formed by, for example, the method of forming a concavo-convex pattern through an exposure mask having pattern-shaped slits on the surface of the photosensitive polyimide film; A method in which an uncured layer of an active energy ray-curable resin is formed on a plate-shaped master, and the layer is transferred to a substrate and cured; by forming an uncured layer of an active energy ray-curable resin on a substrate layer, a method of pressing a roll-shaped master having unevenness on the layer, etc. to form unevenness and harden it.

[Adhesive layer]

The bonding layer may be provided to join the two layers. The bonding layer may be formed of an adhesive or an adhesive. In the case where the functional layer 15 includes two liquid crystal solidified layers, the two liquid crystal solidified layers can be joined by an adhesive layer.

A water-based adhesive, an active energy ray-curable adhesive, a thermosetting adhesive, or the like can be used for the adhesive layer. From the viewpoint of ensuring adhesiveness, the thickness of the adhesive layer is not less than 0.01 μm and not more than 10 μm.

The adhesive may be formed from the same adhesive composition as that used to form the first and second adhesive layers, or may be made of (meth)acrylic, rubber, or urethane-based adhesives. , ester-based, silicone-based, and polyvinyl ether-based resins as a main component of an adhesive composition (hereinafter, also referred to as "the third adhesive composition") is formed. As the third pressure-sensitive adhesive composition, a pressure-sensitive adhesive composition using a (meth)acrylic resin excellent in transparency, weather resistance, heat resistance, etc. as a base polymer is preferable. The third adhesive composition may be an active energy ray-curable type or a heat-curable type. The thickness of the pressure-sensitive adhesive layer is usually 0.1 μm to 150 μm, for example, 3 μm to 60 μm, preferably 30 μm or less, more preferably 20 μm or less from the viewpoint of thinning. The thickness of the adhesive layer may be, for example, 10 μm or more, and is preferably 15 μm or less, more preferably 10 μm or less, particularly preferably 7 μm or less, from the viewpoint of further thinning.

[moisture permeability]

For the second polarizing plate 200, the moisture permeability of the laminate formed by the second adhesive layer 14, the functional layer 15, and the first adhesive layer 13 is 180 g/(m ² ·day) or more and 1500 g/( m ² ·day) or less.

For a tape in which a protective film is laminated only via an adhesive layer on one side of a polarizer, and a second adhesive layer, a functional layer, and a first adhesive layer are laminated directly in this order from the polarizer side on the other side For the polarizing plate with an adhesive layer, it may also have a second adhesive layer and a functional layer. It should be noted that, since there is a tendency that the moisture and heat resistance after being bonded to the inorganic glass surface is poor, there is a tendency that iodine is easily generated. The so-called deiodination tends to detach at the end of the polarizing plate. For the second polarizing plate 100, the laminate formed by the second adhesive layer 14, the functional layer 15, and the first adhesive layer 13 (hereinafter, for simplification, also simply referred to as "laminate") When the moisture permeability is 1500 g/(m ² ·day) or less, deiodination tends to be easily suppressed.

In addition, although the second polarizing plate 200 has a functional layer, the thickness of the liquid crystal solidified layer and the bonding layer forming the functional layer is relatively thin. The protective film included in the second polarizing plate is rigid compared to the adhesive layer, so even when the second polarizing plate 200 has a functional layer, it is more likely to occur than a polarizing plate with protective films on both sides. Tendency to curl. For the second polarizing plate 200, by setting the moisture permeability of the laminate formed by the second adhesive layer 14, the functional layer 15, and the first adhesive layer 13 to be 180 g/(m ² ·day) or more, there is Easily eliminates the tendency to curl in a relatively short period of time.

From the viewpoint of the suppression of deiodination and the shortening of the curl elimination time, the moisture permeability of the laminate is preferably 220 g/(m ² ·day) or more and 800 g/(m ² ·day) or less, and more preferably 240 g/(m ^{2 ·} day). Day) to 700 g/(m ² ·day), more preferably 250 g/(m ² ·day) to 600 g/(m ^{2 ·} day).

The water vapor transmission rate of the laminate can be adjusted within the above range by adjusting the water vapor transmission rates of the first pressure-sensitive adhesive layer 13 and the second pressure-sensitive adhesive layer 14, for example.

[Manufacturing method of polarizing plate with adhesive layer]

The first polarizing plate 100 can be manufactured as follows, for example. First, the polarizing plate 10 and the protective film 11 are laminated via the adhesive layer 12 . The polarizing plate can be manufactured by preparing long members, bonding each member in a roll-to-roll manner, and cutting into a predetermined shape, or cutting each member into a predetermined shape and bonding them together. After bonding the protective film 1 to the polarizing plate 10, a heating step and a humidity conditioning step may be provided. Then, the first adhesive layer 13 formed on the release film is laminated on the polarizing plate 10 .

The second polarizing plate 200 can be manufactured as follows, for example. First, the polarizing plate 10 and the protective film 11 are laminated via the adhesive layer 12 . The polarizing plate can be manufactured by preparing long members, bonding each member in a roll-to-roll manner, and cutting into a predetermined shape, or cutting each member into a predetermined shape and bonding them together. After bonding the protective film 1 to the polarizing plate 10, a heating step and a humidity conditioning step may be provided.

When the functional layer 15 is a retardation layer, it can manufacture as follows, for example. An alignment film is formed on a substrate, and a coating liquid containing a polymerizable liquid crystal compound is coated on the alignment film. In the state where the polymerizable liquid crystal compound is aligned, active energy rays are irradiated to cure the polymerizable liquid crystal compound. On the layer formed by curing the polymerizable liquid crystal compound, the first pressure-sensitive adhesive layer 13 formed on the release film is laminated. Next, the substrate and/or the alignment film are peeled off. Next, the second adhesive layer 14 formed on the release film is laminated on the polarizing plate 10 . The retardation layer can be manufactured by preparing long members, bonding each member in a roll-to-roll manner, and then cutting into a predetermined shape, or cutting each member into a predetermined shape and bonding them together.

Then, the release film laminated on the second adhesive layer 14 is peeled off, and the functional layer 15 and the polarizing plate 10 are bonded via the second adhesive layer 14 , whereby the second polarizing plate 200 can be produced.

＜Image Display Device＞

The first polarizing plate 100 and the second polarizing plate 200 can be arranged on the front surface (visible side) of the image display panel and used as components of the image display device. The polarizing plate with an adhesive layer which is a circular polarizing plate can also be used as an antireflection polarizing plate for imparting an antireflection function in an image display device. The image display device is not particularly limited, and examples thereof include image display devices such as organic electroluminescence (organic EL) display devices, inorganic electroluminescence (inorganic EL) display devices, liquid crystal display devices, and electroluminescent display devices.

[Flexible image display device]

The image display device may be a flexible image display device. The flexible image display device includes a laminate for a flexible image display device described later and an organic EL display panel, and the laminate for a flexible image display device is arranged on the viewing side of the organic EL display panel, and is configured to be bendable.

<Laminates for flexible image display devices>

A laminate for a flexible image display device includes the polarizing plate with an adhesive layer of the present invention, and a front panel or a touch sensor. The lamination order of the polarizing plate with an adhesive layer of the present invention, the front panel, and the touch sensor may be, for example, the order of the front panel, the polarizing plate with an adhesive layer of the present invention, and the touch sensor from the visible side. The stacking order is preferably the order of the front panel, the touch sensor, and the polarizing plate with an adhesive layer of the present invention. If the polarizing plate is located closer to the visible side than the touch sensor, the pattern of the touch sensor will not be visually recognized, and the visibility of the displayed image will be improved, which is preferable. The respective members can be laminated using an adhesive, an adhesive, or the like. In addition, the laminate for a flexible image display device may include a light-shielding pattern formed on at least one surface of any layer of a front plate, a polarizing plate, and a touch sensor.

[front panel]

The front panel can be configured on the visible side of the polarizing plate. The front panel can be laminated on the polarizing plate via an adhesive layer. As an adhesive layer, the above-mentioned pressure-sensitive adhesive layer and adhesive layer are mentioned, for example.

As a front plate, the front plate etc. which contain a hard-coat layer on at least one side of glass or a resin film are mentioned. As the glass, for example, high transmission glass and tempered glass can be used. In particular, when using a thin transparent surface material, chemically strengthened glass is preferable. The thickness of glass can be set to 100 micrometers - 5 mm, for example.

A front panel comprising a hard coat layer on at least one side of a resin film can be flexible rather than hard and straight like conventional glass. The thickness of the hard coat layer is not particularly limited, and may be, for example, 5 to 100 μm.

The resin film may be a film formed of a cycloolefin-based derivative having a unit of a monomer containing a cycloolefin such as norbornene or a polycyclic norbornene-based monomer, a fiber (cellulose diacetate, cellulose triacetate, cellulose acetate butyrate, isobutyl cellulose, cellulose propionate, cellulose butyrate, cellulose acetate propionate) ethylene-vinyl acetate copolymer, polycyclic Olefin, polyester, polystyrene, polyamide, polyetherimide, polyacrylic acid, polyimide, polyamideimide, polyethersulfone, polysulfone, polyethylene, polypropylene, polymethylpentene , polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl acetal, polyether ketone, polyether ether ketone, polyether sulfone, polymethyl methacrylate, polyethylene terephthalate, Polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyurethane, epoxy resin and other polymers. As the resin film, unstretched, uniaxially or biaxially stretched films can be used. These polymers can be used alone or in combination of two or more. As the resin film, a polyamide-imide film or a polyimide film excellent in transparency and heat resistance, a uniaxially or biaxially stretched polyester film, excellent in transparency and heat resistance, and capable of handling the film Larger cycloolefin-based derivative films, polymethyl methacrylate films, and transparent cellulose triacetate and isobutyl cellulose films without optical anisotropy. The thickness of the resin film may be 5 to 200 μm, preferably 20 to 100 μm.

[shading pattern]

The light-shielding pattern (light-shielding plate) is formed on at least one surface of any one of the front plate, the polarizing plate, and the touch sensor constituting the laminate for a flexible image display device. For example, it may be formed on the display element side in the front panel. The light-shielding pattern can hide each wiring of the display device so as not to be visually recognized by the user. The color and material of the light-shielding pattern are not particularly limited, and may be formed of a resin material having various colors such as black, white, and gold. In one embodiment, the thickness of the light-shielding pattern may be in the range of 2 μm to 50 μm, preferably in the range of 4 μm to 30 μm, and more preferably in the range of 6 μm to 15 μm. In addition, the light-shielding pattern may be given a shape in order to suppress the entrainment of air bubbles and the visibility of the boundary portion due to the height difference between the light-shielding pattern and the display portion.

[touch sensor]

A touch sensor can be used as an input device. As the touch sensor, various types such as a resistive film type, a surface acoustic wave type, an infrared type, an electromagnetic induction type, and an electrostatic capacitance type have been proposed, and any type may be used. Among them, the capacitive method is preferable. The capacitive touch sensor is divided into an active area and an inactive area located on the outer edge of the active area. The active area is an area corresponding to a display screen on the display panel (display section) and is an area that senses a user's touch, and the inactive area is an area corresponding to an area of the display device that does not display a screen (non-display section). The touch sensor may include: a flexible substrate; a sensing pattern formed on an active region of the substrate; and an inactive region formed on the substrate for connecting to an external drive circuit via the sensing pattern and pad portion. Sensing lines (Japanese: Sensingrain). As the substrate having flexible properties, the same material as that of the transparent substrate of the front panel described above can be used. From the viewpoint of suppressing cracks that may occur in the touch sensor, the substrate of the touch sensor preferably has a toughness of 2000 MPa% or more. More preferably, the toughness is 2000MPa% to 30000MPa%. Here, the toughness is defined as the lower area of the curve up to the breaking point in the stress (MPa)-strain (%) curve (Stress-Strain Curve) obtained by the tensile test of the polymer material.

Example

Hereinafter, the present invention will be described in more detail through examples. Unless otherwise stated, "%" and "part" in an example are mass % and a mass part.

[moisture permeability]

experiment material:

The first adhesive layer alone (Example 1, Comparative Examples 1 and 2), or ^the second The materials of the laminate (Example 2 and Comparative Example 3) of the two adhesive layers, the functional layer, and the first adhesive layer were used as test materials.

Determination method of moisture permeability:

Using a water vapor permeability meter ["Lyssy 80-4000" manufactured by Systech Illinois (UK) Co., Ltd., based on JIS K7129-1:2019 (humidity sensor method)], in a measurement area of 0.07 to 51 cm ² , the temperature of the permeation cell is 40 ℃, the relative humidity of the high humidity room is 90%RH, the measurement start threshold of the low humidity room is set to the relative humidity of 9.7%RH, and the measurement is started, and the relative humidity of the low humidity room is changed from 9.9%RH to 10.1 The time required for %RH is measured, and the moisture permeability is calculated as the water vapor permeability.

[Evaluation of deiodination]

As shown in Figure 3, the polarizing plate with the adhesive layer is cut into a rectangle with a size of 120 mm (L2) × 60 mm (L1), so that when the protective film A side (A side) is set to the upper side, the polarizing plate The angle α of the absorption axis T with respect to the long side L2 is 45°, bonded to an alkali-free glass plate [manufactured by Corning, trade name "Eagle-XG"], and placed in an environment with a temperature of 65°C and a humidity of 90%RH 168 hours. Then, a polarizing plate having a relationship of crossed Nicols was attached to the non-alkali glass surface opposite to the tested polarizing plate with an adhesive layer, observed with an optical microscope, and the observed image was stored. As an optical microscope, "VHX-500" manufactured by Keyence Corporation was used. An example of the observation image obtained by observing the polarizing plate with an adhesive layer with an optical microscope is shown in FIG. 4 in this way. This observation image is an observation image of a polarizing plate with an adhesive layer obtained in Example 1 described later.

In this FIG. 4 , when there is a straight line indicated by an arrow from the end portion 50 of the polarizing plate with an adhesive layer inwardly (the straight line drawn in white along the vertical direction from the end portion 50 ), it can be seen that There are deiodination regions 51 and regions where deiodination has not occurred (non-deiodination regions) 52 .

[Measurement of deiodination amount by image processing]

The observed image under the microscope shown in Fig. 4 is a grayscale image (Japanese: グレ一图) converted into black and white 256 grayscale (Japanese: tone) (0 to 255) using the image analysis software "ImageJ (free software)" . The method of converting to black and white 256 grayscale (0-255) uses the method of averaging RGB values. FIG. 5 shows curve data obtained by plotting gradation along a straight line drawn in white on the observed image converted into the black-and-white 256 gradation shown in FIG. 4 . With respect to the end portion 50 vertical direction (arrow among Fig. 4) of the polarizing plate with adhesive layer, the middle point (middle of the deiodination gradation) of the deiodination region 51 and the non-deiodination region 52 is defined as For the deiodination end of the polarizing plate with an adhesive layer ( FIG. 5 ), the distance (μm) from the end 50 of the polarizing plate with an adhesive layer to the deiodination end was measured as the deiodination distance. Table 1 shows the deiodination distance of the polarizing plate with an adhesive layer. The smaller the deiodination distance, the narrower the deiodination range, and the better the heat and humidity resistance.

[curl measurement]

As a pellicle, AY-638 manufactured by Fujimori Industry Co., Ltd. (constituted by having an adhesive layer with a thickness of 15 μm on a polyester film with a thickness of 38 μm) was prepared.

A protective film was bonded to the protective film A of the polarizing plate with an adhesive layer to prepare a polarizing plate with a protective film. The absorption axis of the polarizer of the polarizing plate with a protective film is 45° with respect to the long side, cut into a rectangle with a size of 120mm x 60mm, and the obtained sample for curl measurement was placed at 23°C/55%RH Place it under ambient conditions for 15 hours.

Then, the separator was peeled from the first pressure-sensitive adhesive layer of the sample for curl measurement, and curl measurement was performed. After the sample was left to stand under the environment of 23°C/15%RH for 1 hour, the curl measurement was performed again, and the amount of change in the curl value was calculated.

Curl measurement will be described with reference to FIG. 6 . In the curl measurement, the sample 21 of the polarizing plate with a curled adhesive layer is placed on a reference surface 25 (for example, a flat surface on a desk, etc.) with its convex surface (protective film side) facing downward. In FIG. 6 , an imaginary surface 23 represented by a quadrilateral ABCD represents a surface assuming that the sample is not curled. One of the four corners A in the imaginary plane 23 is at the position of A1 in the sample 21 of the rolled polarizing plate with an adhesive layer, and the other corner C is in the sample 21 of the rolled polarizing plate with an adhesive layer is located at the position of C1, and the other angles B and D are located at the positions of B1 and D1 in the sample 21 of the curled polarizing plate, which is represented by the way that B1 and B are at the same position, and D1 and D are also at the same position (that is, That is, B and D in the four corners of the sample correspond to the state without warping). In practice, however, three or all of the four corners of the sample may be upturned. In this way, the curl height H from the reference plane 25 is measured for each of the four corners A1, B1, C1, and D1 of the sample. The maximum value among the upturn heights of the four corners is determined, and this maximum value is taken as the curl value of the sample.

[Single side protection polarizing plate]

(production of polarizer)

A polyvinyl alcohol film with a thickness of 20 μm, a degree of polymerization of 2400, and a degree of saponification of 99% or more is uniaxially stretched on a hot roll to a stretching ratio of 4.1 times. In a dyeing bath of 0.05 parts by mass of iodine and 5 parts by mass of potassium iodide, it was immersed at 28° C. for 60 seconds.

Next, it was immersed at 64 degreeC for 110 second in the boric-acid aqueous solution 1 containing 5.5 mass parts of boric acids and 15 mass parts of potassium iodide per 100 mass parts of water. Next, it was immersed at 67 degreeC for 30 second in the boric-acid aqueous solution 2 containing 5.5 mass parts of boric acids and 15 mass parts of potassium iodide per 100 mass parts of water. Then, it was washed with pure water at 10° C. and dried to obtain a polarizing plate. The obtained polarizing plate had a thickness of 8 μm and a boron content of 4.3% by weight.

(Preparation of water-based adhesive)

3 parts by mass of carboxy-modified polyvinyl alcohol (Kuraray Co., Ltd., trade name "KL-318") was dissolved in 100 parts by mass of water, and a polyamide epoxy-based additive as a water-soluble epoxy resin was added to the aqueous solution. (Taoka Chemical Industry Co., Ltd., trade name "Sumirez Resin (registered trademark) 650 (30), aqueous solution with a solid content concentration of 30% by weight) 1.5 parts by mass to prepare a water-based adhesive.

(Protective film A and release film B)

As the protective film A, a stretched film made of a cyclic polyolefin resin having a thickness of 25 μm and a hard coat layer having a thickness of 3 μm (manufactured by Nippon Paper Co., Ltd., trade name “COP25ST-HC”) were used.

As the release film B, a cellulose triacetate film (manufactured by Fujifilm Corporation, "TD80UL") was used. The thickness of the release film was 80 μm, and the moisture permeability was 502 g/m ² ·24 hr.

(Production of single-sided protective polarizing plate)

While conveying the prepared polarizing plate continuously, the protective film A was continuously unwound from the roll of the protective film A, and the peeling film B was continuously unwound from the roll of the peeling film B. A water-based adhesive is injected between the polarizer and the corona-treated protective film A, and pure water is injected between the polarizer and the release film B, and passed through the bonding roller to obtain a protective film A/water-based adhesive. A laminated film formed of agent/polarizer/pure water/peeling film B. The laminated film is transported, and heat-treated in a drying oven at 80°C for 300 seconds to dry the water-based adhesive, and to volatilize and remove the pure water present between the polarizer and the release film B to obtain a release film with a tape single-sided protective polarizer. The peeling film B was peeled off from the single-sided protective polarizing plate with a peeling film to obtain a single-sided protective polarizing plate.

[Production of retardation laminate]

(Production of the first retardation layer)

As the first retardation layer, a layer for imparting a retardation of λ/4 including a layer obtained by curing a nematic liquid crystal compound, that is, a first liquid crystal layer, an alignment film, and a transparent substrate, was used. It should be noted that the total thickness of the layer formed by curing the nematic liquid crystal compound and the alignment layer was 2 μm.

(Production of the second retardation layer)

10.0 parts by mass of polyethylene glycol di(meth)acrylate (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., A-600), trimethylolpropane triacrylate (Shin-Nakamura Chemical Co., Ltd.) Kogyo Co., Ltd., A-TMPT) 10.0 parts by mass, 1,6-hexanediol di(meth)acrylate (Shin-Nakamura Chemical Industry Co., Ltd., A-HD-N) 10.0 parts by mass, and as photopolymerization 1.50 parts by mass of Irgacure 907 (manufactured by BASF Corporation, Irg-907) as an initiator was dissolved in 70.0 parts by mass of methyl ethyl ketone as a solvent to prepare a coating solution for forming an alignment layer.

As the base film, prepare a strip-shaped cyclic polyolefin-based resin (COP) film (manufactured by Nippon Zeon Co., Ltd.) with a thickness of 20 μm, and apply an alignment layer-forming coating on one side of the base film with a bar coater. Coating solution.

After the applied coating layer was heat-treated at a temperature of 80°C for 60 seconds, it was irradiated with ultraviolet rays (UVB) at 220mJ/ ^cm2 to polymerize and cure the composition for forming an alignment layer, and formed on the base film. Alignment layer with a thickness of 2.3 μm.

Dissolve 20.0 parts by mass of a photopolymerizable nematic liquid crystal compound (manufactured by Merck, RMM28B) as a composition for forming a retardation layer, and 1.0 parts by mass of Irgacure 907 (manufactured by BASF, Irg-907) as a photopolymerization initiator The coating liquid for phase difference layer formation was prepared in 80.0 mass parts of solvent propylene glycol monomethyl ether acetates.

The coating liquid for phase difference layer formation was apply|coated on the alignment layer obtained before, and the heat treatment was given to the coating layer at the temperature of 80 degreeC for 60 second. Then, ultraviolet rays (UVB) were irradiated at 220 mJ/cm ² to polymerize and cure the composition for forming a retardation layer to form a second liquid crystal solidified layer with a thickness of 0.7 μm on the alignment layer. Thus, a 3-micrometer-thick second retardation layer including an alignment layer and a second liquid crystal solidified layer was obtained on the base film.

(Fabrication of Retardation Laminated Body)

The first retardation layer and the second retardation layer were bonded with an ultraviolet curable adhesive (thickness 1 μm) so that the respective liquid crystal layers (the surface opposite to the base film) became the bonded surface. Next, ultraviolet rays were irradiated to cure the ultraviolet curable adhesive, and a retardation laminate including two retardation layers, a first retardation layer and a second retardation layer, was produced. The thickness of the retardation laminate including the first retardation layer, the ultraviolet curable adhesive layer, and the second retardation layer was 6 μm.

(first adhesive layer)

Adhesive layer (1): An adhesive layer having a moisture permeability of 930 g/(m ² ·day) and a thickness of 25 μm was prepared.

Adhesive layer (2): An adhesive layer having a moisture permeability of 2000 g/(m ² ·day) and a thickness of 25 μm was prepared.

Adhesive layer (3): An adhesive layer having a moisture permeability of 160 g/(m ² ·day) and a thickness of 25 μm was prepared.

(second adhesive layer)

An adhesive layer having a moisture permeability of 4000 g/(m ² ·day) and a thickness of 5 μm was prepared.

<Example 1>

The pressure-sensitive adhesive layer (1) was bonded to the polarizer side of the prepared single-sided protective polarizing plate, and the separator was peeled off to obtain the polarizing plate with the pressure-sensitive adhesive layer of Example 1. The polarizing plate with an adhesive layer of Example 1 had the structure shown in FIG. 1 . The results are shown in Table 1. The moisture permeability was measured for the adhesive layer alone.

＜Comparative example 1＞

In Example 1, except having used the adhesive layer (2) instead of the adhesive layer (1), it carried out similarly to Example 1, and produced the polarizing plate with an adhesive layer. The results are shown in Table 1. The moisture permeability was measured for the adhesive layer alone.

＜Comparative example 2＞

In Example 1, except having used the adhesive layer (3) instead of the adhesive layer (1), it carried out similarly to Example 1, and produced the polarizing plate with an adhesive layer. The results are shown in Table 1. The moisture permeability was measured for the adhesive layer alone.

[Table 1]

<Example 2>

The second pressure-sensitive adhesive layer was bonded to the polarizer side of the produced single-sided protective polarizing plate, and the spacer was peeled off.

The surface of the second pressure-sensitive adhesive layer after peeling the spacer and the first liquid crystal solidified layer side of the retardation laminate after removing the transparent substrate were bonded together, and the substrate film of the second retardation layer was peeled off. The pressure-sensitive adhesive layer (1) is attached to the surface after peeling the base film. The polarizing plate with an adhesive layer of Example 2 had the structure shown in FIG. 2 . The results are shown in Table 2. The water vapor transmission rate was measured about the laminated body of the 2nd pressure-sensitive adhesive layer, the functional layer, and the 1st pressure-sensitive adhesive layer.

＜Comparative example 3＞

In Example 2, except having used the adhesive layer (3) instead of the adhesive layer (1), it carried out similarly to Example 1, and produced the polarizing plate with an adhesive layer. The results are shown in Table 2. The water vapor transmission rate was measured about the laminated body of the pressure-sensitive adhesive layer and the functional layer bonded together.

[Table 2]

Explanation of reference signs

11 Protective film, 12 Adhesive layer, 10 Polarizer, 13 First adhesive layer, 14 Second adhesive layer, 15 Functional layer, 21 Sample of curled polarizing plate, 23 Imaginary plane, 25 Reference plane, 50 End of polarizing plate with adhesive layer, 51 Deiodination region, 52 Non-deiodination region, 100, 200 Polarizing plate with adhesive layer, T Transmission axis direction, A, B, C, D imaginary planes The corners of A1, B1, C1, D1 samples, and the curl height of H.

Claims (11)

1. A polarizing plate with an adhesive layer, which has: Polarizer, a protective film disposed on one side of the polarizer through an adhesive layer, and The first adhesive layer disposed on the other side of the polarizer, The polarizer is a film obtained by absorbing iodine on a hydrophilic polymer film, The moisture permeability of the first pressure-sensitive adhesive layer under conditions of a temperature of 40° C. and a relative humidity of 90% RH is not less than 180 g/(m ² ·day) and not more than 1500 g/(m ² ·day). 2. The polarizing plate with an adhesive layer according to claim 1, wherein, The first adhesive layer is a layer containing an adhesive containing a (meth)acrylic resin. 3. The polarizing plate with an adhesive layer according to claim 1 or 2, wherein, The thickness of the first adhesive layer is not less than 10 μm. 4. The polarizing plate with an adhesive layer according to any one of claims 1 to 3, wherein: The protective film is a film containing a cyclic polyolefin resin. 5. A laminate for a flexible image display device, comprising: The polarizing plate with an adhesive layer according to any one of claims 1 to 4, and Front panel or touch sensor. 6 . An image display device comprising the polarizing plate with an adhesive layer according to claim 1 . 7. A polarizing plate with an adhesive layer, comprising: polarizer, and a protective film disposed on one side of the polarizer via an adhesive layer, On the other side of the polarizer, a second adhesive layer, a functional layer, and a first adhesive layer are provided in order from the polarizer side, The functional layer is a single layer of a liquid crystal solidified layer, or a multilayer of two or more layers selected from a liquid crystal solidified layer, an alignment layer and a bonding layer, The polarizer is a film obtained by absorbing iodine on a hydrophilic polymer film, The moisture permeability of the laminate formed of the second adhesive layer, the functional layer, and the first adhesive layer under the conditions of a temperature of 40° C. and a relative humidity of 90% RH is 180 g/(m ² · day) to 1500 g/(m ² ·day). 8. The polarizing plate with an adhesive layer according to claim 7, wherein, The protective film is a film containing a cyclic polyolefin resin. 9. The polarizing plate with an adhesive layer according to claim 7 or 8, wherein, The functional layer includes a first liquid crystal solidified layer and a second liquid crystal solidified layer. 10. A laminate for a flexible image display device, comprising: The polarizing plate with an adhesive layer according to any one of claims 7 to 9, and Front panel or touch sensor. 11. An image display device comprising the polarizing plate with an adhesive layer according to any one of claims 7 to 9.

Images