JP2012247619A - Polarizing plate with retardation layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polarizing plate with a retardation layer capable of reducing crosstalk in stereoscopic image display.SOLUTION: A polarizing plate with a retardation layer includes: a polarizing plate having a polarizer and protective layers disposed on both sides of the polarizer, respectively; a retardation layer disposed on one side of the polarizing plate; a first adhesion layer disposed on the other side of the polarizing plate; and a second adhesion layer disposed between the polarizing plate and the retardation layer. The retardation layer includes multiple regions which have slow axes in directions different from each other in a predetermined pattern. The first adhesion layer is an adhesive composition capable of providing the strong adhesive strength by irradiation of electromagnetic waves or charged particle beams, contains an adhesive principal ingredient made of at least one monomer, and at least one polymerization initiator which causes polymerization reaction of the adhesive principal ingredient, and is formed of an adhesive composition which changes so that the adhesive strength has a maximum value, a minimum value and a value larger than the maximum value with the increase of the irradiation amount of electromagnetic waves or charged particle beams irradiated to the adhesive composition under a prescribed temperature environment.

Description

  The present invention relates to a polarizing plate with a retardation layer. More specifically, the present invention relates to a retardation layer-attached polarizing plate having a patterned retardation layer.

  Conventionally, a lot of researches have been made and put into practical use regarding technologies related to stereoscopic (three-dimensional) image display. The basic principle of stereoscopic display is by providing different images to the left and right eyes of the observer. As a technique related to stereoscopic image display, typically, a spectacle method in which an observer wears special spectacles or the like, and a naked eye method in which spectacles or the like are not worn are cited. In the eyeglass system, there are a time division system in which a left-eye image and a right-eye image are alternately switched and output, and a space division system in which left and right images having different polarization directions are output for each line of a liquid crystal cell. In the space division method, in order to output left and right images having different polarization directions for each line of the liquid crystal cell, it is necessary to develop a pattern-like phase difference corresponding to each line of the liquid crystal cell. As means for expressing a pattern-like phase difference, a phase difference plate (pattern retarder) having a pattern of regions having different slow axis directions is known (for example, Patent Document 1).

  The pattern retarder as described above is usually arranged further on the viewing side of the viewing-side polarizing plate in the liquid crystal display device for stereoscopic (three-dimensional) image display. However, there may be a problem that crosstalk occurs under conditions such as heating and humidification (particularly when the function of the pattern retarder is imparted to the viewing-side protective layer of the viewing-side polarizing plate). Crosstalk means that each of the left and right images is mixed into the other image.

Japanese Patent No. 3372016

  The present invention has been made to solve the above-described conventional problems, and an object of the present invention is to provide a polarizing plate with a retardation layer capable of reducing crosstalk in stereoscopic image display.

According to the present invention, a polarizing plate with a retardation layer is provided. The polarizing plate with a retardation layer of the present invention includes a polarizing plate having a polarizer and protective layers disposed on both sides of the polarizer, a retardation layer disposed on one side of the polarizing plate, and the polarizing plate. A first adhesive layer disposed on the other side of the liquid crystal and a second adhesive layer disposed between the polarizing plate and the retardation layer; and the retardation layers in different directions. A plurality of regions having a slow axis in a predetermined pattern; and the first adhesive layer is an adhesive composition that develops an adhesive force upon irradiation with electromagnetic waves or particle beams, comprising at least one monomer An adhesive main agent and at least one polymerization initiator that causes a polymerization reaction of the adhesive main agent, and an irradiation amount of electromagnetic waves or particle beams irradiated to the adhesive composition under a predetermined temperature environment Along with the increase, the adhesive force is a maximum value, a minimum value, a value larger than the maximum value. It is formed from an adhesive composition which changes to take.
Another polarizing plate with a retardation layer of the present invention includes a polarizing plate having a polarizer and protective layers respectively disposed on both sides of the polarizer, a retardation layer disposed on one side of the polarizing plate, A first adhesive layer disposed on the other side of the polarizing plate, and a second adhesive layer disposed between the polarizing plate and the retardation layer; the retardation layers are different from each other. A plurality of regions having a slow axis in a direction in a predetermined pattern; and the first adhesive layer is an adhesive composition that develops an adhesive force upon irradiation with electromagnetic waves or particle beams, and includes at least one kind Irradiation of an electromagnetic wave or particle beam irradiated to the adhesive composition under a predetermined temperature environment, comprising an adhesive main agent comprising a monomer and at least one polymerization initiator that causes a polymerization reaction of the adhesive main agent As the amount increases, the adhesive force changes from a maximum value to a minimum value. Then, after the adhesive force takes the minimum value, the adhesive force is further maintained in a temperature environment higher than the predetermined temperature environment, so that the adhesive force changes to take a value larger than the maximum value. Formed from an adhesive composition.
In a preferred embodiment, the time required for the adhesive force of the adhesive composition to reach the maximum value as the irradiation intensity of the electromagnetic wave or particle beam increases and / or the adhesion temperature increases, from the maximum value. The time required to change to the minimum value and the time required to change from the minimum value to a value greater than the maximum value are shortened.
In a preferred embodiment, the adhesive composition is liquid when the electromagnetic wave or the particle beam is not irradiated under the predetermined temperature environment.
In a preferred embodiment, at least one monomer contained in the adhesive main agent is a hydroxyl group, a carboxyl group, a cyano group, an amino group, an aliphatic cyclic hydrocarbon group, a heterocyclic group, an amide group, or a carboxylic acid ester. It is a photopolymerizable vinyl monomer having at least one group.
In a preferred embodiment, the at least one polymerization initiator is a photopolymerization initiator.
In a preferred embodiment, after the adhesive force of the adhesive composition changes to a value larger than the maximum value, the adhesive composition decreases to a value smaller than the maximum value by immersion in water.
In a preferred embodiment, the in-plane retardation Re (590) of the retardation layer is 90 nm to 190 nm.
In a preferred embodiment, the predetermined pattern of the retardation layer has a stripe shape in which two regions having slow axes in different directions are alternately arranged.
In a preferred embodiment, each of the two regions having the slow axis in the different directions corresponds to one line of the liquid crystal cell.
In a preferred embodiment, the protective layer on the side where the retardation layer of the polarizer is disposed is composed of a cellulose resin film.
According to another aspect of the present invention, a liquid crystal panel is provided. This liquid crystal panel has the above polarizing plate with a retardation layer.
According to another aspect of the present invention, a liquid crystal display device is provided. The liquid crystal display device includes the liquid crystal panel.

  According to the present invention, a polarizing plate with a retardation layer capable of reducing crosstalk in stereoscopic image display is obtained by combining an adhesive layer formed from a specific adhesive composition and a patterned retardation layer. be able to.

It is a schematic sectional drawing of the polarizing plate with a phase difference layer by preferable embodiment of this invention. It is a schematic plan view which shows an example of the pattern of the phase difference layer in the polarizing plate with a phase difference layer by preferable embodiment of this invention. It is a schematic diagram which shows the change of the adhesive force of the adhesive composition used by this invention. It is a schematic diagram which shows the change of the adhesive force of the conventional adhesive agent. It is a schematic sectional drawing of the liquid crystal panel by preferable embodiment of this invention.

  Hereinafter, although preferable embodiment of this invention is described, this invention is not limited to these embodiment.

(Definition of terms and symbols)
The definitions of terms and symbols in this specification are as follows.
(1) Refractive index (nx, ny, nz)
“Nx” is the refractive index in the direction in which the in-plane refractive index is maximum (ie, the slow axis direction), and “ny” is the direction orthogonal to the slow axis in the plane (ie, the fast axis direction). “Nz” is the refractive index in the thickness direction.
(2) In-plane retardation (Re)
The in-plane retardation (Re) means an in-plane retardation value of a layer (film) at 23 ° C., and a wavelength of 590 nm unless otherwise specified. Re is obtained by Re = (nx−ny) × d, where d (nm) is the thickness of the layer (film).
(3) Thickness direction retardation (Rth)
Thickness direction retardation (Rth) is a retardation value in the thickness direction of a layer (film) at a wavelength of 590 nm unless otherwise specified. Rth is determined by Rth = (nx−nz) × d, where d (nm) is the thickness of the layer (film).
(4) Adhesive The adhesive can be generally defined as a substance having the following properties.
(I) A semi-solid substance having a high viscosity and a low elastic modulus, and is bonded to an adherend by applying pressure.
(Ii) It is possible to peel from the adherend even after bonding.
(Iii) The state does not change during the binding process.
(5) Adhesive The adhesive can be generally defined as a substance having the following properties.
(I) Initially a fluid, low-viscosity liquid that, when applied to an adherend, sufficiently wets the adherend to increase the contact area and cure by light irradiation or heating. Combines with the adherend.
(Ii) Curing is achieved through an adhesive state due to an increase in light irradiation amount and heating amount.
(Iii) After bonding, it is impossible to peel both of the adherend and the adhesive without causing cohesive failure.
(Iv) The state changes irreversibly during the binding process (changes from liquid to solid).

A. FIG. 1 is a schematic sectional view of a polarizing plate with a retardation layer according to a preferred embodiment of the present invention. The polarizing plate with retardation layer 100 includes a polarizing plate 10, a retardation layer 30 disposed on one side (typically, a viewing side) of the polarizing plate 10, and a first disposed on the other side of the polarizing plate 10. Adhesive layer 41, and second adhesive layer 42 disposed between polarizing plate 10 and retardation layer 30. In the illustrated example, the polarizing plate 10 includes a polarizer 11 and protective layers 21 and 22 disposed on both sides of the polarizer 11, respectively. Typically, the polarizing plate with a retardation layer is laminated on the liquid crystal cell (typically, the viewing side) with the first adhesive layer 41 bonded thereto.

B. Polarizing plate The polarizing plate has at least a polarizer. The polarizing plate may further have a protective layer for the polarizer. Specifically, the polarizing plate may have a configuration in which protective layers are disposed on both sides of the polarizer, or may have a configuration in which the protective layer is disposed only on one side of the polarizer. In this specification, hereinafter, the protective layer 21 disposed on the side where the first adhesive layer 41 of the polarizer 11 is disposed is referred to as the first protective layer, and the protective layer disposed on the side where the retardation layer 30 is disposed. The layer 22 may be referred to as a second protective layer.

B-1. Polarizer Any appropriate polarizer may be adopted as the polarizer according to the purpose. For example, dichroic substances such as iodine and dichroic dyes are adsorbed on hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, and ethylene / vinyl acetate copolymer partially saponified films. And polyene-based oriented films such as a uniaxially stretched product, a polyvinyl alcohol dehydrated product and a polyvinyl chloride dehydrochlorinated product. Among these, a polarizer obtained by adsorbing a dichroic substance such as iodine on a polyvinyl alcohol film and uniaxially stretching is particularly preferable because of its high polarization dichroic ratio.

  A polarizer uniaxially stretched by adsorbing iodine to a polyvinyl alcohol film can be produced by, for example, dyeing polyvinyl alcohol in an aqueous solution of iodine and stretching it 3 to 7 times the original length. . If necessary, it may contain boric acid, zinc sulfate, zinc chloride or the like, or may be immersed in an aqueous solution such as potassium iodide. Further, if necessary, the polyvinyl alcohol film may be immersed in water and washed before dyeing.

  By washing the polyvinyl alcohol film with water, not only can the surface of the polyvinyl alcohol film be cleaned and the anti-blocking agent can be washed, but also the effect of preventing unevenness such as uneven dyeing can be obtained by swelling the polyvinyl alcohol film. is there. Stretching may be performed after dyeing with iodine, may be performed while dyeing, or may be dyed with iodine after stretching. The film can be stretched in an aqueous solution of boric acid or potassium iodide or in a water bath.

  The thickness of the polarizer is generally about 1 μm to 80 μm, preferably 5 μm to 40 μm.

  The boron content of the polarizer is preferably 3% by weight to 3.9% by weight, and more preferably 3.4% by weight to 3.9% by weight. Such a polarizer has a small dimensional change (shrinkage) under conditions such as heating and humidification, and can contribute to the reduction of crosstalk. When the boron content is less than 3% by weight, the water resistance may be insufficient. On the other hand, when the boron content exceeds 3.9% by weight, the durability may be insufficient. For example, when a heat cycle test is performed with a polarizing plate, breakage tends to occur in the direction of stretching of the polarizer. The boron content of the polarizer can be calculated as, for example, a weight fraction (%) of boron with respect to the weight of the polarizer by high-frequency inductively coupled plasma (ICP) emission spectroscopy. Boron is typically considered to be present in a polarizer in a state in which boric acid or a polyvinyl alcohol unit forms a cross-linked structure in the polarizer. Value.

B-2. Protective layer The protective layer is formed of any suitable film that can be used as a protective layer for a polarizer. Specific examples of the material as the main component of the film include cellulose resins such as triacetyl cellulose (TAC), polyester-based, polyvinyl alcohol-based, polycarbonate-based, polyamide-based, polyimide-based, polyethersulfone-based, and polysulfone-based materials. And transparent resins such as polystyrene, polynorbornene, polyolefin, (meth) acryl, and acetate. Further, thermosetting resins such as (meth) acrylic, urethane-based, (meth) acrylurethane-based, epoxy-based, and silicone-based or ultraviolet curable resins are also included. In addition to this, for example, a glassy polymer such as a siloxane polymer is also included. Moreover, the polymer film as described in Unexamined-Japanese-Patent No. 2001-343529 (WO01 / 37007) can also be used. As a material for this 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 nitrile group in the side chain For example, a resin composition having an alternating copolymer composed of isobutene and N-methylmaleimide and an acrylonitrile / styrene copolymer can be mentioned. The polymer film can be, for example, an extruded product of the resin composition.

The protective layer (second protective layer) 22 disposed on the side of the polarizer 11 where the retardation layer 30 is disposed is preferably composed of a cellulose-based resin, and more preferably composed of TAC. By using a cellulose-based resin (particularly TAC) as the protective layer 22, the dimensional change of the retardation layer due to the dimensional change of the polarizer is remarkably suppressed, and as a result, the crosstalk of the stereoscopic image display can be reduced well. . The protective layer 22 is preferably optically isotropic. In particular, it is preferable that the in-plane retardation Re is small. The linearly polarized light that has passed through the polarizer is typically converted into circularly polarized light by the retardation layer 30. However, the smaller the in-plane retardation of the protective layer 22, the better the conversion to circularly polarized light can be realized. Excellent stereoscopic image display can be realized. Specifically, the in-plane retardation Re (590) of the protective layer 22 is preferably 0 nm to 20 nm, more preferably 0 nm to 10 nm, and particularly preferably 0 nm to 6 nm. The thickness direction retardation Rth (590) of the protective layer 22 is preferably −100 nm to +100 nm, more preferably −70 nm to +70 nm, and particularly preferably −50 nm to +50 nm. Furthermore, the photoelastic coefficient (590) of the protective layer 22 is preferably 5.0 × 10 ⁻¹¹ m / N or less, more preferably 3.0 × 10 ⁻¹¹ m / N or less. When the photoelastic coefficient is within such a range, adverse effects on the stereoscopic image display can be suppressed.

  The thickness of the protective layer is preferably 20 μm to 100 μm.

C. Retardation layer The retardation layer can typically function as a λ / 4 plate. The λ / 4 plate can convert linearly polarized light having a specific wavelength into circularly polarized light (or circularly polarized light into linearly polarized light). The in-plane retardation Re (590) of such a retardation layer is preferably 90 nm to 190 nm, more preferably 100 nm to 170 nm, and further preferably 110 nm to 150 nm. The retardation layer preferably has a refractive index ellipsoid of nx>ny> nz or nx> ny = nz. In the present specification, “ny = nz” includes not only the case where ny and nz are exactly equal, but also the case where ny and nz are substantially equal.

  The retardation layer has a plurality of regions each having a slow axis in a different direction in a predetermined pattern. Typical examples of patterns include stripes, checkers, and mosaics. By having such a configuration, different images can be provided to the left and right eyes of the observer, and as a result, a three-dimensional (stereoscopic) image can be provided. In the present specification, for example, “the in-plane phase difference Re (590) is 140 nm” preferably means that the in-plane phase differences of the plurality of regions are each 140 nm. Typically, the retardation layer has two regions each having a slow axis in different directions in a predetermined pattern. Typically, the slow axis directions of the two regions are substantially orthogonal to each other. With such a configuration, the two regions can provide images having different polarization directions, and as a result, a good three-dimensional image can be provided.

  The predetermined pattern of the retardation layer preferably has a stripe shape in which two regions 31 and 32 each having a slow axis in different directions are alternately arranged as shown in FIG. The stripe direction may be the horizontal direction (left-right direction) of the display screen or the vertical direction (up-down direction). Similarly to the above, the slow axis directions of the two striped regions are substantially orthogonal to each other. Preferably, each of the two regions having the slow axis in the different directions corresponds to one line of the liquid crystal cell. In other words, the stripe width in the stripe pattern corresponds to one line of the liquid crystal cell. In this specification, “one line of a liquid crystal cell” refers to a vertical or horizontal line of pixels arranged in a matrix. The stripe pattern preferably has black stripes between adjacent regions. The black stripe can be preferably formed at a position corresponding to the black matrix of the liquid crystal cell. By providing black stripes, crosstalk can be further reduced.

  The slow axis directions of the respective regions having different slow axis directions in the retardation layer preferably have a relationship of substantially ± 45 ° with the absorption axis direction of the polarizer. If the in-plane retardation of the retardation layer is within the above preferred range and the slow axis direction of each region and the absorption axis direction of the polarizer are in such a relationship, the left eye image and the right eye image Since both of the images for use are circularly polarized light, a good stereoscopic image display can be realized.

  In one embodiment, the retardation layer comprises a plurality of regions each having a slow axis in a different direction formed by fixing a photocurable liquid crystal polymer in different alignment states on a base film. Have. Such a retardation layer is formed, for example, as follows: First, a photo-alignment film is formed on a base film, and an alignment regulating force is applied in a predetermined direction using a polarization exposure method. For example, a photo-alignment film having regions to which alignment regulating forces of + 45 ° and −45 ° are alternately applied to the stripe direction for each line of the liquid crystal cell is formed. Next, a photocurable liquid crystal polymer layer is formed on the photo-alignment film, and the photo-curable liquid crystal polymer layer is irradiated with ultraviolet rays to fix the alignment state of the liquid crystal polymer. (For example, two regions having + 45 ° and −45 ° slow axis directions alternately with respect to the stripe direction for each line of the liquid crystal cell). The in-plane retardation of the region can be adjusted in consideration of the in-plane retardation of the base film so that the in-plane retardation of the entire retardation layer is in the preferred range.

The linear expansion coefficient of the base film is preferably 5.0 × 10 ⁻⁴ (1 / ° C.) or less, more preferably 1.0 × 10 ⁻⁴ (1 / ° C.) or less. Examples of the material constituting the base film include a cyclic olefin resin, a polycarbonate resin, and a cellulose resin. The cyclic olefin-based resin is a general term for resins that are polymerized using a cyclic olefin as a polymerization unit, and is described in, for example, JP-A-1-240517, JP-A-3-14882, JP-A-3-122137, and the like. Resin. Specific examples include ring-opening (co) polymers of cyclic olefins, addition polymers of cyclic olefins, copolymers of cyclic olefins and α-olefins such as ethylene and propylene (typically random copolymers). And graft modified products in which these are modified with an unsaturated carboxylic acid or a derivative thereof, and hydrides thereof. Specific examples of the cyclic olefin include norbornene monomers. As said polycarbonate-type resin, arbitrary appropriate polycarbonate-type resins are used as long as the effect of this invention is acquired. For example, an aromatic polycarbonate composed of an aromatic dihydric phenol component and a carbonate component is preferably used.

  In another embodiment, the retardation layer may be formed from a polymer material containing a photoisomerization substance. Since the photoisomerized substance generates a structural isomer or a stereoisomer by light irradiation or the like, regions having different slow axis directions can be formed in a predetermined pattern by performing light irradiation in a predetermined pattern. The photoisomerizable material is typically any suitable photochromic compound having a photoisomerizable functional group. Specific examples include azobenzene compounds, benzaldoxime compounds, azomethine compounds, stilbene compounds, spiropyran compounds, spirooxazine compounds, fulgide compounds, diarylethene compounds, cinnamic acid compounds, retinal compounds, And hemithioindico compounds. Preferred are azobenzene compounds, spiropyran compounds, and cinnamic acid compounds, and particularly preferred are cinnamic acid compounds. Further, the photoisomerization substance may be a monomer or a polymer.

  Any appropriate polymer material can be adopted as the polymer material. Furthermore, the polymer material may preferably contain a polymerizable resin. By containing the polymerizable resin, the orientation of the photoisomerized substance can be fixed. In more detail, once the polymerizable resin is polymerized so as to fix the orientation of the photoisomerized substance by light irradiation or heating, the desired resin of the photoisomerization substance can be obtained even if further light irradiation or heating is performed. May not play a role in causing structural isomerization. That is, the polymerizable resin can always stably maintain the slow axis direction fixed in the retardation layer. Examples of such a polymerizable resin include a compound having an unsaturated double bond, a compound having an electrophilic group, a compound having a nucleophilic group, and a compound having a polymerizable liquid crystal structure.

  A method for forming a retardation layer using a polymer material containing a photoisomerization substance will be briefly described. First, a pretreatment sheet is formed from a composition containing the photoisomerization material, the polymer material, and, if necessary, a polysynthetic resin. Any appropriate method (for example, a solution casting method, a melt film forming method (melt extrusion method), a coating method) may be employed as a method for forming the pretreatment sheet. For example, when performing the melt film-forming method, the pretreatment sheet can be produced by melting the above composition at a predetermined temperature and casting it from a die to a cooling roll. The pretreatment sheet may be used in an unstretched state, but it can be preferably uniaxially stretched in a predetermined direction. By performing uniaxial stretching, the slow axis directions of the plurality of regions can be more evenly aligned by light irradiation described later. A method and conditions for uniaxial stretching (for example, a stretching ratio and a stretching temperature) can be appropriately selected by those skilled in the art.

  Next, the pretreatment sheet is irradiated with light having an irradiation intensity distribution to form a plurality of regions having different slow axis directions. As a method of irradiating light having an irradiation intensity distribution, a method of irradiating light through a mask having a predetermined pattern is typically mentioned. The irradiation light is preferably linearly polarized light. In this manner, it is possible to form a retardation layer having a plurality of regions each having a slow axis in a different direction in a predetermined pattern.

  The details of the retardation layer (retardation film) using a polymer material containing a photoisomerization substance are described in Japanese Patent No. 3372016, which description is incorporated herein by reference.

  The retardation layer is not limited to the above form, and any suitable form can be adopted as long as the effects of the present invention can be obtained. For example, a predetermined position in which a polyvinyl alcohol film is selectively amorphized in a plane to form a predetermined pattern (for example, a stripe pattern in which different regions in the slow axis direction are alternately arranged for each line). A pattern retarder film corresponding to a phase difference (for example, a half wavelength phase difference); on a layer in which a region of a predetermined wavelength (for example, a half wavelength) is formed in a predetermined pattern (for example, a stripe pattern), A pattern retarder film provided with a retardation layer having a predetermined wavelength (for example, ¼ wavelength) that is not patterned can be used as the retardation layer.

D. Adhesive layer In this specification, an adhesive layer means what joins the surface of an adjacent optical member, and integrates it with practically sufficient adhesive force and adhesion time.
D-1. First adhesive layer The first adhesive layer includes an adhesive main agent composed of at least one monomer and at least one polymerization initiator that causes a polymerization reaction of the adhesive main agent, and is irradiated with electromagnetic waves or particle beams. It is formed from the adhesive composition which expresses adhesive force by. The polarizing plate with a retardation layer of the present invention is bonded to and integrated with any appropriate optical member by the first adhesive layer surface.

  The glass transition temperature after polymerization of the adhesive main agent is preferably 50 ° C. or higher. When the glass transition temperature is 50 ° C. or higher, for example, when the polarizing plate with a retardation layer of the present invention is used in a liquid crystal panel, deformation such as contraction of the polarizer due to the heat of the backlight can be suppressed. As a result, crosstalk and display unevenness in stereoscopic image display can be suppressed. In addition, when the polarizing plate with a retardation layer of the present invention is used in an in-vehicle liquid crystal panel, the adhesiveness can be maintained even when the interior temperature of the vehicle becomes high, so that the heat resistance can be improved.

  The refractive index after polymerization of the adhesive main agent is preferably close to the refractive index of the adherend (that is, the first protective layer and the optical member) bonded through the first adhesive layer. It is further preferable to be in the middle. By using an adhesive composition containing such an adhesive main agent, reflection at the interface between the first adhesive layer and the adherend is reduced, so that the light utilization efficiency is improved and good visibility is obtained. obtain.

  As the monomer constituting the adhesive main agent, photopolymerizable having at least one of hydroxyl group, carboxyl group, cyano group, amino group, amide group, carboxylic acid ester group, aliphatic cyclic hydrocarbon group, or heterocyclic group Vinyl monomers are preferred. Considering the adhesion between the polarizing plate and the glass substrate, a (meth) acryloyl group-containing monomer or a photopolymerizable vinyl monomer having a carboxyl group, a cyano group, an amino group, an amide group, or a heterocyclic group is preferable. An acryloyl group-containing monomer is more preferred, a monofunctional (meth) acryloyl group-containing monomer is even more preferred, and a monofunctional (meth) acryloyl group-containing monomer having a polar group is particularly preferred. In the present specification, “(meth) acryloyl group” means an acryloyl group and / or a methacryloyl group.

  Examples of the (meth) acryloyl group-containing monomer include (meth) acrylamide monomers and (meth) acrylate monomers. Moreover, the (meth) acryloyl group containing monomer which has polar groups, such as a heterocyclic group, a hydroxyl group, and an amino group, is mentioned.

  Examples of the (meth) acrylamide monomers include hydroxymethyl (meth) acrylamide, hydroxyethyl (meth) acrylamide, hydroxypropyl (meth) acrylamide, dimethyl (meth) acrylamide, diethyl (meth) acrylamide, and N-methyl (meth) acrylamide. Etc. The (meth) acrylamide monomer has a polar group, thereby improving the hydrogen bonding property with the surface of the glass substrate, for example, and having a glass transition temperature of more than room temperature, water The adhesive strength can be reduced, so that it is easy to handle from the viewpoint of recycling, and the adhesive strength can be reduced without using various organic solvents.

  Examples of the (meth) acrylate monomer include (meth) acrylate monomers having a hydroxyl group, a heterocyclic group, and an aliphatic cyclic hydrocarbon group.

  Examples of the (meth) acrylate monomer having a hydroxyl group include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, and hydroxybutyl (meth) acrylate. The (meth) acrylate monomer having a hydroxyl group is preferable because it has a polar group, and thereby, for example, the hydrogen bonding property with the surface of the glass substrate is improved.

  Examples of the (meth) acrylate monomer having a heterocyclic group include glycidyl (meth) acrylate and tetrahydrofurfuryl (meth) acrylate. The (meth) acrylate monomer having a heterocyclic group is preferable because it has a polar group, and thereby, for example, the hydrogen bonding property with the surface of the glass substrate is improved.

  Examples of the (meth) acrylate monomer having an aliphatic cyclic hydrocarbon group include dicyclopentenyl (meth) acrylate, isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, and the like. Since the (meth) acrylate monomer having an aliphatic cyclic hydrocarbon group does not have a polar group, it does not have a polar group or a substrate having a weak polarity (for example, a cycloolefin substrate). Suitable for bonding.

  Examples of other polar group-containing monomers include acryloylmorpholine, acrylic acid, acrylamide, and acrylonitrile. The other polar group-containing monomer preferably has a polar group, and thereby, for example, improves the hydrogen bondability with the surface of the glass substrate.

  As said adhesive main agent, only 1 type of the said monomer may be used and it may be used in combination of 2 or more type. Further, the adhesive main component may contain the above monomer as a main component and other monomers other than the above as subcomponents. In this case, the ratio of the monomer to the adhesive main agent is preferably larger than 50 mol%.

  The adhesive main agent may be a liquid or dissolved in a liquid material under a predetermined temperature environment for curing the adhesive composition. In the present specification, the liquid state includes a liquid state having a high viscosity.

  Any appropriate polymerization initiator may be selected as the polymerization initiator depending on the purpose. Preferably, a photopolymerization initiator can be used. By using a photopolymerization initiator, a polymerization reaction can be caused by light, so that the adhesive force and state of the adhesive composition can be easily controlled, and deterioration and destruction of the adherend can be avoided. .

  Examples of the photopolymerization initiator include alkylphenone photopolymerization initiators, acylphosphine oxide photopolymerization initiators, titanocene photopolymerization initiators, and cationic photopolymerization initiators. As photopolymerization initiators using ultraviolet rays, benzoin photopolymerization initiator, benzophenone photopolymerization initiator, anthraquinone photopolymerization initiator, xanthone photopolymerization initiator, thioxanthone photopolymerization initiator, ketal photopolymerization initiator Agents and the like.

  Specific examples of the photopolymerization initiator include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone, α-hydroxy-α, α′-dimethylacetophenone, methoxyacetophenone, 2,2- Acetophenone compounds such as dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, 1-hydroxycyclohexylenylketone, 2-methyl-1- [4- (methylthio) -phenyl] -2-morpholinopropane-1; Benzoin ether compounds such as benzoin ethyl ether, benzoin isopropyl ether and anisoin methyl ether, α-ketol compounds such as 2-methyl-2-hydroxypropiophenone, ketal compounds such as benzyldimethyl ketal, 2-naphthalene Sulfonylk Aromatic sulfonyl chloride compounds such as Lido, photoactive oxime compounds such as 1-phenone-1,1-propanedione-2- (o-ethoxycarbonyl) oxime, benzophenone, benzoylbenzoic acid, 3,3′-dimethyl And benzophenone-based compounds such as -4-methoxybenzophenone and 3,3′-4,4′-tetra (t-butylperoxycarbonyl) benzophenone.

  As said photoinitiator, what has the light absorption wavelength is a wavelength which permeate | transmits any one of each structural material of the polarizing plate with a phase difference layer of this invention, and this polarizing plate is bonded. The photopolymerization initiator preferably has no absorption in the visible light region or has low absorbance in the visible light region after reacting with light. For example, when the polarizing plate with a retardation layer of the present invention is used in a liquid crystal display device, light having wavelengths near 440 nm, 530 nm, and 610 nm, which are the bright line peaks of the backlight, so as not to affect the hue at the time of visual recognition. Preferably, there is no absorption or low absorbance.

  The content of the polymerization initiator in the adhesive composition may be set to an appropriate amount in consideration of the reaction progress rate and the like. As a specific example, when hydroxyethyl acrylamide (HEAA) is used as an adhesive main agent and an acyl phosphine oxide photopolymerization initiator is used as a polymerization initiator, the adhesive composition contains a polymerization initiator with respect to 100 parts of HEAA. It is preferable to contain 0.3-3 parts.

  The adhesive composition may further include any appropriate additive depending on the purpose. Examples of the additive include various Si coupling agents, crosslinking agents, polymerization inhibitors, photosensitizers, conductive materials, fine particles having birefringence, surfactants, and curing agents.

  Specific examples of the curing agent include phenol resins, various imidazole compounds and derivatives thereof, hydrazide compounds, dicyandiamide, isocyanate compounds, and microcapsules thereof. For example, when a phenol resin is added as a curing agent, a phosphorus compound such as triphenylphosphine can be used in combination as a curing accelerator.

  The irradiated electromagnetic wave or particle beam is preferably an ultraviolet ray or an electromagnetic wave having a wavelength near the ultraviolet ray. When visible light is used, the polymerization reaction may proceed due to the influence of ambient light, making it difficult to control the reaction, absorption of visible light due to the residue of the polymerization initiator remains, and the adhesive composition may be colored. There are problems such as being. When infrared rays are used, there is a problem that a polymerization reaction proceeds due to heat and it becomes difficult to control the reaction.

  In the first embodiment, the adhesive composition has a maximum adhesive force as the electromagnetic wave or particle beam irradiated to the adhesive composition increases in a predetermined temperature environment. , A minimum value, and a value larger than the maximum value.

  In this specification, the predetermined temperature environment is the amount of heat obtained by subtracting the amount of heat dissipated from the adhesive composition from the sum of the amount of heat applied to the adhesive composition and the amount of heat generated by the polymerization reaction of the adhesive composition. However, it refers to a temperature environment in which a state where the amount of heat is not less than a predetermined amount of heat can be maintained for at least a predetermined time. Therefore, when it is under a predetermined temperature environment, this means that the adhesive composition is placed in an environment where it can be heated at a predetermined temperature for a certain time, and the heating temperature and the heating environment are taken into consideration. For example, when a laminate in which two adherends are bonded via an adhesive composition is heated in an open system where heat is dissipated, the adhesive force changes to take a maximum value and a minimum value. For this purpose, it is necessary to heat at a high temperature for a certain period of time as compared with the case of heating in a closed system without heat dissipation. The temperature of the adhesive composition when placed in a predetermined temperature environment needs to be close to or higher than the glass transition point of the adhesive composition.

  Further, in this specification, when the electromagnetic wave or particle beam irradiation intensity and irradiation amount are referred to, the electromagnetic wave or particle beam irradiation intensity and irradiation amount (that is, the irradiation source and the irradiation amount) on the laminate of the adherend and the adhesive composition. Meaning of irradiation intensity or irradiation amount of electromagnetic wave or particle beam measured between the laminates (hereinafter referred to as “measured irradiation intensity and irradiation amount”). Therefore, when the electromagnetic wave or particle beam reaches the adhesive composition through the adherend, the actually measured irradiation intensity and irradiation amount are the actual electromagnetic wave or particle beam irradiation intensity and irradiation amount (hereinafter referred to as the adhesive composition itself). And “theoretical irradiation intensity and dose”). For example, since the transmittance of light having a wavelength of 400 nm of a polarizing plate manufactured by Nitto Denko (VEGQ5724DU) is about 30%, the intensity and amount of light absorbed by the adhesive composition through this polarizing plate (theoretical irradiation intensity and (Irradiation amount) is about 30% of the irradiation intensity and irradiation amount (actual irradiation intensity and irradiation amount) of the light source.

  According to the first embodiment, it is used to control the temperature environment so that the adhesive composition is maintained at a predetermined temperature for a predetermined time, and to develop an adhesive force in a conventional adhesive. The adhesive strength for bonding the adherends together via the adhesive composition and the state of the adhesive composition by irradiating electromagnetic waves or particle beams having a lower intensity than the irradiation intensity Can be controlled. This will be described in detail below.

The adhesive force F for bonding the adherend 1 and the adherend 1 ′ (that is, the first protective layer and the optical member) through the layer of the adhesive composition (that is, the first adhesive layer) is , F1, f1 ′, f2, f3, and f3 ′ are defined as the minimum force.
Interfacial adhesive force f1, f1 ′: Adhesive body 1 or adhesive body 1 ′ is bonded to the adhesive composition layer Adhesive composition cohesive force f2: Adhesive composition inside the adhesive composition layer Forces acting between the molecules of the adherends Cohesive forces f3, f3 ′: forces acting between the molecules within the adherend 1 and the adherend 1 ′

  Of the adherend 1 and the adherend 1 ′, the layer of the adhesive composition, and the interface between the adherends 1 and 1 ′ and the layer of the adhesive composition, which part the adhesion state is destroyed This is determined by the magnitude relationship among f1, f1 ′, f2, f3, and f3 ′. The adhesion state between the adherend 1 and the adherend 1 ′ is broken at a portion where these forces are minimum. According to the strength of the force, the adherend 1, 1 'cohesive failure, the adherend 1, 1'-interfacial destruction of the adhesive composition layer, the adhesive composition layer cohesive failure, these It is divided into mixed destruction. Generally, since it is difficult to measure the adhesive force itself, the peel force is evaluated as the adhesive force. The peeling force is a value including the force required for plastic deformation of the adhesive composition layer at the time of peeling and the smaller one of the interfacial adhesive forces f1 and f1 '.

(Liquid state)
The layer of the adhesive composition is in a fluid liquid state when the electromagnetic wave or the particle beam is not irradiated and is at least in a first predetermined temperature environment, like the conventional adhesive. In this state, the adhesive force F is extremely low, and there is a possibility that the bonding positions of the two adherends 1 and 1 ′ bonded through the adhesive composition layer are easily shifted. At this time, the cohesive force f2 is extremely small as compared with f1, f1 ′, f3, and f3 ′.

(Adhesive state)
When the layer of the adhesive composition is irradiated with an electromagnetic wave or particle beam having an appropriate strength under the first predetermined temperature environment, the adhesive force F increases in accordance with the irradiation amount of the electromagnetic wave or particle beam (that is, aggregation). Force f2 is increased). When the irradiation amount is further increased, the adhesive force F changes so as to decrease after reaching the maximum value. The state of the layer of the adhesive composition when the adhesive force F takes a value within a predetermined range including the maximum value according to the irradiation amount is similar to that of the conventional pressure-sensitive adhesive, that is, not completely cured. A viscoelastic body having a high viscosity and a low elastic modulus. In such a state, the adhesive composition layer develops an adhesive force by pressure, and the two adherends 1 and 1 ′ bonded through the layer are less likely to be displaced. It is possible to suppress the occurrence of misalignment. At this time, the cohesive force f2 has a magnitude that does not deviate due to the force in the shearing direction at the time of bonding.

  When the peeling force is exerted between the two adherends 1 and 1 ′ when the adhesive force F takes a value within a predetermined range including the maximum value, the adhesive composition layer is deformed so as to stretch. The peel force is the sum of the interfacial adhesive force f1 or f1 ′ and the force necessary to deform the layer (the force required for plastic deformation of the layer of the adhesive composition that has become a viscoelastic body). When the upper limit is exceeded, one of the adherends 1 or 1 'and the layer peel off. Whether the peeling occurs at the interface between the adherend 1 and the layer or at the interface between the adherend 1 'and the layer depends on the sizes of f1 and f1'. At this time, since f2 is larger than f1 and f1 ', cohesive failure of the layer can be prevented. When one of the adherends 1 or 1 'is peeled off from the layer, the layer is in a state similar to that of a conventional pressure-sensitive adhesive, so that both can be reattached.

  In this specification, the state of an adhesive composition when it becomes a viscoelastic body which expresses the adhesive force F by pressure as mentioned above is called an adhesive-like state. In this state, the adhesive force F takes a value in a predetermined range that maximizes the maximum value. The predetermined value including the maximum value and the maximum value of the adhesive force F when the adhesive composition exhibits a pressure-sensitive adhesive state is the type of the adhesive main agent, the type and addition amount of the polymerization initiator, the electromagnetic wave or the particle beam. It depends on conditions such as irradiation intensity, wavelength and temperature environment.

(Lightly peeled state)
After the adhesive force F reaches the maximum value, when the electromagnetic wave or particle beam having an appropriate strength is further irradiated to the layer of the adhesive composition in the first predetermined temperature environment, the adhesive force F is After reaching the minimum value as the irradiation amount increases, it changes so as to increase again. The layer when the adhesive force F takes a value within a predetermined range including the minimum value according to the irradiation amount is in a cured state as compared with the pressure-sensitive adhesive state, but has not yet been completely cured. When the layer is in such a state, the two adherends 1, 1 ′ and the layer can be easily separated with a small force. Therefore, the two adherends 1 and 1 ′ bonded together can be peeled without damaging the adherend. At this time, the cohesive force f2 is further greater than that in the pressure-sensitive adhesive state, and either the interfacial adhesive force f1 or f1 ′ is considered to be extremely small as compared with f2. Since the layer is cured and the adhesive force F is extremely small, and there is almost no wetting and spreading of the adhesive composition to the adherend, after peeling the adherend 1 or 1 ′ and the layer, It is impossible to re-bond them together with an adhesive force that can maintain at least the bonded state as a product.

  In the present specification, as described above, at least one of the adherends 1 and 1 ′ and the layer of the adhesive composition can be peeled at the interface between the two without damaging the adherend. The state of the adhesive composition when showing the cured state is called a lightly peeled state. In this state, the adhesive force F takes a value in a predetermined range having a minimum value as a minimum value. Here, “can be peeled at the interface between the two without damaging the adherend” means that the layer of the adhesive composition and the layer of the adhesive composition without causing cohesive failure of the adherend Not only when the adherend is peeled off at the interface between the two, but also when the adhesive composition layer and the adherend are in a state where a part of the adhesive composition remains on the adherend after peeling. Including the case where it is peeled off. The minimum value and the predetermined range including the minimum value of the adhesive force F when the adhesive composition shows a lightly peeled state are the type of the adhesive main agent, the type and addition amount of the polymerization initiator, and the irradiation of electromagnetic waves or particle beams. It depends on conditions such as intensity, wavelength and temperature environment.

(Strong adhesion state)
After the adhesive force F has been increased through the minimum value, if the layer of the adhesive composition is further irradiated with an electromagnetic wave or particle beam having an appropriate strength under the first predetermined temperature environment, the electromagnetic wave or the particle beam As the irradiation amount increases, the adhesive force F increases, and finally reaches a value at least larger than the maximum value. At this time, the layer is in a cured state that is the same as or more advanced than the cured state in the lightly peeled state after the polymerization reaction of the adhesive main agent is almost completed, and the two adherends 1, 1 ′. Is firmly bonded through the layer. At this time, the cohesive force f2 is equal to or greater than f2 in the lightly peeled state, and the interfacial adhesive forces f1 and f1 ′ are larger than f2 in the pressure-sensitive adhesive state. At least at this point, the two adherends 1 and 1 ′ cannot be peeled off, and if forcible peeling is desired, the adherend 1 is dependent on the magnitude relationship between f 2, f 3, and f 3 ′. Alternatively, cohesive failure occurs either inside 1 'or inside the layer.

  In the present specification, the state of the adhesive composition when showing a cured state that is the same as or more advanced than the cured state in the lightly peeled state as described above is referred to as a strongly bonded state. In this state, the adhesive force F takes a value larger than the maximum value. The minimum value of the adhesive force F (that is, the minimum value in a range larger than the maximum value) when the adhesive composition shows a strong adhesion state is the type of the main adhesive agent, the type and addition amount of the polymerization initiator, the electromagnetic wave or the particles. It varies depending on conditions such as the irradiation intensity and wavelength of the line, and the temperature environment.

  As described above, the adhesive composition has a value of the adhesive force F by irradiating an electromagnetic wave or particle beam having a strength lower than that when using a conventional adhesive under a predetermined temperature environment. It changes as shown in FIG. 3 according to the increase of the irradiation amount of electromagnetic waves or particle beams. That is, the adhesive force F can take a minimum value through a maximum value and then change so as to be at least larger than the maximum value in accordance with an increase in the irradiation amount of electromagnetic waves or particle beams. In the present specification, the maximum value of the irradiation intensity of electromagnetic waves or particle beams that can change the adhesive force F of the adhesive composition as shown in FIG. 3 is referred to as “limit irradiation intensity”. When an electromagnetic wave or particle beam having an intensity greater than the limit irradiation intensity is irradiated, the adhesive force F changes without taking the maximum value and the minimum value as shown in FIG. The limit irradiation intensity varies depending on conditions such as the type of the adhesive main agent, the type and addition amount of the polymerization initiator, the temperature environment, and the wavelength of irradiation light. The limit irradiation intensity can be determined, for example, as in Production Example 2 described later.

  On the other hand, in the conventional adhesive, the value of the adhesive force F changes so as to increase without taking the maximum value and the minimum value by increasing the irradiation amount of the electromagnetic wave or the particle beam as shown in FIG. . That is, the conventional adhesive is directly in a strong adhesive state through an adhesive-like state due to an increase in the irradiation amount of electromagnetic waves or particle beams, and decreases after the adhesive force reaches a maximum value as in the above adhesive composition. Thus, a state in which the adherends can be easily separated from each other does not elapse.

  In the first embodiment, the change rate of the adhesive force F and the state of the adhesive composition is increased by changing the irradiation intensity of electromagnetic waves or particle beams and / or the temperature environment in which the adhesive composition is placed. Can do. Specifically, when the irradiation intensity of the electromagnetic wave or the particle beam is increased in a range lower than the limit irradiation intensity, the time required for the adhesive force F to reach the maximum value (or the adhesive composition becomes a pressure-sensitive adhesive state. Time), the time required to change from the maximum value to the minimum value (or the time until the adhesive composition becomes lightly peeled), and the minimum value to the maximum value (or a value greater than the maximum value). The time required to change to (or the time until the adhesive composition is in a strong adhesive state) can be shortened. For example, by doubling the irradiation intensity of electromagnetic waves or particle beams, the adhesive force F is maximized in about half the time (the adhesive composition at this time is in a pressure-sensitive adhesive state), and then the minimal value ( The adhesive composition at this time can be changed to a maximum value (or a value larger than the maximum value: the adhesive composition at this time is in a strong adhesive state) through a lightly peeled state. Similarly, these times can be shortened by changing the temperature environment in which the adhesive composition is placed and increasing the temperature of the adhesive composition while the polymerization reaction is in progress by irradiation with electromagnetic waves or particle beams. Can be done.

  In the second embodiment, the adhesive composition has a maximum adhesive strength as the electromagnetic wave or particle beam irradiated to the adhesive composition increases in a predetermined temperature environment. After the adhesive force takes the minimum value, the adhesive force is further maintained in a temperature environment higher than the predetermined temperature environment, so that the adhesive force is increased to the maximum value. It changes to take a value larger than the value.

  In said 2nd embodiment, the adhesive force F and state of subsequent adhesive composition can be changed without irradiating electromagnetic waves or a particle beam by changing temperature environment on the way. For example, after the adhesive force F reaches the minimum value through the maximum value due to the irradiation of the electromagnetic wave or the particle beam in the first predetermined temperature environment, the temperature of the adhesive composition is higher than that of the first predetermined temperature environment. The adhesive force F can be changed from a minimum value to a value greater than the maximum value by holding the pressure for 2 hours or more in a predetermined temperature environment of 2. In addition, after the adhesive force F takes the maximum value by irradiation with electromagnetic waves or particle beams in the first predetermined temperature environment, the adhesive composition is subjected to the second predetermined temperature higher than that of the first predetermined temperature environment. If the adhesive force F is held for a predetermined time or longer in a temperature environment, the adhesive force F can directly change from a maximum value to a value larger than the maximum value. In any case, the temperature of the adhesive composition needs to be close to or above its glass transition point.

  The reason why the second predetermined temperature environment is set higher than the first predetermined temperature environment is considered as follows. That is, when the adhesive force F is in the minimum value state (lightly peeled state), the curing reaction of the adhesive composition is almost completed, and the adhesive composition in this state can be further irradiated with electromagnetic waves or particle beams. The curing reaction does not progress much. However, by raising the temperature of the adhesive composition to the glass transition temperature or the vicinity thereof, the stress at the interface between the adherend and the adhesive composition is relaxed, and as a result, the adhesive force F is increased. Here, in order to increase the temperature of the adhesive composition in a state where no electromagnetic wave or particle beam is irradiated, that is, in a state where there is no influence of heat generation or radiant heat by absorbing the electromagnetic wave or particle beam, the second predetermined The temperature environment must be higher than the first predetermined temperature environment in which the electromagnetic wave or the particle beam is irradiated.

  In said 1st and 2nd embodiment, when irradiation of electromagnetic waves or particle beam is stopped, the said adhesive composition can maintain the state and adhesive force at the time of this stop. Moreover, the state and adhesive force may further change depending on the restart of irradiation and / or the temperature environment in which it is placed. Therefore, the first adhesive layer formed from the adhesive composition can be in any of the liquid state, the pressure-sensitive adhesive state, the light release state, or the strong adhesive state.

The first adhesive layer can have a high elastic modulus. The tensile elastic modulus at 20 ° C. of the first adhesive layer in the strongly bonded state can be, for example, 2 × 10 ⁸ Pa to ⁸ × 10 ¹⁰ Pa, preferably 4 × 10 ⁸ Pa to 4 × 10 ¹⁰ Pa. By having such an elastic modulus, the dimensional change due to the contraction of the polarizer or the like can be suppressed, and as a result, the crosstalk of the stereoscopic image display can be suitably reduced. Further, by having such an elastic modulus, the repulsive force becomes strong. Therefore, when the polarizing plate with a retardation layer of the present invention is bonded to the liquid crystal cell on the first adhesive layer surface, deformation of the polarizing plate itself can be suppressed even if force is applied to the surface of the polarizing plate. Indentation and destruction of the plate surface can be prevented.

  The first adhesive layer preferably has a high glass transition temperature (Tg). The glass transition temperature is preferably 50 ° C. or higher. By having such a glass transition temperature, deformation due to the contraction of the polarizer or the like can be suppressed, and as a result, the crosstalk of stereoscopic image display can be suitably reduced.

  The thickness of the first adhesive layer can be appropriately set according to the purpose. The thickness is preferably 2 μm to 40 μm, more preferably 2 μm to 30 μm, and particularly preferably 5 μm to 25 μm. By setting the thickness within such a range, an adhesive layer having appropriate adhesiveness can be obtained. Further, the crosstalk can be reduced by suppressing the contraction of the polarizer.

D-2. Second Adhesive Layer Examples of the material forming the second adhesive layer include a pressure-sensitive adhesive, an adhesive, and an anchor coat agent. The second adhesive layer may have a multilayer structure in which an anchor coat layer is formed on the surface of the adherend and an adhesive layer is formed thereon. Further, it may be a thin layer (also referred to as a hairline) that cannot be visually recognized.

  The thickness of the second adhesive layer can be appropriately set according to the purpose. The thickness is preferably 2 μm to 50 μm, more preferably 2 μm to 40 μm, and particularly preferably 5 μm to 35 μm. By setting the thickness within such a range, an adhesive layer having appropriate adhesiveness can be obtained.

  The shear modulus of elasticity of the second adhesive layer at 20 ° C. is preferably 30000 Pa to 1100000 Pa, more preferably 40000 Pa to 1000000 Pa, still more preferably 50000 Pa to 900000 Pa, and particularly preferably 50000 Pa to 90000 Pa.

  The transmittance of the second adhesive layer measured with light having a wavelength of 590 nm at 23 ° C. is preferably 90% or more. The theoretical upper limit of transmittance is 100%, and the practical upper limit is 96%.

  The gel fraction of the second adhesive layer is preferably 75% or more, more preferably 75% to 90%, and particularly preferably 80% to 85%. By setting the gel fraction within such a range, an adhesive layer having good adhesive properties can be obtained. The gel fraction can be adjusted depending on the type and content of the crosslinking agent used.

  The glass transition temperature (Tg) of the second adhesive layer is preferably −70 ° C. to −10 ° C., more preferably −60 ° C. to −15 ° C., and particularly preferably −50 ° C. to −20 ° C. is there. By setting the glass transition temperature in such a range, an adhesive layer having strong adhesion to the retardation layer can be obtained.

  The moisture content of the second adhesive layer is preferably 1.0% or less, more preferably 0.8% or less, particularly preferably 0.6% or less, and most preferably 0.4% or less. It is. The theoretical lower limit of moisture content is zero. By setting the moisture content in such a range, it is possible to obtain an adhesive layer in which foaming does not easily occur even in a high temperature environment.

  The second adhesive layer is preferably composed of an acrylic pressure-sensitive adhesive. The acrylic pressure-sensitive adhesive preferably contains a (meth) acrylic polymer and a peroxide. The (meth) acrylic polymer refers to a polymer or copolymer synthesized from an acrylate monomer and / or a methacrylate monomer. When the (meth) acrylic polymer is a copolymer, the arrangement state of the molecules is not particularly limited, and may be a random copolymer, a block copolymer, or a graft copolymer. It may be a coalescence. A preferable molecular arrangement state of the (meth) acrylic polymer is a random copolymer.

  Any appropriate peroxide can be used as the peroxide as long as radicals can be generated by heating to achieve crosslinking of the (meth) acrylic polymer. Examples of the peroxide include hydroperoxides, dialkyl peroxides, peroxyesters, diacyl peroxides, peroxydicarbonates, peroxyketals, and ketone peroxides. The amount of the peroxide is preferably 0.01 parts by weight to 1 part by weight, and more preferably 0.05 parts by weight to 0.8 parts by weight with respect to 100 parts by weight of the (meth) acrylic polymer. Particularly preferred is 0.1 to 0.5 parts by weight, and most preferred is 0.15 to 0.45 parts by weight. By setting the amount of the peroxide in such a range, an adhesive layer having appropriate stress relaxation properties and excellent thermal stability can be obtained.

E. Others In the polarizing plate with a retardation layer of the present invention, any appropriate surface treatment layer may be formed on the viewing side of the retardation layer depending on the purpose. Representative examples of the surface treatment layer include an antiglare layer, an antireflection layer, and a hard coat layer. Moreover, the polarizing plate with a retardation layer of the present invention may further have a release liner on the side of the first adhesive layer where the first protective layer is not provided, depending on the purpose.

  The antiglare layer is provided for the purpose of, for example, preventing a reduction in the visibility of transmitted light due to reflection of external light on the surface of the image display device. The antiglare layer can be formed by imparting a fine concavo-convex structure to the film surface to be formed. A typical example of a material for forming the antiglare layer is a transparent resin. Specific examples include ultraviolet curable resins containing acrylic resins such as isocyanuric acid triacrylate, pentaerythritol triacrylate, dipentaerythritol hexaacrylate, and urethane resins such as isophorone diisocyanate polyurethane. The provision of the fine concavo-convex structure is performed by any appropriate method. Typical examples include roughening (for example, sand blasting and embossing) and blending of fine particles. When fine particles are used, any appropriate fine particles can be adopted as the fine particles depending on the purpose. Preferably, it is a transparent fine particle. Specifically, the fine particles may be inorganic fine particles (for example, silica, alumina, titania, zirconia, tin oxide, indium oxide, cadmium oxide, or antimony oxide fine particles that may be conductive), and organic fine particles ( For example, it may be a crosslinked or uncrosslinked polymer fine particle). The average particle diameter of the fine particles is preferably 0.5 μm to 20 μm. The blending amount of the fine particles is preferably 2 parts by weight to 70 parts by weight, and more preferably 5 parts by weight to 50 parts by weight with respect to 100 parts by weight of the transparent resin.

  The hard coat layer is provided for the purpose of preventing scratches on the surface of a polarizing plate or the like disposed on the surface of the image display device. The hard coat layer is composed of a cured film having appropriate hardness and slipperiness. Examples of the material for forming the hard coat layer include a silicone resin in addition to the acrylic resin and the urethane resin that form the antiglare layer.

  The antireflection layer is provided for the purpose of preventing reflection of external light on the surface of the image display device. As the antireflection layer, an antireflection layer usually used in the art may be employed.

  The release liner is typically provided for the purpose of protecting the surface of the first adhesive layer in a pressure-sensitive adhesive state until it is used. Any appropriate release liner can be adopted as the release liner as long as it can be satisfactorily released from the first adhesive layer in the pressure-sensitive adhesive state. Specific examples include a polyethylene terephthalate film treated with a silicone release agent.

F. Manufacturing method of polarizing plate with retardation layer The polarizing plate with a retardation layer can be manufactured by laminating the respective constituent members. Any appropriate method can be adopted as the lamination method. In one embodiment, first, a polarizing plate is produced by laminating protective layers (first or second protective layer) on both sides of the polarizer. Each layer is laminated via any suitable adhesive layer. A retardation layer is laminated on the side of the obtained polarizing plate on which the second protective layer is disposed via a second adhesive layer. Next, a first adhesive layer is laminated on the side of the laminate on which the first protective layer is disposed. In consideration of the usage form of the polarizing plate with a retardation layer of the present invention, the laminated first adhesive layer is preferably in a liquid state or a pressure-sensitive adhesive state, and more preferably in a pressure-sensitive adhesive state.

  Any appropriate method can be adopted as a method of laminating the first adhesive layer in the pressure-sensitive adhesive state on the side where the first protective layer of the laminate is disposed. In this case, the method and order of the step of laminating the first adhesive layer on the laminate and the step of bringing the first adhesive layer into the pressure-sensitive adhesive state are not limited. For example, the adhesive composition in a liquid state is applied to the surface of the first protective layer of the laminate, and electromagnetic waves or particles having an intensity lower than the limit irradiation intensity under appropriate conditions, for example, under a predetermined temperature environment The method of irradiating a line | wire and making it an adhesive-like state is mentioned.

  Another method is to apply the above-mentioned adhesive composition in a liquid state on a release liner, irradiate an electromagnetic wave or particle beam under appropriate conditions to form a pressure-sensitive adhesive, and then apply the pressure-sensitive adhesive-like adhesive composition. A method of transferring a product to the surface of the first protective layer of the laminate, and applying the adhesive composition in a liquid state on a release liner, and then applying the release liner through the layer of the adhesive composition A method of laminating on the surface of the first protective layer of the laminate and then irradiating electromagnetic waves or particle beams under appropriate conditions to bring the adhesive composition into a pressure-sensitive adhesive state can be mentioned.

  In addition, the above adhesive composition in a liquid state is applied onto a release liner, and an electromagnetic wave or particle beam is irradiated under appropriate conditions to form a pressure-sensitive adhesive state; Then, another release liner is bonded to the side where no adhesive is provided; then, one of the release liners is peeled off, and the adhesive composition in a pressure-sensitive adhesive state is transferred to the surface of the first protective layer of the laminate. May be. Alternatively, the above adhesive composition in a liquid state is applied onto the release liner, and another release liner is laminated on the adhesive composition; then, the adhesive is irradiated with electromagnetic waves or particle beams under appropriate conditions. The adhesive composition may be brought into a pressure-sensitive adhesive state; thereafter, one of the release liners may be peeled off, and the pressure-sensitive adhesive-like adhesive composition may be transferred to the surface of the first protective layer of the laminate.

  In the above production method, for example, after the adhesive composition is brought into a pressure-sensitive adhesive state, the adhesive composition is prevented from being further irradiated with electromagnetic waves or particle beams by light shielding or the like. By maintaining the low environment, the first adhesive layer can be maintained for a certain period of time in the pressure-sensitive adhesive state.

G. Method for Using Polarizing Plate with Retardation Layer The polarizing plate with a retardation layer of the present invention is used by being bonded to any appropriate optical member by the first adhesive layer. As a bonding method, the following methods are possible. That is, (Step 1) Affixing a polarizing plate with a retardation layer to an optical member by a first adhesive layer that has been brought into an adhesive-like state by irradiation with electromagnetic waves or particle beams, and temporarily adhering (Step 2) (Step 3) If correction of bonding is not required, the first adhesive layer is brought into a strong adhesion state, and the polarizing plate with retardation layer and the optical member are completely adhered to each other. (Step 4) In the case where it is necessary to correct the bonding, the first adhesive layer is lightly peeled and the polarizing plate with retardation layer and the optical member are peeled off. According to such a method, since the optical member is not damaged at the time of peeling in (Step 4), the optical member can be reused. Examples of the optical member to which the polarizing plate with a retardation layer of the present invention is bonded include a liquid crystal cell.

  In the temporary bonding in (Step 1), the first adhesive layer is in a pressure-sensitive adhesive state and exhibits an adhesive force by pressure. Therefore, the polarizing plate with retardation layer and the optical member are bonded together by pressure. Can do.

  In (Step 2), the presence or absence of occurrence of misalignment of the above-mentioned bonding, biting of foreign matter or bubbles is confirmed.

  In (Step 3), the following method is preferably used as a method for bringing the first adhesive layer into a strong adhesion state. For example, with respect to the first adhesive layer that is in a pressure-sensitive adhesive state, an electromagnetic wave or particle beam in an amount larger than the amount necessary for making a lightly peeled state in a predetermined temperature environment than the limit irradiation intensity. A method of further irradiating at a low intensity; the first adhesive layer in a pressure-sensitive adhesive state is further irradiated with an electromagnetic wave or particle beam having an intensity lower than the limit irradiation intensity in a predetermined temperature environment, and a light peeling state And then maintaining the laminate of the polarizing plate with a retardation layer and the optical member in the electromagnetic wave of (Step 1) in a temperature environment at a temperature higher than the predetermined temperature environment. Or it is the method of hold | maintaining more than predetermined time in the temperature environment of the temperature higher than the temperature environment at the time of irradiation of particle beam.

  In (Step 4), the following method is preferably used as a method for bringing the first adhesive layer into a lightly peeled state. For example, with respect to the first adhesive layer that is in the pressure-sensitive adhesive state, an amount of electromagnetic waves or particle beams that is larger than the amount necessary to make the pressure-sensitive adhesive state in a predetermined temperature environment is more than the limit irradiation intensity. Is a method of further irradiating with low intensity.

  The polarizing plate with a retardation layer of the present invention comprises a laminate of the polarizing plate with a retardation layer and the optical member after the first adhesive layer is in a strongly bonded state and completely adhered to the target optical member. It can be easily peeled from the optical member by immersing in water. This is because the adhesive composition forming the first adhesive layer swells when immersed in water, and any one of the interfacial adhesive forces f1 and f1 ′ and the adhesive composition cohesive force f2 is reduced. This is considered to be because the adhesive force F becomes smaller. The adhesive force F at this time is at least smaller than the maximum value. Therefore, according to the polarizing plate with a retardation layer of the present invention, for example, it can be easily peeled from the liquid crystal cell at the time of recycling of the liquid crystal television, so that it is possible to reduce the environmental load and the recycling cost. The temperature of the water to immerse is not limited. When the water temperature is high, the adhesive force is reduced in a shorter time, and peeling becomes possible.

H. Liquid crystal panel The liquid crystal panel of this invention has the said polarizing plate with retardation layer. Preferably, the liquid crystal panel of the present invention includes a liquid crystal cell and the polarizing plate with a retardation layer disposed on the viewing side of the liquid crystal cell.

  FIG. 5 is a schematic cross-sectional view of a liquid crystal panel according to a preferred embodiment of the present invention. The liquid crystal panel 200 includes a liquid crystal cell 50, the retardation layer-attached polarizing plate 100 disposed on the viewing side of the liquid crystal cell 50, and a polarizing plate 10 ′ disposed on the backlight side of the liquid crystal cell 50. The polarizing plate with retardation layer 100 is disposed so that the retardation layer 30 is closer to the viewing side than the polarizing plate 10. The polarizing plate 10 ′ is disposed on the backlight side of the polarizer 11 ′, the third protective layer 21 ′ disposed between the liquid crystal cell 50 and the polarizer 11 ′, and / or the polarizer 11 ′. And a fourth protective layer 22 ′. As the third and fourth protective layers, the same film as the first protective layer can be adopted. Although not shown in the drawing, the liquid crystal panel 200 includes any appropriate other retardation that is disposed between the liquid crystal cell 50 and the polarizing plate 100 with a retardation layer and / or between the liquid crystal cell 50 and the polarizing plate 10 ′. A layer may be provided.

  The liquid crystal cell 50 includes a pair of substrates 51 and 51 'and a liquid crystal layer 52 as a display medium sandwiched between the substrates 51 and 51'. One substrate (color filter substrate) is provided with a color filter and a black matrix (both not shown). The other substrate (active matrix substrate) includes a switching element (typically TFT) (not shown) for controlling the electro-optical characteristics of the liquid crystal, and a scanning line (not shown) for supplying a gate signal to this switching element. A signal line (not shown) for supplying a source signal and a pixel electrode (not shown) are provided. Note that the color filter may be provided on the active matrix substrate side. A distance (cell gap) between the substrates 51 and 51 'is controlled by a spacer (not shown). An alignment film (not shown) made of, for example, polyimide is provided on the side of the substrates 51 and 51 ′ that contacts the liquid crystal layer 52.

  Any appropriate method can be adopted as a method of laminating the constituent members of the liquid crystal panel. When laminating a polarizing plate with a retardation layer and a liquid crystal cell, the first adhesive layer of the polarizing plate with a retardation layer is laminated on the substrate surface on the viewing side of the liquid crystal cell. As a method of bonding, (Step 1) a polarizing plate with a retardation layer is bonded to a substrate on the viewing side of a liquid crystal cell with a first adhesive layer that has been changed to an adhesive-like state by irradiation with electromagnetic waves or particle beams, and temporarily bonded. (Step 2) Inspecting whether or not the correction of the bonding is necessary, (Step 3) If the correction of the bonding is not necessary, the first adhesive layer is made in a strong adhesion state and the polarization with retardation layer The plate and the liquid crystal cell are completely bonded. (Step 4) When the bonding needs to be corrected, the first adhesive layer is lightly peeled and the retardation layer-attached polarizing plate and the liquid crystal cell are peeled off. The method including can be preferably exemplified. According to such a method, position shift at the time of bonding can be prevented. Furthermore, even when it is necessary to correct the bonding, the liquid crystal cell can be easily peeled without damaging it, which is advantageous in terms of reuse of the liquid crystal cell.

  As described in the above item G, the adhesive strength of the first adhesive layer in the strongly bonded state is greatly reduced by immersion in water. Therefore, in the above liquid crystal panel, even when the polarizing plate with a retardation layer and the liquid crystal cell are completely bonded, the liquid crystal panel can be easily peeled off by immersing the liquid crystal panel in water. Thus, when the liquid crystal panel is discarded, it is easy to collect the rare metal used and remove the retardation plate, which is advantageous in terms of recycling.

  Moreover, since the first adhesive layer in the strongly bonded state has a higher elastic modulus than the conventional pressure-sensitive adhesive layer, deformation of the polarizer and the polarizing plate can be prevented. Therefore, in the liquid crystal display device using the above-mentioned liquid crystal panel, the crosstalk of stereoscopic image display can be suitably reduced, and when a force is applied to the surface of the polarizing plate, the generation or destruction of a dent can be prevented.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited by these Examples. In Examples, unless otherwise specified, “parts” and “%” are based on weight. Each measuring method is as follows.

(1) Measurement of light irradiation intensity The light irradiation intensity (actual irradiation intensity) was measured between an irradiation source and an object to be irradiated using a measuring instrument (EYE UV METER UVPF-A1 manufactured by Aigraphic).
(2) Measurement of adhesive strength Using a tensile tester (manufactured by Shimadzu Corporation, Autograph, AG-IS), a 180 degree peel value (peeling) at room temperature (25 ° C.) is measured under the condition of a tensile speed of 300 mm / min. This was used as the adhesive strength.
(3) Measurement of elastic modulus Using a solid viscoelastic device RSAIII manufactured by TA Instruments, the elastic modulus was measured by applying a tensile stress to the sample in a strip shape. The measurement conditions are as follows.
Deformation mode: Pulling frequency: 1 Hz
Initial strain: 0.1%
Temperature: -60 ° C to 300 ° C

[Production Example 1]
An adhesive composition was prepared by adding and dissolving 1 part of a photopolymerization initiator (manufactured by Ciba Japan, Irgacure 819) to 100 parts of N- (2-hydroxyethyl) acrylamide monomer (manufactured by Kojin). In order to increase the dissolution rate, dissolution was performed by applying ultrasonic waves while heating at 50 ° C. The obtained adhesive composition had a Tg of 98 ° C. Here, since a TAC to which an ultraviolet absorber is added is used for a protective film of a polarizing plate (manufactured by Nitto Denko, VEGQ5724DU) used below, light having a wavelength of 380 nm or less hardly transmits the polarizing plate. Therefore, Irgacure 819, which absorbs visible light near 400 nm, was selected as the photopolymerization initiator.

  1 mL of the adhesive composition was dropped on a plate glass with a dropper, and a polarizing plate (manufactured by Nitto Denko, VEGQ5724DU) was overlaid thereon, and the polarizing plate and the plate glass were bonded together by pressing the polarizing plate with a hand roller. The thickness of the adhesive composition was set to 10 μm. The size of the plate glass was 150 mm × 50 mm, and the size of the polarizing plate was 140 mm × 40 mm.

  A glass plate with a polarizing plate attached is placed on a hot plate (ASONE, HHP-411) heated to 70 ° C. with the glass surface facing down, and an ultraviolet irradiation machine (made by Eye Graphics, UBX0801-01 output 8 kW (high pressure) Light was irradiated from the polarizing plate side by a mercury lamp)). In order to prevent the temperature of the polarizing plate and the glass from being heated more than necessary, a heat ray cut filter was mounted between the ultraviolet irradiation source and the polarizing plate.

The irradiation intensity of light was adjusted so that the actually measured irradiation intensity at a wavelength of 405 nm was 7 mW / cm ² . The irradiation intensity (theoretical irradiation intensity) of light that reaches the adhesive composition through the polarizing plate is about 30% of the actually measured irradiation intensity. Therefore, the irradiation intensity (theoretical irradiation intensity) to the adhesive composition is theoretically considered to be 7 mW / cm ² × 30% = about ² mW / cm ² . The relationship between the measured irradiation intensity and the theoretical irradiation intensity is the same in the following examples and manufacturing examples.

(1) Adhesive-like state By irradiating the liquid adhesive composition with light from the polarizing plate side for 2 seconds, the adhesive composition became an adhesive-like state. The adhesive-like state was continued for 5 seconds from the start of irradiation until 3 seconds passed from the start of the adhesive-like state. The actual irradiation dose of light from the start to the end of the pressure-sensitive adhesive state was 15 to 35 mJ / cm ² . The maximum value of the adhesive force was 12 N / 25 mm. Further, the reaction rate of the monomer when the adhesive force was the maximum value was about 57%.

(2) Lightly peeled state The adhesive composition became lightly peeled by irradiating the adhesive composition in a pressure-sensitive adhesive state with light from the polarizing plate side for 3 seconds or more. The light release state continued for 21 seconds from the start of irradiation (that is, from the liquid state) and until 16 seconds passed from the start of the light release state. The actual irradiation amount of light from the start to the end of the light release state was 35 to 150 mJ / cm ² . The minimum value of the adhesive force was 0.5 N / 25 mm. The reaction rate of the monomer when the adhesive force was the minimum value was about 87%.

(3) Strongly bonded state The adhesive composition was in a strongly bonded state by irradiating the lightly peeled adhesive composition with light from the polarizing plate side for 16 seconds or longer. A strong adhesion state was obtained by irradiation for 21 seconds or longer from the start of irradiation. The measured irradiation amount of light when the strong adhesion state was started was 150 mJ / cm ² . The maximum value of the adhesive force in the strong adhesive state was larger than the cohesive force of the protective layer included in the polarizing plate and the interfacial adhesive force between the protective layer and the polarizer. The reaction rate of the monomer when the irradiation amount was 300 mJ / cm ² was about 89%.

  Table 1 below shows the elastic modulus of the adhesive composition in the pressure-sensitive adhesive state, the light release state, and the strong adhesion state.

  As shown in Table 1, the adhesive composition has a high elastic modulus.

About the said adhesive composition, the conditions other than the irradiation intensity of light were made into the same conditions as the above, and the change of the state of the adhesive composition according to irradiation time when changing irradiation intensity was observed. As the irradiation intensity, the intensity at a wavelength of 405 nm was changed in the range of 1.5 to 35 mW / cm ² . The results are shown in Table 2. In Table 2, the x mark indicates that the adhesive composition is in a liquid state, the Δ mark is a pressure-sensitive adhesive state, the ◯ mark is a lightly peeled state, and the ◎ mark is a strong adhesive state.

  From Table 2, as the irradiation intensity increases, the time until the state of the adhesive composition becomes a pressure-sensitive adhesive state, the time until it becomes a lightly peeled state, and the time until it becomes a strong adhesive state are shortened. You can see that

[Production Example 2]
An adhesive composition was prepared by adding and dissolving 0.5 part of a photopolymerization initiator (manufactured by Ciba Japan, Irgacure 819) to 100 parts of N- (2-hydroxyethyl) acrylamide monomer (manufactured by Kojin). In order to increase the dissolution rate, dissolution was performed by applying ultrasonic waves while heating at 50 ° C. The obtained adhesive composition had a Tg of 98 ° C.

  1 mL of the above-mentioned adhesive composition was hung on a plate glass with a dropper, and a polarizing plate (VEGQ5724DU manufactured by Nitto Denko Corporation) cut to a width of 25 mm using a hand roller was bonded to the plate glass. The thickness of the adhesive composition was adjusted to 10 μm. The plate glass bonded with the polarizing plate was placed in an oven at 40 ° C., and light was irradiated from the polarizing plate side with the following irradiation intensity by an ultraviolet irradiation machine (manufactured by Eye Graphics, UBX0801-01 output 8 kW (high pressure mercury lamp)). . At this time, in order to prevent the temperature of the polarizing plate and the glass from being heated more than necessary, a heat ray cut filter was mounted between the irradiation source and the polarizing plate.

Found irradiation intensity of light, intensity of ^{7 mW} / ^cm 2 at a wavelength of ^{405nm, 14mW / cm 2, 21mW} / cm 2, 25.4mW / cm 2, 32.5mW / cm 2, 41mW / cm 2, 60mW / cm 2 Or 80 mW / cm ² . Table 3 shows the test results of the adhesion to glass when the irradiation time is changed at each irradiation intensity.

From Table 3, it can be seen that when the measured irradiation intensity is 41 mW / cm ² or less, the adhesive force changed to take a maximum value, a minimum value, and a value larger than the maximum value as the irradiation time increased. . When the actually measured irradiation intensity was 60 mW / cm ² or more, the adhesive force increased without taking the maximum value and the minimum value as the irradiation time increased. Therefore, the limit irradiation intensity regarding this adhesive composition can be 41 mW / cm ² .

[Production Example 3]
An adhesive composition was prepared by adding and dissolving 0.5 part of a photopolymerization initiator (manufactured by Ciba Japan, Irgacure 819) to 100 parts of hydroxymethylacrylamide monomer (manufactured by Tokyo Chemical Industry). In order to increase the dissolution rate, dissolution was performed by applying ultrasonic waves while heating at 50 ° C.

1 mL of the above-mentioned adhesive composition was dropped on a plate glass with a dropper, and a polarizing plate (manufactured by Nitto Denko, VEGQ5724DU) was superimposed thereon, and the polarizing plate and the plate glass were bonded together by pressing the polarizing plate using a hand roller. A glass plate with a polarizing plate bonded on a hot plate (ASONE, HHP-411) heated to 60 ° C. is placed with the glass side facing down, and an ultraviolet irradiation machine (Igraphics, UBX0801-01 output 8 kW (high pressure) Light was irradiated from the polarizing plate side by a mercury lamp)). In order to prevent the temperature of the polarizing plate and the glass from being heated more than necessary, a heat ray cut filter was mounted between the irradiation source and the polarizing plate. The actually measured irradiation intensity of light was adjusted so that the intensity at a wavelength of 405 nm was 14 mW / cm ² .

  When light was irradiated for 1.5 seconds to the laminated body which bonded the polarizing plate and the plate glass through the adhesive composition in a liquid state, the adhesive composition became an adhesive-like state. When the light was further irradiated for 10 seconds, the adhesive composition was in a lightly peeled state. The light release state was continued until 50 seconds passed from the start of the light release state. After that, when the temperature of the hot plate was raised to 120 ° C. and further irradiated with light for 60 seconds or more, the adhesive composition was in a strongly bonded state.

[Production Example 4]
An adhesive composition was prepared in the same manner as in Production Example 3 except that the hydroxymethylacrylamide monomer (manufactured by Tokyo Chemical Industry) was changed to the hydroxyethylacrylamide monomer (manufactured by Kojin). Tg of the obtained adhesive composition was 98 ° C.

  Under the same conditions as in Production Example 3, when the light is applied to the laminate obtained by bonding the polarizing plate and the plate glass through the liquid adhesive composition for 2 seconds, the adhesive composition becomes a pressure-sensitive adhesive state. It was. When the light was further irradiated for 10 seconds, the adhesive composition was in a lightly peeled state. The light release state was continued until 50 seconds passed from the start of the light release state. Furthermore, when light was irradiated for 60 seconds or more, the adhesive composition was in a strongly bonded state.

  Moreover, when light was irradiated for 2 seconds with respect to the laminated body which bonded the polarizing plate and the plate glass through the adhesive composition in the liquid state under the same conditions, the adhesive composition became an adhesive-like state. . Furthermore, when light was irradiated for 30 seconds, the adhesive composition was in a lightly peeled state. Thereafter, when the temperature of the hot plate was raised to 100 ° C. and only heating was performed for 300 seconds without irradiating light, the adhesive composition was in a strongly bonded state.

Further, where except for changing the irradiation intensity was 14 mW / cm ² to 80 mW / cm ² is irradiated with light to laminate as the same condition, the adhesive composition in liquid state from the start of irradiation 1. A strong adhesion was achieved in 5 seconds. Furthermore, even if irradiation time was lengthened, the adhesive composition remained in a strongly bonded state.

[Production Example 5]
An adhesive composition was prepared by adding and dissolving 0.5 part of a photopolymerization initiator (manufactured by Ciba Japan, Irgacure 819) to 100 parts of hydroxypropylacrylamide monomer (manufactured by Fluka) (including 50% water). In order to increase the dissolution rate, dissolution was performed by applying ultrasonic waves while heating at 50 ° C. Tg of the obtained adhesive composition was 74 ° C.

1 mL of the above adhesive composition was dropped on a plate glass with a dropper, and the plate glass was placed on a hot plate (manufactured by AS ONE, HHP-411) heated to 100 ° C. in order to evaporate water. After the evaporation of moisture, a polarizing plate (manufactured by Nitto Denko, VEGQ5724DU) was superimposed on the adhesive composition of the plate glass, and the polarizing plate and the plate glass were bonded together using a hand roller. A glass plate with a polarizing plate bonded on a hot plate (ASONE, HHP-411) heated to 100 ° C. is placed with the glass surface facing down, and an ultraviolet irradiation machine (manufactured by Eye Graphics, UBX0801-01 output 8 kW (high pressure) Light was irradiated from the polarizing plate side by a mercury lamp)). In order to prevent the temperature of the polarizing plate and the glass from being heated more than necessary, a heat ray cut filter was mounted between the irradiation source and the polarizing plate. The actually measured irradiation intensity of light was adjusted so that the intensity at a wavelength of 405 nm was 14 mW / cm ² .

  When light was irradiated for 1 second with respect to the laminated body which bonded the polarizing plate and the plate glass through the adhesive composition in the liquid state, the adhesive composition became an adhesive-like state. When the light was further irradiated for 10 seconds, the adhesive composition was in a lightly peeled state. Furthermore, when light was irradiated for 20 seconds or more, the adhesive composition was in a strongly bonded state.

[Production Example 6]
An adhesive composition was prepared in the same manner as in Production Example 3 except that the hydroxymethylacrylamide monomer (Tokyo Kasei) was changed to the dimethylacrylamide monomer (Kojin). Tg of the obtained adhesive composition was 119 ° C.

  Under the same conditions as in Production Example 3, when the laminated body obtained by bonding the polarizing plate and the plate glass through the liquid adhesive composition is irradiated with light for 1 second, the adhesive composition becomes an adhesive-like state. It was. When the light was further irradiated for 10 seconds, the adhesive composition was in a lightly peeled state. The light release state was continued until 50 seconds passed from the start of the light release state. Furthermore, when light was irradiated for 60 seconds or more, the adhesive composition was in a strongly bonded state.

[Production Example 7]
An adhesive composition was prepared in the same manner as in Production Example 3 except that hydroxymethylacrylamide monomer (Tokyo Kasei) was changed to diethylacrylamide monomer (Kojin). Tg of the obtained adhesive composition was 81 ° C.

  Under the same conditions as in Production Example 3, when the laminated body obtained by bonding the polarizing plate and the plate glass through the liquid adhesive composition is irradiated with light for 1 second, the adhesive composition becomes an adhesive-like state. It was. When the light was further irradiated for 10 seconds, the adhesive composition was in a lightly peeled state. The light release state was continued until 20 seconds passed from the start of the light release state. Furthermore, when light was irradiated for 30 seconds or more, the adhesive composition was in a strongly bonded state.

[Production Example 8]
An adhesive composition was prepared by adding and dissolving 0.5 part of a photopolymerization initiator (manufactured by Ciba Japan, Irgacure 819) to 100 parts of an acrylic acid monomer (manufactured by Toa Gosei). In order to increase the dissolution rate, dissolution was performed by applying ultrasonic waves while heating at 50 ° C. Tg of the obtained adhesive composition was 106 ° C.

A silane coupling agent (manufactured by Shin-Etsu Chemical) was applied to the plate glass with a spin coater and heated at 100 ° C. for 1 minute. 1 mL of the adhesive composition was dropped onto the plate glass with a dropper, and a polarizing plate (manufactured by Nitto Denko, VEGQ5724DU) was superimposed thereon, and the polarizing plate and the plate glass were bonded together by pressing the polarizing plate using a hand roller. A glass plate with a polarizing plate bonded is placed on a hot plate (ASONE, HHP-411) heated to 80 ° C. with the glass surface facing down, and an ultraviolet irradiation machine (IGraphics, UBX0801-01 output 8 kW (high pressure) Light was irradiated from the polarizing plate side by a mercury lamp)). In order to prevent the temperature of the polarizing plate and the glass from being heated more than necessary, a heat ray cut filter was mounted between the irradiation source and the polarizing plate. The actually measured irradiation intensity of light was adjusted so that the intensity at a wavelength of 405 nm was 14 mW / cm ² .

  When light was irradiated for 1 second with respect to the laminated body which bonded the polarizing plate and the plate glass through the adhesive composition in the liquid state, the adhesive composition became an adhesive-like state. When the light was further irradiated for 10 seconds, the adhesive composition was in a lightly peeled state. The light release state was continued until 50 seconds passed from the start of the light release state. Furthermore, when light was irradiated for 60 seconds or more, the adhesive composition was in a strongly bonded state.

[Production Example 9]
An adhesive composition was prepared in the same manner as in Production Example 3 except that the hydroxymethylacrylamide monomer (Tokyo Kasei Co., Ltd.) was changed to 2-hydroxyethyl acrylate monomer (Nihon Shokubai Co., Ltd.). Tg of the obtained adhesive composition was −15 ° C.

  Under the same conditions as in Production Example 3, when the laminate is bonded with the polarizing plate and the plate glass through the adhesive composition in the liquid state, when the light is irradiated for 5 seconds, the adhesive composition becomes an adhesive-like state. It was. Furthermore, when light was irradiated for 30 seconds, the adhesive composition was in a lightly peeled state. The light release state was continued until 30 seconds passed from the start of the light release state. Furthermore, when light was irradiated for 60 seconds or more, the adhesive composition was in a strongly bonded state.

[Production Example 10]
An adhesive composition was prepared in the same manner as in Production Example 3 except that the hydroxymethylacrylamide monomer (manufactured by Tokyo Chemical Industry) was changed to an acrylonitrile monomer (manufactured by WAKO). The obtained adhesive composition had a Tg of 97 ° C.

  Under the same conditions as in Production Example 3, when the laminated body obtained by bonding the polarizing plate and the plate glass through the liquid adhesive composition is irradiated with light for 1 second, the adhesive composition becomes an adhesive-like state. It was. The adhesive-like state was continued until 9 seconds passed from the start of the adhesive-like state. Furthermore, when light was irradiated for 15 seconds, the adhesive composition was in a lightly peeled state. The light release state was continued until 105 seconds passed from the start of the light release state. Further, when the light was irradiated for 120 seconds or more, the adhesive composition was in a strong adhesive state.

[Production Example 11]
An adhesive composition was prepared in the same manner as in Production Example 3 except that hydroxymethylacrylamide monomer (Tokyo Kasei) was changed to acryloylmorpholine monomer (Kojin). Tg of the obtained adhesive composition was 145 ° C.

  Under the same conditions as in Production Example 3, when the laminated body obtained by bonding the polarizing plate and the plate glass through the liquid adhesive composition is irradiated with light for 1 second, the adhesive composition becomes an adhesive-like state. It was. Furthermore, when light was irradiated for 3 seconds, the adhesive composition was in a lightly peeled state. The light release state was continued until 57 seconds passed from the start of the light release state. Furthermore, when light was irradiated for 60 seconds or more, the adhesive composition was in a strongly bonded state.

[Production Example 12]
An adhesive composition was prepared in the same manner as in Production Example 3 except that hydroxymethylacrylamide monomer (Tokyo Kasei) was changed to N-methylmethacrylamide monomer (Tokyo Kasei).

  Except that the heating temperature by the hot plate was changed from 60 ° C. to 120 ° C., the light was applied to the laminate in which the polarizing plate and the plate glass were bonded through the liquid adhesive composition under the same conditions as in Production Example 3. Was irradiated for 30 seconds, the adhesive composition became an adhesive-like state. Furthermore, when light was irradiated for 90 seconds, the adhesive composition was in a light release state. Further, when the light was irradiated for 120 seconds or more, the adhesive composition was in a strong adhesive state.

[Production Example 13]
An adhesive composition was prepared in the same manner as in Production Example 3 except that hydroxymethylacrylamide monomer (Tokyo Kasei) was changed to glycidyl methacrylate monomer (Kishida). Tg of the obtained adhesive composition was 46 ° C.

  Under the same conditions as in Production Example 3, when light is irradiated for 30 seconds to the laminate in which the polarizing plate and the plate glass are bonded through the liquid adhesive composition, the adhesive composition becomes a pressure-sensitive adhesive state. It was. The pressure-sensitive adhesive state was continued until 90 seconds passed from the start of the pressure-sensitive adhesive state. Then, when the temperature of the hot plate was set to 80 ° C. and light was further irradiated for 30 seconds, the adhesive composition was in a lightly peeled state. The light release state was continued until 90 seconds passed from the start of the light release state. Furthermore, when light was irradiated for 240 seconds or more, the adhesive composition was in a strongly bonded state.

[Production Example 14]
An adhesive composition was prepared in the same manner as in Production Example 3 except that hydroxymethylacrylamide monomer (Tokyo Kasei) was changed to tetrahydrofurfuryl methacrylate monomer (Tokyo Kasei). Tg of the obtained adhesive composition was 60 ° C.

  Except that the heating temperature by the hot plate was changed from 60 ° C. to 120 ° C., the light was applied to the laminate in which the polarizing plate and the plate glass were bonded through the liquid adhesive composition under the same conditions as in Production Example 3. Was irradiated for 30 seconds, the adhesive composition became an adhesive-like state. The pressure-sensitive adhesive state continued until 30 seconds passed from the start of the pressure-sensitive adhesive state. Furthermore, when light was irradiated for 60 seconds, the adhesive composition was in a lightly peeled state. The light release state was continued until 60 seconds passed from the start of the light release state. Furthermore, when light was irradiated for 240 seconds or more, the adhesive composition was in a strongly bonded state.

[Production Example 15]
Adhesive in the same manner as in Production Example 4 except that hydroxyethylacrylamide monomer (manufactured by Kojin) was changed to a mixture of 50 parts hydroxyethylacrylamide monomer (manufactured by Kojin) and 50 parts of methyl methacrylate monomer (manufactured by WAKO). A composition was prepared.

  Under the same conditions as in Production Example 4, when the light is irradiated for 3 seconds to the laminate in which the polarizing plate and the plate glass are bonded via the liquid adhesive composition, the adhesive composition becomes a pressure-sensitive adhesive state. It was. The pressure-sensitive adhesive state continued until 27 seconds passed from the start of the pressure-sensitive adhesive state. When the light was further irradiated for 10 seconds, the adhesive composition was in a lightly peeled state. Furthermore, when light was irradiated for 20 seconds or more, the adhesive composition was in a strongly bonded state.

[Production Example 16]
An adhesive composition was prepared by adding and dissolving 0.5 part of a photopolymerization initiator (manufactured by Ciba Japan, Irgacure 819) to 100 parts of dicyclopentenyl acrylate (manufactured by Hitachi Chemical). In order to increase the dissolution rate, dissolution was performed by applying ultrasonic waves while heating at 50 ° C.

1 mL of the above adhesive composition is dropped onto a cycloolefin film “ZEONOR” (manufactured by ZEON Corporation) with a dropper, and then the cycloolefin film “ZEONOR” (manufactured by ZEON Corporation) is laminated on it using a hand roller to be a laminated film. Was made. The laminated film was placed on a hot plate (ASONE, HHP-411) heated to 120 ° C., and irradiated with light by an ultraviolet irradiator (manufactured by Eye Graphics, UBX0801-01 output 8 kW (high pressure mercury lamp)). In order to prevent the temperature of the film from being heated more than necessary, a heat ray cut filter was mounted between the irradiation source and the laminated film. The actually measured irradiation intensity of light was adjusted so that the intensity at a wavelength of 405 nm was 14 mW / cm ² .

  When the laminated film was irradiated with light for 15 seconds, the adhesive composition became an adhesive-like state. Furthermore, when light was irradiated for 30 seconds, the adhesive composition was in a lightly peeled state. Further, when the light was irradiated for 120 seconds or more, the adhesive composition was in a strong adhesive state.

[Example 1]
(Retardation layer)
A retardation film having two regions with different slow axis directions in a stripe pattern was produced as follows. A photo-alignment film is formed on a cycloolefin-based film (trade name “ZEONOR” manufactured by Nippon Zeon Co., Ltd.), and + 45 ° and −45 ° with respect to the stripe direction for each line of the liquid crystal cell using a polarization exposure method. A photocurable liquid crystal polymer layer having a predetermined birefringence and a film thickness was formed on the photo-alignment film. Next, a retardation film corresponding to a λ / 4 plate having two stripe-patterned regions having different slow axis directions by irradiating ultraviolet rays to cure the photocurable liquid crystal polymer and fixing its alignment state. (Pattern retarder film) was produced.
(Polarizer)
A polarizing plate (manufactured by Nitto Denko, VEGQ5724DU) having a configuration of protective layer (TAC film) / polarizer / protective layer (TAC film) was used.
(Adhesive composition)
The adhesive composition prepared in Production Example 2 was used.
(Liquid crystal cell)
A liquid crystal cell obtained by peeling the polarizing plate on the viewing side from the liquid crystal panel of a liquid crystal television (manufactured by Sharp, LC-32DE5) was used.

The pattern retarder film obtained above was bonded to one side of the polarizing plate via an acrylic pressure-sensitive adhesive (thickness: 23 μm). The adhesive composition was applied to the other surface using a bar coater to form a first adhesive layer having a thickness of 10 μm. Next, when light having a wavelength of 405 nm is irradiated from the first adhesive layer side in an oven at 40 ° C. for 1 ^second at an irradiation intensity of 30 mW / cm ² , the adhesive composition forming the first adhesive layer becomes an adhesive-like It became a state. Thereby, a polarizing plate with a retardation layer having a configuration of a first adhesive layer (pressure-sensitive adhesive state) / first protective layer / polarizer / second protective layer / second adhesive layer / retardation layer. Obtained.

The viewing side surface of the liquid crystal cell and the first adhesive layer surface of the polarizing plate with a retardation layer were bonded together. Then, an adhesive for forming the first adhesive layer by irradiating light having a wavelength of 405 nm from the polarizing plate side in an oven at 40 ° C. with an irradiation intensity of 14 mW / cm ² for 20 seconds (21 seconds from the start of irradiation). The composition became lightly peeled. Further, an adhesive for forming the first adhesive layer by irradiating light having a wavelength of 405 nm from the polarizing plate side in an oven at 80 ° C. for 40 seconds (61 seconds from the start of irradiation) at an irradiation intensity of 14 mW / cm ^2. The composition became strongly bonded.

  According to the liquid crystal panel obtained above, it was confirmed that crosstalk of stereoscopic image display was suppressed. Moreover, when this liquid crystal panel was immersed in 60 degreeC water for 1 day and taken out, the polarizing plate with a phase difference layer and a liquid crystal cell were able to be peeled easily.

  Further, when the liquid crystal panel is manufactured, the polarizing plate with a retardation layer is peeled off from the liquid crystal cell in a state where the adhesive composition forming the first adhesive layer is in a lightly peeled state. did it. At this time, the liquid crystal cell was not damaged.

[Comparative Example 1]
(Adhesive)
Acrylic adhesive was used. Using a hand roller on the pressure-sensitive adhesive layer side of the pressure-sensitive adhesive polarizing plate (manufactured by Nitto Denko, VEGQ1724DU) having a structure in which the acrylic pressure-sensitive adhesive layer is laminated on one side of the polarizing plate (manufactured by Nitto Denko, VEGQ5724DU) A laminated body is prepared by bonding, and when the obtained laminated body is irradiated with light of 400 nm while being heated under the same conditions as in Production Example 3, the adhesive strength of the adhesive is a maximum value and a minimum value even if the irradiation amount is increased. It did not change to take the value.

  A pattern retarder film similar to that in Example 1 was bonded to one side of a polarizing plate (manufactured by Nitto Denko, VEGQ5724DU) via an acrylic adhesive (thickness: 23 μm). An acrylic pressure-sensitive adhesive was applied to the other surface of the polarizing plate to form a pressure-sensitive adhesive layer having a thickness of 20 μm. Thereby, a polarizing plate with a retardation layer was obtained.

  A polarizing plate on both sides was peeled from a liquid crystal panel of a liquid crystal television (manufactured by SONY, BRAVIA, KDL-40V1) to obtain a liquid crystal cell. The polarizing plate with a retardation layer obtained above was bonded to the viewing side of the liquid crystal cell in the same manner as in Example 1. Subsequently, a polarizing plate (manufactured by Nitto Denko, VEGQ5724DU) was bonded to the backlight side of the liquid crystal cell via an acrylic adhesive (thickness 20 μm). At this time, the absorption axis of the polarizer was made to be orthogonal. Thereby, a liquid crystal panel was obtained.

  According to the liquid crystal panel obtained above, the crosstalk of the stereoscopic image display was not suppressed. In addition, in the liquid crystal panel, a larger force is required for peeling the polarizing plate with the retardation layer from the liquid crystal cell as compared with the liquid crystal panel of Example 1 in which the first adhesive layer is in a lightly peeled state. did. Moreover, even if it immersed in 60 degreeC water for 1 day, the adhesive force of the adhesive composition did not fall.

  Further, when the liquid crystal panel was heated at 80 ° C. for 100 hours, luminance unevenness occurred. Furthermore, the surface hardness of the polarizing plate was lower than that of the liquid crystal panel of Example 1. This is presumably because a depression was generated in the polarizing plate due to the pushing force because the adhesive was soft.

  The polarizing plate with a retardation layer of the present invention can be suitably used for a liquid crystal display device. In particular, it can be suitably used as a viewing side polarizing plate of a three-dimensional liquid crystal display device.

DESCRIPTION OF SYMBOLS 10 Polarizing plate 11 Polarizer 21 Protective layer 22 Protective layer 30 Retardation layer 41 First adhesive layer 42 Second adhesive layer 50 Liquid crystal cell 100 Polarizing layer with retardation layer 200 Liquid crystal panel

Claims (13)

A polarizing plate having a polarizer and protective layers respectively disposed on both sides of the polarizer;
A retardation layer disposed on one side of the polarizing plate;
A first adhesive layer disposed on the other side of the polarizing plate;
A second adhesive layer disposed between the polarizing plate and the retardation layer;
The retardation layer has a plurality of regions each having a slow axis in a different direction in a predetermined pattern;
The first adhesive layer is an adhesive composition that exhibits an adhesive force by irradiation with electromagnetic waves or particle beams,
An electromagnetic wave irradiated to the adhesive composition under a predetermined temperature environment, comprising: an adhesive main agent comprising at least one monomer; and at least one polymerization initiator that causes a polymerization reaction of the adhesive main agent. Formed from an adhesive composition that changes such that the adhesive force takes a maximum value, a minimum value, and a value greater than the maximum value as the dose of the particle beam increases;
Polarizing plate with retardation layer. A polarizing plate having a polarizer and protective layers respectively disposed on both sides of the polarizer;
A retardation layer disposed on one side of the polarizing plate;
A first adhesive layer disposed on the other side of the polarizing plate;
A second adhesive layer disposed between the polarizing plate and the retardation layer;
The retardation layer has a plurality of regions each having a slow axis in a different direction in a predetermined pattern;
The first adhesive layer is an adhesive composition that exhibits an adhesive force by irradiation with electromagnetic waves or particle beams,
An electromagnetic wave irradiated to the adhesive composition under a predetermined temperature environment, comprising: an adhesive main agent comprising at least one monomer; and at least one polymerization initiator that causes a polymerization reaction of the adhesive main agent. As the irradiation amount of the particle beam increases, the adhesive force changes so as to take a minimum value through a maximum value, and after the adhesive force takes the minimum value, the temperature is higher than that in the predetermined temperature environment. Formed from an adhesive composition that is further retained in the environment so that the adhesive force changes to take a value greater than the maximum value;
Polarizing plate with retardation layer.   The time required for the adhesive force of the adhesive composition to reach the maximum value changes from the maximum value to the minimum value as the irradiation intensity of electromagnetic waves or particle beams increases and / or the adhesion temperature increases. The polarizing plate with a retardation layer according to claim 1, wherein a time required for the change and a time required for changing from the minimum value to a value larger than the maximum value are shortened.   The polarizing plate with a retardation layer according to claim 1, wherein the adhesive composition is in a liquid state when the electromagnetic wave or the particle beam is not irradiated under the predetermined temperature environment.   At least one monomer contained in the adhesive main agent has at least one hydroxyl group, carboxyl group, cyano group, amino group, aliphatic cyclic hydrocarbon group, heterocyclic group, amide group, or carboxylic acid ester group. The polarizing plate with a retardation layer according to any one of claims 1 to 4, which is a photopolymerizable vinyl monomer.   The polarizing plate with a retardation layer according to claim 1, wherein the at least one polymerization initiator is a photopolymerization initiator.   The phase difference according to any one of claims 1 to 6, wherein the adhesive force of the adhesive composition is reduced to a value smaller than the maximum value by immersion in water after changing to a value larger than the maximum value. Layered polarizing plate.   The polarizing plate with a retardation layer according to any one of claims 1 to 7, wherein an in-plane retardation Re (590) of the retardation layer is 90 nm to 190 nm.   The polarizing plate with a retardation layer according to any one of claims 1 to 8, wherein the predetermined pattern of the retardation layer has a stripe shape in which two regions having slow axes in different directions are alternately arranged.   The polarizing plate with a retardation layer according to claim 1, wherein each of the two regions having a slow axis in the different direction corresponds to one line of the liquid crystal cell.   11. The polarizing plate with a retardation layer according to claim 1, wherein the protective layer on the side where the retardation layer of the polarizer is disposed is made of a cellulose resin film.   A liquid crystal panel comprising the polarizing plate with a retardation layer according to claim 1.   A liquid crystal display device comprising the liquid crystal panel according to claim 12.

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