KR20190118968A - Polarizing plate and display apparatus - Google Patents

Abstract

Provided is a circular polarizing plate having a polarizing plate and a retardation film. The retardation film includes a retardation layer, wherein the retardation film has a rotor elastic modulus of 15 gf/mm or more. The rotor elasticity modulus uses a needle whose tip diameter is 1 mmφ, 0.5 R to be measured by a test in which the rotor speed is 0.33 cm/sec.

Description

POLARIZING PLATE AND DISPLAY APPARATUS}

The present invention relates to a polarizing plate and a display device.

In recent years, an image display device typified by an organic electroluminescence (hereinafter also referred to as organic EL) display device is rapidly spreading. The circularly polarizing plate provided with a polarizer and retardation film ((lambda) / 4 plate) is mounted in an organic electroluminescence display. By disposing the circular polarizing plate, the reflection of external light can be prevented and the visibility of the screen can be improved.

With the rise of the organic EL display device, as the demand for thinning of the image display device becomes stronger, the thickness of the circular polarizing plate is required. From the retardation film which shape | molded the conventional resin film, changing into the retardation film formed from the liquid crystal compound which can be thinned as a material is examined (for example, refer patent document 1). The retardation film using a polymerizable liquid crystal compound is manufactured by coating and aligning a polymeric liquid crystal compound on a base material, performing light irradiation as needed, and fixing an orientation state. When the circularly polarizing plate having the retardation film formed of the polymerizable liquid crystal compound was placed under a high temperature environment, there was a problem that the color of the circularly polarizing plate was changed from the initial state to blue or red. Specifically, when the circular polarizing plate was rectangular, the color of the reflected light near the four short sides of the circular polarizing plate may change blue or red, respectively.

Patent Document 1: Japanese Patent Application Laid-Open No. 2017-54093

An object of the present invention is to solve the above problems. An object of the present invention is to provide a circularly polarizing plate having a retardation film, the circularly polarizing plate having a small change in color of reflected light before and after being placed in a high temperature environment.

[1] a circularly polarizing plate having a polarizing plate and a retardation film,

The retardation film includes a retardation layer,

The retardation film has a modulus of elasticity of 15 gf / mm or more,

Said elasticity modulus of the circular polarizing plate whose elasticity modulus is measured by the test which has a piercing velocity of 0.33 cm / sec using the needle whose tip diameter is 1 mm (phi) and 0.5R.

[2] The circular polarizing plate has an adhesive layer on the surface thereof,

The polarizing plate has a polarizer,

The retardation layer includes a layer cured by a polymerizable liquid crystal compound,

The retardation film is a circularly polarizing plate according to [1], which is disposed between the polarizing plate and the pressure-sensitive adhesive layer.

[3] The circular polarizer according to [2], wherein the polarizer is formed of a layer cured by a liquid crystal compound.

[4] The circular polarizing plate has a substantially rectangular shape.

In the said polarizing plate, the protective film is laminated | stacked on the surface on the opposite side to the phase difference film side of the said polarizer,

The protective film is a stretched film,

The circularly polarizing plate as described in [2] or [3] whose extending direction of the said protective film and the short side direction of a circularly polarizing plate are substantially parallel.

[5] The circularly polarizing plate according to any one of [1] to [4], wherein the retardation film includes two retardation layers.

[6] A circular polarizing plate with a front plate, in which the circularly polarizing plate and the front plate according to [1] to [5] are laminated via an adhesive layer.

[7] A display device in which the circularly polarizing plate according to any one of [2] to [4] is laminated on a display element via the pressure sensitive adhesive layer.

ADVANTAGE OF THE INVENTION According to this invention, as a circularly polarizing plate provided with retardation film, the circularly polarizing plate with little change of the color of reflected light before and after placing in high temperature environment can be provided.

1 is an example of schematic sectional drawing which shows the laminated constitution of a circularly polarizing plate.
2 is an example of schematic sectional drawing which shows the layer structure of an organic electroluminescence display.
3 is a top view of a sample for evaluation.

Circular Polarizer

The circularly polarizing plate of the present invention includes a polarizing plate and a retardation film. A polarizing plate and retardation film can be laminated | stacked through an adhesive layer, for example. As an adhesive layer, the adhesive layer and adhesive bond layer mentioned later are mentioned, for example. In this invention, a polarizing plate means what is a laminated body which consists of a polarizer and the protective film bonded to one side or both sides of a polarizer.

Hereinafter, with reference to FIG. 1, an example of the laminated constitution of the circularly polarizing plate of this invention is demonstrated. 1, the adhesive bond layer for bonding the polarizer 10 and the protective films 11 and 12, respectively, is not shown. In the circular polarizing plate 100 shown in FIG. 1A, the first protective film 11 is laminated on one surface of the polarizer 10, and the second protective film 12 is disposed on the other surface of the polarizer 10. ) And the retardation film 2 containing the layer 20 which the polymerizable liquid crystal compound hardened | cured, and the polarizing plate 1 laminated | stacked have the laminated constitution laminated | stacked through the adhesive layer 13. Moreover, the circular polarizing plate 100 has the adhesive layer 14 in the surface on the opposite side to the polarizing plate 1 side in the retardation film 2. The pressure-sensitive adhesive layer 14 may be a pressure-sensitive adhesive layer for bonding with an organic EL display element or the like.

In the circular polarizing plate 101 shown in FIG. 1B, the first protective film 11 is laminated on one surface of the polarizer 10, and the second protective film 12 is disposed on the other surface of the polarizer 10. The laminated polarizer 1 and the retardation film 2 have the laminated constitution laminated | stacked through the adhesive layer 13. In the circular polarizing plate 101, the retardation film 2 is a layer structure in which the layer 20 in which the polymerizable liquid crystal compound is cured and the layer 21 in which the polymerizable liquid crystal compound is cured are laminated through the adhesive layer 15. Has In addition, the circular polarizing plate 101 has the adhesive layer 14 in the surface on the opposite side to the polarizing plate 1 side in the retardation film 2. The pressure-sensitive adhesive layer 14 may be a pressure-sensitive adhesive layer for bonding with an organic EL display element or the like.

In the circular polarizing plate 103 shown in FIG. 1C, the polarizing plate 1 having the first protective film 11 laminated on one surface of the polarizer 10, and the retardation film 2, the pressure-sensitive adhesive layer 13 It has a laminated layer structure through). In the circular polarizing plate 103, the polarizing plate 1 is a polarizing plate having a protective film only on one surface of the polarizer 10. In the circular polarizing plate 103, the retardation film 2 is a layer structure in which the layer 20 cured by the polymerizable liquid crystal compound and the layer 21 cured by the polymerizable liquid crystal compound are laminated through the adhesive layer 15. Has In addition, the circular polarizing plate 103 has the adhesive layer 14 in the surface on the opposite side to the polarizing plate 1 in the retardation film 2. The pressure-sensitive adhesive layer 14 may be a pressure-sensitive adhesive layer for bonding with an organic EL display element or the like.

As shown in FIG. 1, the retardation film may have one retardation layer, and may have two layers. In addition, the retardation film may have the orientation film for orientating a polymeric liquid crystal compound in the manufacturing step. As shown in FIG. 1, a protective film may be laminated | stacked only on one surface of a polarizer, and may be laminated | stacked on both surfaces of a polarizing plate.

The circular polarizing plate may have layers other than the layer shown in FIG. 1. As a layer which the circularly polarizing plate may further have, a front plate, a light shielding pattern, etc. are mentioned. The front plate may be arranged on the side opposite to the side on which the retardation film in the polarizing plate is laminated.

The light shielding pattern can be formed on the surface on the polarizing plate side in the front plate. The light shielding pattern is formed in a frame (non-display area) of the image display device, and can prevent the wiring of the image display device from being visually recognized by the user.

The shape of the main surface of the circular polarizing plate may be substantially rectangular. The main surface means the surface having the largest area corresponding to the display surface. Substantially a rectangle is a shape in which at least one of the four corners (angular parts) is cut off to give an obtuse angle or a rounded shape, or a part of a cross section perpendicular to the main surface has recesses (notches) recessed in the in-plane direction, A part in the main surface may have a hole cut out in the shape of a circle, an ellipse, a polygon, or a combination thereof.

The size of the circular polarizing plate is not particularly limited. When the circularly polarizing plate is substantially rectangular, the length of the long side is preferably 6 cm or more and 35 cm or less, more preferably 10 cm or more and 30 cm or less, and the length of the short side is preferably 5 cm or more and 30 cm or less, and 6 cm. It is more preferable that it is more than 25 cm.

<Polarizing plate>

In this invention, a polarizing plate means what is a laminated body which consists of a polarizer and the protective film bonded to one side or both sides of a polarizer. The protective film with which a polarizing plate is equipped may have surface treatment layers, such as a hard coat layer mentioned later, an antireflection layer, an antistatic layer, and the like. A polarizer and a protective film can be laminated | stacked through an adhesive bond layer or an adhesive layer, for example. The member with which a polarizing plate is equipped is demonstrated below.

(1) polarizer

The polarizer of the polarizing plate is an absorption type polarizer having the property of absorbing linear polarized light having a vibration plane parallel to the absorption axis and transmitting linearly polarized light having a vibration plane perpendicular to the absorption axis (parallel to the transmission axis). Can be. As a polarizer which a 1st layer has, the polarizer which adsorbed and oriented a dichroic dye to the uniaxially stretched polyvinyl alcohol-type resin film can be used suitably. The polarizer is, for example, a step of uniaxially stretching a polyvinyl alcohol-based resin film; Adsorbing a dichroic dye by dyeing a polyvinyl alcohol-based resin film with a dichroic dye; Treating a polyvinyl alcohol-based resin film adsorbed with a dichroic dye with a crosslinking solution such as an aqueous boric acid solution; And it can manufacture by the method containing the process of washing with water after the process by a crosslinking liquid.

As polyvinyl alcohol-type resin, what saponified polyvinyl acetate type resin can be used. Examples of the polyvinyl acetate-based resins include copolymers with other monomers copolymerizable with vinyl acetate, in addition to polyvinyl acetate, which is a homopolymer of vinyl acetate. Examples of the other monomer copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, (meth) acrylamides having an ammonium group, and the like.

In the present specification, "(meth) acryl" means at least one selected from acryl and methacryl. The same applies to "(meth) acryloyl", "(meth) acrylate" and the like.

Saponification degree of polyvinyl alcohol-type resin is 85-100 mol% normally, and 98 mol% or more is preferable. The polyvinyl alcohol-based resin may be modified, for example, polyvinyl formal or polyvinyl acetal modified with aldehydes may be used. The average polymerization degree of polyvinyl alcohol-type resin is 1000-10000 normally, and 1500-5000 are preferable. The average degree of polymerization of polyvinyl alcohol-based resin can be obtained in accordance with JIS K 6726.

What formed such a polyvinyl alcohol-type resin into a film is used as a raw film of a polarizer. The method of forming a polyvinyl alcohol-type resin into a film is not specifically limited, A well-known method is employ | adopted. Although the thickness of a polyvinyl alcohol-type master film is not restrict | limited, It is preferable to use what is 5-35 micrometers in order to make thickness of a polarizer 15 micrometers or less. More preferably, it is 20 micrometers or less.

Uniaxial stretching of a polyvinyl alcohol-type resin film can be performed before dyeing, simultaneously with dyeing, or after dyeing of a dichroic dye. When uniaxial stretching is performed after dyeing, this uniaxial stretching may be performed before or during the crosslinking treatment. In addition, you may uniaxially stretch in several of these steps.

In uniaxial stretching, you may extend | stretch uniaxially between the rolls from which a circumferential speed differs, and you may extend | stretch uniaxially using a thermal roll. Moreover, uniaxial stretching may be dry stretching which extends | stretches in air | atmosphere, and wet extending | stretching may be performed in the state which swelled the polyvinyl alcohol-type resin film using a solvent and water. The draw ratio is usually 3 to 8 times.

As a method of dyeing a polyvinyl alcohol-type resin film with a dichroic dye, the method of immersing this film in the aqueous solution containing a dichroic dye is employ | adopted, for example. As a dichroic dye, iodine and a dichroic organic dye are used. Moreover, it is preferable to perform the immersion process with water before a polyvinyl alcohol-type resin film.

As a crosslinking process after dyeing with a dichroic dye, the method of immersing the dyed polyvinyl alcohol-type resin film in boric acid containing aqueous solution is employ | adopted normally. When using iodine as a dichroic dye, it is preferable that this boric acid containing aqueous solution contains potassium iodide.

The thickness of a polarizer is 30 micrometers or less normally, Preferably it is 15 micrometers or less, More preferably, it is 13 micrometers or less, More preferably, it is 10 micrometers or less, Especially preferably, it is 8 micrometers or less. The thickness of a polarizer is 2 micrometers or more normally, and it is preferable that it is 3 micrometers or more. By examination of the present inventors, it turned out that the change of the color of a circularly polarizing plate is caused by the change of the phase difference value of a retardation film. In addition, it became clear that the change of the retardation value of the retardation film is caused by the stress when the polarizing plate shrinks in the circularly polarizing plate placed under a high temperature environment. Therefore, from the viewpoint of reducing the effect of shrinkage of the polarizer, it is effective to prevent the change of color from making the thickness of the polarizer 15 µm or less.

As a polarizer, as described, for example, in Unexamined-Japanese-Patent No. 2016-170368, you may form from the layer which the liquid crystal compound hardened | cured, and the thing which the dichroic dye was orientated specifically in the cured film which the liquid crystal compound superposed | polymerized is used. Also good. As a dichroic dye, what has absorption in the range of wavelength 380-800 nm can be used. As a dichroic dye, it is preferable to use an organic dye. As a dichroic dye, an azo compound is mentioned, for example. A liquid crystal compound is a liquid crystal compound which can superpose | polymerize with orientation, and can have a polymeric group in a molecule | numerator. This type of polarizer can fix a liquid crystal compound and a dichroic dye by apply | coating the composition containing a liquid crystal compound and a dichroic dye on an oriented film, and irradiating an ultraviolet-ray or heating as needed. In addition, as described in WO2011 / 024891 and Japanese Patent Laid-Open No. 2018-120229, you may form a polarizer with the dichroic dye which has liquid crystallinity. Thus, forming a polarizer from the layer which hardened | cured the liquid crystal compound can contribute to making small the dimensional change of a polarizer in a high temperature environment, and is effective in preventing a change of color.

When employ | adopting the polarizer containing the hardened | cured layer as a polarizer, the thickness of a polarizer can be 500 nm or more, and can be 3 micrometers or less.

(2) protective film

It is preferable that the circularly polarizing plate of this invention has a protective film in at least one surface of a polarizer, and it is preferable to have a protective film in the surface on the opposite side to the retardation film side in a polarizer. When a circular polarizing plate is substantially rectangular and a protective film is a stretched film, it is preferable that the extending direction of a protective film and the short side direction of a circular polarizing plate are substantially parallel. When the circular polarizing plate is substantially rectangular, and the protective film is an unstretched film, it is preferable that the direction in which the tensile modulus is largest and the short side direction of the circular polarizing plate are substantially parallel in the plane of the protective film. If the stretching direction (or the direction in which the tensile modulus is largest) and the short side direction are in such a relationship, the color change of the circularly polarizing plate tends to be small regardless of the direction of the slow axis of the retardation film. When the stretching direction of the protective film (or the direction in which the tensile modulus is largest) is parallel to the short side, compared with the case where the shrinkage force in the stretching direction of the protective film due to the relaxation of stretching of the polarizer and the protective film under a high temperature environment is parallel to the long side. It becomes small and it is thought that color change becomes small. In addition, the tensile elasticity modulus is the value at 80 degreeC of tensile elasticity modulus, For example, it measures by Autograph (trademark) (made by Shimadzu Corporation, model number: AG-IS).

The fact that the extending direction of a protective film and the short side direction of a circularly polarizing plate are substantially parallel includes not only the case where both are strictly parallel, but also the case where the angle which both make is 0 +/- 10 degrees. The angle formed by the stretching direction of the protective film and the short side direction of the circular polarizing plate is preferably 0 ± 5 °. In addition to the film which is not extended | stretched, an unstretched film also includes the substantially unstretched film whose draw ratio is 1.1 times or less.

The protective film laminated | stacked on both surfaces of a polarizer is transparent (preferably optically transparent) thermoplastic resin, for example, linear polyolefin resin (polypropylene resin etc.), cyclic polyolefin resin (norbornene resin etc.), and the like. The same polyolefin resin; Cellulose resins such as triacetyl cellulose and diacetyl cellulose; Polyester resins such as polyethylene terephthalate and polybutylene terephthalate; Polycarbonate resins; (Meth) acrylic resins such as methyl methacrylate resin; Polystyrene resin; Polyvinyl chloride resins; Acrylonitrile butadiene styrene resin; Acrylonitrile-styrene resins; Polyvinyl acetate type resin; Polyvinylidene chloride-based resins; Polyamide-based resins; Polyacetal resins; Modified polyphenylene ether resins; Polysulfone resins; Polyether sulfone resin; Polyarylate resins; Polyamideimide resin; It may be a film made of polyimide resin or the like.

Examples of the linear polyolefin-based resin include polyethylene resin (polyethylene resin which is a homopolymer of ethylene and copolymer mainly composed of ethylene), polypropylene resin (polypropylene resin which is a homopolymer of propylene and copolymer mainly composed of propylene) and In addition to the homopolymer of the same linear olefin, the copolymer which consists of 2 or more types of linear olefins is mentioned.

Cyclic polyolefin resin is a general term for resin superposed | polymerized using a cyclic olefin as a polymerization unit, For example, Unexamined-Japanese-Patent No. 1-240517, Unexamined-Japanese-Patent No. 3-14882, and Unexamined-Japanese-Patent No. 3-122137. The resin described in the publication etc. can be mentioned. Specific examples of cyclic polyolefin resins include ring-opening (co) polymers of cyclic olefins, addition polymers of cyclic olefins, copolymers of cyclic olefins with chain olefins such as ethylene and propylene (typically random copolymers) and these Graft polymers modified with unsaturated carboxylic acids and derivatives thereof, and hydrides thereof. Especially, norbornene-type resin using norbornene-type monomers, such as a norbornene and a polycyclic norbornene-type monomer, is used suitably as cyclic olefin.

Polyester-based resin is resin which has an ester bond except the following cellulose ester-type resin, and what consists of polycondensates of polyhydric carboxylic acid or its derivative (s), and a polyhydric alcohol is common. As polyhydric carboxylic acid or its derivative (s), divalent dicarboxylic acid or its derivative (s) can be used, for example, terephthalic acid, isophthalic acid, dimethyl terephthalate and dimethyl naphthalenedicarboxylic acid. Divalent diol can be used as a polyhydric alcohol, For example, ethylene glycol, a propanediol, butanediol, neopentyl glycol, cyclohexane dimethanol is mentioned. As a representative example of polyester resin, the polyethylene terephthalate which is a polycondensate of terephthalic acid and ethylene glycol is mentioned.

(Meth) acrylic-type resin is resin which makes the compound which has a (meth) acryloyl group the main structural monomer. Specific examples of the (meth) acrylic resin include, for example, poly (meth) acrylic acid esters such as polymethyl methacrylate; Methyl methacrylate- (meth) acrylic acid copolymer; Methyl methacrylate- (meth) acrylic acid ester copolymer; Methyl methacrylate-acrylic acid ester- (meth) acrylic acid copolymer; Methyl (meth) acrylate-styrene copolymers (MS resin and the like); Copolymers of methyl methacrylate with a compound having an alicyclic hydrocarbon group (for example, methyl methacrylate-cyclohexyl copolymer, methyl methacrylate-norbornyl acrylate) and the like. Preferably, the poly (meth) poly (meth) acrylate polymer as a main component acrylic acid C _{1- 6} alkyl ester is used, more preferably, the main component methyl methacrylate (50 to 100% by weight, such as methyl acrylate, Preferably, the methyl methacrylate type resin made into 70 to 100 weight%) is used.

Cellulose ester-type resin is ester of a cellulose and a fatty acid. Specific examples of the cellulose ester-based resin include cellulose triacetate, cellulose diacetate, cellulose tripropionate, and cellulose dipropionate. Moreover, these copolymers and the thing in which one part of hydroxyl group was modified by another substituent are mentioned. Among these, cellulose triacetate (triacetyl cellulose) is particularly preferable.

Polycarbonate resin is an engineering plastic which consists of a polymer in which the monomeric unit couple | bonded through the carbonate group.

It is also useful to control the phase difference value of a protective film to the value suitable for image display apparatuses, such as a liquid crystal display device. For example, in the liquid crystal display device of in-plane switching (IPS) mode, it is preferable to use the film whose phase difference value is substantially zero as a protective film. Substantially zero phase difference means that the in-plane phase difference value Re (550) in wavelength 550nm is 10 nm or less, and the absolute value of the thickness direction phase difference value Rth in wavelength 550nm is 10 nm or less. It is preferable that the absolute value of the thickness direction retardation value Rth in wavelength 480-750 nm is 15 nm or less. In addition, in order to improve the visibility of the screen when the user wears polarized sunglasses or the like, the in-plane retardation value Re (550) at a wavelength of 550 nm may be set to 70 to 140 nm.

For example, depending on the mode of a liquid crystal display device, you may extend | stretch and / or shrink process etc. to a protective film, and may provide a suitable phase difference. For example, for the purpose of viewing angle compensation, a single layer or a multilayer structure may be used as the protective film.

Although the thickness of a protective film is 1-100 micrometers normally, it is preferable that it is 5-60 micrometers from a viewpoint of strength, handleability, etc., It is more preferable that it is 10-55 micrometers, It is further more preferable that it is 15-40 micrometers.

The protective film bonded to one side or both sides of a polarizer may be comprised with the same kind of thermoplastic resin, and may be comprised with the heterogeneous thermoplastic resin. Moreover, thickness may be the same and may differ. Moreover, it may have the same phase difference characteristic, and may have a different phase difference characteristic.

As described above, at least one of the protective film has a hard coat layer, an antiglare layer, a light diffusion layer, an antireflection layer, a low refractive index layer, an antistatic layer, or an antifouling layer on its outer surface (surface opposite to the polarizer side). The same surface treatment layer (coating layer) may be provided. In addition, the thickness of a protective film includes the thickness of a surface treatment layer.

A protective film can be bonded to a polarizer through an adhesive bond layer or an adhesive layer, for example. As an adhesive agent which forms an adhesive bond layer, an aqueous adhesive agent, an active energy ray curable adhesive agent, or a thermosetting adhesive agent can be used, Preferably it is an aqueous adhesive agent or an active energy ray curable adhesive agent. As an adhesive layer, the thing mentioned later can be used.

As an aqueous adhesive agent, the adhesive agent which consists of polyvinyl alcohol-type resin aqueous solution, an aqueous two-component urethane emulsion adhesive, etc. are mentioned. Especially, the aqueous adhesive which consists of aqueous solution of polyvinyl alcohol-type resin is used suitably. As polyvinyl alcohol-type resin, in addition to the vinyl alcohol homopolymer obtained by saponifying polyvinyl acetate which is a homopolymer of vinyl acetate, the polyvinyl alcohol-type air obtained by saponifying the copolymer of vinyl acetate and the other monomer copolymerizable with this. The modified polyvinyl alcohol polymer etc. which partially modified | polymerized or these hydroxyl groups can be used. The aqueous adhesive may include a crosslinking agent such as an aldehyde compound (glyoxal or the like), an epoxy compound, a melamine compound, a methylol compound, an isocyanate compound, an amine compound, a polyvalent metal salt, or the like.

When using an aqueous adhesive agent, after bonding a polarizer and a protective film, it is preferable to perform the drying process for removing the water contained in an aqueous adhesive agent. After a drying process, you may provide the curing process which cures at the temperature of 20-45 degreeC, for example.

The said active energy ray curable adhesive agent is an adhesive agent containing the curable compound hardened | cured by irradiation of active energy rays, such as an ultraviolet-ray, a visible light, an electron beam, or X-rays, Preferably it is an ultraviolet curable adhesive agent.

The curable compound may be a cationic polymerizable curable compound or a radical polymerizable curable compound. As a cationically polymerizable curable compound, For example, an epoxy type compound (compound which has one or two or more epoxy groups in a molecule), an oxetane type compound (compound which has one or two or more oxetane rings in a molecule), or these For example, a combination. As a radically polymerizable curable compound, For example, (meth) acrylic-type compound (compound which has one or two or more (meth) acryloyloxy groups in a molecule), the other vinyl type compound which has a radically polymerizable double bond, or Combinations of these are mentioned. You may use together a cationically polymerizable curable compound and a radically polymerizable curable compound. The active energy ray curable adhesive usually further contains a cationic polymerization initiator and / or a radical polymerization initiator for initiating the curing reaction of the curable compound.

In bonding a polarizer and a protective film, in order to improve adhesiveness, you may surface-activate at least one of these bonding surfaces. As the surface activation treatment, dry treatment such as corona treatment, plasma treatment, discharge treatment (glow discharge treatment, etc.), flame treatment, ozone treatment, UV ozone treatment, and ionizing active line treatment (ultraviolet ray treatment, electron beam treatment, etc.); Examples of the wet treatment include ultrasonic treatment using a solvent such as water or acetone, saponification treatment, and anchor coat treatment. Such surface activation treatment may be performed alone or in combination of two or more thereof.

When the protective film is bonded to both surfaces of the polarizer, the adhesive for bonding such a protective film may be the same kind of adhesive or a different kind of adhesive.

Instead of the protective film, a protective layer may be formed on at least one surface of the polarizer. The protective layer can be formed as a polarizer without passing through the adhesive layer or the pressure-sensitive adhesive layer. That is, the protective layer may be formed in contact with the polarizer. The protective layer may be a layer containing a (meth) acrylic resin or a layer containing an aqueous resin.

The layer containing (meth) acrylic resin coats a composition containing (meth) acrylic resin on a polarizer to irradiate heating or active energy rays or to coat a composition containing (meth) acrylic resin on a base film. By heating or irradiating an active energy ray. In the latter case, you may form a polarizer on the layer containing (meth) acrylic-type resin.

(Meth) acrylic-type resin means that the monomer which has a (meth) acryloyl group in the monomer which comprises (meth) acrylic-type resin is a polymer which is a main component. Here, a main component means the monomer with the largest content (mass%) among the monomer components which comprise (meth) acrylic-type resin. By using (meth) acrylic-type resin as a material which forms a protective layer, it can also suppress that the optical characteristic of a circularly polarizing plate falls even in a wet heat environment.

As (meth) acrylic-type resin, what superposed | polymerized the photopolymerizable monomer is preferable, for example, the monofunctional monomer or polyfunctional monomer which has a (meth) acryloyl group may be what superposed | polymerized individually or in mixture of 2 or more types. In (meth) acrylic-type resin, monomers other than the monomer which has a (meth) acryloyl group may superpose | polymerize, for example, the monomer which has a vinyl group may superpose | polymerize.

Although it does not specifically limit as a monomer which has a (meth) acryloyl group, The compound which has one or two or more (meth) acryloyl groups in a molecule | numerator can be mentioned, These are used individually or in mixture of 2 or more types Can be. Specifically, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, and the (meth) acrylate Ethylene oxide or propylene oxide addition compound; Oligoester (meth) acrylate, oligoether (meth) acrylate, oligourethane (meth) acrylate, oligoepoxy (meth) acrylate, oligomelamine (meth) having four or more (meth) acryloyl groups in the molecule Acrylate, a polyfunctional acrylate which has a dendrimer structure, etc. are mentioned.

The thickness of the layer containing (meth) acrylic resin is usually 0.1 µm or more, preferably 0.3 µm or more, more preferably 0.5 µm or more, and usually 20.0 µm or less, preferably 15 µm or less, 10 It is more preferable that it is micrometer or less. When the thickness of the layer containing (meth) acrylic resin is in the above range, the bendable circularly polarizing plate can be easily obtained.

The layer containing the water-based resin coats the composition containing the water-based resin on the polarizer, irradiates heating or active energy rays, or coats the composition containing the (meth) acrylic resin on the base film, and heats or activates the energy. It can form by irradiating a line. In the latter case, you may form a polarizer on the layer containing aqueous resin.

Examples of the water-based resin include water-soluble polymers such as polyvinyl alcohol, ethylene vinyl acetate copolymer, polyvinylpyrrolidone, starch, methyl cellulose, carboxymethyl cellulose, sodium alginate, and the like, of which polyvinyl alcohol is preferable. Do.

It is preferable that the thickness of the layer containing aqueous resin is 0.1 micrometer or more, It is more preferable that it is 0.3 micrometer or more, Furthermore, it is preferable that it is 3 micrometers or less, It is more preferable that it is 1.5 micrometers or less, It is further more preferable that it is 1 micrometer or less. When the thickness of the layer containing the aqueous resin is in the above range, the bendable circularly polarizing plate is easily obtained.

The protective layer may be a single layer or may be formed of a plurality of layers. As an aspect in which a protective layer is formed from several layers, the aspect in which a protective layer is comprised by the laminated body of the layer containing (meth) acrylic-type resin and the layer containing aqueous resin is mentioned.

<Phase difference film>

The circularly polarizing plate of the present invention has a retardation film. The projection elastic modulus of the retardation film is 15 gf / mm or more, preferably 20 gf / mm or more, more preferably 25 gf / mm or more, and even more preferably 30 gf / mm or more. The upper limit of the projection elastic modulus of the retardation film is not particularly limited, and may be, for example, 200 gf / mm or less, or 50 gf / mm or less. The retardation film having the puncture elasticity modulus in such a range tends to hardly cause a change in the retardation value under a high temperature environment. The larger the puncture elasticity modulus, the less the change in the retardation value with respect to the stress caused by the dimensional shrinkage of the polarizing plate.

When the retardation film includes a retardation layer that is one layer, the puncture elastic modulus of the retardation film is 15 gf / mm or more, preferably 20 gf / mm or more, more preferably 25 gf / mm or more, and 30 gf / mm or more More preferred. The upper limit of the projection elastic modulus of the retardation film is not particularly limited, and may be, for example, 200 gf / mm or less, 90 gf / mm or less, or 50 gf / mm or less.

In the case where the retardation film includes two phase retardation layers, the resilient modulus of the retardation film is preferably 30 gf / mm or more, more preferably 40 gf / mm or more, still more preferably 50 gf / mm or more, and 70 gf It is especially preferable that it is / mm or more. The upper limit of the projection elastic modulus of the retardation film is not particularly limited, and may be, for example, 200 gf / mm or less, 150 gf / mm or less, or 100 gf / mm or less.

The puncture elasticity modulus is a value obtained by dividing the force (gf) just before the retardation film breaks (or tears) when the needle (the rotor jig) is turned perpendicular to the main surface of the retardation film, divided by the deformation (mm) at that time. Say. As the needle, one having a tip diameter of 1 mmφ and 0.5 R can be used. The speed of turning the needle can be 0.33 cm / sec. The measurement of the puncture elasticity modulus is performed by interposing a retardation film between two plates having a circular hole of 15 mm or less in diameter through which a needle can pass. The measurement of the puncture elasticity modulus can be performed in an environment of a temperature of 23 ° C. For example, the puncture elasticity modulus is measured about five retardation films, and the average value can be made into the puncture elasticity modulus of a retardation film. A commercially available apparatus can be used for the measurement of the puncture elasticity modulus. As a commercially available apparatus, the Katotech Co., Ltd. handy compression tester "KES-G5 needle penetrating force measurement specification", the compact bench tester "EZ Test" by Shimadzu Corporation make, etc. are mentioned.

The projection elastic modulus of the retardation film can be controlled by adjusting, for example, the kind of the polymerizable liquid crystal compound or alignment film to be used, the degree of curing of the polymerizable liquid crystal compound, the thickness of the retardation film, or the like.

The retardation film has a retardation layer. It is preferable that a retardation layer has a layer comprised from the composition containing a polymeric liquid crystal compound. The layer comprised from the composition containing a polymeric liquid crystal compound means the layer which the polymeric liquid crystal compound hardened specifically ,. In this specification, the layer which gives retardation of (lambda) / 2, the layer (positive A layer), positive C layer, etc. which give a phase difference of (lambda) / 4 may be named generically, and may be called retardation layer. In addition, the retardation film may contain the orientation film mentioned later.

As a layer which gives the phase difference of (lambda) / 2, it means that it is a layer whose in-plane phase difference value at wavelength 550nm is 200-280 nm preferably, More preferably, it means that it is a layer whose in-plane phase difference value is 215-265 nm. . As a layer which gives the phase difference of (lambda) / 4, it means that it is a layer whose in-plane phase difference value in wavelength 550nm is 100-160 nm preferably, More preferably, it means that it is a layer whose in-plane phase difference value is 110-150 nm. . The positive C layer may be a layer showing a relationship in which the refractive index is nx ≒ ny <nz. The retardation value in the thickness direction of the positive C layer may be -50 nm to -150 nm and -70 nm to -120 nm at a wavelength of 550 nm.

The layer which the polymeric liquid crystal compound hardened | cured is formed, for example on the oriented film provided in the base material. The base material may have a function of supporting the alignment film and may be formed to be elongated. This substrate can function as a support having releasability and can support the phase difference layer to be transferred. Moreover, it is preferable that the surface has adhesive force of the grade which can peel. As said base material, the resin film exemplified as a material of the said protective film is mentioned.

Although it does not specifically limit as thickness of a base material, It is preferable to set it as the range of 20 micrometers or more and 200 micrometers or less, for example. If the thickness of the substrate is 20 µm or more, the strength is imparted. On the other hand, when thickness is 200 micrometers or less, when a base material is cut and it is set as a base material of a single leaf, increase of processing waste and abrasion of a cutting edge can be suppressed.

Moreover, the base material may be subjected to various blocking prevention processes. As a blocking prevention process, the process of tack | tacking an easily bonding process, a filler, etc., embossing (knurling process), etc. are mentioned, for example. By performing such a blocking prevention process with respect to a base material, the sticking of the base materials when a base material is wound up, what is called blocking can be prevented effectively, and it becomes possible to manufacture an optical film with high productivity.

The layer which the polymeric liquid crystal compound hardened is formed on a base material through an orientation film. That is, the layer laminated | stacked in order of a base material and an oriented film, and the layer which hardened the polymeric liquid crystal compound is laminated | stacked on the said oriented film.

The alignment film is not limited to the vertical alignment film, and may be an alignment film for horizontally aligning the molecular axis of the polymerizable liquid crystal compound, or may be an alignment film for tilting the molecular axis of the polymerizable liquid crystal compound. As an oriented film, it is preferable to have solvent resistance which does not melt | dissolve by coating etc. of the composition containing the polymeric liquid crystal compound mentioned later, and has heat resistance in heat processing for removal of a solvent and the orientation of a liquid crystal compound. Examples of the alignment film include a groove alignment film in which an uneven pattern or a plurality of grooves are formed and aligned on an alignment film, an optical alignment film, and a surface containing an alignment polymer. The thickness of the alignment film is usually in the range of 10 nm to 10000 nm, preferably in the range of 10 nm to 1000 nm, more preferably 500 nm or less, and still more preferably in the range of 10 nm to 200 nm. When the retardation film has an alignment film, when the thickness of the alignment film is increased, it is easy to increase the puncture elasticity modulus.

Orientation film containing an orientation polymer is obtained by apply | coating the composition which the orientation polymer melt | dissolved in the solvent to a base material and removing a solvent, or apply | coating an orientation polymer composition to a base material, removing a solvent, and rubbing (rubbing method) Lose. Examples of the oriented polymer include polyamides and gelatin having amide bonds in the molecule, polyimides having imide bonds in the molecule, and polyamic acid, polyvinyl alcohol, alkyl modified polyvinyl alcohol, polyacrylamide and poly Oxazole, polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid and polyacrylic acid esters. Especially, polyvinyl alcohol is preferable. An oriented polymer can be used individually or in combination of 2 or more types.

A photo-alignment film is usually obtained by apply | coating the composition containing a polymer or monomer which has a photoreactive group, and a solvent to a base material, and irradiating polarized light (preferably polarized UV) after removing a solvent. The photo-alignment film is also advantageous in that the direction of the orientation regulation force can be arbitrarily controlled by selecting the polarization direction of the polarized light to be irradiated.

A photoreactive group means the group which produces the liquid-crystal orientation ability by light irradiation. Specifically, the group which participates in the photoreaction which originates in liquid crystal aligning ability, such as the orientation organic or isomerization reaction of a molecule | numerator produced by light irradiation, a dimerization reaction, a photocrosslinking reaction, or a photolysis reaction, is mentioned. Especially, the group which participates in a dimerization reaction or a photocrosslinking reaction is preferable at the point which is excellent in orientation. As the photoreactive group, unsaturated bonds, in particular, groups having double bonds are preferable, carbon-carbon double bonds (C = C bonds), carbon-nitrogen double bonds (C = N bonds), nitrogen-nitrogen double bonds (N = N And groups having at least one selected from the group consisting of a bond) and a carbon-oxygen double bond (C═O bond).

As a photoreactive group which has a C = C bond, a vinyl group, a polyene group, a stilbene group, a stilazole group, a stilbazolium, a chalcone group, a cinnamoyl group, etc. are mentioned. As photoreactive group which has a C = N bond, group which has structures, such as an aromatic sheep base and an aromatic hydrazone, is mentioned. As a photoreactive group which has N = N bond, the group which has an azobenzene group, an azonaphthalene group, an aromatic heterocyclic azo group, a bis azo group, a formazan group, and an azoxybenzene structure, etc. are mentioned. As a photoreactive group which has a C = O bond, a benzophenone group, a coumarin group, an anthraquinone group, a maleimide group, etc. are mentioned. Such a group may have substituents, such as an alkyl group, an alkoxy group, an aryl group, an allyloxy group, a cyano group, an alkoxycarbonyl group, a hydroxyl group, a sulfonic acid group, and a halogenated alkyl group.

Especially, the photoreactive group which participates in a photodimerization reaction is preferable, The amount of polarization irradiation required for photo-alignment is comparatively small, and since it is easy to obtain the photo-alignment film excellent in thermal stability and stability with time, Cinnamo is easy to obtain. Diary and chalcone groups are preferred. As a polymer which has a photoreactive group, what has a cinnamoyl group in which the terminal part of this polymer side chain turns into a cinnamic acid structure is especially preferable.

The kind of the polymerizable liquid crystal compound used in the present embodiment is not particularly limited, but can be classified into a rod type (bar type liquid crystal compound) and a disc type (disk type liquid crystal compound, discotic liquid crystal compound) from the shape. Can be. In addition, there are low molecular type and high polymer type, respectively. In addition, a polymer generally means that the degree of polymerization is 100 or more (polymer physics-phase transition dynamics, by Doi Masao, page 2, Iwanami Bookstore, 1992).

In this embodiment, all the polymeric liquid crystal compounds can also be used. Moreover, you may use 2 or more types of rod-shaped liquid crystal compounds, 2 or more types of disk-shaped liquid crystal compounds, or a mixture of a rod-shaped liquid crystal compound and a disk-shaped liquid crystal compound.

As the rod-shaped liquid crystal compound, for example, those described in claims 1 of JP-A-11-513019 or in paragraphs [0026] to [0098] of JP-A-2005-289980 can be suitably used. have. As the discotic liquid crystal compound, for example, those described in paragraphs [0020] to [0067] of JP-A-2007-108732 or paragraphs [0013] to [0108] of JP-A-2010-244038 are suitable. Available.

The polymerizable liquid crystal compound may use two or more types together. In that case, at least 1 type has 2 or more polymerizable groups in a molecule | numerator. That is, it is preferable that the layer which the said polymeric liquid crystal compound hardened | cured is a layer in which the liquid crystal compound which has a polymeric group was fixed by superposition | polymerization and formed. In this case, after forming a layer, it is no longer necessary to show liquid crystallinity.

The polymerizable liquid crystal compound has a polymerizable group capable of carrying out a polymerization reaction. As the polymerizable group, for example, a functional group capable of addition polymerization reaction such as a polymerizable ethylenically unsaturated group or a ring polymerizable group is preferable. More specifically, as a polymerizable group, a (meth) acryloyl group, a vinyl group, a styryl group, an allyl group, etc. are mentioned, for example. Especially, a (meth) acryloyl group is preferable. In addition, a (meth) acryloyl group is a concept containing both a methacryloyl group and an acryloyl group.

The layer which hardened the polymerizable liquid crystal compound can be formed by coating a composition containing the polymerizable liquid crystal compound on, for example, an alignment film and irradiating an active energy ray, as described later. The composition may contain components other than the above-mentioned polymerizable liquid crystal compound. For example, it is preferable that the said composition contains the polymerization initiator. As the polymerization initiator to be used, for example, a thermal polymerization initiator or a photopolymerization initiator is selected according to the type of the polymerization reaction. For example, as a photoinitiator, the (alpha)-carbonyl compound, an acyloin ether, the (alpha) -hydrocarbon substituted aromatic acyloin compound, a polynuclear quinone compound, the combination of a triarylimidazole dimer, and p-aminophenyl ketone, etc. are mentioned. have. It is preferable that it is 0.01-20 mass% with respect to the total solid in the said coating liquid, and, as for the usage-amount of a polymerization initiator, it is more preferable that it is 0.5-5 mass%.

In addition, a polymerizable monomer may be contained in the said composition from the point of the uniformity of a coating film, and the strength of a film | membrane. A radically polymerizable or cationically polymerizable compound is mentioned as a polymerizable monomer. Especially, a polyfunctional radically polymerizable monomer is preferable.

Moreover, as a polymerizable monomer, what can copolymerize with the polymerizable liquid crystal compound mentioned above is preferable. It is preferable that it is 1-50 mass% with respect to the total mass of a polymeric liquid crystal compound, and, as for the usage-amount of a polymeric monomer, it is more preferable that it is 2-30 mass%.

Moreover, surfactant may be contained in the said composition from the point of the uniformity of a coating film, and the strength of a film | membrane. As surfactant, a conventionally well-known compound is mentioned. Especially, especially a fluorine compound is preferable.

In addition, a solvent may be contained in the said composition, and an organic solvent is used preferably. As the organic solvent, for example, an amide (e.g., N, N-dimethylformamide), a sulfoxide (e.g., dimethyl sulfoxide), a heterocyclic compound (e.g., pyridine), a hydrocarbon (e.g., benzene, hexane), an alkyl halide ( Chloroform, dichloromethane), esters (e.g. methyl acetate, ethyl acetate, butyl acetate), ketones (e.g. acetone, methyl ethyl ketone), ethers (e.g. tetrahydrofuran, 1,2-dimethoxyethane) Can be mentioned. Among them, alkyl halides and ketones are preferable. Moreover, you may use together 2 or more types of organic solvents.

Moreover, the said composition contains various orientation agents, such as vertical orientation promoters, such as a polarizer interface side vertical aligning agent and an air interface side vertical aligning agent, and horizontal orientation promoters, such as a polarizer interface side horizontal aligning agent and an air interface side horizontal aligning agent. You may be. In addition to the above components, the composition may contain an adhesion improving agent, a plasticizer, a polymer, and the like.

The said active energy ray contains an ultraviolet-ray, visible light, an electron beam, and X-ray, Preferably it is an ultraviolet-ray. As the light source of the active energy ray, for example, low pressure mercury lamp, medium pressure mercury lamp, high pressure mercury lamp, ultra high pressure mercury lamp, xenon lamp, halogen lamp, carbon arc lamp, tungsten lamp, gallium lamp, excimer laser, wavelength range 380-440 nm LED light sources, chemical lamps, black light lamps, microwave-excited mercury lamps, metal halide lamps and the like that emit light.

Irradiation intensity of an ultraviolet-ray is 100 mW / cm <2> -3,000 mW / cm <2> normally. UV irradiation intensity is preferably the intensity | strength in the wavelength range effective for activation of a cationic polymerization initiator or a radical polymerization initiator. The time to irradiate an ultraviolet-ray is 0.1 second-10 minutes normally, Preferably it is 0.1 second-5 minutes, More preferably, it is 0.1 second-3 minutes, More preferably, it is 0.1 second-1 minute.

Ultraviolet rays can be irradiated once or in a plurality of times. It is preferable that an ultraviolet-ray is irradiated in multiple times. As the polymerization rate of the liquid crystal compound increases, the puncture elasticity tends to increase in the range of the present invention. Although it also depends on the polymerization initiator to be used, the accumulated light amount at a wavelength of 365 nm is preferably 700 mJ / cm 2 or more, more preferably 1,100 mJ / cm 2 or more, and even more preferably 1,300 mJ / cm 2 or more. . The amount of accumulated light is advantageous for increasing the polymerization rate of the polymerizable liquid crystal compound constituting the retardation film and for increasing the puncture elasticity of the retardation film. The accumulated light amount at a wavelength of 365 nm is preferably 2,000 mJ / cm 2 or less, and more preferably 1,800 mJ / cm 2 or less. The amount of accumulated light may cause coloring of the retardation film.

Moreover, in order to prevent the orientation of a liquid crystal compound from being disturbed by the heat | fever immediately after ultraviolet irradiation, it is preferable to provide a cooling process after ultraviolet irradiation. By providing a cooling process after ultraviolet irradiation, the confusion of the orientation of the liquid crystal compound by the heat which generate | occur | produces immediately after irradiation can be suppressed. As a result, the orientation degree of a liquid crystal compound rises and the film which has higher rigidity can be obtained. Cooling temperature can be 20 degrees C or less, for example, and can be 10 degrees C or less. The cooling time can be, for example, 10 seconds or more and 20 seconds or more.

In this embodiment, it is preferable that the thickness of retardation layer is 0.5 micrometer or more. Moreover, it is preferable that it is 10 micrometers or less, and, as for the thickness of the said retardation layer, it is more preferable that it is 5 micrometers or less. In addition, the above-mentioned upper limit and lower limit can be combined arbitrarily. Sufficient durability is obtained as the thickness of a phase difference layer is more than the said lower limit. If the thickness of a phase difference layer is below the said upper limit, it can contribute to the thinning of a circularly polarizing plate. The thickness of the retardation layer can be adjusted so that a desired in-plane retardation value of the layer giving a phase difference of λ / 4, a layer giving a phase difference of λ / 2, or a positive C layer, and a phase difference value in the thickness direction are obtained.

The retardation film may include one layer of the layer cured by the polymerizable liquid crystal compound, or may include two or more layers of the layer cured by the polymerizable liquid crystal compound. When the retardation film contains two layers of the polymerizable liquid crystal compound cured, the two layers are a combination of a layer giving a phase difference of λ / 4 and a positive C layer, or a layer giving a phase difference of λ / 4 and λ. It is preferable that it is a combination of the layer which gives the phase difference of / 2. When the retardation film includes two layers of the layer cured by the polymerizable liquid crystal compound, the retardation film is prepared by producing a layer on which the polymerizable liquid crystal compound is cured on the alignment film, respectively, and laminating both of them through the adhesive layer or the pressure-sensitive adhesive layer. You may manufacture, and on the layer which the polymeric liquid crystal compound hardened, you may form the layer which the polymeric liquid crystal compound hardened again. After laminating both, the substrate and the alignment film can be peeled off. It is preferable that it is 3-30 micrometers, and, as for the thickness of retardation film, it is more preferable that it is 5-25 micrometers.

<Adhesive layer>

An adhesive layer can be comprised by the adhesive composition which has resin, such as (meth) acrylic-type, rubber type, urethane type, ester type, silicone type, and polyvinyl ether type as a main component. Especially, the adhesive composition which uses (meth) acrylic-type resin which is excellent in transparency, weather resistance, heat resistance, etc. as a base polymer is suitable. The pressure-sensitive adhesive composition may be an active energy ray curing type or a thermosetting type. The thickness of an adhesive layer is 3-30 micrometers normally, Preferably it is 3-25 micrometers.

Examples of the (meth) acrylic resin (base polymer) used in the pressure-sensitive adhesive composition include (meth) such as butyl (meth) acrylate, ethyl (meth) acrylate, isooctyl (meth) acrylate and 2-ethylhexyl (meth) acrylate. The polymer or copolymer which uses 1 type, or 2 or more types of acrylate ester as a monomer is used suitably. It is preferable to copolymerize a polar monomer to a base polymer. Examples of the polar monomers include (meth) acrylic acid, (meth) acrylic acid 2-hydroxypropyl, (meth) acrylate hydroxyethyl, (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylate, glycy The monomer which has a carboxyl group, a hydroxyl group, an amide group, an amino group, an epoxy group, etc. like a dill (meth) acrylate is mentioned.

Although the adhesive composition may include only the said base polymer, it usually contains a crosslinking agent further. As a crosslinking agent, it is a divalent or more metal ion which forms a carboxylic acid metal salt between carboxyl groups; As a polyamine compound, forming an amide bond between carboxyl groups; As a polyepoxy compound or polyol, forming an ester bond between carboxyl groups; As a polyisocyanate compound, forming an amide bond between carboxyl groups is illustrated. Especially, a polyisocyanate compound is preferable.

<Front plate>

The present invention includes a circularly polarizing plate with a front plate in which the circularly polarizing plate and the front plate are laminated through an adhesive layer. The front plate is disposed on the viewing side of the polarizing plate. The front plate may be laminated to the polarizing plate through an adhesive layer. As an adhesive layer, the above-mentioned adhesive layer and an adhesive bond layer are mentioned, for example. As shown to Fig.2 (a), (b), (c), the front plate 4 can be laminated | stacked through the adhesive layer 16 on the protective film 11 in the polarizing plate 1. have.

As a front plate, what consists of a hard coat layer in at least one surface of glass and a resin film, etc. are mentioned. As glass, high permeation glass and tempered glass can be used, for example. When using a thin transparent face material especially, the glass which gave chemical strengthening is preferable. The thickness of glass can be 100 micrometers-5 mm, for example.

The front plate including the hard coat layer on at least one surface of the resin film may have flexible characteristics, not rigid, as in conventional glass. The thickness of the hard coat layer is not particularly limited, and may be, for example, 5 to 100 µm.

As the resin film, a cycloolefin derivative having a unit of a monomer containing a cycloolefin such as a norbornene or a polycyclic norbornene monomer, cellulose (diacetyl cellulose, triacetyl cellulose, acetyl cellulose butyrate, isobutyl ester cellulose, propionyl cellulose , Butyryl cellulose, acetylpropionyl cellulose) ethylene-vinyl acetate copolymer, polycycloolefin, polyester, polystyrene, polyamide, polyetherimide, polyacryl, polyimide, polyamideimide, polyether sulfone, polysulfone, Polyethylene, polypropylene, polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl acetal, polyether ketone, polyether ether ketone, polyether sulfone, polymethyl methacrylate, polyethylene terephthalate, poly Ethylene terephthalate, film may be formed from any polymer, such as polyethylene naphthalate, polycarbonate, polyurethane, epoxy. An unstretched, uniaxial or biaxially oriented film can be used for the resin film. These polymers can be used individually or in mixture of 2 or more types, respectively. As the resin film, a polyamideimide film or a polyimide film excellent in transparency and heat resistance, a monoaxial or biaxially stretched polyester film, excellent in transparency and heat resistance, and a cycloolefin derivative film and poly that can cope with the enlargement of the film Preferred are methyl methacrylate films and triacetyl cellulose and isobutyl ester cellulose films without transparency and optically anisotropy. The thickness of the resin film is 5 to 200 m, preferably 20 to 100 m.

The hard coat layer may be formed by curing a hard coat composition containing a reactive material that forms a crosslinked structure by irradiating light or thermal energy. The hard coat layer can be formed by curing a hard coat composition containing a photocurable (meth) acrylate monomer or an oligomer, a photocurable epoxy monomer or an oligomer simultaneously. The photocurable (meth) acrylate monomer may include one or more selected from the group consisting of epoxy (meth) acrylate, urethane (meth) acrylate, and polyester (meth) acrylate. The said epoxy (meth) acrylate can be obtained by making the carboxylic acid which has a (meth) acryloyl group react with an epoxy compound.

The hard coat composition may further include one or more selected from the group consisting of solvents, photoinitiators and additives. The additive may include one or more selected from the group consisting of inorganic nanoparticles, leveling agents and stabilizers, and in addition to each of the components generally used in the art, for example, antioxidants, UV absorbers, surfactants, Lubricants, antifouling agents and the like.

<Shading Pattern>

The light shielding pattern may be provided as at least a portion of the bezel or the housing of the display device to which the front plate or the front plate is applied. The light shielding pattern can be formed on the display element side in the front panel. The light shielding pattern can hide each wiring of the display device so that it is not visible to a user. The color and / or material of the light shielding pattern is not particularly limited, and may be formed of a resin material having various colors such as black, white, and gold. In one embodiment, the thickness of the light shielding pattern may be 2 µm to 50 µm, preferably 4 µm to 30 µm, and more preferably 6 µm to 15 µm. Moreover, in order to suppress bubble mixing by the step | step between the light shielding pattern and a display part, and visibility of a boundary part, a shape can be given to a light shielding pattern.

<Method for Manufacturing Circular Polarizing Plate>

The manufacturing method of a circular polarizing plate is demonstrated by taking the circular polarizing plate 100 shown to FIG. 1 (a) as an example. The circular polarizing plate 100 can be manufactured by laminating the polarizing plate 1 and the retardation film 2 via the pressure-sensitive adhesive layer 13.

The polarizing plate 1 can manufacture the polarizer 10 and the protective films 11 and 12 laminated | stacked through an adhesive bond layer, respectively. After preparing a elongate member, bonding each member with a roll-to-roll, you may cut and manufacture a predetermined shape, and you may join, after cutting each member to a predetermined shape. After bonding the protective films 11 and 12 to the polarizer 10, you may provide a heating process and a humidity control process.

The retardation film 2 can be manufactured as follows, for example. An alignment film is formed on a base material, and the coating liquid containing a polymeric liquid crystal compound is coated on an alignment film. Active energy rays are irradiated in the state which orientated the polymerizable liquid crystal compound to cure the polymerizable liquid crystal compound. The adhesive layer 14 formed on the peeling film is laminated | stacked on the layer which the polymeric liquid crystal compound hardened | cured. Subsequently, the substrate and / or the alignment film are peeled off. Subsequently, the pressure-sensitive adhesive layer 13 formed on the release film is laminated on the protective film 12. The retardation film 2 may prepare a long member, bond each member with a roll-to-roll, cut it into a predetermined shape and manufacture it, or cut each member into a predetermined shape and then join it. good.

And the circularly-polarizing plate 100 can be manufactured by peeling the peeling film laminated | stacked on the adhesive layer 13, and bonding the retardation film 2 and the polarizing plate 1 through the adhesive layer 13.

The difference of the color visually recognized in the plane of the circularly polarizing plate on the reflecting plate after the heat resistance test can be reduced by uniformizing the reflection color in the plane of the circularly polarizing plate after the heat resistance test. As a necessary element in order to uniformize the reflection color in the plane of the circularly polarizing plate after the heat resistance test, the reflection color in the plane of the circularly polarizing plate before the heat test is uniform, and the change in the reflection color before and after the heat test is small.

It is preferable that the color of the reflected light before the heat resistance test of the circular polarizing plate is uniform in plane in order to reduce the color difference of the reflected light in the surface of the circular polarizing plate surface after the heat resistance test. Specifically, the color of the reflected light in the center in the main surface (may be the center of weight, or the point 5 in the center shown in FIG. 3) before the heat resistance test, and the part other than the center in the main surface (for example, other than the center shown in FIG. 3). It is preferable that the magnitude | size of the difference with the color of the reflected light in point 5) may be 1.0 or less, It is more preferable that it is 0.8 or less, It is further more preferable that it is 0.6 or less. The color difference of the reflected light between a center part and another part can be computed from the following formula | equation, for example.

Δa * b * = [(Δa *) ² + (Δb *) ² ] ^1/2

In formula, (DELTA) a * is a difference between a * in a center part and a * in parts other than a center, and (DELTA) b * is a difference of b * corresponding to it. When the uniformity of the color of the reflected light in the surface of the circularly polarizing plate before heat resistance test is low, even if the color change of the reflected light before and after heat resistance is small, the improvement effect of visibility may become small. The heat resistance test can be performed by, for example, storing the circularly polarizing plate in a dryer set at a temperature of 80 ° C. for 168 hours.

<Use>

The circular polarizing plate can be used for various display devices. The display device is a device having a display element, and includes a light emitting element or a light emitting device as a light emitting source. As the display device, for example, a liquid crystal display device, an organic EL display device, an inorganic electroluminescence (hereinafter, also referred to as inorganic EL) display device, an electron emission display device (for example, an electric field emission display device (also referred to as FED), and a surface field emission) Display device (also called SED), electronic paper (display using electronic ink or electrophoretic element, plasma display device, projection display device (e.g. grating light valve (also known as GLV)) display device, digital micromirror device (also known as DMD) Display device), a piezoelectric ceramic display, etc. The liquid crystal display device includes both a transmissive liquid crystal display device, a transflective liquid crystal display device, etc. Such a display device includes a display for displaying a two-dimensional image. The device may be a stereoscopic display device that displays a three-dimensional image, and the circularly polarizing plate is particularly an organic EL display device or an inorganic E. It can use especially for L display apparatus.

In FIGS. 2A and 2B, the organic EL display devices 104 and 105 have a circular polarizing plate on the organic EL display element 3 through the pressure-sensitive adhesive layer 14 laminated on the retardation film 20. It has a layered structure laminated on it.

Example

(1) measuring method of film thickness

It measured using MH-15M which is a digital micrometer by Nikon Corporation.

2) Measuring method of phase difference

It measured using the phase difference measuring apparatus KOBRA-WPR (made by Ojikei Sokku Co., Ltd.).

[Production of Retardation Film 1]

5 parts (weight average molecular weight: 30,000) and 95 parts of cyclopentanone (solvent) of the photo-alignment material of the following structure were mixed, and the obtained mixture was stirred at 80 degreeC for 1 hour, and the composition for orientation film formation was obtained.

1.0 part of a leveling agent (F-556; DIC Corporation make) with respect to 100 parts of mixtures which mixed the polymeric liquid crystal compound A shown below and the polymeric liquid crystal compound B in the mass ratio of 90:10, and superposition | polymerization Six parts of 2-dimethylamino-2-benzyl-1- (4-morpholinophenyl) butan-1-one ("Igacure 369 (Irg369)", BASF Japan Corporation) was added as an initiator.

Furthermore, N-methyl-2-pyrrolidone (NMP) was added so that solid content concentration might be 13%, and the composition for liquid crystal cured film formation was obtained by stirring at 80 degreeC for 1 hour.

The polymeric liquid crystal compound A was manufactured by the method of Unexamined-Japanese-Patent No. 2010-31223. In addition, polymeric liquid crystal compound B was manufactured according to the method of Unexamined-Japanese-Patent No. 2009-173893. Each molecular structure is shown below.

(Polymerizable Liquid Crystal Compound A)

(Polymerizable Liquid Crystal Compound B)

[Manufacture of laminated body which consists of a base material, the orientation film, and the layer which hardened the polymeric liquid crystal compound]

As a base material, the corona treatment was performed on the 50 micrometer-thick cycloolefin resin film [brand name "ZF-14-50" by the Nippon Zeon Corporation]. The composition for forming an alignment film was applied to a surface subjected to corona treatment with a bar coater. The coating film was dried at 80 ° C. for 1 minute. The dried coating film was irradiated with polarized UV at an axial angle of 45 degrees using the polarizing UV irradiation device [trade name "SPOT CURE SP-9" of Ushio Denki Co., Ltd.], and the alignment film was obtained. Irradiation of polarization UV was performed so that accumulated light amount in wavelength 313 nm might be set to 100 mJ / cm <2>.

Subsequently, the composition for liquid crystal cured film formation was apply | coated on the oriented film using the bar coater. The coating film was dried at 120 ° C. for 1 minute. The dry coating film was irradiated with ultraviolet rays using a high pressure mercury lamp (trade name: "Unicure VB-15201 BY-A" by Ushio Denki Co., Ltd.). The irradiation process of ultraviolet-ray was performed in nitrogen atmosphere so that accumulated light amount in wavelength 365nm might be 250mJ / cm <2>. The cured film was thrown into oven set to 5 degreeC for 20 second as a cooling process immediately after irradiation. Immediately after taking out from the oven, the ultraviolet irradiation step and the cooling step were again performed to obtain a laminate comprising a base material, an alignment film, and a layer cured by the polymerizable liquid crystal compound.

(Measurement of phase difference value)

The adhesive layer was laminated | stacked on the layer which the polymeric liquid crystal compound of the laminated body hardened | cured. The laminated body was bonded to glass through this adhesive layer. Then, the base material with which a laminated body is equipped was peeled off, and the sample for evaluating a phase difference value was obtained. As a result, the layer which the polymerizable liquid crystal compound cured has Re (450) = 121 nm, Re (550) = 142 nm, and Re (650) = 146 nm as the phase difference values Re (λ) at each wavelength. Had. As a result, Re (450) / Re (550) = 0.85 and Re (650) / Re (550) = 1.03 were calculated. The layer which the polymeric liquid crystal compound hardened | cured was a layer which gives the phase difference of (lambda) / 4.

(Measurement of spinneret modulus)

The measurement of the puncture elasticity modulus was performed as follows. A needle was attached to a handy compression tester "KES-G5 Needle Penetration Measurement Specification" manufactured by Kato Tech Corporation. The needle (rotated) is rotated perpendicularly to the main surface of the laminate from which the substrate is peeled off and fixed between two plates having a circular hole having a diameter of 11 mm, and the force (gf) immediately before breaking is deformed (mm). The value divided by was calculated. This operation was performed with respect to five retardation films (samples for protrusion tests), respectively, and the average value was made into the puncture elasticity modulus of retardation film. As the needle, a tip diameter of 1 mmφ and 0.5 R was used. The speed of needle rotation was 0.33 cm / sec. The projection elastic modulus of the retardation film 1 is shown in Table 1.

[Production of Retardation Film 2]

When the coating film of the composition for forming a liquid crystal cured film is cured, the accumulated light amount per one time of ultraviolet rays irradiated is 400 mJ / cm 2 (that is, the total amount of two times of ultraviolet light irradiation is 800 mJ / cm 2) at a wavelength of 365 nm. A laminate including the retardation film 2 was produced in the same manner as in the [Production of the retardation film 1] except that it was made. In the same manner as above, the puncture elastic modulus of the retardation film 2 was measured. The puncture elasticity modulus of the retardation film 2 is shown in Table 1.

[Production of Phase Difference Film 3]

When curing the coating film of the composition for forming a liquid crystal cured film, the accumulated light amount per one time of ultraviolet rays irradiated is 600 mJ / cm 2 (that is, the total amount of two times of ultraviolet light irradiation is 1200 mJ / cm 2) at a wavelength of 365 nm. A laminate including the retardation film 3 was produced in the same manner as in the [Production of the retardation film 1] except for the above. In the same manner as above, the puncture elastic modulus of the retardation film 3 was measured. The puncture elasticity modulus of the retardation film 3 is shown in Table 1.

[Production of Retardation Film 4]

When the coating film of the composition for forming a liquid crystal cured film is cured, the accumulated light amount per one time of ultraviolet rays irradiated is 800 mJ / cm 2 (that is, the total amount of two times of ultraviolet light irradiation is 1600 mJ / cm 2) at a wavelength of 365 nm. A laminate including the retardation film 4 was produced in the same manner as in the [Production of the retardation film 1] except for the above. In the same manner as above, the puncture elastic modulus of the retardation film 4 was measured. The puncture elasticity modulus of the retardation film 4 is shown in Table 1.

[Production of Retardation Film 5]

As a composition for forming a vertical alignment film, 5 parts by weight of Sunever SE-610 (manufactured by Nissan Chemical Industries, Ltd.), which is a commercially available alignment polymer, and 95 parts by weight of methyl ethyl ketone (solvent) were mixed to prepare a composition for forming a vertical alignment film. Got it.

As a composition for vertical orientation retardation layer formation, 20 weight part of photopolymerizable nematic liquid crystal compounds (RMM28B by Melk Corporation), and 1 weight part of Igacure 907 (Irg-907 by BASF Corporation) as a photoinitiator are propylene glycol monomethyl ether It dissolved in 80 weight part of acetate, and prepared the coating liquid for vertical orientation retardation layer formation.

As a base material, the corona treatment was performed on the 50 micrometer-thick cycloolefin resin film [brand name "ZF-14-50" by the Nippon Zeon Corporation]. The composition for vertical alignment film formation was apply | coated with the bar coater on the surface to which corona treatment was performed. The coating film was heated at 100 ° C. for 120 seconds and cured to form a vertical alignment film.

The coating liquid for vertical alignment phase difference layer formation was apply | coated on the obtained vertical alignment film first, and the coating film was heated at the temperature of 80 degreeC for 60 second. Thereafter, ultraviolet (UVB) was irradiated so that the accumulated light amount was 220 mJ / cm 2, and the composition for vertical alignment retardation layer formation was polymerized and cured to form a vertical alignment retardation layer having a thickness of 0.7 μm on the vertical alignment film. The retardation value at wavelength 550 nm of the obtained vertically aligned retardation layer was measured, and Re (550) = 1 nm and Rth (550) = -75 nm. That is, the vertical alignment retardation layer was a positive C layer that satisfies the relationship of nx nny <nz. Moreover, since the phase difference value in wavelength 550nm of the cycloolefin resin film which is a base material is about 0, it does not affect the optical characteristic of a vertical alignment phase difference layer.

Subsequently, on the obtained vertically-oriented retardation layer, the layer which gives retardation of (lambda) / 4 was formed similarly to [the preparation of phase difference film 2], and the laminated body containing retardation film 5 was produced. Thus, the laminated body containing the retardation film 5 in which the base material, the vertical alignment film, the positive C layer, the alignment film, and the layer which gives retardation of (lambda) / 4 was laminated in this order was produced. In the same manner as above, the puncture elastic modulus of the retardation film 5 was measured. The puncture elasticity modulus of the retardation film 5 is shown in Table 1.

[Preparation of Adhesive Layer]

Adhesive A: Sheet-like adhesive of 5 micrometers in thickness ("NCF # L2" by the Intec Corporation)

Adhesive B: Sheet-like adhesive 25 micrometers in thickness ("P-3132" by the Intec Corporation)

[Preparation of Protective Film]

Protective film A: Film in which the hard-coat layer of thickness 3micrometer was formed in the stretched film which consists of norbornene-type resin of thickness 25micrometer [brand name "COP25ST-HC" by Nippon Seishi KK)

Protective film B: 20-micrometer-thick triacetyl cellulose film [brand name "ZRG20SL" by FUJIFILM Corporation]

Protective film C: Unstretched film consisting of triacetyl cellulose having a thickness of 25 μm

[Production of Front Panel]

The front plate which has a hard-coat layer on both sides of the base film was prepared. The base film was a 50-micrometer-thick polyimide film, and the thickness of the hard-coat layer was 10 micrometers.

Example 1

[Production of Polarizing Plate]

The polyvinyl alcohol film (average degree of polymerization of about 2400, saponification degree of 99.9 mol% or more) was uniaxially stretched by about 4 times by dry stretching and immersed in pure water at 40 ° C. for 40 seconds while maintaining a tension state again. Thereafter, the dyeing treatment was performed by immersing in an aqueous solution having a weight ratio of iodide / potassium iodide / water of 0.052 / 5.7 / 100 for 30 seconds at 28 ° C. Then, it was immersed at 70 degreeC for 120 second in the aqueous solution whose weight ratio of potassium iodide / boric acid / water is 11.0 / 6.2 / 100. Subsequently, the resultant was washed with pure water at 8 ° C. for 15 seconds, then dried at 60 ° C. for 50 seconds and then at 75 ° C. for 20 seconds while being maintained at a tension of 300 N. Iodine was adsorbed onto the polyvinyl alcohol film. A polarizer with a thickness of 7 μm was obtained.

The water-based adhesive agent was apply | coated to one surface of the polarizer, and the protective film A was bonded. At this time, the bonding direction of the protective film A was bonded so that it might be 45 degree | times with respect to the absorption axis of a polarizer. The water-based adhesive agent was apply | coated to the other surface of the polarizer, and the protective film B was bonded. Then, it dried and the polarizing plate was obtained. The aqueous adhesive dissolves 3 parts of carboxyl group-modified polyvinyl alcohol (trade name "KL-318" obtained from Kuraray Co., Ltd.) with respect to 100 parts of water, and is a polyamide epoxy clock additive which is a water-soluble epoxy resin [ 1.5 parts of brand name "Sumirez resin 650 (30)" and the aqueous solution of 30% of solid content concentration by the Takaoka Chemical Co., Ltd. make are added.

The adhesive A was laminated | stacked on the layer which the polymeric liquid crystal compound in the laminated body produced by [production of retardation film 2] hardened | cured. Next, the base material was peeled from the laminated body, and the adhesive B was laminated | stacked on the surface which peeled and exposed. Thus, the retardation film 2 with a double-sided adhesive which consists of a layer which the adhesive A, the polymeric liquid crystal compound hardened | cured, the orientation film, and the adhesive B was produced.

[Production of Circular Polarizer Plate]

The retardation film 2 with a double-sided adhesive was bonded on the protective film B in the said polarizing plate via the adhesive A in the retardation film 2 with a double-sided adhesive. The slow axis of the layer which hardened the polymeric liquid crystal compound was 45 degrees with respect to the absorption axis of a polarizer, and was 90 degrees with respect to the extending | stretching direction of the protective film A. FIG. Thus, the circularly-polarizing plate which consists of a protective film A, an aqueous adhesive layer, a polarizer, an aqueous adhesive layer, a protective film B, the adhesive A, the layer which hardened the polymeric liquid crystal compound, the orientation film, and the adhesive B was produced.

The circularly polarizing plate was cut into the rectangle of the size of 140 mm x 70 mm so that the slow axis of the layer which hardened the polymeric liquid crystal compound may be parallel to a long side. At this time, the extending direction of the protective film A was parallel with the short side direction. The cut circular polarizing plate was bonded by the glass plate (The Corning company make, product number: EAGLE XG (registered trademark)) of thickness 0.4mm through the adhesive B. In this way, the sample for evaluation was produced.

Example 2

In Example 1, a circularly-polarizing plate was produced in the same manner as in Example 1 except that the laminate produced in [Production of phase difference film 3] was used instead of the laminate produced in [Production of phase difference film 2]. And samples for evaluation were produced.

Example 3

In Example 1, a circularly-polarizing plate was produced in the same manner as in Example 1 except that the laminate produced in [Production of phase difference film 4] was used instead of the laminate produced in [Production of phase difference film 2]. And the sample for evaluation was produced.

Example 4

In Example 2, what bonded the protective film A to the polarizer so that the slow axis of the layer which hardened the polymeric liquid crystal compound is 45 degree | times with respect to the absorption axis of a polarizer, and 0 degree | times with respect to the extending | stretching direction of protective film A. A circularly polarizing plate was produced in the same manner as in Example 2 except that a sample for evaluation was produced. At this time, the extending direction of the protective film A was parallel with the long side direction.

Example 5

In Example 1, a circularly-polarizing plate was produced in the same manner as in Example 1 except that the laminate produced in [Production of phase difference film 5] was used instead of the laminate produced in [Production of phase difference film 2]. And the sample for evaluation was produced.

Example 6

A circularly polarizing plate was produced in the same manner as in Example 1 except that the protective film B was not laminated at the time of preparing the polarizing plate. Moreover, the adhesive layer B was laminated | stacked on the protective film A. The front plate and the circular polarizer were bonded to each other via the pressure-sensitive adhesive layer B. Thus, the circularly-polarizing plate which consists of a front plate, an adhesive layer B, the protective film A, an aqueous adhesive layer, a polarizer, an adhesive A, the layer which hardened the polymeric liquid crystal compound, the alignment film, and the adhesive B was produced. Moreover, it carried out similarly to Example 1, and produced the sample for evaluation.

Example 7

[Composition for Surface Treatment Layer Formation]

The following components were mixed to prepare a composition for forming a surface treatment layer.

2.0 parts by mass of a dendrimer acrylate (Miramer SP1106, Miwon) having an 18-functional acrylic group,

10.0 parts by mass of urethane acrylate (Miramer PU-620D, Miwon) having a six-functional acrylic group,

8.0 parts by mass of acrylate monomer (M340, Miwon) having a trifunctional acrylic group,

2 parts by mass of a photopolymerization initiator (Irgacure-184, manufactured by BASF)

0.1 part by mass of leveling agent (BYK-3530, BYK),

Methyl ethyl ketone (MEK) 77.9 parts by mass

[Composition for Polarizer Formation]

(Polymerizable Liquid Crystal Compound)

The polymerizable liquid crystal compound is a polymerizable liquid crystal compound represented by the formula (1-6) (hereinafter also referred to as compound (1-6)) and a polymerizable liquid crystal compound represented by the formula (1-7) [hereinafter, a compound ( Also referred to as 1-7).

Compound (1-6) and compound (1-7) are described in Lub et al. Recl. Trav. Chim. Pays-Bas, 115, 321-328 (1996)].

(Dichroic dye)

The azo dye as described in the Example of Unexamined-Japanese-Patent No. 2013-101328 represented by following formula (2-1a), (2-1b), (2-3a) was used for a dichroic dye.

The composition for polarizing layer formation is represented by the said Formula (2-1a), (2-1b), (2-3a) as 75 parts of compounds (1-6), 25 parts of compounds (1-7), and a dichroic dye. 2.5 parts of each azo dye, 6 parts by weight of 2-dimethylamino-2-benzyl-1- (4-morpholinophenyl) butan-1-one (Irgacure 369, manufactured by BASF Japan) as a polymerization initiator, and a leveling agent 1.2 parts of as polyacrylate compounds (BYK-361N, BYK-Chemie Co., Ltd.) were mixed with 400 parts of toluene of a solvent, and it prepared by stirring the obtained mixture at 80 degreeC for 1 hour.

The composition for surface treatment layer formation was apply | coated to the protective film A. The coating film was dried at 80 ° C. for 5 minutes, and then UV was irradiated using a UV irradiation device so that the exposure amount was 500 mJ / cm 2 (365 nm standard) to cure the coating film. SPOT CURE SP-7 and Ushio Denki Co., Ltd. product were used for the UV irradiation apparatus. The thickness of the surface treatment layer was 10.0 µm.

On the surface treatment layer in protective film A, the composition for oriented film formation used by preparation of retardation film 1 was apply | coated by the bar coat method. The coating film was dried at 80 ° C. for 1 minute. Subsequently, polarizing UV was irradiated to the coating film using the said UV irradiation apparatus and the wire grid, and orientation performance was provided to the coating film. The exposure amount was 100 mJ / cm 2 (365 nm reference). As the wire grid, UIS-27132 ## (manufactured by Ushio Denki Co., Ltd.) was used. In this way, an alignment film was formed. The thickness of the alignment film was 100 nm.

On the formed alignment film, the composition for polarizer formation was apply | coated by the bar coat method. The coating film was heated to dry at 100 ° C. for 2 minutes and then cooled to room temperature. Using the said UV irradiation apparatus, the polarizer was formed by irradiating an ultraviolet-ray to the coating film with the accumulated light quantity 1200mJ / cm <2> (365 nm reference | standard). The thickness of the obtained polarizer was 3 micrometers. On the polarizer, the composition containing polyvinyl alcohol and water was coated so that the thickness after drying might be set to 0.5 micrometer, and it dried at the temperature of 80 degreeC for 3 minutes, and formed the protective layer. Thus, the polarizing plate which consists of protective film A, a surface treatment layer, an orientation film, a polarizer, and a protective layer was produced.

Except having used the said polarizing plate, it carried out similarly to Example 6, the circular polarizing plate was produced, and the sample for evaluation was produced. The sample for evaluation was equipped with the front plate, the adhesive layer B, the protective film A, the surface treatment layer, the alignment film, the polarizer, the protective layer, the adhesive A, the layer which the polymerizable liquid crystal compound hardened | cured, the alignment film, and the adhesive B in this order. .

Example 8

A circular polarizing plate was produced in the same manner as in Example 7 except that the protective film C was used instead of the laminate of the protective film A and the surface treatment layer, and a sample for evaluation was produced. The sample for evaluation was equipped with the front plate, the adhesive layer B, the protective film C, the alignment film, the polarizer, the protective layer, the adhesive A, the layer which the polymeric liquid crystal compound hardened | cured, the alignment film, and the adhesive B in this order.

Example 9

Except not having laminated | stacked the front plate, it carried out similarly to Example 8, the circular polarizing plate was produced, and the sample for evaluation was produced. The sample for evaluation was equipped with the protective film C, the orientation film, the polarizer, the protective layer, the adhesive A, the layer which hardened the polymeric liquid crystal compound, the orientation film, and the adhesive B in this order.

Comparative Example 1

In Example 1, a circularly-polarizing plate was produced in the same manner as in Example 1 except that the laminate produced in [Production of phase difference film 1] was used instead of the laminate produced in [Production of phase difference film 2]. And samples for evaluation were produced.

[Color evaluation before and after heat test]

As a reflecting plate, MIRO (5011GP) made from ALANOD Corporation was prepared. This reflecting plate is a mirror reflecting plate having a reflecting surface formed by vapor deposition.

The sample for evaluation was placed on the reflecting plate. The color (a *, b *) of reflected light was measured using the spectrophotometer (Konica Minolta Japan Co., Ltd. brand name: CM-2600d). The color of the reflected light was a value when the light source was D65, and was measured by the SCI method (including specular reflection light).

Specifically, point 5 shown in FIG. 3 was used as a measuring point. Nine points 5 shown in FIG. 3 are points in an area 5 mm inward from the end of the circular polarizing plate, and the short sides are located at intervals of about 30 mm and the long sides are located at intervals of about 65 mm.

About the evaluation sample produced in the said Examples 1-9 and the comparative example 1, the color of the reflected light before and after storing for 168 hours in the dryer of 80 degreeC was measured. The absolute value of the color change (DELTA) a * b * of each point was computed. The color change value of each point was computed based on the direction of a color change, and the difference between the maximum value and the minimum value of the color change value of each evaluation sample was made into (DELTA) a * b * (MAX-MIN). The results are shown in Tables 2 and 3.

Δa * = a * (after heat test) -a * (before heat test)

Δb * = b * (after heat test) -b * (before heat test)

Δa * b * = [(Δa *) 2 + (Δb *) 2] 1/2

In addition, the color change value was made into (DELTA) a * b * when (DELTA) a * was 0 or more, and it was set as (DELTA) a * b **-1 when (DELTA) a * was smaller than zero.

ADVANTAGE OF THE INVENTION According to this invention, it is useful as a circularly polarizing plate provided with a retardation film, since it can provide the circularly polarizing plate with a small change of color before and after putting in a high temperature environment.

1: polarizer
2: retardation film
3: organic EL display element
4: front panel
5: dot
10: polarizer
11, 12: protective film
13, 14, 16: adhesive layer
15: adhesive layer
20, 21: layer which the polymerizable liquid crystal compound cured
100, 101, 102, 103: circularly polarizing plate
104, 105, and 106: organic EL display device

Claims (7)

A circular polarizing plate having a polarizing plate and a retardation film,
The retardation film includes a retardation layer,
The retardation film has a modulus of elasticity of 15 gf / mm or more,
Said elasticity modulus of the circular polarizing plate whose elasticity modulus is measured by the test in which the projection speed is 0.33 cm / sec using the needle whose tip diameter is 1 mm (phi) and 0.5R. The method of claim 1,
The circular polarizing plate has an adhesive layer on its surface,
The polarizing plate has a polarizer,
The retardation layer includes a layer cured by a polymerizable liquid crystal compound,
The retardation film is a circularly polarizing plate which is disposed between the polarizing plate and the pressure-sensitive adhesive layer. The circularly polarizing plate of claim 2, wherein the polarizer is formed of a hardened layer of a liquid crystal compound. The method according to claim 2 or 3,
The circular polarizing plate is substantially rectangular in shape,
In the said polarizing plate, the protective film is laminated | stacked on the surface on the opposite side to the retardation film side of the said polarizer,
The protective film is a stretched film,
The circular polarizing plate of which the extending direction of the said protective film and the short side direction of a circular polarizing plate are substantially parallel. The circularly polarizing plate according to any one of claims 1 to 4, wherein the retardation film includes two retardation layers. The circularly-polarizing plate with a front plate by which the circularly-polarizing plate and front plate of any one of Claims 1-5 were laminated | stacked through the adhesive layer. The display device in which the circularly-polarizing plate in any one of Claims 2-4 is laminated | stacked on the display element via the said adhesive layer.

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