KR20190103961A - Circular polarizing plate - Google Patents

Abstract

The present invention relates to a circular polarizing plate comprising a retardation film containing a layer formed by curing a liquid crystal compound. The purpose of the present invention is to provide a circular polarizing plate which is placed at high temperatures while a front plate such as cover glass is bonded thereto and then a change in the color of reflected light from an initial state thereof can be inhibited. The circular polarizing plate comprises: a polarizing plate in which a first protective film is stacked on one side of a polarizer and a second protective film is stacked on the other side of the polarizer; and a retardation film which contains a layer formed by curing a polymeric liquid crystal compound. In addition, the circular polarizing plate satisfies at least one of conditions 1 and 2 in which according to condition 1, formula (1), (1/x+1/y >= 0.0030), is satisfied when the water vapor transmission rate of the first protective film is set to x(g/m^2·24 hr), and the water vapor transmission rate of the second protective film is set to y(g/m^2·24 hr), and according to condition 2, the moisture ratio of the polarizing plate is 3.00% or less.

Description

Circular polarizer {CIRCULAR POLARIZING PLATE}

The present invention relates to a circular polarizer.

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

With the rise of organic EL display devices, as the demand for thinning an image display device becomes stronger, thinning is also required for circular polarizing plates. 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 a polymeric liquid crystal compound on a base material and orientating, and irradiating light as needed and fixing an orientation state.

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

However, when the circularly polarizing plate having the retardation film formed from the polymerizable liquid crystal compound is provided with a front plate and placed in a high temperature environment, the problem is that the reflected light becomes red, specifically, the reflected light becomes red from the initial state in the center of the circularly polarizing plate. There was.

An object of the present invention is a circular polarizing plate comprising a retardation film comprising a layer cured by a liquid crystal compound, which is placed under a high temperature environment in a state in which a front plate such as a cover glass is bonded, thereby suppressing color change of reflected light from an initial state. It is to provide a circular polarizer that can be.

[1] a retardation film including a polarizing plate having a first protective film laminated on one side of the polarizer, a second protective film laminated on the other side of the polarizer, and a layer cured by the polymerizable liquid crystal compound;

The circular polarizing plate which satisfy | fills at least one among the following conditions 1 and 2.

Condition 1: Formula (1) is satisfied when the water vapor transmission rate of the said 1st protective film is set to x (g / m <2> * 24hr), and the water vapor transmission rate of the said 2nd protective film is set to y (g / m <2> * 24hr). do.

  1 / x + 1 / y≥0.0030 Formula (1)

Condition 2: The moisture content of the said polarizing plate is 3% or less.

[2] The circular polarizing plate according to claim 1, which satisfies both condition 1 and condition 2.

[3] The circular polarizing plate according to claim 1 or 2, wherein the polarizing plate includes a front plate on a side opposite to the side on which the retardation film is laminated.

[4] The circular polarizing plate according to any one of claims 1 to 3, wherein the polarizer has a thickness of 13 µm or less.

According to this invention, in the circular polarizing plate provided with the retardation film containing the layer which the liquid crystal compound hardened | cured, after changing in the high temperature environment in the state which bonded front plates, such as a cover glass, the color change of the reflected light from an initial state is carried out. It can be suppressed.

1 is an example of schematic sectional drawing which shows the laminated constitution of a circular polarizing plate.
It is an example of schematic sectional drawing which shows the laminated constitution of a circular polarizing plate.
3 is an example of schematic sectional drawing which shows the layer structure of an organic electroluminescence display.

<Circular polarizer>

The circular polarizing plate of the present invention includes a polarizing plate and a retardation film. The polarizing plate and the retardation film can be laminated through, for example, an adhesive layer. As an adhesive layer, the adhesive layer and adhesive bond layer mentioned later are mentioned, for example. In this invention, a polarizing plate means the laminated body which consists of a polarizer and the protective film respectively bonded to both surfaces of a polarizer.

Hereinafter, with reference to FIG. 1, an example of the laminated constitution of the circular 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. This laminated polarizing plate 1 and the retardation film 2 containing the layer 20 which the polymeric liquid crystal compound hardened | cured have the laminated constitution laminated | stacked through the adhesive layer 13. As shown in FIG. In addition, the circular polarizing plate 100 has the adhesive layer 14 in the surface on the opposite side to the polarizing plate 1 in the retardation film 2. The adhesive layer 14 may be an adhesive layer for bonding to an organic electroluminescent display element etc.

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. This laminated polarizing plate 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 constitution in which the layer 20 on which the polymerizable liquid crystal compound is cured and the layer 21 on 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 in the retardation film 2. The adhesive layer 14 may be an adhesive layer for bonding to an organic electroluminescent display element etc.

As shown in FIG. 1, the retardation film may have one layer which hardened the polymeric liquid crystal compound, and may have two layers. In addition, the retardation film may have the orientation film for orientating a polymeric liquid crystal compound, and a base film.

The circular polarizing plate can have layers other than the layer shown in FIG. 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 disposed on the side opposite to the side on which the retardation film is laminated in the polarizing plate. In the circular polarizing plate 102 shown in FIG. 2A, the front plate 4 is laminated on the circular polarizing plate 100, and the front plate 4 is attached to the polarizing plate 1 via the pressure-sensitive adhesive layer 16. It is stacked. In the circular polarizing plate 103 shown in FIG. 2B, the front plate 4 is laminated on the circular polarizing plate 101, and the front plate 4 is attached to the polarizing plate 1 via the pressure-sensitive adhesive layer 16. It is stacked.

A light shielding pattern can be formed on the surface of the polarizing plate side in a front plate. The light shielding pattern can be formed in a frame (non-display area) of the image display device, so that the wiring of the image display device is not visually recognized by the user.

The circular polarizing plate of the present invention satisfies at least one of condition 1 and condition 2 below.

Condition 1: Formula (1) is satisfied when the water vapor transmission rate of the said 1st protective film is set to x (g / m <2> * 24hr), and the water vapor transmission rate of the said 2nd protective film is set to y (g / m <2> * 24hr). do.

  1 / x + 1 / y≥0.0030 Formula (1)

Condition 2: The moisture content of the said polarizing plate is 3.00% or less.

When the circular polarizing plate satisfies at least one of the above conditions 1 and 2, the color of the central portion of the circular polarizing plate can be prevented from changing when the circular polarizing plate is placed under a high temperature environment. It is preferable that the circularly polarizing plate satisfies both the condition 1 and the condition 2 above.

More specifically, in Formula (1), 1 / x + 1 / y is 0.0030 or more, It is preferable that it is 0.010 or more, It is more preferable that it is 0.020 or more, It is further more preferable that it is 0.050 or more. Although an upper limit is not specifically limited, 1 / x + 1 / y is 0.2 or less normally.

In more detail, the moisture content of a polarizing plate is 3.00% or less, it is preferable that it is 2.50% or less, and it is more preferable that it is 2.00% or less. Although a minimum in particular is not restrict | limited, The moisture content of a polarizing plate is 0.50% or more normally, and 1.00% or more may be sufficient. The measuring method of moisture content is based on the method as described in the Example mentioned later.

Although this invention is not restrict | limited at all, the reason which can prevent the reflected light from discoloring red by satisfying conditions 1 and 2 is estimated as follows. By examination of this inventor, it turned out that the phenomenon which the reflected light from the center part of a circularly polarizing plate turns red is caused by the fall of the phase difference value of a retardation film. It was estimated that the fall of the retardation value of retardation film arises when water contained in a polarizing plate moves to retardation film. Therefore, the moisture content contained in a polarizing plate may be below predetermined value, the quantity of water which can be transferred to a retardation film may be made small, or the moisture permeability of the protective film with which a polarizing plate is equipped may be below a predetermined value, and moisture may transfer to a retardation film. It is available to make difficult.

Condition 2 is based on the above estimation, and by making the moisture content of the polarizing plate within the above range, the reflected light from the circular polarizing plate can be prevented from becoming red. On the other hand, condition 1 is unexpectedly important for preventing not only the moisture permeability of the protective film on the side closer to the retardation film in the polarizing plate, but also the moisture permeability of the protective film on the side farther from the retardation film in the polarizing plate to prevent discoloration of the reflected light of the circular polarizing plate. It is based on what is revealed. According to the examination of the present inventor, by selecting the water vapor transmission rate of the protective film bonded to both surfaces of a polarizing plate so that said condition 1 may be satisfied, the reflected light from a circularly polarizing plate can be prevented from becoming red.

When the circular polarizing plate of this invention is heated at 85 degreeC for 400 hours, it is preferable that the magnitude [(Delta) Re (nm) of the fall amount of the phase difference value of the in-plane center (it may be the position of the center of gravity of a circular polarizing plate) is 10 nm or less, It is more preferable that it is 8 nm or less. The retardation value adopts a value at a wavelength of 547 nm. By setting it as such a range, the color change of a circularly polarizing plate can be made small, and the circularly polarizing plate with favorable external appearance is obtained.

The shape of the circular polarizing plate of the present invention is not particularly limited. When a circular polarizing plate is substantially rectangular, it is preferable that the length of a long side is 5 cm or more and 35 cm or less, It is more preferable that it is 10 cm or more and 25 cm or less, It is preferable that the length of a short side is 5 cm or more and 25 cm or less, It is 6 cm. As for more than 20 cm, it is more preferable. If it is such a size, moisture is hard to be filled.

Substantially rectangular is a circular polarizing plate each having a shape or rounded shape in which at least one corner portion of four corners (angular portions) of the main surface is obtuse, or a portion of an end surface perpendicular to the main surface moves in the in-plane direction. It may have a recessed part (notch), or a part of the main surface may have a perforated part removed in a shape such as a circle, an ellipse, a polygon, or a combination thereof.

<Polarizing plate>

In this invention, a polarizing plate means the laminated body which consists of a polarizer and the protective film respectively bonded to both surfaces 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 linearly 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 according to the method including 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. As polyvinyl acetate type resin, besides polyvinyl acetate which is a homopolymer of vinyl acetate, the copolymer with the other monomer copolymerizable with vinyl acetate, etc. are mentioned. 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 this specification, "(meth) acryl" means at least one selected from acryl and methacryl. The same applies to "(meth) acryloyl", "(meth) acrylate" and the like.

The 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 polymerization degree of polyvinyl alcohol-type resin can be calculated | required based on JISK6726.

What just produced such polyvinyl alcohol-type resin is used as a raw film of a polarizer. The method of film-forming a polyvinyl alcohol-type resin is not specifically limited, A well-known method is employ | adopted. Although the thickness of a polyvinyl alcohol-type raw film is not specifically limited, In order to make thickness of a polarizer into 15 micrometers or less, it is preferable to use 5-35 micrometers. 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 perform uniaxial stretching in these several steps.

In uniaxial stretching, you may extend | stretch uniaxially between the rolls from which a circumferential speed differs, and 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 the film in the aqueous solution containing a dichroic dye is employ | adopted, for example. As a dichroic dye, iodine or a dichroic organic dye is used. Moreover, it is preferable that the polyvinyl alcohol-type resin film is immersed in water before a dyeing process.

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. In particular, the thickness of the polarizer to be 15 µm or less is advantageous for reducing the amount of water in the polarizing plate per unit area. The thickness of a polarizer is 2 micrometers or more normally, and it is preferable that it is 3 micrometers or more.

As a polarizer, as described, for example, in Unexamined-Japanese-Patent No. 2016-170368, you may use what the dichroic dye orientated in the cured film which the liquid crystal compound superposed | polymerized. As a dichroic dye, what has absorption in the range of wavelength 380-800 nm can be used, 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. As described in WO2011 / 024891, a polarizer may be formed of a dichroic dye having liquid crystallinity.

(2) protective film

It is preferable that it is 500 g / m <2> * 24hr or less, as for the water vapor transmission rate of the protective film (1st protective film) of the side far from a retardation film based on a polarizer, it is more preferable that it is 200 g / m <2> * 24hr or less, 100 g It is more preferable that it is / m <2> * 24hr or less, and 50g / m <2> * 24hr or less may be sufficient. The lower limit is not particularly limited, but is usually greater than 0 g / m 2 · 24 hr.

It is preferable that it is 500 g / m <2> * 24hr or less, as for the water vapor transmission rate of the protective film (2nd protective film) of the side near a retardation film based on a polarizer, it is more preferable that it is 200g / m <2> * 24hr or less, 100 g It is more preferable that it is / m <2> * 24hr or less, and 50g / m <2> * 24hr or less may be sufficient. The lower limit is not particularly limited, but is usually greater than 0 g / m 2 · 24 hr.

The first and second protective films may be the same moisture permeability or different moisture permeability. The moisture permeability can be measured on the conditions of temperature 40 degreeC and 90% of a relative humidity according to the moisture permeability test (cup method) of JISZ0208.

The protective film laminated | stacked on both surfaces of a polarizer is a thermoplastic resin which has a translucent (preferably optically transparent), for example, chain polyolefin resin (polypropylene resin etc.), cyclic polyolefin resin (norbornene resin) Polyolefin resins such as); 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.

As chain-type polyolefin resin, polyethylene resin (polyethylene resin which is a homopolymer of ethylene and copolymer mainly ethylene), polypropylene resin (polypropylene resin which is a homopolymer of propylene, and copolymer mainly propylene) In addition to the homopolymer of the linear olefins such as the above, a copolymer composed of two or more kinds of the linear olefins may be mentioned.

The cyclic polyolefin resin is a generic term for resins that are polymerized using cyclic olefins as polymerized units, for example, JP-A-240517, JP-A-3-14882, JP3-122137 And resins described in Japanese Patent Application Laid-Open. Specific examples of the 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 their hydrides. 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 resins include 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 a compound having methyl methacrylate with an alicyclic hydrocarbon group (for example, methyl methacrylate-cyclohexyl copolymer, methyl methacrylate-norbornyl copolymer, etc.). Preferably, the poly (meth) poly (meth) acrylic polymer containing as a main component a C _{1 -6} alkyl ester is used, and more preferably, the main component methyl methacrylate (50 to 100% by weight, such as methyl acrylate, Preferably, the methyl methacrylate resin used as 70-100 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 to which the monomeric unit couple | bonded through the carbonato 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 retardation value Re (550) at wavelength 550nm is 10 nm or less, and the absolute value of the thickness direction retardation value Rth at wavelength 550nm is 10 nm or less. Say. 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 retardation layer (or film) having a single layer or a multilayer structure can 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 both surfaces of a polarizer may be comprised with the thermoplastic resin of the same kind, and may be comprised with the heterogeneous thermoplastic resin. Moreover, thickness may be the same and may differ. Moreover, they may have the same retardation characteristic and may have a different retardation characteristic.

As described above, at least one of the protective films has a hard coat layer, an antiglare layer, a light diffusion layer, an antireflection layer, a low refractive index layer, an antistatic layer, and an antifouling layer on its outer surface (surface opposite to the polarizer). A 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 and an active energy ray curable adhesive agent. As an adhesive layer, what is 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 copolymer obtained by saponifying the copolymer of vinyl acetate and the other monomer copolymerizable with this. Or a modified polyvinyl alcohol polymer obtained by partially modifying these hydroxyl groups. 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, visible light, an electron beam, and X-ray, Preferably it is an ultraviolet curable adhesive agent.

The curable compound may be a cationic polymerizable curable compound or a radical polymerizable curable compound. Examples of the cationic polymerizable curable compound include epoxy compounds (compounds having one or two or more epoxy groups in the molecule), oxetane compounds (compounds having one or two or more oxetane rings in the molecule), or these And combinations thereof. As a radically polymerizable curable compound, it is a (meth) acrylic-type compound [the compound which has 1 or 2 or more (meth) acryloyloxy groups in a molecule | numerator], the other vinyl type compound which has a radically polymerizable double bond, for example, or A combination of these. You may use together a cationic polymerizable curable compound and a radical 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-treat at least any 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, ionizing active line treatment (ultraviolet treatment, electron beam treatment, etc.); Wet processes, such as the ultrasonication, saponification process, and anchor coat process using solvents, such as water and acetone, are mentioned. These surface activation processes may be performed independently and may combine 2 or more.

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

<Phase difference film>

The retardation film has a layer composed of a composition containing a polymerizable 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 base material and orientation film mentioned later.

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 base material functions as a releasable support body, and can support the retardation layer for transfer. 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 cutting a base material and making it into a base material of a single | leather, the increase of a process waste and abrasion of a cutting blade can be suppressed.

In addition, the base material may be subjected to various blocking prevention treatments. Examples of the antiblocking treatment include an easy-adhesion treatment, a treatment of peeling fillers, and the like, embossing (knurling treatment), and the like. By performing such a blocking prevention process with respect to a base material, it can prevent the sticking of the base materials at the time of winding up a base material, what is called blocking, effectively, and can 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 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 tolerance which does not melt | dissolve by coating of the composition containing the polymeric liquid crystal compound mentioned later, etc., 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, a photo 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.

As resin used for an oriented film, if it is resin used as a material of a well-known aligning film, it will not specifically limit, The hardened | cured material etc. which hardened the conventionally well-known monofunctional or polyfunctional (meth) acrylate type monomer under a polymerization initiator can be used. have. Specifically, as the (meth) acrylate monomer, 2-ethylhexyl acrylate, cyclohexyl acrylate, diethylene glycol mono 2-ethylhexyl ether acrylate, diethylene glycol monophenyl ether acrylate, tetraethylene glycol, for example Monophenyl ether acrylate, trimethylol propane triacrylate, lauryl acrylate, lauryl methacrylate, isobornyl acrylate, isobornyl methacrylate, 2-phenoxyethyl acrylate, tetrahydrofurfuryl acryl Latex, 2-hydroxypropyl acrylate, benzyl acrylate, tetrahydrofurfuryl methacrylate, 2-hydroxyethyl methacrylate, benzyl methacrylate, cyclohexyl methacrylate, methacrylic acid, urethane acrylate, etc. Can be illustrated. Moreover, as resin, these 1 type may be sufficient and 2 or more types of mixtures may be sufficient.

Although it does not specifically limit about the kind of polymeric liquid crystal compound used by this embodiment, From the shape, it can classify into the bar type (rod type liquid crystal compound) and disk type (disk type liquid crystal compound, discotic liquid crystal compound). 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, Doi Masao, p. 2, Iwanami Shoten, 1992).

In this embodiment, any polymeric liquid crystal compound 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.

Moreover, as a rod-shaped liquid crystal compound, the thing of Claim 1 of Unexamined-Japanese-Patent No. 11-513019, or the paragraph of [0026]-[0098] of Unexamined-Japanese-Patent No. 2005-289980 can be used suitably, for example. . As the discotic liquid crystal compound, for example, paragraphs [0020] to [0067] of JP 2007-108732 A, or paragraphs [0013] to [0108] of JP 2010-244038 A 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, it is not necessary to already show liquid crystal after forming a layer.

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 the polymeric liquid crystal compound hardened | cured can be formed by coating the composition containing a polymeric liquid crystal compound on an alignment film, for example, as mentioned 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 polymerization reaction. For example, as a photoinitiator, the (alpha)-carbonyl compound, the acyloin ether, the (alpha) -hydrocarbon substituted aromatic acyloin compound, a polynuclear quinone compound, the combination of a triaryl imidazole 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%.

The composition may also contain a polymerizable monomer in terms of the uniformity of the coating film and the strength of the film. As a polymerizable monomer, a radically polymerizable or cationic polymerizable compound is mentioned. 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. As a specific polymerizable monomer, the thing of Paragraph [0018]-[0020] of Unexamined-Japanese-Patent No. 2002-296423 is mentioned, for example. 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. As a specific surfactant, For example, the compound of Paragraph [0028]-[0056] of Unexamined-Japanese-Patent No. 2001-330725, the compound of Paragraph [0069]-[0126] of the specification of Unexamined-Japanese-Patent No. 2003-295212. Can be mentioned.

In addition, a solvent may be contained in the said composition, and an organic solvent is used preferably. As an 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. Especially, alkyl halide and ketone are preferable. Moreover, you may use together 2 or more types of organic solvents.

Moreover, the said composition contains various orientation agents, such as a vertical orientation promoter, such as a polarizer interface side vertical aligning agent and an air interface side vertical aligning agent, and horizontal alignment 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.

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 arbitrarily combined. 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 and a retardation value in the thickness direction of the layer giving a phase difference of λ / 4, the layer giving a phase difference of λ / 2, or the positive C layer 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 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 / 2. It is preferable that it is a layer which gives the phase difference of. In the case where the retardation film includes two layers of the cured polymerizable liquid crystal compound, the retardation film is prepared by forming the cured layers of the polymerizable liquid crystal compound on the alignment film, respectively, and laminating them through the adhesive layer or the pressure-sensitive adhesive layer. It can manufacture. 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 excellent in transparency, weather resistance, heat resistance, etc. as a base polymer is suitable. An active energy ray hardening type or a thermosetting type may be sufficient as an adhesive composition. The thickness of an adhesive layer is 3-30 micrometers normally, Preferably it is 3-25 micrometers.

As (meth) acrylic-type resin (base polymer) used for an adhesive composition, it is (meth), such as butyl (meth) acrylate, ethyl (meth) acrylate, isooctyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate, for example. 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. As a polar monomer, it is (meth) acrylic acid, (meth) acrylic acid 2-hydroxypropyl, (meth) acrylic acid 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 dill (meth) acrylate is mentioned.

Although the adhesive composition may contain 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, what forms an amide bond between carboxyl groups is illustrated. Especially, a polyisocyanate compound is preferable.

<Front plate>

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 adhesive layer and adhesive bond layer mentioned above are mentioned, for example. As shown to Fig.2 (a), (b), the front plate 4 can be laminated | stacked on the 1st protective film 11 in the polarizing plate 1 through the adhesive layer 16. As shown to FIG.

When a front plate is laminated | stacked on a circularly polarizing plate, the reflected light from a circularly polarizing plate tends to discolor red. It is considered that the front plate often has low moisture permeability, and moisture contained in the polarizing plate tends to be filled. Therefore, when the circular polarizing plate of this invention is equipped with a front plate, it exhibits a remarkable effect.

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 a hard coat layer is not specifically limited, For example, 5-100 micrometers may be sufficient.

Examples of the resin film include cycloolefin derivatives having units of monomers containing cycloolefins such as norbornene or polycyclic norbornene monomers, cellulose (diacetyl cellulose, triacetyl cellulose, acetyl cellulose butyrate, isobutyl ester cellulose, Propionyl cellulose, butyryl cellulose, acetyl propionyl cellulose) ethylene-vinyl acetate copolymer, polycycloolefin, polyester, polystyrene, polyamide, polyetherimide, polyacryl, polyimide, polyamideimide, polyethersulfone, Polysulfone, polyethylene, polypropylene, polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl acetal, polyether ketone, polyether ether ketone, polyether sulfone, polymethyl methacrylate, polyethylene tere Phthalate, poly A film formed of a polymer such as butylene terephthalate, polyethylene naphthalate, polycarbonate, polyurethane or epoxy may be used. 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 a resin film, the polyamideimide film or polyimide film which is excellent in transparency and heat resistance, the uniaxial or biaxially stretched polyester film, the cycloolefin derivative film which is excellent in transparency and heat resistance, and can respond to enlargement of a film, polymethyl Preferred are methacrylate films and transparent and optically anisotropic triacetylcellulose and isobutyl ester cellulose films. The thickness of a resin film is 5-200 micrometers, Preferably, 20-100 micrometers may be sufficient.

The hard coat layer can be formed by curing a hard coat composition containing a reactive material that forms a crosslinked structure by irradiating light or thermal energy. The said hard coat layer can be formed by hardening of the 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 a solvent, a photoinitiator and an additive. The additive may include one or more selected from the group consisting of inorganic nanoparticles, leveling agents, and stabilizers, and in addition, each component generally used in the art may include, for example, antioxidants, UV absorbers, surfactants, It may further include a lubricant, an antifouling agent 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 a light shielding pattern and a display part, and visibility of a boundary part, a shape can be given to a light shielding pattern. For example, the inclination angle of the light shielding pattern with the front plate on which the light shielding pattern is formed may be 0.1 ° to 25 ° in a surface adjacent to the display unit.

<Method for Producing Circular Polarizer>

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 through the 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, it may cut and manufacture to a predetermined shape, and may cut together after cutting each member to a predetermined shape. After bonding the protective films 11 and 12 to the polarizer 10, in order to adjust the moisture content of a polarizing plate, you may provide a heating process and a humidity control process. Subsequently, the pressure-sensitive adhesive layer 13 formed on the release film is laminated on the protective film 12.

The retardation film 2 can be manufactured as follows, for example. An alignment film is formed on a substrate, and a coating liquid containing a polymerizable liquid crystal compound is coated on the alignment film. 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. 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, and after cutting each member to a predetermined shape, joining You may also do it.

And the circular 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.

<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 electro luminescence display (hereinafter also referred to as an 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 device using electronic ink or electrophoretic element), plasma display device, projection display device (e.g., grating light valve (also called GLV) display device, digital micromirror device (DMD)) Display device), a piezoelectric ceramic display, and the like. The liquid crystal display device includes any one of a transmissive liquid crystal display device and a transflective liquid crystal display device. These display devices may be display devices for displaying two-dimensional images, or three-dimensional display devices for displaying three-dimensional images. In particular, the circular polarizing plate can be effectively used for an organic EL display device or an inorganic EL display device.

In FIGS. 3A and 3B, 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. Layer structure).

EXAMPLE

(1) measuring method of film thickness

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

(2) Measurement method of moisture permeability

The moisture permeability of the protective film was measured in accordance with JIS Z0208 moisture permeability test (Cup method). Measurement conditions were performed at a temperature of 40 ° C. and a relative humidity of 90%.

(3) Measuring method of phase difference value

It measured using the phase difference measuring apparatus KOBRA-PR (made by Oji Geisokukiki Co., Ltd.).

(4) Measuring method of moisture content of polarizing plate

The moisture content of the polarizing plate was computed according to the dry weight method. The weight (W1) of the polarizing plate and the weight (W0) of the polarizing plate before drying were measured, respectively, when drying at 105 degreeC for 2 hours. These values were substituted into the following formula, and the moisture content of the polarizing plate was computed.

  Moisture content (%) of polarizing plate = {(W0-W1) ÷ W0} x 100

<Production of Polarizer A>

Polyvinyl alcohol film (average degree of polymerization of about 2400, saponification degree of 99.9 mol% or more) of 20 μm thick was uniaxially stretched by about 4 times by dry stretching and immersed in pure water at 40 ° C. for 40 seconds while maintaining a further tension state. 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 polarizing film having a thickness of 8 μm was obtained.

<Making Polarizer B>

A polyvinyl alcohol was produced in the same manner as in the preparation of the polarizer (A), except that a polyvinyl alcohol film (average degree of polymerization of about 2400 and a degree of saponification of 99.9 mol% or more) having a thickness of 30 µm was used instead of the polyvinyl alcohol film having a thickness of 20 µm. The polarizer (B) of thickness 13 micrometers in which iodine adsorption-oriented was obtained to the film.

<Production of Polarizer C>

A polyvinyl alcohol was produced in the same manner as in the preparation of the polarizer (A) except that a polyvinyl alcohol film (average degree of polymerization of about 2400 and a degree of saponification of 99.9 mol% or more) having a thickness of 60 µm was used instead of the polyvinyl alcohol film having a thickness of 20 µm. The polarizer (C) of thickness 23 micrometers in which iodine was adsorption-oriented on the film was obtained.

<Making Polarizer D>

A polyvinyl alcohol was produced in the same manner as in the preparation of the polarizer (A), except that a polyvinyl alcohol film (average degree of polymerization of about 2400 and a degree of saponification of 99.9 mol% or more) having a thickness of 75 µm was used instead of the polyvinyl alcohol film having a thickness of 20 µm. The polarizer (D) of 28 micrometers in thickness which iodine adsorb | suction-aligned to the film was obtained.

<Preparation of Water-based Adhesive>

3 parts by weight of a carboxyl group-modified polyvinyl alcohol (trade name "KL-318" obtained from Kuraray Co., Ltd.) was dissolved with respect to 100 parts by weight of water, and a polyamide epoxy clock additive [Daokaga] which is a water-soluble epoxy resin in the aqueous solution. 1.5 parts by weight of the trade name "Sumirez resin (registered trademark) 650 (30)" obtained from Gaku Kogyo Co., Ltd. and a solid content concentration of 30% by weight] was added to prepare an aqueous adhesive.

<Preparation of an adhesive layer>

Adhesive layer A: The acrylic adhesive layer whose thickness is 25 micrometers formed on the peeling film was prepared.

Adhesive layer B: The acrylic adhesive layer whose thickness is 5 micrometers formed on the peeling film was prepared.

Adhesive layer C: The acrylic adhesive layer whose thickness is 20 micrometers formed on the peeling film was prepared.

<Preparation of protective film>

The following protective film was prepared.

Protective film A: Norbornene-type resin film of 20 micrometers in thickness.

Protective film B: The norbornene-type resin film in which a hard-coat layer was formed in one side, and the thickness of protective film B were 52 micrometers.

Protective film C: The thickness of the TAC film and protective film C in which the hard-coat layer was formed in one side was 31 micrometers.

Protective film D: The thickness of the norbornene-type resin film in which the hard-coat layer was formed on one surface, and the protective film D was 29 micrometers.

Protective film E: TAC film of 40 micrometers in thickness.

Protective film F: The norbornene-type resin film of thickness 13micrometer.

Protective film G: TAC film of 25 micrometers in thickness.

Protective film H: TAC film of 20 micrometers in thickness.

<Production of phase difference film>

5 parts (weight average molecular weight: 30000) and 95 parts of cyclopentanone (solvent) of the photo-alignment material of the following structure were mixed as a component, and the obtained mixture was stirred at 80 degreeC for 1 hour, and the composition for orientation film formation was obtained.

2-dimethylamino- which is 1.0 parts of leveling agents (F-556; DIC Corporation make) and a polymerization initiator with respect to the mixture which mixed the polymeric liquid crystal compound A and polymeric liquid crystal compound B shown below at the mass ratio of 90:10. 6 parts of 2-benzyl-1- (4-morpholinophenyl) butan-1-one ("Igacure 369 (Irg 369)", BASF Japan make) were added.

Furthermore, N-methyl-2-pyrrolidone (NMP) was added so that solid content concentration might be 13%, and it stirred at 80 degreeC for 1 hour, and obtained the composition for phase difference layer formation.

The polymerizable liquid crystal compound A was produced by the method described in JP 2010-31223 A. 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 cyclic polyolefin pin film [The brand name "ZF-14-50" by the Nippon-Xeon Corporation]. The composition for oriented film formation was apply | coated with the bar coater on the surface which corona-treated. The coating film of the composition for oriented film formation was dried at 80 degreeC for 1 minute. Using a polarizing UV irradiation device (trade name "SPOT CURE SP-9" of Ushio Denki Co., Ltd.), accumulated light quantity at a wavelength of 313 nm: 100 mJ / m <2>, polarized UV was irradiated to a coating film at 45 degrees of axial angles, , An alignment film was obtained.

Subsequently, the composition for retardation layer formation was apply | coated using the bar coater on the orientation film, and it dried at 120 degreeC for 1 minute. Irradiating ultraviolet light (integrated light quantity in wavelength 365nm under nitrogen atmosphere: 500 mJ / m <2>) using a high pressure mercury lamp [trade name: "Unicure VB-15201BY-A") to the coating film after drying. By polymerizing the polymerizable liquid crystal compound. Thus, the laminated body which consists of a layer which the base material, the oriented film, and the polymeric liquid crystal compound hardened | cured was obtained.

In-plane retardation value [Re ((lambda))] of the layer which the polymeric liquid crystal compound manufactured by the said method hardened | cured is after measuring a laminated body to glass via an adhesive, and peeling off the cyclic polyolefin film which is a base material, It was measured by Ojiisokigiki Co., Ltd. brand name "KOBRA-WPR". The measurement result of the retardation value [Re ((lambda))] in each wavelength is Re (450) = 121nm, Re (550) = 142nm, Re (650) = 146nm, and the polymeric liquid crystal compound hardened | cured The layer was to function as a retardation film. Based on these values, Re (450) / Re (550) = 0.85 and Re (650) / Re (550) = 1.03 were calculated.

<Preparation of front panel>

The glass plate with a thickness of 0.4 mm manufactured by Corning Corporation was prepared.

Example 1

On one side of the polarizer A, the protective film B was bonded through the said water-based adhesive agent, and the protective film A was bonded to the other side through the said water-based adhesive agent. The drying process was performed and the polarizing plate was produced. The moisture content of the polarizing plate was 1.11%.

In the polarizing plate, the adhesive layer B was laminated | stacked on the protective film A, and the peeling film was peeled off. On the exposed adhesive layer B, the said laminated body was laminated | stacked so that the layer which hardened the polymeric liquid crystal compound might become a bonding surface, and then the base material was peeled off. Thus, the circularly polarizing plate which consists of protective film B / polarizer A / protective film A / adhesive layer B / retardation film was produced.

EXAMPLES 2-4, COMPARATIVE EXAMPLES 1-2

The circularly polarizing plate was produced similarly except having changed the moisture content of a polarizer, a protective film, and a polarizing plate as shown in Table 1 below. In addition, the moisture content of the polarizing plate was adjusted by adjusting drying temperature and drying time.

<Heat test>

In the produced circular polarizing plate, the adhesive layer A was laminated | stacked on the retardation film. The peeling film was peeled off, and the circular polarizing plate was laminated | stacked on the glass plate through the exposed adhesive layer A. In addition, in the polarizing plate, the adhesive layer C was laminated | stacked on the protective film (1st protective film) on the opposite side to the retardation film side. The peeling film was peeled off, and the front plate was laminated | stacked on the exposed adhesive layer C. Thus, the sample for evaluation which consists of a glass plate (front plate) / adhesive layer C / original polarizing plate / adhesive layer A / glass plate was produced.

The sample for evaluation was put into an oven of 85 degreeC for 400 hours. The in-plane retardation value of the circularly polarizing plate before and after introduction was measured, and the difference (ΔRe) was calculated. Moreover, the retardation value was measured in the center part in surface inside of a circularly polarizing plate. The wavelength which measured in-plane phase difference value was 547 nm. The above results are shown in Table 1. The circularly polarizing plate of the Example had little fall of a phase difference value, and there was no coloring in the reflected light after a heat test. On the other hand, in the circularly polarizing plate of the comparative example, the fall of the phase difference value was large, and the reflected light was red.

According to this invention, since the circularly polarizing plate provided with the retardation film containing the layer which hardened | cured the liquid crystal compound WHEREIN: Since the cover glass is bonded in the high temperature environment after bonding, since the color change of the reflected light from an initial stage can be suppressed, useful.

1: polarizer
2: retardation film
3: organic EL display element
4: front panel
10: polarizer
11: first protective film
12: second protective film
13, 14, 16: pressure-sensitive adhesive layer
15: adhesive layer
20, 21: layer which the polymerizable liquid crystal compound cured

Claims (4)

A retardation film including a polarizing plate having a first protective film laminated on one side of the polarizer, a second protective film laminated on the other side of the polarizer, and a layer cured by the polymerizable liquid crystal compound,
The circular polarizing plate which satisfy | fills at least one among the following conditions 1 and 2.
Condition 1: Formula (1) is satisfied when the water vapor transmission rate of the said 1st protective film is set to x (g / m <2> * 24hr), and the water vapor transmission rate of the said 2nd protective film is set to y (g / m <2> * 24hr). do.
1 / x + 1 / y≥0.0030 (1)
Condition 2: The moisture content of the said polarizing plate is 3.00% or less. The circularly polarizing plate according to claim 1, wherein both of conditions 1 and 2 are satisfied. The circularly polarizing plate according to claim 1 or 2, further comprising a front plate on a side opposite to the side on which the retardation film is laminated in the polarizing plate. The circular polarizing plate of any one of Claims 1-3 whose thickness of the said polarizer is 13 micrometers or less.

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