JP2003315556A - Polarizing plate with optical compensation function and liquid crystal display device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polarizing plate which has an optical compensation function and which is thin and has excellent productivity, and a liquid crystal display device using the same. <P>SOLUTION: The polarizing plate with the optical compensation function comprises a polarizing layer and an optical compensation layer. The optical compensation layer includes an optical compensation A-layer containing a stretched polymer film and an optical compensation B-layer containing a cholesteric liquid crystal layer. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polarizing plate having an optical compensation function and a liquid crystal display device using the same.

[0002]

2. Description of the Related Art In order to compensate for the birefringence of a liquid crystal cell and obtain a liquid crystal display device which exhibits excellent quality display in all directions, the principal refractive indices (nx, ny) in the in-plane two directions and in the thickness direction are used. , N
An optical compensation layer with controlled z) is required. Especially, VA (Ver
type and OCB (Optically Compensated Ben)
In the d) type liquid crystal display device, the main refractive indices in three directions are nx>ny> n.
An optical compensation layer for z is required.

Conventionally, as the optical compensation layer, an optical compensation layer in which two or more stretched polymer films are laminated is used. For example, there is an optical compensation layer in which two uniaxially stretched polymer films are prepared and laminated so that the directions of the slow axes in the planes of the two are orthogonal to each other. However, since the stretched polymer film has a thickness of about 1 mm, the optical compensation layer in which two or more stretched polymer films are laminated has a large thickness, and as a result, the thickness of the entire liquid crystal display device increases. was there.

[0004]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a polarizing plate having an optical compensation function, in which an optical compensation layer having a thickness smaller than that of an optical compensation layer in which two or more stretched polymer films are laminated is laminated. And

[0005]

According to the present invention, there is provided a polarizing plate having an optical compensation function, comprising a polarizing layer and an optical compensation layer, wherein the optical compensation layer comprises a stretched polymer film. , And optical compensation B containing a cholesteric liquid crystal layer
A polarizing plate having an optical compensation function including a layer is provided.

Further, according to the present invention, there is provided a liquid crystal display device comprising a liquid crystal cell and a polarizing plate with an optical compensation function of the present invention, wherein the polarizing plate is arranged on at least one surface of the liquid crystal cell.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The thickness of a cholesteric liquid crystal layer is
Usually, it is 50 μm or less, for example, 10 μm. Therefore, compared to laminating two layers of stretched polymer film (usually about 1 mm / layer), laminating an optical compensation A layer containing a stretched polymer film and an optical compensation B layer containing a cholesteric liquid crystal layer results in a laminate of The thickness can be reduced. Further, even if two or more optical compensation B layers are laminated in order to further enhance the optical compensation function, the thickness of one sheet is thin, so that the thickness can be made smaller than that of a laminate of two stretched polymer films.

The polarizing plate with an optical compensation function of the present invention includes an optical compensation A layer and an optical compensation B layer, but the order of stacking them may be any order. For example, a polarizing layer,
The optical compensation A layer and the optical compensation B layer may be laminated in this order, or the polarizing layer, the optical compensation B layer and the optical compensation A layer may be laminated in this order. Furthermore, two or more layers of either the optical compensation A layer or the optical compensation B layer may be included. At that time, the stacking order may be any order. For example, a polarizing layer, an optical compensation B layer, an optical compensation A layer and an optical compensation B layer may be laminated in this order.

It is preferable that the absorption axis of the polarizing layer and the slow axis of the optical compensation A layer form an angle of not less than 85 ° and not more than 95 °. When a polarizing plate with an optical compensation function arranged so as to form this angle is used in a liquid crystal cell such as VA or OCB, birefringence of those cells is efficiently compensated, and a liquid crystal using the polarizing plate with an optical compensation function is used. The viewing angle of the display device can be expanded. Further, the angle formed by the absorption axis direction of the polarizing layer and the slow axis direction of the optical compensation A layer is more preferably 86 ° or more and 94 ° or less, and further preferably 87 ° or more and 93 ° or less.

In the present invention, the polymer film contained in the optical compensation A layer is formed by a stretched polymer film or a liquid crystal film obtained by stretching an unstretched polymer film by an appropriate method. Most preferably, the liquid crystal film is made of nematic liquid crystal.

The unstretched polymer film is not particularly limited, and a material that can impart optical anisotropy by stretching the film and is excellent in birefringence controllability, transparency and heat resistance is preferable. The unstretched polymer film may be used alone or as a mixture of two or more kinds. For example, polyolefin (polyethylene, polypropylene, etc.), polynorbornene-based polymer, polyester, polyvinyl chloride, polystyrene, polyacrylonitrile, polysulfone, polyarylate, polyvinyl alcohol, polymethacrylic acid ester, polyacrylic acid ester, cellulose ester and their copolymers. A polymer or the like can be used.

Further, the polymer film described in JP 2001-343529 A (WO 01/37007) may also be mentioned. Examples of the polymer material include a thermoplastic resin having a substituted or unsubstituted imide group in its side chain and a resin composition containing a thermoplastic resin having a substituted or unsubstituted phenyl group and a cyano group in its side chain. Examples of the resin composition that can be used include an alternating copolymer of isobutene and N-methylenemaleimide and an acrylonitrile / styrene copolymer.

The method for producing the unstretched polymer film is not particularly limited, and a usual method can be used. The extrusion method or the cast film forming method is preferable because unevenness of birefringence of the polymer film after stretching can be reduced. The unstretched polymer film is, for example, 3 mm or less, preferably 1
Those having a thickness of μm to 1 mm, particularly preferably 5 to 500 μm are used.

The stretching method of the unstretched polymer film is not particularly limited, but a usual method can be used. For example, tenter transverse stretching and biaxial stretching may be mentioned. In the biaxial stretching, the stretching ratio in the major axis direction is preferably smaller than the stretching ratio in the minor axis direction. Further, the biaxial stretching can be performed by any of simultaneous biaxial stretching by all tenter method and sequential biaxial stretching by roll-tenter method.

The stretch ratio of the unstretched polymer film is
Although it depends on the stretching method, it is usually stretched by 101 to 250% with respect to the length of the unstretched polymer film. The stretching ratio of the unstretched polymer film is preferably 101 to 200% with respect to the length of the unstretched polymer film.

The temperature at which the unstretched polymer film is stretched is appropriately selected according to the glass transition point (Tg) of the unstretched polymer film used, the type of additives in the unstretched polymer film, and the like. It The temperature at which the unstretched polymer film is stretched is, for example, 80 to 250 ° C, preferably 120 to 220 ° C, and particularly preferably 140 to 200 ° C.
Is. In particular, the temperature at which the unstretched polymer film is stretched is preferably around Tg of the unstretched polymer film to be stretched or higher than Tg.

The thickness of the stretched polymer film can be appropriately determined according to the size of the screen of the target image display device. The stretched polymer film has a thickness of, for example, 1 mm or less, preferably 1 to 500 μm, and particularly preferably 5 to 300 μm.

Optical Compensation A Containing the Stretched Polymer Film
The layers preferably satisfy the following formulas (I) and (II). 20 (nm) ≤ Re ≤ 300 (nm) (I) 1.2 ≤ Rth / Re (II)

In the above equation, Re (phase difference value in normal direction) = (nx-ny) .multidot.d Rth (phase difference value in thickness direction) = (nx-nz) .multidot.d.

Further, in the above formula, nx, ny and nz respectively represent the refractive indices in the X-axis, Y-axis and Z-axis directions in the optical compensation A layer. The X-axis is an axial direction that exhibits the maximum refractive index in the plane of the optical compensation A layer, the Y-axis is an axial direction that is perpendicular to the X-axis in the plane, and the Z-axis is , Shows a thickness direction perpendicular to the X-axis and the Y-axis. d represents the thickness of the optical compensation A layer.

Re represented by the formula (I) is preferably 25≤.
Re ≦ 250, more preferably 30 ≦ Re ≦ 20
It is 0. Further, Rth / Re is preferably 1.5 ≦
Rth / Re, more preferably 2 ≦ Rth / Re
Is.

The optical compensation B layer can be manufactured by applying a cholesteric liquid crystal on the alignment layer, orienting it, and fixing the alignment state to form the cholesteric liquid crystal layer.

The cholesteric liquid crystal layer is not particularly limited, and those manufactured by a method according to the conventional liquid crystal alignment treatment can be used. For example, first, a cholesteric liquid crystal polymer and a chiral agent are applied on the alignment layer of the substrate. The coating layer is heated above the glass transition temperature and below the isotropic phase transition temperature to orient the liquid crystal polymer molecules in the coating layer. Then, when the coating layer is cooled below the glass transition temperature, the cholesteric liquid crystal layer in which the orientation of the liquid crystal polymer molecules is fixed can be formed on the substrate. Further, a photocrosslinkable liquid crystal monomer and a chiral agent are coated on the alignment layer, and the coating layer is heated at a temperature not lower than the glass transition temperature and lower than the isotropic phase transition temperature, as described above. Align the liquid crystal monomer therein. Examples thereof include a method of subjecting the liquid crystal monomer to light treatment to crosslink the liquid crystal monomer to form a cholesteric liquid crystal layer on a substrate.

In order to control the selective reflection wavelength band within the above range, the cholesteric liquid crystal layer preferably contains a chiral agent. The chiral agent in the present invention,
For example, it is a compound having a function of aligning a liquid crystal monomer or a liquid crystal polymer described below so as to have a cholesteric structure.

The type of the chiral agent is not particularly limited as long as it can orient the constituent molecules of the cholesteric layer into the cholesteric structure as described above.
For example, the chiral agent described below is preferable.

Among these chiral agents, the twisting power is preferably 1 × 10 ⁻⁶ nm ⁻¹ · (wt%) ⁻¹ or more, more preferably 1 × 10 ⁻⁵ nm ⁻¹ · ( wt%) ^-1 or more, more preferably 1 × 10 ^-5 to 1 × 10 ^-2 nm ^-1 (wt%)
^{-1 in} the range, particularly preferably 1 × 10 ^-4 ~ 1 × 10 ^-3
The range is nm ⁻¹ · (wt%) ⁻¹ . If a chiral agent having such a twisting power is used, for example, the helical pitch of the formed cholesteric liquid crystal layer can be controlled within the range described below, and thus it is sufficient to control the selective reflection wavelength band within the range. It becomes possible.

The term "twisting force" generally refers to the ability to give a twist to a liquid crystal material such as a liquid crystal monomer or a liquid crystal polymer, which will be described later, and to align it in a spiral shape.
It can be expressed by the following formula. Torsional force = 1 / [Cholesteric pitch (nm) x Chiral agent weight ratio (wt
%)]

In the above formula, the weight ratio of the chiral agent is, for example, the ratio (weight ratio) of the chiral agent in the mixture containing the liquid crystal monomer or liquid crystal polymer and the chiral agent.
Is expressed by the following formula. Chiral agent weight ratio (wt%) = [X / (X + Y)] × 1
00 X: weight of chiral agent Y: weight of liquid crystal monomer or weight of liquid crystal polymer

First, a method for producing using a cholesteric liquid crystal polymer will be exemplified below.

As the cholesteric liquid crystal polymer, known ones can be appropriately used. Examples of the cholesteric liquid crystal polymer include cyanobiphenyl-based, cyanophenylcyclohexane-based, cyanophenylester-based, benzoic acid phenylester-based, phenylpyrimidine-based and mixtures thereof. Further, it is preferable to adjust the ratio of the cholesteric liquid crystal polymer and the chiral agent, and particularly to adjust the selective reflection wavelength region to 350 nm or less. Further, as the cholesteric liquid crystal polymer of the present invention, the polymer described in Japanese Patent No. 2660601 (Nippon Oil Co., Ltd.) can also be preferably used.

First, the cholesteric liquid crystal polymer is applied onto the alignment layer. The coating method is not particularly limited, and a conventionally known method can be used. For example, a method of applying a solution of the cholesteric liquid crystal polymer, a method of applying a melt of the cholesteric liquid crystal polymer, and the like can be mentioned. Above all, a method of applying a solution of a cholesteric liquid crystal polymer is preferable.

The polymer concentration in the cholesteric liquid crystal polymer solution is not particularly limited, but may be, for example, 5 to 50 of the cholesteric liquid crystal polymer with respect to the solvent.
% By weight, preferably 7-40% by weight, more preferably 1
It is 0 to 30% by weight.

The type of the chiral agent is not particularly limited as long as it can align the liquid crystal polymer of the cholesteric layer into the cholesteric structure as described above, but for example, the chiral agent described later is preferable. These chiral agents may be used alone or in combination of two or more.

The addition ratio of the chiral agent is appropriately determined depending on, for example, the desired selective reflection wavelength band, but the addition ratio to the liquid crystal polymer is in the range of 5 to 23% by weight, preferably 10 to It is in the range of 20% by weight.
As described above, by controlling the addition ratio of the liquid crystal polymer and the chiral agent in this way, the selected wavelength band of the optical compensation B layer to be formed can be set within the above range. Ratio of chiral agent to liquid crystal polymer is 5% by weight
If it is smaller than this, it becomes difficult to control the selective reflection wavelength band of the formed optical compensation B layer to the low wavelength side. Further, when the ratio is more than 23% by weight, the temperature range in which the liquid crystal polymer is cholesteric aligned, that is, the temperature range in which the liquid crystal polymer is in the liquid crystal phase is narrowed, so that the temperature control in the alignment step described later is strictly performed. Becomes necessary, and manufacturing becomes difficult.

The solvent for the cholesteric liquid crystal polymer solution is not particularly limited and may be any solvent as long as it can dissolve the cholesteric liquid crystal polymer, and can be appropriately determined according to the type of the cholesteric liquid crystal polymer. Specific examples include, for example, chloroform, dichloromethane,
Halogenated hydrocarbons such as carbon tetrachloride, dichloroethane, tetrachloroethane, trichloroethylene, tetrachloroethylene, chlorobenzene, orthodichlorobenzene; phenols such as phenol and valachlorophenol; benzene, toluene, xylene, methoxybenzene, 1,2-dimethoxybenzene Aromatic hydrocarbons such as; acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, cyclopentanone, 2-pyrrolidone, N-methyl-2-pyrrolidone, and other ketone solvents; ethyl acetate, butyl acetate, and other ester solvents; t-
Butyl alcohol, glycerin, ethylene glycol,
Triethylene glycol, ethylene glycol monomethyl ether, diethylene glycol dimethyl ether,
Propylene glycol, dipropylene glycol, 2-
Alcohol solvent such as methyl-2,4-pentanediol; Amide solvent such as dimethylformamide and dimethylacetamide; Nitrile solvent such as acetonitrile and butyronitrile; Ether solvent such as diethyl ether, dibutyl ether and tetrahydrofuran Or carbon disulfide, ethyl cellosolve, butyl cellosolve and the like. These solvents may be used alone or in combination of two or more.

The cholesteric liquid crystal polymer solution is
For example, various additives such as stabilizers, plasticizers and metals may be further compounded, if necessary. Further, the cholesteric liquid crystal polymer solution may contain other different resins, for example, within a range in which the orientation of the cholesteric liquid crystal polymer is not significantly deteriorated. Examples of the other resin include various general-purpose resins, engineering plastics, thermoplastic resins, and thermosetting resins.

Examples of the general-purpose resin include polyethylene (PE), polypropylene (PP), polystyrene (PS), polymethylmethacrylate (PMMA), A
Examples include BS resin and AS resin. Examples of the engineering plastic include polyacetate (POM), polycarbonate (PC), polyamide (PA: nylon), polyethylene terephthalate (PET), and polybutylene terephthalate (PB).
T) and the like. Examples of the thermoplastic resin include polyphenylene sulfide (PPS), polyether sulfone (PES), polyketone (PK), polyimide (PI), polycyclohexanedimethanol terephthalate (PCT), polyarylate (PAR), and liquid crystal polymer. (LCP) and the like. Examples of the thermosetting resin include epoxy resin and phenol novolac resin.

Thus, when the other resin or the like is blended in the polymer solution, the blending amount is, for example, 0 to 50 relative to the cholesteric liquid crystal polymer.
% By weight, preferably 0 to 30% by weight.

Next, the cholesteric liquid crystal polymer solution is applied onto the alignment layer to form a spreading layer.

Examples of the coating method of the cholesteric liquid crystal polymer solution include spin coating method, roll coating method, flow coating method, printing method, dip coating method, casting film forming method, bar coating method, gravure printing method, etc. Can be given. Further, in coating, a polymer layer superposing method can be adopted as necessary.

The alignment layer is not particularly limited as long as it can align the cholesteric liquid crystal polymer. For example, various plastic films or plastic sheets whose surfaces are rubbed with rayon can be used. Further, on the surface of a substrate such as a metal substrate made of aluminum, copper, iron, etc., a ceramic substrate, a glass substrate, or the like, a plastic film or sheet as described above is arranged,
It is also possible to use an inorganic compound such as one having an SiO ₂ oblique vapor deposition film formed on the surface. Further, a layer having microgrooves formed on the surface or an organic compound (eg, ω-tricosanoic acid, dioctadecylmethylammonium chlorite, methyl stearate) is accumulated by the Langmuir-Blodgett method (LB film). An alignment layer may be formed by using the above. Further, as an alignment layer, JP-A-3-9325 (Patent No. 2631015) is used.
No.) stretched polymer film and a plastic film or plastic sheet to which an electric field is applied,
It is also possible to use a material to which a magnetic field is applied or a material in which an alignment layer having an alignment function generated by light irradiation is arranged.

The alignment layer is not particularly limited as long as it has a function of aligning the cholesteric liquid crystal polymer, and the surface of the protective layer of the polarizing layer may be rubbed to serve as the protective layer and the alignment layer. .

Then, the spreading layer of the cholesteric liquid crystal polymer is subjected to heat treatment to align the cholesteric liquid crystal polymer. The temperature condition of the heat treatment is, for example, the type of the cholesteric liquid crystal polymer,
Specifically, it can be appropriately determined according to the temperature at which the cholesteric liquid crystal polymer exhibits liquid crystallinity, but it is necessary to set the temperature above the glass transition point of the cholesteric liquid crystal polymer and below the isotropic point. The method using the cholesteric liquid crystal polymer is more preferable in terms of work since it does not require a cross-linking treatment after alignment of liquid crystal molecules.

As described above, the cholesteric liquid crystal layer is preferably a polymer obtained by polymerizing or crosslinking a photocrosslinkable liquid crystal monomer. With this configuration,
As will be described later, since the monomer exhibits liquid crystallinity, it can be oriented by taking a cholesteric structure, and the orientation can be fixed by further polymerizing the monomers. Then, a liquid crystal monomer is used, but by the fixing, the polymerized polymer becomes non-liquid crystalline. Therefore, the formed cholesteric liquid crystal layer is
Although it has a cholesteric structure like a cholesteric liquid crystal phase, since it is not composed of liquid crystal molecules, it does not change to a liquid crystal phase, a glass phase, or a crystal phase due to temperature change, which is peculiar to liquid crystal molecules. Therefore, the cholesteric structure becomes a cholesteric liquid crystal layer which is not affected by temperature change and has extremely excellent stability, and can be said to be particularly useful as a retardation film for optical compensation, for example. Unless otherwise specified, the cholesteric liquid crystal layer can be formed in the same manner as in the case of using the cholesteric liquid crystal polymer.

The liquid crystal monomer is preferably a monomer represented by the chemical formula (1) described later. Such a liquid crystal monomer is generally a nematic liquid crystal monomer, but in the present invention, for example, a twist is imparted by the chiral agent, and finally, a cholesteric structure is formed. Further, in the cholesteric liquid crystal layer, it is necessary to polymerize or crosslink between the monomers in order to fix the alignment. Therefore, the monomer preferably contains at least one of a polymerizable monomer and a crosslinkable monomer.

The cholesteric liquid crystal layer preferably further contains at least one of a polymerizing agent and a cross-linking agent. For example, substances such as an ultraviolet curing agent, a photo-curing agent and a heat curing agent can be used.

The proportion of the liquid crystal monomer in the cholesteric liquid crystal layer is preferably in the range of 75 to 95% by weight, more preferably 80 to 90% by weight. Further, the ratio of the chiral agent to the liquid crystal monomer is preferably in the range of 5 to 23% by weight, more preferably 10 to 20% by weight. Further, the ratio of the cross-linking agent or the polymerizing agent to the liquid crystal monomer,
The range is preferably 0.1 to 10% by weight, more preferably 0.5 to 8% by weight, and particularly preferably 1 to 5% by weight.

The optical compensation B layer of the present invention may be formed of, for example, only the cholesteric liquid crystal layer as described above, but is a laminated body in which a substrate is further included and the cholesteric liquid crystal layer is laminated on the substrate. It may be.

Next, the method for producing the optical compensation B layer of the present invention contains a liquid crystal monomer, the above chiral agent, and at least one of a polymerizing agent and a crosslinking agent, and the ratio of the chiral agent to the above liquid crystal monomer is set. A step of developing a coating liquid in the range of 5 to 23% by weight on the alignment layer to form a development layer, and subjecting the development layer to heat treatment so that the liquid crystal monomer has a cholesteric structure-oriented orientation. Process of applying
And a production method including a step of subjecting the spreading layer to at least one of a polymerization treatment and a crosslinking treatment in order to fix the orientation of the liquid crystal monomer to form a cholesteric liquid crystal layer of a non-liquid crystal polymer. According to such a manufacturing method, the optical compensation B layer of the present invention having the above-mentioned selective reflection wavelength band can be manufactured. By controlling the compounding ratio of the liquid crystal monomer and the chiral agent in this manner, the selective reflection wavelength band is 100 nm to 320 nm.
Can be controlled in the range of.

An example of the method for producing the optical compensation B layer of the present invention will be specifically described below. First, a coating liquid containing the liquid crystal monomer, the chiral agent, and at least one of the cross-linking agent and the polymerizing agent is prepared.

The liquid crystal monomer is preferably, for example, a nematic liquid crystal monomer, and specific examples thereof include a monomer represented by the following formula (1). These liquid crystal monomers may be used alone or in combination of two or more.

[0052]

[Chemical 1]

In the above formula (1), A ¹ and A ² are
Each represents a polymerizable group and may be the same or different. Further, ^one of A ¹ and A ² may be hydrogen. X is a single bond, -O-, -S-, -C, respectively.
= N-, -O-CO-, -CO-O-, -O-CO-O
-, -CO-NR-, -NR-CO-, -NR-, -O
-CO-NR -, - NR- CO-O -, - CH 2 -O-
Or -NR-CO-NR, wherein R in the above X is
Represents H or C ₁ -C ₄ alkyl, and M represents a mesogen group.

In the above formula (1), X may be the same or different, but it is preferable that they are the same.

Among the monomers of the above formula (1), A
It is preferable that each of ^2's is ortho to A ¹ .

It is preferable that A ¹ and A ² are each independently represented by the following formula Z--X-(Sp) _n ... (2), and A ¹ and A ² are the same group. Preferably there is.

In the above formula (2), Z represents a crosslinkable group, X is the same as in the above formula (1), and Sp is 1 to 30.
Represents a spacer composed of a linear or branched alkyl group having C atoms, and n represents 0 or 1. The carbon chain in Sp may be interrupted by, for example, oxygen in an ether functional group, sulfur in a thioether functional group, a non-adjacent imino group, or a C ₁ -C ₄ alkylimino group.

In the above formula (2), Z is preferably any of the atomic groups represented by the following formula. In the following formula, R is, for example, methyl, ethyl, n-
Propyl, i-propyl, n-butyl, i-butyl, t
Group such as -butyl.

[0059]

[Chemical 2]

In the above formula (2), Sp is preferably one of the atomic groups represented by the following formula, and in the formula below, m is 1 to 3 and p is 1 to 12. Is preferred.

[0061]

[Chemical 3]

In the above formula (1), M is preferably represented by the following formula (3), and in the following (3), X is the same as X in the above formula (1). Q
Represents, for example, a substituted or unsubstituted alkylene or aromatic hydrocarbon atomic group, and may be, for example, a substituted or unsubstituted linear or branched C _{1 to} C ₁₂ alkylene.

[0063]

[Chemical 4]

When Q is the aromatic hydrocarbon atomic group, for example, an atomic group represented by the following formula or a substituted analog thereof is preferable.

[0065]

[Chemical 5]

The substituted analog of the aromatic hydrocarbon atomic group represented by the above formula is, for example, 1 to 1 per aromatic ring.
It may have 4 substituents and may have 1 or 2 substituents per aromatic ring or group. The substituents may be the same or different. Examples of the substituent include C ₁ -C ₄ alkyl,
Halogen such as nitro, F, Cl, Br, I, phenyl,
C ₁ -C ₄ alkoxy, and the like.

Specific examples of the liquid crystal monomer include monomers represented by the following formulas (4) to (19).

[0068]

[Chemical 6]

The temperature range in which the liquid crystal monomer exhibits liquid crystallinity varies depending on its type, but is, for example, 40 to 120.
It is preferably in the range of ℃, more preferably 50 ~
It is in the range of 100 ° C, particularly preferably in the range of 60 to 90 ° C.

As described above, the chiral agent is not particularly limited as long as it is twisted to the liquid crystal monomer to align it so as to have a cholesteric structure, but it is a polymerizable chiral agent. Preferably, the above-mentioned ones can be used. These chiral agents may be used alone or in combination of two or more.

Specifically, as the polymerizable chiral agent, for example, chiral compounds represented by the following general formulas (20) to (23) can be used. _{^{(Z-X 5) n Ch}} (20) (Z-X 2 -Sp-X 5) n Ch (21) (P 1 -X 5) n Ch (22) (Z-X 2 -Sp-X 3 - M-X ⁴ ) _n Ch (23)

In each of the above formulas, Z is the same as the above formula (2), Sp is the same as the above formula (2),
X ^2, X ³ and X ^4, independently of one another, a chemical single bond, -O -, - S -, - O-CO -, - CO-O -, -
O-CO-O-, -CO-NR-, -NR-CO-,-
O-CO-NR-, -NR-CO-O-, -NR-CO
Represents —NR—, and R represents H, C ₁ -C ₄ alkyl. X ⁵ is a chemical single bond, —O—, —S—, —
O-CO-, -CO-O-, -O-CO-O-, -CO
-NR-, -NR-CO-, -O-CO-NR-, -N
R-CO-O -, - NR-CO-NR, -CH 2 O-,
_{-O-CH 2 -, - CH} = N -, - N = CH- or -
Represents N≡N−. R is the same manner as described above represents H, C ₁ -C ₄ alkyl. M represents a mesogen group as described above,
P ¹ represents hydrogen, a C _{1 to} C ₃₀ alkyl group substituted by _{1 to} 3 C _{1 to} C ₆ alkyl, a C ₁ to ₃₀ acyl group or a C _{3 to} C ₈ cycloalkyl group, and n is It is an integer of 1 to 6. Ch represents an n-valent chiral group. Equation (2)
In 3), at least one of X ³ and X ⁴ is —O—CO—O—, —O—CO—NR—, or —NR—.
It is preferably CO-O- or -NR-CO-NR-. Further, in the above formula (22), when P ¹ is an alkyl group, an acyl group or a cycloalkyl group, for example, the carbon chain thereof is oxygen in the ether functional group, sulfur in the thioether functional group, a non-adjacent imino group or it may be interrupted by C ₁ -C ₄ alkylimino groups.

Examples of the chiral group of Ch include, for example,
An atomic group represented by the following formula can be given.

[0074]

[Chemical 7]

[0075]

[Chemical 8]

In the above atomic group, L is C ₁ -C ₄ alkyl, C ₁ -C ₄ alkoxy, halogen, COOR, OC.
OR, CONHR or NHCOR, wherein R represents C ₁ -C ₄ alkyl. The terminal of the atomic group represented by the above formula represents a bond with an adjacent group.

Among the above atomic groups, the atomic group represented by the following formula is particularly preferable.

[0078]

[Chemical 9]

In the chiral compound represented by the above (21) or (23), for example, n is 2, Z is H ₂ C =
CH- is represented, and Ch is preferably an atomic group represented by the following formula.

[0080]

[Chemical 10]

Specific examples of the chiral compound include compounds represented by the following formulas (24) to (44). These chiral compounds have a twisting power of 1 × 10 ^-6 nm ^-1 · (wt%) ^-1 or more.

[0082]

[Chemical 11]

In addition to the chiral compounds as described above, for example, RE-A 4342280 and German patent applications 19520660.6 and 19520704.1.
The chiral compounds listed in No. 10 can be preferably used.

The polymerizing agent and the cross-linking agent are not particularly limited, but the following can be used, for example. Examples of the polymerization agent include benzoyl peroxide (BPO) and azobisisobutyronitrile (AI).
BN) or the like can be used, and as the crosslinking agent, for example, an isocyanate crosslinking agent, an epoxy crosslinking agent, a metal chelate crosslinking agent, or the like can be used. These may be offset or one type may be used, or two or more types may be used in combination.

The addition ratio of the chiral agent is appropriately determined depending on, for example, the desired selective reflection wavelength band, but the addition ratio to the liquid crystal monomer is in the range of 5 to 23% by weight, preferably 10 to It is in the range of 20% by weight.
As described above, by controlling the addition ratio of the liquid crystal monomer and the chiral agent in this way, the selected wavelength band of the optical compensation B layer to be formed can be set within the above range. Ratio of chiral agent to liquid crystal monomer is 5% by weight
If it is smaller than this, it becomes difficult to control the selective reflection wavelength band of the formed optical compensation B layer to the low wavelength side. When the ratio is more than 23% by weight, the temperature range in which the liquid crystal monomer is cholesterically aligned, that is, the temperature range in which the liquid crystal monomer is in the liquid crystal phase is narrowed, so that the temperature control in the alignment step described later is strictly performed. Becomes necessary, and manufacturing becomes difficult.

For example, when chiral agents having the same twisting power are used, the selective reflection wavelength band formed is on the lower wavelength side as the addition ratio of the chiral agent to the liquid crystal monomer increases. Further, for example, when the addition ratio of the chiral agent to the liquid crystal monomer is the same, for example, the larger the twisting force of the chiral agent, the selective reflection wavelength band of the optical compensation B layer formed is on the low wavelength side. As a specific example, the selective reflection wavelength band of the optical compensation B layer to be formed is set to 200 to 22.
When setting in the range of 0 nm, for example, the twisting force is
A chiral agent of 5 × 10 ⁻⁴ nm ⁻¹ · (wt%) ⁻¹ may be added so as to be 11 to 13% by weight with respect to the liquid crystal monomer, and the selective reflection wavelength band is in the range of 290 to 310 nm. For example, if the twisting force is 5 × 10 ^-4 nm,
^-1 · (wt%) ^-1 chiral agent to liquid crystal monomer 7 ~
It may be blended so as to be 9% by weight.

The combination of the liquid crystal monomer and the chiral agent is not particularly limited, but specifically, the monomer agent of the formula (10) and the formula (38) are used.
And a combination of the monomer agent of the formula (11) and the chiral agent of the formula (39).

The addition ratio of the cross-linking agent or the polymerizing agent to the liquid crystal monomer is, for example, 0.1 to 10% by weight.
The range is preferably 0.5 to 8% by weight, more preferably 1 to 5% by weight. When the ratio of the cross-linking agent or the polymerizing agent to the liquid crystal monomer is 0.1% by weight or more, for example, curing of the cholesteric liquid crystal layer becomes sufficiently easy, and when it is 10% by weight or less,
For example, since the temperature range in which the liquid crystal monomer is cholesterically aligned, that is, the temperature at which the liquid crystal monomer is in the liquid crystal phase is in a sufficient range, the temperature control in the alignment step described later becomes easier.

Further, for example, various additives may be appropriately added to the coating solution, if necessary. Examples of the additives include antiaging agents, modifiers, surfactants, dyes, pigments, discoloration inhibitors, and ultraviolet absorbers.
One of these additives may be added, or two or more of them may be used in combination. Specifically, the antiaging agent is, for example, a phenol compound, an amine compound, an organic sulfur compound, a phosphine compound, or the like, and the modifier is, for example, glycols, silicones, alcohols, or the like. Known ones can be used. The surfactant is added, for example, to smooth the surface of the optical film. For example, a surfactant such as a silicone type, an acrylic type or a fluorine type can be used, and a silicone type is particularly preferable.

When liquid crystal monomers are used in this way,
The prepared coating liquid exhibits a viscosity excellent in workability such as coating and spreading. The viscosity of the coating liquid usually differs depending on the concentration and temperature of the liquid crystal monomer, but when the monomer concentration in the coating liquid is in the range of 5 to 70% by weight, the viscosity is, for example, 0. 2 to 20 mPa · s, preferably 0.5 to 15 mPa · s,
Particularly preferably, it is 1 to 10 mPa · s. Specifically, when the monomer concentration in the coating liquid is 30% by weight, the range is, for example, 2 to 5 mPa · s, and preferably 3 to 4 mPa · s. The viscosity of the coating liquid is 0.
When it is 2 mPa · s or more, for example, it is possible to further prevent the generation of a liquid flow caused by running the coating liquid.
When it is 0 mPa · s or less, for example, surface smoothness is further excellent, thickness unevenness can be further prevented, and coatability is also excellent. In addition, although the said viscosity showed the range in the temperature of 20-30 degreeC, it is not limited to this temperature.

Next, the coating liquid is applied onto the alignment layer to form a spreading layer.

The coating liquid is, for example, a roll coating method,
It may be fluidized by a conventionally known method such as a spin coating method, a wire bar coating method, a dip coating method, an extrusion method, a curtain coating method, and a spray coating method. Rouge coats are preferred.

Then, the spread layer is heat-treated to align the liquid crystal monomer in a liquid crystal state.
Since the spreading layer contains the chiral agent together with the liquid crystal monomer, the liquid crystal monomer in a liquid crystal phase (liquid crystal state) is aligned while being twisted by the chiral agent. That is, the liquid crystal monomer exhibits a cholesteric structure (helical structure).

The temperature condition for the heat treatment can be appropriately determined depending on, for example, the type of the liquid crystal monomer, specifically, the temperature at which the liquid crystal monomer exhibits liquid crystallinity, but is usually 40
To 120 ° C., preferably 50 to 100 ° C., and more preferably 60 to 90 ° C. If the temperature is 40 ° C. or higher, the liquid crystal monomer can be normally aligned sufficiently, and if the temperature is 120 ° C. or lower, for example, in terms of heat resistance, the selectivity of various alignment layers as described above is obtained. Is also wide.

Next, the liquid crystal monomer and the chiral agent are polymerized or crosslinked by subjecting the spreading layer in which the liquid crystal monomer is oriented to a crosslinking treatment or a polymerization treatment. As a result, the liquid crystal monomers are polymerized and cross-linked with each other or polymerized and cross-linked with the chiral agent while being aligned in a cholesteric structure, and the alignment state is fixed. Then, the formed polymer becomes a non-liquid crystal polymer by fixing the alignment state.

The above-mentioned polymerization treatment or crosslinking treatment can be appropriately determined depending on, for example, the type of the polymerization agent or crosslinking agent used. For example, when a photopolymerization agent or a photocrosslinking agent is used, light irradiation may be performed, and when an ultraviolet polymerization agent or an ultraviolet crosslinking agent is used, ultraviolet irradiation may be performed.

By such a manufacturing method, an optical compensation B layer having a selective reflection wavelength band of 350 nm or less, which is formed of a non-liquid crystalline polymer having a cholesteric structure and oriented, is obtained on the orientation layer. This optical compensation B layer is non-liquid crystalline because its orientation is fixed as described above. Therefore, depending on the temperature change, for example, a liquid crystal phase,
It does not change to a glass phase or a crystal phase, and orientation change due to temperature does not occur. Therefore, it can be used as a high-performance optical compensation layer that is not affected by temperature.

The optical compensation B layer of the present invention is not limited to the one produced by such a method, and the cholesteric liquid crystal polymer as described above may be used. If a liquid crystal monomer is used, not only it is easier to control the selective reflection wavelength band, but also the viscosity of the coating liquid and the like can be easily set as described above, which makes it easier to form a thin layer. It is also very easy to handle. Further, the surface of the formed cholesteric liquid crystal layer also has excellent flatness. Therefore, it can be said that the optical compensation B layer having a further excellent quality and a reduced thickness can be formed.

The cholesteric liquid crystal layer may be peeled off from the alignment layer and used as it is as the optical compensation B layer of the present invention. It can also be used as a layer.

When used as a laminate of the cholesteric liquid crystal layer and the alignment layer, the alignment layer is preferably a translucent plastic film. Examples of the plastic film include cellulosics such as TAC, polyethylene, polypropylene, poly (4-
Polyolefin such as methylpentene-1), polyimide, polyamideimide, polyamide, polyetherimide, polyetheretherketone, polyketone sulfide, polyethersulfone, polysulfone, polyphenylene sulfide, polyphenylene oxide, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate , Polyacetal, polycarbonate, polyarylate, acrylic resin, polyvinyl alcohol, polypropylene, cellulosic plastic, epoxy resin, phenol resin, polynorbornene, polyester, polystyrene, polyvinyl chloride,
Examples of the film include polyvinylidene chloride and liquid crystal polymers. These films can be optically isotropic or anisotropic. Among these plastic films, from the viewpoint of solvent resistance and heat resistance, for example, each film formed of polypropylene, polyethylene terephthalate, or polyethylene naphthalate is preferable.

The transparent alignment substrate as described above is, for example,
Although it may be a single layer, it may be, for example, a laminate in which different kinds of polymers are laminated from the viewpoint of improving strength, heat resistance, and adhesion of polymer and liquid crystal monomer.

The phase difference due to the birefringence may not be generated, or the phase difference due to the birefringence may be generated for the purpose of eliminating the polarization state of the light reflected by the polarization separation layer. . The elimination of such a polarization state is friendly to the suppression of the hue change due to the visual sense by improving the light utilization efficiency and making the light source light the same. As the transparent substrate that causes the phase difference due to the birefringence, for example, stretched films made of various polymers can be used, and those having a controlled refractive index in the thickness direction may be used. The control can be performed by, for example, adhering a polymer film to a heat shrinkable film and heating and stretching.

The thickness of the plastic film is usually 5 μm to 500 μm, preferably 10 to 200 μm.
And preferably 15 to 150 μm. When the thickness is 5 μm or more, the substrate has sufficient strength, so that problems such as breakage during manufacturing can be prevented.

Further, the cholesteric liquid crystal layer is transferred from the alignment layer (hereinafter, referred to as “first substrate”) to another substrate (hereinafter, referred to as “second substrate”), and is transferred to the second substrate as described above. It can also be used, for example, as an optical compensation B layer in a state in which cholesteric liquid crystal layers are laminated. Specifically, an adhesive layer or a pressure-sensitive adhesive layer (hereinafter referred to as "adhesive layer or the like") is laminated on at least one surface of the second substrate, and the adhesive layer or the like is formed on the first substrate. The first substrate may be peeled from the cholesteric liquid crystal layer after being adhered to the optical film above.

In this case, the alignment layer for spreading the coating liquid is not limited to, for example, its light-transmitting property or thickness.
It is preferable to select from the viewpoint of heat resistance and strength.

On the other hand, the heat resistance of the second substrate is not limited. For example, a transparent substrate, a transparent protective film and the like are preferable, and specific examples thereof include transparent glass and plastic films. Examples of the plastic film include polymethyl methacrylate, polystyrene, polycarbonate, polyether sulfone, polyphenylene sulfide, polyarylate, polyethylene terephthalate, polyethylene naphthalate, polyolefin, triacetyl cellulose, norbornene-based resin, epoxy resin, polyvinyl alcohol-based resin. And the like. In addition to this, for example, JP 2001-343529 A (WO
01/37007). Examples of the polymer material include a resin composition containing a thermoplastic resin having a substituted or unsubstituted imide group in the side chain and a thermoplastic resin having a substituted or unsubstituted phenyl group and a nitrile group in the side chain. Can be used, and examples thereof include a resin composition having an alternating copolymer of isobutene and N-methylenemaleimide and an acrylonitrile / styrene copolymer. The polymer film may be, for example, an extruded product of the resin composition. Alternatively, the coated polarizer can be used as the second substrate.

The second substrate is preferably, for example, optically isotropic, but may be optically anisotropic depending on the application. Examples of the second substrate having such optical anisotropy include, for example, a retardation film obtained by subjecting the plastic film to stretching treatment, a light scattering film having a light scattering property, a diffraction film having a diffractive ability, A polarizing film or the like may be used.

When the cholesteric liquid crystal layer and the various transparent substrates are laminated, the cholesteric liquid crystal layer may be laminated on both sides of the transparent substrate, and the number of laminated layers may be the same. The number of layers may be one, or two or more.

By such a manufacturing method, a cholesteric liquid crystal layer is formed on the alignment layer, and an optical compensation B layer is obtained. The thickness of the optical compensation B layer is, for example, 1 per layer.
˜50 μm, preferably 2˜30 μm.

The polarizing layer is not particularly limited and may be dyed by adsorbing a dichroic substance such as iodine or a dichroic dye onto various films by a conventionally known method, followed by crosslinking,
What was prepared by stretching and drying can be used. Among these, a film that transmits linearly polarized light when natural light is incident thereon is preferable, and a film having excellent light transmittance and polarization degree is preferable. Examples of various films for adsorbing the dichroic substance include polyvinyl alcohol (PVA)
Examples of the hydrophilic polymer film such as a base film, a partially formalized PVA film, an ethylene / vinyl acetate copolymer partially saponified film, and a cellulose film. In addition to these, for example, a dehydrated product of PVA A polyene oriented film such as a dehydrochlorinated product of polyvinyl chloride or the like can also be used. Of these, PVA-based films are preferable.

The thickness of the polarizing layer is not particularly limited, but is, for example, 1 to 80 μm, preferably 2 to 40 μm. The absorption axis of the polarizing layer (polarizing film) is the stretching direction of the polarizing layer (polarizing film), and is preferably perpendicular to the minor axis of the polarizing layer (polarizing film).

The polarizing layer (polarizing film) may have a transparent protective film as a protective layer adhered to one or both sides thereof via an appropriate adhesive layer.

The protective layer is not particularly limited, and a conventionally known transparent film can be used. For example, those having excellent transparency, mechanical strength, thermal stability, moisture barrier property, isotropic property, etc. are preferable. . Specific examples of the material of such a transparent protective layer include a cellulose-based resin such as triacetyl cellulose, a polyester-based, a polycarbonate-based, a polyamide-based, a polyimide-based, a polyether sulfone-based,
Examples thereof include transparent resins such as polysulfone-based, polystyrene-based, polynorbornene-based, polyolefin-based, acrylic-based, and acetate-based resins. Further, the above-mentioned acrylic, urethane-based, acrylic urethane-based, epoxy-based, silicone-based, etc. thermosetting resins or ultraviolet-curing resins are also included. Among these, a TAC film having a surface saponified with an alkali or the like is preferable from the viewpoint of polarization characteristics and durability.

Further, as the protective film, Japanese Patent Application Laid-Open No. 200
Examples thereof include the polymer film described in JP-A 1-343529 (WO01 / 37007). Examples of the polymer material include a resin composition containing a thermoplastic resin having a substituted or unsubstituted imide group in the side chain and a thermoplastic resin having a substituted or unsubstituted phenyl group and a nitrile group in the side chain. Can be used, for example, isobutene and N-
An example of the resin composition is an alternating copolymer of methylene maleimide and an acrylonitrile / styrene copolymer. The polymer film may be, for example, an extruded product of the resin composition.

The protective layer preferably has no color, for example. Specifically, the retardation value (Rth) in the film thickness direction represented by the following formula is -90 nm to +7.
It is preferably in the range of 5 nm, more preferably −
80 nm to +60 nm, particularly preferably -70 n
The range is from m to +45 nm. The phase difference value is -90n
Within the range of m to +75 nm, the coloring (optical coloring) of the polarizing plate due to the protective layer can be sufficiently eliminated. In addition,
In the following formula, nx, ny, and nz are the X axis,
The refractive indices in the Y-axis and Z-axis directions are shown, and the X-axis is the axial direction in which the maximum refractive index is in the plane of the protective layer, and the Y-axis is the X-axis in the plane of the protective layer. Is an axial direction perpendicular to the Z axis, and the Z axis is the X axis and the Y axis.
The thickness direction perpendicular to the axis is shown. d represents the film thickness of the protective layer. Rth = {[(nx + ny) / 2] -nz} · d

Further, the transparent protective layer may further have an optical compensation function. As such a transparent protective layer having an optical compensation function, for example, for the purpose of preventing coloring or the like, or enlarging the viewing angle for good visual recognition, which is caused by a change in the viewing angle based on the phase difference in the liquid crystal cell. Known ones can be used. Specific examples include various stretched films obtained by uniaxially or biaxially stretching the transparent resin described above, oriented films such as liquid crystal polymers, and laminates in which an orientation layer such as liquid crystal polymers is arranged on a transparent substrate. To be Among these, because it is possible to achieve a wide viewing angle with good visibility,
An alignment film of the liquid crystal polymer is preferable, and in particular, an optical compensation retardation plate in which an optical compensation layer composed of a tilted alignment layer of a discotic or nematic liquid crystal polymer is supported by the above-mentioned triacetyl cellulose film is preferable. . Examples of such an optical compensation retardation plate include commercially available products such as "WV film" manufactured by Fuji Photo Film Co., Ltd. Incidentally, the optical compensation retardation plate,
It may be one in which optical properties such as retardation are controlled by laminating two or more film supports such as the above retardation film and triacetyl cellulose film.

The thickness of the transparent protective layer is not particularly limited and can be appropriately determined depending on, for example, the phase difference and the protection strength, but is usually 500 μm or less, and preferably 5 to 3
The transparent protective layer having a thickness of 00 μm, more preferably in the range of 5 to 150 μm, is, for example, a method of applying the various transparent resins to a polarizing film, or the transparent resin film or the optical compensation phase difference plate to the polarizing film. It can be appropriately formed by a conventionally known method such as a laminating method, or a commercially available product can be used.

Further, the transparent protective layer may be further subjected to, for example, a hard coat treatment, an antireflection treatment, a treatment for the purpose of preventing or diffusing sticking, antiglare or the like. The hard coat treatment is, for the purpose of preventing scratches on the surface of the polarizing plate, for example, a treatment of forming a cured film excellent in hardness and slipperiness, which is composed of a curable resin, on the surface of the transparent protective layer. Is. As the curable resin, for example, a silicone-based, urethane-based, acrylic-based, or epoxy-based UV-curable resin can be used, and the treatment can be performed by a conventionally known method. The prevention of sticking is intended to prevent adhesion with an adjacent layer. The antireflection treatment aims at preventing reflection of external light on the surface of the polarizing plate, and can be performed by forming a conventionally known antireflection layer or the like.

The antiglare treatment is for the purpose of preventing visual interference of light transmitted through the polarizing plate due to reflection of external light on the surface of the polarizing plate. For example, the transparent protective layer can be formed by a conventionally known method. This can be performed by forming a fine uneven structure on the surface. Examples of the method for forming such a concavo-convex structure include a surface roughening method such as a sandblast method and embossing, and a method of forming the transparent protective layer by blending transparent fine particles with the transparent resin as described above. To be

Examples of the transparent fine particles include silica, alumina, titania, zirconia, tin oxide, indium oxide, cadmium oxide and antimony oxide. In addition to these, inorganic fine particles having conductivity, cross-linking or It is also possible to use organic fine particles composed of uncrosslinked polymer particles or the like. The average particle size of the transparent fine particles is not particularly limited, but is, for example, 0.5 to 20 μm.
The range is m. The blending ratio of the transparent fine particles is
Although not particularly limited, in general, the transparent resin 1 as described above is used.
The range is preferably 2 to 70 parts by mass, more preferably 5 to 50 parts by mass, per 100 parts by mass.

The antiglare layer containing the transparent fine particles may be used as, for example, the transparent protective layer itself, or may be formed as a coating layer on the surface of the transparent protective layer. Further, the anti-glare layer may also serve as a diffusion layer (visual compensation function or the like) for diffusing the light transmitted through the polarizing plate and expanding the viewing angle.

The antireflection layer, the antisticking layer, the diffusion layer, the antiglare layer and the like are provided separately from the transparent protective layer, for example, as an optical layer composed of a sheet or the like provided with these layers. It may be laminated on a plate. When a transparent protective film is provided on both sides of the polarizing layer, a transparent protective film containing a different polymer or the like on each side may be used. Further, the optical compensation A layer or the optical compensation B layer can be used as a protective film on one surface of the polarizing plate. With such a configuration, the thickness of the layer can be reduced, which is preferable.

The method for laminating the polarizing layer and the transparent protective film which is the protective layer is not particularly limited, and a conventionally known method can be used. In general, the type can be appropriately determined depending on the material and the like of each of the constituent elements. Examples of the adhesive include acrylic-based, vinyl alcohol-based, silicone-based, polyester-based, polyurethane-based and polyether-based polymer adhesives, and rubber-based adhesives. The above-mentioned pressure-sensitive adhesives and adhesives are difficult to peel off even under the influence of humidity and heat, and have excellent light transmittance and polarization degree.

Specifically, when the polarizer is a PVA-based film, for example, from the viewpoint of stability of adhesion treatment, PV
A-based adhesives are preferred. These adhesives or pressure-sensitive adhesives may be directly applied to the surface of the polarizer or the transparent protective layer, or a layer such as a tape or sheet composed of the adhesive or pressure-sensitive adhesive may be arranged on the surface. You may. In addition, for example, when prepared as an aqueous solution, other additives and a catalyst such as an acid may be added as necessary. When applying the adhesive, for example, in the adhesive aqueous solution,
Furthermore, you may mix | blend other additives and catalysts, such as an acid.

The thickness of such an adhesive layer is not particularly limited, but is, for example, 1 nm to 500 nm, preferably 10 nm to 300 nm, more preferably 20 n.
m to 100 nm.

A polarizing layer as described above, an optical compensation A layer,
The polarizing plate with an optical compensation function of the present invention can be manufactured by laminating the optical compensation B layer. Polarizing layer and optical compensation A
When laminating the layers, the angle formed by the absorption axis direction of the polarizing layer and the slow axis direction of the optical compensation A layer is 85 ° or more and 9 ° or more.
It is preferable to arrange them so that the angle is 5 ° or less. Since the absorption axis of the polarizing layer is perpendicular to the minor axis of the polarizing layer, and the slow axis of the optical compensation A layer is parallel to the minor axis of the stretched polymer film when produced by tenter transverse axis stretching. This is because both the polarizing layer and the optical compensation A layer can be laminated in a long length, and the above relationship can be easily obtained. If it becomes possible to stack long sheets in this way, so-called "Roll
It is possible to manufacture "To Roll" and improve the manufacturing efficiency.

The method for laminating the polarizing layer, the optical compensation A layer, and the optical compensation B layer is not particularly limited, and a conventionally known method can be used. For example, a method in which the polarizing layer, the optical compensation A layer, and the optical compensation B layer are separately prepared, and the respective layers are laminated can be mentioned. The laminating method is not particularly limited, and the same pressure-sensitive adhesive or adhesive as described above can be used. When the optical compensation B layer is separately formed on the base material, the base material may be laminated including the base material, or the base material may be removed after the lamination to transfer the optical compensation B layer. . Further, the method of laminating the polarizing layer, the optical compensation A layer, and the optical compensation B layer is as follows: (1) A laminate (film) of the optical compensation A layer and the polarizing layer is manufactured in advance, and the optical compensation Method of laminating B layer, (2) Method of preliminarily producing a laminate of optical compensation B layer and polarizing layer (film), and further laminating optical compensation A layer thereon, (3) Optical compensation A layer Optical compensation B
And a layer is formed in advance to form an optical compensation layer, and a polarizing layer (film) is further laminated on the optical compensation layer.

The method for producing a laminate of the polarizing layer (film) and the optical compensation A layer shown in (1) above is not particularly limited,
It can be performed by a conventionally known method. In general,
The same adhesives and adhesives as above can be used.
It can be appropriately determined depending on the material of each of the constituent elements. For example, a polarizing layer and an optical compensation A layer may be prepared, respectively, and the polarizing layer and the optical compensation A layer may be laminated using a pressure-sensitive adhesive or an adhesive.

In order to further laminate the optical compensation B layer on the laminate having the polarizing layer and the optical compensation A layer, (a) the optical compensation A layer is subjected to, for example, a rubbing treatment to have a function as an alignment layer. And a method of forming an optical compensation B layer on the optical compensation A layer, (b) forming an alignment layer on the optical compensation A layer,
A method of forming an optical compensation B layer on the alignment layer, (c) forming an optical compensation B layer on an alignment substrate prepared separately, and then optically compensating the optical compensation B layer with an adhesive or a pressure-sensitive adhesive. A method of transferring onto a layer can be used. When the method (c) is used, the alignment base material may or may not be removed after the optical compensation B layer is transferred.

Next, specific forms of the polarizing plate with an optical compensation function of the present invention are illustrated in FIGS. The polarizing plate with an optical compensation function of the present invention shown in FIG. 2 has the following configuration. The protective layer 1 is laminated on both surfaces of the polarizing layer 3 with the adhesive layer 2 interposed therebetween. An optical compensation A layer 4 is laminated on one surface of the protective layer 1 with an adhesive layer 2 interposed therebetween. Further, on the optical compensation A layer 4, an optical compensation B layer 5 formed on a supporting base material 7 is laminated via an adhesive layer 2. An example of the polarizing plate with an optical compensation function of the present invention, from which the supporting substrate 7 is further removed, is shown in FIG.

The polarizing plate with an optical compensation function of the present invention shown in FIG. 4 has the following constitution. The protective layer 1 is laminated on one surface of the polarizing layer 3 via the adhesive layer 2, and the optical compensation A layer 4 is laminated on the other surface thereof via the adhesive layer 2. Further, an optical compensation B layer 5 formed on a supporting base material 7 is laminated on the optical compensation A layer 4 via an adhesive layer 2.
An example of the polarizing plate with an optical compensation function of the present invention, in which the supporting substrate 7 is further removed therefrom, is shown in FIG.

The polarizing plate with an optical compensation function of the present invention shown in FIG. 6 has the following constitution. The protective layer 1 is laminated on both surfaces of the polarizing layer 3 with the adhesive layer 2 interposed therebetween. An optical compensation A layer 4 is laminated on one surface of the protective layer 1 with an adhesive layer 2 interposed therebetween. Further, an alignment layer 6 is formed on the optical compensation A layer 4.
And the optical compensation B layer 5 is formed on the alignment layer 6.

The polarizing plate with an optical compensation function of the present invention shown in FIG. 7 has the following constitution. The protective layer 1 is laminated on one surface of the polarizing layer 3 via the adhesive layer 2, and the optical compensation A layer 4 is laminated on the other surface thereof via the adhesive layer 2. Further, an alignment layer 6 is formed on the optical compensation A layer 4, and an optical compensation B layer 5 is formed on the alignment layer 6.

Next, a method of further laminating the optical compensation A layer on the laminate of the optical compensation B layer and the polarizing layer (film) shown in the above (2) will be described. The method for producing the laminate of the optically-compensatory B layer and the polarizing layer is not particularly limited, and the conventionally known method as described above can be used. For example, (a) a method of rubbing a polarizing layer to have a function as an alignment layer and forming an optical compensation B layer on the polarizing layer, (b) forming an alignment layer on the polarizing layer, A method of forming an optical compensation B layer on the alignment layer, (c) forming an optical compensation B layer on a separately prepared alignment base material, and the optical compensation B layer on the polarizing layer via an adhesive or a pressure-sensitive adhesive. And the like can be used. When the method (c) is used, the alignment base material may or may not be removed after the optical compensation B layer is transferred.

The method for further laminating the optical compensation A layer on the laminate having the polarizing layer and the optical compensation B layer is not particularly limited, and it can be carried out by the conventionally known method as described above.

Specific examples of the polarizing plate with an optical compensation function of the present invention are shown in FIGS. The polarizing plate with an optical compensation function of the present invention shown in FIG. 8 has the following configuration. The protective layer 1 is laminated on both surfaces of the polarizing layer 3 with the adhesive layer 2 interposed therebetween. The optical compensation B layer 5 formed on a supporting base material (not shown) is laminated on one surface of the protective layer 1 via the adhesive layer 2, and the base material is removed. Further, the optical compensation A layer 4 is laminated on the optical compensation B layer 5 via the adhesive layer 2.

The polarizing plate with optical compensation function of the present invention shown in FIG. 9 has the following constitution. The protective layer 1 is laminated on both surfaces of the polarizing layer 3 with the adhesive layer 2 interposed therebetween. An alignment layer 6 is formed on one surface of the protective layer 1, and an optical compensation B layer 5 is formed thereon. Further, an optical compensation A layer 4 is laminated on the optical compensation B layer 5 with an adhesive layer 2 interposed therebetween.

Next, a method for forming an optical compensation layer by previously laminating the optical compensation A layer and the optical compensation B layer, and laminating a polarizing layer (film) on the optical compensation layer will be described.

As a method of preliminarily laminating the optical compensation A layer and the optical compensation B layer, (a) the optical compensation A layer is subjected to, for example, a rubbing treatment so as to have a function as an alignment layer, and the optical compensation A layer is optically coated. Method of forming compensation B layer, (b) forming an alignment layer on the optical compensation A layer, and optically compensating B on the alignment layer
A method of forming a layer, (c) a method of forming an optical compensation B layer on a separately prepared alignment substrate, and transferring the optical compensation B layer onto the optical compensation A layer via an adhesive or a pressure-sensitive adhesive. Can be used. When the method (c) is used, the alignment base material may or may not be removed after the optical compensation B layer is transferred.

A method for laminating a laminate having an optical compensation A layer and an optical compensation B layer on a polarizing layer (film) is as follows:
The method is not particularly limited, and it can be performed by the conventionally known method as described above. When laminating a laminate having an optical compensation A layer and an optical compensation B layer on the polarizing layer, the optical compensation A
Either the layer or the optical compensation B layer may face the polarizing layer.

Specific examples of the polarizing plate with an optical compensation function of the present invention are shown in FIGS.

The polarizing plate with an optical compensation function of the present invention shown in FIG. 10 has the following constitution. In the optical compensation A layer 4,
The optical compensation B layer 5 formed on a supporting base material (not shown) is laminated via the adhesive layer 2, and the base material is removed. On one surface of the polarizing layer 3, the optical compensation B layer of the laminate is provided on the polarizing layer 3.
The laminates are laminated so as to face each other via the adhesive layer 2. The protective layer 1 is formed on the other surface of the polarizing layer 3.
Are laminated via the adhesive layer 2.

The polarizing plate with an optical compensation function of the present invention shown in FIG. 11 has the following constitution. An alignment layer 6 is formed on the optical compensation A layer 4, and an optical compensation B layer 5 is formed thereon.
Produce a laminate. Separately, the protective layer 1 is laminated on both surfaces of the polarizing layer 3 with the adhesive layer 2 interposed therebetween. On one side of the protective layer 1, the optical compensation B layer 5 faces the protective layer 1, and the laminate is laminated via an adhesive layer 2. FIG. 12 shows an example in which the laminate is laminated on one surface of the polarizing layer 3 and the protective layer 1 is laminated on the other surface via the adhesive layer 2. The laminated body is laminated such that the optical compensation B layer 5 faces the polarizing layer 3.

In practical use, the polarizing plate with an optical compensation function of the present invention may further include other optical layers in addition to the polarizing plate of the present invention. Examples of the optical layer include conventionally known various optical layers used for forming a liquid crystal display device, such as a polarizing plate, a reflector, a semi-transmissive reflector, and a brightness enhancement film as shown below. These optical layers may be used alone or in combination of two or more,
One layer may be used or two or more layers may be stacked. A polarizing plate with an optical compensation function further including such an optical layer is preferably used as, for example, an integrated polarizing plate having an optical compensation function, and for example, it is arranged on the surface of a liquid crystal cell,
It is suitable for use in various image display devices.

The integrated polarizing plate will be described below. First, an example of the reflective polarizing plate or the semi-transmissive reflective polarizing plate will be described. The reflection type polarizing plate is laminated with a polarizing plate on the polarizing plate with an optical compensation function of the present invention, and the semi-transmissive reflection type polarizing plate is laminated with a polarizing plate with an optical compensation function of the present invention on a semi-transmission reflecting plate. Has been done.

The reflection type polarizing plate is usually arranged on the back side of a liquid crystal cell and is used in a liquid crystal display device (reflection type liquid crystal display device) of a type which reflects incident light from the viewing side (display side) to display. Can be used. Such a reflective polarizing plate has an advantage that a liquid crystal display device can be thinned, for example, since a light source such as a backlight can be omitted.

The reflective polarizing plate can be manufactured by a conventionally known method such as a method of forming a reflecting plate made of metal or the like on one surface of the polarizing plate exhibiting the elastic modulus.
Specifically, for example, one surface (exposed surface) of the transparent protective layer in the polarizing plate is matted if necessary, and a metal foil or a vapor deposition film made of a reflective metal such as aluminum is provided on the surface as a reflection plate. And a reflective polarizing plate formed as above.

Further, as described above, on the transparent protective layer in which fine particles are contained in various transparent resins and whose surface has a fine concavo-convex structure, a reflection plate reflecting the fine concavo-convex structure is formed.
A reflective polarizing plate and the like are also included. A reflector whose surface has a fine concavo-convex structure has the advantage that diffused incident light is diffused to prevent directivity and glare and prevent uneven brightness. Such a reflector is, for example, on the uneven surface of the transparent protective layer, a vacuum deposition method, an ion plating method, a vapor deposition method such as a sputtering method, a plating method, or the like, by a conventionally known method, directly by the metal foil or It can be formed as a metal vapor deposition film.

Further, instead of the method of directly forming the reflection plate on the transparent protective layer of the polarizing plate as described above, a reflection sheet in which a reflection layer is provided on a suitable film such as the transparent protective film as the reflection plate. Etc. may be used. Since the reflective layer in the reflective plate is usually composed of a metal, for example, prevention of a decrease in reflectance due to oxidation, and thus a long-lasting initial reflectance, from the viewpoint of avoiding the separate formation of a transparent protective layer, and the like, It is preferable that the form of use is such that the reflective surface of the reflective layer is covered with the film, the polarizing plate, or the like.

On the other hand, the semi-transmissive polarizing plate has a semi-transmissive reflecting plate in place of the reflecting plate in the reflective polarizing plate. Examples of the semi-transmissive reflector include a half mirror that reflects light through a reflective layer and transmits light.

The semi-transmissive polarizing plate is usually provided on the back side of the liquid crystal cell and reflects incident light from the viewing side (display side) when the liquid crystal display device or the like is used in a relatively bright atmosphere. To display the image, and in a relatively dark atmosphere,
It can be used for a liquid crystal display device of a type that displays an image using a built-in light source such as a backlight built in the back side of a semi-transmissive polarizing plate. That is, the semi-transmissive polarizing plate can save energy for using a light source such as a backlight in a bright atmosphere, while it can be used in a relatively dark atmosphere by using the built-in light source. It is useful for the formation of etc.

Next, an example of a polarizing plate in which a brightness enhancement film is further laminated on the polarizing plate with an optical compensation function of the present invention will be described.

The brightness enhancement film is not particularly limited, and transmits linearly polarized light having a predetermined polarization axis, such as a multilayered thin film of a dielectric or a multilayered laminate of thin films having different refractive index anisotropies. Then, other light or the like that exhibits a characteristic of being reflected can be used. An example of such a brightness enhancement film is the product name “D-BEF” manufactured by 3M Company. In addition, a cholesteric liquid crystal layer, particularly an oriented film of a cholesteric liquid crystal polymer, or one in which the oriented liquid crystal layer is supported on a film substrate can be used. These reflect the circularly polarized light on one of the left and right and transmit the other light. For example, the product name "PCF350" manufactured by Nitto Denko Corporation and the product name "Tran manufactured by Merck
smax ”and the like.

The various polarizing plates of the present invention may be, for example, an optical member including two or more optical layers by laminating a laminated polarizing plate including the above-described birefringent layer and an optical layer. Good.

The optical member in which two or more optical layers are laminated in this way can be formed, for example, by a method of sequentially laminating separately in the manufacturing process of a liquid crystal display device or the like.
When used as an optical member laminated in advance, there are advantages that, for example, the quality stability and the assembly workability are excellent, and the manufacturing efficiency of liquid crystal display devices and the like can be improved. In addition, for stacking,
Similar to the above, various adhesive means such as an adhesive layer can be used.

The polarizing plate with an optical compensation function of the present invention and the above-mentioned various polarizing plates can be easily laminated on other members such as a liquid crystal cell. Therefore, a pressure-sensitive adhesive layer or an adhesive layer is further added. It is preferable to have these, and these can be arranged on one side or both sides of the polarizing plate. The material of the pressure-sensitive adhesive layer is not particularly limited, and conventionally known materials such as acrylic polymers can be used. In particular, prevention of foaming and peeling due to moisture absorption, deterioration of optical characteristics due to thermal expansion difference, and warpage of liquid crystal cell. From the viewpoint of prevention, and further, in terms of formability of a liquid crystal display device having high quality and excellent durability, for example, an adhesive layer having a low moisture absorption rate and excellent heat resistance is preferable. Further, it may be an adhesive layer containing fine particles and exhibiting light diffusion property. The pressure-sensitive adhesive layer is formed on the surface of the polarizing plate by, for example, adding a solution or a melt of various pressure-sensitive adhesive materials directly to a predetermined surface of the polarizing plate by a spreading method such as casting or coating. Or a method of forming a pressure-sensitive adhesive layer on a separator described later and transferring it to a predetermined surface of the polarizing plate, or the like. Such a layer may be formed on any surface of the polarizing plate, for example, on the exposed surface of the optical compensation layer in the polarizing plate.

When the surface of the pressure-sensitive adhesive layer provided on the polarizing plate is thus exposed, the surface of the pressure-sensitive adhesive layer may be covered with a separator for the purpose of preventing contamination until the pressure-sensitive adhesive layer is put into practical use. preferable. This separator is
A suitable film such as the transparent protective film can be formed by a method of providing a release coating with a release agent such as silicone type, long chain alkyl type, fluorine type, molybdenum sulfide, etc., if necessary.

The pressure-sensitive adhesive layer and the like may be, for example, a single layer body or a laminated body. As the laminate, for example,
It is also possible to use a laminate in which monolayers of different compositions and different types are combined. Further, when they are arranged on both sides of the polarizing plate, they may be, for example, the same pressure-sensitive adhesive layer, or may have different compositions or different types of pressure-sensitive adhesive layers.

The thickness of the pressure-sensitive adhesive layer can be appropriately determined depending on, for example, the constitution of the polarizing plate, and is generally 1 to 500.
μm. As the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer,
For example, those having excellent optical transparency and exhibiting appropriate wettability, cohesiveness, and adhesive tackiness are preferable. As a concrete example, an acrylic polymer or a silicone polymer,
Examples thereof include adhesives prepared by appropriately using polymers such as polyester, polyurethane, polyether and synthetic rubber as base polymers.

The pressure-sensitive adhesive property of the pressure-sensitive adhesive layer can be controlled by, for example, the composition and molecular weight of the base polymer forming the pressure-sensitive adhesive layer, the crosslinking method, the content ratio of the crosslinkable functional group, the mixing ratio of the crosslinking agent, and the like. This can be appropriately performed by a conventionally known method such as adjusting the degree of crosslinking or the molecular weight.

Each layer such as the polarizing plate with the optical compensation function of the present invention, the polarizing film forming various optical members (various polarizing plates further laminating optical layers), the transparent protective layer, the optical layer, the pressure-sensitive adhesive layer and the like. May be one having an ultraviolet absorbing ability by being appropriately treated with an ultraviolet absorber such as a salicylate compound, a benzophenone compound, a benzotriazole compound, a cyanoacrylate compound, a nickel complex salt compound.

The polarizing plate with an optical compensation function of the present invention is preferably used for forming various devices such as a liquid crystal display device as described above. For example, the polarizing plate is arranged on one side or both sides of a liquid crystal cell. As a liquid crystal panel, reflective type or transflective type,
Alternatively, it can be used in a liquid crystal display device such as a transmissive / reflective type.

The type of the liquid crystal cell forming the liquid crystal display device can be arbitrarily selected. For example, an active matrix drive type represented by a thin film transistor type, a simple matrix represented by a twist nematic type or a super twist nematic type. Various types of liquid crystal cells such as a driving type can be used. Among these, the polarizing plate with an optical compensation function of the present invention is particularly preferably VA (vertical alignment; Vertical
Aligned) The cell has a very good optical compensation, so V
It is very useful as a viewing angle compensation film for A-mode liquid crystal display devices.

Further, the liquid crystal cell usually has a structure in which liquid crystal is injected into a gap between opposed liquid crystal cell substrates, and the liquid crystal cell substrate is not particularly limited and, for example, a glass substrate or a plastic substrate is used. Can be used. The material of the plastic substrate is not particularly limited, and conventionally known materials can be used.

When a polarizing plate and an optical member are provided on both surfaces of the liquid crystal cell, they may be of the same kind or may be different. Further, when forming the liquid crystal display device, for example, one or two or more layers of appropriate components such as a prism array sheet, a lens array sheet, a light diffusing plate and a backlight can be arranged at appropriate positions.

Further, the liquid crystal display device of the present invention includes a polarizing plate, and is not particularly limited except that the polarizing plate with an optical compensation function of the present invention is used as the polarizing plate. Further, when the light source further has a light source, it is not particularly limited, but for example, a plane light source that emits polarized light is preferable because light energy can be effectively used.

In the liquid crystal display device of the present invention, for example, a diffusion plate, an anti-glare layer, an antireflection film, a protective layer or a protective plate is further arranged on the optical film (polarizing plate) on the viewing side, or a liquid crystal panel. A compensating retardation plate or the like may be appropriately disposed between the liquid crystal cell and the polarizing plate in the above.

The polarizing plate with an optical compensation function of the present invention is not limited to the liquid crystal display device as described above, and includes, for example, an organic electroluminescence (EL) display, a plasma display (PD), an FED (field emission display). : Field Emission Display) and other self-luminous image display devices.

The electroluminescence (EL) display device provided with the polarizing plate with the optical compensation function of the present invention will be described below. The EL display device of the present invention is a display device having the polarizing plate with an optical compensation function of the present invention.
The L device may be either an organic EL or an inorganic EL.

In recent years, also in EL display devices, it has been proposed to use an optical film such as a polarizer or a polarizing plate together with a λ / 4 plate to prevent reflection from the electrode in the black state. The polarizing plate with an optical compensation function of the present invention is, particularly, when linearly polarized light, circularly polarized light or elliptically polarized light is emitted from the EL layer, or even when natural light is emitted in the front direction, It is very useful when the outgoing light in the oblique direction is partially polarized.

First, a general organic EL display device will be described. The organic EL display device generally has a light emitting body (organic EL light emitting body) in which a transparent electrode, an organic light emitting layer, and a metal electrode are laminated in this order on a transparent substrate. The organic light emitting layer is a laminate of various organic thin films, for example, a laminate of a hole injection layer made of a triphenylamine derivative or the like and a light emitting layer made of a fluorescent organic solid such as anthracene, or the like. Various combinations such as a laminated body of a light emitting layer and an electron injection layer made of a perylene derivative, a laminated body of the hole injection layer, a light emitting layer and an electron injection layer can be mentioned.

Then, such an organic EL display device is
By applying a voltage to the anode and the cathode, holes and electrons are injected into the organic light emitting layer, and energy generated by recombination of the holes and electrons excites and excites the fluorescent substance. The fluorescent substance thus emitted emits light when it returns to the ground state. The mechanism of the recombination of holes and electrons is the same as that of a general diode, and the current and the emission intensity show a strong non-linearity with rectification with respect to the applied voltage.

In the organic EL display device, at least one of the electrodes needs to be transparent in order to extract light emitted from the organic light emitting layer. Therefore, a transparent conductor such as indium tin oxide (ITO) is usually used. The transparent electrode formed in 1) is used as an anode. On the other hand, in order to facilitate electron injection and increase luminous efficiency, it is important to use a substance having a small work function for the cathode. Usually, Mg-Ag or Al is used.
-A metal electrode such as Li is used.

In the organic EL display device having such a structure, it is preferable that the organic light emitting layer is formed of an extremely thin film having a thickness of, for example, about 10 nm. This is because light is almost completely transmitted through the organic light emitting layer as well as the transparent electrode. As a result, at the time of non-light emission, the light that enters from the surface of the transparent substrate, passes through the transparent electrode and the organic light emitting layer, and is reflected by the metal electrode again exits to the surface side of the transparent substrate. Therefore, when viewed from the outside, the display surface of the organic EL display device looks like a mirror surface.

The organic EL display device of the present invention includes, for example, an organic EL display including the organic EL light emitter having a transparent electrode on the front surface side of the organic light emitting layer and a metal electrode on the back surface side of the organic light emitting layer. In the device, on the surface of the transparent electrode,
The polarizing plate with an optical compensation function of the present invention is preferably arranged, and further, a λ / 4 plate is preferably arranged between the polarizing plate and the EL element. As described above, by arranging the polarizing plate with the optical compensation function of the present invention, the organic E showing the effect that the reflection of the outside world is suppressed and the visibility can be improved.
It becomes an L display device. Further, it is preferable that a retardation plate is further arranged between the transparent electrode and the optical film.

The retardation plate and the polarizing plate with an optical compensation function have a function of polarizing light that is incident from the outside and reflected by the metal electrode. Therefore, the polarization effect causes the mirror surface of the metal electrode to move to the outside. It has the effect of not being visible. In particular, if a quarter wave plate is used as the retardation plate and the angle formed by the polarization directions of the polarizing plate and the retardation plate is adjusted to π / 4, the mirror surface of the metal electrode is completely shielded. can do. That is, of the external light that enters the organic EL display device, only the linearly polarized light component is transmitted by the polarizing plate. This linearly polarized light is generally elliptically polarized light by the retardation plate, and in particular, when the retardation plate is a quarter wavelength plate and the angle is π / 4, it becomes circularly polarized light.

The circularly polarized light is transmitted through, for example, the transparent substrate, the transparent electrode and the organic thin film, is reflected by the metal electrode, is transmitted again through the organic thin film, the transparent electrode and the transparent substrate, and is again transmitted by the retardation plate. It becomes linearly polarized light. Since this linearly polarized light is orthogonal to the polarization direction of the polarizing plate, it cannot pass through the polarizing plate, and as a result, the mirror surface of the metal electrode can be completely shielded as described above. .

[0178]

EXAMPLES The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

As the polarizing plate, NPF-1224DU (manufactured by Nitto Denko) having a total thickness of 190 μm was used.

Example 1 A norbornene film having a thickness of 100 μm was transversely stretched at 177 ° C. to give a thickness of 80 μm.
An optically compensated A layer of m was obtained. The polarizing plate (trade name: NPF
-1224DU (manufactured by Nitto Denko) was coated with a 1 wt% aqueous solution of polyvinyl alcohol and dried at 90 ° C. for 5 minutes to form a film having a thickness of 0.01 μm. Then
The film was rubbed to form an alignment layer. 92 parts by weight of the nematic liquid crystal monomer represented by the chemical formula (10), and the twisting force represented by the chemical formula (38) of 5.5 × 10 ⁻⁴ nm
^-1 · (wt%) ⁻¹ polymerizable chiral agent 8 parts by weight, UV polymerization initiator 5 parts by weight and methyl ethyl ketone 300 parts by weight were mixed to prepare a mixture designed to have a selective reflection wavelength of 290 to 310 nm. . This mixture was applied onto the alignment layer to form a spreading layer.

[0181]

[Chemical 12]

The polarizing plate having the spreading layer was heat-treated at 90 ° C. for 1 minute and further UV-crosslinked. As a result, an optical compensation B layer having a thickness of 2.5 μm was formed on the surface of the polarizing plate, and a laminate having a total thickness of 193 μm was attached in a lengthy manner.

The laminate thus obtained and the above-mentioned optical compensation A layer are attached in a lengthy manner with an acrylic pressure-sensitive adhesive having a thickness of 25 μm, and a polarizing plate with an optical compensation function having a total thickness of 298 μm is obtained. A long plate (No. 1) was obtained (see FIG. 13). The angle formed by the absorption axis of the polarizing layer and the slow axis of the optical compensation A layer of the polarizing plate with an optical compensation function manufactured in this manner was 90 °.

Example 2 A triacetyl cellulose film having a thickness of 80 μm was transversely stretched with a tenter to obtain a thickness of 50 μm.
An optically compensated A layer of m was obtained. 92 parts by weight of the nematic liquid crystal monomer represented by the chemical formula (10), the chemical formula (38)
8 parts by weight of a polymerizable chiral agent having a twisting power of 5.5 × 10 ⁻⁴ nm ⁻¹ · (wt%) ⁻¹ , 5 parts by weight of a UV polymerization initiator and 300 parts by weight of methyl ethyl ketone are mixed to give a selective reflection wavelength of 2
The same mixture as in Example 1 designed to be 90-310 nm was prepared. This mixture was applied onto a biaxially stretched PET film to form a spreading layer.

The biaxially stretched PET film having the developed layer thus obtained was heat-treated at 90 ° C. for 1 minute and further UV-crosslinked. As a result, an optical compensation B layer having a thickness of 2.0 μm was formed on the surface of the biaxially stretched PET film. Then, the optical compensation A layer and the biaxially stretched PET film are formed to have a thickness of 25 so that the optical compensation B layer faces the optical compensation A layer.
The lamination was performed via a μm acrylic pressure-sensitive adhesive layer. Then, the biaxially stretched PET film was peeled off to obtain an optical compensation layer having an optical compensation A layer and an optical compensation B layer.

A polyvinyl alcohol film having a thickness of 80 μm was immersed in an aqueous iodine solution having an iodine concentration of 0.05% by weight at 30 ° C. for 60 seconds for dyeing, and then immersed in an aqueous boric acid solution having a boric acid concentration of 4% by weight for 60 seconds. After being stretched to 5 times the original length while soaking, it is dried at 50 ° C for 4 minutes to obtain a thickness of 20.
A polarizing layer of μm was obtained.

Finally, the polarizing layer and a thickness of 80
μm triacetyl cellulose, an optical compensation layer on the other side, and a thickness of 5 μm so that the optical compensation A layer is on the polarizing layer side.
Bonded via the polyvinyl alcohol adhesive of
Polarizing plate with optical compensation function (N
o. 2) was obtained in a long size (see FIG. 14).

(Example 3) A polarizing layer and a composite optical compensation layer similar to those of Example 2 were bonded together with an acrylic pressure-sensitive adhesive having a thickness of 25 µm so that the optical compensation B layer was on the polarizing layer side. Other than the same as in Example 2, the total thickness is 207 μm.
A long polarizing plate (No. 3) having an optical compensation function of m was obtained (see FIG. 15).

Regarding the optical compensation A layer and the optical compensation A layer, and the optical compensation B layer and the optical compensation B layer of the polarizing plates with optical compensation functions obtained in Examples 1 to 3, prince measurement based on the principle of parallel Nicols rotation Equipment made, product name KOBRA-2
Using 1ADH, the retardation value Re in the normal direction and the retardation value Rth in the thickness direction were obtained. The results are shown in Table 1.

[0190]

[Table 1]

From Table 1, it can be seen that the obtained optical compensation B layer is much thinner than the optical compensation A layer. Therefore, it is possible to provide a polarizing plate having an optical compensation function, which is thinner than a laminated polarizing plate including two or more optical compensation A layers, which is a stretched polymer film, and includes an optical compensation A layer and an optical compensation B layer.

(Examples 4 to 6) The polarizing plates with optical compensation functions (Nos. 1 to 3) obtained in Examples 1 to 3 were each 5 cm ×
It was cut into a size of 5 cm, and each of the pieces was combined with the above-mentioned polarizing plate and arranged on both surfaces of a VA type liquid crystal cell so that their slow axes were orthogonal to each other, to obtain a liquid crystal display device. The optical compensation layer was arranged on the cell side.

Next, the top, bottom, left and right of the obtained liquid crystal display device,
A viewing angle with a contrast ratio (Co) ≧ 10 in a diagonal direction of 45 ° to 225 ° and a diagonal direction of 135 ° to 315 ° was measured.
The contrast ratio was measured by displaying white and black images on the liquid crystal display device and then displaying the device (trade name Ez contrast 160D: EL
DIM), the Y value of the XYZ display system at a viewing angle of 0 to 70 °, x, for the front, top, bottom, left and right of the display screen.
Value and y value were measured respectively. Then, the contrast ratio (Y _W / Y _B ) at each viewing angle was calculated from the Y value (Y _W ) of the white image and the Y value (Y _B ) of the black image. The results are shown in Table 2.

(Comparative Example 1) The polarizing plate (trade name: NPF)
Liquid crystal display devices were obtained in the same manner as in Examples 4 to 6, except that -1224DU (manufactured by Nitto Denko) was used instead of the polarizing plate with an optical compensation function obtained in Examples 1 to 3. Then, the viewing angle of the obtained liquid crystal display device was measured in the same manner as in Examples 4 to 6, and the results are shown in Table 2.

(Comparative Example 2) As in Example 1, a thickness of 10
A 0 μm norbornene film was transversely stretched with a tenter at 177 ° C. to obtain an optical compensation A layer having a thickness of 80 μm. The optical compensation A layer and the polarizing plate (trade name: NPF-1224D
U (manufactured by Nitto Denko)) was attached via an acrylic pressure-sensitive adhesive having a thickness of 25 μm. Liquid crystal display devices were obtained in the same manner as in Examples 4 to 6 except that the polarizing plate with the optical compensation A layer thus obtained was used instead of the polarizing plate with the optical compensation function obtained in Examples 1 to 3. Obtained. Then, the viewing angle of the obtained liquid crystal display device was measured in the same manner as in Examples 4 to 6, and the results are shown in Table 2. (Comparative Example 3) Similar to Example 1, the polarizing plate (trade name)
1wt% on NPF-1224DU (Nitto Denko)
5% of polyvinyl alcohol solution is applied at 90 ℃.
It was dried for a minute to form a film having a film thickness of 0.01 μm. Then, the film was subjected to rubbing treatment to form an alignment layer.
Nematic liquid crystal monomer 92 represented by the chemical formula (10)
Weight part, torsional force shown in the chemical formula (38) above 5.5 × 10 ⁻⁴
8 parts by weight of a polymerizable chiral agent of nm ⁻¹ · (wt%) ⁻¹ , 5 parts by weight of a UV polymerization initiator and 300 parts by weight of methyl ethyl ketone are mixed, and this mixture is applied onto the alignment layer to form a spreading layer. did.

The polarizing plate having the spreading layer was heat-treated at 90 ° C. for 1 minute and further UV-crosslinked. As a result, an optical compensation B layer having a thickness of 2.5 μm was formed on the surface of the polarizing plate, and a laminate having a total thickness of 193 μm was attached in a lengthy manner. The polarizing plate with the optical compensation B layer thus obtained was prepared as in Example 1.
Liquid crystal display devices were obtained in the same manner as in Examples 4 to 6 except that the polarizing plates with optical compensation functions obtained in Examples 1 to 3 were used instead.
Then, the viewing angle of the obtained liquid crystal display device was measured in the same manner as in Examples 4 to 6, and the results are shown in Table 2.

[0197]

[Table 2]

As is clear from the results in Table 2, Example 4
The liquid crystal display devices obtained in Examples 6 to 6 were liquid crystal display devices with wide viewing angles. Therefore, it was shown that the polarizing plate with an optical compensation function of the present invention has an excellent optical compensation function.

[0199]

As described above, according to the present invention, it is possible to provide a polarizing plate having an optical compensation function, which is thinner than the optical compensation layer in which two or more stretched polymer films are laminated, and in which an optical compensation function layer is laminated. . It was also shown that the use of the polarizing plate can provide a high-quality liquid crystal display device having excellent visibility.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an example of a polarizing plate with an optical compensation function of the present invention.

FIG. 2 is a perspective view showing a bonding direction of a polarizing layer and an optical compensation layer A.

FIG. 3 is a schematic sectional view of an example of a polarizing plate with an optical compensation function of the present invention.

FIG. 4 is a schematic sectional view of another example of a polarizing plate with an optical compensation function of the present invention.

FIG. 5 is a schematic sectional view of another example of a polarizing plate with an optical compensation function of the present invention.

FIG. 6 is a schematic sectional view of another example of a polarizing plate with an optical compensation function of the present invention.

FIG. 7 is a schematic cross-sectional view of another example of the polarizing plate with an optical compensation function of the present invention.

FIG. 8 is a schematic cross-sectional view of another example of the polarizing plate with an optical compensation function of the present invention.

FIG. 9 is a schematic sectional view of another example of a polarizing plate with an optical compensation function of the present invention.

FIG. 10 is a schematic sectional view of another example of a polarizing plate with an optical compensation function of the present invention.

FIG. 11 is a schematic sectional view of another example of a polarizing plate with an optical compensation function of the present invention.

FIG. 12 is a schematic sectional view of another example of a polarizing plate with an optical compensation function of the present invention.

FIG. 13 is a schematic sectional view of a polarizing plate with an optical compensation function of the present invention in Example 1.

FIG. 14 is a schematic sectional view of a polarizing plate with an optical compensation function of the invention of Example 2.

FIG. 15 is a schematic sectional view of a polarizing plate with an optical compensation function of the present invention in Example 3.

[Explanation of symbols]

1 protective layer 2 Adhesive layer 3 Polarizing layer 4 Optical compensation layer A 5 Optical compensation B layer 6 Alignment layer 7 Support substrate 11 Triacetyl cellulose (TAC) 12 PVA adhesive layer 13 Polarizing layer 14 Optical compensation A layer 15 Optical compensation B layer 16 Alignment layer 18 Acrylic adhesive layer

Continued front page    (72) Inventor Naru Murakami             1-2 1-2 Shimohozumi, Ibaraki City, Osaka Prefecture Nitto             Electric Works Co., Ltd. (72) Inventor Hiroyuki Yoshimi             1-2 1-2 Shimohozumi, Ibaraki City, Osaka Prefecture Nitto             Electric Works Co., Ltd. F-term (reference) 2H049 BA02 BA06 BA24 BA42 BB03                       BB51 BC03 BC22                 2H091 FA08X FA08Z FA11X FA14X                       FB02 FB12 FD06 FD10 GA01                       GA17 HA11 KA10 LA11 LA16

Claims (9)

[Claims] 1. A polarizing plate with an optical compensation function, comprising a polarizing layer and an optical compensation layer, wherein the optical compensation layer comprises an optical compensation A layer containing a polymer film and an optical compensation B layer containing a cholesteric liquid crystal layer. Including polarizing plate with optical compensation function. 2. The polarized light with an optical compensation function according to claim 1, wherein an angle formed by an absorption axis of the polarizing layer and a slow axis of the optical compensation A layer is 85 ° or more and 95 ° or less. Board. 3. The polarizing plate with an optical compensation function according to claim 1, wherein the optical compensation A layer satisfies the conditions represented by the following formulas (I) and (II). 20 (nm) ≤ Re ≤ 300 (nm) (I) 1.2 ≤ Rth / Re (II) [In the above formula, Re (phase difference value in the normal direction) = (nx-ny) · d Rth (thickness Direction retardation value) = (nx−nz) · d (where nx, ny, and nz represent the refractive indices in the X-axis, Y-axis, and Z-axis directions of the optical compensation A layer, respectively). Is the axial direction that exhibits the maximum refractive index in the plane of the optical compensation A layer, the Y axis is the axial direction perpendicular to the X axis in the plane, and the Z axis is
The thickness direction perpendicular to the X-axis and the Y-axis is shown. d represents the thickness of the optical compensation A layer. )] 4. The polarizing plate with an optical compensation function according to claim 1, wherein the selective reflection wavelength region of the cholesteric liquid crystal layer is 350 nm or less. 5. The polarizing plate with an optical compensation function according to claim 1, further comprising at least one of an alignment layer and a base material. 6. The polarizing plate with an optical compensation function according to claim 1, wherein the polymer film is a stretched film or a liquid crystal film. 7. The pressure-sensitive adhesive layer is further included, and the pressure-sensitive adhesive layer is disposed on one surface of the polarizing plate.
7. A polarizing plate with an optical compensation function according to any one of 1 to 6. 8. A liquid crystal comprising a liquid crystal cell and a polarizing plate, wherein the polarizing plate is the polarizing plate according to any one of claims 1 to 7, wherein the polarizing plate is disposed on at least one surface of the liquid crystal cell. Display device. 9. An image display device comprising the polarizing plate according to claim 1.