TWI449971B - Elliptical polarizer, process of producing the polarizer and liquid crystal display device equipped with the polarizer - Google Patents

Description

Ellipsoid polarizing plate, manufacturing method thereof and liquid crystal display device using same

The present invention relates to an elliptically polarizing plate comprising a liquid crystal layer in which a vertical alignment structure is fixed, and a method of manufacturing the same, and a liquid crystal display device using the elliptically polarizing plate.

The retardation film system plays an important role in industrial use in terms of image quality improvement of liquid crystal display devices. The retardation film can be roughly classified into a plastic film extending and a liquid crystal alignment. Because the latter has the potential to achieve a diverse refractive index configuration, it has a more attractive value.

For example, a film having a large refractive index in the film thickness direction is considered to be effective for improving the viewing angle of the liquid crystal display device, and the vertical alignment using the liquid crystal is considered to be a shortcut for such a film. The vertical alignment of the liquid crystal molecules is such that the long-axis molecular direction of the liquid crystal is aligned with respect to the substrate in a substantially vertical direction. The vertical alignment is known as a liquid crystal display device in which liquid crystal is charged in two glass substrates and an electric field is applied, but it is difficult to form such a alignment state into a thin film, and the method pointed out by the conventional report is problematic. For example, after the main chain type polymer liquid crystal is vertically aligned, the film is obtained by fixing the glass (Patent Documents 1 to 3). However, in the vertical alignment, since the polymer is aligned in the film thickness direction, it is presumed that the crack is likely to occur in the in-plane direction. However, in these reports, measures such as material strengthening by crosslinking are used. . In Patent Document 4, it is pointed out that the vertical alignment of the side chain type liquid crystal is immobilized by vitrification, but it is determined that there is a problem in that the strength of the main chain type polymer liquid crystal or more is required.

On the other hand, it has been reported that a polymerizable low molecular liquid crystal is added to a side chain type liquid crystal polymer (Patent Documents 5 to 6). However, since the low molecular liquid crystal system is polymerized alone, the strength of the side chain type liquid crystal polymer is obtained. Reinforcement has limit limits. In Patent Document 7, a material such as a radical polymerizable group or a cationically polymerizable group such as a vinyl ether group or an epoxy group is introduced into the side chain type liquid crystal polymer. However, in general, radical polymerization is inhibited by oxygen, which may result in insufficient polymerization, and if equipment is used to remove oxygen, the apparatus tends to be bulky. Since the vinyl ether group and the epoxy group are not affected by the inhibition of oxygen, although it is advantageous in this point, there is a problem that the ether bond of the vinyl ether group is unstable and easily cracked, and epoxy The introduction of a group into a liquid crystal material is complicated, and it is difficult to obtain a high degree of polymerization when a crosslinking treatment is performed. Further, in order to obtain the vertical alignment, a large amount of non-liquid crystalline structural units are introduced into the liquid crystal material, but there is a concern that the residual liquid crystallinity is retained. As described above, there has been a problem in the manufacture of a conventional vertical alignment film.

[Patent Document 1] Japanese Patent No. 2853064

[Patent Document 2] Japanese Patent No. 3018120

[Patent Document 3] Japanese Patent No. 3078948

[Patent Document 4] Japanese Patent Laid-Open Publication No. 2002-174725

[Patent Document 5] Japanese Patent Laid-Open Publication No. 2002-333524

[Patent Document 6] Japanese Patent Laid-Open Publication No. 2002-333642

[Patent Document 7] Japanese Patent Laid-Open Publication No. 2003-2927

An object of the present invention is to provide a liquid crystal layer having a vertical alignment structure, which is thickened by simplification of a layer structure, and if incorporated in a liquid crystal display device, not only the viewing angle is improved, but also the contrast is improved. An elliptically polarizing plate, and a method of manufacturing the same, and a liquid crystal display device using the same.

In order to solve the above problems, the inventors of the present invention have found out that the above object can be attained by the elliptically polarizing plate shown below, a method for producing the same, and a liquid crystal display device using the same, and the present invention has been completed.

In other words, the elliptically polarizing plate according to the first aspect of the invention is a vertical alignment liquid crystal layer in which the liquid crystal composition having a positive uniaxiality is vertically aligned in a liquid crystal state, and then the alignment is fixed, and has a phase difference function. a retardation film; and a linear polarizing plate having a laminated structure in which only one surface of the polarizing element is protected by a light-transmitting protective film; and an elliptically polarizing plate comprising the following (A) or (B); Laminated construction:

(A) light transmissive protective film / polarizing element / retardation film / vertical alignment liquid crystal layer;

(B) Translucent protective film / polarizing element / vertical alignment liquid crystal layer / retardation film.

The elliptically polarizing plate according to the first aspect of the invention, wherein the vertical alignment liquid crystal layer contains a liquid crystalline composition containing a side chain type liquid crystalline polymer compound having an oxetane group, and is in a liquid crystal state. After the vertical alignment is performed, the oxetane group is reacted to form the vertically aligned liquid crystal layer fixed in the vertical alignment.

The elliptically polarizing plate according to the first or second aspect of the invention, wherein the vertical alignment liquid crystal layer satisfies the following [1] and [2]:

[1]0nm≦Re1≦20nm

[2]-500nm≦Rth1≦-30nm

(Re1 is the retardation value in the vertical alignment liquid crystal layer; Rth1 is the retardation value in the thickness direction of the vertical alignment liquid crystal layer. Re1 and Rth1 are Re1 = (Nx1 - Ny1) × d1 [nm], Rth1, respectively. = (Nx1 - Nz1) × d1 [nm]. Further, d1 is the thickness of the above-mentioned vertical alignment liquid crystal layer, Nx1 and Ny1 are the main refractive indices in the vertical alignment liquid crystal layer, and Nz1 is the main refractive index in the thickness direction. And Nz1>Nx1≧Ny1.)

The elliptically polarizing plate according to the first to third aspects of the invention, wherein the retardation film satisfies the following [3] and [4]:

[3]20nm≦Re2≦200nm

[4]0nm≦Rth2≦30nm

(Re2 refers to the retardation value in the plane of the retardation film; Rth2 refers to the retardation value in the thickness direction of the retardation film. Re2 and Rth2 refer to Re2=(Nx2-Ny2)×d2[nm] and Rth2=, respectively. (Nx2-Nz2) × d2 [nm], d2 is the thickness of the retardation film, Nx2 and Ny2 are the principal refractive indices in the plane of the retardation film, and Nz2 is the principal refractive index in the thickness direction, and Nx2>Ny2≧Nz2.)

According to a fifth aspect of the invention, the elliptically polarizing plate according to the first to fourth aspects of the invention is obtained by laminating at least one or more optical films.

The elliptically polarizing plate according to the first aspect of the invention, wherein the translucent protective film is a cellulose triacetate or a cycloolefin polymer.

The elliptically polarizing plate according to the first to sixth aspects of the invention, wherein the total thickness is 175 μm or less.

The method for producing an elliptically polarizing plate according to the eighth aspect of the invention is at least the following steps:

(1) The light-transmitting protective film is bonded to the polarizing element via the adhesive layer 1 to obtain a first step of forming the laminated body (I) from the light-transmitting protective film/adhesive layer 1/polarizing element;

(2) forming a layer of a liquid crystal composition exhibiting a positive uniaxiality on the retardation film, and performing vertical alignment of the layer, and then forming a vertical alignment liquid crystal layer to which the alignment is fixed, thereby obtaining a retardation film/vertical alignment The liquid crystal layer constitutes the second step of the layered body (II);

(3) The retardation film side of the laminated body (II) is bonded to the polarizing element side of the laminated body (I) via the adhesive layer 2 to obtain a light-transmitting protective film/adhesive layer 1/polarized light. The third step of forming the elliptically polarizing plate by the element/adhesive layer 2/phase difference film/vertical alignment liquid crystal layer.

The method for producing an elliptically polarizing plate according to the ninth invention is at least via the following steps:

(1) a step of bonding a light-transmitting protective film to a polarizing element via an adhesive layer 1 to obtain a laminated body (I) comprising a light-transmitting protective film/adhesive layer 1/polarizing element;

(2) forming a layer of a liquid crystal composition exhibiting a positive uniaxiality on the retardation film, and performing vertical alignment of the layer, and then forming a vertical alignment liquid crystal layer to which the alignment is fixed, thereby obtaining a retardation film/vertical alignment The liquid crystal layer constitutes the second step of the layered body (II);

(3) The vertical alignment of the layered product (II) is directed to the liquid crystal phase side, and is bonded to the polarizing element side of the layered product (I) via the adhesive layer 2 to obtain a light-transmitting protective film/adhesive layer 1/ The polarizing element/adhesive layer 2/vertical alignment liquid crystal layer/retardation film constitutes the third step of the elliptically polarizing plate.

The method for producing an elliptically polarizing plate according to a tenth aspect of the invention is at least the following steps:

(1) The light-transmitting protective film is bonded to the polarizing element via the adhesive layer 1 to obtain a first step of forming the laminated body (I) from the light-transmitting protective film/adhesive layer 1/polarizing element;

(2) forming a layer of a liquid crystal composition exhibiting a positive uniaxiality on the alignment substrate, and then vertically aligning the layer, and then forming a vertical alignment liquid crystal layer to which the alignment is fixed, thereby obtaining an alignment substrate/vertical alignment liquid crystal layer The second step of constituting the layered body (III);

(3) The vertical alignment liquid crystal layer side of the laminate (III) is bonded to the retardation film via the adhesive layer 2, and then the alignment substrate is peeled off, and the vertical alignment liquid crystal layer is transferred onto the retardation film to obtain a third step of forming the layered body (IV) from the retardation film/adhesive layer 2/vertical alignment liquid crystal layer;

(4) The retardation film side of the layered product (IV) is bonded to the polarizing element side of the layered product (I) via the adhesive layer 3 to obtain a light-transmitting protective film/adhesive layer 1/polarizing element. / The adhesive layer 3 / retardation film / adhesive layer 2 / vertical alignment liquid crystal layer constitutes the fourth step of the elliptically polarizing plate.

The method for producing an elliptically polarizing plate according to the eleventh aspect of the invention is at least the following steps:

(1) The light-transmitting protective film is bonded to the polarizing element via the adhesive layer 1 to obtain a first step of forming the laminated body (I) from the light-transmitting protective film/adhesive layer 1/polarizing element;

(2) forming a layer of a liquid crystal composition exhibiting a positive uniaxiality on the alignment substrate, and then vertically aligning the layer, and then forming a vertical alignment liquid crystal layer to which the alignment is fixed, thereby obtaining an alignment substrate/vertical alignment liquid crystal layer The second step of constituting the layered body (III);

(3) After the vertical alignment liquid crystal layer side of the layered product (III) is bonded to the retardation film via the adhesive layer 2, the alignment substrate is peeled off, and the vertical alignment liquid crystal layer is transferred onto the retardation film. Obtaining a third step of forming the laminate (IV) from the retardation film/adhesive layer 2/vertical alignment liquid crystal layer;

(4) The vertical alignment liquid crystal layer side of the laminate (IV) is bonded to the polarizing element side of the laminate (A) via the adhesive layer 3 to obtain a light-transmitting protective film/adhesive layer 1/ The polarizing element/adhesive layer 3/vertical alignment liquid crystal layer/adhesive layer 2/retardation film constitutes the fourth step of the elliptically polarizing plate.

In the liquid crystal display device of the twelfth aspect of the invention, the elliptically polarizing plates described in the first to seventh aspects of the invention are disposed on at least one surface of the liquid crystal cell.

The liquid crystal display device according to the twelfth aspect, wherein the liquid crystal cell is a VA liquid crystal cell or an IPS liquid crystal cell.

The elliptically polarizing plate of the present invention using a vertical alignment liquid crystal layer, in particular, when disposed in a vertical alignment type liquid crystal display device, can not only enlarge the viewing angle, but the vertical alignment type liquid crystal display device can display brightly and can perform high contrast in all directions. Display.

Hereinafter, the present invention will be described in detail.

The elliptically polarizing plate of the present invention will be described.

The elliptically polarizing plate of the present invention is at least a vertical alignment liquid crystal layer in which a liquid crystal composition having at least a positive uniaxiality is vertically aligned in a liquid crystal state, and then the alignment is fixed; a retardation film having a phase difference function And a linear polarizing plate having a laminated structure in which only one surface of the polarizing element is protected by a light-transmitting protective film. In the present invention, when the vertical alignment liquid crystal layer to which the vertical alignment is fixed is obtained, the liquid crystal composition layer formed on the alignment film on the retardation film, the alignment substrate, or the alignment substrate is vertically aligned. It can be obtained by fixing the alignment state by cooling with light and/or heat treatment as needed. The liquid crystal material used for the liquid crystal composition may be formed of a low molecular liquid crystal compound, a liquid crystalline polymer compound, or a mixture thereof before being added to a positive uniaxial liquid crystal material capable of vertical alignment. material.

The above-mentioned low molecular liquid crystal compound can be easily immobilized by bonding a compound which reacts with a reactive group which is reacted by light or heat, and is preferable. The reactive group is preferably, for example, a vinyl group, a (meth)acrylonitrile group, a vinyloxy group, an oxiranyl group, an oxetanyl group or an aziridine group, and other conditions may be used depending on the reaction conditions and the like. The reactive group is, for example, an isocyanate group, a hydroxyl group, an amine group, an acid anhydride group, a carboxyl group or the like.

The liquid crystalline polymer compound may be a main chain type liquid crystalline polymer compound or a side chain type liquid crystalline polymer compound, and any of them may be used.

The main chain type liquid crystalline polymer compound may, for example, be polyester, polyester quinone, polyamine or polycarbonate. Among them, from the viewpoints of ease of synthesis, orientation, glass transition point, and the like, a liquid crystalline polyester is preferable.

The side chain type liquid crystalline polymer compound may, for example, be a poly(meth)acrylate, a polymalonate or a polyoxyalkylene. It is preferable that these liquid crystalline polymer compounds are bonded to the above reactive group. Among them, a poly(meth)acrylate having a reactive group represented by the following general formula (1) is preferably bonded.

[Chemical 1]

In the formula (1), R ³ means independently hydrogen or methyl, respectively; R ⁴ means independently hydrogen, methyl, ethyl, butyl, hexyl, octyl, decyl, decyl, dodecane, respectively. Base, methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, decyloxy, dodecyloxy, cyano, bromo, Chlorine, fluorine or carboxyl; R ⁵ means independently hydrogen, methyl or ethyl; R ⁶ means a hydrocarbon group of 1 to 24; L ² means an independent single bond, -O-, - O-CO-, -CO-O-, -CH=CH- or -C≡C-; p means an integer from 1 to 10; q means an integer from 0 to 10; a, b, c, d, e And f means the molar ratio of each unit in the polymer (a+b+c+d+e+f=1.0, but c+d+e=0).

The molar ratio of each component of the side chain type liquid crystalline polymer compound represented by the formula (1) is a+b+c+d+e+f=1.0, and cannot be c+d+e=0, and must be Liquid crystal. Under the premise of satisfying the requirements, the molar ratio of each component can be arbitrary, preferably as follows:

a: preferably 0~0.80, especially 0.05~0.50

b: preferably 0~0.90, especially 0.10~0.70

c: preferably 0~0.50, especially 0.10~0.30

d: preferably 0~0.50, especially 0.10~0.30

e: preferably 0~0.50, especially 0.10~0.30

f: preferably 0~0.30, especially 0.01~0.10

It is not necessary to have all of the six components present before the respective components in the poly(meth) acrylate satisfy the above conditions. If it exceeds these ranges, it is preferably avoided because the liquid crystallinity is insufficient or the reactivity of the oxetane group is insufficient.

Further, R ^{4 is} preferably, for example, hydrogen, methyl, butyl, methoxy, cyano, bromo, or fluoro, etc., particularly preferably hydrogen, methoxy or cyano, and L ^{2 is} preferably For example, a single bond, -O-, -O-CO- or -CO-O-, R ^{6 is} preferably a hydrocarbon group having 2, 3, 4, 6, 8, or 18 carbon atoms.

In addition, the side chain type liquid crystalline polymer compound represented by the general formula (1) changes the complex refractive index by the molar ratio and the alignment form of each component a to f, and the complex refractive index when the alignment is employed. Preferably, it is 0.001 to 0.300, especially 0.05 to 0.25.

Each (meth)acrylic compound which satisfies each component of the above-mentioned side chain type liquid crystalline polymer compound can be obtained by an ordinary organic chemical synthesis method. The (meth)acrylic compound having an oxetane group, for example, by using an ether synthesis of Williamson or an ester synthesis using a condensing agent, and having a site having an oxetane group and having The (meth)acrylic group is bonded to a (meth)acrylic acid having an oxetanyl group having two reactive functional groups such as an oxetane group and a (meth)acryl group. Compound.

The side chain type liquid crystalline polymer compound can be easily copolymerized by radical polymerization or anionic polymerization by using a (meth)acryl group of each (meth)acrylic acid compound obtained by the above method in accordance with each component. Synthetic. The polymerization conditions are not particularly limited, and usual conditions can be employed.

Examples of the radical polymerization are, for example, dissolving a (meth)acrylic compound conforming to each component in a solvent such as dimethylformamide (DMF) or diethylene glycol dimethyl ether, and such as 2, 2 A method in which an azo-isoisobutyronitrile (AIBN) or a benzamidine peroxide (BPO) is used as a starter and is reacted at 60 to 120 ° C for several hours. Further, in order to stably exhibit a liquid crystal phase, such as copper(I)/2,2'-bipyridine, or 2,2,6,6-tetramethylpiperidine oxide ‧ free radical (TEMPO) The system is the initiator and the living radical polymerization is carried out, and the method of controlling the molecular weight distribution is also effective. These free radical polymerizations must be carried out under deoxygenated conditions.

An example of anionic polymerization is to dissolve a (meth)acrylic compound conforming to each component in a solvent such as tetrahydrofuran (THF), and start with a strong base such as an organolithium compound, an organic sodium compound, or a Grignard reagent. The method of carrying out the reaction. Further, living anion polymerization is carried out by optimizing the initiator and the reaction temperature, and the molecular weight distribution is also controlled. These anionic polymerizations must be carried out under dehydration and deoxygenation conditions.

The weight average molecular weight of the side chain type liquid crystalline polymer compound is preferably from 1,000 to 200,000, particularly preferably from 3,000 to 50,000. If it is outside this range, there is a case where the strength is insufficient or the alignment property is deteriorated, so it is preferable to avoid it.

In the present invention, the liquid crystal material or the liquid crystal composition comprising the low molecular liquid crystal compound, the liquid crystalline polymer compound, or the mixture thereof preferably contains the dioxetane represented by the following general formula (2). Alkane compound.

[Chemical 2]

In the formula (2), R ⁷ means independently hydrogen, methyl or ethyl; respectively; L ³ means an independent single bond or -(CH ₂ )n- (n is an integer of 1 to 12); X ¹ Respectively means an independent single bond, -O-, -O-CO-, or -CO-O-; M ¹ means any one of formula (3) or formula (4), and formula (3) And P ¹ in the formula (4) means a group independently selected from the formula (5); P ² means a group selected from the formula (6); and L ⁴ means an independent single bond, -CH, respectively. =CH-, -C≡C-, -O-, -O-CO-, or -CO-O-.

-P ¹ -L ⁴ -P ² -L ⁴ -P ¹ - (3)

-P ¹ -L ⁴ -P ¹ - (4)

[Chemical 3]

[Chemical 4]

In the formulae (5) and (6), Et means ethyl, iPr means isopropyl, nBu means n-butyl, and tBu means tributyl.

More specifically, from the viewpoint of M ¹ , the linking groups to which the left and right oxetanyl groups are bonded may be different (asymmetric) or the same (symmetrical), and in particular, 2 The case where L ³ is different or the liquid crystal property cannot be exhibited due to the structure of other link groups is not limited in use.

The compound represented by the general formula (2) is exemplified by a combination of M ¹ , L ³ and X ¹ , and various compounds can be exemplified, and preferably, for example, the following compounds are used:

[Chemical 5]

These compounds can be synthesized in accordance with ordinary synthetic methods in organic chemistry, and the synthesis method is not particularly limited.

At the time of the synthesis, since the oxetane group has cationic polymerizability, it is judged that under a strong acidic condition, side reactions such as polymerization and ring opening will occur, and it is necessary to select reaction conditions. Further, the oxetane group is less likely to cause a side reaction than the oxirane group or the like which is a cationically polymerizable functional group. Further, various compounds such as an alcohol, a phenol, a carboxylic acid, and the like may be successively reacted, and an appropriate protecting group may be considered.

More specific synthetic methods include, for example, hydroxybenzoic acid as a starting compound, and an oxetane linkage according to Williamson's ether synthesis method, etc., and then the obtained compound is applied to the present invention. a diol which is bonded by a condensation method such as an acid chlorination method or a carbodiimide or the like, or a hydroxy group of a hydroxybenzoic acid is protected in advance by a suitable protecting group. After the diol of the invention is condensed, the protecting group is removed to form a compound having an appropriate oxetane group (oxetane compound), for example, a haloalkyl oxetane or the like is reacted with a hydroxyl group. Method etc.

The reaction system of the oxetane compound and the hydroxyl group may be selected according to the form and reactivity of the compound to be used, and the reaction temperature is usually -20 ° C to 180 ° C, preferably 10 ° C to 150 ° C. The reaction time is selected from 10 minutes to 48 hours, preferably from 30 minutes to 24 hours. If it exceeds these ranges, the reaction does not proceed sufficiently or a side reaction occurs, and thus it is preferable to avoid it. Further, the mixing ratio of the two is preferably 1 to 1 equivalent of the hydroxyl group, and is preferably 0.8 to 1.2 equivalents of the oxetane compound.

The liquid crystal material used in the present invention may contain various compounds which can be mixed, in addition to the above-mentioned low molecular liquid crystal compound and liquid crystalline polymer compound, without being damaged by liquid crystallinity. The compound which may be contained is, for example, a compound having a cationically polymerizable functional group such as an oxetane group, an epoxy group or a vinyloxy group; various polymer materials having a film forming ability; and various low liquid crystal properties. A molecular liquid crystal compound or a polymer liquid crystal compound. When the side chain type liquid crystalline polymer compound is used as a composition, the proportion of the side chain type liquid crystalline polymer compound in the entire composition is 10% by mass or more, preferably 30% by mass or more. Especially preferably 50% by mass or more. When the content of the side chain type liquid crystalline polymer compound is less than 10% by mass, the film forming ability is insufficient, the polymerizable group concentration in the composition is lowered, and the mechanical strength after polymerization is insufficient, so that it is preferably avoided.

Further, after the liquid crystal material is subjected to an alignment treatment, for example, in the case of a reactive oxetane group having a reactive group, the liquid crystal state can be immobilized by crosslinking by cationic polymerization. Therefore, it is preferable that the liquid crystal material contains a photocation generator and/or a thermal cation generator which generate cations by external stimuli such as light or heat. Further, various sensitizers may be used in combination as needed.

The term "photocation generating agent" refers to a compound which generates a cation by irradiation with light of a suitable wavelength, and examples thereof include an organic phosphonium salt system, an onium salt system, and an onium salt system. As the ion pair of these compounds, a phosphonium salt, a phosphate ester, a borate or the like is preferably used. Specific examples of the compound include Ar ₃ S+SbF ₆ ^- , Ar ₃ P ⁺ BF ₄ ^- , Ar ₂ I+PF ₆ ^- (wherein Ar is a phenyl group or a substituted phenyl group). In addition, it is also possible to use, for example, sulfonate esters, three Classes, diazomethanes, β-ketooximes, imidosulfonates, benzoin sulfonates, and the like.

The "thermal cation generating agent" refers to a compound which generates a cation by heating to a suitable temperature, and examples thereof include a benzyl sulfonium salt, a benzyl ammonium salt, a benzyl pyridinium salt, and a benzyl sulfonium salt. Bismuth salts, carboxylic acid esters, sulfonates, amine quinones, antimony pentachloride-chloroacetamidine complex, diaryl sulfonium salt - dibenzyloxy copper, boron halide - tertiary Amine adducts, etc.

The amount of the cation generating agent to be added to the liquid crystal material varies depending on the structure of the liquid crystal original portion and the spacer portion of the liquid crystalline polymer compound to be used, the oxetane group equivalent, and the liquid crystal alignment condition. It is not possible to generalize, but it is usually set to be in the range of 100 ppm by mass to 20% by mass, preferably 1,000 ppm by mass to 10% by mass, particularly preferably 0.2% by mass to 7% by mass, based on the liquid crystalline polymer compound. . When the amount is less than 100 ppm by mass, the amount of the generated cation is insufficient, and there is a possibility that the polymerization may not be carried out. On the other hand, if it is more than 20% by mass, the decomposition residue of the cation generating agent remaining in the alignment liquid crystal layer may be contained. If it increases, there is a possibility that the light resistance is deteriorated, so it is best to avoid it.

Next, the alignment substrate will be described.

When the retardation film is used as the alignment substrate, even if the retardation film can directly have a vertical alignment ability to the liquid crystal material, if it is not the case, it is preferable to carry out the alignment treatment described later (alignment film formation). , friction treatment, etc.).

The alignment substrate other than the retardation film preferably has a smooth plane, and may be, for example, a film or sheet made of an organic polymer material, or a glass plate, a metal plate or the like. From the viewpoint of cost and continuous productivity, it is preferable to use a material composed of an organic polymer. Examples of the organic polymer material may be exemplified by, for example, polyvinyl alcohol, polyimide, polyoxyxylene, polyphenylene sulfide, polyfluorene, polyether ketone, polyetheretherketone, polyarylester, polyparaphenylene. A polyester-based polymer such as ethylene dicarboxylate or polyethylene naphthalate; a cellulose-based polymer such as cellulose diacetate or cellulose triacetate; a polycarbonate polymer, polymethyl methacrylate, etc. A film composed of a transparent polymer such as an acrylic polymer. Further, examples thereof include styrene polymers such as polystyrene, acrylonitrile ‧ styrene copolymer; olefin polymers such as polyethylene, polypropylene, ethylene ‧ propylene copolymer; polycycloolefin, vinyl chloride A film composed of a transparent polymer such as a phthalamide polymer such as a polymer, a nylon or an aromatic polyamine. These may also be blends.

In order to stably obtain the vertical alignment using the liquid crystal material, the material constituting the substrates preferably has a long chain (usually a carbon number of 4 or more, preferably 8 or more) alkyl group or a fluorinated hydrocarbon group, or the substrate surface is provided with the An equivalent compound layer. Further, the organic polymer materials may be used alone as a substrate, or may be formed on other substrates.

The step of forming a compound layer (alignment film) having a long chain (usually a carbon number of 4 or more, preferably 8 or more) of an alkyl group or a fluorinated hydrocarbon group will be described.

The material forming the alignment film is preferably applied in a solution state from the viewpoint of controlling the film thickness and surface properties. This solution can be suitably carried out using a solvent capable of dissolving the material. For example, a solvent for preparing an alkyl modified polyvinyl alcohol (PVA) solution is taken up before being a solvent capable of dissolving the PVA, and the rest is not particularly limited, and usually, for example, water, or methanol, ethanol, or isopropyl alcohol can be used. A lower alcohol such as an alcohol or a mixture thereof.

Further, various additives which do not adversely affect coating and liquid crystal alignment at the time of dissolution can be added. In addition, heating can be performed to promote dissolution.

The coating method to be used for forming the alignment film on the substrate is not particularly limited, and in particular, a coating method for the large-area alignment film may be, for example, a rubber plate rotary printing method using a soft resin plate, and distribution. Device method, gravure coating method, micro gravure method, screen printing method, blade coating method, die coating method, and the like. Among these, a gravure coating method, a blade coating method, and a die coating method are preferable.

The coated alignment film is dried as needed. The drying temperature is usually in the case of PVA, although the heat resistance is limited, but it may be above the purpose. Generally, it is set to 50 ° C ~ 180 ° C, preferably 80 ° C ~ 160 ° C. In addition, the drying time is not particularly limited, and is usually set to 10 seconds to 60 minutes, preferably 1 minute to 30 minutes. The relative movement speed of the dried film and the dry wind is preferably from 60 m/min to 1200 m/min in terms of the relative anemometer.

In the field of liquid crystals, rubbing treatment in which a substrate is wiped in a certain direction by a cloth or the like is generally employed. However, the vertical alignment liquid crystal layer used in the present invention is an alignment structure which does not substantially generate in-plane anisotropy. Therefore, it is not necessary to perform a rubbing treatment. However, in order to suppress the occurrence of plucking when the liquid crystal material is applied, it is preferable to perform a light rubbing treatment. The important set value for standardizing friction conditions is the weekly speed ratio. This ratio refers to the ratio of the cloth moving speed to the substrate moving speed when the substrate is wiped while the rubbing cloth is wound around the roll and rotated. In the present invention, the "light rubbing treatment" generally means a peripheral speed ratio of 50 or less, preferably 25 or less, particularly preferably 10 or less. When the peripheral speed ratio is greater than 50, the friction effect is too strong, and the liquid crystal material cannot be completely vertically aligned, and there is a possibility that the alignment is tilted from the vertical direction to the in-plane direction.

Next, a method of manufacturing the vertical alignment liquid crystal layer used in the present invention will be described. The method for manufacturing the liquid crystal layer is not limited to these. For example, the liquid crystal material may be spread on the retardation film or the alignment substrate, and the liquid crystal material may be aligned, and then subjected to light irradiation and/or heat treatment. The alignment state can be obtained by immobilization.

A method of forming a liquid crystal material layer by developing a liquid crystal material on a retardation film or an alignment substrate, such as a method of directly applying a liquid crystal material to a alignment substrate in a molten state, or applying a solution of a liquid crystal material to an alignment substrate After the above, the coating film is dried and the solvent is distilled off.

The solvent to be used in the preparation of the relevant solution is prepared before the solvent which can dissolve the liquid crystal material of the present invention and can be distilled off under appropriate conditions, and the rest is not particularly limited, and it is generally preferred to use, for example, acetone, methyl ethyl ketone or the like. Ketones such as phorone and cyclohexanone; ether alcohols such as butoxyethanol, hexyloxyethanol and methoxy-2-propanol; ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, etc. Alcohol ethers; esters such as ethyl acetate, ethyl lactate, γ-butyrolactone; phenols such as phenol and chlorophenol; N,N-dimethylformamide, N,N-dimethylacetamide And guanamine such as N-methylpyrrolidone; halogen such as chloroform, tetrachloroethane or dichlorobenzene; or a mixture of these. Further, in order to form a uniform coating film on the alignment substrate, a surfactant such as a surfactant, an antifoaming agent, a leveling agent, a coloring agent or the like may be added to the solution.

In addition, in order to facilitate the aligning of the alignment of the liquid crystalline polymer compound, it is possible to add, for example, a polymerizable group bonded to a liquid crystalline polymer compound in one molecule to have the same reactivity. Two or more kinds of low molecular compounds (whether liquid crystal or non-liquid crystalline), or various compounds capable of improving adhesion.

Regardless of the method of directly applying the liquid crystal composition or the method of applying the solution, the relevant coating method is based on the method of ensuring the uniformity of the coating film, and the rest is not particularly limited. A well-known method is employed. For example, a spin coating method, a die coating method, a curtain coating method, a dip coating method, a roll coating method, and the like.

In the method of applying a solution of the liquid crystal composition, it is preferred to add a drying step for removing the solvent after coating. The drying step is based on a method capable of maintaining the uniformity of the coating film, and the rest is not particularly limited, and a known method can be employed. For example: heater (furnace), hot air blowing, etc.

The thickness of the liquid crystal layer depends on the liquid crystal cell and various optical parameters. Therefore, it is usually not particularly limited, and is usually 0.2 μm to 10 μm, preferably 0.3 μm to 5 μm, and particularly preferably 0.5 μm to 2 μm. When the film thickness is thinner than 0.2 μm, there is a possibility that a sufficient viewing angle improvement or brightness enhancement effect may not be obtained. On the other hand, if it exceeds 10 μm, there is a fear that unnecessary coloring may occur in the liquid crystal display device.

Next, the liquid crystal composition layer formed on the alignment substrate is formed into a liquid crystal alignment by a heat treatment or the like, and then cured by light irradiation and/or heat treatment to be immobilized. The initial heat treatment is performed by heating to the liquid crystal phase display temperature range of the liquid crystal composition to be used, whereby the liquid crystal composition can be aligned by the self-alignment ability originally possessed by the liquid crystal composition. The heat treatment conditions are based on the liquid crystal phase behavior temperature (transfer temperature) of the liquid crystal composition used, and have different optimum conditions and limit values, and thus cannot be generally set, and are usually set at 10 to 250 ° C, preferably 30 In the range of °C to 160 °C, the temperature above the glass transition point (Tg) of the liquid crystal composition is preferably preferably a heat treatment at a temperature higher than 10 ° C and higher than Tg. If the temperature is too low, there is a possibility that the liquid crystal alignment cannot be sufficiently performed. On the other hand, if it is at a high temperature, there is a possibility that the cationically polymerizable reactive group or the alignment substrate in the liquid crystal composition may be adversely affected. In addition, the relevant heat treatment time is usually set within a range of 3 seconds to 30 minutes, preferably 10 seconds to 20 minutes. If the heat treatment time is shorter than 3 seconds, there is a possibility that the liquid crystal alignment is not sufficiently completed. On the other hand, if the heat treatment time exceeds 30 minutes, since productivity is deteriorated, it is preferable to avoid it in any case.

After the liquid crystal alignment is formed by a method such as heat treatment on the liquid crystal composition layer, the liquid crystal composition is cured by reacting the liquid crystal composition with the oxetane group in the composition while maintaining the liquid crystal alignment state. The purpose of the hardening step is to use a hardening (crosslinking) reaction for the completed liquid crystal alignment, and to fix the liquid crystal alignment state to be a solid film.

Since the liquid crystalline composition used in the present invention has a polymerizable oxetane group, a cationic polymerization initiator (cation generator) is preferably used in the polymerization (crosslinking) as described above. Further, it is preferred to use a photocationic generator in comparison with the use of a thermal cation generator in the polymerization initiator.

When a photocationic cation generating agent is used, if the photothermal cation generating agent is added, the steps up to the heat treatment for liquid crystal alignment are carried out under dark conditions (light blocking conditions in which the photocation generating agent does not dissociate). The liquid crystal composition does not harden until the alignment stage, and has sufficient fluidity, so that liquid crystal alignment can be performed. Then, the liquid crystal composition layer is hardened by irradiating light of a light source that emits light of a suitable wavelength to generate a cation.

The method of light irradiation is to irradiate light having a spectrum such as a metal halide lamp, a high pressure mercury lamp, a low pressure mercury lamp, a xenon lamp, an arc lamp, a laser or the like in an absorption wavelength region of the photocation generator used, and the photocation will be generated. The agent is cracked. The irradiation amount per square centimeter is usually set to be in the range of 1 to 2000 mJ, preferably 10 to 1000 mJ, based on the integral irradiation amount. However, the case where the absorption region of the photocation generator is significantly different from the spectrum of the light source, or the liquid crystal composition itself has the ability to absorb the absorption light from the light source, is not limited thereto. In these cases, a method of mixing, for example, a suitable photosensitizer or two or more photocation generators having different absorption wavelengths may be employed.

The temperature at the time of light irradiation must be set to a temperature range in which the liquid crystal composition becomes a liquid crystal alignment. Further, in order to sufficiently obtain the hardening effect, it is preferred to perform light irradiation at a temperature higher than Tg of the liquid crystal composition.

The liquid crystal composition layer obtained by the above steps became a sufficiently strong film. Specifically, the liquid crystal element is three-dimensionally bonded by the hardening reaction, and the heat resistance (the upper limit temperature of the liquid crystal alignment retention) is improved not only before and after the curing, but also related to scratch resistance and wear resistance. The mechanical strength such as crack resistance can be greatly improved.

Further, the alignment substrate is optically non-isotropic, or the obtained liquid crystal film is opaque in the final target wavelength region, or when the alignment substrate film thickness is too thick, but the practical use does not cause hindrance and the like. In other cases, in the form formed on the alignment substrate, a substrate on the middle of the wavelength region to be used for the target or a form on the stretched film having a phase difference function can be used. The transfer method can employ a well-known method. In the liquid crystal film layer, a substrate different from the alignment substrate is laminated on the liquid crystal film layer via an adhesive or an adhesive, and then from the laminate, as described in JP-A-H05-333313. A method of peeling off the alignment substrate, and transferring only the liquid crystal layer.

The adhesive or the adhesive to be used for the transfer may be an optical grade, and the rest is not particularly limited, and those commonly used such as acrylic, epoxy, and urethane may be used. substance.

According to the vertical alignment liquid crystal layer obtained as described above, the optical phase difference of the liquid crystal layer can be quantified by performing measurement at an obliquely perpendicular incidence angle. In the case of a vertically aligned liquid crystal layer, the phase difference is symmetrical with respect to normal incidence. There are several methods for measuring the optical phase difference, and for example, an automatic birefringence measuring device (manufactured by Oji Scientific Instruments Co., Ltd.) and a polarizing microscope can be used. The vertical alignment liquid crystal layer will be black between the polarized elements that are orthogonally polarized. Based on this, an evaluation of vertical alignment is performed.

The vertical alignment liquid crystal layer used in the present invention has a liquid crystal layer thickness of d1, a main refractive index in the liquid crystal layer of Nx1 and Ny1, a main refractive index in the thickness direction of Nz1, and Nz1>Nx1≧. In the case of Ny1, the in-plane retardation value (Re1=(Nx1-Ny1)×d1[nm]) and the retardation value in the thickness direction (Rth1=(Nx1-Nz1)×d1[nm]) preferably satisfy the following formula [ 1] and [2]:

[1]0nm≦Re1≦20nm

[2]-500nm≦Rth1≦-30nm

Since the Re1 value and the Rth1 value of the optical parameters of the vertical alignment liquid crystal layer depend on the mode of the liquid crystal display device and various optical parameters, it cannot be said in general, and the in-plane retardation value (Re1) is usually controlled with respect to the 550 nm monochromatic light. In the range of 0 nm to 20 nm, preferably 0 nm to 10 nm, particularly preferably in the range of 0 nm to 5 nm, and the retardation value (Rth1) in the thickness direction is usually controlled at -500 nm to -30 nm, preferably -400 nm to -50 nm, especially -400nm~-100nm is preferred.

By setting the Re1 value and the Rth1 value within the above range, the viewing angle improving film of the liquid crystal display device can expand the viewing angle while performing tone correction of the liquid crystal display. When the Re1 value is larger than 20 nm, there is a possibility that the front characteristics of the liquid crystal display device are deteriorated due to the influence of a large front surface difference value. Further, when the Rth1 value is larger than -30 nm or smaller than -500 nm, there is a fear that a sufficient viewing angle improvement effect or a possibility of unnecessary coloring when obliquely viewing is not obtained.

Further, the vertical alignment liquid crystal layer preferably satisfies the conditions shown in the following [5]:

[5]-0.5≦Δn≦-0.0005(Δn=Nx1-Nz1)

Further, in view of the improvement in productivity and the thinning of the elliptically polarizing plate including the vertical alignment liquid crystal layer, it is preferable to use -0.2 ≦ Δn ≦ - 0.005.

Even if the vertical alignment liquid crystal layer is replaced, the optical anisotropic element having a positive uniaxiality in the thickness direction is changed to the use of the extension film, since there is still a limit in the extension in the thickness direction, and thus the phase difference in the thickness direction cannot be controlled widely. Within the scope. Further, although a method in which a long film is thermally contracted by a heat shrinkable film and extends in the thickness direction is used, the thickness of the film obtained by a complex refractive index of 0.003 or less in the thickness direction is about 50 to 100 μm, and the thickness is relatively small. The original long strip film has increased, and it is difficult to meet the requirements for the overall thinning of the elliptically polarizing plate due to the thinning requirements of the liquid crystal display device.

The film thickness of the elliptically polarizing plate is preferably 175 μm or less, and particularly preferably 150 μm or less, from the viewpoint of the demand for thinning in recent years.

The linear polarizing plate constituting the elliptically polarizing plate of the present invention is provided with a light-transmitting protective film only on one side of the polarizing element. The polarizing element to be used is not particularly limited, and various materials can be used, and for example, a partially saponified film such as a polyvinyl alcohol film, a partially formalized polyvinyl alcohol film, or an ethylene vinyl acetate copolymer system can be used. On the hydrophilic polymer film, a dichroic substance such as iodine or a dichroic dye is adsorbed, and a uniaxially stretched substance or a dehydrated material of polyvinyl alcohol or a dehydrochlorinated product of polyvinyl chloride is adsorbed. An olefinic alignment film or the like. Among these, it is preferable to use a polyvinyl alcohol-based film to stretch and adsorb a dichroic material (iodine or dye) and to perform alignment. The thickness of the polarizing element is not particularly limited, and is generally about 5 to 80 μm.

The polyvinyl alcohol-based film is dyed by iodine and subjected to uniaxially extending polarizing elements. For example, polyvinyl alcohol is immersed in an aqueous iodine solution and dyed, and then produced by stretching 3 to 7 times the original length. If necessary, it may be immersed in an aqueous solution such as boric acid, potassium iodide or the like. Further, if necessary, the polyvinyl alcohol-based film may be immersed in water and subjected to water washing before dyeing. By washing the polyvinyl alcohol-based film with water, the surface of the polyvinyl alcohol-based film can be cleaned and the anti-caking agent can be washed, and the polyvinyl alcohol-based film can be swollen to prevent stain spots and the like. The effect of unevenness. The extension system can be carried out after dyeing with iodine, or can be performed while performing dyeing, and can be dyed with iodine while performing stretching. The extension can be carried out even in an aqueous solution such as boric acid, potassium iodide or the like, or in a water bath.

The light-transmitting protective film provided on one side of the polarizing element is preferably superior in transparency, mechanical strength, thermal stability, moisture shielding property, and isotropic property. The material of the light-transmitting protective film may, for example, be a polyester-based polymer such as polyethylene terephthalate or polyethylene naphthalate; or cellulose-based polymerization such as cellulose diacetate or cellulose triacetate. An acrylic polymer such as polymethyl methacrylate; a styrene polymer such as polystyrene or acrylonitrile styrene copolymer (AS resin); or a polycarbonate polymer. Further, examples of the polymer forming the light-transmitting protective film include polyolefin-based polymers such as polyethylene, polypropylene, and ethylene-propylene copolymer; cycloolefin polymers; vinyl chloride polymers; and nylon. A guanamine-based polymer such as an aromatic polyamine; a ruthenium-based polymer, a fluorene-based polymer, a polyether fluorene-based polymer, a polyetheretherketone-based polymer, a polyphenylene-sulfur-based polymer, or a vinyl alcohol-based polymerization A vinylidene chloride polymer, an ethylene butyral polymer, an aromatic ester polymer, a polyoxymethylene polymer, an epoxy polymer, or a blend of the above polymers. Further, for example, a thermosetting type or an ultraviolet curing type resin such as an acrylic type, an urethane type, an urethane type urethane type, an epoxy type or a polyoxymethylene type, etc. . The thickness of the light-transmitting protective film is generally set to 100 μm or less, preferably 1 to 80 μm. It is preferably 5~50μm.

The light-transmitting protective film is preferably a cellulose-based polymer such as cellulose triacetate or a cycloolefin-based polymer from the viewpoints of polarization characteristics, durability, and the like.

The polarizing element and the light-transmitting protective film are usually adhered to each other via an adhesive, an adhesive, or the like.

Examples of the adhesive and the adhesive agent include polyvinyl alcohol type, gelatin type, ethylene type latex type, aqueous polyurethane, and aqueous polyester.

The above-mentioned light-transmitting protective film may be a hard coat layer or a substance treated for the purpose of anti-reflection treatment, anti-sticking, diffusion or anti-glare.

The hard coat treatment is carried out for the purpose of preventing scratches on the surface of the polarizing plate, and for example, a hardened film which is excellent in hardness and smoothness by a suitable ultraviolet curable resin such as acrylic or polyoxygen is added to the protective film. A film surface or the like can be formed. The antireflection treatment is carried out for the purpose of external light antireflection on the surface of the polarizing plate, and can be achieved by forming a conventional antireflection film or the like. Further, the anti-adhesive treatment is carried out for the purpose of preventing adhesion to an adjacent layer.

Further, the anti-glare treatment is performed by preventing the external light from being reflected on the surface of the polarizing plate and preventing the polarizing plate from penetrating the light, for example, by sanding or embossing, or by blending into a transparent method. An appropriate method such as a method of applying fine particles can be formed by imparting a fine concavo-convex structure to the surface of the protective film. The fine particles contained in the formation of the fine uneven structure on the surface may be made of, for example, ceria, alumina, titania, zirconia, tin oxide, indium oxide, cadmium oxide, or cerium oxide having an average particle diameter of 0.5 to 50 μm. Inorganic fine particles having conductivity and conductivity, or transparent fine particles such as organic fine particles composed of a crosslinked or uncrosslinked polymer. In the case where the surface fine uneven structure is formed, the amount of the fine particles used is generally from 2 to 50 parts by weight, preferably from 5 to 25 parts by weight, per 100 parts by weight of the transparent resin forming the surface fine uneven structure. The anti-glare layer may also have a diffusion layer (a viewing angle expansion function or the like) for diffusing the polarizing plate through the light to expand the viewing angle or the like.

Further, the anti-reflection layer, the anti-adhesion layer, the diffusion layer, the anti-glare layer, and the like may be provided on the protective film, and may be provided in addition to the light-transmitting protective film and additionally provided in the form of an optical layer.

Next, a retardation film having a phase difference function will be described.

The retardation film may have a desired phase difference function, for example, a uniaxially stretched or biaxially stretched polymer film, or an alignment processor in the thickness direction (Z axis), or a liquid crystal The material is applied to a coating/alignment alignment film or the like.

A retardation film having a phase difference function preferably satisfies the following formulas [3] and [4]:

[3]20nm≦Re2≦200nm

[4]0nm≦Rth2≦30nm

Here, Re2 means a retardation value in the plane of the retardation film; and Rth2 means a retardation value in the thickness direction of the retardation film. Re2 and Rth2 are respectively Re2=(Nx2-Ny2)×d2[nm], and Rth2=(Nx2-Nz2)×d2[nm]. Further, d2 means the thickness of the retardation film, Nx2 and Ny2 means the main refractive index in the plane of the retardation film, and Nz2 means the main refractive index in the thickness direction, and Nx2>Ny2≧Nz2.

Since the Re2 value and the Rth2 value of the retardation film optical parameter depend on the mode of the liquid crystal display device and various optical parameters, it cannot be said in general, and the in-plane retardation value (Re2) is usually controlled in relation to the 550 nm monochromatic light. 20nm~200nm, preferably 30nm~180nm, especially in the range of 50nm~160nm, and the retardation value (Rth2) in the thickness direction is usually controlled from 0nm to 30nm, preferably 0nm~25nm, especially 0nm~15nm. .

By setting the Re2 value and the Rth2 value within the above range, the viewing angle improving film of the liquid crystal display device can expand the viewing angle while performing tone correction of the liquid crystal display. When the Re2 value is less than 20 nm or more than 200 nm, there is a possibility that the front surface characteristics of the liquid crystal display element are deteriorated due to the influence of the in-plane retardation value. Further, when the Rth2 value is less than 0 nm or more than 30 nm, there is a possibility that a sufficient viewing angle improvement effect or a case where unnecessary coloring occurs in oblique viewing may not be obtained.

The retardation film is preferably a method of performing uniaxial or biaxial stretching treatment of a film composed of a suitable polymer, or a film of a long film according to a heat shrinkable film as disclosed in Japanese Laid-Open Patent Publication No. Hei 5-157911. A birefringent film is obtained by heat-shrinking in the width direction and exhibiting a large phase difference in the thickness direction, and the material is, for example, a film or sheet made of an organic polymer material. For example, polyesters such as polyvinyl alcohol, polyimide, polyoxyxylene, polyfluorene, polyether ketone, polyetheretherketone, polyethylene terephthalate, polyethylene naphthalate, and the like A film composed of a polymer such as cellulose diacetate; a cellulose polymer such as cellulose triacetate; a transparent polymer such as a polycarbonate polymer or an acrylic polymer such as polymethyl methacrylate. Further, examples thereof include styrene polymers such as polystyrene and acrylonitrile styrene copolymer; olefin polymers such as polyethylene, polypropylene, polycycloolefin, and ethylene propylene copolymer; and vinyl chloride. A film composed of a transparent polymer such as a nylon, an aromatic polyamide or the like. Further, examples thereof include a vinylidene chloride-based polymer, an ethylene butyral-based polymer, an aromatic ester-based polymer, a polyoxymethylene-based polymer, an epoxy-based polymer, a blend of the above polymers, and the like. A film made of a transparent polymer or the like. Among these, optical films will be recommended to use plastic films such as cellulose triacetate, polycarbonate, and polycycloolefin. For the film of the organic polymer material, for example, ZEONOR (trade name, manufactured by Japan ZEON Co., Ltd.), ZEONEX (trade name, manufactured by Japan ZEON Co., Ltd.), Arton (trade name, manufactured by JSR Co., Ltd.), and the like are used. By having a drop A plastic film composed of a polymer material of an olefin structure is preferred.

The film thickness of the retardation film obtained by stretching or the like depends on Re2 and Rth2 as described above, but is usually set to 5 μm to 100 μm, preferably 10 μm to 80 μm.

The alignment film composed of a liquid crystal material such as a liquid crystal polymer may, for example, be a liquid crystalline polymer which exhibits a nematic alignment property which is uniform and a single region, and which can be easily fixed in an alignment state, on a substrate or via Applying a heat treatment on the substrate on which the alignment film is applied to form a uniform, single-region nematic structure, and then performing cooling to form an alignment film obtained by immobilization without damaging the alignment of the liquid crystal state; or The photopolymerizable liquid crystal compound is blended into a polymer to form a liquid crystal composition, and an alignment film which is subjected to polymerization is applied to a substrate or a substrate on which an alignment film is applied.

Next, an optical film which can laminate the elliptically polarizing plate of the present invention will be described.

The optical film may be a positive uniaxial optical anisotropic layer, a negative uniaxial optical anisotropic layer, or a biaxial optical anisotropic layer.

When the in-plane direction is the x direction and the y direction, and the thickness direction is the z direction, the positive uniaxial optical anisotropic element has a refractive index of nx>ny=nz. Further, the positive biaxial optical anisotropic element has a refractive index having a relationship of nx>nz>ny. The negative uniaxial optical anisotropic element has a refractive index of nx=ny>nz. The negative biaxial optical anisotropic element has a relationship of nx>ny>nz.

When the biaxial system is defined by the NZ coefficient = (nx-nz) / (nx-ny), it can be classified into: NZ>1 system negative biaxial, NZ=1 system positive uniaxial, NZ<1 system positive double axis.

Since the positive uniaxial optical anisotropic layer has a retardation film having the above-described phase difference function, the retardation value can be appropriately selected within the following range.

The retardation Re in the plane of the film is 20 nm to 500 nm, preferably 50 nm to 300 nm. If it is outside this range, the effect of improving the viewing angle when applied to a liquid crystal display device is lacking, and thus it is preferable to avoid it. Further, Re is a formula defined in a retardation film having a phase difference function as described above.

The optical film having a negative uniaxial optical anisotropic layer is not particularly limited since the non-liquid crystal material is excellent in heat resistance, chemical resistance, transparency, and also rigid, and thus is preferably, for example, cellulose three. Acrylate, ZEONEX, ZEONOR (all manufactured by Japan ZEON Co., Ltd.), polyolefins such as Arton (made by JSR); polyamine, polyimine, polyester, polyether ketone, poly aromatic A polymer such as an ether ketone, a polyamidoximine or a polyester quinone. These polymers may be used singly or in the form of a mixture of two or more kinds of functional groups such as a mixture of a poly(aryl ether ketone) and a polyamidamine. Among such polymers, polyiminoimide is preferred from the viewpoint of high transparency and high alignment. The polyimine is preferably, for example, a polyimine which has high in-plane orientation and is soluble in an organic solvent. For example, a condensation polymerization product of 9,9-bis(aminoaryl)fluorene and an aromatic tetracarboxylic dianhydride disclosed in Japanese Patent Laid-Open Publication No. 2000-511296, specifically, may contain one or more of the following formula (7). ) The repeating unit of the polymer shown.

[Chemical 6]

In the above formula (7), R ³ to R ^{6 are each a} hydrogen group, a halogen group, a phenyl group, a phenyl group substituted by 1 to 4 halogen atoms or a C _{1 10} alkyl group, and a C _{1 10} alkyl group. At least one substituent independently selected in the group. Preferably, R ³ to R ⁶ are independently independently selected from the group consisting of a halogen, a phenyl group, a phenyl group substituted with 1 to 4 halogen atoms or a C _{1 10} alkyl group, and a C _{1 10} alkyl group. A substituent.

In the above formula (7), a Z-based tetravalent aromatic group such as C ₆ to ₂₀ is preferably a pyromellicyl group, a polycyclic aromatic group or a polycyclic aromatic group derivative or a derivative according to the following formula ( 8) The base shown:

[Chemistry 7]

In the above formula (8), Z' is, for example, a covalent bond, a C(R ⁷ ) ₂ group, a CO group, an O atom, an S atom, a SO ₂ group, a Si(C ₂ H ₅ ) ₂ group or an NR ⁸ group. In the case of plurals, they may be the same or different. Further, w means an integer of 1 to 10. Means R ⁷ are each independently hydrogen or C (R ⁹⁾ _3. R ⁸ means hydrogen, an alkyl group having 1 to 20 carbon atoms, or a C ₆ to ₂₀ aromatic group, and when plural, they may be the same or different from each other. R ⁹ means independently hydrogen, fluorine or chlorine.

Further, the liquid crystal material may, for example, be a cholesteric alignment film composed of a liquid crystal material such as a cholesteric liquid crystalline polymer; a cholesteric alignment layer supported by a film; and a disk-shaped liquid crystal layer. First, it is preferable that the cholesteric alignment film is appropriately selected such as a heat treatment to have a uniform planar alignment of the cholesteric helical axis in the normal direction of the film, and the selective reflection wavelength λs is preferably 300 nm or less.

Further, the material for realizing the cholesteric alignment is not limited to the liquid crystalline polymer, and liquid crystal monomer molecules having a polymerizable group capable of achieving a cholesteric alignment depending on a monomer or liquid crystal having a polymerizable group can be used. a mixture of a monomer and a palm compound, and the like. It is also possible to carry out the cholesteric alignment by a suitable method such as heat treatment, and then harden the polymerizable group by an appropriate means such as heat or light to immobilize the cholesteric type.

Further, in addition to the liquid crystal material other than the above, which forms a negative uniaxial optical anisotropic layer, a horizontally aligned polymerizable discotic liquid crystal compound can be used.

When the thickness of the optical film having the negative uniaxial optical anisotropic layer is d3, the main refractive index in the optical anisotropic layer is Nx3 and Ny3, and the main refractive index in the thickness direction is Nz3. When Nx3≧Ny3>Nz3, the in-plane retardation value (Re3=(Nx3-Ny3)×d3[nm]) is preferably 0 nm to 20 nm, and the retardation value in the thickness direction (Rth3=(Nx3-Nz3)×d3) [nm]) is preferably 50 nm to 500 nm.

Since the optical parameter Re3 value and Rth3 value of the negative uniaxial optical anisotropic optical film depend on the mode of the liquid crystal display device and various optical parameters, it cannot be said in general, and the in-plane retardation with respect to the 550 nm monochromatic light. The value (Re3) is usually controlled at 0 nm to 20 nm, preferably 0 nm to 10 nm, preferably in the range of 0 nm to 5 nm, and the retardation value (Rth3) in the thickness direction is usually controlled at 50 nm to 500 nm, preferably 80 nm to 400 nm. Especially in the range of 100 nm to 300 nm.

By setting the Re3 value and the Rth3 value within the above range, the viewing angle improving film of the liquid crystal display device can expand the viewing angle while performing tone correction of the liquid crystal display. When the Re3 value is larger than 20 nm, there is a possibility that the front characteristics of the liquid crystal display element are deteriorated due to the influence of a large front surface difference value. Further, when the Rth3 value is less than 50 nm or more than 500 nm, there is a fear that a sufficient viewing angle improvement effect or a possibility of unnecessary coloring in oblique viewing may not be obtained.

Next, a method of manufacturing the elliptically polarizing plate of the present invention will be described.

The elliptically polarizing plate of the present invention comprises a linear polarizing plate having a laminated structure in which only one surface of the polarizing element is protected by a translucent protective film, a retardation film having a phase difference function, and a vertical alignment liquid crystal layer, and further, if necessary The optical film is assembled and bonded to each other by an adhesive layer or an adhesive layer (referred to as a "adhesive/adhesive layer"). Further, the vertical alignment liquid crystal layer formed on the alignment substrate may be applied to the linear polarizing plate, the retardation film, or the optical film by the adhesive/adhesive layer, and then the alignment substrate may be peeled off. The laminate is applied only by a method in which the vertical alignment liquid crystal layer is transferred onto a linear polarizing plate, a retardation film, or an optical film.

The specific manufacturing method is exemplified by the following methods [1] to [4]: In the following description, "/" refers to the interface of the layer.

[1] A method of manufacturing an elliptically polarizing plate, characterized by at least the following steps:

(1) The light-transmitting protective film is bonded to the polarizing element via the adhesive layer 1, and the first layer (I) (linear polarizing plate) composed of the light-transmitting protective film/adhesive layer 1/polarizing element is obtained. step;

(2) forming a layer of a liquid crystal composition exhibiting positive uniaxiality on the retardation film, and performing vertical alignment of the layer, and then forming a vertical alignment liquid crystal layer to which the alignment is fixed, thereby obtaining a retardation film/vertical a second step of aligning the liquid crystal layer to form the layered body (II);

(3) The retardation film side of the laminate (II) is bonded to the polarizing element side of the laminate (I) via the adhesive layer 2, whereby a light-transmitting protective film/adhesive layer 1/1 is obtained. The polarizing element/adhesive layer 2/phase difference film/vertical alignment liquid crystal layer constitutes the third step of the elliptically polarizing plate.

[2] A method of manufacturing an elliptically polarizing plate, characterized by at least the following steps:

(1) The light-transmitting protective film is bonded to the polarizing element via the adhesive layer 1, and the first layer (I) (linear polarizing plate) composed of the light-transmitting protective film/adhesive layer 1/polarizing element is obtained. step;

(2) forming a layer of a liquid crystal composition exhibiting positive uniaxiality on the retardation film, and performing vertical alignment of the layer, and then forming a vertical alignment liquid crystal layer to which the alignment is fixed, thereby obtaining a retardation film/vertical a second step of aligning the liquid crystal layer to form the layered body (II);

(3) The vertical alignment of the layered product (II) to the liquid crystal phase side is bonded to the polarizing element side of the layered product (I) via the adhesive layer 2, whereby the light-transmitting protective film/adhesive layer 1 is obtained. / Polarizing element / adhesive layer 2 / vertical alignment liquid crystal layer / retardation film constitutes the third step of the elliptically polarizing plate.

[3] A method of manufacturing an elliptically polarizing plate, characterized by at least the following steps:

(1) The light-transmitting protective film is bonded to the polarizing element via the adhesive layer 1, and the laminated body (I) (linear polarizing plate) comprising the light-transmitting protective film/adhesive layer 1/polarizing element is obtained. 1 step;

(2) forming a layer of a liquid crystal composition exhibiting a positive uniaxiality on the alignment substrate, and then vertically aligning the layer, and then forming a vertical alignment liquid crystal layer to which the alignment is fixed, thereby obtaining an alignment substrate/vertical alignment liquid crystal The second step of forming the layered body (III);

(3) The vertical alignment of the layered product (III) on the liquid crystal layer side is bonded to the retardation film via the adhesive layer 2, and then the alignment substrate is peeled off, and the vertical alignment liquid crystal layer is transferred onto the retardation film. The third step of forming the laminate (IV) from the retardation film/adhesive layer 2/vertical alignment liquid crystal layer;

(4) The retardation film side of the layered product (IV) is bonded to the polarizing element side of the layered product (I) via the adhesive layer 3 to obtain a light-transmitting protective film/adhesive layer 1/ The polarizing element/adhesive layer 3/retardation film/adhesive layer 2/vertical alignment liquid crystal layer constitutes the fourth step of the elliptically polarizing plate.

[4] A method of manufacturing an elliptically polarizing plate, characterized by at least the following steps:

(1) The light-transmitting protective film is bonded to the polarizing element via the adhesive layer 1, and the first layer (I) (linear polarizing plate) composed of the light-transmitting protective film/adhesive layer 1/polarizing element is obtained. step;

(2) forming a layer of a liquid crystal composition exhibiting a positive uniaxiality on the alignment substrate, and then vertically aligning the layer, and then forming a vertical alignment liquid crystal layer to which the alignment is fixed, thereby obtaining an alignment substrate/vertical alignment liquid crystal The second step of forming the layered body (III);

(3) The vertical alignment of the layered product (III) on the liquid crystal layer side is bonded to the retardation film via the adhesive layer 2, and then the alignment substrate is peeled off, and the vertical alignment liquid crystal layer is transferred onto the retardation film. The third step of forming the laminate (IV) from the retardation film/adhesive layer 2/vertical alignment liquid crystal layer;

(4) The vertical alignment of the layered product (IV) on the side of the liquid crystal layer is bonded to the polarizing element side of the layered product (I) via the adhesive layer 3, whereby the light-transmitting protective film/adhesive layer 1 is obtained. / Polarizing element / adhesive layer 3 / vertical alignment liquid crystal layer / adhesive layer 2 / retardation film constitutes the fourth step of the elliptically polarizing plate.

Further, in the method of laminating a linear polarizing plate, a retardation film, or an optical film, it is preferable to use, for example, a method of directly laminating the two using an adhesive/adhesive layer described later; And a liquid crystal polymer having a single-region liquid crystal alignment property, which can be easily applied by applying a liquid crystal polymer or the like which is fixed in an alignment state, and a liquid crystal polymer provided on the film substrate or containing the same The composition is transferred to another linear polarizing plate or film using an adhesive or an adhesive described later.

An adhesive or an adhesive which is formed on a linear polarizing plate, a vertically aligned liquid crystal layer, or an optical anisotropic layer, or an adhesive/adhesive layer used for transfer, before the optical isotropic and transparent There are no special restrictions on the rest. For example, a polymer such as an acrylic polymer, a polyoxymethylene polymer, a polyester, a polyurethane, a polyamide, a polyether, a fluorine, or a rubber may be appropriately selected and used as a base polymer. In the adhesion/adhesive agent, various additives such as a surfactant, an antifoaming agent, a tackifier, an adhesion imparting agent, and a leveling agent may be added in order to adjust coatability, adhesion, peelability, and the like. . Further, a reactive substance which is reacted or polymerized by external stimulation such as light, electron beam or heat; or a fluorine-based or rubber-based one may be used. Among these, in particular, it is preferable to use an adhesive such as an acrylic adhesive which is excellent in optical transparency, exhibits appropriate wettability, cohesiveness, and adhesive properties, and is excellent in weather resistance and heat resistance.

The linear polarizing plate used in the present invention is provided with a light-transmitting protective film on one side, and generally, since the linear polarizing plate is assembled in a liquid crystal display device, and the light-transmitting protective film layer is the outermost layer, the light-transmitting protection is provided. The film is capable of achieving protection of the polarizing element, and as described above, it is preferable to use transparency, mechanical strength, thermal stability, moisture shielding property, isotropic property, and the like. On the other hand, the polarizing element side where the light-transmitting protective film is not provided, or the vertical alignment liquid crystal layer or the retardation film does not belong to the outermost layer, but the adhesive/adhesive agent can also be prevented (protected) from occurring during various processes. The scratching condition, or the function of relieving the stress derived from the deformation caused by the processing/heat. In addition, the adhesive/adhesive layer is not necessary for each layer, and may be laminated in multiple layers.

The formation of the adhesive/adhesive layer can be carried out in a suitable manner. This example is, for example, prepared by dissolving or dispersing a binder/adhesive of about 10 to 40% by mass of the base polymer or a composition thereof in a solvent composed of a single substance or a mixture of a suitable solvent such as toluene or ethyl acetate. a solution, which is directly attached to the linear polarizing plate, the retardation film, the liquid crystal layer, or the optical anisotropic layer in a suitable expansion manner such as a coating method or a coating method; or is separated according to the above A bonding/adhesive layer is formed on the device, and then transferred to the linear polarizing plate, the retardation film, the liquid crystal layer, and the optical anisotropic layer. Further, a resin such as a natural product or a composition may be contained in the adhesive/adhesive layer, and in particular, a filler composed of, for example, an adhesive-imparting resin, glass fiber, glass beads, metal powder, or other inorganic powder may be used. , pigments, colorants, antioxidants, etc., additives added to the adhesive/adhesive. Further, it may be a layer of a binder/adhesive agent which is light-diffusing due to the inclusion of fine particles.

The thickness of the adhesive/adhesive layer is removed before the attached member can be adhered and sufficient adhesion can be maintained, and there is no particular limitation on the film thickness, depending on the characteristics of the adhesive/adhesive agent, and the adhesion/adhesion/ The following components are appropriately selected. Since it is strongly required to reduce the total thickness of the elliptically polarizing plate, the thickness of the adhesive/adhesive agent is as thin as possible, and is usually 2 to 80 μm, preferably 5 to 50 μm, particularly preferably 5 to 40 μm. If it is outside this range, it is preferable to avoid the occurrence of insufficient adhesion, delamination from the end when laminating or storage of the elliptically polarizing plate.

Further, when the vertical alignment liquid crystal layer is transferred onto the linear polarizing plate, the retardation film or the optical film via the adhesive/adhesive layer, in order to facilitate the transfer energy, the following can be suitably used (1) )~(7) Process:

(1) a vertical alignment liquid crystal layer formed on the alignment substrate and fixed by the liquid crystal alignment, directly attached to the linear polarizing plate, the retardation film or the optical film via the adhesive layer 1, and then the alignment substrate is peeled off. The vertical alignment liquid crystal layer is transferred onto a linear polarizing plate, a retardation film or an optical film.

(2) The vertical alignment liquid crystal layer formed on the alignment substrate and fixed by the liquid crystal alignment is bonded to the re-peelable substrate 1 via the adhesive layer 1, and then the alignment substrate is peeled off to vertically align the liquid crystal layer. After being transferred onto the re-peelable substrate 1, an intermediate 1 composed of a re-peelable substrate 1 / an adhesive layer 1 / a vertical alignment liquid crystal layer is obtained, and then bonded to the re-peelable substrate 2 via the adhesive layer 2 Thereafter, the releasable substrate 1 is peeled off to obtain an intermediate 2 composed of an adhesive layer 1/vertical alignment liquid crystal layer/adhesive layer 2/removable substrate 2, and then adhered to the adhesive layer 1 side. After the carrier-free paste of the film is formed, the release film is peeled off and attached to an appropriate linear polarizing plate, retardation film or optical film to peel off the re-peelable substrate 2.

(3) The vertical alignment liquid crystal layer formed on the alignment substrate and fixed by the liquid crystal alignment is bonded to the re-peelable substrate 1 via the adhesive layer 1, and then the alignment substrate is peeled off to transfer the vertical alignment liquid crystal layer On the re-peelable substrate 1, an intermediate 1 composed of a re-peelable substrate 1 / an adhesive layer 1 / a vertical alignment liquid crystal layer is obtained, and after bonding to the re-peelable substrate 2 via the adhesive layer 2, The re-peelable substrate 1 is peeled off to obtain an intermediate 2 composed of an adhesive layer 1 / a vertical alignment liquid crystal layer / an adhesive layer 2 / a re-peelable substrate 2, and is further adhered to the adhesive layer 1 side. After the carrier-free paste (adhesive) of the film, the releasable substrate 2 is peeled off, and the intermediate layer composed of the release film/adhesive layer/adhesive layer 1/vertical alignment liquid crystal layer/adhesive layer 2 is obtained. On the side of the adhesive layer 2, the unsupported dielectric paste without the release film is also adhered, and the release film/adhesive layer/adhesive layer 1/vertical alignment liquid crystal layer/adhesive layer 2 is obtained. /Adhesive layer / intermediate film composed of a release film, the release film is peeled off, and then attached to a linear polarizing plate, a retardation film or optical Film.

Furthermore, by adding an additive such as a surface modifier to the adhesive, the adhesion between the re-peelable substrate and the vertical alignment liquid crystal layer can be reduced, and the adhesion can be maintained. By the adhesive force between the peelable substrate and the adhesive layer, peeling can be performed in the case where the adhesive layer is adhered to the side of the re-peelable substrate. The effect of the surface modifier used at this time (for example, a surfactant, etc.) does not adversely affect the optical defect inspection property or peelability of the product, and there is no particular limitation on the type and amount of addition. . When the vertical alignment liquid crystal layer is transferred onto the linear polarizing plate, the retardation film or the optical film in accordance with such a method, in order to facilitate the transfer, the following (4) to (7) can be suitably used. Process.

(4) The vertical alignment liquid crystal layer formed on the alignment substrate and fixed by the liquid crystal alignment is bonded to the re-peelable substrate 1 via the adhesive layer 1, and then the alignment substrate is peeled off, and the vertical alignment liquid crystal layer is transferred. On the re-peelable substrate 1, an intermediate 1 composed of a re-peelable substrate 1 / an adhesive layer 1 / a vertical alignment liquid crystal layer is obtained, and after bonding to the re-peelable substrate 2 via the adhesive layer 2 The peelable substrate 1 is peeled off, and the intermediate 2 composed of the adhesive layer 1/vertical alignment liquid crystal layer/adhesive layer 2/releasable substrate 2 is obtained, and the adhesive layer 1 is adhered to the adhesive layer 1 side. After the carrier film is free of the carrier paste, the release film is peeled off and attached to a suitable linear polarizing plate, retardation film or optical film, and the re-peelable substrate is attached with the adhesive layer 2 attached thereto. 2 peeling.

(5) The vertical alignment liquid crystal layer formed on the alignment substrate and fixed by the liquid crystal alignment is bonded to the re-peelable substrate 1 via the adhesive layer 1, and then the alignment substrate is peeled off, and the vertical alignment liquid crystal layer is transferred. On the re-peelable substrate 1, an intermediate 1 composed of a re-peelable substrate 1 / an adhesive layer 1 / a vertical alignment liquid crystal layer is obtained, and after bonding to the re-peelable substrate 2 via the adhesive layer 2, The re-peelable substrate 1 is peeled off to obtain an intermediate 2 composed of an adhesive layer 1 / a vertical alignment liquid crystal layer / an adhesive layer 2 / a re-peelable substrate 2, and is further adhered to the adhesive layer 1 side. After the carrier-free paste of the film is formed, the re-peelable substrate 2 is peeled off with the adhesive layer 2 attached thereto, thereby producing a film of the release film/adhesive layer/adhesive layer 1/vertical alignment liquid crystal layer. The intermediate 5, which is also adhered to the side of the vertical alignment liquid crystal layer and adhered to the unsupported film without the release film, is obtained by the release film/adhesive layer/adhesive layer 1/vertical alignment liquid crystal layer/adhesive agent. Intermediate 2 composed of layer 2/adhesive layer/release film, peeling off the release film and attaching it to the appropriate linear deviation On a light plate, retardation film or optical film.

(6) The vertical alignment liquid crystal layer formed on the alignment substrate and fixed by the liquid crystal alignment is bonded to the re-peelable substrate 1 via the adhesive layer 1, and then the alignment substrate is peeled off, and the vertical alignment liquid crystal layer is transferred. On the re-peelable substrate 1, an intermediate 1 composed of a re-peelable substrate 1 / an adhesive layer 1 / a vertical alignment liquid crystal layer is obtained, and after bonding to the re-peelable substrate 2 via the adhesive layer 2 The peelable substrate 2 is peeled off, and the intermediate 2 composed of the re-peelable substrate 1 / the adhesive layer 1 / the vertical alignment liquid crystal layer / the adhesive layer 2 is obtained, and the adhesive layer 2 is adhered to the adhesive layer 2 side. After the carrier film is free of the carrier paste, the release film is peeled off, and then attached to a suitable linear polarizing plate, retardation film or optical film, and the re-peelable substrate is attached with the adhesive layer 1 attached thereto. 1 peeling.

(7) The vertical alignment liquid crystal layer formed on the alignment substrate and fixed by the liquid crystal alignment is bonded to the re-peelable substrate 1 via the adhesive layer 1, and then the alignment substrate is peeled off, and the vertical alignment liquid crystal layer is transferred. On the re-peelable substrate 1, an intermediate 1 composed of a re-peelable substrate 1 / an adhesive layer 1 / a vertical alignment liquid crystal layer is obtained, and after bonding to the re-peelable substrate 2 via the adhesive layer 2 The peelable substrate 2 is peeled off, and the intermediate 2 composed of the re-peelable substrate 1 / the adhesive layer 1 / the vertical alignment liquid crystal layer / the adhesive layer 2 is obtained, and the adhesive layer 2 is adhered to the adhesive layer 2 side. After the carrier film of the release film is removed, the re-peelable substrate 1 is peeled off in the state in which the adhesive layer 1 is adhered, and the vertical alignment liquid crystal layer/adhesive layer 2/adhesive layer/release film is formed. The intermediate 7 is also adhered to the side of the vertical alignment liquid crystal layer, and the non-carrier paste without the release film is adhered to obtain the release film/adhesive layer/vertical alignment liquid crystal layer/adhesive layer 2/adhesive agent. Intermediate 8 composed of a layer/release film, peeling off the release film and attaching it to a suitable linear polarizing plate, phase Difference film or the optical film.

Further, when the vertical alignment liquid crystal layer is transferred onto the linear polarizing plate, the retardation film or the optical film via the adhesive/adhesive layer, not only the surface of the liquid crystal layer but also the other components are adhered to the surface of the liquid crystal layer. The surface is also surface treated to improve adhesion to the adhesive/adhesive layer. The means for the surface treatment is not particularly limited, and a surface treatment such as corona discharge treatment, sputtering treatment, low-pressure UV irradiation, or plasma treatment which can maintain the surface transparency of the liquid crystal layer can be suitably employed. Preferably, the surface treatment method is a corona discharge treatment.

As the re-peelable substrate, for example, an olefin-based resin such as polyethylene, polypropylene, or poly(4-methylpentene-1) resin; polyamine, polyimine, polyamidimide, or poly Ether quinone imine, polyether ketone, polyether ether ketone, polyether oxime, polyketone sulfide, polyfluorene, polystyrene, polyaryl sulfide, polydiphenyl ether, polyethylene terephthalate, Polybutylene terephthalate, polyarylate, polyacetal, uniaxially stretched polyester, polycarbonate, polyvinyl alcohol, polymethyl methacrylate, polyaryl ester, amorphous polyolefin, drop A film of an olefin resin, cellulose triacetate, or an epoxy resin.

In particular, a film having excellent optical defect inspection property, transparency, and optical isotropic property, for example, poly(4-methylpentene-1), polymethyl methacrylate, polystyrene, poly Carbonate, polyether oxime, polyaryl ester, amorphous polyolefin, drop Various films such as an olefin resin, cellulose triacetate, or epoxy resin.

In the plastic film, in order to maintain moderate removability, coating of polyfluorene or the like may be performed on the surface in advance, or an organic film or an inorganic film may be formed in advance. Further, for the same purpose, the surface of the plastic film may be subjected to a chemical treatment such as saponification treatment or a physical treatment such as corona treatment.

Further, in order to adjust the releasability of the re-peelable substrate, a slip agent or a surface modifier may be contained in the plastic film. The above-mentioned slip agent is not particularly limited in terms of the type and amount of addition, insofar as it does not adversely affect the inspectability and peelability of optical defects. Specific examples of the lubricant include, for example, fine cerium oxide and fine alumina. The amount of the additive is usually such that the haze value of the re-peelable substrate is usually 50% or less, preferably 30% or less. If the amount added is too small, the effect of addition cannot be exhibited. Conversely, when the amount is too large, the inspection property of the optical defect is deteriorated, and thus it is preferable to avoid it.

Further, various other well-known additives such as an anti-caking agent, an antioxidant, an antistatic agent, a heat stabilizer, an impact resistance improver, and the like may be contained as needed.

The peeling force of the related re-peelable substrate, even if the re-peelable substrate made of the same material differs depending on factors such as the production method, the surface state, and the wettability between the adhesive and the adhesive to be used, It is impossible to determine it, but the peeling force at the interface with the adhesive (180° peeling, peeling speed 30cm/min, measured at room temperature) is usually set to 0.38~12N/m, especially 0.38~8.0N. /m is better. When the peeling force is lower than this value, after the liquid crystal material layer on the alignment substrate is bonded to the re-peelable substrate, when the alignment substrate is peeled off, the peeling force is too low to appear on the re-peelable substrate, resulting in a desired A good peeling state cannot be obtained on the surface, resulting in insufficient transfer of the liquid crystal material layer to the re-peelable substrate. Conversely, when the peeling force is too high, when the re-peelable substrate is peeled off, the liquid crystal material layer is destroyed. Or it is not possible to peel off at the interface with the desired layer, so it is best to avoid it.

Further, the thickness of the re-peelable substrate may also affect the peelability, and is preferably 16 to 100 μm, particularly preferably 25 to 50 μm. If the thickness is too thick, the peeling point is unstable, and the peeling property may be deteriorated. On the other hand, if it is too thin, since the mechanical strength of the film cannot be maintained, there is a fear that a failure such as tearing may occur in the manufacturing. Sex.

Furthermore, the liquid crystal material may be spread on the linear polarizing plate, the retardation film or the optical film without passing through the adhesive/adhesive layer, and the liquid crystal material may be aligned, and then the liquid crystal material may be aligned. By using light irradiation and/or heat treatment, the alignment state is fixed and manufactured. If necessary, after the alignment film is provided on the linear polarizing plate, the retardation film or the optical film, the liquid crystal material may be developed, and the liquid crystal material may be aligned, and then irradiated with light and/or heat. This alignment state can be obtained by fixing it.

The elliptically polarizing plate of the present invention comprises an elliptically polarizing plate comprising a linear polarizing plate, a vertical alignment liquid crystal layer fixed in a vertical alignment, and a retardation film having a phase difference function, and an elliptical layer in which an optical film is laminated as needed. The polarizing plate may have, for example, the following configurations (1) to (6).

In the following description, "/" is the interface of the above-mentioned finger layer, and the adhesive/adhesive layer is omitted.

(1) Linear polarizing plate / retardation film with phase difference function / vertical alignment liquid crystal layer / positive uniaxial optical anisotropic layer having phase difference in film surface / negative single sheet having phase difference in film thickness direction Axial optical anisotropic layer

(2) Linear polarizing plate / phase difference film with phase difference function / vertical alignment liquid crystal layer / negative biaxial optical anisotropic layer

(3) Linear polarizing plate/phase difference film with phase difference function/vertical alignment liquid crystal layer/positive uniaxial optical anisotropic layer having phase difference in film surface

(4) Linear polarizing plate/vertical alignment liquid crystal layer/phase difference film having phase difference function/positive uniaxial optical anisotropic layer having phase difference in film surface/reduced sheet having phase difference in film thickness direction Axial optical anisotropic layer

(5) Linear polarizer/vertical alignment liquid crystal layer/phase difference film with phase difference function/negative biaxial optical anisotropic layer

(6) Linear polarizer/vertical alignment liquid crystal layer/phase difference film with phase difference function/positive uniaxial optical anisotropic layer with phase difference in film surface

When a liquid crystal display device in which the elliptically polarizing plate of the present invention is disposed is produced, members such as a light diffusion layer, a light control film, a light guide plate, and a cymbal sheet may be additionally provided as needed.

The liquid crystal display device using the elliptically polarizing plate of the present invention may have the following structures (7) to (14):

(7) Linear polarizing plate / retardation film having phase difference function / vertical alignment liquid crystal layer to which vertical alignment is fixed / positive uniaxial optical anisotropic layer having phase difference in film surface / in film thickness direction Negative uniaxial optical anisotropic layer/liquid crystal cell with phase difference / positive uniaxial optical anisotropic layer/polarizer/backlight with phase difference in film plane

(8) Linear polarizing plate/phase difference film having phase difference function/vertical alignment liquid crystal layer to which vertical alignment is fixed/positive uniaxial optical anisotropic layer having phase difference in film surface/in film thickness direction Negative uniaxial optical square layer/liquid crystal cell having phase difference / negative uniaxial optical anisotropic layer having phase difference in film thickness direction / positive uniaxial optical non-phase difference in film plane Isotropic layer / polarizer / backlight

(9) Linear polarizing plate / retardation film having phase difference function / vertical alignment liquid crystal layer to which vertical alignment is fixed / positive uniaxial optical anisotropic layer / liquid crystal cell having phase difference in film surface / Negative uniaxial optical anisotropic layer with phase difference in film thickness direction / positive uniaxial optical anisotropic layer/polarizer/backlight with phase difference in film surface

(10) Linear polarizing plate / retardation film with phase difference function / Vertical alignment liquid crystal layer / negative biaxial optical anisotropic layer / liquid crystal cell with vertical alignment fixed / positive phase difference in film surface Uniaxial optical anisotropic layer / polarizer / backlight

(11) Linear polarizing plate / retardation film with phase difference function / vertical alignment liquid crystal layer / negative biaxial optical anisotropic layer / liquid crystal cell / negative biaxial optical anisotropy Layer/polarizer/backlight

(12) Linear polarizing plate / retardation film with phase difference function / Vertical alignment liquid crystal layer for vertical alignment / Positive uniaxial optical anisotropic layer / liquid crystal cell / negative with phase difference in film surface Biaxial optical anisotropic layer / polarizer / backlight

(13) Linear polarizing plate / retardation film with phase difference function / vertical alignment liquid crystal layer / liquid crystal cell / polarizing plate / backlight which is fixed by vertical alignment

(14) Linear polarizing plate / Vertical alignment liquid crystal layer to which vertical alignment is fixed / Phase difference film / Liquid crystal cell / polarizing plate / backlight with phase difference function

Further, the positive uniaxial optical anisotropic layer optical anisotropic layer and the negative biaxial optical anisotropic layer described in the above (1) to (6), and (7) to (9) a liquid crystal cell, or a positive uniaxial optical anisotropic layer having a phase difference in a film plane adjacent to a negative uniaxial optical anisotropic layer, and a negative biaxial axis of (10) to (12) The optically anisotropic layer preferably exhibits a phase difference of 1/4 wavelength in the plane.

Preferably, the retardation value (Re) in each of the above optical anisotropy layers is 1/4 wavelength phase difference, and the relative wavelength 550 nm light is in the range of 100 nm to 180 nm, preferably 120 nm to 160 nm, particularly 130 nm to 150 nm. good. When it is outside the above range, sufficient circular polarization cannot be obtained when combined with a polarizing plate, and there is a possibility that display characteristics may be lowered when viewed from the front.

In addition, the thickness of the negative biaxial optical anisotropic layer of the above (2), (5), (10) to (12) is d4, and the principal refractive index in the plane is Nx4 or Ny4. When the refractive index in the thickness direction is Nz4 and Nx4>Ny4>Nz4, the retardation value in the thickness direction (Rth4=(Nx4-Nz4)×d4[nm]) must be set to compensate for the thickness of the vertical alignment type liquid crystal cell. The condition of the viewing angle compensation effect is exerted by the phase difference of the directions. Therefore, although the phase difference in the thickness direction of the vertical alignment type liquid crystal cell varies, it is preferably set in the range of 50 nm to 600 nm, preferably 100 nm to 400 nm, particularly preferably 200 nm to 300 nm. If it is outside the above range, a sufficient angle of view improvement effect cannot be obtained, or there is a possibility that unnecessary coloring may occur when viewed from an oblique direction.

The liquid crystal cell used in the present invention is not particularly limited, and examples thereof include a penetrating, reflective, and transflective liquid crystal cell. The liquid crystal cell is exemplified by a mode in which liquid crystal alignment is performed, and examples thereof include a TN type, an STN type, a VA (vertical alignment) type, and a MVA (multi-domain vertical alignment) type. OCB (optically compensated bend) type, ECB (electrically controlled biriefringence) type, HAN (hybrid-aligned nematic) type, IPS (in-plane switching) ), Bistable Nematic type, ASM (Axially Symmetric Aligned Microcell) type, halftone gray scale type, ferroelectric liquid crystal, display method using anti-strong dielectric liquid crystal, and the like.

The transparent substrate constituting the liquid crystal cell is removed from the material which constitutes the liquid crystal layer and exhibits liquid crystallinity, and is disposed before being aligned in a specific alignment direction, and is not particularly limited. Specifically, for example, a transparent substrate having a liquid crystal alignment property may be used as the substrate itself, or a substrate such as a transparent substrate having an alignment film or the like having a liquid crystal alignment property may be provided without the alignment ability of the substrate body. Further, the electrode system of the liquid crystal cell can use a known thing such as ITO. The electrode may be disposed on the surface of the transparent substrate adjacent to the liquid crystal layer, and may be disposed between the substrate and the alignment film when the substrate provided with the alignment film is used.

In the liquid crystal alignment, a single directionality in the unit plane can be used, and a liquid crystal display element which is divided by alignment can be used. In addition, a method of applying a voltage to the liquid crystal cell may be, for example, a passive type using an ITO electrode or the like, or an active type using a TFT (Thin Film Transistor) electrode, a TFD (Thin Film Diode) electrode, or the like. A liquid crystal display element is driven.

A liquid crystal display device in which a polarizing plate or an optical film is disposed on one side or both sides of a liquid crystal cell, or a suitable liquid crystal display device such as a backlight or a reflecting plate can be used. In this case, the optical film can be disposed on one side or both sides of the liquid crystal cell. When the polarizing plate or the optical film is provided on both sides, the lines may be the same or different. Further, when a liquid crystal display device is formed, suitable components such as a diffusion plate, an antiglare layer, an antireflection film, a protective plate, a ruthenium array, a lens array sheet, a light diffusion plate, and a backlight can be disposed at appropriate positions. 1 or more layers.

Further, by forming one of the substrates of the liquid crystal cell as a reflective functional region and a substrate having a penetrating functional region, a transflective liquid crystal display device can be formed.

The region having a reflection function (hereinafter referred to as "reflection layer") included in the transflective reflector used for the transflective liquid crystal display device is not particularly limited, and examples thereof include aluminum, silver, gold, and chromium. a metal such as platinum, or an alloy containing the same; an oxide such as magnesium oxide; a multilayer film of a dielectric material; a liquid crystal exhibiting selective reflection; or a combination thereof. The reflective layers can be planar and can also be curved. Further, the reflective layer may be a surface having a surface shape such as a concavo-convex shape and having a diffuse reflectance; or an electrode on the back side of the liquid crystal cell observer side; or a combination thereof.

In the liquid crystal display device of the present invention, in addition to the above-described constituent members, other constituent members may be attached. For example, by attaching a color filter to the liquid crystal display device of the present invention, a color liquid crystal display device capable of performing color or full color display with high color purity can be obtained.

[Examples]

The present invention will be specifically described below by way of examples, but the invention is not limited thereto.

In addition, each measurement method used in the examples is as follows:

(1) Determination of ¹ H-NMR

The compound was dissolved in dihydrochloroform and measured by ¹ H-NMR (INOVA-400, manufactured by Variant) of 400 MHz.

(2) Determination of GPC

The compound was dissolved in tetrahydrofuran, and TSK-GEL SuperH1000, SuperH2000, SuperH3000, and SuperH4000 were connected in series using an 8020 GPC system manufactured by Tosoh Corporation, and the eluate was measured using tetrahydrofuran. The correction of the molecular weight uses polystyrene standards.

(3) Microscope observation

The alignment state of the liquid crystal was observed using a BH2 polarizing microscope manufactured by Olympus Optics Co., Ltd.

(4) Determination of parameters of liquid crystal film

The automatic complex refractometer KOBRA21ADH manufactured by Oji Scientific Co., Ltd. was used.

(5) Determination of DSC (measurement of glass transfer point (Tg))

After the liquid crystal layer was taken, it was measured using a differential scanning calorimeter (DSC, DSC-7 manufactured by Perkin Elmer Co., Ltd.) at a temperature elevation rate of 20 ° C/min.

(6) Viewing angle measurement

The viewing angle measurement of the liquid crystal display device was carried out by using EzContrast manufactured by ELDIM Co., Ltd., and an iso-contrast curve was obtained.

<Reference Example 1> (production of laminate 1)

A cellulose triacetate (TAC) film (40 μm, manufactured by FUJIFILM Co., Ltd.) was immersed in a 2% by mass aqueous potassium hydroxide solution at room temperature for 5 minutes to carry out saponification treatment, and then washed in running water and then dried. A polarizing element is obtained by adsorbing iodine on the stretched polyvinyl alcohol, and a layered body 1 is obtained by laminating a saponified TAC film on one surface of the polarizing element using an adhesive layer 1 as an acrylic adhesive. (TAC film/adhesive layer 1/polarizing element).

(production of laminate 2)

The side chain type liquid crystalline polymer compound represented by the following formula (9) is synthesized by radical copolymerization. The molecular weight measured by GPC is, in terms of polystyrene, the number average molecular weight Mn = 8000 and the weight average molecular weight Mw = 15000. Further, the formula (9) is described based on the structure of the block polymer, and represents the structural ratio of the monomer.

[化8]

10.0 g of the side chain type liquid crystalline polymer compound represented by the formula (9) was dissolved in 90 ml of cyclohexanone, and a triallyl hexafluoroantimony salt 50% propylene carbonate solution (manufactured by Aldrich Co., Ltd.) was added in the dark. After 1.0 g of the reagent and the filter were filtered through a filter made of a polytetrafluoroethylene having a pore size of 0.45 μm, a solution of the liquid crystal composition was prepared.

The alignment substrate is prepared as follows. On a strip of polyethylene terephthalate (PET) film (manufactured by TORAY) with a width of 650 mm and a thickness of 38 μm, the slit coater continuously reforms the alkyl group of polyvinyl alcohol (PVA, KURARAY). A 5 mass% solution of a (method) system and MP-203) (a solvent mixture of solvent water and isopropyl alcohol according to a mass ratio of 1:1) was applied, dried, and then subjected to heat treatment at 130 ° C to obtain PVA. The alignment substrate film 1 having a layer thickness of 1.2 μm.

Next, the PVA layer was rubbed with a rubbing rubbing cloth. The peripheral speed ratio (friction cloth moving speed / substrate film moving speed) at the time of rubbing was set to 4.

On the alignment substrate obtained as described above, the solution of the liquid crystal composition obtained as described above was continuously applied by a slit coater, dried, and then subjected to heat treatment at 130 ° C for 10 minutes to form a liquid crystal. The composition layer is vertically aligned. Next, while adhering to a metal roll heated to 60 ° C, the liquid crystal composition was hardened by irradiating ultraviolet light (UV) (which is measured by 365 nm) at 600 mJ/cm ² from above with a high-pressure mercury lamp. Then, a laminate 2 (PET film/PVA layer/vertical alignment liquid crystal layer) was obtained.

(production of laminate 3)

The laminate 3 is produced for the measurement of the optical parameters of the vertically aligned liquid crystal layer obtained.

Since the PET film used for the alignment substrate has a large birefringence, it is difficult to measure the optical parameters (Re, Rth, etc.) of the vertically aligned liquid crystal layer in the form of the laminate 2, so that the cellulose triacetate (TAC) film is formed. The vertical alignment liquid crystal layer is transferred as follows.

In other words, on the optical element on the PET film, the ultraviolet curable adhesive was applied in a thickness of 5 μm, and laminated on a TAC film (thickness: 40 μm), and ultraviolet light was applied from the TAC film side. After the adhesive is cured, the PVA layer and the PET film are peeled off to obtain a laminate 3 (vertical alignment liquid crystal layer/adhesive layer 2/TAC film).

When the obtained laminated body 3 was observed under a polarizing microscope, it was found that the single region having no misdirection was uniformly aligned, and it was found from the observation of the conoscope that it was a vertical alignment having a positive uniaxial refractive index structure. The in-plane retardation value (Re) of the laminated body 3 measured by KOBRA21ADH was 0.5 nm, and the retardation value (Rth) in the thickness direction was -140 nm. Further, since the TAC film used in the single system has negative uniaxiality, and Re is -0.5 nm and Rth is +40 nm, it is estimated that Re is 0 nm and Rth is -100 nm in the vertical alignment liquid crystal layer alone.

Further, only the portion of the vertical alignment liquid crystal layer of the laminate 3 was taken, and the glass transition point was measured by DSC, and as a result, Tg was 100 °C. Further, the pencil hardness of the surface of the vertical alignment liquid crystal layer is about 2H, and a sufficiently strong film can be obtained.

<Reference Example 2> (production of film 1)

a retardation film having a phase difference in the plane ( WR, Teijin Co., Ltd., which performs longitudinal uniaxial stretching at 230 ° C, obtains a film 1 having negative biaxiality. The phase difference in the plane is 140 nm.

(production of ellipsoidal polarizer A)

The film 1 was subjected to corona discharge treatment (250 W ‧ min/m ² ), and a polarizing plate protected by a TAC film using an isotropic protective film was attached to both sides of the polarizing element via an adhesive to obtain elliptically polarized light. Plate A (film 1 / adhesive layer / TAC film / adhesive layer / polarizing element / adhesive layer / TAC film). The film thickness of the elliptically polarizing plate A was 190 μm.

<Example 1> (production of laminate 4)

A retardation film (ZEONOR film, manufactured by Nippon Zeon Co., Ltd.) having a phase difference of 140 nm in the in-plane direction and a phase difference of 0 nm in the film thickness direction was subjected to rubbing treatment using a rubbing cloth, and the liquid crystal composition obtained in Reference Example 1 was obtained. The solution was subjected to continuous coating using a slit coater, and after drying, it was subjected to heat treatment at 130 ° C for 10 minutes to vertically align the liquid crystal composition layer. Next, while adhering to a metal roll heated to 60° C., a high-pressure mercury lamp was used to irradiate 600 mJ/cm ^{2 of} ultraviolet light (UV) (the amount of light measured by 365 nm) from above, and the liquid crystal composition was cured. A laminate 4 (ZEONOR film/vertical alignment liquid crystal layer) is obtained.

(production of elliptically polarizing plate 1)

Purposes corona ZEONOR film 4 side of the laminate discharge treatment (250W‧min / m ^2), is attached via the adhesive paste laminate belonging linear polarizers 1, it is obtained an elliptically polarizing plate of the present invention (the TAC film / Next Agent layer 1 / polarizing element / adhesive layer / ZEONOR film / vertical alignment liquid crystal layer).

(production of elliptically polarizing plate 2)

The corona discharge treatment (250 W ‧ min/m ² ) was applied to the side of the vertical alignment liquid crystal layer of the laminated body 4, and the laminated body 1 belonging to the linear polarizing plate was attached via an adhesive to obtain the elliptically polarizing plate 2 of the present invention (TAC film). / adhesive layer 1 / polarizing element / adhesive layer / vertical alignment liquid crystal layer / ZEONOR film). The film thickness of the elliptically polarizing plate 2 was 126 μm.

<Example 2> (Production of laminated body 5)

Alkyl-modified polyvinyl alcohol (PVA, KURARAY Co., Ltd., MP-) was obtained on a retardation film (ZEONOR film, manufactured by ZEON Co., Ltd.) having a phase difference of 140 nm in the in-plane phase and a phase difference of 0 nm in the film thickness direction. a 5% by mass solution of 203) (a solvent mixture of solvent-based water and isopropyl alcohol in a mass ratio of 1:1), which was applied by a slit coater, dried, and then subjected to heat treatment at 130 ° C to obtain The alignment substrate film 2 having a PVA layer thickness of 1.2 μm.

On the alignment substrate film 2, the solution of the liquid crystal composition obtained in Reference Example 1 was subjected to continuous coating using a slit coater, dried, and then subjected to heat treatment at 130 ° C for 10 minutes. The liquid crystal composition layer is vertically aligned. Next, while adhering to a metal roll heated to 60 ° C, the liquid crystal composition was hardened by irradiating ultraviolet light (UV) (which is measured by 365 nm) at 600 mJ/cm ² from above with a high-pressure mercury lamp. Then, a laminate 5 (ZEONOR film/PVA layer/vertical alignment liquid crystal layer) is obtained.

(Production of elliptically polarizing plate 3)

The corona discharge treatment (250 W ‧ min/m ² ) was applied to the side of the vertical alignment liquid crystal layer of the laminated body 5, and the laminated body 1 belonging to the linear polarizing plate was attached via an adhesive to obtain the elliptically polarizing plate 3 of the present invention (TAC film). / adhesive layer 1 / polarizing element / adhesive layer / vertical alignment liquid crystal layer / PVA layer / ZEONOR film).

<Example 3> (production of laminate 6)

A commercially available UV-curable adhesive (UV-3400, manufactured by Toagosei Co., Ltd.) was used as the adhesive layer 3 on the vertical alignment liquid crystal layer of the laminate 2, and was applied in a 5 μm thick state, and then in-plane. A retardation film (ZEONOR film, manufactured by Nippon Zeon Co., Ltd.) having a phase difference of 140 nm and a phase difference of 0 nm in the film thickness direction is laminated, and ultraviolet rays are applied from the ZEONOR film side to cure the adhesive layer 3, and then adhered thereto. The PET film was peeled off in the state of the PVA layer to obtain a laminate 6 (ZEONOR film/adhesive layer 3/vertical alignment liquid crystal layer).

(Production of elliptically polarizing plate 4)

Purposes corona ZEONOR film side of the laminate 6 discharge treatment (250W‧min / m ^2), is attached via the adhesive paste laminate belonging linear polarizers 1, to obtain the elliptically polarizing plate of the present invention, it is 4 (TAC film / Next Agent layer 1 / polarizing element / adhesive layer / ZEONOR film / adhesive layer 3 / vertical alignment liquid crystal layer).

(Production of elliptically polarizing plate 5)

The corona discharge treatment (250 W ‧ min/m ² ) was applied to the side of the vertical alignment liquid crystal layer of the laminated body 6, and the laminated body 1 belonging to the linear polarizing plate was attached via an adhesive to obtain the elliptically polarizing plate 5 of the present invention (TAC film). / adhesive layer 1 / polarizing element / adhesive layer / vertical alignment liquid crystal layer / adhesive layer 3 / ZEONOR film).

<Example 4> (Production of elliptically polarizing plate 6)

1 for the purposes of the film to corona discharge treatment (250W‧min / m ^2), via an adhesive applicators relative vertical alignment of the elliptical polarizing plate to the liquid crystal layer 4 side, then obtain an elliptically polarizing plate 6 (TAC film / adhesive layer 1 / Polarizing element/adhesive layer/ZEONOR film/adhesive layer 3/vertical alignment liquid crystal layer/adhesive layer/film 1). The film thickness of the elliptically polarizing plate 6 was 172 μm.

<Example 5> (Production of IPS type liquid crystal display device)

For the commercially available IPS type liquid crystal televisions arranged in the order of the backlight, the backlight side polarizing plate, the IPS type liquid crystal unit, and the viewing side polarizing plate, as shown in FIG. 1, instead of the viewing side polarizing plate, the ellipse of the present invention is replaced. Polarizing plate 2. In this case, as compared with the case where the elliptically polarizing plate 2 is not used, it is known that the viewing angle is enlarged, and a good image can be obtained even from the oblique direction. In addition, the comparative perspective dependence is shown in Figure 2. In the figure, a thick black line refers to an area where the contrast is more than 100. In addition, concentric circles refer to a viewing angle of 20 degrees (the same applies hereinafter).

<Example 6> (Production of VA type liquid crystal display device)

For a commercially available VA type liquid crystal television arranged in the order of a backlight, a backlight side polarizing plate, an IPS type liquid crystal cell, and a viewing side polarizing plate, as shown in FIG. 3, instead of the viewing side polarizing plate, the ellipse of the present invention is replaced. The polarizing plate 6 was replaced with the elliptically polarizing plate A obtained in Reference Example 2 instead of the backlight side polarizing plate. In this case, as compared with the case where the elliptically polarizing plate 6 is not used, it is known that the angle of view is enlarged, and a good image can be obtained even from the oblique direction. The contrast dependence dependence is shown in Figure 4.

<Comparative Example 1> (production of laminate 8)

On the vertical alignment liquid crystal layer of the laminate 2, a commercially available UV-curable adhesive (UV-3400, manufactured by Toagosei Co., Ltd.) was used as the adhesive layer 4, and was applied in a thickness of 5 μm, and then a PET film was used. After laminating, the ultraviolet ray is irradiated from the PET film side, and after the adhesive layer 4 is cured, the PET film adjacent to the PVA layer is peeled off while the PVA layer is attached, and the laminated body 7 is obtained. Film/Binder Layer 4/Vertical Alignment Liquid Crystal Layer).

Further, on the side of the vertical alignment liquid crystal layer of the laminated body 7, a commercially available UV-curable adhesive (UV-3400, manufactured by Toagos Corporation) was used as the adhesive layer 5, and was applied in a state of 5 μm thick, and then The layered body 8 was obtained by laminating the TAC film and irradiating the TAC film side with ultraviolet rays, and then peeling the PET film, thereby obtaining the layered body 8 (the adhesive layer 4 / the vertical alignment liquid crystal layer / the adhesive layer 5) /TAC film).

(production of elliptically polarizing plate B)

Corona discharge treatment (250 W ‧ min/m ² ) was applied to the adhesive layer 4 side of the laminated body 8 , and the laminated body 1 belonging to the linear polarizing plate was attached via an adhesive, and then the TAC film was peeled off to obtain an elliptically polarizing plate. B (TAC film/adhesive layer 1/polarizing element/adhesive layer/adhesive layer 4/vertical alignment liquid crystal layer/adhesive layer 4).

(Production of IPS type liquid crystal display device)

For the commercially available IPS type liquid crystal televisions arranged in the order of the backlight, the backlight side polarizing plate, the IPS type liquid crystal unit, and the viewing side polarizing plate, as shown in FIG. 5, instead of the viewing side polarizing plate, the elliptical polarizing plate B is replaced. . In this case, the viewing angle becomes narrower than in the case of using the elliptically polarizing plate 2. The contrast dependence is shown in Figure 6.

<Comparative Example 2> (production of elliptically polarizing plate C)

Retardation, thickness direction retardation of 140nm in-plane retardation film 0nm (the ZEONOR film, by ZEON Japan (shares)) was performed to corona discharge treatment (250W‧min / m ^2), the adhesive paste is attached via linear polarization belongs The laminated body 1 of the board was obtained as an elliptically polarizing plate C (TAC film/adhesive layer 1 / polarizing element / adhesive layer / ZEONOR film).

(Production of IPS type liquid crystal display device)

In the production of the IPS type liquid crystal display device of Comparative Example 1, the same procedure was carried out except that the ellipsoidal polarizing plate B was replaced with the elliptically polarizing plate C. As in Comparative Example 1, the viewing angle was narrower than in the case of using the elliptically polarizing plate 2. The contrast dependence is shown in Figure 7.

<Comparative Example 3> (Production of IPS type liquid crystal display device)

For the commercially available IPS type liquid crystal televisions arranged in the order of the backlight, the backlight side polarizing plate, the IPS type liquid crystal unit, and the viewing side polarizing plate, as shown in FIG. 5, instead of the viewing side polarizing plate, the configuration is changed according to Reference Example 2. The elliptically polarizing plate A was obtained. In this case, the viewing angle becomes narrower than when the elliptically polarizing plate 2 is used, and the total thickness of the elliptically polarizing plate A is thick, so that assembly and adhesion of the module are difficult.

1 is a schematic cross-sectional view showing a layer structure of an IPS type liquid crystal display device produced in Example 5.

2 is a perspective dependence view of a comparison of an IPS type liquid crystal display device produced in Example 5.

Fig. 3 is a schematic cross-sectional view showing the layer structure of a VA liquid crystal display device produced in Example 6.

Fig. 4 is a view showing the dependence of the comparison of the VA type liquid crystal display device produced in the sixth embodiment.

Fig. 5 is a schematic cross-sectional view showing the layer structure of an IPS type liquid crystal display device produced in Comparative Example 1.

Fig. 6 is a view showing the dependence of the comparison of the IPS type liquid crystal display device produced in Comparative Example 1.

Fig. 7 is a view showing the dependence of the comparison of the IPS type liquid crystal display device produced in Comparative Example 2.

Claims (13)

An elliptically polarizing plate comprising at least a member in which a liquid crystal composition having a positive uniaxiality is vertically aligned in a liquid crystal state, and the alignment is fixed to a vertically aligned liquid crystal layer; and having a phase difference function a retardation film; and a linear polarizing plate having a laminated structure in which only one surface of the polarizing element is protected by a light-transmitting protective film; and the laminated structure having any one of the following (A) or (B): (A) Translucent protective film / polarizing element / retardation film / vertical alignment liquid crystal layer; (B) light transmissive protective film / polarizing element / vertical alignment liquid crystal layer / retardation film. The elliptically polarizing plate of the first aspect of the invention, wherein the vertical alignment liquid crystal layer comprises a liquid crystal composition containing a side chain type liquid crystalline polymer compound having an oxetane group, and is subjected to vertical liquid crystal state. After the alignment, the oxetane group is reacted to vertically align the vertical alignment liquid crystal layer. The elliptically polarizing plate according to claim 1 or 2, wherein the vertical alignment liquid crystal layer satisfies the following [1] and [2]: [1] 0 nm ≦ Re1 ≦ 20 nm [2] - 500 nm ≦ Rth1 ≦ -30 nm (Re1 refers to the in-plane retardation value of the vertical alignment liquid crystal layer; Rth1 refers to the thickness direction retardation value of the vertical alignment liquid crystal layer; and Re1 and Rth1 are Re1=(Nx1-Ny1)×d1[nm], respectively. Rth1=(Nx1-Nz1)×d1[nm]; further, d1 is the thickness of the above-mentioned vertical alignment liquid crystal layer, and Nx1 and Ny1 are as described above. The main refractive index in the vertical alignment liquid crystal layer, Nz1 refers to the main refractive index in the thickness direction, Nz1>Nx1≧Ny1). The elliptically polarizing plate according to any one of claims 1 to 3, wherein the retardation film satisfies the following [3] and [4]: [3] 20 nm ≦ Re2 ≦ 200 nm [4] 0 nm ≦ Rth2 ≦ 30 nm (wherein Re2 is the in-plane retardation value of the retardation film; Rth2 is the retardation value in the thickness direction of the retardation film; and Re2 and Rth2 are respectively Re2=(Nx2-Ny2)×d2[nm], Rth2 = (Nx2 - Nz2) × d2 [nm]; further, d2 means the thickness of the retardation film, Nx2 and Ny2 are the principal refractive indices in the plane of the retardation film, and Nz2 means the principal refractive index in the thickness direction. Nx2>Ny2≧Nz2). The elliptically polarizing plate according to any one of claims 1 to 4, which is formed by laminating at least one or more optical films. The elliptically polarizing plate according to any one of claims 1 to 5, wherein the light-transmitting protective film is a cellulose triacetate or a cycloolefin polymer. The elliptically polarizing plate according to any one of claims 1 to 6, wherein the total film thickness is within 175 μm. A method for producing an elliptically polarizing plate is carried out by at least the following steps: (1) In the first step, the light-transmitting protective film is bonded to the polarizing element via the adhesive layer 1 to obtain a light-transmitting protective film/ Next, the layered body (I) composed of the layer 1 and the polarizing element; (2) the second step of forming a liquid crystal having positive uniaxiality on the retardation film a layer of the composition, after the layer is vertically aligned, a vertical alignment liquid crystal layer to which the alignment is fixed is formed, and a laminate (II) composed of a retardation film/vertical alignment liquid crystal layer is obtained; and (3) a third step The retardation film side of the laminate (II) is bonded to the polarizing element side of the laminate (I) via the adhesive layer 2 to obtain a light-transmitting protective film/adhesive layer 1/polarizing element/ Then, an elliptically polarizing plate composed of a layer 2 / a retardation film / a vertical alignment liquid crystal layer is used. A method for producing an elliptically polarizing plate is carried out by at least the following steps: (1) In the first step, the light-transmitting protective film is bonded to the polarizing element via the adhesive layer 1 to obtain a light-transmitting protective film/ Then, the layered body (I) composed of the layer 1 and the polarizing element; (2) the second step is to form a layer of a liquid crystal composition exhibiting a positive uniaxiality on the retardation film, and the layer is vertically aligned. Forming a vertical alignment liquid crystal layer to be aligned, and obtaining a laminate (II) composed of a retardation film/vertical alignment liquid crystal layer; and (3) a third step of vertically aligning the laminate body (II) The liquid crystal phase side is bonded to the polarizing element side of the laminated body (I) via the adhesive layer 2, and a translucent protective film/adhesive layer 1/polarizing element/adhesive layer 2/vertical alignment liquid crystal layer/phase is obtained. An elliptically polarizing plate composed of a poor film. A method for producing an elliptically polarizing plate is carried out by at least the following steps: (1) In the first step, the light-transmitting protective film is bonded to the polarizing element via the adhesive layer 1 to obtain a light-transmitting protective film/ Substrate layer 1 / polarized element structure The laminated body (I); (2) The second step is to form a layer of a liquid crystal composition exhibiting positive uniaxiality on the alignment substrate, and to perform vertical alignment of the layer to form a vertical alignment for immobilizing the alignment The liquid crystal layer obtains the layered body (III) composed of the alignment substrate/vertical alignment liquid crystal layer; (3) the third step is to vertically phase the liquid crystal layer side of the layered body (III) via the adhesive layer 2 and phase After the differential film is bonded, the alignment substrate is peeled off and the vertical alignment liquid crystal layer is transferred onto the retardation film to obtain a laminate (IV) composed of the retardation film/adhesive layer 2/vertical alignment liquid crystal layer; 4) In the fourth step, the retardation film side of the laminate (IV) is bonded to the polarizing element side of the laminate (I) via the adhesive layer 3 to obtain a light-transmitting protective film/adhesive layer. 1 / polarizing element / adhesive layer 3 / retardation film / adhesive layer 2 / vertical alignment liquid crystal layer composed of an elliptically polarizing plate. A method for producing an elliptically polarizing plate is carried out by at least the following steps: (1) In the first step, the light-transmitting protective film is bonded to the polarizing element via the adhesive layer 1 to obtain a light-transmitting protective film/ a layered body (I) composed of a layer 1 and a polarizing element; (2) a second step of forming a layer of a liquid crystal composition exhibiting a positive uniaxiality on the alignment substrate, and then vertically aligning the layer Forming a vertical alignment liquid crystal layer to be aligned, and obtaining a layered body (III) composed of an alignment substrate/vertical alignment liquid crystal layer; (3) a third step of vertically aligning the layered body (III) toward the liquid crystal layer side through After bonding with the retardation film by the adhesive layer 2, the alignment substrate is peeled off and the vertical alignment liquid crystal layer is transferred onto the retardation film to obtain a phase difference film/adhesive layer 2/vertical alignment liquid crystal layer. The laminate (IV); and (4) the fourth step of bonding the vertical alignment liquid crystal layer side of the laminate (IV) to the polarizing element side of the laminate (A) via the adhesive layer 3, thereby obtaining An elliptically polarizing plate composed of a light-transmitting protective film/adhesive layer 1/polarizing element/adhesive layer 3/vertical alignment liquid crystal layer/adhesive layer 2/retardation film. A liquid crystal display device in which an elliptically polarizing plate according to any one of claims 1 to 7 is disposed on at least one side of a liquid crystal cell. The liquid crystal display device of claim 12, wherein the liquid crystal cell is a VA liquid crystal cell or an IPS liquid crystal cell.