KR20060090172A - Optical anisotropic film and liquid crystal display device - Google Patents

Abstract

(Problem) The optically anisotropic film which can be produced by the simple method which contributes to the improvement of the viewing angle of a liquid crystal display device is provided.

(Solution means) An optically anisotropic film containing a rod-shaped compound represented by the following general formula (I). Wherein P ¹ and P ² are each independently a polymerizable group or a hydrogen atom; X ^{1 to} X ³ are each independently an alkylene group or a substituted alkylene group; L ¹ and L ⁶ are each independently a single bond, —O—CO—O—, —O—, —CO—O—, or —O—CO—; L ² and L ⁵ are each independently a single bond, —CO—O—, —O—CO—, —C≡C— or —CH═CH—; L ³ and L ⁴ are each independently —O—CO—O—, —CO—O—, —O—, —O—CO—, —C≡C— or —CH═CH—; Y ^1- Y ⁴ Are each independently a halogen atom, a cyano group, an alkyl group, an alkenyl group or an alkoxy group; n1 to n4 are each independently 0 to 4; s and t are 0-5 each independently, and the sum of s and t is 1 or more.

 (Formula 1)

Optically anisotropic film, liquid crystal display device.

Description

Optical anisotropic film and liquid crystal display device {OPTICAL ANISOTROPIC FILM AND LIQUID CRYSTAL DISPLAY DEVICE}

1 is a schematic diagram showing an example of a pixel region of a liquid crystal display of the present invention.

2 is a schematic view showing an example of a liquid crystal display of the present invention.

3 is a schematic view showing another example of the liquid crystal display of the present invention.

* Explanation of symbols for the main parts of the drawings *

1: liquid crystal element pixel region

2: pixel electrode

3: display electrode

4: rubbing direction

5a, 5b: director of liquid crystal compound at the time of black display

6a, 6b: director of liquid crystal compound in white display

7a, 7b, 19a, 19b: protective film for polarizing film

8, 20: polarizing film

9, 21: polarization transmission axis of polarizing film

10: first phase difference region

11: slow axis of the first retardation region

12: second phase difference region

13, 17: cell substrate

14, 18: cell substrate rubbing direction

15: liquid crystal layer

16: Slow axis direction of liquid crystal layer

(Patent Document 1) Japanese Patent Application Laid-Open No. 9-80424

(Patent Document 2) Japanese Unexamined Patent Publication No. Hei 10-54982

(Patent Document 3) Japanese Patent Application Laid-Open No. 11-202323

(Patent Document 4) Japanese Patent Application Laid-Open No. 9-292522

(Patent Document 5) Japanese Patent Application Laid-Open No. 11-133408

(Patent Document 6) Japanese Patent Application Laid-Open No. 11-305217

(Patent Document 7) Japanese Unexamined Patent Publication No. 10-307291

(Patent Document 8) Japanese Patent Application Publication No. 2000-514202

(Patent Document 9) JP 10-319408 A

(Patent Document 10) Japanese Unexamined Patent Publication No. Hei 6-331826

The present invention relates to an optically anisotropic film using a rod-shaped compound expressing a smectic phase and a liquid crystal display device using the film. In particular, the present invention provides an optically anisotropic film useful as a phase difference layer used in a liquid crystal display device in an in-plane switching mode (IPS mode), which is displayed by applying a lateral electric field to a liquid crystal molecule oriented in a horizontal direction, and an IPS mode. It relates to a liquid crystal display device.

BACKGROUND ART A liquid crystal display device using a so-called in-plane switching (IPS) mode in which a transverse electric field is applied to a liquid crystal is being developed not only for monitor use but also for TV use, and the brightness of the screen is greatly improved. For this reason, the microscopic light leakage in the inclined incidence direction of the diagonal position at the time of black display which did not become a problem in these operation modes conventionally appeared as a cause of the fall of display quality.

As one of the means of improving the viewing angle of this color tone or black display, disposing an optical compensation material having birefringence property between the liquid crystal layer and the polarizing plate is also examined in the IPS mode. For example, when a birefringent medium having an optical axis having a function of compensating the increase and decrease of retardation of a liquid crystal layer at an inclination, is orthogonal to each other between the substrate and the polarizing plate, the white display or halftone display is directly viewed in the oblique direction. It is disclosed that coloring can be improved (refer patent document 1). Moreover, birefringence is positive as a method of using the optical compensation film which consists of a styrene-type polymer which has negative intrinsic birefringence, and a discotic liquid crystalline compound (refer patent document 2, 3, 4), or an optical compensation film. ), A method of combining a film having an optical axis in-plane with a film having a birefringence and a film having an optical axis in the normal direction of the film (see Patent Document 5), and a biaxial optical compensation sheet having a delay of 1/2 wavelength. The method of using (refer patent document 6) and the method of using the film which has a negative delay as a protective film of a polarizing plate, and forming the optical compensation layer which has a positive retardation on this surface (refer patent document 7) are proposed.

However, since most of the proposed methods improve the viewing angle by eliminating the birefringent anisotropy of the liquid crystal in the liquid crystal cell, when the orthogonal polarizer is viewed from the oblique direction, light leakage based on the deviation from the orthogonality of the polarization axis crossing angles is sufficiently solved. There is a problem that can not be. In addition, in the optical compensation sheet for IPS mode liquid crystal cells which perform optical compensation with a stretched birefringent polymer film, it is necessary to use a plurality of films, and as a result, the thickness of the optical compensation sheet increases, which is disadvantageous for thinning the display device. Moreover, since an adhesion layer is used for lamination of a stretched film, the adhesion layer shrinks by the change of temperature-humidity, and defects, such as peeling and curvature between films, may arise.

On the other hand, as an optical compensation material of IPS, the optically anisotropic material produced by orienting a liquid crystal material perpendicularly | vertically and fixing the orientation state is known. In the case of forming an optically anisotropic material using a liquid crystal material, it is common to fix it nematically, but in recent years, demand for display characteristics of a monitor is becoming difficult, and micro-uniformity is not sufficient as an anisotropic material immobilized in nematic shape. There is a need for improvement. With respect to such a request, an optically anisotropic material produced by immobilizing a smectic phase has been proposed (Patent Documents 8, 9, and 10).

However, in patent documents 8 and 9, it is unsuitable for manufacture at the industrial level, such as requiring the orientation processing special for the smectic phase orientation, or producing a retardation area | region on a glass substrate. Moreover, in patent document 10, since the vertical orientation of a polymer liquid crystal material was carried out, alignment took a long time and was also unsuitable for manufacture on an industrial level. In addition, these documents do not describe the light leakage required as the optical compensation film. Moreover, even if the liquid crystal compound in the literature is used, it is not sufficient to suppress light leakage, and it is required to make the light leakage smaller.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and an object thereof is to provide an IPS type liquid crystal display device having a simple configuration and significantly improving not only display quality but also light leakage. Moreover, this invention makes it a subject to provide the optically anisotropic film which can be produced by the simple method which contributes to the improvement of the viewing angle of a liquid crystal display device, especially an IPS type liquid crystal display device.

The subject of this invention was solved by the following [1]-[10].

[1] An optically anisotropic film containing a rod-shaped compound represented by the following general formula (I).

(Formula 1)

[Wherein, P ¹ and P ² are each independently a polymerizable group or a hydrogen atom; X ^{1 to} X ³ are each independently an alkylene group or a substituted alkylene group; L ¹ and L ⁶ are each independently a single bond, —O—CO—O—, —O—, —CO—O—, or —O—CO—; L ² and L ⁵ are each independently a single bond, —CO—O—, —O—CO—, —C≡C— or —CH═CH—; L ³ and L ⁴ are each independently —O—CO—O—, —CO—O—, —O—, —O—CO—, —C≡C— or —CH═CH—; Y ^{1 to} Y ⁴ are each independently a halogen atom, a cyano group, an alkyl group, an alkenyl group or an alkoxy group; n1 to n4 are each independently 0 to 4; s and t are each independently 0-5, and the sum of s and t is 1 or more].

[2] The optically anisotropic film according to [1], wherein the rod-shaped compound represented by the general formula (I) is fixed in a smectic shape.

[3] The optically anisotropic film according to [2], wherein the crosslinked product of the compound represented by Formula (I) is immobilized in a vertically aligned state.

[4] The optically anisotropic film according to [1] to [3], in which the retardation layer contains an additive for promoting vertical alignment at the air interface of the compound represented by formula (I).

[5] The optically anisotropic film according to [1] to [4], wherein the retardation layer contains an additive which promotes vertical alignment at the alignment film interface of the compound represented by formula (I).

[6] a liquid crystal cell including at least a first polarizing film, a first retardation region, a second retardation region, and a liquid crystal layer sandwiched between a pair of substrates, wherein the liquid crystal molecules in the black display A liquid crystal display device oriented substantially parallel to the surface of a substrate, wherein the delay Re of the first retardation region is 20 nm to 150 nm, the value Nz of the first retardation region is 1.5 to 7 and the delay of the second retardation region. Re is substantially 0 nm, the delay Rth of a 2nd phase difference region is -80nm--400nm, and a said 2nd phase difference region contains the optically anisotropic film in any one of [1]-[5], The crosslinked product of the compound represented by formula (I) contained in the optically anisotropic film is fixed in a substantially vertically aligned state, and the transmission axis of the first polarizing film is parallel to the slow axis direction of the liquid crystal molecules at the time of black display. One liquid crystal display.

[7] The first polarizing film, the first retardation region, the second retardation region, and the liquid crystal cell are arranged in this order, and the slow axis of the first retardation region is substantially the same as the transmission axis of the first polarization film. The liquid crystal display device as described in [6] parallel.

[8] The first polarizing film, the second retardation region, the first retardation region, and the liquid crystal cell are arranged in this order, and the slow axis of the first retardation region is substantially the transmission axis of the first polarization film. The liquid crystal display device as described in [6] orthogonal to.

[9] Further comprising a second polarizing film having a transmission axis orthogonal to the transmission axis of the first polarizing film, wherein the first and second polarizing films comprise the first phase difference region, the second phase difference region and the liquid crystal cell. The liquid crystal display device according to any one of [6] to [8], which is sandwiched between them.

[10] a pair of protective films disposed with the first polarizing film and / or the second polarizing film interposed therebetween, wherein the phase difference Rth in the thickness direction of the side protective film close to the liquid crystal layer among the pair of protective films is 40 nm or less; The liquid crystal display device in any one of [6]-[9].

[11] A pair of protective films having the first polarizing film and / or the second polarizing film sandwiched therebetween, wherein the side protective film close to the liquid crystal layer of the pair of protective films is a cellulose acylate film or a norbornene-based film; The liquid crystal display device according to any one of [6] to [10].

Embodiment of the invention

EMBODIMENT OF THE INVENTION Below, this invention is demonstrated in detail. In addition, the numerical range displayed using "-" in this specification means the range which includes the numerical value described before and after "-" as a lower limit and an upper limit. In addition, in this specification, "parallel" and "orthogonal" mean that it exists in the range less than an exact angle ± 10 degrees. It is preferable that the error with an exact angle is less than +/- 5 degrees, and, as for this range, it is more preferable that it is less than +/- 2 degrees. In addition, "substantially vertical" means that it exists in the range of less than +/- 20 degrees from an exact vertical angle. It is preferable that the error with an exact angle is less than +/- 15 degrees, and, as for this range, it is more preferable that it is less than +/- 10 degrees. In addition, a "ground axis" means the direction in which a refractive index becomes largest. In addition, the measurement wavelength of refractive index is a value in (lambda) = 550 nm of visible range unless there is particular notice.

In this specification, unless otherwise indicated, a "polarizing plate" is cut to a size to be mounted on a long polarizing plate and a liquid crystal device (in this specification, "foundation" shall also include "punching", "cutting", etc.). ) Is used to include both sides of the polarizing plate. In addition, in this specification, although a "polarizing film" and a "polarizing plate" are distinguished and used, a "polarizing plate" shall mean the laminated body which has a transparent protective film which protects this polarizing film on at least one surface of a "polarizing film."

First, the rod-shaped compound used for preparation of the optically anisotropic film of this invention is demonstrated.

[Bar compound]

This invention uses the rod compound represented by following formula (I).

(Formula 2)

The rod compound is a well-known concept in the molecular structure of the rod liquid crystal compound, and is described in (Liquid Crystal Handbook Editing Committee Edition, Liquid Crystal Handbook; Shige Iwayanagi, Liquid Crystal).

In Formula (I), P <^1> and P <^2> respectively independently represent a polymeric group or a hydrogen atom, and it is preferable that the magnitude | size of the phase difference like an optical compensation film does not change with heat to the liquid crystalline compound represented by Formula (I). when used in the optical film is, P ¹ and P ² is preferably a polymerizable group. It is preferable that it is a functional group in which addition polymerization reaction or condensation polymerization reaction is possible. The example of a polymeric group is shown below.

(Formula 3)

Moreover, it is especially preferable that a polymeric group is a functional group in which addition polymerization reaction is possible. As such a polymerizable group, a polymerizable ethylenically unsaturated group or a ring-opening polymerizable group is preferable.

Examples of the polymerizable ethylenically unsaturated group include the following formulas (M-1) to (M-6).

(Formula 4)

In formulas (M-3) and (M-4), R represents a hydrogen atom or an alkyl group. As R, a hydrogen atom or a methyl group is preferable. Among the above (M-1) to (M-6), (M-1) or (M-2) is preferred, and (M-1) is most preferred.

As a ring-opening polymerizable group, a cyclic ether group is preferable, Especially, an epoxy group or an oxetanyl group is more preferable, and an epoxy group is the most preferable.

One or two or more CH groups present in the phenylene group of formula (I) may be substituted with a nitrogen atom.

X ^{1 to} X ³ are each independently an alkylene group or a substituted alkylene group, and may have a branched structure. X ¹ and X ³ The number of carbon atoms in the alkylene group may be, for example, 1 to 30, preferably 1 to 20, more preferably 1 to 12. In X <^2> , the number of carbon atoms of an alkylene group may be 1-40, for example, It is preferable that it is 5-30, It is more preferable that it is 10-20. X ^{1 to} X ³ With respect to the substituted alkylene group in, at least one non-adjacent CH ₂ group may be substituted with -O-, -CO-O-, -O-CO-, -O-CO-O-, -CO-, And / or one or more H atoms may be a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, alkoxy group (eg methoxy group, ethoxy group, isopropoxy group), alkyl group (eg methyl group) , Ethyl group, isopropyl group). However, it is preferable that X <^1> -X <^3> is an unsubstituted alkylene group.

L ¹ and L ⁶ Are each independently a single bond, -O-CO-O-, -O-, -CO-O- or -O-CO-, and are preferably -O-. L ² and L ⁵ are each independently a single bond, —CO—O—, —O—CO—, —C≡C— or —CH═CH—, and L ² Is preferably a single bond or -CO-O-, and L ⁵ is preferably a single bond or -O-CO-. L ³ and L ⁴ are each independently —O—CO—O—, —CO—O—, —O—, —O—CO—, —C≡C— or —CH═CH—, and —O—CO Preference is given to -O-, -CO-O-, -O- or -O-CO-.

Y ^1- Y ⁴ Each independently represents a hydrogen atom, a halogen atom (eg fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, alkyl group (eg methyl group, ethyl group, isopropyl group), alkenyl group, or alkoxy group ( Methoxy group, ethoxy group, isopropoxy group), and a hydrogen atom or a fluorine atom is preferable.

n1-n4 are 0-4 each independently, 0-2 are preferable and 0 is more preferable.

s and t are 0-5 each independently, and the sum of s and t is 1 or more. 1-4 are respectively independently preferable as s and t, and it is more preferable that s and t are 1-3 each independently.

The repeating unit represented by s formulas (II) can independently determine Y ¹ , n ¹ and L ² in each unit. Further, repeating units represented by formulas t (Ⅲ), can each independently determine the Y ^4, L ^5, and n4 in the respective units.

(Formula 5)

(Formula 6)

Below, the example of the rod-shaped compound represented by Formula (I) is shown.

(Formula 7)

(Formula 8)

Formula 9

Formula 10

Formula 11

(Formula 12)

(Formula 13)

(Formula 14)

Among the rod-shaped compounds represented by General Formula (I), there are also compounds that can exhibit liquid crystallinity alone. However, you may show liquid crystallinity by mixing this rod compound with another liquid crystal. As for the liquid crystal phase to express, a smectic A phase is preferable.

When using the rod-shaped compound represented by general formula (I) mixed with another liquid crystalline compound, the ratio with respect to the whole liquid crystalline molecule of the rod-shaped compound represented by general formula (I) is 1-99 mass%, , 10-98 mass% is more preferable, and 30-95 mass% is the most preferable.

It is more preferable that the liquid crystalline compound to be used together is a rod-like liquid crystalline compound than the disk-shaped liquid crystalline compound. Other rod-like liquid crystalline compounds are described, for example, in Makromol. Chem., 190, 2255 (1989), Advanced Materials 5, 107 (1993), U.S. Patent No. 4683327, 5622648, 5770107, WO 95/22586, 95/24455 No. 97/00600, No. 98/23580, No. 98/52905, JP-A-272551, No. 6-16616, No. 7-110469, No. 11-80081, and Japan The compound described in Unexamined-Japanese-Patent No. 2001-328973 etc. is mentioned.

0 degreeC-300 degreeC is preferable, as for the temperature range of a liquid crystal state, 10 degreeC-250 degreeC is more preferable, and 20 degreeC-200 degreeC is the most preferable.

The optically anisotropic film of this invention contains the crosslinked material of the rod-shaped compound represented by the said General formula (I), The crosslinked material of this rod-shaped compound is characterized by the orientation being fixed in the smectic shape.

EMBODIMENT OF THE INVENTION Below, one Embodiment of the liquid crystal display device of this invention using this optically anisotropic film is demonstrated using drawing for the optically anisotropic film of this invention. 1: is a schematic diagram which shows the example of the pixel area of the liquid crystal display device of this invention. 2 and 3 are schematic diagrams of one embodiment of the liquid crystal display device of the present invention.

[Liquid crystal display device]

The liquid crystal display device shown in FIG. 2 includes the polarizing films 8 and 20, the first retardation region 10, the second retardation region 12, the substrates 13 and 17, and the liquid crystal layer 15 sandwiched between both substrates. Has The polarizing films 8 and 20 are sandwiched and supported between the protective films 7a and 7b and the protective films 19a and 19b, respectively.

In the liquid crystal display of Fig. 2, the liquid crystal cell is composed of the substrates 13 and 17 and the liquid crystal layer 15 sandwiched therebetween. The product (Δn · d) of the thickness (d (μm)) of the liquid crystal layer and the refractive index anisotropy (Δn) is in the range of 0.2 to 0.4 μm in the IPS type having no torsion structure in the transmission mode. In this range, since the white display brightness is high and the black display brightness is small, a bright and high contrast display device is obtained. The alignment film (not shown) is formed in the surface which contacts the liquid crystal layer 15 of the board | substrate 13 and 17, The liquid crystal molecule is orientated substantially parallel with respect to the substrate surface, and the rubbing process direction 14 implemented on the alignment film And 18) and the like, and the liquid crystal molecular alignment direction in the voltage-free state or the low-applied state is controlled. Moreover, the electrode (not shown in FIG. 2) which can apply voltage to liquid crystal molecule is formed in the inner surface of the board | substrate 13 or 17. FIG.

In FIG. 1, the orientation of the liquid crystal molecule in the one pixel area | region of the liquid crystal layer 15 is typically shown. 1 shows the orientation of liquid crystal molecules in a region having a very small area corresponding to one pixel of the liquid crystal layer 15 in the rubbing direction 4 of the alignment film formed on the inner surfaces of the substrates 13 and 17, and It is a schematic diagram shown with the electrodes 2 and 3 which can apply voltage to the liquid crystal molecules formed on the inner surfaces of the substrates 13 and 17. In the case of active driving using a nematic liquid crystal having positive dielectric anisotropy as the field effect type liquid crystal, the liquid crystal molecular alignment directions in the voltage-free state or the low applied state are 5a and 5b, and black display is obtained at this time. When applied between the electrodes 2 and 3, the liquid crystal molecules change their alignment directions in the 6a and 6b directions depending on the voltage. Usually, bright display is performed in this state.

2, the transmission axis 9 of the polarizing film 8 and the transmission axis 21 of the polarizing film 20 are orthogonal to each other. The slow axis 11 of the first retardation region 10 is parallel to the transmission axis 9 of the polarizing film 8 and the slow axis direction 16 of the liquid crystal molecules in the liquid crystal layer 15 at the time of black display.

In the liquid crystal display device shown in FIG. 2, the configuration in which the polarizing film 8 is sandwiched between two protective films 7a and 7b is shown. However, the protective film 7b may not be provided. In addition, although the polarizing film 20 is sandwiched between two protective films 19a and 19b, the protective film 19a on the side close to the liquid crystal layer 15 may be omitted. In the aspect of FIG. 2, the first phase difference region and the second phase difference region may be disposed between the liquid crystal cell and the polarizing film on the viewing side with reference to the position of the liquid crystal cell, and between the liquid crystal cell and the polarizing film on the back side. It may be arranged in. In this embodiment, the second retardation region is arranged closer to the liquid crystal cell in any configuration.

Another embodiment of the present invention is shown in FIG. 3. In FIG. 3, the number attached to each member of the liquid crystal display device is the same as that of FIG. In the liquid crystal display of FIG. 3, the second retardation region 12 is disposed between the polarizing film 8 and the first retardation region 10. In the liquid crystal display of FIG. 3, the protective film 7b or the protective film 19a may not be provided. In the aspect shown in FIG. 3, in the first phase difference region 10, the slow axis 11 is the ground of the liquid crystal molecules in the transmission axis 9 of the polarizing film 8 and the liquid crystal layer 15 in black display. It is arranged to be orthogonal to the axial direction 16. Moreover, in the aspect of FIG. 3, the 1st phase difference area | region and the 2nd phase difference area may be arrange | positioned between the liquid crystal cell and the polarizing film of the visual recognition side with respect to the position of a liquid crystal cell, and the liquid crystal cell and the polarization of a back side It may be arranged between the films. In this embodiment, in any configuration, the first retardation region is arranged closer to the liquid crystal cell.

In the liquid crystal display device shown in FIG. 2 and FIG. 3, the delay Re of the first retardation region 10 is 20 nm to 150 nm, and the value Nz of the first retardation region 10 is 1.5 to 7. On the other hand, the delay Re of the second retardation region 12 is substantially 0 nm, and the delay Rth of the second retardation region 12 is -80 nm to -400 nm. Moreover, the 2nd phase difference area | region 12 contains the optically anisotropic film of this invention containing the crosslinked material of the compound represented by the said Formula (I) in which orientation was fixed to the smectic phase. It may consist only of the optically anisotropic film of this invention. Details related to optical characteristics of the first phase difference region and the second phase difference region will be described later.

In addition, although the aspect of the display apparatus of the transmissive mode provided with the upper polarizing plate and the lower polarizing plate was shown in FIG.2 and FIG.3, this invention may be the aspect of the reflection mode provided with only one polarizing plate, and in this case, it can Since the optical path is doubled, the optimum value of Δn · d is about 1/2 of the above. The liquid crystal cell used in the present invention is not limited to the IPS mode, and any liquid crystal cell can be preferably used as long as the liquid crystal molecules are aligned substantially parallel to the surfaces of the pair of substrates at the time of black display. In this example, there are ferroelectric liquid crystal display devices, antiferroelectric liquid crystal display devices, and ECB type liquid crystal display devices.

The liquid crystal display device of this invention is not limited to the structure shown in FIGS. 1-3, and may contain the other member. For example, you may arrange a color filter between a liquid crystal layer and a polarizing film. Moreover, you may perform anti-reflective processing or hard coating on the protective film surface of a polarizing film. Moreover, you may use the thing which provided electroconductivity to the structural member. Moreover, when using as a transmission type, the backlight which uses a cold cathode or a hot cathode fluorescent tube, or a light emitting diode, a field emission element, and an electroluminescent element as a light source can be arrange | positioned at the back surface. In this case, the arrangement of the backlight may be the upper side or the lower side of FIGS. 2 and 3. In addition, a reflective polarizing plate, a diffusion plate, a prism sheet, or a light guide plate may be disposed between the liquid crystal layer and the backlight. As described above, the liquid crystal display device of the present invention may be a reflection type, and in this case, only one polarizing plate may be disposed on the observation side, and a reflective film is disposed on the rear surface of the liquid crystal cell or the inner surface of the lower substrate of the liquid crystal cell. do. Of course, it is also possible to form the front light using the said light source on the liquid crystal cell observation side.

The liquid crystal display device of the present invention includes an image direct view type, an image projection type, and a light modulation type. As for this invention, the aspect applied to the active-matrix liquid crystal display device which used the 3-terminal or 2-terminal semiconductor element like TFT and MIM is especially effective. Of course, the aspect applied to the passive matrix liquid crystal display device called time division drive is also effective.

Hereinafter, the preferable optical characteristics of the optically anisotropic film used for the liquid crystal display device of this invention and the various members which can be used for a liquid crystal display device, the material used for a member, its manufacturing method, etc. are demonstrated in detail.

In this specification, Re ((lambda)) and Rth ((lambda)) represent the in-plane delay in the wavelength (lambda), and the delay of the thickness direction, respectively. Re (λ) is measured by injecting light having a wavelength of λ nm in the film normal direction in KOBRA 21ADH (manufactured by Oji Measurement Instruments Co., Ltd.). Rth (λ) is the Re (λ) and the in-plane slow axis (determined by KOBRA 21ADH) as the inclination axis (rotation axis) to inject light having a wavelength of λnm in a direction inclined at + 40 ° with respect to the film normal direction. The measured delay value and the delay value measured in the total 3 directions of the delay values measured by injecting light having a wavelength of λ nm in a direction inclined at -40 ° with respect to the film normal direction using the in-plane slow axis as the tilt axis (rotation axis). KOBRA 21ADH is calculated based on the assumption of the average refractive index and the input film thickness value. Here, the assumption of the average refractive index may be a polymer handbook (JOHN WILEY & SONS, INC) and catalog values of various optical films. The thing which does not know the value of an average refractive index in advance can be measured with an Abbe refractometer. The average refractive index values of the main optical films are illustrated below: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethylmethacrylate (1.49), polystyrene (1.59). By inputting the assumption values and the film thicknesses of these average refractive indices, KOBRA 21ADH calculates nx, ny, and nz. From this calculated nx, ny and nz, Nz = (nx-nz) / (nx-ny) is further calculated.

[First Phase Difference Area]

In the first phase difference region included in the liquid crystal display device of the present invention, the delay Re is 20 nm to 150 nm. In order to more effectively reduce light leakage in the oblique direction, it is more preferable that Re of the first retardation region is 40 nm to 115 nm, and still more preferably 60 nm to 95 nm. Moreover, Nz is 1.5-7. In order to more effectively reduce light leakage in the oblique direction, Nz of the first retardation region is more preferably 2.0 to 5.5, and still more preferably 2.5 to 4.5.

Basically, as long as the said 1st phase difference area | region has the said optical characteristic, it does not restrict | limit especially about the material and form. For example, the retardation film which consists of a birefringent polymer film, the retardation film formed by apply | coating a high molecular compound on a transparent support body, and heating-salt film, and the retardation layer formed by apply | coating or transferring a low molecular weight or a polymer liquid crystalline compound on a transparent support body, etc. Any of these can be used as the first phase difference region. Moreover, you may laminate | stack and use each.

As a birefringent polymer film, what is excellent in controllability, transparency, and heat resistance of a birefringence characteristic is preferable. In this case, the polymer material to be used is not particularly limited as long as it is a polymer capable of achieving a uniform biaxial orientation, but it is conventionally known and can be formed into a film by a solution casting method or an extrusion molding method, and is norbornene-based. Aromatic polymers such as polymers, polycarbonate polymers, polyallylate polymers, polyester polymers, polysulfones, cellulose acylates, or polymers in which two or three or more of these polymers are mixed. .

The biaxial orientation of the film is, for example, a longitudinal stretching method with a roll, a transverse stretching method with a tenter, or a biaxial stretching method with a film made of the thermoplastic resin produced by a suitable method such as an extrusion molding method or a flexible film forming method. It can achieve by extending | stretching process by etc. In the longitudinal stretching method using the roll described above, a suitable heating method such as a method of using a heating roll, a method of heating an atmosphere, or a method of using these in combination can be adopted. Moreover, in the biaxial stretching method by a tenter, suitable methods, such as the simultaneous biaxial stretching method by the whole tenter system, and the sequential biaxial stretching method by the roll tenter method, can be employ | adopted.

Moreover, it is preferable that there are few orientation nonuniformity and retardation nonuniformity. Although the thickness can be suitably determined by retardation etc., it is generally 1-300 micrometers from a viewpoint of thickness reduction, It is more preferable that it is 10-200 micrometers, It is further more preferable that it is 20-150 micrometers.

Examples of norbornene-based polymers include monomers such as norbornene and derivatives thereof, tetracyclododecene and derivatives thereof, dicyclopentadiene and derivatives thereof, and norbornene-based monomers such as metanotetrahydrofluorene and derivatives thereof. Ring-opening polymers of norbornene-based monomers, ring-opening copolymers of norbornene-based monomers with other monomers that can be ring-opened copolymerized, addition polymers of norbornene-based monomers, norbornene-based monomers and other copolymerizable with this Addition copolymer with a monomer, hydrogenated substance, etc. are mentioned. Among these, the ring-opening polymer hydride of a norbornene-type monomer is the most preferable from a viewpoint of heat resistance, mechanical strength, etc. The molecular weight of norbornene-based polymers, polymers of monocyclic cyclic olefins or polymers of cyclic conjugated dienes is appropriately selected according to the purpose of use, and is determined by gel permeation chromatography of a cyclohexane solution (toluene solution if the polymer resin is not dissolved). In the range of 5,000 to 500,000, preferably 8,000 to 200,000, more preferably 10,000 to 100,000, in terms of the weight average molecular weight in terms of one polyisoprene or polystyrene, the mechanical strength and the moldability of the film (A) are highly balanced and preferred. .

The acyl group of the cellulose acylate may be an aliphatic group or an allyl group, and is not particularly limited. They are alkylcarbonyl ester, alkenylcarbonyl ester, aromatic carbonyl ester, aromatic alkylcarbonyl ester, etc. of cellulose, for example, may have group substituted further, and the ester group which has 22 or less of total carbon numbers is preferable. As these preferable cellulose acylates, the acyl group of 22 or less total carbon atoms of an ester part (for example, acetyl, propionyl, butyroyl, valer, heptanoyl, octanoyl, decanoyl, dodecanoyl, tridecanoyl, hexa Decanoyl, octadecanoyl, etc.), an arylcarbonyl group (acrylic, methacryl, etc.), an allyl carbonyl group (benzoyl, naphthaloyl, etc.), cinnamoyl group. Among these, cellulose acetate, cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate stearate, cellulose acetate benzoate, and the like, and in the case of mixed esters, the ratio is not particularly limited, but the acetate is preferably 30 moles of the total ester. It is preferable that it is% or more.

Among these, a cellulose acylate is preferable, It is preferable that it is especially a photographic grade, The thing of the commercially available photographic grade can satisfy | fill and obtain the quality, such as viscosity average polymerization degree and substitution degree. As a manufacturer of cellulose triacetate of photographic grade, Daicel Chemical Industries, Ltd. (for example, LT-20, 30, 40, 50, 70, 35, 55, 105, etc.), Eastman Kodak Inc. For CAB-551-0.01, CAB-551-0.02, CAB-500-5, CAB-381-0.5, CAB-381-02, CAB-381-20, CAB-321-0.2, CAP-504-0.2, CAP -482-20, CA-398-3, etc.), Cortles, Hext, etc., and all can use the gradation cellulose acylate. In addition, for the purpose of controlling the mechanical or optical properties of the film, plasticizers, surfactants, retarders, UV absorbers and the like can be mixed. (Reference: Japanese Patent Laid-Open No. 2002-277632, Japanese Patent Laid-Open No. 2002- 182215).

As the method for molding the transparent resin into a sheet or film shape, for example, both a hot melt molding method and a solution casting method can be used. The hot melt molding method can be classified into extrusion molding method, press molding method, inflation molding method, injection molding method, blow molding method, stretch molding method and the like in more detail, but among these methods, in order to obtain a film having excellent mechanical strength, surface precision and the like, the extrusion molding method , Inflation molding and press molding are preferred, and extrusion molding is most preferred. Molding conditions are appropriately selected depending on the purpose of use and the molding method, but in the case of the hot melt molding method, the cylinder temperature is preferably set in the range of preferably 100 to 400 ° C, more preferably 150 to 350 ° C. The thickness of the sheet or film is preferably 10 to 300 µm, more preferably 30 to 200 µm.

Stretching of the sheet or film, when the glass transition temperature of the transparent resin is Tg, preferably at least in the temperature range of Tg-30 ° C to Tg + 60 ° C, more preferably in the temperature range of Tg-10 ° C to Tg + 50 ° C. In one direction, it is preferably carried out at a draw ratio of 1.01 to 2 times. Although the stretching direction should just be at least one direction, when the sheet | seat is obtained by extrusion molding, it is preferable that it is the mechanical flow direction (extrusion direction) of resin, and the extending | stretching method is free shrink uniaxial stretching method and width fixation. The uniaxial stretching method, the biaxial stretching method, etc. are preferable. Control of optical characteristics can be performed by controlling this draw ratio and heating temperature.

[Second phase difference region]

In the second retardation region of the liquid crystal display of the present invention, the delay Re is substantially 0 nm. The delay Rth in the thickness direction of the second retardation region is from -80 nm to -400 nm. The more preferable range of Rth of the second retardation region varies depending on the optical characteristics of the other optical member, and particularly, greatly varies according to Rth of the protective film (for example, triacetyl cellulose film) of the polarizing film located closer. In order to effectively reduce light leakage in the oblique direction, the Rth of the second retardation region is more preferably -100 nm to -340 nm, and further preferably -120 nm to -270 nm. On the other hand, Re of a 2nd phase difference area becomes a value of 0 vicinity. Specifically, the in-plane delay Re is preferably 0 to 50 nm, and more preferably 0 to 20 nm.

In the present invention, the second retardation region includes the optically anisotropic film of the present invention containing a crosslinked product of the rod-shaped compound represented by the formula (I) in which the orientation is fixed in a smectic phase. This optically anisotropic film is a phase difference layer which has positive birefringence. The second retardation region is a layer having at least one layer of the optically anisotropic film as the retardation layer. In addition, a plurality of retardation layers as well as one retardation layer may be stacked to form a second retardation region exhibiting the optical characteristics. Moreover, you may comprise a 2nd phase difference area so that the said optical characteristic may be satisfy | filled in the whole laminated body of a support body and retardation layer.

Moreover, in the 2nd phase difference area which the liquid crystal display device of this invention has, the crosslinked material of the compound represented by said Formula (I) contained in an optically anisotropic film is being immobilized in the substantially perpendicularly orientated state. Substantially perpendicular means that the angle which the film surface and the director of a rod-shaped liquid crystalline compound form is in the range of 70 degrees-90 degrees. These liquid crystalline compounds may be inclined or may be inclined so as to gradually change (hybrid alignment). Even in the case of oblique orientation or hybrid orientation, the average inclination angle is preferably 70 ° to 90 °, more preferably 80 ° to 90 °, and most preferably 85 ° to 90 °.

Hereinafter, of the optically anisotropic film (retardation layer containing the crosslinked material of the rod-shaped compound represented by said Formula (I) in which the orientation is being fixed to the smectic phase) of the optically anisotropic film of this invention used suitably for the 2nd phase difference area of this invention. A production method and materials other than the compound represented by the formula (I) used for the production will be described.

In forming the optically anisotropic film of the present invention, a rod-like compound represented by the formula (I) is used. For example, the composition containing the rod-shaped compound represented by said formula (I) can be formed by apply | coating on the alignment film of the transparent support body which has an oriented film, and then crosslinking a rod-shaped compound. The said composition can also contain one type of rod-shaped compound. Moreover, non-polymerizable (non-crosslinkable) liquid crystalline compounds other than a rod compound can also be used for the said composition. About each liquid crystalline compound used individually or in combination, you may form a nematic liquid crystal phase, a smectic liquid crystal phase, or a cholesteric liquid crystal phase. When apply | coating as mentioned later, although the composition which added the additives, such as a solvent and a polymerization initiator, is apply | coated, it is preferable to take the smectic liquid crystal phase in the temperature range to orientally fix as a liquid crystal composition in which the solvent volatilized in the heat-drying process. Is used.

The optically anisotropic film formed of the rod-shaped compound is, in addition to the rod-shaped compound, a coating liquid containing the following polymerization initiator, an air interface vertical alignment agent or other additives is applied to the alignment film on the support and vertically aligned as desired. It can form by fixing an orientation state. When formed on a temporary support body, it can also manufacture by transferring the phase difference layer on a support body. In addition, a plurality of retardation layers as well as one retardation layer may be laminated to form a second retardation region exhibiting the above optical characteristics. When forming on a temporary support body, and laminating | stacking a some retardation layer, it can vertically orientate by adding a vertical alignment agent. In addition, it is preferable to perform fixing of an orientation state by the polymerization reaction of the polymeric group (P) introduce | transduced into a liquid crystalline compound, as mentioned later. Moreover, you may comprise a 2nd phase difference area so that the said optical characteristic may be satisfy | filled in the whole laminated body of a support body and a phase difference layer.

It is preferable to maintain the orientation state and to fix the liquid crystalline compound oriented vertically. It is preferable to perform fixation by the polymerization reaction of the polymeric group (P) introduce | transduced into a liquid crystalline compound. The polymerization reaction includes a thermal polymerization reaction using a thermal polymerization initiator and a photopolymerization reaction using a photopolymerization initiator. Photopolymerization reaction is preferred. Examples of photopolymerization initiators include α-carbonyl compounds (described in the specifications of US Pat. No. 23,684,1, 2367670), acyloinether (described in the specification of US Pat. No. 2448828), compounds of α-hydrocarbon substituted aromatic acyl ( U.S. Pat. No. 2722512, a multinuclear quinone compound (U.S. Pat.No.3046127, described in each specification in No. 2951758), a combination of a triarylimidazole dimer and p-aminophenylketone (described in the specification of U.S. Pat.No.3549367) , Acridine and phenazine compounds (Japanese Patent Laid-Open No. 60-105667, described in US Pat. No. 4,339850) and Oxadiazole compounds (described in US Pat. No. 4212970).

It is preferable that it is 0.01-20 mass% of solid content of a coating liquid, and, as for the usage-amount of a photoinitiator, it is more preferable that it is 0.5-5 mass%. It is preferable to use ultraviolet rays for light irradiation for the polymerization of the rod-like liquid crystalline molecules. It is preferable that it is 20mJ / cm <2> -50J / cm <2>, and, as for irradiation energy, it is more preferable that it is 100-800mJ / cm <2>. Moreover, you may irradiate light under heating conditions in order to accelerate photopolymerization reaction. It is preferable that the thickness of the 1st phase difference area | region containing the said optically anisotropic layer is 0.1-10 micrometers, It is more preferable that it is 0.5-5 micrometers, It is most preferable that it is 1-5 micrometers.

[Vertical Orientation Accelerator on the Alignment Film Interface Side]

The composition used in order to form the phase difference layer which comprises the optically anisotropic film of this invention may contain the vertical alignment promoter of the orientation film interface side. An onium salt can be used suitably as a vertical alignment promoter of the orientation film interface side. In the present invention, the onium salt contributes to the vertical alignment of the rod-like liquid crystal compound at the alignment film interface side. Examples of the onium salt include onium salts such as ammonium salts, sulfonium salts, and phosphonium salts. Preferably, it is a quaternary onium salt, Especially preferably, it is a quaternary ammonium salt.

Quaternary ammoniums are generally tertiary amines (eg trimethylamine, triethylamine, tributylamine, triethanolamine, N-methylpyrrolidine, N-methylpiperidine, N, N-dimethylpipepe Razine, triethylenediamine, N, N, N ', N'-tetramethylethylenediamine, etc.) or nitrogen-containing heterocycle (pyridine ring, picoline ring, 2,2'-bipyridyl ring, 4,4'-ratio) Pyridyl ring, 1,10-phenanthroline ring, quinoline ring, oxazole ring, thiazole ring, N-methylimidazole ring, pyrazine ring, tetrazole ring, etc. alkylation (Menschutkin reaction), alkenylation, alky Obtained by nilation or arylation.

As a quaternary ammonium salt, the quaternary ammonium salt which consists of nitrogen-containing heterocycles is preferable, Especially preferably, it is a quaternary pyridinium salt. Specifically, the compound shown below is mentioned, for example.

(Formula 15)

[Air Interface Vertical Alignment Agent]

Usually, since a liquid crystalline compound has the property which is inclined and orientated in the air interface side, it is necessary to orientately control a liquid crystalline compound in the air interface side in order to obtain the uniformly vertically aligned state. For this purpose, it is preferable to contain the agent which promotes the vertical orientation in the air interface of the compound represented by said Formula (I) in the composition used for formation of the said optically anisotropic film-forming. The said agent is a compound which is ubiquitous at the air interface side, and makes a function which orients a liquid crystalline compound vertically by the exclusion volume effect or an electrostatic effect, For example, the compound shown below is mentioned.

(Formula 16)

(Formula 17)

Formula 18

Moreover, the compound described in Unexamined-Japanese-Patent No. 2002-20363 and Unexamined-Japanese-Patent No. 2002-129162 can be used. In addition, the matters described in paragraphs [0072] to [0075] of JP 2004-53981 and paragraphs [0071] to [0078] of JP 2004-004688 are also applicable to the present invention as appropriate. .

[Alignment Film]

The alignment film has a function of defining the alignment direction of the liquid crystal molecules. However, the present invention relates to a homeotropic oriented liquid crystalline composition, and since there is no in-plane alignment direction, an alignment film is not essential to the present invention. The alignment film is used for forming the optically anisotropic film of the present invention, but the alignment film does not need to be included in the optically anisotropic film. However, it may be included. Since an alignment film can improve the uniformity of the orientation of a liquid crystalline composition, or can improve the adhesiveness between a polymer base material and an optically anisotropic layer, it can be used as needed. In addition, when the alignment state is fixed after alignment of the liquid crystalline compound, the alignment film may have been removed and thus may be removed. That is, it is also possible to manufacture only the optically anisotropic layer on the orientation film to which the orientation state was fixed on the polarizer, and to produce the polarizing plate which has an optically anisotropic layer.

The alignment film is an organic compound (e.g., ω-trichoic acid) by rubbing treatment of an organic compound (preferably a polymer), evaporation of an inorganic compound, formation of a layer having a micro group, or by a Langmuir blowjet method (LB film). And dioctadecyl methylammonium chloride, methyl stearyl acid). Moreover, the orientation film which an orientation function produces by provision of an electric field, provision of a magnetic field, or light irradiation is also known.

If necessary, the alignment film can be subjected to a rubbing treatment. The polymer used for an oriented film has a molecular structure which has a function which orientates a liquid crystalline molecule in principle.

In the present invention, in addition to the function of orienting the liquid crystal molecules, the side chain having a crosslinkable functional group (e.g., a double bond) is bonded to the main chain, or the crosslinkable functional group having the function of orienting the liquid crystal molecules is side chained. It is preferable to introduce in.

As the polymer used for the alignment film, any of polymers crosslinkable by themselves or polymers crosslinked by a crosslinking agent can be used, and a plurality of combinations thereof can be used.

Examples of the polymer include, for example, the methacrylate polymer, styrene polymer, polyolefin, polyvinyl alcohol, and modified polyvinyl alcohol, poly (N) described in paragraph [0022] of JP-A-8-338913. -Methylol acrylamide), polyester, polyimide, vinyl acetate polymer, carboxymethyl cellulose, polycarbonate and the like. Silane coupling agents can be used as the polymer. Water-soluble polymers (e.g. poly (N-methylolacrylamide), carboxymethylcellulose, gelatin, polyvinyl alcohol, modified polyvinyl alcohol) are preferred, gelatin, polyvinyl alcohol and modified polyvinyl alcohol are more preferred, and poly Most preferred are vinyl alcohol and modified polyvinyl alcohol. It is especially preferable to use together two types of polyvinyl alcohol or modified polyvinyl alcohol from which a polymerization degree differs.

70-100% is preferable and, as for the saponification degree of polyvinyl alcohol, 80-100% is more preferable. It is preferable that the polymerization degree of polyvinyl alcohol is 100-5000.

The side chain which has the function of orienting liquid crystalline molecules generally has a hydrophobic group as a functional group. The kind of specific functional group is determined according to the kind of liquid crystalline molecule and the orientation state required.

For example, as a modification group of modified polyvinyl alcohol, it can introduce | transduce by copolymerization modification, chain transfer modification, or block polymerization modification. Examples of the modified group include hydrophilic groups (carboxylic acid groups, sulfonic acid groups, phosphonic acid groups, amino groups, ammonium groups, amide groups, thiol groups, etc.), hydrocarbon groups having 10 to 100 carbon atoms, hydrocarbon groups having fluorine atom substitution, thioether groups, and polymerization. The group (unsaturated polymerizable group, epoxy group, azirinidyl group, etc.), alkoxy silyl group (trialkoxy, dialkoxy, monoalkoxy), etc. are mentioned. Specific examples of these modified polyvinyl alcohol compounds include, for example, paragraphs [0022] to [0145] of JP 2000-155216, and paragraphs [0018] to [0022] of JP 2002-62426. The thing described in the above, etc. are mentioned.

When the side chain having a crosslinkable functional group is bonded to the main chain of the alignment film polymer or the crosslinking functional group is introduced into the side chain having the function of orienting the liquid crystal molecules, the polyfunctional monomer contained in the polymer of the alignment film and the optically anisotropic layer May be copolymerized. As a result, not only between the polyfunctional monomer and the polyfunctional monomer, but also between the alignment film polymer and the alignment film polymer and between the polyfunctional monomer and the alignment film polymer are strongly bonded by covalent bonds. Therefore, by introducing a crosslinkable functional group into the alignment film polymer, the strength of the optical compensation sheet can be remarkably improved.

It is preferable that the crosslinkable functional group of an oriented film polymer contains a polymeric group similarly to a polyfunctional monomer. Specifically, the thing of Paragraph No. [0080]-[0100] etc. in Unexamined-Japanese-Patent No. 2000-155216 specification are mentioned, for example.

The alignment film polymer may be crosslinked using a crosslinking agent separately from the above crosslinkable functional groups.

Crosslinking agents include aldehydes, N-methylol compounds, dioxane derivatives, compounds which act by activating carboxyl groups, active vinyl compounds, active halogen compounds, isoxazoles and dialdehyde starches. You may use together 2 or more types of crosslinking agents. Specifically, the compound etc. which were described in Paragraph No. [0023]-[0024] of Unexamined-Japanese-Patent No. 2002-62426 specification are mentioned, for example. Aldehydes having high reaction activity, in particular glutaraldehyde, are preferred.

0.1-20 mass% is preferable with respect to a polymer, and, as for the addition amount of a crosslinking agent, 0.5-15 mass% is more preferable. It is preferable that it is 1.0 mass% or less, and, as for the quantity of the unreacted crosslinking agent which remains in an oriented film, it is more preferable that it is 0.5 mass% or less. By adjusting in this way, even if an alignment film is used for a long time in a liquid crystal display device, or it is left to stand for a long time in the atmosphere of high temperature, high humidity, sufficient durability without generating reticulation is obtained.

An orientation film can be formed by apply | coating on the transparent support body containing the said polymer which is an orientation film formation material, and a crosslinking agent fundamentally, heat-drying (crosslinking) and, if necessary, rubbing process. As mentioned above, after apply | coating on a transparent support body, what is necessary is just to perform a crosslinking reaction at arbitrary times. In the case of using a water-soluble polymer such as polyvinyl alcohol as the alignment film forming material, it is preferable that the coating liquid is a mixed solvent of an organic solvent (eg, methanol) and water having a bubble removing effect. It is preferable that the ratio of water: methanol is more than 0 and less than 99: 100 less than 1 by mass ratio, The ratio is more preferably greater than 0 and 91 or less: less than 100 less than 9 or more. Thereby, generation | occurrence | production of a bubble is suppressed and the defect of the layer surface of an oriented film, and also an optically anisotropic layer is remarkably reduced.

The coating method of the alignment film is preferably a spin coating method, a dip coating method, a curtain coating method, an extrusion coating method, a rod coating method or a roll coating method. In particular, the rod coating method is preferable. Moreover, as for the film thickness after drying, 0.1-10 micrometers is preferable. Heat drying can be performed at 20 degreeC-110 degreeC. In order to form sufficient crosslinking, 60 to 100 degreeC is preferable, and 80 to 100 degreeC is especially preferable. Although drying time can be made into 1 minute-36 hours, Preferably they are 1 minute-30 minutes. It is preferable to set pH also to the value suitable for the crosslinking agent to be used, and when glutaraldehyde is used, pH4.5-5.5, especially 5 are preferable.

An alignment film is formed on a transparent support body or the said undercoat layer. The alignment film can be obtained by crosslinking the polymer layer as described above, and then rubbing the surface if necessary.

The said rubbing process can apply the processing method employ | adopted widely as a liquid-crystal aligning process of LCD. That is, the method of obtaining an orientation by rubbing the surface of an oriented film in a fixed direction using paper, a gauze, a felt, rubber or nylon, polyester fiber, etc. can be used. Generally, it carries out by rubbing about several times using the cloth etc. which averaged the fiber of uniform length and thickness, and the like.

Next, the alignment film is functioned to align the liquid crystal molecules of the optically anisotropic layer formed on the alignment film. Thereafter, if necessary, the alignment film polymer and the polyfunctional monomer contained in the optically anisotropic layer are reacted, or the alignment film polymer is crosslinked using a crosslinking agent. It is preferable that the film thickness of an oriented film exists in the range of 0.1-10 micrometers.

[menstruum]

As a solvent used for preparation of a coating liquid, an organic solvent is used preferably. Examples of organic solvents include amides (eg N, N-dimethylformamide), sulfoxides (eg dimethyl sulfoxide), heterocyclic compounds (eg pyridine), hydrocarbons (eg benzene, hexane), alkyl halides ( Examples include chloroform, dichloromethane), esters (eg methyl acetate, butyl acetate), ketones (eg acetone, methyl ethyl ketone), ethers (eg tetrahydrofuran, 1,2-dimethoxyethane). Alkyl halides and ketones are preferred. You may use together 2 or more types of organic solvents. Application | coating of a coating liquid can be performed by a well-known method (for example, extrusion coating method, direct gravure coating method, reverse gravure coating method, die coating method).

[Other Materials in Retardation Layer]

A plasticizer, surfactant, a polymerizable monomer, etc. can be used together with said liquid crystalline compound, and the uniformity of a coating film, the intensity | strength of a film, the orientation of a liquid crystalline compound, etc. can be improved. It is preferable that these raw materials have compatibility with a liquid crystalline compound, and do not inhibit orientation.

A radically polymerizable or cationically polymerizable compound is mentioned as a polymerizable monomer. Preferably, it is a polyfunctional radically polymerizable monomer, and it is preferable that it is copolymerizable with the liquid crystal compound containing the said polymeric group. For example, the thing of Paragraph No. [0018]-[0020] is mentioned in Unexamined-Japanese-Patent No. 2002-296423 specification. It is preferable that the addition amount of the said compound exists in the range of 1-50 mass% with respect to rod-shaped liquid crystalline molecule generally, and exists in the range of 5-30 mass%.

Although a conventionally well-known compound is mentioned as surfactant, Especially a fluorine-type compound is preferable. Specifically, the compound described in Paragraph No. [0028]-[0056] of Unexamined-Japanese-Patent No. 2001-330725 can be mentioned, for example.

It is preferable that the polymer used with a liquid crystalline compound can thicken a coating liquid. Examples of the polymer include cellulose esters. As a preferable example of a cellulose ester, the thing of Paragraph No. of Unexamined-Japanese-Patent No. 2000-155216 specification is mentioned. It is preferable to exist in the range of 0.1-10 mass% with respect to liquid crystalline molecule, and, as for the addition amount of the said polymer so that the orientation of liquid crystalline molecules is not impaired, it is more preferable to exist in the range which is 0.1-8 mass%.

[Support]

In this invention, you may form the optically anisotropic layer formed from the liquid crystalline compound on a support body. It is preferable that a support body is transparent, and it is preferable that specifically, light transmittance is 80% or more. It is preferable that a support body has small wavelength dispersion, and it is preferable that the ratio of Re400 / Re700 is specifically less than 1.2. Especially, a polymer film is preferable. The transparent support may also serve as a first retardation region, a second retardation region, or a polarizing plate protective film. Moreover, you may comprise the 1st phase difference area or the 2nd phase difference area in the whole transparent support body and retardation layer. It is preferable that the optical anisotropy of a support body is small, It is preferable that in-plane retardation (Re) is 20 nm or less, It is more preferable that it is 10 nm or less, It is most preferable that it is 5 nm or less. In the case of serving as the first retardation region, the delay Re is 20 nm to 150 nm, more preferably 40 nm to 115 nm, and still more preferably 60 nm to 95 nm. Moreover, Nz is 1.5-7, It is more preferable that it is 2.0-5.5, It is further more preferable that it is 2.5-4.5.

Examples of the polymer film serving as the support include films of cellulose esters, polycarbonates, polysulfones, polyethersulfones, polyacrylates, and polymethacrylates. Cellulose ester films are preferred, acetyl cellulose films are more preferred, and triacetyl cellulose films are most preferred. It is preferable to form a polymer film by the solvent cast method. It is preferable that it is 20-500 micrometers, and, as for the thickness of a transparent support body, it is more preferable that it is 40-200 micrometers. In order to improve the adhesion between the transparent support and the layer (adhesive layer, alignment layer or retardation layer) formed thereon, the transparent support may be surface treated (eg, glow discharge treatment, corona discharge treatment, ultraviolet (UV) treatment, flame treatment). . You may form an adhesive layer (undercoat) on a transparent support body. In addition, in order to prevent the adhesion | attachment of the back surface and the surface after giving a slipperiness | lubricacy in a conveyance process or winding up to a transparent support body and an elongate transparent support body, the inorganic particle whose average particle size is about 10-100 nm is 5%-by solid content weight ratio. It is preferable to apply the polymer layer mixed with 40% to one side of a support body, or to use what was formed by co-flexion with a support body.

[Protective film for polarizing film]

It is preferable that the protective films for the first and second polarizing films have no absorption in the visible light region, have a light transmittance of 80% or more, and have a small delay based on birefringence. Specifically, in-plane Re is preferably 0 to 30 nm, more preferably 0 to 15 nm, and most preferably 0 to 5 nm. Moreover, it is preferable that delay Rth of a thickness direction is 0-40 nm, 0-20 nm is more preferable, It is most preferable that it is 0-10 nm. If it is a film which has this characteristic, it can use preferably, A cellulose acylate and norbornene-type film are more preferable from a durability viewpoint of a polarizing film. As a method of making Rth of a cellulose acylate film small, the method of using the compound shown below is mentioned, for example.

(Formula 19)

Moreover, the method of Unexamined-Japanese-Patent No. 11-246704, Unexamined-Japanese-Patent No. 2001-247717, etc. are mentioned as a method of making Rth of a cellulose acylate film small. Moreover, Rth can be made small also by making the thickness of a cellulose acylate film small. It is preferable that the thickness of the cellulose acylate film as a protective film for 1st and 2nd polarizing films is 10-100 micrometers, It is more preferable that it is 10-60 micrometers, It is further more preferable that it is 20-45 micrometers.

Example

The features of the present invention will be described in more detail with reference to Examples and Comparative Examples. The materials, usage amounts, ratios, treatment contents, treatment procedures, and the like shown in the following examples can be appropriately changed without departing from the gist of the present invention. Therefore, the scope of the present invention should not be limitedly interpreted by the specific example shown below.

The rod-shaped compound represented by formula (I) can be synthesize | combined according to the following synthesis example.

Synthesis Example 1

Exemplary compound (3) was synthesized by the following route. Compound (a) was synthesize | combined with reference to Unexamined-Japanese-Patent No. 2002-097170.

(Formula 20)

(a) 50 mL of tetrahydrofuran of methanesulfonyl chloride (378 mmol) and diisopropylethylamine (491 mmol) was dripped at 700 mL of (378 mmol) tetrahydrofuran solutions under ice cooling. After dripping, it heated up to room temperature and stirred for 1 hour. Then, it was ice-cooled, 150 mL of 4-hydroxybenzaldehyde (378 mmol) tetrahydrofuran solutions were added, and 50 mL of tetrahydrofuran solutions of diisopropylethylamine (491 mmol) were dripped again. After completion of the dropwise addition, a catalytic amount of N, N-dimethylaminopyridine was added, and the temperature was raised to room temperature as it was, followed by stirring for 4 hours. Ethyl acetate was added and the organic layer was washed three times with dilute hydrochloric acid. The organic layer was dried over anhydrous magnesium sulfate, the solvent was distilled off under reduced pressure, and then 640 mL of an acetonitrile solution of the obtained residue was subjected to 110 mL of an aqueous solution of sodium dihydrogen phosphate dihydrate (71.9 mmol), 35% hydrogen peroxide (57 mL), and hydrochloric acid. 270 mL of sodium (492 mmol) aqueous solution and tetrabutylammonium hydrogen sulfate (3.79 mmol) were added at room temperature, and it stirred for 1.5 hours. 900 mL of water was added, and after filtration, the residue was dissolved in ethyl acetate and dried over anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was purified by hexane to obtain (b) (84%: yield of 2 steps from (a)).

(d) (c) (70.8 mmol) and triethylamine (80.5 mmol) were dripped at 150 mL of (32.2 mmol) tetrahydrofuran solutions. After completion of the dropwise addition, a catalytic amount of N, N-dimethylaminopyridine was added, and the temperature was raised to room temperature as it was, followed by stirring for 4 hours. Ethyl acetate was added and the organic layer was washed three times with dilute hydrochloric acid. After drying the organic layer with anhydrous magnesium sulfate, the solvent was distilled off under reduced pressure to obtain (e) (82%).

(f) (e) (12 mmol) and sodium hydrogencarbonate (57.6 mmol) were added to 40 mL of (24 mmol) dimethylacetamide solutions, it heated up to 85 degreeC, and stirred for 4 hours. Ethyl acetate was added and the organic layer was washed twice with dilute hydrochloric acid. The organic layer was dried over anhydrous magnesium sulfate, the solvent was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography (eluate: methylene chloride / ethyl acetate = 3/1) to give (g) (48%). Got it.

(b) To 50 mL of (11.6 mmol) tetrahydrofuran solution, 10 mL of tetrahydrofuran solution of methanesulfonyl chloride (11.6 mmol) and diisopropylethylamine (14.6 mmol) was added dropwise under ice cooling. After dripping, it heated up to room temperature and stirred for 1.5 hours. Thereafter, the mixture was cooled with ice, 20 g of (g) (5.84 mmol) tetrahydrofuran solution was added, and 10 mL of tetrahydrofuran solution of diisopropylethylamine (14.6 mmol) was added dropwise. After completion of the dropwise addition, a catalytic amount of N, N-dimethylaminopyridine was added, and the temperature was raised to room temperature as it was, followed by stirring for 3 hours. Ethyl acetate was added and the organic layer was washed twice with dilute hydrochloric acid. The organic layer was dried over anhydrous magnesium sulfate, the solvent was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography (eluate: methylene chloride / ethyl acetate = 2/1) to give Exemplary Compound (3) (50%). )

Synthesis Example 2

Example compound (1) was synthesize | combined similarly to example compound (3) of the synthesis example 1. However, (d) was replaced with the following compound.

Formula 21

Synthesis Example 3

Example compound (6) was synthesize | combined similarly to example compound (3) of the synthesis example 1. However, (e) was replaced with the following compound.

(Formula 22)

<Production of IPS Mode Liquid Crystal Cell 1>

On one glass substrate, as shown in FIG. 1, electrodes (2 and 3 in FIG. 1) were arrange | positioned so that the distance between adjacent electrodes might be set to 20 micrometers, and the polyimide film was formed as an orientation film on it, and the rubbing process was carried out. The rubbing process was performed in the direction 4 shown in FIG. A polyimide film was formed on one surface of one glass substrate prepared separately, and the rubbing process was performed, and it was set as the orientation film. The two glass substrates are opposed to each other, and the gaps (gaps; d) of the substrates are 3.9 µm, and the rubbing directions of the two glass substrates are parallel to each other so as to be bonded to each other, and then the refractive index anisotropy (Δn) is O.0769. And a nematic liquid crystal composition having a dielectric constant anisotropy (Δε) of 4.5. The value of d · Δn of the liquid crystal layer was 300 nm.

<Preparation of 1st phase difference area 1, 1st phase difference area 2, 1st phase difference area 3>

The following composition was put into the mixing tank, stirred while heating to dissolve each component, and the cellulose acetate solution was prepared. The solution was filtered using 5 micrometers / cm <2> or less of filter papers (No.63, the product made by Adobantec) of 4 micrometers of retention particle sizes, and 35 second of filtered water hours.

Cellulose Acetate Solution Composition

Cellulose acetate with 60.9% acetylation degree

(Polymerization degree 300, Mn / Mw = 1.5) 100 parts by mass

Triphenyl phosphate (plasticizer) 7.8 parts by mass

3.9 parts by mass of biphenyldiphenyl phosphate (plasticizer)

300 parts by mass of methylene chloride (first solvent)

54 parts by mass of methanol (second solvent)

11 parts by mass of 1-butanol (third solvent)

In a separate mixing tank, 8 parts by mass of the following delay increasing agent A, 10 parts by mass of the delay increasing agent B, 0.28 parts by mass of silicon dioxide fine particles (average particle size: 0.1 µm), 80 parts by mass of methylene chloride, and 20 parts by mass of methanol The part was added and stirred while heating to prepare a delayed synergist solution (while being fine particle dispersion). 40 parts by mass of the delayed synergist solution was mixed with 474 parts by mass of the cellulose acetate solution, and sufficiently stirred to prepare dope.

(Formula 23)

Delayed synergist A

(Formula 24)

Delayed synergist B

The obtained dope was cast using a band softener. A film with 15% by mass of residual solvent was transversely stretched at a stretching ratio of 20% using a tenter under a condition of 130 ° C, held at 50 ° C for 30 seconds with the width after stretching, and then the clip was removed to prepare a cellulose acetate film. It was. The amount of residual solvent at the time of completion | finish of extending | stretching was 5 mass%, It further dried, and made the film into the amount of residual solvent less than 0.1 mass%.

The thickness of the film (1st phase difference area | region 1) obtained in this way was 80 micrometers. Regarding the produced first retardation region 1, the light incident angle dependence of Re was measured using an automatic birefringence meter (KOBRA-21ADH, manufactured by Oji Measurement Instruments Co., Ltd.), so that Re was 70 nm and Rth was 175. It is nm and it turns out that Nz is 3.0 from this.

In a separate mixing tank, 16 parts by mass of the above-mentioned delay increasing agent A, 8 parts by mass of the delay increasing agent B, 0.28 parts by mass of silicon dioxide fine particles (average particle size: 0.1 µm), 80 parts by mass of methylene chloride, and 20 parts by mass of methanol It injected | thrown-in, it stirred while heating, and prepared the delay raising agent solution (while being microparticle dispersion liquid). 45 parts by mass of the delayed synergist solution was mixed with 474 parts by mass of the cellulose acetate solution, and stirred sufficiently to prepare a dope, and then a film was formed in the same manner as in the first phase difference region 1 described above. The thickness of the film (1st phase difference area | region 2) obtained in this way was 80 micrometers. Regarding the produced first phase difference region 2, by measuring the light incident angle dependency of Re using an automatic birefringence meter (KOBRA-21ADH, manufactured by Oji Measurement Instruments Co., Ltd.), Re was 60 nm and Rth was 210. It is nm and it turned out that Nz is 4.0 from this.

18 mass parts of said delay increasing agent A, 0.28 mass parts of silicon dioxide microparticles (average particle size: 0.1 micrometer), 80 mass parts of methylene chlorides, and 20 mass parts of methanol are thrown into another mixing tank, and it stirs, heating, and delays A synergist solution (while being a particulate dispersion) was prepared. 25 parts by mass of the delayed synergist solution was mixed with 474 parts by mass of the cellulose acetate solution, and stirred sufficiently to prepare a dope, and then a film was formed in the same manner as in the first phase difference region 1 described above except that the draw ratio was 23%. The thickness of the film (1st phase difference area | region 3) obtained in this way was 80 micrometers. Regarding the produced first phase difference region 3, by measuring the light incident angle dependence of Re using an automatic birefringence meter (KOBRA-21ADH, manufactured by Oji Measurement Instruments Co., Ltd.), Re was 35 nm and Rth was 135. It is nm and it turns out that Nz is 4.4 from this.

<Preparation of 2nd phase difference area 1, 2nd phase difference area 2, 2nd phase difference area 3, 2nd phase difference area 4, 2nd phase difference area 5, 2nd phase difference area 6>

The surface of each of the produced 1st phase difference area | region 1, the 1st phase difference area | region 2, and the 1st phase difference area | region 3 was saponified, and 20 ml / m <2> of oriented-film coating liquids of the following compositions were apply | coated on this film with the wire bar coater. It dried for 60 second by the warm air of 60 degreeC, and 120 second by the warm air of 100 degreeC again, and formed the film | membrane. Next, the rubbing process was performed to the formed film in the direction parallel to the slow axis direction of a film, and the oriented film was obtained.

Composition of alignment film coating liquid

10 parts by mass of the following modified polyvinyl alcohol

371 parts by mass of water

119 parts by mass of methanol

Glutalaldehyde 0.5 parts by mass

(Formula 25)

Modified polyvinyl alcohol

Next, 3.8 g of a rod-shaped liquid crystal compound (example compound 1, 3 or 6), 0.06 g of a photoinitiator (Irugacure 907, Chiba Chemical Co., Ltd. make), a sensitizer (Kayacure DETX, Nippon Kayaku Co., Ltd. product) 0.02 g, 0.076 g of the following onium salt (vertical alignment accelerator on the alignment film interface side) (but no phase difference of 60,000 onium salt is added), and 0.002 g or 9.2 of any one of the following air interface-side vertical alignment agents α and β A solution (2-1 to 2-6) dissolved in g methyl ethyl ketone was prepared.

This solution was apply | coated to the orientation film side of the film in which the said orientation film was formed with the wire bar of the number of times shown in the following table, respectively. This was attached to a metal frame and heated for 2 minutes in a 100 degreeC thermostat, and the rod-shaped liquid crystal compound was orientated. Subsequently, UV irradiation was performed at 120 ° C. with a 120 W / cm 2 high pressure mercury lamp for 20 seconds to crosslink the rod-like liquid crystal compound, and thereafter, allowed to cool to room temperature to prepare a phase difference layer.

Formula 26

Onium salt (vertical alignment promoter on the alignment film interface side)

(Formula 27)

Vertical Orientation Accelerator on Air Interface Side

Second phase difference region number Liquid crystal composition number Liquid crystalline compound Air interfacial alignment agent Second phase difference region 1 Second phase difference region 2 Second phase difference region 3 Second phase difference region 4 Second phase difference region 5 Second phase difference region 6 2-1 2-2 2-3 2-4 2-5 2-6 Exemplary Compound 3 Exemplary Compound 6 Exemplary Compound 1 Exemplary Compound 3 Exemplary Compound 3 Exemplary Compound 3 α α β none β β (no onium salt added)

Film number Phase difference layer 2nd phase difference name which consists of a bar liquid crystal Name of support first retardation region Wire bar count Phase difference 1 Phase difference 2 Phase difference 3 Phase difference 4 Phase difference 5 Phase difference 6 Second phase difference region 1 Second phase difference region 2 Second phase difference region 3 Second phase difference region 4 Second phase difference region 5 Second phase difference region 6 First phase difference region 1 First phase difference region 1 First phase difference region 2 First phase difference region 1 First phase difference region 3 First phase difference region 3 # 4.5 # 3.6 # 6.0 # 3.4 # 6.0 # 6.0

The light incident angle dependence of Re of a film produced using an automatic birefringence meter (KOBRA-21ADH, manufactured by Oji Measurement Instruments Co., Ltd.) was measured, and only the second phase difference region was determined by subtracting the contribution of the previously measured support. As a result of calculating the optical characteristics of the second retardation region 1, Re is 0 nm, Rth is -225 nm, the second retardation region 2 is Re 0 nm, Rth is -180 nm, and the second retardation region 3 is Re 0 nm, Rth is -295 nm, the second retardation region 4 is Re at 0 nm, Rth is -170 nm, the second retardation region 5 is Re at 0 nm, Rth is -292 nm, and the second retardation region 6 is It was confirmed that Re is 0 nm and Rth is -290 nm, and the rod-shaped liquid crystals are aligned substantially vertically in all.

<Production of Polarizing Plate Protective Film 1>

The following composition was put into the mixing tank, it stirred while heating, and each component was dissolved and the cellulose acetate solution A was prepared.

<Cellulose Acetate Solution A Composition>

100 parts by mass of cellulose acetate having a degree of substitution of 2.86

Triphenyl phosphate (plasticizer) 7.8 parts by mass

3.9 parts by mass of biphenyldiphenyl phosphate (plasticizer)

300 parts by mass of methylene chloride (first solvent)

54 parts by mass of methanol (second solvent)

11 parts by mass of 1-butanol

The following composition was thrown into another mixing tank, it stirred while heating, each component was melt | dissolved, and the additive solution B-1 was prepared.

<Additive solution B-1 composition>

80 parts by mass of methylene chloride

20 parts by mass of methanol

40 parts by mass of optically anisotropic reducing agent

Formula 28

40 mass parts of additive solution B-1 was added to 477 mass parts of cellulose acetate solution A, and it fully stirred, and dope was prepared. The dope was cast on a drum cooled to 0 ° C. from oil studies. It peels out of the field of 70 mass% of solvent content rates, and fixes the width direction both ends of a film with a pin tenter (pin tenter as described in FIG. 3 of Unexamined-Japanese-Patent No. 4-1009), and the solvent content rate is 3-5 mass%. The furnace was dried while maintaining the interval at which the elongation in the transverse direction (direction perpendicular to the machine direction) became 3%. Then, it dried further by conveying between the rolls of a heat processing apparatus, and produced the polarizing plate protective film 1 of thickness 80micrometer.

The optical incidence angle dependence of Re was measured using an automatic birefringence meter (KOBRA-21ADH, manufactured by Oji Measurement Instruments Co., Ltd.), and the optical properties were calculated. I could confirm it.

<Production of Polarizing Plate A>

Next, iodine was adsorbed to the stretched polyvinyl alcohol film to produce a polarizing film, and saponified to a commercially available cellulose acetate film (Fujitak TD80UF, manufactured by Fuji Photo Film Co., Ltd., Re = 3 nm, Rth = 45 nm). Thereafter, the polyvinyl alcohol-based adhesive was used to adhere to one side of the polarizing film to form a polarizing plate A.

<Production of Polarizing Plate B>

Iodine is adsorbed on the stretched polyvinyl alcohol film to produce a polarizing film, and after saponification to a commercially available cellulose acetate film (Fujitak TD80UF, manufactured by Fuji Photo Film Co., Ltd.), a polyvinyl alcohol-based adhesive is used to form a polarizing film. It adhere | attached on both sides and formed the polarizing plate B.

<Production of Polarizing Plate C>

The polarizing film was produced by the same method, and was saponified to the commercially available cellulose acetate film (Fujitak TD80UF, manufactured by Fuji Photo Film Co., Ltd.), and then adhered to one side of the polarizing film using a polyvinyl alcohol-based adhesive. Moreover, the polarizing plate protective film 1 produced above was affixed to another surface of the polarizing film by the same method, and the polarizing plate C was formed.

<Production of Polarizing Plate D>

The polarizing film was produced by the same method, and was saponified to the commercially available cellulose acetate film (Fujitak TD80UF, manufactured by Fuji Photo Film Co., Ltd.), and then adhered to one side of the polarizing film using a polyvinyl alcohol-based adhesive. In addition, after saponification treatment to a commercially available cellulose acetate film (Fujitak T40UZ, manufactured by Fuji Photo Film Co., Ltd., Re = 1 nm, Rth = 35 nm), another polarizing film was used using a polyvinyl alcohol-based adhesive. It adhere | attached on one side and the polarizing plate D was formed.

Example 1

Polarizing polarizing film 1 produced using polyvinyl alcohol-type adhesive for polarizing plate A so that the 1st phase difference area 1 side may become a polarizing film side, and the transmission axis of a polarizing film and the slow axis of 1st phase difference area 1 may become parallel. The polarizing plate 1 was formed by adhering to the side to which the cellulose acetate film of the film | membrane was not affixed.

The slow axis of the first retardation region 1 is parallel to the rubbing direction of the liquid crystal cell in one of the IPS mode liquid crystal cells 1 produced as described above (that is, the slow axis of the first retardation region 1 is the liquid crystal at the time of black display). The polarizing plate 1 was attached so that the 2nd phase difference area | region 1 surface side may become a liquid crystal cell side so that it may become parallel to the slow axis of the liquid crystal molecule of a cell.

Subsequently, the polarizing plate C was attached to the other side of this IPS mode liquid crystal cell 1 so that the polarizing plate protective film 1 side became the liquid crystal cell side, and the polarizing plate 1 was arranged so that cross nicol arrangement was possible, and the liquid crystal display device was produced. It was. The leakage light of the liquid crystal display device produced in this way was measured. The leakage light when observed in the left oblique direction of 60 ° was 0.035%.

Example 2

Using the polyvinyl alcohol-based adhesive for the polarizing plate A, the produced film retardation 2 is such that the first retardation region 1 side is on the polarizing film side, and the transmission axis of the polarizing film and the slow axis of the first retardation region 1 are parallel to each other. It adhere | attached on the side which the cellulose acetate film of a polarizing film is not affixed, and the polarizing plate 2 was formed.

In the IPS mode liquid crystal cell 1 produced above, the slow axis of the first retardation region 1 is parallel to the rubbing direction of the liquid crystal cell (that is, the slow axis of the first retardation region 1 is the liquid crystal at the time of black display). The polarizing plate 2 was attached so that it might become parallel to the slow axis of the liquid crystal molecule of a cell), and the 2nd phase difference area 2 surface side might be a liquid crystal cell side.

Subsequently, the polarizing plate D was attached to the other one side of this IPS mode liquid crystal cell 1 so that the T40UZ side might be the liquid crystal cell side, and the polarizing plate 2 was arrange | positioned so that cross nicol was produced, and the liquid crystal display device was produced. The leakage light of the liquid crystal display device produced in this way was measured. The leakage light when observed in the left oblique direction of 60 ° was 0.045%.

Example 3

The polarizing plate 3 is attached to the polarizing plate B using an acrylic resin adhesive so that the film retardation 3 is on the polarizing film side of the second retardation region 3 and the transmission axis of the polarizing film and the slow axis of the first retardation region 2 are perpendicular to each other. Formed.

In the IPS mode liquid crystal cell 1 produced above, the slow axis of the first retardation region 2 is orthogonal to the rubbing direction of the liquid crystal cell (that is, the slow axis of the first retardation region 2 is the liquid crystal at the time of black display). The polarizing plate 3 was affixed so that 1st phase difference area | region 2 surface side may become a liquid crystal cell side so that it may orthogonally cross the slow axis of the liquid crystal molecule of a cell.

Subsequently, the polarizing plate C was attached to the other side of this IPS mode liquid crystal cell 1 so that the polarizing plate protective film 1 side might be the liquid crystal cell side, and the polarizing plate 3 was arrange | positioned so that cross nicol might be produced, and the liquid crystal display device was produced. The leakage light of the liquid crystal display device produced in this way was measured. The leakage light when observed in the left oblique direction of 60 ° was 0.055%.

Example 4

The film retardation 4 is attached to the polarizing plate C on the polarizing plate protective film 1 side using an acrylic resin adhesive so that the second retardation region 4 side becomes the polarizing film side and the transmission axis of the polarizing film and the slow axis of the first retardation region 1 are perpendicular to each other. To form the polarizing plate 4.

In the IPS mode liquid crystal cell 1 produced above, the slow axis of the first retardation region 1 is orthogonal to the rubbing direction of the liquid crystal cell (that is, the slow axis of the first retardation region 1 is the liquid crystal at the time of black display). The polarizing plate 4 was affixed so that the 1st retardation area | region 1 surface side might become a liquid crystal cell side so that it may orthogonally cross the slow axis of the liquid crystal molecule of a cell.

Subsequently, the polarizing plate B was affixed on the other side of this IPS mode liquid crystal cell 1 so that cross nicol might be arrange | positioned with the polarizing plate 4, and the liquid crystal display device was produced. The leakage light of the liquid crystal display device produced in this way was measured. The leakage light when observed in the left oblique direction of 60 ° was 0.075%.

Comparative Example 1

Instead of the exemplary compound 3 used in the preparation of the second phase difference region 1, the liquid crystal mixture (X) described in JP 2000-514202 was used and evaluated in the same manner as in [Example 1]. As a result, the leakage light when observed in the left oblique direction of 60 ° was 0.10%.

(Formula 29)

Liquid Crystal Mixture (X)

((A) / (B) = 69/19 weight ratio)

Comparative Example 2

A commercially available polarizing plate (HLC2-5618, manufactured by Sanlitz Co., Ltd.) was attached to both sides of the produced IPS mode liquid crystal cell 1 in a batch of cross nicol to prepare a liquid crystal display device. No optical compensation film was used. In the said liquid crystal display device, the polarizing plate was affixed similarly to Example 1 so that the transmission axis of an upper polarizing plate might become in parallel with the rubbing direction of a liquid crystal cell. The leakage light of the liquid crystal display device produced in this way was measured. The leakage light when observed in the left oblique direction of 60 ° was 0.55%.

Comparative Example 3

Using the polyvinyl alcohol-based adhesive to the polarizing plate A, the produced film retardation 1 of the polarizing film so that the first retardation region 1 side is the polarizing film side, but the transmission axis of the polarizing film and the slow axis of the first retardation region 1 orthogonal to each other. It adhere | attached on the side which is not stuck a cellulose acetate film, and formed the polarizing plate 5.

The slow axis of the first retardation region 1 is orthogonal to the rubbing direction of the liquid crystal cell (that is, the slow axis of the first retardation region 1 is the liquid crystal at the time of black display) in one of the IPS mode liquid crystal cells 1 produced above. The polarizing plate 5 was attached so that the second phase difference area | region 1 surface side may become a liquid crystal cell side so that it may orthogonally cross the slow axis of the liquid crystal molecule of a cell.

Subsequently, the polarizing plate A was attached to the other side of this IPS mode liquid crystal cell 1 so that the polarizing plate protective film 1 side became the liquid crystal cell side, and the polarizing plate 5 was arrange | positioned so that cross nicol might be arrange | positioned, and the liquid crystal display device was produced. The leakage light of the liquid crystal display device produced in this way was measured. The leakage light when observed in the left oblique direction of 60 ° was 1.75%, which was very large.

[Comparative Example 4]

The film retardation 3 is attached to the polarizing plate B using an acrylic resin adhesive so that the second retardation region 3 side is on the polarizing film side, but the transmission axis of the polarizing film and the slow axis of the first retardation region 2 are parallel to each other. Formed.

The slow axis of the first retardation region 2 is parallel to the rubbing direction of the liquid crystal cell (that is, the slow axis of the first retardation region 2 is the liquid crystal at the time of black display) in one of the IPS mode liquid crystal cells 1 produced above. The polarizing plate 6 was attached so that the 1st phase difference area 2 surface side may become a liquid crystal cell side so that it may become parallel to the slow axis of the liquid crystal molecule of a cell.

Subsequently, the polarizing plate A was attached to the other side of this IPS mode liquid crystal cell 1 so that the polarizing plate protective film 1 side might become the liquid crystal cell side, and the polarizing plate 6 was arrange | positioned so that cross nicol might be arrange | positioned, and the liquid crystal display device was produced. The leakage light of the liquid crystal display device produced in this way was measured. The leakage light when observed in the left oblique direction of 60 ° was 2.04%, which was very large.

In the present invention, by using a rod-shaped compound having a specific structure, it is possible to provide an optically anisotropic film having optical anisotropy expressed by a smectic phase, which can be produced by a simple method without requiring a special vertical alignment film. The optically anisotropic film of this invention contributes to the improvement of the display characteristic of a liquid crystal display device, especially the liquid crystal display device of IPS mode. For example, a liquid crystal cell including at least a first polarizing film, a first retardation region, a second retardation region, and a liquid crystal layer made of a liquid crystal material between a pair of substrates, the nematic at the time of black display A liquid crystal display device in which liquid crystal molecules of a liquid crystal material are oriented substantially parallel to the surfaces of the pair of substrates, wherein the delay Re of the first retardation region is 20 nm to 150 nm, and the value Nz of the first retardation region is 1.5. -7, the delay Re of the second retardation region is substantially 0 nm, the delay Rth of the second retardation region is -80 nm to -400 nm, and the transmission axis of the first polarizing film is of the liquid crystal molecules at the time of black display. When used in the second phase difference region (which may be part of it) of the liquid crystal display device configured in parallel with the slow axis direction, two pieces of polarized light when viewed from the inclined azimuth direction without changing any characteristic in the front direction The fall of contrast resulting from the shift | deviation of the absorption axis of a board from 90 degree, especially the fall of contrast in the 45 degree inclination direction can be improved. And improvement of contrast can be implement | achieved further by making Rth of the protective film of a polarizing film into 40 nm or less.

Claims (11)

An optically anisotropic film containing the rod-shaped compound represented by the following general formula (I).  (Formula 1)

[Wherein, P ¹ and P ² are each independently a polymerizable group or a hydrogen atom; X ^{1 to} X ³ are each independently an alkylene group or a substituted alkylene group; L ¹ and L ⁶ are each independently a single bond, —O—CO—O—, —O—, —CO—O—, or —O—CO—; L ² and L ⁵ are each independently a single bond, —CO—O—, —O—CO—, —C≡C— or —CH═CH—; L ³ and L ⁴ are each independently —O—CO—O—, —CO—O—, —O—, —O—CO—, —C≡C— or —CH═CH—; Y ^1- Y ⁴ Are each independently a halogen atom, cyano group, alkyl group, alkenyl group or alkoxy group; n1 to n4 are each independently 0 to 4; s and t are each independently 0-5, and the sum of s and t is 1 or more] The method of claim 1, An optically anisotropic film in which the rod-shaped compound represented by the general formula (I) is fixed in a smectic shape. The method according to claim 1 or 2, The optically anisotropic film in which the crosslinked material of the compound represented by said Formula (I) is being fixed in the state orthogonally oriented. The method according to any one of claims 1 to 3, The optically anisotropic film containing the additive which promotes the vertical orientation in the air interface of the compound represented by said Formula (I). The method according to any one of claims 1 to 4, The optically anisotropic film containing the additive which promotes the vertical alignment in the orientation film interface of the compound represented by said Formula (I). At least a liquid crystal cell in which a first polarizing film, a first retardation region, a second retardation region, and a liquid crystal layer are sandwiched between a pair of substrates, wherein the liquid crystal molecules on the black display surface of the pair of substrates A liquid crystal display device oriented substantially parallel with respect to  The delay Re of the first retardation region is 20 nm to 150 nm, the value Nz of the first retardation region is 1.5 to 7, the delay Re of the second retardation region is substantially 0 nm, and the delay Rth of the second retardation region is -80 nm--400 nm, The crosslinked product of the compound represented by the formula (I) contained in the optically anisotropic film according to any one of claims 1 to 5, wherein the second retardation region comprises the optically anisotropic film, is oriented substantially vertically. Is fixed in the state, The liquid crystal display device in which the transmission axis of a 1st polarizing film is parallel to the slow-axis direction of the liquid crystal molecule at the time of black display. The method of claim 6, The first polarizing film, the first retardation region, the second retardation region, and the liquid crystal cell are arranged in this order, And a slow axis of the first retardation region is substantially parallel to a transmission axis of the first polarizing film. The method of claim 7. The first polarizing film, the second retardation region, the first retardation region, and the liquid crystal cell are arranged in this order, And a slow axis of the first retardation region is substantially orthogonal to the transmission axis of the first polarizing film. The method according to any one of claims 6 to 8, Further provided with a second polarizing film having a transmission axis orthogonal to the transmission axis of the first polarizing film, A liquid crystal display device wherein the first polarizing film and the second polarizing film are disposed with the first retardation region, the second retardation region, and the liquid crystal cell interposed therebetween. The method according to any one of claims 6 to 9, Liquid crystal display which has a pair of protective film arrange | positioned between the said 1st polarizing film and / or a 2nd polarizing film, and the phase difference Rth of the thickness direction of the side protective film close to a liquid crystal layer among the pair of protective films is 40 nm or less. Device. The method according to any one of claims 6 to 10, Liquid crystal which has a pair of protective film arrange | positioned between the said 1st polarizing film and / or a 2nd polarizing film, and the side protective film which is close to a liquid crystal layer among the pair of protective films is a cellulose acylate film or a norbornene-type film. Display device.

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