JP2006215093A - Retardation film and liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a retardation film made by vertically aligning molecules of a rod-like liquid crystalline compound uniformly without defects. <P>SOLUTION: The retardation film has an alignment film comprising at least one kind of polymer and an optical anisotropic layer comprising a liquid crystal composition which includes at least one kind of rod-like liquid crystalline compound and at least one kind of boronic acid compound. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a retardation film and a liquid crystal display device, and in particular, can be suitably used for an in-plane switching mode liquid crystal display device that performs display by applying a horizontal electric field to horizontally aligned liquid crystal molecules. The present invention relates to a retardation film and a liquid crystal display device using the same.

  As a liquid crystal display device, a so-called TN mode is widely used in which a liquid crystal layer in which nematic liquid crystal is twisted is sandwiched between two orthogonal polarizing plates and an electric field is applied in a direction perpendicular to the substrate. In this method, since liquid crystal molecules rise with respect to the substrate during black display (liquid crystal molecules are aligned perpendicular to the substrate), birefringence due to the liquid crystal molecules occurs when viewed from an oblique direction, and light leakage occurs. In order to solve this problem, a system in which a liquid crystal cell is optically compensated by using a film in which liquid crystal molecules are hybrid-aligned and this light leakage is prevented has been put into practical use. However, even if liquid crystal molecules are used, it is very difficult to completely optically compensate the liquid crystal cell without any problem, resulting in a problem that gradation reversal in the lower direction of the screen cannot be suppressed.

  In order to solve such a problem, a liquid crystal display device using a so-called in-plane switching (IPS) mode in which a lateral electric field is applied to the liquid crystal, or a liquid crystal having a negative dielectric anisotropy is vertically aligned and formed in the panel. A vertical alignment (VA) mode in which alignment is divided by protrusions and slit electrodes has been proposed and put into practical use. In recent years, these panels have been developed not only for monitor applications but also for TV applications, and screen brightness has been greatly improved accordingly. For this reason, a slight light leakage in the diagonally oblique incident direction during black display, which has not been considered as a problem in these operation modes, has become apparent as a cause of a decrease in display quality.

As one means for improving the color tone and the viewing angle of black display, the arrangement of an optical compensation material having birefringence characteristics between the liquid crystal layer and the polarizing plate is also studied in the IPS mode.
For example, by arranging a birefringent medium with optical axes orthogonal to each other to compensate for increase / decrease in retardation of the liquid crystal layer during tilting, the white display or halftone display is obliquely arranged between the substrate and the polarizing plate. It is disclosed that coloring can be improved when viewing directly from (see, for example, Patent Document 1). In addition, a method using an optical compensation film made of a styrenic polymer having a negative intrinsic birefringence or a discotic liquid crystalline compound (see, for example, Patent Documents 2 to 4), or a birefringence is positive and an optical axis as an optical compensation film. Is a method of combining a film in the plane of a film with a film having a positive birefringence and an optical axis in the normal direction of the film (see, for example, Patent Document 5). A method of using an optical compensation sheet (for example, see Patent Document 6), a method of using a film having a negative retardation as a protective film of a polarizing plate, and providing an optical compensation layer having a positive retardation on this surface (for example, Patent Document 7) has been proposed.

  On the other hand, a method of achieving optical compensation of IPS by combining a retardation film having a positive birefringence and an optical axis in the normal direction has been studied. In order to realize such a retardation film, a liquid crystal material is used. There is known a method of vertically aligning and fixing the alignment state (see, for example, Patent Documents 8 to 10).

  As a method for vertically aligning the rod-like liquid crystalline compound, a method using a vertical alignment film as the alignment film, or a vertical alignment agent (for example, a quaternary ammonium-substituted silane coupling agent) is formed on the substrate. In addition, a method for forming a layer of a liquid crystal compound has been proposed (for example, Non-Patent Documents 1 and 2). However, in recent years, demands for display characteristics of monitors have become stricter, and anisotropic materials fixed by a conventionally known vertical alignment method do not have sufficient micro-uniformity, and improvements have been demanded. In addition, using a special alignment film or the like is not suitable for manufacturing on an industrial level.

Japanese Patent Laid-Open No. 9-80424 Japanese Patent Laid-Open No. 10-54982 JP-A-11-202323 Japanese Patent Laid-Open No. 9-292522 JP 11-133408 A JP-A-11-305217 JP-A-10-307291 Special Table 2000-514202 Japanese Patent Laid-Open No. 10-319408 JP-A-6-331826 Mitsuharu Okano et al., “Liquid Crystal”, Application, Bafukan, 1985, 61 pages Shohei Naemura, Appl. Phys. Lett. 33, No. 1, 1978, 1-3

  An object of the present invention is to provide a retardation film in which molecules of a rod-like liquid crystal compound are vertically aligned uniformly without defects, and with a simple configuration, not only display quality but also a viewing angle is remarkably improved. An object of the present invention is to provide a liquid crystal display device (particularly an IPS liquid crystal display device).

The above problems have been achieved by the following means.
<1> A retardation film having an alignment film made of at least one polymer and an optically anisotropic layer made of a liquid crystal composition containing at least one rod-like liquid crystalline compound and at least one boronic acid compound.
<2> The retardation film according to <1>, wherein the boronic acid compound is represented by the following general formula (I).

（一般式（Ｉ）中、Ｒ¹およびＲ²はそれぞれ独立に、水素原子、置換もしくは無置換の、脂肪族炭化水素基、アリール基、またはヘテロ環基を表し、これらは互いに連結して環を形成してもよい。また、Ｒ³は置換もしくは無置換の、脂肪族炭化水素基、アリール基またはヘテロ環基を表す。）
＜３＞ 前記ボロン化合物が架橋性基で置換されている＜１＞または＜２＞の位相差膜。

(In the general formula (I), R ¹ and R ² each independently represents a hydrogen atom, a substituted or unsubstituted aliphatic hydrocarbon group, an aryl group, or a heterocyclic group, which are linked together to form a ring. And R ³ represents a substituted or unsubstituted aliphatic hydrocarbon group, aryl group or heterocyclic group.)
<3> The retardation film according to <1> or <2>, wherein the boron compound is substituted with a crosslinkable group.

<4> The retardation film according to any one of <1> to <3>, wherein the rod-like liquid crystalline compound is aligned substantially perpendicularly to the film surface of the retardation film.
<5> The retardation film according to any one of <1> to <4>, wherein the alignment film is made of a polyvinyl alcohol derivative.
<6> At least a first polarizing film, a first retardation film, a second retardation film, and a liquid crystal cell in which a liquid crystal layer containing liquid crystal molecules is sandwiched between a pair of substrates, and the liquid crystal molecules during black display Is a liquid crystal display device which is aligned substantially parallel to the surfaces of the pair of substrates, wherein the in-plane retardation (Re) of the first retardation film is 20 nm to 150 nm and Nz is 1.5 to 7, the in-plane refractive index of the second retardation film is substantially equal, the retardation (Rth) in the thickness direction is -80 nm to -400 nm, and the second retardation film is <1> to <5>, wherein the transmission axis of the first polarizing film is parallel to the slow axis direction of the liquid crystal molecules during black display.

  According to the present invention, it is possible to provide a retardation film in which a liquid crystal compound used for an optically anisotropic layer is uniformly vertically aligned without defects. Furthermore, according to the present invention, it is possible to provide a liquid crystal display device with a simple structure and with not only display quality but also a significantly improved viewing angle.

BEST MODE FOR CARRYING OUT THE INVENTION

  Hereinafter, an embodiment of the liquid crystal display device of the present invention and its constituent members will be described in order. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

  In the retardation film of the present invention, an alignment film made of at least one polymer and an optically anisotropic layer made of a liquid crystal composition containing at least one rod-like liquid crystalline compound and at least one boronic acid compound are arranged in this order. It is provided. According to the retardation film of the present invention, the molecules of the rod-like liquid crystal compound can be uniformly vertically aligned without defects.

  In addition, the liquid crystal display device of the present invention is a liquid crystal in which at least a first polarizing film, a first retardation film, a second retardation film, and a liquid crystal layer made of a liquid crystal material containing liquid crystal molecules are sandwiched between a pair of substrates. A liquid crystal display device in which the liquid crystal molecules are aligned substantially parallel to the surfaces of the pair of substrates during black display, and the in-plane retardation (Re ) Is 20 nm to 150 nm, the Nz value is 1.5 to 7, the in-plane refractive index of the second retardation film is substantially equal, and the thickness direction retardation (Rth) is −80 nm to − The transmission axis of the first polarizing film is 400 nm and is parallel to the slow axis direction of the liquid crystal molecules during black display.

  The liquid crystal display device of the present invention does not change the characteristics in the front direction, and the contrast decreases when the absorption axes of the two polarizing plates deviate from 90 ° when viewed from an oblique azimuth direction, in particular, A reduction in contrast from an oblique direction of 45 ° can be improved. Furthermore, the contrast can be further improved by setting the Rth of the protective film in the polarizing film to 40 nm or less. Further, by using the retardation film of the present invention as the second retardation film, the second retardation film can be easily produced without using a special vertical alignment film.

In the present specification, the retardation value in the in-plane direction (Re; hereinafter simply referred to as “Re”) and the retardation value in the film thickness direction (Rth; hereinafter referred to simply as “Rth”). .) Is calculated based on the following.
Re (λ) and Rth (λ) respectively represent in-plane direction retardation and thickness direction retardation at wavelength λ.
The Re (λ) is measured by making light having a wavelength of λ nm incident in the normal direction of the film in “KOBRA 21ADH” (manufactured by Oji Scientific Instruments). Rth (λ) is a wavelength of λ nm from the direction inclined by + 40 ° with respect to the normal direction of the film, with Re (λ) and the slow axis (determined by KOBRA 21ADH) as the tilt axis (rotation axis). Retardation value measured by incidence of light and retardation value measured by incidence of light having a wavelength of λ nm from a direction inclined by -40 ° with respect to the film normal direction with the in-plane slow axis as the tilt axis Based on the retardation values measured in a total of three directions, the above-mentioned “KOBRA 21ADH” can be used. At this time, it is necessary to input an assumed value of average refractive index and a film thickness. “KOBRA 21ADH” can calculate nx, ny, and nz in addition to Rth (λ). Here, nx is the refractive index in the slow axis (x) direction in the film plane, ny is the refractive index in the fast axis (y) direction in the film plane, and nz is the film thickness direction (film Refractive index in the direction perpendicular to the surface.

  As for the above “average refractive index”, 1.48 is used for cellulose acetate, but values of polymer films for typical optical applications other than cellulose acetate include cycloolefin polymer (1.52), polycarbonate (1.59). ), Polymethyl methacrylate (1.49), polystyrene (1.59), and the like. As the average refractive index value of other existing polymer materials, a polymer handbook (John Wiley & Sons, Inc.) or a catalog value of a polymer film can be used. In addition, in the case of a material whose average refractive index is unknown, it can be measured using an Abbe refractometer. Further, Nz = (nx−nz) / (nx−ny) is further calculated from the calculated nx, ny, and nz.

  Further, in the present specification, “parallel” and “orthogonal” mean that the angle is within a range of strictly less than ± 10 °. In this range, an error from a strict angle is preferably less than ± 5 °, and more preferably less than ± 2 °. Further, “substantially vertical” means within a range of less than ± 20 ° from a strict vertical angle. In this range, an error from a strict angle is preferably less than ± 15 °, and more preferably less than ± 10 °. The “slow axis direction” means a direction in which the refractive index is maximized. Further, the measurement wavelength of the refractive index is a value at λ = 550 nm in the visible light region unless otherwise specified.

  In this specification, unless otherwise specified, the term “polarizing plate” is cut into a size to be incorporated into a long polarizing plate and a liquid crystal device (in this specification, “cutting” includes “punching” and “cutting out”. It is used in the meaning including both of the polarizing plates. In this specification, “polarizing film” and “polarizing plate” are distinguished from each other, but “polarizing plate” means a laminate having a transparent protective film for protecting the polarizing film on at least one surface of the “polarizing film”. It shall be.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram showing an example of a pixel region of the liquid crystal display device of the present invention. 2 and 3 are schematic views of an embodiment of the liquid crystal display device of the present invention. The scope of the liquid crystal display device of the present invention is not limited by these drawings.

<Liquid crystal display device>
[Configuration of liquid crystal display device]
The liquid crystal display device shown in FIG. 2 has polarizing films 8 and 20, a first retardation film 10, a second retardation film 12, substrates 13 and 17, and a liquid crystal layer 15 sandwiched between the substrates. . The polarizing films 8 and 20 are sandwiched between the protective films 7a and 7b and 19a and 19b, respectively.

  In the liquid crystal display device of FIG. 2, the liquid crystal cell includes substrates 13 and 17 and a liquid crystal layer 15 sandwiched between them. The product Δn · d of the thickness d (μm) of the liquid crystal layer and the refractive index anisotropy Δn is optimal in the range of 0.2 to 0.4 μm for the IPS type having no twisted structure in the transmission mode. In this range, the white display luminance is high and the black display luminance is small, so that a bright and high-contrast display device can be obtained. An alignment film (not shown in FIG. 2) is formed on the surfaces of the substrates 13 and 17 that are in contact with the liquid crystal layer 15, and the liquid crystal molecules are aligned substantially parallel to the surface of the substrate and applied to the alignment film. The orientation direction of the liquid crystal molecules in the no-voltage application state or the low application state is controlled by the rubbing treatment direction (arrows 14 and 18). Further, an electrode (not shown in FIG. 2) capable of applying a voltage to the liquid crystal molecules is formed on the inner surface of the substrate 13 or 17.

  FIG. 1 schematically shows the orientation of liquid crystal molecules in one pixel region (liquid crystal element pixel region 1) of the liquid crystal layer. In FIG. 1, the orientation of the liquid crystal molecules in a region of an extremely small area corresponding to one pixel of the liquid crystal layer 14 is determined by the rubbing direction 4 of the alignment film formed on the inner surfaces of the substrates 13 and 17, and the substrate 13 and 17 are shown together with electrodes 2 and 3 capable of applying a voltage to liquid crystal molecules formed on the inner surface of 17. In addition, when active driving is performed using a nematic liquid crystal having positive dielectric anisotropy as a field effect type liquid crystal, the liquid crystal molecule alignment direction in a no-voltage applied state or a low applied state is that of the liquid crystal molecules 5a and 5b. Thus, the direction is substantially parallel to the substrate, and black display is obtained at this time. When a voltage is applied between the electrodes 2 and 3, the liquid crystal molecules are aligned in a direction like the liquid crystal molecules 6a and 6b according to the voltage. Usually, bright display is performed in this state.

In FIG. 2 again, the transmission axis 9 of the polarizing film 8 and the transmission axis 21 of the polarizing film 20 are arranged orthogonally. The slow axis 11 of the first retardation film 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 during black display.
In the liquid crystal display device shown in FIG. 2, the configuration in which the polarizing film 8 is sandwiched between the two protective films 7a and 7b is shown, but the protective film 7b has an arbitrary configuration and may not be provided. The polarizing film 20 is also sandwiched between the two protective films 19a and 19b, but the protective film 19a on the side close to the liquid crystal layer 15 may not be provided. In the embodiment of FIG. 2, the first retardation film and the second retardation film may be disposed between the liquid crystal cell and the viewing-side polarizing film with reference to the position of the liquid crystal cell. You may arrange | position between the liquid crystal cell and the polarizing film of the back side. In this embodiment, in any configuration, the second retardation film is disposed so as to be closer to the liquid crystal cell.

  Another embodiment of the present invention is shown in FIG. In the liquid crystal display device of FIG. 3, the second retardation film 12 is disposed between the polarizing film 8 and the first retardation film 10. Also in the liquid crystal display device of FIG. 3, the protective film 7b or the protective film 19a has an arbitrary configuration and may not be provided. In the embodiment shown in FIG. 3, the first retardation film 10 has a slow axis 11 perpendicular 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 during black display. It is arranged to become. In the aspect of FIG. 3, the first retardation film and the second retardation film may be disposed between the liquid crystal cell and the viewing-side polarizing film with reference to the position of the liquid crystal cell. You may arrange | position between the liquid crystal cell and the polarizing film of the back side. In this embodiment, in any configuration, the first retardation film is disposed closer to the liquid crystal cell.

  Note that FIG. 3 shows a mode of a transmissive mode display device including an upper polarizing plate (film) and a lower polarizing plate (film), but the present invention is a reflective mode mode including only one polarizing plate. It may be. In such a case, since the optical path in the liquid crystal cell is doubled, the optimum value Δn · d is about ½ of the above value. In addition, the liquid crystal cell used in the present invention is not limited to the IPS mode, and any liquid crystal display device in which liquid crystal molecules are aligned substantially parallel to the surfaces of the pair of substrates during black display can be used. It can be used suitably. Examples of such a liquid crystal display device include a ferroelectric liquid crystal display device, an antiferroelectric liquid crystal display device, and an ECB type liquid crystal display device.

  Moreover, the liquid crystal display device of this invention is not limited to the structure shown in FIGS. 1-3, The other member may be included. For example, when a full-color liquid crystal display device is configured, a color filter may be disposed between the liquid crystal layer and the polarizing film. Further, an antireflection treatment or a hard coat may be applied to the surface of the protective film in the polarizing film. Moreover, you may use what gave electroconductivity to the structural member. Further, when used as a transmission type, a cold cathode or a hot cathode fluorescent tube, or a backlight having a light emitting diode, a field emission element or an electroluminescent element as a light source can be disposed on the back side. In this case, the arrangement of the backlight may be on the upper side or the lower side of FIGS.

  In addition, a reflective polarizing plate, a diffusion plate, a prism sheet, or a light guide plate can be disposed between the liquid crystal layer and the backlight. Furthermore, as described above, the liquid crystal display device of the present invention may be of a reflective type. In such a case, only one polarizing plate may be disposed on the observation side, and the back side of the liquid crystal cell or the lower side of the liquid crystal cell. A reflective film is disposed on the inner surface of the substrate. Of course, it is also possible to provide a front light using the 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. The present invention is particularly effective when applied to an active matrix liquid crystal display device using three-terminal or two-terminal semiconductor elements such as TFT and MIM. Of course, an embodiment applied to a passive matrix liquid crystal display device called time-division driving is also effective.

  Hereinafter, preferable optical characteristics, materials, manufacturing methods, and the like of the retardation film of the liquid crystal display device of the present invention will be described in detail.

[First retardation film]
The first retardation film used in the liquid crystal display device of the present invention has an in-plane retardation (Re) of 20 nm to 150 nm, and from the viewpoint of effectively reducing light leakage in an oblique direction, the first retardation film is used. The Re of the film is more preferably 40 nm to 115 nm, and particularly preferably 60 nm to 95 nm. Further, Nz of the first retardation film is 1.5 to 7, and from the viewpoint of effectively reducing light leakage in the oblique direction, Nz of the first retardation film is 2.0 to 5.5. Is more preferable, and 2.5 to 4.5 is particularly preferable.

  Basically, the material and form of the first retardation film are not particularly limited as long as it has the optical characteristics described above. Examples of the first retardation film include a retardation film made of a birefringent polymer film, a film heated after applying a polymer compound on a transparent support, and a low molecular or high-molecular liquid crystalline compound on the transparent support. Any one of a retardation film having a retardation layer formed by coating or transferring can be used. Moreover, each can also be laminated | stacked and used. When the first retardation film is made of a polymer film, it can function as a support for the optically anisotropic layer of the second retardation film described later.

  The birefringent polymer film is preferably one having excellent controllability of birefringence characteristics, transparency and heat resistance. In this case, the polymer material used for the birefringent polymer film is not particularly limited as long as it is a polymer that can achieve uniform biaxial orientation. Preferred are, for example, norbornene polymers, polycarbonate polymers, polyarylate polymers, polyester polymers, aromatic polymers such as polysulfone, cellulose acylate, or two or three of these polymers The polymer etc. which mixed the above are mentioned.

  The biaxial orientation of the film is a film made of the thermoplastic resin produced by an appropriate method such as an extrusion molding method or a casting film forming method, for example, a longitudinal stretching method using a roll, a transverse stretching method using a tenter, or a biaxial stretching method. For example, it can be achieved by performing a stretching treatment. In the above-described longitudinal stretching method using a roll, an appropriate heating method such as a method using a heating roll, a method of heating an atmosphere, or a method of using them together can be employed. In the biaxial stretching method using a tenter, an appropriate method such as a simultaneous biaxial stretching method using an all tenter method or a sequential biaxial stretching method using a roll tenter method can be employed. Moreover, as said birefringent polymer film, a thing with little orientation nonuniformity and phase difference nonuniformity is preferable. The thickness can be appropriately determined depending on the phase difference or the like, but is generally preferably 1 to 300 μm, more preferably 10 to 200 μm, and particularly preferably 20 to 150 μm from the viewpoint of thinning. preferable.

  The norbornene-based polymer is a polymer of monomers mainly composed of norbornene-based monomers such as norbornene and its derivatives, tetracyclododecene and its derivatives, dicyclopentadiene and its derivatives, methanotetrahydrofluorene and its derivatives, Ring-opening polymer of norbornene monomer, ring-opening copolymer of norbornene monomer and other monomer capable of ring-opening copolymerization, addition polymer of norbornene monomer, copolymerizable with norbornene monomer Examples include addition copolymers with other monomers and hydrogenated products thereof. Among these, from the viewpoints of heat resistance, mechanical strength, and the like, a ring-opening polymer hydride of a norbornene monomer is most preferable. The molecular weight of the norbornene-based polymer is appropriately selected according to the purpose of use. However, the polyisoprene or polystyrene equivalent measured by gel permeation chromatography of a cyclohexane solution (or a toluene solution when the polymer resin is not dissolved) is used. The weight average molecular weight is usually about 5,000 to 500,000, preferably 8,000 to 200,000, and more preferably 10,000 to 100,000. When it is in the above-mentioned range, the mechanical strength of the first retardation film and the molding processability are highly balanced and suitable.

  The acyl group of the cellulose acylate is not particularly limited and may be an aliphatic group or an allyl group. Examples of the cellulose acylate include cellulose alkylcarbonyl esters, alkenylcarbonyl esters, aromatic carbonyl esters, aromatic alkylcarbonyl esters, and the like, each of which may further have a substituent. As the substituent, an ester group having a total carbon number of 22 or less is preferable. Preferred cellulose acylates include, for example, acyl groups having an ester part with a total carbon number of 22 or less (for example, acetyl, propionyl, butyroyl, barrel, heptanoyl, octanoyl, decanoyl, dodecanoyl, tridecanoyl, hexadecanoyl, octadecanoyl, etc. ), Arylcarbonyl groups (such as acrylic and methacrylic), allylcarbonyloxy (such as benzoyl and naphthaloyl), and cinnamoyl groups. Among these, cellulose acetate, cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate stearate, cellulose acetate benzoate and the like are preferable. In the case of mixed ester, the ratio is not particularly limited, but acetate is 30 mol of total ester. % Or more is preferable.

Among these, as the polymer material used for the birefringent polymer film, cellulose acylate is preferable, and photographic grade cellulose acylate is particularly preferable. The commercially available photographic grade cellulose acylate has good quality such as viscosity average degree of polymerization and degree of substitution.
Examples of the photographic grade cellulose triacetate include Daicel Chemical Industries, Ltd. (for example, LT-20, 30, 40, 50, 70, 35, 55, 105, etc.) and Eastman Kodak Company (for example, 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.), those manufactured by Courtles Co., Ltd., Hoechst Co., etc. are preferred, and any of photographic grade cellulose acylates can be used. Further, for the purpose of controlling the mechanical properties and optical properties of the film, as described in JP 2002-277632 A, JP 2002-182215 A, etc., a plasticizer, a surfactant, a letter It is possible to mix a foundation regulator, UV absorber, etc.

  As a method for forming the transparent resin into a sheet or film, for example, either a hot melt molding method or a solution casting method can be used. The heat-melt molding method can be further classified into an extrusion molding method, a press molding method, an inflation molding method, an injection molding method, a blow molding method, a stretch molding method, etc. Among these methods, mechanical strength, surface In order to obtain a film excellent in accuracy and the like, the extrusion molding method, the inflation molding method, and the press molding method are preferable, and the extrusion molding method is most preferable. The molding conditions are appropriately selected depending on the purpose of use and the molding method. In the case of the heat-melt molding method, the cylinder temperature is preferably set in the range of preferably 100 to 200 ° C, more preferably 150 to 350 ° C. The thickness of the sheet or film is preferably 1 to 300 μm, preferably 10 to 200 μm, more preferably 20 to 150 μm.

  When the glass transition temperature of the transparent resin is Tg, the stretching of the sheet or film is preferably in a temperature range of Tg-30 ° C to Tg + 60 ° C, more preferably in a temperature range of Tg-10 ° C to Tg + 50 ° C. In at least one direction, the stretching ratio is preferably 1.01 to 2 times. The stretching direction may be at least one direction, but when the sheet is obtained by extrusion, the direction is preferably the mechanical flow direction (extrusion direction) of the resin. A free shrink uniaxial stretching method, a fixed width uniaxial stretching method, a biaxial stretching method, and the like are preferable. The optical characteristics can be controlled by controlling the draw ratio and the heating temperature.

[Second retardation film]
The in-plane refractive indexes of the second retardation film used in the liquid crystal display device of the present invention are substantially equal, and the retardation (Rth) in the thickness direction is −80 nm to −400 nm. “The in-plane refractive index is substantially equal” means that the in-plane retardation is substantially in the vicinity of 0, and the range is specifically 0 to 20 nm. The more preferable range of Rth of the second retardation film varies depending on the optical characteristics of the other optical members, and in particular, the Rth of the protective film (for example, triacetylcellulose film) of the polarizing film located closer to the optical film. Depending on the situation, it varies greatly. In order to effectively reduce the light leakage in the oblique direction, the Rth of the second retardation film is more preferably −100 nm to −340 nm, and further preferably −120 nm to −270 nm. On the other hand, Re of the second retardation film is substantially a value near zero. Specifically, Re is preferably 0 to 20 nm.

The second retardation film is a film having at least one layer formed by fixing a rod-like liquid crystal compound or composition having a positive refractive index anisotropy substantially perpendicularly to a substrate and then fixing it. Further, the second retardation film can be formed by laminating not only one retardation layer but also a plurality of retardation layers to form the second retardation film exhibiting the above optical characteristics. In addition, the second retardation film may be configured so that the entire laminated body of the support and the retardation layer satisfies the optical characteristics. The second retardation film includes at least the retardation film of the present invention described later.
The term “substantially perpendicular” means that the angle formed between the film surface and the director of the rod-like liquid crystal compound is in the range of 70 ° to 90 °. These liquid crystalline compounds may be aligned obliquely or may be changed so that the inclination angle gradually changes (hybrid alignment). Even in the case of oblique alignment or hybrid alignment, the average inclination angle is preferably 70 ° to 90 °, more preferably 80 ° to 90 °, and most preferably 85 ° to 90 °.

[Liquid Crystal Cell]
The retardation film of the present invention can be used for a liquid crystal display device having liquid crystal cells of various display modes. As described above, the retardation film of the present invention is useful as an optical compensation sheet for liquid crystal cells. As for the optical compensation sheet having an optically anisotropic layer made of liquid crystalline molecules, the transmission type includes TN (Twisted Nematic), IPS (In-Plane Switching), FLC (Ferroelectric Liquid Crystal), OCB (Optically Compensatory STN Bend). (Super Twisted Nematic), VA (Vertically Aligned), ECB (Electrically Controlled Birefringence), and reflection type are TN, HAN (Hybrid Aligned Nematic), G Yes. The retardation film of the present invention can be applied to various liquid crystal display modes depending on the alignment state, but can be suitably used for a transmissive IPS mode.

<< Retardation Film of the Present Invention >>
The second retardation film in the liquid crystal display device of the present invention is obtained by fixing a rod-like liquid crystal compound or composition having a positive refractive index anisotropy in the optically anisotropic layer after being substantially vertically aligned on the substrate. The formed layer is preferable. Hereinafter, the retardation film of the present invention that is suitably used for the second retardation film in the liquid crystal display device of the present invention will be described in detail.
In the retardation film of the present invention, an alignment film made of at least one polymer and an optically anisotropic layer made of a liquid crystal composition containing at least one rod-like liquid crystalline compound and at least one boronic acid compound are arranged in this order. It is provided.

[Optically anisotropic layer]
First, the optically anisotropic layer will be described. The optically anisotropic layer is composed of a liquid crystal composition containing at least one rod-like liquid crystalline compound and at least one boronic acid compound. The rod-like liquid crystal compound may be a low molecular compound or a high molecular compound, but is preferably a low molecular compound in order to quickly form a desired alignment state. Moreover, in order to fix the orientation state and obtain a film, it is preferable to have a polymerizable group. The rod-like liquid crystal compound having polymerizability may be used alone or in a mixture using some of the polymerizable or non-polymerizable rod-like liquid crystal compounds. Individual liquid crystalline compounds used alone or in combination may form a nematic liquid crystal phase, a smectic liquid crystal phase, or a cholesteric liquid crystal phase. In addition, as described later, when applying the liquid crystal composition, a composition containing an additive such as a solvent or a polymerization initiator is applied, but as a liquid crystal composition in a state where the solvent is volatilized in the process of heating and drying. Those having a smectic liquid crystal phase in a temperature range in which the orientation is fixed are preferably used.

(Bar-shaped liquid crystalline compound)
The retardation film of the present invention is formed from a composition containing a rod-like liquid crystal compound. Examples of the rod-like liquid crystalline compound include azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoic acid esters, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, alkoxy-substituted phenylpyrimidines. , Phenyldioxanes, tolanes and alkenylcyclohexylbenzonitriles are preferably used. In addition to the low-molecular liquid crystals as described above, polymer liquid crystals can also be used. As the rod-like liquid crystalline compound, those having a partial structure capable of causing polymerization or a crosslinking reaction by actinic rays, electron beams, heat, or the like are suitably used. The number of the partial structures is 1 to 6, preferably 1 to 3. As described above, the rod-like liquid crystalline molecules that can be used in the present invention preferably have a polymerizable group in order to fix the alignment state. The polymerizable group is preferably a radically polymerizable unsaturated group, and specific examples thereof include a polymerizable group and a polymerizable liquid crystal compound described in JP-T-2000-514202 or JP-A-2002-62427. In the retardation film of the present invention, the rod-like liquid crystal compound is preferably oriented perpendicular to the substrate or support, that is, perpendicular to the film surface of the retardation film.

  As described above, it is more preferable to fix the alignment of the rod-like liquid crystalline molecules by polymerization. Chem. 190, 2255 (1989), Advanced Materials 5, 107 (1993), U.S. Pat. Nos. 4,683,327, 5,622,648, 5,770,107, WO 95/22586, 95/24455, 97/97. No. 0600, No. 98/23580, No. 98/52905, JP-A-1-272551, JP-A-6-16616, JP-A-7-110469, JP-A-11-80081, and Japanese Patent Application No. 2001-64627 These compounds can be used. More preferably, it is a compound represented by the following general formula (II).

^{(IV) Q 1 -L 1 -Cy} 1 -L 2 - (Cy 2 -L 3) n -Cy 3 -L 4 -Q 2
In the formula, Q ¹ and Q ² are each independently a polymerizable group, L ¹ and L ⁴ are each independently a divalent linking group, and L ² and L ³ are each independently a single bond or a divalent group. It is a linking group, Cy ¹ , Cy ² and Cy ³ are divalent cyclic groups, and n is 0, 1 or 2.

The polymerizable rod-like liquid crystal compound will be further described below.
^{(IV) Q 1 -L 1 -Cy} 1 -L 2 - (Cy 2 -L 3) n -Cy 3 -L 4 -Q 2
In the formula, Q ¹ and Q ² are each independently a polymerizable group. The polymerization reaction of the polymerizable group is preferably addition polymerization (including ring-opening polymerization) or condensation polymerization. In other words, the polymerizable group is preferably a functional group capable of addition polymerization reaction or condensation polymerization reaction. Examples of polymerizable groups are shown below.

L ¹ and L ⁴ are each independently a divalent linking group. L ¹ and L ⁴ are each independently selected from the group consisting of —O—, —S—, —CO—, —NR ² —, a divalent chain group, a divalent cyclic group, and combinations thereof. A valent linking group is preferred. R ² is an alkyl group having 1 to 7 carbon atoms or a hydrogen atom. R ² is preferably an alkyl group having 1 to 4 carbon atoms or a hydrogen atom, more preferably a methyl group, an ethyl group or a hydrogen atom, and most preferably a hydrogen atom. The example of the bivalent coupling group which consists of a combination is shown below. Here, the left side is coupled to Q (Q ¹ or Q ² ), and the right side is coupled to Cy (Cy ¹ or Cy ³ ).

L-1: —CO—O—divalent chain group—O—
L-2: —CO—O—divalent chain group —O—CO—
L-3: —CO—O—divalent chain group —O—CO—O—
L-4: -CO-O-divalent chain group -O-divalent cyclic group-
L-5: —CO—O—divalent chain group—O—divalent cyclic group—CO—O—
L-6: -CO-O-divalent chain group -O-divalent cyclic group -O-CO-
L-7: -CO-O-divalent chain group-O-divalent cyclic group-divalent chain group-
L-8: -CO-O-divalent chain group-O-divalent cyclic group-divalent chain group-CO-O-
L-9: -CO-O-divalent chain group-O-divalent cyclic group-divalent chain group-O-CO-
L-10: —CO—O—divalent chain group—O—CO—divalent cyclic group—
L-11: -CO-O-divalent chain group-O-CO-divalent cyclic group-CO-O-
L-12: -CO-O-divalent chain group -O-CO-divalent cyclic group -O-CO-
L-13: —CO—O—Divalent chain group—O—CO—Divalent cyclic group—Divalent chain group—L-14: —CO—O—Divalent chain group—O -CO-divalent cyclic group-divalent chain group-CO-O-
L-15: -CO-O-divalent chain group-O-CO-divalent cyclic group-divalent chain group-O-CO-
L-16: —CO—O—divalent chain group—O—CO—O—divalent cyclic group—
L-17: -CO-O-divalent chain group -O-CO-O-divalent cyclic group -CO-O-
L-18: -CO-O-divalent chain group -O-CO-O-divalent cyclic group -O-CO-
L-19: —CO—O—divalent chain group—O—CO—O—divalent cyclic group—divalent chain group—
L-20: -CO-O-divalent chain group-O-CO-O-divalent cyclic group-divalent chain group-CO-O-
L-21: -CO-O-divalent chain group-O-CO-O-divalent cyclic group-divalent chain group-O-CO-

  The divalent chain group means an alkylene group, a substituted alkylene group, an alkenylene group, a substituted alkenylene group, an alkynylene group, or a substituted alkynylene group. An alkylene group, a substituted alkylene group, an alkenylene group and a substituted alkenylene group are preferred, and an alkylene group and an alkenylene group are more preferred. The alkylene group may have a branch. The alkylene group preferably has 1 to 12 carbon atoms, more preferably 2 to 10 carbon atoms, and most preferably 2 to 8 carbon atoms. The alkylene part of the substituted alkylene group is the same as the above alkylene group. Examples of the substituent include a halogen atom. The alkenylene group may have a branch. The alkenylene group preferably has 2 to 12 carbon atoms, more preferably 2 to 10 carbon atoms, and most preferably 2 to 8 carbon atoms. The alkenylene part of the substituted alkenylene group is the same as the above alkenylene group. Examples of the substituent include a halogen atom. The alkynylene group may have a branch. The alkynylene group preferably has 2 to 12 carbon atoms, more preferably 2 to 10 carbon atoms, and most preferably 2 to 8 carbon atoms. The alkynylene part of the substituted alkynylene group is the same as the above alkynylene group. Examples of the substituent include a halogen atom.

  Specific examples of the divalent chain group include ethylene, propylene, tetramethylene, 2-methyl-1,4-butylene, pentamethylene, hexamethylene, octamethylene, 2-butenylene, 2-butynylene and the like.

The definition and examples of the divalent cyclic group are the same as those of Cy ¹ , Cy ² and Cy ³ described later.

L ^{2 and} L ³ are each independently a single bond or a divalent linking group. L ² and L ³ are each independently two selected from the group consisting of —O—, —S—, —CO—, —NR ² —, a divalent chain group, a divalent cyclic group, and combinations thereof. A valent linking group or a single bond is preferred. R ² is an alkyl group having 1 to 7 carbon atoms or a hydrogen atom, preferably an alkyl group having 1 to 4 carbon atoms or a hydrogen atom, and is a methyl group, an ethyl group or a hydrogen atom. Is more preferable, and a hydrogen atom is most preferable. The divalent chain group and the divalent cyclic group have the same definitions as L ¹ and L ⁴ .

In the formula (IV), n is 0, 1 or 2. When n is 2, two L ³ may be the same or different, and two Cy ² may be the same or different. n is preferably 1 or 2, and more preferably 1.

In formula (IV), Cy ¹ , Cy ² and Cy ³ are each independently a divalent cyclic group. The ring contained in the cyclic group is preferably a 5-membered ring, a 6-membered ring, or a 7-membered ring, more preferably a 5-membered ring or a 6-membered ring, and most preferably a 6-membered ring. The ring contained in the cyclic group may be a condensed ring. However, it is more preferably a monocycle than a condensed ring. The ring contained in the cyclic group may be any of an aromatic ring, an aliphatic ring, and a heterocyclic ring. Examples of the aromatic ring include a benzene ring and a naphthalene ring. Examples of the aliphatic ring include a cyclohexane ring. Examples of the heterocyclic ring include a pyridine ring and a pyrimidine ring. As the cyclic group having a benzene ring, 1,4-phenylene is preferable. As the cyclic group having a naphthalene ring, naphthalene-1,5-diyl and naphthalene-2,6-diyl are preferable. The cyclic group having a cyclohexane ring is preferably 1,4-cyclohexylene. As the cyclic group having a pyridine ring, pyridine-2,5-diyl is preferable. The cyclic group having a pyrimidine ring is preferably pyrimidine-2,5-diyl.

  The cyclic group may have a substituent. Examples of the substituent include a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 5 carbon atoms, a halogen-substituted alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms. , An alkylthio group having 1 to 5 carbon atoms, an acyloxy group having 2 to 6 carbon atoms, an alkoxycarbonyl group having 2 to 6 carbon atoms, a carbamoyl group, and an alkyl-substituted carbamoyl group having 2 to 6 carbon atoms And an acylamino group having 2 to 6 carbon atoms.

  Examples of the polymerizable liquid crystal compound represented by the formula (IV) are shown below. The present invention is not limited to these.

(Boronic acid compound)
In the liquid crystal composition forming the optically anisotropic layer of the retardation film of the present invention, at least one boronic acid compound is used as a vertical alignment accelerator on the alignment film interface side. In the present invention, the boronic acid compound contributes to the vertical alignment of the rod-like liquid crystal compound at the interface with the alignment film.

The boronic acid compound used in the present invention represents, for example, a compound having at least one boronic acid group or boronic ester group, and a metal complex having these as a ligand, or tetracoordinate boron. A boronium ion having an atom is also represented.
The boronic acid compound used in the present invention is preferably represented by the following general formula (I), and the compound represented by the following general formula (I) will be described in detail below.

In general formula (I), R ¹ and R ² each independently represents a hydrogen atom, a substituted or unsubstituted aliphatic hydrocarbon group, an aryl group, or a heterocyclic group. Examples of the aliphatic hydrocarbon group include a substituted or unsubstituted linear or branched alkyl group having 1 to 20 carbon atoms (for example, a methyl group, an ethyl group, an iso-propyl group, etc.), Examples thereof include an unsubstituted cyclic alkyl group (for example, cyclohexyl group) and an alkenyl group having 2 to 20 carbon atoms (for example, a vinyl group). As the aryl group, substituted or unsubstituted phenyl having 6 to 20 carbon atoms. A group (for example, phenyl group, tolyl group, etc.), a substituted or unsubstituted naphthyl group having 10 to 20 carbon atoms, and the like. Examples of the heterocyclic group include at least one hetero atom (for example, nitrogen atom, oxygen atom). A substituted or unsubstituted 5- or 6-membered ring group containing, for example, a pyridyl group, an imidazolyl group, a furyl group, a piperidyl group, Ruhorino group, and the like. These may be connected to each other to form a ring. For example, the isopropyl groups of R ¹ and R ² are connected to form a 4,4,5,5-tetramethyl-1,3,2-dioxaborolane ring. You may do it.

In general formula (I), R ¹ and R ² are preferably a hydrogen atom or a linear or branched alkyl group having 1 to 3 carbon atoms, and a case where they are linked to form a ring, Most preferably, it is a hydrogen atom.

In general formula (I), R ³ represents a substituted or unsubstituted aliphatic hydrocarbon group, aryl group or heterocyclic group. Examples of the aliphatic hydrocarbon group include a substituted or unsubstituted linear or branched alkyl group having 1 to 30 carbon atoms (for example, methyl group, ethyl group, iso-propyl group, n-propyl group, butyl group, pentyl group). Hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, hexadecyl group, octadecyl group, eicosyl group, isopropyl group, isobutyl group, sec-butyl group, tert-butyl group, Isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-methylhexyl group, etc.), substituted or unsubstituted cyclic alkyl group having 3 to 20 carbon atoms (for example, cyclopentyl group, cyclohexyl group, 1-adamantyl group, 2-norbornyl group, etc.), alkenyl groups having 2 to 20 carbon atoms (for example, vinyl Bi, 1-propenyl group, 1-butenyl group, 1-methyl-1-propenyl group and the like. As the aryl group, a substituted or unsubstituted phenyl group having 6 to 50 carbon atoms (for example, phenyl group, A tolyl group, a styryl group, a 4-benzoyloxyphenyl group, a 4-phenoxycarbonylphenyl group, a 4-biphenyl group, a 4- (4-octyloxybenzoyloxy) phenoxycarbonylphenyl group, etc.), a C10-50 substitution or Examples thereof include an unsubstituted naphthyl group (for example, an unsubstituted naphthyl group), and examples of the heterocyclic group include a substituted or unsubstituted group containing at least one hetero atom (for example, a nitrogen atom, an oxygen atom, a sulfur atom, etc.). Substituted 5- or 6-membered groups such as pyrrole, furan, thiophene, pyrazole, imidazole, Riazole, oxazole, isoxazole, oxadiazole, thiazole, thiadiazole, indole, carbazole, benzofuran, dibenzofuran, thianaphthene, dibenzothiophene, indazole benzimidazole, anthranyl, benzisoxazole, benzoxazole, benzothiazole, purine, pyridine, pyridazine, Examples include pyrimidine, pyrazine, triazine, quinoline, acridine, isoquinoline, phthalazine, quinazoline, quinoxaline, naphthyridine, phenanthroline, pteridine, morpholine, piperidine and the like.

Furthermore, one or more of these aliphatic hydrocarbon groups, aryl groups, and heterocyclic groups included in the heterocyclic group may be substituted with any substituent. Examples of the substituent include monovalent non-metallic atomic groups excluding hydrogen, halogen atoms (—F, —Br, —Cl, —I), hydroxyl groups, alkoxy groups, aryloxy groups, mercapto groups, alkylthio groups. , Arylthio group, alkyldithio group, aryldithio group, amino group, N-alkylamino group, N, N-dialkylamino group, N-arylamino group, N, N-diarylamino group, N-alkyl-N-aryl Amino group, acyloxy group, carbamoyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group, N, N-dialkylcarbamoyloxy group, N, N-diarylcarbamoyloxy group, N-alkyl-N-arylcarbamoyl Oxy, alkylsulfoxy, arylsulfoxy, acylthio Group, acylamino group, N-alkylacylamino group, N-arylacylamino group, ureido group, N′-alkylureido group, N ′, N′-dialkylureido group, N′-arylureido group, N ′, N '-Diarylureido group, N'-alkyl-N'-arylureido group, N-alkylureido group, N-arylureido group, N'-alkyl-N-alkylureido group, N'-alkyl-N-arylureido Group, N ′, N′-dialkyl-N-alkylureido group, N ′, N′-dialkyl-N-arylureido group, N′-aryl-N-alkylureido group, N′-aryl-N-arylureido Group, N ′, N′-diaryl-N-alkylureido group, N ′, N′-diaryl-N-arylureido group, N′-alkyl-N′-aryl-N-alkyl Raid group, N′-alkyl-N′-aryl-N-arylureido group, alkoxycarbonylamino group, aryloxycarbonylamino group, N-alkyl-N-alkoxycarbonylamino group, N-alkyl-N-aryloxycarbonyl Amino group, N-aryl-N-alkoxycarbonylamino group, N-aryl-N-aryloxycarbonylamino group, formyl group, acyl group, carboxyl group and its conjugate base group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl Group, N-alkylcarbamoyl group, N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, N, N-diarylcarbamoyl group, N-alkyl-N-arylcarbamoyl group, alkylsulfinyl group, arylsulfinyl group, alkyl Sulfonyl group, arylsulfonyl group, sulfo group (—SO ₃ H) and its conjugate base group, alkoxysulfonyl group, aryloxysulfonyl group, sulfinamoyl group, N-alkylsulfinamoyl group, N, N-dialkylsulfinamoyl group N-arylsulfinamoyl group, N, N-diarylsulfinamoyl group, N-alkyl-N-arylsulfinamoyl group, sulfamoyl group, N-alkylsulfamoyl group, N, N-dialkylsulfamoyl group Group, N-arylsulfamoyl group, N, N-diarylsulfamoyl group, N-alkyl-N-arylsulfamoyl group, N-acylsulfamoyl group and its conjugate base group, N-alkylsulfonylsulfur group Famoiru group _{(-SO 2 NHSO 2 (alkyl)} ) and its conjugated base group N- aryl acylsulfamoyl group _{(-SO 2 NHSO 2 (aryl)} ) and its conjugated base group, N- alkylsulfonylcarbamoyl group (-CONHSO ₂ (alkyl)) and its conjugated base group, N- aryl sulfonyl carbamoyl group (—CONHSO ₂ (aryl)) and its conjugate base group, alkoxysilyl group (—Si (Oalkyl) ₃ ), aryloxysilyl group (—Si (Oaryl) ₃ ), hydroxysilyl group (—Si (OH) ₃ ) And its conjugate base group, phosphono group (—PO ₃ H ₂ ) and its conjugate base group, dialkylphosphono group (—PO ₃ (alkyl) ₂ ), diarylphosphono group (—PO ₃ (aryl) ₂ ), alkyl Arylphosphono group (—PO ₃ (alkyl) (aryl)), monoalkylphosphono group (—PO ₃ H (alkyl)) and its conjugate base group, monoarylphosphono group (—PO ₃ H (aryl)) and its conjugate base group, phosphonooxy group (—OPO ₃ H ₂ ) and its conjugate base group, dialkylphosphonooxy Group (—OPO ₃ (alkyl) ₂ ), diarylphosphonooxy group (—OPO ₃ (aryl) ₂ ), alkylarylphosphonooxy group (—OPO ₃ (alkyl) (aryl)), monoalkylphosphonooxy group (—OPO ₃ H (alkyl)) and its conjugate base group, monoarylphosphonooxy group (—OPO ₃ H (aryl)) and its conjugate base group, cyano group, nitro group, aryl group, alkenyl group, alkynyl group Is mentioned. In addition, these substituents may combine with each other or with a substituted hydrocarbon group to form a ring, if possible.

R ³ in the general formula (I) is preferably a substituted or unsubstituted aryl group having 6 to 40 carbon atoms, more preferably phenyl having a substituent containing at least one aryl group or heterocyclic group. More preferably, it is a phenyl group substituted at the 4-position by a substituent containing 2 to 4 phenyl groups.

Moreover, it is preferable that the boronic acid compound represented by the general formula (I) is substituted with a crosslinkable group, since the adhesion between the support and the optically anisotropic layer is improved. It is preferable that a crosslinkable group is contained in R ³ . The crosslinkable group is generally a polymerizable group such as a vinyl group, an acrylate group, a methacrylate group, an acrylamide group, a styryl group, a vinyl ketone group, a butadiene group, a vinyl ether group, an oxiranyl group, an aziridinyl group, or an oxetane group. Examples thereof include a polymerizable group, preferably a vinyl group, an acrylate group, a methacrylate group, a styryl group, an oxiranyl group or an oxetane group, and most preferably a vinyl group, an acrylate group, an acrylamide group or a styryl group.

  Although the specific example of a compound represented by general formula (I) below is shown, the compound used for this invention is not limited to these.

  Boronic acid compounds are generally easily synthesized by using commercially available boronic acid compounds as they are, or by subjecting a boronic acid compound having a substituent as a raw material to general synthetic reactions such as esterification, amidation, and alkylation. I can do it. When a commercially available boronic acid compound is not used, for example, it is synthesized from a halide (for example, aryl bromide) by n-butyllithium and trialkoxyborane (for example, trimethoxyborane), or metal magnesium is used. It can be synthesized by performing a Wittig reaction.

  The preferred range of the content of the boronic acid compound in the liquid crystal composition varies depending on the use, but from the viewpoint of use in forming the optically anisotropic layer, the composition (a composition excluding the solvent in the case of a coating liquid) ) Is preferably 0.005 to 8% by mass, more preferably 0.01 to 5% by mass, and still more preferably 0.05 to 1% by mass.

(Other additives)
The retardation film of the present invention formed from the above liquid crystal composition contains, in addition to the rod-like liquid crystalline compound and the boronic acid compound, other additives such as the following polymerizable initiator and air interface vertical alignment agent as desired. The coating liquid (liquid crystal composition) can be formed by coating on an alignment film formed on a support, vertically aligning, and fixing the alignment state. When the retardation film of the present invention is formed on a temporary support, it can also be produced by transferring the retardation film onto a support. Furthermore, not only the retardation film of the present invention but also a plurality of retardation films can be laminated to constitute the second retardation film exhibiting the above-mentioned optical characteristics. Further, the second retardation film may be configured so that the entire laminated body of the support and the retardation film of the present invention satisfies the optical characteristics described above.

  In the retardation film of the present invention, the vertically aligned rod-like liquid crystalline compound is preferably fixed while maintaining the alignment state. The immobilization is preferably performed by a polymerization reaction of the polymerizable group (P) introduced into the rod-like liquid crystal compound. The polymerization reaction includes a thermal polymerization reaction using a thermal polymerization initiator and a photopolymerization reaction using a photopolymerization initiator, and a photopolymerization reaction is preferred. Examples of the photopolymerization initiator include α-carbonyl compounds (described in the specifications of US Pat. Nos. 2,367,661 and 2,367,670), acyloin ether (US Pat. No. 2,448,828). Description), α-hydrocarbon substituted aromatic acyloin compound (described in US Pat. No. 2,722,512), polynuclear quinone compound (US Pat. Nos. 3,046,127 and 2,951,758) Description), a combination of triarylimidazole dimer and p-aminophenyl ketone (described in US Pat. No. 3,549,367), acridine and phenazine compound (Japanese Patent Laid-Open No. 60-105667, US Pat. 239,850 description) and oxadiazole compounds (described in US Pat. No. 4,212,970).

The amount of the photopolymerization initiator used is preferably 0.01 to 20% by mass, more preferably 0.5 to 5% by mass, based on the solid content of the coating solution. Moreover, it is preferable to use ultraviolet rays for light irradiation for polymerization of the rod-like liquid crystalline molecules. The irradiation energy is preferably 20 mJ / cm ^{2 to} 50 J / cm ² , and more preferably 100 mJ / cm ^{2 to} 800 mJ / cm ² . Furthermore, in order to accelerate the photopolymerization reaction, light irradiation may be performed under heating conditions. The thickness of the retardation film of the present invention including the optically anisotropic layer is preferably 0.1 to 10 μm, more preferably 0.5 to 5 μm, and most preferably 1 to 5 μm. preferable.

  Usually, since the liquid crystalline compound has a property of being inclined and aligned on the air interface side, it is necessary to control the alignment of the liquid crystalline compound vertically on the air interface side in order to obtain a uniformly vertically aligned state. . For this purpose, the liquid crystal composition contains a compound (air interface alignment agent) that is unevenly distributed on the air interface side and acts to vertically align the liquid crystalline compound by its excluded volume effect or electrostatic effect. The retardation film of the present invention is preferably formed.

  As the air interface alignment agent, compounds described in JP-A Nos. 2002-20363 and 2002-129162 can be used. Also, paragraph numbers [0072] to [0075] of Japanese Patent Application Laid-Open No. 2004-053981, paragraph numbers [0071] to [0078] of Japanese Patent Application Laid-Open No. 2004-004688, and paragraph number [0052] of Japanese Patent Application Laid-Open No. 2004-139015. ] To [0054], [0065] to [0066], and [0092] to [0094] can be appropriately applied to the present invention. Furthermore, the following compounds can also be used.

  Moreover, the compound which has a fluoro aliphatic group and a hydrophilic group can also be used as an air interface side vertical alignment agent. Specifically, it is preferably a fluoropolymer having a fluoroaliphatic group and one or more hydrophilic groups, or a fluorine-containing compound represented by the following general formula (2).

<< Fluoropolymer >>
The fluoropolymer is selected from the group consisting of a fluoroaliphatic group, a carboxyl group (—COOH), a sulfo group (—SO ₃ H), a phosphonoxy group {—OP (═O) (OH) ₂ }, and salts thereof. A fluorine-based polymer having one or more hydrophilic groups can be used. The types of polymers are described in “Revised Chemistry of Polymer Synthesis” (Takayuki Otsu, published by Kagaku Dojin Co., 1968), pages 1-4, for example, polyolefins, polyesters, polyamides, polyimides. , Polyurethanes, polycarbonates, polysulfones, polycarbonates, polyethers, polyacetals, polyketones, polyphenylene oxides, polyphenylene sulfides, polyarylates, PTFEs, polyvinylidene fluorides, cellulose derivatives, etc. It is done. The fluoropolymer is preferably a polyolefin.

  The fluorine-based polymer is a polymer having a fluoroaliphatic group in the side chain. The fluoroaliphatic group preferably has 1 to 12 carbon atoms, and more preferably 6 to 10 carbon atoms. The aliphatic group may be linear or cyclic, and when it is linear, it may be linear or branched. Of these, a linear fluoroaliphatic group having 6 to 10 carbon atoms is preferable. The degree of substitution with fluorine atoms is not particularly limited, but 50% or more of hydrogen atoms in the aliphatic group are preferably substituted with fluorine atoms, and more preferably 60% or more are substituted. The fluoroaliphatic group is contained in a side chain bonded to the polymer main chain via an ester bond, an amide bond, an imide bond, a urethane bond, a urea bond, an ether bond, a thioether bond, an aromatic ring, or the like. One of the fluoroaliphatic groups is derived from a fluoroaliphatic compound produced by a telomerization method (also referred to as a telomer method) or an oligomerization method (also referred to as an oligomer method). Regarding the production method of these fluoroaliphatic compounds, for example, “Synthesis and Function of Fluorine Compounds” (Supervision: Nobuo Ishikawa, Issue: CMC Co., 1987), “Chemistry of Organic Fluorines Compounds”. II "(Monograph 187, Ed by Milos Hudricky and Attila E. Pavlath, American Chemical Society 1995). The telomerization method is a method of synthesizing a telomer by radical polymerization of a fluorine-containing vinyl compound such as tetrafluoroethylene using an alkyl halide having a large chain transfer constant such as iodide as a telogen (example in Scheme-1). showed that).

  The obtained terminal iodinated telomer is usually subjected to appropriate terminal chemical modification such as [Scheme 2], and led to a fluoroaliphatic compound. These compounds are further converted into a desired monomer structure as necessary, and used for the production of a fluoroaliphatic group-containing polymer.

  Specific examples of the fluoroaliphatic group-containing monomer that can be used in the production of the fluoropolymer that can be used in the present invention are listed below, but the compounds that can be used in the present invention are not limited in any way by the following specific examples. Absent.

  One aspect of the fluoropolymer usable in the present invention is a copolymer having a repeating unit derived from a fluoroaliphatic group-containing monomer and a repeating unit containing a hydrophilic group represented by the following general formula (1). It is a polymer.

In the general formula (1), R ¹ , R ² and R ³ each independently represent a hydrogen atom or a substituent. Q represents a carboxyl group (—COOH) or a salt thereof, a sulfo group (—SO ₃ H) or a salt thereof, a phosphonoxy group {—OP (═O) (OH) ₂ } or a salt thereof. L represents an arbitrary group selected from the following linking group group, or a divalent linking group formed by combining two or more thereof.
(Linked group group)
Single bond, —O—, —CO—, —NR ⁴ — (R ⁴ represents a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group), —S—, —SO ₂ —, —P (═O) (OR ⁵ ) — (R ⁵ represents an alkyl group, an aryl group, or an aralkyl group), an alkylene group, and an arylene group.

In general formula (1), R ¹ , R ² and R ³ each independently represent a hydrogen atom or a substituent selected from the following substituent group Y.
(Substituent group Y)
An alkyl group (preferably an alkyl group having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, such as a methyl group, an ethyl group, an isopropyl group, a tert-butyl group, n-octyl group, n-decyl group, n-hexadecyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group and the like, alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, Particularly preferred is an alkenyl group having 2 to 8 carbon atoms, such as vinyl group, allyl group, 2-butenyl group, 3-pentenyl group and the like, and alkynyl group (preferably having 2 to 20 carbon atoms, more preferably Is an alkynyl group having 2 to 12 carbon atoms, particularly preferably 2 to 8 carbon atoms, and examples thereof include a propargyl group and a 3-pentynyl group. An aryl group (preferably an aryl group having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, and particularly preferably 6 to 12 carbon atoms, such as a phenyl group, a p-methylphenyl group, and a naphthyl group. Aralkyl groups (preferably 7 to 30 carbon atoms, more preferably 7 to 20 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as benzyl group, phenethyl group, 3- Phenylpropyl group and the like), a substituted or unsubstituted amino group (preferably an amino group having 0 to 20 carbon atoms, more preferably 0 to 10 carbon atoms, particularly preferably 0 to 6 carbon atoms, Unsubstituted amino group, methylamino group, dimethylamino group, diethylamino group, anilino group, etc.),

An alkoxy group (preferably an alkoxy group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 10 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, and a butoxy group). An alkoxycarbonyl group (preferably an alkoxycarbonyl group having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms such as a methoxycarbonyl group and an ethoxycarbonyl group), acyloxy A group (preferably an acyloxy group having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms such as an acetoxy group and a benzoyloxy group), an acylamino group (preferably 2-20 carbon atoms, more preferably 2-16 carbon atoms, particularly preferably 2-10 carbon atoms. A silamino group, for example, an acetylamino group, a benzoylamino group, and the like, an alkoxycarbonylamino group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, and particularly preferably 2 to 12 carbon atoms). An alkoxycarbonylamino group, for example, a methoxycarbonylamino group), an aryloxycarbonylamino group (preferably having 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, and particularly preferably 7 to 12 carbon atoms). Aryloxycarbonylamino group, for example, phenyloxycarbonylamino group and the like, sulfonylamino group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 1 carbon atoms). 12 sulfonylamino groups such as methanesulfonyl And sulfamoyl groups (preferably having 0 to 20 carbon atoms, more preferably 0 to 16 carbon atoms, and particularly preferably 0 to 12 carbon atoms, such as sulfamoyl group). Group, methylsulfamoyl group, dimethylsulfamoyl group, phenylsulfamoyl group and the like), carbamoyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably carbon number). 1 to 12 carbamoyl groups, for example, unsubstituted carbamoyl group, methylcarbamoyl group, diethylcarbamoyl group, phenylcarbamoyl group and the like),

An alkylthio group (preferably an alkylthio group having 1 to 20 carbon atoms, more preferably an alkylthio group having 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as a methylthio group and an ethylthio group), an arylthio group ( Preferably it is C6-C20, More preferably, it is C6-C16, Most preferably, it is C6-C12 arylthio group, for example, a phenylthio group etc. are mentioned, A sulfonyl group (preferably C1-C1). 20, more preferably a sulfonyl group having 1 to 16 carbon atoms, particularly preferably a sulfonyl group having 1 to 12 carbon atoms, such as a mesyl group and a tosyl group, and a sulfinyl group (preferably having a carbon number of 1 to 20, more A sulfinyl group having 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms is preferable. Zensulfinyl group and the like), ureido group (preferably a ureido group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, for example, an unsubstituted ureido group , Methylureido group, phenylureido group, etc.), phosphoric acid amide group (preferably having 1 to 20 carbon atoms, more preferably having 1 to 16 carbon atoms, particularly preferably having 1 to 12 carbon atoms). Yes, for example, diethyl phosphoric acid amide group, phenyl phosphoric acid amide group, etc.), hydroxy group, mercapto group, halogen atom (for example, fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, Carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, heterocyclic group (preferably having a carbon number of 1 to 0, more preferably a heterocyclic group of 1 to 12, for example, a heterocyclic group having a heteroatom such as a nitrogen atom, an oxygen atom, a sulfur atom, such as an imidazolyl group, a pyridyl group, a quinolyl group, a furyl group , Piperidyl group, morpholino group, benzoxazolyl group, benzimidazolyl group, benzthiazolyl group and the like), silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably A silyl group having 3 to 24 carbon atoms, and examples thereof include a trimethylsilyl group and a triphenylsilyl group). These substituents may be further substituted with these substituents. Moreover, when it has two or more substituents, they may be the same or different. If possible, they may be bonded to each other to form a ring.

R ¹ , R ² and R ³ are each independently a hydrogen atom, an alkyl group, a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), or a group represented by -LQ described later. It is preferably a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a chlorine atom, or a group represented by -LQ, more preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Particularly preferred are a hydrogen atom and an alkyl group having 1 to 2 carbon atoms. Specific examples of the alkyl group include methyl group, ethyl group, n-propyl group, n-butyl group, sec-butyl group and the like. The alkyl group may have a suitable substituent. Examples of the substituent include a halogen atom, aryl group, heterocyclic group, alkoxyl group, aryloxy group, alkylthio group, arylthio group, acyl group, hydroxyl group, acyloxy group, amino group, alkoxycarbonyl group, acylamino group, oxycarbonyl Group, carbamoyl group, sulfonyl group, sulfamoyl group, sulfonamido group, sulfolyl group, carboxyl group and the like. The carbon number of the alkyl group does not include the carbon atom of the substituent. The same applies to the carbon number of other groups.

L represents a divalent linking group selected from the above linking group group, or a divalent linking group formed by combining two or more thereof. In the linking group group, R ^{4 in} —NR ⁴ — represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group, preferably a hydrogen atom or an alkyl group. R ⁵ in —PO (OR ⁵ ) — represents an alkyl group, an aryl group or an aralkyl group, and preferably an alkyl group. When R ⁴ and R ⁵ represent an alkyl group, an aryl group or an aralkyl group, the preferred range of the carbon number is the same as that described in “Substituent group Y”. L preferably contains a single bond, —O—, —CO—, —NR ⁴ —, —S—, —SO ₂ —, an alkylene group or an arylene group, and —CO—, —O—, —NR ⁴ -, and more preferably contains an alkylene group or an arylene group. When L contains an alkylene group, the alkylene group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 6 carbon atoms.
Specific examples of particularly preferred alkylene groups include methylene, ethylene, trimethylene, tetrabutylene, hexamethylene groups and the like. When L contains an arylene group, the carbon number of the arylene group is preferably 6 to 24, more preferably 6 to 18, and particularly preferably 6 to 12. Specific examples of particularly preferred arylene groups include phenylene and naphthalene groups. When L contains a divalent linking group (that is, an aralkylene group) obtained by combining an alkylene group and an arylene group, the carbon number of the aralkylene group is preferably 7 to 34, more preferably 7 to 26, and particularly preferably. 7-16. Specific examples of particularly preferred aralkylene groups include a phenylenemethylene group, a phenyleneethylene group, and a methylenephenylene group. The group listed as L may have a suitable substituent. Examples of such a substituent include those similar to the substituents exemplified above as the substituents for R ^{1 to} R ³ .

  Specific examples of L are shown below, but L that can be employed in the present invention is not limited to these specific examples.

  In the formula (1), Q is a carboxyl group, a salt of a carboxyl group (for example, lithium salt, sodium salt, potassium salt, ammonium salt (for example, ammonium, tetramethylammonium, trimethyl-2-hydroxyethylammonium, tetrabutylammonium, trimethyl). Benzylammonium, dimethylphenylammonium, etc.), pyridinium salts, etc.), sulfo groups, salts of sulfo groups (examples of cations forming salts are the same as those described above for carboxyl groups), phosphonoxy groups, salts of phosphonoxy groups (salts) Examples of the cation that forms are the same as those described above for the carboxyl group). A carboxyl group, a sulfo group, and a phospho group are more preferable, and a carboxyl group or a sulfo group is particularly preferable.

  The fluoropolymer may contain one type of repeating unit represented by the general formula (1) or two or more types. Moreover, the said fluorine-type polymer may have 1 type (s) or 2 or more types of repeating units other than said each repeating unit. The other repeating units are not particularly limited, and preferred examples thereof include repeating units derived from ordinary radical polymerizable monomers. Hereinafter, specific examples of monomers for deriving other repeating units will be given. The fluoropolymer may contain a repeating unit derived from one or more monomers selected from the following monomer group.

Monomer group (1) Alkenes ethylene, propylene, 1-butene, isobutene, 1-hexene, 1-dodecene, 1-octadecene, 1-eicosene, hexafluoropropene, vinylidene fluoride, chlorotrifluoroethylene, 3, 3, 3-trifluoropropylene, tetrafluoroethylene, vinyl chloride, vinylidene chloride, etc .;
(2) Dienes 1,3-butadiene, isoprene, 1,3-pentadiene, 2-ethyl-1,3-butadiene, 2-n-propyl-1,3-butadiene, 2,3-dimethyl-1,3 -Butadiene, 2-methyl-1,3-pentadiene, 1-phenyl-1,3-butadiene, 1-α-naphthyl-1,3-butadiene, 1-β-naphthyl-1,3-butadiene, 2-chloro -1,3-butadiene, 1-bromo-1,3-butadiene, 1-chlorobutadiene, 2-fluoro-1,3-butadiene, 2,3-dichloro-1,3-butadiene, 1,1,2- Trichloro-1,3-butadiene and 2-cyano-1,3-butadiene, 1,4-divinylcyclohexane and the like;

(3) Derivatives of α, β-unsaturated carboxylic acid (3a) Alkyl acrylates Methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, tert-butyl acrylate , Amyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, tert-octyl acrylate, dodecyl acrylate, phenyl acrylate, benzyl acrylate, 2-chloroethyl acrylate, 2-bromoethyl acrylate, 4-chlorobutyl acrylate, 2-cyanoethyl acrylate, 2-acetoxyethyl acrylate, methoxybenzyl Chryrate, 2-chlorocyclohexyl acrylate, furfuryl acrylate, tetrahydrofurfuryl acrylate, 2-methoxyethyl acrylate, ω-methoxypolyethylene glycol acrylate (number of added polyoxyethylene: n = 2 to 100), 3-methoxy Butyl acrylate, 2-ethoxyethyl acrylate, 2-butoxyethyl acrylate, 2- (2-butoxyethoxy) ethyl acrylate, 1-bromo-2-methoxyethyl acrylate, 1,1-dichloro-2-ethoxyethyl acrylate, glycidyl acrylate Such);

(3b) Alkyl methacrylates Methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, amyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, 2 -Ethylhexyl methacrylate, n-octyl methacrylate, stearyl methacrylate, benzyl methacrylate, phenyl methacrylate, allyl methacrylate, furfuryl methacrylate, tetrahydrofurfuryl methacrylate, cresyl methacrylate, naphthyl methacrylate, 2-methoxyethyl methacrylate, 3-methoxybutyl methacrylate, ω Methoxypolyethylene glycol methacrylate (number of added polyoxyethylene: n = 2 to 100), 2-acetoxyethyl methacrylate, 2-ethoxyethyl methacrylate, 2-butoxyethyl methacrylate, 2- (2-butoxyethoxy) ethyl methacrylate Glycidyl methacrylate, 3-trimethoxysilylpropyl methacrylate, allyl methacrylate, 2-isocyanatoethyl methacrylate, etc .;

(3c) Diesters of unsaturated polycarboxylic acids Dimethyl maleate, dibutyl maleate, dimethyl itaconate, dibutyl taconate, dibutyl crotonate, dihexyl crotonate, diethyl fumarate, dimethyl fumarate, etc .;

(3d) Amides of α, β-unsaturated carboxylic acids N, N-dimethylacrylamide, N, N-diethylacrylamide, Nn-propylacrylamide, N-tertbutylacrylamide, N-tertoctylmethacrylamide, N- Cyclohexylacrylamide, N-phenylacrylamide, N- (2-acetoacetoxyethyl) acrylamide, N-benzylacrylamide, N-acryloylmorpholine, diacetone acrylamide, N-methylmaleimide and the like;

(4) Unsaturated nitriles Acrylonitrile, methacrylonitrile, etc .;
(5) Styrene and its derivatives Styrene, vinyl toluene, ethyl styrene, p-tert butyl styrene, methyl p-vinyl benzoate, α-methyl styrene, p-chloromethyl styrene, vinyl naphthalene, p-methoxy styrene, p-hydroxy Methyl styrene, p-acetoxy styrene, etc .;
(6) Vinyl esters Vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl benzoate, vinyl salicylate, vinyl chloroacetate, vinyl methoxyacetate, vinyl vinyl acetate, etc .;

(7) Vinyl ethers Methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, tert-butyl vinyl ether, n-pentyl vinyl ether, n-hexyl vinyl ether, n-octyl vinyl ether, n-dodecyl Vinyl ether, n-eicosyl vinyl ether, 2-ethylhexyl vinyl ether, cyclohexyl vinyl ether, fluorobutyl vinyl ether, fluorobutoxyethyl vinyl ether, etc .; and (8) other polymerizable monomers N-vinyl pyrrolidone, methyl vinyl ketone, phenyl vinyl ketone, Methoxyethyl vinyl ketone, 2-vinyl oxazoline, 2-isopropenyl oxazoline, etc.

  In the fluoropolymer, the amount of the fluoroaliphatic group-containing monomer is preferably 5% by mass or more, more preferably 10% by mass or more, and more preferably 30% by mass or more of the total amount of constituent monomers of the polymer. Is more preferable. In the fluoropolymer, the amount of the repeating unit represented by the general formula (1) is preferably 0.5% by mass or more, and 1 to 20% by mass of the total amount of the constituent monomers of the fluoropolymer. Is more preferable, and it is further more preferable that it is 1-10 mass%. Since the above-mentioned mass percentage easily varies in a preferable range depending on the molecular weight of the monomer used, the content of the repeating unit represented by the general formula (1) is expressed by the number of moles of the functional group per unit mass of the polymer. Can be accurately defined. When this notation is used, the preferable amount of the hydrophilic group (Q in the formula (1)) contained in the fluoropolymer is 0.1 mmol / g to 10 mmol / g, and the more preferable amount is 0. .2 mmol / g to 8 mmol / g.

  The fluorine-based polymer used in the present invention preferably has a mass average molecular weight of 1,000,000 or less, more preferably 500,000 or less, and even more preferably 100,000 or less. The mass average molecular weight can be measured as a value in terms of polystyrene (PS) using gel permeation chromatography (GPC).

  The manufacturing method of the said fluorine-type polymer is not specifically limited, It can manufacture by a well-known and usual method. For example, it can be produced by adding a general-purpose radical polymerization initiator to an organic solvent containing the above-described monomer having a fluoroaliphatic group, a monomer having a hydrogen bonding group, and the like, and polymerizing the mixture. Further, in some cases, other addition-polymerizable unsaturated compounds can be further added and produced by the same method as described above. Depending on the polymerizability of each monomer, a dropping polymerization method in which a monomer and an initiator are added dropwise to a reaction vessel is also effective for obtaining a polymer having a uniform composition. For example, a polymerization method such as cationic polymerization, radical polymerization, or anionic polymerization using a vinyl group can be employed, and among these, radical polymerization is particularly preferable because it can be used for general purposes. As the polymerization initiator for radical polymerization, known compounds such as radical thermal polymerization initiators and radical photopolymerization initiators can be used, and it is particularly preferable to use radical thermal polymerization initiators. Here, the radical thermal polymerization initiator is a compound that generates radicals by heating to a decomposition temperature or higher. Examples of such radical thermal polymerization initiators include diacyl peroxide (acetyl peroxide, benzoyl peroxide, etc.), ketone peroxide (methyl ethyl ketone peroxide, cyclohexanone peroxide, etc.), hydroperoxide (hydrogen peroxide, tert. -Butyl hydroxide, cumene hydroperoxide, etc.), dialkyl peroxides (di-tert-butyl peroxide, dicumyl peroxide, dilauroyl peroxide, etc.), peroxyesters (tert-butyl peroxyacetate, tert) -Butyl peroxypivalate, etc.), azo compounds (azobisisobutyronitrile, azobisisovaleronitrile, etc.), persulfates (ammonium persulfate, sodium persulfate) And potassium persulfate) and the like. Such radical thermal polymerization initiators can be used singly or in combination of two or more.

  The radical polymerization method is not particularly limited, and an emulsion polymerization method, a suspension polymerization method, a bulk polymerization method, a solution polymerization method, and the like can be adopted. The solution polymerization, which is a typical radical polymerization method, will be described more specifically. The outlines of other polymerization methods are the same, and details thereof are described, for example, in “Polymer Science Experimental Method” edited by Polymer Society (Tokyo Kagaku Dojin, 1981).

  An organic solvent is used for solution polymerization. These organic solvents can be arbitrarily selected as long as the objects and effects of the present invention are not impaired. These organic solvents are usually organic compounds having boiling points under atmospheric pressure in the range of 50 to 200 ° C., and organic compounds that uniformly dissolve each component are preferred. Examples of preferred organic solvents include alcohols such as isopropanol and butanol; ethers such as dibutyl ether, ethylene glycol dimethyl ether, tetrahydrofuran and dioxane; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; ethyl acetate and acetic acid And esters such as butyl, amyl acetate, and γ-butyrolactone; and aromatic hydrocarbons such as benzene, toluene, and xylene. In addition, these organic solvents can be used individually by 1 type or in combination of 2 or more types. Furthermore, a water-mixed organic solvent in which water is used in combination with the above organic solvent is also applicable from the viewpoint of the solubility of the monomer and the polymer to be produced.

  Also, the solution polymerization conditions are not particularly limited, but for example, it is preferable to heat within a temperature range of 50 to 200 ° C. for 10 minutes to 30 hours. Furthermore, in order not to deactivate the generated radicals, it is preferable to perform an inert gas purge not only during solution polymerization but also before the start of solution polymerization. Usually, nitrogen gas is suitably used as the inert gas.

  In order to obtain the fluoropolymer in a preferable molecular weight range, a radical polymerization method using a chain transfer agent is particularly effective. As chain transfer agents, mercaptans (for example, octyl mercaptan, decyl mercaptan, dodecyl mercaptan, tert-dodecyl mercaptan, octadecyl mercaptan, thiophenol, p-nonylthiophenol, etc.), polyhalogenated alkyls (for example, carbon tetrachloride, chloroform, etc.) , 1,1,1-trichloroethane, 1,1,1-tribromooctane, etc.) and low-activity monomers (α-methylstyrene, α-methylstyrene dimer, etc.) can be used, preferably carbon These are mercaptans of 4-16. The amount of these chain transfer agents used is remarkably influenced by the activity of the chain transfer agent, the combination of the monomers, the polymerization conditions and the like, and must be precisely controlled. It is about 01 mol% to 50 mol%, preferably 0.05 mol% to 30 mol%, particularly preferably 0.08 mol% to 25 mol%. These chain transfer agents may be present in the system simultaneously with the target monomer whose degree of polymerization is to be controlled in the polymerization process, and the addition method is not particularly limited. It may be added after being dissolved in the monomer, or may be added separately from the monomer.

  As described above, the fluorine-based polymer preferably has a polymerizable group as a substituent in order to fix the alignment state of molecules of a liquid crystal compound, particularly a discotic liquid crystal compound.

  Specific examples of the fluoroaliphatic group-containing copolymer preferably used in the present invention as the fluorine-based polymer are shown below, but the present invention is not limited to these specific examples. Here, the numerical values (numerical values such as a, b, c, and d) in the formula are mass percentages indicating the composition ratio of each monomer, and Mw is a mass average molecular weight in terms of PS measured by GPC.

  The preferred range of the content of the fluoropolymer in the composition varies depending on the application, but when used for forming the optically anisotropic layer, the composition (a composition excluding the solvent in the case of a coating solution) Among these, 0.005 to 8% by mass is preferable, 0.01 to 5% by mass is more preferable, and 0.05 to 1% by mass is even more preferable. If the addition amount of the fluorine-based polymer is less than 0.005% by mass, the effect is insufficient, and if it exceeds 8% by mass, the coating film cannot be sufficiently dried, or the performance as an optical film (for example, letter The uniformity of the foundation).

<< Fluorine-containing compound represented by formula (2) >>
Next, the fluorine-containing compound represented by the general formula (2) will be described.
General formula (2)
(R ⁰ ) _m −L ⁰ − (W) _n
In the formula, R ⁰ represents an alkyl group, an alkyl group having a CF ₃ group at the terminal, or an alkyl group having a CF ₂ H group at the terminal, and m represents an integer of 1 or more. A plurality of R ⁰ may be the same or different, but at least one represents an alkyl group having a CF ₃ group or a CF ₂ H group at the terminal.
L ⁰ represents an (m + n) -valent linking group, W represents a carboxyl group (—COOH) or a salt thereof, a sulfo group (—SO ₃ H) or a salt thereof, a sulfato group (—OSO ₃ H) or a salt thereof, or A phosphonoxy group {—OP (═O) (OH) ₂ } or a salt thereof is represented, and n represents an integer of 1 or more.

In Formula (2), R ⁰ functions as a hydrophobic group of the fluorine-containing compound. The alkyl group represented by R ⁰ is a substituted or unsubstituted alkyl group, which may be linear or branched, preferably an alkyl group having 1 to 20 carbon atoms, more preferably Is an alkyl group of 4 to 16, particularly preferably an alkyl group of 6 to 16. As the substituent, any of the substituents exemplified as the substituent group D described later can be applied.

The alkyl group having a CF ₃ group at the terminal represented by R ⁰ preferably has 1 to 20 carbon atoms, more preferably 4 to 16 and particularly preferably 4 to 8. The alkyl group having a CF ₃ group at the terminal is an alkyl group in which part or all of the hydrogen atoms contained in the alkyl group are substituted with fluorine atoms. 50% or more of the hydrogen atoms in the alkyl group are preferably substituted with fluorine atoms, more preferably 60% or more are substituted, and particularly preferably 70% or more are substituted. The remaining hydrogen atoms may be further substituted with the substituents exemplified as the substituent group D described later. The alkyl group having a CF ₂ H group at the terminal represented by R ⁰ preferably has 1 to 20 carbon atoms, more preferably 4 to 16 and particularly preferably 4 to 8. The alkyl group having a CF ₂ H group at the terminal is an alkyl group in which some or all of the hydrogen atoms contained in the alkyl group are substituted with fluorine atoms. 50% or more of hydrogen atoms in the alkyl group are preferably substituted with fluorine atoms, more preferably 60% or more are substituted, and particularly preferably 70% or more are substituted. The remaining hydrogen atoms may be further substituted with the substituents exemplified as the substituent group D described later. Examples of an alkyl group having a CF ₃ group at the terminal represented by R ⁰ or an alkyl group having a CF ₂ H group at the terminal are shown below.

R1: n-C ₈ F _{17-
R2: n-C 6 F 13} -
_{R3: n-C 4 F 9} -
_{R4: n-C 8 F 17} - (CH 2) 2 -
_{R5: n-C 6 F 13} - (CH 2) 2 -
_{R6: n-C 4 F 9} - (CH 2) 2 -
_{R7: H- (CF 2) 8} -
_{R8: H- (CF 2) 6} -
_{R9: H- (CF 2) 4} -
_{R10: H- (CF 2) 8} - (CH 2) -
R11: H— (CF ₂ ) ₆ — (CH ₂ ) —
_{R12: H- (CF 2) 4} - (CH 2) -

In the formula (2), the (m + n) -valent linking group represented by L ⁰ is an alkylene group, an alkenylene group, an aromatic group, a heterocyclic group, —CO—, or —NR— (R has 1 carbon atom. A linking group in which at least two groups selected from the group consisting of —O—, —S—, —SO—, and —SO ₂ — are combined.

In the formula (2), W represents a carboxyl group (—COOH) or a salt thereof, a sulfo group (—SO ₃ H) or a salt thereof, a sulfato group (—OSO ₃ H) or a salt thereof, or a phosphonoxy group {—OP (= O) (OH) ₂ } or a salt thereof. The preferable range of W is the same as Q in the general formula (1).

  Among the fluorine-containing compounds represented by the general formula (2), a compound represented by the following general formula (2a) or a general formula (2b) described later is preferable.

In formula (2a), R ⁵ and R ⁶ each represents an alkyl group, an alkyl group having a CF ₃ group at the terminal, or an alkyl group having a CF ₂ H group at the terminal, wherein R ⁵ and R ⁶ are simultaneously an alkyl group. Never. W ¹ and W ² are each a hydrogen atom, a carboxyl group (—COOH) or a salt thereof, a sulfo group (—SO ₃ H) or a salt thereof, a sulfato group (—OSO ₃ H) or a salt thereof, a phosphonoxy group {—OP ( ═O) (OH) ₂ } or a salt thereof, or an alkyl group, an alkoxy group or an alkylamino group having a carboxyl group, a sulfo group, a sulfato group or a phosphonoxy group as a substituent, wherein W ¹ and W ² are simultaneously It is not a hydrogen atom.

R ⁵ and R ⁶ have the same meaning as R ⁰ in the general formula (2), and their preferred ranges are also the same. Carboxyl group (—COOH) or a salt thereof represented by W ¹ and W ² , sulfo group (—SO ₃ H) or a salt thereof, sulfato group (—OSO ₃ H) or a salt thereof, phosphonoxy group {—OP (= O) (OH) ₂ } or a salt thereof is synonymous with W in the general formula (2), and its preferred range is also the same. The alkyl group having a carboxyl group, a sulfo group, a sulfato group or a phosphonoxy group as a substituent represented by W ¹ and W ² may be linear or branched, and preferably has 1 carbon atom. -20 alkyl groups, more preferably 1-8 alkyl groups, and particularly preferably 1-3 alkyl groups. The alkyl group having a carboxyl group, a sulfo group, a sulfato group, or a phosphonoxy group as the substituent may have at least one carboxyl group, sulfo group, sulfato group, or phosphonoxy group. The group and the phosphonoxy group are synonymous with the carboxyl group, the sulfo group, the sulfato group, and the phosphonoxy group represented by W in the general formula (2), and the preferred range is also the same. The alkyl group having a carboxyl group, a sulfo group, a sulfato group or a phosphonoxy group as the substituent may be substituted with a substituent other than this, and the substituent is exemplified as the substituent group D described later. Either of these can be applied. The alkoxy group having a carboxyl group, a sulfo group, a sulfato group or a phosphonoxy group as a substituent represented by W ¹ and W ² may be linear or branched, and preferably has 1 carbon atom. -20 alkoxy groups, more preferably 1-8 alkoxy groups, and particularly preferably 1-4 alkoxy groups. The alkoxy group having a carboxyl group, a sulfo group, a sulfato group or a phosphonoxy group as the substituent may have at least one carboxyl group, sulfo group, sulfato group or phosphonoxy group. The group and the phosphonoxy group are synonymous with the carboxyl group, the sulfo group, the sulfato group, and the phosphonoxy group represented by W in the general formula (2), and the preferred range is also the same. The alkoxy group having a carboxyl group, a sulfo group, a sulfato group, or a phosphonoxy group may be substituted with a substituent other than this, and the substituent is any of the substituents exemplified as Substituent Group D described later. Can be applied. The alkylamino group having a carboxyl group, a sulfo group, a sulfato group or a phosphonoxy group as a substituent represented by W ¹ and W ² may be linear or branched, and preferably has a carbon number. 1 to 20 alkylamino groups, more preferably 1 to 8 alkylamino groups, and particularly preferably 1 to 4 alkylamino groups. The alkylamino group having a carboxyl group, a sulfo group, a sulfato group, or a phosphonoxy group may have at least one carboxyl group, sulfo group, sulfato group, or phosphonoxy group, such as a carboxyl group, a sulfo group, a sulfato group, and The phosphonoxy group is synonymous with the carboxyl group, sulfo group, sulfato group and phosphonoxy group represented by W in the general formula (2), and the preferred range is also the same. The alkylamino group having a carboxyl group, a sulfo group, a sulfato group, or a phosphonoxy group may be substituted with other substituents, and any of the substituents exemplified as Substituent Group D described later can be used as the substituent. Can apply.

W ¹ and W ² are particularly preferably each a hydrogen atom or (CH ₂ ) _n SO ₃ M (n represents 0 or 1). M represents a cation, but M may not be present when the charge is 0 in the molecule. As cations represented by M, for example, protonium ions, alkali metal ions (lithium ions, sodium ions, potassium ions, etc.), alkaline earth metal ions (barium ions, calcium ions, etc.), ammonium ions and the like are preferably applied. . Of these, proton ions, lithium ions, sodium ions, potassium ions, and ammonium ions are particularly preferable.

Next, the following general formula (2b) will be described.
General formula (2b)
(R ⁷ -L ^1- ) _m2 (Ar ¹ ) -W ³
In the formula (2b), R ⁷ represents an alkyl group, an alkyl group having a CF ₃ group at the terminal, or an alkyl group having a CF ₂ H group at the terminal, m2 represents an integer of 1 or more, and a plurality of R ⁷ May be the same or different, but at least one represents an alkyl group having a CF ₃ group or a CF ₂ H group at the terminal. L ¹ is an alkylene group, an aromatic group, —CO—, —NR— (R is an alkyl group having 1 to 5 carbon atoms or a hydrogen atom), —O—, —S—, —SO—, —SO. _2- represents a divalent linking group selected from the group consisting of a combination thereof, and a plurality of L ¹ may be the same or different. Ar ¹ represents an aromatic hydrocarbon ring or an aromatic heterocycle, W ³ represents a carboxyl group (—COOH) or a salt thereof, a sulfo group (—SO ₃ H) or a salt thereof, a sulfato group (—OSO ₃ H) or A salt thereof, a phosphonoxy group {—OP (═O) (OH) ₂ } or a salt thereof, or an alkyl group, an alkoxy group, or an alkylamino group having a carboxyl group, a sulfo group, a sulfato group, or a phosphonoxy group as a substituent. .

R ⁷ has the same meaning as R ⁰ in formula (2), and its preferred range is also the same. L ¹ is preferably an alkylene group having 1 to 12 carbon atoms, an aromatic group having 6 to 12 carbon atoms, —CO—, —NR—, —O—, —S—, —SO—, —SO ₂ — and Represents a linking group having a total carbon number of 0 to 40 consisting of a combination thereof, particularly preferably an alkylene group having 1 to 8 carbon atoms, a phenyl group, —CO—, —NR—, —O—, —S—, —SO. ₂ represents a linking group having 0 to 20 carbon atoms and a combination thereof. Ar ¹ preferably represents an aromatic hydrocarbon ring having 6 to 12 carbon atoms, particularly preferably a benzene ring or a naphthalene ring. Carboxyl group represented by W ³ (—COOH) or a salt thereof, sulfo group (—SO ₃ H) or a salt thereof, sulfato group (—OSO ₃ H) or a salt thereof, phosphonoxy group {—OP (═O) ( OH) ₂ } or a salt thereof, or an alkyl group, an alkoxy group, or an alkylamino group having a carboxyl group, a sulfo group, a sulfato group, or a phosphonoxy group as a substituent, as W ¹ and W ² in the general formula (2a). Carboxyl group (—COOH) or a salt thereof, sulfo group (—SO ₃ H) or a salt thereof, sulfato group (—OSO ₃ H) or a salt thereof, phosphonoxy group {—OP (═O) (OH) ₂ } Or a salt thereof, an alkyl group having a carboxyl group, a sulfo group, a sulfato group or a phosphonoxy group as a substituent, an alkoxy group Group, or has the same meaning as the alkylamino group and the preferable ranges thereof are the same.

W ³ is preferably a carboxyl group (—COOH) or a salt thereof, a sulfo group (—SO ₃ H) or a salt thereof, or a carboxyl group (—COOH) or a salt thereof or a sulfo group (—SO ₃ H) as a substituent. Alternatively, it is an alkylamino group having a salt thereof, and particularly preferably SO ₃ M or CO ₂ M. M represents a cation, but M may not be present when the charge is 0 in the molecule. As cations represented by M, for example, protonium ions, alkali metal ions (lithium ions, sodium ions, potassium ions, etc.), alkaline earth metal ions (barium ions, calcium ions, etc.), ammonium ions and the like are preferably applied. . Of these, proton ions, lithium ions, sodium ions, potassium ions, and ammonium ions are particularly preferable.

  In the present specification, the substituent group D includes an alkyl group (preferably an alkyl group having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, and particularly preferably 1 to 8 carbon atoms, such as a methyl group. , Ethyl group, isopropyl group, tert-butyl group, n-octyl group, n-decyl group, n-hexadecyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, etc.), alkenyl group (preferably having 2 carbon atoms) -20, more preferably an alkenyl group having 2 to 12 carbon atoms, particularly preferably 2 to 8 carbon atoms, and examples thereof include a vinyl group, an allyl group, a 2-butenyl group, and a 3-pentenyl group), alkynyl A group (preferably an alkynyl group having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, particularly preferably 2 to 8 carbon atoms, And aryl groups (preferably having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, and particularly preferably 6 to 12 carbon atoms). For example, phenyl Group, p-methylphenyl group, naphthyl group and the like), substituted or unsubstituted amino group (preferably having 0 to 20 carbon atoms, more preferably 0 to 10 carbon atoms, and particularly preferably 0 to 6 carbon atoms). An amino group, for example, an unsubstituted amino group, a methylamino group, a dimethylamino group, a diethylamino group, a dibenzylamino group and the like),

An alkoxy group (preferably an alkoxy group having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, and a butoxy group). An aryloxy group (preferably an aryloxy group having 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, and examples thereof include a phenyloxy group and a 2-naphthyloxy group. An acyl group (preferably having a carbon number of 1-20, more preferably a carbon number of 1-16, particularly preferably a carbon number of 1-12, such as an acetyl group, a benzoyl group, a formyl group, a pivaloyl group, etc. An alkoxycarbonyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, and particularly preferably 2 to 2 carbon atoms). 2 alkoxycarbonyl groups, for example, methoxycarbonyl group, ethoxycarbonyl group and the like, and aryloxycarbonyl groups (preferably having 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, and particularly preferably carbon numbers). An aryloxycarbonyl group having 7 to 10 carbon atoms, such as a phenyloxycarbonyl group, an acyloxy group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, and particularly preferably 2 to 2 carbon atoms). 10 acyloxy groups such as an acetoxy group and a benzoyloxy group)

An acylamino group (preferably an acylamino group having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms, such as an acetylamino group and a benzoylamino group), alkoxycarbonyl An amino group (preferably an alkoxycarbonylamino group having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as a methoxycarbonylamino group), aryloxy Carbonylamino group (preferably an aryloxycarbonylamino group having 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as a phenyloxycarbonylamino group) Sulfonylamino group (preferably having 1 to 20 carbon atoms, more preferred Or a sulfonylamino group having 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include a methanesulfonylamino group and a benzenesulfonylamino group, and a sulfamoyl group (preferably having a carbon number of 0 to 20). More preferably, it is a sulfamoyl group having 0 to 16 carbon atoms, particularly preferably 0 to 12 carbon atoms, and examples thereof include a sulfamoyl group, a methylsulfamoyl group, a dimethylsulfamoyl group, and a phenylsulfamoyl group. ), A carbamoyl group (preferably a carbamoyl group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 12 carbon atoms. For example, an unsubstituted carbamoyl group, a methylcarbamoyl group, diethylcarbamoyl group Group, phenylcarbamoyl group, etc.),

An alkylthio group (preferably an alkylthio group having 1 to 20 carbon atoms, more preferably an alkylthio group having 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as a methylthio group and an ethylthio group), an arylthio group ( Preferably it is C6-C20, More preferably, it is C6-C16, Most preferably, it is C6-C12 arylthio group, for example, a phenylthio group etc. are mentioned, A sulfonyl group (preferably C1-C1). 20, more preferably a sulfonyl group having 1 to 16 carbon atoms, particularly preferably a sulfonyl group having 1 to 12 carbon atoms, such as a mesyl group and a tosyl group, and a sulfinyl group (preferably having a carbon number of 1 to 20, more A sulfinyl group having 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms is preferable. Zensulfinyl group and the like), ureido group (preferably a ureido group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, for example, an unsubstituted ureido group , Methylureido group, phenylureido group, etc.), phosphoric acid amide group (preferably having 1 to 20 carbon atoms, more preferably having 1 to 16 carbon atoms, particularly preferably having 1 to 12 carbon atoms). Yes, for example, diethyl phosphoric acid amide group, phenyl phosphoric acid amide group, etc.), hydroxy group, mercapto group, halogen atom (for example, fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, Carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, heterocyclic group (preferably having a carbon number of 1 to 0, more preferably a heterocyclic group of 1 to 12, for example, a heterocyclic group having a heteroatom such as a nitrogen atom, an oxygen atom, a sulfur atom, such as an imidazolyl group, a pyridyl group, a quinolyl group, a furyl group , Piperidyl group, morpholino group, benzoxazolyl group, benzimidazolyl group, benzthiazolyl group and the like), silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably A silyl group having 3 to 24 carbon atoms, and examples thereof include a trimethylsilyl group and a triphenylsilyl group). These substituents may be further substituted with these substituents. Further, when two or more substituents are present, they may be the same or different. If possible, they may be bonded to each other to form a ring.

  In addition, the said fluorine-containing compound has a polymeric group as a substituent in order to fix the orientation state of the molecule | numerator of a liquid crystalline compound, especially a discotic liquid crystalline compound.

  Specific examples of the fluorine-containing compound represented by the general formula (2) that can be used in the present invention are shown below, but the fluorine-containing compound used in the present invention is not limited thereto. In the following specific examples, no. IV-1 to 42 are general formula (2a), No. IV-43 to 66 are examples of the compound represented by the general formula (2b).

[Alignment film]
In the anisotropic layer of the present invention, the alignment film is made of at least one kind of polymer and has a function of defining the alignment direction of the rod-like liquid crystalline molecules. The alignment film can improve the uniformity of the alignment of the liquid crystalline composition or improve the adhesion between the polymer substrate and the optically anisotropic layer. Further, if the alignment state of the rod-like liquid crystal compound is fixed after the alignment, the alignment film plays the role and can be removed. That is, it is possible to produce a polarizing plate having an optically anisotropic layer by transferring only the optically anisotropic layer on the alignment film in which the alignment state is fixed onto the polarizer.

  The alignment film is an organic compound (eg, ω-tricosanoic acid) formed by rubbing treatment of an organic compound (preferably a polymer), oblique deposition of an inorganic compound, formation of a layer having a microgroove, or Langmuir-Blodgett method (LB film). , Dioctadecylmethylammonium chloride, methyl stearylate). Furthermore, an alignment film in which an alignment function is generated by application of an electric field, application of a magnetic field, or light irradiation is also known.

The alignment film can be rubbed if necessary. The polymer used for the alignment film (hereinafter sometimes referred to as “alignment film polymer”) preferably has a molecular structure having a function of aligning liquid crystalline molecules. In the present invention, in addition to the function of aligning the liquid crystal molecules, the polymer constituting the alignment film is bonded with a side chain having a crosslinkable functional group (eg, a double bond) to the main chain, or has a liquid crystallinity. It is preferable to introduce a crosslinkable functional group having a function of orienting molecules into the side chain.
As the polymer used for the alignment film, either a polymer that can be crosslinked by itself or a polymer that is crosslinked by a crosslinking agent can be used, and a plurality of combinations thereof can be used.

Examples of the alignment film polymer include, for example, a methacrylate polymer, a styrene polymer, a polyolefin, a polyvinyl alcohol, a modified polyvinyl alcohol, and a poly (N--) described in paragraph No. [0022] of JP-A-8-338913. Methylolacrylamide), polyester, polyimide, vinyl acetate polymer, carboxymethylcellulose, polycarbonate and the like. Moreover, a silane coupling agent can be used as a polymer.
The alignment film polymer is preferably a water-soluble polymer (eg, poly (N-methylolacrylamide), carboxymethylcellulose, gelatin, polyvinyl alcohol, modified polyvinyl alcohol), more preferably gelatin, polyvinyl alcohol, and modified polyvinyl alcohol, and polyvinyl alcohol. And modified polyvinyl alcohol is most preferred. Further, it is particularly preferable to use two types of polyvinyl alcohol or modified polyvinyl alcohol having different degrees of polymerization. In the present application, polyvinyl alcohol and modified polyvinyl alcohol are collectively referred to as polyvinyl alcohol derivatives.

  The saponification degree of the polyvinyl alcohol is preferably 70 to 100%, more preferably 80 to 100%. Moreover, it is preferable that the average degree of polymerization of the said polyvinyl alcohol is 100-5000.

The side chain having the function of aligning the liquid crystalline molecules described above generally has a hydrophobic group as a functional group. The specific type of functional group can be determined according to the type of liquid crystal molecule and the required alignment state.
For example, the modifying group of the modified polyvinyl alcohol can be introduced by copolymerization modification, chain transfer modification or block polymerization modification. Examples of modifying groups 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, fluorine atoms Examples include substituted hydrocarbon groups, thioether groups, polymerizable groups (unsaturated polymerizable groups, epoxy groups, azirinidyl groups, etc.), alkoxysilyl groups (trialkoxy, dialkoxy, monoalkoxy), and the like. As specific examples of these modified polyvinyl alcohol compounds, for example, paragraph numbers [0022] to [0145] in JP-A No. 2000-155216 and paragraph numbers [0018] to [0018] in JP-A No. 2002-62426 are described. [0022] and the like.

When a side chain having a crosslinkable functional group is bonded to the main chain of the alignment film polymer or a crosslinkable functional group is introduced into a side chain having a function of aligning liquid crystal molecules, the alignment film polymer and the polyfunctional monomer are introduced. Can 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 is firmly bonded by a covalent bond. Therefore, the strength of the optical compensation sheet can be remarkably improved by introducing the crosslinkable functional group into the alignment film polymer.
The crosslinkable functional group of the alignment film polymer preferably contains a polymerizable group in the same manner as the polyfunctional monomer. Specific examples include those described in paragraphs [0080] to [0100] in JP-A-2000-155216.

The alignment film polymer can be cross-linked using a cross-linking agent separately from the cross-linkable functional group.
Examples of the crosslinking agent include aldehydes, N-methylol compounds, dioxane derivatives, compounds that act by activating carboxyl groups, active vinyl compounds, active halogen compounds, isoxazole and dialdehyde starch. Two or more kinds of crosslinking agents may be used in combination. Specific examples include compounds described in paragraphs [0023] to [0024] in JP-A-2002-62426. Aldehydes having high reaction activity, particularly glutaraldehyde are preferred.

  0.1-20 mass% is preferable with respect to alignment film polymer, and, as for the addition amount of the said crosslinking agent, 0.5-15 mass% is more preferable. The amount of the unreacted crosslinking agent remaining in the alignment film is preferably 1.0% by mass or less, and more preferably 0.5% by mass or less. By adjusting in this way, even if the alignment film is used in a liquid crystal display device for a long period of time or left in a high temperature and high humidity atmosphere for a long period of time, sufficient durability without occurrence of reticulation can be obtained.

  The alignment film is basically formed by applying the polymer, which is an alignment film forming material, on a transparent support containing a crosslinking agent, followed by drying by heating (crosslinking) and, if necessary, rubbing treatment. be able to. As described above, the crosslinking reaction can be carried out at any time after coating on the transparent support. When a water-soluble polymer such as polyvinyl alcohol is used as the alignment film forming material, the coating solution is preferably a mixed solvent of an organic solvent (eg, methanol) having a defoaming action and water. The ratio by mass is water: methanol greater than 0 and 99 or less: less than 100, preferably 1 or more, and more preferably greater than 0 and 91 or less: less than 100, 9 or more. Thereby, generation | occurrence | production of a bubble is suppressed and the defect of the layer surface of an orientation film and also an optically anisotropic layer reduces remarkably.

  The alignment film is preferably applied by spin coating, dip coating, curtain coating, extrusion coating, rod coating, or roll coating. A rod coating method is particularly preferable. Moreover, as for the film thickness after drying of a hardened film, 0.1-10 micrometers is preferable. Heating and drying can be performed at 20 ° C to 110 ° C. In order to form sufficient cross-linking, 60 ° C to 100 ° C is preferable, and 80 ° C to 100 ° C is particularly preferable. The drying time can be 1 minute to 36 hours, preferably 1 minute to 30 minutes. The pH is preferably set to an optimum value for the crosslinking agent to be used. When glutaraldehyde is used, the pH is 4.5 to 5.5, and 5 is particularly preferable.

  The alignment film is provided on the transparent support or the undercoat layer. The alignment film can be obtained by cross-linking the polymer layer as described above and, if necessary, rubbing the surface.

  For the rubbing treatment, a treatment method widely adopted as a liquid crystal alignment treatment process of LCD can be applied. That is, a method of obtaining the orientation by rubbing the surface of the orientation film in a certain direction using paper, gauze, felt, rubber, nylon, polyester fiber or the like can be used. Generally, it is carried out by rubbing several times using a cloth or the like in which fibers having a uniform length and thickness are planted on average.

  Next, the alignment film functions to align the liquid crystalline molecules of the optically anisotropic layer provided on the alignment film. Thereafter, as 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.

[Preparation of retardation film]
The retardation film of the present invention can be prepared, for example, by applying a coating solution and drying it.
(solvent)
An organic solvent is preferably used as a solvent used for preparing the coating liquid such as the liquid crystal composition. Examples of the organic solvent include amide (eg, N, N-dimethylformamide), sulfoxide (eg, dimethyl sulfoxide), heterocyclic compound (eg, pyridine), hydrocarbon (eg, benzene, hexane), alkyl halide ( Examples, chloroform, dichloromethane), esters (eg, methyl acetate, butyl acetate), ketones (eg, acetone, methyl ethyl ketone), ethers (eg, tetrahydrofuran, 1,2-dimethoxyethane) are included. Alkyl halides and ketones are preferred. Two or more organic solvents may be used in combination. The coating liquid can be applied by a known method (eg, extrusion coating method, direct gravure coating method, reverse gravure coating method, die coating method).

(Other materials)
Along with the rod-like liquid crystalline compound, a plasticizer, a surfactant, a polymerizable monomer, etc. can be used in combination to improve the uniformity of the coating film, the strength of the film, the orientation of the rod-like liquid crystalline compound, and the like. These materials are preferably compatible with the rod-like liquid crystalline compound and do not inhibit the alignment.

  Examples of the polymerizable monomer include radically polymerizable or cationically polymerizable compounds. Preferably, it is a polyfunctional radically polymerizable monomer and is preferably copolymerizable with the above-mentioned polymerizable group-containing rod-like liquid crystal compound. Examples thereof include those described in paragraph numbers [0018] to [0020] in JP-A No. 2002-296423. The amount of the compound added is generally in the range of 1 to 50% by mass and preferably in the range of 5 to 30% by mass with respect to the discotic liquid crystalline molecules.

  Examples of the surfactant include conventionally known compounds, and fluorine compounds are particularly preferable. Specific examples include compounds described in paragraph numbers [0028] to [0056] in JP-A-2001-330725.

[Support]
In the present invention, a retardation film formed from a rod-like liquid crystal compound may be formed on a support. The support is preferably transparent. Specifically, the support is preferably a transparent support having a light transmittance of 80% or more.
The support preferably has a small wavelength dispersion, and specifically, the ratio of Re (400) / Re (700) is preferably less than 1.2. Among these, a polymer film is preferable as the transparent support. The transparent support can also serve as the first retardation film, the second retardation film, or the polarizing plate protective film. The entire transparent support and the retardation film may constitute the first retardation film or the second retardation film. The support preferably has a small optical anisotropy, and the in-plane retardation (Re) is preferably 20 nm or less, more preferably 10 nm or less, and most preferably 5 nm or less. When the transparent support also serves as the first retardation film, the retardation (Re) is 20 nm to 150 nm, more preferably 40 nm to 115 nm, and further preferably 60 nm to 95 nm. Similarly, Nz is 1.5-7, more preferably 2.0-5.5, and even more preferably 2.5-4.5.

  Examples of the polymer film as the support include cellulose ester, polycarbonate, polysulfone, polyethersulfone, polyacrylate, and polymethacrylate films. Among these, a cellulose ester film is preferable, an acetyl cellulose film is more preferable, and a triacetyl cellulose film is most preferable. The polymer film is preferably formed by a solvent cast method. In general, the thickness of the transparent support is preferably 20 to 500 μm, and more preferably 40 to 200 μm. In addition, in order to improve the adhesion between the transparent support and the layer (adhesive layer, vertical alignment film or retardation layer) provided thereon, surface treatment (eg, glow discharge treatment, corona discharge treatment, ultraviolet ray) is applied to the transparent support. (UV) treatment, flame treatment) may be performed. Further, an adhesive layer (undercoat layer) may be provided on the transparent support. In addition, the transparent support or the long transparent support has an average particle size of 10 to 10 in order to give slippage in the transport process or to prevent sticking between the back surface and the surface after winding. It is preferable to use a polymer layer in which inorganic particles of about 100 nm are mixed at a solid content mass ratio of 5% to 40% and formed on one side of the support by coating or co-casting with the support.

[Polarizing film and protective film for polarizing film]
The retardation film of the present invention is preferably used in the production of an actual liquid crystal display element after bonding a linearly polarizing film or a protective film for a polarizing film. The polarizing film and the protective film for the polarizing film will be described below.
Examples of the polarizing film include an iodine polarizing film, a dye polarizing film using a dichroic dye, and a polyene polarizing film. The iodine polarizing film and the dye polarizing film are generally produced using a polyvinyl alcohol film. The transmission axis of the polarizing film corresponds to a direction perpendicular to the stretching direction of the film. When a discotic liquid crystalline compound is used for the optically anisotropic layer, the transmission axis of the polarizing film is arranged so as to be substantially parallel to the surface of the discotic liquid crystalline molecule on the alignment film side. . When a rod-like liquid crystal compound is used, the transmission axis of the polarizing film is arranged so as to be substantially parallel to the major axis direction (slow axis) of the rod-like liquid crystal molecule. Usually, it is preferable to bond to the side of the support on which the retardation film is formed, but if necessary, it may be bonded to the optically anisotropic layer side.

It is preferable to use a transparent polymer film as a transparent protective film on the optically anisotropic layer side of the retardation plate. That the protective film is transparent means that the light transmittance is 80% or more. As the transparent protective film, generally a cellulose ester film, preferably a triacetyl cellulose film is used. The cellulose ester film is preferably formed by a solvent cast method. The thickness of the transparent protective film is preferably 20 to 500 μm, and more preferably 50 to 200 μm. The protective film preferably has a small retardation based on birefringence. Specifically, the in-plane retardation (Re) is preferably 0 to 30 nm, more preferably 0 to 15 nm, and most preferably 0 to 5 nm. Further, the thickness direction retardation (Rth) is preferably 0 to 40 nm, more preferably 0 to 20 nm, and most preferably 0 to 10 nm. A film having this property can be suitably used as a transparent protective film, but a cellulose acylate or norbornene film is more preferable from the viewpoint of durability of the polarizing film. As a method for reducing the Rth of the cellulose acylate film, a method described in JP-A-11-246704, JP-A-2001-247717, JP-A-2003-379975 (Japanese Patent Application No. 2003-379975). Etc. Rth can also be reduced by reducing the thickness of the cellulose acylate film.
The thickness of the cellulose sylate film as the transparent protective film for the first and second polarizing films is preferably 10 to 100 μm, more preferably 10 to 60 μm, and still more preferably 20 to 45 μm.

  The features of the present invention will be described more specifically with reference to examples and comparative examples. In addition, materials, amounts used, ratios, processing contents, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

[Example 1]
<Preparation of IPS mode liquid crystal cell 1>
As shown in FIG. 1, electrodes (2 and 3 in FIG. 1) are arranged on one glass substrate so that the distance between adjacent electrodes is 20 μm, and a polyimide film is used as an alignment film on the electrodes. A rubbing process was performed. The rubbing process was performed in the direction 4 shown in FIG. A polyimide film was provided on one surface of a separately prepared glass substrate, and a rubbing treatment was performed to obtain an alignment film. The two glass substrates are stacked and bonded so that the alignment films face each other, the distance between the substrates (gap; d) is 3.9 μm, and the rubbing directions of the two glass substrates are parallel. A nematic liquid crystal composition having a refractive index anisotropy (Δn) of 0.0769 and a dielectric anisotropy (Δε) of 4.5 was enclosed. The value of d · Δn of the liquid crystal layer was 300 nm.

<Preparation of the first retardation film 1>
A cellulose acetate solution having the following composition was put into a mixing tank and stirred while heating to dissolve each component to prepare a cellulose acetate solution. The solution was filtered at 5 kg / cm ² or less using a filter paper (No. 63, manufactured by Advantech) having a retained particle diameter of 4 μm and a drainage time of 35 seconds.

[Cellulose acetate solution composition]
-100 parts by weight of cellulose acetate having an acetylation degree of 60.9% (polymerization degree 300, Mn / Mw = 1.5)
-Triphenyl phosphate (plasticizer) 7.8 parts by mass-Biphenyl diphenyl phosphate (plasticizer) 3.9 parts by mass-Methylene chloride (first solvent) 300 parts by mass-Methanol (second solvent) 54 parts by mass-1- 11 parts by weight of butanol (third solvent)

  In another mixing tank, 8 parts by mass of the following retardation increasing agent A, 10 parts by mass of the following retardation 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 was added and stirred while heating to prepare a retardation increasing agent solution (also serving as a fine particle dispersion). The dope was prepared by mixing 474 parts by mass of the cellulose acetate solution with 40 parts by mass of the retardation increasing agent solution and stirring sufficiently.

  The obtained dope was cast using a band casting machine. A film having a residual solvent amount of 15% by mass was stretched transversely at a stretch ratio of 20% using a tenter under the conditions of 130 ° C., held at 50 ° C. for 30 seconds with the stretched width, and then clipped to remove cellulose. An acetate film was prepared. The residual solvent amount at the end of stretching was 5% by mass, and further dried to prepare a film with the residual solvent amount being less than 0.1% by mass.

  The film thus obtained (first retardation film 1) had a thickness of 80 μm. About the produced 1st phase difference film 1, Re is 70 nm by measuring the light incident angle dependence of Re using an automatic birefringence meter (KOBRA-21ADH, Oji Scientific Instruments Co., Ltd. product). It was found that Rth was 175 nm and Nz was 3.0.

<Preparation of Second Retardation Film 1>
The surface of the manufactured first retardation film 1 was subjected to saponification treatment, and an alignment film coating solution having the following composition was coated on the film with a wire bar coater so as to be 20 ml / m ² . The film was formed by drying with warm air of 60 ° C. for 60 seconds and further with warm air of 100 ° C. for 120 seconds. Next, the formed film was rubbed in a direction parallel to the slow axis direction of the film to obtain an alignment film.

[Composition of alignment film coating solution]
・ Denatured polyvinyl alcohol (AL-1) 10 parts by mass, water 371 parts by mass, methanol 119 parts by mass, glutaraldehyde 0.5 part by mass

  Next, 3.8 g of the following rod-like liquid crystal compound A, 0.06 g of a photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy), 0.02 g of a sensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.), in the present invention A solution in which 0.076 g of a boronic acid compound (specific example (I-30) described above) and 0.002 g of the air interface side vertical alignment agent below were dissolved in 9.2 g of methyl ethyl ketone was prepared. This solution was applied to the alignment film side of the film on which the alignment film was formed with a # 4.5 wire bar. This was affixed to a metal frame and heated in a constant temperature bath at 100 ° C. for 2 minutes to align the rod-like liquid crystal compound. Next, UV irradiation is performed at 80 ° C. with a 120 W / cm high-pressure mercury lamp for 20 seconds to crosslink the rod-like liquid crystal compound, and then it is allowed to cool to room temperature to form an optically anisotropic layer on the first retardation film. A retardation film 1 on which a second retardation film was formed was obtained.

Using an automatic birefringence meter (KOBRA-21ADH, manufactured by Oji Scientific Instruments Co., Ltd.), measuring the light incident angle dependency of Re of the manufactured film, and subtracting the pre-measured contribution of the support When the optical characteristics of only the second retardation film were calculated, it was confirmed that the second retardation film 1 had Re of 0 nm and Rth of −220 nm, and the rod-like liquid crystal was aligned substantially vertically.
The second retardation film 1 thus produced is observed under a polarizing microscope, the alignment state and alignment defects are evaluated, and the number of alignment defects generated in the optically anisotropic layer is observed with an optical microscope. After analysis, (average of 1.0 mm ² range) number of point defects was three in 1.0 mm ² range.
Furthermore, as an evaluation of adhesion, a commercially available tape (PET) was attached to the surface, and the state after peeling off after 30 seconds was observed. As evaluation criteria,
A: Not peeled off at all
B: 1-10% peel off
C: 10-30% or more peeled
D: 30-50% or more peeled off
E: 50% or more peeled off
As a result of the evaluation in the three stages, the adhesion of the second retardation film 1 was B level.

<Production of Polarizing Plate Protective Film 1>
The following composition was put into a mixing tank, stirred while heating to dissolve each component, and a cellulose acetate solution A was prepared.

[Composition of cellulose acetate solution A]
Cellulose acetate with a substitution degree of 2.86 100 parts by mass Triphenyl phosphate (plasticizer) 7.8 parts by mass Biphenyldiphenyl phosphate (plasticizer) 3.9 parts by mass Methylene chloride (first solvent) 300 parts by mass Methanol (second solvent) 54 parts by mass 1-butanol 11 parts by mass

  The following composition was charged into another mixing tank, stirred while heating to dissolve each component, and an additive solution B-1 was prepared.

[Composition of additive solution B-1]
・ Methylene chloride 80 parts by mass ・ Methanol 20 parts by mass ・ The following optical anisotropy reducing agent 40 parts by mass

40 parts by mass of additive solution B-1 was added to 477 parts by mass of cellulose acetate solution A, and the dope was prepared by sufficiently stirring. The dope was cast from a casting port onto a drum cooled to 0 ° C. The film is peeled off in a state where the solvent content is 70% by mass, both ends in the width direction of the film are fixed with a pin tenter (the pin tenter described in FIG. 3 of JP-A-4-1009), and the solvent content is 3-5% by mass. In this state, the film was dried while maintaining an interval at which the stretching ratio in the transverse direction (direction perpendicular to the machine direction) was 3%. Then, it further dried by conveying between the rolls of the heat processing apparatus, and produced the polarizing plate protective film 1 with a thickness of 80 μm.
Using an automatic birefringence meter (KOBRA-21ADH, manufactured by Oji Scientific Instruments Co., Ltd.), the light incident angle dependence of Re was measured, and the optical characteristics were calculated. Re was 1 nm and Rth was 6 nm. This was confirmed (measurement wavelength λ: 589 nm).

<Preparation of polarizing plate A>
Next, iodine is adsorbed on the stretched polyvinyl alcohol film to produce a polarizing film, and a commercially available cellulose acetate film (Fujitac TD80UF, manufactured by Fuji Photo Film Co., Ltd., Re = 3 nm, Rth = 45 nm) is subjected to saponification treatment. A polarizing plate A was formed on one surface of the polarizing film using a polyvinyl alcohol adhesive.

<Preparation of polarizing plate B>
A polarizing film was produced in the same manner, and a commercially available cellulose acetate film (Fujitac TD80UF, manufactured by Fuji Photo Film Co., Ltd.) was saponified and attached to one side of the polarizing film using a polyvinyl alcohol-based adhesive. . In the same manner, the polarizing plate protective film 1 produced as described above was attached to the other surface of the polarizing film to form a polarizing plate B.

<Production of liquid crystal display device>
Using the polyvinyl alcohol-based adhesive for the polarizing plate A, the retardation film 1 of the present invention was prepared so that the first retardation film 1 side was the polarizing film side and the transmission axis of the polarizing film and the first retardation film A polarizing plate 1 was formed on the side of the polarizing film where the cellulose acetate film was not bonded so that the slow axis of the film 1 was parallel.

This is applied to one of the IPS mode liquid crystal cells 1 produced above so that the slow axis of the first retardation film 1 is parallel to the rubbing direction of the liquid crystal cell (that is, the slow phase of the first retardation film 1). The polarizing plate 1 was attached so that the axis is parallel to the slow axis of the liquid crystal molecules of the liquid crystal cell during black display) and the second retardation film 1 side is on the liquid crystal cell side.
Subsequently, the polarizing plate B is pasted on the other side of the IPS mode liquid crystal cell 1 so that the polarizing plate protective film 1 side is on the liquid crystal cell side and in a crossed Nicol arrangement with the polarizing plate 1. A liquid crystal display device was produced. The leakage light of the liquid crystal display device thus manufactured was measured. The leakage light when observed from the left oblique direction of 60 ° was 0.07%. In addition, the leak light in this specification is measured as follows.
First, the liquid crystal cell 1 is placed on the Schaukasten installed in the dark room without attaching the polarizing plate, and the orientation is 45 degrees to the left with respect to the rubbing direction of the liquid crystal cell and from the normal direction of the liquid crystal cell. A luminance of 1 was measured with a luminance meter installed at a distance of 1 m in the direction of 60 °. Next, the liquid crystal display panel of Example 1 is similarly arranged on the same Schaukasten as described above, and the luminance 2 is similarly measured in the dark display state. It was.

[Example 2]
<Production of second retardation films 2 to 7>
In the production of the second retardation film 1, the boronic acid compound in the present invention (the above-described specific example (I-30)) is converted into the above-described specific examples (I-2), (I-23), (I The second retardation films 2 to 5 were produced in the same manner except that the boronic acid compounds represented by -27) and (I-31) were used. In addition, as a comparative example, a second retardation film 6 was prepared in the same manner except that the boronic acid compound in the present invention was not added. Further, a second retardation film 7 was produced which was produced in the same manner as the second retardation film 6 except that the following vertical alignment film (AL-2) was used as the orientation film. The alignment direction of the rod-like liquid crystal of the retardation film thus prepared and the alignment defects were evaluated in the same manner as the second retardation film 1 described above. The results are shown in Table 1 below.

  From the above results, by using the boronic acid compound of the present invention as a vertical alignment agent, the rod-like liquid crystal can be made uniform and vertical with few defects even when a highly industrially modified polyvinyl alcohol is used as the alignment film. It can be seen that an oriented retardation film can be produced. In particular, in the case of a boronic acid having a polymerizable group, it can be seen that the adhesion can be improved.

[Example 3]
Example 1 is the same as Example 1 except that the retardation film 1 of the present invention is replaced with the retardation films 2 to 5 of the present invention in Example 2 and the comparative retardation films 6 and 7. Polarizing plates 2 to 7 were produced. Also, using this, a liquid place display device was produced in the same manner as in Example 1, and the leakage light observed from the left diagonal direction 60 ° was measured. The results are shown in Table 2 below.

表２の結果から、本発明のボロン酸化合物を垂直配向剤として用いることによって、斜め方向からの光漏れの少ない液晶表示装置を作製することができた。

From the results in Table 2, it was possible to produce a liquid crystal display device with little light leakage from an oblique direction by using the boronic acid compound of the present invention as a vertical alignment agent.

It is the schematic which shows the pixel area example of the liquid crystal display device of this invention. It is the schematic which shows an example of the liquid crystal display device of this invention. It is the schematic which shows the other example of the liquid crystal display device of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid crystal element pixel area 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 at the time of white display 7a, 7b, 19a, 19b Protective film for polarizing film 8, 20 Polarizing film 9, 21 Polarizing transmission axis 10 of polarizing film First retardation film 11 Slow axis 12 of first retardation film Second retardation film 13, 17 Cell substrate 14, 18 Cell substrate rubbing direction 15 Liquid crystal Layer 16 Slow axis direction of liquid crystal layer

Claims (6)

  A retardation film comprising an alignment film comprising at least one polymer and an optically anisotropic layer comprising a liquid crystal composition containing at least one rod-like liquid crystalline compound and at least one boronic acid compound. The retardation film according to claim 1, wherein the boronic acid compound is represented by the following general formula (I).

(In the general formula (I), R ¹ and R ² each independently represents a hydrogen atom, a substituted or unsubstituted aliphatic hydrocarbon group, an aryl group or a heterocyclic group, which are connected to each other to form a ring. R ³ represents a substituted or unsubstituted aliphatic hydrocarbon group, aryl group or heterocyclic group.   The retardation film according to claim 1, wherein the boron compound is substituted with a crosslinkable group.   The retardation film according to any one of claims 1 to 3, wherein the molecules of the rod-like liquid crystal compound are aligned substantially perpendicular to the film surface of the retardation film.   The retardation film according to claim 1, wherein the alignment film is made of a polyvinyl alcohol derivative.   At least a first polarizing film, a first retardation film, a second retardation film, and a liquid crystal cell in which a liquid crystal layer including liquid crystal molecules is sandwiched between a pair of substrates. The liquid crystal display device is aligned substantially parallel to the surface of the substrate, and the in-plane retardation (Re) of the first retardation film is 20 nm to 150 nm and Nz is 1.5 to 7. The in-plane refractive indexes of the second retardation film are substantially equal, the thickness direction retardation (Rth) is -80 nm to -400 nm, and the second retardation film is any one of claims 1 to 5. And a transmission axis of the first polarizing film is parallel to a slow axis direction of liquid crystal molecules during black display.

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