JP4495012B2 - Retardation plate, polarizing plate, and liquid crystal display device - Google Patents

Description

  The present invention relates to a retardation plate and a polarizing plate. In particular, the present invention is used for a reflective liquid crystal display device, a transflective liquid crystal display device, a transmissive liquid crystal display device, a GH-LCD, a PS conversion element, an optical disk writing pickup, a brightness enhancement film, or an antireflection film. The present invention relates to a retardation plate effective as a λ / 4 plate.

  The λ / 4 plate has very many uses, and is already used for a reflective LCD, a transflective LCD, a brightness enhancement film, an optical disk pickup, and a PS conversion element. Most of the λ / 4 plates currently used for them are retardation plates that exhibit optical anisotropy by stretching a polymer film. The optical orientation of the polymer film generally corresponds to the longitudinal or lateral direction of the sheet or roll film, and a polymer film having an optical axis or slow axis in the oblique direction of the sheet or roll is manufactured. It is very difficult. In many cases where a retardation plate is used, it is disposed at an angle that is neither parallel nor orthogonal to the transmission axis of the polarizing plate. In many cases, two or more retardation plates and polarizing plates are arranged at angles that are neither parallel nor orthogonal. In general, since the transmission axis of the polarizing plate is perpendicular to the roll film, in order to attach the retardation plate and the polarizing plate, cut each film at a predetermined angle and attach the resulting chip. It is necessary to match. When trying to manufacture a laminate of a retardation plate and a polarizing plate by chip bonding, an adhesive coating process, chip cutting or chip bonding process is required, and the process is complicated and the quality due to axial misalignment Decline is likely to occur, yield is reduced, cost is increased, and degradation due to contamination is likely to occur. In the polymer film, the expression of refractive index anisotropy in the three-dimensional direction is affected by various conditions such as the draw ratio, temperature, draw speed, and molecular weight of the polymer. Therefore, it is difficult to precisely control the optical anisotropy of the polymer film.

In order to solve such a problem, a roll-like film is coated with a coating liquid containing a discotic liquid crystal compound or a rod-like liquid crystal compound, and is oriented in a predetermined direction to develop optical anisotropy. In contrast, a phase difference plate having a slow axis at an angle that is neither parallel nor orthogonal is proposed (Patent Documents 1 and 2). Further, there is disclosed a retardation plate in which an orientation is fixed so that a disc surface of a discotic liquid crystalline compound is substantially perpendicular to a film surface (Patent Documents 3, 4, 5, and 6). In the prior art, problems such as alignment defects and cissing at the time of alignment occurred. Furthermore, it is necessary to modify the polymer in order to impart vertical alignment, or to synthesize the polymer using a special monomer, resulting in an expensive alignment film. A technique for aligning a discotic liquid crystalline compound substantially vertically using an inexpensive alignment film has been demanded. In addition, when a retardation plate is used in a liquid crystal display device, the retardation plate consisting of a layer in which a discotic liquid crystalline compound is substantially vertically aligned has a three-dimensional refractive index so as to be optimal in each liquid crystal mode. It is difficult to develop anisotropy, and a technique that can arbitrarily control the refractive index anisotropy in the three-dimensional direction has been demanded.
JP 2001-4837 A JP 2004-53841 A Japanese Patent Laid-Open No. 9-292522 JP 2000-56310 A JP 2000-104073 A JP 2000-105316 A

  The present invention has been made in view of the above-mentioned problems, and provides a retardation plate that contributes to improvement of display characteristics of a liquid crystal display device, and a retardation plate integrated polarizing plate with significantly improved productivity. Objective. Another object of the present invention is to provide a liquid crystal display device with a wide viewing angle and a liquid crystal display device with improved backlight utilization efficiency by using the retardation plate or polarizing plate.

The object of the present invention has been achieved by the following liquid crystal display device.
(1) A retardation plate having an optically anisotropic layer containing at least one liquid crystalline compound having a positive optical anisotropy and at least one liquid crystalline compound having a negative optical anisotropy, the Nz of retardation plates when defining as the following equation (1), the Nz is rather smaller than 0, the liquid crystalline compound optical anisotropy is positive is a rod-like liquid crystal compound, the optically anisotropic The liquid crystalline compound having negative properties is a discotic liquid crystalline compound, and the alignment state is fixed so that the disc surface of the discotic liquid crystalline compound is substantially perpendicular to the optically anisotropic layer surface. A retardation plate in which an alignment state is fixed so that a major axis direction of the rod-like liquid crystal compound is substantially perpendicular to a surface of the optically anisotropic layer.
Formula (1)
Nz = 0.5 + Rth / Re
(In the formula (1), Re and Rth respectively represent the in-plane retardation value of the retardation film and the retardation value in the thickness direction.)
( 2 ) The optically anisotropic layer is provided on a support, the in-plane retardation (Re) of the support is 0 to 20 nm, and the retardation (Rth) in the thickness direction is −100 nm to The phase difference plate according to ( 1), which is 100 nm.
( 3 ) A polarizing plate having the retardation plate according to (1) or (2) and a polarizing film.
( 4 ) A liquid crystal display device comprising the retardation plate according to (1) or (2) or the polarizing plate according to ( 3) and a liquid crystal cell.

  ADVANTAGE OF THE INVENTION According to this invention, the phase difference plate contributed to the improvement of the display characteristic of a liquid crystal display device, and the phase difference plate integrated polarizing plate which improved remarkably can be provided. In addition, according to the present invention, it is possible to provide a liquid crystal display device with a wide viewing angle and a liquid crystal display device with improved backlight utilization efficiency.

BEST MODE FOR CARRYING OUT THE INVENTION

  Hereinafter, embodiments of the retardation plate, the polarizing plate, and the liquid crystal display device of the present invention will be sequentially described. 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 this specification, “parallel” and “orthogonal” mean that the angle is within a range of strict angle ± 10 ° or less. 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” means a direction in which the refractive index is maximum in the film plane. 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, “polarizing plate” is cut into a size to be incorporated into a long polarizing plate and a liquid crystal device unless otherwise specified (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. “Polarizing plate” means a laminate having a transparent protective film for protecting the polarizing film on at least one side of the “polarizing film”. It shall be.

  In this specification, Re and Rth respectively represent in-plane retardation and retardation in the thickness direction at a certain wavelength λ nm. Re is measured with KOBRA 21ADH (manufactured by Oji Scientific Instruments Co., Ltd.) by making light of wavelength λ nm incident in the normal direction of the film. Rth was measured by making light having a wavelength of λ nm incident from a direction inclined + 40 ° with respect to the normal direction of the film with the slow axis in the plane (determined by KOBRA 21ADH) as the tilt axis (rotation axis). The retardation value and the retardation value measured by making light of wavelength λ nm incident from a direction inclined −40 ° with respect to the film normal direction with the in-plane slow axis as the tilt axis (rotation axis) in three directions in total. KOBRA 21ADH is calculated based on the measured retardation value, the assumed value of average refractive index, and the input film thickness value. Here, as the assumed value of the average refractive index, values in the polymer handbook (JOHN WILEY & SONS, INC) and catalogs of various optical films can be used. Those whose average refractive index is not known can be measured with an Abbe refractometer. The average refractive index values of main optical films are exemplified below: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), Polystyrene (1.59).

[Phase difference plate]
The retardation plate of the present invention is composed of a composition containing at least one liquid crystalline compound, and includes an optically anisotropic layer formed by fixing molecules of the liquid crystalline compound in an aligned state. The retardation plate has an in-plane retardation value and a retardation value in the thickness direction as Re and Rth, respectively, and Nz is smaller than 0 when Nz is defined as in the following formula (1). Nz is preferably −5 to −0.1, more preferably −4.5 to −0.2 or less, and further preferably −4 to −0.3 or less.
Nz = 0.5 + Rth / Re (1)
The retardation value measured from the normal direction of the retardation plate plane is Re (0), the retardation value measured by tilting the retardation plate by 40 ° with the slow axis of the retardation plate as the tilt axis. Re (40), Re (0), Re (40), Re (−40) where Re (−40) is a retardation value measured by tilting the retardation plate by 40 ° in the direction opposite to the tilt direction. ) And the thickness and average refractive index of the retardation plate, the refractive index (Rth) in the thickness direction can be calculated.

  In the retardation plate of the present invention, Re is preferably 50 to 200 nm, more preferably 70 to 180 nm, and further preferably 90 to 160 nm. Further, it is preferable that the Re (40) and Re (−40) are substantially equal. The difference between Re (40) and Re (−40) is more preferably 0 nm. However, in consideration of measurement error and the like, in this specification, the difference is substantially equal to the range of 4 nm. To do.

[Optically anisotropic layer containing liquid crystalline compound]
The optically anisotropic layer included in the retardation plate of the present invention includes both a liquid crystalline compound having positive optical anisotropy and a liquid crystalline compound having negative optical anisotropy. In the present invention, the liquid crystalline compound having positive optical anisotropy means that when two of the three main refractive indexes of the compound are assumed to be equal, the remaining main refractive index is higher than the other two main refractive indexes. In the present invention, a rod-like liquid crystal compound is used . On the other hand, the liquid crystalline compound having negative optical anisotropy means a case where the remaining main refractive index is smaller than the other two main refractive indexes, and a discotic liquid crystalline compound is used in the present invention . In the present invention, as long as the liquid crystal compound having a positive optical anisotropy and the liquid crystal compound having a negative optical anisotropy are each mixed in one or more and satisfy the above optical characteristics, Is not particularly limited. For example, after forming a low molecular weight liquid crystalline compound in a nematic orientation in a liquid crystal state, an optically anisotropic layer obtained by fixing by photocrosslinking or thermal crosslinking, or after forming a polymer liquid crystalline compound in a nematic orientation in a liquid crystal state, An optically anisotropic layer obtained by fixing the orientation by cooling can be used. In the present invention, even when a liquid crystalline compound is used for the optically anisotropic layer, the optically anisotropic layer is a layer formed by fixing the compound by polymerization or the like, and thus becomes a layer. After that, it is no longer necessary to show liquid crystallinity. The polymerizable liquid crystalline compound contained in the optically anisotropic layer may be a polyfunctional polymerizable liquid crystalline compound or a monofunctional polymerizable liquid crystalline compound.

The optically anisotropic layer may consist of only one layer, or may be a laminate of two or more optically anisotropic layers. It is sufficient that at least one optically anisotropic layer satisfies the requirements of the optically anisotropic layer, and an optically anisotropic layer that does not satisfy the requirements may be included separately. Orientation state of the liquid crystal compound satisfies the phase difference plate above formula (1) is Ri substantially vertical der disc plane of DISCO tic liquid crystal compound to the film plane, the long axis of the rod-shaped liquid crystalline compound Is substantially perpendicular to the film plane . The term “substantially perpendicular to the discotic liquid crystalline compound” means that the angle formed by the film plane and the disc surface of the discotic liquid crystalline compound is in the range of 70 ° to 90 °. The tilt orientation may be such that the average tilt angle of the disk surface falls within this range, or hybrid orientation in which the tilt angle gradually changes may be used. Even in the case of tilt orientation or hybrid orientation, the average tilt angle is preferably 70 ° to 90 °, more preferably 80 ° to 90 °, and most preferably 85 ° to 90 °. The term “substantially perpendicular to the rod-like liquid crystalline compound” means that the angle formed by the film plane and the director of the rod-like liquid crystalline compound is in the range of 70 ° to 90 °. Tilt orientation may be performed so that the average tilt angle falls within this range, or hybrid orientation in which the tilt angle gradually changes may be performed. Even in the case of tilt alignment or hybrid alignment, the average tilt angle of the rod-like liquid crystal compound is preferably 70 ° to 90 °, more preferably 80 ° to 90 °, and most preferably 85 ° to 90 °. More preferably, the disc surface of the discotic liquid crystalline compound is substantially perpendicular to the film plane, and the major axis of the rod-like liquid crystalline compound is substantially perpendicular to the film plane.

  The optically anisotropic layer supports a coating liquid containing a liquid crystal compound such as a rod-like liquid crystal compound or a discotic liquid crystal compound and, if desired, the following polymerization initiator, air interface alignment agent, and other additives. It can be formed by applying on the body. It is preferable to form an alignment film on a support and apply the coating solution on the surface of the alignment film.

[Discotic liquid crystalline compounds]
In the present invention, the optically anisotropic layer is preferably formed using a discotic liquid crystalline compound. Discotic liquid crystalline compounds are disclosed in various documents (C. Destrade et al., Mol. Crysr. Liq. Cryst., Vol. 71, page 111 (1981); edited by The Chemical Society of Japan, Quarterly Chemical Review, No. 22, Liquid Crystal Chemistry, Chapter 5, Chapter 10 Section 2 (1994); B. Kohne et al., Angew. Chem. Soc. Chem. Comm., Page 1794 (1985); J. Zhang et al., J Am.Chem.Soc., Vol.116, page 2655 (1994)). The polymerization of discotic liquid crystalline compounds is described in JP-A-8-27284.

The discotic liquid crystalline compound preferably has a polymerizable group so that it can be fixed by polymerization. For example, a structure in which a polymerizable group is bonded as a substituent to a discotic core of a discotic liquid crystalline compound is conceivable. However, when a polymerizable group is directly connected to the discotic core, the alignment state is maintained in the polymerization reaction. It becomes difficult. Therefore, a structure having a linking group between the discotic core and the polymerizable group is preferable. That is, the discotic liquid crystalline compound having a polymerizable group is preferably a compound represented by the following formula.
D (-LP) _n
In the formula, D is a discotic core, L is a divalent linking group, P is a polymerizable group, and n is an integer of 4 to 12. Preferred specific examples of the discotic core (D), the divalent linking group (L) and the polymerizable group (P) in the above formula are (D1) to (D15) described in JP-A No. 2001-4837, respectively. ), (L1) to (L25), and (P1) to (P18), and the contents described in the publication can be preferably used. In addition, the discotic nematic liquid crystal phase-solid phase transition temperature of the liquid crystal compound is preferably 70 to 300 ° C, and more preferably 70 to 170 ° C.

[Bar-shaped liquid crystalline compound]
In the present invention, it is preferable to form an optically anisotropic layer using a rod-like liquid crystalline compound. Examples of rod-like liquid crystalline compounds 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. Not only the above low-molecular liquid crystalline compounds but also high-molecular liquid crystalline compounds can be used. It is more preferable to fix the alignment of the rod-like liquid crystal compound by polymerization. As the liquid crystalline compound, those having a partial structure capable of causing polymerization or crosslinking reaction by actinic rays, electron beams, heat, or the like are suitably used. The number of the partial structures is preferably 1 to 6, more preferably 1 to 3. As the polymerizable rod-like liquid crystalline compound, Makromol. Chem. 190, 2255 (1989), Advanced Materials 5, 107 (1993), US Pat. Nos. 4,683,327, 5,622,648, and 5,770,107, International Publication WO95 / 22586. No. 95/24455, No. 97/00600, No. 98/23580, No. 98/52905, JP-A-1-272551, No. 6-16616, and No. 7-110469. 11-80081 and JP-A 2001-328773, and the like can be used.
In the present invention, the mass part ratio of the rod-like liquid crystal compound to the discotic liquid crystal compound is preferably 1 or less.

[Vertical alignment accelerator]
In order to uniformly and vertically align the discotic liquid crystalline compound and the rod-shaped liquid crystalline compound, it is necessary to vertically control the liquid crystalline compound on the alignment film interface side and the air interface side. For this purpose, a composition obtained by adding a compound having a function of vertically aligning a liquid crystalline compound by an excluded volume effect, an electrostatic effect, or a surface energy effect may be employed in the alignment film. In addition, for the alignment control on the air interface side, a compound that is unevenly distributed at the air interface during the alignment of the liquid crystalline compound and acts to align the liquid crystalline compound vertically by its excluded volume effect, electrostatic effect, or surface energy effect is blended The composition (hereinafter, sometimes simply referred to as “liquid crystal composition”) may be employed. As such a compound (alignment film interface side vertical alignment agent) that promotes the vertical alignment of the molecules of the liquid crystal compound on the alignment film interface side, a pyridinium derivative is preferably used. As a compound (air interface side vertical alignment agent) that promotes the vertical alignment of the molecules of the liquid crystal compound on the air interface side, a fluoro aliphatic group that promotes the uneven distribution of the compound on the air interface side, One or more hydrophilic groups selected from the group consisting of a carboxyl group (—COOH), a sulfo group (—SO ₃ H), a phosphonoxy group {—OP (═O) (OH) ₂ }, and salts thereof A compound is preferably used. Further, by blending these compounds, for example, when a liquid crystalline composition is prepared as a coating solution, the coating property of the coating solution is improved, and the occurrence of unevenness and repellency is suppressed. The vertical alignment agent will be described in detail below.

[Alignment film interface side vertical alignment agent]
As the alignment film interface-side vertical alignment agent that can be used in the present invention, a pyridinium derivative (pyridinium salt) represented by the following formula (I) is preferably used. By adding at least one of the pyridinium derivatives to the liquid crystalline composition, the molecules of the discotic liquid crystalline compound can be aligned substantially vertically in the vicinity of the alignment film.

In the formula (I), L ¹ represents a divalent linking group, an alkylene group and —O—, —S—, —CO—, —SO ₂ —, —NR ^a — (where R ^a is the number of carbon atoms. Is a divalent linking group having 1 to 20 carbon atoms, which is a combination of an alkenylene group, an alkynylene group or an arylene group. The alkylene group may be linear or branched.

In the formula (I), R ¹ is a hydrogen atom, an unsubstituted amino group, or a substituted amino group substituted with a substituent having 1 to 20 carbon atoms. When R ¹ is a substituted amino group, it is preferably substituted with an aliphatic group. Examples of the aliphatic group include an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an alkynyl group, and a substituted alkynyl group. When R ¹ is a disubstituted amino group, two aliphatic groups may be bonded to each other to form a nitrogen-containing heterocyclic ring. The nitrogen-containing heterocycle formed at this time is preferably a 5-membered ring or a 6-membered ring. R ¹ is preferably a hydrogen atom, an unsubstituted amino group or a substituted amino group having 1 to 20 carbon atoms, a hydrogen atom, an unsubstituted amino group or a substituted amino group having 2 to 12 carbon atoms. More preferably, it is more preferably a hydrogen atom, an unsubstituted amino group, or a substituted amino group having 2 to 8 carbon atoms. When R ¹ is an amino group, it is preferably substituted at the 4-position of the pyridinium ring.

  In the formula (I), X is an anion. Examples of anions include halogen anions (for example, fluorine ions, chlorine ions, bromine ions, iodine ions, etc.), sulfonate ions (for example, methanesulfonate ions, trifluoromethanesulfonate ions, methylsulfate ions, p-toluene). Sulfonate ion, p-chlorobenzenesulfonate ion, 1,3-benzenedisulfonate ion, 1,5-naphthalenedisulfonate ion, 2,6-naphthalenedisulfonate ion, sulfate ion, carbonate ion, nitrate ion, thiocyanate Examples include acid ions, perchlorate ions, tetrafluoroborate ions, picrate ions, acetate ions, formate ions, trifluoroacetate ions, phosphate ions (for example, hexafluorophosphate ions), and hydroxide ions. X is preferably a halogen anion, a sulfonate ion, or a hydroxide ion.

In the formula (I), Y ¹ is a divalent linking group having 1 to 30 carbon atoms having a 5-membered or 6-membered ring as a partial structure. The cyclic partial structure contained in Y ¹ is more preferably a cyclohexyl ring, an aromatic ring or a heterocyclic ring. Examples of the aromatic ring include a benzene ring, an indene ring, a naphthalene ring, a fluorene ring, a phenanthrene ring, an anthracene ring, a biphenyl ring, and a pyrene ring. More preferred are a benzene ring, a biphenyl ring, and a naphthalene ring. The hetero atom constituting the hetero ring is preferably a nitrogen atom, an oxygen atom or a sulfur atom. For example, a furan ring, thiophene ring, pyrrole ring, pyrroline ring, pyrrolidine ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole Ring, imidazole ring, imidazoline ring, imidazolidine ring, pyrazole ring, pyrazoline ring, pyrazolidine ring, triazole ring, furazane ring, tetrazole ring, pyran ring, dioxane ring, dithiane ring, thiine ring, pyridine ring, piperidine ring, oxazine ring Morpholine ring, thiazine ring, pyridazine ring, pyrimidine ring, pyrazine ring, piperazine ring and triazine ring. The heterocycle is preferably a 6-membered ring. The divalent linking group having a 5-membered or 6-membered ring represented by Y as a partial structure may have a substituent.

In the formula (I), Z represents a halogen-substituted phenyl group, a nitro-substituted phenyl group, a cyano-substituted phenyl group, a phenyl group substituted with an alkyl group having 1 to 10 carbon atoms, or an alkoxy having 2 to 10 carbon atoms. A phenyl group substituted with a group, an alkyl group having 1 to 12 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkoxy having 2 to 13 carbon atoms A carbonyl group, an aryloxycarbonyl group having 7 to 26 carbon atoms, an arylcarbonyloxy group having 7 to 26 carbon atoms, a cyano-substituted phenyl group, a halogen-substituted phenyl group, and an alkyl having 1 to 10 carbon atoms. Phenyl group substituted with a group, phenyl group substituted with an alkoxy group having 2 to 10 carbon atoms, aryloxycarboe having 7 to 26 carbon atoms Le group or carbon atoms is preferably an aryl carbonyl group having 7 to 26.
Z may further have a substituent. Examples of the substituent include a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom), a cyano group, a nitro group, and a carbon atom number of 1 to 16. An alkyl group having 1 to 16 carbon atoms, an alkynyl group having 1 to 16 carbon atoms, a halogen-substituted alkyl group having 1 to 16 carbon atoms, an alkoxy group having 1 to 16 carbon atoms, An acyl group having 2 to 16 carbon atoms, an alkylthio group having 1 to 16 carbon atoms, an acyloxy group having 2 to 16 carbon atoms, an alkoxycarbonyl group having 2 to 16 carbon atoms, a carbamoyl group, a carbon atom An alkyl-substituted carbamoyl group having 2 to 16 carbon atoms and an acylamino group having 2 to 16 carbon atoms are included.

  The pyridinium compound used in the present invention is preferably a pyridinium compound represented by the following formula (Ia).

In the formula (Ia), L ³ represents a single bond, —O—, —O—CO—, —CO—O—, —C≡C—, —CH═CH—, —CH═N—, —N═. CH—, —N═N—, —O—AL—O—, —O—AL—O—CO—, —O—AL—CO—O—, —CO—O—AL—O—, —CO—. O-AL-O-CO-, -CO-O-AL-CO-O-, -O-CO-AL-O-, -O-CO-AL-O-CO- or -O-CO-AL- CO-O-. AL is an alkylene group having 1 to 10 carbon atoms. L ³ represents a single bond, —O—, —O—AL—O—, —O—AL—O—CO—, —O—AL—CO—O—, —CO—O—AL—O—, — CO-O-AL-O-CO-, -CO-O-AL-CO-O-, -O-CO-AL-O-, -O-CO-AL-O-CO- or -O-CO- AL-CO-O- is preferable, and a single bond or -O- is more preferable.

In the formula (Ia), L ⁴ represents a single bond, —O—, —O—CO—, —CO—O—, —C≡C—, —CH═CH—, —CH═N—, —N═. CH- or -N = N-.

In the formula (Ia), R ³ is a hydrogen atom, an unsubstituted amino group, or an alkyl-substituted amino group having 2 to 20 carbon atoms. When R ³ is a dialkyl-substituted amino group, two alkyl groups may be bonded to each other to form a nitrogen-containing heterocyclic ring. The nitrogen-containing heterocycle formed at this time is preferably a 5-membered ring or a 6-membered ring. R ³ is more preferably a hydrogen atom, an unsubstituted amino group or a dialkyl-substituted amino group having 2 to 12 carbon atoms, and most preferably a hydrogen atom, an unsubstituted amino group or a dialkyl-substituted amino group having 2 to 8 carbon atoms. . When R ³ is an unsubstituted amino group, the 4-position of the pyridinium ring is preferably amino-substituted.

In the formula (Ia), Y ² and Y ³ are each independently a divalent group consisting of a 6-membered ring optionally having a substituent. Examples of the 6-membered ring include an aliphatic ring, an aromatic ring (benzene ring), and a heterocyclic ring. Examples of the 6-membered aliphatic ring include a cyclohexane ring, a cyclohexene ring, and a cyclohexadiene ring. Examples of 6-membered heterocycles include pyran ring, dioxane ring, dithiane ring, thiine ring, pyridine ring, piperidine ring, oxazine ring, morpholine ring, thiazine ring, pyridazine ring, pyrimidine ring, pyrazine ring, piperazine ring and triazine ring. Can be mentioned. Another 6-membered ring or 5-membered ring may be condensed to the 6-membered ring.
Examples of the substituent include a halogen atom, a cyano group, an alkyl group having 1 to 12 carbon atoms, and an alkoxy group having 1 to 12 carbon atoms. The alkyl group and the alkoxy group may be substituted with an acyl group having 2 to 12 carbon atoms or an acyloxy group having 2 to 12 carbon atoms. The definition of an acyl group and an acyloxy group will be described later.

In the formula (Ia), X ¹ is an anion. X ¹ is preferably a monovalent anion. Examples of anions include halogen anions (eg, fluorine ions, chlorine ions, bromine ions, iodine ions) and sulfonate ions (eg, methanesulfonate ions, p-toluenesulfonate ions, benzenesulfonate ions). It is.

In Formula (Ia), Z ¹ is a hydrogen atom, a cyano group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms, and the alkyl group and the alkoxy group are each a carbon atom. It may be substituted with an acyl group having 2 to 12 atoms or an acyloxy group having 2 to 12 carbon atoms.

In the formula (Ia), m is 1 or 2, and when m is 2, two L ⁴ and two Y ³ may be different.
When m is 2, Z ¹ is preferably a cyano group, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms.
When m is 1, Z ¹ is an alkyl group having 7 to 12 carbon atoms, an alkoxy group having 7 to 12 carbon atoms, an acyl-substituted alkyl group having 7 to 12 carbon atoms, and 7 carbon atoms. It is preferably an acyl-substituted alkoxy group of -12, an acyloxy-substituted alkyl group having 7-12 carbon atoms, or an acyloxy-substituted alkoxy group having 7-12 carbon atoms.

  The acyl group is represented by —CO—R, the acyloxy group is represented by —O—CO—R, and R is an aliphatic group (alkyl group, substituted alkyl group, alkenyl group, substituted alkenyl group, alkynyl group, substituted alkynyl group) or aromatic. Group (aryl group, substituted aryl group). R is preferably an aliphatic group, and more preferably an alkyl group or an alkenyl group.

In formula (Ia), p is an integer of 1-10. C _p H _2p means a chain alkylene group which may have a branched structure. C _p H _2p is preferably a linear alkylene group. Further, p is more preferably 1 or 2.

  Specific examples of the compound represented by formula (I) and / or (Ia) are shown below. Here, Me represents a methyl group.

  A pyridinium derivative is generally obtained by alkylating a pyridine ring (Menstokin reaction).

  The preferable range of the content of the pyridinium derivative in the liquid crystal composition varies depending on the use, but 0.005 in the liquid crystal composition (liquid crystal composition excluding the solvent when prepared as a coating liquid). It is preferably -8% by mass, more preferably 0.01-5% by mass.

[Air interface side vertical alignment agent]
As the air interface side vertical alignment agent usable in the present invention, a fluoro aliphatic group, a carboxyl group (—COOH), a sulfo group (—SO ₃ H), a phosphonoxy group {—OP (═O) (OH) ₂ } And one or more hydrophilic groups selected from the group consisting of the salts thereof, a fluoroaliphatic group-containing polymer (hereinafter referred to as “fluorinated polymer”), or a compound represented by the general formula (III) Fluorine compounds are preferably used.

First, the fluorine polymer will be described.
The fluoropolymer usable in the present invention includes a fluoroaliphatic group, a carboxyl group (—COOH), a sulfo group (—SO ₃ H), a phosphonoxy group {—OP (═O) (OH) ₂ }, and their It contains one or more hydrophilic groups selected from the group consisting of salts. The types of polymers are described in “Revised Chemistry of Polymer Synthesis” (written by Takayuki Otsu, published by Kagaku Dojin Co., 1968) on pages 1 to 4, for example, polyolefins, polyesters, polyamides, polyimides. , Polyurethanes, polycarbonates, polysulfones, polycarbonates, polyethers, polyacetals, polyketones, polyphenylene oxides, polyphenylene sulfides, polyarylates, polytetrafluoroethylene (PTFE), polyvinylidene fluorides And cellulose derivatives. 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 needed, and used for the production of a fluoropolymer.

  Specific examples of monomers that can be used in the production of the fluorine-based polymer that can be used in the present invention are listed below, but the present invention is not limited to the following specific examples.

  One embodiment of the fluorine-based polymer that can be used in the present invention is represented by a repeating unit derived from a fluoroaliphatic group-containing monomer (hereinafter sometimes referred to as “fluorine-based monomer”) and the following formula (II): It is a copolymer having a repeating unit containing a hydrophilic group.

In the above formula (II), R ¹ , R ² and R ³³ each independently represents 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, or 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 ^b — (R ^b represents a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group), —S—, —SO ₂ —, —P (═O) (OR ^f ) — (R ^f represents an alkyl group, an aryl group, or an aralkyl group), an alkylene group, and an arylene group.

In formula (II), R ¹ , R ² and R ³³ each independently represent a hydrogen atom or a substituent selected from the substituent group exemplified below.
(Substituent group)
An alkyl group (preferably an alkyl group having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, still more 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, More preferably, it is a C2-C8 alkenyl group, for example, a vinyl group, an aryl group, 2-butenyl group, 3-pentenyl group etc., an alkynyl group (preferably C2-C20, more preferably). Is an alkynyl group having 2 to 12 carbon atoms, more preferably 2 to 8 carbon atoms, such as a propargyl group or a 3-pentynyl group. An aryl group (preferably an aryl group having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, still more preferably 6 to 12 carbon atoms, such as a phenyl group, a p-methylphenyl group, A naphthyl group), an aralkyl group (preferably an aralkyl group having 7 to 30 carbon atoms, more preferably 7 to 20 carbon atoms, still more preferably 7 to 12 carbon atoms, such as a benzyl group, a phenethyl group, A 3-phenylpropyl group), a substituted or unsubstituted amino group (preferably an amino group having 0 to 20 carbon atoms, more preferably 0 to 10 carbon atoms, still more preferably 0 to 6 carbon atoms, For example, an unsubstituted amino group, a methylamino group, a dimethylamino group, a diethylamino group, an anilino group, etc.)

An alkoxy group (preferably an alkoxy group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, still more 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, still more 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, still more 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, still more preferably 2 carbon atoms 10 acylamino groups such as acetylamino group and benzoylamino group), alkoxycarbonylamino groups (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, still more preferably 2 to 2 carbon atoms). 12 alkoxycarbonylamino groups, for example, a methoxycarbonylamino group and the like, and aryloxycarbonylamino groups (preferably having 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, still more preferably 7 carbon atoms). To 12 aryloxycarbonylamino groups, such as phenyloxycarbonylamino group, and sulfonylamino groups (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and still more preferably carbon atoms). 1 to 12 sulfonylamino groups, for example, Sulfonylamino groups, benzenesulfonylamino groups, etc.), sulfamoyl groups (preferably 0-20 carbon atoms, more preferably 0-16 carbon atoms, still more preferably 0-12 carbon atoms sulfamoyl groups, , Sulfamoyl 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, still more preferably A carbamoyl group having 1 to 12 carbon atoms, and examples thereof include an unsubstituted carbamoyl group, a methylcarbamoyl group, a diethylcarbamoyl group, and a phenylcarbamoyl group).

An alkylthio group (preferably an alkylthio group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, still more preferably 1 to 12 carbon atoms, such as a methylthio group and an ethylthio group), an arylthio group ( Preferably it is a C6-C20, More preferably, it is a C6-C16, More preferably, it is a 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, still more preferably 1 to 12 carbon atoms, and examples thereof include a mesyl group and a tosyl group), a sulfinyl group (preferably having a carbon number of 1 to 20, and more. A sulfinyl group having 1 to 16 carbon atoms, more preferably 1 to 12 carbon atoms, is preferable. A ureido group (preferably a benzenesulfinyl group), a ureido group (preferably a ureido group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and still more preferably 1 to 12 carbon atoms. 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, and further preferably having 1 to 12 carbon atoms) Group such as diethyl phosphoramide group and phenylphosphoric acid amide group), hydroxy group, mercapto group, halogen atom (eg fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group Group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, heterocyclic group (preferably A heterocyclic group having 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, such as a heterocyclic group having a hetero atom such as a nitrogen atom, an oxygen atom, or a sulfur atom, such as an imidazolyl group, a pyridyl group, or a quinolyl group; Group, 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, More preferably, it is 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 ³³ are each independently a hydrogen atom, an alkyl group, a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom or 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 ^{b in} —NR ^b — represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group, and preferably a hydrogen atom or an alkyl group. R ^f in —PO (OR ^f ) — represents an alkyl group, an aryl group or an aralkyl group, and preferably an alkyl group. When R ^b and R ^f represent an alkyl group, an aryl group, or an aralkyl group, the number of carbon atoms is the same as that described in the “substituent group”. L preferably contains a single bond, —O—, —CO—, —NR ^b —, —S—, —SO ₂ —, an alkylene group or an arylene group, and —CO—, —O—, —NR It is particularly preferable that ^b- , an alkylene group or an arylene group is contained. When L includes an alkylene group, the alkylene group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and still more preferably 1 to 6 carbon atoms. Specific examples of particularly preferable alkylene groups include a methylene group, an ethylene group, a trimethylene group, a tetrabutylene group, and a hexamethylene group. When L contains an arylene group, the carbon number of the arylene group is preferably 6 to 24, more preferably 6 to 18, and still more preferably 6 to 12. Specific examples of particularly preferred arylene groups include phenylene groups 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 still more 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. As such a substituent, the same substituents as those described above as the substituents for R ¹ , R ² and R ³³ can be exemplified.
The specific structure of L is illustrated below.

  In the formula (II), 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, Trimethylbenzylammonium, dimethylphenylammonium, etc.), pyridinium salts, etc.), sulfo groups, salts of sulfo groups (examples of cations forming the salts are the same as those described above for carboxyl groups), phosphonoxy groups, salts of phosphonoxy groups ( Examples of the cation forming the salt are the same as those described 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 formula (II) 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 two 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-eicocene, 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 (polyoxyethylene added mole number: 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 polyvalent carboxylic 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 .

  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 formula (II) 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. More preferably, it is 1 to 10% by mass. Since the above-mentioned mass percentage is likely to vary in a preferable range depending on the molecular weight of the monomer used, the content of the repeating unit represented by the formula (II) is expressed by the number of functional group moles per unit mass of the polymer. Can be defined accurately. When this notation is used, the preferred amount of the hydrophilic group (Q in the formula (II)) contained in the fluoropolymer is 0.1 mmol / g to 10 mmol / g, and the more preferred amount is 0. .2 mmol / g to 8 mmol / g.

  The fluoropolymer used in the present invention has a mass average molecular weight of preferably 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 polymerization method of the fluorine-based polymer is not particularly limited. For example, a polymerization method such as cation polymerization, radical polymerization, or anion polymerization using a vinyl group can be employed. Polymerization is particularly preferred in that 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 hydroperoxide, 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) Beam, such as potassium sulphate). Such radical thermal polymerization initiators can be used alone 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. These organic solvents can be used alone or in combination of two or more. 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, 1,1,1-trichloroethane, 1,1,1-tribromooctane, etc.) and low-activity monomers (α-methylstyrene, α-methylstyrene dimer, etc.) can be used, but preferably It is a mercaptan having 4 to 16 carbon atoms. The amount of these chain transfer agents to be 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%, more preferably 0.05 mol% to 30 mol%, still more 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.

  In addition, what has a polymeric group as a substituent in order for the fluorine-type polymer of this invention to fix the orientation state of a discotic liquid crystalline compound is also preferable.

  Specific examples that can be preferably used in the present invention as fluorine-based polymers 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 the mass average molecular weight in terms of PEO measured by GPC.

  The fluoropolymer used in the present invention can be produced by a publicly known and commonly used method. For example, it can be produced by adding a general-purpose radical polymerization initiator to an organic solvent containing the above-mentioned fluorine-based monomer, a monomer having a hydrogen bonding group, and the like, and polymerizing it. 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.

  The preferred range of the content of the fluoropolymer in the liquid crystalline composition (liquid crystalline composition composition excluding the solvent when prepared as a coating liquid) varies depending on the use, but the composition (coating liquid In the composition excluding the solvent), it is preferably 0.005 to 8% by mass, more preferably 0.01 to 5% by mass, and 0.05 to 1% by mass. Is 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 may not be sufficiently dried or the performance as an optical film (for example, retardation) Adverse effects on the uniformity of

Next, the fluorine-containing compound represented by the formula (III) that can be similarly used as the air interface side vertical alignment agent will be described.
Formula (III)
(R ⁰ ) _mo −L ⁰ − (W) _no
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 mo 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 a (mo + no) -valent linking group, W represents a carboxyl group (—COOH) or a salt thereof, a sulfo group (—SO ₃ H) or a salt thereof, or phosphonoxy {—OP (═O) (OH) ₂ } Or a salt thereof, and no represents an integer of 1 or more.

In the formula (III), 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 even more preferably 4 to 8. The alkyl group having a CF ₃ 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. 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 even more 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 the hydrogen atoms in the alkyl group are preferably substituted with fluorine atoms, more preferably 60% or more are substituted, and even more preferably 70% or more are substituted. The remaining hydrogen atoms may be further substituted with a substituent 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 (III), the (mo + no) -valent linking group represented by L ⁰ is an alkylene group, an alkenylene group, an aromatic group, a heterocyclic group, —CO—, —NR ^d — (R ^d is the number of carbon atoms) Is 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 (III), W represents a carboxyl group (—COOH) or a salt thereof, a sulfo group (—SO ₃ H) or a salt thereof, or a phosphonoxy group {—OP (═O) (OH) ₂ } or a salt thereof. . The preferred range of W is the same as Q in formula (II).

  Among the fluorine-containing compounds represented by the formula (III), compounds represented by the following formula (III) -a or formula (III) -b are preferable.

In the formula (III) -a, R ⁴ and R ⁵ 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, and R ⁴ and R ⁵ are simultaneously It is not an alkyl group. 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, phosphonoxy {—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 or a phosphonoxy group as a substituent is represented, but W ¹ and W ² are not simultaneously hydrogen atoms.

Formula (III) -b
_{^{(R 6 -L 2 -) m2}} (Ar 1) -W 3
In the formula (III) -b, R ⁶ 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, R ⁶ 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 ² represents 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—, It represents a divalent linking group selected from the group consisting of —SO ₂ — and combinations thereof, and a plurality of L ² 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 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 or a phosphonoxy group as a substituent.

First, the formula (III) -a will be described.
R ⁴ and R ⁵ have the same meaning as R ⁰ in the formula (III), and their preferred ranges are also the same. The carboxyl group (—COOH) represented by W ¹ and W ² 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 is It is synonymous with W in Formula (III), and its preferable range is also the same. The alkyl group having a carboxyl group, a sulfo group or a phosphonoxy group as a substituent represented by W ¹ and W ² may be linear or branched, and preferably has 1 to 20 carbon atoms. It is an alkyl group, More preferably, it is a 1-8 alkyl group, Most preferably, it is a 1-3 alkyl group. The alkyl group having a carboxyl group, a sulfo group, or a phosphonoxy group as the substituent only needs to have at least one carboxyl group, sulfo group, or phosphonoxy group. It is synonymous with the carboxyl group, sulfo group and phosphonoxy group represented by W in formula (III), and the preferred range is also the same. The alkyl group having a carboxyl group, a sulfo group, or a phosphonoxy group as the substituent may be substituted with any other substituent, and the substituent is any of the substituents exemplified as the substituent group D described later. Can be applied. The alkoxy group having a carboxyl group, a sulfo group or a phosphonoxy group as a substituent represented by W ¹ or W ² may be linear or branched, and preferably has 1 to 20 carbon atoms. An alkoxy group, more preferably an alkoxy group of 1 to 8, and particularly preferably an alkoxy group of 1 to 4. The alkoxy group having a carboxyl group, a sulfo group, or a phosphonoxy group as the substituent only needs to have at least one carboxyl group, a sulfo group, or a phosphonoxy group. As the carboxyl group, the sulfo group, and the phosphonoxy group, It is synonymous with the carboxyl group, sulfo group and phosphonoxy group represented by W in formula (III), and the preferred range is also the same. The alkoxy group having a carboxyl group, a sulfo group, or a phosphonoxy group may be substituted with other substituents, and any of the substituents exemplified as the substituent group D described later can be applied as the substituent. . The alkylamino group having a carboxyl group, a sulfo group or a phosphonoxy group as a substituent represented by W ¹ or W ² may be linear or branched, and preferably has 1 to 20 carbon atoms. More preferably 1 to 8 alkylamino groups, and still more preferably 1 to 4 alkylamino groups. The alkylamino group having a carboxyl group, a sulfo group, or a phosphonoxy group may have at least one carboxyl group, a sulfo group, or a phosphonoxy group. Examples of the carboxyl group, the sulfo group, and the phosphonoxy group include those represented by the above formula ( It is synonymous with the carboxyl group, sulfo group and phosphonoxy group represented by W in III), and the preferred range is also the same. The alkylamino group having a carboxyl group, a sulfo group, or a phosphonoxy group may be substituted with other substituents, and any of the substituents exemplified as Substituent Group D described later is applied as the substituent. it can.

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 the cation represented by M, for example, protonium ion, alkali metal ion (lithium ion, sodium ion, potassium ion, etc.), alkaline earth metal ion (barium ion, calcium ion, etc.), ammonium ion, etc. are preferably applied. . Of these, proton ions, lithium ions, sodium ions, potassium ions, and ammonium ions are particularly preferable.

Next, the formula (III) -b will be described.
R ⁶ has the same meaning as R ⁰ in formula (III), and its preferred range is also the same. L ² 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, more 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, more preferably a benzene ring or a naphthalene ring. As a carboxyl group (—COOH) or a salt thereof represented by W ³ , a sulfo group (—SO ₃ H) or a salt thereof, a phosphonoxy group {—OP (═O) (OH) ₂ } or a salt thereof, or a substituent The alkyl group, alkoxy group, or alkylamino group having a carboxyl group, a sulfo group or a phosphonoxy group is a carboxyl group (—COOH) represented by W ¹ and W ² in the formula (III) -a or a salt thereof, sulfo Group (—SO ₃ H) or a salt thereof, phosphonoxy {—OP (═O) (OH) ₂ } or a salt thereof, or an alkyl group, an alkoxy group, or an alkyl having a carboxyl group, a sulfo group, or a phosphonoxy group as a substituent It is synonymous with an amino group and its preferable range is also 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. Or an alkylamino group having a salt thereof, 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 the cation represented by M, for example, protonium ion, alkali metal ion (lithium ion, sodium ion, potassium ion, etc.), alkaline earth metal ion (barium ion, calcium ion, etc.), ammonium ion, etc. 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, more 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, still more preferably 2 to 8 carbon atoms, Argyl group, 3-pentynyl group and the like), an aryl group (preferably an aryl group having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, and further preferably 6 to 12 carbon atoms). 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 further 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, still more 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, still more preferably 6 to 12 carbon atoms, and examples thereof include a phenyloxy group and a 2-naphthyloxy group. An acyl group (preferably an acyl group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and still more preferably 1 to 12 carbon atoms, such as an acetyl group, a benzoyl group, a formyl group, and a pivaloyl group. Etc.), an alkoxycarbonyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, still more preferably A C2-C12 alkoxycarbonyl group, for example, a methoxycarbonyl group, an ethoxycarbonyl group, and the like; an aryloxycarbonyl group (preferably having a carbon number of 7-20, more preferably having a carbon number of 7-16, even more preferably Is an aryloxycarbonyl group having 7 to 10 carbon atoms, such as a phenyloxycarbonyl group, and an acyloxy group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, and still more preferably carbon atoms). An acyloxy group having a number of 2 to 10, and examples thereof include 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, still more 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, still more 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, still more preferably 7 to 12 carbon atoms, such as a phenyloxycarbonylamino group) A sulfonylamino group (preferably having 1 to 20 carbon atoms) Preferably it is a C1-C16, More preferably, it is a C1-C12 sulfonylamino group, for example, a methanesulfonylamino group, a benzenesulfonylamino group, etc.), a sulfamoyl group (preferably C0-20). More preferably, it is a sulfamoyl group having 0 to 16 carbon atoms, more 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 still more preferably 1 to 12 carbon atoms, such as an unsubstituted carbamoyl group, a methylcarbamoyl group, or a diethylcarbamoyl group. Group, phenylcarbamoyl group, etc.),

An alkylthio group (preferably an alkylthio group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, still more preferably 1 to 12 carbon atoms, such as a methylthio group and an ethylthio group), an arylthio group ( Preferably it is a C6-C20, More preferably, it is a C6-C16, More preferably, it is a 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, still more preferably 1 to 12 carbon atoms, and examples thereof include a mesyl group and a tosyl group), a sulfinyl group (preferably having a carbon number of 1 to 20, and more. A sulfinyl group having 1 to 16 carbon atoms, more preferably 1 to 12 carbon atoms, is preferable. A ureido group (preferably a benzenesulfinyl group), a ureido group (preferably a ureido group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and still more preferably 1 to 12 carbon atoms. 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, and further preferably having 1 to 12 carbon atoms) Group such as diethyl phosphoramide group and phenylphosphoric acid amide group), hydroxy group, mercapto group, halogen atom (eg fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group Group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, heterocyclic group (preferably A heterocyclic group having 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, such as a heterocyclic group having a hetero atom such as a nitrogen atom, an oxygen atom, or a sulfur atom, such as an imidazolyl group, a pyridyl group, or a quinolyl group; Group, 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, More preferably, it is 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.

  The fluorine-containing compound of the present invention preferably has a polymerizable group as a substituent in order to fix the alignment state of the discotic liquid crystalline compound.

  Specific examples of the fluorine-containing compound represented by the formula (III) 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.

  The preferable range of the content of the fluorine-containing compound in the liquid crystal composition varies depending on the use, but 0.005 to 0.005 in the liquid crystal composition (a composition excluding the solvent in the case of a coating liquid). The content is preferably 8% by mass, more preferably 0.01 to 5% by mass, and still more preferably 0.05 to 1% by mass.

[Coating solvent]
As a solvent used for preparing the coating solution, an organic solvent is preferably used. Examples of organic solvents include amides (eg N, N-dimethylformamide), sulfoxides (eg dimethyl sulfoxide), heterocyclic compounds (eg pyridine), hydrocarbons (eg benzene, hexane), alkyl halides (eg , Chloroform, dichloromethane), esters (eg, methyl acetate, butyl acetate), ketones (eg, acetone, methyl ethyl ketone), ethers (eg, tetrahydrofuran, 1,2-dimethoxyethane). Alkyl halides and ketones are preferred. Two or more organic solvents may be used in combination. Application | coating of a coating liquid can be implemented by a well-known method (For example, extrusion coating method, direct gravure coating method, reverse gravure coating method, die coating method).

[Polymerization initiator]
The vertically aligned liquid crystal compound is fixed while maintaining the alignment state. The immobilization is preferably performed by a polymerization reaction of the polymerizable group (P) introduced into the liquid crystal compound. The polymerization reaction includes a thermal polymerization reaction using a thermal polymerization initiator and a photopolymerization reaction using a photopolymerization initiator. A photopolymerization reaction is preferred. Examples of the photopolymerization initiator include α-carbonyl compounds (described in US Pat. Nos. 2,367,661 and 2,367,670), acyloin ether (described in US Pat. No. 2,448,828), α-hydrocarbon substituted aromatics. Group acyloin compounds (described in US Pat. No. 2,722,512), polynuclear quinone compounds (described in US Pat. Nos. 3,046,127 and 2,951,758), combinations of triarylimidazole dimers and p-aminophenyl ketone (US patents) No. 3549367), acridine and phenazine compounds (JP-A-60-105667, US Pat. No. 4,239,850) and oxadiazole compounds (US Pat. No. 4,221,970).

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. The light irradiation for the polymerization of the discotic liquid crystalline compound preferably uses ultraviolet rays. The irradiation energy is preferably ^{20mJ / cm 2 ~50J / cm 2} , further preferably 100 to 800 mJ / cm ^2. In order to accelerate the photopolymerization reaction, light irradiation may be performed under heating conditions. The thickness of the retardation layer is preferably 0.1 to 10 μm, more preferably 0.5 to 5 μm, and most preferably 1 to 5 μm.

[Other additives for optically anisotropic layer]
Along with the liquid crystal compound, a plasticizer, a surfactant, a polymerizable monomer, and the like can be used together to improve the uniformity of the coating film, the strength of the film, the orientation of the liquid crystal compound, and the like. These materials are preferably compatible with the liquid crystal 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 polymerizable group-containing liquid crystalline 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 preferably 1 to 50% by mass and more preferably 5 to 30% by mass with respect to the discotic liquid crystalline compound.

  Examples of the surfactant include conventionally known compounds, and fluorine compounds are particularly preferable. Specifically, for example, compounds described in paragraph Nos. [0028] to [0056] in JP 2001-330725 A, paragraph Nos. [0069] to [0126] in JP 2003-295212 A, and the like. And the compounds described in the above.

The polymer used together with the liquid crystal compound is preferably capable of thickening the coating solution. A cellulose ester can be mentioned as an example of a polymer. Preferable examples of the cellulose ester include those described in paragraph [0178] of JP-A No. 2000-155216. The addition amount of the polymer is preferably in the range of 0.1 to 10% by mass, and in the range of 0.1 to 8% by mass with respect to the liquid crystal compound so as not to inhibit the alignment of the liquid crystal compound. It is more preferable.
The discotic nematic liquid crystal phase-solid phase transition temperature of the liquid crystal compound is preferably 70 to 300 ° C, more preferably 70 to 170 ° C.

[Alignment film]
In the present invention, the liquid crystalline composition is preferably applied to the surface of the alignment film to align the molecules of the liquid crystalline compound. Since the alignment film has a function of defining the alignment direction of the discotic liquid crystalline compound, it is preferably used for realizing a preferred embodiment of the present invention. However, if the alignment state is fixed after aligning the liquid crystalline compound, the alignment film plays a role, and is not necessarily essential as a component of the present invention. That is, it is possible to produce the polarizing plate of the present invention 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 (for example, ω-tricosanoic acid) formed by rubbing treatment of an organic compound (preferably 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 is preferably formed by polymer rubbing treatment.

  Examples of the polymer include methacrylate copolymers, styrene copolymers, polyolefins, polyvinyl alcohol and modified polyvinyl alcohol, poly (N-methylolacrylamide) described in paragraph [0022] of JP-A-8-338913, for example. ), Polyester, polyimide, vinyl acetate copolymer, carboxymethyl cellulose, polycarbonate and the like. Silane coupling agents can be used as the polymer. Water-soluble polymers (for example, poly (N-methylolacrylamide), carboxymethylcellulose, gelatin, polyvinyl alcohol, and modified polyvinyl alcohol) are preferable, gelatin, polyvinyl alcohol, and modified polyvinyl alcohol are more preferable, and polyvinyl alcohol and modified polyvinyl alcohol are most preferable. .

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

In the alignment film of the present invention, a side chain having a crosslinkable functional group (for example, a double bond) is bonded to the main chain, or a crosslinkable functional group having a function of aligning a liquid crystal compound is introduced into the side chain. It is preferable to do. 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.
When the side chain having a crosslinkable functional group is bonded to the main chain of the alignment film polymer or the crosslinkable functional group is introduced into the side chain having the function of aligning the liquid crystal compound, the alignment film polymer and the optically anisotropic film The polyfunctional monomer contained in the conductive layer 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] of JP-A No. 2000-155216.

  Apart from the crosslinkable functional group, the alignment film polymer can also be crosslinked using a crosslinking agent. 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] of JP-A No. 2002-62426. Aldehydes having high reaction activity are preferred, and glutaraldehyde is more preferred.

  0.1-20 mass% is preferable with respect to a polymer, and, as for the addition amount of a crosslinking agent, 0.5-15 mass% is more preferable. 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 for a long time in a liquid crystal display device or left in a high-temperature and high-humidity atmosphere for a long time, sufficient durability without generation of reticulation can be obtained.

  The alignment film can be formed by, for example, applying a solution containing the polymer, the crosslinking agent, and the additive, which is an alignment film forming material, onto a transparent support, followed by heat drying (crosslinking) and rubbing treatment. it can. As described above, the crosslinking reaction may be performed at an arbitrary 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 liquid is preferably a mixed solvent of an organic solvent (for example, methanol) having a defoaming action and water. The ratio of water: methanol is preferably 0: 100 to 99: 1, and more preferably 0: 100 to 91: 9. Thereby, generation | occurrence | production of a bubble is suppressed and the defect of the layer surface of an alignment film and also an optically anisotropic layer reduces remarkably.

  As a method for applying the alignment film, a spin coating method, a dip coating method, a curtain coating method, an extrusion coating method, a rod coating method or a roll coating method is preferable, and a rod coating method is more preferable. The film thickness after drying is preferably 0.1 to 10 μm. Heating and drying can be performed at 20 ° C to 130 ° C. In order to form sufficient crosslinks, 40 ° C to 120 ° C is preferable, and 50 ° C to 110 ° C is particularly preferable. The drying time can be 1 minute to 36 hours, preferably 1 minute to 30 minutes. The pH is also preferably set to an optimum value for the crosslinking agent to be used. When glutaraldehyde is used, pH 4.5 to 5.5 is preferable, and 5 is more preferable.

  The alignment film is preferably provided on the transparent support. The alignment film can be obtained by rubbing the surface after crosslinking the polymer layer as described above.

  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.

The liquid crystalline composition is applied to the rubbing-treated surface of the alignment film to align the molecules of the discotic liquid crystalline compound. Thereafter, if necessary, the alignment film polymer and the polyfunctional monomer contained in the optically anisotropic layer are reacted, or the alignment film polymer is crosslinked using a crosslinking agent, thereby the optically anisotropic layer. Can be formed.
The thickness of the alignment film is preferably in the range of 0.1 to 10 μm.

[Support]
The retardation plate of the present invention may include a support. By coating the liquid crystalline composition on the support to form an optically anisotropic layer, a self-supporting retardation plate can be produced. Only one layer of optically anisotropic layer may be formed on the support, or two or more optically anisotropic layers may be sequentially laminated on one surface of the support, or both surfaces of the support. An optically anisotropic layer may be formed.

As the support, it is preferable to use a polymer film having a small wavelength dispersion. The support preferably further has small optical anisotropy. The support preferably has a light transmittance of 80% or more (transparent support). Specifically, the small chromatic dispersion means that the ratio of Re ₄₀₀ / Re ₇₀₀ is preferably less than 1.2.

  In order to adjust the retardation plate to satisfy the above formula (1), a support having optical anisotropy may be used. The support used in the retardation plate of the present invention preferably has Re of 0 to 20 nm and Rth of -100 nm to 100 nm, Re of 0 to 10 nm, and Rth of -100 nm to 20 nm. preferable.

  Examples of the polymer include cellulose ester, polycarbonate, polysulfone, polyethersulfone, polyacrylate, polymethacrylate and cyclic polyolefin. Among these, a cellulose ester is preferable and a cellulose acetate is more preferable. Cyclic polyolefins include those obtained by hydrogenating a ring-opening polymer of tetracyclododecenes or a ring-opening copolymer of tetracyclododecenes and norbornenes described in JP-B-2-9619. A polymer having a coalescence as a constituent component can be used from the series of Arton (manufactured by JSR), Zeonex, and Zeonore (manufactured by Nippon Zeon). The polymer film is preferably formed by a solvent cast method.

  The polymer film is preferably formed by a solvent cast method. The thickness of the transparent support is preferably 20 to 500 μm, and more preferably 50 to 200 μm. In order to improve adhesion between the transparent support and the layer (adhesive layer, vertical alignment film or retardation layer) provided thereon, the support is subjected to surface treatment (for example, glow discharge treatment, corona discharge treatment, ultraviolet (UV) Treatment, flame treatment). An adhesive layer (undercoat layer) may be provided on the support. Moreover, in order to give the support body and the long support body the slipperiness in a conveyance process, or to prevent sticking of the back surface and the surface after winding up, the average particle diameter is 10-100 nm inorganic. It is preferable to use a polymer layer in which particles are mixed at a solid content weight ratio of 5% to 40% and formed on one side of the support by coating or co-casting with the support.

  A preferred embodiment of the present invention is an embodiment in which the slow axis of the optically anisotropic layer is not parallel or orthogonal to the longitudinal direction of the support. Specifically, the angle formed by the longitudinal direction of the support and the slow axis of the optically anisotropic layer is preferably 5 to 85 °. The angle of the slow axis of the optically anisotropic layer can be adjusted by the rubbing angle. By making the slow axis of the optically anisotropic layer not parallel or orthogonal to the longitudinal direction of the long support (for example, by forming an alignment film on the support, the surface of the alignment film In the direction of 5 to 85 ° with respect to the longitudinal direction), in the production of an elliptically polarizing plate, it becomes possible to bond a long polarizing film with a roll-to-roll, and the axial angle of the bonding This makes it possible to manufacture elliptical polarizing plates with high accuracy and high productivity.

  The retardation plate of the present invention may include not only an optically anisotropic layer containing a liquid crystalline compound but also a polymer film in order to control optical characteristics. The polymer film is formed from a polymer capable of developing birefringence. As the birefringent polymer film, those having excellent controllability of birefringence characteristics, transparency and heat resistance, and those having low photoelasticity are preferable. In this case, the polymer material to be used is not particularly limited as long as it is a polymer that can achieve uniform uniaxial orientation or biaxial orientation, and is preferably a conventionally known material that can be formed by a solution casting method or an extrusion method. , Norbornene polymer, polycarbonate polymer, polyarylate polymer, polyester polymer, aromatic polymer such as polysulfone, polyolefin such as polypropylene, cellulose acylate, or two or three of these polymers Examples thereof include a polymer obtained by mixing the above.

  The optical anisotropy of the polymer film is preferably obtained by uniaxial or biaxial stretching. Uniaxial stretching is preferably longitudinal uniaxial stretching using the difference in peripheral speed between two or more rolls, or tenter stretching in which both sides of the polymer film are gripped and stretched in the width direction. Biaxial optical anisotropy may be developed by stretching the polymer film in the longitudinal direction and the transverse direction. In addition, using two or more polymer films, the optical properties of the entire two or more films may satisfy the above conditions. The polymer film is preferably produced by a solvent cast method in order to reduce unevenness in birefringence. The thickness of the polymer film is preferably 20 to 400 nm, and more preferably 30 to 100 nm.

  A polymer film having an optical characteristic in which Rth has a negative value is a method in which a heat-shrinkable film is bonded and heated to apply a predetermined tension while stretching the polymer film in the thickness direction of the film (Japanese Patent Laid-Open No. 2000-2000). 206328, JP 2000-304925) or a method of applying a vinyl carbazole polymer and drying (JP 2001-091746).

[Polarizer]
The polarizing plate of the present invention is formed by laminating the retardation plate of the present invention and a polarizing film. The retardation plate of the present invention can also function as a protective film for a polarizing film. The support preferably functions as a protective film for the polarizing film and is provided as a retardation plate-integrated polarizing plate. Further, the retardation plate of the present invention and a polarizing plate having a protective film may be bonded together.

  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 absorption axis of the polarizing film corresponds to the stretching direction of the film. Accordingly, the polarizing film stretched in the longitudinal direction (transport direction) has an absorption axis parallel to the longitudinal direction, and the polarizing film stretched in the lateral direction (perpendicular to the transport direction) is perpendicular to the longitudinal direction. Has an absorption axis.

  The preferable manufacturing method of the polarizing plate of this invention includes the process by which a polarizing film and a phase difference plate are each laminated | stacked continuously in the elongate state. The long polarizing plate is cut according to the screen size of the liquid crystal display device used.

  If a linearly polarizing film and a retardation plate are combined to form an elliptically polarizing plate, it can be easily incorporated into a reflective and transflective liquid crystal display device. It can also be used as an antireflection film for organic EL display devices. In addition, since a long cholesteric liquid crystalline film produced separately can be further laminated on the long elliptical polarizing plate, it is easy to produce a highly productive brightness enhancement film.

  The polarizing film generally has a protective film. In the present invention, when an optically anisotropic layer made of a liquid crystalline compound is formed on a transparent support, the transparent support can function as a protective film. In the case of using a protective film for the polarizing film separately from the support, it is preferable to use a cellulose ester film or norbornene polymer film having high optical isotropy as the protective film.

[Liquid Crystal Display]
The liquid crystal display device of the present invention has at least the retardation plate, and includes a reflection type, a semi-transmission type, a transmission type liquid crystal display device and the like. A liquid crystal display device generally includes a polarizing plate, a liquid crystal cell, and a retardation plate, a reflective layer, a light diffusion layer, a backlight, a front light, a light control film, a light guide plate, a prism sheet, a color filter, etc. Although comprised from a member, in this invention, there is no restriction | limiting in particular except the point which makes it essential to use the said phase difference plate. The use position of the retardation plate is not particularly limited, and may be one or more. The liquid crystal cell is not particularly limited, and a general liquid crystal cell such as a liquid crystal layer sandwiched between a pair of transparent substrates provided with electrodes can be used. The transparent substrate constituting the liquid crystal cell is not particularly limited as long as the liquid crystal material constituting the liquid crystal layer is aligned in a specific alignment direction. Specifically, a transparent substrate in which the substrate itself has a property of orienting liquid crystals, a transparent substrate in which an alignment film having the property of orienting liquid crystals is provided, but the substrate itself lacks the alignment ability. Either can be used. Moreover, a well-known thing can be used for the electrode of a liquid crystal cell. Usually, it can be provided on the surface of the transparent substrate in contact with the liquid crystal layer, and when a substrate having an alignment film is used, it can be provided between the substrate and the alignment film. The material exhibiting liquid crystallinity for forming the liquid crystal layer is not particularly limited, and examples thereof include various ordinary low-molecular liquid crystalline compounds, high-molecular liquid crystalline compounds, and mixtures thereof that can constitute various liquid crystal cells. Moreover, a pigment | dye, a chiral agent, a non-liquid crystalline compound, etc. can also be added to these in the range which does not impair liquid crystallinity.

  In addition to the electrode substrate and the liquid crystal layer, the liquid crystal cell may include various components necessary for forming various types of liquid crystal cells described later. As the liquid crystal cell system, a TN (Twisted Nematic) system, a STN (Super Twisted Nematic) system, an ECB (Electrically Controlled Birefringence) system, an IPS (In-Plane Switching) system, a VA (In-Plane Switching) system, a VA (In-Plane Switching) system, a VA (In-Plane Switching) system, a VA (In-Plane Switching) system, Alignment), PVA (Patterned Vertical Alignment), OCB (Optically Compensated Birefringence), HAN (Hybrid Aligned Nematic), ASM crocell) method, halftone gray scale method, domain division method, or display method using ferroelectric liquid crystal or antiferroelectric liquid crystal. The driving method of the liquid crystal cell is not particularly limited, and a passive matrix method used for STN-LCD and the like, and an active matrix method using an active electrode such as a TFT (Thin Film Transistor) electrode and a TFD (Thin Film Diode) electrode, Any driving method such as a plasma addressing method may be used. A field sequential method that does not use a color filter may be used.

  The polarizing plate in the present invention is preferably used for a reflective, transflective, and transmissive liquid crystal display device. Moreover, the polarizing plate in this invention is preferably used also as a brightness improvement film | membrane by combining with a cholesteric liquid crystal film. The reflective liquid crystal display device has a configuration in which a reflector, a liquid crystal cell, and a polarizing plate are laminated in this order. The retardation plate is disposed between the reflecting plate and the polarizing film (between the reflecting plate and the liquid crystal cell or between the liquid crystal cell and the polarizing film). The reflector may share the liquid crystal cell and the substrate. The transflective liquid crystal display device includes an electro-liquid crystal cell, a polarizing plate disposed closer to the viewer than the liquid crystal cell, and at least one retardation plate disposed between the polarizing plate and the liquid crystal cell. And at least a transflective layer disposed behind the liquid crystal layer as viewed from the viewer, and at least one retardation plate and a polarizing plate behind the transflective layer as viewed from the viewer. Have In this type of liquid crystal display device, it is possible to use both a reflection mode and a transmission mode by installing a backlight.

  In the liquid crystal display device, the polarizing plate combined with the retardation plate of the present invention functions as an elliptically polarizing plate or a circularly polarizing plate. The liquid crystal display device according to the present invention uses the retardation plate of the present invention at least at one location.

  The retardation plate and polarizing plate of the present invention are not limited to the above uses, and can be used for other various uses. For example, it can be used for an antireflection film such as a host-guest type liquid crystal display device, a touch panel, an electroluminescence (EL) element, a reflection type polarizing plate, and the like.

  The features of the present invention will be described more specifically with reference to examples and comparative examples. The materials, amounts used, ratios, processing details, 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.

  The features of the present invention will be described more specifically with reference to examples and comparative examples. The materials, amounts used, ratios, processing details, 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]
<Production of cellulose acetate film>
(Preparation of cellulose acetate solution)
The following composition was put into a mixing tank and stirred to dissolve each component to prepare a cellulose acetate solution A.
Composition of cellulose acetate solution A ――――――――――――――――――――――――――――――――――――
Cellulose acetate with an acetyl substitution degree of 2.94 100.0 parts by mass Methylene chloride (first solvent) 402.0 parts by mass Methanol (second solvent) 60.0 parts by mass ――――――――――――― ――――――――――――――――――――――

(Preparation of matting agent solution)
20 parts by mass of silica particles having an average particle diameter of 16 nm (AEROSIL R972, manufactured by Nippon Aerosil Co., Ltd.) and 80 parts by mass of methanol were mixed well for 30 minutes to obtain a silica particle dispersion. This dispersion was put into a disperser together with the following composition, and further stirred for 30 minutes or more to dissolve each component to prepare a matting agent solution.
Matting agent solution composition ――――――――――――――――――――――――――――――――――
Silica particle dispersion liquid having an average particle diameter of 16 nm 10.0 parts by mass Methylene chloride (first solvent) 76.3 parts by mass Methanol (second solvent) 3.4 parts by mass Cellulose acetate solution A 10.3 parts by mass ―――――――――――――――――――――――――――――

(Preparation of additive solution)
The following composition was put into a mixing tank and stirred while heating to dissolve each component to prepare a cellulose acetate solution.
Additive solution composition ――――――――――――――――――――――――――――――
The following optical anisotropy reducing agent 49.3 parts by mass The following wavelength dispersion adjusting agent 4.9 parts by mass Methylene chloride (first solvent) 58.4 parts by mass Methanol (second solvent) 8.7 parts by mass Cellulose acetate solution A 12.8 parts by mass ――――――――――――――――――――――――――――――

Optical anisotropy reducing agent

Chromatic dispersion modifier

(Production of cellulose acetate film)
94.6 parts by mass of the cellulose acetate solution A, 1.3 parts by mass of the matting agent solution, and 4.1 parts by mass of the additive solution were mixed after filtration, and cast using a band casting machine. In the above composition, the mass ratio of the optical anisotropy reducing agent and the wavelength dispersion adjusting agent to cellulose acetate was 12% by mass and 1.2% by mass, respectively. The film was peeled from the band with a residual solvent amount of 30% by mass and dried at 140 ° C. for 40 minutes to produce a long cellulose acetate film having a thickness of 80 μm. The in-plane retardation (Re) of the obtained film was 1 nm (the slow axis was a direction perpendicular to the film longitudinal direction), and the thickness direction retardation (Rth) was −1 nm.

<Production of retardation plate>
(Formation of alignment film)
After saponifying the surface of the produced cellulose acetate film, an alignment film coating solution having the following composition was continuously applied with a # 14 wire bar. 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 continuously rubbed in a direction of 45 ° with respect to the longitudinal direction of the film to form an alignment film.
Composition of alignment film coating solution ――――――――――――――――――――――――――
The following modified polyvinyl alcohol 10 parts by weight Water 371 parts by weight Methanol 119 parts by weight Glutaraldehyde 0.5 parts by weight ――――――――――――――――――――――――――――

Modified polyvinyl alcohol

(Creation of optically anisotropic layer)
A coating liquid (liquid crystalline composition) containing a discotic liquid crystalline compound having the following composition was continuously applied to the prepared alignment film with a # 3.6 wire bar. In order to dry the solvent of the coating solution and to mature the orientation of the discotic liquid crystal compound, the coating liquid was heated with warm air at 100 ° C. for 30 seconds and further with warm air at 140 ° C. for 60 seconds. Subsequently, the alignment of the liquid crystal compound was fixed by UV irradiation to form an optically anisotropic layer, and the retardation film 1 (Comparative Example) was produced.

  Instead of the discotic liquid crystalline compound, the following rod-like liquid crystalline compound (A) was used, and ethylene oxide-modified trimethylolpropane triacrylate (V # 360, manufactured by Osaka Organic Chemical Co., Ltd.) was changed to 1 part by mass. A retardation plate 2 (comparative example) was produced in the same manner as the retardation plate 1 except that the orientation aging temperature was optimized.

  The discotic liquid crystalline compound and the rod-shaped liquid crystalline compound were mixed in the ratio shown in Table 1, and the other retardation plates 3 to 5 (invention) were produced in the same manner as the retardation plate 2 except for the above.

Composition of coating solution for optically anisotropic layer ―――――――――――――――――――――――――――――――――
The following discotic liquid crystalline compound 100 parts by mass Ethylene oxide modified trimethylolpropane triacrylate (V # 360, manufactured by Osaka Organic Chemical Co., Ltd.) 9 parts by mass Photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy) 3 parts by mass Sensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) 1 part by mass The following fluoropolymer (A) 0.2 part by mass The following fluoropolymer (B) 0.2 part by mass The following pyridinium salt (B ) 0.5 parts by mass Methanol 30 parts by mass Methyl ethyl ketone 165 parts by mass ―――――――――――――――――――――――――――――――――

Discotic liquid crystalline compounds

Rod-like liquid crystalline compound (A)

Fluoropolymer (A)

Fluoropolymer (B)

Pyridinium salt (C)

  Using an automatic birefringence meter (KOBRA-21ADH, manufactured by Oji Scientific Instruments Co., Ltd.), Re (0), Re (40) and Re (-40) at 589 nm of the prepared retardation plates 1 to 5 Were measured to determine Rth and Nz (Table 1). From the optical characteristic value of the phase difference plate 1, it can be seen that the average tilt angle of the disc surface of the discotic liquid crystal molecules with respect to the film surface is approximately 90 °, and the discotic liquid crystal compound is aligned perpendicular to the film surface. It was confirmed that Further, it can be seen from the optical characteristic values of the retardation plate 2 that the angle formed by the director of the rod-like liquid crystalline molecules with the film surface is approximately 90 °, and the rod-like liquid crystalline molecules are aligned perpendicular to the film surface. It was confirmed that In any case, the direction of the slow axis was parallel to the rubbing direction of the alignment film, and the angle formed with the longitudinal direction of the support was 45 °.

  Moreover, since the optical characteristic value of the phase difference plates 3 to 5 is close to the value calculated from the discotic liquid crystal compound content ratio and the rod-like liquid crystal compound content ratio that are aligned perpendicular to the film surface, In all cases, it was considered that the mixed discotic liquid crystal compound and rod-shaped liquid crystal compound were aligned perpendicular to the film surface. Also in these retardation plates, the direction of the slow axis was parallel to the rubbing direction of the alignment film, and the angle formed with the longitudinal direction of the support was 45 °.

In Table 1, DLC ratio (1) indicates a discotic liquid crystal compound content ratio (parts by mass), and RLC ratio (2) indicates a rod-like liquid crystal compound content ratio (parts by mass).

[Example 2]
<Preparation of polarizing plates 1A to 5A>
A roll-shaped polyvinyl alcohol film having a thickness of 80 μm continuously dyed in an aqueous iodine solution was stretched 5 times in the transport direction and dried to obtain a long polarizing film. On one surface of the polarizing film, the surface on which the optically anisotropic layer of the prepared retardation plate 1 is not formed, and on the other surface, a viewing angle widening film (Wide View Film WVA manufactured by Fuji Photo Film Co., Ltd.) −07D) was continuously bonded using a polyvinyl alcohol-based adhesive to produce a long polarizing plate 1A. The absorption axis of the polarizing film was parallel to the film longitudinal direction, and the slow axis of the wide view film was orthogonal to the film longitudinal direction. The angle formed by the absorption axis of the polarizing film and the slow axis of the retardation plate 1 was 45.0 °.
Similarly, the retardation plates 2 to 5, the polarizing film and the viewing angle widening film were continuously bonded to produce the long polarizing plates 2 </ b> A to 5 </ b> A, respectively. The absorption axis of the polarizing film was parallel to the film longitudinal direction, and the slow axis of the wide view film was orthogonal to the film longitudinal direction. The angle formed by the absorption axis of the polarizing film and the slow axis of the retardation plate 2 was 45.0 °.

<Preparation of Polarizing Plates 1B-5B>
A long cholesteric liquid crystal film was prepared in the same manner as described in the examples of JP-A-2003-337221. The surface opposite to the wide view film of the produced polarizing plate 1A and the cholesteric liquid crystal film were continuously bonded to produce a long polarizing plate 1B.
Similarly, polarizing plates 2A to 5A and a cholesteric liquid crystal film were continuously bonded to produce long polarizing plates 2B to 5B, respectively.

[Example 3]
<Production of liquid crystal display device>
Of the pair of polarizing plates provided in a liquid crystal display device (AQUAS LC20C1S, manufactured by Sharp Corporation) using a TN type liquid crystal cell, only the polarizing plate on the backlight side is peeled off, and the above-prepared polarizing plate 1B is used instead. And 3B-5B was affixed through the adhesive so that a wide view film might become a liquid crystal cell side. The transmission axis of the polarizing plate on the viewer side and the transmission axis of the polarizing plate on the backlight side were arranged to be in the O mode.
About the produced liquid crystal display device, the viewing angle was measured from black display (L1) to white display (L8) using a measuring machine (EZ-Contrast 160D, manufactured by ELDIM). Although the viewing angle characteristics were almost the same when the polarizing plates 1B and 3B to 5B were used, the front luminance at the time of white display was the polarizing plate 3B of the present invention compared to the case where the polarizing plate 1B was used. When 4B and 5B were used, they were 1.1 times, 1.2 times, and 1.3 times, respectively. Further, when the white display was observed from an oblique direction, the polarizing plate 3 compared to the polarizing plate 2B.
Compared with the case where B-5B was used, coloring was small.

Claims (4)

A retardation plate having an optically anisotropic layer containing at least one liquid crystalline compound having a positive optical anisotropy and at least one liquid crystalline compound having a negative optical anisotropy, when defining the Nz as the following equation (1), the Nz is rather smaller than 0, the liquid crystalline compound optical anisotropy is positive is a rod-like liquid crystal compound, the optical anisotropy is negative The liquid crystalline compound is a discotic liquid crystalline compound, and the alignment state is fixed so that the disc surface of the discotic liquid crystalline compound is substantially perpendicular to the optically anisotropic layer surface, A retardation plate in which an alignment state is fixed so that a major axis direction of the rod-like liquid crystal compound is substantially perpendicular to a surface of the optically anisotropic layer.
Formula (1)
Nz = 0.5 + Rth / Re
(In the formula (1), Re and Rth respectively represent the in-plane retardation value of the retardation film and the retardation value in the thickness direction.) The optically anisotropic layer is provided on a support, the in-plane retardation (Re) of the support is 0 to 20 nm, and the thickness direction retardation (Rth) is −100 nm to 100 nm. The phase difference plate according to claim 1 . A polarizing plate comprising the retardation plate according to claim 1 or 2 and a polarizing film. A liquid crystal display device comprising the retardation plate according to claim 1 or 2 , or the polarizing plate according to claim 3 and a liquid crystal cell.