JP2008145901A - Material for anisotropic film, composition for anisotropic film, anisotropic film and optical element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a material for an anisotropic film having no absorption in the visible light region and showing good chromonic liquid crystallinity. <P>SOLUTION: A water-soluble compound represented by formula (1) is used, wherein X<SP>1</SP>, Y<SP>1</SP>and Z<SP>1</SP>represent NR<SP>1</SP>R<SP>2</SP>, SR<SP>3</SP>or OR<SP>4</SP>, R<SP>1</SP>-R<SP>4</SP>represent H, a 1-18C alkyl group which may have a substituent, a 2-18C alkenyl group which may have a substituent, a 6-18C aromatic hydrocarbon group which may have a substituent, a 3-12C alicyclic hydrocarbon group which may have a substituent or a 3-18C heterocyclic group which may have a substituent, and R<SP>1</SP>and R<SP>2</SP>may bond to each other to form a ring with N atoms. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an anisotropic film material, an anisotropic film composition using the material, an anisotropic film, and an optical element.

  As shown in Non-Patent Document 1, various retardation films are used in flat panel displays (FPD) such as liquid crystal displays (LCD). Here, as defined in Non-Patent Document 2, the phase difference film divides monochromatic polarized light into two components without changing the intensity or degree of polarization, and delays the phase of one component relative to the other, Next, a film-like optical element having an action of combining these two components.

  In particular, the LCD is provided with a liquid crystal layer and a polarizing plate having optical anisotropy, and thus has a strong viewing angle dependency. Therefore, in order to compensate for this, usually, the retardation in the film surface and the retardation in the film thickness direction are precisely controlled in the wavelength region of visible light using a retardation film.

  The optical mechanism of the retardation film includes a birefringence type and a reflection type. Examples of the former include polymer films and liquid crystal compound films imparted with refractive index anisotropy by mechanical deformation / flow such as stretching or coating, or irradiation with polarized ultraviolet rays. On the other hand, examples of the latter include a Fresnel prism and a Mooney prism. Among these, the birefringence type is industrially used from the viewpoint of cost, simplicity of the optical system, and response to enlargement.

  Among birefringent polarizing films, those using a liquid crystal compound can spontaneously control the refractive index anisotropy of the film depending on its molecular structure, and do not require precise process control. Therefore, for example, various liquid crystal compounds such as thermotropic liquid crystal compounds as described in Non-Patent Documents 3 and 4 and chromonic liquid crystal compounds as described in Patent Documents 1 to 3 have been proposed as the retardation film compounds.

  Thermotropic liquid crystal compounds have a molecular structure in which alkyl chains are bonded to the ends of rod-shaped mesogens or around disk-shaped mesogens. In addition to the mesogenic shape anisotropy, mesogens and alkyl chains are microphase-separated. It exhibits liquid crystal properties. Since this alkyl chain has a lower surface energy than mesogens, it easily segregates at the interface between the film and air. Therefore, the control of the refractive index anisotropy of a retardation film using a thermotropic liquid crystal compound is effective for this segregation. Limited to a certain range.

  On the other hand, the chromonic liquid crystal has a molecular structure in which a solvophilic functional group is bonded around a disc-shaped or strip-shaped mesogen as described in Non-Patent Document 5, and is an aggregate formed in a solvent. In addition to shape anisotropy, liquid crystallinity is exhibited by microphase separation of the solvent and the aggregate. There is no great difference in surface energy between the solvophilic functional group and mesogen, and segregation of the solvophilic functional group and mesogen can be suppressed by selecting the solvent. Therefore, the refractive index anisotropy of the retardation film using the chromonic liquid crystal can be freely controlled by changing the shape of the mesogen.

  So far, it has been motivated by research on polarizing films of Zocher (Non-patent Document 6) and Dreyer (Non-patent Document 7) using dyes having chromonic liquid crystallinity, as described in Patent Documents 1 to 3. Invented retardation films using various chromonic liquid crystal compounds.

S. M. Kelly, "Flat Panel Displays-Advanced Organic Materials", The Royal Society of Chemistry, (2000) W.A.Shurcliff ,, "Polarized Light − Production and Use" Harvard Univ. Press, (1962) P. V. Witte, J. V. Harren, J. Tuijtelaars, S. Stallinga and J. Lub, Jpn. J. Appl. Phys. Vol. 38, 748-754, (1999) H. Mori, Y. Itoh, Y. Nishimura, T. Nakamura, and Y. Sinagawa, AM-LCD'96 / IDW'96 Proceedings of the Third International Display Workshop, Kobe, Vol.1, p.189-191, (1996) A. S. Vasilevskaya, E. V. Generalova and A. S. Sonin, "Chromonic mesophases", Russian Chemical Reviews, 58 (9), 904, (1989). H. Zocher, "Spontaneous structure formation in sols; a new kind of anisotropic liquid media", Z. anorg.allgem. Chem. Vol.147, 91-110, (1925) J. F. Dreyer, "The fixing of molecular orientation", Phys. Colloid Chem., 52, 808, (1948) JP-A-52-2541 JP-T-2001-515945 International Publication No. WO2002 / 048759 Pamphlet

  Patent Document 1 proposes a retardation film using 1,3-bis (carboxy-substituted aromatic amino) -triazinyl 5-pyridinium hydroxide or a salt thereof. Certainly, an aqueous solution of the compound exhibits chromonic liquid crystallinity, and the coating film functions as a retardation film. In addition, the compound seems to form a stable aggregate by the interaction between the pyridinium salt and the carboxy-substituted aromatic ring, and exhibits liquid crystallinity at a relatively low concentration of 10% by weight or less. On the other hand, pyridinium salts are unstable with respect to alkalis and high temperatures, and may be decomposed during preparation and storage of the liquid crystal solution, resulting in coloration or loss of liquid crystallinity.

In Patent Document 2, attempts are made to improve the stability of pyridinium salts by changing the counter ion of the same compound or introducing a substituent, but the effect is insufficient.
Further, Patent Document 3 proposes a retardation film using a compound having two triazine rings without using an alkali or heat-labile pyridinium salt. However, since there are many portions connecting two triazine rings and an aromatic ring, the mesogen tends to impair the planarity. Therefore, it is difficult to show chromonic liquid crystal properties, and it is unsuitable as a retardation film compound.

  The present invention has been made in view of the above problems, and has an anisotropic film material that does not absorb in the visible light region and exhibits good chromonic liquid crystal properties, and an anisotropy using the material. An object is to provide a film composition, an anisotropic film, and an optical element.

  As a result of intensive studies to solve the above problems, the inventors of the present invention have an anisotropic film material composed of a water-soluble compound represented by the following formula (1), which has good chromonic liquid crystallinity, The inventors have found that there is no absorption in the visible light region and have completed the present invention.

（式（１）において、Ｘ¹、Ｙ¹およびＺ¹は、それぞれ独立に、ＮＲ¹Ｒ²、ＳＲ³またはＯＲ⁴を表し、Ｒ¹〜Ｒ⁴は、それぞれ独立に、水素原子、置換基を有していてもよい炭素数１〜１８のアルキル基、置換基を有していてもよい炭素数２〜１８のアルケニル基、置換基を有していてもよい炭素数６〜１８の芳香族炭化水素基、置換基を有していてもよい炭素数３〜１２の脂環炭化水素基、または、置換基を有していてもよい炭素数３〜１８の複素環基を表す。また、Ｒ¹およびＲ²は結合してＮ原子とともに環を形成していてもよい。） That is, the gist of the present invention resides in an anisotropic film material comprising a water-soluble compound represented by the following formula (1) (claim 1).

In (Equation ^{(1), X 1, Y} 1 and Z ¹ each independently represents an NR ¹ R ^2, SR ³ or OR ^4, R ¹ ~R ⁴ are each independently a hydrogen atom, a substituent An optionally substituted alkyl group having 1 to 18 carbon atoms, an optionally substituted alkenyl group having 2 to 18 carbon atoms, and an optionally substituted fragrance having 6 to 18 carbon atoms. Represents an aromatic hydrocarbon group, an alicyclic hydrocarbon group having 3 to 12 carbon atoms which may have a substituent, or a heterocyclic group having 3 to 18 carbon atoms which may have a substituent. , R ¹ and R ² may combine to form a ring together with the N atom.)

（式（２）において、Ａｒ¹〜Ａｒ³は、それぞれ独立に、置換基を有していてもよい炭素数６〜１８の芳香族炭化水素基を表す。） At this time, it is preferable that the said Formula (1) is represented by following formula (2) (Claim 2).

(In Formula (2), Ar < ¹ > -Ar < ³ > represents the C6-C18 aromatic hydrocarbon group which may have a substituent each independently.)

  Another subject matter of the present invention lies in an anisotropic film composition comprising the anisotropic film material of the present invention and a solvent (claim 3).

  Still another subject matter of the present invention lies in an anisotropic film characterized by containing the anisotropic film material of the present invention (claim 4).

  Still another subject matter of the present invention lies in an optical element comprising the anisotropic film of the present invention (claim 5).

According to the present invention, an anisotropic film material that does not absorb in the visible light region and exhibits good chromonic liquid crystal properties, and an anisotropic film composition, anisotropic film, and optical element using the same Can be provided.
Moreover, the anisotropic film material of the present invention can usually exhibit one or more of the advantages described below. That is, the anisotropic film material of the present invention is stable to heat, acid, and alkali. Therefore, the anisotropic film material of the present invention does not change with time during production and storage. Therefore, if the anisotropic film material of the present invention is used, a transparent anisotropic film can be formed. Furthermore, since the anisotropic film material of the present invention exhibits chromonic liquid crystallinity, a uniform anisotropic film having a large area can be formed.

  Hereinafter, the present invention will be described in detail with reference to examples and embodiments. However, the present invention is not limited to the following examples and embodiments, and can be implemented with arbitrary modifications without departing from the gist of the present invention.

[1. Anisotropic film materials]
The anisotropic film material of the present invention is a water-soluble compound represented by the following formula (1).

[1-1. Water solubility of anisotropic film materials]
In the present specification, the water-soluble compound refers to a compound that dissolves 0.1% by weight or more in distilled water under conditions of 23 ° C. and 1 atm. Whether or not it is a water-soluble compound can be confirmed by experimentally measuring the solubility, but usually the compound represented by the formula (1) is, for example, a sulfo group, a carboxy group, a phosphate group, In the case of having a hydrophilic group such as a hydroxyl group or an ether group, the above water-soluble property is often exhibited.

（式（１）において、Ｘ¹、Ｙ¹およびＺ¹は、それぞれ独立に、ＮＲ¹Ｒ²、ＳＲ³またはＯＲ⁴を表し、Ｒ¹〜Ｒ⁴は、それぞれ独立に、水素原子、置換基を有していてもよい炭素数１〜１８のアルキル基、置換基を有していてもよい炭素数２〜１８のアルケニル基、置換基を有していてもよい炭素数６〜１８の芳香族炭化水素基、置換基を有していてもよい炭素数３〜１２の脂環炭化水素基、または、置換基を有していてもよい炭素数３〜１８の複素環基を表す。また、Ｒ¹およびＲ²は結合してＮ原子とともに環を形成していてもよい。） [1-2. Structure of anisotropic film material]

In (Equation ^{(1), X 1, Y} 1 and Z ¹ each independently represents an NR ¹ R ^2, SR ³ or OR ^4, R ¹ ~R ⁴ are each independently a hydrogen atom, a substituent An optionally substituted alkyl group having 1 to 18 carbon atoms, an optionally substituted alkenyl group having 2 to 18 carbon atoms, and an optionally substituted fragrance having 6 to 18 carbon atoms. Represents an aromatic hydrocarbon group, an alicyclic hydrocarbon group having 3 to 12 carbon atoms which may have a substituent, or a heterocyclic group having 3 to 18 carbon atoms which may have a substituent. , R ¹ and R ² may combine to form a ring together with the N atom.)

  As in the above formula (1), the anisotropic film material of the present invention is a compound having a triazine ring. The anisotropic film material of the present invention may have two or more triazine rings in one molecule, but preferably has only one triazine ring. That is, the anisotropic film material of the present invention preferably has a monotriazine structure. This is because of high liquid crystallinity and ease of manufacture.

In the formula (1), X ¹ , Y ¹ and Z ¹ each independently represent NR ¹ R ² , SR ³ or OR ⁴ . Among them, X ¹ , Y ¹ and Z ¹ are preferably NR ¹ R ² independently from the viewpoint of the stability of the compound.
At this time, X ¹ , Y ¹ and Z ¹ may be the same or different.

In the formula (1), R ^{1 to} R ⁴ are each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 18 carbon atoms, or an optionally substituted carbon number. An alkenyl group having 2 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent, an alicyclic hydrocarbon group having 3 to 12 carbon atoms which may have a substituent, or Represents a C3-C18 heterocyclic group which may have a substituent.
Hereinafter, groups constituting these R ^{1 to} R ⁴ will be described in detail.

When R ^{1 to} R ⁴ are an optionally substituted alkyl group having 1 to 18 carbon atoms, the lower limit of the carbon number of the alkyl group is 1 or more, and the upper limit is 18 or less. However, among these, 9 or less is preferable.

  Specific examples of the alkyl group having 1 to 18 carbon atoms include an optionally substituted methyl group such as a methyl group; an ethyl group, a 2-hydroxyethyl group, a 2-sulfoethyl group, a 2-carboxyethyl group, An optionally substituted ethyl group such as 2-cyanoethyl group; an optionally substituted propyl group such as n-propyl group, i-propyl group, 2,3-dihydroxypropyl group, 3-carboxypropyl group; n -An optionally substituted butyl group such as a butyl group; an optionally substituted hexyl group such as an n-hexyl group and a 2-ethylhexyl group; an optionally substituted octyl group such as an n-octyl group; n -Nonyl group which may be substituted, such as nonyl group; Dodecyl group which may be substituted, such as n-dodecyl group, etc. are mentioned.

  Among the specific examples of the alkyl group having 1 to 18 carbon atoms, preferred are methyl group, ethyl group, 2-hydroxyethyl group, 2-sulfoethyl group, 2-cyanoethyl group, n-propyl group, 2 , 3-dihydroxypropyl group, 3-carboxypropyl group, n-butyl group, n-hexyl group, n-octyl group and n-nonyl group.

  As a substituent which the said C1-C18 alkyl group may have, as long as the effect of this invention is not impaired remarkably, it is arbitrary, For example, a C1-C4 alkyl group, C1-C1 -4 alkoxy groups, hydroxyl groups, cyano groups, optionally substituted amino groups, optionally substituted carbamoyl groups, optionally substituted sulfamoyl groups, sulfo groups, carboxy groups and the like.

  Examples of the substituent of the amino group which may be substituted include, for example, an acyl group having 2 to 7 carbon atoms such as acetyl group and benzoyl group; methyl group, ethyl group, 2-hydroxyethyl group, butyl C1-C4 alkyl groups, such as group, etc. are mentioned. Moreover, as a substituent which the said carbamoyl group which may be substituted has, C1-C4 alkyl groups, such as a methyl group, an ethyl group, 2-hydroxyethyl group, a butyl group, etc. are mentioned. Furthermore, as a substituent which the said sulfamoyl group which may be substituted has, C1-C4 alkyl groups, such as a methyl group, an ethyl group, 2-hydroxyethyl group, a butyl group, etc. are mentioned.

  Moreover, the substituent mentioned above may comprise the single substituent which two or more substituents couple | bonded together by arbitrary combinations and ratios. Furthermore, the C1-C18 alkyl group may have only one substituent and may have two or more in arbitrary combinations and ratios.

When R ^{1 to} R ⁴ are an optionally substituted alkenyl group having 2 to 18 carbon atoms, the lower limit of the carbon number of the alkenyl group is 2 or more, and the upper limit is 18 or less. However, among these, 9 or less is preferable.

  Specific examples of the alkenyl group having 2 to 18 carbon atoms include a vinyl group, an allyl group, and a 2-methyl-1-propenyl group.

  Among the specific examples of the alkenyl group having 2 to 18 carbon atoms, preferred are a vinyl group and an allyl group.

The substituent that the alkenyl group having 2 to 18 carbon atoms may have is arbitrary as long as the effects of the present invention are not significantly impaired, and examples thereof include an alkyl group having 1 to 4 carbon atoms. .
In addition, the said substituent may comprise two or more substituents couple | bonded by arbitrary combinations and ratios, and may comprise the single substituent. Furthermore, the C2-C18 alkenyl group may have only one substituent and may have two or more in any combination and ratio.

When R ^{1 to} R ⁴ are an optionally substituted aromatic hydrocarbon group having 6 to 18 carbon atoms, the lower limit of the number of carbon atoms of the aromatic hydrocarbon group is 6 or more, The upper limit is 18 or less, with 14 or less being preferred.

  Specific examples of the aromatic hydrocarbon group having 6 to 18 carbon atoms include phenyl group, 3-cyanophenyl group, 4-cyanophenyl group, 3-carbamoylphenyl group, 4-carbamoylphenyl group, 4-sulfo group. Even if phenyl group, 4-carboxyphenyl group, 3-fluorophenyl group, 4-fluorophenyl group, 3-acetylaminophenyl group, 4-acetylaminophenyl group, 2,5-dicarbamoylphenyl group, etc. are substituted Good phenyl group; 1-naphthyl group, 2-naphthyl group, 5-sulfo-2-naphthyl group, 6-sulfo-2-naphthyl group, 7-sulfo-2-naphthyl group, 6,8-disulfo-2-naphthyl And a naphthyl group which may be substituted such as a group.

  Among the specific examples of the aromatic hydrocarbon group having 6 to 18 carbon atoms, preferred are 3-cyanophenyl group, 3-carbamoylphenyl group, 4-sulfophenyl group, 4-carboxyphenyl group, 6 -Sulfo-2-naphthyl group, 6,8-disulfo-2-naphthyl group.

  The substituent that the aromatic hydrocarbon group having 6 to 18 carbon atoms may have is optional as long as the effect of the present invention is not significantly impaired, for example, an alkyl group having 1 to 4 carbon atoms, An alkoxy group having 1 to 4 carbon atoms, a hydroxyl group, a cyano group, a nitro group, a halogen atom, an optionally substituted amino group, an optionally substituted carbamoyl group, an optionally substituted sulfamoyl group, a sulfo group, A carboxy group, a phosphate group, etc. are mentioned.

  In addition, examples of the substituent that the amino group that may be substituted include, the substituent that the carbamoyl group that may be substituted include, and the substituent that the sulfamoyl group that may be substituted include include. These are the same as those described above as the substituents that the alkyl group substituents having 1 to 18 carbon atoms may further have.

  Moreover, the substituent mentioned above may comprise the single substituent which two or more substituents couple | bonded together by arbitrary combinations and ratios. Furthermore, the C6-C18 aromatic hydrocarbon group may have only one substituent and may have two or more in any combination and ratio.

When R ^{1 to} R ⁴ are an alicyclic hydrocarbon group having 3 to 12 carbon atoms that may have a substituent, the lower limit of the carbon number of the alicyclic hydrocarbon group is 3 or more, 6 or more is preferable, and the upper limit is 12 or less.

  Specific examples of the alicyclic hydrocarbon group having 3 to 12 carbon atoms include a cyclohexyl group and a 4-carboxycyclohexyl group.

  Among the specific examples of the alicyclic hydrocarbon group having 3 to 12 carbon atoms, a 4-carboxycyclohexyl group is preferable.

  The substituent that the alicyclic hydrocarbon group having 3 to 12 carbon atoms may have is optional as long as the effect of the present invention is not significantly impaired, for example, an alkyl group having 1 to 4 carbon atoms, A C1-C4 alkoxy group, a carboxy group, etc. are mentioned.

  Moreover, the substituent mentioned above may comprise the single substituent which two or more substituents couple | bonded together by arbitrary combinations and ratios. Furthermore, the C3-C12 alicyclic hydrocarbon group may have only one substituent, and may have two or more in any combination and ratio.

When R ^{1 to} R ⁴ are an optionally substituted heterocyclic group having 3 to 18 carbon atoms, the lower limit of the number of carbon atoms in the heterocyclic group is 3 or more, and among these, 5 or more is preferable. In addition, the upper limit is 18 or less, with 14 or less being preferred.

  Specific examples of the heterocyclic group having 3 to 18 carbon atoms include pyridyl group, pyrimidyl group, quinolyl group, benzothiazolyl group, benzimidazolyl group, 1,3-dioxo-2,3-dihydro-1H-isoindole Examples include a -5-yl group and a 2-oxo-2,3-dihydro-1H-benzimidazole-5 group.

  Of the specific examples of the heterocyclic group having 3 to 18 carbon atoms, preferred are a pyridyl group, a benzothiazolyl group, a 1,3-dioxo-2,3-dihydro-1H-isoindol-5-yl group. 2-oxo-2,3-dihydro-1H-benzimidazole-5-group.

  The substituent that the heterocyclic group having 3 to 18 carbon atoms may have is optional as long as the effects of the present invention are not significantly impaired. For example, the alkyl group having 1 to 4 carbon atoms and the carbon number 1-4 alkoxy group, hydroxyl group, cyano group, nitro group, halogen atom, optionally substituted amino group, optionally substituted carbamoyl group, optionally substituted sulfamoyl group, sulfo group, carboxy group Etc.

  In addition, examples of the substituent that the amino group that may be substituted include, the substituent that the carbamoyl group that may be substituted include, and the substituent that the sulfamoyl group that may be substituted include include. These are the same as those described above as the substituents that the alkyl group substituents having 1 to 18 carbon atoms may further have.

  Moreover, the substituent mentioned above may comprise the single substituent which two or more substituents couple | bonded together by arbitrary combinations and ratios. Furthermore, the C3-C18 heterocyclic group may have only one substituent, and may have two or more in an arbitrary combination and ratio.

In the above formula (1), R ¹ and R ² may be bonded to form a ring together with the N atom. In this case, the structure of the ring formed is arbitrary as long as the effects of the present invention are not significantly impaired, and examples thereof include a piperidine ring, a piperazine ring, and a morpholine ring.

Among those described above, R ^{1 to} R ⁴ are preferably an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent.

Among the above-mentioned NR ¹ R ² , SR ³ and OR ⁴ , examples of suitable ones include 4-sulfophenylamino group, 4-carboxyphenylamino group, 6-sulfo-2-naphthyl group, 6,8. -Disulfo-2-naphthylamino group, 3-cyanophenylamino group, 3-carbamoylphenylamino group, phenoxy group, phenylthio group, 4-pyridylamino group, 2-oxo-2,3-dihydro-1H-benzimidazole-5 -An amino group etc. are mentioned.

（式（２）において、Ａｒ¹〜Ａｒ³は、それぞれ独立に、置換基を有していてもよい炭素数６〜１８の芳香族炭化水素基を表す。） Furthermore, among the compounds represented by the formula (1), as the anisotropic film material of the present invention, a compound represented by the following formula (2) is particularly preferable.

(In Formula (2), Ar < ¹ > -Ar < ³ > represents the C6-C18 aromatic hydrocarbon group which may have a substituent each independently.)

In the formula (2), the aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent and constitutes Ar ^{1 to} Ar ³ is R ^{1 to} R ⁴ in the formula (1). The same as the aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent described above. Therefore, the aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent and constitutes Ar ^{1 to} Ar ³ may have specific examples, preferred specific examples, preferred carbon numbers and the like. Good substituents are the same as in the case where each of R ^{1 to} R ⁴ is an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent.

  Moreover, when the anisotropic membrane material of the present invention has an acid group, it may be used in the form of a free acid (free acid type), and a part of the acid group takes a salt form. It may be a thing. Moreover, the salt type compound and the free acid type compound may be mixed in any combination and ratio. Furthermore, when it is obtained in a salt form at the time of production, it may be used as it is or may be converted into a desired salt form. As a salt type exchange method, a known method can be arbitrarily used, and examples thereof include the following methods 1) to 4).

1) A strong acid (such as hydrochloric acid) is mixed with the aqueous solution of the anisotropic membrane material obtained in the salt form, and the anisotropic membrane material is acidified in the form of a free acid. A method of neutralizing a dye acidic group with an alkaline solution (for example, an aqueous lithium hydroxide solution) and performing salt exchange.
2) A large excess of neutral salt (eg, lithium chloride) having the desired counter ion is mixed with the aqueous solution of the anisotropic membrane material obtained in the salt form, and salt exchange is performed in the form of a salting out cake. How to do.
3) The aqueous solution of the anisotropic membrane material obtained in the salt form is treated with a strongly acidic cation exchange resin, and the anisotropic membrane material is acidified in the form of a free acid. A method of neutralizing the acidic groups of the anisotropic membrane material and performing salt exchange with an alkaline solution (for example, an aqueous lithium hydroxide solution) containing
4) Salt exchange is performed by causing an aqueous solution of anisotropic membrane material obtained in salt form to act on a strongly acidic cation exchange resin that has been previously treated with an alkaline solution having a desired counter ion (for example, an aqueous lithium hydroxide solution). How to do.

Whether the acidic group of the anisotropic film material of the present invention takes a free acid type or a salt type is usually determined by the pKa of the anisotropic film material and the aqueous solution of the anisotropic film material. Depends on pH.
Examples of the above salt types include salts of alkali metals such as Na, Li, and K; salts of ammonium optionally substituted with an alkyl group or hydroxyalkyl group; salts of organic amines, and the like. Examples of these organic amines include lower alkyl amines having 1 to 6 carbon atoms, hydroxy-substituted lower alkyl amines having 1 to 6 carbon atoms, and carboxy-substituted lower alkyl amines having 1 to 6 carbon atoms. The number of substituents possessed by the organic amine may be one or two or more. In addition, in the case of these salt types, the type is not limited to one type, and a plurality of types may be mixed in any combination and ratio.

  Among the examples of the anisotropic film material of the present invention, suitable ones are shown below. In addition, although all the following examples are represented in the form of a free acid, these may be a salt form.

  The molecular weight of the anisotropic film material of the present invention is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 126 or more, preferably 200 or more, and usually 2000 or less, preferably 1000 or less. . If the molecular weight is too large, the solubility may decrease.

[1-3. Properties of anisotropic film materials]
The material for an anisotropic film of the present invention usually has no absorption in the visible light region. Specifically, when the anisotropic membrane material of the present invention is dissolved in distilled water at a concentration of 10 ppm and the molar extinction coefficient ε is measured using the solution, it absorbs light in a wavelength region of 400 nm to 700 nm. There is no waste. Here, in the above case, when the molar extinction coefficient ε is 500 or less, it is regarded as having no absorption.

  The anisotropic film material of the present invention exhibits chromonic liquid crystallinity. For this reason, if the anisotropic film material of the present invention is used, a uniform anisotropic film having a large area can be formed. Here, the presence or absence of chromonic liquid crystallinity can be confirmed by observation with a polarizing microscope (for example, Eclipse E600-POL manufactured by Nikon). Specifically, an anisotropic film composition to be described later is dropped on a slide glass, covered with a cover glass, and then observed in a crossed Nicol state using a polarizing microscope. Schlieren-like as described in J. Lydon, "Chapter XVIII. Chromonics", in "Handbook of Liquid Crystals", vol.2B: Low Molecular Weight Liquid Crystals II, p981, Wiley-VCH, (1998). If the texture can be observed, it can be seen that it has liquid crystallinity.

  The reason why the anisotropic film material of the present invention does not absorb in the visible light region and exhibits chromonic liquid crystal properties as previously described is not clear, but the present invention is not clear. According to the above, it is presumed to be due to the planarity of the molecule.

Further, the material for an anisotropic film of the present invention is not limited in its physical properties, but usually has one or more excellent physical properties described below.
That is, the anisotropic film material of the present invention is usually stable to heat. Although there is no restriction | limiting in the specific degree of stability with respect to heat, Even if it becomes temperature of 100 degreeC or more normally, Preferably it is 200 degreeC or more, More preferably, it is 250 degreeC or more, the material for anisotropic membranes of this invention reacts. Or do not disassemble. In addition, although there is no restriction | limiting in an upper limit, Usually, it is 300 degrees C or less.

  The anisotropic film material of the present invention is usually stable to acids. Although there is no restriction | limiting in the specific degree of stability with respect to an acid, Even if it becomes pH 6 or less normally, Preferably it is 4 or less, More preferably, it is 2 or less, the material for anisotropic membranes of this invention does not react or decompose. do not do. In addition, although there is no restriction | limiting in the minimum of the said pH, Usually, it is 0 or more.

  The anisotropic film material of the present invention is usually stable against alkali. Although there is no restriction | limiting in the specific degree of stability with respect to an alkali, Even if it becomes pH of 8 or more normally, Preferably it is 10 or more, More preferably, it is 12 or more, the material for anisotropic membranes of this invention does not react or decompose. do not do. In addition, although there is no restriction | limiting in the upper limit of the said pH, Usually, it is 14 or less.

  Further, as described above, the anisotropic film material of the present invention is usually stable against heat, acid and alkali, so there is no change over time during production and storage, and there is a possibility of exhibiting coloring or the like. Low. Therefore, if the anisotropic film material of the present invention is used, a transparent anisotropic film can be formed.

[1-4. Method for manufacturing anisotropic film material]
There is no restriction | limiting in the manufacturing method of the material for anisotropic films | membranes of this invention, For example, it can manufacture according to a well-known conventional method. If a specific example is given, the compound represented by the said exemplary compound (1-1) can be manufactured through the process of following (A)-(D).
(A) 4-Aminobenzenesulfonic acid (sulfanilic acid) is dissolved in water at pH 6 and cooled to 0-5 ° C. Cyanuric chloride is mixed with this, and the reaction is performed for 2 hours while maintaining the temperature at 0 to 5 ° C. to complete the reaction.
(B) Next, a 4-aminobenzenesulfonic acid (sulfanilic acid) aqueous solution is mixed at room temperature, and a condensation reaction is performed at pH 5 to 6 for several hours to complete the reaction.
(C) This is mixed with 3-aminobenzamide and subjected to a condensation reaction at a temperature of 60 to 70 ° C. and a pH of 7 to 9 for several hours to complete the reaction.
(D) The salt of the objective exemplary compound (1-1) is obtained by salting out with sodium chloride after cooling.

[2. Anisotropic film composition]
The composition for anisotropic films of the present invention contains at least the material for anisotropic films of the present invention and a solvent. Moreover, the composition for anisotropic films of this invention may contain the other component.

[2-1. Anisotropic film materials]
The anisotropic film composition of the present invention contains the above-described anisotropic film material of the present invention. Under the present circumstances, only 1 type may contain the material for anisotropic films of this invention, and 2 or more types may contain it by arbitrary combinations and a ratio.

  In addition, the anisotropic film composition of the present invention can contain other anisotropic film materials in combination with the anisotropic film material of the present invention as an anisotropic film material. It is. For example, chromonic liquid crystal compounds described in Non-Patent Document 5, "R. Hentschke, PJB Edwards, N. Boden, RJ Bushby, Macromol. Symp., 81, 361-367, (1994)", etc. Is mentioned. Specific examples of suitable ones include disodium cromoglycate (DSCG), 7,7-chromoglycate, baflorin sodium salt, nafoxidine, acrinol, hexa-oxaalkyl-triphenylene and the like. As described above, the optical anisotropy is precisely controlled by including the other anisotropic film material in the anisotropic film composition of the present invention in combination with the anisotropic film material of the present invention. It is possible to manufacture the anisotropic film. In addition, only 1 type may be used for another anisotropic film material, and 2 or more types may be used together by arbitrary combinations and a ratio.

  The amount of the other anisotropic film material can be arbitrarily set depending on the desired degree of optical anisotropy, but is a ratio to the total amount of the anisotropic film material in the anisotropic film composition of the present invention. Usually, it is preferably 50% by weight or less, more preferably 30% by weight or less, and particularly preferably 10% by weight or less. If there are too many other anisotropic film materials, phase separation may occur in the composition for anisotropic film, or phase separation may occur during coating and drying, which may cause defects in the anisotropic film. This is because the effects of the present invention may not be exhibited effectively.

  The concentration of the anisotropic film material in the composition for the anisotropic film of the present invention depends on the solubility of the anisotropic film material and the formation concentration of the supramolecular structure such as the chromonic liquid crystal state. It is preferably 0.1% by weight or more, particularly 0.5% by weight or more, and is usually 50% by weight or less, preferably 30% by weight or less. If the concentration of the material for the anisotropic film is too small, a uniform anisotropic film may not be formed. If the concentration is too high, the viscosity of the composition for the anisotropic film may increase and it may be difficult to handle.

[2-2. solvent]
The composition for anisotropic films of the present invention contains a solvent. This solvent may be selected in consideration of the operability of the anisotropic film composition in the wet film formation method, the chromonic liquid crystal state of the anisotropic film material, and the like.

  As examples of the solvent, water, a water-miscible organic solvent, or a mixture thereof is suitable. Specific examples of the organic solvent include lower alcohols having 1 to 4 carbon atoms such as methyl alcohol, ethyl alcohol and isopropyl alcohol; glycols such as ethylene glycol and diethylene glycol; cellosolves such as methyl cellosolve and ethyl cellosolve. Etc. In addition, only 1 type may be used for a solvent and it may use 2 or more types together by arbitrary combinations and a ratio.

[2-3. Other ingredients]
The anisotropic film composition of the present invention may contain other components in addition to the above-mentioned anisotropic film material and solvent. Moreover, these other components may use only 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

Examples of other components include additives such as surfactants. In the formation of an anisotropic film, a surfactant is used as necessary to improve the wettability and coatability to the substrate surface when the composition for anisotropic film of the present invention is applied to the substrate. It is used. As the surfactant, any of an anionic surfactant, a cationic surfactant, and a nonionic surfactant can be used. Moreover, surfactant may use only 1 type and may use 2 or more types together by arbitrary combinations and a ratio.
The concentration of the surfactant in the composition for an anisotropic film of the present invention is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually in the range of 0.05 wt% or more and 0.5 wt% or less. Is preferred.

[2-4. Use of anisotropic film composition]
The composition for an anisotropic film of the present invention can exhibit a higher-order molecular orientation state through a process unique to a wet film-forming method, that is, a lamination process such as coating on a substrate surface. Therefore, if the anisotropic film composition containing the anisotropic film material of the present invention is used, a large-area anisotropic film can be formed by a wet film forming method.

[3. Anisotropic film]
An anisotropic film is a film having anisotropy in electromagnetic properties in any two directions selected from a total of three directions in the three-dimensional coordinate system of the thickness direction of the film and any two orthogonal in-plane directions. Examples of the electromagnetic property include optical properties such as absorption and refraction, and electrical properties such as resistance and capacitance. Examples of the film having optical anisotropy such as absorption and refraction include a linearly polarizing film, a circularly polarizing film, a retardation film, and a conductive anisotropic film. In the present invention, among the anisotropic films, a retardation film is preferable.

[3-1. Structure of anisotropic film]
The anisotropic film of the present invention is formed by containing the above-described anisotropic film material of the present invention. Under the present circumstances, the anisotropic film of this invention may contain only 1 type of the material for anisotropic films of this invention, and may contain 2 or more types by arbitrary combinations and ratios.

  Further, the anisotropic film of the present invention may be formed only from the material for the anisotropic film, but may also be formed containing other components. Other components contained in the anisotropic film of the present invention are optional as long as the effects of the present invention are not significantly impaired, but in the anisotropic film composition of the present invention, in addition to the anisotropic film material and the solvent. The thing similar to the other component which may be contained is mentioned. Moreover, only 1 type may contain other components and 2 or more types may contain it by arbitrary combinations and a ratio.

  The thickness of the anisotropic film of the present invention is arbitrary as long as the effects of the present invention are not significantly impaired, but the film thickness after drying is usually preferably 50 nm or more, and usually 30 μm or less, especially 20 μm or less, especially 10 μm or less is preferable. If the film thickness is below the lower limit, it may be difficult to obtain a uniform film thickness in the anisotropic film. On the other hand, if the film thickness exceeds the upper limit, uniform alignment of molecules in the anisotropic film may occur. It may be difficult to obtain.

[3-2. Method for manufacturing anisotropic film]
There is no restriction | limiting in the manufacturing method of the anisotropic film | membrane of this invention. However, it is usually preferable to produce using the anisotropic film composition of the present invention including the anisotropic film material of the present invention. As described above, the anisotropic film material of the present invention has no absorption in the visible light region, and is usually stable to heat, acid, and alkali, and therefore contains the anisotropic film material. If the composition for anisotropic membranes to be used is used, a transparent anisotropic membrane can be provided without change over time during production and storage. In addition, since the anisotropic film material of the present invention has a specific structure and exhibits high chromonic liquid crystal properties, it is possible to provide a large area and uniform anisotropic film.

  When an anisotropic film is produced using the anisotropic film material of the present invention, a wet film forming method is used. In the wet film-forming method, a process including a film-forming process for applying the anisotropic film composition to a substrate and a drying process for removing the solvent is performed. The orientation of the anisotropic film material may be performed either in the coating process or in the drying process. Specifically, after preparing the anisotropic film composition, the anisotropic film composition is applied to various substrates such as glass plates, then the anisotropic film material is applied, and the solvent is removed. A known method such as a method of forming by drying and removing may be used.

Hereinafter, this method will be described in more detail.
First, the composition for anisotropic films of this invention and the base material for forming an anisotropic film are prepared. Although there is no restriction | limiting in a base material, For example, the base material demonstrated by the term of the optical element mentioned later can be used. The base material may be previously subjected to an alignment treatment.

  And the composition for anisotropic films | membranes of this invention is apply | coated to a base material with a wet film-forming method (application | coating process). Here, the wet film forming method is a method of forming a film for an anisotropic film composition by a known coating method or the like. Specific examples include "Yuji Harasaki," Coating Engineering ", Asakura Shoten Co., Ltd., published on March 20, 1971, pages 253 to 277," "Creation and Application of Molecularly Cooperative Materials" supervised by Kunihiro Ichimura. Company CMC Publishing, published on March 3, 1998, pages 118 to 149, etc., and “Harazaki Yuji's“ Coating Method ”Tsuji Shoten, published October 30, 1979, Each coater method described in page 3 (Table 1-2) and pages 6 to 154), spin coat method, spray coat method, bar coat method, roll coat method, blade coat method, free span coat Applying a composition for anisotropic film by a method, a die coating method or the like.

The operating conditions for performing the coating are arbitrary as long as the anisotropic film of the present invention is obtained. However, it is preferable to control the operating conditions so as to maintain a higher-order molecular alignment state formed based on high chromonic liquid crystallinity due to self-organization of the anisotropic film material.
Specifically, the temperature at the time of application | coating on the base material of the composition for anisotropic films | membranes in an application | coating process is preferable normally 0 degreeC or more, and usually 80 degrees C or less, Especially 40 degrees C or less is preferable. Moreover, the humidity at the time of application | coating on the base material of the composition for anisotropic films | membranes in an application | coating process is 10% RH or more normally, Especially 30% RH or more is preferable and 80% RH or less is preferable normally.

After the coating step, the solvent is dried and removed from the coating film of the composition for anisotropic film coated on the substrate. At this time, the anisotropic film material is aligned with the removal of the solvent, and exhibits chromonic liquid crystallinity.
The operating conditions for drying are arbitrary as long as the anisotropic film of the present invention is obtained. However, as in the coating process, the above operating conditions can be controlled so as to maintain a higher-order molecular alignment state formed on the basis of high chromonic liquid crystallinity due to the self-organization of the anisotropic film material. preferable. Further, when the temperature is raised during drying, it is more preferable to avoid a rapid temperature rise.

Specifically, the temperature during drying in the drying step is usually 0 ° C. or higher, preferably 10 ° C. or higher, and usually 120 ° C. or lower, particularly preferably 110 ° C. or lower. Moreover, the humidity during drying in the drying step is usually 10% RH or more, preferably 30% RH or more, and usually 80% RH or less.
If it carries out as mentioned above, the anisotropic film | membrane of this invention can be obtained on a base material.

[4. Optical element]
The optical element of the present invention is an optical element provided with the above-described anisotropic film of the present invention. The optical element of the present invention may be an optical element composed only of the anisotropic film of the present invention, or may include a member other than the anisotropic film. Usually, the anisotropic film of the present invention includes a base material and has an anisotropic film on the base material. In this case, the substrate including the base material is called an optical element.

  As a base material, arbitrary things can be used according to the use of an optical element. Examples thereof include glass, triacetate, acrylic, polyester, triacetyl cellulose, and urethane film. In addition, in order to control the orientation direction of the dichroic dye on the surface of the base material, “Liquid Crystal Handbook” published by Maruzen Co., Ltd., October 30, 2000, pages 226 to 239, etc. An alignment treatment for forming an alignment treatment layer may be performed by a known method.

  In addition, the optical element of the present invention may include one or more members other than the anisotropic film and the base material. When the example is given, a protective layer will be mentioned. This protective layer is a layer provided as necessary when the mechanical strength of the anisotropic film is low. Although there is no restriction | limiting in the specific structure, For example, transparent polymer films, such as a triacetate, an acryl, polyester, a polyimide, a triacetyl cellulose, or a urethane type film, are laminated | stacked and formed.

  Furthermore, the optical element of the present invention is an adhesive layer, or an antireflection layer, an alignment film, a layer having a function as a retardation film, a layer having a function as a brightness enhancement film, a layer having a function as a reflection film, You may provide the layer which has various functions, such as a layer which has a function as a transflective film, a layer which has a function as a diffusion film, and a layer which has each optical function. In this case, the layers and films can be stacked by, for example, a wet film forming method. Moreover, you may laminate | stack the said layer and film | membrane in what order according to a use. When laminated in this way, the optical element of the present invention is configured as a laminate.

The layer having the optical function can be formed by the following method, for example.
The layer having a function as a retardation film is subjected to, for example, a stretching process described in Japanese Patent No. 2841377, Japanese Patent No. 3094113, or a process described in Japanese Patent No. 3168850. Can be formed.

  The layer having a function as a brightness enhancement film is formed by forming a fine hole by a method as described in JP-A No. 2002-169025, JP-A No. 2003-29030, or the like, or the center of selective reflection, for example. It can be formed by overlapping two or more cholesteric liquid crystal layers having different wavelengths.

  The layer having a function as a reflective film or a transflective film can be formed using a metal thin film obtained by vapor deposition or sputtering.

  The layer having a function as a diffusion film can be formed by coating the protective layer with a resin solution containing fine particles.

  Further, the layer having the function as the retardation film and the layer having the function as the optical compensation film are obtained by applying and aligning a liquid crystal compound such as a discotic liquid crystal compound or a nematic liquid crystal compound. Can be formed.

  EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples, and can be arbitrarily modified and implemented without departing from the gist of the present invention. . In the following description of Examples, “part” means “part by weight” unless otherwise specified.

[Evaluation methods]
In the following Examples and Comparative Examples, various evaluations of the anisotropic film material and the formed anisotropic film were performed as follows.

(1) Absorption spectrum The anisotropic membrane material was dissolved in distilled water at a concentration of 10 ppm, and the molar extinction coefficient ε was measured in the range of 250 nm to 850 nm using a spectrophotometer U-3500 manufactured by Hitachi, Ltd. It was investigated whether it has absorption in a visible light region of 700 nm to 700 nm.

(2) Retardation Retardation Re of the anisotropic dye film with respect to incident light of 550 nm was measured using RETS-100 manufactured by Otsuka Electronics.

(3) Positive and negative birefringence Interference color change by inserting a test plate under crossed Nicols of a polarizing microscope according to the method described in "Hiroshi Hiroya" Introduction to Polarizing Microscope of Polymer Materials "(2001), Agne Technical Center" From the above, the positive / negative of birefringence was determined.

(4) Liquid crystallinity The composition for anisotropic film was dropped on a slide glass, covered with a cover glass, and then observed in a crossed Nicol state at normal temperature using a polarizing microscope (Eclipse E600-POL manufactured by Nikon). At this time, as described in J. Lydon, "Chapter XVIII. Chromonics", in "Handbook of Liquid Crystals", vol. 2B: Low Molecular Weight Liquid Crystals II, p981, Wiley-VCH, (1998). If a schlieren-like texture can be observed, it turns out that it has liquid crystallinity.

[Example 1]
The absorption spectrum of a 10 ppm aqueous solution of the lithium salt of the exemplified compound (1-1) subjected to desalting and purification was measured. The results are shown in FIG. As shown in FIG. 1, the visible light region did not absorb.

In 69 parts of water, 31 parts of the lithium salt of the exemplified compound (1-1) obtained by desalting and purification was stirred and dissolved, followed by filtration to obtain a composition for optically anisotropic film having pH = 9. When this composition for optically anisotropic films was observed with a polarizing microscope, it was confirmed to have liquid crystallinity.
On the glass substrate (75 mm × 25 mm, thickness 1 mm), the anisotropic film composition is applied with an applicator having a gap of 2 μm (four-side applicator manufactured by Imoto Seisakusho Co., Ltd.), and then naturally dried to be transparent. An anisotropic film was obtained. The obtained anisotropic film was evaluated for positive and negative birefringence and retardation. As a result, the anisotropic film had negative birefringence and the retardation was 257 nm. From this result, it can be seen that the anisotropic film of this example can be sufficiently used as a retardation film.

[Example 2]
The absorption spectrum of a 10 ppm aqueous solution of the lithium salt of the exemplified compound (1-10) subjected to desalting and purification was measured. The results are shown in FIG. As shown in FIG. 2, the visible light region did not absorb.

In 65 parts of water, 10 parts of the lithium salt of the exemplified compound (1-10) subjected to desalting and purification and 25 parts of the lithium salt of the exemplified compound (1-1) subjected to desalting and purification were stirred and dissolved, and then filtered to obtain pH = Thus, a composition for optically anisotropic film 8 was obtained. When this composition for optically anisotropic films was observed with a polarizing microscope, it was confirmed to have liquid crystallinity.
On the same glass substrate as in Example 1, the anisotropic film composition was applied with an applicator having a gap of 5 μm (four-side applicator manufactured by Imoto Seisakusho Co., Ltd.), and then naturally dried to obtain transparent anisotropy. A membrane was obtained. When the obtained anisotropic film was evaluated for positive and negative birefringence and retardation, it had negative birefringence and the retardation was 319 nm. From this result, it can be seen that the anisotropic film of this example can be sufficiently used as a retardation film.

[Example 3]
The absorption spectrum of a 10 ppm aqueous solution of the lithium salt of the exemplified compound (1-2) subjected to desalting and purification was measured. The results are shown in FIG. As shown in FIG. 3, the visible light region did not absorb.

In 76 parts of water, 24 parts of the desalted and purified lithium salt of the exemplary compound (1-2) was stirred and dissolved, followed by filtration to obtain a composition for an optically anisotropic film having a pH = 9. When this composition for optically anisotropic films was observed with a polarizing microscope, it was confirmed to have liquid crystallinity.
On the same glass substrate as in Example 1, the anisotropic film composition was applied with an applicator having a gap of 5 μm (four-side applicator manufactured by Imoto Seisakusho Co., Ltd.), and then naturally dried to obtain transparent anisotropy. A membrane was obtained. The obtained anisotropic film was evaluated for positive and negative birefringence and phase difference. As a result, the anisotropic film had negative birefringence and the phase difference was 132 nm. From this result, it can be seen that the anisotropic film of this example can be sufficiently used as a retardation film.

[Example 4]
The absorption spectrum of a 10 ppm aqueous solution of the lithium salt of the exemplified compound (1-3) subjected to desalting and purification was measured. The results are shown in FIG. As shown in FIG. 4, the visible light region did not absorb.

In 72 parts of water, 28 parts of the desalted and purified lithium salt of Exemplified Compound (1-3) was stirred and dissolved, followed by filtration to obtain a composition for optically anisotropic film having pH = 9. When this composition for optically anisotropic films was observed with a polarizing microscope, it was confirmed to have liquid crystallinity.
On the same glass substrate as in Example 1, the anisotropic film composition was applied with an applicator having a gap of 5 μm (four-side applicator manufactured by Imoto Seisakusho Co., Ltd.), and then naturally dried to obtain transparent anisotropy. A membrane was obtained. Evaluation of the birefringence positive / negative and phase difference of the obtained anisotropic film showed negative birefringence, and the phase difference was 221 nm. From this result, it can be seen that the anisotropic film of this example can be sufficiently used as a retardation film.

[Comparative Example 1]
The absorption spectrum of a 10 ppm aqueous solution of an ammonium salt of the following compound (2-1) was measured. The results are shown in FIG. As shown in FIG. 5, the bottom of absorption was in the visible light region.

In 82.4 parts of water, 9.6 parts of 2M aqueous ammonia and 8 parts of the desalted and purified compound (2-1) are stirred and dissolved, followed by filtration to obtain a composition for an optically anisotropic film having pH = 8. It was. When this composition for optically anisotropic films was observed with a polarizing microscope, it was confirmed to have liquid crystallinity.
On the glass substrate similar to Example 1, the above anisotropic film composition was applied with an applicator having a gap of 20 μm (four-side applicator manufactured by Imoto Seisakusho Co., Ltd.), and then anisotropically colored yellow by natural drying. A sex membrane was obtained. The obtained anisotropic film was evaluated for positive and negative birefringence and phase difference. As a result, the film had negative birefringence and the phase difference was 73 nm, but it could not be used as a phase difference film due to coloring. It was.

[Comparative Example 2]
10 parts of the following compound (2-2) was stirred and dissolved in 90 parts of water, followed by filtration to obtain a composition for an optically anisotropic film having a pH of 8. When this composition for optically anisotropic films was observed with a polarizing microscope, it did not show liquid crystallinity.

  On the same glass substrate as in Example 1, the above anisotropic film composition was applied with an applicator having a gap of 5 μm (four-side applicator manufactured by Imoto Seisakusho Co., Ltd.), and then naturally dried to obtain a transparent film. It was. When the obtained film was evaluated for positive / negative of birefringence and retardation, the film had no anisotropy, the retardation was 0 nm, and the film did not have a function as a retardation film.

[Summary]
From the results of Examples 1 to 4 and Comparative Examples 1 and 2, it can be seen that the use of the anisotropic film material of the present invention can provide a transparent retardation film having no absorption in the visible light region.

  The present invention can be used in any field where an anisotropic film is used, but only a liquid crystal display or an organic EL display can be obtained from the viewpoint that a thin, large-area anisotropic film can be obtained at low cost. In addition, it can be suitably used for applications such as a liquid crystal projector, an in-vehicle display panel, a flexible display, and the like that can be reduced in thickness and area at low cost.

It is a figure showing the absorption spectrum measured in Example 1 of this invention. It is a figure showing the absorption spectrum measured in Example 2 of this invention. It is a figure showing the absorption spectrum measured in Example 3 of this invention. It is a figure showing the absorption spectrum measured in Example 4 of this invention. 6 is a diagram illustrating an absorption spectrum measured in Comparative Example 1. FIG.

Claims (5)

An anisotropic film material comprising a water-soluble compound represented by the following formula (1).

In (Equation ^{(1), X 1, Y} 1 and Z ¹ each independently represents an NR ¹ R ^2, SR ³ or OR ^4, R ¹ ~R ⁴ are each independently a hydrogen atom, a substituent An optionally substituted alkyl group having 1 to 18 carbon atoms, an optionally substituted alkenyl group having 2 to 18 carbon atoms, and an optionally substituted fragrance having 6 to 18 carbon atoms. Represents an aromatic hydrocarbon group, an alicyclic hydrocarbon group having 3 to 12 carbon atoms which may have a substituent, or a heterocyclic group having 3 to 18 carbon atoms which may have a substituent. , R ¹ and R ² may combine to form a ring together with the N atom.) The said formula (1) is represented by following formula (2), The material for anisotropic films of Claim 1 characterized by the above-mentioned.

(In Formula (2), Ar < ¹ > -Ar < ³ > represents the C6-C18 aromatic hydrocarbon group which may have a substituent each independently.) An anisotropic film composition comprising the anisotropic film material according to claim 1 and a solvent. An anisotropic film comprising the anisotropic film material according to claim 1. An optical element comprising the anisotropic film according to claim 4.

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