JP2006079030A - Dye for anisotropic dye film, dye composition for anisotropic dye film, anisotropic dye film, and polarizing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an anisotropic dye film having high dichroism and to provide a polarizing device having an anisotropic dye film and having excellent heat resistance, light resistance and polarizing performance. <P>SOLUTION: The anisotropic dye film having a cycle (d), ascribed to molecular lamination, of ≤3.445Å and a lamination length (L) of ≥105Å. The anisotropic dye film exhibits an orientation degree of the molecular lamination axis of ≥85%, a film thickness of ≤30 μm and is preferably produced by a wet film formation method. The film exhibits high dichroism by possessing a molecular arrangement suitable for developing a dichroic ratio. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention particularly relates to an anisotropic dye film exhibiting high dichroism useful for a polarizing plate provided in a display element of a light control element, a liquid crystal element, or an organic electroluminescence element (OLED), and the anisotropic dye The present invention relates to a polarizing element using a film and a dye composition for an anisotropic dye film for obtaining the anisotropic dye film. The present invention also relates to a novel azo dye useful for anisotropic dye films.

  In an LCD (liquid crystal display), a linearly polarizing plate and a circularly polarizing plate are used to control optical rotation and birefringence in display. In the OLED, a circularly polarizing plate is used for preventing reflection of external light.

  Conventionally, these polarizing plates have iodine or dichroic organic dye dissolved or adsorbed in a polymer material such as polyvinyl alcohol, and the film is stretched in one direction to form a dichroic dye. Anisotropic dye films obtained by orienting the liquid crystal have been widely used (for example, Patent Documents 1 to 3). However, the conventional anisotropic dye film produced in this way does not have sufficient heat resistance or light resistance depending on the dye or polymer material used; yield of bonding of the anisotropic dye film when manufacturing a liquid crystal device There were problems such as; Moreover, since iodine has a high sublimation property, when it was used as a polarizing plate, its heat resistance and light resistance were not sufficient. In addition, the extinction color is deep blue, and it cannot be said to be an ideal achromatic polarizing plate over the entire visible spectrum region.

  Therefore, a film containing a dichroic dye is formed on a substrate such as glass or a transparent film by a wet film-forming method in which a solution containing a dichroic dye is applied, and two colors are used by utilizing intermolecular interaction. A method of producing an anisotropic dye film by orienting a neutral dye (for example, see Patent Documents 4 to 9 and Non-Patent Documents 1 to 3) has been studied.

  In applications as polarizing elements, anisotropic dye films with high dichroism are required to obtain higher polarization performance, but these conventional anisotropic dye films are inferior in dichroism, For this reason, a polarizing element excellent in polarization performance could not be obtained.

Conventionally, various dyes have been used for anisotropic dye films, and the selection of the dye is one of the important factors. For example, Patent Document 1 describes that a dichroic dye represented by the following structural formula is used.

Patent Document 2 describes that a dichroic dye represented by the following structural formula is used.

  However, both of the compounds described in Patent Document 1 and Patent Document 2 have insufficient dichroism, and in particular, the compound described in Patent Document 1 has low solubility in various solvents. It cannot be said that it is sufficient as a material for the anisotropic dye film produced by the above method.

Furthermore, Patent Document 6 also describes that a dichroic dye represented by the following structural formula is used.

  However, all of the above compounds are disazo compounds, and there is a problem that dichroism and solubility in a solvent are insufficient as materials for anisotropic dye films produced by a wet film formation method. .

Patent Document 9 describes that an anisotropic dye film produced by a wet film-forming method is prepared, and an example of a dichroic dye that can be used is described by the following structural formula. Has been.

However, the above compound is a disazo compound and has a problem that it is easily decomposed because a halogen atom is bonded to the triazine ring.
Japanese Patent Laid-Open No. 3-12606 JP-A-1-161202 JP-A-1-252904 US Pat. No. 2,400,877 JP-T 8-511109 JP-T-2002-528758 JP 2002-180052 A JP 2002-338838 A WO02 / 099480 Dreyer, JF, Phys. And Colloid Chem., 1948, 52, 808., “The Fixing of Molecular Orientation” Dreyer, JF, Journal de Physique, 1969, 4, 114., “Light Polarization From Films of Lyotropic Nematic Liquid Crystals” Supervised by Masahiro Irie “Application of functional dyes” CMC Publishing Co., Ltd., April 15, 1996, pages 96 to 106

  An object of the present invention is to provide an anisotropic dye film having high dichroism and a polarizing element having excellent heat resistance, light resistance, and polarization performance using the anisotropic dye film. Another object is to provide a novel dichroic dye and a dye composition for an anisotropic dye film that can realize an anisotropic dye film that functions as an anisotropic dye film having heat resistance and light resistance. To do.

  As a result of intensive studies, the present inventors have found that an anisotropic dye film having high dichroism can be reliably realized by specifying the crystal structure parameter of the anisotropic dye film, and the present invention has been achieved. did.

  That is, the anisotropic dye film of the present invention is characterized in that the period derived from the molecular stack is 3.445 mm or less and the stack length is 105 mm or more.

  In addition, as a novel dichroic azo dye, the present inventors have a triazinyl group represented by the following general formula (1) and have a specific structure having 3 or more azo bonds in one molecule. It has been found that the dichroic azo dye has a high affinity with the substrate. In addition, by using a composition containing such a dye and forming a film by a wet film forming method, the dichroic dye molecule exhibits a high-order molecular orientation state, that is, has high anisotropy. It has been found that a dye film can be formed.

（式中、Ａ^０、Ｂ^０、Ｃ^０およびＤ^０は、それぞれ独立に、置換基を有していても良い芳香族炭化水素環を表し、
Ａｒ^０は水素原子、または任意の置換基を表し、
Ｘ^０およびＹ^０はそれぞれ独立に、ハロゲン原子以外の任意の置換基を表す。
ｋは１または２を表し、ｍは１または２を表す。なお、ｋが２の場合、１分子中に含まれる複数のＢ^０は、同一であっても異なっていても良い。） That is, the azo dye of the present invention contains an azo dye whose free acid form is represented by the following general formula (1).

(In the formula, A ⁰ , B ⁰ , C ⁰ and D ⁰ each independently represents an aromatic hydrocarbon ring which may have a substituent,
Ar ⁰ represents a hydrogen atom or an arbitrary substituent,
X ⁰ and Y ⁰ each independently represent an arbitrary substituent other than a halogen atom.
k represents 1 or 2, and m represents 1 or 2. When k is 2, a plurality of B ⁰ contained in one molecule may be the same or different. )

  Furthermore, the present inventors use an azo dye represented by the following general formula (2), so that an anisotropic dye film formed by a wet film forming method is achromatic, has high dichroism, and high It was found that the degree of molecular orientation can be shown.

（式中、Ｄ^１およびＥ^１は、置換基を有していても良いフェニレン基、または置換基を有していても良いナフチレン基を表し、
Ｇ^１はカルボキシ基、スルホ基、またはリン酸基を表し、
Ｑ^１はハロゲン原子、水酸基、ニトロ基、置換基を有していても良いアミノ基、置換基を有していても良い炭素数１〜４のアルキル基、置換基を有していても良い炭素数１〜３のアルコキシ基、カルボキシル基、或いはスルホ基を表し、
Ｑ^２およびＱ^３はそれぞれ独立に、水素原子、置換基を有していても良い炭素数１〜４のアルキル基、或いは置換基を有していても良いフェニル基を表し、
ｐは０または１を表し、ｔは１または２を表す。） That is, the azo dye of the present invention is an azo dye for an anisotropic dye film formed by a wet film forming method, and the free acid form is represented by the following general formula (2). .

(In the formula, D ¹ and E ¹ represent a phenylene group which may have a substituent, or a naphthylene group which may have a substituent,
G ¹ represents a carboxy group, a sulfo group, or a phosphate group,
Q ¹ may have a halogen atom, a hydroxyl group, a nitro group, an amino group which may have a substituent, an alkyl group having 1 to 4 carbon atoms which may have a substituent, or a substituent. Represents an alkoxy group having 1 to 3 carbon atoms, a carboxyl group, or a sulfo group;
Q ² and Q ³ each independently represent a hydrogen atom, an optionally substituted alkyl group having 1 to 4 carbon atoms, or an optionally substituted phenyl group,
p represents 0 or 1, and t represents 1 or 2. )

The dye composition for an anisotropic dye film of the present invention contains the azo dye of the present invention.
The anisotropic dye film of the present invention is also characterized by containing the azo dye of the present invention.
The anisotropic dye film of the present invention is also characterized by being formed using the above-described dye composition for anisotropic dye film of the present invention.
The polarizing element of the present invention is characterized by using the anisotropic dye film of the present invention.

  According to the present invention, an anisotropic dye film having high dichroism can be provided. By using this highly dichroic anisotropic dye film, a polarizing element having excellent heat resistance and light resistance and excellent polarization performance can be provided.

Hereinafter, embodiments of the present invention will be described in detail.
The description of the constituent elements described below is an example (representative example) of an embodiment of the present invention, and the present invention is not specified in these contents unless it exceeds the gist.

  The anisotropic dye film referred to in the present invention is 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 dye film and any two orthogonal in-plane directions. A dye film having Examples of electromagnetic properties 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 linear polarizing film, a circular polarizing film, a retardation film, and a resistivity anisotropic film. That is, the anisotropic dye film of the present invention can be used for a polarizing film, a retardation film, or a resistivity anisotropic film. In particular, since the anisotropic dye film of the present invention has absorption in the visible light region, it is useful for a polarizing film.

  The anisotropic dye film of the present invention has a period derived from molecular lamination of 3.445 mm or less and a lamination length of 105 mm or more.

  The reason why the anisotropic dye film of the present invention having a molecular stacking period of 3.445 mm or less and a molecular stacking length of 105 mm or more exhibits high dichroism is estimated as follows.

It is known that a dye molecule generally has a planar molecular structure formed by an aromatic ring and becomes a crystal having a laminated structure in which molecular planes are overlapped by strong intermolecular interactions such as π-π interaction. . In the case of an anisotropic dye film, as described in Non-Patent Documents 4 and 5 below, a diffraction peak derived from the lamination period of the dye molecule laminated structure is observed together with other diffraction peaks by X-ray diffraction measurement. The
Non-Patent Document 4: M. Ofuji et.al., Jpn.J.Appl.Phys.2002,41,5467 “Grazing Incidence In-Plane X-Ray Diffraction Study on Oriented Copper Phthalocyanine Thin Films”
Non-Patent Document 5: M. Ofuji et.al., Jpn. J. Appl. Phys. 2003, 42, 7520 “Growth Process of Vacuum Deposited Copper Phthalocyanine Thin Films on Rubbing-Treated Substrates”

  The molecular lamination period obtained from this X-ray diffraction peak analysis shows a value reflecting the lamination and arrangement state of the dye molecules in the crystal. In particular, the inclination of the dye molecule plane with respect to the stacking axis is estimated to be important for the molecular stacking period.

Hereinafter, the molecular lamination period and the lamination length of the anisotropic dye film and the dichroism of the anisotropic dye film will be described with reference to FIGS.
1, 2, 3 (a) and 3 (b) are schematic views showing the arrangement of dichroic dye molecules of the anisotropic dye film as viewed from above the film surface of the anisotropic dye film. 1 to 3, a broken line indicates a molecular stacking axis, and a black thick line segment indicates a dye molecule having a planar molecular structure. 1 and 2, d is a molecular stacking period, dm is the shortest distance between stacked molecules, and L is a stacking length. Further, when the absorption direction in the plane of the anisotropic dye film is taken as the x axis and the polarization direction is taken as the y axis, k ₀ is the absorption coefficient of the dye projected on the xy plane, and k _x and k _y are the absorption coefficients. It becomes an x-axis and y-axis direction component.

  FIG. 1 shows an anisotropic dye film in which molecules are arranged in a state in which the dye molecule plane is inclined from the perpendicular to the molecular stacking axis. FIG. 2 shows molecules arranged in a state where the molecular plane is perpendicular to the molecular stacking axis. Each of the anisotropic dye films is shown. Here, it is assumed that the closest distance dm that the molecular planes can take due to intermolecular interactions such as π-π interaction is substantially constant. At this time, as shown in FIG. 1, when the molecular plane is largely inclined from the perpendicular to the molecular stacking axis, the molecular stacking period d becomes d> dm correspondingly and becomes a larger value. As shown in FIG. 2, when the molecular plane is perpendicular to the molecular stacking axis, d = dm, and the value of the molecular stacking period d is expected to be small.

On the other hand, the dichroic ratio of the anisotropic dye film is determined by the ratio between the absorption coefficient in the absorption direction and the polarization direction. Accordingly, when the absorption direction in the plane of the anisotropic dye film is the x axis and the polarization direction is the y axis, the x axis component k _{x of the} extinction coefficient of the dichroic dye used is used for the purpose of increasing the dichroic ratio. It is preferable that a large number of molecular arrangements are prepared so that is as large as possible.

In general, the absorption axis of the dichroic dye is substantially coincident with the molecular stacking axis direction (Non-patent Document 3: supervised by Masahiro Irie “Application of Functional Dye”, CMC Publishing Co., Ltd., issued April 15, 1996 96)) in the molecular plane. Here, when the absorption coefficient of the dichroic dye projected onto the xy plane is k ₀ , when the molecular plane is perpendicular to the molecular stacking axis (FIG. 2), k _x = k ₀ and the molecular plane is inclined. It becomes larger than k _x (<k ₀ ) in the case (FIG. 1). Accordingly, an anisotropic dye film having a molecular plane closer to the vertical inclination with respect to the stacking axis, that is, having a smaller molecular stacking period d, is preferable from the viewpoint of improving dichroism because the value of the absorption coefficient k _x is larger. Conceivable.

  Further, from the X-ray diffraction peak analysis, the stacking length (L in FIGS. 1 and 2), which is the stacking distance of the periodically arranged molecules, can be estimated at the same time. At this time, the number of dye molecules included in the stacking length and arranged in the same direction is L / d. As described above, in order to obtain a high dichroic ratio, it is necessary to align a large number of molecules in an optimal arrangement. Therefore, an anisotropic dye film having a large number of laminated molecules L / d, that is, a larger laminated length L is preferable. Conceivable.

  From the above considerations, the present inventors have a molecular arrangement that can express a high dichroic ratio by using a portion having a molecular lamination period of 3.445 mm or less and a lamination length of 105 mm or more as parameters. It was found that an anisotropic dye film was obtained.

  On the other hand, as the conventional anisotropic dye film, a film that deviates from the parameter has been used. That is, in the conventional anisotropic dye film, it is presumed that a high dichroic ratio could not be obtained because a large number of dichroic dye molecules were not arranged in the optimum direction for dichroic ratio expression. .

  In the anisotropic dye film of the present invention defined by the above parameters, the degree of orientation of the molecular stacking axis shown in FIG. 3 is also important for the expression of high dichroism. That is, in order to arrange more molecules in the same direction, it is desirable that the degree of orientation of the molecular stacking axis is also high. For this reason, it is preferable that the degree of orientation estimated by the X-ray diffraction measurement mentioned later is 85% or more for the anisotropic dye film of the present invention.

  The molecular lamination period of the anisotropic dye film of the present invention is preferably 3.300 mm or more, more preferably 3.380 mm or more, most preferably 3.400 mm or more, 3.445 mm or less, preferably 3.440 mm or less. More preferably, it is 3.435 mm or less. When the molecular lamination period of the anisotropic dye film exceeds this upper limit, the inclination of the molecules in the molecular lamination becomes large and the dichroic ratio may be lowered, which is not preferable. On the other hand, if the value is below the lower limit, the molecules are too close to each other, which may hinder the molecular stacking.

  The molecular length of the anisotropic dye film of the present invention is 105 mm or more, preferably 115 mm or more, more preferably 140 mm or more, preferably 1 μm or less, more preferably 500 nm or less, and most preferably 100 nm or less. . If the molecular lamination length of the anisotropic dye film exceeds this upper limit, the crystal structure is liable to be distorted and the orientation degree of the molecular lamination axis may be lowered, which is not preferable. On the other hand, if the value is below the lower limit, the number of molecules arranged in the same direction is small, so that a high dichroic ratio may not be expressed, which is not preferable.

  The above parameters of the anisotropic dye film, that is, the values of the molecular stacking period and the stacking length are the same as the X-ray diffractometer for thin film evaluation (“RINT2000PC” in-plane optical system manufactured by Rigaku Corporation) or an equivalent device. (See, for example, Non-Patent Documents 4 and 5).

  In the anisotropic dye film of the present invention, these are obtained, for example, by the following procedures (1) to (3).

(1) First, in-plane measurement is performed on the anisotropic dye film from two directions in which the diffraction plane perpendicular to the absorption axis and the diffraction plane perpendicular to the polarization axis are observed. In the anisotropic dye film of the present invention, a strong diffraction peak derived from the molecular stacking period is from two directions at a diffraction angle (2θ _χ ) of about 24.7 ° to about 27 ° with respect to CuCα. It is usually observed only in measurements from one of the in-plane measurements.

The X-ray diffraction profile of the (2) peak derived from the molecular accumulation was observed direction, the range from 2 [Theta] _chi is 20 ° to 30 °, performs best fit the following equation f (2 [Theta] _{chi).
f (2θ χ) = B (} 2θ χ) + C 1 exp [- ((2θ χ -2θ 1) / 2σ 1) 2]
_{+ C 2 exp [- ((} 2θ χ -2θ 2) / 2σ 2) 2]
That is, in the anisotropic dye film of the present invention, the above formula described by two Gaussian functions is used on the assumption that the periodically stacked crystal portions and the randomly stacked amorphous portions coexist.
However, C ₁ and C ₂ represent the coefficients, 2θ ₁ and 2θ ₂ represent the peak positions, and σ ₁ and σ ₂ represent the standard deviation.
Further, B (2 [Theta] _chi) denotes the baseline, where, X-rays diffraction profile in the direction of the diffraction peak derived from a molecular lamination is not observed and baseline. However, if there is a diffraction peak from another diffraction surface in this diffraction peak, the peak is removed and interpolated to obtain a baseline.

(3) Since the parameter obtained in the present invention is a structural parameter of a crystal portion in which molecules are periodically stacked, when σ ₁ <σ ₂ , the peak position of the diffraction peak is 2θ ₁ , and the half width of the peak is β ₁ = 2σ ₁ √ (2ln2). Molecular stacking period d is estimated from the following Bragg condition from the peak position 2 [Theta] _1.
d = λ / (2 sin θ ₁ )
Where λ is the X-ray wavelength (= 1.54Å).
The stacking length L is estimated from the following Scherrer equation from the half-value width β (= β ₁ × π / 180 rad).
L = Kλ / (βcosθ ₁ )
However, K is a Scherrer constant, and a value of K = 1 is used here.

The degree of orientation of the molecular lamination axis of the anisotropic dye film can also be obtained from the measurement using the above-mentioned apparatus, for example, as follows (for example, see Non-Patent Documents 4 and 5). That is, when the in-plane rocking scan measurement is performed over 360 ° with respect to the diffraction peak observed in the in-plane measurement, two peaks corresponding to the orientation of the molecular stacking axis are normally observed in the anisotropic dye film of the present invention. Is done. The locking profile is optimally fitted by the following equation g (φ).
g (φ) = C ₀ + C ₁ exp [− ((φ−φ ₁ ) / 2σ ₁ ) ² ]
+ C ₂ exp [− ((φ−φ ₂ ) / 2σ ₂ ) ² ]
However, C ₀ , C ₁ and C ₂ are coefficients, φ is a rotation angle, φ ₁ and φ ₂ are peak positions, and σ ₁ and σ ₂ are standard deviations.
The degree of orientation P (unit:%) of the molecular stacking axis in the present invention is defined by the following formula.
P = (360-2σ ₁ −2σ ₂ ) / 360 × 100

  The anisotropic dye film of the present invention preferably has an orientation degree of the molecular stacking axis defined as described above of 85% or more. The degree of orientation is more preferably 88% or more, most preferably 90% or more, and particularly preferably 94% or more. If the degree of orientation is less than the lower limit, the number of molecules arranged in the same direction is small, so that a high dichroic ratio may not be expressed, which is not preferable.

  The anisotropic dye film of the present invention satisfying these parameters exhibits a high dichroic ratio, but the dichroic ratio is preferably 11 or more, more preferably 13 or more, and most preferably 15 or more.

  The film thickness of the anisotropic dye film of the present invention is usually a film thickness after drying, preferably 10 nm or more, more preferably 50 nm or more, preferably 30 μm or less, more preferably 1 μm or less. If the thickness of the anisotropic dye film exceeds 30 μm, it may be difficult to obtain uniform orientation of the dye molecules within the film, and if it is less than 10 nm, it may be difficult to obtain a uniform film thickness. Therefore, it is not preferable.

  An anisotropic dye film having a period derived from molecular stacking of 3.445 mm or less and a stack length of 105 mm or more is obtained by selecting a combination of dyes and additives contained in the anisotropic dye film. I can do it. Of course, the production method of the anisotropic dye film is one of the important elements for obtaining the anisotropic dye film, and in order to obtain the anisotropic dye film, a wet film forming method should be used. Is preferred.

  Examples of the dye used in the anisotropic dye film of the present invention include azo dyes, stilbene dyes, cyanine dyes, phthalocyanine dyes, and condensed polycyclic dyes (perylene-based and oxazine-based). Among these dyes, an azo dye that can take a high molecular arrangement in the anisotropic dye film is particularly preferable as the optimum dye for obtaining the anisotropic dye film of the present invention. A dye represented by the following general formula (1) or (2) is particularly preferable.

  An azo dye means a dye having at least one azo group. The number of azo groups in one molecule is preferably 1 or more, more preferably 2 or more, preferably 6 or less, and more preferably 4 or less, from the viewpoint of color tone and production.

  Such a dye is preferably water-soluble for use in the wet film-forming method described later. Therefore, as a substituent that imparts water solubility, a dye having an acidic group such as a sulfo group, a carboxyl group, or a phosphoric acid group, a basic group such as an amino acid group, or a soluble group such as a hydroxyl group is preferable. In particular, it preferably has a sulfo group or a carboxyl group.

  The molecular weight of such a dye is usually 200 or more, particularly 350 or more, and usually 5000 or less, particularly 3500 or less in a free state that does not take a salt form, from the viewpoints of color tone and production.

  Specific examples of such a dye include the aforementioned Patent Document 4 (US Pat. No. 2,400,877) and Non-Patent Document 1 (Dreyer, JF, Phys. And Colloid Chem., 1948, 52,808., “The Fixing of Molecular Orientation "), Non-Patent Document 2 (Dreyer, JF, Journal de Physique, 1969, 4, 114.," Light Polarization From Films of Lyotropic Nematic Liquid Crystals ") and Non-Patent Document 6 (J. Lyndon," Chromonics " in “Handbook of Liquid Crystals Vol.2B: Low Molecular Weight Liquid Crystals II”, D. Demus, J. Goodby, GWGray, HWSpiessm, V. Villed., Willey-VCH, P. 981-1007, (1998) ).

（式中、Ａ^０、Ｂ^０、Ｃ^０およびＤ^０は、それぞれ独立に、置換基を有していても良い芳香族炭化水素環を表し、
Ａｒ^０は水素原子、または任意の置換基を表し、
Ｘ^０およびＹ^０はそれぞれ独立に、ハロゲン原子以外の任意の置換基を表す。
ｋは１または２を表し、ｍは１または２を表す。なお、ｋが２の場合、１分子中に含まれる複数のＢ^０は、同一であっても異なっていても良い。） In particular, the anisotropic dye film of the present invention preferably contains a novel azo dye whose free acid form is represented by the following general formula (1).

(In the formula, A ⁰ , B ⁰ , C ⁰ and D ⁰ each independently represents an aromatic hydrocarbon ring which may have a substituent,
Ar ⁰ represents a hydrogen atom or an arbitrary substituent,
X ⁰ and Y ⁰ each independently represent an arbitrary substituent other than a halogen atom.
k represents 1 or 2, and m represents 1 or 2. When k is 2, a plurality of B ⁰ contained in one molecule may be the same or different. )

  This azo dye exhibits dichroism, is excellent in color tone and solubility in a solvent, and is highly stable in solution. Therefore, it can be used for various applications, but when used for an anisotropic dye film, a particularly high effect can be obtained. That is, the anisotropic dye film of the present invention using this dye exhibits high dichroism and at the same time has higher heat resistance and light resistance than conventional iodine-based polarizing films.

  In particular, as described above, since the solubility in a solvent and the stability in a solution are high, the storage stability of the dye composition for an anisotropic dye film containing the dye is high. Therefore, the azo dye of the present invention is preferably applied to the formation of an anisotropic dye film by a wet film forming method described later. According to the wet film forming method, an anisotropic dye film can be formed on a high heat resistant substrate such as glass, and a high heat resistant polarizing element can be obtained. The point which can be used for the use as which high heat resistance is calculated | required, such as a display panel, is preferable.

In the above general formula (1), examples of the aromatic hydrocarbon ring of A ^{0 to} D ⁰ include aromatic hydrocarbon rings having about 6 to 20 carbon atoms, preferably each independently a benzene ring or a naphthalene ring. . Among these, D ⁰ is more preferably a 1,4-phenylene group when D ⁰ is a benzene ring, and it is preferably a 2,6-naphthylene group when it is a naphthalene ring. Further, a divalent group derived from a 1-naphthol ring or a 2-naphthol ring is more preferable, and a group derived from a 1-naphthol ring is particularly preferable from the viewpoint of obtaining a dye having a deep color.

Examples of the substituent that the aromatic hydrocarbon ring of A ^{0 to} D ⁰ may have include a group appropriately selected from an electron-withdrawing group and an electron-donating group introduced to adjust the color tone, and solubility in a solvent. And hydrophilic groups to be introduced for enhancing the properties. Specifically, such groups listed as the substituents which may have the A ¹ -C ¹ in the formula (1-a) to be described later and the like.

Ar ⁰ optionally includes a group selected appropriately from an electron-withdrawing group and an electron-donating group introduced to adjust the color tone, and a hydrophilic group introduced to enhance solubility in a solvent. Groups and the like. Specific examples include groups exemplified as Ar ¹ in the general formula (1-a) described later.

Examples of the optional substituent other than the halogen atoms of X ⁰ and Y ⁰ include a hydrophilic group and a hydrophobic group introduced to adjust the solubility in a solvent. Specific examples include groups exemplified as X ¹ and Y ¹ in the general formula (1-a) described later.

（式中、Ａ^１は、置換基を有していても良いフェニル基、または置換基を有していても良いナフチル基を表し、
Ｂ^１およびＣ^１はそれぞれ独立に、置換基を有していても良いフェニレン基、または置換基を有していても良いナフチレン基を表し、
Ａｒ^１は水素原子、または置換基を有していても良い炭素数１〜５のアルキル基を表し、
Ｘ^１およびＹ^１はそれぞれ独立に、−ＮＲ^１Ｒ^２基、−ＯＲ^３基、または−ＳＲ^４基を表す。
但し、Ｒ^１、Ｒ^２、Ｒ^３およびＲ^４はそれぞれ独立に、水素原子、置換基を有していても良い炭素数１〜１８のアルキル基、置換基を有していても良い炭素数２〜１８のアルケニル基、置換基を有していても良い炭素数３〜１５の炭化水素環基、または置換基を有していても良い５または６員環の、単環または２〜３縮合環からなる複素環基を表すか、あるいはＲ^１とＲ^２とが互いに結合し、窒素原子を含む５または６員環を形成する。Ｒ^１およびＲ^２が結合してなる環は、置換基を有していても良い。
ｋは１または２を表し、ｍは１または２を表す。なお、ｋが２の場合、１分子中に含まれる複数のＢ^１は、同一であっても異なっていても良い。） The azo dye of the present invention represented by the general formula (1) preferably has a free acid form represented by the following general formula (1-a).

(In the formula, A ¹ represents a phenyl group which may have a substituent, or a naphthyl group which may have a substituent;
B ¹ and C ¹ each independently represent a phenylene group which may have a substituent, or a naphthylene group which may have a substituent,
Ar ¹ represents a hydrogen atom or an optionally substituted alkyl group having 1 to 5 carbon atoms,
X ¹ and Y ¹ each independently represent a —NR ¹ R ² group, a —OR ³ group, or a —SR ⁴ group.
However, R ¹ , R ² , R ³ and 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 optionally substituted hydrocarbon ring group having 3 to 15 carbon atoms, an optionally substituted 5- or 6-membered ring, monocyclic ring or 2-3 It represents a heterocyclic group consisting of a condensed ring, or R ¹ and R ² are bonded to each other to form a 5- or 6-membered ring containing a nitrogen atom. The ring formed by bonding R ¹ and R ² may have a substituent.
k represents 1 or 2, and m represents 1 or 2. When k is 2, a plurality of B ¹ contained in one molecule may be the same or different. )

In the general formula (1-a), A ¹ represents a phenyl group which may have a substituent or a naphthyl group which may have a substituent.

When A ¹ is a phenyl group, the phenyl group may have a sulfo group, a carboxyl group, a hydroxyl group, a nitro group, a halogen atom, an amino group which may have a substituent, or a substituent. Examples thereof include an alkyl group and an alkoxy group which may have a substituent.

Specifically, as a halogen atom, amino group, alkyl group and alkoxy group,
A halogen atom which is a fluorine atom, a chlorine atom, a bromine atom or an iodine atom;
An amino group;
An alkylamino group having 1 to 18 carbon atoms (preferably 1 to 8 carbon atoms), such as an N-methylamino group, an N, N-dimethylamino group, or an N, N-diethylamino group;
An arylamino group having 6 to 18 carbon atoms (preferably 6 to 10 carbon atoms), such as an N-phenylamino group or an N-naphthylamino group;
An acylamino group having 2 to 18 carbon atoms (preferably 2 to 11), such as an acetylamino group or a benzoylamino group;
An alkyl group having 1 to 18 carbon atoms (preferably 1 to 12) such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, and an n-dodecyl group;
An alkoxy group having 1 to 18 carbon atoms (preferably 1 to 12 carbon atoms) such as a methoxy group, an ethoxy group, an i-propoxy group, an n-butoxy group and an n-dodecyloxy group;
Etc.

  The various amino groups, alkyl groups, and alkoxy groups described above may have a substituent, and examples of the substituent include a hydroxyl group and an alkoxy group.

In the case where A ¹ is an optionally substituted phenyl group, the phenyl group has a sulfo group, a carboxyl group, a halogen atom, and a substituent from the viewpoint of solubility in solvents and color tone. An amino group that may be substituted, an alkyl group that may have a substituent, and an alkoxy group that may have a substituent are more preferable, and a sulfo group, a carboxyl group, an acylamino group, and an alkyl group are particularly preferable. preferable. If A ¹ is a phenyl group, a phenyl group preferably has 1 to 3 substituents selected from these substituents.

When A ¹ is a naphthyl group, the substituent of the naphthyl group is preferably a sulfo group, a carboxyl group, a hydroxyl group, etc., and this naphthyl group has 1 to 3 substituents selected from these substituents. It is preferable. A particularly preferred substituent is a sulfo group.

B ¹ and C ¹ each independently represent a phenylene group which may have a substituent or a naphthylene group which may have a substituent, and the phenylene group is preferably a 1,4-phenylene group, The naphthylene group is preferably a 1,4-naphthylene group.

When B ¹ and C ¹ are a phenylene group, examples of the substituent that may be included include a sulfo group, a carboxyl group, an alkyl group that may have a substituent, an alkoxy group that may have a substituent, and a substituent. An amino group which may have a hydrogen atom is preferred.

Specific examples of the alkyl group, alkoxy group and amino group include, for example,
An alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, and an n-butyl group;
An alkoxy group having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a hydroxyethoxy group, an n-propoxy group, an i-propoxy group and an n-butoxy group;
An amino group;
An alkylamino group having 1 to 8 carbon atoms, such as an N-methylamino group, an N, N-dimethylamino group, or an N, N-diethylamino group;
An arylamino group such as an N-phenylamino group;
An acylamino group having 2 to 8 carbon atoms, such as an acetylamino group and a benzoylamino group;
Etc.

  The aforementioned alkyl group, alkoxy group, and various amino groups may have a substituent, and examples of the substituent include a hydroxyl group, an alkoxy group, a halogen atom, and the like.

In the case where B ¹ and C ¹ are phenylene groups which may have a substituent, the substituent of the phenylene group includes a sulfo group, a carboxyl group, an alkyl group which may have a substituent, An alkoxy group which may have a group and an acylamino group which may have a substituent are preferable. From the viewpoint of hydrophobic bonding (intermolecular interaction) and color tone, an alkyl group, an alkoxy group and an acylamino group are Particularly preferred.

In the case where B ¹ and C ¹ are phenylene groups, it preferably has 1 to 3 substituents represented by the above substituents, and more preferably has 1 to 2 substituents. preferable.

When B ¹ and C ¹ are naphthylene groups, examples of the substituent for the naphthylene group include a hydroxyl group, a sulfo group, and an alkoxy group that may have a substituent.

  Specifically as an alkoxy group, C1-C4 alkoxy groups, such as a methoxy group and an ethoxy group, are mentioned, for example. The substituent that the alkoxy group may have is preferably a hydroxyl group, a hydroxyalkyl group, or an alkoxy group.

The naphthylene group of B ¹ and C ¹ preferably has 1 to 6 substituents selected from these substituents, and more preferably has 1 to 3 substituents. The substituent that the naphthylene group of B ¹ and C ¹ has is particularly preferably a sulfo group or an alkoxy group that may have a substituent.

Ar ¹ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms which may have a substituent, and preferably an alkyl group having 1 to 4 carbon atoms which may have a hydrogen atom or a substituent. (For example, a methyl group, an ethyl group, an ethyl group, or the like, or a group in which these are further substituted). Particularly preferred is a hydrogen atom. Examples of the substituent that the alkyl group may have include a hydroxyl group, a sulfo group, and a carboxyl group.

X ¹ and Y ¹ each independently represent a —NR ¹ R ² group, —OR ³ group, or —SR ⁴ group, wherein R ¹ , R ² , R ^3, and R ⁴ each independently represent a hydrogen atom , An alkyl group which may have a substituent, an alkenyl group which may have a substituent, a hydrocarbon ring group which may have a substituent (aryl group or alicyclic group), or a substituent Represents a heterocyclic group which may have a group.

In particular,
Hydrogen atom;
An alkyl group having 1 to 18 carbon atoms (preferably 1 to 12), such as a methyl group, an ethyl group, an i-propyl group, an n-butyl group, an n-octyl group, or an n-dodecyl group;
An alkenyl group having 2 to 18 carbon atoms (preferably 2 to 8 carbon atoms) such as a vinyl group and an allyl group;
An aryl group having 6 to 18 (preferably 6 to 12) carbon atoms, such as a phenyl group or a naphthyl group;
An alicyclic group having 6 to 18 carbon atoms (preferably 6 to 10 carbon atoms), such as a cyclohexyl group or a cyclohexenyl group;
An aromatic or non-aromatic heterocyclic group consisting of a 5- or 6-membered monocyclic ring or a 2-3 condensed ring, such as pyridyl group, thiadiazolyl group, benzothiazolyl group, morpholinyl group, piperidinyl group, piperazinyl group,
Etc.

  Examples of the substituent that the alkyl group, alkenyl group, aryl group, alicyclic group, and heterocyclic group may have include a hydroxyl group, a carboxyl group, a sulfo group, and an aryl group, and more preferably a hydroxyl group, It is a carboxyl group or a sulfo group.

As R ¹ and R ² , a hydrogen atom, an alkyl group which may have a substituent, or an aryl group which may have a substituent is more preferable, and an aryl group which may have a substituent Is particularly preferred.

Moreover, it is preferable that ^one of R ¹ and R ² is a hydrogen atom and the other is other than a hydrogen atom.

R ³ and R ⁴ are preferably a hydrogen atom or an alkyl group which may have a substituent.

X ¹ and Y ¹ are both —NR ¹ R ² groups (wherein R ¹ and R ² may be the same or different), or one of them is —NR ¹ R ² group. More preferably, the other is a —OR ³ group.

X ¹ and Y ¹ may be bonded to each other to form a nitrogen-containing ring which may have a substituent, and R ¹ and R ² are bonded to each other to contain a nitrogen atom. When a member ring is formed, this ring is preferably a morpholine ring, piperazine ring or piperidine ring.

k represents 1 or 2, and m represents 1 or 2. When k is 2, a plurality of B ¹ contained in one molecule may be the same or different.

（式中、Ａ^２は置換基を有していても良いフェニル基、または置換基を有していても良いナフチル基を表し、
Ｂ^２およびＣ^２はそれぞれ独立に、置換基を有していても良いフェニレン基、または置換基を有していても良いナフチレン基を表し、
Ａｒ^２は水素原子、置換基を有していても良い炭素数１〜４のアルキル基を表し、
Ｘ^２およびＹ^２はそれぞれ独立に、−ＮＲ^５Ｒ^６基、−ＯＲ^７基、または−ＳＲ^８基を表す。
但し、Ｒ^５、Ｒ^６、Ｒ^７およびＲ^８はそれぞれ独立に、水素原子、置換基を有していても良い炭素数１〜１８のアルキル基、置換基を有していても良い炭素数２〜１８のアルケニル基、置換基を有していても良い炭素数３〜１５の炭化水素環基、または置換基を有していても良い５または６員環の、単環または２〜３縮合環からなる複素環基を表すか、あるいはＲ^５とＲ^６とが互いに結合し、窒素原子を含む５または６員環を形成する。なお、Ｒ^５およびＲ^６が結合してなる環は、置換基を有していても良い。
ｋは１または２を表し、ｎは０または１を表す。なお、ｋが２の場合、１分子中に含まれる複数のＢ^２は、同一であっても異なっていても良い。） In the azo dye of the present invention represented by the general formula (1), more preferably, the free acid form is represented by the following general formula (1-b).

(In the formula, A ² represents a phenyl group which may have a substituent, or a naphthyl group which may have a substituent,
B ² and C ² each independently represent a phenylene group which may have a substituent, or a naphthylene group which may have a substituent,
Ar ² represents a hydrogen atom, an optionally substituted alkyl group having 1 to 4 carbon atoms,
X ² and Y ² each independently represent a —NR ⁵ R ⁶ group, a —OR ⁷ group, or a —SR ⁸ group.
However, R ⁵ , R ⁶ , R ⁷ and R ⁸ 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 optionally substituted hydrocarbon ring group having 3 to 15 carbon atoms, an optionally substituted 5- or 6-membered ring, monocyclic ring or 2-3 It represents a heterocyclic group consisting of a condensed ring, or R ⁵ and R ⁶ are bonded to each other to form a 5- or 6-membered ring containing a nitrogen atom. In addition, the ring formed by bonding R ⁵ and R ⁶ may have a substituent.
k represents 1 or 2, and n represents 0 or 1. When k is 2, the plurality of B ² contained in one molecule may be the same or different. )

Examples of preferable substituents for A ² , B ² , C ² , Ar ² , X ² , and Y ^{2 in} the general formula (1-b) include A ¹ in the general formula (1-a), The same as those exemplified as preferred substituents for B ¹ , C ¹ , Ar ¹ , X ¹ and Y ¹ .

  The azo dye of the present invention represented by the general formula (1) is, for example, a trisazo dye when k = 1 in the general formulas (1), (1-a), and (1-b), and k When = 2, it is a tetrakisazo dye. From the viewpoint of ease of synthesis and availability of raw materials in industrial production, k = 1, that is, a trisazo dye is preferable, and when used in an anisotropic dye film as described later, intermolecular From the viewpoint that the interaction is considered to work more strongly, k = 2, that is, a tetrakisazo dye is preferable.

  The azo dye of the present invention represented by the general formula (1) is a case where the free acid form is represented by any one of the general formulas (1), (1-a), and (1-b). However, in the form of free acid, the molecular weight is usually 500 or more, preferably 550 or more, and usually 5000 or less, preferably 4000 or less, more preferably 3500 or less. When the molecular weight exceeds the above upper limit, there is a risk that the color developability is lowered, and when the molecular weight is below the lower limit, the absorption spectrum peak may have a short wavelength (color tone becomes shallow).

  Specific examples of the azo dye of the present invention represented by the general formula (1) include dyes having the structures shown in the following (I-1) to (I-31) in the form of a free acid. It is not limited to this.

  The azo dye represented by the general formula (1) can be produced according to a method known per se. For example, the dye represented by (I-1) can be produced by the following steps (A) to (E).

(A) 4-aminobenzene sulfonic acid (sulfanilic acid) and 2-methoxy-5-methylaniline [for example, Yutaka Hosoda "New dye chemistry" (published by Gihodo on December 21, 1973) See page 396, page 409] to produce a monoazo compound through a diazotization and coupling step.
(B) The obtained monoazo compound is similarly diazotized by a conventional method, and a coupling reaction reaction with 2-methoxy-5-methylaniline is performed to produce a disazo compound.
(C) 6-Amino-1-naphthol-3-sulfonic acid (J acid) is dissolved in water at pH 6 and cooled to 0-5 ° C. Cyanuric chloride is added to this, and the reaction is completed for 2 hours while maintaining the temperature at 0 to 5 ° C. to complete the reaction. Subsequently, 3-aminobenzenesulfonic acid (methanilic acid) aqueous solution is added at room temperature, and a condensation reaction is performed at pH 6-7 for several hours.
(D) Water and N-methyl-2-pyrrolidone are added to the disazo compound obtained in step (B), dissolved in 25 wt% aqueous sodium hydroxide solution at pH 9 and cooled to 0-5 ° C., etc. Diazotize by a conventional method. A trisazo compound is produced by performing a coupling reaction with this and the condensation reaction product obtained in the step (C). After completion of the reaction, 3-amino-1,2-propanediol is added, the temperature is raised to 60 ° C., and a 25 wt% aqueous sodium hydroxide solution is added to make it strongly alkaline (pH of about 9 to 9.5). To complete the reaction.
(E) After cooling, the desired dye No. (I-1) is obtained.

（式中、Ｄ^１およびＥ^１は、置換基を有していても良いフェニレン基、または置換基を有していても良いナフチレン基を表し、
Ｇ^１はカルボキシ基、スルホ基、またはリン酸基を表し、
Ｑ^１はハロゲン原子、水酸基、ニトロ基、置換基を有していても良いアミノ基、置換基を有していても良い炭素数１〜４のアルキル基、置換基を有していても良い炭素数１〜３のアルコキシ基、カルボキシル基、或いはスルホ基を表し、
Ｑ^２およびＱ^３はそれぞれ独立に、水素原子、置換基を有していても良い炭素数１〜４のアルキル基、或いは置換基を有していても良いフェニル基を表し、
ｐは０または１を表し、ｔは１または２を表す。） In particular, the anisotropic dye film of the present invention contains an azo dye for an anisotropic dye film formed by a wet film forming method in which the form of the free acid is represented by the following general formula (2). It is preferable.

(In the formula, D ¹ and E ¹ represent a phenylene group which may have a substituent, or a naphthylene group which may have a substituent,
G ¹ represents a carboxy group, a sulfo group, or a phosphate group,
Q ¹ may have a halogen atom, a hydroxyl group, a nitro group, an amino group which may have a substituent, an alkyl group having 1 to 4 carbon atoms which may have a substituent, or a substituent. Represents an alkoxy group having 1 to 3 carbon atoms, a carboxyl group, or a sulfo group;
Q ² and Q ³ each independently represent a hydrogen atom, an optionally substituted alkyl group having 1 to 4 carbon atoms, or an optionally substituted phenyl group,
p represents 0 or 1, and t represents 1 or 2. )

Here, the trisazo dye represented by the general formula (2) will be described.
The trisazo dye is a water-soluble black dichroic dye. The trisazo dye has a molecular structure in which substituents giving strong attractive force to other molecules are arranged at specific positions on both ends of the molecular long axis, and D ¹ and E ¹ have hydrophobicity, so that each molecule is hydrophobic. Interaction (hydrophobic interaction), making it easy for molecules to form an associated state.

That is, it is considered that (i) each dye molecule has a substituent that gives a strong attractive force to other molecules at both ends of the molecular long axis, so that it is easy to attract each other and form an associated state. Furthermore, (ii) since each molecule has hydrophobicity in D ¹ and E ¹ , it is considered that the hydrophobic portions in the aqueous solution attract each other, making it easy to form an association state. In addition, (iii) there are substituents that give strong attractive force to other molecules at both ends of the molecular long axis (phenyl group having a substituent at the 3-position and naphthyl group having an amino group at the 7-position). In the case of a salt, the 3-position substituent and the 7-position amino group are close to each other because of their positional relationship, and it is considered that a stable association state can be easily formed by attracting strongly.
It is considered that the azo dye represented by the general formula (2) forms a high lyotropic liquid crystal state due to the three-point configuration (i) to (iii) in which an association state can be easily formed.

  In addition, the azo dye represented by the general formula (2) is not only black, but also the composition containing the dye and the dye is a process unique to the wet film forming method, that is, on the surface of the substrate. A high-order molecular orientation state can also be shown through a lamination process such as coating. That is, it means that it is possible to form an achromatic dye film having high anisotropy.

  Until now, when trying to obtain an achromatic anisotropic dye film using one kind of dichroic dye, the molecular orientation tends to be disturbed by the steric repulsion of the substituent introduced into the dye molecule, resulting in high dichroism. It was difficult to get. Therefore, the anisotropic dye film by the conventional wet film-forming method often obtained an achromatic anisotropic dye film by combining a plurality of kinds of dyes. However, since the azo dye represented by the general formula (2) has a specific dye structure as described above, it can form a high lyotropic liquid crystal state, exhibit a higher-order molecular orientation state, and 1 It is possible to show black color even with different types of pigments. Therefore, the composition containing the azo dye represented by the general formula (2) can provide an anisotropic dye film exhibiting high dichroism.

In the general formula (2), D ¹ and E ¹ represent a phenylene group which may have a substituent or a naphthylene group which may have a substituent. As the phenylene group, a 1,4-phenylene group is preferable, and as the naphthylene group, a 1,4-naphthylene group is preferable in order to exhibit a hydrophobic interaction. As the substituent of this phenylene group, an optionally substituted alkyl group having 1 to 4 carbon atoms (for example, methyl group, ethyl group, n-propyl group, n-butyl group, etc.), substituent group An alkoxy group having 1 to 4 carbon atoms (for example, a methoxy group, an ethoxy group, an n-propoxy group, an n-butoxy group, etc.) and a substituent group that may have a carbon number of 2 A group having a small polarity such as an acylamino group of ˜7 (for example, acetylamino group, benzoylamino group, etc.) is preferable from the viewpoint of improving associative property due to hydrophobic interaction in forming a lyotropic liquid crystal.

  As a substituent of the naphthylene group, a group having a small polarity such as an alkoxy group having 1 to 4 carbon atoms (for example, methoxy group, ethoxy group, etc.) which may have a substituent may form a lyotropic liquid crystal. From the viewpoint of improving the association property due to the hydrophobic interaction. Examples of the substituent that the alkyl group, alkoxy group, and acylamino group may have include a hydroxy group, an alkyl group, and an alkoxy group.

G ¹ is preferably a sulfo group, a carboxy group, or a phosphoric acid group as a substituent that gives strong attraction as described above, and particularly preferably a sulfo group from the viewpoint of giving attraction in a wide pH range.

Q ¹ is a halogen atom, a hydroxyl group, a nitro group, an amino group which may have a substituent (preferably an acylamino group such as an acetylamino group or a benzoylamino group), an optionally substituted carbon, Represents an alkyl group having 1 to 4 alkyl groups (for example, a methyl group, an ethyl group, etc.), an alkoxy group having 1 to 3 carbon atoms, a carboxyl group and a sulfo group which may have a substituent, particularly preferably a hydrogen atom. , Hydroxyl group, carboxyl group, and sulfo group. Examples of the substituent that the alkyl group and alkoxy group may have include a hydroxy group, an alkyl group, and an alkoxy group.

Q ² and Q ³ may each independently have a hydrogen atom, a substituent, an alkyl group having 1 to 4 carbon atoms (for example, a methyl group, an ethyl group, etc.), or a substituent. It is a good phenyl group, and particularly preferred is that either Q ² or Q ³ is a hydrogen atom. Examples of the substituent that the alkyl group and the phenyl group may have include a hydroxy group, a carboxy group, and a sulfo group.

  p represents 0 or 1, and t represents a number of 1 or 2.

In the dye structure, the azo dye represented by the general formula (2) has a substituent on both ends of the molecular long axis and a substitution position (a phenyl group having a substituent at the 3-position and a naphthyl group having an amino group at the 7-position). By specifying D ¹ and E ¹ having a hydrophobic interaction, the associative property is improved as described above, and a high lyotropic liquid crystal state can be formed. Accordingly, the azo dye represented by the general formula (2) is suitable as a dye for an anisotropic dye film formed by a wet film forming method, and has a high dichroic ratio. Therefore, if a dye composition using the dye is used for an anisotropic dye film, an anisotropic dye film having high dichroism can be obtained.

  The azo dye represented by the general formula (2) exhibits a black color, and among them, a dye having an excitation purity of 0% to 12% is preferable. That is, when a dye having a stimulus purity of 0% to 12% is used, there is no disorder of molecular orientation caused by mixing different molecules, and high dichroism can be exhibited.

  Here, the stimulus purity refers to the wavelength corresponding to the intersection with the extended spectral locus as a principal wavelength by connecting the chromaticity coordinate N of the standard light and the chromaticity coordinate C of the obtained pigment from a chromaticity diagram. Calculate from the ratio of each point. The chromaticity coordinates C are obtained by adding a dye to water to obtain an aqueous dye solution, measuring the visible light transmittance of this aqueous solution with a spectrophotometer, and calculating the chromaticity xy under the CIE1964 XYZ color system, D65 standard light source. be able to.

  The stimulating purity of the pigment referred to in the present invention means that measured and calculated as a pigment aqueous solution by adding the pigment to water.

  In addition, as a calculation method thereof, a publicly known publication described in “New Color Science Handbook” edited by the Japan Color Society, published by the University of Tokyo Press, November 25, 1989 (2nd revision), pages 104 to 105, etc. It can be determined by a method.

  The azo dye represented by the general formula (2) is preferably a dye having a stimulus purity of 0% to 12%, but the stimulus purity is 0% or more, more preferably 9% or less, most preferably 6% or less. It is.

  The molecular weight of the dye represented by the general formula (2) is usually 595 or more, usually 1500 or less, preferably 1200 or less in the form of a free acid.

  Specific examples of the dye represented by the general formula (2) include dyes having structures shown in (II-1) to (II-15), but are not limited thereto.

  The azo dye represented by the general formula (2) can be produced according to a method known per se. For example, the coloring matter represented by (II-1) can be produced by the following steps (a) to (c).

(A) From 3-aminobenzenesulfonic acid (methanilic acid) and 2-methoxyaniline (o-anisidine), using a conventional method (for example, “New dye chemistry” written by Yutaka Hosoda (published by Gihodo on December 21, 1973)) According to page 396, page 409), a monoazo compound is produced through a diazotization and coupling step.
(B) The obtained disazo compound is similarly diazotized by a conventional method, and a coupling reaction with 3-methylaniline (m-toluidine) is performed to produce a disazo compound.
(C) Similarly, the resulting disazo compound is diazotized by a conventional method, subjected to a coupling reaction with 7-amino-1-naphthol-3,6-disulfonic acid (RR acid), and salted out with sodium chloride. The target dye No. (II-1) is obtained.
In particular, since the dye represented by the structural formula (II-1) forms a lyotropic liquid crystal in an aqueous solution, an anisotropic dye film exhibiting high dichroism can be produced. Suitable and useful dyes.

  The anisotropic dye film of the present invention contains the dyes shown in (I-1), (I-31), (II-3) and (II-15) among the above-mentioned exemplified dyes. It is preferable.

  Among the dyes used in the present invention, the dye having an acidic group may be used in its free acid form, or a part of the acidic group may be in a salt form. Further, a salt type dye and a free acid type dye may be mixed. Moreover, 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) A strong acid such as hydrochloric acid is added to an aqueous solution of a dye obtained in a salt form, and the dye is acidified in the form of a free acid, and then an alkaline solution having a desired counter ion (for example, lithium hydroxide or sodium hydroxide). ) To neutralize the acidic group of the dye and perform salt exchange.
2) A method of performing salt exchange in the form of a salting-out cake by adding a large excess of a neutral salt (for example, lithium chloride or sodium chloride) having a desired counter ion to an aqueous solution of a dye obtained in a salt form. .
3) An aqueous solution of a dye obtained in a salt form is treated with a strongly acidic ion exchange resin, and the dye is acidified in the form of a free acid, and then an alkaline solution having a desired counter ion (for example, lithium hydroxide or water). A method in which the acidic group of the dye is neutralized with sodium oxide and the salt is exchanged.
4) A method of performing salt exchange by causing an aqueous solution of a dye obtained in a salt form to act on a strongly acidic ion exchange resin that has been previously treated with an alkaline solution (eg, lithium hydroxide or sodium hydroxide) having a desired counter ion.

  Whether the acidic group takes the free acid form or the salt form depends on the pKa of the dye and the pH of the aqueous dye solution.

  Examples of the above salt types include salts of alkali metals such as Na, Li and K, ammonium salts optionally substituted with an alkyl group having 1 to 16 carbon atoms or a hydroxyalkyl group having 1 to 12 carbon atoms, Or the salt of an organic amine is mentioned. Examples of the organic amine include a lower alkylamine having 1 to 6 carbon atoms, a lower alkylamine having 1 to 6 carbon atoms substituted with a hydroxy group, and a lower alkylamine having 1 to 6 carbon atoms substituted with a carboxy group. It is done. In the case of these salt types, the type is not limited to one type, and a plurality of types may be mixed.

In the present invention, the above-described dyes can be used alone, but two or more of these may be used in combination, and dyes other than the above exemplified dyes are blended and used to such an extent that the orientation is not lowered. Thus, anisotropic dye films having various hues can be produced. In particular, when used as a polarizing film, a film having a deep color tone is preferable, and a neutral color (neutral black in the visible wavelength region of 380 to 780 nm as a hue (for example, in the L ^* a ^* b ^* color system, √ {( a ^* ) ² + (b ^* ) ² } ≦ 5.) is preferred as a display element, particularly a color display element polarizer.

Examples of blending dyes when blending other dyes include C.I. I. Direct Yellow 12, C.I. I. Direct Yellow 34, C.I. I. Direct Yellow 86, C.I. I. Direct Yellow 142, C.I. I. Direct
Yellow 132, C.I. I. Acid Yellow 25, C.I. I. Direct Orange 39, C.I. I. Direct Orange 72, C.I. I. Direct Orange 79, C.I. I. Acid Orange 28, C.I. I. Direct Red 39, C.I. I. Direct Red 79, C.I. I. Direct
Red 81, C.I. I. Direct Red 83, C.I. I. Direct Red 89, C.I. I. Acid Red 37, C.I. I. Direct Violet 9, C.I. I. Direct Violet 35, C.I. I. Direct Violet 48, C.I. I. Direct Violet 57, C.I. I. Direct Blue 1, C.I. I. Direct Blue 67, C.I. I. Direct Blue 83, C.I. I. Direct Blue 90, C.I. I. Direct Green 42, C.I. I. Direct Green 51, C.I. I. Direct Green 59 etc. are mentioned.

  The anisotropic dye film of the present invention is preferably produced by a dry film forming method or a wet film forming method described later using a dye composition for an anisotropic dye film containing at least a dye. In the dye composition for an anisotropic dye film of the present invention, the above-mentioned dyes can be used alone, but can be used by mixing them with other dyes to the extent that they do not deteriorate the orientation. Thereby, anisotropic dye films having various hues can be produced.

  The dye composition for an anisotropic dye film of the present invention usually contains a solvent, and usually the dye is dissolved or dispersed in the solvent. As the dye contained in the anisotropic dye film dye composition, the dyes represented by the general formulas (1) and (2) are preferable from the viewpoint of solubility in a solvent. Moreover, additives, such as surfactant and a pH adjuster, may be mix | blended in the composition. These additives are also usually used by dissolving in a solvent.

  As the solvent, water, a water-miscible organic solvent, or a mixture thereof is suitable. Specific examples of the organic solvent include alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol and glycerin, glycols such as ethylene glycol and diethylene glycol, cellosolves such as methyl cellosolve and ethyl cellosolve, or a mixture of two or more. A solvent is mentioned.

  When the dye composition for the anisotropic dye film is a solution containing such a solvent, the concentration of the dye in the dye composition for the anisotropic dye film may be a film formation method, dye solubility, or lyotropic liquid crystal. Depending on the formation concentration of the supramolecular structure such as the state, it is usually 0.01% by weight or more, preferably 0.1% by weight or more, more preferably 0.5% by weight or more, usually 50% by weight or less, preferably Is 30% by weight or less, more preferably 25% by weight or less, particularly preferably 20% by weight or less, and most preferably 15% by weight or less. If the dye concentration is too low, sufficient dichroism cannot be obtained in the obtained anisotropic dye film, and if it is too high, the dye may be precipitated.

  In order to improve the wettability to the base material and the coating property, an additive such as a surfactant can be added to the anisotropic dye film dye composition. As the surfactant, any of anionic, cationic and nonionic can be used. The concentration of addition is sufficient to obtain the desired effect, and is an amount that does not inhibit the orientation of the dye molecules, and is usually 0.05% by weight or more as the concentration in the dye composition for the anisotropic dye film. % By weight or less is preferable, and 0.5% by weight or less is more preferable.

  In addition, for the purpose of suppressing instability such as salt formation and aggregation of the dye in the dye composition for anisotropic dye film, a commonly known pH adjuster such as acid and alkali is anisotropically used. The pH may be adjusted by adding either before or after the mixing of the components of the dye composition for the photosensitive dye film or during the mixing. The pH of the dye composition is preferably adjusted to 3 or more, more preferably 4 or more, preferably 13 or less, and more preferably 12 or less from the viewpoint of solution stability and ease of handling in production. preferable.

  Furthermore, as additives other than those described above, known additives described in “Additive for Coating”, Edited by J. Bieleman, Willey-VCH (2000) can also be used.

  The anisotropic dye film of the present invention is preferably produced by a dry film forming method or a wet film forming method described later using a dye composition for an anisotropic dye film containing at least a dye. The anisotropic dye film increases the molecular alignment in the anisotropic dye film and obtains high dichroism by utilizing the intermolecular interaction between the dye molecules. An anisotropic dye film formed by a wet film forming method is preferable to a dry film forming method such as performing.

  The azo dye represented by the general formula (1), particularly a dye that forms a lyotropic liquid crystal in an aqueous solution as shown by the structural formula (I-1), exhibits high dichroism by a wet film formation method. The polarizing film (anisotropic dye film) shown can be produced and is useful. Many of the azo dyes of the present invention in which the form of the free acid is represented by the general formula (1) exhibits high dichroism and forms a lyotropic liquid crystal in an aqueous solution. Since many of them have high affinity, it is suitable for such a film forming method.

  Further, since the trisazo dye represented by the general formula (2) has a specific dye structure, it can form a high lyotropic liquid crystal state, exhibit a higher-order molecular orientation state, and even one kind of dye is black. Can exhibit high dichroism.

  The wet film-forming method can also form an anisotropic dye film on a high heat-resistant substrate such as glass, and can obtain a high heat-resistant polarizing element. The point which can be used for the use as which high heat resistance is calculated | required, such as a display panel, is preferable.

  Among the methods for forming an anisotropic dye film, a dry film forming method includes forming a polymer polymer into a film and then dyeing with a dye composition for anisotropic dye film, or polymer weight A method of stretching an unstretched film obtained by adding a dye composition for an anisotropic dye film to a combined solution and forming a film after dyeing the undiluted solution, or for an anisotropic dye film by heating under vacuum conditions Examples thereof include a method of evaporating the dye composition and vacuum depositing it on various substrates such as glass. In addition, as a constituent material of the film dye | stained with the pigment | dye composition for anisotropic pigment | dye films here, polymeric materials with high affinity with pigment | dye, such as polyvinyl alcohol, are mentioned.

  As a wet film-forming method, a method of obtaining the dye composition for anisotropic dye film as described above as a coating liquid, applying it to various substrates such as a glass plate, drying, orienting and laminating the dye, etc. A well-known method is mentioned.

  For example, Yuji Harasaki's “Coating Engineering” (Asakura Shoten Co., Ltd., published on March 20, 1971) pp. 253-277 and “Creation and Application of Molecular Coordinating Materials” supervised by Kunihiro Ichimura (CMC Publishing, 1998) (Published on Mar. 3, 1980) Known methods described on pages 118 to 149, etc., and spin coating method, spray coating method, bar coating method, roll coating method, blade coating on a substrate subjected to orientation treatment in advance The method of apply | coating by the method etc. is mentioned.

  The temperature at the time of application | coating on the base material of the pigment | dye composition for anisotropic pigment | dye films is 0 degreeC or more and 80 degrees C or less normally, Preferably it is 40 degrees C or less. The humidity is usually 10% RH or more, preferably 30% RH or more, and usually 80 RH% or less.

  In the wet film forming method, a dye film is formed through a coating process of a dye composition for an anisotropic dye film on a substrate and a drying process. The operating conditions of these processes are based on self-organization of the dye. It is preferable to control so as to obtain the anisotropic dye film of the present invention that maintains a high-order molecular alignment state formed on the basis of high lyotropic liquid crystallinity and satisfies the above-described molecular stacking period and molecular stacking length.

  For this reason, a rapid temperature rise is not preferable even in the drying step, and it is generally preferable to perform natural drying. However, if preferable conditions are given, the temperature during drying is usually 0 ° C. or higher, preferably 10 ° C. As mentioned above, it is 120 degrees C or less normally, Preferably it is 110 degrees C or less. The humidity is usually 10% RH or more, preferably 30% RH or more, and usually 80% RH or less.

  Examples of the substrate include glass, triacetate, acrylic, polyester, triacetyl cellulose, or a urethane resin film. Further, in order to control the orientation direction of the dichroic dye, the surface of the substrate is publicly known as described in “Liquid Crystal Handbook” (Maruzen Co., Ltd., issued on October 30, 2000), pages 226 to 239. An orientation treatment layer, a fluororesin layer, or the like may be provided by the above method. Furthermore, modification of the surface energy state and the like may be performed by combined use of light irradiation, corona treatment, plasma treatment and the like.

  The anisotropic dye film of the present invention is preferably used with a protective layer provided on the surface. This protective layer is formed by lamination with a transparent polymer film such as triacetate, acrylic, polyester, polyimide, triacetylcellulose, or urethane film, and is put to practical use.

  Such an anisotropic dye film of the present invention exhibits a high dichroic ratio, but the dichroic ratio is preferably 9 or more, more preferably 12 or more, and particularly preferably 15 or more.

  Further, the film thickness of the anisotropic dye film formed on the substrate by the wet film forming method is usually the film thickness after drying, preferably 50 nm or more, more preferably 100 nm or more, preferably 50 μm or less, The thickness is preferably 10 μm or less, particularly preferably 1 μm or less.

  In addition, when the anisotropic dye film of the present invention is used as a polarizing filter or the like for various display elements such as LCDs and OLEDs, the anisotropic dye film is directly applied to an electrode substrate constituting these display elements. A base material on which the anisotropic dye film is formed may be used as a constituent member of these display elements.

  The anisotropic dye film of the present invention functions as a polarizing film that obtains linearly polarized light, circularly polarized light, elliptically polarized light, etc. by utilizing the anisotropy of light absorption, and also includes a film forming process and a composition containing a substrate and a dye Thus, it is possible to make it functional as various anisotropic films such as refraction anisotropy and conduction anisotropy, and it is possible to obtain various kinds of polarizing elements that can be used for various purposes.

  The polarizing element of the present invention uses such an anisotropic dye film of the present invention. When the anisotropic dye film of the present invention is formed on a substrate, the polarizing element of the present invention is formed. The formed anisotropic dye film itself may be used, and in addition to the protective layer as described above, layers having various functions such as an adhesive layer and an antireflection layer are laminated to be used as a laminate. May be. The stacking order at that time can be appropriately selected depending on the application.

  EXAMPLES Next, although an Example demonstrates this invention further more concretely, this invention is not limited to a following example, unless the summary is exceeded.

  In the following, the molecular stacking period, the stacking length, and the degree of orientation of the molecular stacking axis are determined by in-plane measurement using an X-ray diffractometer for thin film evaluation (“RINT2000PC” in-plane optical system manufactured by Rigaku Corporation). The diffraction profile and the rocking profile obtained by the in-plane rocking scan measurement were obtained by analyzing the above-described method. Both measurements were performed with CuKα at an incident angle of 1 °.

In addition, the dichroic ratio (D) is measured after measuring the transmittance of the anisotropic dye film with a spectrophotometer (“instant multi-photometry system MCPD2000” manufactured by Otsuka Electronics Co., Ltd.) in which an iodine polarizing element is arranged in the incident optical system. The following formula was used for calculation.
Dichroic ratio (D) = Az / Ay
Az = -log (Tz)
Ay = -log (Ty)
Tz: transmittance for polarized light in the absorption axis direction of the dye film
Ty: transmittance for polarized light in the direction of the polarization axis of the dye film

  Further, the chromaticity xy (CIE1964 XYZ color system, under D65 standard light source) of the anisotropic dye film was calculated by introducing Tz and Ty into the method of JIS-Z-8701-1995.

In addition, after measuring the transmittance of the dye film with a spectrophotometer, the degree of polarization is determined according to JIS-Z-8701-1995, and the tristimulus values X, Y, and Z of the transmitted object color in the 2-degree field of view are obtained. Calculated by The standard light spectral distribution used for calculating the tristimulus values X, Y, and Z was a D65 light source.
Polarization degree (ρ) = {(Y2−Y1) / (Y2 + Y1)} ^1/2 × 100
Y2: Tristimulus value Y when two polarization axes of the dye film are stacked in parallel
Y1: Tristimulus value Y when two polarization axes of the dye film are stacked perpendicularly

  In the following, “part” means “part by weight”.

[1] Lamination cycle and lamination length (Examples 1 to 6, Comparative Example 1)
Example 1
Exemplified dye No. shown below in 89.8 parts of water. 10 parts of (I-31) and 0.2 part of a nonionic surfactant Emulgen 109P (manufactured by Kao Corporation) were stirred and dissolved to obtain a dye composition for anisotropic dye film.

  On the other hand, a substrate (polyimide film thickness of about 800 mm) on which a polyimide alignment film is formed by a silk printing method on a glass substrate (75 mm × 25 mm, thickness 1 mm) is prepared by rubbing with a cloth in advance. An anisotropic dye having a film thickness of about 0.4 μm is formed by coating the dye composition for anisotropic dye film on this with a bar coater (using “No. 3” manufactured by Tester Sangyo Co., Ltd.), followed by natural drying. A membrane was obtained.

The X-ray diffraction profile of the obtained anisotropic dye film is shown in FIG. 4, and the in-plane rocking profile is shown in FIG. FIG. 4 shows the in-plane measurement results of the anisotropic dye film observed from two directions in which the diffraction plane perpendicular to the polarization axis and the diffraction plane perpendicular to the absorption axis are observed, and the solid line represents the polarization axis. A dotted line is an X-ray diffraction profile obtained from a direction in which a diffraction plane perpendicular to the absorption axis is observed. FIG. 5 shows the in-plane rocking curve measurement result of the diffraction peak derived from the molecular lamination of this anisotropic dye film.
Table 1 shows the obtained molecular stacking cycle, stacking length, orientation degree of molecular stacking axis, and dichroic ratio.

  From these results, it was confirmed that the anisotropic dye film of this example had a molecular arrangement suitable for dichroic ratio expression and exhibited a high dichroic ratio.

(Example 2)
Example dye No. shown below in 90 parts of water. 10 parts of (II-15) was stirred and dissolved to obtain a dye composition for anisotropic dye film.

  Except that a bar coater ("No. 2" manufactured by Tester Sangyo Co., Ltd.) was used, this anisotropic dye film dye composition was applied to a glass substrate on which a polyimide alignment film was formed in the same manner as in Example 1. The film was naturally dried to obtain an anisotropic dye film.

The molecular lamination period, the lamination length, the orientation degree of the molecular lamination axis and the dichroic ratio of the obtained anisotropic dye film were examined, and the results are shown in Table 1.
From Table 1, it was confirmed that the anisotropic dye film of this example had a molecular arrangement suitable for dichroic ratio expression and exhibited a high dichroic ratio.

(Example 3)
Illustrative dye No. shown below in 92 parts of water. (I-1) Eight parts were stirred and dissolved to obtain a dye composition for anisotropic dye film.

  Except that an applicator with a gap of 10 μm (manufactured by Imoto Seisakusho Co., Ltd.) was used, this dye composition for anisotropic dye film was applied to a glass substrate on which a polyimide alignment film was formed in the same manner as in Example 1. An anisotropic dye film was obtained by drying.

The molecular lamination period, the lamination length, the orientation degree of the molecular lamination axis and the dichroic ratio of the obtained anisotropic dye film were examined, and the results are shown in Table 1.
From Table 1, it was confirmed that the anisotropic dye film of this example had a molecular arrangement suitable for dichroic ratio expression and exhibited a high dichroic ratio.

Example 4
In 80 parts of water, the exemplified dye No. After stirring and dissolving 12 parts of (I-31), 8 parts of glycerin was added to obtain a dye composition for anisotropic dye film.

  Except that an applicator with a gap of 10 μm (manufactured by Imoto Seisakusho Co., Ltd.) was used, this dye composition for anisotropic dye film was applied to a glass substrate on which a polyimide alignment film was formed in the same manner as in Example 1. An anisotropic dye film was obtained by drying.

The molecular lamination period, the lamination length, the orientation degree of the molecular lamination axis and the dichroic ratio of the obtained anisotropic dye film were examined, and the results are shown in Table 1.
From Table 1, it was confirmed that the anisotropic dye film of this example had a molecular arrangement suitable for dichroic ratio expression and exhibited a high dichroic ratio.

(Example 5)
The exemplified dye No. shown below in 76 parts of water. (II-3) After stirring and dissolving 15 parts, 9 parts of glycerin was added to obtain a dye composition for anisotropic dye film.

  Except that a bar coater ("No. 2" manufactured by Tester Sangyo Co., Ltd.) was used, this anisotropic dye film dye composition was applied to a glass substrate on which a polyimide alignment film was formed in the same manner as in Example 1. The film was naturally dried to obtain an anisotropic dye film.

The molecular lamination period, the lamination length, the orientation degree of the molecular lamination axis and the dichroic ratio of the obtained anisotropic dye film were examined, and the results are shown in Table 1.
From Table 1, it was confirmed that the anisotropic dye film of this example had a molecular arrangement suitable for dichroic ratio expression and exhibited a high dichroic ratio.

(Example 6)
In 85 parts of water, the exemplified dye No. (II-3) 15 parts of the mixture was stirred and dissolved to obtain a dye composition for anisotropic dye film.

  Except that a bar coater ("No. 2" manufactured by Tester Sangyo Co., Ltd.) was used, this anisotropic dye film dye composition was applied to a glass substrate on which a polyimide alignment film was formed in the same manner as in Example 1. The film was naturally dried to obtain an anisotropic dye film.

The molecular lamination period, the lamination length, the orientation degree of the molecular lamination axis and the dichroic ratio of the obtained anisotropic dye film were examined, and the results are shown in Table 1.
From Table 1, it was confirmed that the anisotropic dye film of this example had a molecular arrangement suitable for dichroic ratio expression and exhibited a high dichroic ratio.

(Comparative Example 1)
6 parts of a dye having the following structural formula was added to 94 parts of water, and after stirring and dissolving, the mixture was filtered to obtain a dye composition for an anisotropic dye film.

  After applying the pigment composition for anisotropic dye to a slide glass (“Slide Glass White Edge Polish Frost No. 1” manufactured by Matsunami Glass Industry Co., Ltd.) with a bar coater (“No. 2” manufactured by Coating Tester Industry Co., Ltd.) By anisotropic drying, an anisotropic dye film was obtained.

The molecular lamination period, the lamination length, the orientation degree of the molecular lamination axis and the dichroic ratio of the obtained anisotropic dye film were examined, and the results are shown in Table 1.
From Table 1, it is presumed that the anisotropic dye film of this comparative example has a low dichroic ratio because the lamination length is less than 105 mm and the number of arrangement molecules suitable for dichroic ratio expression is not sufficient.

[2] Synthesis of azo dye represented by general formula (2) (Synthesis Example 1)
(Synthesis Example 1)
According to the following methods (A) to (E), the following dye No. A dye of (I-31) was synthesized.

(A) 4-aminobenzene sulfonic acid (sulfanilic acid) and 2-methoxy-5-methylaniline [for example, Yutaka Hosoda "New dye chemistry" (published by Gihodo on December 21, 1973) See page 396, page 409], a monoazo compound was produced through a diazotization and coupling step.
(B) Similarly, the monoazo compound obtained in step (A) was diazotized by a conventional method, and a coupling reaction with 2-methoxy-5-methylaniline was performed to produce a disazo compound.
(C) Separately, 6-amino-1-naphthol-3-sulfonic acid (J acid) was dissolved in water at pH 6 and cooled to 0-5 ° C. Cyanuric chloride was added to this, and the reaction was carried out for 2 hours while maintaining the temperature at 0 to 5 ° C. to complete the reaction. Subsequently, 3-aminobenzenesulfonic acid (methanilic acid) aqueous solution was added at room temperature, and the condensation reaction was performed at pH 6-7 for several hours.
(D) The disazo compound obtained in step (B) was similarly diazotized by a conventional method, and the compound obtained in step (C) was subjected to a coupling reaction to produce a trisazo compound. After completion of the reaction, 3-amino-1,2-propanediol was added, the temperature was raised to 60 ° C., a 25 wt% aqueous sodium hydroxide solution was added to adjust the pH to 9 to 9.5, and the reaction was completed.
(E) After cooling, the desired dye No. (I-31) was obtained.

[3] Preparation of anisotropic dye film (Examples 7 to 17, Comparative Examples 2 to 7)
(Example 7)
In 100 parts of water, no. 10 parts of the dye (I-1) and 0.2 part of nonionic surfactant Emulgen 109P (manufactured by Kao Corporation) were added, neutralized to 8.0 with a 5% by weight aqueous lithium hydroxide solution, and dissolved by stirring. And then filtered to obtain an aqueous dye solution (an anisotropic dye film-forming composition). When this aqueous dye solution was dropped on a slide glass and the drying and concentration process was observed under a polarizing microscope, the initial solution was an isotropic solution, but it was confirmed that a lyotropic liquid crystal state was obtained by drying and concentration.

  On the other hand, a substrate on which a polyimide alignment film is formed by a silk printing method on a glass substrate (polyimide film thickness of about 800 mm) is prepared in advance by rubbing with a cloth. After coating with a coater (No. 3 manufactured by Tester Sangyo Co., Ltd.), an anisotropic dye film was obtained by drying at room temperature.

  FIG. 6 shows the transmittance characteristics of the dye film in the absorption axis direction and the polarization axis direction. The resulting anisotropic dye film had a maximum absorption wavelength (λmax) of 555 nm and a dichroic ratio of 12.

(Example 8)
In 100 parts of water, the No. After adding 5 parts of the dye of (I-1), the pH was neutralized to 8.0 with a 5 wt% aqueous lithium hydroxide solution, dissolved by stirring, and then filtered to obtain an aqueous dye solution. Further, 4 parts of boric acid was added to 96 parts of this aqueous dye solution to obtain a dyeing solution.

Separately, 10 parts of polyvinyl alcohol having an average degree of polymerization of 1750 was added to 90 parts of water, and after stirring and dissolving in a water bath, the film was developed to a thickness of 1 mm and dried to obtain a polyvinyl alcohol (PVA) film.
This PVA film was immersed in the dyeing solution and then stretched 3 times to obtain an anisotropic dye film. The tristimulus values of this dye film are as shown in Table 2, and the degree of polarization was 79.9%.

Example 9
In 100 parts of water, the No. Add 5 parts of the dye of (I-1) and 0.2 part of nonionic surfactant Emulgen 109P (manufactured by Kao Corporation), neutralize the pH to 8.0 with a 5 wt% aqueous lithium hydroxide solution, and dissolve with stirring. And then filtered to obtain an aqueous dye solution.

  This aqueous dye solution was applied to a glass substrate prepared by the same method as in Example 7 using a spin coater, and then dried at room temperature to obtain an anisotropic dye film. The obtained dye film had a dichroic ratio of 20.

(Example 10)
In 100 parts of water, No. shown below. 25 parts of the pigment of (I-25) and 0.2 part of nonionic surfactant Emulgen 109P (manufactured by Kao Corporation) were added and neutralized to pH 8.0 with a 5% by weight aqueous lithium hydroxide solution. And then filtered to obtain an aqueous dye solution. When this aqueous dye solution was observed under a polarizing microscope in the same manner as in Example 7, it was confirmed to be in a lyotropic liquid crystal state.

Furthermore, this dye aqueous solution was applied to a glass substrate prepared by the same method as in Example 7 by a blade coating method, and then dried at room temperature to obtain an anisotropic dye film.
FIG. 7 shows the transmittance characteristics in the absorption axis direction and the polarization axis direction of this dye film. The obtained dye film had a maximum absorption wavelength (λmax) of 570 nm and a dichroic ratio of 15.

(Example 11)
In Example 8, the dye used was the same as No. 1 above. Except having changed to the pigment | dye of (I-25), the pigment | dye aqueous solution was prepared by the same method, the PVA film was dye | stained, and the pigment | dye film | membrane was obtained.
The tristimulus values of the obtained dye film are as shown in Table 2, and the degree of polarization was 64%.

(Example 12)
In 95 parts of water, the following dye No. Add 5 parts of the sodium salt of (II-1) and 0.2 part of nonionic surfactant Emulgen 109P (manufactured by Kao Corporation), dissolve with stirring, filter, and filter aqueous solution (dye for anisotropic dye film) Composition) was obtained.

  On the other hand, a glass substrate (75 mm × 25 mm, 1.1 mm thickness, polyimide film thickness of about 800 mm) is previously rubbed with a cloth on a glass substrate having a polyimide alignment film formed on a glass substrate as a base material by spin coating. The above dye aqueous solution is applied to this with a spin coater (SC-200 manufactured by Oshikelle Co., Ltd.) (1000 rpm for 5 seconds, 2500 rpm for 15 seconds), and then naturally dried to give the dye in the rubbing direction. An anisotropic dye film with an orientation of was obtained.

In the obtained anisotropic dye film, the chromaticity xy (CIE1964 XYZ color system, under the D65 standard light source) of the transmitted light (Tz) with respect to the polarized light having the vibration plane in the absorption axis direction in the dye film surface and the dye film surface Chromaticity xy (CIE1964 XYZ color system, under D65 standard light source), maximum absorption wavelength (λ _max ) and dichroic ratio (D) of transmitted light (Ty) with respect to polarized light having a vibration plane in the polarization axis direction 3 shows.
The obtained anisotropic dye film had a high dichroic ratio (light absorption anisotropy) capable of functioning sufficiently as a polarizing film.

(Example 13)
In Example 12, the dyes used are the following dye Nos. Except for changing to the sodium salt of (II-9), a dye composition for an anisotropic dye film was similarly prepared, and an anisotropic dye film was obtained by applying the same composition to the same substrate under the same conditions.
Table 3 shows the chromaticity xy (XYZ color system), maximum absorption wavelength (λ _max ), and dichroic ratio (D) of the obtained anisotropic dye film. The obtained anisotropic dye film was an anisotropic dye film having a high dichroic ratio that can sufficiently function as a polarizing film.

（実施例１５）
水９０部に下記に示す色素Ｎｏ．（II−３）のナトリウム塩を１０部加え、撹拌溶解後濾過して異方性色素膜用色素組成物を得た。このものを実施例１２で用いた基板にギャップ１０μｍのアプリケーター（井元製作所社製）で塗布した後、自然乾燥することにより異方性色素膜を得た。
得られた異方性色素膜の色度ｘｙ（ＸＹＺ表色系）、極大吸収波長（λ_max）、二色比（D）を表３に示す。得られた異方性色素膜は偏光膜として充分機能し得る高い二色比を有する異方性色素膜であった。

(Example 14)
In 90 parts of water, the following dye No. 10 parts of the sodium salt of (II-2) was added, dissolved with stirring, and filtered to obtain a dye composition for anisotropic dye film. This was coated on the substrate used in Example 12 with a No. 3 bar coater (manufactured by Tester Sangyo Co., Ltd.) and then naturally dried to obtain an anisotropic dye film.
Table 3 shows the chromaticity xy (XYZ color system), maximum absorption wavelength (λ _max ), and dichroic ratio (D) of the obtained anisotropic dye film. The obtained anisotropic dye film was an anisotropic dye film having a high dichroic ratio that can sufficiently function as a polarizing film.

(Example 15)
In 90 parts of water, the following dye No. 10 parts of the sodium salt of (II-3) was added, dissolved with stirring, and filtered to obtain a dye composition for anisotropic dye film. This was coated on the substrate used in Example 12 with an applicator (manufactured by Imoto Seisakusho) with a gap of 10 μm, and then naturally dried to obtain an anisotropic dye film.
Table 3 shows the chromaticity xy (XYZ color system), maximum absorption wavelength (λ _max ), and dichroic ratio (D) of the obtained anisotropic dye film. The obtained anisotropic dye film was an anisotropic dye film having a high dichroic ratio that can sufficiently function as a polarizing film.

(Example 16)
Dye No. shown below in 91 parts of water. Nine parts of the sodium salt of (II-4) was added, dissolved with stirring, and filtered to obtain a dye composition for anisotropic dye film. An anisotropic dye film was obtained by coating under the same conditions as in Example 15.
Table 3 shows the chromaticity xy (XYZ color system), maximum absorption wavelength (λ _max ), and dichroic ratio (D) of the obtained anisotropic dye film. The obtained anisotropic dye film was an anisotropic dye film having a high dichroic ratio that can sufficiently function as a polarizing film.

(Example 17)
In 93 parts of water, the dye No. 7 parts of the sodium salt of (II-6) was added, dissolved by stirring and filtered to obtain a dye composition for anisotropic dye film. An anisotropic dye film was obtained by coating under the same conditions as in Example 15.
Table 3 shows the chromaticity xy (XYZ color system), maximum absorption wavelength (λ _max ), and dichroic ratio (D) of the obtained anisotropic dye film. The obtained anisotropic dye film was an anisotropic dye film having a high dichroic ratio that can sufficiently function as a polarizing film.

(Comparative Example 2)
A dye aqueous solution and a dye film were prepared in the same manner as in Example 8 except that a dye having the following structural formula was used instead of the dye of (I-1).

  FIG. 8 shows the transmittance characteristics in the absorption axis direction and the polarization axis direction of this dye film. The resulting dye film had a maximum absorption wavelength (λmax) of 585 nm and a dichroic ratio of 3.

(Comparative Example 3)
In Example 12, the no. Instead of the dye of (II-1), No. A dye composition for a dye film was prepared in the same manner except that the sodium salt of the dye (III-1) in which the substituent G ¹ of (II-1) is para to the azo group was used, and the same substrate The coating was carried out under the same conditions to obtain a dye film.
The obtained dye film was subjected to various tests in the same manner as in Example 12. The results are shown in Table 4. The obtained dye film had a dichroic ratio (absorption anisotropy) of 2 or less, and did not exhibit sufficient anisotropy.

(Comparative Example 4)
In Example 12, the no. Instead of the dye of (II-1), No. A dye composition for a dye film was prepared in the same manner except that the following dye (III-2) in which the substituent G ¹ of (II-1) was in the ortho position was used, and the same conditions were applied to the same substrate. Coating was performed to obtain a dye film.
The obtained dye film was subjected to various tests in the same manner as in Example 12. The results are shown in Table 4. The obtained dye film had a dichroic ratio (absorption anisotropy) of 2 or less, and did not exhibit sufficient anisotropy.

(Comparative Example 5)
No. shown below in 95 parts of water. A dye composition for a dye film was obtained by adding 5 parts of the dye of (III-3), stirring and dissolving, and filtering. This was coated on the substrate used in Example 12 with a No. 3 bar coater (manufactured by Tester Sangyo Co., Ltd.) and then naturally dried to obtain an anisotropic dye film.
The obtained dye film was subjected to various tests in the same manner as in Example 12. The results are shown in Table 4. The obtained dye film had a dichroic ratio (absorption anisotropy) of 2 or less, and did not exhibit sufficient anisotropy.

(Comparative Example 6)
In Example 12, the no. A dye composition for a dye film was prepared in the same manner except that the dye (III-4) shown below was used instead of the dye (II-1), and the dye was applied to the same substrate under the same conditions. A membrane was obtained.
The obtained dye film was subjected to various tests in the same manner as in Example 12. The results are shown in Table 4. The obtained dye film had a dichroic ratio (absorption anisotropy) of 2 or less, and did not exhibit sufficient anisotropy.

(Comparative Example 7)
In Example 12, the no. A dye composition for a dye film was prepared in the same manner except that the sodium salt of dye (III-5) shown below was used in place of the dye of (II-1), and applied to the same substrate under the same conditions. To obtain a dye film.
The obtained dye film was subjected to various tests in the same manner as in Example 12. The results are shown in Table 4. The obtained dye film had a dichroic ratio (absorption anisotropy) of 2 or less, and did not exhibit sufficient anisotropy.

[4] Stimulus purity (Examples 18 and 19)
(Example 18)
In 99.9 parts of water, the dye No. 0.1 part of the sodium salt of (II-1) was added, dissolved by stirring and filtered to obtain an aqueous dye solution. This aqueous solution was poured into a quartz square cell (cuvette) having an optical path length of 0.1 mm. The visible light transmittance of the aqueous dye solution injected into this cuvette and the anisotropic dye film obtained in Example 12 were measured with a spectrophotometer, respectively, and the chromaticity xy under the CIE1964 XYZ color system, D65 standard light source was determined. Calculated.

  Further, from the chromaticity diagram, the chromaticity coordinate N of the D65 standard light source, the chromaticity coordinate C1 of the aqueous dye solution and the chromaticity coordinate C2 of the anisotropic dye film are each connected by a straight line, and at the intersection of the extended spectrum locus With the corresponding wavelength as the dominant wavelength, the stimulation purity (pe1) of the dye aqueous solution and the stimulation purity (pe2) of the anisotropic dye film were calculated from the ratio of each point. Table 5 shows the stimulus purity of the dye aqueous solution and the stimulus purity of the anisotropic dye film.

  The stimulation purity of the dye (dye aqueous solution) of this example was 12% or less. The stimulating purity of the anisotropic dye film prepared using this dye is also 12% or less, which is useful as an anisotropic dye film having a low chroma and achromatic color.

(Example 19)
The stimulating purity of the dyes used in Examples 13 to 17 and the anisotropic dye films obtained in Examples 13 to 17 were measured and calculated in the same manner as in Example 18. Table 5 shows the stimulus purity of each dye aqueous solution and the stimulus purity of the anisotropic dye film.
The stimulation purity of the dye (dye aqueous solution) of this example was 12% or less. The stimulating purity of the anisotropic dye film prepared using this dye is also 12% or less, which is useful as an anisotropic dye film having a low chroma and achromatic color.

It is a schematic diagram showing an anisotropic dye film having a molecular arrangement in which the dye molecule surface is inclined from the perpendicular to the molecular stacking axis. It is a schematic diagram showing an anisotropic dye film having a molecular arrangement in which a dye molecule surface is perpendicular to a molecular stacking axis. (A) is a schematic diagram showing an anisotropic dye film in a state where the orientation degree of the molecular stacking axis is low, and (b) is a schematic diagram showing the anisotropic dye film in a state where the orientation degree of the molecular stacking axis is high. FIG. 3 is a chart showing an X-ray diffraction profile of an anisotropic dye film formed in Example 1. FIG. 3 is a chart showing an in-plane rocking profile of the anisotropic dye film formed in Example 1. FIG. 10 is a graph showing light transmittances in the absorption axis direction and the polarization axis direction of the anisotropic dye film obtained in Example 7. It is a graph showing the light transmittance of the anisotropic dye film obtained in Example 10 in the absorption axis direction and the polarization axis direction. It is a graph showing the light transmittance of the anisotropic dye film obtained in Comparative Example 2 in the absorption axis direction and the polarization axis direction.

Claims (19)

  An anisotropic dye film characterized by having a period derived from molecular stacking of 3.445 mm or less and a stacking length of 105 mm or more.   The anisotropic dye film according to claim 1, wherein the degree of orientation of the molecular stacking axis is 85% or more.   The anisotropic pigment | dye film | membrane of Claim 1 or 2 whose film thickness is 30 micrometers or less.   The anisotropic dye film according to claim 1, which is an anisotropic dye film formed on a substrate.   The anisotropic dye film according to claim 4, which is an anisotropic dye film formed by a wet film formation method.   The anisotropic dye film according to claim 4 or 5, wherein the substrate is glass or a resin film.   The anisotropic dye film according to claim 1, further comprising a protective layer. The anisotropic dye film according to any one of claims 1 to 7, comprising an azo dye whose free acid form is represented by the following general formula (1).

(In the formula, A ⁰ , B ⁰ , C ⁰ and D ⁰ each independently represents an aromatic hydrocarbon ring which may have a substituent,
Ar ⁰ represents a hydrogen atom or an arbitrary substituent,
X ⁰ and Y ⁰ each independently represent an arbitrary substituent other than a halogen atom.
k represents 1 or 2, and m represents 1 or 2. When k is 2, a plurality of B ⁰ contained in one molecule may be the same or different. ) The anisotropy according to claim 8, wherein the azo dye whose free acid form is represented by the general formula (1) is an azo dye whose free acid form is represented by the following general formula (1-a). Dye film.

(In the formula, A ¹ represents a phenyl group which may have a substituent, or a naphthyl group which may have a substituent;
B ¹ and C ¹ each independently represent a phenylene group which may have a substituent, or a naphthylene group which may have a substituent,
Ar ¹ represents a hydrogen atom or an optionally substituted alkyl group having 1 to 5 carbon atoms,
X ¹ and Y ¹ each independently represent a —NR ¹ R ² group, a —OR ³ group, or a —SR ⁴ group.
However, R ¹ , R ² , R ³ and 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 optionally substituted hydrocarbon ring group having 3 to 15 carbon atoms, an optionally substituted 5- or 6-membered ring, monocyclic ring or 2-3 It represents a heterocyclic group consisting of a condensed ring, or R ¹ and R ² are bonded to each other to form a 5- or 6-membered ring containing a nitrogen atom. The ring formed by bonding R ¹ and R ² may have a substituent.
k represents 1 or 2, and m represents 1 or 2. When k is 2, a plurality of B ¹ contained in one molecule may be the same or different. ) The anisotropic dye film according to any one of claims 1 to 7, comprising an azo dye whose free acid form is represented by the following general formula (2).

(In the formula, D ¹ and E ¹ represent a phenylene group which may have a substituent, or a naphthylene group which may have a substituent,
G ¹ represents a carboxy group, a sulfo group, or a phosphate group,
Q ¹ may have a halogen atom, a hydroxyl group, a nitro group, an amino group which may have a substituent, an alkyl group having 1 to 4 carbon atoms which may have a substituent, or a substituent. Represents an alkoxy group having 1 to 3 carbon atoms, a carboxyl group, or a sulfo group;
Q ² and Q ³ each independently represent a hydrogen atom, an optionally substituted alkyl group having 1 to 4 carbon atoms, or an optionally substituted phenyl group,
p represents 0 or 1, and t represents 1 or 2. ) An azo dye whose free acid form is represented by the following general formula (1).

(In the formula, A ⁰ , B ⁰ , C ⁰ and D ⁰ each independently represents an aromatic hydrocarbon ring which may have a substituent,
Ar ⁰ represents a hydrogen atom or an arbitrary substituent,
X ⁰ and Y ⁰ each independently represent an arbitrary substituent other than a halogen atom.
k represents 1 or 2, and m represents 1 or 2. When k is 2, a plurality of B ⁰ contained in one molecule may be the same or different. ) The azo dye according to claim 11, wherein the form of the free acid is represented by the following general formula (1-a).

(In the formula, A ¹ represents a phenyl group which may have a substituent, or a naphthyl group which may have a substituent;
B ¹ and C ¹ each independently represent a phenylene group which may have a substituent, or a naphthylene group which may have a substituent,
Ar ¹ represents a hydrogen atom or an optionally substituted alkyl group having 1 to 5 carbon atoms,
X ¹ and Y ¹ each independently represent a —NR ¹ R ² group, a —OR ³ group, or a —SR ⁴ group.
However, R ¹ , R ² , R ³ and 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 optionally substituted hydrocarbon ring group having 3 to 15 carbon atoms, an optionally substituted 5- or 6-membered ring, monocyclic ring or 2-3 It represents a heterocyclic group consisting of a condensed ring, or R ¹ and R ² are bonded to each other to form a 5- or 6-membered ring containing a nitrogen atom. The ring formed by bonding R ¹ and R ² may have a substituent.
k represents 1 or 2, and m represents 1 or 2. When k is 2, a plurality of B ¹ contained in one molecule may be the same or different. )   The azo dye according to claim 11 or 12, having a molecular weight of 500 to 5,000. An azo dye for an anisotropic dye film formed by a wet film formation method, wherein the form of a free acid is represented by the following general formula (2).

(In the formula, D ¹ and E ¹ represent a phenylene group which may have a substituent, or a naphthylene group which may have a substituent,
G ¹ represents a carboxy group, a sulfo group, or a phosphate group,
Q ¹ may have a halogen atom, a hydroxyl group, a nitro group, an amino group which may have a substituent, an alkyl group having 1 to 4 carbon atoms which may have a substituent, or a substituent. Represents an alkoxy group having 1 to 3 carbon atoms, a carboxyl group, or a sulfo group;
Q ² and Q ³ each independently represent a hydrogen atom, an optionally substituted alkyl group having 1 to 4 carbon atoms, or an optionally substituted phenyl group,
p represents 0 or 1, and t represents 1 or 2. )   The azo dye according to claim 14, which is a dye having an excitation purity of 0 to 12%.   A dye composition for an anisotropic dye film, comprising the azo dye according to claim 11.   An anisotropic dye film containing the azo dye according to claim 11.   An anisotropic dye film formed using the dye composition for an anisotropic dye film according to claim 16.   A polarizing element using the anisotropic dye film according to any one of claims 1 to 10, 17, and 18.

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