JP5381634B2 - Anisotropic dye film and polarizing element - Google Patents

Description

  The present invention relates to an anisotropic dye film, a coordination polymer for an anisotropic dye film, and a polarizing element, and more particularly to an anisotropic dye film and a polarizing element containing a coordination polymer.

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

  Conventionally, in these polarizing plates, iodine or dichroic organic dyes are 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, see Patent Document 1).

  However, the conventional anisotropic dye film produced in this manner does not have sufficient heat resistance and light resistance depending on the dye and polymer material used, and the yield of bonding of the anisotropic dye film at the time of liquid crystal device production There were problems such as bad. 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.

  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 for producing an anisotropic dye film by orienting a functional dye (for example, see Patent Document 2) has been studied.

  In applications as polarizing elements, anisotropic dye films with high dichroism are required in order to obtain higher polarization performance, but these conventional anisotropic dye films are inferior in dichroism. Therefore, a polarizing element having excellent 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.

  However, since the compound described in Patent Document 1 has insufficient dichroism and low solubility in various solvents, it is a material for anisotropic dye films produced by a wet film formation method. That's not enough.

  Patent Document 2 describes that an anisotropic dye film produced by a wet film-forming method is prepared. As an example of a dichroic dye that can be used, one represented by the following structural formula is described. ing.

  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.

  In contrast to these technologies, Patent Document 3 has a high anisotropy by using a dichroic azo dye having a specific structure and having a triazinyl group and having three or more azo bonds in one molecule. It is described that an anisotropic dye film can be obtained.

  However, according to this technique, although the dichroic ratio of the obtained anisotropic dye film is improved, it is insufficient, and a technique capable of realizing further improvement of the dichroic ratio has been demanded.

  Further, when used for a polarizing film, a film having a deep color tone is preferable, and the hue needs to be a neutral color in the visible wavelength region. Usually, a mixture of two or more dichroic dyes is used. Although a sexual color is produced, the structure differs greatly for each dye, so the dichroic ratio is also different, and a great deal of labor is required for its adjustment.

  As described above, conventionally known dichroic dyes are insufficient in terms of performance, but not only that, synthesis from raw materials to the target product is multistage, and much effort is required to purify the target product. In the past, there were many problems in manufacturing, such as.

  By the way, a coordination polymer having a repetitive structure due to a continuous interaction between a metal ion and a ligand has a variety of metal ions as an inorganic compound and an excellent degree of freedom in molecular design of a ligand as an organic compound. Have both. Therefore, it is possible to construct a space and an electronic structure that cannot be realized by an inorganic compound or an organic compound alone, thereby enabling the expression of new functions, and industrial use is expected (for example, Patent Document 4). reference). On the other hand, there has been no example so far regarding the function of a coordination polymer as a dichroic dye and application to an anisotropic dye film.

Japanese Patent Laid-Open No. 3-12606 International Publication No. 2002/099480 Pamphlet International Publication No. 2005/035667 Pamphlet JP 2007-1112769 A

  The present invention has been made in view of the above problems, and the object thereof is an anisotropic dye film exhibiting high dichroism and good durability, a coordination polymer for anisotropic dye film, and polarization performance. An object of the present invention is to provide an excellent polarizing element.

  As a result of intensive studies, the present inventors have found that an anisotropic dye film exhibiting high dichroism and good durability can be obtained by using a coordination polymer, and completed the present invention. .

  Coordination polymers are easy to manufacture and have a high degree of freedom in molecular design for color tone control, so compared with conventional anisotropic dye films and polarizing elements using dichroic dyes. An anisotropic dye film and a polarizing element using the coordination polymer of the invention can be manufactured at a considerably low cost and easily.

  The above object of the present invention can be achieved by the following configuration.

  1. An anisotropic dye film comprising a coordination polymer.

  2. 2. The anisotropic dye film as described in 1 above, wherein the coordination polymer is a linear polymer.

  3. 3. The anisotropic dye film as described in 1 or 2 above, wherein the coordination polymer has a partial structure represented by the following general formula (1) in the main chain.

[Wherein, M ₁ and M ₂ each represent a metal ion and may be the same or different, and X ₁ and X ₂ each represent a nitrogen atom, an oxygen atom or a sulfur atom, and may each be the same. It may be different. L represents a group for linking X ₁ and X ₂ containing a carbon atom. ]
4). 4. The anisotropic dye film as described in 3 above, wherein the coordination polymer has a 5- or 6-membered nitrogen-containing heterocycle.

  5. 5. The anisotropic dye film as described in 4 above, wherein the coordination polymer contains a metal ion and a compound represented by the following general formula (2).

[Wherein, J represents a mere bond or a divalent linking group, and Z _{1 to} Z ₄ each represents a group of nonmetallic atoms necessary for forming a 5- or 6-membered nitrogen-containing heterocycle together with the C═N part. Represents. ]
6). 6. The anisotropic dye film as described in any one of 1 to 5, wherein the coordination polymer contains a different metal ion.

  7). 7. A polarizing element using at least one anisotropic dye film according to any one of 1 to 6 above.

  8). A coordination polymer for an anisotropic dye film, characterized in that the main chain has a partial structure represented by the following general formula (1).

[Wherein, M ₁ and M ₂ each represent a metal ion and may be the same or different, and X ₁ and X ₂ each represent a nitrogen atom, an oxygen atom or a sulfur atom, and may each be the same. It may be different. L represents a group for linking X ₁ and X ₂ containing a carbon atom. ]

  The present invention can provide an anisotropic dye film that exhibits high dichroism and good durability, a coordination polymer for an anisotropic dye film, and a polarizing element excellent in polarization performance.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail, but the present invention is not limited thereto.

  In the present invention, the term “anisotropic dye film” refers to 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. It refers to a dye film having anisotropy. 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 linearly polarizing film, a circularly polarizing film, a retardation film, and a resistivity anisotropic dye film. That is, the anisotropic dye film of the present invention described later can be used for a polarizing film, a retardation film, or a resistivity anisotropic dye 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 dichroic ratio of the anisotropic dye film is determined by the ratio of the absorption coefficient between 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 kx 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 other words, when a film is formed by a wet film forming method, a larger number of molecules arranged in the same direction is preferable because a higher dichroic ratio is expected. For that purpose, it seems desirable that the interaction force between the dye molecules is large in order to promote the self-assembly of the dye.

[Coordination polymer]
In the present invention, the coordination polymer means a crosslinked structure in which polyfunctional ligands (bridged ligands) are coordinated to different metal ions, and the metal ions and the ligands are alternately arranged. It is a polymer compound produced by long alignment. That is, it means a polymer in the form of-(metal ion)-(ligand)-(metal ion)-(ligand)-(metal ion)-.

  The present invention is characterized in that the anisotropic dye film contains a coordination polymer. Coordination polymers absorb light based on transitions involving electron transfer between a ligand and a metal ion and function as dyes, but surprisingly, we function as such dyes. It has been found that a dye film produced by a dry film forming method or a wet film forming method described later using a coordination polymer is anisotropic. Details are unknown, but the molecular arrangement between coordination polymers has increased, and the consistency of the direction of transition with electron transfer between each ligand and each metal ion forming the coordination polymer This is presumed to be due to the improvement of the so-called dichroism.

  In the present invention, the metal ion is not particularly limited as long as it forms a coordination polymer, but is not limited to group VIII, group Ib, group IIb, group IIIa, group IVa, group Va, group VIa, group VIIa. Transition metal ions selected from metal atoms are preferred. Specific examples include divalent metal ions of Ni, Cu, Co, Mn, Zn, Fe, Ru, Ti, Pd, and Pt, and more preferably, divalent metals of Ni, Cu, Co, Mn, Fe, and Ru. The metal ion is preferably a divalent metal ion of Fe.

  The metal ions in the coordination polymer may be composed of the same metal ions or different metal ions, and the ligands in the coordination polymer are the same ligands. Even if comprised, it may be comprised by the heterogeneous ligand.

  In the coordination polymer, an anion necessary for neutralizing the cation of the metal ion is present. When the charge of the ligand is neutral, there is a separate counter anion to neutralize the cation of the metal ion, while when the ligand is anionic, the counter anion that neutralizes the cation of the metal ion is In some cases, it may be the ligand itself, or in other cases.

In the present invention, examples of counter anions include aliphatic carboxylate ions (acetate ions, propionate ions, etc.), aromatic carboxylate ions (benzoate ions, etc.), sulfate ions, sulfonate ions (methanesulfonate, tosyl). Acid ion, etc.), halogen ion (chloride ion, bromide ion, etc.), phosphate ion, phosphate ester ion (phosphate monoethyl ester ion, phosphate phosphate ester ion, etc.), hydroxide ion, carbonate ion, polyoxy Metalates, PF ₆ ⁻ , BF ₄ ⁻ , SbF ₆ ^{— and the} like may be mentioned, and these may be combined in the coordination polymer. These counter anions are usually used as a counter ion (counter salt) of a metal ion during the synthesis of a coordination polymer, but may be subjected to salt exchange after the synthesis of the coordination polymer.

  In the present invention, the ligand is not particularly limited as long as it is a polyfunctional ligand, and examples thereof include compounds having a plurality of nitrogen atoms, oxygen atoms or sulfur atoms having an unshared electron pair.

  There are no particular limitations on the starting metal salt used in the synthesis of the coordination polymer, but metal acetates or metal chloride salts are preferred in view of cost and availability.

  The number average molecular weight (Mn) of the coordination polymer of the present invention is in the range of 1,000 to 100,000, and preferably in the range of 2,000 to 20,000 from the viewpoint of solubility in various solvents. . The weight average molecular weight (Mw) of the coordination polymer of the present invention is in the range of 1,000 to 500,000, and preferably 5,000 to 100,000 from the viewpoints of solubility and film forming property.

(Molecular weight measurement method)
The number average molecular weight (Mn) and the weight average molecular weight (Mw) are measured using gel permeation chromatography.

  The measurement conditions are as follows.

Solvent: 1M sodium acetate / acetonitrile = 7/3
Column: TSKgel α-M, α-2500 (used by connecting two Tosoh Corporation)
Column temperature: 40 ° C
Sample concentration: 0.1% by mass
Detector: RI Model 504 (manufactured by GL Sciences)
Pump: L6000 (manufactured by Hitachi, Ltd.)
Flow rate: 0.5ml / min
Calibration curve: Standard PEO / PEG conversion The coordination polymer in the present invention has absorption in the visible region due to the charge transfer transition between the ligand and the metal ion, and the combination of the ligand and the metal ion Since the speed of charge transfer is different, a desired color can be obtained by appropriately combining a ligand and a metal ion. This rate of charge transfer can also be controlled by changing the counter anion.

[Linear polymer]
In the present invention, the linear polymer is a chain in which structural units (monomers, etc.) are linearly connected as defined in “Basic Polymer Science” (published by Tokyo Chemical Doujin). It is also expressed as a polymer or a one-dimensional polymer.

  The coordination polymer in the present invention is preferably a linear polymer, and the ligand forming the coordination polymer is preferably bifunctional.

  The inventors of the present invention have found that linear coordination polymers having excellent linearity easily have transition moments of light absorption based on individual charge transfer transitions, and therefore an anisotropic dye film from the viewpoint of absorption anisotropy. In particular, they have been found to be useful for polarizing elements that require a polarizing function.

  The coordination polymer in the present invention is preferably a coordination polymer having a partial structure represented by the general formula (1) in order to develop anisotropy and enhance polarization performance.

[Partial structure represented by general formula (1)]
In the general formula (1), M ₁ and M ₂ represent metal ions, which may be the same or different.

In the general formula (1), the metal ions represented by M ₁ and M ₂ are not particularly limited as long as they form a coordination polymer, but are not limited to group VIII, group Ib, group IIb, group IIIa. , Transition metal ions selected from group IVa, Va, VIa, and VIIa metal atoms are preferred. Specific examples include divalent metal ions of Ni, Cu, Co, Mn, Zn, Fe, Ru, Ti, Pd, and Pt, and more preferably, divalent metals of Ni, Cu, Co, Mn, Fe, and Ru. The metal ion is preferably a divalent metal ion of Fe.

In the general formula (1), X ₁ and X ₂ represent a nitrogen atom, an oxygen atom or a sulfur atom, and may be the same or different. X ₁ and X ₂ are preferably nitrogen atoms.

In the general formula (1), L represents a group connecting X ₁ and X ₂ containing a carbon atom, and L forms a bifunctional organic ligand together with X ₁ and X ₂ . Examples of the bifunctional organic ligand include bisterpyridine, bisphenanthroline, bisbipyridine, and the like.

  The coordination polymer having a partial structure represented by the general formula (1) in the present invention is a coordination polymer having a 5- or 6-membered nitrogen-containing heterocyclic ring, and has a coordination power with a metal. Therefore, it is preferable in order to develop anisotropy and enhance polarization performance.

[5- or 6-membered nitrogen-containing heterocycle]
Examples of the 5- or 6-membered nitrogen-containing heterocyclic ring include pyridine ring, pyrazole ring, imidazole ring, pyrazine ring, pyrimidine ring, pyridazine ring, triazine ring, thiazole ring, isothiazole ring, thiadiazole, oxazole ring and isoxazole ring. , Oxadiazole ring, triazole ring, tetrazole ring, quinoline ring, isoquinoline ring, benzothiazole ring, benzoisothiazole ring, benzoxazole ring, benzoisoxazole ring, benzopyrazole ring, benzimidazole ring, etc. Can do. Preferred are a pyridine ring, a pyrazole ring and an imidazole ring, and particularly preferred is a pyridine ring.

  In the present invention, the coordination polymer having a 5- or 6-membered nitrogen-containing heterocyclic ring is a coordination polymer containing a metal ion and a compound represented by the general formula (2), and is excellent in linearity. In addition, since the coordinating power with the metal is increased, it is preferable for developing anisotropy and enhancing the polarization performance.

  The metal ion is not particularly limited as long as it forms a coordination polymer, but is selected from metal atoms of group VIII, group Ib, group IIb, group IIIa, group IVa, group Va, group VIa, group VIIa. Transition metal ions are preferred. Specific examples include divalent metal ions of Ni, Cu, Co, Mn, Zn, Fe, Ru, Ti, Pd, and Pt, and more preferably, divalent metals of Ni, Cu, Co, Mn, Fe, and Ru. The metal ion is preferably a divalent metal ion of Fe.

[Compound represented by the general formula (2)]
In the general formula (2), J represents a simple bond or a divalent linking group. Examples of the divalent linking group include an alkylene group that may have a substituent (for example, a methylene group, an ethylene group, and a trimethylene group), and a cycloalkylene group that may have a substituent (for example, a cyclohexylene group). ), An alkenylene group (for example, ethenylene group, propenylene group, butenylene group, etc.) that may have a substituent, an ethynylene group, an arylene group that may have a substituent (for example, a phenylene group, a naphthylene group, etc.), Carbonyl group, oxygen atom, nitrogen atom, sulfur atom (for example, thioether group, sulfonyl group, etc.) or a combination of these linking groups (for example, aralkylene group, ester group, alkoxycarbonyl group, carbamoyl group, amide group, sulfamoyl) Group, sulfonamide group, disulfide group, hydrazino group, azo group, etc.) J is preferably an arylene group, more preferably a phenylene group, and particularly preferably a 1,4-phenylene group or a combination of 1,4-phenylene groups.

  In the general formula (2), examples of the substituent that the divalent linking group represented by J may have include an alkyl group (for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, tert-butyl). Group, pentyl group, hexyl group, octyl group, dodecyl group, trifluoromethyl group, etc.), cycloalkyl group (eg, cyclopentyl group, cyclohexyl group, etc.), aryl group (eg, phenyl group, naphthyl group, etc.), acylamino group (Eg, acetylamino group, benzoylamino group, etc.), alkylthio group (eg, methylthio group, ethylthio group, etc.), arylthio group (eg, phenylthio group, naphthylthio group, etc.), alkenyl group (eg, vinyl group, 2-propenyl) Group, 3-butenyl group, 1-methyl-3-propenyl group, 3-pentenyl group, 1-methyl -3-butenyl group, 4-hexenyl group, cyclohexenyl group, etc.), halogen atom (eg, fluorine atom, chlorine atom, bromine atom, iodine atom etc.), alkynyl group (eg, propargyl group etc.), heterocyclic group ( For example, pyridyl group, thiazolyl group, oxazolyl group, imidazolyl group, etc.), alkylsulfonyl group (eg, methylsulfonyl group, ethylsulfonyl group, etc.), arylsulfonyl group (eg, phenylsulfonyl group, naphthylsulfonyl group, etc.), alkylsulfinyl A group (for example, a methylsulfinyl group), an arylsulfinyl group (for example, a phenylsulfinyl group), a phosphono group, an acyl group (for example, an acetyl group, a pivaloyl group, a benzoyl group, etc.), a carbamoyl group (for example, an aminocarbonyl group, Methylaminocarbonyl group, Methylaminocarbonyl group, butylaminocarbonyl group, cyclohexylaminocarbonyl group, phenylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc.), sulfamoyl group (for example, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl) Group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, dodecylaminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), sulfonamide group (for example, methanesulfonamide group) , Benzenesulfonamido group, etc.), cyano group, alkoxy group (for example, methoxy group, ethoxy group, propoxy group, etc.), aryloxy group (for example, Phenoxy group, naphthyloxy group, etc.), heterocyclic oxy group, siloxy group, acyloxy group (eg, acetyloxy group, benzoyloxy group, etc.), sulfonic acid group, sulfonic acid salt, aminocarbonyloxy group, amino group (eg, Amino group, ethylamino group, dimethylamino group, butylamino group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group, etc.), anilino group (for example, phenylamino group, chlorophenylamino group, toluidino group, anisidino group) , Naphthylamino group, 2-pyridylamino group, etc.), imide group, ureido group (for example, methylureido group, ethylureido group, pentylureido group, cyclohexylureido group, octylureido group, dodecylureido group, phenylureido group, naphthylureido) Group, 2 Pyridylaminoureido group etc.), alkoxycarbonylamino group (eg methoxycarbonylamino group, phenoxycarbonylamino group etc.), alkoxycarbonyl group (eg methoxycarbonyl group, ethoxycarbonyl group, phenoxycarbonyl etc.), aryloxycarbonyl group (eg , Phenoxycarbonyl group, etc.), heterocyclic thio group, thioureido group, carboxyl group, carboxylic acid salt, hydroxyl group, mercapto group, nitro group and the like. These substituents may be further substituted with the same substituent.

In the general formula (2), Z _{1 to} Z ₄ each represents a nonmetallic atom group necessary for forming a 5- or 6-membered nitrogen-containing heterocyclic ring together with the C═N part. Specific examples of nitrogen-containing heterocycle include pyridine ring, pyrazole ring, imidazole ring, pyrazine ring, pyrimidine ring, pyridazine ring, triazine ring, thiazole ring, isothiazole ring, thiadiazole, oxazole ring, isoxazole ring, oxadiazole ring , Triazole ring, tetrazole ring, quinoline ring, isoquinoline ring, benzothiazole ring, benzoisothiazole ring, benzoxazole ring, benzoisoxazole ring, benzopyrazole ring, benzimidazole ring and the like. Preferred are a pyridine ring and a benzimidazole ring, and particularly preferred is a pyridine ring. These rings may have a substituent, and examples of the substituent include the same groups as the substituent that the divalent linking group represented by J may have, and the same substituents. It may be substituted by a group. Z _{1 to} Z ₄ may be the same or different.

[Coordination polymers for anisotropic dye films]
The coordination polymer for anisotropic dye film of the present invention has a partial structure represented by the general formula (1) in the main chain.

In the general formula (1), M ₁ and M ₂ represent metal ions, which may be the same or different, and X ₁ and X ₂ represent a nitrogen atom, an oxygen atom or a sulfur atom, and are the same Or different. L represents a group for linking X ₁ and X ₂ containing a carbon atom.

In the general formula (1), examples of M ₁ , M ₂ , X ₁ , X _2, and L include the same as those described above, and are the same as those described above. May have a counter anion.

  The coordination polymer for an anisotropic dye film of the present invention having the partial structure represented by the general formula (1) in the main chain is excellent in linearity, and an anisotropic dye from the viewpoint of absorption anisotropy. It is useful for a film, particularly a polarizing film that requires a polarizing function. Furthermore, by selecting the type and combination of the terminal group and side substituent of the main axis of the coordination polymer, the intermolecular interaction between the coordination polymer and the polymer material or coordination polymer to be combined with it can be made arbitrarily. It is possible to control. Moreover, since the coordination polymer of the present invention is excellent in heat resistance, it can be used in anisotropic dye films for various applications that require heat resistance.

  Specific examples of the coordination polymer according to the present invention are shown below, but the present invention is not limited thereto. In addition, n in the structural formula described as an exemplary compound means that a plurality of structures in parentheses are repeated.

[Production method]
The coordination polymer of the present invention can be produced according to a conventionally known method. For example, Synthesis 2006, No. 1; 17, 2873-2878 and JP-A No. 2007-1212769 can be referred to to synthesize a ligand and a coordination polymer. The present invention is not limited by these methods.

[Anisotropic dye film]
The anisotropic dye film of the present invention contains at least the coordination polymer of the present invention described above. The anisotropic dye film of the present invention may contain only one type of coordination polymer of the present invention alone, or may contain two or more types in any combination and ratio.

Moreover, in addition to the 1 type (s) or 2 or more types of coordination polymer | macromolecule of this invention, you may contain 1 type (s) or 2 or more types of other pigment | dyes. In particular, an anisotropic dye film having various hues can be produced by appropriately selecting and blending a dye other than the coordination polymer of the present invention within a range in which the orientation is not lowered. In particular, when used for a polarizing film, a film having a deep color tone is preferable, and a neutral color (neutral gray in the visible wavelength region of 380 to 780 nm is used as the hue. For example, in the L ^* a ^* b ^* color system, √ { (A ^* ) ² + (b ^* ) ² } represents a composition satisfying 5), which is preferable as a polarizer for a display element, particularly a color display element.

  Since the coordination polymer of the present invention can control the hue by changing the metal ion, the coordination polymer of the present invention can be used without using another dye in order to exhibit a neutral color. In this case, it is preferable to contain two or more different metal ions.

  When the anisotropic dye film of the present invention contains a dye other than the coordination polymer of the present invention (hereinafter referred to as “compounding dye”), examples of the compounding dye 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.

  In addition, even when the anisotropic dye film of the present invention contains the above-described compounding dye in addition to the coordination polymer of the present invention, from the viewpoint of sufficiently obtaining the effect of the coordination polymer of the present invention, The ratio of the water-soluble dye of the present invention to the total amount (the total amount of the coordination polymer and the compounding dye of the present invention) is usually 70% by mass or more, preferably 85% by mass or more, more preferably 95% by mass or more. Try to be in range.

  The anisotropic dye film of the present invention uses a composition containing at least one or more of the coordination polymers of the present invention (this is referred to as “the dye composition of the present invention”), and will be described later. It is preferable to be manufactured by a film forming method or a wet film forming method. In addition to the above-described coordination polymer of the present invention, the dye composition of the present invention can be used by mixing other dyes (mixing dyes) to such an extent that the orientation is not lowered. Thereby, anisotropic dye films having various hues can be produced.

  The dye composition of the present invention usually further contains a solvent, and the above-described coordination polymer of the present invention and the compounding dye used as necessary are dissolved or dispersed in the solvent. Exists. The coordination polymer of the present invention contained in the dye composition preferably contains the compound represented by the general formula (2) from the viewpoint of solubility 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 alcohol solvents such as methyl alcohol, ethyl alcohol, isopropyl alcohol and glycerin, glycol solvents such as ethylene glycol and diethylene glycol, and cellosolv solvents such as methyl cellosolve and ethyl cellosolve. The above mixed solvent is mentioned.

  On the other hand, depending on the type of counter anion, organic solvents that are not miscible with water, fatty acid ester solvents such as ethyl acetate, aromatic hydrocarbon solvents such as toluene, and halogen solvents such as dichloromethane and chloroform may be used. A mixture of two or more organic solvents that are not miscible with water and the above-mentioned organic solvents that are miscible with water may be used.

  When the dye composition of the present invention is a solution containing such a solvent, the concentration of the dye (coordinating polymer of the present invention and a compounding dye used as necessary) in the dye composition of the present invention is Depending on the film formation method, the solubility of the dye, the formation concentration of the supramolecular structure such as the lyotropic liquid crystal state, etc., it is usually 0.01% by mass or more, preferably 0.1% by mass or more, more preferably 0.8%. It is 5% by mass or more, usually 50% by mass or less, preferably 30% by mass or less, more preferably 25% by mass or less, particularly preferably 20% by mass or less, and most preferably 15% by mass 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.

  Moreover, additives, such as surfactant and a pH adjuster, may be mix | blended with the pigment | dye composition of this invention. These additives are also usually used by dissolving in a solvent.

  In particular, an additive such as a surfactant can be added to the dye composition of the present invention as necessary in order to improve the wettability to the substrate and the coating property. 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 preferably 0.05% by mass or more and 5% by mass or less as the concentration in the dye composition as an amount that does not inhibit the orientation of the dye molecules. 0.5 mass% or less is more preferable.

  Further, for the purpose of suppressing instability such as salt formation and aggregation of the dye in the composition, the dye composition of the present invention usually contains a known pH adjuster such as acid or alkali, It may be added before or after mixing the components of the dye composition or at any point during mixing to adjust the pH. The pH of the dye composition is preferably adjusted to be usually 5 or more, especially 6 or more, and usually 9 or less, especially 8 or less, from the viewpoints of solution stability and ease of handling in production.

  Furthermore, as an additive other than the above, “Additives for Coating”, Edited by J. et al. Known additives described in Bieleman, Willy-VCH (2000) can also be used.

  The anisotropic dye film of the present invention is produced by the dry film forming method or wet film forming method described later using the above-described dye composition of the present invention. Among them, the anisotropic dye film of the present invention is formed because it increases molecular alignment in the anisotropic dye film and obtains high dichroism by utilizing intermolecular interaction between dye molecules. An anisotropic dye film formed by a wet film forming method is preferable to a dry film forming method such as stretching the film.

  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 for an image, is preferable.

  Among the methods for forming an anisotropic dye film, a dry film forming method includes a method of forming a polymer polymer into a film and then dyeing it with the dye composition of the present invention, or Various methods such as glass by adding a dye composition of the present invention to a solution and stretching an unstretched film obtained by a method of forming a film after dyeing the stock solution, or by evaporating the dye composition by heating under vacuum conditions The method of vacuum-depositing on a base material etc. can be mentioned. In addition, as a constituent material of the film dye | stained with the pigment | dye composition of this invention, polymeric materials with high affinity with pigment | dye, such as polyvinyl alcohol, are mentioned.

  Examples of the wet film-forming method include known methods such as a method in which the dye composition of the present invention is prepared as a coating solution and then applied to various substrates such as a glass plate and dried to align and laminate the dye. .

  Examples include “Coating Engineering”, Yuji Harasaki, Asakura Shoten Co., Ltd., published on March 20, 1971, pages 253-277, “Creation and Application of Molecular Coordination Materials”, supervised by Kunihiro Ichimura, Co., Ltd. CMC Publishing, published on March 3, 1998, pages 118 to 149, etc., or spin coating method, spray coating method, bar coating method, roll on a substrate previously subjected to orientation treatment Examples thereof include a coating method, a blade coating method, and the like.

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

  In the wet film formation method, a dye film is formed through a coating process of the dye composition of the present invention on a substrate and a drying process. The operation conditions of these processes are high lyotropic liquid crystals by self-organization of the dye. It is preferable to maintain a higher-order molecular orientation state formed based on the property.

  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. In addition, the temperature is usually 120 ° C. or lower, preferably 110 ° C. or lower. 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, cellulose ester (triacetate, diacetate, acetate propionate, etc.), acrylic, polyester, or urethane resin film. Further, in order to control the orientation direction of the dichroic dye, the surface of the base material is publicly known as described in “Liquid Crystal Handbook”, Maruzen Co., Ltd., issued 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 cellulose ester, acrylic, polyester, polyimide, or urethane film, and is practically used.

  The 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. The dichroic ratio is measured by the following method.

(Dichroic ratio measurement method)
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. Calculate with the following formula.

Dichroic ratio (D) = Az / Ay
Az = -log (Tz)
Ay = -log (Ty)
Tz: Transmittance to polarized light in the absorption axis direction of the dye film Ty: Transmittance to polarized light in the polarization axis direction of the dye film In addition, the anisotropic dye film of the present invention formed on the substrate by a wet film forming method in particular. The film thickness after drying is preferably 50 nm or more, more preferably 100 nm or more, usually 50 μm or less, more preferably 10 μm or less, and even more preferably in the range of 1 μm or less.

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

  The anisotropic dye film of the present invention uses the anisotropy of light absorption and functions as a polarizing film for obtaining linearly polarized light, circularly polarized light, elliptically polarized light, etc., as well as the film forming process and selection of the substrate and dye composition Accordingly, it is possible to make various types of anisotropic dye films such as refractive anisotropy and conduction anisotropy, and it is possible to obtain polarizing elements that can be used in various types and various applications.

  In particular, the anisotropic dye film of the present invention can be directly formed on a highly heat-resistant substrate such as glass in addition to the advantage of being excellent in dichroism as described above. It has the advantage that the polarizing element excellent in can be obtained. Therefore, the anisotropic pigment | dye film | membrane of this invention can be used suitably for the use as which high heat resistance is calculated | required, such as not only a liquid crystal display and an organic EL display, but a liquid crystal projector, a vehicle-mounted display panel.

[Polarizing element]
The polarizing element of the present invention includes at least the anisotropic dye film of the present invention. The polarizing element which consists only of the anisotropic dye film of this invention may be sufficient, and the polarizing element by which the anisotropic dye film of this invention was formed on the suitable board | substrate may be sufficient. A polarizing element having an anisotropic dye film on a substrate is referred to as a polarizing element including a base material.

  When the anisotropic dye film of the present invention is formed on a substrate and used as the polarizing element of the present invention, the formed anisotropic dye film may be used as it is. In addition to the protective layer described above, an adhesive layer or antireflection layer, an alignment film, a function as a retardation film, a function as a brightness enhancement film, a function as a reflection film, a function as a transflective film, a diffusion film Layers having various functions, such as a layer having an optical function such as, may be stacked by a wet film formation method or the like, and used as a stacked body.

  These layers having optical functions can be formed, for example, by the following method.

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

  The layer having a function as a brightness enhancement film may be formed by forming a fine hole by a method as described in, for example, Japanese Patent Application Laid-Open Nos. 2002-169025 and 2003-29030, or the center of selective reflection. It can be formed by overlapping two or more cholesteric liquid crystal layers having different wavelengths.

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

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

  The layer having a function as a retardation film or an optical compensation film can be formed by applying and aligning a liquid crystal compound such as a discotic liquid crystal compound or a nematic liquid crystal compound.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

  In the following description, “part” means “part by mass” unless otherwise specified.

[Example 1]
(Synthesis of Exemplified Compound 1)

  To a 300 ml reaction vessel, 72 ml of acetic acid, 7.20 g of 1,4-bisterpyridinebenzene as a ligand and 2.32 g of iron acetate as a metal salt were added. The mixture was heated and heated to reflux for 6 hours.

  After completion of the reaction, acetic acid was concentrated under reduced pressure, and the resulting residue was dissolved in 60 ml of methanol. When this dissolved solution was slowly dropped into 1 L of toluene while stirring, a purple solid was deposited. Thereafter, the obtained solid was filtered, washed with toluene, and dried to obtain 9.50 g (yield 100%) of Exemplary Compound 1. When the molecular weight of the obtained exemplary compound 1 was confirmed by GPC (gel permeation chromatography) (0.1% by mass concentration), the number average molecular weight (Mn) was 2,900, and the weight average molecular weight (Mw) was 6, It was 300, and it was confirmed that it was a polymer.

  Exemplified Compound 1 obtained above was dissolved in water (1% by mass solution), and the dissolution color was judged by visual observation.

[Example 2]
(Synthesis of Exemplified Compound 2)
Exemplified compound 2 was synthesized in the same manner as in Example 1 except that 3.32 g of cobalt acetate tetrahydrate was used as the metal salt. The yield was 9.40 g (98% yield). When the molecular weight of the obtained exemplary compound 2 was confirmed by GPC (gel permeation chromatography) (0.1% by mass concentration), the number average molecular weight (Mn) was 4,800, and the weight average molecular weight (Mw) was 27. 000, confirming that it was a polymer.

  Exemplified compound 2 obtained above was dissolved in water (1% by mass solution), and when the dissolution color was judged by visual observation, yellowish orange was exhibited.

[Example 3]
(Synthesis of Exemplary Compound 3)
Exemplified compound 3 was synthesized in the same manner as in Example 1 except that 6.45 g of dichlorotetrakis (dimethylsulfoxide) ruthenium (II) was used as the metal salt. The yield was 10.0 g (99% yield). When the molecular weight of the obtained exemplary compound 3 was confirmed by GPC (gel permeation chromatography) (0.1% by mass concentration), the number average molecular weight (Mn) was 3,500, and the weight average molecular weight (Mw) was 13, 000, confirming that it was a polymer.

  Exemplified Compound 2 obtained above was dissolved in a water / methanol = 1/4 mixed solvent (1% by mass solution), and the dissolution color was judged visually.

  As described above in Examples 1 to 3, since Co absorbs light in the blue light region, Ru absorbs in the green light region, and Fe absorbs in the red light region, a neutral color can be formed by mixing them. Is possible.

[Example 4]
Coordination polymer that shows neutral color in one pot by adding iron acetate, cobalt acetate tetrahydrate and dichlorotetrakis (dimethylsulfoxide) ruthenium (II) to 1,4-bisterpyridinebenzene at the same time. It can also be synthesized. An example is shown below.

  In a 300 ml reaction vessel, 72 ml acetic acid, 7.20 g 1,4-bisterpyridinebenzene as ligand, and 0.26 g iron acetate, 2.77 g cobalt acetate tetrahydrate as metal salt, and 0.33 g of dichlorotetrakis (dimethylsulfoxide) ruthenium (II) was added. The mixture was heated and heated to reflux for 6 hours.

  After completion of the reaction, acetic acid was concentrated under reduced pressure, and the resulting residue was dissolved in 60 ml of methanol. When this solution was slowly dropped into 1 L of toluene while stirring, a solid was precipitated. Thereafter, the obtained solid was filtered, washed with toluene, and dried to obtain 9.50 g (yield 100%) of a black gray solid. When the molecular weight of the obtained solid was confirmed by GPC (gel permeation chromatography) (0.1% by mass concentration), the number average molecular weight (Mn) was 4,100, and the weight average molecular weight (Mw) was 22,000. Yes, it was confirmed to be a polymer.

  When the solid obtained above was dissolved in water (1% by mass solution) and the dissolution color was judged by visual observation, it was gray (gray).

[Example 5]
5 parts of the coordination polymer (Exemplary Compound 1) obtained in Example 1 was stirred and dissolved in 95 parts of water to obtain an aqueous solution of the coordination polymer. The obtained aqueous solution was applied onto KC4UE (manufactured by Konica Minolta Opto), which is a cellulose ester film, with an applicator (manufactured by Imoto Seisakusho Co., Ltd.) having a gap of 30 μm, and then naturally dried to form an anisotropic dye film. Obtained. The dichroic ratio at 600 nm of the obtained anisotropic dye film was 26.

  The dichroic ratio was determined as follows.

  After measuring the transmittance of the anisotropic dye film with a spectrophotometer (Otsuka Electronics Co., Ltd. “Instant multi-photometry system MCPD2000”), the dichroic ratio (D) was measured with an iodine polarizing element disposed 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 to polarized light in the absorption axis direction of the dye film Ty: Transmittance to polarized light in the polarization axis direction of the dye film [Example 6]
An aqueous solution of the coordination polymer was obtained by stirring and dissolving 5 parts of the coordination polymer obtained in Example 4 in 95 parts of water.

  In the same manner as in Example 1, the obtained aqueous solution was applied onto KC4UE and naturally dried to obtain an anisotropic dye film. The obtained anisotropic dye film had a dichroic ratio of 25 at 600 nm.

[Comparative Example 1]
A dye composition was obtained by stirring and dissolving 5 parts of the following dye (Exemplary dye (II-3) described in Patent Document 3) in 95 parts of water.

  The obtained dye composition was applied onto KC4UE and dried naturally in the same manner as in Example 5 to obtain an anisotropic dye film. The dichroic ratio at 600 nm of the obtained anisotropic dye film was 8.

[Comparative Example 2]
A 120 μm-thick polyvinyl alcohol film was immersed in an aqueous solution containing 1 part by mass of iodine, 2 parts by mass of potassium iodide, and 4 parts by mass of boric acid, and stretched 4 times at 50 ° C. to prepare an anisotropic dye film. On both sides of this anisotropic dye film, the following alkali saponification treated surfaces of cellulose ester KC4UY (Konica Minolta Opto Co., Ltd.) were bonded from both sides using a completely saponified polyvinyl alcohol 5% aqueous solution as an adhesive. Then, an anisotropic dye film on which a protective film was formed was prepared, and the dichroic ratio was determined by the above-described measurement method. The dichroic ratio at 600 nm was 27.

(Alkaline saponification treatment)
Saponification step: 2 mol / L NaOH, 60 ° C., 60 seconds Water washing step: water 30 ° C., 45 seconds Neutralization step: 10% by mass HCl 30 ° C. 45 seconds Water washing step: water 30 ° C., 45 seconds After saponification treatment, water washing, Neutralization and water washing were carried out in this order, followed by drying at 80 ° C.

[Example 7]
The anisotropic dye films of Example 5, Example 6, Comparative Example 1 and Comparative Example 2 were allowed to stand for 20 hours in an environment at a temperature of 150 ° C., and then measured by measuring the dichroic ratio at 600 nm again. Sex was evaluated.

  The results are shown in Table 1.

  The anisotropic dye film of Comparative Example 2 had curls, cracks, and tears after the durability test, did not form a film, and the dichroic ratio was not measurable. Moreover, the color tone after the durability test of the anisotropic dye film of Comparative Example 2 was changed from neutral gray to brown, and it was found that the stability of the dye was inferior.

  From Table 1, from the comparison between Example 5 and Example 6 and Comparative Example 1 regarding dichroism, and from the comparison between Example 5 and Example 6 and Comparative Example 1 and Comparative Example 2 regarding durability, It can be seen that the anisotropic dye film containing the coordination polymer of the present invention exhibits high dichroism and good durability.

Claims (4)

An anisotropic dye film comprising a coordination polymer having a partial structure represented by the following general formula (1) in the main chain .

[Wherein, M ₁ and M ₂ each represent a metal ion and may be the same or different, X ₁ and X ₂ represent a nitrogen atom, and L represents a nitrogen atom together with X ₁ and X _2. A group that forms a bifunctional organic ligand selected from bisterpyridine, bisphenanthroline, and bisbipyridine. ] The anisotropic dye film according to claim 1, wherein the coordination polymer contains a metal ion and a compound represented by the following general formula (2).

[In the formula, J represents a simple bond or a divalent linking group; ₁ ~ Z ₄ Each represents a group of non-metallic atoms necessary to form a 5- or 6-membered nitrogen-containing heterocyclic ring together with the C═N moiety. ] The anisotropic dye film according to claim 1, wherein the coordination polymer contains a different metal ion. A polarizing element comprising at least one anisotropic dye film according to claim 1.