JP2007241269A - Resin composition, optical element and liquid crystal display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition useful for protecting an anisotropic film by forming a resin layer on the surface of the anisotropic film without making a film thickness of the anisotropic film extremely thick and without accompanying breakage of the anisotropic film, to provide an optical element having the resin layer formed by using the resin composition, and to provide a liquid crystal display element provided with the optical element. <P>SOLUTION: The resin composition is used for forming a resin layer on the surface of the anisotropic film layer made of a lyotropic liquid crystalline compound formed on a substrate by a wet type film forming method and comprises a resin solution made by dissolving a resin into a solvent of which the number of carbon is 4 or more and the common logarithm value (logP) of partition coefficient (P) of octanol/water is 0.5 or more. Further, the optical element has the resin layer formed by applying the resin composition on the surface of the anisotropic film layer of the lyotropic liquid crystalline compound formed on the substrate by a wet type film forming method and drying the applied resin composition. Furthermore, the liquid crystal display element is provided with the optical element. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is a resin composition useful for forming a resin layer on the surface of a polarizing film or a retardation film provided in a display device such as a light control device, a liquid crystal device (LCD), or an organic electroluminescence device (OLED), The present invention also relates to an optical element having a resin layer formed using the resin composition, and a liquid crystal display element including the optical element.

  In LCD, a linearly polarizing plate and a circularly polarizing plate are used for controlling optical rotation and birefringence in display, and in OLED, a circularly polarizing plate is used for preventing reflection of external light, Conventionally, for producing these polarizing plates (polarizing elements), iodine or dichroic organic dyes are dissolved or adsorbed on the surface of a film base material of a polymer material such as polyvinyl alcohol, and stretched in a uniaxial direction. Thus, a method of orienting a dichroic dye or the like (for example, see Non-Patent Document 1) has been widely used. However, depending on the dye or polymer material used, heat resistance, light resistance, etc. are not sufficient. Therefore, usually, a protective film is laminated and laminated, but as a result, the polarizing plate itself becomes a film thickness. Moreover, there were problems such as poor yield when the protective film was bonded.

  On the other hand, a very thin 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 dried. A method of forming an anisotropic film layer by orienting a dichroic dye using an action or the like (see, for example, Non-Patent Document 1, Non-Patent Document 2, and Patent Document 1) has been proposed. However, the dichroic dyes described in these documents form a lyotropic liquid crystal phase in a solvent such as water or alcohol, and align the dichroic dye by an external field such as an alignment substrate, a flow field, an electric field, or a magnetic field. Therefore, since it has a function as a polarizing plate, it has a disadvantage of being inferior in water resistance and moisture resistance.

On the other hand, in order to improve those drawbacks, it has been proposed to bond a protective film (see, for example, Patent Document 2), but there is also a problem that the polarizing plate itself has a film thickness and water resistance. In order to improve the moisture resistance, a method of immersing the anisotropic film in an aqueous barium chloride solution has also been proposed (see Patent Documents 3 and 4), but depending on the type of compound used in the anisotropic film, It has been found that the problem that the anisotropic film is broken occurs.
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" JP-T 8-511109 JP 2002-090526 A US Pat. No. 6,563,640 US Patent Application Publication No. 2005/0271878

The present invention provides an anisotropic film formed by forming a very thin film containing a lyotropic liquid crystalline compound on a substrate by a wet film forming method and orienting the compound by utilizing intermolecular interaction or the like. A composition for forming a resin layer used on the surface of
In order to protect the anisotropic film by forming a resin layer on the surface of the anisotropic film without excessively increasing the thickness of the anisotropic film and without destroying the anisotropic film It is an object to provide a useful resin composition.

  Moreover, this invention makes it a subject to provide the optical element which has a resin layer formed using this resin composition, and a liquid crystal display element provided with this optical element.

  The present invention is a composition for forming a resin layer on the surface of an anisotropic film layer of a lyotropic liquid crystalline compound formed on a substrate by a wet film forming method, and has 4 or more carbon atoms. , A resin composition comprising a resin solution in which a resin is dissolved in a solvent having a common logarithmic value (log P) of octanol / water partition coefficient (P) of 0.5 or more, and formed on a substrate by a wet film forming method An optical element having a resin layer formed by applying and drying the resin composition on the surface of the anisotropic film layer of the lyotropic liquid crystalline compound, and a liquid crystal display element including the optical element, The gist.

  According to the present invention, a very thin film containing a lyotropic liquid crystalline compound is formed on a substrate by a wet film-forming method in which a solution containing a lyotropic liquid crystalline compound is applied and dried, and intermolecular interaction is utilized. In the anisotropic film layer formed by orienting the lyotropic liquid crystalline compound, the thickness of the anisotropic film layer is not excessively increased and the anisotropic film is not destroyed. A resin composition useful for protecting the anisotropic film layer by forming a resin layer on the surface or imparting water resistance and moisture resistance to the layer, and a resin layer formed using the resin composition And an optical element including the optical element can be provided.

The description of the constituent requirements described below is an example (representative example) of the embodiment of the present invention, and the contents are not specified.
The resin composition of the present invention is a composition for forming a resin layer on the surface of an anisotropic film layer of a lyotropic liquid crystalline compound, which is formed on a substrate by a wet film forming method, and has a carbon number. It consists of a resin solution in which the resin is dissolved in a solvent having a common logarithm value (log P) of octanol / water partition coefficient (P) of 0.5 or more.

  The solvent in the resin composition of the present invention must have 4 or more carbon atoms, and preferably has 5 or more carbon atoms. When the number of carbon atoms is 3 or less, the boiling point is low and the evaporation is fast, so that the handleability and workability as a resin composition are inferior. Moreover, carbon number is 10 or less normally, Preferably it is 8 or less.

  Furthermore, it is essential for the solvent in the present invention that the common logarithmic value (log P) of the octanol / water partition coefficient (P) is 0.5 or more, and preferably 0.7 or more. Usually, it is 5 or less. When logP is less than 0.5, when the resin composition is applied to the surface of the anisotropic film layer and dried as a resin composition, the solvent penetrates the anisotropic film and causes destruction of the film. It becomes. That is, since the anisotropic film described later is usually water-soluble and highly polar, the anisotropic film layer can be formed by relatively lowering the polarity of the solvent of the resin composition used for the resin layer formed on the anisotropic film. It is possible to prevent the destruction of the orientation structure. The octanol / water partition coefficient (P) can be determined according to JIS Z7260-107, and the larger the value, the lower the polarity.

  In the present invention, specific examples of the solvent used include the common logarithmic value (log P) of the octanol / water partition coefficient (P) in parentheses, for example, methyl ethyl ketone (0.7), methyl isobutyl. Ketones such as ketone (1.2) and cyclohexanone (1.4), aromatic hydrocarbons such as toluene (2.3) and xylene (3.0), hexane (3.0), cyclohexane (2. Typical examples thereof include aliphatic hydrocarbons such as 5) and esters such as isopropyl acetate (0.5) and butyl acetate (1.2). A solvent may be used alone or in combination of two or more. When using 2 or more types, the said log P of all the solvents is 0.5 or more.

  The resin in the resin composition of the present invention is basically not particularly limited as long as it is soluble in the solvent, but preferably has transparency, and in particular, an amorphous resin. Is particularly preferred.

  In the present invention, specific examples of the resin used include polyvinyl acetal resins such as polyvinyl formal, polyvinyl butyral, vinyl butyral-vinyl alcohol-vinyl acetate copolymer, and acrylic resins such as polymethyl methacrylate, A typical example is a solubilized polyimide resin such as a polymer represented by the following structural formula. In the resin composition of the present invention, the resin may be used alone or in combination of two or more.

The molecular weight of the resin is usually 3000 or more, preferably 5000 or more, usually 1 million or less, preferably 100,000 or less in terms of weight average molecular weight.
Further, the concentration of the resin in the resin composition of the present invention is preferably 0.1% by weight or more, more preferably 1% by weight or more, and more preferably 5% by weight or more from the viewpoint of forming a uniform coating film without defects. Particularly preferred is 50% by weight or less, and more preferred is 30% by weight or less.

  The resin composition of the present invention may contain an additive such as a surfactant, if necessary, in addition to the solvent and the resin.

  By using a resin solution in which the resin is dissolved in a solvent having a carbon number of 4 or more and a common logarithmic value (log P) of the octanol / water partition coefficient (P) of 0.5 or more as the resin composition, The reason for the effect of the present invention is presumed to be as follows.

  The resin composition of the present invention is for forming a resin layer on the surface of an anisotropic film layer of a lyotropic liquid crystalline compound formed on a substrate by a wet film forming method.

  Here, examples of the substrate include glass and a film of resin such as triacetate, acrylic, polyester, triacetylcellulose, or urethane. In addition, in order to control the orientation direction of the lyotropic liquid crystalline compound on the surface of these base materials, “Liquid Crystal Handbook” (Maruzen Co., Ltd., issued on October 30, 2000), pages 226 to 239, etc. are known. The orientation processing layer may be given by this method.

The lyotropic liquid crystalline compound is a compound that exhibits liquid crystallinity when dissolved in a specific solvent in a specific concentration range (see Maruzen Co., Ltd., Liquid Crystal Handbook 3p, etc.).
Further, the lyotropic liquid crystalline compound used in the present invention is preferably soluble in water or an organic solvent, and particularly preferably water-soluble, for use in the wet film forming method described later. Further preferred are compounds having an inorganic value smaller than the organic value as defined in “Organic Conceptual Diagram—Basics and Applications” (Yoshio Koda, Sankyo Publishing, 1984). Further, in a free state that does not take a salt form, the molecular weight is preferably 200 or more, particularly preferably 300 or more, more preferably 1500 or less, and particularly preferably 1200 or less. . The term “water-soluble” means that the compound dissolves in water at room temperature, usually 0.1% by weight or more, preferably 1% by weight or more.

  The lyotropic liquid crystalline compound may be a dye or a transparent material. In particular, it is preferable to use a lyotropic liquid crystalline dichroic dye. Moreover, only 1 type may be used for a lyotropic liquid crystalline compound, and it may use it in combination of 2 or more type.

Specific examples of the dye include condensed polycyclic and azo dyes, but are not limited thereto. For example, U.S. Pat. No. 2,400,877, Dreyer J. F., Phys. And Colloid Chem., 1948, 52, 808., "The Fixing of Molecular Orientation", Dreyer JF, Journal de Physique, 1969, 4 , 114., "LightPolarization from Films of Lyotropic Nematic Liquid Crystals" and J. Lydon, "Chromonics" in "Handbook of Liquid Crystals Vol.2B: Low Molecular Weight Liquid Crystals II", D. Demus, J. Goodby, GW The dyes described in Gray, HW Spiessm, V. Villed, Willey-VCH, P. 981-1007 (1998) can be used.
Among them, azo dyes are preferable, and among azo dyes, disazo dyes or trisazo dyes are preferable, and disazo dyes whose free acid form is represented by the following general formula (I) are particularly preferable.

[Wherein, D ¹ represents a phenyl group which may have a substituent, a naphthyl group which may have a substituent, or an aromatic heterocyclic group which may have a substituent. A ¹ is
It represents an aromatic hydrocarbon group which may have a substituent. R ₁ and R ₂ each independently represent a hydrogen atom, an alkyl group which may have a substituent, or a phenyl group which may have a substituent. n is 0 or 1. ]

  The disazo dye represented by the general formula (I) is usually a water-soluble dye, and is usually a dichroic dye depending on the number of hydrophilic groups in the molecule. The molecular weight of the dye represented by the formula (I) is usually 450 or more, usually 1500 or less, preferably 1100 or less in the form of a free acid.

In the general formula (I), D ¹ is preferably a phenyl group which may have a substituent, or a naphthyl group which may have a substituent, and may have a substituent. A phenyl group is particularly preferred in terms of both liquid crystallinity and solubility.

When D ¹ is a phenyl group, examples of the substituent that the phenyl group may have include a hydrophilic group introduced to increase the solubility of the dye and an electron donating property introduced to adjust the color tone. Group and electron withdrawing group are preferred. Specifically, a methyl group, an ethyl group, an n-propyl group, a hydroxyethyl group, a 1,2-dihydroxypropyl group and the like which may be substituted, preferably an alkyl group having 1 to 4 carbon atoms; a methoxy group, An ethoxy group, an n-propoxy group, an n-butoxy group, a hydroxyethoxy group, a 1,2-dihydroxypropoxy group and the like, preferably an alkoxy group having 1 to 4 carbon atoms; a methylamino group, an ethylamino group Group, propylamino group, dimethylamino group and the like, preferably an alkylamino group substituted with an alkyl group having 1 to 4 carbon atoms; phenylamino group; acetyl group, benzoyl group and the like, preferably 2 to 7 carbon atoms An acylamino group substituted with an acyl group; a substituted carbamoyl group such as a phenylaminocarbonyl group or a naphthylaminocarbonyl group; Group; a sulfo group, a hydroxyl group, a cyano group and the like. Of these substituents, a sulfo group, a hydroxyl group, and a carboxy group are preferable. The alkyl group, alkoxy group, phenyl group, and naphthyl group in the above substituents may further have a substituent such as a hydroxyl group, a sulfo group, or an alkoxy group. Moreover, the phenyl group may have 1 to 5 of these substituents, and preferably has 1 to 2 of these substituents.

In addition, when D ¹ is a naphthyl group, the naphthyl group may have a substituent which may be a hydrophilic group introduced to enhance solubility or an electron donor introduced to adjust the color tone. And an electron withdrawing group are preferable. Specifically, the same group as the substituent that the phenyl group may have, for example, preferably an alkyl group having 1 to 4 carbon atoms; preferably an alkoxy group having 1 to 4 carbon atoms; preferably 1 to 4 carbon atoms An alkylamino group substituted with an alkyl group; a phenylamino group; an acylamino group preferably substituted with an acyl group having 2 to 7 carbon atoms; a carboxy group; a sulfo group; a hydroxyl group; a cyano group. Of these substituents, a sulfo group, a hydroxyl group, and a carboxy group are preferable. Moreover, the naphthyl group may have 1-4 of these substituents, and it is preferable to have 1-2.

Note that when D ¹ is a naphthyl group, 1-naphthyl, 2-naphthyl, or 3-naphthyl but group, 2-naphthyl group, or be 3-naphthyl LCD expression It is more preferable because the concentration is lowered.

In addition, when D ¹ is a 1-naphthyl group, it is preferable that the naphthyl group has a substituent at the 3-position, 4-position, 6-position, or 8-position for liquid crystallinity, and particularly a sulfo group. It preferably has a carboxy group or a cyano group. In the formula (I), when D ¹ is a 3,6-disulfo-8-hydroxynaphthyl group, R ₁ and R ₂ are not hydrogen atoms and n = 0. Further, when D ¹ is a 2-naphthyl group, 1-position of the naphthyl group, 3, 4, 6-position, or that preferably for liquid crystallinity expression having a substituent at the 8-position, In particular, it preferably has a substituent at the 1-position or 4-position, and particularly preferably has a sulfo group. When D ¹ is a 3-naphthyl group, it preferably has a substituent at the 6-position of the naphthyl group because of liquid crystallinity, and particularly preferably has a sulfo group.

In addition, when D ¹ is an aromatic heterocyclic group, examples of the hetero atom of the aromatic heterocyclic group include a nitrogen atom and a sulfur atom. An aromatic heterocyclic group having a nitrogen atom exhibits liquid crystallinity. It is preferable because of a decrease in concentration. Specific examples of the aromatic heterocyclic group include a pyridyl group, a quinolyl group, a thiazolyl group, a benzothiazolyl group, and a pyridyl group is preferable.

  In addition, examples of the substituent that the aromatic heterocyclic group may have include a hydrophilic group that is introduced to enhance solubility, and an electron-donating group and an electron-withdrawing group that are introduced to adjust the color tone. Is preferred. Specifically, preferably an alkyl group having 1 to 4 carbon atoms; preferably an alkoxy group having 1 to 4 carbon atoms; an alkylamino group substituted with an alkyl group having 1 to 4 carbon atoms; a phenylamino group; preferably Includes an acylamino group substituted with an acyl group having 2 to 7 carbon atoms; a carboxy group; a sulfo group; a cyano group, and the like. Of these substituents, a sulfo group and a carboxy group are preferable. The aromatic heterocyclic group may have 1 to 4 of these substituents, and preferably 1 to 2 of these substituents.

In the general formula (I), specific examples of the aromatic hydrocarbon group represented by A ¹ include a phenylene group and a naphthylene group. The phenylene group is preferably a 1,4-phenylene group, and the naphthylene group is preferably a 1,4-naphthylene group in order to exhibit the above interaction.

If A ¹ is a phenylene group, the substituent which the phenylene group may have, the less polar group, or point group having a hydrogen bond of the associative improved by interaction in order to form lyotropic liquid crystal Is preferable. Specifically, a methyl group, an ethyl group, an n-propyl group, a hydroxyethyl group, a 1,2-dihydroxypropyl group and the like which may be substituted, preferably an alkyl group having 1 to 4 carbon atoms; a methoxy group, An ethoxy group, an n-propoxy group, an n-butoxy group, a hydroxyethoxy group, a 1,2-dihydroxypropoxy group and the like may be substituted, preferably an alkoxy group having 1 to 4 carbon atoms; an acetyl group, a benzoyl group, and the like Preferably an acylamino group substituted with an acyl group having 2 to 7 carbon atoms. In addition, the alkyl group and alkoxy group in the above substituents may further have substituents such as these substituents and hydroxy groups. The phenylene group may have 1 to 4 of these substituents, and preferably 1 to 2 of these substituents.

When A ¹ is a naphthylene group, the naphthylene group may have a substituent such as a methoxy group, an ethoxy group, a hydroxyethoxy group, or a 1,2-dihydroxypropoxy group, preferably carbon. An alkoxy group of 1 to 4 groups, a hydroxyl group, a sulfo group, and the like are preferable from the viewpoint of improving the associative property by interaction in forming a lyotropic liquid crystal. The alkoxy group in the above substituents may further have a substituent such as these substituents and hydroxy groups. Moreover, the naphthylene group may have 1-4 of these substituents, and it is preferable to have 1-2.

In the general formula (I), examples of the alkyl group represented by R ₁ and R ₂ include a methyl group and an ethyl group, preferably an alkyl group having 1 to 4 carbon atoms, and may have an alkyl group and a phenyl group. Examples of the substituent include a hydroxy group, a carboxy group, and a sulfo group. Of these R ₁ and R ₂ , at least one is particularly preferably a hydrogen atom.

  The dye represented by the general formula (I) can usually form a high lyotropic liquid crystal state with a black color tone. Therefore, it is suitable as a dye for an anisotropic film formed by a wet film-forming method, and also has a low wavelength dispersion and a high dichroic ratio. Therefore, an anisotropic film (anisotropic dye film) having high polarization characteristics can be obtained.

  In the present invention, the dye may be used in the form of a free acid as represented by the general formula (I), or a part of the acid group may have 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, the dye is acidified in the form of a free acid, and then dyed with an alkaline solution having a desired counter ion (for example, an aqueous lithium hydroxide solution). A method of neutralizing acidic groups and 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) 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 cation exchange resin, and the dye is acidified in the form of a free acid, and then an alkali solution having a desired counter ion (for example, an aqueous lithium hydroxide solution) ) To neutralize the acidic group of the dye and perform salt exchange.
4) A method of performing salt exchange by allowing an aqueous solution of a dye obtained in a salt form to act on a strongly acidic cation exchange resin previously treated with an alkaline solution having a desired counter ion (for example, an aqueous lithium hydroxide solution).

  Examples of the salt type include salts of alkali metals such as Na, Li and K, ammonium salts which may be substituted with alkyl groups or hydroxyalkyl groups, and organic amine salts. Examples of the organic amine include a lower alkyl amine having 1 to 6 carbon atoms, a hydroxy substituted lower alkyl amine having 1 to 6 carbon atoms, a carboxy substituted lower alkyl amine having 1 to 6 carbon atoms, and the like. 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, specific examples of the dye represented by the general formula (I) in the form of a free acid include, for example, dyes having the structures shown in the following (1) to (29), but are not limited thereto. Is not to be done.

The azo dye represented by the general formula (I) can be produced according to a method known per se. For example, the dye No. The pigment represented by (1) can be produced by the following steps (A) and (B).
(A) A conventional method using 3-aminobenzenesulfonic acid (methanilic acid) and 8-amino-2-naphthalenesulfonic acid (1,7-clebic acid) [for example, “New dye chemistry” by Yutaka Hosoda (Showa 48 The monoazo compound is produced through a diazotization and a coupling step according to the publication on December 21, published by Gihodo, page 396, page 409].
(B) The obtained monoazo compound is similarly 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. (1) is obtained.

The obtained dye may be subjected to purification treatment as necessary.
Moreover, as a transparent material, the following lyotropic liquid crystalline compounds, such as A-1 to A-21, etc. are mentioned, for example. The transparent material refers to a material having a visible light transmission density of 0.2 or less when a film having a thickness of 0.5 μm is formed using the transparent material.
The following compounds A-1 to A-21 and B-1 to B-7 are both described in which the acidic group is in the salt form and in the free acid form. However, the acidic group may be a salt type or a free acid type. Specific examples of the salt type are the same as those in the case where the acidic group of the dye is a salt type.

  Other transparent materials include the following compounds B-1 to B-7. These B-1 to B-7 compounds are preferable because they can be easily aligned by interacting with the lyotropic liquid crystalline compound when used in combination with the lyotropic liquid crystalline compound such as the transparent material.

In addition, only 1 type may be used for a transparent material and it may use it in combination of 2 or more type.
In the present invention, the anisotropic film layer is obtained by depositing the anisotropic film composition containing the lyotropic liquid crystalline compound and the solvent on the substrate by a wet film forming method. Usually, the composition is applied on a substrate and dried to form a very thin film containing a lyotropic liquid crystalline compound, and the lyotropic liquid crystalline compound is aligned by utilizing intermolecular interaction or the like. Is done.

In the composition for anisotropic films, the lyotropic liquid crystalline compound may be used alone or in combination of two or more.
For example, when using the said pigment | dye as a lyotropic liquid crystalline compound, you may mix and use another pigment | dye for the composition for anisotropic films | membranes.

Here, as a preferable example of the other pigment to be mixed, for example, 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. DirectRed 83, C.I. I. Direct Red 89, C.I. I. Aci
d Red 37, C.I. I. DirectViolet
9, C.I. I. Direct Violet 35, C.I. I. Direct Violet 4
8, C.I. I. Direct Violet 57, C.I. I. Direct Blue1, C
. I. Direct Blue 67, C.I. I. Direct Blue 83, C.I. I. DirectBlue 90, C.I. I. Direct Green 42, C.I. I. Dire
ctGreen 51, C.I. I. Direct Green 59 etc. are mentioned.

  As the solvent used in the anisotropic film composition, 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 and isopropyl alcohol, glycols such as ethylene glycol and diethylene glycol, and cellosolves such as methyl cellosolve and ethyl cellosolve. It can also be used as the above mixed solvent.

  The concentration of the lyotropic liquid crystalline compound in the anisotropic film composition depends on the solubility of the lyotropic liquid crystalline compound and the concentration of the associated state such as the lyotropic liquid crystal state, but is preferably 0.1 wt. % Or more, more preferably 1% by weight or more, preferably 50% by weight or less, more preferably 30% by weight or less. If the compound concentration is too low, sufficient anisotropy (dichroism in the case of a dye) cannot be obtained in the anisotropic film, and if it is too high, the compound may be precipitated.

  In addition, in order to improve the wettability to a base material, applicability | paintability, etc., additives, such as surfactant, may be mix | blended with the composition for anisotropic films as needed. As the surfactant, any of anionic, cationic and nonionic properties can be used. The concentration of the additive is sufficient to obtain the desired effect, and is an amount that does not inhibit the molecular orientation of the lyotropic liquid crystalline compound. 0.5 wt% or less is preferable.

  In addition, for the purpose of suppressing instability such as salt formation and aggregation of the compound in the composition for anisotropic film, generally known pH adjusters such as acid and alkali are mixed with the constituent components. The pH may be adjusted by adding either before or after.

  The composition for anisotropic film has two or more groups selected from the group consisting of an acidic group, a basic group, and a neutral group, and at least one of the two or more groups is It is also preferable to add a compound that is a basic group.

  Here, an acidic group and a basic group are functional groups having a pka of less than 7 and 7 or more, respectively, in an aqueous solution containing 0.1 to 3 mol / dm of an inert supporting electrolyte. A neutral group is one having no dissociation constant.

  Examples of the acidic group include a sulfo group, a carboxyl group, and a phosphoric acid group. As the basic group, amino group, sulfonium group, pyrrole group, 3-pyrroline group, pyrrolidine group, pyrazole group, 2-pyrazolin group, pyrazolidine group, imidazole group, 1,2,3-triazole group, 1,2, 4-triazole group, pyridine group, pyridazine group, piperidine group, pyrazine group, piperazine group, pyrimidine group, triazine group and the like can be mentioned. Examples of the neutral group include a hydroxyl group, an amine oxide group, a sulfoxide group, and a phosphine oxide group. These groups may further have a substituent as long as they do not greatly change the characteristics of the composition for an anisotropic film in the present invention.

Some or all of these acidic groups and basic groups may have a salt form. Examples of the salt type of the basic group include salts of inorganic acids such as hydrochloric acid and sulfuric acid, and salts of organic acids such as acetic acid and formic acid. Examples of the salt type of the acidic group include salts of alkali metals such as Na, Li and K, ammonium salts which may be substituted with alkyl groups or hydroxyalkyl groups, and salts of organic amines. . In the case of these salt types, the type is not limited to one type, and a plurality of types may be mixed.

  From the viewpoints of molecular orientation, cohesiveness and the like, the basic group of the compound may be 1 or more, preferably 2 or more, 5 or less, and more preferably 4 or less. In addition, when this compound does not have a neutral group and an acidic group but has only a basic group, the number of basic groups is preferably 3 or more, preferably 5 or less, and more preferably 4 or less. . Further, when the compound has an acidic group, the acidic group may be 1 or more, preferably 4 or less, more preferably 3 or less. The relative ratio of the number of basic groups to acidic groups in the compound is preferably 1.3 or more, and more preferably 4 or less. Further, when the compound has a neutral group, the neutral group may be 1 or more, and the number is not particularly limited, but is usually 8 or less, preferably 6 or less. When the compound has two or more basic groups, acidic groups, and neutral groups, the two or more groups may be the same group or different groups.

  The molecular weight of the compound is usually preferably 60 or more, 75 or more, more preferably 100 or more, particularly preferably 140 or more, 300 or less, further preferably 250 or less, and particularly preferably 200 or less. The compound is preferably a compound having 1 or more carbon atoms, more preferably 3 or more, particularly preferably 6 or more, preferably 15 or less, more preferably 12 or less, and particularly preferably 10 or less. .

  The compound may be a chain compound or a cyclic compound. Specifically, amines are preferable as these compounds, and amino acids, betaines, hydroxyamines, and cyclic compounds having a basic group are particularly preferable.

  The amino acids are classified into neutral amino acids, acidic amino acids, and basic amino acids based on the number and nature of acidic groups and basic groups. Specific examples of the neutral amino acids include glycine, alanine, valine, and leucine. , Isoleucine, phenylalanine, tyrosine, tryptophan, serine, threonine, proline, 4-hydroxyproline, cysteine, cystine, methionine, asparagine, glutamine, β-alanine, citrulline, creatine, kynurenine, etc. , Asparagine, 4-hydroxyproline and β-alanine are preferred. Specific examples of acidic amino acids include aspartic acid and glutamic acid. Among these, aspartic acid and glutamic acid are particularly preferable. Specific examples of basic amino acids include lysine, arginine, histidine and the like. The molecular weight of these amino acids is usually 60 or more, preferably 75 or more, and usually 300 or less, preferably 250 or less. If the molecular weight of amino acids is too large, the molecular size may be large, which may disturb the molecular orientation of the lyotropic liquid crystalline compound. Conversely, if the molecular weight is too small, the molecular orientation fixing effect of the lyotropic liquid crystalline compound may not be sufficiently exhibited. .

  The betaines include carboxyalkyltrialkylammonium hydroxide, carboxyalkylpyridinium hydroxide, sulfoalkyltrialkylammonium hydroxide, sulfoalkylpyridinium hydroxide, phosphoalkyltrialkylammonium hydroxide, phospho Examples thereof include alkylpyridinium hydroxides and derivatives of these compounds. Among these, carboxymethyltrimethylammonium hydroxide and sulfopropylpyridinium hydroxide are preferable. The molecular weight of these betaines is usually 60 or more, preferably 75 or more, and usually 300 or less, preferably 250 or less. If the molecular weight of the betaines is too large, the molecular size may be large and the molecular orientation of the lyotropic liquid crystalline compound may be disturbed. Conversely, if the molecular weight is too small, the molecular orientation fixing effect of the lyotropic liquid crystalline compound may not be sufficiently exhibited. .

Examples of the hydroxyamines include aminoalkyl alcohols, diaminoalkyl alcohols, aminoalkyl diols, diaminoalkyl diols and the like. Of these, aminopropane diol is preferred. The molecular weight of these hydroxyamines is usually 60 or more, preferably 75 or more, and usually 300 or less, preferably 250 or less. If the molecular weight of the hydroxyamines is too large, the molecular size may be large, which may disturb the molecular orientation of the lyotropic liquid crystalline compound. On the other hand, if the molecular weight is too small, the molecular orientation fixing effect of the lyotropic liquid crystalline compound may not be sufficiently exhibited. is there.

  In addition, cyclic compounds having basicity include aminopyridine, diaminopyridine, triaminopyridine, aminopyridazine, diaminopyridazine, triaminopyridazine, aminopyrimidine, diaminopyrimidine, triaminopyrimidine, aminopyrazine, diaminopyrazine, triamine. Examples include aminopyrazine, aminotriazine, diaminotriazine, and triaminotriazine. Among these, triaminopyrimidine is preferable. The molecular weight of the cyclic compound having a basic group is usually 60 or more, preferably 75 or more, and usually 300 or less, preferably 250 or less. If the molecular weight of the cyclic compound having a basic group is too large, the molecular size of the cyclic compound may disturb the molecular orientation of the lyotropic liquid crystalline compound, and conversely if too small, the molecular orientation fixing effect of the lyotropic liquid crystalline compound may be reduced. There is a risk that it will not be fully utilized.

  The above compounds may be used alone or in combination of two or more of the same or different compounds. Further, for example, optical isomers present in amino acids may be used alone or in combination. Moreover, a salt type compound and a free compound may be included, and different salt type compounds may be included.

  Wet deposition methods include Yuji Harasaki's “Coating Engineering” (Asakura Shoten Co., Ltd., published on March 20, 1971) pp. 253-277 and Kunihiro Ichimura, “Creation and Application of Molecular Cooperative Materials” MC Publishing, published on March 3, 1998) 118-149, etc., for example, 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 during application is preferably 0 ° C. or higher and 80 ° C. or lower, and the humidity is preferably about 10% RH or higher and 80% RH or lower. Moreover, the temperature at the time of drying of a coating film becomes like this. Preferably it is 0 degreeC or more and 120 degrees C or less, and humidity is preferably about 10% RH or more and 80% RH or less.

When an anisotropic film layer is formed on a substrate by a wet film formation method, the thickness of the anisotropic film layer after drying is usually preferably 50 nm or more, more preferably 100 nm or more, and preferably 5
It is 0 μm or less, more preferably 20 μm or less, still more preferably 10 μm or less.

  In the present invention, the thin film layer containing the lyotropic liquid crystalline compound obtained by the wet film formation method as described above is an anisotropic film layer by orienting the lyotropic liquid crystalline compound using intermolecular interaction or the like. The Here, as a utilization method such as an intermolecular interaction, a conventional method such as a method of aligning a lyotropic liquid crystalline compound by an external field such as a flow field, an electric field, and a magnetic field in addition to a method of using an alignment-treated substrate. A known method is used.

  The anisotropic film referred to in the present invention is anisotropic in the electromagnetic properties in any two directions selected from a total of three directions in the three-dimensional coordinate system of the film thickness direction and any two orthogonal in-plane directions. It is a film | membrane which has. Examples of the electromagnetic property include optical properties such as absorption and refraction, and electrical properties such as resistance and capacitance. Examples of the film having optical anisotropy such as absorption and refraction include a linearly polarizing film, a circularly polarizing film, a retardation film, and a conductive anisotropic film.

And in this invention, the resin layer is formed by apply | coating and drying the said resin composition on the surface of the formed anisotropic film layer. Here, as a method for coating the surface of the anisotropic film layer, a wet film forming method is used in the same manner as the method for forming the anisotropic film. The drying conditions are the same. The thickness of the resin layer after drying is preferably 20 nm or more, more preferably 50 nm or more, preferably 5 μm or less, and more preferably 2 μm or less. Further, the resin layer may be reinforced by performing a crosslinking operation on the resin layer after drying.

The optical element of the present invention is a resin formed by applying and drying the resin composition of the present invention on the surface of an anisotropic film layer of a lyotropic liquid crystalline compound formed on a substrate by a wet film forming method. It has a layer. As an optical element, an anisotropic film can be used as a polarizing element or a retardation element.
Thus, the optical element having the resin layer formed using the resin composition of the present invention does not cause a problem of film thickness, and does not involve destruction of the anisotropic film during the formation of the resin layer, As a result, the anisotropic film has anisotropy such as a high dichroic ratio of, for example, preferably 5 or more, more preferably 10 or more, particularly preferably 15 or more, and water resistance or moisture resistance as an optical element. In addition, it is expected to be applied to a wide range of uses as a liquid crystal display element, an organic electroluminescence display element and the like.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist.
<Example of preparation of composition for anisotropic film>
A monoazo compound is produced from 4-aminobenzonitrile and 8-amino-2-naphthalenesulfonic acid through a diazotization and coupling reaction according to a conventional method, and then the resulting monoazo compound is diazotized according to a conventional method. , 7-amino-1-naphthol-3,6-disulfonic acid was subjected to a coupling reaction and salted out with sodium chloride to obtain a sodium salt of a dichroic azo dye. The obtained aqueous solution of the sodium salt of the dichroic azo dye was passed through an ion exchange resin, neutralized with lithium chloride, evaporated to dryness, and the dichroic azo dye [Exemplary Compound (23)] A powder was obtained. The resulting dichroic azo dye lithium salt powder and Alizarin Red S were added to distilled water so that the respective concentrations would be 21% by weight and 1% by weight, and then dissolved by stirring under heating. An anisotropic film composition was prepared.

Example 1
The polyimide alignment film having a polyimide alignment film with a thickness of about 800 mm formed on the surface of a glass substrate (75 mm × 25 mm, thickness 1.1 mm) is rubbed in advance, and then the anisotropic prepared above An anisotropic film layer having a film thickness of about 2 μm was formed by applying the composition for a conductive film with an applicator (manufactured by Imoto Seisakusho) with a gap of 10 μm and naturally drying. Furthermore, polyvinyl butyral resin (“S-REC BM-S” manufactured by Sekisui Chemical Co., Ltd.) prepared as a resin composition was added to the surface of the anisotropic film layer with toluene (log P = 2.3) / methyl ethyl ketone (log P = 0.7). ) And a solution dissolved in a volume ratio of 1/1 to a concentration of 10% by weight is spin-coated and air-dried to form a transparent polyvinyl butyral resin layer having a thickness of about 1 μm. Thus, a polarizing element was manufactured.

  When the anisotropic film layer of the obtained polarizing element was observed with a polarizing microscope, no defects were generated in the anisotropic film. Furthermore, after dropping a drop of distilled water on the resin layer and removing the distilled water after 30 seconds, the anisotropic film layer was similarly observed with a polarizing microscope, and no defects were generated in the anisotropic film. It was.

(Example 2)
US Pat. No. 5,344,916 from 2,2′-bis (3,4-dicarboxyphenyl) hexafluoropropane and 2,2′-bis (trifluoromethyl) -4,4′-diaminobiphenyl The polyimide was synthesized by the method described in the document, and the solution obtained by dissolving the obtained polyimide in methyl isobutyl ketone (log P = 1.2) so as to have a concentration of 10% by weight was applied by spin coating and allowed to dry naturally. A polarizing element was produced in the same manner as in Example 1 except that a transparent polyimide resin layer having a thickness of about 1 μm was formed.

When the anisotropic film layer of the obtained polarizing element was observed with a polarizing microscope, no defects were generated in the anisotropic film. Furthermore, after dropping a drop of distilled water on the resin layer and removing the distilled water after 30 seconds, the anisotropic film layer was similarly observed with a polarizing microscope, and no defects were generated in the anisotropic film. It was.
(Example 3)
Anisotropy film composition was obtained by dissolving 0.9 g of cromolyn sodium salt (manufactured by Sigma) in 4.1 g of distilled water.

  This anisotropic film composition was applied onto a glass substrate using an applicator (manufactured by Imoto Seisakusho) with a gap of 10 μm, and then dried to obtain a film having a thickness of about 2 μm. When this film is placed between two polarizing plates whose absorption axes are orthogonal to each other so that the coating direction is 45 degrees with respect to the absorption axis, the light from the light source behind the orthogonal polarizing plates is observed. did it. Further, when the coating direction was set to be 0 degree with respect to the absorption axis, the light from the light source behind the polarizing plate in an orthogonal state could not be observed. From these results, it was found that the obtained film was an anisotropic film having optical anisotropy and acting as a retardation element.

Next, on this anisotropic film, a resin solution having a concentration of 12.5% by weight in which acrylic resin (BR-80, manufactured by Mitsubishi Rayon) was dissolved in toluene / methyl ethyl ketone (volume ratio 1/1) was added with a gap of 10 μm. It was applied using an applicator and allowed to dry naturally to form a transparent acrylic resin layer having a thickness of about 1 μm.
When this element was observed with a polarizing microscope, no defects were generated in the anisotropic film. Furthermore, after dropping a drop of distilled water on the resin layer and removing the distilled water after 30 seconds, the optically anisotropic film layer was similarly observed with a polarizing microscope. As a result, some defects were generated in the optically anisotropic film. It wasn't. When this film is placed between two polarizing plates whose absorption axes are orthogonal to each other so that the coating direction is 45 degrees with respect to the absorption axis, the light from the light source behind the orthogonal polarizing plates is observed. As a result, it was found that it was acting as a phase difference element.

(Comparative Example 1)
When the anisotropic film layer produced in the same manner as in Example 1 was dipped in a 10% by weight aqueous barium chloride solution for 10 seconds and pulled up, the anisotropic film was whitened. About the obtained polarizing element, when the anisotropic film layer was observed with the polarization microscope, it was confirmed that many cracks have generate | occur | produced.

(Comparative Example 2)
When the anisotropic film layer produced in the same manner as in Example 1 was dipped in a 10% by weight calcium chloride aqueous solution for 10 seconds and pulled up, the anisotropic film was whitened. About the obtained polarizing element, when the anisotropic film layer was observed with the polarization microscope, it was confirmed that many cracks have generate | occur | produced.

(Comparative Example 3)
A polarizing element was produced in the same manner as in Example 1 except that a resin composition prepared by using N-methylpyrrolidone (log P = −0.3) as a solvent for the resin composition was used. About the obtained polarizing element, when the anisotropic film layer was observed with the polarization microscope, it was confirmed that many cracks have generate | occur | produced in the anisotropic film.

(Comparative Example 4)
A polarizing element was produced in the same manner as in Example 1 except that a resin composition prepared by using isopropyl alcohol (log P = 0.4) as a solvent for the resin composition was used. About the obtained polarizing element, when the anisotropic film layer was observed with the polarization microscope, it was confirmed that many cracks have generate | occur | produced in the anisotropic film.

(Comparative Example 5)
A polarizing element is produced in the same manner as in Example 1 except that a resin composition prepared by using propylene glycol-1-methyl ether-2-acetate (log P = 0.1) as a solvent for the resin composition is used. did. About the obtained polarizing element, when the anisotropic film layer was observed with the polarization microscope, it was confirmed that many cracks have generate | occur | produced in the anisotropic film.

In the optical element of the present invention, when the anisotropic film is used as a polarizing filter or the like for various display elements such as LCD and OLED, the anisotropic film is directly applied to an electrode substrate or the like constituting these display elements. Or a substrate on which the anisotropic film is formed can be used as a constituent member of these display elements.
In addition, the optical element in 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, as well as a film forming process and a composition containing a substrate and a compound. By selection, it can be functionalized as various anisotropic films such as refractive anisotropy and conduction anisotropy, and can be used as various types of optical elements for various purposes.

Claims (5)

  A composition for forming a resin layer on the surface of an anisotropic film layer of a lyotropic liquid crystalline compound formed on a substrate by a wet film-forming method, having 4 or more carbon atoms, octanol / water A resin composition comprising a resin solution in which a resin is dissolved in a solvent having a common logarithmic value (logP) of a partition coefficient (P) of 0.5 or more.   The resin composition according to claim 1, wherein the lyotropic liquid crystalline compound is an azo dye.   The resin composition according to claim 1, wherein the lyotropic liquid crystalline compound is a transparent material.   It forms by apply | coating and drying the resin composition as described in any one of Claims 1-3 on the surface of the anisotropic film layer of the lyotropic liquid crystalline compound formed by the wet film-forming method on the base material. An optical element comprising a resin layer.   A liquid crystal display element comprising the optical element according to claim 4.