JP2000056309A - Liquid crystal alignment layer and liquid crystal display element using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new liquid crystal alignment layer having a alignment thermal stability and a wide visual field angle, which is an extremely thin film having a nanometer-lever thickness and excellent in alignment control power and which can be uniformly and strongly fixed on a substrate and produced with a good producibility, and to provide a liquid crystal display element using the same. SOLUTION: The liquid crystal alignment layer has a liquid crystal regulating power capable of allowing liquid crystal molecules to align in a specified direction and is fixed directly or via an other material layer by -Si-O- bonding on a substrate 1 having an electrode. The liquid crystal alginment layer is comprised of a thin film in the form of a monomolecular layer containing a chemical bonding unit having a specific group of the formula.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal alignment film used for a flat display panel using liquid crystal, a method for manufacturing the same, and a liquid crystal display device using the liquid crystal alignment film.

[0002]

2. Description of the Related Art In general, a color liquid crystal display device comprises a pair of substrates having transparent electrodes arranged in a matrix and a liquid crystal alignment film formed on the transparent electrodes, with a fixed liquid crystal alignment film surface inside. And a liquid crystal is sealed in the gap. More specifically, for example, a first glass substrate on which a pixel electrode and a thin film transistor (TFT) array are formed, a plurality of red, blue, and green color filters are formed, and a common transparent electrode is further formed thereon. A polymer film is formed on each surface of the second glass substrate, and rubbing is performed on the film surface to impart liquid crystal orientation. Next, they are opposed to each other with the coating surface (liquid crystal alignment film surface) inside and a spacer interposed therebetween, and the periphery of the substrate is bonded to form an empty cell (panel structure).

[0003] Twisted nematic (T)
A liquid crystal display device is constructed by injecting and sealing liquid crystal such as N), and furthermore, deflecting plates are disposed on both outer surfaces of the device, and a backlight is disposed outside the first electrode. A display device is configured.

The liquid crystal display device having such a structure is intended to display an arbitrary image by controlling light transmission by changing the alignment state of the liquid crystal by turning on / off a voltage between electrodes by a TFT. . Therefore, the alignment film that regulates the alignment state of the liquid crystal in the light transmission path plays a very important role in determining the display performance.

As a film material of such a liquid crystal alignment film, a polyimide film has been widely used conventionally because of its excellent affinity with liquid crystal, heat resistance, substrate adhesion, and the like. After spin-coating a solution of polyamic acid, which is a precursor polymer of polyimide, in an organic solvent such as xylene on a substrate, baking it to imidize the polyamic acid to form a polyimide film, and the polyimide itself. After spin-coating a solution dissolved in an organic solvent such as DMF (N, N-dimethylformamide), DMAc (dimethylacetamide), butyl cellosolve acetate, N-methyl-2-pyrrolidone on the substrate,
A method of evaporating a solvent to form a film is used.

However, the polyimide film has the following problems and is not sufficiently satisfactory as a liquid crystal alignment film. That is, (1) The production method using a polyamic acid as a precursor substance requires firing at a high temperature of 250 ° C. or more in order to sufficiently perform imidization. Also, in the production method using polyimide itself, since there is no suitable low boiling point solvent for dissolving the polyimide, a considerable temperature is required for removing the solvent. For example, the above-mentioned organic solvents such as DMF, DMAc, butyl cellosolve acetate, and N-methyl-2-pyrrolidone can be used as a solvent for dissolving the polyimide. However, since all solvents have high boiling points (153 ° C., 165 ° C., 192 ° C., and 202 ° C.) and are flammable, it is necessary to evaporate and dry the solvent at a high temperature while considering explosion prevention during film formation. For this reason, the production of the polyimide film requires a special apparatus for heating, and the production cost is accordingly increased. Further, a circuit such as a TFT may be damaged by the heating.

(2) Since polyimide has insufficient film-forming properties, it is difficult to form a thin and uniform film. For this reason, display unevenness due to uneven film thickness occurs, and a thick film acts as an insulating film, so that it is difficult to realize a liquid crystal display element driven at low voltage.

(3) In addition to the above, the following problem occurs in the rubbing operation for imparting orientation.

[0009] If the film has irregularities, the concave portions will not rub, and especially if the panel has a large area, it will not rub uniformly, causing problems such as generation of alignment defects, display unevenness, and display burn-in.

In addition, static electricity is generated on the alignment film, and this static electricity causes a decrease in the function of the TFT.

Further, dust is generated from the rubbing material (such as cotton cloth), and this dust causes display unevenness and changes in the gap between the substrates.

For this reason, various non-contact orientation systems have been proposed for the purpose of solving the above-mentioned problems in the rubbing system.

For example, in Japanese Patent Application Laid-Open No. 5-53118,
There has been proposed a technique in which a layer of a photosensitive composition is formed on a substrate, grooves having a predetermined pattern are formed in the composition layer by exposure and heat treatment, and orientation is imparted by the grooves. However, this technique requires a large amount of light energy for forming the groove. In addition, since it is difficult to form a uniform groove, problems such as display unevenness occur. Also, the alignment regulating force is not sufficient.

In Japanese Patent Application Laid-Open No. 7-72483,
There has been proposed a technique for imparting orientation by irradiating linearly polarized light to a compound layer for forming an alignment film containing polyimide or a polyimide precursor to polymerize polyimide or the like. However, since this technique uses polyimide which is an organic polymer, it cannot solve the problem that a thick film thickness causes an increase in liquid crystal driving voltage. Another problem is that the fixing force of the alignment film to the substrate is not sufficient.

In Japanese Patent Application Laid-Open No. Hei 7-318942, an alignment film having a polymer structure is irradiated with light obliquely to cause a new bond or a decomposition reaction to occur in a molecular chain of the alignment film. Technology has been proposed.
However, this technique also targets an alignment film made of an organic polymer such as polyimide, polyvinyl alcohol, and polystyrene. Therefore, in this technique, the film thickness is large,
The above-mentioned problems, such as a small substrate fixing force, cannot be solved.
In addition, this technique requires that the alignment film be irradiated with light obliquely in order to provide a pretilt angle, but in order to accurately irradiate light obliquely, a highly accurate light irradiation device is required, The production cost rises accordingly.

In addition to the above problems, a liquid crystal display device of a twisted nematic mode or the like has a problem that the viewing angle is narrower than in the prior art. As a method for solving this problem, for example, in Japanese Unexamined Patent Publication No. Hei 5-173135, a method of rubbing an alignment film in a certain direction, coating the relevant portion with a resist, and then rubbing in the opposite direction is repeated. A method for forming a plurality of regions having different alignment directions of liquid crystal has been proposed.

However, in order to form a plurality of sections having different liquid crystal alignment directions in the rubbing method (contact type), a complicated operation of masking and rubbing each divided section must be repeated. For this reason, according to this technique, the production efficiency of the alignment film is greatly reduced, and the problem of generation of dust becomes a more serious problem.

On the other hand, it is also possible to form a plurality of regions in which the alignment directions of the liquid crystal are different by applying each of the above techniques such as Japanese Patent Application Laid-Open No. 5-53118. However, since each of the above techniques has problems such as a large film thickness and insufficient substrate fixing force as described above, even if these techniques are used, it is still impossible to provide a liquid crystal alignment film that is sufficiently satisfactory.

By the way, the present inventors have disclosed in Japanese Patent Laid-Open No. 3-79.
In Japanese Patent Application Publication No. 13 (1994), a technique capable of manufacturing an alignment film having a thickness of nanometer level with high productivity was proposed. This technology is
A monomolecular film obtained by chemically adsorbing a silane-based chemically adsorbed substance (also referred to as a surfactant) on a substrate surface is used as an alignment film. According to this technique, it is possible to easily and efficiently form an extremely thin transparent film bonded and fixed on a substrate, and to provide an alignment film having a certain degree of alignment control force on liquid crystal molecules without rubbing. it can. However, this technique still leaves room for improvement with respect to the thermal stability of the orientation and the strength of the orientation regulating force.

[0020]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems at once, and an object of the present invention is to provide an extremely thin thin film of a nanometer level which can be uniformly and strongly fixed to a substrate. It is another object of the present invention to provide a novel liquid crystal alignment film which is excellent in thermal stability of alignment and alignment regulating force, has a wide viewing angle, and can be manufactured with high productivity, and a liquid crystal display device using such a liquid crystal alignment film.

[0021]

In order to achieve the above object, the liquid crystal alignment film of the present invention is bonded and fixed to the surface of a substrate having electrodes by a -Si-O- bond directly or through another material layer. A liquid crystal alignment film, comprising: a compound bonding unit having a characteristic group represented by the following formula (1).

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The liquid crystal alignment film having the above-mentioned structure may be a monomolecular thin film having a liquid crystal alignment regulating force capable of aligning liquid crystal molecules in a specific direction. In addition, the film thickness can be 0.5 nm or more and less than 10 nm.

When the thin film is a monomolecular thin film, the thickness is extremely small. Therefore, even if it is arranged in the light transmission path, the light transmission is not hindered, and the degree of hindrance of the electric field for driving the liquid crystal is extremely small. Therefore, a liquid crystal display element which is excellent in luminance and can be driven at low voltage can be realized.

Here, an ideal monolayer means a layer in which individual constituent molecules are arranged along the substrate surface and there is no overlapping of molecules, but it is practically impossible to form a complete monolayer. It's not easy. And even if it is not a complete monolayer, the object of the present invention can be sufficiently achieved. Therefore, the “monolayer-like thin film” in the present invention may be any thin film that can be recognized as a substantially monolayer. For example, there may be a part in which multiple molecules are formed by unadsorbed molecules riding on the adsorbed molecules adsorbed on the substrate, and themselves are not directly bonded and fixed to the substrate but are bonded to directly fixed molecules, Furthermore, a plurality of molecules may be connected in a form in which another molecule is further bonded to the molecule that is not directly fixed, and a layer composed of a plurality of molecules may be formed.However, a monolayer thin film according to the present invention includes: A layer may be included in the portion from a plurality of such molecules. In addition, the monomolecular layered thin film in the present invention means a layer having a thickness of about 5 nm or less.

In the liquid crystal alignment film having the above structure, a chemically adsorbed substance having a characteristic group represented by the following chemical formula (2) is formed on the surface of the substrate having the electrodes directly or through another material layer.
It can be chemically adsorbed by i-O-bond.

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Further, in the liquid crystal alignment film having the above structure, the chemically adsorbed substance having the characteristic group represented by the above-mentioned formula (2) is formed on the surface of the substrate having the electrodes directly or through another material layer. The molecules chemically adsorbed by the O-bond and the molecules chemically adsorbed to each other may be cross-linked via a bond of the carbon-carbon double bond portion of the above formula (Formula 2).

Further, the chemisorbed substance having the characteristic group represented by the above formula (Formula 2) in the above structure can be a compound represented by the following formula (Formula 3).

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In the above, A 1 in the above formula (2) is
Those bonded to the 4-position of the benzene ring constituting the chalcone skeleton are preferable.

Further, it is preferable that A1 in the above-mentioned (formula 3) is bonded to the 4-position of the benzene ring constituting the chalcone skeleton, and A2 is bonded to the 4'-position of the benzene ring constituting the chalcone skeleton.

Further, the liquid crystal alignment film of each of the above constitutions can be composed of only one kind of chemical adsorption substance having the characteristic group represented by the above-mentioned (Formula 2). It can also be composed of two types of chemisorbed substances having the characteristic groups represented. Further, it can be composed of one or more kinds of chemisorbed substances having the characteristic group represented by the above-mentioned (Formula 2) and other chemical substances. In any of the embodiments, any of the substances constituting the liquid crystal alignment film (thin film) has a linear alkyl skeleton, a linear siloxane skeleton, or a linear fluoroalkyl skeleton. This is preferable because a simple film can be formed. This is because high orientation can be realized if the film is uniform.

Further, the liquid crystal alignment film of each of the above structures may have a liquid crystal alignment control force for aligning liquid crystal molecules in a certain direction, and may have a liquid crystal alignment control force for aligning liquid crystal molecules in a plurality of different directions. it can. In the case where the liquid crystal molecules are aligned in a plurality of different directions, it is preferable that the liquid crystal alignment direction is different for each of the small sections into which one pixel unit is divided, and more preferably, the small sections are formed in a pattern. When the alignment film has such alignment characteristics,
This is because a liquid crystal display element having a wide viewing angle can be realized.

On the other hand, in the liquid crystal alignment film according to the present invention, a solution containing the chemical adsorbing substance represented by the above formula (3) is brought into contact with at least the substrate surface having electrodes to chemically adsorb the chemical adsorbing substance. Thus, the liquid crystal alignment film can be manufactured by a method for manufacturing a liquid crystal alignment film including a thin film forming step of forming a monomolecular thin film on the substrate and an alignment processing step of performing an alignment process on the thin film.

Here, as the above-mentioned chemisorbing substance, a compound in which A1 is bonded to the 4-position of a benzene ring is preferable.
Further, it is preferable that A1 has a characteristic group represented by the following formula (4) or (formula 5) bonded thereto.

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Further, as A2 in the above (Chemical formula 2),-
(CH2) n -O-, -O- (CH2) n -O-, -C
O- (CH2) n-O- (where each n is an integer of 2 to 14) is preferred.

In the above-mentioned production method, a thin film material composed of one or more kinds of chemisorbing substances having the above-mentioned functional groups can be used. A thin film material may be used in combination with a compound and used. When a thin film material is composed of multiple types of compounds having different chemical and physical properties, the heat resistance of the thin film, the density of the thin film, the alignment regulating force, the solubility in a solvent, the sensitivity to polarized light, the adsorption force to a substrate, etc. are changed. And an alignment film having desired characteristics can be obtained.

In the above manufacturing method, preferably, between the thin film forming step and the alignment treatment step, the substrate surface on which the thin film is formed is washed with a non-aqueous solvent to remove excess thin film material. It is preferable to add a washing step to perform the cleaning. As the non-aqueous solvent for cleaning, an aprotic organic solvent is preferable in terms of detergency, but a mixed solution of an aprotic organic solvent and a protonic organic solvent may be used. If it is a mixed solvent, the dissolving ability for the thin film material can be appropriately adjusted,
Also, the evaporation rate of the solvent can be controlled.

As the orientation treatment in the above production method,
The following drainage drying method and polarized light irradiation method can be exemplified.

The liquid drainage drying method is a method in which a nonaqueous solvent is brought into contact with the substrate surface on which a coating is formed, and then the nonaqueous solvent is drained and dried in a certain direction. According to this method, molecules constituting the thin film can be provisionally oriented. As the solvent used in the draining and drying method, the above-mentioned organic solvent for washing can be suitably used. Therefore, by performing a series of operations of erecting the substrate after cleaning in a certain direction and draining and drying the organic solvent remaining on the substrate surface, cleaning of the substrate surface and provisional orientation with respect to thin film constituent molecules can be performed.

It should be noted that although temporary alignment can provide a certain degree of alignment control force to the liquid crystal molecules, the temporary alignment alone is insufficient in stability against heat and other external stimuli (for example, rubbing). Therefore, it is preferable to perform the polarized light irradiation method after the temporary alignment as described below.

The above-mentioned polarized light irradiation method is a method of irradiating polarized light to a substrate surface on which a thin film is formed. According to this method, molecules constituting the thin film can be chemically bonded (cross-linked) in a specific direction by light energy, and an alignment regulating force capable of aligning liquid crystal molecules can be imparted to the thin film. Since this alignment regulating force is generated when molecules are connected to each other by a chemical bond, it is excellent in thermal stability, chemical stability, and the like.

In applying the polarized light irradiation method, it is preferable to perform irradiation a plurality of times while changing the light intensity and / or the wavelength. For example, in the method of irradiating a plurality of times with low light intensity, the constituent molecules can be chemically bonded to each other without increasing the temperature of the irradiation surface. For example, when the first irradiation is performed using polarized light having a shorter wavelength closer to the absorption peak and the cross-linking reaction is advanced to a certain extent, the polarized light having a longer wavelength than the first irradiation is used. Thus, the constituent molecules can be chemically reacted with each other more uniformly in the photosensitive group portion while suppressing the damage of the molecular structure caused by the above.

In the polarized light irradiation method, the irradiation can be performed a plurality of times while changing the incident angle with respect to the substrate. According to this method, the pretilt angle can be changed.

In the polarized light irradiation method, polarized light irradiation can be performed by using polarized light having different polarization directions for each irradiation and changing the irradiation section for each irradiation. When the thin film is irradiated with polarized light, the polarized light mainly acts on a light-sensitive atom-atom bond portion parallel to the polarization direction to cause a cross-linking reaction at the bond portion. Therefore, when polarized light having a different polarization direction is used for each irradiation and irradiation is performed such that the irradiation section changes for each irradiation, a plurality of sections having different bonding directions between molecules can be formed. In this method, preferably, the section is made smaller than one pixel unit. In this manner, pixel units having a plurality of different alignment directions can be formed. By using such a multi-domain liquid crystal alignment film, a liquid crystal display element having a wide viewing angle can be realized.

In the above-mentioned polarized light irradiation method, it is preferable to comprehensively control the light intensity, the wavelength, the number of times of irradiation, the incident angle of light on the substrate, and the irradiation pattern. When these elements are suitably controlled, an alignment film having desired alignment characteristics can be manufactured.

Further, as the alignment treatment in the above-described manufacturing method, a method of temporarily aligning by a draining-drying method, and then irradiating polarized light to realign can be adopted. According to this method, desired alignment characteristics (alignment direction, alignment regulating force, pretilt angle, etc.) can be reliably and stably provided.

Here, when the above method of irradiating the polarized light after the temporary alignment is adopted, the polarization direction of the polarized light and the temporary alignment direction (draining and drying direction) do not completely intersect at 90 ° but are slightly crossed. , Preferably several degrees or more. This is because, when the polarized light is irradiated in a state where the temporary orientation direction and the polarization direction are orthogonal to each other, there is a possibility that each of the constituent molecules may be randomly oriented in two directions.

Irradiation with polarized light after the temporary alignment results in an alignment film having a strong alignment regulating force, the relationship between the polarization direction and the cross-linking direction, and the three factors of the temporary alignment direction, the polarization direction and the cross-linking direction. Although the relationship is not sufficiently clarified, it has been experimentally confirmed that a liquid crystal alignment film having good alignment characteristics can be formed by combining the drainage drying method and the polarized light irradiation method.

As a method of manufacturing a liquid crystal alignment film according to the present invention, a solution containing a chemical adsorbing substance represented by the following formula (3) is brought into contact with at least the substrate surface having electrodes, and the chemical adsorbing material is brought into contact with the substrate surface. Is chemically adsorbed to form a monomolecular thin film on the substrate, and a non-aqueous solvent is brought into contact with the substrate surface on which the thin film is formed, and then the non-aqueous solvent is drained and dried in a certain direction. A temporary alignment step of temporarily aligning the adsorbed molecules, and a realignment step of re-aligning the adsorbed molecules in a specific direction by irradiating the substrate surface after the temporary alignment with polarized light and causing a cross-linking reaction between the adsorbed molecules. Wherein the provisional alignment step and the realignment step are repeated two or more times, whereby the liquid crystal alignment control direction is divided into a plurality of pixel units and divided into small patterns. Different It can be adopted a manufacturing method for manufacturing a liquid crystal alignment film of the multi-domain.

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In this manufacturing method, the temporary alignment step and the reorientation step are repeatedly performed. As described above, the method of irradiating polarized light after the temporary alignment allows the crosslinking reaction to proceed efficiently, Can be reoriented. And
The orientation direction of the adsorbed molecules re-oriented by the crosslinking reaction is
It will not be damaged even after draining and drying again. Therefore,
Liquid draining (temporary alignment) → irradiation of polarized light in units of dividing one pixel → liquid draining (temporary alignment) → irradiation of polarized light in other units of dividing one pixel ... It is possible to efficiently manufacture a liquid crystal alignment film in which a plurality of small sections having different alignment directions are formed in one pixel.

A liquid crystal display device according to the present invention using the liquid crystal alignment film described above can have the following configuration.

That is, in a liquid crystal display device having a structure in which at least two substrates having electrodes are opposed to each other with the electrode side inward and a liquid crystal is sealed between the two substrates, The liquid crystal alignment film containing the compound bonding unit having the characteristic group represented by the above formula (1) is -Si-
A liquid crystal display element fixed by O-bonding can be obtained.

Further, in an in-plane switching type liquid crystal display device in which an electrode and a counter electrode are formed on the same substrate, the above formula (1) is applied to the surface of the substrate on which the electrode and the counter electrode are formed. A liquid crystal display element in which a liquid crystal alignment film including a chemical bond unit having a characteristic group is bonded and fixed by a -Si-O- bond can be provided. Note that the method for producing the liquid crystal alignment film including the chemical bond unit having the characteristic group represented by the above-mentioned formula (1) and preferred embodiments are the same as those described in the description of the liquid crystal alignment film. Therefore, although detailed description is omitted here, in the configuration of the liquid crystal display element, it is preferable to use a liquid crystal alignment film composed of a monomolecular thin film because the light transmission and the electric field are not hindered. From the viewpoint of obtaining a viewing angle, it is preferable to use a multi-domain type liquid crystal alignment film in which the liquid crystal alignment direction and the tilt angle are different for each small section obtained by dividing one pixel.

In the liquid crystal alignment film according to the present invention described above, the thin film material may be directly bonded and fixed to the substrate having electrodes by Si—O— bonding, but another material layer may be formed on the electrode surface. It can also be formed and bonded to this material layer by Si—O—bonding. Here, as other material layers, OH groups, COOH groups, NH2 groups, NH
And a layer having a hydrophilic group such as an SH group. Examples of such a material layer include a SiO2 layer and a TiO2 layer.

[0054]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A more detailed embodiment of the liquid crystal alignment film of the present invention will be described below. A typical form of the liquid crystal alignment film of the present invention is a monomolecular thin film containing a compound bonding unit having a characteristic group represented by the above-mentioned (Formula 1), and a liquid crystal capable of aligning liquid crystal molecules in a specific direction. It is a liquid crystal alignment film having an alignment regulating force. Such a liquid crystal thin film is formed by applying a chemically adsorbed substance having a characteristic group represented by the above formula (2) to the surface of a substrate having electrodes directly or through another substance layer by -Si-O- bonding. Chemisorption,
And chemically adsorbed molecules are formed by cross-linking through mutual bonding of carbon-carbon double bonds of the above formula (Formula 2). A method of dissolving a thin film material containing a chemisorbing substance having a characteristic group represented by Formula 2 in a non-aqueous solvent, bringing the thin film material into contact with the substrate surface, and irradiating ultraviolet light or far ultraviolet light is used.

By the way, compounds having a chalcone skeleton generally have high photoreactivity, and in particular, the chalcone derivative represented by the above formula (Formula 2) in which a specific substituent is bonded to two benzene rings is extremely low. It has high photoreactivity and chemisorption. Therefore, according to the above-mentioned structure using the chemical adsorption substance of the above formula (2), a monomolecular layer-like thin film chemically adsorbed on the substrate surface can be easily formed. By irradiating the thin film with light, an intermolecular crosslinking reaction can be easily caused. The thin film (alignment film) obtained by chemically adsorbing the chemically adsorbed substance of the formula (2) on the substrate surface is strongly bonded and fixed to the substrate by the chemical adsorption, and thus has excellent adhesion. Further, since the individual adsorbed molecules are extremely thin films arranged along the surface of the substrate, and since this film is not made of an organic polymer substance, it does not hinder light transmission and does not act as an electric resistance film. Further, it can exert a strong alignment regulating force on the liquid crystal molecules, and is excellent in thermal stability. Therefore, the intended object of the present invention can be sufficiently achieved.

The substituent A1 in the above structure is preferably bonded to the 4-position of the benzene ring, but may be bonded to the 2- and 3-positions. 2 'of the other benzene ring
It is preferable that any one of the 3′-position and the 4′-position has a functional group that chemically adsorbs to the substrate, and such a functional group contains a —SiX group as shown in the following formula (3). Groups can be exemplified.

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As the above-mentioned substituent A1, the following substituents are preferred. However, it is not limited to these.

(1) Methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl Group, n-decyl group, n-undecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-nonadecyl group, n-eicosyl And hydrocarbon groups such as phenyl groups.

(2) A hydrocarbon group containing a carbon-carbon double bond or a carbon-carbon triple bond as a part of the hydrocarbon group of the above (1).

(3) The hydrogen of the hydrocarbon group of (1) and (2) is replaced with another functional group (eg, methyl group, halogenated methyl group, hydroxyl group, cyano group, etc.) and / or an atom (eg, Cl, Br, I etc.) substituted functional groups.

(4) Perfluoro-type functional groups of the hydrocarbon groups of the above (1) and (2).

(5) A functional group in which hydrogen bonded to carbon within 8 from the terminal of the hydrocarbon group of (1) and (2) is substituted by fluorine.

(6) C of the hydrocarbon group of the above (1) and (2)
A functional group in which a part of a C bond is substituted by a C—O—C (ether) bond or a C—CO—C— (carbonyl) bond;

(7) An alkoxyl group containing a hydrocarbon group of the above (1) and (2).

(8) C of the hydrocarbon group of the above (1) and (2)
A perfluoro-type functional group in which a part of a C bond is substituted by a C—O—C (ether) bond or a C—CO—C— (carbonyl) bond;

(9) C of the hydrocarbon group in the above (1) and (2)
A functional group in which a part of a C bond is substituted by a C—O—C (ether) bond or a C—CO—C— (carbonyl) bond, and hydrogen bonded to carbon within 8 from the terminal is substituted by fluorine.

(10) An alkoxyl group containing a perfluoro substituent of the hydrocarbon group of the above (1) and (2).

(11) An alkoxyl group containing a functional group in which hydrogen bonded to carbon within 8 from the terminal of the hydrocarbon group of the above (1) and (2) is substituted by fluorine.

(12) A carbonyl group to which a perfluoro substituent of the hydrocarbon group of the above (1) and (2) is bonded.

(13) A carbonyl group bonded to a functional group in which hydrogen bonded to carbon within 8 from the terminal of the hydrocarbon group of the above (1) and (2) is substituted by fluorine.

Of the above substituents, those having a functional group that expands a conjugated structure when bonded to a chalcone skeleton and an electron donating functional group are particularly preferable in practical use. The reason for this is that such a chalcone derivative having a functional group bonded thereto has a light absorption peak wavelength near 365 nm, which is the i-line of an ultrahigh pressure mercury lamp, and is therefore convenient for a cross-linking reaction by light irradiation.

On the other hand, the divalent functional group which connects the -SiX group (X is a halogen or alkoxyl group) and the chalcone skeleton, which are indispensable for chemically adsorbing the above compound on the substrate, include the above-mentioned (1) to (1). The substituent described in the item 13) is preferably a functional group which loses one terminal atom and becomes bivalent. However, it is not limited to these.

The above compound may be synthesized from a chalcone skeleton, or may be synthesized using a chalcone derivative as a starting material. When synthesizing from a chalcone skeleton, a benzaldehyde having a desired functional group to be introduced into the 4-position of the chalcone skeleton and a substance having a benzoyl group are subjected to an aldol condensation reaction (including a subsequent dehydration reaction). Good. On the other hand, in order to obtain a target compound using a chalcone derivative, it is preferable to use a chalcone derivative having a desired functional group to be introduced at the 4-position of the chalcone skeleton at the 4-position. However, it is a matter of course that the present invention is not limited to these synthesis methods.

The thin film (orientation film precursor) according to the present invention comprises:
It can be produced by bringing a solution in which the above-mentioned chemisorbed substance is dissolved in a non-aqueous solvent into contact with at least a substrate having an electrode. Preferably, the substrate having an electrode is immersed in the solution. As the non-aqueous solvent, for example, a non-aqueous organic solvent containing an alkyl group, a fluorocarbon group, a carbon chloride group, or a siloxane group can be used. In addition, using a solution containing another compound together with the above-mentioned chemisorbed substance,
A thin film composed of two or more composite components can also be produced.

The membrane prepared using the above-mentioned chemisorbed substance is
Washing is preferably performed to remove unadsorbed compounds. As the cleaning agent, an aprotic organic solvent is preferable. However, a protic organic solvent may be used, or a mixed solvent obtained by mixing both may be used. According to the method of mixing the aprotic organic solvent and the protic organic solvent, there is an advantage that the ability to dissolve the compound can be appropriately adjusted.

Suitable aprotic organic solvents include chlorine solvents such as chloroform, aromatic solvents such as benzene and toluene, lactone solvents such as γ-butyl lactone, and ester solvents such as ethyl acetate. Alcohol solvents such as methanol and ethanol are suitable as the proton organic solvents. However, it is needless to say that the solvent is not limited to these solvents.

As an alignment treatment method, for example, a method of attaching a solvent to the film surface, draining the solution in a certain direction, and drying is considered. More specifically, the formed substrate is immersed in a solvent tank containing the solvent described above for a certain time so that the liquid surface and the substrate are substantially perpendicular to each other, and then the substrate is substantially perpendicular to the solvent layer. , And a method of drying the solvent in this state, or a method of flowing the solvent from above a substantially vertical substrate and then drying the solvent. According to these methods, the solvent gradually falls downward from the upper end of the wet surface, and the drying proceeds from above to below. This allows the adsorbed molecules to be oriented along the direction of drying, and allows excess molecules (chemically adsorbed substances) not bound to the substrate to be washed away.

In this specification, the orientation by draining and drying is referred to as temporary orientation. Since the temporary alignment is not based on intermolecular bonding, the alignment force is weaker than the method using polarized light irradiation described below.

As another alignment treatment method, a method of irradiating polarized light to the substrate surface on which the thin film is formed can be exemplified.
In this method, by irradiating polarized light, light energy acts on a light-sensitive atom-atom bond portion of a thin film constituent molecule (adsorbed molecule) parallel to the polarization direction to cause a chemical reaction of the portion. , Causing cross-linking reaction between thin film constituent molecules,
This is for giving a liquid crystal alignment regulating force in a certain direction. According to this method, orientation characteristics excellent in thermal stability and the like can be provided.

In the present specification, this orientation method is called re-orientation.

The polarized light used for the above reorientation is preferably a linearly polarized light for intermolecular bonding in a certain direction. As a method for obtaining linearly polarized light, a method for obtaining the light through a commonly used absorption type polarizing plate, a method for obtaining the light through a non-absorption type polarization separation element such as a polarizing beam splitter, or the like can be used. The wavelength of the polarized light may be any wavelength at which the film material causes a photoreaction, and usually, light in the ultraviolet region is used. As the temperature at the time of exposure, a temperature from around room temperature to around 100 ° C. is usually used, but a temperature outside this range may be used. Note that the alignment treatment method applicable to the present invention is not limited to the above.

The properties of the liquid crystal alignment film according to the present invention, such as the pretilt angle and the alignment direction, can be changed by changing the type of the compound constituting the coating within the range specified in the present invention. Can be changed by changing the type of solvent and drying conditions, and in the polarized light irradiation method, it can be changed by changing the irradiation conditions of polarized light. In order to greatly change the pretilt angle, it is particularly effective to change the irradiation condition of the polarized light, for example, the amount of irradiation energy of the polarized light, the irradiation angle, the number of times of irradiation, and the like.

In the liquid crystal display device of the present invention, a nematic liquid crystal, a smectic liquid crystal, a discotic liquid crystal, a ferroelectric liquid crystal and the like can be used, but a nematic liquid crystal is particularly preferably used in view of a molecular shape. As a nematic liquid crystal,
Examples include biphenyl, terphenyl, azoxy, Schiff base, phenylcyclohexane, biphenylcyclohexane, ester, pyrimidine, dioxane, bicyclooctane, and cubane.

[0084]

The specific contents of the present invention will be described below with reference to examples.

(Example 1) First, a chlorosilane-based chemisorbed substance (also referred to as a surfactant) represented by the following formula (7) containing a carbon chain and having a chalcone skeleton and Si at the terminal or a part of the carbon chain. Was synthesized according to the following reaction steps 1 to 3.

Embedded image

Reaction step 1: 4-Methoxybenzaldehyde 14
7 g (1.08 mol), 4-Hydoxyacetophenone 147
g (1.08 mol) and 1.3 L of ethanol were charged into a 5 L reaction kolben, and 2.16 L of a 10% aqueous sodium hydroxide solution was added dropwise at 5 ° C. or lower over 3 hours. After dripping,
It returned to room temperature and stirred for 3 days. The reaction solution was poured into 1.8 L of ice water, 2.5 L of 2N hydrochloric acid was added, and the precipitated crystals were collected by filtration. The obtained crude crystals are separated from isopropyl alcohol (IP
After washing with A) and toluene and drying, 207 g of a purified product (4-Methoxy-4'-hydroxychalcone) was obtained (75% yield). The reaction formula is shown in FIG.

Reaction step 2: 4-Methoxy-
4'-hydroxychalcone 180g (0.709mol), dr
y DMF (N, N-dimethylformamide) 1260m
was charged into a 3 L reaction kolben, and 28.4 g (0.709 mol) of sodium hydride (60%) was added in 40 parts under ice cooling.
Added over a minute. Thereafter, the mixture was heated to room temperature and stirred for 20 hours. Next, 97 g of 6-Chlorohexanol (0.
709 mol) in 20 minutes.
And reacted for 20 hours.

The reaction solution was poured into ice water, the reaction product was extracted with ethyl acetate, washed with water, the solution on the ethyl acetate side was dried over magnesium sulfate, and the ethyl acetate was evaporated.

The obtained crude crystals were purified by a silica gel column (mobile phase: hexane / ethyl acetate = 1: 1) and further recrystallized from ethyl acetate to give 134.4 g of a purified product (4-Me
thoxy-4 '-(6-hydoxyhexyloxy) chalcone) was obtained (yield 53.5%). The reaction formula is shown in FIG.

Reaction step 3: 4-Methoxy- under argon stream
4 '-(6-hydoxyhexyloxy) chalcone 90g (0.245m
ol), 360 g (2.12 mol) of silicon tetrachloride in 1
The reaction mixture was charged into an L reaction kolben, and stirred at room temperature for 2 hours.

Excess silicon tetrachloride was distilled off, and dehydrated hexane was added to the residue to disperse the crystals. The crystals were collected by filtration, dried and dried.
0 g of the desired product (purified product) was obtained (yield: 56.5). The reaction formula is shown in FIG.

The above-mentioned target substance (chemically adsorbed substance) was confirmed to be the compound represented by the above formula (Formula 7) by 1H NMR or the like. Further, when this target product was dissolved in chloroform and the ultraviolet / visible absorption spectrum was measured, no absorption was observed in the visible light region, and absorption was confirmed in the ultraviolet region having a peak at 340 nm.

Next, a liquid crystal alignment film was prepared using the chemically adsorbed substance synthesized above. Hereinafter, the manufacturing method will be sequentially described.

A glass substrate having a transparent electrode made of indium tin oxide on its surface and a SiO 2 layer formed thereon was thoroughly washed and degreased beforehand to form a substrate 1. On the other hand, the chemical adsorption substance was dissolved in a mixed solvent of a sufficiently dehydrated siloxane-based solvent (KF96L, manufactured by Shin-Etsu Chemical Co., Ltd.) and chloroform to prepare a chemical adsorption liquid 2 having a chemical adsorption substance concentration of 1% by weight. This mixed solvent is an aprotic solvent.

Next, as shown in FIG.
The substrate 1 was immersed (or coated) in the chemical adsorption solution 2 for about 1 hour in a dry atmosphere of 0% or less. afterwards,
Immerse in chloroform 3 (washing solution), which is a well-dehydrated aprotic solvent, to wash away the chemical adsorption solution 2,
Thereafter, the substrate 1 was pulled up in a direction parallel to the gravity (upward), drained (FIG. 2), and exposed to air containing moisture while the substrate was standing.

As a result, a dehydrochlorination reaction occurs between the SiCl group of the chemically adsorbed substance (chlorosilane-based surfactant) and the hydroxyl group on the substrate surface, and further reacts with the moisture in the air to form the following (Formula 8) Is produced.

Embedded image

By the above series of treatments, a thin film on a monomolecular layer in which molecules of a chlorosilane-based chemically adsorbed substance (hereinafter referred to as constituent molecules) are fixed (chemically adsorbed) to hydroxyl groups on the substrate surface through siloxane bonds. Was formed. The thickness of this thin film was about 25 nm when the refractive index was 1.45, as measured by a thickness measurement using an ellipsometer. The same operation was performed on the substrate on which the counter electrode was formed to prepare a counter substrate on which a thin film was formed.

Here, in the thin film prepared as described above, one end of the constituent molecule is chemically adsorbed on the substrate surface, and the other end is oriented to some extent along the draining direction. The reason that the constituent molecules are oriented to some extent by the above method is that the substrate is set up in a certain direction and the liquid is dried and dried. Note that the orientation by this method is referred to as temporary orientation.

Next, a polarizing plate 7 (HNP'B; manufactured by Polaroid) is superimposed on the provisionally oriented thin film so that the polarization direction 6 is substantially parallel to the draining direction 5, and a 500 W high-pressure mercury lamp is used. 480 mJ / cm 2 of 365 nm ultraviolet light 8 (light intensity after transmission through a polarizing plate: 2.1 mW / cm 2) (FIG. 3).

The thin film after irradiation with ultraviolet light was subjected to FT-IR
(Fourier transform infrared spectroscopy) was used to examine the anisotropy of the constituent molecules. As a result, the bonding direction between molecules could not be clarified, but there was a difference in IR absorption between the polarization direction and the direction perpendicular thereto, and the IR absorption in the polarization direction was significantly reduced compared to the direction perpendicular thereto. Was. This means that the photosensitive group of the chalcone skeleton was cross-linked by receiving light energy in the polarization direction. When the constituent molecules are cross-linked to each other, the orientation direction of the constituent molecules is fixed in a three-dimensional structure, so that a more stable orientation than the temporary orientation is imparted. FIG. 4 conceptually shows a state in which the constituent molecules are cross-linked. Reference numeral 34 in FIG. 4 is a bridge portion.

Next, the above-prepared substrate 1 and the counter substrate were set to face each other with the alignment film facing each other, and a spacer of 20 μm
And a nematic liquid crystal 9 (ZL
I4792 (manufactured by Merck) was injected to form a liquid crystal cell. The two substrates were arranged such that the draining direction of each substrate was opposite (anti-parallel state).

When the orientation direction of the liquid crystal molecules in this liquid crystal cell was examined using two polarizing plates, it was confirmed that the liquid crystal molecules were oriented along the drain direction. Also,
When the pretilt angle was measured using an optical crystal rotation method, it was confirmed that the pretilt angle was oriented at about 3 ° along the polarization direction with respect to the substrate surface. FIG. 5 schematically shows the orientation of liquid crystal molecules in this liquid crystal cell. 5 is a transparent electrode, 1
1 represents a chemisorption film layer.

Example 2 In Example 2, irradiation of ultraviolet light was performed through a patterned mask to produce a liquid crystal alignment film having different alignment directions in each region. The second embodiment and the first embodiment differ only in the ultraviolet light irradiation conditions, and therefore the description will be made focusing on the ultraviolet light irradiation conditions here.

First, a thin film was formed on a substrate in the same manner as in Example 1, and the constituent molecules were provisionally oriented. Next, a patterned mask was prepared, and this was laminated on a polarizing plate. Then, ultraviolet light having a wavelength of 365 nm was applied to the thin film by 400 to 800 mJ.
/ Cm 2 and a liquid crystal cell was fabricated in the same manner as in Example 1.

With respect to this liquid crystal cell, the alignment characteristics of the liquid crystal were examined using the same method as described above. As a result, the orientation direction of the unmasked portion changed, and it was confirmed that portions having different orientation directions were formed in a pattern. This means that as a result of the change in the orientation direction of only the region irradiated with the polarized light, an orientation region along the temporary orientation direction,
This means that an alignment region along the polarization direction has been formed.

(Embodiment 3) In Embodiment 3, a thin film surface and a polarization direction are measured each time through a mask prepared so that polarized light is irradiated to a small section obtained by dividing one pixel unit into a plurality. A liquid crystal cell was manufactured in the same manner as in Examples 1 and 2, except that the ultraviolet ray irradiation was performed four times while changing the positional relationship.

The alignment characteristics of the liquid crystal of the liquid crystal cell according to Example 3 were examined using the same method as described above. As a result, it was confirmed that a liquid crystal cell with multi-domain alignment was formed in one pixel. Was.

Example 4 As a chemically adsorbed substance (chlorosilane-based surfactant) having a chalcone skeleton and a Si group,
A liquid crystal cell was produced in the same manner as in Example 1 except that the compound represented by the following (Formula 10) was used.

Embedded image

When the alignment state of this liquid crystal cell was examined in the same manner as in Example 1, it was confirmed that the liquid crystal molecules were oriented at a pretilt angle of about 3 degrees with respect to the substrate surface along the polarization direction. Was done.

(Example 5) In Example 5, a transparent electrode 12 made of indium tin oxide was formed on a glass plate (having a hydroxyl group on the surface), and a transparent electrode 12 having a thickness of 50 nm was further formed thereon.
The substrate 2 on which the SiO2 layer 13 was formed was formed, and a thin film 14 was formed on the surface of the substrate 2 by using the chemical adsorption substance shown in the above-mentioned formula (10). In other respects, a liquid crystal cell of Example 5 was manufactured in the same manner as in Example 4 above. FIG. 6 shows a conceptual diagram of this liquid crystal cell.

When the alignment state of the liquid crystal cell was examined by the same method as in Example 1, it was confirmed that the liquid crystal molecules were aligned at a pretilt angle of about 4 degrees with respect to the substrate surface along the polarization direction. Was done.

Example 6 In Example 6, a liquid crystal display device was manufactured using the liquid crystal alignment film as described above. Hereinafter, a manufacturing process of the liquid crystal display device will be described with reference to FIG.

First, as shown in FIG. 7, a first electrode group 21 mounted in a matrix and a T
A second substrate including a first substrate 20 having an FT (Thin Film Transistor) group 22 and a color filter group 25 and a second electrode 26 (counter electrode) placed so as to face the first electrode group. A chemically adsorbed liquid prepared according to the same procedure as in Example 1 was applied on the substrate 24 to produce a similar chemically adsorbed monomolecular film. As a result, the liquid crystal alignment films 23 and 2 re-aligned along the electrode pattern as in the first embodiment.
7 was produced.

Next, the first and second substrates 20 and 24 are aligned so that the electrodes face each other, and a 90 ° twist-oriented cell is formed with a spacer 29 and an adhesive 30 at a gap of 4.5 μm. did. Then, the TN liquid crystal (ZLI4792; manufactured by Merck) 28 is provided on the first and second substrates.
Was injected to form a liquid crystal display element. Further, polarizing plates 31 and 32 were disposed on both outer sides of the element, and a backlight 33 was disposed on the first substrate side to complete a liquid crystal display device.

The tilt angle of the liquid crystal molecules of the above liquid crystal display element was measured by the same method as in Example 1, and was found to be about 5 degrees. In addition, when each transistor was driven using a video signal while irradiating the backlight 33 from the first substrate side of the device, a clear image with excellent luminance was displayed in the direction of arrow A.

(Embodiment 7) The same process as in Embodiment 5 is carried out after a thin film similar to that of Embodiment 5 is prepared, and a checkerboard mask for dividing each pixel into four is superposed on the polarizing plate and exposed. Performed four times. Except for this, the liquid crystal display device of Example 7 was manufactured in the same manner as in Example 6 described above.

When the orientation of liquid crystal molecules of the liquid crystal cell of the liquid crystal display device was examined in the same manner as described above, it was confirmed that four small sections having different orientations were formed in the same pixel in a pattern. Was done. Further, when the viewing angle was visually observed using this apparatus, it was found that the viewing angle was greatly improved as compared with the apparatus of Example 6 in which the orientation direction was fixed.

[Other Matters] In the above embodiment, the chemically adsorbed monomolecular films having the respective orientations were formed on the pair of substrates on which the electrodes were formed, respectively. An adsorption monomolecular film may be formed.
However, in order to enhance the alignment stability, it is preferable to form a chemically adsorbed monomolecular film on both substrates.

In the above embodiment, a chemisorbed substance having a chlorosilane group was used. However, a chemisorbed substance in which an alkoxysilane group or an isocyanatesilane group was introduced in place of the chlorosilane group can be used. A liquid crystal alignment film having excellent regulation force and chemical adsorption force to the substrate can be obtained.

Further, in the above embodiment, chloroform was used as the water-free cleaning solvent. However, the present invention is not limited to this. Any non-aqueous solvent capable of dissolving a chemically adsorbed substance (surfactant) can be used. Any solvent can be used. Examples of such a solvent include a solvent containing a fluorocarbon group, a carbon chloride group, or a siloxane group, more specifically, Freon 113, chloroform, hexamethyldisiloxane, and the like.

In the above embodiment, light of 365 nm from an ultrahigh pressure mercury lamp was used for exposure. However, the present invention is not limited to this. , 25nm, Kr
248 nm light obtained with an F excimer laser can be used. Of these wavelengths, light of 248 nm or 254 nm is easily absorbed by the chemisorbed thin film according to the present invention, and thus is excellent in energy alignment efficiency.

The liquid crystal alignment film according to the present invention contains a chemical bond unit represented by the following chemical formula (9). Strong alignment control power for nematic (TN) type liquid crystal.
Therefore, the present invention can be particularly suitably applied to this type of liquid crystal display device. The chemisorbed substance containing the chemical bond unit represented by the formula (9) is generally dissolved in a non-aqueous organic solvent containing an alkyl group, a fluorocarbon group, a carbon chloride group, or a siloxane group. Therefore, these organic solvents can be suitably used when preparing the chemical adsorption liquid.

Embedded image

In the above embodiment, a liquid crystal display device in which a pair of substrates having electrodes are superposed is described. However, according to the present invention, an alignment film having various alignment characteristics can be formed without performing rubbing. The liquid crystal alignment film of the present invention can be suitably applied to an in-plane (IPS) type liquid crystal display element in which a pair of electrodes is formed only on one substrate.

Further, a thin film can be formed by using a complex chemisorbent mixed with another chemisorbent, for example, octadecyltrichlorosilane, together with the chemisorbent used in the above embodiment. By blending, the pretilt angle and the like can be changed.

[0125]

As described above, according to the present invention,
A much thinner and more uniform alignment film can be produced compared to conventional ones. This alignment film has excellent thermal stability and orientation because the constituent molecules (adsorbed molecules) are cross-linked, and is shared on the substrate surface. It is firmly connected via a bond. Therefore,
According to the present invention, a highly reliable liquid crystal alignment film having excellent display performance can be provided.

Further, according to the production method of the present invention, a desired orientation direction and a pretilt angle can be imparted by a simple drainage drying method or a polarized light irradiation method using far ultraviolet rays or ultraviolet rays. Therefore, a highly reliable liquid crystal alignment film can be manufactured with high productivity.

Further, in the manufacturing method of the present invention, if a method of exposing a polarizing plate to a polarizing plate a plurality of times through a patterned mask after forming the thin film is used, a liquid crystal having a different orientation in each of the small sections divided into the pattern. An alignment film can be manufactured very efficiently. Therefore, according to the manufacturing method of the present invention, a multi-domain type liquid crystal display device having a wide viewing angle can be provided at lower cost.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram for explaining a chemical adsorption step for producing a monomolecular thin film according to the present invention.

FIG. 2 is a conceptual diagram illustrating a step of cleaning a monomolecular thin film according to the present invention.

FIG. 3 is a conceptual diagram of an alignment treatment step for reorienting constituent molecules of a thin film by light irradiation.

FIG. 4 is a conceptual diagram for explaining an orientation state of thin film constituent molecules after light irradiation.

FIG. 5 is a cell cross-sectional view for explaining the liquid crystal cell of Example 1.

FIG. 6 is a cell cross-sectional view for explaining a liquid crystal cell of Example 5.

FIG. 7 is a diagram schematically illustrating a cross section of a liquid crystal display device according to a sixth embodiment.

FIG. 8 is a diagram showing a procedure for synthesizing the chemisorbed substance used in Example 1.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Chemical adsorption liquid 3 Non-aqueous solvent for cleaning 4 Pulling up direction from cleaning liquid 5 Temporarily oriented thin film 6 Polarization direction 7 Polarizing plate 8 Irradiation light 9 Reoriented thin film 10 Transparent electrode 11 Liquid crystal alignment film 12 Transparent electrode 13 SiO2 Layer 14 Liquid crystal alignment film 20 First substrate 21 First electrode group 22 TFT group 23 First liquid crystal alignment film 24 Second substrate 25 Color filter group 26 Second electrode group 27 Second liquid crystal alignment film 28 Liquid crystal 29 Spacer 30 Adhesive 31, 32 Polarizer 33 Backlight 34 Crosslinking

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yukio Nomura 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture F-term in Matsushita Electric Industrial Co., Ltd. (reference) 2H090 HB11Y HB13Y HD14 HD15 KA05 KA14 LA04 MA10 MB14 4H027 BA01 BB03 BC05 4J035 CA071 CA131 LB20

Claims (32)

[Claims] 1. A liquid crystal alignment film fixed and fixed to a surface of a substrate having electrodes by a -Si-O- bond directly or via another material layer, wherein the liquid crystal alignment film has a characteristic group represented by the following chemical formula 1. A liquid crystal alignment film comprising a compound bond unit having the formula: Embedded image 2. The liquid crystal alignment film according to claim 1, wherein the liquid crystal alignment film is a monomolecular layer-like thin film and has a liquid crystal alignment control force capable of aligning liquid crystal molecules in a specific direction. 3. The liquid crystal alignment film according to claim 2, wherein the thickness of the liquid crystal alignment film is 0.5 nm or more and less than 10 nm. 4. The liquid crystal alignment film according to claim 1, wherein a chemically adsorbed substance having a characteristic group represented by the following formula (2) is formed on the surface of the substrate having the electrodes directly or through another material layer. 4. The liquid crystal alignment film according to claim 1, wherein the liquid crystal alignment film is formed by chemical adsorption by bonding. Embedded image 5. The liquid crystal alignment film according to claim 1, wherein the chemically adsorbed substance having the characteristic group represented by the formula (2) is formed on the surface of the substrate having the electrode directly or via another material layer. 4. The method according to claim 1, wherein the molecules chemically adsorbed by the bond and the molecules chemically adsorbed to each other are cross-linked via a bond of the carbon-carbon double bond portion of the formula (2). 5. Liquid crystal alignment film. 6. The liquid crystal alignment film according to claim 4, wherein the chemisorbed substance having the characteristic group represented by the formula (2) is a compound represented by the following formula (3). Embedded image 7. A1 of the formula (2) or (3)
7. The liquid crystal alignment film according to claim 4, which is bonded to the 4-position of the benzene ring constituting the chalcone skeleton. 8. A1 of the formula (2) or (3)
Is bonded to the 4-position of the benzene ring constituting the chalcone skeleton, and A2 is 4 ′ of the benzene ring constituting the chalcone skeleton.
The liquid crystal alignment film according to claim 4, wherein the liquid crystal alignment film is bonded to positions. 9. A1 of the formula (2) or (3)
Is a characteristic group represented by the following (Formula 4) or (Formula 5). Embedded image Embedded image 10. The liquid crystal alignment film according to claim 4, wherein the liquid crystal alignment film is composed of two or more kinds of chemisorbing substances having a characteristic group represented by the above-mentioned (Formula 2) or (Formula 3). Liquid crystal alignment film. 11. The liquid crystal alignment film according to claim 4, wherein the liquid crystal alignment film includes a chemical adsorbing substance having a characteristic group represented by the above-mentioned chemical formula 2 or 3 and a chemical substance other than the above. 10. The liquid crystal alignment film according to 9. 12. The liquid crystal alignment film is composed of a plurality of types of chemical substances, at least one of which is a chemisorption substance having a characteristic group represented by the above formula (2). 10. The liquid crystal alignment film according to claim 4, wherein any one of the chemical substances has a linear alkyl skeleton, a linear siloxane skeleton, or a linear fluoroalkyl skeleton. 13. The liquid crystal alignment film according to claim 1, wherein the liquid crystal alignment film has different alignment control directions for liquid crystal molecules in each of a plurality of small sections obtained by dividing one pixel unit of the alignment film into a pattern. 14. The liquid crystal alignment film according to claim 1, wherein the another material layer is an organic layer or an inorganic layer having a hydrophilic group. 15. A monomolecular layer on the substrate by bringing a solution containing a chemical adsorbent represented by the following formula (3) into contact with at least the surface of the substrate having an electrode to chemically adsorb the chemical adsorbent. A method for producing a liquid crystal alignment film, comprising: a thin film forming step of forming a thin film; and an alignment treatment step of performing an alignment treatment on the thin film. Embedded image 16. A1 in the above formula (3) represents a benzene ring 4 constituting a chalcone basic skeleton shown in the following formula (6).
The method for producing a liquid crystal alignment film according to claim 15, wherein the liquid crystal alignment film is bonded to a position. Embedded image 17. The method for producing a liquid crystal alignment film according to claim 15, wherein A 1 in the formula (3) is represented by the following formula (4) or (formula 5). Embedded image Embedded image 18. The compound of the formula (3) wherein A2 is-(CH2
) N -O- or -O- (CH2) n -O- or-
The method for producing a liquid crystal alignment film according to any one of claims 15 to 17, wherein CO- (CH2) n-O- (where n is an integer of 2 to 14). 19. A cleaning step for cleaning a substrate surface on which a thin film is formed by using a non-aqueous solvent between the thin film forming step and the alignment treatment step, and cleaning an unadsorbed chemically adsorbed substance. A method for producing a liquid crystal alignment film according to claim 15. 20. The non-aqueous solvent in the washing step,
The method for producing a liquid crystal alignment film according to claim 19, wherein the method is an aprotic organic solvent. 21. The non-aqueous solvent in the washing step,
The method for producing a liquid crystal alignment film according to claim 19, wherein the mixed solvent is a mixed solvent obtained by mixing an aprotic organic solvent and a proton organic solvent. 22. The alignment treatment step is a step in which the substrate after cleaning is set in a predetermined direction, and the non-aqueous solvent remaining on the substrate surface is drained and dried to temporarily align the adsorbed molecules. Item 22. The method for producing a liquid crystal alignment film according to any one of Items 15 to 21. 23. The alignment treatment step, wherein the substrate surface on which the thin film is formed is irradiated with polarized light to cause a cross-linking reaction between adsorbed molecules to thereby align liquid crystal molecules in a specific direction. 22. The method for producing a liquid crystal alignment film according to claim 15, which is a step of imparting the following. 24. The alignment treatment step, wherein the substrate after cleaning is set in a certain direction, a non-aqueous solvent remaining on the substrate surface is drained and dried to temporarily align the adsorbed molecules, and then the substrate surface is polarized. By irradiating light and causing a cross-linking reaction between the adsorbed molecules,
22. The method for producing a liquid crystal alignment film according to claim 15, wherein the step is a step of applying an alignment regulating force capable of aligning liquid crystal molecules in a specific direction. 25. The method according to claim 25, wherein the irradiation of the polarized light includes light intensity and / or
25. The method for producing a liquid crystal alignment film according to claim 23, wherein irradiation is performed a plurality of times while changing the wavelength. 26. The method for manufacturing a liquid crystal alignment film according to claim 23, wherein the irradiation of the polarized light is performed a plurality of times while changing an incident angle on the substrate. 27. The liquid crystal according to claim 23, wherein the irradiation of the polarized light is performed by using polarized light having a different polarization direction for each irradiation and changing an irradiation section for each irradiation. A method for manufacturing an alignment film. 28. The irradiation of the polarized light, the light intensity, the wavelength,
25. The method for producing a liquid crystal alignment film according to claim 23, wherein the number of irradiations, the incident angle of light to the substrate, and each element of the irradiation pattern are controlled to cross-link molecules constituting the thin film in a predetermined direction. . 29. A solution containing a chemically adsorbed substance represented by the following formula (3) is brought into contact with at least a surface of a substrate having electrodes, and the chemically adsorbed substance is chemically adsorbed on the substrate surface. A film forming step of forming a monomolecular thin film, and after contacting the non-aqueous solvent with the substrate surface on which the thin film is formed, the non-aqueous solvent is drained and dried in a certain direction,
A temporary alignment step of temporarily aligning the adsorbed molecules, and a realignment step of re-orienting the adsorbed molecules in a specific direction by irradiating the substrate surface after the temporary alignment with polarized light and causing a cross-linking reaction between the adsorbed molecules. A method of manufacturing a liquid crystal alignment film, wherein the above-described temporary alignment step and re-alignment step are repeatedly performed two or more times, so that a liquid crystal alignment regulation direction is different for each of a plurality of pixel-divided small sections. A method for producing a liquid crystal alignment film for producing a domain liquid crystal alignment film. Embedded image 30. A liquid crystal display element having a structure in which at least two substrates having electrodes are opposed to each other with the electrode side inside, and a liquid crystal is sealed between the two substrates. A liquid crystal display device characterized in that a liquid crystal alignment film including a compound bonding unit having a characteristic group represented by the following (Formula 1) is fixedly bonded by a -Si-O- bond. Embedded image 31. An in-plane switching type liquid crystal display device in which an electrode and a counter electrode are formed on the same substrate, wherein the surface of the substrate on which the electrode and the counter electrode are formed has the following formula (1). A liquid crystal display device, wherein a liquid crystal alignment film including a chemical bond unit having the characteristic group shown is bonded and fixed by a -Si-O- bond. Embedded image 32. The liquid crystal alignment film is a monolayer-like thin film capable of aligning liquid crystal molecules in a specific direction, and the monolayer-like thin film has a characteristic group represented by the following formula (2). The chemisorbed substance is chemically adsorbed to the surface of the substrate having the electrode directly or through another material layer by a -Si-O- bond, and the chemically adsorbed molecules form the carbon. 32. The liquid crystal display device according to claim 30, wherein the liquid crystal display device is formed by cross-linking via a bond of a carbon double bond portion. Embedded image