JP2950824B2 - Liquid crystal alignment film, method of manufacturing the same, liquid crystal display device using the same, and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a liquid crystal alignment film, a method for manufacturing the same, a liquid crystal display device using the same, and a method for manufacturing the same. More specifically, the present invention relates to a liquid crystal alignment film used for a flat display panel using a liquid crystal for displaying a television (TV) image, a computer image, and the like, a method of manufacturing the same, a liquid crystal display device using the same, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, the use of liquid crystal display devices capable of color display has been rapidly expanding. However, this device has a structure in which a transparent electrode arranged in a matrix and a liquid crystal alignment film formed on the transparent electrode are used. Are opposed to each other with a certain gap with the 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-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 on which is formed, 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). Liquid crystal such as twisted nematic (TN) is injected into the empty cell and sealed to form a display element. Further, a polarizing plate is disposed on both outer surfaces of the element, and a backlight is disposed outside the first electrode. Thus, a liquid crystal display device as an optical display device is configured.

A liquid crystal display device having such a structure has a TFT
By turning on / off the inter-electrode voltage to change the alignment state of the liquid crystal, light transmission is controlled to display an arbitrary image. 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 the liquid crystal alignment film, polymer materials such as polyimide and precursors thereof such as polyamic acid and polyvinyl alcohol have been widely used.
As a method of manufacturing, for example, a solution obtained by dissolving a polyimide or the like in an organic solvent is applied to a substrate surface using a spin coating method or the like to form a coating, and then the coating surface is rubbed using a felt cloth or the like. Have been.

However, according to this method, coating unevenness and rubbing unevenness occur due to irregularities and steps on the substrate surface, and when the panel area is large (for example, a 14-inch display), coating unevenness and rubbing unevenness are more likely to occur. Also, due to static electricity generated during rubbing, T
There is a problem that the FT is damaged or display unevenness occurs due to dust generated during rubbing.

In order to manufacture a so-called multi-domain type liquid crystal display device using a rubbing method, a complicated process of alternately repeating masking and rubbing must be performed a plurality of times. According to this method of repeating rubbing, the above-mentioned problems such as damage to TFTs and generation of dust become more serious, and since the process is complicated, the production efficiency of the liquid crystal panel is greatly reduced.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal alignment film capable of solving the above-mentioned problems and a method for producing such a liquid crystal alignment film. It is an object to provide a liquid crystal alignment film capable of realizing multi-domain alignment, and a liquid crystal display device having a wide viewing angle using such an alignment film.

[0009]

Means for Solving the Problems A group of the present invention for achieving the above object is constituted as follows.

(1) A monomolecular layer-like thin film formed on the surface of a substrate having electrodes, one end of a molecule constituting the thin film is bonded and fixed to the surface of the substrate, and the molecules are connected to the substrate for each region. A liquid crystal alignment film formed by cross-linking in a state where the long axis tilt and / or alignment direction are different.

In a monomolecular thin film, adsorbates (thin-film constituent molecules) having one end of a molecule bonded to a substrate surface (adsorbent) and the other end oriented in a direction away from the substrate surface are attached to the substrate surface. It has a structure arranged along. In a thin film having such a structure, there is a gap between adjacent individual molecules constituting the thin film, and liquid crystal molecules can enter the gap. At this time, the liquid crystal molecules enter in a form adapted to the shape of the gap. Will be. That is, the liquid crystal molecules enter the gap at an inclination (pretilt angle) or orientation (pretilt orientation) that matches the inclination, orientation, or the like of the adsorbate molecules constituting the gap space with respect to the substrate.
Therefore, by controlling the inclination and the direction of the long axis of the molecules constituting the thin film, the orientation (pretilt angle and pretilt direction) of the liquid crystal molecules can be controlled.

However, a monomolecular thin film composed of a group of constituent molecules having only one end fixed has the effect that the alignment state of the long axis of the molecule easily changes when heat, external force, or the like is applied. Becomes unstable. Here, in the liquid crystal alignment film having the above-described configuration, one end of the constituent molecule is fixed to the substrate, and the molecules are connected to each other at a specific position of the molecular long axis by a cross-linking bond. With such a structure, the molecular orientation is stabilized in a three-dimensional structure. That is,
With the above configuration, the alignment of the liquid crystal molecules can be stably regulated,
In addition, since the thin film is a monomolecular thin film, a liquid crystal alignment film having an excellent alignment regulating force in which each of the constituent molecules contributes to the alignment of the liquid crystal molecules can be obtained.

In the above structure, the inclination and / or orientation of the long axis of molecules constituting the thin film is different for each region of the thin film so that the pretilt angle and the pretilt orientation can be controlled for each region of the alignment film. It is. Therefore, according to the above configuration, a so-called multi-domain liquid crystal alignment film can be realized.

In addition to the above, the liquid crystal alignment film having the above structure is
Since it is formed of a monomolecular thin film, it is extremely thin (on the order of nanometers), and since it is not a polymer film, its insulating properties are small. Therefore, the cell has a very advantageous property that the cell thickness is not increased by the formation of the alignment film, and the alignment film hardly hinders the light transmission and the liquid crystal driving electric field.

A conventional liquid crystal alignment film (for example, a polymer film made of the above-mentioned polyamide) which is formed in a state in which a long main chain is entangled with the liquid crystal alignment film of the present invention,
Since only the surface layer can contribute to the alignment of the liquid crystal, it is difficult to obtain a sufficient alignment regulating force. Further, in a conventional alignment film that imparts orientation by rubbing, the orientation changes or deteriorates when an external stimulus such as heat or rubbing is applied. Further, a polymer film such as polyamide has a problem that it is a thick film and has high electric resistance, which causes a hindrance in light transmission and liquid crystal driving. Therefore, when a polymer film such as polyamide is used, the function and effect of the liquid crystal alignment film having the above configuration cannot be obtained.

Here, the pretilt angle refers to the angle of the long axis of the liquid crystal molecules with respect to the substrate plane, and the pretilt azimuth refers to the direction of the long axis of the liquid crystal molecules on the substrate plane.

The present inventors have confirmed that the pretilt angle and the pretilt direction of the liquid crystal molecules can be changed by changing the inclination and the direction of the long axis of the molecules constituting the thin film. The details of the relationship between the tilt and orientation of the long axis of the molecule and the pretilt angle and pretilt orientation of the liquid crystal molecule (for example, whether or not they match) are not sufficiently clarified.

The liquid crystal alignment film described in the above (1) can be further configured as follows.

That is, each of the regions can be divided into a plurality of patterns corresponding to one pixel. According to this configuration, it is possible to provide a liquid crystal alignment film that realizes multi-domain (including dual domain, the same applies hereinafter).

The thin film is formed by chemisorbing a chemisorbing substance containing a photosensitive group, silicon, and a linear carbon chain or a linear siloxane bonding chain onto the substrate surface. It can be formed by crosslinking at the base. If the photosensitive group and silicon, and a chemisorbed substance containing a linear carbon chain or a linear siloxane bonding chain, can be bonded to the substrate surface via silicon, and the photosensitive group can cross-link molecules with each other, Since the linear carbon chain or the linear siloxane bond chain functions to secure the length of the major axis, it is convenient in terms of imparting chemical adsorption and orientation to the substrate.

Further, the thin film constituent molecules may have silicon at the terminal. When the thin film is composed of a group of molecules bonded to the substrate surface via silicon at the terminal, the thin film is firmly bonded to the substrate and hardly peels off, resulting in excellent durability.

Further, the thin-film constituent molecules may be composed of a plurality of types of molecules having different molecular long axes, and the plurality of types of molecules may be bonded to the substrate surface in a mixed state. In a thin film that is arranged along the substrate surface in a state in which a plurality of types of molecules having different lengths of the molecular long axes are mixed, as a result of combining short molecules with long molecules,
The molecular orientation state is stabilized three-dimensionally. In addition, when the mixing ratio of short molecules and long molecules changes, the state of molecular alignment changes, so that an alignment film having desired alignment characteristics can be formed.

The plurality of types of molecules may have different lengths of linear carbon chains or linear siloxane bonding chains contained in the molecular structure. A molecule having a straight chain is convenient as a molecule that regulates the alignment of the liquid crystal molecules, and the alignment regulating characteristics for the liquid crystal molecules can be changed by changing the length of the straight chain.

(2) The liquid crystal alignment film according to the above (1),
A chemisorption solution containing a silane-based chemisorption substance containing a photosensitive group and a linear carbon chain or a linear siloxane bonding chain, and a non-aqueous organic solvent is brought into contact with a substrate surface having electrodes to perform chemisorption. A thin film forming step of forming a monolayer thin film by chemically adsorbing the chemisorbed molecules in the liquid onto the substrate surface, and after washing the monolayer thin film with a cleaning liquid comprising a non-aqueous organic solvent, in a certain direction A substrate is erected, and the cleaning liquid is drained and dried to temporarily orient the orientation direction of the constituent molecules of the thin film in a certain direction, and a pattern of polarized light having different polarization directions on the temporarily oriented thin film surface. And a cross-linking step of irradiating light to cross-link the constituent molecules in a specific direction.

Each element of the above configuration operates as follows.
First, when a chemisorption solution containing a silane-based chemisorbent and a non-aqueous organic solvent is brought into contact with the electrode surface, a hydrophilic group such as a hydroxyl group present on the electrode surface is attached to a molecule of the silane-based chemisorbate (chemisorbate molecule). ) Is chemically adsorbed to form a monomolecular thin film. When this thin film is washed with a washing solution composed of a non-aqueous organic solvent, unreacted molecules can be removed, and a high-quality monomolecular layer-like thin film having many gaps into which liquid crystal molecules can enter can be formed. This cleaning also acts as a pre-treatment for the subsequent temporary alignment.

Next, the substrate with the thin film containing the cleaning liquid is set up in a certain direction and drained off and dried. The drying proceeds downward from the upper end of the wet surface of the thin film (ie, in the direction of gravity). However, at this time, the molecules constituting the thin film are temporarily oriented in the drying direction. And if it is in a state of temporary orientation,
Since the constituent molecules are more likely to be cross-linked in a certain direction than in the case of non-alignment, the subsequent irradiation of patterned polarized light can efficiently cross-link the molecules constituting the thin film. Therefore, an alignment film having a plurality of patterned cross-linking regions can be manufactured with high productivity.

From the above, according to the manufacturing method of the above configuration,
An alignment film having a plurality of regions having different inclinations and orientations of the constituent molecules of the thin film with respect to the substrate is obtained, and this alignment film has a characteristic that a pretilt angle and a pretilt orientation are different for each of the plurality of regions.

In the manufacturing method of the above (2), the cross-linking step uses the polarized light having a different polarization direction for each irradiation with respect to the thin film surface temporarily oriented in the temporary orientation step, and the irradiation area is changed for each irradiation. Irradiating the polarized light two or more times differently so as to vary the inclination and / or orientation of the thin film constituent molecules with respect to the substrate surface for each of a plurality of divided regions corresponding to one pixel in a pattern. can do.

According to this method, the same operation and effect as described above can be obtained. In this method, the polarized light having a different polarization direction is used for each irradiation, and the irradiation area is changed for each irradiation. Irradiation of polarized light, a multi-domain liquid crystal alignment film in which the inclination and / or the orientation of the thin film constituent molecules with respect to the substrate surface is different for each of a plurality of divided regions corresponding to the pixels in a pattern shape. Can be manufactured.

In the above method (2), in the orientation imparting step, the monomolecular thin film is washed with a washing liquid composed of a non-aqueous organic solvent, and then the substrate is set up in a certain direction to wash the washing liquid. Draining and drying in a certain direction, a first alignment step of temporarily aligning the orientation direction of the thin-film constituent molecules in a certain direction, and polarized light having a polarization direction substantially parallel to the direction of the temporary alignment in the first alignment step. A series of steps including the second alignment step of irradiating is repeated at least twice, and the N-th time (where N
Is an integer of 2 or more), [N-
1) While making the direction of drainage and drying up to the first time different,
The irradiation area on the substrate in the N-th polarization irradiation performed in correspondence with the draining and drying was made different from the irradiation area up to the [N-1] th irradiation, and a plurality of sections corresponding to one pixel were divided into a plurality of patterns. The process may be such that the inclination and / or the orientation of the major axis of the thin film constituting molecule with respect to the substrate surface is different for each divided region.

The first alignment step in this configuration is substantially the same as the temporary alignment step described in the above (2). However, in this configuration, the first alignment step and the thin film temporarily aligned in the first step are performed. It is characterized in that the second step of irradiating polarized light in a direction substantially the same as the temporary alignment direction is repeated. The technical significance of this configuration is as follows.

When the polarized light is irradiated after the temporary alignment as described above, the molecules are easily cross-linked in a specific direction. However, since the polarized light parallel to the temporary alignment direction is irradiated here, it is more efficient and reliable. The molecules can be cross-linked along the polarization direction. Then, when the molecules are cross-linked, the orientation state is stabilized in a three-dimensional structure, and the orientation state does not change even if the liquid is dried and dried again. First
The above-described manufacturing method in which the step and the second step are repeated uses such a property. That is, the cross-linked area irradiated with the polarized light is not preliminarily oriented again by the draining-drying process again, while the other thin-film regions are subjected to the first draining-drying process by the draining-drying process again. As a result, the temporary alignment is released, and the liquid crystal layer can be temporarily aligned in the direction of liquid drainage and drying performed again. By repeating the temporary alignment and the alignment fixing operation by polarized light irradiation, a liquid crystal alignment film having excellent multi-domain characteristics is formed. More specifically, an object is to obtain a liquid crystal alignment film having excellent multi-domain characteristics capable of giving different pretilt angles and / or pretilt orientations for each divided pixel.

There is no particular limitation on the size of N in the above-described manufacturing method.
Is set to 2-4. To give a different pretilt angle and / or pretilt azimuth for each divided pixel means, for example, that one pixel is divided into two parts.
This means that the pretilt angle at the other divided pixel is set to, for example, 4 °, or the pretilt azimuth of each divided pixel is opposite to the boundary surface between both divided pixels.

Here, as the two or more silane compounds, two or more silane compounds having different molecular long axes can be used in combination. Further, by changing the mixing ratio of the two or more silane-based compounds as the silane-based chemisorbent, the inclination of the longest molecule with respect to the substrate is controlled, and the desired pretilt angle and / or pretilt in the liquid crystal alignment film is obtained. Orientation can be given.
In addition, by changing the length of the short molecule in the mutual comparison without changing the mixing ratio of the two or more silane-based compounds, the inclination of the longest molecule with respect to the substrate is controlled, and the desired orientation of the liquid crystal alignment film is obtained. A desired pretilt angle and / or pretilt azimuth can be provided. Further, as the silane-based chemisorbing substance, the length of one or more molecular chains selected from the group consisting of a linear carbon chain and a linear siloxane bond chain was changed to change the molecular length. More than one kind of the compounds can be used as a mixture. Furthermore, the mixing ratio of the two or more compounds is changed, and / or
Alternatively, by controlling the molecular length of each compound and controlling the inclination of the longest molecule with respect to the substrate, desired liquid crystal alignment characteristics can be imparted to the liquid crystal alignment film.

The short molecule and the long molecule in the above-mentioned mutual comparison are concepts defined by a relative relationship, and therefore, there is no particular restriction on the length. Generally, a molecule having a length of 1 to 18 carbon atoms is used as a short molecule, and a molecule having 14 to 18 carbon atoms is used as a long molecule. Also, the preferred mixing ratio of long molecules and short molecules is
It should be determined based on the mutual relationship, and no limitation can be set in advance. However, in general, the mixing ratio of the two is as follows: the number of long molecules / the number of short molecules = 10/1.
It is appropriate to change in the range of 〜1 / 10. This is because within this range, a sufficient mixing effect can be obtained.

It is preferable to use a water-free non-aqueous organic solvent as the cleaning liquid. If the solvent contains water, the water contained in the solvent reacts with the chemically adsorbed substance, the adsorption ability of the chemically adsorbed substance to the substrate is reduced, and spots are generated on the alignment film due to the reaction product. is there. As a preferable non-aqueous organic solvent, at least one organic group selected from the group consisting of an alkyl group, a carbon fluoride group, a carbon chloride group and a siloxane group is preferred because of its excellent solubility in a chemically adsorbed substance. Examples of the solvent include.

The silane-based chemisorbing substance includes a photosensitive group, at least one molecular chain selected from the group consisting of a linear carbon chain and a linear siloxane bonding chain, a chlorosilyl group, an alkoxysilyl group and the like. It is preferable to use a compound containing at least one organic group selected from the group consisting of a group and an isocyanatesilyl group. Since this compound has excellent reactivity with the substrate and can cross-link molecules by irradiation with polarized light, it is convenient as a chemisorbate constituting a thin film. Examples of the photosensitive group in this compound include a cinnamoyl group, a chalcone group, and a methacryl group.

The compound may include a carbon trifluoride group (-CF3) and a methyl group (-CH3) at the terminal or a part of the linear carbon chain or the linear siloxane bond chain.
), Vinyl group (-CH = CH2), allyl group (-CH
= CH-), an acetylene group (carbon-carbon triple bond),
Phenyl group (-C6 H5), aryl group (-C6 H4)
-), A halogen atom, an alkoxy group (-OR; R represents an alkyl group), a cyano group (-CN), an amino group (-N
H2), a hydroxyl group (-OH), a carbonyl group (= CO),
Ester group (-COO-) and carboxyl group (-CO
Those having at least one organic group selected from the group consisting of OH) are preferred. With these compounds,
This is because a desired pretilt angle is easily obtained.

In the above manufacturing method, a step of forming a base layer having a SiO group on the substrate surface can be added before the thin film forming step. The substrate on which the underlayer having the SiO group is formed is excellent in that the SiO group acts as a hydrophilic group, so that a chemically adsorbed substance can be chemically adsorbed at a high density.

(3) The liquid crystal display device using the liquid crystal alignment film described above can be configured as follows.

At least a pair of opposing substrates, a liquid crystal alignment film formed on a surface of at least a substrate having a display electrode out of the pair of substrates, and a liquid crystal alignment film accommodated in a cell gap provided between the pair of opposing substrates. A liquid crystal display device comprising a liquid crystal, wherein the liquid crystal alignment film is a monomolecular layer-like thin film in which the chemisorbate molecules are bonded to the substrate surface, and the chemisorbate molecules are cross-linked. In addition, the tilt and / or orientation of the long axis of the adsorbate molecule with respect to the substrate surface is different for each divided pixel in which one pixel is divided in a pattern, and the pretilt angle and / or the liquid crystal molecule accommodated in the cell gap are different. Alternatively, the pretilt direction is controlled by the inclination and / or the orientation direction of the major axis of the adsorbate molecule with respect to the substrate surface.

In the liquid crystal display device having the above structure, the liquid crystal accommodated in the gap between the pair of opposed substrates is a nematic liquid crystal, and the cell gap is twisted at 90 ° or 180 ° to 270 °. Can be set to

Further, the liquid crystal display device may be an in-plane switching type liquid crystal display device having a pair of display electrodes formed on one substrate surface.

(4) The liquid crystal display device described in (3) above comprises a silane-based chemisorbent containing a photosensitive group and a linear carbon chain or a linear siloxane bond chain, and a non-aqueous organic solvent. A thin film for forming a monomolecular layer-like thin film by contacting the contained chemisorption liquid with the substrate surface having the display electrode, and causing the chemisorption substance molecules in the chemisorption liquid to chemically adsorb to the substrate surface at one end in the molecular long axis direction. Forming step, after washing the monomolecular layer-like thin film with a washing liquid composed of a non-aqueous organic solvent, and erecting the substrate in a certain direction, draining the washing liquid, and drying, so that the orientation direction of the thin film constituent molecules is in a certain direction. A temporary alignment step of temporarily aligning the substrate, and irradiating the temporarily aligned thin film surface with patterned polarized light having a different polarization direction to cross-link the molecules of the chemisorbed substance, thereby forming a long-axis substrate surface of the thin film constituent molecules. Tilt with respect to Or, an orientation imparting step of forming a substrate with a liquid crystal alignment film having a different alignment orientation, and a step of forming the substrate with the liquid crystal alignment film and a counter substrate having at least a counter electrode, with a surface on which a display electrode is formed, facing a predetermined cell. After the gaps are formed and overlapped, the liquid crystal display device can be manufactured by a manufacturing method of a liquid crystal display device including at least a liquid crystal cell forming step of arranging a liquid crystal between both substrates.

In this manufacturing method, a nematic liquid crystal is used as the liquid crystal disposed between the two substrates, and the inclination and / or orientation of the major axis of the thin film constituent molecules with respect to the substrate surface and the cell gap are determined by the liquid crystal molecules. Can be configured to be twisted at 90 ° or 180 ° to 270 °. According to this manufacturing method, a multi-domain liquid crystal display device having a wide viewing angle can be manufactured with high productivity.
In addition, since the alignment characteristics of the liquid crystal alignment film are hardly deteriorated, a liquid crystal display device that exhibits excellent display performance over a long period of time can be manufactured.

[0046]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to an example of a method for manufacturing a multi-domain liquid crystal display device according to the present invention.

A photosensitive group and a linear carbon chain or a straight-chained carbon chain are formed directly on the first substrate on which the first electrode group and the TFT formed in a matrix are formed, or after forming an SiO2 layer as an underlayer. A chemisorption solution obtained by dissolving a silane-based chemisorbent having a chain-like siloxane bond chain in a non-aqueous organic solvent is brought into contact, and the chemisorbent molecules in the adsorbate are chemisorbed to the substrate surface. This makes it possible to form a monomolecular layer-like thin film in which one end of the chemisorbed substance molecule is bonded to the substrate surface. Here, the contact of the chemical adsorption liquid is preferably performed in a low humidity atmosphere (for example, a relative humidity of 35% or less).

Subsequently, the substrate with a thin film is immersed in a solvent bath filled with a non-aqueous organic solvent to wash away unreacted molecules,
Thereafter, the substrate is pulled out of the solvent bath and drained and dried while standing in a certain direction. Thereby, the adsorbed molecules constituting the thin film can be temporarily oriented in the draining and drying direction.

Next, the first patterned mask is superimposed on the polarizing plate and the adjusted patterned polarized light whose polarization direction is parallel to the temporary alignment direction is irradiated onto the temporarily oriented thin film surface. As a result, the photosensitive groups of the thin-film constituent molecules (adsorbed molecules) can be selectively photopolymerized, and a pattern-like region in which the thin-film constituent molecules (adsorbed molecules) are cross-linked in a specific direction on the substrate surface can be formed. When irradiating the pattern-shaped polarized light, irradiation is performed so that each pixel constituting the pattern is irradiated to different pixels.

Thereafter, the substrate with the thin film cross-linked as described above is immersed in the solvent tank once again, and this time, the substrate is pulled up by changing the pulling direction from the first time, and the substrate is set up in this direction for the second time.
The second liquid drainage and drying is performed to reorient the thin film constituent molecules in this direction. It should be noted that the molecules constituting the thin film in the pattern region cross-linked for the first time are no longer re-oriented because the alignment state is fixed by the cross-linking.

Subsequently, a second pattern-like mask different from the above pattern is superimposed on the unirradiated portion in the first time,
A pattern of polarized light in a direction parallel to the reorientation direction is irradiated, and selective photopolymerization is performed to crosslink the thin film constituent molecules in the same manner as in the first time. Hereinafter, the same operation is repeated as necessary to form a plurality of regions having different orientations (inclination and / or orientation of constituent molecules with respect to the substrate) in a pattern on the thin film surface. Thereby, the first substrate with a liquid crystal alignment film according to the present invention is completed.

Next, a first substrate having the first electrode group and a second substrate having a second electrode group separately prepared (with or without an alignment film) are prepared. Then, positioning is performed while maintaining a predetermined gap with the electrode surface inside, and the periphery of the substrate is bonded and fixed. Thereafter, for example, a nematic liquid crystal is injected between the first and second substrates to form a liquid crystal cell. A polarizing plate and a backlight are arranged in the liquid crystal cell according to a conventional method to produce a multi-domain liquid crystal display device according to the present invention.

The liquid crystal display device manufactured according to the above-described manufacturing method has a different pretilt angle and / or pretilt direction for each divided pixel. This is realized by means for making the tilt and / or orientation of the molecule () relative to the substrate different for each region. The means and modes for making the inclination and / or the orientation of the thin film constituent molecules with respect to the substrate different for each region have been described in detail in the above [Means for Solving the Problems]. Therefore, although the description is omitted here, the orientation of the thin film constituent molecules can be controlled by the direction of drying and drying and the polarization direction, and the inclination of the thin film constituent molecules with respect to the substrate is a mixture of a plurality of types of adsorbate molecules having different molecular lengths. Can be controlled by the method used. Also, the inclination of the thin film constituent molecules with respect to the substrate can be controlled to some extent by changing the leaning angle in the drainage drying.

Hereinafter, embodiments of the present invention will be specifically described based on examples.

[0055]

[Example 1] [Example 1] ITO (indium tin oxi
A glass substrate (containing a large number of hydroxyl groups) on which a transparent electrode composed of de) is formed is prepared, and the substrate surface is thoroughly cleaned and degreased.
Two films were formed by a sputtering method.

On the other hand, as a silane-based chemisorbing substance (also referred to as a surfactant) containing a photosensitive group, a linear carbon chain (which may be a hydrocarbon group or the like) and silicon, C6 H5 CH = CHC
A compound represented by OC6H4O (CH2) 6OSiCl3 was prepared, and this compound was dissolved in dehydrated hexadecane (a non-aqueous organic solvent) at a concentration of about 1% by weight to form a chemical adsorption solution.

Next, as shown in FIG. 1, the chemical adsorption solution 2 was filled in a solvent tank, and the glass substrate 1 was immersed in the solvent tank in a dry atmosphere (at a relative humidity of 30% or less) for about 1 hour. It should be noted that a coating method can be used instead of immersion. Thereafter, the substrate 1 is taken out of the solvent bath, and immersion cleaning is repeated three times for about 10 minutes using dehydrated n-hexane 3 (a non-aqueous organic solvent). The substrate was pulled up in the direction (direction of 5), drained and dried (FIG. 2), and further kept in a state in which the substrate surface was parallel to the gravity, and allowed to stand still in air containing water for a while. By this standing, Cl groups of unreacted adsorbed molecules are replaced with OH groups, and the chemisorbability of the adsorbate molecules is deactivated. In this way,
A monomolecular layer-like thin film (thickness: about 1.8 nm) composed of chemisorbed molecules temporarily oriented in the draining and drying direction was formed (FIG. 3). In FIG. 3, 4a represents a photosensitive base.

The above-prepared monomolecular thin film (chemisorption monomolecular film 4) was subjected to FTIR (Fourier transfor
Inspection by the liquid crystal test cell alignment method and m infrared spectroscopy) method confirmed that the adsorbate molecules constituting the thin film were oriented in the direction of drainage and drying.

Further, the above-prepared monomolecular thin film (chemically adsorbed monomolecular film 4) is applied to an FTIR (Fourier transfor
m Infrared spectroscopy), the SiCl group of the chlorosilane-based chemisorbed substance and the hydroxyl group on the substrate surface undergo a dehydrochlorination reaction, and the bond of the following formula (Formula 1) is formed. Thus, it was confirmed that a bond represented by the following formula (Formula 2) was generated.

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Next, using a photomask 7 in which a partially shielded mask 7a and a polarizing plate (HNP'B manufactured by Polaroid) are superimposed, the polarization direction 6 is almost parallel to the pulling direction 5 (for example, 3 , But may be perfectly parallel)) and use a super-high pressure mercury lamp to apply ultraviolet light (UV light) 8
Irradiation was performed so as to be 00 mJ / cm 2 (FIG. 4). In the figure,
Reference numeral 10 denotes a transparent electrode.

When the thin film after the UV light irradiation was analyzed by FTIR, the chemisorbed molecules were oriented in the polarization direction in the portion irradiated with the polarized UV light, and the carbon in the vinyl group portion of the chemisorbed substance molecule was changed. It was confirmed that the adsorbed molecules were cross-linked 4 ′ via a bond (see Chemical Formula 3) (see FIG. 5).

Embedded image

Thereafter, the substrate is immersed again in the solvent bath (for about 5 minutes), and the direction 5 ′ is completely opposite to the pulling direction 5.
The substrate was pulled up, drained and dried. The thin film on the substrate surface was subjected to FTIR analysis. As a result, there was no change in the cross-linked portion 4 ′ already irradiated with UV, but the chemisorbed molecule 4 ″ in the unirradiated portion was pulled up from the second cleaning liquid. It was confirmed that the adsorbed molecules were reoriented in the direction opposite to the direction 5 ′, that is, in the direction of drainage and drying (FIG. 6).

Next, a mask 7'a for partially shielding the already irradiated portion and a polarizing plate (HNP'B manufactured by Polaroid)
Are superimposed so that the polarization direction is substantially parallel to the pull-up direction 5 ′ (for example, shifted by 3 ° with respect to the pull-up direction 5 ′). Ultraviolet light (UV light) 8
Irradiation was performed so as to be 00 mJ / cm 2 (FIG. 7).

After that, when analyzed using FTIR, in the chemisorption film 4 ″ at the portion irradiated with the polarized UV light, the chemisorbed molecules are in the second polarization direction 9 ′.
It was confirmed that photopolymerization progressed and the adsorbed molecules were cross-linked 4 ′ ″ via the carbon bond (Chemical Formula 3) of the vinyl group of the chemisorbed substance molecule (see FIG. (FIG. 8).

Next, using the two substrates with the chemical adsorption film (liquid crystal alignment film) prepared above, the chemical adsorption films are opposed to each other, and the exposed portions are anti-parallel aligned. A micron liquid crystal cell was assembled, a nematic liquid crystal (ZLI4792, manufactured by Merck) was injected, and the alignment state of the liquid crystal was examined. As a result, the injected liquid crystal molecules have a pretilt angle of about 1 ° with respect to the substrate along the chemisorbed molecules, respectively, and the pretilt direction is opposite to the directions 5, 5 ′ pulled up from the cleaning liquid and the direction 9,
It was confirmed that the film was oriented in the direction parallel to the polarization direction 6 at 9 ′. This result was consistent with the analysis result by FTIR. From the above, it was proved that the orientation regulating direction for the liquid crystal molecules can be changed by changing the direction of draining and drying the cleaning liquid and the direction of polarization of polarized light irradiation without changing the composition of the substance constituting the chemical adsorption film.

At this time, if silicon is contained at the terminal of the molecule constituting the film, it is convenient for producing a liquid crystal alignment film having high peeling resistance.

A similar alignment film could be produced by using a substance containing at least one organic group selected from an alkoxysilyl group and an isocyanatesilyl group instead of the chlorosilyl group.

Further, as a silane-based chemisorbing substance, a carbon trifluoride group is added to the terminal or a part of a linear carbon chain (a linear siloxane bonding chain (—SiO—) can be treated similarly). (-CF3), methyl group (-CH3), vinyl group (-CH = CH2), allyl group (-CH = CH-), acetylene group (carbon-carbon triple bond), phenyl group (-
C6H5), an aryl group (-C6H4-), a halogen atom, an alkoxy group (-OR; R represents an alkyl group),
Cyano group (-CN), amino group (-NH2), hydroxyl group (-OH), carbonyl group (= CO), ester group (-
When a compound containing at least one organic group selected from COO-) and a carboxyl group (-COOH) is used, the pretilt angle changes according to the type of the introduced organic group, and it is confirmed that the pretilt angle can be controlled in a wide range. Was.

When a solvent containing at least one organic group selected from an alkyl group, a carbon fluoride group, a carbon chloride group and a siloxane group is used as the non-aqueous organic solvent,
A liquid crystal alignment film having excellent alignment controllability was manufactured.

(Example 2) C6H5 as a chemisorbed substance
CH = CHCOC6 H4 O (CH2) 6 OSiCl3 and CH3 (CH2) 18 SiCl3 each in a ratio of 1: 0.1
And a liquid crystal alignment film was prepared in the same manner as in Example 1 except that they were mixed and used at a ratio of 1: 0.2 (weight ratio), and the same analysis as in Example 1 was performed.

As a result, in the case of the weight mixing ratio of 1: 0.1, the orientation direction (pretilt azimuth) was reversed in each part as in Example 1, and the pretilt angles in each case were 1.5 ° and 1. 4 °. In the case of a weight mixing ratio of 1: 0.2, the orientation direction was reversed in each part, and the pretilt angles were 2.1 ° and 2.3 °, respectively.
Met.

As described above, when a chemisorbed substance obtained by mixing two kinds of chemisorbed molecules having different lengths is used, if at least one of the chemisorbed molecules has a photosensitive group, it can be irradiated with polarized light. It was confirmed that the adsorbed molecules could be polymerized in a desired direction via the photosensitive group, and thereby the liquid crystal orientation could be imparted to the chemically adsorbed film. Also, it was confirmed that the pretilt angle of the liquid crystal could be changed by changing the weight mixing ratio.

When a chemical adsorbent incorporating a linear siloxane bonding chain instead of a linear carbon chain is used as the chemical adsorption substance, the pretilt angle is different from that of the linear carbon chain. The pretilt angle of the liquid crystal could be changed by changing the weight mixing ratio.

Further, substantially the same alignment film was obtained by using a substance containing at least one organic group selected from an alkoxysilyl group and an isocyanatesilyl group instead of the chlorosilyl group of the chlorosilane-based chemisorbed substance.

Example 3 C6 H5 as a chemisorbed substance
CH = CHCOC6 H4 O (CH2) 6 OSiCl3 combined with CH3 (CH2) 22 SiCl3;
6 H5 CH = CHCOC6 H4 O (CH2) 6 OSiC
A liquid crystal alignment film was prepared in the same manner as in Example 2 except that l3 and CH3 (CH2) 14 SiCl3 were combined and used in a ratio of 1: 0.1 (weight ratio). Was analyzed.

As a result, C6 H5 CH = CHCOC6 H
4 O (CH2) 6 OSiCl3 and CH3 (CH2) 22S
In the case of the combination of iCl3, the orientation directions were reversed at the respective portions, as in Example 2, and the pretilt angles were 1.1 °, respectively. Also, C6 H5 CH = CHCO
C6 H4 O (CH2) 6 OSiCl3 and CH3 (CH2
) In the combination of 14SiCl3, the orientation direction was reversed in each part and the pretilt angle was 0.8 °.

As described above, the pretilt angle of the liquid crystal can be changed by changing the length of the constituent molecules of the thin film without changing the mixing ratio.

Example 4 C6 H5 as a chemisorbed substance
CH = CHCOC6 H4 O (CH2) 6 OSiCl3 and CF3 (CF2) 7 (CH2) 2 SiCl3 were combined and used in a mixing ratio of 1: 0.1 (weight ratio). went.

As a result, as in the case of the second embodiment, the orientation directions are reversed at the respective portions, and the pretilt angles are 8
9 °. From this, it was confirmed that a liquid crystal alignment film having vertical (homeotropic) alignment characteristics can be formed by using a compound incorporating a fluorine atom in a mixture with another chemical adsorption substance.

(Embodiment 5) In Embodiment 1, adsorbates are adsorbed on a substrate having a SiO2 film formed on the surface of the substrate in advance as an underlayer. In Embodiment 5, instead of the SiO2 film, an adsorbate is used.
A substrate subjected to a treatment of bringing an inorganic silane-based chemical adsorbent containing an iCl group into contact with the substrate surface was used.

Specifically, SiCl 4 is used as an inorganic silane-based chemical adsorbent containing a SiCl group, and this compound is dissolved in dehydrated hexadecane at a concentration of about 3% by weight in a dry atmosphere (5% humidity). The substrate 1 having the electrodes described in Example 1 was immersed therein for 10 minutes. As a result, FIG.
A monolayer coating 11 made of> SiCl2 or -SiCl3 as shown in FIG. Then, after washing with well-dehydrated cyclohexane to remove excess SiCl4, it was reacted with water to form a siloxane monomolecular film 12 containing a large number of hydroxyl groups on both the glass surface and the ITO electrode surface, as shown in FIG. ) Formed.

Thereafter, using the substrate on which the underlayer was formed by the above method, the same steps as in Example 1 were carried out to produce a substrate with a liquid crystal alignment film. Then, FTIR analysis was performed on the liquid crystal alignment film. As a result, as in Example 1, it was confirmed that the alignment film was uniformly formed on the entire substrate surface.

The film 11 can be formed on the substrate by the method described above because the glass surface or the ITO electrode surface is
This is because some hydroxyl groups (-OH) are present.

A substrate with an alignment film was prepared in the same manner as in Example 1 except that a substrate having no underlayer was used, and the alignment was examined using liquid crystal. As a result, the liquid crystal molecules were well aligned on the glass substrate, but the alignment was disordered on the ITO electrode, and the disorder was not practical. The reason for this is that although a relatively large number of OH groups exist on the glass surface, the O
This is probably because the H group density is low and the adsorbed molecules cannot be sufficiently adsorbed.

Incidentally, according to an experiment conducted separately, SiCl
It was confirmed that when a substance represented by Cl (SiCl2 O) n SiCl3 (n is an integer of 1 to 3) was used instead of 4, the effect of increasing hydroxyl groups on the ITO surface was greater. These substances have an advantage that they are easy to handle because they have a higher boiling point than SiCl4.

(Embodiment 6) Next, a manufacturing process for actually manufacturing a liquid crystal display device using the liquid crystal alignment film will be described with reference to FIG.

First, as shown in FIG. 11, a Si substrate is provided on a first substrate 23 having a first electrode group 21 arranged in a matrix and a transistor group 22 for driving the electrodes.
After forming the O2 film, a chemical adsorption solution was applied according to the same procedure as in Example 1 to form a thin film (chemical adsorption monomolecular film) on the substrate surface.

Next, the thin film is washed with chloroform which is a non-aqueous organic solvent, the substrate is set up in the direction of the gate baseline, pulled up from the washing solution, drained and dried, and the thin film forming molecules are oriented in the first draining direction. I let it. Thereafter, a mask having a light-shielding pattern capable of exposing only a specific one of the divided pixels (first divided pixel group) obtained by dividing the individual electrodes of the electrode group into four in a checkered pattern, and a polarizing plate HNP'B
(Polaroid), an exposure mask is positioned on the first divided pixel group, and the drying direction and the polarization direction are parallel to each other. Irradiation was performed for 45 seconds with light having a wavelength of 365 nm (i-line) (3.6 mJ / cm 2 after passing through the polarizing plate) (first time).

The divided pixel means a section obtained by dividing one electrode into four, and the divided pixel group is a concept corresponding to an “electrode group” composed of a large number of electrodes arranged in a matrix. It is used to include a specific divided pixel of each electrode of the electrode group. In order to increase the productivity, the divided pixel groups are simultaneously irradiated with light.

Following the first treatment, the first treated substrate is immersed again in the same cleaning solution for 5 minutes, and then the substrate is pulled up in the opposite direction to the first treatment to perform a second drying and drying. The unexposed portions of the thin-film constituent molecules were oriented in the direction of the second drying and drying. Next, in the same manner as in the first time, the exposure mask was aligned with the second divided pixel group, and polarized light was irradiated so that the direction of drying and drying in the second time was parallel to the direction of polarization (second time). ).

Further, the substrate was immersed again in the same cleaning solution for 5 minutes, the substrate was pulled up in a direction orthogonal to the first and second times, and the liquid was dried and dried for the third time. The constituent molecules were oriented in the third drainage drying direction. Next, in the same manner as in the first time, the exposure mask is aligned with the third divided pixel group, and the polarized light is irradiated so that the third drying and drying direction is parallel to the polarized direction (third time). ).

Finally, the substrate was immersed again in the same cleaning solution for 5 minutes, the substrate was pulled up in the direction opposite to the third time, and the liquid was dried and dried for the fourth time. Orientation was performed in the drying direction. And
In the same manner as in the first time, the exposure mask was aligned with the fourth divided pixel group, and the polarized light was irradiated so that the liquid drainage drying direction and the polarization direction became parallel in the fourth time (fourth time).

By the above processing, the molecules constituting the thin film are changed to those shown in FIG.
The liquid crystal alignment films 27 each having the alignment in the directions shown in FIG. In the figure, 40 indicates the direction of the gate baseline, 41 indicates the alignment direction of the liquid crystal, and 42 indicates one pixel.

On the other hand, the color filter group 24 and the second
A liquid crystal alignment film 27 ′ is formed on the surface of the second substrate 26 having the electrode 25 by the same method as described above so that the alignment direction of the pixels corresponding to each pixel of the liquid crystal alignment film 27 is anti-parallel. did.

Next, the first substrate 23 and the second substrate 2
6 were overlapped with the electrode surface facing each other with a spacer 28 interposed therebetween, and the periphery thereof was hermetically sealed with an adhesive 29 to produce an empty cell having a cell gap of 5 μm. Thereafter, a nematic liquid crystal 30 was injected into the cell to form a liquid crystal cell, and further, polarizing plates 31 and 32 were disposed to complete a multi-domain liquid crystal display device (FIG. 11).

The pretilt angle of the liquid crystal injected into the liquid crystal cell was substantially 1 °, and was substantially uniform in all regions. In addition, the orientation direction (pretilt direction) differs for each divided pixel as shown in FIG. 12, and the orientation is shifted by 90 ° between the divided pixels.

In the above liquid crystal display device, while irradiating the backlight 33, each transistor was driven using a video signal to display an image in the direction of arrow A, and the viewing angle was examined. A sufficient viewing angle could be secured.

[Other Matters] The orientation and cell gap of the liquid crystal alignment films of the first substrate and the second substrate are determined by the same method as that described in the fifth embodiment. When the liquid crystal molecules were set to be twisted at 90 ° in relation to the molecules, a TN-type multi-domain liquid crystal display device having a wide viewing angle could be manufactured.

Further, an IPS (inplane switching) type TFT array in which a pair of electrodes are formed on one substrate surface is used as a first substrate to form a substrate with a two-pixel multi-domain alignment film. Was used to produce a liquid crystal display device, and the display characteristics were examined. As a result, it was confirmed that an IPS multi-domain liquid crystal display device having excellent viewing angle characteristics could be realized.

In the above embodiment, light of 365 nm, which is i-line of an ultra-high pressure mercury lamp, is used as light for exposure.
m, 405 nm, 254 nm light, or 248 nm light obtained with a KrF excimer laser can also be used. Among them, the light of 248 nm or 254 nm is absorbed by most of the substances, so that the orientation giving efficiency is high.

In addition to a photosensitive group, a linear carbon chain or a linear siloxane bonding chain, silicon, etc., a nematic liquid crystal having a more specific surface energy may be incorporated into the chemical structure of the chemisorbed substance molecule. It is also possible to incorporate a structure or a ferroelectric liquid crystal structure, whereby it is possible to further increase the alignment regulating force.

[0102]

As described above, according to the present invention, it is possible to provide an extremely thin alignment film which is excellent in alignment regulation characteristics and durability for liquid crystal molecules and which does not hinder light transmission and electric field. Further, according to the present invention, since a rubbing operation is not required for imparting the orientation, various problems associated with rubbing such as alignment defects caused by unevenness on the substrate surface and display defects caused by dust during rubbing can be eliminated at once.

Further, according to the manufacturing method of the present invention, a liquid crystal alignment film having excellent alignment regulating force and capable of controlling the pretilt angle and the pretilt direction for each region of the alignment film can be manufactured with a high yield. By using such a liquid crystal alignment film, a multi-domain liquid crystal display device having excellent viewing angle characteristics can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a chemical adsorption step for producing a monolayer thin film in Example 1 of the present invention.

FIG. 2 is a view for explaining a thin film cleaning step in Embodiment 1 of the present invention.

FIG. 3 is a conceptual diagram showing a temporary orientation state of a thin film constituent molecule in Example 1 of the present invention (after the first liquid removal and drying).

FIG. 4 is a view for explaining a polarized light irradiation step in Embodiment 1 of the present invention.

FIG. 5 is an enlarged conceptual diagram for explaining the first polarized light irradiation in the first embodiment of the present invention at a molecular level.

FIG. 6 is a conceptual diagram for explaining, at a molecular level, a state of a thin film after a second drainage and drying in Example 1 of the present invention.

FIG. 7 is a conceptual diagram for explaining, at a molecular level, an orientation state of a thin film after a second irradiation of polarized light in Example 1 of the present invention.

FIG. 8 is a diagram for explaining an orientation direction of molecules constituting a thin film after a second irradiation of polarized light in Example 1 of the present invention.

FIG. 9 is a diagram showing a state in which an inorganic silane-based chemisorbed molecule is chemically adsorbed on a substrate surface (before a reaction with moisture in the air).

10 is a diagram showing that the inorganic silane-based chemisorbed molecule shown in FIG. 9 reacts with moisture to change to an OH-rich compound.

FIG. 11 is a schematic cross-sectional view for explaining the production of a liquid crystal display device according to the present invention.

FIG. 12 is a diagram illustrating a liquid crystal alignment direction of a four-divided multi-domain pixel in Embodiment 6 of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Substrate 2 Chemical adsorption liquid 3 Non-aqueous organic solvent for washing 4 Thin film which was provisionally oriented by the 1st liquid drainage and drying 4a Photosensitive base 4 'Thin film constituent molecule group after 1st light irradiation 4 "2nd time 4 ′ ′ Thin film constituent molecules after second light irradiation 5 ′ First pulling direction 5 ′ Second pulling direction 6 Polarization direction 7 Polarizing plate and light shielding part 1st exposure photomask 7a with light-shielding mask 7 'Second exposure photomask 7'a light-shielding mask with polarizing plate and light-shielding portion overlapped 8 UV irradiation light 9 first alignment direction 9' second alignment direction DESCRIPTION OF SYMBOLS 10 Transparent electrode 11 Adsorbed chlorosilane molecule 12 Underlayer made of siloxane 21 First electrode group 22 Transistor group 23 First substrate 24 Color filter group 25 Second electrode 26 Second substrate 27 Liquid crystal alignment film 27 '' Liquid crystal alignment film 28 Spacer 29 Adhesive 30 Liquid crystal 31, 32 Polarizer 33 Backlight 40 Gate baseline direction 41 Liquid crystal alignment direction

Claims (24)

(57) [Claims] 1. A thin film in the form of a monomolecular layer formed on the surface of a substrate having electrodes, and molecules constituting the thin film are chemically bonded to the substrate surface at one end, and a molecular long axis is defined for each region on the thin film surface. A liquid crystal alignment film formed by polymerizing thin film constituent molecules in a state where the orientation and / or the orientation are different from the substrate surface. 2. The liquid crystal alignment film according to claim 1, wherein each of the regions is obtained by dividing a plurality of sections corresponding to one pixel into a plurality of patterns. 3. The thin film according to claim 1, wherein a chemisorbing substance containing a photosensitive group, silicon, and a linear carbon chain or a linear siloxane bonding chain is chemisorbed on the substrate surface, and the chemisorbate molecules are combined with each other. The liquid crystal alignment film according to claim 1, wherein the liquid crystal alignment film is formed by crosslinking with a photosensitive base. 4. The liquid crystal alignment film according to claim 3, wherein the thin film constituent molecules have silicon at a terminal. 5. The thin film according to claim 1, wherein the thin film is composed of a plurality of types of molecules having different molecular long axes, and the plurality of types of molecules are bonded to the substrate surface in a mixed state. The liquid crystal alignment film as described in the above. 6. The liquid crystal alignment film according to claim 5, wherein the plurality of types of molecules have different lengths of a linear carbon chain or a linear siloxane bond chain included in a molecular structure. 7. A surface of a substrate having an electrode, wherein a chemisorption liquid containing a silane-based chemisorption substance containing a photosensitive group, a linear carbon chain or a linear siloxane bonding chain, and a non-aqueous organic solvent is applied. And forming a monolayer-like thin film by chemically adsorbing the chemisorbate molecules in the chemisorption solution to the substrate surface, and cleaning the monolayer-like thin film with a cleaning solution comprising a non-aqueous organic solvent. After that, the substrate is set up in a certain direction, and the cleaning liquid is drained and dried, thereby temporarily aligning the orientation direction of the molecules constituting the thin film in a certain direction. A method for producing a liquid crystal alignment film, comprising: a cross-linking step of irradiating a pattern-shaped polarized light having the following structure to cross-link constituent molecules in a specific direction. 8. The cross-linking step is performed two or more times on the thin film surface preliminarily oriented in the pre-alignment step by using polarized light having a different polarization direction for each irradiation and different irradiation regions for each irradiation. 8. The liquid crystal according to claim 7, wherein the step of irradiating polarized light is to change the inclination and / or the orientation of the thin-film constituent molecules with respect to the substrate surface for each of a plurality of divided regions corresponding to one pixel in a pattern. A method for manufacturing an alignment film. 9. The orientation-imparting step comprises, after cleaning the monomolecular thin film with a cleaning liquid comprising a non-aqueous organic solvent, setting up a substrate in a certain direction and draining and drying the cleaning liquid in a certain direction. Accordingly, a first alignment step of temporarily aligning the orientation direction of the constituent molecules of the thin film in a certain direction, and a second alignment step of irradiating polarized light having a polarization direction substantially parallel to the direction temporarily aligned in the first alignment step. A series of the following steps is repeated twice or more. The draining and drying direction at the Nth time (where N is an integer of 2 or more) is made different from the draining and drying direction up to the [N-1] th time, and the Nth time. By dividing the irradiation area on the substrate in the N-th polarized light irradiation following the liquid drainage drying from the irradiation area up to the [N-1] th irradiation, a plurality of sections corresponding to one pixel were divided into a plurality of patterns. Thin for each divided area A step of varying the inclination and / or alignment direction to the substrate surface of the long axis of the constituent molecules, a method of manufacturing a liquid crystal alignment film of claim 7. 10. The silane-based chemisorbed substance may be 2
8. A mixture of two or more silane compounds.
10. The method for producing a liquid crystal alignment film according to any one of items 9 to 9. 11. The method for producing a liquid crystal alignment film according to claim 10, wherein as the two or more silane compounds, two or more silane compounds having different molecular long axes are used in combination. 12. The tilt of the longest molecule with respect to the substrate is controlled by changing the mixing ratio of the two or more silane compounds as the silane-based chemisorbing substance, so that the liquid crystal alignment film has a desired pretilt angle and a desired tilt angle. The method for producing a liquid crystal alignment film according to claim 11, wherein a pretilt orientation is provided. 13. The liquid crystal alignment film by controlling the inclination of the longest molecule with respect to the substrate by changing the length of the short molecule in comparison with each other without changing the mixing ratio of the two or more silane-based compounds. Desired pretilt angle and / or
The method for producing a liquid crystal alignment film according to claim 11, wherein a pretilt orientation is provided. 14. The silane-based chemisorption material includes a photosensitive group, at least one molecular chain selected from the group consisting of a linear carbon chain and a linear siloxane bond chain, a chlorosilyl group and an alkoxysilyl group. The method for producing a liquid crystal alignment film according to any one of claims 7 to 13, wherein a compound containing at least one organic group selected from the group consisting of: and an isocyanate silyl group is used. 15. The compound further comprises a terminal or a part of the linear carbon chain or the linear siloxane bonding chain,
Fluorocarbon group (-CF3), methyl group (-CH3), vinyl group (-CH = CH2), allyl group (-CH = CH
-), Acetylene group (carbon-carbon triple bond), phenyl group (-C6 H5), aryl group (-C6 H4-), halogen atom, alkoxy group (-OR; R represents an alkyl group), cyano Group (-CN), amino group (-NH2),
15. The composition according to claim 14, which has at least one organic group selected from the group consisting of a hydroxyl group (-OH), a carbonyl group (= CO), an ester group (-COO-), and a carboxyl group (-COOH). A method for producing a liquid crystal alignment film. 16. When the length of one or more molecular chains selected from the group consisting of a linear carbon chain and a linear siloxane bond chain is changed as the silane-based chemisorbed substance, the molecular lengths are different. The method for producing a liquid crystal alignment film according to claim 14, wherein two or more of the compounds are mixed and used. 17. The tilt of the longest molecule with respect to the substrate is controlled by changing the mixing ratio of two or more kinds of the compounds and / or by regulating the molecular length of each compound, so that a desired liquid crystal alignment film can be formed. The method for producing a liquid crystal alignment film according to claim 14, wherein liquid crystal alignment characteristics are imparted. 18. The method according to claim 7, wherein the non-aqueous organic solvent is a solvent containing at least one organic group selected from the group consisting of an alkyl group, a carbon fluoride group, a carbon chloride group and a siloxane group. Method for producing liquid crystal alignment film. 19. Prior to the thin film forming step, S
19. The method for manufacturing a liquid crystal alignment film according to claim 7, further comprising a step of forming a base layer having an iO group. 20. At least a pair of substrates facing each other,
A liquid crystal display device comprising: a liquid crystal alignment film formed on a surface of at least a display electrode of the pair of substrates; and a liquid crystal accommodated in a cell gap provided between the pair of opposed substrates. The liquid crystal alignment film is a monomolecular layer-like thin film in which chemisorbate molecules are bonded to the substrate surface and the chemisorbate molecules are cross-linked, and one pixel is divided in a pattern. The tilt and / or orientation of the long axis of the adsorbate molecule with respect to the substrate surface is different for each, and the pretilt angle and / or the pretilt direction of the liquid crystal molecules accommodated in the cell gap is the length of the long axis of the adsorbate molecule. A liquid crystal display device, wherein the liquid crystal display device is controlled by a tilt and / or an orientation direction with respect to a substrate surface. 21. A liquid crystal accommodated in a gap between the pair of opposing substrates is a nematic liquid crystal, and the cell gap is such that liquid crystal molecules are 90 ° or 180 °.
The liquid crystal display device according to claim 20, wherein the liquid crystal display device is set to be twisted at an angle of ２270 °. 22. The liquid crystal display device according to claim 20, wherein the liquid crystal display device is an in-plane switching type liquid crystal display device having a pair of display electrodes formed on one substrate surface. 23. A chemically adsorbed liquid containing a silane-based chemisorbent containing a photosensitive group and a linear carbon chain or a linear siloxane bond, and a non-aqueous organic solvent are applied to the surface of a substrate having a display electrode. Contacting and chemically adsorbing the chemisorbed substance molecules in the chemisorption liquid to the substrate surface at one end in the molecular long axis direction to form a monomolecular thin film; and forming the monomolecular thin film into a non-aqueous system. After washing with a washing liquid composed of an organic solvent, the substrate is set up in a certain direction, and the washing liquid is drained and dried, thereby temporarily aligning the orientation direction of the thin film constituent molecules in a certain direction. By irradiating the patterned thin film with polarized light having different polarization directions and cross-linking the molecules of the chemisorbed substance, a liquid crystal alignment film with a different long axis of the thin film constituent molecules with respect to the tilt and / or alignment direction with respect to the substrate surface Base An orientation imparting step to be performed, and the substrate with a liquid crystal alignment film and at least a counter substrate having a counter electrode are overlapped with a predetermined cell gap provided with the surface on which the display electrode is formed on the inside, and A method for manufacturing a liquid crystal display device, comprising: a liquid crystal cell forming step of arranging a liquid crystal between substrates. 24. A nematic liquid crystal is used as the liquid crystal disposed between the two substrates, and the inclination and / or orientation direction of the major axis of the thin film constituent molecules with respect to the substrate surface and the cell gap are set to 90 °.
24. The method for manufacturing a liquid crystal display device according to claim 23, wherein the liquid crystal display device is formed so as to be twisted at 180 to 270 degrees.