JPH10325956A - Liquid crystal alignment layer and its production and liquid crystal display device formed by using this alignment layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal alignment layer which holds good orientability even with parts having differences in surface level and a large-area of about 14-inch display without the display defect and the degradiation of orientability accompanied by rubbing, a process for producing the same and a liquid crystal display device. SOLUTION: Surfactant molecules having straight chain carbon chains including diacetylene groups are fixed to the surface of a substrate 1 by effecting the chemical reaction of the chlorosilane groups of the molecular terminals thereof and the hydroxyl groups of the substrate surface. This surface is so washed that the liquid draining direction is made the same by the n-hexane. Further, the surface is exposed with a translucent substrate having irregular patterns of 0.01 to 0.5 μm on the surface in such a manner that the directions of the irregularities intersect nearly orthogonally with the direction of the liquid draining described above, by which the irregular patterns are transferred to the film. The liquid crystal display device is produced by forming this film as the liquid crystal alignment layer to a substrate form on which transparent electrodes, etc., are formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal alignment film, a method for manufacturing the same, and a liquid crystal display device using the alignment film. More specifically, 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 for manufacturing the same,
The present invention relates to a liquid crystal display device using the alignment film.

[0002]

2. Description of the Related Art Conventionally, a color liquid crystal display panel has a structure in which opposed electrodes arranged in a matrix are formed.
A device in which liquid crystal is sealed between two substrates via a liquid crystal alignment film formed by spin-coating a polyvinyl alcohol or polyimide solution with a spinner or the like is generally used.

For example, a first substrate in which a thin film transistor (TFT) array having pixel electrodes is formed on a glass substrate, and a plurality of red, blue, and green color filters are formed on a glass substrate, and a common transparent film is further formed thereon. A coating is formed by applying a polyvinyl alcohol or polyimide solution using a spinner or the like to each electrode surface of the second substrate on which the electrodes are formed, and rubbing the coating to form a liquid crystal alignment film. After arranging two substrates via a spacer so as to face each other, a liquid crystal (twisted nematic (TN) liquid crystal or the like) is injected between the substrates, and a polarizing plate is installed on both sides of the panel. A device that displays a color image by operating a TFT while irradiating a backlight is known.

[0004]

However, the conventional liquid crystal alignment film is formed by dissolving polyvinyl alcohol or polyimide in an organic solvent, applying the solution using a spin coating method or the like, and then performing rubbing using a felt cloth or the like. In a large-area panel such as a surface step portion or a 14-inch display, there is a problem that the uniformity of the alignment film cannot be sufficiently maintained. There is also a problem that rubbing causes a defect in the TFT, and dust generated by rubbing causes a display defect.

The present invention has been made in view of the above circumstances, and is directed to a liquid crystal alignment film suitably used for a liquid crystal display panel. The liquid crystal alignment film can maintain good alignment uniformity even on a surface step portion or a large area panel. It is an object of the present invention to provide a method for efficiently manufacturing the liquid crystal alignment film without rubbing and a liquid crystal display device using the liquid crystal alignment film.

[0006]

In order to achieve the above-mentioned object, the liquid crystal alignment film of the present invention is a film composed of a group of molecules whose one end is chemically adsorbed on the surface of a substrate, wherein the group of molecules is linear. It comprises a molecule having a carbon chain, wherein at least a part of the linear carbon chain is selectively polymerized with each other.

According to such a liquid crystal alignment film, it is possible to suppress the deterioration of the uniformity of the alignment even on a panel having a large area or a substrate having a stepped portion. Since this liquid crystal alignment film is provided with the alignment property to the liquid crystal without using physical contact means such as rubbing, the large area of the panel and the step on the substrate surface are fundamental to the uniformity of the liquid crystal alignment. Has no effect. In addition, since the liquid crystal alignment film is chemically adsorbed on the surface of the substrate, the liquid crystal alignment film also has excellent characteristics in film durability such as peel resistance.

[0008] In the liquid crystal alignment film, it is preferable that the inclination of the linear carbon chain with respect to the substrate is controlled at a constant angle by polymerization of the linear carbon chain.
This is because the alignment regulating force for the liquid crystal is improved.

In the liquid crystal alignment film, the molecule group includes a molecule shorter than a molecule having a linear carbon chain, and the presence of the molecule causes the inclination of the linear carbon chain with respect to the substrate to be a predetermined angle. Is controlled by selectively polymerizing at least a part of this linear carbon chain with each other,
It is preferable that the inclination with respect to the substrate increases or decreases from the angle, and the region where the linear carbon chain is polymerized forms a protrusion or a recess due to the increase or decrease. According to this preferred example, the projections or depressions controlled at the molecular level on the coating surface contribute to the improvement of the regularity of the liquid crystal alignment.

[0010] In the liquid crystal alignment film, a region where the linear carbon chain is polymerized is formed on the surface of the substrate by a plurality of lines substantially parallel to each other through a region where the linear carbon chain is not polymerized. It is preferable to form a strip. According to this preferred example, the alignment regulating force for the liquid crystal is further improved. The improvement of the alignment regulating force is achieved on the surface of the liquid crystal alignment film.
This is particularly noticeable when the above-mentioned convex portions or concave portions extend in the same direction.

In the liquid crystal alignment film, it is preferable that one end of a molecule having a linear carbon chain is fixed to the surface of the substrate via a siloxane bond. This is because the separation resistance and the like of the liquid crystal alignment film are further improved.

Further, in the liquid crystal alignment film, it is preferable that the molecules constituting the molecular group are bonded to each other via a siloxane bond. According to this preferred example, the peeling resistance and the like can be further improved, and the accuracy of alignment of the linear carbon chain with respect to the substrate can be further improved by bonding the molecules to each other.

In the method for producing a liquid crystal alignment film of the present invention, a surface of a substrate is brought into contact with a chemical adsorption solution, and a surfactant molecule having a linear carbon chain contained in the chemical adsorption solution and a hydrophilic group on the surface. And a chemical reaction between the step of fixing one end of the molecule to the surface, and selectively exposing a film made of a group of molecules containing the molecule, at least a portion of the linear carbon chain Imparting orientation to the substrate.

According to this method of manufacturing a liquid crystal alignment film, since rubbing is not involved, a liquid crystal alignment film having good uniformity even at a stepped portion on a large-sized panel or substrate surface can be efficiently and reasonably manufactured. Can be manufactured. In addition, since the application of the alignment regulating force to the liquid crystal is performed by utilizing the change in the alignment of the linear carbon chains due to the exposure, the production efficiency does not basically decrease even if the panel is enlarged.

In the method for producing a liquid crystal alignment film, the step of imparting orientation to at least a part of the linear carbon chains to the substrate is performed by polymerizing the linear carbon chains.
It is preferable that the step of controlling the inclination of the linear carbon chain with respect to the substrate to a constant angle. According to this preferred example, the inclination of the linear carbon chain with respect to the substrate is fixed,
A liquid crystal alignment film with improved liquid crystal alignment accuracy can be manufactured.

Further, in the above-mentioned method for producing a liquid crystal alignment film, one end of a molecule shorter than this molecule is fixed to the surface of a substrate together with a surfactant molecule having a linear carbon chain. By controlling the inclination of the carbon chain with respect to the substrate to a constant angle, and selectively polymerizing at least a part of the linear carbon chain with each other, the angle of the polymerized linear carbon chain with respect to the substrate is made smaller than the angle. It is also preferable to increase or decrease the concentration, and to increase or decrease the region where the linear carbon chain is polymerized to form a convex portion or a concave portion. According to this preferred example,
It is possible to manufacture a liquid crystal alignment film in which convex portions or concave portions controlled at the molecular level on the coating surface contribute to improvement of the alignment regulating force for the liquid crystal.

Further, in the method for producing a liquid crystal alignment film, after the step of fixing one end of a surfactant molecule having a linear carbon chain to the surface, a film comprising a molecule group containing this molecule is provided. It is preferable to include a step of cleaning the surface of the substrate with an organic solvent before the step of exposing the substrate. According to this preferred example, since the surplus surfactant molecules not fixed to the surface of the substrate are removed together with the organic solvent, the liquid crystal alignment film can be formed into a monomolecular film. By making the liquid crystal alignment film a monomolecular film, the alignment regulating force, the peeling resistance and the like can be further improved.

Further, in the method for producing a liquid crystal alignment film, in the step of washing with an organic solvent, drainage of the organic solvent from the surface of the substrate is performed in a predetermined direction, so that the linear carbon chains are reduced. It is preferable to orient in the predetermined direction. According to this preferred example, since the inclination of the linear carbon chain can be primarily oriented, the accuracy of the orientation of the liquid crystal can be further improved.

Further, in the method for producing a liquid crystal alignment film, the organic solvent is drained from the surface of the substrate in a predetermined direction so that the inclination of the linear carbon chain with respect to the substrate is fixed at a certain angle. And by selectively polymerizing at least a portion of the linear carbon chain with each other, the angle of the polymerized linear carbon chain with respect to the substrate is increased or decreased from the angle, and the increase or It is preferable that the region where the linear carbon chain polymerizes due to the reduction forms a convex portion or a concave portion. According to this preferred example, it is possible to manufacture a liquid crystal alignment film in which convex portions or concave portions controlled at the molecular level on the film surface contribute to the improvement of the alignment regulating force for the liquid crystal. As a method for imparting a primary orientation to the linear carbon chain, a method in which the direction of drainage of the organic solvent is set to a predetermined direction, and a method in which a surfactant having a linear carbon chain and a surfactant shorter than this molecule are used. When the method of fixing one end of the agent molecule to the surface of the substrate is used in combination, a liquid crystal alignment film that can further improve the alignment accuracy of the liquid crystal can be obtained.

In the method for producing a liquid crystal alignment film, a non-aqueous organic solvent containing at least one selected from an alkyl group, a fluorocarbon group, a carbon chloride group and a siloxane group is used as the organic solvent. preferable. According to this preferred example, in the cleaning step, it is possible to suppress the reaction between the surplus surfactant molecules not bonded to the substrate surface and the reactive molecules such as moisture in the air. Molecules can be reliably removed to form a good monomolecular film.

Further, in the method for producing a liquid crystal alignment film, the surface is exposed through a light-transmitting substrate having a plurality of irregularities extending in substantially the same direction.
It is preferable that a region where the linear carbon chain is polymerized forms a plurality of parallel lines through a region where the linear carbon chain is not polymerized. According to a preferable example of performing such selective exposure, it is possible to manufacture a liquid crystal alignment film in which the alignment control force for liquid crystal is further improved. The improvement in the alignment regulating force is particularly remarkable when the irregularities extend in the same direction on the surface of the liquid crystal alignment film.

Further, in the method for manufacturing a liquid crystal alignment film, the width and depth of the concave and convex portions on the surface are 0.01 to 0.1.
Exposure is preferably performed through a light-transmitting substrate having a thickness of 5 μm, and furthermore, light that reaches the coating via the light-transmitting substrate is preferably diffracted by unevenness of the light-transmitting substrate. This is because the alignment regulating force can be improved.

In the above method for producing a liquid crystal alignment film, the surfactant molecule having a linear carbon chain contains a silicon-containing group selected from a chlorosilane group, an alkoxysilane group and an isocyanate silane group at a molecular terminal. Is preferred. This is because a chemically adsorbed film having a high peeling resistance can be efficiently produced.

In the method for producing a liquid crystal alignment film, the surfactant molecule having a linear carbon chain preferably contains a photopolymerizable functional group in the linear carbon chain. Preferably, the polymerizable functional group is a diacetylene group. According to these preferred examples, the linear carbon chain is efficiently polymerized by exposure.

In the method of manufacturing a liquid crystal alignment film, when the coating is exposed through a light-transmitting substrate having a plurality of irregularities extending on the surface in substantially the same direction, the irregularities extend on the light-transmitting substrate. It is preferable that the direction is not orthogonal to the direction of draining the organic solvent. This is because the accuracy of liquid crystal alignment can be further improved. Here, the arrangement so as not to be orthogonal means that only the case where the arrangement is strictly orthogonal is excluded, and also includes the arrangement in a state close to orthogonal.

The liquid crystal display device of the present invention is arranged so as to keep a predetermined interval, has two substrates having a liquid crystal alignment film formed on at least one of the opposing surfaces, and is sandwiched between the two substrates. In a liquid crystal display device including a liquid crystal whose alignment is regulated by a liquid crystal alignment film, the liquid crystal alignment film is a film composed of a group of molecules whose one end is chemically adsorbed on the surface of the substrate, and the group of molecules is linear. It comprises a molecule having a carbon chain, wherein at least a part of the linear carbon chain is selectively polymerized with each other. In such a liquid crystal display device, a decrease in the uniformity of the liquid crystal alignment film is suppressed even in a panel having a large area or a step portion on the substrate surface, and the alignment of the liquid crystal is favorably maintained.

In the above-mentioned liquid crystal display device, it is preferable that the inclination of the linear carbon chain with respect to the substrate is controlled at a constant angle by polymerization of the linear carbon chain. This is because the alignment regulating force for the liquid crystal is improved.

In the liquid crystal display device, a step is formed on the surface by forming at least one thin film member selected from an electrode, a color filter and a thin film transistor on a part of the surface of the substrate. Even when a liquid crystal alignment film is formed in a region including the liquid crystal alignment film, deterioration in uniformity of liquid crystal alignment in a step portion as in the case where the liquid crystal alignment film is manufactured by rubbing is suppressed.

In the above liquid crystal display device, it is preferable that the liquid crystal alignment film includes regions having different alignment directions. This is because a display device having a wide viewing angle can be obtained.

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION The liquid crystal alignment film of the present invention contains a surfactant molecule having a linear carbon chain having one end fixed to the surface of a substrate. Such surfactant molecules include a carbon trifluoride group (—CF ₃ ), a methyl group (—CH ₃ ), and a vinyl group (—C
H = CH _2), allyl (-CH = CH-), an acetylene group (carbon - triple bond of carbon), a phenyl group (-C
₆ H ₆ ), an aryl group (—C ₆ H ₄ —), a halogen group, an alkoxy group (—OR; R represents an alkyl group, particularly preferably an alkyl group having 1 to 3 carbon atoms), and a cyano group (-CN), amino group (-NH _2), hydroxyl group (-O
H), a surfactant molecule containing at least one substituent selected from a carbonyl group (= CO), an oxycarbonyl group (-COO-), a carboxyl group (-COOH) and an isocyanate group (-NCO). Can be. As the surfactant molecule, a surfactant molecule having a substituent selected from a chlorosilane group, an alkoxysilane group and an isocyanatosilane group at a molecular terminal is preferable.

Further, as the surfactant molecule having a linear carbon chain, one having a photopolymerizable functional group such as a diacetylene group or an acetylene group in the linear carbon chain is preferable.
Specifically, surfactant molecules represented by the following formulas (1) to (6) are preferable.

[0032]

Embedded image

However, p and q are integers of 0 or more, preferably 0 to 10. R is an integer of 0 or more, and preferably an integer of 2 to 24.

The surfactant molecules which can be suitably used as shown in the above formulas (1) to (6) are preferably used by mixing with other types of surfactants. Examples of the surfactant molecule include surfactant molecules represented by the following formulas (7) to (20). (7) CH ₃ (CH ₂ ) _n SiCl ₃ (8) CH ₃ (CH ₂ ) _p Si (CH ₃ ) ₂ (CH ₂ ) _q SiCl ₃ (9) CH ₃ COO (CH ₂ ) _m SiCl ₃ (10 ) C ₆ H ₆ (CH ₂ ) _n SiCl ₃ (11) CN (CH ₂ ) _n SiCl ₃ (12) Cl ₃ Si (CH ₂ ) _s SiCl ₃ (13) Cl ₃ Si (CH ₂ ) ₂ (CF ₂ ) _t (CH ₂ ) ₂ SiCl ₃ (14) Ha (CH ₂ ) _u Si (OCH ₃ ) ₃ (15) CH ₃ (CH ₂ ) _n Si (NCO) ₃ (16) CH ₃ (CH ₂ ) _p Si (CH ₃ ) ₂ (CH ₂ ) _q Si (OCH ₃ ) ₃ (17) HOOC (CH ₂ ) _m Si (OCH ₃ ) ₃ (18) H ₂ N (CH ₂ ) _m Si (OCH ₃ ) ₃ (19 ) C ₆ H ₆ (CH ₂ ) _n Si (NCO) ₃ (20) CN (CH ₂ ) _n Si (OC ₂ H ₅ ) ₃ where Ha represents a halogen atom such as chlorine, bromine, iodine, fluorine, etc. m is an integer of 0 or more, preferably 7
N is an integer of 0 or more, preferably an integer of 0 to 24, s is an integer of 0 or more, preferably an integer of 3 to 24, and t is 0 or more. It is an integer, preferably an integer of 1 to 10. u is an integer of 0 or more, and preferably an integer of 1 to 24.

More specifically, there may be mentioned surfactant molecules represented by the following formulas (21) to (44). (21) Br (CH ₂ ) ₈ SiCl ₃ (22) CH ₂ = CH (CH ₂ ) ₁₇ SiCl ₃ (23) CH ₃ (CH ₂ ) ₈ -CO- (CH ₂ ) ₁₀ SiCl ₃ (24) CH ₃ (CH ₂ ) ₅ -COO- (CH ₂ ) ₁₀ SiCl ₃ (25) CH ₃ (CH ₂ ) ₈ -Si (CH ₃ ) _2- (CH ₂ ) ₁₀ SiCl ₃ (26) CH ₃ (CH ₂ ) ₁₇ SiCl ₃ (27) CH ₃ (CH ₂ ) ₅ Si (CH ₃ ) ₂ (CH ₂ ) ₈ SiCl ₃ (28) CH ₃ COO (CH ₂ ) ₁₄ SiCl ₃ (29) C ₆ H ₆ (CH ₂ ) ₈ SiCl ₃ (30) CN (CH ₂ ) ₁₄ SiCl ₃ (31) Cl ₃ Si (CH ₂ ) ₈ SiCl ₃ (32) Cl ₃ Si (CH ₂ ) ₂ (CF ₂ ) ₄ (CH ₂ ) ₂ SiCl ₃ ( 33) Cl ₃ Si (CH ₂ ) ₂ (CF ₂ ) ₆ (CH ₂ ) ₂ SiCl ₃ (34) CF ₃ CF ₂ (CF ₂ ) ₇ (CH ₂ ) ₂ SiCl ₃ (35) (CF ₃ ) ₂ CHO (CH ₂ ) ₁₅ Si (CH ₃ ) ₂ Cl (36) CF ₃ CF ₂ (CH ₂ ) ₂ Si (CH ₃ ) ₂ (CH ₂ ) ₁₅ SiCl ₃ (37) CF ₃ (CF ₂ ) ₄ (CH ₂ ) ₂ Si (CH ₃ ) ₂ (CH ₂ ) ₉ SiCl ₃ (38) CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ Si (CH ₃ ) ₂ (CH ₂ ) ₉ SiCl ₃ (39) CF ₃ COO ( (CH ₂ ) ₁₅ SiCH ₃ Cl ₂ (40) CF ₃ (CF ₂ ) ₅ (CH ₂ ) ₂ SiCl ₃ (41) CH ₃ CH ₂ CHC ^* H ₃ CH ₂ OCO (CH ₂ ) ₁₀ SiCl ₃ ) (42) CH ₃ CH ₂ CHC ^* H ₃ CH ₂ OCOC ₆ H ₆ OCO ₆ H ₆ O (CH ₂ ) ₅ SiCl ₃ (43) ClSi (CH ₃ ) ₂ OSi (CH ₃ ) ₂ OSi (CH ₃ ) ₂ OSi (CH ₃ ) ₂ Cl (44 _{) Cl 3 SiOSi (CH 3)} 2 OSi (CH 3) 2 OSi (CH 3) 2 OSi (CH 3) 2 OSiC
l ₃ where C ^* indicates an optically active irregular carbon.

When the surfactant molecules represented by the formulas (7) to (44) are used in combination, they have a linear carbon chain which polymerizes with each other as represented by the formulas (1) to (6). It is preferable to select one having a molecular length shorter than the molecular length of the molecule.

The surfactant molecules are added to an organic solvent, preferably a non-aqueous organic solvent, to form a chemisorption liquid.
As the organic solvent, a solvent containing an alkyl group, a fluorocarbon group, a carbon chloride group, a siloxane group, or the like can be used. More specifically, hexadecane containing an alkyl group, a fluorocarbon group, and / or In order to obtain a uniform monomolecular film, it is preferable to use a non-aqueous solvent such as Freon containing a carbon chloride group or hexamethyldisiloxane containing a siloxane group as a non-aqueous solvent.

As the substrate to be brought into contact with the chemical adsorption liquid, a transparent glass substrate or a resin substrate can be used. More specifically, various glass substrates such as soda lime silicate, borosilicate, and aluminosilicate, and various substrates such as polyester film can be used. A resin substrate can be used.

A series of chemical reactions that occur when a chemical adsorption solution containing surfactant molecules is brought into contact with the surface of a substrate to form a film on this surface are converted to a silane represented by the above formula (1). The case where the surfactant is a system surfactant and the hydrophilic group on the substrate surface is a hydroxyl group will be described below.

In this case, when the chemical adsorption liquid is brought into contact with the substrate surface, a dehydrochlorination reaction occurs between the chlorosilane group and the hydroxyl group, and the surfactant molecules are fixed on the substrate surface by siloxane bonds as shown in FIG. You.

Next, the substrate is taken out of the solution, washed well with a non-aqueous solvent, and exposed to air containing water. The water contained therein undergoes a dehydrochlorination reaction, and the surfactant molecules are mutually bonded via siloxane bonds as shown in FIG.

The film formed by such a process is as follows:
One end is a chemisorbed monolayer consisting of a group of molecules fixed to the surface of the substrate. This group of molecules is bonded to the substrate by a siloxane bond, and since the single molecules are bonded to each other, they are resistant to peeling. It has excellent characteristics.

FIG. 3 shows, together with a surfactant molecule having a linear carbon chain containing a diacetylene group (a) as shown by the formula (1) and having a chlorosilane group at the molecular end, the chemisorption solution containing CH ₃ SiCl ₃ is a short molecule, like the above-described method is a diagram showing a cross-section at the molecular level of the coating formed by washing with a non-aqueous solvent in contact with the substrate.

In FIG. 3, the linear carbon chain is controlled by a relatively short molecule so that the inclination with respect to the substrate is within a certain range. Such inclination control can improve accuracy by setting the direction of drainage of the non-aqueous solvent (the direction opposite to the substrate pulling direction 5) to a fixed direction. In addition, the film itself as shown in FIG. 3 in which the inclination of the linear carbon chain with respect to the substrate is controlled already has the alignment regulating force for the liquid crystal, and the present invention relates to the alignment of the liquid crystal alignment film. It has the aspect of further improving regulatory power.

A diacetylene group contained in a linear carbon chain whose inclination with respect to the substrate is controlled as shown in FIG. 3 can be polymerized while exhibiting a certain regularity even when polymerized by exposure. In this regular polymerization, typically, as illustrated in FIG. 4, diacetylene groups (a) are addition-polymerized to each other to form polydiacetylene (b). Since the angle of the linear carbon chain with respect to the substrate changes due to the polymerization of the diacetylene group, if the polymerization by exposure is selectively performed only in a predetermined region of the substrate, the portion where the diacetylene group has polymerized and the portion where the diacetylene group has not polymerized can be obtained. In between, irregularities that did not exist before the polymerization may occur. By utilizing this phenomenon, for example, a plurality of parallel unevennesses extending in a certain direction can be formed on the coating surface. These irregularities extending in the same direction are of high precision whose size is controlled at the molecular level, and are effective for improving the alignment regulating force for the liquid crystal.

In order to cause the linear carbon chains to be primarily oriented to cause the polymerization to occur regularly, it is preferable that the direction of drainage of the non-aqueous solvent used for washing the substrate is constant.
For example, when a substrate immersed in a non-aqueous solvent is pulled up and drained, it is preferable to pull up the substrate so that the substrate surface is parallel to the vertical direction as shown in FIG. The arrow shown in FIG. 3 is similar to the arrow 5 in FIG.
This corresponds to the substrate pulling direction. However, the method of draining the solvent is not limited to the illustrated method, and a gas such as dry air may be sprayed on the substrate surface from a certain direction to scatter and remove the non-aqueous solvent in the same direction. In this case, the direction in which the non-aqueous solvent is scattered and removed is the liquid draining direction.

As the organic solvent for washing the substrate, a non-aqueous solvent similar to the aforementioned organic solvent is preferable, and a non-aqueous solvent containing an alkyl group, a fluorocarbon group, a carbon chloride group, a siloxane group, etc. is preferably used. can do. Although not particularly limited, specifically, n-hexane, Freon 113, chloroform, hexamethylenediamine, or the like can be used.

The light-transmitting substrate used for exposing the film is preferably one in which a plurality of grooves having a width and a depth of 0.01 to 0.5 μm are formed in parallel with each other. Since the light-transmissive substrate having such irregularities can impart orientation to the liquid crystal, the irregular pattern itself can be transferred to the coating by exposure through the light-transmissive substrate. Thereby, the alignment regulating force with respect to the liquid crystal can be further improved.

When exposing through such a light-transmitting substrate, the light-transmitting substrate is arranged so that the direction of extension of the irregularities on the surface is not orthogonal to the direction of drainage of the non-aqueous non-aqueous solvent. Is preferred.

As the material of the light-transmitting substrate, various glasses and resins, specifically, soda lime silicate glass, quartz glass, polycarbonate resin, acrylic resin and the like can be used. The irregularities on the surface of the light-transmitting substrate are formed, for example, by rubbing with a rubbing cloth that has been conventionally used for forming a liquid crystal alignment film when a polycarbonate resin, an acrylic resin, or the like is used as a substrate such as a resin. it can. When a glass substrate is used, a resist film is formed on the surface of the glass plate,
It can be formed by exposing to a predetermined pattern and developing. Note that it is preferable that the substrate be further etched by chemical etching, plasma etching, sputter etching, or the like after the formation of the unevenness because the aspect ratio of the uneven groove can be increased.

FIG. 13 shows an embodiment of the liquid crystal display device of the present invention. This liquid crystal display device has a first substrate 23 having a first electrode group 21 mounted in a matrix and a transistor group 22 for driving the electrodes formed on the surface, a second electrode 25 and a color filter group. 24
And a second substrate 26 having a first electrode group 21 and a color filter group 24 facing each other.
It is fixed with a spacer 28 and an adhesive 29. A liquid crystal alignment film 27 according to the present invention is formed on a surface of the opposing surfaces of the first substrate 23 and the second substrate 26 including a region where electrodes, thin film transistors, color filters, and the like are formed. This liquid crystal alignment film 2
Numeral 7 is formed so as to cover the electrodes and the like, sandwiches the liquid crystal 30, and gives the liquid crystal 30 an orientation. Polarizing plates 31 and 32 are arranged on both sides of the panel constituted by the substrates 23 and 26 so as to sandwich the panel. An image is displayed in the direction of arrow A by driving each transistor using a video signal while illuminating the entire surface of the backlight 33 from the first substrate side of the device configured as described above.

The unevenness of the liquid crystal alignment film 27 has a special feature in that it is not formed by mechanical contact means such as rubbing, but is formed by means including exposure as described above. Therefore, it is possible to provide a liquid crystal display device in which local non-uniformity of liquid crystal alignment due to the presence of a surface step or a large area is suppressed.

[0053]

【Example】

(Example 1) First, a light-transmitting substrate suitable as an exposure mask was manufactured by the following example.

As shown in FIG. 7, the surface 12 of the acrylic transparent substrate 11 ultrasonically cleaned using a detergent is coated on a nylon cloth 13 (having a fiber diameter of 16 to 20) having a higher hardness than the acrylic plate.
μm, hair length 3mm), push 0.4mm,
Rubbing treatment was performed by rubbing the substrate surface in the same direction at a speed of 500 m / min. Observation of the substrate surface with a scanning electron microscope reveals that a number of irregularities oriented substantially in the same direction are formed, and the width and depth of the concave portions (groove portions) are generally in the range of 0.01 to 0.5 μm. there were. A nematic liquid crystal (ZLI4792, manufactured by Merck) was applied to the surface of the transparent exposure mask thus produced.
The liquid crystal was aligned clearly in the rubbing direction, and it was confirmed that the uneven surface had a liquid crystal alignment function.

Also, when a polycarbonate plate is used in place of the acrylic plate as the substrate and rubbed in the same manner as described above with a rubbing cloth for forming a liquid crystal alignment film, a large number of approximately 0.01 to 0.5 μm having a liquid crystal alignment effect can be obtained. A light-transmitting substrate (exposure mask) having on its surface an uneven shape oriented in the same direction could be produced.

For comparison, a translucent substrate was prepared in the same manner as described above except that a scotch sponge (manufactured by Sumitomo 3M Limited) was used instead of the nylon cloth. Although irregularities could be formed, the light transmittance deteriorated. The width and depth of the groove formed on the surface were generally in the range of 1 to 10 μm. When the nematic liquid crystal was applied to the surface of the substrate, the liquid crystal was partially aligned in a groove smaller than 0.5 μm formed by partially folding the groove, but was hardly aligned on other surfaces. .

Further, for comparison, irregularities were produced in the same manner as in the above example using a nylon cloth, except that the indentation amount was set to 0.05 mm. A few sparsely oriented grooves were formed. The width and depth of this groove are approximately 0.0
It was from 0.01 to 0.01 μm (1 to 10 nm). When the nematic liquid crystal was applied to the surface of the substrate, the liquid crystal was only sparsely aligned in the rubbing direction.

Example 2 Further, a light-transmitting substrate suitable as an exposure mask was manufactured according to the following example.

A PDUR-P is used as a resist on the surface of an A4 size white plate glass substrate ultrasonically cleaned using a detergent.
-14 (manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied to a thickness of 0.5 μm to form a resist film. As shown in FIG. 8, the entire surface of the resist film 16 is step-and-repeat exposed (100 mJ / cm ²⁾ by a KrF excimer laser exposure device using a 5 cm square chrome mask 18 having a 0.4 μm wide black and white pattern. ) Was repeatedly exposed.
In the exposure at this time, the mask was positioned so that the seams overlapped by several mm. Thereafter, the film was developed with a developing solution NMD3 (manufactured by Tokyo Ohka Kogyo Co., Ltd.) and rinsed with pure water. As shown in FIG. That is, 1250
Transparent substrate (exposure mask) having a resist thin film 17 having a number of lines / mm of diffraction grating formed on the surface of the glass plate 15
was gotten. When a nematic liquid crystal (ZLI4792, manufactured by Merck) was applied to the surface of the substrate, it was confirmed that the liquid crystal was aligned clearly along the stripes of the pattern. The liquid crystal was similarly aligned at the joint.

The same experiment was repeated except that the pattern pitch of the chrome mask transferred to the resist film was changed, and the results shown in FIG. 10 were obtained. As is clear from FIG.
It was confirmed that when grooves having a width and a depth of 0.5 μm or less were formed in the same direction, a surface shape having an excellent alignment control force for liquid crystal could be obtained. Further, when a groove of 0.01 μm or less was formed by a rubbing method, although it was confirmed that the liquid crystal was aligned, it was difficult to form this groove uniformly over the entire surface of the substrate, which lacked practicability. there were. In addition, T shown in FIG. 10 indicates a sample temperature at the time of evaluation of the alignment film.

Similar experiments were conducted using various substrate materials, and it was confirmed that borosilicate glass, quartz glass, polycarbonate resin, acrylic resin, and the like could be used as the substrate. Further, it was confirmed that ultraviolet light and far ultraviolet light can be used instead of the KrF excimer laser light as an exposure light source for forming a diffraction grating pattern having a pattern of 0.5 μm or less. The resist may be either a positive type or a negative type, as long as fine irregularities can be formed.

Further, after development, the substrate is further subjected to sputter etching using Ar gas or plasma etching using CF ₄ gas to increase the depth of the groove.
The aspect ratio of the groove could be increased, and the alignment regulating force could be improved. When a glass plate or a quartz plate was used as the base material, similar results were obtained by chemical etching using a hydrofluoric acid-based solution.

Example 3 Next, a liquid crystal alignment film was formed on the substrate surface using the exposure mask manufactured in the above example.

A glass substrate (having a large number of hydroxyl groups on the surface) having a transparent electrode formed on the surface was prepared and thoroughly washed and degreased. Next, in the yellow room, the following chemical formula (45)
A silane-based surfactant represented by the formula: CH ₃ SiCl ₃
Were mixed in a molar ratio of 1: 2, and this mixture was dissolved in a non-aqueous solvent so as to have a concentration of about 1% by weight to obtain a chemically adsorbed liquid. As the non-aqueous solvent at this time, hexadecane that was well dehydrated was used.

[0065]

Embedded image

As shown in FIG. 5, the glass substrate 1 was immersed in the chemical adsorption liquid 2 for about one hour in a dry atmosphere (relative humidity 30% or less). The glass substrate 1 is pulled up from the chemically adsorbing liquid 2 and washed with n-hexane 3 which is a well-dehydrated non-aqueous solvent as shown in FIG. 6, and then pulled up from the cleaning liquid with the substrate standing upright. And drained. Through this series of steps, a chemically adsorbed film having a thickness of about 2 nm was formed. Note that the adsorption liquid may be applied without immersion.

This chemically adsorbed film is made of a chlorosilane-based surfactant represented by the above chemical formula (45) and CH ₃ SiC
l ₃ is a chemically adsorbed monolayer formed by a dehydrochlorination reaction between a chlorosilane group contained in the glass substrate and a hydroxyl group on the surface of the glass substrate, and a linear hydrocarbon group contained in the monomolecular film is As in FIG. 3, the liquid crystal is primarily oriented in the draining direction of the non-aqueous solvent.

Thereafter, as shown in FIG.
Exposure mask 7 similar to the mask prepared in step 3 is placed close to the substrate so that the substrate pulling direction 5 and the rubbing direction 6 are close to, but not exactly perpendicular to, the substrate, and 365 nm ultraviolet light (UV light 8). and exposed at an intensity of 200 mJ / cm ² was thus transferring the pattern of the rubbing mask monolayer.

When the surface of the monomolecular film formed in this manner was observed using an AFM (atomic force scanning microscope), as shown in FIG. It was confirmed that many irregularities having a depth of about 0.5 μm and a molecular level were formed along the rubbing direction 6 of the mask.

When the angle between the substrate pulling direction 5 and the rubbing direction 6 was variously changed in the exposure step using the exposure mask 7, if the two were not exactly perpendicular to each other, the irregularities extending in substantially the same direction were obtained. Could be formed.

Further, a liquid crystal cell having a gap of 20 μm was assembled by using the two substrates so that the chemisorbed monomolecular films were opposed to each other to perform antiparallel alignment, and the nematic liquid crystal was injected to check the alignment state. did. The injected liquid crystal molecules had a pretilt angle of about 73 ° with respect to the substrate surface, and were substantially aligned along the rubbing pattern of the chemically adsorbed monomolecular film.

In the step of preparing a chemically adsorbed monomolecular film of the present example, a photosensitive polymer chemically adsorbed film could be formed if the washing step was omitted.

Further, by performing a plurality of steps of exposing a desired mask on the above-mentioned exposure mask and exposing the same, it is very easy to form a monomolecular liquid crystal alignment film having a different alignment direction in a pattern shape (ie, a multi-domain alignment film). Alignment film).

(Example 4) Next, a liquid crystal display device was manufactured using the liquid crystal alignment film manufactured in the above example.

First, as shown in FIG. 13, on a first substrate having a first electrode group mounted in a matrix and a transistor group for driving this electrode, and facing the first electrode group. A monomolecular liquid crystal alignment film was manufactured in the same manner as in Example 3 on a second substrate having a color filter group and a second electrode mounted as described above.

Next, the first and second substrates are positioned so that the electrodes face each other, and about 5
It was fixed so as to form a gap of μm. Then, after injecting the TN liquid crystal into the first and second substrates, a display element was completed by combining a polarizing plate.

In such a device, an image can be displayed in the direction of arrow A by driving each transistor using a video signal while illuminating the entire surface with a backlight.

As in this embodiment, when the above-mentioned films are formed as alignment films on the surface of the substrate on which the two electrodes facing each other are formed, a TN type liquid crystal display device can be provided.
In the method of this embodiment, the IPS type in which opposing electrodes other than the TN type liquid crystal display device are formed on one substrate surface is used.
(In-plane switching) type liquid crystal display device was also applicable. Fifth Embodiment In the light irradiation step of the fourth embodiment, a step of superposing and exposing a pattern-like mask for dividing each pixel into four in a checkered manner on the exposure mask is performed twice by changing the direction of the groove pattern. Thus, four portions having different alignment directions in a pattern in the same pixel could be provided. The use of the substrate on which the alignment film was formed could significantly improve the viewing angle of the liquid crystal display.

[0079]

As described above, according to the liquid crystal alignment film of the present invention, the uniformity of the liquid crystal alignment can be maintained well even on the surface of a panel having a large area or a substrate having a stepped portion, and furthermore, the peeling resistance can be improved. A highly effective film can be provided. According to the liquid crystal display device of the present invention, by using such a liquid crystal alignment film as a constituent element, the uniformity of the liquid crystal alignment film is not deteriorated even at a stepped portion on a panel or a substrate having a large area, and the The orientation can be kept good.

Further, according to the method for producing a liquid crystal alignment film of the present invention, a liquid crystal alignment film having good uniformity even at a stepped portion on a large-area panel or substrate surface can be efficiently and rationally manufactured. can do. According to this manufacturing method, the increase in the area of the panel and the step on the substrate surface do not basically affect the uniformity of the orientation, and the production efficiency does not basically decrease even when the area of the panel increases.

[Brief description of the drawings]

FIG. 1 is a diagram showing a state in which a surfactant molecule having a linear carbon chain and a chlorosilane group is chemically adsorbed on a substrate surface.

FIG. 2 is a diagram showing a state in which surfactant molecules chemically adsorbed on the substrate surface shown in FIG. 1 are bonded to each other.

FIG. 3 is a view showing one embodiment of a liquid crystal alignment film of the present invention.

FIG. 4 is a diagram showing a reaction example of polymerization of a linear carbon chain.

FIG. 5 is a cross-sectional view showing a state where the substrate is immersed in a chemical adsorption solution.

FIG. 6 is a cross-sectional view showing a state in which the state shifts to draining after the substrate is washed with an organic solvent.

FIG. 7 is a cross-sectional view illustrating a method for providing irregularities on a transparent substrate serving as an exposure mask.

FIG. 8 is a cross-sectional view showing another method for forming irregularities on a transparent substrate serving as an exposure mask.

FIG. 9 is a cross-sectional view showing one embodiment of a transparent substrate serving as an exposure mask.

FIG. 10 is a diagram showing a relationship between the size of an uneven pattern of an exposure mask and the degree of orientational order.

FIG. 11 is a perspective view showing one method of exposing a substrate with a transparent electrode using a light-transmitting substrate as a mask.

FIG. 12 is an embodiment of a transparent substrate on which a liquid crystal alignment film of the present invention is formed.

FIG. 13 is a sectional view showing one embodiment of the liquid crystal display device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transparent substrate 2 Chemical adsorption liquid 3 Organic solvent 4 Linear carbon chain orientation direction 5 Substrate lifting direction 6 Rubbing direction 7 Exposure mask 8 Light irradiation direction 9 Irregular pattern extension direction 10 Transparent electrode 11 Acrylic substrate 12 Acrylic substrate surface 13 Nylon Cloth 15 White glass plate 16 Resist coating 17 Resist coating 18 Chrome mask 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 28 Spacer 29 Adhesion Agent 30 liquid crystal 31, 32 polarizing plate

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[Procedure amendment]

[Submission date] May 28, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 17

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0023

[Correction method] Change

[Correction contents]

Further, in the method for manufacturing a liquid crystal alignment film, the surfactant molecules having a straight chain, a molecular terminal, silicon-containing selected Kuroroshi drill group, the alkoxysilyl Lil group and an isocyanate silyl group Preferably, it contains a group. This is because a chemically adsorbed film having a high peeling resistance can be efficiently produced.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0030

[Correction method] Change

[Correction contents]

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION The liquid crystal alignment film of the present invention has
Surfactant having a linear carbon chain fixed to the surface of a plate
Contains molecules. As such a surfactant molecule
Represents a carbon trifluoride group at the terminal or a part of the linear carbon chain.
(-CF_Three ), Methyl group (-CH_Three ), Vinyl group (-C
H = CH_Two ), Allyl group (-CH = CH-), acetylene
Group (carbon-carbon triple bond), phenyl group (-C
₆H _Five ),PhenyleneGroup (-C₆H_Four−), Halogen group, a
Alkoxy group (-OR; R represents an alkyl group, especially carbon
Alkyl groups in the range of numbers 1 to 3 are preferred. ), Cyano group
(-CN), amino group (-NH _Two ), Hydroxyl group (-O
H), carbonyl group (= CO), oxycarbonyl group
(-COO-), a carboxyl group (-COOH) and
At least one selected from isocyanate groups (—NCO)
Can mention surfactant molecules containing one substituent
You. Chlorosiloxane is a surfactant molecule.LilGroup, Arco
SixiLilGroup and isocyanateLilSelected from groups
Surfactant molecules having a substituent at the molecular end are preferred.
No.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0034

[Correction method] Change

[Correction contents]

The surfactant molecules which can be suitably used as shown in the above formulas (1) to (6) are preferably used by mixing with other types of surfactants. Examples of the surfactant molecule include surfactant molecules represented by the following formulas (7) to (20). (7) CH ₃ (CH ₂ ) _n SiCl ₃ (8) CH ₃ (CH ₂ ) _p Si (CH ₃ ) ₂ (CH ₂ ) _q SiCl ₃ (9) CH ₃ COO (CH ₂ ) _m SiCl ₃ (10 ) C ₆ H ₅ (CH ₂ ) _n SiCl ₃ (11) CN (CH ₂ ) _n SiCl ₃ (12) Cl ₃ Si (CH ₂ ) _s SiCl ₃ (13) Cl ₃ Si (CH ₂ ) ₂ (CF ₂ ) _t (CH ₂ ) ₂ SiCl ₃ (14) Ha (CH ₂ ) _u Si (OCH ₃ ) ₃ (15) CH ₃ (CH ₂ ) _n Si (NCO) ₃ (16) CH ₃ (CH ₂ ) _p Si (CH ₃ ) ₂ (CH ₂ ) _q Si (OCH ₃ ) ₃ (17) HOOC (CH ₂ ) _m Si (OCH ₃ ) ₃ (18) H ₂ N (CH ₂ ) _m Si (OCH ₃ ) ₃ (19 ) C ₆ H ₅ (CH ₂ ) _n Si (NCO) ₃ (20) CN (CH ₂ ) _n Si (OC ₂ H ₅ ) ₃ where Ha represents a halogen atom such as chlorine, bromine, iodine, fluorine, etc. m is an integer of 0 or more, preferably 7
N is an integer of 0 or more, preferably an integer of 0 to 24, s is an integer of 0 or more, preferably an integer of 3 to 24, and t is 0 or more. It is an integer, preferably an integer of 1 to 10. u is an integer of 0 or more, and preferably an integer of 1 to 24.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0035

[Correction method] Change

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More specifically, there may be mentioned surfactant molecules represented by the following formulas (21) to (44). (21) Br (CH ₂ ) ₈ SiCl ₃ (22) CH ₂ = CH (CH ₂ ) ₁₇ SiCl ₃ (23) CH ₃ (CH ₂ ) ₈ -CO- (CH ₂ ) ₁₀ SiCl ₃ (24) CH ₃ (CH ₂ ) ₅ -COO- (CH ₂ ) ₁₀ SiCl ₃ (25) CH ₃ (CH ₂ ) ₈ -Si (CH ₃ ) _2- (CH ₂ ) ₁₀ SiCl ₃ (26) CH ₃ (CH ₂ ) ₁₇ SiCl ₃ (27) CH ₃ (CH ₂ ) ₅ Si (CH ₃ ) ₂ (CH ₂ ) ₈ SiCl ₃ (28) CH ₃ COO (CH ₂ ) ₁₄ SiCl ₃ (29) C ₆ H ₅ (CH ₂ ) ₈ SiCl ₃ (30) CN (CH ₂ ) ₁₄ SiCl ₃ (31) Cl ₃ Si (CH ₂ ) ₈ SiCl ₃ (32) Cl ₃ Si (CH ₂ ) ₂ (CF ₂ ) ₄ (CH ₂ ) ₂ SiCl ₃ ( 33) Cl ₃ Si (CH ₂ ) ₂ (CF ₂ ) ₆ (CH ₂ ) ₂ SiCl ₃ (34) CF ₃ CF ₂ (CF ₂ ) ₇ (CH ₂ ) ₂ SiCl ₃ (35) (CF ₃ ) ₂ CHO (CH ₂ ) ₁₅ Si (CH ₃ ) ₂ Cl (36) CF ₃ CF ₂ (CH ₂ ) ₂ Si (CH ₃ ) ₂ (CH ₂ ) ₁₅ SiCl ₃ (37) CF ₃ (CF ₂ ) ₄ (CH ₂ ) ₂ Si (CH ₃ ) ₂ (CH ₂ ) ₉ SiCl ₃ (38) CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ Si (CH ₃ ) ₂ (CH ₂ ) ₉ SiCl ₃ (39) CF ₃ COO ( CH ₂ ) ₁₅ SiCH ₃ Cl ₂ (40) CF ₃ (CF ₂ ) ₅ (CH ₂ ) ₂ SiCl ₃ (41) CH ₃ CH ₂ C ^* HC H ₃ CH ₂ OCO (CH ₂ ) ₁₀ SiCl ₃ (42) CH ₃ CH ₂ C ^* HC H ₃ CH ₂ OCOC ₆ H ₄ OCO C ₆ H ₄ O (CH ₂ ) ₅ SiCl ₃ (43) ClSi (CH ₃ ) ₂ OSi (CH ₃ ) ₂ OSi (CH ₃ ) ₂ OSi (CH ₃ ) ₂ Cl ( _{44) Cl 3 SiOSi (CH 3} ) 2 OSi (CH 3) 2 OSi (CH 3) 2 OSi (CH 3) 2 OSiC
l ₃ However, C ^* denotes an asymmetric carbon of the optically active.

[Procedure amendment 6]

[Document name to be amended] Drawing

[Correction target item name] Fig. 4

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FIG. 4

[Procedure amendment 7]

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[Procedure amendment 8]

[Document name to be amended] Drawing

[Correction target item name] FIG.

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FIG. 13

Claims (24)

[Claims] Claims: 1. A coating comprising a group of molecules having one end chemically adsorbed on the surface of a substrate, the group of molecules including a molecule having a linear carbon chain, and at least a part of the linear carbon chain. A liquid crystal alignment film characterized by being selectively polymerized with each other. 2. The liquid crystal alignment film according to claim 1, wherein the inclination of the linear carbon chain with respect to the substrate is controlled to a constant angle by polymerization of the linear carbon chain. 3. The molecule group includes a molecule shorter than a molecule having a linear carbon chain, and the presence of the molecule controls the inclination of the linear carbon chain with respect to the substrate to a constant angle,
At least a part of the linear carbon chain selectively polymerizes with each other, so that the inclination with respect to the substrate increases or decreases from the angle, and a region where the linear carbon chain polymerizes due to the increase or decrease. 3. The liquid crystal alignment film according to claim 2, wherein a convex portion or a concave portion is formed. 4. The substrate according to claim 1, wherein a region where the linear carbon chain is polymerized forms a plurality of substantially parallel lines through a region where the linear carbon chain is not polymerized. Item 4. The liquid crystal alignment film according to item 2 or 3. 5. The liquid crystal alignment film according to claim 1, wherein one end of a molecule having a linear carbon chain is fixed to the surface of the substrate via a siloxane bond. 6. The liquid crystal alignment film according to claim 1, wherein the molecules constituting the group of molecules are bonded to each other via a siloxane bond. 7. A chemical adsorption solution is brought into contact with the surface of the substrate to chemically react a surfactant molecule having a linear carbon chain contained in the chemical adsorption solution with a hydrophilic group on the surface. A step of fixing one end of a molecule to the surface, and a step of imparting an orientation to a substrate to at least a part of the linear carbon chain by selectively exposing a film made of a group of molecules including the molecule. A method for producing a liquid crystal alignment film, comprising: 8. The step of imparting orientation to at least a part of the linear carbon chain with respect to the substrate comprises polymerizing the linear carbon chain, thereby making the inclination of the linear carbon chain with respect to the substrate a constant angle. The method for producing a liquid crystal alignment film according to claim 7, which is a step of controlling the liquid crystal alignment film. 9. A tilt of the linear carbon chain with respect to the substrate is kept constant by fixing one end of a molecule having a molecular length shorter than the surfactant molecule to a surface of the substrate together with a surfactant molecule having a linear carbon chain. And by selectively polymerizing at least a portion of the linear carbon chains with each other, the angle of the polymerized linear carbon chains with respect to the substrate is increased or decreased from the angle, and the increased 9. The method for producing a liquid crystal alignment film according to claim 8, wherein a region where the linear carbon chain is polymerized by the reduction forms a convex portion or a concave portion. 10. After the step of immobilizing one end of a surfactant molecule having a linear carbon chain on the surface, and before the step of exposing a film composed of a group of molecules containing the molecule, the step of 9. The method for producing a liquid crystal alignment film according to claim 7, comprising a step of cleaning the surface with an organic solvent. 11. The method according to claim 10, wherein in the step of washing with the organic solvent, the linear carbon chains are oriented in the predetermined direction by draining the organic solvent from the surface of the substrate in a predetermined direction. 3. The method for producing a liquid crystal alignment film according to item 1. 12. An organic solvent is drained from a surface of the substrate in a predetermined direction to control the inclination of the linear carbon chain with respect to the substrate at a constant angle. By selectively polymerizing at least a portion of the chains with each other, the angle of the polymerized linear carbon chain to the substrate is increased or decreased from the angle, and the increase or decrease causes the linear carbon chain to polymerize. The method for manufacturing a liquid crystal alignment film according to claim 11, wherein the region where the liquid crystal alignment film is formed forms a protrusion or a recess. 13. A non-aqueous organic solvent containing at least one selected from an alkyl group, a fluorocarbon group, a carbon chloride group and a siloxane group as the organic solvent.
13. The method for producing a liquid crystal alignment film according to any one of 0 to 12. 14. Exposure to a surface through a light-transmitting substrate having a plurality of irregularities extending in substantially the same direction causes a region where a linear carbon chain is polymerized on the surface of the substrate to form a linear carbon. 14. The method for producing a liquid crystal alignment film according to any one of claims 8 to 13, wherein a plurality of parallel lines are formed through regions where the chains are not polymerized. 15. The method for producing a liquid crystal alignment film according to claim 14, wherein the exposure is performed via a light-transmitting substrate having a width and depth of the concave and convex portions on the surface of 0.01 to 0.5 μm. 16. The method for producing a liquid crystal alignment film according to claim 14, wherein light that reaches the coating film via the light-transmitting substrate is diffracted by unevenness of the light-transmitting substrate. 17. The surfactant molecule according to claim 7, wherein the surfactant molecule having a linear carbon chain contains a silicon-containing group selected from a chlorosilane group, an alkoxysilane group, and an isocyanatosilane group at a molecular terminal. The method for producing a liquid crystal alignment film according to the above. 18. The surfactant molecule according to claim 8, wherein the surfactant molecule having a linear carbon chain contains a photopolymerizable functional group in the linear carbon chain.
18. The method for producing a liquid crystal alignment film according to any one of items 17. 19. The method according to claim 18, wherein the photopolymerizable functional group is a diacetylene group. 20. A chemical adsorption solution is brought into contact with the surface of the substrate to chemically react a surfactant molecule having a linear carbon chain contained in the chemical adsorption solution with a hydrophilic group on the substrate surface. A step of fixing one end of the molecule to the surface; a step of washing the surface by draining the organic solvent in contact with the surface in a predetermined direction; and a plurality of irregularities on the surface in substantially the same direction. A step of arranging a light-transmitting substrate extending in such a manner that the direction in which the irregularities extend is not orthogonal to the direction of the liquid drainage, and exposing a coating made of a molecule group including the molecule through the light-transmitting substrate. And a method for producing a liquid crystal alignment film. 21. A liquid crystal display device having a liquid crystal alignment film formed on at least one of opposing surfaces and arranged so as to maintain a predetermined interval.
In a liquid crystal display device including two substrates and a liquid crystal sandwiched between the two substrates, the alignment of which is controlled by the liquid crystal alignment film, the liquid crystal alignment film has a group of molecules whose one end is chemically adsorbed on the surface of the substrate. A liquid crystal display device comprising: a coating comprising: a group of molecules including a molecule having a linear carbon chain, wherein at least a part of the linear carbon chain is selectively polymerized with each other. 22. The polymerization of a linear carbon chain,
22. The liquid crystal display device according to claim 21, further comprising a liquid crystal alignment film in which the inclination of the linear carbon chain with respect to the substrate is controlled at a constant angle. 23. A step is formed on a part of the surface of the substrate by forming at least one thin film member selected from an electrode, a color filter, and a thin film transistor, and a liquid crystal alignment film is formed in a region including the step. 23. The liquid crystal display device according to claim 21, wherein 24. The liquid crystal display device according to claim 21, wherein the liquid crystal alignment film includes a plurality of regions having different alignment directions.