JP2006322987A - Liquid crystal device, method for manufacturing same, and projection type display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal device whose excellent aligning property is combined with high reliability. <P>SOLUTION: The liquid crystal device is constructed with a pair of substrates 10, 20 having a liquid crystal 50 interposed in between. Out of the pair of substrates, at least one substrate 10 has an alignment layer 1 on the surface of the liquid crystal 50 side. The alignment layer 1 comprises a plurality of layers 1A, 1B, 1C having a base material in common. The plurality of layers 1A, 1B, 1C are constructed in such a way that a proportion of an organic material component to the base material increases from its value in the layer 1A of the substrate 10 side to that in the layer 1C of the liquid crystal 50 side. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid crystal device, a method for manufacturing the liquid crystal device, and a projection display device.

In general, a liquid crystal device used as a light valve of a liquid crystal projector (projection display device) or a display such as a mobile phone has an alignment film for controlling the alignment of liquid crystal molecules on the outermost surface of a substrate sandwiching the liquid crystal layer. Is formed. As this alignment film, a film obtained by rubbing an organic film such as polyimide (organic alignment film) is widely used (for example, see Patent Document 1).
Japanese Patent Laid-Open No. 9-244029

  However, such an organic alignment film is excellent in the alignment force, but is weak against heat and light, and has a problem that the alignment force gradually decreases with long-term use. For example, when it is mounted on a projector that is irradiated with high-intensity light, the alignment film is gradually modified by light or heat from the light source, and liquid crystal molecules may not be aligned in a desired alignment direction. Further, when such light deterioration occurs, the decomposition product may adversely affect the performance of the liquid crystal.

  As a means for solving this problem, a technique using an alignment film (inorganic alignment film) formed of an inorganic material for the alignment film has been proposed. The inorganic alignment film is generally formed by oblique deposition. However, although the inorganic alignment film is excellent in light resistance and heat resistance as compared with an organic alignment film composed of an organic material, there is a problem that the ability to align liquid crystal molecules is low. For this reason, in a liquid crystal device using an inorganic alignment film, there is a risk of causing uneven alignment due to insufficient alignment force, a decrease in contrast, and the like.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a liquid crystal device having both good alignment characteristics and high reliability, and a method for manufacturing the same. It is another object of the present invention to provide a projection type display device having both good display characteristics and high reliability by including such a liquid crystal device.

In order to solve the above problems, a liquid crystal device according to the present invention is a liquid crystal device in which a liquid crystal is sandwiched between a pair of substrates, and the liquid crystal side surface of at least one of the pair of substrates is disposed on the surface on the liquid crystal side. The alignment film is composed of a plurality of layers having a common inorganic material component, and the plurality of layers has a ratio of the organic material component in the common inorganic material component on the substrate side. It is configured to increase from the layer toward the liquid crystal side layer.
According to this configuration, since the ratio of the organic material component in the alignment film increases from the substrate side toward the liquid crystal side, only the portion in contact with the liquid crystal is aligned while increasing the ratio of the inorganic material component in the entire alignment film. It can be set as a composition with a high ratio of the organic-material component with a favorable characteristic. Therefore, it is possible to provide a liquid crystal device having both good alignment characteristics and high reliability. In general, since alignment characteristics and reliability are in a trade-off relationship, both characteristics cannot be realized at the same time with the same alignment film. However, in the present invention, these two characteristics are separated from each other in the alignment film. By realizing with layers, it is possible to satisfy both characteristics simultaneously.

In the present invention, among the plurality of layers, the layer disposed closest to the substrate is constituted by an inorganic alignment film mainly composed of an inorganic material component, and the layer disposed closest to the liquid crystal is an organic material. It can be constituted by an organic alignment film mainly composed of components. In this case, it is preferable that the inorganic alignment film is mainly composed of the same inorganic material component as the material component of the substrate.
According to this configuration, a liquid crystal device with higher reliability and better alignment characteristics can be provided. Further, when the inorganic alignment film is mainly composed of the same inorganic material component as that of the substrate, the adhesion between the inorganic alignment film and the substrate is improved, and a more reliable liquid crystal device can be provided. .

  Here, “mainly” means that an inorganic material component and an organic material component are compared, and one is more than the other. For example, an inorganic alignment film contains more inorganic material components than an organic material component, and an organic alignment film contains more organic material components than an inorganic material component. The ratio between the inorganic material component and the organic material component is set to an appropriate value from the viewpoint of the intensity of light incident on the alignment film, the required alignment characteristics, light resistance, and the like. In the present invention, even an alignment film containing an organic material component in part is called an inorganic alignment film if it is mainly composed of an inorganic material component (that is, if it is an inorganic-rich alignment film). Even if the alignment film contains an inorganic material component in part, it is called an organic alignment film if it is mainly composed of an organic material component (that is, if it is an organic-rich alignment film).

In the present invention, the organic material component of the alignment film is composed of an organometallic material, and the organometallic material has an affinity imparting group in its molecule for improving the affinity with the liquid crystal, It may have an orientation-imparting group that controls the orientation of the liquid crystal.
According to this configuration, it is possible to provide a liquid crystal device having excellent light resistance and excellent alignment characteristics.

In the present invention, the affinity imparting group is preferably at least one of a vinyl group, an alkylene group, and a cyanoalkyl group.
According to this configuration, the affinity with the liquid crystal can be improved more effectively, and the liquid crystal can be arranged in a more stable state.

In the present invention, the orientation-imparting group is preferably at least one of a phenyl group, a substituted phenyl group, a phenylalkyl group, a substituted phenylalkyl group, and a branched alkyl group having 3 to 12 carbon atoms.
According to this configuration, the alignment direction and the pretilt angle of the liquid crystal can be more effectively made desired, and more excellent alignment characteristics can be exhibited.

In the present invention, the alignment film may be formed by a sol-gel method.
According to this configuration, since the alignment film is formed using a sol-gel method that is a liquid phase method, the process can be simplified as compared with a conventional method using a vapor phase method such as oblique deposition. Can do. On the other hand, a method other than the sol-gel method can be used in that the same liquid phase method is used. For example, as shown in Patent Document 1, it is possible to dissolve the alignment film material in a solvent and recoat it through a nozzle. In this case, however, re-dissolution with the solvent at the boundary portion of the repainted layer. This causes a problem that a precise layer structure cannot be formed. However, if the sol-gel method is used as in the present invention, such a problem of re-dissolution does not occur, so that the inorganic alignment film and the organic alignment film can be arranged with high accuracy.

The method of manufacturing a liquid crystal device according to the present invention is a method of manufacturing a liquid crystal device in which a liquid crystal is sandwiched between a pair of substrates, and an alignment film is provided on the liquid crystal side surface of at least one of the pair of substrates. A step of forming the alignment film, wherein the step of forming the alignment film includes a plurality of layers having a common base material in which a ratio of an organic material component in the base material is changed from the substrate side layer to the liquid crystal side layer. The method includes a step of sequentially forming the layers so as to increase in size.
According to this method, while increasing the ratio of the inorganic material component of the entire alignment film, only the portion in contact with the liquid crystal can have a composition with a high ratio of the organic material component having good alignment characteristics. Therefore, it is possible to provide a liquid crystal device having both good alignment characteristics and high reliability.

In the present invention, among the plurality of layers, the layer disposed closest to the substrate is formed of an inorganic alignment film mainly composed of an inorganic material component, and the layer disposed closest to the liquid crystal is an organic material. It can be formed by an organic alignment film mainly composed of components. In this case, it is preferable that the inorganic alignment film is mainly composed of the same inorganic material component as the material component of the substrate.
According to this method, a liquid crystal device with higher reliability and better alignment characteristics can be provided. Further, when the inorganic alignment film is mainly composed of the same inorganic material component as that of the substrate, the adhesion between the inorganic alignment film and the substrate is improved, and a more reliable liquid crystal device can be provided. .

In the present invention, the step of forming the alignment film includes the step of polycondensing a metal alkoxide, an affinity imparting group for improving the affinity with the liquid crystal in the molecule, and the orientation imparting for controlling the alignment of the liquid crystal. A step of preparing an alignment film-forming liquid having a group, and a step of curing the alignment film-forming liquid to form the alignment film.
This method is generally called a sol-gel method. The sol-gel method is a relatively new method for producing ceramics. In the sol-gel method, a gel, which is a jelly-like solid, is produced by starting from a solution called a sol and undergoing hydrolysis and condensation polymerization. And by performing heat processing, the solvent left inside is removed and further densification is promoted to obtain ceramics. For this reason, the process temperature can be kept low compared to a method in which the raw material is melted and re-solidified, and the manufacturing apparatus is downsized compared to the case where a vapor phase method such as oblique deposition is used. In addition, the process can be simplified. Further, since the sol-gel method is a production method from a liquid phase, atoms can be mixed homogeneously at a molecular level, and the composition can be easily controlled.
In addition, since it can be manufactured at a low temperature using a chemical reaction, it is possible to combine an organic material and an inorganic material. The organic / inorganic composite material is a novel material that combines the characteristics of both organic and inorganic materials. In the present invention, the organic material has good orientation, which is a characteristic of organic materials, and high reliability, which is a characteristic of inorganic materials. It is possible to easily form a novel alignment film having both.

In the present invention, the step of forming the alignment film aligns the surface of the plurality of layers arranged on the substrate side before forming the layer arranged on the liquid crystal side most. The process (rubbing process etc.) can be included.
According to this method, since the layer subjected to the alignment treatment does not contact the liquid crystal, the influence of the alignment treatment (such as ravis) does not adversely affect the display characteristics. On the other hand, since the layer in contact with the liquid crystal contains a lot of organic material components, a film is formed with an alignment ability due to the influence of the alignment treatment of the base, even if the alignment film forming liquid is simply applied. . For this reason, sufficient orientation ability can be exhibited even if the surface is not subjected to orientation treatment again.

In the present invention, the alignment film-forming liquid contains a hydrolyzate of a silane compound having an organic group and a hydrolyzate of tetraalkoxysilane, and the silane compound contains carbon atoms constituting the organic group. Those directly bonded to silicon atoms can be used.
Thereby, it is possible to provide an alignment film having excellent light resistance and excellent alignment characteristics (function of regulating the alignment state of the liquid crystal material).

In the present invention, the organic group is preferably a functional group containing an aromatic ring.
Thereby, the affinity with the liquid crystal molecules is further improved, and the alignment state of the liquid crystal molecules can be more effectively regulated.

In the present invention, the silane compound preferably has an alkoxyl group or a halogen group in addition to the organic group.
Thereby, hydrolysis of a silane compound can be performed easily.

A projection display device according to the present invention includes the above-described liquid crystal device according to the present invention or the liquid crystal device manufactured by the above-described manufacturing method according to the present invention.
According to this configuration, it is possible to provide a projection display device that has both good display characteristics and high reliability.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In the following embodiments, an active matrix liquid crystal device including a thin film transistor (TFT) as a pixel switching element will be described as an example. This liquid crystal device can be suitably used, for example, as a light valve (light modulation means) of a projection display device. In each drawing used in the following description, the scale is different for each layer and each member so that each layer and each member can be recognized on the drawing.

[First Embodiment]
FIG. 1 is a plan view of the liquid crystal device 100 according to the present embodiment as viewed from the counter substrate side together with each component, and FIG. 2 is a cross-sectional view taken along the line HH ′ of FIG. FIG. 3 is a diagram showing an equivalent circuit of various elements and wirings in a plurality of pixels formed in a matrix in the image display area of the liquid crystal device.

[Overall configuration of liquid crystal display]
As shown in FIGS. 1 and 2, in the liquid crystal display device 100 of the present embodiment, the TFT array substrate 10 and the counter substrate 20 are bonded together by a sealing material 52, and the liquid crystal is in a region partitioned by the sealing material 52. Layer 50 is encapsulated. A light shielding film (peripheral parting) 53 made of a light shielding material is formed in a region inside the region where the sealing material 52 is formed. A data line driving circuit 201 and an external circuit mounting terminal 202 are formed along one side of the TFT array substrate 10 in a region outside the sealing material 52, and the scanning line driving circuit is formed along two sides adjacent to the one side. 204 is formed. On the remaining side of the TFT array substrate 10, a plurality of wirings 205 are provided for connecting between the scanning line driving circuits 204 provided on both sides of the image display area. In addition, an inter-substrate conductive material 206 for providing electrical continuity between the TFT array substrate 10 and the counter substrate 20 is disposed at a corner portion of the counter substrate 20.

Instead of forming the data line driving circuit 201 and the scanning line driving circuit 204 on the TFT array substrate 10, for example, a TAB (Tape Automated Bonding) substrate on which a driving LSI is mounted and a peripheral portion of the TFT array substrate 10 The terminal group formed in the above may be electrically and mechanically connected via an anisotropic conductive film.
In the liquid crystal display device 100, the type of liquid crystal mode to be used, that is, TN (Twisted Nematic) mode, VA (Vertical Alignment) mode, OCB (Optically Compensated Bend) mode, IPS (In Plain Switching) mode, STN (STN) Depending on the operation mode such as the Super Twisted Nematic mode and the normally white mode / normally black mode, a phase difference plate, a polarizing plate, and the like are arranged in a predetermined direction, but the illustration is omitted here.

  In the image display area of the liquid crystal display device 100 having such a structure, as shown in FIG. 3, a plurality of dots 100a are arranged in a matrix, and each of these dots 100a has a pixel switching area. TFT 30 is formed, and a data line 6 a for supplying pixel signals S 1, S 2,..., Sn is electrically connected to the source of the TFT 30. Pixel signals S1, S2,..., Sn to be written to the data lines 6a may be supplied line-sequentially in this order, or may be supplied for each group to a plurality of adjacent data lines 6a. . Further, the scanning line 3a is electrically connected to the gate of the TFT 30, and the scanning signals G1, G2,..., Gm are applied to the scanning line 3a in a pulse-sequential manner in this order at a predetermined timing. It is configured. The pixel electrode 9 is electrically connected to the drain of the TFT 30, and the pixel signal S1, S2,..., Sn supplied from the data line 6a is obtained by turning on the TFT 30 as a switching element for a certain period. Write to each pixel at a predetermined timing. The pixel signals S1, S2,..., Sn written in the liquid crystal via the pixel electrode 9 in this way are held for a certain period with the counter electrode 21 of the counter substrate 20 shown in FIG. Further, in order to prevent the held pixel signals S1, S2,..., Sn from leaking, a storage capacitor 60 is added in parallel with the liquid crystal capacitor formed between the pixel electrode 9 and the counter electrode 21. Reference numeral 3 b denotes a capacity line constituting the storage capacity 60.

Next, the structure of the liquid crystal device 100 will be described with reference to FIG. 4A is a schematic diagram illustrating a cross-sectional structure of the liquid crystal device 100, and FIG. 4B is a schematic diagram illustrating a structure of the alignment film.
In the liquid crystal display device 100 of the present embodiment, as shown in FIG. 4A, a liquid crystal layer 50 is sandwiched between a TFT array substrate 10 and a counter substrate 20 made of transparent glass or the like that are opposed to each other up and down. It has a basic structure.

  On the inner surface of the TFT array substrate 10, a pixel electrode 9 made of a transparent conductive film such as TFT 30 and ITO is provided for each pixel 100a arranged in a matrix. Actually, wiring lines such as the data line 6a and the scanning line 3a are formed, but these are not shown in FIG. 4A. An alignment film 1 is provided on the entire inner surface of the TFT array substrate 10 so as to cover the TFTs 30 and the pixel electrodes 9.

  A light shielding film 23 is provided on the inner surface of the counter substrate 20. The light-shielding film 23 is provided in a lattice shape along the edge of each pixel 100a where the TFT 30, wiring, etc. (data line 6a, scanning line 3a, etc.) are formed. A region where the illumination light is blocked by the light shielding film 23 is a non-illumination region, and a region where the illumination light is transmitted through the opening of the light shielding film 23 is an illumination region. Only the illumination area contributes to the display. On the inner surface of the counter substrate 20, a counter electrode 21 made of a transparent conductive film such as ITO is provided on the entire surface so as to cover the light shielding film 23, and further, an alignment film is formed on the entire image display region so as to cover the counter electrode 21. 2 is provided.

  A liquid crystal layer 50 is held between the substrates 10 and 20. As the liquid crystal material constituting the liquid crystal layer 50, any liquid crystal material that can be aligned such as nematic liquid crystal and smectic liquid crystal may be used. In the case of a TN liquid crystal panel using nematic liquid crystal, for example, phenyl Examples include a cyclohexane derivative liquid crystal, a biphenyl derivative liquid crystal, a biphenylcyclohexane derivative liquid crystal, a terphenyl derivative liquid crystal, and a phenylcyclohexylcyclohexane derivative liquid crystal. Furthermore, liquid crystal molecules in which a fluorine-based substituent such as a monofluoro group, a difluoro group, a trifluoro group, a trifluoromethyl group, a trifluoromethoxy group, or a difluoromethoxy group is introduced into these nematic liquid crystal molecules are also included.

The alignment films 1 and 2 each include a plurality of layers having different ratios of organic material components.
FIG. 4B is a schematic diagram showing a cross-sectional structure of the alignment film. In FIG. 4B, only the structure of the alignment film 1 is shown, but the structure of the alignment film 2 is similar to this.

As shown in FIG. 4B, the alignment film 1 has a three-layer structure in which a first alignment layer 1A, a second alignment layer 1B, and a third alignment layer 1C are sequentially stacked from the substrate 10 side. The alignment layers 1A to 1C are continuously formed by a sol-gel method, and the alignment films 1A to 1C have a common base material. For this base material, an inorganic material such as SiO _{2 which} is the same as the material component of the substrate 10 is used. The ratio of the organic material component in the base material of each of the alignment layers 1A to 1C is configured to increase from the alignment layer 1A on the substrate 10 side toward the alignment layer 1C on the liquid crystal 50 side. In the present embodiment, the first alignment layer 1A and the second alignment layer 1B are each composed of an inorganic-rich alignment film (hereinafter referred to as an inorganic alignment film) mainly composed of inorganic material components, and the third alignment layer. 1C is composed of an organic-rich alignment film (hereinafter referred to as an organic alignment film) mainly composed of organic material components. Specifically, the first alignment layer 1A is composed of only the inorganic material component that is the base material, and the second alignment layer 1B is an inorganic material that includes 60% of the inorganic material component that is the base material and 40% of the organic material component. The third alignment layer 1C is composed of an inorganic / organic composite material containing 20% of an inorganic material component as a base material and 80% of an organic material component. Thus, by increasing the ratio of the organic material component in the alignment film 1 from the substrate 10 side toward the liquid crystal 50 side, the ratio of the inorganic material component in the entire alignment film is improved while improving the alignment characteristics of the alignment film surface. Can also be increased. In addition, since the alignment layer 1A on the substrate 10 side has a composition centered on the inorganic material, the adhesion between the alignment film 1 and the substrate 10 is also good.

  Here, “mainly” means that an inorganic material component and an organic material component are compared, and one is more than the other. For example, an inorganic alignment film contains more inorganic material components than an organic material component, and an organic alignment film contains more organic material components than an inorganic material component. The ratio of the inorganic material component to the organic material component is set to an appropriate value from the viewpoint of the intensity of light incident on each alignment film, the required alignment characteristics, light resistance, and the like.

These alignment layers 1 </ b> A to 1 </ b> C are composed of one or both of an inorganic material component and an organometallic material. In this embodiment, it is assumed that these alignment layers 1A to 1C are formed by a sol-gel method. Therefore, as the organometallic material, a general formula: M (OR) _n (M: metal, R : Metal alkoxide represented by alkyl group), but other organometallic materials may be used.

As the metal M, various materials such as Si, Al, Ti, In, Zn, Sn, V, Sr, and La can be used. Moreover, as the alkyl group R, a C1-C5 alkyl group can be mentioned as a representative example.
In this embodiment, the metal M is Si, and an organosilicon material is used as the organometallic material.

  The organosilicon material is composed of a composite material of polysiloxane and an organic compound. This organosilicon material has excellent chemical stability, and has excellent light resistance as compared to an alignment film composed only of a conventional organic material. Among such organosilicon materials, in the present embodiment, in particular, in the molecule, an affinity imparting group that improves the affinity with liquid crystal as a functional group, and an orientation imparting group that controls the alignment state of the liquid crystal. Are used.

  Examples of the affinity imparting group include a vinyl group, an alkylene group, a cyanoalkyl group, a phenyl group, a substituted phenyl group, and an alkylidene group. In particular, those having at least one or more of vinyl, alkylene, alkylidene and cyanoalkyl groups are preferred. Thereby, high affinity is obtained.

  Examples of the orientation-imparting group include a phenyl group, a substituted phenyl group, a phenylalkyl group, a substituted phenylalkyl group, and a branched alkyl group having 3 to 12 carbon atoms. In particular, those having at least one or more of a phenyl group, a substituted phenyl group, a phenylalkyl group, a substituted phenylalkyl group, and a branched alkyl group having 3 to 12 carbon atoms are preferred. Thereby, the alignment direction of liquid crystal molecules becomes more uniform, and more excellent alignment characteristics can be exhibited. Further, among the above-described orientation-imparting groups, when an organosilicon material having a phenyl group, a substituted phenyl group, a phenylalkyl group, or a substituted phenylalkyl group is used, the affinity with the liquid crystal molecules is also improved. They are arranged in a stable state and have more excellent orientation characteristics.

  As the organosilicon material as described above, it is preferable to use an organopolysilsesquioxane having a cage structure or a partially cleaved cage structure. Thereby, the ratio of affinity and orientation can be arbitrarily changed, and an alignment film having high heat resistance and high visible light transmission characteristics can be obtained.

The weight average molecular weight of such an organosilicon material is preferably 500 to 50000, and more preferably 700 to 50000. Thereby, it can be set as the orientation film | membrane stable optically and physically.
The alignment films 1 and 2 as described above preferably have an average thickness of 0.01 μm to 10 μm, more preferably 0.01 μm to 0.1 μm, and 0.02 μm to 0.05 μm. More preferably. If the average thickness is less than the lower limit, the function as an alignment film may not be sufficiently exhibited depending on the composition of the organosilicon material. On the other hand, if the average thickness exceeds the above upper limit value, the drive voltage becomes high and there is a possibility that the TFT cannot be driven.

[Method of manufacturing liquid crystal device]
Next, a method for manufacturing the liquid crystal device 100 will be described while paying attention to a method for forming an alignment film. FIG. 5 is a process flow showing a method for forming an alignment film.
In addition, the formation process of the alignment film 1 and the alignment film 2 is basically the same process. For this reason, the case where the alignment film 1 is mainly formed will be described here. In the following description, a method for forming an alignment film composed of an organopolysilsesquioxane having a cage structure or a partially cleaved cage structure will be described.

  As shown in FIG. 5, the alignment film forming method of this embodiment includes an alignment film forming liquid preparation step (step S1, step S4, step S7) for preparing an alignment film forming liquid, and the obtained alignment film. A coating film forming step (step S2, step S5, step S8) for applying a film-forming liquid to the substrate to form a coating film, and a curing step (step S3, step S6, step for curing the formed coating film) S9). Steps S1 to S3 are steps for forming the first alignment layer (first inorganic alignment film) 1A, and steps S4 to S6 are for forming the second alignment layer (second inorganic alignment film) 1B. Steps S7 to S9 are steps for forming the third alignment layer (organic alignment film) 1C.

The alignment film forming liquid preparation steps S1, S4, and S7 are polysilsesquioxane material preparation steps in which polysilsesquioxane materials (polysiloxane materials) are prepared by polycondensation of a plurality of types of alkoxysilanes having different compositions. Including. And the liquid for alignment film formation containing the said polysilsesquioxane material obtained here is prepared.
In the alignment film forming liquid preparation step S1 for forming the first alignment layer 1A, the material of the substrate 10 is used so that the first alignment layer 1A finally obtained can have good adhesion to the substrate 10. An alignment film-forming liquid (first inorganic alignment film-forming liquid) containing an inorganic material component having the same or good adhesion is prepared. In the alignment film forming liquid preparation step S4 for forming the second alignment layer 1B, the inorganic material component in the finally obtained second alignment layer 1B is larger than the organic material component (that is, the first alignment layer 1B). An alignment film forming liquid (second inorganic alignment film forming liquid) is prepared so that the composition is close to that of the alignment layer 1A. In the alignment film forming liquid adjustment step S7 for forming the third alignment layer 1C, the alignment film is formed so that the organic material component in the finally obtained third alignment layer 1C is larger than the inorganic material component. Preparation liquid (organic alignment film forming liquid) is prepared.

  The ratio between the inorganic material component and the organic material component in each of the alignment layers 1A to 1C is set to an appropriate value from the viewpoints of the intensity of light incident on the alignment film 1, required alignment characteristics, light resistance, and the like. . When high light resistance is required, the inorganic material components of the first alignment layer 1A and the second alignment layer 1B are increased, and the ratio of the inorganic material components as the entire alignment film 1 is increased. On the other hand, when the intensity of the illumination light is not so high, it is desirable to increase the ratio of the organic material components of the alignment layers 1A to 1C to obtain an alignment film with good alignment characteristics.

Since the first alignment layer 1 </ b> A is a layer that enhances the adhesion with the substrate 10 (adhesion-imparting layer), the composition thereof is preferably as close to the substrate 10 as possible. Usually, since glass is used for the substrate 10, the first alignment layer 1A is preferably composed mainly of an inorganic material such as SiO ₂ . The third alignment layer 1C serves the original function of an alignment film that imparts alignment force to the liquid crystal. For this reason, it is desirable that the third alignment layer 1 </ b> C has a composition containing many organic material components with good alignment characteristics. It is desirable that the second alignment layer 1B located between the first alignment layer 1A and the third alignment layer 1C has an intermediate composition between these layers 1A and 1C. And a layer with high adhesion. In the present embodiment, the second alignment layer 1B is an inorganic alignment film mainly composed of an inorganic material component. However, when sufficient light resistance is obtained by the first alignment layer 1A, the second alignment layer 1B is used as an organic material component. An organic alignment film mainly composed of can also be used.

In the present embodiment, for example, the first alignment layer 1A is a layer composed only of an inorganic material component, and the second alignment layer 1B is an inorganic / organic layer composed of an organic material component of 40% and an inorganic material component of 60%. The third alignment layer 1C is an inorganic / organic composite layer having an organic material component of 80% and an inorganic material component ratio of 20%. Here, the same material component (for example, SiO ₂ ) as that of the substrate 10 is used as the inorganic material component of the alignment layers 1A to 1C in order to increase the adhesion with the substrate 10. Each alignment layer 1A-1C contains this inorganic material component as a common base material.
Hereinafter, each step will be described in detail.

<Liquid preparation step for alignment film formation (S1, S4, S7)>
<Polysilsesquioxane material preparation process>
First, an organic material component having a functional group such as an affinity imparting group and an orientation imparting group in the finally obtained alignment film (alignment film 1 and alignment layers 1A to 1C) and an inorganic material component having no organic group When the film is formed as described below, the alkoxysilane having an affinity-imparting group, the alkoxysilane having an orientation-imparting group, the alkoxysilane having no organic group at a ratio corresponding to the abundance ratio of A plurality of types of alkoxysilanes having a curing reactive group that contributes to the curing reaction are prepared.

  Examples of the alkoxysilane having an affinity-imparting group include vinyltrimethoxysilane, 3-cyanopropyltriethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, allyltriisopropoxysilane, butenyltrimethoxysilane, and butenyl. Triethoxysilane, butenylisopropoxysilane, 2-cyanoethyltrimethoxysilane, 2-cyanoethyltriethoxysilane, 2-cyanoethyltriisopropoxysilane, 3-cyanopropyltriethoxysilane, 3-cyanopropyltriisopropoxysilane, ( Examples include 3-cyanobutyl) methyltrimethoxysilane, (3-cyanobutyl) ethyltrimethoxysilane, and (3-cyanobutyl) methyltriisopropoxysilane.

Examples of the alkoxysilane having an orientation-imparting group include phenyltrimethoxysilane, isobutyltrimethoxysilane, phenyltriethoxysilane, phenyltriisopropoxysilane, isobutyltriethoxysilane, isobutyltriisopropoxysilane, isopropyltrimethoxysilane, Examples thereof include isopropyltriethoxysilane, isopropyltriisopropoxysilane, phenethyltrimethoxysilane, phenethyltriethoxysilane, and phenethyltriisopropoxysilane.
Tetraalkoxysilane is used as the alkoxysilane having no organic group, and examples of the tetraalkoxysilane include tetramethoxysilane, tetraethoxysilane, and tetrabutoxysilane.

The curing reactive group is a functional group having a function of curing the coating film by reacting the curing reactive groups with each other under predetermined conditions. By using an alkoxysilane having such a curing reactive group, the film formability (moldability) of the alignment film forming liquid can be improved. As a result, a physically stable alignment film can be effectively formed.
Examples of such curing reactive groups include glycidoxyalkyl groups, alicyclic epoxyalkyl groups, acryloylalkyl groups, methacryloylalkyl groups, vinyl groups, alkylene groups, alkylidene groups, styryl groups, and styrylalkyl groups. It is done.

Among the above-mentioned, it is particularly preferable to use a glycidoxyalkyl group, an alicyclic epoxyalkyl group, or a methacryloylalkyl group. By having such a functional group, a stable alignment film can be formed more effectively.
Examples of the alkoxysilane having such a curing reaction group include 3-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxysiloxyhexyl) ethyltrimethoxysilane, and 3-methacryloxypropyltrimethoxysilane. Etc.

  Next, a plurality of types of alkoxysilanes as described above, water and alcohols such as methanol, ethanol and isopropyl alcohol as necessary, ethers such as diethyl ether and tetrahydrofuran (THF), acetone, methyl isobutyl ketone, etc. A dilute solvent typified by hydrocarbons such as ketones and toluene is mixed at a predetermined ratio to obtain a mixed solution.

  Next, a hydrolysis and polycondensation catalyst such as an acid catalyst and a base catalyst is added to the obtained mixed solution while stirring. These catalysts may be added in advance to the solvent or water used for the reaction.

  Examples of the acid catalyst (including a solid acid catalyst) include inorganic acids such as sulfuric acid, nitric acid, phosphoric acid, and organic sulfonic acids (for example, benzenesulfonic acid, p-toluenesulfonic acid, naphthalenesulfonic acid, methanesulfonic acid, ethane). Organic acids such as sulfonic acid, etc., and examples of the base catalyst include inorganic bases such as ammonia, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, tertiary amines (trimethylamine, triethylamine, tributylamine) , Triethanolamine, pyridine and the like), organic bases such as tetramethylammonium hydroxide, choline and the like. Of these, sodium hydroxide, potassium hydroxide, and tetraalkylammonium hydroxide, which have a high activity as a base and are easily removed during post-treatment, are preferred.

After adding the hydrolysis catalyst, the alkoxysilane is polycondensed by heating at a predetermined temperature while stirring.
The predetermined temperature (reaction temperature) is preferably 5 ° C to 140 ° C, and more preferably 30 ° C to 60 ° C. If the reaction temperature is too high, the reaction of the curing reactive group may occur. Conversely, if the reaction temperature is too low, the progress of the reaction is remarkably slowed.
The reaction time is preferably 1 to 48 hours, and more preferably 3 to 18 hours. If the reaction time is too long, the reaction of the curing reactive group may occur. Conversely, if the reaction time is too short, the reaction is not completed.

Next, treatments such as neutralization, removal of diluted solvent, and drying are performed as necessary.
By using the method as described above, a polysilsesquioxane material (polysiloxane material) having a cage structure or a partially cleaved cage structure can be obtained.

<Liquid preparation step for alignment film formation>
Next, an alignment film forming liquid containing the polysilsesquioxane material obtained in the above step is prepared.
As the alignment film forming liquid, the polysilsesquioxane material obtained in the above step may be used as it is as the alignment film forming liquid, or a solvent or the like may be added as necessary.
Moreover, you may add a hardening | curing agent (polymerization initiator) to the alignment film formation liquid as needed. Thereby, hardening of a coating film which is mentioned later can be performed easily.

Examples of such a curing agent include benzophenone, 1-hydroxycyclohexyl phenyl ketone, (thiophenoxyphenyl) diphenylsulfonium hexafluorophosphate, bis (diphenylsulfonium) diphenylthioether hexafluorophosphate, and the like. Examples include photopolymerization initiators, thermal polymerization initiators such as azobisisobutyronitrile, azobismethylbutyronitrile, and the like, and one or more of these can be used in combination.
Moreover, you may perform a filtration process with respect to the liquid for alignment film formation as needed. Thereby, impurities contained in the alignment film forming liquid can be removed, and an alignment film having a uniform thickness can be efficiently formed.

<Coating film forming step (S2, S5, S8) and curing step (S3, S6, S9)>
Next, the alignment film forming liquid obtained in the above step is applied onto the substrate 10 to form a coating film composed of the alignment film forming liquid. Then, the formed coating film is cured to form an alignment film.
In the present embodiment, in order to form the three alignment layers 1A to 1C, the coating film forming step and the curing step are each performed three times.

First, the alignment film forming liquid for forming the first alignment layer is applied to the substrate 10 using a coating apparatus.
Examples of the method for applying the alignment film forming liquid include a gravure coating method, a bar coating method, a spray coating method, a spin coating method, a knife coating method, a roll coating method, a die coating method, and an ink jet method. These methods can be selected or used in combination as required.
In this embodiment, since a coating film is formed on the entire surface of the substrate, a spin coating method is used as a coating method, and a spin coater is used as a coating device.

Next, the coating film of the alignment film forming liquid is cured to form a first alignment layer (first inorganic alignment film) 1 </ b> A including only the inorganic material component on the entire surface of the substrate 10.
The coating film can be cured by, for example, heat treatment, energy ray irradiation treatment, or the like. Examples of energy rays include visible light, ultraviolet light, radiation, infrared light, and the like. By performing such a treatment, the curing reactive groups as described above are radically polymerized, cationically polymerized, polycondensed, etc. in the coating film, and the coating film is cured to form an alignment film.

The coating film is particularly preferably cured after removing moisture, solvent, and the like contained in the alignment film forming liquid constituting the coating film (after drying the coating film). Thereby, an alignment film having a stable film thickness can be efficiently formed.
Moreover, you may perform hardening of a coating film, for example, after irradiating an energy beam and pre-hardening a coating film, and carrying out the main hardening by heat processing. That is, the coating film may be cured by temporarily curing the coating film with a relatively low energy once and then completely curing it. Thereby, an alignment film having a stable film thickness can be formed more efficiently.

Next, the alignment film forming liquid for forming the second alignment layer is applied to the substrate 10 using a coating apparatus. The application of the alignment film forming liquid is performed by using a spin coating method in the same manner as the application of the alignment film forming liquid for forming the first alignment layer.
In addition, since the alignment film forming liquid contains a solvent, re-dissolution of the first alignment layer 1A previously formed becomes a problem. In this embodiment, the first alignment layer 1A is subjected to a sol-gel reaction. Therefore, such re-dissolution does not occur. For this reason, the first alignment layer 1A and the second alignment layer 1B can be accurately arranged at desired positions.

  Next, the coating film of the alignment film forming liquid is cured to form a second alignment layer (second inorganic alignment film) 1B mainly composed of inorganic material components on the first alignment layer 1A. The curing conditions of the coating film are the same as those for curing the coating film of the alignment film forming liquid for forming the first alignment layer. Further, using the same procedure, the alignment film forming liquid for forming the third alignment layer is applied to the substrate 10 and cured to mainly contain the organic material component on the second alignment layer 1B. A third alignment layer (organic alignment film) 1C is formed.

  As described above, the TFT array substrate 10 including the alignment film 1 having a multilayer structure including the inorganic alignment film and the organic alignment film is formed. The alignment film 1 (that is, the surface of the third alignment layer 1 </ b> C arranged closest to the liquid crystal 50) can be subjected to an alignment treatment such as rubbing as necessary. Thereby, the alignment characteristic of the alignment film obtained can be made more excellent.

Next, using the same method, the first alignment layer (first inorganic alignment film) 2A, the second alignment layer (second inorganic alignment film) 2B, and the third alignment layer (organic alignment) are formed on the surface of the counter substrate 20. Film) An alignment film 2 made of 2C is formed. The ratio of the inorganic material component to the organic material component in the first alignment layer 2A, the second alignment layer 2B, and the third alignment layer 2C, the composition of the alignment film forming liquid to be prepared, the formation procedure, and the like are as follows. , The same as those in the second alignment layer 1B and the third alignment layer 1C. Then, these substrates 10 and 20 are bonded together via a sealing material 52 provided in a frame shape, and the frame of the sealing material 52 is filled with liquid crystal. Thereafter, a polarizing plate or the like is attached to the outer surface side of the substrates 10 and 20 as necessary.
Thus, the liquid crystal device 100 is completed.

  As described above, the liquid crystal device 100 of this embodiment is configured such that the ratio of the organic material component in the alignment film increases from the substrate side toward the liquid crystal side. For this reason, while increasing the ratio of the inorganic material component of the entire alignment film, only the portion in contact with the liquid crystal 50 can have a composition with a high ratio of the organic material component having a good alignment characteristic. A liquid crystal device having high reliability can be provided. In general, since alignment characteristics and reliability are in a trade-off relationship, both characteristics cannot be realized at the same time with the same alignment film. However, in the present invention, these two characteristics are separated from each other in the alignment film. By realizing with layers, it is possible to satisfy both characteristics simultaneously.

In addition, since the alignment films 1 and 2 are formed by a sol-gel method that is a liquid phase method, the process can be simplified as compared with a conventional method using a vapor phase method such as oblique deposition. it can. In addition, since it can be produced at a low temperature using a chemical reaction, it is possible to combine an organic material and an inorganic material, and an alignment film containing an inorganic material component and an organic material component as in this embodiment. 1 and 2 can be easily formed. On the other hand, a method other than the sol-gel method can be used in that the same liquid phase method is used. For example, as shown in Patent Document 1, it is possible to dissolve the alignment film material in a solvent and recoat it through a nozzle. In this case, however, re-dissolution with the solvent at the boundary portion of the repainted layer. This causes a problem that a precise layer structure cannot be formed. However, if the sol-gel method is used as in the present embodiment, such a problem of re-dissolution does not occur, so that the inorganic alignment film and the organic alignment film can be arranged with high accuracy.
Furthermore, since the alignment films 1 and 2 include an affinity imparting group that improves the affinity with the liquid crystal and an orientation imparting group that controls the alignment of the liquid crystal, the alignment films 1 and 2 are excellent in light resistance and have orientation characteristics. An excellent liquid crystal device can be provided.

  In this embodiment, the alignment films 1 and 2 have a three-layer structure, but the alignment films 1 and 2 may have a two-layer structure or a multilayer structure of four or more layers. Also in this case, the same effect as that of the present embodiment can be obtained by configuring the organic material component ratio in the alignment film to increase from the substrate side toward the liquid crystal side.

[Second Embodiment]
Next, a method for manufacturing a liquid crystal device according to the second embodiment of the present invention will be described.
FIG. 6 is a process flow showing the manufacturing process, and corresponds to FIG. 5 of the first embodiment. The manufacturing method of the liquid crystal device of the present embodiment is basically the same as the manufacturing method of the liquid crystal device of the first embodiment, except that the alignment treatment for the alignment film is performed after the formation of the second alignment layer. This is only performed before the formation of the third alignment layer and not after the formation of the third alignment layer. For this reason, the same code | symbol is attached | subjected about the component which is common in 1st Embodiment, and detailed description is abbreviate | omitted.

  In the present embodiment, first, the first alignment layer (first inorganic alignment film) 1A and the second alignment layer (second inorganic alignment film) 1B are formed on the TFT array substrate 10 from the steps S1 to S6. . The first alignment layer 1A is a layer composed only of an inorganic material component, and the second alignment layer 1B is an inorganic / organic composite layer containing 60% of an inorganic material component and 40% of an organic material component. These steps are the same as those in the first embodiment.

  Next, when the curing step (step S6) of the second alignment layer 1B is completed, an alignment treatment such as rubbing is performed on the surface of the second alignment layer 1B (step S10). Since the organic material component is contained in the second alignment layer 1B, the organic material component is aligned in one direction by such an alignment process, and has an alignment force with respect to the layer disposed thereon. become.

  When the alignment treatment is completed, the liquid for forming an alignment film for forming the third alignment layer is applied onto the second alignment layer 1B by the same method as in the first embodiment, and this is cured to form the third alignment layer ( Organic alignment film) 1C is formed (steps S7 to S9). Since the second alignment layer 1B has alignment ability by the above-described alignment treatment, when an alignment film forming liquid is applied thereon, the organic material component contained in the liquid is changed to the second alignment layer. Under the influence of the orientation treatment of 1B, the film is oriented in one direction and has an orientation ability. For this reason, even if it does not perform rubbing etc. on the surface of the 3rd orientation layer 1C, it becomes a film which has sufficient orientation ability.

Next, using the same method, the first alignment layer (first inorganic alignment film) 2A, the second alignment layer (second inorganic alignment film) 2B, and the third alignment layer (organic alignment) are formed on the surface of the counter substrate 20. Film) An alignment film 2 made of 2C is formed. The ratio of the inorganic material component to the organic material component in the first alignment layer 2A, the second alignment layer 2B, and the third alignment layer 2C, the composition of the alignment film forming liquid to be prepared, the formation procedure, and the like are as follows. , The same as those in the second alignment layer 1B and the third alignment layer 1C. Then, these substrates 10 and 20 are bonded together via a sealing material 52 provided in a frame shape, and liquid crystal is filled in the frame of the sealing material 52. Thereafter, a polarizing plate or the like is attached to the outer surface side of the substrates 10 and 20 as necessary.
Thus, the liquid crystal device is completed.

  In the present embodiment, the alignment-treated layer (second alignment layer) is not in contact with the liquid crystal 50, and therefore the influence of the alignment treatment (such as ravis) does not adversely affect the display characteristics. On the other hand, since the layer in contact with the liquid crystal 50 (third alignment layer) contains a large amount of organic material components, even if the alignment film forming liquid is simply applied, it has alignment ability due to the influence of the alignment processing of the base. A film is formed in the state. For this reason, sufficient orientation ability can be exhibited even if the surface is not subjected to orientation treatment again.

  In this embodiment, the alignment films 1 and 2 have a three-layer structure, but the alignment films 1 and 2 may have a two-layer structure or a multilayer structure of four or more layers. In this case, the effect similar to that of the present embodiment can be obtained by orienting the surface of the layer disposed on the substrate side before forming the layer disposed on the most liquid crystal side.

[Third Embodiment]
The basic structure of the liquid crystal device of this embodiment is the same as that of the liquid crystal device of the first or second embodiment, and the only difference is the material of the alignment layer including the organic material component of the alignment films 1 and 2. . The alignment layer containing the organic material component of the alignment films 1 and 2 in this embodiment uses an alignment film forming liquid containing a hydrolyzate of a silane compound having an organic group and a hydrolyzate of a tetraalkoxysilane. An alignment film is formed. The silane compound having an organic group mainly has a structure in which a silicon atom and an oxygen atom are bonded, and the organic group is directly bonded to a part of the silicon atom with a carbon atom.

  Examples of the organic group include alkyl groups such as a methyl group and an ethyl group, and functional groups having an aromatic ring such as a phenyl group, a benzyl group, a biphenyl group, and a naphthyl group. The use of an organic group having a functional group containing an aromatic ring is preferable because it can improve the regulating force on the liquid crystal molecules and can more reliably align the alignment direction of the liquid crystal molecules. When the organic group has a functional group containing an aromatic ring, it is preferable to use one in which the aromatic ring is bonded to a silicon atom via a carbon atom.

The ratio (number of moles) of organic groups to the number of silicon atoms present in the alignment films 1 and 2 is preferably 5% to 20%, and more preferably 5% to 10%. If the proportion of the organic group is less than the lower limit, depending on the type of the organic group and the like, sufficient affinity with the liquid crystal molecules may not be obtained. On the other hand, when the ratio of the organic group exceeds the upper limit, depending on the type of the organic group, the adhesiveness to the transparent conductive film described later may not be sufficiently obtained.
The alignment films 1 and 2 each have an inorganic alignment film (first alignment layer and second alignment layer) and an organic alignment film (third alignment layer), and these alignment films are arranged from the substrate side to the liquid crystal side. It is the same as the previous embodiment in that the layers are sequentially laminated. The ratio of the organic group contained in each alignment film 1 and 2 is adjusted to a different ratio between the inorganic alignment film and the organic alignment film.

  The alignment films 1 and 2 as described above preferably have an average thickness of 0.01 μm to 10 μm, more preferably 0.01 μm to 0.1 μm, and 0.01 μm to 0.05 μm. Is more preferable. If the average thickness is less than the lower limit, the function as the alignment film may not be sufficiently exhibited depending on the type and ratio of the organic group. On the other hand, when the average thickness exceeds the upper limit value, the drive voltage increases and the power consumption may increase.

[Method of manufacturing liquid crystal device]
Next, a method for manufacturing the liquid crystal device of the present embodiment will be described while paying attention to a method for forming an alignment layer containing organic material components of the alignment films 1 and 2.
In the alignment film forming method of the present embodiment, the alignment film is formed using an alignment film forming liquid containing a hydrolyzate of a silane compound having an organic group as described above and a hydrolyzate of tetraalkoxysilane. .

  In the present embodiment, description will be made assuming that a liquid for forming an alignment film is prepared by separately preparing and mixing a hydrolyzate of a silane compound and a hydrolyzate of a tetraalkoxysilane. By preparing each hydrolyzate separately, the degree of hydrolysis can be adjusted to a more appropriate level. Moreover, the ratio of the organic material component can be freely adjusted by changing the mixing ratio of the hydrolyzate of the silane compound and the hydrolyzate of tetraalkoxysilane. In this embodiment, the alignment films 1 and 2 include an inorganic alignment film and an organic alignment film, and the ratio of the organic material components included in the inorganic alignment film and the organic alignment film is adjusted by the mixing ratio. .

<Preparation of hydrolyzate of silane compound>
First, the preparation method of the hydrolyzate of the silane compound used by this embodiment is demonstrated.
First, a silane compound to be subjected to hydrolysis is prepared.
As such a silane compound, a compound in which a carbon atom constituting an organic group is directly bonded to silicon is used. Thereby, it is possible to prevent the organic group from being detached during hydrolysis or the like, and to reliably leave the organic group in the alignment film.
In addition to the organic group described above, the silane compound may have any substituent as long as it is a hydrolyzable substituent. For example, the silane compound may have an alkoxyl group, a halogen group, or the like.

Among the above-mentioned, it is preferable to use a silane compound having an alkoxyl group and / or a halogen group as a substituent other than an organic group. Thereby, hydrolysis of a silane compound can be performed easily.
Examples of the alkoxyl group include a methoxy group (OMe), an ethoxy group (OEt), a propoxy group (OPr), and a butoxy group (OBu).
Examples of the halogen group include a fluorine group (F), a chlorine group (Cl), and a bromine group (Br).

Such a silane compound has a general formula R _m SiX _(4-m) (3 ≧ m ≧ 1, R is a methyl group (Me), an ethyl group (Et), a phenyl group (Ph), a benzyl group (Bz), etc. And X represents an alkoxyl group, a halogen group, or the like.
Examples of such silane compounds include benzyltriethoxysilane (BzSi (OEt) ₃ ), benzyltriemethoxysilane (BzSi (OMe) ₃ ), benzylmethyldiethoxysilane (BzMeSi (OEt) ₂ ), benzyldimethylethoxy. Silane (BzMe ₂ SiOEt), phenyltriethoxysilane (PhSi (OEt) ₃ ), phenyltrimethoxysilane (PhSi (OMe) ₃ ), phenylmethyldiethoxysilane (PhMeSi (OEt) ₂ ), phenyltrichlorosilane (PhSiCl ₃₎ ), phenylmethyl dichlorosilane (PhMeSiCl _2), phenylethyl trichlorosilane _{(PhCH 2 CH 2 SiCl 3)} , 4- phenylbutyl trichlorosilane _{(Ph (CH 2) 4 SiCl} 3 , 4-phenylbutyl methyldichlorosilane _{(Ph (CH 2) 4 MeSiCl} 2), 4- phenyl-butyldimethylchlorosilane _{(Ph (CH 2) 4 Me} 2 SiCl) , and the like. The silane compound is selected depending on the combination with the liquid crystal composition used.

  Next, the silane compound as described above and the dilution solvent are mixed at a predetermined ratio to obtain a mixed solution. The diluting solvent is not particularly limited as long as the silane compound and its hydrolyzate are soluble. For example, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, t-butanol, 2 Alcohols such as methoxyethanol, 2-ethoxyethanol and 1-methoxy-2-propanol, ketones such as acetone and methyl ethyl ketone, esters such as methyl acetate, ethyl acetate and isopropyl acetate, tetrahydroxyfuran (THF), dioxane And the like, hydrocarbons such as hexane and cyclohexane, and aromatics such as benzene, toluene and xylene.

Next, water is added to the obtained mixed liquid while stirring. At this time, a hydrolysis catalyst such as an acid catalyst or a base catalyst may be added simultaneously.
Examples of acid catalysts (including solid acid catalysts) include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid, and organic sulfonic acids (eg, benzenesulfonic acid, p-toluenesulfonic acid, naphthalenesulfonic acid, methanesulfonic acid). And organic acids such as ethanesulfonic acid, etc., and examples of the base catalyst include inorganic bases such as ammonia, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, tertiary amines (trimethylamine, triethylamine, And organic bases such as tributylamine, triethanolamine, pyridine).
Then, the hydrolyzate of a silane compound is obtained by stirring about 1 minute-2 days at the temperature of about 0 degreeC-80 degreeC.

<Preparation of hydrolyzate of tetraalkoxysilane>
Next, a method for preparing a hydrolyzate of tetraalkoxysilane will be described.
First, tetraalkoxysilane to be subjected to hydrolysis is prepared.
Examples of the tetraalkoxysilane include tetramethoxysilane, tetraethoxysilane, and tetrabutoxysilane.

Next, tetraalkoxysilane as described above and a diluting solvent are mixed at a predetermined ratio to obtain a mixed solution. The diluting solvent is not particularly limited as long as the silane compound and its hydrolyzate are soluble. For example, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, t-butanol, 2 Alcohols such as methoxyethanol, 2-ethoxyethanol and 1-methoxy-2-propanol, ketones such as acetone and methyl ethyl ketone, esters such as methyl acetate, ethyl acetate and isopropyl acetate, tetrahydroxyfuran (THF), dioxane And the like, hydrocarbons such as hexane and cyclohexane, and aromatics such as benzene, toluene and xylene.
Next, the obtained mixed liquid is hydrolyzed in the same manner as the above silane compound to obtain a hydrolyzate of tetraalkoxysilane.

<Preparation of alignment film forming liquid>
Next, the hydrolyzate of the silane compound obtained as described above and the hydrolyzate of tetraalkoxysilane so that the ratio of the organic group in the finally obtained alignment film becomes a desired one. The liquid for forming an alignment film is obtained by mixing at a predetermined ratio and stirring at a predetermined temperature for a predetermined time.

The mixing temperature is preferably about 0 ° C. to 80 ° C., more preferably about 10 ° C. to 50 ° C.
Further, the mixing time is preferably about 1 minute to 2 days, and more preferably about 1 minute to 5 hours.
In addition, you may add water and an additional solvent as needed.
The molar ratio of the hydrolyzate of the silane compound to the hydrolyzate of tetraalkoxysilane in the alignment film forming liquid is preferably 5:95 to 95: 5. Thereby, an optically more stable alignment film can be formed while making the alignment characteristics of the obtained alignment film desired.

<Curing process>
Next, the alignment film forming liquid obtained in the above step is applied onto the substrates 10 and 20 to form a coating film composed of the alignment film forming liquid.
Examples of the method for applying the alignment film forming liquid include a gravure coating method, a bar coating method, a spray coating method, a spin coating method, a knife coating method, a roll coating method, and a die coating method.

Next, the formed coating film is subjected to heat treatment to cure the coating film and form an alignment film.
It is preferable that the heating temperature in a heating process is 50 to 300 degreeC. When the heating temperature is less than the lower limit, it may be difficult to sufficiently cure the coating film depending on the composition of the alignment film-forming liquid. On the other hand, when the heating temperature exceeds the upper limit, the organic group may be altered depending on the composition of the alignment film forming liquid.

  The coating film is preferably cured after removing moisture, solvent, etc. contained in the alignment film forming liquid constituting the coating film (after drying the coating film). Thereby, an alignment film having a stable film thickness can be efficiently formed.

In this embodiment, in order to form a plurality of alignment films including an inorganic alignment film and an organic alignment film on the same substrate, the preparation process of the alignment film forming liquid, the coating film forming process, and the curing process are performed as layers. Depending on the number, each is performed several times.
In addition, you may give a rubbing process after hardening a coating film. Thereby, the alignment characteristic of the alignment film obtained can be made more excellent.
As described above, the alignment films 1 and 2 are formed on the substrates 10 and 20.

As described above, also in the present embodiment, since the ratio of the organic material component in the alignment film increases from the substrate side toward the liquid crystal side, the liquid crystal having good alignment characteristics and high reliability. An apparatus can be provided.
In this embodiment, since the alignment film forming liquid is prepared by mixing the hydrolyzate of the silane compound and the hydrolyzate of tetraalkoxysilane, the organic material can be easily changed by changing the mixing ratio. The ratio of the components can be adjusted.

[Projection type display device]
Next, a projection type display device which is a specific example of the electronic apparatus of the invention will be described with reference to FIG. FIG. 7 is a schematic configuration diagram showing a main part of the projection display device. This projection type display device includes the liquid crystal device according to each of the above-described embodiments as light modulation means.

  7, 810 is a light source, 813 and 814 are dichroic mirrors, 815, 816 and 817 are reflection mirrors, 818 is an incident lens, 819 is a relay lens, 820 is an exit lens, and 822, 823 and 824 are liquid crystal devices of the present invention. 825 is a cross dichroic prism, and 826 is a projection lens. The light source 810 includes a lamp 811 such as a metal halide and a reflector 812 that reflects the light of the lamp.

  The dichroic mirror 813 transmits red light contained in white light from the light source 810 and reflects blue light and green light. The transmitted red light is reflected by the reflection mirror 817 and is incident on the light modulation means 822 for red light. The green light reflected by the dichroic mirror 813 is reflected by the dichroic mirror 814 and is incident on the light modulating means 823 for green light. Further, the blue light reflected by the dichroic mirror 813 passes through the dichroic mirror 814. For blue light, in order to prevent light loss due to a long optical path, a light guide means 821 comprising a relay lens system including an incident lens 818, a relay lens 819, and an exit lens 820 is provided. Blue light is incident on the light modulating means 824 for blue light through the light guiding means 821. Note that the liquid crystal devices of the above-described embodiments are employed for the respective light modulation means 822, 823, and 824.

  The three color lights modulated by the respective light modulation means are incident on the cross dichroic prism 825. The cross dichroic prism 825 is formed by bonding four right-angle prisms. A dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are formed in an X shape at the interface. Yes. These dielectric multilayer films combine the three color lights to form light representing a color image. The synthesized light is projected onto the screen 827 by the projection lens 826 which is a projection optical system, and the image is enlarged and displayed.

  Since the projection type display device employs the liquid crystal device of each of the above-described embodiments, even when high-intensity light irradiation is performed, the photodegradation of the alignment film does not progress as much as in the past. Therefore, stable display can be performed over a long period of time.

The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but it goes without saying that the present invention is not limited to such examples. Various shapes, combinations, and the like of the constituent members shown in the above-described examples are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.
The liquid crystal device of the present invention is not limited to the light modulation means of the projection display device, but is an electronic book, a personal computer, a digital still camera, a liquid crystal television, a viewfinder type or a monitor direct view type video tape recorder, a car navigation device, Electronic devices that can be suitably used as image display means for devices such as pagers, electronic notebooks, calculators, word processors, workstations, videophones, POS terminals, touch panels, etc., all of which are highly reliable and excellent in display quality Can be provided.

It is a top view which shows the liquid crystal device of 1st Embodiment. It is sectional drawing which follows the H-H 'line | wire of FIG. 3 is an equivalent circuit diagram of various elements, wirings, and the like in a plurality of pixels formed in a matrix in the image display region of the liquid crystal device. FIG. FIG. 2 is a schematic diagram showing a cross-sectional structure of the liquid crystal device. 4 is a process flow illustrating a method for manufacturing a liquid crystal device. It is a process flow which shows the manufacturing method of the liquid crystal device of 2nd Embodiment. It is a figure which shows the projection type display apparatus which is an example of an electronic device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,2 ... Alignment film, 1A, 2A ... 1st alignment layer (1st inorganic alignment film), 1B, 2B ... 2nd alignment layer (2nd inorganic alignment film), 1C, 2C ... 3rd alignment layer (organic alignment) 10) TFT array substrate, 20 ... Counter substrate, 50 ... Liquid crystal

Claims (15)

A liquid crystal device having a liquid crystal sandwiched between a pair of substrates,
Of the pair of substrates, at least one substrate has an alignment film on the liquid crystal side surface,
The alignment film is composed of a plurality of layers having a common inorganic material component,
The plurality of layers are configured such that a ratio of an organic material component in the common inorganic material component is increased from the substrate side layer toward the liquid crystal side layer. Liquid crystal device.   Of the plurality of layers, the layer disposed closest to the substrate is composed of an inorganic alignment film mainly composed of an inorganic material component, and the layer disposed closest to the liquid crystal is mainly composed of an organic material component. The liquid crystal device according to claim 1, comprising an organic alignment film.   The liquid crystal device according to claim 2, wherein the inorganic alignment film is mainly composed of the same inorganic material component as the material component of the substrate. The organic material component of the alignment film is composed of an organometallic material,
The organometallic material has, in its molecule, at least one of an affinity imparting group that improves affinity with the liquid crystal and an orientation imparting group that controls the orientation of the liquid crystal. Item 4. The liquid crystal device according to Item 2 or 3.   The liquid crystal device according to claim 4, wherein the affinity imparting group is at least one of a vinyl group, an alkylene group, and a cyanoalkyl group.   The orientation-imparting group is at least one of a phenyl group, a substituted phenyl group, a phenylalkyl group, a substituted phenylalkyl group, and a branched alkyl group having 3 to 12 carbon atoms. Or 5. The liquid crystal device according to 5.   The liquid crystal device according to claim 1, wherein the alignment film is formed by a sol-gel method. A method of manufacturing a liquid crystal device in which a liquid crystal is sandwiched between a pair of substrates,
A step of forming an alignment film on the liquid crystal side surface of at least one of the pair of substrates;
In the alignment film forming step, a plurality of layers having a common base material, the ratio of the organic material component in the base material increases from the substrate side layer toward the liquid crystal side layer, A method for manufacturing a liquid crystal device, comprising: sequentially forming steps.   Of the plurality of layers, the layer disposed closest to the substrate is formed of an inorganic alignment film mainly composed of an inorganic material component, and the layer disposed closest to the liquid crystal is mainly composed of an organic material component. 9. The method of manufacturing a liquid crystal device according to claim 8, wherein the liquid crystal device is formed of an organic alignment film.   The method for manufacturing a liquid crystal device according to claim 9, wherein the inorganic alignment film is mainly composed of the same inorganic material component as a main component of the substrate.   In the step of forming the alignment film, the metal alkoxide is subjected to polycondensation, and in the molecule, at least one of an affinity imparting group that improves the affinity with the liquid crystal and an orientation imparting group that controls the alignment of the liquid crystal. 11. The method according to claim 8, comprising: a step of preparing an alignment film-forming liquid having a composition; and a step of curing the alignment film-forming liquid to form the alignment film. A method for manufacturing the liquid crystal device according to claim.   The step of forming the alignment film includes a step of performing an alignment treatment on the surface of the layer arranged on the substrate side before forming the layer arranged on the liquid crystal side most of the plurality of layers. The method of manufacturing a liquid crystal device according to claim 11.   The alignment film-forming liquid contains a hydrolyzate of a silane compound having an organic group and a hydrolyzate of a tetraalkoxysilane, and as the silane compound, carbon atoms constituting the organic group are directly bonded to silicon atoms. 13. The method of manufacturing a liquid crystal device according to claim 11 or 12, wherein the liquid crystal device is used.   The method of manufacturing a liquid crystal device according to claim 13, wherein the organic group is a functional group including an aromatic ring. A projection display comprising the liquid crystal device according to any one of claims 1 to 7 or the liquid crystal device manufactured by the manufacturing method according to any one of claims 8 to 14. apparatus.

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