JP2006047613A - Liquid crystal display element, and method for manufacturing the same, and projection display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface treating agent which is suited for a liquid crystal display element equipped with a vertical orientation film composed of an oblique vapor deposition film of an inorganic oxide, and with which the temporal stability, alleviation of an image persistence phenomenon and lightfastness of the orientation are improved through surface treatment of the orientation film, and a method for the treatment. <P>SOLUTION: The method is applied to the liquid crystal display element utilizing the vertical orientation film composed of the oblique vapor deposition film of the inorganic oxide, and is characterized by having surface hydroxy groups of the oblique vapor deposition film having been subjected to chemical reaction treatment with a metal alcoholate. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

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

In recent years, vertical alignment type liquid crystal display elements have been put to practical use in liquid crystal televisions (direct-view display devices), liquid crystal projectors (projection display devices), and the like. As a vertical alignment film used for these vertical alignment type liquid crystal display elements, for example, an organic alignment film such as polyimide is used for a liquid crystal television, and an inorganic alignment film such as SiO ₂ is frequently used for a liquid crystal projector.

The inorganic alignment film used in a vertical _{orientation, SiO X (x <2)} , SiO 2, TiO 2, MgO, Al 2 O 3, In 2 O 3, Sb 2 O 3, Ta 2 O 5 inorganic oxide such as Obliquely deposited films of objects are known. For example, in the case of SiO _2, by using a thin film of SiO ₂ was obliquely evaporated at an appropriate angle of 30 ° or more with respect to the substrate surface, the dielectric anisotropy is negative liquid crystal material having a predetermined pretilt Can be aligned vertically. Such an inorganic alignment film has a very slow light degradation rate due to short-wavelength visible light and ultraviolet light, and is excellent in light resistance, compared to an organic alignment film such as polyimide.

  Further, it is known that a vertical alignment film made of an inorganic oxide is inferior in alignment stability to a vertical alignment film made of an organic material. In inorganic oxides, vertical alignment is considered to be due to topological effects such as the shape and inclination of the inorganic oxide column formed by oblique vapor deposition and the effect of the anisotropy of the dispersive force in the molecular axis direction and perpendicular direction of the liquid crystal molecules. However, the vertical anchoring force is weak and the alignment stability is poor. On the other hand, the surface of an organic material used for vertical alignment is generally covered with long-chain alkyl. In addition, short chain alkyl groups are substituted at both ends of the liquid crystal molecules used for vertical alignment. In organic materials, vertical alignment is considered to be due to the effect of the affinity between the alignment layer and the alkyl group of the liquid crystal molecules and the effect of the anisotropy of the dispersion force in the molecular axis direction and the vertical direction of the liquid crystal molecules. Is large and the alignment stability is large. It is known that the vertical anchoring force of organic materials is one or more orders of magnitude greater than that of inorganic oxides.

  In addition, since the structure of the obliquely deposited inorganic oxide film is porous and the surface thereof has a large number of polarized hydroxyl groups and has a large polarity, impurities contained in the liquid crystal display element, particularly polar groups, are present. Easy to adsorb compounds. Here, the impurities include impurities and unreacted components in the sealant, impurities and moisture in the liquid crystal material, dirt attached in the manufacturing process, and the like. It is known that when impurities are adsorbed on the surface of the obliquely deposited film, the shape and polarity of the surface are changed, the vertical anchoring force is lowered, and an alignment abnormality is caused. In particular, when sealing a liquid crystal display element, it has been found that an abnormal alignment region occurs due to diffusion and adsorption of impurities in the sealant and unreacted components, and the abnormal alignment region expands with time.

Furthermore, the hydroxyl group on the surface of the vertical alignment film made of an inorganic oxide, particularly SiO _2, is strongly acidic, the isoelectric point is small at pH 2.0, and the water contained in the element at pH 7 inside a normal liquid crystal display element. Since most of the hydroxyl groups covered with ion are negatively ionized, the adsorption amount and adsorption force of ionic impurities are large, and when the liquid crystal display element is driven, the ions in the liquid crystal with respect to the two alignment film surfaces As a result of the irreversible adsorption of conductive impurities, a hysteresis phenomenon may occur when the V of the C (electric capacity) -V (applied voltage) characteristic of the liquid crystal display element is raised or lowered, and a burn-in phenomenon may occur in the liquid crystal display. I understand.

  Therefore, the vertical anchoring force of the inorganic oxide alignment film is strengthened to improve alignment stability, and the ionization rate of hydroxyl groups on the surface of the inorganic oxide alignment film is lowered to reduce the adsorption amount of ionic impurities, resulting in a seizure phenomenon. As a method of relaxing the surface, surface modification of inorganic oxides with various surface modifiers has been devised.

As a surface modification method for SiO ₂ or the like, surface treatment of the hydroxyl group on the alignment film surface with a higher alcohol and a silane coupling agent is considered. Examples of such surface modification methods include those described in Patent Documents 1, 2, and 3.
JP-A-11-160711 JP 2000-47211 A JP-A-5-203958

In the above-mentioned Patent Document 1, a treatment in which an obliquely deposited SiO ₂ film is exposed to a higher alcohol vapor is used. However, since the treatment temperature is low, the higher alcohol is only physically adsorbed, and the SiO ₂ surface and the higher alcohol are not adsorbed. The bond strength was weak, and it was detached by bringing it into contact with a liquid crystal material, so that a stable vertical alignment force could not be obtained initially.

Further, in the above-mentioned Patent Document 2, since a treatment of baking an obliquely deposited SiO ₂ film wetted with a higher alcohol is used, a chemical having a strong alcohol and a strong OH group on the surface of the obliquely deposited film of SiO ₂ is used. It seems that the bond is made, the surface polarity decreases and the amount of adsorbed impurities decreases. However, it has been found that since the vertical alignment force of the long-chain alkyl group bonded to the surface is not sufficient, an abnormal alignment region occurs during sealing, and the abnormal alignment region expands with time. In addition, when a liquid crystal display element using an obliquely deposited SiO ₂ film chemically treated with a higher alcohol was driven, the liquid crystal display element using an obliquely deposited SiO ₂ film was relaxed, but seizure occurred. A phenomenon occurred.

In Patent Document 3, octadecyldimethyl (3- (trimethoxysilyl) propyl) ammonium, a silane coupling agent used as a vertical alignment agent for an obliquely deposited SiO ₂ film deposited while assisting with an ion beam. After applying chloride (C ₁₈ H ₃₇ N ⁺ (CH ₃ ) ₂ (CH ₂ ) ₃ Si (OCH ₃ ) ₃ Cl ⁻ ), baking is performed at 110 ° C. for 1 hour. However, as in the above-mentioned Patent Document 2, it was found that an abnormal alignment region occurs at the time of sealing because the vertical alignment force of the long-chain alkyl group bonded to the surface is not sufficient, and the abnormal alignment region expands with time. . In addition, when a liquid crystal display element using an obliquely deposited SiO ₂ film chemically treated with the above silane coupling agent was driven, an image sticking phenomenon was observed compared to a liquid crystal display element using an untreated treated obliquely deposited SiO ₂ film. It became terrible. This is considered to be because the amount of ionic impurities adsorbed on the alignment film surface increased because the silane coupling was ionized with salt.

The present invention has been made to solve the above problems, and in a vertical alignment type liquid crystal display element using an oblique deposition film of an inorganic oxide as an alignment film, the oblique deposition film is chemically formed. To provide a surface treatment agent with high light resistance that can improve the alignment stability at the time of sealing and to reduce the image sticking phenomenon by surface modification, and is comparable to inorganic oxides, and a method for producing the same. It is an object.
The present invention also provides a high-quality and highly durable liquid crystal display element having such a surface-modified inorganic oxide obliquely deposited alignment film, and a reliable projection provided with the liquid crystal display element. It aims at providing a type | mold display apparatus.

In order to solve the above-mentioned problems, the liquid crystal display element of the present invention is a liquid crystal display element using a vertical alignment film composed of an obliquely deposited inorganic oxide film, wherein the surface hydroxyl group of the obliquely deposited film is a metal alcoholate. It is characterized by chemical reaction treatment.
By using an obliquely deposited inorganic oxide film treated with such a compound, the initial value of the vertical anchoring force is increased and the adsorption of polar organic impurities is reduced, which occurs when sealing a liquid crystal display element. It is possible to reduce the temporal expansion speed of the orientation abnormal region. Further, by suppressing the ionization of the hydroxyl group on the surface of the alignment film, it is possible to weaken the adsorption force of the ionic impurities in the liquid crystal and alleviate the image sticking phenomenon.

  In order to solve the above problems, the liquid crystal display element of the present invention is a liquid crystal display element using a vertical alignment film made of an obliquely deposited inorganic oxide film, wherein the surface hydroxyl groups of the obliquely deposited film are ( It is characterized by chemical reaction treatment with a metal alcoholate represented by Chemical Formula 2).

However, in (Chemical Formula 2), R ₁ is a linear or branched alkyl group having 6 to 30 carbon atoms, a linear or branched fluorinated alkyl group having 6 to 30 carbon atoms, or a steroid or a derivative thereof. Is a single bond, —O—, —OCO—, —COO—, —CO—, —CH (CH ₃ ) ═C—CO—, —PO—, or —OPO (OH) PO (O—) ₂ , M is aluminum, titanium, or zirconium, and R ₂ is a linear or branched alkyl group having 1 to 6 carbon atoms, a linear or branched alkyl alkylene group having 1 to 4 carbon atoms, or —CH ₂ CO—. Where m is an integer from 1 to 3 and n is an integer from 1 to 3.

  By using such an obliquely deposited film of inorganic oxide treated with metal alcoholate, the initial value of the vertical anchoring force is increased and the adsorption of polar organic impurities is further reduced. It is possible to further reduce the seizure phenomenon by further reducing the time-dependent expansion rate of the orientation abnormal region to be generated and suppressing ionization of hydroxyl groups on the obliquely deposited film surface.

  Further, since the metal alcoholate represented by (Chemical Formula 2) has no absorption in the short wavelength visible light region, when the liquid crystal display element of the present invention is used as a liquid crystal light valve of a liquid crystal projector, an untreated inorganic oxide. Compared to the case of using an alignment film, the light resistance is not inferior.

Moreover, in order to solve the above-mentioned problem, the surface hydroxyl group of the oblique deposition film is subjected to a chemical reaction treatment with a metal alcoholate in a selective plane region.
By using an obliquely deposited inorganic oxide film chemically treated with a metal alcoholate in such a selective planar region, for example, the surface of the obliquely deposited film corresponding to the adhesive region of the sealant is treated with a metal alcoholate. By not applying, it is possible to prevent a decrease in the adhesive strength between the sealing agent and the oblique vapor deposition film.

In order to solve the above-mentioned problems, the present invention is a method for producing a liquid crystal display element, wherein the liquid crystal vertical alignment film is composed of an obliquely deposited inorganic oxide film whose surface hydroxyl group is chemically reacted with a metal alcoholate, The obliquely deposited film of the surface-treated inorganic oxide is formed by a heating process in which the obliquely deposited film is heated and chemically reacted in a solution composed of the metal alcoholate and a high-boiling organic solvent. A method for manufacturing a liquid crystal display device is provided.
According to such a manufacturing method, since the hydroxyl group on the surface of the inorganic oxide alignment film chemically bonds with the metal alcoholate, the alignment stability is excellent, the adsorption of polar organic impurities is reduced, and the alignment abnormal region generated at the time of sealing is reduced. A liquid crystal display element having a reduced light-expansion rate and an ionization of a surface hydroxyl group to alleviate the image sticking phenomenon and having excellent light resistance can be obtained.

Furthermore, the projection type display device of the present invention is characterized in that the liquid crystal display element described above is provided as a light modulation device. Specifically, the light modulation device includes a light source device, a light modulation device that modulates light emitted from the light source device, and a projection device that projects light modulated by the light modulation device. It can be composed of a display element.
Since such a projection display device includes the liquid crystal display element of the present invention as a light modulation device, the projection display device is excellent in reliability with less occurrence of problems due to use over time.

[First Embodiment]
Hereinafter, embodiments according to the present invention will be described with reference to the drawings. In addition, in each figure, in order to make each layer and each member into a size that can be recognized on the drawing, the scale is varied for each layer and each member.
The liquid crystal display element of the present embodiment shown below has an oblique vapor deposition film of an inorganic compound chemically surface-treated with the metal alcoholate according to the present invention, and an active device using a TFT (Thin Film Transistor) element as a switching element. It is a matrix type liquid crystal display element. FIG. 1 is an equivalent circuit diagram of switching elements, signal lines, and the like in a plurality of pixels arranged in a matrix constituting the pixel region of the liquid crystal display element of this embodiment.

  FIG. 2 is a plan view showing the structure of a plurality of pixel groups adjacent to each other on a TFT array substrate on which data lines, scanning lines, pixel electrodes and the like are formed.

  FIG. 3 is a cross-sectional view showing the structure of the liquid crystal display element of this embodiment.

In the liquid crystal display element of the present embodiment, as shown in FIG. 1, a plurality of pixels arranged in a matrix includes a pixel electrode 123 and a TFT that is a switching element for controlling energization of the pixel electrode 123. Each element 30 is formed, and a data line 6 a to which a data signal is supplied is electrically connected to the source of the TFT element 30. The data signals S1, S2,..., Sn to be written to the data line 6a are supplied line-sequentially in this order, or are supplied for each group to a plurality of adjacent data lines 6a.
In addition, the scanning line 3a is electrically connected to the gate of the TFT element 30, and scanning signals G1, G2,..., Gm are applied to the plurality of scanning lines 3a in a pulse-sequential manner at predetermined timing. The Further, the pixel electrode 123 is electrically connected to the drain of the TFT element 30, and the data signals S1, S2,... Supplied from the data line 6a are turned on by turning on the TFT element 30 as a switching element for a certain period. , Sn is written at a predetermined timing.
Data signals S1, S2,..., Sn written to the liquid crystal via the pixel electrode 123 are held for a certain period with the common electrode described later. The liquid crystal can modulate light by changing the orientation and order of the molecular assembly according to the applied voltage level. Here, in order to prevent the retained data signal from leaking, a storage capacitor 70 is added in parallel with the liquid crystal capacitor formed between the pixel electrode 123 and the common electrode.

  Next, a planar configuration of the liquid crystal display element of the present embodiment will be described with reference to FIG. As shown in FIG. 2, a rectangular pixel electrode 123 made of a transparent conductive material such as indium tin oxide (hereinafter abbreviated as “ITO”) is outlined on a transparent substrate (to be described later) by a dotted line portion 123A. ) Are provided in a matrix, and data lines 6a, scanning lines 3a, and capacitor lines 3b are provided along the vertical and horizontal boundaries of the pixel electrode 123, respectively. In the present embodiment, each pixel electrode 123 and a region where the data line 6a, the scanning line 3a, the capacitor line 3b, etc., which are arranged so as to surround each pixel electrode 123 are formed are pixels, and are arranged in a matrix. It has a structure capable of performing light modulation for each pixel.

Next, a cross-sectional configuration of the liquid crystal display element of the present embodiment will be described based on FIG. As shown in FIG. 3, the liquid crystal display element 100 of this embodiment has a cross-sectional configuration in which a liquid crystal layer 104 is sandwiched between a pair of substrates, and light from a light source disposed on the lower side in the figure. Can be modulated by the liquid crystal display element 100.
The liquid crystal display element 100 has a configuration in which a liquid crystal layer 104 is sandwiched between an upper substrate 101 and a lower substrate 102 which are arranged to face each other, and the liquid crystal layer 104 is sealed with a seal 105. On the inner surface side (the liquid crystal layer 104 side) of the upper substrate 101, a common electrode 113 and a vertical alignment film 115 disposed in a solid shape are formed on the entire surface of the substrate, and an outer surface side (upper surface in the drawing) of the upper substrate 101 is formed. The retardation plate 118 and the polarizing plate 119 are laminated in this order.
On the other hand, on the inner surface side (liquid crystal layer 104 side) of the lower substrate 102, a plurality of pixel electrodes 123 arranged in a matrix in a plan view and a vertical alignment film 125 are provided. Further, a phase difference plate 128 and a polarizing plate 129 are provided in this order on the outer surface side of the lower substrate 102. For example, a light source (illustrated) further provided on the lower side (outer surface side) of the polarizing plate 129. Light is selectively transmitted through and modulated. The polarizing plates 119 and 129 disposed on the upper and lower substrates 101 and 102 are disposed such that the transmission polarization axes intersect each other vertically.

In the liquid crystal display element 100 of the present embodiment, a liquid crystal composition mainly composed of a nematic liquid crystal compound having a fluorine-based negative dielectric anisotropy is used as a liquid crystal material constituting the liquid crystal layer 104.
In general, a liquid crystal material used for a liquid crystal display element is a nematic liquid crystal compound, and is practically used as a liquid crystal composition in which a plurality of nematic liquid crystal compounds are mixed at a predetermined ratio in order to obtain various characteristics. The general molecular structure of nematic liquid crystal compounds consists of a skeletal group in which multiple rings are linearly bonded, side chain groups in which substituents are introduced in the minor axis direction of these linked rings, and the length of the ring at both ends of the skeleton group. It consists of two terminal groups with substituents introduced in the axial direction.

The molecular structure of the fluorine-based liquid crystal compound with negative dielectric anisotropy used for vertical alignment is a cyclohexane ring, a benzene ring, a heterocyclic ring or the like as the ring, and 2 to 4 of these rings are linearly connected. A skeleton group is formed by linking, and a hydrogen atom, a fluorine atom, or the like is used as a side chain group, and an alkyl group, an alkoxy group, a fluorine atom, or the like is used as a terminal group. By introducing several fluorine atoms with extremely large electron-withdrawing properties into the side chain group and introducing an electron-donating alkyl group or alkoxy into both end groups, the dipole moment in the molecular minor axis direction is reduced in the molecular major axis direction. A nematic liquid crystal compound having a larger dielectric anisotropy than that is obtained.
For example, a liquid crystal compound having a molecular structure represented by (Chemical Formula 3), (Chemical Formula 4), and (Chemical Formula 5) is used. Although (Chemical Formula 3) has a characteristic that the dielectric anisotropy is negative and the absolute value thereof is particularly large, it has a disadvantage that the nematic phase-isotropic phase transition temperature is low due to the bicyclic ring and the short molecular length. (Chemical Formula 4) is a tricyclic compound having a negative dielectric anisotropy and a large absolute value, a high nematic phase-isotropic phase transition temperature, and a liquid crystal composition having a negative dielectric anisotropy. Often used as the main component. (Chemical formula 5) is a tetracyclic compound and has a very high nematic phase-isotropic phase transition temperature, but has a negative dielectric anisotropy but a small absolute value and a high viscosity.

However, in (Chemical Formula 3) to (Chemical Formula 5), Rings A to J are a cyclohexane ring, a benzene ring or a heterocyclic ring, R ₁ to R ₆ are an alkyl group, an alkoxy group or a fluorine atom, and X ₁ to X ₁₀ is a hydrogen atom or a fluorine atom.

  The vertical alignment films 115 and 125 disposed so as to face each other between the substrates 101 and 102 are each formed by depositing an inorganic oxide by a vapor deposition method, and the surfaces thereof are formed with the metal alcoholate according to the present invention. Chemically surface treated. As described above, in this embodiment, since the surfaces of the vertical alignment films 115 and 125 are coated with the metal alcoholate, the alignment stability is higher than that of the non-treatment, alcohol treatment and silane treatment vertical alignment films. In addition, it reduces the image sticking phenomenon and further has a comparable light resistance.

A vapor deposition method for forming the vertical alignment films 115 and 125 on the substrate will be described. FIG. 4 is an explanatory diagram schematically showing the configuration of the vapor deposition apparatus. In this embodiment, the vapor deposition apparatus 300 is used to obliquely deposit inorganic oxide (for example, SiO ₂ ) from a predetermined direction with respect to the substrate. I am going to do it.

The vapor deposition apparatus 300 includes a vapor deposition source 302 that generates SiO ₂ vapor, a vapor circulation portion 303 having an opening 303 a through which SiO ₂ vapor can flow, and a substrate S inclined at a predetermined angle with respect to the vapor deposition source 302. A vapor deposition chamber 308 having a substrate disposing portion 307 to be disposed, and a vacuum pump 310 for evacuating the vapor deposition chamber 308 are provided.

The vapor deposition method in the present embodiment is as follows. First, when the vacuum pump 310 is operated, the vapor deposition chamber 308 is evacuated, and when the vapor deposition source 302 is heated by a heating device (not shown), vapor of SiO ₂ is generated from the vapor deposition source 302. The SiO ₂ vapor generated from the vapor deposition source 302 passes through the opening 303a and is vapor deposited on the surface of the substrate S at a predetermined angle (vapor deposition angle). Here, in this embodiment, in order to provide vertical alignment, the vapor deposition angle is determined so that the angle θ between the vapor deposition source and the substrate S is, for example, 30 °.

Next, the surface treatment of the vertical alignment films 115 and 125 will be described.
As the surface treating agent for the vertical alignment film, a compound that can reduce the critical surface tension of the alignment film surface and can physically adsorb or chemically bond with the hydroxyl group on the alignment film surface is generally used. Examples include long chain alkyltrialkoxysilanes and long chain alcohols.
In addition, there are two surface modification treatment methods using a surface treatment agent for the hydroxyl group on the surface of the inorganic oxide: an adsorption treatment method and a chemical reaction treatment method. Adsorbed surface modifiers bind to surface hydroxyl groups of inorganic oxides with van der Waals bonds or hydrogen bonds, but their bonding strength is weak, and surface modifiers are easy to desorb. I can't get it. On the other hand, the chemically treated surface treatment agent has a strong bonding force because it is covalently bonded to the hydroxyl group on the surface of the inorganic oxide, and the surface treatment agent is difficult to desorb and a stable anchoring force that does not change with time can be obtained.

Many hydroxyl groups bonded to Si atoms exist on the surface of the obliquely deposited SiO ₂ film. These hydroxyl groups chemically react with metal alcoholates to form M (metal) -O-Si bonds and alcohols. The polarity of the hydroxyl group bonded to Si in M-O-Si decreases as the difference in electronegativity between Si and M increases, and the isoelectric point moves in the direction of higher pH, thereby suppressing the dissociation of the hydroxyl group. .

  As the metal alcoholate of the present invention, a compound represented by the following (Chemical Formula 6) can be used.

However, in (Chemical Formula 6), R ₁ is a linear or branched alkyl group having 6 to 30 carbon atoms, a linear or branched fluorinated alkyl group having 6 to 30 carbon atoms, or a steroid or a derivative thereof, Is a single bond, —O—, —OCO—, —COO—, —CO—, —CH (CH ₃ ) ═C—CO—, —PO—, or —OPO (OH) PO (O—) ₂ , M is aluminum, titanium, or zirconium, and R ₂ is a linear or branched alkyl group having 1 to 6 carbon atoms, a linear or branched alkyl alkylene group having 1 to 4 carbon atoms, or —CH ₂ CO—. , M is an integer from 1 to 3, and n is an integer from 1 to 3.

Here, as the alkyl group used for R ₁ , by making it a linear alkyl group having 8 to 24 carbon atoms, it is possible to further enhance the vertical anchoring force, and high alignment stability can be obtained. It is possible to reduce the temporal enlargement speed of the abnormal alignment region that occurs when the display element is sealed. In addition, unlike an unsaturated alkyl group or an aromatic group, such an alkyl group does not absorb light in a short wavelength visible light region, so that light degradation due to irradiation with short wavelength visible light hardly occurs.

The fluorinated alkyl group used for R ₁ includes a straight-chain saturated alkyl group in which part or all of the hydrogen atoms are substituted with fluorine atoms, a straight chain in which some or all of the hydrogen atoms are substituted with fluorine atoms, or A branched saturated alkyl group or a linear or branched saturated alicyclic alkyl group in which some or all of the hydrogen atoms are substituted with fluorine atoms can be used.

In general, between the critical surface tension of the alignment film surface and the surface tension of the liquid crystal and the alignment direction of the liquid crystal molecules, if the surface tension of the liquid crystal is larger than the critical surface tension of the alignment film surface, the liquid crystal is vertically aligned. If is smaller than the critical surface tension of the alignment film surface, horizontal alignment is performed. Further, the rule of thumb holds that the larger the difference between the critical surface tension of the alignment film surface and the surface tension of the liquid crystal, the greater the anchoring force of the liquid crystal. When a hydrogen atom of an alkyl group is substituted with a fluorine atom, the critical surface tension of the alkyl group decreases and the vertical anchoring force increases as the number of substituted fluorine atoms increases. Further, when the carbon number of the alkyl group is increased, the density of the alkyl group occupying the oxide surface is increased, the critical surface tension is decreased, and the vertical anchoring force is increased. Therefore, the greater the number of substitution of fluorine atoms in the alkyl group and the greater the number of carbons, the better. However, from the test results, the substitution ratio of fluorine atoms in the total hydrogen atoms of the alkyl group is 50% or more. A stable orientation was obtained when the carbon number was 6 or more. By using an obliquely deposited inorganic oxide film treated with such a surface treatment agent, the initial value of the vertical anchoring force can be further increased, and further, the adsorption of impurities can be reduced to seal the liquid crystal display element. In addition, the time-dependent expansion rate of the abnormal alignment region occurring in the region can be further reduced.
Since such a fluorinated alkyl group does not absorb in the visible light region with a short wavelength unlike an unsaturated alkyl group or aromatic group, photodegradation due to irradiation with visible light with a short wavelength hardly occurs.

Further, as the steroid used for R ₁ or a derivative thereof, a compound having a hydroxy group is preferable.
As the structure of hydroxysteroid, a compound having a branched alkyl group such as 1,5-dimethylhexyl group substituted at the 17-position, 1, 3,5-trimethylhexyl group, etc., and a hydroxyl group substituted at the 2,3- or 4-position Is mentioned. When the hydroxy steroid compound and the hydroxyl group on the surface of the inorganic oxide are esterified, the hydroxyl group is chemically bonded to the surface hydroxyl group, and the chemically bonded steroid compound is arranged with the branched alkyl group facing the surface of the inorganic oxide.

  When a liquid crystal molecule having a negative fluorine dielectric anisotropy is brought into contact with the surface of an inorganic oxide chemically treated with a hydroxysteroid compound, the condensed ring in the steroid compound is larger than the liquid crystal molecule. Sinks into the gaps of the teroid compound, and the first layer of liquid crystal molecules is arranged substantially perpendicular to the surface of the inorganic oxide with the alkyl group directed in the liquid crystal bulk direction. The next layer of liquid crystal molecules is controlled by the first layer and vertically aligned to obtain a strong vertical anchoring force.

  In addition, since a compound in which a hydroxyl group is bonded to the 3-position in a steroid is most likely to have a linear structure, when a chemical bond is formed with a hydroxyl group on the surface of an inorganic oxide, the steroid compound has a branched alkyl group on the surface. The vertical anchoring force is the strongest with a vertical arrangement. By using an obliquely deposited inorganic oxide film treated with such a surface treatment agent, the initial value of the vertical anchoring force can be further increased, and further, the adsorption of impurities can be reduced to seal the liquid crystal display element. In addition, the time-dependent expansion rate of the abnormal alignment region that occurs can be further reduced.

  Examples of steroids having a hydroxyl group at the 3-position include cholesterol (Chemical Formula 7), epicholesterol, cholestanol (Chemical Formula 8), epicholestanol (Chemical Formula 9), ergostanol, epiergostanol, copresterol, and epicopresterol. , Α-ergosterol, β-sitosterol, stigmasteranol, campesterol (Chemical Formula 10) and the like.

  Furthermore, since the all-carbon bond is composed of a single bond and the surface-treated inorganic oxide obliquely deposited film with a steroid compound having a hydroxyl group at the 3-position has no absorption in the vicinity of the visible light region. When a liquid crystal light valve using an inorganic oxide alignment film surface-treated with a simple compound is mounted, a liquid crystal projector with high light resistance can be obtained.

  Inorganic oxides are very stable to visible and ultraviolet light, but organic compounds are generally known to react chemically when irradiated with visible and ultraviolet light. Therefore, in the inorganic oxide alignment film surface-treated with an organic compound, there is a concern about a decrease in light resistance, but in the case of a 3-hydroxyl steroid compound in which all carbon-carbon bonds are composed of single bonds, a carbon-carbon single bond The visible-ultraviolet light absorption spectrum of the compound is stable to visible light because it has no absorption above 300 nm, and the light resistance of the inorganic oxide alignment film surface-treated with such a compound is untreated inorganic oxidation. It is not inferior to that of things.

  Examples of the steroid having a hydroxyl group at the 3-position include cholestanol (Chemical Formula 8), epicholestanol (Chemical Formula 9), ergostanol, epiergostanol, copresterol, epicopresterol, stigmasteranol and the like.

As M (metal atom), aluminum, titanium, or zirconium having a lower electronegativity than silicon and forming a chemically stable alcoholate is used. When the hydroxyl group on the SiO ₂ surface is chemically treated with these metal alcoholates, the metal alcoholate is hydrolyzed by water in the reaction solvent to generate hydroxyl groups. The hydroxyl group present on the surface of the metal oxide is more acidic and more ionized as the electronegativity of the metal atom bonded to the hydroxyl group increases, and the ionic impurities in the liquid crystal are adsorbed, and the image sticking phenomenon is likely to occur. The value of electronegativity of each metal atom is 1.90 for silicon, 1.61 for aluminum, 1.54 for titanium, 1.33 for zirconium, and silicon with the largest electronegativity shows the most seizure phenomenon. It turns out that it is easy to wake up.

The isoelectric points indicating the pH at which the surface current of the metal oxide is zero are 2.0 for silicon, 9.3 for aluminum, 6.3 for titanium, and 6.6 for zirconium. As shown in (Chemical Formula 11), OH on the surface of the metal oxide is ionized positively by adding a hydrogen ion to a hydroxyl group to form M-OH ₂ ^{+ at} a pH higher than the isoelectric point. At a pH of 1, the hydroxyl group dissociates and becomes M-O ⁻ and is negatively ionized. At a pH equal to the isoelectric point, the amount of positive ions and the amount of negative ions are equal, and the net electricity is zero.

Moreover, the ionization rate of the hydroxyl group on the surface of the metal oxide increases as the pH increases from the isoelectric point. On the other hand, since the pH of the liquid crystal in the liquid crystal display element is about 7, silicon, titanium and zirconium are ionized negatively, and aluminum is ionized positively. Since the ionization progresses as the pH is further away from the isoelectric point, the metal atom of the present invention whose isoelectric point is close to pH 7 in the liquid crystal display element has a lower ionization rate than silicon, and therefore the amount of ionic impurities adsorbed is small. . At the same time, a metal having a low electronegativity has an effect of reducing the polarity of silicon, so that the amount of polar organic impurities adsorbed also decreases. It is known that the metal atom of the present invention forms a chemically stable alcoholate with the hydroxyl group on the surface of SiO ₂ like Si.

  In addition, by using the oblique deposition film of the inorganic oxide chemically treated with the metal alcoholate according to the present invention in the selective planar region, for example, the oblique contact corresponding to the adhesion region of the sealant and / or the sealant is performed. When the side surface of the vapor-deposited film is treated with a metal alcoholate, the critical surface tension of the obliquely vapor-deposited film surface decreases, resulting in poor wettability with the adhesive, hydrogen bonding or chemical bonding with the sealant component. When the surface hydroxyl group that can be reduced is reduced, the adhesive strength between the sealant and the obliquely deposited film is lowered, and the required adhesive strength cannot be obtained, resulting in problems in a drop test, a moisture resistance test, and the like. Next, the oblique deposition film surface that hits the adhesion area of the sealant is masked with a photoresist or the like, then chemically treated with a metal alcoholate, and then the photoresist is peeled off to obliquely strike the adhesion area of the sealant. An obliquely deposited film surface in which metal alcoholate is not chemically bonded to the deposited film surface is obtained. The untreated obliquely deposited film surface has a large critical surface tension, a large amount of surface hydroxyl groups, and the adhesive strength between the sealant and the obliquely deposited film is sufficiently strong, causing problems in drop tests, moisture resistance tests, etc. There is no.

Next, a surface modification method using the metal alcoholate according to the present invention of the vertical alignment films 115 and 125 will be described.
As a pretreatment of the surface treatment with the metal alcoholate of the inorganic oxide vapor-deposited film, it is preferable to perform a heat treatment or vacuum heat treatment of the substrate in order to remove substances such as moisture adsorbed on the oblique vapor deposition substrate. In particular, since moisture inhibits the reaction, it is desirable to remove it by heating. The heat treatment temperature is 100 to 250 ° C, and 200 to 250 ° C that can completely remove the adsorbed moisture is preferable. Moreover, heating temperature can be lowered | hung by heat-processing in a vacuum.

As reaction treatment conditions, selection of the metal alcoholate concentration, reaction temperature, and high-boiling organic solvent is important.
The concentration of the metal alcoholate is 0.001 to 1 mol / L, preferably 0.01 to 0.2 mol / L. When the concentration is 0.001 mol / L or less, the reaction rate is slow, and even when the concentration is 1 mol / L or more, the reaction rate does not increase.
The reaction temperature is 50 to 150 ° C, preferably 60 to 100 ° C. Below 50 ° C., the reaction rate is slow, and above 150 ° C., the metal alcoholate is thermally decomposed.
The properties required for high boiling point organic solvents include:
(1) The boiling point is 80 ° C. or higher.
(2) The metal alcoholate can be dissolved by 0.2 mol / L or more.
(3) Does not chemically react with metal alcoholate, oblique deposition film and ITO film.
Etc.
High-boiling organic solvents that satisfy the above characteristics include alkylbenzenes such as toluene, xylene, ethylbenzene, and diethylbenzene, long-chain alkanes such as decane, dodecane, and tetradecane, and cycloalkanes such as methylcyclohexane, ethylcyclohexane, and p-menthane. . There are ketones such as methyl ethyl ketone and dibutyl ketone, ethers such as dibutyl ether and dihexyl ether, and cyclic ethers such as tetrahydrofuran and dioxane.

Further, the reaction is carried out while stirring or circulating the reaction solution, and the metal alcoholate is easily oxidized with oxygen in the air at a high temperature, and therefore the reaction is preferably performed in an inert gas atmosphere such as nitrogen gas.
The obliquely deposited film substrate subjected to the surface treatment is ultrasonically cleaned using a low boiling point solvent such as alcohol or acetone and then dried at 100 to 200 ° C.

  By processing the upper substrate and the lower substrate on which the vertical alignment films 115 and 125 are formed by the surface modification method, a vertical alignment film chemically surface-treated with a metal alcoholate can be formed.

  According to the liquid crystal display element 100 as described above, it is possible to prevent the time-dependent expansion of the alignment abnormal region that occurs when the liquid crystal display element is sealed, to alleviate the image sticking phenomenon, and to have high light resistance, which is extremely reliable. It is a highly liquid crystal display element.

(Example 1)
Two glass substrates (2.5 cm × 2.5 cm square) were prepared, and the substrate was set in a vacuum vapor deposition apparatus so that the substrate surface was 50 degrees with respect to the vapor deposition source. The inside vapor deposition apparatus and obliquely evaporated from a vacuum of SiO ₂ to a thickness of 400 Å, was created SiO ₂ oblique deposition film coated substrate.

As a compound for surface treatment, a compound of R ₁ = C ₁₇ H ₃₅ , X = —COO—, M = titanium, R ₂ = (CH ₃ ) ₂ CH—, m = 1, n = 3 A certain KRTTS (manufactured by Ajinomoto Fine Techno Co., Ltd.) was used. 0.01 mol of this compound was weighed into a beaker, 200 ml of xylene was added and dissolved by stirring to make a 0.1M xylene solution of KRTTS.

This solution is heated to 80 ° C. with a mantle heater, then placed on the bottom of the beaker with the SiO ₂ vapor-deposited surface of the substrate with the vapor-deposited film on top, and stirred for 1 hour at a temperature range of 75 to 85 ° C. The surface of the SiO ₂ vapor deposition film was chemically surface-treated with KRTTS. The surface-treated substrate was ultrasonically cleaned in ethanol and then dried in an oven at 120 ° C. for 1 hour.

Thermosetting adhesive ML3804P (manufactured by Nippon Kayaku Co., Ltd.) made of an epoxy resin in which silica spheres having a diameter of about 3 μm are mixed in a portion other than the liquid crystal inlet on the outer periphery of the SiO ₂ vapor deposition surface on one surface-treated substrate with a vapor deposition film ) And heated at 80 ° C. for 10 minutes to remove the solvent. And the SiO ₂ deposition surface of the deposition film-coated substrate treated other surface inward, deposition direction of the two deposited film-coated substrate is arranged such that 180 degrees, while crimping the two substrates with a clip Bonding was performed by heating at 140 ° C. for 1 hour.

Fluorine-based liquid crystal with negative dielectric anisotropy MLC-6610 (manufactured by Merck & Co., Inc.) was injected from the injection port into the inner space where these two substrates were bonded together by a vacuum injection method. Thereafter, the injection port using a UV adhesive LPD-204 acrylic (manufactured by Henkel Japan), the UV wavelength 365nm hardened 3000 mJ / cm ² irradiation to, of SiO ₂ were chemically textured in KRTTS A vertical alignment type liquid crystal cell using an obliquely deposited alignment film was prepared. FIG. 5 shows a plan view of the liquid crystal cell thus produced.

As a result of the alignment stability test, the liquid crystal cell thus prepared was left in a thermostat at 80 ° C., and the width of the liquid crystal alignment abnormal region at the seal 105 was measured after 0 hours, 500 hours, and 1000 hours. The results are shown in Table 1.
As a burn-in test, the C (electric capacity) -V (applied voltage) characteristic of the liquid crystal cell was measured while raising and lowering V and the voltage measured while raising and lowering V in an oven at 60 ° C. The results of measuring the difference ΔV are shown in Table 2. Here, as schematically shown in FIG. 6, ΔV is represented by the difference between the V values corresponding to the center value of the maximum value and the minimum value of C when V is raised and lowered.

  Further, as a light resistance test, the above-mentioned liquid crystal cell is set at the position of the liquid crystal light modulator 824 for blue light of the projection type display device of this embodiment in FIG. 7, and the surface temperature of the liquid crystal cell is kept at 70 ° C. Table 3 shows the results of measuring the time until a display abnormality occurs by continuously lighting a 130 WUHP lamp (manufactured by Philips) as the light source 810.

(Example 2)
As a compound for surface treatment, R ₁ = C ₁₇ H ₃₅ , X = —CO—CH═CH (CH ₃ ) —, M = aluminum, R ₂ = (CH ₃ ) ₂ CH—, m = 1. A liquid crystal cell was prepared in the same manner as in Example 1 except that 0.01 mol of AL-M (manufactured by Ajinomoto Fine Techno Co., Ltd.), which is a compound of n = 2, was used, and an alignment stability test and a burn-in test were performed. The results of the light resistance test are shown in Tables 1, 2 and 3.

(Example 3)
1 mol of tetraisopropoxyzirconium and 1.2 mol of cholestanol were dissolved in 1 L of octane. The solution was stirred at 100 ° C. for 5 hours while stirring. The reaction solution thus obtained was concentrated using a reduced-pressure evaporator, and R ₁ = cholestanyl, X═O, M = zirconium, R ₂ = (CH ₃ ) ₂ CH—, m = A compound of 1, n = 3 was obtained. A liquid crystal cell was prepared in the same manner as in Example 1 except that 0.01 mol of this compound was used as the surface treatment compound, and the results of alignment stability test, image sticking test and light resistance test are shown in Tables 1 and 2. And 3.

(Example 4)
1 mol of tetraisopropoxytitanium and 2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,11-henikosafluoro- 1.2 mol of 1-undecanol was dissolved in 1 L of octane. The solution was stirred at 80 ° C. for 2 hours while stirring. The reaction solution thus obtained was concentrated using a vacuum evaporator, and R ₁ = 2,2,3,4,4,5,5,6,6,7,7 in (Chemical formula 6). , 8,8,9,9,10,10,11,11,11- Henikosafuruoro-1-undecyl, X = O, M = _{titanium, R 2 = (CH 3)} 2 CH-, m = 1, n = 3 compounds were obtained. A liquid crystal cell was prepared in the same manner as in Example 1 except that 0.01 mol of this compound was used as the surface treatment compound, and the results of alignment stability test, image sticking test, and light resistance test are shown in Tables 1 and 2. And 3.

(Example 5)
Two glass substrates (2.5 cm × 2.5 cm square) were prepared, and the substrate was set in a vacuum vapor deposition apparatus so that the substrate surface was 50 degrees with respect to the vapor deposition source. The inside vapor deposition apparatus and obliquely evaporated from a vacuum of SiO ₂ to a thickness of 400 Å, was created SiO ₂ oblique deposition film coated substrate.
A positive photoresist is applied onto the obliquely deposited film surfaces of the two substrates using a spinner, the seal portion and the sealing portion are masked, exposed using an exposure machine, and developed with an organic alkaline solution. A substrate with a SiO ₂ oblique vapor deposition film was prepared by peeling off the photoresist other than the seal portion and masking the seal portion and the sealing portion with the photoresist.

As a compound for surface treatment, a compound of R ₁ = C ₁₇ H ₃₅ , X = —COO—, M = titanium, R ₂ = (CH ₃ ) ₂ CH—, m = 1, n = 3 A certain KRTTS (manufactured by Ajinomoto Fine Techno Co., Ltd.) was used. 0.01 mol of this compound was weighed into a beaker, 200 ml of xylene was added and dissolved by stirring to make a 0.1M xylene solution of KRTTS.

This solution is heated to 80 ° C. with a mantle heater, then placed on the bottom of the beaker with the SiO ₂ vapor-deposited surface of the substrate with the vapor-deposited film on top, and stirred for 1 hour at a temperature range of 75 to 85 ° C. The surface of the SiO ₂ vapor deposition film was chemically surface-treated with KRTTS. The surface-treated substrate was ultrasonically cleaned in ethanol. This substrate was re-exposed using an exposure machine and then developed with an organic alkali solution to peel off the seal part and the photoresist on the sealing part. Next, the substrate was ultrasonically cleaned in ethanol and then dried in an oven at 120 ° C. for 1 hour.

Thermosetting adhesive ML3804P (manufactured by Nippon Kayaku Co., Ltd.) made of an epoxy resin in which silica spheres having a diameter of about 3 μm are mixed in a portion other than the liquid crystal inlet on the outer periphery of the SiO ₂ vapor deposition surface on one surface-treated substrate with a vapor deposition film ) And heated at 80 ° C. for 10 minutes to remove the solvent. And the SiO ₂ deposition surface of the deposition film-coated substrate treated other surface inward, deposition direction of the two deposited film-coated substrate is arranged such that 180 degrees, while crimping the two substrates with a clip Bonding was performed by heating at 140 ° C. for 1 hour.

Fluorine-based liquid crystal with negative dielectric anisotropy MLC-6610 (manufactured by Merck & Co., Inc.) was injected from the injection port into the inner space where these two substrates were bonded together by a vacuum injection method. Thereafter, the injection port was cured and sealed by irradiating 3000 mJ / cm ² of UV with a wavelength of 365 nm using an acrylic UV adhesive LPD-204 (manufactured by Henkel Japan), and was chemically surface-treated with KRTTS. A vertical alignment type liquid crystal cell using _two obliquely deposited alignment films was prepared.
As a moisture resistance test, the liquid crystal cell thus prepared was left in a constant temperature and humidity chamber at 60 ° C. and a humidity of 90%, and the occurrence of alignment abnormality was observed. It was.

(Comparative Example 1)
A liquid crystal cell was prepared in the same manner as in Example 1 except that SiO ₂ without surface treatment was used, and the results of alignment stability test, image sticking test, and light resistance test are shown in Tables 1, 2 and 3. It was.

(Comparative Example 2)
A liquid crystal cell was prepared in the same manner as in Example 1 except that 1.86 g (0.01 mol) of dodecanol was used as the surface treatment compound, and the results of the alignment stability test, image sticking test, and light resistance test were obtained. The results are shown in Tables 1, 2 and 3.

(Comparative Example 3)
When the liquid crystal cell produced in Example 1 was left in a constant temperature and humidity chamber at 60 ° C. and a humidity of 90% and observed for occurrence of alignment abnormality, alignment abnormality was observed during sealing in 250 hours.

In Comparative Example 1, SiO ₂ that is not subjected to surface treatment is used, and the vertical anchoring force is considerably weak because it is oriented only by the dispersion force anisotropy of liquid crystal molecules and the topological effect of the SiO ₂ surface. Further, since a large number of highly polar hydroxyl groups are present on the SiO ₂ surface, polar substances are likely to be adsorbed, and it is considered that the amount of adsorption of polar impurities such as stabilizers and initiators derived from the sealant is large. For these reasons, the alignment stability is lacking, and the enlargement speed of the liquid crystal alignment abnormal region is very large. Further, a large number of highly polar hydroxyl groups exist on the surface of SiO ₂ , and most of them are dissociated and ionized negatively, so that ionic impurities in the liquid crystal are easily adsorbed and a seizure phenomenon easily occurs. Is very big. Further, in the light resistance test, SiO ₂ is an inorganic substance and has high light resistance because it has no absorption in the visible and near ultraviolet light regions.

In Comparative Example 2, SiO ₂ surface-treated with 1-dodecanol is used, and since the majority of OH on the surface of SiO ₂ is alkylated to reduce the polarity, the amount of adsorption of polar impurities derived from the sealant is reduced. Yes. However, since the difference in surface tension between the long chain alkyl group on the SiO ₂ surface and the liquid crystal molecule terminal alkyl group is small, the vertical anchoring force is insufficient. For this reason, the enlargement speed of the liquid crystal alignment abnormal region is greatly reduced as compared with the case of using SiO ₂ which is not subjected to the surface treatment of Comparative Example 1, but it is not yet a satisfactory value. Further, since the partially remaining surface OH is dissociated and ionized negatively in the same manner as in Comparative Example 1, the ionic impurity in the liquid crystal is adsorbed to cause a burn-in phenomenon, but ΔV is small. Furthermore, although in the light resistance test 1-dodecanol is an organic compound, carbon - carbon and carbon - light resistance because no absorption in the short wavelength visible light region consists single bond oxygen SiO ₂ is not performed to a surface treatment Not inferior.

In Examples 1 to 4, SiO ₂ surface-treated with a metal alcoholate according to the present invention is used, and the hydroxyl group on the SiO ₂ surface reacts with a metal alcoholate having a low electronegativity to reduce the surface polarity. Compared with the case of using long-chain alkylated SiO ₂ in Example 2, the amount of polar impurities adsorbed from the sealant is further reduced, so that the vertical anchoring force is strong and the expansion speed of the liquid crystal alignment abnormal region is small. In addition, since the hydroxyl group generated by hydrolysis of the metal alcoholate has an isoelectric point of aluminum, titanium and zirconium close to pH 7 in the liquid crystal cell, ionization is suppressed, and the amount of ions adsorbed in the liquid crystal is small. Is very small and the seizure phenomenon is greatly reduced. In the light resistance test, the alkyl group, the steroid and the fluoroalkyl group are organic compounds, but the light resistance is comparable to SiO _{2 which} is not subjected to surface treatment since it does not absorb in the short wavelength visible light region.

  From Example 5 and Comparative Example 3, a significant difference was observed in the moisture resistance test depending on the presence or absence of chemical treatment with the metal alcoholate of the seal part and the seal part. The chemical treatment with the metal alcoholate reduces the adhesive strength between the sealant and the oblique vapor deposition film, and moisture easily enters the liquid crystal cell through the interface between the sealant and the oblique vapor deposition film.

[Second Embodiment]

  The second embodiment of the present invention will be described below with reference to the drawings. Here, an example of a liquid crystal projector (projection display device) using the liquid crystal display element 100 of the first embodiment as a light modulation device will be described. Since the liquid crystal display element 100 of the first embodiment has high light resistance and alignment stability, it is preferably used as a light modulation device of a liquid crystal projector (projection display device).

  FIG. 7 is a schematic configuration diagram showing a main part of the projection display device of the present embodiment. In FIG. 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, 822, 823 and 824 are liquid crystal light modulators, Reference numeral 825 denotes a cross dichroic prism, and reference numeral 826 denotes a projection lens.

  The light source 810 includes a lamp 811 such as a metal halide or ultra-high pressure mercury and a reflector 812 that reflects the light of the lamp. The dichroic mirror 813 that reflects blue light and green light transmits red light out of the light flux from the light source 810 and reflects blue light and green light. The transmitted red light is reflected by the reflection mirror 817 and enters the liquid crystal light modulator for red light 822 including the liquid crystal display element 100 of the first embodiment.

  On the other hand, green light out of the color light reflected by the dichroic mirror 813 is reflected by the dichroic mirror 814 that reflects green light and enters the liquid crystal light modulator 823 for green light that includes the liquid crystal display element 100 of the first embodiment. . Note that the blue light also passes through the second dichroic mirror 814. For blue light, 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 in order to compensate for the difference in optical path length from green light and red light. Through this, the blue light is incident on the blue light liquid crystal light modulation device 824 including the liquid crystal display element 100 of the first embodiment.

  The three color lights modulated by the respective light modulation devices 822, 823, and 824 are incident on the cross dichroic prism 825. In this prism, four right-angle prisms are bonded together, and a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are formed in a cross shape on the inner surface. 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 display device of this embodiment having such a structure includes the liquid crystal display element 100 of the first embodiment, it has excellent durability and can maintain display quality over a long period of time. It becomes a display device.

FIG. 3 is an equivalent circuit diagram of the liquid crystal display element according to the first embodiment of the present invention. FIG. 2 is a schematic plan view showing a pixel configuration of the liquid crystal display element. The cross-sectional schematic diagram which shows the principal part of a liquid crystal display element. Explanatory drawing which shows the structure of a vapor deposition apparatus. The plane schematic diagram which shows the liquid crystal cell of an Example. The graph which shows the definition of (DELTA) V. The conceptual diagram shown about the projection type display apparatus of 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 ... Upper substrate, 102 ... Lower substrate, 104 ... Liquid crystal layer, 106 ... Sealing, 113 ... Common electrode, 115, 125 ... Vertical alignment film (alignment film), 123 ... Pixel electrode, 130 ... ITO electrode.

Claims (5)

  A liquid crystal display element using a vertical alignment film composed of an obliquely deposited inorganic oxide film, wherein a surface hydroxyl group of the obliquely deposited film is chemically treated with a metal alcoholate. The liquid crystal display element according to claim 1, wherein the metal alcoholate is represented by the following (Chemical Formula 1).

However, in (Chemical Formula 1), R ₁ is a linear or branched alkyl group having 6 to 30 carbon atoms, a linear or branched fluorinated alkyl group having 6 to 30 carbon atoms, or a steroid or a derivative thereof. Is a single bond, —O—, —OCO—, —COO—, —CO—, —CH (CH ₃ ) ═C—CO—, —PO—, or —OPO (OH) PO (O—) ₂ , M is aluminum, titanium, or zirconium, and R ₂ is a linear or branched alkyl group having 1 to 6 carbon atoms, a linear or branched alkyl alkylene group having 1 to 4 carbon atoms, or —CH ₂ CO—. Where m is an integer from 1 to 3 and n is an integer from 1 to 3.   3. The liquid crystal display element according to claim 1, wherein a surface hydroxyl group of the oblique deposition film is chemically reacted with a metal alcoholate in a selective planar region.   A method for manufacturing a liquid crystal display device using a vertical alignment film comprising an orthorhombic vapor-deposited film of an inorganic oxide whose surface hydroxyl group is chemically reacted with a metal alcoholate, wherein the orthorhombic vapor-deposited film comprises the metal alcoholate and a high-boiling point film. A method of manufacturing a liquid crystal display element, comprising forming an obliquely deposited film of a surface-treated inorganic oxide by a heating step in which a chemical reaction is carried out by heating in a solution comprising an organic solvent. 4. A projection display device comprising the liquid crystal display element according to claim 1 as a light modulation device.

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