JP2007156054A - Liquid crystal device, method of manufacturing liquid crystal device, and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal device which is capable of preventing display defects caused by fluorinated acid and display defects caused by aggregation of particles in liquid crystal and is superior in durability to obtain excellent alignment characteristics for a long period of time. <P>SOLUTION: The liquid crystal device has liquid crystal held between a pair of substrates, and the liquid crystal contains fine particles 55 made of a basic oxide and a polymer network formed by polymerizing liquid crystalline monomers. It is preferable that a particles size of the fine particles is 5 to 100 nm and the liquid crystal contains 0.01 to 5 wt.% fine particles 55. <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 an electronic device, and more particularly, to a liquid crystal device excellent in durability capable of obtaining excellent alignment characteristics over a long period of time.

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 is provided with an alignment film that controls the alignment direction of liquid crystal sandwiched between a pair of substrates. However, the alignment force of the alignment film is reduced by long-term use. In particular, in a liquid crystal projector irradiated with high-intensity light, the alignment film is easily denatured by light and heat from a light source, so that display defects are likely to occur and durability is poor.

In order to solve this problem, for example, a technique for improving the light resistance and heat resistance of the alignment film by using an inorganic alignment film has been proposed (for example, see Patent Document 1). In order to solve this problem, a technique has been proposed in which superabsorbent particles are dispersed in liquid crystal or on a transparent substrate so that moisture in the liquid crystal is absorbed by superabsorbent particles so that display defects do not occur. (For example, refer to Patent Document 2). In addition, as a technique for containing a predetermined amount of particles in a liquid crystal, Patent Document 3 discloses a technique in which magnesium oxide particles are contained in a polymer-dispersed liquid crystal film in which liquid crystals are dispersed in a water-soluble polymer matrix. Proposed.
Japanese Patent Laid-Open No. 7-20468 JP-A-6-167698 JP-A-8-227070

However, in the technique described in Patent Document 1, when a liquid crystal molecule into which a fluorine-based substituent is introduced is included in the liquid crystal, the inorganic alignment film is eroded by hydrofluoric acid generated from a liquid crystal photolysis product, The problem is that display defects of liquid crystal devices occur. In particular, an inorganic alignment film mainly composed of SiO ₂ has a problem because its ability to align liquid crystals is reduced when it is eroded by hydrofluoric acid.
Further, the techniques described in Patent Document 2 and Patent Document 3 are difficult to use for a long period of time because the particles tend to aggregate and the particles in the liquid crystal settle to cause display defects.

The present invention has been made in view of the above problems, and can prevent display defects due to hydrofluoric acid and display defects due to aggregation of particles in liquid crystals, and has excellent alignment characteristics over a long period of time. An object is to provide a liquid crystal device having excellent durability.
It is another object of the present invention to provide a method for manufacturing the liquid crystal device of the present invention that provides excellent alignment characteristics over a long period of time, and an electronic apparatus including the liquid crystal device of the present invention.

In order to achieve the above object, a liquid crystal device of the present invention is a liquid crystal device in which a liquid crystal is sandwiched between a pair of substrates, and the liquid crystal includes fine particles made of a basic oxide and liquid crystal properties. And a polymer network obtained by polymerizing monomers.

According to the liquid crystal device of the present invention, since the liquid crystal contains a polymer network, the fine particles made of a basic oxide are prevented from agglomerating and settling in the liquid crystal, and the fine particles are liquid crystal. It will be stably dispersed inside.
The fine particles made of a basic oxide are capable of neutralizing and absorbing hydrofluoric acid. In the liquid crystal device of the present invention, hydrofluoric acid is effectively neutralized and absorbed by the fine particles of the basic oxide that are stably dispersed, so that display defects caused by hydrofluoric acid are unlikely to occur. Therefore, the liquid crystal device of the present invention has excellent durability that provides excellent alignment characteristics over a long period of time.
Therefore, in the liquid crystal device of the present invention, for example, when a liquid crystal molecule into which a fluorine-based substituent is introduced is included in the liquid crystal, and the liquid crystal device includes an inorganic alignment film mainly composed of SiO ₂ , Even if hydrofluoric acid is generated from the photodecomposition product of liquid crystal, erosion of the inorganic alignment film due to hydrofluoric acid can be prevented.

In the above liquid crystal device, the polymer network may be adsorbed on the fine particles.
By using such a liquid crystal device, the fine particles can be more effectively prevented from aggregating and settling in the liquid crystal, and the fine particles are more stably dispersed in the liquid crystal. .

In the liquid crystal device, the fine particles are contained in the liquid crystal in an amount of 0.01 wt% to 5 w.
t% may be included.
By using such a liquid crystal device, an increase in driving voltage due to the inclusion of fine particles in the liquid crystal can be suppressed sufficiently small, and an effect of absorbing hydrofluoric acid can be sufficiently obtained. .

In the above liquid crystal device, the polymer network is 0.1 wt% in the liquid crystal.
˜5 wt% may be included.
By setting it as such a liquid crystal device, it is possible to sufficiently suppress an increase in unnecessary scattering of visible light and an increase in driving voltage due to the polymer network being included in the liquid crystal, and
The effect of improving the dispersion stability of the fine particles is sufficiently obtained, and the effect of absorbing hydrofluoric acid is sufficiently obtained.

In the liquid crystal device described above, an alignment film that mainly includes silicon oxide and controls the alignment of the liquid crystal is provided on the liquid crystal side surface of at least one of the pair of substrates. Can do.
In the present specification, “mainly” means that the content is the highest among the constituent components. By using such a liquid crystal device, an alignment film having excellent light resistance and heat resistance is provided.

In order to achieve the above object, a method for manufacturing a liquid crystal device according to the present invention is a method for manufacturing a liquid crystal device in which a liquid crystal is sandwiched between a pair of substrates. And a polymerizing step of polymerizing the liquid crystalline monomer to form a polymer network.
According to the method for producing a liquid crystal device of the present invention, hydrofluoric acid is effectively neutralized and absorbed by fine particles made of a stably dispersed basic oxide, and excellent alignment characteristics can be obtained over a long period of time. A liquid crystal device having excellent durability can be manufactured.

In the method for manufacturing a liquid crystal device, the liquid crystalline monomer can be adsorbed on the fine particles before the dispersion step.
According to such a method for manufacturing a liquid crystal device, the number of polymer networks adsorbed on the fine particles can be increased, so that aggregation and settling of the fine particles in the liquid crystal can be more effectively suppressed, and the fine particles A liquid crystal device that is more stably dispersed in the liquid crystal can be manufactured.

In the method for manufacturing the liquid crystal device, a method in which a polymerization initiator is adsorbed on the fine particles can be used before the dispersion step.
According to such a method for manufacturing a liquid crystal device, the number of polymer chains of the polymer network arranged in the vicinity of the fine particles can be increased, and the number of polymer networks adsorbed on the fine particles can be increased. Therefore, aggregation and sedimentation of the fine particles in the liquid crystal can be more effectively suppressed, and a liquid crystal device in which the fine particles are more stably dispersed in the liquid crystal can be manufactured.

In order to achieve the above object, an electronic apparatus according to the present invention includes any one of the above liquid crystal devices.
According to such an electronic device, it is possible to provide an electronic device with excellent durability that can provide good display performance over a long period of time.

Hereinafter, an embodiment of the present invention will be described as an example. In the following description, various structures are illustrated using drawings, but the structures shown in these drawings may be shown with different dimensions from the actual structures in order to show the characteristic parts in an easy-to-understand manner. is there.
In this embodiment, 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.

(Liquid crystal display device)
First, the configuration of the liquid crystal device 100 will be described. FIG. 1 is a plan view of the liquid crystal device 100 as viewed from the counter substrate side together with the respective components. FIG. 2 is a cross-sectional view of the liquid crystal device 100 taken along the line HH ′ shown in FIG. FIG. 3 is a diagram illustrating an equivalent circuit 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 100. FIG. 4 is an enlarged view showing a cross-sectional structure of the liquid crystal device 100.

As shown in FIGS. 1 and 2, the liquid crystal display device 100 according to the present embodiment includes a TFT array substrate 10 and a counter substrate 20 bonded together by a sealing material 52, and a liquid crystal 50 in a region partitioned by the sealing material 52. Is enclosed. 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.

In the liquid crystal display device 100, the type of liquid crystal used, that is, TN (Twis
Depending on the operation mode such as ted Nematic) mode, STN (Super Twisted Nematic) mode, and normally white mode / normally black mode, a retardation plate, a polarizing plate, etc. are arranged in a predetermined direction. Then, illustration is abbreviate | omitted.

In such an image display area of the liquid crystal display device 100, 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 TFT 30. The pixel signals S1, S2,.
, Sn is electrically connected to the source of the TFT 30. Also,
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. ing. The pixel electrode 9 is electrically connected to the drain of the TFT 30, and the data line 6a is turned on by turning on the TFT 30 as a switching element for a certain period.
, Sn supplied from the above are written to each pixel at a predetermined timing.
In this way, pixel signals S1, S2 of a predetermined level written to the liquid crystal through the pixel electrode 9
,..., Sn is held for a certain period with the counter electrode 21 of the counter substrate 20 shown in FIG. Further, in order to prevent the retained pixel signals S1, S2,..., Sn from leaking, the pixel electrode 9
A storage capacitor 60 is added in parallel with the liquid crystal capacitor formed between the electrode 21 and the counter electrode 21. Reference numeral 3 b denotes a capacity line constituting the storage capacity 60.

Also, as shown in FIG. 4, on the inner surface of the TFT array substrate 10, pixel electrodes 9 made of a transparent conductive film such as TFT 30 and ITO are provided for each pixel 100a arranged in a matrix. . Actually, wirings such as the data line 6a and the scanning line 3a are formed, but these are not shown in FIG. An alignment film 1 for controlling the alignment of the liquid crystal 50 is provided on the inner surface of the TFT array substrate 10 so as to cover the TFT 30 and the pixel electrode 9 over the entire image display area.

A light shielding film 23 is provided on the inner surface of the counter substrate 20. The light shielding film 23 is a TFT 30
And wirings (data lines 6a, scanning lines 3a, etc.) are provided in a grid pattern along the edge of each pixel 100a. The area where the illumination light is blocked by the light shielding film 23 is a non-illumination area,
An area where the illumination light is transmitted through the opening of the light shielding film 23 is an illumination area. A counter electrode 21 made of a transparent conductive film such as ITO is provided on the entire inner surface of the counter substrate 20 so as to cover the light shielding film 23, and the orientation of the liquid crystal 50 is controlled so as to cover the counter electrode 21. The alignment film 2 is provided over the entire image display area.

The alignment films 1 and 2 are mainly composed of silicon oxide (silica) which is an inorganic material component. The alignment films 1 and 2 are obliquely deposited films of silicon oxide and have surfaces 1a and 2a made of columnar structures oriented in a predetermined direction.

The alignment films 1 and 2 may be formed by a sol-gel method using an alignment film forming liquid (sol solution). In this case, the alignment films 1 and 2 are etched by irradiation with a beam having directivity such as ion beam etching, for example, so that the surfaces 1a and 2a of the fine alignment structure (uneven structure) excellent in uniaxial alignment are obtained. Can be provided.
As ion sources used for ion beam etching, for example, Ne, Ar, Kr
An inert gas such as Xe, a fluorocarbon gas such as CHF ₃ or CF ₄ , a chlorine gas, or the like can be used. Of these, it is generally preferable to use inexpensive and efficient Ar. A
Since r is an inert gas, the ion source is simple and can be used without countermeasures against corrosion. Further, the chlorofluorocarbon gas can selectively etch SiO ₂ with F radicals and generates less contamination.

A liquid crystal 50 is held between the substrates 10 and 20. In the liquid crystal display device 100 of the present embodiment, the liquid crystal 50 includes fine particles made of a basic oxide and a polymer network.
FIG. 5 is a schematic diagram for explaining a polymer network in the liquid crystal constituting the liquid crystal display device of the present embodiment. In FIG. 5, the code | symbol 51 has shown the liquid crystal molecule. The polymer network in the liquid crystal 50 includes polymer chains 54 obtained by polymerizing liquid crystal monomers. Polymer chain 5
4 includes an alignment portion 54a that is aligned with the liquid crystal and a bonding portion 54b that forms a bond of the polymer network.

FIG. 6 is a schematic diagram for explaining the relationship between the fine particles in the liquid crystal constituting the liquid crystal display device of the present embodiment and the polymer network. In FIG. 6, the liquid crystal molecules are not shown for easy viewing of the drawing. In FIG. 6, reference numeral 54 c denotes an oriented portion 54 arranged at the end of the polymer chain 54 among the polymer chains 54 constituting the polymer network.
a indicates an adsorbed polymer chain adsorbed on the surface 55 a of the fine particle 55 in the liquid crystal 50. The adsorbing polymer chain 54c effectively prevents the fine particles 55 from aggregating and settling in the liquid crystal, and improves the dispersion stability of the fine particles 55 in the liquid crystal 50. Therefore, in order to improve the dispersion stability of the fine particles 55 in the liquid crystal 50, the adsorbed polymer chain 5
The larger the number of 4c, the better.

The polymer network is preferably contained in the liquid crystal 50 in an amount of 0.1 wt% to 5 wt%, and more preferably 0.1 wt% to 3 wt%. If the polymer network contained in the liquid crystal 50 is less than 0.1 wt%, the effect of improving the dispersion stability of the fine particles 55 in the liquid crystal 50 may not be sufficiently obtained. In addition, if a polymer network exceeding 3 wt% is included in the liquid crystal 50, an increase in unnecessary scattering of visible light due to the polymer network being included in the liquid crystal becomes remarkable, and the transmittance is low. This is not desirable. Furthermore, if a polymer network exceeding 5 wt% is included in the liquid crystal 50, an increase in driving voltage due to the polymer network being included in the liquid crystal becomes remarkable, which is not desirable.
The content of the polymer network in the liquid crystal 50 is the same as the content (concentration) in the liquid crystal 50 before polymerization of the liquid crystalline monomer that is a raw material of the polymer network.

As the polymer chain 54, one obtained by polymerizing any one or plural kinds of liquid crystalline monomers represented by the following general formulas (1), (2), and (3) can be used.

Specific examples of the compound represented by the general formula (1) shown in Chemical Formula 1 include compounds M1 to M25 (UV curable liquid crystal manufactured by Rodick Co., Ltd.) shown in Table 1 or Table 2. be able to. Moreover, as a compound represented by General formula (2) shown in the said Chemical formula 2,
Specifically, compounds M26 to M33, M38 to M45 and the like shown in Table 3 or Table 5 can be exemplified. Specific examples of the compound represented by the general formula (3) shown in Chemical Formula 3 include compounds M34 to M37 and M46 to M51 shown in Table 4 or Table 6.

In addition to Table 1 and Table 2, for example, liquid crystalline monomers represented by the general formula (A) of the following chemical formula 4 may be used alone or in combination.

In the general formula (A), Y1 and Y2 each represent a methacrylate group, an acrylate group, a hydrogen atom, an alkyl group, an alkoxy group, a fluorine atom, or a cyano group, and at least one of Y1 and Y2 is a methacrylate group. Or an acrylate group, A1 is not present and benzene rings on both sides thereof are directly connected by a single bond, or A1 is a group represented by any one of the following general formulas (B) to (E) Or an oxygen atom or a sulfur atom, and all the hydrogen atoms of the benzene rings on both sides of A1 may be hydrogen atoms, or at least one hydrogen atom may be substituted with a halogen atom. .

In addition to the above, the liquid crystalline monomer used in the present invention has a liquid crystal phase itself, or does not have a liquid crystal phase itself, but does not break the liquid crystal phase even when mixed with liquid crystal. Things can be used.

Here, with reference to FIG. 7 and FIG. 8, an example of a polymer chain obtained by polymerizing a liquid crystalline monomer is described with respect to the alignment portion and the binding portion of the polymer chain constituting the liquid crystal display device of the present embodiment. To do.
The n liquid crystalline monomers shown in FIG. 7A are denoted by reference numeral 5 in the schematic diagram shown in FIG.
This is indicated by 4d. When n liquid crystalline monomers 54d are polymerized, a polymer chain shown in FIG. 7B is obtained. The polymer chain shown in FIG. 7 (b) is denoted by reference numeral 54 in FIG. 7 (c), and the orientation portion of the polymer chain 54 is denoted by reference numeral 54a in FIGS. 7 (b) and 7 (c). 7 (b) and 7 (c), the binding portion of the polymer chain 54 is indicated by reference numeral 54b.
In the polymer chain 54 shown in FIG. 7, the number of orientation portions 54a and the number of coupling portions 54b are the same.

Further, the n liquid crystalline monomers shown in FIG. 8A are indicated by reference numeral 54d in the schematic diagram shown in FIG. 8C. When n liquid crystalline monomers 54d are polymerized, FIG.
) Is obtained. The polymer chain shown in FIG. 8B is denoted by reference numeral 5 in FIG.
In FIG. 8B and FIG. 8C, the orientation portion of the polymer chain 54 is denoted by reference numeral 54.
In FIG. 8B and FIG. 8C, the binding portion of the polymer chain 54 is denoted by reference numeral 54.
Indicated by b.
In the polymer chain 54 shown in FIG. 8, the number of coupling portions 54b is two with respect to the number of orientation portions 54a. Therefore, in the example shown in FIG. 8C, the density of the coupling portion 54b is higher than in the example shown in FIG. 7C, and the dispersion stability of the fine particles 55 in the liquid crystal 50 is effectively improved. Can do.

Further, as the fine particles 55 made of a basic oxide, for example, at least one of alkaline earth metals selected from magnesium oxide, calcium oxide, strontium oxide, and barium oxide can be mainly used. In particular, when the fine particles 55 are magnesium oxide and / or calcium oxide, hydrofluoric acid can be efficiently neutralized and absorbed, and the ability to align the liquid crystal 50 of the alignment films 1 and 2 is effectively reduced. Can be prevented. The fine particles 55 are porous and have a large surface area so that the polymer chains 54 can be easily adsorbed, can promote the formation of the adsorbed polymer chains 54c, and can promote the absorption of hydrofluoric acid. Is desirable.

The particle size of the fine particles 55 made of a basic oxide is preferably 5 nm to 100 nm, and more preferably about 30 to 50 nm in average particle size. The particle size of the fine particles 55 is 5 nm.
If it is less than this, there is a possibility that the effect of the fine particles 55 not sufficiently absorbing hydrofluoric acid cannot be obtained. On the other hand, if the particle size of the fine particles 55 exceeds 100 nm, the increase in unnecessary scattering of visible light due to the inclusion of the fine particles 55 and the surrounding polymer network in the liquid crystal becomes remarkable.

The fine particles 55 are desirably contained in the liquid crystal 50 by 0.01 wt% to 5 wt%.
If the fine particles 55 contained in the liquid crystal 50 are less than 0.01 wt%, the fine particles 55 may not be sufficiently effective in absorbing hydrofluoric acid. In addition, if the fine particles 55 exceeding 5 wt% are included in the liquid crystal 50, an increase in driving voltage due to the inclusion of the fine particles 55 in the liquid crystal becomes remarkable, which is not desirable.

As the liquid crystal material constituting the liquid crystal 50, any liquid crystal material may be used as long as it can be aligned such as nematic liquid crystal and smectic liquid crystal. However, in the case of a TN type liquid crystal panel, a liquid crystal material that forms nematic liquid crystal is preferable. Examples of nematic liquid crystals include phenylcyclohexane derivative liquid crystals, biphenyl derivative liquid crystals, biphenylcyclohexane derivative liquid crystals, terphenyl derivative liquid crystals, phenyl ether derivative liquid crystals, phenyl ester derivative liquid crystals, bicyclohexane derivative liquid crystals, azomethine derivative liquid crystals, azoxy derivative liquid crystals, and pyrimidines. Derivative liquid crystals, dioxane derivative liquid crystals, cubane derivative liquid crystals, and the like can be given. further,
These nematic liquid crystal molecules also include liquid crystal molecules in which a fluorine-based substituent such as a monofluoro group, difluoro group, trifluoro group, trifluoromethyl group, trifluoromethoxy group, or difluoromethoxy group is introduced. It is preferable that the liquid crystal material includes liquid crystal molecules into which a fluorine-based substituent is introduced because high voltage holding characteristics suitable for the active matrix and high dielectric anisotropy for realizing a low driving voltage can be obtained.

In the liquid crystal device 100 of this embodiment, even if hydrofluoric acid is generated from a photodecomposition product of liquid crystal molecules into which a fluorine-based substituent has been introduced, the fine particles 55 made of a basic oxide contained in the liquid crystal 50 do not contain hydrofluoric acid. Since neutralization and absorption are performed, the alignment films 1 and 2 are prevented from being eroded by hydrofluoric acid. Therefore, according to the present invention, it is possible to realize the liquid crystal device 100 having both good alignment characteristics and high reliability.

(Manufacturing method of liquid crystal device)
Next, a method for manufacturing the above-described liquid crystal device 100 will be described.
The liquid crystal device 100 described above is formed by sticking the one in which the alignment film 1 is formed on the surface of the TFT array substrate 10 and the one in which the alignment film 2 is formed on the surface of the counter substrate 20 via the sealing material 52 provided in a frame shape. In addition, after filling the frame of the sealing material 52 with liquid crystal, it can be produced by sticking a polarizing plate or the like to the outer surfaces of the substrates 10 and 20 as necessary.

Below, the process of forming the liquid crystal 50 which comprises the liquid crystal device 100 mentioned above is demonstrated in detail. In order to form the liquid crystal 50 constituting the liquid crystal device 100, first, the fine particles 55 and the liquid crystalline monomer are dispersed in the liquid crystal (dispersing step).
Then, the obtained liquid crystal in which the fine particles 55 and the liquid crystalline monomer are dispersed is filled in a frame of the sealing material 52, and the liquid crystalline monomer is polymerized to form a polymer network (polymerization step).

The polymerization method of the liquid crystalline monomer can be determined depending on the type of the liquid crystalline monomer and is not particularly limited, and can be performed by, for example, a method of irradiating ultraviolet rays (UV).
The alignment portion 54a constituting the polymer network is aligned together with the liquid crystal molecules 51 by the alignment regulating process applied to the alignment films 1 and 2.

As shown in FIG. 6, the liquid crystal device 100 thus obtained includes, in the liquid crystal 50, fine particles 55 made of a basic oxide and a polymer network obtained by polymerizing a liquid crystalline monomer. Since the adsorbed polymer chain 54c in which the alignment portion 54a is adsorbed is formed on the surface 55a of the fine particle 55 in the liquid crystal 50, the polymer network is adsorbed on the fine particle 55 in the liquid crystal 50.
The adsorbed polymer chain 54c is formed by including the fine particles 55 and the polymer chain 54 in the liquid crystal 50. For example, the number of adsorbed polymer chains 54c can be increased by the following method. .

9 to 11 are schematic diagrams for explaining the relationship between the fine particles in the liquid crystal and the polymer network. Note that in FIG. 9 to FIG. 11, liquid crystal molecules are not shown for easy viewing of the drawings.
FIG. 9 is a schematic view when the liquid crystalline monomer is adsorbed to the fine particles 55 before the dispersion step described above. In this case, polymerization of the liquid crystalline monomer starting from the liquid crystalline monomer preliminarily adsorbed on the fine particles 55 is likely to occur, and the polymer network is likely to be adsorbed to the fine particles 55. Therefore, as compared with the example shown in FIG. Thus, the number of polymer networks adsorbed on the fine particles 55 can be increased. That is, in the example shown in FIG. 9, the number of adsorbed polymer chains 54c is larger than that in the example shown in FIG.

FIG. 10 is a schematic diagram when the polymerization initiator is adsorbed on the fine particles 55 before the dispersion step described above. In this case, as shown in FIG. 10, the polymerization initiator 5 adsorbed on the fine particles 55.
Since the polymerization of the liquid crystalline monomer starting from 7 is likely to occur and the polymer network is easily adsorbed to the fine particles 55, the polymer network adsorbed to the fine particles 55 is compared with the example shown in FIG. The number can be increased. That is, in the example shown in FIG. 10 as well, the number of adsorbed polymer chains 54c increases compared to the example shown in FIG. Further, in the example shown in FIG. 10, the number of polymer chains 54 arranged in the vicinity of the fine particles 55 is increased by the polymerization initiator 57 adsorbed on the fine particles 55 as compared with the example shown in FIG. The dispersion stability of the fine particles 55 in the liquid crystal 50 can be further effectively improved.

As a polymerization initiator used here, benzophenone and its derivative (s), an organic peroxide, etc. can be used, for example.
The amount of the polymerization initiator that is adsorbed on the fine particles 55 before the dispersion step is as follows.
5 to 90% of the surface area of the fine particles 55, depending on the particle size and surface shape of 5
An amount capable of coating the following is preferred. If it is less than this range, the effect of stabilizing the dispersion is not likely to appear.

Further, FIG. 11 is a schematic view when the liquid crystalline monomer and the polymerization initiator are adsorbed to the fine particles 55 before the dispersion step described above. In this case, the polymer network is easily adsorbed by the fine particles 55 due to the synergistic effect of the liquid crystalline monomer previously adsorbed by the fine particles 55 and the polymerization initiator 57, so that the adsorbed by the fine particles 55 compared to the example shown in FIG. The number of polymer networks that are made can be increased. Also in the example shown in FIG. 11, the number of polymer chains 54 arranged in the vicinity of the fine particles 55 is increased by the polymerization initiator 57 adsorbed on the fine particles 55 as compared with the example shown in FIG. In addition, the dispersion stability of the fine particles 55 in the liquid crystal 50 can be further effectively improved.

According to the method for manufacturing a liquid crystal device of the present embodiment, hydrofluoric acid is effectively neutralized and absorbed by the finely dispersed fine particles 55, and excellent durability can be obtained over a long period of time. The liquid crystal device 100 can be manufactured.

[Projection type display device]
Next, a projection display device shown in FIG. 12 will be described as a specific example of the electronic apparatus of the present invention.
FIG. 12 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.

As shown in FIG. 12, the projection type liquid crystal display device includes a light source 810, dichroic mirrors 813 and 814, reflection mirrors 815, 816 and 817, an incident lens 818, a relay lens 819, an exit lens 820, Light modulating means 822 comprising the liquid crystal device of the present invention,
823, 824, a cross dichroic prism 825, and a projection lens 826.

The light source 810 includes a lamp 811 such as a metal halide and a reflector 8 that reflects the light of the lamp.
Twelve. 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. Each of the light modulation means 822
The liquid crystal device of each of the above embodiments is adopted for 823,824.

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 this projection type display device employs the liquid crystal device of each of the above embodiments, good display performance can be obtained over a long period of time even when high intensity light irradiation is performed.

As mentioned above, although embodiment of this invention was described referring drawings, it cannot be overemphasized that this invention is not limited to these examples. That is, the 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, It can be suitably used as an image display means for pagers, electronic notebooks, calculators, word processors, workstations, videophones, POS terminals, devices equipped with touch panels, etc., all of which are highly reliable and have a good display over the long term An electronic device with high performance can be provided.

Next, a liquid crystal device according to the present invention, a method for manufacturing the same, and specific examples in which the liquid crystal device is applied to an electronic device will be described.
[Experimental Example 1]
A high-temperature polysilicon TFT array substrate on which necessary elements other than the alignment film 1 such as electrodes and TFTs are formed, and a counter substrate on which necessary elements other than the alignment film are formed, and the surfaces of the TFT array substrate and the counter substrate are prepared. In addition, an alignment film made of an oblique vapor deposition film mainly composed of silicon oxide (silica) was formed.
Next, the TFT array substrate on which the alignment film is formed and the counter substrate on which the alignment film is formed are
The surfaces on which the alignment films are formed face each other and are bonded together with a sealant at a gap of 3 microns to produce an empty panel. Prepare a plurality of empty panels prepared in this way, fill the empty panel with the liquid crystal (liquid crystal 1) shown below, and irradiate ultraviolet rays (UV) with black light to polymerize the liquid crystalline monomer. By forming a polymer network, a plurality of vertically aligned ECB mode liquid crystal panels were obtained.

(Liquid crystal 1)
Liquid crystal: MX001190 (Merck)
Liquid crystalline monomer: Liquid crystalline monomer shown in FIG. 7A Fine particles: High-purity magnesia with an average particle size of 50 nm (manufactured by Ube Industries)
After the liquid crystalline monomer was adsorbed on the fine particles, the fine particles and the liquid crystalline monomer were dispersed in the liquid crystal and used.
Content (concentration) of liquid crystalline monomer in liquid crystal: 0.5 wt%
Content (concentration) of fine particles in liquid crystal: 0 wt% to 7 wt%

The saturation voltage in the liquid crystal panel thus obtained was examined as follows.
A halogen illumination was used as a light source, a panel was sandwiched between two polarizing plates arranged in crossed Nicols so as to be in a normally black mode, and a measurement system using an illuminometer was prepared as a detector.
Next, the TFT element is driven so that a predetermined potential difference (corresponding to the panel driving voltage) is generated between the upper and lower substrates, and the transmitted illuminance of the panel at the potential difference (corresponding to the panel driving voltage) is measured.
90% of the illuminance when 0V is applied and the illuminance when 6V is applied is 100%.
The potential difference between the upper and lower substrates (corresponding to the panel drive voltage) at an illuminance of 2 was defined as the saturation voltage.
The result is shown in FIG. In FIG. 13A, a saturation voltage of 6 V or more is extrapolated.

FIG. 13A is a graph showing the relationship between the saturation voltage of the liquid crystal panel and the content of fine particles in the liquid crystal. As shown in FIG. 13A, when the content of the fine particles in the liquid crystal exceeds 5 wt%, the saturation voltage of the liquid crystal panel exceeds 6 V, and the drive voltage increases due to the inclusion of the fine particles in the liquid crystal. It became conspicuous, and it was confirmed that driving with TFT elements became difficult.

[Experimental example 2]
The relative durability of the liquid crystal panel obtained in the same manner as in Experimental Example 1 was examined as follows.
The relative durability in this case was expressed as a percentage based on the time until the occurrence of poor photothermal display of a panel having a monomer concentration of 0% and a particle concentration of 0%. Photothermal display failure test is 1
Illuminance of 3000m using 20W UHP lamp light in the wavelength range of 420nm to 500nm
The measurement was performed at W / cm 2 and 60 ° C.
The result is shown in FIG.

FIG. 13B is a graph showing the relationship between the relative durability of the liquid crystal panel and the content of fine particles in the liquid crystal. As shown in FIG. 13B, if the content of the fine particles in the liquid crystal is less than 0.01 wt%, the durability improvement effect due to the inclusion of the fine particles in the liquid crystal may not be sufficiently obtained. It could be confirmed.

[Experimental Example 3]
A plurality of empty panels prepared in the same manner as in Experimental Example 1 were prepared, and the liquid crystal of (Liquid Crystal 2) shown below was filled in the empty panel to obtain a plurality of liquid crystal panels.
(Liquid crystal 2)
Liquid crystal: MX001190 (Merck)
Liquid crystalline monomer: Liquid crystalline monomer shown in FIG. 7A Fine particles: High-purity magnesia with an average particle size of 50 nm (manufactured by Ube Industries)
After the liquid crystalline monomer was adsorbed on the fine particles, the fine particles and the liquid crystalline monomer were dispersed in the liquid crystal and used.
Content (concentration) of liquid crystalline monomer in liquid crystal: 0 wt% to 7 wt%
Content (concentration) of fine particles in liquid crystal: 0.5 wt%

The saturation voltage in the liquid crystal panel thus obtained was examined in the same manner as in Experimental Example 1.
The result is shown in FIG. In FIG. 14, a saturation voltage of 6 V or more is extrapolated.

FIG. 14 is a graph showing the relationship between the saturation voltage of the liquid crystal panel and the content of the liquid crystalline monomer in the liquid crystal. As shown in FIG. 14, when the content of the liquid crystal monomer in the liquid crystal exceeds 5 wt%, the saturation voltage of the liquid crystal panel exceeds 6 V, and the drive voltage increases due to the liquid crystal monomer being contained in the liquid crystal. As a result, it was confirmed that driving with a TFT element becomes difficult.

[Experimental Example 4]
The relative transmittance of the liquid crystal panel obtained in the same manner as in Experimental Example 3 was examined as follows.
Here, the relative transmittance is 10 when the liquid crystal monomer is not contained in the liquid crystal.
It means the transmittance when it is 0%.
A halogen illumination was used as a light source, a panel was sandwiched between two polarizing plates arranged in crossed Nicols so as to be in a normally black mode, and a measurement system using an illuminometer was prepared as a detector.
Next, the transmitted illuminance of the panel when a predetermined 6 V was applied between the upper and lower substrates was measured.
The result is shown in FIG.

FIG. 15 is a graph showing the relationship between the relative transmittance of the liquid crystal panel and the content of the liquid crystalline monomer in the liquid crystal. As shown in FIG. 15, when the content of the liquid crystal monomer in the liquid crystal exceeds 3 wt%, the relative transmittance of the liquid crystal panel becomes less than 90%, and the transmittance due to the liquid crystal monomer being contained in the liquid crystal. It was confirmed that the decrease in the temperature was remarkable.

[Experimental Example 5]
The relative stability of the liquid crystal panel obtained in the same manner as in Experimental Example 3 was examined as follows.
The panel was allowed to stand in a constant temperature layer at 60 ° C. and visually observed, and the time between occurrences of display defects due to aggregation / sedimentation was measured. Here, the time between occurrences of display defects due to aggregation / sedimentation when the monomer concentration was 0% was used as a reference.
The result is shown in FIG.

FIG. 16 is a graph showing the relationship between the relative stability of the liquid crystal panel and the content of the liquid crystalline monomer in the liquid crystal. As shown in FIG. 16, the content of the liquid crystal monomer in the liquid crystal is 0.1 wt%.
It was confirmed that the stability improvement effect due to the inclusion of the liquid crystalline monomer in the liquid crystal could not be sufficiently obtained when the ratio was less than 1.

[Experimental Example 6]
A plurality of empty panels prepared in the same manner as in Experimental Example 1 were prepared, and the liquid crystal of (Liquid Crystal 3 to Liquid Crystal 5) shown below was filled in the empty panel to obtain a plurality of liquid crystal panels.

(Liquid crystal 3)
Liquid crystal: MX001190 (Merck)
Liquid crystalline monomer: Liquid crystalline monomer shown in FIG. 7A Fine particles: High-purity magnesia with an average particle size of 50 nm (manufactured by Ube Industries)
The fine particles and the liquid crystalline monomer were dispersed in the liquid crystal without adsorbing the polymerization initiator and the liquid crystalline monomer on the fine particles.
Content (concentration) of liquid crystalline monomer in liquid crystal: 0.5 wt%
Content (concentration) of fine particles in liquid crystal: 0 wt% to 7 wt%

(Liquid crystal 4)
Liquid crystal: MX001190 (Merck)
Liquid crystalline monomer: Liquid crystalline monomer shown in FIG. 7A Fine particles: High-purity magnesia with an average particle size of 50 nm (manufactured by Ube Industries)
Polymerization initiator: Benzophenone After the polymerization initiator is adsorbed to the fine particles by vacuum deposition, the fine particles, the polymerization initiator, and the liquid crystalline monomer are dispersed in the liquid crystal without adsorbing the liquid crystalline monomer to the fine particles. used.
Content (concentration) of liquid crystalline monomer in liquid crystal: 0.5 wt%
Content (concentration) of fine particles in liquid crystal: 0 wt% to 7 wt%

(Liquid crystal 5)
Liquid crystal: MX001190 (Merck)
Liquid crystalline monomer: Liquid crystalline monomer shown in FIG. 7A Fine particles: High-purity magnesia with an average particle size of 50 nm (manufactured by Ube Industries)
After the polymerization initiator was adsorbed on the fine particles by vacuum vapor deposition, the liquid crystalline monomer was adsorbed on the fine particles by vacuum vapor deposition, and then the fine particles and the polymerization initiator were dispersed in the liquid crystal and used.
Content (concentration) of liquid crystalline monomer in liquid crystal: 0.5 wt%
Content (concentration) of fine particles in liquid crystal: 0 wt% to 7 wt%

And the relative durability in the liquid crystal panel provided with the liquid crystal of (Liquid Crystal 1) (Liquid Crystal 3 to Liquid Crystal 5) was examined in the same manner as in Experimental Example 2. The result is shown in FIG.
FIG. 17 is a graph showing the relationship between the relative durability of the liquid crystal panel and the content of fine particles in the liquid crystal. As shown in FIG. 17, it can be seen that (Liquid Crystal 1), (Liquid Crystal 4) and (Liquid Crystal 5) are superior in relative durability as compared with (Liquid Crystal 3) in which no liquid crystalline monomer is adsorbed to the fine particles. In addition, relative durability is superior to the liquid crystal monomer adsorbed with the liquid crystal monomer (liquid crystal 1) than the liquid crystal monomer adsorbed with the polymerization initiator (liquid crystal 4). It was confirmed that the liquid adsorbed with the polymerizable monomer and the polymerization initiator (liquid crystal 5) was more excellent.

FIG. 1 is a plan view of the liquid crystal device 100 as viewed from the counter substrate side together with the components. FIG. 2 is a cross-sectional view of the liquid crystal device 100 taken along line H-H ′ shown in FIG. 1. FIG. 3 is a diagram illustrating an equivalent circuit 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 100. FIG. 4 is an enlarged view showing a cross-sectional structure of the liquid crystal device 100. FIG. 5 is a schematic diagram for explaining a polymer network in the liquid crystal constituting the liquid crystal display device of the present embodiment. FIG. 6 is a schematic diagram for explaining the relationship between the fine particles in the liquid crystal and the polymer network constituting the liquid crystal display device of the present embodiment. FIG. 7 is a diagram for explaining an alignment portion and a binding portion of a polymer chain. FIG. 8 is a diagram for explaining an alignment portion and a binding portion of a polymer chain. FIG. 9 is a schematic view when the liquid crystalline monomer is adsorbed to the fine particles 55 before the dispersion step described above. FIG. 10 is a schematic view when the polymerization initiator is adsorbed on the fine particles 55 before the dispersion step described above. FIG. 11 is a schematic view when the liquid crystalline monomer and the polymerization initiator are adsorbed on the fine particles before the dispersion step. FIG. 12 is a schematic configuration diagram showing a main part of the projection display device. FIG. 13 is a graph showing the relationship between the saturation voltage or relative durability of the liquid crystal panel and the content of fine particles in the liquid crystal. FIG. 14 is a graph showing the relationship between the saturation voltage of the liquid crystal panel and the content of the liquid crystalline monomer in the liquid crystal. FIG. 15 is a graph showing the relationship between the relative transmittance of the liquid crystal panel and the content of the liquid crystalline monomer in the liquid crystal. FIG. 16 is a graph showing the relationship between the relative stability of the liquid crystal panel and the content of the liquid crystalline monomer in the liquid crystal. FIG. 17 is a graph showing the relationship between the relative durability of the liquid crystal panel and the content of fine particles in the liquid crystal.

Explanation of symbols

1, 2 ... Alignment film, 10 ... TFT array substrate, 20 ... Counter substrate, 52 ... Sealing material, 50 ...
Liquid crystal, 51 ... liquid crystal molecule, 54 ... polymer chain, 54a ... orientation part, 54b ... bonding part, 54c
... adsorption polymer chain, 55 ... fine particles, 57 ... polymerization initiator, 100 ... liquid crystal device.

Claims (9)

A liquid crystal device having a liquid crystal sandwiched between a pair of substrates,
The liquid crystal device, wherein the liquid crystal includes fine particles made of a basic oxide and a polymer network obtained by polymerizing a liquid crystalline monomer. The liquid crystal device according to claim 1, wherein the polymer network is adsorbed on the fine particles. The liquid crystal device according to claim 1, wherein the fine particles are contained in the liquid crystal in an amount of 0.01 wt% to 5 wt%. 4. The liquid crystal device according to claim 1, wherein the polymer network is contained in the liquid crystal in an amount of 0.1 wt% to 5 wt%. 5. The alignment film according to claim 1, wherein an alignment film mainly comprising silicon oxide and controlling alignment of the liquid crystal is provided on the liquid crystal side surface of at least one of the pair of substrates. The liquid crystal device according to any one of the above. A method of manufacturing a liquid crystal device in which a liquid crystal is sandwiched between a pair of substrates,
A dispersion step of dispersing fine particles comprising a basic oxide and a liquid crystalline monomer in the liquid crystal;
And a polymerization step of forming a polymer network by polymerizing the liquid crystalline monomer. The method for manufacturing a liquid crystal device according to claim 6, wherein the liquid crystalline monomer is adsorbed to the fine particles before the dispersion step. The polymerization initiator is adsorbed on the fine particles before the dispersing step.
A method for manufacturing a liquid crystal device according to claim 7. An electronic apparatus comprising the liquid crystal device according to claim 1.

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