JP2020160313A - Liquid crystal display element and method for manufacturing the same - Google Patents

Abstract

To provide a PSA mode liquid crystal display element that suppresses burning of an image, can maintain good display quality and has a fast response speed, and a method for manufacturing the element.SOLUTION: A liquid crystal display element described below and a method for manufacturing the element are provided. The liquid crystal display element has: a liquid crystal layer comprising a polymer of one or more polymerizable compounds and a liquid crystal composition; a first electrode substrate having a first substrate and a first electrode layer disposed on the liquid crystal layer side of the first substrate; a second electrode substrate opposing to the first electrode substrate via the liquid crystal layer, and having a second substrate and a second electrode layer disposed on the liquid crystal layer side of the second substrate; and a first alignment film disposed between the first electrode substrate and the liquid crystal layer. The liquid crystal composition comprises one or more alkenyl-based liquid crystal compounds. The first alignment film has a predetermined absorptivity or higher for light at a wavelength of 365 nm.SELECTED DRAWING: Figure 1

Description

The present invention relates to a PSA mode liquid crystal display element and a method for manufacturing the same, and more particularly to a technique for reducing deterioration of display quality due to light irradiation during PSA processing.

Conventionally, as a liquid crystal display element, various driving methods have been developed in which the electrode structure and the physical properties of the liquid crystal molecules used are different. For example, the MVA (Multi-Domain Vertical Alignment) type panel conventionally known as the vertical orientation mode aims to expand the viewing angle by regulating the collapse direction of the liquid crystal molecules by the protrusions formed in the liquid crystal panel. .. However, according to this method, it is inevitable that the transmittance and contrast derived from the protrusions are lowered, and the response speed of the liquid crystal molecules tends to be slow.

In order to solve these problems of the MVA type panel, a PSA (Polymer Unified Alignment) mode has been put into practical use as a new drive mode for controlling the orientation of liquid crystal molecules. In the PSA mode, a photopolymerizable monomer (polymerizable compound) is mixed in a liquid crystal material, the liquid crystal cell is assembled, and then the liquid crystal cell is irradiated with light while a voltage is applied between a pair of electrodes sandwiching the liquid crystal layer. This is a technique for controlling the molecular orientation of liquid crystal molecules by polymerizing a photopolymerizable monomer. According to this technology, there are advantages that the viewing angle can be expanded and high-speed response can be achieved. Further, in recent years, further high-speed response of PSA type liquid crystal panels has been studied, and as such a technique, a liquid crystal compound having an alkenyl group or an alkenyloxy group (hereinafter, also referred to as "alkenyl liquid crystal compound") is used as a liquid crystal. Attempts have been made to introduce it into layers (see, for example, Patent Documents 1 to 3).

JP-A-2010-285499 Japanese Unexamined Patent Publication No. 9-104644 Japanese Unexamined Patent Publication No. 6-108053

The PSA mode liquid crystal display element can expand the viewing angle and achieve a high-speed response, but on the other hand, it requires a large amount of ultraviolet irradiation for the polymerization reaction of the polymerizable compound during manufacturing, and the panel is caused by the ultraviolet irradiation. There is a problem that the display quality of is deteriorated. Above all, the above problem remarkably appears in a PSA liquid crystal display element using a liquid crystal layer containing an alkenyl liquid crystal compound. More specifically, the alkenyl liquid crystal compound can increase the response speed of the liquid crystal display element in the PSA mode, but the alkenyl group contained in the alkenyl liquid crystal compound due to the light emitted in the manufacturing process of the liquid crystal display element. And alkenyloxy groups react with each other, and decomposition and deterioration are likely to occur. Therefore, there is a problem that the effect of increasing the response speed due to the inclusion of the alkenyl liquid crystal compound is impaired, the voltage retention rate is lowered, and image burn-in (afterimage) is likely to occur. On the other hand, if the amount of light irradiation is reduced in order to suppress the decomposition and deterioration of the alkenyl liquid crystal compound, the polymerization reaction of the polymerizable compound does not proceed sufficiently, and a large amount of unreacted polymerizable compound remains in the liquid crystal layer. .. In this case as well, there is a problem that image burn-in (afterimage) is likely to occur due to the unreacted polymerizable compound.

The present invention has been made in view of the above problems, and is a PSA mode liquid crystal display element having a liquid crystal layer containing an alkenyl liquid crystal compound, in which image burn-in is suppressed and good display quality can be maintained. A main object of the present invention is to provide a PSA mode liquid crystal display element having a high response speed and a method for manufacturing the same.

As a result of diligent studies to solve the above problems, the present inventors have found that the alignment film used for orienting liquid crystal molecules has light absorption characteristics, particularly light in the wavelength range of 365 nm or less including ultraviolet light (poles). It was found that the light absorption characteristics of the alignment film with respect to light in the short wavelength region) are remarkable. Therefore, they have found that the above problems can be solved by using an alignment film having a high ability to absorb light in an extremely short wavelength region, and have completed the present invention. Specifically, the present invention provides the following PSA mode liquid crystal display element and a method for manufacturing the same.

That is, one embodiment of the present invention is provided on a liquid crystal layer containing a polymer of one or more polymerizable compounds and a liquid crystal composition, and on the surface of the first substrate and the first substrate on the liquid crystal layer side. The first electrode substrate having the first electrode layer and the second electrode substrate facing the first electrode substrate via the liquid crystal layer, and provided on the surface of the second substrate and the second substrate on the liquid crystal layer side. It has a second electrode substrate having an electrode layer and a first alignment film arranged between the first electrode substrate and the liquid crystal layer, and the liquid crystal composition is one kind or two or more kinds of alkenyl-based. The first alignment film containing a liquid crystal compound provides a liquid crystal display element in which the absorption rate of light having a wavelength of 365 nm is a predetermined value or more.

Further, in one embodiment of the present invention, a first electrode substrate having a first electrode layer provided on one surface of the first substrate and the first substrate, and one surface of the second substrate and the second substrate. A second electrode substrate having a second electrode layer provided in the above is prepared, and the absorption rate of light having a wavelength of 365 nm is equal to or higher than a predetermined value on the surface of the first electrode substrate on the side of the first electrode layer. The first alignment film arranging step of providing the first alignment film, the surface of the first electrode substrate having the first alignment film, and the surface of the second electrode substrate provided with the second electrode layer are opposed to each other. A polymerizable liquid crystal composition containing one or more polymerizable compounds and a liquid crystal composition containing one or more alkenyl liquid crystal compounds between the first electrode substrate and the second electrode substrate. A liquid crystal cell forming step of arranging objects to form a liquid crystal cell, and irradiating the polymerizable liquid crystal composition with light from the first electrode substrate side of the liquid crystal cell to form a polymer of the polymerizable compound and the above. Provided is a method for manufacturing a liquid crystal display element, which comprises a light irradiation step of forming a liquid crystal layer containing a liquid crystal composition.

According to one embodiment of the present invention, it is possible to provide a PSA mode liquid crystal display element having a fast response speed, which can suppress image burn-in and maintain good display quality.

Further, according to one embodiment of the present invention, by irradiating the polymerizable liquid crystal composition with light through an alignment film having a high ability to absorb light in an extremely short wavelength region, the polymerization reaction of the polymerizable compound can be sufficiently carried out. Since it is possible to prevent the decomposition and deterioration of the alkenyl liquid crystal compound as it progresses, it is possible to manufacture a PSA mode liquid crystal display element having a fast response speed, which can suppress image seizure and maintain good display quality. ..

It is schematic cross-sectional view which shows an example of the liquid crystal display element which is one Embodiment of this invention. It is a schematic diagram which shows an example of the electrode pattern of the electrode layer which the liquid crystal display element which is one Embodiment of this invention has. 6 is a graph of light absorption spectra of the alignment films PI-1 to PI-6 used in Examples and Comparative Examples alone.

I. Liquid crystal display element FIG. 1 is a schematic cross-sectional view showing an example of a liquid crystal display element according to an embodiment of the present invention (hereinafter, referred to as a liquid crystal display element of the present embodiment), and is a PSA mode liquid crystal display element. .. As shown in FIG. 1, the liquid crystal display element 10 of the present embodiment includes a liquid crystal layer 13 containing a polymer of one or more polymerizable compounds and a liquid crystal composition, and a first substrate 12 and a first substrate 12. The first electrode substrate 2 having the first electrode layer 15 provided on the surface on the liquid crystal layer 13 side of the above, facing the first electrode substrate 2 via the liquid crystal layer 13, and the second substrate 11 and the second substrate 11 It has a second electrode substrate 1 having a second electrode layer 14 provided on the surface on the liquid crystal layer 13 side, and a first alignment film 17 arranged between the first electrode substrate 2 and the liquid crystal layer 13. The liquid crystal composition contains one or more alkenyl liquid crystal compounds. Further, the first alignment film 17 has a light absorption rate of a wavelength of 365 nm or more of a predetermined value or more.

In the liquid crystal display element illustrated in FIG. 1, the first electrode 15 included in the first electrode substrate 2 functions as a pixel electrode layer. On the other hand, the second electrode substrate 1 has a color filter 18 between the second substrate 11 and the second electrode layer 14, and the second electrode layer 14 functions as a common electrode layer. The liquid crystal display element illustrated in FIG. 1 further has a second alignment film 16 arranged between the second electrode substrate 1 and the liquid crystal layer 13.

The liquid crystal layer 13 contains a polymer of a liquid crystal composition and a polymerizable compound. The liquid crystal composition contains a plurality of types of liquid crystal compounds (liquid crystal molecules) 19, but the liquid crystal composition in the present embodiment essentially contains one or more alkenyl liquid crystal compounds. The PSA mode liquid crystal display element can adjust the pre-tilt direction and pre-tilt angle of the liquid crystal molecules (liquid crystal compounds) constituting the liquid crystal composition by controlling the electric field and the like formed in the liquid crystal layer. Further, regions 21 and 20 of the polymer of the polymerizable compound are formed at the interface between the liquid crystal layer 13 and the first alignment film 17 and the second alignment film 16, respectively.

A color filter 18 is provided on the second electrode substrate 2. In the liquid crystal display element of the present embodiment, the color filter is preferably arranged on the second electrode substrate side.

According to the liquid crystal display element of the present embodiment, since the first alignment film having a light absorption rate in the extremely short wavelength region of a predetermined value or more is arranged, the alkenyl liquid crystal is irradiated with light in the manufacturing process of the liquid crystal display element. It is possible to have a liquid crystal layer in which deterioration of the compound is suppressed and the residual amount of the polymerizable compound is reduced. As a result, the liquid crystal display element of the present embodiment can maintain good display quality in which image burn-in is suppressed, and can have high response speed.

In the present specification, the "extremely short wavelength region" refers to light in a wavelength region of 365 nm or less, and more specifically, light in a wavelength region of 300 nm or more and 365 nm or less. The light in the wavelength range of 365 nm or less includes ultraviolet light. Further, the light in the extremely short wavelength region preferably includes light having a peak in the vicinity of 313 nm.

Hereinafter, each configuration of the liquid crystal display element of the present embodiment will be described.

A. First Alignment Film The first alignment film in the present embodiment is a member that is arranged between the first substrate and the liquid crystal layer and has a light absorption rate of 365 nm or more of a predetermined value. The first alignment film has a function of orienting the liquid crystal compound contained in the liquid crystal layer. The liquid crystal compound is a compound constituting the liquid crystal composition, and may be referred to as a liquid crystal material.

When the absorption rate of light having a wavelength of 365 nm is equal to or higher than a predetermined value, the absorption rate of light having a wavelength of 365 nm is 2.0% or more, preferably 2.1% or more, 2.5% or more, and 3.0%. Above, 3.2% or more, 4.0% or more, 5.0% or more, 5.5% or more, 5.8% or more. The higher the absorption rate of light having a wavelength of 365 nm, the better, but it is preferably 50% or less, 30% or less, 20% or less, 10% or less, and 6% or less. If the absorption rate of light having a wavelength of 365 nm is too high, a large amount of unreacted polymerizable compound may remain in the liquid crystal layer.

The first alignment film in the present embodiment preferably has a light absorption rate of a wavelength of 313 nm or more of a predetermined value or more. When the absorption rate of light having a wavelength of 365 nm and the absorption rate of light having a wavelength of 313 nm are each set to a predetermined value or more, it is possible to more effectively suppress the decomposition deterioration and seizure of the alkenyl liquid crystal compound due to light irradiation. Is. When the absorption rate of light having a wavelength of 313 nm is equal to or higher than a predetermined value, the absorption rate of light having a wavelength of 313 nm is preferably 15% or more, more preferably 16% or more, 17% or more, 20% or more, and 23%. These are 25% or more and 27% or more. The higher the absorption rate of light having a wavelength of 313 nm, the better, but it is preferably 80% or less, 60% or less, 40% or less, and 30% or less. If the absorption rate of light having a wavelength of 313 nm is too high, a large amount of unreacted polymerizable compound may remain in the liquid crystal layer.

The light absorption rate of the first alignment film can be determined by the following measuring method. First, the transmittance of the electrode substrate on which the alignment film is formed (referred to as the electrode substrate with the alignment film) is measured using a spectrophotometer. As the spectrophotometer used, for example, V-670 manufactured by JASCO Corporation can be used. The conditions for measuring the transmittance are as follows. Select% T (transmittance measurement mode) as the photometric mode, set the response fast, bandwidth 2.0 nm, scanning speed 400 nm / min, start wavelength 500 nm, end wavelength 300 nm, data capture interval 1.0 nm, and transmittance. An electrode substrate with an alignment film is placed on the measurement holder, and the transmittance is measured. Next, the absolute reflectance of the electrode substrate with the same alignment film is measured. As the measuring machine, for example, V-670 of JASCO Corporation can be used as the same spectrophotometer as the transmittance measurement. The conditions for measuring the reflectance are as follows. For the metering mode, select% R (reflectance measurement mode), set the response fast, bandwidth 2.0 nm, scanning speed 400 nm / min, start wavelength 500 nm, end wavelength 300 nm, data capture interval 1.0 nm, and absolute reflection. An electrode substrate with an alignment film is placed in the rate measurement holder, and the absolute reflectance is measured. From the measurement results of the transmittance and the absolute reflectance of the electrode substrate with the alignment film, the light absorption rate of the electrode substrate with the alignment film in which the alignment film and the substrate are combined can be obtained by the following formula (A).

Absorption rate (alignment film + electrode substrate)% = 100%-[Transmittance (alignment film + electrode substrate)%]-[Absolute reflectance (alignment film + electrode substrate)%] ... (A)

Next, the alignment film is removed from the electrode substrate with the alignment film. As a method of removal, a method using chemical etching or a method of physically sputtering and sublimating the alignment film can be used. In order to remove the alignment film in the measurement area (for example, 10 mm × 10 mm) of the spectrophotometer without affecting the underlying electrode substrate, for example, a sputtering method using argon gas is suitable. .. The transmittance and absolute reflectance of the electrode substrate alone from which the alignment film was removed were measured by the same method as the method for measuring the transmittance and absolute reflectance of the electrode substrate with the alignment film, and the transmittance and absolute reflectance of the obtained electrode substrate alone and Based on the absolute reflectance, the absorption rate of the electrode substrate alone can be obtained by the following formula (B).

Absorption rate (electrode substrate)% = 100%-[Transmittance (electrode substrate)%]-[Absolute reflectance (electrode substrate)%] ... (B)

Therefore, the absorption rate of the alignment film alone can be obtained by the following formula (C).

Absorption rate (alignment film)% = [absorption rate (alignment film + electrode substrate)%]-[absorption rate (electrode substrate)%] ... (C)

Of course, by measuring the light absorption rate of the electrode substrate alone before forming the alignment film and then measuring the light absorption rate of the electrode substrate with the alignment film after forming the alignment film on the electrode substrate, the light of the alignment film alone is measured. The absorption rate may be calculated.

The light absorption rate of the alignment film having a wavelength of 365 nm is the difference between the light absorption rate of the electrode substrate with the alignment film having a wavelength of 365 nm and the light absorption rate of the electrode substrate alone having a wavelength of 365 nm measured by the above method. The value. The light absorption rate of the alignment film having a wavelength of 313 nm is the difference between the light absorption rate of the electrode substrate with the alignment film having a wavelength of 313 nm and the light absorption rate of the electrode substrate alone having a wavelength of 313 nm, which is measured by the above method. Is the value of.

The light absorption rate of the alignment film can be adjusted by, for example, the film thickness of the alignment film, the composition of the alignment film, and the like.

It is estimated that the light absorption rate of the alignment film increases as the film thickness increases even if the alignment film material is the same. However, if an attempt is made to increase the light absorption rate by increasing the film thickness of the alignment film, there is a problem that it takes time to volatilize the solvent component in the preheating in the production of the liquid crystal display element. Further, if the film thickness of the alignment film is small, it is difficult to obtain a desired light absorption rate, and there is a problem that a sufficient alignment regulating force cannot be obtained. Therefore, it is necessary to specify the optimum film thickness of the first alignment film so that the absorption rate of the specific wavelength light in the extremely short wavelength region becomes a predetermined value or more. Specifically, the film thickness of the first alignment film is preferably 0.001 μm or more, 0.005 μm or more, preferably 0.01 μm or more, and preferably 0.05 μm or more. The film thickness is preferably 1 μm or less, preferably 0.5 μm or less, preferably 0.3 μm or less, and preferably 0.15 μm or less. More specifically, the film thickness of the first alignment film is preferably 0.01 μm to 0.3 μm, and more preferably 0.05 μm to 0.15 μm.

The material constituting the first alignment film can be the same as that of a known alignment film, and examples thereof include polyimide, polyamide, polysiloxane, and a mixture thereof. Of these, polyimide is preferable. The polyimide may be a photocrosslinked polyimide or a split-complex polyimide.

The first alignment film may be subjected to a rubbing treatment or the like.

The method for forming the first alignment film will be described in the section "II. Method for manufacturing a liquid crystal display element" described later, and thus the description thereof will be omitted here.

B. Liquid crystal layer The liquid crystal layer in the present embodiment is a layer arranged between the first electrode substrate and the second electrode substrate. More specifically, the liquid crystal layer is sandwiched between the first alignment film formed on the surface of the first electrode substrate on the side of the first electrode layer and the surface of the second electrode substrate on the side of the second electrode layer. One surface of the layer is in direct contact with the first alignment film. When the second alignment layer is formed on the surface of the second electrode substrate on the side of the second electrode layer, the other surface of the liquid crystal layer is in direct contact with the second alignment layer.

The liquid crystal layer in the present embodiment contains a polymer of one or more polymerizable compounds and a liquid crystal composition. In the PSA mode liquid crystal display element, the polymer of the polymerizable compound can exist in a layered state at the interface between the liquid crystal layer and the alignment film, for example. Such a liquid crystal layer is obtained by irradiating a polymerizable liquid crystal composition containing one or more kinds of polymerizable compounds and a liquid crystal composition containing one or more kinds of liquid crystal compounds with light to obtain the above-mentioned polymerizable properties. It can be formed by polymerizing a compound. Hereinafter, each component contained in the liquid crystal layer and the polymerizable liquid crystal composition for forming the liquid crystal layer, and other components optionally blended will be described.

1. 1. Liquid crystal composition The liquid crystal composition preferably shows a negative value of dielectric anisotropy. Here, the dielectric anisotropy of the liquid crystal composition means the dielectric anisotropy (Δε) of the liquid crystal composition at 20 ° C. Among them, the liquid crystal composition is preferably a nematic liquid crystal composition in which the dielectric anisotropy shows a negative value.

The liquid crystal composition may contain one or more compounds having a negative dielectric anisotropy. A compound having a negative dielectric anisotropy is a compound having a negative sign of Δε at 20 ° C. and having an absolute value greater than 2. The compound having a negative dielectric anisotropy is not particularly limited, and is, for example, in the general formulas (N-01), (N-02), (N-03), (N-03) and (N-05). Examples thereof include compounds selected from the represented compound group.

(In the above general formulas (N-01) to (N-05), R ²¹ and R ²² are independently an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, and carbon. Represents an alkenyl group having 2 to 8 atoms and an alkenyloxy group having 2 to 8 carbon atoms, and Z ¹ is independently single-bonded, -CH ₂ CH _2- , -OCH _2- or -CH ₂ O. -Represents-and m independently represents 1 or 2)

In the above formulas (N-01) to (N-05), Z ¹ is preferably a single bond, −CH ₂ CH ₂ − or − CH ₂ O−, respectively. Above all, when m is 1, Z ¹ is preferably a single bond, and when m is 2, Z ¹ is preferably −CH ₂ CH _2- or −CH ₂ O−.

The liquid crystal composition is a compound represented by the general formula (N-01), which is a general formula (N-01-1), a general formula (N-01-2), a general formula (N-01-3) and a general formula. It is preferable to contain one or more compounds selected from the compound group represented by the formula (N-01-4).

(In (N-01-4) from the above general formula (N-01-1), R ²¹ and R ²³ are independently alkyl groups having 1 to 8 carbon atoms and 1 to 8 carbon atoms, respectively. Represents an alkoxy group, an alkenyl group having 2 to 8 carbon atoms, and an alkenyloxy group having 2 to 8 carbon atoms.)

It is particularly preferable that the liquid crystal composition contains a compound represented by the general formula (N-01-1).

It is particularly preferable that the liquid crystal composition contains a compound represented by the general formula (N-01-4).

The liquid crystal composition is a compound represented by the general formula (N-02), which is represented by the general formula (N-02-1), the general formula (N-02-2), and the general formula (N-02-3). It is preferable to contain one or more compounds selected from the represented compound group.

(In the above general formula (N-02-1) to (N-02-3), R ²¹ and R ²³ are independently alkyl groups having 1 to 8 carbon atoms and 1 to 8 carbon atoms, respectively. Represents an alkoxy group, an alkenyl group having 2 to 8 carbon atoms, and an alkenyloxy group having 2 to 8 carbon atoms.)

It is particularly preferable that the liquid crystal composition contains a compound represented by the general formula (N-02-1).

The liquid crystal composition preferably contains one or more compounds represented by the general formula (N-03-1) as the compound represented by the general formula (N-03).

(In the above general formula (N-03-1), R ²¹ and R ²³ independently have an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, and 2 to 2 carbon atoms. Represents an alkenyl group of 8 and an alkenyloxy group having 2 to 8 carbon atoms.)

The liquid crystal composition preferably contains a compound represented by the general formula (N-03-1) and a compound represented by the general formula (N-02-1).

The liquid crystal composition comprises a compound represented by the general formula (N-03-1), a compound represented by the general formula (N-01-4), and a compound represented by the general formula (N-02-1). It is preferable to contain it.

The liquid crystal composition preferably contains one or more compounds represented by the general formula (N-04-1) as the compound represented by the general formula (N-04).

(In the above general formula (N-04-1), R ²¹ and R ²³ independently have an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, and 2 to 2 carbon atoms. Represents an alkenyl group of 8 and an alkenyloxy group having 2 to 8 carbon atoms.)

The lower limit of the preferable content of the compound represented by the general formula (N-01) with respect to the total amount of the liquid crystal composition is 0% by mass, 1% by mass, 5% by mass, and 10% by mass. %, 20% by mass, 30% by mass, 40% by mass, 50% by mass, 55% by mass, 60% by mass, 65% by mass, 70% by mass. Yes, it is 75% by mass, and it is 80% by mass. The upper limit of the preferable content is 95% by mass, 85% by mass, 75% by mass, 65% by mass, 55% by mass, 45% by mass, and 35% by mass. Yes, 25% by mass, 20% by mass, 15% by mass, and 10% by mass.

The lower limit of the preferable content of the compound represented by the general formula (N-02) with respect to the total amount of the liquid crystal composition is 0% by mass, 1% by mass, 5% by mass, and 10% by mass. %, 20% by mass, 30% by mass, 40% by mass, 50% by mass, 55% by mass, 60% by mass, 65% by mass, 70% by mass. Yes, it is 75% by mass, and it is 80% by mass. The upper limit of the preferable content is 95% by mass, 85% by mass, 75% by mass, 65% by mass, 55% by mass, 45% by mass, and 35% by mass. Yes, 25% by mass, 20% by mass, 15% by mass, and 10%.

The lower limit of the preferable content of the compound represented by the general formula (N-03) with respect to the total amount of the liquid crystal composition is 0% by mass, 1% by mass, 5% by mass, and 10% by mass. %, 20% by mass, 30% by mass, 40% by mass, 50% by mass, 55% by mass, 60% by mass, 65% by mass, 70% by mass. Yes, it is 75% by mass, and it is 80% by mass. The upper limit of the preferable content is 95% by mass, 85% by mass, 75% by mass, 65% by mass, 55% by mass, 45% by mass, and 35% by mass. Yes, 25% by mass, 20% by mass, 15% by mass, and 10% by mass.

The lower limit of the preferable content of the compound represented by the general formula (N-04) with respect to the total amount of the liquid crystal composition is 0% by mass, 1% by mass, 5% by mass, and 10% by mass. %, 20% by mass, 30% by mass, 40% by mass, 50% by mass, 55% by mass, 60% by mass, 65% by mass, 70% by mass. Yes, it is 75% by mass, and it is 80% by mass. The upper limit of the preferable content is 95% by mass, 85% by mass, 75% by mass, 65% by mass, 55% by mass, 45% by mass, and 35% by mass. Yes, 25% by mass, 20% by mass, 15% by mass, and 10% by mass.

The lower limit of the preferable content of the compound represented by the general formula (N-05) with respect to the total amount of the liquid crystal composition is 0% by mass, 2% by mass, 5% by mass, and 8% by mass. %, 10% by mass, 13% by mass, 15% by mass, 17% by mass, and 20% by mass. The upper limit of the preferable content is 30% by mass, 28% by mass, 25% by mass, 23% by mass, 20% by mass, 18% by mass, and 15% by mass. Yes, it is 13% by mass.

The liquid crystal composition may further contain one or more kinds of dielectrically neutral compounds. The "dielectrically neutral compound" means a compound having Δε of -2 or more and +2 or less at 20 ° C. Examples of the dielectrically neutral compound include compounds selected from the compound group represented by the general formula (NU-01) to the general formula (NU-08).

(From the above general formula (NU-01) to (NU-08), R ^NU11 , R ^NU12 , R ^NU21 , R ^NU22 , R ^NU31 , R ^NU32 , R ^NU41 , R ^NU42 , R ^NU51 , R ^NU52 , R ^NU61 . R ^NU62 , R ^NU71 , R ^NU72 , R ^NU81 and R ^NU82 independently have an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, and an alkenyl group having 2 to 8 carbon atoms. Alternatively, it represents an alkenyloxy group having 2 to 8 carbon atoms.)

When the liquid crystal composition contains a compound represented by the general formula (NU-01), the content of the compound represented by the general formula (NU-01) with respect to the total amount of the liquid crystal composition is 1% by mass or more and 60% by mass. It is preferably 10% by mass or more and 50% by mass or less, more preferably 20% by mass or more and 40% by mass or less.

When the liquid crystal composition contains a compound represented by the general formula (NU-02), the content of the compound represented by the general formula (NU-02) with respect to the total amount of the liquid crystal composition is 1% by mass or more and 40% by mass. It is preferably 5% by mass or more, more preferably 25% by mass or less, and further preferably 5% by mass or more and 20% by mass or less.

When the liquid crystal composition contains a compound represented by the general formula (NU-03), the content of the compound represented by the general formula (NU-03) with respect to the total amount of the liquid crystal composition is 1% by mass or more and 20% by mass. It is preferably 1% by mass or more and 15% by mass or less, more preferably 1% by mass or more and 10% by mass or less.

When the liquid crystal composition contains a compound represented by the general formula (NU-04), the content of the compound represented by the general formula (NU-04) with respect to the total amount of the liquid crystal composition is 1% by mass or more and 30% by mass. It is preferably 3% by mass or more and 20% by mass or less, and further preferably 3% by mass or more and 10% by mass or less.

When the liquid crystal composition contains a compound represented by the general formula (NU-05), the content of the compound represented by the general formula (NU-05) with respect to the total amount of the liquid crystal composition is 1% by mass or more and 30% by mass. It is preferably 1% by mass or more and 20% by mass or less, and further preferably 3% by mass or more and 20% by mass or less.

When the liquid crystal composition contains a compound represented by the general formula (NU-06), the content of the compound represented by the general formula (NU-06) with respect to the total amount of the liquid crystal composition is 1% by mass or more and 30% by mass. It is preferably 3% by mass or more and 20% by mass or less, and further preferably 3% by mass or more and 10% by mass or less.

When the liquid crystal composition contains a compound represented by the general formula (NU-07), the content of the compound represented by the general formula (NU-07) with respect to the total amount of the liquid crystal composition is 1% by mass or more and 30% by mass. It is preferably 3% by mass or more and 20% by mass or less, and further preferably 3% by mass or more and 10% by mass or less.

When the liquid crystal composition contains a compound represented by the general formula (NU-08), the content of the compound represented by the general formula (NU-08) with respect to the total amount of the liquid crystal composition is 1% by mass or more and 30% by mass. It is preferably 3% by mass or more and 20% by mass or less, and further preferably 3% by mass or more and 10% by mass or less.

In the present embodiment, the liquid crystal composition contains one or more alkenyl liquid crystal compounds. Here, the alkenyl-based liquid crystal compound in the present embodiment is a group consisting of an alkenyl group which may be substituted by one or more halogen atoms and an alkenyloxy group which may be substituted by one or more halogen atoms. A liquid crystal compound having at least one group selected from the above. Among them, the alkenyl group which may be substituted by one or more halogen atoms and the alkenyloxy group which may be substituted by one or more halogen atoms are used when the improvement of the response speed of the liquid crystal composition is important. A structure having CH ₂ = CH-group at the terminal is preferable. However, since the structure is highly reactive with light in the extremely short wavelength region, the liquid crystal composition containing the compound has a problem that the reliability is lowered.

Here, "substituted by one or more halogen atoms" means that one or more hydrogen atoms of the alkenyl group and the alkenyloxy group can be replaced by the halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and among them, a fluorine atom is preferable.

Examples of the alkenyl liquid crystal compound include compounds represented by the following general formula (i).

(In the above general formula (i), ^Ri1 may be substituted with one or more halogen atoms, or may be substituted with an alkenyl group having 2 to 8 carbon atoms or one or more halogen atoms. Represents an alkenyloxy group with 2 to 8 atoms
R ⁱ² represents an alkyl group having 1 to 8 carbon atoms, and one or two or more non-adjacent −CH ₂ −s in the alkyl group are independently −CH = CH− and −C≡C−. , -O-, -CO-, -COO- or -OCO- may be substituted.
Z ⁱ¹ represents a single bond or linking group
A ⁱ¹ and A ⁱ² are independent of each other (a) 1,4-cyclohexylene group (one −CH ₂ − present in this group or two or more non-adjacent −CH ₂₋ is −O. (May be replaced with −) and (b) 1,4-phenylene group (one -CH = existing in this group or two or more -CH = not adjacent to each other is replaced with -N =. May be done.)
Representing a group selected from the group consisting of, the above groups (a) and (b) are independently substituted with a cyano group, a fluorine atom, a chlorine atom, a methyl group, a trifluoromethyl group or a trifluoromethoxy group, respectively. May be
^mi1 represents 1-3. )

Examples of the linking group represented by Z ⁱ¹ include -CH ₂ CH _2- , -OCH _2- , -CH ₂ O-, -COO-, -OCO-, -OCF _2- , -CF ₂ O-, -CH. = CH-, -CF = CF- or -C≡C-. Z ⁱ¹ is preferably single bond, −CH ₂ CH ₂ −, −OCH ₂ −, or −CH ₂ O−.

Among the compounds represented by the general formula (i), the alkenyl group and the alkenyloxy group are preferably linear groups having 2 to 5 carbon atoms, and the formulas (R1) to (R5) are used. The group represented by any of the above is preferable, and the group represented by the formula (R1) or the formula (R2) is more preferable, and when the improvement of the response speed is emphasized, the formula (R1) is used. Is preferable.

(The black dots in each formula represent carbon atoms in the ring structure of general formula (i).)

The alkenyl liquid crystal compound may be a compound having a negative dielectric anisotropy (smaller than -2), or may be a dielectrically neutral (-2≤Δε≤2) compound. When the liquid crystal composition contains two or more kinds of alkenyl liquid crystal compounds, it may contain only one of the alkenyl liquid crystal compound having a negative dielectric anisotropy and the dielectrically neutral alkenyl liquid crystal compound. Both may be included.

Examples of the alkenyl-based liquid crystal compound having a negative dielectric constant anisotropy represented by the general formula (i) include the above-mentioned general formulas (N-01), (N-02), (N-03), and (N). -04) and (N-05) are selected from the compound group, and at least one of R ²¹ and R ^{22 in} the above general formulas (N-01) to (N-05) is carbon. Examples thereof include compounds representing an alkenyl group having 2 to 8 atoms or an alkenyloxy group having 2 to 8 carbon atoms.

Among them, in the alkenyl liquid crystal compound having a negative dielectric anisotropy represented by the general formula (i), the alkenyl group is a group represented by any of the formulas (R1) to (R5). It is preferable, and more preferably, it is a group represented by the formula (R1) or the formula (R2).

(The black dots in each formula represent carbon atoms in the ring structure of the general formulas (N-01) to (N-05).)

The dielectrically neutral alkenyl-based liquid crystal compound represented by the general formula (i) is selected from, for example, from the compound group represented by the general formula (NU-01) to the above-mentioned general formula (NU-01). It is a compound, the general formula (NU-01) compound at least one of ^{R NU11} and ^{R NU12} is an alkenyl group or an alkenyloxy group having 2 to 8 carbon atoms of 2 to 8 carbon atoms in the above A compound in which at least one of R ^NU21 and R ^{NU22 in} the general formula (NU-02) represents an alkenyl group having 2 to 8 carbon atoms or an alkenyloxy group having 2 to 8 carbon atoms, the above general formula (NU-03). compounds at least one of ^{R NU31} and ^{R NU32} is an alkenyl group or an alkenyloxy group having 2 to 8 carbon atoms of 2 to 8 carbon atoms in, ^R in the general formula (NU-04) ^NU41 and ^{R NU42} At least one of the compounds representing an alkenyl group having 2 to 8 carbon atoms or an alkenyloxy group having 2 to 8 carbon atoms, and at least one of R ^NU51 and R ^{NU52 in} the above general formula (NU-05) has carbon atoms. A compound representing an alkenyl group of 2 to 8 or an alkenyloxy group having 2 to 8 carbon atoms, at least one of R ^NU61 and R ^{NU62 in} the above general formula (NU-06) is an alkenyl group having 2 to 8 carbon atoms or A compound representing an alkenyloxy group having 2 to 8 carbon atoms, at least one of R ^NU71 and R ^{NU72 in} the above general formula (NU-07) has an alkenyl group having 2 to 8 carbon atoms or an alkenyl group having 2 to 8 carbon atoms. A compound representing an alkenyloxy group, a compound in which at least one of R ^NU81 and R ^{NU82 in} the above general formula (NU-08) represents an alkenyl group having 2 to 8 carbon atoms or an alkenyloxy group having 2 to 8 carbon atoms. Can be mentioned.

In the dielectrically neutral alkenyl liquid crystal compound represented by the general formula (i), the alkenyl group and the alkenyloxy group are preferably linear groups having 2 to 5 carbon atoms. The group represented by any of the formulas (R1) to (R5) is preferable, and the group represented by the formula (R1) or the formula (R2) is more preferable, and the improvement of the response speed is emphasized. The formula (R1) is more preferable.

(The black dots in each formula represent carbon atoms in the ring structure of the general formulas (NU-01) to (NU-08).)

Specific examples of the dielectrically neutral alkenyl liquid crystal compound represented by the general formula (i) are, for example, the following formulas (L-1-1.1) to (L-1-1.3). Compounds selected from the group of compounds represented, compounds selected from the group of compounds represented by the formulas (L-1-2.1) to (L-1-2.4), formulas (L-1--4.). Compounds selected from the compound group represented by the formulas (L-1-5.3) from 1), compounds represented by the formulas (L-1-6.3) from the formulas (L-1-6.1) Examples include compounds selected from the group. Among them, a compound selected from the compound group represented by the formulas (L-1-1.1) to (L-1-1.3) is preferable from the viewpoint of exhibiting high-speed response.

The preferable content of the alkenyl liquid crystal compound in the liquid crystal composition is 1% by mass or more, 5% by mass or more, 15% by mass or more, 25% by mass or more, and 35% by mass or more. The content is preferably 80% by mass or less, more preferably 70% by mass or less, 60% by mass or less, and 50% by mass or less. When two or more kinds of alkenyl liquid crystal compounds are contained, it is preferable that the total amount thereof is within the above-mentioned content range.

The liquid crystal composition may contain one or more antioxidants. The type of antioxidant is not particularly limited, but a hindered phenolic antioxidant is particularly preferable. As the hindered phenolic antioxidant, a compound selected from the group consisting of compounds represented by the general formulas (H-1) to (H-4) can be preferably used.

(In the general formulas (H1) (H-4) , R H1 each independently represent an alkyl group having a carbon number of 3 to ^{7, M H1} is an alkylene group having 4 to 10 carbon atoms (One or more -CH _2- in the alkylene group may be substituted with -COO- or -OCO- so that oxygen atoms are not directly adjacent to each other.), Single bond, 1, It represents a 4-phenylene group (any hydrogen atom in the 1,4-phenylene group may be substituted with a fluorine atom) or a trans-1,4-cyclohexylene group.)

More specifically, R ^H1 of the general formula (H1) is preferably an alkyl group having a carbon number of 7. ^{R H1} of the general formula (H-2) is preferably an alkyl group having a carbon number of 3. ^{R H1} of the general formula (H-3) is preferably an alkyl group having a carbon number of 3. Further, in the general formula ^{(H-4), M H1 is, M H1} is preferably an alkylene group having 4-8 carbon atoms.

The lower limit of the content of the antioxidant contained in the liquid crystal composition is preferably 10 mass ppm, preferably 20 mass ppm, and preferably 50 mass ppm. The upper limit of the content is preferably 10000 mass ppm, preferably 1000 mass ppm, preferably 500 mass ppm, and preferably 100 mass ppm.

In addition to the above-mentioned compounds, the liquid crystal composition may contain any material such as ordinary nematic liquid crystal, smectic liquid crystal, cholesteric liquid crystal, ultraviolet absorber, infrared absorber and the like.

The liquid crystal composition includes one or more compounds selected from the group consisting of the compounds represented by the general formulas (N-01) to (N-05), and the general formulas (NU-01) to (NU-). It may contain at least one kind or two or more kinds of compounds selected from the group consisting of the compounds represented by 08). The total content of the compounds represented by the general formulas (N-01) to (N-05) and the compounds represented by the general formulas (NU-01) to (NU-08) with respect to the total amount of the liquid crystal composition is preferable. The lower limit is 80% by mass, 85% by mass, 88% by mass, 90% by mass, 92% by mass, 93% by mass, 94% by mass, and 95% by mass. Yes, it is 96% by mass, it is 97% by mass, it is 98% by mass, it is 99% by mass, and it is 100% by mass. The preferred upper limit of the total content is 100% by mass, 99% by mass, 98% by mass, and 95% by mass.

The liquid crystal composition preferably has a nematic phase-isotropic liquid phase transition temperature ( _TNI ) of 60 ° C. or higher and 120 ° C. or lower, more preferably 70 ° C. or higher and 100 ° C. or lower, and particularly 70 ° C. or higher and 85 ° C. or lower. preferable. In this specification, 60 ° C. or higher is expressed as having a high _TNI . For LCD TV applications, T _NI is preferably 70 ° C or higher and 80 ° C or lower, for mobile applications, T _NI is preferably 80 ° C or higher and 90 ° C or lower, and for outdoor display applications such as PID (Public Information Display), T _{The NI} is preferably 90 ° C. or higher and 110 ° C. or lower.

The liquid crystal composition preferably has a refractive index anisotropy (Δn) at 20 ° C. of 0.08 or more and 0.14 or less, more preferably 0.09 or more and 0.13 or less, and 0.09 or more and 0.12. The following is more preferable, and 0.098 or more and 0.118 or less is particularly preferable. More specifically, when dealing with a thin cell gap, the refractive index anisotropy (Δn) at 20 ° C. is preferably 0.10 or more and 0.13, while when dealing with a thick cell gap, it is preferable. The refractive index anisotropy (Δn) at 20 ° C. is preferably 0.08 or more and 0.10 or less.

The liquid crystal composition preferably has a rotational viscosity (γ ₁ ) at 20 ° C. of 50 Pa · s or more and 160 mPa · s or less, preferably 55 Pa · s or more and 160 mPa · s or less, and 60 Pa · s or more and 160 mPa · s. It is preferably 80 Pa · s or more and 150 mPa · s or less, 90 Pa · s or more and 140 mPa · s or less, 90 Pa · s or more and 130 mPa · s or less, and 90 Pa · s or less. -It is preferably s or more and 115 mPa · s or less.

The liquid crystal composition preferably has a dielectric anisotropy (Δε) at 20 ° C. of -1.7 or more and -4.0 or less, more preferably -2.5 or more and -3.8 or less, and -2. 6 or more and -3.7 or less are more preferable, and -2.7 or more and -3.6 or less are particularly preferable.

2. 2. Polymerizable Compound Examples of the polymerizable compound existing as a polymer in the liquid crystal layer include compounds selected from the group consisting of compounds represented by the following general formula (RM) or general formula (RM-13).

(In the general formula ^{(RM), R 101, R} 102, R 103, R 104, R 105, R 106, R 107 and ^{R 108} are each ^{independently,} P 13 ^{-S 13} -, substituted by fluorine atoms Represents an alkyl group having 1 to 18 carbon atoms which may be used, an alkoxy group having 1 to 18 carbon atoms which may be substituted by a fluorine atom, a fluorine atom or a hydrogen atom, and P ¹¹ , P ¹² and P. ¹³ are independently from Eqs. (Re-1) to Eqs. (Re-9).

(Wherein the formula (Re-1) (Re- 9), R 11, R 12, R 13, R 14 and ^{R 15} are each independently an alkyl group having 1 to 5 carbon atoms, a fluorine atom or Representing any of the hydrogen atoms, m ^r5 , m ^r7 , n ^r5 and n ^r7 independently represent 0, 1, or 2, but ^mr5 , ^mr7 , n ^r5 and / or n ^r7 When it represents 0, it represents a single bond.)
In represents represented by polymerizable ^groups, S ^{11, S 12} and ^{S 13} are each independently a single bond or an alkylene group having 1 to 15 carbon atoms, one -CH 2 in the alkylene radical ₂ - or nonadjacent two or more _-CH 2 - is -O -, - it may be substituted OCO- or ^-COO-, in ^the case ^{of P 13} and ^{S 13} there are a plurality, respectively, the same It may be different. )

(In the above general formula (RM-13), P ³ and P ⁴ are independently described in formulas (PG-1) to formulas (PG-5).

Represents a polymerizable group represented by, S ³ represents a single bond or an alkylene group having 1 to 5 carbon atoms, and Y ¹ to Y ¹² independently represent fluorine or hydrogen atoms, but at least one. Represents a fluorine atom. )

The content of the polymerizable compound in the polymerizable liquid crystal composition is preferably adjusted in the range of 0.1% by mass or more and 0.6% by mass or less.

C. 1st Electrode Substrate and 2nd Electrode Substrate The 1st electrode substrate in the present embodiment has a 1st electrode substrate and a 1st electrode layer provided on the surface of the 1st substrate on the liquid crystal layer side. Further, the second electrode substrate has a second electrode layer and a second electrode layer provided on the surface of the second substrate on the liquid crystal layer side. The first electrode substrate and the second electrode substrate face each other via the liquid crystal layer.

1. 1. First Substrate and Second Substrate The first substrate and the second substrate (hereinafter, may be generally referred to as substrates) may be flexible substrates or rigid substrates. As such a substrate, for example, a transparent substrate such as a glass plate or a plastic plate can be used. Examples of the glass constituting the glass plate include soda glass and non-alkali glass. Examples of the resin constituting the plastic substrate include acrylic resin, methacrylic resin, polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, polycarbonate, and cyclic polyolefin resin. Further, in the present embodiment, since the alignment film having a high light absorption ability in the extremely short wavelength region is arranged on the first substrate side, at least the first substrate is translucent in the first substrate and the second substrate. The second substrate may or may not have translucency. The non-transmissive substrate can be made of an opaque material such as a metal material or a silicon material.

2. 2. First Electrode Layer and Second Electrode Layer One of the first electrode layer and the second electrode layer functions as a common electrode layer, and the other functions as a pixel electrode layer. Usually, of the first electrode substrate and the second electrode substrate, the electrode layer of the electrode substrate provided with the color filter functions as a common electrode layer. In the present embodiment, the color filter is provided on the second electrode substrate, the first electrode layer of the first electrode substrate is the pixel electrode layer, and the second electrode layer of the second electrode substrate is the common electrode layer. Is preferable.

The common electrode layer is made of a transparent material such as indium-added tin oxide (ITO). In addition to ITO, it may be composed of oxide semiconductors such as zinc oxide (ZnO), tin oxide (SnO ₂ ), InGaZnO, SiGe, GaAs, IZO (Indium Zinc Oxide), TIO, and AZTO (AlZnSnO). The shape of the common electrode layer can be selected according to the drive method of the liquid crystal display element.

The pixel electrode layer is usually composed of a transparent material such as indium-added tin oxide (ITO). In addition to ITO, it may be composed of oxide semiconductors such as zinc oxide (ZnO), tin oxide (SnO ₂ ), InGaZnO, SiGe, GaAs, IZO (Indium Zinc Oxide), TIO, and AZTO (AlZnSnO). The pixel electrode layers are arranged in a matrix on the substrate. The pixel electrode layer is controlled by a drain electrode of an active element represented by a TFT switching element, and the TFT switching element has a gate line which is an address signal line and a source line which is a data line in a matrix.

When pixel division is performed to divide the tilting direction of the liquid crystal molecules in the pixel into several regions in order to improve the viewing angle characteristics, a slit (electrode formation) having a striped or V-shaped pattern in each pixel is performed. A pixel electrode layer having a portion that is not formed) may be provided.

Above all, the electrode layer preferably has a pattern shape divided into a plurality of regions. FIG. 2 is a schematic plan view showing a typical form of a slit electrode (comb electrode) when the inside of a pixel is divided into four regions. Since this slit electrode has a comb-shaped slit in four directions from the center of the pixel, the liquid crystal molecules in each pixel that are substantially vertically oriented with respect to the substrate when no voltage is applied are subjected to the application of the voltage. The director of the liquid crystal molecule is pointed in four different directions to approach the horizontal orientation. That is, by applying different voltages in each of the four regions, the direction of the pretilt angle of the liquid crystal molecules can be changed for each region. As a result, the orientation direction of the liquid crystal in the pixel can be divided into a plurality of directions, so that an extremely wide viewing angle characteristic can be obtained.

As a method for dividing pixels, in addition to a method of providing a slit in a pixel electrode, a method of providing a structure such as a linear protrusion in a pixel, a method of providing an electrode other than a pixel electrode or a common electrode, and the like are used. Although the orientation direction of the liquid crystal molecules can be divided by these methods, a configuration using a slit electrode is preferable from the viewpoint of transmittance and ease of manufacture. Since the pixel electrode provided with the slit does not have a driving force with respect to the liquid crystal molecules when no voltage is applied, it is not possible to impart a pretilt angle to the liquid crystal molecules. However, since the liquid crystal display element of the present embodiment has an alignment film, a pretilt angle can be imparted, and a wide viewing angle due to pixel division can be achieved by combining with the pixel-divided slit electrode.

It should be noted that having a pre-tilt angle means that the director of the liquid crystal molecules is slightly different from the direction perpendicular to the substrate surface (the surface adjacent to the liquid crystal layer in the first electrode substrate and the second electrode substrate) in the state where no voltage is applied. Say the state of being.

D. Second Alignment Film The liquid crystal display element of the present embodiment may have a first alignment film arranged between the first electrode substrate and the liquid crystal layer, but is arranged between the second electrode substrate and the liquid crystal layer. It may further have a second alignment film formed. That is, the liquid crystal layer may be sandwiched between the first alignment film and the second alignment film.

The second alignment film may be the same as the first alignment film, and the film thickness, material, and light absorption rate in the extremely short wavelength region may be different from those of the first alignment film.

Above all, it is preferable that the second electrode substrate has a second alignment film. Further, the second alignment film preferably has the same absorption rate of light at a wavelength of 365 nm as that of the first alignment film, and both the absorption rate of light at a wavelength of 365 nm and the absorption rate of light at a wavelength of 313 nm are the first alignment film. It is more preferable that it is the same as. In the manufacture of the liquid crystal display element, even if the light is irradiated from the second electrode substrate side, the light in the extremely short wavelength region can be absorbed by the second alignment film, so that the effect of the present embodiment can be more remarkable. Because it can be done.

E. Other Constituent Parts The liquid crystal display element of the present embodiment may have a constituent part known in the PSA mode liquid crystal display element in addition to the above-mentioned constituent parts. Examples of other constituent parts include a color filter, a polarizing plate, and the like. The color filter is preferably provided on the second electrode substrate side from the viewpoint that the optical function of the first alignment film in the manufacturing process of the liquid crystal display element can be sufficiently exhibited. Examples of the polarizing plate include a polarizing plate in which a polarizing film called "H film" in which polyvinyl alcohol is stretch-oriented and iodine is absorbed is sandwiched between cellulose acetate protective films, and a polarizing plate composed of the H film itself. be able to.

F. Others The liquid crystal display element of this embodiment is in PSA mode. The PSA mode liquid crystal display element can be effectively applied to various devices, for example, a clock, a portable game, a word processor, a notebook computer, a car navigation system, a camcorder, a PDA, a digital camera, a mobile phone, a smartphone, and various types. It can be used for various display devices such as monitors, LCD TVs, and information displays.

The liquid crystal display element of the present embodiment can be manufactured by the method described in the section "II. Manufacturing method of liquid crystal display device".

II. Manufacturing Method of Liquid Crystal Display Element The manufacturing method of the liquid crystal display element according to the embodiment of the present invention (hereinafter referred to as the manufacturing method of the present embodiment) is provided on one surface of the first substrate and the first substrate. A first electrode substrate having a first electrode layer and a second electrode substrate having a second electrode layer provided on one surface of the second substrate and the second substrate are prepared, and the first electrode substrate is prepared. A first alignment film forming step of providing a first alignment film having a light absorption rate of 365 nm or more of a predetermined value on the surface of the first electrode layer side, and the first alignment film of the first electrode substrate. The surface of the second electrode substrate and the surface of the second electrode substrate provided with the second electrode layer are opposed to each other, and one or more types of polymerization are performed between the first electrode substrate and the second electrode substrate facing each other. A liquid crystal cell forming step of arranging a polymerizable liquid crystal composition containing a sex compound and a liquid crystal composition containing one or more alkenyl liquid crystal compounds to form a liquid crystal cell, and the first of the above liquid crystal cells. It includes a light irradiation step of irradiating the polymerizable liquid crystal composition with light from the electrode substrate side to form a polymer of the polymerizable compound and a liquid crystal layer containing the liquid crystal composition.

According to the method for manufacturing a liquid crystal display element of the present embodiment, a liquid crystal layer is formed by irradiating a polymerizable liquid crystal composition with light through an alignment film having a light absorption rate of a wavelength of 365 nm or more of a predetermined value or more. Therefore, it is possible to obtain a PSA mode liquid crystal display element having a fast response speed in which deterioration of display quality due to burn-in is suppressed. More specifically, among the light irradiated to the polymerizable liquid crystal composition, the light in the wavelength range required for the polymerization reaction of the polymerizable compound passes through the alignment film and reaches the polymerizable liquid crystal composition. Thereby, the polymerizable compound contained in the polymerizable liquid crystal composition can be sufficiently polymerized, and a liquid crystal layer having a low content of unreacted polymerizable compound can be formed. Further, since the light in the extremely short wavelength region that causes the deterioration of the alkenyl liquid crystal compound is absorbed by the alignment film and does not reach the polymerizable liquid crystal composition, the deterioration of the alkenyl liquid crystal compound can be suppressed. Due to these effects, a liquid crystal display element having a high response speed can be obtained in which deterioration of display quality due to burn-in is suppressed.

Here, as a method of preventing the polymerizable liquid crystal composition from being irradiated with light in the extremely short wavelength region during the manufacture of the liquid crystal display element, for example, light in the extremely short wavelength region is provided between the light source and the liquid crystal cell. A method of irradiating light through a cutting filter (UV cut filter) is also envisioned. However, usually, the filter is arranged near the light source, and there is a distance before the light transmitted through the filter reaches the liquid crystal cell. Therefore, in the case of the above method, a part of the light that has passed through the filter and the extremely short wavelength region is cut does not enter the liquid crystal cell, and the polymerizable compound is polymerized with respect to the polymerizable liquid crystal composition in the liquid crystal cell. If the amount of light required for the above is not sufficiently irradiated, the residual amount of the unreacted polymerizable compound may increase. On the other hand, according to the production method of the present embodiment, the light in the extremely short wavelength region is absorbed by the first alignment film in the liquid crystal cell, and the light transmitted through the first alignment film directly irradiates the polymerizable liquid crystal composition. Therefore, it is presumed that the decrease in the amount of light irradiation to the polymerizable compound can be suppressed and the residual amount of the unreacted polymerizable compound can be reduced.

Hereinafter, the method for manufacturing the liquid crystal display element of the present embodiment will be described for each process.

A. First Alignment Film Arrangement Step The first alignment film arrangement process includes a first electrode substrate having a first electrode layer provided on one surface of the first substrate and the first substrate, a second substrate, and the second alignment film. A second electrode substrate having a second electrode layer provided on one surface of the substrate is prepared, and an absorption rate of light having a wavelength of 365 nm is determined on the surface of the first electrode substrate on the first electrode layer side. This is a step of providing the first alignment film having a value equal to or higher than the value.

The first electrode substrate and the second electrode substrate can be formed by a known method in a liquid crystal display element. The substrate and the electrode layer in the electrode substrate and other members constituting the electrode substrate can be the same as those described in the section “I. Liquid crystal display element”.

Further, of the pair of electrode substrates constituting the liquid crystal display element, one electrode substrate is usually provided with a color filter, but in the present embodiment, it is preferable that the second electrode substrate is provided with a color filter. When a color filter is provided on the first electrode substrate, the color filter inhibits light transmission when irradiating light from the side of the first electrode substrate provided with the first alignment film in the light irradiation step described later. This is because there is a possibility that a sufficient amount of light cannot be applied to the polymerizable liquid crystal composition. The method of providing the color filter can be the same as the known method.

The first alignment film arranged on the first electrode substrate in this step has an absorption rate of light having a wavelength of 365 nm or more. When the absorption rate of light having a wavelength of 365 nm is equal to or higher than a predetermined value, the absorption rate of light having a wavelength of 365 nm is 2.0% or more, preferably 2.1% or more, 2.5% or more, and 3.0%. Above, 3.2% or more, 4.0% or more, 5.0% or more, 5.5% or more, 5.8% or more. The higher the absorption rate of light having a wavelength of 365 nm, the better, but it is preferably 50% or less, 30% or less, 20% or less, 10% or less, and 6% or less. If the absorption rate of light having a wavelength of 365 nm is too high, a large amount of unreacted polymerizable compound may remain in the light irradiation step.

Further, the first alignment film preferably has a light absorption rate of a wavelength of 313 nm or more of a predetermined value or more. When the absorption rate of light having a wavelength of 313 nm is equal to or higher than a predetermined value, the absorption rate of light having a wavelength of 313 nm is preferably 15% or more, more preferably 16% or more, 17% or more, 20% or more, and 23%. These are 25% or more and 27% or more. The higher the absorption rate of light having a wavelength of 313 nm, the better, but it is preferably 80% or less, 60% or less, 40% or less, and 30% or less. If the absorption rate of light having a wavelength of 313 nm is too high, a large amount of unreacted polymerizable compound may remain in the light irradiation step.

In this step, by using a first alignment film having a light absorption rate of at least a wavelength of 365 nm of a predetermined value or more, a pole that causes decomposition and deterioration of the alkenyl liquid crystal compound in the light irradiated in the light irradiation step. It can absorb light in the short wavelength range with high efficiency. Further, by using a first alignment film in which the absorption rate of light having a wavelength of 313 nm is equal to or higher than a predetermined value in addition to the absorption rate of light having a wavelength of 365 nm, light in an extremely short wavelength range is absorbed over a wider range with a high absorption rate. It is possible to further suppress the decomposition and deterioration of the alkenyl liquid crystal compound.

The light absorption rate of the first alignment film used in this step can be measured by the method described in the above section "I. Liquid crystal display element".

As the first alignment film, a separately formed alignment film may be attached to the surface of the first electrode substrate on the side of the first electrode layer, and a liquid crystal alignment agent may be applied onto the first electrode layer of the first electrode substrate. It may be applied and the coating film may be heated to form. The liquid crystal alignment agent contains a polyamic acid, a polyamic acid ester, an imidized polymer having an imide ring structure and an amic acid structure, and the like, and is appropriately prepared according to the material of the target alignment film. For example, in the case of forming a polyimide alignment film, a mixture of tetracarboxylic dianhydride and diisocyanate, a polyamic acid, a polyimide solution in which polyimide is dissolved or dispersed in a solvent, or the like can be used as the liquid crystal alignment agent. On the other hand, in the case of forming a polysiloxane-based alignment film, the liquid crystal alignment agent is a poly produced by mixing a silicon compound having an alkoxy group, an alcohol derivative and a oxalic acid derivative in a predetermined blending amount ratio and heating. A polysiloxane solution in which siloxane is dissolved can be used.

The solid content concentration in the liquid crystal alignment agent (the ratio of the total weight of the components other than the solvent of the liquid crystal alignment agent to the total weight of the liquid crystal alignment agent) is appropriately selected in consideration of viscosity, volatility, etc., but is preferable. It is in the range of 1 to 10% by weight. When the liquid crystal alignment agent is applied to the surface of the first electrode substrate on the first electrode layer side and preferably heated to form a liquid crystal alignment film, if the solid content concentration is less than 1% by weight, the film thickness Is too small to obtain a good alignment film. On the other hand, when the solid content concentration exceeds 10% by weight, the film thickness becomes excessive and it is difficult to obtain a good alignment film, and the viscosity of the liquid crystal alignment agent increases and the coating characteristics become inferior.

As a method of applying the liquid crystal alignment agent on the first electrode layer of the first electrode substrate, an offset printing method, a spin coating method, a roll coater method or an inkjet printing method can be preferably performed. When applying the liquid crystal alignment agent, a functional silane compound is applied to the surface of the first electrode substrate and the surface of the first electrode substrate on the side of the first electrode layer in order to further improve the adhesiveness between the first electrode layer and the alignment film. , A pretreatment for applying a functional titanium compound or the like in advance may be performed.

After the liquid crystal alignment agent is applied to the substrate, preheating is preferably performed for the purpose of preventing the applied liquid crystal alignment agent from dripping. The prebake temperature is preferably 30 ° C. to 200 ° C., more preferably 40 ° C. to 150 ° C., and particularly preferably 40 ° C. to 100 ° C. The pre-baking time is preferably 0.25 minutes to 10 minutes, more preferably 0.5 minutes to 5 minutes. After that, a firing (post-baking) step is carried out for the purpose of completely removing the solvent and, if necessary, thermally imidizing the amic acid structure present in the polymer. The post-bake temperature is preferably 80 ° C. to 300 ° C., more preferably 120 ° C. to 250 ° C. The post-baking time is preferably 5 to 200 minutes, more preferably 10 to 100 minutes.

The film thickness of the coating film of the liquid crystal aligning agent may be such that the absorption rate of light having a wavelength of at least 365 nm is at least a predetermined value, and the film thickness of the obtained alignment film is preferably 0.01 μm to 0.3 μm. The film thickness of the coating film can be designed so as to be within the range, more preferably within the range of 0.05 μm to 0.15 μm.

After applying the liquid crystal alignment agent, the alignment film is formed by removing the organic solvent by heating. At this time, if the polymer contained in the liquid crystal aligning agent is a polyamic acid, a polyamic acid ester, or an imidized polymer having an imide ring structure and an amic acid structure, the coating film is coated. The dehydration ring closure reaction may be allowed to proceed by further heating after the formation to further imidize.

The coating film (alignment film) of the liquid crystal alignment agent may be subjected to the following liquid crystal cell forming step as it is, or may be subjected to the liquid crystal cell forming step after the surface is subjected to a rubbing treatment, if necessary. The rubbing treatment can be performed by rubbing the coated surface of the liquid crystal alignment agent in a certain direction with a roll wrapped with a cloth made of fibers such as nylon, rayon, and cotton.

B. Liquid crystal cell forming step In the liquid crystal cell forming step, the surface of the first electrode substrate having the first alignment film and the surface of the second electrode substrate provided with the second electrode layer face each other and face each other. A polymerizable liquid crystal composition containing one or more polymerizable compounds and a liquid crystal composition containing one or two or more alkenyl liquid crystal compounds is arranged between the one electrode substrate and the second electrode substrate. Then, it is a step of forming a liquid crystal cell.

The polymerizable liquid crystal composition used in this step includes one or more kinds of polymerizable compounds and a liquid crystal composition containing one kind or two or more kinds of alkenyl liquid crystal compounds. Since the polymerizable compound and the liquid crystal composition have been described in the above section "I. Liquid crystal display element", the description thereof is omitted here.

For example, the following two methods can be mentioned for manufacturing a liquid crystal cell. The first method is a conventionally known method (vacuum injection method). First, the first electrode substrate and the surface of the second electrode substrate provided with the second electrode layer face each other through a gap (cell gap) so that the surface of the first electrode substrate having the first alignment film and the surface of the second electrode substrate provided with the second electrode layer face each other. The second electrode substrate (hereinafter, may be referred to as two electrode substrates) is arranged so as to face each other, and the peripheral portions of the two electrode substrates are bonded together using a sealant, and the surface of the two electrode substrates and the sealant are used. This is a method for producing a liquid crystal cell by injecting and filling the polymerizable liquid crystal composition into the cell gap partitioned by the above, and then sealing the injection hole. On the other hand, the second method is a method called the ODF (One Drop Fill) method. In this method, for example, an ultraviolet photocurable sealant is applied to a predetermined place on the first electrode substrate, and a polymerizable liquid crystal composition is dropped onto a predetermined number of places on the alignment film surface, and then the first step is performed. The second electrode substrate is bonded so that the surface of the one electrode substrate having the first alignment film and the surface of the second electrode substrate provided with the second electrode layer face each other, and two polymerizable liquid crystal compositions are applied. This is a method of manufacturing a liquid crystal cell by spreading the entire surface of the electrode substrate of No. 1 and then irradiating the entire surface of the two electrode substrates with ultraviolet light to cure the sealant. When the second electrode substrate has the second alignment film, the sealant may be applied to the second electrode substrate, the polymerizable liquid crystal composition may be dropped, and then the first electrode substrate may be bonded.

Regardless of which method is used, the liquid crystal cell produced as described above is further heated to a temperature at which the liquid crystal compound contained in the polymerizable liquid crystal composition used is isotropic, and then slowly cooled to room temperature. Therefore, the flow orientation at the time of filling the liquid crystal may be removed.

As the sealing agent that seals between the first electrode substrate and the second electrode substrate that face each other, for example, an epoxy resin containing glass fiber having a controlled diameter can be used as a curing agent and a spacer.

C. Light irradiation step In the light irradiation step, the polymerizable liquid crystal composition is irradiated with light from the first electrode substrate side of the liquid crystal cell to form a liquid crystal layer containing the polymer of the polymerizable compound and the liquid crystal composition. This is the process of

The number of times of irradiation with light in this step may be as long as it is possible to impart a desired pretilt angle to the liquid crystal molecules and to completely polymerize the polymerizable compound in the polymerizable liquid crystal composition. Well, it may be more than once. Among them, the first light irradiation treatment of irradiating the polymerizable liquid crystal composition with light from the first electrode substrate side of the liquid crystal cell in a state where a voltage is applied between the first electrode substrate and the second electrode substrate. After the first light irradiation treatment, the polymerizable liquid crystal composition is formed from the first electrode substrate side of the liquid crystal cell in a state where no voltage is applied between the first electrode substrate and the second electrode substrate. It is preferable to have a second light irradiation treatment for irradiating light. This is because the pretilt angle can be imparted to the liquid crystal molecules by the first light irradiation treatment, and the polymerizable compound can be polymerized by the second light irradiation treatment.

The voltage applied in the first light irradiation treatment can be, for example, a direct current or an alternating current of 5V to 50V.

As the light to be irradiated in the first light irradiation treatment, for example, ultraviolet rays containing light having a wavelength of 150 nm to 800 nm and visible light can be used, and among them, ultraviolet rays containing light having a wavelength of 300 nm to 400 nm are preferable. As the light source of the irradiation light, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an excimer laser, an LED and the like can be used.

The intensity of the light irradiated in the first light irradiation process, for example, at an intensity of 365 nm, it is possible to use light in the range of ^{1mW / cm 2 ~1000mW / cm 2} , the range of 50mW / ^{cm 2} ~150mW / ^cm 2 It is preferable to use light of the intensity of. The irradiation time is in the range of 1 to 1000 seconds, with integrated light quantity terms the light intensity is the product of the irradiation time is preferably in the range of ^{5J / cm 2 ~15J / cm 2} . Therefore, the irradiation time is preferably in the range of 30 seconds to 300 seconds.

Next, the second light irradiation treatment is performed after the first light irradiation treatment. In the second light irradiation treatment, unlike the first light irradiation treatment, light irradiation is performed from the first electrode substrate side of the liquid crystal cell without applying a voltage between the two electrode substrates.

In the first light irradiation treatment and the second light irradiation treatment, it is important to completely polymerize the polymerizable compound in the polymerizable liquid crystal composition. This is because if any unpolymerized polymerizable compound remains, the voltage retention rate decreases, and as a result, the liquid crystal display element is seized. Therefore, the intensity of the light irradiated in the second light irradiation treatment is preferably smaller than the intensity of the light in the first light irradiation treatment. More specifically, it is preferable that the intensity of the light having a wavelength of 365 nm irradiated in the second light irradiation treatment is smaller than the intensity of the light having a wavelength of 365 nm irradiated in the first light irradiation treatment. This is because the polymerizable compound contained in the polymerizable liquid crystal composition can be efficiently polymerized by irradiating with light having a relatively low intensity for a certain period of time as compared with the first light irradiation treatment.

In the second light irradiation treatment, for example 365nm at can be used a light intensity of ^{0.1mW / cm 2 ~100mW / cm 2} , the use of inter alia the intensity of 1mW / ^{cm 2} ~10mW / ^cm 2 light Is preferable. It is preferred irradiation time is in the range of 100 seconds to 10,000 seconds, with integrated light quantity terms the intensity of light and is the product of the irradiation time is preferably in the range of ^{5J / cm 2 ~15J / cm 2} . Therefore, the irradiation time is preferably 500 seconds to 15,000 seconds.

In the second light irradiation treatment, it is preferable to irradiate light containing a larger amount of ultraviolet rays having a shorter wavelength than the light irradiated in the first light irradiation treatment. Specifically, it is preferable to irradiate light containing more light having a wavelength of 313 nm than the light irradiated in the first light irradiation treatment. The fact that a large amount of light having a wavelength of 313 nm is contained means that the relative intensity of light having a wavelength of 313 nm is large with respect to light having a wavelength of 365 nm. Therefore, the light containing more light having a wavelength of 313 nm than the light irradiated by the first light irradiation treatment is more than the relative intensity of the light having a wavelength of 313 nm with respect to the light having a wavelength of 365 nm. It means that the relative intensity of the light having a wavelength of 313 nm is larger than that of the light having a wavelength of 365 nm in the light irradiated by the second light irradiation treatment. In other words, in the second light irradiation treatment, it is preferable to irradiate light having a peak on the shorter wavelength side than the light irradiated in the first light irradiation treatment. This is because in the second light irradiation treatment, the polymerizable compound can be sufficiently polymerized by irradiating light containing more light in a shorter wavelength region than the light irradiated in the first light irradiation treatment.

The light source used in the second light irradiation treatment may be the same as or different from that in the first light irradiation treatment. Examples of the light source other than the above-mentioned light source include a fluorescent lamp. Above all, the light source used in the second light irradiation treatment is preferably a fluorescent lamp. Light in the extremely short wavelength range (ultraviolet light) contained in the fluorescent lamp accelerates the decomposition of the alkenyl liquid crystal compound contained in the liquid crystal composition, and as a result, the voltage retention rate decreases and the liquid crystal display element is seized. It is presumed that it will wake up. On the other hand, according to the method for manufacturing a liquid crystal display element of the present embodiment, even if the fluorescent lamp is irradiated from the first electrode substrate side of the liquid crystal cell, the light from the fluorescent lamp is light in an extremely short wavelength region. Since the polymerizable liquid crystal composition is reached after the ultraviolet light is sufficiently absorbed by the first alignment film, the decomposition and deterioration of the alkenyl liquid crystal compound due to light irradiation can be sufficiently suppressed. As described above, by using the fluorescent lamp as the light source, the effect of the manufacturing method of the present embodiment can be more remarkablely exhibited.

By this step, the polymerizable compound in the polymerizable liquid crystal composition is polymerized, and a liquid crystal layer containing the polymer of the polymerizable compound and the liquid crystal composition is formed. Since the liquid crystal layer has been described in the section "I. Liquid crystal display element", the description thereof will be omitted.

D. Other Steps In the manufacturing method of the present embodiment, a second alignment film is provided on the surface of the second electrode substrate on the second electrode layer side between the first alignment film placement step and the liquid crystal cell forming step. It may include a placement step. The method of providing the second alignment film can be the same as the method of providing the first alignment film described above.

Further, in the manufacturing method of the present embodiment, after the light irradiation step, the surface of the liquid crystal cell opposite to the first electrode layer side of the first electrode substrate and the second electrode layer side of the second electrode substrate. It is possible to have a deflection plate arranging step in which a polarizing plate is provided on the surface opposite to the above.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

<Measurement of absorption rate of alignment film PI-1>
The light transmittance and absolute reflectance of a glass substrate provided with a transparent electrode made of an ITO film (hereinafter referred to as an electrode substrate) were measured using a spectrophotometer (V-670 manufactured by JASCO Corporation). The light transmittance of the electrode substrate was determined. The procedure and measurement conditions of the measurement method were carried out in accordance with the details described in the above section "I. Liquid crystal display element". The transparent electrode has a pattern shown in FIG.

Next, a commercially available alignment film PI-1 was placed on the surface of the electrode substrate on which the transparent electrode was formed to obtain an electrode substrate with the alignment film PI-1. The alignment film PI-1 was a polyimide film (average film thickness 100 nm). The light absorption rate of the electrode substrate with the alignment film PI-1 was determined by the same method as the method for measuring the light absorption rate of the electrode substrate, and the light absorption rate of the electrode substrate with the alignment film PI-1 and the light absorption rate of the electrode substrate were determined. When the light absorption rate of the alignment film PI-1 alone was determined from the values, the absorption rate at a wavelength of 365 nm was 2.12%, and the absorption rate at a wavelength of 313 nm was 14.00%.

<Measurement of alignment films PI-2 to PI-6 absorption rate>
One of commercially available alignment films PI-2 to PI-6 (average film thickness: 100 nm) having a composition different from that of the alignment film PI-1 is arranged on the surface of the electrode substrate on which the transparent electrode is formed, and the alignment film is attached. Electrode substrates were obtained respectively. In the same manner as the measurement of the absorption rate of the alignment film PI-1, the values of the light absorption rate of each electrode substrate with the alignment film and the light absorption rate of the electrode substrate are used to determine the individual alignment films PI-2 to PI-6. The light absorption rate was calculated.

Table 1 shows the light absorption rates of the alignment films PI-1 to PI-6 alone at wavelengths of 400 nm, 365 nm, and 313 nm. Further, FIG. 3 shows a graph of the light absorption spectrum of the alignment films PI-1 to PI-6 alone.

[Example 1-1]
<Preparation of polymerizable liquid crystal composition A>
A liquid crystal composition A having the composition shown below, which has a dielectric anisotropy (Δε) of -3.38, was prepared. In addition, "wt%" means "mass%". The liquid crystal composition A has an upper limit temperature (Tni) of the nematic liquid crystal phase of 67.5 ° C., a lower limit temperature (T → n) of the nematic liquid crystal phase of −5 ° C., and a refractive index anisotropy (Δn) of 0.079. there were.

The obtained liquid crystal composition A was mixed with 99.7% by mass and 0.3% by mass of the following polymerizable compound RM-1 to prepare a polymerizable liquid crystal composition A.

<Manufacturing of liquid crystal cell>
A liquid crystal cell was produced as follows using the ODF (One Drop Fill) method. Two electrode substrates with the alignment film PI-1 prepared in the above "Measurement of absorption rate of the alignment film PI-1" are prepared, and ultraviolet photocurability is performed at a predetermined position on one of the electrode substrates with the alignment film PI-1. After applying the sealant of the above and further dropping the polymerizable liquid crystal composition A onto a predetermined number of places on the surface of the alignment film PI-1, the alignment films PI-1 of the two electrode substrates face each other. The other electrode substrate with the alignment film PI-1 was attached, and the polymerizable liquid crystal composition A was spread over the entire surface of the two electrode substrates with the alignment film PI-1. Next, a liquid crystal cell was manufactured by irradiating the entire surface of the electrode substrate with the alignment film PI-1 with ultraviolet light to cure the sealant.

With a voltage applied to the liquid crystal cell, light having a wavelength region of 325 nm to 600 nm was irradiated from one of the liquid crystal cells on the electrode substrate side with the alignment film PI-1 (first light irradiation treatment). The applied voltage is 10 V and 30 Hz alternating current, and a high-voltage mercury lamp (manufactured by Ushio, Inc.) is used as the light source to irradiate, and 100 mW / cm ² light is irradiated for 100 seconds at an intensity of 365 nm to increase the integrated light intensity. The irradiation was carried out so as to be 10 J / cm ² .

Next, light having a wavelength region of 300 nm to 600 nm was irradiated from one of the alignment film PI-1 side of the liquid crystal cell without applying a voltage to the liquid crystal cell (second light irradiation treatment). Using a fluorescent lamp (Toshiba Lighting & Technology Corporation) as a light source for irradiating, by irradiating light of 3 mW / cm ² 3600 seconds at an intensity of 365 nm, integrated light quantity irradiated so that 10.8J / cm ² .. Then, a polarizing plate was attached to the outer surface of each of the two electrode substrates with the alignment film PI-1 on the liquid crystal cell after light irradiation to obtain a liquid crystal display element A1.

[Example 2-1]
A liquid crystal display element B1 was obtained in the same manner as in Example 1-1, except that an electrode substrate with two alignment films PI-2 was used instead of the electrode substrate with two alignment films PI-1.

[Example 3-1]
A liquid crystal display element C1 was obtained in the same manner as in Example 1-1, except that an electrode substrate with two alignment films PI-3 was used instead of the electrode substrate with two alignment films PI-1.

[Example 4-1]
A liquid crystal display element D1 was obtained in the same manner as in Example 1-1, except that an electrode substrate with two alignment films PI-4 was used instead of the electrode substrate with two alignment films PI-1.

[Example 5-1]
A liquid crystal display element E1 was obtained in the same manner as in Example 1-1, except that an electrode substrate with two alignment films PI-5 was used instead of the electrode substrate with two alignment films PI-1.

[Comparative Example 1-1]
A liquid crystal display element F1 was obtained in the same manner as in Example 1-1, except that an electrode substrate with two alignment films PI-6 was used instead of the electrode substrate with two alignment films PI-1.

[Example 1-2]
<Preparation of polymerizable liquid crystal composition B>
A liquid crystal composition B having the composition shown below, which has a dielectric anisotropy (Δε) of −2.59, was prepared. Note that "wt%" means "mass%". The liquid crystal composition B has an upper limit temperature (Tni) of the nematic liquid crystal phase of 85.4 ° C., a lower limit temperature (T → n) of the nematic liquid crystal phase of −58 ° C., and a refractive index anisotropy (Δn) of 0.090. there were.

The above-mentioned polymerizable compound RM-1 was mixed in an amount of 0.3% by mass with 99.7% by mass of the obtained liquid crystal composition B to prepare a polymerizable liquid crystal composition B.

A liquid crystal display element A2 was obtained in the same manner as in Example 1-1, except that the polymerizable liquid crystal composition B was used instead of the polymerizable liquid crystal composition A.

[Example 2-2]
A liquid crystal display element B2 was obtained in the same manner as in Example 1-2, except that an electrode substrate with two alignment films PI-2 was used instead of the electrode substrate with two alignment films PI-1.

[Example 3-2]
A liquid crystal display element C2 was obtained in the same manner as in Example 1-2, except that an electrode substrate with two alignment films PI-3 was used instead of the electrode substrate with two alignment films PI-1.

[Example 4-2]
A liquid crystal display element D2 was obtained in the same manner as in Example 1-2, except that an electrode substrate with two alignment films PI-4 was used instead of the electrode substrate with two alignment films PI-1.

[Example 5-2]
A liquid crystal display element E2 was obtained in the same manner as in Example 1-2, except that an electrode substrate with two alignment films PI-5 was used instead of the electrode substrate with two alignment films PI-1.

[Comparative Example 1-2]
A liquid crystal display element F2 was obtained in the same manner as in Example 1-2, except that an electrode substrate with two alignment films PI-6 was used instead of the electrode substrate with two alignment films PI-1.

<Evaluation of burn-in>
A voltage was applied to each of the produced liquid crystal display elements A1 to F1 and liquid crystal display elements A2 to F2, and the mixture was left for 3 hours with a hatch pattern of white (255 gradation) and black (0 gradation) written. Then, the afterimage of the hatch pattern when the entire surface was made gray (32 gradations) was visually evaluated. The results of the visual evaluation are shown in Tables 2 and 3. In the evaluation, a good level at which the afterimage remains, which cannot be visually recognized, is expressed as ◯, and a bad level, which is clearly visible visually, is expressed as ×. In addition, the level that can be slightly visually confirmed (the lower limit level at which a good product is obtained) is expressed as Δ.

As shown in Tables 2 and 3, Examples 1-1 to Example 5-1 and Example 1-2 using the alignment films PI-1 to PI-5 having a light absorption rate of 365 nm or more and a predetermined value or more are used. It was found that the liquid crystal display element of Example 5-2 showed good seizure characteristics even after irradiation with light (ultraviolet light). On the other hand, in the liquid crystal display elements of Comparative Example 1-1 and Comparative Example 1-2 using the alignment film PI-6 having a wavelength of 365 nm and a light absorption rate smaller than a predetermined value, an afterimage was recognized and good seizure characteristics were obtained. Did not show. Further, the liquid crystal display elements of Examples 2-1 to 5-1 and 2-2-2 to 5-2 are burn-in evaluations more than the liquid crystal display elements of Examples 1-1 and 1-2. The results were even better. This is because, in Examples 2-1 to 5-1 and Examples 2-2-2 to Example 5-2, the light absorption rate at a wavelength of 365 nm is equal to or higher than a predetermined value, and the light absorption rate at a wavelength of 313 nm is high. Alignment films PI-2 to PI-5 having a wavelength of 313 nm or more were used, whereas in Examples 1-1 and 1-2, the alignment films PI-1 having a wavelength of 313 nm were lower than the predetermined values. It is presumed that this is due to the use of.

1 ... 2nd electrode substrate, 2 ... 1st electrode substrate, 10 ... liquid crystal display element, 11 ... 2nd substrate, 12 ... 1st substrate, 13 ... liquid crystal layer, 14 ... 2nd electrode layer, 15 ... 1st electrode layer , 16 ... 2nd alignment film, 17 ... 1st alignment film

Claims (8)

A liquid crystal layer containing a polymer of one or more polymerizable compounds and a liquid crystal composition,
A first electrode substrate having a first electrode layer provided on the surface of the first substrate and the liquid crystal layer side of the first substrate, and a first electrode substrate.
A second electrode substrate having a second electrode layer facing the first electrode substrate via the liquid crystal layer and provided on the surface of the second substrate on the liquid crystal layer side of the second substrate and the second electrode substrate.
A first alignment film arranged between the first electrode substrate and the liquid crystal layer,
Have,
The liquid crystal composition contains one or more alkenyl liquid crystal compounds.
The first alignment film is a liquid crystal display element having an absorption rate of light having a wavelength of 365 nm of 2.0% or more. The liquid crystal display element according to claim 1, wherein the first alignment film has an absorption rate of light having a wavelength of 313 nm of 15% or more. The liquid crystal display device according to claim 1 or 2, wherein the alkenyl liquid crystal compound is a compound represented by the following general formula (i).

(In the general formula (i), R ⁱ¹ may be substituted with one or more halogen atoms, or may be substituted with an alkenyl group having 2 to 8 carbon atoms or one or more halogen atoms. Represents an alkenyloxy group with 2 to 8 atoms
R ⁱ² represents an alkyl group having 1 to 8 carbon atoms, and one or two or more non-adjacent −CH ₂ −s in the alkyl group are independently −CH = CH− and −C≡C−. , -O-, -CO-, -COO- or -OCO- may be substituted.
Z ⁱ¹ represents a single bond or linking group
A ⁱ¹ and A ⁱ² are independent of each other (a) 1,4-cyclohexylene group (one −CH ₂ − present in this group or two or more non-adjacent −CH ₂₋ is −O. (May be replaced with −) and (b) 1,4-phenylene group (one -CH = existing in this group or two or more -CH = not adjacent to each other is replaced with -N =. May be done.)
Representing a group selected from the group consisting of, the above groups (a) and (b) are independently substituted with a cyano group, a fluorine atom, a chlorine atom, a methyl group, a trifluoromethyl group or a trifluoromethoxy group, respectively. May be
^mi1 represents 1-3. ) The liquid crystal display element according to any one of claims 1 to 3, further comprising a second alignment film arranged between the second electrode substrate and the liquid crystal layer. It has a first electrode substrate having a first electrode layer provided on one surface of the first substrate and the first substrate, and a second electrode layer provided on one surface of the second substrate and the second substrate. A second electrode substrate is prepared, and a first alignment film having a wavelength of 365 nm and a light absorption rate of 2.0% or more is provided on the surface of the first electrode substrate on the side of the first electrode layer. Membrane placement process and
The surface of the first electrode substrate having the first alignment film and the surface of the second electrode substrate provided with the second electrode layer are opposed to each other, and the first electrode substrate and the second electrode substrate facing each other are opposed to each other. A liquid crystal cell forming a liquid crystal cell by arranging a polymerizable liquid crystal composition containing one or more kinds of polymerizable compounds and a liquid crystal composition containing one or more kinds of alkenyl liquid crystal compounds in between. The formation process and
A light irradiation step of irradiating the polymerizable liquid crystal composition with light from the first electrode substrate side of the liquid crystal cell to form a polymer of the polymerizable compound and a liquid crystal layer containing the liquid crystal composition.
A method for manufacturing a liquid crystal display element, including. The method for manufacturing a liquid crystal display element according to claim 5, wherein the first alignment film has an absorption rate of light having a wavelength of 313 nm of 15% or more. In the light irradiation step, the polymerizable liquid crystal composition is irradiated with light from the first electrode substrate side of the liquid crystal cell in a state where a voltage is applied between the first electrode substrate and the second electrode substrate. 1 light irradiation treatment and
After the first light irradiation treatment, light is applied to the polymerizable liquid crystal composition from the first electrode substrate side of the liquid crystal cell in a state where no voltage is applied between the first electrode substrate and the second electrode substrate. The method for manufacturing a liquid crystal display element according to claim 5 or 6, further comprising a second light irradiation treatment for irradiating the liquid crystal display element. The method for manufacturing a liquid crystal display element according to claim 7, wherein the second light irradiation treatment irradiates light containing more light having a wavelength of 313 nm than the light irradiated by the first light irradiation treatment.

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