TWI755503B - Manufacturing method of liquid crystal display element - Google Patents

Abstract

Provided is a method of manufacturing a liquid crystal display element, which is independently provided with a liquid crystal display element of a liquid crystal display element having an irradiating step of irradiating a liquid crystal composition containing a polymerizable compound attached on a substrate to light having a peak of 300 to 400 nm for 1 to n times. The manufacturing method is characterized in that: under the illumination conditions of the k-th illuminating step (S _k ) among the 1-n illuminating steps, the liquid crystal composition containing 0.3 mass % of the polymerizable compound is irradiated for 5 minutes. The concentration (C _k ) of the polymerizable compound and the concentration change V _k per unit minute of the difference from the concentration of 0.3 mass % are expressed by the formula (1) for each step, and the formula (2) is expressed as The average reaction rate Vave of the aforementioned polymerizable compound in the full illumination step ( _{ΣS k} ) is controlled to be 0.030-0.048 (mass %/min).

Description

Manufacturing method of liquid crystal display element

The present invention relates to a method for producing a liquid crystal display element using a liquid crystal composition containing a polymerizable compound.

PSA (Polymer Sustained Alignment, polymer stabilized alignment) type liquid crystal display device has a structure in which a polymer structure is formed in the unit cell in order to control the pretilt angle of liquid crystal molecules, and is used as a liquid crystal display due to high speed response and high contrast. components are developed.

A PSA-type liquid crystal display element is produced by using the following method (Patent Document 1): injecting a liquid crystal composition containing a polymerizable compound between substrates, applying a voltage to irradiate the liquid crystal molecules with ultraviolet rays in an aligned state, and polymerizing them by applying a voltage. The pre-tilt angle of the liquid crystal molecules is controlled by the polymer structure formed by the polymerization of the compound, thereby fixing the alignment of the liquid crystal molecules.

Such a PSA type liquid crystal display element becomes a liquid crystal display element showing a low VHR (Voltage Holding Ratio) value if the polymerizable compound used to generate the pretilt angle remains in the display as a non-polymer even after the polymerization step. On the other hand, there are cases in which display defects such as burn-in occur, and therefore, the development of a polymerizable compound or the like which does not remain or hardly remains unpolymerized (Patent Documents 1 and 2).

Specifically, according to Patent Document 1, it is described that while a voltage is applied between a pair of transparent electrodes, one or more ring structures or condensed ring structures and one or more ring structures or condensed ring structures are directly bonded to each other. Monomers with two functional groups are polymerized to form a polymer structure, thereby reducing branding.

In addition, according to Patent Document 2, it is described that the radical polymerizable monomer system generates radicals by irradiation with ultraviolet rays and the like, and forms a polymer structure by polymerization, but for example, lauryl acrylate has only one polymerizable The polymerization rate decreases due to the radicals, and the free radicals generated by the polymerizable groups at the ends of polymerization will remain in the liquid crystal layer as impurities, which is the reason for the decrease in VHR. The compound in which two polymerizable groups are bonded is further bonded to a radical polymerizable monomer formed by a hydrocarbon group having 12 or more carbon atoms, so that liquid crystal molecules can be aligned and a high VHR can be maintained.

prior art literature Patent Literature

Patent Document 1 Japanese Patent Laid-Open No. 2003-307720

Patent Document 2 Japanese Patent Application Laid-Open No. 2016-6130

The above-mentioned Patent Documents 1 and 2 are both techniques focusing on the structure of the polymerizable compound used in the polymerization step. For example, Patent Document 1 describes the use of a polymerizable compound with a specific chemical structure to adjust the pouring direction of liquid crystal molecules to reduce burn-in. However, A new problem of lowering of VHR due to unpolymerized polymerizable compound or poor display caused by this occurs. Further, Patent Document 2 describes that when the number of polymerization sites is 1, the polymerization rate of the polymerizable compound is slow and the VHR is lowered, and when the number of polymerization sites is 2, the polymerization rate of the polymerizable compound is increased and a high VHR is maintained. Since the polymerization speed of the polymerizable compound affects the shortening of the manufacturing steps or the energy cost of the liquid crystal display element of the product, there is a need to speed up the polymerization speed of the polymerizable compound. However, in the step of polymerizing the polymerizable compound in the liquid crystal composition used in the PSA type liquid crystal display element, if the polymerization rate of the polymerizable compound is high, the residual amount of the polymerizable compound will be reduced in a short ultraviolet irradiation time. Therefore, the reduction of the VHR derived from the polymerizable compound described in Patent Document 2 can be reduced, but a new problem of poor display easily caused by a change in the pretilt angle arises. On the other hand, when the polymerization rate of a polymerizable compound is slow, in order to reduce the residual amount of a polymerizable compound, a long ultraviolet irradiation time becomes necessary. Therefore, when a strong ultraviolet ray is irradiated for a long time in the step of polymerizing, a new problem of deterioration of the liquid crystal composition due to ultraviolet rays occurs, while causing the enlargement of the manufacturing apparatus and the reduction of the manufacturing efficiency.

Therefore, the problem to be solved by the present invention is to provide a method of manufacturing a liquid crystal display element, which is a method for manufacturing a PSA type liquid crystal display device for a liquid crystal composition containing a polymerizable compound. In the polymerization step of light irradiation, by allowing the polymerizable compound to proceed at an appropriate polymerization rate, there is no or very little display failure due to changes in the pretilt angle, and reduction in VHR or display failure caused by it is reduced or suppressed.

The inventors of the present invention, as a result of intensive research, found that the above-mentioned problems can be solved by setting the polymerizable compound to an appropriate polymerization rate, and further completed the present invention.

The liquid crystal display element using the manufacturing method of the liquid crystal display element of the present invention is one that suppresses and reduces the decrease in VHR.

The liquid crystal display element using the manufacturing method of the liquid crystal display element of the present invention has little or no display failure due to the change of the pretilt angle.

The liquid crystal display element using the method for producing a liquid crystal display element of the present invention has a small residual amount of polymerizable compounds, exhibits high voltage holding ratio (VHR) and high-speed response, and exhibits excellent display defects such as no or suppression of misalignment, burn-in, etc. display quality.

The liquid crystal display element using the method for manufacturing the liquid crystal display element of the present invention can easily improve the production efficiency by appropriately shortening the irradiation time of ultraviolet rays, optimizing and reducing the energy cost.

FIG. 1 is a graph showing the relationship between the voltage holding ratio VHR and the irradiation time in the method for manufacturing a liquid crystal display element of the present invention.

The most important aspect of the present invention is a method of manufacturing a liquid crystal display element, which comprises independently irradiating a liquid crystal composition containing a polymerizable compound loaded on a substrate with a wave peak at 300 to 400 nm for 1 to n times. The method of manufacturing a liquid crystal display element in the light irradiation step is characterized in that: under the lighting conditions of the kth irradiation step (S _k ) among the aforementioned 1 to n irradiation steps, the polymerizable content of 0.3 mass % of the aforementioned polymerizable The concentration (C _k ) of the polymerizable compound after the liquid crystal composition of the compound was irradiated for 5 minutes, and the concentration change V _k per unit minute of the difference from the concentration of 0.3 mass % were calculated by the following formula (1) for each step. When expressed, the average reaction rate Vave of the polymerizable compound in the total irradiation step ( _{ΣS k} ) represented by the following formula (2) is controlled to be 0.030 to 0.048 (mass %/min).

(In the above formula (1), C _k represents the liquid crystal composition containing 0.3 mass % of the polymerizable compound under the illumination conditions of the k-th illumination step (S _k ), the liquid crystal composition after irradiating for 5 minutes. The concentration (mass %) of the polymerizable compound, in the above formula (2), V _k is represented by the above formula (1), and t _k represents the irradiation time (minutes) for irradiating the polymerizable compound in the k-th irradiation step) .

Thereby, the liquid crystal display element using the manufacturing method of the liquid crystal display element of the present invention can suppress or reduce the decrease of VHR, and display failure due to the change of the pretilt angle is not or very little.

In general, the method of manufacturing a liquid crystal display element can be roughly divided into a method of filling a liquid crystal composition between a pair of (electrode) substrates by vacuum injection (ie, a vacuum injection method), and a method of filling a pair of (electrode) substrates with a liquid crystal composition by vacuum injection. A method of dropping a liquid crystal composition on at least one (electrode) substrate (ie, the ODF method). When the method for manufacturing the liquid crystal display element of the present invention is carried out by the former vacuum injection method, it is preferable to have the following steps according to needs: manufacturing a liquid crystal having a liquid crystal cell having a (electrode) substrate provided with a pair of alignment films The unit cell fabrication step; the injection step of attaching and filling the liquid crystal composition containing the polymerizable compound on the aforementioned (electrode) substrate by vacuum injection in the aforementioned liquid crystal unit cell; The irradiating step of irradiating the liquid crystal composition of the polymerizable compound to light having a wave peak at 300-400 nm; and the step of attaching the polarizer. In the above-mentioned manufacturing method, the liquid crystal cell filled with the liquid crystal composition may be annealed under the conditions of 60 to 130° C. after the injection step and before the irradiation step as required. In addition, the above-mentioned irradiating step is performed once or more, and it is preferable to perform the irradiating step once or more in a state where a voltage is applied.

When carrying out the manufacturing method of the liquid crystal display element of the present invention by the latter ODF method, it is preferable to have the following steps according to the needs: a (electrode) substrate manufacturing step of making a pair of (electrode) substrates provided with an alignment film; At least one of the above-mentioned (electrode) substrates on one side of the peripheral portion, with the sealing agent for joining the process of drawing the area for joining over the entire periphery; attaching a liquid crystal composition containing a polymerizable compound to the above-mentioned (electrode) substrate After the inner side of the aforementioned bonding area on one side, the step of bonding with another (electrode) substrate and curing the aforementioned bonding sealant; irradiating the liquid crystal composition containing the polymerizable compound attached to the aforementioned (electrode) substrate The step of illuminating light with peaks at 300-400 nm; and the step of attaching the polarizer. In addition, the above-mentioned irradiating step is performed once or more, and it is preferable to perform the irradiating step once or more in a state where a voltage is applied.

It is preferable that the said sealing compound for joining is hardened by the resin which hardens|cures by UV or heat, and it is preferable to use a well-known thermosetting type sealing compound.

In the manufacturing method of the liquid crystal display element of the present invention, the irradiation step of irradiating the liquid crystal composition containing the polymerizable compound attached to the substrate with light having a wave peak at 300 to 400 nm is performed 1 to n times, preferably 1 ~5 times, more preferably 1~4 times, more preferably 1~3 times, and particularly preferably 1~2 times.

By performing 1 to n times of irradiation steps, the amount of residual monomers that cause the reduction of VHR can be reduced and a desired pretilt angle can be formed.

In the manufacturing method of the present invention, the irradiating step of irradiating the liquid crystal composition containing the polymerizable compound attached on the substrate to light having a peak at 300-400 nm is performed 1-n times independently of each other, for example, when 1-n The k-th (1≦k≦n) illumination step among n times is S _k , and the f-th (1≦f≦n, k≠f) illumination step among 1 to n times is S _f At the same time, the irradiation conditions of the _k -th illuminating step (S _k ) (the wavelength of the irradiated light, the accumulated light amount or illuminance, the gas environment, etc.) , cumulative light quantity or illuminance, gas environment, etc.) are the same or different. In addition, when performing the irradiation step once, it is a matter of course that the irradiation conditions for one time are independent.

The formula (1) of the present invention represents the concentration (C _k ) of the polymerizable compound after irradiating a liquid crystal composition containing 0.3 mass % of the polymerizable compound for 5 minutes under the lighting conditions of a certain lighting step, and 0.3 The concentration change amount per unit minute of the concentration difference in mass %, the concentration change amount (V _k ) is set as an index indicating the reactivity of the polymerizable compound under the illumination conditions of the above-mentioned certain illumination step. In other words, the concentration of the polymerizable compound contained in the liquid crystal composition is set to 0.3 mass % (set to be equal to the reference concentration) in order to calculate the index representing the reactivity of the polymerizable compound under the illumination conditions of the certain illumination step. , and the 5-minute illumination time is set as the rate of change at the reference time. For example, when V _k is measured in a method for manufacturing a liquid crystal display element in which a liquid crystal composition containing 0.2 mass % of a polymerizable compound is irradiated with light having a peak at 300 to 400 nm for 1 to n times at 20° C. A liquid crystal composition containing 0.3 mass % of the polymerizable compound is prepared, and the liquid crystal composition containing the polymerizable compound is filled between 1 to k pairs of (electrode) substrates, and then 1 to k are respectively filled with the above-mentioned liquid crystal composition. The (electrode) substrates of a pair of liquid crystal compositions containing a polymerizable compound were measured at 20°C under the illumination conditions of the illumination steps (S ₁ ) to (S _k ) and after 5 minutes under the same conditions. The concentrations C ₁ , C ₂ . . . C _k of the polymerizable compounds contained in the composition are calculated, and the corresponding V ₁ , V ₂ . . . V _k are calculated. Similarly, for example, V _k is measured in a method for manufacturing a liquid crystal display element in which a liquid crystal composition containing 0.4 mass % of a polymerizable compound is irradiated with light having a peak at 300 to 400 nm for 1 to n times at 25° C. During the process, a liquid crystal composition containing 0.3 mass % of the polymerizable compound is prepared, and the liquid crystal composition containing the polymerizable compound is filled between 1 to k pairs of (electrode) substrates, respectively. The (electrode) substrate filled with one pair of the aforementioned liquid crystal composition containing the polymerizable compound was measured at 25°C under the illumination conditions of the illumination steps (S ₁ ) to (S _k ) and after 5 minutes under the same conditions. Concentrations C ₁ , C ₂ . . . C _k of the polymerizable compounds contained in the respective liquid crystal compositions were calculated, and corresponding V ₁ , V ₂ . . . V _k were calculated. In addition, the temperature of the polymerizable compound at the time of measuring V _k (or the temperature of the gas atmosphere in the step of measuring V _k ) is determined by the temperature of the polymerizable compound at the time of illumination in each illumination step (S _k ) (or the corresponding illumination). It is preferred that the temperature of the gas environment in the step (S _k ) is the same.

The irradiation conditions (liquid crystal cell (a pair of (electrode) substrates), the wavelength of the irradiated light, the accumulated light amount or illuminance, and the gas environment) when measuring the above V _k are the same as the actual irradiation of each irradiation step (S _k ). It is preferable that the conditions (liquid crystal cell (a pair of (electrode) substrates), wavelength of light to be irradiated, accumulated light quantity or illuminance, and gas environment) are the same.

In the formula (2) of the present invention, the product of the concentration change rate of the polymerizable compound under the irradiation conditions of each irradiation step (S _k ) and the irradiation time of each irradiation step represents the apparent decrease in each irradiation step The concentration of the polymerizable compound; the sum of the total steps of the concentration represents the total concentration of the "apparent" reduced polymerizable compound in the full illumination step; if the "apparent" reduced polymerizability in the full illumination step The concentration of the compound divided by the full illumination time represents the "apparent" reaction rate of the polymerizable compound in the full illumination step. Therefore, the average reaction rate _Vave in the present invention represents the "apparent" reaction rate of the polymerizable compound in the full-illumination step. Therefore, it is possible to provide a method of manufacturing a liquid crystal display element, which can reduce or suppress the decrease or cause of VHR by controlling the average response speed V _ave to a specific range, without or with little or no display failure due to a change in the pretilt angle. The display here is poor.

The lower limit of the average reaction rate _Vave (mass %/min) in the present invention is preferably 0.030 or more, 0.031 or more, 0.032 or more, 0.033 or more, and 0.034 or more, and the upper limit of the average reaction rate _Vave in the present invention is preferably It is preferably 0.048 or less, 0.047 or less, 0.046 or less, 0.045 or less, 0.044 or less, and 0.043 or less. In addition, the average reaction rate V _ave of the present invention is preferably 0.030-0.048, more preferably 0.032-0.04, further more preferably 0.032-0.047, further more preferably 0.032-0.045, and even more preferably 0.033-0.045 Good, 0.033~0.045 is very good.

If the lower limit of the average reaction rate _Vave of the present invention is 0.030, there is an advantage that the reduction of VHR due to long-term illumination is difficult to occur; if the upper limit is 0.048, the change of the pretilt angle is difficult to occur. The advantages of imprinting.

The illumination conditions of the illumination step (S _k ) of the present invention preferably include the wavelength of the peak of the illumination light and/or the illumination intensity of the illumination light.

In the manufacturing method of the liquid crystal display element of this invention, the light which irradiates a polymerizable compound is light which has a peak at 300-400nm, Preferably it is ultraviolet light. The light used in the illuminating step (S _k ) of the present invention preferably has a peak near 313 nm or a peak near 365 nm, more preferably has a peak near 313 nm and a peak near 365 nm, and has a peak near 313 nm Excellent. If it has a peak in the vicinity of 313 nm, since the reaction rate of the polymerizable compound is increased, the irradiation time may be short, and there is an advantage that the reduction in VHR due to long-term light irradiation hardly occurs. Moreover, a well-known cut filter (cut filter) can also be used to cut light of a specific wavelength or below as needed. In the illumination of the present invention, it is preferable to cut off light in the range of 300 to 350 nm or less, for example, the embodiment in which the light of 320 nm or less is cut off and the light of 325 nm or less is cut off.

Thereby, there is an advantage that the reaction rate of the polymerizable compound can be easily adjusted.

In the illuminating step (S _k ) of the present invention, the lower limit of the illuminance for irradiating light with a wave peak at 300-400 nm is preferably 10mW/cm ² , 20mW/cm ² is better, and 30mW/cm ² is further more good. The upper limit of the illuminance of the irradiated light is preferably 1500 mW/cm ² , more preferably 1000 mW/cm ² , and even more preferably 800 mW/cm ² .

In the illuminating step (S _k ) of the present invention, when irradiating light with a peak near 313 nm and/or light having a peak near 365 nm, the light irradiated in the illuminating step (S _k ) of the present invention (313 nm) The lower limit of illuminance is preferably 0.1mW/cm ² , more preferably 0.3mW/cm ² , and even more preferably 2mW/cm ² . The upper limit of the illuminance of the irradiated light (313 nm) is preferably 30mW/cm ² , more preferably 25mW/cm ² , and even more preferably 20mW/cm ² .

If the lower limit of the illuminance of the irradiated light (313 nm) is 2 mW/cm ² , it is preferable from the viewpoint that the average reaction rate of the polymerizable compound can be controlled within the range of 0.030 to 0.048. If the upper limit of the illuminance of the ultraviolet rays used is 20 mW/cm ² , it is preferable from the viewpoint that the average reaction rate of the photopolymerizable compound can be controlled within the range of 0.030 to 0.048.

In the illuminating step (S _k ) of the present invention, when irradiating light with a peak near 313 nm and/or light having a peak near 365 nm, the light irradiated in the illuminating step (S _k ) of the present invention (365 nm) The lower limit of illuminance is preferably 0.1mW/cm ² , more preferably 0.5mW/cm ² , and even more preferably 1mW/cm ² . The upper limit of the illuminance of the irradiated light (365 nm) is preferably 150 mW/cm ² , more preferably 130 mW/cm ² , and even more preferably 120 mW/cm ² .

If the lower limit of the illuminance of the irradiated light (365 nm) is 1 mW/cm ² , it is preferable from the viewpoint that the average reaction rate of the polymerizable compound can be controlled within the range of 0.030 to 0.048. If the upper limit of the illuminance of the ultraviolet rays used is 120 mW/cm ² , it is preferable from the viewpoint that the average reaction rate of the photopolymerizable compound can be controlled within the range of 0.030 to 0.048.

The method for measuring the illuminance of the irradiated light in the present invention is not particularly limited, and can be carried out by well-known methods and devices, and the method for measuring the illuminance of the irradiated light in this specification uses the USHIO electric mechanism UVD- S313, use the USHIO motor UVD-S365 at the illuminance of 365nm.

The illumination time (t _k ) in the illumination step (S _k ) of the present invention is appropriately determined by the number of illumination steps, etc., and is preferably 0.5 to 100 minutes. In the above-mentioned irradiation step, the lower limit of the irradiation time is preferably 0.5 minutes, more preferably 1 minute, and particularly preferably 1.5 minutes. The upper limit of the irradiation time of the ultraviolet rays is more preferably 60 minutes, more preferably 50 minutes, and particularly preferably 45 minutes.

When a strong ultraviolet ray is irradiated for a long time in the step of polymerizing, the size of the manufacturing apparatus is increased, the manufacturing efficiency is reduced, and the deterioration of the liquid crystal composition due to ultraviolet rays occurs. On the other hand, if the irradiation time of ultraviolet rays is shortened, the occurrence of branding, which is one of display failures by the residual polymerizable compound, cannot be avoided. If the irradiation step is the above-mentioned conditions, as will be described later, the unreacted polymerizable compound can be intentionally left in the entire composition, and the remaining unreacted polymerizable compound can be used by further performing the irradiation step.

The illumination time (Σt _k ) in the full illumination step (ΣS _k ) of the present invention is appropriately determined by the number of illumination steps, etc., and is preferably 5 to 100 minutes. In the above-mentioned illuminating step, the lower limit of the irradiation time is preferably 5 minutes, more preferably 10 minutes, and particularly preferably 15 minutes. The upper limit of the above-mentioned ultraviolet irradiation time is more preferably minutes, more preferably 70 minutes, and particularly preferably 60 minutes.

The temperature range of the gas environment in the illuminating step (S _k ) of the present invention is preferably 19°C to 63°C, more preferably 20°C to 50°C. Furthermore, the temperature of the gas environment in the calculation of the concentration change rate (V _k ) corresponding to the irradiation step (S _k ) is preferably the same as the temperature of the gas environment in the irradiation step (S _k ). That is, the temperature of the gas environment (or the polymerizable compound) when the concentration (V _k+1 ) of the reference concentration of the polymerizable compound contained in the liquid crystal composition decreases after 5 minutes of 0.3 mass % is calculated, and V _k+ It is preferable that the temperature of the gas environment of the illuminating step (S _{k+1 )} corresponding to 1 is the same.

In addition, the wavelength range of ultraviolet rays in this specification is set to 200-380 nm, and the wavelength range of visible light is set to 380-780 nm.

When ultraviolet rays are used, a polarized light source or a non-polarized light source can be used in the illumination step (S _k ) of the present invention, and it is preferable to irradiate unpolarized ultraviolet rays.

In the illuminating step (S _k ) of the present invention, the gas environment for illuminating is not particularly limited, and it can be in an atmospheric environment, or in a nitrogen or rare gas environment.

The irradiation method that can be used in the irradiation step (S _k ) of the present invention is not particularly limited, and a known irradiation method can be used.

In the present invention, as a lamp for generating light to irradiate a polymerizable compound, a low-pressure mercury lamp, a metal halide lamp, a high-pressure mercury lamp, a fluorescent UV lamp, an ultra-high pressure mercury lamp, a chemical lamp, an LED light source, and an excimer laser can be used. Radiation generating devices, etc., preferably active light rays with wavelengths of 300nm to 450nm, such as j-line (313nm), i-line (365nm), h-line (405nm), g-line (436nm), etc., can be used, and j-line ( 313nm) is preferably active light with a wavelength of 300nm or more and 400nm or less.

In addition, the irradiated light can also be adjusted through a spectral filter such as a long-wavelength cut-off filter, a short-wavelength cut-off filter, and a band-pass filter according to needs, and ultraviolet rays can also be cut off according to needs.

Furthermore, as the wavelength of the ultraviolet rays irradiated in the irradiating step (S _k ) of the present invention, the above-mentioned ultraviolet rays with a wavelength of 300 to 400 nm may be included, and ultraviolet rays in a wavelength region that is not an absorption wavelength region of the polymerizable compound may be irradiated. The active energy rays such as ultraviolet rays to be irradiated are preferably those having a plurality of spectra, and those having a plurality of spectra are preferably ultraviolet rays. By irradiating active energy rays having a plurality of spectra, the polymerizable compound can be polymerized by active energy rays suitable for each type of spectrum (wavelength), and at this time, the alignment of the liquid crystal molecules can be formed more efficiently. direction of the polymer.

In order to polymerize the polymerizable compound contained in the liquid crystal composition of the present invention to obtain good alignment properties of the liquid crystal, a moderate polymerization rate is desired, so in addition to ultraviolet rays, electron beams may be irradiated alone or in combination or sequentially. A method that waits for active energy rays to polymerize.

In addition, when the liquid crystal composition containing the polymerizable compound is irradiated with ultraviolet rays in a state sandwiched between two substrates (polymerization is performed), at least the substrate on the irradiated surface side is provided with appropriate transparency for ultraviolet rays. good. Moreover, after polymerizing only a specific part using a mask during irradiation, changing the conditions of an electric field, a magnetic field, etc. to change the alignment state of the unpolymerized part, and irradiating it with ultraviolet rays to polymerize it can also be used.

In the manufacturing method of the liquid crystal display element of this invention, it is preferable to irradiate in the state which applied a voltage in at least 1 illuminating step ( _Sk ) among 1-n illuminating steps.

By further irradiating the liquid crystal composition containing the polymerizable compound with light of a predetermined wavelength in a state where a voltage is applied, a stable pretilt angle of the liquid crystal molecules can be formed by the polymer derived from the remaining polymerizable compound. In more detail, it is as follows: in the irradiation step (S _k ), the alignment direction of the liquid crystal molecules constituting the liquid crystal composition containing the polymerizable compound is aligned to a specific direction with respect to the substrate by the polymerized polymer (Sk). For example, the vertical direction relative to the substrate), the polymer polymerized by the irradiation step is further used to form a stable pretilt angle according to needs, so that the liquid crystal molecules can be immobilized in the vertical alignment. Thereby, for example, when the voltage is ON, the liquid crystal molecules are aligned in parallel in the direction from the outer side of the fishbone structure toward the center, so that a multi-domain liquid crystal display element can be manufactured.

When irradiating ultraviolet rays in the illuminating step (S _k ) of the present invention, it is preferable to irradiate ultraviolet rays while applying AC voltage or DC voltage, and it is more preferable to irradiate ultraviolet rays while applying AC voltage.

The lower limit of the frequency of the applied AC voltage is preferably 10 Hz, and more preferably 60 Hz. In addition, the upper limit of the frequency of the applied AC voltage is preferably 10 kHz, and more preferably the frequency is 1 kHz.

The magnitude of the voltage applied in the illumination step (S _k ) of the present invention is selected depending on the desired pretilt angle of the liquid crystal display element. In other words, the pretilt angle of the liquid crystal display element can be controlled by the applied voltage. The lower limit value of the magnitude of the voltage applied in the illuminating step (S _k ) is preferably 0.1V, more preferably 0.2V, and still more preferably 0.5V. The upper limit of the magnitude of the voltage applied in the above-mentioned illuminating step is preferably 30V, more preferably 20V, and still more preferably 10V.

The temperature of the liquid crystal composition containing the polymerizable compound when a voltage is applied in the illuminating step (S _k ) of the present invention is a temperature close to room temperature, preferably 14-62° C., more preferably 16-55° C., More preferably, a voltage is applied to the liquid crystal composition containing the polymerizable compound at 18 to 52°C.

The liquid crystal composition containing the polymerizable compound is preferably in a nematic phase state when a voltage is applied in the irradiation step of the present invention.

In order to irradiate an ultraviolet-ray in the state which applied a voltage, it is preferable that the liquid crystal composition containing a polymerizable compound is a nematic phase from the viewpoint of uniform alignment.

Hereinafter, preferred embodiments in the manufacturing method of the liquid crystal display element of the present invention will be described.

One aspect of the method for producing a liquid crystal display element of the present invention is a method for producing a liquid crystal display element including an irradiation step of irradiating a liquid crystal composition containing a polymerizable compound attached to a substrate with light having a peak at 300 to 400 nm once. , wherein the concentration of the polymerizable compound (C ₁ ) after irradiating the liquid crystal composition containing 0.3 mass % of the polymerizable compound for 5 minutes under the lighting conditions of the first lighting step (S ₁ ), and When the concentration change V ₁ per unit minute with the concentration difference of 0.3 mass % is represented by the following formula (1-1), the above-mentioned first irradiation step (S ₁ ) represented by the following formula (2-1) is used. ), the average reaction rate _Vave of the aforementioned polymerizable compounds is controlled to be 0.030 to 0.048 (mass %/min).

(In the above formula (1-1), C ₁ represents the concentration (mass %) of the polymerizable compound contained in the liquid crystal composition after 5 minutes under the illumination conditions of the first illumination step (S ₁ ), the above formula In (2-1), V ₁ is represented by the above formula (1-1), and t ₁ represents the irradiation time (minutes) for irradiating the polymerizable compound in the first irradiation step (S ₁ ).

When one irradiation step is performed, a desired pretilt angle can be formed in one irradiation step, the number of steps can be omitted, and there is an advantage that only one light irradiation device is required.

In the illuminating step (S ₁ ) of the present invention, when illuminating, preferably irradiating ultraviolet rays, it is preferable to irradiate ultraviolet rays while applying AC voltage or DC voltage, and it is more preferable to irradiate light (ultraviolet rays) while applying AC voltage.

The lower limit of the frequency of the applied AC voltage is preferably 10 Hz, and more preferably 60 Hz. In addition, the upper limit of the frequency of the applied AC voltage is preferably 10 kHz, and more preferably the frequency is 1 kHz.

The magnitude of the voltage applied in the illumination step (S ₁ ) of the present invention is selected depending on the desired pretilt angle of the liquid crystal display element. In other words, the pretilt angle of the liquid crystal display element can be controlled by the applied voltage. The lower limit value of the magnitude of the voltage applied in the illuminating step (S ₁ ) is preferably 0.1V, more preferably 0.2V, and still more preferably 0.5V. The upper limit of the magnitude of the voltage applied in the above-mentioned illuminating step is preferably 30V, more preferably 20V, and still more preferably 10V.

The temperature of the gas environment when the voltage is applied in the illuminating step (S ₁ ) of the present invention is a temperature close to room temperature, preferably 14-62° C., more preferably 16-55° C., and even more preferably 18-52° C. It is preferable to apply a voltage to the liquid crystal composition containing the polymerizable compound at ℃.

When the above-mentioned irradiation step is performed once, the concentration (C ₁ ) of the polymerizable compound after irradiating the liquid crystal composition containing 0.3 mass % of the polymerizable compound with light for 5 minutes and the unit of the concentration difference from 0.3 mass % are measured. The temperature of the gas environment irradiated with light for 5 minutes at the time of the minute concentration change V ₁ is preferably the same as the temperature of the gas environment irradiated with light having a peak of 300-400 nm in the illuminating step (S ₁ ).

When the above-mentioned irradiation step is performed once, the concentration (C ₁ ) of the polymerizable compound after irradiating the liquid crystal composition containing 0.3 mass % of the polymerizable compound with light for 5 minutes and the unit of the concentration difference from 0.3 mass % are measured. The illuminance of the light irradiated for 5 minutes when the concentration change amount V ₁ in minutes is preferably the same as the illuminance of the light irradiated in the irradiating step (S ₁ ).

When the above-mentioned irradiation step is performed once, the concentration (C ₁ ) of the polymerizable compound after irradiating the liquid crystal composition containing 0.3 mass % of the polymerizable compound with light for 5 minutes and the unit of the concentration difference from 0.3 mass % are measured. It is preferable that the light irradiated for 5 minutes at the time of minute concentration change V ₁ is the same as the light irradiated in the irradiating step (S ₁ ).

Another aspect of the method for producing a liquid crystal display element of the present invention is a liquid crystal display element including an irradiation step of irradiating the liquid crystal composition containing the polymerizable compound attached to the substrate twice with light having a peak at 300 to 400 nm, respectively. The manufacturing method, wherein the concentration (C ₁ ) of the polymerizable compound after irradiating the liquid crystal composition containing 0.3 mass % of the polymerizable compound for 5 minutes under the lighting conditions of the first lighting step (S ₁ ) , and the concentration difference V1 per unit minute with the concentration difference of 0.3 mass % is represented by the following formula ( _1-1 ), for the liquid crystal composition containing 0.3 mass % of the aforementioned polymerizable compound in the second irradiation step The concentration (C ₂ ) of the polymerizable compound after irradiating for 5 minutes under the illumination conditions of (S ₂ ), and the concentration change V ₂ per unit minute of the concentration difference from 0.3 mass % are expressed by the following formula (1-2 ), the average reaction rate _Vave of the polymerizable compound represented by the following formula (2-2) is controlled to be 0.030 to 0.048 (mass %/min).

(In the above formulas (1-1) and (1-2), C ₁ represents that the liquid crystal composition containing 0.3 mass % of the polymerizable compound is irradiated for 5 minutes under the lighting conditions of the first irradiation step (S ₁ ) The concentration (mass %) of the aforementioned polymerizable compound after that, C ₂ represents the aforementioned polymerization after 5 minutes of irradiation with the liquid crystal composition containing 0.3 mass % of the polymerizable compound under the lighting conditions of the second irradiation step (S ₂ ). The concentration (mass %) of the chemical compound, in the above formula (2-2), V ₁ and V ₂ represent the concentration change amount per unit minute shown by the above formula (1-1) and formula (1-2), t ₁ and t ₂ represent the irradiation time (minutes) for irradiating the polymerizable compound in each step.

If the irradiation step is divided into two steps, since the liquid crystal panel that can be processed at one time increases, it is preferable from the viewpoint that liquid crystal display elements can be mass-produced. In addition, since it can be divided into a step of forming a pretilt by the first irradiation and a step of reducing the concentration of the remaining polymerizable compound by the second irradiation, it is easy to adjust the reduction of the remaining amount of the polymerizable compound and the desired formation. pretilt operation.

In the method for producing a liquid crystal display element of the present invention, when the step of irradiating the liquid crystal composition containing the polymerizable compound attached to the substrate with light having a peak in the range of 300 to 400 nm is provided twice independently, the above-mentioned step In the first irradiating step (S ₁ ), it is preferable to irradiate light having a peak at 300 to 400 nm in a state where a voltage is applied.

First, the liquid crystal composition containing the polymerizable compound is irradiated with light of a predetermined wavelength in a state where a voltage is applied, that is, in the first irradiation step (S ₁ ), using the polymer (polymer structure) derived from the polymerizable compound Then, the liquid crystal molecules are formed into a desired pretilt angle, and the second irradiation step (S ₂ ) is performed without applying a voltage, so that the shape of the polymer structure can be reinforced and the residual polymerizable compound can be reduced. For example, the liquid crystal composition is oriented to a VA type liquid crystal display element in a vertical direction with respect to the substrate when no voltage is applied, as an example for description. That is, by performing the irradiation step (S ₁ ) in a state where a voltage is applied, the liquid crystal molecules constituting the liquid crystal composition containing the polymerizable compound are aligned relative to the substrate in a specific alignment direction, for example, when a voltage is applied. In a state similar to the horizontal direction, the polymerizable compound is polymerized. Therefore, if the state is set to no voltage applied thereafter, the liquid crystal molecules can be polymerized by the polymerizable compound. The substrate is immobilized in a state where the vertical direction is slightly inclined to the substrate side (pre-tilt angle); by further performing the second irradiation step (S ₂ ) without applying a voltage, the shape of the polymer structure can be reinforced, and Reduce residual polymeric compounds. Thereby, a liquid crystal display element which realizes a desired pretilt angle and a high VHR value can be manufactured. In addition, it is considered that in the present invention, by controlling the average reaction rate of the polymerizable compound to a predetermined range, it is possible to control the formation of the first irradiation step (S ₁ ) and/or the second irradiation step (S ₂ ). Because of the formation speed and shape of the polymer structure, an appropriate pretilt angle and a liquid crystal display element with a reduced amount of residual polymerizable compound can be produced.

When irradiating ultraviolet rays in the irradiation step (S ₁ ) of the present invention, it is preferable to irradiate ultraviolet rays while applying AC voltage or DC voltage, and it is more preferable to irradiate ultraviolet rays while applying AC voltage.

The lower limit of the frequency of the applied AC voltage is preferably 10 Hz, and more preferably 60 Hz. In addition, the upper limit of the frequency of the applied AC voltage is preferably 10 kHz, and more preferably the frequency is 1 kHz.

The magnitude of the voltage applied in the illumination step (S ₁ ) of the present invention is selected depending on the desired pretilt angle of the liquid crystal display element. In other words, the pretilt angle of the liquid crystal display element can be controlled by the applied voltage. The lower limit value of the magnitude of the voltage applied in the illuminating step (S ₁ ) is preferably 0.1V, more preferably 0.2V, and still more preferably 0.5V. The upper limit of the magnitude of the voltage applied in the above-mentioned illuminating step is preferably 30V, more preferably 20V, and still more preferably 10V.

In the method for producing a liquid crystal display element of the present invention, when the step of irradiating the liquid crystal composition containing the polymerizable compound attached to the substrate with light having a peak at 300 to 400 nm is provided twice independently, the first After the illumination step (S ₁ ), a second illumination step (S ₂ ) is provided, and the illumination time t ₂ of the second illumination step (S ₂ ) is longer than the illumination time t of the first illumination step (S ₁ ). ₁ length is better.

Thereby, it is possible to form a predetermined pretilt angle, and there is an advantage that the burn-in caused by the change of the pretilt angle can be reduced.

In the manufacturing method of the liquid crystal display element of the present invention, it is preferable to perform the irradiation step once or twice. For example, from the viewpoint that only one irradiation device is sufficient, it is preferable to perform the irradiation step once. On the other hand, from the viewpoint of easy control of the pretilt angle of the liquid crystal molecules, it is preferable to perform the irradiation step twice. From the viewpoint of easy control of the pre-tilt angle of the liquid crystal molecules, the embodiment of the above-mentioned two-step irradiating step is more preferable.

In the production method of the present invention, the method of attaching the liquid crystal composition containing the polymerizable compound to the substrate is not particularly limited, and examples include bonding the inside of the unit cell of a pair of (electrode) substrates with a spacer interposed therebetween. A method of injecting a liquid crystal composition containing a polymerizable compound, whereby the liquid crystal composition containing a polymerizable compound is attached to an (electrode) substrate (vacuum injection method); to one of a pair of (electrode) substrates and/or A method of dropping a liquid crystal composition containing a polymerizable compound on two substrates (ODF method) or the like. Moreover, it is preferable to form an electrode layer (including a pixel electrode of a TFT, a common electrode) and an alignment film on the (transparent) support substrate according to the needs of the substrate of the present invention.

The method of dropping the polymerizable compound-containing liquid crystal composition of the present invention is not particularly limited, and is usually performed by, for example, screen printing, offset printing, flexographic printing, inkjet, a droplet discharge device, or a dispenser. As another method, there exist dipping, roll coating, a slit coater, a spinner, etc., and these can be employ|adopted according to the objective.

The substrate of the present invention preferably has an electrode layer for vertical electric field driving or lateral electric field driving. Examples of the electrode layer include transparent conductive materials such as ITO (Indium Tin Oxide), IZO (Indium Zinc Tin Oxide), and IZTO (Indium Zinc Tin Oxide) when the liquid crystal display element is a transmissive type, but not limited to these. . In addition, in the case of a reflection type liquid crystal display element, as the electrode layer, a material that reflects light such as aluminum, etc., is mentioned, but is not limited to these.

As the method of forming the electrode layer on the substrate of the present invention, a conventionally known method can be used. It is preferable that the liquid crystal display element of the embodiment has a pair of transparent substrates facing each other, and at least one of the substrates has the electrode layer formed thereon. In addition, the electrode layer preferably has slits formed in a predetermined pattern (fishbone structure), and a transparent insulating film, a planarization film, etc. may be laminated on the electrode layer. Furthermore, a vertical or horizontal alignment film may be formed on the insulating film or the electrode layer, respectively, as required. The alignment film is preferably an organic polymer film such as a polyimide film, a nylon film, and a polyvinyl alcohol film.

In the present invention, an alignment film may be formed on at least one of the pair of substrates, or it is preferable to use a substrate without an alignment film.

The liquid crystal display element of the present invention preferably has the following: a first support substrate and a second support substrate arranged opposite to each other, a common electrode provided on the first support substrate or the second support substrate, and a common electrode provided on the first support substrate A support substrate or the second support substrate and a pixel electrode having a thin film transistor, and a liquid crystal layer containing a liquid crystal composition disposed between the first support substrate and the second support substrate. An alignment film for controlling the alignment direction of liquid crystal molecules can also be provided on the opposite side of at least one of the first support substrate and/or the second support substrate in contact with the liquid crystal layer as required. Furthermore, the color filter may be appropriately provided on the first support substrate or the second support substrate. A color filter can also be arranged on the pixel electrode and the common electrode. In addition, two polarizing plates may be provided on the outside of the first support substrate or the second support substrate.

The supporting substrate of the present invention can be a flexible transparent material such as glass or plastic (acrylic, polycarbonate, etc.), and is considered to be suitable for a reflective liquid crystal display element, and can also be an opaque material such as a silicon wafer. In addition, a pair of substrates are bonded together by a sealing material such as an epoxy-based thermosetting composition and a sealing material arranged in the surrounding area. In order to maintain the distance between the substrates, for example, glass particles and plastic particles may be arranged therebetween. , granular spacers such as alumina particles, or spacer columns made of resin formed by photolithography.

When the liquid crystal display element of the present invention is driven by a vertical electric field, it is preferable that electrode layers are provided on two substrates of a pair of substrates. More specifically, the vertical electric field drive type liquid crystal display element (VA) of the present invention preferably has the following: a second supporting substrate disposed on the opposite side, a common electrode disposed on the second supporting substrate, a A pixel electrode having a thin film transistor on the first support substrate, and a liquid crystal layer containing a liquid crystal composition disposed between the first support substrate and the second support substrate.

Therefore, one substrate preferably has a supporting substrate, a thin film transistor (TFT), pixel electrodes, wirings (gate lines, data bus lines, Cs electrodes, contact holes, etc.), and the other substrate has a supporting substrate, Common electrodes and color filters are preferred. In addition, a color filter (color filter array) may be provided on the pixel electrode and the common electrode.

When the liquid crystal display element of the present invention is driven by a lateral electric field, it is preferable that an electrode layer is formed on only one of the pair of substrates. Gate lines, data bus lines, Cs electrodes, contact holes, etc.), thin film transistors (TFTs), common electrodes, and pixel electrodes are preferred. In addition, the other substrate preferably has a support substrate and a color filter as required.

In the irradiation step of the present invention, the substrate to which the liquid crystal composition containing the polymerizable compound is attached may be any of the above-mentioned (1st or 2nd) supporting substrate, a transparent substrate, the above-mentioned one substrate, and the above-mentioned other substrate.

The color filter of the present invention can be produced by, for example, a pigment dispersion method, a printing method, an electroplating method, or a dyeing method. Taking the production method of the color filter by the pigment dispersion method as an example to illustrate, the curable coloring composition for the color filter is applied on the transparent substrate, subjected to pattern treatment, and then heated or illuminated. to harden it. By performing this step for three colors of red, green, and blue, respectively, a pixel portion for a color filter can be produced. In addition, pixel electrodes with active elements such as TFTs, thin film diodes, metal-insulator-metal resistivity elements, etc., can also be arranged on the substrate.

It is preferable that the said 1st board|substrate and the said 2nd board|substrate oppose so that a common electrode and a pixel electrode layer may become an inner side.

The interval between the first substrate and the second substrate can also be adjusted through a spacer. At this time, it is preferable to adjust so that the thickness of the obtained light-adjusting layer may be 1-100 micrometers. 1.5~10µm is more preferable, and when a polarizing plate is used, it is preferable to adjust the product of the refractive index anisotropy Δn of the liquid crystal and the cell thickness d so that the contrast becomes the maximum. Moreover, when there are two polarizing plates, the polarization axis of each polarizing plate can also be adjusted, so that a viewing angle and a contrast may become favorable. Furthermore, a retardation film for widening the viewing angle can also be used.

The polymerizable compound of the present invention is preferably one or two or more compounds represented by the following general formula (I).

(In the general formula (I), R ²⁰¹ , R ²⁰² , R ²⁰³ , R ²⁰⁴ , R ²⁰⁵ , R ²⁰⁶ , R ²⁰⁷ , R ²⁰⁸ , R ²⁰⁹ and R ²¹⁰ independently represent P ²¹ -S ²¹ -, respectively Any of an alkyl group having 1 to 18 carbon atoms substituted by a fluorine atom, an alkoxy group having 1 to 18 carbon atoms that can also be substituted by a fluorine atom, a fluorine atom or a hydrogen atom, P ²¹ represents a polymerizable group, S ²¹ represents a single bond or an alkylene group having 1 to 15 carbon atoms, and one or more -CH ₂ - in the alkylene group can also pass through -O-, -OCO- in a manner that the oxygen atoms are not directly adjacent to each other. Or -COO-substituted, n ²¹ represents 0, 1 or 2, A ²¹ represents a group selected from the group consisting of the following group (a), group (b) and group (c), (a) 1,4- Cyclohexylene (one -CH ₂ - present in the group or two or more non-adjacent -CH ₂ - may be substituted by -O-), (b) 1,4-phenylene (present in In this group, one -CH= or two or more non-adjacent -CH= may be substituted by -N=), (c) naphthalene-2,6-diyl, 1,2,3,4-tetra Hydronaphthalene-2,6-diyl or decahydronaphthalene-2,6-diyl (exist in naphthalene-2,6-diyl or 1,2,3,4-tetrahydronaphthalene-2,6-diyl Among them, one -CH= or two or more non-adjacent -CH= may also be substituted by -N=), the above-mentioned group (a), group (b) and group (c) can also be independently changed by the number of carbon atoms. 1-12 alkyl groups, 1-12 carbon atoms alkoxy groups, halogens, cyano groups, nitro groups or P ²¹ -S ²¹ - substituted, the above-mentioned general formula (I) has at least one or more in one molecule P ²¹ -S ²¹ -, L ²¹ represents a single bond, -OCH ₂ -, -CH ₂ O-, -C ₂ H ₄ -, -OC ₂ H ₄ O-, -COO-, -OCO-, -CH= CR ^a -COO-, -CH=CR ^a -OCO-, -COO-CR ^a =CH-, -OCO-CR ^a =CH-, -(CH ₂ ) _z -COO-, -(CH ₂ ) _z - OCO-, -OCO-(CH ₂ ) _z -, -COO-(CH ₂ ) _z -, -CH=CH-, -CF ₂ O-, -OCF ₂ - or -C≡C- (wherein R ^a respectively independently represents a hydrogen atom or an alkyl group with 1 to 3 carbon atoms, in the aforementioned formula, z independently represents an integer of 1 to 4), but when P ²¹ , S ²¹ , and A ²¹ exist in plural, they may be the same respectively or different).

As long as it is a polymerizable compound of such a specific structure, the average reaction rate _Vave can be easily controlled to 0.030-0.048 (%/min).

The compound represented by the general formula (I) of the present invention is preferably the polymerizable compound represented by the general formula (IV).

In the above-mentioned general formula (IV), R ⁷ and R ⁸ each independently represent any one of the above-mentioned formulas (R-1) to (R-9), and X ¹ to X ⁸ each independently represent a trifluoromethyl group and a fluorine atom. , a hydrogen atom or an alkoxy group with 1 to 5 carbon atoms.

In the above general formula (IV), it is preferable that R ⁷ and R ⁸ are each independently a methacrylic group or an acrylic group.

The compound represented by the aforementioned general formula (IV) is more preferably one or more selected from the group comprising formula (IV-11) to formula (IV-19), formula (IV-11), Formula (IV-16) and formula (IV-17) are particularly preferred.

The compound represented by the general formula (I) of the present invention is preferably a compound represented by, for example, the formula (XX-1) to the general formula (XX-29), the formula (XX-1) to the formula ( XX-7), formula (XX-14) to formula (XX-29) are further more preferable.

In formula (XX-1) ~ general formula (XX-29), Sp ^xx represents an alkylene group having 1 to 8 carbon atoms or -O-(CH ₂ ) _s - (in the formula, s represents an integer of 1 to 7 , the oxygen atom is set to be bound to the ring).

In formula (XX-1) ~ general formula (XX-29), the hydrogen atom in 1,4-phenylene can also be further processed by -F, -Cl, -CF ₃ , -CH ₃ or P ²¹ -S ²¹ - Either replace.

Moreover, as a compound represented by general formula (I), for example, the polymerizable compound represented by formula (M1) - formula (M18) is preferable.

Moreover, the polymerizable compound of formula (M19) - formula (M34) is also preferable.

The hydrogen atoms in the 1,4-phenylene and naphthyl groups in the formulas (M19) to (M34) may be further substituted by -F, -Cl, -CF ₃ , and -CH ₃ .

Moreover, the compound represented by general formula (I) is also preferably a polymerizable compound represented by formula (M35) to formula (M65).

In the liquid crystal composition containing the polymerizable compound of the present invention, the content of the polymerizable compound represented by the formula (M1) to the formula (M65) with respect to the entire liquid crystal composition is 0.01 to 5 mass %, and the lower limit of the content is 0.02 mass % is better, 0.03 mass % is better, 0.04 mass % is better, 0.05 mass % is better, 0.06 mass % is better, 0.07 mass % is better, 0.08 mass % is better, 0.09 mass % is better, 0.1 mass % is better, 0.15 mass % is better, 0.2 mass % is better, 0.25 mass % is better, 0.3 mass % is better, 0.35 mass % is better, 0.4 mass % is better Mass % is better, 0.5 mass % is better, 0.55 mass % is better, the upper limit of content is preferably 4.5 mass %, 4 mass % is better, 3.5 mass % is better, 3 mass % is better Preferably, 2.5 mass % is better, 2 mass % is better, 1.5 mass % is better, 1 mass % is better, 0.95 mass % is better, 0.9 mass % is better, 0.85 mass % is better Preferably, 0.8 mass % is better, 0.75 mass % is better, 0.7 mass % is better, 0.65 mass % is better, 0.6 mass % is better, 0.55 mass % is better.

Preferred examples of the compound represented by the general formula (I) of the present invention include polymerizable compounds represented by the following formulae (RM-2-1) to (RM-2-52).

In addition, as the specific content of the polymerizable monomers represented by the above formulae (RM-2-1) to (RM-2-52), it is preferably 5 mass % or less, more preferably 3 mass % or less, and 2 It is more preferable that it is less than or equal to 1 mass %, it is especially preferable that it is less than 1 mass %, and it is most preferable that it is less than 0.8 mass %.

When the liquid crystal composition of the present invention is a negative liquid crystal composition, the dielectric constant anisotropy (Δε) at 20°C is -2.0~-8.0, preferably -2.1~-6.2, -2.2~- 5.3 is better, -2.5~-5.0 is further better. -2.7~-4.8 is excellent.

When the liquid crystal composition of the present invention is a positive liquid crystal composition, the dielectric constant anisotropy (Δε) at 20°C is 1.5~20, preferably 1.5~18.0, more preferably 1.5~15.0, and 1.5 ~11 is further better, 1.5~8 is excellent.

The refractive index anisotropy (Δn) of the liquid crystal composition of the present invention at 20° C. is 0.08-0.14, more preferably 0.09-0.13, and particularly preferably 0.09-0.12. More specifically, when it corresponds to a thin unit cell gap, it is preferably 0.10 to 0.13, and when it corresponds to a thick unit cell gap, it is preferably 0.08 to 0.11.

The viscosity (η) of the liquid crystal composition of the present invention at 20°C is 10~50mPa·s, preferably 10~45mPa·s, preferably 10~40mPa·s, preferably 10~35mPa·s, 10~30mPa·s is better, 10~25mPa·s is further better, and 10~22mPa·s is particularly good.

The rotational viscosity (γ ₁ ) of the liquid crystal composition of the present invention is 50~160mPa·s at 20°C, preferably 55~160mPa·s, preferably 60~160mPa·s, and 60~150mPa·s More preferably, 60~140mPa·s is better, 60~130mPa·s is better, 60~125mPa·s is better.

The liquid crystal composition of the present invention has a nematic-isotropic liquid phase transition temperature (T _ni ) of 60°C to 120°C, preferably 70°C to 100°C, and particularly preferably 70°C to 85°C.

The liquid crystal composition of the present invention is based on one or more compounds represented by the general formula (L) containing a compound having an almost neutral dielectric property (the value of Δε is -2 to 2) as the first component. good.

The compound represented by the aforementioned general formula (L) is as follows.

(In the formula, R ^L1 and R ^L2 each independently represent an alkyl group with 1 to 8 carbon atoms, and one of the alkyl groups or two or more non-adjacent -CH ₂ - may also independently pass through -CH=CH -, -C≡C-, -O-, -CO-, -COO- or -OCO- substituted, n ^L1 represents 0, 1, 2 or 3, A ^L1 , A ^L2 and A ^L3 independently represent selected from the group consisting of The group of the following group (a), group (b) and group (c), (a) 1,4-cyclohexylene (1 -CH ₂ - or non-adjacent 2 existing in the group More than one -CH ₂ - may also be substituted by -O-), (b) 1,4-phenylene group (one -CH= present in the group or two or more -CH= not adjacent to each other are also may be substituted by -N=), (c) naphthalene-2,6-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl or decahydronaphthalene-2,6-diyl ( One -CH= in naphthalene-2,6-diyl or 1,2,3,4-tetrahydronaphthalene-2,6-diyl or two or more non-adjacent -CH= can also be -N=substituted), the above-mentioned groups (a), (b) and (c) can also be independently substituted by cyano, fluorine or chlorine atoms, Z ^L1 and Z ^L2 independently represent a single bond, -CH ₂ CH ₂ -, -(CH ₂ ) ₄ -, -OCH ₂ -, -CH ₂ O-, -COO-, -OCO-, -OCF ₂ -, -CF ₂ O-, -CH=NN=CH-, -CH=CH-, -CF=CF- or -C≡C-, when n ^L1 is 2 or 3 and A ^L2 complex exists, these may be the same or different, when n ^L1 is 2 or 3 and Z ^L2 When plural, these may be the same or different).

The liquid crystal composition of the present invention is composed of a compound represented by the general formula (J) containing a compound having a positive dielectric property (Δε greater than 2) and/or a compound having a negative dielectric property (the sign of Δε is negative and Its absolute value is greater than 2) It is preferable that one or two or more kinds are used as the second component.

The compound represented by the aforementioned general formula (J) is as follows.

(In the formula, R ^J1 represents an alkyl group with 1 to 8 carbon atoms, and one of the alkyl groups or two or more non-adjacent -CH ₂ - may also independently pass through -CH=CH-, -C≡ C-, -O-, -CO-, -COO- or -OCO- substituted, n ^J1 represents 0, 1, 2, 3 or 4, A ^J1 , A ^J2 and A ^J3 independently represent a group selected from the group consisting of the following groups: (a), the group of the group (b) and the group (c), (a) 1,4-cyclohexylene (one -CH ₂ - present in the group or two or more non-adjacent groups) -CH ₂ - may also be substituted by -O-), (b) 1,4-phenylene (one -CH= present in the group or two or more non-adjacent -CH= may also be replaced by - N=substituted), (c) naphthalene-2,6-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl or decahydronaphthalene-2,6-diyl (existing in naphthalene One -CH= in -2,6-diyl or 1,2,3,4-tetrahydronaphthalene-2,6-diyl or two or more non-adjacent -CH= can also be passed through -N= substituted), the above-mentioned group (a), group (b) and group (c) can also be independently substituted by cyano group, fluorine atom, chlorine atom, methyl group, trifluoromethyl group or trifluoromethoxy group, Z ^J1 and Z ^J2 independently represents a single bond, -CH ₂ CH ₂ -, -(CH ₂ ) ₄ -, -OCH ₂ -, -CH ₂ O-, -OCF ₂ -, -CF ₂ O-, -COO-, - OCO- or -C≡C-, when n ^J1 is 2, 3 or 4 and A ^J2 complex exists, these may be the same or different, when n ^J1 is 2, 3 or 4 and Z ^J1 complex exists, this etc. may be the same or different, X ^J1 represents a hydrogen atom, a fluorine atom, a chlorine atom, a cyano group, a trifluoromethyl group, a fluoromethoxy group, a difluoromethoxy group, a trifluoromethoxy group or a 2,2,2- trifluoroethyl).

One or more selected from the group consisting of compounds represented by the aforementioned general formulae (N-1) to (N-3) are as follows.

(In the above formula, R ^N11 , R ^N12 , R ^N21 , R ^N22 , R ^N31 and R ^N32 each independently represent an alkyl group with 1 to 8 carbon atoms, and one of the alkyl groups or two or more non-adjacent ones -CH ₂ - can also be independently substituted by -CH=CH-, -C≡C-, -O-, -CO-, -COO- or -OCO-, A ^N11 , A ^N12 , A ^N21 , A ^N22 , A ^N31 and A ^N32 each independently represent a group selected from the group consisting of the following group (a), group (b), group (c) and group (d), (a) 1,4-cyclohexylene (existing One -CH ₂ - in the group or two or more -CH ₂ - not adjacent to each other may also be substituted by -O-), (b) 1,4-phenylene (1 in the group (c) Naphthalene-2,6-diyl, 1,2,3,4-tetrahydronaphthalene-2, 6-diyl or decahydronaphthalene-2,6-diyl (existing in one of naphthalene-2,6-diyl or 1,2,3,4-tetrahydronaphthalene-2,6-diyl- CH= or two or more non-adjacent -CH= may be substituted by -N=), (d) 1,4-cyclohexenylene group, the above-mentioned group (a), group (b), group (c) And the group (d) can also be independently substituted by a cyano group, a fluorine atom or a chlorine atom, Z ^N11 , Z ^N12 , Z ^N21 , Z ^N22 , Z ^N31 and Z ^N32 respectively independently represent a single bond, -CH ₂ CH ₂ -, -(CH ₂ ) ₄ -, -OCH ₂ -, -CH ₂ O-, -COO-, -OCO-, -OCF ₂ -, -CF ₂ O-, -CH=NN=CH-, -CH=CH -, -CF=CF- or -C≡C-, X ^N21 represents hydrogen atom or fluorine atom, T ^N31 represents -CH ₂ - or oxygen atom, n ^N11 , n ^N12 , n ^N21 , n ^N22 , n ^N31 and n ^N32 independently represents an integer from 0 to 3, but when n ^N11 +n ^N12 , n ^N21 +n ^N22 and n ^N31 +n ^N32 are independently 1, 2 or 3 and A ^N11 ~A ^N32 , Z ^N11 ~Z ^N32 are complex numbers When present, these may be the same or different).

The compound represented by the above general formula (L) is preferably the compound represented by the following formulae (L-1) to (L-13).

(In the formula, R ^L1 and R ^L2 independently represent the same meaning as the general formula (L), A ^L1 and A ^L7 independently represent the same meaning as the general formula (L), and the hydrogen atoms on A ^L1 and A ^L2 They may also be independently substituted by fluorine atoms, Z ^L1 represents the same meaning as Z ^L2 in the general formula (L), and ^XL1 and ^XL2 independently represent a fluorine atom or a hydrogen atom).

The compound represented by the above general formula (J) is preferably the compound represented by the following formulae (M-1) to (M-18).

(In the above formula, X ^M11 ~ X ^M186 independently represent a hydrogen atom or a fluorine atom, and R ^J1 ~R ^J181 independently represent an alkyl group with 1 to 5 carbon atoms, an alkenyl group with 2 to 5 carbon atoms, or a carbon atom number. Alkoxy of 1 to 4, X ^J11 to X ^J181 represent fluorine atom, chlorine atom or OCF ₃ , A ^M81 and A ^M82 independently represent 1,4-cyclohexylene, 1,4-phenylene or the following groups ,

The hydrogen atom on the 1,4-phenylene can also be substituted by a fluorine atom, and W ^M101 to W ^M172 independently represent -CH ₂ - or -O-).

The compound represented by the general formula (J) is preferably the compound represented by the following formulae (K-1) to (K-6).

(In the formula, R ^K11 represents an alkyl group with 1 to 5 carbon atoms, an alkenyl group with 2 to 5 carbon atoms, or an alkoxy group with 1 to 4 carbon atoms, and X ^K11 to X ^K14 independently represent a hydrogen atom or fluorine. atom, Y ^K11 represents a fluorine atom or OCF ₃ ).

(in the formula, R ^K21 represents an alkyl group with 1 to 5 carbon atoms, an alkenyl group with 2 to 5 carbon atoms or an alkoxy group with 1 to 4 carbon atoms, and X ^K21 to X ^K24 independently represent a hydrogen atom or fluorine atom, Y ^K21 represents a fluorine atom or OCF ₃ ).

(In the formula, R ^K31 represents an alkyl group with 1 to 5 carbon atoms, an alkenyl group with 2 to 5 carbon atoms, or an alkoxy group with 1 to 4 carbon atoms, and X ^K31 to X ^K36 independently represent a hydrogen atom or fluorine. atom, Y ^K31 represents a fluorine atom or OCF ₃ ).

(In the formula, R ^K41 represents an alkyl group with 1 to 5 carbon atoms, an alkenyl group with 2 to 5 carbon atoms, or an alkoxy group with 1 to 4 carbon atoms, and X ^K41 to X ^K46 independently represent a hydrogen atom or a fluorine atom. atom, Y ^K41 represents a fluorine atom or OCF ₃ , and Z ^K41 represents -OCH ₂ -, -CH ₂ O-, -OCF ₂ - or -CF ₂ O-).

(In the formula, R ^K51 represents an alkyl group with 1 to 5 carbon atoms, an alkenyl group with 2 to 5 carbon atoms, or an alkoxy group with 1 to 4 carbon atoms, and X ^K51 to X ^K56 independently represent a hydrogen atom or fluorine. atom, Y ^K51 represents a fluorine atom or OCF ₃ , and Z ^K51 represents -OCH ₂ -, -CH ₂ O-, -OCF ₂ - or -CF ₂ O-).

(in the formula, R ^K61 represents an alkyl group with 1 to 5 carbon atoms, an alkenyl group with 2 to 5 carbon atoms, or an alkoxy group with 1 to 4 carbon atoms, and X ^K61 to X ^K68 independently represent a hydrogen atom or a fluorine atom. atom, Y ^K61 represents a fluorine atom or OCF ₃ , and Z ^K61 represents -OCH ₂ -, -CH ₂ O-, -OCF ₂ - or -CF ₂ O-).

As a compound represented by the general formula (N-1) of this invention, the compound group represented by the following general formula (N-1a) - (N-1g) is mentioned.

(wherein, R ^N11 and R ^N12 have the same meanings as R ^N11 and R ^N12 in the general formula (N-1), n ^{Na12 represents 0 or 1, n Nb11 represents} 1 or 2, n ^Nc11 represents 0 or 1, n ^Nd11 represents 1 or 2, n ^Ne11 represents 1 or 2, n ^Nf12 represents 1 or 2, n ^Ng11 represents 1 or 2, A ^Ne11 represents trans-1,4-cyclohexylene or 1,4-phenylene, A ^Ng11 Represents trans-1,4-cyclohexylene, 1,4-cyclohexenylene or 1,4-phenylene, but when n ^Ng11 is 1, A ^Ng11 represents 1,4-cyclohexenylene, When n ^Ng11 is 2, at least one A ^Ng11 represents 1,4-cyclohexenylene, Z ^Ne11 represents a single bond or ethyl extension, but when n ^Ne11 is 1, Z ^Ne11 represents ethyl extension. When n ^{When Ne11} is 2, at least one Z ^Ne11 represents an ethyl group).

The compound represented by the general formula (N-2) of the present invention is preferably a compound selected from the group of compounds represented by the following general formulae (N-2-1) to (N-2-3).

(In the formula, R ^N211 and R ^N212 independently represent the same meanings as R ^N21 and R ^N22 in the general formula (N-2)).

(In the formula, R ^N221 and R ^N222 independently represent the same meanings as R ^N21 and R ^N22 in the general formula (N-2)).

(In the formula, R ^N231 and R ^N232 independently represent the same meanings as R ^N21 and R ^N22 in the general formula (N-2)).

The compound represented by the general formula (N-3) is preferably a compound selected from the compound group represented by the general formula (N-3-2).

(In the formula, R ^N321 and R ^N322 independently represent the same meanings as R ^N31 and R ^N32 in the general formula (N-3)).

When the liquid crystal composition containing the polymerizable compound of the present invention as a whole shows a positive dielectric constant anisotropy, it contains the polymerizable compound represented by the general formula (I), selected from the compounds represented by the general formula (J) One or more of the compounds and the compound represented by the general formula (L) are preferred.

In the entire liquid crystal composition containing the polymerizable compound of the present invention, the upper limit of the ratio of the components consisting only of the compounds represented by the general formula (I), the general formula (J) and the general formula (L) occupies 100% by mass, 99% by mass, 98% by mass, 97% by mass, 96% by mass, 95% by mass, 94% by mass, 93% by mass, 92% by mass, 91% by mass, 90% by mass, 89% by mass, 88 mass %, 87 mass %, 86 mass %, 85 mass %, and 84 mass % are preferable.

In addition, in the entire liquid crystal composition containing the polymerizable compound of the present invention, the ratio of only the components composed of the compounds represented by the general formula (I), the general formula (J) and the general formula (L) is lower than that of the general formula (L). The limit is 78% by mass, 80% by mass, 81% by mass, 83% by mass, 85% by mass, 86% by mass, 87% by mass, 88% by mass, 89% by mass, 90% by mass, 91% by mass, 92% by mass %, 93% by mass, 94% by mass, 95% by mass, 96% by mass, 97% by mass, 98% by mass, and 99% by mass.

When the liquid crystal composition containing the polymerizable compound of the present invention exhibits a negative dielectric constant anisotropy as a whole, the polymerizable compound represented by the general formula (I) is selected from the group consisting of the polymerizable compound represented by the general formula (N-1). The compound is preferably one or two or more compounds, and a compound represented by the general formula (L).

In the entire liquid crystal composition containing the polymerizable compound of the present invention, the ratio of the proportion of the proportion of the components consisting of only the compounds represented by the general formula (I), the general formula (N-1), and the general formula (L) The upper limit is 100% by mass, 99% by mass, 98% by mass, 97% by mass, 96% by mass, 95% by mass, 94% by mass, 93% by mass, 92% by mass, 91% by mass, 90% by mass, 89% by mass Mass %, 88 mass %, 87 mass %, 86 mass %, 85 mass %, and 84 mass % are preferable.

The liquid crystal display element using the liquid crystal composition containing the polymerizable compound of the present invention has the remarkable feature of high-speed response, and furthermore, the tilt angle can be obtained sufficiently, and there is no unreacted polymerizable compound, or the unreacted polymerizable compound is so small that it does not become The problem is that the voltage holding ratio (VHR) is high, so that there is no or sufficient suppression of problems such as poor alignment and poor display. In addition, since the inclination angle and the residual amount of the polymerizable compound can be easily controlled, it is easy to optimize and reduce the energy cost for manufacturing, so it is most suitable for improving production efficiency and stable mass production.

The liquid crystal display element using the liquid crystal composition containing the polymerizable compound of the present invention is especially useful for active matrix driving liquid crystal display elements, and can be used for PSA type, PSVA type, VA type, PS-IPS type or PS-FFS type liquid crystal display element.

[Example]

The following examples are given to further describe the present invention, but the scope of the present invention is not limited to them.

(Manufacturing method of liquid crystal display element)

First, after coating a polyimide alignment film that induces a vertical alignment of a liquid crystal composition containing a polymerizable compound with a cell gap of 3.5 μm, the aforementioned polyimide alignment film is injected into the polyimide alignment film containing a rubbing process by a vacuum injection method. A liquid crystal cell with an ITO substrate is used to make a liquid crystal display element.

(Determination of V _k )

Regarding the liquid crystal cell containing the liquid crystal composition containing the polymerizable compound, the residual amount of the polymerizable compound in the liquid crystal display element [mass %], V _k and V _ave [mass %/min] of the polymerizable compound were calculated from the formula (1) and the formula (2). The method for measuring the residual amount (C _k ) of the polymerizable compound at this time will now be described. First, the liquid crystal display element is decomposed to obtain an acetonitrile solution containing the elution components of the liquid crystal composition, the polymer, and the unreacted polymerizable compound. It was analyzed by high performance liquid chromatography, and the peak area of each component was measured. The amount of the remaining polymerizable compound was determined from the ratio of the peak area of the liquid crystal compound to the peak area of the unreacted polymerizable compound as an index. The residual amount of the polymerizable compound is determined from this value and the amount of the polymerizable compound added initially. The lower limit of detection for this assay is 100 ppm. The illumination conditions and temperature when measuring V _k were carried out under the same conditions as the corresponding illumination steps (S _k ).

The illumination conditions A to D used in the examples and comparative examples are as follows.

Lighting Condition A: Use a high-pressure mercury lamp to illuminate with a filter that cuts off ultraviolet rays below 320 nm. At this time, the illuminance measured under the condition of the center wavelength of 365 nm was 100 mW/cm ² , and the illuminance measured under the condition of the center wavelength of 313 nm was 24 mW/cm ² .

Lighting Condition B: Use a high-pressure mercury lamp to illuminate with a filter that cuts off light below 325 nm. At this time, the illuminance measured under the condition of the center wavelength of 365 nm was 120 mW/cm ² , and the illuminance measured under the condition of the center wavelength of 313 nm was 18 mW/cm ² .

Illumination condition C: Illumination using a fluorescent UV lamp. At this time, the illuminance measured under the condition of the center wavelength of 365 nm was 2 mW/cm ² , and the illuminance measured under the condition of the center wavelength of 313 nm was 3 mW/cm ² .

Lighting Condition D: Illuminated with a fluorescent UV lamp. At this time, the illuminance measured under the condition of the center wavelength of 365 nm was 3 mW/cm ² , and the illuminance measured under the condition of the center wavelength of 313 nm was 0.3 mW/cm ² .

(Measurement of the amount of change in the pretilt angle in the actual manufacturing method of the liquid crystal display element in one irradiation step (when n=1))

In the atmosphere of 25°C, under the above-mentioned lighting conditions A-D, the light was irradiated for the time described in the following table, and the evaluation of display failure (burn-in) due to the change of the pretilt angle was performed. The irradiation time was set until the residual amount of the polymerizable compound was equal to or less than the detection lower limit. First, the pretilt angle of the liquid crystal display element was measured, and it was set as a pretilt angle (initial stage). The liquid crystal display element was irradiated with a backlight for 24 hours while applying a voltage of 30 V at a frequency of 100 Hz. After that, the pretilt angle was measured and set as the pretilt angle (after the test). The value obtained by subtracting the pretilt angle (after the test) from the measured pretilt angle (initial stage) is set as the pretilt angle change amount (= absolute value of the pretilt angle change) [°]. The pretilt angle was measured using OPTIPRO manufactured by SHINTECH.

The closer the pretilt angle change is to 0[°], the lower the possibility of display failure due to the pretilt angle change. sex becomes higher.

(Comparative Examples 1 to 5)

The nematic liquid crystal phase-isotropic transition point (T _NI ) is 74°C, Δn (20°C) is 0.11, Δε (20°C) is -3.2, and γ ₁ (20°C) is 125mPa·s The liquid crystal composition with negative dielectric constant anisotropy was set as liquid crystal composition LC-001. LC-001 is a composition comprising general formulae (L-1), (L-3), (L-10), (N-1c) and (N-1d).

A voltage of 10V was applied at a frequency of 100Hz to a unit cell into which the polymerizable compound-containing liquid crystal composition was injected with 0.3% by weight of the polymerizable compound RM-2 relative to 99.7 parts by mass of the liquid crystal composition LC-001. Comparative Example 1 was prepared by illuminating under the illumination condition A for 15 minutes.

A voltage of 10V was applied at a frequency of 100Hz to a unit cell into which a polymerizable compound-containing liquid crystal composition containing 0.3% by weight of the polymerizable compound RM-3 was injected with respect to 99.7 parts by mass of the liquid crystal composition LC-001. Comparative Example 2 was prepared by illuminating under the illumination condition A for 15 minutes.

A voltage of 10V was applied at a frequency of 100Hz to a unit cell into which a polymerizable compound-containing liquid crystal composition containing 0.3% by weight of the polymerizable compound RM-3 was injected with respect to 99.7 parts by mass of the liquid crystal composition LC-001. Comparative Example 3 was prepared by illuminating under the illumination condition B for 15 minutes.

A voltage of 10V was applied at a frequency of 100Hz to a unit cell into which the polymerizable compound-containing liquid crystal composition was injected with 0.3% by weight of the polymerizable compound RM-4 relative to 99.7 parts by mass of the liquid crystal composition LC-001. The comparative example 4 was prepared by illuminating for 5 minutes under the illumination condition A.

A voltage of 10V was applied at a frequency of 100Hz to a unit cell into which the polymerizable compound-containing liquid crystal composition was injected with 0.3% by weight of the polymerizable compound RM-4 relative to 99.7 parts by mass of the liquid crystal composition LC-001. Comparative Example 5 was prepared by illuminating under the illumination condition B for 15 minutes.

The _Vave of Comparative Example 1 was 0.055 [mass %/min]. The amount of change in the pretilt angle of Comparative Example 1 was 1.1 [°]. From this point of view, it can be seen that the reaction rate of the polymerizable compound of Comparative Example 1 is high, but the amount of change in the pretilt angle is large.

It can be seen that in Comparative Examples 2 to 5, as in Comparative Example 1, the reaction rate of the polymerizable compound is high, but the amount of change in the pretilt angle is large.

(Examples 1 to 6)

A voltage of 10V was applied at a frequency of 100Hz to a unit cell into which a polymerizable compound-containing liquid crystal composition containing 0.3% by weight of the polymerizable compound RM-1 was injected with respect to 99.7 parts by mass of the liquid crystal composition LC-001. The light was irradiated for 30 minutes under the illumination condition A, and Example 1 was produced.

A voltage of 10V was applied at a frequency of 100Hz to a unit cell into which the polymerizable compound-containing liquid crystal composition was injected with 0.3% by weight of the polymerizable compound RM-2 relative to 99.7 parts by mass of the liquid crystal composition LC-001. The light was irradiated under the light condition B for 30 minutes, and Example 2 was produced.

A voltage of 10V was applied at a frequency of 100Hz to a unit cell into which the polymerizable compound-containing liquid crystal composition was injected with 0.3% by weight of the polymerizable compound RM-2 relative to 99.7 parts by mass of the liquid crystal composition LC-001. The light was irradiated for 60 minutes under the illumination condition C, and Example 3 was produced.

A voltage of 10V was applied at a frequency of 100Hz to a unit cell into which a polymerizable compound-containing liquid crystal composition containing 0.3% by weight of the polymerizable compound RM-3 was injected with respect to 99.7 parts by mass of the liquid crystal composition LC-001. The light was irradiated for 30 minutes under the light condition C, and Example 4 was produced.

A voltage of 10V was applied at a frequency of 100Hz to a unit cell into which the polymerizable compound-containing liquid crystal composition was injected with 0.3% by weight of the polymerizable compound RM-4 relative to 99.7 parts by mass of the liquid crystal composition LC-001. The light was irradiated for 30 minutes under the illumination condition C, and Example 5 was produced.

A voltage of 10V was applied at a frequency of 100Hz to a unit cell into which the polymerizable compound-containing liquid crystal composition was injected with 0.3% by weight of the polymerizable compound RM-4 relative to 99.7 parts by mass of the liquid crystal composition LC-001. The light was irradiated for 60 minutes under the illumination condition D, and Example 6 was produced.

The V _ave of Example 1 was 0.042 [mass %/min]. The pretilt angle change amount of Example 1 was 0.3 [°]. From this point of view, it can be seen that the reaction rate of the polymerizable compound of Example 1 is moderately fast, and the amount of change in the pretilt angle is small.

It can be seen that in Examples 2 to 6, as in Example 1, the reaction rate of the polymerizable compound is moderately fast, and the amount of change in the pretilt angle is small. In addition, it was confirmed that Examples 1 to 6 provided sufficient pretilt angles, sufficiently high-speed response, and sufficiently high VHR. The measurement conditions of the response speed were Von was 6V, Voff was 1V, and the measurement temperature was 25°C, and the measurement apparatus used DMS703 from AUTRONIC-MELCHERS.

(Measurement of the amount of change in the pretilt angle in the actual manufacturing method of the liquid crystal display element in the second illumination step (when n=2))

In the atmosphere of 25°C, after the first irradiation was performed while applying a voltage, the second irradiation was performed without applying a voltage. The lighting conditions and lighting time of the first and second lighting steps are shown in the following table. The irradiation time was set until the residual amount of the polymerizable compound was equal to or less than the detection lower limit. Next, evaluation of display failure (burn-in) due to changes in the pretilt angle was performed. First, the pretilt angle of the liquid crystal display element was measured, and it was set as a pretilt angle (initial stage). The liquid crystal display element was irradiated with a backlight for 24 hours while applying a voltage of 30 V at a frequency of 100 Hz. After that, the pretilt angle was measured and set as the pretilt angle (after the test). The value obtained by subtracting the pretilt angle (after the test) from the measured pretilt angle (initial stage) is set as the pretilt angle change amount (= absolute value of the pretilt angle change) [°]. The pretilt angle was measured using OPTIPRO manufactured by SHINTECH.

The closer the pretilt angle change is to 0[°], the lower the possibility of display failure due to the pretilt angle change. sex becomes higher.

(Comparative Example 6)

A voltage of 10V was applied at a frequency of 100Hz to a unit cell into which a polymerizable compound-containing liquid crystal composition containing 0.3% by weight of the polymerizable compound RM-3 was injected with respect to 99.7 parts by mass of the liquid crystal composition LC-001. Comparative Example 6 was prepared by irradiating ultraviolet rays under the ultraviolet irradiation condition B for 600 seconds, and thereafter under the irradiation condition C for 5 minutes.

It can be seen that in Comparative Example 6, as in Comparative Example 1, the reaction rate of the polymerizable compound is high, but the amount of change in the pretilt angle is large.

(Examples 7 to 13)

A voltage of 10V was applied at a frequency of 100Hz to a unit cell into which the polymerizable compound-containing liquid crystal composition was injected with 0.3% by weight of the polymerizable compound RM-2 relative to 99.7 parts by mass of the liquid crystal composition LC-001. The light was irradiated under the illumination condition B for 1.25 minutes, and thereafter, the light was illuminated under the illumination condition C for 60 minutes, and Example 7 was prepared.

A voltage of 10V was applied at a frequency of 100Hz to a unit cell into which the polymerizable compound-containing liquid crystal composition was injected with 0.3% by weight of the polymerizable compound RM-2 relative to 99.7 parts by mass of the liquid crystal composition LC-001. The light was irradiated under the illumination condition B for 2.5 minutes, and thereafter, the light was illuminated under the illumination condition C for 50 minutes, and Example 8 was prepared.

A voltage of 10V was applied at a frequency of 100Hz to a unit cell into which the polymerizable compound-containing liquid crystal composition was injected with 0.3% by weight of the polymerizable compound RM-2 relative to 99.7 parts by mass of the liquid crystal composition LC-001. The light was irradiated under the illumination condition B for 5 minutes, and thereafter, the light was illuminated under the illumination condition C for 45 minutes, and Example 9 was prepared.

A voltage of 10V was applied at a frequency of 100Hz to a unit cell into which the polymerizable compound-containing liquid crystal composition was injected with 0.3% by weight of the polymerizable compound RM-2 relative to 99.7 parts by mass of the liquid crystal composition LC-001. The light was irradiated under the irradiation condition B for 10 minutes, and thereafter, the light was irradiated under the irradiation condition C for 30 minutes to prepare Example 10.

A voltage of 10V was applied at a frequency of 100Hz to a unit cell into which a polymerizable compound-containing liquid crystal composition containing 0.3% by weight of the polymerizable compound RM-3 was injected with respect to 99.7 parts by mass of the liquid crystal composition LC-001. The light was irradiated under the irradiation condition B for 1.25 minutes, and thereafter, the light was irradiated under the irradiation condition C for 30 minutes to prepare Example 11.

A voltage of 10V was applied at a frequency of 100Hz to a unit cell into which a polymerizable compound-containing liquid crystal composition containing 0.3% by weight of the polymerizable compound RM-3 was injected with respect to 99.7 parts by mass of the liquid crystal composition LC-001. The light was irradiated under the illumination condition B for 2.5 minutes, and thereafter, the light was illuminated under the illumination condition C for 20 minutes to prepare Example 12.

A voltage of 10V was applied at a frequency of 100Hz to a unit cell into which a polymerizable compound-containing liquid crystal composition containing 0.3% by weight of the polymerizable compound RM-3 was injected with respect to 99.7 parts by mass of the liquid crystal composition LC-001. The light was irradiated under the irradiation condition B for 5 minutes, and thereafter, the light was irradiated under the irradiation condition C for 10 minutes to prepare Example 13.

It can be seen that in Examples 7 to 13, as in Example 1, the reaction rate of the polymerizable compound is moderately fast, and the amount of change in the pretilt angle is small.

In addition, it was confirmed that Examples 7 to 13 provided a sufficient pretilt angle, sufficiently high-speed response, and sufficiently high VHR. The measurement conditions of the response speed were Von was 6V, Voff was 1V, and the measurement temperature was 25°C, and the measurement apparatus used DMS703 from AUTRONIC-MELCHERS.

(Relationship between voltage holding ratio VHR and illumination time)

In order to confirm the relationship between VHR and irradiation time, the liquid crystal display element was evaluated by one irradiation step. The evaluation method will be described below. After heating at 120°C for 1 hour, light was irradiated under the atmosphere of 25°C under the conditions described in the table below, and the VHR was measured. The measurement conditions of the VHR were 1V, 0.6 Hz, and 60°C.

(Comparative Example 7, Examples 14 to 16)

A voltage of 10V was applied at a frequency of 100Hz to a unit cell into which a polymerizable compound-containing liquid crystal composition containing 0.3% by weight of the polymerizable compound RM-1 was injected with respect to 99.7 parts by mass of the liquid crystal composition LC-001. Comparative Example 7 was prepared by irradiating light for 90 minutes under the lighting condition C.

A voltage of 10V was applied at a frequency of 100Hz to a unit cell in which a polymerizable compound-containing liquid crystal composition containing 0.3% by weight of the polymerizable compound RM-2 was injected with respect to 99.7 parts by mass of the liquid crystal composition LC-001. The light was irradiated for 60 minutes under the illumination condition C, and Example 14 was produced.

A voltage of 10V was applied at a frequency of 100Hz to a unit cell into which a polymerizable compound-containing liquid crystal composition containing 0.3% by weight of the polymerizable compound RM-3 was injected with respect to 99.7 parts by mass of the liquid crystal composition LC-001. The light was irradiated under the illumination condition C for 30 minutes, and Example 15 was produced.

A voltage of 10V was applied at a frequency of 100Hz to a unit cell in which a polymerizable compound-containing liquid crystal composition containing 0.3% by weight of the polymerizable compound RM-4 was injected with respect to 99.7 parts by mass of the liquid crystal composition LC-001. The light was irradiated under the illumination condition C for 30 minutes, and Example 16 was produced.

The _Vave of Comparative Example 7 was 0.029 [mass %/min]. The amount of change in the pretilt angle of Comparative Example 1 was 0.1 [°]. The VHR after ultraviolet irradiation of Comparative Example 1 was 71 [%].

The V _ave of Example 14 was 0.034 [mass %/min]. The pretilt angle change amount of Example 14 was 0.2 [°]. The VHR after ultraviolet irradiation of Example 14 was 76 [%].

The _Vave of Example 15 was 0.041 [mass %/min]. The pretilt angle change amount of Example 15 was 0.1 [°]. The VHR after ultraviolet irradiation of Example 15 was 79 [%].

The _Vave of Example 16 was 0.047 [mass %/min]. The pretilt angle change amount of Example 16 was 0.2 [°]. The VHR after ultraviolet irradiation of Example 16 was 80 [%].

FIG. 1 shows a graph of the ultraviolet irradiation time and VHR of Comparative Example 7 and Examples 14 to 16.

From the graph shown in FIG. 1 , it can be seen that the larger the V _ave , the higher the VHR is, and if the V _ave becomes less than 0.030 (mass %/min), the VHR will be saturated at a low value. From this, it can be seen that when the _Vave is appropriately large, the residual amount of the polymerizable compound becomes equal to or less than the detection lower limit in a short irradiation time, so that deterioration of the liquid crystal composition due to light and the like hardly occur.

Claims (9)

A method for manufacturing a liquid crystal display element, which is independently provided with an irradiation step of irradiating a liquid crystal composition containing a polymerizable compound attached to a substrate 1 to n times with light having a peak at 300 to 400 nm. The method is characterized in that: when the liquid crystal composition containing 0.3 mass % of the polymerizable compound is irradiated for 5 minutes under the illumination conditions of the k-th illuminating step (S _k ) in the 1-n illuminating steps When the concentration (C _k ) of the polymerizable compound and the concentration change V _k per unit minute of the difference from the concentration of 0.3 mass % are represented by the following formula (1) for each step, the following formula (2) The average reaction rate Vave of the polymerizable compound in the shown full illumination step ( _{ΣS k} ) is controlled to be 0.030 to 0.048 (mass %/min); including the polymerizable compound represented by the following general formula (I) and One or more compounds selected from the group of polymerizable compounds represented by formula (RM-2-1) to formula (RM-2-52) are used as the polymerizable compound;

(In the above formula (1), C _k represents the liquid crystal composition contained in the liquid crystal composition containing 0.3 mass % of the polymerizable compound after being irradiated for 5 minutes under the illumination conditions of the k-th illumination step (S _k ). The concentration (mass %) of the polymerizable compound, in the above formula (2), V _k is represented by the above formula (1), and t _k represents the irradiation time (minutes) for the polymerizable compound to be irradiated in the k-th irradiation step); The polymerizable compound represented by the general formula (I):

(In the general formula (I), R ²⁰¹ , R ²⁰² , R ²⁰³ , R ²⁰⁴ , R ²⁰⁵ , R ²⁰⁶ , R ²⁰⁷ , R ²⁰⁸ , R ²⁰⁹ and R ²¹⁰ independently represent P ²¹ -S ²¹ -, respectively Any of an alkyl group having 1 to 18 carbon atoms substituted by a fluorine atom, an alkoxy group having 1 to 18 carbon atoms that can also be substituted by a fluorine atom, a fluorine atom or a hydrogen atom, P ²¹ represents a polymerizable group, S ²¹ represents a single bond or an alkylene group having 1 to 15 carbon atoms, and one or more -CH ₂ - in the alkylene group can also pass through -O-, -OCO- in a manner that the oxygen atoms are not directly adjacent to each other. Or -COO-substituted, n ²¹ represents 0, 1 or 2, A ²¹ represents a group selected from the group consisting of the following group (a), group (b) and group (c), (a) 1,4- Cyclohexylene (one -CH ₂ - or two or more non-adjacent -CH ₂ - present in the group may be substituted by -O-), (b) 1,4-phenylene (present in In this group, one -CH= or two or more non-adjacent -CH= may be substituted by -N=), (c) naphthalene-2,6-diyl, 1,2,3,4-tetra Hydronaphthalene-2,6-diyl or decahydronaphthalene-2,6-diyl (exist in naphthalene-2,6-diyl or 1,2,3,4-tetrahydronaphthalene-2,6-diyl Among them, one -CH= or two or more non-adjacent -CH= may also be substituted by -N=), the above-mentioned group (a), group (b) and group (c) can also be independently changed by the number of carbon atoms. 1-12 alkyl groups, 1-12 carbon atoms alkoxy groups, halogens, cyano groups, nitro groups or P ²¹ -S ²¹ - substituted, the above-mentioned general formula (I) has at least one or more in one molecule P ²¹ -S ²¹ -, L ²¹ represents a single bond, -OCH ₂ -, -CH ₂ O-, -C ₂ H ₄ -, -OC ₂ H ₄ O-, -COO-, -OCO-, -CH= CR ^a -COO-, -CH=CR ^a -OCO-, -COO-CR ^a =CH-, -OCO-CR ^a =CH-, -(CH ₂ ) _z -COO-, -(CH ₂ ) _z - OCO-, -OCO-(CH ₂ ) _z -, -COO-(CH ₂ ) _z -, -CH=CH-, -CF ₂ O-, -OCF ₂ - or -C≡C- (wherein R ^a respectively independently represents a hydrogen atom or an alkyl group with 1 to 3 carbon atoms, in this formula, z respectively independently represents an integer of 1 to 4), but when P ²¹ , S ²¹ , and A ²¹ exist in plural, they can be respectively the same or different); polymerizable compounds represented by formula (RM-2-1) ~ formula (RM-2-52):

The method for producing a liquid crystal display element according to claim 1, wherein in at least one irradiation step (S _k ), light is applied in a state where a voltage is applied. The method for producing a liquid crystal display element according to claim 1, which is a method for producing a liquid crystal display element including an irradiation step of irradiating a liquid crystal composition containing a polymerizable compound attached to a substrate with light having a peak at 300 to 400 nm once. , wherein, under the illumination conditions of the first illumination step (S ₁ ), the concentration of the polymerizable compound (C ₁ ) after illuminating the liquid crystal composition containing 0.3% by mass of the polymerizable compound for 5 minutes, and When the concentration change V ₁ per unit minute with the concentration difference of 0.3 mass % is represented by the following formula (1-1), the first irradiation step (S ₁ ) represented by the following formula (2-1) ) in the average reaction rate V _ave of the polymerizable compound is controlled to be 0.030 ~ 0.048 (mass %/min);

(In the above formula (1-1), C ₁ represents the concentration (mass %) of the polymerizable compound contained in the liquid crystal composition after 5 minutes under the illumination conditions of the first illumination step (S ₁ ), and the above formula In (2-1), V ₁ is represented by the above formula (1-1), and t ₁ represents the irradiation time (minutes) for irradiating the polymerizable compound in the first irradiation step (S ₁ ). The method for producing a liquid crystal display element according to claim 1, which is a liquid crystal display element independently including twice the irradiation step of irradiating the liquid crystal composition containing the polymerizable compound attached to the substrate with light having a peak at 300 to 400 nm The manufacturing method, wherein, when the liquid crystal composition containing 0.3 mass % of the polymerizable compound is irradiated for 5 minutes under the lighting conditions of the first irradiation step (S ₁ ), the concentration of the polymerizable compound (C _{1 )} ), and the concentration change V ₁ per unit minute of the concentration difference with 0.3 mass % is represented by the following formula (1-1). For the liquid crystal composition containing 0.3 mass % of the polymerizable compound, the second The concentration (C ₂ ) of the polymerizable compound after illuminating for 5 minutes under the illuminating conditions of the illuminating step (S ₂ ), and the concentration change V ₂ per unit minute of the concentration difference from 0.3 mass % are expressed by the following formula (1 When represented by -2), the average reaction rate _Vave of the polymerizable compound represented by the following formula (2-2) is controlled to be 0.030 to 0.048 (mass %/min);

(In the above formulas (1-1) and (1-2), C ₁ represents that the liquid crystal composition containing 0.3 mass % of the polymerizable compound is irradiated for 5 minutes under the lighting conditions of the first irradiation step (S ₁ ) After that, the concentration (mass %) of the polymerizable compound, C ₂ represents the polymerization after 5 minutes of irradiation with the liquid crystal composition containing 0.3 mass % of the polymerizable compound under the lighting conditions of the second irradiation step (S ₂ ). The concentration (mass %) of the chemical compound, in the above formula (2-2), V ₁ and V ₂ represent the concentration change amount per unit minute shown by the above formula (1-1) and formula (1-2), t ₁ and t ₂ represent the irradiation time (minutes) for irradiating the polymerizable compound in each step. The method for producing a liquid crystal display element according to claim 3, wherein in the first irradiation step (S ₁ ), light having a peak at 300 to 400 nm is irradiated in a state where a voltage is applied. The method for producing a liquid crystal display element according to claim 4, wherein, in the first irradiating step (S ₁ ), light having a peak at 300 to 400 nm is irradiated in a state where a voltage is applied. The method for manufacturing a liquid crystal display element according to claim 4, wherein after the first illuminating step (S ₁ ), the second illuminating step (S ₂ ) is provided, and the second illuminating step (S ₂ ) has an irradiation time t ₂ is longer than the irradiation time t ₁ of the first irradiation step (S ₁ ). The method for manufacturing a liquid crystal display element according to claim 5, wherein after the first illuminating step (S ₁ ), the second illuminating step (S ₂ ) is provided, and the second illuminating step (S ₂ ) has an irradiation time t ₂ is longer than the irradiation time t ₁ of the first irradiation step (S ₁ ). The method for manufacturing a liquid crystal display element according to claim 6, wherein after the first illuminating step (S ₁ ), the second illuminating step (S ₂ ) is provided, and the second illuminating step (S ₂ ) has an irradiation time t ₂ is longer than the irradiation time t ₁ of the first irradiation step (S ₁ ).

Images