Liquid crystal composition and liquid crystal element

Abstract

This liquid crystal composition comprises a polymerizable organic compound and a liquid crystal compound, wherein the specific resistance value of said liquid crystal composition is at least 1×10-11 Ω∙m and less than 1×10-5 Ω∙m. This liquid crystal element comprises: a planar first substrate; a first conductive film disposed on one surface of the first substrate and having conductivity; a liquid crystal layer disposed on the reverse side of the first conductive film from the first substrate and having a liquid crystal composition; a second conductive film disposed on the reverse side of the liquid crystal layer from the first conductive film and having conductivity; and a planar second substrate disposed on the reverse side of the second conductive film from the liquid crystal layer, wherein the liquid crystal composition contains a polymerizable organic compound and a liquid crystal compound, and the specific resistance value of the liquid crystal composition is at least 1×10-11 Ω∙m and less than 1×10-5 Ω∙m.

Description

Liquid crystal composition and liquid crystal device

[0001] The present invention relates to a liquid crystal composition and a liquid crystal device, and more particularly to a liquid crystal composition used in, for example, a liquid crystal display, and a liquid crystal device using the liquid crystal composition of the present invention.

[0002] 2. Description of the Related Art Liquid crystal elements such as liquid crystal display panels are used in a variety of household electrical appliances, measuring instruments, automotive panels, word processors, electronic organizers, printers, computers, televisions, and the like.

[0003] A liquid crystal element is composed of a liquid crystal layer sealed between a pair of glass substrates. The glass substrates are provided with electrodes for applying an electric field to the liquid crystal layer. Controlling this electric field changes the orientation of the liquid crystal molecules contained in the liquid crystal layer, thereby displaying an image. The material that constitutes this liquid crystal layer is a liquid crystal composition, and various liquid crystal compositions have been proposed.

[0004] For example, Patent Document 1 describes a liquid crystal composition containing two or more compounds having two to four ring structures between two side chains, one or more ring structures being a 2,3-difluorobenzene skeleton, and two side chains being linked to different ring structures, in which the positions of the 2,3-difluorobenzene skeletons are different and the number of ring structures is the same.

[0005] Here, the number of ring structures is N, and when the molecular weights of the two side chains are different, the position of the ring structure to which the side chain with a larger molecular weight is linked is defined as 1, and the position of the ring structure to which the side chain with a smaller molecular weight is linked is defined as N, and consecutive numbers are assigned in order from 1 to N, including the ring structures in between, and when the molecular weights of the two side chains are the same, the position of the ring structure to which the side chains are linked is defined as 1, and the position of the ring structure to which no side chains are linked is defined as 2. Such a liquid crystal composition exhibits the effects of having a low crystallization temperature and excellent compatibility.

[0006] Japanese Patent Application Laid-Open No. 2016-27165

[0007] Incidentally, a liquid crystal element having a ferroelectric liquid crystal composition as described in Patent Document 1 can achieve a response speed 10 times or more faster than that of a liquid crystal element having a nematic liquid crystal. However, in order to drive a thin film transistor using a ferroelectric liquid crystal composition, a liquid crystal material having a high specific resistance is indispensable.

[0008] The specific resistance of the liquid crystal composition described in Patent Document 1 is 10 １１ Ω cm or more, i.e., 10 ９ Such a high specific resistance value, which is Ω·m or more, increases hysteresis, causing display delays and response problems in the liquid crystal element, and also deteriorating contrast.

[0009] The present invention has been made in view of the above points, and aims to provide a liquid crystal composition that enables the production of a liquid crystal element having good response and contrast, and a liquid crystal element having good response and contrast.

[0010] In order to achieve the above object, the inventors have conducted extensive research and have found that the specific resistance of a conventional liquid crystal composition is 10 ９ The present inventors have found that when a liquid crystal composition having a resistivity that is very low compared to a value of Ω·m or more and a resistivity value within a specific range is used in a liquid crystal element, the response and contrast become good, and have completed the present invention. That is, in order to achieve the above object, the liquid crystal composition of the present invention is a liquid crystal composition containing a polymerizable organic compound and a liquid crystal compound, and the resistivity of the liquid crystal composition is 1×10 －１１ Ω・m or more 1×10 －５ It is less than Ω·m.

[0011] Here, the specific resistance of the liquid crystal composition is 1×10 －１１ Ω・m or more 1×10 －５ When the resistivity of the liquid crystal composition is less than Ω·m, hysteresis in the liquid crystal element can be suppressed. －１１ Ω・m or more 1×10 －５ When the resistivity is less than Ω·m, the liquid crystal alignment property can be improved.

[0012] The liquid crystal composition of the present invention may also contain at least one additive compound selected from the group consisting of piperidine compounds, phosphate compounds, and halogen compounds.

[0013] In this case, at least one additive compound selected from a piperidine compound, a phosphoric acid compound, and a halogen compound is mixed with the organic compound and the liquid crystal compound to induce ionic conduction and increase the specific resistance of the liquid crystal composition to 1×10 －１１ Ω・m or more 1×10 －５ Easy to adjust to less than Ω·m.

[0014] In the liquid crystal composition of the present invention, the content of the additive compound may be 0.2 to 17% by mass based on the total amount of the liquid crystal composition.

[0015] In this case, the specific resistance of the liquid crystal composition is 1×10 －１１ Ω・m or more 1×10 －５ It is even easier to adjust to less than Ω·m.

[0016] In the liquid crystal composition of the present invention, the specific resistance of the liquid crystal composition is 1×10 －９ Ω・m or more 1×10 －７ It is possible to configure the resistance to be less than Ω·m.

[0017] In this case, hysteresis in the liquid crystal element can be particularly suppressed, and the liquid crystal alignment property can be particularly improved.

[0018] In the liquid crystal composition of the present invention, the content of the additive compound may be 5.0 to 14.0% by mass based on the total amount of the liquid crystal composition.

[0019] In this case, the specific resistance of the liquid crystal composition is 1×10 －９ Ω・m or more 1×10 －７ Easy to adjust to less than Ω·m.

[0020] In the liquid crystal composition of the present invention, the additive compound may be ethyl piperidine-4-carboxylate, and the content of the additive compound may be 5.0 to 13.0% by mass based on the total mass of the liquid crystal composition.

[0021] In this case, the specific resistance of the liquid crystal composition is 1×10－９ Ω・m or more 1×10 －７ This makes it easier to adjust the resistance to less than Ω·m, and it is possible to particularly suppress hysteresis in the liquid crystal element and particularly improve the liquid crystal alignment property.

[0022] In order to achieve the above object, a liquid crystal element of the present invention includes a planar first substrate, a first conductive film that is disposed on one surface of the first substrate and has conductivity, a liquid crystal layer that is disposed on the side of the first conductive film opposite the first substrate and has a liquid crystal composition, a second conductive film that is disposed on the side of the liquid crystal layer opposite the first conductive film and has conductivity, and a planar second substrate that is disposed on the side of the second conductive film opposite the liquid crystal layer, wherein the liquid crystal composition contains a polymerizable organic compound and a liquid crystal compound, and the liquid crystal composition has a specific resistance of 1×10 －１１ Ω・m or more 1×10 －５ It is less than Ω·m.

[0023] Here, the specific resistance of the liquid crystal composition is 1×10 －１１ Ω・m or more 1×10 －５ When the resistivity of the liquid crystal composition is less than Ω·m, hysteresis in the liquid crystal element can be suppressed. －１１ Ω・m or more 1×10 －５ When the resistivity is less than Ω·m, the liquid crystal alignment property can be improved.

[0024] The liquid crystal composition of the present invention can realize the production of a liquid crystal device having good response and contrast. The liquid crystal device of the present invention has good response and contrast.

[0025] FIG. 1 is a schematic cross-sectional view showing an example of a liquid crystal element to which the present invention is applied. FIG. 2 is a schematic view showing an example of an apparatus for measuring the drive response of a liquid crystal element. FIG. 3 is a schematic view showing a hysteresis curve of a liquid crystal element to which the present invention is applied (Example 1). FIG. 4 is a schematic view showing a hysteresis curve of a liquid crystal element to which the present invention is applied (Example 2). FIG. 5 is a schematic view showing a hysteresis curve of a liquid crystal element to which the present invention is applied (Example 4). FIG. 6 is a schematic view showing a hysteresis curve of a liquid crystal element to which the present invention is applied (Example 5). FIG. 7 is a schematic view showing a hysteresis curve of a liquid crystal element to which the present invention is applied (Example 7). FIG. 8 is a schematic view showing a hysteresis curve of a conventional liquid crystal element (Comparative Example 2). FIG. 9 is a schematic view showing a hysteresis curve of a liquid crystal element to which the present invention is applied (Example 9). 1A and 1B are schematic diagrams showing hysteresis curves of a liquid crystal element to which the present invention is applied (Example 10), a conventional liquid crystal element (Comparative Example 3), and a conventional liquid crystal element (Comparative Example 4).

[0026] The liquid crystal composition of the present invention contains a polymerizable organic compound and a liquid crystal compound. The liquid crystal composition of the present invention has a specific resistance of 1×10 －１１ Ω・m or more 1×10 －５ less than Ω·m, preferably 1×10 －１０ Ω・m or more 1×10 －６ Less than Ω·m, most preferably 1×10 －９ Ω・m or more 1×10 －７ It can be less than Ω·m.

[0027] The liquid crystal composition of the present invention has a specific resistance of 1×10 －１１ Ω・m or more 1×10 －５ Since the resistance is less than Ω·m, the hysteresis in the liquid crystal element of the present invention to which the liquid crystal composition of the present invention is applied can be suppressed, and the liquid crystal alignment property can be improved.

[0028] Furthermore, the liquid crystal composition of the present invention has a specific resistance of 1×10－９ Ω・m or more 1×10 －７ If it is less than Ω·m, the hysteresis in the liquid crystal element of the present invention to which the liquid crystal composition of the present invention is applied can be particularly suppressed, and the liquid crystal alignment property can be particularly improved.

[0029] Here, the organic compound contained in the liquid crystal composition of the present invention has a specific resistance of 1×10 －９ Ω・m or more 1×10 －７ The organic compound contained in the liquid crystal composition of the present invention is not particularly limited as long as it can be adjusted to less than Ω·m and is polymerizable. Specific examples of the organic compound contained in the liquid crystal composition of the present invention include a monofunctional acrylate ester monomer, a monofunctional acrylate ester oligomer, a monofunctional acrylate ester polymer, a monofunctional methacrylate ester monomer, a monofunctional methacrylate ester oligomer, a monofunctional methacrylate ester polymer, a di- to pentafunctional acrylate ester monomer, a di- to pentafunctional acrylate ester oligomer, a di- to pentafunctional acrylate ester polymer, a di- to pentafunctional methacrylate ester monomer, a di- to pentafunctional methacrylate ester oligomer, a di- to pentafunctional methacrylate ester polymer, a urethane acrylate ester monomer, a urethane acrylate ester oligomer, a urethane acrylate ester polymer, a urethane methacrylate ester monomer, a urethane methacrylate ester oligomer, a urethane methacrylate ester oligomer, a urethane methacrylate ester The epoxy ester monomer is at least one selected from the group consisting of vinyl acrylate ester polymers, polyester acrylate monomers, polyester acrylate oligomers, polyester acrylate polymers, polyester methacrylate monomers, polyester methacrylate oligomers, polyester methacrylate polymers, vinyl acrylate ester monomers, vinyl acrylate ester oligomers, vinyl acrylate ester polymers, vinyl methacrylate ester monomers, vinyl methacrylate ester oligomers, vinyl methacrylate ester polymers, epoxy ester acrylate monomers, epoxy ester acrylate oligomers, epoxy ester acrylate polymers, epoxy ester methacrylate monomers, epoxy ester methacrylate oligomers, and epoxy ester methacrylate polymers.

[0030] The content of the polymerizable organic compound contained in the liquid crystal composition of the present invention is specifically, for example, 10 to 75% by mass based on the total amount of the liquid crystal composition of the present invention.

[0031] Furthermore, the liquid crystal compound contained in the liquid crystal composition of the present invention has a specific resistance of 1×10 －９ Ω・m or more 1×10 －７ The liquid crystal compound contained in the liquid crystal composition of the present invention is not particularly limited as long as it can be adjusted to less than Ω m. Specifically, for example, a combination of target physical property values, i.e., a nematic phase-isotropic liquid phase transition temperature (Tni), a refractive index anisotropy (Δn), and a dielectric anisotropy (Δε), is set, and the liquid crystal compound is prepared by using a component liquid crystal compound alone or by mixing a plurality of component liquid crystal compounds so as to match or approximate the target physical property values.

[0032] The nematic phase-isotropic liquid phase transition temperature (Tni) of the liquid crystal compound contained in the liquid crystal composition of the present invention is specifically, for example, 40°C to 150°C, and preferably 80°C to 150°C.

[0033] The refractive index anisotropy (Δn) of the liquid crystal compound contained in the liquid crystal composition of the present invention is specifically, for example, 0.01 to 0.50, preferably 0.1 to 0.4, and most preferably 0.1 to 0.3.

[0034] The dielectric anisotropy (Δε) of the liquid crystal compound contained in the liquid crystal composition of the present invention is specifically, for example, 1 to 25, preferably 5 to 20, and most preferably 5 to 10. In the case of a negative-type liquid crystal compound, the dielectric anisotropy (Δε) value is a negative value.

[0035] Specific examples of component liquid crystal compounds used to prepare the liquid crystal compound contained in the liquid crystal composition of the present invention include cyanobiphenyl-based liquid crystal compounds, ester-based liquid crystal compounds, Schiff-based liquid crystal compounds, tolan-based liquid crystal compounds, PCP-based liquid crystal compounds, and carboxylic acid-based liquid crystal compounds.

[0036] Specific examples of the cyanobiphenyl liquid crystal compound include at least one selected from 4-cyano-4'-ethylbiphenyl, 4-cyano-4'-pentylbiphenyl, 4-cyano-4'-octyloxybiphenyl, 4-cyano-4'-n-pentoxybiphenyl, 4-cyano-4'-propylbiphenylcyclohexane, and 4-cyano-4'-pentylterphenyl.

[0037] Specific examples of the ester liquid crystal compound include at least one selected from 4-pentyl 4'-hexyloxyphenyl ester, 4-cyano-4'-butylphenyl ester, 4-cyano-4'-pentylphenyl ester, 4-cyano-4'-hexyloxyphenyl ester, 3-fluoro-4-cyano-4'-ethylphenyl ester, 3,4-fluoro-4'-ethylphenyl ester, 4-cyano-3,5-bifluoro-4'-ethylphenyl ester, and 4-ethoxy-4'-propylphenyl cyclohexane ester.

[0038] The Schiff liquid crystal compound is specifically, for example, at least one selected from 4-methoxybenzylidene-4-butylaniline and 4-ethoxybenzylidene-4-butylaniline.

[0039] Specific examples of the tolan-based liquid crystal compound include at least one selected from 4'-methylphenyl trans, 4-butoxy-4'-propylphenyl trans, 4-fluoro-4'-ethylphenyl trans, 3,4-fluoro-4'-ethylphenyl trans, 3,4,5-trifluoro-4'-ethylphenyl trans, 4-ethyl-4'-propylcyclohexane trans, 4'-pentylcyclohexane ester phenyl trans, 4-methoxy-4'-propylcyclohexane ester biphenyl trans, 4-fluoro-4'-propylcyclohexane ester biphenyl trans, 4-methyl-4'-propylterphenyl trans ester, and 4-cyano-4'-ethyltriphenyl trans ester.

[0040] Specific examples of the PCP liquid crystal compound include at least one selected from 4-fluoro-4'-alkylphenyl ester cyclohexane ester phenyl, 3,4-fluoro-4'-alkylphenyl ester cyclohexane ester phenyl, and 4-alkyl-4'-alkylphenyl ester cyclohexane ester phenyl.

[0041] The carboxylic acid liquid crystal compound is specifically at least one selected from p-alkylbenzoic acid, alkoxybenzoic acid, alkylphenyl ester benzoic acid, and alkylcyclohexane ester benzoic acid.

[0042] The case where the liquid crystal compound contained in the liquid crystal composition of the present invention is prepared by using the component liquid crystal compound alone means that the component liquid crystal compound alone has the target physical property values.

[0043] The content of the liquid crystal compound contained in the liquid crystal composition of the present invention can be specifically set to, for example, 15 to 75% by mass based on the total amount of the liquid crystal composition of the present invention.

[0044] The liquid crystal composition of the present invention contains a polymerizable organic compound and a liquid crystal compound, and the liquid crystal composition of the present invention has a specific resistance of 1×10 －１１ Ω・m or more 1×10 －５ The liquid crystal composition of the present invention may contain any compound as long as it has a resistivity of less than Ω·m.

[0045] For example, the liquid crystal composition of the present invention may contain at least one additive compound selected from a piperidine compound, a phosphate compound, or a halogen compound. When the liquid crystal composition of the present invention contains such an additive compound, ionic conduction is induced, and the specific resistance of the liquid crystal composition of the present invention can be increased to 1×10 －１１ Ω・m or more 1×10 －５ Easy to adjust to less than Ω·m.

[0046] High-purity liquid crystal compounds with few impurities generally have high resistivity, and it is difficult to reduce the resistivity of the liquid crystal compound alone. Similarly, it is difficult to reduce the resistivity of a liquid crystal composition containing a liquid crystal compound and a polymerizable organic compound monomer because the organic compound becomes a polymer after polymerization and hardening and cannot be mixed into the liquid crystal compound. Therefore, one method for reducing the resistivity of a liquid crystal composition is to add an additive compound that can induce ionic conduction and reduce the resistivity.

[0047] Specific examples of the piperidine compound include piperidine, ethyl piperidine-4-carboxylate, methyl piperidine-4-carboxylate, piperidine-1-sulfonyl chloride, piperidine-4-carboxamide, 1-piperidinethiocarboxamide, ethyl piperidin-1-ylacetate, and 1-hydroxypiperidine.

[0048] Specific examples of the phosphoric acid compound include chlorodiphenylphosphine, diphenyl phosphate, tert-butylphosphonic acid dichloride, diethyl phosphoramidate, phenylphosphinic acid, 2-ethylhexyl acid phosphate, and dibutyl phosphate.

[0049] Specific examples of the halogen compound include 4-(aminosulfonyl)-7-fluoro-2,1,3-benzoxadiazole, sodium fluoride, N-fluoropyridinium trifluoromethanesulfonate, sodium fluorophosphate, fluoro(phenyl)acetic acid, ethyl fluoroiodoacetate, sodium chloride, ammonium chloride, potassium chloride, calcium chloride, bromoacetic acid, methyl bromoacetate, bromosuccinic acid, sodium bromide, potassium bromide, sodium iodide, potassium iodide, calcium iodide, and methylammonium iodide.

[0050] The content of the additive compound contained in the liquid crystal composition of the present invention can be specifically, for example, 0.2 to 17% by mass, preferably 5.0 to 14.0% by mass, based on the total amount of the liquid crystal composition of the present invention. When the content of the additive compound contained in the liquid crystal composition of the present invention is 0.2 to 17% by mass, based on the total amount of the liquid crystal composition of the present invention, the specific resistance of the liquid crystal composition of the present invention can be 1×10 －１１ Ω・m or more 1×10 －５ Furthermore, when the content of the additive compound contained in the liquid crystal composition of the present invention is 5.0 to 14.0% by mass based on the total amount of the liquid crystal composition of the present invention, the specific resistance of the liquid crystal composition of the present invention can be adjusted to less than 1×10 －９ Ω・m or more 1×10 －７ Easy to adjust to less than Ω·m.

[0051] In the liquid crystal composition of the present invention, the additive compound may be piperidine-4-ethyl carboxylate, and the content of the additive compound may be 5.0 to 13.0% by mass based on the total amount of the liquid crystal composition of the present invention. Under these conditions, the specific resistance of the liquid crystal composition of the present invention may be 1×10 －９ Ω・m or more 1×10 －７ The resistance can be easily adjusted to less than Ω·m, and the hysteresis in the liquid crystal element of the present invention to which the liquid crystal composition of the present invention is applied can be particularly suppressed, and the liquid crystal alignment property can be particularly improved.

[0052] Next, the liquid crystal element of the present invention will be described. Fig. 1 is a schematic cross-sectional view showing an example of a liquid crystal element to which the present invention is applied. The liquid crystal element 1 of the present invention shown in Fig. 1 includes a first transparent resin film substrate 2 in the form of a thin film having a planar shape.

[0053] The liquid crystal element 1 of the present invention also includes a first transparent conductive film 4. Here, the first transparent conductive film 4 is disposed on one surface side of the first transparent resin film substrate 2 and has conductivity.

[0054] The liquid crystal element 1 of the present invention also includes a liquid crystal layer 6. Here, the liquid crystal layer 6 is disposed on the side of the first transparent conductive film 4 opposite to the first transparent resin film substrate 2, and contains the liquid crystal composition of the present invention.

[0055] The liquid crystal element 1 of the present invention also includes a second transparent conductive film 5. Here, the second transparent conductive film 5 is disposed on the opposite side of the liquid crystal layer 6 from the first transparent conductive film 4, and has conductivity. The liquid crystal element 1 of the present invention also includes a second transparent resin film substrate 3 in the form of a thin film having a planar shape. Here, the second transparent resin film substrate 3 is disposed on the opposite side of the second transparent conductive film 5 from the liquid crystal layer 6.

[0056] That is, the first transparent conductive film 4 covers one surface of the first transparent resin film substrate 2, and the second transparent conductive film 5 covers one surface of the second transparent resin film substrate 3. The liquid crystal layer 6 is in contact with the first transparent conductive film 4 and the second transparent conductive film 5.

[0057] As shown in FIG. 1, the liquid crystal element 1 of the present invention is a laminate in which a liquid crystal layer 6 is sandwiched between a first transparent resin film substrate 2 provided with a first transparent conductive film 4 and a second transparent resin film substrate 3 provided with a second transparent conductive film 5.

[0058] The first transparent resin film substrate 2 and the second transparent resin film substrate 3 are each made of a material commonly used for the substrate of a typical liquid crystal element, such as a polymer film made of polyethylene, polystyrene, polyethylene terephthalate (PET), polyvinyl alcohol, polycarbonate, polyvinyl chloride, polyimide, polysulfone, cycloolefin polymer, or triacetyl cellulose.

[0059] The first transparent resin film substrate 2 is an example of a first substrate, and the second transparent resin film substrate 3 is an example of a second substrate. The first substrate and the second substrate do not necessarily have to be made of a resin film, and may be made of, for example, a glass substrate.

[0060] The first transparent conductive film 4 and the second transparent conductive film 5 are each made of a material that is used for conductive films in ordinary liquid crystal elements, such as indium tin oxide (ITO), fluorine-doped tin oxide (FTO), tin oxide, zinc oxide, and carbon nanotubes.

[0061] The first transparent conductive film and the second transparent conductive film are examples of the first conductive film and the second conductive film, respectively.

[0062] 1, in order to apply a voltage to the liquid crystal element 1 of the present invention, a conductor 7 is electrically connected to the liquid crystal element 1 of the present invention. That is, at the end of the liquid crystal element 1 of the present invention, a part of the liquid crystal layer 6 is removed to expose a part of the first transparent conductive film 4 and a part of the second transparent conductive film 5. Then, one end of each of two conductors 7 is electrically connected to the exposed part of the first transparent conductive film 4 and the exposed part of the second transparent conductive film 5. The other end of the conductor 7 is connected to a power source (not shown).

[0063] The driving response of liquid crystal elements in general, including the liquid crystal element 1 of the present invention, is measured as follows: Fig. 2 is a schematic diagram showing an example of an apparatus for measuring the driving response of a liquid crystal element.

[0064] As shown in Figure 2, when measuring the drive response of the liquid crystal element 1 of the present invention, a laser oscillator 20 capable of emitting laser light, a temperature-controlled stage 30 for a microscope provided with an observation window 31 that can transmit the laser light, a photoreceiver 33 capable of receiving the laser light that has transmitted through the observation window 31, and an oscilloscope 40 capable of measuring the intensity of the laser light received by the photoreceiver 33 are used.

[0065] Here, a sample stage 32 on which the liquid crystal element 1 of the present invention can be placed is provided within the microscope temperature control stage 30. The sample stage 32 is provided with a flow path through which a refrigerant for cooling the sample stage 32 can be introduced, and a heater for heating the sample stage 32 is built in. Illustrations of such flow paths and heaters are omitted. With this configuration, the liquid crystal element 1 of the present invention placed on the sample stage 32 can be cooled or heated indirectly via the sample stage 32.

[0066] Although not shown, the temperature-controlled stage 30 for the microscope has electrode terminals, through which a voltage can be applied to the liquid crystal element 1 of the present invention through conductors. The sample stage 32 is made of a material that can transmit laser light. As shown in Fig. 2, the light receiver 33 is located within the temperature-controlled stage 30 for the microscope, on the side of the sample stage 32 opposite to the surface on which the liquid crystal element 1 of the present invention is placed.

[0067] Furthermore, when no voltage is applied to the liquid crystal element 1 of the present invention, the liquid crystal element 1 of the present invention does not transmit, i.e., blocks, laser light, and when a voltage is applied to the liquid crystal element 1 of the present invention, the liquid crystal element 1 of the present invention transmits laser light. The state in which no voltage is applied to the liquid crystal element 1 of the present invention is referred to as "OFF", and the state in which a voltage is applied to the liquid crystal element 1 of the present invention is referred to as "ON".

[0068] Therefore, the light receiver 33 can receive the laser light that has passed through the observation window 31 , the liquid crystal element 1 of the present invention, and the sample stage 32 .

[0069] Examples and Comparative Examples A liquid crystal composition of the present invention was prepared using a liquid crystal compound, a polymerizable organic compound, and an additive compound. －１１ Ω・m or more 1×10 －５ It was adjusted to less than Ω·m.

[0070] For comparison, a conventional liquid crystal composition was prepared using a liquid crystal compound, a polymerizable organic compound, and an additive compound. At this time, the specific resistance of the liquid crystal composition was 1×10 －１１ Ω・m or more 1×10 －５So as not to fall within the range of less than Ω·m, i.e., 1×10 －１１ Less than Ω·m or 1×10 －５ It was adjusted to Ω·m or more.

[0071] The specific types and physical properties of the liquid crystal compounds used are shown in Table 1. The specific monomers of the organic compounds used and the content of the monomers based on the total amount of the liquid crystal composition are shown in Table 2.

[0072] Table 3 shows the contents of the liquid crystal compound, organic compound, and additive compound based on the total amount of the liquid crystal composition, the specific names of the additive compounds used, and the resistivity of the liquid crystal composition. Here, the contents of the organic compounds shown in Table 3 are the sum of the contents of the monomers shown in Table 2. The resistivity of the liquid crystal composition was measured using a liquid crystal resistivity measurement system SR-6517 manufactured by Toyo Corporation.

[0073]

[0074]

[0075]

[0076] Next, the prepared liquid crystal composition of the present invention was used to fabricate a liquid crystal element 1 of the present invention shown in Figure 1. Also, the prepared conventional liquid crystal composition was used to fabricate a liquid crystal element (hereinafter referred to as a "conventional liquid crystal element") having the same structure as the liquid crystal element of the present invention shown in Figure 1.

[0077] Then, an AC voltage was applied to the liquid crystal element 1 of the present invention and the conventional liquid crystal element while varying it arbitrarily from 0 V to 100 V, and the corresponding "haze ratio" and "total light transmittance" were measured. On the other hand, an AC voltage was applied to the liquid crystal element 1 of the present invention while varying it arbitrarily from 100 V to 0 V, and the corresponding "haze ratio" and "total light transmittance" were measured. Here, the "haze ratio" and "total light transmittance" were measured using a haze meter (NDH-7000SPII, manufactured by Nippon Denshoku Industries Co., Ltd.). The results are shown in Table 4. Here, the difference between the "total light transmittance when OFF" and the "total light transmittance when ON" is shown in Table 4 as "contrast."

[0078]

[0079] The hysteresis curves of each example and each comparative example are shown in Figures 3 to 16. The hysteresis curves are obtained by plotting the change in haze ratio when an AC voltage is gradually applied from 0 V to 100 V, and then gradually decreasing the AC voltage back down to 0 V after applying the AC voltage to 100 V, and similarly showing (plotting) the change in haze ratio.

[0080] That is, Fig. 3 is a schematic diagram showing the hysteresis curve of a liquid crystal element to which the present invention is applied (Example 1). Fig. 4 is a schematic diagram showing the hysteresis curve of a liquid crystal element to which the present invention is applied (Example 2). Fig. 5 is a schematic diagram showing the hysteresis curve of a conventional liquid crystal element (Comparative Example 1). Fig. 6 is a schematic diagram showing the hysteresis curve of a liquid crystal element to which the present invention is applied (Example 3).

[0081] Fig. 7 is a schematic diagram showing the hysteresis curve of a liquid crystal element (Example 4) to which the present invention is applied. Fig. 8 is a schematic diagram showing the hysteresis curve of a liquid crystal element (Example 5) to which the present invention is applied. Fig. 9 is a schematic diagram showing the hysteresis curve of a liquid crystal element (Example 6) to which the present invention is applied. Fig. 10 is a schematic diagram showing the hysteresis curve of a liquid crystal element (Example 7) to which the present invention is applied.

[0082] FIG. 11 is a schematic diagram showing the hysteresis curve of a conventional liquid crystal element (Comparative Example 2). FIG. 12 is a schematic diagram showing the hysteresis curve of a liquid crystal element to which the present invention is applied (Example 8). FIG. 13 is a schematic diagram showing the hysteresis curve of a liquid crystal element to which the present invention is applied (Example 9). FIG. 14 is a schematic diagram showing the hysteresis curve of a liquid crystal element to which the present invention is applied (Example 10). FIG. 15 is a schematic diagram showing the hysteresis curve of a conventional liquid crystal element (Comparative Example 3). FIG. 16 is a schematic diagram showing the hysteresis curve of a conventional liquid crystal element (Comparative Example 4). In FIGS. 3 to 16, the vertical axis represents the haze ratio, and the horizontal axis represents the applied voltage.

[0083] As is clear from the resistivity values ​​shown in Table 3 and Figures 3 to 16, the resistivity value was 1 × 10 －１１Ω・m or more 1×10 －５ The hysteresis curves of the liquid crystal elements of Examples 1 to 10 using the liquid crystal compositions of the present invention, each having a specific resistance in the range of less than Ω·m, are －１１ Ω・m or more 1×10 －５ The hysteresis was smaller than the hysteresis curves of the liquid crystal devices of Comparative Examples 1 to 4, which used conventional liquid crystal compositions that were not in the range of less than Ω·m.

[0084] The resistivity is 3.1 x 10 －８ The hysteresis loop of the liquid crystal element of Example 5 using the liquid crystal composition with a specific resistance of 5.7×10 －９ The hysteresis loop of the liquid crystal element of Example 7 using the liquid crystal composition with a specific resistance of 2.1×10 －８ The hysteresis loop of the liquid crystal element of Example 9 using the liquid crystal composition of Ω·m and the specific resistance of 2.4×10 －９ The hysteresis curve of the liquid crystal device of Example 10, which used a liquid crystal composition of Ω·m, showed a particularly small hysteresis.

[0085] The criteria for judgment based on the values ​​shown in Table 4 are as follows: Namely, if the haze ratio was 10% or less, it was judged to be transparent. If the "voltage at which the haze ratio was less than 10%" or the "voltage at which the haze ratio exceeded 90%" was 100 V or less, it was judged to have "high responsiveness," and if it exceeded 100 V, it was judged to have "low responsiveness." Furthermore, the greater the difference between the "total light transmittance when OFF" and the "total light transmittance when ON," it was judged to have better contrast.

[0086] As is clear from Table 4, the liquid crystal elements of Examples 1 to 10 had a haze ratio of 10% or less when either OFF or ON, and were therefore judged to be transparent. On the other hand, the liquid crystal elements of Comparative Examples 1 and 2 did not have a haze ratio of 10% or less when either OFF or ON, and therefore could not be judged to be transparent.

[0087] Furthermore, as is clear from Table 4, the liquid crystal elements of Examples 1 to 10 had "voltages at which the haze ratio falls below 10%" or "voltages at which the haze ratio exceeds 90%" that were all 100 V or less, and were therefore judged to have "high responsiveness." On the other hand, the liquid crystal elements of Comparative Examples 1 and 2 and 3 had "voltages at which the haze ratio falls below 10%" or "voltages at which the haze ratio exceeds 90%" that exceeded 100 V, and were therefore judged to have "low responsiveness."

[0088] Furthermore, as is clear from Table 4, the "contrast," which is the difference between the "total light transmittance when OFF" and the "total light transmittance when ON," was large, at 20% or more, for all of the liquid crystal elements of Examples 1 to 10, and it was judged that the contrast was good. On the other hand, the "contrast" was small, at 10% or less, for all of the liquid crystal elements of Examples 1 to 4, and it was not judged that the contrast was good.

[0089] Furthermore, although the liquid crystal composition of Example 9 and the liquid crystal composition of Comparative Example 1 differ in that the liquid crystal composition of Example 9 contains a "trifunctional acrylate ester monomer" while the liquid crystal composition of Comparative Example 1 contains a "trifunctional methacrylate ester monomer," both compositions are composed of almost the same organic compounds and additive compounds, and the only significant difference is the amount of additive compound blended, but the results were significantly different.

[0090] That is, the specific resistance of the liquid crystal composition of Example 9 was 2.1×10 －８ Ω·m, whereas the specific resistance of the liquid crystal composition of Comparative Example 1 was 1.6×10 －１２ 5 and 13, the hysteresis curve of the liquid crystal element of Example 9 was smaller than that of the liquid crystal element of Comparative Example 1. Furthermore, as can be seen from Table 4, the contrast of the liquid crystal element of Example 9 was 29.7%, while the contrast of the liquid crystal element of Comparative Example 1 was 7.3%, which was significantly lower.

[0091] On the other hand, when the liquid crystal composition of Example 2 and the liquid crystal composition of Comparative Example 1 were compared, the results were significantly different. That is, the specific resistance of the liquid crystal composition of Example 2 was 1.0×10 －１１Ω·m, whereas the specific resistance of the liquid crystal composition of Comparative Example 1 was 1.6×10 －１２ 4 and 5, the hysteresis curve of the liquid crystal element of Example 2 has a smaller hysteresis than the hysteresis curve of the liquid crystal element of Comparative Example 1. Furthermore, as can be seen from Table 4, the contrast of the liquid crystal element of Example 2 was 30.4%, while the contrast of the liquid crystal element of Comparative Example 1 was 7.3%, which was significantly lower.

[0092] As described above, the specific resistance of the conventional liquid crystal composition is 10 ９ A liquid crystal element using a liquid crystal composition having a resistivity that is very low compared to Ω·m or more and that falls within a specific range has a smaller hysteresis and a larger contrast than a liquid crystal element using a liquid crystal composition having a resistivity slightly outside this specific range. －１１ Ω・m or more 1×10 －５ The present invention, which adjusts the resistance to less than Ω·m, can be said to make a great contribution to industrial development.

[0093] As described above, the liquid crystal composition of the present invention has a specific resistance of 1×10 －１１ Ω・m or more 1×10 －５ Since the specific resistance of the liquid crystal composition of the present invention is less than Ω·m, the hysteresis of the liquid crystal element of the present invention using the liquid crystal composition of the present invention can be suppressed. －１１ Ω・m or more 1×10 －５ Since the resistivity is less than Ω·m, the liquid crystal alignment can be improved. By improving the liquid crystal alignment, the black display level in the dark state can be increased, and the contrast can be improved.

[0094] Therefore, the liquid crystal composition of the present invention can realize the production of a liquid crystal element having good response and contrast. In addition, the liquid crystal composition of the present invention has a liquid crystal layer containing the liquid crystal composition of the present invention, and therefore has good response and contrast.

[0095] REFERENCE SIGNS LIST 1 Liquid crystal element 2 First transparent resin film substrate 3 Second transparent resin film substrate 4 First transparent conductive film 5 Second transparent conductive film 6 Liquid crystal layer 7 Conductive wire 20 Laser oscillator 30 Temperature-controlled stage for microscope 31 Observation window 32 Sample stage 33 Photoreceiver 40 Oscilloscope

Claims

1. A liquid crystal composition containing a polymerizable organic compound and a liquid crystal compound, wherein the liquid crystal composition has a specific resistance of 1×10 －１１ Ω・m or more 1×10 －５ A liquid crystal composition having a resistivity of less than Ω m, and containing at least one additive compound selected from ethyl piperidine-4-carboxylate, piperidine, or diphenyl phosphate, wherein the content of the additive compound is 0.3 to 16 mass % based on the total amount of the liquid crystal composition.

2. The liquid crystal composition has a specific resistance of 1×10 －９ Ω・m or more 1×10 －７ The liquid crystal composition according to claim 1 , wherein the liquid crystal composition has a resistance of less than Ω·m.

3. The liquid crystal composition according to claim 2, wherein the additive compound is piperidine-4-ethyl carboxylate, and the content of the additive compound is 5.0 to 13.0% by mass based on the total amount of the liquid crystal composition.

4. A liquid crystal display device comprising: a planar first substrate; a first conductive film disposed on one surface of the first substrate and having conductivity; a liquid crystal layer disposed on the side of the first conductive film opposite the first substrate and having a liquid crystal composition; a second conductive film disposed on the side of the liquid crystal layer opposite the first conductive film and having conductivity; and a planar second substrate disposed on the side of the second conductive film opposite the liquid crystal layer, wherein the liquid crystal composition contains a polymerizable organic compound and a liquid crystal compound, and the specific resistance of the liquid crystal composition is 1×10 －１１ Ω・m or more 1×10 －５ a liquid crystal element having a resistivity of less than Ω·m, the liquid crystal composition containing at least one additive compound selected from ethyl piperidine-4-carboxylate, piperidine, or diphenyl phosphate, and a content of the additive compound in the liquid crystal composition being 0.3 to 16 mass % based on the total mass of the liquid crystal composition.

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