Liquid crystal composition, liquid crystal display element, or liquid crystal display

Abstract

The application belongs to the technical field of liquid crystal materials, and particularly relates to a liquid crystal composition and a liquid crystal display element or a liquid crystal display containing the liquid crystal composition. The application discloses a polymer-stabilized complex liquid crystal composition, characterized in that the liquid crystal composition contains one or more compounds shown in formula I, one or more compounds shown in formula II, at least one of compounds shown in formula S-1 and formula S-2, and at least one polymerizable compound:

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of liquid crystal materials, and particularly relates to a polymer-stabilized alignment type liquid crystal composition and a liquid crystal display element or a liquid crystal display containing the same. BACKGROUND

[0002] There are many display modes for TFT-LCD, such as TN-TFT, IPS-TFT, VA-TFT and PSVA-TFT. No matter what display mode is needed, the liquid crystal composition has the following properties:

[0003] (1) stable chemical and physical properties; (2) low viscosity; (3) suitable dielectric delta epsilon; (4) suitable refractive index delta n; (5) good mutual solubility with other liquid crystal compounds.

[0004] Among them, the PSVA-TFT display mode has the characteristics of high contrast and wide viewing angle in addition to the above-mentioned properties. We know that there is a complex process flow in the manufacturing process of liquid crystal display, one of which is the PI (Polyimide) coating process. The purpose of PI coating is that the liquid crystal can be uniformly arranged in the liquid crystal display, but with the development of the market and the requirement of cost, it is considered whether some substances can be added to the liquid crystal to make the liquid crystal uniformly arranged in the display, so as to save the PI process and the cost of purchasing PI, so as to achieve the purpose of reducing the production cost. This is a new display mode technology emerging in the market- SAVA technology (also called PI-less). polyimide We know that the PSVA technology is to generate a layer of polymer on the alignment film which can form a pre-tilt angle for VA liquid crystal, so it is also called polymer stabilized alignment (PSA) technology. The process of forming this polymer layer is to add a certain proportion of high-purity reactive liquid crystal (Reactive Mesogen) to the ordinary VA liquid crystal, which is a kind of phototropic monomer. The reactive liquid crystal has a liquid crystal nucleus of ordinary liquid crystal molecules, and one or more acrylate groups or other reactive functional groups at the end. The reactive functional groups are polymerized into a high molecular network after UV irradiation, which can be permanently fixed. Since the polymerization initiator used is mostly 254-365 nm UV photosensitizer, it is called UV reactive liquid crystal. SAVA technology is similar to PSVA technology, only that a self-alignment agent liquid crystal material is added to the PSVA liquid crystal, and the same process conditions as PSVA are adopted to make the liquid crystal molecules uniformly arranged in the display.

[0005]

[0006] ​In summary, the SAVA technology has many advantages, but the formation of the pre-tilt angle of the SAVA technology needs to go through a suitable UV1 and UV2 process. If the film layer formed by the self-alignment agent is not stable enough, display defects will occur during long-time display lighting, and even broken bright spots will be generated, affecting the sense; and the matching of the self-alignment agent and the RM is also very important. The film thickness and surface morphology formed by different self-alignment agents and RMs in the UV process are different. For example, different matching may affect the generation rate of the UV1 pre-tilt angle; or when the UV reaction is carried out, larger particles are generated on the surface, forming broken bright spots. Therefore, a suitable matching of the self-alignment agent material and the RM, the formation of a more suitable pre-tilt angle and a more uniform surface morphology, and the provision of better picture quality by the micro display become problems that need to be solved urgently for the SAVA display. SUMMARY

[0007] In order to solve the above technical problems, the inventors have conducted in-depth research and a large number of experiments and found that by using the liquid crystal composition of the present application, a specific self-alignment agent and an RM material are added on the basis of maintaining a suitable optical anisotropy (Δn), a more optimal pre-tilt angle and a more uniform surface morphology are formed by a suitable matching ratio, the final residual image is improved, and the final yield of the panel is improved.

[0008] To achieve the above object, the present application adopts the following technical scheme:

[0009] The present application provides a polymer-stabilized liquid crystal composition, preferably, the liquid crystal composition comprises one or more compounds represented by formula I, one or more compounds represented by formula II, at least one of the compounds represented by formula S-1 and formula S-2, and at least one polymerizable compound:

[0010]

[0011] wherein,

[0012] R1, R2, R3, R0 each independently represents an alkyl group with a carbon atom number of 1-5;

[0013] R4 represents an alkoxy group with a carbon atom number of 1-5;

[0014] X1, X2 each independently represents an alkylene group with a carbon atom number of 3-9.

[0015] The second object of the present application also provides a liquid crystal display element comprising the liquid crystal composition of the present application, and the liquid crystal display element is an active matrix addressing display element or a passive matrix addressing display element.

[0016] The third object of the present application also provides a liquid crystal display comprising the liquid crystal composition of the present application, and the liquid crystal display is an active matrix addressing display or a passive matrix addressing display.

[0017] Inventive Effects

[0018] The liquid crystal composition of the present application adds specific self-alignment agent and RM material on the basis of maintaining suitable optical anisotropy (Δn), forms a more optimal pre-tilt angle and more uniform surface morphology by appropriate matching ratio, improves the final residual image, improves the final yield of the panel, and is particularly suitable for liquid crystal display elements or liquid crystal displays for curved surface display. DETAILED DESCRIPTION

[0019] [liquid crystal composition]

[0020] The present application provides a polymer-stabilized liquid crystal composition, preferably, the liquid crystal composition comprises one or more compounds represented by Formula I, one or more compounds represented by Formula II, at least one of the compounds represented by Formula S-1 and Formula S-2, and at least one polymerizable compound:

[0021]

[0022]

[0023] wherein,

[0024] R1, R2, R3, R0 each independently represents an alkyl group having 1-5 carbon atoms;

[0025] R4 represents an alkoxy group having 1-5 carbon atoms;

[0026] X1, X2 each independently represents an alkylene group having 3-9 carbon atoms.

[0027] The liquid crystal composition of the present application, preferably, the aforementioned compound represented by Formula I is selected from the group consisting of the following compounds represented by Formula I-1 to I-3:

[0028]

[0029] The liquid crystal composition of the present application, preferably, the aforementioned compound represented by Formula II is selected from the group consisting of the following compounds represented by Formula II-1 to II-4:

[0030]

[0031]

[0032] The liquid crystal composition of the present application, preferably, the aforementioned compound represented by Formula S-1 is selected from the group consisting of the following compounds represented by Formula S-1-1 to S-1-2:

[0033]

[0034] The liquid crystal composition of the present application, preferably, the aforementioned compound represented by formula S-2 is selected from the group consisting of compounds represented by formulae S-2-1 to S-2-2:

[0035]

[0036]

[0037] The liquid crystal composition of the present application, preferably, the aforementioned compound represented by formula S-1 and / or S-2 is added in an amount of 0.1 to 1%, particularly 0.8 to 1%, in addition to the total mass percentage of the liquid crystal composition.

[0038] The liquid crystal composition of the present application, preferably, the aforementioned polymerizable compound is selected from the group consisting of compounds represented by formulae RM-1 to RM-5:

[0039]

[0040]

[0041] The liquid crystal composition of the present application, preferably, the aforementioned polymerizable compound is added in an amount of 0.1 to 0.5%, particularly 0.3 to 0.4%, in addition to the total mass percentage of the liquid crystal composition.

[0042] The liquid crystal composition of the present application, preferably, further comprises one or more compounds represented by formula III:

[0043]

[0044] wherein,

[0045] R5, R6 each independently represents an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms.

[0046] The liquid crystal composition of the present application, preferably, the aforementioned compound represented by formula III is selected from the group consisting of compounds represented by formulae III-1 to III-5:

[0047]

[0048] The liquid crystal composition of the present application, preferably, further comprises one or more compounds represented by formula IV:

[0049]

[0050] wherein,

[0051] R7, R8 each independently represents an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms.

[0052] represents

[0053] The liquid crystal composition of the present application, preferably, the aforementioned compound represented by Formula IV is selected from the group consisting of compounds represented by Formulas IV-1 to IV-4:

[0054]

[0055] The liquid crystal composition of the present application, preferably, further comprises one or more compounds represented by Formula V:

[0056]

[0057] wherein,

[0058] R9, R 10 each independently represents an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms;

[0059] represents

[0060] The liquid crystal composition of the present application, preferably, the aforementioned compound represented by Formula V is selected from the group consisting of compounds represented by Formulas V-1 to V-7:

[0061]

[0062] The liquid crystal composition of the present application, preferably, further comprises one or more compounds represented by Formula VI:

[0063]

[0064] wherein,

[0065] R 11 , R 12 each independently represents an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms;

[0066] m represents 1 or 2.

[0067] The liquid crystal composition of the present application, preferably, the aforementioned compound represented by Formula VI is selected from the group consisting of compounds represented by Formulas VI-1 to VI-2:

[0068]

[0069] The liquid crystal composition of the present application, preferably, further comprises one or more compounds represented by Formula VII:

[0070]

[0071] wherein,

[0072] R 13 represents an alkoxy group having 1 to 5 carbon atoms or

[0073] R 14 represents an alkyl group having 1 to 5 carbon atoms.

[0074] The liquid crystal composition of the present application, preferably, the aforementioned compound represented by the formula VII is selected from the group consisting of the following compounds represented by the formula VII-1:

[0075]

[0076] The liquid crystal composition of the present application, preferably, further comprises one or more compounds represented by the formula VIII:

[0077]

[0078] wherein,

[0079] R 15 represents an alkyl group having 1 to 5 carbon atoms;

[0080] R 16 represents an alkoxy group having 1 to 5 carbon atoms.

[0081] The liquid crystal composition of the present application, preferably, the aforementioned compound represented by the formula VIII is selected from the group consisting of the following compounds represented by the formula VIII-1 to VIII-3:

[0082]

[0083]

[0084] The liquid crystal composition of the present application, preferably, the mass percentage of the aforementioned compound represented by the formula VIII is 0 to 3%, preferably 0.5 to 2%.

[0085] Various functional dopants can be added to the liquid crystal composition of the present application, the content of the dopants is preferably between 0.01 to 1%, these dopants can be listed as, for example, antioxidants, ultraviolet absorbers, chiral agents.

[0086] Antioxidants can be listed as,

[0087]

[0088] wherein, t represents an integer of 1 to 10;

[0089] Chiral agents (left-handed or right-handed) can be preferably listed as, for example:

[0090]

[0091] [liquid crystal display element or liquid crystal display]

[0092] The present application also relates to a liquid crystal display element or a liquid crystal display comprising any one of the above-mentioned liquid crystal compositions; the display element or display is an active matrix display element or display or a passive matrix display element or display.

[0093] The liquid crystal display element or liquid crystal display of the present application is preferably an active matrix addressing liquid crystal display element or liquid crystal display.

[0094] The aforementioned active matrix display element or display can be exemplified by, for example, an IPS-TFT or FFS-TFT or VA-TFT liquid crystal display element or other TFT display, and is particularly suitable for a SAVA-TFT mode liquid crystal display element or liquid crystal display.

[0095] The liquid crystal display element or liquid crystal display of the present application comprises the liquid crystal composition disclosed in the present application. The liquid crystal display element or liquid crystal display of the present application has a high contrast ratio, a fast response speed and a good display viewing angle, and is mainly applied to a SAVA display mode, and is particularly suitable for a curved display element or display.

[0096] Examples

[0097] In order to more clearly illustrate the present application, the present application will be further described below in conjunction with preferred examples. Those skilled in the art should understand that the specific description below is illustrative and not limiting, and should not limit the scope of protection of the present application.

[0098] In the present specification, unless otherwise specified, percentages are mass percentages, temperatures are in degrees Celsius (℃), and the specific meanings of other symbols and test conditions are as follows:

[0099] Cp represents the liquid crystal clearing point (℃), tested by DSC quantification method;

[0100] Δn represents the optical anisotropy, n o is the refractive index of ordinary light, n e is the refractive index of non-ordinary light, and the test conditions are 25±2℃, 589nm, and Abbe refractometer test;

[0101] Δε represents the dielectric anisotropy, Δε = ε ∥ -ε ⊥ , wherein ε ∥ is the dielectric constant parallel to the molecular axis, ε ⊥ is the dielectric constant perpendicular to the molecular axis, and the test conditions are 25±0.5℃, 20 microns vertical cell, and INSTEC:ALCT-IR1 test;

[0102] K 11 is the splay elastic constant, K22 K is the twist elastic constant 33 G is the bend elastic constant, test condition: 25°C, INSTEC: ALCT-IR1, 20 microns vertical cell;

[0103] Pretilt angle (°), test condition: 25±0.5°C, SAVA test cell, machine tilt angle 45°, test equipment RETS-1000;

[0104] CR represents the contrast ratio of the liquid crystal display device, the contrast ratio is the bright state of the liquid crystal display divided by the dark state of the liquid crystal display, test condition 25±1°C, test voltage is the normal driving voltage, test frequency is 64Hz, test equipment is DMS505;

[0105] Afterimage: the afterimage of the liquid crystal display device is the level of the inherent pattern remaining after displaying a specified fixed pattern in the display area for 1000 hours, and then visually evaluating the remaining level of the inherent pattern when displaying a full screen uniformly, which is evaluated according to the following 4 grades:

[0106] ◎ No remaining

[0107] ○ There is a very small amount of remaining, which is an acceptable level

[0108] △ There is remaining, which is an unacceptable level

[0109] × There is remaining, which is very poor

[0110] The preparation method of the liquid crystal composition is as follows: each liquid crystal monomer is weighed according to a certain ratio and then placed in a stainless steel beaker, the stainless steel beaker containing each liquid crystal monomer is placed on a magnetic stirring instrument for heating and melting, after most of the liquid crystal monomers in the stainless steel beaker are melted, a magnetic rotor is added to the stainless steel beaker, the mixture is stirred uniformly, and after cooling to room temperature, the liquid crystal composition is obtained.

[0111] The preparation method of the liquid crystal display device in the embodiment of the application is as follows: first, uniformly coating alignment material on the surface of the first substrate and the second substrate, the alignment material can be selected from polyimide, heating and curing the uniformly coated alignment material, the heating temperature is 230 DEG C, to form an alignment layer; second, scattering spacers on the surface of the second substrate, and coating a frame glue along the edge of the first substrate, and curing at 120 DEG C; then, oppositely arranging the first substrate and the second substrate, and adhering to form a structure with a sandwiched space; finally, injecting a liquid crystal composition into the sandwiched space between the first substrate and the second substrate, sealing and curing, so as to seal the liquid crystal composition between the first substrate and the second substrate, and simultaneously performing power-on and ultraviolet light irradiation. The ultraviolet light irradiation is divided into two stages, including first stage ultraviolet light irradiation (UV1) and second stage ultraviolet light irradiation (UV2). The UV1 stage time is directly related to the size of the pre-tilt angle, so different alignment agents and RM contents need to control different UV1 times.

[0112] The liquid crystal monomer structure in the embodiment of the application is represented by codes, and the code representation methods of the liquid crystal ring structure, end group and linking group are shown in Table 1 and Table 2.

[0113] Table 1 corresponding code of ring structure

[0114]

[0115] Table 2 corresponding code of end group and linking group

[0116]

[0117]

[0118] For example:

[0119] The code is PPY-3-O2;

[0120] The code is CPY-2-O2;

[0121] The code is CCY-3-O2;

[0122] The code is COY-3-O2;

[0123] The code is CCOY-3-O2;

[0124] The code is CLY-3-O2;

[0125] The code is Sb-CpO-O4;

[0126] The code for this is Sc-CpO-O4.

[0127] Composition Example 1 (M1)

[0128] The formulations and corresponding properties of the liquid crystal compositions are shown in Table 3 below.

[0129] Table 3 Formulations and corresponding properties of M1 liquid crystal compositions

[0130]

[0131] Composition Example 2 (M2)

[0132] The formulations and corresponding properties of the liquid crystal compositions are shown in Table 4 below.

[0133] Table 4 Formulations and corresponding properties of M2 liquid crystal compositions

[0134]

[0135] Composition Example 3 (M3)

[0136] The formulations and corresponding properties of the liquid crystal compositions are shown in Table 5 below.

[0137] Table 5 Formulations and corresponding properties of M3 liquid crystal compositions

[0138]

[0139]

[0140] Composition Example 4 (M4)

[0141] The formulations and corresponding properties of the liquid crystal compositions are shown in Table 6 below.

[0142] Table 6 Formulations and corresponding properties of M4 liquid crystal compositions

[0143]

[0144]

[0145] Composition Example 5 (M5)

[0146] The formulations and corresponding properties of the liquid crystal compositions are shown in Table 7 below.

[0147] Table 7 Formulations and corresponding properties of M5 liquid crystal compositions

[0148]

[0149]

[0150] Composition Comparative Example 1 (D1)

[0151] The formulations and corresponding properties of the liquid crystal compositions are shown in Table 8 below.

[0152] Table 8 Formulations and corresponding properties of D1 liquid crystal compositions

[0153]

[0154]

[0155] Composition Comparative Example 2 (D2)

[0156] The formulations and corresponding properties of the liquid crystal compositions are shown in Table 9 below.

[0157] Table 9 Formulations and corresponding properties of D2 liquid crystal compositions

[0158]

[0159] Composition Comparative Example 3 (D3)

[0160] The formulations and corresponding properties of the liquid crystal compositions are shown in Table 10 below.

[0161] Table 10 Formulations and corresponding properties of D3 liquid crystal compositions

[0162]

[0163]

[0164] Composition Comparative Example 4 (D4)

[0165] The formulations and corresponding properties of the liquid crystal compositions are shown in Table 11 below.

[0166] Table 11 Formulations and corresponding properties of D4 liquid crystal compositions

[0167]

[0168]

[0169]

[0170] Table 12 Pretilt angles, pretilt angle generation rates, and contrast ratios of liquid crystal compositions

[0171]

[0172]

[0173] Among them, the symbol in the residual image performance is divided into excellent, good, general and poor according to the effect from good to bad. The refractive index of Comparative Example 1 is smaller, and the contrast is slightly poor; although the final refractive index of Comparative Example 2 and Comparative Example 3 reaches the specification, the pre-tilt angle formed is smaller, the dark state light leakage and the contrast are lower, and the display specification cannot be met.

[0174] Comparative Examples 4-7 and the embodiment comparison, Comparative Example 4 does not add a director to the embodiment formula, resulting in that the liquid crystal cannot be aligned in the display, and the panel cannot normally display; Comparative Example 5 does not add RM to the embodiment formula, and there is no pre-tilt angle formed in the liquid crystal display, the liquid crystal molecule rotation direction is disorderly during display driving, and the residual image is serious; although Comparative Example 6 and Comparative Example 7 can form alignment and pre-tilt angle, the pre-tilt angle formed by the combination of the director and RM is smaller, the contrast is lower, and the residual image performance is not good.

[0175] In summary, the liquid crystal composition of the present application adds specific self-alignment agent and RM material on the basis of maintaining suitable optical anisotropy (Δn), forms better pre-tilt angle and more uniform surface morphology by appropriate matching ratio, improves the final residual image, improves the final yield of the panel, and is used for SAVA display mode liquid crystal display element or liquid crystal display. At present, the market mainly applies to curved display element or display.

[0176] The above-mentioned embodiments disclosed in the present application are only examples for clearly illustrating the present application, and are not a limitation on the embodiments of the present application. For ordinary skilled in the art, other different forms of changes or variations can be made on the basis of the above description, and all the embodiments cannot be exhausted here. Any obvious changes or variations derived from the technical solutions of the present application still fall within the protection scope of the present application.

Claims

1. A polymer-stabilized cholesteric liquid crystal composition, characterized in that, The liquid crystal composition comprises one or more compounds represented by Formula I, one or more compounds represented by Formula II, at least one of compounds represented by Formula S-1-1 and Formula S-2-1, and at least one polymerizable compound: wherein, R1, R2, R3 each independently represents an alkyl group having 1 to 5 carbon atoms; R4 represents an alkoxy group having 1 to 5 carbon atoms; The liquid crystal composition further comprises one or more compounds represented by Formula III: wherein, R5, R6 each independently represents an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms; The liquid crystal composition further comprises one or more compounds represented by Formula V: wherein, R9, R 10 each independently represents an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms; denotes 2. The liquid crystal composition according to claim 1, characterized by The liquid crystal composition further comprises one or more compounds represented by Formula IV: wherein, R7, R8 each independently represents an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms; denotes 3. The liquid crystal composition according to claim 1, characterized by The liquid crystal composition further comprises one or more compounds represented by Formula VI: wherein, R 11 , R 12 each independently represents an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms; m represents 1 or 2.

4. The liquid crystal composition according to claim 3, characterized by The liquid crystal composition further comprises one or more compounds represented by Formula VII: wherein, R 13 represents an alkoxy group having a carbon number of 1 to 5 or R 14 represents an alkyl group having 1 to 5 carbon atoms.

5. The liquid crystal composition according to claim 4, characterized by The liquid crystal composition further comprises one or more compounds represented by Formula VIII: wherein, R 15 represents an alkyl group having 1 to 5 carbon atoms; R 16 represents an alkoxy group having 1 to 5 carbon atoms.

6. A liquid crystal display device, characterized by comprising: The liquid crystal display comprises the liquid crystal composition according to any one of claims 1 to 5, and is an active matrix addressing display or a passive matrix addressing display.

7. A liquid crystal display element, characterized by comprising: The liquid crystal display element comprises the liquid crystal composition according to any one of claims 1 to 5, and is an active matrix addressing display element or a passive matrix addressing display element.

8. The liquid crystal display element according to claim 7, wherein The active matrix addressing display element is a SAVA display mode.

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