Liquid crystal display device having a plurality of pixel electrodes
阅读说明：本技术 液晶显示器件 (Liquid crystal display device having a plurality of pixel electrodes ) 是由 梁志安 李佳明 康素敏 张璇 王东梅 于 2018-08-31 设计创作，主要内容包括：本发明提供一种液晶显示器件,所述液晶显示器件包括第一基板、第二基板,以及设置在所述第一基板和所述第二基板之间的液晶组合物；所述第一基板的与所述液晶组合物接触的表面设有配向层,且所述第二基板无配向层；所述液晶组合物包含液晶化合物、自配向剂和式Ⅰ所示的可聚合化合物,<Image he="159" wi="700" file="DDA0001785004020000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>(The invention provides a liquid crystal display device, comprising a first substrate, a second substrate, and a liquid crystal composition arranged between the first substrate and the second substrate; an alignment layer is arranged on the surface of the first substrate, which is in contact with the liquid crystal composition, and the second substrate is free of the alignment layer; the liquid crystal composition comprises a liquid crystal compound, a self-aligning agent and a polymerizable compound shown as a formula I,)
1. A liquid crystal display device, comprising a first substrate, a second substrate, and a liquid crystal composition disposed between the first substrate and the second substrate; an alignment layer is arranged on the surface of the first substrate, which is in contact with the liquid crystal composition, and the second substrate is free of the alignment layer; the liquid crystal composition comprises a liquid crystal compound, a self-aligning agent and a polymerizable compound shown as a formula I,
2. the liquid crystal display device according to claim 1, wherein the first substrate is a thin film transistor substrate, and the second substrate is a color film substrate; or the first substrate is a color film substrate, and the second substrate is a thin film transistor thin film.
3. A liquid crystal display device according to claim 1 or 2, wherein the alignment layer has a thickness of 30nm to 120 nm; the alignment layer is a polyimide film layer.
4. The liquid crystal display device according to claim 1 or 2, wherein the self-aligning agent has at least two anchoring functional groups, and 1 to 3 polymerizable functional groups.
5. A liquid crystal display device as claimed in claim 1 or 2, characterized in that the self-aligning agent is selected from the group of compounds of the formulae II 1 to II 42,
6. the liquid crystal display device according to any one of claims 1 to 5, wherein the liquid crystal compound comprises one or more compounds represented by formula III, one or more compounds represented by formula IV,
in the formula III, R1、R2Each independently represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an alkenyloxy group having 3 to 8 carbon atoms;
In the formula IV, R3、R4Each independently represents an alkyl group having 1 to 10 carbon atoms, a fluorine-substituted alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a fluorine-substituted alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, a fluorine-substituted alkenyl group having 2 to 10 carbon atoms, an alkenyloxy group having 3 to 8 carbon atoms or a fluorine-substituted alkenyloxy group having 3 to 8 carbon atoms, and R3、R4Any one or more of the radicals indicated being unconnected-CH2-each independently is optionally substituted with cyclopentylene, cyclobutyl or cyclopropylene;
Z1、Z2each independently represents a single bond, -CH2CH2-or-CH2O-；
m represents 1 or 2;
n represents 0, 1 or 2.
7. The liquid crystal display device of claim 6, wherein the one or more compounds of formula III are selected from the group consisting of compounds of formulae III 1 to III 16,
8. the liquid crystal display device according to claim 6 or 7, wherein the one or more compounds of formula IV are selected from the group consisting of compounds of formulae IV 1 to IV 14,
wherein R is3、R4Each independently represents an alkyl group having 1 to 10 carbon atoms, a fluorine-substituted alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a fluorine-substituted alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, a fluorine-substituted alkenyl group having 2 to 10 carbon atoms, an alkenyloxy group having 3 to 8 carbon atoms or a fluorine-substituted alkenyloxy group having 3 to 8 carbon atoms, and R3、R4Any one or more of the radicals indicated being unconnected-CH2-optionally each independently substituted with cyclopentylene, cyclobutyl or cyclopropylene.
9. A liquid crystal display device as claimed in any one of claims 6 to 8, characterized in that the liquid crystal compound also comprises one or more compounds of the formula VI,
wherein R is11、R12Each independently represents an alkyl group having 1 to 10 carbon atoms, a fluorine-substituted alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a fluorine-substituted alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, a fluorine-substituted alkenyl group having 2 to 10 carbon atoms, an alkenyloxy group having 3 to 8 carbon atoms or a fluorine-substituted alkenyloxy group having 3 to 8 carbon atoms, and R11、R12Any one or more of the radicals indicated being unconnected-CH2-each independently is optionally substituted with cyclopentylene, cyclobutyl or cyclopropylene;
10. A liquid crystal display device as claimed in any one of claims 6 to 9, characterized in that the liquid crystal compound also comprises one or more compounds of the formula VII,
wherein R is13And R14Each independently represents an alkyl group having 1 to 10 carbon atoms, a fluorine-substituted alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a fluorine-substituted alkoxy group having 1 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atomsA fluorine-substituted alkenyl group having 2 to 10 carbon atoms, a carbon-substituted alkenyloxy group having 3 to 8 carbon atoms or a fluorine-substituted alkenyloxy group having 3 to 8 carbon atoms;
F1、F2、F3Each independently represents H or F, and F2、F3Not simultaneously F.
Technical Field
The invention relates to the technical field of liquid crystal display. And more particularly, to a liquid crystal display device.
Background
With the development of Display technology, flat panel Display devices such as Liquid Crystal Display (LCD) devices have advantages of high image quality, power saving, thin body, and wide application range, and thus are widely used in various consumer electronics products such as mobile phones, televisions, personal digital assistants, digital cameras, notebook computers, and desktop computers, and are becoming the mainstream of Display devices.
A typical liquid crystal display device includes a Color Filter (CF) substrate, a Thin Film Transistor (TFT) substrate, a Liquid Crystal (LC) composition layer sandwiched between the Color Filter substrate and the TFT substrate, and a Sealant frame (Sealant).
Currently, in a commonly used Liquid Crystal Display (LCD), a CF substrate and a TFT substrate are respectively provided with a layer of thin film material, which mainly functions to align liquid crystal molecules in a certain direction, and is called as an alignment layer. Such alignment layers are mainly classified into a rubbing alignment type and a photo alignment type. The alignment layer has the characteristics of uniformity, adherence and stability, can be used as an insulating film between liquid crystal molecules and a substrate of a liquid crystal display device besides enabling the liquid crystal molecules to be aligned, and can keep the voltage applied to the substrate within one frame time, so that impurities such as ions in the substrate are prevented from diffusing into the liquid crystal molecules, and the effect of keeping the purity of the liquid crystal molecules is achieved. However, alignment layers also have certain disadvantages. Firstly, the rubbing alignment layer is easy to cause the problems of dust particles, static residues, brush marks and the like in the display process of the liquid crystal display device so as to reduce the manufacturing yield of the liquid crystal display device, while the photo-alignment layer can avoid the problems, but the photo-alignment layer is limited in material characteristics, poor in heat resistance and ageing resistance and weak in liquid crystal molecule anchoring capability, so that the display effect of the liquid crystal display device is influenced; secondly, the process of forming the alignment layer on the TFT-LCD is also complicated, which results in an increase in the production cost of the liquid crystal display device.
If the alignment layer in the liquid crystal display device is completely removed, the liquid crystal molecules cannot be vertically aligned. At present, a self-alignment agent is added into a liquid crystal layer, and liquid crystal molecules are vertically arranged by means of the characteristic that the self-alignment agent is adsorbed on the surface of a substrate. However, if the alignment layer is omitted completely, the liquid crystal display device may have problems such as display unevenness and poor alignment of liquid crystal molecules, and the problem of image sticking of the liquid crystal display device may be serious.
In a liquid crystal display device of PSVA (polymer Stabilized vertically Aligned liquid crystal) or SAVA (vertical self-Aligned) display mode, in which a liquid crystal layer contains a polymerizable compound as a Reactive Mesogen (RM), since there is a possibility that the Reactive Mesogen (RM) remains during the manufacturing process of the liquid crystal display device, the RM remains causing a problem of display defects such as an afterimage of the liquid crystal display device, and the larger the RM remains, the more serious the problem of the afterimage is.
Disclosure of Invention
The inventors of the present application have conducted extensive studies to obtain a liquid crystal display device having less image sticking during the display process and a simple manufacturing process, and have found that the object can be achieved by the liquid crystal display device of the present invention, thereby completing the present invention.
An object of the present invention is to provide a liquid crystal display device.
A liquid crystal display device as one aspect of the present invention includes a first substrate, a second substrate, and a liquid crystal composition disposed between the first substrate and the second substrate; an alignment layer is arranged on the surface of the first substrate, which is in contact with the liquid crystal composition, and the second substrate is free of the alignment layer; the liquid crystal composition comprises a liquid crystal compound, a self-aligning agent and a polymerizable compound shown in a formula I.
The liquid crystal display device provided by the invention has the characteristics of wider nematic phase temperature range, proper or higher birefringence anisotropy delta n and high charge retention rate, and the polymerizable compound shown in the formula I is used as the Reactive Mesogen (RM) to be matched with the liquid crystal compound and the self-alignment agent, so that the conversion rate of the Reactive Mesogen (RM) in the manufacturing process of the liquid crystal display device is improved, and the residual quantity of the Reactive Mesogen (RM) is reduced, thereby effectively shortening the manufacturing process of the liquid crystal display device, improving the production efficiency and reducing the degree of poor residual image display of the liquid crystal display device.
Detailed Description
A liquid crystal display device as one aspect of the present invention includes a first substrate, a second substrate, and a liquid crystal composition disposed between the first substrate and the second substrate; the surface of the first substrate, which is in contact with the liquid crystal composition, is provided with an alignment layer, and the second substrate is free of the alignment layer; the liquid crystal composition comprises a liquid crystal compound, a self-aligning agent and a polymerizable compound shown in a formula I.
In the process of manufacturing a liquid crystal display device, a polymerizable compound represented by formula I is photopolymerized as a Reactive Mesogen (RM) with a self-aligning agent by ultraviolet irradiation to form a polymer thin film. One side of the formed polymer film is combined with the second substrate by virtue of the physical adsorption effect between the self-alignment agent and the molecules of the second substrate, and the other side of the formed polymer film is contacted with the liquid crystal composition, and the polymer film plays a role in vertically aligning the liquid crystal molecules. The polymer film is also formed on the side of the alignment layer of the first substrate, which is contacted with the liquid crystal composition, and one side of the formed polymer film is combined with the first substrate and the other side is contacted with the liquid crystal composition by virtue of intermolecular physical adsorption, so that the polymer film can effectively prevent the problem that the yield of the liquid crystal display device is reduced due to dust particles, static residues and the like generated in the display process of the liquid crystal display device by the alignment layer.
The liquid crystal display device has the characteristics of wider nematic phase temperature range, proper or higher birefringence anisotropy delta n and high charge retention rate, and the polymerizable compound shown in the formula I is used as the Reactive Mesogen (RM) to be matched with the liquid crystal composition and the self-aligning agent, so that the conversion rate of the Reactive Mesogen (RM) in the manufacturing process of the liquid crystal display device is improved, and the residual quantity of the Reactive Mesogen (RM) is reduced, thereby effectively shortening the preparation process of the liquid crystal display device, improving the production efficiency and reducing the degree of poor residual image display of the liquid crystal display device.
Preferably, the compound represented by the formula I accounts for 0.01-1%, preferably 0.03-0.5% of the total mass of the liquid crystal composition. The content of the compound represented by the formula i is preferably 1% or less, and more preferably 0.5% or less, from the viewpoint of reducing the defective display of afterimages in the liquid crystal display device. In addition, the content of the compound represented by the formula i is preferably 0.01% or more, and more preferably 0.03% or more, from the viewpoint of forming a polymer film by polymerization with a self-aligning agent to align liquid crystal molecules, and preventing a decrease in yield of a liquid crystal display device due to dust particles, static electricity residue, and the like generated in a display process of the liquid crystal display device by an alignment layer.
In some embodiments of the liquid crystal display device of the present invention, optionally, the first substrate is a thin film transistor substrate, and the second substrate is a color filter substrate; or the first substrate is a color film substrate, and the second substrate is a thin film transistor thin film. Preferably, the first substrate is a thin film transistor substrate, and the second substrate is a color filter substrate.
In some embodiments of the liquid crystal display device of the present invention, the alignment layer has a thickness of 30nm to 120nm, preferably 40nm to 60nm, and the alignment layer is a polyimide thin film layer.
In some embodiments of the liquid crystal display device of the present invention, the self-alignment agent has at least two anchoring functional groups and 1 to 3 polymerizable functional groups.
The anchoring functional group is a functional group which plays a role in adsorbing and fixing with the substrate from the alignment agent, and can be selected from hydroxyl, ester group and carbonyl, preferably hydroxyl, and at least two. The polymerizable functional group is a functional group capable of polymerizing with the compound represented by formula I, preferably a methacrylate group, an acrylate group, a vinyl group or an oxirane group, and more preferably a methacrylate group.
In some embodiments of the liquid crystal display device of the present invention, the foregoing self-aligning agent is selected from the group consisting of compounds represented by formulas II 1 to II 42.
Preferably, the content of the compound represented by the formula II in the liquid crystal composition is 0.1-3% by mass, and preferably 0.5-1.5% by mass. This is because the content of the compound represented by the formula II in the total mass percentage of the liquid crystal composition is preferably 0.1% or more, more preferably 0.5% or more, from the viewpoint of forming a polymerizable thin film with the polymerizable compound represented by the formula I to align liquid crystal molecules and preventing a decrease in the yield of the liquid crystal display device due to dust particles, static electricity residue, and the like generated in the display process of the liquid crystal display device by the alignment layer. The content of the compound represented by formula II in the total mass percentage of the liquid crystal composition is preferably 3% or less, and more preferably 1.5% or less.
In some embodiments of the liquid crystal display device of the present invention, the liquid crystal compound comprises one or more compounds represented by formula III, one or more compounds represented by formula IV,
in the formula III, R1、R2Each independently represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an alkenyloxy group having 3 to 8 carbon atoms;
In the formula IV, R3、R4Each independently represents an alkyl group having 1 to 10 carbon atoms, a fluorine-substituted alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a fluorine-substituted alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, a fluorine-substituted alkenyl group having 2 to 10 carbon atoms, an alkenyloxy group having 3 to 8 carbon atoms or a fluorine-substituted alkenyloxy group having 3 to 8 carbon atoms, and R3、R4Any one or more of the radicals indicated being unconnected-CH2-each independently is optionally substituted with cyclopentylene, cyclobutyl or cyclopropylene;
Z1、Z2each independently represents a single bond, -CH2CH2-or-CH2O-；
m represents 1 or 2;
n represents 0, 1 or 2.
The compound shown in the formula III has the characteristics of low rotational viscosity and good intersolubility with other compounds. The lower rotational viscosity is more favorable for improving the response speed of the liquid crystal composition.
The compound shown in the formula IV is negative dielectric anisotropy, and the driving voltage of the liquid crystal composition is adjusted by the compound shown in the formula IV.
as-CH in which one or more of the aforementioned alkyl groups having 1 to 10 carbon atoms are not linked2Examples of the group substituted with a cyclopropylene group, a cyclobutylene group or a cyclopentylene group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a methylcyclopropylidene group, an ethylcyclopropylidene group, a propylcyclopropylidene group, an isopropylcyclopropylidene group, a n-butylcyclopropylidene group, an isobutylcyclopropylidene group, a tert-butylcyclopropylidene group, a methylcyclobutylene group, an ethylcyclobutylidene group, a propylcyclobutylidene group, an isopropylidene group, a n-butylidene group, an isobutylidene group, a tert-butylidene group, a methylcyclopentylene group, an ethylcyclopentylidene group, a propylcyclopentylidene group, an isopropylidene group, a n-butylcyclopentylidene group and an isobutylcyclopentylidene group. R3、R4Among the groups shown, preferred from the viewpoint of the rotational viscosity, solubility and clearing point of the liquid crystal compound is cyclopropyl, cyclobutyl or cyclopentyl.
Optionally, the liquid crystal composition is a negative dielectric anisotropy liquid crystal composition.
The content of the compound shown in the formula III in the total mass percent of the liquid crystal composition is preferably 5-60%, and more preferably 10-40%; the content of the compound shown in the formula IV in the total mass percent of the liquid crystal composition is preferably 25-90%, and more preferably 40-65%.
Optionally, the one or more compounds of formula III are selected from the group consisting of compounds of formulae III 1-III 16;
optionally, the one or more compounds of formula IV are selected from the group consisting of compounds of formulae IV 1-IV 14;
wherein the content of the first and second substances,
R3、R4with R in the compound of the formula IV3、R4Each independently represents an alkyl group having 1 to 10 carbon atoms, a fluorine-substituted alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a fluorine-substituted alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, a fluorine-substituted alkenyl group having 2 to 10 carbon atoms, an alkenyloxy group having 3 to 8 carbon atoms or a fluorine-substituted alkenyloxy group having 3 to 8 carbon atoms, and R is3、R4Any one or more of the radicals indicated being unconnected-CH2-optionally substituted with cyclopentylene, cyclobutyl or cyclopropylene.
In one embodiment, the liquid crystal compound may further include one or more compounds represented by formula vi:
wherein the content of the first and second substances,
R11、R12each independently represents an alkyl group having 1 to 10 carbon atoms, a fluorine-substituted alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a fluorine-substituted carbon atomAlkoxy of 1 to 10 carbon atoms, alkenyl of 2 to 10 carbon atoms, fluorine-substituted alkenyl of 2 to 10 carbon atoms, alkenyloxy of 3 to 8 carbon atoms or fluorine-substituted alkenyloxy of 3 to 8 carbon atoms, and R11、R12Any one or more of the radicals indicated being unconnected-CH2-optionally substituted with cyclopentylene, cyclobutyl or cyclopropylene;
each independently representOr,。
Optionally, one or more of the compounds of formula VI is selected from the group consisting of compounds of formula VI 1 to VI 7,
wherein the content of the first and second substances,
R121represents an alkyl group having 1 to 6 carbon atoms, R122Represents an alkoxy group having 1 to 6 carbon atoms, R111Represents an alkyl group having 2 to 6 carbon atoms, R112Represents an alkenyl group having 2 to 6 carbon atoms.
The terminal chain of the compound shown in the formula VI is alkenyl R112The liquid crystal compound has a higher clearing point and an elastic constant, especially a splay elastic constant K33And is beneficial to improving the parameter performance of the liquid crystal composition.
The content of the one or more compounds shown in the formula VI in the total mass percent of the liquid crystal composition is preferably 1-40%, and more preferably 5-20%.
As a liquid crystal display device according to still another aspect of the present invention, in one embodiment, optionally, the aforementioned liquid crystal compound may further comprise one or more compounds represented by formula vii:
wherein the content of the first and second substances,
R13、R14each independently represents an alkyl group having 1 to 10 carbon atoms, a fluorine-substituted alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a fluorine-substituted alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, a fluorine-substituted alkenyl group having 2 to 10 carbon atoms, an alkenyloxy group having 3 to 8 carbon atoms or a fluorine-substituted alkenyloxy group having 3 to 8 carbon atoms;
F1、F2、F3Each independently represents H or F, and F2、F3Not simultaneously F.
Alternatively, the aforementioned one or more compounds of formula VII are preferably selected from one or more of the compounds of formulae VII 1 to VII 4:
wherein R is131、R141Each independently represents an alkyl group having 1 to 6 carbon atoms.
The compounds shown in the formulas VII 1 to VII 4 have high clearing points, generally higher than 200 ℃, and can more remarkably improve the clearing points of the liquid crystal composition.
The total content of the one or more compounds represented by the formula VII is preferably 1 to 10% by mass, and more preferably 2 to 5% by mass.