CN115926808A

CN115926808A - Liquid crystal composition and liquid crystal display device comprising same

Info

Publication number: CN115926808A
Application number: CN202110599088.3A
Authority: CN
Inventors: 孙成龙; 杨亚非; 贺笛; 王盼盼; 丁文全; 徐爽
Original assignee: Jiangsu Hecheng Display Technology Co Ltd
Current assignee: Jiangsu Hecheng Display Technology Co Ltd
Priority date: 2021-05-31
Filing date: 2021-05-31
Publication date: 2023-04-07
Anticipated expiration: 2041-05-31
Also published as: CN115926808B

Abstract

The invention provides a liquid crystal composition and a liquid crystal display device comprising the same, wherein the liquid crystal composition comprises a first component and a second component which are combined; the first component comprises at least one polymerizable compound shown in the formula I, and the second component comprises 1-20% by mass of a compound shown in the formula II and 20-50% by mass of a compound shown in the formula III. The liquid crystal composition has the advantages of high polymerization speed, small bump formed after polymerization, short UV time, less residue, good low-temperature stability and good intersolubility, effectively solves the problems of 'broken bright points', 'image sticking', uneven display and the like in the PSA type liquid crystal display device, and can provide the PSA type liquid crystal display device with more excellent quality.

Description

Liquid crystal composition and liquid crystal display device comprising same

Technical Field

The invention belongs to the technical field of liquid crystal materials, and particularly relates to a liquid crystal composition and a liquid crystal display device comprising the same.

Background

Liquid Crystal Displays (LCDs) have small size, light weight, excellent Display quality, and low power consumption, and have been rapidly developed in recent years, and are widely used particularly in portable electronic information products. Liquid crystal displays are classified into PC (phase change), TN (twisted nematic), STN (super twisted nematic), ECB (electrically controlled birefringence), OCB (optically compensated bend), IPS (in-plane switching), FFS (fringe field switching), VA (vertical alignment), PSA (polymer stable alignment), and the like, according to the type of display mode.

The PSA type liquid crystal display mode is a mode in which a small amount (typically < 1wt%, for example, 0.3 wt%) of one or more polymerizable compounds is added to a liquid crystal composition, and it can be ensured that liquid crystal molecules are polymerized or crosslinked in situ in a state having an initial orientation with or without applying a voltage between electrodes after the liquid crystal composition is filled into a liquid crystal cell, thereby achieving fixation of the orientation of the liquid crystal molecules. With the development of PSA type liquid crystal display devices, they are used in various conventional liquid crystal display devices, such as PSA-VA, PSA-OCB, PSA-IPS, PSA-FFS, PSA-TN type liquid crystal displays. In a liquid crystal display of the PSA type, the liquid crystal composition comprising the polymerizable compound is located between two substrates, wherein each substrate is provided with an electrode structure, or two electrode structures are placed on one substrate. In addition, either or both of the substrates may contain an alignment layer disposed on the substrate or electrode structure (if present) to induce initial alignment of the liquid crystal composition. As with conventional liquid crystal displays, PSA type liquid crystal displays can operate as either active matrix displays or passive matrix displays. In the case of active matrix displays, individual pixels are addressed by integrated non-linear active elements (e.g. transistors); in the case of passive matrix displays, the individual pixels are typically addressed according to known multiplexing methods.

After filling the liquid crystal composition into the display device, the polymerizable compounds contained in the liquid crystal composition are typically polymerized or crosslinked in situ by UV photopolymerization by exposing the liquid crystal composition to UV radiation, and preferably while applying a voltage to the electrode structure. After UV irradiation, the polymerized or crosslinked polymerizable compound phase separates from other compounds in the liquid crystal composition and forms a polymer layer on the substrate surface, thereby causing a pre-tilt angle of the liquid crystal molecules with respect to the substrate. For liquid crystal displays of the PSA-VA, PSA-OCB, PSA-FFS and PSA-TN type, the polymerization of the polymerizable compounds is preferably carried out with application of a voltage; for the PSA-IPS mode liquid crystal display, voltage may be applied or not, and preferably, no voltage is applied.

In a method for producing a liquid crystal display of the PSA type, UV photopolymerization is effected in two steps:

in a first step (hereinafter referred to as "UV1 step"), the liquid crystal composition is exposed to UV radiation emitted by a radiation source (hereinafter referred to as "light source") while applying a voltage to the electrode structure to produce a pre-tilt angle. The more preferred polymerizable compounds should produce a smaller pretilt angle in the same time or the same pretilt angle (i.e., faster angular velocity) in a shorter UV1 irradiation time to improve production efficiency, shorten tact time (tact time) in mass production, and reduce costs. Meanwhile, the faster the angle of the polymerizable compound is, the more favorable the polymerizable compound is to be completely polymerized, thereby reducing polymer residue. To increase the angular velocity, it is preferred to use shorter wavelength UV1 radiation; in order to increase the Voltage Holding Ratio (VHR), UV1 radiation of longer wavelength is preferably used. Thus, a faster angulation speed and a higher voltage holding ratio, which are often difficult to compromise, are provided.

In the second step (hereinafter referred to as "UV2 step"), the liquid crystal composition is exposed to UV radiation without applying a voltage to the electrode structure to ensure thorough polymerization of the residual polymerizable compounds that were not polymerized in the UV1 step. It is desirable that the variation of the pretilt angle after the UV2 step be as small as possible to reduce the possibility of display unevenness of the PSA type liquid crystal display due to the influence of UV process unevenness (e.g., unevenness of external conditions such as light, heat, stress, etc.). At the same time, the UV irradiation intensity in the UV2 step should be reduced to avoid or reduce negative effects, such as reliability degradation, image sticking, etc.

In the application of the PSA type liquid crystal display, it was found that not all liquid crystal compositions could be perfectly matched with the polymerizable compound, and there may be problems of residual incompletely polymerized polymerizable compound after UV1 and UV2 treatment, slow pre-tilt angle angulation speed, etc. Meanwhile, the liquid crystal composition is not good in intersolubility with a polymerizable compound, so that the rigidity of a polymer network formed after polymerization is poor, the structure of the polymer network is changed when the PSA type liquid crystal display element continuously displays the same pattern for a long time, the pre-tilt angle of liquid crystal molecules is changed, and the situation of poor display is caused.

Meanwhile, with the development of display technology, the display quality requirements of the LCD in the industry are more strict, especially in the TV industry, the size of the TV is generally increased, the LCD generation line is also increased, and the difficulty of the manufacturing process of the large-size LCD panel is also obviously increased. Therefore, how to ensure and improve the display quality is an urgent problem to be solved. In order to solve this problem, in addition to continuously optimizing the panel manufacturing process, continuous development of liquid crystal materials is also one of the effective means, and especially for PSA type liquid crystal displays, the selection of liquid crystal compositions to be used in combination with polymerizable compounds is a research focus.

Currently, problems common in the production of PSA type liquid crystal displays include residue or removal of polymerizable compounds, stability of pre-tilt angle, and the like. In the PSA type LCD, if the polymer particles are too large and the polymer particles are not uniform in the UV1 and UV2 processes, the polymer will be unevenly distributed, resulting in the "broken bright spots" of the PSA type LCD. Furthermore, after polymerizing the polymerizable compound by applying UV1 radiation and UV2 radiation to produce a pre-tilt angle, a small amount of unreacted polymerizable compound may polymerize in an uncontrolled manner after the display is manufactured, affecting the quality of the display. For example, residual polymerizable compounds polymerize under the influence of UV light from the environment or backlight illumination, and after a number of addressing periods in the on display areas, the pretilt angle changes and the transmittance changes, while the pretilt angle and transmittance remain unchanged in the non-on display areas, thereby creating an "image sticking" effect. It is therefore desirable that during the production of liquid crystal displays of the PSA type the polymerizable compounds polymerize as completely as possible and that the residual polymerizable compounds can react in a controlled manner, the faster the polymerization speed, the more advantageous it is to achieve this desire. Furthermore, it is also desirable that the change in the pre-tilt angle is small after a number of addressing periods have elapsed.

In addition, the conventional polymerizable compounds have high melting points and relatively limited solubility in common liquid crystal compositions, and often precipitate from the liquid crystal compositions. Meanwhile, the polymerizable compound has a possibility of self-polymerization, so that its solubility in the liquid crystal composition is further deteriorated. Therefore, it is generally necessary to introduce a liquid crystal composition in which a polymerizable compound is dissolved at a low temperature to reduce the risk of self-polymerization of the polymerizable compound, which puts higher demands on the solubility of the polymerizable compound in the liquid crystal composition, particularly on having good solubility at a low temperature.

Furthermore, the conventional polymerizable compounds form large humps (bump) after polymerization, easily aggregate into dots, have large fluctuation in pretilt angle, and require long-term irradiation to ensure complete reaction of the polymer. These problems are not ideal for displays. The prior art is developing, but the problems of slow angulation, long UV2 time and high residue still exist.

Therefore, it is important to develop a liquid crystal composition having a faster polymerization rate, a smaller bump formed after polymerization, less residue, a shorter UV time, and a better solubility.

Disclosure of Invention

In view of the disadvantages of the prior art, an object of the present invention is to provide a liquid crystal composition having advantages of high polymerization speed, small bump formed after polymerization, short UV time, less residue, and good miscibility, and a PSA-type liquid crystal display device having more excellent quality can be provided by using the liquid crystal composition, and a liquid crystal display device comprising the same.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the present invention provides a liquid crystal composition comprising a combination of a first component and a second component;

the first component comprises at least one polymerizable compound of formula I:

the second component comprises 1-20% by mass of a compound of formula II:

and

20-50% by mass of a compound of formula III:

wherein, Y ₁ 、Y ₂ 、Y ₃ 、Y ₄ 、Y ₅ 、Y ₆ 、Y ₇ 、Y ₈ 、Y ₉ 、Y ₁₀ 、Y ₁₁ And Y ₁₂ Each independently represents-H, halogen, -CN, -Sp ₅ -P ₅ An unsubstituted or halogenated, linear or branched alkyl group containing from 1 to 5 (e.g. 1, 2,3, 4 or 5) carbon atoms, an unsubstituted or halogenated, linear or branched alkoxy group containing from 1 to 4 (e.g. 1, 2,3 or 4) carbon atoms, and at least two (e.g. 2,3 or 4, etc.) of which represent-OCH ₃ 。

P ₁ 、P ₂ And P ₅ Each independently represents a polymerizable group.

Sp ₁ 、Sp ₂ And Sp ₅ Each independently represents a single bond or a spacer group.

R ₁ 、R ₂ 、R ₃ And R ₄ Each independently represents a straight or branched alkyl group containing 1 to 12 (e.g., 1, 2,3, 4, 5, 6, 7, 8, 9, 10, 11 or 12) carbon atoms,

At least two-CH which are not adjacent to one or more of the straight chain or branched chain alkyl containing 1 to 12 carbon atoms ₂ -can be independently replaced by-CH = CH-, -C ≡ C-, -O-, -S-, -CO-O-, or-O-CO-.

X ₁ 、X ₂ 、X ₃ And X ₄ Each independently represents-H or halogen, and at least one represents halogen.

n represents 0 or 1.

In the present invention, the halogen includes fluorine, chlorine, bromine, iodine, or the like; the same meanings are given below in relation to the same descriptions.

In the invention, the terms of '8230' \ 8230 '; substitution' which can be respectively and independently replaced or not replaced, namely, replaced or not replaced, belong to the protection scope of the invention; "can be respectively and independently substituted by \8230 \ 8230;" can be substituted by \ "in the same way; also, the positions of "substitution" and "substitution" are arbitrary.

In the invention, short straight lines at one side or two sides of a group represent access bonds and do not represent methyl; for example

Short straight line on the left side of-CN->

-CH = CH-short straight lines on both sides.

In the liquid crystal composition provided by the invention, the first component containing the polymerizable compound shown in the formula I is a polymerizable component, and the polymerizable component and the second component (non-polymerizable component) containing the compound shown in the formula II and the compound shown in the formula III in specific contents cooperate with each other to endow the liquid crystal composition with higher polymerization speed and angular velocity, and the liquid crystal composition has the advantages of smaller bump formed after polymerization, lower surface roughness, less residue and better low-temperature intersolubility, so that the liquid crystal composition is used as a liquid crystal material with good comprehensive performance, and can provide a PSA type liquid crystal display device with excellent quality.

In a preferred embodiment, the content of the compound of formula II is preferably adjusted such that the liquid crystal composition comprising the same has a faster polymerization speed and angular velocity, less polymer surface roughness, less polymer residue, and better low temperature storage stability.

The mass percentage of the compound of formula II in the second component is 1-20%, and may be, for example, 2%, 3%, 5%, 7%, 9%, 10%, 11%, 13%, 15%, 17%, or 19%, and the specific values therebetween, which are not intended to be exhaustive for the purpose of brevity and clarity, are not intended to limit the invention to the specific values encompassed by the scope disclosed herein.

In a preferred embodiment, the content of the compound of formula III is preferably adjusted such that the liquid crystal composition comprising the same has a faster polymerization speed and angular velocity, less polymer surface roughness, less polymer residue, and better low temperature storage stability.

The mass percentage of the compound of formula III in the second component is 20-50%, for example, 22%, 25%, 28%, 30%, 32%, 35%, 38%, 40%, 42%, 45% or 48%, and the specific values therebetween are not exhaustive for brevity and conciseness.

In a preferred embodiment, Y is ₁ 、Y ₂ 、Y ₃ 、Y ₄ 、Y ₅ 、Y ₆ 、Y ₇ 、Y ₈ 、Y ₉ 、Y ₁₀ 、Y ₁₁ And Y ₁₂ Each independently represents-H, -F, -Cl, -OCH ₃ 、-CH ₃ or-Sp ₅ -P ₅ And at least two (e.g., 2,3, or 4, etc.) represent-OCH ₃ 。

In a preferred technical scheme, the two-OCH ₃ Linked to adjacent benzene rings and corresponding Y _m The difference in m values of 2, 4 or 6; m represents an integer of 1 to 12, for example m represents 1, 2,3, 4, 5,6. 7, 8, 9, 10, 11 or 12.

In the present invention, said Y is ₁ -Y ₁₂ At least two of them represent-OCH ₃ I.e. -OCH ₃ The number of (a) can be 2,3, 4 or 5, etc.; wherein, two are-OCH ₃ Satisfies that "connected to the adjacent benzene rings, and the corresponding Y _m The difference in m of (2) may be 2, 4 or 6'.

In the present invention, the "adjacent benzene rings" means two benzene rings connected by a single bond, that is, Y ₁ In the benzene ring and Y ₅ In which the benzene rings are adjacent benzene rings, Y ₅ In the benzene ring and Y ₉ The benzene ring is adjacent benzene ring.

In the present invention, "the two-OCH ₃ Linked to adjacent benzene rings and corresponding Y _m Combinations of m values of 2, 4 or 6 "illustratively include: y is ₁ And Y ₅ 、Y ₁ And Y ₇ 、Y ₂ And Y ₆ 、Y ₂ And Y ₈ 、Y ₃ And Y ₇ 、Y ₃ And Y ₅ 、Y ₄ And Y ₈ 、Y ₄ And Y ₆ 、Y ₅ And Y ₉ 、Y ₅ And Y ₁₁ 、Y ₆ And Y ₁₀ 、Y ₆ And Y ₁₂ 、Y ₇ And Y ₁₁ 、Y ₇ And Y ₉ 、Y ₈ And Y ₁₂ 、Y ₈ And Y ₁₀ 。

In the present invention, the polymerizable group is a group suitable for polymerization (e.g., radical polymerization, ionic bond polymerization, polyaddition, or polycondensation), or a group suitable for addition or condensation on the polymer main chain. For chain polymerization, polymerizable groups comprising-C = C-or-C ≡ C-are particularly preferred, and oxetane or epoxy groups are particularly preferred for ring-opening polymerization.

In a preferred embodiment, said P ₁ 、P ₂ And P ₅ Each independently represent

/>

or-SH, more preferably->

The short straight lines to the right of the above groups all represent access bonds and do not represent methyl groups.

In the present invention, the term "spacer" is known to those skilled in the art and is described in the literature (e.g., "Definitions of basic relationships to low-molar and polymer liquid crystals (IUPAC Recommendations 2001)", barLo et al, pure appl. Chem.,2001, 73 (5), p.888). As used herein, the term "spacer group" means a flexible group that links a mesogenic group and a polymerizable group in a polymerizable compound. Typical spacer groups are for example- (CH) ₂ ) _p -、-(CH ₂ ) _p -O-、-(CH ₂ ) _p -O-CO-、-(CH ₂ ) _p -CO-O-、-(CH ₂ ) _p -O-CO-O-、-(CH ₂ CH ₂ O) _q -CH ₂ CH ₂ -、-(CH ₂ CH ₂ S) _q -CH ₂ CH ₂ -、-(CH ₂ CH ₂ NH) _q -CH ₂ CH ₂ -、-CR ⁰ R ¹ -(CH ₂ ) _p -or- (SiR) ⁰ R ¹ -O) _p -; wherein p represents an integer of 1 to 12; q represents an integer of 1 to 3; r ⁰ And R ¹ Each independently represents-H, a straight or branched alkyl group having 1 to 12 carbon atoms, or a cycloalkyl group having 3 to 12 carbon atoms. A particularly preferred spacer group is- (CH) ₂ ) _p -、-(CH ₂ ) _p -O-、-(CH ₂ ) _p -O-CO-、-(CH ₂ ) _p -CO-O-、-(CH ₂ ) _p -O-CO-O-or-CR ⁰ R ¹ -(CH ₂ ) _p -。

Preferably, said Sp ₁ 、Sp ₂ And Sp ₅ Each independently represents a single bond, - (CH) ₂ ) _p -、-(CH ₂ ) _p -O-、-(CH ₂ ) _p -O-CO-、-(CH ₂ ) _p -CO-O-、-(CH ₂ ) _p -O-CO-O-、-(CH ₂ CH ₂ O) _q -CH ₂ CH ₂ -、-(CH ₂ CH ₂ S) _q -CH ₂ CH ₂ -、-(CH ₂ CH ₂ NH) _q -CH ₂ CH ₂ -、-CR ⁰ R ¹ -(CH ₂ ) _p -or- (SiR) ⁰ R ¹ -O) _p -；

Wherein R is ⁰ And R ¹ Each independently represents-H, a straight or branched alkyl group containing 1 to 12 (e.g., 1, 2,3, 4, 5, 6, 7, 8, 9, 10, 11, or 12) carbon atoms, a cycloalkyl group containing 3 to 12 (e.g., 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12) carbon atoms.

p represents an integer of 1 to 12, and may be, for example, 1, 2,3, 4, 5, 6, 7, 8, 9, 10, 11 or 12.

q represents an integer of 1 to 3, for example 1, 2 or 3.

In a preferred embodiment, the polymerizable compound of formula I is selected from the group consisting of:

/>

/>

and

wherein, Y ₁ '、Y ₂ '、Y ₃ '、Y ₄ '、Y ₇ '、Y ₈ '、Y ₁₁ ' and Y ₁₂ ' independently of one another, -F, -Cl, -CH ₃ or-Sp ₅ -P ₅ 。

In a preferred embodiment, the content of the polymerizable compound of formula I in the liquid crystal composition is 0.01-2.0% by mass, for example, 0.02%, 0.05%, 0.08%, 0.1%, 0.3%, 0.5%, 0.7%, 0.9%, 1.0%, 1.1%, 1.3%, 1.5%, 1.7% or 1.9%, and the specific values between the above values are limited by space and for brevity, the invention is not exhaustive of the specific values included in the range.

In a preferred embodiment, the compound of formula II is selected from the group consisting of:

/>

and

in a preferred embodiment, R is ₁ And R ₂ Each independently represents a straight chain alkyl group having 1 to 6 (e.g., 1, 2,3, 4, 5, or 6) carbon atoms, a straight chain alkoxy group having 1 to 6 (e.g., 1, 2,3, 4, 5, or 6) carbon atoms, or a straight chain alkoxy group having 2 to 6 (e.g., 2,3, 4, 5, or 6) carbonsLinear alkenyl of atoms.

In a preferred embodiment, R is ₁ Represents a straight chain alkyl group containing 1 to 6 (e.g., 1, 2,3, 4, 5, or 6) carbon atoms; the R is ₂ Denotes a straight-chain alkyl group having 1 to 6 (e.g. 1, 2,3, 4, 5 or 6) carbon atoms or a straight-chain alkoxy group having 1 to 6 (e.g. 1, 2,3, 4, 5 or 6) carbon atoms.

In a preferred embodiment, R is ₃ And R ₄ Each independently represents a straight chain alkyl group having 1 to 6 (e.g., 1, 2,3, 4, 5, or 6) carbon atoms, a straight chain alkenyl group having 2 to 6 (e.g., 2,3, 4, 5, or 6) carbon atoms, or a straight chain alkoxy group having 1 to 6 carbon atoms.

The linear alkenyl group in the present invention preferably has a structure represented by any one of the formulae (V1) to (V9), and particularly preferably has the formula (V1), the formula (V2), the formula (V8), or the formula (V9).

Wherein denotes the attachment site of the group.

In a preferred embodiment, the compound of formula III is selected from the group consisting of:

and

wherein R is ₃ ' and R ₄ ' each ofIndependently represent a straight chain alkyl group containing 1-6 (e.g., 1, 2,3, 4, 5, or 6) carbon atoms.

In a preferred embodiment, the first component further comprises at least one polymerizable compound of formula IV:

wherein, K ₁ 、K ₂ 、K ₃ 、K ₄ 、K ₅ 、K ₆ 、K ₇ 、K ₈ 、K ₉ 、K ₁₀ 、K ₁₁ And K ₁₂ Each independently represents-H, halogen, -CN, -Sp ₆ -P ₆ Unsubstituted or halogenated, straight-chain or branched alkyl groups containing 1 to 5 (e.g. 1, 2,3, 4 or 5) carbon atoms.

P ₃ 、P ₄ And P ₆ Each independently represents a polymerizable group.

Sp ₃ 、Sp ₄ And Sp ₆ Each independently represents a single bond or a spacer group.

Z ₁ And Z ₂ Each independently represents a single bond-O-, -S-, -CO-) -CO-O-, -O-CO-O-, -CH ₂ O-、-OCH ₂ -、-CH ₂ S-、-SCH ₂ -、-CF ₂ O-、-OCF ₂ -、-CF ₂ S-、-SCF ₂ -、-(CH ₂ ) _u -、-CF ₂ CH ₂ -、-CH ₂ CF ₂ -、-(CF ₂ ) _u -、-CH＝CH-、-CF＝CF-、-CH＝CF-、-CF＝CH-、-C≡C-、-CH＝CH-CO-O-、-O-CO-CH＝CH-、-CH ₂ CH ₂ -CO-O-、-O-CO-CH ₂ CH ₂ -or-CR ^p R ^q -；R ^p And R ^q Each independently represents-H or a straight or branched alkyl group containing 1 to 12 (e.g. 1, 2,3, 4, 5, 6, 7, 8, 9, 10, 11 or 12) carbon atoms, and u represents an integer of 1 to 4 and may be, for example, 1, 2,3 or 4.

n ₁ Represents 0, 1 or2; when n is ₁ When representing 2, a ring

Same or different, Z ₂ The same or different.

Preferably, the polymerizable compound of formula IV is selected from the group consisting of:

/>

/>

/>

and

wherein, K ₁ 、K ₂ 、K ₃ 、K ₄ 、K ₅ 、K ₆ 、K ₇ 、K ₈ 、K ₉ 、K ₁₀ And K ₁₂ Each independently represents halogen, -CN, -CH ₃ or-Sp ₆ -P ₆ 。

In a preferred embodiment, said P ₃ 、P ₄ And P ₆ Each independently represent

or-SH, more preferably->

In a preferred embodiment, said Sp ₃ 、Sp ₄ And Sp ₆ Each independently represents a single bond, - (CH) ₂ ) _s -、-(CH ₂ ) _s -O-、-(CH ₂ ) _s -O-CO-、-(CH ₂ ) _s -CO-O-、-(CH ₂ ) _s -O-CO-O-、-(CH ₂ CH ₂ O) _t -CH ₂ CH ₂ -、-(CH ₂ CH ₂ S) _t -CH ₂ CH ₂ -、-(CH ₂ CH ₂ NH) _t -CH ₂ CH ₂ -、-CR ² R ³ -(CH ₂ ) _s -or- (SiR) ² R ³ -O) _s -。

Wherein R is ² And R ³ Each independently represents-H, a straight or branched alkyl group containing 1 to 12 (e.g., 1, 2,3, 4, 5, 6, 7, 8, 9, 10, 11, or 12) carbon atoms, a cycloalkyl group containing 3 to 12 (e.g., 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12) carbon atoms.

s represents an integer from 1 to 12 and may be, for example, 1, 2,3, 4, 5, 6, 7, 8, 9, 10, 11 or 12; t represents an integer of 1 to 3, for example 1, 2 or 3.

In a preferred embodiment, the content of the polymerizable compound of formula IV in the liquid crystal composition is 0.01-2.0% by mass, for example, 0.02%, 0.05%, 0.08%, 0.1%, 0.3%, 0.5%, 0.7%, 0.9%, 1.0%, 1.1%, 1.3%, 1.5%, 1.7% or 1.9%, and the specific values between the above values are limited by space and for brevity, the invention is not exhaustive of the specific values included in the range.

In a preferred embodiment, the second component further comprises at least one compound of formula M:

wherein R is _M1 And R _M2 Each independently represents a straight or branched alkyl group having 1 to 12 (e.g., 1, 2,3, 4, 5, 6, 7, 8, 9, 10, 11 or 12) carbon atoms,

At least two-CH which are not adjacent to one or more of the straight chain or branched chain alkyl groups containing 1 to 12 carbon atoms ₂ -may be independently replaced by-CH = CH-, -C.ident.C-, -O-, -CO-O-or-O-CO-, respectively.

Ring (C)

Ring->

And ring->

Each independently represents->

Is/are>

Or at least two-CHs which are not adjacent to each other ₂ -may be replaced by-O-, and one or at least two of the ring single bonds may be replaced by a double bond; is/are>

May be replaced by-N = and at most one-H may be substituted by halogen.

Z _M1 And Z _M2 Each independently represents a single bond-CO-O-) -O-CO-, -CH ₂ O-、-OCH ₂ -、-C≡C-、-CH＝CH-、-CH ₂ CH ₂ -or- (CH) ₂ ) ₄ -。

n _M Represents 0, 1 or 2.

When n is _M When represents 0, a ring

And ring->

Is not simultaneously greater than or equal to>

When n is _M When 1 or 2 is represented, the compound of formula M does not contain a terphenyl structure (i.e., does not contain a substituted or unsubstituted moiety

Structure).

When n is _M When representing 2, a ring

Same or different, Z _M2 The same or different.

In a preferred embodiment, the compound of formula M is selected from the group consisting of:

/>

/>

and

in a preferred embodiment, R is _M1 And R _M2 Each independently represents a straight chain alkyl group containing 1 to 8 (e.g., 1, 2,3, 4, 5, 6, 7, or 8) carbon atoms, a straight chain alkoxy group containing 1 to 8 (e.g., 1, 2,3, 4, 5, 6, 7, or 8) carbon atoms, or a straight chain alkenyl group containing 2 to 8 (e.g., 2,3, 4, 5, 6, 7, or 8) carbon atoms.

In a preferred embodiment, the compound of formula M is selected from any one of the compounds of formula M-1, the compounds of formula M-5, the compounds of formula M-11, the compounds of formula M-12, the compounds of formula M-15, the compounds of formula M-23, the compounds of formula M-25, the compounds of formula M-26 or the compounds of formula M-27 or a combination of at least two thereof.

In a preferred embodiment, the content of the compound of formula M in the second component is preferably adjusted such that the liquid crystal composition comprising the same has a faster polymerization speed and angular velocity, less polymer surface roughness, less polymer residue, and better low temperature storage stability.

In a preferred embodiment, the content of the compound of formula M in the second component is 0.1-50% by mass, for example, 0.3%, 0.5%, 0.8%, 1%, 3%, 5%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, 40%, 42%, 45% or 48%, and the specific values therebetween are not exhaustive, and for brevity and clarity, the invention is not intended to be exhaustive.

In a preferred embodiment, the second component further comprises at least one compound of formula N:

wherein R is _N1 And R _N2 Each independently represents a straight or branched alkyl group containing 1 to 12 (e.g., 1, 2,3, 4, 5, 6, 7, 8, 9, 10, 11 or 12) carbon atoms,

Ring(s)

And ring>

Each independently represents->

The described

Of one or at least two-CH ₂ -may be replaced by-O-, a single bond in one or at least two ringsMay be replaced by a double bond; is/are>

May be replaced by-N = in one or at least two rings; one or at least two of the foregoing groups-H may be substituted by-F, -Cl or-CN.

Z _N1 And Z _N2 Each independently represents a single bond-CO-O-, -O-CO-, -CH ₂ O-、-OCH ₂ -、-CH＝CH-、-C≡C-、-CH ₂ CH ₂ -、-CF ₂ CF ₂ -、-(CH ₂ ) ₄ -、-CF ₂ O-or-OCF ₂ -。

L _N1 And L _N2 Each independently represents-H, halogen, unsubstituted or halogenated straight chain alkyl groups containing 1 to 3 (e.g. 1, 2 or 3) carbon atoms.

n _N1 Represents 0, 1, 2 or 3,n _N2 Represents 0 or 1, and 0. Ltoreq. N _N1 +n _N2 ≤3。

When 2 is less than or equal to n _N1 +n _N2 At 3 or less, the compound of formula N does not contain a terphenyl structure (i.e., does not contain a substituted or unsubstituted moiety

Structure).

When n is _N1 When represents 2 or 3, a ring

Same or different, Z _N1 The same or different.

In a preferred embodiment, the compound of formula N is selected from the group consisting of:

/>

/>

/>

and

in a preferred embodiment, R is _N1 And R _N2 Each independently represents a straight chain alkyl group containing 1 to 6 (e.g., 1, 2,3, 4, 5, or 6) carbon atoms, a straight chain alkoxy group containing 1 to 6 (e.g., 1, 2,3, 4, 5, or 6) carbon atoms, or a straight chain alkenyl group containing 2 to 6 (e.g., 2,3, 4, 5, or 6) carbon atoms.

In a preferred embodiment, the compound of formula N is selected from any one of a compound of formula N-2, a compound of formula N-3, a compound of formula N-5, a compound of formula N-6, a compound of formula N-10, a compound of formula N-11, a compound of formula N-12, a compound of formula N-19, a compound of formula N-21 or a compound of formula N-23, or a combination of at least two thereof.

In a preferred embodiment, the second component comprises at least one compound of formula N-2 and/or a compound of formula N-5 in order to achieve a faster angulation speed, lower polymer residue, less roughness and longer low temperature storage time.

In a preferred embodiment, the second component comprises at least one compound of formula N-3 and/or a compound of formula N-6 in order to achieve faster angulation speed, lower polymer residue, less roughness, and longer low temperature storage time.

In a preferred embodiment, the second component comprises at least one compound of formula N-10 and/or a compound of formula N-12 in order to achieve faster angulation speed, lower polymer residue, less roughness, and longer low temperature storage time.

In a preferred embodiment, the content of the compound of formula N is preferably adjusted such that the liquid crystal composition comprising the same has a faster angular velocity, lower polymer residue, less roughness, and longer low temperature storage time.

In a preferred embodiment, the content of the compound of formula N in the second component is 0.1-60% by mass, for example, 0.3%, 0.5%, 0.8%, 1%, 3%, 5%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, 40%, 42%, 45%, 48%, 50%, 52%, 55% or 58%, and the specific points between the above points are not limited to space and for brevity, and the invention is not exhaustive.

In a preferred embodiment, the second component further comprises at least one compound of formula B:

wherein R is _B1 And R _B2 Each independently represents-H, halogen, straight or branched chain alkyl containing 1-12 (e.g. 1, 2,3, 4, 5, 6, 7, 8, 9, 10, 11 or 12) carbon atoms; at least two-CH which are not adjacent to one or more of the straight chain or branched chain alkyl groups containing 1 to 12 carbon atoms ₂ -may be independently replaced by-CH = CH-, -C ≡ C-, -S-, -O-, -CO-O-, or-O-CO-, respectively; one or at least two of the foregoing groups-H may each be independently substituted with-F or-Cl; r _B1 And R _B2 Are all connected to the ring structure through a C atom.

Ring (C)

And ring->

Each independently represents->

Is/are>

Or at least two-CHs that are not adjacent to each other ₂ -may be replaced by-O-, one or at least two of the ring single bonds may be replaced by double bonds; is/are>

May be replaced by-N = in one or at least two rings; one or at least two of the foregoing groups-H may be replaced by-F, -Cl, -CN, -CH ₃ or-OCH ₃ And (4) substitution.

Z _B1 And Z _B2 Each independently represents a single bond, -O-, or-S-, -CO-O-, -O-CO-, -CH ₂ O-、-OCH ₂ -、-CH＝CH-、-C≡C-、-CH ₂ CH ₂ -、-CF ₂ CF ₂ -、-(CH ₂ ) ₄ -、-CF ₂ O-or-OCF ₂ -。

Y _B1 And Y _B2 Each independently represents-H, halogen, unsubstituted or halogenated straight chain alkyl groups containing 1 to 3 (e.g. 1, 2 or 3) carbon atoms, unsubstituted or halogenated straight chain alkoxy groups containing 1 to 3 (e.g. 1, 2 or 3) carbon atoms.

X _B represents-O-, -S-) -CO-, -CF ₂ -, -NH-or-NF-.

n _B1 And n _B2 Each independently represents 0, 1 or 2; when n is _B1 When representing 2, a ring

Same or different, Z _B1 Same or different when n _B2 When represents 2, ring->

Same or different, Z _B2 The same or different.

In a preferred embodiment, the compound of formula B is selected from the group consisting of:

/>

and

wherein, Y _B3 And Y _B4 Each independently represents-H, -F, -Cl, -CN, -CH ₃ or-OCH ₃ 。

In a preferred embodiment, the mass percentage of the compound of formula B in the second component is 0.1-30%, for example, 0.3%, 0.5%, 0.8%, 1%, 3%, 5%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, or 28%.

In a preferred embodiment, the second component further comprises at least one compound of formula A-1 and/or formula A-2;

wherein R is _A1 And R _A2 Each independently represents a straight or branched alkyl group having 1 to 12 (e.g., 1, 2,3, 4, 5, 6, 7, 8, 9, 10, 11 or 12) carbon atoms,

At least two-CH which are not adjacent to one or more of the straight chain or branched chain alkyl groups containing 1 to 12 carbon atoms ₂ -may be independently replaced by-CH = CH-, -C ≡ C-, -O-, -CO-O-, or-O-CO-, respectively; one or at least two of the foregoing groups-H may each be independently substituted with-F or-Cl.

Ring (C)

Ring->

Ring->

And ring->

Each independently represent

Is/are>

Or at least two-CHs which are not adjacent to each other ₂ -may be replaced by-O-, one or at least two of the ring single bonds may be replaced by double bonds; is/are>

May be replaced by-N = in one or at least two rings; one or at least two of the foregoing groups-H may be substituted by-F, -Cl or-CN. />

Z _A11 、Z _A21 And Z _A22 Each independently represents a single bond, -CH ₂ CH ₂ -、-CF ₂ CF ₂ -、-CO-O-、-O-CO-、-O-CO-O-、-CH＝CH-、-CF＝CF-、-CH ₂ O-or-OCH ₂ -。

L _A11 、L _A12 、L _A13 、L _A21 And L _A22 Each independently represents-H, unsubstituted or halogenated straight chain alkyl containing 1 to 3 (e.g. 1, 2 or 3) carbon atoms, halogen.

X _A1 And X _A2 Each independently represents halogen, haloalkyl containing 1 to 5 (e.g. 1, 2,3, 4 or 5) carbon atoms, haloalkoxy containing 1 to 5 (e.g. 1, 2,3, 4 or 5) carbon atoms, haloalkenyl containing 2 to 5 (e.g. 2,3, 4 or 5) carbon atoms, haloalkenyloxy containing 2 to 5 (e.g. 2,3, 4 or 5) carbon atoms.

n _A11 And n _A2 Each independently represents 0, 1, 2 or 3; when n is _A11 When represents 2 or 3, a ring

Same or different, Z _A11 The same or different; when n is _A2 Ring/is based on 2 or 3>

Same or different, Z _A21 The same or different.

n _A12 Represents 1 or 2; when n is _A12 When representing 2, a ring

The same or different.

In a preferred embodiment, the compound of formula a-1 is selected from the group consisting of:

/>

/>

and

wherein R is _A1 Represents a straight or branched alkyl group containing 1 to 8 (e.g. 1, 2,3, 4, 5, 6, 7 or 8) carbon atoms; at least two-CH which are not adjacent to one or more of the straight chain or branched chain alkyl groups containing 1 to 8 carbon atoms ₂ -may be independently replaced by-CH = CH-, -C ≡ C-, -O-, -CO-O-, or-O-CO-, respectively; one or at least two of the foregoing groups-H may each be independently substituted with-F or-Cl.

R _v And R _w Each independently represents-CH ₂ -or-O-.

L _A11 、L _A12 、L _A11 '、L _A12 '、L _A14 、L _A15 And L _A16 Each independently represents-H or-F.

L _A13 And L _A13 ' independently of each other represents-H or-CH ₃ 。

X _A1 represents-F, -CF ₃ 、-OCF ₃ or-CH ₂ CH ₂ CH＝CF ₂ 。

v and w each independently represent 0 or 1.

In a preferred embodiment, the content of the compound of formula a-1 in the second component is 0.1-50% by mass, for example, 0.3%, 0.5%, 0.8%, 1%, 3%, 5%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, 40%, 42%, 45%, or 48% by mass.

In a preferred embodiment, the compound of formula a-2 is selected from the group consisting of:

/>

/>

and

wherein R is _A2 Represents a straight or branched alkyl group containing 1 to 8 (e.g. 1, 2,3, 4, 5, 6, 7 or 8) carbon atoms; at least two-CH which are not adjacent to one or more of the straight chain or branched chain alkyl groups containing 1 to 8 carbon atoms ₂ -can be independently replaced by-CH = CH-, -C ≡ C-, -O-, -CO-O-, or-O-CO-; one or at least two of the foregoing groups-H may each be independently substituted with-F or-Cl.

L _A21 、L _A22 、L _A23 、L _A24 And L _A25 Each independently represents-H or-F.

X _A2 represents-F, -CF ₃ 、-OCF ₃ or-CH ₂ CH ₂ CH＝CF ₂ 。

In a preferred embodiment, the content of the compound of formula a-2 in the second component is 0.1-50% by mass, for example, 0.3%, 0.5%, 0.8%, 1%, 3%, 5%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, 40%, 42%, 45%, or 48% by mass.

In addition to the above compounds, the liquid crystal composition of the present invention may contain a conventional nematic liquid crystal, smectic liquid crystal, cholesteric liquid crystal, dopant, antioxidant, ultraviolet absorber, infrared absorber, polymerizable monomer, light stabilizer, and the like.

Possible dopants which are preferably added to the liquid crystal composition of the invention are shown below:

and->

In some embodiments of the invention, the dopant comprises 0% to 5% by weight of the liquid crystal composition; preferably, the dopant accounts for 0.01-1% of the liquid crystal composition by weight.

Further, additives such as an antioxidant and a light stabilizer used in the liquid crystal composition of the present invention are preferably as follows:

/>

/>

wherein n represents a positive integer of 1 to 12.

Preferably, the light stabilizer is selected from the group consisting of the light stabilizers shown below:

in some embodiments of the invention, the light stabilizer comprises from 0% to 5% by weight of the total liquid crystal composition; preferably, the light stabilizer accounts for 0.01 to 1 percent of the total weight of the liquid crystal composition; more preferably, the light stabilizer is present in an amount of 0.01 to 0.1% by weight based on the total weight of the liquid crystal composition.

The liquid crystal composition of the present invention can be polymerized even in the absence of a polymerization initiator, but may contain a polymerization initiator in order to promote the polymerization. As the polymerization initiator, benzoin ethers, benzophenones, acetophenones, benzil ketals, acylphosphine oxides and the like can be exemplified.

The liquid crystal composition of the present invention can be imparted with liquid crystal alignment ability by polymerization of a polymerizable compound in the liquid crystal composition, and the amount of transmitted light in a liquid crystal display device is controlled by utilizing birefringence in the liquid crystal composition.

As a method for polymerizing the polymerizable compound, a method of polymerizing by irradiating active energy rays such as ultraviolet rays or electron beams is preferable in order to increase the polymerization speed. When ultraviolet light is used, either a polarized light source or an unpolarized light source may be used. In addition, when the polymerization is performed in a state where the liquid crystal composition is sandwiched between two substrates, at least the substrate on the irradiation surface side must have appropriate transparency to the active energy ray. Further, polymerization may be performed by polymerizing only a specific portion using a mask at the time of light irradiation, and then changing the orientation state of the unpolymerized portion by changing the conditions such as an electric field, a magnetic field, or temperature, and further irradiating an active energy ray. In particular, when ultraviolet exposure is performed, it is preferable to perform ultraviolet exposure while applying a voltage to the liquid crystal composition.

The temperature at the time of irradiation with active energy rays such as ultraviolet rays or electron beams is preferably within a temperature range in which the liquid crystal state of the liquid crystal composition of the present invention is maintained. The polymerization is preferably carried out at temperatures close to room temperature, i.e.from 15 to 35 ℃. As the lamp for generating ultraviolet rays, a metal halide lamp, a high pressure mercury lamp, an ultra high pressure mercury lamp, or the like can be used. The wavelength of the ultraviolet light to be irradiated is preferably ultraviolet light having a wavelength outside the absorption wavelength range of the liquid crystal composition, and is preferably used by blocking the ultraviolet light as necessary. The intensity of the ultraviolet ray to be irradiated is preferably 0.1 to 50mW/cm ² . When the ultraviolet rays are irradiated, the intensity thereof may be changed, and the time for irradiating the ultraviolet rays is appropriately selected according to the intensity of the irradiated ultraviolet rays, preferably 10 to 600 seconds.

As used herein, the terms "tilt" and "tilt angle" will be understood as the tilt alignment of liquid crystal molecules with respect to the surface of a liquid crystal cell in a liquid crystal display device (in the present invention, a PSA type liquid crystal display device is preferred). The tilt angle means an average angle (< 90 °) formed between the longitudinal molecular axis of the liquid crystal molecules (liquid crystal director) and the surface of the outer plate of the liquid crystal cell. A low value of the tilt angle (i.e. a large angle deviating from 90 °) corresponds to a large tilt.

In a second aspect, the present invention provides a liquid crystal display device comprising the liquid crystal composition according to the first aspect.

Compared with the prior art, the invention has the following beneficial effects:

the liquid crystal composition provided by the invention has faster polymerization speed and angular velocity through the mutual cooperation of the first component containing the polymerizable compound shown in the formula I and the second component containing the compound shown in the formula II and the compound shown in the formula III in specific contents, has smaller bump after polymerization, lower surface roughness, better pretilt angle stability, lower residual quantity after polymerization and good low-temperature stability, effectively improves the problems of 'broken bright spots', 'image sticking' and display unevenness in a PSA type liquid crystal display device, and can provide the PSA type liquid crystal display device with better quality.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

For convenience of expression, in each of the following examples and comparative examples, the group structures of the components in the liquid crystal composition are represented by the codes listed in Table 1:

TABLE 1

Take the example of a compound of the formula:

the structural formula is represented by the code listed in table 1, and can be expressed as: nCC1OWO2; wherein C represents a1, 4-cyclohexylene group, 1O represents a methyleneoxy group, W represents a2, 3-difluoro-1, 4-phenylene group, O2 represents an ethoxy group, n represents the number of carbon atoms of the left-end alkyl group, for example, n is "3", that is, the alkyl group is an n-propyl group.

The abbreviations for the test items in the following examples and comparative examples are as follows:

cp clearing Point (nematic phase-isotropic phase transition temperature, ° C)

Δ n optical anisotropy (589nm, 25 ℃ C.)

Delta epsilon dielectric anisotropy (1kHz, 25 ℃ C.)

K ₁₁ Splay elastic constant (25 ℃ C.)

K ₃₃ Flexural modulus of elasticity constant (25 ℃ C.)

γ ₁ Rotational viscosity (mPa. Multidot.s, 25 ℃ C.)

Ra surface roughness (nm)

LTS (-20 ℃ C.) Low temperature storage time (-20 ℃ C.)

PTA pretilt angle (°)

RM residual Polymer residue (UV 2, 90 min)

Wherein, cp: measured by an MP70 melting point apparatus;

Δ n: testing with Abbe refractometer under sodium lamp (589 nm) at 25 deg.C;

Δε：Δε＝ε _∥ -ε _⊥ wherein epsilon _∥ Is the dielectric constant, ε, parallel to the molecular axis _⊥ For the dielectric constant perpendicular to the molecular axis, test conditions: a VA type test box with the temperature of 25 ℃ and the frequency of 1kHz and the thickness of 5.8 mu m;

K ₁₁ and K ₃₃ : using an LCR instrument and a VA test box to test the C-V curve of the liquid crystal and calculating; and (3) testing conditions are as follows: VA type test cell, cell thickness 5.8 μm, V =0.1-20V;

LTS (-20 ℃): placing the liquid crystal medium in a glass bottle, storing at constant temperature of-20 ℃, and recording the time when crystal precipitation is observed; 20Day OK means that it can be used after 20 days; 17Day NG means that crystals precipitated after 17 days;

γ ₁ : testing by using an LCM-2 type liquid crystal physical property evaluation system; and (3) testing conditions are as follows: 25 ℃, 160-260V and the thickness of the test box is 20 mu m;

ra: after the liquid crystal composition is polymerized by UV illumination to form an angle of 88 degrees, washing off liquid crystal molecules, and then testing the morphology roughness of the polymerized polymer layer by using an Atomic Force Microscope (AFM);

PTA: filling liquid crystal into a VA type test box (the box thickness is 3.5 mu m) by using a crystal rotation method, applying voltage (15V, 60Hz), and simultaneously irradiating by using ultraviolet light UV1 to ensure that polymerizable compounds are polymerized to form a pre-tilt angle PTA1, and then continuously irradiating ultraviolet light UV2 to the liquid crystal composition with the formed pre-tilt angle PTA1 to eliminate residual polymerizable compounds in the PTA1 state, wherein the pre-tilt angle formed by the polymerizable compounds is PTA2; the polymerization speed of the polymerizable compound was examined by comparing the magnitude of the pretilt angle formed when UV1 was irradiated for the same time (the smaller the pretilt angle, the faster the polymerization speed) or the time required to form the same pretilt angle (the shorter the time required, the faster the polymerization speed);

polymer residue: after 60min of UV2 application, the liquid crystals eluted from the liquid crystal test cell were examined by High Performance Liquid Chromatography (HPLC) with the content of polymerizable compounds as polymer residue.

The compounds used in the following examples can be synthesized by known methods or obtained commercially. These synthesis techniques are conventional and the resulting liquid crystal compositions are tested for compliance with electronic compound standards.

Liquid crystal compositions were prepared according to the formulation of each liquid crystal composition in the following examples. The liquid crystal composition is prepared by a conventional method in the art, such as mixing in a prescribed ratio by heating, ultrasonic wave, suspension, etc.

Examples 1 to 8 and comparative examples 1 to 7

The components and performance parameters of the liquid crystal composition LC1 (second component) for comparative examples 1 to 3, the liquid crystal composition LC2 (second component) for examples 1 to 4 and comparative examples 4 to 6, and the liquid crystal composition LC4 for comparative example 7 are shown in table 2:

TABLE 2

The components and performance parameters of the liquid crystal composition LC3 (second component) for examples 5-8 are shown in Table 3:

TABLE 3

Examples 1-13 provide the components of the liquid crystal compositions shown in table 4, the amounts of each component being in "parts by weight":

TABLE 4

	LC2	LC3	I-1	I-2-1	I-19	I-10	I-11-1	IV-1-1
									Example 1	100		0.3
Example 2	100			0.3
									Example 3	100				0.02		0.28
Example 4		100	0.3
									Example 5		100		0.3
Example 6		100	0.02					0.28
									Example 7		100		0.02			0.28
Example 8	100		0.02					0.28
									Example 9	100			0.02			0.28
Example 10		100			0.3
									Example 11		100				0.3
Example 12		100					0.02	0.28
									Example 13	100				0.3

Comparative examples 1 to 7 components of liquid crystal compositions are provided as shown in table 5, and the amount of each component is in "parts by weight":

TABLE 5

Wherein the compound formulae referred to in tables 4 and 5 are as follows:

the results of the performance tests of the liquid crystal compositions provided in examples 1 to 13 and comparative examples 1 to 7 are shown in Table 6:

TABLE 6

As can be seen from the comparison between examples 1-3 and comparative examples 1-3, 4, the liquid crystal composition of the present application, through the optimization of the structure and content of the liquid crystal compound in the second component, the liquid crystal composition of the present invention forms smaller PTA1 after applying UV1 for different time, the polymerization speed and the angular velocity are faster, the residual amount after polymerization is smaller, and the surface roughness of the polymer layer is smaller, the low temperature storage time is longer, and the low temperature stability is better.

As can be seen from the comparison of examples 1-3 and comparative example 5, the liquid crystal composition of the present application, by optimizing the structure of the polymerizable compound in the first component, allows the liquid crystal composition of the present invention to form smaller PTA1 after applying UV1 for different periods of time, faster polymerization speed and angular velocity, smaller residual amount after polymerization, and smaller surface roughness of the polymer layer, longer low temperature storage time and better low temperature stability.

Therefore, the first component containing the polymerizable compound shown in the formula I and the second component containing the compound shown in the formula II and the compound shown in the formula III are cooperated with each other, so that the polymerization speed and the angular velocity of the liquid crystal composition are higher, the residual quantity after polymerization is lower (55-77 ppm), the surface roughness of a polymer layer is smaller (10.3-10.8 nm), the liquid crystal composition can be stably stored for more than 19 days at the low temperature of 20 ℃, the low-temperature stability is excellent, and a PSA type liquid crystal display device with more excellent quality can be provided.

The applicant states that the present invention is illustrated by the above examples of a liquid crystal composition of the present invention and a liquid crystal display device comprising the same, but the present invention is not limited to the above examples, that is, it is not meant that the present invention must be implemented by relying on the above examples. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.

Claims

1. A liquid crystal composition, comprising a combination of a first component and a second component;

the first component comprises at least one polymerizable compound of formula I:

the second component comprises 1-20% by mass of a compound of formula II:

and

20-50% by mass of a compound of formula III:

wherein, Y ₁ 、Y ₂ 、Y ₃ 、Y ₄ 、Y ₅ 、Y ₆ 、Y ₇ 、Y ₈ 、Y ₉ 、Y ₁₀ 、Y ₁₁ And Y ₁₂ Each independently represents-H, halogen, -CN, -Sp ₅ -P ₅ An unsubstituted or halogenated straight-chain or branched alkyl group having 1 to 5 carbon atoms, an unsubstituted or halogenated straight-chain or branched alkoxy group having 1 to 4 carbon atoms, and at least two of them represent-OCH ₃ ；

P ₁ 、P ₂ And P ₅ Each independently represents a polymerizable group;

Sp ₁ 、Sp ₂ and Sp ₅ Each independently represents a single bond or a spacer group;

R ₁ 、R ₂ 、R ₃ and R ₄ Each independently represents a linear or branched alkyl group having 1 to 12 carbon atoms,

At least two-CH which are not adjacent to one or more of the straight chain or branched chain alkyl groups containing 1 to 12 carbon atoms ₂ -can be independently replaced by-CH = CH-, -C ≡ C-, -O-, -S-, -CO-O-, or-O-CO-;

X ₁ 、X ₂ 、X ₃ and X ₄ Each independently represents-H or halogen, and at least one represents halogen;

n represents 0 or 1.

2. The liquid crystal composition of claim 1, wherein the polymerizable compound of formula I is selected from the group consisting of:

/>

/>

and

3. The liquid crystal composition according to claim 1 or 2, wherein the polymerizable compound of formula I in the liquid crystal composition is contained in an amount of 0.01 to 2.0% by mass.

4. The liquid crystal composition according to any one of claims 1 to 3, wherein the compound of formula II is selected from the group consisting of:

and

5. the liquid crystal composition of any of claims 1 to 4, further comprising at least one polymerizable compound of formula IV in the first component:

wherein, K ₁ 、K ₂ 、K ₃ 、K ₄ 、K ₅ 、K ₆ 、K ₇ 、K ₈ 、K ₉ 、K ₁₀ 、K ₁₁ And K ₁₂ Each independently represents-H, halogen, -CN, -Sp ₆ -P ₆ Unsubstituted or halogenated, linear or branched alkyl groups containing from 1 to 5 carbon atoms;

P ₃ 、P ₄ and P ₆ Each independently represents a polymerizable group;

Sp ₃ 、Sp ₄ and Sp ₆ Each independently represents a single bond or a spacer group;

Z ₁ and Z ₂ Each independently represents a single bond-O-, -S-, -CO-) -CO-O-, -O-CO-O-, -CH ₂ O-、-OCH ₂ -、-CH ₂ S-、-SCH ₂ -、-CF ₂ O-、-OCF ₂ -、-CF ₂ S-、-SCF ₂ -、-(CH ₂ ) _u -、-CF ₂ CH ₂ -、-CH ₂ CF ₂ -、-(CF ₂ ) _u -、-CH＝CH-、-CF＝CF-、-CH＝CF-、-CF＝CH-、-C≡C-、-CH＝CH-CO-O-、-O-CO-CH＝CH-、-CH ₂ CH ₂ -CO-O-、-O-CO-CH ₂ CH ₂ -or-CR ^p R ^q -；R ^p And R ^q Each independently represents-H or a linear or branched alkyl group containing 1 to 12 carbon atoms, u represents an integer of 1 to 4;

n ₁ represents 0, 1 or 2; when n is ₁ When represents 2, a ring

Same or different, Z ₂ The same or different;

/>

/>

/>

and

wherein, K ₁ 、K ₂ 、K ₃ 、K ₄ 、K ₅ 、K ₆ 、K ₇ 、K ₈ 、K ₉ 、K ₁₀ And K ₁₂ Each independently represents halogen, -CN, -CH ₃ or-Sp ₆ -P ₆ ；

Preferably, the polymerizable compound of formula IV in the liquid crystal composition is 0.01-2.0% by mass.

6. Liquid crystal composition according to any one of claims 1 to 5, characterized in that said second component further comprises at least one compound of formula M:

wherein R is _M1 And R _M2 Each independently represents a straight or branched alkyl group having 1 to 12 carbon atoms,

At least two-CH which are not adjacent to one or more of the straight chain or branched chain alkyl containing 1 to 12 carbon atoms ₂ -can be independently replaced by-CH = CH-, -C ≡ C-, -O-, -CO-O-, or-O-CO-;

ring (C)

Ring->

And ring>

Each independently represents->

Is/are>

May be replaced by-N = and at most one-H may be substituted by halogen;

Z _M1 and Z _M2 Each independently represents a single bond-CO-O-) -O-CO-, -CH ₂ O-、-OCH ₂ -、-C≡C-、-CH＝CH-、-CH ₂ CH ₂ -or- (CH) ₂ ) ₄ -；

n _M Represents 0, 1 or 2;

when n is _M When represents 0, a ring

And ring->

Is not simultaneously greater than or equal to>

When n is _M When represents 1 or 2, the compound of formula M does not contain a terphenyl structure;

when n is _M When representing 2, a ring

Same or different, Z _M2 The same or different.

7. The liquid crystal composition of claim 6, wherein the compound of formula M is selected from the group consisting of:

/>

and

preferably, the mass percentage of the compound of formula M in the second component is 0.1-50%.

8. Liquid crystal composition according to any one of claims 1 to 7, characterized in that said second component further comprises at least one compound of formula N:

wherein R is _N1 And R _N2 Each independently represents a linear or branched alkyl group having 1 to 12 carbon atoms,

At least two-CH which are not adjacent to one or more of the straight chain or branched chain alkyl groups containing 1 to 12 carbon atoms ₂ -may be independently replaced by-CH = CH-, -C ≡ C-, -O-, -CO-O-, or-O-CO-, respectively;

ring (C)

And ring->

Each independently represents->

Is/are>

Of one or at least two-CH ₂ -may be replaced by-O-, one or at least two of the ring single bonds may be replaced by double bonds; the above-mentioned

May be replaced by-N = in one or at least two rings; one or at least two of the foregoing groups-H may be substituted by-F, -Cl or-CN;

Z _N1 and Z _N2 Each independently represents a single bond-CO-O-, -O-CO-, -CH ₂ O-、-OCH ₂ -、-CH＝CH-、-C≡C-、-CH ₂ CH ₂ -、-CF ₂ CF ₂ -、-(CH ₂ ) ₄ -、-CF ₂ O-or-OCF ₂ -；

L _N1 And L _N2 Each independently represents-H, halogen, unsubstituted or halogenated straight chain alkyl groups containing from 1 to 3 carbon atoms;

n _N1 represents 0, 1, 2 or 3,n _N2 Represents 0 or 1, and 0. Ltoreq. N _N1 +n _N2 ≤3；

When 2 is less than or equal to n _N1 +n _N2 When the content is less than or equal to 3, the compound of the formula N does not contain a terphenyl structure;

when n is _N1 When represents 2 or 3, a ring

Same or different, Z _N1 The same or different.

9. The liquid crystal composition of claim 8, wherein the compound of formula N is selected from the group consisting of:

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and

preferably, the mass percentage of the compound of formula N in the second component is 0.1-60%.

10. A liquid crystal display device comprising the liquid crystal composition according to any one of claims 1 to 9.