CN115926808B

CN115926808B - Liquid crystal composition and liquid crystal display device comprising same

Info

Publication number: CN115926808B
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: 2023-09-15
Anticipated expiration: 2041-05-31
Also published as: CN115926808A

Abstract

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

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

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

The PSA type liquid crystal display mode is to add a small amount (typically < 1wt%, for example, 0.3 wt%) of one or more polymerizable compounds to a liquid crystal composition, and can ensure that after the liquid crystal composition is filled into a liquid crystal cell, liquid crystal molecules are polymerized or crosslinked in situ in a state having an initial alignment with or without applying a voltage between electrodes, thereby achieving fixing of the alignment of the liquid crystal molecules. With the continuous development of the PSA-type liquid crystal display element, it is applied to various conventional liquid crystal display devices, such as PSA-VA, PSA-OCB, PSA-IPS, PSA-FFS, PSA-TN type liquid crystal displays. In a PSA-type liquid crystal display, a liquid crystal composition containing a polymerizable compound is located between two substrates, each of which 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 an active matrix display, individual pixels are addressed by integrated nonlinear active elements (e.g., transistors); in the case of passive matrix displays, the individual pixels are usually addressed according to the known multiplexing method.

After filling the liquid crystal composition into the display device, the polymerizable compound contained in the liquid crystal composition is generally polymerized or crosslinked in situ by UV photopolymerization, which is achieved by exposing the liquid crystal composition to UV irradiation, and preferably simultaneously 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 pretilt 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 types, the polymerization of the polymerizable compound is preferably carried out with the application of a voltage; for the PSA-IPS type liquid crystal display, voltage may be applied or not applied, and it is preferable that voltage not be applied.

In the production method of the PSA-type liquid crystal display, UV photopolymerization is achieved by the following 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 a voltage is applied to the electrode structure to create a pretilt angle. The more preferred polymerizable compounds should produce smaller pretilt angles in the same time or the same pretilt angles (i.e., faster angulation speed) in shorter UV1 irradiation times to improve production efficiency, shorten tact time at mass production, and reduce cost. Meanwhile, the faster the angulation speed of the polymerizable compound is, the more favorable the polymerizable compound is to be completely polymerized, thereby reducing polymer residues. To increase the angular velocity, it is preferred to use UV1 radiation of shorter wavelength; to increase the voltage holding ratio (Voltage Holding Ratio, VHR), UV1 radiation of longer wavelength is preferably used. Therefore, it is often difficult to combine a faster angulation speed with a higher voltage holding ratio.

In the second step (hereinafter referred to as "UV2 step"), the liquid crystal composition is exposed to UV irradiation without applying a voltage to the electrode structure to ensure thorough polymerization of the residual polymerizable compound that is not polymerized in the UV1 step. It is desirable that the pre-tilt angle is changed as little as possible after the UV2 step to reduce the possibility of uneven display of the PSA type lcd due to UV process non-uniformity (e.g., uneven 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 to avoid reliability degradation, image sticking, etc.

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

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 TV size is generally increased, the LCD generation line is also increased, and the manufacturing process difficulty of the large-size LCD panel is also obviously increased. Therefore, how to secure and improve the display quality is a problem to be solved. In order to solve this problem, besides the continuous optimization of the panel manufacturing process, the continuous development of liquid crystal materials is one of the effective means, and especially for PSA-type liquid crystal displays, the selection of liquid crystal compositions used in combination with polymerizable compounds is a research hotspot.

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

In addition, existing polymerizable compounds have high melting points and have relatively limited solubility in commonly used liquid crystal compositions, often separating out from the liquid crystal composition. Meanwhile, the polymerizable compound has a possibility of self-polymerization, further deteriorating its solubility in the liquid crystal composition. 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 places higher demands on the solubility of the polymerizable compound in the liquid crystal composition, particularly good solubility at a low temperature.

Moreover, the conventional polymerizable compounds form large bumps (bumps) after polymerization, are easily aggregated into spots, have large fluctuation of pretilt angles, and require long irradiation to ensure complete reaction of the polymer. These problems are not ideal for displays. The prior art is developed, but the problems of slow angulation, long UV2 time and high residue still exist.

Therefore, development of a liquid crystal composition with higher polymerization speed, smaller bulb formed after polymerization, less residue, shorter UV time and better solubility is the focus of research in the field.

Disclosure of Invention

In view of the shortcomings of the prior art, the invention aims to provide a liquid crystal composition and a liquid crystal display device comprising the same, wherein the liquid crystal composition has the advantages of high polymerization speed, small bulb formed after polymerization, short UV time, less residue and good intersolubility, and a PSA type liquid crystal display element with more excellent quality can be provided by using the liquid crystal composition.

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% of a compound of formula II:

and

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

wherein 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, halogen, -CN, -Sp ₅ -P ₅ Unsubstituted or halogenated straight-chain or branched alkyl having 1 to 5 (e.g., 1, 2, 3, 4, or 5) carbon atoms, unsubstituted or halogenated straight-chain or branched alkoxy having 1 to 4 (e.g., 1, 2, 3, or 4) carbon atoms, and at least two (e.g., 2, 3, or 4, etc.) 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 is ₄ Each independently represents a linear 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 groups, one or not adjacent, of said straight or branched alkyl groups having 1 to 12 carbon atoms ₂ Can be independently and individually represented by-ch=ch-, -C.ident.C-, -O-, -S-, -CO-O-or-O-CO-substitution.

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 following description is referred to in the same sense.

In the present invention, "can be replaced by … …" independently means that it may or may not be replaced, that is, replaced or not replaced, which falls within the scope of the present invention; "may each be independently substituted by … …" is the same; also, the positions of "substitution" and "substitution" are arbitrary.

In the invention, short straight lines at one side or two sides of the group represent access bonds and do not represent methyl; for example -short straight line to the left of CN, +.>-ch=ch-short straight line on both sides.

The first component containing the polymerizable compound shown in the formula I is a polymerizable component, and the first component and the second component (non-polymerized component) containing the compound shown in the formula II and the compound shown in the formula III are mutually cooperated to endow the liquid crystal composition with higher polymerization speed and angulation speed, and the formed lamp after polymerization is smaller, has lower surface roughness and lower residue, and has 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 so that the liquid crystal composition comprising it has a faster polymerization rate and angulation rate, 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%, for example, 2%, 3%, 5%, 7%, 9%, 10%, 11%, 13%, 15%, 17% or 19%, and the specific values between the above values are limited in space and for simplicity, the invention is not intended to be exhaustive of the specific values included in the range.

In a preferred embodiment, the content of the compound of formula III is preferably adjusted so that the liquid crystal composition comprising it has a faster polymerization rate and angulation rate, 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 between the above values, are for brevity and for simplicity, the invention is not intended to be exhaustive of the specific values included in the range.

In a preferred embodiment, the 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, -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 embodiment, the two-OCH' s ₃ Is connected with adjacent benzene rings and corresponding Y _m The difference between the 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 invention, the Y ₁ -Y ₁₂ At least two of them represent-OCH ₃ I.e. -OCH ₃ The number of (2), 3, 4 or 5, etc.; wherein, two-OCH ₃ The connection position of (C) satisfies the conditions of' being connected to adjacent benzene rings and corresponding Y _m The difference between the m values of (2), (4) or (6').

In the present invention, the "adjacent benzene ring" means two benzene rings linked by a single bond, i.e., Y ₁ Benzene ring and Y ₅ The benzene ring is adjacent benzene ring, Y ₅ Benzene ring and Y ₉ The benzene ring is adjacent benzene ring.

In the present invention, the conditions "the two-OCH are satisfied ₃ Is connected with adjacent benzene rings and corresponding Y _m The combination of m values with a difference of 2, 4 or 6 "illustratively comprises: y is Y 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, addition polymerization, or polycondensation), or a group suitable for addition or condensation on a polymer main chain. For chain polymerization, polymerizable groups containing-C=C-or-C≡C-are particularly preferred, and for ring-opening polymerization oxetane or epoxy groups are particularly preferred.

In a preferred embodiment, the P ₁ 、P ₂ And P ₅ Each independently represents or-SH, further 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 group" is known to those skilled in the art and is described in the literature (e.g. "Definitions of basic terms relating to low-molarMass and polymer liquid crystals (IUPAC Recommendations 2001) ", bar et al, pure appl.chem.,2001, 73 (5), page 888). As used herein, the term "spacer group" means a flexible group that connects 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 is R ⁰ And R is 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, the 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 is ¹ Each independently represents-H, containingStraight or branched alkyl of 1 to 12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12) carbon atoms, cycloalkyl 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 is ₁ '、Y ₂ '、Y ₃ '、Y ₄ '、Y ₇ '、Y ₈ '、Y ₁₁ ' and Y ₁₂ ' each independently represents-F, -Cl, -CH ₃ or-Sp ₅ -P ₅ 。

In a preferred embodiment, the mass percentage of the polymerizable compound of formula I in the liquid crystal composition is 0.01-2.0%, 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 in length and for the sake of brevity, the invention is not exhaustive of the specific values comprised 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 is ₂ Each independently represents a linear alkyl group containing 1 to 6 (e.g., 1, 2, 3, 4, 5, or 6) carbon atoms, a linear alkoxy group containing 1 to 6 (e.g., 1, 2, 3, 4, 5, or 6) carbon atoms, or a linear alkenyl group containing 2 to 6 (e.g., 2, 3, 4, 5, or 6) carbon atoms.

In a preferred embodiment, R is ₁ Represents a linear alkyl group containing 1 to 6 (e.g., 1, 2, 3, 4, 5, or 6) carbon atoms; the R is ₂ Represents a linear alkyl group having 1 to 6 (e.g. 1, 2, 3, 4, 5 or 6) carbon atoms or a linear 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 is ₄ Each independently represents a linear alkyl group containing 1 to 6 (e.g., 1, 2, 3, 4, 5, or 6) carbon atoms, a linear alkenyl group containing 2 to 6 (e.g., 2, 3, 4, 5, or 6) carbon atoms, or a linear alkoxy group containing 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 is formula (V1), formula (V2), formula (V8) or formula (V9).

Wherein, represents 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 independently represents a straight chain alkyl group containing 1 to 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 is 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 containing 1 to 5 (e.g. 1, 2, 3)Linear or branched alkyl of one, 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-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 is ^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, which may be 1, 2, 3 or 4, for example.

n ₁ Represents 0, 1 or 2; when n is ₁ When 2 is represented, the ringIdentical 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 is 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, the P ₃ 、P ₄ And P ₆ Each independently represents or-SH, further preferably The short straight lines to the right of the above groups all represent access bonds and do not represent methyl groups.

In a preferred embodiment, the 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 is ³ Each independently represents-H, a linear 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 of 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 mass percentage of the polymerizable compound of formula IV in the liquid crystal composition is 0.01-2.0%, 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 in length and for brevity, and the invention is not intended to be 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 is _M2 Each independently represents a linear 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 groups, one or not adjacent, of said straight or branched alkyl groups having 1 to 12 carbon atoms ₂ Can be independently and individually substituted by-CH=CH-, -C≡C-, -O-, -CO-O-, or-O-CO-substitution.

Ring(s)Ring->And (C) a ring->Each independently represents-> Said->At least two-CH of one or not adjacent ₂ -can be replaced by-O-, single bonds in one or at least two rings can be replaced by double bonds; said->In which-ch=can be replaced by-n=and at most one-H can 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 Representing 0, 1 or 2.

When n is _M When 0 is represented, the ringAnd (C) a ring->Not at the same time +.>

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 unsubstitutedStructure).

When n is _M When 2 is represented, the ringIdentical 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 is _M2 Each independently represents a linear alkyl group containing 1 to 8 (e.g., 1, 2, 3, 4, 5, 6, 7, or 8) carbon atoms, a linear alkoxy group containing 1 to 8 (e.g., 1, 2, 3, 4, 5, 6, 7, or 8) carbon atoms, or a linear 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 or a combination of at least two of a compound of formula M-1, a compound of formula M-5, a compound of formula M-11, a compound of formula M-12, a compound of formula M-15, a compound of formula M-23, a compound of formula M-25, a compound of formula M-26, or a compound of formula M-27.

In a preferred embodiment, the content of the compound of formula M in the second component is preferably adjusted so that the liquid crystal composition comprising it has a faster polymerization rate and angulation rate, a smaller polymer surface roughness, a smaller polymer residue and a better low temperature storage stability.

In a preferred embodiment, the mass percentage of the compound of formula M in the second component is 0.1-50%, 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 between the above values, are not intended to be exhaustive or for reasons of brevity.

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

Wherein R is _N1 And R is _N2 Each independently represents a group comprising 1 to 12 (e.g., 1, 2, 3, 4, 5, 6, 7, etc.),Linear or branched alkyl of 8, 9, 10, 11 or 12) carbon atoms, At least two-CH groups, one or not adjacent, of said straight or branched alkyl groups having 1 to 12 carbon atoms ₂ Can be independently and individually substituted by-CH=CH-, -C≡C-, -O-, -CO-O-, or-O-CO-substitution.

Ring(s)And (C) a ring->Each independently represents->The saidOne or at least two-CH ₂ -can be replaced by-O-, single bonds in one or at least two rings can be replaced by double bonds; said->-ch=in one or at least two rings may be replaced by-n=in one or more rings; one or at least two of the foregoing groups-H may be substituted with-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, the compounds of formula N do not contain a terphenyl structure (i.e., do not contain a substituted or unsubstitutedStructure).

When n is _N1 When 2 or 3 is represented, the ringIdentical 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 is _N2 Each independently represents a linear alkyl group containing 1 to 6 (e.g., 1, 2, 3, 4, 5, or 6) carbon atoms, a linear alkyl group containing 1 to 6 (e.g., 1, 2, 3, 4, 5, or 6) carbon atomsAlkoxy or straight chain alkenyl 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 or a combination of at least two 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.

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 obtain 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 obtain 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 the formula N-10 and/or a compound of the formula N-12 in order to obtain a faster angulation speed, a lower polymer residue, a smaller roughness and a longer low temperature storage time.

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

In a preferred embodiment, the mass percentage of the compound of formula N in the second component is 0.1-60%, 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 values between the above values are limited in length and for brevity, and the invention is not intended to exhaustively list the specific values included in the range.

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

Wherein R is _B1 And R is _B2 Each independently represents-H, halogen, a linear 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 groups, one or not adjacent, of said straight or branched alkyl groups having 1 to 12 carbon atoms ₂ -may each be independently replaced by-ch=ch-, -c≡c-, -S-, -O-, -CO-O-, or-O-CO-; one or at least two of the foregoing groups, -H, may each independently be substituted with-F or-Cl; r is R _B1 And R is _B2 Are all connected with the ring structure through C atoms.

Ring(s)And (C) a ring->Each independently represents The saidAt least two-CH of one or not adjacent ₂ -can be replaced by-O-, single bonds in one or at least two rings can be replaced by double bonds; said-> One or at least of-ch=in both rings can be replaced by-n=; one or at least two of the foregoing groups-H may be replaced by-F, -Cl, -CN, -CH ₃ or-OCH ₃ And (3) substitution.

Z _B1 And Z _B2 Each independently represents a single bond, -O-, -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 linear alkyl groups containing 1 to 3 (e.g., 1, 2, or 3) carbon atoms, unsubstituted or halogenated linear 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 2 is represented, the ringIdentical or different, Z _B1 Identical or different, when n _B2 When 2 is indicated, the ring->Identical 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 is _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%, etc.

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 is _A2 Each independently represents a linear 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 groups, one or not adjacent, of said straight or branched alkyl groups having 1 to 12 carbon atoms ₂ -may each 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.

Ring(s)Ring->Ring->And (C) a ring->Each independently representsThe said At least two-CH of one or not adjacent ₂ -can be replaced by-O-, single bonds in one or at least two rings can be replaced by double bonds; said->-ch=in one or at least two rings may be replaced by-n=in one or more rings; one or at least two of the foregoing groups-H may be substituted with-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 groups containing 1 to 3 (e.g., 1, 2 or 3) carbon atoms, halogen.

X _A1 And X _A2 Each independently represents halogen, haloalkyl having 1 to 5 (e.g., 1, 2, 3, 4, or 5) carbon atoms, haloalkoxy having 1 to 5 (e.g., 1, 2, 3, 4, or 5) carbon atoms, haloalkenyl having 2 to 5 (e.g., 2, 3, 4, or 5) carbon atoms, haloalkenoxy having 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 2 or 3 is represented, the ringIdentical or different, Z _A11 The same or different; when n is _A2 When 2 or 3 is indicated, the ring->Identical or different, Z _A21 The same or different. />

n _A12 Represents 1 or 2; when n is _A12 When 2 is represented, the 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 linear 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 groups, one or not adjacent, of said straight or branched alkyl groups having 1 to 8 carbon atoms ₂ Can be independently and respectively-CH=CH--c≡c-, -O-, -CO-O-, or-O-CO-substitution; one or at least two of the foregoing groups-H may each be independently substituted with-F or-Cl.

R _v And R is _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 ' each independently represents-H or-CH ₃ 。

X _A1 representing-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 mass percentage of the compound of formula a-1 in the second component is 0.1-50%, 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%, etc.

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

And

wherein R is _A2 Represents a linear 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 groups, one or not adjacent, of said straight or branched alkyl groups having 1 to 8 carbon atoms ₂ -may each 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 representing-F, -CF ₃ 、-OCF ₃ or-CH ₂ CH ₂ CH＝CF ₂ 。

In a preferred embodiment, the mass percentage of the compound of formula a-2 in the second component is 0.1-50%, 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%, etc.

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

Possible dopants preferably added to the liquid crystal composition of the present 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 comprises 0.01% to 1% by weight of the liquid crystal composition.

The additives such as antioxidants and light stabilizers used in the liquid crystal composition of the present invention are preferably the following:

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 0% to 5% by weight of the total weight of the liquid crystal composition; preferably, the light stabilizer comprises 0.01-1% by weight of the total weight of the liquid crystal composition; more preferably, the light stabilizer comprises 0.01 to 0.1% by weight of 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 further contain a polymerization initiator for the purpose of promoting the polymerization. Examples of the polymerization initiator include benzoin ethers, benzophenones, acetophenones, benzil ketals, and acylphosphine oxides.

The liquid crystal composition of the present invention can be imparted with liquid crystal aligning 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.

In order to accelerate the polymerization rate, the polymerizable compound is preferably polymerized by irradiation with an active energy ray such as ultraviolet rays or electron beams. When ultraviolet rays are used, a polarized light source may be used, or an unpolarized light source may be used. In addition, when polymerization is performed in a state in which the liquid crystal composition is sandwiched between two substrates, at least the substrate on the irradiation surface side must have appropriate transparency with respect to the active energy rays. Further, it is also possible to polymerize only a specific portion by using a mask at the time of light irradiation, then change the orientation state of the unpolymerized portion by changing the conditions such as an electric field, a magnetic field, or a temperature, and further irradiate an active energy ray to polymerize. 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 in 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 a temperature close to room temperature (i.e., 15-35 ℃). As the lamp that generates 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 irradiated ultraviolet light is preferably ultraviolet light having a wavelength outside the absorption wavelength region of the liquid crystal composition, and is preferably used by blocking ultraviolet light if necessary. The intensity of the irradiated ultraviolet rays is preferably 0.1-50mW/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 cell surface in a liquid crystal display device (in the present invention, a PSA-type liquid crystal display device is preferred). The tilt angle represents the average angle (< 90 °) formed between the longitudinal molecular axis of the liquid crystal molecules (liquid crystal director loss) 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 deg.) corresponds to a large tilt.

In a second aspect, the present invention provides a liquid crystal display device comprising a 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 the advantages that 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 with specific content, the liquid crystal composition has the advantages of higher polymerization speed and higher angulation speed, smaller bulb after polymerization, lower surface roughness, better pretilt angle stability, lower residual quantity after polymerization and good low-temperature stability, and effectively solves the problems of bright spot breakage, image viscosity, uneven display and the like in a PSA type liquid crystal display device, thereby providing the PSA type liquid crystal display device with better quality.

Detailed Description

The technical scheme of the invention is further described by the following specific embodiments. It will be apparent to those skilled in the art that the examples are merely to aid in understanding the invention and are not to be construed as a specific limitation thereof.

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

TABLE 1

Take as an example a compound of the formula:

the structural formula is represented by the codes listed in table 1, and can be expressed as follows: nCC1OWO2; wherein C represents a 1, 4-cyclohexylene group, 1O represents a methoxylene group, W represents a 2, 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, it means that the alkyl group is an n-propyl group.

The shorthand numbers of test items in the following examples and comparative examples are as follows:

cp clearing point (nematic phase-isotropic phase transition temperature, DEG C)

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

Dielectric anisotropy of delta epsilon (1 kHz,25 ℃ C.)

K ₁₁ Spring constant of splay (25 ℃ C.)

K ₃₃ Flexural spring constant (25 ℃ C.)

γ ₁ Rotational viscosity (mPa.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 instrument;

an: using Abbe refractometer under sodium light (589 nm) source, and testing at 25deg.C;

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

K ₁₁ and K ₃₃ : testing the C-V curve of the liquid crystal by using an LCR instrument and a VA test box and calculating; test conditions: VA-type test cell, cell thickness 5.8 μm, v=0.1-20V;

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

γ ₁ : the liquid crystal display is obtained by testing by using an LCM-2 liquid crystal physical property evaluation system; test conditions: 25 ℃, 160-260V and 20 mu m thick test box;

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

PTA: filling liquid crystal into a VA type test box (box thickness is 3.5 mu m) by using a crystal rotation method, applying voltage (15V, 60 Hz), simultaneously irradiating by using ultraviolet light UV1 to polymerize the polymerizable compound to form a pretilt angle PTA1, and continuously irradiating ultraviolet light UV2 to the liquid crystal composition with the pretilt angle PTA1 so as to eliminate the residual polymerizable compound in the PTA1 state, wherein the pretilt angle formed by the polymerizable compound is PTA2; the polymerization rate 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 rate) or the time required to form the same pretilt angle (the shorter the time required, the faster the polymerization rate);

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), wherein the content of polymerizable compounds was polymer residue.

The compounds used in the examples below may be synthesized by known methods or obtained commercially. These synthetic techniques are conventional and the resulting liquid crystal compositions are tested to meet electronic standards.

Liquid crystal compositions were prepared in accordance with the proportions of the respective liquid crystal compositions in the following examples. The liquid crystal composition is prepared by mixing the components according to a prescribed proportion by a conventional method in the art, such as heating, ultrasonic wave, suspension and the like.

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

Examples 5 to 8 the components and performance parameters of the liquid crystal composition LC3 (second component) are shown in table 3:

TABLE 3 Table 3

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

TABLE 4 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 1-7 components providing liquid crystal compositions are shown in table 5, the amounts of the components are in "parts by weight":

TABLE 5

Wherein the compounds referred to in tables 4 and 5 have the following structural formula:

the results of the performance test 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 is clear from the comparison of examples 1 to 3 and comparative examples 1 to 3 and 4, the liquid crystal composition of the present application, by optimizing the structure and content of the liquid crystal compound in the second component, has smaller PTA1 formed after the application of UV1 for different times, faster polymerization speed and angulation speed, smaller residual amount after polymerization, smaller surface roughness of the polymer layer, longer low-temperature storage time and better low-temperature stability.

As is clear from the comparison of examples 1 to 3 and comparative example 5, the liquid crystal composition of the present application makes PTA1 formed after UV1 is applied for different times smaller, polymerization speed and angulation speed are faster, residual amount after polymerization is smaller, and surface roughness of the polymer layer is smaller, low temperature storage time is longer, and low temperature stability is better by optimizing the structure of the polymerizable compound in the first component.

From this, it can be seen that the present application, by the mutual synergy of the first component comprising the polymerizable compound of formula I and the second component comprising the compound of formula II and the compound of formula III in specific amounts, makes the polymerization rate and angulation rate of the liquid crystal composition faster, the residual amount after polymerization is lower (55-77 ppm), the surface roughness of the polymer layer is smaller (10.3-10.8 nm), the polymer layer can be stably stored at 20 ℃ for 19 days or more, has excellent low temperature stability, and can provide a PSA type liquid crystal display device with more excellent quality.

The applicant states that the present invention is described by way of the above examples as 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, i.e., it is not meant that the present invention must be practiced in dependence upon the above examples. It should be apparent to those skilled in the art that any modification of the present invention, equivalent substitution of raw materials for the product of the present invention, addition of auxiliary components, selection of specific modes, etc., falls within the scope of the present invention and the scope of disclosure.

Claims

1. A liquid crystal composition, characterized in that the liquid crystal composition comprises 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% of a compound of formula II:

and

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

wherein 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, halogen, unsubstituted or halogenated straight or branched alkoxy groups having 1 to 4 carbon atoms, and at least two represent-OCH ₃ ；

P ₁ And P ₂ Each independently represents

Sp ₁ And Sp ₂ 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-or-CR ⁰ R ¹ -(CH ₂ ) _p -; p represents an integer of 1 to 12; q represents an integer of 1 to 3; r is R ⁰ Represents a linear or branched alkyl radical having 1 to 12 carbon atoms, R ¹ represents-H, a linear or branched alkyl group having 1 to 12 carbon atoms;

R ₁ 、R ₂ 、R ₃ and R is ₄ Each independently represents a linear or branched alkyl group having 1 to 12 carbon atoms,At least two-CH groups, one or not adjacent, of said straight or branched alkyl groups having 1 to 12 carbon atoms ₂ -may each 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;

the mass percentage of the polymerizable compound of the formula I in the liquid crystal composition is 0.01-2.0%.

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

and

wherein Y is ₁ '、Y ₂ '、Y ₃ '、Y ₄ '、Y ₇ '、Y ₈ '、Y ₁₁ ' and Y ₁₂ ' each independently represents-F, -Cl or-CH ₃ 。

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

and

R ₁ and R is ₂ Has the same limitations as claim 1.

4. The liquid crystal composition of claim 1, wherein the first component further comprises at least one polymerizable compound of formula IV:

Wherein K is 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 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-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 is ^q Each independently represents-H or a linear or branched alkyl group having 1 to 12 carbon atoms, u represents an integer of 2 to 4;

5. The liquid crystal composition of claim 4, wherein the polymerizable compound of formula IV is selected from the group consisting of:

and

wherein K is 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 ；

P ₃ 、P ₄ 、P ₆ 、Sp ₃ 、Sp ₄ 、Sp ₆ 、Z ₁ And Z ₂ Has the same limitations as claim 4.

6. The liquid crystal composition according to claim 4, wherein the mass percentage of the polymerizable compound of formula IV in the liquid crystal composition is 0.01 to 2.0%.

7. The liquid crystal composition of claim 1, wherein the second component further comprises at least one compound of formula M:

Wherein R is _M1 And R is _M2 Each independently represents a linear or branched alkyl group having 1 to 12 carbon atoms,At least two-CH groups, one or not adjacent, of said straight or branched alkyl groups having 1 to 12 carbon atoms ₂ -may each be independently replaced by-ch=ch-, -c≡c-, -O-, -CO-O-, or-O-CO-;

ring(s)Ring->And (C) a ring->Each independently represents-> Said->At least two-CH of one or not adjacent ₂ -can be replaced by-O-, single bonds in one or at least two rings can be replaced by double bonds; said->In which-ch=can be replaced by-n=and at most one-H can 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 1 or 2 is represented, the compound of formula M does not contain a terphenyl structure;

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

and

wherein R is _M1 And R is _M2 Has the same limitations as claim 7.

9. The liquid crystal composition according to claim 7, wherein the mass percentage of the compound of formula M in the second component is 0.1 to 50%.

10. The liquid crystal composition of claim 1, wherein the second component further comprises at least one compound of formula N:

wherein R is _N1 And R is _N2 Each independently represents a linear or branched alkyl group having 1 to 12 carbon atoms,At least two-CH groups, one or not adjacent, of said straight or branched alkyl groups having 1 to 12 carbon atoms ₂ -may each be independently replaced by-ch=ch-, -c≡c-, -O-, -CO-O-, or-O-CO-;

ring(s)And (C) a ring->Each independently represents->The saidOne or at least two-CH ₂ -can be replaced by-O-, single bonds in one or at least two rings can be replaced by double bonds; said->-ch=in one or at least two rings may be replaced by-n=in one or more rings; one or at least two of the foregoing groups-H may be substituted with-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 linear alkyl groups containing 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;

11. The liquid crystal composition according to claim 10, wherein the compound of formula N is selected from the group consisting of:

And

wherein R is _N1 And R is _N2 Has the same limitations as claim 10.

12. The liquid crystal composition according to claim 10, wherein the mass percentage of the compound of formula N in the second component is 0.1 to 60%.

13. A liquid crystal display device comprising the liquid crystal composition according to any one of claims 1 to 12.