TWI826484B - Compounds, liquid crystal compositions, liquid crystal display elements and liquid crystal displays - Google Patents

Abstract

The present invention relates to compounds, liquid crystal compositions, liquid crystal display elements and liquid crystal displays. The compound is a compound represented by formula I below. The liquid crystal composition of the present invention contains the compound represented by formula I. The compound represented by formula I of the present invention has the advantages of good miscibility with other compounds and good ultraviolet resistance. As a reactive mesogen (RM), it has the advantages of good miscibility, high polymerization activity (less monomer residue), and strong binding ability. It can not only be used as a self-alignment agent for liquid crystal compositions alone, but also as a vertical alignment material. Self-aligning agents copolymerized with other RMs for PSA (polymer-supported alignment) and PS (polymer-stabilized) mode liquid crystal compositions can avoid the PI process and simplify the process of liquid crystal display elements or liquid crystal displays. Improve production efficiency.

Description

Compounds, liquid crystal compositions, liquid crystal display elements and liquid crystal displays

The present invention belongs to the field of liquid crystal display technology, and more specifically, relates to a compound, a liquid crystal composition containing the compound, and a liquid crystal display element or liquid crystal display containing the compound or the liquid crystal composition.

The liquid crystal medium used in active matrix addressing display elements such as VA mode is not perfect. For example, the level of image retention is significantly worse than that of display elements with positive dielectric anisotropy, the response time is slower, and the driving voltage is relatively high. . At this time, some new VA display technologies have quietly emerged: PSVA technology realizes a wide viewing angle display mode similar to MVA/PVA, and also simplifies the CF process, thereby reducing the CF cost, increasing the aperture ratio, and also Get higher brightness and therefore higher contrast. In addition, since the entire liquid crystal has a pretilt angle, there is no domino delay phenomenon. A faster response time can be obtained while maintaining the same driving voltage, and the level of afterimage will not be affected. However, due to the dense distribution of Fine Slits in the pixels, electrodes, so if the width of the electrodes cannot be evenly distributed, uneven display may easily occur. Like UVVA technology, while maintaining the advantages of PSVA technology, since there is no Slit structure on the TFT side, the problem of uneven display caused by uneven pixel electrode widths has been improved. Although display elements are constantly developing, people are still committed to researching new liquid crystal compounds to continuously advance the performance of liquid crystal media and their application in display elements.

Polymerizable mesogenic units (RMs) are currently a very hot and important topic in the display industry. Their possible applications include polymer-stabilized alignment (PSA) liquid crystal displays, polymer-stabilized blue-phase (PS-BP) liquid crystal displays, and patterning. Retardation film (Pattern Retarder Film), etc.

The PSA principle is being applied in different typical LC displays, such as PSA-VA, PSA-OCB, PS-IPS/FFS and PS-TN. Taking the most widely used PSA-VA display as an example, the pretilt angle of the liquid crystal cell can be obtained through the PSA method, which has a positive impact on the response time. For PSA-VA displays, standard MVA or PVA pixel and electrode designs can be used, but if the electrode design is specially patterned on one side and not raised on the other end, production can be significantly simplified while making the display Get very good contrast and high light transmittance.

The prior art has found that LC mixtures and RMs still have some disadvantages in their application in PSA displays. For example, the panel manufacturing process requires coating of PI. Not only is the process complex, it affects the production capacity of the production line, but it also causes the emission of organic pollutants.

The object of the present invention is to provide a compound that can achieve self-alignment function, as well as a negative liquid crystal composition containing such a compound, and a liquid crystal display element or liquid crystal display containing the compound or liquid crystal composition, which is particularly suitable for monitors or TVs. Applications of PSVA liquid crystal compositions.

The compound of the present invention has the advantages of good miscibility with other compounds and good ultraviolet resistance. As a reactive mesogen (RM), it has the advantages of high polymerization activity (less monomer residue) and strong binding ability. It can not only be used as a self-alignment agent for liquid crystal compositions alone, but also as a vertical alignment material with other RMs. Copolymerization is used as a self-aligning agent for PSA (polymer-supported alignment) and (polymer-stabilized) PS-type liquid crystal compositions, which can avoid the PI process and improve production efficiency.

The liquid crystal composition of the present invention contains one or more compounds represented by formula I. Through the polymerization of the compounds represented by formula I, a layer of polymer with rough surface is spontaneously formed, which can serve as insulation of PI and vertical alignment of liquid crystal molecules. It can avoid the PI process, simplify the manufacturing process of liquid crystal display elements or liquid crystal displays, and improve production efficiency. In addition, the liquid crystal composition of the present invention has low viscosity, can achieve rapid response, and at the same time has moderate dielectric anisotropy Δε, moderate optical anisotropy Δn, and high stability against heat and light. The liquid crystal display element or liquid crystal display containing the liquid crystal composition has a wide nematic phase temperature range, suitable or high birefringence anisotropy Δn, very high resistivity, good ultraviolet resistance, and high Voltage holding rate and low vapor pressure.

In order to achieve the above object, the present invention provides a compound represented by the following formula I:

或環碸；R_W表示碳原子數為1-5的烷基；Sp¹、Sp²、Sp⁵各自獨立地表示單鍵或間隔基；Z₀表示單鍵、-O-、-S-、-CO-、-COO-、-OCO-、-OCOO-、-OCH₂-、-CH₂O-、-SCH₂-、-CH₂S-、-CF₂O-、-OCF₂-、-CF₂S-、-SCF₂-、-(CH₂)n₁-、-CF₂CH₂-、-CH₂CF₂-、-(CF₂)n₂-、-CH=CH-、-C≡C-、-CF=CF-、-CH=CH-COO-、-OCO-CH=CH-、-(CR_YR_Z)n₃-、-CH(-Sp-P₅)-、-CH₂CH(-Sp-P₅)-或者-CH(-Sp-P₅)CH(-Sp-P₅)-；n₁、n₂、n₃各自獨立地表示1、2、3或4；R_Y、R_Z各自獨立地表示H或碳原子數為1-5的烷基，且R_Y、R_Z中至少一個為碳原子數為1-5的烷基； Sp表示單鍵或間隔基；P₅表示H或可聚合基團；R_x表示

Sp³、Sp⁴、Sp⁶各自獨立地表示單鍵或間隔基； X₂表示-OH、-OR_V、-Sp⁷OH、-SH、-SR_V、-Sp⁷SH、

或環碸；R_V表示碳原子數為1-5的烷基；Sp⁷表示單鍵或間隔基。 Wherein, R ₀ represents an alkyl group having 1 to 10 carbon atoms, a fluorine-substituted alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a fluorine-substituted alkyl group having 1 carbon atoms. -10 alkoxy group, straight-chain alkenyl group with 2-10 carbon atoms, fluorine-substituted straight-chain alkenyl group with 2-10 carbon atoms, straight-chain alkenyloxy group with 3-8 carbon atoms, or Fluorine-substituted linear alkenyloxy group with 3-8 carbon atoms, and any -CH ₂ - is optionally replaced by a cycloalkylene group; any one or more unconnected -CH ₂ - is optionally replaced by -O -Substitution; the cycloalkylene group can include cyclopentylene, cyclobutylene or cyclopropylene, that is, a cycloalkylene group with a carbon number of 3-5; q represents 1, 2 or 3; K ₁ , K ₂ each independently represents an aromatic ring, heteroaromatic ring, aliphatic ring or condensed ring, wherein any -CH ₂ - on the ring is optionally replaced by O-, -S-, and the rings of K ₁ and K ₂ One or more H of are optionally substituted by L or -Sp ¹ -P ₄ ; L represents -Sp ² -X ₁ , F, alkyl group with carbon atoms of 1-10, fluorine substituted carbon atoms of 1- Alkyl group with 10 carbon atoms, alkoxy group with 1-10 carbon atoms, fluorine-substituted alkoxy group with 1-10 carbon atoms, linear alkenyl group with 2-10 carbon atoms, fluorine-substituted carbon atoms A linear alkenyl group with a number of 2-10, a linear alkenyloxy group with a carbon number of 3-8, or a fluorine-substituted linear alkenyloxy group with a carbon number of 3-8, and any -CH ₂ - can be replaced by cyclopentylene, cyclobutylene or cyclopropylene; P ₄ represents H or a polymerizable group; X ₁ represents -OH, -OR _W , -Sp ⁵ OH, -SH, -SR _W , -Sp ⁵ SH,

Or cycloterine; R _W represents an alkyl group with a carbon number of 1-5; Sp ¹ , Sp ² , Sp ⁵ each independently represents a single bond or spacer; Z ₀ represents a single bond, -O-, -S-, -CO-, -COO-, -OCO-, -OCOO-, -OCH ₂ -, -CH ₂ O-, -SCH ₂ -, -CH ₂ S-, -CF ₂ O-, -OCF ₂ -, - CF ₂ S-, -SCF ₂ -, -(CH ₂ )n ₁ -, -CF ₂ CH ₂ -, -CH ₂ CF ₂ -, -(CF ₂ )n ₂ -, -CH=CH-, -C ≡C-, -CF=CF-, -CH=CH-COO-, -OCO-CH=CH-, -(CR _Y R _Z )n ₃ -, -CH(-Sp-P ₅ )-, -CH ₂ CH(-Sp-P ₅ )- or -CH(-Sp-P ₅ )CH(-Sp-P ₅ )-; n ₁ , n ₂ , n ₃ each independently represents 1, 2, 3 or 4; R _Y and R _Z each independently represent H or an alkyl group with 1 to 5 carbon atoms, and at least one of R _Y and R _Z is an alkyl group with 1 to 5 carbon atoms; Sp represents a single bond or spacer group ;P ₅ represents H or polymerizable group; R _x represents

Sp ³ , Sp ⁴ , and Sp ⁶ each independently represent a single bond or a spacer group; X ₂ represents -OH, -OR _V , -Sp ⁷ OH, -SH, -SR _V , -Sp ⁷ SH,

Or cycloterine; R _V represents an alkyl group with a carbon number of 1-5; Sp ⁷ represents a single bond or spacer.

The compound represented by Formula I has good solubility in the liquid crystal composition. The amount added to the liquid crystal composition is generally between 0.5-5%, preferably between 1-2%, calculated as mass percentage. Formula I is shown The compound easily absorbs UV and polymerizes quickly to form a polymer with alignment function.

或環碸，X₂表示-OH、-OR_V、-Sp⁷OH、-SH、-SR_V、 -S_p ⁷SH、

或環碸；在液晶組合物經過ODF製程後，式I所示化合物自發垂直排列在面板(玻璃表面或是ITO或聚醯亞胺)表面，在加電壓條件下，經過UV光照聚合後，形成穩定的預傾角。 X ₁ and X ₂ represent anchoring groups, and X ₁ represents -OH, -OR ³ , -Sp ⁵ OH, -SH, -SR ³ , -Sp ⁵ SH,

Or ring, X ₂ represents -OH, -OR _V , -Sp ⁷ OH, -SH, -SR _V , -S _p ⁷ SH,

Or ring; after the liquid crystal composition undergoes the ODF process, the compound represented by formula I is spontaneously arranged vertically on the surface of the panel (glass surface or ITO or polyimide), and is polymerized by UV light under voltage conditions to form Stable pretilt angle.

When P ₄ and P ₅ represent a polymerizable group, it is preferably a methacrylate group, an acrylate group, a vinyl group or an oxirane group.

The "spacer group" mentioned in the present invention represents a chain group, preferably a branched or linear alkyl group with 1 to 10 carbon atoms, and any unconnected -CH ₂ - in the alkyl group can be replaced by O Instead, any _-CH2- is optionally replaced by cyclopropylene, cyclobutylene or cyclopentylene.

K ₁ and K ₂ represent aromatic ring, heteroaromatic ring, aliphatic ring or condensed ring, in which any -CH ₂ - on the ring is optionally replaced by -O-, -S-; K ₁ and K ₂ on the ring One or more H of is optionally replaced by L or -Sp ¹ -P ₄ .

The aromatic ring is preferably a benzene ring or naphthalene ring, the heteroaromatic ring is preferably a benzene ring or naphthalene ring in which at least one -CH- is replaced by -N-, and the aliphatic ring is preferably cyclohexane or cyclohexene, with at least one -CH ₂ -Cyclohexane substituted by -O- or -S-, and cyclohexene in which at least one -CH ₂ -substituted by -O- or -S-. It can also represent spiro ring and bridged ring, preferably bicyclo(1,1,1)pentane, bicyclo(2,2,2)octane, bicyclo(3,3,0)octane, spiro(3,3 ) Heptane, decahydronaphthalene, tetrahydronaphthalene, etc. The fused ring is preferably an indene ring, an indene ring, an indene ring substituted by -O- or -S-, and an indene ring substituted by -O- or -S-.

Optionally, the compound represented by Formula I is selected from the group consisting of the compounds represented by Formula I1 to Formula I31 below.

The present invention also provides a liquid crystal composition, which contains one or more compounds represented by the aforementioned formula I.

Optionally, the liquid crystal composition of the present invention may also include one or more compounds of formula II and one or more compounds of formula III,

各自獨立地表示

或

式III中，R₃、R₄各自獨立地表示碳原子數為1-10的烷基、氟取代的碳原子數為1-10的烷基、碳原子數為1-10的烷氧基、氟取代的碳原子數為1-10的烷氧基、碳原子數為2-10的直鏈烯基、氟取代的碳原子數為2-10的直鏈烯基、碳原子數為3-8的直鏈烯氧基或氟取代的碳原子數為3-8的直鏈烯氧基，且R₃、R₄中任意一個或多個不相連的-CH₂-任選被亞環戊基、亞環丁基或亞環丙基替代，Z₁、Z₂各自獨立地表示單鍵、-CH₂CH₂-或-CH₂O-；

各自獨立地表示

m表示1或2；n表示0、1或2。 In Formula II, R ₁ and R ₂ each independently represent an alkyl group having 1 to 10 carbon atoms, a fluorine-substituted alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, Fluorine-substituted alkoxy group with 1-10 carbon atoms, linear alkenyl group with 2-10 carbon atoms, fluorine-substituted linear alkenyl group with 2-10 carbon atoms, 3- 8 straight-chain alkenyloxy groups or fluorine-substituted straight-chain alkenyloxy groups with 3-8 carbon atoms,

represent each independently

or

In formula III, R ₃ and R ₄ each independently represent an alkyl group having 1 to 10 carbon atoms, a fluorine-substituted alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, Fluorine-substituted alkoxy group with 1-10 carbon atoms, linear alkenyl group with 2-10 carbon atoms, fluorine-substituted linear alkenyl group with 2-10 carbon atoms, 3- 8 linear alkenyloxy group or a fluorine-substituted linear alkenyloxy group with a carbon number of 3-8, and any one or more of R ₃ and R ₄ that are not connected -CH ₂ - is optionally replaced by cyclopentylene group, cyclobutylene or cyclopropylene group, Z ₁ and Z ₂ each independently represent a single bond, -CH ₂ CH ₂ - or -CH ₂ O-;

represent each independently

m represents 1 or 2; n represents 0, 1 or 2.

Optionally, the above-mentioned one or more compounds represented by formula II are selected from the compounds represented by formulas II1-II14; the above-mentioned one or more compounds represented by formula III are selected from the compounds represented by formulas III1-III11,

In formula III1 to formula III11, R ₃ and R ₄ each independently represent an alkyl group having 1 to 10 carbon atoms, a fluorine-substituted alkyl group having 1 to 10 carbon atoms, or an alkyl group having 1 to 10 carbon atoms. Oxygen group, fluorine-substituted alkoxy group with 1-10 carbon atoms, linear alkenyl group with 2-10 carbon atoms, fluorine-substituted linear alkenyl group with 2-10 carbon atoms, carbon number A linear alkenyloxy group of 3-8 or a fluorine-substituted linear alkenyloxy group of 3-8 carbon atoms, and any one or more of R ₃ and R ₄ that are not connected -CH ₂ - are optionally replaced by cyclopentylene, cyclobutylene or cyclopropylene substitution.

In the above-mentioned _liquid crystal composition, in the compound represented by Formula _I , the anchoring functional groups represented _{by X1} and After the ODF process of the panel, due to the intermolecular force between the anchoring functional groups and the panel surface (glass surface, ITO electrode surface), they will spontaneously be vertically arranged on the surface of the panel glass or ITO transparent electrode substrate, prompting the approach to Formula I The liquid crystal molecules of the compound shown are arranged vertically. Under UV light irradiation, the compound shown in formula I will polymerize on the substrate to form a layer of polymer with a rough surface, which plays the role of insulating PI and vertically aligning liquid crystal molecules. Usually, PI The thickness is between 50nm and 120nm. In order to make the compound represented by formula I form a film with the same thickness as PI after polymerization, the added amount of the compound represented by formula I is preferably more than 1% in terms of mass percentage. In this case, the compound represented by formula I is added in a larger amount, so there are higher requirements for its storage stability at low temperatures.

。五價磷酸結構不僅可以起到間隔基的作用，還可以一定程度上起到錨定協同作用，可以增加式I所示化合物的錨定力。 The compound represented by Formula I of the present invention not only contains an anchoring group, but also contains a pentavalent phosphate structure.

. The pentavalent phosphoric acid structure can not only function as a spacer, but also play an anchoring synergy to a certain extent, which can increase the anchoring force of the compound represented by Formula I.

The compound represented by formula I provided by the present invention has the advantages of good miscibility with other monomers and good ultraviolet resistance. As a reactive mesogen (RM), it has the advantages of good mutual solubility, high polymerization activity (less monomer residue), and strong binding ability. It can not only be used as a self-alignment agent for liquid crystal compositions alone, but also as a vertical alignment material. A self-aligning agent copolymerized with RM for PSA (polymer-supported alignment) and PS (polymer-stabilized) mode liquid crystal mixtures, which can avoid the PI process, simplify the process of liquid crystal display elements or liquid crystal displays, and improve production. efficiency.

In addition, a liquid crystal composition containing a compound represented by Formula I or an optically anisotropic body of a liquid crystal composition also falls within the scope of the present invention.

Due to different substituents, the solubility properties of the compound of formula I in liquid crystal will be slightly different, but it can be added in a mass percentage of 0.5%-5% in the liquid crystal composition. Since the polymer formed by the compound of formula I must have the insulating effect of PI, a certain thickness is necessary, so the compound of formula I must have sufficient solubility.

The addition amount (mass percentage) of the compound of formula I in the liquid crystal composition can be 0.5%-5%, preferably 1-3%.

The addition amount (mass percentage) of the compound represented by formula II in the liquid crystal composition can be 15-60%, preferably 20-40%.

The addition amount (mass percentage) of the compound represented by Formula III in the liquid crystal composition can be 20-60%, preferably 30-50%.

Optionally, the liquid crystal composition of the present invention may also contain one or more compounds represented by Formula IV

Among them, R ₅ and R ₆ each independently represent an alkyl group having 1 to 10 carbon atoms, a fluorine-substituted alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a fluorine-substituted alkyl group. Alkoxy group with 1-10 carbon atoms, linear alkenyl group with 2-10 carbon atoms, fluorine-substituted linear alkenyl group with 2-10 carbon atoms, 3-8 carbon atoms A linear alkenyloxy group or a fluorine-substituted linear alkenyloxy group with 3-8 carbon atoms, and any one or more of R ₅ and R ₆ -CH ₂ - are optionally substituted by cyclopentylene or cyclobutylene. group or cyclopropylene group; W represents -O-, -S- or -CH ₂ O-.

Optionally, one or more of the above-mentioned compounds represented by formula IV are selected from compounds represented by formulas IV1-IV6:

Wherein, R ₆₁ represents an alkyl group having 2 to 6 carbon atoms.

The addition amount (mass percentage) of the compound represented by Formula IV in the liquid crystal composition can be 1-15%, preferably 2-10%.

Optionally, the liquid crystal composition of the present invention may also contain one or more compounds represented by formula V

Among them, R ₇ and R ₈ each independently represent an alkyl group having 1 to 10 carbon atoms, a fluorine-substituted alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a fluorine-substituted alkyl group. Alkoxy group with 1-10 carbon atoms, linear alkenyl group with 2-10 carbon atoms, fluorine-substituted linear alkenyl group with 2-10 carbon atoms, 3-8 carbon atoms A linear alkenyloxy group or a fluorine-substituted linear alkenyloxy group having 3 to 8 carbon atoms.

各自獨立地表示1，4-亞苯基、1，4-亞環己基或1，4-亞環己烯基。

Each independently represents a 1,4-phenylene group, a 1,4-cyclohexylene group or a 1,4-cyclohexenylene group.

Optionally, one or more of the above-mentioned compounds represented by formula V are selected from the group consisting of compounds represented by formulas V1-V4:

Among them, R ₇₁ and R ₈₁ each independently represent an alkyl group with 2-6 carbon atoms or an alkenyl group with 2-6 carbon atoms; R ₈₂ represents an alkoxy group with 1-5 carbon atoms; wherein, Examples of the alkenyl group having 2 to 6 carbon atoms include vinyl, 2-propenyl or 3-pentenyl.

The addition amount (mass percentage) of the compound represented by formula V in the liquid crystal composition can be 1-40%, preferably 5-30%.

Optionally, the liquid crystal composition of the present invention may also contain one or more polymerizable compounds represented by Formula VI.

各自獨立的表示亞苯基、氟代的亞苯基或茚滿基；P₁、P₂、P₃各自獨立的表示甲基丙烯酸酯基或丙烯酸酯基；可選的，上述一種或多種式VI所示的化合物選自式VI1-VI3所示化合物中組成的群組：

Each independently represents a phenylene group, a fluorinated phenylene group or an indanyl group; P ₁ , P ₂ and P ₃ each independently represents a methacrylate group or an acrylate group; optionally, one or more of the above formulas The compound represented by VI is selected from the group consisting of compounds represented by formulas VI1-VI3:

Compared with the compound represented by formula I, the compound represented by formula VI is slightly less sensitive to UV and has a slightly slower polymerization speed. In the actually formed polymer, the compound represented by formula VI is relatively on the surface layer. When the compound represented by formula VI is copolymerized with the compound represented by formula I, the display effect can be improved. The polymer layer provides a sustained and stable pretilt. The pretilt of the liquid crystal molecules is very conducive to increasing the reaction speed of the liquid crystal under an electric field. In the case where the compound represented by formula VI is added to copolymerize with the compound represented by formula I, the added amount of the compound represented by formula VI can be 0.1-1% in terms of mass percentage, preferably 0.2-0.5%.

The liquid crystal composition of the present invention will show slightly different properties depending on the different proportions of each component, such as dielectric anisotropy Δε, optical anisotropy Δn, and the transition temperature point at which the nematic phase of the liquid crystal transforms into a liquid. The stability of CP and low temperature will be different, but the same feature is that its rotational viscosity γ ₁ is low. Applied to liquid crystal display components, rapid response can be achieved. The liquid crystal composition has high stability to heat and light. The liquid crystal display element or liquid crystal display containing the liquid crystal composition has a wide nematic phase temperature range, suitable or high birefringence anisotropy Δn, very high resistivity, good ultraviolet resistance, high Voltage holding rate and low vapor pressure. PSVA liquid crystal compositions suitable for display or TV applications have no or significantly reduced image sticking, especially after long-term operation.

Dopants with various functions can also be added to the liquid crystal compound provided by the present invention. The dopant content is preferably between 0.01-1% in terms of mass percentage. These dopants are mainly antioxidants, ultraviolet absorbers, hand Sexual agent.

Preferable antioxidants and ultraviolet absorbers include:

S represents an integer from 1 to 10.

The present invention also provides a liquid crystal display element or liquid crystal display comprising any one of the above liquid crystal compositions; the display element or display is an active matrix display element or display or a passive matrix display element or display.

Optionally, the liquid crystal display element or liquid crystal display is preferably an active matrix addressing liquid crystal display element or liquid crystal display.

Optionally, the active matrix display element or display is a PSVA-TFT liquid crystal display element or display without a PI alignment layer.

The present invention will be further described below with reference to specific examples, but the present invention is not limited to the following examples. The methods described are conventional methods unless otherwise stated. The raw materials mentioned can be obtained from public commercial sources unless otherwise specified.

The reaction process is generally monitored by TLC. The post-treatment at the end of the reaction is generally water washing, extraction, drying after combining the organic phases, evaporating the solvent under reduced pressure, recrystallization, and column chromatography. It is common knowledge in this field. Anyone can implement the invention according to the following description.

The percentages in this manual are mass percentages, and the temperature is degrees Celsius (℃). The specific meanings and test conditions of other symbols are as follows: Cp represents the liquid crystal clearing point (℃), tested by DSC quantitative method; △n represents optical anisotropy, △n =n _e -n _o , n _o is the refractive index of ordinary light, n _e is the refractive index of extraordinary light, the test conditions are 25±2℃, 589nm, Abbe refractometer test; △ε represents dielectric anisotropy , △ε=ε _∥ -ε _⊥ , where ε _∥ is the dielectric constant parallel to the molecular axis, ε _⊥ is the dielectric constant perpendicular to the molecular axis, the test conditions are 25±0.5℃, 20 micron parallel box, INSTEC : ALCT-IR1 test; γ1 represents rotational viscosity (mPa.s), test conditions are 25±0.5℃, 20 micron parallel box, INSTEC: ALCT-IR1 test; The preparation method of the liquid crystal composition is as follows: Each liquid crystal monomer is prepared according to Weigh a certain proportion and put it into a stainless steel beaker. Place the stainless steel beaker containing each liquid crystal monomer on a magnetic stirring instrument to heat and melt. After most of the liquid crystal monomer in the stainless steel beaker is melted, add it to the stainless steel beaker. Using a magnetic rotor, stir the mixture evenly and cool to room temperature to obtain a liquid crystal composition.

The liquid crystal monomer structure in the embodiment of the present invention is represented by a code. The code representation method of the liquid crystal ring structure, end group, and connecting group is shown in the following tables (1) and (2).

Table (2): Corresponding codes of terminal groups and linking groups

Example:

The compound represented by formula I can be prepared by the following schematic synthesis route:

Example 1:

Step 1

Add 29.2g (0.10mol) of amylcyclohexyl-o-fluorophenylboronic acid, 17.3g (0.10mol) of p-bromophenol, 16.6g (0.12mol) of potassium carbonate, 0.5g of Pd(dppf) ₂ Cl ₂ and toluene into the reaction bottle. 300mL and water 100mL. Heat to reflux under nitrogen protection. After 2 hours of reaction, the raw materials disappear by spot plate detection. Add water and toluene, stir, extract and separate the liquids. Extract the water layer twice with toluene and combine the toluene layers. Wash with water and pass through silica gel column chromatography. Spin the solvent dry and recrystallize with toluene and ethanol three times to obtain 25.5g of white solid. GC :99.1%.

Step 2

Add 25.5g (0.075mol) compound 1, 16.9g (0.09mol) 1.2-dibromoethane, 16.6g (0.12mol) potassium carbonate and 200mL DMF into the reaction bottle, heat and stir, and react at 70°C until compound 1 disappears as detected by the spot plate. . Add water and toluene, stir, extract and separate the liquids. Extract the aqueous layer twice with toluene and combine the toluene layers. Wash with water and pass through silica gel column chromatography. Spin the solvent dry and recrystallize with toluene and ethanol three times to obtain 21.5g of white solid. GC :98.8%.

Step 3

Add 21.5g (0.03mol) compound 2 and 100mL triethyl phosphite into the reaction bottle and react at 135°C until compound 2 disappears as detected by spot plate. After cooling, the excess triethyl phosphite was spin-dried, and recrystallized three times with toluene and ethanol to obtain 12.7 g of white solid, GC: 97.8%.

Step 4

Add 12.7g (0.025mol) compound 3, 2g (0.05mol) sodium hydroxide, 50mL tetrahydrofuran and 50mL water to the reaction bottle. Stir at room temperature for 2 hours, and detect the disappearance of raw materials by spotting. Adjust the pH to 2 with 1N hydrochloric acid, and extract the aqueous phase twice with ethyl acetate. The organic phases were combined, the solvent was spun dry, and the mixture was recrystallized three times with toluene ethanol to obtain 5 g of white solid, GC: 99.8%.

Example 2:

Step 1

Add 37.8g (0.10mol) of pentycyclohexylphenyl o-ethylphenylboronic acid, 27.9g (0.10mol) of 2-benzyloxy-4-bromophenol, 16.6g (0.12mol) of potassium carbonate, and Pd into the reaction bottle. (dppf) ₂ Cl ₂ 0.5g, toluene 500mL and water 150mL. Heat to reflux under nitrogen protection. After 2 hours of reaction, the raw materials disappear by spot plate detection. Add water and toluene, stir, extract and separate the liquids. Extract the aqueous layer twice with toluene and combine the toluene layers. Wash with water and pass through silica gel column chromatography. Spin the solvent dry and recrystallize with toluene and ethanol three times to obtain 45.5g of white solid. GC :99.2%.

Step 2

Referring to step 2 of Example 1, compound 1 was etherified with 1,2-dibromoethane to obtain compound 2, 35.9 g of off-white solid, GC: 97.2%.

Step 3

Referring to step 3 of Example 1, compound 2 was reacted with triethyl phosphite to obtain compound 3, 25.3 g of off-white solid, GC: 97.2%.

Step 4

Add 25.3g (0.036mol) compound 3, 2.53g 5% Pd/C catalyst, 250mL ethanol and 250mL tetrahydrofuran into the reaction bottle. Under 50Psi hydrogen pressure and 60°C for 4 hours, compound 3 disappeared as detected by the spot plate. The Pd/C catalyst was removed by suction filtration, and the filtrate was spin-dried and recrystallized three times with toluene and ethanol to obtain 18.7g of white solid, GC: 97.9%.

Step 5

Add 18.7g (0.031mol) compound 3, 3.0g (0.037mmol) 2-chloroethanol, 5.1g (0.037mmol) potassium carbonate and 300mL DMF to the reaction bottle, heat and stir, and react at 120°C until compound 3 disappears as detected by the spot plate. Add water and toluene, stir, extract and separate the liquids. Extract the aqueous layer twice with toluene and combine the toluene layers. Wash with water and pass through silica gel column chromatography. Spin the solvent dry and recrystallize with toluene and ethanol three times to obtain 11.5g of white solid. GC :98.3%.

Step 6

Add 11.5g (0.018mol) compound 4, 1.8g (0.021mol) methacrylic acid and 150mL methylene chloride into the reaction bottle and stir to completely dissolve. Add 4.3g (0.021mol) DCC at room temperature, and then stir at room temperature for 4 hours. , the spot plate detects the disappearance of compound 4; add water, stir and separate the liquids, extract the aqueous layer twice with dichloromethane, combine the dichloromethane layers, wash with water and dry over anhydrous sodium sulfate, spin the solvent dry, dissolve with toluene and pass through a silica gel column Chromatography and recrystallization with toluene and ethanol three times gave 7.6 g of white solid, HPLC: 99.7%.

Example 3:

Step 1

Add 57.2g (0.20mol) of amylphenyl-o-fluorophenylboronic acid, 34.6g (0.20mol) of 4-bromophenol, 33.1g (0.24mol) of potassium carbonate, 1.0g of Pd(dppf) ₂ Cl ₂ into the reaction bottle. 500mL of toluene and 150mL of water. Heat to reflux under nitrogen protection. After 2 hours of reaction, the raw materials disappear by spot plate detection. Add water and toluene, stir, extract and separate the liquids. Extract the aqueous layer twice with toluene and combine the toluene layers. Wash with water and pass through silica gel column chromatography. Spin the solvent dry and recrystallize with toluene and ethanol three times to obtain 45.5g of white solid. GC :99.2%.

Step 2

According to the method described in patent CN105001879A, dibromo compound 2 was prepared from compound 1 to obtain 52.1g of yellow viscous oil, GC: 97.7%.

Step 3

Referring to step 3 of Example 1, 43.0g (0.2mol) of compound 2' was reacted with triethyl phosphite, and then distilled under reduced pressure to obtain compound 3, 39.3g of yellow viscous oil, GC: 98.5%.

Step 4

Add 35.3g (0.14mol) compound 3 and 350mL tetrahydrofuran to the reaction bottle. The reaction system was cooled to 0°C, and 21.3g (0.56mol) LiAlH ₄ was added in batches. Afterwards, the mixture was stirred at room temperature for 2 hours, and the disappearance of compound 3 was detected by spot plate detection. Add hydrochloric acid to adjust the pH to acidity, and extract the aqueous phase twice with ethyl acetate. Compound 4 was obtained by distillation under reduced pressure, 20.9 g of yellow viscous oil, GC: 97.9%.

Step 5

Add 28.9g (0.12mol) compound 4 and 300mL tetrahydrofuran to the reaction bottle, and cool to -78°C. 105.6 mL (0.26 mol) n-butyllithium (2.5N) was added in batches, and then stirred at -78°C for 1 hour. Then 40.3g (0.26mol) 2-bromomethyl sulfide was added dropwise. After the dropwise addition was completed, the mixture was stirred at -78°C for 30 minutes. Then, the temperature was slowly raised to room temperature, and the disappearance of compound 4 was detected using a spot plate. Pour the reaction solution into ice water with stirring, extract with toluene and pass through silica gel column chromatography. Spin off the solvent to obtain 36.6g of light yellow liquid, GC: 95.8%.

Step 6

Add 36.6g (0.115mol) compound 5 and 360mL tetrahydrofuran to the reaction bottle, slowly add 60.4g (0.35mol) m-chloroperoxybenzoic acid in batches, stir at room temperature, and detect the disappearance of the raw materials using a spot plate Stop the reaction, add water and ethyl acetate, stir, extract and separate the layers. The aqueous layer is extracted twice with ethyl acetate and the organic layers are combined. After washing with water, the solvent is spun dry and distilled under reduced pressure to obtain 24.6g of a light yellow liquid, GC: 98.8%.

Step 7

Referring to step 4 of Example 2, compound 6 was hydrodebenzylated with palladium on carbon to obtain product compound 7, 14.7 g of yellow liquid, GC: 96.2%.

Step 8

Add 23.6g (0.048mol) compound 2, 14.7g (0.048mol) compound 7, 15.2g (0.058mol) triphenylphosphine and 500mL tetrahydrofuran into the reaction bottle. Dissolve 8.4g (0.048mol) diethyl azodicarboxylate in 100mL tetrahydrofuran, and slowly add it dropwise to the reaction system at 0°C. Afterwards, the reaction system was stirred at 0°C for 1 hour and then at room temperature for 4 hours. The disappearance of raw materials was detected by spot plate. Add water and toluene, stir, extract and separate the liquids. Extract the aqueous layer twice with toluene and combine the toluene layers. Wash with water and pass through silica gel column chromatography. Spin the solvent dry and recrystallize with toluene and ethanol three times to obtain 21.6g of white solid. LC :95.8%.

Step 9

Add 21.6g (0.028mol) compound 8, 6.9g (0.07mol) potassium acetate, 17.8g (0.07mol) pinacol diborate, 250mL DMF and 0.5g tetrakis triphenylphosphine palladium into the reaction bottle. The temperature was raised to 100 degrees Celsius under nitrogen protection, and the reaction was carried out for 2 hours. The spot plate detected the disappearance of compound 8. After cooling, add water and toluene, stir, extract and separate the layers. Extract the aqueous layer twice with toluene and combine the toluene layers. Wash with water and pass through silica gel column chromatography. Spin the solvent dry and recrystallize with toluene and ethanol three times to obtain a white solid 18.5. g, LC: 95.2%.

Step 10

Add 18.5g (0.021mol) compound 9 and 200mL tetrahydrofuran to the reaction bottle, and then slowly add 12.5g (0.11mol) 30% hydrogen peroxide dropwise. The reaction was refluxed for 2 hours, and compound 9 disappeared by spot plate detection. After cooling, add water and toluene, stir, extract and separate the liquids. Extract the aqueous layer twice with toluene and combine the toluene layers. Wash with water and pass through silica gel column chromatography. Spin the solvent dry and recrystallize with toluene and ethanol three times to obtain a white solid 10.3. g, LC: 95.2%.

Step 11

Add 10.3g (0.016mol) compound 10, 3.3g (0.038mol) methacrylic acid and 100mL methylene chloride into the reaction bottle and stir to completely dissolve. Add 7.8g (0.038mol) DCC at room temperature, and then stir at room temperature for 4 hours. , the spot plate detects the disappearance of compound 10; add water, stir and separate the liquids, extract the aqueous layer twice with dichloromethane, combine the dichloromethane layers, wash with water and dry over anhydrous sodium sulfate, spin the solvent dry, dissolve with toluene and then layer the silica tube column Analyze and recrystallize three times with toluene and ethanol to obtain 7.1g of white solid, HPLC: 99.7%.

Example 4: Each component in the liquid crystal composition and its mass percentage are as shown in the table below.

Example 5: Each component in the liquid crystal composition and its mass percentage are as shown in the table below.

Example 6: Each component in the liquid crystal composition and its mass percentage are as shown in the table below.

Example 7: Each component in the liquid crystal composition and its mass percentage are as shown in the table below.

Comparative example 1

Replace I26 in Example 7 with the existing reactive mesogen (A) with a dihydroxy structure

Comparing Example 7 with Comparative Example 1, it can be seen that the binding force of a greater content of the compound represented by formula (A) can be achieved by using a smaller content of the compound represented by formula I26.

In summary, the compound represented by Formula I can achieve the insulating effect of PI after polymerization, and can achieve vertical alignment. Polymerization occurs under the condition of applying voltage. After the voltage is removed, the polymer layer can provide a continuous and stable pretilt, so that the liquid crystal molecules have a stable pretilt. The pretilt of the liquid crystal molecules is very beneficial. Improve the reaction speed of liquid crystal molecules under electric field. In addition, the compound represented by Formula I has strong binding force with the component substrate after polymerization, and it is possible to achieve the same bonding force effect as the existing reactive mesogen by using a smaller content of the compound represented by Formula I.

Claims (6)

A liquid crystal composition, including one or more compounds represented by formula I1 to formula I31, one or more compounds represented by formula IV3 and a compound represented by formula VI1,

Wherein, R ₆₁ represents an alkyl group with 2-6 carbon atoms; the mass percentage of the one or more compounds represented by Formula I1 to Formula I31 is 1-3%. The liquid crystal composition according to claim 1, further comprising one or more compounds of formula II and one or more compounds of formula III,

In Formula II, R ₁ and R ₂ each independently represent an alkyl group having 1 to 10 carbon atoms, a fluorine-substituted alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, Fluorine-substituted alkoxy group with 1-10 carbon atoms, linear alkenyl group with 2-10 carbon atoms, fluorine-substituted linear alkenyl group with 2-10 carbon atoms, 3- 8 straight-chain alkenyloxy groups or fluorine-substituted straight-chain alkenyloxy groups with 3-8 carbon atoms;

represent each independently

or

In formula III, R ₃ and R ₄ each independently represent an alkyl group having 1 to 10 carbon atoms, a fluorine-substituted alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, Fluorine-substituted alkoxy group with 1-10 carbon atoms, linear alkenyl group with 2-10 carbon atoms, fluorine-substituted linear alkenyl group with 2-10 carbon atoms, 3- 8 alkenyloxy group or fluorine-substituted linear alkenyloxy group with 3-8 carbon atoms, and any one or more of R ₃ and R ₄ that are not connected -CH ₂ - is optionally replaced by a cyclopentylene group , cyclobutylene or cyclopropylene instead; Z ₁ and Z ₂ each independently represent a single bond, -CH ₂ CH ₂ - or -CH ₂ O-;

represent each independently

or

; and m represents 1 or 2; n represents 0, 1 or 2. The liquid crystal composition according to claim 2, wherein the one or more compounds represented by formula II are selected from the group of compounds represented by formula II1-II14; the one or more compounds represented by formula III are selected from the group consisting of compounds represented by formula III1 -The group consisting of the compounds shown in III11,

In formula III1 to formula III11, R ₃ and R ₄ each independently represent an alkyl group having 1 to 10 carbon atoms, a fluorine-substituted alkyl group having 1 to 10 carbon atoms, or an alkyl group having 1 to 10 carbon atoms. Oxygen group, fluorine-substituted alkoxy group with 1-10 carbon atoms, linear alkenyl group with 2-10 carbon atoms, fluorine-substituted linear alkenyl group with 2-10 carbon atoms, carbon number A linear alkenyloxy group of 3-8 or a fluorine-substituted linear alkenyloxy group of 3-8 carbon atoms, and any one or more of R ₃ and R ₄ that are not connected -CH ₂ - are optionally substituted by Cyclopentylene, cyclobutylene or cyclopropylene substitution. The liquid crystal composition according to any one of claims 1 to 3, wherein the liquid crystal composition is a negative dielectric anisotropic liquid crystal composition, and the liquid crystal composition further contains one or more compounds represented by formula V,

Among them, R ₇ and R ₈ each independently represent an alkyl group having 1 to 10 carbon atoms, a fluorine-substituted alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a fluorine-substituted alkyl group. Alkoxy group with 1-10 carbon atoms, linear alkenyl group with 2-10 carbon atoms, fluorine-substituted linear alkenyl group with 2-10 carbon atoms, 3-8 carbon atoms Straight-chain alkenyloxy group or fluorine-substituted straight-chain alkenyloxy group with 3-8 carbon atoms; and

Each independently represents a 1,4-phenylene group, a 1,4-cyclohexylene group or a 1,4-cyclohexenylene group. A liquid crystal display element, which contains the liquid crystal composition according to any one of claims 1 to 4; the display element is an active matrix display element or a passive matrix display element. The liquid crystal display element of claim 5, wherein the active matrix display element is a PSVA-TFT liquid crystal display element without a polyimide (polyimide, PI) alignment layer.