Chiral agent compound, cholesteric liquid crystal composition containing chiral agent compound and application of chiral agent compound and cholesteric liquid crystal composition

Abstract

The invention discloses a photosensitive chiral agent compound S, a cholesteric liquid crystal composition containing the photosensitive chiral agent compound S, and application of the cholesteric liquid crystal composition in liquid crystal display elements and liquid crystal displays. The photosensitive chiral agent compound S has the performance of high HTP value, good solubility and short conversion time, and the cholesteric liquid crystal composition containing the photosensitive chiral agent compound S has high reflectivity retention rate, ensures uniform RGB color and does not need tedious pixel design; the viscosity is low, so that the adhesive can adapt to the existing large-scale panel preparation process; and the UV color changing speed is high, the UV manufacturing time is shortened, the production cost is reduced, and the liquid crystal display film can be widely applied to optical devices such as liquid crystal electronic books, outdoor and vehicle-mounted displays and the like. # imgabs0 #

Description

Technical Field

[0001] The present invention provides a novel chiral agent compound and a photochromic cholesteric liquid crystal composition as a display element material and a display element using the same, which are mainly applicable to the technical fields of liquid crystal electronic books, electronic signs, bistable liquid crystal displays and the like. Background Art

[0002] In recent years, reflective displays (such as electronic paper, e-books, smart cards and other products) are booming. In the application of electronic paper, cholesteric liquid crystals have better performance in brightness and contrast compared with other display media. At the same time, cholesteric liquid crystals have the advantages of being passively driven and easy to produce.

[0003] The planar state and focal conic state of cholesteric liquid crystal are stable and can remain stable for a long time, thus having bistability. Cholesteric liquid crystal has Bragg reflection in the planar state. The reflection wavelength (λ) is determined by the average refractive index (n) and chiral pitch (P) of the liquid crystal composition, λ = n 平均 ×P. When the refractive index of the liquid crystal composition is fixed, the chiral pitch P can be adjusted by increasing or decreasing the amount of chiral compounds, thereby obtaining different colors of reflected wavelengths. Under the same pitch, the wavelength width (Δλ) of the reflected light is proportional to the refractive index anisotropy (Δn=ne-no) of the liquid crystal. In order to achieve high brightness of reflection, a liquid crystal composition with a large Δn is required.

[0004] Cholesteric liquid crystal displays use cholesteric liquid crystal compositions, and traditional cholesteric liquid crystal compositions are composed of a nematic liquid crystal and a chiral additive. The production of light-written cholesteric liquid crystal displays requires the use of a photoreactive chiral additive with a high helical twisting force, so that the conformation of the molecules in the nematic liquid crystal can be changed by light, thereby generating a change in the helical twisting force (HTP), changing the pitch (P) of the cholesteric liquid crystal, and achieving different reflected light colors. However, traditional cholesteric displays still have problems such as insufficient reflectivity and colorization. Although prior art documents such as CN102464985A disclose a new cholesteric liquid crystal composition, the reflectivity retention rate of the cholesteric liquid crystal composition is poor and the UV color change is slow.

[0005] Cholesteric liquid crystal e-books have the advantages of high contrast and zero power consumption of displayed content, and can replace paper in daily life. It is mainly used in e-books, electronic labels, display panels, etc. At present, cholesteric liquid crystal compositions are obtained by adding optically active chiral agents to nematic liquid crystals to obtain cholesteric liquid crystal compositions. As e-books, cholesteric liquid crystals are generally colored by stacking three boxes of red, green and blue. In order to achieve colorization, the three-layer stacking scheme liquid crystal box is thick and bulky, and the display of the lower layer causes light loss due to light scattering and refraction between layers, resulting in dim color display of the three boxes, low reflectivity, and pixel alignment problems in the stacking of liquid crystal boxes. Prior art documents such as CN118308120A disclose a technical solution for using a photosensitive chiral agent to realize the colorization of a single-layer liquid crystal box, that is, by irradiating a cholesteric liquid crystal containing a photosensitive chiral agent with different UV light energies to achieve colorization. However, the above solutions also have problems and cannot be applied on a large scale. Although the higher refractive index (usually above 0.2) can ensure a higher initial reflectivity, the reflectivity usually drops significantly after UV discoloration (especially red), which greatly affects the color uniformity of the final display panel and requires additional design of the sub-pixel size. In addition, it is usually difficult for light-controlled chiral agents to take into account both a larger HTP value and a faster UV discoloration speed. A low HTP value means an increase in the amount of chiral agent added, which will increase the viscosity of the cholesteric liquid crystal and make it impossible to adapt to the ODF process. The slow UV discoloration speed means a longer process. All of these will lead to a significant increase in the cost of the panel preparation process.

[0006] Therefore, the technical problem to be solved urgently is to develop a chiral agent with high HTP value, good solubility, fast conversion time, and a composition with high reflectivity retention rate, low viscosity and fast UV color change speed. Summary of the invention

[0007] The present invention provides a technical solution that can solve the above technical problems.

[0008] Specifically, the present invention comprises a chiral agent compound selected from the following formula S,

[0009]

[0010] in,

[0011] R1 and R2 each independently represent a fluorinated alkyl group having 1 to 5 carbon atoms, a fluorinated alkoxy group having 1 to 5 carbon atoms, a fluorinated alkenyl group having 2 to 5 carbon atoms, or a fluorinated alkenyloxy group having 2 to 5 carbon atoms;

[0012] Each independently expresses Any hydrogen in the group may be replaced by halogen, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an alkenyloxy group having 2 to 10 carbon atoms;

[0013] m and n each independently represent 1 or 2.

[0014] Furthermore, the present invention provides a cholesteric liquid crystal composition. Preferably, the cholesteric liquid crystal composition comprises one or more chiral agent compounds selected from formula S.

[0015] Furthermore, the cholesteric liquid crystal composition of the present invention preferably further comprises one or more chiral agent compounds represented by formulas SA1 to SA5.

[0016]

[0017] in,

[0018] R3 and R4 each independently represent an alkyl group having 1-6 carbon atoms, an alkyl group having 1-6 carbon atoms substituted with fluorine, an alkoxy group having 1-6 carbon atoms, an alkoxy group having 1-6 carbon atoms substituted with fluorine, an alkenyl group having 2-6 carbon atoms, an alkenyl group having 2-6 carbon atoms substituted with fluorine, an alkenyloxy group having 3-8 carbon atoms or an alkenyloxy group having 3-8 carbon atoms substituted with fluorine.

[0019] The cholesteric liquid crystal composition of the present invention, preferably, comprises a chiral compound represented by formula S1-1 and at least one chiral compound represented by formulas SA1 to SA5.

[0020] In the cholesteric liquid crystal composition of the present invention, preferably, the amount of the chiral agent compound added in the cholesteric liquid crystal composition is 100% by weight of the total mass of the liquid crystal composition.

[0021] In the cholesteric liquid crystal composition of the present invention, preferably, the mass percentage of the chiral agent compound S1-1 is 0.5%-10%, and the mass percentage of the chiral agent compounds SA1 to SA5 is 0.1%-5%.

[0022] In the cholesteric liquid crystal composition of the present invention, preferably, the mass percentage of the chiral agent compound S1-1 is 2%-6%, and the mass percentage of the chiral agent compounds SA1 to SA5 is 0.1%-3%.

[0023] The present invention also provides a cholesteric liquid crystal display element, which comprises the cholesteric liquid crystal composition of the present invention, and the cholesteric liquid crystal display element is an active matrix addressing display element or a passive matrix addressing display element.

[0024] The present invention also provides a cholesteric liquid crystal display comprising the cholesteric liquid crystal composition of the present invention, wherein the cholesteric liquid crystal display is an active matrix addressing display or a passive matrix addressing display.

[0025] Beneficial Effects

[0026] The chiral agent compound provided by the present invention has the performance of taking into account high HTP value, good solubility, and fast conversion time, because the main structure of the chiral agent compound S of the present invention is cinnamate and isosorbide structure, the electron cloud density of the structure is high, the end group uses fluorine substitution group, and the introduction of fluorine atom will improve the electron cloud density, thereby enhancing the antioxidant ability and stability of the molecule, and improving solubility; in addition, in the fluoroalkoxy introduced by the end group, the lone pair of electrons of the oxygen atom can supply electrons to the benzene ring through the p-π conjugation effect, although the fluorine atom tends to withdraw electrons due to its high electronegativity, when the fluoroalkoxy is directly connected to the benzene ring, the conjugation effect of the oxygen atom is often more significant, which leads to the chiral agent compound of the structure having a higher HTP value and a shorter conversion time, and is suitable for any nematic liquid crystal component. Further, the cholesteric liquid crystal composition provided by the present invention has a higher reflectivity retention rate, and takes into account lower viscosity and faster UV color change speed. Furthermore, the liquid crystal display element or liquid crystal display comprising the cholesteric liquid crystal composition of the present invention has a higher reflectivity retention rate, a smaller decrease in reflectivity during photochromic process, and has both a faster response speed and a faster UV color change speed. DETAILED DESCRIPTION

[0027] In order to explain the present invention more clearly, the present invention is further described below in conjunction with preferred embodiments. It should be understood by those skilled in the art that the following specific description is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

[0028] The present invention provides a chiral agent compound selected from the following formula S,

[0029]

[0030] in,

[0031] R1 and R2 each independently represent a fluorinated alkyl group having 1 to 5 carbon atoms, a fluorinated alkoxy group having 1 to 5 carbon atoms, a fluorinated alkenyl group having 2 to 5 carbon atoms, or a fluorinated alkenyloxy group having 2 to 5 carbon atoms;

[0032] Each independently expresses Any hydrogen in the group may be replaced by halogen, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an alkenyloxy group having 2 to 10 carbon atoms;

[0033] m and n each independently represent 1 or 2.

[0034] The chiral agent compound of the present invention is preferably selected from the group consisting of compounds represented by the following formulas S1 to S18:

[0035]

[0036]

[0037]

[0038]

[0039] in,

[0040] R1 and R2 each independently represent a fluorinated alkyl group having 1 to 5 carbon atoms, a fluorinated alkoxy group having 1 to 5 carbon atoms, a fluorinated alkenyl group having 2 to 5 carbon atoms, or a fluorinated alkenyloxy group having 2 to 5 carbon atoms.

[0041] The chiral agent compound of the present invention, preferably, the chiral agents S1 to S18 are selected from the group consisting of compounds represented by the following formulas S1-1 to S18-2,

[0042]

[0043]

[0044]

[0045] Furthermore, the present invention provides a cholesteric liquid crystal composition. Preferably, the cholesteric liquid crystal composition comprises one or more chiral agent compounds selected from formula S.

[0046] The cholesteric liquid crystal composition of the present invention preferably comprises at least a chiral agent compound represented by formula S1-1.

[0047] The cholesteric liquid crystal composition of the present invention, preferably, further comprises one or more chiral agent compounds represented by formulas SA1 to SA5,

[0048]

[0049] in,

[0050] R3 and R4 each independently represent an alkyl group having 1-6 carbon atoms, an alkyl group having 1-6 carbon atoms substituted with fluorine, an alkoxy group having 1-6 carbon atoms, an alkoxy group having 1-6 carbon atoms substituted with fluorine, an alkenyl group having 2-6 carbon atoms, an alkenyl group having 2-6 carbon atoms substituted with fluorine, an alkenyloxy group having 3-8 carbon atoms or an alkenyloxy group having 3-8 carbon atoms substituted with fluorine.

[0051] The cholesteric liquid crystal composition of the present invention, preferably, comprises a chiral compound represented by formula S1-1 and at least one chiral compound represented by formulas SA1 to SA5.

[0052] The cholesteric liquid crystal composition of the present invention preferably has a mass percentage of chiral compound S1-1 of 0.5%-10% and a mass percentage of chiral compounds SA1 to SA5 of 0.1%-5%, based on the total mass of the chiral compound and the nematic liquid crystal component as 100%.

[0053] In the cholesteric liquid crystal composition of the present invention, preferably, the mass percentage of the chiral agent compound S1-1 is 2%-6%, and the mass percentage of the chiral agents SA1 to SA5 is 0.1%-3%.

[0054] The cholesteric liquid crystal composition of the present invention preferably further comprises a chiral agent compound represented by formula SA6,

[0055]

[0056] The cholesteric liquid crystal composition of the present invention preferably comprises a chiral agent compound represented by formula S1-1, at least one chiral agent compound selected from the group consisting of chiral agent compounds represented by formulas SA1 to SA5, and a chiral agent compound represented by formula SA6.

[0057] In the cholesteric liquid crystal composition of the present invention, preferably, the mass percentage of the chiral agent compound S1-1 is 2%-6%, the mass percentage of the chiral agent compounds SA1 to SA5 is 0.1%-3%, and the mass percentage of the chiral agent compound SA6 is 0.1%-3%.

[0058] The cholesteric liquid crystal composition of the present invention, preferably, the aforementioned cholesteric liquid crystal composition further comprises a nematic liquid crystal component consisting of one or more compounds of formula I, one or more compounds of formula II, one or more compounds of formula III and one or more compounds of formula IV,

[0059]

[0060]

[0061] in,

[0062] R5, R6, R9, R 10 Each independently represents a chain alkyl group having 1 to 10 carbon atoms; and R 10 One or more non-adjacent -CH2- in the group may be substituted by cyclopentylene or cyclopropylene;

[0063] R7 represents an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms;

[0064] R8 represents an alkenyl group having 2 to 10 carbon atoms;

[0065] X1, X2, X3, X4, X5, and X6 each independently represent H or F;

[0066] m means 1, 2 or 3;

[0067] n represents 0 or 1;

[0068] r represents 0, 1 or 2;

[0069] Z1 represents a single bond, -COO-, -OCO-;

[0070] Z2 represents a single bond, -COO-, -OCO-, -OCF2-, -CF2O-;

[0071] Each independently expresses

[0072] In the cholesteric liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula I is selected from the group consisting of compounds represented by the following formulas I1 to I3,

[0073]

[0074]

[0075] in,

[0076] R5 and R6 each independently represent an alkyl group having 1 to 10 carbon atoms.

[0077] In the cholesteric liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula II is selected from the group consisting of compounds represented by the following formulas II1 to II7:

[0078]

[0079] in,

[0080] R7 represents an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms.

[0081] In the cholesteric liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula III is selected from the group consisting of the compounds represented by the following formula III1 to III2,

[0082]

[0083] in,

[0084] R8 represents an alkenyl group having 2 to 10 carbon atoms;

[0085] R9 represents an alkyl group having 1 to 10 carbon atoms.

[0086] In the cholesteric liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula IV is selected from the group consisting of compounds represented by the following formulas IV1 to IV13,

[0087]

[0088]

[0089] in,

[0090] R 10 represents a chain alkyl group having 1 to 10 carbon atoms; and R 10 One or more non-adjacent -CH2- in the group may be substituted by cyclopentylene or cyclopropylene.

[0091] In the cholesteric liquid crystal composition of the present invention, preferably, the mass percentages of the compound represented by formula I, the compound represented by formula II, the compound represented by formula III, and the compound represented by formula IV in the nematic liquid crystal component can be arbitrarily proportioned according to actual needs.

[0092] The cholesteric liquid crystal composition of the present invention, preferably, further comprises one or more compounds represented by formula V,

[0093]

[0094] in,

[0095] R 11 , R 12 Each independently represents a chain alkyl group having 1 to 10 carbon atoms;

[0096] Z3 represents a single bond or —C≡C—.

[0097] In the cholesteric liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula V is selected from the group consisting of the compounds represented by the following formulas V1 to V2,

[0098]

[0099] in,

[0100] R 11 , R 12 Each independently represents an alkyl group having 1 to 10 carbon atoms.

[0101] In the cholesteric liquid crystal composition of the present invention, preferably, the mass percentages of the compound represented by formula I, the compound represented by formula II, the compound represented by formula III, the compound represented by formula IV, and the compound represented by formula V in the nematic liquid crystal component can be arbitrarily proportioned according to actual needs.

[0102] Various functional dopants may be added to the cholesteric liquid crystal compound of the present invention. The content of the dopant is preferably between 0.01% and 1%. Examples of such dopants include antioxidants and ultraviolet absorbers.

[0103] Antioxidants include,

[0104]

[0105] Here, t represents an integer from 1 to 10.

[0106] Light stabilizers include,

[0107]

[0108] [Liquid crystal display element or liquid crystal display]

[0109] The present invention also relates to a liquid crystal display element or a liquid crystal display comprising any one of the above-mentioned cholesteric liquid crystal compositions; the display element or the display is an active matrix display element or the display or a passive matrix display element or the display.

[0110] The cholesteric liquid crystal display element or cholesteric liquid crystal display of the present invention is preferably an active matrix addressed liquid crystal display element or liquid crystal display.

[0111] The liquid crystal display element or liquid crystal display comprising the cholesteric liquid crystal composition of the present invention has a higher reflectivity retention rate, a smaller decrease in reflectivity during the photochromic process, and has both a faster response speed and a faster UV color change speed.

[0112] Example

[0113] In order to explain the present invention more clearly, the present invention is further described below in conjunction with embodiments. It should be understood by those skilled in the art that the content specifically described below is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

[0114] Synthesis example

[0115] Synthesis Example 1 Preparation of Liquid Crystal Compound S1-1

[0116] The preparation route is as follows:

[0117]

[0118] Specific operation process of preparation:

[0119] Compound 100g (0.429mol) and compound 28.6g (0.195mol) was dissolved in 1L dichloromethane, and triethylamine 50g (0.494mol) and DMAP 4.8g (0.039mol) were added. The temperature was lowered to 0°C, and EDCI 94.6g (0.493mol) was added under stirring. After addition, the reaction was allowed to react overnight at room temperature. The reaction solution was added with 500ml water, and the phases were separated by extraction. The aqueous phase was extracted with 2x250ml dichloromethane, and the organic phases were combined, and 300ml saturated brine was added for washing, drying, and concentration. 200ml of anhydrous ethanol and 200ml of petroleum ether were added at room temperature for recrystallization, and the reaction was repeated once to obtain 62.5g of white solid S1-1 with a yield of 56%.

[0120] Synthesis Example 2 Preparation of Liquid Crystal Compound S1-2

[0121] The preparation route is as follows:

[0122]

[0123] Specific operation process of preparation:

[0124] Compound 98.4 g (0.429 mol), and compound 28.6g (0.195mol) was dissolved in 1L dichloromethane, and triethylamine 50g (0.494mol) and DMAP 4.8g (0.039mol) were added. The temperature was lowered to 0°C, and EDCI 94.6g (0.494mol) was added under stirring. After addition, the reaction was allowed to react overnight at room temperature. The reaction solution was added with 500ml water, and the phases were separated by extraction. The aqueous phase was extracted with 2x250ml dichloromethane, and the organic phases were combined, and 300ml saturated brine was added for washing, drying, and concentration. 200ml of anhydrous ethanol and 200ml of petroleum ether were added at room temperature for recrystallization, and the reaction was repeated once to obtain 49.8g of white solid S1-2 with a yield of 45%.

[0125] Synthesis Example 3 Preparation of Liquid Crystal Compound S11-1

[0126] The preparation route is as follows:

[0127]

[0128] Specific operation process of preparation:

[0129] Compound 51.9 g (0.252 mol) and compound 55.2g (0.229mol) was dissolved in a mixed solution of 500ml toluene and 100ml water, and 47.5g (0.343mol) of potassium carbonate and Pd-132 were added to replace nitrogen and refluxed for 2 hours. The temperature was lowered, 200ml of water and 300ml of toluene were added, and the phases were separated by extraction. The aqueous phase was extracted by adding 2x200ml of toluene, and the organic phases were combined, washed with 300ml of saturated brine, dried, and concentrated to obtain the compound. 73.8 g, yield 100%.

[0130] Compound 73.8g (0.229mol) and 11g (0.274mol) of sodium hydroxide were dissolved in a mixed solution of 700ml THF and 700ml water, and refluxed for 4 hours. The mixture was cooled to room temperature, the organic phase was concentrated, 500ml of ethyl acetate was added to the aqueous phase for extraction twice, the phases were separated, hydrochloric acid was added to the aqueous phase to adjust the pH to acidic, the filter cake was washed with water, 500mL of ethyl acetate was added to the filter cake for dissolution, 1x200mL of brine was washed, the phases were separated, the organic phase was dried, and concentrated to obtain the compound 65g, yield 92%.

[0131] Compound 65g (0.214mol) and compound 14.3g (0.097mol) was dissolved in 500ml of dichloromethane, and 25g (0.244mol) of triethylamine and 2.4g (0.0195mol) of DMAP were added. The mixture was cooled to 0°C and 46.8g (0.244mol) of EDCI was added under stirring. After addition, the reaction was allowed to proceed overnight at room temperature. 250ml of water was added to the reaction solution, and the phases were separated by extraction. 2x100ml of dichloromethane was added to the aqueous phase for extraction. The organic phases were combined, and 300ml of saturated brine was added for washing, drying, and concentration. Column chromatography was used for separation and purification to obtain 24.8g of white solid S11-1 with a yield of 35%.

[0132] Synthesis Example 4 Preparation of Liquid Crystal Compound S11-2

[0133] The preparation route is as follows:

[0134]

[0135] Specific operation process of preparation:

[0136] Compound 54.9 g (0.269 mol) and compound 59g (0.245mol) was dissolved in a mixed solution of 500ml toluene and 100ml water, and 50.8g (0.367mol) of potassium carbonate and Pd-132 were added to replace nitrogen and refluxed for 2 hours. The temperature was lowered, 200ml of water and 300ml of toluene were added, and the phases were extracted and separated. 2x200ml of toluene was added to the aqueous phase for extraction, and the organic phases were combined, washed with 300ml of saturated brine, dried, and concentrated to obtain the compound. 72.1 g, yield 92%.

[0137] Compound 72.1g (0.225mol) and 11g (0.27mol) of sodium hydroxide were dissolved in a mixed solution of 700ml THF and 700ml water, and refluxed for 4 hours. The mixture was cooled to room temperature, the organic phase was concentrated, 500ml of ethyl acetate was added to the aqueous phase for extraction twice, the phases were separated, hydrochloric acid was added to the aqueous phase to adjust the pH to acidic, the filter cake was washed with water, 500mL of ethyl acetate was added to the filter cake for dissolution, 1x200mL of brine was washed, the phases were separated, the organic phase was dried, and concentrated to obtain the compound 65.5g, yield 95%.

[0138] Compound 65.5 g (0.214 mol) and compound 14.3g (0.097mol) was dissolved in 500ml dichloromethane, and triethylamine 25g (0.244mol) and DMAP 2.4g (0.0195mol) were added. The temperature was lowered to 0°C, and EDCI 46.8g (0.244mol) was added under stirring. After addition, the reaction was allowed to react overnight at room temperature. The reaction solution was added with 250ml water, and the phases were separated by extraction. The aqueous phase was extracted with 2x100ml dichloromethane, and the organic phases were combined, washed with 300ml saturated brine, dried, and concentrated. Column chromatography was used for separation and purification to obtain 33.6g of white solid S11-2 with a yield of 48%.

[0139] Synthesis Example 5 Preparation of Liquid Crystal Compound S17-1

[0140] The preparation route is as follows:

[0141]

[0142] Specific operation process of preparation:

[0143] Add 11.3 g (0.282 mol) of sodium hydride (60%) and 150 ml of THF to the reaction flask, replace the nitrogen, cool to 0°C, and dropwise add the compound 63.1g (0.282mol) of THF solution 150ml. After addition, the temperature was controlled at 0℃ and stirred for 1 hour, and the compound was added dropwise 61.5g (0.256mol) of THF solution 300ml. After addition, react at room temperature for 2 hours. Add 400ml of NaHCO3 aqueous solution to quench the reaction, add 600ml of ethyl acetate to extract and separate the phases, extract the aqueous phase with 2x200mL of ethyl acetate, combine the organic phases, wash with 2x100mL of brine, separate the phases, dry the organic phase, and concentrate to obtain the compound 70.6 g, yield 89%.

[0144] Compound 70.6g (0.228mol) and 11g (0.274mol) of sodium hydroxide were dissolved in a mixed solution of 700ml THF and 700ml water, and refluxed for 4 hours. The mixture was cooled to room temperature, the organic phase was concentrated, 500ml of ethyl acetate was added to the aqueous phase for extraction twice, the phases were separated, hydrochloric acid was added to the aqueous phase to adjust the pH to acidic, the filter cake was washed with water, 500mL of ethyl acetate was added to the filter cake for dissolution, 1x200mL of brine was washed, the phases were separated, the organic phase was dried, and concentrated to obtain the compound 60.4g, yield 93.8%.

[0145] Compound 60.4 g (0.214 mol) and compound 14.3g (0.097mol) was dissolved in 500ml dichloromethane, and triethylamine 25g (0.244mol) and DMAP 2.4g (0.0195mol) were added. The temperature was lowered to 0°C, and EDCI 46.8g (0.244mol) was added under stirring. After the addition, the reaction was allowed to react overnight at room temperature. The reaction solution was added with 250ml water, and the phases were separated by extraction. The aqueous phase was extracted with 2x100ml dichloromethane, and the organic phases were combined, washed with 300ml saturated brine, dried, and concentrated. 200ml of anhydrous ethanol and 200ml of petroleum ether were added at room temperature for recrystallization, and the reaction was repeated once to obtain 32.7g of white solid S17-1 with a yield of 50%.

[0146] Synthesis Example 6 Preparation of Liquid Crystal Compound S18-1

[0147] The preparation route is as follows:

[0148]

[0149] Specific operation process of preparation:

[0150] Add 10.2 g (0.254 mol) of sodium hydride (60%) and 150 ml of THF to the reaction flask, replace the nitrogen, cool to 0°C, and dropwise add the compound 56.9g (0.254mol) of THF solution 150ml. After addition, the temperature was controlled at 0℃ and stirred for 1 hour, and the compound was added dropwise 55.5g (0.231mol) of THF solution 300ml. After addition, react at room temperature for 2 hours. Add 400ml of NaHCO3 aqueous solution to quench the reaction, add 600ml of ethyl acetate to extract and separate the phases, extract the aqueous phase with 2x200mL of ethyl acetate, combine the organic phases, wash with 2x100mL of brine, separate the phases, dry the organic phase, and concentrate to obtain the compound 68.8 g, yield 96%.

[0151] Compound 68.8g (0.222mol) and 11g (0.267mol) of sodium hydroxide were dissolved in a mixed solution of 700ml THF and 700ml water, and refluxed for 4 hours. The mixture was cooled to room temperature, the organic phase was concentrated, 500ml of ethyl acetate was added to the aqueous phase for extraction twice, the phases were separated, hydrochloric acid was added to the aqueous phase to adjust the pH to acidic, the filter cake was washed with water, 500mL of ethyl acetate was added to the filter cake for dissolution, 1x200mL of brine was washed, the phases were separated, the organic phase was dried, and concentrated to obtain the compound 60.4g, yield 96%.

[0152] Compound 60.4 g (0.214 mol) and compound 14.3g (0.097mol) was dissolved in 500ml dichloromethane, and triethylamine 25g (0.244mol) and DMAP 2.4g (0.0195mol) were added. The temperature was lowered to 0°C, and EDCI 46.8g (0.244mol) was added under stirring. After the addition, the reaction was allowed to react overnight at room temperature. The reaction solution was added with 250ml water, and the phases were separated by extraction. The aqueous phase was extracted with 2x100ml dichloromethane, and the organic phases were combined, washed with 300ml saturated brine, dried, and concentrated. 200ml of anhydrous ethanol and 200ml of petroleum ether were added at room temperature for recrystallization, and the reaction was repeated once to obtain 29.4g of white solid S18-1 with a yield of 45%.

[0153] The chiral agent compounds D1 to D5 used in the comparative examples are as follows:

[0154]

[0155] Performance test method of chiral agent compound

[0156] UV aging of chiral monomer: Sprinkle the chiral monomer evenly on a transparent glass plate and use 50mW / cm 2 Irradiate with a 365nm UV LED light source of high intensity for 1 hour;

[0157] Determination of the initial and post-UV chiral agent HTP value: Add 1% of the initial or UV-aged chiral compounds S1-1, S1-2, S11-1, S11-2, S17-1, S18-1 and D1~D5 to 100% of the mother liquid crystal and mix them evenly. Inject it into a slanted liquid crystal box (Cano box) with an inclination angle of 1° made of parallel rubbed glass sheets, observe under a polarizing microscope, and see regular Cano lines. Measure the spacing l between the two stripes, and determine the pitch P by the formula P=2ltanθ. The twisting force (HTP) value can be calculated by the following formula: HTP=1 / rPc, where c is the mass concentration of the chiral additive in the main material; r is the optical purity, which is usually regarded as 1;

[0158] Conversion time (s): Chiral compounds S1-1, S1-2, S11-1, S11-2, S17-1, S18-1 and D1-D5 of different concentrations were added to the mother liquid crystal (Table 1), the central wavelength was adjusted to 450nm, and the cholesteric liquid crystal was perfused into the ITO liquid crystal box without PI by capillary action. 2 The intensity of the 365nm UV LED light source was irradiated to 670nm, and the conversion time was recorded;

[0159] Solubility: Chiral compounds S1-1, S1-2, S11-1, S11-2, S17-1, S18-1 and D1 to D5 of different concentrations were added to the mother liquid crystal (Table 1) and stored at -20°C. After 10 days, their dissolution was observed and the maximum number of portions without crystallization was recorded.

[0160] The parent liquid crystal is shown in Table 1. Table 1 is only for example and does not represent a special limitation on the technical solution of the present application. The specific structure and mass percentage of each component can be changed according to actual test requirements.

[0161] Table 1

[0162] serial number structure Mass percentage Ⅰ UTPP-3-2 10 Ⅰ UTPP-3-4 10 Ⅰ UTPP-2-3 11 Ⅰ UTPP-4-3 9 Ⅱ PZG-2-N 5 Ⅱ PZG-4-N 5 Ⅱ PZG-3-N 5 Ⅱ PZU-V2-N 8 Ⅱ PZU-3-N 4 Ⅱ PZU-5-N 4 Ⅱ CCZU-3-N 4 Ⅱ CCZU-2-N 3 Ⅲ CC-3-V 7 Ⅳ PUQU-3-F 11 Ⅳ CPTP-3-2 4

[0163] Initial HTP (μm -1 )、HTP after UV(μm -1 ), conversion time (s) and solubility experimental data are shown in Table 2:

[0164] Table 2

[0165]

[0166] In summary, the chiral agent compound of the present invention has a good HTP value, and the performance of the chiral agent compound after UV is stable, the difference in HTP value before and after UV is small, and it also has good solubility and fast conversion time. Compared with the chiral agent compound of the present invention, the chiral agent compounds shown in D1 and D2 are similar to the structure of the present application, but the O atoms in the molecular structure of the chiral agent compounds of D1 and D2 are relatively concentrated, and the electron cloud density is concentrated, resulting in increased activity and reduced stability of the chiral agent molecules, especially after UV light, the chiral agent compounds D1 and D2 will decompose, resulting in a decrease in HTP value after UV, or even loss of chiral agent performance. Although the chiral agent compound shown in D3 is similar to the chiral agent compound of the present invention in structure, the electron donation ability of the alkyl or alkoxy group is weaker than that of the fluoroalkyl or fluoroalkoxy group, which reduces the electron cloud density on the benzene ring, resulting in a slow conversion time of the chiral agent molecule. The terminal group of the chiral agent compound shown in D4 is an alkyl or alkoxy group, which has a weaker electron-donating ability than a fluoroalkyl or fluoroalkoxy group, which reduces the electron cloud density on the benzene ring. In addition, the structure of the chiral agent compound shown in D4 is an asymmetric structure, which results in a slow conversion time of the chiral agent molecule. The chiral agent compound shown in D5 does not contain an ene ester bond, resulting in the loss of the function of a photosensitizer, and the conversion time is very long and cannot be tested.

[0167] Performance testing methods and examples of compositions

[0168] In this specification, unless otherwise specified, the preparation methods are conventional methods, the raw materials used are available from public commercial channels unless otherwise specified, the percentages are mass percentages, the temperatures are degrees Celsius (℃), and the specific meanings of other symbols and test conditions are as follows:

[0169] Cp represents the clearing point of liquid crystal (℃), measured by DSC quantitative method;

[0170] SN represents the melting point of the liquid crystal from the crystalline state to the nematic phase (°C);

[0171] Δn represents the optical anisotropy, n o is the refractive index of ordinary light, n e It is the refractive index of extraordinary light, tested at 25±2℃, 589nm, and Abbe refractometer.

[0172] Δε represents dielectric anisotropy, Δε=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 vertical box, INSTEC:ALCT-IR1 test;

[0173] The test method for the reflectivity retention rate of cholesteric liquid crystal is to use a Minolta CM-2600d colorimeter to test the planar reflectivity of the sample at a wavelength of 450nm. After the sample is driven, the sample is placed for 5 minutes before testing again. Then the sample is UV-irradiated to 670nm, and the above steps are repeated to test the planar reflectivity; reflectivity retention rate = 670nm sample planar reflectivity / 450nm sample planar reflectivity;

[0174] Reflection wavelength test: Cholesteric liquid crystal is perfused into the ITO liquid crystal box without PI through capillary action, and the reflection wavelength is tested using a liquid crystal comprehensive tester (DMS);

[0175] Reflection wavelength change test at different UV times: Cholesteric liquid crystal is perfused into an ITO liquid crystal box without PI by capillary action, using 50mW / cm 2 The samples were irradiated with a 365nm UV LED light source of different intensity for different time periods, and the reflection wavelength at 25°C was tested by a liquid crystal comprehensive tester (DMS), and then the reflection wavelength difference of the samples without UV irradiation was calculated respectively;

[0176] η represents fluid viscosity, test method: cone and plate viscometer test, test at room temperature 25°C and high temperature 60°C (maximum heating temperature of ODF equipment);

[0177] The preparation method of the cholesteric liquid crystal composition is as follows: each liquid crystal monomer and a chiral agent are weighed according to a certain ratio and put into a stainless steel beaker, and the stainless steel beaker containing each liquid crystal monomer is placed on a magnetic stirring instrument to heat and melt. After most of the liquid crystal monomers in the stainless steel beaker are melted, a magnetic rotor is added to the stainless steel beaker, and the mixture is stirred evenly. After cooling to room temperature, a liquid crystal composition is obtained.

[0178] The cholesteric liquid crystal monomer structure of the embodiment of the present invention is represented by a code, and the code representation method of the liquid crystal ring structure, end group, and connecting group is shown in Table 3 and Table 4 below.

[0179] Table 3 Structure code table

[0180]

[0181]

[0182] Table 4 Corresponding codes of terminal groups and linking groups

[0183]

[0184] Example:

[0185] Its code is CZP-3-N;

[0186] Its code is CC-3-V;

[0187] Its code is CP-3-O2;

[0188] Its code is PP-5-N;

[0189] Its code is PyG-5-N;

[0190] Its code is CCP-V-1;

[0191] Its code is CCU-2-F;

[0192] Its code is CPTP-3-2;

[0193] Its code is UTPP-2-3;

[0194] Its code is CCPU-3-F;

[0195] Its code is PPGU-Cp-F;

[0196] Its code is DUQU-Cp-F;

[0197] Its code is PGUQU-3-F;

[0198] Liquid crystal compositions 1 to 5 are prepared according to the above method for use, as shown in Table 5. The components listed in Table 5 are only examples and do not represent any special limitation on the technical solution of the present application. The specific structure and mass percentage of each component can be replaced according to actual test requirements.

[0199] Table 5

[0200]

[0201]

[0202] The composition and the chiral agent were weighed in a certain ratio and placed in a stainless steel beaker. The stainless steel beaker containing each liquid crystal monomer was placed on a magnetic stirring apparatus to heat and melt. After most of the liquid crystal monomers in the stainless steel beaker were melted, a magnetic rotor was added to the stainless steel beaker to stir the mixture evenly. After cooling to room temperature, a cholesteric liquid crystal composition was obtained, as shown in Table 6 and Table 7:

[0203] Table 6

[0204]

[0205] Table 7

[0206]

[0207]

[0208] In summary, the cholesteric liquid crystal composition provided by the present invention has a high reflectivity retention rate, and takes into account a low viscosity, especially the viscosity at 25°C and 60°C is moderate and can be adapted to ODF dripping. At the same time, the cholesteric liquid crystal composition of the present invention has a faster UV color change speed, which can reduce production costs. Furthermore, the liquid crystal display element or liquid crystal display comprising the cholesteric liquid crystal composition of the present invention has a high reflectivity retention rate, the reflectivity decreases less during the photochromic process, and has both a faster response speed and a faster UV color change speed.

[0209] Obviously, the above embodiments disclosed in the present invention are only examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made on the basis of the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A chiral agent compound, characterized in that: Selected from the following formula S, in, R1 and R2 each independently represent a fluorinated alkyl group having 1 to 5 carbon atoms, a fluorinated alkoxy group having 1 to 5 carbon atoms, a fluorinated alkenyl group having 2 to 5 carbon atoms, or a fluorinated alkenyloxy group having 2 to 5 carbon atoms; Each independently expresses Any hydrogen in the group may be replaced by halogen, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an alkenyloxy group having 2 to 10 carbon atoms; m and n each independently represent 1 or 2.

2. The chiral agent compound according to claim 1, characterized in that The chiral agent S is selected from the group consisting of compounds represented by the following formulas S1 to S18, in, R1 and R2 each independently represent a fluorinated alkyl group having 1 to 5 carbon atoms, a fluorinated alkoxy group having 1 to 5 carbon atoms, a fluorinated alkenyl group having 2 to 5 carbon atoms, or a fluorinated alkenyloxy group having 2 to 5 carbon atoms.

3. The chiral agent compound according to claim 2, characterized in that: The chiral agents S1 to S18 are selected from the group consisting of compounds represented by the following formulas S1-1 to S18-2, 4. A cholesteric liquid crystal composition, characterized in that: The cholesteric liquid crystal composition comprises one or more chiral agent compounds represented by formula S selected from any one of claims 1 to 3.

5. The cholesteric liquid crystal composition according to claim 4, characterized in that: The cholesteric liquid crystal composition at least comprises a chiral agent compound represented by formula S1-1.

6. The cholesteric liquid crystal composition according to any one of claims 4 or 5, characterized in that: The cholesteric liquid crystal composition further comprises one or more chiral agent compounds represented by formulas SA1 to SA5, in, R3 and R4 each independently represent an alkyl group having 1-6 carbon atoms, an alkyl group having 1-6 carbon atoms substituted with fluorine, an alkoxy group having 1-6 carbon atoms, an alkoxy group having 1-6 carbon atoms substituted with fluorine, an alkenyl group having 2-6 carbon atoms, an alkenyl group having 2-6 carbon atoms substituted with fluorine, an alkenyloxy group having 3-8 carbon atoms or an alkenyloxy group having 3-8 carbon atoms substituted with fluorine.

7. The cholesteric liquid crystal composition according to claim 6, characterized in that: The cholesteric liquid crystal composition comprises a chiral agent compound represented by formula S1-1 and at least one chiral agent compound represented by formulas SA1 to SA5.

8. The cholesteric liquid crystal composition according to claim 7, characterized in that: The mass percentage of the chiral agent compound S1-1 is 2%-6%, and the mass percentage of the chiral agent compounds SA1 to SA5 is 0.1%-3%.

9. The cholesteric liquid crystal composition according to claim 8, characterized in that: The cholesteric liquid crystal composition further comprises one or more compounds of formula I, one or more compounds of formula II, one or more compounds of formula III and one or more compounds of formula IV. in, R5, R6, R9, R 10 Each independently represents a chain alkyl group having 1 to 10 carbon atoms; and R 10 One or more non-adjacent -CH2- in the group may be substituted by cyclopentylene or cyclopropylene; R7 represents an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms; R8 represents an alkenyl group having 2 to 10 carbon atoms; X1, X2, X3, X4, X5, and X6 each independently represent H or F; m means 1, 2 or 3; n represents 0 or 1; r represents 0, 1 or 2; Z1 represents a single bond, -COO-, -OCO-; Z2 represents a single bond, -COO-, -OCO-, -OCF2-, -CF2O-; Each independently expresses 10. The cholesteric liquid crystal composition according to claim 9, characterized in that: The cholesteric liquid crystal composition further comprises one or more compounds represented by formula V, in, R 11 , R 12 Each independently represents a chain alkyl group having 1 to 10 carbon atoms; Z3 represents a single bond or —C≡C—.

11. A cholesteric liquid crystal display element, characterized in that: The cholesteric liquid crystal composition comprises any one of claims 1 to 10, wherein the cholesteric liquid crystal display element is an active matrix addressing display element or a passive matrix addressing display element.

12. A cholesteric liquid crystal display, characterized in that: A cholesteric liquid crystal composition comprising any one of claims 1 to 10, wherein the cholesteric liquid crystal display is an active matrix addressing display or a passive matrix addressing display.

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