Liquid crystal composition, liquid crystal display panel and display device

Abstract

The invention provides a liquid crystal composition, a liquid crystal display panel and a display device. The liquid crystal composition comprises one or more compounds represented by a formula I, one or more compounds represented by a formula II, one or more compounds represented by a formula III and one or more chiral agents. The liquid crystal composition comprises the compound represented by the formula III, self-alignment of liquid crystal can be achieved, a PI alignment layer does not need to be additionally arranged, the technological process of a liquid crystal display panel can be simplified, meanwhile, the liquid crystal composition further comprises a chiral agent, the penetration rate is high, and the display effect and performance of the liquid crystal display panel can be effectively improved.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular, to a liquid crystal composition, a liquid crystal display panel and a display device. Background Art

[0002] Liquid crystal display panels are widely used in various display products, such as watches, mobile phones, televisions and computers. Liquid crystal display panels (LCD) are based on the special properties of liquid crystal materials. They control the deflection of liquid crystal molecules through electric fields, thereby changing the transmittance of light, forming different light and dark patterns, and finally realizing the display of images.

[0003] For vertical alignment (VA) type liquid crystal display panels, when no electric field is applied, the liquid crystal arrangement direction in the VA type liquid crystal display panel is perpendicular to the substrate, and the incident light perpendicular to the substrate cannot pass through, presenting a good dark state effect. Therefore, VA type liquid crystal display panels usually have negative dielectric anisotropy (Δε) and higher contrast. Although VA type liquid crystal display panels have higher contrast than other types of liquid crystal display panels, their transmittance is lower, which affects the display effect and performance of the liquid crystal display panel.

[0004] Therefore, in order to improve the display effect and performance of liquid crystal display panels and to meet the continuous development of liquid crystal display panels, it is urgent to develop liquid crystal materials with higher transmittance. Summary of the invention

[0005] In view of this, the present application provides a liquid crystal composition, a liquid crystal display panel and a display device. The liquid crystal composition provided in the present application has a high transmittance while achieving liquid crystal self-alignment, which can effectively improve the display effect and performance of the liquid crystal display panel while simplifying the process.

[0006] The present application provides a liquid crystal composition, which comprises: one or more compounds represented by formula I, one or more compounds represented by formula II, one or more compounds represented by formula III, and one or more chiral agents;

[0007] The chemical structural formulas of Formula I, Formula II and Formula III are:

[0008]

[0009] Wherein, R1, R2, R3 and R4 independently represent -H, -F, -Cl, -Br, -I, -CN, -SCN, -NCS, -SF5, an alkyl or alkoxy group having 1 to 10 carbon atoms, an alkenyl or alkenyloxy group having 2 to 10 carbon atoms, or an alkynyl or alkynyloxy group having 2 to 10 carbon atoms, wherein the terminal groups -CH3 or -H of R1, R2, R3 and R4 are not substituted or are substituted by -CN or -CF3, and R1, R 2. One or more -CH2- in the R3 and R4 groups are not substituted, or are substituted by -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O, -OCH2-, -CH=CH- or -C≡C- so that the heteroatom is not directly bonded, and one or more H in the R1, R2, R3 and R4 groups are not substituted, or are substituted by F, Cl, Br or I;

[0010] Z represents -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O, -OCH2-, -CH=CH-, -C≡C-, an alkylene group having 1 to 10 carbon atoms, an alkenylene group having 2 to 10 carbon atoms, or an alkynyl group having 2 to 10 carbon atoms, any non-adjacent -CH2- in the Z group is not substituted or is substituted by -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O, -OCH2-, -CH=CH-, or -C≡C-, and one or more H in the Z group is not substituted or is substituted by F, Cl, Br, or I;

[0011] T represents a group that plays an anchoring role with the substrate;

[0012] Sp represents a branched or unbranched ether, alkyl, alkoxy, alkenyl, alkenyloxy or polymerizable group;

[0013] m, n, a and b are 0, 1, 2 or 3, and a+b≥1;

[0014] express

[0015] In the formula III, any H on the benzene ring is not substituted or is substituted by F, Cl, Br, CN, SCN, NCS, an alkyl or alkoxy group having 1 to 10 carbon atoms, an alkenyl or alkenyloxy group having 2 to 10 carbon atoms, or an alkynyl or alkynyloxy group having 2 to 10 carbon atoms.

[0016] In some embodiments, the T group has a structure represented by Formula X:

[0017]

[0018] The Sp group has a structure represented by Formula XI or Formula XII:

[0019]

[0020] Wherein, R5, R6 and R7 independently represent -H, -OH, -F, -Cl, -Br, -CN, -SCN, -NCS, an alkyl or alkoxy group having 1 to 10 carbon atoms, an alkenyl or alkenyloxy group having 2 to 10 carbon atoms, or an alkynyl or alkynyloxy group having 2 to 10 carbon atoms, wherein the terminal groups -CH3 or -H of R5, R6 and R7 are not substituted, or are substituted with -OH, -CN or -CF3, and one or more of the groups R5, R6 and R7 are Multiple -CH2- groups are not substituted, or are substituted by -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O, -OCH2-, -CH=CH-, or -C≡C- so that the heteroatoms are not directly bonded, one or more H in the R5, R6, and R7 groups are not substituted, or are substituted by F, Cl, Br, or I, and the terminal group of at least one of the R5, R6, and R7 groups contains a hydroxyl group;

[0021] Z1 and Z2 independently represent a single bond, -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O, -OCH2-, -CH=CH-, -C≡C-, an alkylene group having 1 to 10 carbon atoms, an alkenylene group having 2 to 10 carbon atoms, or an alkynyl group having 2 to 10 carbon atoms, any non-adjacent -CH2- in the Z1 and Z2 groups is not substituted or is substituted by -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O, -OCH2-, -CH=CH-, or -C≡C-, and one or more H in the Z1 and Z2 groups is not substituted or is substituted by F, Cl, Br, or I;

[0022] c and d are integers of 0-10.

[0023] In some embodiments, the formula III has a structure represented by any one of formulas IV to IX:

[0024]

[0025]

[0026] In some embodiments, the formula III has a structure represented by any one of formula IV-1 to formula IX-1:

[0027]

[0028]

[0029]

[0030] Among them, R8, R9 and R 10 R8, R9 and R 10 One or more -CH2- groups in the group are not substituted, or are substituted by -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O, -OCH2-, -CH=CH- or -C≡C- so that the heteroatom is not directly bonded, and R8, R9 and R 10 One or more H in the group is not substituted or is substituted by F, Cl, Br, or I.

[0031] In some embodiments, the chiral agent has a structure represented by any one of Formula C-1 to Formula C-27:

[0032]

[0033]

[0034] In some embodiments, the formula II has a structure represented by any one of formula II-1 to formula II-35:

[0035]

[0036]

[0037] In some embodiments, in the liquid crystal composition, the mass percentage of the compound represented by formula I ranges from 1% to 25%; the mass percentage of the compound represented by formula II ranges from 1% to 50%; the mass percentage of the compound represented by formula III ranges from 0.1% to 1.5%; and the mass percentage of the chiral agent ranges from 0.01% to 2.0%.

[0038] In some embodiments, the optical anisotropy value Δn of the liquid crystal composition is in the range of 0.12-0.17.

[0039] The present application also provides a liquid crystal display panel, the liquid crystal display panel comprising:

[0040] a first substrate;

[0041] a second substrate, arranged opposite to the first substrate;

[0042] a liquid crystal layer, located between the first substrate and the second substrate;

[0043] Wherein, the liquid crystal layer includes the liquid crystal composition as described above.

[0044] The present application also provides a display device, comprising the liquid crystal display panel as described above.

[0045] The liquid crystal composition of the present application includes compounds represented by formula I, formula II, and formula III and chiral agents, wherein the compounds represented by formula I and formula II are used as liquid crystal host materials (host), and can adjust the optical anisotropy (Δn), dielectric anisotropy (Δε), clearing point (Tni) and other physical properties of the liquid crystal composition, the compound represented by formula III is a self-alignment additive, which can undergo polymerization reaction to form an alignment layer on the surface of the substrate to achieve vertical alignment of the liquid crystal molecules, and the chiral agent has a helical structure, and when added to the liquid crystal composition, the liquid crystal molecules can produce a helical deflection in the horizontal direction. Therefore, under the cooperation of the compound represented by formula III and the chiral agent, the liquid crystal molecules can achieve vertical deflection, and can also achieve horizontal rotation, which can reduce light leakage, thereby effectively improving the transmittance of the liquid crystal display panel. The liquid crystal composition of the present application can achieve self-alignment of the liquid crystal without the need to set up an additional PI alignment layer, which can effectively improve the transmittance while simplifying the process of the liquid crystal display panel, thereby improving the display effect and performance of the liquid crystal display panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A schematic diagram of a liquid crystal display panel provided in an embodiment of the present application.

[0047] Description of reference numerals:

[0048] 100 - liquid crystal display panel; 110 - first substrate; 111 - first underlayer; 112 - first electrode layer; 120 - second substrate; 121 - second substrate; 122 - second electrode layer; 130 - liquid crystal layer; 131 - liquid crystal molecules; 141 - rigid groups; 142 - T groups; 143 - Sp groups. DETAILED DESCRIPTION

[0049] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. The described technical solutions are only used to explain and illustrate the ideas of the present application and should not be regarded as limiting the scope of protection of the present application.

[0050] The present application may repeat reference numerals and / or reference letters in different implementations. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various implementations and / or settings discussed.

[0051] The liquid crystal composition, liquid crystal display panel and display device provided in the present application will be described in detail below in conjunction with specific embodiments and drawings.

[0052] The present application provides a liquid crystal composition, which comprises: one or more compounds represented by formula I, one or more compounds represented by formula II, one or more compounds represented by formula III, and one or more chiral agents;

[0053] The chemical structural formulas of Formula I, Formula II and Formula III are:

[0054]

[0055] Wherein, R1, R2, R3 and R4 independently represent -H, -F, -Cl, -Br, -I, -CN, -SCN, -NCS, -SF5, an alkyl or alkoxy group having 1 to 10 carbon atoms, an alkenyl or alkenyloxy group having 2 to 10 carbon atoms, or an alkynyl or alkynyloxy group having 2 to 10 carbon atoms, wherein the terminal groups -CH3 or -H of R1, R2, R3 and R4 are not substituted or are substituted by -CN or -CF3, and R1, R 2. One or more -CH2- in the R3 and R4 groups are not substituted, or are substituted by -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O, -OCH2-, -CH=CH- or -C≡C- so that the heteroatom is not directly bonded, and one or more H in the R1, R2, R3 and R4 groups are not substituted, or are substituted by F, Cl, Br or I;

[0056] Z represents -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O, -OCH2-, -CH=CH-, -C≡C-, an alkylene group having 1 to 10 carbon atoms, an alkenylene group having 2 to 10 carbon atoms, or an alkynyl group having 2 to 10 carbon atoms, any non-adjacent -CH2- in the Z group is not substituted or is substituted by -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O, -OCH2-, -CH=CH-, or -C≡C-, and one or more H in the Z group is not substituted or is substituted by F, Cl, Br, or I;

[0057] T represents a group that plays an anchoring role with the substrate;

[0058] Sp represents a branched or unbranched ether, alkyl, alkoxy, alkenyl, alkenyloxy or polymerizable group;

[0059] m, n, a and b are 0, 1, 2 or 3, and a and b are not 0 at the same time;

[0060] express

[0061] In formula III, any H on the benzene ring is unsubstituted or substituted by F, Cl, Br, CN, SCN, NCS, an alkyl or alkoxy group having 1 to 10 carbon atoms, an alkenyl or alkenyloxy group having 2 to 10 carbon atoms, or an alkynyl or alkynyloxy group having 2 to 10 carbon atoms.

[0062] In some embodiments, R1, R2, R3 and R4 independently represent -H, -F, -CN, -SCN, an alkyl or alkoxy group having 1-5 carbon atoms, or an alkenyl or alkenyloxy group having 2-5 carbon atoms, wherein one or more -CH2- in the R1, R2, R3 and R4 groups is not substituted, or is substituted by -O-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O, -OCH2-, -CH=CH- or -C≡C- so that the heteroatom is not directly bonded, and one or more H in the R1, R2, R3 and R4 groups is not substituted, or is substituted by F, Cl, Br, or I.

[0063] In some embodiments, m and n are 0 or 1.

[0064] In some embodiments, a and b are 0, 1 or 2, and a+b≥1.

[0065] The liquid crystal composition of the present application contains compounds represented by Formula I and Formula II. The compounds represented by Formula I and Formula II serve as liquid crystal host materials (host). The combination of the two can adjust the optical anisotropy (Δn), dielectric anisotropy (Δε), clearing point (Tni) and other physical properties of the liquid crystal composition. Among them, the compound represented by Formula I is a neutral compound, which can adjust the optical anisotropy (Δn) and clearing point (Tni) of the liquid crystal composition. For example, the more the number of rings in the compound represented by Formula I, the higher the Tni, and the more the number of benzene rings in the compound represented by Formula I, the higher the Δn; the compound represented by Formula II is a negative dielectric anisotropy compound and has a higher optical anisotropy (Δn).

[0066] The liquid crystal composition of the present application also contains a compound represented by formula III, which is a self-aligning additive that can undergo a polymerization reaction to form an alignment film on the surface of the substrate to achieve vertical alignment of the liquid crystal molecules. It is a rigid group, a rod-like structure, and has sufficient rigidity, a stable structure and is conducive to the alignment of liquid crystals; the benzene ring of the compound represented by Formula III is connected with a T group and a Sp group, the T group is used to anchor with the substrate surface, so that the self-alignment additive molecules can be anchored on the substrate surface, and the Sp group is a polymerizable group, which can undergo polymerization reaction with the polymer monomer (RM) and form a pre-tilt angle under the action of an electric field to achieve the alignment of liquid crystals. Since the compound represented by Formula III can be anchored on the substrate, a polymer film is deposited on the substrate surface to achieve the alignment of liquid crystals. Therefore, there is no need to set up an additional PI alignment layer, which eliminates the PI process in the liquid crystal display panel process in the prior art, and simplifies the process of the liquid crystal display panel.

[0067] The liquid crystal composition of the present application also includes a chiral agent. The addition of the chiral agent can improve the optical anisotropy (Δn) of the liquid crystal composition, and the transmittance of the liquid crystal composition is related to the optical anisotropy (Δn). The larger the Δn, the greater the transmittance. Therefore, the addition of the chiral agent can improve the transmittance. For ordinary VA-type liquid crystal display panels, the liquid crystal molecules will only produce vertical deflection under the action of voltage, and there are gaps between the patterned electrodes on the surface of the substrate, and there will still be light leakage in the electrode gaps. The liquid crystal composition of the present application adds a chiral agent, and the chiral agent has a spiral structure. The addition of the chiral agent can make the liquid crystal molecules produce a spiral deflection in the horizontal direction under the action of voltage. Therefore, the liquid crystal molecules of the present application can be deflected vertically and rotated horizontally, which makes up for the light leakage in the electrode gaps under the existing VA mode. Since the light leakage is reduced, the transmittance of the liquid crystal display panel can be effectively improved.

[0068] The present application combines the self-aligning additive represented by formula III with a chiral agent to achieve vertical alignment of the liquid crystal molecules while enabling the liquid crystal molecules to have the ability to rotate horizontally, thereby reducing light leakage and improving transmittance. The liquid crystal composition of the present application can further improve the display effect and performance of the liquid crystal display panel while simplifying the process of the liquid crystal display panel.

[0069] The optical anisotropy value Δn of the liquid crystal composition of the present application is in the range of 0.12-0.17. The optical anisotropy value Δn of the existing self-aligned liquid crystal composition is usually around 0.1 (e.g., 0.09-0.11), while the optical anisotropy value Δn of the liquid crystal composition of the present application is greater than the optical anisotropy value Δn of the existing self-aligned liquid crystal composition, and the greater the Δn, the greater the transmittance, proving that the self-aligned additive represented by Formula III and the chiral agent in the present application can effectively improve the transmittance.

[0070] In some embodiments, the T group has a structure represented by Formula X:

[0071]

[0072] Wherein, R5, R6 and R7 independently represent -H, -OH, -F, -Cl, -Br, -CN, -SCN, -NCS, an alkyl or alkoxy group having 1 to 10 carbon atoms, an alkenyl or alkenyloxy group having 2 to 10 carbon atoms, or an alkynyl or alkynyloxy group having 2 to 10 carbon atoms, wherein the terminal groups -CH3 or -H of R5, R6 and R7 are not substituted, or are substituted with -OH, -CN or -CF3, and one or more of the groups R5, R6 and R7 are Multiple -CH2- groups are not substituted, or are substituted by -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O, -OCH2-, -CH=CH-, or -C≡C- so that the heteroatoms are not directly bonded, one or more H in the R5, R6, and R7 groups are not substituted, or are substituted by F, Cl, Br, or I, and the terminal group of at least one of the R5, R6, and R7 groups contains a hydroxyl group;

[0073] Z1 represents a single bond, -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O, -OCH2-, -CH=CH-, -C≡C-, an alkylene group having 1 to 10 carbon atoms, an alkenylene group having 2 to 10 carbon atoms, or an alkynyl group having 2 to 10 carbon atoms, any non-adjacent -CH2- in the Z1 group is not substituted or is substituted by -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O, -OCH2-, -CH=CH-, or -C≡C-, and one or more H in the Z1 group is not substituted or is substituted by F, Cl, Br, or I;

[0074] c is an integer from 0 to 10.

[0075] In the present application, the terminal of the T group represented by formula X has a hydroxyl group, which can be combined with the hydroxyl group on the surface of the substrate of the liquid crystal display panel through hydrogen bonding. Therefore, the compound represented by formula III can be stably anchored on the surface of the substrate through chemical bonds, so that the compound represented by formula III can achieve stable alignment, which can further improve the display effect and performance of the liquid crystal display panel.

[0076] In some embodiments, the Sp group has a structure represented by Formula XI or Formula XII:

[0077]

[0078] Wherein, Z2 represents a single bond, -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O, -OCH2-, -CH=CH-, -C≡C-, an alkylene group having 1-10 carbon atoms, an alkenylene group having 2-10 carbon atoms, or an alkynyl group having 2-10 carbon atoms, any non-adjacent -CH2- in the Z2 group is not substituted, or is substituted by -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O, -OCH2-, -CH=CH-, or -C≡C-, and one or more H in the Z2 group is not substituted, or is substituted by F, Cl, Br, or I;

[0079] d is an integer from 0 to 10.

[0080] In the present application, the Sp group represented by formula XI has a methacrylate group at the end, and the Sp group represented by formula XII has an acrylate group at the end. The methacrylate group or the acrylate group has good polymerizability and can undergo polymerization reaction with the double bonds on the polymer monomer (RM) to form a cross-linked network to form an alignment film on the substrate surface and align the liquid crystal molecules, replacing the PI alignment layer. Among them, the polymer monomer (RM) can be a polymer monomer (RM) material commonly used in the art, and is not limited here. The polymer monomer (RM) can be added to the liquid crystal composition as an additive and mixed with the liquid crystal composition for use.

[0081] In some embodiments, Formula III has a structure represented by any one of Formula IV to Formula IX:

[0082]

[0083] In some embodiments, Formula III has a structure represented by any one of Formula IV-1 to Formula IX-1:

[0084]

[0085]

[0086]

[0087]

[0088] Among them, R8, R9 and R 10 R8, R9 and R 10 One or more -CH2- groups in the group are not substituted, or are substituted by -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O, -OCH2-, -CH=CH- or -C≡C- so that the heteroatom is not directly bonded, and R8, R9 and R 10 One or more H in the group is not substituted or is substituted by F, Cl, Br, or I.

[0089] The present application also provides a method for preparing the compound represented by formula III.

[0090] The preparation steps are as follows:

[0091]

[0092] It should be noted that the preparation methods of other compounds represented by formula III can refer to this method, and the principles are the same, which will not be described in detail here.

[0093] In some embodiments, the chiral agent has a structure represented by any one of Formula C-1 to Formula C-27:

[0094]

[0095]

[0096] The liquid crystal composition of the present application may contain one or more chiral agents represented by Formula C-1 to Formula C-27. The chiral agents represented by Formula C-1 to Formula C-27 all have a helical structure. When added to the liquid crystal composition, the liquid crystal molecules can simultaneously achieve helical deflection in the horizontal direction. The chiral agents represented by Formula C-1 to Formula C-27, in combination with the compound represented by Formula III, can effectively improve the transmittance of the liquid crystal composition and enhance the display effect.

[0097] In some embodiments, Formula II has a structure represented by any one of Formula II-1 to Formula II-35:

[0098]

[0099]

[0100] In some embodiments, in the liquid crystal composition, the mass percentage of the compound represented by Formula I ranges from 1% to 25%; the mass percentage of the compound represented by Formula II ranges from 1% to 50%; the mass percentage of the compound represented by Formula III ranges from 0.1% to 1.5%; and the mass percentage of the chiral agent ranges from 0.01% to 2.0%.

[0101] In the liquid crystal composition, the compound represented by formula III is a self-aligning additive used to achieve the alignment of the liquid crystal. When the mass percentage of the compound represented by formula III is in the range of 0.1% to 1.5%, the liquid crystal composition has a good alignment ability. When the compound represented by formula III in the liquid crystal composition is too little, it will lead to insufficient anchoring force and poor liquid crystal alignment, affecting the performance of the liquid crystal display panel. When the compound represented by formula III in the liquid crystal composition is too much, it will lead to insolubility, explosion, etc., causing the liquid crystal display panel to have problems such as bright spots and black spots.

[0102] In the liquid crystal composition, the addition of a chiral agent gives the liquid crystal a spiral structure. The content of the chiral agent affects the pitch of the liquid crystal, and the pitch of the liquid crystal affects the transmittance. When the mass percentage of the chiral agent is in the range of 0.01% to 2.0%, the liquid crystal composition has a good transmittance improvement effect. When there is too little chiral agent in the liquid crystal composition, the effect of improving the transmittance may be poor. When there is too much chiral agent in the liquid crystal composition, the transmittance of the display panel may also be reduced.

[0103] In the liquid crystal composition, the compound represented by formula I and the compound represented by formula II are used to adjust the physical properties of the liquid crystal composition, and their content can be set according to the actual performance requirements of the liquid crystal display panel. When the mass percentage range of the compound represented by formula I, the compound represented by formula II, the compound represented by formula III and the chiral agent is within the above range, the mutual coordination of each component makes the liquid crystal composition have better transmittance, better optical anisotropy (Δn), and suitable clearing point (Tni), suitable rotational viscosity (γ1) and other properties to meet the requirements of the liquid crystal display panel.

[0104] It should be noted that the liquid crystal composition of the present application may also contain other common liquid crystal compound components, and those skilled in the art may prepare them according to professional knowledge and device parameter requirements.

[0105] See also Figure 1 The present application also provides a liquid crystal display panel 100, which includes a first substrate 110, a second substrate 120 arranged opposite to the first substrate 110, and a liquid crystal layer 130 located between the first substrate 110 and the second substrate 120, wherein the liquid crystal layer 130 includes the liquid crystal composition as described above.

[0106] The first substrate 110 may be an array substrate, including a first substrate 111 and a first electrode layer 112. The first substrate 111 includes a thin film transistor, and the first electrode layer 112 is located on a side of the first substrate 111 close to the liquid crystal layer 130.

[0107] The second substrate 120 is a counter substrate, and includes a second substrate 121 and a second electrode layer 122. The second electrode layer 122 is located on a side of the second substrate 121 close to the liquid crystal layer 130. The second substrate 120 may be a color filter substrate, but is not limited thereto.

[0108] The liquid crystal layer 130 is located between the first electrode layer 112 and the second electrode layer 122 . Liquid crystal molecules 131 in the liquid crystal layer 130 are deflected under the action of the electric field between the first electrode layer 112 and the second electrode layer 122 , so as to realize image display of the liquid crystal display panel.

[0109] The liquid crystal layer 130 includes the above-mentioned liquid crystal composition, which includes compounds represented by formula I, formula II, and formula III and a chiral agent. Among them, the compounds represented by formula I and formula II are used as liquid crystal host materials (host), which can adjust the optical anisotropy (Δn), dielectric anisotropy (Δε), clearing point (Tni) and other physical properties of the liquid crystal composition. The compound represented by formula III is a self-alignment additive. The structure of formula III includes a rigid group 141 and a T group 142 and a Sp group 143 located at both ends of the rigid group 141. The T group 142 is used to anchor with the surface of the first substrate 110 and the second substrate 120, so that the self-alignment additive molecules are anchored on the surface of the first substrate 110 and the second substrate 120. The Sp group 143 is a polymerizable group that can undergo a polymerization reaction with a polymer monomer (RM) and form a pre-tilt angle under the action of an electric field to achieve the alignment of the liquid crystal molecules 131. The chiral agent has a helical structure. When added to the liquid crystal composition, the liquid crystal molecules 131 can produce a helical deflection in the horizontal direction. In the liquid crystal composition of the present application, the compound represented by formula III cooperates with the chiral agent, and the liquid crystal molecule 131 can realize vertical deflection and horizontal rotation, which can reduce light leakage at the electrode gap, thereby effectively improving the transmittance of the liquid crystal display panel. The liquid crystal composition of the present application can realize self-alignment of liquid crystal without the need to set up an additional PI alignment layer, which can effectively improve the transmittance while simplifying the process of the liquid crystal display panel, thereby improving the display effect and performance of the liquid crystal display panel.

[0110] The liquid crystal display panel 100 of the present application may be a vertical alignment (VA) type liquid crystal display panel, such as a polymer stabilized vertical alignment (PSVA) type liquid crystal display panel, a multi-domain vertical alignment (MVA) type liquid crystal display panel, etc., but is not limited thereto.

[0111] The present application also provides a display device, the display device comprising the above liquid crystal display panel. The display device can be a watch, a mobile phone, a television, a computer, etc., but is not limited thereto.

[0112] The liquid crystal composition of the present application and its properties are described below through specific examples.

[0113] Experimental methods:

[0114] In the following embodiments, the liquid crystal composition is prepared by a thermal dissolution method, which includes the following steps:

[0115] 1. Weigh the liquid crystal compounds of each component by mass percentage using a balance. There is no specific requirement for the order of weighing and adding. Usually, the liquid crystal compounds are weighed and mixed in order from low to high melting points;

[0116] Wherein, the mixing process of step 1 includes:

[0117] 1) First, a compound represented by formula I, a compound represented by formula II and other liquid crystal compounds are mixed to obtain a mixture (i.e., a liquid crystal host). In this step, the sum of the mass percentage of the compound represented by formula I, the mass percentage of the compound represented by formula II and the mass percentage of the other liquid crystal compounds is 100% for mixing;

[0118] 2) Then, the compound represented by formula III and the chiral agent are sequentially added to the above mixture to obtain a liquid crystal composition. In this step, the mixture is mixed with the sum of the mass percentage of the mixture obtained in step 1) and the mass percentage of the compound represented by formula III and the chiral agent being 100%.

[0119] 2. Heat and stir the liquid crystal mixture obtained in step 1 at 60-100° C. to fully dissolve and mix the components.

[0120] 3. Cool to room temperature and encapsulate to obtain the target sample.

[0121] Unless otherwise specified, percentages in the present invention are weight percentages, and the temperature unit is °C; Tni represents the clearing point of the liquid crystal composition (unit: °C); Δn represents the optical anisotropy at 25 °C, n e is the refractive index of extraordinary light; γ1 represents the rotational viscosity at 25°C (unit: mPa·s); Δε represents the dielectric anisotropy at 25°C, ε ⊥ is the dielectric constant perpendicular to the long axis of the liquid crystal; K 11 represents the splay elastic coefficient, K 33 It represents the bending elastic coefficient; Pitch represents the pitch of the liquid crystal; Tr represents the transmittance at 25℃.

[0122] Example 1

[0123] The liquid crystal composition in this embodiment includes:

[0124] The compound represented by formula I:

[0125] The compound represented by formula II:

[0126] Other liquid crystal compounds:

[0127] The compound represented by formula III:

[0128] Chiral agent:

[0129] The above compounds were mixed according to the above experimental method to prepare a liquid crystal composition, and the performance of the obtained liquid crystal composition was tested. The content of each of the above compounds and the relevant performance parameters of the liquid crystal composition formed by the above compounds are shown in Table 1.

[0130] Table 1 Contents of components and performance parameters of the liquid crystal composition of Example 1

[0131]

[0132] Example 2

[0133] The liquid crystal composition in this embodiment includes:

[0134] The compound represented by formula I:

[0135]

[0136] The compound represented by formula II:

[0137] Other liquid crystal compounds:

[0138] The compound represented by formula III:

[0139]

[0140] Chiral agent:

[0141] The above compounds were mixed according to the above experimental method to prepare a liquid crystal composition, and the performance of the obtained liquid crystal composition was tested. The content of each of the above compounds and the relevant performance parameters of the liquid crystal composition formed by the above compounds are shown in Table 2.

[0142] Table 2 Contents of components and performance parameters of the liquid crystal composition of Example 2

[0143]

[0144]

[0145] Example 3

[0146] The liquid crystal composition in this embodiment includes:

[0147] The compound represented by formula I:

[0148] The compound represented by formula II:

[0149] Other liquid crystal compounds:

[0150] The compound represented by formula III:

[0151]

[0152] Chiral agent:

[0153] The above compounds were mixed according to the above experimental method to prepare a liquid crystal composition, and the performance of the obtained liquid crystal composition was tested. The content of each of the above compounds and the relevant performance parameters of the liquid crystal composition formed by the above compounds are shown in Table 3.

[0154] Table 3 Contents of components and performance parameters of the liquid crystal composition of Example 3

[0155]

[0156]

[0157] Example 4

[0158] The liquid crystal composition in this embodiment includes:

[0159] The compound represented by formula I: The compound represented by formula II:

[0160] Other liquid crystal compounds:

[0161] The compound represented by formula III:

[0162]

[0163] Chiral agent:

[0164] The above compounds were mixed according to the above experimental method to prepare a liquid crystal composition, and the performance of the obtained liquid crystal composition was tested. The content of each of the above compounds and the relevant performance parameters of the liquid crystal composition formed by the above compounds are shown in Table 4.

[0165] Table 4 Contents of components and performance parameters of the liquid crystal composition of Example 4

[0166]

[0167]

[0168] Comparative Example

[0169] The liquid crystal composition in this embodiment includes:

[0170] The compound represented by formula I:

[0171] The compound represented by formula II:

[0172] Other liquid crystal compounds:

[0173]

[0174] The above compounds were mixed according to the above experimental method to prepare a liquid crystal composition (the compound represented by Formula III and the chiral agent were not added in the preparation method of the liquid crystal composition of the comparative example), and the performance of the obtained liquid crystal composition was tested. The content of each of the above compounds and the relevant performance parameters of the liquid crystal composition formed by the above compounds are shown in Table 5.

[0175] Table 5 Contents of components and performance parameters of liquid crystal compositions of comparative examples

[0176]

[0177]

[0178] Among them, in the above experiments, the three processes for manufacturing the liquid crystal display panel in Examples 1 to 4 include: 1. dripping liquid crystal composition droplets between the two substrates, namely the ODF process; 2. applying voltage to the substrates and performing the first ultraviolet irradiation to make the liquid crystal composition between the substrates form a certain pretilt angle, namely the UV1 process; 3. performing the second ultraviolet irradiation on the liquid crystal composition to complete the polymer reaction in the liquid crystal composition to form a liquid crystal vertically aligned relative to the substrate surface, namely the UV2 process.

[0179] In the above experiment, the four processes for manufacturing the liquid crystal display panel in the comparative example include: 1. forming a PI alignment layer on the surface of the substrate, namely the PI process; 2. dripping droplets of liquid crystal composition between the two substrates, namely the ODF process; 3. applying voltage to the substrates and performing the first ultraviolet irradiation to make the liquid crystal composition between the substrates form a certain pretilt angle, namely the UV1 process; 4. performing the second ultraviolet irradiation on the liquid crystal composition to form a vertically aligned liquid crystal, namely the UV2 process.

[0180] Compared with the comparative example, Examples 1 to 4 omit a PI process, which proves that the liquid crystal composition of the present application containing the compound represented by Formula III can achieve self-alignment of liquid crystal without a PI alignment layer.

[0181] It can be seen from the data of Example 1 and the comparative example that the liquid crystal composition of Example 1 contains the compound represented by Formula III and the chiral agent, and the liquid crystal composition of the comparative example does not contain the compound represented by Formula III and the chiral agent. Compared with the comparative example, the Δn value and the transmittance (Tr) of the liquid crystal composition of Example 1 are improved, and Example 1 omits a PI process relative to the comparative example, which proves that the combination of the compound represented by Formula III and the chiral agent in the liquid crystal composition of the present application can simultaneously achieve the improvement of liquid crystal self-alignment and transmittance.

[0182] From the data of Examples 1 to 4 and the comparative example, it can be seen that the Δn value of Example 1 is 0.1509, the Δn value of Example 2 is 0.1439, the Δn value of Example 3 is 0.1277, and the Δn value of Example 4 is 0.1356. The Δn values ​​of the liquid crystal compositions of Examples 1 to 4 are significantly greater than the optical anisotropy value Δn of the existing self-aligned liquid crystal compositions (Δn is usually around 0.1 when no chiral agent is added); and the Tr value of Example 1 is 6.69%, the Tr value of Example 2 is 6.58%, the Tr value of Example 3 is 6.47%, and the Tr value of Example 4 is 6.33%. The transmittance Tr values ​​of the liquid crystal compositions of Examples 1 to 4 are significantly greater than the Tr value of 6.05% of the comparative example, which proves that the addition of the chiral agent increases the optical anisotropy value Δn of the liquid crystal composition and effectively improves the transmittance of the liquid crystal composition.

[0183] From the data of Examples 1 to 4, it can be seen that the more the amount of chiral agent added in the liquid crystal compositions of Examples 1 to 4, the smaller the pitch value of the liquid crystal, which will lead to a decrease in transmittance. Therefore, the amount of chiral additive added to the liquid crystal composition should not be too much. The liquid crystal composition of the present application has a good transmittance when the chiral agent content is in the range of 0.01% to 2.0%.

[0184] In summary, although the present application has been disclosed as above with preferred embodiments, the above preferred embodiments are not intended to limit the present application. Ordinary technicians in this field can make various changes and modifications without departing from the spirit and scope of the present application. Therefore, the scope of protection of the present application shall be based on the scope defined in the claims.

Claims

1. A liquid crystal composition, characterized in that: The liquid crystal composition comprises: one or more compounds represented by formula I, one or more compounds represented by formula II, one or more compounds represented by formula III and one or more chiral agents; The chemical structural formulas of Formula I, Formula II and Formula III are: Wherein, R1, R2, R3 and R4 independently represent -H, -F, -Cl, -Br, -I, -CN, -SCN, -NCS, -SF5, an alkyl or alkoxy group having 1 to 10 carbon atoms, an alkenyl or alkenyloxy group having 2 to 10 carbon atoms, or an alkynyl or alkynyloxy group having 2 to 10 carbon atoms, wherein the terminal groups -CH3 or -H of R1, R2, R3 and R4 are not substituted or are substituted by -CN or -CF3, and R1, R 2. One or more -CH2- in the R3 and R4 groups are not substituted, or are substituted by -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O, -OCH2-, -CH=CH- or -C≡C- so that the heteroatom is not directly bonded, and one or more H in the R1, R2, R3 and R4 groups are not substituted, or are substituted by F, Cl, Br or I; Z represents -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O, -OCH2-, -CH=CH-, -C≡C-, an alkylene group having 1 to 10 carbon atoms, an alkenylene group having 2 to 10 carbon atoms, or an alkynyl group having 2 to 10 carbon atoms, any non-adjacent -CH2- in the Z group is not substituted or is substituted by -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O, -OCH2-, -CH=CH-, or -C≡C-, and one or more H in the Z group is not substituted or is substituted by F, Cl, Br, or I; T represents a group that plays an anchoring role with the substrate; Sp represents a branched or unbranched ether, alkyl, alkoxy, alkenyl, alkenyloxy or polymerizable group; m, n, a and b are 0, 1, 2 or 3, and a+b≥1; express In the formula III, any H on the benzene ring is not substituted or is substituted by F, Cl, Br, CN, SCN, NCS, an alkyl or alkoxy group having 1 to 10 carbon atoms, an alkenyl or alkenyloxy group having 2 to 10 carbon atoms, or an alkynyl or alkynyloxy group having 2 to 10 carbon atoms.

2. The liquid crystal composition according to claim 1, characterized in that: The T group has a structure represented by formula X: The Sp group has a structure represented by Formula XI or Formula XII: Wherein, R5, R6 and R7 independently represent -H, -OH, -F, -Cl, -Br, -CN, -SCN, -NCS, an alkyl or alkoxy group having 1 to 10 carbon atoms, an alkenyl or alkenyloxy group having 2 to 10 carbon atoms, or an alkynyl or alkynyloxy group having 2 to 10 carbon atoms, wherein the terminal groups -CH3 or -H of R5, R6 and R7 are not substituted, or are substituted with -OH, -CN or -CF3, and one or more of the groups R5, R6 and R7 are Multiple -CH2- groups are not substituted, or are substituted by -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O, -OCH2-, -CH=CH-, or -C≡C- so that the heteroatoms are not directly bonded, one or more H in the R5, R6, and R7 groups are not substituted, or are substituted by F, Cl, Br, or I, and the terminal group of at least one of the R5, R6, and R7 groups contains a hydroxyl group; Z1 and Z2 independently represent a single bond, -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O, -OCH2-, -CH=CH-, -C≡C-, an alkylene group having 1 to 10 carbon atoms, an alkenylene group having 2 to 10 carbon atoms, or an alkynyl group having 2 to 10 carbon atoms, any non-adjacent -CH2- in the Z1 and Z2 groups is not substituted or is substituted by -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O, -OCH2-, -CH=CH-, or -C≡C-, and one or more H in the Z1 and Z2 groups is not substituted or is substituted by F, Cl, Br, or I; c and d are integers of 0-10.

3. The liquid crystal composition according to claim 2, characterized in that: The formula III has a structure represented by any one of formulas IV to IX:

4. The liquid crystal composition according to claim 3, characterized in that: The formula III has a structure represented by any one of formula IV-1 to formula IX-1: Among them, R8, R9 and R 10 R8, R9 and R 10 One or more -CH2- groups in the group are not substituted, or are substituted by -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O, -OCH2-, -CH=CH- or -C≡C- so that the heteroatom is not directly bonded, and R8, R9 and R 10 One or more H in the group is not substituted or is substituted by F, Cl, Br, or I.

5. The liquid crystal composition according to claim 1, characterized in that: The chiral agent has a structure represented by any one of Formula C-1 to Formula C-27:

6. The liquid crystal composition according to claim 1, characterized in that: The formula II has a structure represented by any one of formula II-1 to formula II-35:

7. The liquid crystal composition according to any one of claims 1 to 6, characterized in that: In the liquid crystal composition, the mass percentage range of the compound represented by formula I is 1% to 25%; the mass percentage range of the compound represented by formula II is 1% to 50%; the mass percentage range of the compound represented by formula III is 0.1% to 1.5%; the mass percentage range of the chiral agent is 0.01% to 2.0%.

8. The liquid crystal composition according to any one of claims 1 to 6, characterized in that: The optical anisotropy value Δn of the liquid crystal composition is in the range of 0.12-0.

17.

9. A liquid crystal display panel, characterized in that: include: a first substrate; a second substrate, arranged opposite to the first substrate; a liquid crystal layer, located between the first substrate and the second substrate; Wherein, the liquid crystal layer comprises the liquid crystal composition according to any one of claims 1 to 8.

10. A display device, characterized in that: Comprising the liquid crystal display panel as claimed in claim 9.

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