Liquid crystal composition, liquid crystal display panel and display device

Abstract

The invention relates to a liquid crystal composition, a liquid crystal display panel and a display device.The liquid crystal composition comprises at least one compound represented by the formula I and at least one compound represented by the formula II, the compound represented by the formula I is a polymerizable compound, and the compound represented by the formula II is a non-polymerizable compound. A cross-linked network formed after polymerization of the polymerizable compound has high stability, and the reliability of the liquid crystal display panel and the display device can be effectively improved.

Description

Technical Field

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

[0002] Liquid crystal materials are widely used in various displays, including but not limited to mobile phones, televisions, computers, etc. Liquid crystals play the role of a "light valve" in a liquid crystal display panel (LCD). They control the amount of backlight transmitted by the deflection of liquid crystal molecules to achieve brightness adjustment of the liquid crystal display panel.

[0003] In a liquid crystal composition, a polymerizable compound (Reactive Monomer, RM) is usually added to stabilize the pretilt angle of liquid crystal molecules. The RM polymerizes under ultraviolet light irradiation to form a crosslinked network, which can enable the liquid crystal molecules to still maintain the pretilt angle formed by the action of an electric field after the applied voltage is removed, so as to improve the stability of the pretilt angle and achieve a stable display effect. However, during the ultraviolet light irradiation process and the long-term use process of the liquid crystal display panel, free radicals are generated. These free radicals can cause the polymer formed by the RM to undergo a depolymerization reaction, break up the polymer formed by the RM, and reduce the reliability of the liquid crystal display panel. Summary of the Invention

[0004] The present application provides a liquid crystal composition, a liquid crystal display panel, and a display device, which can improve the above problems and effectively enhance the reliability of the liquid crystal display panel and the display device.

[0005] The present application provides a liquid crystal composition, which includes at least one compound represented by Formula I and at least one compound represented by Formula II;

[0006] The chemical structural formulas of Formula I and Formula II are:

[0007]

[0008] Wherein, L 1 and L 2 are selected from -F, -Cl, -Br, -I, -CN, -NO2, -NCO, -NCS, -OCN, -SCN, -OH, a straight-chain or branched-chain alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, and any non-adjacent -CH2- in the L 1 and L 2 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 L 1 and L2 One or more H in the group are unsubstituted or substituted by F, Cl, Br or I, and at least one L in the compound represented by Formula I 1 or L 2 represents -OH;

[0009] Sp-P is selected from branched or unbranched ethers, alkyl groups, alkoxy groups, alkenyl groups, alkenyloxy groups, polymerizable groups, and at least one Sp-P in the compound represented by Formula I represents a polymerizable group;

[0010] Z 1 is selected from a single bond, -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, alkylene having 1-10 carbon atoms, alkenylene having 2-10 carbon atoms, alkynyl having 2-10 carbon atoms, and any non-adjacent -CH2- in the Z 1 group is unsubstituted or substituted by -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O-, -OCH2-, -CH=CH- or -C≡C-, and Z 1 one or more H in the group are unsubstituted or substituted by F, Cl, Br or I;

[0011] is selected from cyclohexane, cyclohexene or benzene ring, any H in is unsubstituted or substituted by F, Cl, Br, CN, SCN, NCS, alkyl or alkoxy group having 1-10 carbon atoms, alkenyl or alkenyloxy group having 2-10 carbon atoms, alkynyl or alkynyloxy group having 2-10 carbon atoms;

[0012] Ra and Rb are selected from -H, -F, -Cl, -Br, -CN, -SCN, -NCS, alkyl or alkoxy group having 1-10 carbon atoms, alkenyl or alkenyloxy group having 2-10 carbon atoms, alkynyl or alkynyloxy group having 2-10 carbon atoms, wherein the terminal group -CH3 or -H of Ra and Rb is unsubstituted or substituted by -CN or -CF3, one or more -CH2- in the Ra and Rb groups are unsubstituted or substituted by -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O-, -OCH2-, -CH=CH- or -C≡C- and heteroatoms are not directly bonded, and one or more H in the Ra and Rb groups are unsubstituted or substituted by F, Cl, Br or I;

[0013] p1 and p2 represent 1, 2 or 3;

[0014] r1 and r2 represent 0, 1, 2, or 3;

[0015] n represents an integer from 1 to 10.

[0016] In some embodiments, when Sp-P represents a polymerizable group, it is selected from the groups represented by Formula III or the groups represented by Formula IV;

[0017] The chemical structural formulas of Formula III and Formula IV are:

[0018]

[0019] Wherein,

[0020] P represents

[0021] Sp represents

[0022] d represents an integer from 0 to 10;

[0023] Z 2 is selected from a single bond, -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, an alkylene group having 1-10 carbon atoms, an alkenylene group having 2-10 carbon atoms, an alkynyl group having 2-10 carbon atoms, and for Z 2 any non-adjacent -CH2- in the 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 for Z 2 one or more H in the group is not substituted, or is substituted by F, Cl, Br, or I.

[0024] In some embodiments, the compound represented by Formula I is selected from the compounds represented by Formula I-A to Formula I-M:

[0025]

[0026] In some embodiments, the compound represented by Formula I is selected from the compounds represented by Formula I-1 or Formula I-2:

[0027]

[0028] Wherein, L 1 and L 2 are selected from a straight-chain or branched-chain alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, and for L 1 and L 2Any non-adjacent -CH2- in the 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-, L 1 and L 2 One or more H in the group are not substituted, or are substituted by F, Cl, Br or I.

[0029] In some embodiments, the compound represented by Formula I is selected from the compounds represented by Formula I-1-1 or Formula I-1-4:

[0030]

[0031] In some embodiments, the compound represented by Formula I is selected from the compounds represented by Formula II-A to Formula II-X:

[0032]

[0033] In some embodiments, the compound represented by Formula I is selected from any one of the following structures:

[0034]

[0035] In some embodiments, the mass of the compound represented by Formula I accounts for 0.01% to 1.50% of the total mass of the liquid crystal composition.

[0036] This application also provides a liquid crystal display panel, which includes:

[0037] A first substrate;

[0038] A second substrate, which is disposed opposite to the first substrate;

[0039] A liquid crystal layer, which is located between the first substrate and the second substrate;

[0040] Wherein, the liquid crystal layer includes the liquid crystal composition as described above.

[0041] This application also provides a display device, which includes the liquid crystal display panel as described above.

[0042] The present application provides a liquid crystal composition, a liquid crystal display panel, and a display device. The liquid crystal composition of the present application contains compounds represented by Formula I and Formula II. The compound represented by Formula I is a polymerizable compound, and the compound represented by Formula II is a liquid crystal monomer. Among them, the compound represented by Formula I includes a polymerizable group Sp-P, which can undergo a polymerization reaction to form a crosslinked network, so as to keep the liquid crystal molecules having a stable pretilt angle; at the same time, there is at least one L in the compound represented by Formula I 1 or L 2 represents -OH, and -OH can quench free radicals, which can avoid the depolymerization reaction of the polymer formed by the compound represented by Formula I, so that the crosslinked network formed after the polymerization of the compound represented by Formula I has high stability, can improve the stability of the pretilt angle of the liquid crystal molecules, and further can effectively improve the reliability of the liquid crystal display panel and the display device. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 FIG. is a schematic diagram of a liquid crystal display panel provided by an embodiment of the present application.

[0044] DESCRIPTION OF THE REFERENCE NUMERALS

[0045] 100 - liquid crystal display panel; 110 - first substrate; 120 - liquid crystal layer; 130 - second substrate. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0046] Next, the technical solutions in the embodiments of the present application will be described with reference to the accompanying drawings in the embodiments of the present application. The described technical solutions are only used to explain and illustrate the idea of the present application, and should not be regarded as a limitation on the protection scope of the present application.

[0047] In the present application, reference numerals and / or reference letters may be repeated in different embodiments. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or arrangements discussed.

[0048] The present application provides a liquid crystal composition, and the liquid crystal composition includes at least one compound represented by Formula I and at least one compound represented by Formula II;

[0049] The chemical structural formulas of Formula I and Formula II are as follows:

[0050]

[0051] Among them,

[0052] L 1 and L 2Selected from -F, -Cl, -Br, -I, -CN, -NO2, -NCO, -NCS, -OCN, -SCN, -OH, a straight-chain or branched alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, L 1 and L 2 In the group, any non-adjacent -CH2- is unsubstituted or substituted by -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O-, -OCH2-, -CH═CH- or -C≡C-, L 1 and L 2 One or more H in the group are unsubstituted or substituted by F, Cl, Br or I, and at least one L in the compound represented by formula I 1 or L 2 represents -OH;

[0053] Sp-P is selected from branched or unbranched ethers, alkyl groups, alkoxy groups, alkenyl groups, alkenyloxy groups, polymerizable groups, and at least one Sp-P in the compound represented by formula I represents a polymerizable group;

[0054] Z 1 is selected from a single bond, -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, an alkylene group having 1-10 carbon atoms, an alkenylene group having 2-10 carbon atoms, an alkynyl group having 2-10 carbon atoms, Z 1 In the group, any non-adjacent -CH2- is unsubstituted or substituted by -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O-, -OCH2-, -CH═CH- or -C≡C-, Z 1 One or more H in the group are unsubstituted or substituted by F, Cl, Br or I;

[0055] is selected from cyclohexane, cyclohexene or a benzene ring, Any H in is unsubstituted or substituted by F, Cl, Br, CN, SCN, NCS, an alkyl or alkoxy group having 1-10 carbon atoms, an alkenyl or alkenyloxy group having 2-10 carbon atoms, an alkynyl or alkynyloxy group having 2-10 carbon atoms, and when the compound represented by formula II contains multiple When there are multiple can be selected from different groups;

[0056] Ra and Rb are selected from -H, -F, -Cl, -Br, -CN, -SCN, -NCS, alkyl or alkoxy groups having 1 to 10 carbon atoms, alkenyl or alkenyloxy groups having 2 to 10 carbon atoms, alkynyl or alkynyloxy groups having 2 to 10 carbon atoms, wherein the terminal groups -CH3 or -H of Ra and Rb are unsubstituted or substituted by -CN or -CF3, one or more -CH2- groups in the Ra and Rb groups are unsubstituted or substituted by -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O-, -OCH2-, -CH═CH- or -C≡C- such that heteroatoms are not directly bonded, and one or more H atoms in the Ra and Rb groups are unsubstituted or substituted by F, Cl, Br, I;

[0057] p1 and p2 represent 1, 2 or 3;

[0058] r1 and r2 represent 0, 1, 2 or 3;

[0059] n represents an integer from 1 to 10.

[0060] The liquid crystal composition of the present application contains compounds represented by formula I and formula II. The compound represented by formula I is a polymerizable compound RM, and the compound represented by formula II is a liquid crystal monomer. Among them, at least one Sp-P in the compound represented by formula I represents a polymerizable group, and at least one L 1 or L 2 represents -OH. The polymerizable group Sp-P in the compound represented by formula I undergoes a polymerization reaction under ultraviolet light irradiation, forming a crosslinked network between the molecules of the compound represented by formula I, enabling the liquid crystal molecules to maintain the pretilt angle formed by the action of the electric field even after the applied voltage is removed, so as to improve the stability of the pretilt angle and achieve a stable display effect. The -OH in the compound represented by formula I can quench free radicals, avoid the depolymerization reaction of the polymer formed by the compound represented by formula I, and thus effectively improve the reliability of the liquid crystal display panel and the display device.

[0061] In the ultraviolet irradiation process of the liquid crystal composition of the prior art, a photoinitiator is usually used. The photoinitiator molecule absorbs ultraviolet light of a specific wavelength, transitions from the ground state to an excited singlet state, and then transforms to an excited triplet state through intersystem crossing. The photoinitiator molecule in the excited state forms highly reactive free radicals through the homolytic cleavage of chemical bonds. These free radicals will attack the polymer chains of the polymerized RM, break the covalent bonds of the polymer chains, and cause the polymer chains to gradually break, causing depolymerization reactions, and shredding the polymers formed by RM, resulting in reduced reliability of the liquid crystal display panel. In addition, during the long-term use of the liquid crystal display panel, the polymer materials in the liquid crystal are heated for a long time, and the chemical bond energy at the ends of the polymer chains will increase due to the heat. When the energy reaches a certain level, the chemical bonds at the ends of the chains will break, forming free radicals, attacking other polymer chains, such as polymers formed by RM, triggering a series of free radical chain reactions, and depolymerization reactions will occur, resulting in reduced reliability of the liquid crystal display panel.

[0062] In the present application, -OH is introduced into the compound represented by Formula I, which can quench free radicals and avoid the polymer formed by the compound represented by Formula I from undergoing depolymerization reaction. Free radicals have unpaired electrons, and their chemical properties are very active, while the oxygen atom in the hydroxyl group (-OH) has unshared electron pairs, and the hydroxyl group can provide its own electrons to the free radicals, so that the unpaired electrons of the free radicals are paired, forming a relatively stable substance, thereby quenching the free radicals, interrupting the free radical chain reaction, and preventing the depolymerization reaction from continuing. Hydroxyl groups can also form hydrogen bonds with free radicals, and the activity of the free radicals is reduced by the action of hydrogen bonds, making it difficult to induce depolymerization reaction again. At the same time, after forming hydrogen bonds, the mutual collision and reaction probability between free radicals will also be reduced, further reducing the possibility of depolymerization reaction. Therefore, the compound represented by Formula I is added in the liquid crystal composition of the present application, so that the cross-linked network formed after the compound represented by Formula I is polymerized has a higher stability, can improve the stability of the pre-tilt angle of the liquid crystal molecules, and then can effectively improve the reliability of the liquid crystal display panel and the display device.

[0063] In some embodiments, Sp-P represents a branched or unbranched ether, alkyl, alkoxy, alkenyl, alkenyloxy, or polymerizable group. When Sp-P represents a polymerizable group, it is selected from the group represented by Formula III or the group represented by Formula IV;

[0064] The chemical structural formulas of the formula III and the formula IV are:

[0065]

[0066] in,

[0067] P stands for

[0068] Sp stands for

[0069] d represents an integer from 0 to 10;

[0070] Z 2 is selected from a single bond, -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, an alkylene group having 1 - 10 carbon atoms, an alkenylene group having 2 - 10 carbon atoms, an alkynyl group having 2 - 10 carbon atoms, Z 2 any non - adjacent -CH2- in the 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-, Z 2 one or more H in the group is not substituted, or is substituted by F, Cl, Br, or I.

[0071] In the present application, when Sp - P represents a polymerizable group, its end contains a polymerizable structure P: The double bond contained in the above - mentioned polymerizable structure P can undergo a polymerization reaction, causing the molecules of the compound represented by Formula I to polymerize with each other, thereby forming a cross - linked network, improving the stability of the pre - tilt angle of liquid crystal molecules, and achieving a stable display effect.

[0072] Furthermore, the compound represented by Formula I is selected from the compounds represented by Formula I - A to Formula I - M:

[0073]

[0074] In some embodiments, the compound represented by Formula I is selected from the compounds represented by Formula I - I or Formula I - II:

[0075]

[0076] wherein, L 1 and L 2 are selected from a straight - chain or branched - chain alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, L 1 and L 2 any non - adjacent -CH2- in the 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-, L 1 and L 2 one or more H in the group is not substituted, or is substituted by F, Cl, Br, or I.

[0077] In the present application, free radicals are quenched by introducing -OH to the compound represented by Formula I, to avoid the depolymerization reaction of the polymer formed by the compound represented by Formula I. However, since the reactivity of -OH is relatively high, the number of -OH contained in the compound represented by Formula I should not be too large. Meanwhile, other L 1 or L 2 groups can be introduced to the benzene ring connected to -OH to increase steric hindrance, so as to reduce the reactivity of -OH and increase the stability of the compound represented by Formula I, thereby ensuring the stability of the liquid crystal composition.

[0078] In some embodiments, the compound represented by Formula I may be selected from the compounds represented by Formula I-1 or Formula I-4:

[0079]

[0080] In this embodiment, steric hindrance is provided by introducing a tert-butyl group to reduce the reactivity of the hydroxyl group, so as to increase the stability of the compound represented by Formula I, thereby ensuring the overall stability of the liquid crystal composition. The combination of the tert-butyl group and the hydroxyl group endows the compound represented by Formula I with appropriate stability, and at the same time makes the crosslinked network formed after the polymerization of the compound represented by Formula I have high stability, effectively improving the reliability while ensuring the performance of the liquid crystal composition.

[0081] Furthermore, the compound represented by Formula I is selected from the compounds represented by Formula II-A to Formula II-X:

[0082]

[0083] In some embodiments, the compound represented by Formula I is selected from any one of the following structures:

[0084]

[0085] In some embodiments, the mass of the compound represented by Formula I accounts for 0.01% to 1.50% of the total mass of the liquid crystal composition. When the content of the compound represented by Formula I is within the above range, the pretilt angle of the liquid crystal molecules has good stability and relatively excellent reliability. When the content of the compound represented by Formula I is lower than the above range, its content is too low, resulting in poor stability of the pretilt angle of the liquid crystal molecules and failing to improve the reliability of the liquid crystal display panel; when the content of the compound represented by Formula I is higher than the above range, there are too many polymerizable compounds, which are difficult to completely dissolve or require higher reaction conditions, and will affect the properties of the liquid crystal composition or increase the cost.

[0086] It should be noted that the liquid crystal composition described in this application may also contain other common compound components for liquid crystals. Those skilled in the art can formulate according to professional knowledge and device parameter requirements. After adding the compound of this application, it can be expected that the performance of the liquid crystal composition will be significantly improved, specifically reflected in the effective improvement of the stability and reliability of the liquid crystal composition.

[0087] This application also provides a preparation method of the compound represented by Formula I. Taking the compound represented by the following Formula I as an example, the synthesis route is as follows:

[0088]

[0089] The preparation methods of other compounds represented by Formula I can be synthesized by referring to the preparation method of the above compound.

[0090] This application also provides a liquid crystal display panel 100. Please refer to Figure 1 , the liquid crystal display panel 100 includes a first substrate 110, a second substrate 120 disposed opposite to the first substrate 110, and a liquid crystal layer 130 located between the first substrate 110 and the second substrate 120. Among them, the liquid crystal layer 130 includes the liquid crystal composition described above.

[0091] The first substrate 110 is an array substrate, including a first substrate and a first electrode layer. The first substrate includes thin film transistors, and the first electrode layer is located on the side of the first substrate close to the liquid crystal layer 130.

[0092] The second substrate 120 is a counter substrate, including a second substrate and a second electrode layer. The second electrode layer is located on the side of the second substrate close to the liquid crystal layer 130. In some embodiments, the second substrate 120 may be a color filter substrate.

[0093] The liquid crystal layer 130 is located between the first electrode layer and the second electrode layer. The liquid crystal in the liquid crystal layer 130 deflects under the action of the electric field between the first electrode layer and the second electrode layer to realize the image display of the liquid crystal display panel.

[0094] Among them, the liquid crystal layer 130 includes compounds represented by Formula I and Formula II. The compound represented by Formula I is a polymerizable compound, and the compound represented by Formula II is a liquid crystal monomer. The compound represented by Formula I includes a polymerizable group Sp-P, which can undergo a polymerization reaction to form a crosslinked network, enabling the liquid crystal molecules to maintain a stable pretilt angle. At the same time, the compound represented by Formula I contains -OH, and -OH can quench free radicals, preventing the polymer formed by the compound represented by Formula I from depolymerizing. As a result, the crosslinked network formed after the polymerization of the compound represented by Formula I has high stability, which can improve the stability of the pretilt angle of the liquid crystal molecules. Therefore, by using the liquid crystal composition of the present application, the reliability of the liquid crystal display panel can be effectively improved.

[0095] The liquid crystal display panel 100 may further include a first alignment layer and a second alignment layer. The first alignment layer is located on the side of the first substrate 110 facing the liquid crystal layer 130, and the second alignment layer is located on the side of the second substrate 120 facing the liquid crystal layer 130. The first alignment layer and the second alignment layer are used to control the orientation of the liquid crystal molecules to achieve image display of the liquid crystal display panel 100. The materials of the first alignment layer and the second alignment layer may be polyimide (PI) or other alignable organic polymers, and the present application does not make specific limitations.

[0096] The liquid crystal display panel 100 of the present application may be a vertical alignment (VA) type liquid crystal display panel, but is not limited thereto.

[0097] The present application also provides a display device, which includes the liquid crystal display panel as described above. The display device may be a watch, a mobile phone, a television, a computer, etc., but is not limited thereto.

[0098] The liquid crystal composition of the present application and its properties will be described below through specific examples.

[0099] Experimental method:

[0100] In the following examples, the preparation of the liquid crystal composition was carried out by a thermal dissolution method, including the following steps:

[0101] 1. Weigh each component liquid crystal compound by mass percentage using a balance. There is no specific requirement for the weighing and addition order. Usually, the liquid crystal compounds are weighed and mixed in the order of increasing melting point.

[0102] Among them, the mixing process of step 1 includes:

[0103] 1) First, mix the compounds represented by Formula II to obtain a mixture (i.e., liquid crystal host). In this step, mix them based on the total mass percentage of each compound represented by Formula II being 100%. When the liquid crystal monomer further includes other compounds, the other compounds are blended with the compounds represented by Formula II.

[0104] 2) Then, add the compound represented by Formula I to the above mixture to obtain a liquid crystal composition. In this step: mix based on the total mass percentage of the compound represented by Formula I and the mass percentage of the above mixture being 100%.

[0105] 2. Heat and stir the liquid crystal composition obtained in Step 1 at 60 - 100 °C to fully dissolve and mix each component.

[0106] 3. Cool to room temperature and encapsulate to obtain the target sample.

[0107] Unless otherwise specified, the percentages in the present invention are all 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 the extraordinary light; γ1 represents the rotational viscosity at 25 °C (unit: mPa·s); Δε represents the dielectric anisotropy at 25 °C, ε ⊥ represents the dielectric constant perpendicular to the long axis of the liquid crystal; K 11 represents the splay elastic coefficient, K 33 represents the bend elastic coefficient, and VHR represents the voltage holding ratio (%).

[0108] Example 1

[0109] The liquid crystal composition in this example includes:

[0110] The compound represented by Formula I: (Characterized by mass spectrometry [M + H] + : 397.3);

[0111] The compound represented by Formula II:

[0112]

[0113] Mix the above compounds according to the above experimental method to prepare a liquid crystal composition, and test the performance of the obtained liquid crystal composition. The contents of the above compounds and the relevant performance parameters of the liquid crystal composition formed by the above compounds are shown in Table 1.

[0114] Table 1 Component contents and performance parameters of the liquid crystal composition in Example 1

[0115]

[0116] Example 2

[0117] The liquid crystal composition in this example includes:

[0118] The compound represented by Formula I: (Characterized by mass spectrometry [M+H] + : 489.3);

[0119] The compound represented by Formula II:

[0120]

[0121] Other compounds:

[0122] Mix the above compounds according to the above experimental method to prepare a liquid crystal composition, and test the performance of the obtained liquid crystal composition. The contents of the above compounds and the relevant performance parameters of the liquid crystal composition formed by the above compounds are shown in Table 2.

[0123] Table 2 Component contents and performance parameters of the liquid crystal composition of Example 2

[0124]

[0125] Example 3

[0126] The liquid crystal composition in this example includes:

[0127] The compound represented by Formula I: (Characterized by mass spectrometry [M+H] + : 395.2);

[0128] The compound represented by Formula II:

[0129]

[0130] Mix the above compounds according to the above experimental method to prepare a liquid crystal composition, and test the performance of the obtained liquid crystal composition. The contents of the above compounds and the relevant performance parameters of the liquid crystal composition formed by the above compounds are shown in Table 3.

[0131] Table 3 Component contents and performance parameters of the liquid crystal composition of Example 3

[0132]

[0133] Comparative Example 1

[0134] The liquid crystal composition in this example includes:

[0135]

[0136]

[0137] The above-mentioned 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 contents of the above-mentioned compounds and the relevant performance parameters of the liquid crystal composition formed by the above-mentioned compounds are shown in Table 4.

[0138] Table 4 Component contents and performance parameters of the liquid crystal composition of Comparative Example 1

[0139]

[0140] Comparative Example 2

[0141] The liquid crystal composition in this example includes:

[0142]

[0143]

[0144] The above-mentioned 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 contents of the above-mentioned compounds and the relevant performance parameters of the liquid crystal composition formed by the above-mentioned compounds are shown in Table 5.

[0145] Table 5 Component contents and performance parameters of the liquid crystal composition of Comparative Example 2

[0146]

[0147] Comparative Example 3

[0148] The liquid crystal composition in this example includes:

[0149]

[0150]

[0151] The above-mentioned 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 contents of the above-mentioned compounds and the relevant performance parameters of the liquid crystal composition formed by the above-mentioned compounds are shown in Table 6.

[0152] Table 6 Component contents and performance parameters of the liquid crystal composition of Comparative Example 3

[0153]

[0154] The liquid crystal display panels were respectively prepared using the liquid crystal compositions of the above-mentioned Examples 1 to 3 and Comparative Examples 1 to 3. Among them, the manufacturing of the liquid crystal display panel includes four processes: 1. Forming a PI alignment layer on the surface of the substrate, namely the PI process; 2. Dropping liquid crystal composition droplets between the two substrates, namely the ODF process; 3. Applying a voltage to the substrate and performing the first ultraviolet light irradiation to form a certain pretilt angle of the liquid crystal composition between the substrates, namely the UV1 process; 4. Performing the second ultraviolet light irradiation on the liquid crystal composition to form a vertically aligned liquid crystal, namely the UV2 process.

[0155] The VHR values in the above Tables 1 to 6 refer to the voltage holding ratio measured after applying UV2 for 90 minutes.

[0156] From the experimental data of the above Examples 1 to 3 and Comparative Examples 1 to 3, it can be seen that the compound represented by Formula I was added more in the liquid crystal composition of Example 1 than in the liquid crystal composition of Comparative Example 1, and the VHR value of the liquid crystal display panel of Example 1 was significantly improved. The compound represented by Formula I was added more in the liquid crystal composition of Example 2 than in the liquid crystal composition of Comparative Example 2, and the VHR value of the liquid crystal display panel of Example 2 was significantly improved. The compound represented by Formula I was added more in the liquid crystal composition of Example 3 than in the liquid crystal composition of Comparative Example 3, and the VHR value of the liquid crystal display panel of Example 3 was significantly improved. In this application, the reliability is mainly characterized by the VHR value. From the above examples and comparative examples, it can be seen that when adding Formula I with different structures in the examples of this application, the reliability of the liquid crystal display panel is significantly improved.

[0157] The liquid crystal composition of this application contains the compounds represented by Formula I and Formula II. The compound represented by Formula I is a polymerizable compound, and the compound represented by Formula II is a liquid crystal monomer. Among them, the compound represented by Formula I includes a polymerizable group Sp-P, which can undergo a polymerization reaction to form a crosslinked network, so that the liquid crystal molecules maintain a stable pretilt angle; at the same time, there is at least one L in the compound represented by Formula I 1 or L 2 represents -OH, and -OH can quench free radicals, which can avoid the depolymerization reaction of the polymer formed by the compound represented by Formula I, so that the crosslinked network formed after the polymerization of the compound represented by Formula I has high stability, can improve the stability of the liquid crystal molecule pretilt angle, and therefore can effectively improve the reliability of the liquid crystal display panel and the display device.

[0158] In summary, although this application has been disclosed above with preferred embodiments, the above preferred embodiments are not intended to limit this application. Those of ordinary skill in the art can make various changes and modifications without departing from the spirit and scope of this application. Therefore, the protection scope of this application is subject to the scope defined by the claims.

Claims

1. A liquid crystal composition, characterized in that, Comprising: At least one compound represented by Formula I and at least one compound represented by Formula II; The chemical structural formulas of Formula I and Formula II are: Wherein, L 1 and L 2 selected from -F, -Cl, -Br, -I, -CN, -NO2, -NCO, -NCS, -OCN, -SCN, -OH, a straight-chain or branched alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, L 1 and L 2 any non-adjacent -CH2- groups in the group are unsubstituted or substituted by -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O-, -OCH2-, -CH═CH- or -C≡C-, L 1 and L 2 one or more H atoms in the group are unsubstituted or substituted by F, Cl, Br or I, and at least one L in the compound represented by Formula I 1 or L 2 represents -OH; Sp-P is selected from branched or unbranched ethers, alkyl groups, alkoxy groups, alkenyl groups, alkenoxy groups, polymerizable groups, and at least one of the compounds represented by Formula I has Sp-P representing a polymerizable group; Z 1 selected from a single bond, -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, an alkylene group having 1 to 10 carbon atoms, an alkenylene group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, Z 1 any non-adjacent -CH2- in the group is unsubstituted or is substituted by -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O-, -OCH2-, -CH═CH- or -C≡C-, Z 1 one or more H in the group is unsubstituted or is substituted by F, Cl, Br or I; Selected from cyclohexane, cyclohexene or benzene ring, any H therein is unsubstituted or substituted by F, Cl, Br, CN, SCN, NCS, an alkyl or alkoxy group having 1 - 10 carbon atoms, an alkenyl or alkenyloxy group having 2 - 10 carbon atoms, an alkynyl or alkynyloxy group having 2 - 10 carbon atoms; Ra and Rb are selected from -H, -F, -Cl, -Br, -CN, -SCN, -NCS, alkyl or alkoxy groups having 1-10 carbon atoms, alkenyl or alkenoxy groups having 2-10 carbon atoms, alkynyl or alkoxy groups having 2-10 carbon atoms. Among them, the terminal groups -CH3 or -H of Ra and Rb are not substituted, or are substituted by -CN or -CF3. One or more -CH2- in the Ra and Rb 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- to prevent heteroatoms from being directly bonded. One or more H in the Ra and Rb groups are not substituted, or are substituted by F, Cl, Br or I; p1 and p2 represent 1, 2 or 3; r1 and r2 represent 0, 1, 2 or 3; n represents an integer from 1 to 10.

2. The liquid crystal composition according to claim 1, wherein When Sp-P represents a polymerizable group, it is selected from the groups represented by Formula III or the groups represented by Formula IV; The chemical structural formulas of Formula III and Formula IV are: Wherein, P represents Sp represents d represents an integer from 0 to 10; Z 2 selected from a single bond, -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, an alkylene group having 1 to 10 carbon atoms, an alkenylene group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, Z 2 any non-adjacent -CH2- in the group is unsubstituted or substituted by -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O-, -OCH2-, -CH=CH- or -C≡C-, Z 2 one or more H in the group is unsubstituted or substituted by F, Cl, Br or I.

3. The liquid crystal composition according to claim 2, characterized in that, The compounds represented by Formula I are selected from the compounds represented by Formula I-A to Formula I-M:

4. The liquid crystal composition according to claim 1, characterized in that, The compounds represented by Formula I are selected from the compounds represented by Formula I-1 or Formula I-2: wherein, L 1 and L 2 are selected from straight-chain or branched alkyl groups having 1 to 5 carbon atoms, alkoxy groups having 1 to 5 carbon atoms, L 1 and L 2 any non-adjacent -CH2- groups in the group are unsubstituted or are substituted with -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O-, -OCH2-, -CH═CH- or -C≡C-, L 1 and L 2 one or more H atoms in the group are unsubstituted or are substituted with F, Cl, Br or I.

5. The liquid crystal composition according to claim 4, wherein The compounds represented by Formula I are selected from the compounds represented by Formula I-1-1 or Formula I-1-4:

6. The liquid crystal composition according to claim 5, characterized in that, The compounds represented by Formula I are selected from the compounds represented by Formula II-A to Formula II-X:

7. The liquid crystal composition according to claim 6, characterized in that, The compounds represented by Formula I are selected from any one of the following structures:

8. The liquid crystal composition according to any one of claims 1 to 7, characterized in that, The mass of the compound represented by Formula I accounts for 0.01% to 1.50% of the total mass of the liquid crystal composition.

9. A liquid crystal display panel, characterized in that, Comprising: A first substrate; A second substrate, disposed 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 according to claim 9.

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