Liquid crystal composition, optical film, polaroid and display device

Abstract

The invention relates to a liquid crystal composition, an optical film, a polaroid and a display device, the liquid crystal composition is applied to a random depolarization functional layer, and the liquid crystal composition comprises a polymerizable liquid crystal material, the polymerizable liquid crystal material comprises at least one first liquid crystal compound as shown in a formula I and / or at least one second liquid crystal compound as shown in a formula II. The liquid crystal composition provided by the invention can be used for manufacturing a random depolarization functional layer, so that linearly polarized light is randomly converted into circularly polarized light and / or elliptically polarized light; therefore, the display device applying the random depolarization function layer realizes healthy eye-protection display.

Description

Technical Field

[0001] This application relates to the field of display technology, and more particularly to a liquid crystal composition, an optical film, a polarizer, and a display device. Background Technology

[0002] Currently, Thin Film Transistor Liquid Crystal Displays (TFT-LCDs) are widely used in various display fields due to their low price, good size compatibility, high resolution, and long lifespan. TFT-LCD products include, but are not limited to, mobile phones, televisions, monitors, and laptops. In TFT-LCDs, the backlight is used for emission, while the liquid crystal acts as a "light valve," controlling the amount of backlight transmitted to adjust the brightness of the display device.

[0003] Typically, natural light is linearly polarized by the lower polarizer of a TFT-LCD. This linearly polarized light then undergoes birefringence by the liquid crystal molecules, transforming into elliptically polarized light. Finally, it passes through the upper polarizer, whose polarization axis is perpendicular to that of the lower polarizer, and exits as linearly polarized light. However, the linearly polarized light emitted from display devices can cause significant damage to the macula of the viewer's retina. Prolonged exposure to linearly polarized light can lead to retinal damage and impaired vision. Therefore, achieving eye-friendly displays is a pressing issue that needs to be addressed. Summary of the Invention

[0004] This application provides a liquid crystal composition, an optical film, a polarizer, and a display device. The liquid crystal composition can be used to fabricate a random polarization depolarization functional layer, thereby randomly converting linearly polarized light into circularly polarized light and / or elliptically polarized light, enabling the display device with the random polarization depolarization functional layer to achieve eye-friendly display.

[0005] To achieve the above objectives, according to a first aspect of this application, a liquid crystal composition is provided, the liquid crystal composition comprising a polymeric liquid crystal material, the polymeric liquid crystal material comprising at least one first liquid crystal compound of formula I and / or at least one second liquid crystal compound of formula II:

[0006]

[0007]

[0008] Wherein, P is selected from

[0009] Sp is selected from any one or more combinations of single bond, -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O-, -OCH2-, alkylene group having 1 to 10 carbon atoms, alkenyl group having 2 to 10 carbon atoms, and alkynyl group having 2 to 10 carbon atoms. In Sp, any one or more -CH2- groups are not substituted or are substituted by any one of -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -OC(O)O-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O-, -OCH2-, -CH=CH-, and -C≡C-. In Sp, any one or more H groups are not substituted or are substituted by any one of F, Cl, Br, and I.

[0010] A and B are selected from substituted or unsubstituted aromatic rings, heteroaromatic rings, aliphatic rings, or fused ring groups. At least one of A and B represents a substituted or unsubstituted 1,4-phenylene. One or more H atoms in A and B are unsubstituted or substituted with L. L is selected from F, Cl, Br, I, CN, NO2, NCO, NCS, OCN, SCN, and any straight-chain or branched alkyl group having 1 to 8 carbon atoms. One or more H atoms in the straight-chain or branched alkyl group having 1 to 8 carbon atoms are unsubstituted or substituted with F or C. l is substituted, wherein the -CH2- in the straight-chain or branched alkyl group having 1 to 8 carbon atoms is unsubstituted or substituted by any one of -O-, -S-, -SO-, -COO-, -OCO-, -CO-S-, -S-CO-, -O-CO-O-, -CO-NR-, -NR-CO-, -CR=CR-, -CR=N-, -N=CR-, -N=N-, -CR=NN=CR- and -C≡C-, and R is selected from H, F or an alkyl group having 1 to 10 carbon atoms;

[0011] n is any integer from 1 to 5;

[0012] Z is selected from single bonds, alkylene groups having 1 to 10 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, alkynyl groups having 2 to 10 carbon atoms, -O-, -S-, -CHR'-, -CHR'CHR'-, -OCHR'-, -CHR'O-, -OCHR'O-, -SO-, -SO2-, -COO-, -OCO-, -CO-S-, -S-CO-, -O-CO-O-, -CO-NR'-, -NR'-CO-, -SCHR'-, -CHR'S-, -SO-CHR'-, -CHR'-SO-, -SO2-CHR'-, -CHR'-SO2-, -CF2O-, -OCF2-, -CF2S-, -SCF2-, -OCHR'CHR'O-, -SCHR'CHR'S -, -SO-CHR'CHR'-SO-, -SO2-CHR'CHR'-SO2-, -CH=CH-COO-, -CH=CH-OCO-, -COO-CH=CH-, -OCO-CH=CH-, -COO-CHR'CHR'-, -OCO-CHR'CHR'-, -CHR'CHR'-COO-, -CHR'CHR'-OCO-, -COO-CHR'-, -OCO-CHR'-, -CHR'-COO-, -CHR'-OCO-, -CR'=CR'-, -CR'=N-, -N=CR'-, -N=N-, -CR'=NN=CR- or -CF=CF-, where R' is selected from H or an alkyl group having 1 to 10 carbon atoms, and any one of the H atoms in Z is unsubstituted or substituted. Replace any one of them;

[0013] Q is selected from H,

[0014] X is selected from H, OH, F, Cl, Br, CN, SCN, NCS, alkyl having 1 to 10 carbon atoms, alkoxy having 1 to 10 carbon atoms, alkenyl having 2 to 10 carbon atoms, alkenoxy having 2 to 10 carbon atoms, alkynyl having 2 to 10 carbon atoms, and alkynoxy having 2 to 10 carbon atoms; one or more -CH2- in X are unsubstituted or substituted by L', where L' is selected from -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -OC(O)O-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O-, -OCH2-, -CH=CH-, and -C≡C-; one or more H in L' are unsubstituted or substituted by F, Cl, Br, and I.

[0015] m and y are any integers from 1 to 8.

[0016] According to a second aspect of this application, an optical film is provided, the optical film comprising a substrate layer and a random depolarization functional layer disposed on one side of the substrate layer, wherein linearly polarized light incident on the optical film passes through the random depolarization functional layer, and at least a portion of the linearly polarized light is converted into circularly polarized light or elliptically polarized light.

[0017] The material of the random polarization depolarization functional layer includes the polymer of the polymeric liquid crystal material in the liquid crystal composition described above, or the random polarization depolarization functional layer is made of the liquid crystal composition described above.

[0018] According to a third aspect of this application, a polarizer is also provided, the polarizer comprising a polarizing functional layer and the optical film described above, the optical film being disposed on the light-emitting side of the polarizing functional layer.

[0019] According to a fourth aspect of this application, a display device is also provided, the display device including a display panel and the optical film described above, the optical film being disposed on the light-emitting side of the display panel; or, the display device including the display panel and the polarizer described above, the polarizer being disposed on the light-emitting side of the display panel, and the optical film being disposed on the side of the polarizing functional layer opposite to the display panel.

[0020] In the liquid crystal composition, optical film, polarizer, and display device of this application embodiment, the liquid crystal composition includes a polymerizable liquid crystal material, and the polymerizable liquid crystal material includes at least one first liquid crystal compound represented by Formula I and / or at least one second liquid crystal compound represented by Formula II. Since both the first liquid crystal compound represented by Formula I and the second liquid crystal compound represented by Formula II have birefringence, the random depolarization functional layer prepared using the first liquid crystal compound represented by Formula I and / or the second liquid crystal compound represented by Formula II can randomly convert linearly polarized light incident on the random depolarization functional layer into circularly polarized light and / or elliptically polarized light, thereby enabling the display device using this random depolarization functional layer to achieve eye-friendly display. Furthermore, since both the first liquid crystal compound represented by Formula I and the second liquid crystal compound represented by Formula II contain polymerizable groups P, the process of preparing the random depolarization functional layer using polymerizable liquid crystal materials is simple, low-cost, and has a high yield. Therefore, this application can achieve the random depolarization effect through a simpler, lower-cost, and higher-yield method, thereby achieving an eye-protecting effect.

[0021] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0024] Figure 1 This is a schematic diagram of the structure of an optical film provided in an embodiment of this application;

[0025] Figure 2 This is a schematic diagram of another optical film structure provided in an embodiment of this application;

[0026] Figure 3 This is a schematic diagram of the structure of a polarizer provided in an embodiment of this application;

[0027] Figure 4 This is a schematic diagram of another polarizer structure provided in an embodiment of this application;

[0028] Figure 5 This is a schematic diagram of the structure of a display device provided in an embodiment of this application.

[0029] Explanation of reference numerals in the attached figures:

[0030] 1. Optical film; 2. Substrate layer; 3. Random polarization correction layer; 4. Orientation layer; 5. Polarizer; 6. Polarizing functional layer; 7. First adhesive layer; 8. Polarizing layer; 9. Second adhesive layer; 10. Compensation layer; 11. Release film; 12. Display device; 13. Display panel; 14. Lower polarizer; 15. Backlight module. Detailed Implementation

[0031] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0032] The optical, electrical, and mechanical properties of liquid crystal molecules depend on their structure and substituents. These properties are determined by the refractive index n along the long axis of the liquid crystal molecule. e and the refractive index n along the minor axis o There are differences (Δn=n) e -n oLiquid crystal molecules (i.e., they possess birefringence) can alter the polarization state of light. Utilizing the birefringence of liquid crystal molecules, optical films prepared by controlling the alignment and formulation of these molecules are applied to polarizers and display devices, achieving random depolarization and thus providing eye protection.

[0033] This application provides a liquid crystal composition and an optical film prepared using the liquid crystal composition. The optical film is attached to or integrated into an upper polarizer and applied to a display device. This converts linearly polarized light emitted from the display panel into circularly polarized light and / or ellipsoidally polarized light, achieving a random depolarization effect and thus realizing the purpose of eye-friendly display. Please refer to the following description of the embodiments for details.

[0034] It should be noted that random depolarization refers to breaking the regularity of the polarization state of light, making the polarization state of light random and uniform. In other words, it makes the polarization direction of light, which was originally relatively concentrated, approximately uniformly distributed at various angles, thereby reducing the degree of polarization of light.

[0035] This application provides a liquid crystal composition comprising a polymeric liquid crystal material, wherein the polymeric liquid crystal material comprises at least one first liquid crystal compound of Formula I and / or at least one second liquid crystal compound of Formula II.

[0036]

[0037] Wherein, P is selected from

[0038] Sp is selected from any one or more combinations of single bonds, -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O-, -OCH2-, alkylene groups having 1 to 10 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, and alkynyl groups having 2 to 10 carbon atoms. In Sp, any one or more -CH2- atoms are not substituted or are substituted by any one of -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -OC(O)O-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O-, -OCH2-, -CH=CH-, and -C≡C-. In Sp, any one or more H (hydrogen atoms) are not substituted or are substituted by any one of F, Cl, Br, and I.

[0039] A and B are selected from substituted or unsubstituted aromatic rings, heteroaromatic rings, aliphatic rings, or fused ring groups. At least one of A and B represents a substituted or unsubstituted 1,4-phenylene. One or more H atoms in A and B are unsubstituted or substituted with L. L is selected from F, Cl, Br, I, CN, NO2, NCO, NCS, OCN, SCN, and any straight-chain or branched alkyl group having 1 to 8 carbon atoms. One or more H atoms in the straight-chain or branched alkyl group having 1 to 8 carbon atoms are unsubstituted or substituted with F or C. l is substituted, wherein the -CH2- in the straight-chain or branched alkyl group having 1 to 8 carbon atoms is unsubstituted or substituted by any one of -O-, -S-, -SO-, -COO-, -OCO-, -CO-S-, -S-CO-, -O-CO-O-, -CO-NR-, -NR-CO-, -CR=CR-, -CR=N-, -N=CR-, -N=N-, -CR=NN=CR- and -C≡C-, and R is selected from H, F or an alkyl group having 1 to 10 carbon atoms;

[0040] n is any integer from 1 to 5;

[0041] Z is selected from single bonds, alkylene groups having 1 to 10 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, alkynyl groups having 2 to 10 carbon atoms, -O-, -S-, -CHR'-, -CHR'CHR'-, -OCHR'-, -CHR'O-, -OCHR'O-, -SO-, -SO2-, -COO-, -OCO-, -CO-S-, -S-CO-, -O-CO-O-, -CO-NR'-, -NR'-CO-, -SCHR'-, -CHR'S-, -SO-CHR'-, -CHR'-SO-, -SO2-CHR'-, -CHR'-SO2-, -CF2O-, -OCF2-, -CF2S-, -SCF2-, -OCHR'CHR'O-, -SCHR'CHR'S -, -SO-CHR'CHR'-SO-, -SO2-CHR'CHR'-SO2-, -CH=CH-COO-, -CH=CH-OCO-, -COO-CH=CH-, -OCO-CH=CH-, -COO-CHR'CHR'-, -OCO-CHR'CHR'-, -CHR'CHR'-COO-, -CHR'CHR'-OCO-, -COO-CHR'-, -OCO-CHR'-, -CHR'-COO-, -CHR'-OCO-, -CR'=CR'-, -CR'=N-, -N=CR'-, -N=N-, -CR'=NN=CR- or -CF=CF-, where R' is selected from H or an alkyl group having 1 to 10 carbon atoms, and any one of the H atoms in Z is unsubstituted or substituted. Replace any one of them;

[0042] Q is selected from H,

[0043] X is selected from H, OH, F, Cl, Br, CN, SCN, NCS, alkyl having 1 to 10 carbon atoms, alkoxy having 1 to 10 carbon atoms, alkenyl having 2 to 10 carbon atoms, alkenoxy having 2 to 10 carbon atoms, alkynyl having 2 to 10 carbon atoms, and alkynoxy having 2 to 10 carbon atoms; one or more -CH2- in X are unsubstituted or substituted by L', where L' is selected from -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -OC(O)O-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O-, -OCH2-, -CH=CH-, and -C≡C-; one or more H in L' are unsubstituted or substituted by F, Cl, Br, and I.

[0044] m and y are any integers from 1 to 8.

[0045] It should be noted that, The single bond to the left of the O atom at the top is a linking bond, used to connect with other groups.

[0046] Understandably, P represents a polymerizable group; when there are multiple Sp groups in the compounds represented by Formula I and Formula II, the multiple Sp groups can be the same or different; when there are multiple R groups in the same group, the multiple R groups can be the same or different; when there are multiple R' groups in the same group, the multiple R' groups can be the same or different; when n is selected from any integer from 2 to 5, multiple A groups can be the same or different, and multiple Z groups can be the same or different; Q is defined as a P group or a hydrogen atom, that is, the compound represented by Formula I can be a compound with multiple polymerizable functional groups or a compound with a single polymerizable functional group; when m is selected from any integer from 2 to 8, multiple X groups can be the same or different; when y is selected from any integer from 2 to 8, multiple Sp-P groups can be the same or different.

[0047] In some embodiments, the liquid crystal composition is applied to a random polarization depolarization functional layer, that is, the random polarization depolarization functional layer is prepared using the liquid crystal composition.

[0048] In some embodiments, A and B are each independently selected from five-membered ring groups, six-membered ring groups, seven-membered ring groups, or groups formed by the condensation of these ring groups.

[0049] In one specific embodiment, A and B are each independently selected from any one or more combinations of benzofuran group, benzocyclopropene group, indole group, benzothiophene group, indene group, fluorene group and benzocyclobutene group, and one or more H in A and B are not substituted or are substituted by said L.

[0050] In some embodiments, the first liquid crystal compound is selected from any one of the compounds represented by formulas I-1 to I-51:

[0051]

[0052]

[0053]

[0054]

[0055] In some embodiments, Sp is selected from alkylene groups having 1 to 10 carbon atoms, and the methylene group in Sp connected to A is not substituted or is substituted by any combination of one or more of -CO-, -C(O)O-, -OC(O)- and -OC(O)O-.

[0056] In a preferred embodiment, Sp is selected from alkylene groups having 1 to 5 carbon atoms, and the methylene group in Sp connected to A is not substituted or is substituted by any combination of one or more of -CO-, -C(O)O-, -OC(O)- and -OC(O)O-.

[0057] In one specific embodiment, Sp is selected from any one or a combination of the following groups:

[0058]

[0059] In this context, * indicates a connection site.

[0060] In one specific embodiment, the first liquid crystal compound is selected from any one of the following four compounds:

[0061]

[0062] This application also provides a method for synthesizing the first liquid crystal compound shown in Formula I. Taking the method for synthesizing the compound shown in Formula I-7-1 as an example, the synthesis route is shown in synthesis route (1):

[0063]

[0064]

[0065] The mass spectrometry result of the product prepared by the above synthetic route (1) is [M+H]. + :843.3.

[0066] Understandably, all first liquid crystal compounds can be prepared using the above synthetic route (1), with only slight differences in the reactants.

[0067] Specifically, the compound represented by formula I-16-1 was prepared using the above synthetic route (1), and the mass spectrometry result of the prepared product was [M+H]. + :871.3.

[0068] Specifically, the compound represented by formula I-50-1 was prepared using the above-described synthetic route (1), and the mass spectrometry result of the prepared product was [M+H]. + :589.2.

[0069] Specifically, the compound represented by formula I-51-1 was prepared using the above synthetic route (1), and the mass spectrometry result of the prepared product was [M+H]. + :963.3.

[0070] In some embodiments, the second liquid crystal compound is selected from any one of the compounds represented by formulas II-1 to II-6:

[0071]

[0072] Where a is any integer from 0 to 8, and b, c and d are any integers from 2 to 8.

[0073] In some embodiments, the second liquid crystal compound is selected from any one of the compounds represented by formulas II-1-1 to II-6-2:

[0074]

[0075] In one specific embodiment, the second liquid crystal compound is selected from at least one of the following compounds:

[0076]

[0077] This application also provides a method for synthesizing the second liquid crystal compound represented by Formula II. Taking the synthesis method of the compound represented by Formula II-1-3-1 as an example, its synthesis route is shown in synthesis route (2):

[0078]

[0079] The mass spectrometry result of the product prepared by the above synthetic route (2) is [M+H]. +:486.28.

[0080] Understandably, all second liquid crystal compounds can be prepared using the above synthetic route (2), with only slight differences in the reactants.

[0081] Specifically, the compound represented by formula II-1-4-1 was prepared using the above-described synthetic route (2), and the mass spectrometry result of the prepared product was [M+H]. + :457.2.

[0082] Specifically, the compound represented by formula II-1-5-1 was prepared using the above-described synthetic route (2), and the mass spectrometry result of the prepared product was [M+H]. + :485.3.

[0083] Specifically, the compound represented by formula II-2-1-1 was prepared using the above-described synthetic route (2), and the mass spectrometry result of the prepared product was [M+H]. + :455.2.

[0084] Specifically, the compound represented by formula II-5-3-1 was prepared using the above synthetic route (2), and the mass spectrometry result of the prepared product was [M+H]. + :497.3.

[0085] In some embodiments, the mass fraction of the polymeric liquid crystal material in the liquid crystal composition is 50% to 100% of the solid content of the liquid crystal composition. By controlling the mass fraction of the polymeric liquid crystal material within this range, the temperature range for orientation of the liquid crystal composition can be expanded during the preparation of the random polarization depolarization functional layer, or the photocuring effect of the random polarization depolarization functional layer can be improved, thereby reducing the difficulty of preparing the random polarization depolarization functional layer and improving the film formation yield.

[0086] In a preferred embodiment, the mass fraction of the polymeric liquid crystal material in the liquid crystal composition is 58% to 98% of the solid content of the liquid crystal composition.

[0087] For example, in the liquid crystal composition, the mass fraction of the polymeric liquid crystal material is 50%, 52%, 55%, 58%, 60%, 62%, 65%, 68%, 70%, 72%, 75%, 78%, 80%, 82%, 85%, 88%, 90%, 92%, 95%, 98%, or 100% of the solid content of the liquid crystal composition.

[0088] In some embodiments, the liquid crystal composition further includes a solvent, such that the liquid crystal composition is preferably in a liquid state when forming the random depolarization functional layer.

[0089] It should be noted that the solid content of a liquid crystal composition refers to the total mass fraction of the components other than the solvent in the liquid crystal composition.

[0090] In some embodiments, the solvent is preferably an organic solvent, such as a solvent selected from ketones, haloalkanes, amides, sulfoxides, heterocyclic compounds, hydrocarbons, esters, or ethers, with ketones being the most preferred. One of the solvents listed above may be used alone, or two or more may be used simultaneously.

[0091] In some embodiments, the liquid crystal composition further includes at least one of a surfactant, a chiral compound, a polymerization initiator, and a crosslinking agent.

[0092] In some embodiments, the liquid crystal composition further includes a surfactant, and the surfactant is selected from at least one of silicone-based surfactants and fluorinated surfactants. In a preferred embodiment, the surfactant is selected from fluorinated surfactants.

[0093] Understandably, surfactants can be used alone or in combination.

[0094] In some embodiments, the surfactant in the liquid crystal composition is present in a mass fraction of 0.01% to 20% of the total mass fraction of the polymeric liquid crystal compound.

[0095] In a preferred embodiment, the surfactant in the liquid crystal composition is 0.01% to 2% of the total mass fraction of the polymeric liquid crystal compound.

[0096] For example, in the liquid crystal composition, the mass fraction of the surfactant is 0.01%, 0.05%, 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, or 20% of the total mass fraction of the polymerizable liquid crystal compound.

[0097] In some embodiments, to achieve better liquid crystal molecule arrangement, thereby achieving better random depolarization and reducing color shift, a chiral compound (chiral agent) may be added to the liquid crystal composition. The chiral compound has the function of inducing a helical structure in the liquid crystal phase. The chiral compound may be selected from common chiral agents such as isosorbide and isomannitol derivatives.

[0098] In some embodiments, the chiral compound may contain polymerizable groups. When both the chiral compound and the liquid crystal compound contain polymerizable groups, a polymer having repeating units derived from the polymeric liquid crystal material and repeating units derived from the chiral compound can be formed through a polymerization reaction between the chiral compound and the polymeric liquid crystal material. In this manner, the polymerizable groups contained in the chiral compound are preferably the same as those contained in the polymeric liquid crystal material. Therefore, the polymerizable groups of the chiral compound are preferably unsaturated olefinic polymerizable groups, such as the aforementioned P groups.

[0099] In some embodiments, the chiral compound may also be a liquid crystal compound.

[0100] In some embodiments, the chiral compound in the liquid crystal composition is 0.01% to 40% of the mass fraction of the polymeric liquid crystal material.

[0101] In a preferred embodiment, the chiral compound in the liquid crystal composition has a mass fraction of 0.01% to 20% of the mass fraction of the polymeric liquid crystal material.

[0102] For example, in the liquid crystal composition, the mass fraction of the chiral compound is 0.01%, 0.05%, 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, or 40% of the mass fraction of the polymeric liquid crystal material.

[0103] In some embodiments, the liquid crystal composition further includes a polymerization initiator. In the case of polymerization via ultraviolet irradiation, the polymerization initiator is preferably a photopolymerization initiator that can initiate polymerization via ultraviolet irradiation, such as α-carbonyl compounds, azobin ethers, α-hydrocarbon-substituted aromatic azobin compounds, polynuclear quinone compounds, and oxadiazole compounds.

[0104] In some embodiments, the mass fraction of the polymerization initiator in the liquid crystal composition is 0.1% to 20% of the mass fraction of the polymeric liquid crystal material.

[0105] In a preferred embodiment, the mass fraction of the polymerization initiator in the liquid crystal composition is 0.5% to 12% of the mass fraction of the polymeric liquid crystal material.

[0106] For example, in the liquid crystal composition, the mass fraction of the polymerization initiator is 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, or 20% of the mass fraction of the polymerizable liquid crystal material.

[0107] In some embodiments, the liquid crystal composition may optionally contain a crosslinking agent to improve the strength and durability of the cured random depolarization functional layer. Preferably, the crosslinking agent is a crosslinking agent that is cured by ultraviolet light, heat, or moisture.

[0108] The crosslinking agent is selected from epoxy compounds such as (meth)acrylate and ethylene glycol diglycidyl ether, and isocyanate compounds such as hexamethylene diisocyanate and biuret isocyanate.

[0109] In some embodiments, a known catalyst can be added to the liquid crystal composition according to the reactivity of the crosslinking agent, which can improve the film strength and durability of the random depolarization functional layer, as well as increase productivity. Both the crosslinking agent and the catalyst can be used alone or in combination.

[0110] In some embodiments, the crosslinking agent in the liquid crystal composition has a mass fraction of 1% to 40% of the solid content of the liquid crystal composition.

[0111] In a preferred embodiment, the crosslinking agent in the liquid crystal composition has a mass fraction of 3% to 18% of the solid content of the liquid crystal composition.

[0112] For example, in the liquid crystal composition, the mass fraction of the crosslinking agent is 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, or 40% of the solid content of the liquid crystal composition.

[0113] In some embodiments, the liquid crystal composition further includes at least one of polymerization inhibitors, antioxidants, ultraviolet absorbers, light stabilizers, colorants, and metal oxide particles.

[0114] In some embodiments, the liquid crystal composition comprises the aforementioned polymerizable liquid crystal material, additives, and solvent, wherein the additives are selected from at least one of surfactants, chiral compounds, polymerization initiators, crosslinking agents, polymerization inhibitors, antioxidants, ultraviolet absorbers, light stabilizers, colorants, and metal oxide particles. In this case, the solid content of the liquid crystal composition is the total mass fraction of the polymerizable liquid crystal material and the additives.

[0115] Of course, in other embodiments, the liquid crystal composition may consist of the aforementioned polymerizable liquid crystal material, other liquid crystal compounds, additives, and solvents, wherein the additives are selected from at least one of surfactants, chiral compounds, polymerization initiators, crosslinking agents, polymerization inhibitors, antioxidants, ultraviolet absorbers, light stabilizers, colorants, and metal oxide particles. In this case, the solid content of the liquid crystal composition is the total mass fraction of the polymerizable liquid crystal material, other liquid crystal compounds, and additives.

[0116] In some embodiments, the liquid crystal composition is used to fabricate a random depolarization functional layer, in which linearly polarized light incident on the random depolarization functional layer is at least partially converted into circularly polarized light and / or elliptically polarized light, thereby achieving depolarization or even random depolarization effect. When the random depolarization functional layer is applied in a display device, an eye-protection display function can be achieved.

[0117] In some embodiments, the liquid crystal composition is prepared by a thermal dissolution method, and the preparation method of the liquid crystal composition includes the following steps:

[0118] Weigh and mix the first liquid crystal compound represented by Formula I and / or the second liquid crystal compound represented by Formula II according to a preset mass percentage using a balance;

[0119] A mixture of a first liquid crystal compound and / or a second liquid crystal compound is heated and stirred at a temperature of 60℃-100℃ to ensure complete dissolution and mixing; and

[0120] The above liquid crystal mixture was cooled to room temperature and then encapsulated to obtain the target liquid crystal composition.

[0121] It should be noted that when weighing multiple liquid crystal compounds, there is no specific requirement for the order in which they are added. Usually, they are weighed and mixed in order of increasing melting point.

[0122] It is understood that when the liquid crystal composition contains the aforementioned additives and solvents, the additives and solvents may be added before or after the addition of the first liquid crystal compound and / or the second liquid crystal compound. The embodiments of this application do not limit the order of addition.

[0123] It should be noted that other components of the liquid crystal composition provided in the embodiments of this application can be added by those skilled in the art based on their professional knowledge and device parameter requirements.

[0124] In this embodiment, the liquid crystal composition includes a polymerizable liquid crystal material, and the polymerizable liquid crystal material includes at least one first liquid crystal compound of Formula I and / or at least one second liquid crystal compound of Formula II. Since both the first liquid crystal compound of Formula I and the second liquid crystal compound of Formula II have birefringence, the random polarization depolarization functional layer prepared using the first liquid crystal compound of Formula I and / or the second liquid crystal compound of Formula II can randomly convert linearly polarized light incident on the random polarization depolarization functional layer into circularly polarized light and / or elliptically polarized light, thereby enabling the display device using this random polarization depolarization functional layer to achieve eye-friendly display. Furthermore, since both the first liquid crystal compound of Formula I and the second liquid crystal compound of Formula II contain polymerizable groups P, the process of preparing the random polarization depolarization functional layer using polymerizable liquid crystal materials is simple, low-cost, and has a high yield. Therefore, this application can achieve the random polarization depolarization effect through a simpler, lower-cost, and higher-yield method, thereby achieving an eye-protecting effect.

[0125] like Figure 1 As shown, this application embodiment also provides an optical film 1, which includes a substrate layer 2 and a random polarization depolarization functional layer 3 disposed on one side of the substrate layer 2. Linearly polarized light incident on the optical film 1 passes through the random polarization depolarization functional layer 3, and at least a portion of the linearly polarized light is converted into circularly polarized light and / or elliptically polarized light. The material of the random polarization depolarization functional layer 3 includes a polymer of the polymeric liquid crystal material in the liquid crystal composition of the aforementioned embodiments, or the random polarization depolarization functional layer 3 is made using the liquid crystal composition of the aforementioned embodiments.

[0126] Understandably, the substrate layer 2 serves to support the random polarization correction layer 3. The substrate layer 2 can be a sheet, such as a film or a plate.

[0127] In some embodiments, the light transmittance of the substrate layer 2 is greater than or equal to 50%. In a preferred embodiment, the light transmittance of the substrate layer 2 is greater than or equal to 70%. In a more preferred embodiment, the light transmittance of the substrate layer 2 is greater than or equal to 85%. It is understood that the higher the light transmittance of the substrate layer 2, the better, as it helps to reduce light loss.

[0128] In some embodiments, the thickness of the substrate layer 2 ranges from 1 micrometer to 1000 micrometers. In a preferred embodiment, the thickness of the substrate layer 2 ranges from 3 micrometers to 250 micrometers. In a more preferred embodiment, the thickness of the substrate layer 2 ranges from 5 micrometers to 150 micrometers.

[0129] Understandably, the thickness of the random polarization depolarization functional layer 3 can be appropriately set according to the actual use and the forming material of the substrate layer 2 to maintain the required thickness.

[0130] Specifically, the substrate layer 2 can be a single-layer structure or a multi-layer structure.

[0131] In some embodiments, the substrate layer 2 is a single-layer structure, and the material of the substrate layer 2 is selected from at least one of glass, poly(methyl methacrylate) (PPMA), polyethylene terephthalate (PET), polycarbonate (PC), triacetylcellulose (TAC), cyclic olefin polymer (COP), cyclic olefin copolymer (COC), and polyvinyl chloride (PVC).

[0132] In some embodiments, the substrate layer 2 has a multilayer structure, and the material of each layer is selected from at least one of glass, PMMA, PET, PC, TAC, COP, COC and PVC.

[0133] In some embodiments, the substrate layer 2 may be surface treated, and the surface treatment methods include friction treatment, stretching, laser beam, ion bombardment, etc., to achieve a preset liquid crystal molecule orientation effect.

[0134] In the random depolarization functional layer 3, the molecules of the polymeric liquid crystal material can be oriented in an ordered manner or in a disordered, completely random manner.

[0135] Specifically, polymeric liquid crystal materials can possess an optical axis, which refers to the axis with the highest refractive index in the polymeric liquid crystal material. For example, when the polymeric liquid crystal material is a rod-shaped liquid crystal compound, the optical axis is along the long axis of the rod shape; when the polymeric liquid crystal material is a disk-shaped liquid crystal compound, the optical axis is along a direction orthogonal to the disk surface. The angle of the optical axis is preferably 0°-90°, and more preferably 0°-45°. When the molecules of the polymeric liquid crystal material are completely disordered and randomly oriented, the polymeric liquid crystal material may not have an optical axis, and its refractive index at all angles is equivalent, thereby achieving random depolarization.

[0136] In some embodiments, the thickness of the random depolarization functional layer 3 ranges from 1 micrometer to 40 micrometers. For example, the thickness of the random depolarization functional layer 3 is 1 micrometer, 3 micrometer, 5 micrometer, 7 micrometer, 10 micrometer, 12 micrometer, 15 micrometer, 18 micrometer, 20 micrometer, 22 micrometer, 25 micrometer, 28 micrometer, 30 micrometer, 32 micrometer, 35 micrometer, 38 micrometer or 40 micrometer.

[0137] In some embodiments, the refractive index of the random depolarization functional layer 3 satisfies the following relationship: 1.5 ≤ n x ≤2.0, 1.3≤n y ≤1.8, and n x -n y ≥0.002; where n x n represents the refractive index of the random depolarization functional layer 3 on the slow axis. y This represents the refractive index of the random depolarization functional layer 3 along the fast axis. In other words, the liquid crystal in the random depolarization functional layer 3 provided in this embodiment exhibits birefringence, resulting in a phase difference in the random depolarization functional layer 3. This facilitates the change of the polarization state of light, thereby achieving a random depolarization effect. Furthermore, the random depolarization functional layer 3 in this embodiment possesses optical anisotropy, enabling the achievement of a random depolarization effect.

[0138] In some embodiments, the in-plane retardation of the random depolarization functional layer 3 ranges from 20 nanometers to 10,000 nanometers within the visible light wavelength range.

[0139] Specifically, the in-plane retardation of the random depolarization functional layer 3 is R0(λ) = Re(λ) = Δn(λ) × d, where λ represents the wavelength of the incident light, Δn(λ) represents the difference in refractive index between the fast and slow axes of the random depolarization functional layer 3, and d represents the thickness of the random depolarization functional layer 3. Both λ and d are in nanometers (nm).

[0140] The in-plane retardation is calculated by multiplying the refractive index difference of the random depolarization functional layer 3 by its thickness. The refractive index difference associated with the anisotropy of the random depolarization functional layer 3 is defined as the difference between the refractive index along the slow axis in the plane passing through a predetermined region and the refractive index in a direction orthogonal to the slow axis. That is, the refractive index difference Δn(λ) associated with the anisotropy of the random depolarization functional layer 3 is equal to the difference between the refractive index of the polymeric liquid crystal material along the optical axis and the refractive index of the polymeric liquid crystal material in the plane perpendicular to the optical axis. In other words, the aforementioned refractive index difference Δn(λ) is equal to the refractive index difference of the liquid crystal compound divided by its birefringence.

[0141] When λ = 550nm, the in-plane delay of random depolarization functional layer 3 is Re(550) = Δn(550) × d, and 20nm ≤ Δn(550) × d ≤ 10000nm.

[0142] In a preferred embodiment, 250nm ≤ Δn(550)×d ≤ 9000nm.

[0143] It should be noted that, within the visible light wavelength range, the range of in-plane retardation of the random depolarization functional layer 3 is the same as that of the in-plane retardation when λ = 550 nm, and can be adjusted appropriately.

[0144] Understandably, when linearly polarized light is incident on the random depolarization functional layer 3 with the aforementioned in-plane delay, the light is refracted, and the polarization state of the linearly polarized light is changed / cancelled, thereby achieving the random depolarization effect.

[0145] In some embodiments, the process of preparing the optical film includes the following steps:

[0146] A liquid crystal composition is coated on the substrate layer 2; the coating method includes, but is not limited to, bar coating, roller coating, doctor blade coating, spin coating, wire-wound bar coating, extrusion coating, suspension coating, gravure coating, spray coating, mold coating or inkjet coating;

[0147] The liquid crystal composition coated on substrate layer 2 is subjected to a drying process; the drying process includes natural drying at room temperature, heating, or air drying; and

[0148] The dried liquid crystal composition is cured to obtain a random depolarization functional layer 3; the curing method includes thermal curing or photocuring.

[0149] Specifically, between coating liquid crystal compositions, the surface of the substrate layer 2 to be coated can be subjected to surface treatments such as friction, stretching, laser beam or ion bombardment, which is beneficial to the orientation of liquid crystal molecules in the random depolarization functional layer 3 formed later.

[0150] Specifically, the purpose of the drying process is to remove solvents and other components from the coating layer. For ease of preparation, heating and curing on a hot plate is preferred, with a heating temperature preferably between 10°C and 250°C, more preferably between 25°C and 180°C. Furthermore, the heating time is preferably between 1 second and 300 seconds, more preferably between 1 second and 60 seconds.

[0151] Specifically, the curing process is carried out by heating and / or light irradiation (exposure), preferably photopolymerization. The light source used for curing includes infrared, visible, or ultraviolet light, preferably ultraviolet light. Furthermore, ultraviolet light can be irradiated while heating occurs during curing, or ultraviolet light can be irradiated through a filter that transmits only a specific wavelength. The irradiation energy is preferably 50 mJ / cm². 2 ~1500mJ / cm 2 The wavelength of the ultraviolet light irradiated is preferably 250nm to 430nm.

[0152] In addition, the curing process of the random depolarization functional layer 3 is a free radical polymerization reaction process. In order to reduce the polymerization inhibition caused by oxygen, it is preferable to expose it under a nitrogen atmosphere.

[0153] Specifically, the thickness of the coating obtained by coating the above-mentioned liquid crystal composition is preferably 0.1 micrometers to 20 micrometers or more, more preferably 0.5 micrometers to 15 micrometers, and even more preferably 1.0 micrometers to 15 micrometers.

[0154] In this embodiment, the random depolarization functional layer 3 in the optical film 1 is prepared using the liquid crystal composition described in the previous embodiment. The preparation process is simple, easy to implement, low in cost, and has a high yield. Furthermore, since the liquid crystal composition contains a polymeric liquid crystal material composed of at least one first liquid crystal compound of Formula I and / or at least one second liquid crystal compound of Formula II, this polymeric liquid crystal material has birefringence and a suitable in-plane retardation, enabling the prepared random depolarization functional layer 3 to randomly convert incident linearly polarized light into circularly polarized light and / or elliptically polarized light. This allows the display device 12 with the random depolarization functional layer 3 to achieve eye-friendly display. Therefore, this embodiment can achieve random depolarization effect through a simpler, lower-cost, and higher-yield method, thereby providing an eye-protecting effect.

[0155] It is understandable that using the liquid crystal composition provided in the embodiments of this application to fabricate the random depolarization functional layer 3 has the characteristics of reducing the number of process steps and saving production capacity, which is of positive significance for the development of green manufacturing processes and is very suitable for the formulation of mixed liquid crystals.

[0156] like Figure 2 As shown, this application embodiment also provides an optical film, which is compatible with... Figure 1 The optical film shown is different in that the optical film 1 also includes an alignment layer 4 located between the substrate layer 2 and the random depolarization functional layer 3. The alignment layer 4 is configured to deflect the molecules of the polymeric liquid crystal material to a preset direction when the random depolarization functional layer 3 is formed.

[0157] In some embodiments, when forming the random depolarization functional layer 3, the alignment layer 4 is used to align the polymeric liquid crystal material molecules into a predetermined liquid crystal alignment pattern. In this process, the liquid crystal molecules can be ordered or disordered, preferably disordered.

[0158] It should be noted that, in order to achieve random depolarization, the liquid crystal in the random depolarization functional layer 3 is microscopically ordered but macroscopically disordered. Specifically, within a sufficiently small microscopic region, the liquid crystal molecules are arranged in an ordered manner, resulting in a retardation amount within that microscopic region, thereby altering the polarization state of light transmitted through that unit. Within the macroscopic structure, the liquid crystal of the entire film layer is disordered, resulting in multiple microscopic regions having multiple different retardation amounts. This allows for varying degrees of alteration of the polarization state of linearly polarized light, achieving depolarization or even random depolarization.

[0159] Understandably, if directly coating the liquid crystal composition onto the substrate layer 2 to form a film (i.e., the random depolarization functional layer 3) can achieve the above-mentioned microscopically ordered but macroscopically disordered liquid crystal distribution state, that is, to achieve a random depolarization effect (sufficiently low polarization degree), then there is no need to place an alignment film between the substrate layer 2 and the random depolarization functional layer 3. If the polarization degree of the film formed by directly coating the liquid crystal composition onto the substrate layer 2 is not low enough, then an alignment layer 4 can be formed on the substrate layer 2 first, followed by the random depolarization functional layer 3. The alignment layer 4 can be used to regulate the orderliness of the microscopically ordered liquid crystal. The specific decision on whether to place the alignment layer 4 requires comprehensive consideration of various factors, including the material type of the substrate layer 2, the surface treatment of the substrate layer 2, the structural formula of the polymerizable liquid crystal material, and the coating process.

[0160] In some embodiments, the material of the orientation layer 4 is selected from azo compounds, aromatic ester compounds, maleimides having photo-orientation units and / or alkenyl-substituted nadicimide compounds, photo-crosslinked silane derivatives, photo-crosslinked polyimides, photo-crosslinked polyamides and photo-crosslinked esters, and photodimerizable compounds, especially cinnamic acid ester compounds, chalcone compounds and coumarin compounds as preferred examples.

[0161] In a preferred embodiment, the material of the orientation layer 4 is selected from at least one of azo compounds, photocrosslinked polyimides, photocrosslinked polyamides, photocrosslinked polyesters, cinnamic acid ester compounds, and chalcone compounds.

[0162] It should be noted that the method of forming the alignment layer 4 is not limited in the embodiments of this application. One exemplary method is to form an alignment pattern by coating a composition containing a specified photoalignment material on the surface of the substrate layer 2 and drying it, and then exposing the resulting coating film (the precursor of the photoalignment layer 4) with a laser beam to form the alignment layer 4.

[0163] In some embodiments, the process of preparing the optical film includes the following steps:

[0164] An orientation material is coated on substrate layer 2;

[0165] The orientation material coated on the substrate layer 2 is dried.

[0166] The dried orientation material is cured to obtain orientation layer 4;

[0167] A liquid crystal composition is coated on the alignment layer 4;

[0168] The liquid crystal composition coated on the alignment layer 4 is dried; and

[0169] The dried liquid crystal composition was cured to obtain a random depolarization functional layer 3.

[0170] It should be noted that the coating method, drying method and curing method used in preparing the orientation layer 4 can be the same as the coating method, drying method and curing method used in preparing the random polarization depolarization functional layer 3. For details, please refer to the description of the foregoing embodiments, which will not be repeated here.

[0171] In this embodiment, by setting an alignment layer 4 between the substrate layer 2 and the random depolarization functional layer 3, the orientation of liquid crystal molecules can be controlled by the alignment layer 4 during the formation of the random depolarization functional layer 3, so that the liquid crystal as a whole is distributed in a state of microscopic order and macroscopic disorder, thereby enabling the random depolarization functional layer 3 to have a random depolarization function.

[0172] This application also provides Examples 1-6 and Comparative Examples 1-3 to verify the depolarization performance of the optical films provided in this application.

[0173] The structural composition and optical performance parameters (degree of polarization) of the optical films provided in Examples 1-6 and Comparative Examples 1-3 are shown in Table 1. The structural formula of the polymeric liquid crystal material in the liquid crystal composition used to prepare the random depolarization functional layer of the optical films provided in Examples 1-6 is shown in Table 2.

[0174] It should be noted that Δn in Table 1 represents the optical anisotropy at 25℃. The degree of polarization (DOP) is used to evaluate the depolarization level, and the formula for calculating DOP is as follows:

[0175] DOP=(Lmax-Lmin) / (Lmax+Lmin);

[0176] Where Lmax and Lmin represent the maximum and minimum light intensity, respectively.

[0177] The optical performance testing process for the optical film is as follows: The backlight, lower polarizer, optical film, and upper polarizer are set up in sequence from bottom to top, and the relative positions of the backlight, lower polarizer, and optical film are kept fixed; the upper polarizer is rotated from 0° to 180°, and the brightness change value is tested through the detector above the upper polarizer, and the maximum and minimum light intensities are recorded.

[0178] The value of DOP ranges from 0 (natural light) to 1 (fully polarized light). Obviously, the smaller the DOP, the better the depolarization effect.

[0179] Table 1

[0180]

[0181] As shown in Table 1, Examples 1, 3, and 5 provide... Figure 1The optical films shown all have a thickness of 6 micrometers for the random depolarization functional layers within them; Examples 2, 4, and 6 provide... Figure 2 The optical films shown all have a random depolarization functional layer thickness of 5 micrometers. Furthermore, the substrate layer material in Examples 1 and 2 is glass, the substrate layer material in Examples 3 and 4 is PET, and the substrate layer material in Examples 5 and 6 is PMMA. The surface of the substrate layer in Examples 3 and 5 underwent random rubbing treatment, while the surface of the substrate layer in the other examples was not treated. The Δn of the random depolarization functional layer in Examples 1 to 6 is different. The optical films provided in Comparative Examples 1 to 3 contain only a substrate layer, and the substrate layer materials are glass, PET, and PMMA, respectively.

[0182] As shown in Table 2, the polymeric liquid crystal materials used to form the random depolarization functional layers of Examples 1 to 6 are all different. In Examples 1 and 3-6, the polymeric liquid crystal materials are all composed of a first liquid crystal compound shown in Formula I and a second liquid crystal compound shown in Formula II. In Example 2, the polymeric liquid crystal material is composed only of the first liquid crystal compound shown in Formula I. Furthermore, the first liquid crystal compounds in Examples 2, 3, and 6 have the same structural formula, and the second liquid crystal compounds in Examples 1 and 3 have the same structural formula.

[0183] Table 2

[0184]

[0185] Specifically, the polymerizable liquid crystal material of Example 1 is composed of a first liquid crystal compound represented by Formula I-50-1 and a second liquid crystal compound represented by Formula II-1-4-1; the polymerizable liquid crystal material of Example 2 is composed of a first liquid crystal compound represented by Formula I-7-1; the polymerizable liquid crystal material of Example 3 is composed of a first liquid crystal compound represented by Formula I-7-1 and a second liquid crystal compound represented by Formula II-1-4-1; the polymerizable liquid crystal material of Example 4 is composed of a first liquid crystal compound represented by Formula I-16-1 and a second liquid crystal compound represented by Formula II-5-3-1; the polymerizable liquid crystal material of Example 5 is composed of a first liquid crystal compound represented by Formula I-51-1 and a second liquid crystal compound represented by Formula II-2-1-1; and the polymerizable liquid crystal material of Example 6 is composed of a first liquid crystal compound represented by Formula I-7-1 and a second liquid crystal compound represented by Formula II-1-5-1.

[0186] It should be noted that the content in Table 2 refers to the percentage of the mass fraction of the polymeric liquid crystal material to the solid content of the liquid crystal composition. When the polymeric liquid crystal material is composed of the first liquid crystal compound shown in Formula I and the second liquid crystal compound shown in Formula II, the two content values ​​in the same row of Table 2 represent the contents of the corresponding first liquid crystal compound and the second liquid crystal compound, respectively, in the order of their appearance.

[0187] It is understandable that the additives and solvents used in the liquid crystal compositions corresponding to Examples 1 to 6 are the same, except for the polymeric liquid crystal material.

[0188] As shown in Table 1, the DOP of the three untreated pure substrate layers in Comparative Examples 1-3 is close to 1, indicating that the glass, PET, and PMMA substrate layers have almost no depolarization effect. When applied to display devices, the light emitted from the upper polarizer is almost entirely linearly polarized. In contrast, Examples 1-6, by treating the three substrate layers of Comparative Examples 1-3 with surface treatment or applying an alignment layer, and by combining random depolarization functional layers of different thicknesses and Δn, resulted in six optical films with a polarization degree below 29%, with the best reaching 8.9%. This demonstrates that the optical films provided in the embodiments of this application can achieve a good random depolarization effect.

[0189] like Figure 3 As shown, this application embodiment also provides a polarizer 5, which includes a polarizing functional layer 6 and an optical film 1 from the aforementioned embodiment. The optical film 1 is disposed on one side of the polarizing functional layer 6.

[0190] In some embodiments, the polarizing functional layer 6 has an incident light side and an exit light side disposed opposite to each other, and the optical film 1 is disposed on the exit light side of the polarizing functional layer 6.

[0191] In some embodiments, the polarizing functional layer 6 includes a first adhesive layer 7, a polarizing layer 8, and a second adhesive layer 9, with the first adhesive layer 7 and the second adhesive layer 9 located on opposite sides of the polarizing layer 8; the optical film 1 is located on the side of the second adhesive layer 9 facing away from the polarizing layer 8. Specifically, the substrate layer 2 of the optical film 1 is located between the second adhesive layer 9 and the random depolarization functional layer 3. That is, the substrate layer 2 of the optical film 1 is directly connected to the polarizing layer 8 through the second adhesive layer 9. This design allows the optical film 1 to be integrated into the polarizer 5, which helps to save one substrate layer 2.

[0192] Of course, in other embodiments, the polarizer 5 also includes another substrate layer (not shown in the figure) located between the polarizing functional layer 6 and the optical film 1, and the substrate layer 2 in the optical film 1 is connected to the other substrate layer by another adhesive layer. That is, the optical film 1 can be bonded to a conventional polarizing structure by an adhesive layer.

[0193] In some embodiments, the material of the polarizing layer 8 is selected from polyvinyl alcohol (PVA), but is not limited thereto.

[0194] In some embodiments, the materials of the first adhesive layer 7 and the second adhesive layer 9 are selected from pressure-sensitive adhesives, but are not limited thereto.

[0195] In some embodiments, such as Figure 4 As shown, the polarizing functional layer 6 also includes a compensation layer 10 located between the first adhesive layer 7 and the polarizing layer 8. The compensation layer 10 can be a phase compensation layer or a viewing angle compensation layer, but is not limited to these.

[0196] In some embodiments, the polarizer 5 further includes a release film 11 disposed on the side of the polarizing functional layer 6 opposite to the optical film 1. When the polarizer 5 is applied to the display device 12, the release film 11 is removed.

[0197] In some embodiments, the polarizer 5 can be applied not only to the display device 12, but also to products such as sunglasses. Sunglasses containing the random anti-polarization functional layer 3 will not cause black screen or iridescent problems when wearing and viewing images, which is beneficial to improving the user experience.

[0198] In this embodiment, since the light-emitting side of the polarization functional layer 6 of the polarizer 5 is provided with the optical film 1 of the aforementioned embodiment, the linearly polarized light emitted from the polarization functional layer 6 can be randomly converted into circularly polarized light and / or elliptically polarized light when it passes through the random depolarization functional layer 3 of the optical film 1. This makes the light emitted by the display device 12 using the polarizer 5 similar to natural light, thereby achieving a healthy and eye-protecting display.

[0199] like Figure 5 As shown, this application embodiment also provides a display device 12, which includes a display panel 13 and an optical film 1 of the aforementioned embodiment, the optical film 1 being disposed on the light-emitting side of the display panel 13; or, the display device 12 includes a display panel 13 and a polarizer 5 of the aforementioned embodiment, the polarizer 5 being disposed on the light-emitting side of the display panel 13, and the optical film 1 being disposed on the side of the polarization functional layer 6 facing away from the display panel 13.

[0200] In some embodiments, the display device 12 further includes a lower polarizer 14 and a backlight module 15 disposed on the back of the display panel 13, with the lower polarizer 14 located between the backlight module 15 and the display panel 13. In this case, the display panel 13 can be a liquid crystal display panel 13, but is not limited thereto.

[0201] It is understandable that the optical film 1 of the aforementioned embodiment is not required in the lower polarizer 14.

[0202] Of course, the display panel 13 described in the embodiments of this application can also be an active display panel. It is understood that any display panel that can generate linearly polarized light is within the scope of protection of this application.

[0203] In this embodiment, since the light-emitting side of the display device 12 is provided with an optical film 1 having a random polarization depolarization function, the light emitted by the display device 12 is similar to natural light, thereby achieving a healthy and eye-protecting display.

[0204] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0205] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0206] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0207] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A liquid crystal composition, characterized in that, The liquid crystal composition comprises a polymerizable liquid crystal material, wherein the polymerizable liquid crystal material comprises at least one first liquid crystal compound of Formula I and / or at least one second liquid crystal compound of Formula II: Wherein, P is selected from Sp is selected from any one or more combinations of single bond, -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O-, -OCH2-, alkylene group having 1 to 10 carbon atoms, alkenyl group having 2 to 10 carbon atoms, and alkynyl group having 2 to 10 carbon atoms. In Sp, any one or more -CH2- groups are not substituted or are substituted by any one of -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -OC(O)O-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O-, -OCH2-, -CH=CH-, and -C≡C-. In Sp, any one or more H groups are not substituted or are substituted by any one of F, Cl, Br, and I. A and B are selected from substituted or unsubstituted aromatic rings, heteroaromatic rings, aliphatic rings, or fused ring groups. At least one of A and B represents a substituted or unsubstituted 1,4-phenylene. One or more H atoms in A and B are unsubstituted or substituted with L. L is selected from F, Cl, Br, I, CN, NO2, NCO, NCS, OCN, SCN, and any straight-chain or branched alkyl group having 1 to 8 carbon atoms. One or more H atoms in the straight-chain or branched alkyl group having 1 to 8 carbon atoms are unsubstituted or substituted with F or C. l is substituted, wherein the -CH2- in the straight-chain or branched alkyl group having 1 to 8 carbon atoms is unsubstituted or substituted by any one of -O-, -S-, -SO-, -COO-, -OCO-, -CO-S-, -S-CO-, -O-CO-O-, -CO-NR-, -NR-CO-, -CR=CR-, -CR=N-, -N=CR-, -N=N-, -CR=NN=CR- and -C≡C-, and R is selected from H, F or an alkyl group having 1 to 10 carbon atoms; n is any integer from 1 to 5; Z is selected from single bonds, alkylene groups having 1 to 10 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, alkynyl groups having 2 to 10 carbon atoms, -O-, -S-, -CHR'-, -CHR'CHR'-, -OCHR'-, -CHR'O-, -OCHR'O-, -SO-, -SO2-, -COO-, -OCO-, -CO-S-, -S-CO-, -O-CO-O-, -CO-NR'-, -NR'-CO-, -SCHR'-, -CHR'S-, -SO-CHR'-, -CHR'-SO-, -SO2-CHR'-, -CHR'-SO2-, -CF2O-, -OCF2-, -CF2S-, -SCF2-, -OCHR'CHR'O-, -SCHR'CHR'S -, -SO-CHR'CHR'-SO-, -SO2-CHR'CHR'-SO2-, -CH=CH-COO-, -CH=CH-OCO-, -COO-CH=CH-, -OCO-CH=CH-, -COO-CHR'CHR'-, -OCO-CHR'CHR'-, -CHR'CHR'-COO-, -CHR'CHR'-OCO-, -COO-CHR'-, -OCO-CHR'-, -CHR'-COO-, -CHR'-OCO-, -CR'=CR'-, -CR'=N-, -N=CR'-, -N=N-, -CR'=NN=CR- or -CF=CF-, where R' is selected from H or an alkyl group having 1 to 10 carbon atoms, and any one of the H atoms in Z is unsubstituted or substituted. Replace any one of them; Q is selected from H, X is selected from H, OH, F, Cl, Br, CN, SCN, NCS, alkyl having 1 to 10 carbon atoms, alkoxy having 1 to 10 carbon atoms, alkenyl having 2 to 10 carbon atoms, alkenoxy having 2 to 10 carbon atoms, alkynyl having 2 to 10 carbon atoms, and alkynoxy having 2 to 10 carbon atoms; one or more -CH2- in X are unsubstituted or substituted by L', where L' is selected from -O-, -S-, -CO-, -C(O)O-, -OC(O)-, -OC(O)O-, -CF2O-, -OCF2-, -CH2CH2-, -CH2O-, -OCH2-, -CH=CH-, and -C≡C-; one or more H in L' are unsubstituted or substituted by F, Cl, Br, and I. m and y are any integers from 1 to 8.

2. The liquid crystal composition according to claim 1, characterized in that, A and B are selected from any one or more combinations of benzofuran group, benzocyclopropene group, indole group, benzothiophene group, indene group, fluorene group and benzocyclobutene group, and one or more H in A and B are not substituted or are substituted by said L.

3. The liquid crystal composition according to claim 1, characterized in that, The first liquid crystal compound is selected from any one of the compounds represented by formulas I-1 to I-51:

4. The liquid crystal composition according to any one of claims 1 to 3, characterized in that, Sp is selected from alkylene groups having 1 to 10 carbon atoms, and the methylene group connected to A in Sp is not substituted or is substituted by any combination of one or more of -CO-, -C(O)O-, -OC(O)- and -OC(O)O-.

5. The liquid crystal composition according to any one of claims 1 to 3, characterized in that, Sp is selected from any one or a combination of the following groups: In this context, * indicates a connection site.

6. The liquid crystal composition according to claim 1, characterized in that, The first liquid crystal compound is selected from any one of the following compounds:

7. The liquid crystal composition according to claim 1, characterized in that, The second liquid crystal compound is selected from any one of the compounds represented by formulas II-1 to II-6: Where a is any integer from 0 to 8, and b, c and d are any integers from 2 to 8.

8. The liquid crystal composition according to claim 7, characterized in that, The second liquid crystal compound is selected from any one of the compounds represented by formulas II-1-1 to II-6-2:

9. The liquid crystal composition according to claim 1, characterized in that, The second liquid crystal compound is selected from any one of the following compounds:

10. The liquid crystal composition according to claim 1, characterized in that, In the liquid crystal composition, the mass fraction of the polymeric liquid crystal material is 50% to 100% of the solid content of the liquid crystal composition.

11. The liquid crystal composition according to claim 10, characterized in that, The liquid crystal composition further includes at least one of a surfactant, a chiral compound, a polymerization initiator, and a crosslinking agent.

12. The liquid crystal composition according to claim 11, characterized in that, In the liquid crystal composition, the surfactant has a mass fraction of 0.01% to 20% of the polymeric liquid crystal material, and / or the chiral compound has a mass fraction of 0.01% to 40% of the polymeric liquid crystal material, and / or the polymerization initiator has a mass fraction of 0.1% to 20% of the polymeric liquid crystal material, and / or the crosslinking agent has a mass fraction of 1% to 40% of the solid content of the liquid crystal composition.

13. The liquid crystal composition according to claim 10, characterized in that, The liquid crystal composition further includes at least one of polymerization inhibitors, antioxidants, ultraviolet absorbers, light stabilizers, colorants, and metal oxide particles.

14. An optical film, characterized in that, The optical film includes a substrate layer and a random depolarization functional layer disposed on one side of the substrate layer. Linearly polarized light incident on the optical film passes through the random depolarization functional layer, and at least a portion of the linearly polarized light is converted into circularly polarized light and / or elliptically polarized light. The material of the random polarization depolarization functional layer includes a polymer of the polymeric liquid crystal material in the liquid crystal composition according to any one of claims 1 to 13, or the random polarization depolarization functional layer is made of the liquid crystal composition according to any one of claims 1 to 13.

15. The optical film according to claim 14, characterized in that, The optical film further includes an alignment layer located between the substrate layer and the random depolarization functional layer, the alignment layer being configured to deflect the molecules of the polymeric liquid crystal material to a preset direction when the random depolarization functional layer is formed.

16. The optical film according to claim 14 or 15, characterized in that, The refractive index of the random depolarization functional layer satisfies the following relationship: 1.5 ≤ n x ≤2.0, 1.3≤n y ≤1.8, and n x -n y ≥0.002; Where, n x n represents the refractive index of the random depolarization functional layer on the slow axis. y This represents the refractive index of the random depolarization functional layer in the fast axis direction.

17. The optical film according to claim 14 or 15, characterized in that, Within the visible light wavelength range, the in-plane retardation of the random depolarization functional layer ranges from 20 nanometers to 10,000 nanometers.

18. A polarizer, characterized in that, It includes a polarizing functional layer and an optical film as described in any one of claims 14 to 17, wherein the optical film is disposed on one side of the polarizing functional layer.

19. A display device, characterized in that, The display panel includes an optical film as described in any one of claims 14 to 17, wherein the optical film is disposed on the light-emitting side of the display panel; Alternatively, the display device may include the display panel and the polarizer as described in claim 18, wherein the polarizer is disposed on the light-emitting side of the display panel, and the optical film is disposed on the side of the polarizing functional layer opposite to the display panel.

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