Liquid crystal composition and application thereof

Abstract

The invention belongs to the technical field of liquid crystal, and provides a liquid crystal composition and application thereof, the liquid crystal composition comprises one or more compounds as shown in a formula I, one or more compounds as shown in a formula II and one or more compounds as shown in a formula III; after the liquid crystal composition provided by the invention is combined with a dichroic dye, the liquid crystal composition has a relatively high contrast ratio and has a wide application prospect in the field of high-contrast dye PDLC (Polymer Dispersed Liquid Chromatography); wherein R1 represents an alkyl group with the carbon atom number of 1-10 or an alkoxy group with the carbon atom number of 1-10; r2 and R3 independently represent an alkyl group with the carbon atom number of 1-10; y1 represents a cyano group or an alkyl group having 1-10 carbon atoms; # imgabs0 # representing # imgabs1 # or # imgabs2 #

Description

Technical Field

[0001] The present invention belongs to the technical field of liquid crystals, and relates to a liquid crystal composition and its applications in dichroic dye liquid crystals and dichroic dye PDLCs. Background Art

[0002] Dichroic dyes refer to organic dyes that exhibit different colors due to different light absorption in the long-axis and short-axis directions of the molecule. After this dichroic dye is dissolved in a liquid crystal and mixed with glue, a dye PDLC dimming film of a specific color can be prepared through a polymerization phase separation technique, and it is widely used in fields such as building facades and automotive sunroofs.

[0003] Dichroic dye PDLC is opaque (dark state) when no electric field is applied, and transparent (bright state) when an electric field is applied. The transmittance ratio between the bright state and the dark state is called the contrast ratio, which is one of the important indicators for measuring the performance of dichroic dye PDLC. Currently, in order to improve the contrast ratio of the liquid crystal composition for dichroic dye PDLC (polymer dispersed liquid crystal), the following several technical means are usually adopted: 1. Optimize the liquid crystal material; 2. Optimize the dichroic ratio dye, such as using a high dichroic ratio dye or preparing a multi-layer dye structure; 3. Improve the driving method; 4. Optimize the surface treatment and alignment technology; 5. Optimize the additives; however, the above methods all have certain limitations, high costs, and limited improvement in the contrast ratio.

[0004] Therefore, it is of great significance to develop a liquid crystal composition for dichroic dyes and dichroic dye PDLC. Summary of the Invention

[0005] The present invention provides a liquid crystal composition and its applications, which improve the contrast ratio of dichroic dye PDLC and have broad application prospects in the field of high-contrast dye PDLC.

[0006] The technical solution of the present invention is realized as follows:

[0007] A liquid crystal composition, the liquid crystal composition comprising one or more compounds represented by formula I, one or more compounds represented by formula II, and one or more compounds represented by formula III;

[0008]

[0009] Wherein, R 1 represents an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms; R 2 , R 3 each independently represents an alkyl group having 1 to 10 carbon atoms; Y 1 represents a cyano group or an alkyl group having 1 to 10 carbon atoms; represents

[0010] Preferably, the liquid crystal composition further comprises one or more compounds represented by Formula IV;

[0011]

[0012] wherein R 4 represents an alkyl group having 1 to 10 carbon atoms; Y 1 represents a cyano group or an alkyl group having 1 to 10 carbon atoms;

[0013] represents

[0014] Preferably, the compound represented by Formula I is selected from one or more of the compounds represented by Formula I-1 to Formula I-8:

[0015]

[0016] Preferably, the compound represented by Formula II is selected from one or more of the compounds represented by Formula II-1 to Formula II-3:

[0017] Preferably, the compound represented by Formula III is selected from one or more of the compounds represented by Formula III-1 to Formula III-4:

[0018]

[0019] Preferably, the compound represented by Formula IV is selected from one or more of the compounds represented by Formula IV-1 to Formula IV-5:

[0020] Preferably, the liquid crystal composition comprises the following components in mass percentages: 35 to 60% of the compound represented by Formula I, 10 to 25% of the compound represented by Formula II, 15 to 25% of the compound represented by Formula III, and 0 to 20% of the compound represented by Formula IV;

[0021] Preferably, the liquid crystal composition comprises the following components in mass percentages: 35 to 50% of the compound represented by Formula I, 15 to 20% of the compound represented by Formula II, 17 to 25% of the compound represented by Formula III, and 0 to 20% of the compound represented by Formula IV.

[0022] Preferably, the compound represented by Formula II is a mixture of the compounds represented by II-1 and II-2;

[0023] Preferably, the compound represented by Formula I includes, but is not limited to, the compound represented by I-8.

[0024] Preferably, the compound represented by Formula III is a mixture of the compounds represented by III-1, III-2 and III-4.

[0025] Preferably, the compound represented by Formula IV is a mixture of the compounds represented by IV-1, IV-2, IV-3 and IV-4.

[0026] Preferably, the compound represented by Formula II is the compounds represented by II-1 and II-2 with a mass ratio of 2-4:1.

[0027] Preferably, the compound represented by Formula II is the compounds represented by II-1 and II-2 with a mass ratio of 3:1.

[0028] Preferably, the compound represented by Formula I is a mixture of the compounds represented by I-2, I-4, I-6 and I-8.

[0029] The present invention also provides an application of the liquid crystal composition as described above in a dichroic dye liquid crystal.

[0030] Preferably, the dichroic dye liquid crystal comprises a dichroic dye and the above liquid crystal composition, wherein the dichroic dye accounts for 0.1-10% of the total weight of the dichroic dye liquid crystal.

[0031] Preferably, the dichroic dye accounts for 0.1-0.5% of the total weight of the dichroic dye liquid crystal.

[0032] Preferably, the dichroic dye is an anthraquinone dichroic dye or a benzopyrene dye.

[0033] The present invention also provides an application of the liquid crystal composition as described above in a dichroic dye PDLC; the dichroic dye PDLC comprises a dichroic dye liquid crystal and glue, wherein the dichroic dye liquid crystal comprises a dichroic dye and the liquid crystal composition as described above.

[0034] Preferably, the dichroic dye glue includes but is not limited to acrylate photocurable glue, and preferably is acrylate photocurable glue.

[0035] Preferably, the dichroic dye PDLC comprises a dichroic dye liquid crystal and acrylate photocurable glue with a mass ratio of 1:1.

[0036] Preferably, the dichroic dye PDLC further comprises spacer microspheres.

[0037] Preferably, the dichroic dye PDLC further comprises spacer microspheres with a mass percentage of 3‰.

[0038] The present invention also provides an application of the liquid crystal composition as described above in a liquid crystal display device.

[0039] The working principle and beneficial effects of the present invention are as follows:

[0040] 1. The liquid crystal composition obtained by combining specific proportions of compounds of the present invention can be used to prepare a dye PDLC with a high contrast ratio after dissolving a dichroic dye. Detailed implementation manners

[0041] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0042] It should be noted that for the description of the structural formulas and chemical formulas in the embodiments or implementation schemes of the present invention, the present invention intends to cover all alternative, modified and equivalent technical solutions, which should be regarded as being included within the scope of the present invention. Those skilled in the art should understand that many similar or equivalent methods and materials can be used to implement the present invention, so the present invention is not limited to the specific methods and materials described. In the case of differences or contradictions between the cited literature, patents or similar materials and the present application (including but not limited to term definitions, term applications, technologies described, etc.), the content of the present invention shall prevail.

[0043] The liquid crystal monomer structures in the embodiments of the present invention are represented by codes, and the code representation method corresponding to the liquid crystal structure is shown in Table 1 below.

[0044] Table 1 Codes corresponding to structures

[0045]

[0046] For example:

[0047] Its code is PP-2-N;

[0048] Its code is PP-2O-N;

[0049] Its code is PGP-2-3;

[0050] Its code is CZPP-2-N;

[0051] Its code is PZPP-5-N;

[0052] Its code is PZPC-1O-5;

[0053] Its code is PZPC-3O-5;

[0054] Its code is CPZP-5-N;

[0055] Its code is PZP-3-5.

[0056] The liquid crystal composition provided by the present invention comprises one or more compounds represented by Formula I,

[0057]

[0058] wherein R 1 represents an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms;

[0059] In a preferred example, the compound represented by the foregoing Formula I is selected from one or more of the compounds represented by Formula I-1 to Formula I-8:

[0060]

[0061]

[0062] The liquid crystal composition of the present invention further comprises one or more compounds represented by Formula II,

[0063]

[0064] wherein R 2 represents an alkyl group having 1 to 10 carbon atoms; Y 1 represents a cyano group or an alkyl group having 1 to 10 carbon atoms;

[0065] In a preferred example, the compound represented by the foregoing Formula II is selected from one or more of the compounds represented by Formula II-1 to Formula II-3:

[0066]

[0067] The liquid crystal composition of the present invention further comprises one or more compounds represented by Formula III,

[0068]

[0069] wherein R 3 represents an alkyl group having 1 to 10 carbon atoms;

[0070] represents

[0071] In a preferred example, the compound represented by the foregoing Formula III is selected from one or more of Formula III-1 to Formula III-4:

[0072]

[0073] Furthermore, the liquid crystal composition further comprises one or more compounds represented by Formula IV,

[0074]

[0075] wherein R 4 represents an alkyl group having 1 to 10 carbon atoms; Y 1 represents a cyano group or an alkyl group having 1 to 10 carbon atoms;

[0076] represents

[0077] In a preferred example, the compound represented by Formula IV is selected from one or more of Formula IV-1 to Formula IV-5:

[0078]

[0079] Preferably, the liquid crystal composition comprises at least two or three compounds represented by Formula I, at least one compound represented by Formula II, at least two or three compounds represented by Formula III, and none or at least one compound represented by Formula IV.

[0080] The liquid crystal composition provided by the present invention comprises 35 to 60% by mass of the compound represented by Formula I, 10 to 25% by mass of the compound represented by Formula II, 15 to 25% by mass of the compound represented by Formula III, and 0 to 20% by mass of the compound represented by Formula IV.

[0081] As used herein, "alkyl" refers to a straight-chain or branched hydrocarbon chain group that is fully saturated (without double or triple bonds). The alkyl group can have 1 to 10 carbon atoms (whenever a numerical range such as "1 to 10" appears herein, for example, the numerical range refers to each integer within the given range; for example, "1 to 10 carbon atoms" means that the alkyl group can consist of 1 carbon atom, 2 carbon atoms, 3 carbon atoms, etc., up to and including 10 carbon atoms).

[0082] Examples of the aforementioned alkyl group having 1 to 10 carbon atoms include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, hexyl, heptyl, octyl, nonyl, and decyl.

[0083] Examples of the aforementioned alkoxy group having 1 to 10 carbon atoms include, but are not limited to, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, and decyloxy.

[0084] In the embodiments of the present invention, there are no special restrictions on the sources of various instruments, equipment, raw materials or reagents used. They are all conventional products that can be obtained through regular commercial channels, and can also be prepared according to the conventional methods well-known to those skilled in the art.

[0085] In the present invention, the dichroic dye liquid crystal refers to a mixture of dichroic dye monomers and a liquid crystal composition; the dichroic dye PDLC refers to, including but not limited to, a mixture of glue and dichroic dye liquid crystal.

[0086] In the present invention, the preparation methods are all conventional methods unless otherwise specified, and the raw materials used can be obtained from public commercial channels unless otherwise specified. The percentages are all by mass. The liquid crystal compound is also called a liquid crystal monomer. The specific meanings of other symbols and the test conditions are as follows:

[0087] The preparation method of the liquid crystal composition is as follows: Weigh each liquid crystal monomer according to a certain ratio and put it into a stainless steel beaker. Place the stainless steel beaker containing each liquid crystal monomer on a magnetic stirring instrument and heat it to melt. After most of the liquid crystal monomers in the stainless steel beaker have melted, add a magnetic rotor to the stainless steel beaker, stir the mixture evenly, and cool it to room temperature to obtain the liquid crystal composition.

[0088] The present invention provides a dichroic dye liquid crystal, which comprises a dichroic dye and the liquid crystal composition of the present invention, wherein the dichroic dye accounts for 0.1-10% of the total weight of the dichroic dye liquid crystal;

[0089] As some embodiments of the present invention, the dichroic dye accounts for 0.1-0.5% of the total weight of the dichroic dye liquid crystal;

[0090] As some embodiments of the present invention, the dichroic dye includes but is not limited to anthraquinone dichroic dyes or benzopyrene dyes;

[0091] The present invention also provides a dichroic dye PDLC, which comprises a dichroic dye liquid crystal and glue; as some embodiments of the present invention, the glue includes but is not limited to acrylate photocurable glue. There are no special restrictions on the source of this glue. It is a conventional product that can be obtained through regular commercial channels, and can also be prepared according to the conventional methods well-known to those skilled in the art.

[0092] The preparation methods of the dichroic dye PDLC in the following examples and comparative examples are as follows:

[0093] (1) Dissolve the dichroic dye monomer CB-001 (benzopyrene type, purchased from Hebei Paiyue Biotechnology Co., Ltd.) in the liquid crystal composition. After complete dissolution, a dichroic dye liquid crystal is obtained. Mix the dichroic dye liquid crystal and glue DPL195 (acrylate photocurable glue) at a mass ratio of 1:1 to obtain a dichroic dye PDLC liquid. Add 20-μm spacer microspheres (purchased from Suzhou NanoMicro Technology Co., Ltd.), and perform lamination using a roll-to-roll process and curing using the polymer phase separation technique (where the curing light intensity is 10 mW / cm 2 , and the curing temperature is 25 °C) to obtain dichroic dye PDLC; among them, the dichroic dye monomer CB-001 accounts for 0.5% of the total weight of the dichroic dye liquid crystal, and the dosage of the spacer microspheres is 3‰ of the dichroic dye PDLC liquid. Composition and preparation method of glue DPL195: 30% of polyurethane acrylate LuCure8674 (Runao Chemical Industry), 11% of hydroxypropyl acrylate, 15% of acryloylmorpholine, 10% of pentaerythritol tetraacrylate, 10% of dodecyl acrylate, 10% of benzyl acrylate, 5% of isobornyl acrylate, 8% of 1,6-hexanediol diacrylate, 1% of 819 photoinitiator. After mixing, heat to 45 °C and stir evenly;

[0094] (2) Dissolve the dichroic dye monomer KH5 (anthraquinone dye, purchased from Oulaiyide Laboratory, Taiyuan, Shanxi) in the liquid crystal composition. After complete dissolution, a dichroic dye liquid crystal is obtained. Mix the dichroic dye liquid crystal and glue DPL195 at a mass ratio of 1:1 to obtain a dichroic dye PDLC liquid. Add 20-μm spacer microspheres (purchased from Suzhou NanoMicro Technology Co., Ltd.), and perform lamination using a roll-to-roll process and curing using the polymer phase separation technique (where the curing light intensity is 10 mW / cm 2 , and the curing temperature is 25 °C) to obtain dichroic dye PDLC; among them, the dichroic dye monomer KH5 accounts for 0.5% of the total weight of the dichroic dye liquid crystal, and the dosage of the spacer microspheres is 3‰ of the dichroic dye PDLC liquid.

[0095] (3) Dissolve the dichroic dye monomer CB-001 (purchased from Hebei Paiyue Biotechnology Co., Ltd.) in the liquid crystal composition. After complete dissolution, a dichroic dye liquid crystal is obtained. Mix the dichroic dye liquid crystal and glue DPL202 (acrylate photocurable glue) at a mass ratio of 1:1 to obtain a dichroic dye PDLC liquid. Add 20-μm spacer microspheres (purchased from Suzhou NanoMicro Technology Co., Ltd.), and perform lamination using a roll-to-roll process and curing using the polymer phase separation technique (where the curing light intensity is 10 mW / cm 2, The curing temperature was 25 °C) to obtain the dichroic dye PDLC; among them, the dichroic dye monomer CB-001 accounted for 0.5% of the total weight of the dichroic dye liquid crystal, and the dosage of the spacer microspheres was 3‰ of the dichroic dye PDLC liquid. Composition and preparation method of glue DPL202: 35% of polyurethane acrylate LuCure8674 (Runao Chemical Industry), 8% of hydroxyethyl acrylate, 10% of acryloylmorpholine, 8% of pentaerythritol tetraacrylate, 12% of dodecyl acrylate, 8% of benzyl acrylate, 5% of isobornyl acrylate, 13% of 1,4-butanediol diacrylate, 1% of photoinitiator 819, and after mixing, heated to 45 °C and stirred evenly;

[0096] Performance test of dichroic dye PDLC: At room temperature, use the color spectrum haze meter TH-110 to test the T off and T on of the dye PDLC, and calculate its contrast ratio CR;

[0097] T off represents the total light transmittance (%) of the dichroic dye PDLC in the dark state;

[0098] T on represents the total light transmittance (%) of the dichroic dye PDLC in the bright state;

[0099] CR represents the contrast ratio of the dichroic dye PDLC, CR = T off / T on .

[0100] Example 1

[0101] The formulation of the liquid crystal composition and the corresponding properties are shown in Table 2 below.

[0102] Table 2

[0103]

[0104] Example 2

[0105] The formulation of the liquid crystal composition and the corresponding properties are shown in Table 3 below.

[0106] Table 3

[0107]

[0108] Example 3

[0109] The formulation of the liquid crystal composition and the corresponding properties are shown in Table 4 below.

[0110] Table 4

[0111]

[0112] Example 4

[0113] The formulation of the liquid crystal composition and the corresponding properties are shown in Table 5 below.

[0114] Table 5

[0115]

[0116] Example 5

[0117] The formulation of the liquid crystal composition and the corresponding properties are shown in Table 6 below.

[0118] Table 6

[0119]

[0120]

[0121] Example 6

[0122] The formulation of the liquid crystal composition and the corresponding properties are shown in Table 7 below.

[0123] Table 7

[0124]

[0125] Example 7

[0126] The formulation of the liquid crystal composition and the corresponding properties are shown in Table 8 below.

[0127] Table 8

[0128]

[0129]

[0130] Example 8

[0131] The formulation of the liquid crystal composition and the corresponding properties are shown in Table 9 below.

[0132] Table 9

[0133]

[0134] Example 9

[0135] The formulation of the liquid crystal composition and the corresponding properties are shown in Table 10 below.

[0136] Table 10

[0137]

[0138]

[0139] Example 10

[0140] The formulation of the liquid crystal composition and the corresponding properties are shown in Table 11 below.

[0141] Table 11

[0142]

[0143] All the liquid crystal monomers used in the liquid crystal composition in the above examples are liquid crystal monomers with benzene ring conjugation in specific ratios, including PP conjugation, PGP conjugation, or PPP conjugation. The PDLC contrast of the dye CB-001 made from them is > 2.10, and the PDLC contrast of the dye KH5 is > 2.30.

[0144] Comparative Example 1

[0145] The formulation of the liquid crystal composition and the corresponding properties are shown in Table 12 below.

[0146] Table 12

[0147]

[0148]

[0149] Compared with Example 4, in the liquid crystal composition of Comparative Example 1, the amount of the liquid crystal monomer of the compound shown in Formula I is reduced by 5 parts, and 5 parts of PZPC and CPZP type liquid crystal monomers are added. The T of the dye PDLC off increases significantly, and the contrast becomes worse;

[0150] Comparative Example 2

[0151] The formulation of the liquid crystal composition and the corresponding properties are shown in Table 13 below.

[0152] Table 13

[0153]

[0154] Compared with Example 5, in the liquid crystal composition of Comparative Example 2, after the amount of the liquid crystal monomer of the compound shown in Formula II is reduced, PZPC and PZP type liquid crystal monomers are added. The T of the dye PDLC off increases, and the contrast becomes worse;

[0155] Comparative Example 3

[0156] The formulation of the liquid crystal composition and the corresponding properties are shown in Table 14 below.

[0157] Table 14

[0158]

[0159]

[0160] Compared with Example 6, in Comparative Example 3, the PZPC liquid crystal monomer structure was added, and the dye PDLC T off The contrast ratio decreased significantly.

[0161] In summary, after the liquid crystal composition of the present invention dissolves the dichroic dye, compared with the ordinary liquid crystal composition, a dye PDLC with a high contrast ratio can be prepared. Therefore, it can be used as a liquid crystal for dichroic dyes and can be used to develop dye PDLCs of various colors in combination with dichroic dyes.

[0162] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A liquid crystal composition, characterized in that: The liquid crystal composition comprises one or more compounds of formula I, one or more compounds of formula II and one or more compounds of formula III; Wherein, R1 represents an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms; R2 and R3 each independently represent an alkyl group having 1 to 10 carbon atoms; Y1 represents a cyano group or an alkyl group having 1 to 10 carbon atoms; express 2. A liquid crystal composition according to claim 1, characterized in that: The liquid crystal composition further comprises one or more compounds represented by formula IV; wherein R4 represents an alkyl group having 1 to 10 carbon atoms; Y1 represents a cyano group or an alkyl group having 1 to 10 carbon atoms; express 3. A liquid crystal composition according to claim 1, characterized in that: The compound represented by Formula I is selected from one or more of the compounds represented by Formula I-1 to Formula I-8: And / or, the compound represented by formula II is selected from one or more of the compounds represented by formula II-1 to formula II-3: And / or, the compound represented by formula III is selected from one or more of the compounds represented by formula III-1 to formula III-4:

4. A liquid crystal composition according to claim 2, characterized in that: The compound represented by formula IV is selected from one or more of the compounds represented by formula IV-1 to formula IV-5:

5. A liquid crystal composition according to claim 1, characterized in that: The liquid crystal composition comprises the following components in percentage by mass: 35-60% of the compound represented by formula I, 10-25% of the compound represented by formula II, 15-25% of the compound represented by formula III, and 0-20% of the compound represented by formula IV; Alternatively, the liquid crystal composition comprises the following components in percentage by mass: 35-50% of the compound represented by formula I, 15-20% of the compound represented by formula II, 17-25% of the compound represented by formula III, and 0-20% of the compound represented by formula IV.

6. A liquid crystal composition according to claim 5, characterized in that: The compound represented by the formula II is a mixture of the compounds represented by II-1 and II-2; The compounds represented by the formula I include but are not limited to the compounds represented by I-8; The compound represented by formula III is a mixture of compounds represented by III-1, III-2 and III-4; The compound represented by formula IV is a mixture of compounds represented by IV-1, IV-2, IV-3 and IV-4.

7. Use of the liquid crystal composition according to any one of claims 1 to 6 in dichroic dye liquid crystals.

8. Use of the liquid crystal composition according to claim 7 in dichroic dye liquid crystals, characterized in that: The dichroic dye liquid crystal comprises a dichroic dye and the liquid crystal composition of any one of claims 1 to 6, wherein the dichroic dye accounts for 0.1 to 10% of the total weight of the dichroic dye liquid crystal; Or, the dichroic dye accounts for 0.1 to 0.5% of the total weight of the dichroic dye liquid crystal; Wherein, the dichroic dye is an anthraquinone dichroic dye or a benzopyrene dye.

9. Use of the liquid crystal composition according to any one of claims 1 to 6 in dichroic dye PDLC, characterized in that: The dichroic dye PDLC comprises a dichroic dye liquid crystal and glue, wherein the dichroic dye liquid crystal comprises a dichroic dye and the liquid crystal composition according to any one of claims 1 to 6.

10. Use of the liquid crystal composition according to any one of claims 1 to 6 in a liquid crystal display device.

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