Polymerizable blue dyes and preparation methods thereof

Abstract

A polymerizable blue dye having a structure of general formula (1) is disclosed. In addition, a preparation method of the blue dye, a polymerizable liquid crystal composition including the blue dye and a host liquid crystal, and an optically anisotropic body formed by curing the composition are also disclosed. The blue dye has good light absorption characteristics similar to C.I. Solvent Blue 104, and at the same time, its anti-aging performance after long-term exposure to sunlight is significantly improved.

Description

Technical Field

[0001] The present invention relates to a polymerizable blue dye and a preparation method thereof, belonging to the technical field of display materials. Background Art

[0002] Polymerizable compounds (RM) are increasingly attracting wide attention as raw materials for preparing various optically anisotropic bodies. In the prior art, a solution of a polymerizable compound is usually coated on a substrate, aligned, and cured by heating or irradiating an activation energy ray to form an optically anisotropic polymer film with a uniform orientation, also known as an optically anisotropic body.

[0003] According to different application fields, the optically anisotropic body includes, but is not limited to, an optical retardation film (phase difference film), an optical compensation film, a visual expansion film, a reflection film, a selective reflection film, an antireflection film, a brightness enhancement film, a liquid crystal alignment film, a polarizing film, a polarizing element, a circular polarizing element, an elliptical polarizing element, and various other optical elements.

[0004] In some specific applications, an organic dye is mixed into a solution of a polymerizable compound, and after curing, a uniform colored optically anisotropic body is formed.

[0005] As an organic dye, C.I. Solvent Blue 104 has been used as a blue dye, and this dye has good light absorption characteristics.

[0006] However, the anti-aging performance of the optically anisotropic body formed by C.I. Solvent Blue 104 is still not satisfactory after long-term exposure to sunlight. Summary of the Invention

[0007] The purpose of the present invention is to provide a polymerizable blue dye and a preparation method thereof. Compared with C.I. Solvent Blue 104, the polymerizable blue dye has similar good light absorption characteristics, and at the same time, the anti-aging performance of the formed optically anisotropic body is significantly improved after long-term exposure to sunlight.

[0008] To achieve the above purpose, the present invention provides a polymerizable blue dye having a structure of general formula (1):

[0009]

[0010] In the formula,

[0011] P1 and P2 represent polymerizable groups;

[0012] L1 and L2 each independently represent an alkylene group having 1 to 30 carbon atoms; one or more -CH2- in the alkylene group may be substituted by -O-, -S-, -NH-, -NR a -, -CO-, -OCO-, -COO-, -SCO-, -COS-;

[0013] R a represents an alkyl group having 1 to 30 carbon atoms;

[0014] R1, R2, R3, R4 and R5 each independently represent H, halogen, an alkyl group having 1 to 30 carbon atoms, a haloalkyl group having 1 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, a haloalkoxy group having 1 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, a haloalkenyl group having 2 to 30 carbon atoms, an alkenyloxy group having 2 to 30 carbon atoms, a haloalkenyloxy group having 2 to 30 carbon atoms, an alkoxycarbonyl group having 1 to 30 carbon atoms, a haloalkoxycarbonyl group having 1 to 30 carbon atoms, an alkylcarbonyl group having 1 to 30 carbon atoms, a haloalkylcarbonyl group having 1 to 30 carbon atoms, an alkylacyloxy group having 1 to 30 carbon atoms or a haloalkylacyloxy group having 1 to 30 carbon atoms.

[0015] In the present invention, the number of carbon atoms of the alkylene group can be 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 and 30.

[0016] Similarly, the number of carbon atoms of the alkyl group can be 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 and 30.

[0017] Likewise, the number of carbon atoms of the haloalkyl group, alkoxy group, haloalkoxy group, alkoxycarbonyl group, haloalkoxycarbonyl group, alkylcarbonyl group, haloalkylcarbonyl group, alkylacyloxy group or haloalkylacyloxy group can all be 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 and 30. The number of carbon atoms of the alkenyl group, haloalkenyl group, alkenyloxy group or haloalkenyloxy group can all be 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 and 30.

[0018] As the halogen, it includes fluorine, chlorine, bromine and iodine.

[0019] As the polymerizable blue dye described in the context, wherein the polymerizable group is selected from the following groups:

[0020]

[0021] In the formula,

[0022] Each R6 independently represents a hydrogen atom, a halogen, a cyano group, an alkyl group having 1 to 30 carbon atoms, or a halogenated alkyl group having 1 to 30 carbon atoms.

[0023] As the polymerizable blue dye described in the context, wherein P1 and P2 each independently represent a group of (P-1) and (P-2).

[0024] Preferably, P1 and P2 each independently represent a group of (P-1).

[0025] As the polymerizable blue dye described in the context, wherein each R6 independently represents a hydrogen atom, a halogen, a methyl group, or a trifluoromethyl group.

[0026] Preferably, each R6 independently represents a hydrogen atom, fluorine, chlorine, or a methyl group.

[0027] More preferably, each R6 independently represents a hydrogen atom or a methyl group.

[0028] Preferably, R a represents an alkyl group having 2 to 28, 2 to 25, 2 to 22, 2 to 20, 2 to 18, 2 to 15, 2 to 12, 2 to 10, 2 to 8, 2 to 6, 3 to 27, 3 to 24, 3 to 21, 3 to 18, 3 to 15, 3 to 12, 3 to 10, 3 to 8, or 3 to 6 carbon atoms.

[0029] As the polymerizable blue dye described in the context, wherein L1 and L2 each independently represent an alkylene group having 1 to 30 carbon atoms; one or more -CH2- in the alkylene group may be substituted with -O- or -S-.

[0030] Preferably, L1 and L2 each independently represent an alkylene group having 1 to 30 carbon atoms; one or more -CH2- in the alkylene group may be substituted with -O- or -S-.

[0031] More preferably, L1 and L2 each independently represent an alkylene group having 1 to 30 carbon atoms.

[0032] Further preferably, L1 and L2 each independently represent an alkylene group having 2 to 28, 2 to 25, 2 to 22, 2 to 20, 2 to 18, 2 to 15, 2 to 12, 2 to 10, 2 to 8, 2 to 6, 3 to 27, 3 to 24, 3 to 21, 3 to 18, 3 to 15, 3 to 12, 3 to 10, 3 to 8, or 3 to 6 carbon atoms.

[0033] As the polymerizable blue dye described in the context, wherein R1, R2, R3, R4, and R5 each independently represent H, a halogen, an alkyl group having 1 to 30 carbon atoms, a halogenated alkyl group having 1 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, or a halogenated alkoxy group having 1 to 30 carbon atoms.

[0034] As the polymerizable blue dye described in the context, wherein, R1 and R3 represent alkyl groups having 1 to 30 carbon atoms; R2 and R4 represent H.

[0035] Preferably, R1 and R3 each independently represent alkyl groups having 2 to 28, 2 to 25, 2 to 22, 2 to 20, 2 to 18, 2 to 15, 2 to 12, 2 to 10, 2 to 8, 2 to 6, 3 to 27, 3 to 24, 3 to 21, 3 to 18, 3 to 15, 3 to 12, 3 to 10, 3 to 8, and 3 to 6 carbon atoms.

[0036] As the polymerizable blue dye described in the context, wherein R5 each independently represents H.

[0037] In a specific embodiment, as the polymerizable blue dye described in the context, it is selected from the following specific compounds

[0038]

[0039] On the other hand, the present invention also provides a method for preparing the polymerizable blue dye described in the context, the method comprising the step of reacting a compound of general formula (2) with compounds of general formula (3) and general formula (4);

[0040]

[0041] P1-L1-X(3)

[0042] P2-L2-X(4)

[0043] In the formula, P1-P2, L1-L2, R1-R5 are as described in the context of the present invention; X is a leaving group.

[0044] In yet another aspect, the present invention further provides a polymerizable liquid crystal composition comprising the polymerizable blue dye described in the context and a host liquid crystal.

[0045] As the polymerizable liquid crystal composition described in the context, it further comprises a photosensitive adhesive.

[0046] Finally, the present invention provides an optically anisotropic body formed by curing the polymerizable liquid crystal composition described in the context.

[0047] Without wishing to be bound by any theory, as the polymerizable blue dye of the present invention, due to its polymerizable properties, polymerization occurs during the process of manufacturing the film, and the stability is greatly enhanced. It has similar good light absorption characteristics to C.I. Solvent Blue 104, and at the same time, the anti-aging performance of the formed optically anisotropic body is significantly improved after long-term exposure to sunlight. Description of the Drawings

[0048] Figure 1It is the absorbance curve of the compound P1 of the present invention;

[0049] Figure 2 It is the absorbance curve of C.I. Solvent Blue 104. Detailed implementation mode

[0050] In the present invention, technical terms are further explained and defined in detail.

[0051] The term "liquid crystal" or "mesogenic compound" refers to a compound that forms a mesophase or liquid crystal phase under certain conditions.

[0052] The term "polymerizable group" refers to a group that polymerizes by means of light, heat, catalyst, etc. to form a polymer with a higher molecular weight.

[0053] The term "host" refers to the main component.

[0054] The present invention will be further illustrated below in conjunction with synthesis examples and examples, without limiting the application of the present invention. Unless otherwise specified, the percentages in the examples are all mass percentages.

[0055] Synthesis example

[0056]

[0057] Preparation of intermediate S-3

[0058] Take 100 g of S-1 and add it to a 1000 ml reaction flask, then add 300 ml of N,N-dimethylformamide. Add 93.6 g of triethylamine, keep the temperature at about 25 °C, and dropwise add 106.5 g of S-2 thereto. After the dropwise addition is completed, raise the temperature to 70-80 °C and react for 6 h. After the reaction is completed, cool down, add the reaction solution to 1000 ml of water, precipitate a solid, and then filter and dry it to obtain 116 g of intermediate S-3. The yield is 82%.

[0059] Preparation of intermediate S-6

[0060] Take 100 g of S-4 and add it to a 1000 ml three-necked flask, then add 400 ml of dichloromethane. Under nitrogen protection, add 91 g of triethylamine; then cool down to below 0 °C and dropwise add 95.3 g of S-5, and keep the dropping temperature at below 0 °C as well. After the dropwise addition is completed, raise the temperature to 25 °C and react for 2 h. After the reaction is completed, add 200 g of water, wash once with water, dry the organic phase, pass through a chromatography column, and concentrate and dry the chromatography eluent to obtain 144.9 g of intermediate S-6. The yield is 94%.

[0061] Preparation of product P1

[0062] 50 g of S-3 was added to a 500 ml reaction flask, followed by the addition of 60.1 g of S-6, 250 ml of N,N-dimethylformamide, and 72.3 g of potassium carbonate. The temperature was raised to 80 - 85 °C and the reaction was carried out for 8 h. After the reaction was completed, the reaction solution was added to 500 g of water, and a solid was precipitated. The solid was filtered by suction and dried to obtain 63 g of a crude product. Then, the crude product was dissolved in 500 g of dichloromethane and 10 g of triethylamine, passed through a chromatography column, and the chromatography solution was concentrated to dryness to obtain 50 g of a solid. The solid was then slurried and crystallized with 250 g of isopropanol. The product was filtered by suction and dried to obtain 45.6 g of the polymerizable blue dye product P1. The yield was 55%. 1 H NMR (DMSO) δ: 0.89 - 0.91 (t, 6H), 1.35 - 1.37 (t, 4H), 1.47 - 1.48 (d, 2H), 1.88 - 1.90 (t, 10H), 3.28 - 3.31 (t, 4H), 3.98 - 4.01 (t, 6H), 4.14 - 4.16 (t, 4H), 5.20 - 5.21 (d, 2H), 5.31 - 5.23 (d, 2H), 5.55 - 5.57 (d, 2H), 7.01 - 7.03 (d, 2H), 7.12 - 7.14 (d, 2H).

[0063] Absorption characteristics

[0064] Figure 1 is the absorbance curve of the polymerizable blue dye P1 of the present invention; Figure 2 is the absorbance curve of C.I. Solvent Blue 104. It can be seen from the two absorbance curves that the absorbances of the two dyes are basically similar and there is no obvious difference.

[0065] The structural formula of the blue dye C.I. Solvent Blue 104 is as follows:

[0066]

[0067] Anti-aging characteristics

[0068] 3% of C.I. Solvent Blue 104 was added to the liquid crystal matrix M, and then the liquid crystal matrix M was mixed with the photosensitive adhesive in a ratio of 1:1 to form a coating solution. The coating solution was spin-coated on the glass and then cured by ultraviolet light irradiation (the curing agent used was a one-component acrylic curing adhesive CV3003, purchased from ShinEtsu Chemical Co., Ltd.) to obtain Comparative Example 1.

[0069] 3% of the polymerizable blue dye P1 was added to the liquid crystal matrix M, and then the liquid crystal matrix M was mixed with the photosensitive adhesive in a ratio of 1:1 to form a coating solution. The coating solution was spin-coated on the glass and then cured by ultraviolet light irradiation (the curing agent used was a one-component acrylic curing adhesive CV3003, purchased from ShinEtsu Chemical Co., Ltd.) to obtain Example 1.

[0070] The host liquid crystal M is composed of the following compounds M-1: 30%, compound M-2: 30%, and compound M-3: 40% known from Patent JP 2007-51440.

[0071]

[0072] The two glass diaphragms obtained in Example 1 and Comparative Example 1 were subjected to a sun exposure aging experiment, and a solar film tester LS182 was used to test the transmittance change of each sample after long-term (5 months) sun exposure. The results are shown in Table 1.

[0073] Table 1

[0074] Time The 1st month The 2nd month The 3rd month The 4th month The 5th month Comparative Example 1 33％ 33％ 35％ 37％ 43％ Example 2 32％ 32％ 32％ 33％ 33％

[0075] As can be seen from Table 1, as time extends, the transmittance of the glass diaphragm in Comparative Example 1 becomes larger and larger, indicating that its function deteriorates during the sun exposure process. However, the transmittance of the glass diaphragm in Example 1 remains basically unchanged. Through the sun exposure aging experiment, it is sufficient to prove that the stability of the polymerizable blue dye of the present invention is greatly enhanced, thereby improving the anti-aging performance.

[0076] It should be understood that the specific embodiments of the present invention are only used to illustrate the spirit and principles of the present invention, rather than to limit the scope of the present invention. In addition, it should be understood that after reading the content of the present invention, those skilled in the art can make various changes, substitutions, deletions, corrections or adjustments to the technical solutions of the present invention, and these equivalent technical solutions also fall within the scope defined by the claims of the present invention.

Claims

1. A polymerizable blue dye, characterized in that, The polymerizable blue dye is selected from the following specific compounds, 2. A method for preparing the polymerizable blue dye according to claim 1, the method comprising the step of reacting a compound of formula (S-3) with a compound of formula (S-6); 3. A polymerizable liquid crystal composition, characterized in that, comprising the polymerizable blue dye according to claim 1 and a host liquid crystal.

4. The polymerizable liquid crystal composition according to claim 3, further comprising a photosensitive adhesive.

5. An optically anisotropic body formed by curing the polymerizable liquid crystal composition according to claim 3.

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