Azo blue dichroic dye compound and application thereof
By designing azo blue dichroic dye compounds, the problems of easy isomerization and orientation disorder of existing blue dichroic dyes at high temperatures were solved, and the performance stability under high temperature environment was improved, expanding their application in high-end optical devices.
Patent Information
- Application Number
- CN202610026014.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-09
- Publication Date
- 2026-04-17
AI Technical Summary
Existing blue dichroic dyes are prone to isomerization and orientation disorder at high temperatures, which leads to a decrease in the blue light blocking performance of tinted glass and limits its promotion in high-temperature applications.
A blue dichroic dye compound was designed by precisely designing substituents, including non-perhydrogen combinations of R2 (-H, -CH3, or -F) and R3 (-CH3 or -H), to restrict the thermal isomerization of the azo bond, and by limiting R1 and R4 to C1~C6 saturated alkyl groups to enhance the compatibility of the molecule with the liquid crystal medium.
It significantly improves the high-temperature stability of dyes, ensuring stable performance at temperatures above 60°C, solving the problem of decreased blue light blocking performance of tinting glass, and expanding its application range in the field of high-end optical devices.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of organic optical materials technology, and particularly relates to an azo blue dichroic dye compound and its applications. Background Technology
[0002] Blue dichroic dyes are a class of functional dyes with conjugated aromatic structures. Their molecules can be oriented in an ordered medium, exhibiting significant differences in absorption of blue light with different polarization directions, i.e., dichroism. These dyes are often mixed with liquid crystals to form "dye liquid crystals"—utilizing the response of liquid crystal molecules to an external field to synchronously regulate the dye orientation, thereby achieving dynamic control of light transmittance and color. Currently, they are mainly used in fields such as smart glass and tinted glasses. For example, by adding acrylic resin, tinted glass similar to PDLC can be prepared, and it is gradually being promoted in markets such as automotive sunroofs.
[0003] Most existing blue dichroic dyes employ azo bond-linked polyphenylene-fused-ring aromatic structures, such as conjugated systems containing 1 to 3 -N=N- bonds, with substituents mostly being C1 to C6 alkyl groups. Although such structures can ensure dichroism in the blue light band, the azo bonds in the molecule are prone to isomerization at high temperatures, and the weak interactions between conjugated chains are easily destroyed by thermal motion.
[0004] Formula I-0.
[0005] As shown in Formula I-0, the existing blue dichroic dye structure contains isopropyl amino substituents at its end. In automotive displays where long-term tolerance to ambient temperatures above 60°C is required, dye orientation disorder and dichroic decay are likely to occur, leading to a decrease in the blue light blocking performance of the tinted glass and limiting its promotion in high-temperature applications. Summary of the Invention
[0006] To address the problem of insufficient thermal stability of existing blue dichroic dye compounds, this invention provides an azo blue dichroic dye compound and its applications.
[0007] The technical solution of the present invention:
[0008] An azo blue dichroic dye compound having the structure shown in Formula I:
[0009] Formula I;
[0010] In this context, R1 and R4 are independently selected from C1-C6 saturated alkyl substituents, R2 represents -H, CH3, or -F, and R3 represents a hydrogen atom or a C atom. 1- A C6 saturated alkyl substituent, and R2 and R3 cannot both be hydrogen atoms.
[0011] Furthermore, the compound has the structures shown in formulas I-1 to I-5:
[0012] Formula I-1
[0013] Formula I-2
[0014] Formula I-3
[0015] Formula I-4
[0016] Among them, R1, R3, and R4 are C1-C6 saturated alkyl substituents.
[0017] Furthermore, the saturated alkyl substituents of the C1-C6 groups are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, sec-pentyl, tert-pentyl, n-hexyl, or neohexyl.
[0018] Additionally, the following structures are also possible:
[0019] Formula I-5
[0020] Among them, R1, R3, and R4 are C1-C6 saturated alkyl substituents.
[0021] Furthermore, the saturated alkyl substituents of the C1-C6 groups are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, sec-pentyl, tert-pentyl, n-hexyl, or neohexyl.
[0022] The synthetic route of the azo blue dichroic dye compound of this invention is as follows:
[0023]
[0024] Furthermore, the application of the azo blue dichroic dye compound provided by the present invention in the preparation of liquid crystal display devices and dimming glass is disclosed.
[0025] Furthermore, the azo blue dichroic dye compound, alone or in combination with at least one commercial dichroic dye, is mixed with commercial single crystals or mixed crystals to obtain a liquid crystal mixture, which is used as a functional layer material to prepare the liquid crystal display device.
[0026] Furthermore, the azo blue dichroic dye compound, alone or in combination with at least one commercial dichroic dye, is mixed with commercial single crystal or mixed crystal to obtain a liquid crystal mixture. The liquid crystal mixture is then mixed with PDLC using a polymer to formulate an intelligent dimming functional system. After coating and photocuring, the functional system forms the core dimming layer of the dimming glass.
[0027] Furthermore, the commercially available dichroic dyes are azo dichroic dyes and / or anthraquinone dichroic dyes.
[0028] The beneficial effects of this invention are:
[0029] This invention provides an azo blue dichroic dye compound as shown in Formula I through precise substituent design, significantly improving its performance stability at high temperatures. Firstly, this invention effectively suppresses the risk of thermal isomerization of the azo bond through a non-per-hydrogen combination design of R2 (-H, -CH3, or -F) and R3 (-CH3 or -H). Simultaneously, this invention limits R1 and R4 to C1-C6 saturated alkyl groups, enhancing the compatibility of the molecule with the liquid crystal medium and preventing dye molecule aggregation under high-temperature conditions.
[0030] The high-temperature stability of the azo blue dichroic dye compound of this invention directly meets the requirements of high-temperature applications such as automotive sunroofs. Its performance shows relative improvement during long-term use above 60°C, solving the problem of decreased blue light blocking performance in tinted glass. Furthermore, while maintaining dichroism in the blue light band, this structure exhibits superior compatibility with acrylic resins, allowing it to be directly used in the fabrication of high-performance PDLC tinted glass, thus expanding the application range of blue dichroic dyes in high-end optical devices. Detailed Implementation
[0031] The technical solution of the present invention will be further described below with reference to embodiments, but it is not limited thereto. Any modifications or equivalent substitutions to the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention should be covered within the protection scope of the present invention. In the following embodiments, the process equipment or apparatus not specifically specified are all conventional equipment or apparatus in the art. Unless otherwise specified, the raw materials used in the embodiments of the present invention are all commercially available; unless otherwise specified, the technical means used in the embodiments of the present invention are all conventional means well known to those skilled in the art.
[0032] Example 1
[0033] This embodiment provides an azo blue dichroic dye compound and its preparation method.
[0034] In this embodiment, the azo blue dichroic dye compound I-1' has the structure shown in formula I-1':
[0035] Formula I-1',
[0036] R1 is n-pentyl.
[0037] The preparation method of the azo blue dichroic dye compound I-1' in this embodiment is as follows:
[0038] Step 1: Synthesis of intermediate A1:
[0039] 0.1 mol of 2-methyl-4-bromoaniline, 0.12 mol of hydrochloric acid, and 1000 ml of methanol were added to a three-necked flask. The mixture was stirred and cooled to 0-5 °C. 0.1 mol of sodium nitrite aqueous solution was added dropwise. After the addition was complete, the temperature was controlled and the reaction was carried out for 4 h. 0.1 mol of 1-naphthylamine was added, and the temperature was controlled at 0-10 °C for 4 h. The reaction of the starting materials was monitored by TLC until the reaction was complete. Water was added, the mixture was filtered, and dried to obtain A-1.
[0040] Step 2: Synthesis of intermediate A2:
[0041] Add 0.1 mol of A-1 and 1000 ml of methanol to a three-necked flask, cool to 0-5℃, add 0.5 mol of tert-butyl nitrite and 1 mol of fluoroboric acid dropwise, and react for 2 h while maintaining the temperature. Add 0.1 mol of 1-naphthylamine, and react for 4 h while maintaining the temperature at 0-10℃. Monitor the reaction of the starting materials by TLC until the reaction is complete, add water, filter, recrystallize twice from ethanol, and dry to obtain A-2.
[0042] Step 3: Synthesis of intermediate A3:
[0043] Add 0.1 mol of A-2, 0.5 mol of hydrochloric acid, and 1000 ml of methanol to a three-necked flask, stir and cool to 0-5℃, add 0.2 mol of sodium nitrite aqueous solution dropwise, and react for 4 h while maintaining the temperature. Add 0.1 mol of N-isobutyl-1-naphthylamine, and react for 12 h while maintaining the temperature at 0-10℃. Monitor the reaction of the starting materials by TLC until the reaction is complete, add water, filter, and recrystallize three times with ethanol and toluene to obtain A-3.
[0044] Step 4: Preparation of compound I-1'
[0045] In a three-necked flask, 0.2 mol of alkylcyclohexylphenylboronic acid, 0.1 mol of A-3, 0.3 mol of potassium carbonate, and 2000 ml of THF were added. After purging with nitrogen, Pd catalyst was added, and the mixture was heated to reflux for 24 h. The reaction was monitored by TLC until the reactants were fully reacted. The mixture was then filtered with water, dissolved in 50 times the amount of toluene, and passed through a silica gel column. The toluene was recrystallized 4-5 times to obtain the product compound I-1'.
[0046] Example 2
[0047] This embodiment provides an azo blue dichroic dye compound and its preparation method.
[0048] In this embodiment, the azo blue dichroic dye compound I-2' has the structure shown in formula I-2':
[0049] Formula I-2',
[0050] R1 is n-pentyl.
[0051] The preparation method of the azo blue dichroic dye compound I-2' in this embodiment is as follows:
[0052] Step 1: Synthesis of intermediate A1:
[0053] 0.1 mol of 2-fluoro-4-bromoaniline, 0.12 mol of hydrochloric acid, and 1000 ml of methanol were added to a three-necked flask. The mixture was stirred and cooled to 0-5 °C. 0.1 mol of sodium nitrite aqueous solution was added dropwise. After the addition was complete, the temperature was controlled and the reaction was carried out for 4 h. 0.1 mol of 1-naphthylamine was added, and the temperature was controlled at 0-10 °C for 4 h. The reaction of the starting materials was monitored by TLC until it was complete. Water was added, the mixture was filtered, and dried to obtain A-1.
[0054] Step 2: Synthesis of intermediate A2:
[0055] Add 0.1 mol of A-1 and 1000 ml of methanol to a three-necked flask, cool to 0-5℃, add 0.5 mol of tert-butyl nitrite and 1 mol of fluoroboric acid dropwise, and react for 2 h while maintaining the temperature. Add 0.1 mol of 1-naphthylamine, and react for 4 h while maintaining the temperature at 0-10℃. Monitor the reaction of the starting materials by TLC until the reaction is complete, add water, filter, recrystallize twice from ethanol, and dry to obtain A-2.
[0056] Step 3: Synthesis of intermediate A3:
[0057] Add 0.1 mol of A-2, 0.5 mol of hydrochloric acid, and 1000 ml of methanol to a three-necked flask, stir and cool to 0-5℃, add 0.2 mol of sodium nitrite aqueous solution dropwise, and react for 4 h while maintaining the temperature. Add 0.1 mol of N-isopropyl-1-naphthylamine, and react for 12 h while maintaining the temperature at 0-10℃. Monitor the reaction of the starting materials by TLC until the reaction is complete, add water, filter, and recrystallize three times with ethanol and toluene to obtain A-3.
[0058] Step 4: Preparation of compound I-2'
[0059] In a three-necked flask, 0.2 mol of alkylcyclohexylphenylboronic acid, 0.1 mol of A-3, 0.3 mol of potassium carbonate, and 2000 ml of THF were added. After purging with nitrogen, Pd catalyst was added, and the mixture was heated to reflux for 24 h. The reaction was monitored by TLC until the reactants were fully reacted. The mixture was then filtered with water, dissolved in 50 times the amount of toluene, and passed through a silica gel column. The toluene was recrystallized 4-5 times to obtain the product compound I-2'.
[0060] Example 3
[0061] This embodiment provides an azo blue dichroic dye compound and its preparation method.
[0062] In this embodiment, the azo blue dichroic dye compound I-3' has the structure shown in formula I-3':
[0063] Formula I-3',
[0064] R1 is n-pentyl.
[0065] The preparation method of the azo blue dichroic dye compound I-3' in this embodiment is as follows:
[0066] Step 1: Synthesis of intermediate A1:
[0067] 0.1 mol of 2-fluoro-4-bromoaniline, 0.12 mol of hydrochloric acid, and 1000 ml of methanol were added to a three-necked flask. The mixture was stirred and cooled to 0-5 °C. 0.1 mol of sodium nitrite aqueous solution was added dropwise. After the addition was complete, the temperature was controlled and the reaction was carried out for 4 h. 0.1 mol of 1-naphthylamine was added, and the temperature was controlled at 0-10 °C for 4 h. The reaction of the starting materials was monitored by TLC until it was complete. Water was added, the mixture was filtered, and dried to obtain A-1.
[0068] Step 2: Synthesis of intermediate A2:
[0069] Add 0.1 mol of A-1 and 1000 ml of methanol to a three-necked flask, cool to 0-5℃, add 0.5 mol of tert-butyl nitrite and 1 mol of fluoroboric acid dropwise, and react for 2 h while maintaining the temperature. Add 0.1 mol of 1-naphthylamine, and react for 4 h while maintaining the temperature at 0-10℃. Monitor the reaction of the starting materials by TLC until the reaction is complete, add water, filter, recrystallize twice from ethanol, and dry to obtain A-2.
[0070] Step 3: Synthesis of intermediate A3:
[0071] Add 0.1 mol of A-2, 0.5 mol of hydrochloric acid, and 1000 ml of methanol to a three-necked flask, stir and cool to 0-5℃, add 0.2 mol of sodium nitrite aqueous solution dropwise, and react for 4 h while maintaining the temperature. Add 0.1 mol of N,N-diethyl-1-naphthylamine, and react for 12 h while maintaining the temperature at 0-10℃. Monitor the reaction of the starting materials by TLC until the reaction is complete, add water, filter, and recrystallize three times with ethanol and toluene to obtain A-3.
[0072] Step 4: Preparation of compound I-3':
[0073] In a three-necked flask, 0.2 mol of alkylcyclohexylphenylboronic acid, 0.1 mol of A-3, 0.3 mol of potassium carbonate, and 2000 ml of THF were added. After purging with nitrogen, Pd catalyst was added, and the mixture was heated to reflux for 24 h. The reaction was monitored by TLC until the reactants were fully reacted. The mixture was then filtered with water, dissolved in 50 times the amount of toluene, and passed through a silica gel column. The toluene was recrystallized 4-5 times to obtain the product compound I-3'.
[0074] Example 4
[0075] This embodiment provides an azo blue dichroic dye compound and its preparation method.
[0076] In this embodiment, the azo blue dichroic dye compound I-4' has the structure shown in formula I-4':
[0077] Formula I-4',
[0078] R1 is n-pentyl.
[0079] The preparation method of the azo blue dichroic dye compound I-4' in this embodiment is as follows:
[0080] Step 1: Synthesis of intermediate A1:
[0081] 0.1 mol of 2-methyl-4-bromoaniline, 0.12 mol of hydrochloric acid, and 1000 ml of methanol were added to a three-necked flask. The mixture was stirred and cooled to 0-5 °C. 0.1 mol of sodium nitrite aqueous solution was added dropwise. After the addition was complete, the temperature was controlled and the reaction was carried out for 4 h. 0.1 mol of 1-naphthylamine was added, and the temperature was controlled at 0-10 °C for 4 h. The reaction of the starting materials was monitored by TLC until the reaction was complete. Water was added, the mixture was filtered, and dried to obtain A-1.
[0082] Step 2: Synthesis of intermediate A2:
[0083] Add 0.1 mol of A-1 and 1000 ml of methanol to a three-necked flask, cool to 0-5℃, add 0.5 mol of tert-butyl nitrite and 1 mol of fluoroboric acid dropwise, and react for 2 h while maintaining the temperature. Add 0.1 mol of 1-naphthylamine, and react for 4 h while maintaining the temperature at 0-10℃. Monitor the reaction of the starting materials by TLC until the reaction is complete, add water, filter, recrystallize twice from ethanol, and dry to obtain A-2.
[0084] Step 3: Synthesis of intermediate A3:
[0085] Add 0.1 mol of A-2, 0.5 mol of hydrochloric acid, and 1000 ml of methanol to a three-necked flask, stir and cool to 0-5℃, add 0.2 mol of sodium nitrite aqueous solution dropwise, and react for 4 h while maintaining the temperature. Add 0.1 mol of N,N-diethyl-1-naphthylamine, and react for 12 h while maintaining the temperature at 0-10℃. Monitor the reaction of the starting materials by TLC until the reaction is complete, add water, filter, and recrystallize three times with ethanol and toluene to obtain A-3.
[0086] Step 4: Preparation of compound I-4'
[0087] In a three-necked flask, 0.2 mol of alkylcyclohexylphenylboronic acid, 0.1 mol of A-3, 0.3 mol of potassium carbonate, and 2000 ml of THF were added. After purging with nitrogen, Pd catalyst was added, and the mixture was heated to reflux for 24 h. The reaction was monitored by TLC until the reactants were fully reacted. The mixture was then filtered with water, dissolved in 50 times the amount of toluene, and passed through a silica gel column. The toluene was recrystallized 4-5 times to obtain the product compound I-4'.
[0088] Example 5
[0089] This embodiment provides an azo blue dichroic dye compound and its preparation method.
[0090] In this embodiment, the azo blue dichroic dye compound I-5' has the structure shown in formula I-5':
[0091] Formula I-5',
[0092] R1 is n-pentyl.
[0093] The preparation method of the azo blue dichroic dye compound I-5 in this embodiment is as follows:
[0094] Step 1: Synthesis of intermediate A1:
[0095] 0.1 mol of 2-methyl-4-bromoaniline, 0.12 mol of hydrochloric acid, and 1000 ml of methanol were added to a three-necked flask. The mixture was stirred and cooled to 0-5 °C. 0.1 mol of sodium nitrite aqueous solution was added dropwise. After the addition was complete, the temperature was controlled and the reaction was carried out for 4 h. 0.1 mol of 1-naphthylamine was added, and the temperature was controlled at 0-10 °C for 4 h. The reaction of the starting materials was monitored by TLC until the reaction was complete. Water was added, the mixture was filtered, and dried to obtain A-1.
[0096] Step 2: Synthesis of intermediate A2:
[0097] Add 0.1 mol of A-1 and 1000 ml of methanol to a three-necked flask, cool to 0-5℃, add 0.5 mol of tert-butyl nitrite and 1 mol of fluoroboric acid dropwise, and react for 2 h while maintaining the temperature. Add 0.1 mol of 1-naphthylamine, and react for 4 h while maintaining the temperature at 0-10℃. Monitor the reaction of the starting materials by TLC until the reaction is complete, add water, filter, recrystallize twice from ethanol, and dry to obtain A-2.
[0098] Step 3: Synthesis of intermediate A3:
[0099] Add 0.1 mol of A-2, 0.5 mol of hydrochloric acid, and 1000 ml of methanol to a three-necked flask, stir and cool to 0-5℃, add 0.2 mol of sodium nitrite aqueous solution dropwise, and react for 4 h while maintaining the temperature. Add 0.1 mol of N-isobutyl-1-naphthylamine, and react for 12 h while maintaining the temperature at 0-10℃. Monitor the reaction of the starting materials by TLC until the reaction is complete, add water, filter, and recrystallize three times with ethanol and toluene to obtain A-3.
[0100] Step 4: Preparation of compound I-5'
[0101] In a three-necked flask, 0.2 mol of alkylcyclohexylphenylboronic acid, 0.1 mol of A-3, 0.3 mol of potassium carbonate, and 2000 ml of THF were added. After purging with nitrogen, Pd catalyst was added, and the mixture was heated to reflux for 24 h. The reaction was monitored by TLC until the reactants were fully reacted. The mixture was then filtered with water, dissolved in 50 times the amount of toluene, and passed through a silica gel column. The toluene was recrystallized 4-5 times to obtain the product compound I-5'.
[0102] Example 6
[0103] In this embodiment, a liquid crystal mixture was prepared using the azo blue dichroic dye compound I-1' prepared in Example 1 as a raw material. All the liquid crystals in the mixture were commercial liquid crystal materials, and their chemical structural formulas and mass ratios are shown in Table 1.
[0104] Table 1
[0105]
[0106] Weigh the components according to the formulation ratio in Table 1, heat and stir to dissolve, and then filter to obtain the liquid crystal composition. Mix the liquid crystal composition with the azo blue dichroic dye compound I-1' prepared in Example 1 at a mass ratio of 100:3, filter, add to the liquid crystal cell, bake at 100°C for 24 hours, and then test the power consumption current.
[0107] Example 7
[0108] In this embodiment, a switching glass was prepared using the azo blue dichroic dye compound I-1' prepared in Example 5 as a raw material. The mixed liquid crystals were all commercial liquid crystal materials with the same chemical structure and formulation as in Example 6.
[0109] The polymer adhesives used in this embodiment are all commercial PDLC polymers. The specific material names and mass ratios are shown in Table 2.
[0110] Table 2
[0111]
[0112] Weigh the ingredients according to the formulation ratio in Table 2, stir and mix them evenly at room temperature, and then filter them through a 1μm filter membrane to obtain the resin composition.
[0113] The liquid crystal composition, the resin composition and the azo blue dichroic dye compound I-1' prepared in Example 1 were mixed at a mass ratio of 100:100:3. 15 μm microspheres were added and coated on a PET film coated with ITO. After being rolled in a roller press, the mixture was cured with a UV lamp. After curing, it was placed in an oven for high-temperature testing.
[0114] Comparative Example 1
[0115] This comparative example uses existing blue dichroic dye compounds as raw materials to prepare liquid crystal mixtures.
[0116] The only difference between this comparative example and Example 6 is that the blue dichroic dye compound I-1 in Example 6 is replaced with the dye compound shown in Formula I-0. The liquid crystal composition and the dye compound shown in Formula I-0 are mixed at a mass ratio of 100:3, filtered, added to the liquid crystal cell, and baked at 100°C for 24 hours before the power consumption current is tested.
[0117] Comparative Example 2
[0118] This comparative example uses existing blue dichroic dye compounds as raw materials to prepare dimming glass.
[0119] The only difference between this comparative example and Example 7 is that the blue dichroic dye compound I-1 in Example 7 is replaced with the dye compound shown in Formula I-0. The liquid crystal composition, resin composition and dye compound shown in Formula I-0 are mixed at a mass ratio of 100:100:3. 15μm microspheres are added and coated on a PET film coated with ITO. After being rolled in a roller press, it is cured with ultraviolet light using a UV lamp. After curing, it is placed in an oven for high-temperature testing.
[0120] The power consumption current of the liquid crystal mixtures in Example 6 and Comparative Example 1 is shown in Table 3.
[0121] Table 3
[0122]
[0123] As shown in Table 3, the liquid crystal mixture prepared using the azo blue dichroic dye compound I-1 provided by this invention in Example 6 had initial power consumption 1 and power consumption 2 of 0.92uA and 0.90uA, respectively, both lower than the initial power consumption (0.97uA and 0.98uA) of the existing dye compound I-0 used in Comparative Example 1. After baking at 100°C for 24 hours, the power consumption 1 and power consumption 2 of Example 6 were 0.97uA and 0.95uA, respectively, while those of Comparative Example 1 increased to 1.01uA and 1.01uA. This indicates that the azo blue dichroic dye compound of this invention has superior initial power consumption performance and high-temperature stability in liquid crystal mixtures. For energy-sensitive portable electronic devices and display systems that operate for extended periods, this low power consumption characteristic can effectively extend device battery life and reduce heat dissipation pressure. Simultaneously, the improved high-temperature stability means that the dye compound can maintain good performance even under harsh operating environments, reducing display abnormalities or shortened device lifespan caused by temperature changes, providing strong support for the application of liquid crystal display technology in a wider range of fields.
[0124] The high-temperature test results of the dimming glass in Example 7 and Comparative Example 2 are shown in Table 4.
[0125] Table 4
[0126]
[0127] As shown in Table 4, the dimming glass prepared using the azo blue dichroic dye compound I-1 of the present invention in Example 7 exhibited a transmittance change rate of 5.2% and a haze increase of 2.1% after high-temperature testing. In contrast, the dimming glass prepared using the existing dye compound I-0 in Comparative Example 2 showed a transmittance change rate of 12.8% and a haze increase of 6.7%. This indicates that the azo blue dichroic dye compound of the present invention has superior high-temperature stability in dimming glass applications, effectively suppressing the attenuation of transmittance and the increase of haze under high-temperature conditions. This characteristic allows the dimming glass to maintain more stable optical performance in scenarios such as building curtain walls and car sunroofs that are exposed to sunlight and high temperatures for extended periods, reducing uneven light transmission or blurred vision caused by material aging, and improving the durability and reliability of dimming products.
Claims
1. An azo blue dichroic dye compound, characterized in that, The compound has the structure shown in Formula I: Equation I; R1 and R4 are independently selected from saturated alkyl substituents of C1-C6, R2 represents -H, CH3 or -F, and R3 represents a hydrogen atom or a saturated alkyl substituent of C1-C6. R2 and R3 cannot both be hydrogen atoms.
2. The azo blue dichroic dye compound according to claim 1, characterized in that, The compound has the structure shown in Formula I-1 or Formula I-2: Formula I-1; Equation I-2; Among them, R1, R3, and R4 are C1-C6 saturated alkyl substituents.
3. The azo blue dichroic dye compound according to claim 1, characterized in that, The compound has the structure shown in Formula I-3 or Formula I-4: Formula I-3; Equation I-4; R1 and R4 are C1-C6 saturated alkyl substituents.
4. The azo blue dichroic dye compound according to claim 1, characterized in that, The compound has the structure shown in Formula I-5: Formula I-5; Among them, R1, R3, and R4 are C1-C6 saturated alkyl substituents.
5. An azo blue dichroic dye compound according to any one of claims 1-4, characterized in that, The saturated alkyl substituents of C1-C6 are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, sec-pentyl, tert-pentyl, n-hexyl, or neohexyl.
6. The use of an azo blue dichroic dye compound as described in any one of claims 1-5 in the preparation of liquid crystal display devices and dimming glass.
7. The application according to claim 6, characterized in that, The azo blue dichroic dye compound, alone or in combination with at least one commercial dichroic dye, is mixed with commercial single crystals or mixed crystals to obtain a liquid crystal mixture, which is used as a functional layer material to prepare the liquid crystal display device.
8. The application according to claim 7, characterized in that, The azo blue dichroic dye compound, alone or in combination with at least one commercial dichroic dye, is mixed with commercial single crystal or mixed crystal to obtain a liquid crystal mixture. The liquid crystal mixture is then mixed with acrylic resin to form an intelligent dimming functional system. After coating and photocuring, the functional system forms the core dimming layer of the dimming glass.