A blue active dye, its preparation method and application

Abstract

This invention provides a reactive indigo dye, its preparation method, and its applications. Using natural indigo as a single color-developing system and cyanuric chloride as a bridging backbone, a hydrophobic segment is introduced through a two-step condensation reaction to obtain a fat-soluble reactive indigo dye. This dye exhibits excellent solubility in non-polar organic solvents, oils, waxes, and polymeric substrates. The active chlorine atoms in the triazine group can form covalent bonds with the matrix, endowing the coloring system with excellent anti-migration properties, achieving non-fading, non-smudging, and long-lasting coloring. It can be used for coloring scented candles, oil-based inks, cosmetics, or engineering plastics. This invention effectively solves the technical bottlenecks of poor solubility of indigo in hydrophobic systems, easy discoloration under alkaline conditions, and high migration, demonstrating outstanding prospects for industrial application.

Description

Technical Field

[0001] This invention belongs to the field of fine chemicals and functional materials technology, and particularly relates to an indigo reactive dye, its preparation method and application. Background Technology

[0002] Blue violet is a naturally derived pyridone-based blue pigment with excellent photostability, a high molar extinction coefficient, and biodegradability, making it a key active component in next-generation green high-end colorants. However, the extremely strong hydrogen bonds and π-π stacking interactions between blue violet molecules make it difficult to dissolve in water and common organic solvents; furthermore, it is extremely sensitive to alkalis, easily undergoing irreversible oxidative degradation under alkaline conditions, causing its color to change from purplish-blue to brownish-red, severely limiting its chemical modification and industrial application.

[0003] Traditional reactive dyes are mostly designed as water-soluble systems, achieving aqueous dyeing by introducing strongly hydrophilic groups such as sulfonic acid groups, and are mainly used in natural fibers such as cotton and linen. However, with the increasing demand for fully bio-based and anti-migration colorants in the high-end consumer goods market, especially in hydrophobic matrices such as scented candles, oil-based inks, cosmetics, and engineering plastics, traditional water-soluble dyes are prone to problems such as precipitation, color spot aggregation, and poor migration resistance due to polarity mismatch.

[0004] Currently, research on the modification of styrax mainly focuses on physical blending or simple esterification / amidation. Physical blending is difficult to solve the long-term stability and migration problems of the pigment in hydrophobic media; while simple chemical modification often comes at the cost of sacrificing the stability of the chromophore or losing the activity of further reactions. For example, CN121405621A discloses a method for preparing N,N'-diacetyl-styrax, which uses a specific catalyst, an aluminum Lewis acid, to catalyze the acetylation reaction of styrax, so that the nitrogen atoms outside the two rings in styrax are fully acetylated. CN121160112A discloses a biological blue dye, dyeing solution, preparation method and application thereof. The biological blue dye includes indigo dye, pyridone dye, reducing agent and alkali agent. The mass fraction of indigo dye is 3-10 parts, and the mass fraction of pyridone dye is 0.1%-55% of the mass of indigo dye. By mixing pyridone dye into indigo dye, the blue light is adjusted to shift towards cyan light, reducing the red light effect. This can effectively solve the problems of reddish color and insufficient dyeing depth after dyeing indigo. Furthermore, with the increase of the mixing ratio of pyridone dye, a higher color depth can be obtained under the same dyeing concentration and number of passes. The dry and wet rubbing fastness of the dyed fabric is improved by 0.5 grades.

[0005] Therefore, developing a blue-based derivative that can retain the natural color of blue, possess excellent lipid solubility and chemical stability, and retain active reaction sites to achieve covalent fixation is a technical bottleneck that urgently needs to be solved in the field of bio-based dyes. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a blue reactive dye, its preparation method, and its application. The present invention uses natural blue as a single color-developing system and cyanuric chloride as a bridging framework. The molecule contains chlorine atoms, which can form covalent bonds with the matrix, and introduces hydrophobic segments to obtain a fat-soluble blue reactive dye. This gives the coloring system excellent anti-migration properties, achieving non-fading, non-smudging, and long-lasting coloring.

[0007] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides an indigo reactive dye having the following structure: ; Rn is selected from C4-C18 straight-chain or branched alkyl, C2-C4 alkenyl, C3-C6 cycloalkyl, C6-C20 aralkyl or alkoxy chains containing ether bonds.

[0008] This invention uses natural blue as a single color-producing system and cyanuric chloride as a bridging framework, introducing hydrophobic segments into the molecule to obtain a fat-soluble blue reactive dye. This dye has excellent solubility in non-polar organic solvents, oils, waxes and polymer substrates. The chlorine atoms in the triazine are retained in the molecule, which can covalently bond with the matrix surface containing hydroxyl, amino or thiol groups.

[0009] This invention significantly improves the solubility of natural pigments in non-polar media by modifying the structure of the blue dye molecule. The blue reactive dye is uniformly dispersed in an oily matrix. By utilizing the covalent bonding between the active groups and the matrix, it achieves excellent anti-migration properties, as well as non-bleeding and long-lasting coloring effects.

[0010] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The purpose and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0011] Preferably, the straight-chain or branched alkyl group of C4-C18 is selected from any one of n-butyl, isobutyl, n-pentyl, isopentyl, neopentyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, n-dodecyl, n-hexadecyl, or n-octadecyl.

[0012] The C4-C18 can be C4, C6, C8, C10, C12, C14, C16, or C18, etc.

[0013] Preferably, the C2-C4 alkenyl group is selected from any one of vinyl, propenyl, isopropenyl or butenyl, and the C2-C4 group can be C2, C3 or C4.

[0014] Preferably, the C3-C6 cycloalkyl group is selected from any one of cyclopropyl, cyclobutyl, cyclopentyl, or cyclohexyl, and the C3-C6 group can be C3, C4, C5, or C6.

[0015] Preferably, the C6-C20 aralkyl group is selected from any one of benzyl, phenethyl, phenylpropyl, diphenylmethyl or triphenylmethyl, and the C6-C20 can be C6, C8, C10, C12, C14, C16, C18 or C20, etc.

[0016] Preferably, the alkoxy chain containing the ether bond is selected from any one of methoxyethoxy, ethoxyethoxy, or methoxytriethoxy.

[0017] Preferably, the blue-reactive dye has the following structure: , , , , , , .

[0018] In a second aspect, the present invention provides a method for preparing indigo dye as described in the first aspect, the method comprising the following steps: (1) Rn-NH2 reacts with cyanuric chloride to give intermediate I; ; (2) Intermediate I reacts with blue to obtain the blue reactive dye; .

[0019] Rn has the same choices as described above.

[0020] In the present invention, steps (1)-(2) are maintained under anhydrous conditions throughout, and the extent of the two-step reaction is monitored by TLC.

[0021] Preferably, in step (1), the reaction is carried out in a solvent.

[0022] Preferably, the solvent includes acetone and / or toluene.

[0023] Preferably, in step (1), the reaction temperature is 0-5℃, for example, 0℃, 1℃, 2℃, 3℃, 4℃ or 5℃.

[0024] Preferably, in step (1), the reaction time is 2-4 hours, such as 2 hours, 3 hours or 4 hours.

[0025] Preferably, the molar ratio of Rn-NH2 to cyanuric chloride is (1-1.5):1, such as 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1 or 1.5:1.

[0026] Preferably, in step (2), the reaction temperature is 40-50℃, such as 40℃, 42℃, 44℃, 46℃, 48℃ or 50℃.

[0027] Preferably, in step (2), the reaction time is 4-8 hours, such as 4 hours, 5 hours, 6 hours, 7 hours or 8 hours.

[0028] Preferably, the molar ratio of intermediate I to blue is (2-3):1, such as 2:1, 2.2:1, 2.4:1, 2.6:1, 2.8:1 or 3:1, etc.

[0029] Preferably, the blue pigment reacts with intermediate I in the form of a blue pigment solution.

[0030] Preferably, the blue solution is obtained by dissolving blue in an aprotic polar solvent.

[0031] Preferably, the aprotic polar solvent includes dimethyl sulfoxide (DMSO) and / or N-methylpyrrolidone (NMP).

[0032] Preferably, in steps (1)-(2), the reaction is carried out in the presence of an acid-binding agent.

[0033] Preferably, the acid-binding agent comprises an organic base.

[0034] Preferably, the organic base includes triethylamine and / or N,N-diisopropylethylamine (DIPEA).

[0035] Preferably, in step (2), post-processing is further included after the reaction is completed.

[0036] Preferably, the post-processing includes precipitation, filtration, washing, and drying.

[0037] Preferably, the precipitation involves pouring the reacted mixture into ice-cold brine or cold water to precipitate a solid.

[0038] Preferably, the temperature of the ice-salt water and the cold water is independently 0-5℃, for example 0℃, 1℃, 2℃, 3℃, 4℃ or 5℃.

[0039] Preferably, the solvent used for washing includes water, ethanol, or petroleum ether.

[0040] Preferably, the temperature of the water and ethanol is independently 0-10°C, for example, 0°C, 2°C, 4°C, 6°C, 8°C, or 10°C.

[0041] Preferably, the drying includes vacuum drying.

[0042] Preferably, the drying temperature is ≤40℃, such as 15℃, 20℃, 25℃, 30℃, 35℃ or 40℃.

[0043] Thirdly, the present invention provides the application of the blue reactive dye as described in the first aspect or the blue reactive dye prepared according to the preparation method described in the second aspect in the coloring of hydrophobic systems.

[0044] Preferably, the application includes the coloring of scented candles, oil-based inks, cosmetics, or engineering plastics with blue reactive dyes.

[0045] The blue reactive dye of this invention can be dissolved in paraffin wax, soybean wax and beeswax in molecular form, with uniform color, no abnormal odor when ignited, and no precipitation or bleeding during long-term storage.

[0046] Compared with the prior art, the present invention has the following beneficial effects: The blue reactive dye of this invention combines high lipid solubility with high reactivity. By utilizing triazine rings to bridge hydrophobic segments, it significantly improves the solubility of natural pigments in non-polar media while retaining active chlorine atoms, achieving covalent bonding and durable coloring of natural dyes in hydrophobic matrices. The blue reactive dye has excellent anti-migration properties, disperses uniformly in oily matrices, and achieves zero migration and non-bleeding coloring effects, solving the defect of easy precipitation in traditional dyes.

[0047] This invention prepares a blue reactive dye through a two-step condensation reaction, with a purity ≥88% and a yield ≥69%. After coloring a candle with this blue reactive dye, the color difference between the surface and the center is minimal, ΔE≤0.8. No dye seepage occurs when the candle is stored at 40℃ for 30 days, and no blue transfer occurs after 72 hours of contact with filter paper. Attached Figure Description

[0048] Figure 1 The liquid phase diagram is shown for the blue reactive dye prepared in Example 1. Figure 2 The UV-Vis absorption spectrum of the blue reactive dye prepared in Example 1 is shown below. Figure 3 The mass spectrum of the blue reactive dye prepared in Example 1 is shown below. Figure 4 The liquid phase diagram is shown for the blue reactive dye prepared in Example 3. Figure 5 The UV-Vis absorption spectrum of the blue reactive dye prepared in Example 3 is shown below. Figure 6 The mass spectrum of the blue reactive dye prepared in Example 3 is shown below. Figure 7 This is an image of the appearance of the aqueous solution of the blue reactive dye in Example 4. Detailed Implementation

[0049] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0050] In the following examples, unless otherwise specified, the experimental methods used are conventional methods, and the materials and reagents used are commercially available, and the raw materials used in each parallel experiment are the same. The indigo naturalis raw material used in the following examples was provided by Nanjing Hegu Life Biotechnology Co., Ltd.

[0051] The purity of the product was determined by high-performance liquid chromatography (HPLC), as follows: Chromatographic conditions: Mobile phase: Gradient elution of methanol and pure water, the gradients are shown in Table 1: Table 1 Wavelength 600 nm, flow rate 1.0 mL / min, sample solution: DMSO, injection volume: 10 μL, column temperature 35 ℃, run time 20 min, column: Galasil EF-C18M 4.6 mmid × 250 mmL (SN B06211801).

[0052] Example 1 This embodiment provides a blue reactive dye (N-butyl-2-amino-4,6-dichloro-1,3,5-triazine) and its preparation method. The synthetic route is shown below, and the preparation method includes the following steps: (1) In a 500 mL four-necked flask equipped with a mechanical stirrer, a constant pressure dropping funnel and a thermometer, add cyanuric chloride (55.2 g, 0.3 mol) and anhydrous acetone (500 mL) and cool to 0-5 °C in an ice-salt bath; dissolve n-butylamine (32.7 g, 0.45 mol) in anhydrous acetone (120 mL) and slowly drop it into the reaction flask (the molar ratio of cyanuric chloride to n-butylamine is 1:1.5), while adding triethylamine (45.5 g, 0.45 mol) dropwise. After the addition is complete, keep the reaction at 0-5 °C for 2 h under nitrogen protection. Monitor the reaction by TLC until the cyanuric chloride spots completely disappear to obtain intermediate I-1. (2) Dissolve 37.2 g, 0.15 mol of lanthanum in anhydrous NMP (400 mL), add the reaction solution from step (1) (the molar ratio of lanthanum to intermediate I-1 is 1:2), and heat to 40 °C; dissolve 30.3 g, 0.3 mol of triethylamine in NMP (50 mL), slowly add it dropwise to the reaction system, and after the addition is complete, keep the reaction under nitrogen protection for 8 h; (3) Pour the reaction solution from step (2) into 10°C cold water (1500mL), precipitate, let stand for 30min, filter, wash the filter cake with 10°C pure water (3×200mL), and vacuum dry at 40°C to constant weight to obtain product I, 73.95g of purple-red powder, yield 74.5% (based on blue color).

[0053] The present invention tested the liquid phase diagram of product I, as shown below. Figure 1 As shown, the elution time is 14.5 min, and the UV-Vis absorption spectrum is as follows. Figure 2 As shown, the maximum absorption wavelength is 542 nm.

[0054] The present invention tested the mass spectrometry of product I, such as... Figure 3 As shown, [M+H] + The measured m / z value of the ion peak is 617.23, which is consistent with the molecular formula C. 24 H 26 O4Cl2N 12 The value matches the theoretical value, thus determining the molecular weight of the compound to be 616.16.

[0055] Example 2 This embodiment provides a blue reactive dye (N-butyl-2-amino-4,6-dichloro-1,3,5-triazine) and its preparation method, the preparation method comprising the following steps: (1) In a 500 mL four-necked flask equipped with a mechanical stirrer, a constant pressure dropping funnel and a thermometer, add cyanuric chloride (55.2 g, 0.3 mol) and anhydrous acetone (500 mL) and cool to 0-5 °C in an ice-salt bath; dissolve n-butylamine (32.7 g, 0.45 mol) in anhydrous acetone (120 mL) and slowly drop it into the reaction flask (the molar ratio of cyanuric chloride to n-butylamine is 1:1.5), while simultaneously adding DIPEA (58.2 g, 0.45 mol). After the addition is complete, keep the reaction at 0-5 °C for 4 h under nitrogen protection. Monitor the reaction by TLC until the cyanuric chloride spots completely disappear to obtain intermediate I-1. (2) Dissolve 31.0 g, 0.125 mol of styrax in DMSO (400 mL), add the reaction solution from step (1) (the molar ratio of styrax to intermediate I-1 is 1:2.4), and heat to 45 °C; dissolve 46.5 g, 0.36 mol of DIPEA in DMSO (50 mL), slowly add it dropwise to the reaction system, and after the addition is complete, keep the reaction under nitrogen protection for 6 h. (3) Pour the reaction solution from step (2) into 5℃ cold water (1500mL), precipitate, let stand for 30min, filter, wash the filter cake with 5℃ pure water (3×200mL), and vacuum dry at 35℃ to constant weight to obtain product I, 62.47g of purple-red powder, yield 76.0% (based on blue color).

[0056] Example 3 This embodiment provides a blue reactive dye (N-octyl-2-amino-4,6-dichloro-1,3,5-triazine) and its preparation method. The synthetic route is shown below, and the preparation method includes the following steps: (1) In a 500 mL four-necked flask equipped with a mechanical stirrer, a constant pressure dropping funnel and a thermometer, add cyanuric chloride (55.2 g, 0.3 mol) and anhydrous acetone (500 mL) and cool to 0-5 °C in an ice-salt bath; dissolve n-octylamine (38.7 g, 0.3 mol) in anhydrous acetone (120 mL) and slowly drop it into the reaction flask (the molar ratio of cyanuric chloride to n-octylamine is 1:1), while adding triethylamine (30.3 g, 0.3 mol) dropwise. After the addition is complete, keep the reaction at 0-5 °C for 4 h under nitrogen protection. Monitor the reaction by TLC until the cyanuric chloride spots completely disappear to obtain intermediate I-2. (2) Dissolve 37.2 g, 0.15 mol of styrax in DMSO (400 mL), add the reaction solution from step (1) (the molar ratio of styrax to intermediate I is 1:2.0), and heat to 45 °C; dissolve 30.3 g, 0.3 mol of triethylamine in DMSO (50 mL), slowly add it dropwise to the reaction system, and after the addition is complete, keep the reaction under nitrogen protection for 6 h. (3) Pour the reaction solution from step (2) into 0℃ ice-salt water (1500mL), precipitate, let stand for 30min, filter, wash the filter cake with 0℃ pure water (3×200mL), and dry under vacuum at 35℃ to constant weight to obtain product II, 91.00g of purple-red powder, yield 79.3% (based on blue color).

[0057] The present invention tested the liquid phase diagram of intermediate I-2, as follows: Figure 4 As shown, the peak elution time is 14.7 min, and the UV-Vis absorption spectrum is as follows. Figure 5 As shown, the maximum absorption wavelength is 541 nm.

[0058] The present invention tested the mass spectrometry of product II, such as... Figure 6 As shown, [MH] - The measured m / z value of the ion peak is 727.20, which is consistent with the molecular formula C. 32 H 42 O4Cl2N 12 The value matches the theoretical value, thus determining the molecular weight of the compound to be 728.28.

[0059] Example 4 This embodiment provides a blue reactive dye (N-octyl-2-amino-4,6-dichloro-1,3,5-triazine) and its preparation method, the preparation method comprising the following steps: (1) In a 500 mL four-necked flask equipped with a mechanical stirrer, a constant pressure dropping funnel and a thermometer, add cyanuric chloride (55.2 g, 0.3 mol) and anhydrous acetone (500 mL) and cool to 0-5 °C in an ice-salt bath; dissolve n-octylamine (58.1 g, 0.45 mol) in anhydrous acetone (120 mL) and slowly drop it into the reaction flask (the molar ratio of cyanuric chloride to n-octylamine is 1:1.5), while simultaneously adding DIPEA (58.2 g, 0.45 mol). After the addition is complete, keep the reaction at 0-5 °C for 3 h under nitrogen protection. Monitor the reaction by TLC until the cyanuric chloride spots completely disappear to obtain intermediate I-2. (2) Dissolve 24.8 g, 0.1 mol of styrax in NMP (400 mL), add the reaction solution from step (1) (the molar ratio of styrax to intermediate I-2 is 1:3.0), and heat to 50 °C; dissolve 58.2 g, 0.45 mol of DIPEA in NMP (50 mL), slowly add it dropwise to the reaction system, and after the addition is complete, keep the reaction under nitrogen protection for 5 h. (3) Pour the reaction solution from step (2) into 0℃ ice-salt water (1500mL), precipitate, let stand for 30min, filter, wash the filter cake with 0℃ pure water (3×200mL), and vacuum dry at 30℃ to constant weight to obtain product II, 63.24g of purple-red powder, yield 83.8% (based on blue color).

[0060] Figure 6 The aqueous solution of the blue reactive dye prepared in Example 4 has a full and uniform color.

[0061] Example 5 This embodiment provides a blue reactive dye (N-octyl-2-amino-4,6-dichloro-1,3,5-triazine) and its preparation method, the preparation method comprising the following steps: (1) In a 500 mL four-necked flask equipped with a mechanical stirrer, a constant pressure dropping funnel, and a thermometer, add cyanuric chloride (55.2 g, 0.3 mol) and anhydrous acetone (500 mL), and cool to 0-5 °C in an ice-salt bath; dissolve n-octylamine (48.4 g, 0.375 mol) in anhydrous acetone (120 mL) and slowly drop it into the reaction flask (the molar ratio of cyanuric chloride to n-octylamine is 1:1.125), and simultaneously add triethylamine (38.0 g, 0.375 mol). After the addition is complete, keep the reaction at 0-5 °C for 3.5 h under nitrogen protection. Monitor the reaction by TLC until the cyanuric chloride spots completely disappear, and obtain intermediate I-2; (2) Dissolve 29.8 g, 0.12 mol of styrax in DMSO (400 mL), add the reaction solution from step (1) (the molar ratio of styrax to intermediate I-2 is 1:2.5), and heat to 45 °C; dissolve 38.0 g, 0.375 mol of triethylamine in DMSO (50 mL), slowly add it dropwise to the reaction system, and after the addition is complete, keep the reaction under nitrogen protection for 6 h; (3) Pour the reaction solution from step (2) into 5°C cold water (1500mL), precipitate, let stand for 30min, filter, wash the filter cake with 5°C pure water (3×200mL), and dry it under vacuum at 35°C to constant weight to obtain product II, 74.90g of purple-red powder, yield 81.5% (based on blue color).

[0062] Example 6 This embodiment provides a blue reactive dye (N-octadecyl-2-amino-4,6-dichloro-1,3,5-triazine) and its preparation method. The synthetic route is shown below, and the preparation method includes the following steps: (1) In a 500 mL four-necked flask equipped with a mechanical stirrer, a constant pressure dropping funnel, and a thermometer, add cyanuric chloride (55.2 g, 0.3 mol), anhydrous acetone and toluene (volume ratio 2:1, total 500 mL), and cool to 0-5 °C in an ice-salt bath; dissolve n-octadecylamine (80.8 g, 0.3 mol) in toluene (200 mL) and slowly drop it into the reaction flask (the molar ratio of cyanuric chloride to n-octadecylamine is 1:1), while simultaneously adding triethylamine (30.3 g, 0.3 mol). After the addition is complete, keep the reaction at 0-5 °C for 4 h under nitrogen protection. Monitor the reaction by TLC until the cyanuric chloride spots completely disappear, and obtain intermediate I-3; (2) Dissolve 37.2 g, 0.15 mol of styrax in DMSO (400 mL), add the reaction solution from step (1) (the molar ratio of styrax to intermediate I-3 is 1:2.0), and heat to 45 °C; dissolve 30.3 g, 0.3 mol of triethylamine in DMSO (50 mL), slowly add it dropwise to the reaction system, and after the addition is complete, keep the reaction under nitrogen protection for 6 h; (3) Pour the reaction solution from step (2) into 10°C cold water (1500mL), precipitate, let stand for 30min, filter, wash the filter cake with 10°C pure water (3×200mL), and dry under vacuum at 40°C to constant weight to obtain product III, 121.88g of dark blue waxy powder, yield 71.2% (based on blue color).

[0063] The mass spectrometry data for product III are: [M+H] + The measured m / z value of the ion peak is 1009.61, which is consistent with the molecular formula C. 52 H 82 O4Cl2N 12 The value matches the theoretical value, thus determining the molecular weight of the compound to be 1008.60.

[0064] Example 7 This embodiment provides a blue reactive dye (N-octadecyl-2-amino-4,6-dichloro-1,3,5-triazine) and its preparation method, the preparation method comprising the following steps: (1) In a 500 mL four-necked flask equipped with a mechanical stirrer, a constant pressure dropping funnel, and a thermometer, add cyanuric chloride (55.2 g, 0.3 mol), anhydrous acetone and toluene mixed solvent (volume ratio 2:1, total 500 mL), and cool to 0-5 °C in an ice-salt bath; dissolve n-octadecylamine (121.2 g, 0.45 mol) in toluene (250 mL) and slowly drop it into the reaction flask (the molar ratio of cyanuric chloride to n-octadecylamine is 1:1.5), while simultaneously adding DIPEA (58.2 g, 0.45 mol). After the addition is complete, keep the reaction at 0-5 °C for 4 h under nitrogen protection. Monitor the reaction by TLC until the cyanuric chloride spots completely disappear, and obtain intermediate I-3; (2) Dissolve 24.8 g, 0.1 mol of styrax in NMP (450 mL), add the reaction solution from step (1) (the molar ratio of styrax to intermediate I-3 is 1:3.0), and heat to 50 °C; dissolve 77.6 g, 0.6 mol of DIPEA in NMP (60 mL), slowly add it dropwise to the reaction system, and after the addition is complete, keep the reaction under nitrogen protection for 6 h. (3) Pour the reaction solution from step (2) into 5°C cold water (1500mL), precipitate, let stand for 30min, filter, wash the filter cake with 5°C pure water (3×200mL), and vacuum dry at 30°C to constant weight to obtain product III, 87.17g of dark blue waxy powder, yield 78.8% (based on blue color).

[0065] Example 8 This embodiment provides a blue reactive dye (N-octadecyl-2-amino-4,6-dichloro-1,3,5-triazine) and its preparation method, the preparation method comprising the following steps: (1) In a 500 mL four-necked flask equipped with a mechanical stirrer, a constant pressure dropping funnel, and a thermometer, add cyanuric chloride (55.2 g, 0.3 mol), anhydrous acetone and toluene mixed solvent (volume ratio 2:1, total 500 mL), and cool to 0-5 °C in an ice-salt bath; dissolve n-octadecylamine (107.8 g, 0.4 mol) in toluene (220 mL) and slowly drop it into the reaction flask (the molar ratio of cyanuric chloride to n-octadecylamine is 1:1.33), while simultaneously adding triethylamine (40.4 g, 0.4 mol). After the addition is complete, keep the reaction at 0-5 °C for 3.5 h under nitrogen protection. Monitor the reaction by TLC until the cyanuric chloride spots completely disappear, and obtain intermediate I-3; (2) Dissolve 29.8 g, 0.12 mol of styrax in DMSO (450 mL), add the reaction solution from step (1) (the molar ratio of styrax to intermediate I-3 is 1:2.5), and heat to 48 °C; dissolve 45.5 g, 0.45 mol of triethylamine in DMSO (50 mL), slowly add it dropwise to the reaction system, and after the addition is complete, keep the reaction under nitrogen protection for 7 h; (3) Pour the reaction solution from step (2) into 0℃ ice-salt water (1500mL), precipitate, let stand for 30min, filter, wash the filter cake with 0℃ pure water (3×200mL), and dry under vacuum at 35℃ to constant weight to obtain product III, 100.46g of dark blue waxy powder, yield 75.1% (based on blue color).

[0066] Example 9 The only difference from Example 1 is that n-butylamine in Example 1 was replaced with an equimolar amount of cyclohexylamine. The preparation method is the same as in Example 1, and the synthetic route is shown below. Product IV was obtained, 80.20 g, yield 74.8% (based on blue color). The mass spectrometry data for product IV are: [M+H] + The measured m / z value of the ion peak is 669.22, which is consistent with the molecular formula C. 28 H 30 O4Cl2N 12 The value matches the theoretical value, thus determining the molecular weight of the compound to be 668.19.

[0067] Example 10 The only difference from Example 1 is that n-butylamine in Example 1 is replaced with an equimolar amount of oleylamine. The preparation method is the same as in Example 1, and the synthetic route is shown below. Product V was obtained, 93.50 g, yield 70.5% (based on blue color). The mass spectrometry data for product V are: [M+H] +The measured m / z value of the ion peak was 781.55, which is consistent with the molecular formula C. 36 H 46 O4Cl2N 12 The value matches the theoretical value, thus determining the molecular weight of the compound to be 780.31.

[0068] Example 11 The only difference from Example 1 is that n-butylamine in Example 1 was replaced with an equimolar amount of benzylamine. The preparation method is the same as in Example 1, and the synthetic route is shown below. Product VI was obtained, 78.51 g, yield 69.5% (based on blue color). The mass spectrometry data for product VI are: [M+H] + The measured m / z value of the ion peak is 685.31, which is consistent with the molecular formula C. 30 H 22 O4Cl2N 12 The value matches the theoretical value, thus determining the molecular weight of the compound to be 684.13.

[0069] Example 12 The only difference from Example 1 is that n-butylamine in Example 1 was replaced with an equimolar amount of 2-(2-methoxyethoxy)ethylamine. The preparation method is the same as in Example 1, and the synthetic route is shown below. Product VII was obtained, 83.56 g, yield 72.6% (based on blue color). The mass spectrometry data for product VII are: [M+H] + The measured m / z value of the ion peak was 709.43, which is consistent with the molecular formula C. 26 H 30 O8Cl2N 12 The value matches the theoretical value, thus determining the molecular weight of the compound to be 708.17.

[0070] Example 13 The only difference from Example 1 is that in step (1), n-butylamine (21.8g, 0.24mol) (the molar ratio of cyanuric chloride to n-butylamine is 1:0.8) is used for the reaction at 0-5℃ for 4h, and the amount of other components and the preparation method are the same as in Example 1.

[0071] TLC monitoring (developing solvent: petroleum ether to ethyl acetate, volume ratio 5:1) showed that: after 4 hours of reaction in step (1), the cyanuric chloride raw material spot (R f ≈0.7) was still clearly visible. After adding n-butylamine to bring the molar ratio of cyanuric chloride to n-butylamine to 1:1.2, the reaction continued for 2 hours, but the raw material residue could not be completely eliminated. After 8 hours of reaction in step (2), TLC showed blue raw material spots (R f≈0.3) Large amount of residue, target product spot (R f The color was pale (≈0.5). A final yield of 60.62 g of purplish-red powder was obtained, with a yield of 52.6% (based on blue color). TLC showed the presence of unreacted blue spots and more polar polysubstituted byproduct spots.

[0072] Example 14 The only difference from Example 4 is that in step (1), n-octylamine (77.4 g, 0.6 mol) (the molar ratio of cyanuric chloride to n-octylamine is 1:2) is dissolved in anhydrous acetone (150 mL), and triethylamine (60.6 g, 0.6 mol) is added dropwise; the amounts of the remaining components and the preparation methods are the same as in Example 4.

[0073] Step (1) The reaction solution was monitored by TLC, which showed that, except for the target intermediate I-2 (R f In addition to approximately 0.6), spots of disubstituted cyanuric chloride byproducts with even lower polarity (R) appeared. f ≈0.8), indicating that the excess of primary amine led to the di-substitution reaction. After step (2), 65.16 g of purple-red powder was obtained, with a yield of 76.5%. The product was separated by silica gel column chromatography (eluent: petroleum ether and ethyl acetate in a volume ratio of 8:1 to 4:1), and the bis-gold-substituted triazine byproduct was obtained. , (R f (≈0.3), content 12.3%.

[0074] Example 15 The only difference from Example 3 is that in step (2), 32.24 g, 0.13 mol of lanthanum was dissolved in DMSO (400 mL) and added to 2 / 3 of the volume of the reaction solution in step (1) (calculated based on 0.2 mol of intermediate I-2) (the molar ratio of lanthanum to intermediate I-2 is 1:1.5); 20.2 g, 0.2 mol of triethylamine was dissolved in DMSO (35 mL) and reacted for 8 h. The amounts and preparation methods of the remaining components were the same as in Example 3.

[0075] After 8 hours of reaction in step (2), TLC monitoring showed blue spots on the raw material (R). f ≈0.3) is still clearly visible, and the target product spot (R) is still clearly visible. f With a strength of ≈0.5, the reaction was extended to 12 hours, and the conversion rate of the blue pigment was 62%. Finally, 76.60 g of purple-red powder was obtained, with a yield of 58.7% (based on the blue pigment).

[0076] Example 16 The only difference from Example 7 is that in step (2), 297.6 g, 1.2 mol of lanthanum was dissolved in NMP (450 mL) and added to the reaction solution of step (1) (the molar ratio of lanthanum to intermediate I-3 is 1:4, calculated based on cyanuric chloride feed). The amount of other components and the preparation method are the same as in Example 7.

[0077] 100.13 g of a deep blue waxy powder was obtained, with a yield of 80.1% (based on the blue pigment). HPLC analysis (C18 column, acetonitrile to water volume ratio of 95:5) showed that the main peak (retention time 8.2 min) of the product had an area of ​​82.3%, and the byproduct peak (retention time 7.1 min) had an area of ​​9.8%. Mass spectrometry identification confirmed it to be a bis-blue substituted triazine byproduct. The product was dissolved in paraffin (1 g / L) and the color was measured: Δb*=-2.8, which is more greenish than that of Example 7 (Δb*=-1.9), indicating that the byproduct caused the color shift.

[0078] Example 17 The only difference from Example 2 is that in step (1), the mixture is cooled to 10-15°C in an ice-water bath and kept warm for 2 hours. The amount of other components and the preparation method are the same as in Example 2.

[0079] Step (1) TLC of the reaction solution showed: except for intermediate I-1 (R f In addition to ≈0.6), spots with significantly increased polarity (R) appeared. f ≈0.1), and was confirmed to be a hydrolysis product of cyanuric chloride (2-hydroxy-4,6-dichloro-1,3,5-triazine) after comparison with the standard. After the reaction in step (2), 56.4 g of purple-red powder was obtained, with a yield of 61.2%. Chlorine element analysis of the product (oxygen flask combustion-ion chromatography): active chlorine content 4.82% (theoretical value 5.83%), active chlorine retention rate 82.7%, which is 15.6 percentage points lower than that in Example 2 (active chlorine retention rate 98.3%).

[0080] Example 18 The only difference from Example 5 is that in step (2), the temperature is raised to 30°C and the reaction is kept at that temperature for 16 hours. The amount of other components and the preparation method are the same as in Example 5.

[0081] Step (2): After 8 hours of reaction, samples were taken for TLC monitoring to observe the blue raw material spots (R). f The sample size (≈0.3) was still significantly stronger than the target product spot (R). f ≈0.5); after 16 hours of reaction, 40% of the blue pigment remained (TLC area normalization method). Finally, 56.90 g of purplish-red powder was obtained, with a yield of 52.8% (based on blue pigment).

[0082] Example 19 The only difference from Example 1 is that in step (2), blue azurite (37.2g, 0.15mol) is dissolved in anhydrous ethanol (400mL), dispersed by ultrasonication, and in a suspended state. Triethylamine (30.3g, 0.3mol) is dissolved in anhydrous ethanol (50mL). The amounts and preparation methods of the remaining components are the same as in Example 1.

[0083] In step (2), after adding the reaction solution from step (1) to the blue pigment, a large amount of white flocculent precipitate immediately precipitated in the reaction system. After separation and identification, it was determined to be the alcoholysis / hydrolysis product of intermediate I-1 (FT-IR: 3400 cm⁻¹). -1 Broad peak, -OH / -NH; 1200 cm⁻¹ -1 (COC). After 8 hours of reaction, the reaction solution turned deep blue but was severely turbid, making filtration difficult. Finally, 42.61 g of a purplish-red powder was obtained, with a yield of 32.5% (based on the appearance of blue). FT-IR of the product showed the characteristic C-Cl peak on the triazine ring (850 cm⁻¹). -1 The intensity decreased significantly, and the characteristic peak of COC (1100 cm⁻¹) appeared. -1 ).

[0084] Example 20 The only difference from Example 3 is that in step (3), the filter cake is washed with 25°C pure water (3×200mL), and the amount of other components and the preparation method are the same as in Example 3.

[0085] During the washing process, the filtrate turned a distinct blue, indicating that the active dye, Spectrum Blue, has a certain solubility in water at 25°C, resulting in product loss. 82.57 g of a purplish-red powder was obtained, with a yield of 68.4% (based on Spectrum Blue).

[0086] Example 21 The only difference from Example 1 is that in step (1), the reaction time is 6 hours, and the amount of other components and the preparation method are the same as in Example 1, yielding 82.58 g of purple-red powder with a yield of 75.5% (based on blue color).

[0087] The purity and yield of the blue reactive dye in the embodiments of the present invention are shown in Table 2. The purity and yield of the obtained blue reactive dye were tested by high performance liquid chromatography.

[0088] Table 2 By precisely controlling the material ratio, reaction conditions, and solvent type, the blue reactive dyes prepared in Examples 1-12 of this invention have high purity (≥88%) and yield (≥69%). The preparation method is mild and easy to operate.

[0089] In Example 13, the molar ratio of cyanuric chloride to n-butylamine in step (1) was too low, at 1:0.8, which prevented the complete conversion of cyanuric chloride. This resulted in insufficient intermediate I-1 in step (2), low conversion rate of cyanuric chloride, and a significant decrease in yield. In Example 14, the molar ratio of cyanuric chloride to n-octylamine in step (1) was too high, at 1:2, which significantly increased side reactions, decreased the yield of the target product, and reduced its purity.

[0090] In Example 15, the molar ratio of styrax to intermediate I-2 in step (2) was too high, resulting in incomplete conversion of styrax and a significant decrease in yield. In Example 16, the molar ratio of styrax to intermediate I-3 in step (2) was too low, leading to a significant increase in disubstituted side reactions of styrax, a decrease in product purity, and impaired color stability.

[0091] In Example 17, step (1) was too high, which led to significant hydrolysis side reactions of cyanuric chloride, resulting in a decrease in the retention rate of active chlorine in the product and a reduction in yield. In Example 18, step (2) was too low, resulting in an extremely slow reaction rate. Even with extended reaction time, complete conversion of cyanuric chloride could not be achieved.

[0092] In Example 19, the reaction was carried out in a protic solvent. The active chlorine in intermediate I-1 underwent rapid solvation / hydrolysis, making it unable to react effectively with the blue pigment.

[0093] In Example 20, the filtrate was distinctly blue during the post-treatment washing process, indicating that the active ingredient in the blue filtrate has a certain solubility in water at 25°C, resulting in product loss. Therefore, washing needs to be carried out in cold water.

[0094] In Example 21, the reaction time in step (1) was too long, which led to the decomposition of the reaction product in step (1), resulting in a decrease in purity and yield.

[0095] Application examples This invention provides an application of indigo reactive dye in candle dyeing.

[0096] Materials and formulation: 500g wax base (hard jelly wax for aromatherapy), 0.1g of blue reactive dye (purity 96.5%, yield 83.8%) prepared in Example 4 (accounting for 0.02% of the wax base mass).

[0097] Preparation process: (1) Wax base melting: Add hard jelly wax to the wax melting kettle, heat to 75-80℃, and stir until completely transparent and molten; (2) Dye pre-dispersion: Take 0.1g of blue reactive dye and slowly add it to the molten wax liquid, stir for 15min to make it evenly dispersed; (3) Pouring: Cool down to 65°C and pour the wax liquid into the glass candle cup where the wick is placed beforehand; (4) Cooling and curing: Let stand at room temperature for 24 hours until the candle is completely cured to obtain the finished dyeing wax.

[0098] Comparative application examples The only difference from the application example is that the active dye is replaced with an equal amount of unmodified indigo powder (particle size ≤10μm), and everything else is the same as the application example.

[0099] Performance testing (1) Solubility and color uniformity: The appearance of the cured candle was observed with the naked eye, and the color difference ΔE of the surface and center of the candle was measured using a colorimeter (Konica Minolta CM-5); (2) Anti-migration test: The candle was placed in a constant temperature incubator at 40℃ for 30 days, and the surface of the candle and the inner wall of the candle cup were observed every 5 days to see if there was any dye seepage or precipitation; at the same time, the candle was brought into contact with white filter paper (contact pressure 50g / cm). 2 After 72 hours, observe whether the filter paper is stained.

[0100] The test results are shown in Table 3: Table 3 The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A blue-reactive dye, characterized in that, The indigo reactive dye has the following structure: ； Rn is selected from C4-C18 straight-chain or branched alkyl, C2-C4 alkenyl, C3-C6 cycloalkyl, C6-C20 aralkyl or alkoxy chains containing ether bonds.

2. The blue-reactive dye according to claim 1, characterized in that, The C4-C18 straight-chain or branched alkyl group is selected from any one of n-butyl, isobutyl, n-pentyl, isopentyl, neopentyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, n-dodecyl, n-hexadecyl, or n-octadecyl. Preferably, the C2-C4 alkenyl group is selected from any one of vinyl, propenyl, isopropenyl, or butenyl groups; Preferably, the C3-C6 cycloalkyl group is selected from any one of cyclopropyl, cyclobutyl, cyclopentyl, or cyclohexyl; Preferably, the C6-C20 aralkyl group is selected from any one of benzyl, phenethyl, phenylpropyl, diphenylmethyl, or triphenylmethyl; Preferably, the alkoxy chain containing the ether bond is selected from any one of methoxyethoxy, ethoxyethoxy, or methoxytriethoxy.

3. The blue-reactive dye according to claim 1 or 2, characterized in that, The indigo reactive dye has the following structure: 、 、 、 、 、 、 。 4. A method for preparing an indigo reactive dye as described in any one of claims 1-3, characterized in that, The preparation method includes the following steps: (1) Rn-NH2 reacts with cyanuric chloride to give intermediate I; ； (2) Intermediate I reacts with blue to obtain the blue reactive dye; ； Rn has the same choice as in claim 1.

5. The preparation method according to claim 4, characterized in that, In step (1), the reaction is carried out in a solvent; Preferably, the solvent includes acetone and / or toluene; Preferably, in step (1), the reaction temperature is 0-5℃; Preferably, in step (1), the reaction time is 2-4 hours; Preferably, the molar ratio of Rn-NH2 to cyanuric chloride is (1-1.5):

1.

6. The preparation method according to claim 4 or 5, characterized in that, In step (2), the reaction temperature is 40-50℃; Preferably, in step (2), the reaction time is 4-8 hours; Preferably, the molar ratio of intermediate I to blue is 1:(2-3); Preferably, the blue pigment reacts with intermediate I in the form of a blue pigment solution; Preferably, the blue violet solution is obtained by dissolving blue violet in an aprotic polar solvent; Preferably, the aprotic polar solvent includes dimethyl sulfoxide and / or N-methylpyrrolidone.

7. The preparation method according to any one of claims 4-6, characterized in that, In steps (1)-(2), the reaction is carried out in the presence of an acid-binding agent; Preferably, the acid-binding agent comprises an organic base; Preferably, the organic base comprises triethylamine and / or N,N-diisopropylethylamine; Preferably, in step (2), post-processing is further included after the reaction is completed; Preferably, the post-processing includes precipitation, filtration, washing, and drying.

8. The preparation method according to any one of claims 4-7, characterized in that, The precipitation involves pouring the reaction mixture into ice-salt water or cold water to precipitate a solid. Preferably, the solvent used for washing includes water, ethanol, or petroleum ether; Preferably, the temperature of the water and ethanol is independently 0-10°C; Preferably, the drying includes vacuum drying; Preferably, the drying temperature is ≤40°C.

9. The application of an indigo reactive dye as described in any one of claims 1-3 or an indigo reactive dye prepared by the preparation method according to any one of claims 4-8 in the coloring of hydrophobic systems.

10. The application according to claim 9, characterized in that, The applications include coloring scented candles, oil-based inks, cosmetics, or engineering plastics with blue reactive dyes.

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