Triphenylmethane polyether dyes and methods for their preparation

Abstract

The application discloses a triphenylmethane polyether dye and a preparation method thereof, and the preparation method comprises the following steps: (1) adding an organic catalyst and an oxidant into a triphenylmethane polyether dye leucoaqueous solution in the interval of 40-60 DEG C, adding an acid-binding agent to maintain a proper pH, and completing oxidation; the organic catalyst is a ferrocene-rotene iron compound; (2) adjusting the pH with an acid-binding agent aqueous solution, removing the organic catalyst by hot filtration, removing water through vacuum distillation of the filtrate, and performing pressure filtration to obtain the triphenylmethane polyether dye. The improved rotene iron catalyst is used in the application, the catalytic effect is obviously improved, the reaction temperature and activation energy are reduced, the defects of excessive hydrogen peroxide oxidation are overcome, and the obtained product meets the EN71-3 standard.

Description

Technical Field

[0001] This invention relates to the field of dye preparation technology, specifically to a triphenylmethane polyether dye and its preparation method. Background Technology

[0002]

[0003] Triphenylmethane dyes, such as those of Formula I, are mainly acid dyes and polyether dyes. Their common characteristics include vibrant colors, extremely high light absorption coefficients, excellent water solubility, and low physiological toxicity. These dyes are not only used for dyeing and printing wool, nylon, and silk, but also extensively used in the coloring of daily chemical products (such as detergents, soaps, toilet cleaners, seaside bathing products, and indoor bathroom water), stationery products (such as watercolor pens and finger paints), agricultural chemical products (pesticides, fertilizers, and seeds), artificial turf, inkjet inks, food, pharmaceuticals, and cosmetics.

[0004] Currently, the mainstream oxidation process for this type of triphenylmethane dye uses manganese dioxide as the oxidant. The drawback of this process is that the resulting manganese sulfate eventually becomes manganese slag. For example, a production line with 600 tons of triarylmethane polyether dyes per year uses 95 tons of manganese dioxide, generating approximately 700 tons of manganese waste. Some literature has proposed recycling the manganese slag to produce manganese sulfate or manganese dioxide, but the actual cleaning process generates a large amount of colored wastewater. Concentrating and recycling this wastewater is energy-intensive, and discharging it into wastewater treatment systems significantly increases environmental pressure.

[0005] The oxidation process for this type of triphenylmethane dye also uses iron arbutin or iron phthalocyanine as catalysts and hydrogen peroxide as an oxidant. However, due to the limited ability of the catalyst to reduce the activation energy of the reaction and the strong oxidizing properties of hydrogen peroxide, over-oxidation occurs, resulting in a darker color in the product that fails to meet quality standards. Consequently, this type of process has not been truly industrialized. Summary of the Invention

[0006] The technical problem to be solved by this invention is to overcome the technical defects of the prior art and provide a triphenylmethane polyether dye and its preparation method. This invention provides a green oxidation process for triphenylmethane polyether dyes; it uses a modified anthracene iron catalyst, which significantly improves the catalytic effect, reduces the reaction temperature and activation energy, thereby overcoming the defect of excessive oxidation by hydrogen peroxide, and allowing the direct use of milder oxygen as the oxidant. This avoids a large amount of manganese slag and eliminates the introduction of manganese, a heavy metal, into the process. The resulting product meets the EN 71-3 standard, and the green process is truly applied to the practical level.

[0007] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0008] A method for preparing a triphenylmethane polyether dye includes the following steps:

[0009] (1) The aqueous solution of triphenylmethane polyether dye leuco dye of Formula I is oxidized by adding an organic catalyst and an oxidant in the range of 40 to 60°C, and adding an acid-binding agent to maintain a suitable pH.

[0010]

[0011] Where X = H, or SO3 - Y = H, or SO3H, or N(CH3)2; R1 = H, or CH3; R2, R3 = H, or (C2H4O) n H, or (C3H6O) n H, 4≤n≤15 and n is an integer;

[0012] The organic catalyst is a ferrocene-annulene iron complex of formula II, namely 6,13-ferroceneyl-5,14-dihydrodibenzo[b,i][1,4,8,11]tetraaza

[14] annulene iron:

[0013]

[0014] (2) Adjust the pH with an acid-binding agent aqueous solution, filter while hot to remove the organic catalyst; vacuum distill the filtrate to remove water, filter under pressure to obtain liquid polyether dye, i.e. triphenylmethane polyether dye.

[0015] The above oxidation reaction formula is as follows:

[0016]

[0017] Preferably, in step (1), the molar ratio of the organic catalyst to the leuco is 0.5% to 2.0%.

[0018] Preferably, in step (1), the oxidant is any one of hydrogen peroxide, pure oxygen, and air, and more preferably pure oxygen.

[0019] More preferably, the molar ratio of hydrogen peroxide to leuco form is 1.2 to 2.0:1, more preferably 1.3 to 1.5:1; and the molar ratio of pure oxygen to leuco form is 5 to 12:1, more preferably 8 to 10:1.

[0020] Preferably, in step (1), the acid-binding agent is an aqueous solution of any one or a mixture of sodium hydroxide, baking soda, soda ash, and lithium hydroxide, with a concentration of 5% to 15%, more preferably lithium hydroxide.

[0021] Preferably, in step (1), the pH is 1.0 to 3.5.

[0022] Preferably, in step (2), the pH is 4.5 to 8.5, more preferably 5.0 to 7.0.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] (1) The oxidation process of this invention is green and environmentally friendly, and generates very little waste residue (catalyst and a small amount of inorganic salts);

[0025] (2) The process of this invention eliminates the introduction of manganese, which complies with the European standard EN 71-3 for heavy metals that products in contact with the human body must meet;

[0026] (3) This invention overcomes the defect of dark color caused by the simple iron-hydrogen peroxide process, thus ensuring product quality. Detailed Implementation

[0027] To better understand the content of this invention, further description is provided below with reference to specific embodiments. It should be understood that these embodiments are only for further illustration of the invention and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the description of this invention, those skilled in the art may make some non-essential modifications or adjustments to the invention, which still fall within the protection scope of this invention.

[0028] Example 1

[0029] A method for preparing a triphenylmethane polyether dye, comprising the following steps:

[0030] In a 1000ml four-necked flask, add 566g of a leuco aqueous solution (0.18mol) of a type III triphenylmethane polyether dye, pH 2.2, stir, and heat to 50–55℃. Add 2.11g of a ferrocene-iron arbutin complex (2.7mmol), stir rapidly for 20 minutes, and slowly introduce approximately 43g (1.62mol) of oxygen submerged over approximately 8 hours. During this period, add 10% lithium hydroxide aqueous solution dropwise to control the pH of the oxidation solution at 1.5–2.5 and the temperature at 50–55℃. Once the pH remains essentially constant, take a sample for HPLC to confirm complete oxidation. Add 10% lithium hydroxide aqueous solution while stirring to adjust the pH to 5.5–6.5, and filter while hot to remove the organic catalyst. Heat the neutralized solution and perform vacuum distillation to remove water. Filter while hot to obtain 215.8g of filtrate (maximum absorption wavelength 630nm, chroma difference ΔC 0.18, color value 99.5 L·g). -1 ·cm -1 ).

[0031]

[0032] Example 2

[0033] A method for preparing a triphenylmethane polyether dye, comprising the following steps:

[0034] In a 1000ml four-necked flask, add 635g of a leuco aqueous solution (0.16mol) of type IV triphenylmethane polyether dye, pH 2.4, stir, and heat to 45-50℃. Add 1.93g of ferrocene-iron arbutin complex (2.5mmol), stir rapidly for 20 minutes, and slowly introduce approximately 39g (1.22mol) of oxygen submerged over approximately 8 hours. During this period, add 13% sodium carbonate solution dropwise to control the pH of the oxidation solution at 1.5-2.5 and the temperature at 45-50℃. Once the pH remains essentially constant, take a sample for HPLC to confirm complete oxidation. Add 13% sodium carbonate solution while stirring to adjust the pH to 5.5-6.5, and filter while hot to remove the organic catalyst. Heat the neutralized solution and perform vacuum distillation to remove water. Filter while hot to obtain 331.2g of filtrate (maximum absorption wavelength 630nm, chroma difference ΔC 0.25, color value 58.1L·g). -1 ·cm -1 ).

[0035]

[0036] Example 3

[0037] A method for preparing a triphenylmethane polyether dye, comprising the following steps:

[0038] In a 1000ml four-necked flask, add 583.8g of a leuco aqueous solution (0.15mol) of type V triphenylmethane polyether dye, pH 2.2, stir, and heat to 45-50℃. Add 1.82g of ferrocene-iron arbutin complex (2.37mmol), stir rapidly for 20 minutes, and slowly introduce approximately 39g (1.22mol) of oxygen submerged over approximately 8 hours. During this period, add 10% lithium hydroxide aqueous solution dropwise to control the pH of the oxidation solution at 1.5-2.5 and the temperature at 45-50℃. Once the pH remains essentially constant, take a sample for HPLC to confirm complete oxidation. Add 10% lithium hydroxide aqueous solution while stirring to adjust the pH to 5.5-6.5, and filter while hot to remove the organic catalyst. Heat the neutralized solution and perform vacuum distillation to remove water. Filter while hot to obtain 311.3g of filtrate (maximum absorption wavelength 649nm, brilliance difference ΔC 0.15, color value 56.5 L·g). -1 ·cm -1 ).

[0039]

[0040] Example 4

[0041] A method for preparing a triphenylmethane polyether dye, comprising the following steps:

[0042] In a 1000ml four-necked flask, add 605g of a leuco aqueous solution (0.16mol) of type VI triphenylmethane polyether dye, pH 2.2, stir, and heat to 50-55℃. Add 1.92g of ferrocene-iron arbutin complex (2.5mmol), stir rapidly for 20 minutes, and slowly introduce approximately 40g (1.25mol) of oxygen submerged for about 8 hours. During this time, add 8% sodium bicarbonate aqueous solution dropwise to control the pH of the oxidation solution at 1.5-2.5 and the temperature at 50-55℃. When the pH remains essentially constant, take a sample for HPLC to confirm complete oxidation. Add 8% sodium bicarbonate aqueous solution while stirring to adjust the pH to 5.5-6.5, and filter while hot to remove the organic catalyst. Heat the neutralized solution and perform vacuum distillation to remove water. Filter while hot to obtain 322.4g of filtrate (maximum absorption wavelength 610nm, chroma difference ΔC 0.09, color value 33.5L·g). -1 ·cm -1 ).

[0043]

[0044] Example 5

[0045] A method for preparing a triphenylmethane polyether dye, comprising the following steps:

[0046] In a 1000ml four-necked flask, add 635g of a leuco aqueous solution (0.17mol) of type VII triphenylmethane polyether dye, pH 2.2, stir, and heat to 45–50℃. Add 1.92g of ferrocene-iron arbutin complex (2.5mmol), stir rapidly for 20 minutes, and slowly introduce approximately 39g (1.22mol) of oxygen submerged over approximately 8 hours. During this period, add 10% lithium hydroxide aqueous solution dropwise to control the pH of the oxidation solution at 1.5–2.5 and the temperature at 45–50℃. Once the pH remains essentially constant, take a sample for HPLC to confirm complete oxidation. Add 10% lithium hydroxide aqueous solution while stirring to adjust the pH to 5.5–6.5, and filter while hot to remove the organic catalyst. Heat the neutralized solution and perform vacuum distillation to remove water. Filter while hot to obtain 333.8g of filtrate (maximum absorption wavelength 594nm, chroma difference ΔC 0.18, color value 34.3 L·g). -1 ·cm -1 ).

[0047]

[0048] Example 6

[0049] A method for preparing a triphenylmethane polyether dye, comprising the following steps:

[0050] In a 1000ml four-necked flask, add 547g of a leuco aqueous solution (0.22mol) of type VIII triphenylmethane polyether dye, pH 2.2, stir, and heat to 50-55℃. Add 2.7g of ferrocene-iron arbutin complex (3.5mmol), stir rapidly for 20 minutes, and slowly introduce approximately 39g (1.22mol) of oxygen submerged over approximately 8 hours. During this period, add 10% lithium hydroxide aqueous solution dropwise to control the pH of the oxidation solution at 1.5-2.5 and the temperature at 50-55℃. Once the pH remains essentially constant, take a sample for HPLC to confirm complete oxidation. Add 10% lithium hydroxide aqueous solution while stirring to adjust the pH to 5.5-6.5, and filter while hot to remove the organic catalyst. Heat the neutralized solution and perform vacuum distillation to remove water. Filter while hot to obtain 262.5g of filtrate (maximum absorption wavelength 594nm, brilliance difference ΔC 0.09, color value 55.8 L·g). -1 ·cm -1 ).

[0051]

[0052] Example 7

[0053] A method for preparing a triphenylmethane polyether dye, comprising the following steps:

[0054] In a 1000 ml four-necked flask, add 635 g of a leuco aqueous solution (0.16 mol) of a type IV triphenylmethane polyether dye, pH 2.4, stir, and heat to 50–55 °C. Add 1.92 g of a ferrocene-iron complex (2.5 mmol), stir rapidly for 20 minutes, and slowly add 24.7 g (0.20 mol) of 27.5% hydrogen peroxide dropwise over approximately 45 minutes. During this time, add a 10% lithium hydroxide aqueous solution dropwise to control the pH of the oxidation solution at 1.5–2.5 and the temperature at 50–55 °C. Once the pH remains essentially constant, take a sample for HPLC to confirm complete oxidation. Add a 10% lithium hydroxide aqueous solution while stirring to adjust the pH to 5.5–6.5, and filter while hot to remove the organic catalyst. The neutralizing solution was heated and vacuum distilled to remove water. The solution was then filtered while hot to obtain 330.6 g of filtrate (maximum absorption wavelength 630 nm, brilliance difference ΔC 0.11, color value 57.6 L·g). -1 ·cm -1 ).

[0055] Comparative Example 1

[0056] A method for preparing a triphenylmethane polyether dye, comprising the following steps:

[0057] In a 1000ml four-necked flask, add 678g of a leuco aqueous solution (0.17mol) of a type IV triphenylmethane polyether dye, pH 2.4, stir, and adjust the temperature to 25-35℃. Add 17.7g of 92% electrolytic manganese dioxide (0.187mol), stir rapidly for 20 minutes, and slowly add 73.7g (0.22mol) of 30% sulfuric acid aqueous solution. Control the pH of the oxidation solution to 1.8-2.5 and the temperature to 30-35℃ for approximately 45 minutes. Continue to maintain the temperature for 1 hour, and take a sample for HPLC to confirm complete oxidation. Add 20% sodium carbonate aqueous solution while stirring to adjust the pH to 9.0-9.5, maintain for 30 minutes (if the pH does not decrease), filter, wash the manganese residue with a small amount of water, and combine the filtrates. Add 30% sulfuric acid aqueous solution to the filtrate to pH 6.0–6.8, heat, and perform vacuum distillation to remove water. Filter while hot to obtain 322.8 g of filtrate (maximum absorption wavelength 630 nm, brilliance difference ΔC 0.12, color value 54.3 L·g). -1 ·cm -1 ).

[0058] Comparative Example 2

[0059] A method for preparing a triphenylmethane polyether dye, comprising the following steps:

[0060] In a 1000 ml four-necked flask, add 635 g of a leuco aqueous solution (0.16 mol) of a type IV triphenylmethane polyether dye, pH 2.4, stir, and heat to 45–50 °C. Add 1.3 g of a ferrocene-iron complex (3.8 mmol), stir rapidly for 20 minutes, and slowly add 24.7 g (0.20 mol) of 27.5% hydrogen peroxide dropwise over approximately 45 minutes. During this time, add a 10% lithium hydroxide aqueous solution dropwise to control the pH of the oxidation solution at 1.5–2.5 and the temperature at 45–50 °C. Once the pH remains essentially constant, take a sample for HPLC to confirm complete oxidation. Add a 10% lithium hydroxide aqueous solution while stirring to adjust the pH to 5.5–6.5, and filter while hot to remove the organic catalyst. The neutralizing solution was heated and vacuum distilled to remove water. The solution was then filtered while hot to obtain 329.8 g of filtrate (maximum absorption wavelength 630 nm, brilliance difference ΔC -3.75, color value 57.2 L·g). -1 ·cm -1 ).

[0061] This invention provides a method for preparing triphenylmethane polyether dyes. The main steps include: oxidizing an aqueous solution of the leuco form of the triphenylmethane polyether dye using 6,13-ferroceneyl-5,14-dihydrodibenzo[b,i][1,4,8,11]tetraaza

[14] annulene iron as a green catalyst and oxygen or hydrogen peroxide as an oxidant; after filtering off a very small amount of catalyst from the oxidized solution, removing water by vacuum distillation, and then removing a small amount of inorganic salt by pressure filtration, to obtain an anhydrous and salt-free liquid polyether dye product. This invention, through the highly efficient green catalysis of the ferrocene-annulene iron composite, perfectly solves the problem of a large amount of solid waste generated in conventional processes, and has excellent environmental protection significance.

[0062] The foregoing description is not intended to limit the invention, nor is the invention limited to the examples given. Any changes, modifications, additions, or substitutions made by those skilled in the art within the scope of the invention should also be considered within the protection scope of the invention.

Claims

1. A method for preparing a triphenylmethane polyether dye, characterized in that, Includes the following steps: (1) The aqueous solution of triphenylmethane polyether dye leuco dye of Formula I is oxidized by adding an organic catalyst and an oxidant in the range of 40~60℃ and adding an acid-binding agent to maintain a suitable pH. ； Where X = H, or SO3 - Y = H, or SO3H, or N(CH3)2; R1 = H, or CH3; R2, R3 = (C2H4O) n H, or (C3H6O) n H, 4≤n≤15 and n is an integer; The organic catalyst is a ferrocene-annulene iron complex of formula II, namely 6,13-ferroceneyl-5,14-dihydrodibenzo[b,i][1,4,8,11]tetraaza[14]annulene iron: ； (2) Adjust the pH with an acid-binding agent aqueous solution, filter while hot to remove the organic catalyst; vacuum distill the filtrate to remove water, filter under pressure to obtain triphenylmethane polyether dye.

2. The method for preparing a triphenylmethane polyether dye as described in claim 1, characterized in that, In step (1), the molar ratio of the organic catalyst to the leuco is 0.5% to 2.0%.

3. The method for preparing a triphenylmethane polyether dye as described in claim 1, characterized in that, In step (1), the oxidant is any one of hydrogen peroxide, pure oxygen, or air.

4. The method for preparing a triphenylmethane polyether dye as described in claim 3, characterized in that, The molar ratio of hydrogen peroxide to leuco form is 1.2~2.0:1; the molar ratio of pure oxygen to leuco form is 5~12:

1.

5. The method for preparing a triphenylmethane polyether dye as described in claim 1, characterized in that, In step (1), the acid-binding agent is an aqueous solution of any one or a mixture of several of sodium hydroxide, baking soda, soda ash, and lithium hydroxide.

6. The method for preparing a triphenylmethane polyether dye as described in claim 5, characterized in that, The concentration of the acid-binding agent is 5% to 15%.

7. The method for preparing a triphenylmethane polyether dye as described in claim 1, characterized in that, In step (1), the pH is 1.0 to 3.

5.

8. The method for preparing a triphenylmethane polyether dye as described in claim 1, characterized in that, In step (2), the pH is 4.5 to 8.

5.

9. The method for preparing a triphenylmethane polyether dye as described in claim 8, characterized in that, The pH is 5.0~7.0.

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