Triphenylmethane polyether dye and preparation method thereof

Abstract

The invention 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 oxidizing agent into a triphenylmethane polyether dye leuco body aqueous solution at 40-60 DEG C, and adding an acid-binding agent to maintain a proper pH value so as to complete oxidation; the organic catalyst is a ferrocene-rotaxene iron compound; (2) adjusting the pH value by using an acid-binding agent aqueous solution, and filtering to remove the organic catalyst while the solution is hot; and carrying out vacuum distillation on the filtrate, removing water, and carrying out filter pressing to obtain the triphenylmethane polyether dye. By adopting the improved rotaene iron catalyst, the catalytic effect is obviously improved, the reaction temperature and the activation energy are reduced, so that the defect of excessive oxidation of hydrogen peroxide is overcome, milder oxygen can be directly used as an oxidizing agent, a large amount of manganese slag is avoided, introduction of manganese metal is eradicated technically, and the production cost is reduced. The obtained product meets the EN71-3 standard, and the green process is really applied to the practice level.

Description

Technical Field

[0001] The present invention relates to the technical field of dye preparation, in particular to a triphenylmethane polyether dye and a preparation method thereof. Background Art

[0002]

[0003] Triphenylmethane dyes, such as those in Formula I, primarily include acid dyes and polyether dyes. They share the characteristics of vibrant colors, high absorption coefficients, excellent water solubility, and low physiological toxicity. These dyes are not only used for dyeing and printing wool, nylon, and silk, but are also widely used in daily chemical products (such as dishwashing liquids, soaps, toilet cleaners, bathing beach water, and indoor bathroom water), cultural and educational products (such as watercolor pens and finger paints), agricultural products (pesticides, fertilizers, and seeds), artificial turf, inkjet inks, food, medicine, and cosmetics.

[0004] Currently, the mainstream oxidation process for this type of triphenylmethane dye uses manganese dioxide as the oxidant. A disadvantage of this process is that the manganese sulfate produced ultimately becomes manganese slag. For example, an annual production of 600 tons of triphenylmethane polyether dyes uses 95 tons of manganese dioxide, resulting in approximately 700 tons of manganese waste slag. Currently, 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 wastes energy, and discharge into wastewater treatment systems significantly increases environmental pressure.

[0005] The oxidation process for this type of triphenylmethane dyes also uses annulare iron or iron phthalocyanine as a catalyst 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 dark product color that does not meet quality standards, and as a result, this type of process has not been truly industrialized. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the technical defects of the background technology and provide a triphenylmethane polyether dye and a preparation method thereof. The present invention provides a green oxidation process for triphenylmethane polyether dyes; the present invention adopts an improved version of annulare iron catalyst, which significantly improves the catalytic effect, reduces the reaction temperature and activation energy, thereby overcoming the defect of excessive oxidation of hydrogen peroxide, and can directly use milder oxygen as an oxidant, avoiding a large amount of manganese slag and eliminating the introduction of manganese, a heavy metal, in the process. The obtained product complies with the EN 71-3 standard and truly applies the green process to the practical level.

[0007] The technical solutions adopted by the present invention to solve the above technical problems are as follows:

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

[0009] (1) An aqueous solution of a leuco form of a triphenylmethane polyether dye of formula I is heated at 40-60° C., an organic catalyst and an oxidant are added, and an acid-binding agent is added to maintain a suitable pH to complete oxidation;

[0010]

[0011] Wherein, 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, i.e., 6,13-ferrocenyl-5,14-dihydrodibenzo[b,i][1,4,8,11]tetraaza

[14] annulene iron:

[0013]

[0014] (2) adjusting the pH with an acid-binding agent aqueous solution and filtering while hot to remove the organic catalyst; vacuum distilling the filtrate to remove water, and filtering to obtain a liquid polyether dye, i.e., a 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 form is 0.5% to 2.0%.

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

[0019] More preferably, the molar ratio of the hydrogen peroxide to the leuco form is 1.2 to 2.0:1, more preferably 1.3 to 1.5:1; the molar ratio of the pure oxygen to the 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 of sodium hydroxide, baking soda, soda ash, and lithium hydroxide, or a mixture thereof, 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 present invention has the following beneficial effects:

[0024] (1) The oxidation process of the present invention is green and environmentally friendly, and produces very little waste residue (catalyst and a small amount of inorganic salt);

[0025] (2) The process of the present invention eliminates the introduction of manganese, which complies with the European heavy metal standard EN 71-3 that products that come into contact with the human body must comply with;

[0026] (3) The present invention overcomes the defect of dark color light caused by the simple annular iron-hydrogen peroxide process, thereby ensuring product quality. DETAILED DESCRIPTION

[0027] In order to better understand the content of the present invention, the following is further described in conjunction with specific examples. It should be understood that these examples are only used to further illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content described in the present invention, those skilled in the art may make some non-essential changes or adjustments to the present invention, which still fall within the scope of protection of the present invention.

[0028] Example 1

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

[0030] In a 1000ml four-necked flask, add 566g of a leuco solution (0.18mol) of a triphenylmethane polyether dye of formula III, pH 2.2, stir, heat to 50-55°C, add 2.11g of a ferrocene-annulene iron complex (2.7mmol), stir rapidly for 20 minutes, and slowly introduce about 43g (1.62mol) of oxygen into the liquid for about 8 hours. During this period, add a 10% aqueous lithium hydroxide solution dropwise to control the pH of the oxidizing solution to 1.5-2.5, 50-55°C. When the pH remains substantially unchanged, take a sample and confirm that the oxidation is complete by HPLC. Add a 10% aqueous lithium hydroxide solution while stirring, adjust the pH to 5.5-6.5, and filter while hot to remove the organic catalyst. Heat the neutralized solution, perform vacuum distillation to remove water, and filter while hot to obtain 215.8g of filtrate (maximum absorption wavelength 630nm, brilliance difference ΔC 0.18, color value 99.5L·g -1 cm -1 ).

[0031]

[0032] Example 2

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

[0034] In a 1000ml four-necked flask, add 635g of a leuco form aqueous solution of a triphenylmethane polyether dye of formula IV (0.16mol), pH 2.4, stir, heat to 45-50°C, add 1.93g of a ferrocene-annulene iron complex (2.5mmol), stir rapidly for 20 minutes, and slowly introduce about 39g (1.22mol) of oxygen into the liquid for about 8 hours. During this period, add a 13% aqueous solution of sodium carbonate dropwise to control the pH of the oxidizing solution to 1.5-2.5, 45-50°C. When the pH remains essentially unchanged, take a sample and confirm that the oxidation is complete by HPLC. Add a 13% aqueous solution of sodium carbonate while stirring, adjust the pH to 5.5-6.5, and filter while hot to remove the organic catalyst. Heat the neutralized solution, perform vacuum distillation to remove water, and filter while hot to obtain 331.2g of filtrate (maximum absorption wavelength 630nm, brilliance 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 comprises the following steps:

[0038] In a 1000ml four-necked flask, 583.8g of a leuco form aqueous solution of triphenylmethane polyether dye of formula V (0.15mol) was added, pH 2.2, stirred, heated to 45-50°C, 1.82g of a ferrocene-annulene iron complex (2.37mmol) was added, and the mixture was rapidly stirred for 20 minutes. About 39g (1.22mol) of oxygen was slowly introduced into the liquid for about 8 hours. During this period, a 10% aqueous lithium hydroxide solution was added dropwise to control the pH of the oxidizing solution to 1.5-2.5, and the temperature was 45-50°C. When the pH remained substantially unchanged, a sample was taken and HPLC was used to confirm that the oxidation was complete. While stirring, a 10% aqueous lithium hydroxide solution was added to adjust the pH to 5.5-6.5, and the organic catalyst was removed by hot filtration. The neutralized solution was heated, vacuum distilled, and water was removed. The solution was filter-pressed while hot to obtain 311.3g of filtrate (maximum absorption wavelength 649nm, brilliance difference ΔC 0.15, color value 56.5L·g -1 cm -1 ).

[0039]

[0040] Example 4

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

[0042] In a 1000ml four-necked flask, add 605g of a leuco form aqueous solution of triphenylmethane polyether dye of formula VI (0.16mol), pH 2.2, stir, heat to 50-55°C, add 1.92g of ferrocene-annulene iron complex (2.5mmol), stir rapidly for 20 minutes, and slowly introduce about 40g (1.25mol) of oxygen into the liquid for about 8 hours. During this period, add 8% sodium bicarbonate aqueous solution dropwise to control the pH of the oxidizing solution to 1.5-2.5, and the temperature to 50-55°C. When the pH remains substantially unchanged, take a sample and confirm that the oxidation is complete by HPLC. Add 8% sodium bicarbonate aqueous solution while stirring, adjust the pH to 5.5-6.5, and filter while hot to remove the organic catalyst. Heat the neutralized solution, perform vacuum distillation to remove water, and filter while hot to obtain 322.4g of filtrate (maximum absorption wavelength 610nm, brilliance 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 comprises the following steps:

[0046] In a 1000ml four-necked flask, add 635g of a leuco form aqueous solution of triphenylmethane polyether dye of formula VII (0.17mol), pH 2.2, stir, heat to 45-50°C, add 1.92g of ferrocene-annulene iron complex (2.5mmol), stir rapidly for 20 minutes, and slowly introduce about 39g (1.22mol) of oxygen into the liquid for about 8 hours. During this period, add 10% lithium hydroxide aqueous solution dropwise to control the pH of the oxidizing solution to 1.5-2.5, and the temperature to 45-50°C. When the pH remains substantially unchanged, take a sample and confirm that the oxidation is complete by HPLC. Add 10% lithium hydroxide aqueous solution while stirring, adjust the pH to 5.5-6.5, and filter while hot to remove the organic catalyst. Heat the neutralized solution, perform vacuum distillation, remove water, and filter while hot to obtain 333.8g of filtrate (maximum absorption wavelength 594nm, brilliance difference ΔC 0.18, color value 34.3L·g -1 cm -1 ).

[0047]

[0048] Example 6

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

[0050] In a 1000ml four-necked flask, add 547g of a leuco form aqueous solution of a triphenylmethane polyether dye of formula VIII (0.22mol), pH 2.2, stir, heat to 50-55°C, add 2.7g of a ferrocene-annulene iron complex (3.5mmol), stir rapidly for 20 minutes, and slowly introduce about 39g (1.22mol) of oxygen into the liquid for about 8 hours. During this time, add 10% aqueous lithium hydroxide solution dropwise to control the pH of the oxidizing solution to 1.5-2.5 and the temperature to 50-55°C. When the pH remains essentially unchanged, take a sample and confirm that the oxidation is complete by HPLC. Add 10% aqueous lithium hydroxide 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, perform vacuum distillation to remove water, and filter while hot to obtain 262.5g of filtrate (maximum absorption wavelength 594nm, brilliance difference ΔC 0.09, color value 55.8L·g -1 cm -1 ).

[0051]

[0052] Example 7

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

[0054] To a 1000ml four-necked flask, add 635g of a leuco form of a triphenylmethane polyether dye of Formula IV (0.16mol) in water, pH 2.4, and stir. Raise the temperature to 50-55°C, add 1.92g of a ferrocene-annulene iron complex (2.5mmol), and stir rapidly for 20 minutes. Then, slowly add 24.7g (0.20mol) of 27.5% hydrogen peroxide dropwise over approximately 45 minutes. During this time, add 10% aqueous lithium hydroxide solution dropwise, controlling the pH of the oxidation solution at 1.5-2.5 and 50-55°C. Once the pH remains essentially constant, sample the solution and confirm complete oxidation by HPLC. While stirring, add 10% aqueous lithium hydroxide solution to adjust the pH to 5.5-6.5. Filter while hot to remove the organic catalyst. The neutralized solution was heated and vacuum distilled to remove water. The solution was 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 comprises the following steps:

[0057] To a 1000ml four-necked flask, add 678g of a leuco form of a triphenylmethane polyether dye of Formula IV (0.17mol) to a pH of 2.4, stir, adjust the temperature to 25-35°C, add 17.7g of 92% electrolytic manganese dioxide (0.187mol), stir rapidly for 20 minutes, and slowly dropwise add 73.7g (0.22mol) of a 30% aqueous sulfuric acid solution, controlling the pH of the oxidation solution to 1.8-2.5 at 30-35°C for about 45 minutes. Incubate for 1 hour, sample, and confirm complete oxidation by HPLC. Add 20% aqueous soda ash solution with stirring, adjust the pH to 9.0-9.5, hold for 30 minutes, and filter. If the pH does not drop, wash the manganese residue with a small amount of water, and combine the resulting filtrates. The filtrate was added with 30% aqueous sulfuric acid to pH 6.0-6.8, heated, vacuum distilled to remove water, and filtered 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 comprises the following steps:

[0060] To a 1000ml four-necked flask, add 635g of a leuco form of a triphenylmethane polyether dye of Formula IV (0.16mol) in water, pH 2.4, and stir. Raise the temperature to 45-50°C, add 1.3g of a ferrocene-annulene iron complex (3.8mmol), and stir rapidly for 20 minutes. Then, slowly add 24.7g (0.20mol) of 27.5% hydrogen peroxide dropwise over approximately 45 minutes. During this time, add 10% aqueous lithium hydroxide solution dropwise, controlling the pH of the oxidation solution at 1.5-2.5, at 45-50°C. Continue until the pH remains essentially constant, then sample and confirm complete oxidation by HPLC. While stirring, add 10% aqueous lithium hydroxide solution to adjust the pH to 5.5-6.5. Filter while hot to remove the organic catalyst. The neutralized solution was heated and vacuum distilled to remove water. The solution was 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] The present invention provides a method for preparing a triphenylmethane polyether dye. The main steps include: oxidizing a leuco form aqueous solution of the triphenylmethane polyether dye using 6,13-ferrocenyl-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; filtering the oxidized liquid to remove a very small amount of catalyst, vacuum distilling to remove water, and then filtering to remove a small amount of inorganic salts to obtain a water-free and salt-free liquid polyether dye product. The present invention, through the efficient green catalysis of the ferrocenyl-annulene iron complex, satisfactorily solves the large amount of solid waste associated with conventional processes, and has excellent environmental protection significance.

[0062] The above description is not intended to limit the present invention, and the present invention is not limited to the above examples. Any changes, modifications, additions or substitutions made by persons of ordinary skill in the art within the spirit and scope of the present invention shall also fall within the scope of protection of the present invention.

Claims

1. A method for preparing a triphenylmethane polyether dye, characterized in that: The steps include: (1) An aqueous solution of a leuco form of a triphenylmethane polyether dye of formula I is heated at 40-60° C., an organic catalyst and an oxidant are added, and an acid-binding agent is added to maintain a suitable pH to complete oxidation; Wherein, 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; The organic catalyst is a ferrocene-annulene iron complex of formula II, i.e., 6,13-ferrocenyl-5,14-dihydrodibenzo[b,i][1,4,8,11]tetraaza[14]annulene iron: (2) Adjusting the pH with an acid-binding agent aqueous solution, filtering while hot to remove the organic catalyst; vacuum distilling the filtrate to remove water, and filtering by pressure to obtain a triphenylmethane polyether dye.

2. The method for preparing a triphenylmethane polyether dye according to claim 1, wherein In step (1), the molar ratio of the organic catalyst to the leuco form is 0.5% to 2.0%.

3. The preparation method of a triphenylmethane polyether dye according to claim 1, wherein In step (1), the oxidant is any one of hydrogen peroxide, pure oxygen, and air.

4. The method for preparing a triphenylmethane polyether dye according to claim 3, wherein The molar ratio of the hydrogen peroxide to the leuco form is 1.2-2.0:1; the molar ratio of the pure oxygen to the leuco form is 5-12:

1.

5. The method for preparing a triphenylmethane polyether dye according to claim 1, wherein In step (1), the acid binding agent is an aqueous solution of any one of sodium hydroxide, baking soda, soda ash, and lithium hydroxide, or a mixture of several of them.

6. The method for preparing a triphenylmethane polyether dye according to claim 5, wherein: The concentration of the acid binding agent is 5% to 15%.

7. The preparation method of a triphenylmethane polyether dye as claimed in claim 1, wherein In step (1), the pH is 1.0 to 3.

5.

8. The method for preparing a triphenylmethane polyether dye according to claim 1, wherein In step (2), the pH is 4.5 to 8.

5.

9. The method for preparing a triphenylmethane polyether dye according to claim 8, wherein The pH is 5.0 to 7.

0.

10. A triphenylmethane polyether dye, characterized in that: The dye is prepared by the method for preparing a triphenylmethane polyether dye according to any one of claims 1 to 9.

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