Water-soluble biological indigo blue and preparation method thereof

Abstract

The invention relates to natural dye and green chemical industry, and particularly discloses water-soluble biological indigo blue and a preparation method thereof. The water-soluble biological indigo comprises the following raw material components in parts by weight: 80-90 parts of a biological-based indigo concentrated solution; 0.5 to 1 part of dimethyl sulfoxide; 10 to 15 parts of a solubilizer A; 5-10 parts of a solubilizer B; and 10 to 15 parts of deionized water. According to the invention, the bio-based indigo concentrated solution synthesized by a biological method is used as a raw material, the water-soluble compound is innovatively formed through beta-cyclodextrin inclusion and povidone compounding, and the water-soluble compound has relatively high water solubility; the water solubility of the product is greater than or equal to 50g / L, the stability is excellent, the obtained indigo dye is natural in source, environment-friendly and high in water solubility, secondary pollution of the traditional dye to the environment is avoided, and the indigo dye is suitable for sustainable chemical industry and green dyeing and finishing industries and can be widely applied to the fields of textile dyeing, water-based ink, cosmetic color developing agents, medicines and the like.

Description

Technical Field

[0001] This invention relates to natural dyes and green chemicals, specifically to a water-soluble bio-indigo and its preparation method. Background Technology

[0002] Traditional natural indigo is mainly extracted from plants containing indigo (such as storax and isatis). The traditional method of extracting indigo in my country is to soak the stems and leaves of plants such as storax in a certain amount of water and let them ferment at room temperature. After fermentation, the liquid is separated, lime is added and stirred repeatedly to allow the soaking liquid to come into full contact with oxygen, so that the indigo precipitates. The mixture is then filtered to obtain indigo paste, which is then refined to obtain a higher indigo content.

[0003] Because plants contain low levels of indigo, the extraction process is complex and requires large areas of land. While chemically synthesized indigo boasts high purity and conversion rates, it involves harmful chemicals such as aniline, posing environmental pollution and safety risks. Biosynthetic indigo, on the other hand, utilizes synthetic biology techniques. First, a series of genes required for indigo production in plants are identified. These genes are then cloned, edited, and integrated into the genome of bacteria, resulting in engineered strains capable of producing natural indigo. Finally, indigo is extracted through fermentation using sugars and amino acids as nutrients. Biosynthetic indigo is produced in fermenters, offering high efficiency and containing none of the raw materials needed for chemical indigo production, making it safer and more sustainable.

[0004] Biosynthetic indigo is a green and sustainable method with the advantage of high color fastness. However, indigo is a sparingly soluble crystal with poor water solubility. During the dyeing process, it must be reduced to the leuco form before dyeing, which is not only cumbersome but also generates a large amount of wastewater, increasing the environmental burden and limiting its application. Therefore, developing bio-derived indigo dyes with good water solubility is of significant importance. Summary of the Invention

[0005] In order to overcome at least one technical problem existing in the prior art, the present invention provides a water-soluble biological indigo and a method for preparing the same.

[0006] The technical solution of the present invention is as follows: The present invention first provides a water-soluble bio-indigo, characterized in that it comprises the following raw material components in parts by weight: 80-90 parts of bio-based indigo concentrate; 0.5-1 part of dimethyl sulfoxide; 10-15 parts of solubilizer A; 5-10 parts of solubilizer B; and 10-15 parts of deionized water.

[0007] The aforementioned bio-based indigo concentrate is a bio-based indigo concentrate synthesized using biological methods.

[0008] Preferably, the solubilizer A is β-cyclodextrin.

[0009] Preferably, the solubilizer B is polyvinyl ketone K30.

[0010] Preferably, the solid content of the bio-based indigo concentrate is 40-50% by weight.

[0011] Preferably, the solid content of the bio-based indigo concentrate is 40-50%.

[0012] Preferably, the indigo content in the solids is more than 60% by weight.

[0013] This invention also provides a method for preparing water-soluble bio-indigo, comprising the following steps: Mix β-cyclodextrin, povidone K30 and deionized water evenly to obtain mixture A; Dimethyl sulfoxide was added to the bio-based indigo concentrate and stirred to obtain mixture B; Mixture A and mixture B together and stir to obtain mixture C; The water-soluble biological indigo is obtained by drying the mixture C.

[0014] Preferably, dimethyl sulfoxide is added to the bio-based indigo concentrate and stirred at 30-40°C for 30-60 minutes to obtain mixture B; Preferably, mixture A and mixture B are mixed and stirred at 35-40°C for 30-60 minutes to obtain mixture C.

[0015] Preferably, the drying specifically refers to spray drying or freeze drying.

[0016] Beneficial effects: This invention provides a method for producing a bio-based indigo concentrate synthesized by biological methods. It innovatively combines β-cyclodextrin inclusion with povidone to form a water-soluble complex with high water solubility. The product has a water solubility ≥50g / L, excellent stability, and the resulting indigo dye is naturally derived, environmentally friendly, and highly water-soluble. This avoids the secondary pollution caused by traditional dyes and is suitable for sustainable chemical and green dyeing and finishing industries. It can be widely used in textile dyeing, water-based inks, cosmetic color developers, pharmaceuticals, and other fields.

[0017] Furthermore, the raw material bio-based indigo is green and environmentally friendly, with lower costs than plant-based indigo, easier to produce, less loss compared to traditional indigo processing, and increases the water solubility of indigo, thus broadening its application areas and improving its utilization. Detailed Implementation

[0018] The following embodiments further limit the present invention, but the embodiments do not limit the present invention in any way.

[0019] Example 1: Preparation of water-soluble bio-indigo Raw material composition by weight: 80 parts of bio-based indigo concentrate (solid content 40-50w, indigo content in solids ≥ 60w%), 0.5 parts of DMSO, 10 parts of β-cyclodextrin, 5 parts of povidone K30, and 10 parts of deionized water.

[0020] Preparation method: (1) Mix 10 parts of β-cyclodextrin, 5 parts of povidone K30 and 10 parts of deionized water evenly and let stand for later use; (2) Add 0.5 parts of DMSO to 80 parts of bio-based indigo concentrate, control the temperature at 30℃, stir thoroughly for 30 minutes, and set aside; (3) Mix the above liquids thoroughly and stir at 35°C for 30 minutes; (4) The mixture is spray-dried to obtain the water-soluble biological indigo.

[0021] Example 2 Preparation of water-soluble bio-indigo Raw material composition by weight: 80 parts of bio-based indigo concentrate (solid content 40-50w, indigo content in solids ≥ 60w%), 0.5 parts of DMSO, 10 parts of β-cyclodextrin, 5 parts of povidone K30, and 10 parts of deionized water.

[0022] Preparation method: (1) Mix 10 parts of β-cyclodextrin, 5 parts of povidone K30 and 10 parts of deionized water evenly and let stand for later use; (2) Add 0.5 parts of DMSO to 80 parts of bio-based indigo concentrate, control the temperature at 30℃, stir thoroughly for 30 minutes, and set aside; (3) Mix the above liquids thoroughly and stir at 35°C for 60 minutes; (4) The mixture is spray-dried to obtain the water-soluble biological indigo.

[0023] Example 3 Preparation of water-soluble bio-indigo Raw material composition by weight: 85 parts of bio-based indigo concentrate (solid content 40-50w, indigo content in solids ≥ 60w%), 0.75 parts of DMSO, 12.5 parts of β-cyclodextrin, 7.5 parts of povidone K30, and 12.5 parts of deionized water.

[0024] Preparation method: (1) Mix 12.5 parts of β-cyclodextrin, 7.5 parts of povidone K30 and 12.5 parts of deionized water evenly and let stand for later use; (2) Add 0.75 parts of DMSO to 85 parts of bio-based indigo concentrate, control the temperature at 35℃, stir thoroughly for 45 minutes, and set aside. (3) Mix the two liquids thoroughly and stir at 40°C for 30 minutes; (4) The mixture is spray-dried to obtain the water-soluble biological indigo.

[0025] Example 4 Preparation of water-soluble bio-indigo Raw material composition by weight: 85 parts of bio-based indigo concentrate (solid content 40-50w, indigo content in solids ≥ 60w%), 0.75 parts of DMSO, 12.5 parts of β-cyclodextrin, 7.5 parts of povidone K30, and 12.5 parts of deionized water.

[0026] Preparation method: (1) Mix 12.5 parts of β-cyclodextrin, 7.5 parts of povidone K30 and 12.5 parts of deionized water evenly and let stand for later use; (2) Add 0.75 parts of DMSO to 85 parts of bio-based indigo concentrate, control the temperature at 35℃, stir thoroughly for 45 minutes, and set aside. (3) Mix the two liquids thoroughly and stir at 40°C for 60 minutes; (4) The mixture is spray-dried to obtain the water-soluble biological indigo.

[0027] Example 5 Preparation of water-soluble bio-indigo Raw material composition by weight: 90 parts of bio-based indigo concentrate (solid content 40-50w, indigo content in solids ≥ 60w%), 1 part of DMSO, 15 parts of β-cyclodextrin, 10 parts of povidone K30, and 15 parts of deionized water.

[0028] Preparation method: (1) Mix 15 parts of β-cyclodextrin, 10 parts of povidone K30 and 15 parts of deionized water evenly and let stand for later use; (2) Add 1 part of DMSO to 90 parts of bio-based indigo concentrate, control the temperature at 40℃, stir thoroughly for 60 minutes, and set aside. (3) Mix the two liquids thoroughly and stir at 40°C for 30 minutes; (4) The mixture is spray-dried to obtain the water-soluble biological indigo.

[0029] Example 6 Preparation of water-soluble bio-indigo Raw material composition by weight: 90 parts of bio-based indigo concentrate (solid content 40-50w, indigo content in solids ≥ 60w%), 1 part of DMSO, 15 parts of β-cyclodextrin, 10 parts of povidone K30, and 15 parts of deionized water.

[0030] Preparation method: (1) Mix 15 parts of β-cyclodextrin, 10 parts of povidone K30 and 15 parts of deionized water evenly and let stand for later use; (2) Add 1 part of DMSO to 90 parts of bio-based indigo concentrate, control the temperature at 40℃, stir thoroughly for 60 minutes, and set aside. (3) Mix the two liquids thoroughly and stir at 40°C for 60 minutes; (4) The mixture is spray-dried to obtain the water-soluble biological indigo.

[0031] Comparative Example 1: Preparation of water-soluble bio-indigo Raw material composition by weight: 80 parts of bio-based indigo concentrate (solid content 40-50w, indigo content in solids ≥ 60w%), 0.5 parts of DMSO, 15 parts of povidone K30, and 10 parts of deionized water.

[0032] Preparation method: (1) Mix 15 parts of povidone K30 with 10 parts of deionized water evenly and let stand for later use; (2) Add 0.5 parts of DMSO to 80 parts of bio-based indigo concentrate, control the temperature at 30℃, stir thoroughly for 30 minutes, and set aside; (3) Mix the above liquids thoroughly and stir at 35°C for 30 minutes; (4) The mixture is spray-dried to obtain the water-soluble biological indigo.

[0033] The difference between Comparative Example 1 and Example 1 is that β-cyclodextrin is not used.

[0034] Comparative Example 2: Preparation of water-soluble bio-indigo Raw material composition by weight: 80 parts of bio-based indigo concentrate (solid content 40-50w, indigo content in solids ≥ 60w%), 0.5 parts of DMSO, 15 parts of β-cyclodextrin, and 10 parts of deionized water.

[0035] Preparation method: (1) Mix 15 parts of β-cyclodextrin with 10 parts of deionized water evenly and let stand for later use; (2) Add 0.5 parts of DMSO to 80 parts of bio-based indigo concentrate, control the temperature at 30℃, stir thoroughly for 30 minutes, and set aside; (3) Mix the above liquids thoroughly and stir at 35°C for 30 minutes; (4) The mixture is spray-dried to obtain the water-soluble biological indigo.

[0036] The difference from Example 1 is that povidone K30 is not used.

[0037] Comparative Example 3: Preparation of Water-Soluble Bio-Indigo Raw material composition by weight: 80 parts of bio-based indigo concentrate (solid content 40-50w, indigo content in solids ≥ 60w%), 0.5 parts of DMSO, and 10 parts of deionized water.

[0038] Preparation method: (1) Add 0.5 parts of DMSO to 80 parts of bio-based indigo concentrate, control the temperature at 30℃, stir thoroughly for 30 minutes, and set aside; (2) Mix the above liquid with deionized water evenly and stir at 35°C for 30 minutes; (3) The mixture is spray-dried to obtain the water-soluble biological indigo.

[0039] The difference from Example 1 is that β-cyclodextrin and povidone K30 are not used.

[0040] In the above examples and comparative examples, the indigo content was determined by high-performance liquid chromatography (HPCL) using an EC-C18 column (150 mm × 4.6 mm, 2.7 μm), a column temperature of 30 °C, a mobile phase of methanol:water (7:3, V / V), a flow rate of 0.5 mL / min, a detection wavelength of 287 nm, and an injection volume of 5 μL. The solubility of indigo in different examples and comparative examples is shown in Table 1.

[0041] Table 1. Solubility test results of the water-soluble biological indigo of this invention experiment Indigo content (%) in the finished product Solubility of the finished product in water (g / L) Solubility of pure indigo (g / L) Example 1 35.1 89.2 31.3 Example 2 34.6 97.6 33.8 Example 3 37.3 95.6 35.7 Example 4 37.5 106.5 39.9 Example 5 37.9 103.2 39.1 Example 6 38.6 111.7 43.1 Comparative Example 1 39.4 34.5 13.6 Comparative Example 2 37.7 67.4 25.4 Comparative Example 3 45.6 3.3 1.5 As can be seen from the experimental data in Table 1, the water-soluble bio-indigo prepared in Examples 1-6 has a solubility in water of ≥50g / L, indicating high solubility.

[0042] Furthermore, the experimental data in Table 1 show that the water-soluble bio-indigo prepared in Comparative Example 3 without β-cyclodextrin and povidone K30 has lower solubility. However, the water-soluble bio-indigo prepared in Comparative Examples 1 and 2 also has significantly lower solubility in water than in Example 1. This indicates that β-cyclodextrin and povidone K30 are crucial in this invention. In the process of preparing water-soluble bio-indigo from bio-based indigo concentrate, both β-cyclodextrin and povidone K30 must be added simultaneously to achieve high solubility. The water-soluble bio-indigo prepared with both β-cyclodextrin and povidone K30 has significantly higher solubility than that prepared with only β-cyclodextrin or povidone K30 alone. In the process of preparing water-soluble bio-indigo from bio-based indigo concentrate, the simultaneous addition of β-cyclodextrin and povidone K30 can synergistically improve the solubility of the prepared water-soluble bio-indigo.

Claims

1. A water-soluble biological indigo, characterized in that, The raw material components include the following parts by weight: 80-90 parts of bio-based indigo concentrate; 0.5-1 part of dimethyl sulfoxide; 10-15 parts of solubilizer A; 5-10 parts of solubilizer B; and 10-15 parts of deionized water.

2. The water-soluble biological indigo according to claim 1, characterized in that, The solubilizer A is β-cyclodextrin.

3. The water-soluble biological indigo according to claim 1, characterized in that, The solubilizer B is polyvinyl ketone K30.

4. The water-soluble biological indigo according to claim 1, characterized in that, The solid content of the bio-based indigo concentrate is 40-50% by weight.

5. The water-soluble biological indigo according to claim 1, characterized in that, The solid content of the bio-based indigo concentrate is 40-50%.

6. The water-soluble biological indigo according to claim 1, characterized in that, The indigo content in the solids is over 60% by weight.

7. The method for preparing water-soluble biological indigo according to any one of claims 1 to 6, characterized in that, It includes the following steps: Mix β-cyclodextrin, povidone K30 and deionized water evenly to obtain mixture A; Dimethyl sulfoxide was added to the bio-based indigo concentrate and stirred to obtain mixture B; Mixture A and mixture B together and stir to obtain mixture C; The water-soluble biological indigo is obtained by drying the mixture C.

8. The preparation method according to claim 7, characterized in that, Dimethyl sulfoxide was added to the bio-based indigo concentrate and stirred at 30-40°C for 30-60 minutes to obtain mixture B.

9. The preparation method according to claim 7, characterized in that, Mixture A and mixture B together and stir at 35-40℃ for 30-60 minutes to obtain mixture C.

10. The preparation method according to claim 7, characterized in that, The drying process specifically refers to spray drying or freeze drying.