Bio-indigo dye produced by eco-friendly bio-process and fiber dyeing method using same

Abstract

The present invention relates to a bio-indigo dye produced by an eco-friendly bio-process and a fiber dyeing method using same, wherein fibers can be effectively dyed using bio-indigo produced by microorganisms, so that the bio-indigo has potential for industrial-scale productivity and can be used in fiber dyeing using eco-friendly dyes.

Description

Bio-indigo dye produced through an eco-friendly bio-process and a textile dyeing method using the same

[0001] This relates to a bio-indigo dye produced through an eco-friendly bio-process and a method for dyeing textiles using the same.

[0002] Indigo is a well-known natural dye found throughout the biosphere, and several synthetic routes have been developed to produce indigo from petroleum-based feedstocks. Because synthetic indigo derived from petrochemicals uses toxic reactants and catalysts, various environmentally friendly processes have been developed to replace indigo. Environmentally friendly bio-indigo production can involve bio-indigo biosynthesis from indigo-producing plants, such as Indigofera, or bio-indigo production using bioconversion enzymes. However, extraction of natural indigo has several drawbacks; for example, plant cultivation is limited by factors such as water, soil, and natural disasters, which lowers productivity. Therefore, the production of bio-indigo through bioconversion of biomass has attracted considerable interest.

[0003] Conventionally known indigo dyeing methods involve post-processing, either washing the dyed fabric with hot water or neutralizing it by immersing it in an acidic solution. This is to remove any remaining alkaline substances (lye) in the dyed fabric. The reason for removing the lye in this way is that indigo discoloration or fading is generally attributed to the failure to remove the lye. Furthermore, the yellow substance after drying is said to be evidence of the lye or remaining lye. However, even if the lye is sufficiently removed, the problem of rapid discoloration or fading of indigo-dyed fabric remains. Furthermore, discoloration occurs in raw indigo dyeing even without the use of lye.

[0004] To solve these problems, the inventor of the present invention has completed a method for effectively dyeing fibers using bio-indigo dye produced through an eco-friendly bio-process using microorganisms.

[0005] 1. A step of culturing microorganisms and then performing cell sedimentation (cell-down) on the culture solution; and

[0006] A method for producing bio-indigo dye, comprising the step of washing the precipitated cells with distilled water.

[0007] 2. A method for producing bio-indigo dye, wherein in the above 1, the microorganism is an Acinetobacter strain (accession number: KCTC19027P).

[0008] 3. A method for producing bio-indigo dye, further comprising a step of obtaining a supernatant by washing with distilled water after the washing step in the above 1.

[0009] 4. In the above 1, a step of obtaining cell residue after the washing step; and

[0010] A method for producing bio-indigo dye, further comprising a step of drying and then powdering the cell residue.

[0011] 5. Bio-indigo dye for dyeing tweed fibers, produced by the above 3.

[0012] 6. A method for dyeing tweed fibers, comprising the step of immersing tweed fibers in the dye of the above 5 and then heating them to dye them.

[0013] 7. A method for dyeing tweed fibers, wherein in the above 6, the heating is performed at 100°C to 150°C.

[0014] 8. Bio-indigo dye for dyeing cotton fibers, produced by the above 4.

[0015] 9. Step of dissolving the powdered dye of 8 above in water;

[0016] A step of mixing a reducing agent into a solution in which the dye is dissolved; and

[0017] A method for dyeing cotton fibers, comprising the step of immersing cotton fibers in the above mixture and dyeing them.

[0018] 10. A cotton fiber dyeing method, characterized in that in the above 9, the reducing agent is formamidinesulfinic acid.

[0019] 11. A cotton fiber dyeing method in the above 10, wherein the dye and reducing agent are mixed at a concentration of 1:3 to 3:1.

[0020] 12. A cotton fiber dyeing method, further comprising a step of drying the dyed cotton fiber in the above 9.

[0021] The present invention comprises the steps of culturing a microorganism and then performing cell precipitation (cell-down) of the culture solution; and

[0022] A method for producing a bio-indigo dye is provided, comprising a step of washing the precipitated cells with distilled water.

[0023] As used herein, "indigo" refers to a blue dye found throughout the biosphere. The indigo may include natural indigo, synthetic indigo, and microbially produced indigo.

[0024] In this specification, “bio-indigo” may be indigo produced by microorganisms.

[0025] As used herein, the term "dye" refers to a coloring agent used for dyeing fibers. In one embodiment, the dye may be in the form of an aqueous solution or powder, but is not limited to the form.

[0026] In one embodiment of the present invention, the microorganism may be an Acinetobacter strain (Accession No.: KCTC19027P).

[0027] The term "cultivation" in the present invention refers to a method of growing microorganisms under appropriately artificially controlled environmental conditions. In one embodiment, the culturing may be performed using a method widely known in the art, and may be continuously cultured in a batch process, fed batch process, or repeated fed batch process. Specifically, the culturing may be batch culture, fed-batch culture, or a combination thereof.

[0028] In one embodiment of the present invention, the medium used for culturing can satisfy the requirements of a specific strain in an appropriate manner by controlling temperature, pH, etc. under aerobic conditions in a general medium containing a suitable carbon source, nitrogen source, amino acid, vitamin, etc. As a carbon source that can be used, a mixed sugar of glucose and xylose is used as a main carbon source, and in addition, sugars and carbohydrates such as sucrose, lactose, fructose, maltose, starch, and cellulose; oils and fats such as soybean oil, sunflower oil, castor oil, and coconut oil; fatty acids such as palmitic acid, stearic acid, and linoleic acid; alcohols such as glycerol and ethanol; and organic acids such as acetic acid. These substances can be used individually or as a mixture. As a nitrogen source that can be used, inorganic nitrogen sources such as ammonia, ammonium sulfate, ammonium chloride, ammonium acetate, ammonium phosphate, ammonium carbonate, and ammonium nitrate; Organic nitrogen sources such as amino acids such as glutamic acid, methionine, and glutamine, and peptone, NZ-amine, meat extract, yeast extract, malt extract, corn steep liquor, casein hydrolysate, fish or its decomposition products, defatted soybean cake or its decomposition products can be used. These nitrogen sources can be used alone or in combination. The medium can contain potassium phosphate monobasic, potassium phosphate dibasic, and the corresponding sodium-containing salts as phosphorus. Potassium dihydrogen phosphate or dipotassium hydrogen phosphate or the corresponding sodium-containing salts can be used as phosphorus. In addition, inorganic compounds such as sodium chloride, calcium chloride, iron chloride, magnesium sulfate, iron sulfate, manganese sulfate, and calcium carbonate can be used. Finally, in addition to the above substances, essential growth substances such as amino acids and vitamins can be used.

[0029] Additionally, suitable precursors may be used in the culture medium. The above-mentioned raw materials may be added to the culture in a batch, fed-batch, or continuous manner during the culture process, but are not particularly limited thereto. The pH of the culture may be adjusted using basic compounds such as sodium hydroxide, potassium hydroxide, or ammonia, or acid compounds such as phosphoric acid or sulfuric acid, in an appropriate manner.

[0030] Specifically, the medium of the present invention may be, but is not limited to, M9 medium. The M9 medium is a minimum nutrient medium composed of 33.7 mM Na2HPO4, 22 mM KH2PO4, 8.55 mM NaCl, 9.35 mM NH4Cl, 0.4% glucose, 1 mM MgSO4, 0.3 mM CaCl2, and trace element solution (134 μM EDTA, 31 μM FeCl3-6H2O, 6.2 μM ZnCl2, 0.76 μM CuCl2-2H2O, 0.42 μM CoCl2-2H2O, 1.62 μM H3BO3, 0.08 μM MnCl2-4H2O), and such a medium is a medium containing a mixture of inorganic nutrients that provide essential elements such as nitrogen, magnesium, calcium, etc. as well as glucose to supply carbon and energy. The above M9 medium is used when bacterial cultures must grow under precisely controlled conditions, as all components are known. The above M9 medium may be used interchangeably with the term "M9 minimal medium." Additionally, the M9 medium of the present invention may additionally contain necessary components, depending on the intended purpose.

[0031] As used herein, “cell-down” means that cultured microorganisms or cells are sedimented.

[0032] In one embodiment of the present invention, the precipitated cells are characterized in that they are washed only with distilled water and not with an organic solvent.

[0033] In one embodiment of the present invention, the dye production method may further include a step of obtaining a supernatant by washing with distilled water after the washing step. In one specific example, the supernatant may be obtained by cooling and thawing, and then heating at 100°C to 150°C.

[0034] In one embodiment of the present invention, the dye production method comprises the steps of obtaining cell residues after the washing step; and

[0035] The step of drying and then powdering the above cell residue may be further included.

[0036] In this specification, the “cell residue” refers to the residue remaining after excluding the supernatant obtained by washing the microbial culture solution with distilled water.

[0037] In one specific embodiment, the powdering step may be drying the cell residue at 50°C to 70°C.

[0038]

[0039] In addition, the present invention provides a bio-indigo dye for dyeing tweed fibers.

[0040] In one embodiment of the present invention, the bio-indigo dye for dyeing tweed fibers may include a supernatant obtained by culturing microorganisms, subjecting the culture solution to cell precipitation, and then washing the precipitated cells with distilled water.

[0041] In addition, the present invention provides a method for dyeing tweed fibers, including the step of immersing tweed fibers in the bio-indigo dye for dyeing tweed fibers and then heating and dyeing them.

[0042] In one embodiment of the present invention, the heating step can be achieved by heating the dye in which the tweed fiber is immersed at 100°C to 150°C, 100°C to 140°C, 100°C to 130°C, 110°C to 130°C or 115°C to 125°C.

[0043] In one embodiment of the present invention, the heating step can be achieved by heating the dye in which the tweed fiber is immersed for 1 minute to 60 minutes, 1 minute to 30 minutes, 5 minutes to 30 minutes, 5 minutes to 20 minutes, or 10 minutes to 20 minutes.

[0044]

[0045] In addition, the present invention provides a bio-indigo dye for dyeing cotton fibers.

[0046] In one embodiment of the present invention, a bio-indigo dye for dyeing cotton fibers may be produced by culturing microorganisms, subjecting the culture solution to cell precipitation (cell-down), washing the precipitated cells with distilled water, drying the resulting cell residue, and then pulverizing the resulting cell residue.

[0047] In addition, the present invention comprises a step of dissolving the bio-indigo dye for dyeing cotton fibers in water;

[0048] A step of mixing a reducing agent into a solution in which the dye is dissolved; and

[0049] A method for dyeing cotton fibers is provided, comprising a step of immersing cotton fibers in the above-described mixed solution and dyeing them.

[0050] In one embodiment of the present invention, the reducing agent may be formamidinesulfinic acid. Sodium dithionite and hydrosulfite, which are reducing agents conventionally used in textile dyeing, are unstable in storage, cause the generation of sulfurous acid gas, and pose a risk of heat generation and ignition upon contact with water. However, formamidinesulfinic acid, which is the reducing agent used in the present invention, can be stably used in indigo dyeing.

[0051] In one embodiment of the present invention, the dye and reducing agent may be mixed at a concentration of 1:10 to 10:1, 1:5 to 5:1, or 1:3 to 3:1.

[0052] In one embodiment of the present invention, the dyeing step may be to dye the cotton fiber after confirming that the color of the mixture changes after mixing the reducing agent. In one specific example, the color change may be a change to green due to a change in the leuco-form of formamidinesulfinic acid, which is the reducing agent.

[0053] In one embodiment of the present invention, a step of rubbing the dyed cotton fiber against air may be further included after the dyeing step.

[0054] In one embodiment of the present invention, the cotton fiber dyeing method may further include a step of drying cotton fiber dyed with a bio-indigo dye for cotton fiber dyeing.

[0055] In one specific example, the drying step may be drying the dyed cotton fiber at 50°C to 80°C, 55°C to 75°C, or 60°C to 70°C.

[0056] The present invention has confirmed an effective textile dyeing method according to the type of textile using bio-indigo dye produced by an eco-friendly bio-process, and in addition to discovering the potential for industrial-level productivity, it can be used for textile dyeing using eco-friendly dyes.

[0057] Figure 1 is a diagram showing the extraction process for producing bio-indigo.

[0058] Figure 2 is a diagram showing the supernatant required for bio-indigo dyeing and the method for producing indigo in the form of a final powder.

[0059] Figure 3 is a diagram showing a method for dyeing a finished tweed material using a bio-indigo supernatant.

[0060] Figure 4 is a diagram showing a method for dyeing finished cotton socks and cotton pants (linen) using bio-indigo powder.

[0061] The present invention will be described in more detail below through examples. However, these examples are intended to exemplify the present invention and the scope of the present invention is not limited to these examples.

[0062]

[0063] Examples and Experimental Examples

[0064] Example 1. Cultivation of bio-indigo production strain

[0065] For the production of bio-indigo of the present invention, an Acinetobacter strain (accession number: KCTC19027P) was used.

[0066] The culture solution of the above strain was incubated for 72 hours, transferred to a 50 mL tube, and cell down was performed. The solution was washed once with distilled water, collected in a bottle, and cooled in a deep freezer for one day. After thawing at room temperature, it was boiled in an autoclave at 121°C for 15 minutes, and then cooled (see Fig. 1).

[0067]

[0068] Example 2. Production of bio-indigo by material

[0069] Since the dyeing method differs depending on the material, each extract was created.

[0070]

[0071] Example 2-1. Production of bio-indigo for dyeing tweed materials.

[0072] Since tweed material can be dyed using the blue indigo supernatant obtained through cell washing with distilled water, the supernatant was collected separately and bio-indigo was extracted (see Figure 2(A)).

[0073]

[0074] Example 2-2. Production of bio-indigo for dyeing cotton (linen) materials

[0075] In the case of cotton (linen), it was difficult to dye with the blue supernatant, so after cell-down, the remaining supernatant was collected in an aluminum dish, dried in a 65℃ oven for one day, and then ground using a mortar and pestle to extract bio-indigo in powder form (see Fig. 2(B)).

[0076]

[0077] Experimental Example 1. Textile Dyeing Using Bio-Indigo

[0078] Experimental Example 1-1. Dyeing of Tweed Material

[0079] After filtering the supernatant of Example 2-1, a large amount of the supernatant was collected in a PP container, and the tweed material of the finished product was placed in it.

[0080] As a result of boiling the above PP container in an autoclave at 121°C for 15 minutes, it was confirmed that the white tweed jacket was dyed blue (sky blue) (see Fig. 3).

[0081]

[0082] Experimental Example 1-2. Dyeing of Cotton (Linen) Material

[0083] In order to utilize the bio-indigo powder extracted as in Example 2-2, dyeing was performed using a reducing agent. After boiling 1 L of water at 60°C, 200 mM NaOH was first added, and then 15 mM formamidinesulfinic acid, a reducing agent, and 7.5 mM bio-indigo were added together and mixed well (see Fig. 4(A)).

[0084] After that, when the green color of the leuco-form began to appear, cotton pants and socks were dyed and rubbed in the air, and it was confirmed that the color of the pants and socks turned blue (see Figures 4(B) and 4(C)).

[0085] At this time, since color fading may occur if washed immediately, it was dried at 65℃ immediately after dyeing, dried once, and then washed with water before dyeing.

[0086]

[0087] Experimental Example 2. Fiber Dyeing Test Results

[0088] In the above experimental example 1-2, washing and friction tests were conducted on the fiber (tweed fabric) dyed using bio-indigo dye.

[0089] As a result, it was confirmed that the dyeing efficiency of the fiber dyed using the original bio-indigo dye was high, as it showed high scores in washing fastness and rubbing fastness (see Table 1).

[0090]

[0091]

[0092]

Claims

1. A step of culturing microorganisms and then performing cell-down on the culture solution; and A method for producing bio-indigo dye, comprising: a step of washing the precipitated cells with distilled water.

2. In claim 1, A method for producing bio-indigo dye, wherein the above microorganism is an Acinetobacter strain (accession number: KCTC19027P).

3. In claim 1, A method for producing bio-indigo dye, further comprising a step of obtaining a supernatant by washing with distilled water after the above washing step.

4. In claim 1, A step of obtaining cell residues after the above washing step; and A method for producing bio-indigo dye, further comprising the step of drying and then powdering the cell residue.

5. A bio-indigo dye for dyeing tweed fibers, produced according to claim 3.

6. A method for dyeing tweed fibers, comprising the step of immersing tweed fibers in the dye of claim 5 and then heating them to dye them.

7. In claim 6, A method for dyeing tweed fibers, wherein the heating is performed at 100°C to 150°C.

8. A bio-indigo dye for dyeing cotton fibers, produced according to claim 4.

9. A step of dissolving the powdered dye of claim 8 in water; A step of mixing a reducing agent into a solution in which the dye is dissolved; and A method for dyeing cotton fibers, comprising the step of immersing cotton fibers in the above mixture and dyeing them.

10. In claim 9, A method for dyeing cotton fiber, characterized in that the reducing agent is formamidinesulfinic acid.

11. In claim 10, A method for dyeing cotton fibers, wherein the dye and reducing agent are mixed at a concentration of 1:3 to 3:

1.

12. In claim 9, A method for dyeing cotton fibers, further comprising the step of drying the dyed cotton fibers.

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