Reactive staining method for black protein fibers based on coupling staining

Abstract

The invention belongs to the field of dyeing and finishing and specifically relates to a reactive dyeing process for black protein fibers based on coupling dyeing, comprising the following steps: chemical modification of the protein fibers with indigo carmine anhydride; diazotization of the resulting modified protein fibers with nitrite, yielding diazotized protein fibers; reaction of the diazotized protein fibers with an acidic solution containing coupling components, producing a colored substance with an azo structure. The black protein fibers dyed by the process according to the invention exhibit an excellent relative fixation rate of up to 95%; the dyed fibers possess excellent colorfastness and durability.

Description

Technical field

[0001] The invention belongs to the field of dyeing and finishing and specifically relates to a reactive dyeing process for black protein fibers based on coupling dyeing. Technical background

[0002] In the fashion and apparel industry, black is often an important color choice due to its classic and versatile qualities. Black textiles absorb almost all wavelengths of visible light and therefore more heat, making them ideal heat-retaining materials in cold environments. Ultraviolet light has shorter wavelengths and higher energy; long-term exposure can damage the skin, which is why black textiles offer protection for the skin by absorbing UV radiation.

[0003] Currently, reactive and acid dyes are commonly used to dye protein fibers such as silk and wool. Reactive dyes form covalent bonds with protein fibers, resulting in dyed textiles exhibiting good wash and rub fastness. However, reactive dyes require high temperatures and alkaline conditions during dyeing, which can damage protein fibers and reduce fiber strength. Acid dyes bind to fibers via weak interactions such as van der Waals forces, hydrogen bonds, and ionic bonds, resulting in poor wet fastness. Because black is a composite color, it is difficult to achieve a deep, intense black in protein fiber textiles using a single dye; a combination of several dyes is typically required.

[0004] The invention, patent number CN2023108126596, entitled "In-situ diazotization coupling staining process for indigo carmine anhydride-modified protein materials," is a patent previously applied for and granted by the inventive team. The process comprises a specific aromatic primary aamination of the protein materials with indigo carmine anhydride. The modified protein materials are then subjected to an in-situ diazotization reaction in a nitrite environment and subsequently reacted with specific coupling reagents under alkaline conditions. This reaction generates azo dyes in situ on the protein material, resulting in staining. The staining process is characterized by a reaction temperature close to room temperature and low energy consumption.

[0005] This patent uses the following two coupling components:

[0006] The green coupling component is H-acid derivative 2 with the structure:

[0007] The black coupling component is H-acid derivative 3 with the structure:

[0008] Exemplary embodiment 5 of the patent and the corresponding experiment 5 show: When using H-acid derivative 2, the dyed castor silk fabric has a deep green color.

[0009] Exemplary embodiment 6 of the patent and the corresponding experiment 6 show: When using H-acid derivative 3, the dyed wool fabric has a light black color. The decolorized dyed fabric has a K / S value of 16.5; the K / S value is an important indicator for measuring the dyeing depth. Therefore, a deep, intense black fabric cannot be obtained. Disclosure of the invention

[0010] The technical problem to be solved by the invention is to provide a reactive staining process for black protein fibers based on coupling staining.

[0011] To solve the aforementioned technical problem, the invention provides a reactive staining process for black protein fibers based on coupling staining, comprising the following steps: 1) Modification of protein fibers: Chemical modification of protein fibers with indigo carmine anhydride (converting aliphatic amino groups in the protein fibers into aromatic primary amino groups), resulting in modified protein fibers; wherein the amount of indigo carmine anhydride used is 7.5-8.5% (preferably 8%) of the mass of the protein fibers; 2) Diazotization: Diazotization of the modified protein fibers obtained in step 1) with nitrite, resulting in diazotized protein fibers; 3) Clutch discoloration: Reaction of the diazotized protein fibers obtained in step 2) with an acidic solution containing coupling components (concentration of coupling components 10 ± 1 mmol / L), producing a colored substance with an azo structure; wherein the bath ratio during coupling staining is 1:20-100 (i.e., protein fibers from step 1 : acidic solution containing coupling components = 1 g : 20-100 ml); where the pH of the acidic solution containing coupling components is 2 ± 0.2; where the coupling components are H-acid derivative 2 and H-acid derivative 3 respectively;

[0012] As an improvement to the reactive staining process according to the invention for black protein fibers based on coupling staining, step 3) is carried out as follows: Mixing the coupling components, HCl and water to form an acidic solution containing the coupling components, wherein the pH of the acidic solution containing the coupling components is 2 ± 0.2 and the concentration of the coupling components is 10 ± 1 mmol / L; Immerse the diazotized protein fibers obtained in step 2) into the acidic solution containing the coupling components while continuously shaking, at 0-35 °C (preferably room temperature) for 20-40 min to achieve staining; Subsequent soaping (removing various substances freely adsorbed on the protein fibers) and rinsing (to remove the soap solution) followed by drying (baking at 40-60 °C for 20-40 min) results in black protein fibers.

[0013] As a further improvement of the reactive dyeing process according to the invention for black protein fibers based on coupling discoloration, the soaping in step 3) is carried out as follows: Immersion of the dyed protein fibers in a soap solution using a bath ratio of 1:40-60 (i.e., 1 g of protein fibers with 40-60 ml of soap solution), cleaning at 50-70 °C for 20-40 min while shaking; Recipe for the soap solution: Sodium dodecylbenzenesulfonate 0.9-1.1 g / L, NaHCO3 0.9-1.1 g / L, balance water.

[0014] As a further improvement of the reactive staining process according to the invention for black protein fibers based on coupling staining, step 1) is carried out as follows: Soaking 1 g of protein fibers in 50 ± 5 ml of water, adjusting the pH to 8 ± 0.2 by adding Na2CO3 aqueous solution dropwise, then adding a DMF solution containing 0.075-0.085 g (preferably 0.08 g) of indigo carmine anhydride, shaking and modifying at room temperature for 15-25 min; Maintaining a pH of 8 ± 0.2 by adding Na2CO3 aqueous solution dropwise during the above-mentioned modification reaction, Subsequent removal and washing with clear water (to remove indigo carmine anhydride from the protein fibers); this yields modified protein fibers.

[0015] Explanation: DMF increases the solubility of indigo carmine anhydride and can improve equalization.

[0016] As a further improvement of the reactive staining process according to the invention for black protein fibers based on a coupling staining, the DMF solution, which contains 0.075-0.085 g (preferably 0.08 g) indigo carmine anhydride, consists of 0.075-0.085 g (preferably 0.08 g) indigo carmine anhydride and 2 ± 0.2 ml DMF.

[0017] The concentration of the Na2CO3 aqueous solution is 0.4-0.6 mol / L (preferably 0.5 mol / L).

[0018] As a further improvement of the reactive staining process according to the invention for black protein fibers based on coupling staining, step 2) is carried out as follows: Immerse the modified protein fibers from step 1) in a nitrite-water solution, stir and diazotize at room temperature for 15-25 min; wherein, per 1 g of protein fibers, the nitrite-water solution used consists of 5.6-6.0 mmol HCl, 0.23-0.27 mmol NaNO2 and 28-31 ml water; Subsequent removal, soaking and drying (baking at 40-60 °C for 20-40 min) results in diazotized protein fibers.

[0019] As a further improvement of the reactive dyeing process according to the invention for black protein fibers based on coupling dyeing, the protein fibers are silk (mulberry silk) or wool.

[0020] For the protein fibers obtained using the drawing-up method according to the invention, the tests of dry and wet rub fastness as well as soap fastness are carried out in accordance with the national standards customary in the field.

[0021] The invention utilizes the two coupling components mentioned in patent CN2023108126596 – the green coupling component (H-acid derivative 2) and the black coupling component (H-acid derivative 3) – for a coupling reaction with diazotized protein fibers under acidic conditions. By changing the coupling conditions, fabrics that initially appear green (G1) or light black (B1) are transformed into deep, intense black fabrics while the structure of the coupling components remains unchanged. This innovative process not only improves the dyeing effect but also enables the dyeing of fabrics to black with just a single coupling component, thereby increasing the market appeal of the dyed textiles.

[0022] The reactive staining process according to the invention for black protein fibers based on coupling staining has the following technical advantages: 1. The invention provides an innovative staining process that offers significant advantages compared to existing techniques for staining protein fibers with commercial black dyes. The process of the invention ensures a strong bond between the dye and the protein fibers through covalent bonds. Of particular importance is that the process of the invention achieves a deep, intense black staining result with only one coupling component, thereby simplifying the staining process and reducing costs. 2. The black protein fibers dyed using the inventive method exhibit an excellent relative fixation rate of up to 95%; the dyed fibers possess excellent colorfastness and durability. The dyeing process takes place under conditions near room temperature; this mild dyeing environment reduces damage to the protein fibers during the dyeing process and protects the natural structure and properties of the fibers. Presentation of the illustrations

[0023] The specific embodiments of the invention are explained in more detail below with reference to the drawings. Fig. shows the K / S curves as well as fabric sample images of the black mulberry silk fabric obtained in embodiment 1 and the decolorized black mulberry silk fabric; Fig.shows the K / S curves as well as fabric sample images of the black mulberry silk fabric obtained in embodiment 2 and the decolorized black mulberry silk fabric; Fig. shows the K / S curves as well as fabric sample images of the black mercerized wool fabric obtained in embodiment 3 and the decolorized black mercerized wool fabric; Fig. shows the K / S curves as well as fabric sample images of the black mercerized wool fabric obtained in embodiment 4 and the decolorized black mercerized wool fabric; Fig. shows the K / S curves as well as fabric sample images of the silk fabric obtained in comparison example 1 before and after bleaching; Fig. shows the K / S curves as well as fabric sample images of the wool fabric obtained in comparison example 2 before and after bleaching; Fig.shows the K / S curves as well as fabric sample images of the wool fabric obtained in comparison example 3 before and after bleaching; Fig. shows the comparison of the K / S curves of the wool fabrics obtained in embodiment 4 and comparison example 3 after decolorization. Specific examples of implementation

[0024] The invention will be further described below with reference to specific embodiments, the scope of protection of which is not limited to these: The room temperature of the invention refers to 20-30 °C (e.g. 25 °C).

[0025] Exemplary embodiment 1: A reactive staining process for black protein fiber tissue based on coupling staining, comprising the following steps sequentially: 1) Modification of protein fibers, i.e., modification of a mulberry silk tissue with indigo carmine anhydride: Soaking 1 g of mulberry silk tissue in 50 ml of water, adding Na2CO3 aqueous solution (0.5 mol / L) dropwise so that the pH of the solution is 8, then adding a DMF solution containing indigo carmine anhydride (0.08 g indigo carmine anhydride, 2 ml DMF), shaking and modifying at room temperature for 20 min; During the above-mentioned modification reaction, the pH of the reaction system is maintained at 8 by adding Na2CO3 aqueous solution (0.5 mol / L) dropwise; After completion of the modification reaction, the fabric is removed and washed with clear water (to remove indigo carmine anhydride from the mulberry silk fabric); thus, modified mulberry silk fabric is obtained. 2) Diazotization, i.e., diazotization of the modified mulberry silk tissue: Under room temperature conditions (25 °C), add 28 ml of water and 0.5 ml of hydrochloric acid-water solution (11.6 mol / L) to an Erlenmeyer flask, then add 1 ml of sodium nitrite solution (0.25 mol / L) to this hydrochloric acid-water solution, after stirring evenly, rapidly immerse the modified mulberry silk tissue obtained in step 1) into the above solution, shake for 20 min, remove excess nitrite with urea; then remove, wash with water, and dry in an oven at 50 °C for approximately 40 min, resulting in diazotized mulberry silk tissue. Explanation: Slow addition of urea; a drop is dabbed onto potassium iodide test paper and if it does not change color within 1-2 seconds, it indicates that excess nitrite has been removed. 3) Clutch discoloration: Selection of H-acid derivative 2 with the structural formula:

[0026] Adding 0.5 mmol of coupling component H-acid derivative 2 to 50 ml of water, adjusting the pH of the solution to 2 with hydrochloric acid-water solution (11.6 mol / L), thus obtaining an acidic solution containing the coupling components.

[0027] Immerse the diazotized modified mulberry silk fabric obtained in step 2) into the acidic solution containing the coupling components while continuously shaking. Shake at room temperature (25 °C) for 30 min to ensure a complete coupling reaction and dyeing.

[0028] After completion of the coupling reaction, remove the dyed silk fabric, rinse with clean water, and then soap and wash. The soap bath ratio is 1:50 (i.e., 1 g of mulberry silk with 50 ml of soap solution). The soap solution contains 1 g / L NaHCO3 and 1 g / L sodium dodecylbenzenesulfonate (the remainder being water). The soaping temperature is 60 °C, and the soaping time is 30 minutes. Wash with clean water at room temperature until the runoff is colorless (approx. 2 minutes), then dry in an oven at 50 °C for approx. 40 minutes. Black mulberry silk fabric (Black 1) is obtained.

[0029] Explanation: The above-mentioned soaping and washing serves to remove various substances that are freely adsorbed onto the fabric until the draining liquid is colorless; then the rinsing is stopped.

[0030] Test 1. The black mulberry silk fabric (Black 1) treated according to embodiment 1 is subjected to DMF bleaching; 1 g of black mulberry silk fabric (Black 1) is placed in 100 ml of DMF, heated to 100 °C, and bleached for 30 min; after bleaching is complete, the DMF is washed off the fabric with water, and the fabric is dried in an oven at 50 °C for 40 min; the bleached black mulberry silk fabric (Black 1 DMF-debleached) is tested according to "Wash fastness GB / T3921-2008" and "Rub fastness test GB / T 3920-2008": The K / S curves and fabric sample images of the black mulberry silk fabric (Black 1) and the bleached black mulberry silk fabric (Black 1 DMF-bleached) are in Fig. shown; in the curve, the wavelength of the point with the maximum K / S value of the fabric sample corresponds to 610 nm, the maximum K / S value of Black 1 is 16.5, the maximum K / S value of Black 1 DMF-decolorized is 16.1.

[0031] The dry rub fastness of the dyed fabric is 4-5, the wet rub fastness 4-5, the soap fastness 5, the relative fixation rate reaches 97.58%; it is evident that black fabrics dyed with this method exhibit excellent color fastness.

[0032] From the comparison of Black 1 and Black 1 DMF-decolorized in Fig. It is evident that a black dye was produced in situ on the silk; the dye forms covalent bonds with the silk and cannot be removed by DMF at high temperature.

[0033] Example 2: A reactive staining process for black protein fibers based on coupling staining: The 0.5 mmol H-acid derivative 2 in step 3) of embodiment 1 are replaced by 0.5 mmol H-acid derivative 3, otherwise identical to embodiment 1; black mulberry silk fabric (Black 2) is obtained. Structural formula of H-acid derivative 3:

[0034] Experiment 2. The black mulberry silk fabric (Black 2) treated according to embodiment 2 is subjected to DMF decolorization as described in Experiment 1; the decolorized black mulberry silk fabric (Black 2 DMF-decolorized) is tested as described in Experiment 1: The K / S curves and fabric sample images of the black mulberry silk fabric (Black 2) and the bleached black mulberry silk fabric (Black 2 DMF-bleached) are in Fig. As shown in the curve, the wavelength of the point with the maximum K / S value of the fabric sample corresponds to 610 nm, the maximum K / S value of Black 2 is 16.0, and the maximum K / S value of Black 2 DMF-decolorized is 15.1. The dry rub fastness of the dyed fabric is 4-5, the wet rub fastness is 4-5, the soap fastness is 5, and the relative fixation rate reaches 94.38%; it is evident that black fabrics dyed with this process exhibit excellent color fastness.

[0035] From the comparison of Black 2 and Black 2 DMF-decolorized in Fig. It is evident that a black dye was produced in situ on the silk; the dye forms covalent bonds with the silk and cannot be removed by DMF at high temperature.

[0036] Example 3: A reactive staining process for black protein fiber tissue based on coupling staining: The 1 g of mulberry silk fabric in step 1) of embodiment 1 is replaced by 1 g of mercerized wool fabric, otherwise identical to embodiment 1; black mercerized wool fabric (Black 3) is obtained.

[0037] Experiment 3. The black mercerized wool fabric (Black 3) treated according to embodiment 3 is subjected to DMF decolorization as described in Experiment 1; the decolorized black mercerized wool fabric (Black 3 DMF-decolorized) is tested as described in Experiment 1: The K / S curves and fabric sample images of the black mercerized wool fabric (Black 3) and the bleached black mercerized wool fabric (Black 3 DMF-bleached) are in Fig. As shown in the curve, the wavelength of the point with the maximum K / S value of the fabric sample corresponds to 610 nm, the maximum K / S value of Black 3 is 31, and the maximum K / S value of Black 3 DMF-decolorized is 29.5. The dry rub fastness of the dyed fabric is 4-5, the wet rub fastness is 4, the soap fastness is 5, and the relative fixation rate reaches 95.16%. It is evident that black fabrics dyed using this method exhibit excellent color fastness.

[0038] From the comparison of Black 3 and Black 3 DMF-decolorized in Fig. It is evident that a black dye was produced in situ on the wool; the dye forms covalent bonds with the wool and cannot be removed by DMF at high temperature.

[0039] Example 4: A reactive staining process for black protein fiber tissue based on coupling staining: The 1 g of mulberry silk fabric in step 1) of embodiment 2 is replaced by 1 g of mercerized wool fabric, otherwise identical to embodiment 2; black mercerized wool fabric (Black 4) is obtained.

[0040] Experiment 4. The black mercerized wool fabric (Black 4) treated according to embodiment 4 is subjected to DMF decolorization as described in Experiment 1; the decolorized black mercerized wool fabric (Black 4 DMF-decolorized) is tested as described in Experiment 1: The K / S curves and fabric sample images of the black mercerized wool fabric (Black 4) and the bleached black mercerized wool fabric (Black 4 DMF-bleached) are in Fig.The graph shows that in the curve, the wavelength of the point with the maximum K / S value of the fabric sample corresponds to 610 nm. The maximum K / S value of Black 4 is 27.7, and the maximum K / S value of Black 4 DMF-decolorized is 27.2. The dry rub fastness of the dyed fabric is 4-5, the wet rub fastness is 4, the soap fastness is 5, and the relative fixation rate reaches 98.19%. It is evident that black fabrics dyed using this method exhibit excellent color fastness.

[0041] From the comparison of Black 4 and Black 4 DMF-decolorized in Fig. It is evident that a black dye was produced in situ on the wool; the dye forms covalent bonds with the wool and cannot be removed by DMF at high temperature. Comparative example 1:

[0042] Dyeing of a mulberry silk fabric (identical to the original mulberry silk fabric used in embodiment 1) with a reactive dye according to a conventional dyeing process; the reactive dye used is Reactive Black 5 with the following structural formula:

[0043] The dyeing process is carried out according to the following procedure: dye mass concentration 2.5 g / L, sodium sulfate 60 g / L, sodium carbonate 30 g / L, bath ratio 1:20, immersion at 30 °C, heating at a specific rate to 70 °C (heating time 20 min), then holding at 70 °C for 60 min; after completion of the holding time, removal of the silk fabric, repeated soaping and rinsing, drying in an oven at 50 °C for 40 min; black mulberry silk fabric (Black 5) is obtained.

[0044] The black mulberry silk fabric (Black 5) treated according to comparison example 1 is subjected to DMF decolorization as described in experiment 1; the decolorized black mulberry silk fabric (Black 5 DMF-decolorized) is tested as described in experiment 1: The K / S curve of the silk fabric treated according to the method described in comparative example 1 is in Fig. shown; in the curve, the wavelength of the point with the maximum K / S value of the fabric sample corresponds to 580 nm, the maximum K / S value during dyeing is 16.1, the K / S value after bleaching is 15.0; the dry rub fastness of the dyed fabric is 4-5, the wet rub fastness is 4-5, the soap fastness is 5, the relative fixation rate reaches 93.17%.

[0045] Explanation: Changing the above-mentioned "staining temperature of 70 °C" to "staining temperature room temperature" would result in a significant reduction in both the staining depth and the uptake rate.

[0046] It is evident from this that the dyeing temperature required for this process is significantly higher than in the invention, and that energy consumption is high. Large quantities of alkali and salt must be added during the dyeing process. Furthermore, the fabric dyed using the invention exhibits stronger absorption in the short-wave range (broader absorption maximum), and the color tends more towards black. Comparative example 2

[0047] Dyeing of a mercerized wool fabric (identical to the original mercerized wool fabric used in embodiment 3) with a reactive dye according to a conventional dyeing process; the reactive dye used is Reactive Black 5.

[0048] The dyeing process is carried out according to the following procedure: dye mass concentration 2.5 g / L, sodium sulfate 60 g / L, sodium carbonate 30 g / L, bath ratio 1:20, immersion at 30 °C, heating at a specific rate to 70 °C (heating time 20 min), then holding at 70 °C for 60 min; after completion of the holding time, removal of the wool fabric, repeated soaping and rinsing, drying in an oven at 50 °C for 40 min; black mercerized wool fabric (Black 6) is obtained.

[0049] The K / S curve of the wool fabric treated according to the method described in comparative example 2 is in Fig.The graph shows the wavelength of the point with the maximum K / S value of the fabric sample at 570 nm. The maximum K / S value during dyeing is 29.8, and the K / S value after bleaching is 29.6. This is in accordance with the national standards "Wash fastness GB / T3921-2008" and "Rub fastness test GB / T 3920-2008". The dry rub fastness of the dyed fabric is 4-5, the wet rub fastness is 4, the soap fastness is 5, and the relative fixation rate reaches 99.33%.

[0050] Explanation: Changing the above-mentioned "staining temperature of 70 °C" to "staining temperature room temperature" would result in a significant reduction in both the staining depth and the uptake rate.

[0051] It is evident from this that the dyeing temperature required for this process is significantly higher than in the invention, and that energy consumption is high. Large quantities of alkali and salt must be added during the dyeing process. Furthermore, the fabric dyed using the invention exhibits stronger absorption in the short-wave range, and the color tends more towards black. Table 1 tissue Dyeing temperature, dyeing time Maximum K / S value after DMF decolorization Relative fixation rate (100%) Dry rub fastness Wet rub fastness Soap Trueness Example 1 Mulberry silk 25 °C, 70 min 16,1 97,58 4-5 4-5 5 Example 2 Mulberry silk 25 °C, 70 min 15,1 94,38 4-5 4-5 5 Example 3 mercerized wool 25 °C, 70 min 29,5 95,16 4-5 4 5 Example 4 mercerized wool 25 °C, 70 min 27,2 98,19 4-5 4 5 Comparative example 1 Mulberry silk 70 °C, 80 min 15,0 93,17 4-5 4-5 5 Comparative example 2 mercerized wool 70 °C, 80 min 29,6 99,33 4-5 4 5

[0052] Furthermore, the following comparisons were made during the invention process: Comparative example 3. Compared to step 3) of embodiment 4, the following changes are made: It is changed in step 3) according to CN2023108126596: Specifically: Mixing the black coupling component, sodium hydroxide, sodium carbonate and water to form a coupling component solution; in the coupling component solution the concentration of the black coupling component is 2 g / L, the concentration of sodium hydroxide is 0.2 g / L, and the concentration of sodium carbonate is 5 g / L.

[0053] While constantly shaking, immerse the diazotized mercerized wool fabric obtained in step 2) in 500 ml of the coupling component solution, allow the reaction to take place at room temperature for 30 min to achieve dyeing, then alternately wash with hot and cold water, and finally air dry; dyed mercerized wool fabric is obtained. Otherwise identical to embodiment 4.

[0054] The following test method is carried out according to test 4; the K / S curve of the wool fabric treated according to the procedure described in comparative example 3 is in Fig.The comparison with embodiment 4 is shown in Table 2 below: Table 2 Maximum K / S value after DMF decolorization Relative fixation rate (100%) Example 4 27,2 98,19 Comparative example 3 16,5 94,29

[0055] It is evident from this that the color depth value of the fabric dyed with the acid coupling dye according to the invention is significantly higher than that of the fabric dyed in the comparison example, and that in the invention the absorption in the range 350-650 nm exceeds 20 in each case, and that the K / S curve is smoother; the comparison of the two K / S curves is shown in Fig. depicted.

[0056] Finally, it should be noted that the embodiments listed above are merely some specific examples of the invention. Obviously, the invention is not limited to the embodiments mentioned above, but can have numerous variations. All variations that a person skilled in the art can directly derive or associate from the disclosed content of the invention are to be considered as belonging to the scope of protection of the invention. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] CN 2023108126596 [0004, 0021, 0052] Cited non-patent literature

[0000] GB / T3921-2008 [0030, 0049] GB / T 3920-2008 [0030, 0049]

Claims

[1] Reactive staining method for black protein fibers based on coupling staining, characterized by that it includes the following steps: 1) Modification of protein fibers: Chemical modification of protein fibers with indigo carmine anhydride, resulting in modified protein fibers; wherein the amount of indigo carmine anhydride used is 7.5-8.5% of the mass of the protein fibers; 2) Diazotization: Diazotization of the modified protein fibers obtained in step 1) with nitrite, resulting in diazotized protein fibers; 3) Clutch discoloration: Reaction of the diazotized protein fibers obtained in step 2) with an acidic solution containing coupling components, producing a colored substance with an azo structure; wherein the bath ratio for coupling staining is 1:20-100; where the pH of the acidic solution containing coupling components is 2 ± 0.2; where the coupling components are H-acid derivative 2 and H-acid derivative 3 respectively; [2] Reactive staining process for black protein fibers based on a coupling staining according to claim 1, characterized by , that step 3) is carried out as follows: Mixing the coupling components, HCl and water to form an acidic solution containing the coupling components, wherein the pH of the acidic solution containing the coupling components is 2 ± 0.2 and the concentration of the coupling components is 10 ± 1 mmol / L; Immerse the diazotized protein fibers obtained in step 2) into the acidic solution containing the coupling components while continuously shaking, at 0-35°C for 20-40 min to achieve staining; Subsequent soaping, rinsing and drying, which yields black protein fibers. [3] Reactive staining process for black protein fibers based on a coupling staining according to claim 2, characterized by , that the soaping in step 3) is carried out as follows: Immersion of the colored protein fibers in a soap solution using a bath ratio of 1:40-60, cleaning at 50-70°C for 20-40 min while shaking; Recipe for the soap solution: Sodium dodecylbenzenesulfonate 0.9-1.1 g / L, NaHCO3 0.9-1.1 g / L, balance water. [4] Reactive staining process for black protein fibers based on a coupling staining according to one of claims 1 to 3, characterized by , that step 1) is carried out as follows: Soaking 1 g of protein fibers in 50 ± 5 ml of water, adjusting the pH to 8 ± 0.2 by adding Na2CO3 aqueous solution dropwise, then adding a DMF solution with 0.075-0.085 g of indigo carmine anhydride, shaking and modifying at room temperature for 15-25 min; Maintaining a pH of 8 ± 0.2 by adding Na2CO3 aqueous solution dropwise during the above-mentioned modification reaction, Subsequent removal, washing with clear water, which yields modified protein fibers. [5] Reactive staining process for black protein fibers based on a coupling staining according to claim 4, characterized by , that: the DMF solution containing 0.075-0.085 g of indigo carmine anhydride consists of 0.075-0.085 g of indigo carmine anhydride and 2 ± 0.2 ml of DMF; where the concentration of the Na2CO3 water solution is 0.4-0.6 mol / L. [6] Reactive staining process for black protein fibers based on a coupling staining according to claim 5, characterized by , that step 2) is carried out as follows: Immerse the modified protein fibers from step 1) in a nitrite-water solution, stir and diazotize at room temperature for 15-25 min; wherein, per 1 g of protein fibers, the nitrite-water solution used consists of 5.6-6.0 mmol HCl, 0.23-0.27 mmol NaNO2 and 28-31 ml water; Subsequent removal, rinsing, and drying result in diazotized protein fibers. [7] Reactive staining method for black protein fibers based on coupling staining according to any one of claims 1 to 6, characterized by that the protein fibers are silk or wool.

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