Dyeing microcapsules and their use in the dyeing and finishing of machine washable silk

Abstract

The present application relates to a kind of dyed microcapsules and its application in the dyeing and finishing of machine washable real silk, belong to the technical field of microcapsule.The amino acid side chain that can produce strong hydrogen bond effect is introduced into capsule shell layer for the first time in the present application, the content of metal coordination bond, hydrogen bond is regulated, the crosslinking density of nanocapsule and silk is improved, and finally the preparation of persistent adhesive force nanocapsule is realized.Silk fibroin based on biological protein macromolecule is used as wall material and applied on silk, better combined with silk, and has good biocompatibility and hand feeling, wall material is prepared by emulsion polymerization method, and the core material is silk microcapsule dye of natural fungal dye, using post-mordanting technology, while dyeing real silk fabric, introduce curing agent, carry out wash-resistant finishing, so that the originally relatively fragile silk fabric can be machine washed.

Description

Technical Field

[0001] This invention relates to the field of microcapsule technology, and in particular to a dyeing microcapsule and its application in the dyeing and finishing of machine-washable silk. Background Technology

[0002] Silk fabric is made from pure mulberry silk and is categorized into thin, medium, and thick types based on its weight per square meter. It is also classified into dyed and printed types based on post-processing. It is characterized by its soft and smooth texture, gentle feel, lightness, rich and varied colors, and cool and comfortable wear. It is mainly used for summer shirts, pajamas, dresses, and headscarves, among other things. Known as the "Queen of Fibers" and "the second skin of the human body," it not only possesses a noble and flowing appearance but also boasts skin-care and health-promoting qualities, aligning with today's trend of green consumption. However, silk products have a serious drawback: machine washing can cause a decrease in color saturation and even whitening damage, significantly impacting the product's visual appeal and thus limiting its use.

[0003] Current finishing methods for machine-washable silk fabrics have many drawbacks. Silk is generally dyed with acid dyes or reactive dyes, with acid dyes typically having low colorfastness. Although color fading gradually decreases with repeated washing, poor colorfastness remains a concern in machine-washable silk dyeing technology. Microencapsulation dyeing is an advanced dyeing technology that combines microencapsulation technology with silk dyeing processes. Microencapsulation technology uses mechanical or chemical methods to encapsulate dyes in tiny capsules, which are then applied to the dyeing process of silk fibers. The core of this technology lies in using dyes as core materials to create microcapsules, which are then directly added to the dye bath during dyeing. Utilizing the concentration difference between the fiber, the dye bath, and the dye within the capsules, the dye is continuously released, adsorbed, and applied to the fiber, thus completing the dyeing process. However, microencapsulation technology is currently used less extensively in the research and development of machine-washable silk.

[0004] Chinese patent CN 116876214A discloses a finishing method for machine-washable silk fabric. It eliminates static electricity on the fabric surface using an antistatic agent, inhibits bacterial growth with an organosilicon quaternary ammonium salt antibacterial finishing agent, and reduces wrinkles during washing and drying using an anti-wrinkle agent. The coating is cured using a UV curing machine without damaging the functions of the antistatic agent, organosilicon quaternary ammonium salt antibacterial finishing agent, and anti-wrinkle agent. This method solves the problems of antistatic, antibacterial, and wrinkle-resistant properties of silk during machine washing, but it does not address issues such as color fading and poor colorfastness in machine-washable silk.

[0005] Chinese patent CN 113981713 A discloses a method for dyeing silk fabrics with natural dyes. The method involves immersing the silk fabric in natural dyes, then mordant-dyeing the fabric with a natural mordant to obtain naturally dyed silk fabric. A natural antioxidant is then mixed with gum arabic, and an emulsifier is added for dispersion and emulsification. This reaction produces natural antioxidant microcapsules. The naturally dyed silk fabric is placed in the natural antioxidant microcapsule solution, and a stable liquid-hold ratio is maintained through rolling before drying. However, this method suffers from limitations in dye selection and finishing properties such as wrinkle resistance.

[0006] Therefore, there is an urgent need to provide a method that can simultaneously satisfy both anti-wrinkle and enhanced color fastness. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention provides a dyeing and finishing method for machine-washable silk fabrics. This invention utilizes the sustained-release and encapsulation properties of microcapsule technology, introduces bio-protein polymers (silk fibroin) into the wall material, leverages post-mordant dyeing to improve dye utilization and color vibrancy, and utilizes nano-silica particles to modify the silk fibroin material.

[0008] This invention is achieved through the following technical solution:

[0009] The first objective of this invention is to provide a method for preparing stained microcapsules, comprising the following steps:

[0010] S1. Mix the aqueous solution of monomeric dopamine methacrylamide with the aqueous solution of regenerated silk fibroin, let stand, and spontaneously polymerize to obtain a dopamine methacrylamide-silk fibroin mixed solution.

[0011] S2. SiO2 nanoparticles are mixed with deionized water to obtain a SiO2 suspension; then a n-butanol solution containing natural dye, crosslinking agent and initiator is added to obtain a natural dye / SiO2 mixed solution.

[0012] S3. The obtained dopamine methacrylamide-silk fibroin mixed solution, natural dye / SiO2 mixed solution and emulsifier aqueous solution are mixed, and the dyed microcapsules are obtained after shearing and stirring.

[0013] In one embodiment of the present invention, in step S1, the concentration of dopamine methacrylamide in the aqueous solution of the monomeric dopamine methacrylamide is 5wt%-25wt%.

[0014] And / or, the concentration of regenerated silk fibroin in the aqueous solution is 30 mg / mL-40 mg / mL, preferably 36.0 mg / mL.

[0015] In one embodiment of the present invention, in step S2, the crosslinking agent is ethylene glycol dimethacrylate; the initiator is azobisisobutyronitrile; and the addition amount of both the crosslinking agent and the initiator is 5wt%-25wt%.

[0016] In one embodiment of the present invention, in step S2, the natural dye includes red yeast rice pigment and / or gardenia yellow; the amount of natural dye added to the natural dye / SiO2 mixed solution is 0.9%.

[0017] wt% - 1.5wt%.

[0018] In one embodiment of the present invention, in step S3, the emulsifier in the emulsifier aqueous solution is polyvinyl alcohol; the concentration of the emulsifier in the emulsifier aqueous solution is 1wt%-5wt%, preferably 1wt%-3wt%.

[0019] In one embodiment of the present invention, in step S3, the shearing speed is 10000rpm-16000rpm, preferably 10000rpm-14000rpm; and the time is 1min-12min.

[0020] A second objective of this invention is to provide dyed microcapsules obtained by the preparation method described above.

[0021] A third objective of this invention is to provide the application of the aforementioned dyeing microcapsules in the dyeing and finishing of machine-washable silk.

[0022] The fourth objective of this invention is to provide a method for dyeing and finishing machine-washable silk, characterized by comprising the following steps:

[0023] (1) Immerse the silk fabric in the dyeing solution containing dyeing microcapsules, raise the temperature at a uniform rate to 60℃-80℃ and hold for 30min-60min, and then lower the temperature at a uniform rate to 35℃-40℃, preferably 40℃.

[0024] (2) Add mordant and curing agent to the solution obtained in step (1), stir evenly, and then heat at a constant rate to 50℃-90℃, maintain for 30min-60min, and then cool at a constant rate to room temperature.

[0025] (3) The silk fabric obtained in step (2) is soaped and washed with water.

[0026] In one embodiment of the present invention, in step (1), the temperature of the dye solution is 60°C-80°C; and the pH value is 3-6.

[0027] In one embodiment of the present invention, in step (2), the mordant is selected from rare earth elements; the curing agent is FeCl3 and polybutyl acrylate; the amount of mordant added is 2%-6%; the amount of curing agent added is 2%-6%; the mass ratio of FeCl3 to polybutyl acrylate is 1:1-2.5:1; and the concentration of FeCl3 is 0.5mol / L-1.0mol / L.

[0028] In one embodiment of the present invention, in steps (1) and (2), the heating rate is 1℃ / min-3℃ / min; the cooling rate is 2℃ / min-5℃ / min.

[0029] The dyeing and finishing mechanism of this invention is as follows:

[0030] The wall material of the dye microcapsules of this invention contains silk fibroin, nano-silica particles, and polydopamine methacrylamide. By encapsulating the dye in the microcapsules, efficient and uniform dyeing of silk is achieved. This ensures that the dye fully penetrates the interior of the silk fibers, resulting in a uniform and long-lasting dyeing effect. During the post-mordant dyeing process, a curing agent metal ion is introduced. While the dye is released and dyeing the silk fabric, the synergistic effect of the metal coordination bonds and hydrogen bonds of the catechol groups enhances the long-lasting adhesion of the nano-silica particles, silk fibroin, and pigments to the surface of the silk fabric, thereby enhancing its wash resistance. The introduction of the soft monomer butyl acrylate increases the softness of the nanocapsules, thus increasing their viscosity and further enhancing their long-lasting adhesion and wash resistance to the silk surface. Therefore, the silk fabric of this invention, through the dye microcapsule and post-mordant dyeing method, not only has more vibrant colors and is less prone to fading, but also retains its original color even after multiple washes and wears.

[0031] The technical solution of the present invention has the following advantages over the prior art:

[0032] (1) Red yeast rice pigment is a natural pigment produced by fermentation of Monascus purpureus and has high safety. Encapsulated in microcapsules, it is used for dyeing silk fabrics. The red hue of red yeast rice pigment is naturally bright and has a better visual effect compared to other natural colorants. Red yeast rice pigment is characterized by pH stability, heat resistance, light resistance, oxidation and reduction resistance, and resistance to metal ions, maintaining a stable color under different environments. It also has strong antibacterial and antimicrobial properties, effectively inhibiting bacterial growth on the surface of silk fabrics. Currently, red yeast rice pigment is widely used in the food and life science fields, but its application in textile dyeing is less studied. Using red yeast rice pigment to dye silk enriches the variety of natural dyes for textiles and meets the "green, environmentally friendly, energy-saving, and emission-reducing" principles advocated by the printing and dyeing industry.

[0033] (2) Microencapsulation dyeing technology exhibits a series of unique advantages when applied to silk dyeing. Microencapsulation dyeing technology achieves efficient and uniform dyeing of silk by encapsulating natural dyes (red yeast rice pigment) in microcapsules. This technology ensures that the dye fully penetrates the silk fibers, resulting in a uniform and long-lasting dyeing effect. Secondly, the encapsulation effect of microcapsules not only protects the dye but also improves the durability of the dyeing process. Silk dyed with microcapsules has more vibrant colors, is less prone to fading, and retains its original color even after multiple washes and wears. Furthermore, microencapsulation dyeing technology is environmentally friendly and energy-saving. By controlling the release of dye, this technology reduces dye waste during the dyeing process, thereby reducing environmental pollution. Simultaneously, microencapsulation dyeing technology can simplify the process flow, reduce energy consumption, and improve production efficiency.

[0034] (3) The unique structure and excellent properties of nano-silica: Nano-silica is a white and almost non-biotoxic inorganic nanoparticle with low cost, good mechanical properties, high thermal stability and strong ultraviolet shielding ability. Its surface has various forms of hydroxyl groups, which can easily interact with other substances with chemical groups, making it an excellent nanomaterial. Nano-silica is coated onto the surface of silk fabric to prepare multifunctional silk fabric, which improves the washability, UV resistance and wrinkle resistance of silk fabric.

[0035] (4) The red yeast rice pigment dye microcapsules prepared in this invention contain silk fibroin, nano silica particles, and polydopamine methacrylamide in their wall material. During the post-mordant dyeing process, curing agent metal ions are introduced. While the red yeast rice pigment is released to dye the silk fabric, the metal coordination bond and hydrogen bond of the catechol group are used to enhance the long-lasting adhesion of nano silica particles, silk fibroin, pigments, etc. on the surface of the silk fabric to enhance its washability. Attached Figure Description

[0036] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein...

[0037] Figure 1 This is a flowchart illustrating the preparation process of machine-washable silk based on microcapsule dyeing and finishing according to the present invention. Detailed Implementation

[0038] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0039] The purpose of this invention is to prepare a machine-washable silk fabric with high wrinkle resistance and colorfastness. The process includes the following steps:

[0040] Preparation of SiO2 nanoparticles: SiO2 nanoparticles were prepared by the sol-gel method. Deionized water and anhydrous ethanol were mixed at a certain speed for 5 min with a magnetic stirrer. A certain amount of ammonia was added for the experiment, followed by stirring for 10 min. Finally, tetraethyl orthosilicate (TEOS) was added. The mixture was stirred at 600 rpm for 45 min at room temperature. After the reaction was completed, the mixture was immediately centrifuged and washed 5 times, and then vacuum dried for 12 h (55℃, 0.8 MPa).

[0041] S2. Preparation of Regenerated Silk Fiber Aqueous Solution: Clean the silk waste and cut it into short pieces. Squeeze out excess water and vacuum dry at 50℃. Then add it to 0.02M Na2CO3 aqueous solution and boil for 30 minutes to degumme, repeating 3 times. Then wash it 3 times in clean water, squeeze out the water and dry to obtain refined silk fiber (DSF). Weigh 10.0g of DSF and add 100mL of 9.3M LiBr aqueous solution, incubate at 60℃ for 4 hours to obtain a pale yellow viscous liquid. Remove any insoluble matter by suction filtration, transfer the filtrate to a dialysis bag (molecular weight cutoff 8000-14000), and dialyze in 1.60L of deionized water for 3 days (changing the water every 4 hours). Centrifuge the dialyzed solution for 20 minutes (4℃, 8000rpm) to remove residues to obtain an 8.00wt.% RSF solution. Concentrate or dilute the RSF solution appropriately and store at 4℃ for later use.

[0042] S3. Preparation of emulsifier mixed solution: Dissolve the emulsifier polyvinyl alcohol (PVA) in deionized water to obtain a mixed solution. The content of polyvinyl alcohol (PVA) is 1%-5% (total system mass is 10g).

[0043] S4. Preparation of dopamine methacrylamide-silk fibroin mixed solution: Add the aqueous solution of monomeric dopamine methacrylamide (DMA) to the aqueous solution of RSF, mix well, and let stand at 25°C for two days to allow the dopamine in the solution to spontaneously polymerize, thereby causing browning.

[0044] S5. Preparation of red yeast rice pigment / SiO2 mixed solution: SiO2 nanoparticle powder was placed in deionized water and ultrasonically dissolved to prepare a 1.70 wt% SiO2 suspension. Then, 0.910 wt% red yeast rice pigment was added, followed by the addition of ethylene glycol dimethacrylate (EGDMA) and the initiator azobisisobutyronitrile (AIBN) dissolved in n-butanol to obtain a mixed solution.

[0045] S6. Preparation of Red Yeast Rice Pigment Microcapsules: The three solutions S3, S4, and S5 above were mixed evenly and dispersed by high-speed shearing using a high-speed shear homogenizer to form an emulsion. The resulting emulsion was stirred at a constant temperature in a magnetically stirred water bath. As the reaction proceeded, under the action of the crosslinking agent EGDMA and the initiator AIBN, the dopamine methacrylamide monomers formed polymer chains and crosslinked to form a polymer layer, ultimately forming red yeast rice pigment microcapsules.

[0046] S7. Prepare a dye bath containing dyeing microcapsules, heat a water bath, adjust the pH with acetic acid, and then completely immerse the silk fabric in the dye bath.

[0047] S8. Heat the dye solution at a constant rate until it reaches the dyeing temperature. After holding the temperature for a certain period of time, cool the solution at a constant rate until it reaches 40°C.

[0048] S9. Add rare earth mordant, stir evenly, and heat the dye solution by uniformly raising the temperature. After heating to the dyeing temperature, maintain the temperature for a certain period of time, and then cool the dye solution by uniformly lowering the temperature until it reaches room temperature.

[0049] S10. Post-treatment of dyed silk fabrics: First, soap them with a neutral detergent, and then wash them with water at a certain temperature.

[0050] In one embodiment of the present invention, the ratio of deionized water to anhydrous ethanol in S1 is 1:7.

[0051] In one embodiment of the present invention, the rotation speed of the magnetic stirrer in S1 is 400rpm-800rpm.

[0052] In one embodiment of the present invention, the amount of ammonia added in S1 is 1.00 mL to 3.00 mL.

[0053] In one embodiment of the present invention, the amount of tetraethyl orthosilicate (TEOS) added in S1 is 1.00 mL to 5.00 mL.

[0054] In one embodiment of the present invention, the average length of the short piece in S2 is 100 mm.

[0055] In one embodiment of the present invention, the dialysis bag described in S2 has a molecular weight cutoff of 8000-14000.

[0056] In one embodiment of the present invention, the emulsifier content examined in S3 accounts for 1%-5% of the system mass (10g).

[0057] In one embodiment of the present invention, the RSF aqueous solution in S4 is 36.0 mg / mL.

[0058] In one embodiment of the present invention, the amount of red yeast rice pigment in S5 is 0.910 wt.%.

[0059] In one embodiment of the invention, the homogenization duration in S6 is 1 min to 12 min. The homogenization rate is 10000 rpm to 16000 rpm.

[0060] In one embodiment of the present invention, the water bath in step S7 is heated to 40°C, and the dyeing solution is a dye containing red yeast rice microcapsules (liquor ratio 20:1-40:1).

[0061] In one embodiment of the present invention, the pH adjustment range in S7 is 3-6.

[0062] In one embodiment of the present invention, the heating rate in step S8 is 1°C / min, and after heating to the desired staining temperature, the heating is stopped and maintained for 50 minutes. The cooling rate is 2°C / min to cool down to 40°C.

[0063] In one embodiment of the present invention, the amount of rare earth mordant used in S9 is 2%-6%, the heating rate is 1℃ / min, and after heating to the dyeing temperature of 50℃-90℃, the heating is stopped and maintained for 50min. The cooling rate is 2℃ / min.

[0064] Unless otherwise specified, the experimental methods used in the embodiments and comparative examples of this invention are conventional methods, and the materials and reagents used are commercially available unless otherwise specified. Information on the commercial availability of some materials is as follows:

[0065] Tetraethyl orthosilicate (TEOS) was purchased from Shanghai Xiangu Chemical Co., Ltd., model number 432565;

[0066] Anhydrous ethanol was purchased from Shandong Haoyao New Materials Co., Ltd., model number HY546654;

[0067] The ammonia solution was purchased from Shanghai Titan Technology Co., Ltd., and the product grade was analytical grade.

[0068] The silk waste comes from Dali International Group;

[0069] Lithium bromide was purchased from Shanghai Oujin Industrial Co., Ltd., and the product grade was analytical grade, with CAS number 7550-35-8.

[0070] The red yeast rice pigment was purchased from Shandong Chunfuyuan Biotechnology Development Co., Ltd., model number TY001, item number T001;

[0071] The rare earth mordant (praseodymium chloride) was purchased from Zibo Guanhai Industry and Trade Co., Ltd., with a particle size of 100 and a product grade of industrial grade.

[0072] Example 1

[0073] Reference Figure 1 As shown, this embodiment of machine-washable silk based on microcapsule dyeing and finishing specifically includes the following steps:

[0074] Preparation of SiO2 nanoparticles: SiO2 spheres were prepared by the sol-gel method. Deionized water and anhydrous ethanol (1:7 ratio) were mixed at 600 rpm for 5 min with a magnetic stirrer. 2.5 mL of ammonia was added for the experiment, followed by stirring for 10 min. Finally, 4 mL of tetraethyl orthosilicate (TEOS) was added. The mixture was stirred at 600 rpm for 45 min at room temperature. After the reaction was completed, the mixture was immediately centrifuged and washed 5 times, and then vacuum dried for 12 h (55℃, 0.8 MPa) to obtain SiO2 nanoparticles.

[0075] S2. Preparation of Regenerated Silk Fiber Aqueous Solution: Silk waste was washed three times and then cut into short pieces with an average length of 100 mm. Excess water was squeezed out, and the mixture was vacuum dried at 50°C. It was then added to a 0.02 M Na₂CO₃ aqueous solution and boiled for 30 min to degumme, repeated three times. The mixture was then washed three times in clean water, squeezed dry, and dried to obtain refined silk fiber (DSF). 10.0 g of DSF was weighed and added to 100 mL of a 9.3 M LiBr aqueous solution. The solution was incubated at 60°C for 4 hours to obtain a pale yellow viscous liquid. Any insoluble matter was removed by suction filtration. The filtrate was transferred to a dialysis bag (molecular weight cutoff 8000-14000) and dialyzed in 1.60 L of deionized water for three days (changing the water every 4 hours). The dialyzed solution was centrifuged for 20 min (4°C, 8000 rpm) to remove residues, yielding an 8.00 wt.% RSF solution. The RSF solution was appropriately concentrated or diluted and stored at 4°C for later use.

[0076] S3. Preparation of emulsifier mixed solution: Dissolve the emulsifier polyvinyl alcohol (PVA) in deionized water to obtain an emulsifier mixed solution with a polyvinyl alcohol content of 3%, wherein the total mass of the emulsifier mixed solution is 10g.

[0077] S4. Preparation of dopamine methacrylamide-silk fibroin mixed solution: 25.0 mg / mL of monomeric dopamine methacrylamide (DMA) aqueous solution was added to RSF aqueous solution with a concentration of 36.0 mg / mL. After mixing, the solution was left to stand at 25°C for two days to allow the dopamine in the solution to spontaneously polymerize, thereby causing browning and obtaining dopamine methacrylamide-silk fibroin mixed solution.

[0078] S5. Preparation of Red Yeast Rice Pigment / SiO2 Mixed Solution: SiO2 nanoparticle powder was placed in deionized water and ultrasonically dissolved to prepare a 1.70 wt% SiO2 suspension. Subsequently, 0.910 wt% red yeast rice pigment was added, followed by the crosslinking agent ethylene glycol dimethacrylate (EGDMA) and the initiator azobisisobutyronitrile (AIBN) dissolved in n-butanol to obtain a mixed solution; wherein the mass ratio of crosslinking agent to initiator was 1.25:1.

[0079] S6. Preparation of Red Yeast Rice Pigment Microcapsules: The three solutions S3, S4, and S5 were mixed evenly in a 1:1:1 ratio and homogenized using a high-speed shear homogenizer at 13,000 rpm for 4 minutes to form an emulsion. The resulting emulsion was then subjected to magnetic stirring in a water bath at 40°C. As the reaction proceeded, under the action of the crosslinking agent EGDMA and the initiator AIBN, dopamine methacrylamide monomers formed polymer chains and crosslinked to form a polymer layer, ultimately forming red yeast rice pigment microcapsules.

[0080] S7. Mix the red yeast rice pigment microcapsules prepared in S6 with water to prepare a dye solution containing red yeast rice pigment microcapsules (5 mg / mL). -1 Heat the water bath to 40°C, adjust the pH to 4 with acetic acid, and then completely immerse the silk fabric in the dye bath.

[0081] S8. Heat the dye solution at a constant rate (heating rate of 1℃ / min) to a dyeing temperature of 80℃, hold for 50 minutes, and then cool it down at a constant rate (cooling rate of 2℃ / min) to dissipate heat and cool it down to 40℃.

[0082] S9. Add rare earth mordant, 1.0 mol / L curing agent FeCl3 and soft polymer polybutyl acrylate (mass ratio 1.2:1.5:1.25), stir evenly, and heat the dye solution at a uniform rate (heating rate of 1℃ / min) until it reaches the dyeing temperature of 80℃. After holding the temperature for 50 min, cool the dye solution at a uniform rate (cooling rate of 2℃ / min) until it reaches room temperature.

[0083] S10. Post-treatment of dyed silk fabrics: First, soap them with a neutral detergent, then wash them with water at room temperature.

[0084] Example 2

[0085] The scheme in this embodiment is basically the same as that in embodiment 1, except that in step S3, the content of emulsifier PVA is reduced from 3% of the system mass (10g) to 1%.

[0086] Example 3

[0087] The scheme in this embodiment is basically the same as that in embodiment 1, except that in step S6, the homogenization rate is reduced from 13000 rpm to 10000 rpm.

[0088] Example 4

[0089] The scheme in this embodiment is basically the same as that in embodiment 1, except that in step S6, the cutting time is reduced from 4 min to 2 min.

[0090] Example 5

[0091] The scheme in this embodiment is basically the same as that in embodiment 1, except that in step S9, the concentration of the curing agent FeCl3 is reduced from 1.0 mol / L to 0.5 mol / L.

[0092] Comparative Example 1

[0093] The scheme of this comparative example is basically the same as that of Example 1, except that the staining method is changed from post-mordant staining to no mordant staining. The specific method is as follows:

[0094] First, heat the water bath to 40°C, then add 2 mg / ml of solution at a specific bath ratio. -1 Microencapsulated dyes are prepared and the pH value is adjusted to the required value with acetic acid. The mixture is stirred evenly with a glass rod and then placed into the silk fabric. Stirring is continued with a glass cup until the fabric is completely immersed in the dye solution. The dye solution is then heated at a rate of 1℃ / min until the required dyeing temperature is reached. The heating is then stopped and maintained for 100 minutes. Finally, the dye solution is cooled at a rate of 2℃ / min. After the water bath temperature has cooled to room temperature, the dyed wool fabric is rinsed 2-3 times with tap water and then air-dried.

[0095] Comparative Example 2

[0096] The scheme of this comparative example is basically the same as that of Example 1, except that in step S9, the mordant is replaced from rare earth to stannous sulfate.

[0097] Comparative Example 3

[0098] The scheme of this comparative example is basically the same as that of Example 1, except that: instead of using microencapsulation technology to encapsulate the red yeast rice pigment, red yeast rice powder is added directly.

[0099] Comparative Example 4

[0100] The scheme of this comparative example is basically the same as that of Example 1, except that no nano-silica particles are added for finishing.

[0101] Comparative Example 5

[0102] The scheme of this comparative example is basically the same as that of Example 1, except that in step S3, the emulsifier (PVA) is replaced with castor oil polyoxyethylene ether.

[0103] Comparative Example 6

[0104] The scheme of this comparative example is basically the same as that of Example 1, except that the soft polymer polybutyl acrylate is not added in step S6.

[0105] Test Example 1

[0106] In particulate matter analysis, the polydispersity index (PDI) is an important parameter used to describe the distribution of particle size in particulate matter. PDI is a quantitative indicator of particle size distribution in particulate matter. The PDI value typically ranges from 0 to 1. A value closer to 0 indicates a more uniform particle size distribution and smaller size differences between particles; conversely, a value closer to 1 indicates a more uneven particle size distribution and greater size differences between particles. Particle size (nm) and PDI were tested for Examples 1, 2, 3, 4, and Comparative Example 5, and the results are shown in Table 1.

[0107] Table 1

[0108]

[0109] As can be seen from Table 1, reducing the emulsifier content, decreasing the homogenization rate, decreasing the shear time, and changing the type of emulsifier will all increase the particle size and dispersibility index to varying degrees.

[0110] Particle size and dispersibility index are closely related to dyeing, jointly influencing the dyeing performance, dyeing effect, and stability of the dyeing process. Smaller particle size allows pigment particles to be distributed more evenly on the fiber surface, thus improving the coloring effect of dyed products. Smaller pigment particles diffuse and penetrate more easily between fibers, resulting in a more uniform dyeing effect. Conversely, larger pigment particles may have difficulty penetrating fully into the fiber interior during the dyeing process, leading to uneven dyeing. Smaller pigment particles have higher reactivity and faster diffusion rates during the dyeing process, thus shortening dyeing time and improving dyeing efficiency. At the same time, smaller particle size also helps to improve the stability of the dyeing process, reducing problems such as color difference and color spots. Pigment particles with good dispersibility can be distributed more evenly on the fiber surface and inside, thus achieving a more uniform dyeing effect. Conversely, pigment particles with poor dispersibility are prone to agglomeration and precipitation during the dyeing process, leading to problems such as uneven dyeing and color spots. Pigment particles with good dispersibility bind more tightly to the fiber, improving the color fastness of dyed products. Under external conditions such as washing and friction, pigment particles with good dispersibility are not easily detached or faded.

[0111] Test Example 2

[0112] The standards for testing the color fastness of fabrics are shown in Table 2:

[0113] Table 2

[0114]

[0115] The color fastness of Examples 1 and 5 and Comparative Examples 1-4 was measured, and the test results are shown in Table 3:

[0116] Table 3

[0117]

[0118]

[0119] As shown in Table 3, reducing homogenization time, changing the dyeing method, changing the type of mordant, not using microencapsulation, and not adding nano-silica all reduce color fastness. Reducing homogenization time increases particle size and dispersibility. Compared to Example 1, smaller particle size helps improve color strength and dyeing uniformity during dyeing, while good dispersibility ensures that pigment particles remain evenly distributed during the dyeing process, improving dyeing uniformity and fastness. After using a mordant, the bond between the dye and the fiber is stronger, making the dyed fabric less prone to fading under external factors (such as compression, friction, washing, and sun exposure). This is because the mordant forms stronger chemical bonds with the dye and fiber, improving the dye's color fastness to washing, light, and rubbing. Mordants can increase the amount of dye adsorbed on the fiber and make its distribution more uniform, thereby improving dyeing uniformity and color fastness. Nano-silica has a three-dimensional network structure, a large specific surface area, and exhibits great activity. These properties enable nano-silica to play multiple roles in textile finishing, including enhancing dye adsorption, improving dyeing uniformity, and enhancing the physical and chemical properties of fiber surfaces. The addition of nano-silica can strengthen the bond between dyes and fibers, reducing dye loss and fading during washing and rubbing, thereby improving the colorfastness of textiles. It is particularly effective in improving wash fastness and rubbing fastness.

[0120] Test Example 3

[0121] According to GB / T 3819-1997 "Determination of Crease Recovery of Textiles", the crease recovery angle of silk fabric was tested. First, a triangular sample was cut according to the test requirements. Then, a fully automatic digital fabric crease elasticity meter was used to test the crease recovery angle of the fabric. The sample size was 40×15mm, the load was 10N, the pressure area was 20×15mm, and the pressure time was 300s. The average of 5 warp measurements and the average of 5 weft measurements were taken. Then, the warp and weft averages were added together to obtain WRA(W+F), which was used to measure the wrinkle resistance of the fabric. The wrinkle resistance of Examples 1 and 5 and Comparative Examples 3, 4, and 6 were tested, and the test results are shown in Table 4.

[0122] Table 4

[0123]

[0124] As shown in Table 4, reducing homogenization time, not using microencapsulation, not using nano-silica finishing, and not adding the soft polymer polybutyl acrylate all affect the wrinkle resistance of fabrics. Wrinkle resistance can be understood as the ability of a fabric to gradually return to its initial state after the external force causing its deformation disappears, due to the fabric's rapid and slow elasticity. The crease recovery angle is usually used to represent the crease recovery ability of a fabric. During testing, a sample of a certain shape and size is folded and compressed under specified conditions for a certain time. After the load is removed, the sample is allowed to recover for a certain period of time, and then the angle formed between the two wings is measured. The measured angle represents the crease recovery ability of the fabric. A larger crease recovery angle indicates better crease recovery, i.e., better wrinkle resistance. Nano-silica has a three-dimensional network structure and a large specific surface area, exhibiting extremely high activity. These properties allow nano-silica to play a variety of roles in textile finishing, including forming strong chemical bonds with fibers and enhancing the mechanical properties of fibers. Nano-silica finishing can also enhance the mechanical properties of fibers, such as breaking strength and elongation at break. These improvements in mechanical properties help fabrics better resist deformation and wrinkling when subjected to external forces.

[0125] The above results show that the finished product of the embodiments of the present invention has better color fastness, dyeing performance, and wrinkle resistance. Reducing the amount of added ammonia, increasing the homogenization rate, reducing the emulsifier content, increasing the homogenization time, and decreasing the amount of curing agent all lead to a decline in the performance of the product in various aspects. In the comparative examples, changing the dyeing method, replacing the mordant, not using microencapsulation technology, removing the addition of nano-silica, changing the type of emulsifier, and not adding the soft polymer polybutyl acrylate all resulted in varying degrees of decline in the performance of the product.

[0126] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A process for the preparation of dyed microcapsules, characterized in that, The method comprises the following steps: S1, mixing monomer dopamine methacrylamide aqueous solution and regenerated silk fibroin aqueous solution, standing, and obtaining dopamine methacrylamide-silk fibroin mixed solution after spontaneous polymerization; S2, mixing SiO2 nanoparticles and deionized water to obtain SiO2 suspension; then adding n-butanol solution containing natural dye, crosslinking agent and initiator to obtain natural dye / SiO2 mixed solution; S3, mixing the obtained dopamine methacrylamide-silk fibroin mixed solution, natural dye / SiO2 mixed solution and emulsifier aqueous solution, and obtaining the dyeing microcapsule after shearing and stirring.

2. The production method according to claim 1, characterized by, In step S1, the concentration of dopamine methacrylamide in the monomer dopamine methacrylamide aqueous solution is 5wt%-25wt%; And / or, the concentration of regenerated silk fibroin in the regenerated silk fibroin aqueous solution is 30mg / mL-40mg / mL.

3. The preparation method according to claim 1, characterized in that, In step S2, the crosslinking agent is ethylene glycol dimethacrylate; the initiator is azobisisobutyronitrile; and the addition amount of the crosslinking agent and the initiator is 5wt%-25wt%.

4. The method of claim 1, wherein, In step S2, the natural dye includes red rice pigment and / or gardenia yellow; And / or, the addition amount of the natural dye in the natural dye / SiO2 mixed solution is 0.9wt%-1.5wt%. In step S3, the emulsifier in the emulsifier aqueous solution is polyvinyl alcohol; and the concentration of the emulsifier in the emulsifier aqueous solution is 1wt%-5wt%.

5. The method of claim 1, wherein, In step S3, the shearing speed is 10000rpm-16000rpm; and the time is 1min-12min.

6. The method of claim 1, wherein, 7. The dyeing microcapsule obtained by the preparation method in any one of claims 1-6.

8. The application of the dyeing microcapsule in claim 7 in the dyeing and finishing of machine-washable real silk. The method comprises the following steps:

9. A method of dyeing and finishing machine washable pure silk characterized in that, (1) immersing real silk fabric in a dyeing solution containing dyeing microcapsules, uniformly heating to 60℃-80℃ and maintaining for 30min-60min, and then uniformly cooling to 35℃-40℃; (2) adding mordant and curing agent to the solution obtained in step (1), uniformly stirring, uniformly heating to 50℃-90℃, maintaining for 30min-60min, and then uniformly cooling to room temperature; (3) performing soaping and washing on the real silk fabric obtained in step (2). In step (1), the temperature of the dyeing solution is 60℃-80℃; and the pH value is 3-6; 10. The method of claim 9, wherein, And / or, in step (2), the mordant is selected from rare earth; and the addition amount of the mordant is 2%-6%; And / or, the curing agent is FeCl3 and polybutyl acrylate; and the addition amount of the curing agent is 2%-6%; And / or, in step (1) and step (2), the heating rate is 1℃ / min-3℃ / min; and the cooling rate is 2℃ / min-5℃ / min. ​

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