Anti-laddering anti-pilling dyeing and finishing method of figured island microfiber polyurethane synthetic leather

Abstract

The invention discloses an anti-laddering anti-pilling dyeing and finishing method of figured island microfiber polyurethane synthetic leather, which is characterized in that wear-resistant nano cellulose whiskers and a temperature-sensitive closed waterborne polyurethane cross-linking agent are innovatively introduced as key functional assistants, and a multi-stage function coordination and precise time sequence control process is adopted to prepare the anti-laddering anti-pilling dyeing and finishing method of figured island microfiber polyurethane synthetic leather. According to the synthetic leather and the preparation method thereof, through the synergistic effect of multiple components and sequential function design, the fuzzing and pilling resistance (4-5 levels) and the wear resistance are improved by 50%, the high unification of the soft hand feeling is achieved, the wear resistance, the yellowing resistance and the color fastness are remarkably improved, and the synthetic leather is suitable for industrial production. The industrial problems of silicon spots, dyeing defects, yellowing and the like which are easily generated due to the addition of a traditional organic silicon auxiliary agent are effectively avoided, and the industrial application value is remarkable.

Description

Technical Field

[0001] This invention belongs to the field of synthetic leather manufacturing technology, specifically relating to a dyeing and finishing method for preventing fraying and pilling of island-type microfiber polyurethane synthetic leather. Background Technology

[0002] Microfiber islanded polyurethane synthetic leather is widely used in high-end footwear, furniture, and bags due to its appearance and feel closely resembling genuine leather and its excellent mechanical properties. However, compared to non-islanded microfiber polyurethane synthetic leather, islanded microfiber synthetic leather is prone to fraying and pilling during wear and use due to the coarser island fibers, insufficient cohesion, and high strength. This can lead to the fibers easily detaching from the leather surface due to friction, further entanglement, and the formation of fuzz balls, severely affecting the product's appearance and durability.

[0003] Currently, the main methods to improve the anti-pilling performance of synthetic leather include: (1) physical methods: such as removing surface hairs through sanding, shearing, lubrication and other finishing processes, but this method has a short effect and damages the base fabric. (2) chemical methods: mainly using polymer resins (such as polyurethane, polyacrylate) for surface bonding finishing. However, traditional resin finishing often has the following drawbacks: First, excessive cross-linking in pursuit of high anti-pilling properties leads to stiffness and loss of softness in synthetic leather; Second, finishing agents are not easy to penetrate into the interior of microfibers, only forming a film on the surface, resulting in poor durability and functional degradation after repeated friction; Third, finishing agents may conflict with dyes and auxiliaries in subsequent dyeing processes, leading to uneven dyeing or functional failure. In addition, some studies have attempted to introduce nanomaterials or bio-based auxiliaries, but they often face problems such as high cost, complex processes, low industrialization feasibility or poor compatibility with existing systems.

[0004] Therefore, developing a simple and environmentally friendly finishing method that can deeply penetrate, prevent pilling and fraying while maintaining a soft hand feel, and synergize with the dyeing process is of great significance to the technological development of this field and is also a technical problem that the industry urgently needs to solve. Summary of the Invention

[0005] In view of the problems existing in the prior art, the purpose of this invention is to provide a high-efficiency, environmentally friendly, and mass-producible dyeing and finishing method for anti-snagging and anti-pilling of island-type microfiber polyurethane synthetic leather.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: A dyeing and finishing method for preventing fraying and pilling in island-type microfiber polyurethane synthetic leather includes the following steps: S1. Fiber swelling pretreatment: The island microfiber polyurethane synthetic leather is immersed in treatment solution 1 for treatment, and then thoroughly washed with water after treatment; S2. Anti-pilling resin treatment: The sample treated in step S1 is immersed in treatment solution 2 for padding; S3. Wet homogenization treatment: The wet sample after step S2 is processed by a vibrating loose water washing machine or a swinging rubbing machine. During the treatment, the sample is made to come into uniform contact with the auxiliary treatment liquid through the spray system configured in the equipment or by immersion. S4. Staining: Place the sample processed in step S3 into a staining machine for staining; S5. Setting and Drying: The sample dyed in step S4 is sent to a setting machine for setting. After setting, the product is obtained.

[0007] Further, in step S1, the island-shaped microfiber polyurethane synthetic leather is immersed in treatment solution 1 at a bath ratio of 1:5-50 and treated at 40-60°C for 10-30 min. The preparation process of treatment solution 1 in step S1 is as follows: First, add 50%-80% of the total volume of the treatment solution to be prepared into a mixing tank with room temperature deionized water. Start stirring and slowly add 1-3 g / L of isotridecyl alcohol polyoxyethylene ether at a stirring speed of 300-500 rpm. Then slowly add 5-15 g / L of benzyl alcohol. Subsequently, heat the system to 40-50°C and continue stirring at this temperature for 15-20 minutes to allow the benzyl alcohol to be fully emulsified under the action of isotridecyl alcohol polyoxyethylene ether. Then stop heating and add cold water to the mixing tank to the final volume, so that the liquid level reaches the predetermined mark to obtain the working solution. Adjust the pH of the working solution to 6-7 with acetic acid solution and continue stirring at room temperature for 5-10 minutes to ensure that the system is homogeneous. Treatment solution 1 can then be obtained.

[0008] Furthermore, in step S2, the sample treated in step S1 is immersed in treatment solution 2 at a bath ratio of 1:5-50 for padding treatment, with the roll-off rate controlled at 40%-80%; The preparation process of treatment solution 2 in step S2 is as follows: First, add 50%-80% of the total volume of the treatment solution 2 to the mixing tank with room temperature deionized water. Turn on the high-speed shear mixer and add the nano-cellulose whisker water dispersion slurry at a stirring speed of 500-1000 rpm. Continue high-speed shearing for 10-15 minutes until it is completely dispersed and there are no visible particles or flocs. Keep the stirring speed constant and slowly add the fiber protectant, crosslinking enhancer and penetrant in sequence. After each addition, continue stirring for 3-5 minutes to ensure that it is fully mixed before adding the next one. Reduce the stirring speed to 400-600 rpm, add the anti-pilling resin, softening component and lightfastness additive to the above materials in sequence, continue stirring to mix them evenly, then add cold water to the mixing tank to the final volume, make up the volume to obtain the working solution, and finally filter the prepared working solution with a standard sieve to remove any possible trace impurities or air bubbles to ensure a smooth impregnation process, and you will get treatment solution 2.

[0009] Furthermore, the concentration of the nanocellulose whiskers is 3-8 g / L; The fiber protectant is polyethylene glycol, wherein the concentration of polyethylene glycol is 5-10 g / L; The crosslinking reinforcing agent is a hyperbranched polyester, wherein the concentration of the hyperbranched polyester is 5-10 g / L; The penetrant is JFC, and its concentration is 5-10 g / L; The anti-pilling resin is a water-based polycarbodiimide crosslinking agent; wherein the concentration of the water-based polycarbodiimide crosslinking agent is 20-50 g / L; The softening component is a low-viscosity, high-elasticity amino-modified polyether silicone oil microemulsion, wherein the concentration of the low-viscosity, high-elasticity amino-modified polyether silicone oil microemulsion is 10-20 g / L and its viscosity is <1000 mPa·s. The light-resistant additive is a light stabilizer with a concentration of 1-3 g / L.

[0010] Furthermore, in step S3, the wet sample after step S2 is treated with a vibrating loose water washing machine or a swinging rubbing machine at a bath ratio of 1:5-50 for 5-15 minutes at a temperature of 40-60 °C. During the treatment, the sample is made to come into uniform contact with the auxiliary treatment liquid through the spray system configured in the equipment or by immersion. The preparation process of the auxiliary treatment solution in step S3 is as follows: First, add 50%-80% of the total volume of the auxiliary treatment solution to the mixing tank with room temperature deionized water. Turn on the stirrer and add the film-forming polymer at a stirring speed of 400-600 rpm. Stir until the polymer is completely dissolved and the solution is clear. Then, add the lubricating enhancer, crosslinking agent, and lightfastness agent in sequence. After adding each agent, continue stirring for 3-5 minutes to ensure uniform mixing. Finally, add water to the final volume, make up the volume, and continue stirring for 5-10 minutes to obtain the auxiliary treatment solution.

[0011] Furthermore, the film-forming polymer is polyvinylpyrrolidone, wherein the concentration of polyvinylpyrrolidone is 2-5 g / L; The lubricant enhancer is a water-soluble polyether-modified silicone oil, wherein the concentration of the water-soluble polyether-modified silicone oil is 1-2 g / L; The crosslinking agent is a temperature-sensitive, blocked waterborne polyurethane crosslinking agent, which has temperature-deblocking characteristics (greater than 100°C), remains stable during the shaking / kneading stage, and triggers the crosslinking reaction only in the final stabilization and shaping stage. Its concentration is 3-8 g / L. The light-resistant additive is a hindered amine light stabilizer and / or an ultraviolet absorber, wherein the concentration of the light stabilizer is 0.5-1.5 g / L.

[0012] Furthermore, the specific process of placing the sample processed in step S3 into the staining machine for staining in step S4 is as follows: After processing in step S3, the sample is immersed in a dye bath containing dye liquor at a liquor ratio of 1:20-40 for dyeing. The temperature is increased to 40-60℃ at a rate of 0.8-1.5℃ / min and run for 10-20 minutes to allow the lubricating and anti-pilling agent to be fully adsorbed onto the fiber surface and to pre-establish a protective layer. Then, the temperature is increased to 90-130℃ at a rate of 1-2℃ / min and held for 30-90 minutes to complete the dyeing process. After dyeing, the dye liquor is drained. Island-bonded nylon (PA) is washed with clean water, while island-bonded polyester (PET) is subjected to reduction cleaning to remove excess dye and surface additives. The preparation process of the dye solution is as follows: add water at a temperature of 40-50°C, which is 5%-10% of the final dye bath volume, into the container. Under stirring, slowly add the high-efficiency smoothing component and the antistatic component, initially dilute and stir evenly to form a pre-diluted solution, which is the composite high-temperature lubricating anti-pilling agent. Add water to the main cylinder of the dyeing machine to make up 70% of the final volume, and start the circulation pump to slowly add the prepared pre-diluted solution to the dye bath. Then add the dissolved dye and pH adjuster, and finally add water to the predetermined bath ratio. Circulate for 10-15 minutes to ensure that all auxiliaries and dyes are fully and evenly mixed in the dye bath.

[0013] Furthermore, the highly efficient smoothing component is a graphene-modified amino silicone microemulsion, wherein the concentration of the graphene-modified amino silicone microemulsion is 3-5 g / L; and the graphene content in the graphene-modified amino silicone oil microemulsion is 0.5%-2% owf. The antistatic component is fatty polyethylene glycol ester, wherein the concentration of fatty polyethylene glycol ester is 1-2 g / L; The pH adjuster is glacial acetic acid.

[0014] Furthermore, in step S5, the sample stained in step S4 is sent to a setting machine, pre-dried at 80-100°C for 2-5 minutes, and then set at 110-140°C for 5-8 minutes.

[0015] Furthermore, in step S4, the appropriate dyeing process is selected according to the composition of the island microfiber. Island microfiber polyurethane synthetic leather adopts disperse dye dyeing and high temperature and high pressure dyeing process, wherein the high temperature is 110-130℃ and the high pressure is 110-130℃. Nylon island microfiber polyurethane adopts acid dye and boiling dyeing process, wherein the temperature of the boiling dyeing process is 90-100℃.

[0016] The mechanism of this invention is as follows: 1) This invention first moderately swells the island-mounted microfiber polyurethane synthetic leather with a benzyl alcohol-containing swelling solution, opening up the fiber structure and creating favorable conditions for the penetration and bonding of subsequent functional additives. Then, through the synergistic effect of waterborne polycarbodiimide, hyperbranched polyester, and nanofiber whiskers, a strong and durable three-dimensional network structure is formed between the fibers, fundamentally inhibiting fiber separation. Next, a closed-type waterborne polyurethane crosslinking agent is selected as a consolidating agent. Its key innovation lies in the "sequential functional design (penetration first, reaction later; softening processing first, strong setting later)". This agent is chemically stable in the low-temperature vibration stage, only physically penetrating without affecting the feel. In the subsequent high-temperature setting stage, the active groups released after desealing crosslink with the network and fibers in the second step, acting like an elastic "bridge" to further consolidate the entire finishing system. Due to the elastic properties of its own film-forming material, it avoids the feel from becoming hard. 2) Waterborne polycarbodiimide serves as the main crosslinking agent, providing basic bonding strength; hyperbranched polyester (HBPE), with its three-dimensional spherical branched structure as flexible crosslinking points, synergistically forms a strong and elastic interpenetrating network structure with polycarbodiimide, rather than a traditional rigid crosslinked film, thus avoiding brittleness at the molecular design level; the addition of nanocellulose whiskers, due to their rich surface hydroxyl groups, can form a strong hydrogen bond network and partial covalent bonding with the polar groups of waterborne polyurethane and the islanded microfiber itself, significantly increasing the bonding energy and frictional resistance between fibers, and its excellent thermal stability makes it more difficult to remove fibers, thus fundamentally improving the anti-pilling performance; Simultaneously, low-viscosity, high-elasticity amino-modified polyether silicone oil microemulsion and polyethylene glycol are introduced during the crosslinking process, acting as internal lubricant and plasticizer respectively. This not only directly imparts and maintains the flexibility of the network, achieving a "strengthening while softening" effect, but also reduces adsorption residues in the dyeing vat and equipment, making cleaning easier and avoiding silicone spots. Furthermore, the penetrant promotes rapid penetration of the crosslinking agent into the fiber layer, enhancing the uniformity of crosslinking film formation. The lightfastness additive and modified organosilicon are both mature products with long-term market validation; therefore, they exhibit excellent chemical stability in aqueous systems, do not damage each other, and can even compensate for the yellowing defect caused by photo-oxidation after use of silicone-containing products, thereby improving lightfastness. 3) The graphene-modified amino-organic silicone microemulsion in this invention. The amino groups in its molecules greatly enhance its affinity with fibers, enabling it to quickly adsorb onto the fiber surface and form a durable, smooth protective film. This effectively reduces the dynamic / static friction coefficients between fibers and equipment, and between fibers themselves, fundamentally reducing the pulling effect of mechanical forces on the fibers. 4) Polyethylene glycol resin, by eliminating the static charge generated by intense friction during the dyeing process, prevents the fibers from standing upright and tangling due to electrostatic repulsion, thereby reducing the probability of pilling.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: 1) This invention utilizes the synergistic effect of water-based polycarbodiimide (rigid skeleton), hyperbranched polyester (flexible nodes), and nanocellulose whiskers (nano-reinforcing phase) to construct a unique "rigid-flexible" three-dimensional interpenetrating network structure between fibers. As shown in the test results of the examples, this structure can fundamentally inhibit fiber separation, enabling the product to achieve a pilling resistance of 4-5 levels and significantly improving abrasion resistance. At the same time, it avoids the stiff feel problem caused by traditional resin finishing, achieving a balance between high pilling resistance and excellent soft feel (5 out of 5 in the feel evaluation).

[0018] 2) This invention uses a temperature-sensitive, closed-type waterborne polyurethane crosslinking agent, whose function is triggered only in the final high-temperature process. This not only ensures its deep penetration and uniform distribution in the wet processing stage, avoiding a resinous feel on the surface, but also forms a solid crosslink in the final stage. This greatly improves the durability of the finishing effect (resistance to dry and wet friction, and washability) without sacrificing the feel, and solves the problem that traditional one-step crosslinking finishing is difficult to balance depth and feel.

[0019] 3) Addressing industry challenges such as silicone spots, color variations, and yellowing that are common with traditional silicone products, this invention offers precise solutions through additive selection and formulation design: a) Anti-fouling: The use of polyether-modified silicone oil and microemulsion-formulated amino silicone oil provides excellent emulsion stability, effectively resisting electrolytes, high temperatures, and shear stresses, fundamentally preventing equipment contamination (silicone spots) and fabric staining caused by demulsification; b) Compatibility: The selected silicone additives exhibit excellent chemical compatibility and compatibility with the resins, dyes, and other components in the system, preventing dye aggregation and unevenness caused by flocculation and precipitation during processing; c) Lightfastness: The combination of a composite lightfastness additive system and low-amino-value modified silicone oil effectively inhibits the photo-oxidative yellowing tendency of amino silicone oil, ensuring the product maintains excellent lightfastness (level 4) while achieving a soft feel. 4) This invention adds a composite high-temperature lubricating and anti-pilling agent (containing graphene-modified amino silicone oil) during the dyeing stage, and provides continuous lubrication and protection for the fiber throughout the dyeing process through precise temperature rise curve control. This effectively reduces the mechanical pull-out damage to the fiber during the dyeing process, achieving "dyeing while protecting", and improving production efficiency and first-pass success rate. 5) The process of this invention has strong synergy. The entire process, from "swelling pretreatment → resin crosslinking → vibration homogenization → dyeing protection → thermosetting", is precisely designed. Each step has a clear function and is closely linked. The synergistic effect between the additives is significant. It not only achieves the core goal of anti-pilling, but also comprehensively improves the product's physical properties such as tear strength, abrasion resistance, and color fastness, as well as its appearance quality. 6) The entire process of this invention avoids harmful substances such as formaldehyde. All the auxiliaries used are environmentally friendly and easy to obtain. The process conditions are mild and no special equipment is required. It is very suitable for large-scale industrial continuous production in existing printing and dyeing plants and has extremely high technical promotion value and market prospects. Detailed Implementation

[0020] The present invention will be further described below with reference to embodiments, but the scope of protection of the present invention is not limited to the scope described.

[0021] Example 1 (island-sea fiber obtained by composite spinning process, wherein the island component is nylon): S1: First, prepare treatment solution 1. The preparation process is as follows: First, add 60% of the total volume of the treatment solution 1 to the mixing tank with room temperature deionized water. Start stirring and slowly add 2 g / L of isotridecyl alcohol polyoxyethylene ether at a stirring speed of 400 rpm. Then slowly add 10 g / L of benzyl alcohol. Subsequently, heat the system to 45°C and continue stirring at this temperature for 15 minutes to allow the benzyl alcohol to be fully emulsified under the action of isotridecyl alcohol polyoxyethylene ether. Then stop heating and add cold water to the mixing tank to the final volume, so that the liquid level reaches the predetermined mark to obtain the working solution. Adjust the pH of the working solution to 7 with acetic acid solution or sodium bicarbonate solution, and continue stirring at room temperature for 8 minutes to ensure that the system is homogeneous. Treatment solution 1 can then be obtained.

[0022] The Dingdao microfiber polyurethane synthetic leather was immersed in treatment solution 1 at a bath ratio of 1:30 and treated at 50°C for 20 min. S2: The preparation process of treatment solution 2 is as follows: First, add 60% of the total volume of the treatment solution 2 to the mixing tank with room temperature deionized water. Turn on the high-speed shear mixer and add 5 g / L of nano-cellulose whisker water dispersion slurry at a stirring speed of 800 rpm. Continue high-speed shearing for 12 minutes until it is completely dispersed and there are no visible particles or flocculents. Keep the stirring speed constant and slowly add 8 g / L of polyethylene glycol, 8 g / L of crosslinking enhancer and 8 g / L of penetrant JFC in sequence. After each additive is added, continue stirring for 4 minutes to ensure that it is fully mixed before adding the next one. Reduce the stirring speed to 500 rpm, add 30 g / L of water-based polycarbodiimide crosslinking agent, 15 g / L of amino-modified polyether silicone oil emulsion and 2 g / L of light stabilizer to the above materials in sequence, continue stirring to mix evenly, then add cold water to the mixing tank to the final volume, make up the volume to obtain the working solution, and finally filter the prepared working solution with a standard sieve to remove any possible trace impurities or air bubbles to ensure a smooth impregnation process, thus obtaining treatment solution 2.

[0023] The sample processed in step S1 was immersed in treatment solution 2 at a bath ratio of 1:30 for padding treatment, with the roll-off rate controlled at 70%. S3: The preparation process of the auxiliary treatment solution is as follows: First, add 60% of the total volume of the auxiliary treatment solution to the mixing tank with room temperature deionized water. Turn on the stirrer and add 1.5 g / L of PVP at a stirring speed of 500 rpm. Stir until it is completely dissolved and the solution is clear. Then, add 1.5 g / L of water-soluble polyether modified silicone oil, 5 g / L of temperature-sensitive blocked waterborne polyurethane crosslinking agent, and 1 g / L of light stabilizer in sequence. After each additive is added, continue stirring for 4 minutes to ensure uniform mixing. Finally, add water to the final volume, make up the volume, and continue stirring for 8 minutes to obtain the auxiliary treatment solution.

[0024] The wet sample after step S2 was treated in a vibrating loose water washing machine at a bath ratio of 1:30 for 10 minutes at 50°C. During the treatment, the sample was made to come into uniform contact with the auxiliary treatment liquid through the spray system configured in the equipment or by immersion. S4: The preparation process of the dye solution is as follows: Add water at 45°C to the container, which is 8% of the final dye bath volume. Under stirring, slowly add 4 g / L of graphene-modified amino silicone emulsion and 1.5 g / L of fatty polyethylene glycol ester, pre-dilute and stir evenly to form a pre-diluted solution, which is the composite high-temperature lubricating anti-pilling agent. Add water to the main cylinder of the dyeing machine to make up 70% of the final volume, and start the circulation pump to slowly add the prepared pre-diluted solution to the dye bath. Then add the dissolved dye and pH adjuster, and finally add water to the predetermined bath ratio. Circulate for 12 minutes to ensure that all auxiliaries and dyes are fully and evenly mixed in the dye bath.

[0025] The sample treated in step S3 was immersed in a dye bath containing dye solution at a liquor ratio of 1:30 for dyeing. The temperature was increased to 50°C at a rate of 1°C / min and run for 15 minutes to allow the lubricating and anti-pilling agent to be fully adsorbed onto the fiber surface and to pre-establish a protective layer. Then the temperature was increased to 90°C at a rate of 1.5°C / min and held for 45 minutes to complete the dyeing. After dyeing, the dye solution was drained and the sample was then washed with clean water. S5: The sample dyed in step S4 is sent to the setting machine, pre-baked at 100°C for 3 minutes, and then set at 120°C for 6 minutes to deseal the blocked crosslinking agent and complete the final crosslinking to obtain the finished product.

[0026] Comparative Example 1: The base fabric was directly dyed using conventional dyeing (acid dye + ordinary leveling agent) and then fixed.

[0027] Comparative Example 2: Compared with Example 1, the S2 treatment solution 2 contained only 40 g / L of polycarbodiimide, and the rest was the same as in Example 1.

[0028] Comparative Example 3: Compared with Example 1, no hyperbranched polyester was added to the S2 treatment solution 2, and everything else was the same as in Example 1.

[0029] Comparative Example 4: Compared with Example 1, no nanocellulose whiskers were added to the S2 treatment solution 2, but everything else was the same as in Example 1.

[0030] Comparative Example 5: Compared with Example 1, no temperature-sensitive blocked waterborne PU crosslinking agent was added to the S3 treatment solution, and everything else was the same as in Example 1.

[0031] Comparative Example 6: Compared with Example 1, no auxiliaries were added to the S4 dye solution, and everything else was the same as in Example 1.

[0032] Comparative Example 7: Compared with Example 1, S2 uses ordinary amino silicone oil instead of amino-modified polyether silicone oil microemulsion, S3 uses ordinary hydroxyl silicone oil emulsion instead of water-soluble polyether modified silicone oil, and S4 uses ordinary amino organosilicon microemulsion instead of graphene-modified amino organosilicon microemulsion. The rest is the same as in Example 1.

[0033] Comparative Example 8: Compared with Example 1, no penetrant was added to the S2 treatment solution 2, and everything else was the same as in Example 1.

[0034] Comparative Example 9: Compared with Example 1, no light stabilizer / UV absorber was added to the S2 and S3 treatment solutions, and everything else was the same as in Example 1.

[0035]

[0036] Tear strength: According to GB / T 4689.22-2023 "Determination of Tear Strength in Physical and Mechanical Testing of Leather" Static friction coefficient: Refer to QB / T 5352-2018 "Test Methods for Surface Slipability of Artificial Leather and Synthetic Leather" Anti-pilling: According to GB / T 4802.2 "Textiles - Determination of Pilling Properties of Fabrics - Part 2: Modified Martindale Method" Colorfastness to sunlight: determined according to GB / T 8427-2008 "Textiles - Tests for colorfastness to artificial light: Xenon arc". Martindale abrasion test: according to GB / T 21196.2-2007 "Textiles - Martindale Method: Determination of Abrasion Resistance of Fabrics - Part 2: Determination of Specimen Breakage" Results Analysis

[0037] A comparison of Comparative Example 1 and Example 1 shows that the base fabric that was not treated by this method has serious pilling problems (level 1-2), which proves the necessity and basic effectiveness of this treatment method.

[0038] As can be seen from Comparative Example 2 and Example 1, relying solely on rigid cross-linked resin (polycarbodiimide) will sacrifice the feel, which leads to the necessity of compounding flexible components (HBPE) and lubricating components to construct a "rigid-flexible" network.

[0039] Comparative Examples 3 and 4, along with Example 1, demonstrate the core roles of hyperbranched polyester (HBPE) and nanocellulose whiskers in the synergistic construction of a high-strength, high-toughness, and high-heat-resistant interpenetrating network. The absence of HBPE leads to network insufficiency; the absence of nanocellulose whiskers results in insufficient network strength and reduced resistance to fraying.

[0040] Comparative Example 5 and Example 1 demonstrate the value of the "time-sequential functional design" of the temperature-sensitive blocked polyurethane crosslinking agent. It triggers crosslinking in the final stage, further strengthening the entire network and improving the durability of the finishing effect, thus providing a crucial guarantee for superior performance.

[0041] Comparative Example 6 and Example 1 demonstrate the importance of adding a specialized lubricating and anti-pilling agent during the dyeing process. This step continuously protects the fibers during the mechanical friction of dyeing, and is key to achieving "simultaneous protection in dyeing and finishing," preventing fiber damage and performance degradation.

[0042] As can be seen from Comparative Example 7 and Example 1, it is demonstrated that the use of organosilicon additives with specific structures (such as polyether-modified microemulsions and graphene-modified products) instead of traditional products is the key to successfully solving traditional industry problems such as "silicon spots, color variations, and yellowing", ensuring the stability of the process and the excellent appearance of the product.

[0043] Comparative Example 8 and Example 1 demonstrate the fundamental role of penetrants in ensuring uniform penetration of functional additives, preventing uneven surface treatment (stains), and maximizing overall effectiveness.

[0044] Comparative Example 9 and Example 1 demonstrate the importance of the lightfastness additive system in ensuring that the product does not yellow over long-term use and maintains its appearance quality, especially when amino-containing silicone oil is used.

Claims

1. A dyeing and finishing method for preventing fraying and pilling in island-type microfiber polyurethane synthetic leather, characterized in that... Includes the following steps: S1. Fiber swelling pretreatment: The island microfiber polyurethane synthetic leather is immersed in treatment solution 1 for treatment, and then thoroughly washed with water after treatment; S2. Anti-pilling resin treatment: The sample treated in step S1 is immersed in treatment solution 2 for padding; S3. Wet homogenization treatment: The wet sample after step S2 is processed by a vibrating loose water washing machine or a swinging rubbing machine. During the treatment, the sample is made to come into uniform contact with the auxiliary treatment liquid through the spray system configured in the equipment or by immersion. S4. Staining: Place the sample processed in step S3 into a staining machine for staining; S5. Setting and Drying: The sample dyed in step S4 is sent to a setting machine for setting. After setting, the product is obtained.

2. The anti-snagging and anti-pilling dyeing and finishing method for island-mounted microfiber polyurethane synthetic leather according to claim 1, characterized in that... In step S1, the island-shaped microfiber polyurethane synthetic leather is immersed in treatment solution 1 at a bath ratio of 1:5-50 and treated at 40-60°C for 10-30 min. The preparation process of treatment solution 1 in step S1 is as follows: First, add 50%-80% of the total volume of the treatment solution to be prepared into a mixing tank with room temperature deionized water. Start stirring and slowly add 1-3 g / L of isotridecyl alcohol polyoxyethylene ether at a stirring speed of 300-500 rpm. Then slowly add 5-15 g / L of benzyl alcohol. Subsequently, heat the system to 40-50°C and continue stirring at this temperature for 15-20 minutes to allow the benzyl alcohol to be fully emulsified under the action of isotridecyl alcohol polyoxyethylene ether. Then stop heating and add cold water to the mixing tank to the final volume, so that the liquid level reaches the predetermined mark to obtain the working solution. Adjust the pH of the working solution to 6-7 with acetic acid solution and continue stirring at room temperature for 5-10 minutes to ensure that the system is homogeneous. Treatment solution 1 can then be obtained.

3. The anti-snagging and anti-pilling dyeing and finishing method for island-mounted microfiber polyurethane synthetic leather according to claim 1, characterized in that... In step S2, the sample treated in step S1 is placed in treatment solution 2 at a bath ratio of 1:5-50 for padding treatment, and the roll-off rate is controlled at 40%-80%. The preparation process of treatment solution 2 in step S2 is as follows: First, add 50%-80% of the total volume of the treatment solution 2 to the mixing tank with room temperature deionized water. Turn on the high-speed shear mixer and add the nano-cellulose whisker water dispersion slurry at a stirring speed of 500-1000 rpm. Continue high-speed shearing for 10-15 minutes until it is completely dispersed and there are no visible particles or flocs. Keep the stirring speed constant and slowly add the fiber protectant, crosslinking enhancer and penetrant in sequence. After each addition, continue stirring for 3-5 minutes to ensure that it is fully mixed before adding the next one. Reduce the stirring speed to 400-600 rpm, add the anti-pilling resin, softening component and lightfastness additive to the above materials in sequence, continue stirring to mix them evenly, then add cold water to the mixing tank to the final volume, make up the volume to obtain the working solution, and finally filter the prepared working solution with a standard sieve to remove any possible trace impurities or air bubbles to ensure a smooth impregnation process, and you will get treatment solution 2.

4. The anti-snagging and anti-pilling dyeing and finishing method for island-mounted microfiber polyurethane synthetic leather according to claim 3, characterized in that... The concentration of the nanocellulose whiskers is 3-8 g / L; The fiber protectant is polyethylene glycol, wherein the concentration of polyethylene glycol is 5-10 g / L; The crosslinking reinforcing agent is a hyperbranched polyester, wherein the concentration of the hyperbranched polyester is 5-10 g / L; The penetrant is JFC, and its concentration is 5-10 g / L; The anti-pilling resin is a water-based polycarbodiimide crosslinking agent; wherein the concentration of the water-based polycarbodiimide crosslinking agent is 20-50 g / L; The softening component is a low-viscosity, high-elasticity amino-modified polyether silicone oil microemulsion, wherein the concentration of the low-viscosity, high-elasticity amino-modified polyether silicone oil microemulsion is 10-20 g / L and its viscosity is <1000 mPa·s. The light-resistant additive is a light stabilizer with a concentration of 1-3 g / L.

5. The anti-snagging and anti-pilling dyeing and finishing method for island-mounted microfiber polyurethane synthetic leather according to claim 1, characterized in that... In step S3, the wet sample after step S2 is treated with a oscillating loose water washing machine or a swinging rubbing machine at a bath ratio of 1:5-50 for 5-15 minutes at a temperature of 40-60 °C. During the treatment, the sample is made to come into uniform contact with the auxiliary treatment liquid through the spray system configured in the equipment or by immersion. The preparation process of the auxiliary treatment solution in step S3 is as follows: First, add 50%-80% of the total volume of the auxiliary treatment solution to the mixing tank with room temperature deionized water. Turn on the stirrer and add the film-forming polymer at a stirring speed of 400-600 rpm. Stir until the polymer is completely dissolved and the solution is clear. Then, add the lubricating enhancer, crosslinking agent, and lightfastness agent in sequence. After adding each agent, continue stirring for 3-5 minutes to ensure uniform mixing. Finally, add water to the final volume, make up the volume, and continue stirring for 5-10 minutes to obtain the auxiliary treatment solution.

6. The anti-snagging and anti-pilling dyeing and finishing method for island-mounted microfiber polyurethane synthetic leather according to claim 5, characterized in that... The film-forming polymer in step S3 is polyvinylpyrrolidone, wherein the concentration of polyvinylpyrrolidone is 2-5 g / L; The lubricant is a water-soluble polyether-modified silicone oil, wherein the concentration of the water-soluble polyether-modified silicone oil is 1-2 g / L. The crosslinking agent used to strengthen the crosslinking is a temperature-sensitive, blocked waterborne polyurethane crosslinking agent with a concentration of 3-8 g / L. The lightfastness agent is a hindered amine light stabilizer and / or an ultraviolet absorber, wherein the concentration of the light stabilizer is 0.5-1.5 g / L. The lightfastness agents used in this invention include, but are not limited to, benzotriazole ultraviolet absorbers or hindered amine light stabilizers. Its function is to effectively absorb or eliminate ultraviolet energy and inhibit photo-oxidative degradation.

7. The anti-snagging and anti-pilling dyeing and finishing method for island-mounted microfiber polyurethane synthetic leather according to claim 1, characterized in that... The specific process of placing the sample processed in step S3 into the staining machine for staining in step S4 is as follows: After the S3 step, the sample is immersed in a dye bath containing dye liquor at a liquor ratio of 1:20-40 for dyeing. The temperature is increased to 40-60℃ at a rate of 0.8-1.5℃ / min and run for 10-20 minutes to allow the lubricating and anti-pilling agent to be fully adsorbed onto the fiber surface and a protective layer is pre-established. Then, the temperature is increased to 90-130℃ at a rate of 1-2℃ / min and held for 30-90 minutes to complete the dyeing. After dyeing, the dye liquor is drained. Island-bonded nylon is washed with clean water, while island-bonded polyester is subjected to reduction cleaning to remove floating dye and surface auxiliaries. The preparation process of the dye solution is as follows: add water at a temperature of 40-50°C, which is 5%-10% of the final dye bath volume, into the container. Under stirring, slowly add the high-efficiency smoothing component and the antistatic component, initially dilute and stir evenly to form a pre-diluted solution, which is the composite high-temperature lubricating anti-pilling agent. Add water to the main cylinder of the dyeing machine to make up 70% of the final volume, and start the circulation pump to slowly add the prepared pre-diluted solution to the dye bath. Then add the dissolved dye and pH adjuster, and finally add water to the predetermined bath ratio. Circulate for 10-15 minutes to ensure that all auxiliaries and dyes are fully and evenly mixed in the dye bath.

8. The anti-snagging and anti-pilling dyeing and finishing method for island-mounted microfiber polyurethane synthetic leather according to claim 7, characterized in that... The high-efficiency smoothing component mentioned in step S4 is a graphene-modified amino silicone microemulsion, wherein the concentration of the graphene-modified amino silicone microemulsion is 3-5 g / L; the graphene content in the graphene-modified amino silicone oil microemulsion is 0.5%-2% owf. The antistatic component is fatty polyethylene glycol ester, wherein the concentration of fatty polyethylene glycol ester is 1-2 g / L; The pH adjuster is glacial acetic acid.

9. The anti-snagging and anti-pilling dyeing and finishing method for island-mounted microfiber polyurethane synthetic leather according to claim 1, characterized in that... In step S5, the sample stained in step S4 is sent to the setting machine and pre-baked at 80-100°C for 2-5 minutes, and then set at 110-140°C for 5-8 minutes.

10. The anti-snagging and anti-pilling dyeing and finishing method for island-mounted microfiber polyurethane synthetic leather according to claim 7, characterized in that... In step S4, the appropriate dyeing process is selected according to the composition of the island microfiber. Island microfiber polyurethane synthetic leather adopts disperse dye dyeing and high temperature dyeing process, with the temperature being 110-130℃; nylon island microfiber polyurethane adopts acid dye and boiling dyeing process, with the boiling dyeing process temperature being 90-100℃.

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