Durable antibacterial finishing liquid and antibacterial wool fabric

Abstract

This application discloses a durable antibacterial finishing liquid and an antibacterial wool fabric. The finishing liquid comprises the following raw materials in parts by weight: 10-20 parts of waterborne polyurethane, 1-5 parts of antibacterial agent, 0.5-2 parts of penetrant, 1-3 parts of dispersant, and 50-120 parts of deionized water. The waterborne polyurethane comprises polyurethane A and polyurethane B in a mass ratio of 1:0.4-0.8. Polyurethane A is prepared by a Michael addition reaction of polyurethane containing acrylate end groups with amino silicone oil; polyurethane B is prepared by a Michael addition reaction of polyurethane containing acrylate end groups with amino polyether. The solution of this application can solve the problems of poor water resistance and easy peeling of existing antibacterial finishing coatings for wool fabrics, resulting in insufficient antibacterial durability.

Description

Technical Field

[0001] This application relates to the field of fabric finishing, and in particular to a durable antibacterial finishing liquid and its antibacterial wool fabric. Background Technology

[0002] Wool fabrics hold an important place in the realm of intimate apparel and high-end clothing due to their excellent moisture absorption, soft feel, and superior warmth. However, the main component of wool fibers is keratin, which readily absorbs sebum and sweat secreted by the body during wear, providing favorable nutrients and an environment for the growth of bacteria, fungi, and other microorganisms. The proliferation of microorganisms can not only cause unpleasant odors in the fabric but may also lead to fiber damage, discoloration, and even skin irritation or infection, severely reducing the wearing experience and hygiene.

[0003] Currently, antibacterial finishing of wool fabrics typically employs impregnation or padding processes, co-treating inorganic or organic antibacterial agents with film-forming adhesives such as polyurethane, acrylate copolymers, and epoxy resins. The antibacterial agents are anchored to the fiber surface through film formation. However, the polymer film formed by this method has poor water resistance. During washing, the film swells upon contact with water, generating internal stress. Combined with the mechanical rubbing and repeated fiber deformation during washing, the coating is prone to micro-cracks, blistering, and even peeling off in large sheets. Once the film is damaged, the antibacterial agent encapsulated within is exposed and rapidly released, leading to a significant reduction in antibacterial effectiveness. Consequently, most existing antibacterial wool fabrics may experience an antibacterial rate dropping to below 60% of their initial value after no more than ten standard household washes, far from meeting the requirements for repeated washing in actual wear. Summary of the Invention

[0004] This application aims to address the problem that existing antibacterial finishing coatings for wool fabrics have poor water resistance and are easily peeled off, resulting in insufficient antibacterial durability.

[0005] In a first aspect, this application provides a durable antibacterial finishing solution, comprising the following raw materials in parts by weight: The mixture comprises 10-20 parts of waterborne polyurethane, 1-5 parts of antibacterial agent, 0.5-2 parts of penetrant, 1-3 parts of dispersant, and 50-120 parts of deionized water; the waterborne polyurethane includes polyurethane A and polyurethane B in a mass ratio of 1:0.4-0.8, wherein polyurethane A is prepared by Michael addition reaction of polyurethane containing acrylate end groups with amino silicone oil; and polyurethane B is prepared by Michael addition reaction of polyurethane containing acrylate end groups with amino polyether.

[0006] In some embodiments, the preparation method of the acrylate-containing polyurethane is as follows: Polyether polyol, diisocyanate and chain extender are reacted to obtain polyurethane prepolymer with isocyanate end groups; A polyurethane prepolymer is subjected to a capping reaction with hydroxy acrylate to obtain a polyurethane containing acrylate end groups.

[0007] In some embodiments, the molar ratio of the polyether polyol, chain extender, hydroxy acrylate and diisocyanate in the raw materials of the acrylate-containing polyurethane is 1:0.8-1.5:0.2-1.0:2.2-2.8.

[0008] In some embodiments, the polyether polyol is selected from at least one of polyethylene glycol, polypropylene glycol, and polytetrahydrofuran ether glycol.

[0009] In some embodiments, the number-average molecular weight of the polyether polyol is 600 to 4000.

[0010] In some embodiments, the diisocyanate is selected from at least one of hexamethylene diisocyanate, pentamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, naphthalene-1,5-diisocyanate, phenyl dimethyl diisocyanate, 4,4-dicyclohexylmethane diisocyanate, norbornene diisocyanate, and isophorone diisocyanate; preferably isophorone diisocyanate or 4,4-dicyclohexylmethane diisocyanate.

[0011] In some embodiments, the chain extender is selected from at least one of ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, dimethylolpropionic acid, dimethylolbutyric acid, 1,5-pentanediol, 3-methyl-1,5-pentanediol, neopentanediol, 1,6-hexanediol, and diethylene glycol.

[0012] In some embodiments, the reaction temperature in the polyurethane prepolymer preparation step is 50–100°C.

[0013] In some embodiments, the Michael addition reaction is carried out at a temperature of 50–70°C for 3–8 hours.

[0014] In some embodiments, the hydroxyacrylate is selected from at least one of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, and hydroxybutyl methacrylate.

[0015] The key to improving antibacterial durability in this application lies in the separate preparation and compounding of two end-group-grafted modified waterborne polyurethanes, rather than the conventional side-link grafting modification. First, isocyanate end groups are capped with hydroxyacrylate to obtain a polyurethane precursor containing acrylate end groups. Subsequently, this precursor is subjected to Michael addition reactions with amino silicone oil and amino polyether, respectively, to obtain polyurethane A with end-group-grafted organosilicon segments and polyurethane B with end-group-grafted polyether segments. When the finishing solution cures into a film on the surface of wool fibers, the organosilicon segments at the ends of the polyurethane A molecular chains, due to their high degree of freedom and extremely low surface energy, rapidly migrate to the membrane-air interface and densely align, self-assembling to form a siloxane hydrophobic layer. This surface layer effectively prevents liquid water from penetrating and diffusing into the membrane, significantly reducing internal stress caused by water absorption and swelling, thereby inhibiting the formation of microcracks. Simultaneously, it significantly reduces the rate at which the antibacterial agent embedded in the membrane migrates and dissolves outward, thus improving the coating's wash resistance and long-lasting antibacterial effect.

[0016] However, while using only polyurethane A can enhance water repellency, it drastically reduces the wetting and spreading ability of the finishing solution on the wool cuticle layer, resulting in insufficient interfacial adhesion between the coating and the wool substrate, thus reducing overall durability. Therefore, this application uses polyurethane B with end-group grafted hydrophilic polyether segments. The polyether segments on polyurethane B, utilizing their hydrophilicity and surface activity, balance the overall surface tension of the system, ensuring sufficient wetting, spreading, and penetration of the finishing solution onto the wool fiber surface, allowing the coating to form a tight contact with the fiber. Furthermore, the unreacted amino groups introduced by the polyether amine in polyurethane B can form hydrogen bonds and even ionic bonds with the carboxyl and hydroxyl groups on the side chains of wool keratin macromolecules, producing a chemical anchoring effect, enhancing the interfacial adhesion strength of the coating on the fiber, and effectively preventing the coating from peeling off completely under mechanical abrasion. By blending polyurethane A and polyurethane B in a certain proportion, through synergistic action, the coating simultaneously possesses surface hydrophobic shielding properties and high adhesion.

[0017] It is worth noting that grafting functional segments onto the end groups of polyurethanes, rather than onto the main chain side groups, demonstrates advantages in both modified polyurethanes. For polyurethane A, the end-group-grafted silicone segments exhibit greater mobility, are more easily enriched on the surface, and have higher hydrophobic construction efficiency. Simultaneously, the long end-group chains increase the free volume between molecular chains, generating an internal plasticizing effect, imparting higher elongation at break and flexibility to the coating, making it less prone to cracking when subjected to washing, rubbing, and repeated fiber deformation. The end-group polyether segments of polyurethane B also possess an internal plasticizing effect, and its terminal amino groups ensure effective bonding with the wool interface. The synergistic end-group structures of the two polyurethanes further guarantee the integrity of the film layer and the soft hand feel of the finished fabric.

[0018] In some embodiments, the amino silicone oil has ≤2 amino functional groups, preferably a terminal amino silicone oil with 2 amino functional groups.

[0019] In some embodiments, the viscosity of the amino silicone oil is 10–100 mm. 2 / s; preferably 10–50 mm 2 / s.

[0020] In some embodiments, the number-average molecular weight of the amino polyether is 600–2000 g / mol.

[0021] Preferably, the number of amino functional groups in the amino polyether is ≤2.

[0022] When the viscosity of amino silicone oil is less than 10 mm 2 At a viscosity of 100 μm / s, the corresponding molecular chains are too short, resulting in insufficient length of the organosilicon segments formed after grafting to the polyurethane ends. These segments cannot fully extend and cover the film surface during film formation, making it difficult to form a continuous and complete low surface energy hydrophobic layer. Consequently, the water-repellent effect is significantly reduced, and the improvement in wash resistance is extremely limited. Conversely, if the viscosity exceeds 100 μm / s... 2 If the molecular weight of amino silicone oil is too large, the viscosity of the reaction system increases sharply, the reaction efficiency decreases, and excessive unreacted high-viscosity silicone oil will severely disrupt the dispersion balance of the emulsion, leading to demulsification, layering, or precipitation in the finishing solution. Similarly, the molecular weight of amino polyether also needs to be appropriate. When the number average molecular weight is below 600 g / mol, the polyether segments are too short, resulting in insufficient ability to improve wettability, leaving interfacial defects between the coating and the fiber, and weak adhesion strength. When the molecular weight is above 2000 g / mol, the grafting rate decreases significantly, and the synergistic effect is difficult to achieve. Therefore, the above parameter limits can ensure efficient reaction, and by compounding polyurethane A and B, the two introduced segments have suitable chain lengths, achieving a balance between hydrophobic shielding and wetting adhesion, thereby giving the coating durable protective performance.

[0023] In some embodiments, the molar ratio of acrylate groups in the polyurethane containing acrylate end groups to amino groups in the amino silicone oil is 1:2.0 to 2.2.

[0024] In some embodiments, the molar ratio of acrylate groups to amino groups in the acrylate-terminated polyurethane to amino groups in the amino polyether is 1:1.0 to 2.2.

[0025] In some embodiments, the antibacterial agent is selected from at least one of nano silver, nano zinc oxide, quaternary ammonium salt antibacterial agents, guanidine antibacterial agents, chitosan and its derivatives; And / or, the penetrant is selected from at least one of fatty alcohol polyoxyethylene ether, alkyl sulfonate, alkylbenzene sulfonate, and JFC penetrant; And / or, the dispersant is selected from at least one of polycarboxylate, polyacrylate, and naphthalene sulfonate formaldehyde condensate.

[0026] In a second aspect, this application provides an antibacterial wool fabric, which is prepared by padding with any of the durable antibacterial finishing liquids described in the first aspect, wherein the bath ratio is 1:8 to 12, the pick-up rate is 70 to 80%, the finishing temperature is 40 to 80°C, and the finishing time is 20 to 60 minutes.

[0027] In summary, this application has the following beneficial effects: This application utilizes a composite of polyurethane A (terminated with organosilicon segments) and polyurethane B (terminated with polyether segments) as a film-forming binder to achieve long-term anchoring of antibacterial agents on wool fibers. During the padding and baking process of the finishing solution, the organosilicon segments of polyurethane A spontaneously migrate to the coating surface, forming a low-surface-energy hydrophobic barrier that effectively prevents water molecules from penetrating and diffusing into the film, inhibiting microcracks caused by swelling and the dissolution of antibacterial agents. Simultaneously, the polyether segments of polyurethane B improve the wettability of the finishing solution to the wool scales and can form hydrogen bonds or ionic bonds with the wool fibers through the retention of active amino groups, significantly enhancing the coating adhesion. The internal plasticizing effect of the end-group organosilicon endows the coating with excellent flexibility and resistance to mechanical damage, making it less prone to cracking and peeling under repeated rubbing and fiber deformation. The wool fabric treated with this application maintains highly efficient and stable antibacterial properties even after multiple washes, achieving a durable antibacterial effect. Detailed Implementation

[0028] Preparation Example Preparation Example 1-1, Polyurethane A, the preparation steps are as follows: In a dry reactor equipped with a stirrer, thermometer, and reflux condenser, 2000 g of polyethylene glycol (PEG-2000, 1 mol) was added, and the mixture was heated to 110 °C and vacuum dehydrated for 2 h. The temperature was then lowered to 90 °C, and 117.4 g of dimethylolpropionic acid (0.875 mol) was added, followed by stirring for 30 minutes to ensure complete dissolution. The temperature was then lowered to 80 °C, and 556 g of isophorone diisocyanate (2.5 mol) and approximately 300 g of acetone were added, along with 1.4 g of dibutyltin dilaurate catalyst. The mixture was stirred at 80 °C for 2 h. The temperature was then lowered to 60 °C, and a mixture of 33.8 g of 1,4-butanediol (0.375 mol) and 700 g of acetone was added dropwise. The mixture was stirred at 60 °C for 2 h to extend the chain, yielding a polyurethane prepolymer solution with isocyanate end groups. Then add 58.1g of hydroxyethyl acrylate (0.5mol) and 0.035g of hydroquinone, and continue the reaction at 60℃ for 4h to obtain a polyurethane solution containing acrylate end groups.

[0029] The above solution was cooled to 50°C, and 1190.5 g (1.0 mol) of amino-terminated silicone oil WACKER was added. ®Fluid NH30D (kinematic viscosity approximately 40 mm² / s, 25°C; amine content approximately 0.84 meq / g) was reacted with stirring at 55°C for 5 hours. The mixture was then cooled to 40°C, and 88.5 g of triethylamine was added, followed by stirring and neutralization for 30 minutes. Subsequently, deionized water was slowly added under high-speed stirring to perform reverse emulsification. Finally, acetone was removed under reduced pressure to obtain polyurethane A with a solid content of approximately 35%.

[0030] Preparation Examples 1-2, Polyurethane A, the preparation steps are as follows: In a dry reactor equipped with a stirrer, thermometer, and reflux condenser, 1000 g of polypropylene glycol (PPG-1000, number average molecular weight 1000 g / mol, 1 mol) was added, and the mixture was heated to 110 °C for vacuum dehydration for 2 hours. The temperature was then lowered to 90 °C, and 84.5 g of dimethylolpropionic acid (0.63 mol) was added, followed by stirring for 30 minutes until completely dissolved. The temperature was then lowered to 75 °C, and 488.7 g of isophorone diisocyanate (2.2 mol) and approximately 200 g of acetone were added, along with 0.6 g of dibutyltin dilaurate catalyst. The mixture was stirred at 75 °C for 2 hours. The temperature was then lowered to 55 °C, and a mixture of 28.1 g of neopentyl glycol (0.27 mol) and 400 g of acetone was added dropwise. The mixture was stirred at 55 °C for 2 hours to extend the chain, yielding a polyurethane prepolymer solution with isocyanate end groups. Then add 69.7g of hydroxyethyl acrylate (0.6mol) and 0.056g of polymerization inhibitor p-hydroxyanisole, and continue the reaction at 55℃ for 4h to obtain a polyurethane solution containing acrylate end groups.

[0031] Cool the above solution to 45°C and add 667g of amino silicone oil WACKER. ® Fluid NH 15D (kinematic viscosity approximately 14 mm² / s, 25°C; amine content approximately 1.8 meq / g) was reacted at 50°C with stirring for 6 hours. The mixture was then cooled to 40°C, and 63.8 g of triethylamine (0.63 mol) was added, followed by stirring and neutralization for 30 min. Subsequently, deionized water was slowly added under high-speed stirring to perform reverse emulsification. Finally, acetone was removed under reduced pressure to obtain polyurethane A with a solid content of approximately 30%.

[0032] Preparation Examples 1-3, Polyurethane A, the preparation steps are as follows: In a dry reactor equipped with a stirrer, thermometer, and reflux condenser, 3000 g of polyethylene glycol (PEG-3000, number average molecular weight 3000 g / mol, 1 mol) was added, and the mixture was heated to 120 °C for vacuum dehydration for 2 hours. The temperature was then lowered to 90 °C, and 131.5 g of dimethylolpropionic acid (0.98 mol) was added, followed by stirring for 30 minutes until completely dissolved. The temperature was then lowered to 85 °C, and 734.8 g of 4,4'-dicyclohexylmethane diisocyanate (2.8 mol) and approximately 400 g of acetone were added, along with 3.0 g of dibutyltin dilaurate catalyst. The mixture was stirred at 85 °C for 2 hours. The temperature was then lowered to 65 °C, and a mixture of 37.9 g of 1,4-butanediol (0.42 mol) and 800 g of acetone was added dropwise. The mixture was stirred at 65 °C for 2 hours to extend the chain, yielding a polyurethane prepolymer solution with isocyanate end groups. Then add 115.3g of hydroxybutyl acrylate (0.8mol) and 0.066g of hydroquinone as a polymerization inhibitor, and continue the reaction at 65℃ for 6h to obtain a polyurethane solution containing acrylate end groups.

[0033] Cool the above solution to 55°C and add 2095g of amino-terminated silicone oil WACKER. ® Fluid NH 30D (kinematic viscosity approximately 40 mm² / s, 25°C; amine content approximately 0.84 meq / g) was reacted at 60°C with stirring for 4.5 hours. The mixture was then cooled to 40°C, and 99.2 g of triethylamine (0.98 mol) was added, followed by stirring and neutralization for 30 minutes. Subsequently, deionized water was slowly added under high-speed stirring to perform reverse emulsification. Finally, acetone was removed under reduced pressure to obtain polyurethane A with a solid content of approximately 38%.

[0034] Preparation Examples 1-4, Polyurethane A, differ from Preparation Example 1-1 in that an equimolar mass (123 g) of amino silicone oil WACKER was used. ® FLUID NH 02D (kinematic viscosity approximately 4.2 mm) 2 / s, 25℃; amine content approximately 8.1 meq / g) (replace WACKER) ® FLUID NH 30D (kinematic viscosity approximately 40 mm) 2 / s, 25℃; amine content is approximately 0.84 meq / g).

[0035] Preparation Examples 1-5, Polyurethane A, differ from Preparation Example 1-1 in that an equimolar mass (4347 g) of amino silicone oil WACKER was used. ® FLUID NH 130D (kinematic viscosity approx. 500 mg / L) 2 / s, 25℃; amine content approximately 0.23 meq / g) (replace WACKER) ® FLUID NH 30D (kinematic viscosity approximately 40 mm)2 / s, 25℃; amine content is approximately 0.84 meq / g).

[0036] Preparation Example 2-1, Polyurethane B, was prepared according to the following steps: In a dry reactor equipped with a stirrer, thermometer, and reflux condenser, 2000 g of polyethylene glycol (PEG-2000, number average molecular weight 2000 g / mol, 1 mol) was added, and the mixture was heated to 110 °C for vacuum dehydration for 2 hours. The temperature was then lowered to 90 °C, and 117.4 g of dimethylolpropionic acid (0.875 mol) was added, followed by stirring for 30 minutes until completely dissolved. The temperature was then lowered to 80 °C, and 556 g of isophorone diisocyanate (2.5 mol) and approximately 300 g of acetone were added, along with 1.4 g of dibutyltin dilaurate catalyst. The mixture was stirred at 80 °C for 2 hours. The temperature was then lowered to 60 °C, and a mixture of 33.8 g of 1,4-butanediol (0.375 mol) and 700 g of acetone was added dropwise. The mixture was stirred at 60 °C for 2 hours to extend the chain, yielding a polyurethane prepolymer solution with isocyanate end groups. Then add 58.1g of hydroxyethyl acrylate (0.5mol) and 0.035g of polymerization inhibitor hydroquinone, and continue the reaction at 60℃ for 4h to obtain a polyurethane solution containing acrylate end groups.

[0037] The above solution was cooled to 50°C, and 700g of amino-terminated polyether (Yangzhou Chenhua New Materials CAED-1200, average molecular weight approximately 1200g / mol, amine value approximately 1.5mmol / g) was added. The mixture was stirred at 55°C for 5 hours. The temperature was then lowered to 40°C, and 88.5g of triethylamine was added. The mixture was stirred and neutralized for 30 minutes. Subsequently, deionized water was slowly added under high-speed stirring to perform reverse emulsification. Acetone was removed under reduced pressure to obtain polyurethane B with a solid content of approximately 35%.

[0038] Preparation Example 2-2, Polyurethane B, was prepared according to the following steps: In a dry reactor equipped with a stirrer, thermometer, and reflux condenser, 1000 g of polypropylene glycol (PPG-1000, number average molecular weight 1000 g / mol, 1 mol) was added, and the mixture was heated to 110 °C for vacuum dehydration for 2 hours. The temperature was then lowered to 90 °C, and 84.5 g of dimethylolpropionic acid (0.63 mol) was added, followed by stirring for 30 minutes until completely dissolved. The temperature was then lowered to 75 °C, and 488.7 g of isophorone diisocyanate (2.2 mol) and approximately 200 g of acetone were added, along with 0.6 g of dibutyltin dilaurate catalyst. The mixture was stirred at 75 °C for 2 hours. The temperature was then lowered to 55 °C, and a mixture of 24.3 g of 1,4-butanediol (0.27 mol) and 400 g of acetone was added dropwise. The mixture was stirred at 55 °C for 2 hours to extend the chain, yielding a polyurethane prepolymer solution with isocyanate end groups. Then add 69.7g of hydroxyethyl acrylate (0.6mol) and 0.056g of polymerization inhibitor p-hydroxyanisole, and continue the reaction at 55℃ for 4h to obtain a polyurethane solution containing acrylate end groups.

[0039] The above solution was cooled to 45°C, and 571.4 g of amino-terminated polyether (Hunsmann Jeffamine M-2005, average molecular weight approximately 2000 g / mol, amine value approximately 1.05 mmol / g) was added. The mixture was stirred at 50°C for 6 hours. The temperature was then lowered to 40°C, and 63.8 g of triethylamine (0.63 mol) was added. The mixture was stirred and neutralized for 30 minutes. Subsequently, deionized water was slowly added under high-speed stirring to perform reverse emulsification. Acetone was removed under reduced pressure to obtain polyurethane B with a solid content of approximately 38%.

[0040] Preparation Example 2-3, Polyurethane B, was prepared according to the following steps: In a dry reactor equipped with a stirrer, thermometer, and reflux condenser, 3000 g of polytetrahydrofuran ether glycol (PTMEG-3000, number average molecular weight 3000 g / mol, 1 mol) was added, and the mixture was heated to 120 °C for vacuum dehydration for 2 hours. The temperature was then lowered to 90 °C, and 131.5 g of dimethylolpropionic acid (0.98 mol) was added, followed by stirring for 30 minutes until completely dissolved. The temperature was then lowered to 85 °C, and 734.8 g of 4,4'-dicyclohexylmethane diisocyanate (2.8 mol) and approximately 400 g of acetone were added, along with 3.0 g of dibutyltin dilaurate catalyst. The mixture was stirred at 85 °C for 2 hours. The temperature was then lowered to 65 °C, and a mixture of 37.9 g of 1,4-butanediol (0.42 mol) and 800 g of acetone was added dropwise. The mixture was stirred at 65 °C for 2 hours to extend the chain, yielding a polyurethane prepolymer solution with isocyanate end groups. Then add 115.3g of hydroxybutyl acrylate (0.8mol) and 0.066g of hydroquinone as a polymerization inhibitor, and continue the reaction at 65℃ for 6h to obtain a polyurethane solution containing acrylate end groups.

[0041] The above solution was cooled to 55°C, and 550g of amino-terminated polyether (Yangzhou Chenhua New Materials CAED-600, average molecular weight approximately 600g / mol, amine value approximately 3.2mmol / g) was added. The mixture was stirred at 60°C for 4.5 hours. The temperature was then lowered to 40°C, and 99.2g of triethylamine (0.98mol) was added. The mixture was stirred and neutralized for 30 minutes. Subsequently, deionized water was slowly added under high-speed stirring to perform reverse emulsification. Finally, acetone was removed under reduced pressure to obtain polyurethane B with a solid content of approximately 35%.

[0042] Preparation Example 2-4, Polyurethane B, differs from Preparation Example 2-1 in that 700g of amino-terminated polyether (Yangzhou Chenhua New Materials CAED-1200, average molecular weight about 1200g / mol, amine value about 4.4mmol / g) is replaced with an equimolar mass (238.6g) of amino-terminated polyether (Yangzhou Chenhua New Materials CAD-400, average molecular weight about 400g / mol, amine value about 4.4mmol / g).

[0043] Preparation Example 2-5, Polyurethane B, differs from Preparation Example 2-1 in that 700g of terminal amino polyether (Yangzhou Chenhua New Materials CAED-1200, average molecular weight about 1200g / mol, amine value about 1.0mmol / g) is replaced with an equimolar mass (1050g) of terminal amino polyether (Huntersmann Jeffamine D-4000, average molecular weight about 4000g / mol, amine value about 1.0mmol / g).

[0044] Example 1: An antibacterial wool fabric, obtained by the following steps: Take 100g of polyurethane A prepared in Preparation Example 1-1 and 60g of polyurethane B prepared in Preparation Example 2-1, mix them, and then add 20g of nano-silver antibacterial agent (Zhejiang Zhitai Nano-Micro New Materials ZT-AG01, average particle size 15±5nm), 10g of penetrant JFC-1 (fatty alcohol polyoxyethylene ether), and 20g of dispersant TEGO. ® Disperse 750 W and 800g of deionized water at a bath ratio of 1:10, and disperse at 800rpm for 30 minutes at room temperature to obtain a uniform durable antibacterial finishing solution for wool fabrics.

[0045] Finishing of antibacterial wool fabric: Take a wool fabric (100% Merino wool, fineness 19.5μm, weight 200g / m²), and treat it with the above finishing solution through a padding machine using a two-dip, two-nip process, with the pick-up rate controlled at 70%, the finishing temperature at 60℃, and the finishing time at 40 minutes. After finishing, remove the wool fabric and bake it in a 130℃ oven for 3 minutes, then let it cool naturally to room temperature to obtain the antibacterial wool fabric.

[0046] Example 2: An antibacterial wool fabric, obtained by the following steps: Take 80g of polyurethane A prepared in Preparation Example 1-2 and 35g of polyurethane B prepared in Preparation Example 2-2, mix them, and then add 12g of dimethyloctadecyl(3-(trimethoxysilyl)propyl)ammonium chloride, 6g of penetrant JFC-1 (fatty alcohol polyoxyethylene ether), and 10g of dispersant TEGO. ® Disperse 750 W and 550g of deionized water at a bath ratio of 1:8, and disperse at 800rpm for 30 minutes at room temperature to obtain a uniform durable antibacterial finishing solution for wool fabrics.

[0047] Finishing of antibacterial wool fabric: Take a wool fabric (100% Merino wool, fineness 19.5μm, weight 200g / m²), and treat it with the above finishing solution through a padding machine using a two-dip, two-nip process, with the pick-up rate controlled at 75%, the finishing temperature at 45℃, and the finishing time at 60 minutes. After finishing, remove the wool fabric and bake it in a 130℃ oven for 2 minutes, then let it cool naturally to room temperature to obtain the antibacterial wool fabric.

[0048] Example 3: An antibacterial wool fabric, obtained by the following steps: Take 110g of polyurethane A prepared in Preparation Example 1-1 and 80g of polyurethane B prepared in Preparation Example 2-1, mix them, and then add 20g of nano-silver antibacterial agent (Zhejiang Zhitai Nano Micro New Materials ZT-AG01, average particle size 15±5nm), 20g of dimethyloctadecyl(3-(trimethoxysilyl)propyl)ammonium chloride, 15g of penetrant JFC-1 (fatty alcohol polyoxyethylene ether), and 30g of dispersant TEGO. ® Disperse 750 W and 1200g of deionized water at a bath ratio of 1:12, and disperse at 1000rpm for 20 minutes at room temperature to obtain a uniform durable antibacterial finishing solution for wool fabrics.

[0049] Finishing of antibacterial wool fabric: Take a wool fabric (100% Merino wool, fineness 19.5μm, weight 200g / m²), and treat it with the above finishing solution through a padding machine using a two-dip, two-nip process, with the pick-up rate controlled at 70%, the finishing temperature at 70℃, and the finishing time at 25 minutes. After finishing, remove the wool fabric and bake it in a 130℃ oven for 3 minutes, then let it cool naturally to room temperature to obtain the antibacterial wool fabric.

[0050] Example 4, an antibacterial wool fabric, differs from Example 1 in that an equal amount of polyurethane A prepared in Examples 1-4 is used to replace the polyurethane A prepared in Example 1-1.

[0051] Example 5, an antibacterial wool fabric, differs from Example 1 in that an equal amount of polyurethane A prepared in Examples 1-5 is used to replace the polyurethane A prepared in Example 1-1.

[0052] Example 6, an antibacterial wool fabric, differs from Example 1 in that an equal amount of polyurethane B prepared in Preparation Examples 2-4 is used to replace the polyurethane B prepared in Preparation Example 2-1.

[0053] Example 7, an antibacterial wool fabric, differs from Example 1 in that an equal amount of polyurethane B prepared in Preparation Examples 2-5 is used to replace the polyurethane B prepared in Preparation Example 2-1.

[0054] Comparative Example 1, an antibacterial wool fabric, differs from Example 1 in that an equal amount of polyurethane A prepared in Preparation Example 1-1 is used to replace polyurethane B prepared in Preparation Example 2-1.

[0055] Comparative Example 2, an antibacterial wool fabric, differs from Example 1 in that an equal amount of polyurethane B prepared in Preparation Example 2-1 is used to replace polyurethane A prepared in Preparation Example 1-1.

[0056] Comparative Example 3, an antibacterial wool fabric, differs from Example 1 in that a commercially available waterborne polyurethane (Guangzhou Aimeike, brand name IMK-119, solid content 35%) is used instead of polyurethane A obtained in Preparation Example 1-1 and polyurethane B obtained in Preparation Example 2-1.

[0057] Performance testing Experiment 1: Water Contact Angle Test Three 5cm × 5cm flat samples were cut from the back of the antibacterial sweaters prepared in each embodiment and comparative example (skin contact surface) and conditioned for 24 hours under standard atmospheric conditions (temperature 20±2℃, relative humidity 65±4%). The static contact angle method was used for testing according to GB / T 42694-2023 "Detection and Evaluation of Wetting Resistance of Textile Surfaces - Contact Angle and Roll-Off Angle Methods". The sample was fixed flat on a glass slide, and (5±0.5) μL of deionized water or grade III water was dropped onto the fabric surface using a microsyringe. Within (60±5) seconds after the droplet contacted the sample, the image of the droplet was captured by the CCD camera of an optical contact angle measuring instrument, and the contact angle was automatically calculated by software. At least 5 points were tested on each sample at different locations, and the results were expressed as the arithmetic mean of all measurements, rounded to the nearest integer.

[0058] Experiment 2: Flexibility Test The finishing liquids prepared in each embodiment and comparative example were coated into a uniform liquid film on a clean polytetrafluoroethylene (PTFE) plate using a four-sided coating tool. The film was then allowed to level naturally at room temperature for 24 hours. It was then transferred to an oven, heated to 60°C, dried for 4 hours, and then cured at 100°C for 30 minutes. After cooling, the film was carefully peeled off the substrate and equilibrated under standard atmospheric conditions for 24 hours. Rectangular coating samples of 50mm × 10mm were cut, with a thickness controlled at 0.20 ± 0.02mm. The test was conducted according to the principle of GB / T 1731-2020, "Determination of Flexibility of Paint Films and Putty Films". The coating sample was bent 180° against shafts of different diameters, held for 3 seconds, and then removed. The surface of the coating was observed using a 4x magnifying glass to check for cracks or peeling. The smallest shaft diameter that did not cause coating damage was recorded to characterize the flexibility.

[0059] Test 3: Antibacterial durability test Antibacterial wool sweaters prepared according to the examples and comparative examples were subjected to standard household washing according to the 4N procedure in GB / T 8629-2017, with a water temperature of 40±3℃ and AATCC 1993 standard detergent. After washing, the sweaters were dried. After 0, 10, 20, and 30 washing cycles, circular samples with a diameter of approximately 1 cm were cut from the fabric, and 0.75±0.05 g were weighed as antibacterial test samples. The fabric needed to be equilibrated under standard atmospheric conditions for 24 hours before washing. The test was conducted according to GB / T 20944.3-2008 "Evaluation of Antibacterial Properties of Textiles Part 3: Shaking Method", using Staphylococcus aureus (ATCC 6538) as the test species. 0.75 g of the sample was added to a solution containing 70 mL of PBS buffer and 5 mL of bacterial suspension (concentration 3×10⁻⁶). 5 In Erlenmeyer flasks containing (CFU / mL) bacteria, incubate at 24±1℃ and 150 rpm for 18 hours with shaking. After incubation, determine the colony count using the plate count method and calculate the inhibition rate using the following formula:

[0060] Inhibition rate (%) = (Count of colonies in control sample - Count of colonies in test sample) / Count of colonies in control sample × 100

[0061] Table 1 Performance Test Results

[0062] Example 4 (compared to Example 1) shows a polyurethane A prepared using low-viscosity amino silicone oil (4.2 mm² / s). Its water contact angle and antibacterial rate after washing decreased significantly, and its flexibility also decreased to some extent. This may be because when the viscosity of the amino silicone oil is too low, the grafted organosilicon segments are too short, failing to form a continuous and complete low surface energy hydrophobic layer at the membrane-air interface. This significantly weakens the water-repellent effect, allowing water molecules to easily penetrate into the membrane, leading to swelling and dissolution of the antibacterial agent, resulting in a marked deterioration in wash resistance and antibacterial durability.

[0063] Example 5 describes polyurethane A prepared using high-viscosity amino silicone oil (500 mm² / s). Its water contact angle and antibacterial rate after washing significantly deteriorated, and its flexibility decreased. This may be because when the viscosity of the amino silicone oil is too high, the viscosity of the reaction system increases sharply, the grafting reaction efficiency decreases, unreacted silicone oil disrupts the emulsion stability, and the uniformity of the hydrophobic layer deteriorates. Simultaneously, excessively long silicone segments may lead to intensified phase separation, increased internal stress in the coating, and negatively impact both flexibility and washability.

[0064] Example 6 uses polyurethane B prepared with low molecular weight amino polyether. Its water contact angle is similar to that of Example 1, but the antibacterial rate decreases more significantly after repeated washing. The reason may be that when the molecular weight of amino polyether is too low, the polyether chain segments are too short, resulting in insufficient ability to improve the wettability of the finishing solution on the wool cuticle layer, increased interfacial defects between the coating and the fiber, reduced chemical anchoring points, weakened adhesion, and the coating is more prone to local peeling during repeated washing, leading to faster loss of antibacterial agent.

[0065] Example 7 uses polyurethane B prepared with high molecular weight amino polyether. Its water contact angle is similar to that of Example 1, but the antibacterial rate decreases significantly after multiple washes. The reason may be that when the molecular weight of amino polyether is too high, the terminal amino groups are wrapped by long chains, resulting in a significant steric hindrance effect. The Michael addition grafting rate decreases significantly, and the actual number of amino polyethers bonded to the end of the polyurethane is insufficient. This weakens the affinity and anchoring effect with wool fibers, reduces coating adhesion, and impairs wash resistance and durable antibacterial properties.

[0066] Comparative Example 1 used only polyurethane A without compounding polyurethane B. Its initial water contact angle reached 120°, exhibiting excellent flexibility (1 mm). This indicates that the silicone segments were sufficiently enriched on the surface to form a complete hydrophobic layer. However, the antibacterial rate decreased sharply after multiple washes. This may be because the lack of wetting, spreading, and anchoring effects provided by the hydrophilic polyurethane B resulted in insufficient adhesion between the coating and the wool fibers. Under the mechanical force of washing, the coating easily peeled off, and the antibacterial agent was rapidly lost along with the coating.

[0067] Comparative Example 2 used only polyurethane B without compounding polyurethane A. Its water contact angle was only 68°, and its flexibility was reduced. The initial antibacterial rate could still reach 99.5%, but the antibacterial rate deteriorated significantly after multiple washes. The reason may be that without the surface hydrophobic siloxane barrier provided by polyurethane A, water molecules can freely penetrate into the interior of the membrane, causing swelling of the polyether segments, increasing the internal stress of the membrane and generating microcracks. The embedded antibacterial agent dissolves rapidly, and the water resistance deteriorates sharply.

[0068] Comparative Example 3 used commercially available unmodified waterborne polyurethane to replace polyurethane A and polyurethane B in equal amounts. Its water contact angle was only 75°, and its flexibility was only sufficient to withstand bending of a 5mm shaft. Although the initial antibacterial rate reached 99.5%, it dropped sharply after multiple washes. This indicates that commercially available conventional waterborne polyurethane lacks the surface hydrophobic shielding function provided by end-group silicone segments. Its polymer film has poor water resistance, absorbing water and swelling severely during washing. Internal stress induces microcracks that continue to propagate, eventually leading to film cracking or even peeling off in sheets, with the embedded antibacterial agent rapidly dissolving and being lost. Regarding flexibility, conventional polyurethane lacks the internal plasticizing effect of long-chain end groups, resulting in a brittle coating that easily cracks when bent.

[0069] Although this application has been disclosed above with reference to preferred embodiments, it is not intended to limit this application. Any person skilled in the art can make possible changes and modifications to the technical solutions of this application by utilizing the methods and techniques disclosed above without departing from the spirit and scope of this application. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of this application without departing from the content of the technical solutions of this application shall fall within the protection scope of the technical solutions of this application.

Claims

1. A durable antibacterial finishing solution, characterized in that, The raw materials include the following parts by weight: The mixture comprises 10-20 parts of waterborne polyurethane, 1-5 parts of antibacterial agent, 0.5-2 parts of penetrant, 1-3 parts of dispersant, and 50-120 parts of deionized water; the waterborne polyurethane includes polyurethane A and polyurethane B in a mass ratio of 1:0.4-0.8, wherein polyurethane A is prepared by Michael addition reaction of polyurethane containing acrylate end groups with amino silicone oil; and polyurethane B is prepared by Michael addition reaction of polyurethane containing acrylate end groups with amino polyether.

2. The durable antibacterial finishing solution according to claim 1, characterized in that, The preparation method of the acrylate-containing polyurethane is as follows: Polyether polyol, diisocyanate and chain extender are reacted to obtain polyurethane prepolymer with isocyanate end groups; A polyurethane prepolymer is subjected to a capping reaction with hydroxy acrylate to obtain a polyurethane containing acrylate end groups.

3. The durable antibacterial finishing solution according to claim 2, characterized in that, In the raw materials of the polyurethane containing acrylate groups, the molar ratio of the polyether polyol, chain extender, hydroxy acrylate and diisocyanate is 1:0.8-1.5:0.2-1.0:2.2-2.

8.

4. The durable antibacterial finishing solution according to claim 2, characterized in that, The hydroxyacrylate is selected from at least one of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, and hydroxybutyl methacrylate.

5. The durable antibacterial finishing solution according to claim 1, characterized in that, The viscosity of the amino silicone oil is 10-100 mm. 2 / s.

6. The durable antibacterial finishing solution according to claim 1, characterized in that, The number-average molecular weight of the amino polyether is 600–2000 g / mol.

7. The durable antibacterial finishing solution according to claim 1, characterized in that, The molar ratio of acrylate groups to amino groups in the amino silicone oil in the polyurethane containing acrylate end groups is 1:2.0 to 2.2; the molar ratio of acrylate groups to amino groups in the amino polyether in the polyurethane containing acrylate end groups is 1:1.0 to 2.

2.

8. The durable antibacterial finishing solution according to claim 1, characterized in that, The Michael addition reaction is carried out at a temperature of 50–70°C for 3–8 hours.

9. The durable antibacterial finishing solution according to claim 1, characterized in that, The antibacterial agent is selected from at least one of nano silver, nano zinc oxide, quaternary ammonium salt antibacterial agents, guanidine antibacterial agents, chitosan and its derivatives; and / or, the penetrant is selected from at least one of fatty alcohol polyoxyethylene ether, alkyl sulfonate, alkylbenzene sulfonate, and JFC penetrant; and / or, the dispersant is selected from at least one of polycarboxylate, polyacrylate, and naphthalene sulfonate formaldehyde condensate.

10. An antibacterial wool fabric, characterized in that, It is prepared by padding with the durable antibacterial finishing liquid described in any one of claims 1 to 9, with a bath ratio of 1:8 to 12, a padding rate of 70 to 80%, a finishing temperature of 40 to 80°C, and a finishing time of 20 to 60 minutes.

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