A bio-based itaconate rubber emulsion modified and compounded antibacterial agent nitrile glove and a preparation method thereof

Abstract

This invention belongs to the field of polymer protective materials technology, and discloses a nitrile glove modified with bio-based itaconic acid ester rubber latex and compounded with an antibacterial agent, as well as its preparation method. The glove uses carboxylated nitrile butadiene latex as the matrix, introduces a bio-based itaconic acid ester rubber latex pretreated with a silane coupling agent as a reactive interfacial compatibility component, and uses nano-silver-zinc composite particles and reactive quaternized chitosan to form an immobilized composite antibacterial phase. The glove is prepared through blending, impregnation molding, surface immobilization treatment, gradient vulcanization, and post-treatment. The resulting glove possesses excellent flexibility, low-temperature embrittlement resistance, oil resistance, and long-lasting antibacterial properties, and the antibacterial components are not easily migrated or detached, making it suitable for food processing, medical auxiliary protection, and low-temperature operations.

Description

Technical Field

[0001] This invention belongs to the field of polymer protective materials technology, specifically relating to a nitrile glove modified with bio-based itaconic acid ester rubber latex and compounded with antibacterial agents, and its preparation method. Background Technology

[0002] Nitrile gloves, due to their absence of natural rubber proteins and their superior resistance to oils, acids, alkalis, abrasion, and barrier properties, are widely used in household cleaning, food processing, catering services, industrial protection, and medical auxiliary protection. Compared to natural latex gloves, nitrile gloves effectively avoid protein allergy issues, leading to continued market demand growth. However, as protective equipment evolves towards high performance, multifunctionality, comfort, and environmental friendliness, existing nitrile gloves still have many shortcomings and struggle to meet the requirements of complex working conditions.

[0003] Traditional nitrile latex molecules have strong polarity and high segment rigidity. While gloves made from this latex possess good basic mechanical properties and oil resistance, their flexibility, resilience, and wearing comfort still need improvement. Particularly in low-temperature environments, they are prone to hardening, embrittlement, and even cracking, limiting their application in cold chain logistics, low-temperature processing, and winter outdoor work. Secondly, ordinary nitrile gloves typically lack active antibacterial functions. During food processing, medical care, and public health protection, bacteria easily adhere to and proliferate on the glove surface, posing a risk of cross-contamination. Existing antibacterial nitrile gloves mostly achieve their antibacterial effect by directly adding inorganic or organic antibacterial agents to the latex system. However, these generally suffer from insufficient compatibility with the latex system, easy aggregation, easy migration and shedding, poor antibacterial durability, and impact on mechanical properties. Furthermore, existing nitrile glove modification technologies mostly focus on improving a single property, such as only improving softness, only enhancing antibacterial properties, or only strengthening oil resistance, failing to achieve a synergistic improvement in flexibility, low-temperature performance, oil resistance, mechanical properties, and antibacterial properties. Summary of the Invention

[0004] To address the shortcomings mentioned in the background art, the present invention aims to provide a nitrile glove modified with a bio-based itaconic acid ester rubber latex and compounded with an antibacterial agent, and a method for preparing the same. The method uses carboxyl-based nitrile butadiene latex as the matrix, introduces a bio-based itaconic acid ester rubber latex pretreated with a silane coupling agent, and compoundes it with an immobilized composite antibacterial phase composed of nano-silver-zinc composite particles and reactive quaternized chitosan, thereby improving the flexibility, low-temperature performance, oil resistance, and long-lasting antibacterial properties of the nitrile glove.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A nitrile glove modified with a bio-based itaconic acid ester rubber latex and compounded with an antibacterial agent is prepared from the following raw materials in parts by weight: 100 parts of carboxylated nitrile rubber latex, 18-38 parts of bio-based itaconic acid ester rubber latex, 1.5-6 parts of immobilized composite antibacterial phase, 0.7-2.3 parts of vulcanizing agent, 1.3-3.6 parts of vulcanization accelerator, 1.1-2.6 parts of vulcanization activator, 0.5-1.3 parts of stabilizer, 0.4-1.0 parts of thickener, 0.3-0.9 parts of antioxidant, 0.2-1.0 parts of silane coupling agent, and 28-48 parts of deionized water;

[0007] The immobilized composite antibacterial phase includes nano-silver-zinc composite particles and a reactive quaternary ammonium salting chitosan carrier, and the bio-based itaconic acid ester rubber latex is a reactive interfacial compatibility component pretreated with a silane coupling agent.

[0008] More preferably, the carboxyl butadiene nitrile latex has a carboxyl content of 5-9% and a solid content of 40-50%; the bio-based itaconic acid ester rubber latex has a solid content of 45-60% and a viscosity of 400-1500 mPa·s.

[0009] More preferably, the bio-based itaconic acid ester rubber latex is obtained by emulsion polymerization of itaconic acid ester monomers and diene monomers; the itaconic acid ester monomers are selected from one or two of di-n-butyl itaconic acid and dimethyl itaconic acid; the diene monomers are selected from one or two of butadiene and isoprene; the mass ratio of the itaconic acid ester monomers to the diene monomers is 4:1-9:1.

[0010] More preferably, the reactive quaternized chitosan carrier is prepared by further introducing reactive groups into quaternized chitosan; the reactive groups are selected from one or more of amino, epoxy, methacryloxy, and hydrolyzable silane groups; the degree of deacetylation of the reactive quaternized chitosan is not less than 90%.

[0011] More preferably, the particle size of the nano-silver-zinc composite particles is 20-40 nm, and the silver-zinc mass ratio is 1:3-1:5; the mass ratio of the nano-silver-zinc composite particles to the reactive quaternary ammonium salted chitosan carrier is 2:1-6:1.

[0012] More preferably, the silane coupling agent is selected from one or two of KH-550, KH-560, and KH-570; the silane coupling agent is used for the pretreatment of bio-based itaconic acid ester rubber latex and for the interfacial fixation between the immobilized composite antibacterial phase and the latex system.

[0013] More preferably, the vulcanizing agent is selected from sulfur and dicumyl peroxide; the vulcanization accelerator is selected from one or more of sodium dibutyldithiocarbamate, 2-mercaptobenzothiazole, and tetramethylthiuram disulfide; the vulcanization activator is a compound of zinc oxide and stearic acid; the stabilizer is selected from one or a compound of two of sodium fatty alcohol ether sulfate, sodium dodecylbenzenesulfonate, and polyvinylpyrrolidone; the thickener is selected from hydroxyethyl cellulose, xanthan gum, and guar gum; and the antioxidant is selected from antioxidant 4020, antioxidant RD, and antioxidant MB.

[0014] A method for preparing a nitrile glove modified with a bio-based itaconic acid ester rubber latex and compounded with an antibacterial agent includes the following steps:

[0015] S1. Quaternized chitosan is pretreated with a silane coupling agent in an acidic aqueous solution to obtain a reactive quaternized chitosan dispersion. Nano-silver-zinc composite particles are added to the reactive quaternized chitosan dispersion and ultrasonically dispersed at 300-500 W and 30-40℃ to obtain an immobilized composite antibacterial phase dispersion.

[0016] S2. The bio-based itaconic acid ester rubber latex is pretreated with a silane coupling agent at 45-55℃ to obtain a reactive interface compatibility component. The carboxylated butadiene nitrile latex, the reactive interface compatibility component and the immobilized composite antibacterial phase dispersion are then blended. The pH of the system is adjusted to 8.5-9.5 and the viscosity is adjusted to 650-950 mPa·s to obtain a modified latex composition.

[0017] S3. After treating the hand mold with a calcium chloride coagulant of 17-23% by mass, it is immersed in the modified latex composition for molding and pre-baking to obtain a semi-finished glove.

[0018] S4. The semi-finished gloves are immersed in a surface treatment solution containing an immobilized composite antibacterial phase for surface immobilization treatment.

[0019] S5. The semi-finished gloves after surface fixation treatment are vulcanized using a gradient heating method, first pre-vulcanized at 90-95℃, and then main vulcanized at 110-125℃.

[0020] S6. The vulcanized glove semi-finished product is subjected to chlorination, washing, drying, demolding and edge rolling in sequence to obtain the nitrile gloves.

[0021] More preferably, in S1, the reactive pretreatment time of quaternized chitosan is 30-120 min, and the ultrasonic dispersion time of the nano-silver-zinc composite particles in the reactive quaternized chitosan dispersion is 25-35 min; in S2, the pretreatment time of the bio-based itaconic acid ester rubber latex is 25-35 min; and in S3, the pre-drying temperature is 75-85℃, and the pre-drying time is 25-35 min.

[0022] More preferably, in S2, the carboxylated nitrile latex is blended with the reactive interface compatibility component for 35-45 min; in S4, the surface immobilization treatment involves immersing the semi-finished glove in a 0.3-2.5% (w / w) immobilized composite antibacterial phase surface treatment solution for 10-20 s, draining for 10-20 s, and then drying at 60-90℃ for 3-10 min; in S5, the pre-vulcanization time is 10-15 min, and the main vulcanization time is 35-45 min; in S6, the chlorination treatment uses a 0.7-1.3% (w / w) sodium hypochlorite solution with a pH of 8-10, a treatment temperature of 20-30℃, and is carried out under gentle stirring.

[0023] The beneficial effects of this invention are:

[0024] This invention introduces a bio-based itaconic acid ester rubber latex pretreated with a silane coupling agent into a carboxylated nitrile butadiene latex system, constructing a more stable reactive interfacial compatibility structure. This results in a tighter interfacial bond between the bio-based flexible phase and the nitrile butadiene matrix, reducing the tendency for phase separation during film formation and vulcanization, and significantly improving stress transfer efficiency. Consequently, the resulting gloves possess high tensile strength, elongation at break, and good resilience, while also addressing the shortcomings of traditional nitrile butadiene gloves, such as brittleness and cracking at low temperatures. Furthermore, this invention employs nano-silver-zinc composite particles and reactive quaternized chitosan to construct an immobilized composite antibacterial phase. Through silane coupling and interfacial fixation, this phase is stably anchored to the crosslinked network nodes and the glove surface. This not only enhances the bonding strength between the antibacterial components and the latex system, reducing the risk of migration, precipitation, and detachment of the antibacterial components during use, washing, and friction, but also effectively improves the antibacterial efficiency and durability of the glove surface. At the same time, the surface enrichment treatment concentrates the antibacterial function mainly on the outer surface of the glove, ensuring high antibacterial efficiency while reducing the negative impact of antibacterial components on bulk mechanical properties and flexibility. Detailed Implementation

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] In the following examples, the weight parts of each component are converted to grams proportionally for feeding, i.e., 1 part is counted as 1 g; the water used in the acidic aqueous solution in each example is included in the total amount of deionized water.

[0027] Example 1

[0028] A nitrile glove modified with bio-based itaconic acid ester rubber latex and compounded with an antibacterial agent is prepared from the following raw materials in parts by weight: 100 parts carboxylated nitrile rubber latex, 18 parts bio-based itaconic acid ester rubber latex, 1.5 parts immobilized composite antibacterial phase, 0.7 parts vulcanizing agent, 1.3 parts vulcanization accelerator, 1.1 parts vulcanization activator, 0.5 parts stabilizer, 0.4 parts thickener, 0.3 parts antioxidant, 0.2 parts silane coupling agent, and 28 parts deionized water;

[0029] The carboxyl-based nitrile butadiene latex has a carboxyl content of 5% and a solid content of 40%. The bio-based itaconic acid ester rubber latex has a solid content of 45% and a viscosity of 400 mPa·s, and is prepared by emulsion polymerization of di-n-butyl itaconic acid and butadiene at a mass ratio of 4:1. In the immobilized composite antibacterial phase, the nano-silver-zinc composite particles have a particle size of 20 nm, a silver-zinc mass ratio of 1:3, a mass ratio of nano-silver-zinc composite particles to reactive quaternary ammonium salted chitosan carrier of 2:1, a degree of deacetylation of reactive quaternary ammonium salted chitosan of 90%, and its reactive groups are epoxy and methacryloyloxy groups. The silane coupling agents are KH-560 and KH-570, with a mass ratio of 1:1.

[0030] The preparation steps are as follows:

[0031] S1. Weigh 0.5 g of quaternized chitosan and add it to 5.0 g of acetic acid aqueous solution with a mass fraction of 1.0%. Stir to disperse it evenly, then add 0.1 g of KH-560 and stir to react at 30℃ for 30 min. Then add 1.0 g of nano silver-zinc composite particles and ultrasonically disperse at 300 W and 30℃ for 25 min to obtain an immobilized composite antibacterial phase dispersion.

[0032] S2. Weigh 18.0 g of bio-based itaconic acid ester rubber latex, add 0.1 g of KH-570, and stir at 600 r / min for 25 min at 45℃ to obtain pretreated bio-based itaconic acid ester rubber latex; separately, add 100.0 g of carboxylated nitrile rubber latex to a reaction vessel, heat to 38℃, add 23.0 g of deionized water and 0.5 g of sodium dodecylbenzene sulfonate, stir at 300 r / min for 12 min, then adjust the pH to 8.5 with 5% sodium bicarbonate solution, add the pretreated bio-based itaconic acid ester rubber latex, stir at 800 r / min for 35 min at 50℃, then add the immobilized composite antibacterial phase dispersion, stir at 250 r / min for 15 min, then add 0.73 g of zinc oxide, 0.37 g of stearic acid, 0.3 g of antioxidant 4020, 0.7 g of sulfur, and 1.3 g of other components. 0.4 g of sodium dibutyldithiocarbamate was stirred at 200 r / min for 25 min, and finally 0.4 g of hydroxyethyl cellulose was added to adjust the viscosity of the system to 650 mPa·s, thus obtaining a modified latex composition.

[0033] S3. Prepare a calcium chloride coagulant solution with a mass concentration of 17%. After degreasing, washing and drying the ceramic hand mold in sequence, immerse it in the coagulant for 7 seconds, take it out and dry it at 85°C for 12 minutes. Then immerse the treated hand mold in the modified latex composition for 13 seconds, lift it at a speed of 5 cm / s, let it drain naturally for 1 minute, and then pre-dry it at 75°C for 25 minutes to obtain a semi-finished glove.

[0034] S4. Prepare a surface treatment solution with a mass concentration of 0.3% for immobilized composite antibacterial phase. Immerse the semi-finished gloves in the surface treatment solution for 10 seconds, drain for 10 seconds, remove and dry at 60℃ for 3 minutes to complete the surface immobilization treatment.

[0035] S5. Place the semi-finished gloves after surface fixation treatment into a vulcanization oven, pre-vulcanize at 90℃ for 10 minutes, and then raise the temperature to 110℃ for main vulcanization for 35 minutes.

[0036] S6. Immerse the vulcanized glove semi-finished product in a 0.7% sodium hypochlorite solution for 4 seconds. The pH of the sodium hypochlorite solution is 8.5, the treatment temperature is 25°C, and the mixture is gently stirred during the treatment. After removal, wash the glove three times with deionized water, then dry it at 85°C for 18 minutes. Finally, demold the glove and roll the edges to obtain the finished nitrile glove.

[0037] Example 2

[0038] A nitrile glove modified with bio-based itaconic acid ester rubber latex and compounded with an antibacterial agent is prepared from the following raw materials in parts by weight: 100 parts of carboxylated nitrile rubber latex, 38 parts of bio-based itaconic acid ester rubber latex, 6 parts of immobilized composite antibacterial phase, 2.3 parts of vulcanizing agent, 3.6 parts of vulcanization accelerator, 2.6 parts of vulcanization activator, 1.3 parts of stabilizer, 1.0 part of thickener, 0.9 parts of antioxidant, 1.0 part of silane coupling agent, and 48 parts of deionized water;

[0039] The carboxyl-based nitrile butadiene latex has a carboxyl content of 9% and a solid content of 50%. The bio-based itaconic acid ester rubber latex has a solid content of 60% and a viscosity of 1500 mPa·s, and is prepared by emulsion polymerization of dimethyl itaconic acid and isoprene at a mass ratio of 9:1. In the immobilized composite antibacterial phase, the nano-silver-zinc composite particles have a particle size of 40 nm, a silver-zinc mass ratio of 1:5, a mass ratio of nano-silver-zinc composite particles to reactive quaternary ammonium salted chitosan carrier of 6:1, a degree of deacetylation of reactive quaternary ammonium salted chitosan of 95%, and its reactive groups are amino and hydrolyzable silyl groups. The vulcanization accelerator is 2-mercaptobenzothiazole and tetramethylthiuram disulfide, with a mass ratio of 3.5:1. The silane coupling agent is KH-550.

[0040] The preparation steps are as follows:

[0041] S1. Weigh 0.857 g of quaternized chitosan and add it to 8.0 g of acetic acid aqueous solution with a mass fraction of 2.0%. After dispersing evenly, add 0.5 g of KH-550 and react at 50℃ for 120 min. Then add 5.143 g of nano silver-zinc composite particles and ultrasonically disperse at 500 W and 40℃ for 35 min to obtain an immobilized composite antibacterial phase dispersion.

[0042] S2. Weigh 38.0 g of bio-based itaconic acid ester rubber latex, add 0.5 g of KH-550, and stir for 35 min at 55℃ and 800 r / min to obtain pretreated bio-based itaconic acid ester rubber latex; separately, add 100.0 g of carboxylated nitrile butadiene latex to a reaction vessel, heat to 48℃, add 40.0 g of deionized water, 0.9 g of fatty alcohol ether sodium sulfate and 0.4 g of polyvinylpyrrolidone, stir at 400 r / min for 18 min, and then adjust the pH of the system to 9.5 with 3% sodium hydroxide solution; then add the pretreated bio-based itaconic acid ester rubber latex, mix at 55℃ and 1200 r / min for 45 min, then add the immobilized composite antibacterial phase dispersion, stir at 350 r / min for 20 min, and then add 1.95 g of zinc oxide, 0.65 g of stearic acid, 0.9 g of antioxidant MB, 2.3 g of sulfur and 2.8 g of... 2-Mercaptobenzothiazole and 0.8 g tetramethylthiuram disulfide were stirred at 300 r / min for 35 min, and finally 1.0 g guar gum was added to adjust the viscosity of the system to 950 mPa·s to obtain a modified latex composition.

[0043] S3. Prepare a calcium chloride coagulant solution with a mass concentration of 23%. After degreasing, washing and drying the ceramic hand mold in sequence, immerse it in the coagulant for 13 seconds, take it out and dry it at 95℃ for 18 minutes. Then immerse the treated hand mold in the modified latex composition for 23 seconds, lift it at a speed of 8 cm / s, let it drain naturally for 3 minutes, and then pre-dry it at 85℃ for 35 minutes to obtain a semi-finished glove.

[0044] S4. Prepare a surface treatment solution with a mass concentration of 2.5% for immobilized composite antibacterial phase. Immerse the semi-finished gloves in the surface treatment solution for 20 seconds, remove them and drain for 20 seconds, then dry them at 90℃ for 10 minutes to complete the surface immobilization treatment.

[0045] S5. Place the semi-finished gloves after surface fixation treatment into a vulcanization oven, pre-vulcanize at 95℃ for 15 minutes, and then raise the temperature to 125℃ for main vulcanization for 45 minutes.

[0046] S6. Immerse the vulcanized glove semi-finished product in a 1.3% sodium hypochlorite solution for 6 seconds. The pH of the sodium hypochlorite solution is 9.5, the treatment temperature is 25°C, and the mixture is gently stirred during the treatment. After removal, wash the glove 5 times with deionized water, then dry it at 95°C for 25 minutes. Finally, demold the glove and roll the edges to obtain the finished nitrile glove.

[0047] Example 3

[0048] A nitrile glove modified with bio-based itaconic acid ester rubber latex and compounded with an antibacterial agent is prepared from the following raw materials in parts by weight: 100 parts of carboxylated nitrile rubber latex, 28 parts of bio-based itaconic acid ester rubber latex, 3.75 parts of immobilized composite antibacterial phase, 1.5 parts of vulcanizing agent, 2.45 parts of vulcanization accelerator, 1.85 parts of vulcanization activator, 0.9 parts of stabilizer, 0.7 parts of thickener, 0.6 parts of antioxidant, 0.6 parts of silane coupling agent, and 38 parts of deionized water.

[0049] The carboxyl-based nitrile butadiene latex has a carboxyl content of 7% and a solid content of 45%. The bio-based itaconic acid ester rubber latex has a solid content of 52.5% and a viscosity of 950 mPa·s, and is prepared by emulsion polymerization of di-n-butyl itaconic acid and isoprene at a mass ratio of 6.5:1. In the immobilized composite antibacterial phase, the nano-silver-zinc composite particles have a particle size of 30 nm, a silver-zinc mass ratio of 1:4, a mass ratio of nano-silver-zinc composite particles to reactive quaternized chitosan carrier of 4:1, a degree of deacetylation of reactive quaternized chitosan of 92.5%, and reactive groups of epoxy and methacryloyloxy groups. The silane coupling agents are KH-560 and KH-570, with a mass ratio of 1:1.

[0050] The preparation steps are as follows:

[0051] S1. Add 6.5 g of acetic acid aqueous solution with a mass fraction of 1.5% to the container, then add 0.75 g of quaternized chitosan and stir until there is no obvious agglomeration. Then add 0.3 g of KH-560 and maintain the reaction at 40℃ for 75 min. After the reaction is completed, add 3.0 g of nano silver-zinc composite particles and sonicate at 400 W and 35℃ for 30 min to obtain an immobilized composite antibacterial phase dispersion.

[0052] S2. Take another 28.0 g of bio-based itaconic acid ester rubber latex, add 0.3 g of KH-570, and treat at 50℃ and 700 r / min for 30 min; then add 100.0 g of carboxylated nitrile butadiene latex to the reactor, heat to 43℃, then add 31.5 g of deionized water, 0.6 g of fatty alcohol ether sodium sulfate and 0.3 g of polyvinylpyrrolidone, stir at 350 r / min for 15 min, and adjust the pH of the system to 9.0 with 8% sodium bicarbonate solution; then add the pretreated bio-based itaconic acid ester rubber latex, mix at 52℃ and 1000 r / min for 40 min, then add the immobilized composite antibacterial phase dispersion, continue stirring at 300 r / min for 18 min, then add 1.23 g of zinc oxide, 0.62 g of stearic acid, 0.6 g of antioxidant RD, 1.5 g of sulfur, and 1.90 g of... 2-Mercaptobenzothiazole and 0.55 g tetramethylthiuram disulfide were stirred at 250 r / min for 30 min, and finally 0.7 g xanthan gum was added to adjust the viscosity of the system to 800 mPa·s to obtain a modified latex composition.

[0053] S3. Prepare a coagulant solution with a mass concentration of 20% calcium chloride. After the ceramic hand mold has been degreased, washed and dried, immerse it in the coagulant for 10 seconds, remove it and dry it at 90℃ for 15 minutes. Then immerse the hand mold in the modified latex composition for 18 seconds, remove it at a speed of 6 cm / s, let it stand and filter for 2 minutes, and then pre-dry it at 80℃ for 30 minutes to obtain a semi-finished glove.

[0054] S4. Immerse the obtained semi-finished gloves in a 1.5% (w / w) immobilized composite antibacterial phase surface treatment solution for 15 seconds, remove and drain for 15 seconds, then dry at 75°C for 7 minutes to complete the surface immobilization treatment.

[0055] S5. Send the semi-finished gloves with the completed surface treatment into the vulcanization oven, pre-vulcanize at 93℃ for 13 min, and then raise the temperature to 118℃ for main vulcanization for 40 min.

[0056] S6. After vulcanization, the semi-finished gloves are immersed in a 1.0% sodium hypochlorite solution for 5 seconds. The sodium hypochlorite solution has a pH of 9 and a treatment temperature of 25°C. The mixture is gently stirred during the treatment. The gloves are then washed four times with deionized water and dried at 90°C for 22 minutes. Finally, they are demolded and rolled at the edges to obtain the finished nitrile gloves.

[0057] Comparative Example 1: Without quaternized chitosan silane reactive pretreatment, the immobilized composite antibacterial phase was replaced with a conventional physical mixed antibacterial phase.

[0058] In step S1 of this comparative example, the quaternized chitosan was not subjected to silane coupling agent reactive pretreatment. Instead, 0.75 g of quaternized chitosan was dispersed in 6.5 g of 1.5% acetic acid aqueous solution, and 3.0 g of nano silver-zinc composite particles were added. The mixture was ultrasonically dispersed at 400 W and 35 °C for 30 min to obtain a physically mixed antibacterial phase dispersion. In step S4, a 1.5% physical mixed antibacterial phase surface treatment solution was used for treatment, followed by immersion for 15 s and draining for 15 s. The composition, dosage, and preparation steps of the remaining raw materials were the same as in Example 3.

[0059] Comparative Example 2: Silane Coupling Agent Pretreatment of Bio-based Itaconic Acid Ester Rubber Latex

[0060] In step S2 of this comparative example, the 28.0 g bio-based itaconic acid ester rubber latex was not pretreated with a silane coupling agent, but was directly added to the carboxylated nitrile rubber latex system for blending; the composition, amount and preparation steps of the other raw materials were the same as in Example 3.

[0061] Comparative Example 3: No surface immobilization treatment

[0062] In this comparative example, step S4 is omitted, and surface immobilization treatment is not performed; the remaining raw material composition, dosage, and preparation steps are the same as in Example 3.

[0063] Comparative Example 4: Unimmobilized composite antibacterial phase

[0064] In this comparative example, no nano-silver-zinc composite particles were added in step S1, and an equal mass of deionized water was used to replace the nano-silver-zinc composite particles in the dispersion system. In step S4, a blank surface treatment solution containing only reactive quaternary ammonium salted chitosan but without nano-silver-zinc composite particles was used for treatment. The composition, amount and preparation steps of the remaining raw materials were the same as in Example 3.

[0065] Performance testing

[0066] The performance of the nitrile gloves prepared in Examples 1-3 and Comparative Examples 1-4 was tested. Tensile strength and elongation at break were determined according to ASTM D6319. After being subjected to a -20℃ low-temperature treatment, the tensile strength after low-temperature testing was determined according to the tensile test method in ASTM D6319, and the occurrence of embrittlement and cracking was observed. Oil swelling resistance was determined according to GB / T 1690-2010, using standard oil #1, and measured after immersion at 25℃ for 24 h. Antibacterial rate, antibacterial rate after washing, and antibacterial rate after friction were determined according to GB / T 31402-2023 to assess the antibacterial effects against *Escherichia coli* and *Staphylococcus aureus*. The antibacterial rate after washing was the result of 50 standard water washes, and the antibacterial rate after friction was the result of repeated friction treatment under a specified load. The silver and zinc leaching amounts were determined using ICP-OES to measure the silver and zinc ion content in the extract, and the results are shown in Table 1 below.

[0067] Table 1 Performance results of Examples 1-3 and Comparative Examples 1-4

[0068] Testing items Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Tensile strength / MPa 33.2 38.6 36.0 35.1 32.4 35.6 31.2 Elongation at break / % 862 926 892 871 835 884 782 Tensile strength at -20℃ / MPa 32.8 38.0 35.5 33.8 29.6 34.2 Brittleness and cracking Oil swelling resistance / % 6.8 6.1 6.5 6.9 7.9 6.7 9.6 E. coli antibacterial rate / % 99.91 99.98 99.95 99.93 99.94 99.72 No obvious antibacterial effect Staphylococcus aureus antibacterial rate / % 99.90 99.97 99.95 99.92 99.93 99.70 No obvious antibacterial effect E. coli antibacterial rate after 50 washes / % 99.82 99.93 99.90 97.85 99.81 98.94 No obvious antibacterial effect Staphylococcus aureus antibacterial rate after 50 washes / % 99.81 99.92 99.89 97.63 99.79 98.91 No obvious antibacterial effect Antibacterial rate of E. coli after friction / % 99.76 99.89 99.85 98.96 99.80 98.26 No obvious antibacterial effect Antibacterial rate of Staphylococcus aureus after friction / % 99.74 99.88 99.84 98.90 99.78 98.18 No obvious antibacterial effect Silver leaching amount (mg·L⁻¹) 0.19 0.11 0.14 0.61 0.18 0.30 Not detected Zinc leaching amount (mg·L⁻¹) 0.37 0.24 0.30 1.34 0.36 0.59 Not detected

[0069] As shown in Table 1, the nitrile gloves prepared in Examples 1-3 all exhibit excellent tensile strength, elongation at break, low-temperature performance, and oil resistance. This indicates that the present invention, through modification with bio-based itaconic acid ester rubber latex, can significantly improve the flexibility, low-temperature embrittlement resistance, and oil resistance of gloves while maintaining high mechanical properties.

[0070] Compared to Example 3, Comparative Example 1, with a similar initial antibacterial rate, showed a significant decrease in antibacterial rate after 50 washes and after friction, and a significant increase in silver and zinc leaching. This indicates that the unimmobilized physically mixed antibacterial phase is more prone to migration and detachment, resulting in poor antibacterial durability. Comparative Example 2 showed inferior tensile strength, elongation at break, low-temperature tensile strength, and oil swelling resistance compared to Example 3, indicating that pretreatment with a silane coupling agent effectively improves the interfacial compatibility between the bio-based itaconic acid ester rubber latex and the carboxylated nitrile rubber latex, thereby improving the overall performance of the system. Although Comparative Example 3 had a higher initial antibacterial rate, the decrease in antibacterial rate after washing and friction was significant, indicating that surface immobilization treatment helps improve the enrichment and binding strength of the immobilized composite antibacterial phase on the glove surface, thus enhancing antibacterial durability. Comparative Example 4 did not exhibit significant antibacterial activity, and silver and zinc leaching was undetectable, further demonstrating that the immobilized composite antibacterial phase is the key factor in imparting efficient and long-lasting antibacterial properties to the gloves in this invention. In summary, this invention achieves simultaneous improvement in the mechanical properties, low-temperature performance, oil resistance, and antibacterial durability of nitrile gloves through the synergistic effects of reactive interface compatibility, immobilized composite antibacterial phase construction, and surface immobilization treatment.

[0071] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0072] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A nitrile glove modified with a bio-based itaconic acid ester rubber latex and compounded with an antibacterial agent, characterized in that, It is prepared from the following raw materials in parts by weight: 100 parts carboxylated nitrile latex, 18-38 parts bio-based itaconic acid ester rubber latex, 1.5-6 parts immobilized composite antibacterial phase, 0.7-2.3 parts vulcanizing agent, 1.3-3.6 parts vulcanization accelerator, 1.1-2.6 parts vulcanization activator, 0.5-1.3 parts stabilizer, 0.4-1.0 parts thickener, 0.3-0.9 parts antioxidant, 0.2-1.0 parts silane coupling agent, and 28-48 parts deionized water; The immobilized composite antibacterial phase includes nano-silver-zinc composite particles and a reactive quaternary ammonium salting chitosan carrier, and the bio-based itaconic acid ester rubber latex is a reactive interfacial compatibility component pretreated with a silane coupling agent.

2. The nitrile gloves according to claim 1, characterized in that, The carboxyl nitrile butadiene latex has a carboxyl content of 5-9% and a solid content of 40-50%; the bio-based itaconic acid ester rubber latex has a solid content of 45-60% and a viscosity of 400-1500 mPa·s.

3. The nitrile gloves according to claim 1, characterized in that, The bio-based itaconic acid ester rubber latex is prepared by emulsion polymerization of itaconic acid ester monomers and diene monomers; the itaconic acid ester monomers are selected from one or two of di-n-butyl itaconic acid and dimethyl itaconic acid; the diene monomers are selected from one or two of butadiene and isoprene; the mass ratio of the itaconic acid ester monomers to the diene monomers is 4:1-9:

1.

4. The nitrile gloves according to claim 1, characterized in that, The reactive quaternized chitosan carrier is prepared by further introducing reactive groups into quaternized chitosan; the reactive groups are selected from one or more of amino, epoxy, methacryloxy, and hydrolyzable silane groups; the degree of deacetylation of the reactive quaternized chitosan is not less than 90%.

5. The nitrile gloves according to claim 1, characterized in that, The nano-silver-zinc composite particles have a particle size of 20-40 nm and a silver-zinc mass ratio of 1:3-1:5; the mass ratio of the nano-silver-zinc composite particles to the reactive quaternary ammonium salted chitosan carrier is 2:1-6:

1.

6. The nitrile gloves according to claim 1, characterized in that, The silane coupling agent is selected from one or two of KH-550, KH-560, and KH-570; the silane coupling agent is used for the pretreatment of bio-based itaconic acid ester rubber latex and for the interfacial fixation between the immobilized composite antibacterial phase and the latex system.

7. The nitrile gloves according to claim 1, characterized in that, The vulcanizing agent is selected from sulfur and dicumyl peroxide; the vulcanization accelerator is selected from one or more of sodium dibutyldithiocarbamate, 2-mercaptobenzothiazole, and tetramethylthiuram disulfide; the vulcanization activator is a compound of zinc oxide and stearic acid; the stabilizer is selected from one or a compound of two of sodium fatty alcohol ether sulfate, sodium dodecylbenzenesulfonate, and polyvinylpyrrolidone; the thickener is selected from hydroxyethyl cellulose, xanthan gum, and guar gum; and the antioxidant is selected from antioxidant 4020, antioxidant RD, and antioxidant MB.

8. A method for preparing a nitrile glove modified with bio-based itaconic acid ester rubber latex and compounded with an antibacterial agent as described in any one of claims 1-7, characterized in that, Includes the following steps: S1. Quaternized chitosan is pretreated with a silane coupling agent in an acidic aqueous solution to obtain a reactive quaternized chitosan dispersion. Nano-silver-zinc composite particles are added to the reactive quaternized chitosan dispersion and ultrasonically dispersed at 300-500 W and 30-40℃ to obtain an immobilized composite antibacterial phase dispersion. S2. The bio-based itaconic acid ester rubber latex is pretreated with a silane coupling agent at 45-55℃ to obtain a reactive interface compatibility component. The carboxylated butadiene nitrile latex, the reactive interface compatibility component and the immobilized composite antibacterial phase dispersion are then blended. The pH of the system is adjusted to 8.5-9.5 and the viscosity is adjusted to 650-950 mPa·s to obtain a modified latex composition. S3. After treating the hand mold with a calcium chloride coagulant of 17-23% by mass, it is immersed in the modified latex composition for molding and pre-baking to obtain a semi-finished glove. S4. The semi-finished gloves are immersed in a surface treatment solution containing an immobilized composite antibacterial phase for surface immobilization treatment. S5. The semi-finished gloves after surface fixation treatment are vulcanized using a gradient heating method, first pre-vulcanized at 90-95℃, and then main vulcanized at 110-125℃. S6. The vulcanized glove semi-finished product is subjected to chlorination, washing, drying, demolding and edge rolling in sequence to obtain the nitrile gloves.

9. The preparation method according to claim 8, characterized in that, In S1, the reactive pretreatment time for quaternized chitosan is 30-120 min, and the ultrasonic dispersion time of nano-silver-zinc composite particles in the reactive quaternized chitosan dispersion is 25-35 min; in S2, the pretreatment time for the bio-based itaconic acid ester rubber latex is 25-35 min; in S3, the pre-drying temperature is 75-85℃, and the pre-drying time is 25-35 min.

10. The preparation method according to claim 8, characterized in that, In S2, carboxylated nitrile latex is blended with reactive interface compatibility components for 35-45 min; in S4, the surface immobilization treatment involves immersing the semi-finished gloves in a 0.3-2.5% (w / w) immobilized composite antibacterial phase surface treatment solution for 10-20 s, draining for 10-20 s, and then drying at 60-90℃ for 3-10 min; in S5, the pre-vulcanization time is 10-15 min, and the main vulcanization time is 35-45 min; in S6, the chlorination treatment uses a 0.7-1.3% (w / w) sodium hypochlorite solution with a pH of 8-10, a treatment temperature of 20-30℃, and is carried out under gentle stirring.