An ammonia-free deproteinized latex medical surgical glove and a preparation method thereof

Abstract

The present application relates to the technical field of preparation of ammonia-free deproteinized latex medical surgical gloves, and particularly relates to an ammonia-free deproteinized latex medical surgical glove and a preparation method thereof, raw materials of which include, by weight, 1000 parts of 60wt% ammonia-free natural concentrated latex, 8-12 parts of a composite enzyme preparation, 0.1-0.3 parts of a p-hydroxyacetophenone-1,2-hexanediol compounded preservative system, 0.8-1.2 parts of a composite filler, 1.5-2.5 parts of o-naphthalic anhydride, 0.5-1.5 parts of stearic acid, 10-14 parts of t-butyl peroxybenzoate, 1.3-1.7 parts of a promoter TMTM, and 0.2-0.4 parts of an antioxidant 1010; the present application significantly improves the preservative stability and mechanical strength of the medical surgical glove by using the self-prepared composite enzyme preparation, composite filler and p-hydroxyacetophenone-1,2-hexanediol compounded preservative system, and simultaneously reduces the sensitization of the medical surgical glove.

Description

Technical Field

[0001] This invention relates to the field of ammonia-free deproteinized latex medical surgical glove preparation technology, and particularly to an ammonia-free deproteinized latex medical surgical glove and its preparation method. Background Technology

[0002] Medical surgical gloves are commonly used protective and hygiene equipment in medical settings. They effectively isolate medical staff's hands from patients' bodily fluids, secretions, blood, etc., to avoid cross-infection. At the same time, they prevent medical staff's hands from contaminating patients' wounds or mucous membranes, improving the comfort of operation. They are basic protective equipment to ensure the safety of both medical staff and patients and meet medical and hygiene standards. Currently, ammonia is commonly used as a stabilizer in medical surgical gloves. However, residual ammonia can volatilize and irritate the skin, mucous membranes, and respiratory tract of medical staff and patients. It can also accelerate the aging of latex. Furthermore, the water-soluble proteins contained in latex can easily trigger allergies. Medical staff and other high-frequency contacts have a high allergy rate, which can lead to shock in severe cases.

[0003] Therefore, it is crucial to develop an ammonia-free deproteinized latex medical surgical glove and its preparation method. Traditional ammonia-free designs and deproteinization techniques have failed to reduce the content of allergenic proteins in natural latex to a safe level. At the same time, the resulting ammonia-free deproteinized latex medical surgical gloves suffer from problems such as poor antiseptic stability, high allergenicity, and poor mechanical strength. Meanwhile, p-hydroxyacetophenone and 1,2-hexanediol can synergistically prevent spoilage, inhibit bacterial cell membrane synthesis, and destroy microbial cell walls, thus replacing ammonia as a preservative and becoming the core candidate raw materials for the preparation of a new generation of ammonia-free deproteinized latex medical surgical gloves. Summary of the Invention

[0004] This application provides an ammonia-free deproteinized latex medical surgical glove and its preparation method, thereby solving the problems of poor anti-corrosion stability, high allergenicity, and poor mechanical strength of ammonia-free deproteinized latex medical surgical gloves.

[0005] The first aspect of this application provides an ammonia-free deproteinized latex medical surgical glove, which is composed of ammonia-free natural concentrated latex, a compound enzyme preparation, a p-hydroxyacetophenone-1,2-hexanediol compound antiseptic system, and a compound filler.

[0006] Furthermore, the compound enzyme preparation is a mixture of metalloproteinase and glycosyl hydrolase at a mass ratio of 1:1, and the enzyme activity unit after mixing is 5000 U / g.

[0007] Furthermore, the p-hydroxyacetophenone-1,2-hexanediol compound preservative system is composed of p-hydroxyacetophenone and 1,2-hexanediol in a mass ratio of 1:1-1.2.

[0008] Furthermore, the composite filler is prepared by adding 0.5-1.0 parts of collagen nanofibers and 0.3-0.6 parts of chitin nanocrystals to 50-60 parts of deionized water, magnetically stirring at room temperature for 20 minutes, and then ultrasonically treating it at 200W power for 20 minutes in an ultrasonic cleaner.

[0009] The second aspect of this application provides a method for preparing an ammonia-free, deproteinized latex medical surgical glove, comprising the following steps: In a stainless steel reactor, 500 parts of deionized water were added to 1000 parts of 60wt% ammonia-free natural concentrated latex. The mixture was stirred and diluted to a total solids content of 40%. The stirring speed was 150 r / min, and the temperature was raised to 45℃. 8-12 parts of compound enzyme preparation were added, and the pH was adjusted to 7.0. The mixture was stirred for 6 hours, then heated to 80℃ and kept at that temperature for 30 minutes. The mixture was cooled to 30℃ and passed through a 300-mesh sieve to obtain deproteinized latex.

[0010] It is understood that, in this embodiment of the application, the total solids content is adjusted to 40% by controlling the ratio of deionized water to concentrated latex, thereby adapting the system fluidity and reaction efficiency of the enzymatic hydrolysis reaction. The metalloproteinases and glycosyl hydrolases in the compound enzyme preparation degrade the water-soluble allergenic proteins in the latex under the optimal temperature of 45°C and the optimal pH conditions, decomposing them into small molecule peptides or amino acids. The temperature is raised to 80°C and kept at 30 min to denature and inactivate the enzymes, avoiding the continuous action of the enzymes from damaging the latex structure. The incompletely degraded protein residues and impurities are removed by passing through a 300-mesh sieve, and finally, low-allergenic, high-purity deproteinized latex is obtained.

[0011] A multifunctional latex mixing vessel was used. 0.1-0.3 parts of a p-hydroxyacetophenone-1,2-hexanediol compound preservative system were added to the deproteinized latex and stirred for 20 min. Then, 0.8-1.2 parts of a composite filler were added sequentially and stirred for 30 min. Next, o-naphthalenedicarboxylic anhydride was added and stirred for 30 min. Then, stearic acid was added and stirred for 30 min. Finally, tert-butyl peroxide was added and stirred for 40 min. Then, accelerator TMTM was added and stirred for 20 min. Finally, antioxidant 1010 was added and stirred for 30 min. The mixture was then allowed to stand under vacuum for 4 h to remove bubbles, resulting in raw latex.

[0012] It is understood that the embodiments of this application use a compound preservative system of p-hydroxyacetophenone-1,2-hexanediol to disrupt the cell membrane of microorganisms, reduce water activity, and synergistically inhibit the growth of bacteria and fungi in latex, thus preventing deterioration. The composite filler is evenly dispersed in the latex matrix after stirring to fill the gaps between molecules and improve the tensile strength and tear resistance of the gloves. O-naphthalene dicarboxylic anhydride plasticizes the latex to improve its flexibility, stearic acid lubricates to optimize processing and demolding properties, tert-butyl peroxide and accelerator TMTM synergistically provide crosslinking activity for vulcanization, antioxidant 1010 captures free radicals to delay aging, and gravity is used during the standing process to allow air bubbles in the latex to rise and escape naturally, preventing the finished gloves from having pores that affect their protective and mechanical properties.

[0013] A PTFE-coated medical surgical glove mold was selected, and after deep cleaning, a 5μm thick layer of medical petroleum jelly was evenly applied and cooled to 40℃ to obtain a pretreated mold.

[0014] It is understood that the embodiments of this application remove impurities, residual latex and microorganisms from the mold surface through deep cleaning, avoiding contamination of the latex film and ensuring the sterility of the gloves. Furthermore, a 5μm thick layer of medical petroleum jelly is evenly applied to form a dense isolation film on the mold surface, reducing direct contact and adhesion between the raw latex and the mold, providing lubrication for glove demolding, and preventing the latex film from tearing during demolding. Cooling to 40°C allows the petroleum jelly to form a uniform coating, which avoids both high temperature causing the petroleum jelly to melt and flow away, and low temperature causing the petroleum jelly to solidify and clump, affecting the smoothness of the coating, and ensuring that the latex can form a uniform film on the mold surface.

[0015] The pretreated mold was immersed in a 10% calcium chloride solution for 5 minutes, dried at 100-120°C for 20 minutes, immersed in the raw rubber latex at a speed of 5 cm / s, held for 60 seconds, removed at the same speed, hung vertically to drain for 15 minutes, dried in a hot air oven at 80-100°C for 20 minutes, and then subjected to gradient vulcanization in a vulcanization tunnel. After vulcanization, the mold was cooled to 60°C and rinsed with deionized water three times for 2 minutes each time. The opening of the glove was rolled inward by 1.5 cm to form a sealed edge. The glove was then vacuum dried, packed into a sterile packaging bag, sterilized with ethylene oxide, and desorbed for 48-72 hours to obtain ammonia-free deproteinized latex medical surgical gloves.

[0016] Understandably, in this embodiment, the mold is immersed in a 10% calcium chloride solution. The calcium ions in the calcium chloride solution break down the double electric layer of the raw rubber latex, causing the latex particles to quickly solidify on the mold surface to form a preliminary film. The film shape is fixed by drying at 100°C. The latex film thickness is ensured by uniform immersion at a speed of 5 cm / s and a 60-second pause. Excess latex is removed by vertical draining. Gradient vulcanization causes the rubber molecules in the latex to cross-link and form a three-dimensional network structure by gradually increasing the temperature, which improves the elasticity and strength of the gloves. The surface is rinsed with deionized water to remove residual additives and impurities. Vacuum drying avoids high-temperature aging. Ethylene oxide sterilization kills microorganisms through alkylation reaction. Ethylene oxide residue is removed by 72 hours of analysis. The rolled edge design enhances the sealing performance and wearing comfort, ultimately ensuring that the gloves meet medical sterility standards.

[0017] Furthermore, in step (1), the pH is adjusted using a 10% citric acid solution.

[0018] Furthermore, in step (2), the amount of o-naphthalenecarboxylic anhydride added is 1.5-2.5 parts, the amount of stearic acid added is 0.5-1.5 parts, the amount of tert-butyl peroxide added is 10-14 parts, the amount of accelerator TMTM added is 1.3-1.7 parts, the amount of antioxidant 1010 added is 0.2-0.4 parts, the stirring speed is 200 r / min, the temperature is 30℃, the vacuum degree of vacuum standing degassing is -0.08 MPa, and the temperature is 25℃.

[0019] Furthermore, the deep cleaning process in step (3) involves first soaking in a 5% sodium hydroxide solution at 50°C for 20 minutes, rinsing with deionized water until neutral, immersing in a 75% ethanol solution for 3 minutes for disinfection, air drying, and then preheating in a 120°C oven for 15 minutes.

[0020] It is understood that, in this embodiment of the application, when performing deep cleaning of the polytetrafluoroethylene coated medical surgical glove mold, the mold is first soaked in a 5% sodium hydroxide solution at 50°C for 20 minutes. Sodium hydroxide, as a strong alkali, effectively removes residual grease, organic dirt, and impurities adhering to the mold surface during processing. The 50°C temperature enhances the activity of the alkali solution, strengthens its cleaning ability, and shortens the cleaning time. Subsequently, the mold is rinsed with deionized water until neutral, which thoroughly removes residual sodium hydroxide from the mold surface, preventing the strong alkali from affecting the stability of the medical petrolatum coating and preventing residual alkali from harming the glove material or the user during use. To prevent adverse effects, the mold is then immersed in a 75% ethanol solution for 3 minutes to disinfect it, thereby killing bacteria, viruses, and other microorganisms on the mold surface and ensuring that the mold meets medical-grade hygiene standards. After drying, the mold is placed in a 120℃ oven for 15 minutes to preheat it. This removes residual ethanol from the mold surface and prevents the ethanol from reacting with the applied medical petroleum jelly, which would affect the uniform application of the petroleum jelly. At the same time, preheating stabilizes the mold temperature, making it easier for the 5μm thick layer of medical petroleum jelly to adhere quickly and evenly. It also further removes trace amounts of moisture on the mold surface, ensuring the dryness of the pretreated mold and creating favorable conditions for glove molding.

[0021] Furthermore, the vacuum drying process in step (4) is to dry in a vacuum drying oven at 60°C and -0.08MPa for 3 hours.

[0022] It is understood that the embodiments of this application dry the gloves at 60°C and -0.08MPa for 3 hours in a vacuum drying oven. The 60°C temperature setting can effectively remove residual moisture on the surface and inside of the gloves, while avoiding damage to the physical properties of the latex gloves due to excessively high temperatures. At the same time, it forms a temperature connection with the previous process of cooling the mold to 60°C, reducing the impact of sudden temperature changes on product quality. The -0.08MPa vacuum environment can lower the boiling point of water, accelerate the evaporation efficiency of moisture, shorten the drying time, and avoid the problems of glove surface hardening or uneven local shrinkage caused by conventional hot air drying. The 3-hour drying time can ensure that the gloves are thoroughly dried, preventing residual moisture from breeding microorganisms or affecting the sterilization effect during aseptic packaging and ethylene oxide sterilization, while ensuring the stability of the gloves during storage and use.

[0023] Furthermore, the gradient vulcanization process in step (4) is to keep warm at 60°C for 5 minutes, raise the temperature to 100°C and keep warm for 10 minutes, raise the temperature to 135°C and keep warm for 25 minutes, with a heating rate of 10°C / min. The ethylene oxide sterilization process is to use ethylene oxide with a concentration of 600 mg / L, at a temperature of 50°C, for 6 hours of sterilization.

[0024] It is understood that the embodiments of this application use a gradient vulcanization process to allow latex molecules to gradually complete the cross-linking reaction at different temperature stages. The initial low temperature of 60°C ensures that the latex is heated evenly, avoiding structural inhomogeneity caused by rapid local curing. The temperature is raised to 100°C and kept at that temperature to promote the evaporation of moisture in the latex and initiate preliminary vulcanization, enhancing the basic morphological stability of the glove. The high temperature of 135°C deepens the degree of cross-linking, improves the mechanical properties of the glove, and ensures the stability of the product structure. The 600 mg / L ethylene oxide concentration ensures a highly effective killing effect on bacteria, viruses, spores, etc., meeting the requirements for medical sterility. The temperature of 50°C enhances the penetration and reactivity of ethylene oxide, while avoiding the impact of high temperature on the performance of the latex glove. The 6-hour sterilization time ensures that ethylene oxide fully acts on all parts of the glove for thorough sterilization, and the 48-72-hour desorption process effectively removes residual ethylene oxide, ensuring product safety.

[0025] The beneficial effects of this invention are as follows: 1. This invention utilizes a highly efficient preservative system precisely formulated from p-hydroxyacetophenone and 1,2-hexanediol in a 1:1 mass ratio. The phenolic hydroxyl structure of p-hydroxyacetophenone disrupts the integrity of microbial cell membranes and interferes with their energy metabolism. 1,2-hexanediol reduces the system's water activity and penetrates into the microorganisms, causing cytoplasmic leakage. The two components synergistically and significantly inhibit the growth of bacteria, fungi, and molds in latex during storage and processing, effectively preventing rancidity, deterioration, and abnormal viscosity caused by microbial contamination. Simultaneously, mechanical stirring ensures uniform dispersion of the preservative components in the latex, forming a stable and long-lasting protective network. In the mold pretreatment stage, a 5% sodium hydroxide solution is used to soak the mold at 50°C for 20 minutes. The high-temperature saponification and emulsification of the alkali thoroughly removes residual grease, vulcanizing agents, and organic impurities from the mold surface and kills most heat-resistant microorganisms. Subsequently, the mold is treated at 75°C... The gloves are sterilized for 3 minutes with a % ethanol solution. The ethanol further eliminates bacteria and fungal spores in the alkaline solution, reducing the risk of microbial contamination of the wet latex film by the mold. In the finished product processing stage, ethylene oxide with a concentration of 600 mg / L is sterilized at 50°C for 6 hours. At 50°C, ethylene oxide gas can fully penetrate into the glove material. Its alkylation groups undergo irreversible alkylation reactions with the thiol and carboxyl groups of microbial proteins and the amino groups in nucleic acids, completely destroying their physiological activity and thus achieving complete elimination of microorganisms. After sterilization, the product undergoes 72 hours of analysis to reduce the residual concentration of ethylene oxide molecules. Finally, a vacuum drying process at 60°C and -0.08 MPa is used to remove residual moisture inside the gloves, reducing the conditions for secondary microbial growth caused by humid environments during storage and transportation, thereby significantly improving the anti-corrosion stability of medical surgical gloves. 2. This invention, by adding a compound enzyme preparation, utilizes metalloproteinases to specifically hydrolyze the peptide bonds of sensitizing proteins in latex under optimal temperature and pH conditions. This, combined with glycosyl hydrolases, efficiently decomposes the glycosidic bonds of glycoprotein side chains, deeply degrading water-soluble allergens into non-sensitizing small peptide fragments or free amino acids. The system is then heated to 80°C and held for 30 minutes, causing denaturation and complete inactivation of the enzyme protein through high temperature. This terminates the enzymatic reaction while avoiding excessive degradation that could damage the latex molecular backbone. Filtering through a 300-mesh precision sieve effectively retains incompletely degraded protein aggregates and colloidal residues, significantly reducing the residual protein content in the final latex. Furthermore, the use of ammonia-free, naturally concentrated latex eliminates the impact of ammonia volatilization. To mitigate skin and mucous membrane irritation and respiratory hazards, the composite filler contains collagen nanofibers and chitin nanocrystals uniformly dispersed in the latex matrix, forming a dense three-dimensional network. This network physically encapsulates natural rubber proteins and prevents their dissolution, reducing contact with core allergens. Furthermore, chemical cross-linking inhibits latex oxidative degradation, reducing the generation of small molecule irritants. In the post-processing stage, deionized water is used for spraying and rinsing to thoroughly remove emulsifier residues, free ions, and small molecule byproducts adsorbed on the glove surface. After 6 hours of ethylene oxide sterilization and penetration, followed by 72 hours of analysis, the residual ethylene oxide concentration is reduced to a safe threshold. Finally, vacuum drying removes moisture, forming a dense finished product package, thereby significantly reducing the risk of allergies associated with latex gloves. 3. This invention, by adding composite fillers, forms a uniformly dispersed molecular-level reinforcing network in the latex matrix. The natural fibrous structure of collagen nanofibers intercalates with the latex molecular chains at multiple points, while chitin nanocrystals, in a rigid particle form, fill the gaps between rubber molecules, synergistically constructing a three-dimensional reinforcing skeleton. This effectively disperses localized stress on the glove under stress, preventing stress concentration-induced cracking. Furthermore, by enhancing the structural density of the latex film, it reduces the displacement space of molecular chains under external forces. Simultaneously, tert-butyl peroxide, as a highly efficient vulcanizing agent, gradually decomposes the peroxide bonds in its molecular structure under increasing temperature during gradient vulcanization, generating highly reactive free radicals. The free radicals attack the unsaturated double bonds on the natural rubber molecular chain, triggering a cross-linking reaction between molecules. The accelerator TMTM accelerates the generation rate of free radicals and lowers the activation energy of the cross-linking reaction, promoting the formation of a more regular and dense three-dimensional network structure of latex molecules. This significantly enhances the chemical bonding force between molecules and reduces the slippage of molecular chains during stretching. At the same time, o-naphthalenecarboxylic anhydride, as a plasticizer, can embed its anhydride groups between rubber molecular chains, increasing the intermolecular distance to improve flexibility. It also avoids material embrittlement caused by excessive cross-linking density. Together with the composite filler, it forms a synergistic effect of rigidity enhancement and flexibility regulation, thereby significantly improving the tensile strength of the glove. 4. This invention utilizes 0.5-1.0 parts of collagen nanofibers and 0.3-0.6 parts of chitin nanocrystals, through magnetic stirring and ultrasonic treatment, to break the aggregation tendency between nanoparticles using ultrasonic cavitation effect and mechanical shear force, forming a highly uniformly dispersed nanoscale composite filler suspension system. Its fibrous and crystalline heterostructures interweave within a latex matrix to construct a stable three-dimensional support network, bearing and dispersing external stress. When the glove is torn by external force, the crack tip extends to the nanofiller interface. The fibrous collagen nanofibers bear tensile stress through a bridging mechanism, while the rigid chitin nanocrystals effectively disperse stress energy by deflecting the crack path, significantly delaying the material's degradation. The process of tearing is mitigated by the addition of tert-butyl peroxide and accelerator TMTM in the formulation. During the gradient vulcanization process, uniform and dense CC double bonds and polysulfide bonds are generated between the natural rubber molecular chains, which greatly improves the bonding force and cross-linking density between molecular chains. This effectively reduces the tendency of molecular chain slippage and breakage during tearing. Furthermore, o-naphthalene dicarboxylic anhydride, as a plasticizer, precisely regulates the cross-linking network density. The benzene ring structure is embedded between the rubber molecular chains to increase the spacing, avoiding the increase in network brittleness caused by excessive cross-linking. It also forms a multiphase structure of rigid particles-flexible interface-elastic matrix with the composite filler, which synergistically optimizes the toughness of the material, thereby improving the tear resistance. 5. This invention utilizes a complex enzyme preparation, metalloproteinases and glycosyl hydrolases, to deeply degrade allergenic proteins in latex, significantly reducing residual proteins, lipids, and other substances that easily cause allergic reactions in humans. Using ammonia-free concentrated natural latex as raw material, it significantly reduces volatile ammonia irritation and potential skin hazards. Furthermore, the addition of stearic acid to the formula provides lubrication, making the latex film surface smoother and reducing frictional resistance during wear. Simultaneously, o-naphthalenedicarboxylic anhydride, as a plasticizer, enhances the glove's flexibility and extensibility, improves tensile strength and elongation at break, and reduces tightness and restriction during wear, making the gloves more comfortable. The gloves offer greater flexibility in movement. Furthermore, a 5μm thick layer of medical-grade petroleum jelly is evenly applied to the mold, effectively aiding demolding, improving production efficiency, and forming a lubricating layer on the inner surface of the gloves. This further reduces direct friction with the skin during wear, enhancing the skin-friendly experience. Simultaneously, the glove openings are rolled to prevent rough edges from directly contacting and scratching the skin, enhancing the overall durability and wearing comfort of the gloves. Repeated rinsing with deionized water thoroughly removes residual chemical additives and impurities from the glove surface, further improving the product's skin affinity and biosafety, resulting in a significant improvement in wearing comfort. Attached Figure Description

[0026] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1This is a process flow diagram of a method for preparing an ammonia-free deproteinized latex medical surgical glove according to an embodiment of this application; Figure 2 The diagram shows the o-naphthalic anhydride structure of a method for preparing an ammonia-free deproteinized latex medical surgical glove according to an embodiment of this application. Figure 3 The stearic acid structure diagram is shown in the embodiment of the present application for a method of preparing an ammonia-free deproteinized latex medical surgical glove. Figure 4 The diagram shows the structure of tert-butyl benzoate in a method for preparing an ammonia-free deproteinized latex medical surgical glove according to an embodiment of this application. Figure 5 The diagram shows the structure of antioxidant 1010 in a method for preparing an ammonia-free deproteinized latex medical surgical glove according to an embodiment of this application. Figure 6 This diagram illustrates the p-hydroxyacetophenone-1,2-hexanediol compound preservative system for a method of preparing an ammonia-free deproteinized latex medical surgical glove according to an embodiment of this application. Detailed Implementation

[0027] The technical solution of the present invention is illustrated below through specific examples. It should be understood that the one or more method steps mentioned in the present invention do not preclude the existence of other method steps before or after the combined steps, or the insertion of other method steps between these explicitly mentioned steps; it should also be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, unless otherwise stated, the numbering of each method step is merely a convenient tool for identifying each method step, and not for limiting the order of the method steps or defining the scope of the present invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the present invention.

[0028] To better understand the above technical solutions, exemplary embodiments of the present invention are described in more detail below. While exemplary embodiments of the present invention are shown, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the invention to those skilled in the art.

[0029] The metalloproteinases used in this application's embodiments are from Hangzhou Lianke Biotechnology Co., Ltd.; the glycosyl hydrolases are from Nanjing Camillo Bioengineering Co., Ltd.; the p-hydroxyacetophenone is from Jiangsu Xinhan New Materials Co., Ltd.; the 1,2-hexanediol is from Ningbo Chaoming Biotechnology Co., Ltd.; the collagen nanofibers are from Chengdu Kelejin Biotechnology Co., Ltd.; the chitin nanocrystals are from Shenzhen Qihong New Materials Co., Ltd.; the deionized water is from Shanghai Fantanxi Biochemical Technology Co., Ltd.; the ammonia-free natural concentrated latex is from Yunnan Senjie Medical Latex Equipment Co., Ltd.; and the o-naphthalenedicarboxylic anhydride is from Shanghai Maclean Biochemical Technology Co., Ltd. Limited Liability Company; the stearic acid used is from Hunan Ruhong Pharmaceutical Co., Ltd.; the tert-butyl benzoate used is from Jiangsu Jinghua Tiancheng New Material Technology Co., Ltd.; the accelerator TMTM used is from Shanghai Dingfen Chemical Technology Co., Ltd.; the antioxidant 1010 used is from Guangzhou Dayin New Material Co., Ltd.; the polytetrafluoroethylene coated medical surgical glove mold used is from Shanghai Dipping Industry Co., Ltd.; the medical petrolatum used is from Shanghai Yuejiang Titanium Dioxide Chemical Products Co., Ltd.; the calcium chloride used is from Nantong Badi Chemical Co., Ltd.; the ethylene oxide used is from Shanghai Maclean Biochemical Technology Co., Ltd.; and the ethanol used is from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0030] The following description, with reference to the accompanying drawings, describes an embodiment of an ammonia-free deproteinized latex medical surgical glove and its preparation method. Addressing the problems mentioned in the background art regarding the poor anti-corrosion stability and low mechanical strength of ammonia-free deproteinized latex medical surgical gloves, this application provides a method for preparing an ammonia-free deproteinized latex medical surgical glove: using ammonia-free natural concentrated latex as raw material, in the deproteinization stage, a compound enzyme preparation is used to specifically degrade sensitizing water-soluble proteins, breaking them down into small molecule peptides or amino acids to reduce protein residue and allergenicity. A composite filler is added and embedded into the latex matrix to form a reinforcing skeleton to improve tensile strength, constructing a three-dimensional support network to disperse tear stress. During gradient vulcanization, rubber molecules crosslink to form a three-dimensional network structure, enhancing intermolecular forces, improving tensile strength, and forming a uniform and dense crosslinked structure, reducing molecular chain breakage during tearing, thereby improving tear resistance. During gradient vulcanization, tert-butyl peroxide in its molecular structure... The highly reactive free radicals generated by the decomposition of peroxide bonds attack the unsaturated double bonds on the latex molecular chains, initiating cross-linking reactions between molecules. Simultaneously, the accelerator TMTM accelerates the free radical generation rate, promoting the formation of a denser three-dimensional network structure in the latex molecules. This significantly reduces molecular chain slippage during stretching, providing stable mechanical support for the glove. o-Naphthalenedicarboxylic anhydride regulates the cross-linking density, preventing excessive embrittlement during vulcanization to optimize tensile and tear resistance, and acts as a plasticizer to enhance glove flexibility and reduce tightness. Stearic acid smooths the latex film surface, further improving wearing comfort. Medical-grade petroleum jelly assists in mold release and forms an inner lubricating layer, reducing frictional resistance. Deionized water spraying removes residual additives and impurities, reducing potential allergens. A 1.5cm inward roll at the glove opening prevents edge scratches, further enhancing wearing comfort. This process solves the problems of poor anti-corrosion stability, high allergenicity, and poor mechanical strength in ammonia-free, deproteinized latex medical surgical gloves.

[0031] The following description, with reference to the accompanying drawings, illustrates an embodiment of an ammonia-free deproteinized latex medical surgical glove and its preparation method.

[0032] Specifically, Figure 1 This is a schematic flowchart illustrating an ammonia-free deproteinized latex medical surgical glove and its preparation method, provided in an embodiment of this application.

[0033] Specifically, the preparation method of this ammonia-free, deproteinized latex medical surgical glove includes the following steps: In step S101, in a stainless steel reactor, 500 parts of deionized water are added to 1000 parts of 60wt% ammonia-free natural concentrated latex, and the mixture is stirred and diluted to a total solid content of 40%. The stirring speed is 150 r / min, the temperature is raised to 45℃, 8-12 parts of compound enzyme preparation are added, the pH is adjusted to 7.0, the mixture is stirred for 6 hours, the temperature is raised to 80℃ and kept at that temperature for 30 minutes, the temperature is cooled to 30℃, and the mixture is passed through a 300-mesh sieve to obtain deproteinized latex.

[0034] Furthermore, the pH was adjusted using a 10% citric acid solution.

[0035] It is understood that, in this embodiment of the application, the total solids content is precisely adjusted to 40% by controlling the ratio of deionized water to concentrated latex, thereby adapting to the system fluidity and reaction efficiency of the enzymatic hydrolysis reaction. The metalloproteinases and glycosyl hydrolases in the compound enzyme preparation specifically degrade the water-soluble allergenic proteins in the latex under the optimal enzyme activity temperature of 45°C and the optimal pH conditions, decomposing them into small molecule peptides or amino acids. The temperature is raised to 80°C and kept at 30 min to denature and inactivate the enzymes, avoiding the continuous action of the enzymes from damaging the latex structure. The incompletely degraded protein residues and impurities are removed by passing through a 300-mesh sieve, and finally, a low-allergenic, high-purity deproteinized latex is obtained.

[0036] Specifically, in a stainless steel reactor, 500 parts of deionized water are added to 1000 parts of 60wt% ammonia-free natural concentrated latex. The mixture is stirred at 150 r / min to dilute the latex to a total solids content of 40%. The system is then heated to 45°C, and 8-12 parts of a compound enzyme preparation are added to adjust the pH to 7.0. The mixture is stirred continuously for 6 hours, then heated to 80°C and kept at that temperature for 30 minutes. Finally, the mixture is cooled to 30°C and filtered through a 300-mesh sieve to obtain deproteinized latex.

[0037] In step S102, a multi-functional latex mixing vessel is selected. 0.1-0.3 parts of a p-hydroxyacetophenone-1,2-hexanediol compound preservative system are added to the deproteinized latex and stirred for 20 minutes. Then, 0.8-1.2 parts of composite filler are added sequentially and stirred for 30 minutes. Next, o-naphthalenedicarboxylic anhydride is added and stirred for 30 minutes. Then, stearic acid is added and stirred for 30 minutes. Finally, tert-butyl peroxide is added and stirred for 40 minutes. Then, accelerator TMTM is added and stirred for 20 minutes. Finally, antioxidant 1010 is added and stirred for 30 minutes. The mixture is then allowed to stand under vacuum for 4 hours to remove bubbles, thus obtaining raw latex.

[0038] Furthermore, the amount of o-naphthalenecarboxylic anhydride added is 1.5-2.5 parts, the amount of stearic acid added is 0.5-1.5 parts, the amount of tert-butyl peroxide added is 10-14 parts, the amount of accelerator TMTM added is 1.3-1.7 parts, the amount of antioxidant 1010 added is 0.2-0.4 parts, the stirring speed is 200 r / min, the temperature is 30℃, the vacuum degree of vacuum standing degassing is -0.08MPa, and the temperature is 25℃.

[0039] It is understood that the embodiments of this application use a compound preservative system of p-hydroxyacetophenone-1,2-hexanediol to disrupt the cell membrane of microorganisms, reduce water activity, and synergistically inhibit the growth of bacteria and fungi in latex. The composite filler is evenly dispersed in the latex matrix after stirring to fill the gaps between molecules and improve the tensile strength and tear resistance of the gloves. O-naphthalene dicarboxylic anhydride plasticizes the latex to improve its flexibility. Stearic acid lubricates and optimizes processing and demolding properties. Tert-butyl peroxide and accelerator TMTM work together to reserve crosslinking activity for vulcanization. Antioxidant 1010 captures free radicals and delays aging. During the static process, gravity is used to allow air bubbles in the latex to float to the surface and escape naturally, avoiding the formation of pores in the finished gloves that affect their protective and mechanical properties.

[0040] Specifically, a multi-functional latex mixing vessel was used. 0.1-0.3 parts of a p-hydroxyacetophenone-1,2-hexanediol compound preservative system were added to the deproteinized latex and stirred for 20 minutes. Then, 0.8-1.2 parts of a composite filler were added sequentially and stirred for 30 minutes. Next, o-naphthalenedicarboxylic anhydride was added and stirred for 30 minutes. Then, stearic acid was added and stirred for 30 minutes. After that, tert-butyl peroxide was added and stirred for 40 minutes. Then, accelerator TMTM was added and stirred for 20 minutes. Finally, antioxidant 1010 was added and stirred for 30 minutes. After stirring, the mixture was allowed to stand for degassing for 4 hours to obtain raw latex.

[0041] In step S103, a polytetrafluoroethylene coated medical surgical glove mold is selected. After deep cleaning, a layer of medical petroleum jelly with a thickness of 5 μm is evenly applied and cooled to 40°C to obtain a pre-treated mold.

[0042] Furthermore, the deep cleaning process involves first soaking in a 5% sodium hydroxide solution at 50°C for 20 minutes, rinsing with deionized water until neutral, immersing in a 75% ethanol solution for disinfection for 3 minutes, air drying, and then preheating in a 120°C oven for 15 minutes.

[0043] It is understood that the embodiments of this application remove impurities, residual latex and microorganisms from the mold surface through deep cleaning to avoid contaminating the latex film and ensure the sterility of the gloves. A 5μm thick layer of medical petroleum jelly is evenly applied to form a dense isolation film on the mold surface, reducing the direct contact and adhesion between the raw latex and the mold, providing lubrication for glove demolding, and preventing the latex film from tearing during demolding. Cooling to 40°C allows the petroleum jelly to form a stable and uniform coating, which avoids the petroleum jelly melting and flowing due to high temperature, and also prevents the petroleum jelly from solidifying and clumping due to low temperature, affecting the smoothness of the coating, and ensuring that the latex forms a uniform film on the mold surface.

[0044] Specifically, a medical surgical glove mold with a polytetrafluoroethylene coating is selected, and the mold is thoroughly cleaned. After cleaning, a 5μm thick layer of medical petroleum jelly is evenly applied to the surface of the mold. After the medical petroleum jelly is evenly applied, the mold is cooled to 40°C to allow the petroleum jelly to form a stable and uniform coating on the surface of the mold, thus obtaining the pre-treated mold.

[0045] In step S104, the pretreated mold is immersed in a 10% calcium chloride solution for 5 minutes, dried at 100-120℃ for 20 minutes, immersed in raw rubber latex at a speed of 5 cm / s for 60 seconds, removed at the same speed, hung vertically to drain for 15 minutes, dried in a hot air oven at 80-100℃ for 20 minutes, and then vulcanized in a gradient in a vulcanization tunnel. After vulcanization, the mold is cooled to 60℃, rinsed with deionized water three times for 2 minutes each time, and the opening of the glove is rolled inward by 1.5 cm to form a sealed edge. The glove is then vacuum dried, packed into a sterile packaging bag, sterilized with ethylene oxide, and desorbed for 48-72 hours to obtain ammonia-free deproteinized latex medical surgical gloves.

[0046] Furthermore, the vacuum drying process involves drying at 60°C and -0.08 MPa for 3 hours in a vacuum drying oven; the gradient vulcanization process involves holding at 60°C for 5 minutes, raising the temperature to 100°C and holding for 10 minutes, raising the temperature to 135°C and holding for 25 minutes, with a heating rate of 10°C / min; and the ethylene oxide sterilization process involves sterilizing with 600 mg / L ethylene oxide at 50°C for 6 hours.

[0047] Understandably, in this embodiment, the mold is immersed in a 10% calcium chloride solution. The calcium ions in the calcium chloride solution break down the double electric layer of the raw rubber latex, causing the latex particles to quickly solidify on the mold surface to form a preliminary film. The film shape is fixed by drying at 100°C. The latex film thickness is ensured by uniform immersion at a speed of 5 cm / s and a 60-second pause. Excess latex is removed by vertical draining. Gradient vulcanization causes the rubber molecules in the latex to cross-link and form a three-dimensional network structure by gradually increasing the temperature, which improves the elasticity and strength of the gloves. The surface is rinsed with deionized water to remove residual additives and impurities. Vacuum drying avoids high-temperature aging. Ethylene oxide sterilization kills microorganisms through alkylation reaction. Ethylene oxide residue is removed by 72 hours of analysis. The rolled edge design enhances the sealing performance and wearing comfort, ultimately ensuring that the gloves meet medical sterility standards.

[0048] Specifically, the pre-treated mold is immersed in a 10% calcium chloride solution for 5 minutes, then dried at 100°C for 20 minutes. The mold is then immersed in raw rubber latex at a speed of 5 cm / s, held for 60 seconds, and then removed at the same speed. It is then hung vertically to drain for 15 minutes, followed by drying in an 80°C hot air oven for 20 minutes. Gradient vulcanization is then carried out in a vulcanization tunnel. After vulcanization, the mold is cooled to 60°C and rinsed three times with deionized water for 2 minutes each time. The opening of the glove is then rolled inward by 1.5 cm to form a sealed edge, and vacuum dried. After drying, it is packed into a sterile packaging bag and sterilized with ethylene oxide. After sterilization, it is analyzed for 72 hours to finally obtain ammonia-free deproteinized latex medical surgical gloves.

[0049] This application provides a method for preparing ammonia-free deproteinized latex medical surgical gloves: using ammonia-free natural concentrated latex as raw material, in the deproteinization stage, a compound enzyme preparation is used to specifically degrade sensitizing water-soluble proteins, breaking them down into small molecule peptides or amino acids to reduce protein residue and allergenicity. A compound filler is added and embedded in the latex matrix to form a reinforcing skeleton to improve tensile strength, constructing a three-dimensional support network to disperse tear stress. During gradient vulcanization, rubber molecules crosslink to form a three-dimensional network structure, enhancing intermolecular forces, improving tensile strength, and forming a uniform and dense crosslinked structure, reducing molecular chain breakage during tearing, thereby improving tear resistance. During gradient vulcanization, tert-butyl peroxide, through the decomposition of peroxide bonds in its molecular structure, generates highly reactive free radicals that attack the latex molecules. The unsaturated double bonds on the sub-chains initiate cross-linking reactions between molecules. Simultaneously, the accelerator TMTM accelerates the free radical generation rate, driving the latex molecules to form a denser three-dimensional network structure. This significantly reduces chain slippage during stretching, providing stable mechanical support for the glove. o-Naphthalenedicarboxylic anhydride regulates the cross-linking density, preventing excessive vulcanization and embrittlement, thus optimizing tensile and tear resistance. It also acts as a plasticizer to enhance glove flexibility and reduce tightness. Stearic acid smooths the latex film surface, further improving wearing comfort. Medical-grade petroleum jelly assists in mold release and forms an inner lubricating layer, reducing frictional resistance. Deionized water spraying removes residual additives and impurities, reducing potential allergens. A 1.5cm inward roll at the glove opening prevents edge scratches, further enhancing wearing comfort. This solution addresses the problems of poor anti-corrosion stability, high allergenicity, and poor mechanical strength in ammonia-free, deproteinized latex medical surgical gloves.

[0050] The following will describe a method for preparing an ammonia-free, deproteinized latex medical surgical glove according to this application through specific embodiments, including:

[0051] Example 1 This application proposes an ammonia-free deproteinized latex medical surgical glove, which is composed of ammonia-free natural concentrated latex, a compound enzyme preparation, a p-hydroxyacetophenone-1,2-hexanediol compound antiseptic system, and a compound filler.

[0052] Furthermore, the compound enzyme preparation is a mixture of metalloproteinase and glycosyl hydrolase at a mass ratio of 1:1, and the enzyme activity unit after mixing is 5000U / g.

[0053] Furthermore, the p-hydroxyacetophenone-1,2-hexanediol compound preservative system is composed of p-hydroxyacetophenone and 1,2-hexanediol in a mass ratio of 1:1.

[0054] Furthermore, the composite filler is prepared by adding 0.5 parts of collagen nanofibers and 0.3 parts of chitin nanocrystals to 50 parts of deionized water, stirring magnetically for 20 minutes at room temperature, and then ultrasonically treating it for 20 minutes at 200W power in an ultrasonic cleaner.

[0055] This application also proposes a method for preparing ammonia-free, deproteinized latex medical surgical glove, comprising the following steps: (1) In a stainless steel reactor, 500 parts of deionized water were added to 1000 parts of 60wt% ammonia-free natural concentrated latex, and the mixture was stirred and diluted to a total solid content of 40%. The stirring speed was 150r / min, the temperature was raised to 45℃, 8 parts of compound enzyme preparation were added, the pH was adjusted to 7.0, the mixture was stirred for 6h, the temperature was raised to 80℃ and kept warm for 30min, the temperature was cooled to 30℃, and the mixture was passed through a 300-mesh sieve to obtain deproteinized latex. (2) Using a multi-functional latex mixing vessel, add 0.1 parts of a p-hydroxyacetophenone-1,2-hexanediol compound preservative system to the deproteinized latex, stir for 20 min, then add 0.8 parts of composite filler, stir for 30 min, and then add o-naphthalenedicarboxylic anhydride, such as... Figure 2 As shown, stir for 30 minutes, then add stearic acid, as follows: Figure 3 As shown, stir for 30 minutes, then add tert-butyl peroxide, as follows. Figure 4 As shown, stir for 40 minutes, then add the accelerator TMTM, stir for 20 minutes, and finally add the antioxidant 1010. Figure 5 As shown, stir for 30 minutes, then allow to stand under vacuum for 4 hours to remove bubbles, to obtain raw rubber latex; (3) Select a medical surgical glove mold with polytetrafluoroethylene coating, and after deep cleaning, evenly coat it with a layer of medical petroleum jelly with a thickness of 5μm, and cool it to 40℃ to obtain a pre-treated mold. (4) Immerse the pretreated mold in 10% calcium chloride solution for 5 min, dry at 100℃ for 20 min, immerse it in raw rubber latex at a speed of 5 cm / s, stay for 60 seconds, take it out at the same speed, hang it vertically to drain for 15 min, dry it in an 80℃ hot air oven for 20 min, and then perform gradient vulcanization in a vulcanization tunnel. After vulcanization, cool the mold to 60℃, rinse it with deionized water spray 3 times, 2 min each time, roll the opening of the glove inward by 1.5 cm to form a sealed rolled edge, vacuum dry it, pack it into a sterile packaging bag, sterilize it with ethylene oxide, and desorb it for 48 h to obtain ammonia-free deproteinized latex medical surgical gloves.

[0056] Furthermore, in step (1), the pH is adjusted using a 10% citric acid solution.

[0057] Further, in step (2), the amount of o-naphthalene dicarboxylic anhydride added is 1.5 parts, the amount of stearic acid added is 0.5 parts, the amount of tert-butyl peroxide added is 10 parts, the amount of accelerator TMTM added is 1.3 parts, the amount of antioxidant 1010 added is 0.2 parts, the stirring speed is 200 r / min, the temperature is 30℃, the vacuum degree of vacuum standing degassing is -0.08 MPa, and the temperature is 25℃.

[0058] Furthermore, the deep cleaning process in step (3) involves first soaking in a 5% sodium hydroxide solution at 50°C for 20 minutes, rinsing with deionized water until neutral, immersing in a 75% ethanol solution for 3 minutes for disinfection, air drying, and then preheating in a 120°C oven for 15 minutes.

[0059] Furthermore, step (4) involves vacuum drying at 60°C and -0.08 MPa for 3 hours in a vacuum drying oven.

[0060] Furthermore, in step (4), the gradient vulcanization process is to keep the temperature at 60℃ for 5 minutes, raise the temperature to 100℃ and keep it for 10 minutes, raise the temperature to 135℃ and keep it for 25 minutes, with a heating rate of 10℃ / min. The ethylene oxide sterilization process is to use ethylene oxide with a concentration of 600mg / L at a temperature of 50℃ for 6 hours.

[0061] Example 2 The difference between Example 2 and Example 1 is that the p-hydroxyacetophenone-1,2-hexanediol compound preservative system is composed of p-hydroxyacetophenone and 1,2-hexanediol in a mass ratio of 1:1.2. The rest is the same as in Example 1 and will not be repeated.

[0062] Example 3 The difference between Example 3 and Example 1 is that the composite filler is prepared by adding 1.0 part of collagen nanofibers and 0.6 parts of chitin nanocrystals to 60 parts of deionized water, stirring magnetically for 20 minutes at room temperature, and then ultrasonically treating it for 20 minutes at 200W power in an ultrasonic cleaner. The rest is the same as in Example 1 and will not be repeated.

[0063] Example 4 The difference between Example 4 and Example 1 is that the amount of compound enzyme preparation added is increased from 8 parts to 12 parts. The rest is the same as in Example 1 and will not be repeated.

[0064] Example 5 The difference between Example 5 and Example 1 is that the amount of composite filler added is increased from 0.8 parts to 1.2 parts. The rest is the same as in Example 1 and will not be repeated.

[0065] Example 6 The difference between Example 6 and Example 1 lies in the use of a p-hydroxyacetophenone-1,2-hexanediol compound preservative system, such as... Figure 6 As shown, the amount added was increased from 0.1 parts to 0.3 parts, and the rest was the same as in Example 1, so it will not be repeated here.

[0066] Example 7 The difference between Example 7 and Example 1 is that the amount of o-naphthalenecarboxylic anhydride added is 2.5 parts, the amount of stearic acid added is 1.5 parts, the amount of tert-butyl peroxide added is 14 parts, the amount of accelerator TMTM added is 1.7 parts, and the amount of antioxidant 1010 added is 0.4 parts. The rest is the same as in Example 1 and will not be repeated.

[0067] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that no composite filler was added to the raw rubber latex. Otherwise, they are the same as in Example 1 and will not be repeated.

[0068] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the vulcanization process was replaced with constant temperature vulcanization. The mold dried in an 80°C hot air oven was directly placed in a 135°C vulcanization tunnel for constant temperature vulcanization for 40 minutes. The rest is the same as in Example 1 and will not be repeated here.

[0069] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that the deproteinized latex preparation process did not use a complex enzyme for enzymatic hydrolysis, but a single enzyme was used. In a stainless steel reactor, 500 parts of deionized water were added to 1000 parts of 60wt% ammonia-free natural concentrated latex, and the mixture was stirred and diluted to a total solids content of 40%. The stirring speed was 150 r / min, the temperature was raised to 45°C, 8-12 parts of metalloproteinase were added, the pH was adjusted to 7.0, the mixture was stirred for 6 hours, the temperature was raised to 80°C and kept at that temperature for 30 minutes, the temperature was cooled to 30°C, and the mixture was passed through a 300-mesh sieve to obtain the deproteinized latex. Other steps were the same as in Example 1 and will not be repeated here.

[0070] Performance testing 1. Tensile strength test Testing equipment: Electronic universal testing machine.

[0071] Test Step 1: Take samples from three different areas of each batch of ammonia-free deproteinized latex medical surgical gloves: the middle of the palm, the base of the fingers, and the wrist. Cut the samples into dumbbell-shaped specimens that conform to the GB / T528-2009 standard. Prepare 5 specimens for each area. Ensure that the specimens are free of bubbles, cracks, and impurities. Measure the thickness at three points in the middle and at both ends of the specimen using a thickness gauge and take the average value, accurate to 0.01 mm.

[0072] Test Step 2: Set the clamping distance of the electronic universal testing machine to 25mm, adjust the tensile speed to 500mm / min, preheat the machine for 30 minutes, and calibrate the force and displacement sensors after the equipment parameters have stabilized.

[0073] Test Step 3: Fix both ends of the dumbbell-shaped specimen in the upper and lower clamps of the testing machine, respectively, and ensure that the specimen axis coincides with the center line of the clamps to avoid specimen tilting or uneven force.

[0074] Test Step 4: Start the testing machine and begin the tensile test. Record the force and displacement data in real time until the specimen breaks. Record the maximum tensile force and corresponding elongation at the time of breakage. If the specimen breaks at the clamping point, the data is invalid and the test is repeated.

[0075] Test Step 5: After the 5 valid samples in each region have been tested, calculate the tensile strength. Tensile strength = maximum tensile force / original cross-sectional area of ​​the sample, in MPa, and elongation at break. Take the average value of each region as the tensile strength result of that region. Finally, take the average tensile strength of the three regions as the overall tensile strength index of the glove.

[0076] Test Step Six: After the test, clean the remaining sample from the clamp, turn off the equipment, organize the test data and generate a report.

[0077] 2. Tear resistance test Testing equipment: electronic universal testing machine, right-angle cutter, thickness gauge.

[0078] Test Step 1: Samples were taken from three key areas of each batch of ammonia-free deproteinized latex medical surgical gloves: the palm, the base of the thumb, and the wrist. The samples were cut into right-angle tear test specimens using a right-angle cutter. Five specimens were prepared for each area, ensuring that the edges of the specimens were smooth and burr-free, and the pre-made tear depth was 10 mm. The thickness of the specimens was measured at three points in the tear area using a thickness gauge, and the average value was taken, accurate to 0.01 mm.

[0079] Test Step 2: Adjust the clamping distance of the electronic universal testing machine to 50mm, set the test speed to 500mm / min, preheat for 30 minutes, calibrate the force sensor, and then enter the test mode.

[0080] Test Step 3: Fix both ends of the specimen in the upper and lower clamps of the testing machine, so that the right-angled side of the specimen is consistent with the tensile direction, and the pre-made tear is located in the middle of the two clamps, ensuring that the force direction of the specimen is consistent with the tear extension direction.

[0081] Test Step 4: Start the testing machine to perform a tear test and record the maximum tear force value in real time until the sample is completely torn. If the tear path deviates from the pre-formed direction, the data is invalid and the test must be repeated.

[0082] Test Step 5: After the 5 valid samples for each part are tested, the tear strength = maximum tear force / sample thickness, unit: kN / m. The average value of the result for each part is taken, and the average tear strength of the three parts is finally used as the tear resistance performance index of the glove.

[0083] Test Step Six: After the test, clean the remaining sample from the clamp, save the test data, and generate a test report.

[0084] 3. Corrosion resistance stability test Testing equipment: constant temperature and humidity test chamber, electronic universal testing machine, thickness gauge, standard corrosive medium container, dumbbell-shaped cutter.

[0085] Test Step 1: Take samples from three key areas of each batch of ammonia-free deproteinized latex medical surgical gloves: the palm, the base of the thumb, and the wrist. Cut them into standard tensile specimens using a dumbbell-shaped cutter. Prepare 5 specimens for each area, ensuring that the specimen edges are smooth and free of burrs, bubbles, cracks, or other defects. Use a thickness gauge to measure the thickness at 3 points in the middle of the specimen, take the average value, accurate to 0.01 mm, and record the initial thickness data.

[0086] Test Step 2: Prepare two test media: 3% sodium hypochlorite solution and 0.9% physiological saline. Pour them into standard corrosive medium containers respectively. Set the temperature of the constant temperature and humidity test chamber to 37℃ and the humidity to 65%RH. Preheat the chamber for 60 minutes to ensure stable environmental parameters.

[0087] Test Step 3: Completely immerse 3 samples from each part in the two corrosive media, and use the remaining 2 as a blank control group. Place them in a constant temperature and humidity environment, put the container of corrosive media containing the samples into a constant temperature and humidity test chamber, and soak for 24 hours. During this period, observe and record the changes in the appearance of the samples every 8 hours, including discoloration, swelling, cracking, etc.

[0088] Test Step 4: After soaking, remove the corrosion group sample, rinse the surface residual medium with deionized water, absorb the water and let it stand for 30 minutes. Adjust the clamping distance of the electronic universal testing machine to 50 mm, set the test speed to 500 mm / min, calibrate the force sensor, and perform tensile tests on the corrosion group and blank group samples respectively. Record the tensile strength and elongation at break. If the fracture position of the sample deviates from the effective area, the data is invalid and the test needs to be repeated.

[0089] Test Step 5: After the effective sample test of each part is completed, calculate the relevant indicators of corrosion resistance stability: tensile strength retention rate = (tensile strength after corrosion / tensile strength of blank group) × 100%, elongation at break retention rate = (elongation at break after corrosion / elongation at break of blank group) × 100%, take the average value of each part, and finally use the average retention rate of the three parts as the corrosion resistance stability index of the glove.

[0090] Test Step Six: After the test, clean the constant temperature and humidity test chamber and the corrosive medium container, wipe the clamps of the electronic universal testing machine, save all test data, and generate a corrosion resistance stability test report.

[0091] 4. Allergenization test Testing equipment: fully automatic Kjeldahl nitrogen analyzer, analytical balance, constant temperature water bath, centrifuge, rabbit skin irritation test workbench, medical absorbent cotton, sterile physiological saline, vernier caliper, digital microscope.

[0092] Test Step 1: From 10 batches of ammonia-free deproteinized latex medical surgical gloves, randomly select 5 complete gloves from each batch, remove the rolled edges and the outer 1cm edge of the glove opening, leaving only the palm, the base of the fingers, and the wrist as the three key usage areas. Use a sterile sampling knife to cut each area into a uniform 1cm×1cm sample, and take 8 samples from each area. 5 samples are used for protein residue detection and 5 samples are used for skin irritation detection. Ensure that the samples are undamaged and free of stains, and place them in sterile petri dishes for later use.

[0093] Test Step 2: Place 5 samples into 50mL centrifuge tubes, add 20mL of sterile physiological saline, and extract by shaking in a 40℃ constant temperature water bath for 2h. Then centrifuge at 8000r / min for 15min, and take the supernatant as the protein extraction solution for testing. Soak 5 samples in sterile physiological saline for 30min to simulate the environment of gloves in contact with sweat, drain the surface water, and keep them moist for testing.

[0094] Test Step 3: Take 5 mL of protein extract and inject it into the digestion tube of the Kjeldahl nitrogen analyzer. Add 5 mL of concentrated sulfuric acid and 2 g of catalyst (copper sulfate: potassium sulfate = 1:10). Digest at 420℃ until the solution turns transparent blue-green. After cooling, bring the volume to 100 mL. Use the distillation module of the Kjeldahl nitrogen analyzer to add 40% sodium hydroxide solution for distillation. Absorb ammonia with 2% boric acid solution and then titrate with 0.01 mol / L hydrochloric acid standard solution. Record the volume of hydrochloric acid consumed and calculate the protein residue: Protein residue (μg / g) = (hydrochloric acid concentration × volume consumed × 14 × 6.25 × volume brought to a final volume) / (sample mass × extract volume), where 14 is the molar mass of nitrogen and 6.25 is the latex protein nitrogen conversion factor.

[0095] Test Step Four: Select 50 healthy New Zealand white rabbits, weighing between 2.0-2.5 kg, ensuring that all rabbits have no skin damage, inflammation, or history of skin sensitivity. Randomly divide them into 10 test groups, corresponding to 10 samples to be tested (Examples 1-7, Comparative Examples 1-3). Each group contains 5 rabbits, meaning each sample corresponds to 5 replicate test animals, meeting the requirements of GB / T16886.10-2017 for repeated testing of multiple animals to reduce individual differences. Each rabbit is numbered. 24 hours before the test, use a sterile razor to shave the hair on both sides of the back of each rabbit, with each shaved area defined as 3 cm. A 3cm × 3cm square was used to ensure that the shaving process did not damage the stratum corneum of the skin. The left area was marked as the test area and the right area as the control area. A sterile marker was used to make a light mark on the edge of the shaved area to avoid displacement during subsequent application. For each test group, one sample was prepared. A pretreated moistened sample of the sample was taken, 1cm × 1cm. It was ensured that the sample of each rabbit came from the same batch of samples and the same homogeneous material mixed from the same sampling area. A total of 5 samples were prepared, corresponding to 5 rabbits in the group. At the same time, sterile absorbent cotton of the same size was prepared, moistened with sterile physiological saline and squeezed to remove excess water, as a control. 5 samples were also prepared for each group.

[0096] Test Step 5: Fix each rabbit to a dedicated animal testing table. Take one moist sample of the corresponding specimen and apply it flat to the left side of the rabbit's back, ensuring that the specimen completely covers the test area without wrinkles. Take one control specimen and apply it to the right side of the control area. Then, use sterile medical breathable tape to fix it along the edge of the specimen / control specimen, avoiding direct contact between the tape and the skin of the test area. At the same time, ensure that the application is firm. After fixing, observe for 5 minutes. After confirming that there is no specimen displacement or falling off, put the rabbit back into a separate cage. Maintain a constant temperature of 25℃ and humidity of 50%RH in the breeding environment. During this period, the rabbits are prohibited from scratching the test area on their backs.

[0097] Test Step Six: After 4 hours of application, remove the sample and absorbent cotton, wipe the skin surface with sterile saline, and observe and record the skin reaction of the test area and control area at 1 hour, 24 hours, 48 ​​hours and 72 hours after removal. Score according to GB / T16886.10-2017 standard.

[0098] Step 7: Organize all test data, including protein residue and stimulation score, and generate an allergenicity test report.

[0099] The following are the mechanical property test results of Examples 1-7 and Comparative Examples 1-3, as shown in Table 1:

[0100] As shown in Table 1, in Example 2, the increased proportion of 1,2-hexanediol in the compound anticorrosive system enhanced the stability of the anticorrosive components and reduced the erosion of the latex by corrosive media. The retention rates of tensile strength and elongation at break slightly increased, while the cross-linking structure of the latex remained unchanged, and the tensile strength, elongation at break, and tear strength remained basically stable. In Examples 3 and 5, by increasing the amount of composite filler, nano-sized collagen nanofibers and chitin nanocrystals formed more mechanical support points in the latex, effectively hindering crack propagation and significantly improving tensile strength and tear strength. However, excessive filler slightly restricted the movement of latex molecular chains. The movement of the filler caused a slight decrease in elongation at break, but the filler and latex matrix were stably bonded, and the resistance to media was not affected, with the strength retention rate remaining basically unchanged. In Example 4, due to the increased amount of compound enzyme preparation, the latex was deproteinized more thoroughly, reducing the mechanical defects caused by protein residue, resulting in a slight increase in tensile strength, elongation at break, and tear strength. The optimized degree of deproteinization did not affect the resistance to media, and the strength retention rate was minimally affected. In Example 6, due to the increased amount of compound anticorrosive system, a denser protective layer was formed on the latex surface, enhancing the ability to resist media erosion and significantly increasing the strength retention rate. However, the excessive anticorrosive components slightly reduced the molecular weight of the latex. The increased use of plasticizer o-naphthalene dicarboxylic anhydride and softener stearic acid in Example 7 improved the flexibility of the latex molecular chain, resulting in a significant increase in elongation at break. However, the excessive additives diluted the crosslinking density of the latex, leading to a slight decrease in tensile strength and tear strength. Furthermore, the additives did not enhance resistance to media, and the strength retention rate decreased slightly. In Comparative Example 1, the lack of composite fillers and the absence of mechanical support from nanoparticles significantly reduced the tensile strength and tear strength of the latex. The absence of fillers increased the flexibility of the molecular chain, resulting in stable tensile strength and tear strength. The elongation at break increased slightly, and the unfilled latex was easily penetrated by the medium, resulting in a decrease in strength retention. In Comparative Example 2, the use of constant temperature vulcanization instead of gradient vulcanization and the lack of low-temperature preheating led to uneven cross-linking inside the latex, resulting in local stress concentration, which reduced tensile strength, elongation at break, and tear strength. Furthermore, the weak cross-linking areas were easily penetrated by the medium, further reducing the strength retention. In Comparative Example 3, the use of a single metalloproteinase instead of a complex enzyme resulted in incomplete deproteinization, leaving residual sugars and other impurities that formed mechanical defects. This led to a slight decrease in tensile strength, elongation at break, and tear strength, and the impurities were more likely to react with the medium, further reducing the strength retention.

[0101] The following are the sensitization test results for Examples 1-7 and Comparative Examples 1-3, as shown in Table 2:

[0102] As shown in Table 2, Example 1, as the baseline group, used a 1:1 ratio of compound enzyme to synergistically hydrolyze the peptide bonds and glycoprotein glycosidic bonds in the latex, achieving thorough deproteinization. Combined with the composite filler, it provided adsorption and lubrication assistance, resulting in low levels of protein residue and irritation scores. In Example 2, the ratio of p-hydroxyacetophenone-1,2-hexanediol was adjusted to 1:1.2. The high proportion of 1,2-hexanediol increased latex viscosity, leading to decreased enzyme dispersion uniformity and a slight decrease in protein degradation efficiency. Furthermore, the alcohol caused a slight permeation irritation to the skin, resulting in a slight increase in protein residue and irritation scores compared to Example 1. In Example 3, the increased amount of collagen nanofibers and chitin nanocrystals in the preparation of the composite filler resulted in a stronger physical adsorption effect, allowing for the adsorption of more... After multi-enzyme hydrolysis, small molecule sensitizers remained, and the biocompatible filler further reduced skin irritation. Therefore, protein residue and irritation score decreased compared to Example 1. In Example 4, due to a significant increase in the amount of compound enzyme, more enzyme molecules bound to the sensitizing protein to achieve a deeper degradation reaction, completely decomposing the large protein molecules into non-sensitizing small molecules. Furthermore, the inactivated enzyme posed no risk of sensitization, resulting in the lowest protein residue among all examples, and the irritation score remained low. In Example 5, the increased amount of compound filler enhanced adsorption capacity, further reducing residual sensitizers. Simultaneously, the filler improved the density of the latex film, reducing impurity adhesion and skin contact. Therefore, protein residue was lower than in Example 1, and the irritation score remained low. In Example 6, due to the addition of the preservative system... With increased dosage, the high concentration of p-hydroxyacetophenone's phenolic hydroxyl groups caused slight skin irritation. Furthermore, excessive preservatives occupied the dispersion space of the latex system, reducing the probability of enzyme-protein contact and leading to a slight decrease in degradation efficiency. Consequently, protein residue and irritation scores increased compared to Example 1. In Example 7, the dosage of additives such as o-naphthalenedicarboxylic anhydride and tert-butyl peroxide was doubled. Some unreacted o-naphthalenedicarboxylic anhydride groups formed weak cross-links with skin proteins. The increased dosage of vulcanizing agent also produced trace amounts of small-molecule degradation products. Although rinsed, a small amount remained, resulting in the highest protein residue and irritation scores among all examples. In Comparative Example 1, the absence of composite filler resulted in the lack of the filler's adsorption of small-molecule sensitizers and its protective function on the latex film, leading to easy adhesion of impurities. The increased skin contact area and the application of the latex film resulted in a significantly higher irritation score compared to Example 1, while the protein residue remained similar to that of Example 1 due to the unchanged deproteinization process. Comparative Example 2, by using constant-temperature vulcanization instead of gradient vulcanization, caused localized high temperatures that denatured and coagulated some proteins, reducing the degradation efficiency of the complex enzyme. Simultaneously, the high temperature caused premature evaporation of the lubricant, resulting in a rough latex film surface and increased skin friction irritation. Furthermore, uneven vulcanization led to localized cross-linking defects that released sensitizing substances, resulting in higher protein residue and irritation scores than Example 1. Comparative Example 3, by using a single metalloproteinase instead of the complex enzyme, could only hydrolyze protein peptide bonds but could not break down the significant proportion of glycoproteins in the latex, leading to highly sensitizing glycoprotein residues. Ultimately, this resulted in the highest protein residue and the highest irritation score.

[0103] This application provides a method for preparing ammonia-free deproteinized latex medical surgical gloves: using ammonia-free natural concentrated latex as raw material, in the deproteinization stage, a compound enzyme preparation is used to specifically degrade sensitizing water-soluble proteins, breaking them down into small molecule peptides or amino acids to reduce protein residue and allergenicity. A compound filler is added and embedded in the latex matrix to form a reinforcing skeleton to improve tensile strength, constructing a three-dimensional support network to disperse tear stress. During gradient vulcanization, rubber molecules crosslink to form a three-dimensional network structure, enhancing intermolecular forces, improving tensile strength, and forming a uniform and dense crosslinked structure, reducing molecular chain breakage during tearing, thereby improving tear resistance. During gradient vulcanization, tert-butyl peroxide, through the decomposition of peroxide bonds in its molecular structure, generates highly reactive free radicals that attack the latex molecules. The unsaturated double bonds on the sub-chains initiate cross-linking reactions between molecules. Simultaneously, the accelerator TMTM accelerates the free radical generation rate, driving the latex molecules to form a denser three-dimensional network structure. This significantly reduces chain slippage during stretching, providing stable mechanical support for the glove. o-Naphthalenedicarboxylic anhydride regulates the cross-linking density, preventing excessive vulcanization and embrittlement, thus optimizing tensile and tear resistance. It also acts as a plasticizer to enhance glove flexibility and reduce tightness. Stearic acid smooths the latex film surface, further improving wearing comfort. Medical-grade petroleum jelly assists in mold release and forms an inner lubricating layer, reducing frictional resistance. Deionized water spraying removes residual additives and impurities, reducing potential allergens. A 1.5cm inward roll at the glove opening prevents edge scratches, further enhancing wearing comfort. This solution addresses the problems of poor anti-corrosion stability, high allergenicity, and poor mechanical strength in ammonia-free, deproteinized latex medical surgical gloves.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A type of ammonia-free, deproteinized latex medical surgical glove, characterized in that, The ammonia-free deproteinized latex medical surgical gloves comprise: ammonia-free natural concentrated latex, a compound enzyme preparation, a p-hydroxyacetophenone-1,2-hexanediol compound preservative system, and a composite filler; wherein, the compound enzyme preparation is a mixture of metalloproteinase and glycosyl hydrolase at a mass ratio of 1:1, with an enzyme activity unit of 5000 U / g after mixing; the p-hydroxyacetophenone-1,2-hexanediol compound preservative system is composed of p-hydroxyacetophenone and 1,2-hexanediol at a mass ratio of 1:1-1.2; the composite filler is prepared by adding 0.5-1.0 parts of collagen nanofibers and 0.3-0.6 parts of chitin nanocrystals to 50-60 parts of deionized water, magnetically stirring at room temperature for 20 min, and then ultrasonically treating with 200W power for 20 min in an ultrasonic cleaner; The preparation method of the ammonia-free deproteinized latex medical surgical gloves includes the following steps: (1) In a stainless steel reactor, add 500 parts of deionized water to 1000 parts of 60wt% ammonia-free natural concentrated latex, stir and dilute to a total solid content of 40%, rotate at 150 r / min, heat to 45℃, add 8-12 parts of compound enzyme preparation, adjust pH to 7.0, stir for 6 h, heat to 80℃ and keep warm for 30 min, cool to 30℃, pass through a 300 mesh sieve to obtain deproteinized latex; (2) Using a multifunctional latex mixing tank, add 0.1-0.3 parts of p-hydroxyacetophenone-1,2-hexanediol compound preservative system to the deproteinized latex, stir for 20 min, add 0.8-1.2 parts of composite filler in sequence, stir for 30 min, add o-naphthalene dicarboxylic anhydride, stir for 30 min, add stearic acid, stir for 30 min, add tert-butyl peroxide, stir for 40 min, add accelerator TMTM, stir for 20 min, add antioxidant 1010, stir for 30 min, vacuum stand for degassing for 4 h to obtain raw latex; (3) Select a medical surgical glove mold with polytetrafluoroethylene coating, and after deep cleaning, evenly coat it with a layer of medical petroleum jelly with a thickness of 5μm, and cool it to 40℃ to obtain a pre-treated mold. (4) Immerse the pretreated mold in a 10% calcium chloride solution for 5 min, dry at 100-120℃ for 20 min, immerse it in the raw rubber latex at a speed of 5 cm / s, stay for 60 seconds, take it out at the same speed, hang it vertically to drain for 15 min, dry it in a hot air oven at 80-100℃ for 20 min, and then perform gradient vulcanization in a vulcanization tunnel. After vulcanization, cool the mold to 60℃, rinse it with deionized water spray 3 times, 2 min each time, roll the opening of the glove inward by 1.5 cm to form a sealed rolled edge, vacuum dry it, pack it into a sterile packaging bag, sterilize it with ethylene oxide, and desorb it for 48-72 h to obtain ammonia-free deproteinized latex medical surgical gloves.

2. The ammonia-free deproteinized latex medical surgical glove according to claim 1, characterized in that, Step (1) pH adjustment is performed using a 10% citric acid solution.

3. The ammonia-free deproteinized latex medical surgical glove according to claim 1, characterized in that, Step (2): The amount of o-naphthalene dicarboxylic anhydride added is 1.5-2.5 parts, the amount of stearic acid added is 0.5-1.5 parts, the amount of tert-butyl peroxide added is 10-14 parts, the amount of accelerator TMTM added is 1.3-1.7 parts, the amount of antioxidant 1010 added is 0.2-0.4 parts, the stirring speed is 200 r / min, the temperature is 30℃, the vacuum degree of vacuum standing degassing is -0.08 MPa, and the temperature is 25℃.

4. The ammonia-free deproteinized latex medical surgical glove according to claim 1, characterized in that, Step (3) Deep cleaning process involves first soaking in 5% sodium hydroxide solution at 50℃ for 20 minutes, rinsing with deionized water until neutral, immersing in 75% ethanol solution for 3 minutes for disinfection, air drying, and then preheating in an oven at 120℃ for 15 minutes.

5. The ammonia-free deproteinized latex medical surgical glove according to claim 1, characterized in that, Step (4) Vacuum drying process is to dry in a vacuum drying oven at 60℃ and -0.08MPa for 3h.

6. The ammonia-free deproteinized latex medical surgical glove according to claim 1, characterized in that, Step (4) The gradient vulcanization process is to keep the temperature at 60℃ for 5 minutes, raise the temperature to 100℃ and keep it for 10 minutes, raise the temperature to 135℃ and keep it for 25 minutes, with a heating rate of 10℃ / min. The ethylene oxide sterilization process is to use ethylene oxide with a concentration of 600mg / L, at a temperature of 50℃, for 6 hours.

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