Method for preparing waterproof moisture-permeable polyurethane gloves

Abstract

The invention relates to the technical field of preparation of polyurethane gloves, in particular to an innovative preparation method of waterproof and moisture-permeable polyurethane gloves with remarkably improved waterproof, moisture-permeable and mechanical properties, which comprises the steps of lining finishing, drying after dipping in a coagulator, drying after dipping in a polyurethane foaming slurry, drying after dipping in a polyurethane slurry, and drying after dipping in a particle slurry. In the process of drying the hand mold after dipping, the rotation of the hand mold is utilized, and the improvement of the hand mold structure is matched, so that air flow can be generated in the hand mold, and the air flow can be guided to the surface of the hand mold and surrounds the dipping part of the hand mold to form air flow, and moisture generated by drying the surface of the hand mold is guided, so that the moisture on the surface of the hand mold is quickly removed; and the hand mold drying process is accelerated, so that the hand mold is uniformly dried, the problems that the waterproof performance is reduced, the mechanical performance becomes poor and the moisture permeability is changed after the polyurethane glove is formed are solved, and the waterproof and moisture permeability of the polyurethane glove is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of polyurethane glove preparation, and in particular to an innovative preparation method of waterproof and breathable polyurethane gloves with significantly improved waterproof, breathable and mechanical properties. Background Art

[0002] Workers' hands sweat easily during work, and conventional gloves struggle to quickly remove sweat, resulting in reduced hand comfort and, in severe cases, allergies and dermatitis. Half-palm or yarn gloves offer some moisture permeability, but they lack protection against oil and water, limiting their application in some areas. Polyurethane gloves (PU gloves) are ideal protective gloves for workers because they are both waterproof and oil-resistant while also offering a certain degree of moisture permeability.

[0003] On November 22, 2021, the applicant disclosed in the Chinese invention patent application number 202111385860.8 a waterproof and breathable polyurethane glove, which adopts an impregnation molding process. The first layer is impregnated with a porous polyurethane coating, and the second layer is impregnated with a non-porous polyurethane coating. The second impregnation layer can prevent contamination by impurities such as dust and detergents, and block the first porous coating. The compound between the two coatings also improves the mechanical strength of one coating, effectively reducing the decrease in moisture permeability caused by the deformation of the bubbles of one coating due to external force.

[0004] In addition, the patent also discloses a production device for preparing waterproof and breathable polyurethane gloves. A purification mechanism and a filtering mechanism are installed at the bottom of the base of the production device. The purification mechanism can filter the gas entering the drying box to prevent impurities and dust contained in the gas from being sprayed on the outer surface of the hand mold, thereby improving the quality of drying the gloves.

[0005] However, the above-mentioned production device does not solve the problem of moisture accumulation on the surface of the hand mold during the drying process, resulting in uneven and slow drying. In addition, during the production process of polyurethane gloves, at least four drying and heating steps are required. As a result, if the hand mold dries unevenly during any of the drying steps, the quality of the finished polyurethane gloves will be affected.

[0006] At the same time, no matter whether it is the impregnation of coagulant, polyurethane foam slurry or polyurethane slurry, they all need to be turned horizontally into the oven for drying after impregnation, which requires the drying equipment to be set up in an open manner. Therefore, once an exhaust mechanism is set on the drying box to extract moisture, it is bound to cause external gas to enter, and the entry of external gas will disrupt the temperature balance in the drying box.

[0007] Therefore, there is an urgent need for a preparation method that can quickly drain away the moisture generated by drying the hand mold during the preparation process of polyurethane gloves, especially during the drying process after dipping, while preventing external air from entering the drying box to disrupt the temperature balance, thereby improving the quality of the polyurethane gloves during the preparation process. Summary of the Invention

[0008] To address the above problems, the present invention provides a method for preparing waterproof and breathable polyurethane gloves. By utilizing the rotation of the hand mold itself during the drying process after dipping, combined with improvements to the hand mold structure, airflow can be generated inside the hand mold. The airflow can be directed to the hand mold surface, surrounding the dipped area of ​​the hand mold to form air flow, which guides moisture generated by drying on the hand mold surface, accelerates the drying process of the hand mold, and ensures uniform drying of the hand mold. This avoids the problems of reduced waterproof performance, deterioration of mechanical properties, and changes in moisture permeability of the polyurethane gloves after molding, thereby improving the waterproof and moisture permeability of the polyurethane gloves.

[0009] To achieve the above object, the present invention provides the following technical solutions: A method for preparing waterproof and breathable polyurethane gloves comprises the following steps: Step a: After the liner is put on the handform and arranged to fit, the handform carrying the liner is vertically placed in the coagulant tank for immersion, the handform is lifted until the coagulant stops dripping, the handform is swung to be transported horizontally, and the handform rotates around its own central axis and enters the oven, the oven temperature is 50-60° C., for example, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60° C., and the drying and heating is performed for 10-20 minutes, for example, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 minutes; After drying in step b and step a, the hand mold is slowly and vertically placed into the polyurethane foam slurry tank for immersion, and then quickly lifted up, and the hand mold is tilted up to form an angle of 30° with the horizontal plane, and the hand mold is rotated around its own central axis for 5 minutes; After the rotation in step c and step b is completed, the hand mold is swung to be transported horizontally, and the hand mold rotates around its own central axis and enters the drying oven, and is heated at 90° C. for 20 minutes; After the hand mold in step d and step c is dried, it is slowly and vertically placed in a polyurethane slurry tank to be dipped in a second layer of slurry. After the dipping is completed, the hand mold is quickly lifted and dripped with slurry for 3 minutes, swung to be transported horizontally, and rotated around its own central axis into an oven at 100-125° C., for example, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 120, 121, 122, 123, 124, 125° C., and dried and heated for 20-30 minutes, for example, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 minutes; After drying the handforms in step e and step d, the handforms are cooled to 30° C., vertically placed in a particle slurry tank to dip in the particle slurry, and after dripping for 3 minutes, the handforms are swung to be transported horizontally and rotated around their own central axis to enter an oven at 100-125° C., for example, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 120, 121, 122, 123, 124, or 125° C., and heated and dried for 20-30 minutes, for example, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 minutes, to form waterproof and breathable polyurethane gloves; The waterproof and breathable polyurethane gloves formed in step f and step d are demoulded after cooling, trimmed, and then packaged; In the above steps a, b, c, d and e, when the hand mold rotates around its own central axis, an air flow layer surrounds the outer side of the immersed part of the hand mold.

[0010] As an improvement, in step a, before the hand mold is dipped in the coagulant, the lining is pretreated with infrared rays, and the infrared ray wavelength range is 0.7 to 4.0 μm, for example, 0.7, 1.0, 1.2, 1.5, 1.7, 2.0, 2.3, 2.5, 2.7, 3.0, 3.2, 3.5, 3.7, and 4.0 μm.

[0011] As an improvement, in the step b, the polyurethane foam slurry is based on a polyether polyurethane prepolymer, and the polyurethane foam slurry also includes polyethylene glycol with a mass fraction of 5%-10% (for example, 5, 6, 7, 8, 9, 10%) and an organosilicon modifier with a mass fraction of 0.2%-0.5% (for example, 0.2, 0.3, 0.4, 0.5%), the molecular weight of the polyethylene glycol is 2000-4000 (the molecular weight here is the relative molecular weight), and the organosilicon modifier is γ-aminopropyltriethoxysilane or its derivatives.

[0012] As an improvement, in step d, the second layer of slurry is a core-shell structured polyurethane emulsion, the core layer is made of high-hardness isocyanate polyurethane, and the shell layer is made of flexible polyether polyurethane, and the mass ratio of the two is 3:7-5:5.

[0013] As an improvement, the preparation method of the core-shell polyurethane emulsion comprises the following steps: Step t1, preparation of core layer polyurethane prepolymer: add isocyanate type polyurethane prepolymer raw material to a four-necked flask equipped with a stirrer, thermometer and reflux condenser, start stirring, control the speed at 100-150r / min, raise the temperature to 80-85°C, slowly add measured acetone, stir evenly to fully dissolve the prepolymer, add chain extender ethylenediamine, control the reaction temperature at 80-85°C, react for 2-3h, stop the reaction, and obtain a core layer polyurethane prepolymer solution; Step t2, Preparation of Shell Polyurethane Prepolymer: Take another four-necked flask, add polyether polyurethane prepolymer raw material, and control the stirring speed at 100-150 r / min. Raise the temperature to 70-75°C, add acetone and stir to dissolve, then add the measured chain extender ethylenediamine, control the reaction temperature at 70-75°C, and react for 1.5-2 hours to obtain a shell polyurethane prepolymer solution; Step t3, preparing a core-shell emulsion, slowly adding the shell polyurethane prepolymer solution to the core polyurethane prepolymer solution while stirring, increasing the stirring speed to 200-250 r / min, and after uniform mixing, continuing stirring for 30 minutes, adding the compounded emulsifier to the above mixed solution, stirring for 15-20 minutes to fully emulsify the prepolymer, adding deionized water to the emulsion for dispersion, the amount of water added being 1-1.5 times the total mass of the polyurethane prepolymer, and stirring and dispersing at a high speed of 1000-1500 r / min for 30-40 minutes to form a stable emulsion, adding triethylamine for neutralization, adjusting the pH value of the emulsion to 7.5-8.5, stirring for 10-15 minutes, and removing acetone by reduced pressure distillation to obtain a core-shell polyurethane emulsion.

[0014] As an improvement, in step e, 2%-5% by mass of nano-titanium dioxide particles and 1%-2% by mass of a waterproofing agent are added to the particle slurry, and the waterproofing agent is perfluorobutanesulfonic acid in the organic fluorine waterproofing agent.

[0015] As an improvement, the air flow layer formed at the immersed portion of the hand mold is formed by the rotation of the gas ejected from the pores at the unimmersed portion of the hand mold toward the immersed portion.

[0016] As an improvement, the hand mold consists of a mold and a rotating shaft. A planetary gear set is arranged inside the hand mold. Through the planetary gear set, the mold and the rotating shaft are arranged to rotate relative to each other at a differential speed. The rotating shaft is swingably connected to the hanging chain conveyor and is driven to move by the hanging chain conveyor. A fan blade is provided at the end of the rotating shaft located inside the mold. The fan blade rotates synchronously with the rotating shaft to form an airflow, and the airflow is discharged outward through the air holes.

[0017] As an improvement, the planetary gears in the planetary gear set are connected and installed through the end cover provided on the unimpregnated end of the mold. The end cover wraps the rotating shaft to form a guide wheel and a limit block. The guide wheel is a circular roller, the limit block is a square, and a roller-shaped friction wheel is provided on the rotating shaft. Along the moving path of the hand model during self-rotation, a guide friction track is laid parallel to the moving path. The guide friction track includes a guide part, a limiting part and a friction part which are arranged in parallel. The guide part is arranged in rolling cooperation with the guide wheel, the limiting part is arranged in sliding cooperation with the limiting block, and the friction part is arranged in rolling and friction cooperation with the friction wheel.

[0018] As an improvement, the fan blades rotate with the shaft, and gas is introduced from the air inlet holes opened on the end cover, and a filter screen is provided at the air inlet holes to filter the gas.

[0019] The beneficial effects of the present invention are: (1) The present invention achieves this by rotating the hand mold horizontally during drying (self-rotating the hand mold in a horizontal conveying state), combining the unique shape of the hand mold (i.e., the diameter of the immersed end of the hand mold is smaller than that of the unimmersed end) and improving the structure of the hand mold. This allows the hand mold to generate airflow inside during self-rotation, and the airflow can be directed to the surface of the hand mold, surrounding the immersed part of the hand mold to form air flow, thereby directing the heat and moisture generated by drying, balancing the drying temperature of the hand mold surface, and quickly removing the moisture generated on the hand mold surface. This avoids the problems of reduced waterproof performance, deterioration of mechanical properties, and change in moisture permeability of polyurethane gloves after molding, thereby improving the waterproof and moisture permeability of polyurethane gloves. In addition, the air cover formed by the air flow can also isolate the hand mold, preventing dust and impurities from falling during the drying process. (2) The present invention pre-treats the lining with infrared rays. The high-energy infrared rays (usually with a wavelength of 200-400 nm) in the infrared rays can destroy chemical bonds such as CC and CH on the surface, generating free radicals. Oxygen (O2) in the air participates in the reaction, causing the free radicals to combine with oxygen to form polar oxygen-containing groups such as hydroxyl (-OH), carboxyl (-COOH), and carbonyl (C=O). These groups significantly increase the surface hydrophilicity and chemical activity, and increase the surface energy (from about 30-40 mN / m to 50-60 mN / m), making the coagulant (usually a water-based solution) easier to wet and adsorb, thereby increasing the activity of the lining surface and enhancing the binding force with the coagulant. (3) The present invention adds polyethylene glycol to the polyurethane foam slurry. Polyethylene glycol has good hydrophilicity and can form hydrophilic channels in the polyurethane slurry. When the gloves come into contact with water vapor, the water vapor can be quickly transferred through these hydrophilic channels, thereby significantly improving the moisture permeability of the gloves. (4) The present invention adds an organosilicon modifier to the polyurethane foam slurry. The organosilicon modifier can reduce the surface tension of the polyurethane slurry and make the bubbles generated during the foaming process more uniform and stable. During the foaming process, if the bubbles are of different sizes or easily break, it will lead to uneven internal structure of the gloves, affecting their mechanical properties and comfort. The organosilicon modifier can effectively improve this situation, making the foam structure more stable, thereby improving the overall strength, elasticity and other mechanical properties of the gloves, and also helping to improve the flatness and smoothness of the glove surface. (5) The present invention uses a core-shell structured polyurethane emulsion as the second layer slurry. The core layer uses high-hardness isocyanate polyurethane, which has a strong force between its molecular chains and has high hardness and modulus. When the glove is subjected to external force, the core layer can resist the deformation caused by the external force like a skeleton and bear most of the stress, thereby effectively preventing the damage to the internal structure of the glove and improving the overall rigidity and deformation resistance of the glove. The shell layer uses a polyether polyurethane with good flexibility, which gives the emulsion good elasticity and ductility. During the deformation process of the glove such as bending and stretching, the shell layer can undergo reversible deformation with the external force, absorb and disperse the external force energy, and avoid stress concentration in a certain part causing material rupture.

[0020] In summary, the polyurethane gloves of the present invention have the advantages of high moisture permeability, large water contact angle, excellent waterproof performance, enhanced mechanical properties, etc., and are particularly suitable for the technical field of preparing moisture-permeable and waterproof polyurethane gloves, and have broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic flow chart of the preparation method of Example 1 of the present invention; Figure 2 This is a schematic diagram of the three-dimensional structure of the hand model in Example 2 of the present invention. Figure 1 ; Figure 3 This is a schematic diagram of the three-dimensional structure of the hand model in Example 2 of the present invention. Figure 2 ; Figure 4 This is a schematic diagram of a partial cross-sectional structure of a hand model according to embodiment 2 of the present invention; Figure 5 This is a schematic diagram of the three-dimensional structure of the end cover of Example 2 of the present invention; Figure 6 This is a schematic diagram of the coordination structure of the planetary gear set according to embodiment 2 of the present invention; Figure 7 This is a schematic diagram of the three-dimensional structure of the rotating shaft in Example 2 of the present invention; Figure 8 This is a schematic diagram of the partial structure of the friction track in Example 2 of the present invention; Figure 9 Schematic diagram of the internal structure of the mold of the present invention; Figure 10This is a schematic diagram of the cross-sectional structure of the limiting pin of the present invention; Figure 11 This is a schematic diagram of the hand model reversal in which the guide portion and the guide wheel cooperate with each other in the present invention.

[0022] Markings in the accompanying drawings: hand mold 1, air hole 10, impregnated part 11, unimpregnated part 12, limiting ring 121, mold 2, gas collecting area 20, air inlet 200, gas flow channel 201, filter screen 202, end cover 21, mounting shaft 210, flange 211, limiting pin 212, ball 213, guide wheel 214, limiting block 215, rotating shaft 3, fan blade 31, friction wheel 33, planetary gear set 4, planetary gear 41, sun gear 42, ring gear 43, friction track 5, guide part 51, limiting part 52, friction part 53. DETAILED DESCRIPTION

[0023] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0024] The specific embodiments of the present invention are described in detail below. However, it should be noted that the protection scope of the present invention is not limited by these specific embodiments, but is determined by the claims in the appendix.

[0025] All publications, patent applications, patents, and other references mentioned in this specification are incorporated herein by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings commonly understood by those skilled in the art. In the event of conflict, the definitions in this specification will prevail.

[0026] When this specification uses the prefix "well known to those skilled in the art", "prior art" or similar terms to introduce materials, substances, methods, steps, devices or components, etc., the objects introduced by the prefix include those conventionally used in the art when the present invention is proposed, but also include those that are not commonly used at present but will become generally recognized in the art to be suitable for similar purposes.

[0027] It should be noted that two or more aspects (or implementation methods) disclosed in the context of this specification can be arbitrarily combined with each other, and the technical solutions (such as methods or systems) thus formed are part of the original disclosure of this specification and also fall within the scope of protection of the present invention.

[0028] Unless otherwise specified, all percentages, parts, ratios, etc. mentioned in this specification are based on weight, unless the weight basis does not conform to the general understanding of those skilled in the art.

[0029] Example 1: like Figure 1 As shown, a method for preparing waterproof and breathable polyurethane gloves comprises the following steps: Step a: After the inner liner is put on the hand form and adjusted to fit, the hand form with the inner liner is vertically placed in the coagulant tank for immersion. The hand form is lifted until the coagulant stops dripping, the hand form is swung to be transported horizontally, and the hand form rotates around its own central axis and placed in an oven at 50-60°C for 10-20 minutes; After drying in step b and step a, the hand mold is slowly and vertically placed into the polyurethane foam slurry tank for immersion, and then quickly lifted up, and the hand mold is tilted up to form an angle of 30° with the horizontal plane, and the hand mold is rotated around its own central axis for 5 minutes; After the rotation in step c and step b is completed, the hand mold is swung to be transported horizontally, and the hand mold rotates around its own central axis and enters the drying oven, and is heated at 90° C. for 20 minutes; After the hand molds in steps d and c are dried, they are slowly and vertically placed in a polyurethane slurry tank to be dipped in the second layer of slurry. After the dipping is completed, the hand mold is quickly lifted up and dripped with slurry for 3 minutes, then swung to a horizontal position for transportation, and rotated around its own central axis into an oven at 100-125°C for 20-30 minutes of drying. After drying in step e and step d, the hand mold is cooled to 30° C., vertically placed in a particle slurry tank to immerse the particle slurry. After dripping the slurry for 3 minutes, the hand mold is swung to be transported horizontally and rotated around its own central axis into an oven at 100-125° C. for 20-30 minutes to form a waterproof and breathable polyurethane glove. The waterproof and breathable polyurethane gloves formed in step f and step d are demoulded after cooling, trimmed, and then packaged; In the above steps a, b, c, d and e, when the hand mold rotates around its own central axis, an air flow layer surrounds the outer side of the immersed part of the hand mold.

[0030] It should be noted that after the polyurethane gloves are impregnated with polyurethane and during the coating drying process, uneven drying and slow drying will affect the performance of the formed polyurethane gloves, as follows: Reduced waterproof performance: Waterproofing failure (increased risk of leakage), uneven drying, and uncured "weak spots" (such as pinholes, cracks, or unfused particles) on or within the coating surface allow water to easily penetrate the inside of the glove through these defects. For example, when the center of a thick coating is not completely dry, the outer layer solidifies to form a "shell." The liquid polyurethane inside may swell or fall off upon contact with water, forming leakage channels and slowing drying. For solvent-based polyurethane, incompletely evaporated solvent will reduce the adhesion of the coating to the substrate (such as the glove base fabric), making the coating prone to delamination when exposed to water. For water-based polyurethane, undried water will dilute the coating, resulting in discontinuous film formation and a damaged waterproof barrier.

[0031] The water pressure resistance performance decreases, and the insufficiently dried coating structure is loose and cannot withstand the water pressure. When it comes into contact with liquids (such as disinfectants in medical scenarios and industrial liquids), the liquids can easily penetrate into the inside of the gloves and lose their protective function.

[0032] Deterioration of mechanical properties: Decreased strength and wear resistance, uneven drying, and partially incomplete curing of the coating (e.g., residual solvent or unreacted polyurethane prepolymer within thick coatings) lead to uneven overall crosslinking density. Polymer chain segments in areas that haven't dried thoroughly are highly mobile and have low mechanical strength, making them susceptible to breakage or wear under stresses such as stretching and friction. Gloves are prone to breakage, tearing, or surface fuzzing. Slow drying and prolonged wet coatings are susceptible to external forces (e.g., stretching and folding during glove production), leading to microcracks or structural relaxation within the coating. These "weak points" form after curing, significantly reducing mechanical strength (e.g., elongation at break, tensile strength).

[0033] Elasticity and resilience deteriorate, and uneven or slow drying will cause the polyurethane molecular chains to be unable to fully cross-link into a network structure, the intermolecular force is weak, the elasticity of the coating decreases, and the gloves are easily deformed when worn and difficult to restore to their original shape, affecting the fit and comfort.

[0034] Changes in moisture permeability: Abnormal moisture permeability (usually increased) indicates uneven drying. Unevaporated solvents or incompletely cured "holes" in the coating may create through-pores, allowing water vapor to pass more easily through the coating, enhancing moisture permeability. Gloves designed for low moisture permeability (such as waterproofing) can reduce protective effectiveness. Slow drying and incomplete evaporation of solvents (especially water in water-based polyurethane) can lead to "water stagnation" or microporous structures within the coating, increasing the water vapor conduction path. Furthermore, incompletely cured polyurethane may further expand pores due to swelling, leading to increased moisture permeability.

[0035] Uneven moisture permeability and uneven drying can lead to differences in porosity and density in different areas of the coating, resulting in local inconsistencies in moisture permeability and affecting the overall functionality of the gloves (such as the moisture resistance of medical gloves).

[0036] Therefore, the present invention requires a layer of air flow surrounding the outside of the immersed part of the hand mold to protect against dust and impurities during the drying process, while utilizing air flow to balance the temperature of various parts of the hand mold and ensure that moisture generated during the drying process on the surface of the hand mold is quickly removed to avoid moisture accumulation.

[0037] During the polyurethane glove production process, the mold is rotated horizontally after being impregnated with coagulant and slurry before entering the drying oven. This is mainly to achieve uniform drying and avoid slurry accumulation, thereby ensuring the quality and performance of the gloves. Specifically: 1. Uniform drying: The horizontal rotation method can evenly heat all parts of the mold surface, avoiding local overheating or overcooling. If the mold directly enters the oven in a fixed posture, the distance and angle between different parts and the heat source will be different, and the degree of heating will vary. For example, the temperature on the side close to the heat source may be too high, causing the slurry to dry quickly or even burn, while the side away from the heat source will not dry sufficiently, affecting the overall quality of the gloves. By rotating horizontally, the coagulant and slurry on the mold surface can be dried in a relatively consistent temperature environment, making the drying effect more uniform, thereby ensuring the stable performance of the gloves. In addition, the hand mold of the present invention can also use gas flow to drive the flow of heat while rotating horizontally, making the overall temperature of the hand mold more uniform, further promoting the drying effect.

[0038] 2. Avoid slurry accumulation. After impregnation with the coagulant or slurry, the slurry distribution on the glove surface may be uneven and exhibit a certain degree of fluidity. If the mold is placed directly into the oven without rotating horizontally, the slurry may flow downward under the influence of gravity and accumulate at the bottom or certain areas of the mold, resulting in inconsistent thickness across the glove, affecting its appearance and performance. During the horizontal rotation process, the mold is in a dynamic state of motion, which effectively disperses the slurry, reduces slurry accumulation caused by gravity, and evenly distributes the slurry across the glove surface, helping to produce a glove product with uniform thickness and stable quality. The full, surface-surrounding airflow blows from the large-diameter end of the hand mold downward to the small-diameter end. Therefore, this surrounding airflow has no impact on the flow of the impregnating coagulant or slurry, and it also binds the impregnating coagulant or slurry to the hand mold surface, creating a superior application effect.

[0039] Therefore, the air flow layer formed on the surface of the mold during its horizontal rotation can bring beneficial effects in terms of drying efficiency, quality stability, process control, etc., and optimize the polyurethane glove preparation process.

[0040] The details are as follows: Accelerates the drying process: The airflow layer accelerates the evaporation of moisture and solvents from the glove surface. The high-speed airflow continuously removes vaporized water or solvent molecules from the glove surface due to heating, disrupting the gas-liquid equilibrium near the surface and allowing the internal moisture and solvent to diffuse to the surface and evaporate more quickly, thereby shortening drying time and improving production efficiency.

[0041] Uniform Drying: It helps evenly distribute temperature and humidity across the mold surface. Uniform and stable airflow ensures more consistent heat transfer across the mold, preventing localized overheating or overcooling. This ensures that the coagulant and slurry dry evenly across the glove surface, preventing uneven thickness and surface roughness caused by uneven drying, and improving glove quality consistency.

[0042] Reduced Impurity Adhesion: Continuous airflow creates a barrier, reducing the amount of dust, impurities, and other particles in the air that adhere to the glove surface. In a production environment, suspended particles are unavoidable in the air. The airflow layer can blow these impurities away from the mold surface, reducing the risk of contamination on the glove surface, ensuring surface cleanliness, and ultimately improving the glove's appearance, quality, and performance.

[0043] Stable process environment: The airflow layer can isolate the mold from external environmental interference to a certain extent and stabilize the microenvironment around the mold. For example, the impact of temperature and humidity fluctuations in the external environment on the mold will be weakened by the airflow layer, keeping the mold under relatively stable temperature and humidity conditions, which is conducive to precise control of production process parameters and ensuring consistent product quality.

[0044] In a preferred embodiment, in step a, the coagulant-impregnated liner is treated with infrared radiation, preferably at a wavelength of 1.5 μm. This infrared radiation maintains the liner's moisture content at a uniform level during finishing. During the subsequent sizing process, this effectively prevents sizing penetration and the resulting poor hand feel. It also avoids localized sizing seepage or poor adhesion caused by uneven coagulant content in the liner, effectively improving the quality of the gloves. In practical applications, infrared heating systems typically remove 35% to 40% of the fabric's moisture content. After coagulant impregnation, the liner's liquid content can be effectively reduced from 75% to 45% to 50%. This level of moisture removal not only reduces the burden on the subsequent drying process but also ensures the fabric is at a suitable moisture level before entering the next stage of processing. (If the lining is too wet and contains too much coagulant, the gloves will have poor adhesion after being dipped in slurry and will not be durable; if it is too little, the slurry will seep through and the feel of the gloves will deteriorate. After the lining is dipped in coagulant, it will generally flatten after one minute, resulting in high moisture content in the fingertips of the lining and low moisture content in the cuffs. When heated by infrared rays, the fingertips with high moisture content absorb more heat and dry faster, while the cuffs dry more slowly, thus achieving overall moisture balance in the gloves.

[0045] High heating efficiency is another outstanding feature of infrared drying technology. Infrared radiation transfers energy to moisture in fabrics in a very short time, causing the moisture to rapidly heat up and evaporate. This rapid heating process significantly shortens drying time and improves production efficiency. The infrared radiation energy is directly absorbed by water and converted into heat, reducing energy loss during the transfer process and making the drying process more energy-efficient and efficient. This not only meets today's demand for energy conservation and environmental protection, but also reduces production costs for businesses and improves their competitiveness.

[0046] In addition, in a preferred embodiment of the present invention, in step b, the polyurethane foam slurry is based on a polyether polyurethane prepolymer, and the polyurethane foam slurry also includes a mass fraction of 5%-10% polyethylene glycol and a mass fraction of 0.2%-0.5% silicone modifier, the molecular weight of the polyethylene glycol is 2000-4000, and the silicone modifier is γ-aminopropyltriethoxysilane or its derivatives. In addition, auxiliary agents such as foaming agents and foam stabilizers are also added to the polyurethane foam slurry.

[0047] Polyether polyurethane prepolymers have good flexibility and hydrolysis resistance. During the actual use of gloves, they need to be frequently bent and stretched. The flexibility of polyether polyurethane prepolymers can ensure that the gloves are not prone to cracking under these operations; their hydrolysis resistance can extend the service life of gloves in humid environments and avoid the degradation of material properties due to moisture. They are particularly suitable for the preparation of gloves that need to come into contact with water or be used in humid environments. At the same time, polyether polyurethane prepolymers have good processing performance and are easy to mix evenly with other additives, thereby meeting different production process requirements.

[0048] As a non-limiting example of an organosilicon modifier, γ-aminopropyltriethoxysilane or its derivatives are formed by chemically grafting amino groups (-NH2) with polydimethylsiloxane (PDMS) as the main chain. Its molecular structure is: H2N(CH2)3Si(OC2H5)3 Among them, the amino group is located at the γ position of the silicon atom, and three ethoxy groups (-OC2H5) serve as hydrolysis active groups.

[0049] Responsive Design: Amino group (-NH2): can undergo urea reaction with isocyanate group (-NCO) in polyurethane prepolymer, covalently bond the siloxane chain segment to the polyurethane molecular network, and form a stable cross-linked structure.

[0050] Ethoxy group (-OC2H5): hydrolyzes in aqueous slurry to form silanol group (-SiOH), which further forms hydrogen bonds or covalent bonds with hydroxyl groups (-OH) on the surface of the substrate to enhance interfacial bonding.

[0051] The mechanism of action and performance improvements are as follows: Foam stability optimization: Surface tension regulation: The polysiloxane chain segment has an extremely low surface tension (about 20mN / m), which can quickly spread on the slurry surface, reduce the interfacial energy between bubbles, inhibit bubble merging and rupture, and make the foaming pore size distribution more uniform (pore size deviation ≤10%).

[0052] Dynamic stabilization effect: The polar groups of amino groups can be adsorbed on the surface of the bubble liquid film to form an elastic interface layer, which can resist the mechanical stress during the foaming process (such as centrifugal force during rotary dipping) and reduce foam collapse.

[0053] Improved cross-linking density: The reaction between amino groups and isocyanate groups introduces silicon-oxygen bonds (Si-O-Si) into the polyurethane network. The bond energy (452kJ / mol) is higher than that of ordinary CC bonds (348kJ / mol), significantly improving the material's tensile strength (+20%-30%) and tear resistance (+15%-20%).

[0054] Stress dispersion mechanism: The flexibility of the silicone chain segment can buffer external stress, avoid cracking caused by stress concentration, and increase the glove's elongation at break to 300%-400%.

[0055] Synergistic effect: Combination with polyethylene glycol (PEG): The hydrophilicity of PEG complements the hydrophobicity of silicone, constructing a "hydrophilic-hydrophobic" microphase separation structure in the slurry. This not only improves the moisture permeability (1500-2000g / (m²·24h)), but also inhibits PEG crystallization through the steric hindrance effect of the siloxane chain segment, maintaining the flexibility of the material.

[0056] The performance indicators of the polyurethane gloves with added silicone modifier of the present invention and traditional polyurethane gloves are compared in Table 1 below: Table 1 In addition, in some preferred embodiments, in step d, the second layer slurry is a core-shell structured polyurethane emulsion, the core layer uses high-hardness isocyanate polyurethane, and the shell layer uses flexible polyether polyurethane, and the mass ratio of the two is 3:7-5:5.

[0057] Specifically, the preparation method of the core-shell polyurethane emulsion comprises the following steps: Step t1, preparation of core layer polyurethane prepolymer: add isocyanate type polyurethane prepolymer raw material to a four-necked flask equipped with a stirrer, thermometer and reflux condenser, start stirring, control the speed at 100-150r / min, raise the temperature to 80-85°C, slowly add measured acetone, stir evenly to fully dissolve the prepolymer, add chain extender ethylenediamine, control the reaction temperature at 80-85°C, react for 2-3h, stop the reaction, and obtain a core layer polyurethane prepolymer solution; Step t2, Preparation of Shell Polyurethane Prepolymer: Take another four-necked flask, add polyether polyurethane prepolymer raw material, and control the stirring speed at 100-150 r / min. Raise the temperature to 70-75°C, add acetone and stir to dissolve, then add the measured chain extender ethylenediamine, control the reaction temperature at 70-75°C, and react for 1.5-2 hours to obtain a shell polyurethane prepolymer solution; Step t3, preparing a core-shell emulsion, slowly adding the shell polyurethane prepolymer solution to the core polyurethane prepolymer solution while stirring, increasing the stirring speed to 200-250 r / min, and after uniform mixing, continuing stirring for 30 minutes, adding the compounded emulsifier to the above mixed solution, stirring for 15-20 minutes to fully emulsify the prepolymer, adding deionized water to the emulsion for dispersion, the amount of water added being 1-1.5 times the total mass of the polyurethane prepolymer, and stirring and dispersing at a high speed of 1000-1500 r / min for 30-40 minutes to form a stable emulsion, adding triethylamine for neutralization, adjusting the pH value of the emulsion to 7.5-8.5, stirring for 10-15 minutes, and removing acetone by reduced pressure distillation to obtain a core-shell polyurethane emulsion.

[0058] The core-shell structure tightly integrates two polyurethanes with different properties, creating a structural system that balances rigidity and flexibility. When subjected to external forces, the core layer bears the primary stress, while the shell layer deforms to relieve the stress and evenly distributes it throughout the structure. The two interact to effectively enhance the material's resistance to external forces, giving the glove both high strength and good toughness, significantly enhancing its mechanical strength.

[0059] As a non-limiting example of a core-shell structured polyurethane emulsion, the core layer raw material is a high-hardness isocyanate-type polyurethane prepolymer with an isocyanate group (-NCO) content controlled at 4%-6% and a hydroxyl value of 20-30 mgKOH / g.

[0060] As a non-limiting example of a core-shell structured polyurethane emulsion, the shell layer raw material is a flexible polyether polyurethane prepolymer with a hydroxyl value of 50-60 mgKOH / g and an isocyanate group (-NCO) content of 2%-3%.

[0061] As a non-limiting example of a core-shell polyurethane emulsion, the emulsifier is a compound of a nonionic emulsifier and an anionic emulsifier. The nonionic emulsifier can be nonylphenol polyoxyethylene ether (NP-10), and the anionic emulsifier can be sodium dodecylbenzene sulfonate (SDBS). The mass ratio of the two is 2:1. The total amount of the emulsifier is 3%-5% of the total mass of the polyurethane prepolymer. The neutralizer is triethylamine, and the amount is 1.0-1.2 times the carboxyl content in the emulsion. The chain extender is ethylenediamine, and the amount is 0.8-0.9 times the amount of the isocyanate group. The solvent is acetone, and the amount is 30%-50% of the total mass of the polyurethane prepolymer to reduce the viscosity of the system and facilitate the reaction.

[0062] In a preferred embodiment, in step e, 2%-5% by mass of nano-titanium dioxide particles and 1%-2% by mass of a waterproofing agent are added to the particle slurry, and the waterproofing agent is perfluorobutanesulfonic acid in the organic fluorine waterproofing agent.

[0063] The core component of organic fluorine water repellents is a surfactant or polymer containing a fluorocarbon chain. Fluorine's low surface energy is the primary component, achieving water repellency. These typically include a fluorocarbon surfactant (the primary component, accounting for 60%-80%) and auxiliary components (accounting for 20%-40%).

[0064] Fluorocarbon surfactant structural characteristics: the molecule contains long-chain fluorocarbon groups (such as C n F 2n+1 -, n = 6-12), with a hydrophilic group (such as carboxyl, sulfonic acid, polyoxyethylene, etc.) connected to the end.

[0065] Typical varieties: Short-chain fluorocarbon surfactants: such as perfluorohexane sulfonic acid (PFHxS, C6), perfluorooctane sulfonic acid (PFOS, C8, gradually being replaced due to environmental restrictions), and perfluorobutane sulfonic acid (PFBS, C4, an environmentally friendly alternative).

[0066] Fluorocarbon acrylate copolymer: By copolymerizing fluorocarbon monomers (such as dodecafluoroheptyl methacrylate) with acrylate monomers, a polymer containing fluorocarbon side chains is formed, which has both waterproofness and film-forming properties.

[0067] Auxiliary ingredients include: Solvent / dispersant: water (aqueous system), ethanol (solubilizer), or non-ionic surfactant (such as polyoxyethylene ether) to ensure uniform dispersion of fluoride.

[0068] Stabilizer: Polyols (such as propylene glycol) or small molecule organic acids (such as acetic acid) prevent fluorocarbon chains from agglomerating and improve emulsion stability.

[0069] Crosslinker (optional): A small molecule containing hydroxyl or amino groups (such as ethylenediamine) that reacts with the hydroxyl groups on the substrate surface to enhance the adhesion of the water repellent.

[0070] The waterproofing effect of organic fluorine water repellents comes from the synergistic effect of "low surface energy" and "molecular film barrier". The specific mechanism is as follows: 1. Surface energy reduction effect (core mechanism): The bond energy of the fluorocarbon chain (CF bond energy is about 485kJ / mol) is much higher than that of the C-H bond (about 414kJ / mol), and the fluorine atom is extremely electronegative, resulting in weak intermolecular forces in the fluorocarbon chain and extremely low surface energy (about 10-15mN / m, much lower than the 72mN / m of water).

[0071] When the waterproofing agent is dispersed in the slurry and coated on the surface of the material, the fluorocarbon chains are arranged in a direction to form a hydrophobic interface, which increases the contact angle of water droplets (>90°) and makes it difficult to spread and penetrate, manifesting as a "lotus effect" (water droplets roll down and carry away pollutants).

[0072] 2. Molecular film barrier effect: Fluorocarbon polymers (such as fluorocarbon acrylate copolymers) form a dense film during the drying process, filling the micropores on the surface of the material and physically blocking water penetration.

[0073] If it contains a cross-linking agent, the waterproofing agent can react with the hydroxyl and amino groups on the surface of the substrate (such as polyurethane, glass fiber), enhance the adhesion of the film layer through chemical bonding, and improve the water resistance.

[0074] 3. Synergistic effect with nano titanium dioxide: Nano-titanium dioxide (2%-5%) added to the slurry can form a rough surface (similar to the micro-nano structure of lotus leaves), which, combined with the low surface energy of the fluorocarbon chain, produces a "roughness-surface energy synergistic hydrophobic effect", further improving the waterproof level (contact angle can reach more than 150°, super hydrophobic effect).

[0075] It is worth noting that due to the bioaccumulation of PFOS / PFOA, current mainstream products mostly use C6 / C4 short-chain fluorinated compounds (such as PFHxS, PFBS) or fluorine-free alternatives (such as silicone-based water-repellents), but organic fluorine compounds still dominate high-end fields (such as protective gloves and outdoor materials) due to their excellent performance.

[0076] Example 2: like Figures 2 to 11 As shown, in some preferred embodiments, the air flow layer formed at the impregnated portion 11 of the hand mold 1 is formed by the gas ejected from the pores 10 at the unimpregnated portion 12 of the hand mold 1 toward the impregnated portion 11 through rotation.

[0077] As a non-limiting embodiment of the hand mold 1, the hand mold 1 consists of a mold 2 and a rotating shaft 3. A planetary gear set 4 is provided inside the hand mold 1. Through the planetary gear set 4, the mold 2 and the rotating shaft 3 are set to rotate differentially relative to each other (that is, the rotation speed of the rotating shaft 3 is greater than the rotation speed of the mold 2). The rotating shaft 3 is swingably connected to the hanging chain conveyor and is driven to move by the hanging chain conveyor. The end of the rotating shaft 3 located inside the mold 2 is provided with a fan blade 31. The fan blade 31 rotates synchronously with the rotating shaft 3 to form an agitated gas to form an airflow, and the mold 2 is provided with a gas collection area 20 opposite the fan blade 31. After the airflow converges in the gas collection area 20, it is discharged outward through the gas flow channel 201 opened on the mold 2 to the corresponding air holes 10. When discharged, the gas flows along the axial direction of the mold toward the impregnation part 11. In conjunction with the self-rotation of the mold 2, the gas directly forms a flowing gas layer on the outer surface of the impregnation part 11.

[0078] As a non-limiting embodiment of the planetary gear set 4, the planetary gear 41 in the planetary gear set 4 is installed and connected by the end cover 21 provided on the unimpregnated end 12 of the mold 2. The end cover 21 covers the unimpregnated end 12 of the mold 2. A circle of limiting ring 121 is recessed inwardly on the unimpregnated end 12. A plurality of limiting pins 212 are passed through the flange 211 of the end cover 21 covering the limiting ring 121. The limiting pins 212 and the flange 211 are connected by threaded fitting, and a rolling ball is provided at the end of the limiting pin 212 that contacts the bottom of the groove of the limiting ring 121, so that the mold 2 is rotated relative to the end cover 21. The sun gear 42 is fitted with the rotating shaft 3 and connected by a keyway. The ring gear 43 is interference fit with the mold 2 and connected by a keyway. Specifically, when the rotating shaft 3 rotates, it first drives the sun gear 42 and the fan blades 31 to rotate, and the end cover 21 is in a circumferential fixed limit state at this time, that is, it has no rotational freedom. Therefore, the planetary gear 41 can only rotate around the mounting shaft 210 on the end cover 21, and cannot revolve around the sun gear 42. Through the transmission of the planetary gear 41, the ring gear 43 rotates, and driven by the ring gear 43, the mold 2 rotates with the ring gear 43, realizing the differential rotation structure of the mold 2 and the rotating shaft 3.

[0079] As a non-limiting embodiment of the end cover 21, the end cover 21 wraps around the rotating shaft 3 to form a guide wheel 214 and a limit block 215. The guide wheel 214 is a circular roller, and the limit block 215 is a square. A roller-shaped friction wheel 33 is provided on the rotating shaft 3. At the same time, along the moving path of the hand mold 1 during its self-rotation, a guide friction track 5 parallel to the moving path is laid, and the guide friction track 5 includes a guide part 51, a limiting part 52 and a friction part 53 arranged in parallel. The guide part 51 is arranged in rolling cooperation with the guide wheel 214 to guide the switching of the vertical-horizontal state of the hand mold 1. The limiting part 52 is arranged in sliding cooperation with the limiting block 215. Through the sliding cooperation between the limiting part 52 and the limiting block 215, the circumferential freedom of the end cover 21 is limited. The friction part 53 is arranged in rolling friction cooperation with the friction wheel 33, so that the rotating shaft 3 can achieve self-rotation through friction force.

[0080] It should be noted that when the chain conveyor drives the hand model 1 to move linearly, the swing angle of the hand model 1 depends on the angle of the rolling cooperation between the guide portion 51 and the guide wheel 214, that is, when the hand model 1 needs to be in a vertical state, the hinged portion of the rotating shaft 3 and the chain conveyor can be rotated and swung to a vertical state by the weight of the hand model 1 itself. When the hand model 1 is tilted upward and the hand model 1 is set at an angle of 30 degrees to the horizontal plane and the hand model 1 is rotated horizontally, both working states require the guide portion 51 to rotate and swing to a vertical state. The part 51 cooperates with the guide wheel 214. For example, the hand mold 1 is tilted upward to form an angle of 30° with the horizontal plane. At this time, the guide part 51 is set in a bent and twisted state, so that when the guide wheel 214 rolls along the guide part 51, the inclination angle of the hand mold 1 can be changed. The principle of switching the hand mold 1 from a vertical state to a horizontal state is also the effect caused by the change in the bending and twisting angle of the guide part 51. It should be emphasized here that in the path of the hand mold 1 in a non-rotating state, the limiting part 52 and the friction part 53 are not set under the path.

[0081] In addition, as a non-limiting embodiment of the fan blade 31, the fan blade 31 rotates with the rotating shaft 3, and introduces gas from the air inlet 200 opened on the end cover 21. The air inlet 200 is provided with a filter 201 for filtering the gas. The filter 201 filters impurities and dust in the air and retains the impurities and dust on the filter 201. Therefore, after the hand mold 1 completes one molding preparation of the polyurethane glove or completes a certain number of cycles of molding preparation of the polyurethane glove, the filter 201 needs to be flushed and washed with water to remove impurities and dust on the filter 201.

[0082] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing waterproof and breathable polyurethane gloves, characterized in that: The following steps are involved: Step a: After the inner liner is put on the hand form and adjusted to fit, the hand form with the inner liner is vertically placed in the coagulant tank for immersion. The hand form is lifted until the coagulant stops dripping, the hand form is swung to be transported horizontally, and the hand form rotates around its own central axis and placed in an oven at 50-60°C for 10-20 minutes; After drying in step b and step a, the hand mold is slowly and vertically placed into the polyurethane foam slurry tank for immersion, and then quickly lifted up, and the hand mold is tilted up to form an angle of 30° with the horizontal plane, and the hand mold is rotated around its own central axis for 5 minutes; After the rotation in step c and step b is completed, the hand mold is swung to be transported horizontally, and the hand mold rotates around its own central axis and enters the drying oven, and is heated at 90° C. for 20 minutes; After the hand molds in steps d and c are dried, they are slowly and vertically placed in a polyurethane slurry tank to be dipped in the second layer of slurry. After the dipping is completed, the hand mold is quickly lifted up and dripped with slurry for 3 minutes, then swung to a horizontal position for transportation, and rotated around its own central axis into an oven at 100-125°C for 20-30 minutes of drying. After drying in step e and step d, the hand mold is cooled to 30° C., vertically placed in a particle slurry tank to immerse the particle slurry. After dripping the slurry for 3 minutes, the hand mold is swung to be transported horizontally and rotated around its own central axis into an oven at 100-125° C. for 20-30 minutes to form a waterproof and breathable polyurethane glove. The waterproof and breathable polyurethane gloves formed in step f and step d are demoulded after cooling, trimmed, and then packaged; In the above steps a, b, c, d and e, when the hand mold rotates around its own central axis, an air flow layer surrounds the outer side of the immersed part of the hand mold.

2. The method for preparing waterproof and breathable polyurethane gloves according to claim 1, wherein: In the step a, before the hand mold is dipped into the coagulant, the lining is pre-treated with infrared rays, and the infrared rays have a wavelength range of 0.7 to 4.0 μm.

3. The method for preparing waterproof and breathable polyurethane gloves according to claim 1, wherein: In the step b, the polyurethane foaming slurry is based on a polyether polyurethane prepolymer, and the polyurethane foaming slurry also includes 5%-10% by mass of polyethylene glycol and 0.2%-0.5% by mass of an organosilicon modifier, the molecular weight of the polyethylene glycol is 2000-4000, and the organosilicon modifier is γ-aminopropyltriethoxysilane or its derivatives.

4. The method for preparing waterproof and breathable polyurethane gloves according to claim 1, wherein: In the step d, the second layer slurry is a core-shell structured polyurethane emulsion, the core layer is made of high-hardness isocyanate polyurethane, and the shell layer is made of flexible polyether polyurethane, and the mass ratio of the two is 3:7-5:

5.

5. The method for preparing waterproof and breathable polyurethane gloves according to claim 4, characterized in that: The preparation method of the core-shell polyurethane emulsion comprises the following steps: Step t1, preparation of core layer polyurethane prepolymer: add isocyanate type polyurethane prepolymer raw material to a four-necked flask equipped with a stirrer, thermometer and reflux condenser, start stirring, control the speed at 100-150r / min, raise the temperature to 80-85°C, slowly add measured acetone, stir evenly to fully dissolve the prepolymer, add chain extender ethylenediamine, control the reaction temperature at 80-85°C, react for 2-3h, stop the reaction, and obtain a core layer polyurethane prepolymer solution; Step t2, Preparation of Shell Polyurethane Prepolymer: Take another four-necked flask, add polyether polyurethane prepolymer raw material, and control the stirring speed at 100-150 r / min. Raise the temperature to 70-75°C, add acetone and stir to dissolve, then add the measured chain extender ethylenediamine, control the reaction temperature at 70-75°C, and react for 1.5-2 hours to obtain a shell polyurethane prepolymer solution; Step t3, preparing a core-shell emulsion, slowly adding the shell polyurethane prepolymer solution to the core polyurethane prepolymer solution while stirring, increasing the stirring speed to 200-250 r / min, and after uniform mixing, continuing stirring for 30 minutes, adding the compounded emulsifier to the above mixed solution, stirring for 15-20 minutes to fully emulsify the prepolymer, adding deionized water to the emulsion for dispersion, the amount of water added being 1-1.5 times the total mass of the polyurethane prepolymer, and stirring and dispersing at a high speed of 1000-1500 r / min for 30-40 minutes to form a stable emulsion, adding triethylamine for neutralization, adjusting the pH value of the emulsion to 7.5-8.5, stirring for 10-15 minutes, and removing acetone by reduced pressure distillation to obtain a core-shell polyurethane emulsion.

6. The method for preparing waterproof and breathable polyurethane gloves according to claim 1, wherein: In the step e, 2%-5% by mass of nano-titanium dioxide particles and 1%-2% by mass of a waterproofing agent are added to the particle slurry. The waterproofing agent is perfluorobutanesulfonic acid in the organic fluorine waterproofing agent.

7. The method for preparing waterproof and breathable polyurethane gloves according to claim 1, wherein: The air flow layer formed at the impregnated portion of the hand mold is formed by the rotation of the gas ejected from the pores at the unimpregnated portion of the hand mold toward the impregnated portion.

8. The method for preparing waterproof and breathable polyurethane gloves according to claim 7, characterized in that: The hand mold consists of a mold and a rotating shaft. A planetary gear set is arranged inside the hand mold. Through the planetary gear set, the mold and the rotating shaft are arranged to rotate relative to each other at a differential speed. The rotating shaft is swingably connected to the hanging chain conveyor and is driven to move by the hanging chain conveyor. A fan blade is provided at the end of the rotating shaft located inside the mold. The fan blade rotates synchronously with the rotating shaft to form an airflow, and the airflow is discharged outward through the air holes.

9. The method for preparing waterproof and breathable polyurethane gloves according to claim 8, characterized in that: The planetary gears in the planetary gear set are connected and installed through the end cover provided on the unimpregnated end of the mold. The end cover wraps the rotating shaft to form a guide wheel and a limit block. The guide wheel is a circular roller, the limit block is a square, and a roller-shaped friction wheel is provided on the rotating shaft. Along the moving path of the hand model during self-rotation, a guide friction track is laid parallel to the moving path. The guide friction track includes a guide part, a limiting part and a friction part which are arranged in parallel. The guide part is arranged in rolling cooperation with the guide wheel, the limiting part is arranged in sliding cooperation with the limiting block, and the friction part is arranged in rolling and friction cooperation with the friction wheel.

10. The method for preparing waterproof and breathable polyurethane gloves according to claim 9, characterized in that: The fan blades rotate along with the shaft, and gas is introduced from the air inlet holes opened on the end cover, and a filter screen is provided at the air inlet holes to filter the gas.

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