Waterproof and breathable shoe upper material and preparation method thereof

Abstract

This application discloses a waterproof and breathable shoe upper material and a preparation method thereof. The waterproof and breathable shoe upper material comprises a fabric textile layer, a waterproof and breathable functional layer, and a polyurethane foam layer, wherein the waterproof and breathable functional layer is located between the fabric textile layer and the polyurethane foam layer. The waterproof and breathable functional layer is a modified polytetrafluoroethylene microporous membrane, wherein the micropores of the modified polytetrafluoroethylene microporous membrane have a diameter of less than 2 μm. The surface of the modified polytetrafluoroethylene microporous membrane is grafted with polyacrylic acid segments. The modified polytetrafluoroethylene microporous membrane utilizes the principle that the diameter of a water molecule is larger than that of a water vapor molecule. The micropores contained in the modified polytetrafluoroethylene microporous membrane can accommodate water vapor and air diffusion through the pores, but larger water droplets cannot pass through, thus giving the shoe upper material excellent waterproof and breathable properties. In addition, the polyacrylic acid segments grafted onto the surface of the polytetrafluoroethylene microporous membrane can increase the surface energy of the polytetrafluoroethylene microporous membrane, facilitating composite bonding with other layers.

Description

Technical Field

[0001] The present application relates to the field of shoe upper materials, and in particular to a waterproof and breathable shoe upper material and a preparation method thereof. Background Art

[0002] Existing shoe upper materials, especially those for sports shoes, are gradually replacing leather with textile fabrics. Textile fabrics are light, soft, and have good breathability and ventilation properties, which can well meet the performance requirements of sports shoes. In addition, textile fabrics are low in cost compared to leather and can reduce energy consumption. They are a material with excellent performance and environmental protection.

[0003] The good air permeability of textile fabrics comes from their high porosity, which also allows rainwater and sewage to easily penetrate the upper, affecting the wearing experience. However, most of the waterproof sports shoes currently on the market are made of materials with low air permeability. During wearing, the feet are prone to sweating and difficult to expel, which seriously affects the wearing comfort. At the same time, a polytetrafluoroethylene microporous membrane was discovered and applied to waterproof and breathable clothing due to its special pore structure. However, as a shoe upper material, polytetrafluoroethylene has poor composite properties, low strength, and poor wear resistance. Therefore, the preparation of a shoe upper material with good waterproof, breathable and wear-resistant properties has important market prospects. Summary of the Invention

[0004] In order to solve the problem that the air permeability of the shoe upper material decreases when the waterproof performance is excellent, the present application provides a waterproof and breathable shoe upper material and a preparation method thereof.

[0005] In a first aspect, a waterproof and breathable shoe upper material comprises a fabric textile layer, a waterproof and breathable functional layer, and a polyurethane foam layer, wherein the waterproof and breathable functional layer is located between the fabric textile layer and the polyurethane foam layer; the waterproof and breathable functional layer is a modified polytetrafluoroethylene microporous membrane, and the diameter of the micropores on the modified polytetrafluoroethylene microporous membrane is less than 2 μm; the surface of the modified polytetrafluoroethylene microporous membrane is grafted with polyacrylic acid segments.

[0006] By adopting the above technical solution, the waterproof and breathable upper material in this application is a laminated composite fabric, wherein the fabric textile layer is mainly in direct contact with the human body, and its soft and breathable performance can be exchanged with the outside air in time, bringing out the sweat discharged by the human body, keeping the inside of the shoe dry and refreshing, and improving the wearing experience of the human body; the outer surface of the upper material is a polyurethane foam layer, and after the fabric textile layer is composited with the functional layer, the material is soft and not easy to shape, and it is not easy to form the same upper shape as the leather and polymer pressed upper. A layer of polyurethane foam layer is composited on the surface, which can improve the stiffness of the upper material and facilitate the subsequent production of various upper shapes; the pore structure of the polyurethane foam layer will not affect the waterproof and breathable performance of the waterproof and breathable functional layer in the upper material.

[0007] The middle layer of the shoe upper material of this application is a waterproof and breathable functional layer. This waterproof and breathable functional layer is a modified polytetrafluoroethylene microporous membrane. The polytetrafluoroethylene microporous membrane is a polymer film with a large number of small, interconnected micropores with a diameter of less than 2 μm. The polytetrafluoroethylene microporous membrane utilizes the principle that the diameter of water molecules is larger than that of water vapor molecules. This allows water vapor and air to diffuse through the pores, but larger water droplets cannot pass through the pores on the surface of the microporous membrane. This provides protection from the dampness and cold of wind, rain, and snow, while also providing breathability, preventing overheating and dampness during exercise. Furthermore, the polytetrafluoroethylene micropores are not straight channels, but rather form a network structure within the membrane. Wind cannot pass directly through, but redirects when encountering obstacles, achieving a windproof effect while also providing warmth.

[0008] However, the fluorine atoms contained in the polytetrafluoroethylene microporous membrane have high electronegativity, and its symmetrical structure also makes the attraction and surface energy between the polytetrafluoroethylene microporous membrane molecules low, and the composite performance is poor. In the composite process of the fabric textile layer and the polyurethane foam layer, the bonding performance is poor and the composite ability is weak. During use, the gaps between the layers are large and easy to slip, causing the upper material to lose its waterproof and breathable properties. Therefore, the polytetrafluoroethylene microporous membrane is modified, and polyacrylic acid segments are grafted on the surface of the modified polytetrafluoroethylene microporous membrane. The polar groups contained in the polyacrylic acid segments can eliminate the weak surface layers on the surface of the polytetrafluoroethylene microporous membrane, increase the bonding performance of the polytetrafluoroethylene microporous membrane, and improve the composite performance between the layers of the upper material, thereby obtaining a waterproof and breathable upper material with excellent performance.

[0009] Preferably, the modified polytetrafluoroethylene microporous membrane is prepared according to the following steps:

[0010] Step 1. Immersing the polytetrafluoroethylene microporous membrane in a strong oxidant, raising the temperature to 30-40°C, immersing for 1-2 hours, and then washing and drying; then immersing the dried polytetrafluoroethylene microporous membrane in a chitosan acetic acid solution at room temperature for 6-8 hours to obtain a pretreated polytetrafluoroethylene microporous membrane;

[0011] Step 2: Immerse the obtained pretreated polytetrafluoroethylene microporous membrane in an acrylic acid aqueous solution, raise the temperature to 55-60° C., add an initiator, react for 50-60 minutes, and then wash and dry to obtain a modified polytetrafluoroethylene microporous membrane.

[0012] Preferably, the strong oxidant includes one or a combination of potassium permanganate and sodium permanganate; and the initiator includes one or a combination of ammonium persulfate, potassium persulfate and sodium persulfate.

[0013] Preferably, the mass fraction of the chitosan acetic acid solution is 1-2%, and the mass volume ratio of the polytetrafluoroethylene microporous membrane to the chitosan acetic acid solution is 1 g: (5-7) ml.

[0014] Preferably, the mass fraction of acrylic acid in the acrylic acid aqueous solution is 20-25%; the mass volume ratio of the pretreated polytetrafluoroethylene microporous membrane to the acrylic acid aqueous solution is 1 g: (1.5-2.5) ml.

[0015] Preferably, the mass of the initiator is 1.5-3% of the mass of the acrylic acid aqueous solution.

[0016] By adopting the above technical solution, the surface energy of the polytetrafluoroethylene microporous membrane is low, and general solid materials are difficult to adsorb on its surface. Therefore, the polytetrafluoroethylene microporous membrane needs to be modified. First, the polytetrafluoroethylene microporous membrane is surface treated with a strong oxidant to increase the active adsorption sites on the surface of the polytetrafluoroethylene microporous membrane, thereby improving the adsorption capacity of chitosan.

[0017] Chitosan molecular chains contain multiple polar groups, which can be adsorbed on the surface of polytetrafluoroethylene microporous membranes through electrostatic adsorption and intermolecular forces. Its long molecular chains can also penetrate into the pores of the membrane, forming a strong adsorption effect. At the same time, chitosan has a semi-rigid structure, which can modify the poor strength of polytetrafluoroethylene microporous membranes to a certain extent, while also maintaining good flexibility and improving permeability. The polar groups contained in chitosan also allow the modified polytetrafluoroethylene microporous membrane to still have good air permeability and moisture permeability, allowing for good exchange between the skin and the outside air. The polysaccharide structure also enables chitosan to absorb large amounts of water, forming a semi-gel structure, which hinders heat conduction and has a thermal insulation effect.

[0018] Chitosan is deposited and adsorbed on the surface of the pretreated PTFE microporous membrane. Acrylic acid monomers, under the action of an initiator, polymerize to form polyacrylic acid. On the one hand, polar groups such as hydroxyl groups in chitosan react with acrylic acid to form links, allowing other acrylic acid monomers to gradually form polyacrylates based on this core, which are then grafted onto the surface of the PTFE microporous membrane to produce a modified PTFE microporous membrane. On the other hand, the molecular chains of chitosan and polyacrylate become entangled, forming a cross-linked structure, further enhancing the strength of the PTFE and preventing the grafted polyacrylate from easily peeling off. The polyacrylic acid chain segments contain a large number of carboxyl groups, which can form a good composite structure with the polyurethane foam layer. During the film formation process of the polyurethane foam layer, the isocyanate groups in the foaming slurry react with the carboxyl groups on the surface of the modified PTFE microporous membrane, forming a chemical connection between the polyurethane foaming agent and the PTFE microporous membrane. This ensures strong adhesion between the layers and prevents peeling of the polyurethane foam layer.

[0019] The amount of initiator used in the above-mentioned polymerization reaction needs to be strictly controlled. When the amount of initiator used is small, the active centers of the polymerization reaction are small and the polymerization reaction is slow; when the amount of initiator used is too much, the kinetic chain length or degree of polymerization will be reduced, resulting in a decrease in the molecular weight of the polymer, which will have an adverse effect on the obtained modified polytetrafluoroethylene microporous membrane.

[0020] Preferably, the isocyanate index of the polyurethane foam layer is 1.5 to 1.8.

[0021] By adopting the above technical solution, the isocyanate index is an important characterization index of polyurethane materials. In the present application, the range of the isocyanate index can maintain the polyurethane slurry in a stable state, prevent rapid crosslinking, and maintain good film-forming properties while also having good mechanical properties. When the isocyanate index is low, the mechanical properties of the resulting polyurethane foam layer are significantly reduced, and the stability is poor. When the isocyanate index is too high, the interaction within the molecule is significantly enhanced, and the number of urea bonds synthesized is significantly increased, resulting in a decrease in the mechanical properties and stability of the resulting polyurethane foam layer.

[0022] Preferably, the fabric textile layer comprises one or a combination of ultrafine polyester, nylon and polyester / nylon blended fabrics with a warp density of 260 to 400 yarns / 10 cm.

[0023] By adopting the above-mentioned technical solution, in addition to adding a waterproof and breathable functional layer, the present application has a high transverse and longitudinal density of the fabric textile layer, and the structure of the fabric textile layer formed is relatively stable and strong, which can play a certain supporting role in the upper material, and can create a certain gap between the waterproof and breathable functional layer and the skin, further reducing the wear of polar substances on the surface of the waterproof and breathable functional layer, and avoiding the clogging of the micropores of the waterproof and breathable functional layer.

[0024] In a second aspect, the present application also provides a method for preparing a waterproof and breathable shoe upper material, which is prepared according to the following method:

[0025] S1. The dried and dehydrated polyethylene glycol and diphenylmethane diisocyanate were stirred and mixed at 75-85°C for 1.5-2.5h, and then a chain extender was added and stirred for 0.5-1h; after stirring and mixing, the solution temperature was lowered to 30-40°C, an amine catalyst and a deionized hydrazine hydrate solution were added in sequence and stirred and mixed, and the solution temperature was adjusted to room temperature, a latex foaming agent was added, and stirred and mixed for 10-20min to obtain a foaming slurry;

[0026] S2. The surface of the fabric textile layer is coated with a layer of adhesive, and the modified polytetrafluoroethylene microporous membrane is composited by a pressure roller at 70 to 80 ° C to obtain a composite membrane;

[0027] S3. The surface of the modified polytetrafluoroethylene microporous membrane of the obtained composite membrane is evenly coated with the foaming slurry obtained in step S1, and the film is left at room temperature for 45 to 50 hours, and then dried to obtain a waterproof and breathable shoe upper material.

[0028] Preferably, the chain extender in the foaming slurry includes one or a combination of 2,2-dihydroxymethylbutanoic acid, 1,4-butanediol, and 1,2-propylene glycol.

[0029] Preferably, the amine catalyst in the foaming slurry includes one or a combination of triethylamine, N,N-dimethylcyclohexylamine, and triethylenediamine.

[0030] Preferably, the latex foaming agent in the foaming slurry includes one or a combination of ammonium stearate and potassium stearate.

[0031] Preferably, the adhesive in step S2 includes one or a combination of polyamide hot melt adhesive and polyurethane hot melt adhesive.

[0032] In the above steps, a polyurethane foaming slurry is first prepared according to the isocyanate index. The slurry can maintain stable properties. After being coated on the surface of the modified polytetrafluoroethylene microporous membrane, it will gradually form a film to form a polyurethane foam layer, thereby obtaining a shoe upper material with a three-layer structure. In addition, since the foaming slurry reacts on the surface of the modified polytetrafluoroethylene microporous membrane to form a film and reacts with the active groups on the surface of the modified polytetrafluoroethylene microporous membrane, the material has good bonding performance and is not easy to peel off.

[0033] Preferably, in the step S1, hydroxy-terminated polydimethylsiloxane is further added during the stirring of polyethylene glycol and diphenylmethane diisocyanate; the amount of the hydroxy-terminated polydimethylsiloxane added is 8-12% of the total amount of polyethylene glycol and diphenylmethane diisocyanate added.

[0034] By adopting the above technical solution, since the polyurethane foam layer is in the outer layer of the upper material, it is greatly affected by the environment, and the polyurethane foam material is more sensitive to temperature, and the glass transition temperature is higher. When the temperature is low, the activity of the polyurethane molecules decreases, and the performance decreases significantly. The modified polytetrafluoroethylene microporous membrane of the inner layer has good temperature resistance, and the polyurethane foam layer shrinks when the temperature is low, which will cause the overall performance to decrease. Therefore, terminal hydroxyl polydimethylsiloxane is also added to the foaming slurry of the polyurethane foam layer. The hydroxyl group contained in the terminal hydroxyl polydimethylsiloxane can also react with the isocyanate group in the isocyanate, and can be combined with each other. The long molecular chain structure increases the flexibility of the polyurethane molecular chain, reduces the glass transition temperature, and then reduces the temperature sensitivity of the polyurethane foam layer. At the same time, the siloxane segment in the terminal hydroxyl polydimethylsiloxane can increase the hydrophobicity of the polyurethane foam layer, improve the stain resistance of the polyurethane foam layer as the outer surface of the upper, make the upper easy to clean, and improve the user experience.

[0035] In summary, this application has the following beneficial effects:

[0036] 1. The shoe upper material of the present application adopts a laminated composite structure, and the middle layer is a waterproof and breathable functional layer, which mainly adopts a modified polytetrafluoroethylene microporous membrane. It can use the principle that the diameter of water molecules is larger than the diameter of water vapor molecules. The micropores contained can accommodate water vapor and air to diffuse through the holes, but water droplets with larger diameters cannot pass through. This can not only resist the dampness and coldness of wind, rain, and snow, but also has breathability, so that people will not overheat or get wet during exercise. However, the surface energy of the polytetrafluoroethylene microporous membrane is low, and the bonding performance with other layers is poor, so it needs to be modified. The polar groups contained in the polyacrylic acid chain segment can increase the bonding performance between the polytetrafluoroethylene microporous membrane and other layers.

[0037] 2. During the modification process of the polytetrafluoroethylene microporous membrane, chitosan is also deposited and adsorbed on the surface. Chitosan can be adsorbed on the surface of the polytetrafluoroethylene microporous membrane through electrostatic adsorption and intermolecular forces. The semi-rigid structure of chitosan increases the strength of the polytetrafluoroethylene microporous membrane while maintaining the softness of the polytetrafluoroethylene microporous membrane, and at the same time will not affect the air permeability and thermal insulation of the polytetrafluoroethylene microporous membrane.

[0038] 3. End-hydroxy polydimethylsiloxane can also be added to the polyurethane foam layer during the preparation process. The long molecular chain structure increases the flexibility of the polyurethane molecular chain, reduces the glass transition temperature, and thus reduces the temperature sensitivity of the polyurethane foam layer. The performance will not be affected at low temperatures. At the same time, the silicone chain segment can increase the hydrophobicity of the polyurethane foam layer and improve the stain resistance of the polyurethane foam layer as the outer surface of the shoe upper. DETAILED DESCRIPTION

[0039] Preparation example of modified polytetrafluoroethylene microporous membrane

[0040] Preparation Example 1: A modified polytetrafluoroethylene microporous membrane was prepared according to the following method:

[0041] 100 g of a polytetrafluoroethylene microporous membrane (pore diameter of 0.1 μm to 0.5 μm) was immersed in 250 ml of a 1% potassium permanganate solution, the temperature was raised to 30° C., and the membrane was immersed for 1.5 hours, followed by washing and drying. The dried polytetrafluoroethylene microporous membrane was further immersed in 600 ml of a 1% chitosan acetic acid solution (wherein the degree of deacetylation of chitosan was 80%) at room temperature for 6 hours to obtain a pretreated polytetrafluoroethylene microporous membrane.

[0042] 100 g of the obtained pretreated polytetrafluoroethylene microporous membrane was immersed in 200 ml of a 20% by mass acrylic acid aqueous solution, the temperature was raised to 60° C., 4 g of ammonium persulfate was added, the reaction was carried out for 60 min, and then the modified polytetrafluoroethylene microporous membrane was obtained after washing and drying.

[0043] Preparation Example 2, a modified polytetrafluoroethylene microporous membrane, is different from Preparation Example 1 only in that the amount of chitosan acetic acid solution with a mass fraction of 1% is 500 ml.

[0044] Preparation Example 3, a modified polytetrafluoroethylene microporous membrane, is different from Preparation Example 1 only in that the amount of chitosan acetic acid solution with a mass fraction of 1% is 700 ml.

[0045] Preparation Example 4, a modified polytetrafluoroethylene microporous membrane, is different from Preparation Example 1 only in that the amount of the added acrylic acid aqueous solution with a mass fraction of 20% is 150 ml.

[0046] Preparation Example 5, a modified polytetrafluoroethylene microporous membrane, is different from Preparation Example 1 only in that the amount of the added acrylic acid aqueous solution with a mass fraction of 20% is 300 ml.

[0047] Preparation Example 6, a modified polytetrafluoroethylene microporous membrane, is different from Preparation Example 1 only in that the amount of ammonium persulfate added is 3 g.

[0048] Preparation Example 7, a modified polytetrafluoroethylene microporous membrane, is different from Preparation Example 1 only in that the amount of ammonium persulfate added is 6 g.

[0049] Preparation Example 8, a modified polytetrafluoroethylene microporous membrane, is different from Preparation Example 1 only in that the amount of chitosan acetic acid solution with a mass fraction of 1% is 400 ml.

[0050] Preparation Example 9, a modified polytetrafluoroethylene microporous membrane, is different from Preparation Example 1 only in that the amount of chitosan acetic acid solution with a mass fraction of 1% is 800 ml.

[0051] Preparation Example 10, a modified polytetrafluoroethylene microporous membrane, is different from Preparation Example 1 only in that the amount of ammonium persulfate added is 2 g.

[0052] Preparation Example 11, a modified polytetrafluoroethylene microporous membrane, is different from Preparation Example 1 only in that the amount of ammonium persulfate added is 8 g.

[0053] Preparation Example 12: A modified polytetrafluoroethylene microporous membrane was prepared according to the following method:

[0054] 100 g of polytetrafluoroethylene microporous membrane (micropore diameter of 0.1 μm to 0.5 μm) was immersed in 600 ml of 1% chitosan acetic acid solution (wherein the deacetylation degree of chitosan was 80%) at room temperature for 6 h to obtain a pretreated polytetrafluoroethylene microporous membrane;

[0055] 100 g of the obtained pretreated polytetrafluoroethylene microporous membrane was immersed in 200 ml of a 20% by mass acrylic acid aqueous solution, the temperature was raised to 60° C., 4 g of ammonium persulfate was added, the reaction was carried out for 60 min, and then the modified polytetrafluoroethylene microporous membrane was obtained after washing and drying.

[0056] Preparation Example 13: A modified polytetrafluoroethylene microporous membrane was prepared according to the following method:

[0057] 100 g of polytetrafluoroethylene microporous membrane (micropore diameter of 0.1 μm to 0.5 μm) was immersed in 250 ml of 1% potassium permanganate solution, the temperature was raised to 30° C., and the membrane was immersed for 1.5 hours, followed by washing and drying. The dried polytetrafluoroethylene microporous membrane was further immersed in 600 ml of 1% chitosan acetic acid solution (wherein the deacetylation degree of chitosan was 80%) at room temperature for 6 hours, and then washed and dried to obtain a modified polytetrafluoroethylene microporous membrane.

[0058] Example

[0059] Example 1, a waterproof and breathable shoe upper material, is prepared according to the following method:

[0060] 1000 g of polyethylene glycol-2000, 213 g of diphenylmethane diisocyanate, and 120 g of hydroxy-terminated polydimethylsiloxane (average molecular weight of 4500) were dried and dehydrated, and then stirred and mixed at 80° C. for 2 h. 26.5 g of 2,2-dimethylolbutyric acid was added, and stirring was continued for 0.5 h. After stirring and mixing, the solution temperature was lowered to 35° C., 4 g of triethylamine and 1200 g of a deionized hydrazine hydrate solution were added in sequence, stirred and mixed, and the solution temperature was adjusted to room temperature. 72.5 g of stearamide was added, and stirring and mixing was carried out for 20 min to obtain a foaming slurry (wherein the isocyanate index was 1.7);

[0061] A layer of polyamide hot melt adhesive (viscosity of 5000-8000 cps / 180°C) was coated on the surface of a fabric textile layer (a polyester / nylon blended fabric with an average warp density of 320 yarns / 10 cm) and composited with the modified polytetrafluoroethylene microporous membrane prepared in Preparation Example 1 by a pressing roller at 80°C to obtain a composite membrane;

[0062] A layer of foaming slurry is evenly coated on the surface of the modified polytetrafluoroethylene microporous membrane of the obtained composite membrane, and the membrane is left at room temperature for 48 hours to form a film, and then dried to obtain a waterproof and breathable shoe upper material.

[0063] Example 2, a waterproof and breathable shoe upper material, differs from Example 1 only in that the isocyanate index in the foaming slurry is 1.5 and the added amount of diphenylmethane diisocyanate is 187.5 g.

[0064] Example 3, a waterproof and breathable shoe upper material, differs from Example 1 only in that the isocyanate index in the foaming slurry is 1.8 and the added amount of diphenylmethane diisocyanate is 225 g.

[0065] Example 4, a waterproof and breathable shoe upper material, is different from Example 1 only in that the added amount of hydroxyl-terminated polydimethylsiloxane is 97 g.

[0066] Example 5, a waterproof and breathable shoe upper material, differs from Example 1 only in that the added amount of hydroxyl-terminated polydimethylsiloxane is 145.5 g.

[0067] Example 6, a waterproof and breathable shoe upper material, is different from Example 1 only in that the modified polytetrafluoroethylene microporous membrane prepared in Preparation Example 1 is replaced by an equal amount of the modified polytetrafluoroethylene microporous membrane prepared in Preparation Example 2.

[0068] Example 7, a waterproof and breathable shoe upper material, is different from Example 1 only in that the modified polytetrafluoroethylene microporous membrane prepared in Preparation Example 1 is replaced by an equal amount of the modified polytetrafluoroethylene microporous membrane prepared in Preparation Example 3.

[0069] Example 8, a waterproof and breathable shoe upper material, is different from Example 1 only in that the modified polytetrafluoroethylene microporous membrane prepared in Preparation Example 1 is replaced by an equal amount of the modified polytetrafluoroethylene microporous membrane prepared in Preparation Example 4.

[0070] Example 9, a waterproof and breathable shoe upper material, is different from Example 1 only in that the modified polytetrafluoroethylene microporous membrane prepared in Preparation Example 1 is replaced by an equal amount of the modified polytetrafluoroethylene microporous membrane prepared in Preparation Example 5.

[0071] Example 10, a waterproof and breathable shoe upper material, is different from Example 1 only in that the modified polytetrafluoroethylene microporous membrane prepared in Preparation Example 1 is replaced by an equal amount of the modified polytetrafluoroethylene microporous membrane prepared in Preparation Example 6.

[0072] Example 11, a waterproof and breathable shoe upper material, is different from Example 1 only in that the modified polytetrafluoroethylene microporous membrane prepared in Preparation Example 1 is replaced by an equal amount of the modified polytetrafluoroethylene microporous membrane prepared in Preparation Example 7.

[0073] Example 12, a waterproof and breathable shoe upper material, is different from Example 1 only in that the modified polytetrafluoroethylene microporous membrane prepared in Preparation Example 1 is replaced by an equal amount of the modified polytetrafluoroethylene microporous membrane prepared in Preparation Example 8.

[0074] Example 13, a waterproof and breathable shoe upper material, is different from Example 1 only in that the modified polytetrafluoroethylene microporous membrane prepared in Preparation Example 1 is replaced by an equal amount of the modified polytetrafluoroethylene microporous membrane prepared in Preparation Example 9.

[0075] Example 14, a waterproof and breathable shoe upper material, is different from Example 1 only in that the modified polytetrafluoroethylene microporous membrane prepared in Preparation Example 1 is replaced by an equal amount of the modified polytetrafluoroethylene microporous membrane prepared in Preparation Example 10.

[0076] Example 15, a waterproof and breathable shoe upper material, differs from Example 1 only in that the modified polytetrafluoroethylene microporous membrane prepared in Preparation Example 1 is replaced by an equal amount of the modified polytetrafluoroethylene microporous membrane prepared in Preparation Example 11.

[0077] Example 16, a waterproof and breathable shoe upper material, is different from Example 1 only in that the modified polytetrafluoroethylene microporous membrane prepared in Preparation Example 1 is replaced by an equal amount of the modified polytetrafluoroethylene microporous membrane prepared in Preparation Example 12.

[0078] Example 17, a waterproof and breathable shoe upper material, differs from Example 1 only in that no hydroxy-terminated polydimethylsiloxane is added to the foaming slurry.

[0079] Comparative Example

[0080] Comparative Example 1 is a waterproof and breathable shoe upper material, which differs from Example 1 only in that the modified polytetrafluoroethylene microporous membrane prepared in Preparation Example 1 is replaced by an equal amount of the modified polytetrafluoroethylene microporous membrane prepared in Preparation Example 13.

[0081] Comparative Example 2 is a waterproof and breathable shoe upper material, which is different from Example 1 only in that the modified polytetrafluoroethylene microporous membrane prepared in Preparation Example 1 is replaced by an equal amount of unmodified polytetrafluoroethylene microporous membrane.

[0082] Comparative Example 3, a waterproof and breathable shoe upper material, differs from Example 1 only in that the isocyanate index in the foaming slurry is 1.3 and the added amount of diphenylmethane diisocyanate is 162.5 g.

[0083] Comparative Example 4, a waterproof and breathable shoe upper material, differs from Example 1 only in that the isocyanate index in the foaming slurry is 1.9 and the added amount of diphenylmethane diisocyanate is 237.5 g.

[0084] Performance testing

[0085] 1. Air permeability test: According to GB / T 5453-1997 “Determination of Air Permeability of Textile Fabrics”, the air permeability of the upper materials obtained in the examples and comparative examples was tested.

[0086] 2. Moisture permeability test: The moisture permeability of the upper materials obtained in the examples and comparative examples was tested according to GB / T 12704.2-2009 “Test method for water vapor permeability of textile fabrics - Part 2: Evaporation method”.

[0087] 3. Waterproof performance test: According to GB / T 4744-2013 "Testing and evaluating the waterproof performance of textiles - Hydrostatic pressure method", the hydrostatic pressure resistance of the upper materials obtained in the examples and comparative examples was tested to characterize the waterproof performance of the materials. The grades are ranked from 1 to 5, with 5 being the highest. The higher the grade, the better the waterproofness.

[0088] 4. Interlayer Adhesion Test: The peel strength of the upper materials obtained in the Examples and Comparative Examples was tested according to FZ / T 01010-2012, "Determination of Peel Strength of Coated Fabrics," to characterize the interlayer adhesion. The peel strength of the upper materials was then tested again at 0°C.

[0089] The test results are shown in Table 1:

[0090] Table 1 Test results of upper material performance

[0091]

[0092] According to Table 1, in combination with Examples 1 and 2-5, it can be seen that the air permeability, moisture permeability, hydrostatic pressure resistance, and interlayer peel strength at different temperatures of Examples 2-5 do not change significantly compared to Example 1. The interlayer peel strength of Examples 4 and 5 varies significantly at different temperatures, with a slight decrease in peel strength at 0°C, indicating that the various properties of Examples 2-5 do not change much compared to Example 1. This may be because the only difference between Examples 2-5 and Example 1 is that the isocyanate index and the amount of hydroxyl-terminated polydimethylsiloxane added during the preparation of the foaming slurry vary within the claimed range. The performance changes between Examples 4 and 5 may be due to the reduction or increase in the amount of hydroxyl-terminated polydimethylsiloxane added. When the amount of hydroxyl-terminated polydimethylsiloxane is reduced, the effect on the glass transition temperature is reduced, while when the amount of hydroxyl-terminated polydimethylsiloxane is increased, the hydrophobicity of the material increases, which reduces the bonding performance between the modified polytetrafluoroethylene microporous membrane and the modified polytetrafluoroethylene microporous membrane.

[0093] Combining Example 1 with Examples 6 through 11, it can be seen that the air permeability, moisture permeability, hydrostatic pressure resistance, and interlayer peel strength at different temperatures of Examples 6 through 11 do not vary significantly compared to Example 1, indicating that the various properties of Examples 6 through 11 do not vary significantly compared to Example 1. This may be because the only difference between Examples 6 through 11 and Example 1 is that the ratio of the added raw materials in the preparation of the modified polytetrafluoroethylene microporous membranes varies within the scope of the claims.

[0094] Combining Examples 1, 12, and 13, it can be seen that the air permeability, moisture permeability, hydrostatic pressure resistance, and interlayer peel strength at different temperatures of Examples 12 and 13 decreased compared to those of Example 1, indicating that the various properties of Examples 12 and 13 decreased compared to those of Example 1. This may be due to the adjustment of the amount of chitosan added to the modified polytetrafluoroethylene microporous membranes used in Examples 12 and 13 during the preparation process. The reduced amount of chitosan added in Example 12 resulted in a decrease in the subsequent grafting rate of the polyacrylic acid segments, decreased bonding performance, and a partial loss of chitosan function, resulting in a decrease in the air and moisture permeability of the upper material. The increased amount of chitosan added in Example 13 may have caused excessive chitosan to clog the micropores in the modified polytetrafluoroethylene microporous membrane, resulting in a decrease in the air and moisture permeability of the upper material.

[0095] Combining Examples 1, 14, and 15, it can be seen that the air permeability, moisture permeability, hydrostatic pressure resistance, and interlayer peel strength at different temperatures of Examples 14 and 15 decreased compared to those of Example 1, indicating that the various properties of Examples 14 and 15 decreased compared to those of Example 1. This may be due to adjustments in the amount of initiator ammonium persulfate added during the preparation of the modified polytetrafluoroethylene microporous membranes used in Examples 14 and 15. In Example 14, the reduced amount of ammonium persulfate resulted in fewer active centers for the polymerization reaction, slowing the polymerization reaction, reducing the grafting rate of the polyacrylic acid segments, and deteriorating the adhesive properties. In Example 15, the increased amount of ammonium persulfate added reduced the kinetic chain length or degree of polymerization, resulting in a decrease in polymer molecular weight and, similarly, in the performance of the resulting upper material.

[0096] Combining Examples 1 and 16, it can be seen that the air permeability, moisture permeability, hydrostatic pressure resistance, and interlayer peel strength at different temperatures of Example 16 decreased compared to those of Example 1, indicating that the various properties of Example 16 were reduced compared to those of Example 1. This may be because the modified polytetrafluoroethylene microporous membrane used in Example 16 was not modified with potassium permanganate during the preparation process, resulting in a decrease in surface adsorption sites and the amount of chitosan adsorbed, which in turn led to a decrease in the adhesive properties of the modified polytetrafluoroethylene microporous membrane.

[0097] Combining Examples 1 and 17, it can be seen that the air permeability, moisture permeability, hydrostatic pressure resistance, and interlayer peel strength at different temperatures of Example 17 decreased compared to those of Example 1. The peel strength at 0°C decreased significantly, indicating that the various properties of Example 17 were reduced compared to those of Example 1. This may be because no hydroxyl-terminated polydimethylsiloxane was added to the foaming slurry during the preparation of Example 17, resulting in the polyurethane foam layer being sensitive to temperature and experiencing a decrease in performance as the temperature decreases.

[0098] Combining Example 1, Comparative Example 1, and Comparative Example 2, it can be seen that the air permeability, moisture permeability, hydrostatic pressure resistance, and interlayer peel strength at different temperatures of Comparative Examples 1 and 2 have significantly decreased compared to Example 1, with the decrease in Comparative Example 2 being more significant, indicating that the various properties of Comparative Examples 1 and 2 have been significantly reduced compared to Example 1. This may be because the modified polytetrafluoroethylene microporous membrane used in Comparative Example 1 did not contain acrylic acid during the preparation process, and no polyacrylic acid segments were grafted onto the surface of the polytetrafluoroethylene microporous membrane. This significantly reduced hydrophilicity compared to Example 1, resulting in a significant decrease in adhesive properties. Furthermore, in Comparative Example 2, the polytetrafluoroethylene microporous membrane was not hydrophilically modified. In addition to being unable to form a composite with the other two layers, the loss of the synergistic effect of chitosan also significantly reduced air and moisture permeability.

[0099] Combining Example 1, Comparative Examples 3, and 4, it can be seen that the air permeability, moisture permeability, hydrostatic pressure resistance, and interlayer peel strength at different temperatures of Comparative Examples 3 and 4 show significant decreases compared to Example 1, indicating that the various performances of Comparative Examples 3 and 4 are significantly reduced compared to Example 1. This may be due to the low isocyanate index of the foaming slurry in Comparative Example 3, which significantly degrades the physical properties of the polyurethane foam layer and, in turn, the significant performance degradation of the upper material; and the excessively high isocyanate index of the foaming slurry in Comparative Example 4, which slows film formation and results in a highly rigid polyurethane foam layer with reduced performance.

[0100] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A waterproof and breathable shoe upper material, comprising a fabric textile layer, a waterproof and breathable functional layer and a polyurethane foam layer, characterized in that: The waterproof and breathable functional layer is located between the fabric textile layer and the polyurethane foam layer; the waterproof and breathable functional layer is a modified polytetrafluoroethylene microporous membrane, the micropore diameter of the modified polytetrafluoroethylene microporous membrane is less than 2 μm; the surface of the modified polytetrafluoroethylene microporous membrane is grafted with polyacrylic acid segments; The modified polytetrafluoroethylene microporous membrane is prepared according to the following steps: Step 1. Immerse the polytetrafluoroethylene microporous membrane in a strong oxidant, raise the temperature to 30-40°C, immerse for 1-2 hours, and then wash and dry. Then, immerse the dried polytetrafluoroethylene microporous membrane in a chitosan acetic acid solution at room temperature for 6-8 hours to obtain a pretreated polytetrafluoroethylene microporous membrane. Step 2. Immersing the obtained pretreated polytetrafluoroethylene microporous membrane in an acrylic acid aqueous solution, raising the temperature to 55-60° C., adding an initiator, reacting for 50-60 minutes, and then washing and drying to obtain a modified polytetrafluoroethylene microporous membrane; The isocyanate index of the polyurethane foam layer is 1.5 to 1.

8.

2. The waterproof and breathable shoe upper material according to claim 1, characterized in that: The strong oxidant includes one or a combination of potassium permanganate and sodium permanganate; the initiator includes one or a combination of ammonium persulfate, potassium persulfate and sodium persulfate.

3. The waterproof and breathable shoe upper material according to claim 1, characterized in that: The mass fraction of the chitosan acetic acid solution is 1-2%, and the mass volume ratio of the polytetrafluoroethylene microporous membrane to the chitosan acetic acid solution is 1g: (5-7)ml.

4. The waterproof and breathable shoe upper material according to claim 1, characterized in that: The mass fraction of acrylic acid in the acrylic acid aqueous solution is 20-25%; the mass volume ratio of the pretreated polytetrafluoroethylene microporous membrane to the acrylic acid aqueous solution is 1g: (1.5-2.5)ml.

5. The waterproof and breathable shoe upper material according to claim 1, characterized in that: The mass of the initiator is 1.5-3% of the mass of the acrylic acid aqueous solution.

6. The waterproof and breathable shoe upper material according to claim 1, characterized in that: The fabric textile layer comprises one or a combination of ultra-fine polyester, nylon and polyester / nylon blended fabrics with a warp density of 260 to 400 yarns / 10 cm.

7. The method for preparing a waterproof and breathable shoe upper material according to any one of claims 1 to 6, characterized in that: Prepared according to the following method: S1. The dried and dehydrated polyethylene glycol and diphenylmethane diisocyanate were stirred and mixed at 75-85°C for 1.5-2.5h, and then a chain extender was added and stirred for 0.5-1h; after stirring and mixing, the solution temperature was lowered to 30-40°C, an amine catalyst and a deionized hydrazine hydrate solution were added in sequence and stirred, and the solution temperature was adjusted to room temperature, a foaming agent was added, and stirred and mixed for 10-20min to obtain a foaming slurry; S2. The surface of the fabric textile layer is coated with a layer of adhesive, and the modified polytetrafluoroethylene microporous membrane is composited by a pressure roller at 70 to 80 ° C to obtain a composite membrane; S3. The surface of the modified polytetrafluoroethylene microporous membrane of the obtained composite membrane is evenly coated with the foaming slurry obtained in step S1, and the film is left at room temperature for 45 to 50 hours, and then dried to obtain a waterproof and breathable shoe upper material.

8. The method for preparing the waterproof and breathable shoe upper material according to claim 7, characterized in that: In the step S1, hydroxy-terminated polydimethylsiloxane is further added during the stirring of polyethylene glycol and diphenylmethane diisocyanate; the amount of the hydroxy-terminated polydimethylsiloxane added is 8-12% of the total amount of polyethylene glycol and diphenylmethane diisocyanate added.

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