A porogen and its use, an antibacterial, breathable film and a method for its preparation

Abstract

The application discloses a pore-forming agent, which comprises a core material and a skin layer coated on the surface of the core material, wherein the core material is a copper sulfate crystal hydrate, and the skin layer is a non-polar substance with a melting point of less than or equal to 120 DEG C. The application further discloses a preparation method of the pore-forming agent and an application of the pore-forming agent in a breathable film. The application further discloses an antibacterial breathable film, which comprises resin and the pore-forming agent. The application further discloses a preparation method of the antibacterial breathable film, which comprises the following steps: mixing and granulating the resin and the pore-forming agent, casting a film, stretching, and shaping to obtain the antibacterial breathable film, wherein microwave heating is performed simultaneously with the stretching. The pore-forming agent is obtained by selecting the copper sulfate crystal hydrate as the core material and coating the core material with the skin layer, and the pore-forming agent, in combination with the microwave heating, can make the antibacterial breathable film have uniform pores and has a sterilization effect; and the preparation method of the pore-forming agent and the breathable film is simple and suitable for industrial production.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of porogen, in particular to a porogen and application thereof, an antibacterial breathable film and a preparation method thereof. BACKGROUND

[0002] The breathable film is a kind of microporous film allowing water vapor to diffuse through but blocking liquid water from leaking, mainly used for manufacturing hygiene protection products and rainproof cloth products, and widely used in the fields of medical health, personal care, building, and agricultural and sideline product packaging.

[0003] At present, the porogen of the breathable film is superfine calcium carbonate. The processing difficulty of the index parameters of the superfine calcium carbonate porogen is large, resulting in high production cost. In the preparation process of the breathable film, the particle size and distribution performance of the calcium carbonate directly affect the processing fluidity, and further determine the production speed and process stability of the breathable film, and also have important influence on the tensile pore-forming property, pore structure, air permeability and mechanical property of the breathable film: (1) if the particle size is too small, the dispersibility is poor, and the oil absorption value is high, which causes unstable quality of the film and increases the working strength when mixed with the resin; in addition, the small particle size of the calcium carbonate powder itself has a large specific surface area and surface energy (i.e. the reverse agglomeration force of the crushing force), which is easy to cause agglomeration to form large particles, resulting in wide particle size distribution of the powder, affecting the stability of the processing technology and the use effect of the breathable film; (2) if the particle size is too large, the pores in the cast film will become large, which will cause the pore size in the cast film to become large and the water to be permeable, and in severe cases, the film may be broken; in addition, the large particles will become stress concentration points in the high polymer matrix, affecting the performance of the product or even unable to be processed downstream.

[0004] These factors result in high production cost of the breathable film. Therefore, under the background of the rapid development of the domestic and foreign breathable film market, carrying out the key technology research of the special porogen for the breathable film is beneficial to promote the development of the breathable film technology. SUMMARY

[0005] Based on the technical problems existing in the background technology, the present application proposes a kind of porogen and application thereof, an antibacterial breathable film and a preparation method thereof, the present application selects copper sulfate crystal hydrate as core material, and is covered by skin layer to obtain porogen, combined with microwave heating, can make the antibacterial breathable film pore-forming uniform, and has bactericidal effect;And the preparation method of the porogen and the breathable film is simple, suitable for industrial production.

[0006] The present application proposes a kind of porogen, comprising: core material and skin layer coated on the surface of the core material, wherein the core material is copper sulfate crystal hydrate, and the skin layer is a non-polar substance with a melting point of ≤120℃.

[0007] Preferably, the copper sulfate crystal hydrate is CuSO4·5H2O when losing 1-3 crystal waters by heating.

[0008] Preferably, the copper sulfate crystalline hydrate is the substance when CuSO4·5H2O loses 1-3 crystal water under heating.

[0009] Copper sulfate is easy to absorb water vapor in the air to become a hydrate, and the product is generally in the form of CuSO4·5H2O. CuSO4·5H2O loses crystal water after heating, loses two crystal water when heated to about 102℃, loses three crystal water when heated to about 113℃, and loses all crystal water at 258℃.

[0010] The present application selects copper sulfate crystalline hydrate as the substance when CuSO4·5H2O loses 1-3 crystal water under heating, which can avoid the problem that when the core material of the pore former is CuSO4·5H2O, CuSO4·5H2O gradually loses water during subsequent intensive mixing, granulation, and film casting processes, affecting the intensive mixing and film casting effect, and causing large pores or film rupture.

[0011] Using non-polar substances as the skin layer to coat the core material can avoid the core material from being re-hydrated to CuSO4·5H2O, affecting the preparation of breathable films. CuSO4·5H2O can be heated to lose 1-3 crystal water by heating and drying, spray drying, etc.

[0012] Preferably, the skin layer is a non-polar high molecular compound with a melting point ≤120℃.

[0013] Preferably, the skin layer is a polyethylene wax.

[0014] Preferably, the weight ratio of the core material to the skin layer is 100:0.01-5.

[0015] Preferably, the core material is a silane coupling agent modified copper sulfate crystalline hydrate.

[0016] The above-mentioned core material can be a copper sulfate crystalline hydrate or a silane coupling agent modified copper sulfate crystalline hydrate. After modification by a silane coupling agent, the interface between the copper sulfate crystalline hydrate and the skin layer is more stable.

[0017] Preferably, the silane coupling agent modified copper sulfate crystalline hydrate is prepared by mixing CuSO4 or CuSO4·5H2O with a silane coupling agent hydrolysis solution, grinding, and drying.

[0018] During the above-mentioned grinding process, CuSO4 or CuSO4·5H2O is dissolved, and CuSO4 in the final solution is in a saturated state.

[0019] Preferably, the grinding is carried out at 70-90℃ for 60-600min.

[0020] Preferably, the drying is spray drying; preferably, the spray drying temperature is 180-220℃, more preferably, the spray drying temperature is 210℃, which can remove free water and make CuSO4·5H2O lose part of crystal water.

[0021] Preferably, the pH of the silane coupling agent hydrolysis solution is 8.5-9.5.

[0022] Preferably, the content of the silane coupling agent in the silane coupling agent hydrolysis solution is 0.1-20wt%.

[0023] Preferably, the solvent in the silane coupling agent hydrolysis solution is an ethanol aqueous solution.

[0024] In the above-mentioned silane coupling agent hydrolysis solution, ammonia can be used to adjust the pH; the volume fraction of ethanol in the ethanol aqueous solution can be 80-99%; the silane coupling agent can be γ-(2,3-epoxypropoxy)propyltrimethoxysilane, γ-aminopropyltriethoxysilane, etc.

[0025] Preferably, the D50 particle size of the pore-forming agent is 1.8-2.2μm.

[0026] Preferably, the D97 particle size of the pore-forming agent is <6.5μm.

[0027] Preferably, the specific surface area of the pore-forming agent is 5-15m 2 / g.

[0028] Preferably, the density of the pore-forming agent is >2.9g / cm 3 .

[0029] Preferably, in the pore-forming agent, the content of the pore-forming agent with a particle size of 1-5μm is ≥60%.

[0030] Preferably, in the pore-forming agent, the content of the pore-forming agent with a particle size ≥10μm is <100ppm.

[0031] The above-mentioned D50 refers to the sieve aperture size through which 50wt% of particles can pass; D97 refers to the sieve aperture size through which 97wt% of particles can pass.

[0032] The present application also proposes a preparation method of the above-mentioned pore-forming agent, comprising the following steps: coating a core material with a molten skin layer to obtain the pore-forming agent.

[0033] Preferably, the core material needs to be dried; preferably, the drying temperature is 113-180℃, more preferably, the drying temperature is 180℃; the core material is dried at a suitable temperature before use, which can remove free water in the core material and also make the CuSO4·5H2O formed by re-hydration of the core material lose 1-3 crystal waters under heating.

[0034] In the preparation method of the above-mentioned pore-forming agent, the molten skin layer is mixed with the core material, stirred for coating for more than or equal to 60 min, cooled, and particle size classified to obtain the pore-forming agent.

[0035] The application also provides application of the above-mentioned pore-forming agent in a breathable film.

[0036] The application also provides an antibacterial breathable film, which comprises resin and the above-mentioned pore-forming agent, wherein the resin is at least one of non-polar resin and low-polar resin.

[0037] Preferably, the melting point of the resin is greater than the melting point of the skin layer.

[0038] Preferably, the non-polar resin comprises at least one of polyethylene and polypropylene.

[0039] Preferably, the low-polar resin is at least one of nylon, polylactic acid and polycarbonate resin.

[0040] The above-mentioned low-polar resin refers to a resin with relatively low polarity.

[0041] The content of the pore-forming agent in the antibacterial breathable film is not specified, and can be determined according to the requirement of the air permeability of the product.

[0042] The raw material of the above-mentioned antibacterial breathable film can also contain antioxidants, lubricants, plasticizers and other auxiliary agents, and the amount of the auxiliary agents is not specified, and can be determined according to specific requirements, and the auxiliary agents can be purchased from the market; the above-mentioned antibacterial breathable film can be used in many fields such as medical health, personal care, building and agricultural and sideline product packaging.

[0043] The application also provides a preparation method of the above-mentioned antibacterial breathable film, characterized in that the method comprises the following steps: compounding and granulating resin and pore-forming agent, casting film, stretching and shaping to obtain the antibacterial breathable film, wherein microwave heating is performed at the same time of stretching.

[0044] Preferably, the temperature of microwave heating is 260-270 DEG C.

[0045] Preferably, the time of microwave heating is the same as the time of stretching.

[0046] Preferably, the temperature of compounding and granulating, casting film and stretching is less than 258 DEG C.

[0047] Preferably, the temperature during stretching is set between the high-elastic state temperature and the viscous flow state temperature of the resin.

[0048] The above-mentioned resin and pore-forming agent need to be dried before use to remove free water.

[0049] When the temperature is low, the deformation of the resin is very small; when the temperature is increased to a certain range, the deformation of the resin is obviously increased, and the deformation is relatively stable in a certain temperature range, which is a high-elasticity state, and the corresponding temperature range is a high-elasticity temperature; when the temperature continues to increase, the resin gradually becomes a viscous fluid, which is a viscous flow state, and the corresponding temperature range is a viscous flow temperature.

[0050] Advantages:

[0051] 1. The present application adopts the method of stretching and microwave heating at the same time, the core material copper sulfate crystal hydrate in the porogen is dehydrated into water vapor, and the heat of copper sulfate will make the local temperature around it increase, so that the skin layer melts, the water vapor is discharged to form fine and uniform micropores, and the non-polar resin is not heated after being heated by the microwave, and the low-polarity resin is heated slowly after being heated by the microwave, so that the size of the film can be kept stable; and in the process of preparing the breathable film, the interfacial force has an important influence on the stretching pore-forming property, pore structure, air permeability and mechanical property of the breathable film, the water vapor generated by the dehydration of the core material copper sulfate crystal hydrate under heat will also make the copper sulfate and the skin layer / resin interface debonding and phase separation, weaken the interfacial force between them, so that the pores are uniformly formed; in addition, the skin layer is a non-polar substance, which can make the porogen and the resin uniformly dispersed, and further improve the uniformity of the pore-forming effect;

[0052] 2. After microwave heating, the breathable film contains copper sulfate in the micropores, and the soluble copper ions have a sterilization function, so that the breathable film has an antibacterial function;

[0053] 3. The temperature at which the core material copper sulfate crystal hydrate loses all crystal water is 258℃, which is relatively high, and the temperature during the mixing, granulation, casting and stretching of the resin is lower than this temperature, so the present application can be applied to high processing temperature; and when the porogen described in the present application is used to prepare the breathable film, the stretching rate can be increased to 500mm / min, which is much higher than the stretching rate (110mm / min) when calcium carbonate is used, so that the production speed of the breathable film can be accelerated; and the porogen and the preparation method of the breathable film described in the present application are simple and suitable for industrial production. BRIEF DESCRIPTION OF DRAWINGS

[0054] Figure 1 The preparation process flow chart of the antibacterial breathable film described in the present application, wherein PE wax is polyethylene wax, and LLDPE is linear low density polyethylene resin.

[0055] Figure 2 The working mechanism diagram of the antibacterial breathable film described in the present application. DETAILED DESCRIPTION

[0056] The technical solutions of the present application will be described in detail below through specific embodiments, but it should be made clear that these embodiments are used for illustration only, but not to be construed as limiting the scope of the present application.

[0057] Example 1

[0058] A preparation method of a porogen, comprising the following steps:

[0059] CuSO4·5H2O is added into a hydrolysis solution of γ-(2,3-epoxypropoxy) propyl trimethoxysilane with a content of 12wt% and pH=9 (the hydrolysis solution is an aqueous solution of ethanol with a volume fraction of 89%), ball-milling is performed at 80℃ for 300min, CuSO4·5H2O is dissolved in the process of milling, CuSO4 in the final solution is in a saturated state, and then spray drying is performed at 180℃ to obtain silane coupling agent modified copper sulfate crystalline hydrate as a core material;

[0060] 100 parts of the core material are dried at 180℃ with high-speed stirring, then 1.1 parts of polyethylene wax is added, the temperature is adjusted to 160℃ to melt the polyethylene wax, and stirring is performed for 60min for coating, after cooling, airflow is used for fine classification of particle size to obtain the porogen, wherein the D50 particle size of the porogen is 2.0μm, the D97 particle size of the porogen is 6.2μm, the specific surface area of the porogen is 11m 2 / g, and the density of the porogen is 3.4g / cm 3 In the porogen, the content of the porogen with a particle size of 1-5μm is 61%; and in the porogen, the content of the porogen with a particle size of ≥10μm is 90ppm.

[0061] A preparation method of an antibacterial breathable film, comprising the following steps:

[0062] The above porogen 22.5 parts and linear low density polyethylene resin (melting point 125℃) 100 parts are dried in an oven under nitrogen protection at 112℃, then mixed with antioxidant 1.1 parts, lubricant 2.1 parts, and plasticizer 0.8 parts for mixing, compounding and granulating; then a cast film is prepared on a small-sized casting machine set, the temperature of the extruder is 200℃, the temperature of the casting die is 220℃, the temperature of the casting roller is 90℃, the distance between the die and the casting roller is 4cm, an air knife with an opening of 0.5mm is arranged between the die and the casting roller to provide air for cooling the surface of the melt film, and the air speed of the air knife is 2m / s;

[0063] The prepared cast film is cut into a sample of 100mm x 45mm, and the sample is stretched using an electric stretching instrument provided with a thermostat and a microwave heating device, the stretching temperature is 100℃, the stretching ratio is 2.6, and the stretching rate is 500mm / min; then the polyethylene breathable film is obtained by heat setting for 30min; in the stretching setting stage, the microwave heating device is used to heat the stretched and set film, the microwave temperature is 265℃, the microwave heating time is the same as the stretching time, and the obtained antibacterial breathable film has an average pore size of 4.9μm and a porosity of 54.4%.

[0064] Figure 1 The preparation process flow chart of the antibacterial breathable film is shown in the figure, wherein the PE wax is a polyethylene wax, and the LLDPE is a linear low-density polyethylene resin.

[0065] Figure 2 The working mechanism diagram of the antibacterial breathable film is shown in the figure.

[0066] The breathable film is prepared according to the method in Example 1, wherein the porogen in Example 1 is replaced by superfine calcium carbonate with the same particle size; it is found that when the stretching rate is 500mm / min, the pore size distribution of the breathable film is uneven and the size is not uniform, and the stretching rate cannot be too high; when the stretching rate is adjusted to 110mm / min, the porosity of the obtained breathable film is 43%, which is 11% lower than that of Example 1.

[0067] Example 2

[0068] A preparation method of a porogen comprises the following steps:

[0069] CuSO4·5H2O is added into a hydrolysis solution of γ-(2,3-epoxypropoxy) propyl trimethoxysilane with a pH value of 9 and a content of 15wt%, the hydrolysis solution is an aqueous ethanol solution with a volume fraction of 81%, ball milling is carried out at 80℃ for 600min, CuSO4·5H2O is dissolved in the process of milling, CuSO4 in the final solution is in a saturated state, and then spray drying is carried out at 210℃ to obtain a silane coupling agent modified copper sulfate crystal hydrate as a core material;

[0070] 100 parts of the core material are dried at a high speed under stirring at 180℃, then 0.5 parts of polyethylene wax are added, the temperature is adjusted to 160℃ to melt the polyethylene wax, and the stirring is carried out for 60min, after cooling, the airflow is used for fine classification of particle size to obtain the porogen, wherein the D50 particle size of the porogen is 1.9μm, the D97 particle size of the porogen is 5.9μm, the specific surface area of the porogen is 13m 2 / g, and the density of the porogen is 3.2g / cm 3; the content of the pore-forming agent with a particle size of 1-5 μm in the pore-forming agent is 71%; and the content of the pore-forming agent with a particle size of ≥10 μm in the pore-forming agent is 80 ppm.

[0071] A method for preparing an antibacterial and breathable film, comprising the following steps:

[0072] The above-mentioned pore-forming agent 28 parts and polypropylene resin (melting point 205℃) 100 parts are dried in an oven under nitrogen protection at 190℃, and then mixed with antioxidant 1 part, lubricant 0.8 part, plasticizer 2 parts for mixing, granulation; then a casting film is prepared on a small casting machine set, the temperature of the extruder is 210℃, the temperature of the casting die is 230℃, the temperature of the casting roller is 110℃, the distance between the die and the casting roller is 4 cm, an air knife with an opening of 0.5 mm is arranged between the die and the casting roller to provide air to cool the surface of the melt film, and the air speed of the air knife is 2 m / s;

[0073] The prepared casting film is cut into a sample of 100 mm x 45 mm, and the casting film sample is stretched using an electric stretching instrument with a constant temperature box and a microwave heating device, the stretching temperature is 203℃, the stretching ratio is 2.4, and the stretching rate is 400 mm / min; then heat setting for 30 min to obtain a polypropylene breathable film; in the stretching setting stage, the microwave heating device is used for microwave heating while stretching and setting, the microwave temperature is 270℃, the microwave heating time is the same as the stretching time, and an antibacterial and breathable film with an average pore size of 4.7 μm and a porosity of 48% is obtained.

[0074] Example 3

[0075] A method for preparing a pore-forming agent, comprising the following steps:

[0076] CuSO4·5H2O is added to a hydrolyzed solution of γ-(2,3-epoxypropoxy) propyl trimethoxysilane with a content of 10 wt% and pH = 9 (the hydrolyzed solution is an aqueous ethanol solution with a volume fraction of 82%), ball milling at 80℃ for 300 min, and CuSO4·5H2O is dissolved in the process of milling, CuSO4 in the final solution is in a saturated state, and then spray drying at 185℃ to obtain a silane coupling agent modified copper sulfate crystal hydrate as a core material;

[0077] 100 parts of the core material are dried at 180℃ with high-speed stirring, then 5 parts of polyethylene wax are added, the temperature is adjusted to 160℃ to melt the polyethylene wax, stirring is carried out for 60 min, and after cooling, airflow is used for fine classification of particle size to obtain the pore-forming agent, wherein the D50 particle size of the pore-forming agent is 2.2 μm, the D97 particle size of the pore-forming agent is 6.1 μm, the specific surface area of the pore-forming agent is 12 m 2 / g, and the density of the pore-forming agent is 3.2 g / cm 3; the content of the pore-forming agent with a particle size of 1-5 μm in the pore-forming agent is 71%; and the content of the pore-forming agent with a particle size of ≥10 μm in the pore-forming agent is 96 ppm.

[0078] A method for preparing an antibacterial and breathable film, comprising the following steps:

[0079] The above-mentioned pore-forming agent 20 parts and nylon resin (melting point 177℃) 100 parts are dried in an oven under nitrogen protection at 151℃, and then mixed with antioxidant 2 parts, lubricant 1 part, and plasticizer 2.5 parts for mixing, compounding, and granulation; then a casting film is prepared on a small casting machine set, the temperature of the extruder is 180℃, the temperature of the casting die is 190℃, the temperature of the casting roller is 100℃, the distance between the die and the casting roller is 4 cm, and an air knife with an opening of 0.5 mm is arranged between the die and the casting roller to provide air to cool the surface of the melt film, and the air speed of the air knife is 2 m / s.

[0080] The prepared casting film is cut into a sample of 100 mm x 45 mm, and the sample is stretched using an electric stretching instrument with a constant temperature box and a microwave heating device, the stretching temperature is 175℃, the stretching ratio is 2.5, and the stretching rate is 300 mm / min; then the film is heat set for 30 min to obtain a nylon breathable film; during the stretching and setting stage, the microwave heating device is used for microwave heating while the film is being stretched and set, the microwave temperature is 265℃, and an antibacterial and breathable film with an average pore size of 5.2 μm and a porosity of 54% is obtained.

[0081] Example 4

[0082] A method for preparing a pore-forming agent, comprising the following steps:

[0083] CuSO4·5H2O is prepared into a saturated aqueous solution of CuSO4, and then the core material is obtained by spray drying at 210℃; the other steps are the same as in Example 1.

[0084] A method for preparing an antibacterial and breathable film is the same as in Example 1, and an antibacterial and breathable film with an average pore size of 5.0 μm and a porosity of 51% is obtained.

[0085] The stretching is performed simultaneously with microwave heating, the non-polar resin does not heat up after being heated by the microwave, the low-polar resin heats up slowly after being heated by the microwave, the core material copper sulfate hydrate in the pore-forming agent is heated and dehydrated to become CuSO4 and the water vapor expands, so that the CuSO4 and the polyethylene wax (or resin) interface debond, and the heat of the copper sulfate increases the local temperature near it, so that the polyethylene wax melts, the water vapor escapes to form fine and uniform micropores, the pores contain copper sulfate, the soluble copper ions have a bactericidal function, and the pores have an antibacterial effect.

[0086] By adjusting the extruder temperature, the casting die temperature, the casting roller temperature, the distance between the die and the casting roller, the stretching, the microwave and other process parameters, the pore size distribution of the breathable film can be made more uniform.

[0087] When the porous agent is used to prepare the breathable film, the stretching rate can be ≤500 mm / min, and the highest can be 500 mm / min; the stretching rate is much higher than that of using ultra-fine calcium carbonate as the porogenic agent, and the maximum stretching rate of using ultra-fine calcium carbonate as the porogenic agent is 110 mm / min, and the porosity will be uneven above this speed, and the porous agent has excellent porogenic effect.

[0088] Comparative Example 1

[0089] A preparation method of a porous agent, comprising the following steps:

[0090] The temperature is adjusted to 95℃ to melt the polyethylene wax, CuSO4·5H2O is added and stirred for 60 min for coating, and after cooling, the porous agent is prepared by airflow fine classification of particle size, and the others are the same as in Example 1.

[0091] The porous agent is taken, and the breathable film is prepared according to the method in Example 1, and film rupture occurs during preparation.

[0092] The antibacterial breathable film prepared in Examples 1-4 is detected, and the results are shown in Table 1.

[0093] The porosity is determined by the liquid absorption method according to ASTM D-2873; the bacterial filtration efficiency and the non-oily particle filtration efficiency are determined by using a gas permeability tester; and the synthetic blood penetration of the breathable film under a certain pressure is detected by using a synthetic blood tester.

[0094] Table 1: Test results

[0095] Test item Example 1 Example 2 Example 3 Example 4 Bacterial filtration efficiency % 98.8 99.1 98.6 98.6 Non-oily particle filtration efficiency % 97.5 98.5 97.2 97.3 Synthetic blood penetration mm Hg 161 164 158 159 Breath resistance mm H20 / cm 2 ]] 5.8 5.7 5.9 5.9 Air permeable film average pore size pm 4.9 4.7 5.2 5.0 Porosity % 54.4 48 54 51

[0096] As can be seen from Table 1, the present application has good antibacterial property, breathability and filtration property.

[0097] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can make equivalent replacement or change according to the technical solution and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. An antimicrobial, breathable film, characterized in that, The raw materials include resin and porogen, wherein the resin is at least one of non-polar resin and low-polar resin; The porogen includes core material and skin layer coated on the surface of the core material, wherein the core material is copper sulfate crystal hydrate or silane coupling agent modified copper sulfate crystal hydrate, and the skin layer is non-polar substance with melting point ≤ 120℃; The copper sulfate crystal hydrate is the substance when CuSO4·5H2O loses 1-3 crystal water by heating; In the preparation process of the antibacterial and breathable film, the resin and the porogen are mixed and granulated by internal mixing, and then the film is prepared by casting, and microwave heating is performed at the same time of stretching; The temperature of microwave heating is 260-270℃.

2. The antimicrobial breathable film according to claim 1, wherein, The melting point of the resin is higher than that of the skin layer.

3. The antimicrobial breathable film according to claim 1, wherein, The non-polar resin includes at least one of polyethylene and polypropylene.

4. The antimicrobial breathable film according to claim 1, wherein, The low-polar resin is at least one of nylon, polylactic acid and polycarbonate resin.

5. The antimicrobial breathable film according to claim 1, wherein, The skin layer is a non-polar high molecular compound with melting point ≤ 120℃.

6. The antimicrobial breathable film according to claim 1, wherein, The skin layer is polyethylene wax.

7. The antimicrobial breathable film according to claim 1, wherein, The weight ratio of the core material to the skin layer is 100:0.01-5.

8. The antimicrobial, breathable film of claim 1, wherein, The silane coupling agent modified copper sulfate crystal hydrate is prepared by mixing CuSO4 or CuSO4·5H2O with silane coupling agent hydrolysis solution, grinding and drying.

9. The antimicrobial, breathable film of claim 8, wherein, Grinding at 70-90℃ for 60-600min.

10. The antimicrobial, breathable film of claim 8, wherein, The drying is spray drying.

11. The antimicrobial breathable film according to claim 8, wherein, The drying temperature is 180-220℃.

12. The antimicrobial breathable film according to claim 8, wherein, The pH of the silane coupling agent hydrolysis solution is 8.5-9.

5.

13. The antimicrobial breathable film according to claim 8, wherein, The content of the silane coupling agent in the silane coupling agent hydrolysis solution is 0.1-20wt%.

14. The antimicrobial breathable film according to claim 8, wherein, The solvent in the silane coupling agent hydrolysis solution is ethanol aqueous solution.

15. The antimicrobial, breathable film of claim 1, wherein, The D50 particle size of the porogen is 1.8-2.2μm.

16. The antimicrobial, breathable film of claim 1, wherein, The D97 particle size of the porogen is < 6.5μm.

17. The antimicrobial, breathable film of claim 1, wherein, The specific surface area of the pore-forming agent is 5-15 m 2 / g.

18. The antimicrobial, breathable film of claim 1, wherein, Density of porogen > 2.9 g / cm 3 .

19. The antimicrobial, breathable film of claim 1, wherein, In the porogen, the content of the porogen with particle size of 1-5μm is ≥ 60%.

20. The antimicrobial, breathable film of claim 1, wherein, In the porogen, the content of the porogen with particle size ≥ 10μm is < 100ppm.

21. The antimicrobial, breathable film of claim 1, wherein, The preparation method of the porogen includes the following steps: coating the core material with molten skin layer to obtain the porogen.

22. The antimicrobial breathable film of claim 21, wherein, The core material needs to be dried.

23. The antimicrobial breathable film of claim 22, wherein, The drying temperature is 113-180℃.

24. A method of making the antimicrobial, breathable film of any one of claims 1-23, wherein, The preparation method includes the following steps: mixing and granulating the resin and the porogen by internal mixing, casting the film, stretching, and shaping to obtain the antibacterial and breathable film, wherein microwave heating is performed at the same time of stretching.

25. The method of making the antimicrobial, breathable film of claim 24, wherein, The time of microwave heating is the same as the time of stretching.

26. The method of making the antimicrobial breathable film of claim 24, wherein, The temperature of mixing and granulating, casting the film and stretching is < 258℃.

27. The method of making the antimicrobial breathable film of claim 24, wherein, The temperature during stretching is set between the high-elastic state temperature and the viscous flow state temperature of the resin.

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