Multifunctional polyethylene breathable film and preparation method therefor

Abstract

The present application relates to the field of polyethylene films, and particularly discloses a multifunctional polyethylene breathable film and a preparation method therefor. The multifunctional polyethylene breathable film comprises the following raw materials in percentage by weight: 15%-30% of linear low-density polyethylene, 15%-40% of metallocene linear low-density polyethylene, 5%-10% of low-density polyethylene, 30%-50% of breathable masterbatch, 2%-10% of antistatic masterbatch, 2%-10% of antibacterial masterbatch, 5%-10% of flame-retardant masterbatch, and 2%-5% of color masterbatch. The preparation method for the multifunctional polyethylene breathable film comprises the following steps: mixing linear low-density polyethylene, metallocene linear low-density polyethylene, low-density polyethylene, breathable masterbatch, antistatic masterbatch, antibacterial masterbatch, flame-retardant masterbatch, and color masterbatch according to a formula ratio, performing melt extrusion, performing blow molding, drawing and stretching to form a film, and performing corona treatment. The prepared breathable film not only has good breathability and mechanical properties, but also has excellent antistatic, flame-retardant and antibacterial functions.

Description

A multifunctional polyethylene breathable film and preparation method thereof Technical Field

[0001] The present application relates to the technical field of polyethylene films, and more specifically, to a multifunctional polyethylene breathable film and a preparation method thereof. Background Art

[0002] Polyethylene is a non-toxic, low-temperature-resistant, and chemically stable thermoplastic resin. Polyethylene film is a composite polymer material made from polyethylene as a base material, with fillers and additives added. Polyethylene film is widely used in the chemical, medical, and food industries, and has promising development and expansion prospects. Polyethylene film is subdivided into several types based on different functions, and polyethylene breathable film is the most widely used in the market today.

[0003] Currently, polyethylene breathable membranes are made from the following raw materials in the following weight percentages: 45-55% calcium carbonate powder, 1-8% compatibilizer and flow modifier, 1-5% processing aid, 0.1-1% anti-aging agent, 25-35% metallocene polyethylene, 5-15% linear low-density polyethylene, and 5-10% low-density polyethylene. The calcium carbonate powder is an ultrafine calcium carbonate powder with a particle diameter less than 60nm and surface-modified with a coupling agent. Using a polyethylene blend combined with the corresponding modified calcium carbonate particles and compatibilizer and flow modifier effectively improves the mechanical properties of the breathable membrane, resulting in a low weight and high low-temperature toughness.

[0004] When the above-mentioned polyethylene breathable film was applied to protective clothing in the medical industry, it was found that the product was prone to generate static electricity and was flammable during use, and could not play a good antibacterial role, and could not meet the actual needs of users.

[0005] Summary of the Invention

[0006] The present application provides a multifunctional polyethylene breathable membrane and a preparation method thereof. The prepared breathable membrane not only has good air permeability, but also has excellent antistatic, flame retardant and antibacterial functions, which can meet the user's different functional requirements for the breathable membrane.

[0007] In the first aspect, the present application provides a multifunctional polyethylene breathable membrane adopting the following technical solution:

[0008] A multifunctional polyethylene breathable film comprises the following raw materials in percentage by weight: 15%-30% linear low-density polyethylene, 15%-40% metallocene linear low-density polyethylene, 5%-10% low-density polyethylene, 30%-50% breathable masterbatch, 2%-10% antistatic masterbatch, 2%-10% antibacterial masterbatch, 5%-10% flame retardant masterbatch, and 2%-5% color masterbatch.

[0009] Metallocene linear low-density polyethylene (LLDPE) has a low melting point and offers excellent toughness, transparency, and hot tack. It also has high softening and melting temperatures, along with excellent resistance to environmental stress cracking, impact strength, and tear resistance. LDPE also boasts excellent chemical stability, flexibility, extensibility, electrical insulation, transparency, ease of processing, and moderate breathability. Compounding LLDPE, LLDPE, and LDPE facilitates system balance and excellent processing performance, thereby improving the mechanical properties of the product. When combined with a breathable masterbatch, it not only enhances the product's breathability but also ensures more uniform ventilation. When combined with an antistatic masterbatch, it effectively reduces the product's surface resistance and imparts excellent antistatic properties. It also synergizes with a flame-retardant masterbatch to enhance its flame retardancy. The antibacterial masterbatch exhibits excellent antibacterial properties against Escherichia coli and Staphylococcus aureus, meeting the diverse functional requirements of breathable membranes.

[0010] Furthermore, the breathable masterbatch comprises the following raw materials in percentage by weight: 40-80% polyethylene, 40-60% calcium carbonate, 0.5%-2% antioxidant, 0.3-1% lubricant, and 1%-2.5% anti-yellowing agent.

[0011] Furthermore, the antistatic masterbatch comprises the following raw materials in percentage by weight: 40-80% polyethylene, 30-60% antistatic agent, 0.5%-2% antioxidant, 0.3-1% lubricant, and 1%-2.5% anti-yellowing agent.

[0012] Furthermore, the antibacterial masterbatch comprises the following raw materials in weight percentage: 40-80% polyethylene, 20-50% calcium carbonate, 2-10% antibacterial agent, 0.5%-2% antioxidant, 0.3-1% lubricant, and 1%-2.5% anti-yellowing agent.

[0013] Furthermore, the flame retardant masterbatch comprises the following raw materials in percentage by weight: 40-80% polyethylene, 15%-50% bismaleimide, 0.5%-2% antioxidant, 0.3-1% lubricant, and 1%-2.5% anti-yellowing agent.

[0014] Furthermore, the antioxidant is antioxidant 1010, antioxidant 168 or antioxidant 1076.

[0015] Furthermore, the lubricant is stearate; specifically, the lubricant can be zinc stearate or calcium stearate.

[0016] The anti-yellowing agent is a hydrazide anti-yellowing agent; further anti-yellowing agent is adipic acid dihydrazide.

[0017] Furthermore, the polyethylene includes 15%-40% linear low-density polyethylene, 10%-20% metallocene linear low-density polyethylene, and 5%-15% low-density polyethylene.

[0018] By adopting the above technical solution, linear low-density polyethylene, metallocene linear low-density polyethylene, and low-density polyethylene are selected for compounding in the preparation process of breathable masterbatch, antistatic masterbatch, antibacterial masterbatch, and flame-retardant masterbatch, thereby further improving the compatibility and processing performance between the raw material components, and at the same time improving the mechanical properties of the product.

[0019] Through research experiments, it was found that using bismaleimide as a flame retardant can effectively avoid the problem of poor dispersion of inorganic flame retardants in organic systems. At the same time, it can also assist antistatic masterbatch in synergistically improving the antistatic properties of the product.

[0020] Furthermore, the particle size of the calcium carbonate is 1 μm-4 μm.

[0021] By adopting the above technical solution, the particle size of calcium carbonate is strictly controlled so that the calcium carbonate has good dispersion in the system, which is conducive to the excellent air permeability of the breathable membrane after stretching.

[0022] Furthermore, the antistatic agent is prepared by the following steps: uniformly dispersing zinc oxide and polyetherimide in a mixture of a silane coupling agent and a calcium source solution to form a slurry, adding a carbonate solution to the slurry while stirring to obtain a solid product, and filtering and drying the solid product to obtain the antistatic agent.

[0023] Furthermore, the amounts of the components of the antistatic agent are as follows: by weight, 1-5 parts of zinc oxide, 1-3 parts of polyetherimide, 0.1-0.5 parts of silane coupling agent, 10-20 parts of calcium source solution, and 12-22 parts of carbonate solution.

[0024] Furthermore, the calcium source solution is a calcium acetate solution or a calcium nitrate solution, and the carbonate solution is a sodium carbonate solution; the concentration of calcium acetate in the calcium acetate solution is 8-12%, the concentration of calcium nitrate in the calcium nitrate solution is 10-15%, and the concentration of sodium carbonate in the sodium carbonate solution is 12-18%.

[0025] Calcium acetate solution or calcium nitrate solution can provide calcium ions, and sodium carbonate solution provides carbonate ions, which is conducive to the combination of the two to form calcium carbonate precipitation.

[0026] Furthermore, the calcium source solution is preferably a calcium acetate solution. The sodium acetate generated by the reaction of the calcium acetate solution with the sodium carbonate solution can play a certain role in thickening, lubrication and adhesion, which can improve the ductility and processing performance of the plastic product, thereby improving the mechanical properties of the product. At the same time, it can also give the product a certain antiseptic and antibacterial effect, helping the antibacterial masterbatch to improve the antibacterial performance of the product.

[0027] Zinc oxide and polyetherimide are first evenly dispersed in a mixture of a silane coupling agent and a calcium source solution. The silane coupling agent effectively improves the compatibility and uniformity of the raw material components. Subsequently, carbonate ions from the carbonate solution combine with calcium ions in the calcium source solution, entraining the zinc oxide and polyetherimide during stirring and forming a calcium carbonate precipitate. The resulting antistatic agent not only has excellent antistatic properties but can also be used as a filler in conjunction with an antistatic masterbatch to reinforce the product. It also promotes uniform dispersion of the components, improves their intercompatibility, and enhances the product's mechanical properties. Zinc oxide not only has good antistatic properties but also exhibits a certain degree of antibacterial activity, which can be further enhanced when combined with an antibacterial masterbatch. Polyetherimide also has a certain degree of flame retardancy, which can be combined with a flame retardant masterbatch to improve the product's flame retardancy.

[0028] Furthermore, the antibacterial agent includes tea polyphenols and / or clove essential oil.

[0029] Furthermore, tea polyphenols and clove essential oil are compounded in a weight ratio of 1: (0.5-1).

[0030] By adopting the above technical solution, both tea polyphenols and clove essential oil can have a good antibacterial effect. After compounding tea polyphenols and clove essential oil, the product's inhibitory effect on Escherichia coli and Staphylococcus aureus can be effectively improved, achieving an excellent antibacterial effect.

[0031] In a second aspect, the present application provides a method for preparing a multifunctional polyethylene breathable membrane, which adopts the following technical solution:

[0032] A method for preparing a multifunctional polyethylene breathable film comprises the following steps: mixing linear low-density polyethylene, metallocene linear low-density polyethylene, low-density polyethylene, breathable masterbatch, antistatic masterbatch, antibacterial masterbatch, flame retardant masterbatch and color masterbatch according to the formula amount, melt extruding, blow molding, pulling, stretching into film, and corona treatment.

[0033] Furthermore, after the raw material components are mixed, they are extruded and melted by three-layer co-extrusion and then extruded from a die head. That is, they are melted by three screws and fused at the die head, and then extruded through a die head. The die head temperature is 175-185°C and the extrusion rate is 560-600kg / h.

[0034] Furthermore, the pulling speed is 25 m / min and the stretching ratio is 4.4-4.6.

[0035] Furthermore, the breathable masterbatch is prepared by twin-screw extrusion granulation of each raw material component according to the formula amount to obtain a breathable masterbatch with a melt index of 1-2g / 10min;

[0036] Furthermore, the antistatic masterbatch is prepared by subjecting the raw material components to twin-screw extrusion granulation according to the formula amount to obtain an antistatic masterbatch with a melt index of 10-20g / 10min;

[0037] Furthermore, the antibacterial masterbatch is prepared by twin-screw extrusion granulation of each raw material component according to the formula amount to obtain an antibacterial masterbatch with a melt index of 1-8g / 10min;

[0038] Furthermore, flame retardant masterbatch preparation: each raw material component is subjected to twin-screw extrusion granulation according to the formula amount to obtain a flame retardant masterbatch with a melt index of 2-10g / 10min;

[0039] By adopting the above technical solution: through the ratio of raw material components and combined with three-layer co-extrusion, the micropore path is improved, so that the breathable membrane has dense and interconnected micropores, and combined with the traction and stretching steps, the breathable membrane not only has excellent air permeability and mechanical properties, but also has excellent antistatic, flame retardant and antibacterial functions, which can meet the user's different functional requirements for breathable membranes.

[0040] In summary, this application has the following beneficial effects:

[0041] 1. Compounding linear low-density polyethylene, metallocene linear low-density polyethylene, and low-density polyethylene, along with breathable masterbatch, not only enhances the product's breathability but also ensures more uniform ventilation. The antistatic masterbatch effectively reduces the product's surface resistance, imparting excellent antistatic properties. It also synergizes with the flame-retardant masterbatch to effectively enhance its flame retardancy. The antibacterial masterbatch exhibits excellent antibacterial properties against Escherichia coli and Staphylococcus aureus, meeting users' diverse functional requirements for breathable membranes.

[0042] 2. Zinc oxide and polyetherimide are uniformly dispersed in a mixture of a silane coupling agent and a calcium source solution. The silane coupling agent effectively improves the compatibility and uniformity of the raw material components. The carbonate ions in the subsequently added carbonate solution combine with the calcium ions in the calcium source solution, entraining the zinc oxide and polyetherimide during stirring and forming a calcium carbonate precipitate. The resulting antistatic agent not only has excellent antistatic properties but can also be used as a filler in conjunction with an antistatic masterbatch to reinforce the product. It also promotes uniform dispersion of the components, improves their composite properties, and enhances the product's mechanical properties. Zinc oxide not only has good antistatic properties but also exhibits a certain antibacterial effect, which can be further combined with an antibacterial masterbatch to achieve excellent antibacterial effects. Polyetherimide also has certain flame retardancy, which can be combined with a flame retardant masterbatch to enhance the product's flame retardancy.

[0043] 3. Through the ratio of raw material components and the three-layer co-extrusion, the micropore path is improved, so that the breathable membrane has dense and interconnected micropores. Combined with the traction and stretching steps, the breathable membrane not only has excellent air permeability and mechanical properties, but also has excellent antistatic, flame retardant and antibacterial functions, which can meet the different functional requirements of users for breathable membranes. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] FIG1 is a microscopic image of the breathable membrane prepared in Example 6 of the present application under a scanning electron microscope at 10 μm.

[0045] FIG2 is a microscopic image of the breathable membrane prepared in Example 6 of the present application under a scanning electron microscope at 2 μm. DETAILED DESCRIPTION

[0046] The embodiments of the present invention will be described in detail below with reference to the examples. However, those skilled in the art will understand that the following examples are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention. Specific conditions not specified in the examples are carried out according to conventional conditions or conditions recommended by the manufacturer. Reagents or instruments used without indicating the manufacturer are all conventional products that can be purchased commercially.

[0047] In the following examples, the concentration of calcium acetate in the calcium acetate solution is 10%, the concentration of calcium nitrate in the calcium nitrate solution is 12%, and the concentration of sodium carbonate in the sodium carbonate solution is 15%.

[0048] Example

[0049] Example 1

[0050] A multifunctional polyethylene breathable film comprising the following raw materials in percentage by weight: 22% linear low-density polyethylene, 15% metallocene linear low-density polyethylene, 7% low-density polyethylene, 38% breathable masterbatch, 7% antistatic masterbatch, 5% antibacterial masterbatch, 3% flame retardant masterbatch, and 3% color masterbatch;

[0051] The breathable masterbatch comprises the following raw materials in the following weight percentages: linear low-density polyethylene 20%, metallocene linear low-density polyethylene 20%, low-density polyethylene 15%, calcium carbonate 42.5%, antioxidant 1.2%, lubricant 0.3%, and anti-yellowing agent 1%;

[0052] The antibacterial masterbatch comprises the following raw materials in weight percentage: 45% linear low-density polyethylene, 10% metallocene linear low-density polyethylene, 5% low-density polyethylene, 28% calcium carbonate, 10% antibacterial agent, 0.5% antioxidant, 0.3% lubricant, and 1.2% anti-yellowing agent;

[0053] The antibacterial agent is tea polyphenols;

[0054] The flame retardant masterbatch includes the following raw materials in weight percentage: linear low-density polyethylene 25%, metallocene linear low-density polyethylene 20%, low-density polyethylene 15%, bismaleimide 36%, antioxidant 1.6%, lubricant 0.4%, anti-yellowing agent 2%,

[0055] The antistatic masterbatch comprises the following raw materials in weight percentage: 40% linear low-density polyethylene, 10% metallocene linear low-density polyethylene, 5% low-density polyethylene, 41% antistatic agent, 2% antioxidant, 1% lubricant, and 1% anti-yellowing agent;

[0056] The antistatic agent is prepared by the following steps: 0.1 kg of zinc oxide and 0.3 kg of polyetherimide are uniformly dispersed in a mixture of 0.01 kg of a silane coupling agent and 1 kg of a calcium nitrate solution to form a slurry, 1.2 kg of a sodium carbonate solution is added to the slurry while stirring to obtain a solid product, and the solid product is filtered and dried to obtain the antistatic agent;

[0057] The particle size of calcium carbonate used in the breathable masterbatch, antibacterial masterbatch, flame retardant masterbatch and antistatic masterbatch is 1μm-4μm, the antioxidant is antioxidant 1010, the lubricant is zinc stearate, and the anti-yellowing agent is adipic acid dihydrazide.

[0058] The preparation method of the multifunctional polyethylene breathable film comprises the following steps:

[0059] Preparation of breathable masterbatch: The raw material components of the breathable masterbatch are subjected to twin-screw extrusion granulation according to the formula to obtain a breathable masterbatch with a melt index of 1-2g / 10min;

[0060] Preparation of antistatic masterbatch: The raw material components are extruded and granulated by twin screw extrusion according to the formula to obtain antistatic masterbatch with a melt index of 10-20g / 10min;

[0061] Preparation of antibacterial masterbatch: The raw material components are extruded and granulated by twin screw extrusion according to the formula to obtain antibacterial masterbatch with a melt index of 1-8g / 10min;

[0062] Preparation of flame retardant masterbatch: The raw material components are extruded and granulated by twin screw extrusion according to the formula to obtain flame retardant masterbatch with a melt index of 2-10g / 10min;

[0063] The prepared breathable masterbatch, antistatic masterbatch, antibacterial masterbatch, flame retardant masterbatch, linear low-density polyethylene, metallocene linear low-density polyethylene, low-density polyethylene and color masterbatch are fed into a mixer according to the formula amount for mixing, and then extruded through a die head after being melted by three-layer co-extrusion, that is, three screws are melted and fused at the die head, and extruded through a die head, the die head temperature is 175-185°C, and the extrusion rate is 580kg / h; followed by blow molding, traction, stretching film forming, and corona treatment, with a traction speed of 25m / min and a stretching ratio of 4.4-4.6.

[0064] Example 2

[0065] A multifunctional polyethylene breathable film comprising the following raw materials in weight percentage: 15% linear low-density polyethylene, 20% metallocene linear low-density polyethylene, 5% low-density polyethylene, 49% breathable masterbatch, 2% antistatic masterbatch, 2% antibacterial masterbatch, 5% flame retardant masterbatch, and 2% color masterbatch;

[0066] The breathable masterbatch comprises the following raw materials in the following weight percentages: 25% linear low-density polyethylene, 10% metallocene linear low-density polyethylene, 5% low-density polyethylene, 56% calcium carbonate, 0.5% antioxidant, 1% lubricant, and 2.5% anti-yellowing agent;

[0067] The antibacterial masterbatch comprises the following raw materials in weight percentage: 15% linear low-density polyethylene, 18% metallocene linear low-density polyethylene, 10% low-density polyethylene, 50% calcium carbonate, 2% antibacterial agent, 2% antioxidant, 1% lubricant, and 2% anti-yellowing agent;

[0068] The antibacterial agent is clove essential oil;

[0069] The flame retardant masterbatch includes the following raw materials in percentage by weight: linear low-density polyethylene 25%, metallocene linear low-density polyethylene 14%, low-density polyethylene 6.5%, bismaleimide 50%, antioxidant 1.4%, lubricant 1%, anti-yellowing agent 2.1%,

[0070] The antistatic masterbatch comprises the following raw materials in weight percentage: 40% linear low-density polyethylene, 12% metallocene linear low-density polyethylene, 15% low-density polyethylene, 30% antistatic agent, 0.5% antioxidant, 0.7% lubricant, and 1.8% anti-yellowing agent;

[0071] The antistatic agent is prepared by the following steps: 0.5 kg of zinc oxide and 0.1 kg of polyetherimide are uniformly dispersed in a mixture of 0.05 kg of a silane coupling agent and 2 kg of a calcium nitrate solution to form a slurry, 2.2 kg of a sodium carbonate solution is added to the slurry while stirring to obtain a solid product, and the solid product is filtered and dried to obtain the antistatic agent;

[0072] The particle size of calcium carbonate used in the breathable masterbatch, antibacterial masterbatch, flame retardant masterbatch and antistatic masterbatch is 6μm-10μm, the antioxidant is antioxidant 168, the lubricant is calcium stearate, and the anti-yellowing agent is anti-yellowing agent HN150.

[0073] The preparation method of the multifunctional breathable membrane is the same as that in Example 1.

[0074] Example 3

[0075] The difference from Example 1 is that the linear low-density polyethylene, metallocene linear low-density polyethylene and low-density polyethylene raw materials used in the breathable masterbatch, antibacterial masterbatch, flame retardant masterbatch and antistatic masterbatch are replaced by low-density polyethylene in equal amounts, and the rest are the same as Example 1.

[0076] Example 4

[0077] The difference from Example 1 is that in the antibacterial masterbatch, the antibacterial agent is tea polyphenols and clove essential oil in a weight ratio of 1:0.5, and the rest is the same as Example 1.

[0078] Example 5

[0079] The difference from Example 1 is that in the antibacterial masterbatch, the antibacterial agent is tea polyphenols and clove essential oil in a weight ratio of 3:1, and the rest is the same as Example 1.

[0080] Example 6

[0081] The difference from Example 4 is that the antistatic agent is prepared by the following steps: 0.3 kg of zinc oxide and 0.2 kg of polyetherimide are uniformly dispersed in a mixture of 0.04 kg of a silane coupling agent and 1.5 kg of a calcium nitrate solution to form a slurry, and 1.6 kg of a sodium carbonate solution is added to the slurry while stirring to obtain a solid product, and the solid product is filtered and dried to obtain an antistatic agent; the rest is the same as in Example 4.

[0082] Example 7

[0083] The difference from Example 4 is that the antistatic agent is prepared by the following steps: 0.6 kg of zinc oxide and 0.05 kg of polyetherimide are uniformly dispersed in a mixture of 0.01 kg of silane coupling agent and 0.6 kg of calcium acetate solution to form a slurry, and 2.6 kg of sodium carbonate solution is added to the slurry while stirring to obtain a solid product, and the solid product is filtered and dried to obtain an antistatic agent; the rest is the same as Example 4.

[0084] Example 8

[0085] The difference from Example 6 is that the method for preparing a multifunctional polyethylene breathable film comprises the following steps: adding the prepared breathable masterbatch, antistatic masterbatch, antibacterial masterbatch, flame retardant masterbatch, linear low-density polyethylene, metallocene linear low-density polyethylene, low-density polyethylene and color masterbatch according to the formula amount into a mixer for mixing, and then melt extruding, the extrusion head temperature is 175-185°C, and the extrusion rate is 580kg / h; followed by blow molding, pulling, stretching film forming, and corona treatment, the pulling speed is 20m / min, and the stretch ratio is 5.5; the rest is the same as Example 6.

[0086] Comparative Example

[0087] Comparative Example 1

[0088] The difference from Example 6 is that the antistatic masterbatch is obtained by mixing linear low-density polyethylene and polyetherimide in a weight ratio of 1:0.4, and the amount of the antistatic masterbatch and the other components are the same as those in Example 6.

[0089] Comparative Example 2

[0090] The difference from Example 6 is that the antistatic agent is prepared by the following steps: 0.5 kg of zinc oxide is uniformly dispersed in 0.04 kg of silane coupling agent to obtain the antistatic agent; the rest are the same as Example 6.

[0091] Comparative Example 3

[0092] The difference from Example 6 is that an equal amount of linear low-density polyethylene is used to replace the antistatic masterbatch, and the rest is the same as Example 6.

[0093] Comparative Example 4

[0094] The difference from Example 6 is that in the flame retardant masterbatch, an equal amount of bismaleimide is replaced by a whitened red phosphorus flame retardant, and the rest is the same as Example 6.

[0095] Performance testing

[0096] The breathable membranes of Examples 1-8 and Comparative Examples 1-4 were tested for air permeability using a Wang Yan air permeability tester model EG02-5 / 6-1.2MR. The results are recorded in Table 1.

[0097] The breathable membranes of Examples 1-8 and Comparative Examples 1-4 were tested for surface resistance using a surface resistance meter, and fire ratings were tested according to the U.S. UL94 fire protection standard. The antibacterial rates against Escherichia coli and Staphylococcus aureus were tested according to GB / T 31402-2015 "Test Method for Antibacterial Properties of Plastic Surfaces." The results are shown in Table 1.

[0098] The breathable films of Examples 1-8 and Comparative Examples 1-4 were tested for maximum tensile strength and maximum elongation according to ISO 1184 "Determination of tensile properties of plastic films". The breathable films obtained in Examples 1-8 had a maximum longitudinal tensile strength greater than 25 N, a maximum transverse tensile strength greater than 4 N, a maximum longitudinal elongation greater than 60%, and a maximum transverse elongation greater than 450%. The results of Example 6 and Comparative Examples 1-4 are shown in Table 2.

[0099] Table 1

[0100] Table 2

[0101] In combination with Examples 1-8 and Tables 1 and 2, it can be seen that the breathable membrane made using the raw material ratio and preparation method of the present application not only has good air permeability and mechanical properties, but also has excellent antistatic, flame retardant and antibacterial functions, which can meet the different functional requirements of users for breathable membranes.

[0102] Combining Example 6 and Comparative Examples 1-3 with Tables 1 and 2, it can be seen that the antistatic masterbatch prepared by the raw material components and preparation method of the present application can not only significantly improve the antistatic performance of the product, but also help improve the flame retardant and antibacterial properties of the product, improve the antibacterial effect of the breathable film on Escherichia coli and Staphylococcus aureus, and give the breathable film better longitudinal maximum tensile force, transverse maximum tensile force, longitudinal maximum elongation and transverse maximum elongation, and the mechanical properties of the breathable film are good. This is because zinc oxide and polyetherimide are uniformly dispersed in the mixture of the silane coupling agent and the calcium source solution. The silane coupling agent can effectively improve the compatibility between the raw material components and improve their uniformity. The carbonate ions in the carbonate solution added subsequently combine with the calcium ions in the calcium source solution, entraining the zinc oxide and polyetherimide during the stirring process and forming calcium carbonate precipitation; the obtained antistatic agent not only has excellent antistatic effect, but can also be used as a filler to reinforce the product with the antistatic masterbatch, while promoting uniform dispersion between the components, improving the compositeness between the components, and improving the mechanical properties of the product. Zinc oxide not only has good antistatic effect, but also has certain antibacterial effect. It can be further combined with antibacterial masterbatch to achieve excellent antibacterial effect. Polyetherimide also has certain flame retardancy and can be combined with flame retardant masterbatch to improve the flame retardant performance of the product.

[0103] Combining Example 6 and Comparative Example 4 with Table 1, it can be seen that using bismaleimide as a flame retardant can effectively avoid the problem of poor dispersibility of inorganic flame retardants in organic systems, and can also assist the antistatic masterbatch in synergistically improving the antistatic performance of the product.

[0104] 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 multifunctional polyethylene breathable membrane, characterized in that: The invention comprises the following raw materials in weight percentage: 15%-30% of linear low-density polyethylene, 15%-40% of metallocene linear low-density polyethylene, 5%-10% of low-density polyethylene, 30%-50% of breathable masterbatch, 2%-10% of antistatic masterbatch, 2%-10% of antibacterial masterbatch, 5-10% of flame-retardant masterbatch and 2-5% of color masterbatch.

2. The multifunctional polyethylene breathable membrane according to claim 1, characterized in that: The breathable masterbatch comprises the following raw materials in percentage by weight: 40-80% polyethylene, 40-60% calcium carbonate, 0.5%-2% antioxidant, 0.3-1% lubricant, and 1%-2.5% anti-yellowing agent.

3. The multifunctional polyethylene breathable membrane according to claim 1, characterized in that: The antistatic masterbatch comprises the following raw materials in percentage by weight: 40-80% polyethylene, 30-60% antistatic agent, 0.5%-2% antioxidant, 0.3-1% lubricant, and 1%-2.5% anti-yellowing agent.

4. The multifunctional polyethylene breathable membrane according to claim 1, characterized in that: The antibacterial masterbatch comprises the following raw materials in percentage by weight: 40-80% polyethylene, 20-50% calcium carbonate, 2-10% antibacterial agent, 0.5%-2% antioxidant, 0.3-1% lubricant, and 1%-2.5% anti-yellowing agent.

5. The multifunctional polyethylene breathable membrane according to claim 1, characterized in that: The flame retardant masterbatch comprises the following raw materials in percentage by weight: 40-80% polyethylene, 15-50% bismaleimide, 0.5-2% antioxidant, 0.3-1% lubricant, and 1-2.5% anti-yellowing agent.

6. The multifunctional polyethylene breathable membrane according to any one of claims 2 to 5, characterized in that: The polyethylene comprises 15%-40% of linear low-density polyethylene, 10%-20% of metallocene linear low-density polyethylene, and 5%-15% of low-density polyethylene.

7. The multifunctional polyethylene breathable membrane according to claim 2 or 4, characterized in that: The particle size of the calcium carbonate is 1 μm-4 μm.

8. The multifunctional polyethylene breathable membrane according to claim 3, characterized in that: The antistatic agent is prepared by the following steps: zinc oxide and polyetherimide are uniformly dispersed in a mixture of a silane coupling agent and a calcium source solution to prepare a slurry, a carbonate solution is added to the slurry while stirring to obtain a solid product, and the solid product is filtered and dried to obtain the antistatic agent.

9. The multifunctional polyethylene breathable membrane according to claim 4, characterized in that: The antibacterial agent includes tea polyphenols and / or clove essential oil.

10. The method for preparing a multifunctional polyethylene breathable membrane according to any one of claims 1 to 9, characterized in that: The following steps are involved: According to the formula, linear low-density polyethylene, metallocene linear low-density polyethylene, low-density polyethylene, breathable masterbatch, antistatic masterbatch, antibacterial masterbatch, flame-retardant masterbatch and color masterbatch are mixed, melt-extruded, blow-molded, pulled, stretched into film, and corona treated.

Images