Polystyrene-containing breathable film and preparation method thereof

Abstract

The invention belongs to the technical field of gas-permeable membranes, and particularly relates to a gas-permeable membrane containing polystyrene and a preparation method of the gas-permeable membrane. The breathable film comprises the following components in parts by weight: 30-40 parts of high density polyethylene; 20 to 30 parts of low density polyethylene; 15 to 20 parts of polystyrene; 5 to 10 parts of polyvinylpyrrolidone; 6-8 parts of an antibacterial modifier; 12 to 15 parts of filler; 1-2 parts of a coupling agent; 3-5 parts of an antioxidant; the antibacterial modifier and the filler are added into the components of the breathable film, so that the multifunctionality of the breathable film is realized, and the prepared breathable film has good mechanical properties, breathability and waterproofness, particularly has excellent antibacterial and flame-retardant properties, and can meet different use requirements.

Description

Technical Field

[0001] The invention belongs to the technical field of breathable films, and in particular relates to a breathable film containing polystyrene and a preparation method thereof. Background Art

[0002] Breathable membrane is a plastic film with excellent air permeability, which can allow gas to pass through while blocking liquids and solid particles. The raw materials for preparing breathable membranes include polyolefin polymer materials such as polyethylene resin and polypropylene resin. The breathable membrane made of polyethylene as the substrate is a polyethylene breathable membrane, which has many advantages such as good softness and air permeability, strong chemical stability, high tensile strength, and good processing performance. Therefore, it is widely used in medical (used in the production of medical protective masks, medical protective clothing, etc.), daily necessities (used in the production of female sanitary napkins, baby diapers, etc.), electronics and electrical (used as electronic screen protectors, etc.), food packaging and other fields; in the preparation process of polyethylene breathable membrane, calcium carbonate is usually added, and micropores are formed after cast / blow molding and stretching process to achieve breathable and waterproof functions. With the continuous improvement of living standards and the improvement of living conditions, polyethylene breathable membranes with single breathable and waterproof functions can no longer meet people's needs.

[0003] Chinese patent application with application number CN202311503565.7 discloses an antistatic breathable membrane and a preparation method thereof. The raw materials for preparing the breathable membrane include, by weight: 1-15 parts of polyvinyl alcohol-polyethylene copolymer, 1-15 parts of polyether-polystyrene copolymer, 5-25 parts of low-density polyethylene, 3-15 parts of high-density polyethylene, 10-30 parts of metallocene polyethylene, 40-60 parts of calcium carbonate, 0.1-1 parts of antioxidant, 0.1-1 parts of coupling agent, and 2-5 parts of compatibilizer. The components cooperate with each other and are blended by twin-screw extrusion to achieve dispersion of antistatic components to obtain an antistatic breathable membrane, but the breathable performance of the breathable membrane is insufficient; Chinese patent application with application number CN202311557083.X discloses a waterproof breathable membrane and a preparation method thereof, including a non-woven fabric and a bulking agent disposed on the non-woven fabric. Polytetrafluoroethylene membrane, expanded polytetrafluoroethylene membrane includes the following raw materials in parts by mass: 25-35 parts of expanded polytetrafluoroethylene, 15-20 parts of polystyrene, 10-15 parts of polyvinyl pyrrolidone, 30-40 parts of 2-hydroxy N, N-dimethylamide, 0.2-0.6 parts of coupling agent, 4-6 parts of filler, 14 parts of sodium hexametaphosphate, 13 parts of sodium methylene dinaphthalene sulfonate, and 35 parts of pore-forming agent. The prepared waterproof and breathable membrane has the advantages of strong air permeability, heat dissipation performance, corrosion resistance and good mechanical properties. Although sodium hexametaphosphate as an additive plays a flame retardant role and improves the fire resistance of the material, and sodium methylene dinaphthalene sulfonate as an additive improves the antistatic and antibacterial properties of the material, the fire resistance and antibacterial properties of the prepared waterproof and breathable membrane are insufficient. Therefore, it is necessary to develop a multifunctional polyethylene breathable membrane to meet market demand. Summary of the invention

[0004] The purpose of the present invention is to provide a breathable membrane containing polystyrene and a preparation method thereof in view of the deficiencies in the prior art. The multifunctionality of the breathable membrane is achieved by adding an antibacterial modifier and a filler to the breathable membrane components. The prepared breathable membrane has good mechanical properties, air permeability, and waterproof properties, especially excellent antibacterial and flame retardant properties, and can meet different usage requirements.

[0005] The technical solution adopted by the present invention to achieve the above-mentioned purpose is: A breathable film containing polystyrene, the breathable film comprises the following components in parts by weight: 30-40 parts of high-density polyethylene; 20-30 parts of low-density polyethylene; 15-20 parts of polystyrene; 5-10 parts of polyvinyl pyrrolidone; 6-8 parts of antibacterial modifier; 12-15 parts of filler; 1-2 parts of coupling agent; and 3-5 parts of antioxidant.

[0006] Furthermore, the filler is composed of nano calcium carbonate and composite diatomaceous earth in a mass ratio of 1:1-2.

[0007] Furthermore, the coupling agent is any one of propyltrimethoxysilane, γ-aminopropyltriethoxysilane, and vinyltriethoxysilane, or a mixture of several of them.

[0008] Furthermore, the antioxidant is any one of antioxidant 1010, antioxidant 168, and antioxidant 1076, or a mixture of several of them.

[0009] In the technical solution of the present invention, the preparation method of the composite diatomite is: adding diatomite to a reaction container containing ethanol, dispersing it evenly, adding an antibacterial modifier, stirring for 5-6 hours at room temperature, removing the ethanol, and obtaining the composite diatomite.

[0010] Furthermore, the mass ratio of the diatomaceous earth, the antibacterial modifier and the ethanol is 1:0.1-0.2:10-15; and the particle size of the diatomaceous earth is 200-300 meshes.

[0011] In the technical scheme of the present invention, the antibacterial modifiers described in the preparation methods of the breathable membrane component and the composite diatomaceous earth are prepared by reacting 4-chlorophenylethanol as a raw material with dimethylaminoethyl methacrylate, dichlorothionyl, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 5,5-dimethylhydantoin and sodium hypochlorite in sequence.

[0012] Furthermore, the preparation method of the antibacterial modifier is: Step 1: Add 4-chlorophenethyl alcohol and dimethylaminoethyl methacrylate to a reaction vessel containing acetonitrile, mix well, raise the temperature to 75-80°C, stir and react for 10-11 hours, then lower the temperature to 35-40°C, add triethylamine, mix well, add dichlorothionyl dropwise, and after the addition is complete, continue stirring and reacting for 8-9 hours to obtain intermediate I; Step 2: Add intermediate I and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to a reaction vessel containing N,N-dimethylformamide, mix well, increase the temperature to 90-95°C, and stir the reaction for 9-10 hours to obtain intermediate II; Step 3: Add 5,5-dimethylhydantoin and potassium hydroxide to a water-containing reaction vessel, mix evenly, add intermediate II, raise the temperature to 70-75°C, stir and react for 6-7h, then add sodium hypochlorite, continue stirring and react for 8-9h to obtain an antibacterial modifier, the structural formula of the antibacterial modifier is: .

[0013] Furthermore, the molar ratio of 4-chlorophenethyl alcohol, dimethylaminoethyl methacrylate, dithionyl chloride and triethylamine in step 1 is 1:1-1.1:1.1-1.2:1.3-1.4.

[0014] Furthermore, in step 2, the molar ratio of the intermediate I to 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 1:1.1-1.2.

[0015] Furthermore, in step 3, the molar ratio of intermediate II, 5,5-dimethylhydantoin, potassium hydroxide and sodium hypochlorite is 1:1-1.1:1-1.1:1-1.1.

[0016] The present invention also provides a method for preparing a breathable film containing polystyrene, comprising the following steps: uniformly mixing high-density polyethylene, low-density polyethylene, polystyrene, polyvinyl pyrrolidone, antibacterial modifier, filler, coupling agent and antioxidant according to mass ratio, adding the mixture into a twin-screw extruder, extruding and granulating the mixture, and then blowing the film and longitudinally stretching the mixture to obtain a breathable film.

[0017] Furthermore, the extrusion temperature of the twin-screw extruder is 190-210° C.; the longitudinal stretching temperature is 80-90° C., and the longitudinal stretching ratio is 4-5 times.

[0018] The present invention has the following beneficial effects: The antibacterial modifier prepared by the present invention contains antibacterial quaternary ammonium salt groups, antibacterial chlorodimethylhydantoin groups and flame retardant DOPO groups, and these groups give the antibacterial modifier good antibacterial and flame retardant effects; the antibacterial modifier reacts with diatomaceous earth, and the adsorption of diatomaceous earth is used to obtain composite diatomaceous earth, and nano calcium carbonate and composite diatomaceous earth are compounded as fillers of breathable membranes. During the processing of the breathable membranes, nano calcium carbonate forms micropores, and the composite diatomaceous earth with a microporous structure can increase the microporous structure of the breathable membrane, thereby helping to improve the breathable membrane. In addition, the antibacterial modifier adsorbed in the composite diatomite can also synergize with the antibacterial modifier in the breathable membrane component to greatly enhance the antibacterial and flame retardant properties of the breathable membrane. The present invention adopts the combination of composite diatomite and antibacterial modifier. Compared with the composite diatomite and common quaternary ammonium antibacterial agent (methyltributylammonium chloride), the former can significantly improve the antibacterial and flame retardant properties of the breathable membrane. Since the antibacterial modifier contains multiple hydrophobic rigid benzene ring structures, the combination of composite diatomite and antibacterial modifier can also help improve the mechanical and waterproof properties of the breathable membrane.

[0019] The present invention achieves the multifunctionality of the breathable membrane by adding an antibacterial modifier and a filler to the breathable membrane components. The prepared breathable membrane has good mechanical properties, air permeability, and waterproof properties, especially excellent antibacterial and flame retardant properties, and can meet different usage requirements. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described in combination with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; the technical features designed in different implementation modes of the present invention described below can be combined with each other as long as they do not conflict with each other; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0021] In the technical scheme of the present invention, the chemical reagents used are all commercially available, among which high-density polyethylene is purchased from Zhejiang Jinbei Guang New Materials Co., Ltd. (brand name HD5502GA); low-density polyethylene is purchased from Zhejiang Jinbei Guang New Materials Co., Ltd. (brand name 868-000); polystyrene CAS No. 9003-53-6; polyvinyl pyrrolidone CAS No. 9003-39-8; nano calcium carbonate CAS No. 471-34-1; propyl trimethoxy silane CAS No. 1067-25-0; γ-aminopropyl triethoxy silane CAS No. 919-30-2; vinyl triethoxy silane CAS No. 78-08-0; antioxidant 1010 CAS No. 6683-19-8; antioxidant 168 CAS No. 31570-04-4; antioxidant 1076 CAS No. 2082-79-3; Diatomaceous earth CAS No. 61790-53-2; 4-Chlorophenylethanol CAS No. 1875-88-3; Dimethylaminoethyl methacrylate CAS No. 2867-47-2; Triethylamine CAS No. 121-44-8; Thionyl chloride CAS No. 7719-09-7; 9,10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) CAS No. 35948-25-5; 5,5-Dimethylhydantoin CAS No. 77-71-4; Potassium hydroxide CAS No. 1310-58-3; Sodium hypochlorite CAS No. 7681-52-9; Acetonitrile CAS No. 75-05-8; Ether CAS No. 60-29-7; N,N-Dimethylformamide CAS No. 68-12-2; Ethanol CAS No. 64-17-5.

[0022] The antibacterial modifier in the preparation method of the breathable membrane component and the composite diatomite of the present invention is prepared by reacting 4-chlorophenylethanol as a raw material with dimethylaminoethyl methacrylate, dichlorothionyl, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 5,5-dimethylhydantoin and sodium hypochlorite in sequence; Embodiment 1 This embodiment provides a method for preparing an antibacterial modifier.

[0023] Step 1: Add 15.7g 4-chlorophenethyl alcohol and 16.5g dimethylaminoethyl methacrylate to a reaction vessel containing 500mL acetonitrile, mix well, raise the temperature to 80°C, stir and react for 10h, then lower the temperature to 40°C, add 13.2g triethylamine, mix well, drop 13.1g thionyl chloride, after the dropwise addition is complete, continue to stir and react for 9h, after the reaction is complete, remove acetonitrile, add ether and stir, filter, wash the solid with ether, and dry to obtain 24.9g intermediate I; the molar ratio of 4-chlorophenethyl alcohol, dimethylaminoethyl methacrylate, thionyl chloride and triethylamine is 1:1.05:1.1:1.3; The synthetic route of step one is: ; Intermediate I: ESI (m / z): 333.3 [M+H] + , 1 H-NMR (600 MHz, DMSO-d 6 , δppm): 7.20 (d, J=8.5Hz, 2H), 7.02 (d, J=8.5Hz, 2H), 6.40-6.48 (m, 2H), 4.59-4. 66 (m, 2H), 3.71-3.76 (m, 8H), 3.52-3.60 (m, 2H), 2.83-2.89 (m, 2H), 2.01 (s, 3H).

[0024] Step 2: Add 24.5 g of intermediate I and 17.5 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) to a reaction vessel containing 400 mL of N,N-dimethylformamide, mix well, raise the temperature to 95°C, stir and react for 9 hours, and after the reaction is completed, add ether for precipitation, filter, wash the solid with ether, and dry to obtain 34.5 g of intermediate II; the molar ratio of intermediate I to 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 1:1.1; The synthetic route of step 2 is: ; Intermediate II: ESI (m / z): 549.4 [M+H] + , 1 H-NMR (600 MHz, DMSO-d 6, δppm): 7.75-8.00 (m, 2H), 7.41-7.50 (m, 4H), 7.30-7.36 (m, 2H), 7.22 (d, J=8.5Hz, 2H), 7.01 (d, J=8.5Hz, 2H), 4 .52-4.60 (m, 2H), 3.70-3.78 (m, 8H), 3.53-3.60 (m, 2H), 2.77-2.85 (m, 3H), 2.45-2.51 (m, 2H), 1.17-1.23 (m, 3H).

[0025] Step 3: Add 8.3 g of 5,5-dimethylhydantoin and 3.8 g of potassium hydroxide to a reaction container containing 350 mL of water, mix well, add 34.0 g of intermediate II, raise the temperature to 75 ° C, stir and react for 7 hours, then add 5.1 g of sodium hypochlorite, continue to stir and react for 8 hours, after the reaction is completed, remove water, add ether and stir, filter, wash the solid with ether, and dry to obtain 35.2 g of antibacterial modifier; the molar ratio of intermediate II, 5,5-dimethylhydantoin, potassium hydroxide, and sodium hypochlorite is 1:1.05:1.1:1.1; The synthetic route of step 3 is: ; Antibacterial modifier: ESI (m / z): 675.6 [M+H] + , 1 H-NMR (600 MHz, DMSO-d 6 , δppm): 7.76-8.00 (m, 2H), 7.41-7.52 (m, 4H), 7.29-7.36 (m, 2H), 7.20 (d, J=8.5Hz, 2H), 7.00 (d, J=8.5Hz, 2H), 4.51-4.58 (m, 2H), 3.72 (s, 6H), 3.52-3.60 (m, 2H), 3.37-3.42 (m, 2H), 2.77-2.83 (m, 3H), 2.46-2.53 (m, 2H), 1.18-1.23 (m, 3H), 1.80 (s, 6H).

[0026] Embodiment 2 A breathable film containing polystyrene comprises the following components in parts by weight: 40 parts of high-density polyethylene; 25 parts of low-density polyethylene; 20 parts of polystyrene; 10 parts of polyvinyl pyrrolidone; 8 parts of antibacterial modifier; 15 parts of filler; 2 parts of coupling agent; and 5 parts of antioxidant.

[0027] The filler is composed of nano calcium carbonate and composite diatomaceous earth in a mass ratio of 1:2; the coupling agent is propyl trimethoxy silane; and the antioxidant is antioxidant 1010.

[0028] The preparation method of composite diatomite is as follows: adding diatomite into a reaction container containing ethanol, dispersing it evenly, adding an antibacterial modifier, stirring for 6 hours at room temperature, removing the ethanol, and obtaining the composite diatomite; the mass ratio of diatomite, antibacterial modifier, and ethanol is 1:0.2:15; and the particle size of the diatomite is 300 meshes.

[0029] A method for preparing a breathable film containing polystyrene comprises the following steps: uniformly mixing high-density polyethylene, low-density polyethylene, polystyrene, polyvinyl pyrrolidone, an antibacterial modifier, a filler, a coupling agent and an antioxidant according to a mass ratio, adding the mixture into a twin-screw extruder, extruding and granulating the mixture, and then subjecting the mixture to film blowing and longitudinal stretching to obtain a breathable film; the extrusion temperature of the twin-screw extruder is 200°C; the longitudinal stretching temperature is 90°C, and the longitudinal stretching ratio is 5 times.

[0030] Embodiment 3 A breathable film containing polystyrene, the breathable film comprises the following components in parts by weight: 35 parts of high-density polyethylene; 30 parts of low-density polyethylene; 18 parts of polystyrene; 8 parts of polyvinyl pyrrolidone; 7 parts of antibacterial modifier; 13 parts of filler; 1.5 parts of coupling agent; and 4 parts of antioxidant.

[0031] The filler is composed of nano calcium carbonate and composite diatomaceous earth in a mass ratio of 1:1.5; the coupling agent is gamma-aminopropyltriethoxysilane; and the antioxidant is antioxidant 168.

[0032] The preparation method of composite diatomite is as follows: adding diatomite into a reaction container containing ethanol, dispersing it evenly, adding an antibacterial modifier, stirring for 5 hours at room temperature, removing the ethanol, and obtaining the composite diatomite; the mass ratio of diatomite, antibacterial modifier, and ethanol is 1:0.1:10; and the particle size of the diatomite is 200 meshes.

[0033] A method for preparing a breathable film containing polystyrene comprises the following steps: uniformly mixing high-density polyethylene, low-density polyethylene, polystyrene, polyvinyl pyrrolidone, an antibacterial modifier, a filler, a coupling agent and an antioxidant according to a mass ratio, adding the mixture into a twin-screw extruder, extruding and granulating the mixture, and then subjecting the mixture to film blowing and longitudinal stretching to obtain a breathable film; the extrusion temperature of the twin-screw extruder is 210°C; the longitudinal stretching temperature is 80°C, and the longitudinal stretching ratio is 4 times.

[0034] Embodiment 4 A breathable film containing polystyrene, the breathable film comprises the following components in parts by weight: 30 parts of high-density polyethylene; 20 parts of low-density polyethylene; 15 parts of polystyrene; 5 parts of polyvinyl pyrrolidone; 6 parts of antibacterial modifier; 12 parts of filler; 1 part of coupling agent; and 3 parts of antioxidant.

[0035] The filler is composed of nano calcium carbonate and composite diatomaceous earth in a mass ratio of 1:1; the coupling agent is vinyl triethoxy silane; and the antioxidant is antioxidant 1076.

[0036] The preparation method of composite diatomite is as follows: adding diatomite to a reaction container containing ethanol, dispersing it evenly, adding an antibacterial modifier, stirring for 5.5 hours at room temperature, removing the ethanol, and obtaining the composite diatomite; the mass ratio of diatomite, antibacterial modifier, and ethanol is 1:0.15:13; and the particle size of the diatomite is 250 mesh.

[0037] A method for preparing a breathable film containing polystyrene comprises the following steps: uniformly mixing high-density polyethylene, low-density polyethylene, polystyrene, polyvinyl pyrrolidone, an antibacterial modifier, a filler, a coupling agent and an antioxidant according to a mass ratio, adding the mixture into a twin-screw extruder, extruding and granulating the mixture, and then subjecting the mixture to film blowing and longitudinal stretching to obtain a breathable film; the extrusion temperature of the twin-screw extruder is 190° C.; the longitudinal stretching temperature is 85° C., and the longitudinal stretching ratio is 4.5 times.

[0038] Embodiment 5 A breathable film containing polystyrene comprises the following components in parts by weight: 36 parts of high-density polyethylene; 23 parts of low-density polyethylene; 16 parts of polystyrene; 6 parts of polyvinyl pyrrolidone; 8 parts of antibacterial modifier; 12 parts of filler; 2 parts of coupling agent; and 4 parts of antioxidant.

[0039] The filler is composed of nano calcium carbonate and composite diatomaceous earth in a mass ratio of 1:2; the coupling agent is vinyl triethoxy silane; and the antioxidant is antioxidant 1010.

[0040] The preparation method of composite diatomite is as follows: adding diatomite into a reaction container containing ethanol, dispersing it evenly, adding an antibacterial modifier, stirring for 6 hours at room temperature, removing the ethanol, and obtaining the composite diatomite; the mass ratio of diatomite, antibacterial modifier, and ethanol is 1:0.2:10; and the particle size of the diatomite is 200 meshes.

[0041] A method for preparing a breathable film containing polystyrene comprises the following steps: uniformly mixing high-density polyethylene, low-density polyethylene, polystyrene, polyvinyl pyrrolidone, an antibacterial modifier, a filler, a coupling agent and an antioxidant according to a mass ratio, adding the mixture into a twin-screw extruder, extruding and granulating the mixture, and then subjecting the mixture to film blowing and longitudinal stretching to obtain a breathable film; the extrusion temperature of the twin-screw extruder is 200°C; the longitudinal stretching temperature is 80°C, and the longitudinal stretching ratio is 5 times.

[0042] Comparative Example 1 Compared with Example 2, the filler in this comparative example is composed of nano calcium carbonate and diatomaceous earth.

[0043] A breathable film containing polystyrene comprises the following components in parts by weight: 40 parts of high-density polyethylene; 25 parts of low-density polyethylene; 20 parts of polystyrene; 10 parts of polyvinyl pyrrolidone; 8 parts of antibacterial modifier; 15 parts of filler; 2 parts of coupling agent; and 5 parts of antioxidant.

[0044] The filler is composed of nano calcium carbonate and diatomaceous earth in a mass ratio of 1:2; the coupling agent is propyl trimethoxy silane; and the antioxidant is antioxidant 1010.

[0045] The preparation method of a breathable film containing polystyrene is the same as that of Example 2.

[0046] Comparative Example 2 Compared with Example 2, this comparative example replaces the antibacterial modifier in the breathable membrane component with methyltributylammonium chloride.

[0047] A breathable film containing polystyrene comprises the following components in parts by weight: 40 parts of high-density polyethylene; 25 parts of low-density polyethylene; 20 parts of polystyrene; 10 parts of polyvinyl pyrrolidone; 8 parts of methyltributylammonium chloride; 15 parts of filler; 2 parts of coupling agent; and 5 parts of antioxidant.

[0048] The filler is composed of nano calcium carbonate and composite diatomaceous earth in a mass ratio of 1:2; the coupling agent is propyl trimethoxy silane; and the antioxidant is antioxidant 1010.

[0049] The preparation methods of the composite diatomite and a breathable membrane containing polystyrene are the same as those in Example 2.

[0050] Comparative Example 3 Compared with Example 2, this comparative example has the following features: the antibacterial modifier in the breathable membrane component is replaced by methyltributylammonium chloride, and the filler is composed of nano-calcium carbonate and diatomaceous earth.

[0051] A breathable film containing polystyrene comprises the following components in parts by weight: 40 parts of high-density polyethylene; 25 parts of low-density polyethylene; 20 parts of polystyrene; 10 parts of polyvinyl pyrrolidone; 8 parts of methyltributylammonium chloride; 15 parts of filler; 2 parts of coupling agent; and 5 parts of antioxidant.

[0052] The filler is composed of nano calcium carbonate and diatomaceous earth in a mass ratio of 1:2; the coupling agent is propyl trimethoxy silane; and the antioxidant is antioxidant 1010.

[0053] The preparation method of a breathable film containing polystyrene is the same as that of Example 2.

[0054] Performance Testing The performance tests were conducted on the breathable membranes prepared in Examples 2 to 5 and Comparative Examples 1 to 3, wherein the tensile strength and elongation at break were in accordance with the GB / T 528-2009 standard; the moisture permeability was tested by a moisture permeability tester on the breathable membrane sample; the air permeability was tested by an air permeability tester to determine the Gurley value of the membrane, the test pressure was 8.5 kPa, and the test area was 645.2 mm 2 The smaller the Gurley value, the higher the air permeability of the breathable membrane; the hydrostatic pressure resistance is tested with reference to GB / T 4744-2013 standard; the antibacterial performance is tested with reference to GB / T2591-2003 standard; the flame retardant performance is tested by the limiting oxygen index method; the test results are shown in Table 1 below.

[0055] Table 1 Performance test results From the results in Table 1, it can be seen that the tensile strength, elongation at break, moisture permeability, hydrostatic pressure resistance, antibacterial rate of Staphylococcus aureus and Escherichia coli, and limiting oxygen index of the breathable membranes of Examples 2 to 5 of the present invention are higher than those of Comparative Examples 1 to 3, and the Gurley value is lower than that of Comparative Examples 1 to 3, indicating that the breathable membranes prepared by Examples 2 to 5 of the present invention have good mechanical properties, air permeability, and waterproof properties, especially excellent antibacterial and flame retardant properties; by comparing Example 2 with Comparative Examples 1 to 3, it can be seen that fillers and antibacterial modifiers composed of nano-calcium carbonate and composite diatomaceous earth are added to the breathable membrane components of Example 2 of the present invention, wherein the antibacterial modifier adsorbed in the composite diatomaceous earth can also synergistically act with the antibacterial modifier in the breathable membrane component, greatly enhancing the antibacterial and flame retardant properties of the breathable membrane, and the microporous structure of the composite diatomaceous earth also helps to improve the air permeability of the breathable membrane.

[0056] It should be noted that, in this article, terms such as "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0057] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A breathable film containing polystyrene, characterized in that: The breathable membrane comprises the following components by weight: 30-40 parts of high-density polyethylene; 20-30 parts of low-density polyethylene; 15-20 parts of polystyrene; 5-10 parts of polyvinyl pyrrolidone; 6-8 parts of antibacterial modifier; 12-15 parts of filler; 1-2 parts of coupling agent; and 3-5 parts of antioxidant. The filler is composed of nano-calcium carbonate and composite diatomite in a mass ratio of 1:1-2; the preparation method of the composite diatomite is: adding diatomite to a reaction container containing ethanol, dispersing it evenly, adding an antibacterial modifier, stirring for 5-6 hours at room temperature, and removing the ethanol to obtain the composite diatomite; The antibacterial modifiers described in the preparation methods of the breathable membrane components and the composite diatomaceous earth are prepared by reacting 4-chlorophenylethanol as a raw material with dimethylaminoethyl methacrylate, dichlorothionyl, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 5,5-dimethylhydantoin and sodium hypochlorite in sequence.

2. A breathable film containing polystyrene according to claim 1, characterized in that: The preparation method of the antibacterial modifier is: Step 1: Add 4-chlorophenethyl alcohol and dimethylaminoethyl methacrylate to a reaction vessel containing acetonitrile, mix well, raise the temperature to 75-80°C, stir and react for 10-11 hours, then lower the temperature to 35-40°C, add triethylamine, mix well, add dichlorothionyl dropwise, and after the addition is complete, continue stirring and reacting for 8-9 hours to obtain intermediate I; Step 2: Add intermediate I and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to a reaction vessel containing N,N-dimethylformamide, mix well, increase the temperature to 90-95°C, and stir the reaction for 9-10 hours to obtain intermediate II; Step 3: Add 5,5-dimethylhydantoin and potassium hydroxide to a reaction vessel containing water, mix well, add intermediate II, increase the temperature to 70-75°C, stir and react for 6-7h, then add sodium hypochlorite, continue stirring and react for 8-9h to obtain an antibacterial modifier.

3. A breathable film containing polystyrene according to claim 2, characterized in that: The molar ratio of 4-chlorophenethyl alcohol, dimethylaminoethyl methacrylate, thionyl chloride and triethylamine in step 1 is 1:1-1.1:1.1-1.2:1.3-1.

4.

4. A breathable film containing polystyrene according to claim 2, characterized in that: In step 2, the molar ratio of the intermediate I to 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 1:1.1-1.

2.

5. A breathable film containing polystyrene according to claim 2, characterized in that: In step 3, the molar ratio of intermediate II, 5,5-dimethylhydantoin, potassium hydroxide and sodium hypochlorite is 1:1-1.1:1-1.1:1-1.

1.

6. A breathable film containing polystyrene according to claim 1, characterized in that: In the preparation method of composite diatomaceous earth, the mass ratio of diatomaceous earth, antibacterial modifier and ethanol is 1:0.1-0.2:10-15; the particle size of the diatomaceous earth is 200-300 meshes.

7. A breathable film containing polystyrene according to claim 1, characterized in that: The coupling agent is any one of propyltrimethoxysilane, γ-aminopropyltriethoxysilane, and vinyltriethoxysilane, or a mixture of several of them.

8. A breathable film containing polystyrene according to claim 1, characterized in that: The antioxidant is any one of antioxidant 1010, antioxidant 168, and antioxidant 1076, or a mixture of several of them.

9. A method for preparing a breathable film containing polystyrene according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: mixing high-density polyethylene, low-density polyethylene, polystyrene, polyvinyl pyrrolidone, antibacterial modifier, filler, coupling agent and antioxidant uniformly according to mass ratio, adding the mixture into a twin-screw extruder, extruding granulation, and then blowing film and longitudinally stretching to obtain a breathable film.

10. The method for preparing a breathable film containing polystyrene according to claim 9, characterized in that: The extrusion temperature of the twin-screw extruder is 190-210° C.; the longitudinal stretching temperature is 80-90° C., and the longitudinal stretching ratio is 4-5 times.

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