Non-polyolefin breathable film with high microbial barrier property and high strength as well as preparation method and application of non-polyolefin breathable film

Abstract

The invention relates to the technical field of high polymer materials, in particular to a non-polyolefin breathable film with high microbial barrier property and high strength as well as a preparation method and application of the non-polyolefin breathable film. The present invention relates to a non-polyolefin film containing a hydrophobic agent, a base film, and a polyamide at least partially located on both sides of the base film, the non-polyolefin film having a Gurley air permeability of not more than 10 [mu] m / (Pa.s) and not less than 1.5 [mu] m / (Pa.s) at an average pressure difference of 1.23 kPa; the LRV of the non-polyolefin film is not less than 3; wherein the base film is made of non-polyolefin. The non-polyolefin film not only has proper air permeability and higher strength, but also unexpectedly has the microorganism barrier grade LRV of not less than 3, the microorganism barrier property of the non-polyolefin film is remarkably improved, and an unexpected technical effect is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and in particular to a non-polyolefin breathable film with high microbial barrier and high strength, and a preparation method and application thereof. Background Art

[0002] Breathable film is a functional film material with a wide range of applications. It has important applications in the fields of medical packaging materials, medical protective clothing, building waterproofing and water treatment. In the field of medical packaging, breathable film should ensure good microbial barrier properties. In addition, it also needs to have high air permeability and high strength. High air permeability is to be better suitable for ethylene oxide sterilization, and high strength is to prevent packaging rupture and medical device failure during packaging, transportation and storage. However, usually, these requirements are contradictory. In order to make the air permeability better, the film microstructure is usually looser, which easily reduces the strength and microbial barrier properties. Therefore, the breathable film should have appropriate air permeability to ensure good strength and microbial barrier properties. Under an average pressure difference of 1.23 kPa, the Gurley air permeability of the breathable film should be between 0.1 μm / (Pa·s) and 10 μm / (Pa·s). If the Gurley air permeability is greater than 10 μm / (Pa·s), it means that the air permeability is too high, and the microbial barrier performance is usually too poor, and it cannot be used in the field of medical packaging. If the Gurley air permeability is less than 0.1 μm / (Pa·s), it means that the air permeability is too poor and cannot be used for ethylene oxide sterilization, and it cannot be widely used in the field of medical packaging. It can be seen that in the field of medical packaging, the development direction of breathable films is to increase microbial barrier properties at high air permeability while maintaining high strength.

[0003] The high-strength breathable membranes available on the market include DuPont's Tyvek, which has air permeability that meets the requirements of ethylene oxide sterilization, and has high strength and high microbial barrier properties. However, Tyvek is produced from polyethylene through a flash spinning process, which requires high temperature, high pressure and the participation of organic solvents in the production process. The production conditions are extremely harsh, and it is only suitable for the production of polyolefin breathable membranes. The use of non-polyolefin materials to prepare high-strength and high microbial barrier breathable films can make the raw materials for the preparation of breathable films more abundant. However, existing non-polyolefin materials, such as non-polyolefin non-woven fabrics, aramid paper, nylon filter cloth, etc., have a high air permeability that is much greater than 10μm / (Pa·s), but have poor microbial barrier properties or no microbial barrier properties at all. Therefore, how to provide a non-polyolefin breathable film with high microbial barrier properties is a technical problem that needs to be solved at present. Summary of the invention

[0004] Based on this, the purpose of the present invention is to overcome the deficiencies of the above-mentioned prior art and provide a non-polyolefin breathable film with high microbial barrier and high strength and a preparation method thereof. As mentioned above, the existing non-polyolefin materials, such as non-polyolefin non-woven fabrics, aramid paper, nylon filter cloth, etc., have high air permeability because their air permeability is much greater than 10 μm / (Pa·s), but their microbial barrier properties are poor or completely non-microbial barrier properties. Therefore, the present invention needs to overcome the problem that the air permeability of non-polyolefin materials cannot meet the requirements and also improve their microbial barrier properties. The inventors of the present invention have discovered through research that a polyamide breathable functional membrane can be constructed on the surface of a non-polyolefin membrane to obtain a non-polyolefin breathable film that meets the air permeability requirements. The inventors have also discovered in actual research that a hydrophobic surface treatment of the prepared breathable film can greatly increase the microbial barrier performance without changing the air permeability. Combined with this new discovery, the microbial barrier grade LRV of the non-polyolefin membrane can be increased to no less than 3, thereby overcoming the technical difficulty in the art that non-polyolefin materials have been difficult to achieve both high-level microbial barrier grades and air permeability. Moreover, the non-polyolefin membrane obtained by the present invention also has relatively high mechanical properties.

[0005] The first aspect of the present invention is to provide a non-polyolefin membrane, which contains a hydrophobic agent, a base membrane and polyamide at least partially located on both sides of the base membrane, and the Gurley air permeability of the non-polyolefin membrane is not more than 10μm / (Pa·s) and not less than 1.5μm / (Pa·s) under an average pressure difference of 1.23kPa; the microbial barrier grade LRV of the non-polyolefin membrane is not less than 3; wherein the material of the base membrane is non-polyolefin.

[0006] In a preferred embodiment of the present invention, the surface contact angle of the non-polyolefin film is not less than 90 degrees, preferably 90-180 degrees, and more preferably 120-180 degrees.

[0007] In a preferred embodiment of the present invention, under an average pressure difference of 1.23 kPa, the Gurley air permeability of the non-polyolefin membrane is not greater than 5 μm / (Pa·s) and not less than 1.5 μm / (Pa·s), more preferably not greater than 2 μm / (Pa·s) and not less than 1.5 μm / (Pa·s).

[0008] In a preferred embodiment of the present invention, the hydrophobic agent is selected from at least one of an organosilicon compound, a fluorocarbon compound, a fluorosilane, and a paraffin hydrophobic agent; preferably at least one of an organosilicon compound and a fluorocarbon compound, including but not limited to at least one of the fluorocarbon hydrophobic agent Clariant Nuva N2114, octyltriethoxysilane, and 1H,1H,2H,2H-perfluorodecyltrimethoxysilane.

[0009] General non-polyolefins are used as base films, such as non-polyolefin PET non-woven fabrics, aramid paper, nylon filter cloth, etc., because their air permeability is much greater than 10μm / (Pa·s), and they have high air permeability, but poor or no microbial barrier properties. In the prior art, it is difficult to prepare such materials into films with suitable air permeability and high microbial barrier properties. Even if the air permeability of such films is reduced by coating other polymers, direct coating of polymers can easily cause the film to lose its air permeability. Therefore, it is very difficult to use such non-polyolefins as base films to obtain films with suitable air permeability, high microbial barrier properties and high strength. The inventor of the present invention unexpectedly discovered through research that by using the above-mentioned non-polyolefin as a base film, coating a specific suitable concentration of polyamide casting solution on both sides of the base film, and then solidifying the polyamide on the base film in a solidification bath, a non-polyolefin film with suitable air permeability, good microbial barrier properties, and high strength can be obtained according to this method, which is suitable for the field of medical packaging, greatly broadens the source of breathable films used in the field of medical packaging, and has extremely high application value. In a preferred embodiment of the present invention, the non-polyolefin film includes a hydrophobic agent, a base film, and polyamide at least partially located on both sides of the base film.

[0010] In a preferred embodiment of the present invention, the polyamide is at least one of nylon 6, nylon 612, nylon 66, and nylon 1212.

[0011] In a preferred embodiment of the present invention, the non-polyolefin membrane is prepared by the following method: a polyamide solution is coated on both sides of the base membrane, and after the polyamide is solidified, it is contacted with a hydrophobic agent to obtain the non-polyolefin membrane. The Gurley air permeability of the obtained non-polyolefin membrane is not greater than 10 μm / (Pa·s) and not less than 1.5 μm / (Pa·s) at an average pressure difference of 1.23 kPa.

[0012] In a preferred embodiment of the present invention, the base membrane is a polymer membrane with strong polarity and high mechanical strength, including but not limited to a base membrane of at least one of PET non-woven fabric (PET is polyethylene terephthalate, also known as polyester resin), aramid paper, and nylon filter cloth.

[0013] For example, when the substrate is a PET non-woven fabric, the thickness of the obtained breathable film is not more than 250 microns, the Gurley air permeability is not more than 10 μm / (Pa·s) and not less than 1.5 μm / (Pa·s) (average pressure difference is 1.23 kPa), the microbial barrier rating LRV is not less than 3.0, the surface contact angle is not less than 90 degrees, and the tensile strength is not less than 20 MPa. The non-polyolefin breathable film has a structural feature that the substrate is a high-strength and high-permeability PET non-woven fabric, and the surface or fiber gaps of the substrate are filled with a porous film formed by polyamide. After the surface is hydrophobic treated, its microbial barrier performance is greatly improved.

[0014] The base film PET nonwoven fabric has excellent air permeability, the Gurley air permeability is much greater than 10μm / (Pa·s) (cannot be detected by instruments), the tensile strength is not less than 20MPa, and the filament PET nonwoven fabric is preferably a fiber with an average diameter between 15μm and 25μm.

[0015] As an example, when the base membrane is aramid paper, the thickness of the resulting breathable membrane is not more than 180 microns, the Gurley air permeability is not more than 10 μm / (Pa·s) and not less than 1.5 μm / (Pa·s) (the average pressure difference is 1.23 kPa), the microbial barrier grade LRV is not less than 3.0, the surface contact angle is not less than 90 degrees, and the tensile strength is not less than 25 MPa.

[0016] The non-polyolefin breathable film has the structural characteristics that the substrate is a high-strength and high-permeability aramid paper, the surface of the substrate or the fiber gaps are filled with a porous film formed by polyamide, and the surface of the film is hydrophobic.

[0017] The base film aramid paper has excellent air permeability, the Gurley air permeability is much greater than 10μm / (Pa·s) (cannot be detected by instruments), and the tensile strength is not less than 25MPa.

[0018] As an example, when the base membrane is a nylon filter cloth, the non-polyolefin breathable film provided by the present invention has a thickness of no more than 160 microns, a Gurley air permeability of no more than 10 μm / (Pa·s) and no less than 1.5 μm / (Pa·s) (average pressure difference is 1.23 kPa), a microbial barrier rating LRV of no less than 3.0, a surface contact angle of no less than 90 degrees, and a tensile strength of no less than 30 MPa. The nylon filter cloth is woven from nylon fibers, has excellent air permeability, and a Gurley air permeability far greater than 10 μm / (Pa·s) (cannot be detected by an instrument). The nylon filter cloth is preferably no less than 300 mesh, and more preferably no less than 400 mesh.

[0019] In a preferred embodiment of the present invention, the non-polyolefin film is obtained by the following preparation method: a polyamide solution is coated on both sides of the base film, and after the polyamide is solidified, it is contacted with a hydrophobic agent for hydrophobic treatment to obtain the non-polyolefin film; the Gurley air permeability of the obtained non-polyolefin film is not greater than 10 μm / (Pa·s) and not less than 1.5 μm / (Pa·s) under an average pressure difference of 1.23 kPa.

[0020] Preferably, the non-polyolefin film is obtained by the following preparation method:

[0021] (1) firstly coating a first solution containing polyamide on one side of the base film, and then coagulating the polyamide on the base film in a coagulation bath;

[0022] (2) coating the other side of the film obtained in step (1) with a second solution containing polyamide, and then coagulating the polyamide on the film in a coagulation bath to obtain the non-polyolefin film;

[0023] Wherein, the mass concentration of polyamide in the first solution is 3%-10%; the mass concentration of polyamide in the second solution is 5%-30%;

[0024] (3) The membrane obtained in step (2) is contacted with a hydrophobic agent for hydrophobic treatment.

[0025] The non-polyolefin film includes a hydrophobic agent, a base film and a polyamide at least partially located on both sides of the base film; wherein the non-polyolefin film, before the hydrophobic treatment, has a structural feature of a base film and a porous film formed on its surface or between fiber gaps, the porous film is a porous film formed by immersing the above-mentioned specific polyamide casting liquid in a polyamide poor solvent (also called a coagulation bath) to undergo phase separation, and the use of the polyamide casting liquid in the above-mentioned specific concentration range can obtain a film with suitable air permeability and high strength, and after the hydrophobic treatment, its microbial barrier performance is greatly improved.

[0026] The second aspect of the present invention is to provide a method for preparing the non-polyolefin film according to the first aspect, comprising:

[0027] The polyamide solution is coated on both sides of the base film, and after the polyamide solidifies, it is contacted with a hydrophobic agent for hydrophobic treatment to obtain the non-polyolefin film; the Gurley air permeability of the obtained non-polyolefin film is not greater than 10 μm / (Pa·s) and not less than 1.5 μm / (Pa·s) under an average pressure difference of 1.23 kPa.

[0028] In a preferred embodiment of the present invention, the preparation method comprises the following steps:

[0029] (1) firstly coating a first solution containing polyamide on one side of the base film, and then coagulating the polyamide on the base film in a coagulation bath;

[0030] (2) coating the other side of the membrane obtained in step (1) with a second solution containing polyamide, and then coagulating the polyamide on the membrane in a coagulation bath;

[0031] Wherein, the mass concentration of polyamide in the first solution is 3%-10%; the mass concentration of polyamide in the second solution is 5%-30%;

[0032] (3) The membrane obtained in step (2) is contacted with a hydrophobic agent for hydrophobic treatment.

[0033] In a preferred embodiment of the present invention, the mass concentration of polyamide in the first solution is 5%-10%, preferably 5%-8%.

[0034] In a preferred embodiment of the present invention, the mass concentration of polyamide in the second solution is 10%-30%.

[0035] In a more preferred embodiment of the present invention, the mass concentration of polyamide in the first solution is 5%-10%, preferably 5%-8%; the mass concentration of polyamide in the second solution is 10%-30%.

[0036] As mentioned above, preferably, the base film is at least one of PET non-woven fabric, aramid paper, and nylon filter cloth.

[0037] The concentration of the polyamide casting solution should be within a suitable range, so that the Gurley air permeability of the film is not greater than 10 μm / (Pa·s) and not less than 0.1 μm / (Pa·s) after being immersed in a coagulation bath and undergoing phase separation. In a preferred embodiment of the present invention, when the substrate film is a PET non-woven fabric, the mass concentration of the polyamide in the second solution is 10% to 30%, preferably 10% to 20%, and more preferably 15% to 20%; and / or, the mass concentration of the polyamide in the first solution is 5%-10%, preferably 5%-8%.

[0038] When the substrate film is aramid paper, the mass concentration of polyamide in the second solution is 15% to 30%, preferably 15% to 20%, and / or the mass concentration of polyamide in the first solution is 5%-10%, preferably 5%-8%.

[0039] When the substrate membrane is nylon filter cloth, the mass concentration of polyamide in the second solution is 10%-20%, preferably 15%-20%, and / or the mass concentration of polyamide in the first solution is 5%-10%, preferably 5%-8%.

[0040] In a preferred embodiment of the present invention, the hydrophobic agent is selected from at least one of an organosilicon compound, a fluorocarbon compound, a fluorosilane, and a paraffin hydrophobic agent, preferably at least one of an organosilicon compound and a fluorocarbon compound, including but not limited to at least one of the fluorocarbon hydrophobic agent Clariant Nuva N2114, octyltriethoxysilane, and 1H,1H,2H,2H-perfluorodecyltrimethoxysilane.

[0041] In a preferred embodiment of the present invention, the coagulation baths in step (1) and step (2) are the same or different, and each is at least one of water, ethanol, methanol, and acetone.

[0042] In a preferred embodiment of the present invention, the first solution and the second solution are respectively solutions formed by dissolving polyamide in formic acid, methanol / CaCl2, and ethanol / CaCl2.

[0043] The polyamide casting solution is a solution of polyamide in its good solvent, and the polyamide good solvent is preferably formic acid, methanol / CaCl2 or ethanol / CaCl2 with a mass ratio of 4:1. The polyamide coagulation bath is a solvent that cannot dissolve polyamide alone and is miscible with the above-mentioned good solvent, preferably water, a mixed solvent of water / ethanol, water / methanol, or water / acetone in any proportion.

[0044] When the base membrane is a nylon filter cloth, not all polyamide solutions can be used as casting solutions to obtain non-polyolefin films with excellent performance. For example, when the casting solution is a solution formed by polyamide dissolved in formic acid, coating it on the surface of the nylon filter cloth will cause part of the nylon filter cloth to dissolve or be etched, resulting in higher air permeability and lower microbial barrier rating. After research, the inventors of the present invention found that in a preferred embodiment of the present invention, when the base membrane is a nylon filter cloth, the first solution and the second solution are each a solution formed by polyamide dissolved in methanol / CaCl2 or ethanol / CaCl2.

[0045] In a preferred embodiment of the present invention, the hydrophobic treatment method comprises: immersing the membrane obtained in step (2) in a solution containing a hydrophobic agent, and then drying to obtain the non-polyolefin membrane, and / or placing the membrane obtained in step (2) in vapor containing a hydrophobic agent for vapor deposition to obtain the non-polyolefin membrane.

[0046] In a preferred embodiment of the present invention, the soaking conditions include:

[0047] The mass concentration of the solution containing the hydrophobic agent is 0.1%-20%, preferably 0.1%-10%, preferably 1%-10%, and / or the immersion time is 5 minutes to 60 minutes, more preferably 20 minutes to 60 minutes, and / or the immersion temperature is between the freezing point and boiling point of the hydrophobic agent solution.

[0048] In a preferred embodiment of the present invention, the vapor deposition conditions are: the pressure is between vacuum and normal pressure, preferably 10 -2 Pa to normal pressure, and / or the vapor deposition time is between 1 hour and 24 hours, more preferably between 2 hours and 8 hours.

[0049] Before the hydrophobic treatment, necessary pretreatment, such as plasma treatment, may be performed to generate more active groups on the membrane surface. The plasma treatment time is between 10 seconds and 60 minutes, more preferably 1 minute to 10 minutes.

[0050] In a preferred embodiment of the present invention, the coating method is scraping. Preferably, the distance between the lower edge of the scraping device and the base film does not exceed 50 μm, more preferably does not exceed 40 μm, and more preferably does not exceed 30 μm.

[0051] In a preferred embodiment of the present invention, after the polyamide is coagulated on the membrane in the coagulation bath, the method further comprises a step of drying the obtained membrane.

[0052] As an example, in a more preferred embodiment of the present invention, the preparation method of the above-mentioned high-strength non-polyolefin breathable film is described in detail as follows:

[0053] Step 1: uniformly coating a polyamide casting solution (ie, the first solution) having good compatibility with the PET substrate film on one side of the PET substrate film having high strength and high air permeability.

[0054] The high-strength and high-permeability PET base film has excellent air permeability, the Gurley air permeability is much greater than 10μm / (Pa·s) (cannot be detected by instruments), the tensile strength is not less than 20MPa, and the puncture strength is not less than 15N. The filament PET non-woven fabric is preferably a fiber with an average fiber diameter between 15μm and 25μm.

[0055] The polyamide casting solution is a solution in which polyamide is dissolved in its good solvent, and the polyamide is at least one of nylon 6, nylon 612, nylon 66, and nylon 1212. The polyamide good solvent is preferably formic acid, methanol / CaCl2 or ethanol / CaCl2 with a mass ratio of 4:1. The concentration of the casting solution should be within a suitable range, so that the Gurley air permeability of the film is not greater than 30 μm / (Pa·s) and not less than 10 μm / (Pa·s) after being immersed in a coagulation bath for phase separation. For the PET substrate film, the mass concentration of the polyamide in the first solution is preferably 3% to 10%, more preferably 5% to 10%, and more preferably 5% to 8%.

[0056] The coating process is preferably carried out by scraping, and the distance between the film applicator or scraper and the substrate is preferably not more than 40 μm, more preferably not more than 30 μm.

[0057] Step 2: Immerse the coated basement membrane in a coagulation bath. After a period of time, take out the basement membrane, wash and dry it.

[0058] The coagulation bath is a poor solvent for polyamide and is miscible with a good solvent for polyamide. The polyamide coagulation bath is preferably water, a mixed solvent of water / ethanol, water / methanol, or water / acetone in any proportion.

[0059] The time for which the coated substrate film is immersed in the coagulation bath is not strictly limited, but is preferably not more than 10 minutes, more preferably not more than 5 minutes.

[0060] Step 3: The uncoated side of the dried membrane is then evenly coated with a polyamide casting solution (ie, the second solution) having good compatibility with the membrane.

[0061] The polyamide casting solution is the same as that in step 2, and the concentration of the casting solution should be within a suitable range, so that the Gurley air permeability of the final film is not greater than 10 μm / (Pa·s) and not less than 0.1 μm / (Pa·s) after being immersed in a coagulation bath and undergoing phase separation. For a PET substrate film, the mass concentration of the polyamide in the second solution is preferably 10% to 30%, more preferably 10% to 20%, and more preferably 15% to 20%.

[0062] Step 4: Immerse the membrane in the coagulation bath again. After a period of time, take out the membrane, wash and dry it;

[0063] Step 5: The obtained film is subjected to a hydrophobic treatment to change the film from hydrophilic to hydrophobic.

[0064] The third aspect of the present invention is to provide an application of the non-polyolefin film described in the first aspect or the non-polyolefin film obtained by the preparation method described in the second aspect in the field of medical materials.

[0065] The non-polyolefin breathable film of the present invention not only has suitable air permeability, but also has extremely high microbial barrier properties, is very suitable for the field of medical packaging, and has extremely high promotion and application value.

[0066] The present invention adopts non-polyolefin as the base membrane, coats a specific suitable concentration of polyamide casting liquid on both sides of the base membrane, and then coagulates the polyamide on the base membrane in a coagulation bath to obtain a film with suitable air permeability, and then undergoes hydrophobic treatment to obtain a non-polyolefin membrane with suitable air permeability and excellent microbial barrier properties.

[0067] It can be seen from the above technical scheme that the present invention overcomes the technical difficulty that the conventional non-polyolefin membrane cannot have both suitable air permeability and good microbial barrier performance, and not only obtains a non-polyolefin membrane with suitable air permeability: under an average pressure difference of 1.23 kPa, the Gurley air permeability of the non-polyolefin membrane is not more than 10 μm / (Pa·s) and not less than 1.5 μm / (Pa·s), but, more surprisingly, the non-polyolefin membrane of the present invention has extremely high microbial barrier performance, and the microbial barrier grade LRV of the non-polyolefin membrane is not less than 3, which has extremely high application value. DETAILED DESCRIPTION

[0068] The present invention is described in detail below in conjunction with specific embodiments. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by those skilled in the art based on the contents of the present invention still fall within the scope of protection of the present invention.

[0069] The Gurley air permeability is measured in accordance with the provisions of GB / T 458-2008, the microbial barrier grading test is tested in accordance with the provisions of YY / T0681.10-2011, and the tensile strength is measured in accordance with the provisions of GB / T 1040.3-2006.

[0070] PET filament spunbond nonwoven fabric was purchased from Shanghai Tianlue Textile New Materials Co., Ltd., with a thickness of 190 μm. Aramid paper was purchased from Yantai Minshida Special Paper Co., Ltd., with a thickness of 130 μm. The nylon filter cloth used was a 300-mesh filter cloth.

[0071] The plasma generator is a small plasma cleaner NE-PE10 produced by Shenzhen Nan Technology Co., Ltd. The power is set to 100 W and the gas is air.

[0072] The fluorocarbon hydrophobic agent is commercially available Clariant Nuva N2114, with a concentration of 2 wt %. Other raw materials, unless otherwise specified, are conventional commercial products.

[0073] In the present invention, in the following examples and comparative examples, all coating methods are scraping, and the distance between the film applicator and the substrate is 30 μm.

[0074] Example 1

[0075] A commercially available PET filament spunbond nonwoven fabric was coated with a nylon 6 formic acid solution at a concentration of 5wt% on one side, then immersed in water for coagulation, taken out and naturally dried, and a nylon 6 formic acid solution at a concentration of 15wt% was coated on the other side of the obtained film, immersed in water again for coagulation, taken out and naturally dried. The obtained film was soaked in a fluorocarbon hydrophobic agent Clariant Nuva N2114 at a concentration of 2wt% for 10 minutes, taken out and placed in a 150°C oven for 1 hour to obtain the final film. The Gurley air permeability, contact angle, microbial barrier grade and tensile strength of the film were tested.

[0076] Example 2

[0077] A commercially available PET filament spunbond nonwoven fabric was coated with a 5wt% formic acid solution of nylon 6 on one side, then immersed in water for coagulation, taken out and naturally dried, and the other side of the obtained film was coated with a 15wt% formic acid solution of nylon 6, immersed in water again for coagulation, taken out and naturally dried. The obtained film was placed in a plasma for 1 minute, then immersed in a 1wt% aqueous solution of octyltriethoxysilane for 1 hour, taken out and placed in a 60°C oven for 2 hours to obtain the final film. The Gurley air permeability, contact angle, microbial barrier grade and tensile strength of the film were tested.

[0078] Example 3

[0079] The commercially available PET filament spunbond nonwoven fabric was coated with a nylon 6 formic acid solution at a concentration of 5wt% on one side, then immersed in water for coagulation, taken out and naturally dried, and the other side of the obtained film was coated with a nylon 6 formic acid solution at a concentration of 15wt%, immersed in water again for coagulation, taken out and naturally dried. The obtained film was treated in plasma for 1 minute, and then placed in an atmosphere of 1H,1H,2H,2H-perfluorodecyltrimethoxysilane for chemical deposition for 2 hours. The atmosphere was generated by heating 1H,1H,2H,2H-perfluorodecyltrimethoxysilane liquid at 70°C in a sealed container. The final film was tested for Gurley air permeability, contact angle, microbial barrier grade and tensile strength.

[0080] Example 4

[0081] A commercially available aramid paper was coated with a 5wt% formic acid solution of nylon 6 on one side, then immersed in water for coagulation, taken out and naturally dried, and the other side of the obtained film was coated with a 15wt% formic acid solution of nylon 6, immersed in water again for coagulation, taken out and naturally dried. The obtained film was soaked in a 2wt% fluorocarbon hydrophobic agent Clariant NuvaN2114 for 10 minutes, taken out and placed in a 150°C oven for 1 hour to obtain the final film. The Gurley air permeability, contact angle, microbial barrier grade and tensile strength of the film were tested.

[0082] Example 5

[0083] A commercially available 300-mesh nylon filter cloth was coated with a nylon 6 methanol / CaCl2 solution (methanol to CaCl2 mass ratio of 4:1) on one side at a concentration of 5wt%, then immersed in water for coagulation, taken out and naturally dried, and the other side of the obtained film was coated with a nylon 6 methanol / CaCl2 solution (methanol to CaCl2 mass ratio of 4:1) at a concentration of 15wt%, immersed in water again for coagulation, taken out and naturally dried. The obtained film was soaked in a fluorocarbon hydrophobic agent Clariant Nuva N2114 at a concentration of 2wt% for 10 minutes, taken out and placed in a 150°C oven for 1 hour to obtain the final film. The Gurley air permeability, contact angle, microbial barrier grade and tensile strength of the film were tested.

[0084] Example 6

[0085] A commercially available PET filament spunbond nonwoven fabric was coated with a nylon 6 formic acid solution at a concentration of 5wt% on one side, then immersed in water for coagulation, taken out and naturally dried, and a nylon 6 formic acid solution at a concentration of 10wt% was coated on the other side of the obtained film, immersed in water again for coagulation, taken out and naturally dried. The obtained film was soaked in a fluorocarbon hydrophobic agent Clariant Nuva N2114 at a concentration of 2wt% for 10 minutes, taken out and placed in a 150°C oven for 1 hour to obtain the final film. The Gurley air permeability, contact angle, microbial barrier grade and tensile strength of the film were tested.

[0086] Example 7

[0087] A commercially available PET filament spunbond nonwoven fabric was coated with a 5wt% formic acid solution of nylon 6 on one side, then immersed in water for coagulation, taken out and naturally dried, and the other side of the obtained film was coated with a 30wt% formic acid solution of nylon 6, immersed in water again for coagulation, taken out and naturally dried. The obtained film was soaked in a 2wt% fluorocarbon hydrophobic agent Clariant Nuva N2114 for 10 minutes, taken out and placed in a 150°C oven for 1 hour to obtain the final film. The Gurley air permeability, contact angle, microbial barrier grade and tensile strength of the film were tested.

[0088] Comparative Example 1

[0089] A commercially available PET filament spunbond nonwoven fabric was coated with a nylon 6 formic acid solution at a concentration of 5wt% on one side, then immersed in water for coagulation, taken out and naturally dried, and a nylon 6 formic acid solution at a concentration of 15wt% was coated on the other side of the obtained film, immersed in water again for coagulation, taken out and naturally dried. The Gurley air permeability, contact angle, microbial barrier grade and tensile strength of the film were tested.

[0090] Comparative Example 2

[0091] A commercially available aramid paper was coated with a 5wt% formic acid solution of nylon 6 on one side, then immersed in water for coagulation, taken out and naturally dried, and the other side of the obtained film was coated with a 15wt% formic acid solution of nylon 6, immersed in water again for coagulation, taken out and naturally dried. The Gurley air permeability, contact angle, microbial barrier grade and tensile strength of the film were tested.

[0092] Comparative Example 3

[0093] A commercially available 300-mesh nylon filter cloth was coated with a nylon 6 methanol / CaCl2 solution (methanol to CaCl2 mass ratio of 4:1) at a concentration of 5wt% on one side, then immersed in water for coagulation, taken out and naturally dried, and the other side of the obtained film was coated with a nylon 6 methanol / CaCl2 solution (methanol to CaCl2 mass ratio of 4:1) at a concentration of 15wt%, immersed in water again for coagulation, taken out and naturally dried. The film was tested for Gurley air permeability, contact angle, microbial barrier grade and tensile strength.

[0094] Comparative Example 4

[0095] A commercially available PET filament spunbond nonwoven fabric was coated with a nylon 6 formic acid solution at a concentration of 10 wt %, then immersed in water for coagulation, and naturally dried after being taken out to obtain the final film. The Gurley air permeability, contact angle, microbial barrier grade and tensile strength of the film were tested.

[0096] Comparative Example 5

[0097] A commercially available PET filament spunbond nonwoven fabric was coated with a nylon 6 formic acid solution at a concentration of 25 wt%, then immersed in water for coagulation, and naturally dried after being taken out to obtain the final film. The Gurley air permeability, contact angle, microbial barrier grade and tensile strength of the film were tested.

[0098] Comparative Example 6

[0099] A commercially available PET filament spunbond nonwoven fabric was coated with a 15wt% nylon 6 formic acid solution on one side, then immersed in water for coagulation, taken out and naturally dried, and the other side of the obtained film was coated with a 15wt% nylon 6 formic acid solution, then immersed in water for coagulation, taken out and naturally dried to obtain the final film. The Gurley air permeability, contact angle, microbial barrier grade and tensile strength of the film were tested.

[0100] Table 1

[0101]

[0102] As is known to all, conventional PET nonwoven fabrics, aramid paper, and nylon filter fabrics have too high air permeability and poor or no microbial barrier properties. As shown in Comparative Examples 4-5, even if the air permeability of such films is reduced by coating with other polymers, the microbial barrier properties of the films are still very poor. Therefore, it is very difficult to obtain a breathable film with suitable air permeability and high microbial barrier properties by a simple coating method.

[0103] It can be seen from the embodiments of the present invention that a polyamide casting liquid with a specific suitable concentration is coated on both sides of the base membrane, and then the polyamide is coagulated on the base membrane in a coagulation bath, and then combined with a hydrophobic treatment. The non-polyolefin membrane obtained according to this method not only has suitable air permeability but also has high strength. What is more unexpected is that compared with all comparative examples, the non-polyolefin membrane significantly improves the microbial barrier property and achieves unexpected technical effects.

[0104] It should be noted that the embodiments described above are only used to explain the present invention and do not constitute any limitation to the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present invention may be modified as specified within the scope of the claims of the present invention, and the present invention may be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein, on the contrary, the present invention can be extended to all other methods and applications with the same functions.

[0105] All publications, patent applications, patents and other references mentioned in this specification are incorporated herein by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings conventionally understood by those skilled in the art. In the event of a conflict, the definition in this specification shall prevail.

[0106] When this specification uses the prefix "well-known to those skilled in the art", "prior art" or similar terms to introduce materials, substances, methods, steps, devices or components, etc., the objects introduced by the prefix cover those commonly used in the art when this application is filed, but also include those that are not commonly used at present but will become recognized in the art as being suitable for similar purposes.

[0107] The endpoints and any values ​​of the scope disclosed in the present application document are not limited to the precise scope or value, and these scopes or values ​​should be understood to include values ​​close to these scopes or values. For numerical ranges, between the endpoint values ​​of each scope, between the endpoint values ​​of each scope and a separate point value, and between separate point values, one or more new numerical ranges can be combined with each other, and these numerical ranges should be considered as specifically disclosed in this article. Hereinafter, in principle, each technical solution can be combined with each other to obtain a new technical solution, which should also be considered as specifically disclosed in this article.

[0108] In the context of the present specification, any matters or items not mentioned are directly applicable to those known in the art without any changes except those explicitly stated.

[0109] Moreover, any embodiment described in this document may be freely combined with one or more other embodiments described in this document, and the technical solutions or technical ideas formed thereby are deemed to be part of the original disclosure or original record of the present invention, and should not be regarded as new content that has not been disclosed or anticipated in this document, unless a person skilled in the art considers that the combination is obviously unreasonable.

Claims

1. A non-polyolefin membrane, comprising a hydrophobic agent, a substrate membrane and polyamide at least partially located on both sides of the substrate membrane, wherein the Gurley air permeability of the non-polyolefin membrane is not greater than 10 μm / (Pa·s) and not less than 1.5 μm / (Pa·s) under an average pressure difference of 1.23 kPa; and the microbial barrier grade LRV of the non-polyolefin membrane is not less than 3; in, The material of the base film is non-polyolefin.

2. The non-polyolefin film according to claim 1, characterized in that: The surface contact angle of the non-polyolefin film is not less than 90 degrees, preferably 120-180 degrees; and / or, At an average pressure difference of 1.23 kPa, the Gurley air permeability of the non-polyolefin membrane is not greater than 5 μm / (Pa·s) and not less than 1.5 μm / (Pa·s); and / or, The base film is at least one of PET non-woven fabric, aramid paper, and nylon filter cloth; and / or, The hydrophobic agent is selected from at least one of an organosilicon compound, a fluorocarbon compound, a fluorosilane, and a paraffin hydrophobic agent; preferably at least one of an organosilicon compound and a fluorocarbon compound.

3. The non-polyolefin film according to claim 1 or 2, characterized in that: The polyamide is at least one of nylon 6, nylon 612, nylon 66, and nylon 1212; and / or The non-polyolefin film is prepared by the following method: A polyamide solution is coated on both sides of the base film. After the polyamide solidifies, it is contacted with a hydrophobic agent to obtain the non-polyolefin film. The Gurley air permeability of the obtained non-polyolefin film is not greater than 10 μm / (Pa·s) and not less than 1.5 μm / (Pa·s) at an average pressure difference of 1.23 kPa.

4. A method for preparing a non-polyolefin film according to any one of claims 1 to 3, comprising: Coating a polyamide solution on both sides of the base film, and after the polyamide solidifies, contacting with a hydrophobic agent for hydrophobic treatment to obtain the non-polyolefin film; The Gurley air permeability of the obtained non-polyolefin film is not more than 10 μm / (Pa·s) and not less than 1.5 μm / (Pa·s) at an average pressure difference of 1.23 kPa.

5. The preparation method according to claim 4, characterized in that The following steps are involved: (1) firstly coating a first solution containing polyamide on one side of the base film, and then coagulating the polyamide on the base film in a coagulation bath; (2) coating the other side of the membrane obtained in step (1) with a second solution containing polyamide, and then coagulating the polyamide on the membrane in a coagulation bath; Wherein, the mass concentration of polyamide in the first solution is 3%-10%; The mass concentration of polyamide in the second solution is 5%-30%; (3) The membrane obtained in step (2) is contacted with a hydrophobic agent for hydrophobic treatment.

6. The preparation method according to claim 5, characterized in that: The mass concentration of polyamide in the first solution is 5%-10%, preferably 5%-8%; and / or, The mass concentration of polyamide in the second solution is 10%-30%.

7. The preparation method according to claim 5, characterized in that: The base film is at least one of PET non-woven fabric, aramid paper, and nylon filter cloth; and / or, The hydrophobic agent is selected from at least one of an organosilicon compound, a fluorocarbon compound, a fluorosilane, and a paraffin hydrophobic agent, preferably at least one of an organosilicon compound and a fluorocarbon compound; and / or, The coagulation baths in step (1) and step (2) are the same or different, and each is at least one of water, ethanol, methanol, and acetone; and / or, The first solution and the second solution are each a solution of polyamide dissolved in formic acid, methanol / CaCl2, or ethanol / CaCl2; preferably, When the base membrane is a nylon filter cloth, the first solution and the second solution are respectively solutions formed by dissolving polyamide in one of methanol / CaCl 2 and ethanol / CaCl 2 .

8. The preparation method according to any one of claims 5 to 7, characterized in that: The hydrophobic treatment method comprises: immersing the membrane obtained in step (2) in a solution containing a hydrophobic agent, and then drying to obtain the non-polyolefin membrane, and / or placing the membrane obtained in step (2) in vapor containing a hydrophobic agent for vapor deposition to obtain the non-polyolefin membrane.

9. The preparation method according to claim 8, characterized in that: The soaking conditions include: The mass concentration of the solution containing the hydrophobic agent is 0.1%-20%, preferably 0.1%-10%, preferably 1%-10%, and / or the soaking time is 5 minutes to 60 minutes, more preferably 20 minutes to 60 minutes, and / or the soaking temperature is between the freezing point and the boiling point of the hydrophobic agent solution; and / or, The vapor deposition conditions are: The pressure is between vacuum and normal pressure, preferably 10 -2 Pa to normal pressure, and / or the vapor deposition time is between 1 hour and 24 hours, more preferably between 2 hours and 8 hours.

10. The preparation method according to any one of claims 5 to 7, characterized in that: The coating method is scraping, preferably, the distance between the lower edge of the scraping device and the base film is no more than 50 μm, more preferably no more than 40 μm, more preferably no more than 30 μm; and / or, After the polyamide is coagulated on the film in the coagulation bath, the method further comprises a step of drying the obtained film.

11. Use of the non-polyolefin film according to any one of claims 1 to 3 or the non-polyolefin film obtained by the preparation method according to any one of claims 4 to 10 in the field of medical materials.

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