A flash-evaporated nonwoven fabric, its preparation method and application

Abstract

This application relates to a flash-evaporated nonwoven fabric, its preparation method, and its application, belonging to the field of polymer materials technology. The flash-evaporated nonwoven fabric provided in this application comprises the following components in parts by weight: 60-90 parts of polymethylpentene, 4-15 parts of polylactic acid, 4-10 parts of epoxy resin, 1-5 parts of styrene-ethylene-butene-styrene block copolymer, and 2-10 parts of modified calcium carbonate; wherein the modified calcium carbonate has a surface hydroxyl content greater than or equal to 10 hydroxyl groups / nm. 2 And less than or equal to 50 per nm 2 The flash-evaporated nonwoven fabric provided in this application possesses excellent mechanical properties, air permeability, and ethylene oxide desorption properties, and exhibits high reusability when used in the preparation of medical device packaging products. Furthermore, the raw materials for the flash-evaporated nonwoven fabric provided in this application are widely available, which is beneficial for practical production.

Description

Technical Field

[0001] This application relates to the field of polymer materials technology, and in particular to a flash-evaporated nonwoven fabric, its preparation method, and its application. Background Technology

[0002] Flash-evaporated nonwoven fabric is a new type of high-molecular breathable and waterproof material that can effectively block water from passing through while allowing gas to pass through. The main reason for this is that the surface of flash-evaporated nonwoven fabric can form evenly distributed micropores, thereby achieving excellent breathability.

[0003] Currently, pores are mainly created by introducing calcium carbonate. However, although the introduction of calcium carbonate can form a microporous structure to a certain extent, the post-processing is relatively complicated. It requires further acid washing to remove the microporous structure. Furthermore, due to the poor compatibility between calcium carbonate and the polymer resin matrix, the mechanical strength and waterproof performance of the resulting flash-evaporated nonwoven fabric will decrease to some extent.

[0004] In addition, the existing flash nonwoven fabrics are mostly used in the field of medical protection. In order to improve the rational and effective use of resources, reuse is generally considered. However, due to the special nature of the medical protection field, disinfection gas is generally used for treatment before reuse. Therefore, the residual amount after disinfection gas treatment is also a key indicator for evaluating whether it can be reused. Summary of the Invention

[0005] The purpose of this application is to overcome the shortcomings of the prior art and provide a flash nonwoven fabric with high air permeability, high mechanical strength, excellent waterproof performance, high ethylene oxide desorption efficiency, and high reusability when used in the field of medical packaging, as well as its preparation method and application.

[0006] To achieve the above objectives, in a first aspect of this application, a flash-evaporated nonwoven fabric is provided, comprising the following components in parts by weight: 60-90 parts of polymethylpentene, 4-15 parts of polylactic acid, 4-10 parts of epoxy resin, 1-5 parts of styrene-ethylene-butene-styrene block copolymer, and 2-10 parts of modified calcium carbonate.

[0007] The surface hydroxyl content of modified calcium carbonate is greater than or equal to 10 hydroxyl groups / nm. 2 And less than or equal to 50 per nm 2 .

[0008] The flash-evaporated nonwoven fabric provided in this application, by selecting appropriate mass fractions of components and combining them with each other, results in a flash-evaporated nonwoven fabric with excellent air permeability and waterproof performance. Furthermore, the obtained flash-evaporated nonwoven fabric has high mechanical strength and high reusability when subsequently applied in the field of medical packaging.

[0009] Specifically, this application selects polymethylpentene as the matrix resin, combined with the introduction of polylactic acid and epoxy resin. Polylactic acid, also known as polylactide, is a polyester polymer obtained from lactic acid as the main raw material. The introduction of polylactic acid can, to a certain extent, disrupt the regular structure of polymethylpentene, thereby effectively improving the rheological properties of the melt, enhancing the overall component compatibility, and refining the fiber diameter of the formed flash nonwoven fabric, resulting in a more compact fiber arrangement and thus effectively improving the mechanical properties of the flash nonwoven fabric. The addition of epoxy resin can further enhance the mechanical properties of the flash nonwoven fabric by working in conjunction with polylactic acid. The epoxy groups and benzene ring groups in the epoxy resin can bond with the carbonyl and hydroxyl groups in polylactic acid, and can also interact with the unsaturated bonds in polymethylpentene, forming a strong binding force between the components, thereby improving the excellent mechanical properties of the flash nonwoven fabric. Furthermore, due to the bonding of the components, the affinity of the hydrophilic groups for water can be reduced, thus achieving good waterproof performance. The introduction of styrene-ethylene-butene-styrene block copolymer (SEBS) further enhances the compatibility between components. The dispersed phase formed in the polymethylpentene, polylactic acid, and epoxy resin system added in this application exhibits a moderate phase state, thereby improving the overall performance of the prepared flash-evaporated nonwoven fabric. The introduction of modified calcium carbonate with a specific surface hydroxyl content allows for good dispersibility in the resin matrix. This excellent dispersibility not only makes the components more uniform but also prevents the modified calcium carbonate itself from agglomerating, thus forming a large number of microporous structures. Furthermore, unlike directly introducing calcium carbonate which requires acid washing, the modified calcium carbonate introduced in this application is surface-modified with starch, avoiding the weakening of the product's mechanical and waterproof properties caused by conventional calcium carbonate, thereby resulting in a flash-evaporated nonwoven fabric with excellent overall performance.

[0010] It should be noted that the surface hydroxyl content of modified calcium carbonate is determined by the Green's reagent method.

[0011] For example, the surface hydroxyl content of modified calcium carbonate can be 10 hydroxyl groups / nm. 2 12 per nm 2 14 per nm 2 16 per nm 2 18 per nm 2 20 units / nm 2 22 per nm 2 24 per nm 2 26 per nm 2 28 per nm 2 30 units / nm 2 32 per nm 2 34 units / nm 2 36 per nm 238 per nm 2 40 units / nm 2 42 units / nm 2 44 units / nm 2 46 units / nm 2 48 per nm 2 50 units / nm 2 The range of one or any two of them.

[0012] As a preferred embodiment of the flash-evaporated nonwoven fabric of this application, the flash-evaporated nonwoven fabric comprises the following components in parts by weight: 70-80 parts of polyamide resin, 6-10 parts of polylactic acid, 6-8 parts of epoxy resin, 3-4 parts of styrene-ethylene-butene-styrene block copolymer, and 6-8 parts of modified calcium carbonate.

[0013] This study found that the mass fraction of the components in flash-evaporated nonwoven fabric has a significant impact on the overall performance of the product. When the mass fraction of the components in the flash-evaporated nonwoven fabric is further selected within the above-mentioned range, the overall performance of the obtained flash-evaporated nonwoven fabric is even better.

[0014] As a preferred embodiment of the flash-evaporated nonwoven fabric of this application, the modified calcium carbonate has a surface hydroxyl content of greater than or equal to 20 hydroxyl groups / nm. 2 And less than or equal to 30 per nm 2 .

[0015] This study found that the surface hydroxyl content of modified calcium carbonate affects the air permeability and ethylene oxide desorption efficiency of flash-evaporated nonwoven fabrics. Further optimization involves selecting modified calcium carbonate with a surface hydroxyl content greater than or equal to 20 hydroxyl groups / nm. 2 And less than or equal to 30 per nm 2 When the flash-evaporated nonwoven fabric is used, the overall performance of the resulting fabric is even better.

[0016] As a preferred embodiment of the flash-evaporated nonwoven fabric of this application, the preparation method of modified calcium carbonate includes the following steps: carbon dioxide is introduced into calcium hydroxide slurry and starch is added and stirred. Then, carbon dioxide is continued to be introduced to react until the system is acidic. Then, an esterification modifier and a catalyst are added to carry out an in-situ esterification reaction. After the reaction is completed, the mixture is filtered, dried and pulverized to obtain modified calcium carbonate.

[0017] Preferably, the starch is added and stirred for 20 to 60 minutes.

[0018] Preferably, the esterification modifier includes at least one of hexanoic acid, decanoic acid, and octanoic acid.

[0019] Preferably, the catalyst comprises transglutaminase and pyridine; the mass ratio of transglutaminase to pyridine is 1:(10-20).

[0020] Preferably, the in-situ catalyst reaction is carried out at a temperature of 45–70°C for 1–6 hours.

[0021] Preferably, the mass ratio of starch, esterification modifier and catalyst is 1:(0.08-0.12):(0.01-0.1).

[0022] Preferably, the mass ratio of calcium hydroxide to starch is 1:(0.1-0.2).

[0023] This application research found that the modified calcium carbonate prepared by the method provided in this application can be modified by adding starch and introducing an esterification modifier to graft hydroxyl groups on the surface of starch or calcium carbonate. This effectively obtains modified calcium carbonate with a surface hydroxyl content within the range given in this application. On the one hand, starch is chosen for modification because it is also a polymer and has certain compatibility with other resin matrices. On the other hand, further treatment with the esterification modifier can reduce the hydroxyl content on the surface of calcium carbonate and starch, further improving the compatibility of modified calcium carbonate with the resin matrix of this application, increasing the dispersibility of the system, and forming a richer and more uniform microporous effect in subsequent preparation processes. This ensures the air permeability of the flash nonwoven fabric and the desorption efficiency of ethylene oxide, thereby improving the overall performance of the product.

[0024] As a preferred embodiment of the flash-evaporated nonwoven fabric of this application, the polylactic acid has a melting point greater than or equal to 165°C and less than or equal to 175°C.

[0025] As a preferred embodiment of the flash-evaporated nonwoven fabric of this application, the melt index of polylactic acid is greater than or equal to 9 g / 10 min and less than or equal to 18 g / 10 min.

[0026] It should be noted that the melt index of polylactic acid is tested according to ASTM D1238, and the test conditions are 190℃ and 5kg.

[0027] For example, the melting point of polylactic acid (PLA) can be any one or any two of the values ​​between 165°C, 168°C, 170°C, 172°C, and 175°C. The melt index of PLA can be any one or any two of the values ​​between 9 g / 10 min, 10 g / 10 min, 12 g / 10 min, 14 g / 10 min, 16 g / 10 min, and 18 g / 10 min.

[0028] This study found that when polylactic acid with a melting point and melt index within the range given in this application is further selected, it exhibits superior processing and mechanical properties, as well as better compatibility with other components, thereby effectively improving the overall performance of flash nonwoven fabric.

[0029] As a preferred embodiment of the flash-evaporated nonwoven fabric of this application, the epoxy equivalent of the epoxy resin is greater than or equal to 180 g / eq and less than or equal to 190 g / eq.

[0030] It should be noted that the epoxy equivalent of epoxy resin is tested using the acid value method.

[0031] For example, the epoxy equivalent of the epoxy resin can be any one or any two of the following values: 180 g / eq, 181 g / eq, 182 g / eq, 183 g / eq, 184 g / eq, 185 g / eq, 186 g / eq, 187 g / eq, 188 g / eq, 189 g / eq, and 190 g / eq.

[0032] This study found that the epoxy equivalent of the epoxy resin affects the bonding ability between the epoxy resin and polymethylpentene and polylactic acid, thereby affecting the overall performance of the product. When the epoxy equivalent of the epoxy resin is further selected within the range given in this application, the mechanical properties, air permeability and ethylene oxide resolution of the obtained flash nonwoven fabric are all superior.

[0033] As a preferred embodiment of the flash-evaporated nonwoven fabric of this application, the viscosity of a 10% by mass toluene solution of the styrene-ethylene-butene-styrene block copolymer is greater than or equal to 480 cp and less than or equal to 600 cp.

[0034] It should be noted that the test method for the viscosity of a 10% by mass toluene solution of styrene-ethylene-butene-styrene block copolymer is to refer to ASTM D2196.

[0035] For example, the viscosity of a 10% by mass toluene solution of styrene-ethylene-butene-styrene block copolymer can be any one or any two of the following values: 480 cp, 500 cp, 520 cp, 540 cp, 560 cp, 580 cp, and 600 cp.

[0036] This application research found that styrene-ethylene-butene-styrene block copolymer can effectively enhance the compatibility between polymethylpentene, polylactic acid and epoxy resin, and can also effectively improve the dispersibility of modified calcium carbonate in the system, enhance the microporous effect of subsequent properties. In particular, when the viscosity of the 10% by mass toluene solution of styrene-ethylene-butene-styrene block copolymer is further selected within the range given in this application, the overall performance of the obtained flash nonwoven fabric is even better.

[0037] As a preferred embodiment of the flash-evaporated nonwoven fabric of this application, the air permeability of the flash-evaporated nonwoven fabric is greater than or equal to 30.0 mm / s and less than or equal to 50.0 mm / s according to GB / T5453 standard.

[0038] As a preferred embodiment of the flash-evaporated nonwoven fabric of this application, the flash-evaporated nonwoven fabric has a puncture resistance greater than or equal to 7000 J / m according to the GB / T 8809 standard. 2 And less than or equal to 10000 J / m 2 .

[0039] As a preferred embodiment of the flash-steamed nonwoven fabric of this application, the flash-steamed nonwoven fabric has a hydrostatic pressure resistance greater than or equal to 10989 Pa according to GB / T 4744 standard.

[0040] In a second aspect, this application provides a method for preparing flash-evaporated nonwoven fabric, the method comprising the following steps:

[0041] Each component is added to a mixing device containing a solvent, and then heated and nitrogen gas is introduced to make the temperature inside the mixing device greater than or equal to 200°C and less than or equal to 230°C, and the pressure greater than or equal to 10MPa and less than or equal to 12MPa, to obtain a spinning solution.

[0042] The spinning solution is placed in a flash spinning device for spinning and the fiber is received by a receiving device to form a film. The resulting fiber film is then cold-pressed and hot-rolled to obtain flash nonwoven fabric.

[0043] Preferably, the solvent has a boiling point ≤100℃.

[0044] More preferably, the solvent includes at least one of benzene, toluene, butane, pentene, n-hexane, heptane, octane, cyclohexane, dichloromethane, carbon tetrachloride, chloroform, chloromethane, chlorofluoromethane, and chloroethane.

[0045] More preferably, the mass ratio of the solid phase to the liquid phase in the spinning solution is (10-30):(70-90).

[0046] More preferably, the flash spinning device is prepared using the production equipment 300 used in the inventor's prior research and development technology CN115323628B.

[0047] It should be noted that the products of this application are not limited to the production equipment mentioned above. Those skilled in the art can also use other types of flash evaporation production equipment to produce the products according to actual needs, as long as products with the same technical features and effects can be prepared.

[0048] In a third aspect of this application, the use of flash-evaporated nonwoven fabrics in the preparation of medical device packaging products is provided.

[0049] Preferably, the medical device packaging product includes at least one of packaging bags and side-sealed bags.

[0050] More preferably, the medical device packaging product includes the flash-evaporated nonwoven fabric of this application. The flash-evaporated nonwoven fabric is incorporated into the medical device packaging product by at least one of the following methods, including but not limited to interlocking, bonding, or heat sealing. It may be disposed in the central area or the edge area, or it may be disposed on the entire plane.

[0051] More preferably, the flash-evaporated nonwoven fabric is disposed inside or outside the packaging bag or side-sealed bag.

[0052] More preferably, the flash-evaporated nonwoven fabric is disposed in the middle or edge of the packaging bag or side-sealed bag.

[0053] More preferably, the flash-evaporated nonwoven fabric is disposed on a single plane or two planes of the packaging bag or side-sealed bag.

[0054] More preferably, based on the percentage of single-sided planar area, the flash-evaporated nonwoven fabric accounts for more than 8% and less than or equal to 60% of the planar area of ​​the medical device packaging product.

[0055] Specifically, the percentage of flash-evaporated nonwoven fabric in the planar area of ​​medical device packaging products can be one or any two of the following: 8%, 8.5%, 9%, 10%, 10.34%, 10.6%, 15%, 20%, 25%, 50%, 55%, 59%, 60%.

[0056] It should be noted that planar area refers to the total area of ​​a single plane after the medical device packaging product is unfolded. For example, a medical device packaging product is actually a plastic bag formed by symmetrically heat-laminating two planar plastic films. The plastic bag has an opening on one side, so the planar area of ​​the plastic bag is the sum of the planar areas of the two plastic films after it is unfolded.

[0057] For example, the medical device packaging product can be a sealed bag, which is formed by heat bonding two rectangular planes, a first plane and a second plane. A breathable rectangular flash-evaporated nonwoven fabric is provided in the center of the first plane, and the other parts are sealed plastic with low air permeability or no air permeability. The rectangular flash-evaporated nonwoven fabric extends to the edge of the first plane of the sealed bag, so its length is the same as that of the first plane. The width of the flash-evaporated nonwoven fabric is 3 cm, and the length of the first plane is 14.5 cm. The second plane has the same size as the first plane and does not have flash-evaporated nonwoven fabric.

[0058] Therefore, if the length of the two planes is defined as X cm, then the percentage of the planar area of ​​the sealed bag is calculated as 3X / (2×14.5X)×100%=10.34%.

[0059] For example, the medical device packaging product can be a sealed bag, which is formed by heat bonding two rectangular planes, a first plane and a second plane. The edge of the first plane is provided with a breathable rectangular flash-evaporated nonwoven fabric, while the other parts are made of low-permeability or non-permeable sealing plastic. The width of the rectangular flash-evaporated nonwoven fabric is the same as that of the plane. The second plane has the same size as the first plane and is not provided with flash-evaporated nonwoven fabric.

[0060] For example, the medical device packaging product can be a heat-sealed bag, which is formed by heat-sealing two rectangular planes, a first plane and a second plane. The first plane is a flash-evaporated nonwoven fabric, and the second plane is a low-permeability or non-permeable sealing plastic. The two planes are the same size. Therefore, based on the plane area ratio of the heat-sealed bag, the flash-evaporated nonwoven fabric accounts for 50% of the plane area of ​​the side-sealed bag.

[0061] The flash-evaporated nonwoven fabric described in this application, based on its excellent air permeability and performance, can be well applied in medical device packaging products that require ethylene oxide gas sterilization but must also ensure rapid ethylene oxide desorption capability. Whether the sterilized body is a medical device or the packaging product itself, it has the ability to reach the ethylene oxide residue standard faster than existing packaging products. Based on this capability, those skilled in the art can use only a minimum area ratio of 8% of the flash-evaporated nonwoven fabric in the product (the air permeable components of existing packaging products generally account for 10% or more of the area ratio) as the air permeability and desorption component, which can greatly save costs and achieve high economic benefits while ensuring desorption efficiency and performance.

[0062] Compared with the prior art, this application has the following advantages:

[0063] The flash-evaporated nonwoven fabric provided in this application, through the selection of appropriate mass proportions of components, exhibits synergistic effects, resulting in a fabric with high air permeability, high mechanical strength, and excellent waterproof performance. Furthermore, this flash-evaporated nonwoven fabric can be effectively applied in the field of medical device packaging. Due to its high ethylene oxide desorption efficiency, it boasts high reusability in specific applications. Moreover, the raw materials for the flash-evaporated nonwoven fabric provided in this application are widely available, and the preparation method is simple, facilitating practical production. Attached Figure Description

[0064] Figure 1 The image shows a physical product of a medical device packaging bag further prepared from the flash-evaporated nonwoven fabric described in this application, where the white part is the flash-evaporated nonwoven fabric described in this application. Detailed Implementation

[0065] To better illustrate the purpose, technical solution, and advantages of this application, the following detailed description will be provided in conjunction with specific embodiments. Unless otherwise specified, other materials and reagents used in the embodiments are commercially available.

[0066] Polymethylpentene: RT180FG, Mitsui Chemicals,

[0067] Polylactic acid 1: FY602, melting point 165℃, melt index 9g / 10min, Fengyuan Biotechnology.

[0068] Polylactic acid 2: FY401, melting point 175℃, melt index 18g / 10min, Fengyuan Biotechnology.

[0069] Polylactic acid 3 (FY802), melting point 165℃, melt index 4g / 10min, Fengyuan Biotechnology.

[0070] Polylactic acid 4: FY201, melting point 175℃, melt index 30g / 10min, Fengyuan Biotechnology.

[0071] Epoxy resin 1: YD-115, epoxy equivalent is 185g / eq, Guodu Chemical.

[0072] Epoxy resin 2: YD-112, epoxy equivalent is 175g / eq, Guodu Chemical.

[0073] Epoxy resin 3: YD-115CA, epoxy equivalent is 205g / eq, Guodu Chemical.

[0074] SEBS-1: SEBS G1654 HU, 10% by mass toluene solution with a viscosity of 480 cp, Kronen High Performance Polymers Co., Ltd.

[0075] SEBS-2: YH-502, 10% by mass toluene solution with a viscosity of 600 cp, Baling Petrochemical.

[0076] SEBS-3: YH-504, 10% by mass toluene solution with a viscosity of 670 cp, Baling Petrochemical.

[0077] SEBS-4: YH-501, 10% by mass toluene solution with a viscosity of 450 cp, Baling Petrochemical.

[0078] Modified calcium carbonate 1: Surface hydroxyl content is 20 hydroxyl groups / nm 2 ,self made,

[0079] Modified calcium carbonate 2: Surface hydroxyl content is 30 hydroxyl groups / nm 2 ,self made,

[0080] Modified calcium carbonate 3: Surface hydroxyl content is 10 hydroxyl groups / nm 2,self made,

[0081] Modified calcium carbonate 4: Surface hydroxyl content is 50 hydroxyl groups / nm 2 ,self made,

[0082] Modified calcium carbonate 5: Surface hydroxyl content is 5 per nm 2 ,self made,

[0083] Modified calcium carbonate 6: Surface hydroxyl content is 100 hydroxyl groups / nm 2 ,self made,

[0084] The preparation method of modified calcium carbonate 1 includes the following steps:

[0085] An 8% (w / w) calcium hydroxide slurry was added to a carbonation reactor, and carbon dioxide was introduced to carry out the carbonation reaction. When the conductivity dropped to 3 mS / cm, the carbon dioxide was stopped, and starch (15% by mass, based on calcium hydroxide) was added. After stirring for 30 min, carbon dioxide was introduced again to carry out the reaction, and the pH of the system was monitored. When the pH of the system was less than 7, the reaction was stopped, yielding a calcium carbonate suspension. The suspension was then heated to 60℃, and octanoic acid, transglutaminase, and pyridine were added. The reaction was carried out for 2 h (10% by mass of octanoic acid, 0.5% by mass of transglutaminase, and 5% by mass of pyridine, based on starch). After the reaction was completed, the mixture was filtered, the solid was collected, dried, pulverized, and sieved to obtain modified calcium carbonate 1.

[0086] The modified calcium carbonate 2-6 was prepared by changing the mass percentage of starch, reaction temperature and time, and the amount of octanoic acid, transglutaminase, and pyridine added to achieve modified calcium carbonate with different surface hydroxyl contents.

[0087] Examples 1-14 and Comparative Examples 1-8

[0088] This application provides a flash-evaporated nonwoven fabric in its embodiments and comparative examples. The composition (parts by weight) of the flash-evaporated nonwoven fabric is shown in Tables 1-2.

[0089] Table 1

[0090]

[0091]

[0092] Table 2

[0093]

[0094]

[0095] The method for preparing flash-evaporated nonwoven fabric provided in Example 1 includes the following steps:

[0096] (1) Masterbatch preparation: Polymethylpentene, polylactic acid, epoxy resin, styrene-ethylene-butene-styrene block copolymer, and modified calcium carbonate are mixed and then melt-extruded and granulated in a twin-screw extruder at 90-180℃ to obtain the masterbatch. The temperature settings of the twin-screw extruder are as follows: Zone 1 90-110℃, Zone 2 120-130℃, Zone 3 150-160℃, Zone 4 170-180℃, Zone 5 170-185℃, Zone 6 170-185℃, Zone 7 160-165℃, Zone 8 160-165℃, Zone 9 160-165℃, Zone 10 160-165℃. The screw speed of the twin-screw extruder is 180-220 rpm.

[0097] (2) Preparation of spinning solution: The masterbatch was transferred to a reaction vessel containing a mixed solvent (15%:85%) of difluorochloromethane and tetrafluorodichloroethane. The mixture was preheated to 180°C, then pressurized to 12 MPa by introducing nitrogen gas, and finally heated to 225°C and stirred in a sealed container for 2 hours. After the temperature stabilized, the spinning solution was obtained. The mass ratio of the solid phase to the liquid phase in the spinning solution was 15:85.

[0098] (3) Preparation of flash nonwoven fabric: Referring to CN115323628B, a flash spinning equipment 300 was used to transfer the spinning solution to the nozzle for spinning. The filaments were then refracted and reflected by a rotating splitting plate to form a mesh and laid on a moving screen. The speed of the ejected airflow was 12000 m / min, the frequency of the rotating splitting plate was 35 Hz, and the forward speed of the moving screen was 45 m / min. The collected mesh was cold-pressed at 0.5-1 MPa and hot-rolled at 140℃ and 3-3.5 MPa (hot rolling roller speed was 45-50 m / min) to obtain a flash nonwoven fabric with a thickness of about 0.12 mm.

[0099] The preparation methods of the flash-evaporated nonwoven fabrics provided in Examples 2-13 and Comparative Examples 1-8 are consistent with the preparation method in Example 1.

[0100] Example of effect

[0101] The performance of the flash-evaporated nonwoven fabrics prepared in Examples 1-14 and Comparative Examples 1-8 is verified by the following steps:

[0102] (1) Air permeability performance: Tested according to GB / T 5453 (area 20cm²). 2 (pressure difference 200Pa)

[0103] (2) Puncture resistance: Tested according to GB / T 8809.

[0104] (3) Hydrostatic pressure resistance: Tested according to GB / T 4744 (pressure increase rate 6 kPa / min),

[0105] (4) Ethylene oxide desorption performance: The products of each example and comparative example (total area 20 cm²) were compared. 2 Preparation of commercially available polypropylene films by hot pressing, such as... Figure 1 The center-seal bag shown has a flash-evaporated nonwoven fabric covering 20% ​​of its planar area. The bag was then sterilized according to GB / T 18279, with the following sterilization parameters: ethylene oxide concentration of 725 ppm, maximum temperature of 55℃, maximum relative humidity of 60%, and contact time with ethylene oxide of 8 hours. After standing for 24 hours at 50℃ and 20% relative humidity, the residual ethylene oxide content was tested using gas chromatography.

[0106] The test results are shown in Table 3.

[0107] Table 3

[0108]

[0109]

[0110] As shown in Table 3, when the technical solution provided in this application is adopted, the resulting flash-evaporated nonwoven fabric exhibits excellent air permeability, mechanical strength, water resistance, and reusability. Specifically, the obtained flash-evaporated nonwoven fabric has an air permeability of over 43.0 mm / s and a puncture resistance of 70-120 J / m. 2 The above properties have a hydrostatic pressure resistance of over 10989 Pa and an ethylene oxide residue of less than 7.3 μg / g.

[0111] As can be seen from Examples 1-3 and Comparative Examples 1-2, the mass fraction of components in flash-spun nonwoven fabric has a significant impact on the performance of the product. When the mass fraction of modified calcium carbonate in Comparative Examples 1-2 is outside the range given in this application, the air permeability, waterproof performance, or mechanical properties of the obtained product decrease to a certain extent. Furthermore, the desorption efficiency of the obtained product for ethylene oxide gas also shows a significant downward trend. This is because when there is too little modified calcium carbonate, it cannot effectively form a microporous structure, resulting in a decrease in the air permeability of the product, which in turn leads to a significant decrease in the desorption efficiency for ethylene oxide. At the same time, when there is too much modified calcium carbonate, although it will form a better microporous structure and maintain relatively good air permeability of the product, it will reduce the mechanical properties and waterproof performance of the product to a certain extent. Moreover, due to the addition of too many micropores, the adsorption capacity with ethylene oxide is stronger, which leads to a certain downward trend in the subsequent desorption efficiency of ethylene oxide.

[0112] As can be seen from Examples 1 and 4-6, Examples 1 and 7-8, and Examples 1 and 9-11, the specific selection of the melting point and melt index of polylactic acid, the epoxy equivalent of epoxy resin, and the viscosity of SEBS 10% by mass toluene solution will also affect the overall performance of the product. When the parameters of the above components are further selected within the range defined in this application, the overall performance of the obtained product is better.

[0113] As can be seen from Examples 1, 9-14 and Comparative Examples 3-5, the content of hydroxyl groups on the surface of modified calcium carbonate also affects the performance of the product. When the content of hydroxyl groups on the surface of modified calcium carbonate in Comparative Examples 3-4 is not within the given range, the desorption efficiency of the obtained product for ethylene oxide is significantly reduced. When unmodified calcium carbonate is used in Comparative Example 5, the technical effect corresponding to this application cannot be achieved.

[0114] As can be seen from Examples 1 and Comparative Examples 6-8, the overall performance of the products obtained is significantly reduced when the components in this application are not added or when other types of components are substituted.

[0115] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit the scope of protection of this application. Although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this application without departing from the substance and scope of the technical solutions of this application.

Claims

1. A flash-evaporated nonwoven fabric, characterized in that, The flash-evaporated nonwoven fabric comprises the following components in parts by weight: 60-90 parts of polymethylpentene, 4-15 parts of polylactic acid, 4-10 parts of epoxy resin, 1-5 parts of styrene-ethylene-butene-styrene block copolymer, and 2-10 parts of modified calcium carbonate. The modified calcium carbonate has a surface hydroxyl content of greater than or equal to 10 hydroxyl groups / nm. 2 And less than or equal to 50 per nm 2 ; The method for preparing the modified calcium carbonate includes the following steps: carbon dioxide is introduced into a calcium hydroxide slurry, starch is added and stirred, and then carbon dioxide is continued to be introduced until the system becomes acidic. Then, an esterification modifier and a catalyst are added to carry out an in-situ esterification reaction. After the reaction is completed, the mixture is filtered, dried, and pulverized to obtain modified calcium carbonate.

2. The flash-evaporated nonwoven fabric according to claim 1, characterized in that, The flash-evaporated nonwoven fabric comprises the following components in parts by weight: 70-80 parts of polymethylpentene, 6-10 parts of polylactic acid, 6-8 parts of epoxy resin, 3-4 parts of styrene-ethylene-butene-styrene block copolymer, and 6-8 parts of modified calcium carbonate.

3. The flash-evaporated nonwoven fabric according to claim 1, characterized in that, The modified calcium carbonate has a surface hydroxyl content of ≥20 hydroxyl groups / nm. 2 And less than or equal to 30 per nm 2 .

4. The flash-evaporated nonwoven fabric according to claim 1, characterized in that, The polylactic acid has a melting point greater than or equal to 165°C and less than or equal to 175°C; And / or, the melt index of the polylactic acid is greater than or equal to 9 g / 10 min and less than or equal to 18 g / 10 min.

5. The flash-evaporated nonwoven fabric according to claim 1, characterized in that, The epoxy equivalent of the epoxy resin is greater than or equal to 180 g / eq and less than or equal to 190 g / eq; And / or, the viscosity of a 10% by mass toluene solution of the styrene-ethylene-butene-styrene block copolymer is greater than or equal to 480 cp and less than or equal to 600 cp.

6. The flash-evaporated nonwoven fabric according to claim 1, characterized in that, The air permeability of the flash-evaporated nonwoven fabric is greater than or equal to 30.0 mm / s and less than or equal to 50.0 mm / s according to GB / T5453-1997 standard; And / or, the flash-spun nonwoven fabric has a puncture resistance greater than or equal to 7000 J / m according to GB / T 8809-2015 standard. 2 And less than or equal to 10000 J / m 2 And / or, the flash-evaporated nonwoven fabric has a hydrostatic pressure resistance greater than or equal to 10989 Pa according to GB / T 4744-2013 standard.

7. The method for preparing flash-evaporated nonwoven fabric according to any one of claims 1 to 6, characterized in that, The preparation method includes the following steps: Each component is added to a mixing device containing a solvent, and then heated and nitrogen gas is introduced to make the temperature inside the mixing device greater than or equal to 200°C and less than or equal to 230°C, and the pressure greater than or equal to 10MPa and less than or equal to 12MPa, to obtain a spinning solution. The spinning solution is placed in a flash spinning device for spinning and the fiber is received by a receiving device to form a film. The resulting fiber film is then cold-pressed and hot-rolled to obtain flash nonwoven fabric.

8. The use of the flash-evaporated nonwoven fabric as described in any one of claims 1 to 6 in the preparation of medical device packaging products.

9. The application according to claim 8, characterized in that, The medical device packaging product includes at least one of a packaging bag and a side-sealed bag, and the medical device packaging product contains the flash-evaporated nonwoven fabric according to any one of claims 1 to 6, wherein the flash-evaporated nonwoven fabric accounts for more than or equal to 8% and less than or equal to 60% of the planar area of ​​the medical device packaging product.

10. The application according to claim 8, characterized in that, The flash-evaporated nonwoven fabric is incorporated into the medical device packaging product by at least one of the following methods: interlocking, bonding, and heat sealing.

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