Metallocene polypropylene composite material for soft antibacterial spun-bonded non-woven fabric and application of metallocene polypropylene composite material

Abstract

The invention discloses a metallocene polypropylene composite material for a soft antibacterial spun-bonded non-woven fabric, which is prepared from the following raw materials in parts by mass: 58.82 to 78.06 parts of metallocene isotactic polypropylene, 10 to 15 parts of polypropylene random copolymer, 0 to 9.0 parts of allyl elastomer, 10 to 20 parts of high-density polyethylene, 0.10 to 0.18 part of hindered hydroxylamine ester degradation agent, 0.1 to 0.4 part of AC foaming agent, 1.4 to 1.6 parts of nano zinc oxide and 0.12 to 0.15 part of hindered phenol antioxidant. And 0.12 to 0.15 part of a phosphate ester antioxidant. According to the metallocene polypropylene composite material for the soft antibacterial spun-bonded non-woven fabric, the metallocene isotactic polypropylene serves as base resin, the flexibility of the metallocene polypropylene composite material is improved with the assistance of the polypropylene random copolymer, the hindered hydroxylamine ester degradation agent is adopted for moderately controlling degradation, a proper amount of the AC foaming agent is added, and high-density polyethylene and other components are combined, so that the soft antibacterial spun-bonded non-woven fabric is obtained. The obtained metallocene isotactic polypropylene composite material has excellent processability and better flexibility, and is suitable for spunbond non-woven fabric special materials.

Description

Technical Field

[0001] This invention relates to the field of polymer composite materials, specifically to a metallocene polypropylene composite material for soft antibacterial spunbond nonwoven fabrics and its applications. Background Technology

[0002] The increased demand for meltblown nonwoven fabric, a key component for medical masks, as well as spunbond nonwoven fabric and spunbond-meltblown-spunbond composite nonwoven fabric (SMS nonwoven fabric) used in protective clothing, has driven the development of China's nonwoven fabric industry. Consequently, nonwoven fabric-specific materials, processing technologies, and processing aids have all seen significant improvements.

[0003] However, due to the structural and crystalline characteristics of isotactic homopolymer polypropylene produced by the Ziegler-Natta catalyst system, polypropylene-based nonwoven fabrics also have many defects, such as stiff fibers and poor skin affinity. To give nonwoven fabrics better barrier and filtration properties (by adding electret components), their hydrophilicity must be sacrificed, even though hydrophilicity can improve skin affinity. Conversely, improving breathability and comfort also sacrifices barrier and filtration performance. Filtration performance is crucial for ensuring the antibacterial and antiviral properties of protective equipment. Therefore, nonwoven fabric manufacturers have taken various measures to improve skin affinity while ensuring high filtration performance. For example, adding VistaMAXX propylene-based elastomer from Exxonmobil to improve softness, and adding L-MODU S900 rheology modifier from Idemitsu to improve the processing properties of nonwoven fabric materials to obtain finer and softer fibers. While these measures improve the softness of nonwoven fibers and enhance skin-friendliness to some extent, the excessive softness of the fibers may lead to disordered stacking, which in turn increases filtration pressure, reduces fiber moisture permeability, and may cause discomfort. Summary of the Invention

[0004] In view of this, the present invention provides a metallocene polypropylene composite material for soft antibacterial spunbond nonwoven fabric and its application. The nonwoven fabric made from the metallocene polypropylene composite material has excellent softness and antibacterial properties, and is safe to use.

[0005] To achieve the above objectives, the present invention provides a metallocene polypropylene composite material for soft antibacterial spunbond nonwoven fabrics, comprising the following raw materials by mass fraction:

[0006] Metallocene isotactic polypropylene, 58.82–78.06 parts

[0007] 10-15 parts of random copolymer polypropylene

[0008] 0 to 9.0 parts of acrylic elastomer

[0009] 10-20 parts of high-density polyethylene

[0010] 0.10–0.18 parts of hindered hydroxylamine ester degradative agent

[0011] AC foaming agent 0.1-0.4 parts

[0012] 1.4–1.6 parts of nano zinc oxide

[0013] 0.12–0.15 parts of hindered phenolic antioxidants

[0014] Phosphate ester antioxidants: 0.12–0.15 parts.

[0015] In one optional embodiment, the melt flow rate (230°C, 2.16 kg) of the metallocene isotactic polypropylene is 10–100 g / 10 min, and the isotacticity is above 95%. Preferably, the melt flow rate (230°C, 2.16 kg) of the metallocene isotactic polypropylene is 30–60 g / 10 min, and the isotacticity is above 97%.

[0016] In one optional embodiment, the melt flow rate (230°C, 2.16 kg) of the random copolymer polypropylene is 10–50 g / 10 min; preferably, the melt flow rate (230°C, 2.16 kg) of the random copolymer polypropylene is 20–30 g / 10 min.

[0017] In one optional embodiment, the melt flow rate (190°C, 2.16 kg) of the propylene-based elastomer is 5–20 g / 10 min. Preferably, the melt flow rate (190°C, 2.16 kg) of the propylene-based elastomer is 9–15 g / 10 min.

[0018] In one alternative embodiment, the melt flow rate (190°C, 2.16 kg) of the high-density polyethylene is 10–30 g / 10 min.

[0019] In one optional embodiment, the hindered hydroxylamine ester degrader has a melting temperature of 100–180°C and an apparent density (20°C) of 0.45–0.55 g / cm³. 3 Preferably, the hindered hydroxylamine ester degrading agent is Irgatec CR76IC.

[0020] In one optional embodiment, the hindered phenolic antioxidant is antioxidant 1010 (chemical name: pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid] ester);

[0021] The phosphate ester antioxidant is antioxidant 168 (chemical name tris[2,4-di-tert-butylphenyl]phosphite);

[0022] The average particle size of the nano-zinc oxide is 50 nm, and the specific surface area is 30 ± 10 m². 2 / g;

[0023] The AC foaming agent is azodicarbonamide.

[0024] The metallocene polypropylene composite material for soft antibacterial spunbond nonwoven fabric provided by this invention can be used in the preparation of air filtration materials, liquid filtration materials, isolation materials, absorbent materials, or medical materials. Specifically, for example:

[0025] The present invention also provides a soft antibacterial spunbond nonwoven fabric, which is made from the above-mentioned soft antibacterial spunbond nonwoven fabric using a metallocene polypropylene composite material.

[0026] The present invention also provides a method for preparing the above-mentioned soft antibacterial spunbond nonwoven fabric, comprising the following steps:

[0027] Mixing: Metallocene isotactic polypropylene, random copolymer polypropylene, high-density polyethylene, hindered hydroxylamine ester degradative agent, nano zinc oxide, hindered phenolic antioxidant, and phosphate ester antioxidant are mixed sequentially to obtain a premix; or

[0028] Metallocene isotactic polypropylene, random copolymer polypropylene, propylene-based elastomer, high-density polyethylene, hindered hydroxylamine ester degradative agent, nano zinc oxide, hindered phenolic antioxidant, and phosphate ester antioxidant are mixed sequentially to obtain a premix.

[0029] Granulation: The premix is ​​extruded and granulated to obtain the complex;

[0030] Foaming: The composite is mixed with AC foaming agent to obtain a mixture;

[0031] Spunbond: The mixture is spunbonded to obtain the soft antibacterial spunbond nonwoven fabric.

[0032] In one optional embodiment, the mixing step is carried out in a high-speed mixer at a temperature of 30–50°C, a rotation speed of 300–500 rpm, and a mixing time of 3–5 minutes.

[0033] In one optional embodiment, the granulation step is performed in a twin-screw extruder. The twin-screw extruder is a parallel co-rotating twin-screw extruder with a length-to-diameter ratio of 40:1 and a screw diameter of 30 mm. The feeder speed is set to 10–30 rpm, and the screw speed is 200–500 rpm. The temperature of each section of the extruder is 160–290–160°C (from the feed port to the die). The vacuum degree is 750 mm Hg. An automatic screen changing mechanism is installed on the die head. The filter screen is four layers stacked in the order of 200 mesh / 300 mesh / 300 mesh / 200 mesh, and the screen is automatically changed every 10 minutes.

[0034] In one alternative embodiment, the granulation process employs cold water strip cutting.

[0035] In one optional embodiment, during the foaming step, the composite and the AC foaming agent are mixed in a high-speed mixer at a mixing temperature of 35–45°C for 3 minutes and at a mixer speed of 150 rpm.

[0036] In one optional embodiment, the spunbonding step involves preparing spunbond nonwoven fabric on a spunbonding machine with a width of 100 mm, and the spunbond nonwoven fabric processing technology is set as follows:

[0037] Extruder screw temperature 175-225℃

[0038] Extruder die temperature 230℃

[0039] Metering pump speed 10 rpm

[0040] Hot pressing temperature: 130-135℃.

[0041] Compared with the prior art, the present invention has at least the following advantages:

[0042] Beneficial Effect 1: The metallocene polypropylene composite material for soft antibacterial spunbond nonwoven fabric provided by this invention uses metallocene isotactic polypropylene as the base resin, supplemented with random copolymer polypropylene to increase its softness, moderately controlled degradation by hindered hydroxylamine ester degrading agent, and an appropriate amount of AC foaming agent, combined with high-density polyethylene and other components, to obtain a metallocene isotactic polypropylene composite material with excellent processing performance and better flexibility, which is suitable for special materials for spunbond nonwoven fabric.

[0043] Beneficial Effect 2: The metallocene polypropylene composite material for soft antibacterial spunbond nonwoven fabric provided by this invention utilizes the advantages of metallocene polypropylene, such as high crystallinity, smaller crystal size, narrow molecular weight distribution, and good processing performance. Using it as the base resin, the spunbond nonwoven fabric made by combining it with other components has both good softness and good filtration barrier performance, while also having low filtration pressure. Even with the addition of propylene-based elastomer components, finer and softer fibers are obtained, while still maintaining high filtration performance and low filtration pressure.

[0044] Beneficial Effect 3: The metallocene polypropylene composite material for soft antibacterial spunbond nonwoven fabric provided by this invention can achieve controlled degradation of mPP more effectively by selecting the hindered hydroxylamine ester degrading agent Irgatec CR 76IC as the degrading agent for moderate controlled degradation (mainly for the controlled degradation of a very small amount of ultra-high molecular weight polypropylene produced in the polypropylene polymerization due to the high catalyst activity), thereby obtaining a special material for spunbond nonwoven fabric with good processing performance and better flexibility.

[0045] Beneficial Effect 4: The metallocene polypropylene composite material for soft antibacterial spunbond nonwoven fabric provided by the present invention, by adding an appropriate amount of AC foaming agent, causes the micro-bubbles generated to randomly squeeze the fibers at the spinneret of the spunbond nonwoven fabric unit, causing the fibers to bend in a moderately disordered manner, increasing the softness and crimp of the spunbond nonwoven fabric fibers, making it softer.

[0046] Beneficial Effect 5: The metallocene polypropylene composite material for soft antibacterial spunbond nonwoven fabric provided by the present invention can significantly improve the melt strength of the metallocene polypropylene composite material by adding high-density polyethylene during the compounding process of metallocene isotactic polypropylene as the base resin. This is beneficial for preserving the foaming gas and preventing it from escaping prematurely. Moreover, the flexibility of high-density polyethylene is also better than that of metallocene isotactic polypropylene. In other words, the addition of high-density polyethylene is also beneficial for improving the flexibility of the composite material.

[0047] Beneficial Effect 6: The metallocene polypropylene composite material for soft antibacterial spunbond nonwoven fabric provided by this invention, when nano zinc oxide is added during melt mixing, can form cell nucleation centers for AC foaming agent during spunbond nonwoven fabric processing, thereby improving the foaming efficiency of AC foaming agent, reducing bubble size, preventing excessively large bubbles from blocking melt extrusion, and also imparting a certain antibacterial effect to spunbond nonwoven fabric, thus playing the role of a dual-function additive. Detailed Implementation

[0048] The present invention will now be described in detail through embodiments. It should be noted that the following embodiments are only for further illustration of the present invention and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above description.

[0049] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0050] Raw material source:

[0051] All the raw materials specified in this invention can satisfy the implementation of the invention. However, for ease of comparison, the following raw materials are used in the following embodiments and comparative examples:

[0052] Metallocene isotactic polypropylene, Exxon Mobil's Achieve™ Advanced PP1605, with isotacticity above 98% and melt flow rate of 32 g / 10 min (230 °C, 2.16 kg).

[0053] Random copolymer polypropylene, Yanshan Petrochemical's K4818, has a melt flow rate of 22.4 g / 10 min (230℃, 2.16 kg).

[0054] The propylene-based elastomer, VistaMaxx 6202 from ExxonMobil, has a melt flow rate of approximately 9.1 g / 10 min.

[0055] High-density polyethylene, Fujian United Petrochemical's DMDA8920, has a melt flow rate of 20g / 10min (190℃, 2.16kg);

[0056] The hindered hydroxylamine ester degrader, BASF's Irgatec CR 76IC, has a melting temperature between 100 and 180°C and an apparent density (at 20°C) of 0.45–0.55 g / cm³. 3 ;

[0057] AC foaming agent, a product of Chengdu Jiude Environmental Protection Technology Co., Ltd., with a purity of ≥98%;

[0058] Nano zinc oxide, DK-ZnO-F50 from Beijing Deco Island Gold Technology Co., Ltd., has an average particle size of 50nm, a purity of ≥99.5%, and a specific surface area of ​​30±10m². 2 / g;

[0059] Hindered phenolic antioxidants, such as BASF's IRGANOX 1010 (antioxidant 1010);

[0060] Phosphate ester antioxidants, such as BASF's IRGAFOS 168 (antioxidant 168).

[0061] Evaluation and analysis methods:

[0062] The melt flow rate (MFR) of metallocene polypropylene composites was determined according to the national standard GB / T 3682.1-2018. The test conditions were 230℃ and 2.16kg load.

[0063] Crystal points (fisheyes) in metallocene polypropylene and its composites were determined according to the national standard GB / T 6595-1986.

[0064] The deviation rate of unit area mass and the coefficient of variation of unit area mass of spunbond nonwoven fabric were determined according to the national standard GB / T24218.1.

[0065] The breaking strength, elongation at break in the elastic direction, and permanent deformation rate in the elastic direction of spunbond nonwoven fabrics were determined using the national standard GB / T24218.3.

[0066] According to the judgment criteria of textile industry standard FZ / T 64092-2022, spunviscose nonwoven fabrics can be divided into low-elasticity and high-elasticity types based on the permanent deformation rate in the elastic direction. Low-elasticity spunviscose nonwoven fabrics have a permanent deformation rate >30% and ≤60%, while high-elasticity spunviscose nonwoven fabrics have a permanent deformation rate ≤30%.

[0067] The antibacterial properties of spunbond nonwoven fabrics were tested according to GB / T 20944.3-2008 "Evaluation of antibacterial properties of textiles - Part 3: Vibration method", with Staphylococcus aureus and Escherichia coli used as the bacterial strains.

[0068] Example 1

[0069] This embodiment provides a soft, antibacterial spunbond nonwoven fabric, the preparation method of which specifically includes the following steps:

[0070] Weigh the raw materials according to the following proportions: 78.06 parts by weight of metallocene isotactic polypropylene; 10 parts by weight of random copolymer polypropylene; 10 parts by weight of high-density polyethylene; 0.1 parts by weight of degradation agent CR76; 1.4 parts by weight of nano zinc oxide; 0.12 parts by weight of antioxidant 1010; and 0.12 parts by weight of co-antioxidant 168.

[0071] Metallocene isotactic polypropylene, random copolymer polypropylene, high-density polyethylene, degradation agent CR76, nano zinc oxide, antioxidant 1010 and co-antioxidant 168 were sequentially added to a high-speed mixer for premixing. The mixing temperature was 30℃, the rotation speed was 350 rpm, and the mixing time was 5 minutes to obtain a premix of metallocene polypropylene composite.

[0072] The premix was then extruded and granulated using a parallel co-rotating twin-screw extruder with a length-to-diameter ratio of 40:1 and a screw diameter of 30 mm. The extrusion compounding unit process conditions were as follows: feeder speed was set to 20 rpm; screw speed was set to 200 rpm; temperature of each section of the extruder was 160–290–160℃ (from the feed inlet to the die); vacuum degree was 750 mm Hg; an automatic screen changing mechanism was installed on the die head, and the filter screen was stacked in four layers in the order of 200 mesh / 300 mesh / 300 mesh / 200 mesh; cold water was used for strip cutting to obtain a metallocene polypropylene composite for spunbond nonwoven fabric with stable melt flow rate.

[0073] The above-mentioned soft antibacterial spunbond nonwoven fabric metallocene polypropylene composite material was added to a high-speed mixer along with 0.2 parts by weight of AC foaming agent. The mixing temperature was 35-45℃, the mixing time was 3 minutes, and the mixer speed was 150 rpm. After uniform mixing, spunbond nonwoven fabric was prepared on a spunbond machine with a width of 100 mm. The processing technology for the spunbond nonwoven fabric was set as follows:

[0074] Extruder screw temperature 175-225℃

[0075] Extruder die temperature 230℃

[0076] Metering pump speed 10 rpm

[0077] Hot pressing temperature 130~135℃

[0078] The relevant properties of the obtained metallocene polypropylene composite material and spunbond nonwoven fabric were tested according to the above-mentioned standards and experimental methods, and the results are shown in Table 1.

[0079] Example 2

[0080] This embodiment provides a soft, antibacterial spunbond nonwoven fabric, the preparation method of which specifically includes the following steps:

[0081] Weigh the raw materials according to the following proportions: 65.57 parts by weight of metallocene isotactic polypropylene; 12 parts by weight of random copolymer polypropylene; 5 parts by weight of propylene-based elastomer; 15 parts by weight of high-density polyethylene; 0.13 parts by weight of degradation agent CR76; 1.6 parts by weight of nano zinc oxide; 0.15 parts by weight of antioxidant 1010; and 0.15 parts by weight of co-antioxidant 168.

[0082] Metallocene isotactic polypropylene, random copolymer polypropylene, propylene-based elastomer, high-density polyethylene, degradation agent CR76, nano zinc oxide, antioxidant 1010 and co-antioxidant 168 were sequentially added to a high-speed mixer for premixing. The mixing temperature was 40℃, the rotation speed was 300 rpm, and the mixing time was 4 minutes to obtain a premix of metallocene polypropylene composite.

[0083] The premix was then extruded and granulated using a parallel co-rotating twin-screw extruder with a length-to-diameter ratio of 40:1 and a screw diameter of 30 mm. The extrusion compounding unit process conditions were as follows: feeder speed was set to 25 rpm; screw speed was 250 rpm; temperature of each section of the extruder was 160–290–160℃ (from the feed inlet to the die); vacuum degree was 750 mm Hg; an automatic screen changing mechanism was installed on the die head, and the filter screen was stacked in four layers in the order of 200 mesh / 300 mesh / 300 mesh / 200 mesh; cold water was used for strip cutting to obtain a metallocene polypropylene composite for spunbond nonwoven fabric with stable melt flow rate.

[0084] The above-mentioned soft antibacterial spunbond nonwoven fabric metallocene polypropylene composite material was added to a high-speed mixer along with 0.4 parts by weight of AC foaming agent. The mixing temperature was 35-45℃, the mixing time was 3 minutes, and the mixer speed was 150 rpm. After uniform mixing, spunbond nonwoven fabric was prepared on a spunbond machine with a width of 100 mm. The processing technology for the spunbond nonwoven fabric was set as follows:

[0085] Extruder screw temperature 175-225℃

[0086] Extruder die temperature 230℃

[0087] Metering pump speed 10 rpm

[0088] Hot pressing temperature 130~135℃

[0089] The relevant properties of the obtained metallocene polypropylene composite material and spunbond nonwoven fabric were tested according to the above-mentioned standards and experimental methods, and the results are shown in Table 1.

[0090] Example 3

[0091] This embodiment provides a soft, antibacterial spunbond nonwoven fabric, the preparation method of which specifically includes the following steps:

[0092] Weigh the raw materials according to the following proportions: 58.82 parts by weight of metallocene isotactic polypropylene; 15 parts by weight of random copolymer polypropylene; 4 parts by weight of propylene-based elastomer; 20 parts by weight of high-density polyethylene; 0.1 parts by weight of degradation agent CR76; 1.5 parts by weight of nano zinc oxide; 0.14 parts by weight of antioxidant 1010; and 0.14 parts by weight of co-antioxidant 168.

[0093] Metallocene isotactic polypropylene, random copolymer polypropylene, propylene-based elastomer, high-density polyethylene, degradation agent CR76, nano zinc oxide, antioxidant 1010 and co-antioxidant 168 were sequentially added to a high-speed mixer for premixing. The mixing temperature was 50℃, the rotation speed was 500 rpm, and the mixing time was 3 minutes to obtain a premix of metallocene polypropylene composite.

[0094] The premix was then extruded and granulated using a parallel co-rotating twin-screw extruder with a length-to-diameter ratio of 40:1 and a screw diameter of 30 mm. The extrusion compounding unit process conditions were as follows: feeder speed was set to 30 rpm; screw speed was 300 rpm; temperature of each section of the extruder was 160–290–160℃ (from the feed inlet to the die); vacuum degree was 750 mm Hg; an automatic screen changing mechanism was installed on the die head, and the filter screen was stacked in four layers in the order of 200 mesh / 300 mesh / 300 mesh / 200 mesh; cold water was used for strip cutting to obtain a metallocene polypropylene composite for spunbond nonwoven fabric with stable melt flow rate.

[0095] The above-mentioned soft antibacterial spunbond nonwoven fabric metallocene polypropylene composite material was added to a high-speed mixer along with 0.3 parts by weight of AC foaming agent. The mixing temperature was 35-45℃, the mixing time was 3 minutes, and the mixer speed was 150 rpm. After uniform mixing, spunbond nonwoven fabric was prepared on a spunbond machine with a width of 100 mm. The processing technology for the spunbond nonwoven fabric was set as follows:

[0096] Extruder screw temperature 175-225℃

[0097] Extruder die temperature 230℃

[0098] Metering pump speed 10 rpm

[0099] Hot pressing temperature 130~135℃

[0100] The relevant properties of the obtained metallocene polypropylene composite material and spunbond nonwoven fabric were tested according to the above-mentioned standards and experimental methods, and the results are shown in Table 1.

[0101] Example 4

[0102] This embodiment provides a soft, antibacterial spunbond nonwoven fabric, the preparation method of which specifically includes the following steps:

[0103] Weigh the raw materials according to the following proportions: 68.06 parts by weight of metallocene isotactic polypropylene; 13 parts by weight of random copolymer polypropylene; 7 parts by weight of propylene-based elastomer; 10 parts by weight of high-density polyethylene; 0.18 parts by weight of degradation agent CR76; 1.4 parts by weight of nano zinc oxide; 0.13 parts by weight of antioxidant 1010; and 0.13 parts by weight of co-antioxidant 168.

[0104] Metallocene isotactic polypropylene, random copolymer polypropylene, propylene-based elastomer, high-density polyethylene, degradation agent CR76, nano zinc oxide, antioxidant 1010 and co-antioxidant 168 were sequentially added to a high-speed mixer for premixing. The mixing temperature was 35℃, the rotation speed was 350 rpm, and the mixing time was 4 minutes to obtain a premix of metallocene polypropylene composite.

[0105] The premix was then extruded and granulated using a parallel co-rotating twin-screw extruder with a length-to-diameter ratio of 40:1 and a screw diameter of 30 mm. The extrusion compounding unit process conditions were as follows: feeder speed was set to 10 rpm; screw speed was 400 rpm; temperature of each section of the extruder was 160–290–160℃ (from the feed inlet to the die); vacuum degree was 750 mm Hg; an automatic screen changing mechanism was installed on the die head, and the filter screen was stacked in four layers in the order of 200 mesh / 300 mesh / 300 mesh / 200 mesh; cold water was used for strip cutting to obtain a metallocene polypropylene composite for spunbond nonwoven fabric with stable melt flow rate.

[0106] The above-mentioned soft antibacterial spunbond nonwoven fabric metallocene polypropylene composite material was added to a high-speed mixer along with 0.1 parts by weight of AC foaming agent. The mixing temperature was 35-45℃, the mixing time was 3 minutes, and the mixer speed was 150 rpm. After uniform mixing, spunbond nonwoven fabric was prepared on a spunbond machine with a width of 100 mm. The processing technology for the spunbond nonwoven fabric was set as follows:

[0107] Extruder screw temperature 175-225℃

[0108] Extruder die temperature 230℃

[0109] Metering pump speed 10 rpm

[0110] Hot pressing temperature 130~135℃

[0111] The relevant properties of the obtained metallocene polypropylene composite material and spunbond nonwoven fabric were tested according to the above-mentioned standards and experimental methods, and the results are shown in Table 1.

[0112] Example 5

[0113] This embodiment provides a soft, antibacterial spunbond nonwoven fabric, the preparation method of which specifically includes the following steps:

[0114] Weigh the raw materials according to the following proportions: 61.70 parts by weight of metallocene isotactic polypropylene; 12 parts by weight of random copolymer polypropylene; 9 parts by weight of propylene-based elastomer; 15 parts by weight of high-density polyethylene; 0.16 parts by weight of degradation agent CR76; 1.5 parts by weight of nano zinc oxide; 0.12 parts by weight of antioxidant 1010; and 0.12 parts by weight of co-antioxidant 168.

[0115] Metallocene isotactic polypropylene, random copolymer polypropylene, propylene-based elastomer, high-density polyethylene, degradation agent CR76, nano zinc oxide, antioxidant 1010 and co-antioxidant 168 were sequentially added to a high-speed mixer for premixing. The mixing temperature was 30°C, the rotation speed was 400 rpm, and the mixing time was 3 minutes to obtain a premix of metallocene polypropylene composite.

[0116] The premix was then extruded and granulated using a parallel co-rotating twin-screw extruder with a length-to-diameter ratio of 40:1 and a screw diameter of 30 mm. The extrusion compounding unit process conditions were as follows: feeder speed was set to 30 rpm; screw speed was 500 rpm; temperature of each section of the extruder was 160–290–160℃ (from the feed inlet to the die); vacuum degree was 750 mm Hg; an automatic screen changing mechanism was installed on the die head, and the filter screen was stacked in four layers in the order of 200 mesh / 300 mesh / 300 mesh / 200 mesh; cold water was used for strip cutting to obtain a metallocene polypropylene composite for spunbond nonwoven fabric with stable melt flow rate.

[0117] The above-mentioned soft antibacterial spunbond nonwoven fabric metallocene polypropylene composite material was added to a high-speed mixer along with 0.4 parts by weight of AC foaming agent. The mixing temperature was 35-45℃, the mixing time was 3 minutes, and the mixer speed was 150 rpm. After uniform mixing, spunbond nonwoven fabric was prepared on a spunbond machine with a width of 100 mm. The processing technology for the spunbond nonwoven fabric was set as follows:

[0118] Extruder screw temperature 175-225℃

[0119] Extruder die temperature 230℃

[0120] Metering pump speed 10 rpm

[0121] Hot pressing temperature 130~135℃

[0122] The relevant properties of the obtained metallocene polypropylene composite material and spunbond nonwoven fabric were tested according to the above-mentioned standards and experimental methods, and the results are shown in Table 1.

[0123] Comparative Example 1

[0124] This comparative example provides a soft, antibacterial spunbond nonwoven fabric, the preparation method of which specifically includes the following steps:

[0125] Weigh the raw materials according to the following proportions: 99.90 parts by weight of metallocene isotactic polypropylene; 0.1 parts by weight of degradation agent CR76.

[0126] Metallocene isotactic polypropylene and degradation agent CR76 were sequentially added to a high-speed mixer for premixing at a mixing temperature of 30°C, a rotation speed of 300 rpm, and a mixing time of 5 minutes to obtain a premix of metallocene polypropylene composite.

[0127] The premix was then extruded and granulated using a parallel co-rotating twin-screw extruder with a length-to-diameter ratio of 40:1 and a screw diameter of 30 mm. The extrusion compounding unit process conditions were as follows: feeder speed was set to 30 rpm; screw speed was set to 250 rpm; temperature of each section of the extruder was 160–290–160℃ (from the feed inlet to the die); vacuum degree was 750 mm Hg; an automatic screen changing mechanism was installed on the die head, and the filter screen was stacked in four layers in the order of 200 mesh / 300 mesh / 300 mesh / 200 mesh; cold water was used for strip cutting to obtain a metallocene polypropylene composite for spunbond nonwoven fabric with stable melt flow rate.

[0128] The above-mentioned metallocene polypropylene composite material for spunbond nonwoven fabric was used to prepare spunbond nonwoven fabric on a spunbond machine with a width of 100 mm. The processing technology for the spunbond nonwoven fabric was set as follows:

[0129] Extruder screw temperature 175-225℃

[0130] Extruder die temperature 230℃

[0131] Metering pump speed 10 rpm

[0132] Hot pressing temperature 130~135℃

[0133] The relevant properties of the obtained metallocene polypropylene composite material and spunbond nonwoven fabric were tested according to the above-mentioned standards and experimental methods, and the results are shown in Table 1.

[0134] Table 1 Performance Test Results

[0135]

[0136]

[0137] As can be seen from the data in the table above, the metallocene polypropylene composite material for soft antibacterial spunbond nonwoven fabric provided by the present invention uses metallocene isotactic polypropylene as the base resin, supplemented with random copolymer polypropylene to increase its softness, moderately controlled degradation is achieved by using hindered hydroxylamine ester degrading agent, and an appropriate amount of AC foaming agent is added. Combined with high-density polyethylene and other components, the obtained metallocene isotactic polypropylene composite material has excellent processing performance and better flexibility, and is suitable for special materials for spunbond nonwoven fabric.

[0138] Of course, the present invention may have other embodiments and variations. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and variations according to the present invention, but these corresponding changes and variations should all fall within the protection scope of the claims of the present invention.

Claims

1. A metallocene polypropylene composite material for soft, antibacterial spunbond nonwoven fabrics, characterized in that, By mass fraction, it includes the following raw materials: Metallocene isotactic polypropylene, 58.82–78.06 parts 10-15 parts of random copolymer polypropylene 0 to 9.0 parts of acrylic elastomer 10-20 parts of high-density polyethylene 0.10–0.18 parts of hindered hydroxylamine ester degradative agent AC foaming agent 0.1-0.4 parts 1.4–1.6 parts of nano zinc oxide 0.12–0.15 parts of hindered phenolic antioxidants Phosphate ester antioxidants: 0.12–0.15 parts.

2. The metallocene polypropylene composite material for soft antibacterial spunbond nonwoven fabric as described in claim 1, characterized in that, The melt flow rate of the metallocene isotactic polypropylene is 10-100 g / 10 min, and the isotacticity is above 95%.

3. The metallocene polypropylene composite material for soft antibacterial spunbond nonwoven fabric as described in claim 1, characterized in that, The melt flow rate of the random copolymer polypropylene is 10–50 g / 10 min.

4. The metallocene polypropylene composite material for soft antibacterial spunbond nonwoven fabric as described in claim 1, characterized in that, The melt flow rate of the propylene-based elastomer is 5–20 g / 10 min.

5. The metallocene polypropylene composite material for soft antibacterial spunbond nonwoven fabric as described in claim 1, characterized in that, The melt flow rate of the high-density polyethylene is 10–30 g / 10 min.

6. The metallocene polypropylene composite material for soft antibacterial spunbond nonwoven fabric as described in claim 1, characterized in that, The hindered hydroxylamine ester degrader has a melting temperature between 100 and 180°C and an apparent density of 0.45 to 0.55 g / cm³. 3 .

7. The metallocene polypropylene composite material for soft antibacterial spunbond nonwoven fabric as described in claim 1, characterized in that, The hindered phenolic antioxidant is antioxidant 1010; The phosphate ester antioxidant is antioxidant 168; The specific surface area of ​​the nano zinc oxide is 30±10m². 2 / g.

8. The use of the metallocene polypropylene composite material for soft antibacterial spunbond nonwoven fabric as described in any one of claims 1-7 in the preparation of filter materials, isolation materials, absorbent materials, or medical materials.

9. A soft antibacterial spunbond nonwoven fabric, made from the soft antibacterial spunbond nonwoven fabric of any one of claims 1-7 using a metallocene polypropylene composite material.

10. A method for preparing the soft antibacterial spunbond nonwoven fabric according to claim 9, characterized in that, Includes the following steps: Mixing: Metallocene isotactic polypropylene, random copolymer polypropylene, high-density polyethylene, hindered hydroxylamine ester degradative agent, nano zinc oxide, hindered phenolic antioxidant, and phosphate ester antioxidant are mixed sequentially to obtain a premix; or Metallocene isotactic polypropylene, random copolymer polypropylene, propylene-based elastomer, high-density polyethylene, hindered hydroxylamine ester degradative agent, nano zinc oxide, hindered phenolic antioxidant, and phosphate ester antioxidant are mixed sequentially to obtain a premix. Granulation: The premix is ​​extruded and granulated to obtain the complex; Foaming: The composite is mixed with AC foaming agent to obtain a mixture; Spunbond: The mixture is spunbonded to obtain the soft antibacterial spunbond nonwoven fabric.

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