High-stability hydrophilic polypropylene composite material as well as raw material composition, preparation method and melt-blown non-woven fabric thereof

Abstract

The invention provides a high-stability hydrophilic polypropylene composite material as well as a raw material composition, a preparation method and a melt-blown non-woven fabric thereof. The raw material composition is prepared from the following components in parts by weight: 92.2 to 96.5 parts of polypropylene, 1.5 to 3.9 parts of hydrophilic modifier, 1 to 3 parts of adsorbent, 0 to 0.5 part of molecular weight regulator, 0.1 to 0.3 part of antioxidant and 0.1 to 0.3 part of antioxidant aid, wherein the polypropylene is metallocene polypropylene, and the melt flow rate of the polypropylene is 300 to 1000g / 10min under the conditions of 230 DEG C and 2.16 kg. The melt-blown non-woven fabric prepared by blending and modifying polypropylene has high hydrophilicity, high water absorption and high hydrophilic long-term stability. Through an aging experiment at 60 DEG C, the hydrophilic effect is still good, and the effect of the hydrophilic component can be continuously maintained in the use process of the hydrophilic non-woven fabric.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer composite materials, and particularly relates to a highly stable hydrophilic polypropylene composite material, its raw material composition, preparation method and melt-blown non-woven fabric. Background Art

[0002] As one of the five general-purpose synthetic resins, polypropylene is a leading product in the field of polymer materials and is widely used in fields such as automobiles, furniture, building pipes, medical devices, packaging, fabrics and non-woven fabrics. Among them, the application of polypropylene melt-blown non-woven fabric in the fields of medical treatment and beauty shows an extremely high growth rate. In these application fields, polypropylene melt-blown non-woven fabric shows excellent use performance, low use cost and great economic value. However, polypropylene fibers have a non-polar structure and have limitations such as poor hydrophobicity or hygroscopicity, making polypropylene melt-blown non-woven fabric basically have no moisture absorption and water absorption capacity. Therefore, the polypropylene melt-blown non-woven fabric must be hydrophilically modified to meet the requirements of medical and health products for the covering material.

[0003] To meet the requirements of medical dressings and beauty masks for the hydrophilicity of polypropylene melt-blown non-woven fabric and improve the comfort and fit when it contacts human skin. In the prior art, first, there are surface modification methods such as polymer grafting method, cross-linking modification method, coating method, plasma treatment method, etc. However, these modification methods have the following defects: (1) They cannot be directly completed on the original processing equipment and need to add subsequent treatment processes, resulting in low production efficiency, high cost and complicated processes; (2) The surface modification is uneven, resulting in poor hydrophilicity of the modified melt-blown non-woven fabric; (3) The bonding between the melt-blown non-woven fabric and the modified molecules is poor, and it is easy to separate, fall off or wear, resulting in poor hydrophilic stability or even failure. In addition, raw material blending modification is widely used because of its simple preparation method and obvious modification effect. However, the added modification materials have problems such as poor compatibility with polypropylene, poor stability and easy escape, resulting in the polypropylene melt-blown non-woven fabric prepared still having problems such as weak hydrophilicity, poor water absorption ability, poor hydrophilic stability or even failure.

[0004] CN102675730A discloses a hydrophilic polypropylene mixture and its preparation method and application. The mixture contains homopolypropylene and a hydrophilic agent. The hydrophilic agent is selected from one or more of alkyl polyoxyethylene ether, alkenyl polyoxyethyl ether, alkylphenol polyoxyethylene ether and alkylamine polyoxyethylene ether, and has good emulsifying, dispersing, permeating and wetting effects, making the polypropylene mixture containing this component have better hydrophilic properties, so as to prepare a hydrophilic melt-blown non-woven fabric. The disadvantages of this technical solution compared with the present invention are that the compatibility of additives such as alkyl polyoxyethylene ether, alkenyl polyoxyethyl ether, alkylphenol polyoxyethylene ether and alkylamine polyoxyethylene ether with polypropylene is not good alone, and it is very easy to escape during the high-temperature melt-blown processing, resulting in poor hydrophilic stability and odor of the melt-blown non-woven fabric.

[0005] Therefore, in view of the problems existing in the current blending modification, we not only need to select a hydrophilic modification material with better compatibility with polypropylene, better hydrophilicity, and more persistent hydrophilic effect, but also need to introduce necessary stabilizing aids to effectively adsorb the hydrophilic components, so as to improve the compatibility and stability between the hydrophilic modification material and polypropylene, and then prepare a polypropylene meltblown non-woven fabric with excellent and stable hydrophilic properties. Summary of the Invention

[0006] To solve the above technical problems, the purpose of the present invention is to provide a highly stable hydrophilic polypropylene composite material, its raw material composition, preparation method, and meltblown non-woven fabric. By adding a hydrophilic modifier and an adsorbent, this method can prepare a polypropylene composite material with high hydrophilicity, high water absorption, and high long-term hydrophilic stability, and is applied to the preparation of meltblown non-woven fabrics.

[0007] To achieve the above purpose, the present invention provides a raw material composition for a highly stable hydrophilic polypropylene composite material, wherein the raw material composition includes: 92.2 - 96.5 parts of polypropylene, 1.5 - 3.9 parts of a hydrophilic modifier, 1 - 3 parts of an adsorbent, 0 - 0.5 parts of a molecular weight regulator, 0.1 - 0.3 parts of an antioxidant, and 0.1 - 0.3 parts of a co-antioxidant; wherein, the polypropylene is metallocene polypropylene, and its melt flow rate at 230°C and 2.16 kg is 300 - 1000 g / 10 min. Metallocene polypropylene has the advantages of narrow molecular weight distribution, few ultra-high molecular weight components, and sensitivity to molecular weight regulators. After controlled degradation, it is more suitable for the production of polypropylene meltblown cloth. The obtained fibers are uniform, finer, and have a soft hand. Moreover, due to the finer fibers, it has a larger specific surface area, which is beneficial to enhancing its hydrophilic effect.

[0008] According to a specific embodiment of the present invention, preferably, the hydrophilic modifier includes one or a combination of two or more of a short-term hydrophilic component, a medium-term functional hydrophilic component, and a long-term hydrophilic component. Through the combination of the above hydrophilic components in the present invention, the prepared material can obtain good hydrophilicity in the short term (after offline), medium term (3 - 15 days), and long term (15 - 90 days), and has highly stable hydrophilic properties. By compounding the short-term, medium-term, and long-term hydrophilic components, the meltblown non-woven fabric prepared by blending and modifying polypropylene has high hydrophilicity, high water absorption, and high long-term hydrophilic stability.

[0009] According to a specific embodiment of the present invention, preferably, the short-term hydrophilic component is erucamide and / or isotridecanol-ethylene oxide copolymer; the purity of erucamide and isotridecanol-ethylene oxide copolymer is more than 99% by mass percentage.

[0010] In some specific embodiments, preferably, the hydroxyl value of the isotridecyl alcohol-ethylene oxide copolymer is 270-290 mg KOH / g.

[0011] According to the specific embodiments of the present invention, preferably, the medium-term efficacy hydrophilic component is vinyl bisstearamide and / or bis(β-hydroxyethyl)stearylamine; the purity of vinyl bisstearamide and bis(β-hydroxyethyl)stearylamine is more than 99% by mass percentage.

[0012] According to the specific embodiments of the present invention, preferably, the long-acting hydrophilic component is ethylene-vinyl alcohol copolymer.

[0013] In some specific embodiments, preferably, the mass percentage of ethylene in the ethylene-vinyl alcohol copolymer is 20-40%.

[0014] In some specific embodiments, preferably, the melt flow rate of the ethylene-vinyl alcohol copolymer under the conditions of 230°C and 2.16 kg is 10-25 g / 10 min.

[0015] According to the specific embodiments of the present invention, preferably, the molecular weight regulator is 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane; the purity of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane is more than 99% by mass percentage. 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane is used to adjust the rheological properties of the polypropylene composite material and improve the meltblowing processing performance, in order to obtain finer fibers, thereby increasing the fiber specific surface area and enhancing the water absorbency and softness of the meltblown nonwoven fabric.

[0016] According to the specific embodiments of the present invention, preferably, the adsorbent is silica white, more preferably fumed silica; the purity of the silica white is more than 99% by mass percentage. Silica white has a porous structure, a very large specific surface area, and a certain proportion of hydrophilic groups on its surface, which is beneficial to adsorb polar components and control the migration rate of hydrophilic components. Fumed silica has a strong adsorption function, can effectively adsorb hydrophilic components, achieve a long-term slow-release function, and improve the hydrophilic stability of the meltblown nonwoven fabric.

[0017] According to the specific embodiments of the present invention, preferably, the antioxidant is pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (Irganox 1010, BASF); the purity of the antioxidant is more than 99% by mass percentage.

[0018] According to the specific embodiments of the present invention, preferably, the co-antioxidant is tris(2,4-di-tert-butylphenyl) phosphite (Irganox 168, BASF); the purity of the co-antioxidant is more than 99% by mass percentage.

[0019] According to a specific embodiment of the present invention, preferably, the raw material composition comprises: 92.2 - 96.5 parts of polypropylene, 0.1 - 0.8 parts of erucamide, 0.1 - 0.5 parts of ethylene bisstearamide, 0.2 - 0.8 parts of isotridecyl alcohol - ethylene oxide copolymer, 0.3 - 0.6 parts of bis(β - hydroxyethyl) stearylamine, 1 - 3 parts of silica, 0 - 2 parts of ethylene - vinyl alcohol copolymer, 0 - 0.5 parts of 2,5 - dimethyl - 2,5 - bis(tert - butylperoxy)hexane, 0.1 - 0.3 parts of antioxidant, and 0.1 - 0.3 parts of co - antioxidant.

[0020] The present invention also provides a highly stable hydrophilic polypropylene composite material, which is prepared from the above - mentioned raw material composition.

[0021] According to a specific embodiment of the present invention, preferably, the surface contact angle of the highly stable hydrophilic polypropylene composite material is 53° - 66°.

[0022] According to a specific embodiment of the present invention, preferably, the water absorption capacity of the highly stable hydrophilic polypropylene composite material is 841% - 979%, and the water absorption time is 16.7 - 19.7 s.

[0023] The present invention also provides a preparation method of the above - mentioned highly stable hydrophilic polypropylene composite material. Among them, the preparation method comprises: premixing polypropylene, hydrophilic modifier, adsorbent, molecular weight regulator, antioxidant, and co - antioxidant, and then melt - extruding and pelletizing to obtain a polypropylene composite material.

[0024] According to a specific embodiment of the present invention, preferably, the premixing is carried out in a high - speed mixer, the mixing temperature is 20 - 30°C, the rotation speed is 200 - 300 revolutions per minute, and the mixing time is 3 - 8 minutes.

[0025] According to a specific embodiment of the present invention, preferably, the melt - extrusion pelletizing is carried out in a twin - screw extruder, the screw rotation speed is 100 - 300 revolutions per minute, the feeder rotation speed is 10 - 50 revolutions per minute, and the temperature of each section of the extruder is 160 - 200°C.

[0026] In the above preparation method, preferably, the preparation method specifically includes the following steps: pre-mixing polypropylene, erucamide, vinyl bisstearamide, isotridecanol-ethylene oxide copolymer, bis(β-hydroxyethyl) stearylamine, silica, ethylene-vinyl alcohol copolymer, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, antioxidant, and co-antioxidant in a high-speed mixer at a mixing temperature of 20-30°C, a rotation speed of 200-300 revolutions per minute, and a mixing time of 3-8 minutes; then adding the mixture into a twin-screw extruder for melt extrusion granulation, with a screw rotation speed of 100-300 revolutions per minute, a feeder rotation speed of 10-50 revolutions per minute, and the temperature of each section of the extruder being 160-200°C, to obtain a polypropylene composite material.

[0027] The present invention also provides a meltblown nonwoven fabric, which is prepared from the above high-stability hydrophilic polypropylene composite material.

[0028] According to a specific embodiment of the present invention, preferably, the grammage of the meltblown nonwoven fabric is 48-52 g / m 2 .

[0029] According to a specific embodiment of the present invention, preferably, the preparation method of the meltblown nonwoven fabric includes: after drying the pellets of the polypropylene composite material, melt-spinning is carried out at 200-250°C using a meltblown spinning machine to obtain a hydrophilic meltblown nonwoven fabric.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0031] (1) The meltblown nonwoven fabric prepared by blending and modifying polypropylene in the present invention has high hydrophilicity, high water absorbency, and high long-term hydrophilic stability. After the aging experiment at 60°C, the hydrophilic effect is still very good, and the efficacy of the hydrophilic components can be continuously maintained during the use of the hydrophilic nonwoven fabric.

[0032] (2) The additives used in the polypropylene composite material of the present invention meet the technical requirements of medical supplies, the preparation method is simple, and the excellent processing performance is retained, and it can be smoothly processed on the original processing equipment. Specific Embodiments

[0033] In order to have a clearer understanding of the technical features, objectives, and beneficial effects of the present invention, the technical solutions of the present invention are described in detail below, but it should not be construed as a limitation on the implementable scope of the present invention.

[0034] In the examples and comparative examples of the present invention, the polypropylene resin is the metallocene polypropylene Achieve Advanced PP6945G1 from ExxonMobil, and its melt flow rate (230°C, 2.16 kg) is 925 g / 10 min;

[0035] The hydrophilic modifiers include: commercially available erucamide with a purity above 99%; vinyl bisstearamide is EBS-SF from KLK with a purity above 99%; isotridecanol-ethylene oxide copolymer is MARLIPAL O13 from Sasol with a hydroxyl value of 270 - 290 mg KOH / g and a purity above 99%; bis(β-hydroxyethyl) stearylamine is Armostat 1800 from Acheson with a purity above 99%; ethylene-vinyl alcohol copolymer is C109A from Kuraray with an ethylene mass percentage of 35.0% and a melt flow rate (at 230 °C, 2.16 kg) of about 21 g / 10 min;

[0036] The white carbon black is M-5 from Cabot with a purity above 99%;

[0037] 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane is Enox 101 from Jiangsu Qiangsheng Functional Chemical Co., Ltd. with a purity above 99%;

[0038] The antioxidant is pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (Irganox 1010) from BASF with a purity above 99%;

[0039] The co-antioxidant is tris(2,4-di-tert-butylphenyl) phosphite (Irganox 168) from BASF with a purity above 99%.

[0040] The evaluation principle of the hydrophilic property of the above hydrophilic modifiers is as follows: (a) like dissolves like; (b) a large difference in solubility parameters is conducive to migration; (c) a small molecular weight is conducive to migration, and the hydrophilic components with a molecular weight exceeding 5000 mainly maintain surface hydrophilicity and are difficult to migrate.

[0041] Among them, the solubility parameter is the data obtained by molecular dynamics calculation;

[0042] Migration rate: A score is given based on the comparison of molecular weights;

[0043] Measured migration score: After the product is made for 24 hours, the product is washed with an ethanol / benzene mixed solvent, and the amount of the migrated substance is tested by chromatography to give a comparative score;

[0044] Compatibility: An empirical judgment comparative score is given based on the above solubility parameter and the measured value of the migration rate.

[0045] The relevant evaluation data are shown in Table 1:

[0046] Table 1 Basis for evaluating the hydrophilic property of hydrophilic modifiers

[0047]

[0048] Example 1

[0049] This example provides a method for preparing a highly stable hydrophilic polypropylene composite material and a melt-blown non-woven fabric, which includes the following steps:

[0050] Weigh each raw material according to the following ratio: 96.1 parts by mass of polypropylene, 0.3 parts by mass of erucamide, 0.1 parts by mass of vinyl bisstearamide, 0.5 parts by mass of isotridecanol-ethylene oxide copolymer, 0.6 parts by mass of bis(β-hydroxyethyl)stearylamine, 2.0 parts by mass of silica, 0.2 parts by mass of antioxidant Irganox 1010, and 0.2 parts by mass of co-antioxidant Irganox 168.

[0051] Add the above raw materials to a high-speed mixer in sequence for premixing. The mixing temperature is 20°C, the rotation speed is 300 revolutions per minute, and the mixing time is 3 minutes.

[0052] Then, add the premixed material from the feeder to a twin-screw extruder for melt extrusion granulation. The process conditions are set as follows: the screw rotation speed is 200 revolutions per minute, the feeder rotation speed is 30 revolutions per minute, and the temperature of each section of the extruder is 160 - 200°C, thus obtaining polypropylene composite material pellets.

[0053] Use the dried polypropylene composite material pellets to prepare hydrophilic melt-blown non-woven fabric with a basis weight of about 50 g / m 2 by melt blowing method at 200 - 250°C. Test various properties of the obtained hydrophilic melt-blown non-woven fabric, and the test results are shown in Table 2.

[0054] Example 2

[0055] This example provides a method for preparing a highly stable hydrophilic polypropylene composite material and a melt-blown non-woven fabric, which includes the following steps:

[0056] Weigh each raw material according to the following ratio: 93.8 parts by mass of polypropylene, 0.1 parts by mass of erucamide, 0.3 parts by mass of vinyl bisstearamide, 0.8 parts by mass of isotridecanol-ethylene oxide copolymer, 0.3 parts by mass of bis(β-hydroxyethyl)stearylamine, 3.0 parts by mass of silica, 1 part by mass of ethylene-vinyl alcohol copolymer, 0.3 parts by mass of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 0.3 parts by mass of antioxidant Irganox 1010, and 0.1 parts by mass of co-antioxidant Irganox 168.

[0057] Add the above raw materials to a high-speed mixer in sequence for premixing. The mixing temperature is 20°C, the rotation speed is 300 revolutions per minute, and the mixing time is 3 minutes.

[0058] Then, the pre-mixed materials are added from the feeder into the twin-screw extruder for melt extrusion granulation. The process conditions are set as follows: the screw speed is 200 revolutions per minute, the feeder speed is 30 revolutions per minute, and the temperatures of each section of the extruder are 160 - 200 °C, thus obtaining polypropylene composite pellets.

[0059] The dried polypropylene composite pellets are used to prepare hydrophilic melt-blown non-woven fabric with a basis weight of about 50 g / m 2 by a melt-blown spinning machine at 200 - 250 °C. The various properties of the obtained hydrophilic melt-blown non-woven fabric are tested, and the test results are shown in Table 2.

[0060] Example 3

[0061] This example provides a preparation method of a highly stable hydrophilic polypropylene composite material and melt-blown non-woven fabric, which includes the following steps:

[0062] Weigh each raw material according to the following ratio: 92.2 parts by mass of polypropylene, 0.5 part by mass of erucamide, 0.4 part by mass of vinyl bisstearamide, 0.6 part by mass of isotridecyl alcohol-ethylene oxide copolymer, 0.4 part by mass of bis(β-hydroxyethyl)stearylamine, 3.0 parts by mass of silica, 2.0 parts by mass of ethylene-vinyl alcohol copolymer, 0.5 part by mass of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 0.1 part by mass of antioxidant Irganox 1010, and 0.3 part by mass of co-antioxidant Irganox 168.

[0063] Add the above raw materials into a high-speed mixer in sequence for pre-mixing. The mixing temperature is 20 °C, the rotation speed is 300 revolutions per minute, and the mixing time is 3 minutes.

[0064] Then, the pre-mixed materials are added from the feeder into the twin-screw extruder for melt extrusion granulation. The process conditions are set as follows: the screw speed is 200 revolutions per minute, the feeder speed is 30 revolutions per minute, and the temperatures of each section of the extruder are 160 - 200 °C, thus obtaining polypropylene composite pellets.

[0065] The dried polypropylene composite pellets are used to prepare hydrophilic melt-blown non-woven fabric with a basis weight of about 50 g / m 2 by a melt-blown spinning machine at 200 - 250 °C. The various properties of the obtained hydrophilic melt-blown non-woven fabric are tested, and the test results are shown in Table 2.

[0066] Example 4

[0067] This example provides a preparation method of a highly stable hydrophilic polypropylene composite material and melt-blown non-woven fabric, which includes the following steps:

[0068] Weigh each raw material according to the following ratio: 95.5 parts by mass of polypropylene, 0.6 parts by mass of erucamide, 0.5 parts by mass of vinyl bisstearamide, 0.2 parts by mass of isotridecyl alcohol-ethylene oxide copolymer, 0.5 parts by mass of bis(β-hydroxyethyl) stearylamine, 2.0 parts by mass of silica, 0.3 parts by mass of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 0.2 parts by mass of antioxidant Irganox 1010, and 0.2 parts by mass of co-antioxidant Irganox 168.

[0069] Add the above raw materials to a high-speed mixer in sequence for premixing. The mixing temperature is 20°C, the rotation speed is 300 revolutions per minute, and the mixing time is 3 minutes.

[0070] Then, add the premixed material from the feeder to a twin-screw extruder for melt extrusion granulation. The process conditions are set as follows: the screw rotation speed is 200 revolutions per minute, the feeder rotation speed is 30 revolutions per minute, and the temperature of each section of the extruder is 160 - 200°C, thus obtaining polypropylene composite pellets.

[0071] Use the melt spinning machine to prepare hydrophilic melt-blown non-woven fabric with a basis weight of about 50 g / m² from the dried polypropylene composite pellets at 200 - 250°C. Test various properties of the obtained hydrophilic melt-blown non-woven fabric, and the test results are shown in Table 2. 2 around

[0072] Example 5

[0073] This example provides a preparation method of a highly stable hydrophilic polypropylene composite and melt-blown non-woven fabric, which includes the following steps:

[0074] Weigh each raw material according to the following ratio: 96.5 parts by mass of polypropylene, 0.8 parts by mass of erucamide, 0.2 parts by mass of vinyl bisstearamide, 0.4 parts by mass of isotridecyl alcohol-ethylene oxide copolymer, 0.3 parts by mass of bis(β-hydroxyethyl) stearylamine, 1.0 parts by mass of silica, 0.4 parts by mass of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 0.3 parts by mass of antioxidant Irganox 1010, and 0.1 parts by mass of co-antioxidant Irganox 168.

[0075] Add the above raw materials to a high-speed mixer in sequence for premixing. The mixing temperature is 20°C, the rotation speed is 300 revolutions per minute, and the mixing time is 3 minutes.

[0076] Then, add the premixed material from the feeder to a twin-screw extruder for melt extrusion granulation. The process conditions are set as follows: the screw rotation speed is 200 revolutions per minute, the feeder rotation speed is 30 revolutions per minute, and the temperature of each section of the extruder is 160 - 200°C, thus obtaining polypropylene composite pellets.

[0077] The dried polypropylene composite pellets are used to prepare a hydrophilic melt-blown non-woven fabric with a basis weight of about 50 g / m² by a melt-blown spinning machine at 200 - 250 °C. 2 The properties of the obtained hydrophilic melt-blown non-woven fabric are tested, and the test results are shown in Table 2.

[0078] Comparative Example 1

[0079] This comparative example provides a method for preparing a polypropylene composite material and a melt-blown non-woven fabric, which includes the following steps:

[0080] Weigh each raw material according to the following ratio: 99.6 parts by mass of polypropylene, 0.2 parts by mass of antioxidant Irganox 1010, and 0.2 parts by mass of co-antioxidant Irganox 168. Add the above raw materials to a high-speed mixer in sequence for premixing. The mixing temperature is 20 °C, the rotation speed is 300 revolutions per minute, and the mixing time is 3 minutes. Then, add the premixed material from the feeder to a twin-screw extruder for melt extrusion granulation. The process conditions are set as follows: the screw rotation speed is 200 revolutions per minute, the feeder rotation speed is 30 revolutions per minute, and the temperature of each section of the extruder is 160 - 200 °C, thus obtaining polypropylene composite pellets.

[0081] The dried polypropylene composite pellets are used to prepare a hydrophilic melt-blown non-woven fabric with a basis weight of about 50 g / m² by a melt-blown spinning machine at 200 - 250 °C. 2 The properties of the obtained hydrophilic melt-blown non-woven fabric are tested, and the test results are shown in Table 2.

[0082] Comparative Example 2

[0083] This comparative example provides a method for preparing a polypropylene composite material and a melt-blown non-woven fabric, which includes the following steps:

[0084] Weigh each raw material according to the following ratio: 99.3 parts by mass of polypropylene, 0.3 parts by mass of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 0.2 parts by mass of antioxidant Irganox 1010, and 0.2 parts by mass of co-antioxidant Irganox 168. Add the above raw materials to a high-speed mixer in sequence for premixing. The mixing temperature is 20 °C, the rotation speed is 300 revolutions per minute, and the mixing time is 3 minutes. Then, add the premixed material from the feeder to a twin-screw extruder for melt extrusion granulation. The process conditions are set as follows: the screw rotation speed is 200 revolutions per minute, the feeder rotation speed is 30 revolutions per minute, and the temperature of each section of the extruder is 160 - 200 °C, thus obtaining polypropylene composite pellets.

[0085] The dried polypropylene composite pellets are used to prepare a hydrophilic melt-blown non-woven fabric with a basis weight of about 50 g / m² by a melt-blown spinning machine at 200 - 250 °C. 2Hydrophilic meltblown non-woven fabric around. Test the performance of the obtained hydrophilic meltblown non-woven fabric, and the test results are shown in Table 2.

[0086] Next, the specific experimental data will be analyzed and compared for the properties of polypropylene materials and meltblown non-woven fabrics. The experimental results are shown in Table 2:

[0087] Table 2 Comparison of the raw material ratios and the properties of meltblown non-woven fabrics of the polypropylene composites obtained in the examples and comparative examples

[0088]

[0089]

[0090] It can be seen from the comparison between the examples and the comparative examples in Table 2 that the meltblown non-woven fabric prepared from polypropylene modified by the compounded hydrophilic components has a smaller surface contact angle and stronger water absorption ability. After the aging experiment at 60 °C (placed for one day), it can still maintain a strong water absorption ability and a short water absorption time. In addition, the added fumed silica has a strong adsorption function, which can effectively adsorb the hydrophilic components, realize the long-term slow-release function, and improve the hydrophilic stability of the meltblown non-woven fabric. 2,5-Dimethyl-2,5-bis(tert-butylperoxy)hexane is used to adjust the rheological properties of the polypropylene composite and improve the meltblown processing performance, and finer fibers can be obtained, thereby increasing the fiber specific surface area and enhancing the water absorption and softness of the meltblown non-woven fabric.

Claims

1. A raw material composition for a highly stable hydrophilic polypropylene composite material, wherein, the raw material composition comprises: 92.2 - 96.5 parts of polypropylene, 1.5 - 3.9 parts of hydrophilic modifier, 1 - 3 parts of adsorbent, 0 - 0.5 parts of molecular weight regulator, 0.1 - 0.3 parts of antioxidant, and 0.1 - 0.3 parts of co - antioxidant; wherein, the polypropylene is metallocene polypropylene, and the melt flow rate under the conditions of 230 °C and 2.16 kg is 300 - 1000 g / 10 min.

2. The raw material composition according to claim 1, wherein, the hydrophilic modifier comprises one or a combination of two or more of a short - acting hydrophilic component, a medium - term efficacy hydrophilic component, and a long - term hydrophilic component.

3. The raw material composition according to claim 2, wherein, the short - acting hydrophilic component is erucic acid amide and / or isotridecanol - ethylene oxide copolymer; preferably, the hydroxyl value of the isotridecanol - ethylene oxide copolymer is 270 - 290 mg KOH / g.

4. The raw material composition according to claim 2, wherein, the medium - term efficacy hydrophilic component is vinyl bisstearamide and / or bis(β - hydroxyethyl) stearylamine.

5. The raw material composition according to claim 2, wherein, the long - term hydrophilic component is ethylene - vinyl alcohol copolymer; preferably, the mass percentage content of ethylene in the ethylene - vinyl alcohol copolymer is 20 - 40%; the melt flow rate of the ethylene - vinyl alcohol copolymer under the conditions of 230 °C and 2.16 kg is 10 - 25 g / 10 min.

6. The raw material composition according to claim 1, wherein, the molecular weight regulator is 2,5 - dimethyl - 2,5 - bis(tert - butylperoxy) hexane.

7. The raw material composition according to claim 1, wherein, the adsorbent is silica white, preferably fumed silica white.

8. The raw material composition according to any one of claims 1 - 7, wherein, the raw material composition comprises: 92.2 - 96.5 parts of polypropylene, 0.1 - 0.8 parts of erucic acid amide, 0.1 - 0.5 parts of vinyl bisstearamide, 0.2 - 0.8 parts of isotridecanol - ethylene oxide copolymer, 0.3 - 0.6 parts of bis(β - hydroxyethyl) stearylamine, 1 - 3 parts of silica white, 0 - 2 parts of ethylene - vinyl alcohol copolymer, 0 - 0.5 parts of 2,5 - dimethyl - 2,5 - bis(tert - butylperoxy) hexane, 0.1 - 0.3 parts of antioxidant, and 0.1 - 0.3 parts of co - antioxidant.

9. A highly stable hydrophilic polypropylene composite material, which is prepared from the raw material composition according to any one of claims 1 - 8; preferably, the surface contact angle of the highly stable hydrophilic polypropylene composite material is 53° - 66°; preferably, the water absorption capacity of the highly stable hydrophilic polypropylene composite material is 841% - 979%, and the water absorption time is 16.7 - 19.7 s.

10. The preparation method of the highly stable hydrophilic polypropylene composite material according to claim 9, wherein, the preparation method comprises: Pre-mix polypropylene, hydrophilic modifier, adsorbent, molecular weight regulator, antioxidant, and co-antioxidant, and then melt extrude and pelletize to obtain a polypropylene composite material; Preferably, the pre-mixing is carried out in a high-speed mixer at a mixing temperature of 20 - 30 °C, a rotation speed of 200 - 300 revolutions per minute, and a mixing time of 3 - 8 minutes; Preferably, the melt extrusion and pelletization are carried out in a twin-screw extruder with a screw rotation speed of 100 - 300 revolutions per minute, a feeder rotation speed of 10 - 50 revolutions per minute, and the temperature of each section of the extruder being 160 - 200 °C.

11. A meltblown non-woven fabric, which is prepared from the highly stable hydrophilic polypropylene composite material according to claim 9 or 10; Preferably, the basis weight of the meltblown nonwoven fabric is 48-52 g / m 2 ; Preferably, the preparation method of the meltblown non-woven fabric comprises: After drying the pellets of the polypropylene composite material, a hydrophilic meltblown non-woven fabric is prepared by a meltblown spinning machine at 200 - 250 °C.

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