Novel super-hydrophobic CPP film and preparation method thereof

Abstract

The invention discloses a novel super-hydrophobic CPP film and a preparation method thereof, and relates to the technical field of super-hydrophobic films. Mesoporous carbon is firstly dispersed in a perfluorooctyl sorbitol solution, perfluorooctyl sorbitol enters pore channels of the mesoporous carbon and is attached to the surface of the mesoporous carbon through ultrasonic infiltration treatment, a microscopic rough surface is constructed, air can be captured, the contact area of water and a CPP film is reduced, the contact angle of the water is remarkably increased, and the super-hydrophobic performance is achieved; then dropwise adding isocyanate 1-trimethoxysilyl methyl ester into the dispersion system, then adding a proper amount of deionized water into the system and dispersing the system in polypropylene, so that isocyanate 1-trimethoxysilyl methyl ester is hydrolyzed to generate silanol groups, and the silanol groups can be subjected to condensation reaction; the mesoporous carbon, the perfluorooctyl sorbitol and the polypropylene are connected together, so that the stability is enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of superhydrophobic thin films, and specifically to a novel superhydrophobic CPP film and a preparation method thereof. Background Art

[0002] Cast Polypropylene Film (CPP film) is produced by a cast extrusion process. CPP films have the characteristics of good transparency, high gloss, good stiffness, good moisture barrier property, excellent heat resistance, and easy heat sealing, and are widely used in packaging fields such as food, medicine, household paper, clothing, daily necessities, and industry.

[0003] CPP film is one of the key components of aluminum-plastic film, especially playing an important role in the encapsulation of soft-packaged lithium batteries. CPP film is usually located in the innermost layer of the aluminum-plastic film and is in direct contact with the battery core. This requires that the CPP film not only has excellent deep-drawing resistance, heat-sealing, and electrolyte resistance properties, but also needs to have hydrophobic properties. At present, there is an urgent need to develop a superhydrophobic CPP film to block water vapor from entering the battery core to protect the safety of the battery. Summary of the Invention

[0004] The purpose of the present invention is to provide a novel superhydrophobic CPP film and a preparation method thereof to solve the problems existing in the prior art.

[0005] To solve the above technical problems, the present invention provides the following technical solution: A novel superhydrophobic CPP film, comprising polypropylene, mesoporous carbon, perfluorooctyl sorbitol solution, isocyanato-1-trimethoxysilane, deionized water, and acetic acid, and comprising the following preparation steps: (1) Mix the mesoporous carbon with the perfluorooctyl sorbitol solution after removing moisture and impurities according to a mass ratio of 1:3-5 and perform ultrasonic treatment at 20-40°C, with a power of 200-400W, a frequency of 20-40kHz, and a time of 60-90 minutes; (2) Add isocyanato-1-trimethoxysilane to the dispersion system obtained in step (1) at a rate of 2-3 drops per minute. The mass ratio of isocyanato-1-trimethoxysilane to mesoporous carbon is 0.2-0.5:1. After dropping, charge nitrogen for 10-15 minutes and stir and react at 60-70°C at 300-400r / min for 2-4 hours; Subsequently, add deionized water according to a mass ratio of deionized water to isocyanato-1-trimethoxysilane of 2-3:1, and add a small amount of acetic acid of 0.1-0.3% of the mass of isocyanato-1-trimethoxysilane, and stir at a speed of 200-300r / min at room temperature for 1-2 hours to obtain a dispersion solution; (3) Mix the dispersion solution obtained in step (2) and polypropylene at a mass ratio of 1:12 - 17, transfer it to a twin-screw extruder, melt extrude and granulate to obtain mixed material pellets; place the mixed material pellets in an extrusion casting machine to cast a film with a thickness of 25 - 30 μm, and then perform double-sided corona treatment at a voltage of 12 kV, a frequency of 20 kHz, and a treatment speed of 35 m / min, and wind it up to obtain a novel superhydrophobic CPP film.

[0006] Further, the novel superhydrophobic CPP film further comprises dibutyltin dilaurate.

[0007] Further, the novel superhydrophobic CPP film further comprises maleic anhydride grafted polypropylene, and the weight average molecular weight of maleic anhydride grafted polypropylene is 30000.

[0008] Further, the polypropylene is polypropylene chips with a melting point of 169 °C produced by Sinopec Jinan Branch.

[0009] Further, the perfluorooctyl sorbitol solution is obtained by mixing perfluorooctyl sorbitol and absolute ethanol.

[0010] Further, in step (1), the preparation method of the perfluorooctyl sorbitol solution comprises: mixing perfluorooctyl sorbitol and absolute ethanol at a mass ratio of 1:3 - 5, and stirring at a speed of 300 - 500 r / min at 20 - 30 °C for 30 - 60 minutes.

[0011] Further, in step (1), the process of obtaining mesoporous carbon with water and impurities removed comprises: placing mesoporous carbon with a particle size of 10 - 50 nm and a specific surface area ≥ 500 m² / g in a muffle furnace, calcining at 300 - 400 °C for 2 - 3 hours to remove water and surface impurities, then cooling to room temperature and grinding it into fine powder with a mortar, and passing through a 200-mesh sieve.

[0012] Further, in step (1), the mass ratio of mesoporous carbon to perfluorooctyl sorbitol solution is preferably 1:4.

[0013] Further, in step (2), the mass ratio of isocyanic acid 1-trimethoxysilylmethyl ester to mesoporous carbon is 0.3:1.

[0014] Compared with the prior art, the beneficial effects achieved by the present invention are: In the present invention, mesoporous carbon is dispersed in a perfluorooctyl sorbitol solution. Through ultrasonic infiltration treatment, perfluorooctyl sorbitol enters the pores of the mesoporous carbon and adheres to its surface, constructing a microscopic rough surface that can capture air, reducing the contact area between water and the CPP film, significantly increasing the water contact angle, and achieving superhydrophobic performance. Then, isocyanato-1-trimethoxysilane is dropped into the above dispersion system. Since the isocyanate group in isocyanato-1-trimethoxysilane undergoes an addition reaction with the surface active groups (such as -OH, -NH2, etc.) of mesoporous carbon and perfluorooctyl sorbitol, isocyanato-1-trimethoxysilane is grafted onto the surfaces of mesoporous carbon and perfluorooctyl sorbitol. Subsequently, an appropriate amount of deionized water is added to the above system and dispersed in polypropylene, causing isocyanato-1-trimethoxysilane to hydrolyze to form silanol groups. The silanol groups can undergo a condensation reaction to connect mesoporous carbon, perfluorooctyl sorbitol, and polypropylene together, enhancing the stability and ensuring the durability of the hydrophobic performance. Detailed implementation mode

[0015] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0016] The method provided by the present invention will be described in detail through the following embodiments for a clearer illustration: Embodiment 1 (1) Mesoporous carbon with a particle size of 30 nm and a specific surface area of 800 m² / g is placed in a muffle furnace and calcined at 350°C for 2 hours to remove moisture and surface impurities. After cooling to room temperature, it is ground into a fine powder with a mortar and passed through a 200-mesh sieve to obtain mesoporous carbon with moisture and impurities removed; (2) Perfluorooctyl sorbitol and absolute ethanol are mixed at a mass ratio of 1:4 and stirred at a speed of 300 r / min at 30°C for 60 minutes to obtain a perfluorooctyl sorbitol solution; (3) The mesoporous carbon obtained in step (1) and the perfluorooctyl sorbitol solution are mixed at a mass ratio of 1:3 and ultrasonically treated at 30°C with a power of 400 W, a frequency of 40 kHz, and a time of 60 minutes; (4) Add isocyanato-1-trimethoxysilane methyl ester to the dispersion system obtained in step (3) at a rate of 2 drops per minute, and simultaneously add dibutyltin dilaurate at 0.3% of the mass of isocyanato-1-trimethoxysilane methyl ester. The mass ratio of isocyanato-1-trimethoxysilane methyl ester to mesoporous carbon is 0.2:1. After the dropping is completed, fill with nitrogen for 15 minutes, and stir and react at 70 °C at 300 r / min for 3 hours. Subsequently, add deionized water at a mass ratio of deionized water to isocyanato-1-trimethoxysilane methyl ester of 3:1, and add acetic acid at 0.1% of the mass of isocyanato-1-trimethoxysilane methyl ester, and stir at 300 r / min at room temperature for 2 hours to obtain a dispersion solution. (5) Mix the dispersion solution obtained in step (4), polypropylene, and maleic anhydride grafted polypropylene in a mass ratio of 1:12:2, transfer them to a twin-screw extruder, melt and extrude to granulate to obtain mixed granules. Place the mixed granules in an extrusion casting machine to cast a film with a thickness of 30 μm, and then perform double-sided corona treatment at a voltage of 12 kV, a frequency of 20 kHz, and a treatment speed of 35 m / min, and wind up to obtain a novel superhydrophobic CPP film.

[0017] Example 2 (1) Place mesoporous carbon with a particle size of 30 nm and a specific surface area of 800 m² / g in a muffle furnace, calcine at 350 °C for 2 hours to remove moisture and surface impurities, and then cool to room temperature, grind it into fine powder with a mortar, and pass through a 200-mesh sieve to obtain mesoporous carbon with moisture and impurities removed. (2) Mix perfluorooctyl sorbitol and absolute ethanol in a mass ratio of 1:4, and stir at 300 r / min at 30 °C for 60 minutes to obtain a perfluorooctyl sorbitol solution. (3) Mix the mesoporous carbon obtained in step (1) and the perfluorooctyl sorbitol solution in a mass ratio of 1:4 and perform ultrasonic treatment at 30 °C, with a power of 400 W, a frequency of 40 kHz, and a time of 60 minutes. (4) Add isocyanato-1-trimethoxysilane methyl ester to the dispersion system obtained in step (3) at a rate of 2 drops per minute, and simultaneously add dibutyltin dilaurate at 0.3% of the mass of isocyanato-1-trimethoxysilane methyl ester. The mass ratio of isocyanato-1-trimethoxysilane methyl ester to mesoporous carbon is 0.3:1. After the dropping is completed, fill with nitrogen for 15 minutes, and stir and react at 70 °C at 300 r / min for 3 hours. Subsequently, add deionized water at a mass ratio of deionized water to isocyanato-1-trimethoxysilane methyl ester of 3:1, and add a small amount of acetic acid at 0.1% of the mass of isocyanato-1-trimethoxysilane methyl ester, and stir at 300 r / min at room temperature for 2 hours to obtain a dispersion solution. (5) Mix the dispersion solution obtained in step (4), polypropylene, and maleic anhydride grafted polypropylene in a mass ratio of 1:14:2, transfer it to a twin-screw extruder, melt-extrude and pelletize to obtain mixed pellets; place the mixed pellets in an extrusion casting machine to cast a film with a thickness of 30 μm, and then perform double-sided corona treatment at a voltage of 12 kV, a frequency of 20 kHz, and a treatment speed of 35 m / min, and wind up to obtain a novel superhydrophobic CPP film.

[0018] Example 3 (1) Place mesoporous carbon with a particle size of 30 nm and a specific surface area of 800 m² / g in a muffle furnace, calcine it at 350 °C for 2 hours to remove moisture and surface impurities, then cool it to room temperature, grind it into fine powder with a mortar, and pass through a 200-mesh sieve to obtain mesoporous carbon with moisture and impurities removed. (2) Mix perfluorooctyl sorbitol and absolute ethanol in a mass ratio of 1:4, and stir at a speed of 300 r / min at 30 °C for 60 minutes to obtain a perfluorooctyl sorbitol solution. (3) Mix the mesoporous carbon obtained in step (1) and the perfluorooctyl sorbitol solution in a mass ratio of 1:5 and perform ultrasonic treatment at 30 °C, with a power of 400 W, a frequency of 40 kHz, and a time of 60 minutes. (4) Add isocyanato-1-trimethoxysilane methyl ester to the dispersion system obtained in step (3) at a rate of 2 drops per minute, and simultaneously add dibutyltin dilaurate at 0.3% of the mass of isocyanato-1-trimethoxysilane methyl ester. The mass ratio of isocyanato-1-trimethoxysilane methyl ester to mesoporous carbon is 0.5:1; after dropping, charge nitrogen for 15 minutes, stir and react at 70 °C at 300 r / min for 3 hours; then add deionized water at a mass ratio of deionized water to isocyanato-1-trimethoxysilane methyl ester of 3:1, and add a small amount of acetic acid at 0.1% of the mass of isocyanato-1-trimethoxysilane methyl ester, and stir at 300 r / min at room temperature for 2 hours to obtain a dispersion solution. (5) Mix the dispersion solution obtained in step (4), polypropylene, and maleic anhydride grafted polypropylene in a mass ratio of 1:17:2, transfer it to a twin-screw extruder, melt-extrude and pelletize to obtain mixed pellets; place the mixed pellets in an extrusion casting machine to cast a film with a thickness of 30 μm, and then perform double-sided corona treatment at a voltage of 12 kV, a frequency of 20 kHz, and a treatment speed of 35 m / min, and wind up to obtain a novel superhydrophobic CPP film.

[0019] Comparative Example 1. The difference between Comparative Example 1 and Example 1 is that no mesoporous carbon is added, and other steps are the same as in Example 1.

[0020] Comparative Example 2. The difference between Comparative Example 2 and Example 1 is that no perfluorooctyl sorbitol solution is added, and other steps are the same as in Example 1.

[0021] Comparative Example 3. The difference between Comparative Example 3 and Example 1 is that isocyanato-1-trimethoxysilane is not added, and other steps are the same as those in Example 1.

[0022] Performance test Wetting angle measuring instrument: JJC-1, Changchun General Factory of Optical Instruments.

[0023] The contact angle θ of secondary distilled water on the surface of the CPP film prepared in the examples and comparative examples was measured using a wetting angle measuring instrument. Each sample was measured 3 times at different positions, and the average value was taken.

[0024] The analysis results of the contact angle and surface energy of Examples 1 to 3 and Comparative Examples 1 to 4 of the present invention are given in Table 1 below.

[0025] Table 1

[0026] It can be seen from Table 1 that in the present invention, mesoporous carbon is dispersed in a perfluorooctyl sorbitol solution. Through ultrasonic infiltration treatment, perfluorooctyl sorbitol enters the pores of the mesoporous carbon and adheres to its surface, constructing a microscopic rough surface that can capture air, reducing the contact area between water and the CPP film, significantly increasing the water contact angle, and achieving superhydrophobic performance; then isocyanato-1-trimethoxysilane is added dropwise to the above dispersion system. Subsequently, an appropriate amount of deionized water is added to the above system and dispersed in polypropylene, causing isocyanato-1-trimethoxysilane to hydrolyze to form silanol groups, and the silanol groups can undergo a condensation reaction to connect mesoporous carbon, perfluorooctyl sorbitol, and polypropylene together, enhancing the stability and further improving the superhydrophobic performance.

[0027] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, in any aspect, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claimed rights.

Claims

1. A novel super-hydrophobic CPP film, comprising polypropylene, mesoporous carbon, perfluorooctyl sorbitol solution, 1-trimethoxysilylmethyl isocyanate, deionized water and acetic acid, characterized in that: The method comprises the following preparation steps: (1) Mixing the mesoporous carbon from which moisture and impurities have been removed with a perfluorooctyl sorbitol solution in a mass ratio of 1:3-5 and subjecting the mixture to ultrasonic treatment at 20-40° C., with a power of 200-400 W, a frequency of 20-40 kHz, and a time of 60-90 minutes; (2) adding 1-trimethoxysilylmethyl isocyanate to the dispersed system obtained in step (1) at a rate of 2-3 drops per minute, wherein the mass ratio of 1-trimethoxysilylmethyl isocyanate to mesoporous carbon is 0.2-0.5:

1. After the addition is completed, nitrogen is introduced for 10-15 minutes, and the mixture is stirred at 60-70° C. and 300-400 r / min for 2-4 hours; then, deionized water is added at a mass ratio of deionized water to 1-trimethoxysilylmethyl isocyanate of 2-3:1, and a small amount of acetic acid is added in an amount of 0.1-0.3% of the mass of 1-trimethoxysilylmethyl isocyanate, and the mixture is stirred at 200-300 r / min for 1-2 hours at room temperature to obtain a dispersed solution; (3) The dispersed solution obtained in step (2) and polypropylene are mixed in a mass ratio of 1:12-17, transferred to a twin-screw extruder, melt-extruded and granulated to obtain mixed pellets; the mixed pellets are placed in an extrusion casting machine to cast into a film with a thickness of 25-30 μm, and then double-sided corona treatment is performed at a voltage of 12 kV, a frequency of 20 kHz, and a processing speed of 35 m / min, and rolled up to obtain a new super-hydrophobic CPP film.

2. A novel super-hydrophobic CPP film according to claim 1, characterized in that, The novel super-hydrophobic CPP film also includes dibutyltin dilaurate.

3. A novel super-hydrophobic CPP film according to claim 1, characterized in that, The novel super-hydrophobic CPP film also includes maleic anhydride grafted polypropylene.

4. A novel super-hydrophobic CPP film according to claim 1, characterized in that, The perfluorooctyl sorbitol solution is obtained by mixing perfluorooctyl sorbitol and anhydrous ethanol.

5. A novel super-hydrophobic CPP film according to claim 1, characterized in that, In the step (1), the preparation method of the perfluorooctyl sorbitol solution comprises: mixing perfluorooctyl sorbitol and anhydrous ethanol in a mass ratio of 1:3-5, and stirring at a speed of 300-500 r / min for 30-60 minutes at 20-30°C.

6. A novel super-hydrophobic CPP film according to claim 1, characterized in that: In the step (1), the process of obtaining the medium carbon with moisture and impurities removed comprises: placing the mesoporous carbon with a particle size of 10-50 nm and a specific surface area of ​​≥500 m² / g in a muffle furnace, calcining at 300-400°C for 2-3 hours to remove moisture and surface impurities, then cooling to room temperature, grinding into fine powder with a mortar, and passing through a 200 mesh sieve.

7. A novel super-hydrophobic CPP film according to claim 1, characterized in that: In the step (1), the mass ratio of the mesoporous carbon to the perfluorooctyl sorbitol solution is preferably 1:

4.

8. A novel super-hydrophobic CPP film according to claim 1, characterized in that: In the step (2), the mass ratio of 1-trimethoxysilylmethyl isocyanate to mesoporous carbon is 0.3:1.

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