A preparation method of an antistatic polypropylene material

Abstract

The present invention provides a method for preparing an antistatic polypropylene material, comprising the following steps: S1: Add hydrogen peroxide to deep-sea fish oil, stir and react, remove the water layer, and wash to obtain oxidized deep-sea fish oil; S2: Place polyethylene glycol, oxidized deep-sea fish oil, and a catalyst in a reaction kettle, heat up and stir; wash and dry to obtain modified fish oil; S3: Add the modified fish oil to a nano-tourmaline powder ethanol dispersion, ultrasonically disperse while stirring, remove ethanol, and degas to obtain a nano-tourmaline powder / modified fish oil composite; S4: Use polypropylene, nano-tourmaline powder / modified fish oil composite, and antioxidant to prepare granulates for the outer layer of the film; use polypropylene and antioxidant to prepare granulates for the inner layer of the film; S5: Use the granulates for the outer layer of the film and the granulates for the inner layer of the film to prepare an antistatic polypropylene material by coextrusion casting process. The polypropylene material prepared by the present invention has excellent antistatic performance and improved mechanical properties at the same time.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and particularly relates to a method for preparing an antistatic polypropylene material. Background Art

[0002] Due to its high cost performance, non-toxicity, excellent mechanical properties, heat resistance, corrosion resistance, etc., polypropylene has broad application prospects and many advantages when used as a packaging material. However, static electricity is easily generated during the use of polypropylene film as a packaging material. Static electricity can cause impurities such as dust and pollutants to be easily adsorbed on the surface of the polypropylene film packaging material, which not only affects the aesthetics of the packaging material, but may also contaminate the packaged product and reduce the product quality. Therefore, it is necessary to perform antistatic treatment on the outer surface of the polypropylene film.

[0003] Currently, when performing antistatic treatment on the outer surface of polypropylene film, corona treatment is generally carried out. Corona treatment can ionize and activate the surface of the plastic film through the action of an electric field, and can also effectively remove static electricity on the plastic surface, reduce the adsorption of dust and pollutants, etc., and improve the overall quality of the product. However, the antistatic performance of the polypropylene film treated by this method is not persistent. Therefore, the method of adding an antistatic agent is used to eliminate the static electricity of polypropylene, and the antistatic persistence is significantly stronger.

[0004] Among them, fatty acid ester antistatic agents, as a type of non-ionic antistatic agent, are non-toxic or low-toxic, have stable thermal properties, excellent processing properties, good compatibility with polypropylene, and overall good antistatic effects. Currently, there are already literatures that mix fish oil, glycerol, and a catalyst, reflux and react to obtain modified fish oil, and add this modified fish oil as a fatty acid ester antistatic agent to polypropylene to prepare an antistatic polypropylene material, which can reduce both the surface resistivity and volume resistivity of polypropylene, and expand the use of fish oil. Among them, fish oil, as a by-product of fishery resources, the expansion of its use is beneficial to reducing the waste of fishery resources and improving the utilization efficiency of resources.

[0005] However, the improvement of the antistatic effect of the modified fish oil obtained in the prior art on polypropylene is still relatively limited. With the improvement of the product quality requirements for polypropylene film packaging materials in the packaging field, it is necessary to develop modified fish oil with more excellent antistatic performance, and at the same time, when the polypropylene material has excellent antistatic performance, it should also have excellent mechanical properties. Summary of the Invention

[0006] The object of the present invention is to provide a method for preparing an antistatic polypropylene material, which is a double-layer co-extruded film material. By adding an appropriate amount of antistatic agent to the outer layer of the polypropylene film, the outer layer of the polypropylene film has excellent antistatic effect and excellent mechanical properties. At the same time, the present invention uses deep-sea fish oil as the main raw material of the antistatic agent, effectively expanding the application of deep-sea fish oil.

[0007] To achieve the above object, the present invention is realized through the following technical solutions:

[0008] A method for preparing an antistatic polypropylene material, comprising the following steps:

[0009] S1: Under visible light conditions, add hydrogen peroxide to deep-sea fish oil, stir and react at 50-55 °C for 2.5-3 h, then remove the water layer, and wash the fish oil layer with sodium chloride solution to obtain oxidized deep-sea fish oil;

[0010] S2: Place polyethylene glycol, oxidized deep-sea fish oil, and catalyst in a reaction kettle, heat up to 130-135 °C with stirring and keep stirring for 3-5 h; after the reaction, wash with sodium chloride solution and then perform vacuum drying to obtain modified fish oil;

[0011] S3: Prepare a nano-tourmaline powder ethanol dispersion; add modified fish oil to the nano-tourmaline powder ethanol dispersion, disperse ultrasonically with stirring for 3-6 h, then remove ethanol by reduced pressure distillation with stirring, and after removing ethanol, perform vacuum degassing treatment to obtain a nano-tourmaline powder / modified fish oil composite;

[0012] S4: Mix polypropylene, nano-tourmaline powder / modified fish oil composite, and antioxidant in a high-speed mixer, and then place them in a twin-screw extruder for melt blending, extrusion, and pelletizing to obtain pellet materials for the outer layer of the film; mix polypropylene and antioxidant in a high-speed mixer, and then place them in a twin-screw extruder for melt blending, extrusion, and pelletizing to obtain pellet materials for the inner layer of the film;

[0013] S5: Add the pellet materials for the outer layer of the film and the pellet materials for the inner layer of the film to two screw extruders respectively for melting, and extrude the two layers of melt through a die head to be combined and formed into a cast film, and then through shaping, cooling, and winding to obtain the antistatic polypropylene material.

[0014] Preferably, in step S1, the deep-sea fish oil is one or a mixture of two or more of tuna oil, salmon oil, cod liver oil, sardine oil, and mackerel oil in any proportion.

[0015] Preferably, in step S1, the mass fraction of the hydrogen peroxide is 10-15%, and the addition amount of the hydrogen peroxide is 35-50% of the mass of the deep-sea fish oil.

[0016] Preferably, in step S2, the mass ratio of polyethylene glycol to oxidized deep-sea fish oil is 1:4 to 5.5; the average molecular weight of the polyethylene glycol is 400 to 600.

[0017] Preferably, in step S2, the catalyst is an aqueous solution of sodium bisulfate, the mass fraction of the aqueous solution of sodium bisulfate is 30 to 40%, and the dosage of the aqueous solution of sodium bisulfate is 1.5 to 2% of the mass of oxidized deep-sea fish oil;

[0018] During the reaction, the water in the aqueous solution of sodium bisulfate and the water generated by the reaction are discharged after being condensed by a condenser.

[0019] Preferably, in steps S1 and S2, the mass fraction of the sodium chloride solution is 2 to 3%.

[0020] Preferably, in step S3, in the nano-tourmaline powder ethanol dispersion, the concentration of nano-tourmaline powder is 30 to 60 mg / mL; the preparation method of the nano-tourmaline powder ethanol dispersion includes the following steps: adding nano-tourmaline powder with a particle size of 50 to 200 nm to absolute ethanol, and ultrasonically dispersing for 2 to 5 h while stirring to obtain it.

[0021] Preferably, in step S3, the mass-volume ratio of the modified fish oil to the nano-tourmaline powder ethanol dispersion is 1 g:3 to 5 mL.

[0022] Preferably, in step S4, the film outer layer material particles include the following raw materials in weight percentages: 2.2 to 3.5% of nano-tourmaline powder / modified fish oil composite, 0.2 to 0.3% of antioxidant, and the balance is polypropylene;

[0023] The film inner layer material particles include the following raw materials in weight percentages: 0.05 to 0.1% of antioxidant, and the balance is polypropylene.

[0024] Preferably, in step S4, when preparing the film outer layer material particles and the film inner layer material particles, the temperature of twin-screw extrusion is 170 to 195 °C, and the temperatures from zone 1 to zone 10 are respectively: 170 °C, 170 °C, 175 °C, 180 °C, 185 °C, 190 °C, 190 °C, 185 °C, 180 °C, 180 °C, and the head temperature is 195 °C.

[0025] The beneficial effects of the present invention are:

[0026] 1. The present invention uses oxidized deep-sea fish oil to react with polyethylene glycol to prepare modified fish oil. By reasonably controlling the reaction conditions, the addition amount and molecular weight of polyethylene glycol, etc., the prepared modified fish oil can contain more polyethylene glycol fatty acid esters, making the modified fish oil exhibit higher antistatic performance and better compatibility with polypropylene.

[0027] 2. In the process of preparing the modified fish oil of the present invention, the deep-sea fish oil is first oxidized with an appropriate amount of hydrogen peroxide. After the oxidation treatment with hydrogen peroxide, the reaction activity of the deep-sea fish oil increases, and the prepared modified fish oil as a whole exhibits more excellent antistatic performance. Moreover, the composite prepared with nano-tourmaline powder shows better effects both in antistatic performance and mechanical properties. However, if too much hydrogen peroxide is used for oxidation treatment and the oxidation time is too long, over-oxidation will occur, which will lead to a decrease in the performance of the modified fish oil.

[0028] 3. On the basis of the prepared modified fish oil of the present invention, it is mixed with the ethanol dispersion of nano-tourmaline powder and subjected to stirring and ultrasonic dispersion treatment. After removing ethanol by vacuum distillation subsequently, the nano-tourmaline powder can be highly dispersed in the modified fish oil. When preparing the antistatic polypropylene material by mixing the prepared antistatic agent nano-tourmaline powder / modified fish oil composite with polypropylene, the nano-tourmaline powder is highly dispersed in polypropylene, and the compatibility between the nano-tourmaline powder and polypropylene is significantly enhanced. The highly dispersed nano-tourmaline powder can significantly reduce the volume resistivity and surface resistivity of the polypropylene material, and significantly improve the antistatic performance of the polypropylene material. At the same time, the addition of nano-tourmaline powder can also enhance the strength, toughness and heat resistance of the polypropylene material, etc.

[0029] 4. The antistatic polypropylene material of the present invention is a double-layer co-extruded film material. By adding an appropriate amount of antistatic agent to the outer layer of the polypropylene film, the outer layer of the polypropylene film has excellent antistatic effect, effectively reducing the adsorption of impurities such as dust and pollutants, and having excellent mechanical properties, making the polypropylene film packaging material not easily damaged; at the same time, the present invention uses deep-sea fish oil as the main raw material of the antistatic agent, effectively expanding the application of deep-sea fish oil. Specific embodiments

[0030] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0031] Example 1:

[0032] A method for preparing an antistatic polypropylene material, comprising the following steps:

[0033] S1: Under visible light conditions, add hydrogen peroxide with a mass fraction of 12% to tuna oil, and the addition amount of hydrogen peroxide is 40% of the mass of deep-sea fish oil; stir and react at 55 °C for 3 h, with a stirring speed of 120 r / min, then remove the water layer, and wash the fish oil layer with a sodium chloride solution with a mass fraction of 3% to obtain oxidized deep-sea fish oil;

[0034] S2: Add polyethylene glycol 400 and oxidized deep-sea fish oil with a mass ratio of 1:5 to the reaction kettle, and then add an aqueous solution of sodium bisulfate with a mass fraction of 35% and 2% of the mass of oxidized deep-sea fish oil to the reaction kettle; heat up to 135 °C with stirring and keep stirring for 3 h, with a stirring speed of 200 r / min. During the reaction, the water in the aqueous solution of sodium bisulfate and the water generated by the reaction are discharged after being condensed by the condenser; after the reaction, wash with a sodium chloride solution with a mass fraction of 3%, and then perform vacuum drying to remove residual moisture to obtain modified fish oil;

[0035] S3: Add nano-tourmaline powder with a particle size of 50 - 200 nm to absolute ethanol, stir and ultrasonically disperse for 3 h, with a stirring speed of 360 r / min and an ultrasonic power of 500 W to prepare a nano-tourmaline powder ethanol dispersion with a concentration of 50 mg / mL;

[0036] Add modified fish oil to the nano-tourmaline powder ethanol dispersion, and the mass-volume ratio of modified fish oil to nano-tourmaline powder ethanol dispersion is 1 g:5 mL; stir and ultrasonically disperse for 5 h, with a stirring speed of 360 r / min and an ultrasonic power of 300 W, and then remove ethanol by stirring and vacuum distillation. After removing ethanol, perform vacuum degassing treatment to obtain a nano-tourmaline powder / modified fish oil composite;

[0037] S4: Mix polypropylene, nano-tourmaline powder / modified fish oil composite, and antioxidant 1010 in a high-speed mixer, and then place them in a twin-screw extruder for melt blending, extrusion, and pelletizing to obtain pellet materials for the outer layer of the film; mix polypropylene and antioxidant 1010 in a high-speed mixer, and then place them in a twin-screw extruder for melt blending, extrusion, and pelletizing to obtain pellet materials for the inner layer of the film; when preparing the pellet materials for the outer layer of the film and the pellet materials for the inner layer of the film, the temperature of twin-screw extrusion is 170 - 195 °C, and the temperatures from zone 1 to zone 10 are: 170 °C, 170 °C, 175 °C, 180 °C, 185 °C, 190 °C, 190 °C, 185 °C, 180 °C, 180 °C, and the temperature of the die head is 195 °C.

[0038] The pellet materials for the outer layer of the film include the following raw materials by weight percentage: 3% of nano-tourmaline powder / modified fish oil composite, 0.2% of antioxidant 1010, and the balance is polypropylene; the pellet materials for the inner layer of the film include the following raw materials by weight percentage: 0.1% of antioxidant 1010, and the balance is polypropylene.

[0039] S5: Add the outer-layer material pellets and inner-layer material pellets of the film into two screw extruders respectively for melting, and extrude and combine the two layers of melt through a die head to form a cast film, and then carry out shaping, cooling and winding to obtain the antistatic polypropylene material.

[0040] Example 2:

[0041] A preparation method of an antistatic polypropylene material, comprising the following steps:

[0042] S1: Under visible light conditions, add hydrogen peroxide with a mass fraction of 15% to tuna oil, and the addition amount of hydrogen peroxide is 35% of the mass of deep-sea fish oil; stir and react at 52 °C for 2.5 h, and the stirring speed is 120 r / min, then remove the water layer, and wash the fish oil layer with a sodium chloride solution with a mass fraction of 3% to obtain oxidized deep-sea fish oil;

[0043] S2: Add polyethylene glycol 600 and oxidized deep-sea fish oil with a mass ratio of 1:5.5 into the reaction kettle, and then add an aqueous solution of sodium bisulfate with a mass fraction of 40% and an amount of 1.5% of the mass of oxidized deep-sea fish oil into the reaction kettle; heat up to 130 °C while stirring and keep stirring for 4 h, and the stirring speed is 200 r / min. During the reaction, the water in the aqueous solution of sodium bisulfate and the water generated by the reaction are discharged after being condensed by a condenser; after the reaction is completed, wash with a sodium chloride solution with a mass fraction of 3%, and then carry out vacuum drying to remove residual moisture to obtain modified fish oil;

[0044] S3: Add nano-tourmaline powder with a particle size of 50-200 nm into absolute ethanol, and carry out ultrasonic dispersion for 3 h while stirring, the stirring speed is 360 r / min, and the ultrasonic power is 500 W to prepare a nano-tourmaline powder ethanol dispersion with a concentration of 50 mg / mL;

[0045] Add modified fish oil to the nano-tourmaline powder ethanol dispersion, and the mass-volume ratio of modified fish oil to nano-tourmaline powder ethanol dispersion is 1 g:5 mL; carry out ultrasonic dispersion for 4 h while stirring, the stirring speed is 360 r / min, and the ultrasonic power is 300 W, and then carry out reduced-pressure distillation to remove ethanol while stirring. After removing ethanol, carry out vacuum degassing treatment to obtain a nano-tourmaline powder / modified fish oil composite;

[0046] S4: Mix polypropylene, nano-tourmaline powder / modified fish oil composite, and antioxidant 1010 in a high-speed mixer, and then place them in a twin-screw extruder for melt blending, extrusion, and pelletizing to obtain pellet materials for the outer layer of the film; mix polypropylene and antioxidant 1010 in a high-speed mixer, and then place them in a twin-screw extruder for melt blending, extrusion, and pelletizing to obtain pellet materials for the inner layer of the film; when preparing the pellet materials for the outer layer of the film and the inner layer of the film, the temperature of the twin-screw extrusion is 170 - 195°C, and the temperatures from zone 1 to zone 10 are respectively: 170°C, 170°C, 175°C, 180°C, 185°C, 190°C, 190°C, 185°C, 180°C, 180°C, and the temperature of the die head is 195°C.

[0047] The pellet materials for the outer layer of the film include the following raw materials by weight percentage: nano-tourmaline powder / modified fish oil composite 3.5%, antioxidant 1010 0.2%, and the balance is polypropylene; the pellet materials for the inner layer of the film include the following raw materials by weight percentage: antioxidant 1010 0.05%, and the balance is polypropylene.

[0048] S5: Add the pellet materials for the outer layer of the film and the inner layer of the film into two screw extruders respectively for melting, and extrude the two layers of melt through a die head to be combined to form a cast film, and then through shaping, cooling, and winding to obtain the antistatic polypropylene material.

[0049] Example 3:

[0050] A method for preparing an antistatic polypropylene material, comprising the following steps:

[0051] S1: Under visible light conditions, add hydrogen peroxide with a mass fraction of 10% to tuna oil, and the addition amount of hydrogen peroxide is 50% of the mass of deep-sea fish oil; stir and react at 52°C for 3 h, with a stirring speed of 120 r / min, then remove the water layer, and wash the fish oil layer with a sodium chloride solution with a mass fraction of 2% to obtain oxidized deep-sea fish oil;

[0052] S2: Add polyethylene glycol 600 and oxidized deep-sea fish oil with a mass ratio of 1:4 to the reaction kettle, and then add an aqueous solution of sodium bisulfate with a mass of 2% of the oxidized deep-sea fish oil, and the mass fraction of the aqueous solution of sodium bisulfate is 35%; heat and stir to 135°C while stirring and keep stirring for 4 h, with a stirring speed of 200 r / min. During the reaction, the water in the aqueous solution of sodium bisulfate and the water generated by the reaction are discharged after being condensed by a condenser; after the reaction, wash with a sodium chloride solution with a mass fraction of 2%, and then conduct vacuum drying to remove residual moisture to obtain modified fish oil;

[0053] S3: Add tourmaline powder nanoparticles with a particle size of 50 - 200 nm to absolute ethanol, and ultrasonically disperse while stirring for 3.5 h. The stirring speed is 360 r / min, and the ultrasonic power is 500 W to prepare a tourmaline powder ethanol dispersion with a concentration of 45 mg / mL;

[0054] Add modified fish oil to the tourmaline powder ethanol dispersion. The mass - to - volume ratio of the modified fish oil to the tourmaline powder ethanol dispersion is 1 g:3 mL; ultrasonically disperse while stirring for 5.5 h. The stirring speed is 360 r / min, and the ultrasonic power is 300 W. Then, while stirring, remove ethanol by reduced - pressure distillation. After removing ethanol, perform vacuum degassing treatment to obtain a tourmaline powder / modified fish oil composite;

[0055] S4: Mix polypropylene, tourmaline powder / modified fish oil composite, and antioxidant 1010 in a high - speed mixer, and then place them in a twin - screw extruder for melt blending, extrusion, and pelletizing to obtain pellet materials for the outer layer of the film; Mix polypropylene and antioxidant 1010 in a high - speed mixer, and then place them in a twin - screw extruder for melt blending, extrusion, and pelletizing to obtain pellet materials for the inner layer of the film. When preparing the pellet materials for the outer layer of the film and the pellet materials for the inner layer of the film, the temperature of the twin - screw extrusion is 170 - 195 °C, and the temperatures from zone 1 to zone 10 are: 170 °C, 170 °C, 175 °C, 180 °C, 185 °C, 190 °C, 190 °C, 185 °C, 180 °C, 180 °C, and the head temperature is 195 °C.

[0056] The pellet materials for the outer layer of the film include the following raw materials by weight percentage: 3% of tourmaline powder / modified fish oil composite, 0.2% of antioxidant 1010, and the balance is polypropylene; The pellet materials for the inner layer of the film include the following raw materials by weight percentage: 0.1% of antioxidant 1010, and the balance is polypropylene.

[0057] S5: Add the pellet materials for the outer layer of the film and the pellet materials for the inner layer of the film to two screw extruders respectively for melting, and extrude the two layers of melts through a die head to be combined to form a cast film, and then through shaping, cooling, and winding to obtain the antistatic polypropylene material.

[0058] Example 4:

[0059] A method for preparing an antistatic polypropylene material, comprising the following steps:

[0060] S1: Under visible light conditions, add hydrogen peroxide with a mass fraction of 10% to tuna oil. The addition amount of hydrogen peroxide is 35% of the mass of deep - sea fish oil; Stir and react at 50 °C for 3 h, with a stirring speed of 120 r / min. Then remove the water layer, and wash the fish oil layer with a sodium chloride solution with a mass fraction of 3% to obtain oxidized deep - sea fish oil;

[0061] S2: Add polyethylene glycol 400 and oxidized deep-sea fish oil with a mass ratio of 1:4 into the reaction kettle. Then add an aqueous sodium bisulfate solution accounting for 2% of the mass of the oxidized deep-sea fish oil into the reaction kettle. The mass fraction of the aqueous sodium bisulfate solution is 30%. While stirring, heat up to 135 °C and keep stirring at a constant temperature for 3 h. The stirring speed is 200 r / min. During the reaction, the water in the aqueous sodium bisulfate solution and the water generated by the reaction are discharged after being condensed by the condenser. After the reaction ends, wash with a sodium chloride solution with a mass fraction of 3%, and then perform vacuum drying to remove residual moisture to obtain modified fish oil;

[0062] S3: Add nano-tourmaline powder with a particle size of 50 - 200 nm into absolute ethanol. While stirring, perform ultrasonic dispersion for 5 h. The stirring speed is 360 r / min, and the ultrasonic power is 500 W to prepare a nano-tourmaline powder ethanol dispersion with a concentration of 60 mg / mL;

[0063] Add modified fish oil into the nano-tourmaline powder ethanol dispersion. The mass-to-volume ratio of the modified fish oil to the nano-tourmaline powder ethanol dispersion is 1 g:5 mL. While stirring, perform ultrasonic dispersion for 4 h. The stirring speed is 360 r / min, and the ultrasonic power is 300 W. Then, while stirring, perform vacuum distillation to remove ethanol. After removing ethanol, perform vacuum degassing treatment to obtain a nano-tourmaline powder / modified fish oil composite;

[0064] S4: Mix polypropylene, nano-tourmaline powder / modified fish oil composite, and antioxidant 1010 in a high-speed mixer, and then place them in a twin-screw extruder for melt blending, extrusion, and pelletizing to obtain pellet materials for the outer layer of the film. Mix polypropylene and antioxidant 1010 in a high-speed mixer, and then place them in a twin-screw extruder for melt blending, extrusion, and pelletizing to obtain pellet materials for the inner layer of the film. When preparing the pellet materials for the outer layer of the film and the pellet materials for the inner layer of the film, the temperature of the twin-screw extrusion is 170 - 195 °C. The temperatures from zone 1 to zone 10 are respectively: 170 °C, 170 °C, 175 °C, 180 °C, 185 °C, 190 °C, 190 °C, 185 °C, 180 °C, 180 °C, and the head temperature is 195 °C.

[0065] The pellet materials for the outer layer of the film include the following raw materials by weight percentage: 2.8% of nano-tourmaline powder / modified fish oil composite, 0.3% of antioxidant 1010, and the balance is polypropylene; the pellet materials for the inner layer of the film include the following raw materials by weight percentage: 0.08% of antioxidant 1010, and the balance is polypropylene.

[0066] S5: Add the pellet materials for the outer layer of the film and the pellet materials for the inner layer of the film into two screw extruders respectively for melting, and extrude the two layers of melt through a die head to be combined to form a cast film, and then perform shaping, cooling, and winding to obtain the antistatic polypropylene material.

[0067] Example 5:

[0068] A preparation method of an antistatic polypropylene material, comprising the following steps:

[0069] S1: Under visible light conditions, add hydrogen peroxide with a mass fraction of 12% to tuna oil, and the addition amount of hydrogen peroxide is 50% of the mass of deep-sea fish oil; stir and react at 52 °C for 2.5 h, with a stirring speed of 120 r / min, then remove the water layer, and wash the fish oil layer with a sodium chloride solution with a mass fraction of 2% to obtain oxidized deep-sea fish oil;

[0070] S2: Add polyethylene glycol 600 and oxidized deep-sea fish oil with a mass ratio of 1:4.5 to the reaction kettle, and then add an aqueous solution of sodium bisulfate with a mass fraction of 40% and 1.8% of the mass of oxidized deep-sea fish oil to the reaction kettle; heat up to 130 °C with stirring and stir constantly for 5 h, with a stirring speed of 200 r / min. During the reaction, the water in the aqueous solution of sodium bisulfate and the water generated by the reaction are discharged after being condensed by the condenser; after the reaction is completed, wash with a sodium chloride solution with a mass fraction of 2%, and then perform vacuum drying to remove residual moisture to obtain modified fish oil;

[0071] S3: Add nano-tourmaline powder with a particle size of 50 - 200 nm to absolute ethanol, and disperse it by ultrasonic wave with stirring for 2 h, with a stirring speed of 360 r / min and an ultrasonic power of 500 W to prepare a nano-tourmaline powder ethanol dispersion with a concentration of 30 mg / mL;

[0072] Add modified fish oil to the nano-tourmaline powder ethanol dispersion, and the mass-volume ratio of modified fish oil to nano-tourmaline powder ethanol dispersion is 1 g:3.5 mL; disperse it by ultrasonic wave with stirring for 3 h, with a stirring speed of 360 r / min and an ultrasonic power of 300 W, and then remove ethanol by distillation under reduced pressure with stirring. After removing ethanol, perform vacuum degassing treatment to obtain a nano-tourmaline powder / modified fish oil composite;

[0073] S4: Mix polypropylene, nano-tourmaline powder / modified fish oil composite, and antioxidant 1010 in a high-speed mixer, and then place them in a twin-screw extruder for melt blending, extrusion, and pelletizing to obtain pellet materials for the outer layer of the film; mix polypropylene and antioxidant 1010 in a high-speed mixer, and then place them in a twin-screw extruder for melt blending, extrusion, and pelletizing to obtain pellet materials for the inner layer of the film; when preparing the pellet materials for the outer layer of the film and the pellet materials for the inner layer of the film, the temperature of the twin-screw extrusion is 170 - 195 °C, and the temperatures from zone 1 to zone 10 are: 170 °C, 170 °C, 175 °C, 180 °C, 185 °C, 190 °C, 190 °C, 185 °C, 180 °C, 180 °C, and the head temperature is 195 °C.

[0074] The pellet for the outer layer of the film comprises the following raw materials by weight percentage: 3% of nano-tourmaline powder / modified fish oil complex, 0.25% of antioxidant 1010, and the balance is polypropylene; the pellet for the inner layer of the film comprises the following raw materials by weight percentage: 0.1% of antioxidant 1010, and the balance is polypropylene.

[0075] S5: Add the pellet for the outer layer of the film and the pellet for the inner layer of the film into two screw extruders respectively for melting, and extrude and combine the two layers of melt through a die head to form a cast film, and then carry out shaping, cooling and winding to obtain the antistatic polypropylene material.

[0076] Example 6:

[0077] A preparation method of an antistatic polypropylene material comprises the following steps:

[0078] S1: Under visible light conditions, add hydrogen peroxide with a mass fraction of 15% to tuna oil, and the addition amount of hydrogen peroxide is 45% of the mass of deep-sea fish oil; stir and react at 55 °C for 2.5 h, the stirring speed is 120 r / min, then remove the water layer, and wash the fish oil layer with a sodium chloride solution with a mass fraction of 2% to obtain oxidized deep-sea fish oil;

[0079] S2: Add polyethylene glycol 600 and oxidized deep-sea fish oil with a mass ratio of 1:5.5 into the reaction kettle, and then add an aqueous solution of sodium bisulfate with a mass fraction of 35% and 1.5% of the mass of oxidized deep-sea fish oil into the reaction kettle; heat up to 133 °C while stirring and keep stirring for 4 h, the stirring speed is 200 r / min. During the reaction, the water in the aqueous solution of sodium bisulfate and the water generated by the reaction are discharged after being condensed by a condenser; after the reaction is completed, wash with a sodium chloride solution with a mass fraction of 2%, and then carry out vacuum drying to remove residual moisture to obtain modified fish oil;

[0080] S3: Add nano-tourmaline powder with a particle size of 50-200 nm into absolute ethanol, stir and disperse ultrasonically for 3 h, the stirring speed is 360 r / min, and the ultrasonic power is 500 W to prepare a nano-tourmaline powder ethanol dispersion with a concentration of 45 mg / mL;

[0081] Add modified fish oil into the nano-tourmaline powder ethanol dispersion, and the mass-volume ratio of modified fish oil to nano-tourmaline powder ethanol dispersion is 1 g:3 mL; stir and disperse ultrasonically for 6 h, the stirring speed is 360 r / min, and the ultrasonic power is 300 W, then stir and carry out vacuum distillation to remove ethanol. After removing ethanol, carry out vacuum degassing treatment to obtain nano-tourmaline powder / modified fish oil complex;

[0082] S4: Mix polypropylene, nano-tourmaline powder / modified fish oil composite, and antioxidant 1010 in a high-speed mixer, then place them in a twin-screw extruder for melt blending, extrusion, and pelletizing to obtain pellet materials for the outer layer of the film; mix polypropylene and antioxidant 1010 in a high-speed mixer, then place them in a twin-screw extruder for melt blending, extrusion, and pelletizing to obtain pellet materials for the inner layer of the film. When preparing the pellet materials for the outer layer and the inner layer of the film, the temperature of the twin-screw extrusion is 170 - 195°C, and the temperatures from zone 1 to zone 10 are respectively: 170°C, 170°C, 175°C, 180°C, 185°C, 190°C, 190°C, 185°C, 180°C, 180°C, and the temperature of the die head is 195°C.

[0083] The pellet materials for the outer layer of the film include the following raw materials by weight percentage: nano-tourmaline powder / modified fish oil composite 3.2%, antioxidant 1010 0.22%, and the balance is polypropylene; the pellet materials for the inner layer of the film include the following raw materials by weight percentage: antioxidant 1010 0.06%, and the balance is polypropylene.

[0084] S5: Add the pellet materials for the outer layer and the inner layer of the film into two screw extruders respectively for melting, and extrude the two layers of melt through the die head to be combined to form a cast film, then through shaping, cooling, and winding to obtain the antistatic polypropylene material.

[0085] Comparative Example 1:

[0086] The difference from Example 1 is that deep-sea fish oil is not oxidized with hydrogen peroxide; the preparation method of the modified fish oil includes the following steps:

[0087] Add polyethylene glycol 400 and deep-sea fish oil with a mass ratio of 1:5 into the reaction kettle, then add an aqueous sodium bisulfate solution with 2% of the mass of the deep-sea fish oil, and the mass fraction of the aqueous sodium bisulfate solution is 35%; heat up to 135°C with stirring and keep stirring for 3 h, and the stirring speed is 200 r / min. During the reaction, the water in the aqueous sodium bisulfate solution and the water generated by the reaction are discharged after being condensed by the condenser; after the reaction is completed, wash with a sodium chloride solution with a mass fraction of 3%, and then perform vacuum drying to remove the residual moisture to obtain the modified fish oil.

[0088] Comparative Example 2:

[0089] The difference from Example 1 is that a nano-tourmaline powder / modified fish oil composite is not prepared by using a nano-tourmaline powder ethanol dispersion and the modified fish oil, and the modified fish oil and nano-tourmaline powder are directly used to prepare the pellet materials for the outer layer of the film.

[0090] The preparation method of the pellet materials for the outer layer of the film includes the following steps:

[0091] Mix polypropylene, modified fish oil (prepared in the same method as in Example 1), nano-tourmaline powder (particle size 50 - 200 nm), and antioxidant 1010 in a high-speed mixer, and then place them in a twin-screw extruder for melt blending, extrusion, and pelletizing to obtain the pellet for the outer layer of the film. The temperature for twin-screw extrusion is 170 - 195 °C, and the temperatures from zone 1 to zone 10 are respectively: 170 °C, 170 °C, 175 °C, 180 °C, 185 °C, 190 °C, 190 °C, 185 °C, 180 °C, 180 °C, and the head temperature is 195 °C.

[0092] The pellet for the outer layer of the film comprises raw materials in the following weight percentages: 2.5% of modified fish oil, 0.5% of nano-tourmaline powder, 0.2% of antioxidant 1010, and the balance is polypropylene.

[0093] Comparative Example 3:

[0094] The difference from Example 1 lies in that the oxidation treatment process of deep-sea fish oil in step S1 is different. The preparation method of oxidized deep-sea fish oil comprises the following steps: Under visible light conditions, add hydrogen peroxide with a mass fraction of 30% to tuna oil, and the addition amount of hydrogen peroxide is 80% of the mass of deep-sea fish oil; stir and react at 55 °C for 5 h, with a stirring speed of 120 r / min, then remove the water layer, and wash the fish oil layer with a sodium chloride solution with a mass fraction of 3% to obtain oxidized deep-sea fish oil.

[0095] Comparative Example 4:

[0096] The difference from Example 1 lies in that the addition amounts of oxidized deep-sea fish oil and polyethylene glycol in step S2 are different, and the molecular weight of the polyethylene glycol used is different.

[0097] The preparation method of modified fish oil comprises the following steps: Add polyethylene glycol 800 and oxidized deep-sea fish oil (prepared in the same method as in Example 1) with a mass ratio of 1:7.5 to the reaction kettle, and then add an aqueous sodium bisulfate solution with a mass of 2% of the oxidized deep-sea fish oil to the reaction kettle, and the mass fraction of the aqueous sodium bisulfate solution is 35%; heat while stirring to 135 °C and keep stirring for 3 h, with a stirring speed of 200 r / min. During the reaction, the water in the aqueous sodium bisulfate solution and the water generated by the reaction are discharged after being condensed by the condenser; after the reaction is completed, wash with a sodium chloride solution with a mass fraction of 3%, and then perform vacuum drying to remove residual moisture to obtain modified fish oil.

[0098] Comparative Example 5:

[0099] The difference from Example 1 lies in that only nano-tourmaline powder is used as the antistatic agent, and the preparation method of the pellet for the outer layer of the film comprises the following steps:

[0100] Mix polypropylene, nano-tourmaline powder (particle size 50 - 200 nm), and antioxidant 1010 in a high-speed mixer, then place them in a twin-screw extruder for melt blending, extrusion, and pelletizing to obtain the pellet material for the outer layer of the film. The temperature for twin-screw extrusion is 170 - 195 °C, and the temperatures from zone 1 to zone 10 are respectively: 170 °C, 170 °C, 175 °C, 180 °C, 185 °C, 190 °C, 190 °C, 185 °C, 180 °C, 180 °C, and the head temperature is 195 °C.

[0101] The pellet material for the outer layer of the film includes raw materials with the following weight percentages: nano-tourmaline powder 1%, antioxidant 1010 0.2%, and the balance is polypropylene.

[0102] Comparative Example 6:

[0103] The difference from Example 1 is that only modified fish oil is used as the antistatic agent, and the preparation method of the pellet material for the outer layer of the film includes the following steps:

[0104] Mix polypropylene, modified fish oil (prepared in the same way as in Example 1), and antioxidant 1010 in a high-speed mixer, then place them in a twin-screw extruder for melt blending, extrusion, and pelletizing to obtain the pellet material for the outer layer of the film. The temperature for twin-screw extrusion is 170 - 195 °C, and the temperatures from zone 1 to zone 10 are respectively: 170 °C, 170 °C, 175 °C, 180 °C, 185 °C, 190 °C, 190 °C, 185 °C, 180 °C, 180 °C, and the head temperature is 195 °C.

[0105] The pellet material for the outer layer of the film includes raw materials with the following weight percentages: modified fish oil 3%, antioxidant 1010 0.2%, and the balance is polypropylene.

[0106] Comparative Example 7:

[0107] The difference from Example 1 is that no antistatic agent is added, and the preparation method of the pellet material for the outer layer of the film includes the following steps:

[0108] Mix polypropylene and antioxidant 1010 in a high-speed mixer, then place them in a twin-screw extruder for melt blending, extrusion, and pelletizing to obtain the pellet material for the outer layer of the film. The temperature for twin-screw extrusion is 170 - 195 °C, and the temperatures from zone 1 to zone 10 are respectively: 170 °C, 170 °C, 175 °C, 180 °C, 185 °C, 190 °C, 190 °C, 185 °C, 180 °C, 180 °C, and the head temperature is 195 °C.

[0109] The pellet material for the outer layer of the film includes raw materials with the following weight percentages: antioxidant 1010 0.2%, and the balance is polypropylene.

[0110] Performance test:

[0111] The film outer layer material pellets used in the antistatic polypropylene materials in Examples 1 to 6 and Comparative Examples 1 to 7 were prepared into corresponding polypropylene material test samples, and the resistivity and mechanical properties were tested.

[0112] 1. The surface resistivity and volume resistivity were tested in accordance with GB / T 1410-2006. The sample size was 100 mm×100mm×4 mm. The resistivity test results are shown in Table 1.

[0113] Table 1:

[0114]

[0115] Comparing the resistivity test results of the polypropylene materials in Examples 1 to 6 in Table 1 with those of Comparative Example 7, it can be seen that using the method of the present invention to prepare the film outer layer material pellets can significantly reduce the surface resistivity and volume resistivity of the corresponding polypropylene materials, effectively improving their antistatic effect. Comparing Example 1 with Comparative Example 1 and Comparative Example 3, it can be seen that if the deep-sea fish oil is not oxidized or over-oxidized, the antistatic performance of the obtained modified fish oil will be reduced. At the same time, the change in the properties of the modified fish oil will also affect the dispersion of the nano-tourmaline powder, thereby affecting the antistatic performance of the nano-tourmaline powder. Comparing Example 1 with Comparative Example 2, it can be seen that not using the nano-tourmaline powder ethanol dispersion to prepare the nano-tourmaline powder / modified fish oil composite with the modified fish oil will also weaken the antistatic effect of the polypropylene material. Comparing Example 1 with Comparative Example 4, it can be seen that when preparing the modified fish oil, if the addition amount of polyethylene glycol is small and the molecular weight is large, the resistivity will also decrease. Comparing Example 1 with Comparative Examples 5 and 6, it can be seen that if only nano-tourmaline powder or modified fish oil is used as the antistatic agent, the antistatic effect of the obtained polypropylene material will be significantly reduced.

[0116] 2. The tensile strength was tested in accordance with the method in GB / T1040.1-2018 "Determination of Tensile Properties of Plastics", and the notched impact strength was tested in accordance with the method in GB / T1843-2008 "Determination of Izod Impact Strength of Plastics".

[0117] Table 2:

[0118]

[0119] Comparing the mechanical property test results of the polypropylene materials in Examples 1 to 6 in Table 2 with Comparative Example 7, it can be seen that the use of the pellet for the anti-film outer layer prepared by the method of the present invention can improve the mechanical properties of the corresponding polypropylene materials. Comparing Example 1 in Table 2 with Comparative Example 1, it can be seen that if the deep-sea fish oil is not oxidized, both the tensile strength and the notched impact strength will decrease. It may be that after the deep-sea fish oil is oxidized and the properties of the obtained modified fish oil are changed, the dispersion property of the nano-tourmaline powder and its compatibility with polypropylene are enhanced. Comparing Example 1 with Comparative Example 2, it can be seen that without using the ethanol dispersion of nano-tourmaline powder and the modified fish oil to prepare the nano-tourmaline powder / modified fish oil composite, the mechanical properties are significantly weakened. It may be that the direct addition of nano-tourmaline powder leads to an increase in the agglomeration of nano-tourmaline powder, thus affecting the mechanical properties. Comparing Example 1 with Comparative Example 3, it can be seen that if the deep-sea fish oil is over-oxidized, it will also lead to a decrease in the mechanical properties of polypropylene. Comparing Example 1 with Comparative Example 4, it can be seen that when preparing the modified fish oil, if the addition amount of polyethylene glycol is small and the molecular weight is large, it will have some influence on its mechanical properties. Comparing Example 1 with Comparative Example 5, it can be seen that even if the addition amount of nano-tourmaline powder increases, but without matching an appropriate amount of modified fish oil, the mechanical properties of polypropylene will slightly weaken. Comparing Example 1 with Comparative Example 6, it can be seen that if only the modified fish oil is used as the antistatic agent, the mechanical properties of polypropylene will decrease significantly.

[0120] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing an antistatic polypropylene material, characterized in that: The following steps are involved: S1: under visible light conditions, adding hydrogen peroxide to the deep-sea fish oil, stirring and reacting at 50-55° C. for 2.5-3 hours, then removing the water layer, and washing the fish oil layer with a sodium chloride solution to obtain oxidized deep-sea fish oil; the mass fraction of the hydrogen peroxide is 10-15%, and the amount of the hydrogen peroxide added is 35-50% of the mass of the deep-sea fish oil; S2: placing polyethylene glycol, oxidized deep-sea fish oil and a catalyst in a reaction kettle, heating to 130-135° C. while stirring and stirring at a constant temperature for 3-5 hours; after the reaction is completed, washing with a sodium chloride solution and then vacuum drying to obtain a modified fish oil; the mass ratio of the polyethylene glycol to the oxidized deep-sea fish oil is 1:4-5.5; S3: preparing a nano-tourmaline powder ethanol dispersion; adding modified fish oil to the nano-tourmaline powder ethanol dispersion, dispersing the mixture by ultrasonic stirring for 3 to 6 hours, and then removing the ethanol by vacuum distillation while stirring. After removing the ethanol, vacuum degassing is performed to obtain a nano-tourmaline powder / modified fish oil composite; S4: mixing polypropylene, nano-tourmaline powder / modified fish oil compound and antioxidant in a high-speed mixer, and then placing them in a twin-screw extruder for melt blending, extrusion and granulation to obtain pellets for the outer layer of the film; mixing polypropylene and antioxidant in a high-speed mixer, and then placing them in a twin-screw extruder for melt blending, extrusion and granulation to obtain pellets for the inner layer of the film; S5: adding the pellets for the outer layer of the film and the pellets for the inner layer of the film into two screw extruders for melting, and extruding the two layers of melt through a die to form a cast film, which is then shaped, cooled, and rolled to obtain the antistatic polypropylene material.

2. The method for preparing the antistatic polypropylene material according to claim 1, characterized in that: In step S1, the deep-sea fish oil is one of tuna oil, salmon oil, cod oil, sardine oil, and mackerel oil, or a mixture of two or more of them in any proportion.

3. The method for preparing the antistatic polypropylene material according to claim 1, characterized in that: In step S2, the average molecular weight of the polyethylene glycol is 400-600.

4. The method for preparing the antistatic polypropylene material according to claim 1, characterized in that: In step S2, the catalyst is a sodium bisulfate aqueous solution, the mass fraction of the sodium bisulfate aqueous solution is 30-40%, and the amount of the sodium bisulfate aqueous solution is 1.5-2% of the mass of the oxidized deep-sea fish oil; During the reaction, the water in the sodium bisulfate aqueous solution and the water produced by the reaction are condensed in a condenser and then discharged.

5. The method for preparing the antistatic polypropylene material according to claim 1, characterized in that: In step S1 and step S2, the mass fraction of the sodium chloride solution is 2-3%.

6. The method for preparing an antistatic polypropylene material according to any one of claims 1 to 5, characterized in that: In step S3, the concentration of nano-tourmaline powder in the nano-tourmaline powder ethanol dispersion is 30-60 mg / mL; the preparation method of the nano-tourmaline powder ethanol dispersion comprises the following steps: adding nano-tourmaline powder with a particle size of 50-200 nm to anhydrous ethanol, and ultrasonically dispersing for 2-5 hours while stirring to obtain the nano-tourmaline powder.

7. The method for preparing an antistatic polypropylene material according to any one of claims 1 to 5, characterized in that: In step S3, the mass volume ratio of the modified fish oil to the nano-tourmaline powder ethanol dispersion is 1 g: 3-5 mL.

8. The method for preparing an antistatic polypropylene material according to any one of claims 1 to 5, characterized in that: In step S4, the material particles for the outer layer of the film include the following raw materials in weight percentage: 2.2-3.5% of nano-tourmaline powder / modified fish oil compound, 0.2-0.3% of antioxidant, and the balance of polypropylene; The material particles for the inner layer of the film include the following raw materials in weight percentage: 0.05-0.1% antioxidant and the balance polypropylene.

9. The method for preparing an antistatic polypropylene material according to any one of claims 1 to 5, characterized in that: In step S4, when preparing the pellets for the outer layer of the film and the pellets for the inner layer of the film, the temperature of the twin-screw extruder is 170-195°C, and the temperatures of zones one to ten are: 170°C, 170°C, 175°C, 180°C, 185°C, 190°C, 190°C, 185°C, 180°C, 180°C, and the head temperature is 195°C.

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