Antistatic agent for polyolefin film material production and preparation method thereof

Abstract

The invention discloses an antistatic agent for polyolefin film material production and a preparation method thereof. According to the invention, through reasonable molecular structure design, raw material selection and synthesis process optimization, the antistatic agent has multiple functions of high-efficiency antistatic property, oxidation resistance, antibacterial property, mechanical property enhancement and the like. The polyolefin material added with the multifunctional antistatic agent has good antistatic performance under different environmental conditions, and the oxidation resistance, the antibacterial property and the mechanical property are also remarkably improved. The antistatic agent has good adaptability with processing of a polyolefin film material and has wide application prospects and market competitive advantages, and the comprehensive performance of the polyolefin film material is remarkably improved through multi-component collaborative design. The composite system of the polyolefin quaternary ammonium salt and the graphene quantum dots strengthens the long-term effect of the antistatic effect, and meanwhile, the synergistic effect of the hindered phenol and the phosphite strengthens the antioxidant stability of the material in the processing and using processes.

Description

Technical Field

[0001] The invention belongs to the technical field of polyolefin films, and in particular relates to an antistatic agent for the production of polyolefin film materials and a preparation method thereof. Background Art

[0002] Polyolefin resin film materials have high inherent resistivity, making them prone to static electricity accumulation during processing and use. This static electricity not only attracts dust, affecting the appearance and quality of finished products, but can also trigger electrostatic discharge, damaging electronic components and even causing serious safety hazards such as fires and explosions in flammable and explosive environments. Therefore, the addition of antistatic agents to the polyolefin film processing and production process has become a key means of addressing static electricity issues. As the industry evolves, traditional antistatic agents are no longer sufficient for complex application scenarios, necessitating the development of multifunctional antistatic agents.

[0003] However, the molecular structure of the polyolefin film resin in the prior art lacks polar groups, resulting in a surface resistance as high as 10 12 -10 16 Ω is a typical insulating material. During the production process, friction between the resin and the equipment, as well as the flow of the resin itself, generates significant static electricity. During plastic film production, friction between high-speed rollers and the film can cause static voltages on the film surface to reach thousands or even tens of thousands of volts. During use, static electricity attracts dust, reducing the transparency of packaging materials and affecting product display. For products such as electronic and electrical housings, static discharge can disrupt the normal operation of electronic equipment and shorten its lifespan. Summary of the Invention

[0004] The purpose of the present invention is to provide an antistatic agent for polyolefin film production and a preparation method thereof in order to solve the above-mentioned problems.

[0005] The technical solution adopted by the present invention is as follows: an antistatic agent for the production of polyolefin film materials, comprising: 1.5 parts by weight of a polyolefin quaternary ammonium salt-graphene quantum dot composite antistatic agent, a hindered phenol-phosphite synergistic antioxidant system (0.6 parts by weight of bisphenol A type hindered phenol + 0.3 parts by weight of cyclic phosphite), 0.8 parts by weight of a nano zinc oxide-chitosan grafted antibacterial agent, 2.2 parts by weight of a maleic anhydride grafted polyolefin elastomer toughening agent, 1.0 parts by weight of a montmorillonite-carbon nanotube composite reinforcing agent, 0.4 parts by weight of a polyetheramine segment modified compatibilizer, 0.3 parts by weight of an organic silicone surface regulator, and 0.2 parts by weight of a bio-based limonene derivative.

[0006] In a preferred embodiment, a method for preparing an antistatic agent for polyolefin film production comprises the following steps:

[0007] S1: Accurately weigh the polyolefin quaternary ammonium salt-graphene quantum dot composite antistatic agent, bisphenol A type hindered phenol, and cyclic phosphite, and place the above raw materials in a vacuum drying oven at 80°C for 4 hours to remove moisture to avoid the generation of bubbles during the subsequent mixing process.

[0008] S2: Take the nano zinc oxide-chitosan grafted antibacterial agent, add it to a high-speed disperser, and pre-disperse it at 2000 rpm for 10 minutes. Then, slowly add the dried bisphenol A type hindered phenol in S1 into the disperser and continue to disperse for 15 minutes to form an antibacterial-antioxidant premix.

[0009] S3: Weigh maleic anhydride grafted polyolefin elastomer toughening agent and montmorillonite-carbon nanotube composite reinforcing agent, add them to the main feeding port of the twin-screw extruder, set the screw speed to 300 rpm and the first zone temperature to 160°C, melt and plasticize to obtain a basic resin matrix.

[0010] S4: The antibacterial-antioxidant premix prepared in S2 was added to the twin-screw extruder of S3 through a side feeding device, the feeding rate and the main feeding ratio were controlled to be 1:5, and the blending reaction was carried out at a temperature of 170°C in the second zone, and the reaction time was controlled to be 3 minutes.

[0011] S5: Take a polyetheramine segment modification compatibilizer and an organosiloxane surface conditioner, mix them, and add them to a high-speed mixer. Stir at 1500 rpm for 5 minutes. Then, cut the blend extruded in S4 into pellets and add them to the mixer. Continue stirring for 10 minutes to achieve surface modification.

[0012] S6: The modified particles obtained in S5 were added to a planetary ball mill, with agate balls as the grinding medium, a ball-to-material ratio of 8:1, a rotation speed of 400 rpm, and ball milling for 2 hours to refine the particle size to D50 ≤ 5 μm to improve subsequent dispersion uniformity.

[0013] S7: Weigh the bio-based limonene derivative and dissolve it in anhydrous ethanol to prepare a 5% solution. Then add the ball-milled particles in S6 into a fluidized bed coater and spray the limonene derivative solution evenly on the surface of the particles using a top spray method. Control the inlet air temperature at 60°C to achieve coating of the active ingredient.

[0014] S8: Place the coated particles in S7 into a twin-screw extruder, set the temperature of the three zones to 180° C. and the screw speed to 350 rpm, and extrude and granulate to obtain an antistatic agent masterbatch, thereby completing the preparation of the antistatic agent for the production of polyolefin film materials.

[0015] In a preferred embodiment, in step S1, 1.5 parts by weight of polyolefin quaternary ammonium salt-graphene quantum dot composite antistatic agent, 0.6 parts by weight of bisphenol A type hindered phenol, and 0.3 parts by weight of cyclic phosphite are accurately weighed, the above raw materials are respectively placed in a vacuum drying oven, the vacuum degree is set to -0.09 MPa, the temperature is set to 80°C, and the materials are dried for 4 hours, then naturally cooled to room temperature, and the humidity in the oven is recorded every hour during the period to ensure that the final material moisture content is not more than 0.05%, avoiding the problem of bubbles or degradation caused by water during subsequent processing.

[0016] In a preferred embodiment, in step S2, 0.8 parts by weight of nano zinc oxide-chitosan grafted antibacterial agent is added to a high-speed dispersing machine, the temperature of the dispersing cavity is adjusted to 45°C, and pre-dispersion is carried out at a speed of 2000 rpm for 10 minutes, then the dried bisphenol A type hindered phenol in S1 is slowly added to the dispersing machine at a rate of 5 g / min, and the ultrasonic auxiliary dispersion function is turned on at the same time, the power is set to 300 W and the frequency is set to 20 kHz, and dispersion is continued for 15 minutes, real-time monitoring is carried out through a laser particle size analyzer to ensure that the particle size distribution D90 of the system is not more than 2 μm, and a uniform antibacterial-antioxidant premix is formed.

[0017] In a preferred embodiment, in step S3, 2.2 parts by weight of maleic anhydride grafted polyolefin elastomer toughening agent and 1.0 parts by weight of montmorillonite-carbon nanotube composite reinforcing agent are weighed, a loss-on-ignition feeder is used to add the materials to the main feeding port of a twin-screw extruder at a rate of 8 kg / h, the screw length-diameter ratio is set to 40:1, the temperature of zone 1 is set to 160°C, the temperature of zone 2 is set to 175°C, the temperature of zone 3 is set to 180°C, the die pressure is controlled at 12 MPa, and the melt flow rate is monitored through an online viscometer during the melt plasticization process to ensure that the value is stable at 15 g / 10 min and the test conditions are 230°C / 2.16 kg, and a basic resin matrix is obtained.

[0018] In a preferred embodiment, in step S4, the antibacterial-antioxidant premix prepared in S2 is added to the twin-screw extruder of S3 through a side feeding device, the side feeding screw speed is set to 80 rpm, the corresponding feeding rate is 1.6 kg / h, the ratio of side feeding to main feeding is 1:5, the temperature of zone 4 of the extruder is set to 170°C, and the temperature of zone 5 is set to 165°C, strong shear blending is carried out in the screw kneading block section, which accounts for 30% of the total length of the screw, the reaction time is 3 minutes, and low molecular volatile substances are removed through a vacuum system during the period, and the vacuum degree is set to -0.08 MPa.

[0019] In a preferred embodiment, in step S5, 0.4 parts by weight of a polyetheramine segment-modified compatibilizer and 0.3 parts by weight of an organosiloxane surface regulator are taken and premixed in a constant temperature mixing kettle at 50°C for 20 minutes. Then, the mixture is added to a high-speed mixer, the jacket temperature is set to 60°C and the speed is 1500 rpm. After stirring for 5 minutes, the mixture is added to the blended particles treated by the pelletizer in S4. The pelletizer controls the particle size to 3±0.2 mm. Stirring is continued for 10 minutes. The torque of the mixed system is monitored by a torque sensor and stabilized at 35±2 N·m, completing the surface modification.

[0020] In a preferred embodiment, in step S6, the modified particles obtained in S5 are added to a planetary ball mill, and φ10 mm and φ5 mm agate balls are mixed in a mass ratio of 3:2 as grinding media, the ball-to-material ratio is 8:1, the speed is set to 400 rpm, and the ball rotates in the opposite direction once every 30 minutes. The ball mill is stopped after 2 hours of ball milling, and large particles are removed by screening. The sieve used is 200 mesh to ensure that the sieve residue does not exceed 0.5% to obtain a refined powder.

[0021] In a preferred embodiment, in step S7, 0.2 parts by weight of the bio-based limonene derivative is weighed and dissolved in anhydrous ethanol to prepare a 5% solution. The powder after ball milling in S6 is added to the fluidized bed coating machine, and the material bed temperature is set to 45°C and the air inlet rate is 1.2m 3 / min, atomization pressure of 0.3MPa, use a top spray gun to spray the solution, the nozzle aperture is 0.8mm, the spraying rate is 2mL / min, and after completion, continue to blow dry for 30 minutes to reduce the moisture content of the particles to below 0.1%.

[0022] In a preferred embodiment, in step S8, the coated particles in S7 are added to a twin-screw extruder, the temperature of zone 1 is set to 170°C, zone 2 is 180°C, zone 3 is 185°C, and the head is 175°C. The screw speed is adjusted to 350 rpm, and the pelletizing is carried out by an underwater pelletizing system. The cutter speed is 2000 rpm and the cooling water temperature is 25°C to obtain an antistatic agent masterbatch with a particle size of 2.5±0.3 mm. After screening by a vibrating sieve, the mesh size of the sieve used is 3 mm, and the pellets are dried in a hot air circulation oven at 40°C for 2 hours. The final packaging is 25 kg / bag.

[0023] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0024] 1. In the present invention, through rational molecular structure design, raw material selection, and optimized synthesis process, the antistatic agent possesses multiple functions, including high-efficiency antistatic, antioxidant, antibacterial, and enhanced mechanical properties. Polyolefin materials to which this multifunctional antistatic agent is added exhibit excellent antistatic properties under various environmental conditions, and their antioxidant, antibacterial, and mechanical properties are significantly improved. This antistatic agent is well-suited for processing polyolefin film materials and has broad application prospects and market competitive advantages.

[0025] 2. In the present invention, the comprehensive performance of the polyolefin film material is significantly improved through multi-component collaborative design. The composite system of polyolefin quaternary ammonium salt and graphene quantum dots enhances the long-term antistatic effect, while the synergistic effect of hindered phenol and phosphite enhances the antioxidant stability of the material during processing and use. The introduction of nano-zinc oxide and chitosan grafted antibacterial agent gives the film material a long-lasting antibacterial function, while the combination of maleic anhydride grafted polyolefin elastomer and montmorillonite-carbon nanotube composite reinforcing agent effectively improves the toughness and mechanical strength of the material. The polyetheramine segment modified compatibilizer and organosiloxane surface regulator further optimize the dispersion uniformity of each functional component in the polyolefin matrix, reduce interface defects, and improve the surface finish and reliability of the film material.

[0026] 3. In the present invention, the synergistic effect of each functional component is fully utilized through step-by-step processing and precise process control. The vacuum drying and high-speed dispersion process avoids the influence of moisture and bubbles in the raw materials on product quality. The segmented temperature control and side feeding design during the twin-screw extrusion process realize the gradient incorporation and uniform distribution of functional components. The planetary ball milling and fluidized bed coating process improve the dispersibility and surface activity of the particles, and finally the particle size uniformity and performance stability of the antistatic agent masterbatch are guaranteed through secondary extrusion granulation. The introduction of bio-based limonene derivatives not only enhances the environmental properties of the product, but its synergistic effect with organosiloxanes further optimizes the processing fluidity and surface smoothness of the film material, providing process feasibility and performance guarantee for the large-scale production of polyolefin film materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the process principle of the present invention;

[0028] Figure 2 This is a comparison chart of experimental data in the present invention. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0030] Example:

[0031] Referring Figure 1-2 An antistatic agent for polyolefin film production, comprising: 1.5 parts by weight of polyolefin quaternary ammonium salt-graphene quantum dot composite antistatic agent, 0.6 parts by weight of hindered phenol-cyclic phosphite synergistic antioxidant system (0.6 parts by weight of bisphenol A type hindered phenol + 0.3 parts by weight of cyclic phosphite), 0.8 parts by weight of nano zinc oxide-chitosan grafted antibacterial agent, 2.2 parts by weight of maleic anhydride grafted polyolefin elastomer toughening agent, 1.0 parts by weight of montmorillonite-carbon nanotube composite reinforcing agent, 0.4 parts by weight of polyetheramine segment modified compatibilizer, 0.3 parts by weight of organosiloxane surface modifier, and 0.2 parts by weight of biobased limonene derivative.

[0032] A preparation method of an antistatic agent for polyolefin film production, comprising the following steps:

[0033] S1: accurately weigh the polyolefin quaternary ammonium salt-graphene quantum dot composite antistatic agent, bisphenol A type hindered phenol, and cyclic phosphite, and dry the above-mentioned raw materials in a vacuum drying oven at 80°C for 4 hours to remove water to avoid the generation of bubbles in the subsequent mixing process.

[0034] S2: take the nano zinc oxide-chitosan grafted antibacterial agent, add it to a high-speed disperser, and pre-disperse it at a speed of 2000 rpm for 10 minutes, then slowly add the dried bisphenol A type hindered phenol in S1 to the disperser and continue to disperse for 15 minutes to form an antibacterial-antioxidant premix.

[0035] S3: weigh the maleic anhydride grafted polyolefin elastomer toughening agent and the montmorillonite-carbon nanotube composite reinforcing agent, and add them to the main feeding port of the twin-screw extruder, set the screw speed to 300 rpm and the temperature in zone one to 160°C, and melt plasticize to obtain a base resin matrix.

[0036] S4: add the antibacterial-antioxidant premix prepared in S2 to the twin-screw extruder in S3 through a side feeding device, control the feeding rate and the main feeding ratio to be 1:5, and carry out blending reaction at a temperature of 170°C in zone two, and control the reaction time to be 3 minutes.

[0037] S5: take the polyetheramine segment modified compatibilizer and the organosiloxane surface modifier, mix them, then add them to a high-speed mixer and stir at a speed of 1500 rpm for 5 minutes, then add the extruded blend in S4 to the mixer and continue to stir for 10 minutes to achieve surface modification.

[0038] S6: add the modified particles obtained in S5 to a planetary ball mill, use agate balls as the grinding medium, set the ball-to-material ratio to 8:1 and the rotation speed to 400 rpm, and ball mill for 2 hours to refine the particle size to D50≤5 μm and improve the subsequent dispersion uniformity.

[0039] S7: Weigh the bio-based limonene derivative and dissolve it in anhydrous ethanol to prepare a 5% solution. Then add the ball-milled particles in S6 into a fluidized bed coater and spray the limonene derivative solution evenly on the surface of the particles using a top spray method. Control the inlet air temperature at 60°C to achieve coating of the active ingredient.

[0040] S8: Place the coated particles in S7 into a twin-screw extruder, set the temperature of the three zones to 180° C. and the screw speed to 350 rpm, and extrude and granulate to obtain an antistatic agent masterbatch, thereby completing the preparation of the antistatic agent for the production of polyolefin film materials.

[0041] In step S1, 1.5 parts by weight of a polyolefin quaternary ammonium salt-graphene quantum dot composite antistatic agent, 0.6 parts by weight of bisphenol A hindered phenol, and 0.3 parts by weight of a cyclic phosphite are accurately weighed, and the above raw materials are respectively placed in a vacuum drying oven, the vacuum degree is set to -0.09 MPa, the temperature is 80 ° C, and the oven is dried for 4 hours and then naturally cooled to room temperature. The humidity in the oven is recorded once an hour during this period to ensure that the moisture content of the final material does not exceed 0.05%, thereby avoiding bubbles or degradation problems caused by moisture in subsequent processing.

[0042] In step S2, 0.8 parts by weight of the nano zinc oxide-chitosan grafted antibacterial agent is added to a high-speed disperser, the dispersion chamber temperature is adjusted to 45° C., and the mixture is pre-dispersed at 2000 rpm for 10 minutes. Subsequently, the dried bisphenol A hindered phenol in S1 is slowly added to the disperser at a rate of 5 g / min. At the same time, the ultrasonic assisted dispersion function is turned on, the power is set to 300 W, and the frequency is set to 20 kHz. The dispersion is continued for 15 minutes, and the system is monitored in real time by a laser particle size analyzer to ensure that the particle size distribution D90 of the system does not exceed 2 μm to form a uniform antibacterial-antioxidant premix.

[0043] In step S3, 2.2 parts by weight of a maleic anhydride grafted polyolefin elastomer toughener and 1.0 parts by weight of a montmorillonite-carbon nanotube composite reinforcing agent are weighed and added to the main feed port of a twin-screw extruder at a rate of 8 kg / h using a loss-in-weight feeder. The screw aspect ratio is set to 40:1, the temperature of zone 1 is 160°C, the temperature of zone 2 is 175°C, and the temperature of zone 3 is 180°C. The head pressure is controlled at 12 MPa. During the melt plasticization process, the melt flow rate is monitored by an online viscometer to ensure that the value is stable at 15 g / 10 min and the test conditions are 230°C / 2.16 kg to obtain a basic resin matrix.

[0044] In step S4, the antibacterial-antioxidant premix prepared in S2 is added to the twin-screw extruder of S3 through a side feeding device, the side feeding screw speed is set to 80 rpm, the corresponding feeding rate is 1.6 kg / h, and the ratio with the main feed is maintained at 1:5. The temperature of the fourth zone of the extruder is controlled to 170°C and the temperature of the fifth zone is controlled to 165°C. Strong shear blending is performed in the screw kneading block section, which accounts for 30% of the total length of the screw. The reaction time is 3 minutes, during which low molecular volatiles are removed by a vacuum system, and the vacuum degree is set to -0.08 MPa.

[0045] In step S5, 0.4 parts by weight of a polyetheramine segment-modified compatibilizer and 0.3 parts by weight of an organosiloxane surface regulator were premixed in a constant temperature mixing kettle at 50°C for 20 minutes, and then added to a high-speed mixer. The jacket temperature was set to 60°C and the speed was set to 1500 rpm. After stirring for 5 minutes, the blended particles treated by the pelletizer in S4 were added. The pelletizer controlled the particle size to 3±0.2 mm. Stirring was continued for 10 minutes. The torque of the mixed system was monitored by a torque sensor and stabilized at 35±2 N·m, completing the surface modification.

[0046] In step S6, the modified particles obtained in S5 are added to a planetary ball mill, and φ10 mm and φ5 mm agate balls are mixed in a mass ratio of 3:2 as the grinding medium, the ball-to-material ratio is 8:1, the speed is set to 400 rpm, and the ball rotates in the opposite direction once every 30 minutes. The ball mill is stopped after 2 hours of ball milling, and large particles are removed by screening. The sieve used is 200 mesh to ensure that the sieve residue does not exceed 0.5% to obtain a refined powder.

[0047] In step S7, 0.2 parts by weight of the bio-based limonene derivative was weighed and dissolved in anhydrous ethanol to prepare a 5% solution. The powder after ball milling in S6 was added to the fluidized bed coating machine, and the material bed temperature was set to 45°C and the air inlet rate was 1.2m / s. 3 / min, atomization pressure of 0.3MPa, use a top spray gun to spray the solution, the nozzle aperture is 0.8mm, the spraying rate is 2mL / min, and after completion, continue to blow dry for 30 minutes to reduce the moisture content of the particles to below 0.1%.

[0048] In step S8, the coated particles in S7 are added to a twin-screw extruder, and the temperature of zone 1, zone 2, zone 3, and die head is set to 175°C. The screw speed is adjusted to 350 rpm, and the pelletizing is carried out by an underwater pelletizing system. The cutter speed is 2000 rpm and the cooling water temperature is 25°C to obtain an antistatic agent masterbatch with a particle size of 2.5 ± 0.3 mm. After screening by a vibrating sieve, the mesh size of the sieve used is 3 mm, and the pellets are dried in a hot air circulation oven at 40°C for 2 hours. The final packaging is 25 kg / bag.

[0049] Comparative Example:

[0050] The conventional antistatic agent preparation process is adopted, and the specific steps are as follows:

[0051] S1: directly mix 1.5 parts by weight of a polyolefin quaternary ammonium salt antistatic agent and 0.6 parts by weight of bisphenol A hindered phenol without adding graphene quantum dots and cyclic phosphite, and dry in an 80° C. air drying oven for 4 hours (without vacuum control).

[0052] S2: Omit the nano-zinc oxide-chitosan grafted antibacterial agent, and directly add the dried antistatic agent and hindered phenol into the high-speed disperser and disperse at 1500 rpm for 20 minutes (without ultrasonic assistance).

[0053] S3: Only 2.2 parts by weight of maleic anhydride grafted polyolefin elastomer toughening agent was added without adding montmorillonite-carbon nanotube composite reinforcing agent, and melt-plasticized through a single-screw extruder (rotating speed 200 rpm, temperature in zone 1 170° C.).

[0054] S4: The side feeding and blending reaction steps were omitted, and the dispersed material was directly mixed with the toughening agent in the extruder without performing the planetary ball milling and fluidized bed coating processes. Finally, the antistatic agent masterbatch was obtained by one-time extrusion granulation.

[0055] The experimental results are shown in Figure 2 ,

[0056] Data Description:

[0057] Conductive performance: Through the synergistic effect of graphene quantum dots and polyolefin quaternary ammonium salts, the surface resistivity and volume resistivity of the present invention are reduced by 4 orders of magnitude compared with the control example, the electrostatic decay time is shortened from undetectable to 0.28 seconds, and the friction voltage is reduced to 150V, indicating that the charge dissipation speed and antistatic stability are significantly improved.

[0058] Mechanical properties: The combination of montmorillonite-carbon nanotube composite reinforcement and maleic anhydride grafted elastomer increases tensile strength and impact strength by 48.4% and 61.5% respectively, solving the problem of reduced material toughness caused by traditional antistatic agents.

[0059] Environmental adaptability: Under 30% low humidity conditions, the surface resistance of the present invention remains stable at 5.8×10 8 Ω, while the resistance of the comparative example increased to 1.2×10 13 Ω; After 12 months of aging, the performance of the present invention decayed by less than 25%, while the comparative example lost 99% of its antistatic effect, reflecting the long-term advantage.

[0060] Safety and processing performance: The thermal decomposition temperature is increased to 300°C, meeting the requirements of high-temperature processing; the oxidation induction time is extended to 45.3 minutes, and the antioxidant capacity is doubled, avoiding the bubbles and odor problems caused by degradation during the extrusion process of the comparative example.

[0061] From the above we can know:

[0062] The present invention utilizes rational molecular structure design, raw material selection, and optimized synthesis process to achieve multiple functions, including high-efficiency antistatic, antioxidant, antibacterial, and enhanced mechanical properties. Polyolefin materials containing this multifunctional antistatic agent exhibit excellent antistatic properties under various environmental conditions, with significantly improved antioxidant, antibacterial, and mechanical properties. This antistatic agent exhibits excellent compatibility with polyolefin film processing and offers broad application prospects and market competitiveness.

[0063] In the present invention, the comprehensive performance of the polyolefin film material is significantly improved through multi-component collaborative design. The composite system of polyolefin quaternary ammonium salt and graphene quantum dots enhances the long-term antistatic effect, while the synergistic effect of hindered phenol and phosphite enhances the antioxidant stability of the material during processing and use. The introduction of nano-zinc oxide and chitosan grafted antibacterial agent gives the film material a long-lasting antibacterial function, while the combination of maleic anhydride grafted polyolefin elastomer and montmorillonite-carbon nanotube composite reinforcing agent effectively improves the toughness and mechanical strength of the material. The polyetheramine segment modified compatibilizer and organosiloxane surface regulator further optimize the dispersion uniformity of each functional component in the polyolefin matrix, reduce interface defects, and improve the surface finish and service reliability of the film material.

[0064] In the present invention, the synergistic effect of each functional component is ensured to be fully utilized through step-by-step processing and precise process control. The vacuum drying and high-speed dispersion process avoids the influence of moisture and bubbles in the raw materials on product quality. The segmented temperature control and side feeding design during the twin-screw extrusion process realize the gradient incorporation and uniform distribution of functional components. The planetary ball milling and fluidized bed coating process improve the dispersibility and surface activity of the particles, and finally the particle size uniformity and performance stability of the antistatic agent masterbatch are guaranteed through secondary extrusion granulation. The introduction of bio-based limonene derivatives not only enhances the environmental properties of the product, but its synergistic effect with organosiloxanes further optimizes the processing fluidity and surface smoothness of the film material, providing process feasibility and performance guarantee for the large-scale production of polyolefin film materials.

[0065] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprises" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also other elements that are not explicitly listed, or also includes elements that are inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device that includes the element.

[0066] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. An antistatic agent for polyolefin film production, characterized in that: include: 1.5 parts by weight of polyolefin quaternary ammonium salt-graphene quantum dot composite antistatic agent, hindered phenol-phosphite synergistic antioxidant system (0.6 parts by weight of bisphenol A hindered phenol + 0.3 parts by weight of cyclic phosphite), 0.8 parts by weight of nano zinc oxide-chitosan grafted antibacterial agent, 2.2 parts by weight of maleic anhydride grafted polyolefin elastomer toughening agent, 1.0 parts by weight of montmorillonite-carbon nanotube composite reinforcer, 0.4 parts by weight of polyetheramine segment modified compatibilizer, 0.3 parts by weight of organosiloxane surface regulator, and 0.2 parts by weight of bio-based limonene derivative.

2. A method for preparing an antistatic agent for polyolefin film production according to claim 1, characterized in that: The method comprises the following steps: S1: Accurately weigh the polyolefin quaternary ammonium salt-graphene quantum dot composite antistatic agent, bisphenol A type hindered phenol, and cyclic phosphite, and place the above raw materials in a vacuum drying oven at 80°C for 4 hours to remove moisture to avoid bubbles in the subsequent mixing process; S2: Take the nano zinc oxide-chitosan grafted antibacterial agent, add it to a high-speed disperser, and pre-disperse it at 2000 rpm for 10 minutes. Then, slowly add the dried bisphenol A hindered phenol in S1 to the disperser and continue to disperse it for 15 minutes to form an antibacterial-antioxidant premix; S3: Weigh maleic anhydride grafted polyolefin elastomer toughening agent and montmorillonite-carbon nanotube composite reinforcing agent, add them to the main feed port of a twin-screw extruder, set the screw speed to 300 rpm and the first zone temperature to 160° C., and perform melt plasticization to obtain a base resin matrix; S4: The antibacterial-antioxidant premix prepared in S2 is added to the twin-screw extruder of S3 through a side feeding device, the feeding rate and the main feeding ratio are controlled to be 1:5, and the blending reaction is carried out at a temperature of 170° C. in the second zone, and the reaction time is controlled to be 3 minutes; S5: Take a polyetheramine segment modification compatibilizer and an organosiloxane surface conditioner, mix them, add them to a high-speed mixer, and stir at 1500 rpm for 5 minutes. Then, cut the blend extruded in S4 into pellets and add them to the mixer. Continue stirring for 10 minutes to achieve surface modification; S6: adding the modified particles obtained in S5 to a planetary ball mill, using agate balls as the grinding medium, a ball-to-material ratio of 8:1, a rotation speed of 400 rpm, and ball milling for 2 hours to refine the particle size to D50 ≤ 5 μm to improve subsequent dispersion uniformity; S7: Weigh a bio-based limonene derivative and dissolve it in anhydrous ethanol to prepare a 5% solution. Then, add the ball-milled particles in S6 to a fluidized bed coater, and spray the limonene derivative solution evenly on the surface of the particles using a top spray method. The inlet air temperature is controlled at 60°C to achieve coating of the active ingredient. S8: Place the coated particles in S7 into a twin-screw extruder, set the temperature of the three zones to 180° C. and the screw speed to 350 rpm, and extrude and granulate to obtain an antistatic agent masterbatch, thereby completing the preparation of the antistatic agent for the production of polyolefin film materials.

3. The method for preparing an antistatic agent for polyolefin film production according to claim 2, wherein: In the step S1, 1.5 parts by weight of a polyolefin quaternary ammonium salt-graphene quantum dot composite antistatic agent, 0.6 parts by weight of bisphenol A hindered phenol, and 0.3 parts by weight of a cyclic phosphite are accurately weighed, and the above raw materials are placed in a vacuum drying oven respectively, and the vacuum degree is set to -0.09 MPa and the temperature is set to 80°C. After drying for 4 hours, the oven is naturally cooled to room temperature. During this period, the humidity in the oven is recorded once every hour to ensure that the moisture content of the final material does not exceed 0.05%, so as to avoid bubbles or degradation problems caused by moisture in subsequent processing.

4. The method for preparing an antistatic agent for polyolefin film production according to claim 2, wherein: In the step S2, 0.8 parts by weight of the nano zinc oxide-chitosan grafted antibacterial agent is added to a high-speed disperser, the dispersion chamber temperature is adjusted to 45° C., and pre-dispersed at a speed of 2000 rpm for 10 minutes. Subsequently, the dried bisphenol A hindered phenol in S1 is slowly added to the disperser at a rate of 5 g / min, and the ultrasonic assisted dispersion function is turned on at the same time, with the power set to 300 W and the frequency set to 20 kHz. The dispersion is continued for 15 minutes, and the system is monitored in real time by a laser particle size analyzer to ensure that the particle size distribution D90 of the system does not exceed 2 μm, thereby forming a uniform antibacterial-antioxidant premix.

5. The method for preparing an antistatic agent for polyolefin film production according to claim 2, wherein: In the step S3, 2.2 parts by weight of a maleic anhydride grafted polyolefin elastomer toughener and 1.0 parts by weight of a montmorillonite-carbon nanotube composite reinforcing agent are weighed and added to the main feed port of a twin-screw extruder at a rate of 8 kg / h using a loss-in-weight feeder. The screw aspect ratio is set to 40:1, the temperature of zone 1 is 160°C, the temperature of zone 2 is 175°C, and the temperature of zone 3 is 180°C. The head pressure is controlled at 12 MPa. During the melt plasticization process, the melt flow rate is monitored by an online viscometer to ensure that the value is stable at 15 g / 10 min and the test conditions are 230°C / 2.16 kg to obtain a basic resin matrix.

6. The method for preparing an antistatic agent for polyolefin film production according to claim 2, wherein: In the step S4, the antibacterial-antioxidant premix prepared in S2 is added to the twin-screw extruder of S3 through a side feeding device, the side feeding screw speed is set to 80 rpm, the corresponding feeding rate is 1.6 kg / h, and the ratio with the main feed is maintained at 1:

5. The temperature of the fourth zone of the extruder is controlled to 170°C and the temperature of the fifth zone is controlled to 165°C. Strong shear blending is performed in the screw kneading block section, which accounts for 30% of the total length of the screw. The reaction time is 3 minutes, during which low molecular volatiles are removed by a vacuum system, and the vacuum degree is set to -0.08 MPa.

7. The method for preparing an antistatic agent for polyolefin film production according to claim 2, wherein: In step S5, 0.4 parts by weight of a polyetheramine segment-modified compatibilizer and 0.3 parts by weight of an organosiloxane surface conditioner are premixed in a constant-temperature mixing kettle at 50° C. for 20 minutes, then added to a high-speed mixer, the jacket temperature is set to 60° C., the speed is set to 1500 rpm, and after stirring for 5 minutes, the blended particles treated by the pelletizer in S4 are added. The pelletizer controls the particle size to 3±0.2 mm. Stirring is continued for 10 minutes. The torque of the mixed system is monitored by a torque sensor to be stable at 35±2 N·m, completing the surface modification.

8. The method for preparing an antistatic agent for polyolefin film production according to claim 2, wherein: In step S6, the modified particles obtained in S5 are added to a planetary ball mill, and φ10 mm and φ5 mm agate balls are mixed in a mass ratio of 3:2 as the grinding medium, the ball-to-material ratio is 8:1, the speed is set to 400 rpm, and the ball rotates in the opposite direction once every 30 minutes. The ball mill is stopped after 2 hours of ball milling, and large particles are removed by screening. The sieve used is 200 mesh to ensure that the sieve residue does not exceed 0.5% to obtain a refined powder.

9. The method for preparing an antistatic agent for polyolefin film production according to claim 2, wherein: In step S7, 0.2 parts by weight of the bio-based limonene derivative was weighed and dissolved in anhydrous ethanol to prepare a 5% solution. The powder after ball milling in S6 was added to the fluidized bed coating machine, and the material bed temperature was set to 45°C and the air inlet rate was 1.2m / s. 3 / min, atomization pressure of 0.3MPa, use a top spray gun to spray the solution, the nozzle aperture is 0.8mm, the spraying rate is 2mL / min, and after completion, continue to blow dry for 30 minutes to reduce the moisture content of the particles to below 0.1%.

10. The method for preparing an antistatic agent for polyolefin film production according to claim 2, wherein: In the step S8, the coated particles in S7 are added to a twin-screw extruder, the temperature of zone 1 is set to 170°C, zone 2 is set to 180°C, zone 3 is set to 185°C, and the head is set to 175°C. The screw speed is adjusted to 350 rpm, and granulation is carried out using an underwater pelletizing system, the cutter speed is 2000 rpm, and the cooling water temperature is 25°C to obtain an antistatic agent masterbatch with a particle size of 2.5±0.3 mm. After screening with a vibrating screen, the mesh size of the screen used is 3 mm, and the particles are dried in a hot air circulation oven at 40°C for 2 hours. The final packaging is 25 kg / bag.

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