A production method of high-performance recyclable bopp film

Abstract

The application discloses a production method of high-performance recyclable BOPP film, and the high-performance recyclable BOPP film comprises an outer layer, a middle layer and an inner layer; the outer layer is composed of homopolymer polypropylene, polylactic acid, polyhydroxybutyrate, polypropylene carbonate, polystyrene-acrylonitrile copolymer, an antioxidant, an ultraviolet absorber and a slip agent; the middle layer is composed of homopolymer polypropylene, thermoplastic starch, polycaprolactone, polyethylene terephthalate, maleic anhydride grafted polypropylene, a fiber reinforcing agent and methyl methacrylate-butadiene-styrene copolymer; and the inner layer is composed of random copolymer polypropylene, polybutylene succinate, polyvinyl alcohol, PA6, an antistatic agent and an antibacterial agent. The BOPP film prepared by the method has good performance, is environment-friendly and recyclable.

Description

Technical Field

[0001] This invention relates to the field of BOPP film technology, specifically a method for producing high-performance recyclable BOPP film. Background Technology

[0002] BOPP film is generally recyclable. BOPP is a thermoplastic and inherently recyclable. Recycled BOPP film can be processed and remanufactured to produce plastic products or be used in other industrial applications. However, the feasibility and efficiency of BOPP film recycling can be affected by factors such as film aging, degree of contamination, thickness, and the type and content of additives. Aging BOPP film may require more energy and time for crushing, separation, and purification during recycling, reducing recycling efficiency and increasing costs. Furthermore, aged BOPP film may no longer meet the physical and chemical properties required for certain applications. The environmental impact of the material itself must also be considered when recycling BOPP film, as improper handling during recycling can lead to secondary pollution and adverse environmental effects. Summary of the Invention

[0003] In view of the above-mentioned deficiencies of the prior art, the object of the present invention is to provide a method for producing high-performance recyclable BOPP film.

[0004] To solve the above problems, the technical solution of the present invention is: a method for producing a high-performance recyclable BOPP film, wherein the high-performance recyclable BOPP film includes an outer layer, a middle layer and an inner layer; The outer layer is composed of homopolymer polypropylene, polylactic acid, polyhydroxybutyrate, polypropylene carbonate, polystyrene-acrylonitrile copolymer, antioxidant, ultraviolet absorber, and slip agent; The intermediate layer is composed of homopolymer polypropylene, thermoplastic starch, polycaprolactone, polyethylene terephthalate, maleic anhydride-grafted polypropylene, fiber reinforcing agent, and methyl methacrylate-butadiene-styrene copolymer. The inner layer is composed of random copolymer polypropylene, polybutylene succinate, polyvinyl alcohol, PA6, antistatic agent, and antibacterial agent; The production method includes the following steps: (1) The outer layer, middle layer and inner layer raw materials are blended separately and then sent to their respective extruders for melt mixing and plasticizing; (2) The molten melt is fed into the die head separately. After the melt merges in the die head, it forms a molten sheet through the flat die head opening. (3) The sheet is attached to the cooling roller with an air knife and rapidly cooled to form an unshaped sheet. Then, after cooling in a water bath, the sheet is shaped to form a cast sheet. (4) The cast sheet is stretched to form a thin film; (5) Coating the outer surface with an acrylate monomer-modified waterborne chlorinated polypropylene resin coating; (6) Wind up the film.

[0005] Furthermore, the outer layer consists of the following components by mass ratio: 50% homopolymer polypropylene, 15% polylactic acid, 10% polyhydroxybutyrate, 10% polypropylene carbonate, 8% polystyrene-acrylonitrile copolymer, 2% antioxidant, 2% UV absorber, and 3% slip agent.

[0006] Furthermore, the components of the intermediate layer are as follows by mass ratio: 55% homopolymer polypropylene, 15% thermoplastic starch, 10% polycaprolactone, 10% polyethylene terephthalate, 5% maleic anhydride-grafted polypropylene, 3% fiber reinforcing agent, and 2% methyl methacrylate-butadiene-styrene copolymer.

[0007] Furthermore, the fiber reinforcing agent is carbon fiber.

[0008] Furthermore, the components of the inner layer are as follows by mass: random copolymer polypropylene 55%, polybutylene succinate 18%, polyvinyl alcohol 12%, PA6 10%, antistatic agent 3%, and antibacterial agent 2%.

[0009] The beneficial effects of this invention are: The outer layer of multiple polymers works together to provide strength, toughness, barrier properties, and a good appearance. The middle layer of homopolymer polypropylene serves as the main component, combined with other polymers and additives to achieve a balance of strength, flexibility, and compatibility. The inner layer of random copolymer polypropylene works synergistically with other polymers to provide flexibility, barrier properties, abrasion resistance, and antibacterial functions, meeting the requirements for internal contact. The cooperation between the layers enables the film to achieve good comprehensive effects in terms of mechanical properties, barrier properties, recyclability, and functionality. The high strength and barrier properties of the outer layer provide external protection for the intermediate layer, reducing the impact of external factors on it. The high strength and good compatibility of the intermediate layer ensure the stability of the overall structure, while its flexibility can mitigate potential impacts and deformations to the outer layer. The strength and stability of the intermediate layer support the inner layer, enabling it to perform its functions better. The flexibility and multiple functions (such as barrier, antistatic, and antibacterial properties) of the inner layer work together with the intermediate layer to meet the comprehensive application requirements of the film. The surface properties of the outer layer (such as smoothness and abrasion resistance) provide favorable conditions for the inner layer to contact with the outside world. The barrier and antibacterial functions of the inner layer are protected to a certain extent by the outer layer, thus allowing them to function more effectively. The outer surface is coated with an acrylate monomer-modified waterborne chlorinated polypropylene resin coating, which has good hot water resistance, excellent chemical resistance and weather resistance. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the structure of the recyclable BOPP film of the present invention.

[0011] As shown in the diagram: 100—outer layer, 200—middle layer, 300—inner layer. Detailed Implementation

[0012] To provide a more intuitive and complete understanding of the technical solution of this invention, the following non-limiting features are described: A method for producing a high-performance recyclable BOPP film, the high-performance recyclable BOPP film comprising an outer layer 100, a middle layer 200 and an inner layer 300; The outer layer 100 is composed of homopolymer polypropylene, polylactic acid, polyhydroxybutyrate, polypropylene carbonate, polystyrene-acrylonitrile copolymer, antioxidant, ultraviolet absorber, and slip agent. The antioxidant is antioxidant 1010, the ultraviolet absorber is ultraviolet absorber UV-531, and the slip agent is silicone oil. The intermediate layer 200 is composed of homopolymer polypropylene, thermoplastic starch, polycaprolactone, polyethylene terephthalate, maleic anhydride-grafted polypropylene, fiber reinforcing agent, and methyl methacrylate-butadiene-styrene copolymer. The inner layer 300 is composed of random copolymer polypropylene, polybutylene succinate, polyvinyl alcohol, PA6, antistatic agent, and antibacterial agent. The antistatic agent is a polyether type antistatic agent, and the antibacterial agent is a nano silver particle antibacterial agent. The production method of high-performance recyclable BOPP film includes the following steps: (1) The outer layer, middle layer and inner layer raw materials are blended separately and then sent to their respective extruders for melt mixing and plasticizing; (2) The molten melt is fed into the die head separately. After the melt merges in the die head, it forms a molten sheet through the flat die head opening. (3) The sheet is attached to the cooling roller with an air knife and rapidly cooled to form an unshaped sheet. Then, after cooling in a water bath, the sheet is shaped to form a cast sheet. (4) The cast sheet is stretched to form a thin film; (5) Coating the outer surface with an acrylate monomer-modified waterborne chlorinated polypropylene resin coating; (6) Wind up the film.

[0013] The outer layer consists of the following components by mass ratio: 50% homopolymer polypropylene, 15% polylactic acid, 10% polyhydroxybutyrate, 10% polypropylene carbonate, 8% polystyrene-acrylonitrile copolymer, 2% antioxidant, 2% UV absorber, and 3% slip agent.

[0014] The components of the intermediate layer are as follows by mass ratio: 55% homopolymer polypropylene, 15% thermoplastic starch, 10% polycaprolactone, 10% polyethylene terephthalate, 5% maleic anhydride-grafted polypropylene, 3% fiber reinforcing agent, and 2% methyl methacrylate-butadiene-styrene copolymer.

[0015] The fiber reinforcing agent is carbon fiber, which is used to improve the strength and rigidity of the film. It works with other components to withstand external forces, increasing the load-bearing capacity of the interlayer. It reinforces the weaker parts of the base material, such as homopolymer polypropylene, giving the interlayer higher strength. Adding a small amount of carbon fiber can, to some extent, reduce the impact on the recyclability of BOPP film.

[0016] The components of the inner layer are as follows by mass ratio: random copolymer polypropylene 55%, polybutylene succinate 18%, polyvinyl alcohol 12%, PA6 10%, antistatic agent 3%, and antibacterial agent 2%.

[0017] The outer layer of homopolymer polypropylene has high strength and rigidity, providing basic mechanical support. Polylactic acid is a biodegradable material that increases the film's environmental performance and improves its flexibility. Polyhydroxybutyrate has good biocompatibility and degradability, contributing to the film's environmental characteristics. Polypropylene carbonate has good gas barrier properties, enhancing the film's ability to block external gases. Polystyrene-acrylonitrile copolymer improves the film's surface hardness and gloss, making it more aesthetically pleasing and wear-resistant. Antioxidant 1010 effectively prevents oxidative aging during use, extending its service life. UV absorber UV-531 reduces UV damage to the film's performance, maintaining stable performance. Silicone oil, a slip agent, reduces the coefficient of friction on the film surface, making it smoother during processing and use.

[0018] The outer layer, composed primarily of homopolymer polypropylene, provides fundamental strength and structural stability. Polylactic acid (PLA) and polyhydroxybutyrate (PHB) work together with the homopolymer polypropylene to increase the material's flexibility and processability while maintaining a certain level of strength. This makes the outer layer less prone to cracking under external forces. PLA and PHB compensate for the relatively low flexibility of homopolymer polypropylene, and their biodegradable properties enhance the overall environmental performance of the outer layer. Antioxidant 1010 and UV absorber UV-531 work together to prevent aging and performance degradation of the outer layer due to oxidation and UV radiation during use, synergistically maintaining the long-term stability of the outer layer along with other components.

[0019] The homopolymer polypropylene in the intermediate layer provides basic strength and stability, while the thermoplastic starch is biodegradable, increasing the film's environmental friendliness. Polycaprolactone provides good flexibility and processability, polyethylene terephthalate is used to improve mechanical strength and dimensional stability, maleic anhydride-grafted polypropylene is used to improve the compatibility between components, making the intermediate layer's performance more uniform and stable, and methyl methacrylate-butadiene-styrene copolymer acts as a toughening agent, increasing the film's toughness and impact resistance, making it less prone to breakage under external forces.

[0020] The homopolymer polypropylene (HPP) of the intermediate layer serves as the main component, providing basic structural support and stability. Thermoplastic starch and polycaprolactone (PCL) work synergistically with HPP to improve the flexibility and biodegradability of the intermediate layer, jointly adapting to external stresses during processing and use. Thermoplastic starch and PCL compensate for the shortcomings of HPP in terms of flexibility and environmental performance, making the intermediate layer more environmentally friendly. Polyethylene terephthalate (PET) supplements the deficiencies of HPP, thermoplastic starch, and PCL in terms of strength and dimensional stability. Methyl methacrylate (MDMA)-butadiene-styrene copolymer overcomes the increased brittleness that carbon fiber reinforcement can easily cause, enabling the intermediate layer to maintain high strength while possessing good toughness.

[0021] The inner layer of random copolymer polypropylene has good flexibility, allowing it to better adapt to the needs of internal contact. Polybutylene succinate is biodegradable and has good mechanical properties. Polyvinyl alcohol has good water solubility and barrier properties, effectively preventing the exchange of internal substances with the outside world. PA6 is used to increase the wear resistance and chemical resistance of the inner layer, improving the service life of the film. Antistatic agents are used to reduce static electricity accumulation and avoid the adverse effects of static electricity on the use of the film. Antibacterial agents give the film antibacterial properties, effectively inhibiting bacterial growth.

[0022] The inner layer of random copolymer polypropylene provides a certain degree of flexibility and basic properties. Polybutylene succinate works together with random copolymer polypropylene to enhance the mechanical properties and biodegradability of the inner layer, making the inner layer stronger while maintaining flexibility. Polybutylene succinate makes up for the shortcomings of random copolymer polypropylene in terms of biodegradability and some mechanical properties, providing better overall performance for the inner layer.

[0023] The outer layer of multiple polymers works together to provide strength, toughness, barrier properties, and a good appearance. The middle layer of homopolymer polypropylene serves as the main component, combined with other polymers and additives to achieve a balance of strength, flexibility, and compatibility. The inner layer of random copolymer polypropylene works synergistically with other polymers to provide flexibility, barrier properties, abrasion resistance, and antibacterial functions, meeting the requirements for internal contact. The cooperation between the layers enables the film to achieve good comprehensive effects in terms of mechanical properties, barrier properties, recyclability, and functionality. The high strength and barrier properties of the outer layer provide external protection for the intermediate layer, reducing the impact of external factors on it. The high strength and good compatibility of the intermediate layer ensure the stability of the overall structure, while its flexibility can mitigate potential impacts and deformations to the outer layer. The strength and stability of the intermediate layer support the inner layer, enabling it to perform its functions better. The flexibility and multiple functions (such as barrier, antistatic, and antibacterial properties) of the inner layer work together with the intermediate layer to meet the comprehensive application requirements of the film. The surface properties of the outer layer (such as smoothness and abrasion resistance) provide favorable conditions for the inner layer to contact with the outside world. The barrier and antibacterial functions of the inner layer are protected to a certain extent by the outer layer, thus allowing them to function more effectively. The outer surface is coated with an acrylate monomer-modified waterborne chlorinated polypropylene resin coating, which has good hot water resistance, excellent chemical resistance and weather resistance.

Claims

1. A method for producing a high-performance recyclable BOPP film, characterized in that: High-performance recyclable BOPP film consists of an outer layer, a middle layer, and an inner layer; The outer layer is composed of homopolymer polypropylene, polylactic acid, polyhydroxybutyrate, polypropylene carbonate, polystyrene-acrylonitrile copolymer, antioxidant, ultraviolet absorber, and slip agent; The intermediate layer is composed of homopolymer polypropylene, thermoplastic starch, polycaprolactone, polyethylene terephthalate, maleic anhydride-grafted polypropylene, fiber reinforcing agent, and methyl methacrylate-butadiene-styrene copolymer. The inner layer is composed of random copolymer polypropylene, polybutylene succinate, polyvinyl alcohol, PA6, antistatic agent, and antibacterial agent; The production method includes the following steps: (1) The outer layer, middle layer and inner layer raw materials are blended separately and then sent to their respective extruders for melt mixing and plasticizing; (2) The molten melt is fed into the die head separately. After the melt merges in the die head, it forms a molten sheet through the flat die head opening. (3) The sheet is attached to the cooling roller with an air knife and rapidly cooled to form an unshaped sheet. Then, after cooling in a water bath, the sheet is shaped to form a cast sheet. (4) The cast sheet is stretched to form a thin film; (5) Coating the outer surface with an acrylate monomer-modified waterborne chlorinated polypropylene resin coating; (6) Wind up the film.

2. The method for producing a high-performance recyclable BOPP film according to claim 1, characterized in that: The outer layer consists of the following components by mass ratio: 50% homopolymer polypropylene, 15% polylactic acid, 10% polyhydroxybutyrate, 10% polypropylene carbonate, 8% polystyrene-acrylonitrile copolymer, 2% antioxidant, 2% UV absorber, and 3% slip agent.

3. The method for producing a high-performance recyclable BOPP film according to claim 1, characterized in that: The components of the intermediate layer are as follows by mass ratio: 55% homopolymer polypropylene, 15% thermoplastic starch, 10% polycaprolactone, 10% polyethylene terephthalate, 5% maleic anhydride-grafted polypropylene, 3% fiber reinforcing agent, and 2% methyl methacrylate-butadiene-styrene copolymer.

4. The method for producing a high-performance recyclable BOPP film according to claim 1, characterized in that: The fiber reinforcing agent is carbon fiber.

5. A method for producing a high-performance recyclable BOPP film according to claim 1, characterized in that: The components of the inner layer are as follows by mass ratio: random copolymer polypropylene 55%, polybutylene succinate 18%, polyvinyl alcohol 12%, PA6 10%, antistatic agent 3%, and antibacterial agent 2%.

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