Manufacturing method of tear-resistant and temperature-resistant CPP film for electronic screen protection

Abstract

The invention discloses a manufacturing method of a tear-resistant and temperature-resistant CPP film for electronic screen protection, and relates to the technical field of CPP films for electronic screen protection, and the manufacturing method comprises the following steps: step 1, preparing raw materials, step 2, carrying out melt extrusion, step 3, stretching and shaping, step 4, carrying out surface coating, and step 5, cooling and coiling. The preparation raw materials comprise the following preparation materials in parts by weight: 50-60 parts of a polypropylene copolymer, 15-30 parts of a homopolymer, 18-28 parts of an antioxidant, 3-14 parts of an anti-ultraviolet agent, 3-7 parts of a temperature-resistant agent, 10-18 parts of an electrostatic agent, 2-8 parts of an anti-fogging agent, 6-12 parts of an anti-blocking agent and 4-9 parts of a slipping agent, the preparation materials are put into a melting machine and heated to 300-600 DEG C to be melted, the melted preparation materials are extruded through an extruder, and the polypropylene composite material is obtained. The method comprises the following steps of: coating a film with the width of 20-80cm and the thickness of 0.2-0.9 mm, coating the outer wall of the film with a surface coating which is polyurethane or polyvinyl chloride, and improving the tear resistance and temperature resistance of the film by using the surface coating.

Description

Technical Field

[0001] The invention relates to the technical field of CPP films for electronic screen savers, in particular to a method for preparing a tear-resistant and temperature-resistant CPP film for electronic screen savers. Background Art

[0002] CPP film is a polypropylene film produced by casting process, with good transparency, uniform thickness, and uniform performance in vertical and horizontal directions. Electronic screen protection has become an important demand. As one of the core components of electronic products, the surface of the electronic screen is easily damaged by scratches, pollution, etc., which affects the service life and appearance of the product. Therefore, an effective protective film is needed to protect the electronic screen from damage. However, the tensile strength and heat resistance of the existing CPP film for electronic screen protection are not high, which reduces the performance of the CPP film.

[0003] The defects of existing CPP films for electronic screen savers are: 1. Patent document CN109266232B discloses CPP base-free silent cold laminating film, "including: non-silicon coating, base film layer and glue layer, the non-silicon coating is coated on the front of the base film layer, the side of the non-silicon coating away from the front of the base film layer is convexly spaced in the lateral direction of the corresponding base film layer to form convex strips, the back of the base film layer is coated with water-based glue to form a glue layer, when used, the convex strips formed by the convexity can enhance the tension resistance of the base film layer, so that the base film layer is sealed smoothly when the non-silicon coating is coated, wrinkles are avoided, and the generation of bubbles is reduced, which can improve the efficiency of lamination. The convex strips form a texture, which can increase the three-dimensional sense of the cold laminating film of the present invention, and the bottom paper layer is eliminated, so that the problems of uneven bottom paper in the laminating process in the prior art, which easily lead to small bubbles in the film, easy edge shrinkage, easy wrinkles in the film, slow speed, and occupying inventory space, etc., are avoided. Therefore, the cold laminating film of the present invention is light, super transparent, more environmentally friendly and saves production costs. The water-based glue is used to make the cold laminating film safe, environmentally friendly, non-toxic and tasteless. However, the tensile strength and heat resistance of the existing CPP film for electronic screen savers are not high, which reduces the performance of the CPP film; 2. Patent document CN109228423B discloses a production and processing method of CPP film, "including: step 1, mixing: feeding the raw materials into a mixer for mixing; step 2, extrusion casting: the mixed raw materials are heated in an extruder to form a molten state and extruded and cast; step 3, pre-cooling: the extruded film enters a cooling box for pre-cooling, and the temperature in the cooling box is 25-35°C; step 4, cooling and forming: a cooling roller is provided in the cooling box, and the surface temperature of the cooling roller is 20-30°C; step 5, increasing Surface adhesion: Use a corona roller to treat the film surface; Step 6, Rolling and cutting: Rotate the winding roller to make the CPP film wind around the winding roller to form a winding film. When the film is rolled up, the cutters at both ends of the moving roller cut the film; Step 7, roll up the edge material. The present invention provides a production and processing method of a CPP film that is cut and rolled up at the same time, so as to improve the factory quality of the CPP film and reduce the probability of failure during the film rolling process. However, the tensile strength and heat resistance of the existing CPP film for electronic screen savers are not high, which reduces the performance of the CPP film; 3. Patent document CN109532172B discloses a CPP film, "including a corona layer, an intermediate layer and a heat-sealing layer, the weight ratios of the corona layer, the intermediate layer and the heat-sealing layer are 20%, 55% and 25% respectively, the corona layer is made of homopolymer polypropylene and an anti-adhesive agent, the intermediate layer is a homopolymer polypropylene resin containing a slip agent and an anti-adhesive agent, and the heat-sealing layer is made of metallocene ternary block copolymer polypropylene and a slip agent; it also discloses a CPP film production method, including the following steps: material preparation; stirring; extrusion plasticization; extrusion casting; cooling molding; traction; electric spark treatment; curling; aging treatment; slitting. This solution mainly solves the problem of poor transparency of CPP film and the problem of insufficient mixing of raw materials in the production of CPP film", but the tensile strength and heat resistance of the existing CPP film for electronic screen savers are not high, which reduces the performance of the CPP film; 4. Patent document CN109228423A discloses a production and processing method of CPP film, "including: step 1, mixing: feeding the raw materials into a mixer for mixing; step 2, extrusion casting: the mixed raw materials are heated in an extruder to form a molten state and extruded and cast; step 3, pre-cooling: the extruded film enters a cooling box for pre-cooling, and the temperature in the cooling box is 25-35°C; step 4, cooling and molding: a cooling roller is provided in the cooling box, and the surface temperature of the cooling roller is 20-30°C; step 5, increasing Surface adhesion: Use a corona roller to treat the film surface; Step 6, winding and cutting: Rotate the winding roller to make the CPP film wind around the winding roller to form a winding film. When the film is rolled up, the cutters at both ends of the moving roller cut the film; Step 7, winding the edge material. The present invention provides a production and processing method of a CPP film that is cut and rolled up at the same time, so as to improve the factory quality of the CPP film and reduce the probability of failure during the film rolling process. However, the tensile strength and heat resistance of the existing CPP film for electronic screen savers are not high, which reduces the performance of the CPP film. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing a tear-resistant and heat-resistant CPP film for electronic screen savers, so as to solve the technical problem that the tensile strength and heat resistance of the existing CPP film for electronic screen savers are not high, resulting in poor performance of the CPP film.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for preparing a tear-resistant and heat-resistant CPP film for electronic screen saver, comprising the following steps; Step 1, preparing raw materials; Step 2, melt extrusion; Step 3: stretching and shaping; Step 4, surface coating; Step 5, cooling and coiling; The preparation raw materials include the following parts by weight: 50-60 parts of polypropylene copolymer, 15-30 parts of homopolymer, 18-28 parts of antioxidant, 3-14 parts of anti-ultraviolet agent, 3-7 parts of heat-resistant agent, 10-18 parts of static agent, 2-8 parts of anti-fogging agent, 6-12 parts of anti-blocking agent, and 4-9 parts of lubricant. The preparation materials are put into a melting machine, heated to 300-600° C. to melt them, and the melted preparation materials are extruded through an extruder to form a film with a width of 20-80 cm and a thickness of 0.2-0.9 mm, and the outer wall of the film is coated with a surface coating.

[0006] Preferably, the surface coating is polyurethane or polyvinyl chloride, and the surface coating improves the tear resistance and temperature resistance of the film.

[0007] Preferably, the film is stretched by a stretching device to change its physical properties and improve its tensile strength, transparency and flatness. The degree and speed of stretching are adjusted according to the required film properties. The stretched film is shaped to ensure its dimensional stability and performance consistency.

[0008] Preferably, the film is rapidly cooled by a cooling device at a temperature of 10-20° C. to solidify its structure and maintain stability. The cooled film is cut into a suitable size by a cutting device and then wound into a roll by a winder.

[0009] Preferably, the cooling device is a combination of air cooling and water cooling.

[0010] Preferably, the heat resistant agent is one of nano-alumina, graphene, ammonium polyphosphate, triphenylphosphoric acid, manganese hydroxybenzoate, silica gel heat resistant agent, and plastic high temperature resistant agent.

[0011] Preferably, the surface of the film is subjected to corona treatment to improve the adhesion of the surface coating.

[0012] Preferably, the film is prepared by composite extrusion of raw materials with different formulations through multi-layer co-extrusion technology to form a CPP film with a multi-layer structure.

[0013] Preferably, the cooling rate during the composite extrusion process is controlled within 10 to 20 minutes to avoid stress inside the film.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention is provided with a preparation material including the following parts by weight: 52 parts of polypropylene copolymer, 18 parts of homopolymer, 21 parts of antioxidant, 4 parts of anti-ultraviolet agent, 3 parts of heat-resistant agent, 11 parts of electrostatic agent, 3 parts of anti-fogging agent, 7 parts of anti-blocking agent, and 5 parts of lubricant. The preparation material is put into a melting machine, heated to 300-600°C to melt it, and the melted preparation material is extruded by an extruder to form a film with a width of 30 cm and a thickness of 0.3 mm. The outer wall of the film is coated with a surface coating, which is polyurethane or polyvinyl chloride. The surface coating improves the tear resistance and temperature resistance of the film. The film is stretched by a stretching device to change its physical properties, improve tensile strength, transparency and flatness, and the degree and speed of stretching are adjusted according to the required film properties. The stretched film is subjected to a shaping treatment to ensure its dimensional stability and performance consistency. The film is rapidly cooled by a cooling device, and the cooling temperature is 10-20°C to solidify its structure and maintain stability. Therefore, it is explained that the tensile strength of the CPP film for electronic screen saver of the present invention is greatly improved to improve the product quality. 2. The present invention is provided with a preparation material comprising the following preparation materials in parts by weight: 54 parts of polypropylene copolymer, 20 parts of homopolymer, 21 parts of antioxidant, 5 parts of anti-ultraviolet agent, 4 parts of heat-resistant agent, 12 parts of static agent, 4 parts of anti-fogging agent, 7 parts of anti-blocking agent, and 5 parts of lubricant. The preparation materials are put into a melting machine, heated to 300-600° C. to melt them, and the melted preparation materials are extruded through an extruder to form a film with a width of 40 cm and a thickness of 0.3 mm. The outer wall of the film is coated with a surface coating, and the surface coating is polyurethane or polyvinyl chloride. The surface coating improves the tear resistance and temperature resistance of the film. The film is stretched by a stretching device to change its physical properties and improve its tensile strength, transparency and flatness. The degree and speed of stretching are adjusted according to the required film properties. The stretched film is subjected to a shaping treatment to ensure its dimensional stability and performance consistency. The film is quickly cooled by a cooling device at a cooling temperature of 10 to 20°C to solidify its structure and maintain stability. Therefore, it is shown that the heat resistance of the CPP film for electronic screen savers of the present invention is greatly improved, so that the product has a function of enhancing heat resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of test data of the present invention. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "two ends", "one end", "the other end" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0018] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, it can be understood according to the specific situation.

[0019] Embodiment 1: An embodiment provided by the present invention: A method for preparing a tear-resistant and heat-resistant CPP film for electronic screen saver, comprising the following steps; Step 1, preparing raw materials; Step 2, melt extrusion; Step 3: stretching and shaping; Step 4, surface coating; Step 5, cooling and coiling; The preparation raw materials include the following preparation materials in parts by weight: 52 parts of polypropylene copolymer, 18 parts of homopolymer, 21 parts of antioxidant, 4 parts of anti-ultraviolet agent, 3 parts of heat-resistant agent, 11 parts of electrostatic agent, 3 parts of anti-fogging agent, 7 parts of anti-blocking agent, and 5 parts of lubricant. The preparation materials are put into a melting machine, heated to 300-600°C to melt them, and the melted preparation materials are extruded through an extruder to form a film with a width of 30 cm and a thickness of 0.3 mm. The outer wall of the film is coated with a surface coating, which is polyurethane or polyvinyl chloride. The surface coating improves the tear resistance and temperature resistance of the film. The film is stretched by a stretching device to change its physical properties and improve tensile strength, transparency and flatness. The degree and speed of stretching are adjusted according to the required film properties. The stretched film is shaped to To ensure its dimensional stability and performance consistency, the film is quickly cooled by cooling equipment at a temperature of 10-20°C to solidify its structure and maintain stability. The cooled film is cut into a suitable size by a cutting device and then rolled into a roll by a winder. The cooling equipment is a combination of air cooling and water cooling. The heat-resistant agent is one of nano-alumina, graphene, ammonium polyphosphate, triphenylphosphoric acid, manganese hydroxybenzoate, silicone heat-resistant agent, and plastic high-temperature resistant agent. The surface of the film is corona treated to improve the adhesion of the surface coating. The film is extruded through multi-layer co-extrusion technology to compositely extrude raw materials of different formulations to form a CPP film with a multi-layer structure. The cooling rate during the composite extrusion process is controlled at 10-20 minutes to avoid stress inside the film.

[0020] Embodiment 2: An embodiment provided by the present invention: A method for preparing a tear-resistant and heat-resistant CPP film for electronic screen saver, comprising the following steps; Step 1, preparing raw materials; Step 2, melt extrusion; Step 3: stretching and shaping; Step 4, surface coating; Step 5, cooling and coiling; The preparation raw materials include the following preparation materials in parts by weight: 54 parts of polypropylene copolymer, 20 parts of homopolymer, 21 parts of antioxidant, 5 parts of anti-ultraviolet agent, 4 parts of heat-resistant agent, 12 parts of static agent, 4 parts of anti-fogging agent, 7 parts of anti-blocking agent, and 5 parts of lubricant. The preparation materials are put into a melting machine, heated to 300-600°C to melt them, and the melted preparation materials are extruded through an extruder to form a film with a width of 40 cm and a thickness of 0.3 mm. The outer wall of the film is coated with a surface coating, which is polyurethane or polyvinyl chloride. The surface coating improves the tear resistance and temperature resistance of the film. The film is stretched by a stretching device to change its physical properties and improve tensile strength, transparency and flatness. The degree and speed of stretching are adjusted according to the required film properties. The stretched film is shaped to To ensure its dimensional stability and performance consistency, the film is quickly cooled by cooling equipment at a temperature of 10-20°C to solidify its structure and maintain stability. The cooled film is cut into a suitable size by a cutting device and then rolled into a roll by a winder. The cooling equipment is a combination of air cooling and water cooling. The heat-resistant agent is one of nano-alumina, graphene, ammonium polyphosphate, triphenylphosphoric acid, manganese hydroxybenzoate, silicone heat-resistant agent, and plastic high-temperature resistant agent. The surface of the film is corona treated to improve the adhesion of the surface coating. The film is extruded through multi-layer co-extrusion technology to compositely extrude raw materials of different formulations to form a CPP film with a multi-layer structure. The cooling rate during the composite extrusion process is controlled at 10-20 minutes to avoid stress inside the film.

[0021] Embodiment 3: An embodiment provided by the present invention: A method for preparing a tear-resistant and heat-resistant CPP film for electronic screen saver, comprising the following steps; Step 1, preparing raw materials; Step 2, melt extrusion; Step 3: stretching and shaping; Step 4, surface coating; Step 5, cooling and coiling; The preparation raw materials include the following preparation materials in parts by weight: 56 parts of polypropylene copolymer, 24 parts of homopolymer, 22 parts of antioxidant, 8 parts of anti-ultraviolet agent, 5 parts of heat-resistant agent, 13 parts of static agent, 6 parts of anti-fogging agent, 5 parts of anti-blocking agent, and 7 parts of lubricant. The preparation materials are put into a melting machine, heated to 300-600°C to melt them, and the melted preparation materials are extruded through an extruder to form a film with a width of 50 cm and a thickness of 0.4 mm. The outer wall of the film is coated with a surface coating, which is polyurethane or polyvinyl chloride. The surface coating improves the tear resistance and temperature resistance of the film. The film is stretched by a stretching device to change its physical properties and improve tensile strength, transparency and flatness. The degree and speed of stretching are adjusted according to the required film properties. The stretched film is shaped to To ensure its dimensional stability and performance consistency, the film is quickly cooled by cooling equipment at a temperature of 10-20°C to solidify its structure and maintain stability. The cooled film is cut into a suitable size by a cutting device and then rolled into a roll by a winder. The cooling equipment is a combination of air cooling and water cooling. The heat-resistant agent is one of nano-alumina, graphene, ammonium polyphosphate, triphenylphosphoric acid, manganese hydroxybenzoate, silicone heat-resistant agent, and plastic high-temperature resistant agent. The surface of the film is corona treated to improve the adhesion of the surface coating. The film is extruded through multi-layer co-extrusion technology to compositely extrude raw materials of different formulations to form a CPP film with a multi-layer structure. The cooling rate during the composite extrusion process is controlled at 10-20 minutes to avoid stress inside the film.

[0022] Embodiment 4: An embodiment provided by the present invention: a method for preparing a tear-resistant and heat-resistant CPP film for electronic screen saver, comprising the following steps; Step 1, preparing raw materials; Step 2, melt extrusion; Step 3: stretching and shaping; Step 4, surface coating; Step 5, cooling and coiling; The preparation raw materials include the following preparation materials in parts by weight: 56 parts of polypropylene copolymer, 26 parts of homopolymer, 24 parts of antioxidant, 12 parts of anti-ultraviolet agent, 6 parts of heat-resistant agent, 15 parts of static agent, 7 parts of anti-fogging agent, 10 parts of anti-blocking agent, and 7 parts of lubricant. The preparation materials are put into a melting machine, heated to 300-600°C to melt them, and the melted preparation materials are extruded through an extruder to form a film with a width of 65 cm and a thickness of 0.5 mm. The outer wall of the film is coated with a surface coating, which is polyurethane or polyvinyl chloride. The surface coating improves the tear resistance and temperature resistance of the film. The film is stretched by a stretching device to change its physical properties and improve tensile strength, transparency and flatness. The degree and speed of stretching are adjusted according to the required film properties. The stretched film is subjected to a shaping treatment. To ensure its dimensional stability and performance consistency, the film is quickly cooled by a cooling device at a temperature of 10-20°C to solidify its structure and maintain stability. The cooled film is cut into a suitable size by a cutting device and then rolled into a roll by a winder. The cooling device is a combination of air cooling and water cooling. The heat-resistant agent is one of nano-alumina, graphene, ammonium polyphosphate, triphenylphosphoric acid, manganese hydroxybenzoate, silicone heat-resistant agent, and plastic high-temperature resistant agent. The film surface is corona treated to improve the adhesion of the surface coating. The film is extruded through a multi-layer co-extrusion technology to compositely extrude raw materials of different formulations to form a CPP film with a multi-layer structure. The cooling rate during the composite extrusion process is controlled at 10-20 minutes to avoid stress inside the film.

[0023] Embodiment 5: An embodiment provided by the present invention: A method for preparing a tear-resistant and heat-resistant CPP film for electronic screen saver, comprising the following steps; Step 1, preparing raw materials; Step 2, melt extrusion; Step 3: stretching and shaping; Step 4, surface coating; Step 5, cooling and coiling; The preparation raw materials include the following preparation materials in parts by weight: 60 parts of polypropylene copolymer, 28 parts of homopolymer, 26 parts of antioxidant, 13 parts of anti-ultraviolet agent, 6 parts of heat-resistant agent, 17 parts of static agent, 7 parts of anti-fogging agent, 11 parts of anti-blocking agent, and 9 parts of lubricant. The preparation materials are put into a melting machine, heated to 300-600°C to melt them, and the melted preparation materials are extruded through an extruder to form a film with a width of 75 cm and a thickness of 0.7 mm. The outer wall of the film is coated with a surface coating, which is polyurethane or polyvinyl chloride. The surface coating improves the tear resistance and temperature resistance of the film. The film is stretched by a stretching device to change its physical properties and improve tensile strength, transparency and flatness. The degree and speed of stretching are adjusted according to the required film properties. The stretched film is subjected to a shaping treatment. To ensure its dimensional stability and performance consistency, the film is quickly cooled by a cooling device at a temperature of 10-20°C to solidify its structure and maintain stability. The cooled film is cut into a suitable size by a cutting device and then rolled into a roll by a winder. The cooling device is a combination of air cooling and water cooling. The heat-resistant agent is one of nano-alumina, graphene, ammonium polyphosphate, triphenylphosphoric acid, manganese hydroxybenzoate, silicone heat-resistant agent, and plastic high-temperature resistant agent. The film surface is corona treated to improve the adhesion of the surface coating. The film is extruded through a multi-layer co-extrusion technology to compositely extrude raw materials of different formulations to form a CPP film with a multi-layer structure. The cooling rate during the composite extrusion process is controlled at 10-20 minutes to avoid stress inside the film.

[0024] Comparative experiment: The difference between Comparative Example 1 and Example 1 is that the preparation raw materials include the following preparation materials in parts by weight: 52 parts of polypropylene copolymer, 18 parts of homopolymer, 21 parts of antioxidant, 4 parts of anti-ultraviolet agent, 3 parts of heat-resistant agent, 11 parts of electrostatic agent, 3 parts of anti-fogging agent, 7 parts of anti-blocking agent, and 5 parts of lubricant. The preparation materials are put into a melting machine and heated to 300-600°C to melt them. The melted preparation materials are extruded by an extruder to form a film with a width of 30 cm and a thickness of 0.3 mm. The outer wall of the film is coated with a surface coating, which is polyurethane or polyvinyl chloride. The surface coating improves the tear resistance and temperature resistance of the film. The film is stretched by a stretching device to change its physical properties and improve tensile strength, transparency and flatness. The degree and speed of stretching are adjusted according to the required film properties. The stretched film is subjected to a shaping treatment to ensure its dimensional stability and performance consistency. The film is rapidly cooled by a cooling device at a cooling temperature of 10-20°C to solidify its structure and maintain stability.

[0025] The difference between Comparative Example 1 and Example 2 is that; The preparation raw materials include the following preparation materials in parts by weight: 54 parts of polypropylene copolymer, 20 parts of homopolymer, 21 parts of antioxidant, 5 parts of anti-ultraviolet agent, 4 parts of heat-resistant agent, 12 parts of electrostatic agent, 4 parts of anti-fogging agent, 7 parts of anti-blocking agent and 5 parts of lubricant. The preparation materials are put into a melting machine and heated to 300-600°C to melt them. The melted preparation materials are extruded through an extruder to form a film with a width of 40 cm and a thickness of 0.3 mm. The outer wall of the film is coated with a surface coating, which is polyurethane or polyvinyl chloride. The surface coating improves the tear resistance and temperature resistance of the film. The film is stretched by a stretching device to change its physical properties and improve its tensile strength, transparency and flatness. The degree and speed of stretching are adjusted according to the required film properties. The stretched film is subjected to a shaping treatment to ensure its dimensional stability and performance consistency. The film is quickly cooled by a cooling device, and the cooling temperature is 10-20°C to solidify its structure and maintain stability.

[0026] The difference between Comparative Example 1 and Example 3 is that; The preparation raw materials include the following preparation materials in parts by weight: 56 parts of polypropylene copolymer, 24 parts of homopolymer, 22 parts of antioxidant, 8 parts of anti-ultraviolet agent, 5 parts of heat-resistant agent, 13 parts of electrostatic agent, 6 parts of anti-fogging agent, 5 parts of anti-blocking agent and 7 parts of lubricant. The preparation materials are put into a melting machine and heated to 300-600°C to melt them. The melted preparation materials are extruded through an extruder to form a film with a width of 50 cm and a thickness of 0.4 mm. The outer wall of the film is coated with a surface coating, which is polyurethane or polyvinyl chloride. The surface coating improves the tear resistance and temperature resistance of the film. The film is stretched by a stretching device to change its physical properties and improve its tensile strength, transparency and flatness. The degree and speed of stretching are adjusted according to the required film properties. The stretched film is subjected to a shaping treatment to ensure its dimensional stability and performance consistency. The film is quickly cooled by a cooling device, and the cooling temperature is 10-20°C to solidify its structure and maintain stability.

[0027] The difference between Comparative Example 1 and Example 4 is that; The preparation raw materials include the following preparation materials in parts by weight: 56 parts of polypropylene copolymer, 26 parts of homopolymer, 24 parts of antioxidant, 12 parts of anti-ultraviolet agent, 6 parts of heat-resistant agent, 15 parts of electrostatic agent, 7 parts of anti-fogging agent, 10 parts of anti-blocking agent and 7 parts of lubricant. The preparation materials are put into a melting machine and heated to 300-600°C to melt them. The melted preparation materials are extruded through an extruder to form a film with a width of 65 cm and a thickness of 0.5 mm. The outer wall of the film is coated with a surface coating, which is polyurethane or polyvinyl chloride. The surface coating improves the tear resistance and temperature resistance of the film. The film is stretched by a stretching device to change its physical properties and improve its tensile strength, transparency and flatness. The degree and speed of stretching are adjusted according to the required film properties. The stretched film is subjected to a shaping treatment to ensure its dimensional stability and performance consistency. The film is quickly cooled by a cooling device, and the cooling temperature is 10-20°C to solidify its structure and maintain stability.

[0028] The difference between Comparative Example 1 and Example 5 is that; The preparation raw materials include the following preparation materials in parts by weight: 60 parts of polypropylene copolymer, 28 parts of homopolymer, 26 parts of antioxidant, 13 parts of anti-ultraviolet agent, 6 parts of heat-resistant agent, 17 parts of electrostatic agent, 7 parts of anti-fogging agent, 11 parts of anti-blocking agent and 9 parts of lubricant. The preparation materials are put into a melting machine and heated to 300-600°C to melt them. The melted preparation materials are extruded through an extruder to form a film with a width of 75 cm and a thickness of 0.7 mm. The outer wall of the film is coated with a surface coating, which is polyurethane or polyvinyl chloride. The surface coating improves the tear resistance and temperature resistance of the film. The film is stretched by a stretching device to change its physical properties and improve its tensile strength, transparency and flatness. The degree and speed of stretching are adjusted according to the required film properties. The stretched film is subjected to a shaping treatment to ensure its dimensional stability and performance consistency. The film is quickly cooled by a cooling device, and the cooling temperature is 10-20°C to solidify its structure and maintain stability.

[0029] The CPP films for electronic screen savers of Examples 1, 2, 3, 4 and 5 of the present invention and the conventional CPP film for electronic screen savers (Comparative Example 1) were subjected to tensile tests and heat resistance tests, respectively, and the experimental values ​​were statistically analyzed. The results are shown in Table 1.

[0030] From the data in Table 1, it can be seen that the tensile test data of the CPP film for electronic screen saver using Examples 1, 2, 3, 4 and 5 of the present invention are 35, 32, 34, 33 and 34 respectively, which are significantly higher than the tensile test data of the CPP film for electronic screen saver in Comparative Example 1. This indicates that the tensile strength of the CPP film for electronic screen saver of the present invention is greatly improved, which improves the product quality.

[0031] From the data in Table 1, it can be seen that the heat resistance data of the CPP film for electronic screen saver using Examples 1, 2, 3, 4 and 5 of the present invention are 35, 32, 34, 33 and 34 respectively, which are significantly higher than the heat resistance data of the CPP film for electronic screen saver in Comparative Example 1. This indicates that the heat resistance of the CPP film for electronic screen saver of the present invention is greatly improved, thereby enhancing the heat resistance function of the product.

[0032] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A method for preparing a tear-resistant and heat-resistant CPP film for electronic screen saver, characterized in that: The method comprises the following steps: Step 1, preparing raw materials; Step 2, melt extrusion; Step 3: stretching and shaping; Step 4, surface coating; Step 5, cooling and coiling; The preparation raw materials include the following parts by weight: 50-60 parts of polypropylene copolymer, 15-30 parts of homopolymer, 18-28 parts of antioxidant, 3-14 parts of anti-ultraviolet agent, 3-7 parts of heat-resistant agent, 10-18 parts of static agent, 2-8 parts of anti-fogging agent, 6-12 parts of anti-blocking agent, and 4-9 parts of lubricant. The preparation materials are put into a melting machine, heated to 300-600° C. to melt them, and the melted preparation materials are extruded through an extruder to form a film with a width of 20-80 cm and a thickness of 0.2-0.9 mm, and the outer wall of the film is coated with a surface coating.

2. The method for producing a tear-resistant and heat-resistant CPP film for electronic screen saver according to claim 1, characterized in that: The surface coating is polyurethane or polyvinyl chloride, and the surface coating improves the tear resistance and temperature resistance of the film.

3. The method for producing a tear-resistant and heat-resistant CPP film for electronic screen saver according to claim 1, characterized in that: The film is stretched by a stretching device to change its physical properties, improve tensile strength, transparency and flatness, the degree and speed of stretching are adjusted according to the required film properties, and the stretched film is subjected to a shaping treatment to ensure its dimensional stability and performance consistency.

4. The method for producing a tear-resistant and heat-resistant CPP film for electronic screen saver according to claim 1, characterized in that: The film is rapidly cooled by a cooling device at a temperature of 10-20° C. to solidify its structure and maintain stability. The cooled film is cut into a suitable size by a cutting device and then wound into a roll by a winder.

5. The method for producing a tear-resistant and heat-resistant CPP film for electronic screen saver according to claim 4, characterized in that: The cooling device is a combination of air cooling and water cooling.

6. The method for producing a tear-resistant and heat-resistant CPP film for electronic screen saver according to claim 1, characterized in that: The heat resistant agent is one of nano-alumina, graphene, ammonium polyphosphate, triphenylphosphoric acid, manganese hydroxybenzoate, silica gel heat resistant agent, and plastic high temperature resistant agent.

7. The method for producing a tear-resistant and heat-resistant CPP film for electronic screen saver according to claim 1, characterized in that: The film surface is subjected to corona treatment to improve the adhesion of the surface coating.

8. The method for producing a tear-resistant and heat-resistant CPP film for electronic screen saver according to claim 1, characterized in that: The film is prepared by composite extrusion of raw materials with different formulas through multi-layer co-extrusion technology to form a CPP film with a multi-layer structure.

9. The method for producing a tear-resistant and heat-resistant CPP film for electronic screen saver according to claim 8, characterized in that: During the composite extrusion process, the cooling speed is controlled within 10 to 20 minutes to avoid stress inside the film.

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