Matt film and production method thereof

Abstract

The invention discloses a matt film and a production method thereof, and relates to the field of films, the matt film comprises a film adhesive layer, matt diamond patterns are integrally formed on the surface of the film adhesive layer, and film surface layers are bonded on the upper end face and the lower end face of the film adhesive layer. The method specifically comprises the following steps: preparing a base film material, forming a base film, embossing textures, coating a matte coating, longitudinally stretching, carrying out electron beam irradiation treatment, carrying out corona treatment and rolling. According to the matt film and the production method thereof, high haze is achieved through the matt diamond patterns integrally formed on the surface of the film adhesive layer and a composite structure of the upper film surface layer and the lower film surface layer, biodegradable polyester is adopted as a base material, the film can be naturally degraded after being discarded, the tensile strength and wear resistance of the film are remarkably improved due to addition of nano silicon dioxide, and the matt film is suitable for large-scale production. Molecular crosslinking is promoted through the electron beam irradiation and ultraviolet curing steps, the hardness of the coating is improved by 15%, the coating thickness is monitored in real time through an intelligent control system, and it is guaranteed that a film body is flat and free of defects.

Description

Technical Field

[0001] This invention relates to the field of thin films, and in particular to a matte thin film and its production method. Background Technology

[0002] Matte film is a functional material with low gloss and high haze characteristics. It is widely used in packaging, electronic screen protection, home decoration and other fields. Its core value lies in providing visual comfort, anti-glare effect and beautiful surface.

[0003] However, when using matte films, traditional matte films rely heavily on adding inorganic matting agents or surface coating processes to achieve a matte finish. This is achieved by mixing a high proportion of matting masterbatch into high-density polyethylene or polyester substrates. However, this method generally results in film haze below 50%, gloss at a 60° angle often exceeding 15 GU, and is prone to defects such as uneven gloss, fisheyes, or pinholes. While adding matting agents can improve surface roughness, excessive use can damage the film's mechanical integrity, causing tensile strength to drop below 25 MPa and elongation at break to be less than 100%. Furthermore, existing films have a simple surface structure, lacking fine texture design, resulting in poor light scattering and glare, negatively impacting the visual experience. Additionally, mainstream matte films are based on petroleum-based polymers, which... The materials are non-degradable and easily cause white pollution after disposal. Although some studies have attempted to use bio-based materials, this often comes at the cost of performance. Furthermore, traditional film reinforcement methods are limited to adding fillers or simple cross-linking, primarily using electron beam irradiation to improve temperature resistance, but without combining with nanomaterials for synergistic reinforcement. This results in limited improvement in coating hardness, typically less than 10%, and insufficient wear resistance. During the stretching process, due to the lack of precise control methods such as negative pressure adsorption, the film is prone to lateral shrinkage and edge accumulation during longitudinal stretching, leading to poor flatness and a lateral shrinkage rate exceeding 10%, affecting the yield of subsequent processing. Existing production methods mostly employ offline coating or complex multi-layer co-extrusion processes, which are lengthy, have low precision in coating thickness control (error exceeding ±0.5μm), and typically have production speeds below 5m / min. The water-based coating solution lacks sufficient leveling and antistatic properties, easily leading to coating defects and requiring repeated parameter adjustments, increasing energy consumption and time costs. Summary of the Invention

[0004] The main objective of this invention is to provide a matte film and its production method, which can effectively solve the technical problems raised in the background art.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A matte film includes a film adhesive layer, the surface of which is integrally formed with a matte diamond pattern, and a film surface layer is bonded to both the upper and lower surfaces of the film adhesive layer.

[0007] Preferably, the thickness of the film adhesive layer is greater than the thickness of the film surface layer.

[0008] Preferably, the film surface layer covers the outside of the matte diamond pattern, and the upper and lower film surface layers are of the same size.

[0009] A method for producing a matte film, the method specifically includes the following steps:

[0010] Step 1: Prepare the base film material by mixing biodegradable polyester chips with nano-silica at a mass ratio of 95-100:1-5, drying and pre-crystallizing the mixture for later use. The drying temperature is 120-150℃ and the pre-crystallization time is 2-4 hours.

[0011] Step 2: Base film forming and texture imprinting. The material obtained in Step 1 is melted and extruded onto the casting roller. The extrusion temperature is controlled at 200-250℃ and the casting roller temperature is 15-40℃ to form a thin film adhesive layer. At the same time, a matte diamond pattern is imprinted on the surface of the thin film adhesive layer by an embossing roller. The embossing pressure is 5-15MPa and the temperature is 60-100℃.

[0012] Step 3: Apply a matte coating. Apply an aqueous matte coating liquid online to the upper and lower surfaces of the film adhesive layer. The coating thickness is 0.5-2μm. The aqueous matte coating liquid contains aqueous polyurethane resin, matting agent and antistatic agent, with a mass ratio of 100:10-20:5-10.

[0013] Step 4: Longitudinal stretching. The coated film is longitudinally stretched at 70-90℃, with a stretching ratio of 2.5-3.5:1 and a stretching speed of 5-15m / min.

[0014] Step 5: Electron beam irradiation treatment. The stretched film is irradiated with an electron beam at a dose of 10-15 mrad / m² to enhance crosslinking and temperature resistance.

[0015] Step Six: Corona Treatment and Rewinding. The film surface is treated in a corona treatment device with a corona power of 500-1000W. After treatment, the film is rewound and slit to obtain the matte film product.

[0016] Preferably, the biodegradable polyester chips in step one are polylactic acid (PLA) and polyhydroxyalkanoate (PHA), with a melt index of 2-10 g / 10 min, under the following conditions: 190 °C, 2.16 kg.

[0017] Preferably, the aqueous matte coating liquid in step three further includes an abrasion resistant agent and a leveling agent. The abrasion resistant agent is a carbon nanotube dispersion, and the leveling agent is an acrylic compound. The addition amounts are 2-5% and 1-3% of the mass of the aqueous polyurethane resin, respectively.

[0018] Preferably, the longitudinal stretching in step four is performed on a stretching roller with negative pressure adsorption, with a negative pressure value of 100-150 mbar, to ensure the flatness of the film and reduce lateral shrinkage.

[0019] Preferably, step five is followed by an ultraviolet curing step, in which the film is irradiated with ultraviolet light at a wavelength of 200-400 nm for 10-30 seconds to further improve the hardness of the coating.

[0020] Preferably, the production method further includes step seven: recycling scrap materials, crushing the chopped scrap materials and remixing them into the material from step one, with the recycling ratio not exceeding 10% of the total mass.

[0021] Preferably, the coating process in step three employs an intelligent control system, which uses sensors to monitor the coating thickness and uniformity in real time and provides feedback to adjust the coating speed, with a control accuracy of ±0.1μm.

[0022] The beneficial effects achievable by the above embodiments of the present invention include: through the composite structure of the matte diamond pattern integrally formed on the surface of the thin film adhesive layer and the upper and lower thin film surfaces, high haze (up to 50-90%) and low gloss (gloss at a 60° angle is less than 10 GU) are achieved. The matte diamond pattern forms a finely textured surface that effectively scatters light, produces a uniform frosted effect, avoids glare, and improves visual comfort. At the same time, the thin film surface covers the outside of the diamond pattern, ensuring a smooth surface and balancing aesthetics and tactile feel.

[0023] Using biodegradable polyester as the substrate and reinforced with nano-silica, the film can be naturally degraded after disposal, reducing white pollution. The scrap recycling process further reduces resource waste, which is in line with the concept of circular economy. Compared with traditional petroleum-based films, the carbon footprint is reduced by more than 20%.

[0024] The addition of nano-silica significantly improves the tensile strength and abrasion resistance of the film, reaching 30-40 MPa. Electron beam irradiation and ultraviolet curing promote molecular cross-linking, increasing the coating hardness by 15%, resulting in excellent scratch resistance and extended service life. At the same time, the matte diamond-patterned structure enhances the toughness of the film, increasing the elongation at break to 120-150%.

[0025] The production speed reaches 5-15m / min, which is 20% more efficient than the traditional method. The carbon nanotube dispersion and acrylic leveling agent in the coating liquid further improve the coating uniformity and avoid fish eyes or pinholes. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of a matte film according to the present invention;

[0027] Figure 2This is a flowchart of a method for producing a matte film according to the present invention.

[0028] In the diagram: 1. Main body of curbstone; 2. Extension reinforcing block; 3. Supporting and reinforcing rod; 4. Drainage channel; 5. Main body docking groove; 6. Curbstone protrusion; 7. Protrusion docking groove; 8. Docking block; 9. Main body water collection base; 10. Protrusion water collection base. Detailed Implementation

[0029] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0030] like Figure 1 As shown, a matte film includes a film adhesive layer 1, the surface of which is integrally formed with a matte diamond pattern 2, and a film surface layer 3 is bonded to both the upper and lower ends of the film adhesive layer 1.

[0031] In this embodiment, the thickness of the thin film adhesive layer 1 is greater than the thickness of the thin film surface layer 3.

[0032] In this embodiment, the thin film surface layer 3 covers the outside of the matte diamond pattern 2, and the upper and lower thin film adhesive layers 3 are the same size.

[0033] Specifically, film adhesive layer 1 is the central base layer of the film, film adhesive layer 3 is the outer exposed surface layer of the film, matte diamond texture 2 is a slightly uneven tactile feel, and a matte structure is achieved under film adhesive layer 3. The surface of film adhesive layer 3 can be a smooth surface, thus achieving a matte and smooth surface structure of the film.

[0034] like Figure 2 As shown, a method for producing a matte film includes the following steps:

[0035] Step 1: Prepare the base film material by mixing biodegradable polyester chips with nano-silica at a mass ratio of 95-100:1-5, drying and pre-crystallizing the mixture for later use. The drying temperature is 120-150℃ and the pre-crystallization time is 2-4 hours.

[0036] Step 2: Base film forming and texture imprinting. The material obtained in Step 1 is melted and extruded onto a casting roller. The extrusion temperature is controlled at 200-250℃ and the casting roller temperature is 15-40℃ to form a thin film adhesive layer 1. At the same time, a matte diamond pattern 2 is imprinted on the surface of the thin film adhesive layer 1 using an embossing roller. The embossing pressure is 5-15MPa and the temperature is 60-100℃.

[0037] Step 3: Apply matte coating. Apply water-based matte coating liquid online to the upper and lower surfaces of the thin film adhesive layer 1. The coating thickness is 0.5-2μm. The water-based matte coating liquid contains water-based polyurethane resin, matting agent and antistatic agent, with a mass ratio of 100:10-20:5-10.

[0038] Step 4: Longitudinal stretching. The coated film is longitudinally stretched at 70-90℃, with a stretching ratio of 2.5-3.5:1 and a stretching speed of 5-15m / min.

[0039] Step 5: Electron beam irradiation treatment. The stretched film is irradiated with an electron beam at a dose of 10-15 mrad / m² to enhance crosslinking and temperature resistance.

[0040] Step Six: Corona Treatment and Rewinding. The film surface is treated in a corona treatment device with a corona power of 500-1000W. After treatment, the film is rewound and slit to obtain the matte film product.

[0041] In this embodiment, the biodegradable polyester chips in step one are polylactic acid (PLA) and polyhydroxyalkanoate (PHA), with a melt index of 2-10 g / 10 min and conditions of 190°C and 2.16 kg.

[0042] In this embodiment, the aqueous matte coating liquid in step three also includes an abrasion resistant agent and a leveling agent. The abrasion resistant agent is a carbon nanotube dispersion, and the leveling agent is an acrylic compound. The addition amounts are 2-5% and 1-3% of the mass of the aqueous polyurethane resin, respectively.

[0043] In this embodiment, the longitudinal stretching in step four is performed on a stretching roller with negative pressure adsorption, with a negative pressure value of 100-150 mbar, to ensure the flatness of the film and reduce lateral shrinkage.

[0044] In this embodiment, step five is followed by an ultraviolet curing step, in which the film is irradiated with ultraviolet light at a wavelength of 200-400nm for 10-30 seconds to further improve the hardness of the coating.

[0045] In this embodiment, the production method further includes step seven: recycling scrap materials, crushing the chopped scrap materials and remixing them into the material from step one, with the recycling ratio not exceeding 10% of the total mass.

[0046] In this embodiment, the coating process in step three adopts an intelligent control system, which monitors the coating thickness and uniformity in real time through sensors and adjusts the coating speed accordingly, with a control accuracy of ±0.1μm.

[0047] In the embodiments provided by this invention, it should be understood that the disclosed devices, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and other division methods may exist in actual implementation. Modules described as separate components may or may not be physically separated, and components shown as modules may or may not be physical units, i.e., they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of the method in this embodiment according to actual needs.

[0048] The above embodiments are only used to illustrate the technical methods of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical methods of the present invention without departing from the spirit and scope of the technical methods of the present invention.

Claims

1. A matte film, comprising a film adhesive layer (1), characterized in that: The surface of the film adhesive layer (1) is integrally formed with a matte diamond pattern (2), and the upper and lower surfaces of the film adhesive layer (1) are both bonded with a film surface layer (3).

2. The matte film according to claim 1, characterized in that: The thickness of the film adhesive layer (1) is greater than the thickness of the film surface layer (3).

3. The matte film according to claim 1, characterized in that: The thin film surface layer (3) covers the outside of the matte diamond pattern (2), and the upper and lower thin film surface layers (3) are the same size.

4. A method for producing a matte film according to any one of claims 1-3, characterized in that, The method specifically includes the following steps: Step 1: Prepare the base film material by mixing biodegradable polyester chips with nano-silica at a mass ratio of 95-100:1-5, drying and pre-crystallizing the mixture for later use. The drying temperature is 120-150℃ and the pre-crystallization time is 2-4 hours. Step 2: Base film forming and texture imprinting. The material obtained in Step 1 is melted and extruded onto the casting roller. The extrusion temperature is controlled at 200-250℃ and the casting roller temperature is 15-40℃ to form a thin film adhesive layer (1). At the same time, a matte diamond pattern (2) is imprinted on the surface of the thin film adhesive layer (1) by an embossing roller. The embossing pressure is 5-15MPa and the temperature is 60-100℃. Step 3: Apply a matte coating. Apply an aqueous matte coating liquid online to the upper and lower surfaces of the thin film adhesive layer (1). The coating thickness is 0.5-2μm. The aqueous matte coating liquid contains aqueous polyurethane resin, matting agent and antistatic agent, with a mass ratio of 100:10-20:5-10. Step 4: Longitudinal stretching. The coated film is longitudinally stretched at 70-90℃, with a stretching ratio of 2.5-3.5:1 and a stretching speed of 5-15m / min. Step 5: Electron beam irradiation treatment. The stretched film is irradiated with an electron beam at a dose of 10-15 mrad / m² to enhance crosslinking and temperature resistance. Step Six: Corona Treatment and Rewinding. The film surface is treated in a corona treatment device with a corona power of 500-1000W. After treatment, the film is rewound and slit to obtain the matte film product.

5. The method for producing a matte film according to claim 4, characterized in that: In step one, the biodegradable polyester chips are polylactic acid (PLA) and polyhydroxyalkanoate (PHA), with a melt index of 2-10 g / 10 min, under the following conditions: 190 °C, 2.16 kg.

6. The method for producing a matte film according to claim 4, characterized in that: The water-based matte coating liquid in step three also contains abrasion resistant agent and leveling agent. The abrasion resistant agent is a carbon nanotube dispersion, and the leveling agent is an acrylic compound. The addition amounts are 2-5% and 1-3% of the mass of the water-based polyurethane resin, respectively.

7. The method for producing a matte film according to claim 4, characterized in that: The longitudinal stretching in step four is performed on a stretching roller with negative pressure adsorption, with a negative pressure value of 100-150 mbar, to ensure the flatness of the film and reduce lateral shrinkage.

8. The method for producing a matte film according to claim 4, characterized in that: Step five is followed by an ultraviolet curing step, in which the film is irradiated with ultraviolet light at a wavelength of 200-400nm for 10-30 seconds to further improve the hardness of the coating.

9. A method for producing a matte film according to claim 4, characterized in that: The production method further includes step seven: recycling scrap materials, crushing the chopped scrap materials and mixing them back into the material from step one, with the recycling ratio not exceeding 10% of the total mass.

10. A method for producing a matte film according to claim 4, characterized in that: The coating process in step three employs an intelligent control system, which uses sensors to monitor the coating thickness and uniformity in real time and adjusts the coating speed accordingly, with a control accuracy of ±0.1μm.

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