A corona-free release film and preparation method thereof

Abstract

The present invention provides a corona-free release film and a preparation method thereof, and relates to the technical field of release film preparation. The preparation method of the corona-free release film comprises the following steps: S1, preparing a substrate film: preparing an upper surface layer premix, a core layer premix, and a lower surface layer premix respectively; extruding the upper surface layer premix, the core layer premix, and the lower surface layer premix simultaneously in three flow channels to form a thick sheet; sequentially subjecting the thick sheet to longitudinal and transverse stretching treatments, and cooling at a temperature of 30-35°C to form a substrate film; S2, performing a release treatment on the substrate film to obtain a corona-free release film. The release film does not need to undergo corona treatment to obtain a release force, thus avoiding the defect that the corona film must be left to stand for 24 hours before entering the subsequent use process, thereby improving the use of the release film and the subsequent production efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of release film preparation, and in particular to a corona-free release film and a preparation method thereof. Background Art

[0002] Release films are films with a distinct surface energy. Under limited conditions, they exhibit a slight tackiness when in contact with certain materials. This slight tackiness is often referred to in the industry as the release force of the release film. However, most films are non-polar polymers with low surface tension. Therefore, certain materials cannot adhere firmly to the film under limited conditions, meaning that a stable release force cannot be achieved.

[0003] In order to make the film have a stable release force, the existing technology will perform corona treatment on the film to make it show a stable release force for various organic pressure-sensitive adhesives. However, due to the adsorption effect of ionization, the film needs to be left to stand for at least 24 hours after corona treatment before entering the subsequent use process, which affects production efficiency. Therefore, providing a release film that can obtain release force without corona treatment has become a technical problem that needs to be solved urgently. Summary of the Invention

[0004] (1) Technical problems solved

[0005] In response to the shortcomings of the existing technology, the present invention provides a corona-free release film and a preparation method thereof, which solves the technical problem that after the existing release film is corona-treated, the film needs to be left to stand for at least 24 hours before entering the subsequent use process, which affects production efficiency.

[0006] (2) Technical solution

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

[0008] A method for preparing a corona-free release film comprises the following steps:

[0009] S1. Preparation of substrate film:

[0010] S11, preparing the upper surface premix;

[0011] S12, preparing a core layer premix;

[0012] S13, preparing the lower surface premix;

[0013] S14, extruding the upper surface layer premix, the core layer premix, and the lower surface layer premix simultaneously through three channels to form a thick sheet; sequentially stretching the thick sheet longitudinally and transversely, and cooling the sheet at a temperature of 30-35° C. to form a substrate film;

[0014] S2. performing release treatment on the substrate film:

[0015] S21, preparing a release agent;

[0016] S22, performing a release treatment on the substrate film using the release agent to obtain a corona-free release film.

[0017] Preferably, the upper surface layer premix components include: 49-51 parts of polypropylene, 40-48 parts of polyethylene, 1.1-6.3 parts of antistatic agent, and 0.2-0.5 parts of slip agent.

[0018] Preferably, the core layer premix components include: 40-70 parts of high-density polyethylene, 2-15 parts of inorganic matting powder, 2-10 parts of polypropylene, 1-3 parts of dispersant, 0.1-1.0 parts of antioxidant, and 1.1-6.3 parts of antistatic agent.

[0019] Preferably, the lower surface layer premix components include 48-65 parts of polypropylene and 1.0-3.0 parts of silicon dioxide.

[0020] Preferably, the release agent components include: 1-5 parts of maleic anhydride, 0.1-1.0 parts of long-chain silane coupling agent, 75-80 parts of DMF, and 2-10 parts of polyamide-imide.

[0021] Preferably, the long-chain silane coupling agent includes at least one of hexadecyltrimethoxysilane and octadecyltrimethoxysilane.

[0022] Preferably, the long-chain silane coupling agent includes hexadecyltrimethoxysilane and octadecyltrimethoxysilane, and the mass ratio of the hexadecyltrimethoxysilane to the octadecyltrimethoxysilane is (1-2):(2-3).

[0023] Preferably, performing release treatment on the substrate film comprises: soaking the substrate film in the release agent solution, and placing the soaked substrate film in a high-temperature oven at 90-100° C. for 0.5-1 hour, thereby completing the release treatment.

[0024] On the other hand, a corona-free release film prepared by the preparation method has a release force of 0.4-0.6N / 25MM.

[0025] (3) Beneficial effects

[0026] The present invention provides a corona-free release film and a preparation method thereof. Compared with the prior art, the present invention has the following beneficial effects:

[0027] The preparation method of the corona-free release film applied in the present invention obtains the release force by performing a release treatment on the substrate film without the need for corona treatment, thereby avoiding the defect that the corona-treated film needs to be left to stand for 24 hours before entering the subsequent use process, thereby improving the use of the release film and the subsequent production efficiency. DETAILED DESCRIPTION

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0029] The embodiments of the present application provide a corona-free release film and a preparation method thereof, thereby solving the problem that after corona treatment, the film needs to be left to stand for at least 24 hours before entering the subsequent use process, which affects production efficiency.

[0030] The technical solution in the embodiments of the present application is to solve the above technical problems, and the overall idea is as follows:

[0031] The present invention prepares a release film by subjecting a substrate film to a release treatment using a release agent. The release agent comprises maleic anhydride, a long-chain silane coupling agent, and polyamide-imide. Both polyamide-imide and maleic anhydride contain carbonyl groups. Therefore, after the release agent containing polyamide-imide and maleic anhydride impregnates the substrate film and is dried under certain temperature conditions, the surface energy of the substrate film is increased, thereby generating a release force for the substrate film. The long-chain silane coupling agent forms covalent bonds with the polyamide-imide and the substrate film surface during the impregnation process, promoting the bonding of the release agent and the substrate film.

[0032] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with specific implementation methods.

[0033] Example 1

[0034] This embodiment provides a method for preparing a corona-free release film, comprising the following steps:

[0035] S1, preparing a substrate film, comprising the following steps:

[0036] S11. Prepare the upper surface layer premix: The upper surface layer premix comprises: 49 parts of polypropylene, 40 parts of polyethylene, 1.1 parts of antistatic agent, and 0.2 parts of lubricant.

[0037] S12. Prepare core layer premix: The components of the core layer premix include: 40 parts of high-density polyethylene, 2 parts of inorganic matting powder, 2 parts of polypropylene, 1 part of dispersant, 0.1 part of antioxidant, and 1.1 parts of antistatic agent.

[0038] S13. Prepare a lower surface layer premix: The lower surface layer premix comprises 48 parts of polypropylene and 1.0 part of silicon dioxide.

[0039] S14, extruding the upper surface layer premix, the core layer premix, and the lower surface layer premix simultaneously through a die opening in three flow channels to form a thick sheet; sequentially stretching the thick sheet longitudinally and transversely, and cooling the sheet at a temperature of 30° C. to form a substrate film;

[0040] S2. Release treatment of substrate film

[0041] S21. Prepare a release agent: disperse 1 part of maleic anhydride and 0.1 part of octadecyltrimethoxysilane in 75 parts of DMF in sequence under stirring, then add 2 parts of polyamideimide and stir for 30 minutes to obtain a release agent solution.

[0042] S22. Perform release treatment on the substrate film: soak the substrate film in a release agent solution, and place the soaked substrate film in a high-temperature oven at 90° C. for 0.5 h to obtain a corona-free release film.

[0043] Example 2

[0044] This embodiment provides a method for preparing a corona-free release film, comprising the following steps:

[0045] S1, preparing a substrate film, comprising the following steps:

[0046] S11. Prepare the upper surface layer premix: The upper surface layer premix comprises: 50 parts of polypropylene, 45 parts of polyethylene, 3 parts of antistatic agent, and 0.3 parts of lubricant.

[0047] S12. Prepare core layer premix: The components of the core layer premix include: 50 parts of high-density polyethylene, 10 parts of inorganic matting powder, 8 parts of polypropylene, 2 parts of dispersant, 0.8 parts of antioxidant, and 5 parts of antistatic agent.

[0048] S13. Prepare the lower surface layer premix: the lower surface layer premix comprises 60 parts of polypropylene and 2 parts of silicon dioxide.

[0049] S14, extruding the upper surface layer premix, the core layer premix, and the lower surface layer premix simultaneously through a die opening in three flow channels to form a thick sheet; sequentially stretching the thick sheet longitudinally and transversely, and cooling the sheet at a temperature of 33° C. to form a substrate film;

[0050] S2. Release treatment of substrate film

[0051] S21. Prepare a release agent: disperse 3 parts of maleic anhydride and 0.5 parts of hexadecyltrimethoxysilane in 78 parts of DMF in sequence under stirring, then add 8 parts of polyamideimide and stir for 50 minutes to obtain a release agent solution.

[0052] S22. Perform release treatment on the substrate film: soak the substrate film in a release agent solution, and place the soaked substrate film in a high-temperature oven at 95° C. for 0.8 h to obtain a corona-free release film.

[0053] Example 3

[0054] This embodiment provides a method for preparing a corona-free release film, comprising the following steps:

[0055] S1, preparing a substrate film, comprising the following steps:

[0056] S11. Prepare the upper surface layer premix: The upper surface layer premix comprises: 51 parts of polypropylene, 48 parts of polyethylene, 6.3 parts of antistatic agent, and 0.5 parts of lubricant.

[0057] S12. Prepare core layer premix: The components of the core layer premix include: 70 parts of high-density polyethylene, 15 parts of inorganic matting powder, 10 parts of polypropylene, 3 parts of dispersant, 1.0 part of antioxidant, and 6.3 parts of antistatic agent.

[0058] S13. Prepare a lower surface layer premix: The lower surface layer premix comprises 65 parts of polypropylene and 3.0 parts of silicon dioxide.

[0059] S14, extruding the upper surface layer premix, the core layer premix, and the lower surface layer premix simultaneously through a die opening in three flow channels to form a thick sheet; sequentially stretching the thick sheet longitudinally and transversely, and cooling the sheet at a temperature of 35° C. to form a substrate film;

[0060] S2. Release treatment of substrate film

[0061] S21. Prepare a release agent: disperse 5 parts of maleic anhydride, 1.0 part of hexadecyltrimethoxysilane and 18decyltrimethoxysilane in 80 parts of DMF in sequence under stirring, with the mass ratio of hexadecyltrimethoxysilane to 18decyltrimethoxysilane being 1:2, and then add 10 parts of polyamideimide and stir for 60 minutes to obtain a release agent solution.

[0062] S22. Performing release treatment on the substrate film: soaking the substrate film in a release agent solution, and placing the soaked substrate film in a high-temperature oven at 100° C. for 1 hour to obtain a corona-free release film.

[0063] The release forces of the corona-free release films prepared in Examples 1-3 were tested, and the results are shown in Table 1.

[0064] Release force test method: Use an electronic peel tester to test the release force of the prepared corona-free release film in accordance with GB / T 4850.

[0065] Table 1 Release force test results of the prepared corona-free release film

[0066]

[0067] As shown in Table 1, the release force of the corona-free release film prepared by the present invention is 0.4-0.6N / 25MM, which meets the use requirements.

[0068] It should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0069] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0070] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0071] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for preparing a corona-free release film, characterized in that: The steps include: S1. Preparation of substrate film: S11, preparing the upper surface premix; S12, preparing a core layer premix; S13, preparing the lower surface premix; S14, extruding the upper surface layer premix, the core layer premix, and the lower surface layer premix simultaneously through three channels to form a thick sheet; sequentially stretching the thick sheet longitudinally and transversely, and cooling the sheet at a temperature of 30-35° C. to form a substrate film; S2. performing release treatment on the substrate film: S21, preparing a release agent; The release agent components include: 1-5 parts of maleic anhydride, 0.1-1.0 parts of long-chain silane coupling agent, 75-80 parts of DMF, and 2-10 parts of polyamide-imide; S22, performing a release treatment on the substrate film using the release agent to obtain a corona-free release film; The upper surface layer premix components include: 49-51 parts of polypropylene, 40-48 parts of polyethylene, 1.1-6.3 parts of antistatic agent, and 0.2-0.5 parts of lubricant; the core layer premix components include: 40-70 parts of high-density polyethylene, 2-15 parts of inorganic matting powder, 2-10 parts of polypropylene, 1-3 parts of dispersant, 0.1-1.0 parts of antioxidant, and 1.1-6.3 parts of antistatic agent; the lower surface layer premix components include: 48-65 parts of polypropylene and 1.0-3.0 parts of silicon dioxide.

2. The preparation method according to claim 1, wherein The long-chain silane coupling agent includes at least one of hexadecyltrimethoxysilane and octadecyltrimethoxysilane.

3. The preparation method according to claim 1, wherein The long-chain silane coupling agent includes hexadecyltrimethoxysilane and octadecyltrimethoxysilane, and the mass ratio of the hexadecyltrimethoxysilane to the octadecyltrimethoxysilane is (1-2):(2-3).

4. The preparation method according to claim 1, wherein The release treatment of the substrate film includes: soaking the substrate film in the release agent solution, placing the soaked substrate film in a high-temperature oven at 90-100° C. for 0.5-1 hour, thereby completing the release treatment.

5. A corona-free release film prepared by the preparation method according to any one of claims 1 to 4, characterized in that: The release force of the release film is 0.4-0.6N / 25MM.

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