A wear-resistant polyimide film and a method for manufacturing the same

Abstract

The present invention relates to a wear-resistant polyimide film and a manufacturing method thereof, wherein the wear-resistant polyimide film comprises a main film body, an anti-wear layer and a reinforcement layer; the main film body is a polyimide film; the anti-wear layer is composed of a plurality of first anti-wear particles laid on the film surface of the main film body, and each particle body of the first anti-wear particles is partially embedded in the film surface of the main film body; the reinforcement layer is coated on the anti-wear layer and the main film body, and the reinforcement layer at least fills the gaps between each of the first anti-wear particles. The wear-resistant polyimide film manufactured by the present invention is not only structurally stable and not easy to fall off, but also can protect the surface of the screen from being scratched when used as a protective film layer of a flexible display screen, and the anti-wear layer can also play the role of optical scattering, so that when the polyimide film is used as a protective layer of a flexible display screen, the screen body is not easy to reflect light, which is conducive to the observation of the flexible display screen and has a certain anti-glare effect.

Description

Technical Field

[0001] The invention relates to the field of polyimide films, and in particular to a wear-resistant polyimide film and a manufacturing method thereof. Background Art

[0002] Polyimide film has extremely good heat resistance (400°C) and weather resistance, and can be used as a substrate and protective film layer in curved or flexible displays. However, when polyimide film is used as a protective film layer for flexible displays, the surface of the flexible display is very easy to scratch due to the insufficient hardness of the polyimide film (especially colorless polyimide film). In addition, when polyimide film is used as a screen, its surface is generally smooth and easily reflects light, which affects the viewing experience of the flexible display.

[0003] In addition, although there is also a method of coating a hardened film on the surface of a polyimide film in the prior art to increase its surface hardness, since the hardness of the hardened film is significantly different from that of the polyimide film, the bonding strength between the hardened film and the polyimide film is relatively poor, and the hardened film is prone to fall off during use. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a wear-resistant polyimide film and a method for manufacturing the same. The wear-resistant polyimide film is not only structurally stable and not prone to falling off, but also can protect the surface of the screen from scratches when used as a protective film layer of a flexible display screen, and has a certain anti-glare effect. The technical solution adopted is as follows:

[0005] A wear-resistant polyimide film comprises a main film body, which is a polyimide film; the characteristic is that: the wear-resistant polyimide film also comprises an anti-wear layer and a reinforcement layer; the anti-wear layer is composed of a plurality of first anti-wear particles laid on the film surface of the main film body, and the particle body of each first anti-wear particle is partially embedded in the film surface of the main film body; the reinforcement layer is coated on the anti-wear layer and the main film body, and the reinforcement layer at least fills the gaps between each of the first anti-wear particles.

[0006] In the structure of this wear-resistant polyimide film, the anti-wear layer is formed by laying a plurality of first anti-wear particles on the film surface of the main film body. The particle bodies of each first anti-wear particle are partially embedded in the film surface of the main film body, so that the combination between the anti-wear layer and the main film body is relatively stable, and thus the first wear-resistant particles are not easily detached. Moreover, the reinforcement layer is coated on the anti-wear layer and the main film body. In particular, the gaps between the first wear-resistant particles are filled, which can further reinforce the combination between the anti-wear layer and the main film body. When the surface of the polyimide film is subjected to friction and torque is formed on the first wear-resistant particles, the reinforcement layer filled between the first wear-resistant particles can further resist the torque received by the first wear-resistant particles and prevent them from falling off. In addition, the anti-wear layer can also function as an optical scatterer, making the screen of the polyimide film not easily reflect light and having a certain anti-glare effect when the polyimide film is used as a protective layer for a flexible display screen, which can improve the viewing experience of users for the flexible display screen.

[0007] As a preferred embodiment of the present invention, the main film body is a colorless polyimide film, and the thickness of the main film body is 10 μm to 200 μm.

[0008] As a specific embodiment of the present invention, a plurality of the first anti-wear particles cover the film surface of the main film body.

[0009] As a preferred embodiment of the present invention, the first anti-wear particles are silicon oxide powder particles.

[0010] As a further preferred embodiment of the present invention, the first anti-wear particles are spherical particles, and the particle size of the first anti-wear particles is between 500 nm and 50 μm.

[0011] As a preferred embodiment of the present invention, the reinforcement layer is a photosensitive resin coating.

[0012] As a further preferred embodiment of the present invention, the refractive index of the reinforcement layer differs from the refractive index of the first anti-wear particles by no more than 0.15.

[0013] As a preferred embodiment of the present invention, the reinforcement layer contains a plurality of second anti-wear particles, and the particle size of the second anti-wear particles is less than 50% of the first anti-wear particles. By adding the second anti-wear particles to the reinforcement layer, not only can the overall structure of the wear-resistant polyimide film be made more stable, but also the reinforcement layer can have the function of optical scattering.

[0014] As a further preferred embodiment of the present invention, both the second anti-wear particles and the first anti-wear particles are silicon oxide powder particles.

[0015] As a further preferred embodiment of the present invention, the second wear-resistant particles are indium tin oxide powder. By adding indium tin oxide powder as the second wear-resistant particles in the reinforcement layer, the indium tin oxide powder is embedded between the first wear-resistant particles, which can eliminate static electricity. Due to the high resistivity of the polyimide film, it is easy to accumulate charges and form static electricity during processing.

[0016] The present invention also provides a method for manufacturing the wear-resistant polyimide film, which is characterized by comprising the following steps:

[0017] (1) coating a polyimide precursor solution on a mother board and drying it at a temperature of 80° C. to 150° C. to obtain an uncured main film;

[0018] (2) spreading the first anti-wear particles on the surface of the main film, and embedding a particle part of each first anti-wear particle into the main film;

[0019] (3) fully curing the main film at a high temperature of more than 200° C. to form an anti-wear layer composed of a plurality of first anti-wear particles on the film surface of the main film;

[0020] (4) coating a photosensitive resin coating on the film surface of the main film body, and after the photosensitive resin coating fully penetrates into the gaps between the first anti-wear particles, irradiating the photosensitive resin coating with ultraviolet light to cure the photosensitive resin coating, thereby forming a reinforcement layer on the anti-wear layer;

[0021] (5) All material layers attached to the motherboard are peeled off from the motherboard to obtain the wear-resistant polyimide film.

[0022] As a preferred solution of the present invention, the motherboard is a glass substrate.

[0023] As a preferred embodiment of the present invention, the precursor solution of the polyimide is a polyamic acid solution.

[0024] As a preferred embodiment of the present invention, in step (2), pressure is applied to partially embed the particle bodies of each first anti-wear particle into the film surface of the main film body. The pressure can be applied by rolling to apply pressure to the particle bodies of the first anti-wear particle so that the particle bodies are partially embedded into the film surface of the main film body.

[0025] As another preferred embodiment of the present invention, in step (2), a powder spraying process is used to spray the airflow with the first anti-wear particles onto the film surface of the main film body, and the first anti-wear particles are partially embedded into the film surface of the main film body under the action of their own momentum. The airflow velocity can be adjusted so that the first anti-wear particles have the momentum to embed into the film surface of the main film body, thereby controlling the depth of the first anti-wear particles embedded into the film surface of the main film body.

[0026] As a preferred embodiment of the present invention, in step (2), an excess amount of first anti-wear particles are spread on the surface of the main film body; after step (2) or step (3), excess particles not embedded in the surface of the main film body are removed by vacuum adsorption or air blowing.

[0027] Compared with the prior art, the present invention has the following advantages:

[0028] The present invention lays a plurality of first anti-wear particles on the surface of the main film body, and partially embeds the particle body of each first anti-wear particle within the surface of the main film body to form an anti-wear layer, and then coats a reinforcement layer on the anti-wear layer and the main film body, especially filling the gaps between the first wear-resistant particles, so that the connection between the anti-wear layer and the main film body can be reinforced, and when the surface of the polyimide film is subjected to friction and torque is formed on the first wear-resistant particles, the reinforcement layer filled between the first wear-resistant particles can further resist the torque exerted on the first wear-resistant particles, which not only makes the overall structure of the wear-resistant polyimide film more stable and less likely to fall off, but also protects the surface of the screen from being scratched when used as a protective film layer of the flexible display screen, and the anti-wear layer can also play the role of optical scattering, so that when the polyimide film is used as a protective layer of the flexible display screen, the screen body is not easy to reflect light, and has a certain anti-glare effect, which can enhance the user's viewing experience of the flexible display screen. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the structure of the wear-resistant polyimide film provided by the preferred embodiment 1 and embodiment 2 of the present invention.

[0030] Figure 2 It is a schematic flow chart of the manufacturing method provided in the first preferred embodiment of the present invention.

[0031] Figure 3 It is a schematic diagram of step (2) in the manufacturing method provided in the second preferred embodiment of the present invention. DETAILED DESCRIPTION

[0032] Embodiment 1

[0033] like Figure 1 , Figure 2 As shown, the wear-resistant polyimide film comprises a main film body 1, an anti-wear layer 2 and a reinforcement layer 3; the main film body 1 is a polyimide film; the anti-wear layer 2 is composed of a plurality of first anti-wear particles 21 laid on the film surface of the main film body 1, and the particle body of each first anti-wear particle 21 is partially embedded in the film surface of the main film body 1; the reinforcement layer 3 is coated on the anti-wear layer 2 and the main film body 1, and the reinforcement layer 3 at least fills the gaps between each of the first anti-wear particles 21.

[0034] In this embodiment, the main film body 1 is a colorless polyimide film, and the thickness of the main film body 1 is 10 μm to 200 μm.

[0035] In this embodiment, a plurality of first anti-wear particles 21 are spread over the entire film surface of the main film body 1 .

[0036] In this embodiment, the first wear-resistant particles 21 are spherical silicon oxide powder particles, and the particle size of the first wear-resistant particles 21 is between 500 nm and 50 μm.

[0037] In this embodiment, the reinforcement layer 3 is a photosensitive resin coating, and the difference between the refractive index of the reinforcement layer 3 and the refractive index of the first anti-wear particles 21 is no more than 0.15.

[0038] In this embodiment, the reinforcement layer 3 contains a plurality of second anti-wear particles 31, which are silicon oxide powder particles, and the particle size of the second anti-wear particles 31 is less than 50% of the first anti-wear particles 21. By adding the second anti-wear particles 31 to the reinforcement layer 3, not only can the overall structure of the wear-resistant polyimide film be more stable, but also the reinforcement layer 3 can have an optical scattering function.

[0039] This embodiment also provides a method for manufacturing the wear-resistant polyimide film, comprising the following steps:

[0040] (1) coating a polyimide precursor solution (such as a polyamic acid solution) on a mother board 10 (such as a glass substrate), and drying the mother board 10 at a temperature of 80° C. to 150° C. to obtain an uncured main film body 1;

[0041] (2) firstly, an excess amount of first anti-wear particles 21 are spread on the surface of the main film body 1, and a pressure roller 20 is used to apply pressure so that each particle of the first anti-wear particles 21 is partially embedded in the main film body 1, and then a first spray device 30 is used to blow air to remove excess particles that are not embedded in the surface of the main film body 1;

[0042] (3) fully curing the main film body 1 at a high temperature above 200° C. to form an anti-wear layer 2 composed of a plurality of first anti-wear particles 21 on the film surface of the main film body 1;

[0043] (4) coating a photosensitive resin coating on the film surface of the main film body 1, and after the photosensitive resin coating fully penetrates into the gaps between the first anti-wear particles 21, irradiating ultraviolet light to cure the photosensitive resin coating, thereby forming a reinforcement layer 3 on the anti-wear layer 2;

[0044] (5) All material layers attached to the motherboard 10 are peeled off from the motherboard 10 to obtain the wear-resistant polyimide film.

[0045] Embodiment 2

[0046] refer to Figure 3, while other parts are the same as those in Example 1, the difference is that: in this embodiment, the second wear-resistant particles 31 are indium tin oxide powder; by adding indium tin oxide powder as the second wear-resistant particles 31 in the reinforcement layer 3, it is embedded between the first wear-resistant particles, which can play a role in eliminating static electricity. Due to the high resistivity of the polyimide film, it is easy to accumulate charges and form static electricity during the processing.

[0047] In the manufacturing method of the wear-resistant polyimide film provided in this embodiment, the powder spraying process is adopted in the step (2), and the airflow (such as compressed air or nitrogen) carrying the first wear-resistant particles 21 is sprayed on the film surface of the main film body 1 by the second spraying device 40, and these first wear-resistant particles 21 are partially embedded into the film surface of the main film body 1 under the action of their own momentum. The first wear-resistant particles 21 can be made to have momentum to embed into the film surface of the main film body 1 by adjusting the airflow speed, so as to control the depth of the first wear-resistant particles 21 embedded into the film surface of the main film body 1.

[0048] In addition, it should be noted that the names of the various parts of the specific embodiments described in this specification may be different, and any equivalent or simple changes made based on the structure, features and principles described in the patent concept of the present invention are included in the protection scope of the patent of the present invention. The technicians in the technical field of the present invention can make various modifications or supplements to the specific embodiments described or replace them in a similar manner, as long as they do not deviate from the structure of the present invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A wear-resistant polyimide film, comprising a main film body, wherein the main film body is a polyimide film; Features: The wear-resistant polyimide film also includes an anti-wear layer and a reinforcement layer; the anti-wear layer is composed of a plurality of first anti-wear particles laid on the surface of the main film body, and each particle of the first anti-wear particles is partially embedded in the surface of the main film body; The reinforcement layer is a photosensitive resin coating, which is coated on the anti-wear layer and the main film body, and the reinforcement layer at least fills the gaps between each of the first anti-wear particles; the reinforcement layer contains a plurality of second anti-wear particles, the particle size of the second anti-wear particles is less than 50% of the first anti-wear particles, and the second anti-wear particles are indium tin oxide powder, which is embedded between the first wear-resistant particles.

2. A wear-resistant polyimide film according to claim 1, Features: The main film body is a colorless polyimide film, and the thickness of the main film body is 10 μm to 200 μm.

3. The wear-resistant polyimide film according to claim 1, Features: A plurality of the first anti-wear particles cover the entire film surface of the main film body; the first anti-wear particles are spherical particles, and the particle size of the first anti-wear particles is between 500 nm and 50 μm.

4. The wear-resistant polyimide film according to claim 1, Features: The difference between the refractive index of the reinforcement layer and the refractive index of the first wear-resistant particles is no more than 0.

15.

5. A wear-resistant polyimide film according to any one of claims 1 to 4, Features: The first anti-wear particles are silicon oxide powder particles.

6. A method for producing a wear-resistant polyimide film, Features The steps include: (1) coating a polyimide precursor solution on a mother board and drying it at a temperature of 80° C. to 150° C. to obtain an uncured main film; (2) spreading the first anti-wear particles on the surface of the main film, and embedding a particle part of each first anti-wear particle into the main film; (3) fully curing the main film at a high temperature of more than 200° C. to form an anti-wear layer composed of a plurality of first anti-wear particles on the film surface of the main film; (4) coating a photosensitive resin coating on the film surface of the main film body, wherein the photosensitive resin coating contains indium tin oxide powder as a second anti-wear particle, and after the photosensitive resin coating and the indium tin oxide powder therein are fully infiltrated or embedded in the gaps between the first anti-wear particles, irradiating ultraviolet light to cure the photosensitive resin coating, thereby forming a reinforcement layer on the anti-wear layer; (5) All material layers attached to the motherboard are peeled off from the motherboard to obtain the wear-resistant polyimide film.

7. The method for producing a wear-resistant polyimide film according to claim 6, Features: In the step (2), an excess amount of first anti-wear particles are spread on the surface of the main film body; after the step (2) or the step (3), the excess particles not embedded in the surface of the main film body are removed by vacuum adsorption or air blowing.

8. The method for manufacturing a wear-resistant polyimide film according to claim 6, Features: In the step (2), pressure is applied to allow the particle body of each first anti-wear particle to be partially embedded into the film surface of the main film body; Alternatively, a powder spraying process is used to spray an airflow carrying first anti-wear particles onto the membrane surface of the main membrane body, and these first anti-wear particles are partially embedded into the membrane surface of the main membrane body under the action of their own momentum.

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