Decorative film and cover plate

Abstract

The present disclosure provides a decorative film and a cover plate, the decorative film comprising a substrate layer and a graphic layer, cloth is soaked in optical glue and laid on the substrate layer to form the graphic layer. By forming a pattern of the graphic layer with cloth, the pattern can have rich colors, and the material cost of forming the pattern can be reduced.

Description

[0001] This invention is a divisional application of the invention patent No. 202110998510.2 filed by the applicant on August 27, 2021, entitled "Decorative film and its preparation method, cover plate". Technical Field

[0002] This disclosure relates to the field of decorative design, specifically to a decorative film and cover plate. Background Technology

[0003] As living standards improve, people have increasingly higher demands for the aesthetic appearance of products. To overcome the limitations of the product's inherent design, decorative films can be applied to enhance its appearance. For example, in the case of mobile phones, a cover with a decorative film not only protects the internal components but also beautifies the phone. A well-designed cover can increase the phone's value, improve the user experience, and expand users' choices in phone design, making the phone more appealing to a wider range of consumers.

[0004] However, current decorative films are limited by their own structural design, resulting in a limited variety of patterns that cannot meet user needs. Moreover, the raw materials used to form patterns are expensive, increasing the manufacturing cost of decorative films. Summary of the Invention

[0005] A first aspect of this disclosure provides a decorative film comprising a graphic layer and an optical adhesive layer adhered to the graphic layer. The graphic layer is located on a substrate layer and configured to be composed of fabric.

[0006] In the above scheme, the pattern of the graphic layer is formed by fabric. With the help of the current mature fabric technology, the pattern can have rich colors. Moreover, the cost of fabric is very small. Compared with the method of forming patterns by expensive materials such as ink, the material cost of forming patterns by fabric is greatly reduced.

[0007] In one specific embodiment of the first aspect of this disclosure, the fabric includes a first line and a second line, which intersect each other to form a pattern. The fabric may be a woven material, thus having a textured pattern unique to woven materials, which is actually a three-dimensional graphic at a microscopic level, thereby presenting a realistic three-dimensional visual effect.

[0008] In one specific embodiment of the first aspect of this disclosure, the decorative film may further include a substrate layer for supporting the graphic layer, the graphic layer being attached to the substrate layer by an optical adhesive layer.

[0009] In one specific embodiment of the first aspect of this disclosure, the material of the optical adhesive layer can be UV adhesive or OCA adhesive.

[0010] In the above scheme, the first sub-optical adhesive layer is formed by UV adhesive, which can make the optical adhesive layer have high strength, thereby protecting the graphic layer.

[0011] In one specific embodiment of the first aspect of this disclosure, the optical adhesive layer may include: a first sub-optical adhesive layer located on the side of the graphic layer opposite to the substrate layer to encapsulate the graphic layer, i.e., optical adhesive is provided on one side of the fabric; or, a first sub-optical adhesive layer and a second sub-optical adhesive layer located on opposite sides of the graphic layer to encapsulate the graphic layer, i.e., optical adhesive is provided on both sides of the fabric.

[0012] In one specific embodiment of the first aspect of this disclosure, the orthographic projection of the graphic layer onto the substrate layer lies within the orthographic projection of the first sub-optical adhesive layer onto the substrate layer. The edge portion of the first sub-optical adhesive layer that does not overlap with the graphic layer contacts the substrate layer.

[0013] Due to its inherent structure, the fabric has limited adhesion strength to the adhesive layer, making it prone to separation. In the above solution, the size of the first sub-optical adhesive layer is larger than that of the graphic layer. After the edge of the first sub-optical adhesive layer is bonded to the substrate layer, a cavity is actually formed between the first sub-optical adhesive layer and the substrate layer, and the graphic layer is located in this cavity. Thus, it is not necessary to attach the fabric to the substrate layer, and displacement or detachment of the graphic layer can be avoided; or, if the fabric is attached to the substrate layer through the adhesive layer, even if the fabric and the substrate layer separate, the graphic layer will not displace or detach because it is constrained in the cavity.

[0014] In another specific embodiment of the first aspect of this disclosure, the decorative film further includes a second sub-optical adhesive layer, which is located between the graphic layer and the substrate layer, and the graphic layer is attached to the substrate layer through the second sub-optical adhesive layer.

[0015] In one specific embodiment of the first aspect of this disclosure, the material of the second sub-optical adhesive layer is UV adhesive or OCA adhesive.

[0016] In another specific embodiment of the first aspect of this disclosure, the decorative film further includes a third sub-optical adhesive layer, which is co-layered with the graphic layer and penetrates into the gaps in the fabric.

[0017] In the above scheme, the third sub-optical adhesive layer penetrates into the gaps in the fabric, which greatly increases the contact area between the third sub-optical adhesive layer and the fabric, and makes the third sub-optical adhesive layer and the fabric interlocked, meaning that the third sub-optical adhesive layer and the graphic layer are difficult to separate. Thus, when a graphic layer is placed on the substrate layer, the risk of graphic layer detachment can be reduced, increasing the reliability of the decorative film.

[0018] In one specific embodiment of the first aspect of this disclosure, the fabric includes a first line and a second line, which intersect each other to form a pattern. The refractive indices of the first line, the second line, and the third sub-optical adhesive layer are all unequal; or the refractive indices and / or colors of the first line and the second line are equal, and the refractive indices of the first line and the third sub-optical adhesive layer are unequal; or the refractive indices and / or colors of the first line and the second line are unequal, and the refractive index of the third sub-optical adhesive layer is set to be equal to the refractive index of one of the first line and the second line.

[0019] In the above scheme, the refractive indices of the first line, the second line, and the third sub-optical adhesive layer are kept equal, which would prevent the graphic layer from displaying the pattern.

[0020] In one specific embodiment of the first aspect of this disclosure, the second sub-optical adhesive layer and the third sub-optical adhesive layer are integrally formed such that there is no physical interface between the second sub-optical adhesive layer and the third sub-optical adhesive layer, and the first sub-optical adhesive layer and the third sub-optical adhesive layer are spaced apart from each other.

[0021] In the above scheme, the second and third sub-optical adhesive layers are integrally formed without a physical interface, meaning that the second and third sub-optical adhesive layers are formed from the same optical adhesive. Thus, the graphic layer is actually immersed (or embedded) in this optical adhesive, eliminating the risk of the graphic layer and the second sub-optical adhesive layer detaching from each other, thereby further reducing the risk of the graphic layer falling off the substrate layer.

[0022] In another specific embodiment of the first aspect of this disclosure, the first sub-optical adhesive layer, the second sub-optical adhesive layer, and the third sub-optical adhesive layer are integrally formed, so that there is no physical interface between the first sub-optical adhesive layer, the second sub-optical adhesive layer, and the third sub-optical adhesive layer.

[0023] In the above scheme, the first sub-optical adhesive layer, the second sub-optical adhesive layer, and the third sub-optical adhesive layer are integrally formed without physical interfaces, meaning that the first, second, and third sub-optical adhesive layers are formed from the same optical adhesive. Thus, the graphic layer is actually immersed (or embedded) in the optical adhesive, eliminating the risk of the graphic layer and the second sub-optical adhesive layer detaching from each other, thereby further reducing the risk of the graphic layer falling off the substrate layer. Furthermore, the absence of a risk of detachment between the graphic layer and the first sub-optical adhesive layer further reduces the risk of other structures (structures adhered to the first sub-optical adhesive layer, such as the optical leather layer described below) falling off the graphic layer.

[0024] In one specific embodiment of the first aspect of this disclosure, the graphic layer is a continuous layer structure; or, the graphic layer includes multiple discrete graphic units.

[0025] In another specific embodiment of the first aspect of this disclosure, the decorative film further includes a coating layer, which is disposed overlapping the graphic layer. The coating layer is configured as a total reflective layer, with the graphic layer and the coating layer arranged sequentially from the visible side of the decorative film to the back side opposite to the visible side; or, the coating layer is configured as a semi-transparent and semi-reflective layer, with the coating layer and the graphic layer arranged sequentially from the visible side of the decorative film to the back side opposite to the visible side.

[0026] In the above scheme, the coating layer can improve the color effect of the pattern in the graphic layer and enhance the visual effect of the decorative film.

[0027] In one specific embodiment of the first aspect of this disclosure, the coating layer is deposited on the surface of the graphic layer; or, the coating layer is deposited on the surface of the first sub-optical adhesive layer opposite to the graphic layer.

[0028] In another specific embodiment of the first aspect of this disclosure, the decorative film further includes at least one texture layer. The texture layer is disposed on one side of the graphic layer or on both sides. For example, the texture layer includes a micro / nanostructure layer and a reflective layer covering the micro / nanostructure layer, the micro / nanostructure layer including multiple protrusions and / or depressions. The reflective layer is located on the side of the micro / nanostructure layer opposite to the graphic layer. The texture layer is located on the side of the substrate layer opposite to the graphic layer, and / or on the side of the first sub-optical adhesive layer opposite to the graphic layer.

[0029] In the above scheme, the texture layer can make the pattern of the graphic layer present as a light and shadow effect or improve the visual three-dimensionality of the decorative film. In another specific embodiment of the first aspect of this disclosure, the decorative film also includes an optical leather layer, which is located on one side of the graphic layer and includes a PU layer or a TPU layer.

[0030] A second aspect of this disclosure provides a method for preparing a decorative film, the method comprising: providing a substrate layer; depositing a fabric on the substrate layer to form a graphic layer; and forming an optical adhesive on the graphic layer, and curing the optical adhesive to form a first sub-optical adhesive layer.

[0031] In another specific embodiment of the second aspect of this disclosure, forming optical adhesive on the graphic layer includes: after placing fabric directly on the substrate layer, applying optical adhesive to the side of the fabric opposite to the substrate layer to form a first sub-optical adhesive layer; or, forming optical adhesive on opposite sides of the fabric to form a first sub-optical adhesive layer and a second sub-optical adhesive layer respectively, and then attaching the graphic layer with the first sub-optical adhesive layer and the second sub-optical adhesive layer adhered thereto to the substrate layer, wherein the second sub-optical adhesive layer is located between the substrate layer and the fabric.

[0032] In another specific embodiment of the second aspect of this disclosure, the decorative film further includes a third sub-optical adhesive layer. The second sub-optical adhesive layer is formed between the graphic layer and the substrate layer. The third sub-optical adhesive layer is co-layered with the graphic layer and penetrates into the gaps in the fabric. Forming the first sub-optical adhesive layer, the second sub-optical adhesive layer, the third sub-optical adhesive layer, and the graphic layer on the substrate layer includes: immersing the graphic layer in optical adhesive; and laying the graphic layer with optical adhesive attached on the substrate layer and curing the optical adhesive. The portion of the optical adhesive located on the graphic layer away from the substrate layer forms the first sub-optical adhesive layer, the portion of the optical adhesive located between the graphic layer and the substrate layer forms the second sub-optical adhesive layer, and the portion of the optical adhesive immersed in the gaps of the graphic layer and co-layered with the graphic layer forms the third sub-optical adhesive layer.

[0033] In another specific embodiment of the second aspect of this disclosure, the optical adhesive is a UV adhesive.

[0034] In another specific embodiment of the second aspect of this disclosure, the preparation method may further include: peeling a substrate layer from the structure formed by the optical adhesive and the fabric.

[0035] A third aspect of this disclosure provides a cover for an electronic product, the cover including the decorative film described in the first aspect above. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of a decorative film provided in an embodiment of the present disclosure.

[0037] Figure 2 This is a schematic diagram of another decorative film provided in an embodiment of the present disclosure, wherein the graphic layer is disposed on the substrate layer through a second sub-optical adhesive layer.

[0038] Figure 3 This is a schematic diagram of another decorative film provided in an embodiment of the present disclosure, wherein a third sub-optical adhesive layer penetrates into the fabric gaps of the graphic layer.

[0039] Figure 4 This is a schematic diagram of another decorative film structure provided in an embodiment of the present disclosure, wherein the graphic layer includes a plurality of discrete graphic units.

[0040] Figure 5 This is a schematic diagram of the structure of a decorative film with a coating layer provided in an embodiment of the present disclosure.

[0041] Figure 6 This is a schematic diagram of another decorative film with a coating layer provided in an embodiment of the present disclosure.

[0042] Figure 7 This is a schematic diagram of the structure of a decorative film with a textured layer provided in an embodiment of the present disclosure.

[0043] Figure 8 This is a schematic diagram of another decorative film with a textured layer provided in an embodiment of the present disclosure.

[0044] Figure 9 This is a schematic diagram of another decorative film with a textured layer provided in an embodiment of the present disclosure.

[0045] Figure 10 This is a schematic diagram of the structure of a decorative film with an optical leather layer provided in an embodiment of the present disclosure. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] In the current production process of decorative films, the graphic layer is usually formed using ink printing and other processes. The process is complex and requires supporting printing equipment, resulting in high production costs. In addition, the use of ink can easily cause pollution. Furthermore, the color richness of the patterns formed by ink printing is limited, and defects such as fading and peeling are prone to occur, making it difficult to meet the needs of users.

[0048] In view of this, embodiments of the present disclosure provide a decorative film and its preparation method, as well as a cover plate, which can solve the above-mentioned problems. The decorative film includes a graphic layer and an optical adhesive layer adhered to the graphic layer. The graphic layer is located on a substrate layer and is configured to be composed of fabric. Forming the graphic layer pattern using fabric allows for rich colors through current mature fabric processing techniques, and the cost of fabric is very low. Compared to forming patterns using expensive materials such as ink, choosing fabric to form patterns significantly reduces material costs.

[0049] For example, in some embodiments of this disclosure, the decorative film may further include a substrate layer for supporting the graphic layer, the graphic layer being attached to the substrate layer by an optical adhesive layer.

[0050] For example, in some other embodiments of this disclosure, the decorative film can be formed using a substrate layer. That is, the various structures of the decorative film are prepared on the substrate layer, and then the substrate layer is peeled off. Thus, the substrate layer structure is absent in the final decorative film, which facilitates a thinner and lighter design and improves the flexibility of the decorative film. In this approach, a release film can be directly disposed on the surface of the substrate layer that supports the decorative film. The decorative film (or a structure composed of fabric and optical adhesive therein) adheres to the release film so as not to damage the decorative film when the substrate layer is peeled off; or the decorative film can be directly attached to the substrate layer using optical adhesive.

[0051] As described above, during the preparation of the decorative film, a substrate layer is required as a supporting structure for the various structures. After the preparation process is completed, the substrate layer can be retained or peeled off. Since the difference between the two types of decorative films lies only in whether or not the substrate layer is retained, in the following embodiments, the decorative film, its preparation method, and the cover plate in this disclosure are described using the example of the final product (decorative film) retaining the substrate layer.

[0052] The structure of the decorative film in the embodiments of this disclosure will now be described with reference to the accompanying drawings. It should be noted that the preparation method of the decorative film is related to its specific structure, and the specific structure of the decorative film differs in different embodiments. Therefore, in these embodiments, the preparation method will be described based on the specific structure.

[0053] like Figure 1 As shown, the decorative film includes a substrate layer 100, a graphic layer 200, and an optical adhesive layer (showing its first sub-optical adhesive layer 310). The graphic layer 200 is formed of fabric and is located between the substrate layer 100 and the first sub-optical adhesive layer 310. The first sub-optical adhesive layer 310 covers the graphic layer 200 to encapsulate the graphic layer 200.

[0054] For example, the substrate layer can be a single layer or composite layer formed from glass, PET (polyethylene terephthalate), PC (polycarbonate), PI (polyimide), CPI (colorless polyimide), PMMA (polymethyl methacrylate), etc.

[0055] For example, the fabric for the graphic layer can be cotton, synthetic fiber, linen, wool, silk, and blended fabrics.

[0056] In some other embodiments of the decorative film provided in this disclosure, the material of the first sub-optical adhesive layer is OCA adhesive.

[0057] In some other embodiments of the decorative film provided in this disclosure, the material of the first sub-optical adhesive layer is a UV adhesive. For example, the first sub-optical adhesive layer is a UV varnish. By forming the first sub-optical adhesive layer with a UV adhesive (e.g., a UV varnish), the first sub-optical adhesive layer can have high strength and good abrasion resistance, thereby protecting the graphic layer.

[0058] Due to its inherent structure, the fabric has limited adhesion strength to the adhesive layer, making it prone to separation from the adhesive layer. This causes the graphic layer to detach from the decorative film, resulting in defects in the decorative film.

[0059] In the decorative film provided in at least one embodiment of this disclosure, the orthographic projection of the graphic layer onto the substrate layer lies within the orthographic projection of the first sub-optical adhesive layer onto the substrate layer. The edge portion of the first sub-optical adhesive layer that does not overlap with the graphic layer contacts the substrate layer. The size of the first sub-optical adhesive layer is larger than the size of the graphic layer. After the edge of the first sub-optical adhesive layer is bonded to the substrate layer, a cavity is actually formed between the first sub-optical adhesive layer and the substrate layer, and the graphic layer is located within this cavity. Thus, it is not necessary to attach the fabric to the substrate layer, and displacement or detachment of the graphic layer can be avoided; or, in the case where the fabric is attached to the substrate layer via the adhesive layer, even if the fabric and the substrate layer separate, the graphic layer will not displace or detach because it is constrained within the cavity. For example, as... Figure 1 As shown, the edge of the first sub-optical adhesive layer 310 is bonded to the substrate layer 100, thereby forming a cavity between the first sub-optical adhesive layer 310 and the substrate layer 100, and the graphic layer 200 fills the cavity.

[0060] For example, Figure 1 The method for preparing the decorative film shown may include: providing a substrate layer 100; laying (or pasting) a graphic layer 200 on the substrate layer 100, wherein the size of the graphic layer 200 is smaller than the size of the substrate layer 100, that is, the orthographic projection of the graphic layer 200 on the surface of the substrate layer 100 facing the graphic layer 200 (designated as the first main surface) lies within the surface, so that the graphic layer 200 does not cover the edge area of ​​the surface; then coating the substrate layer 100 with an optical adhesive (e.g., UV adhesive), which covers the graphic layer 200 and the edge area of ​​the first main surface of the substrate layer 100, thereby making the optical adhesive contact the edge area of ​​the first main surface, thus forming a cavity between the optical adhesive and the substrate layer 100, in which the graphic layer 200 is constrained; and finally, curing the optical adhesive to form a first sub-optical adhesive layer 310.

[0061] In at least one embodiment of the decorative film provided in this disclosure, the decorative film further includes a second sub-optical adhesive layer, which is located between the graphic layer and the substrate layer, and the graphic layer is attached to the substrate layer through the second sub-optical adhesive layer. For example, as shown... Figure 2As shown, the graphic layer 100 is adhered to the substrate layer 100 via the second sub-optical adhesive layer 320. For example, the graphic layer 100 and the second sub-optical adhesive layer 320 are substantially equal in size and overlap each other, that is, the orthographic projection of the graphic layer 100 on the substrate layer 100 and the orthographic projection of the second sub-optical adhesive layer 320 on the substrate layer 100 coincide.

[0062] In the decorative film provided in at least one embodiment of this disclosure, such as Figure 2 The material of the second sub-optical adhesive layer 320 shown can be UV adhesive or OCA adhesive.

[0063] For example, Figure 2 The method for preparing the decorative film shown may include: providing a substrate layer 100; coating the substrate layer 100 with optical adhesive to form a second sub-optical adhesive layer 320; then laying a graphic layer 200 on the second sub-optical adhesive layer 320; and finally coating the graphic layer 200 with optical adhesive to form a first sub-optical adhesive layer 310. For example, the first sub-optical adhesive layer 310 may be a UV adhesive, which may be a UV varnish to serve as the surface of the decorative film after curing, or it may be used to bond other structures (such as the coating layer in the following embodiments) before curing.

[0064] In at least one embodiment of the decorative film provided in this disclosure, the decorative film further includes a third sub-optical adhesive layer, which is co-layered with the graphic layer and penetrates into the gaps in the fabric. The penetration of the third sub-optical adhesive layer into the gaps in the fabric significantly increases the contact area between the third sub-optical adhesive layer and the fabric, making them interlocked and difficult to separate. Thus, when the graphic layer is disposed on the substrate layer, the risk of graphic layer detachment can be reduced, increasing the reliability of the decorative film. For example, as... Figure 3 As shown, the third sub-optical adhesive layer 330 is located in the gaps of the fabric of the graphic layer 200, thus being on the same layer as the graphic layer 200. In this way, the third sub-optical adhesive layer 330 and the fabric of the graphic layer 200 are interlocked, and even if the interface between the fabric of the graphic layer 200 and the third sub-optical adhesive layer 330 separates, there is no risk of them detaching from each other because they are interlocked. Compared to the adhesive strength between the optical adhesive and the fabric, the adhesive strength between optical adhesives is stronger; that is, it is difficult to separate the first optical adhesive 310 and the third sub-optical adhesive layer 330, and the second optical adhesive 320 and the third sub-optical adhesive layer 330, which is equivalent to the graphic layer 200 being difficult to detach.

[0065] In the decorative film provided in at least one embodiment of this disclosure, the fabric includes a first line and a second line, which intersect each other to form a pattern. The refractive indices of the first line, the second line, and the third sub-optical adhesive layer are all unequal; or the refractive indices and / or colors of the first and second lines are equal, and the refractive indices of the first line and the third sub-optical adhesive layer are unequal; or the refractive indices and / or colors of the first and second lines are unequal, and the refractive index of the third sub-optical adhesive layer is set to be equal to the refractive index of one of the first and second lines. This avoids the situation where the refractive indices of the first line, the second line, and the third sub-optical adhesive layer are equal, which would prevent the graphic layer from displaying the pattern.

[0066] For example, such as Figure 3 As shown, the fabric of the graphic layer 200 is woven from a first line extending in a first direction (designated as warp) and a second line extending in a second direction (designated as weft). The first and second directions intersect and are both parallel to the surface of the substrate layer 100 (the main surface used to support the graphic layer 200). When the refractive indices of the first line, the second line, and the third sub-optical adhesive layer 330 are not equal, or when the refractive indices and / or colors of the first and second lines are equal, but the refractive indices of the first line and the third sub-optical adhesive layer 330 are not equal, the placement of the third sub-optical adhesive layer 330 will not affect the pattern of the fabric. When the refractive indices and / or colors of the first and second lines are not equal, and the refractive index of the third sub-optical adhesive layer 330 is set to be equal to the refractive index of the first line, after the third sub-optical adhesive layer 330 is placed, the graphic layer 200 will display a pattern formed by the second line. That is, the placement of the third sub-optical adhesive layer 330 can change the pattern of the fabric in the graphic layer 200 to obtain a new pattern. It should be noted that because the first and second lines are interwoven to form a pattern, there are gaps between them, and the first and second lines are defined only by direction; that is, different first lines may have different colors, and the colors of the first and second lines may be different or the same. Therefore, even if the refractive indices and / or colors of the first and second lines are equal, a pattern can still be formed between the first and second lines. Furthermore... Figure 3 The warp and weft threads are only used to show that the fabric of the graphic layer 200 is woven from lines and to indicate the position of the fabric layer of the graphic layer 200. The actual arrangement direction of the warp and weft threads is as described in the above embodiment.

[0067] In embodiments of this disclosure, when a third sub-optical adhesive layer is provided, the third sub-optical adhesive layer can be integrally formed with the adhesive layer of the adjacent layer, thereby improving the stability of the image layer and reducing the risk of image layer detachment. In embodiments of this disclosure, "integral forming" means that the related structures are made of the same material and are formed by the same fabrication process.

[0068] For example, in the decorative film provided in at least one embodiment of this disclosure, the first sub-optical adhesive layer, the second sub-optical adhesive layer, and the third sub-optical adhesive layer are integrally formed, so that there is no physical interface between the first sub-optical adhesive layer, the second sub-optical adhesive layer, and the third sub-optical adhesive layer. Thus, the first sub-optical adhesive layer, the second sub-optical adhesive layer, and the third sub-optical adhesive layer being integrally formed without physical interfaces means that the first sub-optical adhesive layer, the second sub-optical adhesive layer, and the third sub-optical adhesive layer are formed from the same optical adhesive. Therefore, the graphic layer is actually immersed (or understood as embedded) in the optical adhesive, and there is no risk of the graphic layer and the second sub-optical adhesive layer detaching from each other, thereby further reducing the risk of the graphic layer detaching from the substrate layer; furthermore, there is no risk of the graphic layer and the first sub-optical adhesive layer detaching from each other, thereby further reducing the risk of other structures (structures adhered to the first sub-optical adhesive layer, such as the optical leather layer described below) detaching from the graphic layer. For example, as... Figure 3 As shown, the first sub-optical adhesive layer 310, the second sub-optical adhesive layer 320 and the third sub-optical adhesive layer 330 are integrally formed. For example, the first sub-optical adhesive layer 310, the second sub-optical adhesive layer 320 and the third sub-optical adhesive layer 330 are formed by curing (e.g., UV curing) the same optical adhesive (e.g., UV adhesive).

[0069] For example, Figure 3 The method for preparing the decorative film shown may include: immersing the graphic layer 200 in optical adhesive; after the optical adhesive has penetrated the gaps in the fabric of the graphic layer 200, removing the graphic layer 200 and laying it on the substrate layer 100. Because the graphic layer 200 has optical adhesive inside and on both main surfaces after being immersed in optical adhesive, when the graphic layer 200 is laid on the substrate layer 100, the graphic layer 200 has optical adhesive inside, on the main surface facing away from the substrate layer 100, and on the main surface away from the substrate layer 100. After the optical adhesive cures, the optical adhesive inside the graphic layer 200 forms a third sub-optical adhesive layer 330, the optical adhesive between the graphic layer 200 and the substrate layer 100 forms a second sub-optical adhesive layer 320, and the optical adhesive on the main surface of the graphic layer 200 away from the substrate layer 100 forms a first sub-optical adhesive layer 310.

[0070] In the decorative film provided in at least one embodiment of this disclosure, the second sub-optical adhesive layer and the third sub-optical adhesive layer are integrally formed such that there is no physical interface between the second and third sub-optical adhesive layers, while the first and third sub-optical adhesive layers are spaced apart from each other. The integral formation of the second and third sub-optical adhesive layers without a physical interface means that the second and third sub-optical adhesive layers are formed from the same optical adhesive. Thus, the graphic layer is actually immersed (or understood as embedded) in the optical adhesive, and there is no risk of the graphic layer and the second sub-optical adhesive layer detaching from each other, thereby further reducing the risk of the graphic layer detaching from the substrate layer. For example, as shown... Figure 5 As shown, the second sub-optical adhesive layer 320 and the third sub-optical adhesive layer 330 are integrally formed, while the first sub-optical adhesive layer 310 and the third sub-optical adhesive layer 330 are spaced apart from each other. For example, other structures (such as the coating layer 400 in the following embodiments) may be provided on the surface of the graphic layer 200, and the first sub-optical adhesive layer 310 is used to cover the coating layer 400 as a protective layer, or to adhere other film layers (such as the texture layer in the following embodiments) to the other structure. For example, the second sub-optical adhesive layer 320 and the third sub-optical adhesive layer 330 are formed by curing (e.g., UV curing) the same optical adhesive (e.g., UV adhesive).

[0071] It should be noted that fabrics have numerous internal gaps. Therefore, when simply forming a first or second optical adhesive layer on the fabric, due to the fluidity of the optical adhesive, some of it will penetrate into the fabric during the coating process, resulting in a tight bond between the fabric and the substrate layer. However, in some fabrics, the gap sizes vary, limiting the penetration of the optical adhesive. Furthermore, the penetration depth may differ at different locations within the fabric. Additionally, gaps (e.g., air) may form between the fabric and the optical adhesive within the fabric layer, introducing new differences in refractive index and interfering with the optical effect of the fabric displaying the pattern. In the solution disclosed above, forming the optical adhesive on the fabric through immersion allows the optical adhesive to fully fill the gaps in the fabric, thereby eliminating the problem of refractive index differences caused by these gaps.

[0072] For example, Figure 5The method for preparing the decorative film may include: immersing a graphic layer 200 (e.g., having other structures disposed thereon, such as a coating layer) in an optical adhesive; after the optical adhesive has penetrated the gaps in the fabric of the graphic layer 200, removing the graphic layer 200 and laying it on the substrate layer 100. Because the graphic layer 200 has optical adhesive inside and on one side of its main surface after being immersed in the optical adhesive, when the graphic layer 200 is laid on the substrate layer 100, both the inside of the graphic layer 200 and its main surface facing the substrate layer 100 have optical adhesive. After the optical adhesive cures, the optical adhesive inside the graphic layer 200 forms a third sub-optical adhesive layer 330, and the optical adhesive between the graphic layer 200 and the substrate layer 100 forms a second sub-optical adhesive layer 320. For example, optical adhesive may also adhere to the surfaces of other structures disposed on the graphic layer 200, and after curing, this optical adhesive will form a first sub-optical adhesive layer 310. It should be noted that, in this embodiment, after laying the graphic layer 200 on the substrate layer 100, the other structures mentioned above can be adhered to the graphic layer 200, and then optical adhesive can be separately coated on the other structures to form the first sub-optical adhesive layer 310.

[0073] In some embodiments of the decorative film provided in this disclosure, the graphic layer can be optionally configured as a continuous layer structure, as detailed in the following examples. Figure 2 The illustrated embodiment. It should be noted that a continuous layer structure means that the layer structure is a single, integral structure without any gaps or openings or similar designs.

[0074] In other embodiments of the decorative film provided in this disclosure, the graphic layer may be optionally configured to have a plurality of discrete graphic units. These graphic units may be fragments of fabric. For example, Figure 4 As shown, multiple graphic elements 210 are arranged randomly. For example, the graphic elements 210 may be arranged randomly only in the planar direction (the direction parallel to the surface of the substrate layer), that is, the orthographic projection of the graphic elements 210 onto the surface of the substrate layer 100 is randomly arranged; or, the graphic elements 210 may be arranged randomly not only in the planar direction but also in the cross-sectional direction, that is, the orthographic projection of the graphic elements 210 onto the surface of the substrate layer 100 is randomly arranged, and in the direction perpendicular to the surface of the substrate layer 100, the different graphic elements 210 have different heights from the substrate layer 100.

[0075] For example, in one scenario, a user might require decorative film with floral or other patterns. This typically involves designing multiple pattern arrangements, making the process complex. Figure 4In the illustrated embodiment, a floral pattern can be obtained simply by shredding the fabric into multiple fragments and mixing these fragments with optical adhesive to coat the substrate layer. No specific design is required for the pattern's distribution, which helps reduce costs. Furthermore, in floral pattern applications, users may require each decorative film to have a unique pattern; that is, no two decorative films should have completely identical patterns. In cases where the graphic layer is a continuous structural layer, the pattern needs to be designed to present a distributed pattern, meaning the number of pattern distribution types is determined by the design quantity. At least, decorative films produced in the same batch should still have the same pattern shape, which clearly does not meet the user's aforementioned requirements. In this disclosure as... Figure 4 In the illustrated embodiment, the distribution of multiple fragments of the shredded fabric when mixed with the optical adhesive is random, resulting in completely randomly scattered fragments on the substrate layer. This makes the probability of producing decorative films with identical patterns infinitely close to zero, thereby meeting the user's aforementioned requirements.

[0076] In at least one embodiment of the decorative film provided in this disclosure, the decorative film further includes a coating layer, which is overlapped with the graphic layer. The coating layer is configured as a total reflective layer, with the graphic layer and the coating layer arranged sequentially from the visible side of the decorative film to the back side opposite to the visible side; alternatively, the coating layer is configured as a semi-transparent, semi-reflective layer, with the coating layer and the graphic layer arranged sequentially from the visible side of the decorative film to the back side opposite to the visible side. The coating layer can improve the color effect of the pattern in the graphic layer, thereby enhancing the visual effect of the decorative film. For example, as... Figure 5 As shown, the coating layer 400 is located on the side of the graphic layer 200 facing away from the substrate layer 100. If the side of the graphic layer 200 facing the substrate layer 100 is used to present a pattern to the user, the coating layer 400 can be designed as a total reflection layer so that all external light entering the decorative film can be reflected and used to display the pattern of the graphic layer 200, thereby increasing the brightness and making the colors of the pattern presented by the decorative film more vibrant. Conversely, if the side of the graphic layer 200 facing away from the substrate layer 100 is used to present a pattern to the user, the coating layer 400 can be designed as a semi-transparent and semi-reflective layer so that external light entering the decorative film can pass through the coating layer to the graphic layer 200, and these rays can be reflected and emitted again from the coating layer 400 to display the pattern of the graphic layer 200.

[0077] In some embodiments of the decorative film disclosed herein, the coating layer is deposited on the surface of the graphic layer. This allows the coating layer and the graphic layer to be simultaneously deposited on the substrate layer, reducing the number of steps in the decorative film manufacturing process. Furthermore, by depositing the coating layer on the graphic layer, the risk of the coating layer detaching from the graphic layer (fabric) can be reduced. For example, as... Figure 5As shown, the coating layer 400 is located on the surface of the graphic layer 200 opposite to the substrate layer 100, and the first sub-optical adhesive layer 310 is located on the side of the coating layer 400 opposite to the substrate layer 100.

[0078] For example, the material of the coating layer 400 can be an element, a metal oxide, a non-metal oxide, or an organic material. The method of depositing the coating layer 400 on the substrate layer 100 can include vapor deposition, sputtering deposition, ion plating, electroplating, etc.

[0079] In other embodiments of the decorative film provided in this disclosure, the coating layer is deposited on the surface of the first sub-optical adhesive layer opposite to the pattern layer. In this way, the first and third sub-optical adhesive layers can still be integrally formed, thereby increasing the overall stability of the decorative film and reducing the risk of film layer separation. For example, as... Figure 6 As shown, the coating layer 400 is located on the surface of the graphic layer 200 opposite to the substrate layer 100, and the first sub-optical adhesive layer 310 is located on the side of the coating layer 400 opposite to the substrate layer 100.

[0080] In at least one embodiment of the decorative film provided in this disclosure, the decorative film further includes at least one textured layer. The textured layer includes a micro / nanostructure layer and a reflective layer covering the micro / nanostructure layer, the micro / nanostructure layer including multiple protrusions and / or depressions. The reflective layer is located on the side of the micro / nanostructure layer opposite to the graphic layer. The at least one textured layer may be disposed on one side of the graphic layer or on both sides, for example, the textured layer may be located on the side of the substrate layer opposite to the graphic layer, and / or on the side of the first sub-optical adhesive layer opposite to the graphic layer.

[0081] In one example of this disclosure, such as Figure 7 As shown, the texture layer 500 is located on the side of the first sub-optical adhesive layer 310 opposite to the image layer 200; or, as... Figure 8 As shown, the texture layer 500 is located on the side of the substrate layer 100 opposite to the graphic layer 200. The texture layer 500 includes a micro / nano structure layer 510 and a reflective layer 520 covering the micro / nano structure layer 510. The micro / nano structure layer 510 includes multiple protrusions. The micro / nano structure layer 510 has the effects of refraction and reflection of light, which enables optical layers of the decorative film, such as the graphic layer 200 and the coating layer, to present optical effects, such as brightening, light and shadow, and bright texture, thereby improving the decorative effect of the decorative film.

[0082] In another example of this disclosure, such as Figure 9As shown, the decorative film may include two texture layers 500 and 500', located on both sides of the graphic layer 200. The texture layers 500 and 500' include micro / nano structure layers 510 and 510', and reflective layers 520 and 520' covering the micro / nano structure layers 510 and 510'. The micro / nano structure layer 510 includes multiple protrusions, and the micro / nano structure layer 510' includes multiple depressions. The protrusions and depressions respectively present optical effects or overlap to form optical effects such as light and shadow textures and interference textures. Combined with the graphic layer 200, they have a better decorative effect and are more easily recognizable. For example, in some embodiments, the two texture layers 500 and 500' are disposed on the same side of the graphic layer 200. In this case, only one reflective layer can be disposed, that is, the two micro / nano structure layers share one reflective layer.

[0083] For example, the cross-sectional shapes of the protrusions or depressions of the micro / nano structure layer 510 include arcs, quadrilaterals, triangles, polygons, irregular shapes, etc. Specifically, the protrusions or depressions are semicircles or minor arcs, etc.; or, the protrusions or depressions are quadrilaterals such as squares, rectangles, trapezoids, or polygons such as pentagons and hexagons; or, the protrusions or depressions are irregular shapes, such as quadrilaterals with curved sides and straight sides.

[0084] For example, the protrusions or depressions of the micro-nano structure layer 510 can be arranged to make the pattern of the decorative film present optical effects such as light and shadow, bright texture, 2.5D, and 3D. For details, please refer to the relevant designs of the micro-nano structure layer in the current decorative films, which will not be elaborated here.

[0085] In at least one embodiment of the decorative film provided in this disclosure, a coloring layer is further included, which serves to both prime and color the film. For example, please refer to... Figure 9 and Figure 10 As shown, a coloring layer 700 is provided on the side of the substrate layer 100 opposite to the graphic layer 200. The coloring layer 700 can be a dark ink layer, such as black, gray, or brown. When the decorative film is applied to the cover of an electronic device, the coloring layer is located at the bottom layer to shield the inside of the electronic device and can also provide auxiliary color to the graphic layer, reflective layer, etc.

[0086] In at least one embodiment of the decorative film provided in this disclosure, the decorative film further includes an optical leather layer, which is located on the side of the first sub-optical adhesive layer opposite to the graphic layer. For example, as... Figure 10As shown, the optical leather layer 600 is located on the side of the first sub-optical adhesive layer 310 opposite to the graphic layer 200. The optical leather layer 600 may include artificial leather and / or synthetic leather. For example, the optical leather layer 600 may include an embossed leather layer, and may further include an auxiliary leather layer. The material of the embossed leather layer may be PU resin; for example, PU resin may be coated on the first sub-optical adhesive layer before embossing to form the embossed leather layer. The material of the auxiliary leather layer may be PU, PVC, or TPU, etc., used to increase elasticity, enhance the leather feel of the embossed leather layer, and increase the stretchability of the optical leather layer.

[0087] In a specific example of this disclosure, such as Figure 10 As shown, the decorative film includes an optical leather layer 600 and a texture layer 500, which are located on opposite sides of the graphic layer 200. Therefore, the decorative film comprises an optical leather layer 600, a graphic layer 200, a substrate layer 100, a texture layer 200, and a coloring layer 700 stacked together. The optical leather layer 600, located on the visible side, provides a leather-like appearance and feel, the texture layer 500 provides light and shadow effects, and the graphic layer 200 provides fabric texture and feel. These elements complement each other, resulting in a good decorative effect and high recognizability. In some other embodiments, the optical leather layer 600 and the texture layer 500 may also be disposed on the same side of the graphic layer.

[0088] For example, the optical leather layer may also include the coating layer, texture layer, and other structures mentioned in the above embodiments. For example, the optical leather layer may further include conductive layer, foaming layer, and wear-resistant layer to increase the tactile feel and protective strength of the decorative film, and enable the decorative film to have functions such as touch control, antenna, heating, lighting, and shielding, so that the decorative film can better meet market demands. For details, please refer to the specific structural design of current optical leather, which will not be elaborated here.

[0089] At least one embodiment of this disclosure provides a method for preparing a decorative film, the method comprising: providing a substrate layer; depositing a fabric on the substrate layer to form a graphic layer; and forming an optical adhesive on the graphic layer, and curing the optical adhesive to form an optical adhesive layer.

[0090] In a method for preparing a decorative film according to at least one embodiment of this disclosure, forming an optical adhesive on the graphic layer includes: directly placing a fabric on a substrate layer, then coating an optical adhesive on the side of the fabric facing away from the substrate layer to form a first sub-optical adhesive layer; or, forming optical adhesive on opposite sides of the fabric to form a first sub-optical adhesive layer and a second sub-optical adhesive layer respectively, and then attaching the graphic layer with the first and second sub-optical adhesive layers adhered to it to the substrate layer, wherein the second sub-optical adhesive layer is located between the substrate layer and the fabric. In the decorative film obtained by the above preparation method, the pattern of the graphic layer is formed by the fabric, which allows for rich colors through current mature fabric processing technology, and the cost of the fabric is very low. Compared with forming patterns using expensive materials such as ink, choosing fabric to form patterns significantly reduces material costs. The structure of the decorative film obtained by the above preparation method can be found in the relevant descriptions in the foregoing embodiments, and will not be repeated here.

[0091] In a method for preparing a decorative film according to at least one embodiment of this disclosure, the decorative film further includes a third sub-optical adhesive layer. A second sub-optical adhesive layer is formed between the graphic layer and the substrate layer. The third sub-optical adhesive layer is co-layered with the graphic layer and penetrates into the gaps in the fabric. Forming the first, second, third, and graphic layers on the substrate layer includes: immersing the graphic layer in optical adhesive; and laying the graphic layer with optical adhesive attached onto the substrate layer and curing the optical adhesive. The portion of the optical adhesive located on the graphic layer away from the substrate layer forms the first sub-optical adhesive layer, the portion of the optical adhesive located between the graphic layer and the substrate layer forms the second sub-optical adhesive layer, and the portion of the optical adhesive immersed in the gaps of the graphic layer and co-layered with the graphic layer forms the third sub-optical adhesive layer. The structure and technical effects of the decorative film obtained by the above preparation method can be found in the foregoing... Figure 3 The relevant descriptions in the related embodiments will not be repeated here.

[0092] At least one embodiment of this disclosure provides a cover plate for electronic products, the cover plate including the decorative film of any of the above embodiments. The cover plate, after having the decorative film, can present optical effects such as light and shadow, bright textures, 2.5D, and 3D, resulting in high recognizability and good decorative effect. For example, this cover plate can be applied in the decorative field, and can serve as the outer packaging, casing of home appliances, electronic devices, etc., such as serving as a cover plate (part of the casing) for display products like mobile phone covers (e.g., back covers).

[0093] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A decorative film applied to the cover plate of electronic products, characterized in that, It includes: Substrate layer; The graphic layer is formed by soaking fabric in optical adhesive and laying it on the substrate layer. The pattern of the graphic layer is formed by setting the warp and weft threads of the fabric and the color and / or refractive index of the optical adhesive located between the warp and weft threads; a cavity is formed between the optical adhesive and the substrate layer, and the graphic layer is located in the cavity; The fabric has a woven structure, which includes a first line and a second line that intersect each other; the first line, the second line and the optical adhesive filling the gaps between them have different refractive indices, and the pattern of the graphic layer is formed by the difference in their refractive indices and colors. A coating layer, stacked on top of the graphic layer, is used to enhance the brightness of the pattern and make the colors more vibrant; the coating layer is configured as a total reflective layer or a semi-transparent and semi-reflective layer. The optical adhesive is either a UV adhesive or an OCA adhesive; The micro / nano structure layer includes multiple protrusions and / or depressions, which enable the graphic layer to exhibit optical effects.

2. The decorative film according to claim 1, characterized in that, The fabric includes a first line and a second line, which intersect each other to form a pattern.

3. The decorative film according to claim 2, characterized in that, The refractive indices of the first line, the second line, and the optical adhesive are not equal.

4. The decorative film according to claim 2, characterized in that, The refractive index of the optical adhesive is set to be equal to that of one of the first and second lines.

5. The decorative film according to claim 1, characterized in that, The image layer is a continuous layer structure; or the image layer includes multiple discrete image units.

6. The decorative film according to claim 1, characterized in that, The image layer comprises multiple discrete image units, which are arranged randomly.

7. The decorative film according to claim 1, characterized in that, The fabric is shredded into multiple fragments, which are then mixed with the optical adhesive and coated onto the substrate layer.

8. The decorative film according to claim 1, characterized in that, The coating layer overlaps with the graphic layer; Wherein, the coating layer is configured as a total reflection layer, and the graphic layer and the coating layer are arranged sequentially from the visible side of the decorative film to the back side opposite to the visible side; or The coating layer is configured as a semi-transparent and semi-reflective layer, extending from the visible side of the decorative film to the back side opposite to the visible side, with the coating layer and the graphic layer arranged sequentially or the graphic layer and the coating layer arranged sequentially.

9. The decorative film according to claim 1, characterized in that, At least one texture layer, including a micro / nanostructure layer and a reflective layer covering the micro / nanostructure layer, the micro / nanostructure layer including a plurality of protrusions and / or depressions; The at least one texture layer is disposed on one side of the graphic layer or on both sides.

10. A cover plate for electronic products, characterized in that, The decorative film included in any one of claims 1-9.

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