A film

Abstract

The present invention provides a film, comprising a transparent substrate layer, the transparent substrate layer includes a first optical surface and a second optical surface, a high-dyne hardening layer and a coating color layer are disposed on the first optical surface, and an optical adjustment layer, a texture adhesive layer and an ink printing layer are disposed on the second optical surface. The film with the above structure plays a decorative role by setting the texture adhesive layer and the coating color layer, and at the same time, the optical adjustment layer provided solves the problem that the texture adhesive layer and the coating color layer are not clear and there are interference fringes.

Description

Technical Field

[0001] The present invention relates to an optical film, and particularly to a protective film for a film. Background Art

[0002] In the future, for 5G millimeter-wave communication and 5G antenna design, the requirements for the materials of mobile phone casings are becoming increasingly stringent. 5G uses millimeter waves and is very sensitive to metals. If a 5G mobile phone uses a metal casing, the signal will be directly blocked. In addition to the limitation of 5G signals, wireless charging is also one of the important reasons for promoting the development of the non-metal back cover market. Wireless charging transmits energy by electromagnetic waves. The transmission of electromagnetic waves cannot be blocked by metals. In other words, there cannot be metal materials shielding in the area of the wireless charging receiver of the mobile phone.

[0003] At present, the main non-metal materials for the back panels of 5G mobile phones are zirconia ceramics, glass, and plastics, and each of the three materials has its own advantages. Among them, the core advantage of ceramics is higher hardness and wear resistance, combined with a warm and jade-like feel and a beautiful and delicate appearance, making it an ideal material for mobile phone casings. However, an important problem faced by ceramics is the high processing difficulty, resulting in high costs and insufficient production capacity. The cost is several times that of glass, and ceramics are also fragile. The greatest advantage of glass lies in its mature technology, abundant production capacity, and low cost. It is also the non-metal material with the fastest increasing penetration rate at present. However, glass materials have inherent deficiencies and are easily scratched, even by just dust or small sand grains. At the same time, mobile phones with glass covers are more likely to slide when placed on an inclined plane due to the small friction. Plastics have poor wear resistance and rigidity, but the lowest cost.

[0004] In the mobile phone field, people have higher pursuits for the color and texture of mobile phone back covers. Especially after the large-scale application of glass and plastics in mobile phones, decorative films appear more and more frequently on mobile phones. From the gradient color matching decoration adopted by the OPPO R series to the Huawei Mate 30, the back cover film laminating process has been continuously bringing new sensory experiences to consumers. Currently, the mainstream decoration methods are divided into two categories: one is to directly create a decorative effect on the glass, and the other is GDF (Glass Deco Film), that is, to create a decorative effect on the film, and then integrate it with the glass back cover through vacuum lamination. Regardless of which decoration method is adopted, when the mobile phone drops or is impacted during use, there is a probability that the glass back cover will burst or break and scatter, and a film is required to avoid the above situation. In the way of directly decorating the glass, a common OCA inner film is used; in the GDF method, not only can texture structures and colors be made on the film sheet to play a decorative role, but also the role of the film can be played. Due to the unreasonable optical structure design of this explosion-proof sheet material, there is a phenomenon of refractive index mismatch between layers and interference fringes, resulting in the defects of color dispersion and unclear patterns of the color protective film, seriously affecting the sensory effect of the mobile phone back cover. Summary of the Invention

[0005] The main object of the present invention is to provide a film, and the film structure solves the problems that not only texture structures and colors can be made on the film sheet for decoration, but also the refractive index mismatch between layers causes interference fringes, resulting in the defects of color dispersion and unclear texture of the color protection film.

[0006] A film includes a transparent substrate layer, the transparent substrate layer includes a first optical surface and a second optical surface, a high-dyne hardening layer and a coating color layer are provided on the first optical surface, and an optical adjustment layer, a texture glue layer and an ink printing layer are provided on the second optical surface.

[0007] Further, the dyne value of the high-dyne hardening layer after curing is greater than 48, and the high-dyne hardening layer can well match the coating color layer.

[0008] Further, the refractive index range of the high-dyne hardening layer is 1.45 - 1.55.

[0009] Further, the thickness range of the transparent substrate layer is 20 - 200 μm. If the thickness is too low, the substrate will be too thin and it is difficult for the existing production process to handle. If the thickness is too high, it will cause difficulties in winding and increase costs. At the same time, too thick a substrate does not conform to the development direction of thin and light mobile phones.

[0010] Further, the thickness range of the high-dyne hardening layer is 0.3 - 10.0 μm, preferably 0.3 μm < thickness < 2.0 μm. If the film thickness is too thin, the hardness cannot be guaranteed. If it is too thick, the price will increase. The preferred range is a range with appropriate cost performance verified through practice.

[0011] Further, the thickness range of the optical adjustment layer is greater than 50 - 250 nm. According to the optical design requirements, this range can maximize the solution of the interference fringe problem, thereby ensuring the color and texture clarity of the color film.

[0012] Further, the refractive index range of the optical adjustment layer is 1.59 - 1.80. If the refractive power is too low, the effect of reducing chromatic aberration and eliminating shadows cannot be achieved. If the refractive power is greater than 1.80, there will be negative impacts such as difficulty in finding raw materials with high refractive power and serious interference fringes.

[0013] Further, the pencil hardness range of the optical adjustment layer is 2B - H. If the hardness is too low, there will be a phenomenon of texture misalignment after the optical adjustment layer is paired with the texture glue layer.

[0014] Further, the thickness range of the coating color layer is 0.1 μm - 1.0 μm, and the required coating thickness is different according to different color coating requirements.

[0015] Further, the thickness range of the ink printing layer is 4 μm - 8 μm. The ink printing layer refers to the printing of a mirror printing layer on the UV glue texture glue layer, and the printing thickness is 4 - 8 μm.

[0016] Beneficial effects:

[0017] On the first optical surface and the second optical surface of the transparent substrate, a high-dyne hardening layer and an optical adjustment layer are respectively coated. The high-dyne hardening layer enables the film to have excellent adhesion to the vapor-deposited color coating layer. At the same time, the provided optical adjustment layer solves the problem of unclear texture glue layer and coating color layer and the presence of interference fringes. Description of the drawings

[0018] Figure 1 Schematic diagram of the film for Example 1, where 1 is the transparent substrate layer, 2 is the optical adjustment layer, 3 is the coating color layer, 4 is the high-dyne hardening layer, 5 is the texture glue layer, and 6 is the ink printing layer. Specific implementation manners

[0019] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the embodiments.

[0020] Example 1

[0021] On the first optical surface of the 50 μm Toray substrate UH4V with a transmittance > 90% and a haze < 1%, Toyo Ink high-dyne glue FP006 is coated to form a high-dyne hardening layer with a thickness of 1.1 μm; on the second optical surface of the UH4V substrate, FS002 high-refractive glue of Japanese ink with a refractive index of 1.65 is coated as the optical adjustment layer, and the thickness of the optical adjustment layer is 120 nm; on the high-dyne hardening layer, a coating color layer is formed by PVD electroplating method, and the thickness of the coating color layer is 0.4 μm; on the optical adjustment layer, a nano-scale texture glue layer is prepared by UV nano-texture technology; on the nano-texture glue layer, an ink printing layer with a thickness of 5 μm is formed, and a 50 μm CPP self-adhesive film is laminated.

[0022] Example 2

[0023] Different from Example 1, the thickness of the high-dyne hardening layer is 0.3 μm.

[0024] Example 3

[0025] Different from Example 1, the thickness of the high-dyne hardening layer is 5.0 μm.

[0026] Example 4

[0027] Different from Example 1, the thickness of the optical adjustment layer is 50 nm.

[0028] Example 5

[0029] Different from Example 1, the thickness of the optical adjustment layer is 250 nm.

[0030] Example 6

[0031] Different from Example 1, the refractive index of the optical adjustment layer is 1.59.

[0032] Example 7

[0033] Different from Example 1, the refractive index of the optical adjustment layer is 1.80.

[0034] Comparative Example 1

[0035] Different from Example 1, no optical adjustment layer is provided on the second optical surface of the transparent substrate layer.

[0036] Comparative Example 2

[0037] Different from Example 1, the surface energy value of the cured hardening layer coated on the first optical surface of the transparent substrate layer is 30.

[0038] Comparative Example 3

[0039] Different from Example 1, the thickness of the high surface energy hardening layer is 12 μm.

[0040] Comparative Example 4

[0041] Different from Example 1, the refractive index of the high surface energy hardening layer is 1.57.

[0042] Comparative Example 5

[0043] Different from Example 1, the refractive index of the optical adjustment layer is 1.52.

[0044] The implementation conditions of the above examples and comparative examples are shown in Table 1, and the test results are shown in Table 2.

[0045] Table 1 Implementation Conditions of Examples and Comparative Examples

[0046]

[0047] Table 2 Test Results of Examples and Comparative Examples

[0048]

[0049]

[0050] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, various modifications and variations can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A film, characterized in that, It includes a transparent substrate layer, the transparent substrate layer comprises a first optical surface and a second optical surface, a high-dyne hardening layer and a coated color layer are provided on the first optical surface, and an optical adjustment layer, a texture glue layer and an ink printing layer are provided on the second optical surface; the refractive index range of the high-dyne hardening layer is 1.45 - 1.55; the thickness range of the optical adjustment layer is 50 - 250 nm; the refractive index range of the optical adjustment layer is 1.59 - 1.80; the pencil hardness range of the optical adjustment layer is 2B - H; the coating raw material of the optical adjustment layer is high-refractive glue; the optical adjustment layer is provided between the transparent substrate layer and the texture glue layer.

2. The film according to claim 1, characterized in that, The dyne value of the high-dyne hardening layer after curing is greater than 48.

3. The film according to claim 1, characterized in that, The thickness range of the transparent substrate layer is 20 - 200 μm.

4. The film according to claim 1, characterized in that, The thickness range of the high-dyne hardening layer is 0.3 - 10.0 μm.

5. The film according to claim 1, characterized in that, The thickness range of the coated color layer is 0.1 μm - 10.0 μm.

6. The film according to claim 1, characterized in that, The thickness range of the ink printing layer is 4 μm - 8 μm.

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