Optical film for reducing interface reflection and preparation method thereof

Abstract

The invention relates to the technical field of optical film preparation, in particular to an optical film capable of reducing interface reflection and a preparation method thereof.Reactive glue capable of reacting with a base material or a thin film is prepared and evenly coated on the surface of the treated thin film or base material, the reactive glue reacts with the base material, and the interface reflection is reduced. Corroding the surface of the base material or the film to form a transition area with gradually changed refractive index, thereby obviously reducing interface reflection; according to the method, firm bonding of the base materials is achieved, interface reflection is remarkably reduced, and the performance of the optical film is improved.

Description

Technical Field

[0001] This invention relates to the field of optical film technology, and more specifically to an optical film for reducing interface reflection and its preparation method. Background Technology

[0002] In the field of optical film technology, interface reflection has always been a key factor affecting the performance of optical systems. Traditional methods such as multilayer film deposition and micro / nano structure fabrication can reduce reflection, but these methods are complex, costly, and difficult to apply on a large scale. Multilayer film deposition (such as alternating deposition of high- and low-refractive-index dielectric films on a substrate using magnetron sputtering) allows light of different wavelengths to reflect and cancel each other out at the film interface, achieving a wide range of low reflection. This method has already been applied to high-end camera lenses and astronomical telescope lenses. However, multilayer film deposition requires extremely precise equipment, and the thickness and refractive index of each layer must be strictly controlled, resulting in complex processes and high production costs. Moreover, the layers are physically bonded together, making them prone to detachment over time due to stress.

[0003] Micro / nano structure fabrication (such as nanoimprinting and photolithography) involves creating nanoscale gratings and moth-eye-shaped textured structures on the surface of optical films. This allows light to be refracted and scattered multiple times within the micro / nano structure, reducing direct reflection. This technology is commonly used in anti-reflective films for mobile phone screens and tablet displays. However, micro / nano structure fabrication requires extremely high precision molds, which are prone to wear during production. This makes it difficult to guarantee yield rates during mass production and also increases costs. Even when using adhesive to bond the optical film to the substrate, traditional adhesives simply "stick" the two together. The significant difference in refractive index between the adhesive and the substrate can actually increase interface reflection. Furthermore, the adhesive and substrate are only physically connected, making them prone to separation over time and resulting in poor durability. Therefore, a new technology is urgently needed to overcome this bottleneck. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention proposes a method for preparing an optical film that reduces interface reflection. A reactive adhesive is prepared that can react with a substrate or thin film. Through the chemical reaction between the reactive adhesive and the substrate, the surface of the substrate or thin film is corroded, forming a transition region with a gradually changing refractive index. This reduces abrupt changes in refractive index at the interface, thereby significantly reducing interface reflection and obtaining an optical film that reduces interface reflection.

[0005] To achieve the purpose of the invention, the following technical solution is provided: This invention provides a method for preparing an optical film that reduces interface reflection. A reactive adhesive that can react with a substrate or film is prepared, the reactive adhesive is uniformly coated on the surface of the treated film or substrate, the treated substrate and film are bonded together, and the surface of the substrate or film is etched using the reactive adhesive to obtain an optical film that reduces interface reflection.

[0006] Furthermore, the reactive adhesive includes a reactive substance selected according to the characteristics of the substrate, wherein the amount of the reactive substance added does not exceed one-fifth of the volume of the adhesive.

[0007] Furthermore, the reactive substance is a solvent that can dissolve the substrate or a solvent that can react with the substrate, preferably hydroxyethyl methacrylate (HEMA) or hydroxyethyl acrylate (HEA).

[0008] Furthermore, the refractive index of the high-performance adhesive matches the refractive index of the substrate, preferably any one of epoxy resin series adhesives, acrylate series adhesives, or silicone adhesives.

[0009] Furthermore, the reactive adhesive also includes antioxidant 1010.

[0010] Furthermore, the substrate treatment method is any one of wiping, soaking, plasma treatment, ultraviolet light irradiation sanding or sandblasting.

[0011] Furthermore, the thin film is processed by any one of UV transfer printing, hot pressing, or photolithography.

[0012] Furthermore, the reactive adhesive is applied to the treated substrate or film surface with a thickness of 1-100µm. The treated film is then bonded to the treated substrate, and pressure is applied and held for 1-300s.

[0013] Furthermore, the adhesive is fully cured by heat curing or ultraviolet curing to ensure bonding.

[0014] The present invention also provides an optical film for reducing interface reflection prepared according to the above preparation method.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: The optical film preparation method provided in this invention application can effectively mitigate the impact of abrupt changes in refractive index. It utilizes a reactive adhesive to react with the substrate, forming a transition region with a gradual change in refractive index, thereby significantly reducing interface reflection. Through microstructural modification, a nanoscale rough structure is constructed on the substrate surface using the corrosive effect of the reactive adhesive, altering the light propagation path and further reducing reflection. This invention method can significantly reduce interface reflection, improve light transmittance, and achieve efficient adhesion, meeting the needs of diverse application scenarios. Furthermore, its process is simple and low-cost, facilitating large-scale industrial production, thus having a wide range of applications and broad market prospects. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the optical film prepared in Example 1, wherein 1 is a thin film PC layer, 2 is reactive adhesive, and 3 is a substrate PC layer; Figure 2A comparison diagram of the signal transmission distance of the optical film prepared in Example 1 and the optical film prepared without pre-reaction treatment to reduce interface reflection. Detailed Implementation

[0017] 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.

[0018] Unless otherwise specified, all raw materials used in the following examples were purchased commercially.

[0019] Unless otherwise specified, the methods used in the following embodiments are conventional operating methods in the art.

[0020] The substrates or films in the following examples include, but are not limited to, polycarbonate (PC), polyethylene terephthalate (PET), triallyl cyanurate (TAC), cyclic olefin polymer (COP), and polymethyl methacrylate (PMMA).

[0021] Example 1 This embodiment provides a method for preparing an optical film that reduces interface reflection, including the following steps: (1) Preparation of reactive adhesive: Pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (antioxidant 1010) was selected as an additive. Hydroxyethyl methacrylate (HEMA) and modified acrylate adhesive were mixed and stirred at a volume ratio of 1:50:1000 until the mixture was uniform and transparent, without obvious layering or particles. In addition, the additives of reactive adhesive can also be plasticizers, dispersants or stabilizers. (2) Pretreatment of the substrate and UV transfer of the film: In this embodiment, PC is selected as the substrate, which can react with the reactive adhesive prepared above and corrode the surface of the substrate; the thicker PC substrate is gently wiped with a lint-free cloth and alcohol, and a nano-grating structure is transferred on a 0.175mm PC film by roll-to-roll using the UV transfer method; in addition, plasma treatment, immersion, ultraviolet light irradiation, sandpaper polishing or sandblasting can also be used to treat the substrate, as long as the substrate cleanliness meets the requirements; the film can also be processed by hot pressing or photolithography to form a nano-grating structure; (3) Drop reactive adhesive onto the surface of PC substrate, then cover it with PC film, press the adhesive to a thickness of 30μm using a glue roller, hold for 1 minute, then increase the pressure of the glue roller and press again, and finally cure by irradiation with ultraviolet light (365nm) for 30 seconds; in addition, the adhesive can also be cured by thermosetting. (4) Cleaning: After the adhesive has completely cured, use a lint-free cloth dampened with a small amount of ethanol to gently wipe the surface of the optical film to remove any residual adhesive residue and impurities that may have remained during the curing process, ensuring the film surface is clean and transparent; the prepared optical film is as follows Figure 1 As shown.

[0022] Example 2 This embodiment provides a method for preparing an optical film to reduce interface reflection, which differs from Embodiment 1 in that: In the preparation of reactive adhesive, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid] (antioxidant 1010) was selected as an additive. Hydroxyethyl acrylate (HEA) and modified acrylate adhesive were mixed and stirred at a volume ratio of 1:25:1000 until the mixture was uniform and transparent, without obvious layering or particles.

[0023] In addition to this embodiment, plasticizers, dispersants or stabilizers can also be added during the preparation of reactive adhesives. These additives can optimize the performance of the adhesive, so that the prepared adhesive can both corrode the substrate surface and ensure the bonding strength.

[0024] Example 3 This embodiment provides a method for preparing an optical film to reduce interface reflection. The difference between this embodiment and Embodiment 1 is that: In the preparation of reactive adhesive, hydroxyethyl methacrylate (HEMA) and modified acrylate adhesive are mixed and stirred at a volume ratio of 50:1000 until the mixture is uniform and transparent, without obvious layering or particles.

[0025] The optical film prepared in Example 1 and the optical film prepared without pre-reaction treatment to reduce interface reflection were tested for signal transmission performance. When the signal intensity reached 500 cd, it could be received by the signal detector. The effective transmission distance of the sample without pre-reaction was 7.8 cm, and the effective transmission distance of the sample with pre-reaction was 15.7 cm. After pre-reaction, the signal transmission distance of the sample was significantly improved.

[0026] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for preparing an optical film to reduce interface reflection, characterized in that, A reactive adhesive capable of reacting with a substrate or film is prepared. The reactive adhesive is uniformly coated on the surface of the treated film or substrate. The treated substrate and film are then bonded together. The surface of the substrate or film is etched using the reactive adhesive to obtain an optical film that reduces interface reflection.

2. The method for preparing an optical film to reduce interface reflection as described in claim 1, characterized in that, The reactive adhesive includes reactive substances and high-performance adhesives selected according to the characteristics of the substrate; the amount of the reactive substances added does not exceed one-fifth of the volume of the adhesive.

3. The method for preparing an optical film to reduce interface reflection as described in claim 2, characterized in that, The reactive substance is a solvent that can dissolve the substrate or react with the substrate, preferably hydroxyethyl methacrylate or hydroxyethyl acrylate.

4. The method for preparing an optical film for reducing interface reflection as described in claim 2, characterized in that, The refractive index of the high-performance adhesive is matched with the refractive index of the substrate, preferably any one of epoxy resin series adhesives, acrylate series adhesives, or silicone adhesives.

5. The method for preparing an optical film to reduce interface reflection as described in claim 2, characterized in that, The reactive adhesive also includes antioxidant 1010.

6. The method for preparing an optical film to reduce interface reflection as described in claim 1, characterized in that, The substrate can be treated by wiping, soaking, plasma treatment, ultraviolet light irradiation, sanding or sandblasting.

7. The method for preparing an optical film to reduce interface reflection as described in claim 1, characterized in that, The thin film can be processed by any one of UV transfer, hot pressing or photolithography.

8. The method for preparing an optical film to reduce interface reflection as described in claim 1, characterized in that, The thickness of the reactive adhesive coating on the treated substrate or film surface is 1-100µm.

9. The method for preparing an optical film to reduce interface reflection as described in claim 1, characterized in that, The adhesive is fully cured by heat curing or UV curing to ensure bonding.

10. An optical film prepared by a method for preparing an optical film to reduce interface reflection as described in any one of claims 1 to 9.

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