Optical film with low rough surface

Abstract

The utility model discloses an optical film with a low rough surface, which comprises a base layer provided with an outer base layer and an inner base layer which are overlapped with each other; the first surface of the outer base layer is a concave-convex surface; the second surface of the inner base layer is a concave-convex surface or a plane; the core layer is clamped between the outer base layer and the inner base layer and is in concave-convex fit with the first surface and the second surface; the smooth layer is arranged on a third surface, opposite to the first surface, of the outer base layer in the layer thickness direction; the refractive index of the smooth layer is smaller than or equal to that of the base layer, and the refractive index of the core layer is larger than that of the base layer. The low-rough-surface optical film is reasonable in structure, reflected light is subjected to diffuse reflection through the concave-convex face of the outer base layer, transmission light is refracted through the core layer, the light transmittance is improved, the problem that the reflected light causes unclear display content or affects the sight line is solved, and meanwhile it is guaranteed that patterns are clear and the view field is wide; the arrangement of the smooth layer reduces the surface roughness of the optical film and reduces low-molecular precipitates in the base layer.

Description

Technical Field

[0001] The utility model relates to the technical field of films, in particular to an optical film with low roughness surface. Background Art

[0002] Electronic display screens are often unable to see the displayed content clearly due to the reflection of scenery outside the screen or light on the screen surface; the windshield of a vehicle also affects the driver's field of vision clarity and the sight of oncoming drivers due to the reflection of external light, which can easily lead to safety accidents and visual fatigue.

[0003] The conventional method is to form a concave-convex structure on the surface of a transparent base film, such as coating a resin dispersed with micrometer and / or nanometer particles on a base material to form a fine concave-convex structure. The particles are easy to settle during the coating process and it is difficult to form a convex surface. The setting of a convex surface is easy to cause water accumulation on the window film, which not only affects the line of sight, but also the gathering of water droplets after rain will cause the problem of focusing and easily burning the film surface.

[0004] Therefore, it is necessary to improve the optical film in the prior art. Utility Model Content

[0005] The purpose of the utility model is to overcome the defects existing in the prior art and provide an optical film with a low roughness surface, which diffusely reflects the reflected light through the concave and convex surface of the outer base layer, and refracts the transmitted light through the core layer to increase the transmittance of the light, thereby solving the problem that the reflected light causes unclear display content or affects the line of sight, while ensuring the clarity of the graphics and the wide field of vision; the provision of the smoothing layer reduces the surface roughness of the optical film and reduces the low-molecular precipitates in the base layer.

[0006] In order to achieve the above technical effects, the technical solution of the utility model is: a low-roughness surface optical film, comprising:

[0007] A base layer, having an outer base layer and an inner base layer stacked on top of each other;

[0008] The first surface of the outer base layer is a concave-convex surface;

[0009] The second surface of the inner base layer is a concave-convex surface or a flat surface;

[0010] A core layer, sandwiched between the outer base layer and the inner base layer, and matched with the first surface and the second surface in a concave-convex manner;

[0011] A smoothing layer is provided on a third surface of the outer base layer which is opposite to the first surface along a layer thickness direction;

[0012] The refractive index of the smooth layer is less than or equal to the refractive index of the base layer, and the refractive index of the core layer is greater than the refractive index of the base layer.

[0013] Preferably, the depressions and protrusions of the concave-convex surface of the first surface and the concave-convex surface of the second surface correspond to each other one by one and are in concave-convex fit.

[0014] Preferably, the core layer is made of zirconia or titanium dioxide material.

[0015] Preferably, the smooth layer includes a smooth outer layer and a bend-resistant inner layer. The material of the smooth outer layer is a modified epoxy resin coating, and the material of the bend-resistant inner layer is a polyurethane coating.

[0016] Preferably, the material of the base layer is PET.

[0017] Preferably, a high-temperature resistant adhesive layer is provided on the fourth surface of the inner base layer opposite to the second surface along the layer thickness direction.

[0018] Preferably, the material of the high-temperature resistant adhesive layer is an acrylic pressure-sensitive adhesive layer or an OCA optical adhesive layer.

[0019] Preferably, the layer thickness of the core layer is 30 - 50 nm.

[0020] Preferably, the layer thickness of the smooth layer is 0.2 - 0.6 μm.

[0021] Preferably, an antistatic release film is provided on the surface of the high-temperature resistant adhesive layer away from the base layer, and a protective film is provided on the surface of the smooth layer away from the base layer.

[0022] The advantages and beneficial effects of the present utility model are as follows:

[0023] The low-roughness surface optical film diffuses the reflected light through the concave-convex surface of the outer base layer, and the transmitted light passes through the refraction of the core layer to improve the light transmittance, solving the problem that the reflected light causes unclear display content or affects the line of sight, and at the same time ensuring the clarity of the pattern and the wide field of view;

[0024] The setting of the smooth layer not only optimizes the surface roughness of the optical film, but also prevents the precipitation of low-molecular precipitates from the base layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a schematic structural diagram of Embodiment 1 of the low-roughness surface optical film of the present utility model;

[0026] Figure 2 is a schematic structural diagram of Embodiment 2 of the low-roughness surface optical film of the present utility model.

[0027] In the figure: 1. Base layer; 2. Smooth layer; 3. High-temperature resistant adhesive layer; 4. Protective film; 5. Anti-static release film; 10. Core layer; 101. First surface; 102. Second surface; 21. Smooth outer layer; 21. Bend-resistant inner layer. Detailed implementation manners

[0028] The following combines the accompanying drawings and embodiments to further describe the detailed implementation manners of the present utility model. The following embodiments are only used to more clearly illustrate the technical solutions of the present utility model, and cannot be used to limit the protection scope of the present utility model.

[0029] The "outer layer", "inner layer", "core layer", "inner", and "outer" are referenced based on the normal use state of the low-roughness surface optical film, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present utility model.

[0030] In addition, terms such as "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present utility model, unless otherwise stated, the meaning of "a plurality" is two or more.

[0031] A low-roughness surface optical film disclosed by the present utility model includes a base layer 1, a core layer 10, and a smooth layer 2. The base layer 1 has an outer base layer 11 and an inner base layer 12 that overlap; the first surface 101 of the outer base layer 11 is an uneven surface; the second surface 102 of the inner base layer 12 is an uneven surface or a flat surface; the core layer 10 is sandwiched between the outer base layer 11 and the inner base layer 12 and is unevenly matched with the first surface 101 and the second surface 102; the smooth layer 2 is disposed on the third surface (not marked) of the outer base layer opposite to the first surface 101 along the layer thickness direction; the refractive indices of the base layer 1 and the smooth layer 2 are the same, and the refractive index of the core layer 10 is greater than that of the base layer 1.

[0032] Principle of use: The outer base layer 11 faces the outside world. Incident light passes through the smooth layer 2 and the outer base layer 11. Since the refractive indices of the outer base layer 11 and the smooth layer 2 are the same, light loss is reduced. The incident light reaches the surface of the core layer 10, and the reflected light undergoes diffuse reflection through the uneven surface. The transmitted light passes through the core layer 10. Since the refractive index of the core layer 10 is greater than that of the base layer 1, the light transmission is improved, solving the problem that the reflected light causes unclear display content or affects the line of sight, and at the same time ensuring the clarity and wide field of view of the inner room facing the inner base layer 12 for the external graphics.

[0033] In some embodiments, the first surface 101 of the outer substrate 11 is a concave-convex surface, and the second surface 102 of the inner substrate 12 is a concave-convex surface. Observers on both sides of the optical film will not have problems of discomfort or unclear images caused by reflected light, and the applicable scenarios are architectural glass and vehicle windows.

[0034] In some embodiments, the first surface 101 of the outer substrate 11 is a concave-convex surface, and the second surface 102 of the inner substrate 12 is a flat surface. The outer substrate faces the observer, and it is suitable for the application where the optical film is attached to an electronic display screen.

[0035] Furthermore, the depressions and protrusions of the concave-convex surface of the first surface 101 and the concave-convex surface of the second surface 102 correspond one by one and are concave-convexly matched. If the concave-convex surface of the first surface 101 and the concave-convex surface 102 of the second surface are symmetric with respect to the set plane at the midpoint in the film thickness direction, a convex lens will be formed. Although the image will be clear, the sunlight will be concentrated and easily burn the film surface, etc. If the concave-convex surface of the first surface 101 is translated in the film thickness direction to coincide with the concave-convex surface of the second surface 102, that is, the depressions and protrusions of the first surface 101 and the second surface 102 correspond one by one and are concave-convexly matched, so that the transmitted light is emitted parallel.

[0036] The concave-convex surface of the first surface 101 and the concave-convex surface of the second surface 102 can be made by a mold, and then a coating solution containing zirconia or titania material and acrylic polymer monomer is respectively coated on the first surface 101 and the second surface 102, and cured to form a sticky unit core layer. Then, the outer substrate and the inner substrate are compounded through the sticky unit core layer. First, the first surface of the outer substrate is formed into a concave-convex surface by mechanical polishing, laser etching, etc.; then the core layer coating solution is coated on the concave-convex surface of the first surface 101 and cured to form the core layer 10; then the inner substrate 12 is provided on the surface of the core layer 10 away from the first surface 101.

[0037] Among them, the core layer 10 is composed of zirconia or titania material. Zirconia (ZrO2) has a relatively high refractive index (about 2.1 in the visible light range), and is suitable for making optical thin films with high refractive index, such as antireflection films. Zirconia shows good chemical stability in most environments and can resist the erosion of many chemical substances. Zirconia has high thermal stability and can withstand high temperatures without changing its optical properties, and can still maintain its performance in hot summers without precipitation. Zirconia has good transparency, especially in the near-infrared and visible spectral ranges. Titanium dioxide (TiO2) also has a high refractive index (about 2.5 to 2.7 in the visible light range), which makes it an ideal material for making various optical coatings. Titanium dioxide can effectively absorb and scatter ultraviolet rays to protect the substrate, interior objects and observers from ultraviolet damage. Titanium dioxide also has good chemical stability and can resist the erosion of various chemicals.

[0038] The smooth layer 2 includes a smooth outer layer 21 and a bend-resistant inner layer 22. The material of the smooth outer layer 21 is a modified epoxy resin coating, and the material of the bend-resistant inner layer 22 is a polyurethane coating. The modified epoxy resin coating has excellent wear resistance and impact resistance, can effectively protect the base layer from physical damage, and provides a smoother plane, reducing the surface roughness of the base layer. Further, the modifier of the modified epoxy resin coating is polyurethane, which improves the toughness of the epoxy resin and reduces its brittleness. The setting of the polyurethane coating further improves the bend resistance of the optical film, which is suitable for curved glass or display screens.

[0039] The material of the base layer 1 is PET. The PET material has extremely high transparency and a high light transmittance, which enables the optical film made of it to effectively transmit light and reduce visual interference, and is suitable for display devices and optical instruments that require high definition; high-quality PET optical films have a very low birefringence, which means that when light passes through the film, the difference in the speed of light in different polarization directions is small, which is crucial for reducing image distortion and improving display quality; the PET material has good dimensional stability and heat resistance, and can maintain its physical properties within a wide temperature range, ensuring that the optical film can maintain stable optical properties in different usage environments; PET has good resistance to most solvents and chemicals, is not easily affected by moisture or corrosion, which helps to extend the service life of the optical film and maintain its performance.

[0040] A high-temperature resistant adhesive layer 3 is provided on the fourth surface of the inner base layer 12 opposite to the second surface 102 along the layer thickness direction. In order to optimize the optical properties of the adhesive layer, further, the material of the high-temperature resistant adhesive layer 3 is an acrylic pressure-sensitive adhesive layer or an OCA optical adhesive layer.

[0041] The layer thickness of the core layer 10 is 30 - 50 nm, the layer thickness of the smooth layer 2 is 0.2 - 0.6 μm, the layer thickness of the high-temperature resistant adhesive layer 3 is 12 - 15 μm, and the layer thickness of the base layer 1 is 50 - 150 μm.

[0042] An antistatic release film 5 is provided on the surface of the high-temperature resistant adhesive layer 3 away from the base layer 1, and a protective film 4 is provided on the surface of the smooth layer 2 away from the base layer 1.

[0043] Example 1

[0044] As Figure 1As shown in the figure, the low-roughness surface optical film of Embodiment 1 includes a base layer 1, a core layer 10, and a smooth layer 2. The base layer 1 has an outer base layer 11 and an inner base layer 12 that overlap each other. The first surface 101 of the outer base layer 11 is a concave-convex surface. The second surface 102 of the inner base layer 12 is a flat surface. The core layer 10 is sandwiched between the outer base layer 11 and the inner base layer 12 and is in concave-convex fit with the first surface 101 and the second surface 102. The smooth layer 2 is disposed on the third surface (not labeled) of the outer base layer opposite to the first surface 101 along the layer thickness direction. The refractive indices of the base layer 1 and the smooth layer 2 are the same, and the refractive index of the core layer 10 is greater than that of the base layer 1. The smooth layer 2 includes a smooth outer layer 21 and a bend-resistant inner layer 22. The material of the smooth outer layer 21 is a modified epoxy resin coating, and the material of the bend-resistant inner layer 22 is a polyurethane coating. An antistatic release film 5 is disposed on the surface of the high-temperature resistant adhesive layer 3 away from the base layer 1, and a protective film 4 is disposed on the surface of the smooth layer 2 away from the base layer 1.

[0045] Embodiment 2

[0046] As Figure 2 shown in the figure, Embodiment 2 is based on Embodiment 1, and the difference is that the second surface 102 of the inner base layer 12 is a concave-convex surface, and the concave-convex surface of the first surface 101 is translated along the film thickness direction to coincide with the concave-convex surface of the second surface 102, that is, the depressions and protrusions of the first surface 101 and the second surface 102 correspond one by one and are in concave-convex fit.

[0047] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A low-roughness surface optical film, characterized in that: include: A base layer, having an outer base layer and an inner base layer stacked on top of each other; The first surface of the outer base layer is a concave-convex surface; The second surface of the inner base layer is a concave-convex surface or a flat surface; A core layer, sandwiched between the outer base layer and the inner base layer, and matched with the first surface and the second surface in a concave-convex manner; A smoothing layer is provided on a third surface of the outer base layer which is opposite to the first surface along a layer thickness direction; The refractive index of the smooth layer is less than or equal to the refractive index of the base layer, and the refractive index of the core layer is greater than the refractive index of the base layer.

2. The low-roughness surface optical film according to claim 1, characterized in that: The depressions and protrusions of the concave-convex surface of the first surface and the concave-convex surface of the second surface correspond to each other and match each other.

3. The low-roughness optical film according to claim 1, characterized in that: The core layer is made of zirconium dioxide or titanium dioxide material.

4. The low-roughness optical film according to claim 1, characterized in that: The smooth layer comprises a smooth outer layer and a bending-resistant inner layer. The material of the smooth outer layer is a modified epoxy resin coating, and the material of the bending-resistant inner layer is a polyurethane coating.

5. The low-roughness optical film according to claim 1, characterized in that: The material of the base layer is PET.

6. The low-roughness optical film according to claim 1, characterized in that: A high temperature resistant adhesive layer is provided on a fourth surface of the inner base layer which is opposite to the second surface along the layer thickness direction.

7. The low-roughness optical film according to claim 6, characterized in that: The material of the high temperature resistant adhesive layer is an acrylic pressure sensitive adhesive layer or an OCA optical adhesive layer.

8. The low-roughness optical film according to claim 1, characterized in that: The core layer has a thickness of 30-50 nm.

9. The low-roughness optical film according to claim 1, characterized in that: The thickness of the smooth layer is 0.2-0.6 μm.

10. The low-roughness optical film according to claim 6, characterized in that: An antistatic release film is disposed on a surface of the high temperature resistant adhesive layer away from the base layer, and a protective film is disposed on a surface of the smooth layer away from the base layer.

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