High-transmittance base film

Abstract

The utility model discloses a high-light-transmittance base film which comprises anti-sticking surface layers arranged on the two surfaces of a base material core layer respectively. One of the anti-sticking surface layers is an incident surface layer, a first anti-reflection layer and a second anti-reflection layer are arranged on the surface, away from the base material core layer, of the incident surface layer, the second anti-reflection layer is close to the incident surface layer, and the layer thicknesses and the refractive indexes of the first anti-reflection layer, the second anti-reflection layer and the incident surface layer are sequentially increased. The high-transmittance base film is reasonable in structure, the gradient refractive index is formed by stacking the first anti-reflection layer, the second anti-reflection layer and the incident surface layer and adjusting the thickness, and then the light transmittance of incident light is improved; and by arranging the first anti-reflection layer and the second anti-reflection layer, the wear resistance and the smoothness of the base film can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of film structures, in particular to a high-light-transmittance base film. Background Art

[0002] Polyester film has higher requirements for optical application performance. In addition to good basic properties such as mechanical strength and thermal stability, it also has excellent optical properties such as low haze, high light transmittance and high cleanliness. It can be made into functional optical films and is widely used in liquid crystal display panels, flexible display screens, control panels and window films. As a base film in the optical field, polyester film often needs to be added with a certain amount of additives and auxiliary materials to meet the requirements of excellent optical properties and film processing performance, adjust the surface structure of the film, improve the physical properties of the film (such as surface friction coefficient, flame retardancy and mechanical properties) and facilitate the post-processing of the film (anti-adhesion). However, their addition will affect the optical properties of the polyester film.

[0003] Therefore, it is necessary to improve the base film in the prior art. Utility Model Content

[0004] The purpose of the utility model is to overcome the defects existing in the prior art and provide a high-transmittance base film, which forms a gradient refractive index by stacking the first anti-transmittance layer and the second anti-transmittance layer with the incident surface layer and adjusting the thickness, thereby improving the transmittance of the incident light; the wear resistance and flatness of the base film can also be improved by setting the first anti-transmittance layer and the second anti-transmittance layer.

[0005] In order to achieve the above technical effects, the technical solution of the utility model is: a high light transmittance base film, comprising:

[0006] The anti-sticking surface layer is disposed on two surfaces of the substrate core layer;

[0007] One of the anti-sticking surface layers is an incident surface layer, and the surface of the incident surface layer away from the substrate core layer is provided with a first anti-reflection layer and a second anti-reflection layer, and the second anti-reflection layer is close to the incident surface layer, and the layer thickness and refractive index of the first anti-reflection layer, the second anti-reflection layer and the incident surface layer increase in sequence.

[0008] A preferred technical solution is that the other of the anti-sticking surface layer is an exit surface layer, and a third anti-reflection layer is arranged on the surface of the exit surface layer away from the substrate core layer, the thickness of the third anti-reflection layer and the exit surface layer increases successively, and the refractive index of the exit surface layer and the third anti-reflection layer increases successively.

[0009] A preferred technical solution is that the refractive particles contained in the first anti-reflection layer, the second anti-reflection layer and the incident surface layer are all silicon dioxide.

[0010] A preferred technical solution is that the refractive particles contained in the emission surface layer are silicon dioxide, and the refractive particles contained in the third anti-reflection layer are zirconium dioxide.

[0011] A preferred technical solution is that the refractive indexes of the incident surface layer, the substrate core layer and the exit surface layer increase in sequence, or the refractive index of the substrate core layer is consistent with the refractive index of one of the incident surface layer and the exit surface layer.

[0012] A preferred technical solution is that the main material of the first anti-reflection layer, the second anti-reflection layer and the third anti-reflection layer is polyurethane-modified acrylic resin.

[0013] A preferred technical solution is that the material of the incident surface layer, the substrate core layer and the exit surface layer is polyethylene terephthalate.

[0014] The preferred technical solution is that the layer thickness ratio of the incident surface layer, the substrate core layer and the exit surface layer is 1: (8-16): 1, and the total film thickness of the base film is 25-125 μm.

[0015] A preferred technical solution is that the first anti-reflection layer has a thickness of 80-105 μm, the second anti-reflection layer has a thickness of 0.5-1.5 μm, and the third anti-reflection layer has a thickness of 100-150 μm.

[0016] The advantages and beneficial effects of the utility model are:

[0017] The high-transmittance base film has a reasonable structure. By stacking the first anti-transmittance layer and the second anti-transmittance layer with the incident surface layer, the gradient refractive index and thickness are adjusted by selecting and combining the refractive indices of the raw materials, thereby improving the transmittance of the incident light; the wear resistance and flatness of the base film can also be improved by setting the first anti-transmittance layer and the second anti-transmittance layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the structure of Example 1 of the high light transmittance base film of the utility model;

[0019] Figure 2 It is a schematic structural diagram of Example 2 of the high light transmittance base film of the utility model.

[0020] In the figure: 1, substrate core layer; 11, incident surface layer; 12, exit surface layer; 21, first anti-reflection layer; 22, second anti-reflection layer; 23, third anti-reflection layer. DETAILED DESCRIPTION

[0021] The following is a further description of the specific implementation of the present invention in conjunction with the accompanying drawings and embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0022] The “surface layer” is based on the high-transmittance base film in normal use state, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0023] In addition, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the invention of the utility model, unless otherwise specified, the meaning of "plurality" is two or more.

[0024] like Figure 1~2 As shown, a high light transmittance base film disclosed in the utility model comprises a non-stick surface layer and a substrate core layer 1 , wherein the non-stick surface layer is disposed on two surfaces of the substrate core layer 1 .

[0025] One of the anti-adhesive surface layers is the incident surface layer 11, and the other is the exit surface layer 12. The incident surface layer 11, the substrate core layer 1 and the exit surface layer 12 are made of polyethylene terephthalate. PET material has extremely high transparency and 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 film has a very low birefringence, which means that when light passes through the film, the speed of light in different polarization directions is small, which is crucial to reducing image distortion and improving display quality; PET material has good dimensional stability and heat resistance, and can maintain its physical properties in a wide temperature range, ensuring that the optical film can maintain stable optical properties under different use environments; PET has good resistance to most solvents and chemicals, and is not easily affected by moisture or corrosion, which helps to extend the service life of the optical film and maintain its performance; PET material has a low density and high mechanical strength and rigidity, which makes the PET-based optical film both thin and durable, suitable for applications requiring lightweight and high reliability.

[0026] The first anti-reflection layer 21 and the second anti-reflection layer 22 are arranged on the surface of the incident surface layer 11 away from the substrate core layer 1, and the second anti-reflection layer 22 is close to the incident surface layer 11. The thickness and refractive index of the first anti-reflection layer 21, the second anti-reflection layer 22 and the incident surface layer 11 are increased in sequence. The refractive particles contained in the first anti-reflection layer 21, the second anti-reflection layer 22 and the incident surface layer 11 are all silicon dioxide, and the refractive particles contained in the exit surface layer 12 are also silicon dioxide. The refractive indices of the incident surface layer 11, the substrate core layer 1 and the exit surface layer 12 are increased in sequence.

[0027] The first anti-reflection layer 21: a coating liquid made of polyurethane-modified acrylic resin containing 2% to 4% of silicon dioxide particles with a particle size of 100 to 150 nm, dried and cured in a circulating oven at 60°C, 75°C, 85°C, 90°C, and 80°C, with a refractive index of 1.30 to 1.35.

[0028] Second anti-reflection layer 22: Polyurethane-modified acrylic resin is configured into a coating liquid, containing 0.5% to 1.5% of silicon dioxide particles with a particle size of 50 to 80 nm, and is dried and cured in a circulating oven at 60°C, 75°C, 85°C, 90°C, and 80°C, with a refractive index of 1.35 to 1.40.

[0029] Incident surface layer 11: 0.1%~0.5% silica particles with a particle size of 10~100nm blended with PET, with a refractive index of 1.40~1.43.

[0030] The exit surface layer 12 is composed of 0.05% to 0.1% silicon dioxide particles with a particle size of 0.1 to 1 μm and PET, and the refractive index is 1.43 to 1.46.

[0031] The substrate core layer 1 is 100% polyethylene terephthalate, and the refractive index of polyethylene terephthalate is controlled at 1.42-1.44, which is consistent with the refractive index of the incident surface layer 11 and the exit surface layer 12, or the incident surface layer 11, the substrate core layer 1 and the exit surface layer 12 increase in sequence.

[0032] First, the anti-sticking surface layer and the substrate core layer 1 disposed on both surfaces of the substrate core layer 1 are co-extruded films, which can be three-layer, five-layer and seven-layer co-extruded films, and are produced according to the specific settings of the equipment. The anti-sticking surface layer adjusts the haze and optical properties by adding silicon dioxide with different particle sizes and contents to the surface of the co-extruded film. According to actual needs, the first anti-reflection layer 21, the second anti-reflection layer 22 and the third anti-reflection layer 23 are coated on the surface of the anti-sticking surface layer to form a gradient refractive index to reduce Fresnel reflection loss.

[0033] In another embodiment, a third anti-reflection layer 23 is provided on the surface of the exit surface layer 12 away from the substrate core layer 1, and the thickness of the third anti-reflection layer 23 and the exit surface layer 12 increases successively, and the refractive index of the exit surface layer 12 and the third anti-reflection layer 23 increases successively. The refractive particles contained in the third anti-reflection layer 23 are zirconium dioxide. The third anti-reflection layer 23: polyurethane modified acrylic resin is configured into a coating liquid, containing 2% to 4% zirconium dioxide particles with a particle size of 3 to 12 nm, and is dried and cured in a circulating oven at 70°C, 95°C, 110°C, 120°C, 130°C, and 95°C, and the refractive index is greater than 1.8.

[0034] The main material of the first anti-reflection layer 21, the second anti-reflection layer 22 and the third anti-reflection layer 23 is polyurethane modified acrylic resin. After polyurethane modification, the hardness and scratch resistance of acrylic resin are improved, that is, wear resistance, while maintaining good flexibility. This balance makes the modified resin both durable and not easy to break; polyurethane modified acrylic resin can form a continuous and uniform coating at a lower temperature, reducing the requirements for construction conditions and shortening the drying time; acrylic resin has good weather resistance, and after modification, it further enhances the resistance to environmental factors such as ultraviolet rays, moisture, acid and alkali, and prolongs the service life of the coating; the introduction of polyurethane enhances the adhesion between the resin and the substrate, is suitable for surface treatment of various materials, and improves the overall stability of the coating; the modified resin can be prepared into a solvent-free environmentally friendly product, reducing the harm to the environment and human health, and meeting the requirements of modern green production; the tensile strength and compressive strength of the modified resin are significantly improved.

[0035] The thickness ratio of the anti-sticking surface layer and the substrate core layer is optimized to improve the optical and mechanical properties of the co-extruded film. The layer thickness ratio of the incident surface layer 11, the substrate core layer 1 and the exit surface layer 12 is 1: (8-16): 1, and the total film thickness of the base film is 25-125 μm.

[0036] The first anti-reflection layer 21 has a thickness of 80 to 105 μm, the second anti-reflection layer 22 has a thickness of 0.5 to 1.5 μm, and the third anti-reflection layer 23 has a thickness of 100 to 150 μm.

[0037] Example 1

[0038] like Figure 1 As shown, the high light transmittance base film of Example 1 includes a release surface layer and a substrate core layer, wherein the release surface layer is disposed on two surfaces of the substrate core layer, one of the release surface layers is an incident surface layer 11, and the other is an exit surface layer 12. The surface of the incident surface layer 11 away from the substrate core layer 1 is provided with a first anti-reflection layer 21 and a second anti-reflection layer 22, and the second anti-reflection layer 22 is close to the incident surface layer 11.

[0039] Example 2

[0040] like Figure 2 As shown, Example 2 is based on Example 1, except that a third anti-reflection layer 23 is provided on the surface of the exit surface layer 12 away from the substrate core layer 1. Example 2 has a higher light transmittance than Example 1, but Example 1 is more economical than Example 2.

[0041] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A highly light-transmittance base film, comprising: The anti-sticking surface layer is disposed on two surfaces of the substrate core layer; It is characterized in that one of the anti-sticking surface layers is an incident surface layer, and the surface of the incident surface layer away from the core layer of the substrate is provided with a first anti-reflection layer and a second anti-reflection layer, and the second anti-reflection layer is close to the incident surface layer, and the layer thickness and refractive index of the first anti-reflection layer, the second anti-reflection layer and the incident surface layer increase successively.

2. The high light transmittance base film according to claim 1, characterized in that: The other of the anti-sticking surface layer is an exit surface layer, and a third anti-reflection layer is arranged on the surface of the exit surface layer away from the substrate core layer. The thickness of the third anti-reflection layer and the exit surface layer increases successively, and the refractive index of the exit surface layer and the third anti-reflection layer increases successively.

3. The high light transmittance base film according to claim 1 or 2, characterized in that: The refractive particles contained in the first anti-reflection layer, the second anti-reflection layer and the incident surface layer are all silicon dioxide.

4. The high light transmittance base film according to claim 2, characterized in that: The refractive particles contained in the emission surface layer are silicon dioxide, and the refractive particles contained in the third anti-reflection layer are zirconium dioxide.

5. The high light transmittance base film according to claim 2, characterized in that: The refractive indexes of the incident surface layer, the substrate core layer and the exit surface layer increase in sequence, or the refractive index of the substrate core layer is consistent with the refractive index of one of the incident surface layer and the exit surface layer.

6. The high light transmittance base film according to claim 2, characterized in that: The main material of the first anti-reflection layer, the second anti-reflection layer and the third anti-reflection layer is polyurethane-modified acrylic resin.

7. The high light transmittance base film according to claim 2 or 5, characterized in that: The incident surface layer, the substrate core layer and the exit surface layer are made of polyethylene terephthalate.

8. The high light transmittance base film according to claim 2 or 5, characterized in that: The layer thickness ratio of the incident surface layer, the substrate core layer and the exit surface layer is 1:(8-16):1, and the total film thickness of the base film is 25-125 μm.

9. The high light transmittance base film according to claim 2, characterized in that: The first anti-reflection layer has a thickness of 80-105 μm, the second anti-reflection layer has a thickness of 0.5-1.5 μm, and the third anti-reflection layer has a thickness of 100-150 μm.

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