Single-layer PET reflective film and backlight module

Abstract

The present invention discloses a single-layer PET reflective film and a backlight module. The reflective film comprises a PET substrate, and the two end surfaces of the PET substrate are defined as a light incident side and a backlight side; a primer layer coated on the light incident side of the PET substrate; a metal reflective layer vacuum-plated on the primer layer; and a protective layer, comprising a first protective coating layer arranged on the metal reflective layer and a second protective coating layer arranged on the first protective coating layer, wherein the refractive index of the first protective coating layer is greater than the refractive index of the second protective coating layer; wherein the thickness of the PET substrate is 50 to 300 μm, the thickness of the primer layer is 0.5 to 1.5 μm, the thickness of the metal reflective layer is 160 to 320 nm, the thickness of the first protective coating layer is 3 to 8 μm, and the refractive index n thereof is 1.50 to 1.55, and the thickness of the second protective coating layer is 2 to 5 μm, and the refractive index n thereof is 1.47 to 1.50.

Description

Technical Field

[0001] The present invention relates to the technical field of optical films, and in particular to a single-layer PET reflective film and a backlight module. Background Art

[0002] The reflector reflects the unscattered light source back into the light conduction area. The reflection method of the reflector is mirror reflection, which improves the utilization rate of light.

[0003] Reference Figure 1 There is an optical reflector currently on the market, and this reflector is formed by sputtering a metallic silver reflective material on a base coating of a PET substrate and then coating it with a protective coating. However, the shortcomings of this reflector are: first, due to the inadequate protection of the protective coating, the metallic silver coating will be affected by the ambient temperature and humidity and produce oxidation discoloration, thereby affecting the reflection efficiency of the reflector; second, the quality of this reflector is affected by the thickness of the metallic silver reflective material. When the thickness of the metallic silver reflective layer is not enough, the metallic silver cannot form an effective reflection on the PET substrate, so that the incident light penetrates through the silver layer and is emitted from the side of the reflector away from the incident light, thereby reducing the utilization rate of light. When the thickness of the metallic silver reflective layer is thicker, the production cost of the reflector increases due to the high price of metallic silver.

[0004] Attached Figure 2 This is a reflective sheet structure (named GF-80D2) that is currently being mass-produced by the creator of this exercise. The reflective sheet includes a PET bottom mold, an aluminum film is coated on the bottom mold, a glue layer is set on the aluminum film (the glue layer thickness is set to 3 to 5μm), a silver film is set on the glue layer, and finally a PET top mold layer is set on the silver layer. When light enters from the PET top mold layer of the reflective sheet, reflection occurs when passing through the PET top film layer, the light input is reduced, and the light loss is serious. In practice, the PET bottom mold coated with aluminum film is laminated with the PET top film coated with silver film. When the silver film and the aluminum film are laminated, there is also a problem of warping due to the different shrinkage rates of the metal films. The warping problem increases as the thickness of the PET film decreases.

[0005] In order to solve the above problems, a non-glue continuous metal plating design (vacuum plating) is currently used to form an effective shielding, and the design reduces the bonding process and can reduce the thickness of the silver layer.

[0006] However, the main problem with the optical reflector using a non-adhesive continuous metal coating design is how to protect the reflective silver layer, that is, how to effectively prevent the silver reflective layer from being oxidized.

[0007] Therefore, the creator of this exercise combined his own production and processing needs to design a single-layer PET reflective film that uses an organic coating to protect the metal reflective layer and does not hinder the entry and exit of light. Summary of the invention

[0008] The technical problem solved by the present invention is to provide a single-layer PET reflective film which uses an organic coating to protect a metal reflective layer and does not hinder light entry and light exit in view of the defects existing in the above-mentioned prior art.

[0009] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows: a single-layer PET reflective film, comprising:

[0010] A PET substrate, the two end surfaces of the PET substrate are defined as a light incident side and a backlight side; a primer layer, coated on the light incident side of the PET substrate; a metal reflective layer, vacuum-plated on the primer layer; a protective layer, including a first protective coating layer arranged on the metal reflective layer and a second protective coating layer arranged on the first protective coating layer, the refractive index of the first protective coating layer is greater than the refractive index of the second protective coating layer; wherein the thickness of the PET substrate is 50 to 300 μm, the thickness of the primer layer is 0.5 to 1.5 μm, the thickness of the metal reflective layer is 120 to 320 nm, the thickness of the first protective coating layer is 3 to 8 μm, the refractive index n thereof is 1.50-1.55, the thickness of the second protective coating layer is 2 to 5 μm, and the refractive index n thereof is 1.47 to 1.53.

[0011] As a further elaboration of the above technical solution,

[0012] In the above technical solution, the first protective coating is a hardened coating of one of cyclic olefin copolymer TOPAS 9506F-04, cyclic olefin copolymer TOPAS 8007F-04, cyclic olefin copolymer TOPAS 8007F-400, cyclic olefin copolymer TOPAS 6013F-04 and cyclic olefin copolymer TOPAS 8007F-600.

[0013] In the above technical scheme, the second protective coating is a UV-7600B hard optical film with a viscosity of 2000-4000mPa·s / 25°C, a molecular weight of 1400MW, a pencil hardness of 3H, and a curing shrinkage rate of 6.3%, or a UV-7640B hard optical film with a viscosity of 2000-5000mPa·s / 25°C, a molecular weight of 1500MW, a pencil hardness of 3H-4H, and a curing shrinkage rate of 6.6%, or a UV-7630B plastic hard coating with a viscosity of 3000-7000mPa·s / 25°C, a molecular weight of 2200MW, a pencil hardness of 3H, and a curing shrinkage rate of 6.4%.

[0014] In the above technical solution, the primer layer is a hardened coating of one of cyclic olefin copolymer TOPAS 9506F-04, cyclic olefin copolymer TOPAS 8007F-04, cyclic olefin copolymer TOPAS 8007F-400, cyclic olefin copolymer TOPAS 6013F-04 and cyclic olefin copolymer TOPAS 8007F-600.

[0015] In the above technical solution, the metal reflective layer includes a thickness compensation layer evaporated or sputtered on the base coating layer and a silver reflective layer evaporated or sputtered on the thickness compensation layer, wherein the thickness of the thickness compensation layer is 60 to 200 nm, and the thickness of the silver reflective layer is 60 to 120 nm.

[0016] In the above technical solution, the thickness compensation layer is an aluminum metal layer evaporated or sputtered on the base coating, or a titanium metal layer evaporated or sputtered on the base coating, or an aluminum-titanium alloy layer sputtered on the base coating.

[0017] In the above technical solution, the thickness of the PET substrate is 75 μm, the thickness of the base coating is 1 μm, the thickness of the thickness compensation layer is 150 nm, the thickness of the silver reflective layer is 80 nm, the thickness of the first protective coating is 5 μm, and its refractive index n is 1.53, and the thickness of the second protective coating is 3 μm, and its refractive index n is 1.5.

[0018] In the above technical solution, the metal reflective layer is a pure silver reflective layer.

[0019] In the above technical solution, the thickness of the PET substrate is 75 μm, the thickness of the base coating is 1 μm, the thickness of the pure silver reflective layer is 150 nm, the thickness of the first protective coating is 5 μm, and its refractive index n is 1.53, and the thickness of the second protective coating is 3 μm, and its refractive index n is 1.5.

[0020] To solve the above technical problems, another technical solution adopted by the present invention is as follows: a backlight module comprises a back panel, a light source, a light guide plate and a reflective film arranged in sequence, wherein the reflective film is the above-mentioned single-layer PET reflective film.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: the reflective film of the present invention is provided with a primer layer on the PET substrate and a metal reflective layer on the primer layer, and the metal reflective layer compensates for light leakage; and a first protective layer (high refractive index layer) and a second protective layer (low refractive index layer) are provided on the reflective layer, and the refractive indices of the first protective layer and the second protective layer are close, so that the visible penetration (light input) is improved while protecting the metal reflective layer from oxidation, and the reflected penetration (light output) is not prevented. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural view of an existing PET reflective sheet;

[0023] Figure 2 It is a schematic diagram of the structure of a conventional reflector;

[0024] Figure 3 is a schematic structural diagram of an embodiment of the present invention;

[0025] Figure 4 This is another structural view of an embodiment of the present invention. DETAILED DESCRIPTION

[0026] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0027] The embodiments described with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and cannot be understood as limiting the present application. In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate the orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present application, "several" and "multiple" mean two or more, unless otherwise clearly and specifically defined. In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a communication between the two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances. In this application, unless otherwise clearly specified and limited, the first feature "above" or "below" the second feature can include the first and second features being in direct contact, or it can include the first and second features not being in direct contact but being in contact through another feature between them. Moreover, the first feature "above", "above" and "above" the second feature include the first feature being directly above and obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature "below", "below" and "below" the second feature include the first feature being directly above and obliquely above the second feature, or simply means that the first feature is lower in level than the second feature.

[0028] Example 1

[0029] Reference Figure 3 , a single-layer PET reflective film, comprising:

[0030] A PET substrate 100, where two end surfaces of the PET substrate 100 are defined as a light incident side 001 and a backlight side 002; in practice, the PET substrate can be selected from transparent, white, black, or gray PET;

[0031] A primer layer 200 is coated on the light incident side of the PET substrate 100. In practice, the primer layer 200 needs to have good ductility. When a cutting machine is used to cut the entire reflective sheet into a single reflective sheet, the primer layer 200 will cover the side of the reflective layer 300 provided on the primer layer 200, thereby preventing the main reflective layer of the reflective layer 300 from being oxidized. At the same time, the primer layer 200 also has the function of blocking air and water for the PET substrate 100. In this embodiment, the primer layer 200 is a hardened coating of one of olefin copolymer TOPAS 9506F-04, cyclic olefin copolymer TOPAS 8007F-04, cyclic olefin copolymer TOPAS 8007F-400, cyclic olefin copolymer TOPAS 6013F-04 and cyclic olefin copolymer TOPAS 8007F-600.

[0032] A metal reflective layer 300 is vacuum-plated on the base coating layer 200. In this embodiment, the metal reflective layer 300 is a pure silver reflective layer;

[0033] A protective layer 400, comprising a first protective coating 401 disposed on the metal reflective layer 300 and a second protective coating 402 disposed on the first protective coating 401, wherein the refractive index of the first protective coating 401 is greater than the refractive index of the second protective coating 402;

[0034] Among them, the thickness of the PET substrate 100 is 50 to 300 μm, preferably 75 μm, the thickness of the primer layer 200 is 0.5 to 1.5 μm, preferably 1.0 μm, the thickness of the metal reflective layer 300 is 120 to 320 nm, preferably 230 nm, the thickness of the first protective coating 401 is 3 to 8 μm, preferably 5 μm, and its refractive index n is 1.50-1.55, preferably the refractive index n is 1.53, the thickness of the second protective coating 402 is 2 to 5 μm, preferably 3 μm, and its refractive index n is 1.47 to 1.50, preferably the refractive index n is 1.5.

[0035] It should be noted that the first protective coating 401 and the second protective coating 402 in this embodiment are combined into an anti-reflection layer, which helps to improve visible penetration and does not prevent reflection penetration. In this embodiment, the difference between the high and low refractive indexes of the first protective layer 401 and the second protective layer 402 is reduced, that is, the refractive indexes of the reflection penetration of the first protective layer 401 and the second protective layer 402 are balanced, so as to achieve the oxidation and hardening of the first protective layer 401 and the second protective layer 402 to protect the metal reflection layer 300. In this embodiment, the first protective layer 401 and the second protective layer 402 are not emphasized. The reflection or increase of the light of the reflective sheet is also utilized, but the double-layer film anti-reflection principle of the first protective layer 401 and the second protective layer 402 is also utilized, and the incident light anti-reflection is generated by the difference in the high and low refractive indexes of the two protective layers; for the refractive index of the first protective coating 401 and the second protective coating 402, when the refractive index of the second protective coating 402 changes with the refractive index of the first protective coating 401, that is, when the first protective coating 401 with a small refractive index is selected, the refractive index of the second protective coating 402 is also selected to be relatively small. In practice, the refractive index difference between the first protective coating 401 and the second protective coating 402 is selected to be 0.2-0.3.

[0036] It can be understood that in this embodiment, the first protective coating 401 is a hardened coating of one of cyclic olefin copolymer TOPAS 9506F-04, cyclic olefin copolymer TOPAS 8007F-04, cyclic olefin copolymer TOPAS 8007F-400, cyclic olefin copolymer TOPAS6013F-04 and cyclic olefin copolymer TOPAS 8007F-600. The so-called cyclic olefin copolymer is a COC material. In this embodiment, it is coated on the metal silver reflective layer 300 to form a protective film. In this embodiment, the water vapor permeability (38°C, 90%RH) of the first protective layer 401 after hardening is 0.85g·100μm / (m 2 ·day).

[0037] It can be understood that in this embodiment, in order to achieve the high hardness and low shrinkage performance of the second protective layer 402, the second protective layer 402 can select a UV-7600B hard optical film with a viscosity of 2000-4000mPa·s / 25°C, a molecular weight of 1400MW, a pencil hardness of 3H, and a curing shrinkage of 6.3%, a UV-7640B hard optical film with a viscosity of 2000-5000mPa·s / 25°C, a molecular weight of 1500MW, a pencil hardness of 3H-4H, and a curing shrinkage of 6.6%, and a UV-7630B plastic hard coating with a viscosity of 3000-7000mPa·s / 25°C, a molecular weight of 2200MW, a pencil hardness of 3H, and a curing shrinkage of 6.4%; the above-mentioned hard optical films and plastic hard coatings are products of the Mitsubishi SHIKOH hard film series. In practice, other hard films that meet the requirements of high hardness and low shrinkage can also be used.

[0038] Example 2

[0039] Reference Figure 4 , a single-layer PET reflective film, comprising:

[0040] A PET substrate 100, where two end surfaces of the PET substrate 100 are defined as a light incident side 001 and a backlight side 002; in practice, the PET substrate can be selected from transparent, white, black, or gray PET;

[0041] A primer layer 200 is coated on the light incident side of the PET substrate 100. In practice, the primer layer 200 needs to have good ductility. When a cutting machine is used to cut the entire reflective sheet into a single reflective sheet, the primer layer 200 will cover the side of the reflective layer 300 provided on the primer layer 200, thereby preventing the main reflective layer of the reflective layer 300 from being oxidized. At the same time, the primer layer 200 also has the function of blocking air and water for the PET substrate 100. In this embodiment, the primer layer 200 is a hardened coating of one of olefin copolymer TOPAS 9506F-04, cyclic olefin copolymer TOPAS 8007F-04, cyclic olefin copolymer TOPAS 8007F-400, cyclic olefin copolymer TOPAS 6013F-04 and cyclic olefin copolymer TOPAS 8007F-600.

[0042] A metal reflective layer 300 is vacuum-deposited on the base coating layer 200 , wherein the metal reflective layer 300 includes a thickness compensation layer 301 evaporated or sputtered on the base coating layer 200 and a silver reflective layer 302 evaporated or sputtered on the thickness compensation layer 301;

[0043] A protective layer 400, comprising a first protective coating 401 disposed on the metal reflective layer 300 and a second protective coating 402 disposed on the first protective coating 401, wherein the refractive index of the first protective coating 401 is greater than the refractive index of the second protective coating 402;

[0044] Among them, the thickness of the PET substrate 100 is 50-300 μm, preferably 75 μm, the thickness of the primer layer 200 is 0.5-1.5 μm, preferably 1.0 μm, the thickness of the thickness compensation layer 301 is 60-200 nm, preferably 150 nm, the thickness of the silver reflective layer 302 is 60-120 nm, preferably 80 nm, the thickness of the first protective coating 401 is 3-8 μm, preferably 5 μm, and its refractive index n is 1.50-1.55, preferably the refractive index n is 1.53, the thickness of the second protective coating 402 is 2-5 μm, preferably 3 μm, and its refractive index n is 1.47-1.50, preferably the refractive index n is 1.5.

[0045] It should be noted that the first protective coating 401 and the second protective coating 402 in this embodiment are combined into an anti-reflection layer, which helps to improve visible penetration and does not prevent reflection penetration. In this embodiment, the difference between the high and low refractive indexes of the first protective layer 401 and the second protective layer 402 is reduced, that is, the refractive indexes of the reflection penetration of the first protective layer 401 and the second protective layer 402 are balanced, so as to achieve the oxidation and hardening of the first protective layer 401 and the second protective layer 402 to protect the metal reflection layer 300. In this embodiment, the first protective layer 401 and the second protective layer 402 are not emphasized. The reflection or increase of the light of the reflective sheet is also utilized, but the double-layer film anti-reflection principle of the first protective layer 401 and the second protective layer 402 is also utilized, and the incident light anti-reflection is generated by the difference in the high and low refractive indexes of the two protective layers; for the refractive index of the first protective coating 401 and the second protective coating 402, when the refractive index of the second protective coating 402 changes with the refractive index of the first protective coating 401, that is, when the first protective coating 401 with a small refractive index is selected, the refractive index of the second protective coating 402 is also selected to be relatively small. In practice, the refractive index difference between the first protective coating 401 and the second protective coating 402 is selected to be 0.2-0.3.

[0046] It can be understood that in this embodiment, the first protective coating 401 is a hardened coating of one of cyclic olefin copolymer TOPAS 9506F-04, cyclic olefin copolymer TOPAS 8007F-04, cyclic olefin copolymer TOPAS 8007F-400, cyclic olefin copolymer TOPAS6013F-04 and cyclic olefin copolymer TOPAS 8007F-600. The so-called cyclic olefin copolymer is a COC material. In this embodiment, the above cyclic olefin copolymer is coated on the metal silver reflective layer 300 to form a protective film. In this embodiment, the water vapor permeability (38°C, 90%RH) of the first protective layer 401 after hardening is 0.85g·100μm / (m 2 ·day).

[0047] It can be understood that in this embodiment, in order to achieve the high hardness and low shrinkage performance of the second protective layer 402, the second protective layer 402 can select a UV-7600B hard optical film with a viscosity of 2000-4000mPa·s / 25°C, a molecular weight of 1400MW, a pencil hardness of 3H, and a curing shrinkage of 6.3%, a UV-7640B hard optical film with a viscosity of 2000-5000mPa·s / 25°C, a molecular weight of 1500MW, a pencil hardness of 3H-4H, and a curing shrinkage of 6.6%, and a UV-7630B plastic hard coating with a viscosity of 3000-7000mPa·s / 25°C, a molecular weight of 2200MW, a pencil hardness of 3H, and a curing shrinkage of 6.4%; the above-mentioned hard optical films and plastic hard coatings are products of the Mitsubishi SHIKOH hard film series. In practice, other hard films that meet the requirements of high hardness and low shrinkage can also be used.

[0048] It can be understood that in this embodiment, due to the lower activity of silver than other metals or alloys, silver will not be more active than other metals at the anode position, oxidation can be suppressed, and the thickness of the silver layer and light leakage can be compensated at the same time. The thickness compensation layer 301 is an aluminum metal layer evaporated or sputtered on the base coating 200, or a titanium metal layer evaporated or sputtered on the base coating 200, or an aluminum-titanium alloy layer sputtered on the base coating 200.

[0049] In practice, the reflective sheets with different thicknesses of PET substrate, thickness compensation layer, silver reflective layer and protective layer in this embodiment are selected on the glass substrate and irradiated with light of 550nm wavelength, and the reflectivity and brightness are measured and compared with the reflective sheets of model GF-80D2 mass-produced by the applicant of this application as follows (in the table, coc represents the first protective layer, and uv represents the second protective layer):

[0050]

[0051] The reflective sheets of the above thicknesses were subjected to high temperature storage test and hot and cold shock oxidation test as follows: (Test A)

[0052]

[0053]

[0054] 120h resistance to various temperature and humidity conditions: "0" represents "no oxidation", "1" represents "slight oxidation", and "2" represents "severe oxidation";

[0055] The test conditions are in accordance with the industry standard for optical films of LCD backlight modules, and refer to GB / T1740-2007 or ISO4611:2010.

[0056] The test process of 60℃95%RH high temperature and high humidity test is as follows: high temperature and high humidity test is carried out in a high temperature furnace at 60℃ and relative humidity 95%RH for 120 hours continuously; 80℃ high temperature storage test is carried out in a high temperature furnace for 120 hours;

[0057] Thermal shock test oxidation reference IEC 60068-2-14:2009Na or GB / T 2423.22-2012Na, the reflector is operated between -40℃ and 80℃, with an interval of 30min, for 100 consecutive tests.

[0058] Among them, GF-80D2 is an existing product of Guangzhi Optoelectronics, with a structure of PET silver-coated film (25μm) with 3-5μm polyurethane bonded to 50μm PET aluminum-coated film. The pencil hardness test refers to GB 6739-86 "Coating Hardness Pencil Hardness Method".

[0059] The PET emissive films of the above thicknesses were subjected to a high temperature storage test (Test B):

[0060]

[0061]

[0062] 240h ​​resistance to various temperature and humidity conditions: "0" represents "no oxidation", "1" represents "slight oxidation", and "2" represents "severe oxidation";

[0063] The test conditions are in accordance with the industry standard for optical films of LCD backlight modules, and refer to GB / T1740-2007 or ISO4611:2010.

[0064] The test process of 60℃95%RH high temperature and high humidity test is as follows: high temperature and high humidity test is carried out in a high temperature furnace at 60℃ and relative humidity 95%RH for 240 hours continuously; 80℃ high temperature storage test is carried out in a high temperature furnace for 240 hours;

[0065] Among them, GF-80D2 is an existing product of Guangzhi Optoelectronics, with a structure of PET silver-coated film (25μm) with 3-5μm polyurethane bonded to 50μm PET aluminum-coated film. The pencil hardness test refers to GB 6739-86 "Coating Hardness Pencil Hardness Method".

[0066] Test C:

[0067]

[0068]

[0069] 500h resistance to various temperature and humidity conditions: "0" represents "no oxidation", "1" represents "slight oxidation", and "2" represents "severe oxidation";

[0070] The test conditions are in accordance with the industry standard for optical films of LCD backlight modules, and refer to GB / T1740-2007 or ISO4611:2010.

[0071] The test process of 60℃95%RH high temperature and high humidity test is as follows: high temperature and high humidity test is carried out in a high temperature furnace, and the test is carried out continuously for 500 hours at 60℃ and relative humidity 95%RH; 80℃ high temperature storage test is carried out in a high temperature furnace for 500 hours;

[0072] Among them, GF-80D2 is an existing product of Guangzhi Optoelectronics, with a structure of PET silver-coated film (25μm) with 3-5μm polyurethane bonded to 50μm PET aluminum-coated film. The pencil hardness test refers to GB 6739-86 "Coating Hardness Pencil Hardness Method".

[0073] Based on the above embodiments and test results, it can be known that the single-layer reflective sheet of the present invention is provided with a primer layer on the PET substrate and a metal reflective layer on the primer layer, and the metal reflective layer compensates for light leakage; and a first protective layer (high refractive index layer) and a second protective layer (low refractive index layer) are provided on the reflective layer, and the refractive indices of the first protective layer and the second protective layer are close, so that the metal reflective layer is protected from oxidation, and visible penetration (light input) is improved, and reflected penetration (light output) is not prevented.

[0074] The present invention also provides an embodiment, a backlight module, comprising a back panel (not shown in the drawings), a light source (not shown in the drawings), a light guide plate (not shown in the drawings) and a reflective film arranged in sequence, wherein the reflective film is a single-layer PET reflective film described in Example 1 or Example 2.

[0075] The above does not limit the technical scope of the present invention in any way. Any modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A single-layer PET reflective film, characterized in that: include: A PET substrate, wherein two end surfaces of the PET substrate are defined as a light incident side and a backlight side; A primer layer, coated on the light incident side of the PET substrate; A metal reflective layer is vacuum-plated on the base coating; A protective layer, comprising a first protective coating layer disposed on the metal reflective layer and a second protective coating layer disposed on the first protective coating layer, wherein the refractive index of the first protective coating layer is greater than the refractive index of the second protective coating layer; wherein, The thickness of the PET substrate is 50-300 μm, the thickness of the primer layer is 0.5-1.5 μm, the thickness of the metal reflective layer is 160-320 nm, the thickness of the first protective coating is 3-8 μm, and its refractive index n is 1.50-1.55, and the thickness of the second protective coating is 2-5 μm, and its refractive index n is 1.47-1.

50.

2. A single-layer PET reflective film according to claim 1, characterized in that: The first protective coating is a hardened coating of one of cyclic olefin copolymer TOPAS 9506F-04, cyclic olefin copolymer TOPAS 8007F-04, cyclic olefin copolymer TOPAS 8007F-400, cyclic olefin copolymer TOPAS 6013F-04, and cyclic olefin copolymer TOPAS 8007F-600.

3. A single-layer PET reflective film according to claim 2, characterized in that: The second protective coating is a UV-7600B hard optical film with a viscosity of 2000-4000mPa·s / 25°C, a molecular weight of 1400MW, a pencil hardness of 3H, and a curing shrinkage rate of 6.3%, or a UV-7640B hard optical film with a viscosity of 2000-5000mPa·s / 25°C, a molecular weight of 1500MW, a pencil hardness of 3H-4H, and a curing shrinkage rate of 6.6%, or a UV-7630B plastic hard coating with a viscosity of 3000-7000mPa·s / 25°C, a molecular weight of 2200MW, a pencil hardness of 3H, and a curing shrinkage rate of 6.4%.

4. A single-layer PET reflective film according to claim 3, characterized in that: The primer layer is a hardened coating of one of cyclic olefin copolymer TOPAS 9506F-04, cyclic olefin copolymer TOPAS 8007F-04, cyclic olefin copolymer TOPAS 8007F-400, cyclic olefin copolymer TOPAS 6013F-04 and cyclic olefin copolymer TOPAS 8007F-600.

5. A single-layer PET reflective film according to claim 4, characterized in that: The metal reflective layer comprises a thickness compensation layer evaporated or sputtered on the base coating layer and a silver reflective layer evaporated or sputtered on the thickness compensation layer, wherein the thickness of the thickness compensation layer is 60-200nm, and the thickness of the silver reflective layer is 60-120nm.

6. A single-layer PET reflective film according to claim 5, characterized in that: The thickness compensation layer is an aluminum metal layer evaporated or sputtered on the base coating, or a titanium metal layer evaporated or sputtered on the base coating, or an aluminum-titanium alloy layer sputtered on the base coating.

7. A single-layer PET reflective film according to claim 6, characterized in that: The thickness of the PET substrate is 75 μm, the thickness of the base coating is 1 μm, the thickness of the thickness compensation layer is 150 nm, the thickness of the silver reflective layer is 80 nm, the thickness of the first protective coating is 5 μm, and its refractive index n is 1.53, and the thickness of the second protective coating is 3 μm, and its refractive index n is 1.

5.

8. The single-layer PET reflective film according to claim 4, characterized in that: The metal reflection layer is a pure silver reflection layer.

9. The single-layer PET reflective film according to claim 8, characterized in that: The thickness of the PET substrate is 70 μm, the thickness of the base coating is 1 μm, the thickness of the pure silver reflective layer is 150 nm, the thickness of the first protective coating is 5 μm, and its refractive index n is 1.53, and the thickness of the second protective coating is 3 μm, and its refractive index n is 1.

5.

10. A backlight module, comprising a back plate, a light source, a light guide plate and a reflective film arranged in sequence, characterized in that: The reflective film is a single-layer PET reflective film as described in claim 7 or 9.

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