Silver reflector for backlight module with corrected color coordinates and preparation method thereof

Abstract

The invention discloses a silver reflector of a backlight module for correcting color coordinates and a preparation method thereof. The silver reflector comprises a first PET layer, an acrylic glue pre-coating layer, a silver-plated layer, a laminating layer, an aluminum-plated layer and a second PET layer which are arranged in sequence from one side to the other side. The pre-coating layer contains blue quantum dot particles or blue fluorescent polystyrene microsphere particles. The method adopts the blue quantum dots or blue fluorescent polystyrene microspheres to correct the CIE1931 color coordinate X value or Y value of the silver reflector to between 0.28 and 0.295. The silver reflector which is slightly biased towards blue light can achieve white balance of the entire LCD system after passing through a module and a color filter.

Description

Technical Field

[0001] The present invention relates to the technical field of optical films, and more particularly to a silver reflective sheet of a backlight module for correcting color coordinates and a preparation method thereof. Background Art

[0002] The LCD display uses RGB combination, with three primary colors: red, blue and green. Figure 1 On the CIE1931xy color coordinates, the coordinate (0.3, 0.3) indicates positive white light, but because the reflection will pass through the module and color filter, the system correction hue will be slightly blue light to achieve the white balance of the entire system. In LCD design, the color coordinate value in the reflector will be slightly smaller, about 0.295-0.280, to meet the overall definition of white light that meets commercial and industry standards. The current conventional idea for blue correction of this reflector is to add a color change factor (such as blue pigment) to correct it, but this correction method is difficult to accurately control the amount of pigment particles due to the large size, and the color change uniformity is poor, so it is difficult to achieve the expected blue correction color. Summary of the invention

[0003] To solve the problems raised in the above background technology, the present invention provides a.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A silver reflector for a backlight module with corrected color coordinates comprises a first PET layer, a pre-coating layer, a silver-plated layer, a laminating layer, an aluminum-plated layer and a second PET layer which are arranged in sequence from one side to the other side, wherein the pre-coating layer contains blue quantum dot particles or blue fluorescent polystyrene microsphere particles.

[0006] In some embodiments of the silver reflective sheet of the backlight module for correcting the color coordinates of the present invention, the thickness of the first PET layer is 23-50 μm.

[0007] In some embodiments of the silver reflective sheet of the backlight module for correcting the color coordinates of the present invention, the thickness of the second PET layer is 23-75 μm.

[0008] In some embodiments of the silver reflector of the backlight module for correcting the color coordinates of the present invention, the blue quantum dot particles are ZnCdS quantum dot particles, and the emission wavelength thereof is 400-420 nm, and the half-peak width is ≤20 nm.

[0009] In some embodiments of the silver reflective sheet of the backlight module for correcting the color coordinates of the present invention, the thickness of the silver-plated layer is 50-150 nm, and the thickness of the aluminum-plated layer is 20-70 nm.

[0010] A method for preparing a silver reflector for a backlight module with corrected color coordinates comprises the following steps:

[0011] Step a, preparing the pre-coating main body material: uniformly mix the following components in mass percentage: 15% propylene glycol methyl ether, 8% butyl acrylate, 16% butyl methacrylate, 25% methyl methacrylate, 6% methacrylic acid, 5% styrene, 3% initiator Tx21S, 1% dimethylethanolamine, and 21% toluene to obtain the main body material;

[0012] Step b, adding 3%-5% of curing agent to the above-mentioned main material and ethyl ester in a ratio of 1:5 and mixing evenly to obtain acrylic glue pre-coating material;

[0013] Step c, adding blue quantum dots or blue fluorescent polystyrene microspheres into the acrylic glue pre-coating raw material at a mass percentage of 0.03%, 0.05%, or 0.1% to prepare a mixed solution;

[0014] Step d, preparing a first PET layer, and then coating the mixed solution obtained in step c on the first PET layer using a micro-dimpled coater at a machine speed of 305 m / min and a baking temperature of 110 degrees Celsius to obtain a pre-coating layer on the first PET layer;

[0015] Step e, silver-plating the pre-coated surface on the first PET layer obtained in step d by using a coating machine, the thickness of the silver-plated layer is 100 nm, the silver-plating power is 7.5 KW, and the coating machine speed is 135 m / min, to obtain a PET silver film;

[0016] Step f, preparing a second PET layer, and using a coating machine to plate aluminum on the second PET layer, the thickness of the aluminum coating layer is 45 nm, the silver plating power is 12.6 KW, and the coating machine speed is 300 m / min, to obtain a PET aluminum film;

[0017] Step h, compounding the PET silver film obtained in step e with the PET aluminum film obtained in step f, using polyurethane glue, and laminating the two on a laminating machine at 85 degrees Celsius and a machine speed of 37 meters per minute to obtain a reflective sheet with corrected color coordinates.

[0018] In some embodiments of the preparation method of the silver reflective sheet of the present invention, the blue quantum dots are ZnCdS quantum dots, the emission peak wavelength is 400-420nm, and the half-peak width is less than 20nm. The ZnCdS quantum dots are dispersed in the toluene at a concentration of 1000mg / L to form a mixed solution, and the mixed solution is then added into 20L of acrylic glue at mass percentages of 0.03%, 0.05%, and 0.1%, respectively.

[0019] In some embodiments of the method for preparing the silver reflective sheet of the present invention, the blue fluorescent polystyrene microspheres are dispersed in the toluene at a concentration of 10000 mg / L to form a mixed solution, and the mixed solution is then added to 20 L of acrylic glue at mass percentages of 0.03%, 0.05%, and 0.1%, respectively.

[0020] In some embodiments of the method for preparing the silver reflective sheet of the present invention, the curing agent is an acrylic curing aid of the Green Photomer brand of Corning, an American company.

[0021] Specifically, the CIE1931 color coordinate X value or Y value of the silver reflective sheet is 0.28-0.295.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows: the blue quantum dots and blue fluorescent polystyrene microspheres used in the present invention have a blue hue when reflected, which can meet various module adjustments. This method can adjust and match different hue requirements and also meet the maximum brightness requirement at the same time; the silver reflector of the backlight module with corrected color coordinates of the present invention uses blue quantum dots or blue fluorescent polystyrene microspheres, which are mixed into the acrylic glue pre-coating layer, and finally coated and cured between the first PET layer and the silver-plated layer, so that the entire silver reflector has a slight blue hue. The silver reflector of the backlight module with corrected color coordinates is installed on the LCD backlight module, which can make the entire display system reach white balance (positive white light); through the hue correction scheme of the present invention, various module adjustments can also be met. This method can adjust and match different hue requirements and also meet the maximum brightness requirement at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of CIE1931 xy color coordinates.

[0024] Figure 2 It is a schematic diagram of the cross-sectional structure of the reflector of the present invention. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Embodiment 1: Using blue quantum dots;

[0027] Step a. Preparation of a pre-coating main body material: The following components in percentage by mass: 15% propylene glycol methyl ether, 8% butyl acrylate, 16% butyl methacrylate, 25% methyl methacrylate, 6% methacrylic acid, 5% styrene, 3% initiator Tx21S, 1% dimethylethanolamine, and 21% toluene are uniformly mixed to obtain a main body material;

[0028] Step b, adding 3%-5% of curing agent to the above-mentioned main material and ethyl ester in a ratio of 1:5 and mixing evenly to obtain acrylic glue pre-coating material;

[0029] Step c, dispersing ZnCdS quantum dots with an emission peak wavelength of 400-420 nm and a half-peak width of less than 20 nm in the toluene at a concentration of 1000 mg / L to form a mixed solution, and then adding the mixed solution into 20 L of acrylic glue pre-coating raw material at mass percentages of 0.03%, 0.05%, and 0.1% three times to obtain a mixed solution;

[0030] The effective concentration of ZnCdS is as follows:

[0031] 0.03％ 0.05％ 0.1％ ZnCdS effective concentration (mg) 6 10 20

[0032] Step d, preparing a first PET layer, and then coating the mixed solution obtained in step c on the first PET layer using a micro-dimpled coater at a machine speed of 305 m / min and a baking temperature of 110 degrees Celsius to obtain a pre-coating layer on the first PET layer;

[0033] Step e, on the surface of the pre-coated layer on the first PET layer obtained in step d, silver-plating is performed by using a coating machine, the thickness of the silver-plated layer is 100 nm, the silver-plating power is 7.5 KW, and the coating machine speed is 135 m / min, to obtain a PET silver film;

[0034] Step f, preparing a second PET layer, and using a coating machine to plate aluminum on the second PET layer, the thickness of the aluminum coating layer is 45 nm, the silver plating power is 12.6 KW, and the coating machine speed is 300 m / min, to obtain a PET aluminum film;

[0035] Step h, compounding the PET silver film obtained in step e with the PET aluminum film obtained in step f, using polyurethane glue, and laminating the two on a laminating machine at 85 degrees Celsius and a machine speed of 37 meters per minute to obtain a reflective sheet with corrected color coordinates.

[0036] Example 2: Using blue fluorescent polystyrene microspheres;

[0037] In step c, the blue fluorescent polystyrene microspheres are dispersed in the toluene at a concentration of 10000 mg / L to form a mixed solution, and then the mixed solution is added into 20L acrylic glue at a mass percentage of 0.03%, 0.05% and 0.1%, respectively.

[0038]

[0039] The other steps in the second embodiment are the same as those in the first embodiment and will not be described in detail here.

[0040] Test conditions and experimental results:

[0041] Test conditions: The test conditions are based on the industry standard for optical films of LCD backlight modules, and refer to GB / T1740-2007 or ISO 4611:2010.

[0042] The experimental results are shown in the following table:

[0043] Table 1: Using blue quantum dots;

[0044] concentration x y Δx Δy Brightness Brightness increase / decrease ratio 0.03 0.29235 0.28731 -0.00979 -0.0031 8,223 0.41 0.05 0.29221 0.28432 -0.00993 -0.00609 8,205 0.18 0.1 0.29135 0.28123 -0.01079 -0.00918 8,214 0.29 GF-80W3 0.30214 0.29041 0 0 8,190 -

[0045] Table 2: Blue fluorescent polystyrene microspheres were used;

[0046]

[0047]

[0048] Note: In the above two tables,

[0049] (1) GF-80W3 is a white silver reflective film currently sold on the market by Guangzhi Company. The test light source is a 19V / 0.04A LED light source, and the test equipment is a ZeroLight CF600 brightness tester.

[0050] (2) Δx and Δy are the differences from GF-80W3, defined as Δx = (x-0.30214) and Δy = (y-0.29041) respectively.

[0051] Data description: Using blue quantum dots and blue fluorescent polystyrene microspheres in acrylic glue pre-coating,

[0052] 1) The △x reduction values ​​of ZnCdS blue quantum dots are quite consistent, and are reduced to -0.00979, -0.00993 and -0.01079 compared with the original test of GF-80W3 without quantum dots;

[0053] (2) The use of ZnCdS blue quantum dots showed a linear trend in the reduction of △y, which was -0.0031, -0.00609 and -0.00918 compared with the original test of GF-80W3 without quantum dots;

[0054] (3) The brightness change of ZnCdS blue quantum dots is slightly improved by about 0.41%, 0.18% and 0.29% higher than GF-80W3;

[0055] (4) The △x reduction values ​​using blue fluorescent polystyrene microspheres were quite consistent, decreasing to -0.00092, -0.00095, and -0.00099 compared to the original test of GF-80W3 without quantum dots;

[0056] (5) The △y reduction value using blue fluorescent polystyrene microspheres showed a linear trend, which was reduced to -0.00126, -0.00133 and -0.00163 compared with the original test of GF-80W3 without quantum dots;

[0057] (6) The change in brightness when using blue fluorescent polystyrene microspheres is slightly lower, about -0.16%, -0.71% and -0.82% lower than GF-80W3. The brightness reduction will decrease with the increase of microspheres, but it is still within the acceptable range;

[0058] Therefore, the optimal condition range of using ZnCdS quantum dots is 0.03-0.1%. The optimal condition is 0.1%, and the y value is reduced to 0.28123, which is -0.00918 less than that without adding ZnCdS quantum dots. The next best is 0.05%, and the next best is 0.03%.

[0059] When using blue fluorescent polystyrene microspheres, the optimal condition range is 0.03-0.1%. The optimal condition is 0.1%, and y is reduced to 0.28878, which is -0.00163 lower than that without adding microspheres. The next best condition is 0.05%, and the next best is 0.03%.

[0060] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a silver reflector for a backlight module with corrected color coordinates, characterized in that: The steps include: Step a, preparing a pre-coating main body material; uniformly mixing the following components in mass percentage: 15% propylene glycol methyl ether, 8% butyl acrylate, 16% butyl methacrylate, 25% methyl methacrylate, 6% methacrylic acid, 5% styrene, 3% initiator Tx21S, 1% dimethylethanolamine, and 21% toluene to obtain a main body material; Step b, adding 3%-5% of curing agent to the above-mentioned main material and ethyl ester in a ratio of 1:5 and mixing evenly to obtain acrylic glue pre-coating material; Step c, adding blue quantum dots or blue fluorescent polystyrene microspheres into the acrylic glue pre-coating raw material at a mass percentage of 0.03%, 0.05%, and 0.1% to prepare a mixed solution; Step d, preparing a first PET layer, and then coating the mixed solution obtained in step c on the first PET layer using a micro-dimpled coater at a machine speed of 305 m / min and a baking temperature of 110 degrees Celsius to obtain a pre-coating layer on the first PET layer; Step e, silver-plating the pre-coated surface on the first PET layer obtained in step d by using a coating machine, the thickness of the silver-plated layer is 100 nm, the silver-plating power is 7.5 KW, and the coating machine speed is 135 m / min, to obtain a PET silver film; Step f, preparing a second PET layer, and using a coating machine to plate aluminum on the second PET layer, the thickness of the aluminum coating layer is 45 nm, the silver plating power is 12.6 KW, and the coating machine speed is 300 m / min, to obtain a PET aluminum film; Step h, compounding the PET silver film obtained in step e with the PET aluminum film obtained in step f, using polyurethane glue, and laminating the two on a laminating machine at 85 degrees Celsius and a machine speed of 37 meters per minute to obtain a reflective sheet with corrected color coordinates.

2. The method for preparing a silver reflector for a backlight module with corrected color coordinates according to claim 1, characterized in that: The blue quantum dots are ZnCdS quantum dots, with an emission peak wavelength of 400-420 nm and a half-peak width of less than 20 nm. The ZnCdS quantum dots are dispersed in the toluene at a concentration of 1000 mg / L to form a mixed solution, and the mixed solution is then added into 20 L of acrylic glue at mass percentages of 0.03%, 0.05% and 0.1%, respectively.

3. The method for preparing a silver reflector for a backlight module with corrected color coordinates according to claim 1, characterized in that: The blue fluorescent polystyrene microspheres are dispersed in the toluene at a concentration of 10000 mg / L to form a mixed solution, and then the mixed solution is added into 20 L of acrylic glue at mass percentages of 0.03%, 0.05% and 0.1%, respectively.

4. The method for preparing a silver reflector for a backlight module with corrected color coordinates according to claim 1, characterized in that: The curing agent is an acrylic curing aid of the Green Photomer brand from Corning, an American company.

5. A silver reflective sheet for a backlight module with corrected color coordinates prepared by the preparation method according to claim 1, comprising a first PET layer, a pre-coating layer, a silver-plated layer, a laminating layer, an aluminum-plated layer, and a second PET layer sequentially arranged from one side to the other side, characterized in that: The pre-coating layer contains blue quantum dot particles or blue fluorescent polystyrene microsphere particles.

6. The silver reflector of a backlight module for correcting color coordinates according to claim 5, characterized in that: The thickness of the first PET layer is 23-50 μm.

7. The silver reflector of a backlight module for correcting color coordinates according to claim 5, characterized in that: The thickness of the second PET layer is 23-75 μm.

8. The silver reflector of a backlight module for correcting color coordinates according to claim 5, characterized in that: The blue quantum dot particles are ZnCdS quantum dot particles, the emission wavelength of which is 400-420nm and the half-peak width is ≤20nm.

9. The silver reflector of a backlight module for correcting color coordinates according to claim 5, characterized in that: The thickness of the silver-plated layer is 50-150 nm, and the thickness of the aluminum-plated layer is 20-70 nm.

10. The silver reflector of a backlight module for correcting color coordinates according to claim 5, characterized in that: The CIE1931 color coordinate X value or Y value of the silver reflective sheet is 0.28-0.295.

Images