A reflective paper for uniformly reflective and wear-resistant lamps and its manufacturing method

Abstract

This application relates to the field of reflective paper technology, and in particular to a reflective paper for lamps with uniform reflectivity and wear resistance. The reflective paper comprises, from top to bottom, a wear-resistant layer, a protective layer, a heat insulation layer, a reflective layer, a base layer, and an adhesive layer. The wear-resistant layer contains nano-silica-graphene hybrid particles, which can perform a certain degree of self-repair when the wear-resistant layer is subjected to a certain degree of wear, thereby reducing micro-defects such as scratches and wear on the surface of the wear-resistant layer and making the reflection uniform.

Description

Technical Field

[0001] This application relates to the field of reflective paper technology, and in particular to a reflective paper for lamps with uniform reflectivity and wear resistance, and a method for manufacturing it. Background Technology

[0002] Reflective paper is used inside lighting modules to diffuse and concentrate light onto the emitting surface, thereby enhancing the brightness of the lighting fixture. The abrasion resistance of the reflective paper significantly affects the uniformity of reflection. If the reflective paper is easily worn, its surface will be damaged during installation inside the lighting fixture, reducing reflective uniformity and affecting the lighting effect.

[0003] In a type of tensile-resistant environmentally friendly reflective paper with announcement number CN207549609U, a protective layer, a heat insulation layer, a face film, a silver plating layer, a reinforcing layer, and a pressure-sensitive adhesive layer are arranged sequentially from top to bottom. The protective layer is made of polyester or polyethylene.

[0004] When the protective layer is scratched or worn, the reflected light from the silver plating layer is prone to unevenness, affecting the lighting quality of the lamp. Summary of the Invention

[0005] To further improve abrasion resistance and achieve uniform reflection, this application provides a reflective paper for abrasion-resistant lamps with uniform reflection and a manufacturing method.

[0006] Firstly, the reflective paper for a uniformly reflective and wear-resistant lamp provided in this application adopts the following technical solution.

[0007] A reflective paper for lamps with uniform reflectivity and wear resistance, comprising, from top to bottom, a wear-resistant layer, a protective layer, a heat insulation layer, a reflective layer, a base layer, and an adhesive layer, wherein the wear-resistant layer contains nano-silica-graphene hybrid particles.

[0008] Optionally, the particle size of the nano-silica-graphene hybrid particles is 20-50 nm.

[0009] Optionally, the wear-resistant layer includes a polyurethane matrix, the protective layer includes a UV-stabilized polyester, the reflective layer includes a silver-plated or aluminum-plated PET film, the heat insulation layer includes a silica aerogel-polyvinyl alcohol composite film, the base layer includes polycarbonate fiber paper, and the adhesive layer includes an acrylic pressure-sensitive adhesive.

[0010] By adopting the above technical solution, on the one hand, the nano-silica-graphene hybrid particles can improve the hardness of the wear-resistant layer and reduce the friction coefficient of the wear-resistant layer, making it less likely for large wear marks to appear on the surface of the wear-resistant layer. On the other hand, under the thermal activation effect of the heat generated when the lamp is working, for example, when the temperature is higher than 50°C, the graphene will migrate to the crack and fill the micro-defects through π-π accumulation, making the surface of the wear-resistant layer less susceptible to wear, thus ensuring uniformity of reflection.

[0011] Secondly, the method for manufacturing reflective paper for uniformly reflective and wear-resistant lamps provided in this application adopts the following technical solution.

[0012] A method for manufacturing reflective paper for lamps with uniform reflectivity and wear resistance, specifically including the following steps.

[0013] S1. Preparation of nano-silica-graphene hybrid particles;

[0014] S2. Prepare the wear-resistant layer, protective layer, heat insulation layer, reflective layer, base layer and adhesive layer;

[0015] S3. Apply the adhesive layer to the base layer;

[0016] S4. Hot-press the wear-resistant layer, protective layer, heat insulation layer, reflective layer, and base layer together;

[0017] S5. Separate, inspect, and package.

[0018] Optionally, the preparation of nano-silica-graphene hybrid particles in step S1 specifically includes the following steps:

[0019] S11. Disperse single-layer graphene oxide in a solution of deionized water and ethanol, and mix it evenly by ultrasonication.

[0020] S12. While stirring the solution obtained in S11, add tetraethyl orthosilicate dropwise, control the molar ratio of silicon dioxide to graphene oxide to be 10:1, adjust the pH to 9 with ammonia, and hydrolyze for 6 hours.

[0021] S13. Add hydrazine hydrate to the solution obtained in S12 to reduce it for 2 hours, and then centrifuge, wash and freeze dry to obtain nano-silica-graphene hybrid particles.

[0022] By adopting the above technical solution, the liquid-phase reduction of hydrazine hydrate can avoid the high-temperature calcination in the traditional graphene oxide reduction process, reduce the damage to the conjugated structure of graphene, and preserve the mechanical properties and self-healing ability of graphene as much as possible.

[0023] Optionally, before performing S13, 3-aminopropyltriethoxysilane is added to the solution obtained in S12 and refluxed at 80°C for 2 hours.

[0024] By adopting the above technical solution, 3-aminopropyltriethoxysilane coats silicon dioxide, so that the amino group of 3-aminopropyltriethoxysilane and the carboxyl group of graphene form an amide, so that the interface between silicon dioxide and graphene is less likely to oxidize at high temperatures, thereby reducing the light transmittance of the wear-resistant layer.

[0025] Optionally, the method for preparing the wear-resistant layer includes adding the nano-silica-graphene hybrid particle powder obtained in S1 to the polyurethane prepolymer, shearing it, then treating it under an alternating electric field to make the nano-silica-graphene hybrid particles monodisperse, and then performing vacuum degassing and adjusting the viscosity for later use.

[0026] By adopting the above technical solutions, the possibility of agglomeration of nano-silica-graphene hybrid particles is reduced, the optical haze of the wear-resistant layer is reduced, and the reflective performance of reflective paper is improved.

[0027] Optionally, the hot-pressing composite in step S4 specifically includes the following steps:

[0028] S41. Preheat at 60℃;

[0029] S42, Composite process is carried out at 120℃ and 0.4 MPa;

[0030] S43. Cool at 25°C.

[0031] By adopting the above technical solution, preheating makes it less likely for air bubbles to exist between the layers, and the temperature and pressure of the composite are controlled to be less than the deformation threshold of the base layer and the reflective layer, ensuring high-quality forming of the reflective paper.

[0032] In summary, this application includes at least the following beneficial effects:

[0033] 1. Under the thermal activation effect of the heat generated when the lamp is working, for example, when the temperature is higher than 50℃, graphene will migrate to the crack and fill the micro-defects through π-π accumulation, making the surface of the wear-resistant layer less susceptible to wear and ensuring uniform reflection.

[0034] 2. Hydrazine hydrate liquid-phase reduction can avoid the high-temperature calcination in the traditional graphene oxide reduction process, reduce the damage to the conjugated structure of graphene, and preserve the mechanical properties and self-healing ability of graphene as much as possible.

[0035] 3. 3-Aminopropyltriethoxysilane coats silica, so that the amino group of 3-aminopropyltriethoxysilane and the carboxyl group of graphene form an amide, so that the interface between silica and graphene is not easily oxidized at high temperatures, and the light transmittance of the wear-resistant layer is not easily reduced.

[0036] 4. During the preparation of the wear-resistant layer, the nano-silica-graphene hybrid particles are treated under an alternating electric field to make them monodisperse, reduce the possibility of agglomeration of the nano-silica-graphene hybrid particles, reduce the optical haze of the wear-resistant layer, and help improve the reflective performance of the reflective paper. Attached Figure Description

[0037] Figure 1This is a cross-sectional view of a uniformly reflective and wear-resistant reflective paper for lamps;

[0038] Figure 2 This is a flowchart illustrating the steps involved in manufacturing reflective paper for a uniformly reflective and wear-resistant lamp.

[0039] Explanation of reference numerals in the attached diagram: 1. Wear-resistant layer; 2. Protective layer; 3. Reflective layer; 4. Heat insulation layer; 5. Base layer; 6. Adhesive layer. Detailed Implementation

[0040] The present application will be further described in detail below with reference to the accompanying drawings.

[0041] This application discloses a reflective paper for lamps with uniform reflectivity and wear resistance, referring to... Figure 1 From top to bottom, it includes a wear-resistant layer 1, a protective layer 2, a heat insulation layer 4, a reflective layer 3, a base layer 5, and an adhesive layer 6. The wear-resistant layer 1 contains nano-silica-graphene hybrid particles with a particle size of 20-50nm.

[0042] This application also discloses a method for manufacturing reflective paper for uniformly reflective and wear-resistant lamps, referring to... Figure 2 Specifically, it includes the following steps.

[0043] S1. Preparation of nano-silica-graphene hybrid particles.

[0044] Specifically, it includes the following steps.

[0045] S11. Disperse 0.5 wt% of single-layer graphene oxide in a solution of deionized water and ethanol in a 1:1 ratio, and mix thoroughly by ultrasonication at 500 W for 30 min.

[0046] S12. While stirring the solution obtained in S11 at 40℃, add tetraethyl orthosilicate dropwise, control the molar ratio of silicon dioxide and graphene oxide to be 10:1, adjust the pH to 9 with ammonia, and hydrolyze for 6 hours.

[0047] S13. Add hydrazine hydrate to the solution obtained in S12 and control the temperature at 80℃ for reduction for 2 hours. Then, centrifuge, wash and freeze dry to obtain nano-silica-graphene hybrid particles.

[0048] Before proceeding with S13, 2 wt% of 3-aminopropyltriethoxysilane was added to the solution obtained in S12, and the solution was refluxed at 80°C for 2 h.

[0049] S2. Prepare wear-resistant layer 1, protective layer 2, heat insulation layer 4, reflective layer 3, base layer 5, and adhesive layer 6.

[0050] The preparation method of wear-resistant layer 1 is as follows: 5 phr of nano-silica-graphene hybrid particle powder obtained in S1 is weighed and added to a polyurethane prepolymer with a solid content of 40%. The mixture is subjected to high-speed shearing at 1500 rpm for 15 min. Then, it is treated under an AC electric field of 0.5 kV / cm for 10 min to make the nano-silica-graphene hybrid particles monodisperse. After vacuum degassing, the viscosity is adjusted to 1500-2000 cP at 25℃ before use.

[0051] The protective layer 2 can be prepared by selecting a 125µm UV co-extruded polyester film, subjecting it to corona treatment at 52 dyn / cm, then gravure coating it with a 2µm UV-curable acrylic varnish, and curing it with a 1 J / cm UV LED lamp.

[0052] The heat insulation layer 4 can be prepared by mixing silica aerogel powder with a particle size of 1-3µm with a 10% PVA aqueous solution at a mass ratio of 1:4, coating the mixture onto a release PET film with a thickness of 30µm using a doctor blade, freezing at -20℃ for 4 hours, thawing at 20℃ for 2 hours, and repeating this cycle twice to obtain a continuous porous membrane, and finally drying at 80℃ before peeling off.

[0053] The reflective layer 3 can be prepared by using a 12µm thick biaxially oriented PET, performing surface plasma cleaning, and then magnetron sputtering with a silver target at a power density of 3.5 W / cm². 2 An argon pressure of 0.4 Pa was used to obtain a 150 nm thick silver plating layer.

[0054] The preparation method of the base layer 5 is as follows: polycarbonate short chopped fibers with a diameter of 8µm and a length of 3mm are mixed with PC latex with a particle size of 120nm at a mass ratio of 7:3, and after wet papermaking, hot pressing is carried out at 120℃ for 5min to control the thickness to 100µm.

[0055] The adhesive layer 6 can be prepared by polymerizing butyl acrylate, 2-ethylhexyl acrylate, acrylic acid, and N-hydroxymethylacrylamide in a ratio of 65:30:3:2 to obtain a pressure-sensitive adhesive with a solid content of 45%.

[0056] S3. Apply the adhesive layer 6 to the base layer 5.

[0057] Add 0.3% isocyanate curing agent to the adhesive layer 6 prepared in S2, apply it to the release paper with a scraper, dry it at 90°C for 3 minutes, the thickness after drying is 25µm, and finally transfer it to the bottom surface of the base layer 5.

[0058] S4. Stack and hot-press the wear-resistant layer 1, protective layer 2, heat insulation layer 4, reflective layer 3, and base layer 5 in sequence from top to bottom, with the silver-plated side of the reflective layer 3 facing upwards and the side of the base layer 5 where the adhesive layer 6 is located facing downwards. The specific steps are as follows.

[0059] S41. Preheat at 60℃;

[0060] S42, Composite process is carried out at 120℃ and 0.4 MPa;

[0061] S43. Cool at 25°C.

[0062] S5. Separate, inspect, and package.

[0063] The following detailed description uses specific embodiments and comparative examples.

[0064] Example 1:

[0065] A reflective paper for lamps with uniform reflectivity and wear resistance includes, from top to bottom, a wear-resistant layer 1, a protective layer 2, a heat insulation layer 4, a reflective layer 3, a base layer 5, and an adhesive layer 6. The wear-resistant layer 1 contains nano-silica-graphene hybrid particles with a particle size of 20nm.

[0066] A method for manufacturing reflective paper for uniformly reflective and wear-resistant lamps includes the following steps.

[0067] S1. Preparation of nano-silica-graphene hybrid particles;

[0068] S2. Prepare wear-resistant layer 1, protective layer 2, heat insulation layer 4, reflective layer 3, base layer 5, and adhesive layer 6;

[0069] S3. Apply the adhesive layer 6 to the base layer 5;

[0070] S4. Hot-press the wear-resistant layer 1, protective layer 2, heat insulation layer 4, reflective layer 3, and base layer 5 together;

[0071] S5. Separate, inspect, and package.

[0072] Example 2:

[0073] The difference from Example 1 is that the particle size of the nano-silica-graphene hybrid particles is 50 nm.

[0074] Comparative Example 1:

[0075] The difference from Example 1 is that the wear-resistant layer 1 does not contain nano-silica-graphene hybrid particles.

[0076] Comparative Example 2:

[0077] The difference from Example 1 is that 3-aminopropyltriethoxysilane was not added to the solution obtained in S12 before S13.

[0078] Comparative Example 3:

[0079] The difference from Example 1 is that no alternating electric field treatment was performed during the preparation of wear-resistant layer 1.

[0080] Five samples of reflective paper obtained from each of the above embodiments and comparative examples were selected for the following index determination.

[0081] Total reflectance was measured using an integrating sphere spectrophotometer with a D65 standard light source, an incident angle of 8°, and a scanning wavelength of 380-780nm. The measurement result at a wavelength of 550nm was taken as the representative data output.

[0082] The uniformity of reflection was tested using a high-precision luminance meter and a 500mm×500mm integrating light source box. The silver-plated side of the sample was placed facing the light source, and the luminance meter was used to divide the sample surface into an 8×8 grid to obtain the luminance values ​​of 64 points. Then the average luminance and standard deviation were calculated. The standard deviation was divided by the average luminance to obtain the value of the uniformity of reflection. The smaller the value, the more uniform the reflection.

[0083] Both of the above indicators were measured before and after wear. The wear test was performed using a rotary abrasion tester with a grinding wheel load of 500g, a rotation speed of 60rpm, a stroke of 1000 revolutions, a test temperature of 23℃, and a relative humidity of 50%RH. After the wear treatment, a second test of total reflectivity and reflectivity uniformity was conducted. Then, the samples were placed under 450nm light at 60℃ for 12 hours before a third test of total reflectivity and reflectivity uniformity was performed.

[0084] To measure the wear track depth, after the sample underwent the same wear treatment, a white light interferometer was used to scan the center of the wear track, and the average depth was recorded. After placing the sample under the same conditions, a second wear track depth measurement was performed.

[0085] The specific results are shown in the table below.

[0086]

[0087] As can be seen from Examples 1 and 2 and Comparative Example 1, graphene will migrate to the cracks under the thermal activation effect of the heat generated when the lamp is working, and fill the micro-defects through π-π accumulation, so that the surface of the wear-resistant layer 1 is not easily worn, thus ensuring the uniformity of reflection.

[0088] As can be seen from Examples 1 and 2 and Comparative Example 2, 3-aminopropyltriethoxysilane coats silicon dioxide, causing the amino group of 3-aminopropyltriethoxysilane and the carboxyl group of graphene to form an amide. This makes it less likely for oxidation to occur at high temperatures at the interface between silicon dioxide and graphene, thus preventing the light transmittance of the wear-resistant layer 1 from decreasing. It also helps to improve the bonding strength between the nano-silica-graphene hybrid particles and the matrix.

[0089] As can be seen from Examples 1 and 2 and Comparative Example 3, the wear-resistant layer 1 is treated under an alternating electric field during preparation to make the nano-silica-graphene hybrid particles monodisperse, reduce the possibility of agglomeration of nano-silica-graphene hybrid particles, reduce the optical haze of the wear-resistant layer 1, and help improve the reflective performance of reflective paper.

[0090] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A reflective paper for lamps with uniform reflectivity and wear resistance, characterized in that: From top to bottom, it includes a wear-resistant layer (1), a protective layer (2), a heat insulation layer (4), a reflective layer (3), a base layer (5), and an adhesive layer (6). The wear-resistant layer (1) contains nano-silica-graphene hybrid particles.

2. The reflective paper for uniformly reflective and wear-resistant lamps according to claim 1, characterized in that: The particle size of the nano-silica-graphene hybrid particles is 20-50 nm.

3. The reflective paper for uniformly reflective and wear-resistant lamps according to claim 2, characterized in that: The wear-resistant layer (1) includes a polyurethane matrix, the protective layer (2) includes a UV-stabilized polyester, the reflective layer (3) includes a silver-plated PET film, the heat insulation layer (4) includes a silica aerogel-polyvinyl alcohol composite film, the base layer (5) includes polycarbonate fiber paper, and the adhesive layer (6) includes an acrylic pressure-sensitive adhesive.

4. A method for manufacturing reflective paper for lamps with uniform reflectivity and wear resistance, comprising manufacturing the reflective paper for lamps with uniform reflectivity and wear resistance as described in any one of claims 1-3, characterized in that: Specifically, the steps include the following: S1. Preparation of nano-silica-graphene hybrid particles; S2. Prepare wear-resistant layer (1), protective layer (2), heat insulation layer (4), reflective layer (3), base layer (5) and adhesive layer (6); S3. Apply the adhesive layer (6) to the base layer (5); S4. The wear-resistant layer (1), protective layer (2), heat insulation layer (4), reflective layer (3), and base layer (5) are hot-pressed together; S5. Separate, inspect, and package.

5. The method for manufacturing reflective paper for a uniformly reflective and wear-resistant lamp according to claim 4, characterized in that: The preparation of nano-silica-graphene hybrid particles by S1 specifically includes the following steps: S11. Disperse single-layer graphene oxide in a solution of deionized water and ethanol, and mix it evenly by ultrasonication. S12. While stirring the solution obtained in S11, add tetraethyl orthosilicate dropwise, control the molar ratio of silicon dioxide to graphene oxide to be 10:1, adjust the pH to 9 with ammonia, and hydrolyze for 6 hours. S13. Add hydrazine hydrate to the solution obtained in S12 to reduce it for 2 hours, and then centrifuge, wash and freeze dry to obtain nano-silica-graphene hybrid particles.

6. The method for manufacturing reflective paper for a uniformly reflective and wear-resistant lamp according to claim 5, characterized in that: Before performing S13, 3-aminopropyltriethoxysilane is added to the solution obtained in S12 and refluxed at 80°C for 2 hours.

7. The method for manufacturing reflective paper for a uniformly reflective and wear-resistant lamp according to claim 4, characterized in that: The method for preparing the wear-resistant layer (1) includes adding the nano-silica-graphene hybrid particle powder obtained in S1 into the polyurethane prepolymer and shearing it, then treating it under an alternating electric field to make the nano-silica-graphene hybrid particles monodisperse, and then performing vacuum degassing and adjusting the viscosity for later use.

8. The method for manufacturing reflective paper for a uniformly reflective and wear-resistant lamp according to claim 4, characterized in that: The hot-pressing composite process in S4 specifically includes the following steps: S41. Preheat at 60℃; S42, Composite process is carried out at 120℃ and 0.4 MPa; S43. Cool at 25°C.

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