A modified ink for improving the reflectivity of a substrate of a multi-primary color LED lighting fixture and a preparation method thereof

Abstract

The present invention discloses a modified ink for improving the reflectivity of a substrate of a multi-primary color LED lighting fixture and a preparation method thereof, and belongs to the field of ink technology. The modified ink of the present invention is prepared from raw materials including: 18-26 parts of reflective powder, 35-60 parts of organosilicon-modified acrylic resin, 10-16 parts of biphenyl-type liquid crystal epoxy resin, 5-8 parts of photoinitiator, 3-6 parts of curing agent, 1.5-5 parts of antioxidant, 0.5-1 parts of leveling agent, and 30-40 parts of solvent. The present invention adopts composite-coated core-shell titanium dioxide as reflective powder, and prepares a modified ink in combination with organosilicon-modified acrylic resin and biphenyl-type liquid crystal epoxy resin. The modified ink can reach a reflectivity of more than 96% at a thickness of 30 μm, has excellent yellowing resistance, helps to improve light efficiency utilization rate, reduces energy consumption, and can be used to prepare high-brightness, high-stability high-quality LED lamps.

Description

Technical Field

[0001] The present invention belongs to the technical field of inks, and in particular relates to a modified ink for improving the reflectivity of a substrate of a multi-primary-color LED lighting fixture and a preparation method thereof. Background Art

[0002] Multi-primary color LEDs (RGBW and RGBY) are considered a core trend in next-generation lighting due to their wide color gamut, high color rendering, and dynamic dimming capabilities. However, the low reflectivity of traditional package substrates (approximately 60%-90%) results in significant loss of luminous efficacy. Currently, reflective materials, such as reflective inks, are used to create reflective layers to enhance the focusing effect of LED lights.

[0003] The luminous efficiency of LED lamps is highly dependent on the reflectivity of the reflective material. Research has shown that highly reflective fillers such as rutile titanium dioxide can effectively improve reflectivity. Furthermore, the matrix resin, which acts as a bonding agent, is also crucial for maintaining high reflectivity. However, conventional reflective inks not only have relatively thick coatings but also exhibit significant scattering losses. Furthermore, the organic resin matrix is susceptible to yellowing under subsequent high-temperature conditions, leading to light color shift and a significant decrease in reflectivity over time. Long-term thermal loads (such as LED chip heating and reflow soldering) can also generate carbonyl chromophores, causing irreversible light decay and severely limiting lamp life.

[0004] In view of this, in order to prepare multi-primary color LED lamps with high brightness, high contrast and high stability, it is necessary to conduct further in-depth research on reflective inks. Summary of the Invention

[0005] In response to the issues raised in the background art, the present invention aims to provide a modified ink for improving the reflectivity of substrates used in multi-primary-color LED lighting fixtures, and a method for preparing the same. By optimizing the combination of reflective filler and matrix resin, the present invention produces a modified ink that effectively improves reflectivity and yellowing resistance, meeting the performance requirements of high-quality LED lamps and promising applications in high-end fields such as Mini / Micro LEDs.

[0006] To achieve the above object, the present invention specifically adopts the following technical solutions:

[0007] The present invention provides a modified ink for improving the reflectivity of a substrate of a multi-primary color LED lighting fixture, which comprises the following raw materials in parts by weight:

[0008] 18-26 parts of reflective powder,

[0009] 35-60 parts of silicone modified acrylic resin,

[0010] 10-16 parts of biphenyl type liquid crystal epoxy resin,

[0011] 5-8 parts of photoinitiator,

[0012] 3-6 parts of curing agent,

[0013] 1.5-5 parts of antioxidant,

[0014] 0.5-1 part of leveling agent,

[0015] 30-40 parts of solvent;

[0016] The reflective powder includes core-shell titanium dioxide coated with yttrium, erbium and tellurium.

[0017] Furthermore, the reflective powder is composed of core-shell titanium dioxide coated with yttrium, erbium and tellurium and fumed silicon dioxide in a mass ratio of (2-5):1, and the particle size of the reflective powder is 100-200 mesh.

[0018] Furthermore, the preparation method of the yttrium, erbium and tellurium coated core-shell titanium dioxide is as follows: anatase titanium dioxide nanoparticles are dispersed in deionized water, yttrium nitrate and urea are added and stirred at a constant temperature, followed by centrifugation and calcination to obtain Y2O3-coated TiO2; the product is further dispersed in a solution of erbium nitrate and polyvinyl pyrrolidone, the pH is adjusted and stirred at a constant temperature, followed by centrifugation and calcination to obtain Y2O3 and Er2O3-coated TiO2; the product is then dispersed in an ethanol aqueous solution of tellurium nitrate, the pH is adjusted and stirred at a constant temperature, followed by centrifugation and calcination to finally obtain core-shell TiO2 compositely coated with yttrium, erbium and tellurium.

[0019] Furthermore, the molar ratio of titanium, yttrium, erbium and tellurium is 100:(8-12):(0.4-0.5):(0.09-0.12).

[0020] Furthermore, the organosilicon-modified acrylic resin is prepared by a hydrosilylation reaction of triethylene glycol dimethacrylate and phenyl hydrogenated silicone resin.

[0021] Furthermore, the biphenyl type liquid crystal epoxy resin is prepared by curing with 3,3',5,5'-tetramethylbiphenyl diglycidyl ether, and the curing agent used is 4,4'-diaminodiphenylmethane.

[0022] Furthermore, the curing agent is an acid anhydride curing agent, preferably MH-700.

[0023] Furthermore, the photoinitiator is at least one of photoinitiator TPO, photoinitiator ITX or photoinitiator 184; and the antioxidant is 4,6-bis(octylthiomethyl)-o-cresol.

[0024] The present invention also provides a method for preparing the modified ink for improving the reflectivity of the substrate of a multi-primary color LED lighting fixture, comprising:

[0025] Weigh all raw materials according to the formula, and except for the photoinitiator and curing agent, mix the remaining raw materials at high speed and disperse them, then add the photoinitiator and curing agent and mix them evenly with a homogenizer, and obtain the modified ink after grinding and filtering.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. The present invention uses yttrium, erbium, and tellurium to sequentially coat anatase titanium dioxide to construct a core-shell structure. The composite coating shell layer can improve dispersibility, enhance interface scattering efficiency, block ultraviolet light penetration, and enhance material stability. Through the core-shell structure design, the present invention improves light efficiency utilization and achieves a significant increase in reflectivity.

[0028] 2. The modified ink of the present invention uses silicone-modified acrylic resin as the base resin and the main film-forming substance, which provides basic adhesion, enhances heat resistance and flexibility, and at the same time, contains phenyl silicone to ensure basic yellowing resistance. The present invention also compounded and uses a biphenyl-type liquid crystal epoxy resin, which can improve the optical anisotropy of the ink and enhance the reflection uniformity. It is combined with the silicone-modified acrylic resin to construct a dual-cure system, further improving the crosslinking density and reflectivity.

[0029] 3. According to the reflectivity test, the reflectivity of the modified ink of the present invention can reach 96%-99%, and it also has excellent yellowing resistance, which is significantly improved compared with traditional reflective inks. It can be used to prepare high-brightness, high-stability, high-quality LED lamps and has good market competitiveness. DETAILED DESCRIPTION

[0030] To make the objects, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be described clearly and completely below in conjunction with the examples. Where specific conditions are not specified in the examples, the experiments were carried out under conventional conditions or the conditions recommended by the manufacturer. Where the manufacturer of the reagents or instruments is not specified, all are commercially available conventional products.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art in the art. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0032] Example 1

[0033] A modified ink for improving the reflectivity of a substrate of a multi-primary color LED lighting fixture, the preparation method of which is as follows:

[0034] 1. Take anatase titanium dioxide nanoparticles and disperse them in deionized water. Add yttrium nitrate (yttrium to titanium molar ratio 1:10) and urea and stir at 80℃ for 6 h. The product is centrifuged and washed, and then calcined at 520℃ for 1 h to obtain Y2O3-coated TiO2. Continue to disperse the Y2O3-coated TiO2 in a solution of erbium nitrate (erbium to yttrium molar ratio 5:95) and polyvinyl pyrrolidone, adjust the pH to 9 and stir at 70℃ for 4 h. The product is centrifuged and washed, and then calcined at 500℃ for 1.5 h to obtain Y2O3 and Er2O3-coated TiO2. Then, disperse the Y2O3 and Er2O3-coated TiO2 in an ethanol aqueous solution of tellurium nitrate (tellurium to erbium molar ratio 1:5), adjust the pH to 6 and stir at 60℃ for 3 h. The product is centrifuged and washed, and then calcined at 360℃ for 1 h. h, and finally obtain core-shell TiO2 coated with yttrium, erbium and tellurium.

[0035] 2. Mix 10 parts by weight of triethylene glycol dimethacrylate with 0.01 parts by weight of platinum catalyst, then add 7.5 parts by weight of phenyl hydrogenated silicone resin, heat to 90°C, and stir continuously for 3 hours to obtain a silicone-modified acrylic resin. Separately, dissolve 10 parts by weight of 3,3',5,5'-tetramethylbiphenyl diglycidyl ether and 1.8 parts by weight of 4,4'-diaminodiphenylmethane in an appropriate amount of dichloromethane. Pour the mixture into a mold, evacuate, and wait until the solvent evaporates completely. Curing at 100°C for 3 hours, 150°C for 2 hours, and 200°C for 1 hour in sequence to obtain a biphenyl-based liquid crystal epoxy resin.

[0036] 3. Weigh by weight 22 parts of reflective powder (composed of core-shell TiO2 and fumed silica in a 4:1 mass ratio from Step 1), 48 parts of organosilicon-modified acrylic resin, 14 parts of biphenyl-type liquid crystal epoxy resin, 7 parts of photoinitiator (composed of photoinitiator TPO and photoinitiator 184 in equal mass ratios), 5 parts of MH-700, 2.5 parts of 4,6-bis(octylthiomethyl)-o-cresol, 0.8 parts of leveling agent BYK-333, and 36 parts of ethyl acetate. Mix and disperse the reflective powder, organosilicon-modified acrylic resin, biphenyl-type liquid crystal epoxy resin, antioxidant, leveling agent, and solvent at high speed. Then add the photoinitiator and curing agent, mix thoroughly with a homogenizer, grind, and filter to obtain a modified ink.

[0037] Example 2

[0038] A modified ink for improving the reflectivity of a substrate of a multi-primary color LED lighting fixture, the preparation method of which is as follows:

[0039] 1. Take anatase titanium dioxide nanoparticles and disperse them in deionized water. Add yttrium nitrate (yttrium to titanium molar ratio 1:10) and urea and stir at 80℃ for 6 h. The product is centrifuged and washed, and then calcined at 520℃ for 1 h to obtain Y2O3-coated TiO2. Continue to disperse the Y2O3-coated TiO2 in a solution of erbium nitrate (erbium to yttrium molar ratio 5:100) and polyvinyl pyrrolidone, adjust the pH to 9 and stir at 70℃ for 4 h. The product is centrifuged and washed, and then calcined at 500℃ for 1.5 h to obtain Y2O3 and Er2O3-coated TiO2. Then, disperse the Y2O3 and Er2O3-coated TiO2 in an ethanol aqueous solution of tellurium nitrate (tellurium to erbium molar ratio 1.2:5), adjust the pH to 6 and stir at 60℃ for 3 h. The product is centrifuged and washed, and then calcined at 360℃ for 1 h. h, and finally obtain core-shell TiO2 coated with yttrium, erbium and tellurium.

[0040] 2. Mix 10 parts by weight of triethylene glycol dimethacrylate with 0.01 parts by weight of platinum catalyst, then add 7.5 parts by weight of phenyl hydrogenated silicone resin, heat to 90°C, and stir continuously for 3 hours to obtain a silicone-modified acrylic resin. Separately, dissolve 10 parts by weight of 3,3',5,5'-tetramethylbiphenyl diglycidyl ether and 1.8 parts by weight of 4,4'-diaminodiphenylmethane in an appropriate amount of dichloromethane. Pour the mixture into a mold, evacuate, and wait until the solvent evaporates completely. Curing at 100°C for 3 hours, 150°C for 2 hours, and 200°C for 1 hour in sequence to obtain a biphenyl-based liquid crystal epoxy resin.

[0041] 3. Weigh by weight 18 parts of reflective powder (composed of core-shell TiO2 and fumed silica in a 5:1 mass ratio from Step 1), 35 parts of organosilicon-modified acrylic resin, 10 parts of biphenyl-type liquid crystal epoxy resin, 5 parts of photoinitiator (composed of photoinitiator TPO and photoinitiator 184 in equal mass ratios), 3 parts of MH-700, 1.5 parts of 4,6-bis(octylthiomethyl)-o-cresol, 0.5 parts of leveling agent BYK-333, and 30 parts of ethyl acetate. Mix and disperse the reflective powder, organosilicon-modified acrylic resin, biphenyl-type liquid crystal epoxy resin, antioxidant, leveling agent, and solvent at high speed. Then add the photoinitiator and curing agent, mix thoroughly with a homogenizer, grind, and filter to obtain a modified ink.

[0042] Example 3

[0043] A modified ink for improving the reflectivity of a substrate of a multi-primary color LED lighting fixture, the preparation method of which is as follows:

[0044] 1. Take anatase titanium dioxide nanoparticles and disperse them in deionized water. Add yttrium nitrate (yttrium to titanium molar ratio 1:10) and urea and stir at 80℃ for 6 h. The product is centrifuged and washed, and then calcined at 520℃ for 1 h to obtain Y2O3-coated TiO2. Continue to disperse the Y2O3-coated TiO2 in a solution of erbium nitrate (erbium to yttrium molar ratio 4:100) and polyvinyl pyrrolidone, adjust the pH to 9, and stir at 70℃ for 4 h. The product is centrifuged and washed, and then calcined at 500℃ for 1.5 h to obtain Y2O3 and Er2O3-coated TiO2. Then, disperse the Y2O3 and Er2O3-coated TiO2 in an ethanol aqueous solution of tellurium nitrate (tellurium to erbium molar ratio 0.9:4), adjust the pH to 6, and stir at 60℃ for 3 h. The product is centrifuged and washed, and then calcined at 360℃ for 1 h. h, and finally obtain core-shell TiO2 coated with yttrium, erbium and tellurium.

[0045] 2. Mix 10 parts by weight of triethylene glycol dimethacrylate with 0.01 parts by weight of platinum catalyst, then add 7.5 parts by weight of phenyl hydrogenated silicone resin, heat to 90°C, and stir continuously for 3 hours to obtain a silicone-modified acrylic resin. Separately, dissolve 10 parts by weight of 3,3',5,5'-tetramethylbiphenyl diglycidyl ether and 1.8 parts by weight of 4,4'-diaminodiphenylmethane in an appropriate amount of dichloromethane. Pour the mixture into a mold, evacuate, and wait until the solvent evaporates completely. Curing at 100°C for 3 hours, 150°C for 2 hours, and 200°C for 1 hour in sequence to obtain a biphenyl-based liquid crystal epoxy resin.

[0046] 3. Weigh by weight 26 parts of reflective powder (composed of core-shell TiO2 and fumed silica in a 4:1 mass ratio from Step 1), 60 parts of organosilicon-modified acrylic resin, 16 parts of biphenyl-type liquid crystal epoxy resin, 8 parts of photoinitiator (composed of photoinitiator TPO and photoinitiator 184 in equal mass ratios), 6 parts of MH-700, 4 parts of 4,6-bis(octylthiomethyl)-o-cresol, 1 part of leveling agent BYK-333, and 40 parts of ethyl acetate. Mix and disperse the reflective powder, organosilicon-modified acrylic resin, biphenyl-type liquid crystal epoxy resin, antioxidant, leveling agent, and solvent at high speed. Then add the photoinitiator and curing agent, mix thoroughly with a homogenizer, grind, and filter to obtain a modified ink.

[0047] Comparative Example 1

[0048] Refer to the step parameters of Example 1, except that the intermediate products Y2O3 and Er2O3 of Step 1 are used to coat TiO2 and fumed silica to form the reflective powder.

[0049] Comparative Example 2

[0050] The step parameters are as described in Example 1, except that bisphenol A epoxy resin is used in step 2 instead of biphenyl liquid crystal epoxy resin.

[0051] Comparative Example 3

[0052] Refer to the step parameters of Example 1, except that in step 3, 22 parts of rutile titanium dioxide are directly used as the reflective powder.

[0053] Test example

[0054] White ink was tested by screen printing (30 μm thickness) on an aluminum substrate (HQ-R18129) using an 80-mesh steel mesh. 2 After 2 minutes of UV irradiation, the coating was then cured in a tunnel oven at 230°C for 5 minutes to produce a reflective coating. The performance of the ink samples prepared above was tested, with the results shown in Table 1. (Adhesion was tested using the crosshatch method; reflectivity was tested using a C84-111 reflectometer. High-temperature yellowing resistance was tested by baking in a 280°C oven for 10 minutes; weathering yellowing resistance was tested by irradiating with a UVA-340 lamp for 168 hours at an irradiance of 0.68 W / m².) 2 The reflow resistance test is to place the coating in a 280°C oven for 10 minutes, and the reflectivity is considered passed if it decreases by no more than 5%).

[0055] Table 1 Test results of modified ink

[0056]

[0057] The test results in Table 1 show that the coating samples prepared using the modified inks of Examples 1-3 of the present invention all exhibit high reflectivity and excellent yellowing resistance. At a thickness of 30 μm, the reflectivity reaches over 96%, and both yellowing resistance and reflow resistance tests are passed, demonstrating excellent overall performance. Comparative Example 1, which uses Y2O3 and Er2O3-coated TiO2 as a reflective powder, exhibits significantly lower reflectivity, and its yellowing resistance, hardness, and whiteness are also reduced to varying degrees. This demonstrates that the core-shell titanium dioxide composite coated with yttrium, erbium, and tellurium of the present invention effectively improves the reflectivity of the coating. Comparative Example 2, which uses a silicone-modified acrylic resin combined with a bisphenol A epoxy resin to prepare the modified ink, exhibits a smaller decrease in reflectivity, but significantly reduces reflectivity (over 10%) in the yellowing resistance and reflow resistance tests. This demonstrates that the biphenyl-based liquid crystal epoxy resin prepared by the present invention effectively improves the yellowing resistance of the coating. Compared with traditional rutile titanium dioxide, the coating samples prepared with the reflective powder of the present invention still have significant advantages in reflectivity and yellowing resistance, which helps to improve light efficiency utilization and reduce energy consumption, and can be used to prepare high-brightness, high-stability high-quality LED lamps.

[0058] Finally, it should be emphasized that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various changes and modifications. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A modified ink for improving the reflectivity of a substrate of a multi-primary color LED lighting fixture, characterized in that: The following raw materials are included in the preparation by weight: 18-26 parts of reflective powder, 35-60 parts of silicone modified acrylic resin, 10-16 parts of biphenyl type liquid crystal epoxy resin, 5-8 parts of photoinitiator, 3-6 parts of curing agent, 1.5-5 parts of antioxidant, 0.5-1 part of leveling agent, 30-40 parts of solvent; The reflective powder includes core-shell titanium dioxide coated with yttrium, erbium and tellurium. The preparation method of the core-shell titanium dioxide coated with yttrium, erbium and tellurium is as follows: taking anatase titanium dioxide nanoparticles and dispersing them in deionized water, adding yttrium nitrate and urea and stirring at a constant temperature, then centrifuging and calcining to obtain Y2O3-coated TiO2; continuing to disperse the product in a solution of erbium nitrate and polyvinyl pyrrolidone, adjusting the pH and stirring at a constant temperature, then centrifuging and calcining to obtain Y2O3 and Er2O3-coated TiO2; then dispersing the product in an ethanol aqueous solution of tellurium nitrate, adjusting the pH and stirring at a constant temperature, then centrifuging and calcining to finally obtain core-shell TiO2 coated with yttrium, erbium and tellurium.

2. The modified ink for improving the reflectivity of a multi-primary color LED lighting fixture substrate according to claim 1, characterized in that: The reflective powder is composed of core-shell titanium dioxide coated with yttrium, erbium and tellurium and fumed silicon dioxide in a mass ratio of (2-5):

1.

3. The modified ink for improving the reflectivity of a multi-primary color LED lighting fixture substrate according to claim 1, characterized in that: The molar ratio of titanium, yttrium, erbium and tellurium is 100:(8-12):(0.4-0.5):(0.09-0.12).

4. The modified ink for improving the reflectivity of a substrate of a multi-primary color LED lighting fixture according to claim 1, characterized in that: The organosilicon-modified acrylic resin is prepared by the hydrosilylation reaction of triethylene glycol dimethacrylate and phenyl hydrogenated silicone resin.

5. The modified ink for improving the reflectivity of a substrate of a multi-primary color LED lighting fixture according to claim 1, characterized in that: The biphenyl type liquid crystal epoxy resin is prepared by curing with 3,3',5,5'-tetramethylbiphenyl diglycidyl ether, and the curing agent used is 4,4'-diaminodiphenylmethane.

6. The modified ink for improving the reflectivity of a substrate of a multi-primary color LED lighting fixture according to claim 1, characterized in that: The curing agent is an acid anhydride curing agent.

7. The modified ink for improving the reflectivity of a substrate of a multi-primary color LED lighting fixture according to claim 1, characterized in that: The photoinitiator is at least one of photoinitiator TPO, photoinitiator ITX or photoinitiator 184; the antioxidant is 4,6-bis(octylthiomethyl)-o-cresol.

8. The method for preparing the modified ink for improving the reflectivity of a substrate of a multi-primary color LED lighting fixture according to any one of claims 1 to 7, characterized in that: include: Weigh all raw materials according to the formula, and except for the photoinitiator and curing agent, mix the remaining raw materials at high speed and disperse them, then add the photoinitiator and curing agent and mix them evenly with a homogenizer, and obtain the modified ink after grinding and filtering.

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