A high-efficiency thermal conductive UV-LED ink and preparation method thereof

Abstract

The present application provides a highly efficient thermally conductive UV-LED ink and a preparation method thereof, comprising 0.1-7% melamine-formaldehyde-modified MXene, 30-60% binder, 30-50% monomer, 1-10% photoinitiator, and 1-10% additive. The present invention uses melamine-formaldehyde resin to embed the MXene to improve the dispersibility of the MXene and solve the technical problem of poor compatibility between the MXene and the ink matrix. Supplemented with a binder, pigment, and various additives, the UV-LED thermally conductive ink is prepared. This not only effectively prevents the agglomeration of the MXene but also greatly improves the thermal conductivity of the thermally conductive ink. The thermal conductivity of the printed ink film in the planar direction is as high as 1.32 W / m·K.

Description

[0001] This application is a divisional application. The application number of the original application is 2021115569725, the application date is December 18, 2021, and the name of the invention is "A preparation method and application of high-efficiency thermally conductive UV-LED ink". Technical Field

[0002] The present invention belongs to the technical field of polymer inks, and in particular relates to a high-efficiency thermally conductive UV-LED ink and a preparation method thereof. Background Art

[0003] As 5G technology matures, electronic devices are increasingly miniaturized, highly integrated, and intelligent. The resulting heat accumulation has become a key factor affecting the lifespan of these devices. Numerous studies have shown that within the appropriate operating temperature range, the failure rate of electronic devices decreases by 4% for every 1°C drop in operating temperature. However, when the operating temperature rises by 20°C above the maximum set point, the failure rate rises to 100%. Therefore, the research and development of high-performance heat dissipation materials has become a crucial topic in the current electronic device application field.

[0004] Numerous scholars and research institutions have conducted extensive research on heat dissipation materials. Thermally conductive materials such as graphene, boron nitride, aluminum oxide, carbon nanotubes, and nanodiamonds have been developed and applied to electronic products, achieving promising results. However, when focusing on the commercialization of electronic products, it's not difficult to notice that another important issue is often overlooked: the ink printed on the outside of electronic products to provide information. When the ink is printed on the surface of an electronic product and dries, it forms a dense layer. The binder in the ink solidifies into a film, firmly adhering to the surface of the electronic device and hindering heat dissipation. Therefore, developing functional inks that can both meet the printing requirements of electronic products and effectively dissipate heat has become a critical task. This is where thermally conductive inks come into play. Thermally conductive inks are made by adding fillers or additives with thermally conductive properties to traditional inks to impart excellent thermal conductivity. Compared to traditional inks, UV-LED inks not only cure faster but also consume less energy. Combining them with thermally conductive fillers holds promise for developing new thermally conductive inks with high efficiency and fast drying.

[0005] Among the many thermally conductive fillers, graphene has a thermal conductivity of up to 5300W / m·K, but it is expensive and has been widely studied. Materials such as boron nitride and aluminum oxide are often added in large quantities when preparing thermal conductive inks, which will affect the basic performance of the ink. In contrast, Mxene, as a new type of two-dimensional material, has significant advantages such as strippability, high thermal conductivity, unique size effect, and strong heat dissipation capacity. In addition, its raw material, titanium aluminum carbide (Ti3AlC2) MAX, is relatively low in cost, making it a new material in the field of thermal conductivity and attracting widespread attention from academia and the business community. However, since Mxene is an inorganic filler, adding it directly to the ink matrix often has problems such as poor compatibility and difficulty in dispersion. Therefore, the thermal conductivity of the thermal conductive inks usually prepared is not ideal. Summary of the Invention

[0006] Aiming at the problem of poor compatibility between michaelene (Mxene) and ink matrix, the present invention provides a high-efficiency thermal conductive UV-LED ink and a preparation method thereof.

[0007] A high-efficiency thermally conductive UV-LED ink comprises, by weight percentage, 0.1-7% of melamine-formaldehyde modified Mxene, 30-60% of a connecting material, 30-50% of a monomer, 1-10% of a photoinitiator, and 1-10% of an auxiliary agent.

[0008] The melamine-formaldehyde modified Mxene is prepared by the following steps: synthesizing a melamine-formaldehyde prepolymer, exfoliating titanium aluminum carbide using a lithium fluoride acid solution to prepare Mxene, and in-situ polymerizing the melamine-formaldehyde prepolymer and the exfoliated Mxene to obtain the melamine-formaldehyde modified Mxene.

[0009] Principle of the present invention:

[0010] The in-situ polymerization of MXene by melamine-formaldehyde resin effectively reduces the agglomeration of MXene, improves the dispersibility of MXene in the ink, and greatly increases the thermal conductivity of the ink.

[0011] The melamine-formaldehyde modified Mxene is prepared by the following steps:

[0012] (1) adding melamine to a polar solution and stirring evenly, setting the temperature to 50-80° C., slowly adding a 30-40% formaldehyde solution by mass, adjusting the pH to 7-10 with a weak base, reacting for 1-2 hours, and after the reaction is complete, continuing to stir for 30-60 minutes, and allowing to stand to obtain a melamine-formaldehyde prepolymer;

[0013] (2) adding lithium fluoride to an acidic solution and stirring to dissolve, adding titanium aluminum carbide powder, stirring and reacting at 30-60° C. for 4-48 hours, washing with deionized water until the pH is between 5-9, placing in an ultrasonic cleaner for ultrasonic stripping for 5-60 minutes, setting the power to 100-400W, after the stripping is completed, centrifuging the reaction solution at 1000-10000 r / min for 10-30 minutes, removing the lower precipitate and placing it in a drying oven for drying to obtain Mxene;

[0014] (3) Adding Mxene to a polar solvent, ultrasonicating at 30-80° C. for 30-90 minutes to obtain a Mxene dispersion, and then adding the dispersion to the melamine-formaldehyde prepolymer obtained in step (1), stirring for 4-8 hours, setting the temperature to 50-100° C. and the stirring speed to 300-1000 r / min, filtering, and vacuum drying to obtain melamine-formaldehyde modified Mxene.

[0015] In the preparation method of melamine-formaldehyde modified Mxene as described above, the molar ratio of melamine to formaldehyde is 1:5-10.

[0016] In the preparation method of melamine-formaldehyde modified Mxene as described above, the mass ratio of lithium fluoride to titanium aluminum carbide is 1:1-10.

[0017] In the preparation method of melamine-formaldehyde modified Mxene as described above, the mass ratio of Mxene to melamine is 1:1-20.

[0018] In the preparation method of melamine-formaldehyde modified Mxene as described above, in step (1):

[0019] The polar solvent is water;

[0020] The solid content of the melamine after being added to the polar solvent is 5-30%;

[0021] The weak base is one of sodium carbonate, sodium bicarbonate or ammonia water.

[0022] The preparation method of melamine-formaldehyde modified Mxene as described above: In step (2):

[0023] The acidic solution is one of hydrochloric acid, sulfuric acid or nitric acid;

[0024] The concentration of the lithium fluoride acid solution is 1.00-20.00 mg / ml.

[0025] In the preparation method of melamine-formaldehyde modified Mxene as described above, in step (3):

[0026] The polar solvent is one of N,N-dimethylacetamide, N-methylpyrrolidone or isopropyl alcohol;

[0027] The concentration of the MXene dispersion is 0.08-10 mg / ml;

[0028] The power of the ultrasound is 100-325W;

[0029] The vacuum drying condition is preferably drying at a temperature of 25-100° C. for 4-20 hours.

[0030] The method for preparing the above-mentioned high-efficiency thermally conductive UV-LED ink comprises the following steps:

[0031] S1: Preparation of melamine-formaldehyde modified Mxene;

[0032] S2: By weight percentage, 0.1-7% of melamine-formaldehyde modified Mxene, 30-60% of a binder, 30-50% of a monomer, 1-10% of a photoinitiator, and 1-10% of an additive are placed in a container and dispersed at 3000-10000 rpm for 1-4 hours using a high-speed disperser;

[0033] S3: Use a three-roller mill to crush and grind for 1-8 hours, and finally filter with a 100-1000 mesh gauze to obtain high-efficiency thermal conductive UV-LED thermal conductive ink.

[0034] The high-efficiency thermally conductive UV-LED ink prepared by the above preparation method is used in the printing or packaging decoration fields of electronic appliances. Compared with the existing technology, the present invention has the following advantages:

[0035] The present application provides a highly efficient thermally conductive UV-LED ink. A melamine-formaldehyde prepolymer is first synthesized, and then titanium aluminum carbide is stripped using a lithium fluoride acid solution to prepare MXene. Finally, the melamine-formaldehyde prepolymer and the stripped MXene are in situ polymerized to obtain melamine-formaldehyde-modified MXene. The melamine-formaldehyde-modified MXene is then compounded with various ink components, ground, and filtered to obtain a highly efficient thermally conductive UV-LED ink. The present invention uses melamine-formaldehyde resin to encapsulate the MXene to improve its dispersibility and address the technical issue of poor compatibility between the MXene and the ink matrix. The UV-LED thermally conductive ink is then prepared by adding a binder, a pigment, and various additives. This ink effectively prevents MXene agglomeration and significantly improves the thermal conductivity of the thermally conductive ink. The printed ink film has a thermal conductivity of up to 1.32 W / m·K in the planar direction. The present application provides an application of a high-efficiency thermally conductive UV-LED ink, which can be used in the fields of printing and packaging decoration of electronic appliances. The present invention solves the problems of poor compatibility and difficulty in dispersion when MXene is added to the ink matrix. The prepared thermally conductive functional filler has the advantages of a small addition amount and good thermal conductivity, greatly improving the thermal conductivity coefficient of the ink. The preparation method of the high-efficiency thermally conductive UV-LED ink is simple in preparation process and highly operable. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for describing the embodiments.

[0037] Figure 1 These are the SEM images of Mxene and melamine-formaldehyde resin modified Mxene.

[0038] Figure 2 This is the infrared image of melamine-formaldehyde resin modified Mxene prepared in Example 5.

[0039] Figure 3 This is a thermal conductivity test chart of the high-efficiency thermal conductive UV-LED ink prepared in Example 5. DETAILED DESCRIPTION

[0040] The specific technical solutions of the present invention are described below in conjunction with specific embodiments 1-8:

[0041] Example 1

[0042] A method for preparing a high-efficiency thermally conductive UV-LED ink comprises the following steps:

[0043] (1) 6 g of melamine was added to 60 mL of deionized water and stirred at 300 r / min; then 14 mL of 37% formaldehyde solution was added dropwise, the pH was adjusted to 9 with a freshly prepared Na2CO3 (10%) solution, the temperature was raised to 80°C, and stirring was continued for 20 minutes to obtain a melamine-formaldehyde prepolymer;

[0044] (2) 1.0 g of lithium fluoride was added to 150 mL of HCl and stirred for 5 minutes. Subsequently, 2.0 g of titanium aluminum carbide powder was added and stirred at 30°C for 8 hours. The mixture was washed with deionized water until the pH was 5.5 and ultrasonically stripped in an ultrasonic cleaner for 10 minutes at a power of 200 W. After the stripping was completed, the reaction solution was centrifuged at 2000 r / min for 10 minutes. The lower precipitate was removed and dried in a drying oven to obtain Mxene.

[0045] (3) 1.0 g of Mxene was added to 300 mL of N-methylpyrrolidone, and ultrasonicated at 50 ° C for 40 minutes with a power of 250 W to obtain a Mxene dispersion, which was then added to the melamine-formaldehyde prepolymer prepared in step (1) and stirred for 3 hours. The temperature was set to 50 ° C and the stirring speed was 350 r / min. After filtering, the mixture was dried at 80 ° C for 2 hours to obtain melamine-formaldehyde modified Mxene (MF@Mxene);

[0046] (4) The melamine-formaldehyde modified Mxene (MF@Mxene) obtained in step (3), polyurethane acrylate, epoxy acrylate, diethylene glycol diacrylate, photoinitiator and leveling agent, defoamer, dispersant, and wetting agent were added into a high-speed disperser at a ratio of 0.5%, 35%, 15%, 35%, 8%, 2%, 1%, 1% and 2.5% relative to the total mass of the ink, respectively, and dispersed at 2000 r / min for 2 hours, then crushed and ground with a three-roll mill for 3 hours, and finally filtered with a 300-mesh gauze to obtain a high-efficiency thermally conductive UV-LED thermal conductive ink.

[0047] Example 2

[0048] A method for preparing a high-efficiency thermally conductive UV-LED ink comprises the following steps:

[0049] (1) 4 g of melamine was added to 40 mL of deionized water and stirred at 200 r / min; then 7.2 mL of 37% formaldehyde solution was added dropwise, the pH was adjusted to 8 with a freshly prepared Na2CO3 (10%) solution, the temperature was raised to 70°C, and stirring was continued for 30 minutes to obtain a melamine-formaldehyde prepolymer;

[0050] (2) 1.5 g of lithium fluoride was added to 200 mL of HCl and stirred for 10 minutes. Subsequently, 2.5 g of titanium aluminum carbide powder was added and stirred at 40°C for 10 hours. The mixture was washed with deionized water until the pH was 6 and ultrasonically stripped in an ultrasonic cleaner for 15 minutes at a power of 200 W. After the stripping was completed, the reaction solution was centrifuged at 2500 r / min for 15 minutes. The lower precipitate was removed and dried in a drying oven to obtain Mxene.

[0051] (3) 1.5 g of Mxene was added to 500 mL of N-methylpyrrolidone, and ultrasonicated at 40 ° C for 60 minutes with a power of 100 W to obtain a Mxene dispersion, which was then added to the melamine-formaldehyde prepolymer prepared in step (1), stirred for 4 hours, set the temperature to 50 ° C, and stirred at a speed of 400 r / min. After filtering, it was dried at 60 ° C for 8 hours to obtain melamine-formaldehyde modified Mxene (MF@Mxene);

[0052] (4) The melamine-formaldehyde modified Mxene (MF@Mxene) obtained in step (3), polyurethane acrylate, epoxy acrylate, diethylene glycol diacrylate, photoinitiator and leveling agent, defoamer, dispersant, and wetting agent were added into a high-speed disperser at a ratio of 1%, 35%, 10%, 45%, 3%, 2%, 1%, 1% and 2% relative to the total mass of the ink, respectively, and dispersed at 4000 r / min for 1 hour, then crushed and ground with a three-roll mill for 1 hour, and finally filtered with a 200-mesh gauze to obtain a high-efficiency thermally conductive UV-LED thermal conductive ink.

[0053] Example 3

[0054] A method for preparing a high-efficiency thermally conductive UV-LED ink comprises the following steps:

[0055] (1) 3 g of melamine was added to 35 mL of deionized water and stirred at 250 rpm. 7.5 mL of 37% formaldehyde solution was then added dropwise. The pH was adjusted to 10 with a freshly prepared 10% Na2CO3 solution. The mixture was heated to 60°C and stirred for 40 minutes to obtain a melamine-formaldehyde prepolymer.

[0056] (2) Add 2.0 g of lithium fluoride to 400 mL of HCl and stir for 15 minutes. Then add 5 g of titanium aluminum carbide powder and stir at 40°C for 15 hours. Wash with deionized water until the pH is 7 and ultrasonically strip for 20 minutes in an ultrasonic cleaner with a power setting of 300 W. After the stripping is completed, centrifuge the reaction solution at 3000 r / min for 10 minutes, remove the lower precipitate, and dry it in a drying oven to obtain Mxene.

[0057] (3) 4 g of Mxene was added to 450 mL of N-methylpyrrolidone, and ultrasonicated at 60 ° C for 30 minutes with a power of 150 W to obtain a Mxene dispersion, which was then added to the melamine-formaldehyde prepolymer prepared in step (1), stirred for 2 hours, set the temperature to 60 ° C, and stirred at a speed of 300 r / min. After filtering, it was dried at 70 ° C for 6 hours to obtain melamine-formaldehyde modified Mxene (MF@Mxene);

[0058] (4) The melamine-formaldehyde modified Mxene (MF@Mxene) obtained in step (3), polyurethane acrylate, epoxy acrylate, diethylene glycol diacrylate, photoinitiator and leveling agent, defoamer, dispersant, and wetting agent were added into a high-speed disperser at a ratio of 1.5%, 20%, 25%, 40%, 6%, 3.5%, 1.5%, 2% and 0.5% relative to the total mass of the ink, respectively, and dispersed at 3000 r / min for 2 hours, then crushed and ground with a three-roll mill for 2 hours, and finally filtered with a 200-mesh gauze to obtain a high-efficiency thermally conductive UV-LED thermal conductive ink.

[0059] Example 4

[0060] A method for preparing a high-efficiency thermally conductive UV-LED ink comprises the following steps:

[0061] (1) 10 g of melamine was added to 30 mL of deionized water and stirred at 300 r / min; then 18.9 mL of 37% formaldehyde solution was added dropwise, the pH was adjusted to 10 with a freshly prepared NaHCO3 (10%) solution, the temperature was raised to 70°C, and stirring was continued for 40 minutes to obtain a melamine-formaldehyde prepolymer;

[0062] (2) Add 2.5 g of lithium fluoride to 400 mL of HCl and stir for 20 minutes. Then add 6 g of titanium aluminum carbide powder and stir at 50°C for 20 hours. Wash with deionized water until the pH is 8 and ultrasonically strip for 30 minutes in an ultrasonic cleaner with a power setting of 300 W. After the stripping is completed, the reaction solution is centrifuged at 3500 r / min for 20 minutes. The lower precipitate is removed and dried in a drying oven to obtain Mxene.

[0063] (3) 4.5 g of Mxene was added to 450 mL of N-methylpyrrolidone, and ultrasonicated at 50 ° C for 60 minutes with a power of 350 W to obtain a Mxene dispersion, which was then added to the melamine-formaldehyde prepolymer prepared in step (1), stirred for 1 hour, set the temperature to 40 ° C, and stirred at a speed of 300 r / min. After filtering, it was dried at 70 ° C for 3 hours to obtain melamine-formaldehyde modified Mxene (MF@Mxene);

[0064] (4) The melamine-formaldehyde modified Mxene (MF@Mxene) obtained in step (3), polyurethane acrylate, epoxy acrylate, diethylene glycol diacrylate, photoinitiator and leveling agent, defoamer, dispersant, and wetting agent are added to a high-speed disperser in a ratio of 2%, 25%, 25%, 35%, 3%, 3.5%, 1%, 3.5% and 2% relative to the total mass of the ink, respectively, and dispersed at 3500r / min for 2 hours, then crushed and ground with a three-roll mill for 2 hours, and finally filtered with a 250-mesh gauze to obtain a high-efficiency thermal conductive UV-LED thermal conductive ink.

[0065] Example 5

[0066] A method for preparing a high-efficiency thermally conductive UV-LED ink comprises the following steps:

[0067] (1) 5 g of melamine was added to 60 mL of deionized water and stirred at 300 r / min; then 8.9 mL of 37% formaldehyde solution was added dropwise, the pH was adjusted to 10 with a freshly prepared Na2CO3 (10%) solution, the temperature was raised to 70°C, and stirring was continued for 60 minutes to obtain a melamine-formaldehyde prepolymer;

[0068] (2) 3.0 g of lithium fluoride was added to 500 mL of HCl and stirred for 10 minutes. Subsequently, 3.0 g of titanium aluminum carbide powder was added and stirred at 42°C for 24 hours. The mixture was washed with deionized water until the pH was 6 and ultrasonically stripped in an ultrasonic cleaner for 30 minutes at a power of 300 W. After the stripping was completed, the reaction solution was centrifuged at 3500 r / min for 30 minutes. The lower precipitate was removed and dried in a drying oven to obtain Mxene.

[0069] (3) 1.0 g of Mxene was added to 500 mL of N-methylpyrrolidone, and ultrasonicated at 50 ° C for 90 minutes with a power of 325 W to obtain a Mxene dispersion, which was then added to the melamine-formaldehyde prepolymer prepared in step (1) and stirred for 2 hours. The temperature was set to 50 ° C and the stirring speed was 300 r / min. After filtering, the mixture was dried at 80 ° C for 3 hours to obtain melamine-formaldehyde modified Mxene (MF@Mxene);

[0070] (4) The melamine-formaldehyde modified Mxene (MF@Mxene) obtained in step (3), polyurethane acrylate, epoxy acrylate, diethylene glycol diacrylate, photoinitiator and leveling agent, defoamer, dispersant, and wetting agent are added into a high-speed disperser in a ratio of 3%, 30%, 10%, 40%, 5%, 2%, 3%, 2% and 3% relative to the total mass of the ink, respectively, and dispersed at 3000 r / min for 2 hours, then crushed and ground with a three-roll mill for 2 hours, and finally filtered with a 250-mesh gauze to obtain a high-efficiency thermal conductive UV-LED thermal conductive ink.

[0071] Example 6

[0072] A method for preparing a high-efficiency thermally conductive UV-LED ink comprises the following steps:

[0073] (1) 8 g of melamine was added to 100 mL of deionized water and stirred at 500 r / min; then 15 mL of 37% formaldehyde solution was added dropwise, the pH was adjusted to 10 with a freshly prepared 10% ammonia solution, the temperature was raised to 60° C., and stirring was continued for 60 minutes to obtain a melamine-formaldehyde prepolymer;

[0074] (2) 4.0 g of lithium fluoride was added to 500 mL of HCl and stirred for 15 minutes. Subsequently, 6.0 g of titanium aluminum carbide powder was added and stirred at 45°C for 18 hours. The mixture was washed with deionized water until the pH was 9 and ultrasonically stripped in an ultrasonic cleaner for 30 minutes at a power of 150 W. After the stripping was completed, the reaction solution was centrifuged at 4000 r / min for 35 minutes. The lower precipitate was removed and dried in a drying oven to obtain Mxene.

[0075] (3) 4.0 g of Mxene was added to 500 mL of N-methylpyrrolidone, and ultrasonicated at 60 ° C for 40 minutes with a power of 300 W to obtain a Mxene dispersion, which was then added to the melamine-formaldehyde prepolymer prepared in step (1), stirred for 2.5 hours, set the temperature to 60 ° C, and stirred at a speed of 500 r / min. After filtering, it was dried at 60 ° C for 3 hours to obtain melamine-formaldehyde modified Mxene (MF@Mxene);

[0076] (4) The melamine-formaldehyde modified Mxene (MF@Mxene) obtained in step (3), polyurethane acrylate, epoxy acrylate, diethylene glycol diacrylate, photoinitiator and leveling agent, defoamer, dispersant, and wetting agent were added into a high-speed disperser at a ratio of 5%, 35%, 15%, 30%, 8%, 3%, 3%, 0.5% and 0.5% relative to the total mass of the ink, respectively, and dispersed at 3000 r / min for 2 hours, then crushed and ground with a three-roll mill for 3 hours, and finally filtered with a 500-mesh gauze to obtain a high-efficiency thermally conductive UV-LED thermal conductive ink.

[0077] Example 7

[0078] A method for preparing a high-efficiency thermally conductive UV-LED ink comprises the following steps:

[0079] (1) 6.5 g of melamine was added to 90 mL of deionized water and stirred at 800 rpm; then 18 mL of 37% formaldehyde solution was added dropwise, the pH was adjusted to 10 with a freshly prepared 10% ammonia solution, the temperature was raised to 75° C., and stirring was continued for 50 minutes to obtain a melamine-formaldehyde prepolymer;

[0080] (2) Add 5.0 g of lithium fluoride to 500 mL of HCl and stir for 30 minutes. Then add 6.0 g of titanium aluminum carbide powder and stir at 50°C for 36 hours. Wash with deionized water until the pH is 8 and ultrasonically strip for 15 minutes in an ultrasonic cleaner with a power setting of 250 W. After the stripping is completed, the reaction solution is centrifuged at 3000 r / min for 35 minutes. The lower precipitate is removed and dried in a drying oven to obtain Mxene.

[0081] (3) 5.0 g of Mxene was added to 500 mL of N-methylpyrrolidone, and ultrasonicated at 60 ° C for 60 minutes with a power of 300 W to obtain a Mxene dispersion, which was then added to the melamine-formaldehyde prepolymer prepared in step (1), stirred for 3 hours, set the temperature to 60 ° C, and stirred at a speed of 300 r / min. After filtering, the mixture was dried at 50 ° C for 2 hours to obtain melamine-formaldehyde modified Mxene (MF@Mxene);

[0082] (4) The melamine-formaldehyde modified Mxene (MF@Mxene) obtained in step (3), polyurethane acrylate, epoxy acrylate, diethylene glycol diacrylate, photoinitiator and leveling agent, defoamer, dispersant, and wetting agent were added into a high-speed disperser at a ratio of 6%, 30%, 15%, 35%, 4%, 3%, 2%, 2.5% and 2.5% relative to the total mass of the ink, respectively, and dispersed at 5000 r / min for 2 hours, then crushed and ground with a three-roll mill for 1 hour, and finally filtered with an 800-mesh gauze to obtain a high-efficiency thermally conductive UV-LED thermal conductive ink.

[0083] Example 8

[0084] A method for preparing a high-efficiency thermally conductive UV-LED ink comprises the following steps:

[0085] (1) 7 g of melamine was added to 120 mL of deionized water and stirred at 600 r / min; 20 mL of 37% formaldehyde solution was then added dropwise, the pH was adjusted to 9 with a freshly prepared 10% ammonia solution, the temperature was raised to 80° C., and stirring was continued for 60 minutes to obtain a melamine-formaldehyde prepolymer;

[0086] (2) 6.0 g of lithium fluoride was added to 800 mL of HCl and stirred for 40 minutes. Subsequently, 6.0 g of titanium aluminum carbide powder was added and stirred at 60° C. for 40 hours. The mixture was washed with deionized water until the pH was 7 and ultrasonically stripped in an ultrasonic cleaner for 25 minutes at a power of 300 W. After the stripping was completed, the reaction solution was centrifuged at 3500 r / min for 30 minutes. The lower precipitate was removed and dried in a drying oven to obtain Mxene.

[0087] (3) 5.0 g of Mxene was added to 350 mL of N-methylpyrrolidone, and ultrasonicated at 80 ° C for 40 minutes with a power of 300 W to obtain a Mxene dispersion, which was then added to the melamine-formaldehyde prepolymer prepared in step (1), stirred for 2 hours, set the temperature to 70 ° C, and stirred at a speed of 300 r / min. After filtering, the mixture was dried at 80 ° C for 2 hours to obtain melamine-formaldehyde modified Mxene (MF@Mxene);

[0088] (4) The melamine-formaldehyde modified Mxene (MF@Mxene) obtained in step (3), polyurethane acrylate, epoxy acrylate, diethylene glycol diacrylate, photoinitiator and leveling agent, defoamer, dispersant, and wetting agent were added into a high-speed disperser at a ratio of 7%, 35%, 13%, 35%, 8%, 0.5%, 0.5%, 0.5% and 0.5% relative to the total mass of the ink, respectively, and dispersed at 6000 r / min for 2 hours, then crushed and ground with a three-roll mill for 1.5 hours, and finally filtered with an 800-mesh gauze to obtain a high-efficiency thermally conductive UV-LED thermal conductive ink.

[0089] Effect embodiment

[0090] The raw material Mxene and the intermediate product melamine-formaldehyde functionalized Mxene in Example 1 were subjected to electron microscopy scanning. From the scanning electron microscopy images ( Figure 1 ) It can be seen that compared with Mxene, the surface of Mxene after being embedded in melamine-formaldehyde resin becomes very rough and obviously carries a lot of fine particles.

[0091] At the same time, the in-plane thermal conductivity coefficient of the high-efficiency thermal conductive UV-LED thermal conductive ink prepared in Examples 1-8 was tested and compared with the thermal conductive ink reported in the prior art (Table 1). As can be seen from Table 1, the thermal conductivity coefficient of the high-efficiency thermal conductive UV-LED ink prepared in the present invention is significantly higher than the thermal conductivity coefficient of the thermal conductive ink reported in the prior art even when the addition amount is extremely low.

[0092] Table 1 Comparison of thermal conductivity

[0093]

[0094] As can be seen from the test data in Table 1, the high-efficiency thermally conductive UV-LED ink of the present application, the thermal conductive filler melamine-formaldehyde modified Mxene can greatly improve the thermal conductivity of the ink by adding a small amount. When it is only 3.0wt%, the thermal conductivity of the ink film in the planar direction after printing is as high as 1.32W / m·K. The above Example 5 is a preferred embodiment of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principles of the present invention should be equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A highly efficient thermally conductive UV-LED ink, characterized in that: Calculated by weight percentage, it includes: 3% of melamine-formaldehyde modified Mxene, 30-60% of connecting material, 30-50% of monomer, 1-10% of photoinitiator, and 1-10% of auxiliary agent; The method for preparing the high-efficiency thermally conductive UV-LED ink comprises the following steps: S1: Preparation of melamine-formaldehyde modified Mxene; S2: melamine-formaldehyde modified Mxene, linker, monomer, photoinitiator, and additives are placed in a container according to weight percentage, and dispersed at 3000-10000 r / min for 1-4 hours using a high-speed disperser; S3: Use a three-roll mill to grind for 1-8 hours, and finally filter with a 100-1000 mesh gauze to obtain high-efficiency thermal conductive UV-LED thermal conductive ink; The melamine-formaldehyde modified Mxene is prepared by the following steps: (1) adding melamine to a polar solution and stirring evenly, wherein the polar solvent is water, and the solid content of the melamine after being added to the polar solvent is 5-30%, setting the temperature to 50-80°C, slowly adding a formaldehyde solution with a mass fraction of 30-40%, and adjusting the pH to between 7 and 10 with a weak base, wherein the weak base is sodium carbonate, sodium bicarbonate or ammonia water, and reacting for 1-2 hours. After the reaction is completed, stirring is continued for 30-60 minutes, and the mixture is allowed to stand to obtain a melamine-formaldehyde prepolymer; (2) lithium fluoride is added to an acidic solution and stirred to dissolve, wherein the acidic solution is one of hydrochloric acid, sulfuric acid or nitric acid, and the concentration of the lithium fluoride acid solution is 1.00-20.00 mg / ml, titanium aluminum carbide powder is added, stirred and reacted at 30-60°C for 4-48 hours, washed with deionized water until the pH is between 5-9, placed in an ultrasonic cleaner for ultrasonic stripping for 5-60 minutes, and the power is set to 100-400W. After the stripping is completed, the reaction solution is centrifuged at 1000-10000 r / min for 10-30 minutes, the lower layer of precipitate is removed and placed in a drying oven for drying to obtain Mxene; (3) Add Mxene to a polar solvent, wherein the polar solvent is one of N,N-dimethylacetamide, N-methylpyrrolidone or isopropanol, and ultrasonicate at 30-80°C for 30-90 minutes, wherein the ultrasonic power is 100-325W, to obtain a Mxene dispersion having a concentration of 0.08-10 mg / ml. Add the Mxene dispersion to the melamine-formaldehyde prepolymer prepared in step (1), stir for 4-8 hours, set the temperature to 50-100°C, stir at a speed of 300-1000 r / min, filter, and vacuum dry. The vacuum drying condition is drying at a temperature of 25-100°C for 4-20 hours to obtain melamine-formaldehyde modified Mxene.

2. The high-efficiency thermally conductive UV-LED ink according to claim 1, characterized in that: The molar ratio of melamine to formaldehyde is 1:5-10.

3. The high-efficiency thermally conductive UV-LED ink according to claim 1, characterized in that: The mass ratio of lithium fluoride to titanium aluminum carbide is 1:1-10.

4. The high-efficiency thermally conductive UV-LED ink according to claim 1, characterized in that: The mass ratio of Mxene to melamine is 1:1-20.

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