Photocuring organic quantum dot mixed ink and preparation method thereof

Abstract

The invention provides light-cured organic quantum dot mixed ink and a preparation method thereof. The light-cured organic quantum dot mixed ink is prepared from the following components in parts by mass: 3 to 5 parts of epoxy resin, 5 to 10 parts of polyurethane resin, 60 to 70 parts of acrylic ester, 6 to 10 parts of isopropyl acrylamide, 1 to 5 parts of organic modified carbon quantum dots, 0.5 to 2 parts of cadmium sulfide, 0.5 to 2 parts of cadmium telluride, 5 to 10 parts of pigment, 1 to 5 parts of filler, 2 to 8 parts of photoinitiator and 0.1 to 2 parts of dispersing agent. Wherein the organic modified carbon quantum dots are carbon quantum dots of which the surfaces are grafted with vinyl benzene. The compatibility among various components is greatly improved, and the components can be crosslinked to form a stable three-dimensional structure, so that various properties of the ink are improved, the problems in the prior art are solved, and the ink has a good application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of inks, and in particular to a photocurable organic quantum dot mixed ink and a preparation method thereof. Background Art

[0002] UV (ultraviolet) curing ink can cure quickly under ultraviolet radiation and firmly adhere to the surface of the substrate. Compared with traditional inks, this ink has many advantages, including faster curing speed, less volatile substances and a wider range of uses. Because of this, UV curing ink has been used in many fields: this type of product is compatible with various types of UV flatbed inkjet equipment to achieve high-precision image printing; it is suitable for printing materials such as labels and packaging to enhance the quality and visual recognition of the product; it is also commonly used to make advertising signs and vehicle advertisements, etc.

[0003] As an emerging nanoscale material, carbon quantum dots exhibit excellent optical, dielectric and thermal conductivity properties, including high fluorescence efficiency, tunable fluorescence emission spectrum and excellent thermal and electrical conductivity. These properties make carbon quantum dots have broad application potential in many fields such as biomarker imaging, optoelectronic device detection, display semiconductor technology and photovoltaic solar cells.

[0004] There are many reports on the application of carbon quantum dots in inks in the prior art, such as CN107057463A, which mixes water-soluble carbon quantum dot aqueous dispersion, alcohol, water-based resin and surfactant to obtain water-based ultraviolet fluorescent anti-counterfeiting ink; CN109593524A uses radiata pine carbon quantum dot solution as fluorescent colorant, a mixed solution of ethanol, ethylene glycol, glycerol and deionized water as solvent, sodium carboxymethyl cellulose as binder and stabilizer, polyvinyl pyrrolidone solution as surfactant, and obtains fluorescent ink by a simple miscibility method. However, the above technical solutions directly mix carbon quantum dots with resin and other components, and the compatibility between carbon quantum dots and components such as resin, monomer and filler is poor, which makes the components easy to agglomerate, unevenly dispersed, and not stable and tight enough, so the performance of the ink cannot reach the ideal level.

[0005] In summary, it is urgent to develop a new technical solution to solve the problems existing in the prior art. Summary of the invention

[0006] In the photocurable organic quantum dot mixed ink and preparation method thereof provided by the present invention, organic modified carbon quantum dots are compounded with epoxy resin, polyurethane resin, acrylate and other components, which greatly improves the compatibility between the various components, and the components can be cross-linked to form a stable three-dimensional structure, thereby improving various properties of the ink and solving the problems existing in the prior art.

[0007] One object of the present invention is to provide a photocurable organic quantum dot mixed ink, wherein the photocurable organic quantum dot mixed ink comprises the following components in parts by weight:

[0008]

[0009]

[0010] in,

[0011] The organically modified carbon quantum dots are carbon quantum dots with vinylbenzene grafted on the surface.

[0012] Furthermore, the preparation method of the organic modified carbon quantum dots comprises the following steps:

[0013] The carbon quantum dots, vinyl chloride benzene and a catalyst are mixed and heated for reaction to obtain organically modified carbon quantum dots.

[0014] Furthermore, the carbon quantum dots are amino carbon quantum dots.

[0015] Furthermore, the heating reaction is carried out at a temperature of 70-100°C and a time of 2-10h.

[0016] Furthermore, the mass ratio of the carbon quantum dots to vinyl chloride benzene is (1-3):1.

[0017] Further, the acrylate includes trimethylolpropane triacrylate and 1,6-hexanediol diacrylate.

[0018] Furthermore, the pigment is selected from one or more of carbon black, phthalocyanine blue, titanium dioxide, pigment red, and pigment yellow.

[0019] Furthermore, the particle size of the filler is 10-100 nm.

[0020] Furthermore, the photoinitiator is selected from polymerizable photoinitiators containing carbon-carbon double bonds.

[0021] Another object of the present invention is to provide a method for preparing the above-mentioned photocurable organic quantum dot mixed ink, comprising the following steps:

[0022] Epoxy resin, polyurethane resin, acrylate, isopropyl acrylamide, organic modified carbon quantum dots, cadmium sulfide, cadmium telluride, pigment, filler, photoinitiator and dispersant are mixed and ground to obtain photocurable organic quantum dot mixed ink.

[0023] The present invention has the following beneficial effects:

[0024] The photocurable organic quantum dot hybrid ink of the present invention contains organic modified carbon quantum dots, which are obtained by reacting amino carbon quantum dots and vinyl chloride benzene. Multiple vinyl benzene groups are introduced on the surface of carbon quantum dots, thereby enhancing the compatibility between carbon quantum dots and organic resins and acrylates, which not only helps to enhance the hardness of the ink coating, but also can be further cross-linked with epoxy resin, polyurethane resin, trimethylolpropane triacrylate, 1,6-hexanediol diacrylate, polymerizable photoinitiator and other components through double bonds. The more stable body network structure formed by cross-linking of multiple components greatly improves the stability and strength of the ink. The multiple active groups introduced also make the ink have better adhesion. The modified carbon quantum dots also have a larger specific surface area, which helps to adsorb cadmium sulfide and cadmium telluride particles, and play a dispersing and stabilizing role. In addition, the introduction of carbon quantum dots also gives the ink better thermal conductivity and fluorescence properties. In summary, the photocurable organic quantum dot hybrid ink of the present invention solves the problems and deficiencies in the prior art and has good application prospects. DETAILED DESCRIPTION

[0025] In order to more clearly illustrate the technical solution of the present invention, the following examples are listed. Unless otherwise stated, the raw materials, reactions and post-treatment methods shown in the examples are common raw materials on the market and technical methods well known to those skilled in the art.

[0026] The words "preferred", "preferably", "more preferably", etc. in the present invention refer to embodiments of the present invention that can provide certain beneficial effects in certain circumstances. However, other embodiments may also be preferred under the same circumstances or other circumstances. In addition, the description of one or more preferred embodiments does not imply that other embodiments are not applicable, nor is it intended to exclude other embodiments from the scope of the present invention.

[0027] It should be understood that, except in any operating examples, or where otherwise indicated, all numbers indicating, for example, the amounts of ingredients used in the specification and claims should be understood to be modified in all cases by the term "about". Therefore, unless indicated to the contrary, the numerical parameters set forth in the following specification and the appended claims are approximate values ​​that vary depending on the desired properties to be obtained by the present invention.

[0028] The epoxy resin in the embodiment of the present invention is epoxy acrylate oligomer, Sartomer CN153; the polyurethane resin is polyurethane acrylate oligomer, Sartomer CU216NS.

[0029] The filler in the embodiment of the present invention is silicon dioxide with an average particle size of 50-100 nm.

[0030] The photoinitiator in the embodiment of the present invention is a polymerizable photoinitiator DAHTX, and the preparation method refers to the method described in the literature "Xiao Yahui, Fu Tao, Wu Jingjing, et al. Synthesis and performance study of polymerizable single-component thioxanthone photoinitiators [J]. Coatings Industry, 2020 (1): 9-13."

[0031] The carbon quantum dots in the embodiment of the present invention are amination carbon quantum dots, and the preparation method comprises the following steps:

[0032] 2.1 g of citric acid monohydrate and 1.8 g of urea were added to 20 mL of water, dissolved by ultrasonication, heated at 160° C. for 4 h, centrifuged and filtered, and then cold ethanol was added for precipitation. After washing and drying, amino carbon quantum dots were obtained.

[0033] The dispersant in the embodiment of the present invention is SD381.

[0034] The method for preparing organically modified carbon quantum dots in the embodiment of the present invention comprises the following steps:

[0035] Using isopropanol and water in a volume ratio of 10:1 as solvent, carbon quantum dots, K2CO3, tetrabutylammonium bromide and p-chloromethylstyrene in a mass ratio of 1:1.7:0.04:1 are mixed, reacted at 80°C for 6 hours under nitrogen protection, the solvent is removed under reduced pressure, and then sufficient isopropanol is added and stirred to dissolve. After filtering out the insoluble K2CO3, the isopropanol is removed to obtain organically modified carbon quantum dots.

[0036] The "parts" in the embodiments of the present invention refer to parts by mass.

[0037] Example 1

[0038] A photocurable organic quantum dot mixed ink, the photocurable organic quantum dot mixed ink comprising the following components in parts by weight:

[0039]

[0040] The method for preparing the photocurable organic quantum dot mixed ink comprises the following steps:

[0041] The components were mixed and stirred evenly according to the above mass fractions, and ground through a 1 μm filter membrane to obtain a photocurable organic quantum dot mixed ink.

[0042] Example 2

[0043] A photocurable organic quantum dot mixed ink, the photocurable organic quantum dot mixed ink comprising the following components in parts by weight:

[0044]

[0045]

[0046] The method for preparing the photocurable organic quantum dot mixed ink comprises the following steps:

[0047] The components were mixed and stirred evenly according to the above mass fractions, and ground through a 1 μm filter membrane to obtain a photocurable organic quantum dot mixed ink.

[0048] Example 3

[0049] A photocurable organic quantum dot mixed ink, the photocurable organic quantum dot mixed ink comprising the following components in parts by weight:

[0050]

[0051] The method for preparing the photocurable organic quantum dot mixed ink comprises the following steps:

[0052] The components were mixed and stirred evenly according to the above mass fractions, and ground through a 1 μm filter membrane to obtain a photocurable organic quantum dot mixed ink.

[0053] Comparative Example 1

[0054] A photocurable organic quantum dot mixed ink. The difference between this comparative example and Example 1 is that the organic modified carbon quantum dots are replaced by unmodified carbon quantum dots of equal mass, and the amounts of other components and the preparation method are the same as those in Example 1.

[0055] Comparative Example 2

[0056] A photocurable organic quantum dot mixed ink. The difference between this comparative example and Example 1 is that the photoinitiator is replaced by an equal mass of photoinitiator 184, and the amounts of other components and the preparation method are the same as those in Example 1.

[0057] Test Case

[0058] Test method:

[0059] The ink prepared in the examples and comparative examples was photocured and printed on a BOPP plastic film with a surface energy of 38 dynes using a printer with an Epson S3200 nozzle. The rotational viscosity of the printing ink was 5-10 mPa·s at 30 rpm at a temperature of 45°C. The UV-LED lamp (20 W / cm 2 ) Perform light curing at 395nm and observe whether the printed sample is clear.

[0060] Use the 100-grid method to test the ink adhesion. If there is no or little shedding, it is qualified, otherwise it is unqualified.

[0061] The sample is bent 180° with the ink layer as the outer side. If no obvious cracks are found, the bending resistance is qualified; otherwise, it is unqualified.

[0062] The sample was immersed in 5wt% HCl or NaOH solution for 24h, taken out for observation, and if no obvious bubbles, cracks or shedding were found, it was qualified for acid and alkali resistance, otherwise it was unqualified.

[0063] The results are shown in Table 1.

[0064] Table 1 Comparison of performance test results of Examples 1-3 and Comparative Examples 1-2

[0065]

[0066] According to the above test results, it can be seen that the photocurable organic quantum dot mixed ink prepared in Examples 1-3 has excellent performance, the printed samples are clear, and the mechanical properties, adhesion, and acid and alkali resistance are all good; while in Comparative Example 1, in which the organic modified carbon quantum dots are replaced with unmodified carbon quantum dots, the compatibility between the components is reduced, and a uniform and stable structure cannot be obtained, and various performances are significantly reduced; in Comparative Example 2 in which the polymerizable photoinitiator is replaced, the synergistic effect between the components is reduced, and a more three-dimensional and tight cross-linked structure cannot be obtained, and the bending resistance is reduced.

[0067] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0068] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A photocurable organic quantum dot mixed ink, characterized in that: The photocurable organic quantum dot mixed ink comprises the following components in parts by weight: in, The organically modified carbon quantum dots are carbon quantum dots with vinylbenzene grafted on the surface.

2. The photocurable organic quantum dot hybrid ink according to claim 1, characterized in that: The method for preparing the organic modified carbon quantum dots comprises the following steps: The carbon quantum dots, vinyl chloride benzene and a catalyst are mixed and heated for reaction to obtain organically modified carbon quantum dots.

3. The photocurable organic quantum dot hybrid ink according to claim 2, characterized in that: The carbon quantum dots are amino carbon quantum dots.

4. The photocurable organic quantum dot hybrid ink according to claim 2, characterized in that: The temperature of the heating reaction is 70-100° C. and the time is 2-10 hours.

5. The photocurable organic quantum dot hybrid ink according to claim 2, characterized in that: The mass ratio of the carbon quantum dots to vinyl chloride benzene is (1-3):

1.

6. The photocurable organic quantum dot hybrid ink according to claim 1, characterized in that: The acrylates include trimethylolpropane triacrylate and 1,6-hexanediol diacrylate.

7. The photocurable organic quantum dot hybrid ink according to claim 1, characterized in that: The pigment is selected from one or more of carbon black, phthalocyanine blue, titanium dioxide, pigment red, and pigment yellow.

8. The photocurable organic quantum dot hybrid ink according to claim 1, characterized in that: The particle size of the filler is 10-100 nm.

9. The photocurable organic quantum dot hybrid ink according to claim 1, characterized in that: The photoinitiator is selected from polymerizable photoinitiators containing carbon-carbon double bonds.

10. The method for preparing the photocurable organic quantum dot mixed ink according to any one of claims 1 to 9, characterized in that: The steps include: Epoxy resin, polyurethane resin, acrylate, isopropyl acrylamide, organic modified carbon quantum dots, cadmium sulfide, cadmium telluride, pigment, filler, photoinitiator and dispersant are mixed and ground to obtain photocurable organic quantum dot mixed ink.

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