UV (ultraviolet) ink with good weather resistance as well as preparation method and application of UV ink

Abstract

The invention belongs to the technical field of printing ink, and discloses UV printing ink with good weather resistance as well as a preparation method and application of the UV printing ink. The UV ink is prepared from the following raw materials: 20 to 50 parts of aliphatic polyurethane acrylate, 40 to 60 parts of epoxy polyester acrylate, 10 to 40 parts of active monomer, 2 to 6 parts of photoinitiator and 10 to 20 parts of modified composite filler, the active monomers comprise 5-15 parts of a (methyl) acrylate monomer containing fluoroalkyl and 5-20 parts of a silicon-containing acrylate monomer; the modified composite filler is zinc oxide coated talcum powder modified by a silane coupling agent. When the UV ink is used for printing a plastic base material, a cured film layer is good in adhesive force and excellent in weather resistance, acid and alkali resistance, wear resistance and flexibility, and pretreatment operations such as corona, medium coating or flame treatment do not need to be carried out on the plastic base material.

Description

Technical Field

[0001] This invention belongs to the field of ink technology, and specifically relates to a UV ink with good weather resistance, its preparation method, and its application. Background Technology

[0002] Ultraviolet (UV) curing refers to a process in which photosensitive materials in a system absorb energy within a certain wavelength range under ultraviolet radiation, are excited, and undergo photochemical reactions, subsequently decomposing to produce active free radicals or cations. This triggers the polymerization, cross-linking, and curing of prepolymers or active monomers within the system, resulting in a process where the liquid-phase system undergoes instantaneous cross-linking and polymerization. The application of UV ink curing on plastic substrates has long been hampered by adhesion issues. This is mainly due to the rapid curing speed of UV inks, which prevents the timely release of internal stress generated by the volume shrinkage of unsaturated structures such as acrylates. Additionally, the surface energy of plastic substrates is typically low, making it difficult for the coating to fully wet the substrate surface, leading to poor adhesion, peeling, and poor weather resistance of the printed layer. Currently, methods such as corona treatment of the substrate surface to increase surface energy, applying a primer, or oxidizing the substrate surface with a strong oxidizing flame to increase surface activity are commonly used. However, these methods not only increase the number of printing steps but also increase time and production costs. Summary of the Invention

[0003] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the present invention provides a UV ink with good weather resistance, its preparation method, and its application. The UV ink of the present invention exhibits excellent adhesion and weather resistance.

[0004] In a first aspect, the present invention provides a UV ink comprising the following raw materials: 20-50 parts of aliphatic polyurethane acrylate, 40-60 parts of epoxy polyester acrylate, 10-40 parts of reactive monomer, 2-6 parts of photoinitiator, and 10-20 parts of modified composite filler.

[0005] The active monomers include 5-15 parts of fluorinated alkyl (meth)acrylate monomers and 5-20 parts of silicone acrylate monomers;

[0006] The modified composite filler is zinc oxide coated with talc powder modified with a silane coupling agent.

[0007] In some embodiments of the present invention, the epoxy polyester acrylate includes at least one of bisphenol A epoxy acrylate, alicyclic epoxy acrylate, and polyurethane modified epoxy acrylate.

[0008] In some embodiments of the present invention, the fluorinated alkyl (meth)acrylate monomer includes at least one of trifluoroethyl (meth)acrylate, hexafluorobutyl (meth)acrylate, dodecafluoroheptyl methacrylate, and tetrafluoropropanol methacrylate.

[0009] In some embodiments of the present invention, the silicone-containing acrylate monomer includes trimethylsilyl acrylate and / or tributyl methacrylate.

[0010] In some embodiments of the present invention, the photoinitiator includes at least one selected from 1-hydroxycyclohexylphenyl ketone, phenyl-(2,4,6-trimethylbenzoyl)phosphine oxide, 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, 2-isopropylthioxanthonone, and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide.

[0011] In some embodiments of the present invention, the silane coupling agent includes at least one of γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltriethoxysilane, γ-(methacryloyloxy)propyltrimethoxysilane, and γ-(2,3-epoxypropoxy)propyltrimethoxysilane.

[0012] In some embodiments of the present invention, the UV ink further includes the following raw materials: 1-5 parts of dispersant, 10-15 parts of pigment and 0-2 parts of additives; the additives include defoamers and / or leveling agents.

[0013] A second aspect of the present invention provides a method for preparing the UV ink described in the first aspect of the present invention, comprising the following steps:

[0014] The raw materials are mixed, stirred, and ground to obtain the UV ink.

[0015] In some embodiments of the present invention, the method for preparing the modified composite filler includes the following steps:

[0016] The pretreated talc powder was dispersed in anhydrous ethanol, and then an alkaline aqueous solution was added to adjust the pH value. Then, an alcoholic solution of zinc salt was added, and after stirring until the reaction was complete, the mixture was filtered and dried to obtain zinc oxide-coated talc powder.

[0017] The zinc oxide-coated talc powder was dispersed in water, modified by adding a silane coupling agent, filtered, and dried to obtain the modified composite filler.

[0018] In some embodiments of the present invention, the alkaline aqueous solution includes at least one of sodium hydroxide aqueous solution, potassium hydroxide aqueous solution and ammonia solution.

[0019] In some embodiments of the present invention, the pH value is adjusted to 10-12.

[0020] In some embodiments of the present invention, the alcoholic solution of the zinc salt includes a zinc salt, an alkanolamine, and anhydrous ethanol; the zinc salt includes at least one of zinc stearate, zinc acetate, and zinc salicylate; and the alkanolamine includes at least one of isobutanolamine, monoethanolamine, diethanolamine, and triethanolamine.

[0021] In some embodiments of the present invention, the mass ratio of the zinc salt, the alkanolamine, and the anhydrous ethanol is (4-8):0.1:(40-50).

[0022] In some embodiments of the present invention, the pretreatment step includes: adding talc powder to an acidic aqueous solution, heating to react, filtering, collecting the filter cake, washing the filter cake until the pH value is neutral, and then drying.

[0023] In some embodiments of the present invention, the acidic aqueous solution includes at least one of sulfuric acid aqueous solution, nitric acid aqueous solution and hydrochloric acid aqueous solution.

[0024] In some embodiments of the present invention, the temperature of the heating reaction is 80-90°C, and the heating reaction time is 2-4 hours.

[0025] In some embodiments of the present invention, the mass ratio of zinc oxide-coated talc to silane coupling agent is 1:(0.2-0.6).

[0026] A third aspect of the present invention provides the application of the UV ink described in the first aspect of the present invention in printing on plastic substrates, metal substrates and glass substrates.

[0027] In some embodiments of the present invention, the plastic substrate includes a PET substrate, a PC substrate, an ABS substrate, or a PMMA substrate.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] (1) Among the raw materials used in the UV ink of this invention, aliphatic polyurethane acrylate does not contain benzene rings and has good weather resistance, flexibility and wear resistance; epoxy polyester acrylate has a fast photocuring speed and performs well in terms of hardness and corrosion resistance after curing, and also has good adhesion; fluorinated alkyl (meth)acrylate monomers contain CF bond energy with high stability and excellent weather resistance, and also have a certain degree of hydrophobicity, which reduces water penetration (indirectly improving weather resistance); silicone acrylate monomers contain Si-O-Si bonds with good stability and excellent weather resistance, and can also improve the surface energy of the resin and improve the adhesion to the plastic substrate; the modified composite filler has the properties of talc, is soft in texture, can improve flexibility and scratch resistance, is chemically inert, and is resistant to acids and alkalis, while zinc oxide has excellent UV absorption performance and antibacterial properties. Zinc oxide coated talc is modified by silane coupling agent, which is conducive to uniform dispersion in the resin. Good dispersion is the basis for obtaining uniform performance and giving full play to the role of each component.

[0030] (2) The present invention uses aliphatic polyurethane acrylate, epoxy polyester acrylate and active monomer as the main materials, and adds modified composite filler to prepare UV ink. When the UV ink is used for printing on plastic substrates, the cured film layer has good adhesion, and at the same time has excellent weather resistance, acid and alkali resistance, wear resistance and flexibility. It does not require pretreatment operations such as corona treatment, coating medium or flame treatment on plastic substrates. Detailed Implementation

[0031] The present invention will be further described in detail below through specific embodiments. Unless otherwise specified, the raw materials, reagents, or apparatus used in the embodiments can be obtained from conventional commercial sources or by existing technical methods. Unless otherwise specified, the experimental or testing methods are conventional methods in the art.

[0032] In the following examples, the aliphatic polyurethane acrylate was purchased from Changxing Chemical, product brand number 6145-100.

[0033] Example 1

[0034] A UV ink comprising the following raw materials in parts by weight: 35 parts aliphatic polyurethane acrylate, 50 parts bisphenol A epoxy acrylate, 10 parts hexafluorobutyl methacrylate, 10 parts trimethylsilyl acrylate, 4 parts 1-hydroxycyclohexylphenyl ketone, 15 parts modified composite filler, 3 parts dispersant 36000, 12 parts matting agent OK520, 0.2 parts defoamer KS-66, and 0.3 parts leveling agent BYK333.

[0035] The preparation method of the modified composite filler in this embodiment includes the following steps:

[0036] S1. Add talc powder to a 10wt% sulfuric acid aqueous solution, heat to 85℃ and react for 3 hours, filter, collect the filter cake, wash the filter cake with water until the pH value is neutral, and then dry to obtain pretreated talc powder.

[0037] S2. Disperse the pretreated talc powder in anhydrous ethanol, then add sodium hydroxide aqueous solution to adjust the pH to 10, and then add an alcohol solution of zinc salt (composed of zinc stearate, isobutanolamine and anhydrous ethanol in a mass ratio of 4:0.1:40). After stirring and reacting completely at room temperature (25±2℃), filter. Wash the filtered solid with deionized water and anhydrous ethanol until neutral, and then dry to obtain zinc oxide coated talc powder.

[0038] S3. Disperse zinc oxide-coated talc powder in water, add γ-aminopropyltriethoxysilane for modification, filter, and dry to obtain modified composite filler; the mass ratio of zinc oxide-coated talc powder to γ-aminopropyltriethoxysilane is 1:0.4.

[0039] The method for preparing UV ink in this embodiment includes the following steps:

[0040] Aliphatic polyurethane acrylate, bisphenol A epoxy acrylate, hexafluorobutyl methacrylate, trimethylsilyl acrylate, 1-hydroxycyclohexylphenyl ketone, modified composite filler, dispersant 36000, matting agent OK520, defoamer KS-66 and leveling agent BYK333 were added to a mixer and stirred for 30 minutes at a stirring rate of 2000 r / min. Then, the mixture was ground for 1 hour until the fineness was less than 20 μm to obtain UV ink.

[0041] Example 2

[0042] A UV ink comprising the following raw materials in parts by weight: 20 parts aliphatic polyurethane acrylate, 40 parts bisphenol A epoxy acrylate, 5 parts hexafluorobutyl methacrylate, 5 parts trimethylsilyl acrylate, 2 parts 1-hydroxycyclohexylphenyl ketone, 10 parts modified composite filler, 1 part dispersant 36000, 10 parts matting agent OK520, 0.2 parts defoamer KS-66, and 0.3 parts leveling agent BYK333.

[0043] The preparation method of the modified composite filler in this embodiment includes the following steps:

[0044] S1. Add talc powder to a 10wt% sulfuric acid aqueous solution, heat to 85℃ and react for 3 hours, filter, collect the filter cake, wash the filter cake with water until the pH value is neutral, and then dry to obtain pretreated talc powder.

[0045] S2. Disperse the pretreated talc powder in anhydrous ethanol, then add sodium hydroxide aqueous solution to adjust the pH to 10, and then add an alcohol solution of zinc salt (composed of zinc acetate, isobutanolamine and anhydrous ethanol in a mass ratio of 8:0.1:50). After stirring and reacting completely at room temperature (25±2℃), filter. Wash the filtered solid with deionized water and anhydrous ethanol until neutral, and then dry to obtain zinc oxide coated talc powder.

[0046] S3. Disperse zinc oxide-coated talc powder in water, add γ-aminopropyltriethoxysilane for modification, filter, and dry to obtain modified composite filler; the mass ratio of zinc oxide-coated talc powder to γ-aminopropyltriethoxysilane is 1:0.4.

[0047] The method for preparing UV ink in this embodiment includes the following steps:

[0048] Aliphatic polyurethane acrylate, bisphenol A epoxy acrylate, hexafluorobutyl methacrylate, trimethylsilyl acrylate, 1-hydroxycyclohexylphenyl ketone, modified composite filler, dispersant 36000, matting agent OK520, defoamer KS-66 and leveling agent BYK333 were added to a mixer and stirred for 30 minutes at a stirring rate of 2000 r / min. Then, the mixture was ground for 1 hour until the fineness was less than 20 μm to obtain UV ink.

[0049] Example 3

[0050] A UV ink comprising the following raw materials in parts by weight: 50 parts aliphatic polyurethane acrylate, 60 parts bisphenol A epoxy acrylate, 15 parts hexafluorobutyl (meth)acrylate, 20 parts trimethylsilyl acrylate, 6 parts 1-hydroxycyclohexylphenyl ketone, 20 parts modified composite filler, 5 parts dispersant 36000, 15 parts matting agent OK520, 0.2 parts defoamer KS-66, and 0.3 parts leveling agent BYK333.

[0051] The preparation method of the modified composite filler in this embodiment includes the following steps:

[0052] S1. Add talc powder to a 10wt% sulfuric acid aqueous solution, heat to 85℃ and react for 3 hours, filter, collect the filter cake, wash the filter cake with water until the pH value is neutral, and then dry to obtain pretreated talc powder.

[0053] S2. Disperse the pretreated talc powder in anhydrous ethanol, then add sodium hydroxide aqueous solution to adjust the pH to 10, and then add an alcohol solution of zinc salt (composed of zinc stearate, isobutanolamine and anhydrous ethanol in a mass ratio of 6:0.1:45). After stirring and reacting completely at room temperature (25±2℃), filter. Wash the filtered solid with deionized water and anhydrous ethanol until neutral, and then dry to obtain zinc oxide coated talc powder.

[0054] S3. Disperse zinc oxide-coated talc powder in water, add γ-aminopropyltriethoxysilane for modification, filter, and dry to obtain modified composite filler; the mass ratio of zinc oxide-coated talc powder to γ-aminopropyltriethoxysilane is 1:0.4.

[0055] The method for preparing UV ink in this embodiment includes the following steps:

[0056] Aliphatic polyurethane acrylate, bisphenol A epoxy acrylate, hexafluorobutyl methacrylate, trimethylsilyl acrylate, 1-hydroxycyclohexylphenyl ketone, modified composite filler, dispersant 36000, matting agent OK520, defoamer KS-66 and leveling agent BYK333 were added to a mixer and stirred for 30 minutes at a stirring rate of 2000 r / min. Then, the mixture was ground for 1 hour until the fineness was less than 20 μm to obtain UV ink.

[0057] Comparative Example 1

[0058] The difference from Example 1 is that bisphenol A epoxy acrylate is missing, while the other raw materials, amounts and preparation methods are the same as in Example 1.

[0059] Comparative Example 2

[0060] The difference from Example 1 is that trimethylsilyl acrylate is missing, while the other raw materials, amounts and preparation methods are the same as in Example 1.

[0061] Comparative Example 3

[0062] The difference from Example 1 is that the preparation process of the modified composite filler is different. In this comparative example, zinc oxide and talc are directly dispersed in water, and then γ-aminopropyltriethoxysilane is added for modification. The other raw materials, dosages and preparation methods are the same as in Example 1.

[0063] Comparative Example 4

[0064] The difference from Example 1 is that the zinc oxide-coated talc powder was not modified with a silane coupling agent, while the other raw materials, dosages, and preparation methods are the same as in Example 1.

[0065] Test case

[0066] This experimental example provides the performance tests and test results of the UV inks prepared in Examples 1-3 and Comparative Examples 1-4. The test methods are as follows, and the test results are shown in Table 1.

[0067] Using PMMA as the printing substrate, the inks prepared in each embodiment and comparative example were printed using a 350-mesh screen and then cured under ultraviolet light. The cured PMMA substrates were used as test samples to evaluate the ink performance. No pretreatment steps such as corona treatment, coating with a medium, or flame treatment were performed on the PMMA substrate before printing the ink.

[0068] Test method for UV ink adhesion: Refer to GB / T 13217.7-2023 for testing.

[0069] Test method for the acid and alkali resistance of UV ink: Immerse the sample to be tested completely in 5wt% HCl (25℃) and 5wt% NaOH (25℃) solutions respectively, and keep the temperature constant for 48h; after taking it out, rinse it with clean water, dry it and test its adhesion. The adhesion test method is the same as above.

[0070] Test method for UV ink weather resistance: Use a QUV (Quick UV) aging chamber, set the program to 12 cycles, each cycle 8 hours, including 4 hours of UV irradiation time (0.63W / m²). 2 After testing (60℃ and 6nm) and 4 hours of moisture exposure time, let it stand at room temperature for 2 hours after the test, observe whether there is any change in the appearance of the ink surface, and test its adhesion. The adhesion test method is the same as above.

[0071] Test method for UV ink hardness: Refer to GB / T 6739-2022 for testing.

[0072] Table 1

[0073] project Adhesion strength / % Acid resistance / % Alkali resistance / % Weather resistance test / % Hardness / H Example 1 100 100 100 100 6 Example 2 100 100 100 100 6 Example 3 100 100 100 100 6 Comparative Example 1 90 82 84 84 4 Comparative Example 2 93 90 88 85 5 Comparative Example 3 95 94 95 84 5 Comparative Example 4 92 92 92 80 4

[0074] As can be seen from the data in Table 1: Comparative Examples 1 and 2 resulted in a decrease in the overall performance of the inks due to changes in the resin system of the inks of this invention; in Comparative Example 3, zinc oxide and talc were simply mixed in a conventional manner without using a zinc oxide-coated talc structure, so some zinc oxide may have been masked by talc and could not fully contact ultraviolet light, which significantly reduced the UV protection efficiency; in Comparative Example 4, the zinc oxide-coated talc was not modified by a silane coupling agent, resulting in poor dispersibility, easy agglomeration, and inability to fully exert its UV protection effect.

[0075] Therefore, it can be seen that the present invention effectively improves the overall performance of UV ink through the combined effect of various raw materials.

[0076] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A UV ink, characterized in that, The UV ink comprises the following raw materials in parts by weight: 20-50 parts of aliphatic polyurethane acrylate, 40-60 parts of epoxy polyester acrylate, 10-40 parts of reactive monomer, 2-6 parts of photoinitiator, and 10-20 parts of modified composite filler. The active monomers include 5-15 parts of fluorinated alkyl (meth)acrylate monomers and 5-20 parts of silicone acrylate monomers; The modified composite filler is zinc oxide coated with talc powder modified with a silane coupling agent.

2. The UV ink according to claim 1, characterized in that, The epoxy polyester acrylate includes at least one of bisphenol A epoxy acrylate, alicyclic epoxy acrylate, and polyurethane modified epoxy acrylate.

3. The UV ink according to claim 1, characterized in that, The fluorinated alkyl (meth)acrylate monomers include at least one of trifluoroethyl (meth)acrylate, hexafluorobutyl (meth)acrylate, dodecafluoroheptyl methacrylate, and tetrafluoropropanol methacrylate.

4. The UV ink according to claim 1, characterized in that, The silicon-containing acrylate monomers include trimethylsilyl acrylate and / or tributylsilane methacrylate.

5. The UV ink according to claim 1, characterized in that, The photoinitiator includes at least one of 1-hydroxycyclohexylphenyl ketone, phenyl-(2,4,6-trimethylbenzoyl)phosphine oxide, 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, 2-isopropylthioxanthrone, and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide.

6. The UV ink according to claim 1, characterized in that, The UV ink also includes the following raw materials: 1-5 parts dispersant, 10-15 parts pigment, and 0-2 parts additives; the additives include defoamers and / or leveling agents.

7. The method for preparing the UV ink according to any one of claims 1-6, characterized in that, Includes the following steps: The raw materials are mixed, stirred, and ground to obtain the UV ink.

8. The preparation method according to claim 7, characterized in that, The preparation method of the modified composite filler includes the following steps: The pretreated talc powder was dispersed in anhydrous ethanol, and then an alkaline aqueous solution was added to adjust the pH value. Then, an alcoholic solution of zinc salt was added, and after stirring until the reaction was complete, the mixture was filtered and dried to obtain zinc oxide-coated talc powder. The zinc oxide-coated talc powder was dispersed in water, modified by adding a silane coupling agent, filtered, and dried to obtain the modified composite filler.

9. The preparation method according to claim 8, characterized in that, The pretreatment steps include: adding talc powder to an acidic aqueous solution, heating to react, filtering, collecting the filter cake, washing the filter cake until the pH value is neutral, and then drying.

10. The application of the UV ink according to any one of claims 1-6 in printing on plastic substrates, metal substrates and glass substrates.