Functional ink combining dual mechanisms of ultraviolet curing and moisture curing as well as preparation method and application of functional ink

Abstract

The invention relates to functional ink combining dual mechanisms of ultraviolet curing and moisture curing as well as a preparation method and application of the functional ink, and belongs to the technical field of ink. The functional ink combining the dual mechanisms of ultraviolet light curing and moisture curing is prepared from the following components in percentage by mass: 40 to 50 percent of light-cured resin, 20 to 25 percent of moisture-cured resin, 3 to 5 percent of composite light initiation system, 0.5 to 1.5 percent of moisture curing catalyst, 5 to 15 percent of functional filler and 2 to 4 percent of additive. Under the condition that the ultraviolet light intensity is 1000mW / cm < 2 >, the surface drying time is 3-5 seconds; the curing depth is 105-120 [mu] m after moisture curing is performed for 24 h in the environment with the humidity being 60-80% and the temperature being 15-25 DEG C, the problem that a single UV curing shadow area is difficult to completely cure or the single moisture curing speed is low is solved, multiple functions such as antibiosis, electric conduction, wear resistance and hydrophobicity are integrated, and the requirements of different application scenes are met.

Description

Technical Field

[0001] The present application relates to the field of ink technology, and in particular to a functional ink that combines ultraviolet light curing and moisture curing mechanisms, as well as a preparation method and application thereof. Background Art

[0002] Traditional inks have numerous deficiencies in terms of curing methods, curing speeds, adhesion, abrasion resistance, and functionality. For example, inks that rely solely on heat curing methods suffer from slow curing speeds and low production efficiency, while inks that rely solely on light curing suffer from insufficient curing depth and poor adhesion to certain substrates.

[0003] Ordinary inks often lack specialized functionality, making them difficult to meet specific requirements such as antibacterial, self-cleaning, and anti-counterfeiting. In the food packaging and printing industry, which places extremely high demands on hygiene, inks with antibacterial properties are required to ensure food safety. In outdoor advertising printing, self-cleaning properties are desirable to maintain the clarity of advertising images.

[0004] UV-curable inks offer the advantages of fast curing speed and low energy consumption, but they suffer from limited curing depth and difficulty in fully curing shadowed areas. While heat-curable inks can achieve uniform curing, they consume high energy, take a long time to cure, and are unsuitable for heat-sensitive substrates. Furthermore, inks using a single curing method can exhibit unstable performance in complex environments (such as high humidity and low temperatures), leading to poor adhesion and insufficient abrasion resistance.

[0005] In the prior art, Chinese patent publication number CN 112029339 A discloses a non-ophthalic UV offset ink, which primarily improves ink performance by compounding a UV-curable resin, polyester acrylate, and epoxy acrylate. However, this ink, which uses UV curing alone, suffers from insufficient curing depth (50 μm) and uncured shadow areas. This addresses only the single issue of UV curing speed or depth, failing to achieve the synergistic effect of "fast surface drying + deep curing." Chinese patent publication number CN106883412B discloses a modified silicone leveling resin and its preparation method. This resin is prepared by reacting a polysiloxane with hydroxyl or epoxy end groups with a compound containing carboxyl groups and double bonds. This resin only improves leveling and does not involve a dual-cure mechanism or functional integration.

[0006] Therefore, the existing technology lacks an ink that achieves synergistic effects of UV curing and moisture curing through a specific molecular structure design (siloxane to isocyanate group molar ratio of 1:1.2-1.5, distribution spacing of 2-5nm), and has multiple functionalities such as conductivity and wear resistance. Summary of the Invention

[0007] In view of this, the present application provides a functional ink that combines the dual mechanisms of ultraviolet light curing and moisture curing, as well as its preparation method and application, and realizes a UV / moisture curing synergistic ink system through a siloxane-isocyanate resin and a composite photoinitiator; the molar ratio of the siloxane group to the isocyanate group of the moisture curing resin is 1:(1.2-1.5), and at this ratio, the moisture curing speed and UV curing are best matched, which can effectively overcome the defects of the above-mentioned prior art.

[0008] The first aspect of the present application provides a functional ink that combines the dual mechanisms of ultraviolet light curing and moisture curing, which includes the following components by mass percentage: 40-50% photocurable resin, 20-25% moisture curable resin, 3-5% composite photoinitiator system, 0.5-1.5% moisture curing catalyst, 5-15% functional filler, and 2-4% additive.

[0009] This specific ratio and spacing optimizes the rate matching between UV curing (3-5 seconds) and moisture curing (24 hours), increasing the curing depth to 120 μm, while the single-curing ink (Comparative Examples 1-2) only reaches 50-80 μm.

[0010] Preferably, the photocurable resin is a modified epoxy acrylate or modified polyurethane acrylate; the modified epoxy acrylate is an epoxy acrylate grafted with an organosiloxane, and the modified polyurethane acrylate is a polyurethane acrylate containing fluorocarbon segments. Specifically, in special circumstances, such as when a large amount of functional fillers is present, the amount of photocurable resin may be appropriately increased.

[0011] Preferably, the moisture-curable resin is a resin containing bifunctional siloxane and isocyanate groups; wherein the molar ratio of siloxane to isocyanate groups is 1:(1.2-1.5), and the distribution spacing between the siloxane and isocyanate groups is 2-5 nm.

[0012] Preferably, the composite photoinitiator system consists of TPO, 1173 and 2-(4-methylbenzoyl)-methyl benzoate, and the 2-(4-methylbenzoyl)-methyl benzoate accounts for 20-30%.

[0013] Specifically, in the composite photoinitiator system, the addition amount of 2-(4-methylbenzoyl)-methyl benzoate is 20-30%, the decomposition product of which is methanol (verified by GC-MS), and moisture curing is not inhibited when the methanol concentration is less than 0.1%.

[0014] Preferably, the moisture curing catalyst is a composite system of an organotin compound and a quaternary ammonium salt catalyst; wherein the organotin compound is dibutyltin dilaurate, the quaternary ammonium salt catalyst is tetrabutylammonium bromide, and the weight ratio of the organotin compound to the quaternary ammonium salt catalyst is (1-2):1.

[0015] Preferably, the functional filler is graphene-wrapped conductive carbon black and / or surface-modified nano-silica; wherein the number of graphene-wrapped conductive carbon black layers is 1-3, the wrapping thickness is 0.5-1 nm, and the surface-modified nano-silica is treated with a silane coupling agent.

[0016] Specifically, the number of wrapping layers of the graphene-wrapped conductive carbon black is 1-3 layers, the thickness is 0.5-1 nm (TEM verification), and the surface grafting rate is 80-90%. The Raman spectrum D peak and G peak intensity ratio (ID / IG) of the graphene-wrapped conductive carbon black is ≤0.2, which proves that the defect rate is low (verified by 2-(4-methylbenzoyl)-methyl benzoate PS).

[0017] Comparing unwrapped carbon black (conductivity 50S / cm) with 1-3 layers of graphene-wrapped carbon black (150S / cm), the latter has significantly better dispersion uniformity in the ink (particle size deviation <5%) than the former (deviation >20%).

[0018] Preferably, the auxiliary agent includes a leveling agent, a defoaming agent, and an adhesion promoter; wherein the adhesion promoter is a silane coupling agent containing amino and epoxy groups.

[0019] A second aspect of the present application further provides a method for preparing the functional ink combining the dual mechanisms of UV curing and moisture curing, comprising the following steps:

[0020] (1) Premixing: Add the light-curing resin, moisture-curing resin and functional filler into a reactor and disperse them at a high speed of 1500-2000 rpm at 85-95°C for 30-60 minutes under the protection of inert gas;

[0021] (2) Post-addition: After the material is cooled to room temperature, add the composite photoinitiator system, moisture curing catalyst and additives, and stir at a low speed of 500-800 rpm for 30-45 minutes;

[0022] (3) Grinding: Grind the mixed materials through a three-roll mill for 3-5 times, control the fineness of the ground ink to ≤5μm, and control the temperature during the grinding stage at 25-30℃;

[0023] (4) Degassing: The ground ink was first degassed at a vacuum of -0.07 MPa for 10 minutes and then degassed at a vacuum of -0.09 MPa for 15 minutes to obtain a functional ink that combines the dual mechanisms of UV curing and moisture curing.

[0024] Preferably, when the moisture-curing resin is a resin containing siloxane and isocyanate bifunctional groups, the preparation process of the resin containing siloxane and isocyanate bifunctional groups is that: a terminal hydroxyl polysiloxane is reacted with a compound containing isocyanate group and double bond under the action of an organic tin catalyst dibutyltin dilaurate at 60-80°C for 2-4 hours, wherein the terminal hydroxyl polysiloxane is a linear polysiloxane or a side-chain polysiloxane, the chemical structural formula of the linear polysiloxane is:

[0025]

[0026] wherein m is any integer in the range of 10-100, and R is a hydroxyl group; the chemical structural formula of the side-chain polysiloxane is:

[0027]

[0028] wherein o and p are both any integer in the range of 0-100, and the sum of o and p is 100, and the chemical structural formula of R2 is:

[0029]

[0030] wherein 2-(4-methylbenzoyl)-benzoic acid methyl ester and y are both any integer in the range of 1-15, and R1 is H.

[0031] The third aspect of the present application also provides the application of the functional ink combining the ultraviolet light curing and moisture curing double mechanisms in the fields of food packaging printing and outdoor advertising printing.

[0032] Compared with the prior art, the present application has the following beneficial effects:

[0033] 1. Double curing mechanism: combining UV curing and moisture curing, UV curing realizes second-level surface drying, and moisture curing realizes deep crosslinking, solving the defects of single curing mode; the present application solves the compatibility problem of double curing through "molecular structure design + compound system optimization", and the technical effect (such as curing depth 120 μm) exceeds that of single curing ink (50-80 μm).

[0034] 2. Special resin design: the moisture-curing resin adopts the special structure of siloxane and isocyanate bifunctional groups, and the moisture crosslinking efficiency is significantly improved through the optimization of intramolecular group distribution, and the curing depth can reach 120 μm.

[0035] 3. Compound photoinitiating system: composed of TPO, 1173 and a new type of photoinitiator 2-(4-methylbenzoyl)-benzoic acid methyl ester, the synergistic effect makes the UV curing speed increase to 3-5 seconds, and the curing depth increases by more than 50%, and the decomposition product of the new type of photoinitiator 2-(4-methylbenzoyl)-benzoic acid methyl ester does not inhibit the moisture curing reaction.

[0036] 4. Composite catalyst system: The organic tin compound is compounded with the quaternary ammonium salt catalyst, which can still maintain a high efficiency moisture curing rate under low temperature (15°C) and high humidity (80%) conditions and fully cure within 24 hours.

[0037] 5. Multifunctional integration: By adding functional fillers and additives, the ink has multiple functions such as antibacterial, conductive, wear-resistant, and hydrophobic.

[0038] 6. Advanced preparation technology: A combination of high-speed dispersion under inert gas protection, three-roller grinding (fineness ≤ 5μm) and vacuum degassing is used to ensure that the nanofillers are evenly dispersed and free of bubble defects.

[0039] 7. Excellent curing performance: when the UV intensity is 1000mW / cm 2 Under the conditions of humidity of 60-80% and temperature of 15-25℃, the surface drying time is 3-5 seconds; after 24 hours of moisture curing, the curing depth is 105-120μm, which solves the problem that the shadow area of ​​single UV curing is difficult to fully cure or the single moisture curing speed is slow.

[0040] 8. Strong environmental adaptability: It can still maintain efficient curing under low temperature and high humidity conditions, overcoming the problem of unstable performance of traditional inks in complex environments.

[0041] 9. Diverse Functionality: It integrates multiple functions, including antibacterial, conductive, wear-resistant, and hydrophobic properties, to meet the needs of diverse application scenarios. For example, the antibacterial rate against Escherichia coli and Staphylococcus aureus exceeds 99%. When the addition amount of graphene-encapsulated conductive carbon black is 4.5-8%, the conductivity can reach 120-150S / cm. When the addition amount exceeds 8%, the conductivity drops to below 90S / cm due to filler agglomeration. The wear resistance can reach 5200-6000 times (750g weight, back and forth friction).

[0042] 10. High adhesion: The adhesion to various substrates such as PET, glass, metal, etc. reaches 5B level.

[0043] 11. Good storage stability: The ink system has good storage stability. When sealed and stored at 2°C and 60°C for 7 days, the change in its refractive index and viscosity is within 10%, and the appearance does not delaminate or become turbid. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the present application or the prior art, the following briefly introduces the drawings required for use in the description of the present application or the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0045] Figure 1 At a 4.5% addition, the carbon black is evenly dispersed in the resin matrix with graphene encapsulating it, without agglomeration (particle size deviation <5%). Low-power microscopy (×10k) reveals that the carbon black particles (black spheres) are completely encapsulated by a single layer of graphene (a thin, transparent layer) with uniform spacing.

[0046] Figure 2 At an 8% addition, high-power microscopy (×50k) shows a small amount of filler contact, but no insulating gaps are formed; at an addition level of >8%, the filler is obviously agglomerated (particle size deviation >20%), forming conductive path defects;

[0047] Figure 3 When the addition amount is 12%, large agglomerates appear (yellow dotted area), which causes the resin matrix to crack. DETAILED DESCRIPTION

[0048] To make the objectives, technical solutions, and advantages of this application more clear, the technical solutions in this application are described clearly and completely below. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0049] Unless otherwise specified, the experimental methods used in the examples of this application are all conventional methods.

[0050] In the following examples and comparative examples, unless otherwise specified, all raw materials can be purchased commercially or prepared by conventional methods.

[0051] It should be noted that the ratio of siloxane to isocyanate is 1:1.3, and the spacing is 3 nm.

[0052] Example 1: Dual-cure functional conductive ink

[0053] Formula composition (by weight percentage)

[0054] Modified epoxy acrylate (organic silicone grafted modified): 45%

[0055] Resins containing siloxane and isocyanate dual functional groups: 25%

[0056] Composite photoinitiator system (TPO 2.5% + 11731.5% + 2-(4-methylbenzoyl)-methyl benzoate 1%, total 5%, new type accounts for 20%): 5%

[0057] Organic tin compound and quaternary ammonium salt catalyst complex system (dibutyltin dilaurate: tetrabutylammonium bromide weight ratio is 1:1): 1%

[0058] 1 layer of graphene wrapped carbon black: 8% (graphene wrapped conductive carbon black is 1 layer wrapped, the wrapping thickness is 0.5-1nm)

[0059] Additives (leveling agent, defoamer, adhesion promoter): 3%

[0060] Antimicrobial: 0.5%.

[0061] Preparation method

[0062] Add modified epoxy acrylate, resin containing siloxane and isocyanate bifunctional groups, and conductive carbon black coated with graphene on the surface into a reaction kettle and disperse them at a high speed of 1800 rpm at 90°C for 45 minutes under the protection of inert gas;

[0063] After the material is cooled to room temperature, the composite photoinitiator system, the organic tin compound and the quaternary ammonium salt catalyst complex system and the additives are added, and the mixture is stirred at a low speed of 600 rpm for 35 minutes;

[0064] Grind the mixed material through a three-roll mill 4 times to a fineness of ≤5μm. The temperature during the grinding stage is controlled at 25-30℃.

[0065] The ground ink was first degassed at a vacuum degree of -0.07 MPa for 10 minutes and then degassed at a vacuum degree of -0.09 MPa for 15 minutes to obtain a dual-curing functional conductive ink.

[0066] Performance Testing

[0067] Curing performance: When the UV intensity is 1000mW / cm 2 Under the conditions of humidity of 60% and temperature of 25℃, the surface drying time is 4 seconds; after 24 hours of moisture curing, the curing depth is 120μm.

[0068] Conductivity: The conductivity is 150S / cm.

[0069] Adhesion (PET substrate): 5B level.

[0070] Abrasion resistance (750g weight, back and forth friction): 5500 times.

[0071] Depend on Figures 1-3It can be seen that at a 4.5% addition amount: graphene-wrapped carbon black (white arrows indicate that single-layer graphene completely wraps carbon black particles) is uniformly dispersed in the resin matrix without agglomeration (particle size deviation <5%). At a 4.5% addition amount, low-magnification microscopy (×10k) shows that single-layer graphene (transparent thin layer) completely wraps carbon black particles (black spheres) with uniform spacing. At an 8% addition amount: the filler still remains dispersed, but slight aggregation occurs locally (particle size deviation 8%). At an 8% addition amount, high-magnification microscopy (×50k) shows that a small amount of filler contacts, but no insulating gaps are formed. At a >8% addition amount: the filler is obviously agglomerated (particle size deviation >20%), forming a conductive path defect. At a 12% addition amount, large-area agglomerates appear (the yellow dotted area indicates resin cracking caused by filler agglomeration), causing cracking of the resin matrix.

[0072] The particle size distribution statistics are shown in Table 1.

[0073] Table 1

[0074] Addition amount D50 (pm) Particle size deviation Conductivity (S / cm) 4.5％ 0.12 4.8％ 150 8％ 0.15 7.9％ 140 12％ 0.35 22％ 90

[0075] From the data in Table 1, it can be seen that 4.5-8% is the optimal range, taking into account both conductivity (150 S / cm) and dispersion stability.

[0076] Example 2: Dual-curing functional wear-resistant ink

[0077] Formula composition (by weight percentage)

[0078] Modified polyurethane acrylate (containing fluorocarbon segments): 48.5%

[0079] Resins containing siloxane and isocyanate dual functional groups: 25%

[0080] Composite photoinitiator system (TPO:1173: new photoinitiator 2-(4-methylbenzoyl)-methyl benzoate = 3:1:1): 5%

[0081] Organic tin compound and quaternary ammonium salt catalyst complex system (weight ratio of dibutyltin dilaurate: tetrabutylammonium bromide is 1:2): 1.5%

[0082] Nano-silica treated with silane coupling agent: 12%

[0083] Additives (leveling agent, defoamer, adhesion promoter): 3.5%

[0084] Antimicrobial agent 0.5%.

[0085] Preparation method

[0086] Add modified polyurethane acrylate, resin containing siloxane and isocyanate bifunctional groups and nano-silica treated with surface silane coupling agent into a reaction kettle and disperse them at a high speed of 1600 rpm at 85°C for 50 minutes under the protection of inert gas;

[0087] After the material is cooled to room temperature, the composite photoinitiator system, the organic tin compound and the quaternary ammonium salt catalyst complex system and the auxiliary agent are added, and the mixture is stirred at a low speed of 700 rpm for 40 minutes;

[0088] Grind the mixed material three times through a three-roll mill to a fineness of ≤5μm. The temperature during the grinding stage is controlled at 25-30°C.

[0089] The ground ink was first degassed at a vacuum degree of -0.07 MPa for 10 minutes and then degassed at a vacuum degree of -0.09 MPa for 15 minutes to obtain a dual-curing functional wear-resistant ink.

[0090] Performance Testing

[0091] Curing performance: When the UV intensity is 1000mW / cm 2 Under the conditions of humidity of 70% and temperature of 20℃, the surface drying time is 3.5 seconds; after 24 hours of moisture curing, the curing depth is 110μm.

[0092] Adhesion (glass substrate): 5B level.

[0093] Abrasion resistance (750g weight, back and forth friction): 6000 times.

[0094] Example 3: Dual-curing functional conductive wear-resistant antibacterial ink

[0095] Formula composition (by weight percentage)

[0096] Modified epoxy acrylate (organic silicone grafted modified): 50%

[0097] Resins containing siloxane and isocyanate dual functional groups: 22%

[0098] Composite photoinitiator system (TPO:1173:new photoinitiator 2-(4-methylbenzoyl)-methyl benzoate=1:3:1): 5%

[0099] Organic tin compound and quaternary ammonium salt catalyst complex system (weight ratio of dibutyltin dilaurate: tetrabutylammonium bromide is 2:1): 0.8%

[0100] Conductive carbon black coated with graphene: 7%

[0101] Nano-silica treated with a surface silane coupling agent: 5% (i.e., the functional filler is a combination of graphene-wrapped conductive carbon black (7%) and surface-modified nano-silica (5%))

[0102] Additives (leveling agent, defoaming agent, adhesion promoter, antibacterial agent): 2.2%.

[0103] Preparation method

[0104] Modified epoxy acrylate, resin containing siloxane and isocyanate bifunctional groups, conductive carbon black coated with graphene on the surface, and nano-silica treated with a silane coupling agent on the surface were added to a reaction kettle and dispersed at a high speed of 2000 rpm at 95°C for 30 minutes under the protection of inert gas.

[0105] After the material is cooled to room temperature, the composite photoinitiator system, the organic tin compound and the quaternary ammonium salt catalyst complex system, the auxiliary agent and the antibacterial agent are added, and the mixture is stirred at a low speed of 500 rpm for 45 minutes;

[0106] Grind the mixed material through a three-roll mill for 5 times, controlling the fineness to ≤5μm, and the temperature during the grinding stage to be controlled at 25-30℃;

[0107] The ground ink was first degassed at a vacuum degree of -0.07 MPa for 10 minutes and then degassed at a vacuum degree of -0.09 MPa for 15 minutes to obtain a dual-curing functional conductive wear-resistant and antibacterial ink.

[0108] Performance Testing

[0109] Curing performance: When the UV intensity is 1000mW / cm 2 Under the conditions of humidity of 80% and temperature of 15℃, the surface drying time is 5 seconds; after 24 hours of moisture curing, the curing depth is 110μm.

[0110] Conductivity: The conductivity is 120S / cm.

[0111] Adhesion (metal substrate): 5B level.

[0112] Abrasion resistance (750g weight, back and forth friction): 5200 times.

[0113] Antibacterial properties: The antibacterial rates against Escherichia coli and Staphylococcus aureus are both over 99%.

[0114] Example 4

[0115] This embodiment can refer to Example 1, except that three layers of graphene wrap the carbon black.

[0116] Comparative Example 1: Single UV curing ink

[0117] Formula composition (by weight percentage)

[0118] Unmodified epoxy acrylate: 60%

[0119] Photoinitiator TPO: 5%

[0120] Functional filler (unwrapped carbon black): 10%

[0121] Additives (leveling agent, defoaming agent): 5%

[0122] Solvent: 20%.

[0123] Preparation method

[0124] The components were mixed evenly and ground with a three-roll mill to a fineness of ≤10 μm.

[0125] Performance Testing

[0126] Curing performance: When the UV intensity is 1000mW / cm 2 Under the conditions of , the surface drying time is 8 seconds and the curing depth is 50μm.

[0127] Adhesion (PET substrate): 3B level.

[0128] Abrasion resistance (750g weight, back and forth friction): 2500 times.

[0129] In Comparative Example 1, the "unmodified epoxy acrylate" of the single UV curing ink accounts for 60%, but its performance is far worse than the 45% modified resin in Example 1. The reason why the high proportion of resin has worse performance is that the unmodified resin has a low degree of crosslinking and requires solvent dilution, resulting in a decrease in performance.

[0130] Comparison of Comparative Example 1 with Example 1: The high-ratio unmodified resin exhibits poorer performance. This is due to the following: DSC testing demonstrates that the glass transition temperature (Tg) of the modified epoxy acrylate is 20°C higher than that of the unmodified resin, explaining the difference in crosslink density. The modified resin exhibits a microscopic phase separation structure (particle size distribution <50 nm), while the unmodified resin exhibits aggregates >200 nm.

[0131] The molecular design of the siloxane-isocyanate bifunctional resin in this application (molar ratio 1:1.2-1.5, spacing 2-5nm) and the synergistic effect of the UV curing resin are cited from Example 1:

[0132] Curing depth 120μm (only 50μm in reference 1);

[0133] The surface drying time is 3-5 seconds (reference document 1 takes 8 seconds).

[0134] In situ FTIR spectroscopy demonstrated that the residual double bond rate after UV curing was <5%, while the -NCO group reaction rate during the moisture curing stage was >95%, indicating that there was no mutual inhibition between the dual curing steps.

[0135] Comparative Example 2: Single Moisture Curing Ink

[0136] Formula composition (by weight percentage)

[0137] Resin containing isocyanate groups: 70%

[0138] Moisture curing catalyst (organic tin compound): 1%

[0139] Functional filler (unmodified nano-silica): 15%

[0140] Additives (leveling agent, defoaming agent): 4%

[0141] Solvent: 10%.

[0142] Preparation method

[0143] The components were mixed evenly and ground with a three-roll mill to a fineness of ≤10 μm.

[0144] Performance Testing

[0145] Curing performance: Under the environment of 60% humidity and 25℃, it takes 72 hours to fully cure, and the curing depth is 80μm.

[0146] Adhesion (PET substrate): 4B level.

[0147] Abrasion resistance (750g weight, back and forth friction): 3000 times.

[0148] Comparative Example 3

[0149] This comparative example can refer to Example 1, except that the photoinitiator system contains TPO (2%) + 1173 (2%), and the other components are the same as those in Example 1.

[0150] Comparative Example 4

[0151] This comparative example can refer to Example 1, except that 5 layers of graphene wrap the carbon black.

[0152] In Comparative Example 4, the conductivity of the carbon black wrapped with 5 layers of graphene (130 S / cm) is lower than that of the carbon black wrapped with 3 layers (150 S / cm). The reason is that the 5-layer graphene wrapping is too thick, which leads to a decrease in dispersion and affects the conductive path of the carbon black.

[0153] Comparative test:

[0154] By comparing the performance differences of the two photoinitiator systems of TPO+1173 in Example 3 and TPO+1173+2-(4-methylbenzoyl)-methyl benzoate in Example 1, the effects of the new photoinitiator 2-(4-methylbenzoyl)-methyl benzoate in the following aspects are demonstrated:

[0155] (1) Improve UV curing speed (shorten surface drying time);

[0156] (2) Increase the curing depth (solve the problem of insufficient curing in shadow areas);

[0157] (3) Avoid inhibition of moisture curing by decomposition products.

[0158] The comparative analysis is shown in Table 2-11:

[0159] Table 2 Comparison of existing technologies

[0160]

[0161] Difference and innovation:

[0162] 1. Solidification mechanism: solve the solidification problem of shadow area;

[0163] 2. Photoinitiator system: improves curing speed and depth without inhibiting side effects;

[0164] 3. Functional filler: conductivity increased by 200%, dispersibility optimized;

[0165] 4. Resin structure: Curing depth increased to 120μm.

[0166] Table 3 Test items and methods

[0167]

[0168]

[0169] Table 4 Comparison of curing speed

[0170]

[0171] Table 5 Comparison of curing depth

[0172]

[0173] Table 6 Moisture Cure Compatibility

[0174]

[0175] Synergistic effect: TPO (long-wave absorption) and 1173 (short-wave absorption) cover the entire spectrum, and 2-(4-methylbenzoyl)-methyl benzoate (medium-wave absorption) improves light energy utilization.

[0176] Deep curing mechanism: 2-(4-methylbenzoyl)-methyl benzoate has a long excited state life span and can penetrate the surface to initiate deep resin polymerization

[0177] Table 7 Table 8

[0178] Filler type Conductivity (S / cm) Wear resistance (times) Dispersion deviation Unwrapped carbon black 50 2500 / 1 layer graphene-wrapped carbon black 150 5000 <5％ 3 layer graphene-wrapped carbon black 150 5500 <8％ 5 layer graphene-wrapped carbon black 130 4800 >15％

[0179] By limiting microscopic parameters such as group spacing, concentration of photoinitiator decomposition products, and number of graphene wrapping layers, unavoidable technical barriers are formed.

[0180] Table 9

[0181]

[0182] Table 10 shows that the number of graphene layers (1-3) inhibits carbon black aggregation through π-π interactions. However, excessive filler (>8%) can overcome the resin's wettability (contact angle >90°), leading to dispersion failure. Methanol is the decomposition product (verified by GC-MS), and methanol concentrations are <0.1%, indicating no inhibitory effect on moisture cure.

[0183] Table 10

[0184] Parameter This application (1-3 layers) Comparative example (5 layers) Unwrapped carbon black Conductivity (S / cm) 150 130 50 Wear resistance (times) 5500 4800 2500

[0185] Preparation process innovation: High-speed dispersion (1500-2000rpm) under inert gas protection can prevent graphene oxidation (XPS verification of oxygen content <5at%).

[0186] Table 11

[0187]

[0188] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A functional ink combining UV curing and moisture curing mechanisms, characterized in that: The composition includes the following components by mass percentage: 40-50% of light-curing resin, 20-25% of moisture-curing resin, 3-5% of composite light-initiating system, 0.5-1.5% of moisture-curing catalyst, 5-15% of functional filler and 2-4% of auxiliary agent.

2. The functional ink combining dual mechanisms of UV curing and moisture curing according to claim 1, characterized in that: The photocurable resin is epoxy acrylate grafted with organosiloxane or polyurethane acrylate containing fluorocarbon segments; wherein the modified epoxy acrylate is epoxy acrylate grafted with organosiloxane, and the modified polyurethane acrylate is polyurethane acrylate containing fluorocarbon segments.

3. The functional ink combining dual mechanisms of UV curing and moisture curing according to claim 1, characterized in that: The moisture-curable resin is a resin containing bifunctional siloxane and isocyanate groups; wherein the molar ratio of siloxane (derived from terminal hydroxyl polysiloxane) to isocyanate group (aromatic or aliphatic) is 1:(1.2-1.5), and the distribution spacing of the siloxane and isocyanate groups is 2-5 nm.

4. The functional ink combining dual mechanisms of UV curing and moisture curing according to claim 1, characterized in that: The composite photoinitiator system consists of TPO, 1173 and 2-(4-methylbenzoyl)-methyl benzoate, and the 2-(4-methylbenzoyl)-methyl benzoate accounts for 20-30%.

5. The functional ink combining dual mechanisms of UV curing and moisture curing according to claim 1, characterized in that: The moisture curing catalyst is a composite system of an organic tin compound and a quaternary ammonium salt catalyst; wherein the organic tin compound is dibutyltin dilaurate, the quaternary ammonium salt catalyst is tetrabutylammonium bromide, and the weight ratio of the organic tin compound to the quaternary ammonium salt catalyst is (1-2):

1.

6. The functional ink combining dual mechanisms of UV curing and moisture curing according to claim 1, characterized in that: The functional filler is graphene-wrapped conductive carbon black and / or surface-modified nano-silicon dioxide; wherein the number of graphene-wrapped conductive carbon black layers is 1-3, and the wrapping thickness is 0.5-1 nm; the surface-modified nano-silicon dioxide is treated with a silane coupling agent, and has a particle size of 10-50 nm and a specific surface area of ​​100-200 m 2 / g.

7. The functional ink combining dual mechanisms of UV curing and moisture curing according to claim 1, characterized in that: The auxiliary agents include a leveling agent, a defoaming agent, and an adhesion promoter; wherein the adhesion promoter is a silane coupling agent containing amino and epoxy groups.

8. A method for preparing a functional ink combining dual mechanisms of UV curing and moisture curing according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) Premixing: Add the light-curing resin, moisture-curing resin and functional filler into a reactor and disperse them at a high speed of 1500-2000 rpm at 85-95°C for 30-60 minutes under the protection of inert gas; (2) Post-addition: After the material is cooled to room temperature, add the composite photoinitiator system, moisture curing catalyst and additives, and stir at a low speed of 500-800 rpm for 30-45 minutes; (3) Grinding: Grind the mixed materials through a three-roll mill for 3-5 times, control the fineness of the ground ink to ≤5μm, and control the temperature during the grinding stage at 25-30℃; (4) Degassing: The ground ink was first degassed at a vacuum of -0.07 MPa for 10 minutes and then degassed at a vacuum of -0.09 MPa for 15 minutes to obtain a functional ink that combines the dual mechanisms of UV curing and moisture curing.

9. The method for preparing a functional ink combining dual mechanisms of UV curing and moisture curing according to claim 8, characterized in that: When the moisture-curable resin is a resin containing a bifunctional group of siloxane and isocyanate, the preparation process of the resin containing a bifunctional group of siloxane and isocyanate is as follows: a terminal hydroxyl polysiloxane and a compound containing an isocyanate group and a double bond are reacted at 60-80° C. for 2-4 hours under the action of an organic tin catalyst, dibutyltin dilaurate, wherein the terminal hydroxyl polysiloxane is a linear polysiloxane or a side chain polysiloxane, and the chemical structure of the linear polysiloxane is: Wherein, m is any integer in the range of 10-100, R is a hydroxyl group; the chemical structure of the side chain polysiloxane is: Wherein, o and p are any integers in the range of 0-100, and the sum of o and p is 100, and the chemical structure of R2 is: Wherein, 2-(4-methylbenzoyl)-methyl benzoate and y are any integers in the range of 1-15, and R1 is H.

10. Use of the functional ink combining the dual mechanisms of UV curing and moisture curing according to any one of claims 1 to 7 in the fields of food packaging printing and outdoor advertising printing.

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