Multi-substrate universal uv curable ink and method of making same

Abstract

This invention relates to the field of ink printing, specifically providing a multi-substrate universal UV-curable ink and its preparation method. By weight, the UV-curable ink comprises the following raw materials: 40-60 parts of oligomer, 30-50 parts of compound monomer, 2-10 parts of acylphosphoxy photoinitiator, 2-4 parts of pigment, and 2-5 parts of additives. This UV-curable ink, through adjustment of the functional groups of the photoinitiator, oligomer, and monomer, provides similar printing effects on various substrates such as metal, plastic, and glass, and significantly improves the adhesion strength of the ink on different substrates.

Description

Technical Field

[0001] This invention belongs to the field of printing, specifically relating to a multi-substrate universal UV curable ink and its preparation method. Background Technology

[0002] Compared to traditional solvent-based inks, UV inks have been widely adopted due to their faster curing speed and lower energy consumption. However, they are less effective at bonding and adhering to substrates such as metals, plastics, and glass. For example, the high density of metal substrates hinders ink penetration and swelling, making it difficult to form mechanical anchoring. Plastic and glass substrates, due to their low surface tension, struggle to form weak bonds such as van der Waals forces with the ink, hindering ink spreading. Furthermore, plastics and glass substrates are susceptible to static electricity, making them unsuitable for high-speed (100 m / min or higher) ink printing.

[0003] Therefore, there is an urgent need in the market for a UV ink that is suitable for a variety of substrates. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, this invention obtains a UV-curable ink that has similar printing effects and adhesion strength on various substrates such as metal, plastic, and glass by adjusting the group structure of photoinitiators, oligomers, and monomers.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] The first aspect of this invention provides a multi-substrate universal UV-curable ink, comprising, by weight, the following raw materials: 40-60 parts oligomer, 30-50 parts compound monomer, 2-10 parts acylphosphoxy photoinitiator, 2-4 parts pigment, and 2-5 parts additives; wherein the additives include dispersants and defoamers; and the acylphosphoxy photoinitiator has an absorption wavelength of 300-400 nm.

[0007] In some embodiments, the pigment is any one of the yellow, blue, orange, and purple family.

[0008] Pigments can absorb, reflect, and scatter ultraviolet light, causing changes in the intensity of ultraviolet light irradiating the film. Photoinitiators can only transition to an excited state and initiate polymerization after absorbing sufficient energy. Therefore, pigments can affect the efficiency of photoinitiators, thereby affecting the curing speed of inks.

[0009] The photoinitiator prepared in this invention has a strong absorption band that is the weak absorption band of the pigment. Specifically, the yellow pigment has a strong absorption band of 310nm-350nm, the orange pigment has a strong absorption band of 330nm-360nm, the purple pigment has a strong absorption band of 300nm-350nm, and the blue pigment has little difference in different bands. Since most of these bands are located in the UVA region, the photoinitiator with strong long-wavelength absorption prepared in this invention will have a better initiation effect on inks containing these pigments.

[0010] In some embodiments, the preparation steps of the acylphosphoxy photoinitiator are as follows:

[0011] S1. At room temperature, 2,2'-dithiosalicylic acid, phosphorus pentoxide and concentrated sulfuric acid are stirred at 1-5℃ for 5-30 min. Then indole is added and stirred under nitrogen for 50-60 min. Then the temperature is raised to 70-90℃ and stirred for 4-6 h. After stirring, it is dropped into boiling water and stirred for 4-8 min. After cooling, filtering, washing and recrystallizing, reactant 1 is obtained.

[0012] S2. At room temperature, dissolve NaH in DMF, add reactant 1 obtained in step S1, stir at 1-3℃ for 30-40 min, add allyl bromide, stir at 20-30℃ for 2-4 h, quench the reaction with saturated ammonium chloride solution, extract, wash, dry with anhydrous sodium sulfate, filter, distill under reduced pressure, recrystallize to obtain reactant 2.

[0013] S3. Dissolve reactant 2 in 1,2-dichloroethane, cool to 1-3℃, add DMF and POCl3, stir for 5-15 min, heat to 80-90℃, stir for 20-28 h, quench the reaction with 10wt% sodium hydroxide solution, extract, wash, dry with anhydrous sodium sulfate, filter, distill under reduced pressure, and recrystallize to obtain the acylphosphooxy photoinitiator.

[0014] In some embodiments, the mass ratio of 2,2'-dithiosalicylic acid to indole in step S1 is 1:(2-3).

[0015] In some embodiments, the mass ratio of reactant 1 to allyl bromide in step S2 is 1:(1.16-1.32).

[0016] In some embodiments, the mass ratio of reactant 2 to POCl3 in step S3 is 1:(0.02-0.04).

[0017] The photoinitiator matrix prepared by this invention is acylphosphide oxide. Firstly, it can help dissolve oligomers and monomers, achieving good photocuring effect. Secondly, by introducing an indole structure, the degree of molecular conjugation is increased, making its absorption wavelength more compatible with LED light sources. Thirdly, because acylphosphide oxide has a small molecular weight and is cured by free radical initiation without participating in polymerization reactions, the photocured product is prone to migrating toxic substances, which may pose a threat to the environment and human health. This invention improves the compatibility between the photoinitiator and oligomers in the ink by introducing an unsaturated damascene structure, thereby reducing its migration rate.

[0018] In some embodiments, the preparation steps of the oligomer are as follows:

[0019] Hydroxyl-terminated polybutadiene, IPDI, and ethyl acetate were stirred until completely dissolved. Stannous octoate was added, and the mixture was stirred at 80-100°C for 1-2 hours. Polypropylene glycol was added and stirred for 2-4 hours. Dimethylolpropionic acid, 1,4-butanediol, and acetone were added and stirred at 70-90°C for 1-2 hours. Stannous octoate was then added and stirred for 3-5 hours. After cooling to room temperature, TEA was added for emulsification, followed by rotary evaporation to obtain the oligomer.

[0020] In ink formulations, oligomers constitute the largest proportion, forming the basic framework of the ink and determining properties such as adhesion, hardness, and heat resistance. From the perspective of ink adhesion, the oligomers provided by this invention have low surface tension, making the ink surface tension lower than that of the substrate, thereby improving adhesion. Simultaneously, the oligomers possess low functionality, reducing volume shrinkage and decreasing internal stress, resulting in better adhesion. Furthermore, the oligomers also have a low glass transition temperature, indicating a flexible main chain that helps release internal stress and prevents warping or deformation of the ink layer after curing due to excessive internal stress, further enhancing material adhesion.

[0021] This invention introduces hydroxyl-terminated polybutadiene containing double bonds into the oligomer backbone, which increases the crosslinking points during photocuring and improves the surface curing effect of the ink. Moreover, the non-polar hydroxyl-terminated polybutadiene improves the adhesion of the ink to low-polar substrates, possibly because it reduces the content of polar groups on the substrate surface, thereby reducing the surface energy and improving adhesion.

[0022] In addition, the applicant also discovered that the oligomer has certain antistatic properties. The possible reason is that some of the chains of the hydrophilic oligomer form a core-shell structure in the ink, and the accumulated static charge can be released through this structure, effectively reducing the generation of static electricity.

[0023] In some embodiments, the compound monomers comprise isoacrylate and tripropylene glycol diacrylate.

[0024] In some embodiments, the mass ratio of the isoacrylate to the tripropylene glycol diacrylate is 1:(0.6-0.8).

[0025] This invention adjusts the viscosity of oligomers by adding monomers and improves the toughness of ink by compounding monomers. When facing certain thinner substrates, it effectively avoids problems such as ink layer peeling and cracking. At the same time, the compounded monomers bring lower surface tension, enhance the ink's wetting ability on various substrates, obtain stronger interlayer forces, and facilitate ink spreading.

[0026] The second aspect of the present invention provides a method for preparing a multi-substrate universal UV-curable ink, comprising the following steps: mixing oligomers, compound monomers, acylphosphophosphorus photoinitiators, pigments and additives uniformly to obtain the multi-substrate universal UV-curable ink.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. This invention provides a UV-curable ink that exhibits similar printing effects and adhesion strength on various substrates such as metal, plastic, and glass. By adjusting the group structure of the photoinitiator, the absorption band and migration rate of the photoinitiator are controlled, enabling the UV-curable ink to have a better initiation effect on inks containing yellow, blue, orange, and purple pigments, and improving the safety of the ink.

[0029] 2. The oligomer provided by this invention improves the surface curing effect of ink by increasing the crosslinking points during photocuring; and also improves the adhesion of ink on low polarity substrates by reducing the surface energy of the substrate; in addition, the oligomer also has certain antistatic properties, making it suitable for high-speed printing on substrates such as plastics and glass.

[0030] This invention adjusts the viscosity of oligomers by adding monomers and improves the toughness of ink by compounding monomers, effectively avoiding problems such as ink layer peeling and cracking on thin substrates; at the same time, the compounded monomers bring lower surface tension, enhance the ink's wetting ability on various substrates, obtain stronger interlayer forces, and facilitate ink spreading. Detailed Implementation

[0031] The present invention will be described below with reference to specific embodiments. It should be noted that the following embodiments and comparative examples are examples of the present invention and are used only to illustrate the invention, not to limit it. Other combinations and various modifications within the scope of the present invention can be made without departing from the spirit or scope of the invention.

[0032] It should be noted that the solvents used in the following preparation examples and embodiments, such as "DMF", "1,2-dichloroethane", "ethyl acetate", "acetone", etc., are selected in accordance with the routine operation of those skilled in the art, and should be selected according to actual operation.

[0033] It should be noted that the post-processing steps such as "extraction", "washing", "recrystallization" and "reduced pressure distillation" appearing in the following preparation examples and embodiments are routine operations for those skilled in the art, and should be selected according to actual operations.

[0034] To facilitate implementation of this invention by those skilled in the art, some of the raw materials and manufacturers of the embodiments are described below:

[0035] Hydroxyl-terminated polybutadiene was purchased from Zibo Qilong Chemical Co., Ltd., Mn=3150; polypropylene glycol was purchased from Shaoxing Yihong Chemical Co., Ltd., Mn=1000; dispersant BYK-333 and defoamer BY were both purchased from Shanghai Kaiyin Chemical Co., Ltd.

[0036] Preparation Example 1

[0037] The preparation steps of acylphosphoxy photoinitiator-A are as follows:

[0038] S1. At room temperature, 224 g of 2,2'-dithiosalicylic acid, 150 g of phosphorus pentoxide, and 600 mL of 40 wt% concentrated sulfuric acid were stirred at 3 °C for 30 min. Then, 514 g of indole was added, and the mixture was stirred under nitrogen for 60 min. Then, the temperature was raised to 80 °C and stirred for 5 h. After stirring, the mixture was dropped into boiling water and stirred for 6 min. The mixture was cooled, filtered, washed, and recrystallized to obtain reactant 1.

[0039] S2. At room temperature, 189g of 60wt% NaH was dissolved in DMF, and 520g of reactant 1 obtained in step S1 was added. The mixture was stirred at 2℃ for 40min, and 650g of allyl bromide was added. The mixture was stirred at 20℃ for 4h, and the reaction was quenched with saturated ammonium chloride solution. The mixture was then extracted, washed, dried with anhydrous sodium sulfate, filtered, distilled under reduced pressure, and recrystallized to obtain reactant 2.

[0040] S3. Dissolve 350g of reactant 2 in 1,2-dichloroethane, cool to 1℃, add DMF and 10.5g of POCl3, stir for 10min, heat to 85℃, stir for 24h, quench the reaction with 10wt% sodium hydroxide solution, extract, wash, dry with anhydrous sodium sulfate, filter, distill under reduced pressure, and recrystallize to obtain acylphosphoxy photoinitiator-A.

[0041] Preparation Example 2

[0042] The preparation steps of acylphosphoxy photoinitiator-B are as follows:

[0043] The difference between this preparation example and preparation example 1 is that the amount of indole used in step S1 is 403g.

[0044] Preparation Example 3

[0045] The preparation steps of acylphosphoxy photoinitiator-C are as follows:

[0046] The difference between this preparation example and preparation example 1 is that the amount of allyl bromide used in step S2 is 582g.

[0047] Preparation Example 4

[0048] The preparation steps of acylphosphoxy photoinitiator-D are as follows:

[0049] The difference between this preparation example and preparation example 1 is that the amount of allyl bromide used in step S2 is 702g.

[0050] Preparation Example 5

[0051] The preparation steps for oligomer-A are as follows:

[0052] 0.4 mol of hydroxyl-terminated polybutadiene, 10.5 mol of IPDI and ethyl acetate were stirred until completely dissolved. 0.3 mol of stannous octoate was added and stirred at 90 °C for 2 h. 1 mol of polypropylene glycol was added and stirred for 3 h. 0.6 mol of dimethylolpropionic acid, 2 mol of 1,4-butanediol and acetone were added and stirred at 80 °C for 2 h. 0.1 mol of stannous octoate was added and stirred for 3-5 h. After cooling to room temperature, 20 mol of TEA was added for emulsification. The mixture was then rotary evaporated to obtain oligomer-A.

[0053] Preparation Example 6

[0054] The preparation steps of oligomer-B are as follows:

[0055] 10.5 mol IPDI and ethyl acetate were stirred until completely dissolved. 0.3 mol stannous octoate was added and stirred at 90 °C for 2 h. 1 mol polypropylene glycol was added and stirred for 3 h. 1 mol dimethylolpropionic acid, 2 mol 1,4-butanediol and acetone were added and stirred at 80 °C for 2 h. 0.1 mol stannous octoate was then added and stirred for 3-5 h. After cooling to room temperature, 20 mol TEA was added for emulsification. The mixture was then rotary evaporated to obtain oligomer-B.

[0056] Example 1

[0057] A multi-substrate universal UV curable ink, by weight, comprises the following raw materials: 50 parts oligomer-A, 23.5 parts acrylate isoacrylate, 16.5 parts tripropylene glycol diacrylate, 6 parts acylphosphoxy photoinitiator-A, 3 parts pigment yellow 111, 2 parts BYK-333 and 2 parts defoamer BY.

[0058] The preparation method of the multi-substrate universal UV curable ink in this embodiment includes the following steps: mixing oligomer-A, isoacrylate, tripropylene glycol diacrylate, acylphosphoxy photoinitiator-A, pigment yellow 111, BYK-333 and defoamer BY evenly to obtain the multi-substrate universal UV curable ink.

[0059] Example 2

[0060] A multi-substrate universal UV curable ink, by weight, comprises the following raw materials: 40 parts oligomer-A, 18 parts acrylate isoacrylate, 12 parts tripropylene glycol diacrylate, 2 parts acylphosphoxy photoinitiator-A, 2 parts pigment yellow 111, 1 part BYK-333 and 1 part defoamer BY.

[0061] The preparation method of the multi-substrate universal UV curable ink in this embodiment includes the following steps: mixing oligomer-A, isoacrylate, tripropylene glycol diacrylate, acylphosphoxy photoinitiator-A, pigment yellow 111, BYK-333 and defoamer BY evenly to obtain the multi-substrate universal UV curable ink.

[0062] Example 3

[0063] A multi-substrate universal UV curable ink, by weight, comprises the following raw materials: 60 parts oligomer-A, 28 parts acrylate isoacrylate, 22 parts tripropylene glycol diacrylate, 10 parts acylphosphoxy photoinitiator-A, 4 parts pigment yellow 111, 2.5 parts BYK-333 and 2.5 parts defoamer BY.

[0064] The preparation method of the multi-substrate universal UV curable ink in this embodiment includes the following steps: mixing oligomer-A, isoacrylate, tripropylene glycol diacrylate, acylphosphoxy photoinitiator-A, pigment yellow 111, BYK-333 and defoamer BY evenly to obtain the multi-substrate universal UV curable ink.

[0065] Example 4

[0066] This embodiment provides a universal UV-curable ink for multiple substrates and its preparation method. The specific implementation method is the same as that in Embodiment 1, except that pigment yellow 111 is replaced by an equal amount of pigment blue 60.

[0067] Example 5

[0068] This embodiment provides a universal UV-curable ink for multiple substrates and its preparation method. The specific implementation method is the same as that in Embodiment 1, except that pigment yellow 111 is replaced by an equal part of pigment purple 23.

[0069] Example 6

[0070] This embodiment provides a multi-substrate universal UV curable ink and its preparation method. The specific implementation method is the same as that in Embodiment 1, except that pigment yellow 111 is replaced by an equal part of pigment orange 38.

[0071] Example 7

[0072] This embodiment provides a universal UV-curable ink for multiple substrates and its preparation method. The specific implementation method is the same as that in Embodiment 1, except that oligomer-A is replaced by an equal amount of oligomer-B.

[0073] Example 8

[0074] This embodiment provides a universal UV-curable ink for multiple substrates and its preparation method. The specific implementation method is the same as that in Embodiment 1, except that: acylphosphoxy photoinitiator-A is replaced by an equal part of acylphosphoxy photoinitiator-B.

[0075] Example 9

[0076] This embodiment provides a universal UV-curable ink for multiple substrates and its preparation method. The specific implementation method is the same as that in Embodiment 1, except that: acylphosphoxy photoinitiator-A is replaced by an equal part of acylphosphoxy photoinitiator-C.

[0077] Example 10

[0078] This embodiment provides a universal UV-curable ink for multiple substrates and its preparation method. The specific implementation method is the same as that in Embodiment 1, except that: acylphosphoxy photoinitiator-A is replaced by an equal part of acylphosphoxy photoinitiator-D.

[0079] Example 11

[0080] This embodiment provides a multi-substrate universal UV curable ink and its preparation method. The specific implementation method is the same as that in Embodiment 1, except that: the isoacrylate is replaced by an equal part of tripropylene glycol diacrylate.

[0081] Example 12

[0082] This embodiment provides a multi-substrate universal UV curable ink and its preparation method. The specific implementation method is the same as that in Embodiment 1, except that tripropylene glycol diacrylate is replaced by an equal part of acrylate isoacrylate.

[0083] Example 13

[0084] This embodiment provides a multi-substrate universal UV curable ink and its preparation method. The specific implementation method is the same as that in Embodiment 1, except that pigment yellow 111 is replaced by an equal amount of carbon black.

[0085] Performance testing

[0086] Aluminum foil, PET film and glass were selected as the substrates respectively. The UV-curable inks obtained in each embodiment were printed through the same printing machine to obtain printed products. The performance of the printed products was tested 1 and 2.

[0087] 1. Ink fastness test: Use a cross-cutting tool to cut the ink layer once in each of the vertical and horizontal directions, forming small squares of 5mm × 5mm. Then, apply 3M tape and peel the tape off from a 180° angle. The percentage of remaining squares reflects the ink adhesion. A percentage of remaining squares of 66%–100% is grade 0, 36%–65% is grade 1, 16%–35% is grade 2, 5%–15% is grade 3, 0%–1% is grade 4, and no peeling is grade 5.

[0088] 2. Flexibility test: The flexibility of the ink layer on the printed material was tested using a shaft bending tester. The ink flexibility was divided into 7 levels, from 1 to 7, with the higher the level, the better the flexibility.

[0089] 3. Resistance test: A surface resistivity meter is used to measure the resistance of the printed surface. The lower the surface resistivity, the stronger the antistatic performance.

[0090] The performance test results are shown in Table 1.

[0091] Table 1

[0092]

[0093]

[0094] As shown in Table 1, the inks of Examples 1-3 exhibit excellent flexibility after curing and good adhesion to substrates such as aluminum foil, PET film, and glass. The change in resistance before and after printing indicates that the inks also possess a certain degree of antistatic properties. The ink adhesion results from Examples 1, 4-6, and 13 demonstrate that, compared to black pigments, the photoinitiator in the UV-curable inks of this invention provides better photocuring effects for yellow, orange, purple, and blue pigments.

[0095] Compared to Example 1, the oligomer used in Example 7 did not contain terminal hydroxyl polybutadiene during synthesis, resulting in a decrease in the flexibility of the ink and an inability to effectively release the internal stress of the main chain, thereby reducing the ink's adhesion. At the same time, the changes in ink adhesion on different substrates show that the ink without terminal hydroxyl polybutadiene has lower adhesion on plastic and glass substrates than on metal substrates. This may be because the introduction of terminal hydroxyl polybutadiene also brings a certain degree of antistatic properties to the ink.

[0096] Compared to Example 1, the amount of indole introduced during the synthesis of the photoinitiator used in Example 8 did not significantly improve the degree of molecular conjugation, resulting in a slight shift in its absorption wavelength, which affected the photocuring effect and consequently the ink's adhesion.

[0097] Compared to Example 1, the amount of allyl bromide used in the photoinitiator in Examples 9-10 was changed during synthesis, which affected the compatibility between the photoinitiator and the oligomers in the ink, thus affecting the ink's fastness to some extent.

[0098] Compared to Example 1, Examples 11-12 used a single monomer to adjust the viscosity of the oligomer, which reduced the toughness of the ink and affected the adhesion of the ink layer when facing thinner substrates such as aluminum foil and PET film.

[0099] The embodiments described above do not limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A universal UV-curable ink for multiple substrates, characterized in that, By weight, it comprises the following raw materials: 40-60 parts oligomer, 30-50 parts compound monomer, 2-10 parts acylphosphoxy photoinitiator, 2-4 parts pigment and 2-5 parts additives; wherein the additives include dispersant and defoamer; the absorption band of the acylphosphoxy photoinitiator is 300-400nm.

2. The multi-substrate universal UV-curable ink according to claim 1, characterized in that, The pigment is any one of the following: yellow, blue, orange, and purple.

3. The multi-substrate universal UV-curable ink according to claim 1, characterized in that, The preparation steps of the acyl phosphorus photoinitiator are as follows: S1. At room temperature, 2,2'-dithiosalicylic acid, phosphorus pentoxide and concentrated sulfuric acid are stirred at 1-5℃ for 5-30 min. Then indole is added and stirred under nitrogen for 50-60 min. Then the temperature is raised to 70-90℃ and stirred for 4-6 h. After stirring, it is dropped into boiling water and stirred for 4-8 min. After cooling, filtering, washing and recrystallizing, reactant 1 is obtained. S2. At room temperature, dissolve NaH in DMF, add reactant 1 obtained in step S1, stir at 1-3℃ for 30-40 min, add allyl bromide, stir at 20-30℃ for 2-4 h, quench the reaction with saturated ammonium chloride solution, extract, wash, dry with anhydrous sodium sulfate, filter, distill under reduced pressure, recrystallize to obtain reactant 2. S3. Dissolve reactant 2 in 1,2-dichloroethane, cool to 1-3℃, add DMF and POCl3, stir for 5-15 min, heat to 80-90℃, stir for 20-28 h, quench the reaction with 10wt% sodium hydroxide solution, extract, wash, dry with anhydrous sodium sulfate, filter, distill under reduced pressure, and recrystallize to obtain the acylphosphooxy photoinitiator.

4. The multi-substrate universal UV-curable ink according to claim 3, characterized in that, In step S1, the mass ratio of 2,2'-dithiosalicylic acid to indole is 1:(2-3).

5. The multi-substrate universal UV-curable ink according to claim 3, characterized in that, In step S2, the mass ratio of reactant 1 to allyl bromide is 1:(1.16-1.32).

6. The multi-substrate universal UV-curable ink according to claim 3, characterized in that, In step S3, the mass ratio of reactant 2 to POCl3 is 1:(0.02-0.04).

7. The multi-substrate universal UV-curable ink according to claim 1, characterized in that, The preparation steps of the oligomer are as follows: Hydroxyl-terminated polybutadiene, IPDI, and ethyl acetate were stirred until completely dissolved. Stannous octoate was added, and the mixture was stirred at 80-100°C for 1-2 hours. Polypropylene glycol was added and stirred for 2-4 hours. Dimethylolpropionic acid, 1,4-butanediol, and acetone were added and stirred at 70-90°C for 1-2 hours. Stannous octoate was then added and stirred for 3-5 hours. After cooling to room temperature, TEA was added for emulsification, followed by rotary evaporation to obtain the oligomer.

8. The multi-substrate universal UV-curable ink according to claim 1, characterized in that, The compound monomers include isoacrylate and tripropylene glycol diacrylate.

9. The multi-substrate universal UV-curable ink according to claim 8, characterized in that, The mass ratio of the isoacrylate to the tripropylene glycol diacrylate is 1:(0.6-0.8).

10. A method for preparing a multi-substrate universal UV-curable ink according to any one of claims 1-9, characterized in that, The preparation steps are as follows: the oligomer, compound monomer, acylphosphophosphorus photoinitiator, pigment and additives are mixed evenly to obtain the multi-substrate universal UV curable ink.

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