Inkjet printing ink composition, inkjet printing ink and inkjet direct plate-making material

Abstract

The present application provides an inkjet printing ink composition, an inkjet printing ink and an inkjet direct plate-making material. The inkjet printing ink composition includes: 10-60 parts by weight of a UV prepolymer, 1-10 parts by weight of a photoinitiator, and 30-80 parts by weight of an active diluent monomer. The UV prepolymer includes a silicone-modified epoxy acrylate prepolymer to improve the water resistance and adhesion of the plate-making material formed by using the ink composition, thereby enhancing the printing resistance.

Description

Technical Field

[0001] This application relates to the technical field of inkjet printing, and particularly relates to an inkjet printing ink composition, an inkjet printing ink, and an inkjet direct plate-making material. Background Art

[0002] As an additive manufacturing printing process, inkjet printing has the advantages of energy conservation, environmental protection, and variable data. UV inkjet printing has no VOC emissions, can rapidly shape materials, and can achieve three-dimensional printing and plate-making by layer-by-layer printing, so it has great advantages in intaglio plate-making. Most UV inkjet inks on the market adopt a free radical photo-curing system. The free radical photo-curing system has a fast curing speed and low raw material prices, but free radical photo-curing has serious oxygen inhibition of polymerization, which easily leads to poor surface curing; the free radical photo-curing process will cause volume shrinkage, affecting the adhesion performance of products.

[0003] Chinese Patent Application with Publication No. CN103991270A provides an intaglio printing plate cylinder based on inkjet protection for reuse and its printing method. A number of mesh cavities with the same depth and evenly arranged are provided on the entire surface of the intaglio printing roller. Using inkjet printing technology, oil-repellent ink droplets are sprayed into the mesh cavities in the non-graphic areas to obtain a printing plate. After printing, the ink droplets in the mesh cavities are washed off, and the plate can be re-made. The intaglio printing roller obtained by this method can be reused, but the production process of the intaglio printing roller is the same as the existing intaglio printing roller production process, which requires copper plating, then electro-engraving, and then chromium plating, with high production costs and complex processes. Moreover, the plate-making ink uses hot-melt and ordinary ultraviolet light-curing inks, with poor wear resistance and low printing resistance. Summary of the Invention

[0004] This application provides an inkjet printing ink composition, an inkjet printing ink, and an inkjet direct plate-making material to improve the water resistance and adhesion of the plate material and thus enhance the printing resistance.

[0005] In a first aspect of this application, an inkjet printing ink composition is provided. The inkjet printing ink composition includes: 10-60 parts by weight of a UV prepolymer, 1-10 parts by weight of a photoinitiator, and 30-80 parts by weight of an active diluent monomer. The UV prepolymer includes an organosilicon-modified epoxy acrylate prepolymer.

[0006] In any implementation manner of the first aspect of this application, the organosilicon-modified epoxy acrylate prepolymer has the structure shown in Formula I.

[0007]

[0008] Among them, m is any integer from 1 to 50, and each R1 is independently any one of C1-C50 alkylene groups, C2-C50 alkenylene groups, and C6-C30 arylene groups; preferably, each R1 is independently any one of C1-C20 alkylene groups, C2-C20 alkenylene groups, and C6-C20 arylene groups, and more preferably, each R1 is independently an alkylene group of C1 to C8, an alkenylene group of C2-C6, or a phenyl group; R2 is any one of a hydroxyl group, a C1-C10 alkoxy group, and a phenoxy group, preferably R2 is any one of a hydroxyl group, a C1-C3 alkoxy group, and a phenoxy group, and more preferably, R2 is a hydroxyl group, a methoxy group, or a phenoxy group.

[0009] In any embodiment of the first aspect of the present application, the number-average molecular weight of the organosilicon-modified epoxy acrylate prepolymer is 20,000-80,000; preferably, the number-average molecular weight of the organosilicon-modified epoxy acrylate prepolymer is 30,000-60,000.

[0010] In any embodiment of the first aspect of the present application, the UV prepolymer further includes one or more of a polyurethane acrylate prepolymer, a polyester acrylate prepolymer, an acrylate prepolymer, and an organosilicon oligomer. Preferably, the mass content of the organosilicon-modified epoxy acrylate prepolymer in the UV prepolymer is greater than 50%.

[0011] In any embodiment of the first aspect of the present application, the photoinitiator includes a free radical photoinitiator and a cationic photoinitiator; the molar ratio of the free radical photoinitiator to the cationic photoinitiator is (4-8):1.

[0012] In any embodiment of the first aspect of the present application, the free radical photoinitiator is selected from one or more of (2,4,6-trimethylbenzoyl) diphenylphosphine oxide, 2-isopropylthioxanthone, benzophenone, 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinobenzylphenyl) butanone, and α-hydroxyisopropylbenzophenone; and / or the cationic photoinitiator is selected from one or more of diphenyliodonium hexafluoroarsenate, benzoylaniline salt, and benzoyl phenothiazine salt.

[0013] In any embodiment of the first aspect of the present application, the active diluent monomer includes an acrylate monomer having a vinyl ether group at the end. Preferably, the active diluent monomer is selected from one or more of vinyl ether group-tetrahydrofuran acrylate, vinyl ether group-1,6-hexanediol diacrylate, vinyl ether diethylene glycol diacrylate, vinyl ether group-2-phenoxyethyl acrylate, vinyl ether group-2-phenoxyethyl acrylate, vinyl ether group-dipropylene glycol diacrylate, and vinyl ether group-pentaerythritol triacrylate.

[0014] In any embodiment of the first aspect of the present application, the inkjet printing ink composition further comprises 0.01 - 5 parts by weight of an auxiliary agent, and the auxiliary agent comprises a fluorine-modified polysilane. Preferably, the fluorine-modified polysilane comprises polytrifluoropropylmethylsiloxane and organofluoro polydimethylsiloxane.

[0015] The second aspect of the present application provides an inkjet printing ink, which is mixed with the inkjet printing ink composition provided in any embodiment of the first aspect. Preferably, the rotational viscosity of the inkjet printing ink at 25 °C is 3 mPa·s - 30 mPa•s.

[0016] The third aspect of the present application provides an inkjet direct platemaking plate, which is prepared by an inkjet direct platemaking process. The ink used in this inkjet direct platemaking process is the inkjet printing ink provided in any embodiment of the second aspect. Preferably, the surface energy of the inkjet direct platemaking plate is 32 mN / m - 36 mN / m; preferably, the cell depth of the inkjet direct platemaking plate is 10 μm - 100 μm, and more preferably 30 μm - 60 μm.

[0017] In any embodiment of the third aspect of the present application, the inkjet direct platemaking process includes using an inkjet printer to layer and print the ink onto a drum plate base or a flat plate base, and then performing photocuring to form the cell structure of the gravure to obtain the plate. Preferably, the photocuring is performed using a UV-LED light source. Further preferably, the wavelength of the UV-LED light source is between 365 nm and 410 nm, and more preferably, the light intensity of the UV-LED light source is greater than 6 W / cm 2 。

[0018] The organosilicon-modified epoxy acrylate prepolymer in the inkjet printing ink composition of the present application can participate in both free radical photocuring reaction and cationic photocuring reaction, which can effectively reduce oxygen inhibition polymerization, achieve high curing speed and high crosslinking density, and has excellent water resistance. Moreover, the organosilicon-modified epoxy acrylate prepolymer can significantly reduce the brittleness of the epoxy resin, increase toughness and chain segment elasticity, improve adhesion, enable the ink formed by the composition of the present application to achieve multi-layer superimposed printing on a drum or flat plate base, alleviate the occurrence of brittle cracking and peeling of the ink layer, and has extremely high printing resistance. Even in some embodiments, the printing resistance of the formed plate can reach 50,000 impressions. In addition, since cationic oxidation sensitization can only be initiated at very high energies, the ink formed by the ink composition of the present application has high storage stability in a normal environment and is not prone to film-forming curing phenomenon. Detailed Embodiments

[0019] The following further describes the embodiments of the present application in detail with reference to the examples. The detailed descriptions of the following examples are used to exemplarily illustrate the principles of the present application, but cannot be used to limit the scope of the present application, that is, the present application is not limited to the described examples.

[0020] As analyzed in the background art of the present application, the printing resistance of the existing inkjet direct plate-making materials is insufficient. To solve this problem, the present application provides an inkjet printing ink composition, an inkjet printing ink, and an inkjet direct plate-making material.

[0021] In the first embodiment of the present application, an inkjet printing ink composition is provided. The inkjet printing ink composition includes: 10-60 parts by weight of a UV prepolymer, 1-10 parts by weight of a photoinitiator, and 30-80 parts by weight of an active diluent monomer. The UV prepolymer includes a silicone-modified epoxy acrylate prepolymer.

[0022] The silicone-modified epoxy acrylate prepolymer in the inkjet printing ink composition of the present application can participate in both free radical photocuring reactions and cationic photocuring reactions, effectively reducing oxygen inhibition polymerization, achieving high curing speeds and high crosslinking densities, and having excellent water resistance. Moreover, the silicone-modified epoxy acrylate prepolymer can significantly reduce the brittleness of the epoxy resin, increase toughness and the elasticity of the chain segments, improve adhesion, enabling the ink formed from the composition of the present application to achieve multi-layer superimposed printing on a drum or flat plate base, alleviating the occurrence of brittle cracking and peeling of the ink layer, and having extremely high printing resistance. In some embodiments, the printing resistance of the plate material formed can even reach 50,000 impressions. Additionally, since cationic oxidation sensitization can only be initiated at very high energies, the ink formed from the ink composition of the present application has high storage stability in a normal environment and is not prone to film-forming curing phenomena.

[0023] The silicone-modified epoxy acrylate prepolymer used in the present application can be prepared by known preparation methods or can be a commercial silicone-modified epoxy acrylate prepolymer.

[0024] In some embodiments, the inkjet printing ink composition includes: 30-50 parts by weight of a UV prepolymer, 6-10 parts by weight of a photoinitiator, and 35-65 parts by weight of an active diluent monomer.

[0025] In some embodiments of the present application, the silicone-modified epoxy acrylate prepolymer has the structure shown in Formula I.

[0026]

[0027] Among them, m is any integer from 1 to 50, and each R1 is independently any one of C1-C50 alkylene groups, C2-C50 alkenylene groups, and C6-C30 arylene groups; preferably, each R1 is independently any one of C1-C20 alkylene groups, C2-C20 alkenylene groups, and C6-C20 arylene groups, and more preferably, each R1 is independently an alkylene group of C1 to C8, an alkenylene group of C2-C6, or a phenyl group; R2 is any one of a hydroxyl group, an alkoxy group, and a phenoxy group, preferably R2 is any one of a hydroxyl group, a C1-C3 alkoxy group, and a phenoxy group, and more preferably R2 is a hydroxyl group, a methoxy group, or a phenoxy group.

[0028] The above-mentioned organosilicon-modified epoxy acrylate prepolymer grafts an organosilicon group between two epoxy acrylate groups, enhancing the stretchability of the prepolymer chain segment, greatly increasing the flexibility, water resistance, and heat resistance of the prepolymer. Moreover, the hydroxyl group, methoxy group, and phenoxy group in the organosilicon group can have good adhesion to metals, so the adhesion of the ink to the printing plate base is improved by using R2. And when the molar ratio of the epoxy group to the acrylate group is 1:1, the curing shrinkage of the acrylate can be greatly reduced, and the adhesion can be improved.

[0029] In addition, when R1 is selected from C1-C50 alkylene groups and C2-C50 alkenylene groups, the alicyclic epoxy group does not have a benzene ring and will not photolyze to produce quinone intermediates like bisphenol A epoxy, causing yellowing of the system and embrittlement of the ink layer.

[0030] In some embodiments, m in the above formula I can be preferably 1-30, 1-20, 1-15, etc., such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 18, 20, 25, 30, 35, 40, 45, or 50.

[0031] In some embodiments, each R1 is independently a methylene group, an ethylene group, a propylene group, a vinylidene group, a propenyl group, or a phenyl group, and preferably each R1 is independently a methylene group, an ethylene group, a vinylidene group, or a phenyl group. More preferably, each R1 is independently a methylene group, an ethylene group, or a vinylidene group.

[0032] In some embodiments, the number-average molecular weight of the organosilicon-modified epoxy acrylate prepolymer is 20,000-80,000; preferably, the number-average molecular weight of the organosilicon-modified epoxy acrylate prepolymer is 30,000-60,000. The number-average molecular weight in this range makes the viscosity of the formed ink less than 30 mPa•s. Moreover, if the molecular weight of the prepolymer is too small, there are too few active groups, which affects the performance of the prepolymer. If the molecular weight of the prepolymer is too large, the viscosity is too high, and in order to meet the good printing requirements, the addition amount of the prepolymer in the ink is very small, resulting in an insignificant performance effect of the prepolymer. And the prepolymer with too high molecular weight has too long chain segments, the crosslinking rate becomes low, and the improvement effect on the water resistance of the ink is insufficient.

[0033] In some embodiments, the UV prepolymer further includes one or more of polyurethane acrylate prepolymer, polyester acrylate prepolymer, acrylate prepolymer, and silicone oligomer. Preferably, the mass content of the silicone-modified epoxy acrylate prepolymer in the UV prepolymer is greater than 50%. When the content is greater than 50%, oxygen inhibition polymerization can be more effectively reduced, volume shrinkage can be reduced, the flexibility and water resistance of the system can be more significantly improved, and the printing resistance can be better improved. The silicone-modified epoxy acrylate prepolymer combined with the conventional UV prepolymer can greatly reduce the cost of the product.

[0034] Those skilled in the art can adjust the polymerization rate of the prepolymer and the mechanical properties of the resulting cured product by adjusting the composition of the photoinitiator. In some embodiments, the photoinitiator includes a free radical photoinitiator and a cationic photoinitiator; the molar ratio of the free radical photoinitiator to the cationic photoinitiator is (4 - 8):1. The free radical photoinitiator is used to initiate the free radical photopolymerization reaction, and the higher the proportion of the free radical photoinitiator, the greater the photopolymerization rate and crosslinking density, and the better the water resistance of the formed plate. When the molar ratio of the free radical photoinitiator to the cationic photoinitiator is (4 - 8):1, the sensitization efficiency of the cationic photoinitiator is also relatively high, which can simultaneously greatly improve the volume shrinkage defect caused by free radical photopolymerization, better improve the toughness and adhesion of the formed plate, and further improve the printing resistance.

[0035] The free radical photoinitiator and the cationic photoinitiator used in the present application are selected from the corresponding initiator types commonly used in the prior art. In some embodiments, the above-mentioned free radical photoinitiator includes, but is not limited to, one or more of (2,4,6-trimethylbenzoyl) diphenylphosphine oxide, 2-isopropylthioxanthone, benzophenone, 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinobenzylphenyl) butanone, and α-hydroxyisopropylbenzophenone.

[0036] In some embodiments, the cationic photoinitiator includes, but is not limited to, one or more of diphenyliodonium hexafluoroarsenate, benzoylaniline salt, and benzoyl phenothiazine salt.

[0037] The free radical initiator in the above inkjet printing ink composition can absorb the energy of wavelengths from 365 nm to 405 nm, and the generated free radicals can be oxidized and sensitized by the cationic photoinitiator to initiate cationic polymerization, so that the initiation wavelength of the cationic photoinitiator transitions from 250 - 300 nm to 365 - 405 nm, realizing UV-LED cationic photocuring and avoiding the high energy consumption and ozone pollution of mercury lamps.

[0038] In addition, experiments have found that the cationic initiators diphenyliodonium hexafluoroarsenate, benzoylaniline salt, and benzoyl phenothiazine salt can be easily sensitized, the initiation wavelength can reach 365 - 405 nm, and the initiation efficiency is high.

[0039] The reactive diluent monomer can be selected from conventional photo-initiated reactive diluent monomers. In some embodiments, the reactive diluent monomer includes an acrylate monomer having a vinyl ether at the end. The vinyl ether-modified acrylate reactive diluent monomer has higher reactivity, which can greatly increase the reaction rate. Moreover, after the acrylate is modified with vinyl ether, the compatibility and solubility of the prepolymer and the cationic initiator are greatly increased, and the storage stability of the system is good.

[0040] In some embodiments, the reactive diluent monomer includes, but is not limited to, one or more of vinyl ether group-tetrahydrofuran acrylate, vinyl ether group-1,6-hexanediol diacrylate, vinyl ether diethylene glycol diacrylate, vinyl ether group-2-phenoxyethyl acrylate, vinyl ether group-2-phenoxyethyl acrylate, vinyl ether group-dipropylene glycol diacrylate, vinyl ether group-pentaerythritol triacrylate.

[0041] In some embodiments, the inkjet printing ink composition further includes 0.01-5 parts by weight of an auxiliary agent, and the auxiliary agent includes a fluorine-modified polysilane. Due to the better hydrophobicity of the fluorine-modified polysilane, the cured ink formed by the ink composition has a lower surface energy and better abrasion resistance. In some embodiments, the fluorine-modified polysilane includes, but is not limited to, polytrifluoropropylmethylsiloxane and organofluoro-polydimethylsiloxane.

[0042] In the second embodiment of the present application, an inkjet printing ink is provided. The inkjet printing ink is mixed with any one of the inkjet printing ink compositions in the first embodiment above. Preferably, the rotational viscosity of the inkjet printing ink at 25 °C is 3 mPa·s - 30 mPa·s.

[0043] The organosilicon-modified epoxy acrylate prepolymer in the inkjet printing ink of the present application can participate in both free radical photo-curing reaction and cationic photo-curing reaction, which can effectively reduce oxygen inhibition polymerization, achieve high curing speed and high crosslinking density, and has excellent water resistance. Moreover, the organosilicon-modified epoxy acrylate prepolymer can significantly reduce the brittleness of the epoxy resin, increase toughness and the elasticity of the chain segment, improve adhesion, enable the ink to achieve multi-layer superimposed printing on a drum or flat plate substrate, alleviate the occurrence of brittle cracking and peeling of the ink layer, and has extremely high printing resistance. Even in some embodiments, the printing resistance of the formed plate can reach 50,000 impressions. In addition, since cationic oxidation sensitization can only be initiated when the energy is very high, the ink of the present application has high storage stability in a normal environment and is not prone to film-forming curing phenomenon.

[0044] The third embodiment of the present application provides an inkjet direct plate-making material, which is prepared by an inkjet direct plate-making process. The ink used in this inkjet direct plate-making process is the inkjet printing ink provided by the second embodiment. Preferably, the surface energy of the inkjet direct plate-making material is 32 mN / m - 36 mN / m.

[0045] The plate-making material of the present application has excellent water resistance and extremely high printing resistance. In some embodiments, the printing resistance of the formed plate-making material can reach 50,000 impressions. Since the above ink can be overprinted unlimitedly, the cell depth of the inkjet direct plate-making material can be adjusted arbitrarily, and the cell depths in different regions can also be controlled and adjusted. For plate bases with different printing pattern and color requirements, plate bases with different cell depths can be used. The cell depth of the inkjet direct plate-making material is controllable within 10 μm - 100 μm. In some embodiments, the cell depth of the inkjet direct plate-making material is 30 μm - 60 μm, and the printing effect is better.

[0046] In some embodiments, the above inkjet direct plate-making process includes using an inkjet printer to layer and stack the ink onto a roller plate base or a flat plate base, and then performing photocuring to form the cell structure of the gravure plate to obtain the plate-making material. Preferably, the photocuring uses a UV-LED light source. Further preferably, the wavelength of the UV-LED light source is between 365 nm and 410 nm. In some embodiments, the wavelength of the UV-LED light source is selected from one or more of 365 nm, 375 nm, 385 nm, 395 nm, and 405 nm. More preferably, the light intensity of the UV-LED light source is greater than 6 W / cm 2 .

[0047] The above inkjet printer can be obtained through commercial purchase. The print head is a print head suitable for the UV system. Preferably but not limited to Ricoh, Konica Minolta, Kyocera, Starlight, Epson, Xaar, Fujifilm, Samba, Toshiba, Samsung, and Panasonic print heads.

[0048] Hereinafter, the beneficial effects of the present application will be further described in combination with examples and comparative examples, but the scope of the present invention is not limited to these examples.

[0049] Compound description:

[0050]

[0051]

[0052]

[0053] The sources of the above organosilicon-modified epoxy acrylate prepolymers are as follows:

[0054] The organosilicon-modified epoxy acrylate prepolymers A1 - A5 all come from Guangdong Boxing.

[0055] Example 1

[0056] Add (2,4,6 - trimethylbenzoyl) diphenylphosphine oxide accounting for 4 wt% of the total ink amount, 2 - isopropylthioxanthone accounting for 1 wt%, and benzoyl phenothiazine salt accounting for 1 wt% to a mixture of 40 wt% of vinyl ether - tetrahydrofuran acrylate and 23 wt% of vinyl ether - dipropylene glycol diacrylate, stir until completely dissolved, and then add 30 wt% of organosilicon - modified epoxy acrylate prepolymer A1 (molecular weight 35,000), 1 wt% of organofluorine polydimethylsiloxane (purchased from Evonik) and stir to disperse evenly to obtain the photocurable inkjet ink B1.

[0057] On a cleaned metal roller, use a Ricoh G5 nozzle to layer - by - layer print the photocurable inkjet ink B1 onto the roller, print 4 layers, and use a UV - LED light source with a light intensity of 8 W / cm 2 , with a wavelength of 395 nm for photocuring molding to construct the gravure cell structure, and obtain a roller C1 applicable to gravure printing.

[0058] Example 2

[0059] Add α - hydroxyisopropylbenzophenone accounting for 5.5 wt% of the total ink amount and diphenyliodonium hexafluoroarsenate accounting for 1 wt% to 48 wt% of vinyl ether - diethylene glycol diacrylate, stir until completely dissolved, and then add 25 wt% of organosilicon - modified epoxy acrylate prepolymer A1 (molecular weight 35,000), 20% of polyurethane acrylate (molecular weight 50,000, purchased from Double Bond Chemical Industry), and 0.5 wt% of organofluorine polydimethylsiloxane (purchased from Evonik) and stir to disperse evenly to obtain the photocurable inkjet ink B2.

[0060] On a cleaned metal roller, use a Ricoh G5 nozzle to layer - by - layer print the photocurable inkjet ink B2 onto the roller, print 4 layers, and use a UV - LED light source with a light intensity of 8 W / cm 2 , with a wavelength of 365 nm for photocuring molding to construct the gravure cell structure, and obtain a roller C2 applicable to gravure printing.

[0061] Example 3

[0062] Add (2,4,6 - trimethylbenzoyl) diphenylphosphine oxide accounting for 5 wt% of the total ink amount, benzophenone accounting for 3 wt%, and benzoylaniline salt accounting for 2 wt% to 47 wt% of vinyl ether - diethylene glycol diacrylate, stir until completely dissolved, and then add 40 wt% of organosilicon - modified epoxy acrylate prepolymer A2 (molecular weight 60,000), 3 wt% of polytrifluoropropylmethylsiloxane (purchased from Hubei Fangde New Materials Co., Ltd.) and stir to disperse evenly to obtain the photocurable inkjet ink B3.

[0063] On the cleaned metal roller, use a Ricoh G5 print head to layer and print the photo-curable inkjet ink B2 onto the roller, printing 4 layers, and cure it using a UV-LED light source with a light intensity of 12 W / cm 2 , a wavelength of 385 nm, to form the recessed cell structure of the gravure plate, and obtain the roller C3 applicable to gravure printing.

[0064] Example 4

[0065] Add 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinobenzylphenyl)butanone accounting for 5.5 wt% of the total ink amount and diphenyliodonium hexafluoroarsenate accounting for 1 wt% into 42 wt% of vinyl ether-based 2-phenoxyethyl acrylate, stir until completely dissolved, and then add 50 wt% of organosilicon-modified epoxy acrylate prepolymer A3 (molecular weight 50,000) and 1.5 wt% of polytrifluoropropylmethylsiloxane (purchased from Hubei Fangde New Materials Co., Ltd.), stir and disperse evenly to obtain the photo-curable inkjet ink B4.

[0066] On the cleaned metal roller, use a Ricoh Konica 1024i print head to layer and print the photo-curable inkjet ink B4 onto the roller, printing 4 layers, and cure it using a mixed UV-LED light source with a light intensity of 15 W / cm 2 , a wavelength of 365 nm and 405 nm in a ratio of 1:5, to form the recessed cell structure of the gravure plate, and obtain the roller C4 applicable to gravure printing.

[0067] Example 5

[0068] Add (2,4,6-trimethylbenzoyl)diphenylphosphine oxide accounting for 4 wt% of the total ink amount, 2-isopropylthioxanthone accounting for 1 wt%, and benzoyl phenothiazine salt accounting for 1 wt% into 35 wt% of vinyl ether-based 1,6-hexanediol diacrylate, stir until completely dissolved, and then add 35 wt% of organosilicon-modified epoxy acrylate prepolymer A3 (molecular weight 50,000), 22% of polyester acrylate (molecular weight 50,000, purchased from Double Bond Chemical Industry), and 2 wt% of organofluoro polydimethylsiloxane (purchased from Evonik), stir and disperse evenly to obtain the photo-curable inkjet ink B5.

[0069] On the cleaned metal roller, use an Epson 3200 print head to layer and print the photo-curable inkjet ink B5 onto the roller, printing 8 layers, and cure it using a UV-LED light source with a light intensity of 10 W / cm 2 , a wavelength of 395 nm, to form the recessed cell structure of the gravure plate, and obtain the roller C5 applicable to gravure printing.

[0070] Example 6

[0071] The ink was prepared and plate-making printing was carried out according to the method of Example 1, except that the content of the organosilicon-modified epoxy acrylate prepolymer A1 (molecular weight 35,000) was 10%, and the photocurable ink B6 was obtained.

[0072] The printed roller C6 applicable to intaglio printing was obtained.

[0073] Example 7

[0074] The ink was prepared and plate-making printing was carried out according to the method of Example 1, except that the organosilicon-modified epoxy acrylate prepolymer was A4 (molecular weight 20,000), and the photocurable ink B7 was obtained.

[0075] The printed roller C7 applicable to intaglio printing was obtained.

[0076] Example 8

[0077] The ink was prepared and plate-making printing was carried out according to the method of Example 1, except that the organosilicon-modified epoxy acrylate prepolymer was A5 (molecular weight 80,000), and the photocurable ink B8 was obtained.

[0078] The printed roller C8 applicable to intaglio printing was obtained.

[0079] Example 9

[0080] The ink was prepared and plate-making printing was carried out according to the method of Example 1, except that the prepolymer was 50% of the organosilicon-modified epoxy acrylate prepolymer A1 (molecular weight 35,000) and 50% of polyurethane acrylate (purchased from Double Bond Chemical Industry), and the photocurable ink B9 was obtained.

[0081] The printed roller C9 applicable to intaglio printing was obtained.

[0082] Example 10

[0083] The ink was prepared and plate-making printing was carried out according to the method of Example 1, except that the prepolymer was 30% of the organosilicon-modified epoxy acrylate prepolymer A1 (molecular weight 35,000) and 70% of polyurethane acrylate (purchased from Double Bond Chemical Industry), and the photocurable ink B10 was obtained.

[0084] The printed roller C10 applicable to intaglio printing was obtained.

[0085] Example 11

[0086] The ink was prepared and plate-making printing was carried out according to the method of Example 1, except that the total content of the photoinitiator was 1%, including 0.6 wt% of (2,4,6-trimethylbenzoyl) diphenylphosphine oxide, 0.2 wt% of 2-isopropylthioxanthone, and 0.2 wt% of benzoyl phenothiazine salt, and the photocurable ink B11 was obtained.

[0087] Print to obtain a roller C11 applicable to intaglio printing.

[0088] Example 12

[0089] Prepare the ink according to the method of Example 1 and perform plate making and printing. The difference is that the ratio of the free radical photoinitiator to the cationic photoinitiator in the photoinitiator is 8:1, including 4.26 wt% of (2,4,6-trimethylbenzoyl) diphenylphosphine oxide, 1.07 wt% of 2-isopropylthioxanthone, and 0.67 wt% of benzoyl phenothiazine salt, to obtain a photocurable ink B12.

[0090] Print to obtain a roller C12 applicable to intaglio printing.

[0091] Example 13

[0092] Prepare the ink according to the method of Example 1 and perform plate making and printing. The difference is that the ratio of the free radical photoinitiator to the cationic photoinitiator in the photoinitiator is 3:1, including 3.6 wt% of (2,4,6-trimethylbenzoyl) diphenylphosphine oxide, 0.9 wt% of 2-isopropylthioxanthone, and 1.5 wt% of benzoyl phenothiazine salt, to obtain a photocurable ink B13.

[0093] Print to obtain a roller C13 applicable to intaglio printing.

[0094] Example 14

[0095] Prepare the ink according to the method of Example 1 and perform plate making and printing. The difference is that the ratio of the free radical photoinitiator to the cationic photoinitiator in the photoinitiator is 9:1, including 4.32 wt% of (2,4,6-trimethylbenzoyl) diphenylphosphine oxide, 1.08 wt% of 2-isopropylthioxanthone, and 0.6 wt% of benzoyl phenothiazine salt, to obtain a photocurable ink B14.

[0096] Print to obtain a roller C14 applicable to intaglio printing.

[0097] Example 15

[0098] Prepare the ink according to the method of Example 1 and perform plate making and printing. The difference is that the active diluent is a mixture of 15 wt% of vinyl ether-based tetrahydrofuran acrylate and 15 wt% of vinyl ether-based dipropylene glycol diacrylate to obtain a photocurable ink B15.

[0099] Print to obtain a roller C15 applicable to intaglio printing.

[0100] Example 16

[0101] The ink was prepared and plate-making printing was carried out according to the method of Example 1, except that the content of organofluoro polydimethylsiloxane (purchased from Evonik) was 5%, and the photocurable ink B16 was obtained.

[0102] The printed roller C16 applicable to intaglio printing was obtained.

[0103] Example 17

[0104] The ink was prepared and plate-making printing was carried out according to the method of Example 1, except that the cationic initiator was triaryl sulfonium hexafluorophosphate salt, and the photocurable inkjet ink B17 was obtained.

[0105] The printed roller C17 applicable to intaglio printing was obtained.

[0106] Example 18

[0107] The ink was prepared and plate-making printing was carried out according to the method of Example 1, except that the reactive diluent was 40 wt% of tetrahydrofurfuryl acrylate and 23 wt% of dipropylene glycol diacrylate, and the photocurable inkjet ink B18 was obtained.

[0108] The printed roller C18 applicable to intaglio printing was obtained.

[0109] Example 19

[0110] The ink was prepared and plate-making printing was carried out according to the method of Example 1, except that the auxiliary agent was polyether silane (purchased from Changhui Chemical Industry), and the photocurable inkjet ink B19 was obtained.

[0111] The printed roller C19 applicable to intaglio printing was obtained.

[0112] Comparative Example 1

[0113] The ink was prepared and plate-making printing was carried out according to the method of Example 1, except that the prepolymer was polyurethane acrylate (with a molecular weight of 35,000, purchased from Double Bond Chemical Industry), and the photocurable inkjet ink B20 was obtained.

[0114] The printed roller C20 applicable to intaglio printing was obtained.

[0115] Comparative Example 2

[0116] Add (2,4,6-trimethylbenzoyl) diphenylphosphine oxide accounting for 4 wt% of the total ink volume, 2-isopropylthioxanthone accounting for 1 wt%, and triaryl sulfonium hexafluorophosphate accounting for 1 wt% into a mixture of 40 wt% of tetrahydrofuran acrylate and 23 wt% of dipropylene glycol diacrylate, stir until completely dissolved, and then add 30 wt% of polyurethane acrylate (with a molecular weight of 35,000, purchased from Double Bond Chemical Industry) and 1 wt% of polyether silane (purchased from Changhui Chemical Industry), and stir and disperse evenly to obtain the photocurable inkjet ink B21.

[0117] On a cleaned metal roller, use a Ricoh G5 print head to layer by layer print the photocurable inkjet ink B1 onto the roller, print 4 layers, and use a UV-LED light source with a light intensity of 8 W / cm 2 , with a wavelength of 395 nm for photocuring molding to construct the recessed cell structure of the gravure plate, and obtain the roller C21 applicable to gravure printing.

[0118] Test Examples

[0119] (1) Viscosity Test

[0120] Testing Equipment: Rheometer (Anton Paar Shanghai Trading Co., Ltd.), Model: MCR 302.

[0121] (2) Surface Energy Test after Ink Curing

[0122] Testing Equipment: KRUSS Portable Contact Angle Measuring Instrument, Model: MSA.

[0123] (3) Stability Test

[0124] Testing Method: After the ink is stably placed for a period of time, test the viscosity. If the change rate of the viscosity compared with the initial value is less than 3%, the stability is qualified.

[0125] (4) Crosslinking Rate

[0126] Testing Method: Take 1 g of ink and place it on a glass slide, and test the conversion rates of double bonds and epoxy under the irradiation of the UV-LED light source in a Fourier transform infrared spectrometer equipped with a UV-LED light source, which is the crosslinking rate.

[0127] (5) Cell Depth

[0128] Testing Equipment: Kosaka Step Gauge, Model: ET200A.

[0129] (6) Flexibility

[0130] Pull a film with a thickness of 30 microns of the ink on a plastic film, and after curing, fold the film 180° back and forth once. If there is no break at the crease observed under a magnifying glass, it is qualified.

[0131] (7) Adhesion Test

[0132] Test method: Adhesion is tested using the 100-grid scratching method according to GBT9286-1998 Scratch test for paint and varnish films. Grade 0 is the best adhesion and Grade 5 is the worst.

[0133] (8) Water resistance

[0134] Test method: Soak the sample in tap water at room temperature (20-35℃) for a certain period of time, then take it out of the water. If the film is intact without blistering, peeling, or whitening, and passes the adhesion test, then the water resistance is qualified.

[0135]

[0136] (9) Printing durability

[0137] Testing equipment: gravure printing machine + stainless steel scraper.

[0138] The above test results are recorded in Table 1.

[0139]

[0140]

[0141] As can be seen from the data in Table 1, the photocurable inkjet ink of the present invention has low surface energy after curing, good storage stability, and can be stably stored for more than 15 months. The ink has a high curing crosslinking rate, good adhesion, good flexibility, good water resistance, and high print run.

[0142] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are merely examples, and any embodiments having substantially the same structure and effect as the technical concept within the scope of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the present application, any other embodiments that can be conceived by those skilled in the art and that combine some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. An inkjet printing ink composition, characterized in that The inkjet printing ink composition comprises: 10-60 parts by weight of UV prepolymer, 1-10 parts by weight of photoinitiator, and 30-80 parts by weight of active diluent monomer, wherein the photoinitiator comprises a free radical photoinitiator and a cationic photoinitiator, and the UV prepolymer comprises an organosilicon-modified epoxy acrylate prepolymer. The organosilicon-modified epoxy acrylate prepolymer has a number average molecular weight of 20,000 to 80,000 and has a structure shown in Formula I. Wherein, m is any integer from 1 to 50, each R1 is independently any one of a C1-C50 alkylene group, a C2-C50 alkenylene group, and a C6-C30 arylene group; and R2 is any one of a hydroxyl group, a C1-C10 alkoxy group, and a phenoxy group.

2. The inkjet printing ink composition according to claim 1, characterized in that Each R1 is independently any one of a C1-C20 alkylene group, a C2-C20 alkenylene group, and a C6-C20 arylene group; R2 is any one of a hydroxyl group, a C1-C3 alkoxy group, and a phenoxy group.

3. The inkjet printing ink composition according to claim 1 or 2, characterized in that Each R1 is independently any one of a C1-C8 alkylene group, a C2-C6 alkenylene group, and a phenyl group.

4. The inkjet printing ink composition according to claim 1 or 2, characterized in that R2 is hydroxy, methoxy or phenoxy.

5. The inkjet printing ink composition according to claim 3, characterized in that R2 is hydroxy, methoxy or phenoxy.

6. The inkjet printing ink composition according to claim 1 or 2, characterized in that The number average molecular weight of the organosilicon-modified epoxy acrylate prepolymer is 30,000-60,000.

7. The inkjet printing ink composition according to claim 1 or 2, characterized in that The UV prepolymer further includes one or more of polyurethane acrylate prepolymer, polyester acrylate prepolymer, acrylate prepolymer, and silicone oligomer.

8. The inkjet printing ink composition according to claim 1 or 2, characterized in that The mass content of the organosilicon-modified epoxy acrylate prepolymer in the UV prepolymer is greater than 50%.

9. The inkjet printing ink composition according to claim 1 or 2, characterized in that The mass ratio of the free radical photoinitiator to the cationic photoinitiator is (4-8):

1.

10. The inkjet printing ink composition according to claim 9, characterized in that The free radical photoinitiator is selected from one or more of (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, 2-isopropylthioxanthone, benzophenone, 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinobenzylphenyl)butanone, and α-hydroxyisopropylbenzophenone; and / or the cationic photoinitiator is selected from one or more of diphenyl hexafluoroarsenate iodonium salt, benzanilide salt, and benzoylphenothiazine salt.

11. The inkjet printing ink composition according to claim 1 or 2, characterized in that The reactive diluent monomer includes an acrylate monomer containing vinyl ether at the end.

12. The inkjet printing ink composition according to claim 11, characterized in that The active diluent monomer is selected from one or more of vinyl ether-tetramethylene glycol acrylate, vinyl ether-1,6-hexanediol diacrylate, vinyl ether diethylene glycol diacrylate, vinyl ether-2-phenoxyethyl acrylate, vinyl ether-2-phenoxyethyl acrylate, vinyl ether-dipropylene glycol diacrylate, and vinyl ether-pentaerythritol triacrylate.

13. The inkjet printing ink composition according to claim 1 or 2, characterized in that The inkjet printing ink composition further comprises 0.01-5 parts by weight of an auxiliary agent, wherein the auxiliary agent comprises fluorine-modified polysilane.

14. The inkjet printing ink composition according to claim 13, characterized in that The fluorine-modified polysiloxane includes polytrifluoropropylmethylsiloxane and organic fluorine polydimethylsiloxane.

15. An inkjet printing ink, characterized in that: The inkjet printing ink is prepared by mixing the inkjet printing ink composition according to any one of claims 1 to 14.

16. The inkjet printing ink according to claim 15, characterized in that The rotational viscosity of the inkjet printing ink at 25° C. is 3 mPa·s to 30 mPa·s.

17. An inkjet direct platemaking plate, wherein the inkjet direct platemaking plate is prepared by an inkjet direct platemaking process, characterized in that: The ink used in the inkjet direct platemaking process is the inkjet printing ink according to claim 15 or 16.

18. The inkjet direct-to-plate plate according to claim 17, characterized in that: The surface energy of the inkjet direct platemaking plate is 32 mN / m-36 mN / m.

19. The inkjet direct-to-plate plate according to claim 17, characterized in that: The cell depth of the inkjet direct platemaking plate is 10 μm-100 μm.

20. The inkjet direct-to-plate plate according to claim 19, characterized in that: The cell depth of the inkjet direct platemaking plate is 30 μm-60 μm.

21. The inkjet direct-to-plate plate according to any one of claims 17 to 20, characterized in that: The inkjet direct platemaking process includes using an inkjet printer to print the ink layer by layer onto a roller plate base or a flat plate base, and then photocuring to form a cell structure of the gravure plate to obtain a plate material.

22. The inkjet direct-to-plate plate according to claim 21, characterized in that: The light-curing molding adopts a UV-LED light source.

23. The inkjet direct-to-plate plate according to claim 22, characterized in that: The wavelength of the UV-LED light source is between 365nm and 410nm.

24. The inkjet direct-to-plate plate according to claim 22, characterized in that: The illumination intensity of the UV-LED light source is greater than 6W / cm 2 .

25. The inkjet direct-to-plate plate according to claim 23, characterized in that: The illumination intensity of the UV-LED light source is greater than 6W / cm 2 .

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