A soft uv ink resistant to dry and wet rubbing, and a preparation method and application thereof

Abstract

The application belongs to the technical field of ink, and provides a soft UV ink resistant to dry and wet rubbing, a preparation method and application thereof. The application adopts a monofunctional monomer, a photoinitiator and a color paste as main components of the soft UV ink, wherein the monofunctional monomer includes a monomer A and a monomer B, the monomer A can be cured under light energy ≤0.5 J / cm 2 The monomer B can be cured under light energy ≤1.5 J / cm 2 The mass of the monomer A accounts for more than 50% of the total mass of the monofunctional monomer, the photoinitiator includes a photoinitiator A and a photoinitiator B, the photoinitiator A is selected from a Norrish Type II intramolecular hydrogen abstraction photoinitiator and / or an amine synergist, the photoinitiator B is selected from a Norrish Type I radical cleavage photoinitiator, and the mass of the photoinitiator A accounts for more than 40% of the total mass of the photoinitiator. The application improves the problem of tackiness of the coating surface, the coating surface dries well, is resistant to dry and wet rubbing, has good folding resistance, excellent ductility, and strong adhesion.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ink, more particularly, to a soft UV ink resistant to dry and wet wiping and a preparation method and application thereof. BACKGROUND

[0002] UV inkjet printing has the advantages of strong digital editing capability, high efficiency, high resolution and low cost, and the UV ink used has the advantages of no solvent volatilization, energy saving and carbon reduction, and green environmental protection, and is more and more favored by people. The drying of UV ink is a photochemical curing process, and the UV light energy is absorbed by the photoinitiator in the UV ink to form free radicals and monomers or oligomers to polymerize into solid macromolecules. However, the photoinitiator and reaction monomers in the ink cannot completely participate in the reaction, especially the surface layer is interfered by oxygen, which is easy to cause oxygen inhibition problem, which will inhibit the reaction of photoinitiator and monomer, causing the surface not to dry, sticky and poor pigment fixation of surface layer, resulting in defects such as not resistant to dry and wet wiping of coating. Especially when printing on the surface of wallpaper, car stickers, advertising posters, light boxes and other substrates which need to be cleaned and wiped, the color loss caused by wiping the coating will not only affect the appearance, but also pollute the substrate and cause dyeing problems.

[0003] Oxygen inhibition refers to the reaction of oxygen in the coating with the photoinitiator, which hinders the normal reaction of the photoinitiator and the monomer. Oxygen inhibition seriously affects the efficiency of ink photo-curing. This problem has a relatively slight impact on hard ink, because hard ink uses multi-functional monomers, which can compete with oxygen for reaction, so the impact of oxygen inhibition is small. However, soft ink is used for printing soft materials such as soft film, canvas, EVA and leather, which requires the printed coating to have stretchability and not easy to crack, so the folding resistance of the coating also needs to be considered, so most soft inks use monofunctional monomers, which have a slower reaction speed, so the problem of oxygen inhibition is serious.

[0004] Therefore, it is urgent to develop a soft UV ink which not only ensures good folding resistance of the coating, but also inhibits the poor coating caused by oxygen inhibition, and further improves the problem of not resistant to dry and wet wiping. SUMMARY

[0005] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides a soft UV ink resistant to dry and wet wiping and a preparation method and application thereof. The soft UV ink provided by the present application has good surface drying, is resistant to dry and wet wiping (dry wiping can reach level 5, wet wiping can reach level 4-5), and has good folding resistance (no cracking in folding resistance test).

[0006] The first aspect of the present application provides a soft UV ink resistant to dry and wet wiping.

[0007] Specifically, a soft UV ink resistant to dry and wet wiping comprises the following components:

[0008] monofunctional monomer, photoinitiator, color paste;

[0009] The monofunctional monomer comprises monomer A and monomer B;

[0010] The monomer A is a monomer capable of being cured at light energy ≤0.5 J / cm 2 The monomer B is a monomer capable of being cured at light energy >0.5 J / cm 2 and ≤1.5 J / cm 2 The monomer B is a monomer capable of being cured at light energy >0.5 J / cm

[0011] The mass of the monomer A accounts for more than 50% of the total mass of the monofunctional monomer;

[0012] The photoinitiator comprises photoinitiator A and photoinitiator B;

[0013] The photoinitiator A is a Norrish type II intramolecular hydrogen abstraction photoinitiator and / or an amine synergist; and the photoinitiator B is a Norrish type I radical cleavage photoinitiator;

[0014] The mass of the photoinitiator A accounts for more than 40% of the total mass of the photoinitiator.

[0015] The monomer A used in the present application is a monofunctional monomer capable of being cured at low energy, and the curing energy requirement is low, and the monomer A can be cured at light energy ≤0.5 J / cm 2 , so that the effective photocuring can still be carried out under the interference of oxygen inhibition. Compared with the monomer A capable of being cured at low energy, the monomer B belongs to a monomer capable of being cured at sub-low energy, and the monomer B can be cured at light energy >0.5 J / cm 2 and ≤1.5 J / cm 2 . The present application uses the monomer A capable of being cured at low energy and accounting for more than 50% of the total mass of the monofunctional monomer, so that the photocuring reaction can be rapidly carried out, the influence of oxygen inhibition is reduced, and the monomer B capable of being cured at sub-low energy is further added to cooperate with the monomer A, so that the adhesion, folding resistance and ductility of the ink are improved, and the cost of the ink is controlled. In addition, the present application uses the photoinitiator A accounting for more than 40% of the total mass of the photoinitiator, and the photoinitiator A is almost not affected by oxygen inhibition, so that the photocuring rate is effectively accelerated, the oxygen inhibition is avoided due to the slow curing rate, the problem of sticky surface and poor dry and wet wiping resistance of the coating is improved. The present application controls the adding proportion of the monomer A and the photoinitiator A, effectively accelerates the curing rate, avoids the oxygen inhibition, improves the problems of sticky surface and poor dry and wet wiping resistance of the coating, controls the cost, and makes the performance of the coating reach the best.

[0016] The “surface drying” refers to the drying of the surface of the coating.

[0017] The "monofunctional monomer" means that each monomer molecule contains only one group that can participate in the photocuring reaction.

[0018] Preferably, the monomer A is a monomer that can be cured at a light energy of ≤ 0.3 J / cm 2 The cured monofunctional monomer.

[0019] Further preferably, the monomer A is a monomer that can be cured at a light energy of ≤ 0.2 J / cm 2 The cured monofunctional monomer.

[0020] If the monomer A curing energy is greater than 0.5 J / cm 2 , it will be interfered by oxygen inhibition; if the monomer A curing energy is less than 0.2 J / cm 2 , the reactivity is too high, it is not easy to store, and the price is high.

[0021] Preferably, the monomer A includes at least one of N,N-dimethyl acrylamide (No. DMAA), N-acryloyl morpholine (No. ACMO), N-vinyl pyrrolidone (No. NVP), o-phenylphenoxyethyl acrylate (No. OPPEA), 4 (ethoxy) nonyl phenol acrylate (No. 4EONPA), 2-vinyl oxy ethoxy acrylate ethyl ester (No. VEEA), N-vinyl caprolactam (No. NVC), trimethylol cyclohexyl acrylate (No. TMCHA), 4-tert-butyl cyclohexyl acrylate (No. TBCHA), hydroxyethyl acrylamide (No. HEAA), dicyclopentenyl acrylate (No. DCPA), 3-phenoxy benzyl acrylate (No. BPA), 2- (1,2-cyclohexane dicarboxy imine) ethyl acrylate (No. CHDCIEA).

[0022] Preferably, the monomer B is a monomer that can be cured at a light energy of > 0.5 J / cm 2 and ≤ 1.0 J / cm 2 The cured monofunctional monomer.

[0023] Further preferably, the monomer B is a monomer that can be cured at a light energy of > 0.5 J / cm 2 and ≤ 0.6 J / cm 2 The cured monofunctional monomer.

[0024] The monomer B of the second-lowest energy curing will be interfered by oxygen inhibition to a certain extent, but it has better functionality such as adhesion, folding resistance and ductility, and it can be selected from a variety of types and has low cost, so it is still selected. If the monomer B curing energy is greater than 1.5 J / cm 2 , it will be seriously interfered by oxygen inhibition; if the monomer B curing energy is less than 0.5 J / cm 2 , the cost will be significantly increased.

[0025] Preferably, the monomer B comprises at least one of tetrahydrofurfuryl acrylate (No. THFA), hydroxyethyl acrylate (No. HEA), hydroxypropyl acrylate (No. HPA), hydroxybutyl acrylate (No. HBA), methyl acrylate (No. MA), ethyl acrylate (No. EA), propyl acrylate (No. PA), butyl acrylate (No. BA), isooctyl acrylate (No. IOA), phenoxyethyl acrylate (No. PHEA), poly(ethylene glycol) phenyl ether acrylate (No. EO-PHEA), cyclo-trihydroxymethylpropane formal acrylate (No. CTFA), benzyl acrylate (No. BZA), ethoxyethoxyethyl acrylate (No. EOEOEA), isobornyl acrylate (No. IBOA), dicyclopentenyl (ethoxy) acrylate (No. EO-DCPA), caprolactone acrylate (No. CA).

[0026] Preferably, the photoinitiator A is a Norrish Type II intramolecular hydrogen abstraction type photoinitiator, or the photoinitiator A is a combination of a Norrish Type II intramolecular hydrogen abstraction type photoinitiator and an amine synergist.

[0027] Preferably, the mass ratio of the Norrish Type II intramolecular hydrogen abstraction type photoinitiator and the amine synergist is 1:(0.5-6).

[0028] Further preferably, the mass ratio of the Norrish Type II intramolecular hydrogen abstraction type photoinitiator and the amine synergist is 1:(0.7-4).

[0029] More preferably, the mass ratio of the Norrish Type II intramolecular hydrogen abstraction type photoinitiator and the amine synergist is 1:(1-2).

[0030] Preferably, the Norrish Type II intramolecular hydrogen abstraction type photoinitiator comprises at least one of benzophenone type photoinitiators and / or heterocyclic aromatic ketone type photoinitiators.

[0031] Preferably, the heterocyclic aromatic ketone type photoinitiator comprises at least one of thioxanthone type photoinitiators and / or anthraquinone type photoinitiators.

[0032] Preferably, the Norrish Type II intramolecular hydrogen abstraction type photoinitiator comprises at least one of Michler's ketone (No. MK), tetraethyl Michler's ketone (No. DEMK), methylethyl Michler's ketone (No. MEMK), 2,4-diethylthioxanthone (No. DETX), 2-isopropylthioxanthone (No. ITX), 2-chlorothioxanthone (No. CTX), and 1-chloro-4-propoxythioxanthone (No. CPTX).

[0033] Preferably, the amine synergist comprises a tertiary amine compound.

[0034] Preferably, the tertiary amine compound includes at least one of aliphatic tertiary amine, ethanolamine tertiary amine, benzoate tertiary amine, active amine (acrylamide), acrylate tertiary amine.

[0035] Further preferably, the amine synergist includes at least one of triethanolamine, triisopropanolamine, N-methyldiethanolamine, N-methylethanolamine, N,N-dimethylethanolamine, N,N-diethylethanolamine, 4-dimethylaminobenzoic acid ethyl ester (No. EDB), 4-dimethylaminobenzoic acid (2-ethyl)hexyl ester (No. EHA), isopentyl p-dimethylaminobenzoate (No. IADB), dimethylaminoethyl benzoate (No. DMB), N,N-dimethylaminobenzamide, acrylate amine.

[0036] Preferably, the photoinitiator B includes at least one of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (No. 819), 2,4,6-trimethylbenzoyldiphenylphosphine oxide (No. TPO), 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone (No. 369), 2-(4-methylbenzyl)-2-(dimethylamino)-1-(4-morpholinophenyl)-1-butanone (No. 379), and 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone (No. 907), hydroxycyclohexyl phenyl ketone (No. 184), 2-hydroxy-2-methyl-1-phenyl-1-propanone (No. 1173), 1,1'-(methylenedi-4,1-phenylene)bis[2-hydroxy-2-methyl-1-propanone] (No. 127).

[0037] Preferably, the dry and wet rub-resistant soft UV ink includes the following components in terms of mass parts:

[0038] monofunctional monomer 30-150 parts,

[0039] photoinitiator 4-30 parts,

[0040] color paste 10-40 parts.

[0041] Further preferably, the dry and wet rub-resistant soft UV ink includes the following components in terms of mass parts:

[0042] monofunctional monomer 50-100 parts,

[0043] photoinitiator 8-20 parts,

[0044] color paste 20-30 parts.

[0045] Preferably, the soft UV ink further includes an auxiliary agent including at least one of a wetting agent, a stabilizer, an adhesion promoter.

[0046] Preferably, the dry and wet erasable soft UV ink further comprises an auxiliary agent 0.1-10 parts by mass.

[0047] Further preferably, the dry and wet erasable soft UV ink further comprises an auxiliary agent 0.5-5 parts by mass.

[0048] Preferably, the mass of the monomer A accounts for more than 55% of the total mass of the monofunctional monomers.

[0049] Further preferably, the mass of the monomer A accounts for more than 60% of the total mass of the monofunctional monomers.

[0050] More preferably, the mass of the monomer A accounts for more than 65% of the total mass of the monofunctional monomers.

[0051] More preferably, the mass of the monomer A accounts for more than 70% of the total mass of the monofunctional monomers.

[0052] More preferably, the mass of the monomer A accounts for more than 75% of the total mass of the monofunctional monomers.

[0053] More preferably, the mass of the monomer A accounts for more than 80% of the total mass of the monofunctional monomers.

[0054] More preferably, the mass of the monomer A accounts for more than 85% of the total mass of the monofunctional monomers.

[0055] More preferably, the mass of the monomer A accounts for more than 90% of the total mass of the monofunctional monomers.

[0056] When the amount of the monomer A is too small, it is not enough to inhibit the interference of oxygen inhibition, and it is easy to make the surface sticky and not resistant to dry and wet erasing; when the amount of the monomer A is too large, the stability of the ink will be poor (high reactivity) and the cost will be high.

[0057] Preferably, the mass of the photoinitiator A accounts for more than 50% of the total mass of the photoinitiators.

[0058] Further preferably, the mass of the photoinitiator A accounts for more than 60% of the total mass of the photoinitiators.

[0059] More preferably, the mass of the photoinitiator A accounts for more than 65% of the total mass of the photoinitiators.

[0060] More preferably, the mass of the photoinitiator A accounts for more than 70% of the total mass of the photoinitiators.

[0061] More preferably, the mass of the photoinitiator A accounts for more than 75% of the total mass of the photoinitiators.

[0062] More preferably, the mass of the photoinitiator A accounts for more than 80% of the total mass of the photoinitiators.

[0063] When the amount of the photoinitiator A is too small, it is not enough to avoid the interference of oxygen inhibition on the light curing of the ink, and the surface layer is prone to stickiness and poor dry-wet rub resistance; when the amount of the photoinitiator A is too large, the ink is prone to yellowing and poor deep curing.

[0064] Preferably, the wetting agent is at least one of BYK-371, BYK-377, BYK-378, BYK-337, BYK-3500, BYK-3505, and BYK-361.

[0065] Preferably, the stabilizer is at least one of 2,6-di-tert-butyl-4-methylphenol (No. BHT), 4-methoxyphenol (No. MEHQ), RAHN GENORAD 16, RAHN GENORAD 18, RAHN GENORAD 20, RAHN GENORAD 22, RAHN GENORAD 23, Cyanox S100, Cyanox 110, Cyanox 210, and Cyanox 130.

[0066] Preferably, the adhesion promoter is at least one of polyester resin, polyurethane resin, epoxy resin, chlorovinyl resin, rosin resin, acrylate resin, aldehyde ketone resin, maleic acid resin, and polyvinyl butyral resin.

[0067] Preferably, the color paste comprises the following components: color paste monomer, dispersant, pigment, and stabilizer.

[0068] Preferably, the mass ratio of the color paste monomer, dispersant, pigment, and stabilizer is 40-90:5-30:10-50:0.1-5.0.

[0069] Further preferably, the mass ratio of the color paste monomer, dispersant, pigment, and stabilizer is 50-80:10-25:12-40:0.2-3.

[0070] More preferably, the mass ratio of the color paste monomer, dispersant, pigment, and stabilizer is 60-70:15-20:15-30:0.3-1.

[0071] Preferably, the color paste monomer comprises at least one of tetrahydrofurfuryl acrylate, cyclotrimethylolpropane formal acrylate, trimethylolcyclohexyl acrylate, phenoxyethyl acrylate, benzyl acrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, diethylene glycol diacrylate, propoxylated neopentyl glycol diacrylate, ethoxylated bisphenol A diacrylate, and ethoxylated trimethylolpropane triacrylate.

[0072] Preferably, the dispersant includes at least one of Evonik Dispers 710, Evonik Dispers 685, Evonik Dispers 655, BYK-168, BYK-9130, BYK-9131, BYK-9132, BYK-9150, BYK-9151, BYK-9152, BYK-2100, BYK-2200, BYK-2205, Solsperse 24000, Solsperse 32000, Solsperse 32500, Solsperse 36000, Solsperse 39000, EFKA 4310, EFKA 4330, EFKA 4030, EFKA 4701.

[0073] Preferably, the pigment includes at least one of a blue pigment, a yellow pigment, a red pigment, a black pigment, a white pigment.

[0074] Preferably, the blue pigment includes at least one of PB15:1, PB15:2, PB15:3, PB15:4.

[0075] Preferably, the yellow pigment includes at least one of PY138, PY150, PY151, PY155, PY168, PY180, PY183, PY185, PY194.

[0076] Preferably, the red pigment includes at least one of PV19, PR122, PR146, PR254, PR269.

[0077] Preferably, the black pigment includes carbon black.

[0078] Preferably, the white pigment includes titanium dioxide.

[0079] A second aspect of the present application provides a preparation method of a dry and wet rub-resistant soft UV ink.

[0080] A preparation method of a dry and wet rub-resistant soft UV ink, comprising the following steps:

[0081] Mixing the components to obtain the dry and wet rub-resistant soft UV ink.

[0082] Preferably, the monofunctional monomer and the photoinitiator are mixed and dissolved to obtain a pre-solution, and then the pre-solution and the color paste are mixed, and the solid-liquid separation is performed, and the obtained liquid is the soft UV ink.

[0083] Preferably, the mixing of the monofunctional monomer, the photoinitiator and the auxiliary agent is performed simultaneously.

[0084] Preferably, the mixing of the pre-solution and the color paste is performed by stirring at a speed of 500-1500 rpm for 1-12 h.

[0085] Further preferably, the stirring is performed at a speed of 800-1300 rpm for 3-10 h.

[0086] More preferably, the stirring is performed at a speed of 1000-1200 rpm for 5-8 h.

[0087] Preferably, the solid-liquid separation is performed by filtration, which includes sequentially performing primary filtration and secondary filtration.

[0088] Preferably, the primary filtration is performed by using a filter membrane with a pore size of 0.1-1 μm.

[0089] Further preferably, the primary filtration is performed by using a filter membrane with a pore size of 0.5-0.7 μm.

[0090] Preferably, the primary filtration is performed by using a glass fiber filter membrane.

[0091] Preferably, the secondary filtration is performed by using a filter membrane with a pore size of 0.1-0.8 μm.

[0092] Further preferably, the secondary filtration is performed by using a filter membrane with a pore size of 0.3-0.5 μm.

[0093] Preferably, the secondary filtration is performed by using a polypropylene (PP) filter membrane.

[0094] The third aspect of the present application provides an application of the dry and wet rub-resistant soft UV ink.

[0095] The application of the dry and wet rub-resistant soft UV ink in printing soft materials.

[0096] Compared with the prior art, the present application has the following advantages:

[0097] The present application uses monofunctional monomer, photoinitiator and color paste as the main components of the soft UV ink, wherein the monofunctional monomer includes specific proportions of monomers that can be polymerized under light energy ≤0.5 J / cm 2 The cured monomer A and monomers that can be polymerized under light energy ≤1.5 J / cm 2The cured monomer B, the mass of monomer A accounts for more than 50% of the total mass of monofunctional monomers, the photoinitiator includes photoinitiator A and photoinitiator B, the photoinitiator A is selected from the Norrish Type II intramolecular hydrogen abstraction photoinitiator and / or amine synergist, the photoinitiator B is selected from the Norrish Type I radical cleavage photoinitiator, the mass of photoinitiator A accounts for more than 40% of the total mass of photoinitiators, and the application cooperates different types of monofunctional monomers and different types of photoinitiators, controls the ratio, accelerates the photocuring speed, avoids the influence of oxygen inhibition during photocuring, improves the problem of tackiness of the coating surface, makes the coating surface dry well, resists dry and wet wiping (dry wiping can reach level 5, wet wiping can reach level 4-5), has good folding resistance (no cracking in the folding resistance test), has excellent ductility (elongation is not less than 123.3%), has strong adhesion (adhesion reaches level 0-1), and controls the cost at the same time. DETAILED DESCRIPTION

[0098] In order to make the skilled in the art more clearly understand the technical solutions described in the application, the following examples are listed for illustration. It should be pointed out that the following examples do not constitute a limitation on the scope of protection required by the application.

[0099] The raw materials, reagents or devices used in the following examples, unless otherwise specified, can be obtained from conventional commercial channels or can be obtained by existing known methods.

[0100] The "polyfunctional monomer" refers to each monomer molecule containing two or more groups that can participate in photocuring reaction.

[0101] Example 1

[0102] A dry and wet wiping resistant soft UV ink includes the components shown in Table 1.

[0103] The preparation method of the above-mentioned dry and wet wiping resistant soft UV ink includes the following steps:

[0104] (1) After monomer A (CHDCIEA, NVC, DCPA), monomer B (IBOA and BZA), photoinitiator A (DETX, EDB), photoinitiator B (TPO, 369), wetting agent BYK-361 and stabilizer MEHQ are mixed and dissolved, a pre-solution is obtained;

[0105] (2) Then the pre-solution is mixed with the color paste, and stirred at a stirring speed of 1000 rpm; wherein the color paste includes color paste monomers PHEA and THFA, dispersant Solsperse 24000 and red pigment. Then it is filtered through 0.7 μm glass fiber filter membrane and 0.5 μm PP filter membrane in sequence to obtain the dry and wet wiping resistant ink.

[0106] Examples 2-5

[0107] Examples 2-5 provide soft UV inks that are resistant to dry and wet rub, with the difference from Example 1 being the components and their amounts. The specific components are shown in Table 1.

[0108] Comparative Examples 1-5

[0109] Comparative Examples 1-5 provide soft UV inks, with the difference from Example 1 being the components and their amounts. The specific components are shown in Table 1.

[0110] Table 1 Components and their amounts (mass parts) of soft UV inks of each example and comparative example

[0111]

[0112]

[0113] Product effect test

[0114] A domestic wide-format printer was used, equipped with an LED-UV curing lamp with a wavelength of 395 nm, using an Epson fifth-generation industrial printhead MH5420, and the soft UV inks provided by each example and each comparative example were used to print sample sheets. The printed sample sheet specifications were a solid color long strip block of 16 cm x 10 cm, and then cut according to the required sample size. Dry and wet wiping tests, adhesion tests, folding resistance tests, and elongation tests were performed. Among them, the substrates for dry and wet wiping tests were PVC soft film and acrylic plate, the substrates for folding resistance and elongation tests were PVC soft film, and the substrates for adhesion tests were acrylic plate.

[0115] (1) Dry and wet wiping test: a rubbing fastness tester was used, and the test standard of national standard GBT 3920-2008 was used, with 5 being the best and 1 being the worst.

[0116] (2) Adhesion test using grid test: the test standard of national standard GBT 9286-1998 was used, with 0 being the best and 5 being the worst.

[0117] (3) Folding resistance test: the ink coating of the cross-shaped crease was observed for cracking after two folds and 1 min of pressing.

[0118] (4) Elongation test: a tensile tester was used, and the test standard of industry standard HGT 4991-2016 was used, with elongation = (total length after stretching - sample length) / sample length.

[0119] The test results are shown in Table 2.

[0120] Table 2 Performance test results of soft UV inks of each example and each comparative example

[0121]

[0122] From the above table, it can be seen that the soft UV ink provided by the embodiments 1-5 of the present application has fast curing rate, good dry to touch, the obtained coating has good dry and wet rub resistance, good folding resistance, good ductility, and the adhesion test reaches 0-1 level. By regulating the types of monofunctional monomer and photoinitiator and their addition ratio, the present application can maximize the reduction of the influence of oxygen inhibition and improve the dry and wet rub resistance of the coating.

[0123] The mass of monomer A in Comparative Example 1 accounts for less than 50% of the total mass of monofunctional monomers, and the mass of photoinitiator A accounts for less than 40% of the total mass of photoinitiators, so the ink coating is not resistant to dry and wet rubbing. The mass of photoinitiator A in Comparative Example 2 accounts for less than 40% of the total mass of photoinitiators, resulting in the ink coating not being resistant to dry and wet rubbing. The mass of monomer A in Comparative Example 3 accounts for less than 50% of the total mass of monofunctional monomers, resulting in the ink coating not being resistant to dry and wet rubbing. Comparative Example 4 adds a multi-functional monomer with fast reaction rate, resulting in the coating having decreased adhesion, folding resistance, ductility and other functions. Comparative Example 5 contains only monomer A and no monomer B, resulting in poor adhesion and increased cost.

Claims

1. A soft UV ink resistant to both dry and wet rubbing, characterized in that, It consists of the following components: Monofunctional monomers, photoinitiators, color pastes; The monofunctional monomers include monomer A and monomer B; The monomer A is available in light energy ≤ 0.5 J / cm². 2 The solidified monofunctional monomer, wherein monomer B is capable of operating at light energy > 0.5 J / cm². 2 And ≤1.5J / cm 2 Solidified monofunctional monomer; The mass of monomer A accounts for more than 55% of the total mass of the monofunctional monomer; The photoinitiator includes photoinitiator A and photoinitiator B; The photoinitiator A is a Norrish type II intramolecular hydrogen abstraction photoinitiator and / or an amine synergist; the photoinitiator B is a Norrish type I free radical cleavage photoinitiator; The mass of photoinitiator A accounts for more than 40% of the total mass of the photoinitiator; The monomer A comprises at least one of N,N-dimethylacrylamide, N-acryloylmorpholine, N-vinylpyrrolidone, o-phenylphenoxyethyl acrylate, 4-(ethoxy)nonylphenol acrylate, 2-vinyloxyethoxyethyl acrylate, N-vinylcaprolactam, trimethylolcyclohexyl acrylate, 4-tert-butylcyclohexyl acrylate, hydroxyethylacrylamide, dicyclopentenyl acrylate, 3-phenoxybenzyl acrylate, and 2-(1,2-cyclohexanedicarboxyimino)ethyl acrylate; The monomer B includes at least one of tetrahydrofuran acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, isooctyl acrylate, phenoxyethyl acrylate, cyclotrimethylolpropane formal acrylate, benzyl acrylate, ethoxyethoxyethyl acrylate, isobornyl acrylate, dicyclopentenylethoxyacrylate, and caprolactone acrylate.

2. The flexible UV ink according to claim 1, characterized in that, The photoinitiator A is a Norrish type II intramolecular hydrogen-abstraction photoinitiator, or the photoinitiator A is a combination of a Norrish type II intramolecular hydrogen-abstraction photoinitiator and an amine synergist.

3. The soft UV ink according to claim 1, characterized in that, The photoinitiator B comprises at least one of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone, 2-(4-methylbenzyl)-2-(dimethylamino)-1-(4-morpholinophenyl)-1-butanone, 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, hydroxycyclohexylbenzophenone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, and 1,1'-(methylenedi-4,1-phenylene)bis[2-hydroxy-2-methyl-1-propanone].

4. The soft UV ink according to claim 1, characterized in that, Based on parts by weight, it includes the following components: 30-150 units of monofunctional monomers 4-30 parts of photoinitiator 10-40 parts of color paste.

5. The soft UV ink according to claim 1, characterized in that, The flexible UV ink also includes additives, which include at least one of wetting agents, stabilizers, and adhesion promoters.

6. A method for preparing the dry and wet rub resistant soft UV ink according to any one of claims 1-5, characterized in that, Includes the following steps: The components are mixed to obtain the soft UV ink that is resistant to both dry and wet rubbing.

7. The preparation method according to claim 6, characterized in that, First, the monofunctional monomer and photoinitiator are mixed and dissolved to obtain a presol. Then, the presol and pigment are mixed, and the solid and liquid are separated. The resulting liquid is a soft UV ink.

8. The use of the soft UV ink according to any one of claims 1-5 in printing soft materials.

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