Cationic photocurable composition and use thereof

Abstract

The present invention provides a cationic photocurable composition and use thereof. The composition comprises, by weight, 10-30 parts of a first cationic polymerizable compound, 10-65 parts of a second cationic polymerizable compound, 20-60 parts of an epoxy compound and / or an oxetane compound, 1-10 parts of a cationic initiator, and 2-20 parts of a pigment, and the first cationic polymerizable compound and the second cationic polymerizable compound have structures represented by structural formula I and structural formula II, TIFF2025515395000023.tif38170 [In the formula, R0 is selected from hydrogen, a methyl group, and an ethyl group. R1 represents a methyl group or an ethyl group. n is 1 or 2. R2 represents a methyl group or an ethyl group.] The total content of the first cationic polymerizable compound and the second cationic polymerizable compound is 30wt% to 75wt% based on the total amount of the cationic photocurable composition. The composition can improve the dot density change after ink application, improve the optical density, and has good adhesion and a fast curing speed.

Description

[Technical field]

[0001] The present invention relates to the field of photocuring technology, specifically to a cationic photocurable composition and its use. [Background technology]

[0002] In recent years, inkjet printing has been widely applied in the printing field such as electronic devices, display devices, color filters, and business printing because it can easily and inexpensively produce images. Commonly used inkjet inks mainly include three types: aqueous inkjet inks, solvent-based inkjet inks, and active energy ray-curable inkjet inks. Among them, active energy ray-curable inkjet inks are widely applied because they can rapidly form a desired pattern in a non-contact manner and are applicable to printing on various recording media.

[0003] In inkjet printing, the ink ejected from the nozzles of the inkjet head falls onto the substrate and then spreads to a certain size to form dots. If the dot density is small, the ink cannot cover the substrate surface and leaves blank areas, resulting in a low OD value (optical density) and a failure to obtain a high-definition printing pattern.

[0004] To solve this problem, many improvements have been made by focusing on pigments to improve OD value (optical density), or by improving image resolution or increasing the amount of ink per point, but as the concentration of pigments increases, the stability of the composition decreases, and when the size of the droplets is reduced to improve image quality, the sensitivity decreases obviously, and when the amount of ink per point is increased, the phenomenon of penetration is easily generated.In addition, it is difficult to achieve the OD value required for the product by adjusting the interval between inkjet ink droplets, and the operability is poor.

[0005] Active energy ray curable inkjet inks mainly include two types: radically polymerizable inkjet inks using vinyl compounds, and cationic polymerizable inkjet inks using epoxy compounds and vinyl ether compounds. Radical polymerizable inkjet inks are widely used in practice because of the wide range of materials available, but are significantly affected by oxygen inhibition, resulting in insufficient ink curing, and when forming an image on a non-absorbent substrate, such as plastic, glass, metal, etc., bleeding occurs between uncured inks, resulting in deterioration of image quality. Cationic polymerizable inkjet inks are not inhibited by oxygen, but conventional cationic polymerizable inks are not affected by the type of recording material, particularly non-absorbent substrates, such as plastic, glass, metal, etc., and are prone to a decrease in dot density after deposition, resulting in a decrease in OD value (optical density), and high-definition images cannot be formed on any of a variety of recording materials. Improving the OD value of cationic inkjet inks is of great significance for improving the overall performance of inkjet printing. Summary of the Invention

[0006] The main object of the present invention is to provide a cationic photocurable composition and use thereof in order to solve the problem of low OD value of conventional cationic polymerizable inks.

[0007] In order to achieve the above object, according to one aspect of the present invention, there is provided a composition comprising, by weight, 10 to 30 parts of a first cationically polymerizable compound, 10 to 65 parts of a second cationically polymerizable compound, 20 to 60 parts of an epoxy compound and / or an oxetane compound, 1 to 10 parts of a cationic initiator, and 2 to 20 parts of a pigment, The first cationically polymerizable compound is any one or more of the compounds represented by structural formula I, and the second cationically polymerizable compound is any one or more of the compounds represented by structural formula II, TIFF2025515395000002.tif38170 [In the formula, R0 is any one selected from the group consisting of hydrogen, a methyl group, and an ethyl group. R1 represents a methyl group or an ethyl group. n is 1 or 2. R2 represents a methyl group or an ethyl group.] The cationic photocurable composition is provided in which the total content of the first cationic polymerizable compound and the second cationic polymerizable compound is 30 wt % to 75 wt % based on the total content of the cationic photocurable composition.

[0008] Furthermore, the first cationically polymerizable compound is TIFF2025515395000003.tif38170, Preferably, the second cationically polymerizable compound is The file is TIFF2025515395000004.tif15170.

[0009] Further, the epoxy compound may be 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate, bis(3,4-epoxycyclohexylmethyl)adipate, a caprolactone-modified compound of 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate, an ester compound or a caprolactone-modified compound of a polyvalent carboxylic acid and 3,4-epoxycyclohexylmethyl alcohol, a silicone compound having an alicyclic epoxy group at the terminal, a diglycidyl ether of bisphenol A, a diglycidyl ether of bisphenol F, a diglycidyl ether of brominated bisphenol A, a phenol novolac type epoxy resin, a cresol novolac type epoxy resin, a biphenyl, a terpolymer ... and the like. The epoxy resin composition according to the present invention includes one or more selected from the group consisting of phenyl-type epoxy resin, diglycidyl terephthalate, diglycidyl phthalate, an addition reaction product of polybutadiene having a carboxylic acid group at its terminal and bisphenol A-type epoxy resin, dicyclopentadiene dioxide, limonene dioxide, 4-vinylcyclohexene dioxide, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, epoxidized vegetable oil, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 3-glycidyloxypropyltrimethoxysilane, and 3-glycidyloxypropylmethyldimethoxysilane, And / or, the oxetane compound includes any one or more selected from the group consisting of 3-benzyloxymethyl-3-ethyloxetane, 3-ethyl-3-phenoxymethyloxetane, 3,3'-[2-(benzyloxy)propane-1,3-dimethoxydiethyloxetane], and 3-ethyl-3-methoxyoxetane methacrylate.

[0010] Further, the cationic initiator includes an iodonium salt and / or a sulfonium salt photoinitiator, and optionally the cationic initiator is any one or more selected from the group consisting of diaryliodonium salts of arsenic acid, diaryliodonium salts of sulfonic acid, triarylsulfonium salts of sulfonic acid, diaryliodonium salts of boric acid, triarylsulfonium salts of boric acid, diaryliodonium salts of phosphoric acid, triarylsulfonium salts of phosphoric acid, diaryliodonium salts of antimonic acid, and triarylsulfonium salts of antimonic acid.

[0011] Furthermore, the pigment is an organic pigment and / or an inorganic pigment, and the color of the pigment includes any one or more of black, blue, brown, blue-green, green, white, purple, magenta, red, orange, and yellow.

[0012] Furthermore, the cationic photocurable composition further comprises a sensitizer, Preferably, the content of the sensitizer is 0.1 wt% to 10 wt%, more preferably 3 wt% to 8 wt%, based on the cationic photocurable composition. Preferably, the sensitizer includes any one or more selected from the group consisting of thioxanthone compounds, xanthone compounds, acridine compounds, anthracene compounds, and coumarin compounds, and more preferably, the sensitizer is any one or more selected from the group consisting of anthracene compounds and thioxanthone compounds.

[0013] Furthermore, the total content of the first cationic polymerizable compound and the second cationic polymerizable compound is 30 wt% to 60 wt% based on the total content of the cationic photocurable composition, and the ratio of the amounts of the first cationic polymerizable compound and the second cationic polymerizable compound used is 1:5 to 3:1.

[0014] Furthermore, the cationic photocurable composition further contains an auxiliary, and the auxiliary contains any one or more of a leveling agent, a dispersant, a curing agent, a surfactant, an antifoaming agent, and a storage stabilizer.

[0015] Furthermore, the viscosity of the cationic photocurable composition is less than 50 mPa·s, and preferably the viscosity is from 2 to 30 mPa·s.

[0016] According to another aspect of the present invention, there is provided use of any of the above cationic photocurable compositions in an ink.

[0017] Furthermore, the substrate used by the ink includes any one of a film, glass, and plastic; Preferably, the ink jet thickness of the ink is 0.1 to 10 μm, more preferably 0.5 to 5 μm.

[0018] By applying the technical solution of the present invention, a cationic polymerizable compound having a specific structure is used in a specific ratio in combination with an epoxy compound and / or an oxetane compound, and the synergistic effect of the cationic polymerizable compound with the epoxy compound and / or the oxetane compound results in a cationic polymerizable composition that is less susceptible to the effects of humidity, effectively improves the change in dot density after ink deposition, improves the optical density, and can form high-definition images on any of a variety of recording materials. In addition, the composition has excellent adhesion and a fast curing speed, and when used as an ink, the application range of the cationic polymerizable ink can be effectively expanded. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] In addition, unless there is a contradiction, the embodiments and features in the embodiments in the present application may be combined with each other.

[0020] As analyzed in the background art of this application, in the prior art, the dot density of the cationic photocurable ink after application is easily reduced, causing a reduction in the OD value (optical density), and thus making it impossible to form high-definition images on various recording materials. To solve this problem, a cationic photocurable composition and use thereof are provided.

[0021] According to one exemplary embodiment of the present application, the composition includes, by weight, 10 to 30 parts of a first cationically polymerizable compound, 10 to 65 parts of a second cationically polymerizable compound, 20 to 60 parts of an epoxy compound and / or an oxetane compound, 1 to 10 parts of a cationic initiator, and 2 to 20 parts of a pigment; The first cationically polymerizable compound is any one or more of the compounds represented by structural formula I, and the second cationically polymerizable compound is any one or more of the compounds represented by structural formula II, TIFF2025515395000005.tif38170 [In the formula, R0 is any one selected from the group consisting of hydrogen, a methyl group, and an ethyl group. R1 represents a methyl group or an ethyl group. n is 1 or 2. R2 represents a methyl group or an ethyl group.] The cationic photocurable composition is provided in which the total content of the first cationic polymerizable compound and the second cationic polymerizable compound is 30 wt % to 75 wt % based on the total content of the cationic photocurable composition.

[0022] The present application relates to a method for producing a cationic polymerizable composition comprising: a) a cationic polymerizable compound having a specific structure and a specific ratio; b) an epoxy compound and / or an oxetane compound; c) a synergistic effect between the cationic polymerizable compound and the epoxy compound and / or the oxetane compound; d) the cationic polymerizable composition is less susceptible to the effects of humidity, effectively improves the change in dot density after ink deposition, improves the optical density, and is capable of forming high-definition images on any of a variety of recording materials; and e) the composition has excellent adhesion and a fast curing speed, and when used as an ink, can effectively expand the range of application of the cationic polymerizable ink.

[0023] In some preferred embodiments of the present application, the first cationically polymerizable compound is TIFF2025515395000006.tif38170, which is relatively easy to manufacture, and can better exert synergistic effects with the second cationically polymerizable compound, the epoxy compound and / or the oxetane compound, thereby further improving the optical density. Preferably, the second cationically polymerizable compound is TIFF2025515395000007.tif16170, and the effect on improving the performance of the composition, particularly the OD value and adhesion, is clear.

[0024] The cationic photocurable composition of the present application may contain both an epoxy compound and an oxetane compound, or may contain either one of them. The specific types of the epoxy compound and the oxetane compound may be selected from the conventional art, but are not limited thereto.

[0025] In some embodiments of the present application, the epoxy compound is 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, bis(3,4-epoxycyclohexylmethyl)adipate, a caprolactone-modified compound of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, an ester compound of a polyvalent carboxylic acid and 3,4-epoxycyclohexylmethyl alcohol or a caprolactone-modified compound, a silicone-based compound having an alicyclic epoxy group at a terminal, a diglycidyl ether of bisphenol A, a diglycidyl ether of bisphenol F, a diglycidyl ether of brominated bisphenol A, a phenol novolac-type epoxy resin, a cresol novolac-type epoxy resin. The epoxy resin may include one or more selected from the group consisting of epoxy resins, biphenyl type epoxy resins, diglycidyl terephthalate, diglycidyl phthalate, addition reaction products of polybutadiene having a carboxylic acid group at the end and bisphenol A type epoxy resins, dicyclopentadiene dioxide, limonene dioxide, 4-vinylcyclohexene dioxide, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, epoxidized vegetable oil, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 3-glycidyloxypropyltrimethoxysilane, and 3-glycidyloxypropylmethyldimethoxysilane.

[0026] In some embodiments of the present application, the oxetane compound includes one or more selected from the group consisting of 3-benzyloxymethyl-3-ethyloxetane, 3-ethyl-3-phenoxymethyloxetane, 3,3'-[2-(benzyloxy)propane-1,3-dimethoxydiethyloxetane], 3-ethyl-3-methoxyoxetane methacrylate, TCM series products manufactured by Kuraray, and THM series products. Preferably, the amount of the epoxy compound and / or the oxetane compound used in the cationic photocurable composition is 30 to 55 wt%, for example, 35 wt%, 40 wt%, 45 wt%, or 50 wt%, to further improve the curing and drying speed of the composition.

[0027] In some preferred embodiments of the present application, the content of the epoxy compound and / or oxetane compound is 30 wt % to 50 wt % based on the total amount of the cationic photocurable composition, and the printed pattern of the composition has a high OD value and is excellent in overall performance such as appearance.

[0028] The cationic initiator may be selected from the prior art, for example, the cationic initiator is selected from iodonium salt and / or sulfonium salt photoinitiators. In some embodiments of the present application, the cationic initiator is one or more selected from the group consisting of diaryliodonium salt of arsenic acid, diaryliodonium salt of sulfonic acid, triarylsulfonium salt of sulfonic acid, diaryliodonium salt of boric acid, triarylsulfonium salt of boric acid, diaryliodonium salt of phosphoric acid, triarylsulfonium salt of phosphoric acid, diaryliodonium salt of antimonic acid, and triarylsulfonium salt of antimonic acid, which can further improve the curing speed of the cationic photocurable composition.

[0029] For example, the cationic photoinitiator may be 4-phenylthiotriphenylsulfonium hexafluoroantimonate, 4-phenylthiotriphenylsulfonium hexafluorophosphate, 4-phenylthiotriphenylsulfonium camphorsulfonate, 4-phenylthiotriphenylsulfonium tetra(pentafluorophenyl)borate, thio-p-phenylenebis(4,4'-dimethyldiphenylsulfonium)bistetra(pentafluorophenyl)borate, tris(3-fluoro-4-methylphenyl)sulfonium hexafluorophosphate, 4,4'-dimethyldiphenyliodonium hexafluorophosphate, 4,4'- Dimethyldiphenyliodonium tetra(pentafluorophenyl)borate, bis(4-t-butylphenyl)iodonium hexafluorophosphate, bis(4-t-butylphenyl)iodonium hexafluoroantimonate, bis(4-t-butylphenyl)iodonium trifluoromethylsulfonate, diphenyliodonium hexafluorophosphate, 4-isopropyl-4'-methyldiphenyliodonium tetra(pentafluorophenyl)borate, (4-methyl-4'-isobutyl)diphenyliodonium hexafluorophosphate, bis(2,4,6-trimethylpyridine)iodonium hexafluorophosphate, thio-p-phenylenebis(4,4'-Dimethyldiphenylsulfonium)bishexafluoroantimonate, bis(dodecylphenyl)iodonium hexafluoroarsenate, bis(dodecylphenyl)iodonium hexafluoroantimonate, dialkylphenyliodonium hexafluoroantimonate, diaryliodonium salts of perfluoroalkylsulfonic acids, diaryliodonium salts of perfluorobutanesulfonic acids, diaryliodonium salts of perfluoroethanesulfonic acids, diaryliodonium salts of perfluorooctanesulfonic acids, diaryliodonium salts of trifluoromethanesulfonic acids, diaryliodonium salts of p-tolylsulfonic acids, diaryliodonium salts of dodecylbenzenesulfonic acids, diaryliodonium salts of benzenesulfonic acids The sulfonium salt may be any one or more selected from the group consisting of peraryl sulfonium salts, diaryliodonium salts of 3-nitrobenzenesulfonic acid, triarylsulfonium salts of perfluorobutanesulfonic acid, triarylsulfonium salts of perfluoroethanesulfonic acid, triarylsulfonium salts of perfluorooctane sulfonic acid, triarylsulfonium salts of trifluoromethanesulfonic acid, triarylsulfonium salts of p-tolylsulfonic acid, triarylsulfonium salts of dodecylbenzenesulfonic acid, triarylsulfonium salts of benzenesulfonic acid, triarylsulfonium salts of 3-nitrobenzenesulfonic acid, diaryliodonium salts of perhalogenated arylboronic acids, and triarylsulfonium salts of perhalogenated arylboronic acids.

[0030] In some preferred embodiments of the present application, the cationic initiator is any one selected from the group consisting of diaryliodonium salts of hexafluoroantimony acid and triarylsulfonium salts of hexafluoroantimony acid, which is advantageous in improving the OD value of the printed pattern and has excellent overall performance.

[0031] The pigment in the cationic photocurable composition is a colorant and may be selected from the prior art, may be an inorganic pigment or an organic pigment, and may be any color, such as black, blue, brown, turquoise, green, white, purple, magenta, red, orange, yellow, and mixtures thereof. For example, the organic pigment is any one or more selected from the group consisting of perylene, phlotacyanine dyes (e.g., phlotacyanine green, phlotacyanine blue), cyanine pigments (e.g., Cy3, Cy5, and Cy7), naphthalocyanine pigments, nitroso pigments, azo pigments, diazo pigments, diazo condensation pigments, basic dye pigments, alkali blue pigments, indigo pigments, phloxine pigments, quinacridone pigments, isoindolinone pigments, dioxazine pigments, carbazole dioxazine violet pigments, alizarin lake pigments, phthalamide pigments, carmine lake pigments, tetrachloroisoindolinone pigments, perinone pigments, anthraquinone pigments, and quinophthalone pigments. The inorganic pigment is at least one selected from the group consisting of oxides of titanium (e.g., titanium dioxide, conductive titanium dioxide), oxides of iron (e.g., red iron oxide, yellow iron oxide, black iron oxide, and transparent iron oxide), oxides of aluminum, oxides of silicon, carbon black pigments, metal sulfides, and metal chlorides.

[0032] In order to further improve the photosensitivity of the cationic photocurable composition, the cationic photocurable composition further comprises a sensitizer, the specific type and amount of the sensitizer can be determined based on the prior art, and in some embodiments of the present application, the content of the sensitizer is 0.1 wt% to 10 wt% relative to the cationic photocurable composition, preferably 3 wt% to 8 wt%, for example, 4 wt%, 5 wt%, 6 wt%, or 7 wt%, so that the cationic photocurable composition has excellent photosensitivity and overall performance.

[0033] In some embodiments of the present application, the sensitizer comprises one or more selected from the group consisting of thioxanthone compounds, xanthone compounds, acridine compounds, anthracene compounds and coumarin compounds. Preferably, the sensitizer is one or more selected from the group consisting of anthracene compounds and thioxanthone compounds, such as JRCure-1105 (ITX), JRCure-1106 (DETX) manufactured by Tianjin Jiuri New Materials Co., Ltd., and PSS303, PSS306, PSS510, PSS513, PSS515, PSS402, PSS403, PSS603, etc. manufactured by Changzhou Strong Electronic New Materials Co., Ltd., and by using it in combination with the cationic polymerizable compound of the present application, it has better photosensitivity and particularly excellent comprehensive performance.

[0034] In some embodiments of the present application, in order to further improve the OD value of the ink printing pattern and obtain a clearer pattern, the total content of the first cationic polymerizable compound and the second cationic polymerizable compound is 30 wt% to 60 wt%, for example, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, based on the total content of the cationic photocurable composition, and the ratio of the amount of the first cationic polymerizable compound to the second cationic polymerizable compound is 1:5 to 3:1, for example, 1:5, 1:4, 1:3, 1:2, 2:3, 1:1, 3:2, 2:1, 5:2, 3:1, or any range therebetween.

[0035] As an option depending on the usage environment of the product, the cationic photocurable composition of the present application may selectively contain one or more organic and / or inorganic auxiliaries commonly used in this field, such as a leveling agent, a dispersant, a curing agent, a surfactant, an antifoaming agent, and a storage stabilizer. For the specific components and amounts of the auxiliaries, reference may be made to the prior art, but the details will be omitted here.

[0036] The viscosity of the cationic photocurable composition of the present application is not particularly limited, and when the composition forms a coating layer by inkjet printing, the viscosity of the composition is usually 50 mPa s or less, and preferably 2 to 30 mPa s. The viscosity of the composition of the present invention can be well controlled during storage, and there is no need to add a thickener or thinning agent separately.

[0037] The cationic photocurable composition of the present application is not particularly limited in the form of the initiation energy source, and can undergo a polymerization reaction by irradiation with energy such as ultraviolet light, visible light, infrared light, an electron beam, a laser, etc., to achieve rapid curing. For example, the initiation energy source may be an actinic ray such as an ultra-high pressure mercury lamp, a high pressure mercury lamp, a medium pressure mercury lamp, a mercury-xenon lamp, a low pressure mercury lamp, a metal halide lamp, a xenon lamp, a deuterium lamp, a chemical lamp, an LED lamp, a fluorescent lamp, a tungsten lamp, an Nd-YAG triple harmonic laser, a He-Cd laser, a nitrogen laser, a Xe-Cl excimer laser, a Xe-F excimer laser, a semiconductor pumped solid-state laser, an i-ray, an h-ray, or a g-ray, having a wavelength of 200 to 500 nm. The composition may be cured by energy such as electron beam, α-ray, β-ray, γ-ray, X-ray, and neutron beam. Preferably, a mercury lamp, an ultraviolet lamp, or a UV-LED lamp having a wavelength range of 200 to 500 nm may be used, and the irradiation energy is preferably 20 to 1000 mJ / cm. 2 When cured with a longer wavelength energy source, a sensitizer is preferably added to the composition to increase the photosensitivity of the composition.

[0038] The components in the cationic photocurable composition of the present application are uniformly mixed to obtain an active energy ray curable inkjet ink, and the specific manufacturing process may refer to the conventional manufacturing process for photocurable compositions. Typically, the manufacturing process includes blending, pre-dispersion, grinding, and filtration (filtering through a screen mesh of a predetermined size to obtain a product having a desired particle size) under conditions of constant temperature and humidity and shielding of the irradiation light source to obtain an inkjet ink.

[0039] According to another exemplary embodiment of the present application, there is provided a use of any one of the above cationic photocurable compositions in an ink.

[0040] The use of the above cationic photocurable composition as an ink can well solve the problem of low OD value of the printed pattern, realize high-precision inkjet printing, and has excellent curing performance, especially the curing speed is obviously improved, and has good application prospects.

[0041] When the cationic photocurable composition is used as an ink, the application method thereof may refer to the conventional art and is not particularly limited. In addition to the inkjet printing method, other well-known methods such as a dipping method, an air knife coating method, a curtain coating method, a roll coating method, a die coating method, and a wire bar coating method may be adopted.

[0042] When the cationic photocurable composition is used as an ink, the substrate to be used is not particularly limited, and may be, for example, any one of a film, glass, and plastic. Depending on the material of the substrate selected, a surface treatment, such as a corona treatment, may be selectively performed.

[0043] The thickness of the cured coating layer of the pattern ink-jetted with the cationic photocurable composition of the present application can be adjusted according to the prior art or the purpose of use, and preferably, the thickness of the ink-jetted pattern is 0.1-10 μm, and particularly preferably, 0.5-5 μm, so that the formed coating layer is relatively uniform and advantageous for cost control. If the thickness of the ink coating layer is too small, the coating layer may not be formed uniformly or may be difficult to print accurately according to the design, and if the thickness is too large, the coating layer may consume a large amount of printing ink, causing an increase in costs, and may be disadvantageous to uniform application, and the coating layer may be brittle and easily separated.

[0044] The beneficial effects of the present invention will be further described below with reference to examples and comparative examples.

[0045] 1. Ink Preparation According to the formulations of the Examples and Comparative Examples in Tables 1 and 2, the components in the formulation are stirred at a constant speed with a high-speed stirrer for 1 hour under yellow lamp conditions, then polished with a polisher and filtered through a screen mesh with a particle size of 1 μm to obtain an ink composition. The numerical values ​​shown in each of the Examples and Comparative Examples in the tables are all parts by weight.

[0046] [Table 1]

[0047] [Table 2]

[0048] In the table, the components represented by English letters are specifically as follows: A1, A1', and A1" are compounds represented by structural formula I, A2 and A2' are compounds represented by structural formula II, B1 and B2 are epoxy compounds, B3 is an oxetane compound, C1 and C2 are cationic initiators, D1 and D2 are pigments, and E is a sensitizer.

[0049] TIFF2025515395000010.tif30170TIFF2025515395000011.tif30170TIFF2025515395000012. tif31170TIFF2025515395000013.tif25170TIFF2025515395000014.tif24170TIFF2025515395 000015.tif37170TIFF2025515395000016.tif26170TIFF2025515395000017.tif30170TIFF2025515395000018.tif26170B1: 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate (product number: TTA21); B2: 2,2'-[(1-methylethylene)bis(4,1-phenyleneoxymethylene)]bisoxirane (Changzhou Power Electronics New Materials Co., Ltd.) B3: 3-Ethyl-3-phenoxymethyloxetane (Changzhou Power Electronic New Materials Co., Ltd.) C1: Bis(dodecylphenyl)iodonium hexafluoroantimonate (Changzhou Powerful Electronic New Materials Co., Ltd.) C2: Thio-p-phenylenebis(4,4'-dimethyldiphenylthio)bishexafluoroantimonate (Changzhou Power Electronic New Materials Co., Ltd.) D1: Inorganic carbon black (Clariant Chemical (China) Co., Ltd.) D2: CI Pigment Yellow 155 (Shanghai Shucan Industry Co., Ltd.) E1: 9,10-diethoxy-2-ethylanthracene (model number: PSS306).

[0050] 2. Ink curing and drying speed measurement The ink to be measured in each Example and Comparative Example was printed using a Shotoku Co., Ltd. solventless inkjet printer (model number: A380), and an LED lamp with a wavelength of 395 nm was added to the printer as an irradiation light source. The ink to be measured was transferred onto a PET film (Lextec's general industrial film FP2) using the inkjet printer, the printing thickness was 5 μm, and the power of the LED light source was 20 mJ / cm 2 It was decided.

[0051] After the light irradiation, the coating was left for 24 hours, and the surface curing status was evaluated with reference to the finger touch method in the coating drying time measurement standard GB / T 1728-1979, that is, the coating layer was lightly touched with a finger, and the surface was confirmed to be dry if it was smooth, non-sticky, and no fingerprints were left when pressed. The drying speed was expressed as the maximum linear speed (m / min) at which the effect of surface drying was achieved, and the measurement results are shown in Table 3. The activity status of the composition is indicated by the curing and drying speed, and the higher the curing and drying speed, the faster the curing speed and the higher the activity of the composition.

[0052] 3. Evaluation of OD value of cured ink coating layer, adhesion fastness, and appearance of printed matter The linear speeds on the inkjet printer (Inside) were 220 m / min and 150 m / min, respectively, the substrate was a PET film (JPC-P1-125), the printing thickness was 5 μm, and the energy was 20 mJ / cm using a 395 nm LED light source. 2 After exposure, the prints were left for 24 hours, and basic performance such as the OD value of the cured coating layer, adhesion fastness, and appearance of the printed matter was evaluated. The evaluation results are shown in Table 3.

[0053] (1) Coating layer adhesion measurement According to "GB / T9286-1998 Scratch Test of Paint and Varnish Coating", the adhesion to the substrate was measured using the 100 grid cross-cut method and the QFH coating cross-cut device. The specific implementation method is as follows:

[0054] Using a knife that complies with "GB / T9286-1998 Scratch Test of Paint and Varnish Coatings", cut the surface of the coating layer, ensuring that the cut passes through the substrate surface each time, clean the surface of the coating layer with a soft brush, and then apply tape on the coating layer to ensure that the tape is in full contact with the coating layer. Finally, peel off the tape from the surface of the coating layer to evaluate the results. The judgment criteria are as follows, and the specific evaluation results are shown in Table 3.

[0055] Level 0: The edges of the cut are completely smooth and none of the lattices have been detached.

[0056] Level 1: Partial detachment of the coating layer at the intersections of the cuts, but the cross-cut area affected is not significantly greater than 5%.

[0057] Level 2: There is delamination of the coating layer along the intersections of cuts and / or along the edges of the cuts, but the area of ​​the crosscuts affected is clearly greater than 5% but not clearly greater than 15%.

[0058] Level 3: The coating layer has been partially or completely detached in the form of large fragments along the edges of the cuts and / or partially or completely detached in different parts of the lattice, with the affected cross-cut area clearly exceeding 15% but not clearly exceeding 35%.

[0059] Level 4: The coating layer has detached in the form of large pieces along the edges of the cut and / or some lattices have been partially or completely detached, with the cross-cut area affected clearly exceeding 35% but not clearly exceeding 65%.

[0060] Level 5: The degree of peeling exceeds level 4.

[0061] (2) Evaluation of the appearance of printed matter In accordance with the GB / T 7707-2008 inkjet decorative print standard, the print was inkjet printed to a depth of 10 to 18 μm, and after leaving it for 24 hours, it was placed under a sample observation light source in accordance with the CY / T 3 regulations and visually inspected.

[0062] If the printed matter meets the following conditions, it will be considered as passed. Conversely, if any of the above conditions are not met, it will be marked as failed.

[0063] (3) OD value measurement The OD value was measured using an X-rite 341C transmission density measuring device, and the higher the OD value, the clearer the pattern.

[0064] [Table 3]

[0065] As is clear from the performance evaluation results in Table 3, by using the above cationic photocurable composition as an ink, the problem of low OD value of the printed pattern can be well solved, high-precision inkjet printing can be realized, and the curing performance is excellent, especially the curing speed is obviously improved, and it has good application prospects.

[0066] As is clear from the above description, the above-mentioned embodiments of the present invention have achieved the following technical effects: By using a combination of cationic polymerizable compounds having specific structures in a specific ratio and adding an epoxy compound and / or an oxetane compound, the cationic polymerizable composition is less susceptible to the effects of humidity, effectively improves the change in dot density after ink deposition, improves optical density, and can form high-definition images on any of various recording materials, and has excellent adhesion and a fast curing speed, and can effectively expand the application range of cationic polymerizable ink when used as an ink.

[0067] The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Those skilled in the art may have various modifications and changes to the present invention. Any modifications, equivalent replacements, improvements, etc. made without departing from the spirit and principle of the present invention should be included within the protection scope of the present invention.

Claims

1. In parts by weight, the composition comprises 10 to 30 parts of a first cationically polymerizable compound, 10 to 65 parts of a second cationically polymerizable compound, 20 to 60 parts of an epoxy compound and / or an oxetane compound, 1 to 10 parts of a cationic initiator, and 2 to 20 parts of a pigment; The first cationic polymerizable compound is any one or more of the compounds represented by structural formula I, and the second cationic polymerizable compound is any one or more of the compounds represented by structural formula II, [In the formula, R ０ is any one selected from the group consisting of hydrogen, a methyl group, and an ethyl group. １ represents a methyl group or an ethyl group; n is 1 or 2. ２ represents a methyl group or an ethyl group. A cationic photocurable composition, characterized in that a total content of the first cationic polymerizable compound and the second cationic polymerizable compound is 30 wt % to 75 wt % with respect to a total content of the cationic photocurable composition.

2. The first cationically polymerizable compound is and Preferably, the second cationically polymerizable compound is 2. The cationic photocurable composition according to claim 1, wherein

3. The epoxy compound may be 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate, bis(3,4-epoxycyclohexylmethyl)adipate, a caprolactone-modified compound of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate, an ester compound of a polyvalent carboxylic acid and 3,4-epoxycyclohexylmethyl alcohol or a caprolactone-modified compound, a silicone compound having an alicyclic epoxy group at a terminal, a diglycidyl ether of bisphenol A, a diglycidyl ether of bisphenol F, a diglycidyl ether of brominated bisphenol A, a phenol novolac type epoxy resin, a cresol novolac type epoxy resin, a biphenyl type epoxy resin, diglycidyl terephthalate, diglycidyl phthalate, an addition reaction product of polybutadiene having a carboxylic acid group at its terminal and bisphenol A type epoxy resin, dicyclopentadiene dioxide, limonene dioxide, 4-vinylcyclohexene dioxide, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, epoxidized vegetable oil, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 3-glycidyloxypropyltrimethoxysilane, and 3-glycidyloxypropylmethyldimethoxysilane, and / or the oxetane compound includes any one or more selected from the group consisting of 3-benzyloxymethyl-3-ethyloxetane, 3-ethyl-3-phenoxymethyloxetane, 3,3'-[2-(benzyloxy)propane-1,3-dimethoxydiethyloxetane], and 3-ethyl-3-methoxyoxetane methacrylate.

4. The cationic initiator comprises an iodonium salt and / or sulfonium salt photoinitiator; 2. The cationic photocurable composition according to claim 1, wherein the cationic initiator is optionally one or more selected from the group consisting of diaryliodonium salts of sulfonic acid, triarylsulfonium salts of sulfonic acid, diaryliodonium salts of boric acid, triarylsulfonium salts of boric acid, diaryliodonium salts of phosphoric acid, diarylsulfonium salts of phosphoric acid, diaryliodonium salts of antimonic acid, and triarylsulfonium salts of antimonic acid.

5. 2. The cationic photocurable composition according to claim 1, wherein the pigment is an organic pigment and / or an inorganic pigment, and the color of the pigment includes any one or more of black, blue, brown, blue-green, green, white, purple, magenta, red, orange, and yellow.

6. The cationic photocurable composition further comprises a sensitizer, Preferably, the content of the sensitizer is 0.1 wt % to 10 wt %, preferably 3 wt % to 8 wt %, based on the cationic photocurable composition; The cationic photocurable composition according to claim 1, wherein the sensitizer comprises one or more selected from the group consisting of thioxanthone compounds, xanthone compounds, acridine compounds, anthracene compounds, and coumarin compounds, and more preferably the sensitizer is one or more selected from the group consisting of anthracene compounds and thioxanthone compounds.

7. The cationic photocurable composition according to any one of claims 1 to 6, characterized in that a total content of the first cationic polymerizable compound and the second cationic polymerizable compound is 30 wt % to 60 wt % with respect to a total content of the cationic photocurable composition, and a ratio of the amount of the first cationic polymerizable compound to the amount of the second cationic polymerizable compound used is 1:5 to 3:

1.

8. The cationic photocurable composition according to any one of claims 1 to 6, further comprising an auxiliary, the auxiliary comprising any one or more of a leveling agent, a dispersant, a curing agent, a surfactant, a defoaming agent, and a storage stabilizer.

9. The cationic photocurable composition according to any one of claims 1 to 6, characterized in that the viscosity of the cationic photocurable composition is less than 50 mPa·s, preferably 2 to 30 mPa·s.

10. Use of the cationic photocurable composition according to any one of claims 1 to 9 in an ink.

11. The substrate used in the ink includes any one of a film, glass, and plastic; Use according to claim 10, characterized in that the ink jet thickness of said ink is preferably between 0.1 and 10 μm, more preferably between 0.5 and 5 μm.

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