Cationic photocurable compositions and their use

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, and specifically, to a cationic photocurable composition and its use.

Background Art

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

[0003] In inkjet printing, the ink ejected from the nozzles of an inkjet head forms dots after spreading to a predetermined size after falling on a substrate. When the dot density is low, the ink cannot cover the surface of the substrate, leaving blank portions, so the OD value (optical density) decreases and a high-definition printed pattern cannot be obtained.

[0004] To solve this problem, there are many improvements such as focusing on pigments to improve the OD value (optical density), or improving the image resolution or increasing the ink amount per dot. However, as the concentration of the pigment increases, the stability of the composition decreases, and when the size of the droplets is reduced to improve the image quality, the sensitivity clearly decreases. Also, when the ink amount per dot is increased, the penetration phenomenon is likely to occur. Further, it is difficult to achieve the required OD value 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: radical 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 practical applications due to their wide range of material selection, but they are greatly affected by oxygen inhibition, resulting in insufficient ink curing. When forming images on non-absorbent substrates, such as plastics, glass, and metals, bleeding occurs between uncured inks, degrading 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, especially non-absorbent substrates such as plastics, glass, and metals. However, the dot density after application tends to decrease, resulting in a lower OD value (optical density) and making it impossible to form high-resolution images on various recording materials. Improving the OD value of cationic inkjet inks is of significant importance for improving the overall performance of inkjet printing. [Overview of the project]

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

[0007] To achieve the above objective, according to one aspect of the present invention, the mixture comprises, by weight, 10 to 30 parts of a first cationic polymerizable compound, 10 to 65 parts of a second cationic 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 one or more of the compounds shown in structural formula I, and the second cationic polymerizable compound is one or more of the compounds shown in structural formula II. TIFF0007843073000001.tif38170[In the formula, R0 is 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 present invention provides a cationic photocurable composition in which the total content of the first cationic polymerizable compound and the second cationic polymerizable compound is 30 wt% to 75 wt% relative to the total content of the cationic photocurable composition.

[0008] Furthermore, the first cationic polymerizable compound is It is TIFF0007843073000002.tif38170, Preferably, the second cationic polymerizable compound is The filename is TIFF0007843073000003.tif15170.

[0009] Furthermore, epoxy compounds include 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate, bis(3,4-epoxycyclohexylmethyl) adipate, caprolactone-modified compounds of 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate, ester compounds of polycarboxylic acids and 3,4-epoxycyclohexylmethyl alcohol or caprolactone-modified compounds, silicone compounds having alicyclic epoxy groups at the terminals, diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F, diglycidyl ether of brominated bisphenol A, phenol novolac type epoxy resins, cresol novolac type epoxy resins, and bisphenol A. It comprises one or more selected from the group consisting of phenyl epoxy resin, diglycidyl terephthalate, diglycidyl phthalate, an addition reaction product of polybutadiene having a carboxylic acid group at the 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 comprises 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] Furthermore, the cationic initiator includes iodonium salts and / or sulfonium salt photoinitiators, and optionally, 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 antimony acid, and triarylsulfonium salt of antimony acid.

[0011] Furthermore, the pigments are organic pigments and / or inorganic pigments, and the color of the pigments includes one or more of the following: black, blue, brown, blue-green, green, white, purple, magenta, red, orange, and yellow.

[0012] Furthermore, the cationic photocurable composition further contains a sensitizer, Preferably, the sensitizer content is 0.1 wt% to 10 wt% relative to the cationic photocurable composition, more preferably 3 wt% to 8 wt%. Preferably, 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 comprises 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% of 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 used is 1:5 to 3:1.

[0014] Furthermore, the cationic photocurable composition further contains an auxiliary agent, which includes one or more of the following: leveling agents, dispersants, curing agents, surfactants, defoaming agents, and storage stabilizers.

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

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

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

[0018] By applying the technical method of the present invention, and using a combination of cationic polymerizable compounds of a specific structure in specific proportions, while adding epoxy compounds and / or oxetane compounds, the synergistic effect of the cationic polymerizable compounds and epoxy compounds and / or oxetane compounds results in a cationic polymerizable composition that is less affected by humidity, effectively improves the change in point density after ink application, enhances optical density, can form high-definition images on various recording materials, has excellent adhesion, a fast curing speed, and can effectively expand the range of applications of cationic polymerizable inks when used as an ink. [Modes for carrying out the invention]

[0019] In addition, the embodiments and features described herein may be combined with each other, as long as there is no contradiction. The present invention will be described in detail below with reference to the embodiments.

[0020] As analyzed in the background art of this application, in the prior art, the point density tends to decrease after the application of cationic photocurable ink, causing a decrease in the OD value (optical density), which makes it impossible to form high-resolution images on various recording materials. To solve this problem, a cationic photocurable composition and its use are provided.

[0021] According to one representative embodiment of the present application, in parts by weight, it contains 10 to 30 parts of a first cationic polymerizable compound, 10 to 65 parts of a second cationic 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 two or more of the compounds represented by Structural Formula I, and the second cationic polymerizable compound is any one or two or more of the compounds represented by Structural Formula II. TIFF0007843073000004.tif38170[Wherein, 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.] Provided is a cationic photocurable composition 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] In the present application, while using cationic polymerizable compounds with a specific structure in combination at a specific ratio, an epoxy compound and / or an oxetane compound is added. Due to the synergistic effect of the above cationic polymerizable compound, the epoxy compound and / or the oxetane compound, the cationic polymerizable composition is less affected by humidity, effectively improves the change in dot density after ink adhesion, improves the optical density, can form high-definition images for any of various recording materials, has excellent adhesion, a fast curing rate, and when used as an ink, can effectively expand the application range of the cationic polymerizable ink.

[0023] In some preferred embodiments of the present application, the above first cationic polymerizable compound is TIFF0007843073000005.tif38170, the production is relatively simple, and it can better exert a synergistic effect with the second cationic polymerizable compound, the epoxy compound and / or the oxetane compound, and further improve the optical density. Preferably, the second cationic polymerizable compound is TIFF0007843073000006.tif is 16170, 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 simultaneously contain an epoxy compound and an oxetane compound, or may contain either of these compounds. The specific types of the epoxy compound and the oxetane compound may be selected from the prior art, but are not limited herein.

[0025] In some examples 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, caprolactone-modified compounds of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, ester compounds of polycarboxylic acid and 3,4-epoxycyclohexylmethyl alcohol or caprolactone-modified compounds, silicone compounds having alicyclic epoxy groups at the terminal, diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F, diglycidyl ether of brominated bisphenol A, phenol novolac type epoxy resin, cresol novolac type epoxy resin The material contains one or more selected from the group consisting of lipids, biphenyl-type epoxy resins, diglycidyl terephthalate, diglycidyl phthalate, addition reaction products of polybutadiene having a carboxylic acid group at the 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.

[0026] In some examples 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, and the TCM series and THM series products of the strong manufacturer. Preferably, the curing and drying speed of the composition can be further improved by using an epoxy compound and / or oxetane compound in a cationic photocurable composition at a rate of 30 to 55 wt%, for example, 35 wt%, 40 wt%, 45 wt%, or 50 wt%.

[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% of the total amount of the cationic photocurable composition, and the printed pattern of the composition has a high OD value and excellent overall performance such as appearance.

[0028] The cationic initiator may be selected from the prior art, for example, the cationic initiator may be selected from iodonium salts and / or sulfonium salt photoinitiators. In some examples 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 antimony acid, and triarylsulfonium salt of antimony acid, which can further improve the curing speed of the cationic photocurable composition.

[0029] For example, the above cationic photoinitiators include 4-phenylthiotriphenylsulfonium hexafluoroantimonate, 4-phenylthiotriphenylsulfonium hexafluorophosphate, 4-phenylthiotriphenylsulfonium camphor sulfonate, 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, and 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 salt of perfluoroalkylsulfonic acid, diaryliodonium salt of perfluorobutanesulfonic acid, diaryliodonium salt of perfluoroethanesulfonic acid, diaryliodonium salt of perfluorooctanesulfonic acid, diaryliodonium salt of trifluoromethanesulfonic acid, diaryliodonium salt of p-tolylsulfonic acid, diaryliodonium salt of dodecylbenzenesulfonic acid, diaryliodonium salt of benzenesulfonic acid It may be one or more selected from the group consisting of: um salt, diaryliodonium salt of 3-nitrobenzenesulfonic acid, triarylsulfonium salt of perfluorobutanesulfonic acid, triarylsulfonium salt of perfluoroethanesulfonic acid, triarylsulfonium salt of perfluorooctanesulfonic acid, triarylsulfonium salt of trifluoromethanesulfonic acid, triarylsulfonium salt of p-tolylsulfonic acid, triarylsulfonium salt of dodecylbenzenesulfonic acid, triarylsulfonium salt of benzenesulfonic acid, triarylsulfonium salt of 3-nitrobenzenesulfonic acid, diaryliodonium salt of arylboric acid perhalide, and triarylsulfonium salt of arylboric acid perhalide.

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

[0031] The pigment in the above-mentioned cationic photocurable composition is a colorant, which 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, blue-green, green, white, purple, magenta, red, orange, yellow, or a mixture thereof. For example, organic pigments are 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, carbazoledioxazine violet pigments, alizarin lake pigments, phthalamide pigments, carmine lake pigments, tetrachloroisoindolinone pigments, perinone pigments, anthraquinone pigments, and quinophthalone pigments. Inorganic pigments are one or more selected from the group consisting of titanium oxides (e.g., titanium dioxide, conductive titanium dioxide), iron oxides (e.g., red iron oxide, yellow iron oxide, black iron oxide, and transparent iron oxide), aluminum oxides, silicon oxides, carbon black pigments, metal sulfides, and metal chlorides.

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

[0033] In some embodiments of the present application, the sensitizer comprises one or more compounds selected from the group consisting of thioxanthone compounds, xanthone compounds, acridine compounds, anthracene compounds, and coumarin compounds. Preferably, the sensitizer comprises one or more compounds selected from the group consisting of anthracene compounds and thioxanthone compounds. Examples include JRCure-1105(ITX) and JRCure-1106(DETX) manufactured by Tianjin Jiuri New Materials Co., Ltd., and PSS303, PSS306, PSS510, PSS513, PSS515, PSS402, PSS403, and PSS603 manufactured by Changzhou Strong Electronics New Materials Co., Ltd. When used in combination with the cationic polymerizable compound of the present application, it exhibits better photosensitivity and particularly excellent overall 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 sharper pattern, the total content of the first cationic polymerizable compound and the second cationic polymerizable compound is 30 wt% to 60 wt% of the total content of the cationic photocurable composition, for example, 35 wt%, 40 wt%, 45 wt%, 50 wt%, or 55 wt%, and the ratio of the amount of the first cationic polymerizable compound to the second cationic polymerizable compound used 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 between the two.

[0035] As an optional choice for the product's usage environment, the cationic photocurable composition of this application may selectively contain one or more organic and / or inorganic additives commonly used in the art, such as leveling agents, dispersants, curing agents, surfactants, defoamers, and storage stabilizers. Specific components and amounts of these additives may be referenced from the prior art, but are omitted here.

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

[0037] The cationic photocurable composition of this application is not particularly limited in terms of the form of the initiation energy source, and polymerization reactions occur upon irradiation with energy sources such as ultraviolet light, visible light, infrared light, electron beams, and lasers, enabling rapid curing. For example, the initiation energy source may be an ultra-high pressure mercury lamp with a wavelength of 200 to 500 nm, 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 third-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, or active light such as i-rays, h-rays, or g-rays. The composition may be further cured by energy such as electron beams, alpha rays, beta rays, gamma rays, X-rays, and neutrons. Preferably, a mercury lamp, ultraviolet lamp, or UV-LED lamp with a wavelength range of 200 to 500 nm may be used, and the irradiation energy is preferably 20 to 1000 mJ / cm². 2 Therefore, when curing with a long-wavelength energy source, it is preferable to add a sensitizer to the composition to improve its photosensitivity.

[0038] An active energy ray-curable inkjet ink can be obtained by uniformly mixing each component of the cationic photocurable composition of this application. For specific manufacturing processes, refer to the manufacturing methods of photocurable compositions in the prior art. Typically, the manufacturing process involves compounding, pre-dispersion, polishing, and filtration (filtration with a screen mesh of a predetermined size to obtain a product with a desired particle size) under conditions of constant temperature, constant humidity, and shielding of the irradiation light source to obtain an inkjet ink.

[0039] Another representative embodiment of the present application provides for the use of any one of the above-mentioned cationic photocurable compositions in an ink.

[0040] By using the above-mentioned cationic photocurable composition as an ink, the problem of low OD values ​​of printed patterns can be effectively solved, high-precision inkjet printing can be achieved, and the curing performance is excellent, with a particularly clear improvement in curing speed, making it a promising candidate for various applications.

[0041] When the above-mentioned cationic photocurable composition is used as an ink, the application method is not particularly limited and may be based on prior art. In addition to the inkjet printing method, other well-known methods such as the dip method, air knife coating method, curtain coating method, roll coating method, die coating method, wire bar coating method, etc., may also be used.

[0042] When the above cationic photocurable composition is used as an ink, there are no particular restrictions on the substrate used; for example, the substrate may be any one of film, glass, or plastic. Depending on the material of the selected substrate, a surface treatment, such as corona treatment, may be selectively performed.

[0043] The thickness of the cured coating layer of a pattern inkjet-printed with the cationic photocurable composition of this application can be adjusted according to the prior art or the purpose of use. Preferably, the thickness of the inkjet-printed pattern is 0.1 to 10 μm, and particularly preferably 0.5 to 5 μm, as this results in a relatively uniform coating layer and is advantageous for cost control. This is because if the thickness of the ink coating layer is too small, it may not be possible to form a uniform coating layer, or it may be difficult to print accurately according to the design. If the thickness is too large, the coating layer will consume a large amount of printing ink, leading to increased costs, and it may be disadvantageous for uniform application, and the coating layer may be brittle and prone to separation.

[0044] The beneficial effects of this application will be further explained below with reference to the 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 of the formulation were stirred at a constant speed for 1 hour in a high-speed stirrer under yellow lamp conditions, then polished in a polishing machine, and filtered through a screen mesh with a particle size of 1 μm to obtain the ink composition. The values ​​shown in each example and comparative example in the table are all in parts by weight.

[0046] [Table 1]

[0047] [Table 2]

[0048] In the table, the components represented by letters are specifically as follows: A1, A1', and A1'' are compounds shown by structural formula I; A2 and A2' are compounds shown 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] TIFF0007843073000009.tif30170TIFF0007843073000010.tif30170TIFF0007843073000011. tif31170TIFF0007843073000012.tif25170TIFF0007843073000013.tif24170TIFF0007843073 000014.tif37170TIFF0007843073000015.tif26170TIFF0007843073000016.tif30170TIFF0007843073000017.tif26170B1:3,4-Epoxycyclohexylmethyl-3',4'-Epoxycyclohexanecarboxylate (Model number: TTA21); B2:2,2'-[(1-methylethylene)bis(4,1-phenyleneoxymethylene)]bisoxiran (Changzhou Strong Electronics New Materials Co., Ltd.) B3: 3-Ethyl-3-Phenoxymethyloxetane (Changzhou Strong Electronic New Materials Co., Ltd.) C1: Bis(dodecylphenyl)iodonium hexafluoroantimonate (Changzhou Strong Electronic New Materials Co., Ltd.) C2: Thio-p-phenylenebis(4,4'-dimethyldiphenylthio)bishexafluoroantimonate (Changzhou Strong Electronic New Materials Co., Ltd.) D1: Inorganic carbon black (Clariant Chemical (China) Co., Ltd.) D2: CI Pigment Yellow 155 (Shanghai Shucan Industrial Co., Ltd.) E1: 9,10-Diethoxy-2-ethylanthracene (Model number: PSS306).

[0050] 2. Measuring the curing and drying speed of the ink. The inks to be measured for each example and comparative example were printed using a solvent-free inkjet printer (model: A380) from Matsutoku Co., Ltd., and a 395nm wavelength LED lamp was added to the printer as an illumination light source. The inks to be measured were transferred onto a PET film (Rakukai's general industrial film FP2) using the inkjet printer, with a print thickness of 5μm, and the LED light source power set to 20mJ / cm². 2 That's what I decided.

[0051] After light irradiation, the surface hardening status is evaluated by referring to the finger touch method in the coating film drying time measurement standard GB / T 1728-1979. That is, the surface is confirmed to be dry when the surface is smooth, non-sticky, and does not leave fingerprints when pressed, by lightly touching the coating layer with a finger. The drying rate is expressed as the maximum linear velocity (m / min) at which the surface drying effect is achieved, and the measurement results are shown in Table 3. The curing and drying rates indicate the activity level of the composition; the higher the curing and drying rates, the faster the curing rate and the higher the activity level of the composition.

[0052] 3. Evaluation of the OD value, adhesion fastness, and appearance of the printed material of the ink-cured coating layer. The linear speeds on the inkjet printer (Inside) were set to 220 m / min and 150 m / min, respectively. The substrate was PET film (JPC-P1-125), the print thickness was 5 μm, and the energy was 20 mJ / cm² using a 395 nm LED light source. 2 The prints were irradiated and left for 24 hours after exposure. Basic performance such as the OD value of the hardened coating layer, adhesion fastness, and appearance of the printed material were evaluated, and the evaluation results are shown in Table 3.

[0053] (1) Measurement of coating layer adhesion strength Adhesion to the substrate was measured using the 100-grid cross-cut method and the QFH coating cross-cut apparatus, in accordance with "GB / T9286-1998 Scratch Experiment of Paint and Varnish Coatings". The specific procedure is as follows:

[0054] Using a knife conforming to "GB / T9286-1998 Scratch Experiment of Paint and Varnish Coatings," the surface of the coating layer was cut, ensuring that each cut passed through the substrate surface. The surface of the coating layer was then cleaned with a soft brush. After that, tape was applied to the coating layer, ensuring that the tape made complete contact with the coating layer. Finally, the tape was peeled off the surface of the coating layer, and the results were evaluated. The basis for the judgment is as follows, and the specific evaluation results are shown in Table 3.

[0055] Level 0: The edges of the cut are perfectly smooth, and no lattice is peeling.

[0056] Level 1: The court layer is partially peeled at the cross-cut intersection, but the affected cross-cut area clearly does not exceed 5%.

[0057] Level 2: There is delamination of the coat layer along the intersection and / or edges of the cut, but the affected crosscut area is clearly more than 5%, but clearly not more than 15%.

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

[0059] Level 4: The coat layer peels off in the form of large fragments along the edges of the cut, and / or some lattices peel off partially or completely, with the affected cross-cut area 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 the printed material In accordance with the GB / T 7707-2008 inkjet decorative printing standard, the prints were printed with an inkjet to a depth of 10-18 μm, left for 24 hours, and then visually inspected under a sample observation light source compliant with CY / T 3 specifications.

[0062] A print is deemed acceptable if it meets the following conditions: the printed material is neat and free from obvious ink smudges, defects, or cuts; the text is clear and complete, free from defects or deformation, and text smaller than 7.5p does not affect readability; the edges of solid print traces are smooth, the ink color is uniform, and there are no obvious watery patterns; the tonal transitions of the print are smooth, and there are no obvious step-by-step changes in tone; the dots are clear and uniform, free from obvious deformation and defects; and the hue of the print meets the requirements for the sample attached to the print. Conversely, if any of the above conditions are not met, it will be marked as unacceptable.

[0063] (3) Measurement of OD value The transmission density was measured using the X-rite 341C, 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, using the above-mentioned cationic photocurable composition as an ink effectively solves the problem of low OD values ​​of printed patterns, enables high-precision inkjet printing, and exhibits excellent curing performance, particularly a clear improvement in curing speed, making it a promising candidate for application.

[0066] As is clear from the above description, the above embodiments of the present invention achieve the following technical effects. By using a combination of cationic polymerizable compounds of a specific structure in specific proportions, and adding an epoxy compound and / or an oxetane compound, the synergistic effect of the cationic polymerizable compound and the epoxy compound and / or oxetane compound results in a cationic polymerizable composition that is less affected by humidity, effectively improves the change in point density after ink application, enhances optical density, can form high-definition images on any of various recording materials, has excellent adhesion, a fast curing speed, and can effectively expand the range of application of cationic polymerizable inks when used as an ink.

[0067] The foregoing are merely preferred embodiments of the present invention and are not intended to limit the invention, and various modifications and changes are possible for those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and principles of the present invention should all be within the scope of protection of the present invention.

Claims

1. A cationic photocurable composition comprising, per 100 parts by weight of the entire composition, 10 to 30 parts by weight of a first cationic polymerizable compound, 10 to 65 parts by weight of a second cationic polymerizable compound, 20 to 60 parts by weight of an epoxy compound and / or an oxetane compound, 1 to 10 parts by weight of a cationic initiator, and 2 to 20 parts by weight of a pigment. The first cationic polymerizable compound is one or more of the compounds represented by structural formula I, and the second cationic polymerizable compound is one or more of the compounds represented by structural formula II. [In the formula, R ０ R is one of the elements 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. R ２ This represents a methyl group or an ethyl group. A cationic photocurable composition characterized in that the total content of the first cationic polymerizable compound and the second cationic polymerizable compound is 30 wt% to 75 wt% relative to the total content of the cationic photocurable composition.

2. The first cationic polymerizable compound is And, The second cationic polymerizable compound is The cationic photocurable composition according to claim 1, characterized in that it is the same as the one described in claim 1.

3. The epoxy compounds include 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, bis(3,4-epoxycyclohexylmethyl) adipate, caprolactone-modified compounds of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, ester compounds of polycarboxylic acid and 3,4-epoxycyclohexylmethyl alcohol or caprolactone-modified compounds, silicone compounds having alicyclic epoxy groups at the terminals, diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F, diglycidyl ether of brominated bisphenol A, phenol novolac type epoxy resin, cresol novolac type epoxy resin, and biphenyl It comprises one or more selected from the group consisting of type epoxy resin, diglycidyl terephthalate, diglycidyl phthalate, an addition reaction product of polybutadiene having a carboxylic acid group at the 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. The cationic photocurable composition according to claim 1, characterized in that the oxetane compound comprises 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 photocurable composition according to claim 1, characterized in that the cationic initiator comprises an iodonium salt and / or a sulfonium salt photoinitiator.

5. The cationic photocurable composition according to Claim 1, characterized in that the cationic initiator is one or more selected from the group consisting of 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 antimony acid, and triarylsulfonium salt of antimony acid.

6. The cationic photocurable composition according to claim 1, characterized in that the pigment is an organic pigment and / or an inorganic pigment, and the color of the pigment includes one or more of the following: black, blue, brown, blue-green, green, white, purple, magenta, red, orange, and yellow.

7. The aforementioned cationic photocurable composition further comprises a sensitizer, The content of the sensitizer is 0.1 wt% to 10 wt% relative to the cationic photocurable composition. The cationic photocurable composition according to claim 1, characterized in that the sensitizer comprises one or more selected from the group consisting of thioxanthone compounds, xanthone compounds, acridine compounds, anthracene compounds, and coumarin compounds.

8. The cationic photocurable composition according to claim 1, characterized in that the total content of the first cationic polymerizable compound and the second cationic polymerizable compound is 30 wt% to 60 wt% of 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 used is 1:5 to 3:

1.

9. The cationic photocurable composition according to claim 1, further comprising an auxiliary agent, wherein the auxiliary agent comprises one or more of the following: a leveling agent, a dispersant, a curing agent, a surfactant, an antifoaming agent, and a storage stabilizer.

10. The cationic photocurable composition according to claim 1, characterized in that the viscosity of the cationic photocurable composition is less than 50 mPa·s.

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

12. The substrate used in the aforementioned ink includes one of the following: film, glass, and plastic. The use according to claim 11, characterized in that the inkjet thickness of the ink is 0.1 to 10 μm.

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