CN112011213A

CN112011213A - Photo-curing printing ink and application thereof

Info

Publication number: CN112011213A
Application number: CN201910465551.8A
Authority: CN
Inventors: 钱彬; 杨金梁; 严春霞
Original assignee: Changzhou Green Photosensitive Materials Co ltd
Current assignee: Changzhou Green Photosensitive Materials Co ltd
Priority date: 2019-05-30
Filing date: 2019-05-30
Publication date: 2020-12-01

Abstract

The invention provides a photo-curing printing ink and application thereof. The photo-curing ink comprises an alicyclic epoxy compound, an oxetane compound and a photoinitiator; wherein, the alicyclic epoxy compound comprises a compound shown in a general formula I and a general formula II, or comprises a compound shown in a general formula III and a general formula IV. The photo-curing ink composition provided by the invention has the advantages of good storage stability, high curing speed, small influence of moisture during curing, and excellent solvent resistance and adhesive force performance after film forming. Meanwhile, the photocuring ink can meet the requirement of high-speed printing, is high in production efficiency, is particularly suitable for bearing substrates such as plastic films and the like, has strong market competitiveness, and is suitable for further popularization and application.

Description

Photo-curing printing ink and application thereof

Technical Field

The invention relates to the field of printing, in particular to photo-curing ink and application thereof.

Background

The ink is a material which can be physically or chemically formed into a film, is printed on a printing stock through a corresponding printing process and has a certain function. In order to meet the requirements of the printing process, a solvent is often required to be added, and the printing mode is mostly solvent-based thermosetting, so that the problem of air pollution caused by an organic solvent is easily caused.

VOC emission in the packaging and printing industry of China reaches 100-200 tons, especially Volatile Organic Compounds (VOC) emission in gravure film printing accounts for 80%, and a compendium document proposes that 60% of solvent-based ink is replaced in 2019, so that green replacement of packaging ink is imminent.

At present, the conventional production line mainly has two directions for improving the traditional solvent type ink: water-based inks and photo-curable inks. Among them, the water-based ink has low water resistance, is likely to cause blurring, has poor adhesion to a non-water-absorbing substrate, and cannot form an image. The photo-curing ink is divided into free radical curing ink and cation curing ink according to different curing mechanisms, the cross-linking of ink components can be inhibited due to the existence of oxygen when the free radical UV curing ink is irradiated by ultraviolet light, so that the possibility of forming high polymers by connecting monomers and oligomers is reduced, and the photo-curing ink has larger shrinkage after photo-curing and influences the adhesive force with a substrate. It is in this case that the skilled person proposes to use cationic UV-curable inks.

Unlike free radical UV curable inks, cationic UV curable inks will continue to crosslink the monomers and oligomers after the UV light source is removed until the ink film is completely polymerized. Polymerizable monomers generally used for cationic UV curable inks include epoxy compounds and oxetane compounds, and for example, Japanese patent application No. 2002-. However, although the active energy ray-curable composition has relatively good curability, the resulting cured product thereof has insufficient adhesion. Furthermore, U.S. Pat. No. 4, 7888401, 2 discloses a composition containing an oxetane compound in addition to a cationically polymerizable compound containing an oxetane and a cycloaliphatic epoxy compound, even at a curing energy of 20mJ/cm²The image can also be transferred completely, exhibiting good curing properties, but the patent is silent as to whether the composition can meet the demand for high-speed printing.

Disclosure of Invention

The invention mainly aims to provide photocuring ink and application thereof, and aims to solve the problems that in the prior art, the photocuring ink is insufficient in adhesive force and cannot meet the requirement of high-speed printing.

In order to achieve the above object, according to one aspect of the present invention, there is provided a photocurable ink including a cycloaliphatic epoxy compound, an oxetane compound and a photoinitiator; wherein,

the alicyclic epoxy compound comprises a compound shown in a general formula I and a general formula II, or comprises a compound shown in a general formula III and a general formula IV, wherein the general formulas I, II, III and IV are respectively as follows:

general formula I, II, III, IV, R₁、R₂、R₃、R₄、R₅、R₆Each independently selected from hydrogen, methyl or ethyl, R₇、R₈、R₉、R₁₀、R₁₁、R₁₂、R₁₃、R₁₄、R₁₅Each independently selected from hydrogen, alkyl, alkenyl, aryl, alkoxy, hydroxymethyl, hydroxyethyl, carboxyl, mercapto, amino substituted by alkyl, alkenyl, aryl or alkoxy, amido, nitro, cyano, acyl, ester, epoxy, a heterocyclic structure-containing group or a halogen atom, and A is-CO-O-or-O-CO-.

According to another aspect of the invention, the application of the photo-curing ink as an ink film of paper, plastic, metal and glass products is also provided.

The photo-curing ink composition provided by the invention has the advantages of good storage stability, high curing speed, small influence of moisture during curing, and excellent solvent resistance and adhesive force performance after film forming. Meanwhile, the photocuring ink can meet the requirement of high-speed printing, is high in production efficiency, is particularly suitable for bearing substrates such as plastic films and the like, has strong market competitiveness, and is suitable for further popularization and application.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail with reference to examples.

As described in the background of the invention section, the photo-curable ink in the prior art has the problems of insufficient adhesion and not satisfying the requirement of high-speed printing.

The present invention has been made to solve the above problems, and provides a photocurable ink comprising an alicyclic epoxy compound, an oxetane compound and a photoinitiator; wherein,

The light-cured printing ink provided by the invention adopts alicyclic epoxy compounds with special structures, and the alicyclic epoxy compounds are used in combination of compounds in a general formula I and a general formula II or in combination of compounds in a general formula III and a general formula IV. The alicyclic epoxy compound is matched with an oxetane compound and a photoinitiator, so that the obtained photocuring ink is good in storage stability, high in curing speed, small in influence of moisture during curing, and excellent in solvent resistance and adhesive force performance after film forming. Meanwhile, the photocuring ink can meet the requirement of high-speed printing, is high in production efficiency, is particularly suitable for bearing substrates such as plastic films and the like, has strong market competitiveness, and is suitable for further popularization and application.

In order to further improve the overall properties of the photocurable inks, in a preferred embodiment, in the above-mentioned formulae I, II, III, IV,

alkyl is straight chain alkyl, branched chain alkyl or cycloalkyl; preferably, the straight-chain alkyl group is methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-octyl or n-nonyl, the branched-chain alkyl group is isopropyl, isobutyl, sec-butyl, tert-butyl or isooctyl, and the cycloalkyl group is cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclododecyl or norbornyl;

the alkenyl group is a straight-chain alkenyl group, a branched-chain alkenyl group or a cycloalkenyl group; preferably, the linear alkenyl group is vinyl, n-butenyl, n-propenyl, n-pentenyl, n-hexenyl, n-octenyl or n-nonenyl, the branched alkenyl group is isopropenyl, isobutenyl, sec-butenyl, tert-butenyl or isooctenyl, and the cycloalkenyl group is cyclopentenyl, cyclohexenyl, cycloheptenyl, cyclooctenyl or norbornenyl;

aryl is phenyl or substituted phenyl, naphthyl or substituted naphthyl, and the substituent is alkyl, alkenyl, alkoxy, hydroxymethyl, hydroxyethyl, carboxyl, mercapto, amino, amido, nitro, cyano, acyl, ester or epoxy; preferably, the substituted phenyl group is a 2-fluorophenyl group, a 3-fluorophenyl group, a 4-fluorophenyl group, a 2-chlorophenyl group, a 3-chlorophenyl group, a 4-chlorophenyl group, a 2-bromophenyl group, a 2-methylphenyl group, a 4-methoxyphenyl group or a 4-acetylphenyl group;

the alkoxy is C1-C10 alkoxy, phenoxy, benzyloxy or naphthoxy; preferably, the alkoxy of C1-C10 is methoxy, ethoxy, propoxy, butoxy, tert-butoxy or cyclohexyloxy;

the heterocyclic structure-containing group is an aziridine group, an oxirane group, an epithioethane group, an aziridine group, an oxirane group, a thioaziridine group, an azetidine group, an oxetane group, a thietane group, an azetidine group, a tetrahydropyrrole group, a tetrahydrofuran group, a tetrahydrothiophene group, a pyrrole group, a furan group, a thiol group, an azine group, a thiolane group, a pyridine group, a cyclohexylimine group, an epoxyhexane group, a thietane group, an azepine group, an oxaheptene group, an imidazole group, an imidazoline group, a pyrazine group, a morpholine group, a thiazine group, an indole group, an isoindole group, a benzimidazole group, a purine group, a quinoline group, an isoquinoline group, or a benzopyran group;

the halogen atom is fluorine, chlorine, bromine or iodine atom.

More preferably, the alicyclic epoxy compound comprises 1-99% of the compound shown in the general formula I and 1-99% of the compound shown in the general formula II by weight percentage. Thus, the ink has a lower viscosity, and has good processability, productivity, water resistance and heat resistance, and is more excellent in solvent resistance and adhesion.

It is to be noted that the above-mentioned alicyclic epoxy compounds of the present invention can be obtained commercially or can be prepared by a conventionally known method.

Illustratively, the cycloaliphatic epoxy compound includes at least two of the compounds represented by the following structures:

the oxetane compound is not particularly limited, and those oxetane monomers which are generally used in the field of photocuring can be used. In a preferred embodiment, the oxetane compound is a monofunctional compound and/or a polyfunctional compound. In order to further improve the overall properties of the ink, the monofunctional compound is preferably 3-methyl-3-hydroxymethyloxetane, 3-ethyl-3- (hexyloxymethyl) oxetane, 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane, 3-ethyl-3- [ (phenoxy) methyl ] oxetane, 3-ethyl-3- (chloromethyl) oxetane, isobutoxymethyl (3-ethyl-3-oxetanylmethyl) ether, isobornyloxyethyl (3-ethyl-3-oxetanylmethyl) ether, isobornyl (3-ethyl-3-oxetanylmethyl) ether, one or more of 2-ethylhexyl (3-ethyl-3-oxetanylmethyl) ether, ethyldiethylene glycol (3-ethyl-3-oxetanylmethyl) ether; preferably, the polyfunctional compound is bis [ 1-ethyl (3-oxetanyl) ] methyl ether, 3-bis (chloromethyl) oxetane, 3, 7-bis (3-oxetanyl) -5-oxa-nonane, 1, 2-bis [ (3-ethyl-3-oxetanylmethoxy) methyl ] ethane, 1, 3-bis [ (3-ethyl-3-oxetanylmethoxy) methyl ] propane, ethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, tricyclodecanediyldimethylene (3-ethyl-3-oxetanylmethyl) ether, trimethylolpropane tris (3-ethyl-3-oxetanylmethyl) ether, ethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, or a mixture thereof, 1, 4-bis [ (3-ethyl-3-oxetanylmethoxy) methyl ] benzene, 1, 4-bis (3-ethyl-3-oxetanylmethoxy) butane, 1, 6-bis (3-ethyl-3-oxetanylmethoxy) hexane, pentaerythritol tris (3-ethyl-3-oxetanylmethyl) ether, pentaerythritol tetrakis (3-ethyl-3-oxetanylmethyl) ether, polyethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol hexa (3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol penta (3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol tetra (3-ethyl-3-oxetanylmethyl) ether One or more of them.

In addition, oxetane compounds such as those disclosed in chinese patent applications No. 201610548580.7, 201610550205.6, 201710706339.7, 201710622973.2, 201710035210.8, 201710035435.3 (which are incorporated herein by reference in their entirety) can also be used as polymerizable compounds in the above-described inks of the present invention. Commercial products such as OXT-121, OXT-211, OXT-221, OXT-212, OXT-610, etc. of Toagosei can be used.

In a preferred embodiment, the photoinitiator is one or more of iodonium salt, sulfonium salt and arylferrocenium salt. In view of the cost and the effect of the co-use, such as photo-initiation efficiency, curing speed, etc., it is preferable that the photo-initiator is an iodonium salt and/or a sulfonium salt, and it is particularly preferable that the photo-initiator comprises a compound represented by formula V and/or formula VI:

in the general formula V, R₁And R₂Each independently selected from hydrogen and C₁～C₂₀Straight or branched alkyl of (2), C₄～C₂₀Cycloalkylalkyl or alkylcycloalkyl of (A), and acyclic-CH in these groups₂-optionally substituted by-O-, -S-or 1, 4-phenylene;

in the general formula VI, R₃And R₄Each independently selected from hydrogen and C₁～C₂₀Straight or branched alkyl of (2), C₄～C₂₀Cycloalkylalkyl or alkylcycloalkyl, C₆～C₂₀Substituted or unsubstituted aryl of (a), and acyclic-CH in these radicals₂-optionally substituted by-O-, -S-or 1, 4-phenylene; r₅Represents C₆-C₂₀Substituted or unsubstituted aryl of (1), C₆-C₂₀Substituted or unsubstituted alkylaryl of, C₁-C₂₀Straight or branched alkyl of (2), C₄-C₂₀Cycloalkylalkyl or alkylcycloalkyl, substituted or unsubstituted phenylthiophenyl, and the acyclic-CH in these groups₂-optionally substituted by carbonyl, -O-, -S-or 1, 4-phenylene; r₆And R₇Each independently represents an alkyl group, a hydroxyl group, an alkoxy group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an arylthiocarbonyl group, an acyloxy group, an arylthio group, an aryl group, a heterocycloalkyl group, an aryloxy group, an alkylsulfinyl group, an arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, a hydroxyl (poly) alkyleneoxy group, a substitutable amino group, a cyano group, a nitro group or a halogen atom; m is₁、m₂Each represents R₆And R₇The number of (a) is selected from 0, 1,2, 3 or 4;

in the general formula V and the general formula VI, X^-Each independently selected from M^-、ClO₄ ^-、CN^-、HSO₄ ^-、NO^3-、CF₃COO^-、(BM₄)^-、(SbM₆)^-、(AsM₆)^-、(PM₆)^-、Al[OC(CF₃)₃]^4-Sulfonate ion, B (C)₆M₅)₄ ^-Or [ (Rf)_bPF_6-b]^-Wherein M is a halogen atom, Rf independently represents an alkyl group in which 80% or more of hydrogen atoms are substituted with fluorine atoms, and b represents an integer of 1 to 5.

The photoinitiator is used for photocuring the alicyclic epoxy compound and the oxetane compound, and has better initiation efficiency and curing speed. More preferably, in formula V, R₁And R₂Each independently represents hydrogen, C₁～C₁₂Straight or branched alkyl of (2), C₄～C₁₀Cycloalkylalkyl or alkylcycloalkyl of (A), and acyclic-CH in these groups₂-is optionally substituted by-O-; in the general formula VI, R₃And R₄Each independently represents hydrogen, C₁～C₁₀Straight or branched alkyl of (2), C₄～C₁₀Cycloalkylalkyl or alkylcycloalkyl, C₆～C₁₂And a substituted or unsubstituted aryl group of (A), and the acyclic-CH in these groups₂-optionally substituted by-O-, -S-or 1, 4-phenylene; r₅Represents C₆～C₁₀Substituted or unsubstituted aryl of (1), C₆～C₁₀Substituted or unsubstituted alkylaryl, substituted or unsubstituted thiophenylphenyl, and the acyclic-CH in these groups₂-optionally substituted by carbonyl, -O-, -S-or 1, 4-phenylene; r₆And R₇Each independently represents C₁～C₁₀Straight or branched alkyl of (2), C₁～C₁₀Linear or branched alkoxy of (C)₁～C₁₀Alkylcarbonyl and halogen.

In a preferred embodiment, the cationic moiety of the iodonium and sulfonium salts is selected from the following structures:

the anionic moiety of the iodonium and sulfonium salts is selected from Cl^-、Br^-、PF₆ ^-、SbF₆ ^-、AsF₆ ^-、BF₄ ^-、C₄F₉SO₃ ^-、B(C₆H₅)₄ ^-、C₈F₁₇SO₃ ^-、CF₃SO₃ ^-、Al[OC(CF₃)₃]₄ ^-、(CF₃CF₂)₂PF₄ ^-、(CF₃CF₂)₃PF₃ ^-、[(CF₃)₂CF₂]₂PF₄ ^-、[(CF₃)₂CF₂]₃PF₃ ^-、[(CF₃)₂CFCF₂]₂PF₄ ^-Or (CF)₃)₂CFCF₂]₃PF₃ ^-；

Preferably, the photoinitiator is one or more of PAG20001, PAG20001s, PAG20002s, PAG30201, PAG30101, and Irgacure250 by BASF.

In order to impart color to the final ink film, in a preferred embodiment, the photocurable ink further comprises a pigment; preferably, the content of the alicyclic epoxy compound in the photo-curing ink is 5-35% by weight, and more preferably 10-25% by weight; the content of the oxetane compound is 20-80%, and preferably 40-65%; the content of the photoinitiator is 0.1-10%, preferably 2-8%; the content of the pigment is 0.1-10%, preferably 2-8%. By controlling the content of each component within the above range, the ink has better processability, adhesion property and curing property, and is more suitable for high-speed printing.

The pigment is not particularly limited in kind, and may be selected from inorganic pigments and organic pigments, and any pigment used in conventional radiation-curable compositions can be used.

The inorganic pigment may be selected from or include at least one of: carbon black, titanium dioxide, aluminum oxide, red iron oxide, yellow iron oxide, iron blue, phthalocyanine blue and brown iron oxide. The carbon black may be at least one of furnace black, pyrolytic carbon black, acetylene black, or channel black.

The organic pigment may be selected from or include at least one of: azo pigments, diazo pigments, phthalocyanine pigments, anthraquinone pigments, quinophthalone pigments, thioindigo, indanthrone, anthraquinophthalone, isoviolanthrone.

The above pigments may also be selected from or include at least one of the following: pigment yellow 3, yellow 12, yellow 13, yellow 14, yellow 17, yellow 55, yellow 81, yellow 83, yellow 97, yellow 110, yellow 138, yellow 154, yellow 168, yellow 174, yellow 176, yellow 183, yellow 188, yellow 191, yellow 1, yellow 62, yellow 65, yellow 74, yellow 139, yellow 150, yellow 151, yellow 180, yellow 184; pigment Red red 2, red 8, red 21, red 48:1, red 48:2, red 48:3, red 48:4, red 52:1, red 52:2, red 53:1, red 53:2, red 112, red 144, red 146, red 166, red 169, red 184, red 202, red 254, red 269, red 3, red 22, red 49:1, red 49:2, red 57:1, red 81, red 122, red 149, red 176, red 177, red 179, red 185, red 208, red 266, red 268, red 170, red 269; pigment orange 13, orange 34, orange 36, orange 5, orange 16, orange 73; pigment violet 23, violet 27, violet 1, violet 3, violet 19; pigment green 7, green 36; pigment blue 15:1, blue 79, blue 15:0, blue 15:2, blue 15:3, blue 15:4, blue 15:6, blue 27, blue 60; orion sb4a, cabot 935, mitsubishi carbon blacks (#2650, #2600, #2350, #2300, #1000, #980, #970, #960, #950, #900, #850, #750B, #650B, MCF88, MA 600).

Optionally, the photo-curing ink of the invention further contains a sensitizer, and the type of the sensitizer can be one or a combination of more than two of thioxanthone compounds, xanthone compounds, acridine compounds, anthracene compounds, coumarin compounds, pyrazoline compounds, naphthalene compounds and tertiary amine compounds.

Illustratively, the sensitizer may be selected from compounds having the following structure:

in the photocurable composition of the present invention, the sensitizer may be a single compound or a combination of two or more compounds. The content of the component E is 0-8% by weight, preferably 1-5% by weight.

In addition to the above components a to E, organic and/or inorganic auxiliaries commonly used in the art, including but not limited to, leveling agents, dispersants, curing agents, surfactants, antifoaming agents, solvents, etc., may be optionally added to the ink of the present invention as needed according to the application environment of the product, as can be readily determined by those skilled in the art. The total content of the auxiliary agent is 0-3% of the total of the four components in parts by mass, and preferably 0-2%.

The system can also be added with a dispersing medium for the purpose of adjusting the viscosity of the system. The dispersion medium may be selected from or include at least one of the following: alcohols such as methanol, ethanol, ethylene glycol, isopropanol, butanol, octanol, cyclohexanol, diethylene glycol monoethyl ether, 2-ethylhexanol, diacetone alcohol, methyl hexanol, diethylene glycol monomethyl ether, and diethylene glycol diethyl ether; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, N-methylpyrrolidone, and diisobutyl ketone; esters such as butyl acetate, butyl butyrate, ethyl lactate, butyrolactone, ethyl acetate, diethyl oxalate, propylene glycol monoethyl ether acetate, N-dimethyl ethyl acetate, cyclohexyl acetate, ethyl benzoate, and the like; ethers such as ethylene glycol phenyl ether, ethylene glycol monomethyl ether, diethylene glycol monobutyl ether, and propylene glycol monomethyl ether; aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene; amides such as acetamide, dimethylformamide, dimethylaminoamide and the like. Preferably, the dispersion medium is at least one of methanol, isopropanol, butanol, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, toluene, xylene, and ethylbenzene. Without limitation, the amount of the dispersion medium added is 0.3 to 0.9 times the amount of the pigment added.

< preparation and use of Photocurable composition >

The components are weighed according to the amount and then uniformly mixed to obtain the photocuring composition.

The viscosity (23. + -. 2 ℃ C.) of the photocurable composition of the present invention is not particularly limited, but when a coating layer is formed by gravure printing, the viscosity is usually preferably 500 mPas or less, and preferably 10 to 200 mPas. The viscosity of the photocurable composition exceeding 200 mPas or lower than 10 mPas may result in "poor coverage", unsatisfactory imparting of decorative properties or unsatisfactory stabilization of the photocurable composition during storage. The viscosity of the photocurable composition can also be controlled, typically by the use of thickeners or thinners.

The cured coating thickness of the pattern of the photocurable composition (ink) of the present invention may vary depending on the purpose, and is preferably 0.1 to 20 μm, particularly preferably 0.5 to 15 μm. A coating layer having a thickness of less than 0.1 μm may not be uniformly formed or may be difficult to print accurately according to a design, a coating layer having a thickness of more than 20 μm may consume a large amount of printing ink, thereby causing an increase in cost, and uniform application may become difficult, and the coating layer may become brittle and be easily delaminated.

As a coating method of the above ink, there is no particular limitation, and other known methods such as a dip coating method, an air knife coating method, a curtain coating method, a roll coating method, a die coating method, a wire bar coating method, and the like can also be employed.

The light-cured composition of the present invention has no particular limitation on the form of the initiation energy source, and can be polymerized and polymerized under the irradiation of energy such as ultraviolet light, visible light, infrared light, electron beam, laser and the likeAnd (4) quickly curing. Exemplary, initiation energy sources include (but are not limited to): active rays having a wavelength of 200-500nm, such as an ultrahigh-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, a Nd-YAG3 double-wave laser, a He-Cd laser, a nitrogen laser, a Xe-Cl excimer laser, a Xe-F excimer laser, a semiconductor excited solid-state laser, i-rays, h-rays, g-rays, and the like; the composition can be cured by electron beam, alpha ray, beta ray, gamma ray, X ray, neutron ray, etc., preferably by using 200-500nm wavelength mercury lamp and UVLED lamp, preferably 50-1000 mj/cm²The irradiation energy of (1).

The light-cured ink can be used for manufacturing ink films of paper, plastics, metals and glass products.

Compared with the prior art, the photo-curing ink composition has the advantages of good storage stability, high curing speed, small influence of moisture during curing, excellent solvent resistance and adhesive force performance after film forming, high production efficiency, strong market competitiveness and suitability for further popularization and application, and can meet the requirement of high-speed printing.

The present application is described in further detail below with reference to specific examples, which should not be construed as limiting the scope of the invention as claimed.

The starting materials used in the examples are, unless otherwise indicated, conventional materials in the art and are commercially available. Except for other indications, the parts in the formula are parts by mass.

The viscosity was measured using an NDJ-79A rotational viscometer (Shanghai Changji geology instrument).

Examples

1. Preparation of photo-curing printing ink

(1) Examples 1 to 9 and comparative examples 1 to 6

Photocuring inks of examples 1 to 9 and comparative examples 1 to 6 were prepared in accordance with the formulations shown in Table 1.

TABLE 1

In the above formulation, the meanings of the components are as follows.

The carbon black is MA100 made by Mitsubishi chemical corporation; the pigment blue 1 is phthalocyanine blue K6907; the pigment yellow 1 is pigment yellow 74 produced by Taya chemical industry;

a1 denotes

a1 denotes

B1 denotes

B2 denotes

B3 denotes

C1 denotes

C2 denotes

C3 denotes

ZGJ1 is

ZGJ2 is

ZGJ3 is

BYK 307: defoaming agents; BYK 333: and (4) leveling agent.

(2) Examples 10 to 18 and comparative examples 7 to 12

The photocurable inks of examples 10 to 18 and comparative examples 7 to 12 were prepared according to the formulations shown in Table 2.

TABLE 2

In table 2, the meanings of the components are as follows.

Pigment white 1 is DuPont titanium white R706; pigment Red 1 is Lixolbar Red A68C.I. PR57: 1;

a2 denotes

a2 denotes

B4 denotes

B5 denotes

B6 denotes

C4 denotes

C5 denotes

C6 denotes

ZGJ4 denotes

ZGJ5 denotes

ZGJ6 denotes

(3) Examples 19 to 27 and comparative examples 13 to 18

Photocuring inks of examples 19 to 27 and comparative examples 13 to 18 were prepared in accordance with the formulation shown in Table 1, substituting A1 with A3, a1 with A3, and the other components being the same as those shown in Table 1.

A3 denotes

a3 denotes

(4) Examples 28 to 36 and comparative examples 19 to 24

Photocuring inks of examples 28 to 36 and comparative examples 19 to 24 were formulated in accordance with the formulation shown in Table 2, with A2 being replaced with A4, a2 being replaced with a4 and the other components being the same as those shown in Table 2.

A4 denotes

a4 denotes

(5) Examples 37 to 45 and comparative examples 25 to 30

Photocuring inks of examples 37 to 45 and comparative examples 25 to 30 were prepared in accordance with the formulation shown in Table 2, substituting A2 with A5, a2 with a5, and the other components being the same as those shown in Table 2.

A5 denotes

a5 denotes

2. Ink Performance testing and evaluation

And (3) performing performance test and evaluation on the ink samples obtained in the above examples and comparative examples by referring to QB/T1046-.

(1) Storage stability test

The inks of the examples were all measured to have a viscosity of 50 mPas or less.

The storage stability of the inks to be tested is determined with reference to the method for testing the storage stability of GB-T6753.3-1986. The specific method comprises the following steps: covering a cover on two cans of samples which are filled with the same ink and have the same weight, then placing the two cans of samples in a constant-temperature drying oven at 80 ℃, taking out the samples after 48 hours, placing the samples at room temperature for 24 hours, then measuring the viscosity of the ink to obtain the post viscosity, and carrying out grading evaluation according to the ratio percentage of the post viscosity to the initial viscosity (the ratio percentage of the two cans of samples which are the same is close to or the same and is in the following division range, otherwise, the ratio percentage is not considered), wherein the specific values are as follows:

o: the viscosity change ratio is below 5%;

very good: the viscosity change proportion is more than 5 percent and less than 10 percent;

●: the viscosity change ratio is more than 10%.

(2) Curing energy test

The ink to be tested is printed by using a Sonde solvent-free gravure printing machine (model: A380), and an LED lamp with the wavelength of 395nm is additionally arranged on the machine to be used as a radiation light source. Simultaneous energy meterPlacing on a conveyer belt, transferring the ink to be tested onto PET film (common industrial film FP2 of Lekei group) by gravure printing machine with a printing thickness of 5 μm, irradiating until the surface of the ink film is dried, and recording the curing energy value (mj/cm)²)。

3. Test and evaluation of print Performance

Setting the linear speeds of a gravure printing machine to be 220m/min and 150m/min respectively, using a PET film as a base material, setting the printing thickness to be 5 mu m, and setting the irradiation intensity of an LED light source at 385nm to be 20w/cm²After exposure, the cured coating was left for 24 hours, and the surface tension, adhesion fastness, appearance of the printed product, and the like of the cured coating were evaluated.

(1) Surface tension test

The surface tension is tested by an ARCOTEST dyne pen, the average distribution of the drawn lines is realized, and the largest dyne pen without any bead point within 3 seconds is the dyne value test.

(2) Hardness test of coating

The measurement is carried out according to GB/T6739 2006 color paint and varnish pencil method for measuring the hardness of the paint film. The specific implementation method comprises the following steps:

the pencil was inserted into the testing instrument and held in place with a clamp so that the instrument remained level, the tip of the pencil was placed on the paint film surface, then pushed at a speed of 0.5-1mm/s in a direction away from the operator for a distance of at least 7mm, and finally any debris of the pencil lead on the coating surface was wiped off with an eraser. The results were evaluated, and the coating hardness was expressed as the hardness of the pencil used when breakage occurred.

(3) Coating adhesion test

The adhesion to the substrate was tested by means of a QFH paint film scriber, using the hundred-grid scribing method, according to the GB/T9286-1998 scratch test for paint and varnish films. The specific implementation method comprises the following steps:

cutting the surface of the coating by using a cutter which accords with GB/T9286-1998 scratch test of paint films of colored paint and varnish, ensuring that the surface of the coating is scratched through to the surface of a substrate each time, cleaning the surface of the coating by using a soft brush, applying an adhesive tape on the coating to ensure that the adhesive tape is in full contact with the coating, finally tearing the adhesive tape from the surface of the coating, and evaluating the result.

Level 0: the cutting edge is completely smooth, and no lattice falls off;

level 1: a little coating falls off at the intersection of the cuts, but the cross cutting area is not influenced by more than 5 percent;

and 2, stage: the coating falls off at the intersection of the cuts and/or along the edges of the cuts, and the affected cross cutting area is obviously more than 5 percent but not obviously more than 15 percent;

and 3, level: the coating partially or completely falls off in large fragments along the cutting edge and/or partially or completely falls off at different parts of the grid, and the affected cross cutting area is obviously more than 15 percent but not obviously more than 35 percent;

4, level: the coating falls off along the large fragments of the cutting edge, and/or some squares partially or completely fall off, and the affected cross cutting area is obviously more than 35 percent, but not more than 65 percent;

and 5, stage: the degree of exfoliation was over grade 4.

(4) Coating flexibility test

The measurement was carried out according to GB/T1731-1993 paint flexibility determination method. The specific implementation method comprises the following steps:

and (3) upwards pressing a test plate paint film on a shaft rod with a specified diameter by using two hands, bending the test plate around the shaft rod within 2-3 seconds by using the force of a thumb, observing the paint film by using a 4-time magnifying lens after bending, and checking whether the paint film has the damage phenomena of reticulate patterns, cracks, peeling and the like. The rating of the paint film was recorded on a mandrel where no damage to the paint film occurred.

(5) Solvent resistance of coatings

After fifty times of back and forth movement (once for each time) of the ethanol-impregnated cotton swab over the sample containing the cured layer, the surface of the printed surface was visually observed after the ethanol was evaporated.

Samples with non-peeled printing surfaces were considered to have good chemical resistance (". smallcircle"), samples with small printing surfaces (< 50% area) peeled were considered to have general chemical resistance (". DELTA"), and samples with large printing surfaces (. gtoreq.50% area) peeled were considered to have poor chemical resistance (". xx").

(6) Evaluation of appearance of printed article

According to the GB/T7707-2008 intaglio decoration printing standard, intaglio printing with the depth of 10-18 mu m is adopted, and the printing after being placed for 24 hours is placed under a sample light source which meets the CY/T3 regulation, and is identified by visual inspection. The printed product is clean and tidy, and has no obvious ink stain, residue and knife thread; the characters are printed clearly and completely without incomplete deformation, and the characters smaller than 7.5P do not influence reading; the edge of the print printed on the spot is smooth and clean, the ink color is uniform, and no obvious water wave is generated; the printing level transition is stable without obvious gradation jump; the mesh points are clear and uniform, and have no obvious deformation or defect; the printing color meets the requirement of the printed sample sheet, namely the printed sample sheet is qualified; otherwise, if any is not ideal, the result is recorded as a fail.

The test results are shown in tables 3 and 4.

TABLE 3 printing Press line speed 150m/min

TABLE 4 printing Press line speed 220m/min

The test results show that the photocuring composition prepared by the technical scheme of the invention can meet the requirement of high-speed printing, the photocuring composition has good performances in the aspects of storage stability and curing speed, and various performances of the cured ink film are excellent.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A photo-curable ink is characterized by comprising an alicyclic epoxy compound, an oxetane compound and a photoinitiator; wherein,

the general formulas I, II, III, IV and R₁、R₂、R₃、R₄、R₅、R₆Each independently selected from hydrogen, methyl or ethyl, R₇、R₈、R₉、R₁₀、R₁₁、R₁₂、R₁₃、R₁₄、R₁₅Each independently selected from hydrogen, alkyl, alkenyl, arylAn alkyl group, an alkoxy group, a hydroxymethyl group, a hydroxyethyl group, a carboxyl group, a mercapto group, an amino group substituted with an alkyl group, an alkenyl group, an aryl group or an alkoxy group, an amide group, a nitro group, a cyano group, an acyl group, an ester group, an epoxy group, a heterocyclic structure-containing group or a halogen atom, and A is-CO-O-or-O-CO-.

2. The photocurable ink according to claim 1, wherein in the general formulae I, II, III, IV,

the alkyl is straight-chain alkyl, branched-chain alkyl or cycloalkyl; preferably, the linear alkyl group is methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-octyl or n-nonyl, the branched alkyl group is isopropyl, isobutyl, sec-butyl, tert-butyl or isooctyl, and the cycloalkyl group is cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclododecyl or norbornyl;

the alkenyl group is a straight-chain alkenyl group, a branched-chain alkenyl group or a cycloalkenyl group; preferably, the straight-chain alkenyl group is vinyl, n-butenyl, n-propenyl, n-pentenyl, n-hexenyl, n-octenyl or n-nonenyl, the branched alkenyl group is isopropenyl, isobutenyl, sec-butenyl, tert-butenyl or isooctenyl, and the cycloalkenyl group is cyclopentenyl, cyclohexenyl, cycloheptenyl, cyclooctenyl or norbornenyl;

the aryl group is a phenyl group or a substituted phenyl group, a naphthyl group or a substituted naphthyl group, and the substituent is the alkyl group, the alkenyl group, the alkoxy group, the hydroxymethyl group, the hydroxyethyl group, the carboxyl group, the mercapto group, the amino group, the amide group, the nitro group, the cyano group, the acyl group, the ester group or the epoxy group; preferably, the substituted phenyl group is a 2-fluorophenyl group, a 3-fluorophenyl group, a 4-fluorophenyl group, a 2-chlorophenyl group, a 3-chlorophenyl group, a 4-chlorophenyl group, a 2-bromophenyl group, a 2-methylphenyl group, a 4-methoxyphenyl group or a 4-acetylphenyl group;

the heterocyclic structure-containing group is an aziridine group, an oxirane group, an epithioethane group, an aziridine group, an oxirane group, a thioheteroarylene group, an azetidine group, an oxetane group, a thietane group, an azetidine group, a tetrahydropyrrole group, a tetrahydrofuran group, a tetrahydrothiophene group, a pyrrole group, a furan group, a thiol group, an azine group, a thiocyclopentane group, a pyridine group, a cyclohexylimine group, an epoxyhexane group, a thietane group, an azepine group, an oxaheptene group, an imidazole group, an imidazoline group, a pyrazine group, a morpholine group, a thiazine group, an indole group, an isoindole group, a benzimidazole group, a purine group, a quinoline group, an isoquinoline group, or a benzopyran group;

the halogen atom is fluorine, chlorine, bromine or iodine atom.

3. The photocurable ink according to claim 2, wherein the alicyclic epoxy compound comprises 1 to 99% by weight of the compound represented by formula I and 1 to 99% by weight of the compound represented by formula II.

4. The photocurable ink according to claim 3, wherein said cycloaliphatic epoxy compound comprises at least two of the compounds represented by the following structures:

5. the photocurable ink according to any of claims 1 to 4 wherein the oxetane compound is a monofunctional compound and/or a polyfunctional compound;

preferably, the monofunctional compound is 3-methyl-3-hydroxymethyloxetane, 3-ethyl-3- (hexyloxymethyl) oxetane, 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane, 3-ethyl-3- [ (phenoxy) methyl ] oxetane, 3-ethyl-3- (chloromethyl) oxetane, isobutoxymethyl (3-ethyl-3-oxetanylmethyl) ether, isobornyloxyethyl (3-ethyl-3-oxetanylmethyl) ether, isobornyl, One or more of 2-ethylhexyl (3-ethyl-3-oxetanylmethyl) ether, ethyldiethylene glycol (3-ethyl-3-oxetanylmethyl) ether;

preferably, the polyfunctional compound is bis [ 1-ethyl (3-oxetanyl) ] methyl ether, 3-bis (chloromethyl) oxetane, 3, 7-bis (3-oxetanyl) -5-oxa-nonane, 1, 2-bis [ (3-ethyl-3-oxetanylmethoxy) methyl ] ethane, 1, 3-bis [ (3-ethyl-3-oxetanylmethoxy) methyl ] propane, ethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, tricyclodecanediyldimethylene (3-ethyl-3-oxetanylmethyl) ether, trimethylolpropane tris (3-ethyl-3-oxetanylmethyl) ether, ethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, or a mixture thereof, 1, 4-bis [ (3-ethyl-3-oxetanylmethoxy) methyl ] benzene, 1, 4-bis (3-ethyl-3-oxetanylmethoxy) butane, 1, 6-bis (3-ethyl-3-oxetanylmethoxy) hexane, pentaerythritol tris (3-ethyl-3-oxetanylmethyl) ether, pentaerythritol tetrakis (3-ethyl-3-oxetanylmethyl) ether, polyethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol hexa (3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol penta (3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol tetra (3-ethyl-3-oxetanylmethyl) ether One or more of them.

6. The photocurable ink according to any one of claims 1 to 4 wherein the oxetane compound is the OXT-121, OXT-211, OXT-221, OXT-212 or OXT-610 of Toagosei.

7. The photo-curable ink according to any one of claims 1 to 4, wherein the photo-initiator is one or more of an iodonium salt, a sulfonium salt, an arylferrocenium salt; preferably, the photoinitiator comprises a compound of formula V and/or formula VI:

8. The photocurable ink according to claim 7 wherein R in said formula V₁And R₂Each independently represents hydrogen, C₁～C₁₂Straight or branched alkyl of (2), C₄～C₁₀Cycloalkylalkyl or alkylcycloalkyl of (A), and acyclic-CH in these groups₂-is optionally substituted by-O-; in the general formula VI, R₃And R₄Each independently represents hydrogen, C₁～C₁₀Straight or branched alkyl of (2), C₄～C₁₀Cycloalkylalkyl or alkylcycloalkyl, C₆～C₁₂And a substituted or unsubstituted aryl group of (A), and the acyclic-CH in these groups₂-optionally substituted by-O-, -S-or 1, 4-phenylene; r₅Represents C₆～C₁₀Substituted or unsubstituted aryl of (1), C₆～C₁₀Substituted or unsubstituted alkylaryl, substituted or unsubstituted thiophenylphenyl, and the acyclic-CH in these groups₂-optionally substituted by carbonyl, -O-, -S-or 1, 4-phenylene; r₆And R₇Each independently represents C₁～C₁₀Straight or branched alkyl of (2), C₁～C₁₀Linear or branched alkoxy of (C)₁～C₁₀Alkylcarbonyl and halogen.

9. The photo-curable ink according to claim 7,

the cationic portion of the iodonium salts and the sulfonium salts are selected from the following structures:

the anionic moieties of said iodonium salts and said sulfonium salts are selected from Cl^-、Br^-、PF₆ ^-、SbF₆ ^-、AsF₆ ^-、BF₄ ^-、C₄F₉SO₃ ^-、B(C₆H₅)₄ ^-、C₈F₁₇SO₃ ^-、CF₃SO₃ ^-、Al[OC(CF₃)₃]₄ ^-、(CF₃CF₂)₂PF₄ ^-、(CF₃CF₂)₃PF₃ ^-、[(CF₃)₂CF₂]₂PF₄ ^-、[(CF₃)₂CF₂]₃PF₃ ^-、[(CF₃)₂CFCF₂]₂PF₄ ^-Or (CF)₃)₂CFCF₂]₃PF₃ ^-；

10. The photo-curable ink according to any one of claims 1 to 9, further comprising a pigment; preferably, the content of the alicyclic epoxy compound in the photo-curable ink is 5-35% by weight, and more preferably 10-25% by weight; the content of the oxetane compound is 20-80%, and preferably 40-65%; the content of the photoinitiator is 0.1-10%, preferably 2-8%; the content of the pigment is 0.1-10%, preferably 2-8%.

11. The photo-curable ink according to claim 10, further comprising a sensitizer, preferably, the sensitizer is one or more of thioxanthone compounds, xanthone compounds, acridine compounds, anthracene compounds, coumarin compounds, pyrazoline compounds, naphthalene compounds, and tertiary amine compounds.

12. Use of a photo-curable ink according to any one of claims 1 to 11 as an ink film for paper, plastic, metal, glass articles.