Active energy ray-curable ink composition, method for producing active energy ray-curable ink composition, printing method using the same, and printed matter

Abstract

To provide an active energy ray-curable ink composition which is suitably applicable, e.g., to black ink that utilizes both carbon black and charcoal or bamboo charcoal, a method for producing the active energy ray-curable ink composition, a printing method using the same, and printed matter.SOLUTION: An active energy ray-curable ink composition is provided which comprises: (A) charcoal and / or bamboo charcoal with an average particle diameter of 5-100 μm; (B) carbon black; and (C) an epoxy (meth)acrylate resin comprising a triglyceride backbone.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an active energy ray-curable ink composition, a method for producing an active energy ray-curable ink composition, and a printing method and printed matter using the same. [Background technology]

[0002] In various printing fields, a printing method is adopted in which the ink composition present on the surface of a printed material is instantly dried by irradiating the printed material with active energy rays such as ultraviolet rays or electron beams immediately after printing. The ink composition used in this printing method contains, for example, a photopolymerization initiator that generates radicals or cations when irradiated with active energy rays, and a monomer or oligomer that reacts with these radicals or cations to polymerize, and when irradiated with active energy rays, the ink composition present on the surface of the printed material becomes a film-like cured product and is in a dry state.

[0003] As an example of such a technique, Patent Document 1 discloses an active energy ray-curable offset printing ink composition that contains a compound having an ethylenically unsaturated bond, a photopolymerization initiator, a colorant, and an extender pigment, and the median diameter (D50) of the extender pigment measured by a laser diffraction method is 1.0 μm to 2.0 μm. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-173070 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in recent years, there has been a demand for the above-mentioned printing inks to use biomass as the material. From this perspective, for example, methods have been attempted in which the oil component, which is the dispersion medium, is replaced from mineral oil to vegetable oil. In response to this demand for biomass, the present inventors have studied active energy ray-curable inks using carbon black. As a result, it has been found that the combined use of carbon black with charcoal or bamboo charcoal has not been fully studied, and the ink is not easy to manufacture, the required properties are not obtained to a level that can withstand practical use, or there is room for further improvement.

[0006] The present invention has been made in view of the above circumstances, and has an object to provide an active energy ray-curable ink composition that can be suitably used for black inks using carbon black in combination with charcoal or bamboo charcoal, a method for producing the active energy ray-curable ink composition, and a printing method and printed matter using the same. [Means for solving the problem]

[0007] As a result of further intensive research in order to achieve the above-mentioned object, the present inventors have discovered an active energy ray-curable ink composition containing (A) charcoal and / or bamboo charcoal having an average particle size of 5 to 100 μm, (B) carbon black, and (C) an epoxy (meth)acrylate resin containing a triglyceride skeleton, and have thus completed the present invention.

[0008] That is, the present invention is as follows.

[0009] (1) The active energy ray-curable ink composition contains (A) wood charcoal and / or bamboo charcoal having an average particle size of 5 to 100 μm, (B) carbon black, and (C) an epoxy (meth)acrylate resin containing a triglyceride skeleton. (2) The active energy ray-curable ink composition according to (1), wherein the component (A) is bamboo charcoal. (3) The active energy ray-curable ink composition according to (1) or (2), wherein the average particle size of the component (A) is 5 to 50 μm. (4) The active energy ray-curable ink composition according to (1) or (2), wherein the (C) epoxy (meth)acrylate resin containing a triglyceride skeleton is an epoxidized soybean oil (meth)acrylate resin. (5) The active energy ray-curable ink composition according to (1) or (2) further contains (D) a pigment dispersant. (6) The active energy ray-curable ink composition according to (1) or (2) further contains (E) a photopolymerization initiator. (7) The active energy ray-curable ink composition according to (1) or (2) further comprises (F) a compound having an ethylenically unsaturated group. (8) The method for producing an active energy ray-curable ink composition includes a step of kneading (A) wood charcoal and / or bamboo charcoal having an average particle size of 5 to 100 μm, (B) carbon black, and (C) an epoxy (meth)acrylate resin containing a triglyceride skeleton. (9) A printing method using an active energy ray-curable ink composition, comprising: a step of printing on an object using the active energy ray-curable ink composition according to (1) or (2); and a step of irradiating the active energy ray-curable ink composition printed on the object with active energy rays to cure the ink composition. (10) A printed matter obtained by the printing method described in (9). Effect of the Invention

[0010] According to the present invention, it is possible to provide an active energy ray-curable ink composition that can be suitably used for black inks that use carbon black in combination with charcoal and / or bamboo charcoal. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment for carrying out the present invention (hereinafter, simply referred to as "the present embodiment") will be described in detail. The present embodiment is an example for explaining the present invention, and is not intended to limit the present invention to the following content. The present invention can be carried out by appropriately modifying it within the scope of its gist.

[0012] In this specification, "(meth)acrylate" means "acrylate" and / or "methacrylate". "(meth)acrylic acid" means "acrylic acid" and / or "methacrylic acid". "(meth)acryloyl group" means "acryloyl group" and / or "methacryloyl group".

[0013] <Active energy ray curable ink composition>

[0014] The active energy ray-curable ink composition according to this embodiment is an active energy ray-curable ink composition (hereinafter, sometimes simply referred to as the "ink composition") that contains (A) wood charcoal and / or bamboo charcoal having an average particle size of 5 to 100 μm, (B) carbon black, and (C) an epoxy (meth)acrylate resin containing a triglyceride skeleton.

[0015] As described later, the ink composition according to the present embodiment can be cured by irradiation with active energy rays. For example, when the ink composition is irradiated with active energy rays, radicals generated in the ink composition polymerize compounds having ethylenic unsaturated bonds, oxetane structures, etc., thereby curing the ink composition. When the ink composition is irradiated with active energy rays and is sticky on the surface of a printed matter immediately after printing, the ink composition instantly cures to form a film and becomes dry (tack-free) (however, the effects of the present embodiment are not limited to these).

[0016] When ultraviolet light is used as the active energy ray, it is preferable to add a photopolymerization initiator, which will be described later, to the ink composition, so that the photopolymerization initiator undergoes intramolecular cleavage upon irradiation with ultraviolet light to generate radicals and thereby cure the ink composition.

[0017] When an electron beam is used as the active energy ray, various components contained in the ink composition can be irradiated with an electron beam to cause intramolecular cleavage, thereby generating radicals and curing the ink composition. In this way, when an electron beam is selected as the active energy ray, the ink composition does not need to contain a photopolymerization initiator.

[0018] Examples of active energy rays used to cure the ink composition include ultraviolet rays, electron beams, etc. Among these, from the viewpoints of the cost and ease of handling of the device, ultraviolet rays are preferred as the active energy rays, but in recent years, the introduction of electron beam generators into printing devices has also progressed, and from this viewpoint, electron beams are also preferred as active energy rays.

[0019] When ultraviolet rays are used as the active energy rays, the wavelength may be appropriately determined according to the absorption wavelength of the photopolymerization initiator used, and may be 400 nm or less. Examples of ultraviolet ray irradiation devices that generate such ultraviolet rays include metal halide lamps, high pressure mercury lamps, excimer lamps containing rare gas, and ultraviolet light emitting diodes (LEDs). When electron beams are used as the active energy rays, the irradiation device that irradiates the electron beams is not particularly limited. Examples of such irradiation devices include Cockcroft-Waldsin type, Van de Graaff type, and resonant transformer type irradiation devices.

[0020] The energy of the electron beam may be appropriately determined depending on the components used, but is preferably 50 to 1000 eV, and more preferably 100 to 300 eV. Regardless of which active energy ray is used, the amount of irradiation can be appropriately adjusted while observing the degree of curing of the ink composition.

[0021] The printing method to which the ink composition according to the present embodiment is applied is not particularly limited. Examples of such printing methods include offset printing, waterless offset printing, letterpress printing, rubber relief printing, flexographic printing, gravure printing, and inkjet printing. The properties of the ink composition, such as viscosity, may be appropriately set according to the printing method to which the ink composition is applied. Among these, the printing methods to which the present embodiment is applied are preferably offset printing and waterless offset printing.

[0022] Hereinafter, each component that can be used in the active energy ray-curable ink composition according to this embodiment will be described by way of example.

[0023] (Component (A))

[0024] The component (A) is charcoal and / or bamboo charcoal having an average particle size of 5 to 100 μm. The average particle size of the component (A) is preferably 5 to 50 μm. The upper limit of the average particle size of the component (A) is preferably 50 μm or less, more preferably 40 μm or less, and even more preferably 30 μm or less. On the other hand, the lower limit of the average particle size is preferably 7 μm or more. By setting the average particle size in such a range, the kneading suitability and the particle size of the ink composition can be further improved. The average particle size can be measured by a laser diffraction / scattering method, and can be measured using the "Microtrac" series of Microtrac Bell Co., Ltd. In the case of a commercially available product, the catalog data of the commercially available product is used as a priority.

[0025] As the component (A), charcoal and / or bamboo charcoal can be used. Specific examples of charcoal include, but are not limited to, black charcoal, white charcoal, and sawdust charcoal. Specific examples of bamboo charcoal include, but are not limited to, bamboo charcoal obtained by carbonizing bamboo such as Madake bamboo and Moso bamboo at high temperatures (for example, 650 to 1000°C). Among these, bamboo charcoal is preferable from the viewpoint of availability.

[0026] As the component (A), the above-mentioned compounds may be used alone or in combination of two or more.

[0027] The content of component (A) in the ink composition is preferably 3 to 30% by mass. The upper limit of this content is more preferably 25% by mass or less, even more preferably 20% by mass or less, and even more preferably 15% by mass or less. The lower limit of this content is more preferably 5% by mass or more, and even more preferably 7% by mass or more. By keeping the content of component (A) within this range, it is possible to further improve the biomass degree while ensuring suitability for kneading.

[0028] ((B) component)

[0029] Component (B) is carbon black. Specific examples of carbon black include thermal black obtained by a thermal method, lamp black obtained by the oil smoke method (lamp method) or pine smoke method obtained from the smoke generated when burning oil or pine, channel black obtained from natural gas or the like, furnace black obtained from petroleum-based or coal-based oil, and acetylene black obtained by thermal decomposition of acetylene gas. Note that the carbon black used as component (B) may be one other than charcoal or bamboo charcoal.

[0030] The primary particle diameter of the carbon black is not particularly limited, but is preferably 15 to 40 nm. The lower limit of the primary particle diameter is more preferably 20 nm or more. The upper limit of the primary particle diameter is more preferably 30 nm or less. As described later, a commercially available product can be used as the component (B), and in this case, the primary particle diameter is determined by giving priority to the catalog data of the commercially available product.

[0031] The content of the (B) component in the ink composition is preferably 10 to 25% by mass. The upper limit of this content is more preferably 20% by mass or less. The lower limit of this content is more preferably 13% by mass or more. By keeping the content of the (B) component in this range, the density of the obtained image is further improved.

[0032] The specific surface area of ​​the carbon black is not particularly limited, but is preferably 80 to 150 m 2 / g. The lower limit of the specific surface area is 100 m 2 / g or more. The upper limit of the specific surface area is 130 m 2 / g or less is more preferable. By having the specific surface area in this range, it is possible to further improve the scratch resistance and solid filling of the colored image, as well as the prevention of mottling. This specific surface area refers to the nitrogen adsorption specific surface area measured in accordance with JIS K6217.

[0033] As the carbon black, for example, commercially available products can be used, such as "MA7", "MA70", "MA77", "MA8", "MA11", "MA100", and "MA220" manufactured by Mitsubishi Carbon Black Co., Ltd.

[0034] ((C) component)

[0035] The component (C) is an epoxy (meth)acrylate resin containing a triglyceride skeleton. The component (C) is preferably an epoxidized vegetable oil (meth)acrylate resin obtained by (meth)acrylic modification of an epoxidized vegetable oil. Examples of this include compounds obtained by ring-opening addition polymerization of (meth)acrylic acid to the epoxy groups of an epoxidized vegetable oil in which the double bonds of the unsaturated vegetable oil are epoxidized with an oxidizing agent such as peracetic acid or perbenzoic acid. In the case of an unsaturated vegetable oil, it may be a triglyceride in which at least one fatty acid has at least one carbon-carbon unsaturated bond, or it may be a partial structure of an unsaturated vegetable oil rather than a glyceride.

[0036] As the epoxy (meth)acrylate resin containing a triglyceride skeleton, the lower limit of the number of functional groups is preferably 2 or more, and more preferably 3 or more. The upper limit of the number of functional groups is preferably 6 or less, and more preferably 4 or less.

[0037] Examples of the above-mentioned vegetable oils include hemp seed oil, linseed oil, perilla oil, oiticica oil, olive oil, cacao oil, kapok oil, kaya oil, mustard oil, apricot kernel oil, tung oil, kukui oil, walnut oil, poppy seed oil, sesame oil, safflower oil, radish seed oil, soybean oil, radish seed oil, camellia oil, corn oil, rapeseed oil, niger oil, rice bran oil, palm oil, castor oil, sunflower oil, grape seed oil, almond oil, pine seed oil, cottonseed oil, coconut oil, peanut oil, dehydrated castor oil, tall oil, etc. For example, in the case of soybean oil, epoxylated soybean oil (meth)acrylate resin, etc. are mentioned as a suitable example.

[0038] The vegetable oil modified (meth)acrylate compound is derived from vegetable oil, and is useful for increasing the amount of biomass components in the ink composition. In addition, a (meth)acrylate compound modified with animal oil may be used. Furthermore, various types of epoxidized vegetable oil (meth)acrylates are commercially available, and these may be used.

[0039] In consideration of the environmental aspect, a polyurethane oligomer and / or a polyurethane polyurea oligomer made from a polyester polyol obtained by using a dicarboxylic acid component or a diol component derived from a plant can also be used. As the vegetable oil-modified polyfunctional polyurethane acrylate oligomer, a vegetable oil-modified polyurethane acrylate oligomer having 2 to 6 acrylate groups in the molecule can be preferably used.

[0040] The above-mentioned resins may be used alone or in combination of two or more kinds.

[0041] The content of component (C) in the ink composition is preferably 3 to 30% by mass. The upper limit of this content is more preferably 25% by mass or less, even more preferably 20% by mass or less, and even more preferably 15% by mass or less. The lower limit of this content is more preferably 4% by mass or more, and even more preferably 5% by mass or more. By having the content of component (C) in this range, the density of the obtained image is further improved.

[0042] ((D) component)

[0043] The active energy ray-curable ink composition according to this embodiment preferably further contains (D) a pigment dispersant. The dispersant is suitably used to disperse the coloring component and the extender pigment contained in the ink composition in a good state. The type of dispersant is not particularly limited, and a suitable type can be appropriately selected in consideration of the types of other components such as the components (A) to (C).

[0044] Examples of the pigment dispersant include a surfactant and a polymer dispersant.

[0045] The surfactant usable as the pigment dispersant may be, for example, one or more selected from the group consisting of known nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants. Specific examples of the surfactant include, for example, silicon-based surfactants (e.g., polyether-modified silicon oil, polyester-modified polydimethylsiloxane, polyester-modified methylalkylpolysiloxane, etc.), fluorine-based surfactants, oxyalkylene ether-based surfactants, acetylene glycol-based surfactants, phosphorus-based surfactants, sulfonic acid-based surfactants, etc.

[0046] Specific examples of polymer dispersants that can be used as pigment dispersants include carbodiimide-based dispersants, polyester-based dispersants, polyamine-based dispersants, polyester amine-based dispersants, polyurethane-based dispersants, fatty acid amine-based dispersants, polyacrylate-based dispersants, polycaprolactone-based dispersants, polysiloxane-based dispersants, multi-chain polymer nonionic dispersants, and polymer ionic dispersants.

[0047] Among these, polyamine-based dispersants are preferred.

[0048] The base number of the polymer dispersant is not particularly limited, but is preferably 10 to 50 mgKOH / g. The lower limit of the base number is more preferably 20 mgKOH / g or more, and even more preferably 25 mgKOH / g or more. The upper limit of the base number is more preferably 40 mgKOH / g or less, and even more preferably 35 mgKOH / g or less.

[0049] The base number can be measured in accordance with the potentiometric titration method (base number-perchloric acid method) specified in JIS K2501:2003. Specifically, the amount of perchloric acid required to neutralize the basic components contained in 1 g of sample is measured, and the amount can be expressed as the number of milligrams of potassium hydroxide (KOH) equivalent to that perchloric acid. Commercially available polymer dispersants can be used. In the case of commercially available polymer dispersants, the catalog data of the commercially available product is used as the base number.

[0050] In addition, commercially available polymer dispersants can also be used, such as the Solsperse series manufactured by Lubrizol Japan and the DISPERBYK series manufactured by BYK Japan.

[0051] The above-mentioned pigment dispersants may be used alone or in combination of two or more kinds.

[0052] The content of the (D) component in the ink composition is preferably 1 to 10% by mass. The upper limit of this content is more preferably 8% by mass or less, even more preferably 6% by mass or less, and even more preferably 4% by mass or less. The lower limit of this content is more preferably 2% by mass or more. By keeping the content of the (D) component in this range, the density of the obtained image is further improved.

[0053] Furthermore, when the ink composition contains component (D), it is preferable that the component (D) is contained in an amount of 1 to 200 mass % when the total amount of components (A), (B), and other pigments used is taken as 100 mass %.

[0054] ((E) component)

[0055] The active energy ray-curable ink composition according to this embodiment preferably further contains a photopolymerization initiator (E). In particular, when the active energy ray is ultraviolet light, it is preferable to contain the component (E). The type of the component (E) is not particularly limited, and a suitable type can be appropriately selected in consideration of the types of the components (A) to (C) and other components such as monomers.

[0056] The (E) photopolymerization initiator is a component that generates radicals when irradiated with active energy rays, and the generated radicals polymerize compounds having ethylenically unsaturated bonds, etc., to cure the ink composition. Specific examples of the (E) component include one or more compounds selected from the group consisting of acylphosphine oxide compounds, triazine compounds, aromatic ketone compounds, aromatic onium salt compounds, organic peroxides, thioxanthone compounds, thiophenyl compounds, anthracene compounds, hexaarylbiimidazole compounds, ketoxime ester compounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds, halogenated hydrocarbon compounds, alkylamine compounds, iodonium salt compounds, and sulfonium salt compounds.

[0057] Specific examples of the photopolymerization initiator include benzophenone, 4,4'-bis(diethylamino)benzophenone, diethylthioxanthone, 2-methyl-1-(4-methylthio)phenyl-2-morpholinopropan-1-one, 4-benzoyl-4'-methyldiphenyl sulfide, 1-chloro-4-propoxythioxanthone, isopropylthioxanthone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexylphenyl ketone, bis-2 ,6-dimethoxybenzoyl-2,4,4-trimethylpentylphosphine oxide, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2,2-dimethyl-2-hydroxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,4,6-trimethylbenzyl-diphenylphosphine oxide, 2-benzyl-2-dimethylamino-1-(morpholinophenyl)-butan-1-one, and the like.

[0058] As the (E) photopolymerization initiator, for example, a commercially available product can be used, such as Omnirad907, Omnirad369, Omnirad184, Omnirad379, Omnirad819, Omnirad TPO, etc. manufactured by IGM Resins BV, or DETX, etc. manufactured by Lamberti.

[0059] The above-mentioned photopolymerization initiators may be used alone or in combination of two or more kinds.

[0060] The total content of the (E) component in the ink composition is preferably 1 to 20% by mass. The upper limit of this content is more preferably 15% by mass or less, even more preferably 13% by mass or less, and even more preferably 10% by mass or less. The lower limit of this content is more preferably 3% by mass or more, even more preferably 5% by mass or more, and even more preferably 7% by mass or more. By keeping the content of the (E) component within this range, the density of the obtained image is further improved.

[0061] (Component (F))

[0062] The active energy ray curable ink composition according to the present embodiment preferably further contains (F) a compound having an ethylenically unsaturated group or an oxetane structure. The component (F) is more preferably a compound having an ethylenically unsaturated group. The component (F) is a component that is polymerized by radicals generated by a photopolymerization initiator to increase the molecular weight, and includes components called monomers and oligomers. Here, a polymer having an ethylenically unsaturated bond or an oxetane structure is also considered as a compound that increases the molecular weight like these monomers and oligomers, but the difference between a polymer and an oligomer is only the size of the molecular weight, and such a polymer is also similar to an oligomer in that it polymerizes with other molecules having an ethylenically unsaturated bond or an oxetane structure, so in the present embodiment, the term oligomer having an ethylenically unsaturated bond or an oxetane structure may be used as a concept including these oligomers and polymers. Hereinafter, specific examples of a compound having an ethylenically unsaturated bond will be described as an example.

[0063] For example, when the component (F) is a monomer having an ethylenically unsaturated bond, this is a component that has an ethylenically unsaturated bond and is polymerized to a high molecular weight as described above, but since it is a component with a relatively low molecular weight, it is used, for example, as a solvent when dissolving a resin component to make a varnish, or for the purpose of adjusting the viscosity of the ink composition. Examples of the monomer include monofunctional monomers having one ethylenically unsaturated bond in the molecule, and difunctional or higher monomers having two or more ethylenically unsaturated bonds in the molecule. Difunctional or higher monomers can crosslink molecules when the ink composition is cured, so they contribute to accelerating the curing speed and forming a strong film. Monofunctional monomers do not have the above-mentioned crosslinking ability, but contribute to reducing the curing shrinkage associated with crosslinking. These monomers can be used in combination with various types as necessary.

[0064] Examples of the monofunctional monomer include monofunctional monomers containing a (meth)acryloyl group. Specific examples of the monofunctional monomer include alkyl (meth)acrylates such as (meth)methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, and dodecyl (meth)acrylate, (meth)acrylic acid, (meth)acrylates of ethylene oxide adducts, (meth)acrylates of propylene oxide adducts, isobornyl (meth)acrylate, cyclohexyl (meth)acrylate, and tetramethyl (meth)acrylate. Licyclodecane monomethylol (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, hydroxypentyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-hydroxy-3-butoxypropyl (meth)acrylate, 2-hydroxy-3 2-methoxypropyl (meth)acrylate, diethylene glycol mono(meth)acrylate, triethylene glycol mono(meth)acrylate, polyethylene glycol mono(meth)acrylate, dipropylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, glycerin mono(meth)acrylate, acryloyloxyethyl phthalate, 2-(meth)acryloyloxyethyl-2-hydroxyethyl phthalate, 2-(meth)acryloyloxypropyl phthalate, β-carboxyethyl (meth)acrylate, (meth)acrylic acid dimer, ω-carboxypolycaprolactone mono(meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, N-vinylpyrrolidone, N-vinylformamide, (meth)acryloylmorpholine, N-vinylacetamide, N-vinylcaprolactam, N-vinylcarbazole, vinylmethyloxazolidinone, and the like. These monofunctional monomers may be used alone or in combination of two or more kinds.

[0065] Examples of the difunctional or higher functional monomer include difunctional or higher functional monomers containing a (meth)acryloyl group. Specific examples of the difunctional or higher functional monomer include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, pentyl Glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, hydroxypivalyl hydroxypivalate di(meth)acrylate, hydroxypivalyl hydroxypivalate dicaprolactonate di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,2-hexanediol di(meth)acrylate, 1,5-hexanediol di(meth)acrylate, 2,5-hexanediol di(meth)acrylate, 1,7-heptanediol di(meth)acrylate , 1,8-octanediol di(meth)acrylate, 1,2-octanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,2-decanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,2-decanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, 1,2-dodecanediol di(meth)acrylate, 1,14-tetradecanediol di(meth)acrylate, 1,2-tetradecanediol di(meth)acrylate, ol di(meth)acrylate, 1,16-hexadecanediol di(meth)acrylate, 1,2-hexadecanediol di(meth)acrylate, 2-methyl-2,4-pentanediol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 2-methyl-2-propyl-1,3-propanediol di(meth)acrylate, 2,4-dimethyl-2,4-pentanediol di(meth)acrylate, 2,2-diethyl-1,3-propanediol di(meth)acrylate,2,2,4-trimethyl-1,3-pentanediol di(meth)acrylate, dimethylol octane di(meth)acrylate, 2-ethyl-1,3-hexanediol di(meth)acrylate, 2,5-dimethyl-2,5-hexanediol di(meth)acrylate, 2-methyl-1,8-octanediol di(meth)acrylate, 2-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, 2,4-diethyl-1,5-pentanediol di(meth)acrylate, 1,2-hexanediol di(meth)acrylate, 1, 5-Hexanediol di(meth)acrylate, 2,5-Hexanediol di(meth)acrylate, 1,7-Heptanediol di(meth)acrylate, 1,8-Octanediol di(meth)acrylate, 1,2-Octanediol di(meth)acrylate, 1,9-Nonanediol di(meth)acrylate, 1,2-Decanediol di(meth)acrylate, 1,10-Decanediol di(meth)acrylate, 1,2-Decanediol di(meth)acrylate, 1,12-Dodecanediol di(meth)acrylate, 1,2-Dodecanediol di(meth)acrylate, 1,14-tetradecanediol di(meth)acrylate, 1,2-tetradecanediol di(meth)acrylate, 1,16-hexadecanediol di(meth)acrylate, 1,2-hexadecanediol di(meth)acrylate, 2-methyl-2,4-pentanediol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 2-methyl-2-propyl-1,3-propanediol di(meth)acrylate, 2,4-dimethyl-2,4-pentanediol di(meth)acrylate, 2 ,2-diethyl-1,3-propanediol di(meth)acrylate, 2,2,4-trimethyl-1,3-pentanediol di(meth)acrylate, dimethylol octane di(meth)acrylate, 2-ethyl-1,3-hexanediol di(meth)acrylate, 2,5-dimethyl-2,5-hexanediol di(meth)acrylate, 2-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, 2,4-diethyl-1,5-pentanediol di(meth)acrylate tricyclodecane dimethylol di(meth)acrylate,Tricyclodecane dimethylol dicaprolactonate di(meth)acrylate, bisphenol A tetraethylene oxide adduct di(meth)acrylate, bisphenol F tetraethylene oxide adduct di(meth)acrylate, bisphenol S tetraethylene oxide adduct di(meth)acrylate, hydrogenated bisphenol A tetraethylene oxide adduct di(meth)acrylate, hydrogenated bisphenol F tetraethylene oxide adduct di(meth)acrylate, hydrogenated bisphenol A di(meth)acrylate, hydrogenated bisphenol Bifunctional monomers such as bisphenol F di(meth)acrylate, bisphenol A tetraethylene oxide adduct dicaprolactonate di(meth)acrylate, and bisphenol F tetraethylene oxide adduct dicaprolactonate di(meth)acrylate; glycerin tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolpropane tricaprolactonate tri(meth)acrylate, trimethylolethane tri(meth)acrylate, trimethylolhexane tri(meth)acrylate, and trimethylol Trifunctional monomers such as octane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, and tri(meth)acrylate of an ethylene oxide 3-mol adduct of trimethylolpropane; trimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, pentaerythritol tetracaprolactonate tetra(meth)acrylate, diglycerol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, and ditrimethylolpropane tetracaprolactonate dipentaerythritol tetra(meth)acrylate, ditrimethylolethane tetra(meth)acrylate, ditrimethylolbutane tetra(meth)acrylate, ditrimethylolhexane tetra(meth)acrylate, ditrimethyloloctane tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tripentaerythritol hexa(meth)acrylate, tripentaerythritol hepta(meth)acrylate, tripentaerythritol octa(meth)acrylate,Examples of the monomer include tetrafunctional or higher monomers such as tripentaerythritol polyalkylene oxide hepta(meth)acrylate.

[0066] Among these, preferred examples include trimethylolpropane tri(meth)acrylate (TMPTA, TMPTM; trifunctional), tri(meth)acrylate of ethylene oxide 3 mole adduct of trimethylolpropane (TMP(EO)3TA, TMP(EO)3TM; trifunctional), ditrimethylolpropane tetraacrylate (DITMPTA; tetrafunctional), dipentaerythritol hexa(meth)acrylate (DPHA, DPHM; hexafunctional), glycerin propoxy tri(meth)acrylate (GPTA, GPTM; trifunctional), hexanediol di(meth)acrylate (HDDA, HDDM; bifunctional), etc. These difunctional or higher monomers may be used alone or in combination of two or more.

[0067] As described above, the oligomer is a component that polymerizes to a high molecular weight, but since it is a relatively high molecular weight component, it is also used for the purpose of imparting suitable viscosity and elasticity to the ink composition. Examples of the oligomer include epoxy-modified (meth)acrylates exemplified by esters of hydroxyl groups and (meth)acrylic acid generated after ring-opening of epoxy groups contained in epoxy compounds such as epoxy resins with an acid or base, rosin-modified epoxy acrylates, polyester-modified (meth)acrylates exemplified by esters of terminal hydroxyl groups and (meth)acrylic acid in condensation polymers of dibasic acids and diols, polyether-modified (meth)acrylates exemplified by esters of terminal hydroxyl groups and (meth)acrylic acid in polyether compounds, and urethane-modified (meth)acrylates exemplified by esters of terminal hydroxyl groups and (meth)acrylic acid in condensation polymers of polyisocyanate compounds and polyol compounds. Such oligomers are commercially available, and examples thereof include the Ebecryl series manufactured by Daicel-Cytec Co., Ltd., the CN and SR series manufactured by Sartomer Co., Ltd., the Aronix M-6000 series, 7000 series, 8000 series, Aronix M-1100, Aronix M-1200, and Aronix M-1600 manufactured by Toagosei Co., Ltd., and the NK Oligo manufactured by Shin-Nakamura Chemical Co., Ltd. These oligomers may be used alone or in combination of two or more kinds.

[0068] The total content of the (F) component in the ink composition is preferably 5 to 40% by mass. The upper limit of this content is more preferably 35% by mass or less, even more preferably 32% by mass or less, and even more preferably 30% by mass or less. The lower limit of this content is more preferably 13% by mass or more, even more preferably 17% by mass or more, and even more preferably 20% by mass or more. By keeping the content of the (F) component within this range, the balance between good curability and good printability can be further improved.

[0069] Furthermore, the ratio, by mass, of the total amount of monomers to the total amount of oligomers in the ink composition is preferably monomer:oligomer=8:1 to 1:1, more preferably monomer:oligomer=7:1 to 1:1, and even more preferably monomer:oligomer=6:1 to 1:1. By having the monomer:oligomer ratio within the above range, good curability and printability can be achieved at an even higher level.

[0070] (Other Ingredients)

[0071] In addition to the above-mentioned components, other components may be added to the active energy ray curable ink composition according to the present embodiment as necessary, but may not be included. Also, necessary components may be added according to the printing method and application method. Examples of such components include extender pigments, non-curable resin components, polymerization inhibitors, salts such as phosphates, PTFE, waxes such as polyethylene waxes, olefin waxes, and Fischer-Tropsch waxes, defoamers, alcohols, and oil components such as vegetable oils and mineral oils.

[0072] The other components will now be described by way of example.

[0073] The extender pigment is a component for imparting suitable printability, viscoelasticity, and other properties to the ink composition, and various types of extender pigments that are commonly used in the preparation of ink compositions can be used. Examples of such extender pigments include clay, kaolinite (kaolin), barium sulfate, magnesium sulfate, calcium carbonate, silicon oxide (silica), bentonite, talc, mica, titanium oxide, and the like.

[0074] The content of the extender pigment in the ink composition is preferably 0 to 20% by mass. The upper limit of this content is more preferably 10% by mass or less, even more preferably 5% by mass or less, and even more preferably 4% by mass or less. The lower limit of this content is more preferably 0.5% by mass or more, even more preferably 1% by mass or more, and even more preferably 1.5% by mass or more. By keeping the content of the extender pigment within this range, the density of the obtained image is further improved.

[0075] The non-curable resin component is a component that contributes to imparting suitable properties such as printability and viscoelasticity to the active energy ray-curable ink composition according to this embodiment, and does not have unsaturated bonds that contribute to polymerization.

[0076] Examples of such a resin component include various resins that have been conventionally used in printing ink compositions.

[0077] It is preferable that the resin has compatibility with the above-mentioned monomers and oligomers, and one or more selected from the group consisting of styrene-acrylic resin, acrylic resin, styrene-maleic acid resin, polyester resin, alkyd resin, rosin-modified phenolic resin, rosin-modified maleic acid resin, rosin-modified alkyd resin, rosin-modified petroleum resin, rosin ester resin, phenolic resin, rosin resin, block polymer, graft polymer (core-shell polymer), acrylic-modified phenolic resin, petroleum resin-modified phenolic resin, vegetable oil-modified alkyd resin, fatty acid-modified rosin resin, petroleum resin-modified phenolic resin, terpene phenolic resin, petroleum resin, hydrocarbon resin (polybutene and polybutadiene, etc.), fluorine resin (tetrafluoroethylene (PTFE) resin wax, etc.) can be used. Particularly preferably, one or more selected from the group consisting of styrene-acrylic resin, alkyd resin, rosin-modified phenolic resin, rosin-modified maleic acid resin, rosin-modified alkyd resin, rosin ester resin, fatty acid-modified rosin resin, vegetable oil-modified alkyd resin, and terpene phenolic resin can be used. Among these, rosin-modified maleic acid resin and terpene phenol resin are preferred from the viewpoint of adhesiveness.

[0078] In the ink composition according to the present embodiment, the content of the non-curable resin in the solid content is preferably 5 to 50% by mass. The upper limit is more preferably 40% by mass or less, and even more preferably 30% by mass or less. The lower limit is more preferably 10% by mass or more, and even more preferably 20% by mass or more. By setting the content of the non-curable resin within this range, it is possible to impart appropriate viscoelasticity to the ink composition without impairing good curability by electron beams, thereby suppressing the occurrence of misting, etc., which is preferable. In the ink composition according to the present embodiment, the use of a fatty acid modified rosin resin or a rosin modified alkyd resin as the non-curable resin can improve properties such as the biomass degree.

[0079] The active energy ray curable ink composition may contain a known polymerization inhibitor for the purpose of preventing polymerization during storage. When the active energy ray curable ink composition does not contain a polymerization initiator, the ink composition may not contain a polymerization inhibitor. Examples of the polymerization inhibitor include phenol compounds such as butylhydroxytoluene, tocopherol acetate, nitrosamine, benzotriazole, hindered amine, and hindered phenol compounds (e.g., pentaerythritol=tetrakis[3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate]). By adding such a polymerization inhibitor, the ink composition can be prevented from thickening due to the polymerization reaction during storage. The content of the polymerization inhibitor in the ink composition can be about 0.05 to 1% by mass.

[0080] (wax)

[0081] As the wax, from the viewpoint of improving scratch resistance, wax that can be used in printing inks can be used.

[0082] Specific examples of such wax include animal and vegetable waxes such as beeswax, lanolin wax, spermaceti, candelilla wax, carnauba wax, rice wax, Japan wax, and jojoba oil, minerals such as montan wax, ozogelite, ceresin, paraffin wax, microcrystalline wax, and petrolatum, petroleum wax, synthetic hydrocarbon waxes such as Fischer-Tropsch wax, polyethylene wax, oxidized polyethylene wax, and oxidized polypropylene wax, modified waxes such as montan wax derivatives, paraffin wax derivatives, and microcrystalline wax derivatives, hydrogenated waxes such as hydrogenated castor oil and hydrogenated castor oil derivatives, and polytetrafluoroethylene wax. Among these, polyethylene wax and polytetrafluoroethylene wax are preferred from the viewpoint of frictional properties.

[0083] The average particle size of the wax is not particularly limited and may be appropriately selected depending on the viscosity of the ink composition, etc., but is preferably 8 μm or less, more preferably 6 μm or less, and even more preferably 4 μm or less, and from the viewpoint of scratch resistance, is even more preferably 1 to 2 μm.

[0084] The wax content in the ink composition is preferably 0 to 10% by mass. The upper limit of this content is more preferably 8% by mass or less, even more preferably 5% by mass or less, and even more preferably 3% by mass or less. The lower limit of this content is more preferably 0.5% by mass or more, and even more preferably 0.8% by mass or more. By keeping the wax content within this range, the scratch resistance and friction resistance are improved, and the balance of the ink transferability is further improved.

[0085] (solvent)

[0086] The active energy ray-curable ink composition according to this embodiment may contain a known solvent in order to lower the viscosity and improve the wetting and spreading properties on the substrate.

[0087] Examples of the solvent include water, glycol monoacetates, glycol diacetates, glycol ethers, lactate esters, etc. Among these, water, tetraethylene glycol dialkyl ether, ethylene glycol monobutyl ether acetate, and diethyl diglycol are preferred.

[0088] When the active energy ray-curable ink composition according to this embodiment contains a solvent, the content thereof can be set to 0 to 50.0 mass %.

[0089] (Surface conditioner)

[0090] The active energy ray-curable ink composition according to this embodiment may contain a known surface conditioner. Examples of the surface conditioner that can be used include silicon-based surface conditioners, fluorine-based surface conditioners, acrylic surface conditioners, and acetylene glycol surface conditioners.

[0091] The surface conditioner may be a commercially available product, such as the BYK series from BYK Chemie, the TEGO series from Evonik Degussa Japan, or the Polyflow series from Kyoeisha Chemical.

[0092] The content of the surface conditioner is not particularly limited, but can be set to 0.01 to 1.0 mass %.

[0093] <Method for producing active energy ray-curable ink composition>

[0094] A known method can be used as a method for producing the active energy ray curable ink composition according to this embodiment. A suitable example is a method for producing an active energy ray curable ink composition, which includes a step of kneading (A) wood charcoal and / or bamboo charcoal having an average particle size of 5 to 100 μm, (B) carbon black, and (C) an epoxy (meth)acrylate resin containing a triglyceride skeleton. In addition to the components (A) to (C), the other components described above can also be kneaded appropriately. The kneading method is not particularly limited, and for example, a method of adding all the components and mixing them with a three-roll mill or a bead mill can be used.

[0095] The manufacturing method according to the present embodiment is not particularly limited in its operation method, and may be, for example, a batch type or a continuous type, but is preferably a batch type. The manufacturing method according to the present embodiment has at least advantages in terms of manufacturing process such as kneading property and pigment dispersion processability, and is also a manufacturing method that can reduce the number of passes. That is, the manufacturing method according to the present embodiment can reduce the number of kneading steps and shorten the kneading time in the case of a batch type.

[0096] Alternatively, a concentrated base may be prepared in advance by mixing the pigment, the pigment dispersant, and various electron beam curable compounds, and then the electron beam curable compound, the polymerization initiator, and other additives as necessary may be added to the concentrated base to obtain the desired composition.

[0097] In addition, after mixing the above-mentioned components, the mixture may be milled in a bead mill or a three-roll mill to disperse the pigments (i.e., color pigments and extender pigments), and additives (polymerization initiators, polymerization inhibitors, waxes, and other additives, etc.) may be added as necessary, and the viscosity may be adjusted by adding other components.

[0098] The viscosity of the active energy ray-curable ink composition according to this embodiment can be appropriately adjusted depending on the application, conditions of use, and the like, and is not particularly limited, but is, for example, 2000 mPa·s or less, preferably 1500 mPa·s or less, and more preferably 400 to 1500 mPa·s.

[0099] The substrate to which the active energy ray-curable ink composition according to this embodiment is printed and applied may be plastic, paper, carton, or the like, or may be a composite substrate such as a laminate composed of a plurality of these substrates.

[0100] Among these, examples of plastic substrates on which the active energy ray-curable ink composition according to the present embodiment is printed or coated include polyester-based polymers (e.g., polyethylene terephthalate (PET), polyethylene naphthalate, etc.), cellulose-based polymers (e.g., diacetyl cellulose, triacetyl cellulose (TAC), etc.), polycarbonate-based polymers, polyacrylic-based polymers (e.g., polymethyl methacrylate, etc.), vinyl chloride-based polymers, polyolefin-based polymers (e.g., polyethylene, polypropylene, polyolefin polymers having a cyclic or norbornene structure, ethylene-propylene copolymer polymers, etc. ), polyamide-based polymers (e.g., nylon, aromatic polyamide polymers, etc.), polystyrene-based polymers (e.g., polystyrene, acrylonitrile-styrene copolymers, etc.), polyimide-based polymers, polysulfone-based polymers, polyethersulfone-based polymers, polyetherketone-based polymers, polyphenylsulfide-based polymers, polyvinyl alcohol-based polymers, polyvinylidene chloride-based polymers, polyvinyl butyral-based polymers, polyarylate-based polymers, polyoxymethylene-based polymers, and polyepoxy-based polymers, as well as blends of these polymers, can be used.

[0101] <Printing method, printed matter>

[0102] To print using the active energy ray curable ink composition according to this embodiment, a known printing method and curing conditions for the active energy ray curable ink composition can be adopted. A suitable example of the printing method is a printing method using an active energy ray curable ink composition, which includes a step of printing an object using the above-mentioned active energy ray curable ink composition, and a step of curing the active energy ray curable ink composition printed on the object by irradiating it with active energy rays. A printed matter can be obtained by curing the active energy ray curable ink composition. In addition, a cured matter can be obtained by curing the active energy ray curable ink composition by irradiating it with active energy rays.

[0103] By the above-mentioned printing method, a printed matter can be obtained by printing on an object. Examples of the object include objects used for various printing such as printing on forms, printing on various books, printing on various packaging materials such as carton paper, printing on various plastics, printing on stickers and labels, fine art printing, and metal printing (fine art printing, printing on beverage cans, printing on canned foods, etc.).

[0104] As described above, according to the present embodiment, it is possible to provide an active energy ray-curable ink composition that can be suitably used for black inks using carbon black in combination with charcoal or bamboo charcoal. For example, it is possible to provide an ink composition having suitable kneading suitability and particle size as an ink. Such an ink composition also contributes to the recent demand for biomass, and can be suitably used as a black ink that can withstand practical use even when carbon black is used in combination with charcoal or bamboo charcoal. Furthermore, the manufacturing method thereof has advantages in terms of manufacturing process such as at least kneading property and processability of pigment dispersion, and furthermore, it is possible to reduce the number of kneading steps and shorten the kneading time. EXAMPLES

[0105] The present invention will be described in more detail with reference to the following examples and comparative examples, but the present invention is not limited to the following examples. In addition, "parts" are based on mass unless otherwise specified.

[0106] The components used are as follows: Bamboo charcoal 1: Product name "Takesumi Powder", bamboo charcoal, average particle size 10μm, manufactured by Unicolor Bamboo charcoal 2: Product name "Takesumi Powder", bamboo charcoal, average particle size 200μm, manufactured by Unicolor MA-70: Product name "MA-70", carbon black that is neither charcoal nor bamboo charcoal (primary particle size 24 nm), manufactured by Mitsubishi Chemical Corporation S39000: Pigment dispersant, product name "Solsperse 39000", polyamine-based dispersant, base number 30mgKOH / g, manufactured by Lubrizol Japan Resin varnish 1: (see below) EMK: 4,4´-bis(diethylamino)benzophenone ·TPO: 2,4,6-trimethylbenzoyl-diphenylphosphine oxide TMP(EO)3TA: Triacrylate of 3 moles of ethylene oxide adduct of trimethylolpropane ·DPHA: Dipentaerythritol hexaacrylate CN111US: Product name "Sartomer CN111US", epoxylated soybean oil acrylate resin, functional group number 3, manufactured by Sartomer Corporation Calcium carbonate: Calcium carbonate, product name "Hakuenka DD", manufactured by Shiraishi Calcium Co., Ltd. Polymerization inhibitor 1: Trade name "Irganox1010", hindered phenol antioxidant, pentaerythritol tetrakis[3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate], manufactured by BASF Wax 1: Polyethylene wax

[0107] The average particle size of charcoal and bamboo charcoal can be measured by laser diffraction and scattering using the "Microtrac" series from Microtrac Bell Co., Ltd. In the case of commercially available products, the catalog data of the commercially available products is used as a priority.

[0108] (Preparation of Resin Varnish 1)

[0109] First, a resin was prepared in accordance with Example 1 described in Japanese Patent No. 6829978. Specifically, 800 parts by mass of coconut oil and 36 parts by mass of pentaerythritol were mixed in a reaction vessel equipped with a stirrer, a reflux condenser, and a thermometer, and the mixture was held at 250°C for 1 hour to carry out an ester exchange reaction. The mixture was cooled to 150°C, and 160 parts by mass of rosin, 50 parts by mass of isophthalic acid, and further xylene for reflux were added, gradually heated to 250°C, and held for 6 hours to carry out a condensation polymerization reaction while dehydrating. Furthermore, in order to remove the xylene from the solvent, the reaction was carried out under reduced pressure for 3 hours to distill off the solvent, thereby obtaining a resin. The acid value of the obtained resin was 13 mgKOH / g, the SP value by turbidity point titration method was 9.74, and the weight average molecular weight (Mw ) was 7,000. 80 parts by mass of this resin, 19 parts by mass of ditrimethololpropane tetraacrylate, and 1 part by mass of butylhydroxytoluene were charged into a reaction vessel equipped with a cooling tube, and heated and stirred at 100°C for 1 hour to prepare resin varnish 1. In resin varnish 1, ditrimethololpropane tetraacrylate corresponds to component (F).

[0110] <Examples 1 and 2, Comparative Examples 1 and 2, Reference Example 1>

[0111] The ingredients were mixed under the conditions shown in Table 1 and kneaded in a three-roll mill. The kneading process was repeated until the viscosity of the kneaded product reached 40 Pa·s (25°C), and the number of passes and grind value were evaluated. The lower the "number of passes" value, the better the kneading properties and the better the processability of the pigment dispersion.

[0112] The grind value was measured using a grind meter (manufactured by Japan Cedars Service Co., Ltd.) in accordance with JIS K5701-1:2000 (method of measuring degree of mixing), with the scraper being moved to move the scraper, and the scale position when three or more continuous lines of 10 mm or more appeared in one groove was measured as value A ("grind A value"), and the scale position when 10 or more appeared was measured as value B ("grind B value"). Note that the lower the "grind A value" and "grind B value", the better the particle size.

[0113] The components and evaluation results for Examples 1 and 2, Comparative Examples 1 and 2, and Reference Example 1 are shown in Table 1. The content of the component (F) in each ink composition was 29.2 mass% for Reference Example 1, 29.2 mass% for Example 1, and 24.2 mass% for Example 2. For example, in the case of Example 1, the content of the component (F) is 33.0 parts by mass × 19 parts by mass / 100 parts by mass + 10.9 parts by mass + 12 parts by mass ≒ 29.2 mass%.

[0114] The content of the non-curable resin in the solid content was 26.4 mass% for both the ink compositions of Examples 1 and 2. The mass ratio of the total amount of monomers to the total amount of oligomers in Example 1 was 5.8:1, and the mass ratio of the total amount of monomers to the total amount of oligomers in Example 2 was 2.4:1.

[0115] [Table 1]

[0116] From the above, it was at least confirmed that this example can provide an active energy ray-curable ink composition that can be suitably used for black inks and the like, using carbon black in combination with charcoal or bamboo charcoal.

Claims

1. (A) charcoal and / or bamboo charcoal having an average particle size of 5 to 100 μm; (B) carbon black; and (C) an epoxy (meth)acrylate resin containing a triglyceride skeleton; An active energy ray-curable ink composition comprising:

2. The component (A) is bamboo charcoal. The active energy ray-curable ink composition according to claim 1.

3. The average particle size of the component (A) is 5 to 50 μm. The active energy ray-curable ink composition according to claim 1 or 2.

4. The (C) epoxy (meth)acrylate resin containing a triglyceride skeleton is an epoxidized soybean oil (meth)acrylate resin. The active energy ray-curable ink composition according to claim 1 or 2.

5. Further, (D) a pigment dispersant is contained, The active energy ray-curable ink composition according to claim 1 or 2.

6. Further, the composition contains a photopolymerization initiator (E). The active energy ray-curable ink composition according to claim 1 or 2.

7. Further, the composition contains (F) a compound having an ethylenically unsaturated group, The active energy ray-curable ink composition according to claim 1 or 2.

8. The method includes a step of kneading (A) wood charcoal and / or bamboo charcoal having an average particle size of 5 to 100 μm, (B) carbon black, and (C) an epoxy (meth)acrylate resin containing a triglyceride skeleton, A method for producing an active energy ray-curable ink composition.

9. A step of printing an object using the active energy ray-curable ink composition according to claim 1 or 2; a step of irradiating the active energy ray-curable ink composition printed on the object with active energy rays to cure the composition; A printing method using an active energy ray-curable ink composition comprising the above-mentioned.

10. A printed matter obtained by the printing method according to claim 9.

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