Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D11/00—Inks
  • C09D11/30—Inkjet printing inks
  • C09D11/40—Ink-sets specially adapted for multi-colour inkjet printing
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D11/00—Inks
  • C09D11/02—Printing inks
  • C09D11/10—Printing inks based on artificial resins
  • C09D11/101—Inks specially adapted for printing processes involving curing by wave energy or particle radiation, e.g. with UV-curing following the printing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M3/00—Printing processes to produce particular kinds of printed work, e.g. patterns
  • B41M3/008—Sequential or multiple printing, e.g. on previously printed background; Mirror printing; Recto-verso printing; using a combination of different printing techniques; Printing of patterns visible in reflection and by transparency; by superposing printed artifacts
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M7/00—After-treatment of prints, e.g. heating, irradiating, setting of the ink, protection of the printed stock
  • B41M7/0081—After-treatment of prints, e.g. heating, irradiating, setting of the ink, protection of the printed stock using electromagnetic radiation or waves, e.g. ultraviolet radiation, electron beams
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D11/00—Inks
  • C09D11/02—Printing inks
  • C09D11/10—Printing inks based on artificial resins
  • C09D11/106—Printing inks based on artificial resins containing macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • C09D11/107—Printing inks based on artificial resins containing macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds from unsaturated acids or derivatives thereof
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D11/00—Inks
  • C09D11/30—Inkjet printing inks
  • C09D11/32—Inkjet printing inks characterised by colouring agents
  • C09D11/322—Pigment inks
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D11/00—Inks
  • C09D11/30—Inkjet printing inks
  • C09D11/38—Inkjet printing inks characterised by non-macromolecular additives other than solvents, pigments or dyes

Definitions

• This disclosure relates to an active energy ray curable inkjet ink, an active energy ray curable ink set, and an image recording method.
• JP 2018-035369 A describes a composition containing a radical polymerizable compound as component A, a radical polymerization initiator as component B, a color pigment as component C, and a pigment dispersant as component D, and the composition contains benzyl (meth)acrylate and/or 2-phenoxyethyl (meth)acrylate as component A-1, a monofunctional or bifunctional (meth)acrylate compound having an aliphatic hydrocarbon group having 6 or more carbon atoms as component A-2, and a compound represented by any one of the following formulas II and III as component A-3.
• the inkjet ink composition for printing on building materials is characterized in that it contains at least one type of component A-1, the total content of component A-1 is 10 to 50% by mass, the total content of component A-2 is 5 to 40% by mass, and the total content of component A-3 is 10 to 50% by mass, based on the total mass of the ink composition; and, as component C, it contains at least one inorganic pigment selected from the group consisting of Pigment Blue 28, Pigment Red 101, Pigment Yellow 42, and Pigment Yellow 184.
• image recordings obtained by applying ink onto a substrate are required to have excellent abrasion resistance and separability of the image from the substrate.
• the present disclosure has been made in consideration of these circumstances, and the problem that one embodiment of the present invention aims to solve is to provide an active energy beam-curable inkjet ink, an active energy beam-curable ink set, and an image recording method that are capable of obtaining an image recording that is excellent in abrasion resistance and separability of the image from the substrate.
• An active energy ray-curable inkjet ink comprising: a bifunctional (meth)acrylate having a linear or branched alkylene group having 4 to 10 carbon atoms; a silicone-based surfactant having a (meth)acryloyl group; a colorant; and an acrylic resin having a glass transition temperature of 30° C. or higher, wherein the content of the bifunctional (meth)acrylate is 20 mass % or more with respect to the total amount of the active energy ray-curable inkjet ink.
• ⁇ 2> The active energy ray-curable ink-jet ink according to ⁇ 1>, wherein a mass ratio of the content of the silicone surfactant having a (meth)acryloyl group to the content of the acrylic resin is 1 to 10.
• ⁇ 3> The active energy ray-curable ink-jet ink according to ⁇ 1> or ⁇ 2>, wherein a mass ratio of the content of the silicone-based surfactant having a (meth)acryloyl group to the content of the acrylic resin is 4 to 7.
• ⁇ 4> The active energy ray-curable ink-jet ink according to any one of ⁇ 1> to ⁇ 3>, wherein the content of the silicone surfactant having a (meth)acryloyl group is 0.5% by mass to 10% by mass, based on the total amount of the active energy ray-curable ink-jet ink.
• ⁇ 5> The active energy ray-curable ink-jet ink according to any one of ⁇ 1> to ⁇ 4>, wherein the content of the silicone surfactant having a (meth)acryloyl group is 4% by mass to 7% by mass, based on the total amount of the active energy ray-curable ink-jet ink.
• ⁇ 6> The active energy ray-curable ink-jet ink according to any one of ⁇ 1> to ⁇ 5>, wherein the silicone-based surfactant having a (meth)acryloyl group contains a polyether structure and a polysiloxane structure, and a mass ratio of the content of the polysiloxane structure to the content of the polyether structure is 0.5 or more.
• ⁇ 7> The actinic ray-curable ink-jet ink according to any one of ⁇ 1> to ⁇ 6>, further comprising a monofunctional (meth)acrylate having a hydroxyl group.
• ⁇ 8> The active energy ray-curable ink-jet ink according to any one of ⁇ 1> to ⁇ 7>, wherein the acrylic resin has a weight average molecular weight of 5,000 to 100,000.
• An active energy ray-curable ink set comprising: a first ink, which is the active energy ray-curable inkjet ink according to any one of ⁇ 1> to ⁇ 8>, and in which a colorant is a pigment other than a white pigment; and a second ink, which is the active energy ray-curable inkjet ink according to any one of ⁇ 1> to ⁇ 8>, and in which the colorant is a white pigment.
• ⁇ 10> The actinic ray-curable ink set according to ⁇ 9>, wherein, when the first ink and the second ink are the same in mass, the content of the acrylic resin in the first ink is greater than the content of the acrylic resin in the second ink.
• ⁇ 11> The actinic ray-curable ink set according to ⁇ 9> or ⁇ 10>, further comprising a third ink containing at least one acid group-containing compound selected from the group consisting of polymerizable monomers having an acid group and polymers having an acid group.
• ⁇ 12> The active energy ray-curable ink set according to ⁇ 11>, wherein, when the first ink, the second ink, and the third ink are of the same mass, the content of the acrylic resin in the first ink is greater than the content of the acrylic resin in the second ink, and the content of the acrylic resin in the first ink is greater than the content of the acrylic resin in the third ink.
• An image recording method comprising: a step of applying the active energy ray-curable inkjet ink according to any one of ⁇ 1> to ⁇ 8> onto a substrate by an inkjet recording method; and a step of irradiating the applied active energy ray-curable inkjet ink with active energy rays.
• An image recording method using the actinic energy ray-curable ink set according to any one of ⁇ 9> to ⁇ 12> including the steps of: applying a second ink onto a substrate by an inkjet recording method; irradiating the applied second ink with actinic energy rays; applying a first ink onto the substrate to which the second ink has been applied by an inkjet recording method; and irradiating the applied first ink with actinic energy rays.
• an active energy beam-curable inkjet ink an active energy beam-curable ink set, and an image recording method that can produce an image recording that is excellent in abrasion resistance and separation of the image from the substrate.
• active energy ray curable inkjet ink active energy ray curable ink set, and image recording method disclosed herein are described in detail below.
• a numerical range indicated using “to” means a range that includes the numerical values before and after “to” as the minimum and maximum values, respectively.
• the upper limit or lower limit described in a certain numerical range may be replaced with the upper limit or lower limit of another numerical range described in a certain numerical range.
• the upper limit or lower limit described in a certain numerical range may be replaced with a value shown in the examples.
• the amount of each component in a composition means the total amount of the multiple substances present in the composition when multiple substances corresponding to each component are present in the composition, unless otherwise specified.
• a combination of two or more preferred aspects is a more preferred aspect.
• the term "process” includes not only an independent process but also a process that cannot be clearly distinguished from other processes, as long as the intended purpose of the process is achieved.
• image refers to any film formed by applying ink
• image recording refers to the formation of an image (i.e., a film).
• image in this specification also includes a solid image.
• (meth)acrylate is a concept that encompasses both acrylate and methacrylate.
• (meth)acrylic is a concept that encompasses both acrylic and methacrylic.
• the active energy beam-curable inkjet ink (hereinafter, simply referred to as "ink") according to one embodiment of the present disclosure contains a bifunctional (meth)acrylate having a linear or branched alkylene group having 4 to 10 carbon atoms, a silicone-based surfactant having a (meth)acryloyl group, a colorant, and an acrylic resin having a glass transition temperature of 30°C or higher, and the content of the bifunctional (meth)acrylate is 20% by mass or more based on the total amount of the active energy beam-curable inkjet ink.
• the ink according to an embodiment of the present disclosure is applied onto a substrate, and then an active energy ray is irradiated to obtain an image recording material in which an ink film is formed on the substrate as an image.
• the ink according to an embodiment of the present disclosure contains a bifunctional (meth)acrylate having a linear or branched alkylene group having 4 to 10 carbon atoms and a silicone-based surfactant having a (meth)acryloyl group, and therefore a polymerization reaction proceeds upon irradiation with active energy rays.
• the ink contains a silicone-based surfactant having a (meth)acryloyl group, it is considered that the ink film formed by the polymerization reaction has a surface activity.
• the adhesion between the substrate and the ink film decreases, and the ink film peels off from the substrate.
• a treatment liquid e.g., an alkaline aqueous solution
• the ink film formed by the ink according to an embodiment of the present disclosure has a surface activity, it is easy to float after peeling off from the substrate, and has excellent separability. This allows the substrate from which the image has been separated to be recovered, for example, when the substrate is reused.
• the ink according to an embodiment of the present disclosure contains an acrylic resin having a glass transition temperature of 30° C. or higher, it is believed that the ink film has high surface hardness and excellent abrasion resistance.
• JP 2018-035369 A does not anticipate that the content of bifunctional (meth)acrylate having a linear or branched alkylene group with 4 to 10 carbon atoms will be 20% by mass or more relative to the total amount of the ink.
• the ink according to an embodiment of the present disclosure is an active energy ray curable ink. That is, the ink according to an embodiment of the present disclosure is cured by irradiation with active energy rays.
• active energy rays include gamma rays, beta rays, electron beams, ultraviolet rays, and visible light rays. Of these, the active energy rays are preferably ultraviolet rays.
• the ink according to an embodiment of the present disclosure is preferably an ultraviolet ray curable ink.
• An ink according to an embodiment of the present disclosure contains a difunctional (meth)acrylate having a linear or branched alkylene group having 4 to 10 carbon atoms (hereinafter also referred to as a “specific difunctional (meth)acrylate”).
• Bifunctional (meth)acrylate means a compound that has two (meth)acryloyloxy groups.
• the specific bifunctional (meth)acrylate has a linear or branched alkylene group with 4 to 10 carbon atoms, which results in images with excellent abrasion resistance.
• linear or branched alkylene groups examples include methylene, ethylene, i-propylene, n-butylene, t-butylene, and heptylene groups, and from the same viewpoint as above, the number of carbon atoms in the linear or branched alkylene group is preferably 6 to 8, and more preferably 6.
• the ink may contain only one type of specific bifunctional (meth)acrylate, or two or more types.
• bifunctional (meth)acrylates include, for example, 3-methyl-1,5-pentanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol diacrylate, 1,7-heptanediol diacrylate, 1,8-octanediol diacrylate, and 1,9-nonanediol di(meth)acrylate.
• the specific bifunctional (meth)acrylate is preferably at least one selected from the group consisting of 3-methyl-1,5-pentanediol di(meth)acrylate and 1,6-hexanediol diacrylate, and more preferably 3-methyl-1,5-pentanediol di(meth)acrylate.
• the content of the specific bifunctional (meth)acrylate is 20% by mass or more, preferably 20% by mass to 80% by mass, and more preferably 30% by mass to 50% by mass, based on the total amount of the ink, from the viewpoints of abrasion resistance and odor.
• the ink according to an embodiment of the present disclosure preferably contains a monofunctional (meth)acrylate having a hydroxyl group (hereinafter also referred to as a "specific monofunctional (meth)acrylate").
• Monofunctional (meth)acrylate means a compound that has one (meth)acryloyloxy group.
• the specific monofunctional (meth)acrylate has a hydroxyl group, which prevents water from accumulating locally in the ink film and improves water resistance.
• the presence of the specific monofunctional (meth)acrylate reduces the oxygen concentration in the ink, suppressing polymerization inhibition caused by oxygen and improving curing properties. As a result, the amount of unreacted polymerizable compounds can be reduced, and odors can be reduced.
• the ink may contain only one type of specific monofunctional (meth)acrylate, or two or more types.
• the number of hydroxyl groups contained in the specific monofunctional (meth)acrylate is not particularly limited and may be, for example, 1 to 6. From the viewpoint of the viscosity of the ink, the number of hydroxyl groups is preferably 1 to 3, and more preferably 1 or 2.
• the molecular weight of the specific monofunctional (meth)acrylate is 130 to 150.
• Specific monofunctional (meth)acrylates include, for example, 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate.
• the specific monofunctional (meth)acrylate is preferably 4-hydroxybutyl (meth)acrylate from the standpoints of water resistance and low odor.
• the content of the specific monofunctional (meth)acrylate is preferably 30% to 70% by mass, and more preferably 40% to 50% by mass, based on the total amount of the ink.
• the ink according to an embodiment of the present disclosure may contain a polymerizable compound other than the specific bifunctional (meth)acrylate and the specific monofunctional (meth)acrylate, as long as the effect of the present disclosure is not significantly impaired.
• the other polymerizable compounds are not particularly limited as long as they are compounds other than the specific bifunctional (meth)acrylates and specific monofunctional (meth)acrylates and have a polymerizable group.
• the polymerizable group in the other polymerizable compound is preferably a radical polymerizable group, more preferably an ethylenically unsaturated group, and even more preferably a (meth)acryloyloxy group.
• the other polymerizable compound is preferably a radical polymerizable compound, more preferably an ethylenically unsaturated compound, and even more preferably a (meth)acrylate compound.
• the other polymerizable compounds may be monofunctional polymerizable compounds having one polymerizable group, or polyfunctional polymerizable compounds having two or more polymerizable groups.
• monofunctional polymerizable compound examples include monofunctional (meth)acrylates, monofunctional (meth)acrylamides, monofunctional aromatic vinyl compounds, monofunctional vinyl ethers, and monofunctional N-vinyl compounds.
• Examples of monofunctional (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, tert-octyl (meth)acrylate, isoamyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, Stearyl (meth)acrylate, isostearyl (meth)acrylate, cyclohexyl (meth)acrylate, 4-n-butylcyclohexyl (meth)acrylate, 4-tert-butylcyclohexyl (meth)acrylate, bornyl (meth)acrylate, isobornyl (meth)acrylate, 2-ethylhexyl diglycol
• Examples of monofunctional (meth)acrylamides include (meth)acrylamide, N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-propyl(meth)acrylamide, N-n-butyl(meth)acrylamide, N-t-butyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, N-methylol(meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, and (meth)acryloylmorpholine.
• monofunctional aromatic vinyl compounds include styrene, dimethylstyrene, trimethylstyrene, isopropylstyrene, chloromethylstyrene, methoxystyrene, acetoxystyrene, chlorostyrene, dichlorostyrene, bromostyrene, vinyl benzoic acid methyl ester, 3-methylstyrene, 4-methylstyrene, 3-ethylstyrene, 4-ethylstyrene, 3-propylstyrene, 4-propylstyrene, 3-butylstyrene, 4-butylstyrene, 3-hexylstyrene, 4-hexylstyrene, 3-octylstyrene, 4-octylstyrene, 3-(2-ethylhexyl)styrene, 4-(2-ethylhexyl)sty
• Examples of monofunctional vinyl ethers include methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, n-butyl vinyl ether, t-butyl vinyl ether, 2-ethylhexyl vinyl ether, n-nonyl vinyl ether, lauryl vinyl ether, cyclohexyl vinyl ether, cyclohexylmethyl vinyl ether, 4-methylcyclohexylmethyl vinyl ether, benzyl vinyl ether, dicyclopentenyl vinyl ether, 2-dicyclopentenoxyethyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, butoxyethyl vinyl ether, methoxyethoxyethyl vinyl ether, ethoxyethoxyethyl vinyl ether, methoxypolyethylene glycol vinyl ether, tetrahydrofurfuryl vinyl ether, 2-hydroxyethyl vinyl ether, 2-hydroxypropyl
• Examples of monofunctional N-vinyl compounds include N-vinyl- ⁇ -caprolactam and N-vinylpyrrolidone.
• polyfunctional polymerizable compound examples include polyfunctional (meth)acrylate compounds and polyfunctional vinyl ethers.
• polyfunctional (meth)acrylates 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, tetraethylene glycol di(meth)acrylate, EO-modified neopentyl glycol di(meth)acrylate, PO-modified neopentyl glycol di(meth)acrylate, EO-modified hexanediol di(meth)acrylate, PO-modified hexanediol di(meth)acrylate, decanediol di(meth)acrylate, dodecanediol di(meth)
• acrylate pentaerythritol di(meth)acrylate, ethylene glycol diglycidyl ether di(meth)acrylate, diethylene glycol diglycidyl ether di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, trimethylolethane tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolpropane EO adduct tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tri(meth)acryloyloxyethoxytrimethylolpropane, glycerin polyglycidyl ether
• polyfunctional vinyl ethers examples include 1,4-butanediol divinyl ether, ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, polyethylene glycol divinyl ether, propylene glycol divinyl ether, butylene glycol divinyl ether, hexanediol divinyl ether, 1,4-cyclohexanedimethanol divinyl ether, bisphenol A alkylene oxide divinyl ether, bisphenol F alkylene oxide divinyl ether, trimethylolethane trivinyl ether, trimethylolpropane trivinyl ether, and ditrimethylolpropane trivinyl ether.
• vinyl ethers examples include tetravinyl ether, glycerin trivinyl ether, pentaerythritol tetravinyl ether, dipentaerythritol pentavinyl ether, dipentaerythritol hexavinyl ether, EO-added trimethylolpropane trivinyl ether, PO-added trimethylolpropane trivinyl ether, EO-added ditrimethylolpropane tetravinyl ether, PO-added ditrimethylolpropane tetravinyl ether, EO-added pentaerythritol tetravinyl ether, PO-added pentaerythritol tetravinyl ether, PO-added pentaerythritol tetravinyl ether, EO-added dipentaerythritol hexa
• the inks of one embodiment of the present disclosure contain at least one colorant.
• a colorant means a substance that, when contained in an ink, can make the ink a chromatic or achromatic ink.
• the colorant may be a chromatic (e.g., cyan, magenta, yellow, etc.) colorant or an achromatic (e.g., white and black) colorant.
• a chromatic e.g., cyan, magenta, yellow, etc.
• achromatic e.g., white and black
• Colorants include dyes and pigments. From the standpoint of durability such as heat resistance, light resistance, and water resistance, it is preferable that the colorant is a pigment.
• a pigment dispersion is a liquid obtained by dispersing a pigment in a liquid medium using a dispersant, and contains at least a pigment, a dispersant, and a liquid medium. Details of the dispersant will be described later.
• the liquid medium may be an organic solvent or a polymerizable compound.
• pigment either organic or inorganic pigments that are normally commercially available can be used.
• examples of pigments include those described in “Dictionary of Pigments” edited by Seijiro Ito (published in 2000), “Industrial Organic Pigments” by W. Herbst and K. Hunger, and in JP-A Nos. 2002-12607, 2002-188025, 2003-26978, and 2003-342503.
• the colorant content is preferably 0.5% to 15% by mass, more preferably 1% to 10% by mass, and even more preferably 2% to 5% by mass, based on the total amount of ink.
• the pigment When a pigment is used as the colorant, the pigment can be contained in the ink as a pigment dispersion.
• the pigment can be dispersed in a liquid medium using a dispersant.
• a dispersant a commonly known dispersant can be used. From the viewpoint of dispersion stability, the dispersant is preferably a compound having both a hydrophilic structure and a hydrophobic structure.
• Dispersants include, for example, low molecular weight dispersants with a molecular weight of less than 1000, such as higher fatty acid salts, alkyl sulfates, alkyl ester sulfates, alkyl sulfonates, sulfosuccinates, naphthalene sulfonates, alkyl phosphates, polyoxyalkylene alkyl ether phosphates, polyoxyalkylene alkyl phenyl ethers, polyoxyethylene polyoxypropylene glycols, glycerin fatty acid esters, sorbitan fatty acid esters, polyoxyethylene fatty acid amides, and amine oxides.
• low molecular weight dispersants with a molecular weight of less than 1000, such as higher fatty acid salts, alkyl sulfates, alkyl ester sulfates, alkyl sulfonates, sulfosuccinates, naphthalen
• the dispersant may be a high molecular weight dispersant having a molecular weight of 1000 or more obtained by copolymerizing a hydrophilic monomer and a hydrophobic monomer.
• the hydrophilic monomer is preferably a dissociable group-containing monomer, and is preferably a dissociable group-containing monomer having a dissociable group and an ethylenically unsaturated bond.
• the dissociable group-containing monomer include a carboxy group-containing monomer, a sulfonic acid group-containing monomer, and a phosphoric acid group-containing monomer.
• the hydrophobic monomer is preferably an aromatic group-containing monomer having an aromatic group and an ethylenically unsaturated bond, or an aliphatic hydrocarbon group-containing monomer having an aliphatic hydrocarbon group and an ethylenically unsaturated bond.
• the polymer may be either a random copolymer or a block copolymer.
• the dispersant may be a commercially available product.
• commercially available products include DISPERBYK-101, DISPERBYK-102, DISPERBYK-103, DISPERBYK-106, DISPERBYK-110, DISPERBYK-111, DISPERBYK-161, DISPERBYK-162, DISPERBYK -163, DISPERBYK-164, DISPERBYK-166, DISPERBYK-167, DISPERBYK-168, DISPERBYK-170, DISPERBYK-171, DISPERBYK-174, DISPERBYK-182 (the above, BY manufactured by K-chemy); and and SOLSPERSE 3000, SOLSPERSE 5000, SOLSPERSE 9000, SOLSPERSE 12000, SOLSPERSE 13240, SOLSPERSE 13940, SOLSPERSE 17000, SOLSPERSE 22000, SOLSPERSE 24000, SOLSPERSE 26000
• Any known dispersing device can be used to disperse the pigment, such as a ball mill, sand mill, bead mill, roll mill, jet mill, paint shaker, attritor, ultrasonic disperser, or disperser.
• the content of dispersant relative to the content of pigment in the ink is preferably 0.05 to 1.0 by mass, and more preferably 0.1 to 0.5.
• the ink according to one embodiment of the present disclosure contains at least one silicone surfactant having a (meth)acryloyl group.
• the ink film that is formed has surface activity.
• a treatment liquid e.g., an alkaline aqueous solution
• the adhesion between the substrate and the ink film decreases, and the ink film peels off from the substrate.
• the ink film has surface activity, it tends to float after peeling off from the substrate, and has excellent separability.
• the number of (meth)acryloyl groups contained in the silicone surfactant having a (meth)acryloyl group may be only one, or may be two or more. From the viewpoint of separability, the number of (meth)acryloyl groups is preferably 2 or more, and more preferably 3 or more. The upper limit of the number of (meth)acryloyl groups is not particularly limited, but is, for example, 5 from the viewpoint of ejection properties.
• the silicone surfactant having a (meth)acryloyl group is preferably a polyether-modified polydimethylsiloxane having a (meth)acryloyl group.
• the position of the polyether chain is not particularly limited, and may be at one end of the main chain, at both ends of the main chain, or as a side chain.
• the polyether chain is preferably a polyoxyalkylene chain.
• silicone surfactants having (meth)acryloyl groups include, for example, BYK-UV3500, 3505, 3530, 3570, 3575, and 3576 (manufactured by BYK Corporation), Tegorad 2100, 2200, 2250, 2300, 2500, 2600, 2700, 2800, 2010, and 2011 (manufactured by Evonik Corporation), EBECRYL 350 and 1360 (manufactured by Daicel-Allnex Corporation), and KP-410, 411, 412, 413, 414, 415, 416, 418, 420, 422, and 423 (manufactured by Shin-Etsu Silicones Co., Ltd.).
• the silicone surfactant having a (meth)acryloyl group contains a polyether structure and a polysiloxane structure, and the mass ratio of the content of the polysiloxane structure to the content of the polyether structure is preferably 0.5 or more, and more preferably 0.6 or more.
• the upper limit of the above mass ratio is, for example, 0.95.
• the mass ratio of the content of the polysiloxane structure to the content of the polyether structure is calculated by nuclear magnetic resonance ( 1H -NMR) spectroscopy.
• the content of the silicone surfactant having a (meth)acryloyl group is preferably 0.5% by mass to 10% by mass, and more preferably 4% by mass to 7% by mass, based on the total amount of the ink.
• the ink according to one embodiment of the present disclosure contains at least one acrylic resin having a glass transition temperature of 30° C. or higher (hereinafter, also referred to as a “specific acrylic resin”).
• acrylic resin refers to a resin that contains at least one of structural units derived from (meth)acrylic acid and structural units derived from (meth)acrylic acid esters.
• the glass transition temperature of the specific acrylic resin is preferably 35°C or higher, and more preferably 65°C or higher.
• the glass transition temperature is preferably 140°C or lower, and more preferably 100°C or lower.
• the glass transition temperature of a specific acrylic resin refers to a value measured using differential scanning calorimetry (DSC).
• DSC differential scanning calorimetry
• EXSTAR6220 manufactured by SII NanoTechnology, Inc.
• DSC differential scanning calorimeter
• the glass transition temperature (Tg) means the weighted average of the glass transition temperatures of each acrylic resin.
• the weight average molecular weight of the specific acrylic resin is preferably 5,000 to 100,0000, and more preferably 10,000 to 50,000.
• the weight average molecular weight is measured using gel permeation chromatography (GPC).
• GPC gel permeation chromatography
• an HLC-8220GPC manufactured by Tosoh Corporation
• three TSKgel SuperAWM-H columns manufactured by Tosoh Corporation, 6.0 mm I.D. x 15 cm
• N-methylpyrrolidone with 10 mM LiBr added
• the conditions are a sample concentration of 0.1% by mass, a flow rate of 0.5 mL/min, a sample injection amount of 60 ⁇ l, a measurement temperature of 40° C., and detection is performed using a refractive index (RI) detector.
• RI refractive index
• the calibration curve was prepared using eight samples of "TSK Standard Polystyrene” manufactured by Tosoh Corporation under the product names: "F-40", “F-20”, “F-4", “F-1”, "A-5000”, “A-2500”, "A-1000” and "n-propylbenzene” as standard samples.
• the specific acrylic resin preferably contains structural units derived from at least one selected from the group consisting of linear or branched aliphatic hydrocarbon group-containing (meth)acrylates and alicyclic hydrocarbon group-containing (meth)acrylates, and more preferably contains structural units derived from linear or branched aliphatic hydrocarbon group-containing (meth)acrylates and structural units derived from alicyclic hydrocarbon group-containing (meth)acrylates.
• linear or branched aliphatic hydrocarbon group-containing (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, t-butyl (meth)acrylate, n-amyl (meth)acrylate, i-amyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, i-octyl (meth)acrylate, decyl (meth)acrylate, i-decyl (meth)acrylate, lauryl (meth)acrylate, i-dodecyl (meth)acrylate, stearyl (meth)acrylate, i-stearyl (meth)acrylate
• Examples of alicyclic hydrocarbon group-containing (meth)acrylates include cyclopropyl (meth)acrylate, cyclobutyl (meth)acrylate, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, cycloheptyl (meth)acrylate, cyclooctyl (meth)acrylate, cyclononyl (meth)acrylate, cyclodecyl (meth)acrylate, isobornyl (meth)acrylate, norbornyl (meth)acrylate, and adamantyl (meth)acrylate.
• the mass ratio of the content of the silicone surfactant having a (meth)acryloyl group to the content of the specific acrylic resin is preferably 1 to 10, and more preferably 4 to 7. If the mass ratio is 1 or more, the ejection properties are improved. Furthermore, if the mass ratio is 10 or less, the abrasion resistance is improved.
• the content of the specific acrylic resin is preferably 0.2% to 3% by mass, and more preferably 0.5% to 1.5% by mass, based on the total amount of the ink.
• the ink according to an embodiment of the present disclosure may contain at least one polymerization initiator.
• the polymerization initiator is preferably a radical polymerization initiator that generates radicals.
• Radical polymerization initiators include alkylphenone compounds, acylphosphine compounds, aromatic onium salt compounds, organic peroxides, thio compounds, hexaarylbiimidazole compounds, ketoxime ester compounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds, compounds having a carbon-halogen bond, and alkylamine compounds.
• the polymerization initiator is preferably at least one selected from the group consisting of acylphosphine compounds and thio compounds, more preferably at least one selected from the group consisting of acylphosphine oxide compounds and thioxanthone compounds, and even more preferably a combination of an acylphosphine oxide compound and a thioxanthone compound.
• Acylphosphine oxide compounds include monoacylphosphine oxide compounds and bisacylphosphine oxide compounds.
• monoacylphosphine oxide compounds include isobutyryldiphenylphosphine oxide, 2-ethylhexanoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, (2,4,6-trimethylbenzoyl)ethoxyphenylphosphine oxide, o-toluyldiphenylphosphine oxide, p-t-butylbenzoyldiphenylphosphine oxide, 3-pyridylcarbonyldiphenylphosphine oxide, acryloyldiphenylphosphine oxide, benzoyldiphenylphosphine oxide, pivaloylphenylphosphinic acid vinyl ester, Examples include adipoylbisdiphenylphosphine oxide, pivaloyldiphenylphosphine oxide, p-toluyldiphenylphosphine oxide, 4-(t-butyl
• bisacylphosphine oxide compounds include bis(2,6-dichlorobenzoyl)phenylphosphine oxide, bis(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, bis(2,6-dichlorobenzoyl)-4-ethoxyphenylphosphine oxide, bis(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, bis(2,6-dichlorobenzoyl)-2-naphthylphosphine oxide, and bis(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide.
• Thioxanthone compounds include thioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-dichlorothioxanthone, 2-dodecylthioxanthone, 2,4-diethylthioxanthone, 2,4-dimethylthioxanthone, 1-methoxycarbonylthioxanthone, 2-ethoxycarbonylthioxanthone, 3-(2-methoxyethoxycarbonyl)thioxanthone, 4-butoxythioxanthone, 4-methyl ...
• the thioxanthone compound may be a commercially available product.
• commercially available products include the SPEEDCURE series manufactured by Lambson (e.g., SPEEDCURE 7010, SPEEDCURE CPTX, SPEEDCURE ITX, etc.).
• the ink according to one embodiment of the present disclosure preferably contains at least one polymerization initiator selected from the group consisting of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide and (2,4,6-trimethylbenzoyl)ethoxyphenylphosphine oxide, and more preferably contains phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide and (2,4,6-trimethylbenzoyl)ethoxyphenylphosphine oxide.
• the total content of at least one selected from the group consisting of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide and (2,4,6-trimethylbenzoyl)ethoxyphenylphosphine oxide (preferably, the total content of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide and (2,4,6-trimethylbenzoyl)ethoxyphenylphosphine oxide is preferably 3.5% by mass or more, and more preferably 5% by mass or more, based on the total amount of ink.
• the upper limit of the above total content is not particularly limited, but is, for example, 10% by mass.
• the ink according to one embodiment of the present disclosure contains a compound having two or more thioxanthone skeletons in the molecule as a polymerization initiator.
• the content of the compound having two or more thioxanthone structures in the molecule is preferably 1% by mass to 10% by mass, and more preferably 2% by mass to 8% by mass, based on the total amount of the ink.
• the ink according to one embodiment of the present disclosure preferably contains at least one polymerization inhibitor.
• polymerization inhibitors examples include hydroquinone compounds, phenothiazines, catechols, alkylphenols, alkylbisphenols, zinc dimethyldithiocarbamate, copper dimethyldithiocarbamate, copper dibutyldithiocarbamate, copper salicylate, thiodipropionic acid esters, mercaptobenzimidazole, phosphites, nitrosamine compounds, hindered amine compounds, and nitroxyl radicals.
• the polymerization inhibitor is a nitrosamine compound.
• nitrosamine compounds include N-nitroso-N-phenylhydroxylamine aluminum salt and N-nitroso-N-phenylhydroxylamine. Of these, it is preferable that the nitrosamine compound is N-nitroso-N-phenylhydroxylamine aluminum salt.
• the content of the polymerization inhibitor is preferably 0.05% to 1% by mass based on the total amount of the ink, from the viewpoint of improving the stability of the ink over time.
• the ink according to an embodiment of the present disclosure may contain additives such as a co-sensitizer, an ultraviolet absorber, an antioxidant, a discoloration inhibitor, a conductive salt, a solvent, and a basic compound, as necessary.
• additives such as a co-sensitizer, an ultraviolet absorber, an antioxidant, a discoloration inhibitor, a conductive salt, a solvent, and a basic compound, as necessary.
• the viscosity of the ink is preferably 0.5 mPa ⁇ s to 50 mPa ⁇ s, more preferably 5 mPa ⁇ s to 40 mPa ⁇ s, more preferably 7 mPa ⁇ s to 35 mPa ⁇ s, and even more preferably 8 mPa ⁇ s to 30 mPa ⁇ s.
• the viscosity is measured at 25° C. using a viscometer, for example, a TV-22 type viscometer manufactured by Toki Sangyo Co., Ltd.
• the surface tension of the ink is preferably 60 mN/m or less, more preferably 20 mN/m to 50 mN/m, and even more preferably 25 mN/m to 45 mN/m.
• the surface tension is measured at 25°C using a surface tensiometer, for example, an automatic surface tensiometer (product name "CBVP-Z”) manufactured by Kyowa Interface Science Co., Ltd., using the plate method.
• An ink set according to one embodiment of the present disclosure includes a first ink and a second ink.
• the first ink is one aspect of the ink according to an embodiment of the present disclosure, and the colorant is a pigment other than a white pigment.
• the second ink is one aspect of the ink according to an embodiment of the present disclosure, and the colorant is a white pigment.
• first ink and the second ink are the same as the preferred aspects of the ink that is one embodiment of the present disclosure, except for the following:
• pigments other than white pigments include cyan pigments, magenta pigments, yellow pigments, and black pigments.
• White pigments include, for example, titanium dioxide, barium sulfate, calcium carbonate, silica, zinc oxide, zinc sulfide, mica, talc, and pearls.
• the average primary particle diameter of the white pigment is preferably 150 nm or more, and more preferably 200 nm or more. From the viewpoint of ink ejection, the average primary particle diameter of the white pigment is preferably 400 nm or less, and more preferably 350 nm or less. The average primary particle diameter of the white pigment is preferably 150 nm to 400 nm.
• the average primary particle diameter of the white pigment is a value measured using a transmission electron microscope (TEM). Specifically, 50 randomly selected white pigment particles present within the field of view observed with the TEM are measured and averaged to obtain the primary particle diameters of the 50 particles.
• TEM transmission electron microscope
• a 1200EX transmission electron microscope manufactured by JEOL Ltd. can be used as the transmission electron microscope.
• the content of the specific acrylic resin in the first ink is greater than the content of the specific acrylic resin in the second ink.
• the mass ratio of the content of the specific acrylic resin in the first ink to the content of the specific acrylic resin in the second ink is preferably 2 or more, and more preferably 5 or more.
• the upper limit of the mass ratio is, for example, 15.
• the content of the specific acrylic resin in the first ink is preferably 0.2% by mass to 3% by mass, and more preferably 0.5% by mass to 1.5% by mass, relative to the total amount of the first ink.
• the content of the specific acrylic resin in the second ink is preferably 0.1% by mass to 1% by mass, and more preferably 0.3% by mass to 1% by mass, relative to the total amount of the second ink.
• the ink set preferably further comprises, in addition to the first ink and the second ink, a third ink that contains at least one acid group-containing compound selected from the group consisting of polymerizable monomers having an acid group and polymers having an acid group.
• the acid group reacts with an alkali to form a salt, which improves water solubility.
• the third ink is preferably applied directly onto the substrate, and if the third ink contains an acid group-containing compound, the alkali strippability is improved.
• Examples of the acid group in the acid group-containing compound include a carboxy group, a sulfo group, a phosphonic acid group, a phosphoric acid group, and a sulfonamide group.
• a "monomer” refers to a compound having a molecular weight of less than 1000.
• a “polymerizable monomer” refers to a compound having a molecular weight of less than 1000 and having a polymerizable group. The molecular weight of a monomer can be calculated based on the type and number of atoms constituting the monomer.
• polymerizable monomers having a carboxy group examples include 2-(meth)acryloyloxyethyl succinate, 2-(meth)acryloyloxyethyl phthalate, 2-(meth)acryloyloxyethyl hexahydrophthalate, 2-(meth)acryloyloxypropyl phthalate, 2-(meth)acryloyloxypropyl hexahydrophthalate, 2-carboxyethyl (meth)acrylate, and (meth)acrylic acid.
• polymerizable monomers having a sulfo group examples include 2-hydroxy-3-sulfopropyl (meth)acrylate, 2-(meth)acrylamido-2-methylpropanesulfonic acid, 2-sulfoethyl (meth)acrylate, 3-sulfopropyl (meth)acrylate, and 4-styrenesulfonic acid.
• polymerizable monomers having a phosphate group examples include 2-phosphonooxyethyl (meth)acrylate and 2-(meth)acryloyloxyethyl acid phosphate.
• the polymerizable monomer having an acid group is a polymerizable monomer having a carboxyl group from the viewpoints of improving alkaline strippability, safety, and low viscosity.
• the polymerizable monomer having an acid group may be a monofunctional polymerizable monomer having an acid group or a polyfunctional polymerizable monomer having an acid group, but from the viewpoints of improving alkaline peelability, safety, and low viscosity, it is preferably a monofunctional polymerizable monomer having an acid group, more preferably a monofunctional polymerizable monomer having a carboxy group, and even more preferably a monofunctional (meth)acrylate having a carboxy group.
• polymer means a compound having a weight average molecular weight of 1000 or more.
• polymers having acid groups examples include (meth)acrylic copolymers, polyurethanes, polyvinyl alcohol, polyvinyl butyral, polyvinyl formal, polyamides, polyesters, and epoxy resins.
• the polymer having acid groups is preferably a (meth)acrylic copolymer, polyurethane, or polyvinyl butyral.
• (meth)acrylic copolymer refers to a copolymer containing (meth)acrylic acid, (meth)acrylic acid esters (e.g., (meth)acrylic acid alkyl esters, (meth)acrylic acid aryl esters, (meth)acrylic acid allyl esters, etc.), (meth)acrylamide, (meth)acrylamide derivatives, and other (meth)acrylic acid derivatives as structural units.
• Polyurethane refers to a polymer obtained by a condensation reaction between a polyfunctional isocyanate compound having two or more isocyanate groups and a polyhydric alcohol having two or more hydroxyl groups.
• Polyvinyl butyral refers to a polymer obtained by reacting polyvinyl alcohol, obtained by partial or complete saponification of polyvinyl acetate, with butyraldehyde under acidic conditions. Polyvinyl butyral also includes polymers in which functional groups have been introduced into the molecule.
• the (meth)acrylic copolymer preferably contains a structural unit having an acid group.
• the acid group is preferably a carboxy group.
• structural units having a carboxy group include structural units derived from (meth)acrylic acid and structural units derived from a structural unit represented by the following formula 1.
• R1 represents a hydrogen atom or a methyl group
• R2 represents a single bond or an (n+1)-valent linking group
• A represents an oxygen atom or -NR3-
• R3 represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms
• n represents an integer of 1 to 5.
• the polymer having an acid group contains a structural unit derived from (meth)acrylic acid and a structural unit derived from an alkyl (meth)acrylate ester.
• the number of carbon atoms in the alkyl group contained in the alkyl (meth)acrylate ester is preferably 1 to 10, and more preferably 1 to 6.
• the weight average molecular weight of the polymer having an acid group is preferably 1,000 to 1,000,000, more preferably 5,000 to 500,000, and even more preferably 10,000 to 200,000.
• the total content of the acid group-containing compounds is preferably 8% by mass or more, more preferably 10% by mass or more, and even more preferably 14% by mass or more, based on the total amount of the third ink.
• the upper limit of the total content is, for example, 20% by mass.
• the third ink preferably contains a specific bifunctional (meth)acrylate.
• a preferred aspect of the specific bifunctional (meth)acrylate contained in the third ink is the same as the preferred aspect of the specific bifunctional (meth)acrylate contained in the ink according to an embodiment of the present disclosure.
• the third ink preferably contains a specific monofunctional (meth)acrylate.
• a preferred aspect of the specific monofunctional (meth)acrylate contained in the third ink is the same as a preferred aspect of the specific monofunctional (meth)acrylate that may be contained in the ink according to an embodiment of the present disclosure.
• the third ink may contain other polymerizable compounds.
• polymerizable compounds contained in the third ink include those similar to the other polymerizable compounds contained in the ink that is one embodiment of the present disclosure.
• the third ink preferably contains a specific acrylic resin.
• a preferred aspect of the specific acrylic resin contained in the third ink is the same as the preferred aspect of the specific acrylic resin contained in the ink according to an embodiment of the present disclosure.
• the content (Mc) of the specific acrylic resin in the first ink is greater than the content (Mw) of the specific acrylic resin in the second ink
• the content (Mc) of the specific acrylic resin in the first ink is greater than the content (Mp) of the specific acrylic resin in the third ink.
• the content of the specific acrylic resin in the second ink is greater than the content of the specific acrylic resin in the third ink.
• 1 ⁇ Mc/Mw ⁇ 4 is preferable, and 1.5 ⁇ Mc/Mw ⁇ 3 is more preferable.
• 1 ⁇ Mc/Mp ⁇ 10 is preferable, and 2 ⁇ Mc/Mp ⁇ 8 is more preferable.
• the ink film formed by the first ink will be located on the outermost side. If the content of the acrylic resin in the first ink is greater than the content of the specific acrylic resin in the second ink and the third ink, water resistance will be improved.
• the third ink may contain at least one polymerization initiator.
• the polymerization initiator contained in the third ink may be the same as the polymerization initiator contained in the ink that is one embodiment of the present disclosure.
• the third ink preferably contains at least one polymerization inhibitor.
• the polymerization inhibitor contained in the third ink may be the same as the polymerization inhibitor contained in the ink according to one embodiment of the present disclosure.
• the content of the polymerization inhibitor is preferably 0.05% to 0.5% by mass relative to the total amount of the third ink, from the viewpoint of improving the stability over time of the third ink.
• the third ink preferably contains at least one surfactant.
• the surfactant contained in the third ink may be the same as the silicone-based surfactant having a (meth)acryloyl group contained in the ink according to one embodiment of the present disclosure.
• the third ink may contain additives such as a co-sensitizer, an ultraviolet absorbing agent, an antioxidant, a discoloration inhibitor, a conductive salt, a solvent, and a basic compound, as necessary.
• additives such as a co-sensitizer, an ultraviolet absorbing agent, an antioxidant, a discoloration inhibitor, a conductive salt, a solvent, and a basic compound, as necessary.
• the third ink preferably does not contain a colorant.
• the third ink preferably acts as a primer to peel off the image recorded by the first ink and the second ink with an alkali.
• the viscosity of the third ink is preferably from 0.5 mPa ⁇ s to 50 mPa ⁇ s, more preferably from 5 mPa ⁇ s to 40 mPa ⁇ s, even more preferably from 7 mPa ⁇ s to 35 mPa ⁇ s, and particularly preferably from 8 mPa ⁇ s to 30 mPa ⁇ s.
• the surface tension of the third ink is preferably 60 mN/m or less, more preferably 20 mN/m to 40 mN/m, and even more preferably 23 mN/m to 30 mN/m.
• An image recording method A which is an embodiment of the present disclosure includes a step of applying the ink (the ink which is an embodiment of the present disclosure) onto a substrate by using an inkjet recording method, and a step of irradiating the applied ink with active energy rays.
• the type of the substrate is not particularly limited, and a substrate generally known in the art can be used as the substrate.
• the substrate include glass, quartz, and plastic film.
• the resin constituting the plastic film include cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, acrylic resin, chlorinated polyolefin resin, polyethersulfone resin, polyethylene terephthalate (PET), polyethylene naphthalate, nylon, polyethylene, polystyrene, polypropylene, polycycloolefin resin, polyimide resin, polycarbonate resin, and polyvinyl acetal.
• the plastic film may be a film containing only one of these resins, or a film containing two or more of them mixed together.
• the thickness of the substrate is not particularly limited, and is, for example, 1 ⁇ m to 10 mm.
• the thickness is preferably 1 ⁇ m to 500 ⁇ m, more preferably 2 ⁇ m to 200 ⁇ m, even more preferably 5 ⁇ m to 100 ⁇ m, and particularly preferably 10 ⁇ m to 90 ⁇ m.
• the thickness is preferably 0.1 mm to 10 mm, more preferably 0.15 mm to 8 mm, and even more preferably 0.2 mm to 5 mm.
• the substrate may be a beverage container.
• the material of the beverage container is not particularly limited, and examples include glass and plastic.
• the beverage container is preferably a plastic container, and is preferably a PET bottle containing polyethylene terephthalate as the main component.
• the substrate may also be a plastic film that is attached to the surface of the beverage container.
• the substrate may be subjected to a hydrophilization treatment.
• hydrophilization treatments include, but are not limited to, corona treatment, plasma treatment, heat treatment, abrasion treatment, light irradiation treatment (e.g., UV treatment), and flame treatment.
• Corona treatment can be performed, for example, using a Corona Master (product name "PS-10S", manufactured by Shinko Electric Meter Co., Ltd.).
• the conditions for the corona treatment may be appropriately selected depending on the type of substrate, etc.
• the inkjet recording method is not particularly limited as long as it is a method capable of recording an image, and any known method can be used.
• Examples of inkjet recording methods include a charge control method that uses electrostatic attraction to eject ink, a drop-on-demand method (pressure pulse method) that uses the vibration pressure of a piezoelectric element, an acoustic inkjet method that converts an electric signal into an acoustic beam and irradiates the ink to eject ink using radiation pressure, and a thermal inkjet (Bubble Jet (registered trademark)) method that heats the ink to form bubbles and uses the resulting pressure.
• a charge control method that uses electrostatic attraction to eject ink
• a drop-on-demand method pressure pulse method
• an acoustic inkjet method that converts an electric signal into an acoustic beam and irradiates the ink to eject ink using radiation pressure
• the inkjet heads used in inkjet recording methods include the shuttle method, which uses a short serial head and records by scanning the head in the width direction of the substrate, and the line method, which uses a line head in which recording elements are arranged to correspond to the entire area of one side of the substrate.
• patterns can be formed over the entire surface of the substrate by scanning the substrate in a direction intersecting the arrangement direction of the recording elements, eliminating the need for a transport system such as a carriage that scans a short head.
• the line method does not require complex scanning control of the carriage movement and the substrate, and only the substrate moves, making it possible to achieve faster recording speeds than the shuttle method.
• the amount of ink droplets ejected from the inkjet head is preferably 1 pL (picoliter) to 100 pL, more preferably 3 pL to 80 pL, and even more preferably 3 pL to 50 pL.
• Step of irradiating the applied ink with active energy rays examples include gamma rays, beta rays, electron beams, ultraviolet rays, and visible light rays.
• the active energy rays are preferably ultraviolet rays.
• the peak wavelength of the ultraviolet light is, for example, preferably 200 nm to 405 nm, more preferably 250 nm to 400 nm, and even more preferably 300 nm to 400 nm.
• Light sources for ultraviolet irradiation mainly include mercury lamps, gas lasers, solid-state lasers, and other types of lasers, with discharge lamps such as mercury lamps, metal halide lamps, and ultraviolet fluorescent lamps being widely known.
• Semiconductor light sources such as UV-LEDs (ultraviolet light-emitting diodes) and UV-LDs (ultraviolet laser diodes) are small, have a long life, are highly efficient, and are low-cost, and are expected to be useful as light sources for ultraviolet irradiation.
• the light source for ultraviolet irradiation is a metal halide lamp, high-pressure mercury lamp, medium-pressure mercury lamp, low-pressure mercury lamp, or UV-LED.
• polymerizing only a portion of the polymerizable monomer in the ink is also referred to as “temporary curing”, and irradiation with active energy rays for temporary curing is also referred to as “pinning exposure”.
• polymerizing substantially all of the polymerizable compound in the ink is also referred to as “main curing”, and irradiation with active energy rays for main curing is also referred to as "main exposure”.
• the step of irradiating the active energy rays it is preferable to provisionally cure the ink and then fully cure it. Specifically, it is preferable to apply the ink, then subject the ink to pinning exposure, and finally perform full exposure.
• the ink reaction rate after pinning exposure is preferably 10% to 80%.
• reaction rate of the ink refers to the polymerization rate of the polymerizable compound contained in the ink, which is determined by high performance liquid chromatography.
• the ink reaction rate is preferably 15% or more to further improve the graininess of the final image.
• the ink reaction rate is preferably 75% or less, more preferably 50% or less, more preferably 40% or less, more preferably 30% or less, and even more preferably 25% or less.
• the reaction rate of the ink after the main exposure is preferably more than 80% and not more than 100%, more preferably 85% to 100%, and even more preferably 90% to 100%. When the reaction rate is more than 80%, the adhesion is further improved.
• the reaction rate of the ink is determined by the following method.
• a substrate is prepared that has been subjected to the operations up to the end of irradiation of the ink with active energy rays.
• a sample piece (hereinafter referred to as the post-irradiation sample piece) having a size of 20 mm x 50 mm is cut out from the region of the substrate where the ink film exists.
• the cut-out post-irradiation sample piece is immersed in 10 mL of THF (tetrahydrofuran) for 24 hours to obtain an eluate in which the ink has been eluted.
• THF tetrahydrofuran
• the exposure dose of active energy rays for pinning exposure is preferably 10 mJ/cm 2 to 100 mJ/cm 2 , and more preferably 20 mJ/cm 2 to 60 mJ/cm 2 , from the viewpoint of more easily achieving the above-mentioned ink reaction rate.
• the exposure dose of the active energy rays for the main exposure is preferably from 50 mJ/cm 2 to 1000 mJ/cm 2 , and more preferably from 200 mJ/cm 2 to 800 mJ/cm 2 , from the viewpoint of completely curing the ink.
• the active energy rays in an atmosphere with an oxygen concentration of less than 1% by volume. It is more preferable that the oxygen concentration is 0.5% by volume or less, and even more preferable that the oxygen concentration is 0.3% by volume or less.
• the step of irradiating active energy rays from the viewpoint of image quality, it is preferable to irradiate the active energy rays within 0.1 to 5 seconds from the time the ink lands.
• Image recording method B which is an embodiment of the present disclosure, uses the above-mentioned ink set (the ink set, which is an embodiment of the present disclosure), and includes the steps of applying a second ink onto a substrate by an inkjet recording method, irradiating the applied second ink with active energy rays, applying a first ink onto the substrate to which the second ink has been applied, by an inkjet recording method, and irradiating the applied first ink with active energy rays.
• the type of substrate, the method of applying the ink using the inkjet recording method, and the method of irradiating with active energy rays are the same as those in the image recording method A described above.
• image recording method B it is preferable to apply the second ink, then perform pinning exposure on the second ink, apply the first ink on the provisionally cured second ink, apply the first ink, then perform pinning exposure on the first ink, and finally perform main exposure.
• the quality of the final image obtained is improved.
• the method may further include a step of applying the third ink onto the substrate by an inkjet recording method, and a step of irradiating the applied third ink with active energy rays.
• the second ink is applied onto the substrate to which the third ink has been applied.
• the third ink is subjected to pinning exposure
• the second ink is subjected to pinning exposure
• the first ink is applied onto the provisionally cured second ink
• the main exposure is performed.
• Cyan pigment (30 parts by weight), SOLSPERSE 32000 (9 parts by weight) as a dispersant, 3MPDDA (60 parts by weight) as a dispersion medium, and UV22 (1 part by weight) as a polymerization inhibitor were added to a Motor Mill M50 dispersing machine (manufactured by Eiger), and dispersion processing was carried out for 4 hours at a peripheral speed of 9 m/s using zirconia beads with a diameter of 0.65 mm, to obtain a cyan pigment dispersion.
• a white pigment dispersion was first prepared.
• White pigment 60 parts by weight
• SOLSPERSE 32000 9 parts by weight
• 3MPDDA 30 parts by weight
• UV22 1 part by weight
• a white pigment dispersion 60 parts by weight
• 3MPDDA 30 parts by weight
• UV22 1 part by weight
• Cyan pigment C.I. Pigment Blue 15:4 (product name: Heliogen (registered trademark) Blue D 7110 F, Sun Chemical (DIC Corporation))
• White pigment titanium oxide (product name "KRONOS 2300", manufactured by KRONOS)
• SOLSPERSE 32000 Polyethyleneimine-based dispersant (product name "SOLSPERSE 32000", manufactured by Lubrizol) ⁇ 3MPDDA: 3-methyl-1,5-pentanediol diacrylate (product name "SR341", manufactured by Sartomer)
• UV22 A mixture of 2,6-bis(1,1-dimethylethyl)-4-(phenylmethylene)-2,5-cyclohexadiene-1-one and propoxylated glycerin triacrylate (product name "IRGASTAB UV-22", manufactured by BASF)
• UV22 contains propoxylated glycerin triacrylate as another polymerizable compound, but since the amount of propoxylated glycerin triacrylate is very small, it is listed in the "polymerization inhibitor" column in the table.
• the prepared cyan pigment dispersion was mixed with the components shown in Tables 2 to 9 below so that the content of each component was the content (mass%) shown in Tables 2 to 9.
• the mixture was stirred for 20 minutes at 25°C and 5,000 rpm using a mixer (product name "L4R", manufactured by Silverson) to obtain a first ink.
• the prepared white pigment dispersion was mixed with the components shown in the tables below so that the content of each component was the content (mass%) shown in the tables.
• the mixture was stirred for 20 minutes at 25°C and 5,000 rpm using a mixer (product name "L4R", manufactured by Silverson) to obtain a second ink.
• Speedcure 7010L (manufactured by Lambson) was used to prepare the ink.
• Speedcure 7010L is a mixture of Speedcure 7010 and EOTMPTA, and the mixing ratio is 1:1 by mass.
• Speedcure 7010 is a polymerization initiator and EOTMPTA is another polymerizable compound, so they will be described in the sections on polymerization initiators and other polymerizable compounds, respectively.
• the specific bifunctional (meth)acrylate is a bifunctional (meth)acrylate having a linear or branched alkylene group having 4 to 10 carbon atoms.
• HDDA 1,6-hexanediol diacrylate (product name "Viscoat #230", manufactured by Osaka Organic Chemical Industry Co., Ltd.)
• NDDA 1,9-hexanediol diacrylate (product name "Viscoat #260", manufactured by Osaka Organic Chemical Industry Co., Ltd.)
• DDDA 1,10-decanediol diacrylate (product name "SR595", manufactured by Sartomer)
• BDDA 1,4-butanediol diacrylate (product name "Viscoat #195”, manufactured by Osaka Organic Chemical Industry Co., Ltd.)
• the specific monofunctional (meth)acrylate is a monofunctional (meth)acrylate having a hydroxyl group.
• 4-HBA 4-hydroxybutyl acrylate (product name "4-HBA", manufactured by Osaka Organic Chemical Industry Co., Ltd.)
• A-SA 2-acryloyloxyethyl succinic acid (product name: "NK Ester A-SA", manufactured by Shin-Nakamura Chemical Co., Ltd.)
• the other polymerizable compounds are polymerizable compounds other than the specific bifunctional (meth)acrylates, the specific monofunctional (meth)acrylates, and the polymerizable monomers having an acid group.
• CTFA Cyclic trimethylolpropane formal acrylate (product name "Viscoat #200", manufactured by Osaka Organic Chemical Industry Co., Ltd.)
• EOTMPTA Trimethylolpropane EO adduct triacrylate (50% by mass of "Product name: Speedcure 7010L” manufactured by Lambson)
• PEG400DA Polyethylene glycol diacrylate (product name "SR344, manufactured by Sartomer)
• UV12 N-nitroso-N-phenylhydroxylamine aluminum salt (product name "FLORSTAB UV-12", manufactured by Kromachem) UV22: As above.
• Tegorad 2010 (meth)acryloyl group-containing silicone surfactant (product name "Tegorad 2010", manufactured by Evonik, mass ratio M: 0.627119)
• Tegorad 2500 (meth)acryloyl group-containing silicone surfactant (product name "Tegorad 2500", manufactured by Evonik, mass ratio M: 0.937369)
• Tegorad 2100 (meth)acryloyl group-containing silicone surfactant (product name "Tegorad 2100", manufactured by Evonik, mass ratio M: 0.355208)
• Tegorad 2200N (meth)acryloyl group-containing silicone surfactant (product name "Tegorad 2200N", manufactured by Evonik, mass ratio M: 0.36319)
• Tegorad 2250 (meth)acryloyl group-containing silicone surfactant (product name "Tegorad 2250",
• BR113 Product name "Dianal BR113", manufactured by Mitsubishi Chemical Corporation, glass transition temperature 75°C, weight average molecular weight 30,000
• Polymer A to Polymer I Acrylic resins synthesized by the following method
• Weight average molecular weight of acrylic resin (“Mw” in Table 1)-- The weight average molecular weight of each acrylic resin was measured using high performance liquid chromatography (HPLC) (product name "HLC-8220GPC", manufactured by Tosoh Corporation). Three TSKgel SuperAWM-H columns (Tosoh Corporation, 6.0 mm ID x 15 cm) were used as columns, and N-methylpyrrolidone (with 10 mM LiBr added) was used as an eluent. The conditions were a sample concentration of 0.1 mass%, a flow rate of 0.5 mL/min, a sample injection amount of 60 ⁇ l, a measurement temperature of 40° C., and detection was performed using a differential refractive index (RI) detector.
• RI differential refractive index
• the calibration curve was prepared using eight samples of Tosoh Corporation's product names "TSK Standard Polystyrene”: "F-40", “F-20”, “F-4", "F-1”, "A-5000”, “A-2500”, "A-1000” and "n-propylbenzene” as standard samples.
• Image recording was carried out using the prepared first ink, second ink, and third ink.
• image recording A image recording was performed using only the first ink.
• image recording B image recording was performed using the first ink and the third ink.
• image recording C image recording was performed using the first ink, the second ink, and the third ink.
• the first ink (cyan ink) was applied to an acrylic substrate (Acryl, manufactured by Nippon Acryles Co., Ltd.) using an inkjet recording device (product name "CylinderJET”, manufactured by Tritec Corporation) and an inkjet head (product name "KM1800i”, manufactured by Konica Minolta, Inc.). Specifically, the first ink was applied to a rectangle of 7 cm x 5 cm under conditions of a droplet volume of 10.5 pL (picoliter) and a resolution of 600 x 600 dpi (dots per inch), and a 100% solid image with a thickness of 4 ⁇ m to 6 ⁇ m was recorded.
• ultraviolet light was irradiated at an exposure amount of 100 mJ/cm 2 to 1000 mJ/cm 2 using an LED light source attached to the inkjet recording device.
• a UV-LED irradiator with a peak wavelength of 385 nm (product name "G4B", manufactured by Kyocera Corporation) was used as the LED light source.
• the gap between the acrylic substrate surface and the inkjet head was adjusted to 0.5 mm to 1 mm, and the ejection voltage was adjusted to adjust the ejection droplet speed to 7 m/s to 9 m/s.
• a third ink (primer) was applied to the body of a PET bottle (product name "PET500 Round", manufactured by Kokugo Co., Ltd.) using an inkjet recording device (product name “CylinderJET”, manufactured by Tritec Corporation) and an inkjet head (product name "KM1800i”, manufactured by Konica Minolta, Inc.).
• the third ink was applied to a surface measuring 7 cm in the longitudinal direction of the PET bottle and 5 cm in the circumferential direction of the PET bottle under conditions of a droplet volume of 10.5 pL (picoliter) and a resolution of 600 x 600 dpi (dots per inch), thereby recording a 100% solid image having a thickness of 4 ⁇ m to 6 ⁇ m.
• the first ink cyan ink
• the third ink was applied to the surface to which the third ink had been applied, thereby recording a 100% solid image having a thickness of 4 ⁇ m to 6 ⁇ m.
• ultraviolet light was irradiated at an exposure amount of 10 mJ/cm 2 to 100 mJ/cm 2 using an LED light source attached to the inkjet recording device.
• the LED light source a UV-LED irradiator with a peak wavelength of 385 nm (product name "G4B", manufactured by Kyocera Corporation) was used.
• the PET bottle on which the image was recorded was placed in an exposure machine.
• the PET bottle was set sideways.
• the exposure machine is capable of rotating the PET bottle. While rotating the entire image recorded on the PET bottle, it was exposed to light using an LED light source.
• the third ink and the first ink were completely cured by irradiating ultraviolet light at an exposure dose of 50 mJ/cm 2 to 500 mJ/cm 2 to obtain an image recorded matter.
• the gap between the PET bottle surface and the inkjet head was adjusted to 0.5 mm to 1 mm, and the ejection voltage was adjusted to adjust the ejection droplet speed to 7 m/s to 9 m/s.
• a third ink (primer) was applied to the body of a PET bottle (product name "PET500 Round” manufactured by Kokugo Co., Ltd.) using an inkjet recording device (product name “CylinderJET” manufactured by Tritec Corporation) and an inkjet head (product name "KM1800i” manufactured by Konica Minolta, Inc.).
• the third ink was applied to a surface measuring 7 cm in the longitudinal direction of the PET bottle and 5 cm in the circumferential direction of the PET bottle under conditions of a droplet volume of 10.5 pL (picoliter) and a resolution of 600 x 600 dpi (dots per inch), thereby recording a 100% solid image having a thickness of 4 to 6 ⁇ m. Furthermore, under the same conditions as those for the application of the third ink, a second ink (white ink) was applied to the surface to which the third ink had been applied, thereby recording a 100% solid image having a thickness of 4 to 6 ⁇ m.
• a second ink white ink
• the first ink (cyan ink) was applied onto the surface to which the third ink and the second ink had been applied, and a 100% solid image with a thickness of 4 ⁇ m to 6 ⁇ m was recorded.
• ultraviolet light was irradiated at an exposure amount of 10 mJ/cm 2 to 100 mJ/cm 2 using an LED light source attached to the inkjet recording device.
• the LED light source a UV-LED irradiator (product name "G4B", manufactured by Kyocera Corporation) with a peak wavelength of 385 nm was used.
• the PET bottle on which the image was recorded was placed in an exposure machine.
• the PET bottle was set sideways.
• the exposure machine is capable of rotating the PET bottle. While rotating the entire image recorded on the PET bottle, it was exposed to light using an LED light source.
• the third ink, the second ink, and the first ink were completely cured by irradiating ultraviolet light at an exposure dose of 50 mJ/cm2 to 500 mJ/ cm2 , and an image recording was obtained.
• the gap between the PET bottle surface and the inkjet head was adjusted to 0.5 mm to 1 mm, and the ejection voltage was adjusted to adjust the ejection droplet speed to 7 m/s to 9 m/s.
• evaluations were performed on abrasion resistance, separation property, water resistance, and odor using the image recordings obtained in Image Recording A, Image Recording B, and Image Recording C.
• the ejection properties of the first ink and the second ink were evaluated.
• Evaluation 1 the evaluation results of the abrasion resistance, separation property, water resistance, and odor using the image recorded matter obtained by image recording A, as well as the evaluation results of the ejection property of the first ink, are shown as Evaluation 1.
• Evaluation 2 the results of evaluation of the scratch resistance, separation property, water resistance, and odor using the image recorded matter obtained in Image Recording B are shown.
• Evaluation 3 the evaluation results of the abrasion resistance, separation property, water resistance, and odor using the image recording matter obtained by image recording C, as well as the evaluation results of the ejection property of the second ink, are shown as Evaluation 3.
• the evaluation method is as follows.
• Each sample from which the ink film was completely peeled off was given a score of +5 points.
• Each sample in which part of the ink film peeled off was given a score of +2 points.
• Each sample in which the ink film did not peel off at all was given a minus 5 points.
• the 20 samples were scored based on the above criteria, and the separation was evaluated based on the total score. The evaluation criteria were as follows: 5: Total score is between 91 and 100 points. 4: Total score is between 81 and 90 points. 3: Total score is between 51 and 80 points. 2: The total score is between 10 and 50 points. 1: The total score is 9 or less.
• a white cotton cloth for rubbing was attached to the tip of the friction element, and the image recording surface of the image recording material was rubbed back and forth 100 times without a weight using a Gakushin type friction fastness tester (product name "AB-301", manufactured by Tester Sangyo Co., Ltd.).
• the staining of the white cotton cloth and discoloration of the image recording material were evaluated using the staining gray scale. 100% cotton Kanakin No. 3 was used as the white cotton cloth for rubbing.
• the staining of the white cotton cloth and discoloration of the image recording material in terms of dry friction fastness were evaluated according to the following evaluation criteria.
• the staining gray scale is expressed in nine stages according to JIS L 0805 (2005): 1st grade, 1-2nd grade, 2nd grade, 2-3rd grade, 3rd grade, 3-4th grade, 4th grade, 4-5th grade, and 5th grade.
• Grade 5 4 Grade 4-5 3: Grade 4 2: Grade 2-3, Grade 3, Grade 3-4, 1: 1st class, 1-2nd class, 2nd class
• the evaluation criteria were as follows: Rank 3 or higher is a level that is not problematic in practical use. 5: No peeling of the image occurred after eight operations. 4: After 8 operations, peeling of the image occurred. 3: After 7 operations, peeling of the image occurred. 2: After six operations, peeling of the image occurred. 1: Image peeling occurred after 5 or fewer operations.
• the ejection properties of the first ink or the second ink were evaluated using an inkjet recording device (product name "CylinderJET", manufactured by Tritec Corporation) and an inkjet head (product name "KM1800i”, manufactured by Konica Minolta, Inc.).
• the number of ejection nozzles before image recording was counted using a nozzle check pattern.
• the number of ejection nozzles after image recording was counted using a nozzle check pattern.
• the reduction in the number of ejection nozzles was calculated using the number of ejection nozzles before and after image recording.
• N is less than 1.
• N is greater than or equal to 1 and less than 3.
• 3 N is 3 or greater and less than 4.
• 2 N is 4 or greater and less than 7.
• 1:N is 7 or more.
• Ms/Mc refers to the mass ratio of the content of silicone surfactant having a (meth)acryloyl group to the content of acrylic resin.
• a bifunctional (meth)acrylate having a linear or branched alkylene group with 4 to 10 carbon atoms, a silicone surfactant having a (meth)acryloyl group, a colorant, and an acrylic resin having a glass transition temperature of 30°C or higher are included, and the content of the bifunctional (meth)acrylate is 20% by mass or more relative to the total amount of the active energy ray-curable inkjet ink.
• the obtained image recording material has excellent abrasion resistance and separability.
• Comparative Example 1 since an acrylic resin having a glass transition temperature of 30° C. or higher is not contained, it was found that the abrasion resistance was poor. In Comparative Example 2, since a silicone surfactant having a (meth)acryloyl group was not included, it was found that the separation property was poor. In Comparative Example 3, since the glass transition temperature of the acrylic resin was less than 30° C., it was found that the abrasion resistance was poor. It was found that Comparative Example 4 was inferior in abrasion resistance because it did not contain a bifunctional (meth)acrylate having a linear or branched alkylene group having 4 to 10 carbon atoms. In Comparative Example 5, since a bifunctional (meth)acrylate having a linear or branched alkylene group having 4 to 10 carbon atoms was not included, the ink could not be ejected and an image recording material could not be obtained.
• Example 1 since the mass ratio of the content of the silicone-based surfactant having a (meth)acryloyl group to the content of the acrylic resin in the first ink was 4 or more, it was found that the ejection properties were superior to those of Example 5. Furthermore, in Example 1, the mass ratio of the content of the silicone-based surfactant having a (meth)acryloyl group to the content of the acrylic resin in the first ink was 7 or less, and therefore it was found that the scratch resistance was superior to that of Example 4.
• Example 29 the mass ratio of the polysiloxane structure content to the polyether structure content of the silicone surfactant having a (meth)acryloyl group contained in the first ink was 0.5 or more, and therefore it was found to have superior separation properties compared to Examples 30 and 31.
• Example 8 the weight average molecular weight of the acrylic resin contained in the first ink was 5,000 to 100,000, and it was found that the abrasion resistance was superior to that of Examples 12 and 13.
• a first ink C1 (cyan ink), a first ink M1 (magenta ink), a first ink Y1 (yellow ink), a first ink K1 (black ink), a second ink W1 (white ink), and a third ink P1 (clear ink) were prepared.
• the first ink C1 the first ink in Example 1 was used.
• the second ink W1 the second ink in Example 1 was used.
• the third ink P1 the third ink in Example 1 was used.
• magenta pigment dispersion a magenta pigment dispersion, a yellow pigment dispersion, and a black pigment dispersion were prepared.
• magenta pigment Details of the magenta pigment, yellow pigment, and black pigment are as follows:
• Magenta pigment C.I. Pigment RED 122, product name "TRM-33", manufactured by Dainichi Seika Chemicals Co., Ltd.
• Yellow pigment C.I. Pigment Yellow 185, product name "Paliotol Yellow D 1155”, manufactured by Sun Chemical (DIC) Co., Ltd.
• Black pigment Carbon black, product name "MOGUL E”, manufactured by CABOT Co., Ltd.
• the prepared magenta pigment dispersion, yellow pigment dispersion, and black pigment dispersion were mixed with the components shown in Table 10 so that the content of each component was the content (mass%) shown in Table 10.
• the mixture was stirred for 20 minutes at 25°C and 5,000 rpm using a mixer (product name "L4R", manufactured by Silverson) to obtain first inks M1, Y1, and K1.
• the third ink P1 was applied onto the body of a PET bottle (product name "PET500 Round", manufactured by Kokugo Co., Ltd.) using an inkjet recording device (product name “CylinderJET”, manufactured by Tritec Corporation) and an inkjet head (product name "KM1800i”, manufactured by Konica Minolta, Inc.). Specifically, the third ink P1 was applied onto a surface measuring 7 cm in the longitudinal direction of the PET bottle and 5 cm in the circumferential direction of the PET bottle under conditions of a droplet volume of 10.5 pL (picoliters) and a resolution of 600 x 600 dpi (dots per inch), thereby recording a 100% solid image with a thickness of 4 to 6 ⁇ m.
• the second ink W1, the first ink K1, the first ink C1, the first ink M1, and the first ink Y1 were applied in this order onto the surface to which the third ink P1 had been applied, and 100% solid images with a thickness of 4 ⁇ m to 6 ⁇ m were recorded, respectively.
• the ink was irradiated with ultraviolet light at an exposure of 10 mJ/cm 2 to 100 mJ/cm 2 using an LED light source attached to the inkjet recording device.
• a UV-LED irradiator with a peak wavelength of 385 nm (product name "G4B", manufactured by Kyocera Corporation) was used. Thereafter, the PET bottle on which the image was recorded was placed in an exposure machine. The PET bottle was set sideways. The exposure machine is capable of rotating the PET bottle. The entire image recorded on the PET bottle was exposed to light using an LED light source while rotating.
• the third ink P1, the second ink W1, the first ink K1, the first ink C1, the first ink M1, and the first ink Y1 were irradiated with ultraviolet light at an exposure amount of 50 mJ/cm 2 to 500 mJ/cm 2 to completely cure the inks, thereby obtaining an image recording material.
• the gap between the PET bottle surface and the inkjet head was adjusted to 0.5 mm to 1 mm, and the ejection voltage was adjusted to adjust the ejection droplet speed to 7 m/s to 9 m/s.
• the obtained image recording material was used to evaluate the abrasion resistance, separation property, water resistance, and odor using the same evaluation method as in Example 1.
• the ejection properties of the first inks M1, Y1, and K1 were evaluated using the same evaluation method as in Example 1. All evaluation results were "5.”

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