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
  • C09D11/02—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
  • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
  • B41J11/00—Devices or arrangements  of selective printing mechanisms, e.g. ink-jet printers or thermal printers, for supporting or handling copy material in sheet or web form
  • B41J11/0015—Devices or arrangements  of selective printing mechanisms, e.g. ink-jet printers or thermal printers, for supporting or handling copy material in sheet or web form for treating before, during or after printing or for uniform coating or laminating the copy material before or after printing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
  • B41J11/00—Devices or arrangements  of selective printing mechanisms, e.g. ink-jet printers or thermal printers, for supporting or handling copy material in sheet or web form
  • B41J11/0015—Devices or arrangements  of selective printing mechanisms, e.g. ink-jet printers or thermal printers, for supporting or handling copy material in sheet or web form for treating before, during or after printing or for uniform coating or laminating the copy material before or after printing
  • B41J11/002—Curing or drying the ink on the copy materials, e.g. by heating or irradiating
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
  • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
  • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
  • B41J2/01—Ink jet
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
  • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
  • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
  • B41J2/01—Ink jet
  • B41J2/21—Ink jet for multi-colour printing
  • B41J2/2107—Ink jet for multi-colour printing characterised by the ink properties
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
  • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
  • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
  • B41J2/01—Ink jet
  • B41J2/21—Ink jet for multi-colour printing
  • B41J2/2107—Ink jet for multi-colour printing characterised by the ink properties
  • B41J2/2114—Ejecting specialized liquids, e.g. transparent or processing liquids
• • 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
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK  ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
  • C09C1/00—Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK  ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
  • C09C3/00—Treatment in general of inorganic materials, other than fibrous fillers, to enhance their pigmenting or filling properties
  • C09C3/10—Treatment with macromolecular organic compounds
• • 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

• the present disclosure relates to an active energy ray-curable inkjet ink and an image recording method.
• Japanese Unexamined Patent Application Publication No. 2016-11426 describes a photocurable ink that is used for droplet ejection in an inkjet method, and a surface-treated metal obtained by coating the surface of metal particles with a coating of a phosphoric acid ester compound.
• a light comprising particles and a polymerizable compound, wherein the content of the free phosphoric acid ester compound is less than 0.01% by mass, and the phosphoric acid ester compound is fatty acid triglyceride phosphate.
• a curable ink is described.
• JP 2021-66812 describes inkjet inks containing metallic pigments including metallic indium and/or metallic chromium.
• Japanese Patent Application Laid-Open No. 2021-100994 describes an active energy ray-curable ink characterized by containing scale-like indium particles.
• an active energy ray-curable inkjet ink and an image recording method capable of recording an image with excellent metallic luster. is provided.
• the present disclosure includes the following aspects. ⁇ 1> including metal particles and a polymerizable compound,
• the metal particles have a specific gravity of 3 or more, In the cross section of an ink film with a thickness of 1 ⁇ m or more obtained by curing a liquid in which the content of metal particles in the active energy ray-curable inkjet ink is adjusted to 0.5% by mass, from the surface of the ink film to the inside of the ink film 50% by mass or more of the total mass of the metal particles exists in a region within 100 nm toward An active energy ray-curable inkjet ink having a surface tension of 30 mN/m or more.
• ⁇ 2> The activity according to ⁇ 1>, wherein at least part of the surface of the metal particles is coated with at least one polymer selected from the group consisting of cellulose acetate butyrate, cellulose acetate propionate, and cellulose acetate.
• Energy ray curable inkjet ink ⁇ 3> The active energy ray-curable type according to ⁇ 1> or ⁇ 2>, wherein 70% by mass or more of the total mass of the metal particles is present in a region within 100 nm from the surface of the ink film toward the inside of the ink film in cross section. inkjet ink.
• ⁇ 4> The active energy ray-curable inkjet ink according to any one of ⁇ 1> to ⁇ 3>, wherein the metal particles contain indium.
• ⁇ 5> The active energy ray-curable inkjet ink according to any one of ⁇ 1> to ⁇ 4>, wherein the metal particles have an average particle size of 0.05 ⁇ m to 0.5 ⁇ m.
• ⁇ 6> The active energy ray-curable inkjet ink according to any one of ⁇ 1> to ⁇ 5>, wherein the metal particles have a contour in which straight lines and curved lines are combined in plan view.
• ⁇ 7> The active energy ray-curable inkjet ink according to any one of ⁇ 1> to ⁇ 6>, which has a surface tension of 40 mN/m or less.
• ⁇ 8> The active energy ray-curable inkjet ink according to any one of ⁇ 1> to ⁇ 7>, which has a surface tension of 32 mN/m to 38 mN/m.
• ⁇ 9> The active energy ray-curable inkjet ink according to any one of ⁇ 1> to ⁇ 8>, which does not contain a surfactant or has a surfactant content of less than 0.01% by mass.
• the active energy ray-curable inkjet ink according to any one of ⁇ 1> to ⁇ 9> is used, A step of applying an active energy ray-curable inkjet ink onto a substrate using an inkjet recording method; A step of curing the active energy ray-curable inkjet ink applied to the substrate by irradiation with an active energy ray A to record an image;
• An image recording method comprising: ⁇ 11>
• the process of recording an image includes: A step of temporarily curing the active energy ray-curable inkjet ink applied on the substrate by irradiation with an active energy ray P whose irradiation energy is smaller than that of the active energy ray A;
• the image recording method according to ⁇ 10> comprising a step of curing the ink film formed by temporary curing of the active energy ray-curable inkjet ink by irradiation with the active energy ray A to record an image.
• an active energy ray-curable inkjet ink and an image recording method capable of recording an image with excellent metallic luster are provided.
• the numerical range indicated using “to” means a range including 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 stepwise.
• the upper limit or lower limit described in a certain numerical range may be replaced with the values shown in the examples.
• the amount of each component in the composition refers to the total amount of the multiple substances present in the composition when there are multiple substances corresponding to each component in the composition, unless otherwise specified. means In the present specification, 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. be
• image means film in general, and “image recording” means formation of an image (that is, film).
• image recording means formation of an image (that is, film).
• image in this specification also includes a solid image.
• (meth)acrylate is a concept that includes both acrylate and methacrylate
• (meth)acryloyl group is a concept that includes both acryloyl group and methacryloyl group
• (meth) ) acrylic acid is a concept that includes both acrylic acid and methacrylic acid.
• An active energy ray-curable inkjet ink (hereinafter also simply referred to as "ink") of the present disclosure contains metal particles, a polymerizable compound, and a polymerization inhibitor, and the metal particles have a specific gravity of 3 or more, In a cross section of an ink film having a thickness of 1 ⁇ m or more obtained by curing a liquid in which the content of metal particles in the ink is adjusted to 0.5% by mass, a thickness within 100 nm from the surface of the ink film toward the inside of the ink film At least 50% by mass of the total mass of the metal particles is present in the region, and the surface tension is at least 30 mN/m.
• the ink of the present disclosure contains metal particles, and in a cross section of an ink film having a thickness of 1 ⁇ m or more obtained by curing a liquid in which the content of metal particles in the ink is adjusted to 0.5% by mass, the surface of the ink film within 100 nm toward the inside of the ink film (in the case of an image obtained by applying ink on a substrate, a region of up to 100 nm inward from the surface of the ink film in a cross section perpendicular to the substrate) , there are more than 50% by mass of particles out of the total mass of metal particles. That is, in the ink film obtained by curing the ink of the present disclosure, the metal particles are unevenly distributed on the surface of the ink film. Since many metal particles are present on the surface of the ink film, an image with excellent metallic luster can be obtained.
• the ink of the present disclosure has a surface tension of 30 mN/m or more, and metal particles easily migrate to the gas-liquid interface.
• the metal particles are unevenly distributed on the surface of the ink film by curing the ink while the metal particles are gathered at the air-liquid interface. Since many metal particles are present on the surface of the ink film, an image with excellent metallic luster can be obtained.
• the ink of the present disclosure contains a polymerization inhibitor, the progress of the polymerization reaction in the ink is suppressed, metal particles tend to gather at the gas-liquid interface in the ink, and the glossiness of the image is improved.
• Japanese Patent Application Laid-Open No. 2016-11426 does not pay attention to the position of the metal particles in the ink film.
• the ink of the present disclosure is an active energy ray-curable ink. That is, the ink of the present disclosure is cured by irradiation with active energy rays.
• active energy rays include ⁇ rays, ⁇ rays, electron beams, ultraviolet rays, and visible rays. Among them, the active energy rays are preferably ultraviolet rays.
• the ink of the present disclosure is preferably an ultraviolet curable ink.
• the ink of the present disclosure is an inkjet ink. That is, the ink of the present disclosure is an ink used for ejection by an inkjet recording method.
• the ink of the present disclosure contains at least one metal particle.
• the shape of the metal particles is not particularly limited, and examples include circular, elliptical, rectangular, scaly, and irregular shapes. Among them, the shape of the metal particles is preferably scaly.
• the term “scale-like” means a thin and flat shape, and is a concept that includes plate-like and curved plate-like shapes.
• metals that make up metal particles include indium, nickel, aluminum, iron, chromium, silver, gold, platinum, tin, zinc, titanium, and copper.
• the number of metals contained in the metal particles may be one, or two or more.
• the metal particles preferably contain indium or nickel, and more preferably contain indium, from the viewpoint of further improving metallic luster.
• the metal particles may contain non-metallic elements (eg, oxygen (O), nitrogen (N), carbon (C), etc.).
• non-metallic elements eg, oxygen (O), nitrogen (N), carbon (C), etc.
• the content of metal with respect to the total amount of metal particles is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 80% by mass or more.
• the above content may be 100% by mass.
• the average particle size of the metal particles is not particularly limited, it is preferably 0.05 ⁇ m to 0.5 ⁇ m, more preferably 0.1 ⁇ m to 0.4 ⁇ m.
• the average particle size is 0.05 ⁇ m or more, the metallic glossiness of the image is improved.
• the average particle size is 0.5 ⁇ m or less, the storage stability and ejection properties of the ink are improved.
• the average particle size here means the average value of the primary particle sizes of metal particles (average primary particle size).
• the average particle size of metal particles is measured using a particle size distribution analyzer.
• the average particle diameter of the metal particles is calculated by measuring the 50% volume cumulative diameter (D50) three times using a laser diffraction/scattering particle size distribution analyzer and calculating the average value of the three measurements.
• a laser diffraction/scattering particle size distribution analyzer for example, product name "LA-960" manufactured by Horiba, Ltd. can be used.
• the average particle size of the metal particles is the average particle size when the shape of the metal particles is assumed to be spherical.
• the average aspect ratio of the metal particles is not particularly limited, it is preferably 5-100, more preferably 5-50, even more preferably 5-20.
• the average aspect ratio is 5 or more, the metallic luster of the image is improved.
• the average aspect ratio is 100 or less, the production aptitude of the metal particles is improved.
• the average aspect ratio means the ratio of the average equivalent circle diameter to the average thickness.
• the average equivalent circle diameter and average thickness of metal particles are measured using the following methods.
• a metal particle dispersion liquid (metal particle concentration: 20% by mass) containing metal particles as a dispersoid and propylene glycol monomethyl ether (PGME) as a dispersion medium is prepared as a liquid sample.
• This liquid sample is applied onto a polyethylene terephthalate (PET) film to obtain a coating film.
• PET polyethylene terephthalate
• the surface of the coating film was observed with a scanning electron microscope (SEM) (for example, Nova200 type FIB-SEM manufactured by Thermo Fisher Scientific Co., hereinafter the same), and from the obtained SEM image, 50 metal particles and measure the equivalent circle diameter of each metal particle.
• SEM scanning electron microscope
• the arithmetic average value of the equivalent circle diameters of 50 metal particles is obtained and taken as the average equivalent circle diameter of the metal particles.
• the cross section of the coating film is observed by SEM, 50 metal particles are selected from the obtained SEM image, and the thickness of each metal particle is measured.
• An arithmetic mean value of the thicknesses of 50 metal particles is obtained and taken as the average thickness of the metal particles.
• the average thickness of the metal particles is not particularly limited, it is preferably 10 nm to 50 nm, more preferably 15 nm to 45 nm, even more preferably 20 nm to 40 nm, from the viewpoint of improving the metallic luster of the image. preferable.
• planar shape of the metal particles examples include a polygonal shape, an elliptical shape, and an irregular shape. From the viewpoint of improving the metallic luster of the image, the metal particles preferably have a contour in which a straight line and a curved line are combined in plan view. Moreover, it is preferable that the metal particles have an R-shaped contour in plan view.
• an R shape means a shape in which there are no vertices where two sides meet.
• the metal particles preferably have rounded contours in plan view. Note that the outline of the metal particles in a plan view may have concave portions.
• At least part of the surface of the metal particles is preferably coated with a polymer, and the metal particles are coated with at least one polymer selected from the group consisting of cellulose acetate butyrate, cellulose acetate propionate, and cellulose acetate. It is more preferable to be
• the surface energy of the polymer pushes the metal particles up to the air-liquid interface of the ink together with the polymer. Since the metal particles gather at the gas-liquid interface of the ink and are unevenly distributed on the surface of the ink film after the ink is cured, an image with excellent metallic luster can be obtained.
• the metal particles coated with the polymer are preferably peeled pieces of a metal film.
• the peeled piece of the metal film can be obtained, for example, by the following method.
• At least one polymer selected from the group consisting of cellulose acetate butyrate, cellulose acetate propionate, and cellulose acetate is applied onto the substrate to form a polymer layer.
• a metal film containing metal is formed on the polymer layer.
• the polymer layer is dissolved and the metal film is peeled off.
• Metal particles are obtained by pulverizing or crushing the metal film.
• the metal film may be peeled off with the polymer layer adsorbed on one side.
• Metal particles coated with the polymer are obtained by pulverizing or crushing the metal film with the polymer layer adsorbed on one surface thereof.
• Vapor deposition, sputtering, etc. can be mentioned as methods for forming a metal film.
• a metal film containing indium does not form a continuous film during vapor deposition, but forms a sea-island structure in which islands are scattered. Therefore, metal particles can be obtained only by pulverization without applying a large force.
• a peeled piece of the metal film containing indium (that is, a metal particle containing indium) has an R-shaped contour in plan view.
• a metal film containing aluminum, nickel, or silver becomes a continuous film when deposited. Therefore, crushing treatment is required to obtain metal particles. Sharp edges tend to be present in the peeled pieces after the crushing process.
• the metal particles have a specific gravity of 3 or more from the viewpoint of improving the metallic luster of the image.
• the upper limit of the specific gravity is not particularly limited, it is, for example, 12 from the viewpoint of improving the metallic luster of the image.
• the specific gravity of metal particles refers to the specific gravity of the metal that constitutes the metal particles, and when the metal particles are an alloy, it refers to the specific gravity of the alloy.
• the specific gravity of metal particles is measured using the method described in JIS Z8807:2012. It is also possible to identify the type of metal by elemental analysis and adopt the literature value of the metal.
• metal particles are metal particles having the following properties.
• an ink film having a thickness of 1 ⁇ m or more obtained by curing a liquid in which the content of metal particles in the ink is adjusted to 0.5% by mass a thickness within 100 nm from the surface of the ink film toward the inside of the ink film At least 50% by weight of the total weight of the metal particles is present in the region.
• the ink contains metal particles having a property of 50% by mass or more on the surface of the ink film, an image with excellent metallic luster can be obtained.
• the cross section of the ink film means the cross section in the thickness direction of the ink film (that is, the cut surface when the image is cut along a plane perpendicular to the surface of the base material).
• the ink is a liquid in which the content of metal particles in the ink is adjusted to 0.5% by mass.
• the ink is diluted with a diluent.
• the polymerizable compound having the highest content in the ink is selected.
• two or more polymerizable compounds having the highest content are present, they are used equally.
• a liquid in which the content of metal particles in the ink was adjusted to 0.5% by mass was dropped onto the substrate, and was coated with K hand coater No. 1.
• a ratio of the number Y to the number X is calculated, and it is determined whether or not the calculated value is 50% or more.
• this confirmation method it is assumed that each metal particle has the same mass, and the existence ratio based on the number of metal particles is equivalent to the existence ratio based on the mass of the metal particles.
• metal particles are preferably present in an amount of 70% by mass or more, more preferably 80% by mass or more.
• the upper limit of the content ratio is not particularly limited, and may be 100% by mass.
• the content of the metal particles is preferably 0.5% by mass to 10% by mass, more preferably 1.0% by mass to 8.0% by mass, relative to the total amount of the ink.
• the ink of the present disclosure contains at least one polymerizable compound.
• a polymerizable compound is a compound having a polymerizable group.
• the polymerizable group is preferably a radically polymerizable group or a cationic polymerizable group, more preferably a radically polymerizable group.
• the polymerizable compound may have only one polymerizable group, or may have two or more polymerizable groups.
• a radically polymerizable compound is preferred.
• the radically polymerizable group is preferably an ethylenically unsaturated group, more preferably at least one selected from the group consisting of (meth)acryloyl groups, allyl groups, styryl groups, and vinyl groups, ( More preferably, it is a meth)acryloyl group.
• Cationically polymerizable groups include epoxy groups and oxetanyl groups.
• the polymerizable compound may be a polymerizable monomer, a polymerizable polymer, or a combination of a polymerizable monomer and a polymerizable polymer.
• the polymerizable monomer means a polymerizable compound having a molecular weight of less than 1000
• the polymerizable polymer means a polymerizable compound having a weight average molecular weight (Mw) of 1000 or more.
• Mw weight average molecular weight
• the concept of "polymerizable polymer" in the present disclosure also includes so-called oligomers.
• the weight average molecular weight (Mw) of the polymerizable compound is preferably 30,000 or less, more preferably 20,000 or less, even more preferably 10,000 or less.
• Examples of the lower limit of Mw of the polymerizable compound include 50, 60, and 70.
• weight average molecular weight means a value measured by gel permeation chromatography (GPC).
• Measurement by GPC uses HLC (registered trademark)-8020GPC (Tosoh Corporation) as a measuring device, and TSKgel (registered trademark) Super Multipore HZ-H (4.6 mm ID ⁇ 15 cm, Tosoh Corporation) as a column. and THF (tetrahydrofuran) is used as an eluent.
• the measurement conditions are a sample concentration of 0.45% by mass, a flow rate of 0.35 ml/min, a sample injection amount of 10 ⁇ L, a measurement temperature of 40° C., and an RI detector.
• the polymerizable compound may be a monofunctional polymerizable compound or a polyfunctional polymerizable compound (that is, a bifunctional or higher polymerizable compound).
• the monofunctional polymerizable compound means a compound containing only one polymerizable group in one molecule
• the polyfunctional polymerizable compound means a compound containing two or more polymerizable groups in one molecule. means.
• Monofunctional polymerizable compounds include, for example, 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, and 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 acrylates, 4-n-butylcyclohexyl (meth)acrylate, 4-tert-butylcyclohexyl (meth)acrylate, bornyl (meth)acrylate, isobornyl (meth)acrylate, 2-ethylhexyl diglycol (meth)acrylate, butoxyethyl ( meth) acrylate, 2-chloroethyl (meth) acrylate, 4-bromobutyl (meth) acrylate, cyanoethyl (meth) acrylate, benzyl (meth) acrylate,
• Examples of monofunctional (meth)acrylamides include (meth)acrylamide, N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-propyl(meth)acrylamide, Nn-butyl(meth)acrylamide, Nt-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, vinylbenzoic acid methyl ester, 3-methyl Styrene, 4-methylstyrene, 3-ethylstyrene, 4-ethylstyrene, 3-propylstyrene, 4-propylstyrene, 3-butylstyrene, 4-butylstyrene, 3-hexylstyrene, 4-hexylstyrene, 3-octyl Styrene, 4-octylstyrene, 3-(2-ethylhexyl)styrene, 4-(2-ethylhexyl)styrene
• Monofunctional vinyl ethers include, for example, 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-methyl Cyclohexyl methyl 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, tetrahydro Furfuryl vinyl ether, 2-hydroxyethyl vinyl ether, 2-hydroxy
• Examples of monofunctional N-vinyl compounds include N-vinylcaprolactam and N-vinylpyrrolidone.
• a polyfunctional polymerizable compound is a polymerizable compound having two or more functionalities.
• bifunctional polymerizable compounds include bifunctional (meth)acrylates, bifunctional vinyl ethers, and bifunctional polymerizable compounds containing a vinyl ether group and a (meth)acryloyl group.
• bifunctional (meth)acrylates include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, and dipropylene glycol di(meth)acrylate.
• acrylates tripropylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate ) acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, hexanediol di(meth)acrylate, heptanediol 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, octanediol di(meth)acrylate,
• bifunctional 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.
• bifunctional polymerizable compounds containing a vinyl ether group and a (meth)acryloyl group examples include 2-(2-vinyloxyethoxy)ethyl (meth)acrylate.
• tri- or higher functional polymerizable compounds include tri- or higher functional (meth)acrylates and tri- or higher functional vinyl ethers.
• Tri- or higher functional (meth)acrylates include, for example, trimethylolethane tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, EO-modified trimethylolpropane tri(meth)acrylate, PO-modified trimethylolpropane tri(meth)acrylate, ) acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tri(meth)acrylate Acryloyloxyethoxytrimethylolpropane, glycerin polyglycidyl ether poly(meth)acrylate, and tris(2-acryloyloxyethyl)isocyanurate.
• tri- or higher functional vinyl ethers examples include trimethylolethane trivinyl ether, trimethylolpropane trivinyl ether, ditrimethylolpropane tetravinyl ether, glycerin trivinyl ether, pentaerythritol tetravinyl ether, dipentaerythritol pentavinyl ether, dipentaerythritol hexavinyl ether, and EO.
• Modified trimethylolpropane trivinyl ether PO-modified trimethylolpropane trivinyl ether, EO-modified ditrimethylolpropane tetravinyl ether, PO-modified ditrimethylolpropane tetravinyl ether, EO-modified pentaerythritol tetravinyl ether, PO-modified pentaerythritol tetravinyl ether, EO-modified dipentaerythritol hexavinyl ether and PO-modified dipentaerythritol hexavinyl ether.
• Urethane (meth)acrylates can also be mentioned as polyfunctional polymerizable compounds.
• Urethane (meth)acrylate is preferably a compound containing two or three (meth)acryloyl groups and at least one urethane bond.
• Urethane (meth)acrylates include urethane (meth)acrylates that are reaction products of bifunctional isocyanate compounds, hydroxyl group-containing (meth)acrylates (and other active hydrogen group-containing compounds, if necessary).
• bifunctional isocyanate compounds include methylene diisocyanate, dimethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, dipropyl ether diisocyanate, 2,2-dimethylpentane diisocyanate, and 3-methoxyhexane diisocyanate.
• hydroxyl group-containing (meth)acrylates examples include 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxy Butyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, phenylglycidyl ether (meth)acrylate, and pentaerythritol (meth)triacrylate, dipentaerythritol penta(meth)acrylate.
• Polyfunctional polymerizable compounds also include silicone compounds with ethylenically unsaturated groups.
• the silicone compound having an ethylenically unsaturated group is preferably a silicone polyether acrylate, more preferably a polyfunctional silicone polyether acrylate, and even more preferably a penta- to hexa-functional silicone polyether acrylate. .
• Epoxy (meth)acrylate is also included as the above-mentioned bifunctional polymerizable compound and trifunctional or higher polymerizable compound.
• epoxy (meth)acrylate is a reaction in which a carboxy group in (meth)acrylic acid reacts with two or three epoxy groups in an epoxy compound containing two or three epoxy groups. means product. That is, the structure of epoxy (meth)acrylate does not contain an epoxy group.
• Epoxy (meth)acrylates include reaction products of (meth)acrylic acid and epoxy resins.
• epoxy resins include bisphenol A type epoxy resins and cresol novolac type epoxy resins.
• the content of the polymerizable compound is preferably 50% by mass to 95% by mass, more preferably 60% by mass to 90% by mass, relative to the total amount of the ink.
• the ink of the present disclosure may contain at least one organic solvent.
• organic solvent a known organic solvent that can be used for ink can be used.
• organic solvents include, for example, organic solvents described in New Edition Solvent Pocket Book (edited by the Society of Organic Synthetic Chemistry, published in 1994).
• organic solvents examples include (poly)alkylene glycols such as ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, triethylene glycol monomethyl ether, propylene glycol monomethyl ether (PGME), dipropylene glycol monomethyl ether, and tripropylene glycol monomethyl ether.
• polyalkylene glycols such as ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, triethylene glycol monomethyl ether, propylene glycol monomethyl ether (PGME), dipropylene glycol monomethyl ether, and tripropylene glycol monomethyl ether.
• (poly)alkylene glycol dialkyl ethers such as ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dipropylene glycol diethyl ether, tetraethylene glycol dimethyl ether;
• (poly)alkylene glycol acetates such as diethylene glycol acetate;
• (poly)alkylene glycol diacetates such as ethylene glycol diacetate and propylene glycol diacetate;
• (poly)alkylene glycol monoalkyl ether acetates such as ethylene glycol monobutyl ether acetate and propylene glycol monomethyl ether acetate; ketones such as methyl ethyl ketone and cyclohexanone; Lactones such as ⁇ -butyrolactone; Esters such as ethyl acetate, propyl acetate, butyl acetate, 3-methoxybutyl
• the (poly)alkylene glycol is preferably (poly)ethylene glycol and/or (poly)propylene glycol.
• the content of the organic solvent is preferably 0.1% by mass to 30% by mass, more preferably 0.1% by mass to 20% by mass, relative to the total amount of the ink.
• the ink of the present disclosure preferably contains at least one photopolymerization initiator.
• the photopolymerization initiator is preferably a radical polymerization initiator that generates radicals when irradiated with light.
• radical polymerization initiators include (a) alkylphenone compounds, (b) acylphosphine oxide compounds, (c) aromatic onium salt compounds, (d) organic peroxides, (e) thio compounds (e.g., isopropylthioxanthone, etc. thioxanthone compound), (f) hexaarylbiimidazole compound, (g) ketoxime ester compound, (h) borate compound, (i) azinium compound, (j) metallocene compound, (k) active ester compound, (l) compounds having a carbon-halogen bond and (m) alkylamine compounds.
• alkylphenone compounds examples include (a) alkylphenone compounds, (b) acylphosphine oxide compounds, (c) aromatic onium salt compounds, (d) organic peroxides, (e) thio compounds (e.g., isopropylthioxanthone, etc. thioxanthone compound), (
• the photopolymerization initiator preferably contains an acylphosphine oxide compound.
• Acylphosphine oxide compounds include bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, bis(2,6-dimethylbenzoyl)phenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2-methoxy Phenylphosphine oxide, bis(2,6-dimethylbenzoyl)-2-methoxyphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,4-dimethoxyphenylphosphine oxide, bis(2,6-dimethylbenzoyl) )-2,4-dimethoxyphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,4-dipentyloxyphenylphosphine oxide, bis(2,6-dimethylbenzoyl)-2,4-dipentyloxyphenyl Phosphine oxide, 2,4,6-trimethylbenzoylethoxyphenylphosphine oxide,
• the acylphosphine oxide compound is preferably bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide or 2,4,6-trimethylbenzoyldiphenylphosphine oxide.
• the photopolymerization initiator may be a low-molecular-weight photopolymerization initiator with a molecular weight of less than 500, or a high-molecular-weight photopolymerization initiator with a molecular weight of 500 or more.
• the molecular weight of the photopolymerization initiator is preferably 500-3000, more preferably 700-2500, and even more preferably 900-2100.
• JP-A-2017-105902 paragraph 0038, etc.
• JP-A-2017-522364 paragraphs 0017 to 0053.
• radical polymerization initiators examples include: Omnirad TPO H, 819, 369, 907 and 2959 (manufactured by IGM Resins B.V.), which are commercial products of low-molecular-weight radical polymerization initiators; and commercial products of high-molecular-weight radical polymerization initiators.
• Omnipole 910, TX, 9210 manufactured by IGM Resins B.V.
• Speedcure 7005, 7010, 7010L, 7040 manufactured by Lambson.
• the ink of the present disclosure may contain two or more photopolymerization initiators with different absorption wavelengths.
• pinning exposure (temporary curing) with active energy rays P for example, long-wavelength ultraviolet light
• curing exposure (main curing) with active energy rays A are performed in this order.
• the ink may contain a photopolymerization initiator P that easily absorbs the active energy ray P and a photopolymerization initiator A that easily absorbs the active energy ray A.
• the metallic luster of the image and the sharpness of the image can be further improved.
• the content of the photopolymerization initiator is preferably 1% by mass to 20% by mass, more preferably 2% by mass to 15% by mass, and 3% by mass to 10% by mass, relative to the total amount of the ink. is more preferable, and 3% by mass to 8% by mass is particularly preferable.
• the ink of the present disclosure is an ink that is cured by electron beams as active energy rays
• the content of the photopolymerization initiator with respect to the total amount of the ink may be less than 1% by mass.
• the content of the photopolymerization initiator relative to the total amount of the ink is less than 1% by mass means that the ink does not contain a photopolymerization initiator, or even if it contains a photopolymerization initiator It means that the initiator content is less than 1% by weight.
• the inks of the present disclosure may contain at least one surfactant.
• surfactants include those described in JP-A-62-173463 and JP-A-62-183457.
• surfactants include anionic surfactants such as dialkylsulfosuccinates, alkylnaphthalenesulfonates, and fatty acid salts; polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, acetylene glycol, polyoxyethylene •
• Nonionic surfactants such as polyoxypropylene block copolymers; and cationic surfactants such as alkylamine salts and quaternary ammonium salts.
• the surfactant may be a fluorosurfactant or a silicone surfactant.
• the ink of the present disclosure preferably does not contain a surfactant or has a surfactant content of less than 0.01% by mass.
• the ink of the present disclosure contains at least one polymerization inhibitor.
• Metal particles tend to induce the polymerization reaction of the polymerizable compound, but if the ink contains a polymerization inhibitor, the progress of the polymerization reaction in the ink is suppressed. As a result, the metal particles tend to gather at the air-liquid interface in the ink, improving the glossiness of the image.
• the stability of the ink over time is also improved.
• the progress of the polymerization reaction in the ink is suppressed, the formation of coarse particles in the ink is suppressed, the ejection properties are improved, and as a result, the image quality is also improved.
• Polymerization inhibitors include p-methoxyphenol, quinones (e.g., hydroquinone, benzoquinone, methoxybenzoquinone, etc.), phenothiazine, catechols, alkylphenols (e.g., dibutylhydroxytoluene (BHT), etc.), alkylbisphenols, dimethyldithiocarbamine.
• quinones e.g., hydroquinone, benzoquinone, methoxybenzoquinone, etc.
• phenothiazine e.g., catechols
• alkylphenols e.g., dibutylhydroxytoluene (BHT), etc.
• alkylbisphenols e.g., dimethyldithiocarbamine.
• the polymerization inhibitor is preferably at least one selected from p-methoxyphenol, catechols, quinones, alkylphenols, TEMPO, TEMPOL, and tris(N-nitroso-N-phenylhydroxylamine) aluminum salt, and p -Methoxyphenol, hydroquinone, benzoquinone, BHT, TEMPO, TEMPOL, and tris(N-nitroso-N-phenylhydroxylamine) aluminum salt is more preferred.
• the content of the polymerization inhibitor is preferably 0.01% by mass to 5.0% by mass, more preferably 0.05% by mass to 4.0% by mass, based on the total amount of the ink. is more preferred, and 0.1% by mass to 3.0% by mass is particularly preferred.
• the inks of the present disclosure may optionally contain other components than those mentioned above.
• Other components include coloring agents (eg, pigments, dyes), resins, dispersants, waxes, antioxidants, anti-fading agents, conductive salts, basic compounds, and the like.
• the surface tension of the ink of the present disclosure is 30 mN/m or more.
• the metal particles tend to gather at the gas-liquid interface, and the metal particles are unevenly distributed on the image surface, thereby improving the metallic luster of the image.
• the surface tension of the ink is preferably 40 mN/m or less. That is, the surface tension of the ink is preferably 30 mN/m to 40 mN/m, more preferably 32 mN/m to 38 mN/m.
• Surface tension means the value measured at 25°C.
• Surface tension is a value measured using a surface tensiometer, and can be measured using, for example, the product name "Automatic Surface Tentiometer CBVP-Z (manufactured by Kyowa Interface Science Co., Ltd.)".
• the viscosity of the ink of the present disclosure is preferably 5 mPa ⁇ s to 50 mPa ⁇ s, more preferably 10 mPa ⁇ s to 30 mPa ⁇ s, even more preferably 10 mPa ⁇ s to 25 mPa ⁇ s.
• Viscosity means the value measured at 25°C. Viscosity is a value measured using a viscometer, and can be measured using, for example, VISCOMETER RE-85L (manufactured by Toki Sangyo Co., Ltd.).
• the ink of the present disclosure may be combined with an undercoat liquid to form an ink set.
• the undercoat liquid is a liquid that is applied onto the substrate prior to the ink of the present disclosure, and is a liquid for forming the undercoat layer. This makes it possible to produce an image record having an undercoat layer between the image and the substrate. An image record having an undercoat layer can form a highly sharp image. In addition, the adhesion between the image and the substrate is also more excellent.
• the undercoat liquid preferably does not contain metal particles but contains a polymerizable compound.
• the undercoat liquid may contain other components (for example, a photopolymerization initiator) other than the polymerizable compound.
• a photopolymerization initiator for example, a photopolymerization initiator
• the undercoat liquid preferably does not substantially contain colorants (eg, pigments). Specifically, the content of the coloring agent with respect to the total amount of the undercoat liquid is preferably less than 1% by mass.
• the image recording method of the present disclosure comprises a step of applying the above-described ink onto a substrate using an inkjet recording method (hereinafter also referred to as an “ink application step”), and applying the ink applied onto the substrate with an active and a step of recording an image by curing by irradiation with the energy beam A (hereinafter referred to as an image recording step).
• the ink application step includes applying the above ink onto the substrate using an inkjet recording method.
• the substrate may be a permeable substrate such as paper or a non-permeable substrate.
• a permeable substrate such as paper or a non-permeable substrate.
• a non-permeable substrate refers to a substrate having a water absorption (% by weight, 24 hr.) of less than 0.2 according to ASTM test method ASTM D570.
• a permeable substrate refers to a substrate having a water absorption (mass %, 24 hr.) of 0.2 or higher according to ASTM test method ASTM D570.
• impermeable substrates examples include glass, quartz, plastic films, and leather.
• resins constituting plastic films include cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, acrylic resins, chlorinated polyolefin resins, polyethersulfone resins, polyethylene terephthalate ( PET), polyethylene naphthalate, nylon, polyethylene (PS), polystyrene, polypropylene (PP), polycycloolefin resin, polyimide resin, polycarbonate (PC) resin, and polyvinyl acetal.
• the plastic film may be a film containing only one type of these resins, or a film containing two or more types.
• leather examples include natural leather (also called “genuine leather”), synthetic leather (eg, PVC (polyvinyl chloride) leather, PU (polyurethane) leather), and the like.
• natural leather also called “genuine leather”
• synthetic leather eg, PVC (polyvinyl chloride) leather
• PU polyurethane
• paragraphs 0163 to 0165 of JP-A-2009-058750 can be referred to.
• the thickness of the impermeable substrate is not particularly limited, it is preferably 10 ⁇ m to 2000 ⁇ m, more preferably 20 ⁇ m to 1000 ⁇ m, even more preferably 30 ⁇ m to 500 ⁇ m, even more preferably 30 ⁇ m to 400 ⁇ m. Especially preferred.
• the permeable substrate includes paper and cloth.
• paper examples include non-coated paper (for example, high-quality paper), coated paper, paperboard, liner paper used for corrugated cardboard, cloth, and the like.
• the paperboard may be coated with a coating layer.
• coated paper and paperboard coated with a coating layer are preferable.
• Coated paper and paperboard coated with a coat layer have a moderate degree of ink permeation, so that a recorded image tends to exhibit a stronger metallic luster.
• the inkjet recording method is not particularly limited as long as it is a method capable of recording an image, and known methods can be used.
• Inkjet recording methods include, for example, a charge control method that uses electrostatic attraction to eject ink, a drop-on-demand method (pressure pulse method) that uses vibration pressure of a piezo element, and an ink that converts an electrical signal into an acoustic beam.
• Acoustic inkjet method in which ink is ejected using radiation pressure by irradiating to the surface
• thermal inkjet (bubble jet (registered trademark)) method in which ink is heated to form bubbles and the resulting pressure is used. .
• the inkjet head used in the inkjet recording method a short serial head is used, and the shuttle method performs recording while scanning the head in the width direction of the substrate, and the recording elements are arranged corresponding to the entire side of the substrate. and a line method using a line head that has been developed.
• patterns can be formed on the entire surface of the base material by scanning the base material in a direction that intersects the direction in which the recording elements are arranged, eliminating the need for a transport system such as a carriage for scanning the short head.
• the line method eliminates the need for complicated scanning control of the movement of the carriage and the base material, and only the base material moves.
• the droplet volume of ink 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.
• the image recording step includes curing the ink applied on the substrate by irradiation with active energy rays A to record an image.
• the active energy ray A is applied to the ink applied to the base material to polymerize the polymerizable compound in the ink film formed by the ink to cure the ink film, thereby forming an image. is obtained.
• the active energy rays are preferably ultraviolet rays.
• the peak wavelength of ultraviolet rays is, for example, preferably 200 nm to 405 nm, more preferably 250 nm to 400 nm, even more preferably 300 nm to 400 nm.
• UV-LEDs light-emitting diodes
• UV-LDs laser diodes
• the light source for ultraviolet irradiation is preferably a metal halide lamp, a high-pressure mercury lamp, a medium-pressure mercury lamp, a low-pressure mercury lamp, or a UV-LED.
• the content of the photopolymerization initiator in the ink is less than 1% by mass with respect to the total amount of the ink, and the curing is performed by irradiation with an electron beam as the active energy ray A.
• the content of the photopolymerization initiator is less than 1% by mass, the elution of the photopolymerization initiator from the image can be further suppressed. Therefore, for example, it is particularly suitable as a method for producing an image recorded matter for food packaging.
• the step of irradiating the active energy ray A is preferably a step of fully curing the ink film.
• the main curing is to polymerize substantially all of the polymerizable compound in the ink film to substantially completely cure the ink film.
• the main curing is performed by polymerizing the polymerizable compound in the ink film until the curing rate of the ink film (that is, the polymerization rate of the polymerizable compound determined by high performance liquid chromatography) reaches 90% to 100%. to cure the ink film.
• the irradiation of the active energy ray A for main curing may be referred to as "curing exposure”
• the active energy ray A for main curing may be referred to as "curing exposure light”.
• the illuminance of the active energy ray A as the curing exposure light is preferably 1.0 W/cm 2 or more, more preferably 2.0 W/cm 2 or more, from the viewpoint of further improving the adhesion between the substrate and the image. more preferably 4.0 W/cm 2 or more.
• the upper limit of the illuminance of the active energy ray A as curing exposure light is not particularly limited, and is, for example, 10 W/cm 2 .
• the irradiation energy (i.e., exposure amount) of the active energy ray A as the curing exposure light is preferably 500 mJ/cm2 or more , more preferably 800 mJ/cm2, from the viewpoint of further improving the adhesion between the substrate and the image. It is more preferably 2 or more.
• the upper limit of the exposure amount of the active energy ray A as curing exposure light is not particularly limited, and is, for example, 2000 mJ/cm 2 .
• the irradiation with the active energy ray A is preferably performed in an atmosphere with an oxygen concentration of 0.1% by volume or less. As a result, inhibition of polymerization by oxygen is suppressed, and an image having excellent adhesion to the substrate can be obtained.
• the atmosphere with an oxygen concentration of 0.1% by volume or less is preferably in the presence of an inert gas (eg, nitrogen gas, argon gas, helium gas).
• an inert gas eg, nitrogen gas, argon gas, helium gas.
• the image recording step includes a step of temporarily curing the ink applied on the substrate by irradiation with an active energy ray P having irradiation energy smaller than that of the active energy ray A, and an ink film formed by the temporary curing of the ink is activated. and a step of curing by irradiation with energy rays A to record an image. If the image recording process includes the temporary curing process, the line quality of the image is further improved.
• the temporary curing is performed by removing part of the polymerizable compound in the ink film so that the curing rate of the ink film (that is, the polymerization rate of the polymerizable compound as determined by high performance liquid chromatography; the same shall apply hereinafter) is less than 90%. It is to temporarily harden the ink film by polymerizing to such an extent that it becomes.
• the curing rate of the temporarily cured ink film is more preferably 80% or less, even more preferably 70% or less, and even more preferably 50% or less.
• the curing rate of the temporarily cured ink film is preferably 10% or more, more preferably 20% or more, and even more preferably 30% or more.
• the irradiation of the active energy ray P for temporary curing may be referred to as “pinning exposure”, and the active energy ray P for temporary curing may be referred to as “pinning exposure light”.
• the illuminance of the active energy ray P as the pinning exposure light is preferably 0.10 W/cm 2 to 0.50 W/cm 2 , more preferably 0.20 W/cm 2 to 0.49 W/cm 2 . It is preferably 0.20 W/cm 2 to 0.45 W/cm 2 and more preferably.
• the irradiation energy (that is, exposure amount) of the active energy ray P as the pinning exposure light is preferably 50 mJ/cm 2 to 500 mJ/cm 2 , more preferably 100 mJ/cm 2 to 300 mJ/cm 2 . .
• the image recording method of the present disclosure may further include a step of applying an undercoat liquid to the substrate and temporarily curing the applied undercoat liquid to form an undercoat layer before the ink application step.
• undercoat liquid for example, a preferred combination of ink and undercoat liquid
• undercoat liquid can be carried out by applying known methods such as a coating method, an immersion method, and an inkjet recording method.
• Coating methods include, for example, bar coaters, extrusion coaters, air doctor coaters, blade coaters, rod coaters, knife coaters, squeeze coaters, reverse roll coaters, transfer roll coaters, gravure coaters, kiss roll coaters, cast coaters, spray coaters, It is done using a curtain coater or an extrusion coater.
• the undercoat liquid is preferably applied to the same area as the ink film formed by applying the ink or to a wider area than the ink film, and may be applied so as to cover the entire area where the ink film is formed. preferable.
• the thickness of the undercoat layer formed by applying the undercoat liquid is preferably 0.5 ⁇ m to 6.0 ⁇ m, more preferably 2.0 ⁇ m to 4.0 ⁇ m, from the viewpoint of the flexibility of the recorded image. more preferred.
• Temporary curing of the undercoat liquid can be performed by irradiation with active energy rays, similarly to the temporary curing step of temporarily curing the ink.
• a preferred aspect of the irradiation condition of the active energy ray in this case is the same as a preferred aspect of the irradiation condition of the active energy ray P in the step of pre-curing the ink.
• Examples 1 to 13, Comparative Examples 1 to 5 ⁇ Preparation of metal particle dispersion> A polyethylene terephthalate (PET) film having a thickness of 50 ⁇ m was coated with a 5.0% by mass solution of a coating compound (eg, polymer) shown in Tables 1 to 3 dissolved in ethyl acetate using a gravure coater. The coating liquid was dried to form a polymer layer. A metal film composed of the metals shown in Tables 1 to 3 was formed on the polymer layer by a vacuum deposition method to obtain a laminate composed of the PET film, the polymer layer and the metal film. The laminate was immersed in propylene glycol monomethyl ether (PGME) to dissolve the polymer layer.
• PGME propylene glycol monomethyl ether
• Micronization treatment and dispersion treatment were performed using an ultrasonic disperser to obtain a metal particle dispersion liquid containing metal particles having at least a portion of the surface coated with a polymer.
• the obtained dispersion was filtered through a SUS mesh filter with an opening of 5 ⁇ m, and if necessary, the solvent was removed by an evaporator or the like or added to obtain a metal particle dispersion having a predetermined concentration.
• a metal film was formed on the film, and then the metal film was peeled off using a doctor blade in PGME, followed by miniaturization treatment and dispersion treatment, and metal particles not coated with the polymer. got Also, in Comparative Example 4, fatty acid triglyceride, which is a low-molecular-weight compound, was used as the coating compound instead of the polymer.
• ⁇ Ink preparation> The metal particle dispersion and other components are mixed so that the contents of the metal particles, the polymerizable compound, the photopolymerization initiator, the polymerization inhibitor, the organic solvent, and the surfactant are the values shown in Tables 1 to 3. was mixed to prepare an ink.
• BYK-378 Silicone surfactant (manufactured by BYK) - BYK-UV3576: a silicone-based surfactant having an acryloyl group (manufactured by BYK)
• the calculation method is as follows.
• the content of metal particles in the ink was adjusted to 0.5% by mass.
• the polymerizable compound having the highest content in the ink was selected.
• a liquid in which the content of metal particles in the ink was adjusted to 0.5% by mass was cured by irradiation with an active energy ray to obtain an ink film with a thickness of 12 ⁇ m.
• the cross section of the ink film was observed with a scanning electron microscope (SEM) (for example, Nova200 type FIB-SEM manufactured by Thermo Fisher Scientific) at a magnification of 50000 times.
• SEM scanning electron microscope
• the number X of metal particles present in the entire cross section of the ink film and the number Y of metal particles present in a region within 100 nm from the surface of the ink film toward the inside of the ink film were measured.
• a ratio of the number Y to the number X was calculated.
• the calculated value was defined as the existence ratio of the metal particles on the ink film surface, and the ink film surface was divided into the following categories.
• the classification is shown in Table 1.
• C The proportion of metal particles present on the ink film surface is less than 50%.
• ⁇ Image recording method> The above ink was introduced into the white throttle of a multi-pass system (that is, shuttle scan system) inkjet printer (product name: "Acuity LED 1600R", manufactured by Fujifilm Corporation). Viewful PET (thickness 188 ⁇ m) was prepared as a base material. Ink was discharged onto the base material in the form of a solid image with a halftone dot rate of 100% and in the form of a 2-point line image by a multipass method. The ink application conditions were 1200 dpi ⁇ 1200 dpi (dots per inch), 48 passes, and bi-directional printing.
• pinning exposure light exposure light for temporary curing
• active energy ray P and active energy ray A Curing exposure light exposure light for main curing
• the time from the ink landing on the base material to the irradiation of the pinning exposure light is 0.1 second
• the time from the ink landing on the base material to the irradiation of the curing exposure light is It was 2.0 seconds.
• the pinning exposure light is ultraviolet rays with a peak wavelength of 385 nm
• the curing exposure light is ultraviolet rays with a peak wavelength of 385 nm.
• the irradiation energy of the pinning exposure light was set at 200 mJ/cm 2 and the irradiation energy of the curing exposure light was set at 1000 mJ/cm 2 .
• an external metal halide light source was used as the curing light source.
• the ink on the substrate is irradiated with the curing exposure light under a nitrogen purge atmosphere (specifically, an atmosphere with an oxygen concentration of 0.1% by volume or less and a nitrogen concentration of 99.9% by volume or more). went. Under the above conditions, the ink applied on the substrate was subjected to temporary curing and final curing in this order to record an image (a solid image and a line image) to obtain an image recorded matter.
• the evaluation method is as follows.
• the 20° glossiness of the solid image in the image record was measured. The higher the 20° glossiness, the better the metallic glossiness. Evaluation criteria are as follows. A: The 20° glossiness is 500 or more. B: The 20° glossiness is 200 or more and less than 500. C: The 20° glossiness is 100 or more and less than 200. D: The 20° glossiness is less than 100.
• Evaluation criteria are as follows. A: Raggedness of the line image is less than 2.0. B: The line image has a raggedness of 2.0 or more and less than 4.0. C: The line image has a raggedness of 4.0 or more and less than 6.0. D: The line image has a raggedness of 6.0 or more and less than 8.0. E: The line image has a raggedness of 8.0 or more.
• Rate of increase (%) ⁇ (Viscosity after test - Viscosity before test) / Viscosity before test ⁇ x 100
• the "percentage of metal particles on the ink film surface” refers to the cross section of the ink film obtained by curing the liquid in which the content of metal particles in the ink is adjusted to 0.5% by mass. , means the proportion of metal particles present in a region within 100 nm from the surface of the ink film toward the inside of the ink film.
• the inks of Examples 1 to 13 contain metal particles, a polymerizable compound, and a polymerization inhibitor.
• a liquid in which the content of metal particles in the energy ray-curable inkjet ink is adjusted to 0.5% by mass from the surface of the ink film to the inside of the ink film 50% by mass or more of the total mass of the metal particles exists in the region within 100 nm, and the surface tension is 30 mN/m or more.
• undercoat liquid was prepared by mixing the following components.
• ⁇ NVC 20% by mass ⁇ CTFA ... 73.4% by mass ⁇ Omnirad 819 ... 2.8% by mass ⁇ Omnirad TPO-H ... 2.8% by mass
• ITX isopropyl thioxanthone (product name “ITX”, manufactured by Lambson) ... 0.5% by mass
• FLORSTAB UV12 manufactured by Kromachem
• ⁇ Image recording method> Using the prepared undercoat liquid and the ink prepared in Example 1, an image was recorded.
• the undercoat liquid was introduced into the white throttle of a multi-pass type (that is, shuttle scan type) ink jet printer (product name: "Acuity LED 1600R” manufactured by Fujifilm Corporation), and the ink was introduced into the clear throttle.
• a printing paper (trade name “Araver”) was prepared as a base material.
• the undercoat liquid was discharged onto the base material in the form of a solid image with a halftone dot rate of 100% by a multipass method.
• the conditions for applying the undercoat liquid were 1200 dpi ⁇ 1200 dpi (dots per inch), 48 passes, and bi-directional printing.
• the undercoat liquid applied to the substrate was irradiated with curing exposure light (exposure light for main curing). The time from the landing of the undercoat liquid on the substrate to the irradiation of the curing exposure light was 0.1 second.
• ink was ejected in the form of a solid image with a halftone dot rate of 100% and in the form of a 2-point line image by a multipass method.
• the ink application conditions were 1200 dpi ⁇ 1200 dpi (dots per inch), 48 passes, and bi-directional printing.
• the ink applied to the base material is exposed to pinning exposure light as active energy ray P (exposure light for temporary curing) and curing exposure light as active energy ray A (exposure light for main curing) and , were irradiated in this order.
• the time from the ink landing on the base material to the irradiation of the pinning exposure light is 0.1 second, and the time from the ink landing on the base material to the irradiation of the curing exposure light is It was 2.0 seconds.
• the pinning exposure light is ultraviolet rays with a peak wavelength of 385 nm
• the curing exposure light is ultraviolet rays with a peak wavelength of 385 nm.
• the irradiation energy of the pinning exposure light was set at 200 mJ/cm 2 and the irradiation energy of the curing exposure light was set at 1000 mJ/cm 2 .
• the ink on the substrate is irradiated with the curing exposure light under a nitrogen purge atmosphere (specifically, an atmosphere with an oxygen concentration of 0.1% by volume or less and a nitrogen concentration of 99.9% by volume or more). went. An image record was obtained under the above conditions.
• Example 102 Using the undercoat liquid prepared in Example 101 and the ink prepared in Example 1, an image was recorded.
• the undercoat liquid was introduced into the white throttle of a multi-pass type (that is, shuttle scan type) ink jet printer (product name: "Acuity LED 1600R” manufactured by Fujifilm Corporation), and the ink was introduced into the clear throttle.
• a printing paper (trade name “Kasane”) was prepared as a base material.
• the undercoat liquid was discharged onto the base material in the form of a solid image with a halftone dot rate of 100% by a multipass method.
• the conditions for applying the undercoat liquid were 1200 dpi ⁇ 1200 dpi (dots per inch), 48 passes, and bi-directional printing.
• the undercoat liquid applied to the substrate was irradiated with pinning exposure light (exposure light for temporary curing) and curing exposure light (exposure light for main curing).
• the time from the landing of the undercoat liquid on the base material to the irradiation of the pinning exposure light is 0.1 second, and the time from the landing of the undercoat liquid on the base material to the irradiation of the curing exposure light.
• the time was 2.0 seconds.
• the same method as in Example 101 was performed for the step of ejecting ink onto the substrate to which the undercoat liquid was applied and exposing the substrate. An image record was obtained under the above conditions.
• Example 103 Using the undercoat liquid prepared in Example 101 and the ink prepared in Example 1, an image was recorded.
• the undercoat liquid was introduced into the white throttle of a multi-pass type (that is, shuttle scan type) ink jet printer (product name: "Acuity LED 1600R” manufactured by Fujifilm Corporation), and the ink was introduced into the clear throttle.
• Synthetic leather (trade name “Cappuccino”) was prepared as a base material.
• the undercoat liquid was discharged onto the base material in the form of a solid image with a halftone dot rate of 100% by a multipass method.
• the conditions for applying the undercoat liquid were 1200 dpi ⁇ 1200 dpi (dots per inch), 48 passes, and bi-directional printing.
• the undercoat liquid applied to the substrate was irradiated with pinning exposure light (exposure light for temporary curing).
• the time from the landing of the undercoat liquid on the substrate to the irradiation of the pinning exposure light is 0.1 second.
• the same method as in Example 101 was performed for the step of ejecting ink onto the substrate to which the undercoat liquid was applied and exposing the substrate. An image record was obtained under the above conditions.
• Example 1 Using the obtained image record, the metallic luster and image quality were evaluated in the same manner as in Example 1. All of Examples 101 to 103 were evaluated as A for metallic luster and image quality.

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• 2022
  • 2022-07-13 WO PCT/JP2022/027607 patent/WO2023037761A1/ja not_active Ceased
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