Ink set for inkjet and method for producing printed matter using said ink set

Abstract

The present disclosure addresses the problem of providing a new ink set for inkjet having excellent high-speed transferability and being capable of enhancing tensile durability of obtained printed matter.　An ink set for inkjet according to the present disclosure is characterized by comprising a white ink and an adhesive ink, and is characterized in that: the white ink contains water, an organic solvent, a urethane resin, and a white pigment; the adhesive ink contains water, an organic solvent, and an acrylic resin; and the static surface tension of the adhesive ink is less than the static surface tension of the white ink.

Description

Inkjet ink set and method for producing printed matter using said ink set

[0001] The present disclosure relates to an inkjet ink set, a method for producing a transfer medium using the ink set, and a method for producing a printed matter using the transfer medium.

[0002] A method is known in which an image formed by printing an ink containing a coloring material on a transfer substrate is transferred onto a transfer-receiving medium using an adhesive ink. For example, Patent Document 1 discloses a method in which an image is formed by discharging an aqueous ink onto a releasable support by an inkjet method, and an aqueous adhesive liquid containing two types of resins having specific glass transition temperatures by an inkjet method so as to at least partially overlap the image, thereby preparing a transfer sheet, attaching the transfer sheet to the surface of a transfer-receiving object, and peeling the releasable support from the transfer sheet, thereby transferring the image onto the surface of the transfer-receiving object, and describes that the transferability and dry rub fastness of the resulting printed matter are excellent.

[0003] JP 2024-17827 A

[0004]

[0003] In order to improve productivity, transfer printing is required to exhibit good transferability in a shorter transfer time. Furthermore, durability of the printed matter transferred to the transfer medium is also required. For example, when the transfer medium is a fabric, durability against expansion and contraction of the resulting printed matter (hereinafter referred to as tensile durability) is required. However, Patent Document 1 does not consider at all how to achieve both transferability and tensile durability.

[0005] Therefore, an object of the present disclosure is to provide a new inkjet ink set and transfer medium that has excellent transferability even in a short transfer time (i.e., excellent high-speed transferability) and can improve the tensile durability of the resulting printed matter.

[0006] As a result of extensive research into solving the above problems, the present inventors discovered that by using an inkjet ink set containing a specific white ink containing a urethane resin and a specific adhesive ink containing an acrylic resin, it is possible to achieve excellent high-speed transferability and improve the tensile durability of the resulting printed matter, and have thereby completed the present invention.

[0007] That is, the contents of the present disclosure are as follows. [1] An inkjet ink set comprising a white ink (A) and an adhesive ink (B), wherein the white ink (A) comprises water (a1), an organic solvent (a2), a urethane resin (a3), and a white pigment (a4), and the adhesive ink (B) comprises water (b1), an organic solvent (b2), and an acrylic resin (b3), and wherein the static surface tension of the adhesive ink (B) is lower than the static surface tension of the white ink (A). [2] The ink set according to [1], wherein the urethane resin (a3) ​​is contained in the white ink (A) as emulsion particles, and the acrylic resin (b3) is contained in the adhesive ink (B) as emulsion particles. [3] The ink set according to [1] or [2], wherein the acrylic resin (b3) has a glass transition temperature of 30°C or lower. [4] The ink set according to any one of [1] to [3], wherein the acrylic resin (b3) has a weight-average molecular weight of 10,000 to 800,000. [5] The ink set according to any one of [1] to [4], wherein the ink set is used for manufacturing a transfer medium for transfer printing. [6] The ink set according to any one of [1] to [4], wherein the ink set is used for manufacturing a transfer medium for transfer printing on fabric. [7] The ink set according to any one of [1] to [6], further comprising one or more color inks (C) containing a colorant (c1) exhibiting a hue other than white. [8] The ink set according to [7], wherein the color ink (C) is at least one ink selected from the group consisting of a cyan ink, a magenta ink, a yellow ink, and a black ink. [9] The ink set according to any one of [1] to [8], wherein the organic solvent (a2) comprises an organic solvent (2-1) having a normal boiling point of 250°C or less, and the content of the organic solvent (2-1) in the white ink (A) is 12% by mass or more.

[10] The ink set according to any one of [1] to [9], wherein the average normal boiling point of all solvents constituting the organic solvent (a2) is equal to or lower than the average normal boiling point of all solvents constituting the organic solvent (b2).

[11] A method for producing a transfer medium using the ink set according to any one of [1] to

[10] , comprising the steps of inkjet printing the white ink (A) onto a transfer substrate or onto a surface layer formed on the transfer substrate so as to be peelable from the transfer substrate, and inkjet printing the adhesive ink (B) onto the surface printed with the white ink (A).

[12] A method for producing a printed matter, in which transfer printing is performed by bringing the printed surface of the transfer medium obtained by the production method according to

[11] into contact with a medium to be transferred.

[0008] According to the present disclosure, it is possible to provide a new inkjet ink set that is excellent in high-speed transferability and can improve the tensile durability of the resulting printed matter.

[0009] 1 is a schematic cross-sectional view showing an example of a layered structure of a transfer medium according to the present disclosure. 2 is a schematic cross-sectional view showing an example of a layered structure of a transfer medium and a transfer-receiving medium during transfer printing according to the present disclosure.

[0010] An embodiment of the present disclosure will be described below, but the contents of the present disclosure are not limited thereto. In this specification, unless otherwise specified, "A to B" representing a numerical range means "greater than or equal to A and less than or equal to B." Furthermore, "(meth)acrylic acid" means acrylic acid or methacrylic acid, and "(meth)acrylate" means acrylate or methacrylate. The same applies to terms such as "(meth)acryloxy" and "(meth)acryloyl." Furthermore, a "structural unit derived from" corresponds to a structure in which the carbon-carbon double bond in each monomer component is replaced with a carbon-carbon single bond and two bonds bonded to the respective carbons.

[0011] 1. White Ink (A) The white ink (A) contains water (a1), an organic solvent (a2), a urethane resin (a3), and a white pigment (a4).

[0012] 1-1. The solvent white ink (A) contains water (a1) and an organic solvent (a2) as solvents. These solvents act as diluents to adjust the viscosity of the white ink (A). The total content of water (a1) and organic solvent (a2) in the white ink (A) can be set according to the desired viscosity of the white ink (A) and is not particularly limited, but is, for example, 40 to 90% by mass, preferably 50 to 88% by mass, and more preferably 55 to 85% by mass.

[0013] The content of the organic solvent (a2) in the white ink (A) is preferably 5 to 50% by mass, more preferably 12 to 40% by mass, even more preferably 14 to 35% by mass, and particularly preferably 16 to 30% by mass. The content of the organic solvent (a2) is preferably 10 to 60 parts by mass, more preferably 20 to 55 parts by mass, and even more preferably 30 to 50 parts by mass, per 100 parts by mass of water (a1).

[0014] The organic solvent (a2) is preferably a water-soluble organic solvent. In this specification, "water-soluble organic solvent" refers to an organic solvent that dissolves in water at a concentration of 0.01% by mass or more at 25°C and 1 atmosphere. By including a water-soluble organic solvent in the white ink (A), it is possible to improve the moisture retention and compatibility with the urethane resin (a3). The water-soluble organic solvent may be used alone or in combination of two or more.

[0015] Examples of the water-soluble organic solvent include lower alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, and tert-butyl alcohol (preferably C 1-4alcohol); glycols such as propylene glycol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, ethylene glycol, diethylene glycol, triethylene glycol, and tetraethylene glycol; glycerin; monoalkyl ethers of monoalkylene glycols (preferably mono-C), such as monoethylene glycol monomethyl ether, monoethylene glycol monoethyl ether, monoethylene glycol monopropyl ether, monoethylene glycol monoisopropyl ether, monoethylene glycol monobutyl ether, monoethylene glycol monoisobutyl ether, monopropylene glycol monomethyl ether, monopropylene glycol monoethyl ether, monopropylene glycol monopropyl ether, monopropylene glycol monoisopropyl ether, monopropylene glycol monobutyl ether, and monopropylene glycol monoisobutyl ether; 2-3 Alkylene glycol mono C 1-4 alkyl ethers); monoalkyl ethers of dialkylene glycols such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monoisobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoisopropyl ether, dipropylene glycol monobutyl ether, and dipropylene glycol monoisobutyl ether (preferably diC 2-3 Alkylene glycol mono C 1-4alkyl ethers); monoalkyl ethers of polyalkylene glycols such as monomethyl ether of polyethylene glycol, monoethyl ether of polyethylene glycol, monopropyl ether of polyethylene glycol, monoisopropyl ether of polyethylene glycol, monobutyl ether of polyethylene glycol, monoisobutyl ether of polyethylene glycol, monomethyl ether of polypropylene glycol, monoethyl ether of polypropylene glycol, monopropyl ether of polypropylene glycol, monoisopropyl ether of polypropylene glycol, monobutyl ether of polypropylene glycol, and monoisobutyl ether of polypropylene glycol (preferably polyC 2-3 Alkylene glycol mono C 1-4 Examples of the alkylene oxide include: alkyl ethers; heterocycles such as 2-pyrrolidone and N-methyl-2-pyrrolidone; and ketones such as acetone and methyl ethyl ketone. The number of moles of alkylene oxide added in the monoalkyl ether of the polyalkylene glycol is preferably 2 to 10, and more preferably 2 to 4.

[0016] The organic solvent (a2) may be used alone or in combination of two or more kinds.

[0017] From the viewpoint of improving drying properties, the organic solvent (a2) preferably contains an organic solvent (hereinafter, sometimes referred to as organic solvent (2-1)) having a normal boiling point (hereinafter, when simply referred to as boiling point, this refers to the normal boiling point) of 250°C or less, and the organic solvent (2-1) is more preferably a water-soluble organic solvent. The normal boiling point refers to the boiling point at an external pressure of 1 bar.

[0018] The content of the organic solvent (2-1) in the white ink (A) is preferably 12% by mass or more, more preferably 12 to 40% by mass, even more preferably 14 to 35% by mass, and particularly preferably 16 to 30% by mass. By adjusting the content of the organic solvent (2-1) within the above range, the balance between drying properties and moisture retention can be improved. Furthermore, from the viewpoint of further improving drying properties, the content of the organic solvent having a boiling point of above 250°C in the white ink (A) may be, for example, 0 to 25% by mass, but is preferably less than 5% by mass, more preferably 2% by mass or less, even more preferably 1% by mass or less, and particularly preferably 0% by mass.

[0019] From the viewpoint of further enhancing the moisture retention, the lower limit of the boiling point of the organic solvent (2-1) is preferably 150° C. or higher, more preferably 180° C. or higher. That is, the boiling point of the organic solvent (2-1) is preferably 150 to 250° C., more preferably 180 to 250° C.

[0020] Among the organic solvents (2-1), at least one selected from glycols having a boiling point of 250° C. or less, such as propylene glycol and diethylene glycol, and organic solvents (2-2) described below having a boiling point of 250° C. or less are preferred.

[0021] The content of the organic solvent (2-1) is, for example, 1 to 50 parts by mass, preferably 10 to 50 parts by mass, and more preferably 15 to 40 parts by mass, per 100 parts by mass of water (a1).

[0022] From the viewpoint of further enhancing compatibility with the resin, it is also preferable that the organic solvent (a2) contains a water-soluble organic solvent having a hydrophobic group (e.g., an alkyl group) and a hydroxyl group (hereinafter, sometimes referred to as organic solvent (2-2)). The organic solvent (2-2) may be an organic solvent included in the organic solvent (2-1) (i.e., a boiling point of 250°C or less) or may have a boiling point of more than 250°C, but is more preferably an organic solvent included in the organic solvent (2-1).

[0023] The organic solvent (2-2) is preferably a monoalkyl ether of a dialkylene glycol and / or a monoalkyl ether of a polyalkylene glycol (number of moles of alkylene oxide added = 2 to 10, preferably 2 to 4), and diC 2-3 Alkylene glycol mono C 1-4 Alkyl ether and / or poly C 2-3 Alkylene glycol mono C 1-4 Alkyl ethers (number of moles of alkylene oxide added = 2 to 10, preferably 2 to 4) are more preferred, and at least one selected from the group consisting of diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monoisobutyl ether, and tripropylene glycol monomethyl ether is even more preferred.

[0024] The content of the organic solvent (2-2) is preferably 1 to 15 parts by mass, more preferably 2 to 8 parts by mass, per 100 parts by mass of water (a1).

[0025] The average normal boiling point of all solvents constituting the organic solvent (a2) is, for example, 120 to 300°C. In particular, from the viewpoint of further improving tensile durability, the average normal boiling point is preferably 250°C or lower, more preferably 150 to 250°C, even more preferably 170 to 250°C, and particularly preferably 180 to 250°C. In this specification, the "average normal boiling point of all solvents constituting the organic solvent" refers to the weighted average of the normal boiling points of each organic solvent when the total amount of the organic solvents is taken as 100% by mass. That is, when the organic solvent (a2) consists of only one solvent, the normal boiling point of that solvent is the average normal boiling point. When the organic solvent (a2) contains multiple solvents, the average normal boiling point refers to the weighted average of the normal boiling points of each solvent based on the mass proportion of each solvent in the total amount of the organic solvent (a2).

[0026] 1-2. Urethane Resin (a3) ​​The urethane resin (a3) ​​is not particularly limited as long as it is a resin having a urethane skeleton in the main chain, and for example, a reaction product of polyisocyanate and polyol can be used, and specifically, known urethane resins such as polyester-based urethane resins, polyether-based urethane resins, polycarbonate-based urethane resins, etc. The urethane resin (a3) ​​may be used alone or in combination of two or more types.

[0027] The urethane resin (a3) ​​is preferably a resin in which the total amount of polyisocyanate and polyol is 30% by mass or more, more preferably 50% by mass or more, and even more preferably 70% by mass or more, of the total amount of monomers constituting the resin.

[0028] The polyisocyanate is a compound containing at least two isocyanate groups in the molecule. Examples of the polyisocyanate include chain aliphatic isocyanates such as tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, dodecamethylene diisocyanate, trimethylhexamethylene diisocyanate, and lysine diisocyanate; aliphatic isocyanates having a cyclic structure such as 1,3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, and 3,3'-dimethyl-4,4'-dicyclohexylmethane diisocyanate; 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m- Examples of the isocyanate include aromatic isocyanates such as phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, 3,3'-dimethoxy-4,4'-biphenylene diisocyanate, 3,3'-dichloro-4,4'-biphenylene diisocyanate, 1,5-naphthalene diisocyanate, 1,5-tetrahydronaphthalene diisocyanate, xylylene diisocyanate, and tetramethylxylylene diisocyanate; modified products thereof such as isocyanurates and biuret products; and the like. Also usable are so-called blocked isocyanates in which the isocyanate groups in these polyisocyanates are inactivated by reacting them with a masking agent having active hydrogen. These polyisocyanates may be used alone or in combination of two or more.

[0029] Examples of the polyol include polyester polyol, polyether polyol, polycarbonate polyol, etc. The polyester-based urethane resin refers to a resin in which the main component of the polyol constituting the urethane resin (a3) ​​is polyester polyol, the polyether-based urethane resin refers to a resin in which the main component of the polyol constituting the urethane resin (a3) ​​is polyether polyol, and the polycarbonate-based urethane resin refers to a resin in which the main component of the polyol constituting the urethane resin (a3) ​​is polycarbonate polyol. The main component refers to the component that is most abundant among the polyols constituting the urethane resin (a3), and specifically refers to a component that is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more, of 100% by mass of the polyol constituting the urethane resin (a3). Examples of polyester polyols include polyester diols such as polyethylene adipate, polybutylene adipate, polyneopentyl adipate, poly-3-methylpentyl adipate, polyethylene / butylene adipate, polyneopentyl / hexyl adipate, polyethylene succinate, polybutylene succinate, polyethylene sebacate, and polybutylene sebacate. Examples of polyether polyols include polyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. Examples of polycarbonate polyols include reaction products of diols (preferably (poly)alkylene glycols) such as 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol with phosgene, dialkyl carbonates such as dimethyl carbonate, or cyclic carbonates such as ethylene carbonate. These polyols may be used alone or in combination of two or more.

[0030] The urethane resin (a3) ​​may be an acrylic urethane resin. Examples of the acrylic urethane resin include copolymers of acrylic resin and urethane resin. More specifically, examples include copolymers in which a urethane prepolymer and a (meth)acrylic monomer are polymerized to introduce a structural unit derived from the (meth)acrylic monomer or a side chain of a poly(meth)acrylic structure into the urethane skeleton. Examples of urethane prepolymers include those synthesized using the above-mentioned polyisocyanates and polyols. Examples of (meth)acrylic monomers include monomers having a (meth)acryloyl group. Specific examples include, but are not limited to, (meth)acrylic acid alkyl esters, (meth)acrylic acid, and hydroxyalkyl (meth)acrylates, which will be described below as monomers constituting the acrylic resin (b3). The acrylic urethane resin included in the urethane resin (a3) ​​is preferably a resin in which the total amount of polyisocyanates and polyols is 50% by mass or more of the total amount of monomers constituting the resin.

[0031] The urethane resin (a3) ​​preferably has a glass transition temperature (Tg) of −50 to 10° C. When the urethane resin (a3) ​​has a Tg of not less than the above-mentioned lower limit, the tensile durability of the resulting printed matter is further improved, and when the urethane resin (a3) ​​has a Tg of not more than the above-mentioned upper limit, the texture of the resulting printed matter can be improved.

[0032] When the urethane resin (a3) ​​is composed of two or more resins or when the urethane resin (a3) ​​has a core-shell structure, multiple Tg values ​​may be observed. In such cases, it is preferable that at least one Tg value satisfies the above range, and it is more preferable that all Tg values ​​satisfy the above range.

[0033] The urethane resin (a3) ​​may be a synthesized product or a commercially available product. For example, the urethane resin can be synthesized by reacting a polyisocyanate with a polyol, and the reaction between the polyisocyanate and the polyol can be carried out by a known method.

[0034] When the urethane resin (a3) ​​is contained in the white ink (A), it is preferably added as an emulsion, that is, the urethane resin (a3) ​​is preferably contained in the white ink (A) as emulsion particles.

[0035] The shape of the emulsion particles is not particularly limited, but is usually spherical. The shape can be measured using a transmission electron microscope or a scanning electron microscope.

[0036] The emulsion particles may be resin particles having a single-phase structure or may be resin particles having a multi-phase structure. Resin particles having a single-phase structure refer to resin particles having a uniform composition throughout the particle. As long as the composition of the single-phase resin particles is uniform throughout the particle, properties other than the composition, such as weight average molecular weight and Tg, may be the same or different depending on the location. Resin particles having a multi-phase structure refer to particles composed of two or more phases with different compositions. Resin particles having a multi-phase structure are preferably resin particles having a multi-layer structure in which the polymers constituting each layer have different compositions, and more preferably resin particles having a core-shell structure consisting of a core portion and a shell portion with different compositions.

[0037] The emulsion particles may contain one or more types of resin particles having a single-phase structure, or may contain one or more types of resin particles having a multi-phase structure (preferably a core-shell structure), or may contain resin particles having a single-phase structure and resin particles having a multi-phase structure (preferably a core-shell structure).

[0038] The average particle size of the emulsion particles is preferably 5 to 500 nm, more preferably 10 to 400 nm, and even more preferably 10 to 350 nm. By adjusting the average particle size of the emulsion particles to fall within the above range, it becomes easier to incorporate the emulsion particles at a high concentration while maintaining the viscosity of the white ink (A) within an appropriate range. The average particle size of the emulsion particles may be determined by the cumulant average particle size measured by dynamic light scattering, as shown in the examples below.

[0039] The content of the urethane resin (a3) ​​in the white ink (A) is, for example, 3 to 50% by mass, preferably 5 to 30% by mass, and more preferably 7 to 20% by mass. By adjusting the resin content within this range, the viscosity of the white ink (A) can be maintained within an appropriate range while further enhancing the effects of the ink set of the present disclosure. Furthermore, the content of the urethane resin (a3) ​​is preferably 10 to 80% by mass, more preferably 30 to 65% by mass, and even more preferably 40 to 55% by mass, based on 100% by mass of the solids content of the white ink (A).

[0040] The white ink (A) may contain a resin other than the urethane resin (a3), but preferably does not contain one. Examples of resins other than the urethane resin (a3) ​​include vinyl resins, polyester resins, olefin resins, acrylic resins, fluororesins, silicone resins, epoxy resins, phenoxy resins, phenolic resins, and xylene resins. The content of the urethane resin (a3) ​​in 100% by mass of the resins contained in the white ink (A) is preferably 60% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, still more preferably 95% by mass or more, and particularly preferably 100% by mass.

[0041] 1-3. White Pigment (a4) The white pigment (a4) is not particularly limited, and known white pigments can be used, including, for example, titanium dioxide, antimony trioxide, zinc oxide such as zinc white, lithopone, white lead, calcium carbonate, magnesium hydroxide, aluminum hydroxide, barium sulfate, magnesium carbonate, clay, talc, and aluminum silicate. These may be used alone or in combination of two or more. Among these, titanium dioxide is preferred from the viewpoint of having a high refractive index and excellent hiding power, and titanium dioxide having a rutile crystal structure is more preferred.

[0042] From the viewpoint of hiding power, the average particle size of the white pigment (a4) is preferably 50 to 1,000 nm, more preferably 100 to 500 nm, even more preferably 150 to 450 nm, and particularly preferably 200 to 400 nm. The average particle size of the white pigment (a4) may be a cumulant average particle size measured by dynamic light scattering, as shown in the examples below.

[0043] It is preferred that the white pigment (a4) be stabilized in dispersion by a dispersant in the white ink (A). For this reason, in the production of the white ink (A), it is preferred to mix the white pigment (a4), the dispersant, and a solvent (water (a1) and / or organic solvent (a2)), and then perform a dispersion treatment using a bead mill or the like to prepare a pigment dispersion in which the white pigment (a4) is dispersed in the solvent, and then mix this with other components such as the urethane resin (a3) ​​to produce the white ink (A).

[0044] Examples of the dispersant include poly(meth)acrylic acid (salts) such as poly(meth)acrylic acid and poly(meth)acrylate salts; copolymers of (meth)acrylic acid (salts) with one or more monomer components other than (meth)acrylic acid (salts), such as (meth)acrylic acid alkyl esters, (meth)acrylamide, styrene, maleic acid, maleic anhydride, maleic acid esters, and vinyl acetate; polyvinyl alcohol; and polyvinylpyrrolidone.

[0045] The content of the white pigment (a4) in the white ink (A) is preferably 1 to 50% by mass, more preferably 5 to 30% by mass, and even more preferably 7 to 20% by mass. The content of the white pigment (a4) is preferably 10 to 80% by mass, more preferably 30 to 65% by mass, and even more preferably 40 to 55% by mass, based on 100% by mass of the solids content of the white ink (A).

[0046] 1-4. Surfactant (a5) The white ink (A) may further contain a surfactant (hereinafter, surfactant (a5)). By using the surfactant (a5), it becomes possible to adjust the static surface tension to a level suitable for inkjet ejection.

[0047] As the surfactant (a5), for example, an acetylene glycol surfactant, a silicone surfactant, a fluorine surfactant, or the like is preferably used. As the acetylene glycol surfactant, commercially available products may be used, and specific examples thereof include the Surfynol series (manufactured by Evonik), the Olfine series (manufactured by Nissin Chemical Industry Co., Ltd.), and the Acetylenol series (manufactured by Kawaken Fine Chemicals Co., Ltd.). As the silicone surfactant, a polyether-modified silicone surfactant is preferably used. As the silicone surfactant, commercially available products may be used, and specific examples thereof include the Silface series (manufactured by Nissin Chemical Industry Co., Ltd.), the KF series (manufactured by Shin-Etsu Chemical Co., Ltd.), and BYK-345, 347, 348, 349, 3450, 3451, 3455, and 3480 (all manufactured by BYK). Examples of the fluorine-based surfactant include perfluoroalkyl sulfonic acid compounds, perfluoroalkyl carboxylic acid compounds, perfluoroalkyl phosphate ester compounds, perfluoroalkyl ethylene oxide adducts, polyoxyalkylene ether polymer compounds having perfluoroalkyl ether groups on the side chains, etc. Commercially available products may be used as the fluorine-based surfactant, and specific examples include the Surflon series (manufactured by AGC Sei Chemical Co., Ltd.) and the Megafac F series (manufactured by DIC Corporation).

[0048] The surfactant (a5) may be used alone or in combination of two or more kinds.

[0049] The surfactant (a5) is preferably an acetylene glycol surfactant and / or a silicone surfactant, more preferably a silicone surfactant, and even more preferably a polyether-modified silicone surfactant.

[0050] The content of the surfactant (a5) is not particularly limited, but from the viewpoint of ejection stability, it is preferably from 0.01 to 2.0 mass%, more preferably from 0.05 to 1.5 mass%, and even more preferably from 0.1 to 1.0 mass%, relative to 100 mass% of the white ink (A).

[0051] 1-5. Other Additives The white ink (A) may contain other components in addition to the components described above, provided that the objectives of the present disclosure are not impaired. For example, the white ink (A) may contain appropriate amounts of additives such as crosslinkers, leveling agents, UV absorbers, UV stabilizers, thickeners, humectants, plasticizers, stabilizers, defoamers, pigments other than white pigments, dyes, antioxidants, crosslinking accelerators, pH adjusters, and preservatives. When the other components are added, their content is not particularly limited, but is, for example, 10.0% by mass or less, preferably 5.0% by mass or less, and more preferably 3.0% by mass or less or 1.0% by mass or less, relative to 100% by mass of the white ink (A). To achieve the desired effect, the content is preferably 0.01% by mass or more, and more preferably 0.05% by mass or more. That is, the content of the other components may be 0.01 to 10.0% by mass, 0.01 to 5.0% by mass, 0.05 to 3.0% by mass, or 0.05 to 1.0% by mass relative to 100% by mass of the white ink (A).

[0052] 1-6. Physical Properties of White Ink (A) The pH of the white ink (A) at 25°C is preferably 7 to 10, and more preferably 7 to 9. By adjusting the pH of the white ink (A) to fall within the above range, the dispersion stability of the ink can be improved.

[0053] The static surface tension of the white ink (A) at 25°C is preferably 22 to 35 mN / m, more preferably 24 to 30 mN / m, and even more preferably 25 to 28 mN / m. By adjusting the static surface tension of the white ink (A) to be equal to or greater than the above-mentioned lower limit, the amount of leveling agent can be reduced, and by adjusting it to be equal to or less than the above-mentioned upper limit, uneven drying of the ink can be reduced. The static surface tension can be measured by the method described in the examples below.

[0054] The viscosity of the white ink (A) at 25°C is preferably 2 to 10 mPa·s, and more preferably 3 to 7 mPa·s. Adjusting the viscosity of the white ink (A) to be equal to or greater than the above-mentioned lower limit can reduce ink drying unevenness, while adjusting the viscosity to be equal to or less than the above-mentioned upper limit can impart inkjet ejection stability. The viscosity can be measured using an E-type viscometer at a measurement temperature of 25°C.

[0055] 2. Adhesive Ink (B) The adhesive ink (B) contains water (b1), an organic solvent (b2), and an acrylic resin (b3).

[0056] 2-1. The solvent-based adhesive ink (B) contains water (b1) and an organic solvent (b2) as solvents. These solvents act as diluents to adjust the viscosity of the adhesive ink (B). The total content of water (b1) and organic solvent (b2) in the adhesive ink (B) can be set according to the desired viscosity of the adhesive ink (B) and is not particularly limited, but is, for example, 40 to 95% by mass, preferably 50 to 90% by mass, and more preferably 65 to 88% by mass.

[0057] The content of the organic solvent (b2) in the adhesive ink (B) is preferably 5 to 50% by mass, more preferably 10 to 40% by mass, even more preferably 14 to 35% by mass, and particularly preferably 16 to 30% by mass. The content of the organic solvent (b2) is preferably 10 to 60 parts by mass, more preferably 20 to 50 parts by mass, and even more preferably 30 to 45 parts by mass, per 100 parts by mass of water (b1).

[0058] As the organic solvent (b2), the solvents described as the organic solvent (a2) can be used, and the preferred embodiments thereof are also the same. The content of the organic solvent (2-1) is preferably 10 to 50 parts by mass, and more preferably 15 to 40 parts by mass, per 100 parts by mass of the water (b1). The content of the organic solvent (2-2) is preferably 1 to 15 parts by mass, and more preferably 2 to 8 parts by mass, per 100 parts by mass of the water (b1).

[0059] The organic solvent (b2) may be used alone or in combination of two or more kinds.

[0060] The average normal boiling point of all the solvents constituting the organic solvent (b2) is, for example, 120 to 300°C, preferably 150 to 250°C, more preferably 170 to 250°C, and particularly preferably 180 to 250°C.

[0061] 2-2. Acrylic Resin (b3) Acrylic resin (b3) is a resin and its derivatives obtained by polymerizing or copolymerizing a monomer component including a (meth)acrylic monomer having a (meth)acryloyl group. By including acrylic resin (b3) in the adhesive ink (B) constituting the ink set of the present disclosure, hot-melt properties are enhanced, improving high-speed transferability. Furthermore, by including acrylic resin (b3), yellowing of the adhesive ink (B) can be suppressed even when the ink is heated. Heating of the adhesive ink (B) occurs during the manufacturing process of transfer media and printed materials, as described below. While resins other than acrylic resin (b3) can cause the layer formed from the adhesive ink (B) to yellow due to heating, including acrylic resin (b3) can suppress yellowing, which is advantageous for enhancing the design of the resulting printed material.

[0062] The acrylic resin (b3) is preferably a resin in which the total amount of (meth)acrylic monomers relative to the total amount of monomers constituting the resin is 30 mass % or more, more preferably 50 mass % or more, and even more preferably 70 mass % or more.

[0063] The acrylic resin (b3) preferably has a glass transition temperature (Tg) of 30°C or lower, more preferably -50 to 30°C, even more preferably -35 to 20°C, and particularly preferably -10 to 10°C. Having a Tg of acrylic resin (b3) at or below the upper limit mentioned above enhances high-speed transferability, and when the transfer medium is a fabric, the texture of the resulting printed matter can be improved. Furthermore, transfer media are sometimes wound up and stored in rolls, and in this case, blocking by the adhesive ink (B) can become a problem. However, having a Tg of acrylic resin (b3) at or above the lower limit mentioned above can suppress such blocking. The Tg of acrylic resin (b3) can be determined by differential scanning calorimetry (DSC).

[0064] When the acrylic resin (b3) is composed of two or more resins or when the acrylic resin (b3) has a core-shell structure, multiple Tg values ​​may be observed. In such cases, it is preferable that at least one Tg value satisfies the above range, and it is more preferable that all Tg values ​​satisfy the above range.

[0065] The weight average molecular weight (Mw) of the acrylic resin (b3) is, for example, 10,000 to 800,000, preferably 50,000 to 500,000, more preferably 100,000 to 400,000, and even more preferably 140,000 to 300,000. By adjusting the Mw of the acrylic resin (b3) to the above lower limit or more, the tensile durability can be further improved, and by adjusting the Mw to the above upper limit or less, the high-speed transferability can be further improved.

[0066] The molecular weight distribution of the acrylic resin (b3) is preferably 3 to 20, more preferably 4 to 12, even more preferably 4 to 10, and particularly preferably 4 to 8. By adjusting the molecular weight distribution of the acrylic resin (b3) within the above range, a better balance between high-speed transferability and tensile durability can be achieved. The molecular weight distribution is expressed as the ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn).

[0067] The Mw and Mn of the acrylic resin (b3) can be calculated by a standard polystyrene conversion method using gel permeation chromatography (GPC).

[0068] The acrylic resin (b3) preferably contains a structural unit derived from a (meth)acrylic acid alkyl ester. Examples of the (meth)acrylic acid alkyl ester include chain (meth)acrylic acid alkyl esters such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, sec-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, 2-octyl (meth)acrylate, tridecyl (meth)acrylate, n-lauryl (meth)acrylate, dodecyl (meth)acrylate, and stearyl (meth)acrylate; and cyclic (meth)acrylic acid alkyl esters such as cyclohexyl (meth)acrylate and isobornyl (meth)acrylate. The structural unit derived from the alkyl (meth)acrylate may be contained in the acrylic resin (b3) either alone or in combination of two or more.

[0069] Among the (meth)acrylic acid alkyl esters, (meth)acrylic acid alkyl esters having a homopolymer glass transition temperature (Tg) of −20° C. or lower (hereinafter, sometimes referred to as low Tg (meth)acrylic acid alkyl esters) and / or methacrylic acid C 1-5 Alkyl esters are preferred. By appropriately adjusting the content of structural units derived from these monomers, it becomes easy to adjust the Tg of the acrylic resin.

[0070] In this specification, the "glass transition temperature of a homopolymer" may be, for example, a value (when multiple Tg values ​​are listed, the lowest value) described in "POLYMER HANDBOOK THIRD EDITION" (by J. BRANDRUP and E. H. IMMERGUT, 1989, published by John Wiley & Sons, Inc., pp. VI / 209 to VI / 277). For compounds not described in "POLYMER HANDBOOK THIRD EDITION," a value (calculated value) determined by a computer using commercially available glass transition temperature calculation software (for example, "MATERIALS STUDIO" manufactured by Accelrys Software Inc., version: 4.0.0.0, module: Synthia, conditions: calculation with a weight average molecular weight of 100,000) may be used.

[0071] The Tg of the low Tg (meth)acrylic acid alkyl ester is −20° C. or lower, preferably −100 to −20° C., and more preferably −80 to −30° C. Examples of the low Tg (meth)acrylic acid alkyl ester include ethyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, n-pentyl acrylate, n-hexyl acrylate, n-octyl acrylate, 2-octyl acrylate, 2-ethylhexyl acrylate, n-nonyl acrylate, and isononyl acrylate, and among these, at least one selected from n-butyl acrylate, 2-octyl acrylate, and 2-ethylhexyl acrylate is preferred.

[0072] The methacrylic acid C 1-5 The alkyl ester refers to a compound in which the number of carbon atoms in the alkyl group constituting the methacrylic acid alkyl ester is 1 to 5. Among them, methacrylic acid C alkyl esters such as methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, and tert-butyl methacrylate are particularly preferred. 1-4 Chain alkyl esters are preferred, and methyl methacrylate is more preferred.

[0073] The content of structural units derived from alkyl (meth)acrylate in 100% by mass of the acrylic resin (b3) is preferably 20 to 100% by mass, more preferably 40 to 100% by mass, and even more preferably 70 to 99% by mass.

[0074] The acrylic resin (b3) preferably has a structural unit derived from an acid group-containing monomer. By including a structural unit derived from an acid group-containing monomer in the acrylic resin (b3), the stability of the acrylic resin (b3) is improved, and the tensile durability of the resulting printed matter tends to be further improved. The structural unit derived from the acid group-containing monomer may be included in the acrylic resin (b3) alone or in combination of two or more types.

[0075] The acid group-containing monomer may have at least one acid group and at least one polymerizable unsaturated group in the molecule. Examples of the acid group include a sulfo group and a carboxy group, with a carboxy group being preferred. The acid group may form a salt, and examples of the salt include an alkali metal salt and an ammonium salt. Examples of the alkali metal constituting the alkali metal salt include lithium, sodium, and potassium. The ammonium constituting the ammonium salt is NH4 + The organic ammonium may be tetraalkylammonium (preferably tetra C) such as tetramethylammonium or tetrabutylammonium. 1-10 trialkylammonium (preferably triC alkylammonium), trimethylammonium, triethylammonium, tributylammonium, etc. 1-10 hydroxyalkylammonium (preferably mono-, di- or tri(hydroxy C alkyl ammonium) such as monoethanolammonium, diethanolammonium, triethanolammonium, 1-10 dialkylmonohydroxyalkylammonium (preferably diC alkyl)ammonium), dialkylmonohydroxyalkylammonium (preferably diC alkyl)ammonium, dimethylmonoethanolammonium, etc. 1-10 Alkyl mono (hydroxy C 1-10 alkyl)ammonium) and the like.

[0076] Specific examples of the acid group-containing monomer include unsaturated monocarboxylic acids or salts thereof, such as (meth)acrylic acid, cinnamic acid, and crotonic acid; unsaturated dicarboxylic acids or salts thereof, such as maleic acid, fumaric acid, itaconic acid, and citraconic acid; unsaturated dicarboxylic acid monoesters or salts thereof, such as maleic acid monomethyl ester, maleic acid monobutyl ester, itaconic acid monomethyl ester, and itaconic acid monobutyl ester; unsaturated dicarboxylic acid anhydrides, such as maleic anhydride; 2-acryloyloxyethyl succinic acid, 2-acryloyloxyethyl phthalic acid, and 2-acryloyloxyethyl hexahydrophthalic acid. Among these, the acid group-containing monomer is preferably an unsaturated monocarboxylic acid and / or a salt thereof, and more preferably (meth)acrylic acid and / or a salt thereof.

[0077] The content of structural units derived from acid group-containing monomers in 100% by mass of the acrylic resin (b3) is, for example, 0 to 5.0% by mass, preferably 0.1 to 5.0% by mass, more preferably 0.5 to 4.0% by mass, and even more preferably 1.0 to 3.0% by mass.

[0078] The acrylic resin (b3) may have a structural unit derived from a styrene-based monomer. The structural unit derived from a styrene-based monomer can improve the water resistance of printed matter. The acrylic resin (b3) may contain one type of structural unit derived from a styrene-based monomer alone, or two or more types of structural units derived from a styrene-based monomer.

[0079] Examples of the styrene-based monomer include styrene; C alkyl groups such as halogen atoms (e.g., fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms); and alkyl groups (e.g., methyl groups, ethyl groups, n-propyl groups, isopropyl groups, n-butyl groups, and tert-butyl groups). 1-4 alkyl group), vinyl group, alkoxysilyl group (e.g., tri-C such as trimethoxysilyl group, triethoxysilyl group, etc. 1-4and styrene having one or more substituents such as a halogen atom and an alkyl group. The substituent is preferably at least one selected from a halogen atom and an alkyl group. Specific examples of the styrene-based monomer include styrene, vinyl toluene such as α-methylstyrene and p-methylstyrene, tert-butylstyrene, chlorostyrene, chloromethylstyrene, divinylbenzene, p-styryltrimethoxysilane, and 2-styrylethyltrimethoxysilane. Among the styrene-based monomers, styrene is preferred from the viewpoint of further increasing water resistance.

[0080] The content of structural units derived from styrene-based monomers in 100% by mass of the acrylic resin (b3) is preferably from 0 to 80% by mass, and may be from 20 to 70% by mass or from 35 to 60% by mass.

[0081] In particular, the acrylic resin (b3) contains a structural unit derived from a low Tg (meth)acrylic acid alkyl ester and a methacrylic acid C 1-5 The acrylic resin (b3) preferably contains a structural unit derived from an alkyl ester and / or a styrene-based monomer, and more preferably further contains a structural unit derived from an acid group-containing monomer. 1-5 The total content of structural units derived from alkyl esters, styrene-based monomers, and acid group-containing monomers is preferably 60% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, still more preferably 93% by mass or more, and may even be 100% by mass. The content of structural units derived from low Tg (meth)acrylic acid alkyl esters in 100% by mass of acrylic resin (b3) may be adjusted appropriately depending on the target Tg, but is preferably 20 to 90% by mass, more preferably 30 to 75% by mass, and even more preferably 40 to 60% by mass. Methacrylic acid C 1-5The total content of the structural units derived from the alkyl ester and the styrene-based monomer is preferably 20 to 200 parts by mass, more preferably 50 to 150 parts by mass, and even more preferably 80 to 120 parts by mass, per 100 parts by mass of the structural units derived from the low Tg (meth)acrylic acid alkyl ester. 1-5 The content is preferably 0 to 5.0 parts by mass, more preferably 0.5 to 4.0 parts by mass, and even more preferably 1.0 to 3.0 parts by mass, per 100 parts by mass of the total of the structural units derived from the alkyl ester and the styrene-based monomer.

[0082] The acrylic resin (b3) may have a structural unit derived from a monomer other than a (meth)acrylic acid alkyl ester, an acid group-containing monomer, and a styrene-based monomer. The other monomer is not particularly limited, and examples thereof include (meth)acrylic acid alkyl esters and (meth)acrylic monomers other than (meth)acrylic acid, such as hydroxyalkyl (meth)acrylates (e.g., 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate), alkoxyalkyl group-containing (meth)acrylates (e.g., methoxyethyl (meth)acrylate, methoxybutyl (meth)acrylate), and piperidine group-containing (meth)acrylates (e.g., 4-(meth)acryloyloxy-2,2,6,6-tetramethylpiperidine, 4-(meth)acryloyloxy-1,2,2,6,6-pentamethylpiperidine); 2-vinyl-2-oxazo Examples of the structural unit derived from other monomers include addition-polymerizable oxazolines such as 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-methyl-2-oxazoline, and 2-isopropenyl-5-ethyl-2-oxazoline; vinyl monomers such as vinyl acetate, vinyl chloride, and vinyl benzoate; acrylonitrile; (meth)acrylamide monomers such as (meth)acrylamide, N-monomethyl(meth)acrylamide, N-monoethyl(meth)acrylamide, and N,N-dimethyl(meth)acrylamide; and olefin monomers such as ethylene and propylene. The structural unit derived from other monomers may be contained in the acrylic resin (b3) singly or in combination of two or more types.

[0083] The content of structural units derived from other monomers in 100% by mass of the acrylic resin (b3) is, for example, 50% by mass or less, preferably 40% by mass or less, more preferably 20% by mass or less, even more preferably 5% by mass or less, and may be 0% by mass.

[0084] The acrylic resin (b3) may be a commercially available product or may be synthesized as appropriate. Synthesizing the acrylic resin (b3) can be accomplished by conventional polymerization methods, such as solution polymerization, bulk polymerization, suspension polymerization, and emulsion polymerization. Among these, emulsion polymerization is preferred, namely, a method in which monomer components ((meth)acrylic acid alkyl esters, acid group-containing monomers, styrene-based monomers, and other monomers) that constitute the structural units of the acrylic resin (b3) are emulsion-polymerized in an aqueous solvent (specifically, water or water and a water-soluble organic solvent) in the presence of an emulsifier and a polymerization initiator. By employing emulsion polymerization, an emulsion is obtained in which the acrylic resin (b3) is dispersed as emulsion particles in water (b1) or a mixed solvent of water (b1) and an organic solvent (b2), which is a water-soluble organic solvent, making it easy to prepare the adhesive ink (B). The specific means and conditions for polymerization can be appropriately selected and adopted from conventionally known means and techniques.

[0085] In order to adjust the weight-average molecular weight and molecular weight distribution of the resulting resin, the polymerization reaction may be carried out in the presence of a chain transfer agent. Examples of chain transfer agents include 2-ethylhexyl thioglycolate, tert-dodecyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, mercaptoacetic acid, mercaptopropionic acid, 2-mercaptoethanol, α-methylstyrene, and α-methylstyrene dimer. These chain transfer agents may be used alone or in combination of two or more. The amount of chain transfer agent used may be adjusted appropriately depending on the desired resin properties, but is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 3 parts by mass, and even more preferably 0.2 to 1 part by mass, per 100 parts by mass of the monomer components.

[0086] The acrylic resin (b3) may also be an acrylic urethane resin containing a structural unit derived from a polyisocyanate or a structural unit derived from a polyol as the structural unit derived from the other monomers described above. Examples of the acrylic urethane resin include copolymers of an acrylic resin and a urethane resin. More specifically, examples include copolymers obtained by polymerizing a urethane prepolymer with a (meth)acrylic monomer (e.g., a monomer having a (meth)acryloyl group, such as a (meth)acrylic acid alkyl ester, (meth)acrylic acid, or hydroxyalkyl (meth)acrylate), and incorporating a structural unit derived from a (meth)acrylic monomer or a side chain of a poly(meth)acrylic structure into the urethane skeleton. Examples of urethane prepolymers include those synthesized using the polyisocyanates and polyols described in "1-2. Urethane resin (a3)." The acrylic urethane resin included in the acrylic resin (b3) is preferably a resin in which the total amount of (meth)acrylic monomers exceeds 50% by mass of the total amount of monomers constituting the resin.

[0087] The acrylic resin (b3) may be used alone or in combination of two or more.

[0088] When the acrylic resin (b3) is contained in the adhesive ink (B), it is preferably added as an emulsion, that is, the acrylic resin (b3) is preferably contained in the adhesive ink (B) as emulsion particles.

[0089] The shape of the emulsion particles is not particularly limited, but they are usually spherical.

[0090] The emulsion particles may be resin particles having a single phase structure or resin particles having a multi-phase structure. The same explanations as for the resin particles having a single phase structure and the resin particles having a multi-phase structure in the urethane resin (b3) can be applied mutatis mutandis to the resin particles having a single phase structure and the resin particles having a multi-phase structure.

[0091] The emulsion particles may contain one or more types of resin particles having a single-phase structure, or may contain one or more types of resin particles having a multi-phase structure (preferably a core-shell structure), or may contain resin particles having a single-phase structure and resin particles having a multi-phase structure (preferably a core-shell structure).

[0092] The average particle size of the emulsion particles is, for example, 30 to 500 nm, preferably 80 to 300 nm, more preferably 100 to 300 nm, and even more preferably 150 to 250 nm. By adjusting the average particle size of the emulsion particles to fall within the above range, it becomes easier to incorporate the emulsion particles at a high concentration while maintaining the viscosity of the adhesive ink (B) within an appropriate range.

[0093] The content of the acrylic resin (b3) in the adhesive ink (B) is, for example, 5 to 40% by mass, preferably 10 to 30% by mass, and more preferably 12 to 25% by mass. By adjusting the content of the acrylic resin (b3) within the above range, the viscosity of the adhesive ink (B) can be maintained within an appropriate range while further enhancing the effects of the ink set of the present disclosure. Furthermore, the content of the acrylic resin (b3) is preferably 30 to 100% by mass, more preferably 60 to 98% by mass, and even more preferably 80 to 95% by mass, based on 100% by mass of the solids content of the adhesive ink (B).

[0094] The adhesive ink (B) may contain a resin other than the acrylic resin (b3), but preferably does not contain one. Examples of resins other than the acrylic resin (b3) include vinyl resins, polyester resins, olefin resins, urethane resins, fluororesins, silicone resins, epoxy resins, phenoxy resins, phenolic resins, and xylene resins. The content of the acrylic resin (b3) in 100% by mass of the resins contained in the adhesive ink (B) is preferably 60% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, and particularly preferably 100% by mass.

[0095] 2-3. Surfactant (b4) The adhesive ink (B) may further contain a surfactant (hereinafter, surfactant (b4)). By using the surfactant (b4), it becomes possible to adjust the static surface tension to a level suitable for inkjet ejection.

[0096] The surfactant (b4) may be any of the surfactants described above as surfactant (a5). Among these, acetylene glycol surfactants and / or silicone surfactants are preferred, silicone surfactants are more preferred, and polyether-modified silicone surfactants are even more preferred. The surfactants may be used alone or in combination of two or more.

[0097] The content of the surfactant (b4) is not particularly limited, but is preferably 0.1 to 4.0 mass %, more preferably 0.5 to 3.0 mass %, and even more preferably 1.0 to 2.0 mass %, relative to 100 mass % of the adhesive ink (B).

[0098] The use of two or more surfactants (b4) is preferable because it makes it easier to adjust the static surface tension of the adhesive ink (B) to a static surface tension suitable for inkjet ejection, even when the content of the resin that causes a decrease in ejection stability is high. When the surfactant (b4) is composed of two or more surfactants, the content of each surfactant is preferably 0.05 to 2.5% by mass, more preferably 0.1 to 2.0% by mass, even more preferably 0.2 to 1.5% by mass, and particularly preferably 0.4 to 1.0% by mass, relative to 100% by mass of the adhesive ink (B).

[0099] In particular, it is preferable to use a silicone surfactant and an acetylene glycol surfactant in combination as the surfactant (b4), and it is even more preferable to use a polyether-modified silicone surfactant and an acetylene glycol surfactant in combination, as the surfactant (b4). By using these in combination, the ejection stability of the adhesive ink (B) can be further improved.

[0100] When a silicone surfactant and an acetylene glycol surfactant are used in combination, the mass ratio thereof (silicone surfactant / acetylene glycol surfactant) is preferably 0.1 to 20, more preferably 0.2 to 10, even more preferably 0.5 to 4.5, particularly preferably 0.7 to 3.0, and most preferably 1.0 to 2.0. In particular, it is preferable to adjust the mass ratio of the polyether-modified silicone surfactant to the acetylene glycol surfactant (polyether-modified silicone surfactant / acetylene glycol surfactant) to be within the above range.

[0101] 2-4. Crosslinking agent (b5) The adhesive ink (B) may further contain a crosslinking agent (hereinafter referred to as crosslinking agent (b5)). The use of the crosslinking agent (b5) is thought to form a crosslinked structure through interaction with components contained in the adhesive ink (B), such as the acrylic resin (b3), or through a chemical reaction, thereby forming a tough coating film, which tends to improve the robustness of the resulting printed matter.

[0102] Examples of the crosslinking agent (b5) include an isocyanate compound, an epoxy compound, a melamine compound, a metal chelate compound, an aziridine compound, a mercapto compound, and an oxazoline compound, and the like, and the crosslinking agent (b5) may be used alone or in combination of two or more.

[0103] The oxazoline compound as the crosslinking agent (b5) means a compound having two or more oxazoline groups in the molecule. Examples of the oxazoline compound include 2,2'-bis(2-oxazoline), 2,2'-methylene-bis(2-oxazoline), 2,2'-ethylene-bis(2-oxazoline), 2,2'-trimethylene-bis(2-oxazoline), 2,2'-tetramethylene-bis(2-oxazoline), 2,2'-hexamethylene-bis(2-oxazoline), 2,2'-octamethylene-bis(2-oxazoline), 2,2 2,2'-p-ethylene-bis(4,4'-dimethyl-2-oxazoline), 2,2'-m-phenylene-bis(2-oxazoline), 2,2'-m-phenylene-bis(4,4'-dimethyl-2-oxazoline), bis(2-oxazolinylcyclohexane) sulfide, bis(2-oxazolinylnorbornane) sulfide, and oxazoline group-containing polymers.

[0104] Among the above oxazoline compounds, water-soluble oxazoline compounds are preferred from the viewpoint of excellent crosslinking performance, and oxazoline group-containing polymers are also preferred. The above oxazoline group-containing polymers can be produced by a conventionally known production method. For example, a method of polymerizing one or more addition-polymerizable oxazolines, or a monomer component including an addition-polymerizable oxazoline and a monomer copolymerizable with the addition-polymerizable oxazoline, can be mentioned.

[0105] Examples of the addition-polymerizable oxazoline include compounds having a polymerizable unsaturated group and an oxazoline group in the molecule, such as 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-methyl-2-oxazoline, and 2-isopropenyl-5-ethyl-2-oxazoline. Furthermore, the copolymerizable monomer is preferably a monomer that does not have a functional group that reacts with the oxazoline group and is copolymerizable with the addition-polymerizable oxazoline. For example, (meth)acrylic monomers such as (meth)acrylic acid alkyl esters; styrene-based monomers such as styrene, α-methylstyrene, and chloromethylstyrene; vinyl-based monomers such as vinyl acetate, vinyl chloride, and vinyl benzoate; acrylonitrile; (meth)acrylamide-based monomers such as acrylamide; and olefin-based monomers such as ethylene and propylene.

[0106] Among the oxazoline group-containing polymers, water-soluble oxazoline group-containing polymers are preferred, and can be produced by the same method as the above-mentioned method for producing the oxazoline group-containing polymer. Examples of the water-soluble oxazoline group-containing polymer include polymers having an acrylic resin or the like as a main chain and containing oxazoline groups in side chains.

[0107] Commercially available oxazoline group-containing polymers can also be used. Examples include water-soluble polymers such as EPOCROS WS-500 and EPOCROS WS-700, manufactured by Nippon Shokubai Co., Ltd., and emulsion polymers such as EPOCROS K-2010, EPOCROS K-2020, and EPOCROS K-2030. Of these, water-soluble polymers such as EPOCROS WS-500 and EPOCROS WS-700, manufactured by Nippon Shokubai Co., Ltd., are preferred.

[0108] The content of the crosslinking agent (b5) is not particularly limited, but may be, for example, 0 to 10 parts by mass, 0.1 to 8 parts by mass, or 0.2 to 5 parts by mass relative to 100 parts by mass of the acrylic resin (b3).

[0109] 2-5. Other Additives The adhesive ink (B) may contain other components in addition to the components described above, provided that the objectives of the present disclosure are not impaired. For example, additives such as dispersants, leveling agents, UV absorbers, UV stabilizers, thickeners, humectants, plasticizers, stabilizers, defoamers, antioxidants, colorants such as dyes and pigments, crosslinking accelerators, preservatives, pH adjusters, chain transfer agents, and chelating agents may be contained in appropriate amounts. When the above-mentioned other components are added, their content is not particularly limited, but is, for example, 10.0% by mass or less, preferably 5.0% by mass or less, and more preferably 3.0% by mass or less or 1.0% by mass or less, based on 100% by mass of the adhesive ink (B). Furthermore, to exert the effect of the addition, the content is preferably 0.01% by mass or more, and more preferably 0.05% by mass or more. That is, the content of the other components may be 0.01 to 10.0% by mass, 0.01 to 5.0% by mass, 0.05 to 3.0% by mass, or 0.05 to 1.0% by mass relative to 100% by mass of the adhesive ink (B).

[0110] 2-6. Physical Properties of Adhesive Ink (B) The pH of the adhesive ink (B) at 25°C is preferably 7 to 10, more preferably 7 to 9. By adjusting the pH of the adhesive ink (B) to fall within the above range, the dispersion stability of the ink can be improved.

[0111] The adhesive ink (B) preferably has a static surface tension at 25°C of 20 to 35 mN / m, more preferably 22 to 30 mN / m, and even more preferably 24 to 26 mN / m. By adjusting the static surface tension of the adhesive ink (B) to be equal to or greater than the above-mentioned lower limit, the amount of leveling agent can be reduced, and by adjusting it to be equal to or less than the above-mentioned upper limit, uneven drying of the ink can be reduced. The static surface tension can be measured by the method described in the examples below.

[0112] The adhesive ink (B) preferably has a viscosity of 2 to 10 mPa·s at 25°C, and more preferably 3 to 7 mPa·s. By adjusting the viscosity of the adhesive ink (B) to the above-mentioned lower limit or more, it is possible to reduce ink drying unevenness, and by adjusting the viscosity to the above-mentioned upper limit or less, it is possible to impart inkjet ejection stability. The viscosity can be measured using an E-type viscometer at a measurement temperature of 25°C.

[0113] 3. Ink Set 3-1. White Ink (A) and Adhesive Ink (B) The ink set of the present disclosure comprises a white ink (A) and an adhesive ink (B). The above-mentioned descriptions, including preferred embodiments thereof, can be applied mutatis mutandis to the white ink (A) and adhesive ink (B) that constitute the ink set of the present disclosure.

[0114] As described below, the white printing layer formed from the white ink (A) may be combined with a color printing layer for forming the desired image in the final printed product. When these are combined, the white printing layer is often formed thicker than the color printing layer in order to provide a base concealing function to make the color printing layer clearer. Therefore, even when a color printing layer is present, the quality of the printed product is strongly affected by the two layers of the white printing layer and the adhesive layer. Therefore, whether or not a color printing layer is formed, high-speed transferability and tensile durability can be improved by controlling the properties of the ink that constitutes the two layers of the white printing layer and the adhesive layer.

[0115] Furthermore, transferability can be improved by making the static surface tension of the adhesive ink (B) smaller than that of the white ink (A). As described below, the adhesive ink (B) is an ink printed on a layer formed from the white ink (A). If the surface tension of the adhesive ink (B) is the same as or greater than that of the white ink (A), the adhesive ink (B) will not spread well, resulting in greater unevenness in the film thickness of the layer formed from the adhesive ink (B), resulting in poor transferability. This unevenness in film thickness tends to have a greater effect on transferability, particularly when the image to be transferred is large or when the transfer speed is fast (short contact time between the transfer medium and the transfer-receiving medium). The static surface tensions of the white ink (A) and adhesive ink (B) are measured at 25°C.

[0116] The difference in static surface tension between the white ink (A) and the adhesive ink (B) (static surface tension of the white ink (A) - static surface tension of the adhesive ink (B)) is preferably 0.1 to 3.0 mN / m, more preferably 0.3 to 2.0 mN / m, and even more preferably 0.5 to 1.5 mN / m. The static surface tensions of the white ink (A) and adhesive ink (B) are measured at 25°C.

[0117] Furthermore, the difference (average standard boiling point B - average standard boiling point A) between the average standard boiling point of all solvents constituting the organic solvent (b2) contained in the adhesive ink (B) and the average standard boiling point of all solvents constituting the organic solvent (a2) contained in the white ink (A) is preferably -50°C or higher, more preferably 0°C or higher, even more preferably 0 to 100°C, and still more preferably 0 to 70°C. By adjusting this difference within the above range, it is possible to prevent the layer formed from the adhesive ink (B) from drying faster than the layer formed from the white ink (A), and to suppress the generation of bubbles in the layer formed from the white ink (A). As a result, it is possible to suppress the occurrence of bubbles causing defects in the resulting printed matter and reducing the tensile durability. In particular, when the content of the organic solvent (2-1) in the white ink (A) is 12% by mass or more and the average normal boiling point B - the average normal boiling point A is 0°C or more, i.e., the average normal boiling point A is the average normal boiling point B or less, the tensile durability of the resulting printed matter becomes even more excellent.

[0118] 3-2. Color Ink (C) In addition to the above-described white ink (A) and adhesive ink (B), the ink set of the present disclosure may further include one or more color inks (C) containing a colorant (c1) exhibiting a hue other than white.

[0119] The hue of the color ink (C) is not particularly limited as long as it is white, and may be selected from black, gray, and chromatic colors. Chromatic colors include the three primary colors of subtractive color mixing, magenta, yellow, and cyan, as well as colors of different shades, such as light cyan, dark yellow, light magenta, and light black. Furthermore, the color ink (C) may be one or more hues selected from red, blue, orange, green, and violet. The color ink (C) is preferably composed of at least one ink selected from the group consisting of cyan ink, magenta ink, yellow ink, and black ink, and more preferably composed of cyan ink, magenta ink, yellow ink, and black ink.

[0120] 3-2-1. Colorant (c1) The hue of the color ink (C) can be controlled by the colorant (c1). The colorant (c1) contained in the color ink (C) is not particularly limited, but colorants used in ordinary inkjet color inks can be used. The colorant (c1) may be a dye or a pigment, but is preferably a pigment from the viewpoint of further improving the fastness of the resulting printed matter. Examples of the pigment include organic pigments and inorganic pigments, which may be used alone or in combination of two or more types. Furthermore, if necessary, these may also be used in combination with an extender pigment.

[0121] Examples of organic pigments include azo pigments such as benzidine and Hansa Yellow, diazo pigments, azomethine pigments, methine pigments, anthraquinone pigments, phthalocyanine pigments such as phthalocyanine blue, perinone pigments, perylene pigments, diketopyrrolopyrrole pigments, thioindigo pigments, iminoisoindoline pigments, isoindolinone pigments such as iminoisoindolinone, dioxazine pigments, quinacridone pigments such as quinacridone red and quinacridone violet, flavanthrone pigments, indanthrone pigments, anthrapyrimidine pigments, carbazole pigments, monoarylide yellow, diarylide yellow, benzimidazolone yellow, tolyl orange, naphthol orange, and quinophthalone pigments.

[0122] The hue of the organic pigment is not particularly limited, and any pigment exhibiting the above-mentioned chromatic hue can be used. Specific examples of such organic pigments include C.I. Pigment Yellow, C.I. Pigment Red, C.I. Pigment Orange, C.I. Pigment Violet, C.I. Pigment Blue, and C.I. Pigment Green.

[0123] Examples of inorganic pigments include red iron oxide, black iron oxide, chromium oxide green, carbon black, yellow lead, molybdenum red, ferric ferrocyanide (Prussian blue), ultramarine, lead chromate, etc. Furthermore, examples of carbon black include furnace black, thermal lamp black, acetylene black, channel black, etc.

[0124] The average particle size of the pigment is preferably 20 to 500 nm, more preferably 30 to 200 nm, even more preferably 40 to 150 nm, and particularly preferably 50 to 100 nm, particularly from the viewpoint of color development.

[0125] The average particle size of the pigment can be measured by a laser diffraction / scattering particle size distribution analyzer or dynamic light scattering. For example, the cumulant average particle size measured by dynamic light scattering, as shown in the examples below, can be used. However, in cases where measurement by dynamic light scattering is difficult, such as in the case of black pigments, the 50% particle size in the volume-based particle size distribution measured by a laser diffraction / scattering particle size distribution analyzer can be used as the average particle size.

[0126] It is preferable that the pigment is dispersed and stabilized in the color ink (C) with a dispersant. For this reason, in the production of the color ink (C), it is preferable to mix the pigment, the dispersant, and a solvent (preferably water), and perform a dispersion treatment using a bead mill or the like to prepare a pigment dispersion in which the pigment is dispersed in the solvent, and then mix this with any optional components described below, such as a resin, to produce the color ink (C).

[0127] Examples of the dispersant include those exemplified as dispersants used in the white ink (A).

[0128] The content of the color material (c1) in the color ink (C) is preferably 1 to 50% by mass, more preferably 1 to 30% by mass, and even more preferably 2 to 15% by mass. The content of the color material (c1) is preferably 5 to 50% by mass, more preferably 10 to 40% by mass, and even more preferably 15 to 30% by mass, based on 100% by mass of the solid content of the color ink (C).

[0129] 3-2-2. Resin (c2) The color ink (C) preferably contains a resin (hereinafter referred to as resin (c2)). The weight-average molecular weight (Mw) of the resin (c2) is not particularly limited, but from the viewpoint of suppressing flow of the color ink (C) after printing, it is preferably 50,000 or more, more preferably 200,000 or more, and even more preferably 400,000 or more. The upper limit of the weight-average molecular weight of the resin (c2) is preferably 5,000,000 or less, from the viewpoint of improving film-forming properties and water resistance.

[0130] The glass transition temperature (Tg (°C)) of the resin (c2) is not particularly limited, but from the viewpoint of further improving the texture of the resulting printed matter, it is preferably −50 to 10°C, more preferably −45 to 5°C, and even more preferably −40 to 3°C.

[0131] The type of resin (c2) is not particularly limited, and examples thereof include vinyl resins, acrylic resins, polyester resins, olefin resins, urethane resins, fluororesins, silicone resins, epoxy resins, phenoxy resins, phenolic resins, and xylene resins. Among these, at least one selected from the group consisting of acrylic resins, polyester resins, and urethane resins is preferred, and acrylic resins and / or urethane resins are more preferred.

[0132] The composition of the acrylic resin or urethane resin used as resin (c2), including preferred embodiments thereof, can be directly applied to the composition of the acrylic resin (b3) or urethane resin (a3).

[0133] The resin (c2) may be used alone or in combination of two or more kinds.

[0134] When the resin (c2) is contained in the color ink (C), it is preferably added as an emulsion, that is, the resin (c2) is preferably contained in the color ink (C) as emulsion particles.

[0135] The shape of the emulsion particles is not particularly limited, but they are usually spherical.

[0136] The emulsion particles may be resin particles having a single-phase structure, or may be resin particles having a multi-phase structure (preferably a core-shell structure).

[0137] The average particle size of the emulsion particles is, for example, 10 to 500 nm, preferably 30 to 300 nm, more preferably 40 to 300 nm, and even more preferably 50 to 250 nm. By adjusting the average particle size of the emulsion particles to fall within the above range, it becomes easier to incorporate the emulsion particles at a high concentration while maintaining the viscosity of the color ink (C) within an appropriate range.

[0138] The content of resin (c2) in color ink (C) is, for example, 3 to 40% by mass, preferably 5 to 30% by mass, and more preferably 8 to 25% by mass. The content of resin (c2) is preferably 30 to 95% by mass, more preferably 50 to 90% by mass, and even more preferably 60 to 85% by mass, based on 100% by mass of the solid content of color ink (C).

[0139] 3-2-3. Solvent (c3) The color ink (C) preferably further contains a solvent. From the viewpoint of reducing the environmental impact, it is preferable to use an aqueous solvent as the solvent (c3). Examples of aqueous solvents include water and mixed solvents of water and an organic solvent (preferably a water-soluble organic solvent). From the viewpoint of improving moisture retention and compatibility with the resin, the solvent (c3) preferably contains water and an organic solvent (preferably a water-soluble organic solvent). The preferred aspects of the type and content of the organic solvent contained as the solvent (c3) are the same as the preferred aspects of the type and content of the organic solvent (b2).

[0140] The content of the solvent (c3) in the color ink (C) may be set according to the desired viscosity of the ink, and is not particularly limited, but is, for example, 40 to 95% by mass, preferably 50 to 90% by mass, and more preferably 60 to 88% by mass.

[0141] 3-2-4. Crosslinking agent (c4) The color ink (C) may further contain a crosslinking agent (hereinafter referred to as crosslinking agent (c4)). As the crosslinking agent (c4), the same crosslinking agent as described for the crosslinking agent (b5) can be used, and the same applies to the crosslinking agent (c4), including preferred embodiments thereof.

[0142] The content of the crosslinking agent (c4) is not particularly limited, but may be, for example, 0 to 10 parts by mass, 0.1 to 8 parts by mass, or 0.2 to 5 parts by mass relative to 100 parts by mass of the resin (c2).

[0143] 3-2-5. Surfactant (c5) The color ink (C) may further contain a surfactant (hereinafter, surfactant (c5)). As the surfactant (c5), the same surfactants as those described as surfactant (a5) can be used, and the same applies to them, including their preferred embodiments.

[0144] The content of the surfactant (c5) is not particularly limited, but from the viewpoint of ejection stability, it is preferably from 0.01 to 2.0% by mass, more preferably from 0.05 to 1.5% by mass, and even more preferably from 0.1 to 1.0% by mass, relative to 100% by mass of the color ink (C).

[0145] 3-2-6. Other Additives The color ink (C) may contain other components in addition to the components described above, provided that the objectives of the present disclosure are not impaired. For example, additives such as leveling agents, UV absorbers, UV stabilizers, thickeners, humectants, plasticizers, stabilizers, defoamers, antioxidants, crosslinking accelerators, preservatives, pH adjusters, chain transfer agents, and chelating agents may be contained in appropriate amounts. When the above-mentioned other components are added, their content is not particularly limited, but is, for example, 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, or 1% by mass or less, based on 100% by mass of the color ink (C). Furthermore, to achieve the desired effect, the content is preferably 0.01% by mass or more, more preferably 0.05% by mass or more. That is, the content of the other components may be 0.01 to 10% by mass, 0.01 to 5% by mass, 0.05 to 3% by mass, or 0.05 to 1% by mass.

[0146] 3-2-7. Physical Properties of Color Ink (C) The pH of the color ink (C) at 25°C is preferably 7 to 10, and more preferably 7 to 9. By adjusting the pH of the adhesive ink (B) to fall within the above range, the dispersion stability of the ink can be improved.

[0147] The viscosity of the color ink (C) at 25° C. is preferably 2 to 10 mPa·s, and more preferably 3 to 7 mPa·s. The viscosity can be measured at a measurement temperature of 25° C. using an E-type viscometer.

[0148] 3-3. Uses The ink set of the present disclosure can be suitably used as an inkjet ink set. Use of the ink set described above in inkjet printing is also encompassed within the scope of the present disclosure. In particular, the ink set of the present disclosure can be suitably used as an inkjet ink set used in transfer printing (preferably transfer printing on fabric), more specifically, as an inkjet ink set used in the manufacture of a transfer medium (preferably a transfer medium for transfer printing on fabric). The scope of the present disclosure also encompasses a method of using the ink set described above as an ink set for manufacturing a transfer medium (preferably a transfer medium for transfer printing on fabric) by an inkjet method. Note that, in this specification, "transfer medium" refers to a medium from which a transfer is made to a transfer-receiving medium. The ink set used in the method is as described above, and preferred embodiments thereof are also the same. Preferred embodiments of the transfer medium are described below in the section "4. Transfer Medium." Preferred embodiments of the transfer printing are described below in the section "5. Printed Material."

[0149] 4. Transfer Medium The present disclosure also encompasses transfer media manufactured using the ink set, specifically, transfer media in which a white printing layer formed from the white ink (A) is laminated on a transfer substrate or on a surface layer formed on the transfer substrate so as to be peelable from the transfer substrate, and an adhesive layer formed from the adhesive ink (B) is further laminated on the white printing layer. The transfer medium of the present disclosure is formed using the ink set described above. Therefore, use of this transfer medium can achieve excellent high-speed transferability and improved tensile durability of the resulting printed matter. Furthermore, it is preferable that the transfer temperature be lowered. Therefore, this transfer medium is suitable for transfer printing (particularly transfer printing on fabrics).

[0150] 1(a) and 1(b) are schematic cross-sectional views showing an example of the layered structure of a transfer medium according to the present disclosure. The transfer medium 100 in 1(a) and 1(b) has a white printed layer 2 on a transfer substrate 1, and an adhesive layer 3 on the white printed layer 2. The adhesive layer 3 may be provided only in the area where the white printed layer 2 is formed, as shown in 1(a) of FIG. 1, or may be provided in the area where the white printed layer 2 is formed as well as around it, as shown in 1(b) of FIG. The embodiment shown in 1(b) is preferred because it further improves the tensile durability of the resulting printed matter.

[0151] The white printing layer may be laminated directly on the transfer substrate as shown in Fig. 1, or may be laminated on the transfer substrate via a surface layer (hereinafter, sometimes simply referred to as the surface layer) formed on the transfer substrate so as to be peelable from the transfer substrate. Examples of the surface layer include an ink-receiving layer and a color printing layer formed from the color ink (C). The surface layer may be a single layer or may be formed from multiple layers.

[0152] 4-1. Transfer Substrate The transfer substrate is preferably in the form of a sheet or film to facilitate use of the transfer medium. The thickness of the transfer substrate is preferably 10 to 150 μm, and more preferably 30 to 80 μm.

[0153] The material of the transfer substrate is not particularly limited, but is preferably a material that does not shrink easily during the drying process described below.Specific examples of the material of the transfer substrate include metal, wood, plastic, and paper.Examples of the metal include aluminum and copper, with aluminum being preferred from the standpoint of cost.Examples of the plastic include polyolefin resin, polyester resin, polyamide resin, and polycarbonate resin, with polyester resin being preferred from the standpoint of cost, and aromatic polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate being more preferred.Examples of the paper include plain paper, high-quality paper, and coated paper.

[0154] In particular, the material of the transfer substrate is preferably plastic or paper from the viewpoint of cost, and more preferably polyester resin from the viewpoint of good heat resistance, further preferably aromatic polyester, and particularly preferably polyethylene terephthalate.

[0155] It is preferable that the transfer substrate has at least one surface subjected to a release treatment. By performing the release treatment on the surface of the transfer substrate on which the white printed layer is formed, it becomes easier to peel the white printed layer and adhesive layer, which are the transfer target, from the transfer medium to the transfer receiving medium, making it easier. Furthermore, by performing the release treatment on the surface of the transfer substrate opposite the surface on which the white printed layer is formed, it is possible to suppress blocking between the transfer media when the transfer media are stacked.

[0156] The method of release treatment is not particularly limited, and any known release treatment method can be used, but it is preferable to provide a layer obtained by coating a release agent on at least one surface of the transfer substrate. Examples of the release agent include polyethylene wax-based release agents, silicone-based release agents, and fluorine-based release agents.

[0157] The thickness of the release layer is not particularly limited, but is preferably 10 nm or more, more preferably 30 nm or more, from the viewpoint of further improving transferability, and is preferably 2 μm or less from the viewpoint of suppressing bulkiness when made into a roll-shaped transfer medium.

[0158] The transfer substrate may have a single layer structure or a multilayer structure.

[0159] 4-2. Ink-receiving layer The transfer medium of the present disclosure preferably has an ink-receiving layer as the surface layer. The ink-receiving layer can prevent ink ink-jet printed on the ink-receiving layer from flowing or crumbling, and can further increase the durability of the image after it has been transferred to the transfer medium. The ink-receiving layer is preferably laminated directly on the transfer substrate.

[0160] The ink-receiving layer is not particularly limited, and a known ink-receiving layer provided in an inkjet recording material can be used. The ink-receiving layer typically contains one or more resins, and examples of such resins include (meth)acrylic resins such as (meth)acrylic acid ester resins and (meth)acrylic acid ester-styrene copolymer resins; olefin resins such as polyethylene resins and polypropylene resins; silicone resins; polyvinyl alcohol resins; and wax resins. Preferred wax resins include microcrystalline wax, paraffin wax, synthetic wax, modified synthetic wax, and carnauba wax. Specific examples include EMUSTAR-042X, EMUSTAR-1155, EMUSTAR-0135, EMUSTAR-6315, EMUSTAR-1309, and EMUSTAR-0413 manufactured by Nippon Seiro Co., Ltd.

[0161] From the viewpoint of enhancing ink absorption, the ink-receiving layer preferably further contains one or more types of inorganic particles. Examples of inorganic particles include alumina, alumina hydrate, silica, calcium carbonate, magnesium carbonate, and titanium dioxide. The content of the inorganic particles in the ink-receiving layer is not particularly limited, but is preferably 25 to 400 parts by mass, and more preferably 33 to 300 parts by mass, per 100 parts by mass of the resin.

[0162] The ink receiving layer can be formed by a known method, for example, by coating a transfer substrate with a solution containing components constituting the ink receiving layer, such as the resin and inorganic particles.

[0163] The thickness of the ink-receiving layer is not particularly limited, but is preferably 30 nm to 20 μm, and more preferably 100 nm to 10 μm. By adjusting the thickness of the ink-receiving layer to be equal to or greater than the lower limit, the flow of ink can be suppressed, and by adjusting the thickness to be equal to or less than the upper limit, the manufacturing cost can be reduced.

[0164] The ink-receiving layer absorbs ink ejected onto the ink-receiving layer. Therefore, a portion of the white printed layer may be formed in the ink-receiving layer, the entire white printed layer may be formed (with the adhesive layer formed outside the ink-receiving layer), or the entire white printed layer and a portion of the adhesive layer may be formed. Furthermore, when the transfer medium has color printed layers (described below), a portion of the color printed layer may be formed in the ink-receiving layer, the entire color printed layer may be formed (with the white printed layer formed outside the ink-receiving layer), the entire color printed layer and a portion of the white printed layer may be formed, the entire color printed layer and the entire white printed layer (with the adhesive layer formed outside the ink-receiving layer), or the entire color printed layer, the entire white printed layer, and a portion of the adhesive layer may be formed.

[0165] 4-3. Color Printing Layer The transfer medium of the present disclosure may have a color printing layer formed from the color ink (C) as the surface layer. The color printing layer is a layer on which the desired image, such as characters or a pattern, is formed. Note that if the desired image can be formed using only a white printing layer, there is no need to have a color printing layer.

[0166] The color ink (C) forming the color print layer is the same as that explained in the section "3-2. Color ink (C)", including its preferred embodiments.

[0167] The color print layer may be any layer formed from the color ink (C), and may also include, for example, a layer formed by removing part or all of the volatile components (specifically, the solvent (c3)) contained in the color ink (C) through drying, etc. Furthermore, when the color ink (C) contains a crosslinking agent (c4), the color print layer may have a structure in which the resin (c2) is crosslinked by the crosslinking agent.

[0168] The color print layer may be a single layer or multiple layers.

[0169] 4-4. White Printed Layer The white printed layer is the base layer for the color printed layer on which the desired image, such as characters or a pattern, is formed in the resulting printed matter. The concealing properties of the white printed layer can enhance the color development of the image. The white ink (A) that forms the white printed layer is the same as that described in the section "1. White Ink (A)," including its preferred embodiments.

[0170] The white printed layer may be any layer formed from the white ink (A), and may also include, for example, a layer formed by removing some or all of the volatile components (specifically, solvents such as water (a1) and organic solvent (a2)) contained in the white ink (A) through drying, etc. Furthermore, when the white ink (A) contains a crosslinking agent, the white printed layer may have a structure in which a resin such as a urethane resin (a3) ​​is crosslinked by the crosslinking agent.

[0171] The white printed layer may be a single layer or multiple layers.

[0172] The film thickness of the white printing layer is preferably 1 to 100 μm, more preferably 3 to 50 μm, and even more preferably 5 to 35 μm. By adjusting the film thickness of the white printing layer to the above-mentioned lower limit or more, the hiding power of the white printing layer is improved, and the coating strength of the white printing layer is improved, thereby further enhancing the tensile durability of the resulting printed matter. Furthermore, by adjusting the film thickness to the above-mentioned upper limit or less, the white printing layer can be prevented from becoming too hard, thereby improving the texture of the resulting printed matter. The film thickness of the white printing layer can be adjusted by the ejection weight of the white ink (A). The ejection weight of the white ink (A) per unit area can be adjusted appropriately depending on the ink composition, but is preferably 5 to 200 g / m 2 is preferable, and more preferably 10 to 150 g / m 2 , more preferably 30 to 100 g / m 2 is.

[0173] 4-5. Adhesive Layer The adhesive layer is a layer that serves to adhere the image to the transfer medium during transfer printing. The adhesive ink (B) that forms the adhesive layer is the same as that explained in the section "2. Adhesive Ink (B)", including its preferred embodiments.

[0174] The adhesive layer may be any layer formed from the adhesive ink (B), and may also include, for example, a layer formed by removing part or all of the volatile components (specifically, solvents such as water (b1) and organic solvent (b2)) contained in the adhesive ink (B) through drying, etc. Furthermore, when the adhesive ink (B) contains a crosslinking agent (b5), the adhesive layer may have a structure in which a resin such as an acrylic resin (b3) is crosslinked by the crosslinking agent (b5).

[0175] The thickness of the adhesive layer is not particularly limited, but is preferably 0.5 to 200 μm, more preferably 1 to 150 μm, even more preferably 3 to 100 μm, and even more preferably 5 to 50 μm. By adjusting the thickness of the adhesive layer to the above-mentioned lower limit or more, transferability is further improved, and the coating strength of the adhesive layer is improved, thereby further increasing the tensile durability of the resulting printed matter. Furthermore, by adjusting the film thickness to the above-mentioned upper limit or less, the adhesive layer can be prevented from becoming too hard, thereby improving the texture of the resulting printed matter. The film thickness of the adhesive layer can be adjusted by the ejection weight of the adhesive ink (B). The ejection weight per unit area of ​​the adhesive ink (B) can be adjusted appropriately depending on the ink composition, but is preferably 5 to 300 g / m 2 is preferable, and more preferably 10 to 200 g / m 2 , more preferably 30 to 150 g / m 2 is.

[0176] 4-6. Method for Producing Transfer Medium The method for producing the transfer medium of the present disclosure is not particularly limited as long as the above-described ink set is used, but it is preferable to produce the transfer medium by a method including: a step of inkjet printing the white ink (A) onto a transfer substrate (hereinafter, sometimes referred to as step 2); and a step of inkjet printing the adhesive ink (B) onto the surface printed with the white ink (A) (hereinafter, sometimes referred to as step 3).

[0177] The phrase "inkjet printing white ink (A) onto a transfer substrate" includes not only an embodiment in which white ink (A) is inkjet printed directly onto a transfer substrate, but also an embodiment in which white ink (A) is inkjet printed onto a surface layer formed on the transfer substrate so as to be peelable from the transfer substrate. The surface layer preferably has a color printing layer on the surface on which the white ink (A) is printed, and the color printing layer can be formed by performing a step of inkjet printing the color ink (C) onto the transfer substrate (hereinafter sometimes referred to as step 1) prior to step 2. Each step will be described in detail below.

[0178] 4-6-1. Step 1 Step 1 is a step of inkjet printing the color ink (C) onto a transfer substrate. The explanation of "4-1. Transfer Substrate" can be applied mutatis mutandis to the transfer substrate used in Step 1, including preferred embodiments thereof. Note that "inkjet printing the color ink (C) onto a transfer substrate" includes not only an embodiment in which the color ink (C) is inkjet printed directly onto a transfer substrate, but also an embodiment in which the color ink (C) is inkjet printed onto another layer (e.g., an ink-receiving layer) formed on the transfer substrate so as to be peelable from the transfer substrate. The explanation of "4-2. Ink-receiving layer" can be applied mutatis mutandis to the ink-receiving layer, including preferred embodiments thereof. The explanation of "3-2. Color Ink (C)" can be applied mutatis mutandis to the color ink (C) used in Step 1, including preferred embodiments thereof.

[0179] An inkjet recording apparatus can be used as an apparatus for performing the inkjet printing in step 1. When an inkjet recording apparatus is used, the color ink (C) can be printed on the transfer substrate by ejecting the color ink (C) from an inkjet head and depositing the color ink (C) on a predetermined portion of the transfer substrate.

[0180] It should be noted that by using an inkjet recording apparatus equipped with a plurality of inkjet heads, it is possible to continuously carry out steps 1 and 2, steps 2 and 3, or steps 1 and 3. For example, steps 1 to 3 can be continuously carried out by installing the inks constituting the ink set (white ink (A), adhesive ink (B), and color ink (C) used as needed) in ink cartridges for each color of the inkjet recording apparatus, and ejecting the inks from the inkjet heads corresponding to each ink cartridge.

[0181] The number of times that the color ink (C) is printed is not particularly limited, and is, for example, 1 to 6 times, preferably 1 to 4 times. When printing is performed multiple times, the color ink (C) used in each printing may be the same or different. The amount of ink ejected per unit area in one printing is not particularly limited, and may be determined depending on the desired thickness of the color printing layer, but is preferably 1 to 100 g / m 2 is preferred, and 3 to 50 g / m 2 More preferably, 5 to 20 g / m 2 is more preferable.

[0182] In step 1, if necessary, a drying treatment (hereinafter referred to as drying treatment 1) may be carried out to evaporate some or all of the components of the printed color ink (C) excluding the solid content (i.e., the solvent). Even if an ink-receiving layer is provided on the surface on which the color ink (C) is to be printed, when the white ink (A) is further printed thereon, the color ink (C) may flow, making it impossible to obtain a clear image, and therefore it is preferable to carry out drying treatment 1.

[0183] In drying process 1, of the 100% by mass of the components of the color ink (C) excluding the solids, preferably 10 to 80% by mass, more preferably 15 to 70% by mass, even more preferably 20 to 60% by mass, and particularly preferably 20 to 50% by mass or 20 to 40% by mass is evaporated. Adjusting the evaporation amount to above the lower limit can suppress flow of the white ink (A) in step 2 described below. Adjusting the evaporation amount to below the upper limit can suppress peeling at the interface between the color printing layer and the white printing layer during transfer printing, thereby further improving high-speed transferability. The evaporation amount can be calculated by ejecting a certain mass of ink onto a substrate using an ink with a known solids concentration, and then measuring and calculating the total mass of the ink and substrate and the mass of the substrate alone after drying using a precision balance. Drying conditions that result in the desired evaporation amount are then determined, and the drying process is carried out under those conditions.

[0184] The device for performing the drying process 1 is not particularly limited, but for example, a heating means (e.g., a platen heater, a hot air heater, an infrared heater) in an inkjet recording apparatus can be used. Among these, it is preferable to use a platen heater from the viewpoint of uniform drying. If the inkjet recording apparatus does not have a platen heater, a planar heating element such as a rubber heater can be installed on the platen of the inkjet recording apparatus as an alternative to the platen heater.

[0185] The evaporation amount can be adjusted by controlling the heating temperature, heating time, hot air temperature, air volume, etc. It is preferable to set the conditions of the heater by measuring the evaporation amount in advance before an experiment. For example, when using a platen heater or a planar heating element as an alternative thereto, the color ink (C) can be dried by heating the backside of the transfer substrate with the platen heater or planar heating element. The heating temperature of the platen heater or planar heating element is preferably 30 to 80°C, more preferably 40 to 70°C, and even more preferably 40 to 60°C. Adjusting the heating temperature to above the lower limit can shorten the heating time, while adjusting the heating temperature to below the upper limit can prevent nozzle clogging due to heat transfer to the inkjet head.

[0186] The drying process 1 may be carried out simultaneously with the printing of the color ink (C), after the printing of the color ink (C), or both simultaneously with and after the printing of the color ink (C). When the drying process 1 is carried out simultaneously with the printing of the color ink (C), it may be carried out continuously from the start to the end of printing or may be carried out intermittently, but it is preferably carried out continuously. For example, when printing the color ink (C) multiple times, it is preferable to carry out the drying process 1 during the printing of each color ink (C) and / or after the end of printing. In this case, the evaporation amount of the components excluding the solid content of each color ink (C) may be adjusted to fall within the above range, or the evaporation amount of the components excluding the solid content of all the color inks (C) may be adjusted to fall within the above range.

[0187] A color print layer can be laminated on the transfer substrate through step 1. The color print layer constitutes an image such as a desired pattern or letters, but if the desired image can be formed using only a white print layer, step 1 can be omitted.

[0188] 4-6-2. Step 2 Step 2 is a step of inkjet printing a white ink (A) directly onto a transfer substrate or onto a surface layer formed on the transfer substrate so as to be peelable from the transfer substrate. The explanation for "1. White ink (A)" can be applied mutatis mutandis to the white ink (A) used in Step 2, including preferred embodiments thereof.

[0189] An example of an apparatus for inkjet printing in step 2 is an inkjet recording apparatus similar to that used in step 1. The number of times the white ink (A) is printed is not particularly limited, and may be, for example, 1 to 6 times, and preferably 1 to 4 times. When printing is performed multiple times, the white ink used in each printing may be the same or different. Furthermore, the amount of ink ejected in one printing is not particularly limited, and may be determined depending on the desired thickness of the white printed layer.

[0190] When a color print layer is formed on the printed surface of the white ink (A), it is preferable to print the white ink (A) at a position including directly above the color print layer.

[0191] In step 2, a drying treatment (hereinafter referred to as drying treatment 2) may be performed as needed. Drying treatment 2 is a treatment for evaporating some or all of the components (i.e., solvent) excluding solids in the white ink (A) and the color inks (C) used as needed. In drying treatment 2, preferably 10 to 80% by mass, more preferably 15 to 70% by mass, even more preferably 20 to 60% by mass, and particularly preferably 20 to 50% by mass or 20 to 40% by mass of the 100% by mass of the components excluding solids in the white ink (A) are evaporated. Adjusting the amount of evaporation to equal to or greater than the lower limit can suppress flow of the adhesive ink (B) in step 3 described below. Adjusting the amount of evaporation to equal to or less than the upper limit can suppress peeling at the interface between the white printing layer and the adhesive layer during transfer printing, thereby further improving high-speed transferability. The apparatus and conditions for drying treatment 2, including preferred embodiments, can be similarly described for drying treatment 1.

[0192] 4-6-3. Step 3 Step 3 is a step of inkjet printing an adhesive ink (B) onto the printed surface of the white ink (A). The same explanation as in "2. Adhesive ink (B)" can be applied mutatis mutandis to the adhesive ink (B) used in Step 3, including its preferred embodiments.

[0193] An apparatus for inkjet printing in step 3 can be the same as the inkjet recording apparatus used in step 1. The number of times the adhesive ink (B) is printed is not particularly limited and may be determined depending on the desired thickness of the adhesive layer, and is, for example, 1 to 6 times, preferably 1 to 4 times. Furthermore, in step 3, the amount of ink ejected in one printing is not particularly limited and may be determined depending on the desired thickness of the adhesive layer.

[0194] The adhesive ink (B) is preferably printed at a position including directly above the white printed layer.

[0195] In step 3, a drying treatment (hereinafter referred to as drying treatment 3) may be performed as needed. Drying treatment 3 is a step of evaporating some or all of the components (i.e., solvents) excluding the solid content of the white ink (A), adhesive ink (B), and color ink (C) that is used as needed.

[0196] In drying process 3, preferably 80 to 100% by mass, more preferably 90 to 100% by mass, of the total 100% by mass of the adhesive ink (B) excluding solids, is evaporated. The apparatus and conditions for drying process 1, including preferred embodiments, can be applied mutatis mutandis. Furthermore, in drying process 3, drying can be performed using natural drying, heating, reduced pressure, or contact with dry air or hot air, as needed. Hereinafter, this drying process may be referred to as drying process 3a. In drying process 3a, the heating temperature, heating time, pressure, hot air temperature, and air volume can be appropriately set depending on the desired evaporation rate. For example, when drying is performed by heating or contact with hot air, the heating temperature and hot air temperature are preferably 40 to 180°C, more preferably 80 to 160°C, and even more preferably 100 to 160°C. The heating time and hot air contact time are preferably 0.5 to 30 minutes, more preferably 1 to 20 minutes. In the drying treatment 3, it is preferable that drying by a heating means in the inkjet recording apparatus (preferably drying by a platen heater or a planar heating element) is performed continuously while the adhesive ink (B) is being printed, and that the above-mentioned drying treatment 3a (preferably drying by heating or contact with hot air) is performed after the printing of the adhesive ink (B). Furthermore, when printing of the adhesive ink (B) is performed multiple times, it is preferable that the adhesive ink (B) is dried by a heating means or an alternative means in the inkjet recording apparatus during and / or after the printing of each adhesive ink (B), and then dried by heating or contact with hot air after all printing is completed. In this case, the evaporation amount of the components excluding the solids in each adhesive ink (B) may be adjusted to within the above range, or the evaporation amount of the components excluding the solids in all adhesive inks (B) may be adjusted to within the above range.

[0197] By carrying out the above steps 1, 2, and 3, or the above steps 2 and 3 in this order, a transfer medium can be produced in which a white printing layer formed from the white ink (A) is laminated on a transfer substrate or on a surface layer formed on the transfer substrate so as to be peelable from the transfer substrate, and an adhesive layer formed from the adhesive ink (B) is further laminated on the white printing layer.

[0198] 5. The present disclosure also encompasses a printed matter in which an adhesive layer formed from the adhesive ink (B) constituting the ink set and a white printed layer formed from the white ink (A) constituting the ink set are laminated in this order on a print-receiving medium. The printed matter of the present disclosure has excellent tensile durability due to the use of a specific ink set.

[0199] The adhesive layer included in the printed matter can be described mutatis mutandis in "4-5. Adhesive layer", including preferred embodiments thereof. The white printed layer included in the printed matter can be described mutatis mutandis in "4-4. White printed layer", including preferred embodiments thereof.

[0200] The printed matter of the present disclosure may further include a color printed layer formed from a color ink (C) laminated on the white printed layer. The description of "4-3. Color printed layer" can be applied mutatis mutandis to the color printed layer included in the printed matter, including preferred embodiments thereof.

[0201] The transfer medium is not particularly limited, and can be metal, wood, plastic, paper, fabric, etc. The metal, wood, plastic, and paper that can be used as the transfer medium are the same as the examples of the metal, wood, plastic, and paper that can be used as the transfer substrate described above.

[0202] From the viewpoint of maximizing the effects of using the ink set of the present disclosure, it is preferable to use fabric as the transfer medium. The fabric is not particularly limited and includes all textile products such as cloth and textiles made from natural fibers and / or synthetic fibers. Examples of fabric include woven fabric, nonwoven fabric, and knitted fabric. The fibers constituting the fabric are also not particularly limited and include, for example, natural fibers, chemical fibers, or mixtures thereof.

[0203] Preferred examples of natural fibers include silk, cotton, and wool. Preferred examples of chemical fibers include synthetic fibers, regenerated fibers, and semi-synthetic fibers. Preferred examples of synthetic fibers include polyester fibers, nylon fibers, acrylic fibers, polyurethane fibers, polyethylene fibers, polypropylene fibers, and vinylon fibers. Preferred examples of regenerated fibers include rayon. Preferred examples of semi-synthetic fibers include acetate and triacetate. Among these, fabrics made from cotton, polyester fibers, polypropylene fibers, nylon fibers, or mixtures thereof are preferred, and fabrics made from cotton, polyester fibers, nylon fibers, or mixtures thereof are more preferred.

[0204] 5-1. Method for Producing Printed Material The printed material of the present disclosure is obtained by contacting the printing surface of the transfer medium described above with a medium to receive the transfer, thereby carrying out transfer printing. The transfer medium used in producing the printed material of the present disclosure is the same as that described above in "4. Transfer Medium," and its preferred aspects are also the same. The medium to receive the transfer used in producing the printed material of the present disclosure is the same as the medium to receive the transfer described above, and its preferred aspects are also the same.

[0205] The transfer printing method is not particularly limited, and conventionally known methods can be used. For example, transfer printing preferably includes a step of contacting the surface of a transfer medium on which an adhesive layer is formed with a transfer-receiving medium while facing the transfer-receiving medium (hereinafter referred to as a contact step), and a step of peeling the transfer substrate from the transfer-receiving medium. This allows the transfer substrate to be peeled off while leaving the printing layers (adhesive layer, white printing layer, and color printing layers that are laminated as needed) on the transfer-receiving medium.

[0206] 2 is a schematic cross-sectional view showing an example of the layered structure of the transfer medium and the transfer receiving medium in the contact step when the transfer medium shown in FIG. 1(b) is used. The surface of the transfer medium 100 on which the adhesive layer 3 is formed and the transfer receiving medium 4 are arranged to face each other and are in contact. In particular, when the transfer receiving medium 4 is a fabric, it is preferable that a portion of the adhesive layer 3 is embedded in the transfer receiving medium 4. This further improves the tensile durability of the resulting printed matter.

[0207] The contacting step preferably includes heating and pressurizing as necessary. For example, the contacting step may involve contacting the transfer medium with the transfer receiving medium using a press or a heated drum, and then applying heat and pressure.

[0208] The heating temperature in the contact step is not particularly limited, but is preferably 80 to 220°C, more preferably 120 to 200°C, and even more preferably 140 to 190°C. In the transfer printing of the present disclosure, a transfer medium manufactured using the ink set described above is used, so excellent transferability can be achieved even at a low transfer temperature (i.e., the heating temperature), specifically, 155°C or lower. Lowering the transfer temperature is preferable in that it allows application to a variety of transfer-receiving media. The pressure in the contact step is also not particularly limited, but is preferably 100 to 600 g / cm. 2 is preferable, and more preferably 200 to 500 g / cm 2 is.

[0209] The contact time is preferably 1 second or more from the viewpoint of further improving transferability. Furthermore, the upper limit of the contact time is not particularly limited, but from the viewpoint of productivity, it is preferably 1 minute or less, and more preferably 30 seconds or less. In the transfer printing of the present disclosure, a transfer medium manufactured using the ink set described above is used, so that excellent transferability can be achieved even if the transfer time, i.e., the contact time, is short. Specifically, excellent transferability can be achieved even if the contact time is 10 seconds or less.

[0210] After the contact step, the transfer substrate is peeled off to obtain the desired printed matter. Note that, from the viewpoint of further reducing the amount of image remaining on the transfer substrate, it is preferable to peel off the transfer substrate after the temperature of the transfer medium has reached 60°C or less (particularly 40°C or less).

[0211] The resulting printed matter may be further heated and pressurized using a press or a heated drum. By subjecting the resulting printed matter to additional heating and pressurization treatment, the image and the transfer medium are more tightly pressed together, and tensile durability is further improved. The heating temperature in this step is not particularly limited, but is preferably 80 to 200°C, and more preferably 100 to 180°C. The pressure in this step is also not particularly limited, but is preferably 100 to 600 g / cm. 2 is preferable, and more preferably 200 to 500 g / cm 2 The heating and pressurizing time in this step is not particularly limited, but is preferably from 1 second to 1 minute, and more preferably from 3 seconds to 30 seconds.

[0212] This application claims the benefit of priority based on Japanese Patent Application No. 2024-134527, filed on August 9, 2024. The entire contents of the specification of Japanese Patent Application No. 2024-134527, filed on August 9, 2024, are incorporated herein by reference.

[0213] The present disclosure will be described in more detail below with reference to examples, but the present disclosure is not limited to these examples. Unless otherwise specified, "parts" means "parts by mass" and "%" means "% by mass."

[0214] [Resin Production] (Resin Production Example 1) 252 parts of deionized water were charged into a polymerization vessel equipped with a stirrer, a reflux condenser, a thermometer, a nitrogen inlet tube, and a dropping funnel. A pre-emulsion for dropping was prepared by adding 437 parts of deionized water, 80 parts of a 25% aqueous solution of an emulsifier (manufactured by ADEKA, trade name: ADEKA REASORB SR-10), 25 parts of acrylic acid, 565 parts of 2-ethylhexyl acrylate, 50 parts of cyclohexyl methacrylate, 10 parts of hydroxyethyl methacrylate, and 350 parts of styrene to the dropping funnel. 44 parts, equivalent to 3% of the total amount of the pre-emulsion for dropping, was added to a flask. The temperature was raised to 80°C while slowly blowing in nitrogen gas, and 30 parts of a 5% aqueous ammonium persulfate solution was added to initiate polymerization. Thereafter, the remainder of the pre-emulsion for dropping and 30 parts of a 5% aqueous ammonium persulfate solution were uniformly added dropwise to the flask over 240 minutes. After the dropwise addition was completed, the contents of the flask were maintained at 80°C for 180 minutes, and the pH was adjusted to 8.5 and the solids content to 50% by adding 25% aqueous ammonia and deionized water, thereby terminating the polymerization. The resulting reaction solution was cooled to room temperature and then filtered through a 300-mesh wire net to obtain an emulsion containing acrylic resin as emulsion particles (hereinafter referred to as Emulsion 1). The solids content of Emulsion 1 was 50%. The emulsion particles contained in Emulsion 1 had an average particle size of 200 nm, a Tg of -21°C, and a weight-average molecular weight Mw of 1,100,000.

[0215] Resin Production Example 2 350 parts of deionized water was charged into a polymerization vessel equipped with a stirrer, a reflux condenser, a thermometer, a nitrogen inlet tube, dropping funnel A, and dropping funnel B. Thereafter, the internal temperature was raised to 75°C while stirring under a nitrogen gas stream. Meanwhile, a monomer emulsion A consisting of 265 parts of methyl methacrylate, 225 parts of 2-ethylhexyl acrylate, 10 parts of acrylic acid, 3.0 parts of t-dodecyl mercaptan as a polymerization chain transfer agent, 31.25 parts of Softanol 300 (manufactured by Nippon Shokubai) and 31.25 parts of Latemul WX (trade name, manufactured by Kao Corporation), each of which had been previously prepared as a 20% aqueous solution, and 91.5 parts of deionized water was charged into the dropping funnel A. Furthermore, the dropping funnel B was charged with a monomer emulsion B having the same composition as the monomer emulsion A, except that 2.0 parts of t-dodecyl mercaptan was used instead of the monomer emulsion A. Next, while maintaining the internal temperature of the polymerization vessel at 75°C, 27.0 parts of the monomer emulsion A, 5 parts of a 5% aqueous potassium persulfate solution (oxidizing agent) and 10 parts of a 2% aqueous sodium hydrogen sulfite solution (reducing agent), which served as polymerization initiators, were added to initiate prepolymerization. After 40 minutes, while maintaining the reaction system at 80°C, the remaining monomer emulsion A was added dropwise uniformly over 105 minutes. Simultaneously with the monomer emulsion A, 45 parts of a 5% aqueous potassium persulfate solution and 40 parts of a 2% aqueous sodium hydrogen sulfite solution were added dropwise uniformly over 105 minutes. Immediately after the dropwise addition of the monomer emulsion A was completed, the monomer emulsion B was added dropwise uniformly over 105 minutes. Simultaneously with the monomer emulsion B, 50 parts of a 5% aqueous potassium persulfate solution and 50 parts of a 2% aqueous sodium hydrogen sulfite solution were uniformly added dropwise over 105 minutes. After the completion of the dropwise addition of the monomer emulsion B, the temperature was maintained for 60 minutes, and the polymerization was terminated. The resulting reaction solution was cooled to room temperature, and then 16.7 parts of 2-(dimethylamino)ethanolamine as a pH adjuster (neutralizer) and 39 parts of deionized water were added. The mixture was then filtered through a 300-mesh wire mesh to obtain an emulsion containing an acrylic resin as emulsion particles (hereinafter referred to as emulsion 2). The solids content of emulsion 2 was 54%. The emulsion particles contained in emulsion 2 had an average particle size of 200 nm, a Tg of 0°C, a weight-average molecular weight Mw of 180,000, and a molecular weight distribution of 5.

[0216] [Measurement of Average Particle Size of Emulsion Particles] The average particle size of emulsion particles (cumulant average particle size) was determined by measuring the emulsion obtained in each Production Example as a measurement sample at 25°C using a particle size distribution analyzer (manufactured by Otsuka Electronics Co., Ltd., product number: FPAR-1000) using a dynamic light scattering method, and then determining the average particle size by cumulant analysis.

[0217] [Measurement of Resin Tg] The glass transition temperature (Tg) of the emulsion particles (resin) was measured by differential scanning calorimetry (DSC) under the following measurement conditions. Measurement equipment: DSC 3500 (trade name, manufactured by NETZSCH) Sample container: sealed aluminum container Sample weight: 10 mg ± 2 mg Measurement method: In a N atmosphere, a total of two cycles were performed, each cycle consisting of heating from -50°C to 150°C and cooling from 150°C to -50°C. The heating rate and cooling rate were both 10°C / min, and the holding times at -50°C and 150°C were 5 minutes. Using the analysis software Proteus Analysis, the glass transition temperature was analyzed from the DSC curve chart during the second heating cycle, and the value of the midpoint glass transition temperature was used.

[0218] [Measurement of Weight-Average Molecular Weight and Molecular Weight Distribution of Resin] The weight-average molecular weight (Mw) and number-average molecular weight (Mn) of emulsion particles (resin) were measured by GPC (gel permeation chromatography) under the following measurement conditions. Measuring instrument: HLC-8320GPC (manufactured by Tosoh Corporation) Molecular weight column: TSK-GEL SuperMultiporeHZ (manufactured by Tosoh Corporation) Eluent: Tetrahydrofuran (THF) Calibration curve standard: Polystyrene (manufactured by Tosoh Corporation) Measurement method: The measurement target was dissolved in THF to a solid content of approximately 0.2 mass%, and the resultant solution was filtered through a filter to measure the molecular weight. The flow rate of the liquid delivery pump was 0.35 ml / min. The ratio of the weight-average molecular weight to the number-average molecular weight (Mw / Mn) obtained above was taken as the molecular weight distribution.

[0219] [Preparation of Pigment Dispersion] (Pigment Dispersion Production Example 1) 3 parts of a dispersant, Joncryl 678 (manufactured by BASF), 1.3 parts of dimethylaminoethanol, and 81 parts of deionized water were mixed with stirring at 70°C. Next, 15 parts of a blue pigment, C.I. Pigment Blue 15:3 LIONOL BLUE FG-7330 (manufactured by Toyo Ink Co., Ltd.), 0.1 parts of a surfactant, Olfine D-10PG (manufactured by Nissin Chemical Industry Co., Ltd.), and zirconia beads with a particle size of 0.5 mm were added to a mixture filled to a volume ratio of 50%, dispersed using a bead mill, and filtered through a 1 μm pore size filter (MCP-1-C10S, manufactured by Advantec Co., Ltd.) to obtain a blue pigment dispersion containing 15% pigment (hereinafter referred to as Pigment Dispersion 1). The average particle size of the pigment was 90 nm.

[0220] (Pigment Dispersion Production Example 2) 5 parts of a dispersant, Discoat N-14 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), 6 parts of propylene glycol, 70 parts of deionized water, 100 parts of titanium oxide, CR-95 (manufactured by Ishihara Sangyo Kaisha), and zirconia beads with a particle size of 0.5 mm were filled at a volume ratio of 50%, dispersed using a bead mill, and filtered through a 1 μm pore filter (MCP-1-C10S, manufactured by Advantec Co., Ltd.) to obtain a white pigment dispersion containing 55% pigment (hereinafter referred to as Pigment Dispersion 2). The average particle size of the pigment was 330 nm.

[0221] [Measurement of Average Particle Diameter of Pigment] The average particle diameter (cumulant average particle diameter) of the pigment described above was determined by measuring the pigment dispersion obtained in each Production Example as a measurement sample at 25°C using a particle size distribution measuring instrument (manufactured by Otsuka Electronics Co., Ltd., product number: FPAR-1000) based on a dynamic light scattering method, and then determining the average particle diameter by cumulant analysis.

[0222] [Preparation of Color Inks] (Preparation of Cyan Ink 1) 20 parts of Emulsion 1 (10 parts as emulsion particles), 20 parts of Pigment Dispersion 1, 1.2 parts (0.3 parts as solids) of Epocross WS-700 (manufactured by Nippon Shokubai, solids content 25%), 2 parts of diethylene glycol monobutyl ether, 20 parts of diethylene glycol, 0.3 parts of a surfactant KF-6011 (manufactured by Shin-Etsu Chemical Co., Ltd.), and deionized water were mixed to a total of 100 parts, and the mixture was filtered through a 1 μm pore size filter (manufactured by Advantec Co., Ltd., MCP-1-C10S), to produce Cyan Ink 1.

[0223] (Preparation of Cyan Ink 2) Cyan ink 2 was produced in the same manner as in the preparation of cyan ink 1, except that emulsion 1 was changed to Permarin UA-200 (manufactured by Sanyo Chemical Industries, Ltd., polyether-based urethane emulsion, solid content 30%) and no crosslinking agent was used.

[0224] [Preparation of White Ink] (Preparation of White Ink 1) 20 parts of Emulsion 1 (10 parts as emulsion particles), 18.2 parts of Pigment Dispersion 2, 1.2 parts (0.3 parts as solids) of Epocross WS-700 (manufactured by Nippon Shokubai, solids content 25%), 2 parts of diethylene glycol monobutyl ether, 20 parts of diethylene glycol, 0.3 parts of a surfactant KF-6011 (manufactured by Shin-Etsu Chemical Co., Ltd.), and deionized water were mixed to a total of 100 parts, and the mixture was filtered through a 1 μm pore size filter (manufactured by Advantec Co., Ltd., MCP-1-C10S), to produce White Ink 1.

[0225] (Preparation of White Inks 2 to 7) White inks 2 to 7 were produced in the same manner as white ink 1, except that the type and amount of each raw material was changed as shown in Table 1 and the amount of deionized water was adjusted so that the total amount was 100 parts. The components used in Table 1 are as follows: Acrylic resin emulsion 1: Emulsion 1 obtained in Resin Production Example 1 Acrylic resin emulsion 2: Emulsion 2 obtained in Resin Production Example 2 Urethane resin emulsion 1: Polyether-based urethane emulsion (manufactured by Sanyo Chemical Industries, Ltd., Permarin UA-200, solids content 30%) Urethane resin emulsion 2: Polyester-based urethane emulsion (manufactured by Sanyo Chemical Industries, Ltd., U-coat UWS-145, solids content 35%) Urethane resin emulsion 3: Polycarbonate-based urethane emulsion (manufactured by Sanyo Chemical Industries, Ltd., Permarin UA-368, solids content 50%) Epocross WS-700: Oxazoline-based crosslinking agent (manufactured by Nippon Shokubai, solids content 25%) Surfynol 440: Acetylene glycol-based surfactant (manufactured by Evonik) KF-6011: Polyether-modified silicone-based surfactant (manufactured by Shin-Etsu Chemical Co., Ltd.)

[0226] (Preparation of Adhesive Ink 1) 27.8 parts of Emulsion 2 (15 parts as emulsion particles), 2 parts of diethylene glycol monobutyl ether, 20 parts of diethylene glycol, 0.6 parts of surfactant KF-6011 (a polyether-modified silicone surfactant, manufactured by Shin-Etsu Chemical Co., Ltd.), 0.5 parts of Surfynol 440 (an acetylene glycol surfactant, manufactured by Evonik), and deionized water were mixed to a total of 100 parts, and the mixture was filtered through a 1 μm pore size filter (MCP-1-C10S, manufactured by Advantec Co., Ltd.), to produce Adhesive Ink 1.

[0227] (Preparation of Adhesive Inks 2 to 4) Adhesive inks 2 to 4 were produced in the same manner as Adhesive Ink 1, except that the type and amount of each raw material was changed as shown in Table 1, and the amount of deionized water was adjusted so that the total amount was 100 parts.

[0228] [Measurement of static surface tension of ink] The static surface tension of the ink described above was measured at 25°C using the ink obtained in each preparation example as a measurement sample according to the Wilhelmy method using a surface tensiometer (manufactured by Kyowa Interface Science Co., Ltd., product number: DY-300).

[0229] [Examples 1 to 6, Comparative Examples 1 to 6] [Production of Transfer Sheet] (Preparation of Inkjet Ejection Device) Two printers (MMP-TX13) manufactured by Mastermind were prepared, designated Printer A and Printer B. In each printer, a rubber heater was installed on the platen and heated to 50°C. Printer A was filled with white ink and cyan ink. Printer B was filled with adhesive ink.

[0230] (Printing step) The transfer substrate was placed on a rubber heater, and an image was formed by the inkjet method. Specifically, solid printing (16 × 16 cm) was performed using printer A with cyan ink. 2 ) and then printed solidly with white ink (16 x 16 cm 2 The printed transfer substrate was transferred to printer B, and a solid print (16×16 cm) was further printed on it with adhesive ink. 2 The amount of cyan ink ejected per unit area was 10 g / m 2The ejection amount of white ink per unit area is 70 g / m 2 The adhesive ink ejection amount per unit area is 135 g / m 2 The transfer substrate used was a PET film having an ink-receiving layer on one side thereof, and the image was formed on the ink-receiving layer side.

[0231] (Drying Step) The substrate on which the image was formed was dried in a hot air dryer at 150° C. for 15 minutes to prepare a transfer sheet.

[0232] [Production of Transfer Printed Material] (Transfer Process) A transfer press machine TP-630M manufactured by Horizon International was used. The heating temperature was 150°C, and the press load was 3 kN (transfer pressure: 400 g / cm 2 ) was set. The fabric, which was the transfer medium, was placed on the lower iron, and then the transfer sheet was placed on top of that with the printed side facing down, and stamped for 10 seconds. After stamping, when the temperature of the fabric had dropped to 40°C or less, the transfer substrate was peeled off from the fabric, and a transfer print was obtained. The resulting transfer print was then placed again on the lower iron, silicone release paper was placed on top of the transfer print, and stamped for 5 seconds, thereby pressing the image onto the fabric. In the above transfer process, a 100% cotton white T-shirt manufactured by Hanes was used as the cotton fabric.

[0233] [Characteristics Evaluation] (1) Evaluation of High-Speed ​​Transferability After the transfer process, the transfer substrate obtained in each Example and Comparative Example was visually inspected to see whether or not the image printed by the inkjet printer remained on it. Those that remained were marked with "x", and those that did not remain were marked with "o". The results are shown in Table 2.

[0234] (2) Evaluation of Tensile Durability of Transfer Prints The transfer prints obtained in each Example and Comparative Example were held at both ends of the print (16 cm wide) with both hands, and pulled and stretched with both hands in the weft direction of the fabric until the print's width reached 24 cm, and the resulting product was used as a sample. The samples obtained by the above method were evaluated for tensile durability based on the number of cracks in the print visually confirmed, using the following three-point scale. The results are shown in Table 2. Note that in Comparative Examples 1, 3, 4, 5, and 6, it was not possible to transfer all of the images, and therefore it was not possible to evaluate the tensile durability of the transfer prints. ◯: 3 or fewer cracks △: 4 to 10 cracks ×: 11 or more cracks

[0235]

[0236]

[0237] 100 Transfer medium 1 Transfer substrate 2 White print layer 3 Adhesive layer 4 Transfer receiving medium

Claims

A white ink (A) and an adhesive ink (B), the white ink (A) contains water (a1), an organic solvent (a2), a urethane resin (a3), and a white pigment (a4); the adhesive ink (B) contains water (b1), an organic solvent (b2), and an acrylic resin (b3); An inkjet ink set, characterized in that the static surface tension of the adhesive ink (B) is lower than the static surface tension of the white ink (A). 　 the urethane resin (a3) ​​is contained in the white ink (A) as emulsion particles, The ink set according to claim 1 , wherein the acrylic resin (b3) is contained in the adhesive ink (B) as emulsion particles. 　 The ink set according to claim 1 , wherein the acrylic resin (b3) has a glass transition temperature of 30° C. or less.

2. The ink set according to claim 1, wherein the acrylic resin (b3) has a weight average molecular weight of 10,000 to 800,000. 　 The ink set according to claim 1 , which is used in the manufacture of a transfer medium. 　 The ink set according to claim 1 , which is used in the production of a transfer medium for transfer printing onto fabric. 　 The ink set according to claim 1 , further comprising one or more color inks (C) containing a colorant (c1) exhibiting a hue other than white.

8. The ink set according to claim 7, wherein the color ink (C) is at least one selected from the group consisting of a cyan ink, a magenta ink, a yellow ink, and a black ink. 　 the organic solvent (a2) comprises an organic solvent (2-1) having a normal boiling point of 250°C or less, 2. The ink set according to claim 1, wherein the content of the organic solvent (2-1) in the white ink (A) is 12% by mass or more.

2. The ink set according to claim 1, wherein the average normal boiling point of all solvents constituting said organic solvent (a2) is equal to or lower than the average normal boiling point of all solvents constituting said organic solvent (b2). 　 A method for producing a transfer medium using the ink set according to any one of claims 1 to 10, comprising: a step of ink-jet printing the white ink (A) onto a transfer substrate or onto a surface layer formed on the transfer substrate so as to be peelable from the transfer substrate; and inkjet printing the adhesive ink (B) onto the printed surface of the white ink (A). 　 A method for producing a printed matter, comprising contacting a printing surface of a transfer medium obtained by the method according to claim 11 with a medium to receive the transfer, thereby carrying out transfer printing.

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